Cellulosic-reinforced composites having increased resistance to water absorption

• US 7,348,371 B2
• Filed: 12/20/2005
• Issued: 03/25/2008
• Est. Priority Date: 12/20/2005
• Status: Expired due to Fees

• Current Assignee: Equistar Chemicals LP (Lyondellbasell Industries NV)
• Original Assignee: Equistar Chemicals LP (Lyondellbasell Industries NV)
• Inventors: Shankernarayan, Manivakkam J., Mehta, Sameer D.
• Primary Examiner(s): Zimmer; Marc S.
• Application Number:
  US11/312,617
• Publication Number:
  US 20070141337A1
• Time in Patent Office: 826 Days
• Field of Search: None
• US Class Current: 524/13
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: C08L 1/08 Cellulose derivatives
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 2205/03 containing three or more polymers in a blend
• CPC Class Codes: C08L 2205/035 containing four or more polymers in a blend
• CPC Class Codes: C08L 23/06 Polyethene
• CPC Class Codes: C08L 23/0815 Copolymers of ethene with aliphatic 1-olefins
• CPC Class Codes: C08L 23/0892 containing monomers with other atoms than carbon, hydrogen or oxygen atoms
• CPC Class Codes: C08L 23/26 modified by chemical after-treatment
• CPC Class Codes: C08L 2666/06 Homopolymers or copolymers of unsaturated hydrocarbons; Derivatives thereof
• CPC Class Codes: C08L 2666/26 Natural polymers, natural resins or derivatives thereof according to C08L1/00 - C08L5/00, C08L89/00, C08L93/00, C08L97/00 or C08L99/00
• CPC Class Codes: C08L 43/04 Homopolymers or copolymers of monomers containing silicon
• CPC Class Codes: C08L 51/06 grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
• CPC Class Codes: C08L 97/02 Lignocellulosic material, e.g. wood, straw or bagasse manufacture of articles made from lignocellulosic material by dry processes B27N
• CPC Class Codes: Y10T 428/2965 Cellulosic

Abstract

Cellulosic-reinforced composites having increased resistance to water absorption are provided. The improved composites are obtained using a mixture of high density polyethylene and silane copolymer with the cellulosic filler.

Claims

1. A cellulosic-reinforced composite comprising:

(a) 35 to 85 wt. % polyolefin matrix polymer consisting of;

(i) a high density polyethylene resin having a density in the range 0.935 to 0.970 g/cm³ and

(ii) a silane copolymer, the weight ratio of said high density polyethylene to said silane copolymer ranging from 50;

1 to 1;

50; and

(b) 15 to 65 wt. % cellulosic filler.

2. The composite of claim 1 wherein the high density polyethylene is a copolymer of ethylene and butene-1, hexene-1 or octene-1 and has a density from 0.940 to 0.965 g/cm³.

3. The composite of claim 2 wherein the high density polyethylene has a density from 0.945 to 0.960 g/cm³ and melt index from 0.01 to 50 g/10 min.

4. The composite of claim 1 wherein the silane copolymer is an ethylene polymer having silane functionality incorporated in the polymer chain by copolymerization or attached to the polymer chain by grafting.

5. The composite of claim 4 wherein the silane copolymer has from 0.1 to 20 wt. % alkoxysilane of the formula H₂C═

CH—

Si—

(OR)₃ where R is a C_1-4 alkyl group incorporated by copolymerization or grafting.

6. The composite of claim 5 wherein the silane copolymer has a density from 0.865 to 0.965 g/cm³ and melt index from 0.05 to 50 g/10 min.

7. The composite of claim 6 wherein the silane copolymer is a copolymer of ethylene and 0.5 to 7.5 wt. % vinyltrimethoxysilane having a density from 0.915 to 0.960 g/cm³ and melt index from 0.25 to 40 g/10 min.

8. The composite of claim 1 wherein the weight ratio of high density polyethylene to silane copolymer is from 20:

1 to 1;

1.

9. The composite of claim 1 wherein the cellulosic filler is a wood filler and comprises 20 to 60 wt. % of the composite.

10. The composite of claim 9 wherein the wood filler is wood flour.

11. The composite of claim 1 containing 0.01 to 25 wt. % additional additives.

12. The composite of claim 11 which contains 0.01 to 2 wt. % metal carboxylate.

13. The composite of claim 11 which contains 0.1 to 10 wt. % ethylene polymer grafted with 0.1 to 5 wt. % ethylenically unsaturated carboxylic acid or acid derivative.

14. The composite of claim 11 which contains 1 to 20 wt. % mineral filler.

15. A cellulosic-reinforced composite comprising:

(a) 35 to 85 wt. polyolefin matrix polymer consisting of a mixture of

(i) high density copolymer of ethylene and butene-1, hexene-1 or octene-1 having a density from 0.940 to 0.965 g/cm³ and melt index from 0.01 to 50 g/10 min and

(ii) ethylene polymer having 0.1 to 20 wt. % alkoxysilane of the formula H₂C═

CH—

Si—

(OR)₃ where R is a C_1-4 alkyl group incorporated in the polymer chain by copolymerization or attached to the polymer chain by grafting, the weight ratio of (i);

(ii) ranging from 20;

1 to 1;

1; and

(b) 15 to 65 wt. % wood filler.

16. The composite of claim 15 comprising 40 to 80 wt. % (a) and 20 to 60 wt. % wood flour.