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US 2003/0125442 A1Published application
Free flowing powder
AssigneeKraton Polymers U.S. LLC
InventorsCatherine Augusta Louis Maris, Sonja Marie Oosterbosch
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AssigneeKraton Polymers U.S. LLC
InventorsCatherine Augusta Louis Maris, Sonja Marie Oosterbosch
Estimating the term…
The present invention relates to a free flowing powder composition with a particle size at most 800 μm comprising: (a) 100 parts by weight of one or more styrenic block copolymers, at least one of which being a block copolymer (a1) comprising at least one block S having a glass transition temperature Tg above 25° C., which contains polymerized units of a vinylaromatic monomer and at least one elastomeric block B/S having a Tg below 25° C., which contains polymerized units of both a vinylaromatic monomer and a conjugated diene in random sequence, wherein the ratio of block S to block B/S is from 1 to 40% by volume and wherein the amount of the conjugated diene is less than 50% by weight on the whole of the copolymer; optionally (b) 0 to 200 parts by weight of plasticizing oil; optionally (c) 0 to 200 parts by weight of a compatibilising resin; and optionally (d) a dusting agent in an amount of from 0 to 10% by weight based on total weight of composition. It also relates to a process for the preparation thereof and to homogeneous layers derived therefrom.
A free flowing powder composition with a particle size of at most 800 μm comprising:
A free flowing powder composition as claimed in any one of the preceding claims, wherein the particle size is smaller than 600 μm, preferably smaller than 300 μm with an average particle size that is at most 100 μm.
A free flowing powder composition as claimed in any one of the preceding claims, wherein the block copolymer (a1) has a glass transition temperature (Tg) in the range of −40° C. to −5° C. and a Tg in excess of about 60° C.
A free flowing powder composition as claimed in any one of the preceding claims, wherein the block copolymer (a1) has a melt flow rating at 200° C./5 kg in the range of 5 to 20 dg/min, preferably 10 to 15 dg/min.
A free flowing powder composition as claimed in any one of the preceding claims, wherein the block copolymer (a1) has an order-disorder transition temperature (ODT, the temperature at which the blocks are sufficiently compatible to form a single phase) in the range of 100 to 200° C., preferably in the range of 120 to 190° C., preferably about 145° C.
A free flowing powder composition as claimed in any one of the preceding claims, wherein component (a) comprises one or more further styrenic block copolymers (a2).
A free flowing powder composition as claimed in any one of the preceding claims, wherein component (a) comprises one or more further styrenic block copolymers (a2) in a weight/weight ratio of (a1) to (a2) of 5:95 to 95:5, preferably 10:90 to 90:10, more preferably of 20:80 to 80:20.
A free flowing powder composition as claimed in any one of the preceding claims, wherein the vinylaromatic monomer is styrene and the conjugated diene is either butadiene or isoprene.
A process for the preparation of the free flowing powder composition as claimed in any one of the preceding claims, wherein said process comprises the steps of:
A homogeneous layer obtained by fusing the free flowing powder composition as claimed in any one of the preceding claims.
Dependencies are inferred from the claim text.