Patent US4889673A successfully refreshed from Google Patents.
US4889673A
Expired / Lapsed
US
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Process for preparing polyvinyl chloride material used for extrusion molding
Assignee: Toyoda Gosei Co Ltd
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Filing: 1988-12-06
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Granted: 1989-12-26
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Expires: 2008-12-06
Abstract
Abstract Preparing process for polyvinyl chloride material used for extrusion molding suitable to high speed extrusion includes a step of dry blending a blend prepared by blending polyvinyl chloride (polymer) compounded with plasticizers stabilizers and other auxiliary materials while controlling the temperature for the blend within a range from room temperature to 165° C. and a step of kneading and pelletizing the blend after the dry blending step while controlling the temperature for the blend to lower than 165° C. The polyvinyl chloride used is a suspension polymerizate capable of satisfying the condition that the retention ratio on 80 mesh screen (ASTM: E11-58T) is less than 1%.
Inventors
- 👤 Masahiro Takimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:16
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/20; C08J3/203; C08J2327/00; C08J2327/02; C08J2327/04; C08J2327/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
112 words
A process for preparing polyvinyl chloride material used for extrusion molding comprising: (1) a step of dry blending a blend prepared by blending polyvinyl chloride (polymer) with plasticizers and stabilizers, and optionally with colorants while controlling a temperature for the blend within a range from 20° C. to 165° C., and (2) a step of kneading and pelletizing the blend after the dry blending step while controlling a temperature for the blend within a range from 120° C. to 165° C., in which the polyvinyl chloride used is a product by suspension polymerization capable of satisfying the condition that the retention ratio on 80 mesh screen (ASTM: E11-58T) is less than 1%.
Claim 2
Dependent Claim
112 words
A process for preparing polyvinyl chloride material used for extrusion molding comprising: (1) a step of dry blending a blend prepared by blending polyvinyl chloride (polymer) with plasticizers and stabilizers, and optionally with colorants while controlling a temperature for the blend within a range from 20° C. to 165° C., and (2) a step of kneading and pelletizing the blend after the dry blending step while controlling a temperature for the blend within a range from 120° C. to 165° C., in which the polyvinyl chloride used is a product by suspension polymerization capable of satisfying the condition that the retention ratio on 80 mesh screen (ASTM: E11-58T) is less than 1%.
Claim 3
Dependent Claim
38 words
A process for preparing polyvinyl chloride material used for extrusion molding as defined in claim 1, wherein the temperature for the blend in the dry blending step is controlled within a range from 80° C. to 110° C.
References Cited (Backward Citations)
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US3562373A
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US3919164A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |