Processibility and lacing resistance when silanized pigments are incorporated in polymers

• US 5,607,994 A
• Filed: 02/28/1994
• Issued: 03/04/1997
• Est. Priority Date: 02/28/1994
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Tooley, Patricia A., Musiano, Joseph A., Holtzen, Dwight A.
• Primary Examiner(s): Mulcahy, Peter D.
• Application Number:
  US08/203,108
• Time in Patent Office: 1,100 Days
• Field of Search: 524/265, 524/267, 524/269, 523/212
• US Class Current: 524/265
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2004/64 Nanometer sized, i.e. from 1-100 nanometer
• CPC Class Codes: C01P 2004/80 Particles consisting of a mixture of two or more inorganic phases
• CPC Class Codes: C01P 2006/10 Solid density
• CPC Class Codes: C01P 2006/22 Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability
• CPC Class Codes: C08K 9/06 with silicon-containing compounds
• CPC Class Codes: C09C 1/3684 Treatment with organo-silicon compounds

Abstract

White-pigmented polymers (particularly, polyolefins such as polyethylene) containing white pigments treated with at least one silane or a mixture of at least one silane and at least one polysiloxane are disclosed to improve processibility in compounding and improve performance properties such as lacing resistance in a polymeric matrix.

Claims

1. A polyethylene matrix consisting essentially of polyethylene and about 50 to about 87% by weight silanized TiO₂ pigment, based on the weight of the polyethylene matrix, exhibiting enhanced processibility, wherein the TiO₂ pigment has a coating of about 0.1 to about 5% by weight, based on the weight of the silanized TiO₂, of at least one organosilicon compound having the formula:

space="preserve" listing-type="equation">R.sub.x Si(R'"'"').sub.4-x

wherein

R is a nonhydrolyzable aliphatic, cycloaliphatic or aromatic group having 8-20 carbon atoms;

R'"'"' is a hydrolyzable group selected from alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and

x=1 to 3.

3. The composition of claim 1 or claim 2 wherein R is aliphatic having 8-18 carbons, R'"'"' is alkoxy, and x=1 to 3.

5. The composition of claim 1 or claim

wherein the silanized TiO₂ pigment is present in the amount of about 70 to about 82% by weight and the organosilicon compound is selected from the group consisting of octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, heptadecyltriethoxysilane, octadecyltriethoxysilane, mixtures thereof;

and mixtures of butyltrimethoxysilane and polydimethylsiloxane, and mixtures of octyltriethoxysilane and polydimethylsiloxane.

6. The composition of claim 5 wherein

(a) the silanized TiO₂ is TiO₂ coated with about 0.5 to 1.5% by weight of an octyltriethoxysilane;

and

(b) the silanized TiO₂ pigment is present in the amount of about 70% by weight.

7. The composition of claim 6 wherein the coating comprises about 1% by weight of butyltrimethoxysilane and 1% by weight polydimethylsilane.

8. The composition of claim 1 wherein the composition exhibits resistance to lacing at a TiO₂ concentration ranging from about 0.2 to about 20% by weight based on the weight of the polyethylene matrix.

9. The composition of claim 1 or 2 wherein R is an aliphatic having 8 carbons, R'"'"' is alkoxy, and X=1 to 3.

2. A polyethylene matrix consisting essentially of polyethylene and about 50 to about 87% by weight silanized TiO₂ pigment, based on the weight of the polyethylene matrix, wherein the TiO₂ pigment has a coating of about 0.1 to about 5% by weight, based on the weight of the silanized TiO₂, of an organosilicon compound comprising a mixture of (a) and (b) wherein

(a) is at least one silane having the formula:

space="preserve" listing-type="equation">R.sub.x Si(R'"'"').sub.4-x

wherein

R is a nonhydrolyzable aliphatic, cycloaliphatic or aromatic group having 1-20 carbon atoms;

R'"'"' is a hydrolyzable group selected from alkoxy, halogen, acetoxy or hydroxy or mixtures thereof; and

x=1 to 3; and

(b) is at least one polysiloxane having the formula;

##EQU2## wherein R is an organic or inorganic group;

n=0-3; and

m≧

2.

4. The composition of claim 2 wherein the mixture comprises the silane selected from the group consisting of butyltrimethoxysilane and octyltriethoxysilane, and the siloxane is polydimethylsiloxane.