HU181533B - Process for preparing paints for artists on the basis of silicone rubber - Google Patents

Description

(54) Process for the production of silicone rubber based artist paints

2

The present invention relates to a process for producing an artist's paint.

The artist's paints of the invention contain polymers composed of dimethylpolysiloxane-diol units.

The process according to the invention is carried out by admixing 34 to 70% by weight of a pigment, previously ground with hexamethyldisilazane or dimethyl, to a silicone rubber binder having a silane diol moiety having a molecular weight of 4,000 to 80,000 by weight. dichlorosilane and methyl trichlorosilane in a 10% w / w solution of solvent, then the mass is dried and milled, optionally with 1-5% by weight of a known crosslinking catalyst and optionally 0-35% by weight of a filler. or a lubricant.

By incorporating pigments or solvents pre-treated into the polysiloxane binder, paint pastes with a consistency similar to those of classic oil paints can be obtained. The new plastic-based paints can be used to coat various surfaces (fiberglass, linen, or, after proper preparation, glass, wood, wood fiber and concrete) to create artwork.

The dyes used in painting for centuries are made from plant-based drying oils (linseed oil), suitable pigments, additives (mastix) and solvents according to centuries-old formulations. [Kiplik: Maltechnik; Heuschel, Berlin (1954)].

These well known organic paints have many advantages and disadvantages. Organic raw materials over time due to oxidation processes due to heat, light and other influences, as a result of destructive processes, the dyed layer is crushed, cracked and peeled off the base layer or the dye layer is discolored. [Schramm: Historische Malmaterialen, Dresden (1971)] In particular, linen-based paintings are very sensitive to heat and humidity, and may suffer irreparable damage if stored improperly. Restoring them and storing them in the right conditions nowadays causes a lot of problems.

In order to overcome these problems, the present invention provides silicone-based inks that are resistant to the above effects. As binders for paints, they contain cold-vulcanizing silicone rubbers of different viscosities; and pigments are mineral or synthetic powder inks (eg TiO ₂ , Fe ₂ O ₃ , Cr ₂ O ₃ , CdS, CoO.ZnO, etc.).

Cold-vulcanizing silicone rubber binder has the following characteristics.

From a chemical point of view, methyl or. methylphenyl, or. methyl vinyl polysiloxanes having reactive groups at the end of the polysiloxane chain can be used.

The degree of polymerisation of the polysiloxane species used may vary from 100 to 1000, with a viscosity of from 1000 to 500,000 mPa.s (optimum value from 2000 to 100,000 mPa.s).

The following types of cold vulcanizing silicone rubbers are suitable for the above purposes.

One-component silicone rubbers which are acyloxy, alkoxy, and acryloxy. alkylamino etc. groups which are hydrolysable to air humidity catalysts.

Two-component cold vulcanizing silicone rubbers181533 which can be used with a catalyst selected for the crosslinking of any cold vulcanizing rubbers selected for the desired setting time.

Two-component cold-vulcanising rubbers, one component of which is methyl vinyl polysiloxane and the other component is methyl hydrogen polysiloxane, which can be crosslinked in the presence of a suitable catalyst (e.g., H ₂ PtCl _e ).

Active fillers consisting primarily of untreated or surface-treated aerosols (white carbon black) with a surface area of 100-400 m ² / g. These may range from 0 to 35% by weight.

Inactive fillers include quartz flour, cellite, diatomaceous earth, kaolin, aluminum hydrate. They are optimally 1-5%.

The silicone oil additive may be a methyl or methylphenyl silicone oil having a viscosity of 10-1000 m Pa.s. Optimal viscosity 10-50 m Pa.s.

Suitable Pigments are the well-known powder inks, mostly of inorganic origin, which are heat-resistant (at a temperature of at least 100-500 ° C), UV-resistant, light-resistant and storm-resistant, as well as airborne contaminants such as CO, CO ₂ , H ₂ S, SO ₂ , NO ₂ , etc. do not react.

The paint paste is soluble in various non-polar organic solvents [benzene, toluene, chlorinated hydrocarbons (carbon tetrachloride, etc.)]. The amount of solvent may vary from 1 to 50% by weight. The most suitable solvent is turpentine.

Cold-vulcanizing silicone rubbers are used in studio and industrial applications. can be applied to textiles, wood, glass, metal and other surfaces that have been properly pre-treated outdoors.

The staining procedure is as follows.

Apply a mixture of a white pigment (TiO ₂ ) dye paste diluent, untreated or pre-treated with a silicone hydrophobising agent, with turpentine, diluted with a brush, spatula or possibly a lubricant, evenly covering the canvas. After lubrication, the paint is blown evenly, twice successively, with the catalyst to secure the base coat.

Silicone paints of different colors according to the invention can be applied to the pre-treated surface, and after application, a catalyst is uniformly sprayed onto this layer. Depending on the catalyst chosen, the setting time can be adjusted as desired.

The dye application process may also be carried out by mixing the crosslinking catalyst into a dye containing silicone rubber prior to dyeing, which is diluted to its proper consistency during dyeing, whereby the dye is fixed by the action of the catalyst contained therein. This latter process has the disadvantage that the paint mixed with the crosslinking catalyst can only be used within the setting time, so that the preparation of the paint has to be completed within a certain time (which, however, can be varied within wide limits). After that, you can only apply a new coat of paint to the resulting image.

However, the latter can also be characterized by a one-component version of silicone paints. The advantage of the two-component system, however, is that the paint paste does not need to be mixed with the crosslinking catalyst because it is already included in the paste. When the ink is printed, the catalyst in it exerts a curing effect on contact with the humidity of the air, and cures for approx. It reaches its final consistency within 24 hours. As a catalyst, a mixture of tetraalkoxy or alkyl trialkoxysilane and dialkyldiacyloxy tin is used for the two-component system. These include, for example, a mixture of tetraethoxysilane and dibutyl dilaurate tin.

For the one-component system, methyl triacetoxysilane, methyl trialkylaminosilanes are used. Boric acid esters and tetraalkoxy titanium compounds useful as catalysts are also mentioned.

The use of the silicone rubber based paint prepared as described above provides the following benefits:

(a) when using two-component paint, the consistency of the paint paste is constant, does not air-dry and does not change with time;

(b) the paint paste can be diluted with solvents to the extent required by the painting technology. The material can be applied as desired during the dyeing process in both thin and thick layers;

'(c) details of the image may be recorded after treatment with the catalyst. The curing time or time. the setting time at room temperature depends only on the amount and quality of the catalyst and can be adjusted from a few minutes to 24 hours.

Painting made with silicone paints has the following advantages:

(a) Resistant to chemical attack and environmental damage (eg O ₂ , NO ₂ , H ₂ S, NH ₃ acid or alkaline fumes and gases).

(b) water vapor and water do not damage:

(c) due to its hydrophobic (water repellent) surface, the hydrophilic powder does not adhere to it and is thus not soiled.

(d) resistant to photochemical effects because the siloxane bond does not absorb light quanta with a wavelength greater than 180 nm;

e) the applied layer is heat and cold resistant. Glass transition point - no change between 60 and +180 'C. thus, it can be demonstrated that it can be stored indefinitely in normal conditions (-25 to 50 'C) provided that the powder inks used do not suffer damage under these conditions;

(f) on the basis of the above characteristics, the storage of works of art does not require any special restrictions (air conditioning, etc.);

(g) silicone paint for use in textiles, paper, cement, glass, porcelain or china. adhesive can be applied to ceramic surfaces, after proper pre-treatment. The next layer can be applied permanently to the fixed layer and adheres well, allowing the image to be further developed and varied.

9) According to the invention, paint pastes can be prepared by methods known in the paint and lacquer industry.

Production of silicone paints.

Preparation of two-component pastes:

Add the active and inactive fillers and the required powder pigments to the base material on a roller blade or in a Z-arm mixer or ball mill to obtain a completely homogeneous, well-spread paint paste. The finished paint pastes are sprayed or disassembled into jars.

A series of necessary catalysts, which are separated from each other by the length of the cure time or by they may differ in the mechanism of binding, and may be marketed in aerosol design and filled in bottles.

Preparation of one-component pastes:

In the preparation of one-component pastes, suitable catalysts are used in inert gas or air to remove air. vacuum mixing with the other components and then spraying.

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Example 1

Preparation of a two-component paint paste series la) Preparation of non-additive paint paste

Component A (pigment - (- binder)

Measurement: dimethyl polysiloxane-α-diol having a viscosity of 10,000 mPa.s, to which the pigment materials indicated in the table are admixed when preparing base coatings of different colors.

The name of the saloon paint Composition of pigment The optimum amount of pigment is sr / 100 sr rubber The finished paint paste is consistently necessary for the formation of a ci solvent sr / 100 sr rubber Titanium is white TiO ₂ 200 60 Cobalt Blue Nickel CoO, SiO ₂ 167 33 Titanium Yellow Chrome Oxide Green - 263 16 matte finish Cr ₂ O ₃ 333 40 Cadmium Red Cadmium CdS + CdSe 200 40 orange CdS 143 123 Black nail anthraquinone 250 80 Krapplakk derivatives 80 64

For better adhesion of pigment materials and base rubbers, the surface of the pigment powders must be pretreated with silicones. Pretreatment of pigment powders with dimethyldichloride and / or methylene chloride. methyl trichlorosilane in 10% solution of benzene, toluene or carbon tetrachloride or 10% solution of hexamethyldisilazane in benzene.

The previously pigmented, dried and, if necessary, shredded pigment is rolled into a silicone rubber base.

For the thick mass thus obtained, use the appropriate amounts of solvent (eg turpentine), also indicated in the table, in suitable equipment (eg Z-lever mixer) to obtain the optimum consistency of each paint paste. Stirring is continued until the paste is completely homogeneous.

The pastes thus prepared are sprayed for good handling.

Component B (fastener)

Catalyst, for spray application in aerosol form. Catalysts include all types of catalysts which are capable of curing two-component cold vulcanizing silicone rubbers with a cure time of 1 to 10 hours. The catalyst used is 67-33% by weight of a mixture of tetretoxysilane and dibutyl dilaurate Sn, under the trade name "Silorka-K-1" lb) Development of a two-component filler paste containing fillers.

Component A

calibration:

100 sr dimethyl-pousoxane-α-ω-diol viscosity 35-40,000 mPa.s sr Cellite (inactive SiO ₂ ) sr Aerosil (Degussa R 972) sr Cadmium orange pigment (CdS)

The hydrophobizing agent is a 10% solution of hexamethyldisilazane in benzene to impregnate the pigment, then the mass is dried at 80 ° C and ground, or

Component A: (Starting from a low viscosity rubber base)

calibration:

100 sr dimethyl polysiloxane-α, ω-diol sr with a viscosity of 20 to 25 000 mPa.s, sr quartz flour sr cadmium orange pigment (CdS)

For the hydrophobization of the pigment, a CCl ₄ solution of a 1: 1 molar mixture of dimethyl dichlorosilane and methyl trichlorosilane was used.

Mixtures prepared according to the above composition are homogenized on a rolling mill. If necessary, adjust the consistency with a solvent (e.g. turpentine). After homogenization, the product is incubated.

When used, the paint can be diluted with a solvent (eg turpentine) in a brush palette.

Component B: Catalyst as in Example 1a).

le) Preparation of a two-component filler paste containing filler.

Component A:

calibration:

sr 13,000 mPa.s viscosity dimethyl-polysiloxane-α-ωdiol, sr Aerosil (Wacker HDK-H 2000) sr Hexamethyldisilazane (Hydrophobising agent) sr turpentine (solvent) sr chromium oxide green pigment

The mixture of the given composition is homogenized on a rolling mill. After homogenization, the product is sprayed.

When used, the paint can be further diluted as desired with the paintbrush, palette and solvent (turpentine).

Component B: Catalyst according to example la).

Example 2

Production of one-component paint paste

The pastes of the formulations described in Examples 1a), lb) and le) may also be prepared in a one-component embodiment using a non-acidic catalyst type with the exclusion of air and moisture. Non-acidic catalysts which may be used include boronic esters, tetraalkoxy titanium derivatives, or silylamines

calibration:

sr le) Chromium oxide green matt pigment paste with composition as described in Example sr sr Boric acid triisopropyl ester (catalyst)

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In a sealed device with a homogenizing mixer, in an inert gas atmosphere, the completely anhydrous dye paste is homogenized and sprayed using a tube dispenser connected to the device.

When using single-component dyes, care should be taken that when the air is humidified, the curing of the dye starts depending on the amount and quality of the catalyst. Thus, the use of one-component pastes is limited in time.

Example 3

Preparation of surfaces to be painted before applying silicone paint

Silicone rubber-based paints can be used to paint any surface to which the cured silicone rubber binder paint adheres well: unfinished linen, fiberglass, glass, concrete, layered surfaces, wood, brass or lacquer. aluminum surfaces.

In order to increase the adhesion of the silicone rubber based paint to the substrate, it is advisable to pre-treat the particular surface to be painted.

Pretreatment can be accomplished by any process known in the art of silicone chemistry that utilizes paper or paper. in case of textiles it provides a water-repellent finish, or glass, fiberglass, concrete or. suitable for hydrophobization of stacked surfaces.

3a) Preparation of linen cloth

Unfinished linen is stretched onto a wooden frame and a silicone rubber titanium white paint (Component A: Example 1a) is applied to the base so stretched with a brush. Smooth the paint layer with a spatula. The white paint layer thus applied is uniformly blown off in a thin layer according to the aerosolized catalyst (Component B, Example 1a). (Suitable catalyst is Szilozka K-1, manufactured by the Fine Chemicals Co-operative.) After 2 hours, the applied primer coat can be painted with silicone paints after drying.

3b) Preparation of wood base

To make the painting, we apply a thin coat of silicone varnish (Silicone varnish 1401 Fine Chemicals Cooperative) in a thin layer with a perfectly smooth surface with a spray gun. The applied varnish is spray-dried for 24 hours either in air at room temperature or after evaporation of the solvent (about 1 hour) with warm air (150 ° C).

It is now possible to apply a layer of silicone rubber on the dried lacquer.

Example 4

Application and crosslinking of two-component silicone rubber binder paints.

4a) Making a painting on linen

For linen prepared according to Example 3a), silicone paints may be applied by brush, lubrication, spatulation.

The finished, dyed paint is aerosolized with a catalyst, such as Silorka K-1 catalyst, which must be blown evenly in a thin layer so that the work can be fixed.

If the surface coated with the catalyst remains slightly adherent after 12 to 24 hours, the application shall be repeated.

After curing, the paint dries. After that, the painting can only be changed by repainting and fixing.

4b) Another method of fixing and fixing the paint: the painter mixes the silicone paint in the palette with 10 sufficient amounts of the catalyst (The amount of the catalyst: minimum 1% by weight of the paint, maximum 10% by weight of the paint, preferably 4-5% of).

Suitable catalysts are all silicone rubber crosslinking catalysts which provide a pot life of more than 1 hour (the time during which the mixture retains its original consistency) and a curing time of at least 6 hours (the time of total crosslinking).

The duration of crosslinking can be controlled depending on the type and amount of catalyst used. (The use of a Gyor20 removable catalyst limits the usefulness of the paint mixed with the catalyst for a limited time.

Example 5 25

Thermoanalytical tests

The thermal stability of the pigment materials used in the preparation of the dyes, the crosslinked polymer having a viscosity of 300000mPas and the filler and the dopant used in the preparation of the dyes, and the dye made with the TiO ₂ pigment material according to Example 1 were tested. Measurements were made on a MOM G-425. The results obtained from the evaluation of the thermal analysis curves are summarized in Table I. 35 The good heat resistance of the metal oxide pigments used is clearly reflected in the table. Vulcanized silicone rubber without filler and additive has a noticeable decomposition above 200 ° C and more than 10% by weight change above 350 ° C. The sample containing the titanium-white pigment exhibits only 2% 40 weight changes up to 200 ° C, but even at 350 ° C it has only 5.1% weight loss and this value remains below 10% at 400 ° C (6 , 5%). Thus, silicone paints made with refractory pigments further improve the thermal properties of high temperature (150-200 ° C) silicone rubber binder.

We also conducted a series of experiments to determine how much more heat-resistant silicone paints and coatings of the same quality can be applied to linen. heat resistance of oil paints. of pure glass tissue and also the heat resistance of fiberglass fabrics pretreated with silicon rubber titanium white system. Our test results are summarized in Figure 1, showing the weight loss of each sample as a function of temperature change. The meaning of the symbols in Figure 1 is as follows:

- · - · - · - · Linen - Impregnated linen ——— Oil-titanium oil-on-white linen

X-X-X-H Silicone Rubber Titanium White Dye Impregnated Linen ········ Silicone Rubber Titanium White Dye Fiberglass * · ** - «** Fiberglass

It is clear from Figure 1 that the snow resistance of silicone rubber-coated linen is improved compared to untreated linen 65. The table also shows that

-4181533 is the most suitable base for paintings made from silicone rubber-based paints, which enables the production of works of art that can be stored indefinitely even in places exposed to heat fluctuations.

In a third series of experiments, a silicone rubber-based paint or lacquer-dyed base can be used. the thermal properties of oil paint samples were compared. (Table II). The data in the table show that the weight loss of samples coated with silicone rubber inks is in all cases smaller than that of samples coated with oil paints. At about 150 ° C, the thermal properties of heat-sensitive linen determine the thermal resistance of the paint-linen system.

Other tests

In addition, the chemical resistance (5% aqueous ultra solution, 104 hours, room temperature) of oil paint treated linen samples and 5 paint treated linen samples based on silicone rubber were compared.

The results of the study showed that such an effect was not tolerated by the oil paint treated samples (the oil paint coating disappeared from the canvas in 104 hours), while the silicone ka10 puncture paint treated samples did not show any damage, even with accurate color measurement methods.

Samples treated with silicone rubber based paint subjected to UV radiation (443 hours) sustained did not show significant tonal changes, whereas oil-treated samples undergo a tonal change.

Table I

Thermal analysis of pigments used in silicone paints and silicone rubber base

Pigment's name composition 50 C 100'C 150 C 200'C 250 ° C 300'C 350 ° C Weight Loss% Titanium white TiO ₂ 0.1 0.2 0.4 0.4 0.5 0.5 0.6 Cobalt blue CoO.SiOj 0.1 0.4 0.5 0.6 0.7 0.8 03) Nickel titanium yellow - 0.1 0.2 0.3 0.45 0.5 0.55 0.6 Chrome oxide green matt Cr ₂ O ₃ 0.05 0.15 0.2 0.3 0.3 0.35 0.4 Cadmium red CdS and CdSe + 0.1 0.2 0.3 0.3 0.4 0.5 0.55 Cadmium orange CdS 0.05 0.1 0.2 0.2 0.2 0.25 0.25 Black soot nail anthraquinone 0.35 2.15 3.1 3.7 4.1 4.5 5.3 Krapplakk derivatives 0.45 4.55 10.3 16.0 - - - Pigment and additive-free, vulcanized silicone rubber la) silicone paint according to example la) 0.1 0.2 0.3 0.8 1.8 3.3 6.5 (Vulcanized) - 0.1 0.3 0.8 1.4 2.15 3.15

II. spreadsheet

Thermal examination of samples made with silicone rubber based paint or oil paint

The name of the paint Percentage of material discharged at various temperatures 50 C 100 C 150 ° C 200'C 250 'C 300'C la) the following pigments having the composition according to example la titanium white cobalt blue nickel titanium yellow chromium oxide green matt cadmium red cadmium orange black drape 0.1 0.15 0.15 0.2 0.2 0.3 0.25 0.3 1.0 1.0 1.2 1.5 1.2 1.6 1.5 1.9 2.0 2.15 2.3 2.7 2.5 3.1 3.2 3.8 2.9 3.3 3.4 3.9 4.0 5.0 5.3 5.5 5.5 6.0 6.3 6.7 7.1 8.8 9.8 8.9 Paint containing oil paint and the following pigments: Titanium white chromium oxide green matt black drape 0.3 0.3 0.4 0.5 1.7 1.7 2.3 2.5 2.7 2.7 3.6 3.6 4.0 4.0 5.0 5.2 7.0 7.0 8.2 9.0

In each sample, the amount of material leaked is above 10%.

Claims (2)

CLAIMS 1. A process for producing artist dyes comprising mixing 34-70% by weight of a pigment, previously hexamethyldisilazane or dimethyldichloride, with 20-42% by weight of a silicone rubber binder having a molecular weight of 4000-80000 containing silanediol units. hydrophobized with a 10% solution of a mixture of silane and methyl trichlorosilane in solvent, dried and milled, then optionally mixed with 1-5% by weight of a known crosslinking catalyst and optionally 0-35% by weight of a filler or 5 lubricants. 2. The process of claim 1 wherein the hydrophobizing agent is hexamethyldisilazane.