Page No.:197

4.14.14.14.1 IntroductionIntroductionIntroductionIntroduction

Early experiences with UV curable resins caused UV

processing to be carefully scrutinized, which resulted in a

remarkably detailed understanding and favorable track record in

long term health and safety issues. Today’s UV technology makes

UV processing, if not the safest, one of the safest and most

efficient and profitable industrial process technologies available

[1].

In the technology’s infancy, UV processing was referred to

as ‘Radiation’ or ‘Rad-Cure’ Technology. This came back to

haunt the budding UV industry because the layman factory

worker interpreted ‘radiation’ to mean the type of radiation

associated with nuclear radiation. UV radiation is simply light

radiation and is by no means the type of radiation associated

with nuclear (radioactive) materials.

UV processing received heightened scrutiny over the last

few years, which has resulted in remarkably good record in

terms of health, safety and economic benefits. The research

efforts to design develop, and market new UV curable raw

materials, correspondingly, the formulator’s arsenal of raw

materials have grown dramatically which has in turn increased

the latitude to design products with specific properties.

Most expect that UV technologies will continue to grow

faster than the general economy as new applications are

commercialized. The mega-drivers of lean manufacturing and

environmental regulations are stronger than ever and likely to

increase in the future.

In a survey recently completed by Rad Tech, respondents

listed applications that are in the early stages of development

and have the greatest probability of widespread use by 2007. The

top results and their percentage probabilities for widespread

success by 2007 are

Page No.:198

1. Coatings for plastics - 73%

2. Impact less printing (Ink Jet) - 72%

3. Wide Web Flexo - 63%

Other results from the survey indicate that free radical

curing acrylates will continue to account for the bulk of the

radiation cured coatings, accounting for 85%. There will be

modest growth in percentage of formulations using cationic

systems. UV will continue to be the dominant technology.

4.24.24.24.2 Application of UApplication of UApplication of UApplication of UV cured coatingsV cured coatingsV cured coatingsV cured coatings

The primary applications for radiation curable polymers

include inks, adhesives, and coatings where coatings are by far

the largest segment. Some of the more important coating

applications are found in everyday products such as hardwood,

flooring, metal and wood furniture, electrical wire and cable,

release papers, beverage cans, magazine covers, packaging,

leather finishes, computer magnetic media and optical fiber

[2,3].

INDUSTRYINDUSTRYINDUSTRYINDUSTRY APPLICATIONAPPLICATIONAPPLICATIONAPPLICATION

AIM Coatings

(Architectural/Industrial

/ Maintenance Coatings

applied to protect from

corrosive environment)

Metal and Concrete Structures

Pipes and Tanks

Processing Equipment

Aircraft Primers

Color Coats and Topcoats

Automotive Parts Underbody paints

Primers

Color Coats and Topcoats

Refinishing

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Coil Coatings Applied to coiled sheet metal that is

used in:

� Household appliance Industries

� Transportation Industries

� Construction Industries

� Container Industries

Dental � Fillings

Electronics � Microelectronics photo masks &

Solder masks

� Notations on Circuit Board

� Encapsulation of circuits

� Optical fiber coatings

� Compact (CDs)

� Digital Video Disks (DVDs)

Flexible Plastics � Decorative Laminates

� Shrink Film

� Magnetic Recording Media

� Abrasive Films & Release Films

Highway � Coatings used to mark lanes

� Coatings used to provide

directional arrows on roadway

Leather � Finishes

� Topcoats

Machinery and

Equipment

� Farm Equipment

� Construction Equipment

� Electrical Machinery

� Heating, Ventilating and air

conditioning systems (HVAC)

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Marine � Ships

� Offshore Platforms

� Other Steel and Aluminum

Structures.

Metal Containers � Beverages and Food Cans

� Lids and Closures

Optics � Eyeglass Lenses

� Optical Fibers

Paper and Paperboard � Record Albums

� Folding Cartons

� Juice Cartons

� Magazines and Paper Books

� Business Forms

� Banknotes and Money

� Release and Abrasive Coated Paper

Rigid Plastics � Vinyl Floor Covering and Tiles

� Bottles

� Credit Cards

� Sports and Medical Equipment

Textiles � Sizing

� Fill coats and Topcoats

Wood Furniture � Furniture

� Kitchen Cabinets

� Doors

� Trim and Moldings

Wood Products � Plywood panels

� Particle board panels

� Hardwood flooring

� Door laminates.

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Even with the above mentioned advantages, radiation

cured coatings are having a difficult time emerging from their

early status as a niche product. This is mainly due to the high

material ’s cost and capital investment required for radiation

curing product lines. However, radiation cured coatings are often

justified on a "total" cost basis when considering electricity bills,

reduction in waste, labor cost, production time, and factory

space availability.

A large future market is expected to be automotive refinish

[4,5] shops which will require coatings that can be used on a

variety of parts and UV curing equipments which deliver

"diffused" light of longer wavelengths for 3-D curing of complex

geometries. For this market, "dual-cure" coatings [6] are being

developed. They cure rapidly under a UV lamp, and any parts

that are in shadow areas, such as under wheel arches, will cure

fully over a longer period through the action of a catalyst added

to the formulation at the time of coating.

Future market penetration will not only rely on acceptance

of UV radiation cured coatings and the displacement of

conventional systems, but will also be determined by the rate of

development and innovation and its value to the industry.

Significant developments have also occurred on the

equipment side of the radiation cured coatings industry. Over

the past several years, UV system manufacturers have extended

bulb life warranty from 5000 hrs to 8000 hrs and, most

importantly, the cost of the bulb has not increased. New "lean"

UV systems are also being designed which will allow

manufacturers to get involved with radiation cured coatings

without onerous investment. These new systems will also provide

potential small volume users with access to affordable and

flexible radiation cure technology [7].

Page No.:202

4.2.14.2.14.2.14.2.1 UV LightUV LightUV LightUV Light

Our earth is exposed to a large spectrum of

electromagnetic rays, the best known of these being: Ultra-Violet

(UV) rays, visible light and Infra-Red (IR) rays. These rays are

characterized by their Wavelength, and expressed in nanometer

(nm); the wavelength is inversely proportional to the energy they

are carrying.

IR rays are known to produce heat and UV rays may be

used to initiate the photochemical process, called “UV curing”’ in

UV curable inks and coatings.

The UV spectrum stretches from 200 nm to 400 nm; in

fact, the photochemical process involves rays that are emitted

between 180 nm and 380 nm.

E = hc / λ

E = constant / λ

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The UV spectrum is divided into three domains [8]:

UV-A (315-380 nm): These rays, the closest to the visible

light part of the spectrum are responsible for stimulating a

suntan response in humans, and cause the curing of the deeper

layers of the ink or coating film.

UV-B (280-315 nm): This domain helps to maintain an

extensive reaction. Thanks to their longer wavelength, these rays

enable a deeper penetration of the film.

UV-C (200-280 nm): These high-energy rays are essential

for the curing (or polymerization) of UV inks and coatings; they

ensure a complete and fast reaction. They favour surface curing

of the film.

4.2.24.2.24.2.24.2.2 Key parameter in UV curing processingKey parameter in UV curing processingKey parameter in UV curing processingKey parameter in UV curing processing

The physical properties of UV-cured materials are

substantially affected by the lamp system used to cure them.

The four key factors of UV exposure are UV intensity, spectral

distribution (wavelength) of UV light, UV energy and infrared

radiation component [9].

UV Intensity is the radiant power, within a stated

wavelength range, arriving at a surface per unit area, usually

expressed in watts or mill watts per square centimeter (W/cm2).

Intensity varies with lamp output power, efficiency and focus of

its reflector system, and distance to the surface. (It is a

characteristic of the lamp geometry and power, so does not very

with speed). Today, the lamps with 80 W/cm2 , 160 W/cm2 and

240 W/cm2 to 300 W/cm2 are available in the market [10].

Wavelength it is the wavelength distribution of radiant

energy emitted by a source or arriving at a surface. It may be

expressed in power units or in relative (normalized) terms.

UV Energy is the radiant energy, within a stated

wavelength range, arriving at a surface per unit area. Sometimes

loosely (but incorrectly) referred to as “Dose,” It is the total

accumulated photon quantity arriving at a surface, per unit

area. Energy is inversely proportional to speed under any given

Page No.:204

l ight source, and proportional to the number of exposures (for

example, rows of lamps). It is expressed in joules or millijoules

per square centimeter (J/cm).

Infrared Radiance is the amount of infrared energy

emitted by the quartz envelope of the UV source. The heating

effect it produces may be a benefit or a nuisance. This is

difficult to measure, so it is often easier to measure its effect on

the temperature of the work surface.

Up to certain point the curing rate will increase with the

amount of UV energy per unit surface. This increase is not

linear. In fact, the curing rate of the most monomers, in the

presence of air, raises much faster then the intensity of UV

energy. If the amount of UV energy per unit surface is doubled,

the curing speed may be tripled, quadrupled, or even accelerated

ten fold. The results of this relation between curing rate and UV

intensity is that two UV lamps of certain power will not affect as

fast a cure as the one lamp having twice the power. A more

powerful lamp would double the amount of energy falling on the

surface, while the curing speed would be more then double. UV

cure lamps, therefore, should have the highest power to size

ratio attainable without sacrificing lifetime or reliability. This

non-linear relation between cure rate and UV energy dictate the

design of the reflector to be used in conjunction with the UV

lamp. A reflector that concentrates UV energy on a small surface

will provide faster curing than a reflector giving a uniform

distribution of UV over larger surface.

The light spectrum emitted by the source (UV Lamp) is also

important and should be carefully selected for the proper curing

a UV initiator since it require the same range of UV wavelength

for proper initiation. At the same time initiator should absorb

UV rays in a range that is not absorbed by the monomer or the

pigment present in the formulation. The wavelength emitted by

the UV source should coincide with the wavelength absorbed by

the UV initiator. Since medium pressure mercury vapour lamps

emit a wide range of UV (180- 400 nm), they are suitable for all

UV cure applications [11].

Page No.:205

4.2.34.2.34.2.34.2.3 UV Curable Coating formulationUV Curable Coating formulationUV Curable Coating formulationUV Curable Coating formulation

A UV formulation is a blend or mixture of a number of

chemical components designed to meet the properties required

by the production method and the finished product. Detailed

description on UV curable coating component is discussed in

Chapter no. 1. The following chart explains the key component of

UV–Curable coating formulation.

In the present chapter urethane acrylate oligomers (from

Chapter 3) based formulations are studied for their applications

as high performance coatings properties.

Since present study is about the utilization of urethane

acrylate oligomers (Based on renewable resources) for UV-cured

Coatings the review on their Synthesis and Applications is in

order.

Page No.:206

4.34.34.34.3 LLLLiterature reviewiterature reviewiterature reviewiterature review

4.3.14.3.14.3.14.3.1 Synthesis of UVSynthesis of UVSynthesis of UVSynthesis of UV----cured coatingscured coatingscured coatingscured coatings

Pacifici et. al. [12] disclosed the use of cellulose derivatives

in radiation curable coatings. The authors prepared and

evaluated eight series of cellulose derivatives with a pendent

glycidyl acrylate and glycidyl methacrylate to produce cross

linking sites which was readily crosslinked upon exposure of UV

radiation.

S.C.Jain et. al. [13] reviewed radiation cured coatings and

discussed about the formulation of radiation cure coatings.

Detailed discussion on formulation of UV curable coating

composition and detail information including oligomer family,

reactive diluents, and photo-initiator was given in the review.

Li Jun et. al. [14] synthesized a novel polyester urethane

acrylate resin modified by linseed oil fatty acid (LFA) and EB

curing coating was formulated in his work. When the coating

cured by EB radiation on the timber, the cured coating

possessed of good performances such as gloss, hardness and

adhesion.

Cook and Kelley et. al. [15] developed radiation curable

silyl ether of cellulose ester .The silyl ether pendant groups

contain thiol functionality that can function as cross linking

agents. Thiol groups are radical initiation sites and aid in the

formation of fully cured network. The hardness of coatings and

the level of solvent resistance showed excellent results.

E. Dzunuzovic et. al. [16] synthesized hyper branch

Urethane acrylate from Soya fatty acid modified polyester and

reported that the reduction in viscosity was observed after

modification of hyper branch polyester polyol with Soya fatty

acid.

C.S.B Ruiz et. al. [17] reported that the quality and

performance of the polymeric materials cured by ultraviolet

(UV)/electron beam (EB) radiation depends on the components of

Page No.:207

coating formulation, as well as the type of radiation used in the

curing process. Author also established the correlation between

the cure degree of a clear coating irradiated with different

radiation doses of UV or EB and the tensile properties of the

polymeric films obtained.

Koehler M. et. al. [18] prepared a photoinitating polymer

which could be used as a base coat and then catalyzed the

curing of a UV-hardnable topcoat and obtained the coating with

a controlled thickness.

Formulations, uses and advantages of UV-curable coatings

for wood were discussed by Chiocchetti and Petro et. al. [19]

and weathering test results shows high durability of the coating.

Mannfolk et. al. [20] prepared a UV-light hardenable

coatings for paper in which natural rosin that has been first

modified and then acrylated. Ethoxylated tall rosin was

esterified with acrylic acid to give a product with acid no 50 and

mixed with epoxy acrylate and photoinitiators and was applied to

60 g/m2 paper and hardened 4-fold at 18 m/min and 80 W/cm2

in a UV apparatus to give a glossy hard lacquer layer.

A number of saturated long chain dibasic acid modified

epoxydiacrylates were synthesized by Hongbo Liu et al [21]. The

UV-curable formulations were prepared with those as oligomers

and the physical and mechanical characterizations of the UV

cured films were investigated and found that the addition of the

soft long chain in oligomers caused the remarkable increase in

elongation at break.

UV-curable systems based on the copolymerization of a

typical acrylic resin with a low amount of a fluorinated monomer

(<1%, w/w) were used by R. Bongiovanni et. al. [22] for the

protection of wood panels. In the presence of the additives, the

bulk properties and the adhesion of the acrylic films were

unchanged, while a strong modification of the surface was

obtained. The quality aspects and the chemical resistance of the

coatings applied to the wood panels were also enhanced.

Page No.:208

Water borne UV-curing binders based on acrylic polymer

dispersions ware developed by Dirk Mestach. et. al. [23] which

do not contain any low molecular weight monomers and therefore

are considered to be non-irritant. These acrylic dispersions are

formulated in such a way that they are similar to other

waterborne one component coatings. All of the conventional

additives such as dispersant, wetting agents, coalescing solvents

and matting agents were used and when applied to a substrate

the coatings dry to a give tack-free surface. Full curing takes

place when UV-radiation is applied to the coated surface and the

resulting cross linked polymeric coating have excellent

mechanical and chemical resistance properties.

Hieudu et. al. [24] synthesized UV-curable coating

composition for the protection of plastics. A 3 mm thick PMMA

sheet dipped in this coating composition was first dried in air for

~5 min and irradiated with UV (100 mJ/cm2) and the resulting

10 µm film of coating showed 7H pencil hardness, good

adhesion, abrasion and water resistance.

A new photo initiator, bis (2, 6-dimethoxybenzoyl)-2, 4, 4-

trimethylpentylphosphine oxide (l), was synthesized by W.

Rutsch et al [25] for industrial applications. The absorption of

this bisacylphosphine oxide (BAPO) compound in the near UV-

VIS range is significantly higher than that of hitherto known

photo initiators for UV curing. Studies using FTIR and RTIR

techniques showed that these features result in a higher

conversion of acrylic double bonds than obtained with other

photo initiators in formulations containing a high loading of

rutile type titanium dioxide pigments.

The synthesis of a new urethane acrylate monomer (UAM)

from hexamethylene diisocyanate trimer (HDT) and 2-

hydroxyethyl methacrylate was performed by classical

condensation. Physicochemical and thermal characterization of

UAM was investigated (Mn=1480 g mol -1 ; Tg = -38oC) and no

secondary reactions were observed by F. Burela et al [26].

Page No.:209

Functionalized copolymers for using as UV curable

coatings were synthesized by Carsten Wuertz et. al. [27] from

three different monomers; methylmethacrylate, n-butylacrylate

and glycidyl-methacrylate. The synthesis of functionalized

copolymers consisted of two steps, the polymerization and the

fictionalization, and performed to high conversion rates as

proved by gas chromatographically residual monomer detection.

The synthesized coatings varied both in the polymer backbone

composition as well as in the crosslink density. UV curing was

performed in the presence of a commercially available

photoinitiator system. Physicochemical surface properties of the

coatings were investigated by measuring the zeta potential–pH

dependence. The results indicate the existence of an optimal

crosslink density as well as Tg range for the investigated

copolymer system.

Two different radiation-curable antistatic monomers

(RCAMs), suitable for the production of antistatic coatings, were

synthesized by H.K. Kim et. al. [28] reacting N,N-

dimethylethanolamine and glycidyl methacrylate with

trifluoroacetic acid (RCAM I) and acetic acid (RCAM II),

respectively.In order to compare the curing behavior of RCAM I

and RCAM II with conventional monomers, the

photopolymerization of RCAM I, RCAM II, hydroxy propyl acrylate

(HPA) and hydroxy ethyl methacrylate (HEMA) were investigated

by differential photo calorimetry. Coating properties such as

surface electrical resistance, hardness, chemical resistance, and

surface tension of the UV-cured films containing RCAM I and

RCAM II were also investigated. The results of an FTIR-ATR

depth-profile analysis showed that the fluorine in the RCAM I

was more concentrated near the surface of the samples.

A radiation curable resin has been synthesized by Johan

Samuelsson et. al. [29] from a hydroxy functional hyperbranched

polyether onto which an epoxy functional fatty acid, vernolic

acid, has been attached. The resin was cationically polymerized

in presence of different amounts of vernolic acid methyl ester as

a reactive.

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Inorganic/organic hybrid coatings were prepared using

epoxidized linseed oil with combinations of the two sol–gel

precursors (titanium (IV) isopropoxide, tetraethyl orthosilicate),

and a telechelic silicate based on a modified oligomeric

caprolactone. The coatings were UV-cured by Mark D. Soucek et.

al. [30] with sulfonium initiators which concomitantly cured the

epoxy functional organic phase and the sol–gel inorganic phase

to form a co-continuous inorganic/organic system.

4.3.24.3.24.3.24.3.2 Characterization of UVCharacterization of UVCharacterization of UVCharacterization of UV----cured coatings cured coatings cured coatings cured coatings

Radiation-curable coatings have gained importance

because they are environmentally friendly and save more energy

than conventional heat-curable processes. Photocurable systems

consist of functional macromolecules, which undergo

polymerization and a photoinduced crosslinking reaction under

UV irradiation. The performance of UV-curable coating depends

on their formulation and cure quality. The quality of UV

radiation cure depends on lamp characteristics, photoinitiator

(PI) content, and film thickness, curing environment, substrate

and temperature.

Tom Scherzer et. al. [31] studied the performance of

photoinitiator systems under irradiation with monochromatic

light (313nm and 222nm) and explained the effect of diverse

physical and chemical factors on the kinetic behavior using FTIR

spectroscopy.

The synthesis, characterization and UV curing of

hyperbranched urethane-acrylate coating were investigated in

the study by Tasic et. al. [32]. The coating gives good

compromise between hardness and flexibility which obtained by

combining a high crosslink density with flexible segments

between the cross links and have potential to be used in

different UV curing applications.

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C.S.B. Ruiz et. al. [33] give brief description on the

influence of processing parameter, lamp characteristic, coating

thickness, UV radiation dose, cure environments, temperature,

formulation ( based on aliphatic urethane acrylate/ 1,6

hexanediol diacrylate) and also of photo initiator concentration

on UV cure of clear coatings

Effect of UV light source intensity and spectral distribution

on the photopolymerization reactions of a multifunctional

acrylated monomer was studied by J. Kindernay et. al. [34].

Author reported that the emission spectra of light source should

overlap with absorption spectra of photo- initiator for effective

curing.

A. S. Bashar et. al. [35] prepared thin films under UV

radiation using UV lamp intensity 254-313 nm from formulations

developed with three different types of oligomers: epoxy acrylate,

polyester acrylate and urethane acrylate in the presence of a

mono- functional monomer N-vinylpyrrolidone. Film hardness,

gel content and tensile properties (strength and elongation) were

studied.

M. Johansson et. al. [36] discusses the correlation

between resin structure and properties both before and after

cure for two coating systems (Powder Coating, UV Curable

coating). Author also correlated the functionality and polarity

with coating properties.

Rose A. Ryntz et. al. [37], relate the effect of Tg of base

resins, crosslink density, cross link type with scratch resistance.

Author proposed that the coatings that exhibit both hard

surfaces and tough – elastic network integrity afforded the

optimized scratch resistance behavior.

Kent.D.J et. al. [38] studied the effects of matting agent

concentration, particle size and film thickness in UV-curable

coating system and results of it indicate that the presence of

tertiary amine photoactivator reduces the degree of matting

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while good matting could be achieved even in thick film

application by careful formulation.

Xuehai Yu et. al. [39] studied the structure-property

relationship on Mechanical and Thermal properties of UV curable

Urethane and Urea acrylate. Author also highlighted the effect of

reactive diluents by studying two reactive diluents (2-

Hydroxyethyl methacrylate, N- Vinyl pyrolidone) and optimized

concentration of reactive diluents 40 % for N- Vinyl pyrolidone,

50 % for 2- Hydroxy ethyl methacrylate.

Liu, Tingdong et. al. [40] studied the effect of benzoin

butyl ether as a photo initiator in the preparation of low gloss

UV-curable coatings and found that the rate of cross linking

increases with increasing the concentration of photo initiator

and decrease with decreasing the intensity of UV-light.

Brunn, Bill L et. al. [41] studied the relative efficiencies of

several photo initiator in curing of trifunctional acrylate

monomer in both air and inert atmosphere with or without amine

synergist and curing efficiency were judged by physical test of

the coating films produced.

Kent.D.J et. al. [42] studied the parameters affecting the

matting of UV-curable urethane acrylate system. N-methyl

diethanolamine synergist and silica gel flatting agents shows

detrimental effect of synergist while coarse untreated silica gels

gave poor results.

Interfacial structural changes of UV cured urethane

acrylate coating films were investigated using ATR FTIR

spectroscopy by Kenichi Yukiyasu and Marek W. Urban [43]

.These studies show that at the film-air (F-A) interface, when

photo-initiator levels do not exceed 0.1% w/w, the band area

ratio of H-bonding to non-H bonding carbonyl stretching

vibrations is proportional to UV energy density.

A UV-curable optical fiber coating transparent in the deep

UV has been developed by F. Masson et. al. [44] to allow a Bragg

Page No.:213

grating to be directly engraved on the fiber by laser exposure

through the coating. Polydimethylsiloxane-acrylate resins were

found to give the best performance with respect to the monomer

reactivity. This optical fiber coating exhibits an excellent

photochemical resistance upon exposure to an intense UV laser

beam, thus making it suitable for engraving of a fiber grating

through the polymer coating.

The quality and performance of the polymeric materials

cured by ultraviolet (UV) / electron beam (EB) radiation depends

on the components of coating formulation, as well as the type of

radiation used in the curing process. The aim of the C.S.B Ruiz

et. al. [45] were to study and establish the correlation between

the cure degree of a clear coating irradiated with different

radiation doses of UV or EB and the tensile properties of the

polymeric films obtained. The cure degree was measured by DSC

and FTIR.

Using a rheometers coupled with a UV-light generator, a

photo-rheometry set-up has been developed by Sang Sun Lee et.

al. [46] to study the viscoelastic properties of UV-coating

systems during fast curing. Due to a high reaction rate, the

viscoelastic properties have to be evaluated using a special

procedure. This technique was found suitable to obtain reliable

rheological data during the fast photo-reaction, allowing the

determination of gel points occurring within less than 1 s.

The curing behavior of four UV curable clear coats was

examined by M.E. Nichols et. al. [47] using spectra from a

confocal Raman microscope. The disappearance of the C=C line

near 770 cm -1 provides the proof for the curing of the samples,

but quantification of the degree of cure by standard peak-fitting

and baseline subtraction methods does not work well because of

sample fluorescence, baseline shifts and overlapping peaks. The

most complete cure throughout the film thickness was obtained

with a mixture of standard and having red-shift photoinitiators.

Page No.:214

The goal of J. Kindernay et. al. [48] was to examine the

possibilities of preparing thin surface spatial crosslinked

polymer films by UV curing using 1, 6-hexandioldiacrylate as a

multifunctional monomer and 1-hydroxycyclohexyl acetophenone

as a radical photoinitiator. Different UV light sources were used

with different light spectral distributions and light intensities. It

was found that the light source characterized at least by a

particular overlap of its emission spectrum with the

photoinitator’s absorption spectrum was the best system used

for effective cure. Low polymerization rate achieved in the case

of smaller overlap of spectrums was easy to regulate by

extending the energy of the emitted light.

Recent developments of new UV curable resins, which meet

the high demands of automotive applications (e.g. weather

stability), in combination with a new lamp technology offer

extremely fast drying of paints, giving complete curing within

less than 2min (in some cases even within seconds). Since the

capacity of the painting/drying booth is the bottleneck in most

body shops and OEM lines, this new technology offers a

remarkable time saving advantage to the customer. The new

technical standard is presented by a dual cure system due to the

advantages of lower volume shrinkage and curing of shadow

areas. The change of mar and chemical resistance depending on

the amount of UV curable components in a one pack automotive

clear coat is shown. The influence of both temperature and

distance between the lamp and the painted object has been

investigated by K. Maag et. al. [49] and found the decrease of UV

curable double bonds in a given dual cure refinishing clear coat.

The light stability of water based UV-cured polyurethane-

acrylate (PUA) coatings had been tested in an accelerated QUV-A

weatherometer by C. Decker et. al. [50] . Infrared spectroscopy

was used to monitor both the ultrafast polymerization of the

acrylate double bond upon intense illumination, and the

chemical changes occurring upon photo ageing of 30 mm thick

Page No.:215

clear coats. The UV-curing reaction was hardly affected by the

addition of the HALS radical scavengers and UV absorbers

needed to improve the light stability of water based UV-cured

PUA coatings. The observed permanency of the UV-absorber after

such heavy exposure ensures a long lasting UV-screen effect of

the protective coating. Water based UV-cured PUA coatings

proved to be more resistant to hydrolysis than melamine-acrylate

thermosets.

The study focused on the use of organic phosphorous

compounds for the improvement of the corrosion protection of

carbon steel by a UV-cured polyurethane coating was presented

using two compounds by Trinh Anh Truc et. al. [51]. One with a

long hydrocarbon chain tridecylphosphate (TDP) and the second

with an unsaturated hydrocarbon chain,

methacryloxyethylphosphate (MOP). The compounds were used

either for surface treatments before the application of the

organic coating or added directly to the coating. Corrosion

resistance of the coated steel was evaluated by electrochemical

impedance spectroscopy.

Real-Time FTIR–ATR spectroscopy was used by Tom

Scherzer and Ulrich Decker et. al. [52] to study the kinetics of

photopolymerization reactions induced by monochromatic UV

light. Various photoinitiator systems were tested for their

efficiency to start the curing reaction of acrylates on irradiation

at 313 or 222 nm. The effect of physical and chemical factors

such as photoinitiator concentration, light intensity,

temperature, monomer functionality and initiation on kinetic

parameters like polymerization rate, induction period and final

conversion was studied. The contribution of the post curing to

the final conversion was determined by following the decay of the

double bonds during and after irradiation with single or multiple

short UV flashes with a duration of 50–200 ms. They also

reported, some investigations of samples from practical

applications such as UV-curable powder coatings, printing inks,

and release coatings of silicone acrylates.

Page No.:216

The use of hydroxyl-functional hyperbranched polymers

(HBPs) were studied by Marco Sangermano et. al. [53] with

respect to a UV cured epoxy system. Their presence induced an

increase of the final epoxy conversion, which was interpreted on

the basis of a chain-transfer reaction. A decrease in Tg value

and increase in density in the photo cured films were observed

when the amount of HBP additive in the photo curable

formulation was increased, indicating a decrease in the free

volume and increase in toughness due to the plasticization

effect. The coating were characterized by mechanical properties

and found very brittle and fragile.

A general overview of visible light photo induced

polymerization reactions is presented by J.P. Fouassier et. al.

[54]. Reaction mechanisms as well as practical efficiency in

industrial applications are also discussed and investigated. The

several points in detail about photochemical reactivity of

photoinitiating system (PIS) have also discussed at length about,

available photoinitiators (PIs) and photosensitizers (PSs),

mechanisms involved in selected examples of dye sensitized

polymerization reactions, examples of applications in pigmented

coatings usable as paints, textile printing, glass reinforced

fibers, sunlight curing of waterborne latex paints, curing of inks,

laser-induced polymerization reactions, high speed

photopolymers for laser imaging, PISs for computer-to-plate

systems.

The inhibitory effect of molecular oxygen in the

photoinitiated polymerization of acrylate resins had been

completely eliminated by operating in a carbon dioxide

atmosphere by Katia Studer et. al. [55]. The high speed

polymerization was followed in situ by real time infrared

spectroscopy, thus allowing conversion versus time curves to be

recorded for curing reactions occurring within a fraction of a

second. The influence of the O2 concentration and of the sample

temperature on the polymerization kinetics has been quantified

Page No.:217

for a polyurethane-acrylate resin. Replacing air by CO2 proved to

be particularly beneficial for polymerizations carried out under

conditions where O2 diffusion was enhanced, i.e. thin films of a

highly fluid resin exposed to low intensity light at high

temperatures.

The photoinitiated radical polymerization of acrylate resins

had been shown by Katia Studer et. al. [56] to proceed more

rapidly and extensively in a carbon dioxide atmosphere than in

the presence of air. Polymerization profiles were recorded by

real-time infrared spectroscopy for a few micron thick coatings

exposed for 1 s to UV radiation. The importance of O2 inhibition

were shown to depend on a number of factors, such as the

nature and concentration of the photoinitiator, the reactivity and

viscosity of the acrylate monomer, and the wavelength and

intensity of the UV radiation. CO2 inerting was required for

achieving an effective surface cure of poorly reactive

formulations exposed to UV light of low intensity.

The influence of prepolymer (urethane acrylate or

polyesteracrylate) type, triacrylate (trimethyolpropane triactylate

or ethoxylated trimethylolpropane triacrylate) type and the

concentration of silicone acrylate on the surface properties of UV

cured films were studied by H.K.Kim et. al. [57]. The effect of

these variables on the pencil hardness and gloss was determined

by using a full factorial experimental design. The results showed

that the prepolymer type and the concentration of silicone

acrylate were the most significant factors affecting surface

hardness and gloss of UV cured films, respectively. Specifically,

the coating formulation with polyester prepolymer resulted in

improved surface hardness of the UV cured film, while

increasing the concentration of the silicone acrylate significantly

decreased the gloss. In addition, the predictive mathematical

models obtained through analysis of variance provide a

reasonable approximation of actual experimental measurements.

Page No.:218

Mingzhe Wang et. al. [58] discuss the stages of the curing

process during the preparation of a polymer-network-dispersed

liquid crystal from liquid crystal, based on methacrylate and

dimethacrylate esters under UV irradiation. The morphology of

each stage was measured by scanning electron microscopy. The

effects of the irradiation time on the morphology are discussed.

The relationship between the morphology of the polymer matrix

and its electro-optical properties was investigated.

Relationship between pigment properties and UV-curing

efficiency were effectively studied by Reiner Jahn and Tunja

Jung [59] and developed novel class of photoinitiators based on

bis-acylphosphinoxides (BAPO) and achieved one step to cure

colored coatings effectively.

4.44.44.44.4 Present WorkPresent WorkPresent WorkPresent Work

After thorough understanding of UV-curable coating

formulations from the literature survey, their utilization in

various high performance applications and also of the various

curing techniques, it was decided to prepare the urethane

acrylate based coating compositions using most common and

commercially used reactive diluents with varying

functionalities. Thus in the present study range of UV-curable

coating formulations based on Urethane acrylate oligomers

(Chapter-3) are prepared and characterized for ascertaining their

successful application as high performance low VOC coatings.

4.54.54.54.5 ExperimentalExperimentalExperimentalExperimental

4.5.14.5.14.5.14.5.1 Material and MethodsMaterial and MethodsMaterial and MethodsMaterial and Methods

Urethane acrylate oligomers used were as prepared and

characterized in Chapter 3.

Trimethylol Propane Trimethacrylate (TMPTMA) was

procured from the Aldrich, USA.

Page No.:219

Benzophenone and Dimethyl amino ethanol (DMEA) were

procured from Chiti-Chem. Corporation, Baroda.

The chemical structures of the above materials are shown

in Figure: 1 and the physical properties are given in Table 1.

4.5.24.5.24.5.24.5.2 UV curable coating formulationUV curable coating formulationUV curable coating formulationUV curable coating formulation

The Urethane acrylate oligomer was taken into beaker and

stoichiometric amount of reactive diluents and photo initiator

were stirred at room temperature. The amount of each ingredient

used in formulation for preparing the coating compositions is

shown in Table 2.

4.5.34.5.34.5.34.5.3 Application and curing Application and curing Application and curing Application and curing coating compositicoating compositicoating compositicoating composition:on:on:on:

Sample to be tested for UV-curing was coated onto MS steel

test panels (15 cm x 5 cm) as follows. An excess of the sample

was placed at one end of the test panel and using a rod

applicator (K-Bar No.5) drawn across the substrate with even

pressure pushing excess material off the edge. This method

produced coating with average wet fi lm thickness of 23-26 µm.

For the curing of above test panels, The coated panel was

exposed to a (200 Watt/inch) (280-360nm) medium pressure

mercury vapor lamp of UV-2KW-2-35 curing system for 1.5-2.0

min. This method produced coating with average wet film

thickness of 23-35 µm.

4.64.64.64.6 Coating EvaluationCoating EvaluationCoating EvaluationCoating Evaluation

The cured film of all above coating compositions were

characterized for various mechanical properties like adhesion,

flexibility, impact resistance and scratch resistance. The films

were also evaluated for their chemical, corrosion and solvent

resistance as per standard methods of their characterization

described in the literature. [60] The results of the film

characterization are reported in Table: 6-11. These cured films

were also characterized for IR- Spectra.

Page No.:220

4.6.14.6.14.6.14.6.1 Adhesion and Flexibility: (ASTM D 3359 & Adhesion and Flexibility: (ASTM D 3359 & Adhesion and Flexibility: (ASTM D 3359 & Adhesion and Flexibility: (ASTM D 3359 &

ASTM D 522)ASTM D 522)ASTM D 522)ASTM D 522)

For the adhesion test [61], a number of parallel cuts are

made through the film up to the substrate at 1 mm distance

using a sharp knife. These are crossed by a second series of cuts

making numbers of 1 mm x 1mm squares to make 100 squares.

If the adhesion is poor some of these squares will pullout and

result is expressed as failure. If the severity of the test needs to

be increased, it can be performed by pressing a strip of adhesive

tape across the squares followed by a quick pull off. The results

for all cured film are shown in respective tables.

For the flexibility [62] test, the coated panel is placed

under a mandrel of prescribed diameter embodied in a hinge

(coated side) the panel is then bent through 180O in 1 sec. After

removing the panel, the band is examined for cracks and loss of

adhesion. The results of cured films are shown in respective

tables.

4.6.24.6.24.6.24.6.2 ImpactImpactImpactImpact Resistance: ASTM D 2794 Resistance: ASTM D 2794 Resistance: ASTM D 2794 Resistance: ASTM D 2794

It is the resistance of organic coatings to the effects of

rapid deformation (impact). The impact resistance [63] of

different cured films in the present study was evaluated as per

standard method using a heavy- duty tubular impact tester with

2 lbs mass and 25 inch height with round nose punch according

to IS- 101-1989 method. The impact area was observed for

cracks in the coating and accordingly reported as passed or

failed. The results for the impact resistance of all cured films

were shown in respective tables.

Page No.:221

4.6.34.6.34.6.34.6.3 Scratch Hardness [64]Scratch Hardness [64]Scratch Hardness [64]Scratch Hardness [64]

The coated panel is fixed in a horizontal position on the

apparatus having a needle in vertical position with

hemispherical hardened steel point with 1 mm diameter,

attached to a counter balance arms. This arm is lowered at the

time of test so that the needle comes in contact with the coated

panel. The weight is placed on arm and then it is lowered gently

on coated panel. The needle is pulled across the panel at

constant rate by the machine and the lightening of the red light

is observed during this process. If there is no lightening of red

light, the needle is shifted by about 10 mm and more weight is

placed on the needle. It is again pulled as earlier and the

lightening of red light is checked. If red light gets ON, it

indicates that needle has reached the substrate indicating

failure of coating. The result is recorded as the maximum load,

which needed to apply to the needle before bare metal is visible

through scratch. The results for all cured films are reported in

respective tables.

4.6.44.6.44.6.44.6.4 Dry film Thickness ASTMD 1186 [65]Dry film Thickness ASTMD 1186 [65]Dry film Thickness ASTMD 1186 [65]Dry film Thickness ASTMD 1186 [65]

The thickness of dry films is measured by the coat meter

for ferrous substrates based on a permanent magnet. It uses the

principle that the attractive force of the magnet to the substrate

varies inversely with thickness of applied film. The results are

given in respective tables.

4.6.54.6.54.6.54.6.5 Chemical Resistance ASTMD 1308 [65]Chemical Resistance ASTMD 1308 [65]Chemical Resistance ASTMD 1308 [65]Chemical Resistance ASTMD 1308 [65]

The chemical resistance of the cured films is measured by

the immersion of the coated panel in 5 % of the acid as well as

alkali solution. After immersion the test, panels were observed

from time to time for any deterioration of the film. The results

for all cured films are given in respective tables.

Page No.:222

4.6.64.6.64.6.64.6.6 Solvent Resistance ASTM D 5402 [65]Solvent Resistance ASTM D 5402 [65]Solvent Resistance ASTM D 5402 [65]Solvent Resistance ASTM D 5402 [65]

The solvent resistance of the cured film is measured by the

solvent rub test. The coated panels were rubbed with ethyl

methyl ketone soaked cotton pad. Any changes in the

appearance or deterioration of the film are observed. The results

are reported in respective tables.

Page No.:223

4.74.74.74.7 Result and Discussion:Result and Discussion:Result and Discussion:Result and Discussion:

4.7.14.7.14.7.14.7.1 Adhesion and Flexibility:Adhesion and Flexibility:Adhesion and Flexibility:Adhesion and Flexibility:

Adhesion and Flexibility are the prime important

characteristics of all coatings. To function effectively and

satisfactorily, the surface coatings must adhere well and should

not be affected by any mechanical abuse.

The results of flexibility and adhesion shown in the Table:

6-8 reveals the excellent performance of most of the

experimental batches based on Dehydrated Castor, Jathropha

and Sesame oil. The compositions DCET-1ar,DCET-1al, DCDT-

1ar, DCDT-1al, DCTT-1ar, DCTT-1al, JET-1ar, JET-1al, JDT-1ar,

JDT-1al, JGT-1ar, SET-1ar, SET-1al, SDT-1ar, SDT-1al, STT-1ar

STT-1al, SGT-1ar, SGT-1al based on Dehydrated Castor oil,

Jathropha oil and Sesame oil showed poor performance. This can

be attributed to the lower oil ratio, higher functionality of polyol

and aromatic type of Isocyanate [66].

The higher extent of the adhesion and flexibility reveals

that most of the experimental sets showed satisfactory

performance.

4.7.24.7.24.7.24.7.2 Impact Resistance:Impact Resistance:Impact Resistance:Impact Resistance:

The result of impact resistance showed the similar trend in

all above mentioned experimental sets. The reason of

satisfactory impact resistance can be assigned to the

inclusion of oil in the dry film. The long fatty chain having

more number of carbon atoms contribute to good flexibility

and impact resistance to the cured film.

4.7.34.7.34.7.34.7.3 Scratch Hardness:Scratch Hardness:Scratch Hardness:Scratch Hardness:

The results of scratch resistance are shown in Table: 6-8

for Dehydrated Castor, Jathropha and Sesame oil respectively.

As we proceed from DCO to JO to SO, the degree of unsaturation

increases, this is obvious from their Iodine value data as shown

in Table. In case of dry film formation by UV-light curing, the

unsaturation present in the oil also participates into improved

cross linking via the double bond of fatty acid. This leads to

Page No.:224

better homogeneity, better film integrity and packing of the

polymer chains. Also the aromatic nature of the isocyanate

moiety further enhances the film hardness and toughness.

Thus the experimental sets based on higher functionality

polyol TMP, Glycerine, higher functionality of acrylate reactive

diluent (TMPTMA) and lower proportion of oil gave better scratch

hardness. This can be seen in the results of DCTT-3ar, DCTT-

3al, DCGT-3ar, DCGT-3al, JTT-3ar, JTT-3al, JGT-3ar, JGT-3al,

STT-3ar, STT-3al, SGT-3ar, and SGT-3al. Also in an equivalent

experimental set with similar ingredient proportion but different

type of oil, the sets with Dehydrated Castor oil gave superior

performance as compared to JO and SO. This can be attributed

to their difference in terms of Iodine value.

4.7.44.7.44.7.44.7.4 Chemical Resistance and Solvent resistance:Chemical Resistance and Solvent resistance:Chemical Resistance and Solvent resistance:Chemical Resistance and Solvent resistance:

The results of chemical and solvent resistance as shown in

Table: 9-11 are quite encouraging in terms of cured coating

performance. The higher cross linking density (XLD) in

respective experimental sets showed improved solvent and

chemical resistance of the cured films. Also the acid and alkali

resistance of the films based on lower proportion of oil gave

better results. This could be due to lower ester linkages which

are vulnerable to acid and alkali attack. Thus more number of

polyurethanes gives better chemical resistance [67].

4.7.54.7.54.7.54.7.5 IR IR IR IR –––– Spectroscopy: Spectroscopy: Spectroscopy: Spectroscopy:

The IR spectra were scanned for monitoring the presence of

unsaturation in the resin (due to acrylate groups) as well for

their utilization during UV-radiation giving cured coating films.

The disappearance of the band at 815 cm -1, 770 cm -1 frequency

region was monitored for the extent of curing. It was found that

the band intensity increases as the urethane acrylate resin was

mixed with reactive diluents (Figure:1,3&5) and after the

irradiating of coating compositions with UV Light the intensity

decreases significantly as shown in the IR spectrum of cured

film (Fig.2,4&6). This observation clearly confirms the

participation of reactive diluents in curing of film.

Page No.:225

4.84.84.84.8 ConclusionConclusionConclusionConclusion

The UV-curable coatings based on Modified polyols from

renewable resources like dehydrated castor oil, Jathropha oil

and Sesame oil were prepared satisfactorily and show good

curing characteristics. The physico-chemical properties of the

urethane-acrylate oilgomers as well as the final coating

compositions containing of reactive diluent and photoinitiator

were in quite agreement with the currently used equivalent

polyester and epoxy as well as urethane acrylates. The

instrumental analysis confirmed the satisfactory synthesis of

urethane acrylates and coating compositions. As all these

compositions do not contain the volatile organic solvents, which

contribute to Volatile Organic Compounds (VOC’s), the resulting

coatings are eco-friendly and meeting the legislative

requirements by the various regulatory authorities in the field of

Surface Coatings. The performance of the cured film confirms

their successful curability in presence of Photo initiator

(Benzophenone) and UV-light source. Also the results of the

cured films lead us to conclude, the potential utilization scope of

these urethane acrylates UV-curable coatings for high

performance eco-friendly industrial coating applications. It is to

be noted that since the prices of these oils are not high, the

production of the said UV curable resins will be economically

viable in the context of Indian economy.

Trimethylol Propane Trimethacrylate (TMPTMA)

Page No.:226

Table:Table:Table:Table:----1111 Physical Properties of Reactive Diluents Physical Properties of Reactive Diluents Physical Properties of Reactive Diluents Physical Properties of Reactive Diluents

and Cross linkers.and Cross linkers.and Cross linkers.and Cross linkers.

Sr

No. Property

2- Hexyl Ethyl

Metha Acrylate

(2-HEMA)

Trimethylol

Propane

Trimethacrylate.

(TMPTMA)

1. Physical

Appearance

Clear, water white,

liquid

Clear, water

white liquid

2. Refractive Index

@ 28oC 1.433 1.4701

3. Density @ 25oC 0.880 1.061

4.

Brookfield

Viscosity (cPs) @

25oC

5 44

5. Flow Time (sec)

F.C No.4 @ 25oC 18 45

Table:Table:Table:Table:---- 2 2 2 2 Composition of UV Curable coatingsComposition of UV Curable coatingsComposition of UV Curable coatingsComposition of UV Curable coatings

Sr.

No. Ingredient Wt% Function

1. Urethane Acrylate 70% Oligomer

2. TMPTMA 25% Reactive diluents as Crosslinking

Monomer

3. Benzophenone 3.50% Photointiator

4. DMEA 1.50% Activator/Catalyst

Total 100%

TMPTMA - TrimethylolPropaneTrimethacrylate

DMEA - DimethylEthanolAmine

Page No.:227

Table:Table:Table:Table:----3 3 3 3 Physical Property of UV coatings based Physical Property of UV coatings based Physical Property of UV coatings based Physical Property of UV coatings based

on Dehydrated castor Oil on Dehydrated castor Oil on Dehydrated castor Oil on Dehydrated castor Oil

Description code Colour

(Gardner Scale ) Viscosity (cPs) Wt/Ltr

DCET-1ar 4 280 1.07

DCET-1al 3 260 1.08

DCET-2ar 3 310 1.08

DCET-2al 3 290 1.08

DCET-3ar 3 450 1.10

DCET-3al 2 350 1.10

DCDT-1ar 3 360 1.08

DCDT-1al 3 280 1.08

DCDT-2ar 2 450 1.08

DCDT-2al 2 350 1.08

DCDT-3ar 2 520 1.10

DCDT-3al 2 420 1.10

DCTT-1ar 3 345 1.08

DCTT-1al 3 345 1.08

DCTT-2ar 3 450 1.10

DCTT-2al 3 380 1.10

DCTT-3ar 2 540 1.10

DCTT-3al 2 490 1.10

DCGT-1ar 3 350 1.07

DCGT-1al 3 250 1.08

DCGT-2ar 3 490 1.08

DCGT-2al 3 330 1.08

DCGT-3ar 2 520 1.10

DCGT-3al 2 420 1.10

Page No.:228

Table:Table:Table:Table:----4 4 4 4 Physical Property of UV coatings basedPhysical Property of UV coatings basedPhysical Property of UV coatings basedPhysical Property of UV coatings based

on Jathrophaon Jathrophaon Jathrophaon Jathropha oil oil oil oil

Description code Colour

(Gardner Scale)

Viscosity

(cPs) Wt/Ltr

JET-1ar 4 460 1.06

JET-1al 4 425 1.06

JET-2ar 3 510 1.08

JET-2al 3 510 1.08

JET-3ar 2 650 1.10

JET-3al 2 650 1.10

JDT-1ar 4 460 1.07

JDT-1al 4 460 1.07

JDT-2ar 2 570 1.09

JDT-2al 2 550 1.08

JDT-3ar 2 650 1.10

JDT-3al 2 650 1.10

JTT-1ar 3 580 1.07

JTT-1al 3 565 1.08

JTT-2ar 2 650 1.09

JTT-2al 3 650 1.10

JTT-3ar 3 960 1.11

JTT-3al 2 840 1.10

JGT-1ar 4 650 1.07

JGT-1al 4 650 1.07

JGT-2ar 4 710 1.08

JGT-2al 3 690 1.08

JGT-3ar 2 780 1.10

JGT-3al 2 720 1.10

Page No.:229

Table:Table:Table:Table:----5 5 5 5 Physical Property of UV coatings based Physical Property of UV coatings based Physical Property of UV coatings based Physical Property of UV coatings based

on Sesame oilon Sesame oilon Sesame oilon Sesame oil

Description code Colour

(Gardner Scale)

Viscosity

(cPs) Wt./Ltr.

SET-1ar 5 425 1.05

SET-1al 3 450 1.07

SET-2ar 4 460 1.07

SET-2al 3 540 1.08

SET-3ar 3 590 1.08

SET-3al 2 650 1.08

SDT-1ar 5 435 1.05

SDT-1al 3 480 1.08

SDT-2ar 4 470 1.07

SDT-2al 2 560 1.09

SDT-3ar 4 690 1.08

SDT-3al 2 650 1.11

STT-1ar 3 580 1.06

STT-1al 3 565 1.08

STT-2ar 2 750 1.09

STT-2al 3 630 1.10

STT-3ar 3 900 1.10

STT-3al 2 820 1.11

SGT-1ar 4 670 1.07

SGT-1al 4 650 1.07

SGT-2ar 4 680 1.09

SGT-2al 3 695 1.09

SGT-3ar 2 740 1.10

SGT-3al 2 785 1.11

Page No.:230

Table:Table:Table:Table:----6 6 6 6 Mechanical property of UV cured Mechanical property of UV cured Mechanical property of UV cured Mechanical property of UV cured

coatings bcoatings bcoatings bcoatings based on ased on ased on ased on Dehydrated Castor oilDehydrated Castor oilDehydrated Castor oilDehydrated Castor oil

Description Code

Scratch Hardness

(gms)

Impact Hardness lb inch

Pencil Hardness

Flexibility 1/8”

mandrel

Cross Hatch

Adhesion (%)

DFT Microns

(ụ )

DCET-1ar 1000 F 2H F F 23

DCET-1al 1050 F 3H F F 24

DCET-2ar 1300 P 3H P P 23

DCET-2al 1250 P 3H P P 23

DCET-3ar 1650 P 4H P P 24

DCET-3al 1750 P 4H P P 24

DCDT-1ar 1150 F 3H F F 23

DCDT-1al 1100 F 3H F F 23

DCDT-2ar 1400 P 3H P P 24

DCDT-2al 1400 P 3H P P 24

DCDT-3ar 2050 P 4H P P 24

DCDT-3al 2000 P 4H P P 24

DCTT-1ar 1250 F 2H F F 24

DCTT-1al 1250 F 2H F F 24

DCTT-2ar 1500 P 3H P P 25

DCTT-2al 1500 P 3H P P 24

DCTT-3ar 2100 P 4H P P 25

DCTT-3al 2100 P 4H P P 25

DCGT-1ar 1000 F 3H F P 24

DCGT-1al 1000 F 3H F P 24

DCGT-2ar 1650 P 4H P P 24

DCGT-2al 1600 P 4H P P 24

DCGT-3ar 2150 P 4H P P 25

DCGT-3al 2150 P 4H P P 25

P-Pass F-Fail

6H>5H>4H>3H>2H>1H>H>HB>1HB>2HB>3HB>4HB>5HB>6H

Page No.:231

Table:Table:Table:Table:----7 7 7 7 MechanicaMechanicaMechanicaMechanical property of UV cured l property of UV cured l property of UV cured l property of UV cured

coaticoaticoaticoatings ngs ngs ngs based on Jathropha oilbased on Jathropha oilbased on Jathropha oilbased on Jathropha oil

Description Code

Scratch Hardness

(gms)

Impact Hardness lb inch

Pencil Hardness

Flexibility 1/8”

mandrel

Cross Hatch

Adhesion (%)

DFT Microns

(ụ )

JET-1ar 1000 F 3H F F 23

JET-1al 850 F 2H F F 23

JET-2ar 1400 F 4H P P 24

JET-2al 1000 P 2H P P 24

JET-3ar 1600 P 4H P P 24

JET-3al 1350 P 3H P P 24

JDT-1ar 950 F 3H F F 23

JDT-1al 800 F 3H F F 23

JDT-2ar 1600 P 3H P P 23

JDT-2al 900 P 3H P P 24

JDT-3ar 1900 P 4H P P 23

JDT-3al 1500 P 4H P P 24

JTT-1ar 1200 F 2H F F 24

JTT-1al 1000 F 2H F F 23

JTT-2ar 1900 P 3H P P 25

JTT-2al 1500 P 3H P F 25

JTT-3ar 2000 P 5H P P 26

JTT-3al 2100 P 4H P P 25

JGT-1ar 1200 F 2H F P 26

JGT-1al 1000 F 3H F P 24

JGT-2ar 1800 P 4H P P 26

JGT-2al 1600 P 4H P p 24

JGT-3ar 2100 P 5H P P 26

JGT-3al 1800 P 4H P P 25

P-Pass F-Fail

6H>5H>4H>3H>2H>1H>H>HB>1HB>2HB>3HB>4HB>5HB>6HB

Page No.:232

Table:Table:Table:Table:----8 8 8 8 Mechanical property of UV cured Mechanical property of UV cured Mechanical property of UV cured Mechanical property of UV cured

coatings based on Sesamecoatings based on Sesamecoatings based on Sesamecoatings based on Sesame oil oil oil oil

Description Code

Scratch Hardness

(gms)

Impact Hardness lb inch

Pencil Hardness

Flexibility 1/8”

mandrel

Cross Hatch

Adhesion (%)

DFT Microns

(ụ )

SET-1ar 950 F 3H F F 23

SET-1al 700 F 2H F F 23

SET-2ar 1500 F 3H P P 23

SET-2al 1000 P 2H P P 24

SET-3ar 2100 P 4H P P 24

SET-3al 1800 P 1H P P 23

SDT-1ar 900 F 3H F F 22

SDT-1al 700 F 3H F F 23

SDT-2ar 1800 P 3H P P 23

SDT-2al 900 P 3H P P 23

SDT-3ar 1800 P 4H P P 23

SDT-3al 1500 P 4H P P 24

STT-1ar 1000 F 2H F P 24

STT-1al 900 F 3H F P 23

STT-2ar 1900 P 4H P P 26

STT-2al 1500 P 2H P F 25

STT-3ar 2000 P 5H P P 26

STT-3al 1950 P 1H P P 27

SGT-1ar 1000 F 2H F P 26

SGT-1al 1000 F 2H F P 24

SGT-2ar 1800 P 4H P P 26

SGT-2al 1600 P 4H P p 24

SGT-3ar 1900 P 5H P P 26

SGT-3al 1800 P 4H P P 26

P-Pass F-Fail

6H>5H>4H>3H>2H>1H>H>HB>1HB>2HB>3HB>4HB>5HB>6HB

Page No.:233

Table:Table:Table:Table:----9999 Chemical Property of UV cured coatings Chemical Property of UV cured coatings Chemical Property of UV cured coatings Chemical Property of UV cured coatings

based on Dehydrated Castor obased on Dehydrated Castor obased on Dehydrated Castor obased on Dehydrated Castor oil il il il

Description Code

Acid Resistance

5%HCl

Alkali Resistance 5%NaOH

Corrosion Resistance

5%Nacl

MEK Double rub

DCET-1ar 4 3 4 65

DCET-1al 4 3 3 55

DCET-2ar 4 4 4 65

DCET-2al 4 4 4 60

DCET-3ar 5 5 5 85

DCET-3al 5 4 5 75

DCDT-1ar 3 4 4 65

DCDT-1al 3 4 4 65

DCDT-2ar 4 5 4 70

DCDT-2al 4 4 4 70

DCDT-3ar 5 5 5 85

DCDT-3al 5 5 5 85

DCTT-1ar 4 4 5 65

DCTT-1al 4 4 5 70

DCTT-2ar 5 4 5 85

DCTT-2al 5 4 5 85

DCTT-3ar 5 5 5 95

DCTT-3al 5 5 5 95

DCGT-1ar 4 4 4 65

DCGT-1al 4 4 4 65

DCGT-2ar 5 5 5 75

DCGT-2al 5 5 5 85

DCGT-3ar 5 5 5 95

DCGT-3al 5 5 5 95

0 Film completely removed 3 Loss of gloss 1 Film cracked and partially removed 4 Slight loss of gloss 2 Film partially cracked 5 Film Practically unaffected

Page No.:234

Table:Table:Table:Table:----10101010 ChemicaChemicaChemicaChemical property of UV curedl property of UV curedl property of UV curedl property of UV cured coatings coatings coatings coatings

based on Jathropha oilbased on Jathropha oilbased on Jathropha oilbased on Jathropha oil

Description Code

Acid Resistance

5%HCl

Alkali Resistance 5%NaOH

Corrosion Resistance

5%Nacl

MEK Double rub

JET-1ar 2 3 3 55

JET-1al 2 3 3 50

JET-2ar 3 3 4 55

JET-2al 3 3 3 55

JET-3ar 5 5 4 65

JET-3al 5 5 4 65

JDT-1ar 3 3 4 55

JDT-1al 3 3 4 55

JDT-2ar 4 4 4 60

JDT-2al 4 4 4 60

JDT-3ar 5 5 5 80

JDT-3al 5 4 5 80

JTT-1ar 4 3 3 65

JTT-1al 4 3 3 65

JTT-2ar 4 4 5 70

JTT-2al 4 4 5 70

JTT-3ar 5 5 5 75

JTT-3al 5 5 5 75

JGT-1ar 3 4 3 65

JGT-1al 4 3 3 65

JGT-2ar 5 4 5 75

JGT-2al 5 4 5 75

JGT-3ar 5 5 5 85

JGT-3al 5 5 5 85

0 Film completely removed 3 Loss of gloss 1 Film cracked and partially removed 4 Slight loss of gloss 2 Film partially cracked 5 Film Practically unaffected

Page No.:235

Table:Table:Table:Table:----11111111 Chemical Property of UV Chemical Property of UV Chemical Property of UV Chemical Property of UV cured coatings cured coatings cured coatings cured coatings

based on Sesame oilbased on Sesame oilbased on Sesame oilbased on Sesame oil

Description Code

Acid Resistance

5%HCl

Alkali Resistance 5%NaOH

Corrosion Resistance

5%Nacl

MEK Double rub

SET-1ar 4 3 4 55

SET-1al 3 2 4 45

SET-2ar 4 4 5 65

SET-2al 3 3 4 65

SET-3ar 5 5 5 85

SET-3al 4 5 5 85

SDT-1ar 4 4 3 65

SDT-1al 4 3 3 55

SDT-2ar 4 5 4 65

SDT-2al 4 4 4 60

SDT-3ar 5 5 5 85

SDT-3al 5 4 5 85

STT-1ar 4 4 5 65

STT-1al 4 3 4 65

STT-2ar 5 4 5 85

STT-2al 4 5 5 85

STT-3ar 5 5 5 95

STT-3al 5 5 5 90

SGT-1ar 4 4 4 65

SGT-1al 3 4 4 65

SGT-2ar 4 5 5 75

SGT-2al 5 4 5 75

SGT-3ar 5 5 5 95

SGT-3al 5 5 5 95

0 Film completely removed 3 Loss of gloss

1 Film cracked and partially removed 4 Slight loss of gloss

2 Film partially cracked 5 Film Practically unaffected

Page No.:236

FigureFigureFigureFigure: 1: 1: 1: 1 Dehydrated Castor ODehydrated Castor ODehydrated Castor ODehydrated Castor Oil Based Urethane il Based Urethane il Based Urethane il Based Urethane

Acrylate with Reactive DiluentAcrylate with Reactive DiluentAcrylate with Reactive DiluentAcrylate with Reactive Diluent

Page No.:237

FigureFigureFigureFigure: 2: 2: 2: 2 Dehydrated Castor Oil Based Dehydrated Castor Oil Based Dehydrated Castor Oil Based Dehydrated Castor Oil Based UV Coating UV Coating UV Coating UV Coating

FilmFilmFilmFilm

Page No.:238

FigureFigureFigureFigure: 3: 3: 3: 3 Jethropha Jethropha Jethropha Jethropha OilOilOilOil Based UrethaneBased UrethaneBased UrethaneBased Urethane Acrylate Acrylate Acrylate Acrylate

with Reactive Diluentwith Reactive Diluentwith Reactive Diluentwith Reactive Diluent

Page No.:239

FigureFigureFigureFigure: 4: 4: 4: 4 Jethropha Jethropha Jethropha Jethropha Oil Based Oil Based Oil Based Oil Based UV Coating FilmUV Coating FilmUV Coating FilmUV Coating Film

Page No.:240

FigureFigureFigureFigure: 5: 5: 5: 5 Sesame Sesame Sesame Sesame OilOilOilOil BBBBased Urethaneased Urethaneased Urethaneased Urethane Acrylate Acrylate Acrylate Acrylate

with Reactive Diluentwith Reactive Diluentwith Reactive Diluentwith Reactive Diluent

Page No.:241

FigureFigureFigureFigure: 6: 6: 6: 6 Sesame Sesame Sesame Sesame Oil Based Oil Based Oil Based Oil Based UV Coating FilmUV Coating FilmUV Coating FilmUV Coating Film

Page No.:242

Reference:Reference:Reference:Reference:

1. Sokol, A., "Zero V.O.C. Paints and Coatings: Quantum

Mechanics in Paint Can”, Society of Manufacturing

Engineers, Finishing, Rosemont, IL, (1997).

2. Goto Hideki, Tanaka Junji, Eguchi Toshimasa, Takenaka

Tsuyoshi, Oshmo, Shinji, PCT Int. Appl. WO 01 26 876, 19

April 2001, C.A. 296,948 m, Vol. 134, No.21 (2001).

3. Tanaka, Kazunori, Suzuki Atsushi, Hattori Tomoyuki, JP

2000 292 661, JPN Kokai Tokkyo Koho, C.A. 310 975 f ,

Vol. 133, No 22 (2000).

4. Chrisine C. E. “Coatings World”, Vol.9, pp. 28-32 (2004).

5. Kerry Pianoforte, “Coatings World”, Vol. 10, No. 4, pp. 30-

33 (2005).

6. C.M. Seubert, M. E. Nichols. “Progress in Organic

Coatings”, Vol.49, No.3, pp. 218- 244, (2004).

7. Thompson Justin et al. US 250.492. 22, 0061079 , Appl,

(2004).

8. Alexander Efron, “Light”, Second Edin, Vakils, Feffer and

Simons Private Ltd., Bombay, pp. 79-80, (1969).

9. R. W. Stowe, “Journal of Coating Technology”, Vol. 1, No.4,

pp. 30-36 (2004).

10. Zeno. W. Wicks, “Organic Coatings: Science and Technology,

Application, Properties, Performance”. John-Wiley and Sons

Inc., Vol. II, pp. 213 (1992).

11. J. V. Crivello, K. Dietiker. “Chemistry and Technology of UV

& EB formulation for coatings, Inks & paints, Photo

initiators for f ree radical , cationic, and anionic photo

polymerization” , II edition, Wiley-SITA series, Vol. III,

(2003).

12. Pacifici J.G., Newland G. C. US Patent, 4,134,809, (1979).

13. S.C.Jain, “Paintindia”, Vol. LIX (3) pp. 50-72, (2004).

Page No.:243

14. Li Jun, Ju Xuecheng, Yi Min, Wei Jishan, Ha Hongfei,

“Radiation Physics and Chemistry”, Vol. 55, pp.99-101

(1999).

15. Cook P. M., Kelley S.S., US Patent 5, 082, 914, (1992).

16. E.Dzunuzovic, S.Tasic, B.Bozic, D.Babic, B.D. “Progress in

Organic Coating”. Vol.52, No.2, pp.136-143 (2005).

17. C.S.B Ruiz, L.D.B. Machado, E.S. Pino, M.H.O Sampa,

“Radiation Physics and Chemistry”, Vol. 63, pp.481-483

(2002).

18. Koehler,M, Ohgemuh, J (E Merck, Darmstadt Fed Rep Ger)

Polym. Paint Colour J (1988) C.A. 109. 24258k (1988).

19. Chiocchetti, Petro (Galstaff Ind. Chem S.P.A Mornago,

Italy) “Polymer Paint Colour J”, 1988 178 (4216),

450,452,468 (Eng) C.A 109. 75303d (1988).

20. Mannfolk, Anders; Saxberg, Jom; Tuovinen, Juhani PCT Int

Appl WO 87 04,448 CCI (09D3/40) 1987. C.A 108. 77480n

(1988).

21. Hongbo Liu, Linliang Yu, Mingcai Chen, Zhitang Huang,

“Materials Research Bulletin”, 38, pp.1607-1612 (2003).

22 R. Bongiovanni, F. Montefusco ,A. Priola ,N. Macchioni ,S.

Lazzeri , L. Sozzi, B. Ameduri, “Progress in Organic

Coatings”, 45, pp.359-363 (2002).

23 Dirk Mestach, Derrick. R. Twene, “European coating

journal”, 04, pp. 126-131 (2005).

24. Hiedu, Yoshihire, Katayama, Shigeru, Yoshihara

Mitsuo,Tsuchiya Hiroyushi, Morikava, Keichiyn (Mitto

ElectricIndustrial Co Ltd.) Jpn. Kokai Tokkyo Koho Jp.63.

63, 757, (CI C09D3/727) 1988. C.A.109. 151577p (1988).

25. W. Rutsch, K. Dietliker, D. Leppard, M. Kiihler, L. Misevb,

G. Rist, U. Kolczak. “Progress in Organic Coatings”, 27, pp.

227-239 (1996).

Page No.:244

26. F. Burela, L. Lecampa, B. Youssefa, C. Bunela, J- M.

Saiterb, “Thermochimica Acta”, 326, pp.133-141(1999).

27. Carsten Wuertz, Alexander Bismarck, Jurgen Springer,

Rainer Koniger, “Progress in Organic Coatings”, 37, pp.117-

129 (1999).

28. H.K. Kim, Y.B. Kim, J.D. Cho, J.W. Hong, “Progress in

Organic Coatings”, 48, pp. 34-42 (2003).

29. Johan Samuelsson, Per-Erik Sundell, Mats Johansson,

“Progress in Organic Coatings”, 50, pp.193-198 (2004).

30. Mark D. Soucek, Aaron H. Johnson, Jonathan M. Wegner,

“Progress in Organic Coatings”, 51, pp. 300-311 (2004).

31. Tom Scherzer, Ulrich Decke, “Vibrational Spectroscopy”,

Vol. 19, pp.385-398 (1999).

32. Tasic, Seba, Bozic, Branilan, Dunjic, Branko (Duga Nova,

Belgrade Serbia and Mentenegro) Hemijska Industuja,

“Serbian Polymer journal”, 58 (11), pp. 503-513, (2004).

33. C.S.B. Ruiz, L.D.B. Machado, J.E. Volponi, E.S. Pino,

“Nuclear Instruments and Methods in Physics Research B”,

Vol.208, pp. 309-313 (2003).

34. J. Kindernay, A. Blazkova, J. Ruda, V. Jan¡covcova, Z.

Jakubykova, “Journal of Photochemistry and Photobiology

A: Chemistry”, Vol. 151, pp. 229-236 (2002).

35. A. S. Bashar, Mubarak A. Khan and K. M. Idriss Ali,

“Radian. Phys. Chem.”, Vol. 48, No. 3, pp. 349-354, (1996).

36. M. Johansson, T. Glauser, A. Jansson, A. Hault,

E.Malmstrom, H. Claesson “Progress in Organic Coating”,

Vol. 48, No. 2-4, pp.194-200 (2003).

37. Rose A. Ryntz, B. D. Abell, L. H. Nguyen, G. M. Pollano,

W.C. Shen, “Journal of Coating Technology”, Vol. 72, May

(2000).

Page No.:245

38. Kent.D.J; Schereider,H, (Seru Tech Grace,Worms, Fed Rep

Ger) Pitture Vernici 1987, 63 (11), 19-30 (Eng/Ital) C.A

109. 56634 w (1988).

39. Xuehai Yu, Brian p. Grady, Richard S. Reiner, S. L.

Copper, “Journal. App. Polym. Sci.”, Vol. 49, No. 11, pp.

1943-1955 (1993).

40. Liu, Tingdong, (Dep Mater Sci Eng, Tianjin, peop. Rep

China) Tuliao Gongye (1988).C.A. 109. 24263 h (1988).

41. Brunn, Bill L, (Valspar Corp Minneupolis MN USA)

Radcure‘86, Conference Proc., Deurborn, Mich. C.A 109.

130862 n (1988).

42. Kent.D.J; Schereider,H, (Congr FATIPEC)1986, 18th

(Vol21A), 353-84 (Eng) C.A 109.94787f (1988).

43. Kenichi Yukiyasu, Marek W. Urban, “Progress in Organic

Coatings”, 35, pp.247-253 (1999).

44. F. Masson, C. Decker, S. Andre, X. Andrieu, “Progress in

Organic Coatings”, 49, pp. 1-12(2004).

45. C.S.B Ruiz, L.D.B. Machado, E.S. Pino, M.H.O Sampa,

“Radiation Physics and Chemistry”, 63, pp. 481-483 (2002).

46. Sang Sun Lee, Andre Luciani, Jan-Anders E. Manson.

“Progress in Organic Coatings”, 38, pp. 193-197 (2000).

47. M.E. Nichols, C.M. Seubert , W.H. Weber , J.L. Gerlock,

“Progress in Organic Coatings”, 43, pp. 226-232 (2001).

48. J. Kindernay, A. Blazkova, J. Ruda, V. Jan¡covi¡cova, Z.

Jakubykova. “Journal of Photochemistry and Photobiology

A: Chemistry”, 151, pp. 229-236 (2002).

49. K. Maag, W. Lenhard, Helmut Loffles, “Progress in Organic

Coatings”, 40, pp. 93-97 (2000).

50. C. Decker, F. Masson, R. Schwalm, “Polymer Degradation

and Stabil ity”, 83, pp. 309-320 (2004).

Page No.:246

51. Trinh Anh Truc, Nadine Pebere, To Thi Xuan Hang, Yves

Hervaud, Bernard Boutevin, “Progress in Organic Coatings”,

49, pp. 130-136 (2004).

52. Tom Scherzer, Ulrich Decker. “Vibrational Spectroscopy”,

19, pp. 385-398 (1999).

53. Marco Sangermano, Giulio Malucelli, Roberta Bongiovanni,

Ald Priola and Adrian Harden, “Polymer International”, 54,

pp. 917-921 (2005).

54. J.P. Fouassier, X. Allonas, D. Burget, “Progress in Organic

Coatings”, 47, pp. 16-36 (2003).

55. Katia Studer, Christian Decker, Erich Beck, Reinhold

Schwalm, “Progress in Organic Coatings”, 48, pp. 92-100

(2003).

56. Katia Studer , Christian Decker , Erich Beck, Reinhold

Schwalm, “Progress in Organic Coatings”, 48, pp. 101-111

(2003).

57. H.K. Kim, J.G. Kim, J.W. Hong, “Polymer Testing”, 21, pp.

417-424 (2002).

58. Mingzhe Wang, Weidong Li, Yingfang Zou and Caiyuan

Pany, “J. Phys. Appl. Phys.”, 30, pp. 1815-1819 (1997).

59. Reiner Jahn, Tunja Jung, “Progress in Organic Coatings”,

43, pp. 50-55 (2001).

60. Konstandt F., “Organic Coating: Properties and Evaluation”

Chemical Pub. Co., New York, (1985).

61. N. Y. Paint and Varnish Prod. Club. Chisel. “Adhesion Test

Procedures” Federation of Paint and Varnish Prod.”, pp. 141

(1939).

62. IS: 1303-1983 Glossary of Terms Relating to Paints

(Second Revision), Indian Standard Institution, New Delhi,

(1984).

Page No.:247

63. Zeno. W. Wicks, “Organic Coatings: Science and Technology,

Application, Properties, Performance”, John-Wiley and Sons

Inc., Vol. II, pp. 672 (1992).

64. Morgans. W. M. “Outl ines of Paint Technology”, Edward

Arnold (Pub) Ltd., U.K.

65. Harshit B.Patel, Ph.D Thesis, Published by Department of

Chemistry, Sardar Patel University, INDIA (2005).

66. Manawwer Alam, Eram Sharmin, S.M. Ashraf, Sharif

Ahmad, “Progress in Organic Coatings”, 50, pp. 224-230

(2004).

67. P. Nylen, E. Sunderland, “Modern Surface Coatings”, Wiley,

London, pp. 213(1965).