Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
  • B01J13/02—Making microcapsules or microballoons
  • B01J13/06—Making microcapsules or microballoons by phase separation
  • B01J13/14—Polymerisation; cross-linking
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/24—Crosslinking, e.g. vulcanising, of macromolecules
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D11/00—Inks
  • C09D11/30—Inkjet printing inks
  • C09D11/32—Inkjet printing inks characterised by colouring agents
  • C09D11/324—Inkjet printing inks characterised by colouring agents containing carbon black
  • C09D11/326—Inkjet printing inks characterised by colouring agents containing carbon black characterised by the pigment dispersant
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K23/00—Use of substances as emulsifying, wetting, dispersing, or foam-producing agents
  • C09K23/16—Amines or polyamines
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K23/00—Use of substances as emulsifying, wetting, dispersing, or foam-producing agents
  • C09K23/22—Amides or hydrazides

Definitions

• the particulate solid is preferably modified by being encapsulated within the cross-linked dispersant.
• the modified particulate solid prepared by the process is an encapsulated particulate solid;
• the dispersant is a dispersant having at least one cross-linkable group selected from keto, aldehyde and beta-diketoester groups;
• the compound is a cross-linking agent having at least two cross- linking groups reactive towards said cross-linkable group(s); and
• the reaction comprises cross-linking the dispersant with the cross- linking agent, thereby encapsulating the particulate solid within the cross-linked dispersant.
• the polar liquid medium is optionally a polyol, that is to say, a liquid with two or more hydroxy groups.
• Preferred polyols include glycerol, alpha-omega diols and especially alpha-omega diol ethoxylates.
• the liquid medium comprises water as this tends to result in a particularly stable and fine modified particulate solid.
• the liquid medium comprises from 1 to 100%, more preferably from 10 to 100%, especially from 20 to 90% and more especially from 30 to 80% water by weight.
• Preferred non-polar liquid media include non-halogenated aromatic hydrocarbons
• halogenated aromatic hydrocarbons e.g. chlorobenzene, dichlorobenzene and chlorotoluene
• non-halogenated aliphatic hydrocarbons e.g. linear and branched aliphatic hydrocarbons containing six or more carbon atoms, including those which are fully and partially saturated
• halogenated aliphatic hydrocarbons e.g. dichloromethane, carbon tetrachloride, chloroform, trichloroethane
• natural non-polar liquids e.g. vegetable oil, sunflower oil, linseed oil, terpenes and fatty glycerides
• the dispersants is polymeric, e.g. a polyurethane, polyester or more preferably a polyvinyl dispersant.
• the dispersant may be a combination of different polymer types.
• the dispersant must have at least one, more preferably at least two and especially at least four reactable keto, aldehyde and/or beta-diketoester groups.
• the dispersant having at least two reactable groups tends to show enhanced ability to react compared to those having only one reactable group.
• the reactable groups are preferably cross-linkable groups.
• a preferred method of adding the mono- functional amine to the dispersant having at least one beta-diketoester group is to add sufficient mono-functional amine to a composition comprising the dispersant and water so as to achieve and stabilise a pH of from 7 to 11 and especially preferably from 9 to 10.
• diacetone acrylamide provides reactable keto groups with good reactivity and which do not suffer from the hydrolysis reaction described above.
• the monomer containing at least one keto, aldehyde or beta- diketoester group is incorporated at from 80 to 0.1 mole%, more preferably from 70 to 5 mole% and especially from 70 to 10 mole% based on all the monomers used to make the dispersant.
• the reactable groups can be situated in a hydrophobic segment, in a hydrophilic segment or in both.
• Hydrophilic monomers are those monomers comprising hydrophilic groups which may be ionic or non-ionic groups.
• the ionic groups may be cationic but are preferably anionic. Both cationic and anionic groups may be used to give amphoteric stabilisation.
• Preferred anionic groups are phenoxy, carboxylic acid, sulphonic acid and phosphoric acid groups which may be in the free acid or salt form.
• Preferred salts forms are ammonium, substituted ammonium, quaternary ammonium, sodium, lithium and potassium salts.
• Preferred hydrophobic monomers for making polyesters are esters, acids, acid chlorides, anhydrides, cyclic lactones and alcohols containing C ⁇ -50 -hydrocarbylene more preferably C 4-50 -hydrocarbylene, and especially C e-2 o-hydrocarbylene residues. These can be alkylene, cycloalkylene, arylene, aralkylene, alkarylene. These preferably contain no hydrophilic groups other than those needed for the polyester polymerisation.
• Other preferred hydrophobic monomers include those containing poly C 3-4 -alkyleneoxy (especially polypropyleneoxy), fluorocarbons and siloxanes.
• polyester reaction is itself determined by the amounts and reactions of acids and hydroxy groups a further method of preparing hydrophilic polyesters is to use a non-stoichiometric excess of either the acid or the hydroxy group, or to use stoichiometric equivalence of these groups but not to complete the polyester synthesis to full conversion leaving some hydrophilic groups unreacted.
• Another method for introducing hydrophilic residues is to incorporate polyester monomers containing protected hydrophilic groups which are de-protected after polymerisation.
• Hydrophilic residues can be introduced into polyurethanes by using excess 35 hydroxy groups over isocyanate groups so that the resulting hydrophilic polyurethanes have unreacted hydroxy groups after polymerisation.
• monomers containing protected hydrophilic groups such as a carboxylic acid converted into a protected ester or a hydroxy group converted into a protected esters or silanol can also be used which are later deprotected.
• the dispersant is preferably chosen to suit the liquid medium to be used in the process for preparing the modified particulate solid and optionally also a liquid vehicle to be used in the final intended composition in which the modified particulate solid will be used (e.g. in inks).
• the dispersant preferably has a predominantly hydrophilic character.
• the modified particulate solid is to be used in an oil-based (non-aqueous) paint or ink the dispersant preferably has a predominantly hydrophobic character.
• the acid value (AV) of the dispersant is preferably from 10 to 200, more preferably from 30 to 150 and especially from 60 to 120mg KOH / g of the dispersant.
• the dispersant has a number average molecular weight of from 500 to
• the process preferably comprises filtering a mixture comprising the dispersant, a particulate solid and liquid medium prior to reaction, preferably through a filter having a pore size of less than 10, more preferably less than 5 and especially less than 1 micron. If the compound is present during mechanical treatment of the particulate solid this can result in undesirable pre-reaction of the dispersion before the particle size of the solid has been fully reduced.
• the temperature is preferably not greater than 40°C and especially not greater than 30°C.
• the compound is preferably added to a mixture comprising the particulate solid, dispersant and liquid medium after mechanical treatment to reduce the particle size of the particulate solid.
• Preferred methods of precipitation and flocculation include the addition of metal salts and centrifugation.
• the process of the present invention is capable of being performed at lower temperatures than are suitable for reactable dispersants having alternative reactable groups. This results in reduced levels of flocculation and minimal growth in particle size.
• a modified particulate solid obtainable or obtained by the process of the first aspect of the present invention.
• the modified particulate solid prepared by the process of the present invention is useful in the manufacture of compositions comprising the modified particulate solid and a liquid vehicle.
• such compositions are inks and the particulate solid is a colorant, especially a pigment.
• the liquid vehicle may be identical to or different from the liquid medium used in the process for preparing the modified particulate solid.
• the liquid vehicle is the liquid or liquid mixture present in an "end use" composition such as an ink, a paint or the like. It is often desirable that the liquid vehicle comprises high proportions of water and that further liquids required to make the desired composition (e.g. an ink) are added after the process according to the first aspect of the present invention.
• the liquid vehicle is preferably an organic solvent or water or a mixture thereof.
• the liquid vehicle comprises water, especially when the compositions are intended for use in ink jet printing.
• the liquid vehicle comprises from 50 to 95%, more preferably from 60 to 95% and especially from 60 to 90% water by weight based on the total weight of the composition.
• Transparent plastic films which are 5 suitable for use as overhead projector slides, include for example polyesters (especially polyethylene terephthalate), polycarbonates, polyimides, polystyrenes, polyether sulphones, cellulose diacetate and cellulose triacetate films.
• an ink jet printer cartridge comprising a chamber and a composition according to the third aspect of 10 the present invention wherein said composition is present in the chamber.
• Modified particulate solids obtainable or obtained by the process of the present invention are particularly suitable for use in surface coatings and paints which comprise a modified particulate solid, a liquid vehicle and a binder.
• the particulate solid is preferably a colorant or a filler.
• the paint can be made using the isolated modified 15 particulate solid but it is more preferred to use the composition comprising the modified particulate solid and the liquid medium which results from the process according to the first aspect of the invention without isolating the modified particulate solid.
• a composition comprising a modified particulate colorant or filler obtainable or obtained by a 20 process according to the first aspect of the present invention, a binder and a liquid vehicle.
• the binder is a polymeric material capable of binding the composition on the volatilisation of the liquid medium. Suitable binders include natural and synthetic polymers.
• Preferred binders include poly(meth)acrylates, polystyrenics, polyesters, polyurethanes, alkyds, polysaccharides 25 (e.g. cellulose) and proteins (e.g. casein).
• the binder is present in the composition at more than 100%, more preferably 200%, especially 300% and most
• Example 1 Modified Cyan Pigment Preparation of Dispersant (1)
• a monomer feed composition was prepared by mixing methacrylic acid (25.82 parts), acetoacetoxyethyl methacrylate (128.54 parts), 2-ethylhexylmethacrylate (45.64 35 parts) and isopropanol (100 parts).
• An initiator feed composition was prepared by mixing 2,2'-azobis(2-methylbutyronitrile) (7.25 parts) and isopropanol (50 parts).
• Mill-base d A particulate solid (C.I. Pigment Blue 15:3, 120 parts, ex Clariant) was mixed with Dispersant Solution (1 ) (80 parts) and deionised water (588 parts). The mixture was milled in an Eiger mill for a period of 3 hours. This resulted in a mill-base comprising a particulate solid of Z-average particle size 136nm and a pigment content of 15% by weight. This is Mill-base (1).
• a monomer feed composition was prepared by mixing methacrylic acid (129 parts), methyl methacrylate (75 parts), diacetone acrylamide (190.5 parts), 2- ethylhexylmethacrylate (355.5 parts) and isopropanol (375 parts).
• An initiator feed composition was prepared by mixing 2,2'-azobis(2-methylbutyronitrile) (22.05 parts) and isopropanol (187.5 parts). Isopropanol (187.5 parts) was heated to 80°C in a reactor vessel, continuously stirred and purged with a nitrogen gas atmosphere. The monomer feed and the initiator feed compositions were slowly fed into the reactor vessel whilst stirring the contents, maintaining the temperature at 80°C and maintaining the nitrogen atmosphere.
• Table 1 shows the growth in Z-average particle size from the particle size of the mill-base to the particle size of the corresponding modified particulate solid.
• the particle size growth which results from reacting a dispersant with a medium insoluble diisocyanate compound is significantly larger than that seen with the process of the present invention, especially where the process of the present invention uses a compound which is soluble in the liquid medium.
• Growth in particle size during reaction is particularly undesirable where the modified particulate solid is to be used in an ink jet ink because aggregated particles can block ink jet nozzles and lead to reduced operability and print performance.
• a significant growth in particle size (above for example 25%) may require additional process steps (e.g. micro filtration) to remove aggregated material from the modified particulate solid so that it is more suitable for use in an ink jet ink. This adds technical complexity and is wasteful of the modified product.
• Tegowet 510 is a wetting agent available from Tego.
• Ink jet ink stability testing The Z-average particle size and the viscosity of inks 1 to 6 were measured directly after mixing and following storage for 2 weeks at a temperature of 60°C. Inks 1 to 3, comprising modified particulate solids showed no viscosity increase and less than 5% growth in Z-average particle size following storage. Inks 4 to 6, comprising mill-bases, showed a significant and visible thickening and a growth in Z-averaged particle size of at least 50%. Thus the modified particulate solids resulting from the process of the present invention showed greater stability in ink jet ink compositions than did the conventional mill- bases.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Polymers & Plastics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Medicinal Chemistry (AREA)
• Dispersion Chemistry (AREA)
• Wood Science & Technology (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Ink Jet (AREA)
• Ink Jet Recording Methods And Recording Media Thereof (AREA)
• Processes Of Treating Macromolecular Substances (AREA)

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• 2004
  • 2004-11-24 DE DE602004017055T patent/DE602004017055D1/de not_active Expired - Lifetime
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  • 2004-11-24 JP JP2006541999A patent/JP2007513233A/ja active Pending
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