US4755337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for surface treating a polyester film
Assignee: Teijin Ltd
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Filing: 1986-04-08
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Granted: 1988-07-05
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Expires: 2006-04-08
Abstract
Abstract A polyester film having on at least one surface thereof a primer layer comprising a crosslinked product of a polyurethane having at least one functional group selected from a carboxyl group, a sulfo group, a hemisulfate group, and salts of these groups and a polyepoxy compound. The polyester film having a primer layer can be produced by coating an aqueous primer coating composition comprising a polyurethane having at least one of a carboxylic acid salt group, a sulfonic acid salt group and a hemisulfate salt group on at least one surface of a polyester film before its crystallization and orientation are completed, and thereafter completing the crystallization and orientation by subjecting the coated film to drying, stretching and heat-treatment, and is useful as a base film for magnetic recording media.
Inventors
- 👤 Teruo Takahashi
- 👤 Hirofumi Yoshikawa
- 👤 Sadayoshi Miura
- 👤 Tamaki Kanai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:09
CPC Classifications
C; C08; C08G; C08G18/00; C08G18/06; C08G18/08; C08G18/0804; C08G18/0819; C08G18/83; C08G18/831; C08J; C08J7/00; C08J7/04; C08J7/0427; C08J7/043; C09; C09D; C09D175/00; C09D175/04; G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73923; G11B5/73927; G11B5/73931; G11B5/73935; G11B5/74; G11B5/82; G11B5/825; C08J2367/00; C08J2367/02; C08J2475/00; H; H05; H05K; H05K2203/00; H05K2203/12; H05K2203/122; H05K2203/124
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
94 words
A process for producing a polyester film having a primer layer, which comprises coating a crosslinkable aqueous primer coating composition comprising a polyurethane having (0.5-10) ×10 -4 gram equivalent/gram of resin of at least one of a carboxylic acid salt group, a sulfonic acid salt group and a hemisulfate salt group and a polyepoxy compound as a crosslinking agent on at least one surface of a polyester film before its crystallization and orientation are completed, and thereafter completing the crystallization and orientation by subjecting the coated film to a drying, stretching and heating treatment.
Claim 2
Dependent Claim
94 words
A process for producing a polyester film having a primer layer, which comprises coating a crosslinkable aqueous primer coating composition comprising a polyurethane having (0.5-10) ×10 -4 gram equivalent/gram of resin of at least one of a carboxylic acid salt group, a sulfonic acid salt group and a hemisulfate salt group and a polyepoxy compound as a crosslinking agent on at least one surface of a polyester film before its crystallization and orientation are completed, and thereafter completing the crystallization and orientation by subjecting the coated film to a drying, stretching and heating treatment.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the polyurethane has a number average molecular weight in the range of 10,000 to 500,000.
Claim 4
Dependent Claim
30 words
The process of claim 1 wherein the polyurethane is a polyurethane obtained by introducing the functional group into a polyurethane formed from an aliphatic polyester polyol and an aliphatic diisocyanate.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the polyurethane has the carboxyl acid salt group.
Claim 6
Dependent Claim
26 words
The process of claim 4 wherein the carboxylic acid salt group is a group of a salt formed between carboxylic acid and an aliphatic tertiary amine.
Claim 7
Dependent Claim
15 words
The process of claim 1 wherein the polyepoxy compound is a water-soluble aliphatic polyepoxy compound.
Claim 8
Dependent Claim
20 words
The process of claim 1 wherein the polyepoxy compound has an epoxy equivalent in the range of 100 to 600.
Claim 9
Dependent Claim
12 words
The process of claim 1 the polyepoxy compound is selected from ##STR3##
Claim 10
Dependent Claim
29 words
The process of claim 1 wherein the polyepoxy compound is used in an amount of 1 to 40 parts by weight per 100 parts by weight of the polyurethane.
Claim 11
Dependent Claim
16 words
The process of claim 1 wherein the aqueous primer coating composition further comprises a reaction-promoting compound.
Claim 12
Dependent Claim
21 words
The process of claim 10 wherein the reaction-promoting compound is selected from phenolic tertiary amine compounds, imidazole compounds and 1,8-diazo-bicyclo [5,4,0]undecene-7.
Claim 13
Dependent Claim
30 words
The process of claim 11 wherein the reaction-promoting compound is used in an amount of 1 to 60 parts by weight per 100 parts by weight of the polyepoxy compound.
Claim 14
Dependent Claim
42 words
The process of claim 1 wherein the polyester film contains fine particles of titanium dioxide having an average particle diameter of not more than 0.5 micrometer and has a center line average surface roughness (Ra) in the range of 0.004 to 0.02.
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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) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |