US4849256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for plasticizing polyvinyl alcohol resin
Assignee: Clorox Co
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Filing: 1988-03-11
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Granted: 1989-07-18
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Expires: 2008-03-11
Abstract
Abstract An improved process for the production of a plasticizer containing dry, flowable polyvinyl alcohol (PVA) resin blend capable of thermoplastic processing. The process provides for the incorporation of plasticizers in an intimate contact with the PVA resin without heating, cooling, or extended drying steps. Specifically, PVA resin granules having an appropriately small particle size distribution are spray-coated with a liquid plasticizer medium, and then mixed with a dry, fine powder coating medium to produce a flowable, dry plasticized PVA blend. Additional components, such as antioxidants, dyes, and antiblocking agents, may also be incorporated into the finished product.
Inventors
- 👤 Garry F. Newman
- 👤 Dean F. Carson
- 👤 Steve B. Cherry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:16
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; C08J3/124; C08J3/18; C08J2329/00; C08J2329/02; C08J2329/04; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/254
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
139 words
A process for the production of a dry, flowable polyvinyl alcohol (PVA) resin blend capable of thermoplastic processing comprising the steps of: (a) selecting a PVA resin having a particle size distribution such that at least 80% of the resin consists of particles having a diameter less than about 500 microns; (b) coating the PVA resin with a liquid plasticizer medium in an amount sufficient to plasticize the PVA resin, to produce PVA/plasticizer granules; and (c) mixing the PVA/plasticizer granules with a dry powder coating medium to produce a dry, fine plasticized PVA blend; wherein the coating and mixing steps are conducted at a temperature of less than about 105° F., and wherein the dry, plasticized PVA blend has a particle size distribution such that at least about 90% of the blend passes through a 1/4 inch mesh screen.
Claim 2
Dependent Claim
139 words
A process for the production of a dry, flowable polyvinyl alcohol (PVA) resin blend capable of thermoplastic processing comprising the steps of: (a) selecting a PVA resin having a particle size distribution such that at least 80% of the resin consists of particles having a diameter less than about 500 microns; (b) coating the PVA resin with a liquid plasticizer medium in an amount sufficient to plasticize the PVA resin, to produce PVA/plasticizer granules; and (c) mixing the PVA/plasticizer granules with a dry powder coating medium to produce a dry, fine plasticized PVA blend; wherein the coating and mixing steps are conducted at a temperature of less than about 105° F., and wherein the dry, plasticized PVA blend has a particle size distribution such that at least about 90% of the blend passes through a 1/4 inch mesh screen.
Claim 3
Dependent Claim
23 words
A process according to claim 1 wherein at least 95% of the PVA resin particles have a diameter less than about 500 microns.
Claim 4
Dependent Claim
24 words
A process according to claim 1 wherein the PVA comprises from about 60 to about 85 weight percent of the dry, plasticized PVA blend.
Claim 5
Dependent Claim
28 words
A process according to claim 1 wherein the liquid plasticizer medium is selected from the group consisting of water, glycerin, trimethylolpropane, neopentyl glycol, polyethylene glycol, and mixtures thereof.
Claim 6
Dependent Claim
25 words
A process according to claim 1 wherein the liquid plasticizer medium comprises from about 10 to about 20 percent by weight of the PVA/plasticizer blend.
Claim 7
Dependent Claim
28 words
A process according to claim 1 wherein the dry, fine powder coating medium comprises from about 1.0 to about 10.0 weight percent of the dry plasticized PVA blend.
Claim 8
Dependent Claim
30 words
A process according to claim 6 wherein the dry, fine powder coating medium is selected from the group consisting of magnesium stearate, potassium stearate, sorbitol, fructose, starch, and mixtures thereof.
Claim 9
Dependent Claim
17 words
A process according to claim 1 wherein the dry, fine powder coating medium is an impalpable powder.
Claim 10
Dependent Claim
33 words
A process according to claim 1 and further including from about 0 to 10 weight percent of an additive, selected from the group consisting of antioxidants, antiblocking agents, borate scavengers, and mixtures thereof.
Claim 11
Dependent Claim
17 words
A process according to claim 1 wherein the liquid plasticizer is spray coated onto the PVA resin.
Claim 12
Dependent Claim
27 words
A process according to claim 1 wherein at least 90% of the dry, plasticized PVA blend comprises granules having a diameter of less than about 1/4 inch.
Claim 13
Dependent Claim
148 words
In a process for producing a dry, flowable PVA resin blend capable of thermoplastic processing of the type wherein a quantity of PVA resin particles are admixed with a plasticizer, the improvement comprising (a) selecting a quantity of PVA resin having a resin particle size distribution such that at least about 80% of the resin consists of particles having a diameter of about 500 microns or less; (b) coating the particles with a plasticizingeffective amount of a liquid plasticizer medium to produce a quantity of PVA/plasticizer granules; and (c) mixing the PVA/plasticizer granules with a coating-effective amount of a dry, fine powder coating medium to produce a dry, flowable, plasticized PVA blend having a distribution of PVA particle sizes such that at least 90% passes through a 1/4 inch screen; and wherein the coating and mixing steps are conducted at a temperature of less than about 105° F.
Claim 14
Dependent Claim
148 words
In a process for producing a dry, flowable PVA resin blend capable of thermoplastic processing of the type wherein a quantity of PVA resin particles are admixed with a plasticizer, the improvement comprising (a) selecting a quantity of PVA resin having a resin particle size distribution such that at least about 80% of the resin consists of particles having a diameter of about 500 microns or less; (b) coating the particles with a plasticizingeffective amount of a liquid plasticizer medium to produce a quantity of PVA/plasticizer granules; and (c) mixing the PVA/plasticizer granules with a coating-effective amount of a dry, fine powder coating medium to produce a dry, flowable, plasticized PVA blend having a distribution of PVA particle sizes such that at least 90% passes through a 1/4 inch screen; and wherein the coating and mixing steps are conducted at a temperature of less than about 105° F.
Claim 15
Dependent Claim
26 words
The process according to claim 12 wherein the PVA resin comprises from about 60 to about 85 percent by weight of the dry, plasticized PVA blend.
Claim 16
Dependent Claim
26 words
The process according to claim 12 wherein the plasticizer is selected from the group consisting of water, glycerin, trimethylolpropane, neopentyl glycol, polyethylene glycol, and mixtures thereof.
Claim 17
Dependent Claim
26 words
The process according to claim 12 wherein the plasticizer comprises from about 10 to about 20 percent by weight percent of the dry, plasticized PVA blend.
Claim 18
Dependent Claim
27 words
The process according to claim 12 wherein the dry, fine coating medium comprises from about 1.0 to about 10.0 weight percent of the dry, plasticized PVA blend.
Claim 19
Dependent Claim
29 words
The process according to claim 12 wherein the dry, fine coating medium is selected from the group consisting of magnesium stearate, potassium stearate, sorbitol, fructose, starch, and mixtures thereof.
Claim 20
Dependent Claim
16 words
The process according to claim 17 wherein the dry, fine coating medium is an impalpable powder.
Claim 21
Dependent Claim
33 words
The process according to claim 12 further comprising from about 0 to about 10 weight percent of an additive selected from the group consisting of antioxidants, antiblocking agents, borate scavengers, and mixtures thereof.
Claim 22
Dependent Claim
17 words
The process according to claim 12 wherein the liquid plasticizer medium is spray-coated onto the PVA resin.
Claim 23
Dependent Claim
27 words
The process according to claim 12 wherein at least 90% of the dry, plasticized PVA blend comprises granules having a diameter of less than about 1/4 inch.
References Cited (Backward Citations)
US2864784A
Cited
US3121701A
Cited
US3365413A
Cited
US3425979A
Cited
US3607812A
Cited
US4171428A
Cited
US3882196A
Cited
GB1410744A
Cited
US3991225A
Cited
US3997489A
Cited
US3985702A
Cited
US4119604A
Cited
US4155971A
Cited
US4156047A
Cited
US4060510A
Cited
US4323492A
Cited
US4242384A
Cited
EP0157612A2
Cited
US4608187A
Cited
US4608187B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-17 | 1993-01-16 | 1993-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-17 | 1997-01-16 | 1997-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-17 | 2001-01-16 | 2001-07-18 | $7700.00 | Window Closed / Lapsed |