Sustained-release thermoplastic polymer composition and product comprising the same

Abstract

The polymer composition comprises a polymer and a liquid compound having poor compatibility with the polymer. When the liquid compound is caused to be held in the polymer in a high concentration, a block copolymer having in the molecule a copolymerized polymer block unit having high compatibility with both of the matrix polymer and the liquid compound is incorporated and dispersed. As a result, the block copolymer serves like a surfactant to form an interface and the liquid compound is enclosed inside the interface to thereby form a liquid-in-solid polymer type emulsion.

1 . A composition which constitutes a liquid-in-solid polymer emulsion at room temperature, comprising:
 a thermoplastic polymer (A);   0.1 to 50 parts by weight of a block copolymer (B) mixed with 100 parts by weight of the thermoplastic polymer (A), the block copolymer (B) being phase-separated from the thermoplastic polymer (A); and   0.1 to 20 parts by weight of a liquid compound (C) dispersed in 100 parts by weight of the mixture of the thermoplastic polymer (A) and the block copolymer (B),   wherein the block copolymer (B) contains a block (b1) having high compatibility with the thermoplastic polymer (A) but low compatibility with the liquid compound (C) and a block (b2) having high compatibility with the liquid compound (C) but low compatibility with the thermoplastic polymer (A),   the liquid compound (C) has low compatibility with the block (b1) and the thermoplastic polymer (A) but high compatibility with the block (b2), the liquid compound (C) being phase-separated from the thermoplastic polymer (A) and being liquid at 100° C. or lower,   the liquid compound (C) is enclosed by the block copolymer (B) by a surfactant-like function of the block copolymer (B),   the thermoplastic polymer (A) is a polystyrene polymer,   the block (b1) is a polystyrene block and the block (b2) is a polyolefin block, and   the block copolymer (B) is at least one selected from the group consisting of
 a polystyrene-poly(ethylene/propylene) block copolymer, 
 a polystyrene-poly(ethylene/butylene) block copolymer, 
 a polystyrene-poly(ethylene/propylene)-polystyrene block copolymer, 
 a polystyrene-poly(ethylene/butylene)-polystyrene block copolymer, and 
 a polystyrene-poly(ethylene-ethylene/propylene)-polystyrene block copolymer. 
   
   
   
       2 . The composition of  claim 1 , wherein the liquid compound (C) is an organic compound or organic compound solution. 
   
   
       3 . The composition of  claim 1 , wherein the liquid compound (C) is an organic compound or organic compound solution which has higher compatibility with polyolefin than with polystyrene and which is phase-separated from polystyrene. 
   
   
       4 . A composition, comprising:
 a dispersion medium; and   the composition of  claim 1  constituting a liquid-in-solid polymer emulsion at room temperature which is dispersed in the dispersion medium,   wherein the dispersion medium is any one of
 a polymer other than the thermoplastic polymer (A), 
 a blend of the polymer other than the thermoplastic polymer (A) and a plasticizer, and 
 a solution of the polymer other than the thermoplastic polymer (A). 
   
   
   
       5 . The composition of  claim 4 , wherein the polymer other than the thermoplastic polymer (A) is a thermoplastic polymer and/or a thermosetting polymer or thermosetting polymer precursor. 
   
   
       6 . The composition of  claim 1 , wherein the liquid compound (C) is at least one of a pharmaceutical product, an antibacterial agent, an antifungal agent, an antiviral agent, an antistatic agent, an antialgal agent, a preservative, an aromatic agent, an insect repellent, an insecticide, a rodent repellent, a bird repellent, an animal repellent, an attractant, an agricultural chemical, an antifouling agent, a flame retardant, a dust-capturing agent, a fertilizer and a deodorant. 
   
   
       7 . A molded article formed from the composition of  claim 1 , wherein the molded article has a coating of the liquid compound (C) which has bled out of the composition, the coating having a thickness of 1 μm or less. 
   
   
       8 . The molded article of  claim 7  which is an extrusion-molded article. 
   
   
       9 . The molded article of  claim 7  which is a fiber, a fabric or fiber product made of the fiber, or a laminate of the same. 
   
   
       10 . The molded article of  claim 7  which is a pipe, a sheet, a film, and a laminate of the same. 
   
   
       11 . The molded article of  claim 7  which is an injection-molded article, a rotational-molded article, or a blow-molded article. 
   
   
       12 . A paint or coating material, comprising the composition of  claim 1  or a mixture or dilution of the same. 
   
   
       13 . A filter, comprising the fabric or fiber product or the laminate of  claim 9  as a main dust-capturing material.