CS269397B1 - Method of elastic alkyd resins preparation - Google Patents

Abstract

The procedure consists first in the reaction natural esters derived from glycerol and acyclic monocarboxylic acids acids of the specified iodine value with acyclic three to four alcohols in the presence of metal compounds 1st and 2nd columns of the periodic system elements in an inert atmosphere and at room temperature 220-260 ° C for 2-4 h. The resulting mixture of hydroxy esters is then added subjected to polyesterification at temperature 220-270 ° C in the presence of inert gas and / or in an organic solvent with oicarboxylic acids or their anhydrides and with a modifier prepared addition reaction of the cyclic anhydride with epeilone-caprolactam, up to decrease in acid number of the product below 15 mg KOH.g- 1.

Description

CS 269397 B1 1

BACKGROUND OF THE INVENTION The present invention relates to flexible alkyd resins used for the formulation of coating compositions drying with an oxypolymerization mechanism.

Among modern synthetic medical binders, eg based on polyester, polyurethane, polyamide, polyepoxide and polyacrylic resins, they retain the first place of alkyd resins, especially because their starting materials are available and relatively inexpensive. The production of resins is not complicated, and resins are easily processed into paints. Alkydes are prepared by reacting polyols with vegetable 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 firing. However, coating compositions based thereon also have some disadvantageous properties, such as slow film drying, softness, tackiness, yellowing tendency, low water, alkali and acid resistance. To remove these deficiencies, conventional types of alkyd resins are chemically or physically modified. Chemical modifications include, but are not limited to, reactions with unsaturated compounds, particularly maleization (Australian Patent No. 407,538, NSR Patent No. 2,441,935), cyclopentadienation (Belgian Pat., 832,926, NSR Patent No. 1,520,174), siliconization (SSS Authorization No. 394,406, US Patent No. 3,948,827) and urethanization (NSR Patent No. 1,644,750 and 1,644,801). Of the chemical modifications, styreneization is particularly important (French Patent No. 1,518,562, British Patent No. 1,376,194, etc.) and, more recently, acrylation (U.S. 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-lasting resistance to wind. Physical modifications include the mixing of alkyd resins with reactive inactive macromolecular substances, e.g., resins, urea-formaldehyde, melamine-formaldehyde (Belgian Patent No. 874,241, French Patent No. 2,192,155, NSR Patent No. 2,710,994), phenol formaldehyde (Belgian Patent No. 833,822, European Patent No. 2,488) and natural (Czechoslovak Patent No. 155,002, Japanese Patent No. 74,102,407), followed by vinyl polymers (NSR Patent No. 1 No. 770,299, U.S. Patent No. 3,468,826) and elastomers (Australian Patent Nos. 293,252 and 425,563). Recently, the increasingly prized property of alkyds is the high flexibility of the coating films formed therefrom.

It has now been found that flexible alkyd resins can be prepared by the process of the present invention, which is a process for preparing flexible alkyd resins based on reaction products of vegetable oils, carboxylic acids, polyalcohols and difficulty. SUMMARY OF THE INVENTION It is an object of the present invention to react at a temperature of 220 to 260 ° C, for a period of 2 to 4 hours, in the presence of metal compounds 1 to 2, and 400 to 650 parts by weight in an inert atmosphere. of natural esters of glycerol and acyclic monocarboxylic acids having an iodine value of 90 to 200 g J 2/100 g with 80 to 200 wt. parts of acyclic tri- to tetravalent alcohols. The hydroxyl ether mixture obtained is then subjected to a polyesterification reaction with 180-280 wt.% At 220-270 ° C in the presence of an inert gas and / or in an organic non-reactive solvent. parts of di-carboxylic acids or their anhydrides and 50 to 360 wt. parts of the modifier, which is the adduct of the cyclic anhydride with epsilon-caprolactam, until the acidity of the reaction product falls below 15 mg of KOH. The production of alkyd resins by the process described above can be carried out on conventional types of polycondensation reactors. Prepared resins are characterized by faster drying time (for drying types) and higher coating flexibility.

The alkyd resins prepared according to the present invention are reaction products of natural oils (triglycerides of acyclic monocarboxylic acids) with polyols, dicarboxylic acids and modifiers. The alcoholic component is polyvalent acyclic alcohols containing from 2 to 6 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 (e.g., 1,2- and 1,4-cyclohexanediol, 1,4-bis (hydroxy- Methyl) cyclohexane), hydrogenated or alkylene oxide oxidized bisphenols (eg 2,2-bis (4-hydroxycyclohexyl) propane, 2,2-bis (4-hydroxyethoxyphenyl) propane, 2,2-bis (4-hydroxypro) -poxyphenyl) propane), of trivalent alcohols in particular glycerol, 1,1,1-trimethylolethene, 1,1,1-trimethylolpropane, 2,3,4-pentanetriol, 1,2,3-trihydroxybutane, 1,2,6-hexantriola tris (2-hydroxyethyl) isocyanurate, from the group of four to hexavalent alcohols are pentaerythritol, dipentaerythritol. arabitol, sorbitol, xylitol and mannitol.

These alcohols can be used individually, but preferably in mixtures with each other.

Acidic components which may be involved in the preparation of alkyds of the following groups: In particular, straight chain acyclic monocarboxylic acids having from 4 to 22 carbon atoms occurring in mixtures of various compositions in vegetable oils. triglycerides. Of the vegetable oils, mainly linseed, soybean, dehydrated, castor, rapeseed, sunflower, cotton, safflower, oiticicum, and some other oils whose iodine number falls within the range of 80 to 200 g of 02/100 g are particularly suitable. or their anhydrides, especially phthalic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, hexahydrophthalic anhydride, isophthalic acid, adipic acid and sebacic acid. These anhydrides can also be used to prepare modifiers by addition reaction with epsilon-caprolactam.

The course of alkyd preparation is monitored by determining the acid number of the mixture and the viscosity of the alkyd solution in hydrocarbon solvents (white spirit, xylene).

The alkyd resin solutions prepared by the process of this invention are processed into both primer and enamel coatings. Modifiers, i.e. the addition products of sepsilone-caprolactam, can be prepared in advance or "in situ" in the alkyd reaction medium. Exemplary Modifiers used in the following examples are prepared by the following procedures:

The reactor modifier A was reacted with 148 g of phthalic anhydride 114 g of epsilon-caprolactam at 140 DEG C. for 5 hours. After this time, the reaction product was poured onto a metal sheet. A solid, pale white substance with an acid number of 220 to 225 mg KOH is obtained.

Modifier B

Under the same conditions, an acid value of 212 to 220 mg KOH.g is prepared by reaction of 152 g of tetrahydrofuran anhydride and 114 g of epsilon-caprolactam.

430 g of soybean oil (iodine number 126 g 32/100 g), 210 gpentaerythritol and 0.05 g lead oxide are introduced into the reactor. The reaction mixture was heated to 260 ° C under nitrogen flow and alcoholysis was allowed to proceed. The procedure is followed by measuring the conductivity reaction mixture and terminating the reaction after 1.5 h to 2 h. The reactor contents are cooled to 170 DEG C. and 259 g of phthalic anhydride with 340 g of modifier A are added. 50 .mu.l of xylene are added and the mixture is heated gradually to 230 DEG C. while removing the water-releasing reactions. The reaction is terminated when the acid number of the reaction mixture drops below 13 mg of KOH. The resins obtained are cooled to 140 DEG C. and not diluted to 60% with xylene. The viscosity of the product is 250 to 300 mPa.s.

The resin, after siccativation, dries to stage 1 in 2 hours, to stage 2 in 16 hours. Drying agents exhibit the following values: bore resistance 9 mm, impact resistance 100 cm, bending resistance through mandrel - at 3 mm coating intact. Compared to similar resins without modifiers, the property improved by 30-40%. Example 2

321 g of linseed oil (iodine number 190 g 32/100 g), 140 gpentaerythritol and 15 g glycerol are introduced into the reactor. After the addition of 0.1 g of calcium oxide and the introduction of CO 2 into the reactor, the mixture is heated to 240 ° C and the alcoholysis is allowed to proceed after 2.5 h. The reaction mixture is cooled to 150 ° C and 150 g is added. tetrahydroftalanhydride and 110 g epsilon-caprolactam. Maintain the temperature at 140 to 150 ° C for 3 h,

Claims (1)

Then, 194 g of phthalic anhydride and 70 g of xylene are added and the temperature is gradually raised to 235 DEG C. and the reaction water is withdrawn therefrom. The preparation is terminated by decreasing the acid number of the product below 10 mg of KOH. Alkyd resin dries to Stage 1 after 1.5 hours, to 2 to 6 ha to Stage 4 within 24 hours after siccativating. Dry coatings show the following values: pendulum hardness after 3 days 14%, digging resistance 8 mm, bending resistance - at 3 mm intact and 80 cm impact resistant. A similar resin without modifier was improved by 35%. EXAMPLE 3 500 g of linseed, 118 g of low-urea rapeseed oil (iodine number 95 g of 02/100 g), 100 g of pentaerythritol, 29 g of trimethylolpropane and 0.6 g of lithium hydroxide are introduced into the reactor. The reaction mixture is heated to 220 DEG C. with nitrogen in the reactor and maintained at this temperature until its maximum conductivity is reached; The reaction is cooled to 170 ° C and 210 g of isophthalic acid, 20 g of xylene and 30 g of methyl isobutyl ketone are added and the reaction temperature is gradually raised up to 260 ° C while the reaction mixture is distilled off. water. When the acid number falls below 30 mg KOH.g., the reactor content is cooled to 160 DEG C. and 60 g of B modifier is added. The esterification is continued until the acid value falls below 15 mg KOH. ^. After dissolving in white spirit and siccativating, the alkyd resin dries to a level of 1 to 3 hectares to a level of 2 to 12 h after being applied to the substrate. The dried coating has a hardness of 14% with a hardness of 7.5%, resistance to bending over thorn at 3 mm intact and 90 cm impact resistance. Compared to a similar type of modifier resin, properties improved by 15%. OBJECT OF THE INVENTION A process for preparing flexible alkyd resins based on reaction products of vegetable oils, carboxylic acids, polyalcohols and modifiers, characterized in that it is first reacted at 220-260 ° C for 2 to 4 h in the presence of metal compounds Columns 1 and 2 of the Periodic Table of the Elements and in an inert atmosphere of 400 to 650 wt. parts of natural glycerol esters and acyclic monocarboxylic acid iodine numbers of 90 to 200 g of J2 / 100 g with 80 to 200 wt. parts of the acyclic tri-four-alcohol alcohols and the mixture of hydroxy esters are then subjected to a polyester reaction with 180-280 wt% at 220-270 ° C in the presence of an inert gas and / or an organic non-reactive solvent. parts of dicarboxylic acids or their anhydrides and 50 to 360 wt. parts of the modifier, which is the cyclic anhydride addition product of β-caprolactam, until the acidity of the reaction product falls below 15 mg of KOH.g-1.