Abstract:
A thermally-responsive dispersant for an aqueous dispersion of positively- or negatively-charged or chargeable solid or liquid particulates, comprises a compound having an anchoring moiety linked to a thermally-responsive polymeric stabilizing moiety, other than a polyalkylene oxide, the polymeric moiety having a lower affinity for the surface than the anchoring group below the thermal transition temperature, the particulates being positively-charged or chargeable when the anchoring moiety contains an acid and/or hydroxy group and has a net acidity or neutrality and the particulates being negatively-charged or chargeable when the anchoring moiety has a basic group and has a net basicity, wherein the dispersion exhibits a change in sign from negative to positive and an increase in magnitude of a rheological property (viscosity at low shear and/or complex modulus at low amplitude oscillatory shear), on increasing the temperature from below to above the thermal transition temperature.
Abstract:
The invention provides a dispersant for an aqueous dispersion of negatively charged or chargeable solid particulates which comprises a compound having an anchoring moiety linked to a polymeric hydrophilic moiety, the anchoring moiety containing at least one basic group and having an overall basicity and the polymeric moiety having a lower affinity for the particulate surface than the anchoring moiety. The invention also provides a coating composition containing the dispersant, an inkjet recording element containing the dispersant and methods of coating or reducing viscosity using the dispersant.
Abstract:
An ink jet printing method, comprising the steps of: A) providing an ink jet printer that is responsive to digital data signals; B) loading the printer with ink jet recording elements; C) loading the printer with an ink jet ink composition comprising from about 0.5% to about 30% by weight of a pigment, a carrier and a dispersant, the dispersant comprising an anionic derivative of an ethoxylated alkylphenol-formaldehyde resin, the ratio of dispersant:pigment being from about 0.1:1 to about 5:1; and D) printing on the ink jet recording element using the ink jet ink in response to the digital data signals.
Abstract:
Optionally fluorine-substituted alkyl or alkenyl poly(ethylene oxides) the compounds of the general formula in which R is an alkyl group with 10-20 carbon atoms, an alkenyl group with 10-20 carbon atoms or a fluoroalkyl or fluoroalkenyl group with f carbon atoms that each bear at least one fluorine atom and g carbon atoms that bear only hydrogen atoms, in which 1.5 f+g=10-20 and g may optionally be zero. R′ is an alkyl group with 1 to 4 carbon atoms, L is a linking group, a linking atom or a chemical bond, and p is at least 2, q is at least 2 and p+q=from 4 to 100, may be prepared by reacting maleic anhydride with a poly(ethylene glycol) alkyl. ether and reacting the resultant intermediate product with a compound of the formula RL′H in which L′ is a linking group or linking atom. Compounds of the formula (1) may also be prepared by reacting RL-substituted succinic anhydrides with a alkyl end-capped polyethylene glycol. The compounds of the formula (1) exhibit good solubility and surface activity and may be used as antistats, particularly in gelatin media, optionally in conjunction with lithium triflate or the like, in photographic coatings.
Abstract:
A hydrophobically capped oligomeric acrylamide or pyrrolidone is employed as a dispersant for hydrophobic materials in an aqueous medium containing a hydrophilic colloid, e.g. gelatin. The hydrophobic materials include photographic addenda such as color couplers or solid particle dyes. Preferred dispersants have the general formula R—L—T (1) or in which R, R1 and R2 are each independently selected from aliphatic hydrocarbyl, aryl-(aliphatic hydrocarbyl) and (aliphatic hydrocarbyl)-aryl groups, L is a sulphur atom or a linking group that contains a sulphur atom attached to the T group, and T is a hydrophilic oligomeric group obtained by the oligomerisation of one or more vinyl monomers having an amido function.
Abstract:
A water-soluble or water-dispersible, non-ionic surface active compound has the formulaZNHQNHZ (I)whereineach Z independently is a polysaccharide group linked to the remainder of the molecule through one of its ketone groups; and,Q together with the two NH groups to which it is attached represents the atoms necessary to complete a polyalkyleneamine unit wherein at least one of the amine nitrogen atoms has a hydrophobic, substituted or unsubstituted hydrocarbon group linked thereto. Such surfactants can be used in hydrophilic colloid compositions in the manufacture of photographic materials.
Abstract:
A water-soluble or water-dispersible, non-ionic surface active compound is provided having the formula ##STR1## wherein each Y independently is a hydrophilic polyhydroxyalkyl group;each X independently is ##STR2## each R independently is a hydrophobic substituted or unsubstituted alkyl group or a hydrophobic substituted or unsubstituted aryl group;each n independently is an integer from 2 to 6; and,each m is an integer from 2 to 4.Such surfactants can be used in hydrophilic colloid compositions in the manufacture of photographic materials.
Abstract:
Water-soluble, non-ionic surface active compounds are provided having the formula ##STR1## wherein R.sup.1 and R.sup.2 are each independently hydrogen or an alkyl group having from 1 to 4 carbon atoms;X is a hydrophobic substituted or unsubstituted arylene group or a hydrophobic substituted or unsubstituted alkylene group;Y.sup.1 and Y.sup.2 are each independently a chemical bond, --CO-- or --(CH.sub.2).sub.m NR.sup.3 CO--;m is an integer from 1 to 6;R.sup.3 is as defined for R.sup.1 and R.sup.2 ; and,Z.sup.1 and Z.sup.2 are each independently a hydrophilic polyhydroxyalkyl group. The compounds are particularly useful as coating aids for the coating of hydrophilic colloid layers in the preparation of photographic materials.
Abstract:
The invention provides a coating composition containing boehmite particles and a dispersant which comprises a compound having an anchoring moiety linked to a polymeric hydrophilic moiety, the anchoring moiety containing at least one acid and/or hydroxy group and having overall acidity or neutrality and the polymeric moiety having a lower affinity for a boehmite surface than the anchoring moiety. The anchoring moiety preferably contains at least two acid groups, preferably carboxylic acid groups, attached either in a [1,1], [1,2] or [1,3] relationship and is linked to the polymeric moiety, which is preferably derived from acrylamide or methacrylamide monomer units, preferably by a sulfur atom. The dispersant can reduce the viscosity of the boehmite dispersion and the tendency of the boehmite dispersion to increase in viscosity and/or form a gel or a yield stress material following periods of high shear stress.
Abstract:
Pigments for inkjet inks are controllably functionalised to improve water-dispersibility, ozone resistance, etc., by irradiation of the pigment particle with high energy radiation, such as gamma radiation in air or by plasma activation, to form a stable functionalisable intermediate pigment particle, then activating the stable functionalisable intermediate, e.g. by heating, in the presence of a functionalising precursor (e.g. a polymer or polymerisable monomer) to form a modified pigment particle having one or more functionalising group grafted onto the pigment particle.