US5225470A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acrylic hot melt pressure sensitive adhesive compositions
Assignee: Cytec Industries Inc
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Filing: 1991-02-22
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Granted: 1993-07-06
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Expires: 2011-02-22
Abstract
Abstract Acrylic hot melt pressure sensitive adhesive compositions having a good balance of tack, peel and creep resistance at ambient temperature combined with optical clarity and desirable melt viscosity at elevated temperatures are prepared by copolymerizing acrylic and methacrylic alkyl esters of a non-tertiary alcohol or optionally acids with polymerizable poly methacrylate based macromonomers. The resulting acrylic copolymer has a graft or comb structure in which the acrylic backbone has a low Tg and the pendant macromonomer side chains have a Tg above room temperature. Compounding those acrylic copolymers with tackifiers and plasticizers dramatically improves the balance of pressure sensitive adhesive properties while lowering melt viscosity into a desirable range. The invention provides significant property enhancements even for acrylic copolymers having poor initial peel and shear adhesive properties. Preferably, the acrylic backbone is tailored by judicious selection of acrylic comonomers to allow compounding with several high performance hydrogenated tackifiers and plasticizers that provide water white and clear adhesive formulations while ensuring long term color stability, weatherability and general durability.
Inventors
- 👤 Paul A. Mancinelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:04
CPC Classifications
C; C09; C09J; C09J155/00; C09J155/005; C08; C08F; C08F290/00; C08F290/02; C08F290/04; C08F290/046; C09J7/00; C09J7/30; C09J7/38; C09J7/381; C09J7/385; Y; Y10; Y10T; Y10T442/00; Y10T442/20; Y10T442/2738; Y10T442/2754
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
180 words
An acrylic hot melt pressure sensitive adhesive composition comprising (a) 30 to 90% by weight of a thermoplastic comb copolymer of (i) 2-35% by weight, based on the thermoplastic copolymer, of a macromonomer of the general formula X-(Y)n-Z wherein X is a reactive end group capable of copolymerization under free radical conditions with acrylic comonomers to afford the comb copolymer having pendant macromonomer side chains along an acrylic backbone; Y is a linking group in which n is zero or one; and Z is a poly(methacrylate) based a polymeric moiety having a T g greater than 20° C. and a weight average molecular weight of about from 2,000 to 35,000 and being substantially unreactive under copolymerization conditions; and (ii) 65 to 98% by weight, based on the thermoplastic copolymer, of one or more monomers selected from the group consisting of monomeric acrylic or methacrylic acid ester of a non-tertiary alcohol, the alcohol having from 1 to 18 carbon atoms; (b) about from 10 to 70% by weight of tackifier; and (c) about from 0 to 20% by weight of plasticizer.
Claim 2
Dependent Claim
180 words
An acrylic hot melt pressure sensitive adhesive composition comprising (a) 30 to 90% by weight of a thermoplastic comb copolymer of (i) 2-35% by weight, based on the thermoplastic copolymer, of a macromonomer of the general formula X-(Y)n-Z wherein X is a reactive end group capable of copolymerization under free radical conditions with acrylic comonomers to afford the comb copolymer having pendant macromonomer side chains along an acrylic backbone; Y is a linking group in which n is zero or one; and Z is a poly(methacrylate) based a polymeric moiety having a T g greater than 20° C. and a weight average molecular weight of about from 2,000 to 35,000 and being substantially unreactive under copolymerization conditions; and (ii) 65 to 98% by weight, based on the thermoplastic copolymer, of one or more monomers selected from the group consisting of monomeric acrylic or methacrylic acid ester of a non-tertiary alcohol, the alcohol having from 1 to 18 carbon atoms; (b) about from 10 to 70% by weight of tackifier; and (c) about from 0 to 20% by weight of plasticizer.
Claim 3
Dependent Claim
39 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein component (a) (ii) further comprises up to about 10% of at least one monomer selected from methacrylic acid, acrylic acid, acrylamide, methacrylamide, glycidyl methacrylate and hydroxyethyl acrylate.
Claim 4
Dependent Claim
26 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the molecular weight of the micromonomer (a) (i) is about from 4,000 to 20,000.
Claim 5
Dependent Claim
20 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the macromonomer consists essentially of poly methyl methacrylate.
Claim 6
Dependent Claim
34 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the comb copolymer comprises about from 5 to 25% macromonomer and about from 95 to 75% acrylic or methacrylic acid ester comonomer.
Claim 7
Dependent Claim
25 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein component (a) (ii) comprises at least one of 2-ethylhexyl acrylate and isooctyl acrylate.
Claim 8
Dependent Claim
36 words
An acrylic hot melt pressure sensitive adhesive composition of claim 6 wherein component (a) (ii) further comprises about from 1 to 40% of at least one monomer selected from lauryl methacrylate, stearyl methacrylate, and isodecyl acrylate.
Claim 9
Dependent Claim
27 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the comb polymer has an apparent peak molecular weight of about from 70,000 to 600,000.
Claim 10
Dependent Claim
27 words
An acrylic hot melt pressure sensitive adhesive composition of claim 8 wherein the comb polymer has an apparent peak molecular weight of about from 100,000 to 300,000.
Claim 11
Dependent Claim
30 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the concentration of tackifier is about from 30 to 50% by weight, based on the total adhesive composition.
Claim 12
Dependent Claim
24 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the tackifier is selected from hydrogenated rosin esters and hydrogenated poly(aromatic) copolymers.
Claim 13
Dependent Claim
23 words
An acrylic hot melt pressure sensitive adhesive composition of claim 11 wherein the tackifier consists essentially of hydrogenated rosin ester formed with pentaerythritol.
Claim 14
Dependent Claim
23 words
An acrylic hot melt pressure sensitive adhesive composition of claim 11 wherein the tackifier consists essentially of hydrogenated rosin ester formed with glycerine.
Claim 15
Dependent Claim
36 words
An acrylic hot melt pressure sensitive adhesive composition of claim 1 wherein the plasticizer is selected from adipate and glutarate esters, hydrogenated rosin esters, reduced alcohol derivatives, hydrogenated poly (aromatic) copolymers, mineral oils and paraffin oils.
Claim 16
Dependent Claim
25 words
Pressure sensitive adhesive coated sheet material comprising a flexible backing having a coating of an acrylic hot melt pressure sensitive adhesive composition of claim 1.
Claim 17
Dependent Claim
55 words
An adhesive composition of claim 1 wherein the thermoplastic comb copolymer (a) in the absence of said tackifier and plasticizer has a shear adhesion in minutes to failure of less than 50 and said adhesive composition with tackifier (b) and any plasticizer (c) has a shear adhesion in minutes to failure of greater than 150.
Claim 18
Dependent Claim
18 words
An adhesive composition of claim 16 having a shear adhesion in minutes to failure of greater than 50.
Claim 19
Dependent Claim
33 words
An adhesive composition of claim 16 wherein the comb copolymer (a) without tackifier and plasticizer has a shear adhesion of less than 10 and with tackifier and any plasticizer of greater than 150.
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) | 1996-07-05 | 1997-01-04 | 1997-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-05 | 2001-01-04 | 2001-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-05 | 2005-01-04 | 2005-07-06 | $7700.00 | Window Closed / Lapsed |