CS210367B1 - Process for producing unsaturated polyester resins - Google Patents

Abstract

The invention provides for the production of unsaturated polyester resins in a reactive solvent by polyesterification of polybasic cardonic acids with polybasic alcohols in the presence of a mixed esterification-isomerization catalyst. The use of this catalyst shortens the time for their preparation and thus increases the efficiency of production.

Description

1 210367

The invention relates to a process for the production of unsaturated polyester resins. The raw materials used are saturated and unsaturated acids or their anhydrides and glycols, especially ethoxylated glycol diethylene glycol, propylene glycol 1,2, propylene glycol, optionally butylene glycol 1,3 with suitable auxiliaries such as esterification catalysts, antioxidants and stabilizers.

The polyesterification reaction is usually carried out in the presence of an inert gas at temperatures of 160 to 250 ° C and upon reaching the specified qualitative parameters, the unsaturated polyester resin prepared is diluted with styrene or another suitable reactive monomer.

Depending on the size of the reactor, the mixing intensity of the reaction mixture and the heat treatment mode of the polyesterification, the reaction times of these finished polyester resins are typically 16 to 26 hours, and can be more particularly accelerated by the addition of suitable esterification catalysts or catalyst systems. It is known from the prior art that the most advantageous catalysts are esterification reactions with the most numerous side reactions! transition metal metals (U.S. Pat. No. 3,055,867); U.S. Pat. No. 3,056,818, U.S. Pat. No. 3,057,824), but mainly barbecue organometallic compounds of cine, lead, titanium, zirconium, vanadium and antimony, the effectiveness of which depends essentially on the type after the condensation reaction, on the composition of the reaction mixture, mainly on the gly * kolu.

For example, as the polyesterification catalyst, an organometallic compound of the formula MHT 1 O / z is used, where M 1 is lium, sodium or potassium and R is a C 1 -C 6 compound / US Pat. No. 2,720,502], or tetraethylol / U.S. Pat. No. 2,720,505].

The effect of mono- and / or dicarboxybenzenesulfonamides or their N-substituted derivatives is also known for the catalyzed esterification of isophthalic acid or its derivatives and phthalic anhydride with polyfunctional alcohols. No. 3,008,928].

However, the drawback of said organometallic compounds in their use as esterification catalysts in the preparation of unsaturated polyester resins is the fact that, more or less, they always affect the degree of isomerization of the maleic acid and the curing characteristics of the prepared resins, in particular the maximum cure exotherm. 4

It has been found that the aforementioned drawback is avoided by the use of catalytic systems comprising at the same time a polyesterification reaction accelerating component with a component catalyzing the simultaneous isolation of maleic acid to isomeric fumaric acid, which is known to be effective.

According to the present invention, unsaturated polyester resins are prepared in a reactive solvent, preferably styrene, by esterification of polyhydric aromatic and aliphatic carbon acids with polyhydric alcohols at a temperature of 160-240 ° C, the polyesterified mixture containing maleic anhydride and / or maleic acid and polyesterification being in the presence of 0.01 to 10 wt. a mixed esterification-isomerization catalyst, wherein the isomerization catalyst is phosphoric acid, hydrochloric acid, hydroxyamine hydrochloride, or alkali metal halides and a halogen atom of 35.457-79.916, preferably potassium bromide.

As the esterification catalyst, for example, organometallic tin compounds and preferably tetrabutylium tannate or polybutylate titanium (Tilcom PBT) can be used as the isomerization catalyst such as NH4 OH, HCl, H2 PO4, HCl, LiBr or NaBr, preferably KBr. An advantage of the present invention is to increase the economics of producing unsaturated polyester by reducing the time of their preparation.

Comparison of unclassified polyesterification of 511.6 g of diethylene glycol, 385.1 g of phthalic anhydride

Claims (2)

OBJECT OF THE INVENTION, i. . · Process for the production of an unsaturated polyester resin in a reactive solvent, preferably styrene, by polyesterification of polyhydric aromatic and aliphatic carbon acids with polyhydric alcohols at a temperature of 160 to 240 ° C, characterized in that the polyesterified mixture comprises maleic anhydride and / or maleic acid and the polyesterification is carried out in the presence of 0.01 to 10 wt. The esterification catalyst used is phosphoric acid, hydrochloric acid, hydroxyamine hydrochloride or ha, alkali metal logenides having a halogen atomic mass of 35,457 to 79,916, preferably potassium bromide, as the isomerization catalyst. 2. The process according to claim 1, wherein the esterification catalyst is tetraalkyl titanate, polybutyl titanate or organometallic tin compound as dibutylindiurate and / or bis / tributyleine / oxide.