Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – At least one aryl ring which is part of a fused or bridged...
Reexamination Certificate
2002-06-05
2004-05-11
Cheung, William (Department: 1713)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
At least one aryl ring which is part of a fused or bridged...
C524S306000, C524S311000, C524S312000, C524S313000, C524S504000, C524S563000, C524S567000, C524S568000, C524S569000
Reexamination Certificate
active
06734242
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a composition. In particular, the present invention relates to a composition comprising a pigment and a compound which acts as a dispersant, and methods for making and using the composition.
Liquid compositions containing a pigment typically require a dispersant to maintain the stability of the dispersant in the liquid carrier. Dispersants of the prior art have included adipates such as such as dioctyl adipate (DOA) and phthalate plasticisers such as dioctyl phthalate (DOP). The safety of these plasticisers has been called into question, particularly in certain applications and there is a desire to avoid their use.
Particular areas in which pigment dispersants have been used is in the provision of colourants for plastics, printing inks, and paints and lacquers.
As discussed in U.S. Pat. No. 5,308,395, traditionally, plastics have been coloured by tumble blending the plastic with a solid colourant or additive concentrate such as a colouring powder. The blended material is then fed into an extruder or moulding machine where the resin and the colourant are plasticised and the colourant is incorporated into the molten plastic. However, this method has a number of drawbacks. In many cases, a solid colourant or additive concentrate does not uniformly mix with plastic, or it does not disperse uniformly during moulding. Further, solid colourants often segregate from the plastic during pre-moulding handling because of particle size or specific gravity differences.
In recent years, liquid colour compositions have been developed in an effort to overcome the disadvantages of the traditional solid colourants. Being liquids, these colourant concentrates may be accurately metered directly into moulding machines or extruders by in-line metering systems, which help overcome many of the disadvantages of solid colourants.
As discussed in U.S. Pat. No. 5,531,819 printing inks are commonly used in ink jet printing systems. There have been proposed various kinds of ink jet recording systems, for example, a so-called electric field control system of jetting out ink by utilising an electrostatic attraction force; a so-called drop-on-demand system of jetting out ink by utilising a vibrational pressure of a piezo element (pressure pulse system); and a so-called thermal ink jet system of jetting out ink by utilising a pressure resulting from forming and growing bubbles by heating at high temperatures, and they can provide images of extremely high resolution.
For many ink jet systems, an aqueous ink using water as a main solvent and an oil ink using an organic solvent as a main solvent have generally been used. Printed images obtained by using the aqueous ink are generally poor in water proofing, whereas the oil ink can provide printed images of excellent waterproofing. U.S. Pat. No. 5,531,819 proposes plasticisers which may be used in oil inks.
As discussed in U.S. Pat. No. 4,230,609 pigments may also be delivered in the form of water reducible coatings. A water reducible coating is defined to be a colloidal dispersion in an organic solvent and water whose resin concentration can be reduced with water or solvent, which when reduced with a coalescing solvent forms a durable coating when applied to a substrate surface. Other names applied to water reducible coatings are water-borne, water solubilised, and water dilutable.
In a first aspect the present invention provides a composition comprising i) a pigment ii) a compound having the formula
wherein R
1
, R
2
and R
3
are independently selected from an acyl group or a hydrogen atom, wherein at least one of R
1
, R
2
and R
3
is an acyl group (a short acyl group) having from 2 to 5 carbon atoms, wherein at least one of R
1
, R
2
and R
3
is a branched chain acyl group (a long acyl group) consisting of a chain having 10 to 20 carbon atoms and a hydrophilic branch group.
The dispersant of the present invention is (i) cost effective as it may synthesised from readily available products, for example castor oil, (ii) produces a stable dispersion with a wide variety of organic and inorganic pigments and dyes, (iii) allows for high pigment loads, and/or (iv) possess good shelf stability and uniformity.
In one aspect the composition of the invention is a pigment composition for colouring a polymer. In this aspect further advantages are observed.
The dispersant is compatible with a wide variety of commercial thermoplastic resins, is suitable for use in conventional in-line metering and blending equipment, produces uniform colour finished products without visible streaks or specks, eliminates screw slippage and/or is stable at the temperatures normally encountered in plastics moulding and extrusion equipment.
In one aspect the composition of the invention is a pigment composition for an ink. In this aspect further advantages are observed. The composition of the invention allows the provision of a hot melt ink, which is optimum as an ink for hot melt type ink jet recording, capable of reducing the heat of fusion without increasing the viscosity of the ink as a whole, improving transparency, providing plasticity, reducing haze (representing the extent of cloud, also referred as cloudiness), providing luster and/or easily dissolving a dye as a colorant and capable of providing a sufficient solubility, particularly to a black or cyanine dye.
In one aspect the composition of the invention is, or is usable in, a water reducible coating. In this aspect further advantages are observed. The composition of the invention may (i) provide for lower solvent cost; (ii) lower the amount of organic solvent used to decrease atmospheric pollution; (iii) lower phase inversion viscosity—the point at which the organic solvent (to which mixture water is being added) changes from a water-in-oil dispersion to an oil-in-water dispersion. This would make mixing easier and would require less energy to make up the composition; (iv) increase the solids content of the composition, to give coatings offering improved protection to substrate surfaces, without at the same time thickening the material and making it difficult to apply; (v) act as a plasticiser and therefore allow for a decrease in the addition of further plasticiser which in some applications may be detrimental to the coating, being extractable from the coatings by solvents; (vi) decrease carboxyl group content of the resin to decrease further the water sensitivity of the final coating.
In one aspect, the present invention provides a composition as herein defined in a medium.
Dispersant
In the present specification by the term dispersant it is meant that the compound may assist in the dispersion of a pigment in a medium. The medium may be for example a carrier, a solvent or a solid such as a polymer.
Preferably two of R
1
, R
2
and R
3
are short acyl groups as described above and the other of R
1
, R
2
and R
3
is a long acyl group as described above. In this aspect, the compound may be of the formula
Preferably the hydrophilic branch group is a group selected from acyl and derivatives thereof. Preferred derivatives include groups of the formula —O—acyl.
Preferably the hydrophilic branch group is a group of the formula
wherein p is from 0 to 3.
In a preferred aspect of the present invention the chain of the long acyl group consists of a chain having 14 to 20 carbon atoms. In a more preferred aspect, the chain of the long acyl group consists of a chain having 16 to 20 carbon atoms.
Preferably the long acyl group is of the formula
wherein n is from 10 to 20 and m is selected from 2n, 2n-2, 2n-4 and 2n-6, and wherein p is from 0 to 3.
Preferably n is from 16 to 20, more preferably from 16 to 18, yet more preferably 17.
Preferably m is 2n or 2n-2.
Preferably the group CnHm is a straight chain hydrocarbon group. The straight chain hydrocarbon group may be saturated or unsaturated. In one aspect, the straight chain hydrocarbon group contains a single —C═C— bond.
In a highly preferred aspect the long acyl group is a group of the formula
wherein x is from 7 to 10, preferab
Nielsen Bjarne
Sparsø Flemming Vang
Cheung William
Danisco A/S
Frommer Lawrence & Haug
Kowalski Thomas J.
LandOfFree
Composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3228703