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US5045569A Expired / Lapsed US ⏱️ 0.0 years remaining

Hollow acrylate polymer microspheres

Assignee: Sandoz AG
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Filing: 1988-11-30
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Granted: 1991-09-03
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Expires: 2008-11-30
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Abstract

Abstract Hollow, polymeric, acrylate, infusible, inherently tacky, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer. Preferred microspheres are those wherein a majority of the hollow microspheres contain at least one of interior void having a diamter of at least 10% of the diameter of the microsphere. These hollow microspheres are useful as repositionable pressure-sensitive adhesives. The invention also provides pressure-sensitive adhesives consisting essentially of such hollow microspheres. Aqueous suspensions of these microspheres, processes for their preparation, spray repositionable pressure-sensitive adhesive compositions, and microsphere-coated sheet materials are also provided. Surprisingly, hollow microspheres of the invention show reduced or even eliminated adhesive transfer, in comparison with prior art repositionable pressure-sensitive adhesives which are based on solid microspheres.

Inventors

  • 👤 Joaquin Delgado

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 08:06
CPC Classifications
C; C09; C09J; C09J133/00; C09J133/04; C09J133/06; C08; C08F; C08F2/00; C08F2/12; C08F2/16; C08F2/22; C08F2/24; C08J; C08J3/00; C08J3/12; C08J3/16; C09J133/08; C08L; C08L2205/00; C08L2205/14; C08L2205/18; C08L2205/20; C09J2301/00; C09J2301/30; C09J2301/302; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 20 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres having a diameter of at least 1 micrometer.
Claim 2
Dependent Claim 20 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres having a diameter of at least 1 micrometer.
Claim 3
Dependent Claim 42 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres according to claim 1 wherein a majority of said microspheres contain at least one interior void having a diameter at least about 10% of the diameter of said hollow microspheres.
Claim 4
Dependent Claim 42 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres according to claim 1 wherein a majority of said microspheres contain at least one interior void having a diameter of at least about 20% of the diameter of said microspheres.
Claim 5
Dependent Claim 42 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric pressure-sensitive adhesive microspheres according to claim 1 wherein a majority of said microspheres contain at least one interior void having a diameter of at least about 30% of the diameter of said microspheres.
Claim 6
Dependent Claim 30 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, pressure-sensitive microspheres according to claim 1 comprising an acrylate polymer having a glass transition temperature of no greater than about -20° C.
Claim 7
Dependent Claim 49 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, pressure-sensitive microspheres according to claim 1 comprising: a) at least about 85 parts by weight of at least one alkyl acrylate or alkyl methacrylate ester, and b) correspondingly, up to about 15 parts by weight of at least one polar monomer.
Claim 8
Dependent Claim 31 words
The hollow microspheres of claim 6 wherein the alkyl acrylate is selected from the group consisting of isooctyl acrylate, 2-ethyl hexyl acrylate, isononyl acrylate, isoamyl acrylate, isodecyl acrylate and butyl acrylate.
Claim 9
Dependent Claim 32 words
The hollow microspheres of claim 6 wherein the polar monomer is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and salts thereof.
Claim 10
Dependent Claim 13 words
A particulate pressure-sensitive adhesive consisting essentially of the hollow microspheres of claim 1.
Claim 11
Dependent Claim 13 words
A particulate pressure-sensitive adhesive consisting essentially of the hollow microspheres of claim 6.
Claim 12
Dependent Claim 17 words
A repositionable spray pressure-sensitive adhesive comprising the hollow microspheres of claim 1 and a liquid medium therefor.
Claim 13
Dependent Claim 23 words
A repositionable spray pressure-sensitive adhesive according to claim 11 further comprising a propellant selected from the group consisting of alkanes, alkenes, and chlorofluorocarbons.
Claim 14
Dependent Claim 17 words
A sheet material having coated on at least a portion thereof the pressure-sensitive adhesive of claim 9.
Claim 15
Dependent Claim 10 words
An aqueous suspension comprising the hollow microspheres of claim 1.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-02 1995-03-04 1995-09-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-02 1999-03-04 1999-09-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-02 2003-03-04 2003-09-03 $7700.00 Window Closed / Lapsed

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