WO2010105165A1

WO2010105165A1 - Polymer bound organic pigment and substrate composites and process for making

Info

Publication number: WO2010105165A1
Application number: PCT/US2010/027150
Authority: WO
Inventors: Donald C. Henderson; Paul Merchak
Original assignee: Sun Chemical Corporation
Priority date: 2009-03-12
Filing date: 2010-03-12
Publication date: 2010-09-16

Abstract

A colored composite particle comprising inorganic or organic substrate, organic pigment or carbon black, and polymeric material; wherein the substrate has a particle size of from about 0.05 μm to 9 μm, and wherein the polymeric material binds the pigment to the substrate. A process for preparing a colored composite particle comprising: mixing inorganic or organic substrate, organic pigment or carbon black, and polymeric material; and the mixture is mixed and heated.

Description

POLYMER BOUND ORGANIC PIGMENT AND SUBSTRATE COMPOSITES AND PROCESS FOR

MAKING

POLYMER BOUND ORGANIC PIGMENT AND SUBSTRATE COMPOSITES AND PROCESS FOR

MAKING

CROSS REFERENCE TO RELATED APPLICATIONS

[oooi] The present application hereby claims the benefit of the provisional patent application of the same title, Serial No. 61/159487, filed on March 12, 2009, the disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] Organic pigments that are alkali stable tend to be hydrophobic and thus not readily dispersible in alkali cementitious matrices. Surfactants or dispersants may be used to render the surface of a hydrophobic particle such as an organic pigment, hydrophilic and thus more easily dispersible. Surfactants are physisorbed (absorbed through non-bonding forces of attraction) as opposed to chemisorbed (chemically bonded) allowing for dissociation of the surfactant from the pigment particle. The liability of surfactants can lead to increased air entrainment which weakens the compression strength of cementitious matrices. In addition, weakly bound hydrophobic particles in a cementitious matrix can be easily washed away with aqueous weathering.

BRIEF SUMMARY

[0003] The above-noted and other deficiencies may be overcome by providing a colored composite particle comprising inorganic or organic substrate, organic pigment or carbon black, and polymeric material; wherein the substrate has a particle size of from about 0.05 μm to 9 μm, and wherein the polymeric material binds the pigment to the substrate.

[0004] One aspect is a colored composite particle comprising inorganic or organic substrate, organic pigment or carbon black, and polymer; wherein the substrate has a particle size of from about 0.05 μm to 9 μm, and wherein the polymer binds the pigment to the substrate, wherein the composite particle exhibits ozone stability in mortar. [0005] One aspect is a process for preparing a colored composite particle comprising: mixing inorganic or organic substrate, organic pigment or carbon black, and polymeric material; and the mixture is mixed; wherein the substrate has a particle size of from about 0.05 μm to 9 μm.

[0006] These and other objects and advantages shall be made apparent from the accompanying description.

DETAILED DESCRIPTION

[0007] One embodiment is a colored composite particle comprising inorganic or organic substrate, organic pigment or carbon black, and polymer; wherein the substrate has a particle size of from about 0.05 μm to 9 μm, and wherein the polymer binds the pigment to the substrate. The particle may also comprise additives such as UV stabilizers, defoamers, plasticizers, dispersants, pozzolans, or mixtures thereof.

[0008] The colored composite particle protects the pigment from chemical, physical, or weathering degradation. Protection is gained by coating the substrate particle with pigment and binding the two with polymer to create a larger size composite particle. The polymeric system can act to protect the pigment by encapsulating the pigment and the substrate. In one embodiment the particle is not a dispersion.

[0009] The colored composite particle may be dry for use in surface shake application but also may be dispersed in a liquid form that is ready for use for dispensing during production of cementitious materials. It may be dispersed in liquid form with other admixtures that facilitate its use in dispensing. In one embodiment the composite particle comprises essentially no water.

[ooio] Typically hydrophobic pigments are difficult to disperse into cementitious systems. The colored composite particle may allow a hydrophobic pigment to be more easily dispersed into cementitious systems.

[ooii] The particle size of the substrate may range from about 0.05 μm to 9 μm, about 0.05 μm to about 5 μm, about 0.5 μm to 9 μm, or about 0.5 μm to about 5 μm. Particle size of the substrate is the average size of the substrate. Small particle size substrates may allow for the maximization of color strength per mass of composite particle. The substrate may comprise inorganic, organic, or a mixture of materials. Examples of substrates include but are not limited to clay, micronized silica, silica fume, fumed silica, sand, starches, titanium dioxide, zinc oxide, barium sulfate, fly ash, iron oxide, Portland cement, calcium carbonate, aluminum oxide, effect pigments, mica, inorganic pigments, particulated resins, and polymeric particulates. The substrate may be surface treated to change the surface polarity or be untreated.

[ooi2] In one embodiment the substrate is selected from clay, micronized silica, silica fume, fumed silica, sand, and starches.

[ooi3] In one embodiment, the substrate assists in distributing the pigment to produce a strong color strength with less mixing. The substrate may increase the average particle size without a dramatic loss in color strength normally associated with larger pigment particle sizes. A larger particle size may help to sterically trap the particle in the end use application, such as in cement, concrete, grout, mortar as well as other Portland cement containing materials. In one embodiment, the substrate may provide color or light scattering that together with the organic pigment provides a desired color appearance.

[ooi4] In one embodiment the substrate particle has a mass density of about 0.8 to about 3.9 g/cm³. The substrate particle may have a mass density of about 1.5 to about 3.9 g/cm³, about 2 to about 3.9 g/cm³.

[ooi5] Examples of organic pigments include but are not limited to azo pigments, isoindolinone pigments, isoindoline pigments, anthanthrone pigments, thioindigo pigments, thiazineindigo pigments, triarylcarbonium pigments, quinophthalone pigments, anthraquinone pigments, dioxzine pigments, phthalocyanine pigments, quinacridone pigments, quinacridonequinone pigments, indanthrone pigments, perylene pigments, perinone pigments, pyanthrone pigments, diketopyrrolopyrrole pigments, isoviolanthrone pigments, and azomethine pigments. Examples of such pigments are: C.I. Pigment Black 7, C.I. Pigment Yellow 3, C.I. Pigment Yellow 14, C.I. Pigment Yellow 65, C.I. Pigment Yellow 73, C.I. Pigment Yellow 74, C.I. Pigment Yellow 111, C.I. Pigment Yellow 183, CL Pigment Yellow 205, and CL Pigment Yellow 206, CL Pigment Yellow 83, CL Pigment Yellow 174, CL Pigment Yellow 176, CL Pigment Yellow 150, CL Pigment Yellow 151, C.I. Pigment Yellow 154, C.I. Pigment Yellow 139, C.I. Pigment Orange 13, C.I. Pigment Orange 5, C.I. Pigment Orange 36, C.I. Pigment Red 188, C.I. Pigment Red 112, CL Pigment Red 3, CL Pigment Red 170, CL Pigment Red 210, Pigment Red 202, CL Pigment Red 254, CL Pigment Red 209, CL Pigment Red 19, CL Pigment Red 122, CL Pigment Red 124, CL Pigment Maroon 179, CL Pigment Violet 19, CL Pigment Violet 23, Pigment Violet 29, CL Pigment Blue 60, CL Pigment Blue 15:1, CL Pigment Blue 15:2, CL Pigment Blue 15:3, CL Pigment Blue 15:4, CL Pigment Green 7, CL Pigment Green 36. The organic pigment may be used to provide color in a desired hue.

[ooi6] In one embodiment the organic pigment is selected from CL Pigment Black 7, Pigment Red 202, CL Pigment Red 254, Pigment Violet 19, CL Pigment Violet 23, CL Pigment Blue 60, CL Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3, CL Pigment Blue 15:4, CL Pigment Green 7, and CL Pigment Green 36.

[ooi7] In one embodiment the polymer comprises a hydrophilic polymer. Examples of hydrophilic polymers are those with sufficient functionalities to make the composite particles dispersible in water. Examples of the functionalities are polyethylene oxide, polypropylene oxide, cellulosic, and carboxylic modified polymers. In one embodiment, the hydrophilic polymer is selected from cellulosic, and carboxylic modified polymers. In one embodiment the hydrophilic polymer is cross-linked.

[ooi8] In one embodiment the polymer is selected from acrylates, methacrylates, acrylic acid, polyurethanes, polyamides, amino resins, hydrocarbon resins, phenolic resins, polyimides, polyesters, polyamides, polyexpoxides, acrylic esters, vinyl alcohols, vinyl esters, styrenes, vinyl actetates, maleic modified resins, polyethylenes, silicone polymers, epoxies, and polyacrylonitrile. In one embodiment the polymer is selected from acrylates, methacrylates, acrylic acid, polyurethanes, polyamides, amino resins, hydrocarbon resins, phenolic resins, polyimides, polyesters, acrylic esters, vinyl alcohols, vinyl esters, vinyl actetates, maleic modified resins, and polyacrylonitrile. In one embodiment the polymer comprises vinyl acetate. In one embodiment the polymer is selected from acrylates, methacrylates, acrylic acid, and polyurethanes. The polymer may be a copolymer of monomers. In one embodiment the polymer comprises a polyvinyl acetate polyvinyl alcohol copolymer, wherein the polyvinyl alcohol content is greater than 90%.

[0019] In one embodiment the polymer is a thermoplastic. The thermoplastic resin may soften from about 90 ⁰C to about 150 ⁰C, about 90 ⁰C to about 130 ⁰C, or about 90 ⁰C to about 110 ⁰C. In another embodiment the polymer is cross-linked.

[0020] The polymer has several potential purposes. It may bind the organic pigment or carbon black to the substrate. The polymer may create a larger particle that may become sterically trapped in the cementitious matrix. The trapped organic pigment can resist aqueous weathering washout. It may protect the particle from chemical, physical, or weathering attack from the external environment or application matrix. It may to render the organic pigment or carbon black compatible with its intended end use. It may hold an anti-weathering agent in close proximity to the organic pigment or carbon black.

[0021] In one embodiment the polymer acts as a substantial barrier to chemical attack. A substantial barrier to chemical attack will retard a color change to the particle. An example is the color change caused by exposure to ozone. The test in Example 1 is a test that determines whether the polymer may act as a barrier to ozone. In one embodiment the composite particle has a Total Color Difference (ΔE_ab) in CIE 1976 CIElab color space referred to as, CIElab color change (ΔE) of not more than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.5 or 1, when tested for ozone stability in mortar for 1 hour. In one embodiment the composite particle has a CIElab color change (ΔE) of not more than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.5 or 1, when tested for ozone stability in mortar for 4 hours. In one embodiment the composite particle has a CIElab color change (ΔE) of not more than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.5 or 1, when tested for ozone stability in mortar for 10 hours. In one embodiment the composite particle has a CIElab color change (ΔE) of not more than about 10, 9, 8, 7, 6, 5, 4, 3, 2, 1.5 or 1, when tested for ozone stability in mortar for 24 hours. [0022] In one embodiment the composite particle an average particle size of about 0.5 to about 50 μm. The composite particle may have an average particle size of about 0.5 to about 25 μm, or 0.5 to about 10 μm.

[0023] Organic pigments generally have lower mass densities (1.2-1.6 g/cc) than common cementitious materials (2-4 g/cc). Dispersing a low density material in a high density material requires more effort and is more likely to separate after mixing than two materials of equal density. It may be desirable to be able to rapidly and uniformly disperse color into the cementitious matrix for practical building material use. A low density color can concentrate at the concrete surface creating a layer with higher color saturation than the bulk. The use of an embodiment of a composite particle may allow the particles to be dispersed under normal mixing conditions for processing both wet and dry cementitious materials with a uniform color.

[0024] The composite particle may be used in a cement mixture or mortar mixture. In one embodiment the composite particle may be dispersed in water, solvated polyvinyl alcohol, defoamers, efflorescence control agents, dispersants, pozzolans, or mixtures thereof.

[0025] In one embodiment the pigment may be bound to a substrate without the use of solvents. The polymer may be a cross-linkable polymer system, a thermoplastic polymer, or a combination thereof. The composite particle offers color durability and dry application advantages over surfactant or polymeric stabilized dispersions of organic pigments in cementitious materials such as concrete, grout, mortar as well as other Portland cement containing materials. The composite particles may be used for integral or non-integral coloration of cement containing materials. The composite particles may be used in other applications such a gypsum, surface coatings, powder coatings, water- based coatings, paints, plastics, printing inks, cosmetics, and other colored applications.

[0026] In one embodiment the polymer is formed during or after the generation of the composite particle by reactive polymers such as monomers and oligomers that are polymerized by methods known in the industry. One common method of polymerization is through the use of thermal initiators or UV initiators where the proper temperature and duration or UV light source is used to cause free radical or other initiation process .

[0027] Additional coatings of the same or different polymer can be added to aid protection of the pigment or to improve cementitious dispersion. Alternatively, the pigment may be dispersed into the liquid oligomers/monomers or thermoplastic polymer followed by addition of the substrate to blend and form the free flowing powder composite particle. Additional layers of liquid oligomers/monomers or thermoplastic polymer may be added after the initial free flowing powder blending process. Variations of addition rate and order of addition may be used.

[0028] The color composite particles may provide easily dispersible colored particles for cementitious systems that yield uniform color saturations and high color strength per unit preparation (composite particle or pigment). Table A shows the percent relative strength and Ease-of-Dispersion improvement over inorganic pigments: Rockwood Azuri Blue (Cobalt blue) and Solomon (94 Iron Oxide Black). The percent strength was determined by adjusting the amount of composite particle require to obtain the same optical density as the inorganic pigment. The mortar mix consists of white Portland cement mortar mix comprising 29 grams of white Portland cement, 53 grams of fine white play sand and 15 grams of water and was thoroughly mixed on a Speed mixer DAC 150 FVZ prior to the introduction of the composite particle. The Ease-of-Dispersion is quantified by mixing the mortar mix with equal amounts of the pigment or composite particle for 5 second cycles at 1300 rpm on a Speed mixer DAC 150 FVZ. The Ease-of-Dispersion was determined by recording the number of cycles needed to reach a uniformly mixed colored mortar and is shown in Table A.

Table A: Strength and Ease-of-Dispersion in mortar.

[0029] Use of the colored composite particle may use less, or no defoamers/plasticizers to counteract an increase in air entrainment that generally occurs with the addition of surfactant stabilized organic pigments to cementitious materials. Both air entrainment and defoamers/plasticizers generally reduce the compressive strength of cured cementitious materials. Increased air entrainment lowers the mass density of both cured and uncured wet cementitious materials. The mass density is measured by placing 106.88 grams of white sand, 58.46 grams of white Portland cement, 28.66 grams of tap water, and 6 grams of colored composite particle or pigment into a 8 ounce jar. The jar is shaken on a Harbil brand paint mixer for 5 minutes. The resultant mixture is measured for mass density using a commonly available density cup and an analytical balance capable of measuring four significant figures. Table B shows that composite particle, Example 3, leads to a smaller reduction in wet uncured mortar mix density than the same C. I. Pigment Green 7 pigment dispersed with a surfactant. In one embodiment, after the particle has been mixed into wet uncured mortar, the density of the mortar decreases to no less than about 95% (2.111 / 2.200) of the original density. Table B: Densities in Mortar Mix

[0030] Both air entrainment and defoamers/plasicizers generally affect the workability of the uncured wet cementitious mixture. Slump is an industry standard method of quantifying workability. The slumps shown in Table C are considered acceptable in the industry, ASTM C143.

Table C: Slump in Portland Concrete

[0031] The colored composite particle protects the pigment from chemical, physical, or weathering degradation. Protection is gained by coating the substrate particle with pigment and binding the two with polymer to create a larger size composite particle. The polymeric system can act to protect the pigment by encapsulation especially if a multifunction multi-overcoat strategy is used. The data in Example 1 shows greater ozone protection than a surfactant control dispersion using the same C. I. Pigment Violet 23 pigment whose formula is given in Table Ib.

[0032] The colored composite particle may provide high color strength at low composite particle percentages relative to inorganic pigments. High levels of colored materials may detract from concrete's physical strength making low levels desirable. Table D shows the amount of pigment or particle needed to produce a concrete with equal color strength.. Table E: Color Strength Advantage over Prior Art

[0033] Inorganic pigments used in concrete are generally earth tone colors with limited hues. Colored composite particles may use organic pigments, which can cover a much wider range of hues and are generally more chromatic than inorganic pigments (i.e. enhanced color chromaticity and color gamut).

[0034] In one embodiment the colored composite particle may be prepared in a process comprising the steps of mixing inorganic or organic substrate, organic pigment or carbon black, and polymeric material; and the mixture is mixed ; wherein the substrate has a particle size of from about 0.05 μm to 9 μm. During mixing the mixture may become exothermic or heat may be added. A thermal or UV initiator may be added to the mixture, and sufficient thermal or UV energy is provided to initiate polymerization, cross-linking, or both.

[0035] In one embodiment the process is essentially solvent-free. In one embodiment the process comprises essentially no water. A process that does not use a solvent improves safety and reduces the impact on the environment, and the waste stream. Water-born processes require the use of surfactants which can affect air entrainment or degrade other end use properties. In addition, a solvent-free process does not require the removal of solvent thereby reducing energy use and CO₂ emissions. The polymer may be created in situ by polymerization of oligomers, monomers, or both; or by the melting of a thermosetting polymer, thermoplastic polymer, or both; or a combinations of these followed by cooling to a solid state. Polymeric material may be oligomers, monomers, or both, thermosetting polymer, thermoplastic polymer, or both; or any combination thereof. Polymeric material may be polymerizable or cross -linkable. [0036] In one embodiment the polymeric material is not precipitated during the formation of the colored composite particles. The polymer is either created in situ by the chemical reaction of oligomers, monomers, or both; or by the melting of a thermosetting, thermoplastic polymer, or both; or any combination thereof; followed by cooling to a solid state. Since these polymeric films are deposited rather than precipitated the film may be more uniform and therefore more protective toward environmental and chemical weathering.

[0037] In one embodiment the polymeric material may be in the form of a powder. The mixture of the pigment, substrate, and polymeric material may be mixed using industrial mixers such as a kneader or high speed chopping blade.

[0038] In one embodiment the polymeric material may be in the form of a powder. The mixture of the pigment, substrate, and polymeric material may be mixed using industrial mixers such as a kneader, high speed chopping blade, a paddle, cowles blade mixer, or shot mill. Water is added and heated to solvate the polymer. The composite particle may be isolated from the mixture by vacuum drying, thermal evaporative drying, or spray drying.

[0039] In one embodiment the dry process comprises a mixer where one or more free- flowing powders are mixed with a liquid binder. The liquid phase binder is then reacted and/or cooled to result in a pigment bound by the polymer to a substrate, typically an inorganic particle. No solvent is used throughout the process. This solid composite particle may be milled and classified by equipment used in the industry.

[0040] In one embodiment the pigment, substrate, and polymeric material are blended either all at once or in a stepwise fashion to create the composite particles. Blending comprises low shear and/or high shear mixing of the particulate materials and a liquid form of the polymeric binder. The liquid form can be precursors that are reacted in situ (i.e., oligomers and monomers) or by the melting of a thermosetting and/or thermoplastic polymer or combinations of these to create the composite particles. Polymerization may occur in the mixing equipment or in a separate step. Initiation of the polymerization may be by heat, electron beam or any other type of initiation. [0041] While the present disclosure has illustrated by description several embodiments and while the illustrative embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications may readily appear to those skilled in the art.

EXAMPLES

Example 1:

[0042] C.I. Pigment Violet 23 (20%, Sun Chemical 246-0505) was blended on a SpeedMixer DAC 150 FVZ with the composition shown in Table 1 except the thermal initiator was held out. This composition was then milled for three passes over a three roll mill at 20 ⁰C. A thermal initiator, Vazo 52, was added and gently mixed until dissolved to prepare a colored liquid dispersion. In a Speed mixer DAC 150 FVZ, 80 grams of Specialty Minerals Super- Pflex 100 CaCO₃ was mixed at 3000 RPM for 1.5 minutes with 20 grams of the colored dispersion, 63D, to provide a final composition of 4% C.I. Pigment Violet 23. The sample was thermally polymerized at 8O⁰C for two hours to obtain the composite particle.

Table Ia: PV23 Composite Particle

[0043] A control for Example 1 was made: The same C.I. Pigment Violet 23 was made into an aqueous dispersion using the formulation in Table Ib: Table Ib: Surfactant Dispersion Control for Example 1

[0044] Three grams of the Example 1 composite particles were added to a white Portland cement mortar mix comprising 29 grams of white Portland cement, 53 grams of fine white play sand and 15 grams of water and was thoroughly mixed on a Speed mixer DAC 150 FVZ. The control experiment was prepared with 0.48 grams of the surfactant based pigment dispersion in Table 1 added to the aforementioned white Portland cement mortar mix. Thus both of the mortar samples had the same pigment percent. The uncured colored mortar samples were placed in a mold and hand tapped to remove air voids. The colored mortar samples were cured for one week at room temperature in a sealed container to prevent water evaporation. The cured colored mortar samples were placed in a chamber for 1 hour, that continually released 300 mg/hr of ozone into an environmental chamber with 1 cu-ft. capacity. The CIELab color values of the colored mortar samples were measured with an X-Rite 938 handheld 0-45 degree spectrophotometer using Presschek II software and D65/10 illumination. In the aforementioned mortar sample, the composite particle Example 1 had a CIELab coordinate color change of ΔE = 1.5 versus ΔE = 21.6 for the surfactant control sample.

Example 2:

[0045] Vazo 67 (1.5 grams) was dissolved in 98.5 grams of Sartomer CN146 to make liquid composition 2 as shown in Table 2a. A 1:1 ratio of C.I. Pigment Blue 15:1 (Sun Chemical 248-4816) and BASF Kaolin clay were blended together at high speed on a common blender for 2 minutes. The liquid composition 2 was added to the blended powders at 1:4 ratio and blended at high speed for 4 minutes. The composite particle was placed in an oven at 100 ⁰C for 2 hrs to polymerize the oligomers, with a nitrogen blanket to prevent oxygen inhibition. Table 2a: Blue Composite Particles

[0046] Example 2b was prepared by replacing the C. I. Pigment Blue 15:1 with C. I. Pigment Blue 15:3 (Sun Chemical 249-1282).

[0047] For characterization in mortar, a colored Portland cement mortar sample was made with 29 grams of white Portland cement, 53 grams of fine white play sand, 15 grams of water, and 3 grams of either Example 2a, Example 2b, or Rockwood Azuri Cobalt Blue as the control. The sample was thoroughly mixed on a Speed mixer DAC 150 FVZ. The Ease-of-Dispersion measure is shown in Table 2b. The uncured mortar was placed in a mold and hand tapped to remove air voids. The colored mortar samples were cured for one week at room temperature in a sealed container to prevent evaporation. The relative strengths are of the cured mortar samples are shown in table 2b.

Table 2b: Strength and ease of dispersion in mortar.

Example 3:

[0048] Vazo 67 (1.5 grams) was dissolved in 98.5 grams of Sartomer CN146. A 1:1 ratio of C.I. Pigment Green 7 (Sun Chemical 264-7414) and BASF Kaolin clay were blended together at high speed on a common blender for 2 minutes. The liquid 3 in Table 3 was added to the blended powders at 1:4 ratio and blended at high speed for 4 minutes. The composite particle was placed in an oven at 100 ⁰C for 2 hrs to polymerize the oligomers, with a nitrogen blanket to prevent oxygen inhibition.

Table 3: C. I. Pigment Green 7 Composite Particle

[0049] For characterization, 0.9 Ib of composite particle was mixed in a one yard concrete mixer into 30 Ib of Portland cement and 120 Ib aggregate. ASTM C-403 method was used to quantify set time and slump. Set time is a quantification of cure rate which shouldn't change significantly from a color-free control. The acceptable set time of the colored sample is 6.2 hrs versus 5.8 for the uncolored control as per ASTM C-403. Slump is industry measure of concrete flow and shouldn't significantly change from a color-free control. The slump of the colored sample is measured at an acceptable 7 inches versus 5.8 inches for the uncolored control as per ASTM C-403.

Example 4:

[0050] A sample 4 having the formulation of 60% Printex 25 (Carbon black from Degussa), 20% Solomon 94 iron oxide black, and 20% of pre-dissolved liquid of 99.75% Sartomer CN 146 and 0.25% Vazo 67 was mixed in a common blender for 4 minutes. The sample was removed and placed in an oven at 100⁰C for two hours to cure. The Example 4 sample (1 gm) provided the same optical density as 3 grams of iron oxide black (Solomon 94) when mixed and cured as described in Example 1 with 29 grams of white Portland cement, 53 grams of fine white play sand, 15 grams of water. Example 5 Thermoplastic process:

[0051] CL Pigment Green 7 (20 grams, Sun Chemical 264-7414), 20 grams of BASF Kaolin ASP 101, and 10 grams of Honeywell ACLYN 285a (ethylene acrylic acid ionomer, Na) were weighted into a stainless steel blender jar and mixed on a common blender at the lowest speed for two cycles of 30 seconds. The sample and container were placed in 120 ⁰C oven for 30 minutes to melt the polymer. The sample and container were removed from oven and immediately blended at the highest speed for 1 minute. The heating and blending steps were repeated. Example 5 was evaluated in the same procedure in Example 1 by replacing the 3 grams of the composite particle of Example 1 with 0.2 grams of Example 5. Example 3 and a chrome green inorganic pigment obtained from Rockwood were also evaluated at the 0.2 gram level.

[0052] The optical densities were 0.169 for the Rockwood pigment itself, 0.639 for Example 3, and 0.595 for the thermoplastic Example 5. The thermoplastic sample of Example 5 yields an optical density near the thermal crosslinked acrylate in Example 3, which is four times the relative optical density strength of the Rockwood chrome green pigment.

Example 6:

[0053] C.I. Pigment Blue 15:1 (20%, Sun Chemical 248-4816) was blended with the composition shown in Table 6a minus the thermal initiator. This composition was then milled for three passes over a three roll mill. A thermal initiator Vazo 52 was added to this composition and gently mixed until dissolved. In a Speed mixer DAC 150 FVZ, 80 grams of submicron CaCO₃ was mixed at 3000 RPM for 1.5 minutes with 20 grams of liquid color to render a final composition of 4% C.I. Pigment PB 15: 1. The sample was cured at 80 ⁰C for two hours. Table 6a: PB15:1 Example 6 Composite Particle, 1214-63C

[0054] Example 6 and a PB 15: 1 control with the same pigment used in Example 6 were added to 80 grams of melted Goodrich 8813 white PVC compound on a hot (260-270 ⁰F) rotating Reliable 2-roll mill to yield a final composition with a 0.2% PB 15:1 mass percent. The colored PVCs were blended via a standard cut and slashing mixing procedure. After 3 minutes of mixing time, the PVC sample was removed from the mill. A square was cut from the vinyl skin and set aside. The blending was repeated for 3 more intervals of 3 minutes taking a sample each time. The same blending time control vs. the composite particle composite vinyl skins were pressed side by side in a Carver press at 7000 psi, 300 ⁰F, and for 15 seconds for an optical density comparison. Table 6b quantifies the superior color strength development of the composite particle in vinyl.

Table 6b: PVC Cyan Status T Optical Density

Example 7:

[0055] CL Pigment Blue 15:3 (20%, Sun Chemical 249-1282) was blended at 120 ⁰C with the 60% ASP 101 and 20% Equistar LDPE MN 710-20. The sample was cooled to room temperature and blended with 20% Acrylate 1 (Sartomer CN146) and cured at 100 ⁰C for 2 hrs. The optical density of mortar samples at 3.0% colorant of a Solomon Cobalt Blue was used as the standard. The percentage of composite particles was adjusted to obtain an equal optical density to the standard for Example 2b and Example 7. The relative color strengths calculated from the mass require to obtain equal optical density are reported in Table 8.

Table 8: Relative strengths of samples in Example 7

Example 8:

[0056] DuPont 70-06 PVOH was pre-dissolved by adding the PVOH to deionized water and placing the mixture in a 95 ⁰C oven for two hours. The PVOH/water blend was mixed on a Speed mixer DAC 150 FVZ and placed back into the 95 ⁰C oven until completely dissolved. The PVOH/solution was cooled to room temperature where it remained stable provided evaporation was prevented. C.I. Pigment Blue 15:3 (1.67%, Sun Chemical 249-1282), ceramic shot, 0.25% Tamol SN, the predissolved DuPont 70- 06 polyvinyl alcohol, 8.33% PVOH, and 89.75% deionized water were shaken on a Harbil paint shaker. The solution of pigment, PVOH, and dispersant was spray dried to result in ~1 micron composite particles with the dehydrated composition of 16.3% C.I. Pigment Bluel5:3, 2.4% Tamol SN, and 81.3% DuPont 70-06. For characterization in mortar, a colored Portland cement mortar sample was made with 29 grams of white Portland cement, 53 grams of fine white play sand, 15 grams of water, and either 0.11 grams of Pigment Blue 15:3 with 15% on pigment Tamol SN or 0.67 grams of the PVOH/PB15:3 composite beads. The samples were thoroughly mixed on a Speed mixer DAC 150 FVZ until uniform color is obtained. The uncured mortar samples were placed in sealed containers and cured in an oven for 15 hrs at 60 ⁰C. [0057] The cured colored mortar samples were placed in a chamber for 24 hours, that continually released 300 mg/hr of ozone into an environmental chamber with 1 cu-ft. capacity. The optical density values of the colored mortar samples were measured with an X-Rite 938 handheld 0-45 degree spectrophotometer using Presschek II software.

Table 9: Color fading from 24 hr ozone exposure.

[0058] The Tamol SN surfactant control sample showed clear evidence of fading by the drop in optical density from 0.934 to 0.788 while the PVOH sample darkened from 0.845 to 1.085.

[0059] In one embodiment, the colored composite particle comprises organic pigment or carbon black, and polymer; wherein the polymer binds the pigment to the substrate, wherein the composite particle exhibits ozone stability in mortar. In one embodiment the colored composite particle does not comprise a substrate.

[0060] Though many of the embodiments described use the colored composite particle in cementitious systems, colored composite particles may also be used in other colored applications such as inks, paints, coatings, plastic materials, cosmetics, powder coatings, etc.

[0061] Those skilled in the art having the benefit of the teachings of the present invention as hereinabove set forth, can effect numerous modifications thereto. These modifications are to be construed as being encompassed within the scope of the present invention as set forth in the appended claims.

Claims

CLAIMSWhat is claimed is:

1. A colored composite particle comprising inorganic or organic substrate, organic pigment or carbon black, and polymer; wherein the substrate has a particle size of from about 0.05 μm to 9 μm, and wherein the polymer binds the pigment to the substrate, wherein the composite particle exhibits ozone stability in mortar.

2. The composite particle of claim 1, wherein the particle size of the substrate ranges from about 0.5 μm to 5 μm.

3. The composite particle of claim 1, wherein the substrate is selected from clay, micronized silica, silica fume, fumed silica, sand, starches, titanium dioxide, zinc oxide, barium sulfate, fly ash, iron oxide, Portland cement, calcium carbonate, aluminum oxide, effect pigments, mica, inorganic pigments, particulated resins, and polymeric particulates.

4. The composite particle of claim 1, wherein the organic pigment is selected from the group consisting of: azo pigments, isoindolinone pigments, isoindoline pigments, anthanthrone pigments, thioindigo pigments, thiazineindigo pigments, triarylcarbonium pigments, quinophthalone pigments, anthraquinone pigments, dioxzine pigments, phthalocyanine pigments, quinacridone pigments, quinacridonequinone pigments, indanthrone pigments, perylene pigments, perinone pigments, pyanthrone pigments, diketopyrrolopyrrole pigments, isoviolanthrone pigments, and azomethine pigments.

5. The composite particle of claim 1, wherein the polymer is a hydrophilic polymer.

6. The composite particle of claim 1, wherein the polymer is a thermoplastic wherein the thermoplastic softens from about 90 ⁰C to about 150 ⁰C, or the polymer is cross-linked.

7. The composite particle of claim 1, wherein the polymer is selected from the group consisting of: acrylates, methacrylates, acrylic acid, polyamides, amino resins, hydrocarbon resins, phenolic resins, polyimides, polyesters, polyexpoxides, acrylic esters, vinyl alcohols, vinyl esters, styrenes, vinyl actetates, maleic modified resins, and polyacrylonitrile.

8. The composite particle in 7, wherein the polymer comprises a polyvinyl acetate polyvinyl alcohol copolymer, wherein the polyvinyl alcohol content is greater than 90%.

9. The composite particle of claim 1, wherein the composite particle has a mass density of about 0.8 to about 3.9 g/cm³.

10. The composite particle of claim 1, wherein the composite particle has an average particle size of about 0.5 to about 50 μm.

11. The composite particle of claim 1, wherein after the particle has been mixed into wet uncured mortar, the density of the mortar decreases to no less than about 95% of the original density of the mortar.

12. The composite particle of claim 1, wherein the particle has a CIElab color change (ΔE) of not more than of about 5 when tested for ozone stability in mortar for 1 hour.

13. A cement mixture or mortar mixture comprising the particle of claim 1.

14. A cementitious admixture comprising the composite particle in claim 1, wherein the composite particle is dispersed in water, solvated polyvinyl alcohol, defoamers, efflorescence control agents, dispersants, pozzolans, or mixtures thereof.

15. A process for preparing a colored composite particle comprising: mixing inorganic or organic substrate, organic pigment or carbon black, and polymeric material; and the mixture is mixed above the polymeric materials softening point; wherein the substrate has a particle size of from about 0.05 μm to 9 μm.

16. The process of claim 15, wherein a thermal or UV initiator is added to the mixture, and sufficient thermal or UV energy is provided to initiate polymerization, cross-linking, or both.

17. The process of claim 15, wherein the polymeric material is a free flowing powder prior to heating.

18. A process for preparing a colored composite particle comprising: mixing inorganic or organic substrate, organic pigment or carbon black, pigment dispersant, solvated polyvinyl alcohol, and water; the mixture is mixed; and the composite particle is isolated.

19. The process of claim 19, wherein composite particle is isolated from the mixture by vacuum drying, thermal evaporative drying, or spray drying.

20. A colored composite particle comprising organic pigment or carbon black, and polymer; wherein the polymer binds the pigment to the substrate, wherein the composite particle exhibits ozone stability in mortar.