CURABLE TRANSPARENT RUBBER COMPOSITION, A CURED TRANSPARENT RUBBER COMPOSITION MADE THEREOF, AND MANUFACTURING PROCESS FOR THE SAME

摘要

The present disclosure relates to a curable transparent rubber composition containing one or more synthetic isoprene polymers, a styrenic block copolymer, a curing agent, and additives that do not influence transparency of the final composition. Once cured, the curable transparent rubber composition has a haze of less than 30% and a total light transmission of more than 80%. The disclosure further relates to a cured transparent rubber composition made thereof, and a manufacturing process for the cured composition. The present disclosure also relates to an article including the rubber composition, in particular for tubes, medical stoppers, catheters, dental dams and other medical applications and artificial nipples.

主权项

1. A solid curable, transparent, rubber composition that once cured has a haze of less than 30% and a total light transmission of more than 80%, both measured according to ASTM D1003-13, comprising:
Component (a): from 15-80 wt. % of one or more synthetic isoprene polymers having a refractive index of between 1.500 to 1.525 at 23° C.; Component (b): from 15-80 wt. % of a styrenic block copolymer having 2 or more poly(vinyl aromatic) blocks and at least one block of polymerized conjugated diene, wherein the styrenic block copolymer has a weight average molecular weight of 150,000 to 250,000, the poly(vinyl aromatic) blocks have a weight average molecular weight ranging from 9,000 to 15,000, and the content of poly(vinyl aromatic) blocks in the styrenic block copolymer ranges from 8 to 13 wt. %, based on the total styrenic block copolymer wherein the difference between the refractive indices of component (a) and (b) is 0.100 or less; Components (c) and (d): from 0.05-8.0 wt. % of a curing agent, optionally with a co-agent, and Component (e): from 0.01-20 wt. % of additives that do not influence the transparency,wherein all amounts are in percentages by weight on the total composition.