Artificial marble containing transparent chip using co-extrusion and process for preparing the same

• US 7,638,189 B2
• Filed: 03/15/2006
• Issued: 12/29/2009
• Est. Priority Date: 08/24/2005
• Status: Expired due to Fees

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Choi, Sang-Hun
• Primary Examiner(s): Shosho; Callie E
• Assistant Examiner(s): Freeman; John
• Application Number:
  US11/376,054
• Publication Number:
  US 20070049658A1
• Time in Patent Office: 1,385 Days
• Field of Search: 523/171, 428/407, 428/403, 428/689, 428/402, 428/218, 428/364, 428/357, 428/212, 428/323, 428/319.3, 428/206, 264/176.1, 524/437, 359/580
• US Class Current: 428/327
• CPC Class Codes: B29B 9/12 characterised by structure or composition
• CPC Class Codes: B29C 48/04 Particle-shaped making granules B29B9/00
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/175 comprising a multi-coloured single component, e.g. striated, marbled or wood-like patterned
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: C04B 16/04 Macromolecular compounds C04B16/02 takes precedence
• CPC Class Codes: C04B 20/0008 Materials specified by a shape not covered by C04B20/0016 - C04B20/0056, e.g. nanotubes
• CPC Class Codes: C04B 20/1033 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: C04B 20/1062 Metals
• CPC Class Codes: C04B 20/1066 Oxides, Hydroxides
• CPC Class Codes: C04B 2103/54 Pigments; Dyes
• CPC Class Codes: C04B 2111/00129 Extrudable mixtures
• CPC Class Codes: C04B 2111/545 Artificial marble
• CPC Class Codes: C04B 2111/805 Transparent material
• CPC Class Codes: C04B 2201/20 for the density
• CPC Class Codes: C04B 26/06 Acrylates
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 428/254 Polymeric or resinous material
• CPC Class Codes: Y10T 428/2998 including synthetic resin or polymer
• CPC Class Codes: Y10T 428/31786 : Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31938 : Polymer of monoethylenically unsaturated hydrocarbon

Abstract

There are disclosed an artificial marble containing pellet-shaped transparent chips, obtained by coating the outer surface of an internal transparent resin layer with a resin layer containing a filler having a high specific gravity using co-extrusion, and a process for preparing the same. The artificial marble using the transparent chips as coloring chips, thus not causing the occurrence of layer separation of the transparent chips, which conventionally occurred in an artificial marble using transparent chips made of a single component, being distinguished from a conventional artificial marble made of combination of the single-colored chips, and expressing a pattern similar to a natural granite.

Claims

1. An artificial marble containing transparent chips, each comprising an internal transparent layer, and an external layer having a specific gravity higher than that of the internal transparent layer and formed on the outer surface of the internal transparent layer,

wherein the whole specific gravity of the transparent chips is 1.3 to 2.0, and the size of the transparent chips is 3 to 20 mm.

2. The artificial marble as set forth in claim 1, wherein the whole specific gravity of the transparent chips is the same as that of a raw material composite for the artificial marble to which the transparent chips are applied or differs from that of the raw material composite for the artificial marble by ±

0.2 or less.

3. The artificial marble as set forth in claim 1, wherein the specific gravity of the external layer is 1.5 to 10.

4. The artificial marble as set forth in claim 1, wherein the light transmittance of the internal transparent layer is 90 to 100%.

5. The artificial marble as set forth in claim 1, wherein a base resin used in the internal transparent layer and the external layer is one or more selected from the group consisting of acrylic resin, polyester resin, and polyethylene terephthalate (PET).

6. The artificial marble as set forth in claim 1, wherein the transparent chips are transparent acrylic chips using acrylic resin as a base resin.

7. The artificial marble as set forth in claim 1, wherein the external layer contains at least one filler selected from the group consisting of titanium dioxide, barium sulfate, aluminum hydroxide, calcium carbonate, silica, metal powders, and metal salts.

8. The artificial marble as set forth in claim 7, wherein the specific gravity of the filler is 2.5 to 10.

9. The artificial marble as set forth in claim 1, wherein the internal transparent layer contains a pearl pigment.

10. The artificial marble as set forth in claim 1, wherein the transparent chips have cylindrical or polyhedral shapes.

11. The artificial marble as set forth in claim 1, wherein the external layer is formed in whole or in part on the outer surface of the internal transparent layer.

12. The artificial marble as set forth in claim 1, wherein the amount of the transparent chips is 1 to 50% by weight of the artificial marble.

13. A process for preparing an artificial marble comprising:

manufacturing transparent chips by forming an external layer having a specific gravity higher than that of an internal transparent layer on the outer surface of the internal transparent layer to obtain a product, and cutting and crushing the obtained product; and

adding the transparent chips to a raw material composite for the artificial marble, wherein the whole specific gravity of the transparent chips is 1.3 to 2.0, and the size of the transparent chips is 3 to 20 mm.

14. The process as set forth in claim 13, wherein the specific gravity of the transparent chips is controlled to be equal to that of the raw material composite of the artificial marble or to differ from that of the raw material composite for the artificial marble by ±

0.2 or less by adjusting the specific gravity and the amount of a filler added to the external layer.

15. The process as set forth in claim 13, wherein a resin composite for the internal transparent layer and a resin composite for the external layer are supplied to an extruder and are co-extruded in the extruder so that the external layer is coated on the outer surface of the internal transparent layer.