Light diffusing styrene copolymer compositions
AssigneeIneos Styrolution Group GmbH
InventorsTobias SCHULZ, Eike JAHNKE, Ricardo Daniel FAJARDO
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Abstract
The invention relates to a styrene copolymer composition comprising a) 60 to 99.9% by weight of styrene-based polymer matrix component A, b) 0.1 to 5% by weight of PMMA-based, cross-linked polymer bead as light diffuser component B, wherein the polymer beads have an average particle diameter from 0.5 to 20 μηη and a refractive index ranging from 1.34 to 1.55, and c) 0 to 39.9% by weight of further component C, different to A and B, wherein the sum of components A) to C) is 100% by weight and the composition exhibits a light transmittance greater than 80%, a haze greater than 90% and a Yellowness Index less than 4.5.
Claims16
1-15. (canceled)
A styrene copolymer composition comprising:
- a) 60 to 99.9% by weight of at least one styrene copolymer as matrix component A,
- b) 0.1 to 5% by weight of at least one type of PMMA-based, cross-linked copolymer beads as light diffuser component B, wherein the polymer beads have an average particle diameter from 0.5 to 20 μm and a refractive index ranging from 1.34 to 1.55, and
- c) 0 to 39.9% by weight of at least one further component C which is different to A and B,
- wherein the sum of components A to C is 100% by weight, and wherein the styrene copolymer composition exhibits a light transmittance (determined by ASTM D1003) of greater than 80%, a haze (determined by ASTM D1003-95) of greater than 90%, and a Yellowness Index (determined by ASTM E313) of less than 4.5.
A process for the preparation of a styrene copolymer composition, comprising:
- a) 60 to 99.9% by weight of at least one styrene copolymer matrix component A,
- b) 0.1 to 5% by weight of at least one PMMA-based, cross-linked copolymer bead as light diffuser component B, wherein the polymer beads have an average particle diameter from 0.5 to 20 μm and a refractive index ranging from 1.34 to 1.55, and
- c) 0 to 39.9% by weight of at least one further component C which is different to A and B,
- wherein the sum of components A to C is 100% by weight,
- wherein the process comprises the steps of:
- (i) dispersing component B or a master batch comprising component B in the matrix component A and optionally adding component C,
- (ii) heat treatment with a temperature of 150 to 250° C., and
- (iii) cooling the styrene copolymer composition below the glass transition temperature (Tg) of the composition.
Dependencies are inferred from the claim text.