CS200449B1 - Polyester compositions,especially for transparent roof coverings - Google Patents

Description

One important application of polyester fiberglass laminates is their use as transparent, light-soluble roofing. The basic condition for achieving the transparency of glass laminates is that the refractive index of the cured unsaturated polyester resin is identical with the refractive index of the glass reinforcement. However, the cured standard types of unsaturated polyester resins have a higher refractive index, so that in their applications the glass reinforcement becomes clear and the laminate loses its transparency. Therefore, unsaturated polyester resins with a low refractive index have been developed for the preparation of transparent laminates. There are currently two types of polyester resins suitable for the preparation of transparent laminates. In the first group, a low refractive index is achieved by the use of special starting materials such as tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, hexahydrophthalic acid and the like. Use of said esters, especially tertiary butyl acrylate and methyl acrylate, to reduce the refractive index of unsaturated polyester resins and to improve the weather resistance of cured resins

200 449

200,440 influences are described in literature, such as, Demmler K: Chemie der verstarkbaren Kunstoffe; Selden P.H. Glasfaserverstarkte Kunststoffe-Springer Verlag Berlin 1967, pp. 29-30

R. Vieweg: Kunststoff-Handbuch, Band VIII, Polyester, Carl Haaser Verlag 1973, pp. 278-9; G. Gaylord: Encyclopedia of Polymer Science and Technology, Volume 11, Interscience Publishers N, Y. 1969, pp. 163; J. Mleziva: Polyesters, SNTL Praha 1958, p. 296. Due to the low boiling point of the esters, the above-mentioned resins have not yet been used for so-called hot lines where curing takes place at temperatures above 100 ° C.

Compositions of 70 to 99 wt. parts by weight of unsaturated polyester resin containing 15 to 40 wt. % of styrene, further from 1 to 30 wt. parts of 2-ethylhexyl acrylate, 0.25 to 3 wt. parts of a liquid peroxide initiator of the hydroperoxide type selected from the group consisting of methyl ethyl ketone peroxide, cyclohexanone peroxide _; methylcyclohexanone peroxide, methyl isobutyl ketone peroxide and / or mixtures thereof, and optionally 0.1 to 1 part by weight of a cobalt accelerator selected from the group of naphthenate or octoate and 0.1 to 2 parts by weight; parts of a UV-stabilizer, in particular of the benzophenone or benztriazole type.

Unsaturated polyester resins of conventional types based on polyvalent glycols, unsaturated, dicarboxylic acids and saturated aliphatic and / or aromatic dicarboxylic acids are used to prepare the polyester compositions of the present invention.

As the liquid peroxidic initiator of the hydroperoxide type, for example, methylcyclo hexanone peroxide, cyclohexanone peroxide, methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide or mixtures thereof can be used.

Cobalt octtoate or cobalt naphthenate containing from 1 to 6 wt. % cobalt.

Benzophenone types such as (2-hydroxy-5-methoxy) benzophenone, (4-dodecyloxy-2-hydroxy) benzophenone, 2,2-dihydroxybenzoA phenone, (3-benzoyl-2, 4-dihydroxybenzophenone and (2-hydroxy-4,4-dimethoxy) benzophenone; benztriazole types such as 2- (2-hydroxyphenyl) benztriazole, 2H2-hydroxy-5-methyl) benztriazole and others such as e.g. phenyl salicylate, dibenzoylresorcin and the like.

The advantage of these compositions is their high transparency, particularly in the production of roofing materials, and in particular the possibility of their use on production lines operating at curing temperatures in the range of 20-150 ° C, which has hitherto only been possible using special types of resins.

Example 1

K 96.1 wt. % of unsaturated polyester resin prepared from fumaric, phthalic and propylene glycol and containing 33.1 wt. % of styrene, 3.9 wt. % of 2-ethylhexyl acrylate, 0.23 wt. parts of 2- (2-hydroxy-5-methyl) benztriazole as a UV stabilizer and 0.30 parts by weight of cobalt naphthenate containing ca. % cobalt. 1.2 wt. % of a hydroperoxide initiator based on methyl isobutyl ketone peroxide and cyclohexanone peroxide containing 9.5 wt. % active oxygen. Thus

200 440 of the prepared mixture is impregnated with a glass mat and cured successively at 20 ° C to 150 ° C for a period of 1 to 15 minutes.

Example 2

K 74.0 wt. 26.0 wt. parts by weight of 2-ethylhexyl acrylate, 0.35 wt. % of (2-hydroxy-5-methoxy) benzophenones as U-stabilizer. 1.7 wt. % of a hydroperoxide initiator based on methylcyclohexanone peroxide. The prepared mixture is impregnated with a glass mat and cured gradually at 20 - 150 ° C for 1-15 minutes.

Claims (1)

THE SCOPE OF YOURSELF Polyester compositions, in particular for transparent roof coverings based on unsaturated polyester resins prepared by the reaction of glycols with K, t-unsaturated dicarboxylic acids and saturated aliphatic and / or aromatic dicarboxylic acids and containing crosslinking monomers, initiators and optionally accelerators and UV stabilizers, They consist of 70 to 99 wt. parts by weight of unsaturated polyester resin containing 15 to 40 wt. % of styrene, further from 1 to 30 wt. parts of 2-ethylhexyl acrylate, 0.25 to 3 wt. parts by weight of a hydroperoxide-type liquid peroxide initiator selected from the group consisting of methyl ethyl ketone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, methyl isobutyl ketone peroxide and / or mixtures thereof, and optionally 0.1 to 1 wt. % of cobalt accelerator from the naphthenate or octoate group; and 0.1 to 2 wt. parts of a UV-stabilizer, in particular of the benzophenone or benztriazole type.