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US4456734A Expired / Lapsed US ⏱️ 0.0 years remaining

Rubber powders

Assignee: Bayer AG
•
Filing: 1982-01-04
•
Granted: 1984-06-26
•
Expires: 2002-01-04
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Abstract

Abstract Free-flowing rubber powders of particles having an average diameter of from 0.01 to 10 mm which contain a grafted-on shell of the polymer or copolymer of one or more vinyl monomers in a quantity of from 2 to 20% by weight, based on the rubber, which rubber is a latex polymer of which the latex particles consist essentially of from 99 to 80% by weight of acrylate rubber having glass transition temperatures below 0° C. and from 1 to 20% by weight of polymer having glass transition temperatures above 0° C. grafted thereon, and a process for their production, wherein the latex of the rubber is completely broken to form an aqueous suspension of the rubber, after which from 2 to 20% by weight, based on the rubber, of one or more vinyl monomers which form polymers having glass transition temperatures above 25° C. are introduced into the suspension and the monomer(s) is/are polymerized, optionally after the addition of a radical-forming catalyst.

Inventors

  • 👤 Christian Lindner
  • 👤 Karl-Heinz Ott

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 15:19
CPC Classifications
C; C08; C08F; C08F285/00

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 132 words
A process for the production of a free-flowing rubber powder containing particles having an average diameter of from 0.01 to 10 mm, said process comprising completely breaking a latex of a rubber whose particles consist essentially of 99 to 80%, by weight, of an acrylate rubber having a glass transition temperature of below 0° C. and from 1 to 20%, by weight, of a polymer having a glass transition temperature above 0° C. so as to form an aqueous suspension of said rubber, then introducing into said aqueous suspension from 2 to 20% by weight, based on the rubber, of at least one vinyl monomer which forms a polymer having a glass transition temperature of about 25° C., and then polymerizing said vinyl monomer in the optional presence of a radical-forming catalyst.
Claim 2
Dependent Claim 132 words
A process for the production of a free-flowing rubber powder containing particles having an average diameter of from 0.01 to 10 mm, said process comprising completely breaking a latex of a rubber whose particles consist essentially of 99 to 80%, by weight, of an acrylate rubber having a glass transition temperature of below 0° C. and from 1 to 20%, by weight, of a polymer having a glass transition temperature above 0° C. so as to form an aqueous suspension of said rubber, then introducing into said aqueous suspension from 2 to 20% by weight, based on the rubber, of at least one vinyl monomer which forms a polymer having a glass transition temperature of about 25° C., and then polymerizing said vinyl monomer in the optional presence of a radical-forming catalyst.
Claim 3
Dependent Claim 22 words
The process of claim 1 wherein said rubber is a homo- or co-polymer of at least one alkyl acrylate having rubber properties.
Claim 4
Dependent Claim 41 words
The process of claim 1 wherein said polymer having a glass transition temperature above 0° C. is a polymer of at least one monomer selected from the group consisting of styrene, methyl styrene, acrylonitrile, alkyl acrylate, alkyl methacrylate and vinyl acetate.
Claim 5
Dependent Claim 23 words
The process of claim 1 wherein said vinyl monomer is selected from the group consisting of styrene, acrylonitrile, alkyl methacrylate and mixtures thereof.

References Cited (Backward Citations)

US3833682A Cited
US3787522A Cited
US3959408A Cited
US3985703A Cited
FR2319655A1 Cited
GB1520338A Cited
US4026970A Cited
US4141932A Cited
US4247434A Cited
US4264678A Cited
US4265939A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-06-26 1987-12-26 1988-06-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-06-26 1991-12-26 1992-06-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-06-26 1995-12-26 1996-06-26 $7700.00 Window Closed / Lapsed

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