DIP Forming Latex Composition and DIP Formed Article

Abstract

A dip-forming latex composition comprising a conjugated diene rubber latex and an organic peroxide, wherein the residual effective activity of organic peroxide defined as the ratio of organic peroxide retaining reactivity to the whole organic peroxide contained in the latex composition is 35% or higher. The invention provides a dip-formed article, which exhibits good softness of touch and comfortable fittingness and excellent in tensile strength and resistance to flexing fatigue; which itself hardly suffers coloration especially when the article thereof is worn as a glove for continuous operation for a long time and is hard to reduce adhesiveness and following characteristics to hand while wearing it; and a dip-forming latex composition capable to give such an article by dip-forming thereof.

1 . A dip-forming latex composition comprising a conjugated diene rubber latex and an organic peroxide, wherein residual effective activity of organic peroxide, defined as a ratio of organic peroxide retaining reactivity to said whole organic peroxide included in the dip-forming latex composition, is 35% or higher. 
   
   
       2 . The dip-forming latex composition as set forth in  claim 1 , wherein a pH value of said latex composition is 9 or lower. 
   
   
       3 . The dip-forming latex composition as set forth in  claim 1 , wherein 10-hour half-life temperature of said organic peroxide is 150° C. or lower. 
   
   
       4 . The dip-forming latex composition as set forth in  claim 1 , wherein
 a content of said organic peroxide included in the latex composition is 0.01 to 5 parts by weight based on 100 parts by weight of solid content of said conjugated diene rubber latex.   
   
   
       5 . The dip-forming latex composition as set forth in  claim 1 , wherein
 said conjugated diene rubber latex is a carboxylated nitrile rubber latex.   
   
   
       6 . A dip-formed article obtained by dip-forming of the dip-forming latex composition as set forth in any one of  claims 1  to  5 . 
   
   
       7 . A dip-formed article obtained by dip-forming of the dip-forming latex composition as set forth in  claim 5 , wherein retention ratio of stress (%), defined as a ratio [(M100(6)/M100(0))×100] of initial tensile stress M100 (0) at 100% elongation and tensile stress M100(6) after 6 minutes of 100% elongation, is 50% or higher. 
   
   
       8 . The dip-formed article as set forth in  claim 7 , wherein
 latex particle in said carboxylated nitrile rubber latex included in said dip-forming latex composition is cross-linked within the particle.   
   
   
       9 . The dip-formed article as set forth in  claim 7 , wherein
 latex particle in said carboxylated nitrile rubber latex included in said dip-forming latex composition contains 50 to 90 wt % of insoluble content in methyl ethyl ketone.   
   
   
       10 . A dip-formed article obtained by dip-forming of a dip-forming latex composition comprising a carboxylated nitrile rubber latex and an organic peroxide, wherein
 retention ratio of stress, defined as a ratio [(M100(6)/M100(0))×100] of initial tensile stress M100(0) at 100% elongation and tensile stress M100(6) after 6 minutes of 100% elongation, is 50% or higher.   
   
   
       11 . The dip-formed article as set forth in  claim 10 , wherein
 latex particle in said carboxylated nitrile rubber latex included in said dip-forming latex composition is cross-linked within the particle.   
   
   
       12 . The dip-formed article as set forth in  claim 10 , wherein
 latex particle in said carboxylated nitrile rubber latex included in said dip-forming latex composition contains 50 to 90 wt % of insoluble content in methyl ethyl ketone.   
   
   
       13 . The dip-formed article as set forth in  claim 10 , wherein
 a content of said organic peroxide included in said dip-forming latex composition is 0.01 to 5 parts by weight based on 100 parts by weight of solid content of said carboxylated nitrile rubber latex.