Surfactant system for ink jet inks for printing on hydrophobic surfaces

Claim 2

An ink jet ink composition comprising: (a) an aqueous carrier medium; (b) a colorant comprising a pigment and a polymeric dispersant; and (c) 2.5 to 6%, based on the total weight of the ink composition, of a mixture of surfactants consisting essentially of (i) at least one siloxane surfactant selected from the group consisting of (1) a polyether modified siloxane of the formula: ##STR5## wherein R'=methyl; R"=hydrocarbon chain and R 1 =H for ethylene oxide, CH 3 for propylene oxide (2) a nonionic siloxane polyoxyalkylene copolymer, wherein each copolymer contains a siloxane polymer and at least one oxyalkylene polymer, comprising from 5% to 95% by weight of the block copolymer and having the general formula: (R')(SiO.sub.3).sub.x (R.sub.2 SiO).sub.y (C.sub.n H.sub.2n O).sub.z R"!.sub.a R'"!.sub.3x-a wherein R' is a hydrocarbon radical having a valence of x; R and R" are monovalent hydrocarbon radicals, R'" is a member of the group consisting of alkyl radicals and R 2 Si-radicals; x≧1; y≧3;n=2-4; 1≧a≦3x and z≧2,and (3) block copolymers composed of: (A) at least one siloxane unit represented by the formula: R.sub.b SiO.sub.(4-b) wherein R contains from one to about twenty-two carbon atoms inclusive and is selected from the class consisting of monovalent hydrocarbon groups and divalent hydrocarbon groups, and b has a value from 1 to 3 inclusive; said siloxane block containing at least one of said siloxane units wherein at least one R group is a divalent hydrocarbon group and (B) at least one oxyalkylene block containing at least two oxyalkylene groups represented by the formula: --R'O-- wherein R' is an alkylene group containing from 2 to about 10 carbon atoms inclusive said siloxane and oxyalkylene blocks being interconnected by said divalent hydrocarbon group; (ii) at least one fluorinated surfactant of the formula: R(f)Q!.sub.n A wherein, R(f) is F(CF 2 CF 2 ) 3-8 ; Q is selected from the group consisting of CH 2 CH 2 SCH 2 CH 2 and CH 2 CH 2 ; A is a water soluble group selected from the group consisting of CO 2 A; PO 4 (A) 2 ; PO 4 A and (OCH 2 CH 2 ) x OH, where A is a counterion and x is 1-10; and n is 1 or 2; (iii) wherein the at least one siloxane surfactant is present in the amount of 15 to 75% by weight, based on the total weight of the surfactant mixture.

Claim 3

The inkjet ink composition of claim 1 wherein the mixture of surfactants is present in the amount of 3 to 4.5% by weight, based on the total weight of the ink composition.

Claim 4

The ink jet ink composition of claim 1 wherein the siloxane surfactant is a nonionic siloxane polyoxyalkylene copolymer comprising a mixture of block copolymers wherein each copolymer contains a siloxane polymer and three oxyalkylene polymers in combination, and wherein each copolymer has the general formula: ##STR6## wherein R, R' and R" are monovalent hydrocarbon radicals, p, q, and r are integers each having a value of at least 1, n=2 to 4, and z≧2.

Claim 5

The ink jet ink composition of claim 1 wherein the siloxane surfactant has the formula: ##STR7## wherein R' is alkyl radicals of 1 to 4 carbon atoms, x is 4 to 60, a+b=1 to x, and a≧b.

Claim 6

The ink jet ink composition of claim 1 wherein the siloxane surfactant has the formula: ##STR8## wherein R is hydrogen or alkyl radical of 1 to 4 carbon atoms, a is 1 to 30, b is 0 to 30, x+y=4 to 60 where x 3 y and y 3 1.

Claim 7

The ink jet ink composition of claim 1 wherein the surfactant mixture comprises 45 to 55% by weight siloxane surfactant.

Claim 8

The ink jet ink composition of claim 1 wherein the fluorinated surfactant has a solubility, in the aqueous carrier medium, of at least 0.01% at 25° C.

Claim 9

The inkjet ink composition of claim 1 wherein the fluorinated surfactant is telomer B monoether with polyethylene glycol.

Claim 10

The ink jet ink composition of claim 1 wherein the fluorinated surfactant is a fluoroalkyl alcohol substituted monoether with polyethylene glycol.

Claim 11

A process of printing an image on an untreated hydrophobic substrate comprising the step of ejecting an ink jet ink composition from an air brush sprayer onto a hydrophobic substrate, wherein said ink jet ink composition comprises: (a) an aqueous carrier medium; (b) a colorant comprising a pigment and a polymeric dispersant; and (c) 2.5 to 6%, based on the total weight of the ink composition, of a mixture of surfactants consisting essentially of (i) at least one siloxane surfactant selected from the group consisting of (1) a polyether modified siloxane of the formula: ##STR9## wherein R'=methyl; R"=hydrocarbon chain, and R 1 =H for ethylene oxide, CH 3 for propylene oxide (2) a nonionic siloxane polyoxyalkylene copolymer, wherein each copolymer contains a siloxane polymer and at least one oxyalkylene polymer, comprising from 5% to 95% by weight of the block copolymer and having the general formula: (R')(SiO.sub.3).sub.x (R.sub.2 SiO).sub.y (C.sub.n H.sub.2n O).sub.z R"!.sub.a R'"!.sub.3x-a wherein R' is a hydrocarbon radical having a valence of x; R and R" are monovalent hydrocarbon radicals, R'" is a member of the group consisting of alkyl radicals and R 2 Si-radicals; x≧1; y≧3;n=2-4; 1≦a≧3x, and z≧2;and (3) block copolymers composed of: (A) at least one siloxane unit represented by the formula: R.sub.b SiO.sub.(4-b) wherein R contains from one to about twenty-two carbon atoms inclusive and is selected from the class consisting of monovalent hydrocarbon groups and divalent hydrocarbon groups, and b has a value from 1 to 3 inclusive; said siloxane block containing at least one of said siloxane units wherein at least one R group is a divalent hydrocarbon group, and (B) at least one oxyalkylene block containing at least two oxyalkylene groups represented by the formula: --R'O-- wherein R' is an alkylene group containing from 2 to about 10 carbon atoms inclusive, said siloxane and oxyalkylene blocks being interconnected by said divalent hydrocarbon group; (ii) at least one fluorinated surfactant of the formula: R(f)Q!.sub.n A wherein, R(f) is F(CF 2 CF 2 ) 3-8 ; Q is selected from the group consisting of CH 2 CH 2 SCH 2 CH 2 and CH 2 CH 2 ; A is a water soluble group selected from the group consisting of CO 2 A; PO 4 (A) 2 ; PO 4 A; and (OCH 2 CH 2 ) x OH, where A is a counterion and x is 1-10; and n is 1 or 2; (iii) wherein the at least one siloxane surfactant is present in the amount of 15 to 75% by weight, based on the total weight of the surfactant mixture.

Claim 12

A process of printing an image on an untreated hydrophobic substrate comprising the step of ejecting an ink jet ink composition from an air brush sprayer onto a hydrophobic substrate, wherein said ink jet ink composition comprises: (a) an aqueous carrier medium; (b) a colorant comprising a pigment and a polymeric dispersant; and (c) 2.5 to 6%, based on the total weight of the ink composition, of a mixture of surfactants consisting essentially of (i) at least one siloxane surfactant selected from the group consisting of (1) a polyether modified siloxane of the formula: ##STR9## wherein R'=methyl; R"=hydrocarbon chain, and R 1 =H for ethylene oxide, CH 3 for propylene oxide (2) a nonionic siloxane polyoxyalkylene copolymer, wherein each copolymer contains a siloxane polymer and at least one oxyalkylene polymer, comprising from 5% to 95% by weight of the block copolymer and having the general formula: (R')(SiO.sub.3).sub.x (R.sub.2 SiO).sub.y (C.sub.n H.sub.2n O).sub.z R"!.sub.a R'"!.sub.3x-a wherein R' is a hydrocarbon radical having a valence of x; R and R" are monovalent hydrocarbon radicals, R'" is a member of the group consisting of alkyl radicals and R 2 Si-radicals; x≧1; y≧3;n=2-4; 1≦a≧3x, and z≧2;and (3) block copolymers composed of: (A) at least one siloxane unit represented by the formula: R.sub.b SiO.sub.(4-b) wherein R contains from one to about twenty-two carbon atoms inclusive and is selected from the class consisting of monovalent hydrocarbon groups and divalent hydrocarbon groups, and b has a value from 1 to 3 inclusive; said siloxane block containing at least one of said siloxane units wherein at least one R group is a divalent hydrocarbon group, and (B) at least one oxyalkylene block containing at least two oxyalkylene groups represented by the formula: --R'O-- wherein R' is an alkylene group containing from 2 to about 10 carbon atoms inclusive, said siloxane and oxyalkylene blocks being interconnected by said divalent hydrocarbon group; (ii) at least one fluorinated surfactant of the formula: R(f)Q!.sub.n A wherein, R(f) is F(CF 2 CF 2 ) 3-8 ; Q is selected from the group consisting of CH 2 CH 2 SCH 2 CH 2 and CH 2 CH 2 ; A is a water soluble group selected from the group consisting of CO 2 A; PO 4 (A) 2 ; PO 4 A; and (OCH 2 CH 2 ) x OH, where A is a counterion and x is 1-10; and n is 1 or 2; (iii) wherein the at least one siloxane surfactant is present in the amount of 15 to 75% by weight, based on the total weight of the surfactant mixture.