Rubber latex and method for preparing the same

• US 20070060710A1
• Filed: 10/29/2004
• Published: 03/15/2007
• Est. Priority Date: 10/29/2003
• Status: Abandoned Application

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Lee, Chan-hong, Kim, Geon-soo, Jeong, Ok-yeol, Kim, Young-sim
• Application Number:
  US10/570,714
• Publication Number:
  US 20070060710A1
• Time in Patent Office: Days
• US Class Current: 525/242
• CPC Class Codes: C08C 1/065 Increasing the size of dispersed rubber particles
• CPC Class Codes: C08F 257/02 on to polymers of styrene or alkyl-substituted styrenes
• CPC Class Codes: C08F 265/04 on to polymers of esters
• CPC Class Codes: C08F 265/06 Polymerisation of acrylate or methacrylate esters on to polymers thereof
• CPC Class Codes: C08F 279/02 on to polymers of conjugated dienes
• CPC Class Codes: C08F 283/12 on to polysiloxanes
• CPC Class Codes: C08F 285/00 Macromolecular compounds obtained by polymerising monomers on to preformed graft polymers
• CPC Class Codes: C08F 297/02 using a catalyst of the anionic type
• CPC Class Codes: C08F 6/18 Increasing the size of the dispersed particles
• CPC Class Codes: C08F 6/22 Coagulation
• CPC Class Codes: C08L 23/02 not modified by chemical after-treatment
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 2666/04 Macromolecular compounds according to groups C08L7/00 - C08L49/00, or C08L55/00 - C08L57/00; Derivatives thereof
• CPC Class Codes: C08L 2666/14 Macromolecular compounds according to C08L59/00 - C08L87/00; Derivatives thereof
• CPC Class Codes: C08L 2666/18 Polyesters or polycarbonates according to C08L67/00 - C08L69/00; Derivatives thereof
• CPC Class Codes: C08L 2666/24 Graft or block copolymers according to groups C08L51/00, C08L53/00 or C08L55/02; Derivatives thereof
• CPC Class Codes: C08L 51/00 Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds for ABS polymers C08L55/02; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 51/003 grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds C08L51/04, C08L51/06 take precedence
• CPC Class Codes: C08L 51/04 grafted on to rubbers
• CPC Class Codes: C08L 51/085 on to polysiloxanes
• CPC Class Codes: C08L 55/02 : ABS [Acrylonitrile-Butadiene-Styrene] polymers
• CPC Class Codes: C08L 67/02 : Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 69/00 : Compositions of polycarbonates; Compositions of derivatives of polycarbonates

Abstract

Provided are a rubber latex used as a substrate for an impact modifier, a preparation method thereof, and an impact modifier prepared using the rubber latex. The rubber latex includes a rubber monomer as a main component and has a decreasing gel content from a core to a shell(s). The preparation method includes polymerizing a core followed by polymerization of a shell(s) has a lower gel content that the core. The impact modifier is prepared by common graft polymerization using the rubber latex as a substrate. The rubber latex has a high gel content core and a low gel content shell (s), and thus, is free from problems involved in low or high gel content rubber particles. The rubber latex can be used as a substrate for a high efficiency impact modifier with high rubber content and enhanced impact strength and processability.

Claims

1. A rubber latex comprising a rubber monomer as a main component,

wherein the rubber latex is composed of a core and one or more shell(s), and has a decreasing gel content from the core to the shell(s) and a gel content of 85 to 95%. and a gel content of the core is 90 to 100%.

3. The rubber latex of claim 1, wherein an average gel content of the shell(s) is 70 to 90%.

4. The rubber latex of claim 1, wherein an average particle size of the rubber latex is 800 to 5,000 Å

.

5. The rubber latex of claim 1, wherein the rubber monomer is one or more selected from the group consisting of 1,3-butadiene, isoprene, chloroprene, piperylene, arid a comonomer thereof alkyl acrylate;

and silicon-based monomer.

2. (canceled)

6. A method for preparing a rubber latex having a gel content of 85 to 95% and comprising a rubber monomer as a main component, the method comprising:

polymerizing a core; and

polymerizing one or more shell(s) onto the core so that the shell(s) have a lower gel content than the core.

7. The method of claim 6, wherein in the shell polymerization, one up to five shell(s) are formed so that the rubber latex has a decreasing gel content from the core to the shell(s).

8. The method of claim 6, further comprising particle size enlargement of the rubber latex after the shell polymerization.

9. An impact modifier prepared by graft polymerization using as a substrate a rubber latex prepared by the method of claim 6.

10. The impact modifier of claim 9, wherein the impact modifier is used for a thermoplastic resin or a thermosetting resin.

11. The impact modifier of claim 10, wherein the thermoplastic resin is one or more selected from the group consisting of acrylonitrile butadiene styrene, styrene acrylonitrile copolymer, methylmethacrylate polymer, polyvinylchloride, polycarbonate, polyester, and polyamide.

12. The impact modifier of claim 10, wherein the thermosetting resin is an epoxy resin.