US4287308A
Expired / Lapsed
US
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Process for preparing a thermo-expandable microspheres
Assignee: Matsumoto Yushi-Seiyaku Co Ltd
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Filing: 1980-06-10
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Granted: 1981-09-01
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Expires: 2000-06-10
Abstract
Abstract Microspheres, the blowing agent of which is microencapsulated with a thermoplastics having an acrylonitrile moiety, are prepared. Acrylonitrile monomer remaining therein is eliminated from the microspheres by cyanoethylation. The microspheres have an excellent solvent-resistance and an expansibility hardly changeable with time but no harmfulness attributed to the acrylonitrile monomer.
Inventors
- 👤 Nobukazu Nakayama
- 👤 Sueo Kida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:32
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
61 words
A process for preparing a thermo-expandable microsphere substantially free of acrylonitrile monomer which comprises microencapsulating a blowing agent with a thermoplastic polymer having an acrylonitrile moiety as one of ingredients, wherein the blowing agent becomes gaseous below a softening temperature of the thermoplastic polymer, and subjecting the microencapsulated product to cyanoethylation to eliminate the acrylonitrile monomer remaining in the microencapsulated product.
Claim 2
Dependent Claim
61 words
A process for preparing a thermo-expandable microsphere substantially free of acrylonitrile monomer which comprises microencapsulating a blowing agent with a thermoplastic polymer having an acrylonitrile moiety as one of ingredients, wherein the blowing agent becomes gaseous below a softening temperature of the thermoplastic polymer, and subjecting the microencapsulated product to cyanoethylation to eliminate the acrylonitrile monomer remaining in the microencapsulated product.
Claim 3
Dependent Claim
21 words
The process according to claim 1, wherein the thermoplastic polymer contains at least 15 percent by weight of the acrylonitrile moiety.
Claim 4
Dependent Claim
45 words
The process according to claim 1, wherein the thermoplastic polymer contains at least 15 percent by weight of the acrylonitrile moiety, 30 to 80 percent by weight of a vinylidene chloride moiety and 0.1 to 1.0 percent by weight of a cross-linkable vinyl monomer moiety.
Claim 5
Dependent Claim
24 words
The process according to claim 1, wherein the cyanoethylation is carried out at 30° to 80° C. under 2 to 10 Kg/cm 2 .
Claim 6
Dependent Claim
33 words
The process according to claim 1, wherein the cyanoethylation is effected using a compound selected from the group consisting of primary amine, secondary amine, primary alkanolamine, secondary alkanolamine, secondary alkylalkanolamine and sodium sulfide.
References Cited (Backward Citations)
US3615972A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-08-31 | 1985-03-02 | 1985-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-31 | 1989-03-02 | 1989-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-31 | 1993-03-02 | 1993-09-01 | $7700.00 | Window Closed / Lapsed |