SU1740182A1 - Method for antiadhesive treatment of moulds for shaping articles from polyurethanes - Google Patents

Abstract

The invention relates to chemical technology, specifically to the production of polyurethane soles, in particular, to the anti-adhesive processing of molds, and can be used in the molding of various polyurethane products. The invention allows to increase the service life of the molds; and to improve the surface quality of products due to the fact that molds with a hard anti-adhesive coating based on polysiloxanes, past 25 products, are treated with a composition containing hexamethyldisiloxane, octamethylcyclotetrasiloxane, polydimethylsiloxane oligomeric and gasoline, with the following ratio of components, May. am: hexamethylsiloxane 5 - 10; octamethylcyclotetrasiloxane 5-10; polydimethylsiloxane 40-50; gasoline 1000 - 1200. Processing is repeated periodically after 35 removal of products. 2 tab. with C

Description

The invention relates to chemical technology, specifically to the production of polyurethane soles, in particular to the anti-adhesive processing of molds, and can be used in the molding of various polyurethane products.

The aim of the invention is to increase the service life of molds and improve the quality of the surface of the products.

Example 1 A known anti-adhesive composition for a hard coating is prepared. Take 1000 wt.h. gasoline, add 100 wt.h. polydimethylsiloxane SKTN-A, 30 wt.h. polyethylsiloxane GKZH-94M, 8 wt.h. u-aminopropyltriethoxysilane AGM-9 and 0.05 wt.h. tin octoate. The resulting composition is mixed and sprayed with a spray is applied onto aluminum

A mold for molding polyurethane soles. The mold is heated at 140 ° C for 1 hour. A transparent polymer film with a thickness of 20-25 microns forms on the surface of the mold, which provides 25 removals of polyurethane soles, after which the surface of the mold Forms process the prepared liquid anti-adhesive composition. For its preparation take 100 wt.h. gasoline, add 5 wt.h. hexamethyldisilox-sans, 5 wt.h. octamethyltetracyclosiloxane, 40 wt.h. polymethylsiloxane PMS-200. A one-time treatment of a solid film with a liquid composition provides another 35 removals, after which the solid coating is again treated with a liquid composition, etc. once. Coating is stopped after ToX Jb O

00

Yu

As the sticking of the products to the mold begins. As a result, until the coating is re-coated with a solid film, the anti-adhesive action of 100 strips is ensured (see Table 1).

Example 2: An anti-adhesive composition for a hard coating is prepared. Take 1200 May kerosene hours, add 120 mash. poltidimetilsiloksana SKTN-A, 40 wt.h. polyethyl hydridesiloxane GKZH-94M, 10 ma.h. u-aminopropyltriethoxysilane AGM-9 and 0.1 wt.h. tin octoate. The resulting composition is agitated and sprayed with an atomizer onto an aluminum press mold. The mold is heated at 160 ° C for 1 hour. The sequence for treating the mold with compositions similar to Example 1 is 10 wt.h. for the preparation of a liquid anti-adhesive composition. hexamethyldisiloxane, 10 ma.ch. Octamethylcyclotetrasiloxane, 50 wt. polymethylsiloxane oligomeric PMS-200, 1200 wt.h. gasoline. The test results are shown in table 1.

Example 3: An anti-adhesive composition for a hard coating was prepared by mixing 1100 mas. kerosene, 110 wt.h. polydimethylsiloxane, 35 wt.h. polyethylsiloxane GKZH-94M, 9 wt.h. y-aminopropyltriethoxysilane and 0.075 wt.h. tin octoate. Conditions for obtaining a solid film and surface treatment

molds are similar to Example 1. 1100 parts by weight are mixed to obtain a liquid release composition. gasoline, 7.5 wt.h. octamethylcyclotetrasiloxane, 7.5 wt.h. hexamethyldisiloxane, 45 wt.h. oligomeric polymethylsiloxane PMS-200. The test results are shown in Table 1.

Other examples are presented in table 2.

Comparative data on the operating conditions of the molds, treated with known and proposed compositions, and the surface quality of the resulting products, are presented in Table 2.

Claims (1)

DETAILED DESCRIPTION OF THE INVENTION Method of anti-adhesive processing of molds for molding articles from polyurethanes, comprising applying a polysiloxane-based composition to the working surface of the molds, followed by thermal curing of the resulting coating, characterized in that, in order to increase the number of product removals, after 25 removal of the product the form is periodically every 35 removals treated with a composition containing hexamethyldisiloxane, octamelcyclotetrasiloxane, polydimethylsiloxane and gasoline in the following ratio of nantov, wt.h .: Hexamethyldisiloxane 5-10 Octamethylcyclotetrasiloxane 5-10 Polydimethylsiloxane40 - 50 Petrol 1000-1200 Table 1 Note. Examples 6.7 control