HU202561B - Process for producing alkid-resines in the presence of catalyst - Google Patents

Abstract

The present invention relates to a process for the preparation of alkyd resins in the presence of a catalyst. Preparation of alkyd resins monocarboxylic acids wherein 50-100% by weight of monocarboxylic acids are either unsaturated fatty acids or partially or fully triglycerides thereof - by condensation of one or more polycarboxylic acids and / or polycarboxylic acids and by condensation of one or more polyalcohols at 160 ° C to 260 ° C and The process is carried out by continuously removing the water from the reaction, which comprises from 0.2 to 1.5% by weight of the epoxidized oil with an epoxy group of 3-12% by weight of the reaction mixture or an alkyl epoxycarboxylic acid formate 2-ethyl. a chelate catalyst prepared from a mixture of hexylglycidyl ether, or pentaerythritol tetraglycidyl ether or neopentyl glycolyl ether and dibutyltin oxide, in which the weight ratio of the components is between 1: 1 and 1: 2, before the reaction mixture is heated or 140; -180 'C after reaching the melt temperature. Scope of the description: 5 pages, without figure EN 202 561 A -1-

Description

The present invention relates to a process for the preparation of alkyd resins in the presence of a catalyst.

Most of the processes known in the lacquer industry are characterized in that so-called modified alkyd resins of various oil lengths are prepared without the use of a catalyst, polycarboxylic acids (eg phthalic acid, maleic acid or their anhydrides) and polyhydric alcohols (eg glycols, glycerol, pentaerythritol). By condensation at ° C.

The free hydroxyl groups of apoliols are mostly esterified or transesterified with unsaturated or partially saturated fatty acids or vegetable oils. (Patton: AlkydResin Technology 1962).

Of the relatively large number of processes described in the relevant literature and patents for catalyzing the synthetic resin reactions in some way, only a few are widely practiced.

As a conclusion of Flory's model reactions on polyesterification (JOCCA, 1972.55.3), he states that the excess of strong acids or diacids used in cooking accelerated polycondensation.

This is understandable as excess acid shifts equilibrium processes towards ester formation, but the retention of acid groups is detrimental to the applicability of the lacquer industry and adversely affects the color and shelf life of the lacquer.

Similarly, the use of an acid catalyst (ptoluenesulfonic acid) is suggested in German Patent No. 1,258,868 and in R. Howink, Chemie und Technologie dér Kunstoffe (1984).

There is also known a process (British Patent No. 906,232) which proposes the catalytic use of cobalt naphthenate or octoate for the preparation of alkyd resins or vinyl copolymers thereof.

Numerous studies have been published based on mathematically verifiable model calculations that recommend adherence to certain optimal ratios of oil to diacid (Lakokras. Mat. 1970,4; 1975,4).

Another method to reduce production time is to increase the production temperature (up to 280 ° C).

However, both the approximation of the acid-alcohol molar ratios to the stoichiometric values and the raising of the reaction temperature, although speeding up the processes, cause considerable difficulty in the final stage of the synthetic resin production because the viscosity increase rate is very high.

The use of various metal oxides to accelerate polycondensation reactions has also long been used.

Antimony, lead, and tin oxides are frequently used (U.S. Patent Nos. 2,715,111 and 3,157,618), but the disadvantage of using these catalysts is that the finished polyester products are often colored.

Although this coloration is a result of certain phosphorus compounds, e.g. it can be reduced by the addition of triphenylphosphite, but the metal oxides, often reduced to the elemental metal, may be finely divided to separate from the condensation melt and give the resin an undesirable coloration.

In our experiments, it was found that if catalytic amounts of epoxidized fatty acids or alkyl-epoxycarboxylic acid esters or glycidyl ethers such as 2-ethylhexylglycidyl ether or neopentylglycol diglycidyl ether or pentaerythritol ether were used in the cooking of alkyd resins. Chelate from dibutyltin oxide is added to the reaction mixture, the polycondensation stage is accelerated, the acid number decreases and, in parallel, the time of viscosity increase is shortened, while discoloration of the resulting resin can be prevented.

The reduction of the production time is mainly due to the so-called. High oil-length alkali resins with high viscosity, i.e., above 50% oil, will result in significant cost savings, as these types also require high temperatures of 230-260 < 0 > C over long production times, sometimes 30-50 hours.

The use of dibutyltin oxide as a catalyst alone has a significant advantage, but has the disadvantage that the resulting resin is discolored, since it does not prevent side reactions but rather promotes them.

However, this side effect can be eliminated and even a shortening of the production time can be observed by forming a chelate of dibutyltin oxide with a certain amount of epoxidized fatty acid or alkyl-epoxycarboxylic acid ester or glycidyl ether in the initial intermediate stage of polycondensation.

According to the invention, one or more polycarboxylic acids, anhydrides or monocarboxylic acids, or mixtures thereof, and one or more polyalcohols, optionally present in the form of a triglyceride at a temperature of 160 to 260 ° C, preferably The reaction is carried out at a temperature of from 200 to 230 ° C while continuously removing water from the reaction.

The process is characterized in that from 0.2 to 1.5% by weight, based on the total weight of the reaction mixture, of an epoxidized oil containing 3 to 12% by weight of an epoxy group, or an alkyl-epoxycarboxylic acid ester or 2-ethylhexylglycidyl. ether, or pentaerythritol tetraglycidyl ether, or a mixture of neopentyl glycol glycidyl ether and dibutyltin oxide, in which the ratio by weight of the components is between 1: 1 and 1: 2, before the reaction mixture is heated or at 140-180 ° C. after reaching the melt temperature.

The oil content of the alkyd resin thus obtained may range from 30 to 80%.

The mixture is condensed at the above temperature range with azeotropic water separation and a known gas flow until the viscosity and acid number reach the required value.

Preferred polyalcohols for use in the process include:

ethylene glycol, propylene glycol, butanediol, hexanediol. dimethyl-1,3-pentanediol, 2-ethyl-1,3-pentanediol, dimethylol-cyclohexane, polyethylene-propylene glycols, glycerol, trimethylol-ethane, trimethylol-propane, hexane-triol, 1,2,4-butanetriol, pentaerythritol, sorbitol, mannitol, dipentaerythritol.

Preferably the polycarboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, hexahydrophthalic acid, endomethylene tetra-2HU 202561A hydrophthalic acid.hexachloro-endomethylene-tetrahydrophthalic acid, maleic acid, fumaric acid, itaconic acid or their anhydric acid, adipic acid, 5

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

Suitable drying or semi-drying oil components are soybean oil, linseed oil, sunflower oil, tall oil, Chinese wood oil, castor oil and dehydrated castor oil and the like. their fatty acids.

Epoxide Compound Catalyst - preferably epoxidized soybean oil, epoxidized linseed oil, epoxidized octyl oleate, or epoxidized alkyl carboxylic acid ester preferably epoxidized di (2-ethylhexyl) tetrahydrophthalate, epoxidized versatic acid oleate, alkalamazunk. 20

The chelate is prepared from a mixture of the epoxy compound and the dibutyltin oxide in a weight ratio of 1: 1 to 1: 2 at 120-150 ° C.

As a catalyst, the chelate thus produced unexpectedly accelerates condensation and promotes the production of a product with a low final acid number which does not show coloration.

It is believed that the presence of the chelating catalyst suppresses the side reactions causing discoloration.

The following examples illustrate the process of the invention.

Example 1

Chelate catalyst is prepared from a mixture of dibutyltin oxide and epoxy compounds by stirring at 130 ° C for 30 minutes.

The quality, quantity ratio and the catalyst designation of the components are given in the table below.

Catalyst Epoxy Compound Epoxy Compound Quantity - Quantity of Dibutyltin Oxide Labeling

THE Epoxidized soybean oil 10 tr 10 tr B epoxidised di (2-ethyl-hexyl) -tetrahidroftalát 10 tr 10 tr C epoxidized linseed oil 10 tr 20hrs D epoxidized octyl oleate 10 tr 10 tr E epoxidized vectic acid octyl ester 10 tr 10 tr F 20-ethyl-hexyl glycidyl ether 10 tr 20hrs G neopentyl glycol diglycidyl ether 10 tr 10 tr H pentaerythritol tetraglycidyl ether 10 tr 10 tr

2960 cm '

To demonstrate the reaction of the epoxidized and dibutyltin oxide to form a chelated compound, the infrared spectra of the parent compounds and the reaction product were investigated. 40

The epoxidized veracic acid ester exhibits a peak characteristic of epoxy groups.

The relative extinction of the epoxy group relative to the alkyl chain is 0.077. 45

In the case of dibutyltin oxide, the peak for carbon tin bonding is 595 cm @ ¹ .

The relative extinction of the carbon tin bond relative to the downstream chain is 0.342.

The mixture of the two compounds is reacted for 30 minutes at 50-130 ° C to measure the relative extinction of the reaction product relative to the alkyl chain.

The presence of a new compound shows that the relative extinction does not increase as expected but decreases to 0.056. 55

The catalysts prepared according to the example are used in the preparation of alkyd resins.

Example 2: parts by weight of soy fatty acid, 20 parts by weight of phthalic anhydride, 4.3 parts by weight of adipic acid, 5.5 parts by weight of benzoic acid, 22 parts by weight of pentaerythritol,

0.2 parts by weight of catalyst A '(epoxy content 8% by weight) were added in the presence of 5 parts by weight of xylene and then heated to 200'C. 65

The temperature of the mixture is maintained at this temperature with inert gas flow and azeotropic water separation.

When the acid number of the mixture drops below 10 mg KOH / g (DIN 53402) and the viscosity of the solution in 50 wt% white spirit reaches 250 s. (DIN 53211.20 ° C), the resin melt is cooled and then 50 wt% white spirit. diluted to%.

The resin solution is preferably used for synthetic air-drying enamel paints.

Example 3

56.3 parts by weight of sunflower oil are heated to 260 ° C and stirred for 30 minutes under inert gas. Then cooled to 200 ° C, 8.0 parts by weight of pentaerythritol and 0.03 parts by weight of lead oxide were added.

Alcoholization is carried out at 245 ° C until the mixture has a positive methanol solubility test (2 hours).

The solution is cooled and 6.1 parts of pentaerythritol, 24.9 parts of phthalic anhydride, 0.4 parts of catalyst B (epoxy content 4.5% by weight) are added at 150 'C.

The mixture is heated to 220 ° C in the presence of 4.27 parts by weight of xylene. Cooking is carried out at this temperature under inert gas flow with azeotropic water removal.

-3EN 202561 A

When the acid number is less than 10 mg KOH g and the viscosity reaches a run time of 150 s in a 60% solution of xylene, it is diluted with xylene to 60% by weight after cooling.

Resin paints are so-called. they can be used as household enamels.

Example 4

50.0 parts by weight of tall oil fatty acid, 18.8 parts by weight of pentaerythritol and 19.3 parts by weight of phthalic anhydride in the presence of 4.7 parts by weight of xylene are heated to 200 ° C with stirring.

The azeotropic water separation is continued at the indicated temperature up to an acid number of 15.

The mixture is cooled to 180 'C and 1.2 parts by weight of catalyst "C" (epoxy content 9.5% by weight) and 5.6 parts by weight of phthalic anhydride are added.

The mixture was heated to 220 ° C and further cooked with azeotropic condensation until the acid number 20 was less than 10 mg KOH / g and the viscosity in the 50% solution of white spirit was 300 s. value.

Resin paints can be applied by brush and spray, and can be used for both industrial and domestic applications.

Example 5

56.0 parts by weight of sunflower oil, 3.6 parts by weight castor oil, 12.5 parts by weight glycerol are heated to 230 ° C. Then 0.1 parts by weight of calcium oxide are added under inert gas flow and the mixture is heated to 250 ° C.

The alcoholysis is continued until a positive methanol test is performed, then the solution is cooled to 180 ° C and the following substances are added:

21.8 parts by weight of phthalic anhydride, 0.3 parts by weight of malic anhydride, 1.0 parts by weight of catalyst "D" (epoxy content 4.0% by weight) and 4.7 parts by weight of xylene.

The azeotropic water separation is carried out at 230 ° C until the acid number drops below 7 mg KOH / g and the viscosity in a 70 wt% white spirit solution reaches a flow time of 200 s.

Resin lacquers and paints are suitable for weather-resistant wood and metal coatings

Example 6

All proceed as in Example 2 but using catalyst JE instead of A (epoxide content 9% by weight).

Example 7

All proceed as in Example 3, but using "F" (epoxy content 5% by weight) instead of "B"

Example 8

All proceed as in Example 2, but using catalyst G (epoxide content 10% by weight) instead of catalyst A.

Example 9

All proceed as in Example 5, but using catalyst "H" (12% w / w epoxy) instead of catalyst "D".

Example 10

2-4. The most important manufacturing parameters of the resins prepared according to Embodiments 1 to 9 are shown in the table below, compared to control resin solutions prepared without the use of a catalyst, with the same composition and manufacturing parameters.

As an additional control (Experiment K), Example 5 was repeated, but the same amount of dibutyltin oxide was used instead of catalyst D.

Example 2 times. than 2, for example. Cat. k. 3.pld. 3.pld. times. Cat. acc. 4.pld. times. than 4, for example. Cat. k. 5.pld. times. than 5.pld. Cat. k. 7.pld. serum Rin Experiment "K" Produce. Temp. 200'C 220'C 230 'C 250 'C 220'C 230'C 230'C 250'C 200'C 250'C Gyártádő (Hours) 20 24 24 35 22 26 26 42 22 35 color number (mgJ2 / 100g) DIN 6162 10 15 8 15 12 20 10 20 16 22 végsavsz. DIN 53402 (mgKOH / g) 8 17 5 14 12 16 6 12 18 10 energiafelh. (KWh / t) 250 350 400 600 320 400 440 750 280 610

It can be seen from the table that the cooking times of the resins made with the catalyst according to the invention are about 60 to 15-40% shorter, and the cooking temperature and energy consumption are significantly lower.

Its end parameters are more favorable than those made without or with conventional catalysts in terms of color and final acid number of the resins.

Claims (4)

PATIENT INDIVIDUAL POINTS A process for preparing oil-modified alkyd resin solutions of monocarboxylic acids, wherein the monocar-4HU 202561 is 50-100% by weight of unsaturated fatty acid or partially or fully triglyceride thereof - one or more polycarboxylic acids and / or polycarboxylic anhydrides and one or more polyalcohols 160 By condensation at a temperature of between < RTI ID = 0.0 > 160 < / RTI > and continuous removal of water from the reaction, comprising from 0.2 to 1.5% by weight of an epoxidized oil or an alkylated epoxide oil containing from 3 to 12% by weight of the reaction mixture. a chelating catalyst consisting of a mixture of epoxycarboxylic acid ester or 2-ethylhexylglycidyl ether or pentaerythritol tetraglycidyl ether or neopentyl glycol glycidyl ether and dibutyl tin oxide in which the weight ratio of the components is 1: 1 to 1: 2 before the reaction mixture is heated or 140-180 ° C (after first change: 1990.11.05) 2. A process for preparing oil-modified alkyd resin solutions of monocarboxylic acids, wherein 50-100% by weight of monocarboxylic acids are unsaturated fatty acids or partially or fully triglycerides thereof - one or more polycarboxylic acids and / or polycarboxylic anhydrides, and one or more polyalcohol 160 'C and 260' By condensation at a temperature between C and C by continuous removal of the water formed during the reaction, comprising from 0.2 to 1.5% by weight of epoxidated oil or alkyl epoxide containing from 3 to 12% by weight of epoxy group on the reaction mixture; carboxylic acid ester and dibutyl tin oxide mixture, in which the weight ratio of the components is between 1: 1 and 1: 2, before the reaction mixture is heated or 140-180 ° C after the melt temperature is reached. (Previous: 13/12/1989) 3. The method of claim 2, wherein the epoxidized oil is epoxidized soybean or linseed oil. (Priority for change: 13/12/1989.) 4. The method of claim 2, wherein the alkyl epoxycarboxylic acid ester is epoxidized octyl oleate or di (2-ethylhexyl) tetrahydrofalate. (Priority for change: 13/12/1989.)