SU1193124A1 - Composition for making elastic polystyrenesiloxane rubber-base moulds - Google Patents

Abstract

COMPOSITION FOR THE MANUFACTURE OF ELASTIC FORMS ON THE BASIS OF POLYSTYLESILOXANE RUBBER mol.m. 50000-70000, containing 1.5-6 mol.% Methylvinylsiloxane units. including oligomethylsiloxane of the formula f (CH,) SiO, where p 6-10, with a content of ethoxyl groups of 1.82, 2%, hydroxyl groups of 1.7-1.9%, tetraalkoxysilane, and that, in order to increase the tensile strength of elastic forms and increase their service life, it contains tetrabutoxysilane as t & traalkoxysilane, and octate i tin as the organotin solidification catalyst in the following ratio (L components, ma Oligomethylsilox 100 rubber said formula tetrabutoxysilane 5-25 4-6 0.3-0.6 tin octoate; from about 4 to

Description

The invention relates to the rubber industry, namely to the creation of a composition for elastic forms.

The purpose of the invention is to increase the tensile strength of elastic forms and increase their service life.

The compositions are prepared by mixing polystyrene siloxane mol.m. 50000-70000, containing 1.5-6 mol. methylvinylsiloxane stars with oligomethylsiloxes of formula

t (CH3) jSiO, y SiOj,} .. where n 6-10,

with the content of ethoxyl groups of 1.8-2.2%, hydroxyphenyl groups 1.71, 9%. A mixture of tetrabutoxysilane with tin octoate is added to the resulting masterbatch. After thoroughly mixing the composition, I vacuum it for 3 minutes. The initial viscosity of the compositions is determined on a Hepper reoviscometer and viability is assessed. The vulcanization is carried out at room temperature for 24 hours; the physical and mechanical properties of rubber are determined by linear shrinkage.

In tab. i presents the characteristic of polyvinyl styrene rubber; in tab. 2 - compositions of the compositions; in tab. 3 - technological ,.

physicomechanical and operation. ,

93124. 2

compositional characteristics of vulcanizates.

As can be seen from the table. 3, the highest tensile strength at break

Jh6.0-6.3 MPa) have vulcanizates based on compositions containing oligomethystiloxane, tetrabutoxysilane and tin octoate in ratios (1.67-3.34):: (0.08-1.0), respectively. Thus, the tensile strength at rupture of the proposed composition is 2 times greater than that of the known composition, and the relative elongation remains at the same level for 40 days.

Higher strength characteristics of rubber make it possible to increase the number of product removals from one elastic form by 3 times compared with

2Q with a known composition, which leads to a decrease in the cost of forms. The reduction of linear shrinkage by 10 times allows the use of forms for the replication of products with complex volume

25 configurations requiring exact dimensions.

 -.

Reduced cure time

composition 2 times contributes to 2Q increase in productivity in the transition to a continuous process of production of elastic forms. Table 1

Molecule 50,000 60,000 weight Methylvinylsiloxane content. stars 6, 0 4.5 ny

Table 2 7000060000 60000 50000 70000 70000 4.0 3.0 3.0 2.0 2.0 1.5 Oligomethylsiloxane 10.6 Diethyldicaprylate tin 0.2 Tetrabutoxysilane -. Octoate 0.2 0.3 0.4 0.5 tin - Note: Compositions by example Indicators Values of indicators for s Known Initial viscosity, at 20 ° C, Pa of 17.9 11.6 12, Viability, - min 180 - 40 60 50 Vulcanization time, days2 1, 1.1 Strength at xpcr, MPa, after 2.45.2 5.7 I day 3.0 2.55.2 5.7 20 days. 3.3 40 days 3.4 2.5 5.1 5.6 Relative elongation%, after 130 190 00 1 day 420 120 190 200 20 days 285 120 180 200 40 days 230

Continued table. 2 15 20 25 30 0.6 0.6 0.6 0.6 and 8 controls, m 1 Table 3 Avs following the example of IDZI 5 10.5 9.7 8.3 7.75 7.05 110 120 140 180 90 1 1 I 6,3 6 6 6 6 6 6 6 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5,8 5 3 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 5.2 5.2 250 280 300 270 250 250 230 250 250 270 230 230 200 190 190 250

rolling data for formulations

Indicators

Famous. I 1 G 2 I 3 4 5 1 6 1 7 | eight

Residual

O 00 O elongation D 12 Linear 2,1-2,3 0,1-0,1- 0,1 contraction,% -0,2 -0,2 -0,2 The number of product removals from one elastic form (until its destruction 78 110 130 neither), pcs. 53

Continued table. 3 0.1 0.1-0.2-0.4- 0.7-0, 2 -0.2 -0.3 -0.7 -1.2 150 1-50 120 100 70

Claims (1)

COMPOSITION FOR MANUFACTURE OF ELASTIC FORMS ON THE BASIS OF POLYSTYRENE SILOXANE RUBBER mol.m. 50000-70000, containing 1.5-6 mol. Z methylvinylsiloxane units, including oligomethylsiloxane of the formula [C (CH ₃ ) ₃ SiO _0i j [Sio ₂ ]} _n , where η = 6-10, with the content of ethoxy groups of 1.82 , 2%, hydroxyl groups 1.7-1.9%, tetraalkoxysilane and an organotin curing catalyst, characterized in that, in order to increase the tensile strength of elastic forms and increase their service life, it contains tetrabutoxysilane as t & traalkoxysilane, and as Organotin curing catalyst - octoate e tin in the following ratio, as.ch .: Policy tirolsiloksanovy rubber Oligometilsiloksan said formula tetrabutoxysilane stannous octoate 100 5-25 4-6 0.3-0 .6. SU, 1193124> Ί 193124