CS232091B1 - Polyester resin and method of its manufacture - Google Patents

Abstract

Polyester resins are on based on acyclic reaction products of 2 to 6 hydroxyl polyalcohols and carboxylic acids or functional derivatives of these compounds. They contain ester-bound polymeric carboxylic acid of average molecular weight weight of 500 to 20 000 or mixtures thereof with resin acids or with their adducts with /, A-unsaturated carboxylic acids with a number of carbon atoms 3 to 6 or with them anhydrides. Said resins are preparing the unsaturated reaction mixture polymers, resin acids, unsaturated carboxylic acids or their anhydrides and acyclic polyalcohols with 2 to 6 hydroxyl groups in the presence of organic solvents or in an inert gas atmosphere at a temperature of 150-260 ° C under the current conditions removing the reaction water until it drops acid numbers below 25 mg KOH / g a the product is optionally de-organic solvents and reaction water distilled.

Description

The present invention relates to polyester resins based on the reaction products of acyclic polyalcohols having 2 to 6 hydroxyl groups and carboxylic acids or functional derivatives of these compounds, with a softening point of 70 to 170 ° C, and a process for their production.

Polyesters of terpendien adducts, called maleate resins, have long been known and have been technically used in the field of paints and printing inks (J. Mleziva et al .: Polyesters, their Production and Processing, 2nd edition, SNTL Prague 1978). These are the reaction products of resin acids, in particular rosin, maleic anhydride and polyhydric alcohols such as glycerol and pentaerythritol. The synthesis of maleate resins most often consists in a one-step reaction of all starting components. In the two-step preparation, the adduct of maleic anhydride and rosin is usually prepared in the first stage, which is further subjected to esterification with a polyalcohol. In another method, the intermediate is first obtained from maleic anhydride and a partial amount of polyalcohols required, and the intermediate thus obtained is further reacted with rosin and the remaining amount of polyalcohols. This results in very hard and brittle products which are sometimes poorly soluble in common organic solvents and insufficiently compatible with various synthetic lacquer resins.

The above-mentioned drawbacks are overcome by the present invention, which relates to polyester resins based on the reaction products of 2 to 6 hydroxyl groups of acyclic polyalcohols and carboxylic acids or functional derivatives of 232 091 of these compounds, with a softening point of 70 to 170 ° C, and a process for their preparation. The essence of the present invention is that the polyester resins contain 80 to 96 wt. % ester-linked polymeric carboxylic acids having an average molecular weight of 500 to 20,000 or mixtures thereof with 5 to 95 wt. Polyester resins or their adducts with (, 1-unsaturated carboxylic acids having from 3 to 6 carbon atoms or with their anhydrides). Polyester resins are prepared by subjecting a single or sequential reaction to a mixture of unsaturated polymers, resin acids,. unsaturated carboxylic acids having 3 to 6 carbon atoms or their anhydrides and acyclic polyalcohols having 2 to 6 hydroxyl groups in the presence of organic solvents, in particular xylene, or in an inert gas atmosphere at a temperature of 150 to 260 ° C with simultaneous removal of the water of reaction an acid number below 25 mg KOH / g, whereupon the final product is optionally freed of organic solvents and reaction water by distillation at a pressure of 1 to 10 kPa.

The polyester resins of the present invention have a number of advantages over known maleate resins. They are characterized by great hardness, good toughness and brittle bones. Their softening point is between 70 and 170 ° C and their acid number is between 5 and 70 mg KOH / g. They are very soluble in conventional organic solvents such as aromatic hydrocarbons, ketones and esters. Easy to do. mixed with lacquer binders such as oils, alkyd resins, epoxy resin esters and cellulose derivatives. All these features can be varied to a large extent both by selecting different types and quantities of starting components and by changing production technology.

The polyester resins of this invention are the reaction products of acyclic polyalcohols and carboxylic acids or derivatives of these starting materials.

232 091

The alcohol component is acyclic polyalcohols containing 2 to 6 hydroxyl groups. They include, in particular, glycols, such as ethylene glycol, propylene glycols, butylene glycols, neopentyl glycol, diethylene glycol, dipropylene glycol, triethylene glycol and other polyalkylene glycols, and trihydric alcohols such as glycerol, 1,1,1-trimethylethane,

1,1,1-trimethylolpropane, 2,3,4-pentanetriol, 1,2,3-trihydroxy butane, 1,2, n-hexanetriol and tetravalent to hexavalent alcohols such as pentaerythritol, dipentaerythritol, arabitol, sor bitol , xylitol, mannitol. The polyalcohols or derivatives thereof are used singly or in admixture with each other for esterification. Glycerol and penerythritol are of utmost technical importance.

The acid component is predominantly represented by polymeric carboxylic acids based on topopolymers and copolymers of tC, β-unsaturated carboxylic acids or their anhydrides or modified unsaturated polymers thereof having an average molecular weight of 500 to 20,000. methacrylic, crotonic, maleic, fumaric, citraconic, pyrocinohonic, mesaconic, itaconic or their respective anhydrides, especially maleic anhydride. Among the homopolymers of N, N-unsaturated monocarboxylic acids, polyacrylic acid and polymethacrylic acid are particularly suitable. Copolymers of said unsaturated carboxylic acids and their anhydrides contain as mono-olefins such as ethylene, propylene as comonomers; butenes, pentenes, hexenes, heptenes, vinyl chloride, vinylidene chloride, vinyl acetate, (meth) acrylic and allyl compounds, cyclopentenes, cyclohexenes, indene, ethylindenes, coumarone and diolefins (butadiene, isoprene, piperylene, dimethylbutadiene, chloroprene, cyclopentenes, hexadienes, hexadienes, hexadienes, hexadienes dicyclopentadiene, cyclohexadiene). For copolymerization with unsaturated acids, either single monomers with one or two double bonds or different mixtures thereof may be used. Instead of said comonomers, k can be used

232 091 copolymerization or addition of an unsaturated acid component using their liquid oligomers, co-oligomers or low molecular weight homopolymers and copolymers containing double bonds.

The second acid component includes resin acids or adducts thereof with N, N-unsaturated carboxylic acids and anhydrides thereof. The rosin starting material is rosin. It contains mainly abietic and levopimaric acid, neoabietic, palustric, dehydroabietic, hydroabietic, dextropimaric and isodextropimaric. For the addition to the resin acids, the abovementioned A, Λ-unsaturated monocarboxylic and dicarboxylic acids and their anhydrides, in particular maleic anhydride and acrylic acid, can be used.

The production of the polyester resins of the present invention generally involves known processes in which polymeric carboxylic acids, optionally together with resin acids or adducts thereof, are subjected to direct esterification with polyhydric alcohols at a temperature of up to 250 ° C. The acid components used are usually prepared in advance by the addition of N, N-unsaturated carboxylic acids or their anhydrides, preferably maleic anhydride, to the starting polyunsaturated polymers and also separately to the rosin resin acids. Preferred is a process for the synthesis of these adducts only in the first stage of the preparation of polyester resins by said maleization of a mixture of unsaturated polymers and resin acids at a temperature of 150 to 210 ° C. The next step is to esterify the resulting carboxylic acids with polyalcohols, mainly glycerol and pentaerythritol, at a temperature of 180-200 ° C. The reaction is terminated upon reaching the desired acid number and softening point of the polyester resin.

The polyester resins according to the invention are particularly suitable for the preparation of paints, printing and marking inks, adhesives, sealants and paper sizing.

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The invention is further illustrated by the following examples. Softening temperatures of polyester resins are determined according to ČSN 65 7060.

Example 1

The polyester resin comprises 92 wt. an ester-linked polyraeric carboxylic acid with a final molecular weight of 600. This polyraeric carboxylic acid is prepared by the addition of 8 wt. parts by weight of maleic anhydride to 92 wt. parts of a copolymer of pentene, hexene, indene, styrene, butadiene, cyclopentadiene and dicyclopentadiene. This polyester resin was prepared by melting 934 g of a polyraeric carboxylic acid based on the above copolyraer and maleic anhydride with 79 g of glycerol with the addition of 30 g of xylene. This mixture is subjected to gradual azeotropic esterification at 230 ° C, whereby the acid number falls below 10 mg KOH / g. Xylene is distilled off at 10 kPa. A hard polyester resin having a softening point of 75 ° C is obtained.

Example 2

Polyester resin containing 87 wt. ester-linked carboxylic acids consisting of a 92 wt. parts of rosin and 8 wt. parts by weight of polyraeric acid prepared by the reaction of 12 wt. parts of acrylic acid with 88 wt. parts of a copolymer of isoprene, piperylene, pentene, hexene, cyclopentadiene and indene, with a final molecular weight of 18,500.

g of polyarboxylic carboxylic acid prepared from the above described copolymer is melted in a flask with 840 g of rosin and 134 g of pentaerythritol and subjected to azeotropic esterification at 170 ° C with the addition of 25 g of xylene. The esterification is terminated when the acid number falls below 10 mg KOH / g and xylene is distilled off at 1 kPa. The polyester resin obtained had a softening point of 132 ° C.

Example 3 232 091

Polyester resin containing 92 wt. % of ester-linked carboxylic acids formed by a mixture of 93 wt. parts of a polyraeric carboxylic acid prepared by Priedl-Crafts reactions of pentene, hexene, cyclopentadiene, indene, butadiene and maleic anhydride, with a final molecular weight of 1,500 and an acid number of 80 mg KOH / g and 7 wt. parts of rosin.

This resin is prepared by placing 871 g of the above polymeric carboxylic acid in a flask together with 66 g of rosin and 79 g of glycerol and melting and esterifying the mixture by introducing a nitrogen stream at 260 ° C until the acid number falls below 10 mg KOH / g. The softening point of the obtained resin is 162 ° C;

Claims (2)

Polyester resins based on the reaction products of 2 to 6 hydroxyl groups of acyclic polyalcohols and carboxylic acids or functional derivatives of these compounds, having a softening point of 70 to 170 ° C, characterized in that they contain 80 to 96% by weight. ester-linked polymeric carboxylic acids having an average molecular weight of 500 to 20,000 or mixtures thereof with 5 to 20,000 95% wt. resin acids or their adducts with 3 to 6 carbon-unsaturated carboxylic acids or their anhydrides. λ 2. A process for the production of polyester resins according to claim 1, characterized in that a mixture of unsaturated polymers, oleic acids, γ (, β-unsaturated carboxylic acids having 3 to 6 carbon atoms or their anhydrides and acyclic polyalcohols) is subjected to a single or successive reaction. with 2 to 6 hydroxyl groups in the presence of organic solvents, in particular xylene, or in an inert gas atmosphere at a temperature of 150 to 260 ° C, while removing the reaction water until the acid number falls below 25 mg KOH / g, solvents and reaction water by distillation at a pressure of 1 to 10 kPa.