US4069278A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of making a high melt viscosity block co-polyester
Assignee: General Electric Co
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Filing: 1975-04-01
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Granted: 1978-01-17
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Expires: 1995-04-01
Abstract
Abstract A novel process is disclosed for preparing a high melt viscosity block co-polyester of at least two different linear polyesters. The process comprises melt blending the polyesters and, thereafter, subjecting the melt blended polyesters to a temperature of 10°-50° C. below the melting point of the lowest melting ingredient in the blend until the melt viscosity has increased to at least 10,000 poises at a temperature 10°-15° C. above the melting point of the blend.
Inventors
- 👤 Willem Frederik Hendrik Borman
- 👤 Donald Irving Craft
- 👤 Mortor Kramer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:27
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/005; C08L; C08L67/00; C08J2367/00; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/582
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
142 words
A method of preparing a high melt viscosity thermoplastic polyester blend of at least two different polyesters having repeating units of the formula: ##STR2## wherein n and m are positive integers between 1 and 10; said method consisting essentially of melt blending at least two low to medium melt viscosity linear polyesters, wherein at least one of the low to medium viscosity linear polyesters is a branched co-polyester that includes from 0.01 to 5 mole percent based on the terephthalate units, of units of branching component which contains at least three ester-forming groups, and thereafter subjecting the melt blended polyesters to a temperature of 10°-50° C. below the melting point of the lowest melting ingredient in the blend until the melt viscosity has increased to at least 10,000 poises at a temperature of 10°-15° C. above the melting point of the blend.
Claim 2
Independent Claim
142 words
A method of preparing a high melt viscosity thermoplastic polyester blend of at least two different polyesters having repeating units of the formula: ##STR2## wherein n and m are positive integers between 1 and 10; said method consisting essentially of melt blending at least two low to medium melt viscosity linear polyesters, wherein at least one of the low to medium viscosity linear polyesters is a branched co-polyester that includes from 0.01 to 5 mole percent based on the terephthalate units, of units of branching component which contains at least three ester-forming groups, and thereafter subjecting the melt blended polyesters to a temperature of 10°-50° C. below the melting point of the lowest melting ingredient in the blend until the melt viscosity has increased to at least 10,000 poises at a temperature of 10°-15° C. above the melting point of the blend.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the melt viscosity is increased to from 25,000 - 75,000 poises at a temperature 10°-15° C. above the melting point of the blend.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the low to medium melt viscosity linear polyesters are selected from the group consisting of polyethylene terephthalate, polybutylene terephthalate and poly(ethylene isophthalate) and poly(1,4-butylene isophthalate).
Claim 5
Dependent Claim
37 words
The method of claim 1 wherein said melt blended polyesters are subjected to a temperature of 10°-50° C. below the melting point of the lowest melting ingredient in the blend in the presence of an inert atmosphere.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein said inert atmosphere contains a minor amount of alkylene glycol vapor.
Claim 7
Dependent Claim
24 words
The method of claim 5 wherein said glycol vapor comprises a mixture of glycols that correspond to the glycol component of the linear polyester.
Claim 8
Dependent Claim
11 words
The method of claim 5 wherein the inert atmosphere is nitrogen.
Claim 9
Dependent Claim
11 words
The method of claim 1 wherein the branching component is polyol.
Claim 10
Dependent Claim
11 words
The method of claim 8 wherein the branching component is trimethylolpropane.
Claim 11
Dependent Claim
11 words
The method of claim 8 wherein said branching component is pentaerythritol.
Claim 12
Dependent Claim
22 words
The method of claim 1 wherein said branching component is a tricarboxylic acid, a tetracarboxylic acid or a lower alkyl ester thereof.
Claim 13
Independent Claim
87 words
A method of preparing a high melt viscosity thermoplastic blend of polyethylene terephthalate and polybutylene terephthalate, said method comprising melt blending a low to medium melt viscosity polybutylene terephthalate with a low to medium melt viscosity polyethylene terephthalate and thereafter subjecting the melt blended polyesters to a temperature of 10°-50° C. below the melting point of the lowest melting polyester in the blend until the melt viscosity has increased to a viscosity of 25,000-75,000 poises at a temperature 10°-15° C. above the melting point of the blend.
Claim 14
Independent Claim
87 words
A method of preparing a high melt viscosity thermoplastic blend of polyethylene terephthalate and polybutylene terephthalate, said method comprising melt blending a low to medium melt viscosity polybutylene terephthalate with a low to medium melt viscosity polyethylene terephthalate and thereafter subjecting the melt blended polyesters to a temperature of 10°-50° C. below the melting point of the lowest melting polyester in the blend until the melt viscosity has increased to a viscosity of 25,000-75,000 poises at a temperature 10°-15° C. above the melting point of the blend.
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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) | 1981-01-16 | 1981-07-18 | 1982-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-16 | 1985-07-18 | 1986-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-16 | 1989-07-18 | 1990-01-17 | $7700.00 | Window Closed / Lapsed |