HU207110B - Process for producing alkyd resins modified with vinyl compounds - Google Patents

Abstract

1-30% ketone resin comprising a hydroxyl gp. reacts with alkyd resin. The reaction mixt. (calculated 20-60% dry matter) is then dissolved in an aromatic solvent, heated and when the solvent reaches the boiling point the vinyl monomer and the initiating mixt. are added. The copolymerisation is carried out till the required viscosity is reached

Description

The present invention relates to a process for preparing alkyd resin solutions modified by copolymerization with vinyl compounds.

It is known that polycondensation resins are prepared by reacting polycarboxylic acid, anhydride monocarboxylic acid or a mixture thereof and polyalcohols between 160 ° C and 260 ° C (Patton: Alkyd resin technology, 1962, New York),

Water from the reaction is continuously removed from the system, for example by azeotropic distillation. In order to improve the properties of the coatings made of polycondensation resins, so-called binders are used. modifying components are incorporated. By using drying oils or their fatty acids as modifiers, they produce air-drying polycondensation resins, or commonly known as air-drying alkyd resins.

In recent decades, developments in the composition of alkyd resins have focused on the chemical association of various lower or higher molecular weight materials, and the ability to combine them with different chemical species. physical mixing to change the film-forming properties of alkyd-based binders to a greater or lesser extent: drying, hardness, elasticity, chemical resistance ... etc.

One part of a wide variety of modifications is the addition of high melting point hard resins to the alkyd resin during or at the end of cooking. Examples of such conventional hard resins include pine resin, cyclohexanone resins, phenolic resins, various types of hydrocarbon resins, and high molecular weight vinyl and alkyd resins associated with alkyd resins. acrylate polymers. The latter modifying agents generally improve the drying properties, but often the coating's antifreeze, chemical resistance, and compatibility with other resin types are impaired. Therefore, usually more technically valuable resins can be obtained by copolymerization of alkyd resins with vinyl monomers, such as styrene, vinyl toluene, acrylate or methacrylate monomers, as disclosed, for example, in U.S. Patent 3,34,050.

Binders made by copolymerization of so-called oil-modified alkyds with vinyl monomers are characterized by fast drying, good chemical and weather resistance and good alkali resistance (Payne, Η. E, "Organic Coating Technology" Vol. 1, 1954). Although styrene is the most commonly cited vinylating monomer in the literature, copolymerization with mixed styrene and acrylate monomers has several advantages. Various solutions are known in the literature for vinylation of alkyd resins. A common solution for unsaturated oil or pre-styreneation of the fatty acid component; acrylic and then polycondensation cooking. The addition of monomers at the same time as the polycondensation reaction also occurs. However, the reproducibility of cooking cannot always be guaranteed in these cases, and the propensity of homopolymerization of monomers can often cause incompatibilities and turbidity. Therefore, it is preferable to use unsaturated fatty acids and / or fatty acids. technology for the subsequent vinylation of alkyds containing oil components. Again, careful selection of the unsaturated component of the alkyd resin and the composition of the monomer mixture, the type of peroxide catalyst that promotes radical polymerization, the reaction temperature, the type and concentration of the solvent are required to achieve the appropriate degree of copolymerization [Benner, F. et al; Off. Dig. 31, 1143 (1959)]. The most commonly used unsaturated oil components are fatty acids and fatty acids with conjugated double bonds. oil derivatives (usually dehydrated castor oil or wood oil) and possibly a proportion of lower iodine derivatives. semi-drying oil; fatty acid mixture. Polymerization is ideally accomplished by addition to grafting on the unsaturated bonds of the alkyd resin.

If the chain reaction is only initiated between the monomers, the resulting high molecular weight polymer molecules become incompatible with the alkyd and turbidity occurs due to gelation or limited solubility. Even if the graft copolymerization is only partially carried out and a clear treatable solution is obtained, it is possible that the non-incorporated polymeric portions may impair the coating resistance, permeability, or adhesion properties. mechanical properties. Therefore, for the vinylation of conjugated double bonds in the most commonly used compositions, different chain transfer activators or initiators are used in addition to the initiators. regulating additives are also used.

In our studies, it has been surprisingly found that, when modifying oily alkyd resins, ketone formaldehyde resins containing free hydroxyl groups (OH number of 50-400 mg KOH / g), in addition to these hard resins (m.p. 50-150 ° C, DIN 53180) improves the drying and coating hardness of alkyd resins (see Invention No. 176069) to unexpectedly significantly improve the vinylation properties of these alkyds. The oil-modified alkyd resin has a tendency to copolymerize to such an extent that, in contrast to prior art, semi-drying oils and / or semi-drying oils are no longer required. dehydrated castor oil containing a higher proportion of conjugated double bonds in addition to fatty acids; application of wood oil.

It is believed that the reason for this phenomenon is that the ketone or aldehyde groups incorporated into the alkyd resin, when placed adjacent to the unsaturated bonds, loosen their electron structure by conjugation and play a controlling, regulatory role in graft polyaddition.

According to the invention, one or more polycarboxylic acids, anhydrides or monocarboxylic acids, or mixtures thereof, and one or more polyalcohols, optionally in the form of a triglyceride, are reacted at a temperature of from 160 to 260 ° C. with continuous removal of water from the reaction such that the reaction mixture has a concentration of 50 to 400 mg KOH / g hydroxyl and a melting point of 50 to 150 ° C,

The ketone resin containing 110 Β hydroxyl groups was added and the resulting alkyd resin was dissolved in an aliphatic or aromatic solvent to a solids content of 20-60% by weight. The resin solution contains from 5 to 80% by weight, based on its solids content, preferably from 20 to 40% by weight of vinyl monomer, preferably styrene, (meth) acrylate monomer or a mixture thereof, and from 0.5 to 10% by weight of the monomers. The initiator is decomposed at a temperature of 20-180 ° C and copolymerized to a solids content of 40-60% by weight.

Preferably, the ketone resin containing hydroxyl groups is cyclohexanone-methylol resin, alkylcyclohexanone-methylol resin, cyclohexanone-formaldehyde resin, acetophenone resin, acetophenone-formaldehyde resin, or a mixture of two or more thereof. Ketone resins containing hydroxyl groups are known and can be prepared, for example, as described in British Patent No. 864451.

Examples of polyalcohols that can be used in the process include ethylene glycol, propylene glycol, butanediol, hexanediol, dimethyl-1,3-pentanediol, 2-ethyl-1,3-pentanediol, dimethylolcyclohexane, polyethylene polypropylene glycols, glycerol, trimethyl, trimethyl, trimethyl, 2,4-butanetriol, pentaerythritol, sorbitol, mannitol, dipentaerythritol.

Examples of polycarboxylic acids are: phthalic acid, isophthalic acid, terephthalic acid, hexahydro-phthalic acid, endomethylene-tetrahydrophthalic acid, hexachloro-endomethylene-tetrahydrophthalic acid, maleic acid, fumaric acid, itaconic acid or their respective anhydrides, adipic acid, sebacic acid or sebacic acid.

Suitable monocarboxylic acids are, for example, benzoic acid, p-tert-butylbenzoic acid, hexahydrobenzoic acid, acrylic acid or other aliphatic, cycloaliphatic or aromatic monocarboxylic acids.

Styrene, α-methylstyrene, vinyltoluene, chlorostyrene, acrylic acid and methacrylic acid as drying or semi-drying oil components are methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, 2-ethylhexyl, cyclohexyl. , decyl, lauryl ester and acrylic acid nitrile; an appropriate mixture of these may be used.

Suitable initiators include peroxides and azo compounds decomposing between 50 and 150 ° C, such as, for example. benzoyl peroxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide, di-tert-butyl peroxide, and azo-bis-isobutyronitrile.

Embodiments 2, 3, and 4 below illustrate the process of the present invention. Example 1 was prepared for comparative purposes using a conventional formulation and technology.

EXAMPLE 1 (Conventional Preparation of Medium-Length Vinylated Alkyd) Part of soy fatty acid, 21 parts of phthalic anhydride, 13 parts of benzoic acid, 21 parts of pentaerythritol was heated to 220 ° C. Under vigorous gas flow, the mixture is stirred at this temperature while the resulting water is removed from the system by azeotropic distillation. When the acid number of the reaction mixture drops below 10 mg KOH / g (DIN 53402), the resin is cooled and diluted to 35% by weight with xylene. 7.8 parts by weight of styrene, 12 parts by weight of isobutyl methacrylate and 0.2 parts by weight of ditert-butyl peroxide are then added. The solution is heated to reflux (160-180 ° C) under reflux.

By measuring the viscosity (DIN 53211) and the solids content (MSz 9650/8), the flow time is 300 s, solids content 45 wt%, monomer content 33 wt%.

Example 2 (Modification of the composition and final parameters of Example 1 according to the procedure) parts by weight of soy fatty acid, 3.6 parts by weight of benzoic acid, 21 parts by weight of phthalic anhydride, 16 parts by weight of pentaerythritol and 15.4 parts by weight of cyclohexanone formaldehyde 270 mg KOH / g) was heated to 220 ° C. Under vigorous gas flow, the mixture is stirred at this temperature while the resulting water is removed from the system by azeotropic distillation. When the acid number of the mixture drops below 10 mg KOH / g, the resin is cooled and diluted to 35% by weight with xylene. 7.8 parts by weight of styrene, 12 parts by weight of isobutyl methacrylate and 0.2 parts by weight of ditert-butyl peroxide are then added. The solution is heated to reflux (160-170 ° C) under reflux.

Discharge time: 300 s, oil content: 33 wt%, solids content: 45 wt%, monomer content: 33 wt%.

EXAMPLE 3 15 parts by weight of soybean oil, 15 parts by weight of dehydrated castor oil in the presence of 0.02 parts by weight of lead oxide were heated to 250 ° C with 16 parts by weight of pentaerythritol. After the transesterification is complete, the reaction mixture is cooled to 130 ° C and 22 parts of phthalic anhydride and 3 parts of eiclohexanone methylol resin (hydroxyl number 370 mg KOH / g, melting point 110 ° C) are added. The reaction mixture is heated to 210 ° C in the presence of 5 parts by weight of xylene and the water formed during the reaction is removed by azeotropic distillation under an inert gas stream. The condensation was continued until an acid number of 10 was reached and an outlet time of 250 s (60% in white spirit) was reached.

Upon completion of the polycondensation, the reaction mixture was cooled and diluted to 30% by weight with white spirit. Then heat to reflux of the solvent and add the following monomer mixture through a dropping funnel to the boiling solution: Styrene: 17 parts by weight

Butyl acrylate: 15 parts by weight

Lauryl methacrylate: 6 parts by weight

Tert-butyl hydroperoxide: 2 parts by weight

Cooking continues until the following parameters are obtained:

Discharge time: 250 s

Solids content: 50% by weight

Oil content: 25% by weight

Vinyl monomer content: 57% by weight

HU 207 110 B

Example 4: Parts of tallow fatty acid, 18 parts of pentaerythritol, 0.5 parts of maleic anhydride, 18 parts of phthalic anhydride and 7.5 parts of acetophenone formaldehyde resin (hydroxyl number 170 mg KOH / g, melting point 105 ° C) were heated to 5 parts xylene. After an reaction time of eight hours, the product had an acid number of 5 mg KOH / g and an outlet time of 60 seconds in 60% w / w solution of white spirit. The reaction mixture was cooled and diluted with white spirit to 60% solids. A mixture of 2 parts of butyl methacrylate, 3 parts of cyclohexyl methacrylate, 1.4 parts of styrene, 0.1 part of benzoyl peroxide, 0.1 part of methyl ethyl ketone peroxide and 4.4 parts of methyl isobutyl ketone was added. After heating to reflux, heat the reaction mixture until the parameters of the resin solution have reached the specified values.

Discharge time: 120 s, oil content: 55 wt%, solids content: 60 wt%, vinyl monomer content: 10 wt%.

Example 5

All were carried out as in Example 3, but 50 parts by weight of resin diluted to 60% by weight with white spirit were mixed with parts by weight of styrene, parts by weight of butyl acrylate, parts by weight of lauryl methacrylate,

3.5 parts by weight of a mixture of azo-bis-isobutyronitrile.

Hereinafter, the copolymerization was continued as described in Example 3.

For the purpose of comparing the properties of the binder solutions prepared according to the embodiments, each of these was prepared in the same manner by desiccating varnishes, the coating properties of which are documented in the comparative table below.

Test method 1 st Example 2 Ex. 3 Example 4 Example 5 traditions agent tucked away. of tucked away. of tucked away. of tucked away. of Drying (MS-KGST) 1442.20 ° C 1st grade, (Hours) 2 1.5 1.2 1.5 1.2 7th grade, (Hours) 24 12 6 20 5.5 Hardness after 1 week (MS 9640/4),% 30 35 46 32 48 Adhesion (MSz- 9650/25) 2 0 0 0 0 Flexibility (MSZ 9640/6) mm 6 8 8.5 9.5 8.7

The results of the test confirm that the binder solutions prepared according to the process and / or in their drying and mechanical properties, varnishes exceed the so-called varnishes. coating characteristics of a sample made by conventional vinylation.

Compatibility tests

1 st Example 2 Ex. 3 Example 4 5, e.g. Alkyd resin (short oil length) + 4- + - + Alkyd resin (medium oil length) - + + + + Alkyd resin (high oil length) - + + +: Acrylate resin solution (aromatic) ± + + + + Acrylate resin solution (gasoline) - + ± +

Legend:

+ compatible

- incompatible ± limited fit

Compatibility tests are performed by mixing the resin solutions in the ratio 9: 1 and 1: 9. Well miscible in all ratios, limited miscible in only certain proportions, and non-miscible in all samples, resulting in a clear, clear solution. The table shows that it is the least

The composition of Example 1 may be combined with other binders.

Claims (1)

A process for preparing alkyd resin solutions modified with vinyl compounds wherein one or more polycarboxylic acids, anhydrides or monocarboxylic acids, or mixtures thereof, and one or more polyalcohols, optionally in the form of a triglyceride, are reacted at temperatures between 160 and 260 ° C. with continuous removal of water by adding to the reaction mixture a ketone resin having hydroxyl groups of 50-400 mg KOH / g and hydroxyl groups having a melting point of 50-400 mg. Dissolved in an aliphatic or aromatic solvent to a solids content of up to 110% by weight, characterized in that the resin solution contains from 50 to 80% by weight of the vinyl monomer, preferably styrene, (meth) acrylate monomer or a mixture thereof, and 0.5-10% by weight of the known initiator, decomposed at 50-150 ° C, is added at 20-180 ° C, and the mixture is copolymerized to 4060% by weight of solids.