Process for producing phenoxyphosphazene compound, flame- retardant resin composition, and flame-retardant resin molding

Abstract

The phenoxyphosphazene compound of the present invention is prepared by treating a phenoxyphosphazene compound with (a) at least one adsorbent selected from activated carbon, silica gel, activated alumina, activated clay, synthetic zeolite and macromolecular adsorbents, (b) at least one reagent selected from metal hydrides, hydrazine, hypochlorites, thiosulfates, dialkyl sulfuric acids, ortho esters, diazoalkanes, lactones, alkanesultones, epoxy compounds and hydrogen peroxide or (c) both the adsorbent and reagent. Incorporation of the phenoxyphosphazene compound prepared by the process of the invention into a synthetic resin achives the following advantages: the synthetic resin can be prevented from discoloration; when the resultant resin composition is stored for a long time, the properties of the synthetic resin, such as heat resistance, weatherability, resistance to discoloration and chemical resistance are not deteriorated; and the resin composition gives a resin composition molded article excellent in properties such as flame retardancy, thermal stability, and moldability.

1 . A process for preparation of an improved phenoxyphosphazene compound by treating a phenoxyphosphazene compound with (a) at least one adsorbent selected from activated carbon, silica gel, activated alumina, activated clay, synthetic zeolite and macromolecular adsorbents, (b) at least one reagent selected from metal hydrides, hydrazine, hypochlorites, thiosulfates, dialkyl sulfuric acids, ortho esters, diazoalkanes, lactones, alkanesultones, epoxy compounds and hydrogen peroxide or (c) both the adsorbent and reagent.  
     
     
         2 . A process for preparation of a phenoxyphosphazene compound according to  claim 1 , wherein the phenoxyphosphazene compound is treated with the adsorbent.  
     
     
         3 . A process for preparation of a phenoxyphosphazene compound according to  claim 1 , wherein the phenoxyphosphazene compound is treated with the reagent.  
     
     
         4 . A process for preparation of a phenoxyphosphazene compound according to  claim 3 , wherein the reagent is at least one member selected from the group consisting of sodium borohydride, sodium thiosulfate, dimethyl sulfuric acid, triethyl ortho acetate, diazomethane and 1,3-propanesultone.  
     
     
         5 . The process for preparation of a phenoxyphosphazene compound according to  claim 1 , wherein the phosphazene compound is at least one compound selected from (1) cyclic phenoxyphosphazene compound represented by formula  
       
         
           
           
               
               
           
         
         wherein m is an integer from 3 to 25 and Ph represents a phenyl group;  
         (2) chain-like phenoxyphosphazene compound represented by formula  
         
           
             
             
                 
                 
             
           
         
         wherein X 1  represents a group —N═P(OPh) 3  or a group —N═P(O)OPh, Y 1  represents a group —P(OPh) 4  or a group —(O)(OPh) 2 , n is an integer from 3 to 10000, and Ph is as defined above; and  
         (3) crosslinked phenoxyphosphazene compound prepared by crosslinking at lease one phosphazene compound selected from the above cyclic phenoxyphosphazene compound and chain-like phenoxyphosphazene compound with at least one crosslinking group selected from o-phenylene group, m-phenylene group, p-phenylene group and a bisphenylene group which is represented by formula  
         
           
             
             
                 
                 
             
           
         
         wherein A represents —C(CH 3 ) 2 —, —SO 2 —, —S— or —O— and a is 0 or 1, the crosslinked phenoxyphosphazene compound having the following characteristics: 
 (a) each of the crosslinking groups is interposed between two oxygen atoms left after the elimination of phenyl groups of the phosphazene compound;  
 (b) the amount of the phenyl groups in the crosslinked compound is 50 to 99.9% based on the total amount of the phenyl groups in the phosphazene compound (1) and/or (2); and  
 (c) the crosslinked phenoxyphosphazene compound has no free hydroxyl groups in the molecule.  
 
       
     
     
         6 . A phenoxyphosphazene compound having an acid value lower than 0.025.  
     
     
         7 . A phenoxyphosphazene compound prepared by any process of  claims 1  to  5 .  
     
     
         8 . A phenoxyphosphazene compound prepared by any process of  claims 1  to  5 , the compound having an acid value lower than 0.025.  
     
     
         9 . A flame retardant comprising the phenoxyphosphazene compound as defined in any of  claims 6  to  8 .  
     
     
         10 . A flame-retardant resin composition comprising the phenoxyphosphazene compound as defined in any of  claims 6  to  8  and a synthetic resin.  
     
     
         11 . The flame-retardant resin composition according to  claim 10 , wherein the synthetic resin is a polycarbonate resin or a mixed resin of polycarbonate resin and at least one of other resins.  
     
     
         12 . The flame-retardant resin composition according to  claim 11 , wherein said other resin is ABS resin.  
     
     
         13 . A molded article of flame-retardant resin prepared by molding the flame-retardant resin composition as defined in any of  claims 10  to  12 .