The invention relates to an aqueous polymer dispersion comprising: a) an aqueous polymer dispersion comprising grafted rubber polymeric particles from rubber polymer being selected from natural or synthetic rubber, b) an aqueous polymer dispersion with polymeric particles of a second polymer comprising monomeric units derived front a monomeric composition b) comprising: b1) a (meth)acrylate of a linear or branched alcohol in C.sub.4 to C.sub.10 or a mixture of such (meth)acrylates, said (meth)acrylate having Tg.sub.b1 lower than 30 C., b2) optionally, at least one comonomer having Tg.sub.b2 higher than 30 C.,
with said grafted rubber polymeric particles being grafted in an aqueous dispersion by a part of said monomeric composition b) as defined above. The invention covers a process of preparation of said dispersion, an adhesive composition comprising said dispersion, the use of said dispersion in pressure sensitive adhesives, and the resulting adhesive.

The present invention provides a method for preparing a graft copolymer for the application in a resin composition including a graft copolymer and a matrix resin, and relates to a method for preparing a graft copolymer maintaining impact properties such as impact strength and falling ball impact strength to the same or better levels, while improving flowability and subsequently improving processability, a graft copolymer prepared by the method and a resin composition including same.

The present invention provides a method for preparing a graft copolymer for the application in a resin composition including a graft copolymer and a matrix resin, and relates to a method for preparing a graft copolymer maintaining impact properties such as impact strength and falling ball impact strength to the same or better levels, while improving flowability and subsequently improving processability, a graft copolymer prepared by the method and a resin composition including same.

A natural rubber-containing thermoplastic resin composition includes a graft copolymer (A) obtained by graft-polymerizing a vinyl monomer mixture (a) including at least an aromatic vinyl monomer to a rubbery polymer (R) composed of 10 to 70% by mass of a natural rubber having a weight average particle size of 0.3 to 1.2 m and 30 to 90% by mass of a synthetic rubber having a weight-average particle size of 0.2 to 0.4 m, wherein particles of the natural rubber include not less than 5% by mass of natural rubber articles with a size of 1.0 m or larger; and particles of the rubbery polymer (R) with a size of 1.0 m or larger have an internal graft ratio of 20% or higher.

A natural rubber-containing thermoplastic resin composition includes a graft copolymer (A) obtained by graft-polymerizing a vinyl monomer mixture (a) including at least an aromatic vinyl monomer to a rubbery polymer (R) composed of 10 to 70% by mass of a natural rubber having a weight average particle size of 0.3 to 1.2 m and 30 to 90% by mass of a synthetic rubber having a weight-average particle size of 0.2 to 0.4 m, wherein particles of the natural rubber include not less than 5% by mass of natural rubber articles with a size of 1.0 m or larger; and particles of the rubbery polymer (R) with a size of 1.0 m or larger have an internal graft ratio of 20% or higher.

A curable resin composition that includes a curable resin (A) and acrylic rubber particles (B), the acrylic rubber particles (B) having a multilayer structure of two or more layers including an inner layer that includes a crosslinked rubber polymer having an acrylic acid ester unit, and an outermost layer that includes a hard polymer, the outermost layer of the acrylic rubber particles (B) having a thickness of 3.5 nm or more. Also an adhesive and a curing agent each including the curable resin composition, and a cured article of the curable resin composition.

A curable resin composition that includes a curable resin (A) and acrylic rubber particles (B), the acrylic rubber particles (B) having a multilayer structure of two or more layers including an inner layer that includes a crosslinked rubber polymer having an acrylic acid ester unit, and an outermost layer that includes a hard polymer, the outermost layer of the acrylic rubber particles (B) having a thickness of 3.5 nm or more. Also an adhesive and a curing agent each including the curable resin composition, and a cured article of the curable resin composition.

Provided is a method of preparing a graft polymer, which includes: adding a diene-based rubber polymer, a first monomer mixture including a (meth)acrylate-based monomer and an aromatic vinyl-based monomer, and a reactive ultraviolet (UV) stabilizer to a reactor and carrying out polymerization to prepare a composite rubber polymer; and graft-polymerizing a second monomer mixture including a (meth)acrylate-based monomer, an aromatic vinyl-based monomer, and a vinyl cyanide-based monomer to the composite rubber polymer to prepare a graft polymer, wherein the reactive UV stabilizer is added in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the sum of the diene-based rubber polymer, the first monomer mixture, and the second monomer mixture.

Provided is a method of preparing a graft polymer, which includes: adding a diene-based rubber polymer, a first monomer mixture including a (meth)acrylate-based monomer and an aromatic vinyl-based monomer, and a reactive ultraviolet (UV) stabilizer to a reactor and carrying out polymerization to prepare a composite rubber polymer; and graft-polymerizing a second monomer mixture including a (meth)acrylate-based monomer, an aromatic vinyl-based monomer, and a vinyl cyanide-based monomer to the composite rubber polymer to prepare a graft polymer, wherein the reactive UV stabilizer is added in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the sum of the diene-based rubber polymer, the first monomer mixture, and the second monomer mixture.