US4968562A
Expired / Lapsed
US
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Hollow acid-free acrylate polymeric microspheres having multiple small voids
Assignee: 3M Co
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Filing: 1990-02-27
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Granted: 1990-11-06
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Expires: 2010-02-27
Abstract
Abstract Hollow, polymeric, acrylate, infusible, inherently tacky, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer wherein a majority of the microspheres contain multiple interior voids, a majority of the voids having a diameter of less than about 10% of the diameter of the microspheres, the total of the diameters of the voids being at least about 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 acid-free hollow microspheres. Aqueous suspensions of these microspheres, processes for their preparation, spray repositionable pressure-sensitive adhesive compositions, and pressure-sensitive adhesive coated sheet materials are also provided. Surprisingly, hollow microspheres of the invention may be used in combination with delicate substrates such as photographs without causing discoloration or damage, in comparison with prior art repositionable pressure-sensitive adhesives.
Inventors
- 👤 Joaquin Delgado
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:48
CPC Classifications
C; C09; C09J; C09J133/00; C09J133/04; C09J133/06; C09J133/08; C09J109/00; B; B01; B01J; B01J13/00; B01J13/02; B01J13/06; B01J13/14; C09J7/00; C09J7/30; C09J7/38; C09J7/381; C09J7/385; C08; 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: 17
Claim 1
Independent Claim
75 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer to about 250 micrometers wherein a majority of said microspheres contain multiple interior voids, a majority of said voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the void diameters being at least about 10% of the diameter of said hollow microsphere.
Claim 2
Dependent Claim
75 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer to about 250 micrometers wherein a majority of said microspheres contain multiple interior voids, a majority of said voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the void diameters being at least about 10% of the diameter of said hollow microsphere.
Claim 3
Dependent Claim
71 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer wherein a majority of said microspheres contain multiple interior voids, a majority of said voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the void diameters being at least about 20% of the diameter of said hollow microsphere.
Claim 4
Dependent Claim
71 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer wherein a majority of said microspheres contain multiple interior voids, a majority of said voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the void diameters being at least about 20% of the diameter of said hollow microsphere.
Claim 5
Dependent Claim
71 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer wherein a majority of said microspheres contain multiple interior voids, a majority of said voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the void diameters being at least about 30% of the diameter of said hollow microsphere.
Claim 6
Dependent Claim
71 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres having an average diameter of at least about 1 micrometer wherein a majority of said microspheres contain multiple interior voids, a majority of said voids having a diameter of less than about 10% of the diameter of the microsphere, the total of the void diameters being at least about 30% of the diameter of said hollow microsphere.
Claim 7
Dependent Claim
54 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive microspheres according to claim 1 comprising: (a) at least about 70 parts by weight of at least one alkyl acrylate or alkyl methacrylate ester, and (b) correspondingly, up to about 30 parts by weight of at least one nitrogen-containing polar monomer.
Claim 8
Dependent Claim
54 words
Hollow, polymeric, acrylate, inherently tacky, infusible, solvent-insoluble, solvent-dispersible, elastomeric, nitrogen-containing, acid-free pressure-sensitive adhesive 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 nitrogen-containing polar monomer.
Claim 9
Dependent Claim
31 words
The hollow acid-free microspheres of claim 4 wherein the alkyl acrylate is selected from the group consisting of isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, isoamyl acrylate, isodecyl acrylate and butyl acrylate.
Claim 10
Dependent Claim
31 words
The hollow acid-free microspheres of claim 6 wherein the nitrogen-containing polar monomer is selected from the group consisting of N-vinyl-2-pyrrolidone, N-vinyl caprolactam, 2-vinyl-4,4-dimethyl-2-oxazolin-5-one, dimethylaminoethyl methacrylate, acrylamide, t-butyl acrylamide and N-octyl acrylamide.
Claim 11
Dependent Claim
14 words
A particulate pressure-sensitive adhesive consisting essentially of the hollow acid-free microspheres of claim 1.
Claim 12
Dependent Claim
14 words
A particulate pressure-sensitive adhesive consisting essentially of the hollow acid-free microspheres of claim 4.
Claim 13
Dependent Claim
13 words
A particulate pressure-sensitive adhesive consisting essentially of the hollow microspheres of claim 7.
Claim 14
Dependent Claim
17 words
A repositionable spray pressure-sensitive adhesive comprising the hollow microspheres of claim 1 and a liquid medium therefor.
Claim 15
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 16
Dependent Claim
17 words
A sheet material having coated on at least a portion thereof the pressure-sensitive adhesive of claim 8.
Claim 17
Dependent Claim
10 words
An aqueous suspension comprising the hollow microspheres of claim 1.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |