Nagaoka University of Technology

Tokai Rubber Industries, Ltd.

Seiichi Kawahara

Yoshimasa Yamamoto

Akihiro Shibahara

Osamu Wakisaka

Nanthaporn Pukkate

Oraphin Chaikumpollert

Phan Trung Nghia

A modified natural rubber particle having carbon-carbon double bands assigned to multifunctional vinyl monomers graft-copolymerized onto the surface of the modified natural rubber particle, which is prepared by graft-copolymerization of multifunctional vinyl monomers having two or more carbon-carbon double bonds onto natural rubber particles or deproteinized natural rubber particles. One of the methods for producing a modified natural rubber particle includes the steps of: forming inclusion complex of the multifunctional vinyl monomers having two or more carbon-carbon double bonds with a guest-protecting agent to protect at least one of the double bonds of the multifunctional vinyl monomers; graft-copolymerizing the resulting inclusion complex onto natural rubber particles or deproteinized natural rubber particles; and deprotecting the protected double bonds by removing the guest-protecting agent from the obtained graft-copolymer.

Modified natural rubber particle, production method thereof, and modified natural rubber latex

Provided is a protein-free natural rubber for which the risk of inducing allergic reactions is extremely low. Also provided are a latex of said rubber and a method for efficiently manufacturing said rubber and latex. In the provided manufacturing method, a urea compound, a surfactant, and a polar organic solvent are added to a natural rubber latex, and the proteins in said latex are denatured and then removed. This results in a protein-free rubber latex having a nitrogen content of at most 0.001% as measured by an RRIM test. Also, the amount of protein in a solid rubber obtained by drying the provided natural rubber latex is at most 0.5 &#x3bc;g/g as measured by an improved Lowry method.

Protein-free natural rubber, latex thereof, and method for manufacturing said rubber and latex

A modified natural rubber particle having carbon-carbon double bonds assigned to multifunctional vinyl monomers graft-copolymerized onto the surface of the modified natural rubber particle, which is prepared by graft-copolymerization of multifunctional vinyl monomers having two or more carbon-carbon double bonds onto natural rubber particles or deproteinized natural rubber particles. One of the methods for producing a modified natural rubber particle includes the steps of: forming inclusion complex of the multifunctional vinyl monomers having two or more carbon-carbon double bonds with a guest-protecting agent to protect at least one of the double bonds of the multifunctional vinyl monomers; graft-copolymerizing the resulting inclusion complex onto natural rubber particles or deproteinized natural rubber particles; and deprotecting the protected double bonds by removing the guest-protecting agent from the obtained graft-copolymer.

Growing community of inventors

Nagaoka, Japan

Seiichi Kawahara