CS227510B1 - Modified alkyd resins and method of preparing same - Google Patents

Description

The invention relates to modified alkyd resins, methyl esters of benzoic acid and / or tolylic acid. These alkyds are excellent binders especially for paints for building-joinery products, but also for metal treatment.

Alkyd resins are currently one of the most widespread types of binders for paints (Martin Ch. P.,

J. of Oil Col. Chemababc, 59, 1976, pp. 322-330). Their usual methods of preparation have been known for several decades and are described in basic monographs (eg: J. Mleziva et al.: Polyesters, their production and processing. SUTI, Prague 1978, p. 209 - 332) · The most common types - oil alkyds they contain 25 to 70% by weight · oil or aliphatic monocarboxylic acids · Other ingredients are 2 to 3 functional carboxylic acids and polyhydric alcohols. Depending on the average functionality of the batch, macromolecules of different sizes and branches are formed, which is manifested in all properties of alkyds. The relationships between the batch composition and the degree of conversion, which were generally derived for the polycondensates Carothers, Korsak and others, were also very well applied to the case of alkyds (Patton T. C., Alkyd Kesin Technology, Pormulating Techniques and Allied Calculations, Intersc. Publ.) New York 1962) · Despite the fact that it exceeds a certain critical limit of average functionality, the shaft may gelatinize ·

It has now been found that the safety of the preparation, even of short and medium alkyds, can be substantially increased and, moreover, to produce products with improved solubility, controllable viscosity, accelerated drying and good viscoelectric properties when utilizing the present invention. The invention relates to modified alkyd resins based on vegetable oils and / or aliphatic unsaturated monocarboxylic acids, polyalcohols, polycarboxylic acids and modifiers and to a process for their preparation. The subject of the invention is that these alkyd resins are transportable from 300 to 700 parts by weight of vegetable oils and / or unsaturated aliphatic monocarboxylic acids of carbon atoms numbering 9-22, both with an iodine number of 90 to 195 g J _2/100 g, from 80 to 260 wt. parts of 2 to 5 strong alcohols, 200 to 300 wt. parts by weight of dicarboxylic acids or anhydrides thereof having a carbon number of 4 to 10 and 10 to 200 wt. There are two alternatives to the preparation of the resins of the benzoic acid and / or p-toluic acid methyl ester modifiers. The first is that 300 to 700 wt. parts vegetable oil with an iodine number from 90 to 195 g _J2 / 100 g with a temperature of 210 to 260 ° C in an inert gas atmosphere přeesterfikační reacted with 80 to 260 wt. parts of 2 to 5 strong alcohols, catalysed by compounds of elements 1 to 2 of the periodic system, in particular PbO, CaO, IFagCO 4, and the resulting hydroxyester is left in the next reaction step at 180 to 260 ° C in the presence of inert gas or azeotropic solvents of the aromatic hydrocarbon group of the benzene series having 7 and 10 carbon atoms are reacted with 200 to 300 wt. In any one of the stages of preparation, 10 to 200 wt. parts of modifiers, such as methyl esters of benzoic acid and / or p-toluylic acid, and 0.1 to 1.2% by weight, based on the weight of the modifiers, of the catalyst of the group of zinc, cobalt or tin monocarboxylic acid; acidity of the product below 15 mg KOH / g. A second alternative to the process is that 300 to 700 wt. parts vegetable oil with an iodine number from 90 to 195 g J _2/100 S is subjected when Heat- 3

227 510 to 210 to 260 ° C in an inert gas atmosphere with an overesterification reaction of 200 to 300 wt. parts of dicarboxylic acids having a carbon number of 4 to 10, preferably isophthalic acid, and the resulting mixture of carboxy esters is left in the next step at 180 to 260 ° C in the presence of an inert gas or azeotropic solvent from the 7 to 7 aromatic hydrocarbon group. 10 carbon atoms can be reacted with 80 to 260 wt. parts of 2 to 5 strong alcohols. 10 to 200 wt. parts of the modifier, which are methyl esters of benzoic acid and / or p-toluylic acid, and 0.1 to 1.2% by weight, based on the weight of the modifier, of the catalyst of the group of zinc, cobalt or tin monocarboxylic acid; acidity of the product below 15 mg KOH / g.

In particular, for the modified alkyds of the present invention, vegetable oils which can be used are linseed, soybean, safflower, sunflower, citric, wood, rapeseed, castor, dehydrated castor oils, as well as chemically treated oils, i.e., cyclopentadiene oils. epoxidized, styrenic and the like. The aliphatic monocarboxylic acids used may be those obtained by the cleavage of oils or their subsequent treatment, for example certain selected fractions depleted or enriched in a certain type of acid. Synthetic aliphatic acids obtained by oxidation of paraffin fractions or by other means may also be used. As polyalcohols, especially ethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, glyoerol, pentaerythritol, xylitol, sorbitol, mannitol can be used. As dibasic acids, for example, isophthalic acid, terephthalic acid or o-phthalic acid or their functional derivatives, such as methyl esters or anhydrides, and also tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid or aliphatic acids, in particular adipic acid. Nitrogen, COg or combustion gases with an oxygen content below 1% by weight are preferred as inert gases. Toluene, xylene, ethyl and diethylbenzene are used as azeotropic solvents. The modifiers used are benzoic acid methyl ester, p-toluylic acid methyl ester, or all mixtures thereof.

The preparation can be carried out by a melt or azeotropic process. When monocarboxylic aliphatic acids (fatty acids) are used, the manufacturing process is simpler because the need for a transesterification of the oils with a polyol or dicarboxylic acid is eliminated. The transesterification can be monitored by any of the known methods, i.e. either by miscibility with methanol or ethanol, or by measurement of conductivity or dielectric constant. The modifying methyl esters may be introduced into the reaction mixture prior to or simultaneously with the addition of the dicarboxylic acids or at any other stage of the polyesterification prior to achieving the stated conversion rates (characterized by acid numbers). This depends on the average batch functionality and degree of gelation risk. It is preferred, especially for short alkyds, to add mo-5

227 510 diffuser at the same time or before addition of dicarboxylic acids ·

Advantageously, methyl benzoate is a low-viscosity liquid at temperatures of about 20 ° C, and also mixtures of methyl benzoic and p-toluyl esters in the range of 1: 1 to 4: 1 by weight are liquid under these conditions. toluyl, however, is a crystalline solid having a melting point of 26 ° C.

Prepared alkyd resins in the form of their solutions in white spirit, xylene or mixtures thereof can serve as binders of various types of paints ·

Compared to unmodified types of the same oil length, they have lower viscosities, are higher pigmentable, dry faster, provide harder and more mechanically resistant coatings · Can also be combined with other types of alkyds, as well as other conventional medical binders · Modification improves and expands combination options ·

The following are non-limiting Examples * The composition is given in weight units ·

Example 1

To a 1500 L reactor was charged 556 kg of flaxseed oil with an iodine value of 183 g Jg / 100g and 158 g of pentaerythritol, 0.083 kg of PbO and 0.030 kg of CaO were added with stirring. 1 hour after this temperature is reached, samples are taken at 15 minute intervals · Miscibility with methanol is monitored · Re-esterification is completed when the maximum miscibility stage is reached (the next sample already shows less or the same miscibility than the previous one). The reaction mixture is cooled to 180 ° C, 240 kg of phthalic anhydride and 46 kg of methyl are added.

-6227 510 benzoic acid ester · 0.230 kg of zinc acetate and 19 kg of xylene · Gradually heated to 250 ° C to distill off the reaction of liberated methanol (10.4 kg) and water (29.2 kg) · Preparation is complete at Acid value below 10 mg KOH / g ·

The prepared 58-length alkyd is dissolved in a 60% solution in white spirit.

After desiccation (0.03% Co + 0.5% Pb + 0.3% Ca in the form of naphthenate), it dries to Stage 1 within 1.5 hours and Stage 5 within 24 hours. that have good adhesion to wood and metal surfaces ·

Alkyd is perfectly miscible with other long and medium alkyds ·

Example 2

To a 1500 L reactor was charged 663 kg of soybean oil with an iodine value of 137 g Jg / 100g and 216 kg of isophthalic acid was added with stirring. The mixture was heated while introducing CO ₂ and 260 ° C for 2.5 h. allow transesterification to occur · Pakistan is cooled to 190 ° C and 86 kg of pentaerythritol and 22 kg of sorbitol are added · With the introduction of CO _{2 it} is heated to 240 ° C while draining the water reactants · After 2 hours from heating monitors the acid number · After reaching an acid number of 70 to 90 mg KOH / g, it is cooled to 180 ° C and 11 kg of p-toluylic acid methyl ester, which has been heated to 50 ®G in a heated weighing scale, is added · 0.113 kg / cobalt octoate and gradually heated to 240 ° C to distill off the reaction of liberated methanol (2.5 kg) and water (46.5 kg in total) · Preparation is terminated when the acid number drops below 10 mg KOH / g

Prepared alkyd with an oil length of 70 dissolves in a 65% solution in white spirit. At the same dessication as in Example 1, it dries to Stage 1 in 3.5 hours and is a suitable binder for paint

- 7 227 510 paints for brushing, both basic and enamels *

Due to its lightfastness, it is particularly suitable for coating white and light shades.

Example 3

402 kg of safflower oil with an iodine value of 142 g Jg / 100g are charged to a 1500 l reactor and 191 kg of pentaerythritol and 0.206 kg of BagGO are added with stirring. Heat to 260 ° C with nitrogen, and allow pre-heat treatment, whose progress is monitored as described in Example 1 · upon completion of alcoholysis, the reaction mixture was cooled to 180 ^g C. and 264 kg tetrahydrophthalic anhydride and 143 kg of technical mixtures of the methyl esters of benzoic acid and p-toluic acid (wt. ratio 7: 3) · added 55 kg of xylene and 0.206 kg of zinc acetate. Then they are gradually heated while continuously removing the reaction water and methanol. The preparation was terminated when the acid number was below 12 mg KOH / g. The prepared oil length 43 is dissolved at 100 to 120 ° C in a mixture of white spirit and xylene (3: 1) to a 55% solution.

It is an excellent binder for paints. It is miscible with medium and long oil alkyds and especially in combination (1: 3 to 2: 3) with soya alkyd with an oil length of about 60 forms an ideal binder system for wood-based paints.

Example 4

To a reactor having 1,500 1 was charged with 327 kg of aliphatic carboxylic (fatty) acids of soybean oil with an iodine number of 140 g Jg / 100g and 131 kg of aliphatic carboxylic (fatty) acids, dehydrated castor oil having an iodine number of 125 g _J2 / 100 g; 146 kg of pentaerythritol, 11 kg of ethylene glycol and 74 kg of trimethylolpropane (232 kg) are added with stirring

- 8227 510 phthalic anhydride) and 78 kg of technical mixture of methyl esters of benzoic acid and p-toluylic acid (mass ratio 1: 1) are allowed * 0.385 kg of cobalt naphthenate are added as catalyst. The mixture was heated to 240 ° C with CO 2, while distilling off the reaction water and methanol. The preparation is terminated when the acid number falls below 10 mg KOH / g ·

The prepared alkyd having an oil length of 50 is dissolved in a white spirit-xylene mixture (mass ratio 1: Ί). This alkyd is a suitable binder for both base coatings and metal enamels.

Example 5

A 1500 l reactor is charged with 402 kg of rapeseed oil with an erucic acid triglyceride content below 3% by weight and an iodine number of 98 g Jg / 100 g, 128 kg of dehydrated castor oil fatty acids with an iodine number of 125 g Jg / 100 g ( content of conjugated fatty acids 40% by weight A 15 kg glycerol,

154 kg of pentaerythritol and 0.08 kg Κ ₂ >> ₃ and are mixed with _Z and heated to 250 ° C while stirring and introducing nitrogen. After 3 hours, cool to 180 ° C, add 60 kg of technical mixture of methyl benzoic acid φ-toluyl esters ( weight ratio 1: 1), 0.200 kg zinc acetate and heated to 220 ° C. After the reaction has subsided, the methanol evolution ceases, it is cooled to 190 ° C, 241 kg of phthalic anhydride, 55 kg of xylene are added and gradually heated to 240 ° C with constant removal of the reaction water. /G·

The alkyd is dissolved in a 60% solution in white spirit. It is miscible with other medium and long alkyds and especially in these combinations is a suitable binder coating *

Claims (3)

- 1 · 227 510 Modified alkyd resins based on vegetable oils and / or aliphatic unsaturated monocarboxylic acids of polyalcohols, polycarboxylic acids and modifiers obtainable from 300 to 700 wt. parts by weight of vegetable oils and / or aliphatic unsaturated monocarboxylic acids having a carbon number of 9 to 22, both with an iodine number of 90 to 195 g / g, 80 to 260 wt. parts of 2 to 5 strong alcohols, 200 to 300 wt. parts by weight of dicarboxylic acids or anhydrides thereof having a carbon number of 4 to 10 and 10 to 200 wt. parts of modifiers such as methyl esters of benzoic acid and / or p-toluylic acid. 2. Group of the periodic system, in particular PbO, CaO, NagCO4, 22 23/8 ^{, the} resulting mixture of hydroxy esters is left in the next reaction step at a temperature of 180 DEG-260 DEG C. in the presence of an inert gas or azeotropic solvent of the benzene aromatic hydrocarbon group. rows of 7 to 10 carbon atoms are reacted with 200 to 300 wt. parts of dicarboxylic acid or anhydride thereof having a carbon number of 4 to 10, wherein at any stage of the preparation 10 to 200 wt. parts of modifiers, such as methyl esters of benzoic acid and / or p-toluylic acid, and 0.1 to 1.2% by weight, based on the weight of the modifiers, of the catalyst of the group of zinc, cobalt or tin monocarboxylic acid; acidity of the product below 15 mg KOH / g. 2. A process for the preparation of modified alkyd resins according to claim 1, wherein 300 to 700 wt. parts vegetable oil with an iodine number from 90 to 195 g _J9 / 100 g with a temperature of 210-260 C in an inert gas atmosphere transesterification reaction with 80 to 260 wt. parts of 2 to 5 strong alcohols catalyzed by the compounds of elements 1 to 5; 3. A process for the preparation of modified alkyd resins according to claim 1, wherein 300 to 700 wt. parts of vegetable oils having an iodine number of 90 to 195 g Jg / θθ δ at 210 to 260 ° C under an inert gas atmosphere are subjected to a transesterification reaction with 200 to 300 wt. parts of dicarboxylic acids having a carbon number of 4 to 10, preferably isophthalic acid, and the resulting mixture of carboxy esters are left in the next reaction step at a temperature of 180 to 260 ° C in the presence of an inert gas or azeotropic solvent of the benzene series aromatic hydrocarbons. % of carbon atoms reacted with 80 to 260 wt. parts of 2 to 5 strong alcohols, 10 to 200 wt. parts of the modifier, which are methyl esters of benzoic and / or p-toluylic acid, and 0.1 to 1.2% by weight, based on the weight of the modifier, of the catalyst of the group of zinc, cobalt or tin monocarboxylic acid; a decrease in the acid number of the product below 15 mg KOH / g.