what is the problem? - home - yococu · 8 solvents selected + green rescue *varnish removal from...

A new green product

Andrea Macchia, Laura Rivaroli, Gaia Fagiolo

YOCOCU- YOuth in COnservation of CUltural Heritage

What is the problem?...... First: Cleaning the surface. I suppose

Testing was performed with mixtures of different solvents using Teas triangle diagram of solvents

Some common mixtures employed in restoration. Note that the acronyms stem from the Italian name of the solvents. DMF= dimethylformamide; n/a = not applicable.

Mixtures Components ratio

2 A water + ammonia 1:1

3 A water + acetone + ethanol 1:1:1

4 A water + ammonia + ethanol + acetone 1:1:1:1

AB water + butylamine 1:1

ABD water + butylamine + DMF 1:1:1

Benzine 80°C–100°C Hydrocarbons n/a

Nitro thinner mixture of esters. ketones. alcohols. and aromatic hydrocarbons variable. depending on the producer

DA DMF + amyl acetate 1:1

DAN DMF + amyl acetate + nitro thinner 1:1:1

DIDAX DMF + synthetic thinner + xylol + acetone (35 + 15 + 10 + 10 mL. respectively)

3.5:1.5:1:1

Ligroina Petroleum ether. Aceton. Ethanol variable

White spirit Hydrocarbons n/a

MEK

Ligroina. MEK……………are toxic materials for the restorer and the environment

R.E.A.C.H. = Registration.Evaluation.Authorisation.of Chemicals

Green Chemistry R.E.A.C.H.

Review of M.S.D.S. ENVIRONMENT. WORKPLACE. IMPACT ON SAFETY for WORKERS

Is this applied in CH sector?

AIM

To set up a green product for the removal of old and modern varnishes

To transfer industrial products to cultural

heritage field

The result

But keep calm…

Experimentation Survey of solvents: Easy to find on the market e.g. solvents used in drug. food and painting industries Low toxicity

Production of laboratory specimens to perform cleaning tests with 9 solvents

In situ tests on real case studies

Experimentation 8 solvents selected + Green Rescue

*VARNISH REMOVAL FROM PAINTINGS USING IONIC LIQUIDS by Maria Filipa Pacheco and oth.-Departamento de Conservacao e Restauro.Universitade Nova de Lisboa. Portugal 2013)

DAMAR. RETOUCHER. PVA and PMMA*

Ageing : SUNTEST CPS + (168h and 336h)

Cleaning system: swab (Solvent: 2.5 ml )

Evaluation of cleaning efficacy (presence of residues): • Restorer’s observations • Micro FTIR • Spectrocolorimeter • UV/VIS imaging

Two paintings (18th-19th century)

4 types of varnishes + black pigment (no IR)

Red pigment + linseed oil

Canvas (15x15 cm)

Selection of Solvents

Easy to find on the market

Low toxicity - High LD50

High Boiling Point

Low Vapour Pressure

Low or No VOC

High Flash Point

No Mutagenicity. Cancerogenicity

OPPORTUNITIES GIVE BY GREEN

SOLVENT

What are Green Solvents?

• Chemicals manufactured using fermentation route /renewable resources

• Minimize the use and generation of hazardous substances

• They meet the goal to minimize environmental impact

Therefore They are – A sustainable Option

GBL – Solvents from renewable resource

• Ethanol

• Ethyl Acetate

• Paraldehyde

• 1,3-Butanediol

• Acetaldehyde diethyl acetal

• Acetic Acid

• Ethyl Lactate

• Levulinic acid and esters

Ethanol

• Renewable solvent

Molasses Ethanol

• Fermentation Reaction

• Properties & Applications

Low toxicity and pleasant odour

Possesses bactericidal and fungicidal activities Can be found as a solvent in numerous oral liquid formulations and

OTC medicines

Can be used as an extraction solvent in herbal medicinal products

Has applications in the personal care industry, paints, coatings, printing inks, flavour and fragrance industries

Ethyl Acetate

• One of the most popular Solvent

Molasses Ethanol

• Esterification reaction

Ethyl Acetate

CH3CH2OH + CH3COOH CH3COOCH2CH3 + H2O

• Properties & Applications

Low toxic and possesses fruity odour

Widely used as a solvent for API manufacturing

Used in agrochemical, personal care & Fragrance industries

In paints act as an activator or hardener

As a solvent it is pretty harmless to the environment and human beings

Ethyl Lactate

• A renewable Solvent

Molasses Lactic Acid Ethyl Lactate

• It’s an important organic ester

• Biodegradable solvent with excellent properties and low toxicity being

produced by lactic acid aqueous solution and ethanol, via an esterification

process

CH3CH(OH)CO2H + C2H5OH CH3CH(OH )CO2C2H5 + H2O

Green Acetals

Green Alcohols + Green Acetaldehyde

• Acetals can be used to replace

dichloromethane

Green Acetals

Toluene, Benzene, Xylene and

• Used in sectors - Coatings, Inks, Adhesives, Cosmetics,

Agrochemicals & potentially in any sector

Pharmaceuticals,

• Advantages - High solvent power, variable evaporation rates & polarity

Dibasic Ester (DBE)

• Environmentally friendly organic solvent derived from a plant by-product stream.

• Dibasic esters are excellent solvent substitutes in many parts cleaning and stripping

application

Low VOC (may qualify for LVP-VOC consumer product exemptions) Readily Biodegradable

Selected solvents C A S Name Chemical formula

109-87-5 Methylal C H3O C H2O C H3

108-32-7 Propylene

carbonate

C4H6O3

2568-90-3 Butylal C H3(C H2)3O C H2O (C H 2)3 C H3

109-99-9 T H F C4H8O /-CH2CH2OCH2CH2-\

646-06-0 Dioxolan 1.3 DIOXACYCLOPENTANE

67-64-1 Aceton ( C H 3 )2 C O

78-93-3 M E K C H3 C O C H2C H3

108-88-3 Toluen C7H8

105-57-7 Diethoxyethane C6H14O2

Physical properties

Green Rescue 1.04 140 91 4.2

NAME Density

g/lt

Boiling point° C Flash Point

° C

Vapour pressure

Kpa

Methylal 0.86 42.3 - 30.5 40

Propylene carbonate 1.2 242 132 0.04

Butylal 0.84 180 62 20

T H F 0.88 66 - 21.5 17

Dioxolan 1.06 76 2.5 10.1

Aceton 0.79 56 - 17 24

M E K 0.8 80 - 1 12.1

1,1-Diethoxyethane 0.83 102 102 18

Methylal

. Butylal

Ethylene carb.

T H F

Dioxolan

Aceton

M E K

Toluen

Ethanol T.O.U.

0

2

4

6

8

10

12

14

0 1 2 3 4 5 6 7 8 9

ðp

ðh

Hansen Graph

Green Rescue Area

Green Rescue Petroleum ether. Aceton. Ethanol*

* Paolo Cremonesi «L'uso dei solventi organici nella pulitura di opere policrome»

Natural and synthetic resins

WAXES

OILs

Ageing OILs Proteins

Toxicological Characteristics

Green Rescue 4300 800 No

@ D.N.E.L.(Derived No Effect Level = is an indicator for determining the hazardous effects upon human health of chemicals substances (is measured in mg and compared with cubic meter of work place during 8 ours. Evidently value is easily and rapidly reached by volatile .see Tab.2

this

Name LD50 mg/Kg @DNEL mg/m3/gg

VOC

Methylal 2000 130 100%

Propylen carbonate 34900 80 No

Butylal 6500 130 No

T H F 1650 150 100%

Dioxolan 2000 50 100%

Aceton 5800 500 100%

M E K 3300 600 100%

1,1-Diethoxyethane - - -

Ageing 168hr and 336hr Starting point Cleaning

Methylal Ethanol with 20 %

MEK

Propylen carbonate

Butylal Green rescue

T H F Dioxolane Aceton M E K

L* 40.340 40.653 40.517 41.319 40.172 40.307 40.691 39.562 40.267

a* 45.088 45.896 45.239 47.880 43.040 43.315 45.606 42.561 43.601

b* 25.775 24.319 25.328 27.779 23.685 24.068 26.013 24.119 24.406

c* 51.936 50.183 51.847 55.358 49.127 49.555 52.504 48.921 49.969

PARALOID

Starting point Ageing 168hr

L* 33.411 30.074

a* 28.844 12.148

b* 15.119 5.703

c* 32.572 13.421

Color surface without varnish

Starting point

L* 40.782

a* 43.290

b* 23.122

c* 49.727

PARALOID

RED Pigment + LINSEED OIL

GREEN RESCUE

MEK

paraloid

Methylal Dietho xyethane

Propil carbonate

Butylal Green rescue T H F

Dioxolane Acetone M E K

damar

Methylal Diethoxy ethane

Propil carbonate

Butylal Green rescue T H F

Dioxolane Acetone M E K

retoucher

Methylal Dietho xyethane

Propil carbonate

Butylal Green rescue T H F

Dioxolane Acetone M E K

PVA

Methylal Propil carbonate

Dietho xyethane

Butylal Green rescue T H F

Dioxolane Acetone M E K

Results + = low ++ = medium +++ = good ++++ = excellent

Retoucher P V A Damar Paraloid

Metilale ++ ++ + +++

Diethoxyethane +++ ++ + ++++

Propylen carbonate + + + +++

Butylal +++ ++ ++++ ++

Green Rescue ++++ ++++ ++ ++++

T H F +++ +++ +++ ++++

Dioxolane ++ ++ +++ ++++

Aceton ++ ++ + ++++

M E K +++ +++ +++ ++++

Green Rescue MEK

MEK

Green Rescue

MEK

Green Rescue

Mannequins, A. L. Casalini, fronte

Rimozione di vernici sovrammesse con strati di porporina

Armatura del XVIII secolo di proprietà dello Studio Moretti Caselli di Perugia

Omnia venenum sunt: nec sine veneno quicquam existit. Dosis sola facit. ut venenum non fit.

Conclusions