Stabilized halogen-containing resin composition

Abstract

A stabilized halogen-containing resin composition containing a halogen-containing resin and a stabilizer component comprising a complex (A) of a metal silicate and a calcium hydroxide compound and at least one member selected from a hydrotalcite (B) and a tin-containing stabilizer (C), which composition has synergism (multiplier effect), overcomes the problems of decreases, due to the high loading of a stabilizer, in the inherent mechanical strength and electrical characteristic of the resin and makes reduction of cost of stabilizers, and a process for producing the complex (A).

1 . A stabilized halogen-containing resin composition containing 100 parts by weight of a halogen-containing resin and 0.01 to 10 parts by weight of a stabilizer component comprising a complex (A) of a metal silicate and a calcium hydroxide compound represented by the formula (1),
   Ca 1-x-y M 2+ Al y (OH) 2    (1)   wherein M 2+  represents at least one bivalent metal selected from the group consisting of Mg, Zn, Cu and etc., x is in the range of 0≦x≦0.4 and y is in the range of 0≦y<0.1,   
       and at least one member selected from the group consisting of a hydrotalcite (B) and a tin-containing stabilizer (C). 
     
     
         2 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the metal silicate is represented by the formula (2),
   (Al 2 O 3 ) a (M 2+ O) b SiO 2 .(H 2 O) m    (2)   wherein M 2+  is at least one member selected from the group consisting of Zn, Mg and Ca, a is in the range of 0≦a≦0.5, b is in the range of 0≦b<1, provided that a+b is in the range of 0<a+b<1, and m is in the range of 0≦m<2.   
     
     
         3 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the metal silicate is at least one member selected from the group consisting of activated white clay and acid white clay. 
     
     
         4 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the calcium hydroxide compound is represented by the formula (3),
   Ca 1-x M 2+   x (OH) 2    (3)   wherein M 2+  and x are as defined in the formula (1).   
     
     
         5 . The stabilized halogen-containing resin composition according to  claim 4 , wherein, in the formula (3), M 2+  is at least one member selected from the group consisting of Mg and Zn and x is in the range of 0≦x≦0.2. 
     
     
         6 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the metal silicate is complexed in an amount of 0.5 to 50% by weight based on the calcium hydroxide compound in the complex (A). 
     
     
         7 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the stabilized halogen-containing resin composition is used for a highly heat-resistant electric cable and the weight ratio of the complex (A):the hydrotalcite (B) is 40:60-75:25. 
     
     
         8 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the weight ratio of the complex (A):the tin-containing stabilizer (C) is 15:85-40:60. 
     
     
         9 . The stabilized halogen-containing resin composition according to  claim 1 , wherein the complex (A) is surface-treated with at least one member selected from the group consisting of a higher fatty acid, an alkali metal salt of a higher fatty acid, a phosphoric acid ester, a silane coupling agent, an aluminum coupling agent and a titanium coupling agent in an amount of 0.1 to 10% by weight based on the complex (A). 
     
     
         10 . A process for the production of the complex (A) recited in  claim 1 , comprising hydrating calcium oxide in an aqueous medium containing a metal silicate dispersed therein, then adding an aqueous solution comprising a water-soluble salt of at least one bivalent metal selected from the group consisting of Mg, Zn and etc., to allow the resultant mixture to react, and then carrying out surface-treatment.