Shock resistant ink compositions and writing instruments including the compositions

Claim 2

A shock-resistant, shear-thinning ink composition having a viscosity no greater than about 100 m Pa.s at shear rates produced by writing and consisting essentially of from about 50 to about 99 percent by weight of the composition of a polar solvent system including at least about 50 percent by weight water, an effective amount of colorant material, an amount of a water dispersible polymeric shear-thinning material sufficient to provide an ink having a shear thinning index between about 0.01 to about 0.60 and an amount of a substantially water insoluble polymeric, shock resistant providing material effective to provide shock-resistance for the ink composition but ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning providing material.

Claim 3

A composition of claim 1 where the ink has a shear-thinning index between about 0.05 to about 0.30.

Claim 4

A composition of claim 1 where the shear-thinning material is present in an amount between about 0.1 to about 5 percent by weight of the composition.

Claim 5

A composition of claim 1 where the shear-thinning material comprises xanthan gum or carageenan gum or locust bean gum or hydroxyethylcellulose or guar gum or mixtures of these.

Claim 6

A composition of claim 1 where the polymeric, shock resistant providing material is a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 7

A composition of claim 1 where the polymeric, shock resistant providing material is present in an amount from about 1 to about 50 percent by weight of the composition.

Claim 8

A composition of claim 1 where the polymeric, shock resistant providing material is present in an amount from about 5 to about 30 percent by weight of the composition.

Claim 9

A composition of claim 1 where the colorant material is substantially water insoluble.

Claim 10

A composition of claim 8 where the polymeric, shock resistant providing material is a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 11

A composition of claim 9 where the shear-thinning material is xanthan gum.

Claim 12

A composition of claim 1 where the shear thinning material is xanthan gum in an amount between about 0.01 to about 5 percent by weight and the polymeric, shock resistant providing material is a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these in an amount between about 5 to about 30 percent by weight of the composition.

Claim 13

A composition of claim 1 where the colorant material is substantially water soluble.

Claim 14

A composition of claim 1 where the polar solvent system comprises a mixture of at least about 50 percent by weight of water and the remainder comprises at least one polar solvent other than water.

Claim 15

A composition of claim 13 where the polar solvent other than water is glycerol, ethylene glycol, propylene glycol or mixtures of these.

Claim 16

A composition of claim 1 including a drying and levelling agent.

Claim 17

A composition of claim 15 where the drying and levelling agent is a fluorinated polysilane surface active agent, a glycol ether, a glycol ether acetate, a glycol acetate or mixtures of these.

Claim 18

A shock-resistant, shear-thinning ink composition having a viscosity less than about 100 m Pa.s at shear rates produced by writing and consisting essentially of from about 50 to about 99 percent by weight of the composition of a polar solvent system including at least about 50 percent by weight water, and effective amount of colorant material, from about 0.1 to about 5 percent by weight of xanthan gum and from about 5 to about 30 percent by weight of a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 19

A shock-resistant, shear-thinning ink composition having a viscosity less than about 100 m Pa.s at shear rates produced by writing and consisting essentially of from about 50 to about 99 percent by weight of the composition of a polar solvent system including at least about 50 percent by weight water, and effective amount of colorant material, from about 0.1 to about 5 percent by weight of xanthan gum and from about 5 to about 30 percent by weight of a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 20

A composition of claim 16 where the colorant material is substantially water insoluble.

Claim 21

A writing instrument comprising a reservoir including a shock-resistant, shear-thinning ink composition having a viscosity no greater than about 100 m Pa.S at shear rates produced by writing and consisting essentially of from about 50 to about 99 percent by weight of the composition of a polar solvent system including at least about 50 percent by weight water, an effective amount of colorant material, an amount of a water dispersible polymeric shear-thinning material sufficient to provide an ink having a shear-thinning index between about 0.01 to about 0.60 and an amount of a substantially water insoluble polymeric, shock resistant providing material effective to provide shock-resistance the ink composition but ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning providing material.

Claim 22

A writing instrument comprising a reservoir including a shock-resistant, shear-thinning ink composition having a viscosity no greater than about 100 m Pa.S at shear rates produced by writing and consisting essentially of from about 50 to about 99 percent by weight of the composition of a polar solvent system including at least about 50 percent by weight water, an effective amount of colorant material, an amount of a water dispersible polymeric shear-thinning material sufficient to provide an ink having a shear-thinning index between about 0.01 to about 0.60 and an amount of a substantially water insoluble polymeric, shock resistant providing material effective to provide shock-resistance the ink composition but ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning providing material.

Claim 23

A writing instrument of claim 19 where the ink has a shear-thinning index between about 0.05 to about 0.30.

Claim 24

A writing instrument of claim 19 where the shear-thinning material of the ink is present in an amount between about 0.1 to about 5 percent by weight of the ink composition.

Claim 25

A writing instrument of claim 19 where the shear-thinning material of the ink comprises xanthan gum or carageenan gum or locust bean gum or hydroxyethylcellulose or guar gum or mixtures of these.

Claim 26

A writing instrument of claim 19 where the polymeric, shock resistant providing material of the ink is a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 27

A writing instrument of claim 19 where the polymeric, shock resistant providing material in the ink is present in an amount from about 1 to about 50 percent by weight of the ink composition.

Claim 28

A writing instrument of claim 19 where the polymeric, shock resistant providing material in the ink is present in an amount from about 5 to about 30 percent by weight of the ink composition.

Claim 29

A writing instrument of claim 19 where the colorant material in the ink is substantially water soluble.

Claim 30

A writing instrument of claim 26 where the polymeric, shock resistant providing material of the ink is a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 31

A writing instrument of claim 27 where the shear-thinning material in the ink is xanthan gum in an amount between about 0.01 to about 5 percent by weight and the polymeric, shock resistant providing material is a styrene polymer, a styrene-butadiene polymer, an acrylic polymer, an ethylene vinyl chloride polymer, a urethane polymer, a vinyl acetate polymer or mixtures of these.

Claim 32

A writing instrument of claim 19 where the colorant material in the ink is substantially water soluble.

Claim 33

A writing instrument of claim 19 where the polar solvent system of the ink comprises a mixture of at least about 50 percent by weight water and the remainder comprises at least one polar solvent other than water.

Claim 34

A writing instrument of claim 30 where the polar solvent other than water is glycerol, ethylene glycol, propylene glycol or mixtures of these.

Claim 35

A writing instrument of claim 19 where the ink includes a drying and levelling agent.

Claim 36

A writing instrument of claim 32 where the drying and levelling agent is a fluorinated polysilane surface active agent.

Claim 37

A writing instrument of claim 19 where a viscoelastic ink follower is included in the reservoir.