CS243564B1 - Polymerizing processes accelerator - Google Patents

Abstract

Polymerization accelerator based on complex cobalt compounds, which is formed by the reaction product of cobalt salts of C2 to C30 carboxylic acids with alkali metal salts and ammonium rhodium hydride acid in a molar ratio of 1: 0.30 to 1.65 in an environment of oxygen-containing organic solvents. The solution can be used in the field of hardening of polyester resins, especially laminates and polyester varnishes. The use of the accelerator achieves cobalt savings.

Description

(54) Accelerator of polymerization processes

The cobalt complexation polymerization accelerator, which is the product of the reaction of the cobalt salts of carboxylic acids C2 to C30 with alkali metal and ammonium rhodium salts in a molar ratio of 1: 0.30 to 1.65 in an environment of oxygenated organic solvents.

The solution can be used in the field of curing polyester resins, especially laminates and polyester lacquers. By using an accelerator, cobalt savings are achieved.

The present invention provides an accelerator of polymerization processes based on complex cobalt compounds.

The free-radical polymerization of double bond compounds or curing of drying film-based coating films is accelerated by cobalt, manganese, lead salts, optionally in the presence of calcium, zinc and other metal salts. Developmental trends are progressing towards reducing the content of cobalt deficiency or increasing the catalytic efficiency of cobalt salts in polymerization processes. Given the complexity of the issue, the solution is not easy, so the task has not yet been satisfactorily solved.

According to the prior art, a partial increase of the catalytic efficiency in the polymerization of unsaturated polyester resins with complex cobalt compounds, in particular cobalt rhodanide, cobalt acetylacetonate and ammonium tetrarhodanocobaltate (NH 2 O 2 CO 2 CN) I has not been described.

Based on demanding studies, we have found a new accelerator of polymerization processes resulting from the reaction of cobalt salts of carboxylic acids with salts of rhodic acid in a molar ratio of 1: 0.30 to 1.65 in the environment of oxygenated organic solvents. The accelerator according to the invention is stable only in solution and its structure has not yet been accurately determined. At the same concentration, the catalyst according to the invention has up to ten times greater activity than the cobalt salts of carboxylic acids or ammonium tetrarhodanocobaltate alone.

The accelerator is prepared by mixing a solution containing 0.01 to 10% cobalt in the form of a ketone or alcoholic solution of acetate, octoate or naphthenate with a 0.01 to 15% solution of rhodic acid salts in the same solvent. Of the cobalt salts of carboxylic acids, salts of naphthenic acids, fatty acids C7 to C9 are generally used, but salts of carboxylic acids C2 to C6 can also be used. Of the salts of rhodic acid, the ammonium or potassium salts are used, but alkali metal and alkaline earth metal salts as well as soluble target salts can also be used. amines or quaternary ammonium bases.

In particular, acetone, methyl ethyl ketone is used as solvent, but higher ketones, acetylacetone, acetoacetates and the like can also be used. their mixtures with aromatics. Since the accelerator is formed by an ionic reaction, the reaction is completed in a fraction of a second after mixing the two reactants. According to circumstantial evidence, the idea of an ideal structural accelerator pattern is as follows:

where

X is

Ri \

C = O or R1-O-R2 /

R2

R 1 is C 1 -C 4 alkyl and others,

R 2 is H or R 1,

Me is an alkali metal or ammonium and

RCOO is an acid residue of the cobalt salt.

Example 1 part by weight of an acetone solution of cobalt octoate containing 0.50% cobalt is mixed with 1 wt. % acetone solution of ammonium rhodanide at a concentration of 0.2 to 2%. To 30 g of polyester resin Polyester 100, containing 2% methylcyclohexanone peroxide, was added various amounts of accelerator solution (0.2 to 1.6 milliliters). The gelation time (A) in minutes and the onset of exotherm (B) in minutes are monitored.

Amount NH4SCN (%) 0.20 AND (B) 0.00 54 - 0.20 43 78 0.50 38 56 1.00 41 77 2.00 - -

Amount of accelerator (ml) 0.40 0.80

AND (B) AND (B) 28 52 18 29 18 31 7 14 14 24 3 4 13 24 5 10 95 -, 46 59

1.60 Molar ratio (NHájSCN: Co AND (B) 15 Dec 25 - 3 10 0.310 1 4 0.775 2 3 1,549 32 40 3,089

The results show that an accelerator prepared from a SCN: Co molar ratio of 0.3 to 1.55 is more effective than cobalt octoate alone. Higher rhodanine excesses retard polymerization.

Example 2 wt. a part by weight of a methyl ethyl ketonic solution of cobalt naphthenate containing 0.20 wt. 0.12 wt.% NH-iSCN acetone solution. To 20 g of polyester resin formed by the polyesterification of 0.5 mole of maleic anhydride, 0.5 mole of phthalic anhydride and 1.02 mole of propylene glycol to an acid number of 40 mg KOH per gram, dissolved in a 70% solution in styrene, 0.5 g of methylcyclohexanone peroxide and ml of accelerator solution (mol ratio Co: NH4SCN = 1: 0.466). Gelation occurs after only 2 minutes and the onset of exothermic reaction is after 3 minutes. In contrast, the addition of 5 ml Co-naphthenate solution (0.20% Coj) to 20 g of the same polyester with 2.5% by weight methylcyclohexanone peroxide gels after 20 minutes and the exotherm starts after 56 minutes.

Example 3 wt. 1 part by volume of a 3% and 6% by weight solution of KSCN is added to 100 g of a 60% flaxseed alkyd resin solution, phthalic anhydride and pentaerythrites (63% by weight of linseed fatty acids, 22% pentaerythrites, 6% glycerin and 9% phthalic anhydride) in white spirit. The third sample is sonicated to the same Co content of 0.5 ml of naphthenate Co. The films are made 15 mm and the time hardness of the films is determined (according to ČSN 67 3076).

Conc. Drying CoSCN film drying

SCN Stadium A (% glass hardness) mol. ratio

(%) (min) 1 day Day 2 Day 5 7th day Day 9 0.00 60 8.3 10.4 18.3 28.0 30.4 _ 0.05 60 9.0 12.7 23.3 32.4 35.3 1,650 0.10 90 7.8 10.3 20.8 35.2 35.7 0,823

The accelerator also has a positive effect on the air-drying coating film, particularly in the drying stage, more effectively than the cobalt salt alone. Higher SCN excess is more retarding.

Claims (1)

SUBJECT An accelerator of polymerization processes based on complex cobalt compounds, characterized in that it is formed by the reaction product of cobalt salts of carboxylic acids with C2 BACKGROUND OF THE INVENTION to C30 with alkali metal and ammonium rhodic acid salts in a molar ratio of 1: 0.30 to 1.65, in an environment of oxygenated organic solvents.