CS214028B1 - Process for preparing a modified vegetable oil and vinyl monomer based resin - Google Patents

Abstract

The invention relates to a method for preparing modified resins based on vegetable oils and vinyl monomers, used in the air-drying paint industry. These are resins formed by the reaction of maleated esters of fatty acids of drying vegetable oils and a copolymer containing hydroxyl groups, formed by an ester of the general formula 2 í a 2 l 2 Rx 0 OH and a monomer from the group of vinyl aromatic hydrocarbons and/or vinyl esters of aliphatic carboxylic acids and/or alkyl esters of (£,4-unsaturated carboxylic acids

Description

The invention relates to a process for the preparation of modified resins based on vegetable oils and vinyl monomers used in the air drying paint industry. It is a resin formed by the reaction of maleicized fatty acid esters of drying vegetable oils and a hydroxyl group-containing copolymer of an ester of formula ( ²⁾ and ( ^{2 ) 2.}

R _x OH and a monomer selected from the group of vinyl aromatic hydrocarbons and / or vinyl esters of aliphatic carboxylic acids and / or alkyl esters of (E, 4-unsaturated carboxylic acids)

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In the paint industry, binders for air-drying coatings form a significant part. In addition to binders in which the coating film is produced by a physical mechanism, i.e. by simply evaporating the solvent, such as nitrocellulose, polystyrene solutions, various dispersion systems called latexes and the like, there are also binders in which, in addition to physical solvent evaporation, film of a double bond polymerization reaction resulting in crosslinked polymeric materials. The basic raw materials for this group of substances are in most cases fatty acids of drying vegetable oils, of which

with polyol and aromatic diacid form alkyd resins which can be further modified with suitable reactive monomers such as vinyl hydrocarbons, acrylic monomers, silicone modifiers and the like. In many cases, however, the modified oil feedstock itself is utilized in copolymerized products, using similar reactive materials to the modified alkyds. The products obtained by this process are usually cheaper than alkyd resins and yet in many application areas fully meet the requirements of consumers. Depending on the degree and manner of modification, these binders dry only physically or both.

Previous processes for preparing vegetable oil and vinyl monomer resins have been based on copolymerization of double bonds of vinyl monomers and double bonds of unsaturated fatty acids to achieve component compatibility, since vinyl homopolymers or copolymers are incompatible with or soluble with fatty acids or their esters. This reaction, however, leads to a loss of reactive double bonds of unsaturated acids such that the mechanism of oxidative polymerization curing upon drying is strongly suppressed.

Also, the preparation process using copolymers with reactive groups capable of reacting with the modified oil component does not always give satisfactory results, either because of the slow progress of the reaction or because too high a temperature causes the copolymerization of the oil and modifier component.

It has now been found that the above disadvantages are overcome by a process for preparing a modified resin, characterized in that a reaction of 0.1 to 25 wt. of maleic anhydride with 99.9 to 75 X wt. triglyceride and / or alkyl ester of C 1 -C 4 unsaturated vegetable fatty acids at 190 to 220 ° C, after which the product of this reaction is reacted in a ratio of 1: 4 to 1: 0.05 with a monomer mixture consisting of 0.1 to 50% hm. of an ester of the general formula

where R 1 = -H, -CH ₃

R ₂ = -H, -CH _3, -CHgCl and 50 to 99.1 wt%. monomer containing one vinyl group selected from the group consisting of vinylic, aromatic hydrocarbons, vinyl esters of acids of aliphatic carboxylic Selin * · (C - Cjjj) alkyl ". ^ - unsaturated carboxylic acid (alkyl C - _Cg), or mixtures thereof at a temperature of 120 to 160 ° C in the presence of a polymerization initiator in the environment of maleinized unsaturated vegetable fatty acid esters.

The resulting product properties can be determined to a wide extent by the process of the invention. The average molecular weight and hence the viscosity of the prepared solutions can be influenced both by the degree of maleisation of the oil component and by the composition and amount of the vinyl copolymer. The binders obtainable according to the invention have a modifying polymerization component incorporated through ester bonds, thereby retaining the reactive double bonds of the unsaturated fatty acids necessary for oxidative polymerization curing when air dried. In addition, perfect compatibility of otherwise immiscible components is achieved.

As esters of inaleinized fatty acids of drying vegetable oils, for example, reaction products of maleic anhydrides with soybean, linseed, dehydrated castor oil, sunflower oil and the like, as well as methyl, ethyl, propyl and butyl esters of fatty acids of these oils, or tall fatty acids. Of the vinyl aromatic hydrocarbons, styrene, vinyltoluene and their halogenated derivatives can be used in particular. The copolymerization is carried out in the presence of polymerization initiators, in particular organic peroxides and hydroperoxides such as diacyl peroxides, dialkyl peroxides, monoalkyl hydroperoxides and the like.

Resins obtainable by the process of the invention can be used as binders for the preparation of quick drying coatings, impregnation and penetration varnishes, binders for abrasive materials and other purposes.

Example 1.

K 80 wt. parts of refined soybean oil, treated for 80 minutes with 4 wt. parts of maleic anhydride (200 DEG C.) at 140 ⁿ C dropwise over 4 hours a mixture of 50 wt. parts by weight of styrene, 12 wt. parts by weight of 2-hydroxypropyl methacrylate, 5 wt. parts of vinyl acetate and 2 wt. parts of di-tertiary butyl peroxide. The temperature is maintained for a further 2 hours and a 60% solution in xylene is prepared. The viscosity of this solution is 202 mPa · s / 25 ° C and the acid number is 15.4 mg KOH / g.

Example 2.

To 45 wt. parts of linseed oil and 10 wt. parts of the fatty acid methyl ester of dehydrated castor oil reacted with 3 parts of maleic anhydride for 1 hour at 200 DEG C. are added dropwise a mixture of 70 wt. parts of vinyltoluene,

0.8 wt. % of 3-chloro-2-hydroxypropyl acrylate and 1.7 wt. % of cumene hydroperoxide. The reaction is complete after 2 hours of reaction at the same temperature, whereupon a 60% solution in xylene is prepared. The viscosity of this solution is 2120 mPa · s / 25 ° C and the acid number is 20.4 mg KOH / g.

Example 3.

wt. parts of tall oil fatty acid methyl esters are reacted at 250 ° C with 6 wt. parts of maleic anhydride. A 20 wt.% Mixture was added dropwise at 135 ° C over 4 hours. parts of butyl methacrylate, 10 wt. parts by weight of 2-hydroxyethyl methacrylate and 1 wt. part of dibenzoyl peroxide. The reaction was completed by heating at the same temperature for 2 hours. The product is soluble in xylene and the 60% solution has a viscosity of 164 mPa · s / 25 ° C and an acid number of 38.2 mg KOH / g.

Claims (1)

Process for preparing a modified resin based on vegetable oils and vinyl monomers, characterized in that a reaction of 0.1 to 25 wt. % maleic anhydride with 99.9 to 75 wt. triglyceride and / or alkyl ester of C 1 -C 4 unsaturated vegetable fatty acids at 190 DEG-220 DEG C., after which the product of this reaction is reacted in a weight ratio of 1; 4 to 1: 0.05 with monomer mixtures consisting of 0.1 to 50 wt. an ester of formula wherein R 1 is -H, -CH ₃ R 8 is -H, -CH ₃ , -CHgCl and 50 to 99.1 wt. a monomer containing one vinyl group selected from the group consisting of vinyl aromatic hydrocarbons, C ₈ -C ₁₈ aliphatic carboxylic acid vinyl esters, C ₆ -C ₈ alkyl esters of C 1 -C 6 alkyl or mixtures thereof at a temperature of 120 to 160 ° C in the presence of a polymerization initiator in the environment of maleinized unsaturated vegetable fatty acid esters.