Patent US4253901A successfully refreshed from Google Patents.
US4253901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of heat sealing employing a hot tack adhesive
Assignee: Dow Chemical Co
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Filing: 1977-07-01
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Granted: 1981-03-03
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Expires: 1997-07-01
Abstract
Abstract Normally solid heat-activatable thermoplastic adhesives having improved hot tack strength at heat-seal temperatures are composed essentially of copolymers of ethylene with acrylic acid or methacrylic acid having standard melt flow values from about 1 to about 3 dg/min., and are especially useful as heat-seal coating or layer on substrates for packaging.
Inventors
- 👤 R. Corbin Aslakson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:48
CPC Classifications
C; C09; C09J; C09J123/00; C09J123/02; C09J123/04; C09J123/08; Y; Y10; Y10S; Y10S526/00; Y10S526/935; Y10S526/94; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31909
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
160 words
In a method of forming a seal or bond between facing substrate surfaces having a heat-activatable thermoplastic adhesive material therebetween by applying pressure sufficient to maintain intimate contact between the adhesive material and the substrate surfaces and heating to a temperature in the heat-seal range to activate the thermoplastic adhesive material in the area to be sealed or bonded, wherein the resulting seal or bond is subjected to force tending to separate the substrate surfaces while the adhesive material therebetween is at a temperature in the heat-seal range, the improvement wherein the heat-activatable thermoplastic adhesive material is composed essentially of a copolymer of ethylene and at least one acid selected from acrylic acid and methacrylic acid, which copolymer contains from about 6 to about 10 weight percent of said acid based on the copolymer and has melt flow value in the range from about 1 to about 3 dg/min., whereby the resulting seal or bond has high hot tack strength.
Claim 2
Dependent Claim
160 words
In a method of forming a seal or bond between facing substrate surfaces having a heat-activatable thermoplastic adhesive material therebetween by applying pressure sufficient to maintain intimate contact between the adhesive material and the substrate surfaces and heating to a temperature in the heat-seal range to activate the thermoplastic adhesive material in the area to be sealed or bonded, wherein the resulting seal or bond is subjected to force tending to separate the substrate surfaces while the adhesive material therebetween is at a temperature in the heat-seal range, the improvement wherein the heat-activatable thermoplastic adhesive material is composed essentially of a copolymer of ethylene and at least one acid selected from acrylic acid and methacrylic acid, which copolymer contains from about 6 to about 10 weight percent of said acid based on the copolymer and has melt flow value in the range from about 1 to about 3 dg/min., whereby the resulting seal or bond has high hot tack strength.
Claim 3
Dependent Claim
52 words
The improvement according to claim 1 wherein the heat-activatable thermoplastic adhesive material is composed essentially of a copolymer of ethylene and from about 7 to about 9 weight percent acrylic acid based on the copolymer, and the copolymer has melt flow value in the range from about 1.5 to about 2.5 dg/min.
Claim 4
Dependent Claim
29 words
The improvement according to claim 1 wherein the heat-activatable thermoplastic copolymer adhesive material is an adherent heat-seal layer or coating on at least one of the facing substrate surfaces.
Claim 5
Dependent Claim
42 words
The improvement according to claim 1 wherein the heat-activatable thermoplastic copolymer adhesive material is an adherent heat-seal layer or coating on each of two facing substrate surfaces and the seal or bond is formed by heat-seal-bonding the copolymer adhesive material to itself.
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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) | 1984-03-02 | 1984-09-01 | 1985-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-02 | 1988-09-01 | 1989-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-02 | 1992-09-01 | 1993-03-03 | $7700.00 | Window Closed / Lapsed |