In various embodiments, methods for producing aqueous polyisoprene latex from natural cis-1,4-polyisoprene are described. The natural cis-1,4-polyisoprene may be sourced from guayule scrubs. In various embodiments, the method comprises extracting guayule plant material to form a miscella, fractionating the miscella to a preliminary cement, diluting the preliminary cement to a cement for dispersing, dispersing the cement in an aqueous surfactant mixture under high shear to produce an emulsion, and de-solventizing the emulsion to produce an aqueous latex dispersion. The rubber solids level can then be adjusted by centrifugation and dilution in water to produce a final aqueous cis-1,4-polyisoprene latex.

In various embodiments, methods for producing aqueous polyisoprene latex from natural cis-1,4-polyisoprene are described. The natural cis-1,4-polyisoprene may be sourced from guayule scrubs. In various embodiments, the method comprises extracting guayule plant material to form a miscella, fractionating the miscella to a preliminary cement, diluting the preliminary cement to a cement for dispersing, dispersing the cement in an aqueous surfactant mixture under high shear to produce an emulsion, and de-solventizing the emulsion to produce an aqueous latex dispersion. The rubber solids level can then be adjusted by centrifugation and dilution in water to produce a final aqueous cis-1,4-polyisoprene latex.

A method for producing a polymer latex, including an emulsification step of mixing a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer in an organic solvent, with an aqueous solution including 0.1 to 30 parts by weight of a rosinate based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer, and emulsifying the resultant in water to thereby obtain an emulsified liquid, a solvent removal step of removing the organic solvent in the emulsified liquid, and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed, and also adjusting the content rate of the rosinate in the emulsified liquid after concentration, in the range of 0.1 to 3 parts by weight based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer in the emulsified liquid.

A method for producing a polymer latex, including an emulsification step of mixing a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer in an organic solvent, with an aqueous solution including 0.1 to 30 parts by weight of a rosinate based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer, and emulsifying the resultant in water to thereby obtain an emulsified liquid, a solvent removal step of removing the organic solvent in the emulsified liquid, and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed, and also adjusting the content rate of the rosinate in the emulsified liquid after concentration, in the range of 0.1 to 3 parts by weight based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer in the emulsified liquid.

A method for producing a polymer latex, including an emulsification step of mixing a polymer solution obtained by dissolution of synthetic polyisoprene and/or a styrene-isoprene-styrene block copolymer in an organic solvent, with an aqueous solution including 0.1 to 30 parts by weight of a rosinate based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer, and emulsifying the resultant in water to thereby obtain an emulsified liquid, a solvent removal step of removing the organic solvent in the emulsified liquid, and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed, and also adjusting the content rate of the rosinate in the emulsified liquid after concentration, in the range of 0.1 to 3 parts by weight based on 100 parts by weight in total of the synthetic polyisoprene and the styrene-isoprene-styrene block copolymer in the emulsified liquid.

A method for producing a polymer latex, includes: a stirring step of adding water to a polymer solution obtained by dissolution of a synthetic rubber in an organic solvent, to allow water to be stirred in the polymer solution, thereby providing a water-stirred polymer solution (A); an aqueous phase removal step of removing an aqueous phase from the water-stirred polymer solution (A), thereby providing an aqueous phase-removed polymer solution (B); an emulsification step of mixing the aqueous phase-removed polymer solution (B) with an aqueous solution including a surfactant, for emulsification in water, thereby obtaining an emulsified liquid (C); a solvent removal step of removing an organic solvent in the emulsified liquid (C); and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed (D).

A method for producing a polymer latex, includes: a stirring step of adding water to a polymer solution obtained by dissolution of a synthetic rubber in an organic solvent, to allow water to be stirred in the polymer solution, thereby providing a water-stirred polymer solution (A); an aqueous phase removal step of removing an aqueous phase from the water-stirred polymer solution (A), thereby providing an aqueous phase-removed polymer solution (B); an emulsification step of mixing the aqueous phase-removed polymer solution (B) with an aqueous solution including a surfactant, for emulsification in water, thereby obtaining an emulsified liquid (C); a solvent removal step of removing an organic solvent in the emulsified liquid (C); and a concentration step of concentrating the emulsified liquid from which the organic solvent is removed (D).

The present invention provides an effective method for fractionating rubber particles in natural rubber latex by particle size, and effective methods for transporting or preserving rubber particles. The present invention relates to a method for fractionating rubber particles in natural rubber latex by particle size, the method including centrifuging natural rubber latex in at least four stages at forces of 800 to 3,000g, 6,500 to 10,000g, 17,000 to 22,000g, and 40,000 to 60,000g to fractionate rubber particles. The present invention also relates to methods for transporting or preserving rubber particles, the methods including the steps of adding a buffer solution and an antioxidant to natural rubber latex or rubber particles fractionated from natural rubber latex; and freezing a mixture prepared in the above step.

The present invention provides an effective method for fractionating rubber particles in natural rubber latex by particle size, and effective methods for transporting or preserving rubber particles. The present invention relates to a method for fractionating rubber particles in natural rubber latex by particle size, the method including centrifuging natural rubber latex in at least four stages at forces of 800 to 3,000g, 6,500 to 10,000g, 17,000 to 22,000g, and 40,000 to 60,000g to fractionate rubber particles. The present invention also relates to methods for transporting or preserving rubber particles, the methods including the steps of adding a buffer solution and an antioxidant to natural rubber latex or rubber particles fractionated from natural rubber latex; and freezing a mixture prepared in the above step.

The present invention provides an effective method for fractionating rubber particles in natural rubber latex by particle size, and effective methods for transporting or preserving rubber particles. The present invention relates to a method for fractionating rubber particles in natural rubber latex by particle size, the method including centrifuging natural rubber latex in at least four stages at forces of 800 to 3,000g, 6,500 to 10,000g, 17,000 to 22,000g, and 40,000 to 60,000g to fractionate rubber particles. The present invention also relates to methods for transporting or preserving rubber particles, the methods including the steps of adding a buffer solution and an antioxidant to natural rubber latex or rubber particles fractionated from natural rubber latex; and freezing a mixture prepared in the above step.