DE1495287A1 - Cover compositions hardenable by means of heat - Google Patents

Description

Coating compositions curable by means of heat

It is known that vinyl copolymers containing carboxyl groups can be used from two or more vinyl monomers, at least one of which has a carboxyl group. Example these are methacrylic acid, acrylic acid and crotonic acid.

Copolymers of this type can advantageously be used in thermosetting coating compositions in connection with one or more substances that react with it, e.g. an epoxy resin, an amine resin or an epoxidized one vegetable oil. The compositions can be clear or pigmented.

Alternatively, these acidic copolymers can be used in - ^ orm of the corresponding salts with volatile bases such as ammonia or amines in coating compositions which can be diluted with water use with water-thinnable amine resins.

The invention provides a method for making acrylic copolymers to which both carboxyl groups and hydroxyl groups are attached, and it further relates to Use of such copolymers in coating compositions.

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The first manufacturing step involves creating one Copolymers of maleic anhydride with one or more Acrylic monomers. liesea tiach polymer with attached anhydride groups is then treated with a compound or composition that has at least two alcohol groups, with at least the molecular equivalent of alcohol per anhydride group is used will. On this iVelae the anhydride groups are converted into the corresponding Transformed half-ester groups. Below is a « Illustration of this process for glycerine.

QH CH +
f I CH ₂ OH CH CH
t I co co CH OH COOH COOCH ₂ O CH ₂ OH CHOH CH ₂ OH Maleic acid
anhydride mixed
polymer Glycerin Modified Mi3Ch-
polyaer

To prevent premature gel formation. prevent, ea is two-dimensional, an excess of polyalcohol of 5 to 30? » On the Requires 1 molecule of polyalcohol to be used per anhydride group.

The modified x-secondary polymers know through a treatment with a volatile base, e.g. ammonia *: or a! Amine, transformed into the corresponding roll form, in thicker form they can be used in coating compositions which can be diluted with aeur.

Both in the acidic form and in the Jaiz form, this is the case modify copolymers in overexposure to aliein or in connection with amine resins, epoxy resins and other polyfunctional

partial materials can be used. '

BATH ORIGINAL

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The maleic anhydride copolymers themselves are expediently in solution in a volatile ^ tromatic solvent such as benzene, xylenes or commercially available higher-boiling aromatic solvents. If necessary, you can other solvents such as methyl ethyl ketone either alone or use in admixture with an aromatic solvent, provided that the solvent does not have functional groups which can react with an anhydride group.

It is preferred to use initiators such as the organic peroxides and hydroperoxides. Furthermore, you can optionally Use smaller amounts of chain rearrangement agents and initiator activators, which do their usual known job fulfill.

To avoid possible difficulties with exothermic reactions To avoid and to ensure the production of a more uniform product, it is advisable to use all mixed monomers and to bring initiators or a partial amount into the solvent, which then for a certain time on the desired Temperature is maintained.

Preferred mixed monomers are the esters of methacrylic acid and the esters of acrylic acid, in particular the alkyl esters in which the alkyl group contains at most four carbon atoms. One can use two or more mixed monomers to modify the properties of the final composition. Vinyl mixed monomers such as styrene or vinyl toluene can also be used, but the mixed monomers should in all cases contain at least 25 percent by weight of the preferred acrylic esters. The preferred proportion of maleic anhydride is 5 to 50 percent by weight of the total monomers present. _onQ

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BATH ORIGINAL

The selected polymerization temperature is aioh naoh

the initiator or initiation system used in each case. i

If the polymerization is carried out at reflux temperature, however, it results in a convenient control of the temperature of the process.

The polyalcohol used to modify the maleic anhydride copolymer was known to be a simple polyhydroxyalkane, _for example glycerol or trimethylolpropane. It is also possible to use a more complex material, for example a partial fatty acid ester of glyoerine, which arises, for example, as a reaction product of a polyhydric alcohol and a triglyceride vegetable oil, an alkyd resin with residual hydroxyl groups or a condensate of a polynuclear phenol with epiohydrin.

The modification of the Maleinsäureanhydridmischpolymers is expediently carried out at total reflux and at temperatures between 80 and 150 ° C. In order to prevent premature ßelbildung, it is necessary to use at least one molecular equivalent \ of polyalcohols per anhydride group. In the case of a complex substance that takes part in the reaction, e.g. * in the case of an alkyd resin, an average value is taken for the molecular weight of the substance in question, which is checked by means of a test reaction.

The alkyd resin preferably has an intermediate hydroxyl value from 50 mg KOH / g.

When the reaction between the maleic anhydride isohpolymer and the substance participating in the reaction is complete, which can be seen from the fact that the acid value does not go any further

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decreases, one adds an alcohol or alcohol-ether solvent to get a clear solution when cold.

Used in coating compositions that can be diluted with water one simple polyhydric alcohol, e.g. trimethylolpropane or glycerin, to the maleic anhydride copolymer modify. One must provide a minimum amount of maleic anhydride in order to obtain a product which, after neutralization is water soluble with a base. This minimum amount depends on the type and amount of the initial polymerization step mixed monomers used. If you consider the lower monomers as mixed monomers Alcohol esters of methaoryl and acrylic acid used, shows it is found that 8 percent by weight maleic anhydride based on the total amount of monomers is normally sufficient. Using of a hydrocarbon monomer such as styrene is a higher one Proportion of maleic anhydride required. If a good solubility in water is to be achieved, the amount of Styrenes or vinyl toluene do not exceed the amount of lower alkyl acrylate or methacrylate.

Since the solvent used in the polymerization step is immiscible with water, it is advisable to distill it off at reduced pressure. The modification with polyalcohol is then carried out in the absence of the solvent, and the product is finally treated with ammonia or a volatile amine before the dilution with alcohol and / or alcohol-ether solvents is carried out, optionally mixed with water. A content of alcohol or alcohol-ether solvent is desirable because the coating compositions produced from these products at their appropriate for use viscosity, a sufficiently high proportion of non-volatiles ^hold ent · 909832/1370

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Alternatively, you can use one throughout the process Use a water-miscible solvent provided it does not contain groups that will react with an anhydride group and that it is a suitable solvent for the preliminary polymerization step. Examples for single solvents are ethylene glycol monoethyl ether monoacetate and iie dimethyl ether of ethylene glycol, diethylene glycol and similar glycols and glycol ethers.

The maleic acid half-ester misohpolymers according to the invention can be used advantageously in coating compositions in conjunction with one or more of the following substances:

Amine resins, possibly alkylated, epoxy resins, alkyd resins, Pol; apoxy compounds such as vinylcyclohexenedioxide, epoxidized vegetable oils, maleic anhydride copolymers, phenol-formaldehyde condensates and formaldehyde-modified alkylamide and substituted acrylamide copolymers.

The salts of these maleic acid half-ester misohpolymers can also be used with volatile bases in coating compositions with water-thinnable amine resins, aqueous dispersions of epoxy resins and water-dilutable phenol-formaldehyde condensates.

The hardening of these compositions, which can be clear or pigmented, takes place in the oven and expediently at temperatures between 120 and 200 ° C, optionally in the presence of small amounts of curing accelerators, surface-active substances and other modifiers, each of which performs its various known functions.

Since the maleic acid half-ester copolymers according to the invention

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containing both hydroxyl ale and carboxyl groups, it is believed that better curing (ouring) with the methylol or the alkylated methylol of amine resins and with formaldehyde modified aotylamide isohpolymers compared to that is possible, which is achieved with a vinyl copolymer containing only carboxyl groups. This is analogous to the known Alkydamine resin coating compositions for which it is considered safe it applies that the function of the carboxyl groups of the alkyd resin is mainly catalytic, while the hydroxyl groups of the alkyd resin mainly with the functional groups of the amine resin react.

Further details and advantages of the invention emerge from the following description of several exemplary embodiments.

Example 1 Part A - Manufacture of a maleic anhydride ethyl acrylate Miaoh Polymers.

The following materials were in a 2 liter bottle given:

Maleic anhydride 10 g Ethyl aorylate 20 g _fc Ditertiary butyl peroxide 1g * Technical xylene 490 g

This batch was stirred and completely refluxed heated. At reflux, the following thoroughly mixed materials were added as a continuous stream over 90 minutes:

Maleic anhydride 39 g Ethyl aorylate 421 g Ditertiary butyl peroxide 14 g The batch was refluxed for an additional 2 hours.

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The mixed polymer solution was clear and the content was non-volatile Fabrics was 49.0 #.

Part B - Modification of the product according to Part A.

380 g of the product according to Part A were placed in a SOO ccm bottle. The xylene was distilled off at a pressure of about 50 mm Hg, with the temperature finally reached HO ⁰ C. The resin was cooled and the bottle vented to atmosphere. After cooling to 80 ° O, 20 g of glycerin was added and the batch was reheated to 135 ° C at full reflux. After staying at 135 ° C for two hours, the batch was cooled. The acid value of the product was 53 mg KOH / g. After cooling down, the following materials were added:

880 ammonia 19 g

Isopropanol 10 g

Water 160 g

After thorough stirring, a clear solution was obtained a $ 50.0 non-volatile content and viscosity from 880 Stoke. The solution could be diluted with unlimited amounts of water without precipitation of the resin.

Part c - Use of the mixed polymer half ester.

A part of the product according to Part B was with a third of its weight based on the non-volatile substances recrystallized Hejcamethoxymethylmelamin mixed. This The mixture was ground in a ball mill with a sufficient amount of titanium dioxide pigment so that a ratio of Gave 0.75: 1 between the pigment and the binder. The paste was made with a 3: 1 isopropanol-water mixture on a viscose • tat of 100 see (cup No. 4 B.S.S.). This color was sprayed onto tin-plated metal sheets, which were placed in the oven for 30 minutes at

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120 ° C were baked, ^ he resulting films had a excellent gloss, they were tough, they withstood wiping with xylene for 1 minute, and the alkali resistance was excellent. After further stoving at 120.degree. C. for one hour, the films showed only a slight loss of gloss or white appearance.

Example 2

Of the product A according to Example 1, 67 g of 100 g of Synolao 41X (modified with oil "45 # oil length" alkyd resin at 50 # non-volatile content Substances in commercial xylene made by the Cray Valley company Products Ltd., England) and heated on a steam bath. After 3 hours the product was cooled.

A mixture of non-volatile substances 4 parts of this product with 1 part of a commercially available butylated Helamine formaldehyde condensate was in the ratio 3 * 1 diluted with xylene and ethylene glycol monoethyl ether to a viscosity of 120 see (Ford-Beoher No. 4) and degreased galvanized bleoh sprayed. In the oven at 150 ° C for 30 minutes treated film was tough and flexible and showed good adhesion. The film held for 1 minute to wash with xylene was standing.

Example 3

200 g of the product A naoh Example 1 and Epikote 828 (registered trademark), a commercially available Diphenylolpropane-epichlorohydrin condensate, 50 g on a Steam bath heated to full reflux for 3 hours.

A mixture of 4 parts of this adduct and 1 part of one

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commercially available butylated melamine formaldehyde condensates the non-volatile substances were given a 3 * 1-öemisoh aua Xylene and Äthylenglyoolmonoäthyleäther diluted to a viscosity of j 120 ββο (Ford cup No. 4) and degreased tinned Sprayed sheet metal. These were in the oven for 30 minutes at 150 ° G treated. Clear films with good solvent resistance resulted.

Example 4 -

Part A - Preparation of an 80:20 (weight percent ethyl aorylate-maleic anhydride copolymer.

The following materials were placed in a 2 liter bottle:

Maleic anhydride 10 g

Ethyl aorylate 20 g

Commercial xylene 490 g

iDitertiary butyl peroxide 1 g

The batch was heated to reflux and the following mixture was released as a continuous stream over the course of 90% min attached:

^ Maleic acid anhydride 88 g

Ethyl aorylate 372 g

Ditertiary butyl peroxide 14 g

The chafge was refluxed for a further 2 hours, and a clear solution of $ 50.5 non-volatile was obtained Fabrics.

Part B - Production of a maleic acid half-ester mixed polymer:

The following materials were in a 1 liter bottle given

Alkali Refined Soybean Oil 439 g (1 mol equivalent)

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Glycerin 92 g (2 molar equivalents) lead acetate 0.176 g

The above mixture was heated to 240 ° C. under nitrogen with stirring, held at this temperature for 40 minutes and then cooled down; the product is referred to as B in the following.

The following materials were packaged in a 500-com bottle given:

Product B 99.3 g

Product according to Part A 250.0 g

The batch was heated to full reflux and Maintained at this temperature for 3 hours. After cooling to room temperature, 100 g of normal butanol were added, with would result in a clear, pale yellow solution, denoted by C in the following will.

Relief treatment in the oven:

a) Product 0-5 parts based on the non-volatile substances. 1 part of a commercially available butylated melamine-formaldehyde condensate, also related to the non-volatile substances,

This mixture was made with a 2: 1 mixture of xylene and Butanaol diluted to a viscosity of 120 see (Ford cup no. 4) and sprayed onto tin-plated metal sheets. The sheets were held in the oven at 120 ° C for 30 minutes; this became a soft one clear film achieved. Rubbing the film with xylene for 1 minute did not remove the film.

b) Product C - 5 parts based on the non-volatile Fabrics. 1 part of a commercial diphenylolpropanepichloroedrin (Epoxy equivalent 190 to 210 g).

This mixture was mixed with a 2: 1 xylene-butanol mixture

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diluted to a viscosity of 120 see (Ford cup no. 4) and sprayed onto tinned sheet metal. After treatment in the oven at 150 ° for 30 minutes, the result was a clear, tough film that was wiped off could not be removed with Sylol for a period of 1 minute.

Example 5

The following materials were placed in a 2 liter bottle:

Commercial xylene 490 g

Tertiary dodecyl mercaptan 1 g

The mixture was heated to full reflux, then the following pre-made solution became more continuous Electricity added over the course of 2 hours:

Styrene 264.6 g

Butyl acrylate 176.4 g

Maleic anhydride 49 »0 g

Ditertiary butyl peroxide 14.7 g

After the completion of the admixture, the mixture was further Refluxed for hours. The batch was cooled to 80 ° C. and 73.7 g of 'trimethylolpropane (1.1 moles each Anhydride group) added. The batch was again set to 130.degree heated and kept at this temperature for a further 2 hours, While cooling, 200 g of ethylene glycol monoethyl ether were added. The product was a clear, water-white solution ..

Trial treatment in the oven:

a) In relation to the non-volatile substances, the following mixture was used:

Modified maleic anhydride copolymer 70 parts

Commercially available butylated melamine-formaldehyde condensate - 15 parts

Commercially available diphenylolpropanichlorohydrin condensate
poxy equivalent 190 to 210

epichlorohydrin condensate - ^ 15 parts

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This mixture was diluted to a viscosity of 120 seconds (Ford cup no. 4) with a 2: 1 mixture of xylene and butanol and sprayed onto tin-plated metal. These were treated in the oven at 150 ° 0 for 30 minutes. ^{ώ β} emerged clear tough films that could withstand wiping with xylene for at least 2 min.

b) In relation to the non-volatile substances, the following mixture was used:

Modified maleic anhydride copolymer 1 part

Modified acrylamide A bulk polymer 5 parts

It was the modified aorylamide isohpolymer is a formaldehyde-modified and then butylated styrene-acrylamide copolymer.

The mixture was diluted with a 2: 3 mixture of xylene and butanol to a viscosity of 120 seconds (Ford cup no. 4) and then sprayed onto bonded steel sheets for 30 min treated at 150 ° G in the oven. -It emerged clear and tough films which cannot be wiped off by wiping with xylene (2 min) or let it soften.

Based on the non-volatile substances, the following mixture was used:

Modified maleic anhydride misoh polymer Part 1

Synolao 12X 1 part

(Synolao 12X is a % 7 $ oil length "soybean oil which was used to modify an alkyd resin and which is marketed in this form by Gray Valley Products Ltd, England ^.)

The mixture was made with a 2i1-ötmisoh from xylene and Butanol to a viscosity of 120 see (Ford-Beoher No. 4)

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thin, sprayed onto clean stick sheet and then treated in the oven for 30 minutes at 180 ° C. ^ ₈ tough, clear films with excellent resistance to xylene were produced.

Example 6 ,

A paint was made exactly according to Example 1, however then with 10 Gewiohteproient (based on the non-volatile Binder) of the bisphenol-epilorohydrin condensation product (Epoxy resin), which is available under the trade name Epikote 812. Films on tinned sheets that Oven at 150 ° 0 for 30 minutes were flexible and had good resistance to solutions of detergents.

Patent claims:

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Claims (17)

-15- U95287 - PATENT CLAIMS 1. Method for sharing a heat-curable Acrylic mixed polymer, characterized in that, with the aid of a polyhydric alcohol, a mixed polymer of maleic anhydride with Miaohmonomermaterial selected from the group of maleic anhydride copolymerizable aoryl and vinyl compounds is, is esterified, the mixed monomer material at least »At least 25 percent by weight of an alkyl acrylate or methacrylate the alkyl group of which contains at most four carbon atoms, the amount of the polyhydric alcohol used at least one molecular equivalent per anhydride group in the copolymer is equivalent to. 2. ^ experience according to claim 1, characterized in that the Mixed monomer paint consists exclusively of acrylic material. 3. The method according to claim 1, characterized in that the mixed monomer material of otyrene or vinyl toluene together with consists of at least the same weight of an alkyl ester of acrylic or methacrylic acid, the alkyl group being at most four Contains carbon atoms. 4. ^ experience according to claim 1 to 3> characterized that the proportion of maleic anhydride in the copolymer is sufficient is high to allow the polymer material to dissolve in aqueous alkali. 5. The method according to claim 1 to 4, characterized in that that the interpolymer has at least 5 percent by weight of maleic anhydride units contains. 6. The method according to claim 1 to 5 »characterized in that the amount of polyhydric alcohol 1.05 to 1.3 mol each Corresponds to anhydride group. 909832/1370 7. The method according to Aspruch 1 bia 6, characterized in that that the polyhydric alcohol is a polyhydroxyalkane. 8. The method according to claim 1 to 6, characterized in that the polyhydric alcohol is a partial fatty acid ester of the GUycerins is. 9. The method according to claim 1 to 6, characterized in that the polyhydric alcohol is an alkyd resin with residual hydroxyl groups is. 10. The method according to claim 1 to 6, characterized in that that the polyhydric alcohol is a condensate of polynuclear phenol '- and is epichlorohydrin. 11. Half ester of a polyhydric alcohol with a maleic anhydride Acrylic micropolymer. 12. Half-ester according to claim 11, characterized in that essentially all maleic anhydride groups with the polyvalent one Reacted to alcohol. 13. Paint, varnish, varnish or the like., Characterized by a volatile solvent and - as a film-forming agent - a balbester according to claim 11 or 12. 14. paint, varnish, varnish or the like., Characterized by a half ester according to claim 11 or 12 ale carrier substance together with an amine resin, an epoxy resin, an epoxidized vegetable oil, an alkyd resin, a phenol-formaldehyde resin or a vinyl isohpolymer with added N-methylol, carboxyl or hydroxyl groups. 15. Half-ester according to claim 11 or 12 in the form of a salt with a volatile base. 909832/1370 -π- H95287 16. Half-bed according to claim 15 »characterized by its Combination with water-thinnable amine, alkyd or phenol-formaldehyde resin or a water-dispersible epoxy resin. 17. Maleic anhydride-Llischpolymer-HailÄater, marked by its preparation according to the examples given. The patent attorney: 909832/1370