US4753760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing improved pellets of hydrolyzed ethylene-vinyl acetate copolymer
Assignee: Mitsubishi Chemical Corp
•
Filing: 1986-11-05
•
Granted: 1988-06-28
•
Expires: 2006-11-05
Abstract
Abstract A process for preparing improved pellets of a hydrolyzed ethylene-vinyl acetate copolymer which comprises extruding a methanol or a water-methanol solution including a hydrolyzed ethylene-vinyl acetate copolymer and a lubricant into a coagulating liquid in the form of a strand and cutting the strand into pellets. According to the process of the present invention, the molding processability can be improved without damaging the properties of the molded articles.
Inventors
- 👤 Hiroshi Kawaguchi
- 👤 Hiroshi Takida
- 👤 Atsushi Kanai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:30
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; B; B29; B29B; B29B9/00; B29B9/02; B29B9/06; C08K; C08K5/00; C08K5/16; C08K5/20; B29K; B29K2031/00; C08J2329/00; C08J2329/02; C08J2329/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
101 words
A process for preparing improved pellets of a hydrolyzed ethylene-vinyl acetate copolymer which comprises extruding a methanol or a water-methanol solution including a hydrolyzed ethylene-vinyl acetate copolymer and 0.01 to 0.5 part by weight, based on 100 parts by weight of said copolymer, of a lubricant into a coagulating liquid in the form of a strand and cutting said strand into pellets; said lubricant being a member selected from the group consisting of a saturated fatty acid amide, an unsaturated fatty acid amide, a bis-fatty acid amide, a metal salt of fatty acid and a polyolefin having a low molecular weight.
Claim 2
Dependent Claim
101 words
A process for preparing improved pellets of a hydrolyzed ethylene-vinyl acetate copolymer which comprises extruding a methanol or a water-methanol solution including a hydrolyzed ethylene-vinyl acetate copolymer and 0.01 to 0.5 part by weight, based on 100 parts by weight of said copolymer, of a lubricant into a coagulating liquid in the form of a strand and cutting said strand into pellets; said lubricant being a member selected from the group consisting of a saturated fatty acid amide, an unsaturated fatty acid amide, a bis-fatty acid amide, a metal salt of fatty acid and a polyolefin having a low molecular weight.
Claim 3
Dependent Claim
126 words
The process of claim 1, wherein said pellets are treated with (a) an acid containing an acid group having a pka of not more than 5.0 at 25° C. and (b) a primary calcium or magnesium salt of a polybasic acid containing an acid group having a pka of not more than 3.4 at 25° C., at least one of said acid (a) and said primary salt of polybasic acid (b) having phosphate ion, so that the treated hydrolyzed ethylene-vinyl acetate copolymer has (1) a content of alkali metals of 0.001 to 0.025% by weight, (2) a molar ratio of the alkali metals to phosphate ion of 0.1 to 5 and (3) a molar ratio of calcium or magnesium to phosphate ion of 0.3 to 1.3.
Claim 4
Dependent Claim
31 words
The process of claim 1, wherein the surface of said pellets is covered with a lubricant by spraying an aqueous dispersion of the lubricant to the hydrolyzed ethylene-vinyl acetate copolymer pellets.
Claim 5
Dependent Claim
35 words
The process of claim 1, wherein the surface of said pellets is covered with a lubricant by dipping the pellets of the hydrolyzed ethylene-vinyl acetate copolymer into an aqueous dispersion of the lubricant and drying.
Claim 6
Dependent Claim
37 words
The process of claim 1, wherein the hydrolyzed ethylene-vinyl acetate copolymer has an ethylene content of 20 to 60% by mole and a degree of hydrolysis in the vinyl acetate of not less than 90% by mole.
Claim 7
Dependent Claim
22 words
The process of claim 5, wherein said hydrolyzed ethylene-vinyl acetate copolymer further contains 0.1 to 10% by mole of a copolymerizable comonomer.
Claim 8
Dependent Claim
23 words
The process of claim 1, wherein the concentration of hydrolyzed ethylene-vinyl acetate copolymer in the solution is from 10 to 50% by weight.
Claim 9
Dependent Claim
21 words
The process of claim 7, wherein the weight ratio of water and methanol in the solution is from 1:9 to 7:3.
Claim 10
Dependent Claim
31 words
The process of claim 1, wherein the coagulating liquid comprises water or a mixture of methanol and water, the methanol concentration in the mixture being from 10 to 50% by weight.
Claim 11
Dependent Claim
37 words
The process of claim 1, wherein the coagulating liquid comprises an organic solvent having a boiling point of not more than 100° C. and being compatible with methanol but not being capable of dissolving the hydrolyzed copolymer.
Claim 12
Dependent Claim
30 words
The process of claim 10, wherein the organic solvent is a material selected from the group consisting of an aromatic hydrocarbon, a ketone, an ether, and an organic acid ester.
Claim 13
Dependent Claim
12 words
The process of claim 11, wherein the organic solvent is methyl acetate.
Claim 14
Dependent Claim
22 words
The process of claim 1, wherein the solution is extruded into the coagulating liquid at a temperature of -10 to 40° C.
References Cited (Backward Citations)
US2128534A
Cited
US2338787A
Cited
US3066999A
Cited
US4164529A
Cited
JPS54149753A
Cited
US4240993A
Cited
US4320041A
Cited
US4547329A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |