Aqueous synthetic resin dispersion

Claim 2

An aqueous synthetic resin dispersion having a minimum film forming temperature below 50° c. containing an emulsion polymer with a core/shell structure consisting of A) 65-90 percent by weigh of a weakly crosslinked core polymer having a glass transition temperature below 0° C. and an extension at break of at least 150 percent, said core polymer comprising 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) 0.1-2.0 percent, by weight of said core polymer, of at least one crosslinking monomer containing at least two no-conjugated ethylenically unsaturated, free radically polymerizable groups, and B) 10-35 percent by weight of an essentially non-crosslinked shell polymer having a glass transition temperature below 60° C., comprising 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature above 25° C., the glass transition temperature of said core polymer being at least 10 Centigrade degrees below that of said shell polymer. said shell polymer containing up to 20 percent by weight of monomers selected from the group consisting of acrylic acid, methacrylic acid, hydroxyalkyl esters of acrylic acid, hydroxyalkyl esters of methacrylic acid, acrylamide, methacrylamide, and N-alkyl derivatives thereof.

Claim 3

An synthetic resin dispersion having a minimum film forming temperature below 50° C., containing an emulsion polymer with a core/shell structure consisting of A) 65-90 percent by weigh of a weakly crosslinked core polymer having a glass transition temperature below 0° C. and an extension at reak of at least 150 percent at 23° C., said core polymer comprising 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) 0.1-2.0 percent by weight of at least one crosslinking monomer containing at least two ethylenically unsaturated, free radically polymerizable groups of which at least one is an allyl group, and B) 10-35 percent by weight of an essentially non-crosslinked shell polymer having a glass transition temperature below 60° C., comprising 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature above 25° C., the glass transition temperature of said core polymer being at least 10 Centigrade degrees below that of said shell polymer, said shell polymer containing up to 20 percent by weigh of monomers selected from eh group consisting of acrylic acid, methacrylic acid, hydroxyalkyl esters of acrylic acid, hydroxyalkyl esters of methacrylic acid, acrylamide, methacrylamide, and N-alkyl derivatives thereof.

Claim 4

An synthetic resin dispersion having a minimum film forming temperature below 50° C., containing an emulsion polymer with a core/shell structure consisting of A) 65-90 percent by weigh of a weakly crosslinked core polymer having a glass transition temperature below 0° C. and an extension at reak of at least 150 percent at 23° C., said core polymer comprising 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) 0.1-2.0 percent by weight of at least one crosslinking monomer containing at least two ethylenically unsaturated, free radically polymerizable groups of which at least one is an allyl group, and B) 10-35 percent by weight of an essentially non-crosslinked shell polymer having a glass transition temperature below 60° C., comprising 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature above 25° C., the glass transition temperature of said core polymer being at least 10 Centigrade degrees below that of said shell polymer, said shell polymer containing up to 20 percent by weigh of monomers selected from eh group consisting of acrylic acid, methacrylic acid, hydroxyalkyl esters of acrylic acid, hydroxyalkyl esters of methacrylic acid, acrylamide, methacrylamide, and N-alkyl derivatives thereof.

Claim 5

A method for the preparation of an aqueous dispersion of an emulsion polymer as in claim 1, which method comprises emulsion polymerizing, in a first stage, 65 to 90 percent, by weight of all monomers polymerized in said method, of a first monomer mixture comprising p1 1) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature below 25° C., and 2) at least one graft crosslinking monomer which contains at least two non-conjugated ethylenically unsaturated free radically polymerizable groups of which at least one is an allyl group, by gradually adding said mixture under polymerization conditions to an aqueous phase containing an emulsifier and a free radical forming initiator, whereby a latex of a core polymer si formed, and, in a second stage, emulsion polymerizing 10 to 35 percent, by weight of all monomers polymerized in said method, of a second monomer mixture comprising 1) at least one monoethylenically unsaturated, free radially polymerizable monomer, the homopolymers of which has a glass transition temperature below 25° C., and 2) at least one monoethylenically unsaturated, free radically polymerizable monomer, the homopolymer of which has a glass transition temperature above 25° C., by gradually adding said second monomer mixture under polymerization conditions to the latex of said core polymer formed in said fist stage, whereby a shell polymer is formed, the monomers present in said first and second monomer mixtures being such that the glass transition temperature of said core polymer is below 0° C., that of said shell polymer is below 60° C., and the glass transition temperature of said core polymer is at least 10 Centigrade degrees below the glass transition temperature of said shell polymer, said shell polymer containing up to 20 percent by weight of monomers selected from the group consisting of acrylic acid, methacrylic acid, hydroxyalkyl users of acrylic acid, hydroxyalkyl esters of methacrylic acid, acrylamide, methacrylamide, and N-alkyl derivatives thereof.

Claim 6

An aqueous synthetic resin dispersion as in claim 1 wherein said crosslinking monomer A) 2) contains at least three non-conjugated ethylenically unsaturated free radically polymerizable groups.

Claim 7

An aqueous synthetic resin dispersion as in claim 4 wherein said three non-conjugated groups are the same.

Claim 8

An aqueous synthetic resin dispersion as in claim 5 wherein said same three non-conjugated groups are selected from the group consisting of allyl, acryl, and methacryl groups.

Claim 9

An aqueous synthetic resin dispersion as in claim 1 wherein said crosslinking monomer A) 2) is triallyl cyanurate or triallyl isocyanurate.

Claim 10

An aqueous synthetic resin dispersion as in claim 1 wherein said crosslinking monomer A) 2) contains at least one allyl group.

Claim 11

An aqueous synthetic resin dispersion as in claim 1 wherein said crosslinking monomer A) 2) is free of allyl groups.

Claim 12

An aqueous synthetic resin dispersion as in claim 1 wherein the amount of crosslinking monomer A) 2) is such that the extension of said core polymer at break is at least 400 percent.

Claim 13

An aqueous synthetic resin dispersion as in claim 1 wherein the amount of crosslinking monomer A) 2) is such that the extension of said core polymer at break as is at least 600 percent.

Claim 14

An aqueous synthetic resin dispersion as in claim 1 which additionally contains a pigment.

Claim 15

An aqueous synthetic resin dispersion as in claim 1 wherein said core polymer additionally comprises at leas one further monoethylenically unsaturated monomer, different from but copolymerizable with the other monomers of said core polymer, and not capable of crosslinking.

Claim 16

An aqueous synthetic resin dispersion as in claim 1 wherein said shell polymer additionally comprises at least one further monoethylenically unsaturated monomer, different from burt copolymerizable with the other monomers of said shell polymer.

Claim 17

An aqueous synthetic resin dispersion as in claim 2 wherein at least one crosslinking monomer A) 2) is selected from the group consisting of allyl acrylate and allyl methacrylate.

Claim 18

An aqueous synthetic resin dispersion as in claim 2 wherein said crosslinking monomer A) 2) is triallylcyanurate.

Claim 19

An aqueous synthetic resin dispersion as in claim 2 wherein the amount of crosslinking monomer A) 2) is such that the extension of said core polymer at break is at least 400 percent.

Claim 20

An aqueous synthetic resin dispersion as in claim 2 wherein the amount of crosslinking monomer A) 2) is such that the extension of said core polymer at break is at least 600 percent.

Claim 21

An aqueous synthetic resin dispersion as in claim 2 which additionally contains a pigment.

Claim 22

An aqueous synthetic resin dispersion as in claim 2 wherein said core polymer additionally comprises at least one further monoethylenically unsaturated monomer, different from but copolymerizable with the other monomers of said core polymer, and not capable of crosslinking.

Claim 23

An aqueous synthetic resin dispersion as in claim 2 wherein said shell polymer additionally comprises at least one further monoethylenically unsaturated monomer, different from but copolymerizable with the other monomers of said shell polymer.

Claim 24

A method as in claim 3 wherein the monomer mixture polymerized in said first stage is dispersed in water.

Claim 25

A method as in claim 3 wherein the monomer mixture polymerized in said second stage is dispersed in water.

Claim 26

A method as in claim 3 wherein said first monomer mixture additionally comprises at least one further monoethylenically unsaturated monomer, different from but copolymerizable with the other monomers in said mixture and not capable of crosslinking.

Claim 27

A method as in claim 3 wherein said second monomer mixture additionally comprises at least one further monoethylenically unsaturated monomer, different from but copolymerizable with the other monomers in said mixture.