Patent US4323492A successfully refreshed from Google Patents.
US4323492A
Expired / Lapsed
US
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Plasticizer containing polyvinyl alcohol granules
Assignee: Hoechst AG
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Filing: 1980-12-01
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Granted: 1982-04-06
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Expires: 2000-12-01
Abstract
Abstract For the thermoplastic processing of polyvinyl alcohol, the processing temperature must be below the decomposition temperature of the polyvinyl alcohol; this is attained by incorporating plasticizers. For preparing a plasticizer-containing granular polyvinyl alcohol wherein the plasticizer is homogeneously distributed, there is used as starting material a granular polyvinyl alcohol consisting substantially of particles having a definite diameter. The plasticizer is incorporated in the presence of a small amount of water insufficient to dissolve the polyvinyl alcohol, and the temperature is adjusted in a definite manner during the mixing operation. Simultaneous presence of fine particles of a high molecular weight organic compound soluble or dispersible in water is advantageous. The plasticizer-containing granular polyvinyl alcohol is suitable for the manufacture of any shaped articles, especially films and sheets.
Inventors
- 👤 Wolfgang Zimmermann
- 👤 Albrecht Harreus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:50
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/18; C08J3/12; C08K; C08K5/00; C08K5/0008; C08K5/0016; C08J2329/00; C08J2329/02; C08J2329/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
134 words
A process for the manufacture of plasticizer-containing, pourable, tack-free granular polyvinyl alcohol capable of thermoplastic processing comprising the steps of intensely and homogeneously mixing 100 parts by weight of dry polyvinyl alcohol granules, at least 70% of which consist of particles having a diameter of from 0.4 to 4 mm, and 5 to 50 parts by weight of a plasticizer, in the presence of an amount of water insufficient to dissolve the polyvinyl alcohol granules, and during the mixing step, raising and then lowering the temperature of the mixture for a period of time and in such a manner that the polyvinyl alcohol granules swell and temporarily agglomerate and then are broken up to form plasticizer-containing polyvinyl alcohol particles of which at least 70% by weight are from 0.8 to 4 mm in diameter.
Claim 2
Dependent Claim
134 words
A process for the manufacture of plasticizer-containing, pourable, tack-free granular polyvinyl alcohol capable of thermoplastic processing comprising the steps of intensely and homogeneously mixing 100 parts by weight of dry polyvinyl alcohol granules, at least 70% of which consist of particles having a diameter of from 0.4 to 4 mm, and 5 to 50 parts by weight of a plasticizer, in the presence of an amount of water insufficient to dissolve the polyvinyl alcohol granules, and during the mixing step, raising and then lowering the temperature of the mixture for a period of time and in such a manner that the polyvinyl alcohol granules swell and temporarily agglomerate and then are broken up to form plasticizer-containing polyvinyl alcohol particles of which at least 70% by weight are from 0.8 to 4 mm in diameter.
Claim 3
Dependent Claim
25 words
The process of claim 1, which comprises using the water in an amount of from 2 to 40 weight %, relative to the polyvinyl alcohol.
Claim 4
Dependent Claim
26 words
The process of claim 2, wherein the water is used in an amount of from 4 to 30 weight %, relative to the polyvinyl alcohol granules.
Claim 5
Dependent Claim
19 words
The process of claim 1, which comprises raising the temperature during the mixing step to a maximum 140° C.
Claim 6
Dependent Claim
23 words
The process of claim 1, which comprises lowering the temperature during the mixing operation to 40° to 70° C. after the temperature rise.
Claim 7
Dependent Claim
19 words
The process of claim 1, wherein the plasticizer is an aliphatic polyol having a boiling point above 250° C.
Claim 8
Dependent Claim
21 words
The process of claim 6, wherein the plasticizer is a bihydric to hexahydric alcohol having from 2 to 6 carbon atoms.
Claim 9
Dependent Claim
15 words
The process of claim 7, wherein the plasticizer is ethyleneglycol, glycerol, trimethylolpropane, neopentylglycol or sorbitol.
Claim 10
Dependent Claim
25 words
The process of claim 1, wherein the plasticizer is used in amounts of from 5 to 50 weight %, relative to the polyvinyl alcohol granules.
Claim 11
Dependent Claim
25 words
The process of claim 9, wherein the plasticizer is used in amounts of from 10 to 30 weight %, relative to the polyvinyl alcohol granules.
Claim 12
Dependent Claim
31 words
The process of claim 1, wherein in temperature is raised to a range of from 100° to 130° C. and then lowered to a range of from 40° to 70° C.
Claim 13
Dependent Claim
19 words
The process of claim 11, wherein the temperature is lowered to a range of from 35° to 60° C.
Claim 14
Dependent Claim
34 words
The process of claim 1, wherein in the mixing step, a fine-particle high molecular weight organic compound which is soluble or dispersible in water is mixed with the polyvinyl alcohol granules and the plasticizer.
Claim 15
Dependent Claim
34 words
The process of claim 13, wherein the high molecular weight organic compound is used in an amount of from 1 to 15 parts by weight and has a particle diameter not exceeding 300 μm.
Claim 16
Dependent Claim
26 words
The process of claim 13, wherein the high molecular weight organic compound is selected from the group consisting of a polyvinyl ester and a polyvinyl acetal.
Claim 17
Dependent Claim
25 words
The process of claim 13, which comprises using the high molecular weight organic compound in an amount of from 5 to 20 parts by weight.
Claim 18
Dependent Claim
27 words
The process of claim 13, which comprises using as the high molecular weight compound a compound having an average polymerization degree (average weight) of at least 200.
Claim 19
Dependent Claim
20 words
The process of claim 13, which comprises using the high molecular weight organic compound in the form of a dispersion.
Claim 20
Dependent Claim
26 words
The process of claim 18, wherein the disperse high molecular weight organic compound has a particle diameter in the range of from 0.1 to 10 μm.
Claim 21
Dependent Claim
49 words
The process of claim 13, wherein in the mixing step auxiliaries including lubricants, heat stabilizers and dyestuffs in amounts up to a maximum of 3 weight %, relative to the polyvinyl alcohol granules, are mixed with the polyvinyl alcohol granules, the plasticizer and the high molecular weight organic compound.
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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) | 1985-04-05 | 1985-10-05 | 1986-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-05 | 1989-10-05 | 1990-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-05 | 1993-10-05 | 1994-04-06 | $7700.00 | Window Closed / Lapsed |