| US 7,579,385 B1 | ||
| Dried porous crumbs of hydrogenated block copolymer | ||
| Yasumasa Yamakoshi, Tokyo (Japan); Toshinori Shiraki, Tokyo (Japan); and Masami Kamaya, Yamato (Japan) | ||
| Assigned to Asahi Kasei Kabushiki Kaisha, Osaka (Japan) | ||
| Appl. No. 9/446,314 PCT Filed Apr. 28, 1999, PCT No. PCT/JP99/02304 § 371(c)(1), (2), (4) Date Dec. 20, 1999, PCT Pub. No. WO99/55752, PCT Pub. Date Nov. 04, 1999. |
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| Claims priority of application No. 10-118626 (JP), filed on Apr. 28, 1998. | ||
| Int. Cl. C08F 8/04 (2006.01); C08J 9/00 (2006.01) | ||
| U.S. Cl. 521—62 [521/64; 521/142; 521/146; 521/148; 525/98; 525/316; 528/480; 528/500] | 10 Claims |
| 2. A method for producing dried porous crumbs of a hydrogenated block copolymer, said dried porous crumbs having a water content
of 1% by weight or less,
which comprises the steps of:
(1) providing an organic solvent solution of a hydrogenated block copolymer which is obtained by hydrogenating a block copolymer
comprising (a) at least one polymer block composed mainly of aromatic vinyl monomer units and (b) at least one polymer block
composed mainly of conjugated diene monomer units, said hydrogenated block copolymer having a molecular weight of 70,000 or
more,
(2) removing said organic solvent from said solution by steam stripping, thereby obtaining an aqueous slurry containing wet
porous crumbs of said hydrogenated block copolymer,
(3) subjecting said aqueous slurry to gravity dehydration or filtration dehydration to remove water from said slurry, thereby
dehydrating said wet porous crumbs to an extent that the water content of the wet porous crumbs is in the range of from greater
than 20% to 90% by weight, wherein the removal of water from said slurry is performed without using a mechanical compression
type dehydrator or a centrifugal dehydrator, and
(4) exposing the resultant dehydrated wet porous crumbs to hot air in a hot-air dryer having a thermal conduction type heating
means or having no thermal conduction type heating means, to thereby dry said dehydrated wet porous crumbs,
wherein the temperature of the hot air in said hot-air dryer satisfies the following relationship:
80≤t1≤1.5×Mw/104+155,
wherein t1 represents the temperature (° C.) of the hot air in said hot-air dryer and Mw represents the molecular weight of said hydrogenated
block copolymer, and
wherein when said hot-air dryer has a thermal conduction type heating means, the temperature of said thermal conduction type
heating means satisfies the following relationship:
t2≤1.5×Mw/104+135,
wherein t2 represents the temperature (° C.) of said thermal conduction type heating means and Mw is as defined above.
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