Ink compositions and writing instruments including the compositions

Claim 2

A water-fast, shock resistant shear-thinning ink composition consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of colorant material which is water insoluble when the composition is dry, c. 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 0.6, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing, and d. a water soluble polymeric binder material which is effective to improve the shock resistance of the composition and is water insoluble when the composition is dry in an amount ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning material, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 3

A composition of claim 1 where the viscosity at a shear rate of 30 sec -1 is 100 cPs or greater.

Claim 4

A composition of claim 1 where the shear thinning index is between about 0.05 to about 0.30.

Claim 5

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.

Claim 6

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 7

A composition of claim 1 where the binder material is present in an amount from about 0.1 to about 30.0 percent by weight.

Claim 8

A composition of claim 1 where the binder material is present in an amount from about 1 to about 20 percent by weight.

Claim 9

A composition of claim 1 where the binder material is water soluble when maintained at a given pH range and water insoluble when not maintained at that range.

Claim 10

A composition of claim 8 where the shear-thinning providing material is xanthan gum.

Claim 11

A composition of claim 8 where the binder material is an acrylic polymer having a carboxyl functionality between about 3 to about 15 percent.

Claim 12

A composition of claim 1 where the composition includes from about 5 to about 15 percent by weight of binder material and from about 0.5 to about 1.0 percent by weight xanthan gum.

Claim 13

A composition of claim 1 where the polar solvent system comprises a minor proportion of a polar solvent other than water.

Claim 14

A composition of claim 1 where the polar solvent system includes glycerol, ethylene glycol, propylene glycol or mixtures of these.

Claim 15

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

Claim 16

A composition of claim 1 including a drying and levelling agent which is a fluorinated polysilane surface active agent.

Claim 17

A water-fast, shock resistant, shear-thinning ink composition having a shear-thinning index between about 0.01 to about 0.60, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing and consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of a colorant material which is water insoluble when the composition is dry, c. from about 0.1 to about 5 percent by weight of a polymeric, shear-thinning material selected from the group consisting of xanthan gum, carageenan gum, locust bean gum, hydroxyethylcellulose, guar gum or mixtures of these, and d. from about 1 to about 20 percent by weight of a binder material which is water soluble when maintained at a given pH range and water insoluble when not maintained at that pH range and which is effective to improve the shock resistance of the composition, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 18

A water-fast, shock resistant, shear-thinning ink composition having a shear-thinning index between about 0.01 to about 0.60, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing and consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of a colorant material which is water insoluble when the composition is dry, c. from about 0.1 to about 5 percent by weight of a polymeric, shear-thinning material selected from the group consisting of xanthan gum, carageenan gum, locust bean gum, hydroxyethylcellulose, guar gum or mixtures of these, and d. from about 1 to about 20 percent by weight of a binder material which is water soluble when maintained at a given pH range and water insoluble when not maintained at that pH range and which is effective to improve the shock resistance of the composition, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 19

A composition of claim 16 where the viscosity at 30 sec -1 is 100 cPs or greater.

Claim 20

A composition of claim 16 where the binder material is an acrylic polymer having a carboxyl functionality between about 3 to about 15 percent.

Claim 21

A composition of claim 18 where the shear-thinning material is xanthan gum.

Claim 22

A ball point pen comprising a reservoir including a water-fast, shock resistant, shear-thinning ink composition consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of colorant material which is water insoluble when the composition is dry, c. 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 0.6, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing, and d. a water soluble polymeric binder material which is effective to improve the shock resistance of the composition and is water insoluble when the composition is dry in an amount ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning material, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 23

A ball point pen comprising a reservoir including a water-fast, shock resistant, shear-thinning ink composition consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of colorant material which is water insoluble when the composition is dry, c. 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 0.6, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing, and d. a water soluble polymeric binder material which is effective to improve the shock resistance of the composition and is water insoluble when the composition is dry in an amount ineffective to substantially affect the shear-thinning capability of the polymeric shear-thinning material, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 24

A ball-point pen of claim 20 where the viscosity at a shear rate of 30 sec -1 is 100 cPs or greater.

Claim 25

A ball-point pen of claim 20 where the shear-thinning index is between about 0.05 to about 0.30.

Claim 26

A ball-point pen of claim 20 where the shear-thinning material is present in an amount between about 0.1 to about 5 percent by weight.

Claim 27

A ball-point pen of claim 20 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 28

A ball-point pen of claim 20 where the binder material is present in an amount from about 0.1 to about 30 percent by weight.

Claim 29

A ball-point pen of claim 20 where the binder material is present in an amount from about 1 to about 20 percent by weight.

Claim 30

A ball-point pen of claim 20 where the binder material is water soluble when maintained at a given pH range and water insoluble when not maintained at that range.

Claim 31

A ball-point pen of claim 27 where the binder material is an acrylic polymer having a carboxyl functionality between about 3 to about 15 percent.

Claim 32

A ball-point pen of claim 28 where the shear-thinning providing material is xanthan gum.

Claim 33

A writing instrument of claim 20 where the composition includes from about 5 to about 15 percent by weight of binder material and from about 0.5 to about 1 percent by weight xanthan gum.

Claim 34

A writing instrument of claim 20 where the polar solvent system comprises a minor proportion of a polar solvent other than water.

Claim 35

A writing instrument of claim 20 where the polar solvent system includes glycerol, ethylene glycol, propylene glycol or mixtures of these.

Claim 36

A writing instrument of claim 20 including a drying and levelling agent.

Claim 37

A writing instrument of claim 20 including a drying and levelling agent which is a fluorinated polysilane surface active agent.

Claim 38

A writing instrument of claim 20 where a viscoelastic ink follower is included in the reservoir.

Claim 39

A ball-point pen comprising a reservoir including a water-fast, shock resistant, shear-thinning ink composition having L a shear-thinning index between about 0.01 to about 0.60, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing and consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of a colorant material which is water insoluble when the composition is dry, c. from about 0.1 to about 5 percent by weight of a polymeric, shear-thinning material selected from the group consisting of xanthan gum, carageenan gum, locust bean gum, hydroxyethylcellulose, guar gum or mixtures of these, and d. from about 1 to about 20 percent by weight of a binder material which is water soluble when maintained at a given pH range and water insoluble when not maintained at that pH range and which is effective to improve the shock resistance of the composition, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 40

A ball-point pen comprising a reservoir including a water-fast, shock resistant, shear-thinning ink composition having L a shear-thinning index between about 0.01 to about 0.60, a viscosity of 50 cPs or greater at a shear rate of 30 sec -1 and a viscosity of 100 cPs or less at shear rates produced by writing and consisting essentially of: a. from about 50 to about 99 percent by weight of a polar solvent system including at least about 50 percent by weight water, b. an effective amount of a colorant material which is water insoluble when the composition is dry, c. from about 0.1 to about 5 percent by weight of a polymeric, shear-thinning material selected from the group consisting of xanthan gum, carageenan gum, locust bean gum, hydroxyethylcellulose, guar gum or mixtures of these, and d. from about 1 to about 20 percent by weight of a binder material which is water soluble when maintained at a given pH range and water insoluble when not maintained at that pH range and which is effective to improve the shock resistance of the composition, said composition providing a colored, water insoluble coalesced residue on drying.

Claim 41

A ball-point pen of claim 36 where the viscosity at a shear rate of 30 sec -1 is 100 cPs or greater.

Claim 42

A ball-point pen of claim 36 where the binder material is an acrylic polymer having a carboxyl functionality between about 3 to about 15 percent.

Claim 43

A ball-point pen of claim 36 where a viscoelastic ink follower is included in the reservoir.