Abstract: A synthetic polyisoprene copolymer is manufactured by stirring a synthetic polyisoprene rubber latex under the heating condition of 50° C. or higher, purifying the latex by centrifugation, adding a vinyl monomer to the purified synthetic polyisoprene rubber latex obtained and graft-copolymerizing the vinyl monomer. The synthetic polyisoprene copolymer is a copolymer in which a vinyl monomer is graft-copolymerized on the surface of synthetic polyisoprene particles, and which has a nanomatirx structure in which the synthetic polyisoprene rubber particles are dispersed in a continuous phase having a thickness of from 1 to 100 nm formed by graft chains in a phase-separated state.

Abstract: 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.

Abstract: 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 ?g/g as measured by an improved Lowry method.

Abstract: 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.

Abstract: 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 ?g/g as measured by an improved Lowry method.

Abstract: 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.

Abstract: Double bonds, which are included in the respective isoprene units of natural rubber, are converted into epoxy groups, and are subsequently converted into hydroxyl groups by hydrolyzing the resulting epoxy groups. Since it is possible to introduce hydroxyl groups into all of the double bonds securely, and moreover since it is possible to introduce many hydroxyl groups into them, it is possible to utilize the setting for films for food packaging that are good in terms of gas non-permeability.

Abstract: This invention provides a novel polymeric compound having excellent gas permeability, oil resistance, stability, and molding proccessability and a method for producing the same. The novel polymeric compound is a cyclic carbonate-containing polymeric compound represented by formula (I).

Abstract: The present invention provides a method for mass-producing deproteinized natural rubber latex that does not substantially contain allergy-provoking proteins and peptides in a cost-effective manner at industrial levels. This method comprises steps of: adding a urea denaturing agent for proteins and a surfactant to raw natural rubber latex; mixing these substances while transporting the same through a fluid channel to denature proteins in raw natural rubber latex; and separating and removing the denatured proteins.

Abstract: A clip includes a fastener unit and a leg unit, the fastener unit having a pair of support plates projecting in parallel from the underside of a trim plate to be fastened and being formed at their distal ends with slits and a pair of engagement members provided on the outer surfaces of the support plates, and the leg unit having a pair of parallel wall plates formed on upper inner surface portions with steps for engaging with the engagement members of the fastener unit and a base connecting the wall plates and formed with a pair of opposing elastic legs at positions spaced from the wall plates and with lugs for engagement with the slits.