DE1645214B2 - Process for the production of crosslinking coating agents - Google Patents

Description

C C = O

/ I I

R ₂ N ^ O
C.

in which R ₁ and R _{2 are} an alkyl, cycloalkyl, aryl or aralkyl radical and R _{3 is} a radical having a polymerizable C =C double bond, and optionally up to 49.5 percent by weight of other monomers, namely acrylic and / or methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-substitution products of these amides, styrene, vinyl esters or olefins, with a component (B) with at least two functional groups, the primary or secondary amino groups, hydroxyl, mercapto and / or Are hydrazide groups, is added.

2. Process for the production of crosslinking coating agents based on solutions or Dispersions of copolymers, at least 50 percent by weight of acrylic or / and methacrylic acid esters, characterized in that a solution or dispersion a copolymer of at least 50 percent by weight acrylic and / or methacrylic acid esters, 0.5 to 30 percent by weight of an azlactone of the general formula

It is known to apply film-forming plastics as a solution or dispersion to a substrate, e.g. B. metal, Wood, paper, cardboard. Apply lids or textiles or to use as a facade coating and then apply the resulting coating to the The course of a crosslinking or curing reaction increased desirable properties, such as insolubility Surface hardness and improved mechanical strength. An example of such networking mechanisms is the networking of predominantly the part of acrylic or methacrylic acid esters consisting of copolymers that are colorless and weather resistance are unsurpassed. These partly consist of methylol compounds or masked metal connections, e.g. B.

Methylol ethers, copolymers built up from acrylic or methacrylic acid amide are optionally additionally crosslinked by the action of catalysts. So far not uneconomical long waiting times are accepted, this crosslinking takes place at temperatures from 120 to 180 C.

The invention relates to a process for Hersteilung of coating compositions based on acrylic or methacrylic acid esters, cross-link even at normal temperature or with gentle heating to about 8O ⁰ C, if appropriate under the action of an acid or alkaline catalyst and quality in this form Make films. Coating compositions of the type according to the invention to be crosslinked are obtained if a solution or dispersion of a copolymer A of at least 50 percent by weight of acrylic and / or methacrylic acid esters and 0.5 to 30 percent by weight of an azlactone of the general formula is obtained

/ Y

R ₂ NO

N /

-C = O

55

C C = O

/ I I

R ₂ NO

N /

60

in which R and R _{2 are} an alkyl, cycloalkyl, aryl or aralkyl radical and R _{3 is} a radical having a polymerizable C =C double bond and up to 49.5 percent by weight of other monomers which contain primary or secondary amino groups, Containing hydroxyl, mercapto and / or hydrazide groups, used and optionally mixed with a catalyst.

in which R ₁ and R, an alkyl. Cycloalkyl, aryl or aralkyl radical and R _{3 is} a radical having a polymerizable C — C double bond, and optionally up to 49.5 percent by weight of further monomers, namely acrylic and / or methacrylic acid, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, N-substitution products of these amides.

Slyrolyn. Vinyl oils or olefins, with a component H with at least functional groups, which are primary h / w secondary amino groups, hydroxyl, mercapto and / or hydrazide groups, added, moderately represented A / lactones are known also as O \ a / designated ol-1,3-onc-5. Dicanggcbenen The two substitutes R _{1 and R 2 of the} azlactone ring can optionally also belong to a carbocyclic or heterocyclic ring. The Formula Gewichtspro / entC are each based on the overall weight of the component A. _J0

As examples of azlactones = oxazolones, those on the structure of the coating compositions to be produced according to the invention may be involved are 2-isopropyl-4,4-dimethyl-oxazolone-5, 1-isopropyl-methyl-4-propyl-oxazolon-5, 2-isopropyl-4,4-dipropyloxazol one - 5, 2-vinyl -4,4-pentamethylene - oxazolone - 5, I-VinyW-methyl - ^ - benzyl-oxazolono, 2-AcrylyloxäthyM-melhyM-cyclohxyl-oxazolon-S and 2-vinyl- * '4-methyl-4-phenyl-oxazolon-5 called.

The polymerization leading to intermediate A. the monomer mixture can be carried out in bulk, solution or emulsion; the copolymer can also be formed as a precipitation polymer and, like the bulk polymer, subsequently dissolved or dispersed.

As component B, low molecular weight bifunctional or polyfunctional compounds can be used as functional Primary or secondary amino groups, hydroxyl, mercapto and / or hydrazide groups included. Examples of such compounds are ethylenediamine.Triaminoethylamine. N, N'-di- (tert-butyl-oxycarbonyU-hexamethylenediamine, N- (aminoethyl) piperazine. Ethylene glycol. Butanediol, glycerine. Dimercaploethane. Ethanolamine or called glutaric acid dihydrazide. In the same sense as the low molecular weight mentioned above Compounds can be used as component B macromolecular compounds with at least two functional Groups per macromolecule are used, e.g. B. polyethylene glycol, polyvinyl alcohol, Polyethyleneimine, epoxy resins, polyesters containing free OH groups or copolymers, some of which from / i-hydroxyethyl (meth) acrylate or / mer-butylaminoethyl (meth) acrylal are constructed. The crosslinking according to the invention finally takes place even when films are produced from such monomers those next to one or more arbitrary monomers and next to the azlactone building block at least contain two functional groups per macromolecule. Such a copolymer can, for. B. off an acrylic ester, an azlactone and a / I-hydroxyethyl methacrylate.

As is known, azlactones can be understood as anhydrides of α-acylamino acids and also from these by dehydration, e.g. B. by means of acetic anhydride ("Organic Reactions", Vol. Ill, 1949, P. 198 ff.). In all cases, therefore, they are derivatives of oxazol-1,3-one-S. As an example for the Production of a polymerizable azlactone is said to be the reaction of α-aminoisobutyric acid with Methacrylic acid chloride and the subsequent ring closure reaction represented by a formula:

C-COOH + H ₂ C = C-CO-CI

/ I 1

H ₃ C NH ₂ CH ₃

H ₃ C

C-COOH

/ I

H ₃ C NH

C = O
H ₂ C = C-CH ₃

H ₃ C

C C = O

/ I I

H ₃ CNO

N /

H ₂ C = C-CH ₃

The monomer obtained in this way can be homo-polymerized or co-polymerized. In the case of copolymerization with acrylic or methacrylic acid esters ^ optionally with other monomers, the azlactone is built into the main chain of the macromolecule _{via the unsaturated polymerizable grouping (designated as R 3 in the formula-based representation of the azlactone mentioned above).} When implementing such a mischo. ·. -.u- ^ Us with a bi- or polyfunctional v \ ;. .i'uj.jng, for example with a diamine, occurs in the sense of the above formulas ring opening and at the same time a linkage of two macromolecules occurs.

CH ₃

N-C

CH ₃

H ₃ C

C-N

H ₃ C

Ο-C = OH ₂ NR-NH ₂ O = CO

c—

H ₃ C ^H \

-C - NH-C - C - NH-R - NH-C - C - NH- C-

As a polymerizable substituent R ₃ , in addition to the isopropyl radical given in the formulas above, the azlactone can carry any unsaturated polymerizable substituent, e.g. B. the vinyl, (Mcth-) AcryIoxyalkyl- or (meth -) - Acrylamidoalkyl grouping. Azlaclones which have the unsaturated substituents just mentioned can be obtained in a simple manner, like the isopropenyl derivative, from an amino acid and the chloride of the _{unsaturated carboxylic acid corresponding to the radical R 3.} Even if in principle all-amino carboxylic acids can be used for the production of the azlactones mentioned, those made from - disubstituted glycines deserve. Particular emphasis should be given to the azlactones which can be prepared from "," - dialkylglycines, in particular that from "," - dimethylglycine. On the one hand, these compounds are sufficiently stable to be able to be prepared in a simple manner and with good yields; on the other hand, they can be readily mixed-polymerized with other monomers, but allow easy and complete crosslinking when reacting with bifunctional or polyfunctional compounds. It must be described as surprising that the azlactones derived from a dialkylglycine, in particular from dimethylglycine, as monomers are stable and easy to handle compounds that mix well, but that the five-membered ring built into such a copolymer is on the other hand under the influence of a bi - or polyfunctional connection opens easily and by means of an addition brings about a connection according to the formulaic representation given above. The fact that dialkylated azlactones can easily be prepared from cheap starting materials on an industrial scale increases their value for carrying out the process according to the invention.

The surprisingly easy crosslinking of the adhesive compositions produced according to the invention is called normal temperatures, if necessary with a slight warming and / or with the addition of z. B. Phosphoric acid or sodium alcoholate as a catalyst has already been mentioned. These coating compounds are previously known products in a number of properties that are decisive for their practical value superior: the crosslinking takes place, and in many cases already at normal temperature, quantitatively. The networking is. as already mentioned, an addition reaction, d. that is, arise when it expires no volatile by-products. They also form in many cases during networking groupings that are extremely stable against hydrolysis, temperature and weathering, as is the case with the Crosslinking with diamines or polyamines, the carbonamide bond already shown in terms of shape; in networking stable ester groups are formed with di- or polyglycols. That the ones with amines cross-linked coating compounds through an excellent

Characteristic for adhesion on most surfaces, it should be mentioned for the sake of completeness.

The following examples explain the invention c Procedure. First of all, under A and B, the production of some starting products for the Coating agents to be used according to the invention are explained.

A. Production of a monomeric azlactone (oxazolone)

1. Preparation of N-Mclhacrylyl- (x-aminoisobutyric acid

In a solution of 10.3% by weight aminoisobutyric acid, 4 parts by weight of sodium hydroxide and 20 parts by weight of water are added dropwise within 2 hours while stirring at the same time 10.4 parts by weight of methacrylic acid chloride and 24 parts by weight of a Sodium hydroxide solution, consisting of 4 parts by weight Sodium hydroxide, and 20 parts by weight of water. By cooling, the reaction temperature is between 0 and 5'C held. Then about 10.5 parts by weight of concentrated hydrochloric acid are added with stirring until the Congo acidic reaction occurs. Of the here. The resulting crystal slurry is quickly filtered off with suction, washed with water and dried at 60.degree. For cleaning, it is recrystallized from ethyl acetate. Yield: 85% N-methacrylyl-fi-aminoisobutyric acid, M.p. 160 to 162 "C

Elemental analysis: 56.1, H 7.9, N 8.3 Found ... C 56.2. H 7.6, N 8.2 calculated ... C

2. Conversion of 1. into 2-isopropenyl- ^v

4,4-dimethyloxazol-1,3-one-5

17.1 parts by weight of N-methyl-acrylyl- «-aminoisobutyric acid are heated with 15.3 parts by weight of acetic anhydride to KX) ¹¹ ° C. with stirring and kept at this temperature for 10 minutes. After fractionation of the reaction mixture *, the azlaclone is obtained in a yield of 80 to 85%. Bp. 63 to 64 ° C / II mm Hg.

Elemental analysis:

Found ... C 62.7, H 7.6, N 8.9%; calculated ... C 62.7, H 7.2, N 9.2%.

B. Copolymerization of azlaclones (oxazolones)

1. Half of a mixture of 50 parts by weight of ethyl acrylate, 40 parts by weight of methyl methacrylate, 10 parts by weight of 2-isopropenyl-4,4-dimethyloxazol-1,3-one-5, 1.2 parts by weight of azoisobutyronitrile and 100 parts by weight of ethyl acetate is placed in the reaction vessel Stirring heated to about 70 "C. After the start of polymerization, the temperature is maintained at about 70 to 80" C. with the addition of the other half of the mixture. 1 hour after

example 1

ok

15th

ίο

At the end of the feed, another 0.2 part by weight of azoisobutyl acidic acid is added added to the solution, which is heated to 70 to 80 ° C. for a further 4 to 5 hours.

2. A mixture of 22 parts by weight of butyl acrylate, 10 parts by weight of acrylonitrile, 30 parts by weight of methyl methacrylate, 30 parts by weight of styrene and 8 parts by weight of 2-isopropenyl-4-methyU4-propyl-oxazoll, 3-one-5 is used with 1.0 parts by weight of azoisobutyric acid in 60 parts by weight of ethyl acetate and 40 parts by weight Methyl ethyl ketone polymerized in the same way.

3. A mixture of 80 parts by weight of butyl methacrylate, 10 parts by weight of N-methyl methacrylamide and 10 parts by weight of 2-vinyl-4,4-pcntamelhylen-oxazole-1,3-one-5 are mixed with 1.5 parts by weight of dilauryl peroxide in 80 parts by weight of ethyl glycol acetate and 80 parts by weight of methyl ethyl ketone in the same way (with the subsequent addition of 0.2 parts by weight of dilauryl hydroxide) polymerized.

4. A mixture of 30 parts by weight of 2-ethylhexyl acrylate, 40 parts by weight of methyl methacrylate, 15 parts by weight of methacrylic acid and 15 parts by weight 2-Vinyl-4-methyl-4-phenyl-oxazol-1,3-one-5 is azoisobutyronitrile with 1.5 parts by weight polymerized in 100 parts by weight of ethyl glycol acetate in the same way.

5. A mixture of 60 parts by weight of ethyl acrylate, 30 parts by weight of methyl methacrylate and 10 parts by weight of 2-isopropyl-4,4-dimethyl-oxazolone-5 is poured into a ^{heated to 80 0} C mixture of 150 parts by weight of deionized water, 4, 5 parts by weight of a nonionic emulsifier, such as isononylphenol, which has been reacted with 50 moles of ethylene oxide per mole, and 0.3 parts by weight of the sodium salt of 4,4'-di-35; stirred in cyano-4,4'-azodivaleric acid. After the addition was complete the temperature is maintained for 2 hours at 8O ⁰ C and then cooled to room temperature with stirring.

6. A mixture of 60 parts by weight of methyl acrylate. 18 parts by weight of vinyl acetate, 12 parts by weight of diethyl fumarate and 10 parts by weight of 2-vinyl-4-methyl-4-benzyl-oxazol-1,3-one-5 becomes 0.9 parts by weight Azoisobutyronitrile in 80 parts by weight of ethyl acetate and 70 parts by weight of methyl ethyl ketone in the same Way polymerized.

Examples of the production according to the invention
the coating agent

In Examples 1 to 5, low molecular weight, in Example 6 high molecular weight crosslinking agents are added.

55

The copolymer solution obtained above under B 1 is mixed with 2.1 parts by weight of ethylenediamine offset

Coating films produced from this solution at 30 ⁰ C are linked by organic solvents such as acetone or Essigesler, these films are slightly swollen, but are insoluble in these solvents.

Example 2

The copolymer solution prepared above under B 2 gives after addition of 2.7 parts by weight Hexamethylenediamine already at drying temperatures of about 30 ° C. in common organic Solvent-insoluble coatings.

Example 3

The mixing prepared above under B 3 poly merisatlösung results after the addition of 2.0 parts by weight butanediol and 0.1 part by weight of p-toluenesulfonic acid at drying temperatures of about 30 ⁰ C, insoluble coatings.

Example 4

The copolymer solution obtained above under B 4 is mixed with 6 parts by weight of adipic acid dihydrazide added and forms insoluble coatings after drying.

Example 5

In 100 parts by weight of the dispersion prepared under B 5 above, 0.78 parts by weight of ethylenediamine are added stirred in. The coating obtained from this mixture after drying at 30 ° C. is in ; organic solvents such as acetone or ethyl acetate, only slightly swollen, stay! but unsolved. A coating produced without the addition of ethylenediamine under the same drying conditions is shown in soluble in the organic solvents mentioned.

Example 6

If the copolymer solution obtained above under B 6 is 50 parts by weight of a 50% solution (in methyl ethyl ketone) of a low molecular weight copolymer of vinyl acetate-vinyl alcohol (80 to 20 percent by weight), which also contains 0.1 part by weight of p-toluenesulfonic acid, are added, the coatings produced from this mixed solution are insoluble.

The following example shows the possibility that the crosslinking functional groups already exist Can be part of the copolymer.

Example 7

A mixture of 35 parts by weight of 2-ethylhexyl acrylate, 40 parts by weight of methyl methacrylate, 15 parts by weight 2-hydroxyethyl methacrylate and 10 parts by weight of 2-acrylyloxyethyl-4-methyl-4-cyclohexyl-oxazol-1,3-one-5 is with 1.5 parts by weight of azoisobutyronitrile in 60 parts by weight of methyl ethyl ketone and 40 parts by weight of ethyl glycol acetate polymerized as usual.

The solution polymer gives insoluble coatings after the addition of 0.1% trichloroacetic acid.

4095467337

Claims (1)

Claims. 1. Process for the production of crosslinking coating agents based on solutions or Dispersions of copolymers, at least 50 percent by weight of acrylic or / and methacrylic acid esters are built up thereby marked that a solution or dispersion of a copolymer (A) of at least 50 percent by weight acrylic and / or Methacrylic acid esters and 0.5 to 30 percent by weight of an azlactone of the general formula 3. The method according to claim 1 or 2, characterized in that the structure of the polymer involved azlactones from an "Au-dialkylglycine, especially the", "- dimethylglycine, derive.