Redispersible polymer powder

Patent metadata

Field	Value
Publication number	US-9745459-B2
Application number	US-201314652135-A
Country	US
Kind code	B2
Filing date	Dec 11, 2013
Priority date	Dec 14, 2012
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

The present invention relates to a water redispersible polymer powder (RDP) which comprises a co-dried admixture of a water-insoluble film forming polymer, a colloidal stabilizer and rubber particles. The presence of rubber within the RDP does not significantly affect redispersibility and may, when incorporated into hydraulically-binding compositions, provide an improvement in the physical properties of the resultant hydraulically bound composition.

First claim

The invention claimed is:

1. A water redispersible polymer powder (RDP) comprising a co-dried admixture of a water-insoluble film-forming polymer and a colloidal stabilizer, wherein said co-dried admixture further comprises crosslinked or vulcanised rubber particles of ground tire rubber.

2. The water redispersible polymer powder according to claim 1 , wherein said water-insoluble film-forming polymer comprises a styrene-butadiene copolymer or the copolymerization product of styrene, butadiene and one or more other monomer.

3. The water redispersible polymer powder according to claim 1 , wherein said water-insoluble film forming polymer has a glass transition temperature, calculated using the Fox equation, of from −60° C. to 80° C.

4. The water redispersible polymer powder according to claim 1 , wherein the colloidal stabilizer is a polyvinyl alcohol.

5. The water redispersible polymer powder according to claim 1 , wherein said colloidal stabilizer is present in an amount from 1 to 20 weight percent, based on the total dry weight of the RDP.

6. The water redispersible polymer powder according to claim 1 , wherein the weight ratio of said water-insoluble film-forming polymer to said rubber particles is from 99:1 to 1:9.

7. The water redispersible polymer powder according to claim 1 , wherein said rubber particles have a mesh particle size of 1000μm or less.

8. A method for producing a water redispersible polymer powder, said method comprising:
a. providing an aqueous dispersion comprising a water-insoluble film-forming polymer and a colloidal stabilizer; and
b. drying said aqueous dispersion,
wherein said aqueous dispersion further comprises crosslinked or vulcanised rubber particles of ground tire rubber.

Assignees

• Dow Global Technologies Llc

Inventors

• Dombrowski Juergen
• Kuehn Hartmut
• Perello Margarita
• Scharlemann Sonja

Classifications

• C04B2111/00637

  as glue or binder for uniting building or structural materials · CPC title

• C09J125/10

  with conjugated dienes · CPC title

• C04B40/0608

  Dry ready-made mixtures, e.g. mortars at which only water or a water solution has to be added before use · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C08J3/12

  Powdering or granulating · CPC title