Large-sized vinyl chloride seed, method of preparing the seed, vinyl chloride resin prepared using the seed, and method of preparing the vinyl chloride resin

Abstract

The present invention relates to a large-sized vinyl chloride seed with an average particle size of 0.65 to 1.5 μm, a vinyl chloride resin with improved low-viscosity properties, and preparation methods thereof. The preparation of the large-sized vinyl chloride seed includes adding a vinyl chloride monomer, an emulsifier, and a polymerization initiator to an aqueous medium; homogenizing the mixed solution using a rotor-stator type homogenizer; and subjecting the resultant monomer droplets to a polymerization reaction.

1 . A method of preparing a large-sized vinyl chloride seed, the method comprising:
 adding a vinyl chloride monomer, an emulsifier, and a polymerization initiator to an aqueous medium;   homogenizing the mixed solution using a homogenizer for a predetermined time to obtain monomer droplets; and   polymerizing the monomer droplets.   
   
   
       2 . The method of  claim 1 , wherein the homogenization of the mixed solution is performed for one to three hours. 
   
   
       3 . The method of  claim 1 , wherein the homogenizer is a rotor-stator type homogenizer. 
   
   
       4 . The method of  claim 1 , wherein the polymerization initiator is selected from the group consisting of peroxy dicarbonates, peroxy esters, and azo initiators. 
   
   
       5 . A large-sized vinyl chloride seed, prepared by the method of  claim 1 , having an average particle size of 0.65 to 1.5 μm. 
   
   
       6 . A vinyl chloride resin prepared by seed emulsion polymerization of the large-sized vinyl chloride seed of  claim 5  and a small-sized vinyl chloride seed having an average particle size of 0.08 to 0.2 μm. 
   
   
       7 . The vinyl chloride resin of  claim 6 , which has an average particle size of 0.8 to 3.0 μm. 
   
   
       8 . The vinyl chloride resin of  claim 6 , wherein the large-sized vinyl chloride seed and the small-sized vinyl chloride seed are used in a weight ratio ranging from 0.5 to 2.5. 
   
   
       9 . A method of preparing a vinyl chloride resin, the method comprising: subjecting the large-sized vinyl chloride seed of  claim 5 , a small-sized vinyl chloride seed having an average particle size of 0.08 to 0.2 μm, a vinyl chloride monomer, an emulsifier, and an oil-soluble initiator to a seed polymerization reaction. 
   
   
       10 . The method of  claim 9 , wherein the large-sized vinyl chloride seed is used in an amount of 1.0 to 10.0 parts by weight based on 100 parts by weight of the vinyl chloride monomer. 
   
   
       11 . The method of  claim 9 , wherein the emulsifier is selected from the group consisting of an anionic emulsifier, a nonionic emulsifier, and a combination thereof. 
   
   
       12 . The method of  claim 11 , wherein the anionic emulsifier is selected from the group consisting of a carboxylic acid, an alkyl sulfonic acid, an alkyl benzene sulfonic acid, a sulfosuccinic acid, an α-olefin sulfonic acid, an alkyl phosphoric acid, and a combination thereof. 
   
   
       13 . The method of  claim 11 , wherein the nonionic emulsifier is selected from the group consisting of polyoxyethylene ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkenyl ether, a polyoxyethylene derivative, a glycerin fatty acid ester, a sorbitan fatty acid ester, a polyoxyethylene fatty acid ester, a silicone-based emulsifier, polyethylene glycol or a derivative thereof, polypropylene glycol or a derivative thereof, and a combination thereof.