Organopolysiloxane

Abstract

There is provided an organopolysiloxane which is excellent in extensibility as well as solubility and dispersibility in water and lower alcohols. There is provided an organopolysiloxane with a poly(N-acylalkyleneimine) segment having a repeating unit represented by the following general formula (1): wherein R 1 represents a hydrogen atom or an alkyl group, an aralkyl group, or an aryl group each having 1 to 22 carbon atoms, and n is 2 or 3, wherein the segment is bound to each of at least two silicon atoms of an organopolysiloxane segment as a main chain via an alkylene group containing a hetero atom, and wherein the number-average molecular weight of the segment is 800 to 1600, the mass ratio of the organopolysiloxane segment as a main chain and the poly(N-acylalkyleneimine) segment is 65/35 to 82/18, and the weight-average molecular weight of the organopolysiloxane segment as a main chain is 10,000 to 100,000.

1 . An organopolysiloxane comprising a poly(N-acylalkyleneimine) segment having a repeating unit represented by the following general formula (1): 
     
       
         
         
             
             
         
       
     
     wherein R 1  represents a hydrogen atom or an alkyl group, an aralkyl group, or an aryl group each having 1 to 22 carbon atoms, and n is 2 or 3, wherein said segment is bound to each of at least two silicon atoms of an organopolysiloxane segment as a main chain via an alkylene group comprising a hetero atom, and wherein
 the number-average molecular weight of the poly(N-acylalkyleneimine) segment is 800 to 1600, 
 the mass ratio (a/b) of the organopolysiloxane segment (a) as a main chain and the poly(N-acylalkyleneimine) segment (b) is 65/35 to 82/18, and 
 the weight-average molecular weight of the organopolysiloxane segment as a main chain is 10,000 to 100,000. 
 
   
   
       2 . A hair cosmetic comprising the organopolysiloxane according to  claim 1 . 
   
   
       3 . The hair cosmetic according to  claim 2  further comprising one or more organic solvents selected from the group consisting of the following (b1) to (b5):
 (b1) a compound represented by the general formula (2)   
     
       
         
         
             
             
         
       
     
     wherein R 2  represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a group R 3 -Ph-R 4 —, wherein R 3  represents a hydrogen atom, a methyl group, or a methoxy group; R 4  represents a bond or a saturated or unsaturated divalent hydrocarbon group having 1 to 3 carbon atoms; and Ph represents a paraphenylene group, A represents a bond or a saturated divalent hydrocarbon group having 1 to 4 carbon atoms, Y and Z each independently represent a hydrogen atom or a hydroxy group, and p and q each independently are an integer of 0 to 5, provided that when p=q=0, Z represents a hydroxy group, and R 2  is not either a hydrogen atom or a group R 3 -Ph-;
 (b2) N-alkylpyrrolidone or N-alkenylpyrrolidone in which an alkyl group or an alkenyl group having 1 to 18 carbon atoms binds to a nitrogen atom; 
 (b3) an alkylene carbonate having 2 to 4 carbon atoms; 
 (b4) a polypropylene glycol having a number-average molecular weight of 100 to 1000; and 
 (b5) a lactone or a cyclic ketone represented by the general formula (3), (4), or (5): 
 
     
       
         
         
             
             
         
       
     
     wherein X represents a methylene group or an oxygen atom, R 5  and R 6  represent substituents different from each other, and a and b each independently are 0 or 1. 
   
   
       4 . The hair cosmetic according to  claim 3 , wherein the organic solvent is at least one selected from dipropylene glycol, 1,3-butanediol, benzyl alcohol, phenoxyethanol, 2-benzyloxyethanol, propylene carbonate, and polypropylene glycol (number-average molecular weight, 300 to 500). 
   
   
       5 . The hair cosmetic according to  claim 3 , wherein the organic solvent is a lower alcohol having 1 to 6 carbon atoms. 
   
   
       6 . The hair cosmetic according to  claim 4  comprising an organic carboxylic acid which may have a hydroxy group or a salt thereof. 
   
   
       7 . The hair cosmetic according to  claim 6 , wherein the organic carboxylic acid which may have a hydroxy group is a hydroxycarboxylic acid having 2 to 6 carbon atoms. 
   
   
       8 . The hair cosmetic according to any one of  claims 2  to  7  further comprising a set polymer. 
   
   
       9 . The hair cosmetic according to  claim 6  or  7 , wherein the pH is 2.5 to 4.5 at 25° C. when diluted 20-fold by mass with water. 
   
   
       10 . The hair cosmetic according to any one of  claims 2  to  9 , which is a semisolid styling composition.