Rubber polymer, graft copolymer, preparation methods therefor, and impact resistant and heat resistant resin composition

• US 9,951,168 B2
• Filed: 09/30/2014
• Issued: 04/24/2018
• Est. Priority Date: 09/30/2013
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Chai, Joo Byung, Jung, Yu Sung, Park, Eun Seon, Jeon, Tae Young, Kim, Young Min, Lee, Jin Ho
• Primary Examiner(s): Mullis, Jeffrey C
• Application Number:
  US14/893,889
• Publication Number:
  US 20170327618A1
• Time in Patent Office: 1,302 Days
• CPC Class Codes: C08F 236/10 with vinyl-aromatic monomers
• CPC Class Codes: C08F 279/04 Vinyl aromatic monomers and nitriles as the only monomers
• CPC Class Codes: C08L 2201/08 Stabilised against heat, light or radiation or oxydation
• CPC Class Codes: C08L 25/12 with unsaturated nitriles
• CPC Class Codes: C08L 25/16 Homopolymers or copolymers of alkyl-substituted styrenes
• CPC Class Codes: C08L 51/04 grafted on to rubbers
• CPC Class Codes: C08L 9/00 Compositions of homopolymers or copolymers of conjugated diene hydrocarbons

Abstract

Disclosed are a rubber polymer, a graft copolymer, methods of preparing the same, and an impact and heat resistant resin composition. According to the present invention, provided are rubber latex and a graft copolymer which may realize a product having superior impact resistance, heat resistance and chemical resistance by adding a specific crosslinking regulator to the rubber polymer, methods of preparing the same, and an impact and heat resistant resin composition.

Claims

1. A method of preparing a rubber polymer using emulsion polymerization, wherein a prepared crosslinking regulator is comprised in an amount of 5% to 20% by weight based on 100% by weight in a total of monomers constituting the rubber polymer, the method comprising:

inputting 45% to 60% by weight of a diene-based monomer and 5% to 20% by weight of a crosslinking control monomer based on 100% by weight in a total of monomers constituting the rubber polymer, and initiating the emulsion polymerization; and

performing emulsion polymerization of the diene-based monomer until a conversion rate of the polymerization is 40% to 60%;

continuously inputting 20% to 50% by weight of the diene-based monomer until a polymerization conversion rate is 70% to 80%; and

after the 20% to 50% by weight of the diene-based monomer has been input, continuing the emulsion polymerization until a rubber polymer having a gel content of 70% to less than 95% and a swelling index of 15 to less than 25 at a polymerization conversion rate of 90% to 98% is prepared.

2. The method according to claim 1, wherein the diene-based monomer is one or more selected from among 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 2,3-dimethyl-1,3-pentadiene, and 2-phenyl-1,3-butadiene.

3. The method according to claim 1, wherein the crosslinking control monomer comprises at least one styrene-based monomer selected from styrene, α

-methyl styrene, α

-methyl-4-butylstyrene, 4-phenyl styrene, 2,5-dimethyl styrene, 2-methyl styrene, α

-methyl-3,5-di-t-butylstyrene, α

-methyl-3,4,5-trimethylstyrene, α

-methyl-4-benzylstyrene and α

-methyl-4-cyclohexylstyrene.

4. The method according to claim 1, wherein the crosslinking control monomer is one or more acrylic acid ester based monomers selected from methyl methacrylate, methyl acrylate, ethylacrylate, butylacrylate and 2-ethylhexyl acrylate.

5. The method according to claim 1, wherein the crosslinking control monomer comprises one or more vinyl cyanide monomers selected from acrylonitrile, methacrylonitrile and ethacrylonitrile.

6. The method according to claim 1, wherein the crosslinking control monomer comprises one or more unsaturated carboxylic acids selected from acrylic acid, maleic acid, methacrylic acid, itaconic acid and fumaric acid.

7. A method of preparing a graft copolymer from a rubber polymer, wherein, as the rubber polymer, a crosslinking regulator-comprising rubber polymer obtained according to the method of claim 1 is used.

8. The method according to claim 7, wherein 20% to 50% by weight of one or more monomers selected from styrene-based monomer, vinyl cyanide monomer and acrylic acid ester monomer is added to 50% to 80% by weight of the crosslinking regulator-comprising rubber polymer, and graft-copolymerized with rubber particles.