DE1924577A1 - Process for the multi-stage production of acid-modified polyester hair from low molecular weight polymers - Google Patents

Description

REICHHOLD ALBERT CHENIB AQ, HANBURO 13, IVERSSTRASSE 57 Patent application

Process for the multi-stage production of acid-modified polyester resins from low molecular weight polymers

The invention relates to a process for the multistage production of polyester resins by reacting low molecular weight polymers containing carboxyl groups, preferably telomers, with a) polyhydric alcohols, b) monobasic organic acids and c) a monoepoxy compound. The expression "carboxyl groups ¹ *" used here and below also includes carboxylic acid anhydride groups.

As is already known * one can based on polyester resins manufacture of low-molecular-weight copolymers containing carboxylic acid anhydride groups by mixed esterification with longer-chain fatty acids with up to 20 carbon atoms and polyhydric alcohols » the use as air-drying or thermosetting laok binders Find. As copolymers containing carboxylic acid anhydride mostly mixed polymer · of maleic anhydride with vinyl aromatic hydrocarbons used, according to known Process at elevated temperature with elimination of water. Polyesters are implemented «

However, there is a major disadvantage of these known methods in that undesired bonds often occur during polyester formation, which lead to products which are practically unusable. This is due to the high acid functionality of the copolymers, e.g. due to a high content of free carboxyl or carboxylic anhydride groups. A complete esterification is therefore not possible due to the premature quelling. To gel-free To produce polycondensates, the esterification has to be carried out at high levels Residual acid numbers, for example over 40, are canceled.

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Polyesters obtained in this way have a long shelf life because of their high acid number. You can due to their high acidity sur curing at elevated temperature only with relatively low-reactive curable synthetic resins, s.B, melamine resins, such as kexamethoxymethylmelamine or epoxy resins, see.B based on epichlorohydrin and diphenylolalkanes, in particular diphenylolpropane, optionally also in aqueous Solution, to be combined · Therefore high stoving temperatures are required for complete curing. For air-drying Paint binders are highly stable for reasons of compatibility with certain pigments, such as zinc white, entirely undesirable; The high acid content causes the formation of zinc soaps from the zinc oxide, which leads to increasing thickening of the resin occurs. The polycondensates described with a high residual acid number are therefore used for the production of air-drying paints not suitable.

Complete esterification down to residual acid numbers of 5 to 25 » As is the case with thermosetting and air-drying ones, for example Alkyd harsen are desired can only be achieved by the known processes without premature curing if the Proportion of acid bsw. Anhydride groups in the copolymers used, which contain the acid anhydride, are kept low will. For example, only copolymers of vinyl aromatic hydrocarbons with maleic anhydride can be used whose maleic anhydride content is not 20% by weight exceeds «For the production of low molecular weight copolymers with low maleic acid hydride contents are again very Complicated procedures are necessary, since maleic acid is preferred in proportion to vinyl aromatic hydrocarbons! " the means to mixed polymers with high acid functionality, mixed »polymerized *

Another Naohteil of the known methods is that reacts existing carboxylic acid anhydride with the polyhydric alcohols under formation of pus in the normal manner at Polyesterharsen reaction conditions "for example, at 180-260 ⁰ C, only a small portion. The minor part of the responsive

For groups, «Herding · sur gel formation can be sufficient, as before

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• BAD ORIGINAL ^{/ 3}

has been described. As a result of the unfavorable spatial arrangement in the molecule of low molecular weight polymers, ' a large part of the anhydride groups unchanged. On the other hand, under the reaction conditions, ester bonds that have already been formed are converted back to the more stable anhydrides. It is therefore It is entirely possible that larger amounts of the low molecular weight polymers are not chemically incorporated into the polyester resins at all, but rather are present unaltered alongside them in a physical mixture. Larger proportions of not previously bound polymers in the finished polyester resins or the Paints and coatings produced by them are, however, resistant to chemicals due to poor compatibility and daily stability not desired. The aim was therefore to use low molecular weight polymers containing carboxyl and / or carboxylic acid anhydride groups to produce gel-free fatty acid-modified polyester resins with acid numbers below 25 in which the polymers are completely chemically incorporated into the polyester assembly.

It has now been found that these requirements are met in a simple manner according to the invention in that in the first stage the carboxyl groups of the polymers reacted in the presence of the polyhydric alcohols a) and the monoepoxide compound c) are, whereupon in the second stage the reaction products are reacted with the acids b) and with polycarboxylic acids d) "or that in the reaction in the first stage instead of the polyhydric alcohols a) reaction products from the polyhydric alcohols a) and the monobasic organic acids b) are used, the reaction products having an acid number of less than 5 have and the reaction in the second stage takes place only with the polycarboxylic acids d), and that the products thus obtained in third stage are hardened. Under "polycarboxylic acids" are hereinafter also to be understood as meaning their anhydrides. Surprisingly, in the first stage, under relatively mild conditions, intermediate products practically free of carboxyl, carboxylic and acid anhydride groups.

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The reaction of the low molecular weight polymers with the monoepoxy compound and the polyhydric alcohols can take place in the melt or in a solution of an inert solvent at elevated temperature, for example at 80-15O ⁰ C, optionally using a catalyst. Normally, the polymer is mixed with the polyhydric alcohol or a mixture of polyhydric alcohols and optionally the catalyst with the solvent to form solutions with 60 to 95 % solids content and the monoepoxy compound at 80 to 200 ° C, preferably at 80 to 140 ° C, this mixture gradually admitted. The reaction mixture is then kept at these temperatures for some time until practically no more carboxyl groups can be detected analytically, for example by titration of the acid number or by infrared spectroscopy. The acid number of the reaction products in the first stage is set to values from 0 to 5 and the hydroxyl number to around 50 to 500, if possible.

Monoepoxide compounds suitable for this reaction are, for example, alkylene oxides, such as ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, aliphatic monoglycidyl ethers, for example ethyl glycidyl ethers and allyl glycidyl ethers, aliphatic monoglyeidyl ethers, and epoxy-epoxy acids with C12-olefin, epoxy-epoxydes with C12-olefin-chain bis-epoxylic acid, such as glycidyl esters of branched-chain 8yd-chain bis-olefins preferably 8 to 12 carbon atoms and styrene oxide. The alkylene oxides with up to ¹ I carbon atoms, such as propylene oxide or monoglyeidyl ester aliphatic monocarboxylic acids with up to 12 carbon atoms, are preferably used. The monoepoxide compounds can be used alone or in admixture. These monoepoxides are preferably used in a ratio of 0.2 to 3, preferably 0.8 to 2, epoxy groups per mole of free carboxy groups, the ratio per mole of carboxylic acid anhydride group being doubled.

As inert solvents for this reaction are s "B, and aliphatic hydrocarbons »esters and ketones, such as Toluene, xylene, heptane, cyclohexane, benzene mixtures, butylaoefeat " Called acetone and methyliaobutyl ketone.

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Suitable® catalysts are tertiary ηηά / ού®ΐ 'q aliphatic® or aromatic © Aroine _s wi® Trilfciiylsuin, n ^ Dodeeyltrira®thylagsiEoniiimchlorid ₅ Di & ethylardlin _s Älkylaasin-substituted phenols, like 2,4 /> - Tris- (di! 3 © $ hylamino) - »phenol, Borfluoriö-amine adduct · ; such as piperidine-BortH.fluoH.d üddukt-substituted acid amides © »as dimethylformamide» Alkalisalg "of alcohols and inorganic and organic acids * ^ ₆ B * Ifatriuamefchylat, laliiimmethylat, lithium chloride, sodium chloride LithiumbSOsai d _s, sodium acetate, Kaliumbenaoat, or the like Natriumbensoat , in each case alone or in a mixture with one another . They are expediently used in an amount of 0.01 to 0.1 mol per mol of mono-epoxy compound.

ι As polyhydric alcohols, di © as additional components for the Reaction according to the invention are necessary, are divalent Alcohols such as ethylene glycol »1,2-propanediol, 1,3-propanediol, 1,3-butanediol »butanediol-1, ^ 2,2-dimethylpropanediol-1,3 and Diethylene glycol or higher alcohols, such as trimethylolpropane, trimethylolethane, glycerol and pentaerythritol. Mixtures of dihydric and higher alcohols, such as ethylene glycol with trimethylolpropane or diethylene glycol with pentaerythritol can be used. The use of alcohols with more than two functional groups allows the production of polycondensates with higher viscosity. The multi-valued ones Alcohols are used in amounts of 4 to 8 hydroxyl groups per mole of carboxyl group of the low molecular weight polymers, whereby the ratio per mole of carboxylic acid anhydride group is to be doubled accordingly »

The polymers containing carboxyl and / or carboxylic acid anhydride used as starting materials expediently have a Average Molgewioht between 400 and 3000 preferably between 600 and 2500 and have an average of between 0.08 and 1.5 carboxyl groups or a corresponding number of carboxylic acid anhydride groups, each based on 100 units of molecular weight However, the number of carboxyl groups should not be 1.5 be crossed, be exceeded, be passed. The polymers mentioned can be obtained by telomerizing olefins, preferably monoolefins, with 2 bits

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6 1

. 9 C atoms! Monomeric "such as ethylene, propylene, butylene and Oeten or substituted olefins, Viny such as styrene" aM®tfayl ° etyrol, derivatives of acrylic or methacrylic $ ζ · Β · Aeren Eetern. Amides, nitriles, vinyl pyridine, vinyl pyrrolidone; with monomers containing carboxyl or carbonic acid anhydride groups, such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride or maleic acid half-esters with monohydric alcohols. Telomers, which mainly consist of building blocks containing carboxyl groups, can also be used as common products. Preferably, such olefin ₈ are in particular styrene-Maleinsöureanhydrid telomers used, the quantity ratio of maleic anhydride; ISQ styrene, 5 to ₈ Ir2O preferably 1: 8: 1 to. 1 The following telomers may be mentioned as examples of suitable starting materials; 1) those made from styrene and maleic anhydride (molar ratio 1: 1, 2: 1, 3: 1, 5il _e 8: 1), 2) those made from octene and maleic anhydride (molar ratio 1: 1), 3) those made from styrene and acrylic acid ( 1: 2), wherein the preferably mentioned under 1) and 2) are used lsi molar ratio) and ¹ O those of styrene, a-methylstyrene and maleic anhydride (molar ratio of the first

The telomeres normally contain telogens built into the molecule, which act as chain carriers in the production of the telomeres, but which do not influence the production of the polycondensates. These telogens, for example, cumene _s xylene, chloroform or Diisobuty! Ketone.

The reaction in the second stage is generally carried out according to known methods of SiOH ,, preferably at elevated temperature, "wipe 150 and 25O ⁰ C. The liberated during this esterification reaction, water may be distilled off directly or by means of a Sohleppmittele such as benzene, xylene or toluene, azeotropically over »distilled. To shorten the reaction time, esterification catalysts, such as p-toluenesulfonic acid, phosphorus. acid, hydrochloric acid or sulfuric acid, can be soldered in small quantities »The esterification is carried out in two strengths up to an acid number of 5 bit 30, preferably 8 to 25» with the formation of acid-modified polyester resins. The OH / COOH group ratio in the finished end product should normally be divided between 1.8: 1 and 1.1: 1. Duron this final acid steel

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and the OH / COQH group ratio can be important in terms of application technology Properties such as reactivity during curing, compatibility with other synthetic resins and pigments as well the wetting of pigments. Preferably the intermediate products are first reacted with the monobasic organic acid to an acid number below 5 and then esterified only with the polycarboxylic acid component to the desired final acid number and viscosity. But it can also be in reverse order or with simultaneous implementation.

As a monobasic organic acids b) are used are saturated and / or olefinically unsaturated 5auren £ ^e with 2d ^ s ^@ §5j preferably 4 to 18 carbon atoms. The type and amount of these fatty acids can be used in a known manner to influence essential application properties, such as flexibility, drying properties, resistance to yellowing, pigment wetting, hardness, etc., of the cured end products. Suitable acids are, for example, fatty acids such as isononanoic acid, Coeos- "fractionated fatty acids, soybean oil fatty acids ₈ linseed oil fatty acids," linoleic acid, ricinene fatty acid, Baumwollsamenölfettsäiir ©, Paimitinsäurej further benzoic acid, phenylacetic acid or the like "These fatty acids can be used each alone or in a mixture. The content of the acids b) in the final product may be from 5 to 70 weight-I, preferably 10 to 60 weight Ϊ, based on the solvent-free Hara _s betragene

In addition to the monobasic organic acids polycarboxylic acids and / or their anhydrides * Examples are adipic acid, phthalic anhydride, maleic anhydride, phthalic acid, maleic acid, isophthalic acid, terephthalic acid, _t, tri- or Pyroraellitsäure and sebacic acid. The amount of polycarboxylic acids which may be used in mixtures _s depends on application points, such as viscosity and Härtungereaktivität and hardness and flexibility of the paint films. The amount is also limited by the hydroxyl groups still remaining after esterification with acid b).

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In carrying out the invention, according to the reaction products are used from the polyhydric alcohols a) and the monobasic organic acids b), the molar ratio is generally chosen so that free hydroxyl groups are still present in the product. In the presence of this hydroxyl-containing acid ester is now how beforehand the reaction of the telomers with a monoepoxide compound carried out, which proceeds in the same good way. In conclusion is further esterified with a polycarboxylic acid. For the proportions of the individual components used, those previously apply described conditions.

After completion of the esterification reaction, the polyester resins are w in a solvent, preferably to 50, dissolved to 70 iigen solutions. Suitable solvents are aromatic and aliphatic hydrocarbons, such as xylene, and gasoline mixtures, alcohols such as butanol, isobutanol and esters, ethers and ketones *, which are used in each case or mixed with one another.

The curing in the third stage can be carried out for example by addition of curable synthetic resins, at elevated temperature, for example at 80 to 25O ⁰ C, preferably from 100 to l80 ° C according to the invention, said coating technology particularly valuable products are formed. In the case of polyester resins, which were produced with the use of drying fatty acids, this addition can be omitted. In this case, small amounts of dry matter (siccatives), for example octoates and / or naphthenates of lead, zinc, manganese, cobalt or the like, are expediently used in a known manner Added support for oxidative drying. Curable synthetic resins are, for example, amine resins, in particular highly reactive, preferably melamine and urea-formaldehyde resins, but also ammeline, guanidine, dicyandiamide, benzoguanamine and other amine-formaldehyde resins or their hardenable etherification products with monohydric alcohols, preferably those with 1 up to 8 carbon atoms such as hexamethoxymethylmelamine butylated melamine resin or the like, including epoxy resins on their own or preferably in combination with

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BATH

Amine resins are suitable »Instead of Aminh & rz®n is also the Use of curable phenolic resins or self-retaining! * Acrylic resins possible. The amount of the hardenable resin added is im generally 5 to 50 g by weight, based on the solids.

The inventively prepared, cured products can mainly ale coating on HOII, metal as a base for molding and other molding compounds and as moldings are ₉ paper and textiles as well as binders for paint, "as intermediate layers in laminates, as adhesives, casting resins * use.

The application properties of the end products produced according to the invention can be modified by adding other known ones Resins, e.g., phenolic resins, preferably resoles, alkyd resins, acrylic resins or the like, can be modified. Possibly acidic substances can also be added as curing catalysts, e.g. phthalic acid, maleic acid half-esters, p-toluenesulphonic acid, phosphoric acid or their acidic ethers, e.g. phosphoric acid monobutyl ester or the like, and also fillers, e.g. Barite, zinc oxide and / or pigments, wis titanium dioxide, zinc sulfide, phthalocyanine blue or red, without any undesirable effects Thickenings occur * The proportion of curing catalysts can be 0.05 to 2 weight percent, based on the amount of solids be. The cured end products obtained according to the invention exhibit good elasticity, high hardness, good compatibility with pigments and good chemical resistance to fats, organic Solvents, water and corrosive agents. They also have good adhesion to the base *

example 1

The following components are combined in a three-necked flask with stirrer, C0 ₂ inlet tube and reflux condenser: 730 g of styrene-maleic anhydride telomerizate (molar ratio 8: 1, molecular weight 2000), 120 g of trimethylolpropane, 103 g of propylene glycol, 200 g of xylene and 1, 5 g triethylamine. Under CO ₂ - introductory the mixture to I ^{1 0} C IO is heated, and 60 g of propylene oxide are added gradually within 30 minutes. The mixture is then heated below for a further 4 hours to the boiling point

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Reflux until the acid number has dropped below 5. IR spectroscopy can no longer contain any acid anhydride in the reaction mixture. Subsequently, 250 g of linoleic acid are added "The mixture is esterified by switching on a water separator for 4 hours at 22O ⁰ C until reaching an acid number of less than 5." In this case, most of the Xylol® is distilled off and only a small part as an entraining agent for the Water separation with recycling of the solvent ("circulation distillation") is used. After cooling to 170 ^° C., 78 g of phthalic anhydride and 15 g of maleic acid are added. "At 190 ^° C., the mixture is further esterified up to an acid number of 10 to 12" By dissolving the clear, light yellow resin that is formed in xylene-butanol (10: 1) a 60 solution with a viscosity of 3000 cp at 20 ^° C. is obtained,

This product is mixed in a weight ratio of HarsssMelaminharz & 75:25 with a melamine form & idehyde resin etherified with butanol (from 1 mol of melamine and about 6 mol of condensed formaldehyde), pigmented in the usual way 100% with titanium dioxide and after spraying onto steel sheet with a layer thickness of 40 y (in the dry state) stoved for 30 minutes at 120 ^° C. A pure white, high-gloss film of high hardness and good flexibility and adhesion results.

Example 2

In a three-necked flask with stirrer, C0 ₂ -Qa8einleit "ngsrohr and water separator with a reflux condenser 120 g of trimethylolpropane with 250 g of linoleic acid in 2 ¹ JO be esterified ⁰ C until an acid number below. 4 After cooling, 730 g of styrene-maleic anhydride telomerizate (molar ratio 8: 1, molecular weight 2000), 103 g of propylene glycol, 200 g of xylene and 1.5 g of triethylamine are added and 60 g of propylene oxide are metered ^{in at I 1} JO ^{0 C.} Within 4 hours at 120 to 140 ⁰ C under reflux, the acid number drops below values. 5 Then the water separator is connected again and the esterification with 115 g of phthalic anhydride and 25 g of maleic anhydride at 170 to 18O ⁰ C carried out up to an acid number of 14 to 16, wherein the major part is removed by distillation of the xylenes. The end product becomes a 60%

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Solution prepared in a xylene-isobutanol mixture (10: 1). Their viscosity is 1200 ep (20 ^° C.). The product becomes a. white stoving enamel as produced in example 1. After baking, a very hard and resistant film with valuable paint-like properties is also obtained here.

Example 3

The following components are combined in an apparatus according to Example 1: 300 g of styrene-maleic anhydride telomerizate (molar ratio 3: If molar weight 1500), 90 g of 2,2-dimethylpropanediol-1,3, 85 g of ethylene glycol, 200 g of xylene and 1,2 g sodium benzoate. At 1 * 40 ° 0, the mixture is mixed with 60 g of propylene oxide as in Example 2 and reacted at this temperature to an acid number below 5. After connecting a Wasserabsoheiders 250 g linoleic acid, 73 g of adipic acid and 10 g of maleic anhydride are added and the further esterification carried out as in Example 2 at 180 to 2-20 ⁰ C until an acid number of 10 to 12 Produced a 60 Zige solution having a viscosity of 2500 ep (20 ⁰ C): is obtained from the resulting resin in xylene-butanol (10: 1).

As described in Example 1, it becomes a white stoving enamel made, which is characterized by high hardness and good chemical resistance.

example k

The procedure is as in Example 1. Instead of linoleic acid, however, 250 g of ricineal fatty acid are used.

The resulting 60 Jige polyester resin solution in xylene has at 20 ° C a viscosity of "approx. 3000 cp.

The technical properties of the lacquer obtained as in Example 1 Stoving enamel films are excellent. The films show excellent adhesion to the substrate.

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Example 5

The following components are combined in a device according to Example 1: 190 g of styrene-maleic anhydride telomerizate (molar ratio 1: 1, molecular weight 800), 135 g of trimethylolethane, 120 g of 1,4-butanediol, 200 g of xylene and 1.5 g of lithium chloride. At liJO ° C 70 g of propylene oxide are gradually added and the reaction is continued at 120 to 140 ° C. until an acid number of 3 to 5 is reached. After connecting a water separator, 250 g of ricineal fatty acid are added and the mixture is heated to 250.degree Esterified to the acid number 3 to 5. Finally, it is reacted with 90 g of phthalic anhydride at 180 ° C., the viscosity to 1000 cp (50 iig in xylene) increases. The end product becomes a 60% solution in xylene-isobutanol (4: 1) prepared. the Acid number (based on plague resin) is 15 to 18.

As described in Example 1, this product is used to produce a white stoving enamel, which is excellent in lacquer engineering Properties, especially with regard to hardness, elasticity, adhesion and chemical resistance.

Example 6

In an apparatus as in Example 1, 750 g of octene-maleic anhydride telomerizate (molar ratio 1: 1, molecular weight 1000), 83 g of glycerol, 1 ^ 3 g of diethylene glycol, 200 g of xylene and 1.5 g of triethylamine are mixed and mixed to IiIO ⁰ C- heated. 60 g of propylene oxide are gradually added over the course of 30 minutes and the reaction mixture is kept at reflux temperature until the acid number has fallen below 5. After connecting a water the mixture with 250 g of ricinene fatty acid and 150 g of adipic acid is esterified at 200 ⁰ C. The resulting resin is dissolved 60% in xylene. The viscosity of this solution is 3500 cp, the acid number is 15 (based on plague resin). According to Example 1, a white lacquer is produced from this resin in combination with a melamine resin with a weight ratio of 60: 1 | 0 (resin: melamine resin) and titanium dioxide, which is baked at 120 ° C for 30 minutes after being applied to sheet metal. A high-gloss, hard and elastic paint film is created.

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Example 7

142 g of isononanoic acid are esterified with 83 g of glycerol under CO ₂ protection at 220 ⁰ C until an acid number of 3 to 5 In an apparatus according to Example 1, 730 g of styrene-maleic anhydride telomerate (molar ratio 8: 1, molecular weight 2000), 122 g of 1,4-butanediol, 200 g of xylene and 0.8 g of sodium methylate are then added to this ester and at 130 to 140 ° C. 75 g of propylene oxide were added dropwise over the course of 30 minutes . The reaction is completed to an acid number of about 3 by refluxing for several hours. After connecting a water separator, 70 g of phthalic anhydride and 20 g of adipic acid are added and the mixture is ^{esterified at 200 °} C. up to an acid number of about 18. The resulting resin is dissolved 60% in xylene isophorone (20: 1). The viscosity is 3600 cp (20 ° C). After mixing with a meiamin-formaldehyde resin, as in Example 1 in the resin: melamine resin weight ratio = 75:25, pigmentation with titanium dioxide and stoving for 30 minutes at 120 ° C, an extremely flexible and hard lacquer film with good resistance to dyes and fats is formed Substances such as lipstick or shoe polish.

Example 8

450 g of styrene-maleic anhydride telomerizate (molar ratio 5: 1, molecular weight 1900) are in a device according to Example 1 with 240 g of trimethylolpropane, 200 g of xylene, 2 g of sodium benzoate and 65 g of propylene oxide at 130 to 140 ° C up to an acid number of implemented under 5. Using a water separator, esterification is then carried out with 650 g of soybean oil fatty acid and 75 g of phthalic anhydride at 210 to 220 ° C. to an acid number of 5 to 10. The resulting light-colored, clear resin is dissolved in 60% petrol-xylene (6: 4) and then has a viscosity of 1500 cp (20 ° C.). To produce an air-drying white topcoat, the product is pigmented with titanium dioxide, 100 g TiO ₂ per 100 g resin, and treated with siccative substances, for example 0.03 % cobalt naphthenate (based on resin). The film applied to sheet steel dries in a few hours to form a hard, tough, elastic coating.

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Example 9

According to Example 1, 230 g of styrene-maleic anhydride telomerizate (molar ratio 2: 1, molecular weight 1450) with 120 g of trimethylolpropane, 120 g of pentaerythritol, 200 g of xylene, 2.5 g of potassium methylate and 50 g of propylene oxide at 130 ^° C. unset to acid number 3. Under removal of water and with recycling of xylenes used as an entraining agent into the reaction mixture at 220 ⁰ C is then weiterverestert with 470 g of linseed oil fatty acid and 90 g of phthalic anhydride to an acid number of about. 8

The resulting resin is dissolved in 60 μl in petrol-xylene-isobutanol (80:10:10). The viscosity is 2500 ep (20 ^° C.). As described in Example 8, an air-drying lacquer is produced therefrom. The dried paint films are characterized by hardness and hexibility.

Example 10

In the batch of Example 7, the propylene oxide is replaced by 240 g of the glycidate ester of a mixture of aliphatic branched-chain carboxylic acids having 9 to 12 carbon atoms and the entire reaction is carried out in an analogous manner. After dissolving in xylene up to a content of 60 % solid resin, a light-colored, clear resin with a viscosity of 3500 cp and an acid number of 15 is produced. its elasticity compared to that from Example 7 (implementation with Propylene oxide) is significantly increased.

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Claims (13)

Claims 1. Process for the production of polyester resins by multi-stage Reaction of low molecular weight polymers containing carboxyl groups, preferably telomers, with a) polyhydric alcohols, b) monobasic organic acids and c) a monoepoxy compound, characterized in that in the first stage the carboxyl groups of the polymers in the presence of the polyhydric alcohols a) and the monoepoxy compound c) are reacted, whereupon, in the second stage, the reaction products are reacted with the acids b) and with polycarboxylic acids d) or that in the reaction in the first stage instead of the polyhydric alcohols a) reaction products from the polyhydric Alcohols a) and the monobasic organic acids b) can be used, the reaction products having an acid number of less than 5 and the reaction in the second stage takes place only with the polycarboxylic acids d), and that the products thus obtained be hardened in the third stage. 2. The method according to claim 1, characterized in that the reaction in the first stage up to an acid number of 0 to 5 and a hydroxyl number of about 50 to 500 is performed. 3. The method according to claim 1 or 2, characterized in that the reaction in the second stage up to an acid number of 5 to 30, preferably 8 to * 25, and up to a ratio of OH groups: COOH groups of 1.8: 1 to 1.1: 1. 4. Process according to Claims 1 to 3, characterized in that in the second stage the monobasic organic acids b) and the polycarboxylic acids d) in any order or simultaneously be esterified. 009848/1 895 5. Process according to Claims 1 to ¹ J, characterized in that Copolymers with an average molecular weight of 400 to 3,000 are used, optionally telomeres from maleic anhydride and styrene or octene, whose ratio of maleic anhydride to the other monomers is 1: 0.5 to 20, preferably 1: 1 to 1: 8. 6. Process according to Claims 1 to 5, characterized in that copolymers are used which contain 0.08 to 1.5 carboxyl groups per 100 molecular weight units or a corresponding one Contain number of carboxylic anhydride groups. 7. Process according to Claims 1 to 6, characterized in that an alkylene oxide with up to ¹ I carbon atoms or a glycidyl ester of aliphatic carboxylic acids with up to 12 carbon atoms is used as the monoepoxy compound. 8. The method according to claims 1 to 7 »characterized in that the Monoepoxy compound is used in a ratio of 0.2 to 3, preferably 0.8 to 2, epoxy groups per mole of free carboxyl groups. 9. Process according to Claims 1 to 8, characterized in that the polyhydric alcohols a) in a proportion of 4 to 8 hydroxyl groups can be used per mole of carboxyl group of the low molecular weight polymers. 10. The method according to claims 1 to 9, characterized in that saturated and / or olefinically unsaturated fatty acids with up to 25 carbon atoms can be used as component b). 11. The method according to claims 1 to 10, characterized in that component b) is used in such an amount that its proportion in the end product is 5 to 70, preferably 10 to 60, weight Ϊ, based on the solids content. 009848/1895 12. The method according to claims 1 to 11, characterized in that that hardening takes place after the addition of hardenable synthetic resins at an elevated temperature, preferably at 80 to 250.degree. May 13, 1969
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