Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Reexamination Certificate
2003-04-29
2004-10-05
Green, Anthony J. (Department: 1755)
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
C106S031750, C106S170420, C106S200300, C106S410000, C106S419000, C106S432000, C106S452000, C106S459000, C106S460000, C106S479000, C106S480000, C106S494000, C106S495000, C106S496000, C106S497000, C106S498000, C106S499000, C428S403000, C428S404000, C428S407000, C524S186000
Reexamination Certificate
active
06800127
ABSTRACT:
SUMMARY
The present invention relates to new pigment preparations and a method of using the pigment preparations to color various substrates like high molecular weight material.
BACKGROUND
Due to unusually good mechanical properties, such as toughness, pliability, elasticity, and mechanical strength, polyamides belong to a class of high performance polymers with significant technical importance.
Polyamides pertain to the polar polymers with a high melting point of generally above 250° C. Only high performance pigments with outstanding heat stability can be used for coloring polyamides in the extrusion process. Since few organic pigments possess the properties needed to color polyamide, the availability of shades is limited. For this reason, large quantities of polyamide fibers are still bath dyed using special dyes like for example the acid dyes.
To increase the color strength and color uniformity organic pigments are typically applied into polyamide substrates by using specific pigment preparations. Such pigment preparations are prepared by incorporating the organic pigment into a polyamide compatible high molecular weight resin for example by a kneader process when a pigment crude is used as a starting material or when using a finished small particle size pigment by simply extrusion of a polymer/pigment blend to a wire followed by granulation. The resulting pigment preparation granules contain up to 50% of an organic pigment and are easily dispersible when applied in nylon.
The above method has the disadvantage that the pigment is exposed to a heat treatment twice: A) during the pigment preparation process and B) during the final application process. Many pigments suffer under such drastic conditions and change the hue and loose on chroma.
Surprisingly, it was found a new method by which pigment preparations for polyamide or other appropriate polar high performance plastics can be obtained without an extrusion step. Thus, avoiding a heat exposure above 100° C. during the pigment preparation process. The new method consists of a simple wet blending of small particle size pigments with specific polyamide fillers. The new pigment preparation is a uniform physical blend of pigment and polyamide filler which can be used effectively for coloring high molecular weight material like inks, coatings and plastics, especially plastics formed or shaped by the extrusion process.
Thus, the present invention relates to a process for the preparation of new pigment preparations by wet blending an ultra fine polyamide powder with small particle size organic pigments and its use as a pigmentary composition. The new pigment preparations have unique properties and can be used for the coloration of a variety of substrates. For example they allow the coloring of polyamide fibers in various shades currently obtained only by the environmentally unfriendly and uneconomic aqueous dyeing processes using an environmentally friendlier melt spinning process.
Many patents describe the dyeing of polyamide materials with dyes, in particular with acid dyes. For example U.S. Pat. No. 3,619,123 describes a process for dyeing synthetic polyamide fibers in the presence of one or more aromatic sulfonic acids to produce uniform dyed fibers. U.S. Pat. No. 4,438,140 describes salts of acid colorants and specified copolymers containing tertiary amino groups for its use in cosmetics. U.S. Pat. No. 6,136,433 describes melt-spinning a nylon fiber from a host polymer formed from a mixture of amide monomers and at least one hindered piperidine compound. A colorant is dispersed throughout the host polymer.
U.S. Pat. No. 4,374,641 describes a polymeric color concentrate for thermoplastic polymeric materials and solution dyeing of a nylon fiber. The color concentrate is prepared from a blend of a water- or organic solvent-dispersible polymer and a soluble dye or pigment. The preferred polymer is a polyamide blend with a polyamide component having improved basic dye affinity, as described in U.S. Pat. No. 3,846,507.
U.S. Pat. No. 4,492,686 claims cosmetic make-up compositions containing one or more colored pigments in a carrier or diluent, wherein the pigment is a salt obtained by reacting a polymer containing primary or secondary amine groups with at least 10% of the stoichiometric amount of an acid dyestuff as free acid or salt.
Japanese Patent No. 60/162,881 describes shaped goods comprising of a polyamide and melamine derivative by immersing the shaped goods in an aqueous solution containing 0.1 to 1.5 wt. % of acetic or formic acid or ammonium sulfate at 40 to 45° C. and adding 0.1 to 1.0 wt. % of an acid dyestuff, elevating the temperature of the dyeing solution to 80 to 100° C. in 30 to 60 minutes and maintaining that temperature for 30 to 60 minutes then washing and drying the goods.
Published PCT patent application WO 00/64953 describes a process for the production of micro-spheres of polymers and polymeric pigments. These products are composed mainly of polymers and copolymers containing specific functional groups to provide them specific properties and a higher affinity to colorants.
U.S. Pat. No. 5,874,091 relates to cosmetic compositions that contain particulate filler that has been combined with at least one melanin pigment.
U.S. Pat. No. 6,146,762 describes a modified porous silica, a process for its manufacture and its use in paints and as a carrier for pigments and dyes. The porous silica pores are partially filled with polyamide resins and can be employed as additives to liquid paints, as carriers for pigments and/or dyes, as anti blocking agents for folded or wound films made of olefin material and in cosmetic, pharmaceutical and/or dermatological compositions. The reference does not contemplate the use of porous polyamide particles.
U.S. Pat. No. 5,231,119 describes high porosity, spherical particles of crystalline olefin polymers that can used for preparation of master batches containing additives and pigments.
U.S. Pat. No. 5,667,580 discloses pigment compositions containing an organic pigment and transparent filler having a mean particle size less than 10 &mgr;m and a narrow particle size distribution; as well as methods of preparing the pigment compositions. The pigment compositions are useful for pigmenting high-molecular-weight organic materials; especially coating compositions, curable ink systems, plastics, as well as for use in laser marking applications. Although such pigment compositions show an excellent dispersibility and can be used as stir-in pigments when applied in paints, their pigment concentration is above 65 percent. Due to the high pigment content such compositions are expensive and need special drying and/or pulverization equipment.
Pigment compositions containing a small particle size porous filler and a pigment, and their use for preparing effect coating compositions which produce thin film finishes exhibiting strong lightness and color flop with a pronounced three dimensional effect are described in U.S. Pat. No. 5,997,627. Such pigment compositions proved to have excellent and valuable properties when applied in paints such as automotive paints. However, due to the high pigment content such compositions show an insufficient dispersibility behavior and cannot be applied directly in a one step application process into nylon fibers.
Copending provisional patent application No. 60/290,767, filed on May 14, 2001 describes pigmentary compositions comprising polyamide particles with an average particle size of below 50 &mgr;m and optionally a dye precipitate. They are useful for coloring high molecular weight material, like coatings, inks and in particular plastics like polyvinyl chloride, polyamide, polyester, polycarbonate and, especially polyamide fibers. Such compositions are highly suited for coloring textile fibers but due to their inferior light stability when compared with organic pigments they are less suited for an example for an outdoor application.
SUMMARY OF THE INVENTION
The present invention relates to pigment preparations comprised of a uniform physical blend of pigment a
Ciba Specialty Chemicals Corporation
Green Anthony J.
Stevenson Tyler A.
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