SE192092C1 - - Google Patents

Description

Inventors: F. Schauder and H. Pohlemann Priority request 13: Customs and 21 December 1961 (Federal Republic of Germany) The binder systems consist of mixtures, the essential components of which consist of a solid resin-forming substance (binder) and solvents for this purpose. Furthermore, the varnishes do not contain any different additives, such as pigments, plasticizers, light preservatives and curing catalysts.

Aqueous binder systems consist of those which, as solvents, contain a volatile component consisting solely of water or predominantly of water. They have the advantage that they are non-flammable and usually non-toxic and inexpensive.

For binder systems of this type, especially for the production of fire-varnishes, aqueous solutions have already been proposed, which as binders contain both copolymers of α4-unsaturated carboxylic acids and styrene or vinyl esters and also urea-formaldehyde condensates. For the binder systems, aqueous solutions have also been prepared, which as binder contain partially desalinated polyvinyl acetate and melamine-formaldehyde condensate. There are also binder systems in the form of aqueous solutions, which as binders contain on the one hand copolymers of acrylic acid and acrylic acid esters and on the other hand hexamethylenetetramine or urea. For binder systems, aqueous solutions or aqueous dispersions of certain high molecular weight substances have already been proposed, such as, on the one hand, starch, dextrin, polyvinyl alcohol and certain vinyl acetals or acrylic acid ester polymers and, on the other hand, methylol groups containing compounds, such as melamine-formaldehyde condensate. Finally, there are also binder systems which are based on aqueous solutions and which binders in addition to an aminoplast precondensate contain an ammonia salt of a copolymer prepared from an α4-unsaturated carboxylic acid and an alkyl ester of an α, β-unsaturated monocarboxylic acid, with only insignificant Eislighet in water.

In order for the Adana binder system to produce very water-resistant and elastic coatings, fire-varnishes, the firing temperature and time must be chosen so that the components of the binder can react with each other to the required degree. As a mat harp, you can, for example, use the water hardness and / or elasticity of the lacquer film. Varnish films, which have been produced with too low a firing temperature and / or for a short firing time, are often scattered and / or slightly water-resistant. However, this need not preclude the same binder from forming elastic and water-resistant lacquer films at higher firing temperatures and / or longer firing times. Of many aqueous binder systems, it is thus not possible to obtain any usable lacquer film after, for example, 90 minutes at 1 ° C, while the film becomes usable at 150 ° C.

In order to rationalize the work, it is undesirable to provide such water-soluble binders for the production of fire varnishes, which make it possible to obtain satisfactory varnish films at as low a temperature and / or as short a burning time as possible.

It has now been found that aqueous binder systems can obtain elastic, hard, glossy and water-resistant lacquer films after firing at a relatively low temperature and / or for a relatively short time, if a binder has been added to the binder system which has been obtained from: Dupl. at 22 hours: 3 2—- 10-50% by weight of at least one water-soluble or water-compatible aminoplast precondensate 50-90% by weight of at least one water-soluble ammonia and / or amine salt of a copolymer of 50-90% by weight of an acrylic or methacrylic acid ester with a monohydric, non-polymerizable alcohol, or a mixture of such esters, 5-30% by weight of an α, 19-ethylenically unsaturated mono- or dicarboxylic acid or a mixture of such acids, 2-20% by weight of a monoester of acrylic or methacrylic acid loch a dihydric or polyhydric alcohol or a mixture of such esters and optionally not more than 15% by weight of other copolymerizable monomers, the sum of the percentages according to 1) and 2) and a) -d) amounting to 100.

As aminoplast precondensate 1), condensates of an aldehyde, preferably formaldehyde, and thus condensable, nitrogen-containing amen, are formed with a not very high degree of condensation. Usable aminoplast precondensates can be obtained using, for example, urea, thiourea, melanime, benzoguanamine, o-phenylene-bis (2,4-diaminotriazine-1,3,5), amine, guanidine, dicyandiamide, glyoxalurines, such as glyoxal- di- and -mono-urea, N, N'-dimethylurea, as well as substitution products and derivatives of said compounds. The preparation of such precondensates is within the scope of the present invention and is described, for example, by J. F. Blais in "Amino Resins", (1959), New York, Reinhold Publishing Corporation. For the purpose of the present invention, there are particularly suitable precondensates which can be obtained from urea, melamine, di- or triamine compounds of the 1,3,5-triazine series or mixtures of such compounds. In this case, the aminoplast precondensate may be filtrate with mono- or polyhydric alcohols. Such precondensates are preferred, the methylol groups of which are or partially etherified with methanol.

The copolymers, the ammonia and / or amine salts (hereinafter referred to as "ammonium salts") are used in accordance with the present invention, can be prepared per se, for example by substance, emulsion or solution polymerization. The copolymer must contain in bound form 50-90% by weight of component a), 5-30% by weight of component b) and 2-20% by weight of component c). It may further contain at most 15% by weight of the component d) bound in the polymer, the percentage of a-d being 100%.

As component a) for the preparation of the copolymers, there are, for example, esters of acrylic and methacrylic acid with monohydric, acyclic or cyclic, aliphatic alcohols, which may contain up to 12 carbon atoms. Acrylic or methacrylic acid esters of methanol, ethanol, propanol, n-butanol or isomers thereof, 2-ethylhexanol, cyclohexanol or mixtures of these esters are preferably used. It was found that the acrylic or methacrylic acid esters of n-butanol and above all the acrylic acid n-butyl ester Oro were particularly suitable for use in the invention.

As component b) for the preparation of the copolymers, for example, acrylic, methacrylic, crotonic, itaconic, maleic and fumaric acids or the half-esters of the dihydric acids with monohydric alcohols are used. Acrylic and methacrylic acid are preferably used.

As component c) for the preparation of the copolymer, the monoesters of acrylic and methacrylic acid with dials, such as ethanedio1-1.2, propanedio1-1.2, propanedio1-1.3, butanedio1-1.2 and isomers thereof as well as the pentane and hexanediols. The monoesters of acrylic or methacrylic acid with triols, such as glycerol and trimethylolpropane, can also be used successfully. Furthermore, the monoesters of acrylic or methacrylic acid with tetrahydric and polyhydric alcohols, such as pentaerythritol, can also be used. Component c) Is the most important component of the copolymer to achieve the spirit of the invention. Particular attention should therefore be paid to its nature and abundance.

As an optional component, for example, acrylonitrile, vinyl ether, vinyl ester, vinyl and vinylidene halides, vinyl lactams, acrylic and methacrylamides, C- and N-vinylamines, which may be neutralized or quaternized, vinyl sulfamides and derivatives thereof, vinyl sulfones, vinyl aromatics, such as styrene and methylstyrenes, as well as other unsaturated hydrocarbons and others, a polymerizable double bond containing compounds, if they can be copolymerized with the main components.

For the preparation of the water-soluble ammonium salts of the copolymers, these can be reacted in a simple and per se edge manner with ammonia, amines or ammonia Amite amines. For this purpose, it is generally sufficient to put the copolymers and the nitrogen bases in contact with each other, possibly in solution and during heating.

The ammonium salts of the copolymers may optionally be prepared by replacing the monomeric acid component b) cold or partially with the corresponding monomeric ammonium salts in the preparation of the copolymers, after which the salty polymers are prepared by copolymerization with other polymerizable components. These can then be used directly or possibly after finishing with nitrogen bases.

As nitrogen bases, which can form ammonium salts with the copolymers, according to the present invention, the usual nitrogen bases, i.e. in front of alit ammonia and such amines, whose boiling point at normal pressure Egger below 2 ° C and preferably below 170 ° C. Examples of such amines may be mentioned methylamine, dimethylamine, trimethylamine, butylamine, amylamine, allylamine, 13-hydroxyethylamine, dimethyl- —3, (2-hydroxyethyl) amine, dimethyl- (2-hydroxypropyl) -amine, diethyl- (2-hydroxy-typamine, diethyl (2-hydroxypropyl) amine, morpholine, n-methylmorpholine, ethylenediamine and propylenediamine. containing teriara amines have been found to be particularly suitable, and amine mixtures as well as mixtures of amines and ammonia can also be used.

The upper limit of the boiling point of the amines is mainly due to the fact that the amines can be released from the lacquer film, for example when using the binder systems in fire-lacquers, if they are not chemically bound, because the water hardness of the films otherwise deteriorates. In binder systems, which are processed at relatively very high temperatures, it is therefore possible to use amines, the boiling point of which is Egger Over the specified values under normal conditions.

The amount of ammonia and / or amine is usually chosen so that the finished binder systems in an aqueous environment have a pH of 8-9. For these reasons, 1-1.5 equivalents of nitrogen bases are suitably used per mole of carboxyl groups in the copolymer. It is admittedly possible to use less than 1 equivalent of nitrogen base or more than 1.5 equivalents thereof, although this usually does not bring any benefits.

The aqueous binder systems can be advantageously prepared by combining an aqueous solution of the aminoplast precondensate 1) and an aqueous solution of the ammonium salt of the copolymer 2) in such amounts that the amount ratios between the ram components correspond to the desired dry matter content in the binder system. The amount of bees in this can vary widely and has almost no effect on the properties of the finished varnish. For practical, for example, manufacturing techniques, however, one generally causes binder systems, which contain 10-65% binder. The binder system pH should be 7-10 and heist about 8.0-9.0. If necessary, it can be controlled by the addition of basic or acidic substances, preferably amines and / or ammonia.

The binder system may sometimes contain, in addition to water, also water-soluble, organic solvents, for example alcohols, such as ethanol, or esters, such as glycol monoacetate, or ethers or ketones. Colored products can be obtained in a simple way, by adding pigments or loose dyes to the binder systems. It may also be appropriate to add to these added substances which improve the flow and film formation, such as glycol ethers, acetals, glycols, dimethylformamide, sulfones, sulfoxides and diacetone alcohol. The binder systems can also be continued with corrosion inhibitors and standard curing catalysts for aminoplasts.

These aqueous binder systems can be applied in the usual way when using fire varnishes on, for example, wood, metal, plastic or ceramics, by spraying, brush ironing, rolling, flowing, dipping or impregnation. By heating the well-treated substrate to about 80-180 ° C and raising about 110140 ° C for 10-80 minutes and raising 20-60 minutes, one can obtain insoluble, water-hardy, elastic, hard, glossy and non-yellowing. coatings.

The aqueous binder systems according to the invention are suitable above all for the production of fire varnishes, they can also be used for coatings, films, laminates, impregnation, sizing and gluing. Thus, for example, fabric, cotton wool or paper can be impregnated and, after drying, possibly treated at a higher temperature. In this way it is possible to achieve impregnation or to produce laminates, by laying two or more layers of material treated with the resin solution on a substrate or on top of each other and hardening at higher temperatures, possibly under pressure and processing.

In the following, Agra's illustrative instructions for the preparation of A) solutions of aminoplast precondensate in aqueous media and B) solutions of ammonium salts of copolymers in aqueous media are disclosed, which components according to the invention are suitable for the production of fire varnishes. However, the preparation of the starting materials does not fall within the scope of the invention. However, the solutions of the aminoplast precondensates and the ammonium salts of the copolymers must not be unconditionally prepared according to the rules set forth herein, which are contained only in preferred embodiments.

By parts is meant parts by weight and contents aro shaved in weight in the following.

Preparation of solutions of aminoplast precondensate 1): the amino groups mentioned in the following examples containing the compounds or possibly mixtures of such compounds are heated together with Adana amount of 40% aqueous solution of formaldehyde, that per amino group comes about 2 molecules of formaldehyde. The reaction medium is kept slightly alkaline during the reaction by the addition of soda or sodium hydroxide solution. As soon as alit Or lost, the same amount of methanol is added to the reaction mixture. Then the pH of 4.5-5 is installed by adding oxalic acid at the boiling point. After about 5 minutes, the pH of 10-12 is installed by adding sodium hydroxide solution, after which the reaction mixture is cooled, filtered and vacuum evaporated to about 50% dry matter content.

Preparation of solutions of ammonium salts of the copolymers 2): in a flask equipped with a stirrer and reflux condenser and two inlets, 600 parts of a suitable solvent, for example dioxane or ethanol, are heated to boiling. The heat supply is then switched off, after which 375 parts of a monomer mixture described in the following example were added dropwise over about 1.5 hours. The monomer mixture contains 15 parts of butene-1-01-3 as regulator. Simultaneously with the monomer mixture, a solution of 20 parts of α, α'-azodiisobutyronitrile 1100 parts of acetone was added dropwise through the second inlet. The rate of addition is adjusted so that the solvent is constantly boiling. After addition, the mixture is heated for a further 1.5 hours. The solvent is then largely distilled off to give a residue, which is added with water as well as with an amine and / or ammonia as described in the following examples. Harvid is obtained clear, viscous solution with one. dry matter content of 60-70%.

The invention will be further elucidated in the following with some examples and comparative experiments.

Example 1. The following table lists the properties of fire varnishes which can be obtained with the aqueous binder system according to the invention.

- For the preparation of the fire-paints, mixtures of the solutions obtained according to and B) are first prepared. The components of the arninoplast precondensates and the ammonium salts of the copolymers are listed in the table. The binder system is pigmented with 50% nitrile, shaved onto the binder and sprayed on. emaciated deep-pressing plate, on which the film is burned after venting, as indicated in the table.

In addition to fire varnishes containing the binder system according to the present invention, the table above also describes fire pans which have been obtained in an analogous manner to already existing binder systems. These turn out to be the substrates of the lacquers according to the invention.

* The pendulum hardness »was determined according to W. Konig,« Farbe und Lack », 1953, p. 435.

The abbreviations used in the table have the following table of contents: M = melamine PBT = o-phenylene-bis- (2,4-diaminotriazine-1,3,5) Ka - = urea AB = acrylic acid butyl ester AS = acrylic acid BDM = butanediol1-1.4 -monoacrylate St = styrene AN = acrylonitrile PM / = pentanedio1-1.4-monoacrylate For Starting material * * Composition of the mixture *** Bland-flings fort. (fast-fast) Bran- flings time h Bran-flings temp. oc Erich- sen varde Pcndelhardhet Vatten- hardighet 1 M 70 AB, 22 AS, 8 BDM: 71 16,8 116 god 2 * M 80 AB, 20 AS 25: 71 10,112 satisfactory .3 PBT / Ka = 1 / 1 70 AB, 22 AS, 8 BDM 20: 80 1 19,6 74 satisfactory 4 * PBT / Ka = 1/1 80 AB, 20 AS 20: 80 1 10.8 90 & lig M 68 AB, 11 St , 16 AS, 5 BDM: 80 1 17.6 1god -6 * M 70 AB, 10St, 20 AS: 80 1 10.6 93 7 M 68 AB, 11 AN, 16 AS, 5 BDM: 80 1 18.8 100 * 8 M 68 AB, 11 AN, 16 AS, 5 BDM: 80 1 17.2 99 "9 * M 70 AB, 10 AN, 20 AS 20: 80 1 10.6 107 M 74 AB, 21 AS, 5 PDM: 80 1 17.0 102 11 M 70 AB, 22 AS, 8 BDM 30: 70 1 16.0 122 * KontrollfOrsdk.

** Starting material for the solution of aminoplast precondensate obtained according to A.

*** Composition of the monomer mixture from which the copolymer and the solution of its ammonium salt have been obtained according to B (the copolymers were dissolved in all cases 150 parts of concentrated ammonia during salt formation.

Example 2. This example illustrates the use of a binder system according to the invention for the production of a primer. 91 parts of a total 55% dry matter containing aqueous solution, which have been prepared from the solution of the aminoplast precondensate according to Example 1, Mrs & 7, and the solution of the ammonium salt of the polymer of Example 1, rapids & 7, with a ratio between the dry substances of 23:77. pigmented with 15 parts of iron oxide root, 30 parts of zinc sulphide-barium pigment, 60 parts of shale and 45 parts of talc. The base paint thus obtained is sprayed onto a 0.8 mm thick deep-pressing plate. aerated and fired for 1 hour at 120 ° C. A 0.025 mm thick film is obtained. This is then water-sanded, sprayed with an ordinary topcoat based on alkyd-urea resin and fired for a further 1 hour at 120 ° C. A two-layer film is obtained with very good adhesion between the lacquer layers. The pendulum hardness of the entire lacquer coating Or 67 s and the Erichsen value Or 6.8 mm. The varnish Or resistant to a boiling, 3% detergent solution for 2 hours.

Example 3. A single-strip Procedure B) prepared copolymer of 77 parts of acrylic acid-butyl ester, 7 parts of butanediol-1,4-monoacrylic acid ester and 16 parts of acrylic acid were added with 25 parts of dimethyl- (j-hydroxyethyl) -amine and 100 parts of water, each - .— after the copolymer in a ratio of 77:23 shaved to the dry matter is mixed with a condensate solution prepared according to A) using melamine. This mixture is unchanged after storage for 14 days at 50 ° C. It is pigmented with 50% rutile, shaved off the entire binder, in a ball mill, diluted with water to a spray consistency and sprayed on an emerald deep-pressing plate. After short-term deaeration, the coating is fired for 1 hour at 150 ° C. This results in a nail-hard, glossy film with an Erichsen value of 4.3 at a thickness of 30. The coating is only slightly affected at the edge after storage for 6 days in distilled water.

Example 4. 100 parts of the copolymer described in Example 3 were first charged with 21 parts of dimethyl- (p-hydroxypropyl) amine and then with 100 parts of water. This mixture is then mixed with a condensate solution prepared according to A) using melamine in a ratio of 77:23 shaved on the dry substance. The finished mixture has not changed after storage for 11 days at 50 ° C. Pigmented coatings, prepared according to Example 3 and precipitated for 1 hour at 120 ° C, have at a thickness of g an Erichsen value of 4.8 saint aro harda and bOjhallfasta. They do not show any signs of infestation after storage for 6 days in distilled water.

Example 5. The procedure is the same as in Example 4, replacing the dimethyl- (19-hydroxypropyl) amine with an equivalent amount of N-methylmorpholine. This gives a binder system which remains unchanged after storage for 11 days at 50 ° C. Pigmented coatings prepared according to Example 3 of this binder system and fire are hard and glossy and have an Erichsen value of 3.2. They show no signs of infestation after storage for 14 days in distilled water.

Example 6. A copolymer prepared according to B) of 68 parts of acrylic acid butyl ester, 5 parts of butanediol-1,4-monoacrylic acid ester, 11 parts of acrylonitrile and 16 parts of acrylic acid is divided into 5 batches of 20 parts each. The individual batches are prepared with the amines given in the following table, each dissolved in 20 parts of water and mixed in a ratio of 80:20 shaved on the dry substance with a condensate solution prepared according to A) using melamine. The mixture is pigmented in the manner described in Example 3 and burned on the surface. The properties of the coatings obtained are as follows: Amine dimethyl1 - (- hydr- 1% of B, .. copolymer-arm, 'merisatettid' Fire.- Film- Hard- Pendulum- Boilig temp.thicker- are hardness ° Cleknageln Erich- sell varde Condition after After storage effect 6 h 6 hi water of 10% -ig sodium hydroxide oxiety1) -amine 1 1ja 106 yes 7.2 unchanged single blisters dimethyl1-0-hydro-oxyethylamine 1 1ja 116 yes 4.2 minor attack dimethyl- (3-hydroxyethyl) -amine ammonia 3 1 1ja 1ja 4.2 attacked dimethylamine 12 1 1ja 117 no 3.9 single bubbles Example 7. A copolymer prepared according to B) of 66 parts acrylic acid butyl ester, 7 parts of butanediol-1,4-monoacrylic acid ester, 11 parts of acrylonitrile, 5 parts of acrylamide and 11 parts of acrylic acid were charged with 25 parts of dimethyl (9-hydroxyethyl) amine and dissolved in 1100 parts of water. This solution is mixed with one according to A) using melamine produced by condensate ice in a proportion of 80:20 shaved on dry the substance. The resulting mixture is pigmented according to Example 3, sprayed on plate and fired for 1 hour at 150 ° C. This results in a hard, glossy, non-yellowing coating which, at a thickness of 45, has an Erichsen value of 5.8 and bojhallfast. This film shows no signs of infestation after storage for 7 days in distilled water.

Example 8. A copolymer prepared according to B) of 66 parts of acrylic acid butyl ester, 6 parts of butanediol-1,4-monoacrylate, 11 parts of acrylonitrile and 17 parts of acrylic acid was added with 25 parts of dimethyl- (fl-hydroxyethyl) amine, Rises in water to 60- percent solution and mixed in a proportion of 80:20 shaved on the dry substance with a solution prepared according to A) of a co-condensate of 75% melamine and 25% urea. The resulting solution is pigmented in the manner described in Example 3, sprayed on a deep pressing plate and fired for 1 hour at 150 ° C. This results in a nail-hard, buoyant solid, 28 g thick coating, which has an Erichsen value of 6.0 and good water hardness. .

Claims (2)

Patent claim: Binder for use in aqueous environments, especially for the production of fire-painted paints, characterized in that it has been obtained from: 1. 10-50% by weight of at least one water-soluble or water-compatible aminoplastic condensate 2. 50-90% by weight of at least one water-soluble ammonia and / or amine salt of a copolymer of a) 50-90% by weight of an ester of acrylic acid or methacrylic acid with a monovalent alcohol, or a mixture of such esters 6— .— 3. 5-30% by weight of an α, β-ethylenic food- the sum of the percentages according to 1) and 2) of mono- or dicarboxylic acid or a mixture such as according to a) —d) is 100. of such carboxylic acids 4. 2. -20% by weight of acrylic acid monoester Request publications. or methacrylic acid and a dihydric or polyhydric alcohol, or a mixture of such esters and