CS233154B1 - Alkyd resins and process for their preparation - Google Patents

Abstract

The invention enables the preparation of alkyds used as a binder for paints, with more advantageous properties, in particular a shortened drying time, increased weather resistance, reduced yellowing and better mechanical properties. Its essence lies in the fact that alkyd * resins prepared by the reaction of carboxylic acids, polyhydric alcohols and isocyanates or derivatives of these components contain, from the total amount of hydroxyl groups present in the reaction components, 10 to 35% of free hydroxyl groups, 6 to 11% of hydroxyl groups bound after reaction with isocyanates and 50 to 85% of ester-bound groups. Of the total amount of bound alcohols, 15 to 65% by weight are specified acyclic polyhydric alcohols and 35 to 85% by weight are polymeric alcohols based on copolymers of styrene with acrylic esters and hydroxyesters and optionally unsaturated acyclic monocarboxylic acids with C 13 to 22 and an iodine number of 120 to 200 g Jg/100g.

Description

The invention relates to alkyd resins based on polymer alcohols and other components, which are excellent binders for paints.

Among modern synthetic paint binders, for example based on polyester, polyurethane, polyamide, polyepoxide and polyacrylic resins, alkyd resins still hold the first place. This is mainly because their starting materials are available and relatively cheap. The production of resins themselves is not complicated and the resins are easily processed into paints. Alkyds are prepared by reacting polyalcohols with natural oils or their monocarboxylic acids and with polycarboxylic acids or their anhydrides.

Alkyd resins are well pigmented, have excellent film-forming properties and are capable of crosslinking by air drying or baking. However, coatings based on them also have some disadvantageous properties, such as slow drying of films, their softness, stickiness, tendency to yellowing, low resistance to water, alkalis and acids. To eliminate these shortcomings, common types of alkyd resins are chemically or physically modified. Chemical modifications include primarily the reactions of alkyds with unsaturated compounds, especially maleinization (Australian patent No. 407 538, German patent No. 2 441 935), cyclopentadienization (Belgian patent No.

832 962, German patent No. 1 520 174), siliconization (USSR patent No. 394 406, US patent No. 3 948 827) and urethaneization (German patent No. 1 644 750 and 1 644 801) Of the chemical modifications, styrenation (French patent No. 1 518 562, pa2

233 154 tent UK No. 1 376 194 etc.), and more recently acrylates (US Pat. 3 374 194 and UK Pat. 957 367). However, it is difficult to prepare homogeneous and long-term stable alkyds with these properties, as well as alkyds for paints with long-term weather resistance. Physical modifications include mixtures of alkyd resins with reactive and non-reactive macromolecular substances, for example with rachovinoformaldehyde, rahelaminoformaldehyde resins (Belgian Patent No. 874 241, French Patent No.

192 155, German patent No. 2 710 994), phenol-formaldehyde (Belgian patent No. 833 822, European patent No. 2 488) and natural (Czech Patent Office No. 155 002, Japanese patent No. 74 102 407) as well as vinyl polymers (German patent No. 1 770 299, US patent No. 3468826) and elastomers (Australian patent No. 293 252 and 425 563). ^Paints based on these modified alkyd resins usually dry faster, the cured coatings are hard, shiny and resistant to chemicals. Although some properties of physically modified alkyds are improved compared to the properties of alkyds without modification, other properties are negatively affected by the modification. For example, Alkyds modified with urea-formaldehyde or raelaminoformaldehyde resins are used mainly for baking types of paints. When using the optimal ratio of alkyds and modifying components, the hardness of the paint film is significantly improved, but in areas outside the optimum of this ratio, brittleness increases sharply and adhesion of the paint film is reduced. The addition of a special phenol-formaldehyde resin to alkyds leads to an increase in the hardness of the paint films, but the disadvantage is their poor drying in the presence of free phenols, so it is necessary to use resins free of phenolic components for modification, which are more expensive. The disadvantage of natural resins is their fluctuating quality and the resulting need for their modification. Longer types of alkyds are suitable for modification with chlorinated rubbers, short alkyds are not suitable for modification, in addition, the use of chlorinated rubber requires the simultaneous addition of special plasticizers.

233 154 kators. However, the resistance of the coatings to some more aggressive solvents will then decrease.

The adverse properties of modified alkyds are addressed by this invention, the subject of which are alkyd resins based on reaction products of carboxylic acids, polyhydric alcohols and isocyanates, or alternatively substituted or functional derivatives of these components, and a method for their preparation. The essence of the invention lies in the fact that, of the total amount of hydroxyl groups present in the starting reaction components, alkyd resins contain 10 to 35% of free hydroxyl groups, 6 to 11% of hydroxyl groups bound after reaction with isocyanates, mainly by the -NH-000- bond, and 50 to 85% of hydroxyl groups bound by esters. Of the total amount of bound polyhydric alcohols, 15 to 65% by weight are acyclic alcohols with 2 to 5 carbon atoms and 2 to 4 hydroxyl groups, and 35 to 85% by weight are polymer alcohols, prepared by radical copolymerization of 1 mole of styrene with 0.35 to 1.70 moles of esters derived from acrylic or methacrylic acid and acyclic monohydric alcohols with a number of carbon atoms of 1 to 4, .02 to '©,'30 moles of hydroxyesters derived from these acids and acyclic dihydric alcohols with a number of carbon atoms of 1 to 4 and optionally up to β 0.10 moles of acyclic unsaturated monocarboxylic acids with a number of carbon atoms of 13 to 22 and an iodine number of 120 to 200 g Jg/IQO g. The essence of the method of preparing these alkyd resins lies in the fact that 300 to 550 wt. parts of a 40 to 60% solution of polymeric alcohols in organic solvents, preferably in xylene, is allowed to react at a temperature of 130 to 180 °C for 0.5 to 3 h with 15 to 160 parts by weight of a cyclic dicarboxylic acid anhydride having a number of carbon atoms of 8 to 10. Then 10 to 500 parts by weight of acyclic monocarboxylic acids having a number of carbon atoms of 13 to 22 and/or their hydroxyesters derived from acyclic alcohols with 2 to 4 hydroxyl groups and 2 to 5 carbon atoms and optionally up to 2

233 154 parts of monocarboxylic and/or dicarboxylic acids with a number of carbon atoms of 6 to 10 and up to 160 parts by weight of acyclic alcohols with 2 to 4 hydroxyl groups and 2 to 5 carbon atoms. The mixture is heated to a temperature of 220 to 250 °C and allowed to react with gradual distillation of xylene and reaction water until the acid number of the reaction mixture drops below 5, preferably below 2 mg KOH/g. The product is then cooled to a temperature of 80 to 110 °C and subjected to a reaction with 10 to 50 parts by weight of a diisocyanate with a number of carbon atoms of 9 to 12, wherein at any stage of the reaction the reaction mixture is diluted with 200 to 550 parts by weight of xylene and/or white spirit. After achieving at least 90% conversion of isocyanate groups, the resin preparation is terminated by adding 5 to 25 parts by weight of n-butyl alcohol and/or isobutyl alcohol.

Alkyd resins according to the invention are characterized by better parameters compared to conventional and modified alkyds. They show significantly reduced drying time in all evaluated stages, have improved resistance to weathering, reduced yellowing and excellent mechanical properties. Due to the significantly reduced content of acyclic monocarboxylic acids compared to other comparable types of alkyds, which is achieved by using polymer alcohols prepared on the basis of mainly domestic raw materials, a significant economic advantage of this type of alkyd is also obvious.

Alkyd resins prepared according to this invention are reaction products of polymeric alcohols and polyalcohols with acyclic mono- and dicarboxylic acids and mono- or dicarboxylic aromatic (cyclic) acids.

The first group of alcoholic components consists of polymer alcohols obtained by radical copolymerization of monomer components, namely styrene, esters and hydroxyesters of acrylic or methacrylic acid with mono- to dihydric acyclic alcohols with 1 to 4 carbon atoms and optionally also acyclic monocarboxylic unsaturated acids with an iodine number of 120 to 200 g Jg/100 g. These reaction components are in the order in which they were

233,154 reported, represented in the molar ratio 1/0.35 to 1.70/0.02 to 0.30/ to 0.1.

The copolymerization is preferably carried out in a xylene environment to form a 40 to 60% solution of the polymer alcohol in xylene. The prepared polymer alcohols have a molecular weight of 1,500 to 8,000, a hydroxyl number of 6.5 to 43 mg KOH/g and an acid number of 1 to 20 mg KOH/g.

The second group is polyhydric acyclic alcohols containing 2 to 4 hydroxyl groups. These are glycols (e.g. ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, diethylene glycol, dipropylene glycol and higher polyethylene glycols), alicyclic diols (such as 1,2- and 1,4-cyclohexanediol, 1,4-bis(hydroxymethyl)cyclohexane), hydrogenated or alkylene-oxidized bisphenols (2,2-bis(4-hydroxycyclohexyl)propane, 2,2-bis(4-hydroxyethoxyphenyl)propane, 2,2-bis(4-hydroxypropoxyphenyl)propane. Of the trihydric alcohols, these are mainly glycerol, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, 2,3,4-pentanetriol, 1,2,3-trihydroxybutane, 1,2,6-hexanetriol, tris(2-hydroxyethyl)isocyanurate, and from the group of tetrahydric polyalcohols, pentaerythritol is suitable. The alcohols mentioned are used individually or preferably in mixtures with each other.

The acid components involved in the preparation of alkyds according to the present invention belong to two groups by their nature. First of all, they are acyclic monocarboxylic acids with a straight chain, containing 4 to 22 carbon atoms, which occur in mixtures of various compositions in vegetable oils in the form of triglycerides. Of the vegetable oils, linseed, soybean, dehydrated castor, rapeseed, sunflower, cottonseed, safflower, oiticica and some other oils are considered, the iodine number of which is in the range of 90 to 200 mg Jg/100 g. In the production of alkyds, both the aforementioned oils and the acyclic acids isolated from the aforementioned oils can be used.

Another acid component that can be used in the preparation of alkyds according to the present invention are aromatic acyclic

233 154 monocarboxylic or dicarboxylic acids or their functional derivatives, especially anhydrides. These include, for example, benzoic acid, p-toluic acid, p-tert-butylbenzoic acid, phthalic anhydride, isophthalic acid and adipic acid.

Organic diisocyanates are used for the urethanization of alkyds, e.g. a technical mixture of 2,4- and 2,6-toluyl diisocyanate containing approximately 80% by weight of 2,4-toluyl diisocyanate, isophorone diisocyanate and 1,6-hexamethylene diisocyanate.

The alkyd resins according to the invention can be prepared in all variants in accordance with the scope of the invention. It is possible to start from acyclic monocarboxylic acids or their triglycerides, i.e. in particular from vegetable oils, and to work in a multi-stage process.

In the production process using vegetable oil as the starting ingredient, the following preparation method has proven to be effective:

The reaction of a polymer alcohol with a cyclic dicarboxylic acid anhydride produces an acid ester. This reacts with mixed hydroxyesters of monocarboxylic acyclic acids formed by catalyzed alcoholysis of vegetable oils with polyalcohols. In addition to the hydroxyester and possibly other polyalcohols, monocarboxylic cyclic and dicarboxylic cyclic acids, or possibly acyclic dicarboxylic acids, participate in the reaction. The esterification of the named components with azeotropic removal of the reaction water from the system produces an intermediate product, an alkyd resin containing free hydroxyl groups, which then react with the added diisocyanate to form a carbamic acid ester.

For clarification, we present the meaning of some terms used in describing the preparation of alkyds and their characterization. The conversion of esterification or other reactions is understood as the proportion of reacted carboxyls or other functional groups, given in equivalents, expressed as a % of their initial amount. The ratio between alcoholic and carboxyl components, denoted as R, expresses

233 154 ratio of alcohol equivalents to carboxylic acid equivalents in the initial batch:

^e B

R -- ^e A (e.g. 1 mole of pentaerythritol corresponds to 4 equivalents of alcohol and 1 mole of phthalic anhydride corresponds to 2 equivalents of carboxyl groups).

The subject of the invention is illustrated by the examples. The polymer alcohols contained therein are specified in more detail in Table 1. The characterization of the alkyds mentioned in Examples 1 to 6 is contained in Table 2.

Table 1

233 154

Composition of polymeric alcohols

Polymer alcohol A B C D E Representation of monomers in the reaction mixture (molar ratio): styrene 1 1 1 1 1 ethyl acrylate - 0.65 - 0.23 1.06 butyl acrylate - 0.10 0.036 0.14 0.12 methacrylate 1.04 0.53 0.38 0.69 , 0.36 2-hydroxyethyl acrylate - 0.020 0.060 - . 2-hydroxyethyl methacrylate 0.028 - - - - 2-hydroxypropyl acrylate — 0.050 — 0.040 0.23 acid dehydrate. castor oil 0.086 0.003 linseed oil acids 0.046 initiator used di-tert- butyl- peroxide target- butyl- peroxy- benzoate di-tert- butyl- peroxide - di-tert- dibutyl- cumyl peroxide per- xid % in the reaction mixture 1.5 2 1.5 1.8 2 reaction temperature 133-138 130-137 132-138 132-138 130-13 viscosity of 50% solution in xylene (mPa.s/20 °C) 800- 1100 1000- 1500 1200- 1600 1500- 2000 1800- 300' average molecular weight 1500 4200 6200 7500 8000 hydroxyl number (mg KOH/g dry matter) 6.45 10.82 7.25 24.0 43.0 acid number (Cng KOH/g dry matter) 1 20.5 10.3 1.00 - -

VO •M

233 134 ca •k what

VO

C— *

t—

CA la

VO 1 «Φ 1 CA •to | •to About cn i CM what r- í CM

·.

«MIA

What is the name of the city?

O

CM

CM *

CA •k la

In the c—

L.A.

WHAT tM· •k

CA

WHAT

CA •k v— trCA

WHAT

CM ûn

CM

Table 2 Characterization of alkyd resins from examples 1 to 6 ca tvo vo

CA

9.

CA

CA

CA —

CA

CA —

VO

CA

VO

MCM

About *k o

VO

About •k

About 'M'

C— •k

VO

CM

CM CO 1 CM ·* •to | *k LA «Μ- 1 In~ VO CA I CA

>»

H

O

XI

O

Li

H cd 'Φ •P >»

Φ

O

Ή ř>

VO

LA •k

WHAT

VO *

WHAT •to vt vo

LA cA

CA «ΜO

VO

M with

Φ &

O

PM 'Φ

M >> OH •rl O H Xí Js O

OH «4 3 'Φ !>> cí d cd Ή i> P. o d fc(W cd Φ Φ d'® N S> Φ o dH 'Φ o d d Η H >?o d d II -H •KOH P< II Φ dž Λ4 I M 'Φ >'Φ O

I « oo do •dox? ¹ ra

Or

O o d >>d W N r*S -P d'3'® cd í> 1> >H O odfi fcO® 3 titix φ d ' cd cd d-M

Or 1 •d 1 3 N •d About about About H 1 H H xí about 1 •d » About xí 1 and H d Λ4 about 1 About •rl > Li ' 1 I d PU I H • and d •d d >d I 3 -P 1 φ í*» 55 d 2 ¹ H xí 05 í> Φ •rl É * ><1> Λ4 P4 >N 05 xí i d xí Xi Φ about >Φ | td about about H p3 About I '>ϊ WHAT ra χ-x 1 that d >

νφ d 3 'cd o5 ί» φ d >® o

d

Φ

At 3 p<d •rl &» P< •p h d ra

P4 K m ffl «4 φ φ

II to

233 154

Example 1

Ingredients I: linseed oil glycerol trimethylolpropane lead oxide

Components II: polymer alcohol A (50% xylene solution) phthalic anhydride

Components III:

Dehydrated castor oil acid phthalic anhydride parts by weight 158.48

96.82

37.86

0.025

504.86

19.10

12.62

132.36

The reaction components I are gradually weighed into a stainless steel reactor and, with stirring and a constant supply of inert gas, the mixture is heated to 250 °C and left at this temperature until maximum miscibility with methyl alcohol is achieved. The temperature of the reaction mixture is quickly reduced to 130 °C and the reaction product formed by heating components II under reflux for 3 h at a temperature of 135 °C is added. Components III are then added and the reaction temperature is gradually increased to 230 °C with azeotropic distillation of the reaction water and xylene. The esterification is terminated when the acid number of the reaction mixture drops below 2 mg KOH/g, when the conversion of carboxyl groups exceeds 99%. The reaction product is cooled to 120 °C, diluted by adding 77 parts by weight of xylene and further cooled to 80 °C. At this temperature, 37.86 parts by weight of xylene are added evenly over 10 minutes. parts of 2,4-toluene diisocyanate and then the reaction mixture is diluted with 166 parts by weight of xylene. The urethanization of the alkyd takes place at 80 °C and is terminated when the content of free groups -17=0=0 drops below 0.2 wt. % by adding 10 parts by weight of n-butyl alcohol and heating for 1/2 hour at 80 °C. Kon11

233 154 versions of isocyanate groups at the end of urethanization are

30.5%.

Alkyd is diluted with a mixture of xylene and butanol in a mass ratio

19 : 1 for a solution containing 50% by weight of non-volatile components. Paint film binder without additive siccatives dry up to level 1 10 minutes level 2 1 hour level 4 3 hours and in the interval of 1 to 24 hours it is perfectly recoatable with paints nitrocellulose-based materials. Example 2 Components I mass parts xylene solution of polymer alcohol B containing 55% by weight of non-volatile components 419.70 phthalic anhydride 19.39 Components II of linseed oil acid 153.93 phthalic anhydride 134.53 benzoic acid - 41.05 glycerol 115.44 pentaerythritol 38.48 Ingredients III dehydrated castor oil acids 38.48

Components I are weighed into the reactor and the reaction mixture is heated with stirring until xylene begins to distill. After distilling approximately 140 to 150 parts by weight of xylene, the temperature in the reactor rises to 180 °C and is left to react at this temperature for 1 hour under reflux. The reaction product is cooled

233 154 to 140 °C and components II are gradually added to the reactor.

With the introduction of an inert gas and stirring, the reactor contents are gradually heated to 245 °C. The esterification water is removed from the reaction mixture by azeotropic distillation with xylene from the polymer alcohol. When the acid number of the reaction mixture falls below 15 mg KOH/g, the temperature is reduced to 230 °C and component III is introduced into the reactor. At this temperature, esterification is carried out to a conversion of carboxyl groups of at least 99.4%, when the acid number of the reaction mixture falls below 1.3 mg KOH/g.

The reaction product is cooled to 120 °C, diluted with 82 parts by weight of xylene and the resulting solution is cooled to 70 °C. At this temperature, the alkyd is urethaneized with 33.99 parts by weight of 2,4 toluene diisocyanate, which is added evenly over 30 minutes. After another 30 minutes after the addition of the isocyanate, the reaction mixture is diluted with 176 parts by weight of a mixture of xylene and white spirit (in a weight ratio of 3:1) and allowed to react at 80 °C until the free isocyanate groups drop below 0.15% by weight, i.e. to a conversion exceeding 91.5%. Unreacted isocyanate groups are removed by adding 10 parts by weight of isobutyl alcohol and heating ^for 50 to 60 minutes at 80 °C. The resulting product is diluted to a 50% solution with a mixture of xylene and n-butyl alcohol (10:1 by weight).

The paint film of the binder dries to: stage 1 in 15 to 18 minutes stage 2 in 1 to 1 1/2 hours stage 5 in 8 to 10 hours

Example 3

Components I parts by weight polymer alcohol D 237.66 (xylene solution with a dry matter content of 45% by weight) polymer alcohol A 291.73 (xylene solution with a dry matter content of 55% by weight) phthalic anhydride 139.04

233 154

Components II soybean oil acids 106.96 of dehydrated ricin acid oils 32.09 p-tert.butylbenzoic acid 32.09 pentaerythritol 26.74 glycerol 106.96

Components I are weighed into the reactor and xylene is distilled off from the reaction mixture until a temperature of 165 °C is reached. At this temperature, it is heated for 1 1/2 hours, then cooled to 100 to 120 °C and components II are gradually added. While supplying inert gas, the temperature is gradually increased to 230 to 240 °C and the resulting water of reaction is azeotropically distilled. The course of the reaction is monitored by the acid number and the esterification is terminated at an acid number of 1 to 2 mg KOH/g and the reaction mixture is cooled to 100 to 135 °C. 120 parts by weight of a mixture of xylene and white spirit (5 : 1 part by weight) are added and after homogenization, the temperature of the solution is reduced to 75 °C. At this temperature, 26.74 parts by weight of parts of 1,6 hexamethylene diisocyanate and after 30 to 45 minutes of reaction the solution is diluted with 115 parts by weight of xylene. At 75 to 85 °C the reaction mixture is left under stirring until the content of unreacted isocyanate groups is reduced to below 0.11% by weight and the conversion of -N=C=0 groups is 92%. The unreacted isocyanate groups are bound by adding 11 parts by weight of n-butyl alcohol and heating for 45 minutes at 80 °C. The finished product is diluted with xylene or a mixture of xylene and butanol in a weight ratio of 15 to 2 to a solution containing 55% by weight of non-volatile components.

A film of alkyd binder with a thickness of 35 µm dries to:

grade 1 in 10 to 15 minutes grade 2 in 60 to 70 minutes grade 5 in 8 hours.

In the interval of 1 to 24 hours after application, the films can be overcoated with nitrocellulose-based coatings. Sikati14

233 1S4 by adding 0.06% by weight of Co in the form of octoate, the drying time to the 2nd and 5th stages is shortened by 10 to 15%.

Example 4

Ingredients I parts by weight linseed oil 374.98 glycerol 99»99 lead oxide 0.058

Components II polymer alcohol C 333.31 (50% xylene solution) tetrahydrophthalic anhydride 149.99

The reactants I are heated in a reactor in an inert atmosphere with stirring to a temperature of 250 °C and heated at this temperature until the maximum compatibility of the reaction mixture with methyl alcohol is reached. The reaction mixture is cooled to 100 to 140 °C and the acid ester of the polymer alcohol C, prepared by heating the components II under reflux for 1 1/2 hours at 150 ^° C, is added to the equilibrium mixture of hydroxyesters in the reactor. The reaction temperature is increased to 235 °C and the water of esterification is distilled off azeotropically with xylene from the polymer alcohol. After a conversion of more than 99% is achieved at an acid number of 1 to 3 mg KOH/g, the reaction is terminated, the reaction mixture is cooled to 100 to 120 °C and diluted with 86 parts by weight of xylene. The alkyd solution is urethaneized at 100 °C by dropwise addition of 41.66 parts by weight of isophorone diisocyanate, added to the reaction mixture over a period of 30 to 45 minutes. After 30 minutes from the end of the dropwise addition, the solution is diluted with 186 parts by weight of xylene and allowed to react at 85 °C until the content of isocyanate groups decreases to 0.11% by weight (conversion of -N«Ce0 is 98.9%).

Unreacted isocyanates are blocked by adding 15 parts by weight of isobutyl alcohol and heating for 20 to 40 minutes at 80 °C.

233 154 groups. The alkyd solution is diluted with xylene to a solution containing 50% by weight of non-volatile components,

The binder coating film dries without the addition of metal driers to:

level 1 10 to 13 minutes level 2 70 to 80 minutes level 5 9 to 12 hours.

Example 5

Components I mass parts polymer alcohol E 365.56 (58% xylene solution) phthalic anhydride 55.13 Components II soybean oil acids 237.49 dehydrated castor acid ole- It is 59.37 phthalic anhydride 46.65 benzoic acid 59.37 ethylene glycol 33.93 pentaerythritol 93.30 neopentyl glycol 16.96

The components I are gradually introduced into the reactor with stirring and heated, distilling off about 60% by weight of the xylene contained in the polymer alcohol solution. The reaction mixture is heated for 3 h at 160 °C, then cooled to 130 °C and, with the supply of inert gas and constant stirring, the components II are gradually added. The reaction mixture is heated to a temperature of 210 °C, which after 1 h of esterification is further increased to 230 °C. The esterification water _is removed from the reactor by azeotropic distillation with the xylene contained in the copolymer alcohol E. The esterification phase of the alkyd preparation is terminated when the conversion of the carboxyl shells is above 95%, i.e.

233 154 when the acid number drops below 2 mg KOH/g. The reaction product is cooled to HO °C, diluted with 136 parts by weight of xylene and the alkyd solution, after cooling to 75 ,°C, is urethaneized by dropwise addition of 32.23 parts by weight of 2,4-toluene diisocyanate within 20 to 40 minutes. After dropwise addition, the reaction mixture is heated for 1 h and then diluted

402 parts by weight of xylene. The reaction mixture is heated for 1 h at 80 °C and then at 110 °C until the content of free isocyanate groups drops below 0.06% by weight. The remaining isocyanate groups are blocked by adding 17 parts by weight of n-butyl alcohol and heating for 20 minutes at 100 °C. The alkyd resin solution is diluted with a mixture of xylene and white spirit in a weight ratio of 90 : 10 to a solution with a dry matter content of 50% by weight.

An alkyd varnish film with a thickness of 30 to 35 µm has a non-stick surface up to stage 1 in 15 to 20 minutes up to stage 2 in 60 to 80 minutes up to stage 5 in 30 hours

Pilray resists the effects of aggressive solvents (esters) within 1 to 48 hours after application.

Example 6

Ingredients I parts by weight linseed oil 200 soybean oil 79.06 glycerol 54.26 trimethylolpropane 31.01 neopentyl glycol 15.50 lead oxide 0.043

Components II polymer alcohol A 434.09 (50% xylene solution) phthalic anhydride 77.52

Components III benzoic acid 38.76 *** adipic acid 38.76

In the reactor, the components I are gradually mixed and heated to 250 °C under the supply of inert gas. After 1 h after heating, the miscibility of the reaction mixture with methyl alcohol is monitored and the alcoholysis is terminated when maximum miscibility is achieved. Then the mixture is cooled to 140 °C.

Simultaneously with the alcoholysis, the acid ester is prepared by heating components II for 1/2 h at 180 °C. The resulting product is cooled to 140 °C and, after mixing with the oil alcoholyzate and components III, the reaction water is removed from the reaction mixture by azeotropic distillation with xylene from the polymer alcohol. After esterification of more than 99.5% of the carboxyl groups, the acid number drops below 1 mg KOH/g and the reaction is terminated by cooling to 140 °C®. The product is, after dilution with 81 parts by weight of xylene, urethaneized by adding 31.01 parts by weight of 2,4 toluene diisocyanate dropwise over 15 minutes at a temperature of 80 to 85 °C. Immediately after the dropwise addition, the reaction mixture is diluted with 171 parts by weight of xylene and the urethaneization is completed by heating the reaction mixture until the conversion of isocyanate groups is 96%.

After reaching 0.08 wt. % of -N=C=0 groups, 15 wt. parts of n-butanol are added and the unreacted isocyanate groups are blocked by heating for 20 minutes at 90 °C. The alkyd is diluted with a mixture of xylene and butanol (19:1 wt. parts) to a solution with a dry matter content of 50 wt. %.

An unpigmented paint film with a thickness of 30 to 35 μm without siccatives dries in: grade 1 20 to 25 minutes grade 2 90 minutes grade 5 48 hours.

Claims (2)

1. Alkyd resins based on the reaction products of carboxylic acids, polyhydric alcohols and isocyanates or substitution or functional derivatives of these components, characterized in that from the total amount of hydroxyl groups present in the starting reactants, they contain 10 to 35% of hydroxyl groups free, 11% of hydroxyl groups bound after reaction with isocyanates, in particular by -IH-COO- bond and 50 to 85% ester-linked hydroxyl groups, of which from 15 to 65% by weight of the total polyhydric alcohols are acyclic alcohols having 2 to 5 carbon atoms and 2 % to 4 hydroxyl groups and 35 to 85 wt. polymeric alcohols prepared by the free-radical copolymerization of β mole of styrenes with 0.35 to 1.70 mole of esters derived from acrylic or methacrylic acid and acyclic monovalent alcohols having carbon numbers of 1 to 4, 0.02 to 0.30 mole of hydroxy esters derived from these acids acyclic and dihydric alcohols of carbon number 1 to 4 and optionally up to 0.10 moles of acyclic unsaturated monocarboxylic acids of carbon number 13 to 22 and an iodine number 120-200 g _J2 / 100g. 2. A process for preparing the alkyd resins according to claim 1, characterized in that 300 to 550 parts by weight of ¹ · 40 to 60% alcohol solution of the polymer in organic solvents, preferably xylene are reacted at 130 to 180 ° C for 0 5 to 3 hours with 15 to 160 wt. parts by weight of cyclic dicarboxylic acid anhydride having a carbon number of 8 to 10, then 10 to 500 wt. parts of acyclic monocarboxylic acids having a carbon number of 13 to 22 and / or their hydroxy esters derived from acyclic alcohols are 233 154 2 to 4 hydroxyl groups and 2 to 5 carbon atoms and optionally up to 200 wt. parts by weight of monocarboxylic and / or dicarboxylic acids having a carbon number of 6 to 10 and up to 160 wt. parts of acyclic alcohols having 2 to 4 hydroxyl groups and 2 to 5 carbon atoms, the mixture is heated to a temperature of 220 to 250 ° C, reacted by gradually distilling off xylene and reaction water until the acid number of the reaction mixture falls below 5, preferably below 2 mg KOH / g, then the product is cooled to 80-110 ° C and reacted with 10-50 wt. parts of the diisocyanate having a carbon number of 9 to 12, wherein at any stage of the reaction, the reaction mixture is diluted with 200 to 550 wt. parts of xylene and / or white spirit, after the conversion of the isocyanate groups to at least 90%, the resin preparation is terminated by the addition of 5 to 25 wt. parts of n-butyl alcohol and / or isobutyl alcohol.