Additives for special effect appearances in plastic parts

• US 6,752,941 B2
• Filed: 03/14/2003
• Issued: 06/22/2004
• Est. Priority Date: 03/14/2002
• Status: Expired due to Term

• Current Assignee: Certainteed, LLC (Compagnie de Saint-Gobain SA)
• Original Assignee: CertainTeed Corp. (Compagnie De Saint-Gobain)
• Inventors: Hills, Richard Arnold
• Primary Examiner(s): Lechert, Jr., Stephen J.
• Application Number:
  US10/389,400
• Publication Number:
  US 20030218266A1
• Time in Patent Office: 466 Days
• Field of Search: 264/75, 264/122, 264/123, 156/244.11
• US Class Current: 264/75
• CPC Class Codes: B29C 48/0014 producing flat articles having components brought in contact outside the extrusion die
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/154 Coating solid articles, i.e. non-hollow articles
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/304 specially adapted for bringing together components, e.g. melts within the die
• CPC Class Codes: B29C 48/35 with rollers
• CPC Class Codes: B29K 2001/00 Use of cellulose, modified cellulose or cellulose derivatives, e.g. viscose, as moulding material
• CPC Class Codes: B29K 2029/04 PVOH, i.e. polyvinyl alcohol B29K2031/04 takes precedence
• CPC Class Codes: B29K 2033/12 Polymers of methacrylic acid esters, e.g. PMMA, i.e. polymethylmethacrylate
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2069/00 Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2081/06 PSU, i.e. polysulfones; PES, i.e. polyethersulfones or derivatives thereof
• CPC Class Codes: B29K 2705/02 Aluminium
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B29L 2011/00 Optical elements, e.g. lenses, prisms
• CPC Class Codes: B44C 5/043 containing wooden elements
• CPC Class Codes: B44F 9/02 wood grain effects

Abstract

The present invention relates to a method of producing a plank product and related components having a controllable and realistic wood-grain appearance, the planks and related components having at least one accent color, the method including the steps of: a) introducing into an extruder a powdered or pelletized base material and accent color pellets, the base material containing less than about 75% by weight wood flour, and having a vicat softening temperature, the accent color pellets (i) having a higher vicat softening temperature than said base material, and (ii) including a styrene polymer having a high vicat softening temperature and a melt flow index of greater than or equal to 1.0 gram per 10 minutes, and at least one additional resin having a substantially lower vicat softening temperature than the styrene polymer; and b) extruding said base material and the accent color pellets through an extrusion die to form a plank under processing temperatures whereby the accent color pellets cause delayed introduction and controlled dispersion of the accent color into the plank material.

Claims

1. A method of producing a plank product having a controllable and realistic wood-grain appearance, the plank product with at least one accent color, the method comprising the steps of:

a) introducing into an extruder a powdered or pelletized base material and accent color pellets, said base material containing less than about 75% by weight wood flour, and having a vicat softening temperature, said accent color pellets (i) having a higher vicat softening temperature than said base material, and (ii) comprising a styrene polymer having a high vicat softening temperature and a melt flow index of greater than or equal to 1.0 gram per 10 minutes, and at least one additional resin having a substantially lower vicat softening temperature than the styrene polymer; and

b) extruding said base material and said accent color pellets through an extrusion die to form a plank under processing temperatures whereby the accent color pellets cause delayed introduction and controlled dispersion of the accent color into the plank material.

2. The method of claim 1, wherein the step of introducing said accent color pellets includes controlling the dispersion of said accent color according to the relative quantities of poly-.alpha.-methylstyrene and said lower vicat softening temperature resin.

3. The method of claim 2, wherein said pellets are introduced into said extruder in an amount of about 1% to about 25% by weight of total material introduced into said extruder.

4. The method of claim 1, wherein said pellets have a vicat softening temperature that is about 15°

C. to about 50°

C. higher than the vicat softening temperature of the base material.

5. The method of claim 4, wherein said pellets have a vicat softening temperature that is about 20°

C. to about 40°

C. higher than the vicat softening temperature of the base material.

6. The method of claim 1, wherein said pellets have a vicat softening temperature of about 100°

C. and about 160°

C.

7. The method of claim 6, wherein said pellets have a vicat softening temperature of about 110°

C. to about 150°

C.

8. The method of claim 7, wherein said pellets have a vicat softening temperature of about 120°

C. to about 140°

C.

9. The method of claim 1, wherein the additional resin is an acrylic.

10. The method of claim 1, wherein the base material is selected from the group consisting of polyvinyl chloride, polypropylene, polyethylene, and polystyrene, and mixtures thereof.

11. The method of claim 1, further comprising the step of introducing into said extrusion die a substrate producing material, and co-extruding said substrate producing material with said base material and said accent color producing material to produce a plastic article.

12. A method of producing a plank product having a controllable and realistic wood-grain appearance, the plank product with at least one accent color, the method comprising the steps of:

a) introducing into an extruder a surface layer base material and accent color pellets, said base material containing less than about 75% by weight wood flour, and having a vicat softening temperature, said accent color pellets having a vicat softening temperature that is higher than the vicat softening temperature of said base material, said accent color pellets comprising (i) about 5% to about 50% by weight poly-.alpha.-methylstyrene, (ii) about 10% to about 60% by weight of at least one additional resin having a substantially lower vicat softening temperature than the poly-.alpha.-methylstyrene, and (iii) about 10% to about 65% by weight of a color pigment; and

b) extruding said base material and said accent color pellets through an extrusion die to form a plank under processing temperatures whereby the accent color pellets cause delayed introduction and controlled dispersion of the accent color into the capstock base material.

13. The method of claim 12, wherein the poly-.alpha.-methylstyrene has a vicat softening temperature greater than about 170°

C.

14. The method of claim 12, wherein the pellets comprise about 12% to about 27% by weight poly-.alpha.-methylstyrene and about 35% to about 45% by weight of the additional resin.

15. The method of claim 12, wherein the pellet comprises about 16% to about 25% by weight poly-.alpha.-methylstyrene and about 28% to about 44% of the additional resin.

16. The method of claim 12, wherein the color pigment is titanium dioxide.

17. The method of claim 12, wherein the additional resin is an acrylic.

18. The method of claim 12, wherein the poly-.alpha.-methylstyrene has a vicat softening temperature greater than about 151°

C.

19. The method of claim 12, where the capstock base material comprises polyvinyl chloride.

20. The method of claim 12, further comprising the step of introducing into said extrusion die a substrate producing material, and co-extruding said substrate producing material with said surface layer base material and said accent color producing material to produce a plastic article.