The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 23, 1996
Filed:
Dec. 16, 1994
Pascal Nicol, Pau, FR;
Other;
Abstract
The invention relates to a star block copolymer of the formula [S.sub.1 -S.sub.2 -(B.sub.1 /S.sub.3)-B.sub.2 ].sub.m -X-[B.sub.2 (B.sub.1 /S.sub.3)-S.sub.2 ].sub.n in which X represents a polyfunctional radical resulting from a coupling agent, m and n represent non-zero integers such that m+n is equal to 3 or 4, S.sub.1 and S.sub.2 each represent a block of a polymer containing at least one vinylaromatic monomer, B.sub.2 represents a block of a polymer containing at least one conjugated diene, (B.sub.1 /S.sub.3) represents a block of a statistical copolymer containing at least one vinylaromatic monomer and at least one conjugated diene, 40 to 75% by weight of (B.sub.1 /S.sub.3) consisting of resulting from vinylaromatic monomer, characterized in that the sum of the mass of the blocks B.sub.2 contains more than 40% by weight and less than 90% by weight of the total mass of the conjugated diene contained in the said star block copolymer. The invention also relates to the process for obtaining this copolymer. The compositions comprising this copolymer and crystal polystyrene have noteworthy mechanical properties and transparencies.