US3926918A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing polyvinyl acetal
Assignee: Sekisui Chemical Co Ltd
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Filing: 1973-12-27
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Granted: 1975-12-16
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Expires: 1993-12-27
Abstract
Abstract A process for preparing polyvinyl acetals by condensing polyvinyl alcohol with an aldehyde in the aqueous phase in the presence of an acid catalyst, wherein after the reaction system is maintained at a temperature of not more than 20*C. to precipitate the reaction product, the reaction system is heated to a temperature of at least 30*C. and the reaction is continued at this temperature.
Inventors
- 👤 Yutaka Shibata
- 👤 Yoshiaki Kodera
- 👤 Mitsuru Tanaka
- 👤 Fumio Kamiyama
- 👤 Nakatan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:12
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/28
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
32 words
A PROCESS FOR PREPARING POLYVINYL ACETALS BY CONDENSING POLYVINYL ALCOHOL WITH AN ALDEHYDE IN THEAQUEOUS PHASE IN TH PRESENCE OF A CATALYTIC AOUNT OF AN ACID CATALYST WHICH COMPRISES THE FOLLOWING STEPS:
Claim 2
Dependent Claim
32 words
A PROCESS FOR PREPARING POLYVINYL ACETALS BY CONDENSING POLYVINYL ALCOHOL WITH AN ALDEHYDE IN THEAQUEOUS PHASE IN TH PRESENCE OF A CATALYTIC AOUNT OF AN ACID CATALYST WHICH COMPRISES THE FOLLOWING STEPS:
Claim 3
Dependent Claim
77 words
REACTING THE POLYVINYL ALCOHOL WITH NOT MORE THAN 0.25 MOL PER 1.0 MOL OF THE -CH2-CHOH- BOND OF THE POLYVINYL ALCOHOL, OF AN ALDEHYDE AT A TEMPERATURE IN EXCESS OF 20*C. SO AS NOT TO PRECIPITATE THE REACTION PRODUCT, 2. COOLING THE REACTION SYSTEM AT A TEMPERATURE OF NOT MORE THAN 20*C. AND FURTHER ADDING AN ALDEHYDE WHILE MAINTAINING THE REACTION SYSTEM AT A TEMPERATURE OF NOT MORE THAN 20*C. THEREBY TO PRECIPITATE THE REACTION PRODUCT, AND
Claim 4
Dependent Claim
77 words
REACTING THE POLYVINYL ALCOHOL WITH NOT MORE THAN 0.25 MOL PER 1.0 MOL OF THE -CH2-CHOH- BOND OF THE POLYVINYL ALCOHOL, OF AN ALDEHYDE AT A TEMPERATURE IN EXCESS OF 20*C. SO AS NOT TO PRECIPITATE THE REACTION PRODUCT, 2. COOLING THE REACTION SYSTEM AT A TEMPERATURE OF NOT MORE THAN 20*C. AND FURTHER ADDING AN ALDEHYDE WHILE MAINTAINING THE REACTION SYSTEM AT A TEMPERATURE OF NOT MORE THAN 20*C. THEREBY TO PRECIPITATE THE REACTION PRODUCT, AND
Claim 5
Dependent Claim
37 words
cooling the reaction system at a temperature of not more than 20*C. and further adding an aldehyde while maintaining the reaction system at a temperature of not more than 20*C. thereby to precipitate the reaction product, and
Claim 6
Dependent Claim
37 words
cooling the reaction system at a temperature of not more than 20*C. and further adding an aldehyde while maintaining the reaction system at a temperature of not more than 20*C. thereby to precipitate the reaction product, and
Claim 7
Dependent Claim
29 words
The process of claim 1 wherein the time during which the reaction system is maintained at a temperature of not more than 20*C. is not more than 3 hours.
Claim 8
Dependent Claim
23 words
The process of claim 1 wherein the reaction system after the precipitation is heated at a rate of 5* to 20*C. per hour.
Claim 9
Dependent Claim
23 words
heating the reaction system to a temperature of at least 30*C. and continuing the reaction at this temperature for at least 1 hour.
Claim 10
Dependent Claim
23 words
heating the reaction system to a temperature of at least 30*C. and continuing the reaction at this temperature for at least 1 hour.
Claim 11
Dependent Claim
22 words
HEATING THEREACTION SYSTEM TO A TEMPERATURE OF AT LEAST 30*C. AND CONTINUING THE REACTION AT THIS TEMPERATURE FOR AT LEAST 1 HOUR.
Claim 12
Dependent Claim
22 words
HEATING THEREACTION SYSTEM TO A TEMPERATURE OF AT LEAST 30*C. AND CONTINUING THE REACTION AT THIS TEMPERATURE FOR AT LEAST 1 HOUR.
Claim 13
Dependent Claim
27 words
The process of claim 1 wherein the reaction system is maintained at a temperature of not more than 20*C. but above -6*C. to precipitate the reaction product.
Claim 14
Dependent Claim
26 words
The process of claim 1 wherein the reaction system is heated to a tempeature of 30* to 60*C., and the reaction is continued at this temperature.
Claim 15
Dependent Claim
12 words
The process of claim 1 wherein said acid catalyst is hydrochloric acid.
Claim 16
Dependent Claim
30 words
The process of claim 1 wherein the polyvinyl alcohol has a degree of polymerization of 200 to 3000 and contains not more than 10 mol % of residual acyl groups.
Claim 17
Dependent Claim
22 words
The process of claim 1 wherein the concentration of the aqueous solution of polyvinyl alcohol is 5 to 20 % by weight.
Claim 18
Dependent Claim
10 words
The process of claim 1 wherein the aldehyde is butyraldehyde.
Claim 19
Dependent Claim
15 words
The process of claim 1 wherein the aldehyde is a combination of butyraldehyde and acetaldehyde.
Claim 20
Dependent Claim
15 words
The process of claim 1 wherein the aldehyde is a combination of butyraldehyde and formaldehyde.
Claim 21
Dependent Claim
27 words
The process of claim 1 wherein the amount of the aldehyde is 0.25 to 1.0 mol per 1.0 mol of the -CH2-CHOH- bond of the polyvinyl alcohol.
Claim 22
Dependent Claim
139 words
A process for preparing polyvinyl acetals by condensing polyvinyl alcohol with an aldehyde in the aqueous phase in the presence of a catalytic amount of an acid catalyst, which comprises reacting the polyvinyl alcohol with not more than 0.25 mol per 1.0 mol of the -CH2-CHOH- bond of the polyvinyl alcohol, of an aldehyde at a temperature in excess of 20*C. so as not to precipitate the reaction product, then maintaining the reaction system at a temperature of not more than 20*C., further adding an aldehyde to precipitate the reaction product, maintaining the reaction system within 3 hours at a temperature of not more than 20*C., then heating the reaction system at a rate of 5* to 20*C. per hour to a temperature of 30* to 60*C., and continuing the reaction at this temperature for at least 1 hour.
Claim 23
Dependent Claim
139 words
A process for preparing polyvinyl acetals by condensing polyvinyl alcohol with an aldehyde in the aqueous phase in the presence of a catalytic amount of an acid catalyst, which comprises reacting the polyvinyl alcohol with not more than 0.25 mol per 1.0 mol of the -CH2-CHOH- bond of the polyvinyl alcohol, of an aldehyde at a temperature in excess of 20*C. so as not to precipitate the reaction product, then maintaining the reaction system at a temperature of not more than 20*C., further adding an aldehyde to precipitate the reaction product, maintaining the reaction system within 3 hours at a temperature of not more than 20*C., then heating the reaction system at a rate of 5* to 20*C. per hour to a temperature of 30* to 60*C., and continuing the reaction at this temperature for at least 1 hour.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |