FI59805B - FOER FAR INSPECTION FOR OIL FITTING OEVERDRAG AV TRANSPARENTA TVAOKOMPONENT-OEVERDRAGSMEDEL OCH I FOERFARANDET ANVAENDBARA OEVERDRAGSMEDEL - Google Patents

Description

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(41) Made public - Bllvlc offantllg 17.06.7U

National Board of Patents and Registration NlhtMkslp ™ |. moonless date-

Patent and registration authorities Ansökan utlagd och utl.akriftan publkarad 30.06.01 (32) (33) (31) Pyydetty atuoikaus — Begird prloriut l6.12.72

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 226165Π.2 Proof-Styrkt (71) BASF Farben + Fasern Aktiengesellschaft, Esplanade 36a, 2000 Hamburg 36,

Federal Republic of Germany-Förbundsrepubliken Tyskland (nE) (72) Bernard Kostevc, Munster, Federal Republic of Germany-Förbundsrepubliken Tysk-land (DE) (7H) Oy Kolster Ab (5H) Method framställning av ogenomskinliga overdrag av transparenta tväkomponent-overdragsmedel och i förfarandet användbara överdragsmedel

The invention relates to a process for the preparation of opaque coatings having a high opacity for acid-curable condensation resins Derustable transparent two-component coating compositions consisting of: A. organic solvents, B. organic solvents, and alkyd resin plasticizers, D. ordinary additives, E. acidic or acid-releasing hardeners.

Two-component end coatings are known which are based on 2,580,805 acid-curable condensation resins containing aminoplastic resins, plasticizers, solvents, acid-cured and possibly pigments, fillers and additives. They are used in industry as coating and coating materials. Depending on the type and amount of materials used, these two-component varnishes provide coatings with a wide range of technological properties. For example, the gloss, elasticity, hardness, impact strength, weather resistance, etc. of the coatings can be affected by appropriately selecting the components and hardener as well as the drying method.

In this way, transparent coatings are obtained from non-pigmented, transparent two-component varnishes and colored, opaque, opaque coatings from pigmented two-component varnishes.

Not all pigments are suitable for pigmentation of two-component varnishes that are cured with acidic compounds. In addition, special equipment, machines and considerable time are required to modify the pigments inside the varnish. Until now, it has not yet been possible to obtain opaque coatings covering non-pigmented two-component lacquers in a simple manner.

The present invention is based on an attempt to find a method by which opaque, opaque coatings or cover layers can be made from transparent, pigment-free two-component coating materials of said type.

By "two-component coating agent 11a" is meant below all solutions of acid-curable condensation resins which can be cured by means of an acidic or acid-releasing hardener. These components are only mixed together just before use in an accurately weighed or measured ratio.

The method according to the invention can be used for the production of coatings on wood, woodworking materials, cardboard, paper, artificial materials, extruded products, metals, masonry, concrete, cement, and very generally on any substrate. The surfaces to be coated may be untreated, although they may be pre-treated by pickling, smoothing or priming.

The method according to the invention is characterized in that a coating agent, 59805, containing components B and C in a ratio of 1: 3 to 1: 0.5, preferably 1: 2.3 to 1: 0.8, is applied to the substrate to be coated, and further comprises: F. not more than 60% by weight, preferably 5 to 50% by weight, based on the total weight of components B and C, of saturated aliphatic hydrocarbons at 20 ° C with a boiling point above 160 ° C and an ether evaporation number of 800 to 1,500 as defined in DIN 53 170 , and optionally, G. not more than 30% by weight, preferably 5-20% by weight, based on the total weight of components B and C, of inorganic and / or organic fillers with low opacity, optionally H. not more than 40% by weight of component C is replaced by styrene-allyl copolymers soluble in component A and compatible with B and C.

The invention furthermore relates to acid-curable condensation resins based on two-component organic solvents consisting of: A. organic solvents, and alkyd resin plasticizers compatible with amino plastics B, D. ordinary additives, E. acidic or acid-releasing hardeners, the coating agents being characterized in that they contain components B and C in a ratio of 1: 3 to 1: 0.5, preferably 1: 2.3 to 1: 0.8, and further comprising, F. not more than 60% by weight, preferably 5 to 50% by weight, based on the total weight of components B and C, of saturated aliphatic hydrocarbons having a boiling point above 160 ° C at 20 ° C and Ether 53 defined according to DIN 53 170 a boiling point of 800 to 1,500, and optionally G. not more than 30% by weight, preferably 5 to 20% by weight, based on the total weight of components B and C, of inorganic and / or organic fillers having a low opacity, optionally 4,5805 H. Up to 40% by weight of component C has been replaced by styrene-allyl copolymers soluble in component A and compatible with B and C.

It was surprising and not foreseeable that the process according to the invention gives coatings based on transparent 2-component coating materials based on acid-curable condensation resins which are no longer translucent or transparent and which have a high opacity. The coatings are uniform and white throughout their layer thickness. It was surprising that the degree of whiteness of the opaque coatings obtained by the process of the invention was higher than the degree of whiteness obtained with known two-component coating agents based on acid-curable condensation resins using titanium dioxide white pigments. In addition to the known coatings pigmented with white pigments, the coatings obtained according to the invention also have other advantageous technological properties which have hitherto not been possible with the use of pigmented or non-pigmented two-component coating materials.

Thus, by using the coating materials according to the invention, it is now possible to achieve a property called 100% ring strength. This is understood to mean the property of a white coating that, when in sliding contact with metals, no visible sign of discoloration remains on the film. In the presence of opaque pigments, grayish insignificant streaks are formed during the ring test, which can no longer be removed at all or only with great difficulty.

Opaque coating coatings made of two-component coating materials based on acid-curable condensation resins are obtained by selecting the ratios between components B, C, F, G and H as specified. Only by maintaining these relationships with the private components does this surprising result occur.

In the context of the present invention, the expression "acid-curable condensation resins" preferably means amino-plastics which can be curable by means of acids or acid-donating compounds. Amino-plastics are condensation products obtained by the reaction of a compound having at least two amino-5S805 groups, such as urea, thiourea, dicyandiamide, melamine, guanamine or benzoguanamine and / or their derivatives, with an aldehyde or an aldehyde-donating compound, e.g. with formaldehyde, benzaldehyde or paraformaldehyde. Extensive literature is summarized, for example, in Kunststoff-Handbuck Part X, Duroplaste, R. Vieweg, and E. Becker, 1968, Carl Hanser Verlag MUnchen. The condensation products of these compounds are usually prepared from a neutral or weakly alkaline reaction mixture and are generally etherified with a trivalent alcohol. Suitable alcohols for this purpose are: propanol, methanol, ethanol, isopropanol, butanol and iso-butanol. Sometimes polyhydric alcohols, such as ethylene glycol, can also be used.

Plasticizers within the meaning of this invention are preferably polyester or alkyd resins. There is a wide range of suitable alkyd or polyester resins. Lacquer technical properties are crucial in the selection of alkyd resins.

Alkyd resins are known to be polycondensation products of polyalcohols on the one hand and polycarboxylic acids on the other. The polyalcohols used are above all glycerol, pentaerythritol, trimethylolioropane, but also numerous other compounds. The polycarboxylic acids used are preferably phthalic acid or its anhydride. Isophthalic acid and terephthalic acid, maleic acid, adipic acid, succinic acid as well as derivatives thereof can also be used, in addition to citric acid, aconitic acid and several such compounds. Alkyd resins are most often modified by the addition of saturated or unsaturated fatty acids, such as linseed oil, soybean oil, castor oil, castor oil oil, coconut oil, coconut oil, etc. In this way, numerous possible alkyd resins are prepared. Fatty acid-modified, medium-oil alkyd resins are preferably suitable for the coatings according to the invention.

Depending on the desired technological properties of the coating, plasticizers can also be used alone or in combination with alkyd resins, such as phthalic acid esters, phosphoric acid esters, castor oil, epoxidized 6,580,805 oils, low molecular weight epoxy resins and other. Plasticizers should be miscible with amino resins (component B) and soluble in organic solvents (component A). As the organic solvents (component A), all those in which the amino resins (component B) and plasticizers (component C) are soluble can be used, whereby it is also possible to use a certain amount of non-solubilizing agents. Thus, for example, polar solvents such as alcohols, esters, glycol ethers, glycol ether acetates are suitable, but also apolar aromatic substances such as toluene, xylene or benzene or aliphatic hydrocarbons. They can be used alone or in mixtures.

The coatings according to the invention are cured by means of acidic or acid-donating compounds. Suitable for this purpose are strong inorganic acids, such as hydrochloric acid, sulfuric acid, phosphoric acid, etc., or organic compounds which, in the presence of water or alcohols, cleave organic acids, such as sulfonic acids, e.g. toluenesulfonic acid, or benzenesulfonyl chloride. Weaker organic acids such as oxalic acid, phthalic acid, adipic acid and maleic acid can also be used. A combination of the above curing agents is also possible. Suitable solvents for these hardeners are alcohols, such as methanol, ethanol or butanol, optionally in admixture with glycol ethers, etc. Depending on the degree of acidity of the hardener component and the amount of amino resin, hardeners are added to 0.5 to 10% by weight of the coating agent according to the invention.

Up to 40% by weight of component C may optionally be replaced by a styrene-allyl alcohol copolymer (component H).

These include copolymers of a monomeric allyl alcohol with styrene, wherein the styrene units of the copolymer are derived from styrene itself, C 1-4 alkylstyrenes, ring-substituted alkylalcohols or allyl alcohols, allyl alcohols and haloalkylstyrenes, haloalkylstyrenes, haloalkylstyrenes, haloalkylstyrenes; The molecular weight is between 1,000 and 3,000. The preparation of such styrene-allyl alcohol copolymers is described, for example, in British Patent Publication 844,406.

59805 Coatings may contain as component G ordinary fillers with low opacity. These are understood to mean fines whose refractive index does not differ substantially from the refractive index of a two-component coating solution, which excipients may be, for example, silica, barium sulphate, talc, mica, dolomite, kaolin, quartz powder, rock powder, glass powder, etc. 30% by weight based on the total weight of components B and C. Fibrous microsubstrates consisting of organic and / or inorganic materials such as polyamide, triacetate, asbestos, etc., alone or in combination with the above-mentioned fillers, can also be used. In a preferred embodiment, 5-20% by weight of component G is used in the coating agent.

As aliphatic hydrocarbons (component F), all saturated aliphatic hydrocarbons obtained from extraction, alkylation and distillation processes can be used, which contain n-paraffins as the main constituents and have a boiling point above 160 ° C, preferably 220-350 ° C and an ether evaporation number according to DIN 53 170 is between 800 and 1 500. The proportions of isoparaffins and naphthenic substances must not exceed 2 to 4% and the aromatic and unsaturated compounds must not exceed 0,5%.

Coating agents may contain conventional additives such as thixotropic agents, fluxes, synthetic resins other than components B and C, such as nitrocellulose or cellulose acetobutyrate in minor amounts.

The preparation of the coating material according to the invention is carried out according to customary methods in suitable dispersing devices, such as agitating devices, mixing devices, ball mills, sand mills, rolling mills, dispersers, etc.

No special measures are required to prepare the coating materials according to the invention. Coating agents can be prepared simply, for example, by adding amino resins and alkyd resins or other plasticizers simply by stirring in solvents. Finally, component G can be dispersed in the solution. Component E is only mixed in shortly before use.

The two-component coating materials can be applied in the lacquer industry by conventional application methods, such as casting, spraying or roll using wood, woodworking materials, artificial materials, glass, cardboard, paper and metal. The working materials to be coated may possibly be pretreated or may already have a primer or a smoothing layer.

Curing of the applied coatings is achieved by means of the curing component E. Curing takes place at room temperature. The curing rate depends on the type of amino resin and the type and concentration of the acidic curing component used. Curing can be accelerated by the use of heat.

The coatings obtained according to the method of the invention are opaque and white and have a high opacity. When a soluble dye or transparent pigment is added to the transparent coating agent, a colored coating is obtained. By appropriately selecting a dye, any arbitrary color shade other than white can then be obtained.

The application rate of the coating agent per unit area varies depending on the substrate used and the intended use. The thickness of the coating is usually 50-400 μm. Thinner or thicker coatings can also be made. When using very thin coating layers, the opacity of the opaque coating is, of course, lower than in the case of thicker layers.

The following examples illustrate the invention. The parts mentioned are parts by weight and the percentages given are percentages by weight. Example 1

The coating material is prepared from the following ingredients: 25 parts of urea-formaldehyde resin etherified with butanol (60% solution in butanol), 25 parts of medium oils, soybean oil-modified alkyd resin (60% in xylene), 50% allyl alcohol-50% allyl alcohol in ethyl acetate, 15 parts of a saturated aliphatic hydrocarbon having a boiling point of 244 to 320 ° C and an ether evaporation number of 1,000.

5 parts of adipic acid butanediol ester (plasticizer) 2 parts of a 5% solution of silica oil in toluene.

To this mixture is added 25 parts of a 25% ethanol solution of toluenesulfonic acid. The coating material is applied to the wood board so much that the thickness of the film becomes 300 Aim. The coating is allowed to evaporate for 59.5805 minutes and treated for 2.5 minutes in a convection oven at 40 ° C.

It is then dried for 15 minutes at 100 ° C. This results in a completely opaque coating with a uniform white color, although the coating composition does not contain any fillers or pigments.

Example 2

The coating material is prepared from the following ingredients: 15 parts solvent xylene / ethylene acetate (2: 1) mixture, 17 parts butanol etherified melamine-formaldehyde resin, 60% in butanol, 47 parts soybean oil fatty acid based medium oils, 60% alkyd resins 20 parts of silica gel, 1 part of a 10% toluene solution of silicone oil.

10 parts of a 25% ethanol solution of toluenesulfonic acid are added to the mixture, and the coating is prepared in the same manner as in Example 1. After drying, a uniform white coating with a high coverage is obtained.

Example 3

The coating material is prepared from the following ingredients: 15 parts of urea-formaldehyde resin etherified with butanol, 60% in butanol, 44 parts of a medium oil based on cottonseed oil, an alkyd resin of 180%, 50% in xylene, 18 parts of silica gel, 5 parts of silica gel, 5 parts of silica gel, , ether evaporation number 1,000, 1 part of a 10% toluene solution of silicone oil, 4 parts of adipic acid butanediol ester (plasticizer), 13 parts of xylene.

10 parts of a 25% ethanol solution of toluenesulfonic acid are added to the mixture and the coating is prepared in the same manner as in Example 1. After drying, a uniform white coating with a high opacity is obtained.

Example 4 (comparative example):

The following materials are used to prepare a coating material known from the prior art, in which the proportions of the components are not within the scope of the invention, 42 parts of carbanol di-formaldehyde resin etherified with butanol (60% solution in butanol), 25 parts of medium oils, peanut oil modified, xylene, 8 parts allyl alcohol-styrene copolymer, 50% ethyl acetate, 10 parts silica gel, 15 parts solvent xylene / ethyl acetate (2: 1). 15 parts of a 10% toluenesulfonic acid solution are added to the mixture and the coating is prepared in the same manner as in Example 1.

The coating obtained after drying is transparent and the structure of the chipboard is visible.

Example 5 (comparative example):

The mixture described in Example 4 is ground with 4% titanium dioxide using a 3-roll roller chair. With the help of a cast coating machine, the coating applied to the chipboard base layer in a thickness of 300 .mu.m is uniformly white.

Example 6

In order to determine the technical advance achieved by the invention compared to Comparative Example 5, 4% of titanium dioxide is also ground in the coating material described in Example 2. A 300 thick coating is prepared and cured as described in Example 2. The whiteness is higher than the whiteness of the coating of the same thickness obtained according to Example 5. In order to achieve the same degree of whiteness as in Example 6, the titanium dioxide content in Example 5 must be raised from 4% to 16-20%.

Example 7

0.5 part of Zaponechtbraun dye is added to the coating composition described in Example 2.

The coating prepared as described in Example 1 is uniformly brown and has excellent opacity.

Claims (4)

11 59805 A process for the preparation of opaque coatings having a high opacity of transparent two-component coatings based on acid-curable condensation resins, consisting of: A. organic solvents, B. solvents with organic solvents A and soluble amino acids A, C. organic solvents compatible alkyd resin plasticizers, D. ordinary additives, E. acidic or acid-releasing hardeners, characterized in that a coating material containing components B and C in a ratio of 1: 3 to 1: 0.5, preferably 1: 2, is applied to the substrate to be coated, 3 to 1: 0.8, and in addition F. contains not more than 60% by weight, preferably 5 to 50% by weight, based on the total weight of components B and C, of saturated aliphatic hydrocarbons having a boiling point above 160 ° C at 20 ° C and an ether evaporation number of 800 to 1,500, determined according to DIN 53 170, and possibly, G. maximum 30% by weight, preferably 5-20% by weight, based on the total weight of components B and C, of inorganic and / or organic fillers with low opacity, optionally H. up to 40% by weight of component C is replaced by those soluble in component A and B: with C and styrene-allyl copolymers. A method according to claim 1, characterized in that the coating agent further contains colorants or translucent pigments as coloring agents. Acid-curable condensation resin-based two-component coatings for use in the production of opaque coatings with good opacity in the process according to claim 1, consisting of: A. organic solvents, B. amino solvents and soluble amino acids, alkyd resin plasticizers, ™ S9SO5 D. ordinary additives, E. acidic or acid-releasing hardeners, characterized in that they contain components B and C in a ratio of 1: 3 to 1: 0.5, preferably 1: 2.3 to 1: 0.8 , and further comprising, F. up to 60% by weight, preferably from 5 to 50% by weight, based on the total weight of components B and C, of saturated aliphatic hydrocarbons at 20 ° C with a boiling point above 160 ° C and defined according to DIN 53 170 ether evaporation number 800-1,500, and optionally, G. up to 30% by weight, preferably 5-2 0% by weight based on the total weight of components B and C, inorganic and / or organic fillers with low opacity, optionally, H. up to 4-0% by weight of component C has been replaced by components soluble in component A and B and C: with styrene-allyl copolymers. Coating agent according to Claim 3, characterized in that it further contains a colorant or a translucent pigment as a colorant. 13 59805