Polydiorganosiloxane compositions and methods for use thereof in forming wood plastic composites

Patent metadata

Field	Value
Publication number	US-11820898-B2
Application number	US-202218052711-A
Country	US
Kind code	B2
Filing date	Nov 4, 2022
Priority date	Aug 7, 2019
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

A polydiorganosiloxane is useful in a composition and a method for preparing a wood plastic composite article. The wood plastic composite article is useful as a building material. The polydiorganosiloxane may be added to the composition in liquid form or may form part of a solid carrier component used to make the wood plastic composite article.

First claim

The invention claimed is:

1. A composition for preparing a wood plastic composite article, said composition comprising:
45 weight % to 65 weight % of (a) a lignocellulosic-based filler;
35 weight % to 55 weight % of (b) an ethylene-based polymer;
0.5 weight % to 6 weight % of (c) a polydiorganosiloxane of formula

where each R is an independently selected monovalent hydrocarbon group of 1 to 18 carbon atoms that is free of aliphatic unsaturation, and subscript x has a value sufficient to give the polydiorganosiloxane a viscosity of >350 mPa·s to 100,000 mPa·s measured at 25 ° C. at 0.1 RPM to 50 RPM on a Brookfield DY-III cone & plate viscometer with #CP-52 spindle;
0 to 4 weight % of (d) a maleated ethylene-based polymer; and
>0 to 30 weight % of (e) a mineral filler;
each based on combined weights of starting materials (a), (b), (c), and (d) in said composition.

2. The composition of claim 1 , where the composition comprises 0.5 weight % to 3 weight % of (c) the polydiorganosiloxane.

3. The composition of claim 1 , where (c) the polydiorganosiloxane has viscosity of 1,000 mPa·s to 50,000 mPa·s.

4. The composition of claim 1 , where (c) the polydiorganosiloxane has viscosity of 1,000 mPa·s to 20,000 mPa·s.

5. The composition of claim 1 , where (c) the polydiorganosiloxane has viscosity of 5,000 mPa·s to 12,500 mPa·s.

6. The composition of claim 1 , where (c) the polydiorganosiloxane is a trialkylsiloxy-terminated polydialkylsiloxane.

7. The composition of claim 1 , where in (c) the polydiorganosiloxane, each R is methyl.

8. The composition of claim where the mineral filler is selected from the group consisting of calcium carbonate, talc, and combinations thereof.

9. A method for preparing a wood plastic composite article, said method comprising:
(1) combining starting materials comprising
45 weight % to 65 weight % of (a) a lignocellulosic-based filler;
35 weight % to 55 weight % of (b) an ethylene-based polymer;
0.5 weight % to 6 weight % of (c) a polydiorganosiloxane of formula

where each R is an independently selected monovalent hydrocarbon group of 1 to 18 carbon atoms that is free of aliphatic unsaturation, and subscript x has a value sufficient to give the polydiorganosiloxane a viscosity of >350 mPa·s to <100,000 mPa·s measured at 25° C. at 0.1 RPM to 50 RPM on a Brookfield DY-III cone & plate viscometer with #CP-52 spindle; and
0 to 4 weight % of (d) a maleated ethylene-based polymer;
>0 to 30 weight % of (e) a mineral filler;
each based on combined weights of starting materials (a), (b), (c), and (d);
thereby preparing a composition; and

(2) forming the wood plastic composite article from the composition.

10. The method of claim 9 , where (c) the polydiorganosiloxane has viscosity of 1,000 mPa·s to 50,000 mPa·s.

11. The method of claim 9 , where (c) the polydiorganosiloxane has viscosity of 1,000 mPa·s to 20,000 mPa·s.

12. The method of claim 9 , where (c) the polydiorganosiloxane has viscosity of 5,000 mPa·s to 12,500 mPa·s.

13. The method of claim 9 , where (c) the polydiorganosiloxane is a trialkylsiloxy-terminated polydialkylsiloxane.

14. The method of claim 9 , where in (c) the polydiorganosiloxane, each R is methyl.

15. The method of claim 9 , wherein: (i) preparing the wood plastic composite article from the composition further comprises forming the composition into a desired shape; (ii) preparing the wood plastic composite article from the composition comprises extruding the composition; (iii) preparing the wood plastic composite article from the composition comprises molding the composition; or (iv) any combinations of (i) to (iii).

16. The method of claim 9 , where the wood plastic composite article is useful as a building material selected from the group consisting of decking, railing, fencing, siding, trim, skirts, and window framing.

17. The method of claim 16 , where the building material is decking.

18. The method of claim 17 , where the method further comprises: 3) adding a cap stock layer after step 2).

19. The composition of claim 1 , where (c) the polydiorganosiloxane has viscosity of 5,000 mPa·s to 50,000 mPa·s.

20. The composition of claim 1 , where (c) the polydiorganosiloxane has viscosity of 2,000 mPa·s to 60,000 mPa·s.

Assignees

• Dow Silicones Corp

Inventors

• Mecca Jodi
• Keenihan James
• Courtemanche Marc-Andre
• Bruce Keith
• Chorvath Igor
• Gaal Sean

Classifications

• C08L97/02 Primary

  Lignocellulosic material, e.g. wood, straw or bagasse {(manufacture of articles made from lignocellulosic material by dry processes B27N)} · CPC title

• C08L23/0869

  with unsaturated acids, e.g. [meth]acrylic acid; with unsaturated esters, e.g. [meth]acrylic acid esters · CPC title

• C08L2205/03

  containing three or more polymers in a blend · CPC title

• C08L23/04 Primary

  Homopolymers or copolymers of ethene · CPC title

• C08L23/06 Primary

  Polyethylene · CPC title