WO2008151245A1

WO2008151245A1 - Dispersions for plastic films

Info

Publication number: WO2008151245A1
Application number: PCT/US2008/065798
Authority: WO
Inventors: George Robertson
Original assignee: Sun Chemical Corp
Current assignee: Sun Chemical Corp
Priority date: 2007-06-04
Filing date: 2008-06-04
Publication date: 2008-12-11
Anticipated expiration: 2009-12-04

Abstract

High molecular weight polymers mixed with pigment a pre-dispersion containing an aqueous pigment and a carrier. The pre-dispersion and colored polymer exhibit superior color strength, dispersion level, and transparency/opacity.

Description

DISPERSIONS FOR PLASTIC FILMS

Field of the Invention

This invention relates to the coioring of polymers using pigment pre- dispersions designed to impart superior color strength, dispersion level, and transparency/opacity.

Background of the Invention

Applications using high molecular weight polymers have customarily introduced color via pigmentation using costly and time-consuming dispersion techniques employing extreme shear (such as extrusion) and heat. In contrast, pigment flushing is a iess intensive procedure, and more importantly can provide superior dispersion results leading to better color properties. However high molecular weight polymers, in particular polar polymers, and ionomers, are not good candidates for pigment flushing. Selection of suitable carriers to allow flushing and not produce a deleterious impact on the polymer properties is therefore highly desirable.

Excellent dispersion and film transparency are especially important in the automotive industry where molded plastic parts and laminates are being introduced to replace paint films. These plastics require special mechanical properties which are generally obtained by relying on high molecular weight polar polymers, and ionomer laminates. To achieve color equal to paint films color must be very well dispersed so that chroma and transparency in the polymer match those of the paint films. In some cases new plastic components may closely abut an existing painted part, making a close match essential. Ionomers with their excellent clarity and mechanical strength are ideal candidates to produce these colored parts so developing satisfactory coloring methods these ionomers, is highly desirable. U.S. ϊsmsl No. 6,528,174 is directed to ethylene copolymers with vinyl acetate or with lower alky! acrylates, and ethylene terpoiymers with vinyl acetate and carbon monoxide as film-forming compositions with an olefinic bisoleamide additive.

U.S. 2002/0055006 is directed to colored multilayer thermoplastic sheets for surfacing polymer parts made up of layers of ionomers, ionomer polyethylene or polyamide blends, and polyethylene. The ionomers are derived from copolymers of ethylene and carboxylic acids, in particular various lower alkyl acrylates. The structural polymers include thermoplastic polyolefins, polyesters, sheet molding compounds, acryionitrile butyl styrene, polyvinyl chloride, polystyrene, polyurethane, and polyethylenes. Pigments are introduced by forming a millbase with dispersing resins which may be the same as or closely related to the pigment-incorporating material and later dispersing the pigment by conventional grinding or milling.

U.S. 2005/0227022 is directed to multilayered laminates made from ionomers and acid polymers contacted with substrates such as polyolefins. One ionomer layer may be pigmented. Only pigmentation by concentrated pellet form is specified. The ionomers include alpha-olefin derived units such as ethylene and alpha, beta-ethylenically unsaturated carboxylic acid derived units. The structural materials include foams, thermoplastics, elastomers, polyolefins, polypropylenes and polyethylenes, plastomers, acrylonitrile-butadiene-styrine terpoiymers, acetal and acrylic polymers, cellulosics, fluoroplastics, polyamides, polycarbonates, polyesters, polystyrenes, and other such materials.

U.S. Patent No. 6,432,598 is directed to nonflushing methods of making particulate yellow toner compositions for electrostatographic image development by predispersing dry Pigment Yeiiow 185 in a thermoplastic polymer such as polyesters, polyamides, pofyolefins, acrylic polymers and copolymers, methacryfic or styrenic or vinyl polymers and copolymers, and polyurethanes and then combining the pre-dispersion with a second thermoplastic polymer. A need exists for pigment dispersions which achieve superior color strength, dispersion level, and transparency/opacity in polymers.

5 Summary of the Invention

Flushed pigment dispersions and techniques to make pigment pre- dispersions which achieve superior color strength, dispersion level, and transparency/opacity in a final product using high molecular weight polar polymers and ionomers suitable for such applications as plastics and ionomeric laminates. 0

An object of the invention is a method for making a pigment pre-dispersion composition for use with an ionomer comprising the steps of:

(a) creating a slurry of a pigment in water;

(b) melting or softening a resin compatible with an ionomer; and 15 (c) mixing the slurry into the melted or softened resin.

Another object of the invention is a pigment pre-dispersion composition for use with an ionomer comprising:

(a) a resin that is compatible with an ionomer; and !0 (b) a pigment having a particle size that is less than about 30 micrometers.

Another object of the invention is a melt blended composition comprising:

(a) an ionomer; '5 (b) a resin that is compatible with the ionomer; and

(c) a pigment having a pigment particle size that is less than or equal to about 25 micrometers.

Another object of the invention is a method for making a pigment pre- 0 dispersion composition for use with a polymer comprising the steps of: a) combining an aqueous pigment with a carrier; and b) optionally melting the carrier if in solid form.

oring a polymer, comprising the steps of: a) mixing an aqueous pigment with a carrier, said carrier being 5 optionally melted if in solid form to produce a pre-dispersion; and b) mixing the pre-dispersion with the polymer.

Another object of the invention is a pre-dispersion having a dispersion level of about 0.1 microns to about 5 microns. [0

Another object of the invention is a colored polymer having a dispersion level of about 0.1 microns to about 5 microns.

These and other objects and advantages of the present invention wili 5 become apparent from the following description and appended claims.

Detailed Description of the Invention

The process of this invention makes use of flushing technology to achieve ,0 superior color strength, dispersion level, and transparency/opacity of a pigment in a high molecular weight organic polymer. In general, the process of this invention provides excellent dispersion levels and film transparency which current dispersion processes cannot achieve. The process is particularly effective for coloring molded plastics and laminates. 5

The process used for making a dispersed pigment composition comprises first obtaining a pigment in an aqueous environment, then combining the pigment in the aqueous environment with a carrier to form a pre-dispersion; and finally removing the water from the pre-dispersion to obtain a dispersed pigment

0 composition. The dispersed pigment composition is then mixed with a polymer. ⁵rwpr§ment may be in an aqueous state, such as a presscake or slurry or dispersion, or water or other liquid added to form an aqueous state. The pigment may added before or after the carrier, but preferably after especially if the carrier is being melted before the pigment is added. The pigment may be added in one portion or in several portions. The process may be performed at almost any temperature, but a temperature range of about 50⁰C to about 13O⁰C is preferred, and a range of about 85°C to about 95⁰C is especially preferred. The amount of pigment may vary from about 0.1 weight percent to about 60 weight percent, based on the total aqueous pigment and carrier in the pre-dispersion, preferably the amount of pigment is from about 20 weight percent to about 50 weight percent. The amount of carrier may vary from about 0.1 weight percent to about 90 weight percent, based on the total aqueous pigment and carrier in the pre- dispersion, preferably the amount of carrier is from about 50 weight percent to about 80 weight percent.

The pigment dispersion process is preferably a flushing process, where a pigment presscake (or any form of pigment combined with water, such as aqueous pigment slurry) is placed in an appropriate receptacle such as a flusher and the carrier is added in one or more portions. The amount of water present is determined by the amount of water in the presscake or otherwise associated with the pigment. More water can be added if desired.

In the flushing process a pigment in a water wetted form (such as a presscake or slurry) is transferred into the carrier and the associated water is removed, resulting in the replacement of the water by the chosen carrier. The flushing carrier may be in solution in a solvent or may be a material that is liquid or softened at the flushing temperature. Flushing provides good dispersion because the pigment does not go through drying, powdering, and redispersion but goes directly from aqueous phase into the carrier, (see, for example, Pigment Handbook Vol. Ill T. Pattoπ, ed.), 447- New York, John Wiley & Sons, 1973; Printing Ink Manual 3rd ed. (Bisset, Goodacre, Idle, Leach, & Williams, eds) 313, London, Northwood Publications, 1979). Theτ;arπer may be in solution in an appropriate solvent or may dispersed in a material, as long as the solvent or the material are liquid or softened at the flushing temperature. Alternatively the carrier itself may be liquid at the flushing temperature and suitable for addition in pure form. Solvent and carriers known in the art may be employed.

The resulting "pre-dispersion" of aqueous pigment and carrier is mixed by conventional means to generate mechanical shear, i.e. stirring, agitation, milling. Various types of mixers may be used, for example a sigma blade mixer, double arm mixer, or extruder, cowles dissolver, a single blade mixer, a banbury mill, a gaullin homogenizer and the like as well as combinations thereof Water separates and can be poured off. Conventional wetting agents may be added if necessary. The process may be repeated twice or many times if desired. As the water comes off and is decanted, the pigment particles become surrounded by carrier and are thus transferred to the carrier.

After the water has been decanted, the small amounts of water that remain may be removed by other means such as evaporation. The procedures of removing water by decantation and further by evaporation may be used to control and improve the pigment dispersion. Water evaporation can be used to control temperature and thus viscosity for a dispersion period which may be extended by adding more water. A further period of dispersion by shear may be used, with external heating or cooling of the machine jacket used to control the temperature. Temperature control and shear can be used to obtain the best dispersion properties. A continuous flush process as detailed in US 2005/0092203 may be used if desired.

When the pre-dispersion, of aqueous pigment and carrier, has reached the desired fevel of viscosity and pigment dispersion, all remaining water may be removed. The level of viscosity achievable is determined by power usage of the motor horse power. The desired level of dispersion in the pre-dispersion may be

examination of a thin film. The preferred range of viscosity and dispersion depends on the application for the structural polymer which the pigment pre-dlspersion will be used to color. For example, a preferred range of dispersion for automotive parts, films, and laminates is from about 0.1 micron to about 5 microns; a preferred range of dispersion is less than 1 micron. A dispersion range of about 0.8 micron to about 0.3 micron is most preferred. A wide range of viscosities may be employed.

If desired a dry pigment can be used in this process. Not all pigments are available in presscake form. However this technique can also be applied to conventional organic pigments which are more conveniently utilized dry even when presscake is available.

If pigments are not in presscake form, for example inorganic pigments produced by a high-temperature drying process, such as carbon black, iron oxide, and special mixed metal oxides, the process can still be used. The dry pigments may be slurried in water, preferably with the aid of a surfactant/dispersant in preparation for the flushing process, such as for example an ionic surfactant. It is preferred to keep the amount of dispersant to a minimum. Preferred ratios are not critical, but are typically are as follows: pigmentwateπsurfactant about 10:98:2 to about 50:45:5 and preferably about 20-30:75-65:2-5.

When the pigment is transferred to the polymer carrier following making the slurry of a dry pigment, any previous added surfactant should be deactivated. One means for deactivating is converting the surfactant's water solubilizing group to a much less water soluble form causing the surfactant to come out of the aqueous solution. Convenient approaches involve using surfactants with a water soluble group such as sulfonic, sulfate, or carboxylic In their acid or alkali metal salt forms.. These can be reduced in solubility by adjusting the pH or neutralizing the acid group. Typical surfactants include for example ionic surfactants, fatty acid salts such as sodium oleate, potassium oleate, ammonium oleate or similar S&rre 'OT 'essW'Εfll fatty acid, or similar salts of rosin acid (mixture of naturally occurring acids including abietic acid) and the like and combinations thereof.

For example, a dry carbon black pigment can be dispersed in water using water soluble sodium oleate salt. The dispersed black is then added to the flusher and the pH adjusted to below 6, then the pigment flushes into the carrier and water is decanted. The slurry resulting can be added as presscake to attain the correct pigment content of the carrier.

The pigment pre-dispersion made by the above general process is particularly useful for coloring structural polymers and ionomers and described below. The polymers are also useful as carriers with suitable characteristics in relation to the base structural polymers and ionomers as described below.

The pre-dispersion is added to the material to be pigmented by known techniques, for example by extrusion in single or double screw extruders or double arm mixers such as a Banbury mixer or other known equipment and the like, or combinations thereof. The pigmented material may then be used to make products as desired. The pre-dispersions are especially suitable for pigmenting polymers and ionomers used to make molded plastics, backfill, films, and laminates and other articles of manufacture.

Examples of structural polymers are foams, rubbers, plastomers, thermoplastics, elastomers, for example polyolefins, polyesters, sheet molding compounds, acrylonitrile butyl styrene, polyvinyl chloride, polystyrenes, polyurethanes, polyethylenes, polypropylenes acetal and acrylic polymers, cellulosics, fluoroplastics, polyamides, polycarbonates, and the like.

Ionomers are copolymers a certain percentage of whose repeating units are ionic. Examples of ionomers which are useful in forming films or laminates include alpha-olefin-derived units, and alpha_rbeta-ethylenically unsaturated s wi sui a e ions suc as me a ions wnicn are mon , i, tri valent, such as sodium, zinc, calcium and the like.

Salts with these ions are typically formed with the acid group of the carboxyiic acid. Specific ionomers include copolymers of ethylenic monomers and acrylic acid or its analogues. Ionomers are salts of the acid group in the carboxyiic acid (preferably acrylic acid or analogue such as lower alkyl acrylic acid). The acid may be present as free acid groups or converted to salts resulting in ionomer products. These and similar structural polymers and ionomers are well known in the art.

These compounds can be commercially obtained or can be synthesized by well known processes. Also, these compounds can be chemically modified by well known process in order to provide versions having desired characteristics in terms of compatibility as defined below.

The selection of compatible carriers into which pigment is flushed provides optimum properties for plastic components. Carriers can be any polar polymer or ionomer having a molecular weight that is less than the molecular weight of the polar polymer or ionomer being used for the structural application (such as the plastic item, backfill, film or laminate). Thus the carrier into which pigments are flushed are selected to be compatible with the structural polymer or ionomer to be used in the contemplated application, for example by selecting a carrier which is the same molecular entity as the structural polymer or ionomer for the given application, but of lower molecular weight.

Compatibility with regard to mixtures of polar compounds is well known.

Polar polymers as those containing 10% molar of such polar groups as carboxyiic acid, carboxyiic metal salts, carboxyiic acid esters or amides, ethers or halogens and the like or combinations thereof. These may be copolymerized with non polar components which are predominantly straight or branched aliphatic chains such afSMgmyιerø,^o"prøβyfene, butyleπes or higher analogs and the like or combinations thereof.

For compatibility the level the polar molar % should be between 5% and 100%. It is preferred that the level poiar units are simitar in both the flush vehicle and fabricating polymer, In particular using as a carrier the same or a closely related molecular entity as the structural polymer which is of lower molecular weight (for example the same structure but with fewer backbone units) will provide compatibility.

Compatibility between the structural polymer for coloring and the carrier polymer for the pigment pre-dispersion may be determined by various other physical and/or chemical means.

Any molecular weight measurement can be used. However, the melt flow index (MFI) is a convenient measure for this purpose. The melt flow index measures ease of flow of a melted thermoplastic polymer. It is used herein as the weight in grams which flows in ten minutes through a capillary of a given diameter and length. MFI is inversely proportional to viscosity, and a high melt flow rate corresponds to a low molecular weight. Lower MFIs require higher power for pre- dispersion, while higher MFIs tend to weaken the physical properties of the resulting film. Here the standard ASTM D1238 test is used at a temperature of 190⁰C and a pressure of 2.16 kg. The preferred MFI for structural polymers and ionomers is from 0.1 to 200. The preferred MFI for carriers is from 10 to 110, preferably from 30 to 90, and more preferably from 40 to 80.

Any of the polymers listed above may be used as carriers in a suitable molecular weight. Preferable carriers are copolymers ethylenic monomers and acrylic acid or its analogs. Ionomers are salts of the acid group in the carboxylic acid (preferably acrylic acid or analogue). The acid may be present as free acid groups or converted to salts resulting in ionomer products. Typical salts include W sσαrtrm, 2iττcτor calcium. The add value of the carrier is preferably a range of about 1to about 100. A preferred acid value is 20.

Specific polymers are Honeywell AC-540, 580, or 5120 and ionomers AClyn 201 , 246, 285, or 295. These compounds are commercially available carriers which have lower MFI Carriers of lower MFI may be controlled by MW, selection of monomer type and ionomer type and content.

The process of this invention may be applied to any conventional organic or inorganic pigments, in crude or conditioned or unfinished form, such as azos, arylides, diarylides, indolines, iso indolines, indolones, iso indolones, azolones, naphthols, toluidines, rubines, lithols perylenes, rhodamines, quinacridones, benzimidazolones, anthraquinones, phthalocyanines, anthrenes, carbazoles, dioxazines, iron oxides, mixed metal oxides, vegetable and carbon blacks, whites, metallic pigments, fluorescent pigments and the like or combinations thereof.

(see The Printing Ink Manual 5th Edition (Leach and Pierce, eds.) Boston, Kluwer

Academic Publishers, 1999). Dyes may also be used. The pigments should be in aqueous environment, such as a presscake or slurry.

The pigment content in the aqueous environment may be almost any amount, but is preferably from about 20% to about 80% of pigment solids in water, more preferably from about 20 to about 50%. For pigments only available in dry form, the pigment may be slurried in water to form a dispersion. A surfactant may be used if the pigment is slurried, which can later be removed by various techniques, such as control of pH or addition of an insolubilizing metal ion. The surfactant may be any known surfactant.

Pigment pre-dispersions of this invention are particularly useful when added to the pofymer by known techniques, such as but not limited to extrusion. The carriers are selected to be compatible as described with the structural polymers or ionomers which will be used to make a final product such as a flrrøejetø^υpra&tf£^υβart or an extrude film. Such parts may be used in automotive fabrication for various colored body parts

Preferably the structural polymer is a polar polymer, in particular a polar

5 polymer with a low melt index and high viscosity, or is an ionomer. Cotoring is facilitated by adding pigment such as to the main polymer to be colored in a predispersed form. For best results, the pigment may be predispersed in a polymer matrix that is of lower molecular weight than the polymer that requires coloring. In addition the pre-dispersion carrier should be compatible with the main 0 polymer. Compatibility is important for maintaining the physical properties and clarity of the colored film. Incompatible carriers give rise to a haze which is unattractive for bright colors.

5 Examples

The practice and advantages of the present invention are disclosed in even greater detail in the following Examples, which are illustrative only and are not intended to limit the invention in any manner whatsoever.

>0

Example 1

5.6 lbs. of an acid copolymer (acid value 20 and a molecular weight of 10,000} was charged to in a mixer (sigma blade) and the temperature raised by passing steam through the jacket. The blades were also activated at 31 rpm.

5 When the temperature reached 95⁰C, 5 lbs. of a 30% solids presscake (1.5 Ib. pigment) of P. R. 177 was then added and the temperature was maintained at 90- 100^σC with continuous agitation. The pigment was adsorbed into the polymer and clean water was decanted after one hour processing. A further 1.6 lbs. of presscake (0.5 Ib. pigment) was added and processing continued for a further one

0 hour period; clean water was again decanted. A final 1.67 lbs. presscake was then added and processed at temperatures up to 95°C and all water decanted. The machine was then closed and vacuum applied to remove all water: „ _Λ . temperarare"TOse to 115°C over a 40 minute period. The material in the mixer was then cooled to -4 ⁰C by addition of solid carbon dioxide. The cold brittle mass is then broken up and discharged from the mixer. The small lumps are then further ground on for example a cryogenic hammer mill to give a coarse powder with a particle size of between 1.5 mm to 500 micron. The particle size range may be controlled further by conventional sieving.

For color evaluation the flush was let down into a rigid PVC (Novablend 5000 from Novatech Plastics) by adding 2.67 gm. of the above 30% flush into 77.3 gm PVC. Dispersion is carried out on a roll mill.

The inventive pre-dispersion and the inventive pigmented polymer were observed in an optical microscope to determine the dispersion level of each. The same was done for the comparisons below. The color of the inventive pigmented polymer including the inventive pre-dispersion was compared to (a) a dispersion of the same pigment as dry color into the same co-polymer at same level and then let down into the rigid PVC and, (b) a dispersion of the same dry color directly into the rigid PVC. The inventive pre-dispersion and the inventive pigmented polymer showed improved dispersion level compared to (a) and (b) above, as well as showing a visually more transparent affect.

Example 2

The process of Example 1 was repeated through the flushing stage but the PR177 presscake was replaced by an equal amount of a PB 15:1. After flushing, but before vacuum, 13 lbs. of de-ionized water was added slowly maintaining the material at >85°C. The material and water was then thoroughly mixed before decanting. The decanted water showed a slight rise in conductivity indicating value of washing in removing water soluble salts. Vacuum, cool down and grinding then proceeded as Example 1. Testing by the same procedure of Example 1 was done versus a dry sample of PB 15:1. The inventive pre- dispersion and the inventive pigmented polymer showed improved transparency and finer dispersion than the comparisons. x mp e

The procedure of Example 1 was repeated but in place of a 30% presscake of PR 177, a 10% slurry of Carbon Black (Monarch 880 from Cabot) was used. (The slurry preparation is given below). After the 15 Ib. of slurry (1.5 fb pigment) was added, the pH was adjusted to 5 by addition of dilute (1N) acetic acid. On addition of the acetic acid, the black slurry flocculated and behaved like a presscake: flushing then occurred and water decanted. The process was then continued as Example 1 with two slurry additions of 5Ib slurry (0.5Ib pigment) in place of presscake, followed by pH adjustment to produce good flushing. After flushing of third slurry was complete, the flush was washed with city water (13tb and then de-ionized water (10Ib). The vacuum, cooling and grinding was then as in Examplei .

Testing was again as in the procedure used in Example 1 versus a dry sample of carbon black (Monarch 880). The inventive pre-dispersion and the inventive pigmented polymer showed improved transparency and finer dispersion than the comparisons.

Black Slurry

O.δparts of a fatty acid mixture (Sylvatal DT-30) was added to 90 parts of water and pH adjusted to 9.5 - 10 with sodium hydroxide. To the alkaline solution, 30 parts of Monarch Black 880 (Cabot Corp) was added with stirring. The mixture was stirred for 30 minutes with the pH maintained at 9.5 - 10.0. A slurry was achieved.

Example 4

The procedure of Example 3 was repeated but the Monarch 880 was replaced by a 25% slurry of Monarch 1300. The Monarch 1300 slurry was made by the same procedure from 1.2 parts of Sylvatat DT-30 on 25 parts Monarch

1300 in 74 parts of water at pH 9.5-10. Addition of the pigment slurry was again in tnrøeistfijjgs WItTf adds of 61b slurry (1.51b pigment) initially followed by two adds of 21b each (0.5 Ib pigment each); same p H adjustments and washing, cooling, and grinding were performed as in Example 1.

5 Testing was again as in the procedure used in Example 1 versus a dry sample of carbon black (Monarch 1300). The inventive pre-dispersion and the inventive pigmented polymer showed improved transparency and finer dispersion than the comparisons. 0

Example 5

The procedure of Example 3 was repeated but the Monarch 880 slurry was replaced by a slurry of the dry powder of PY 110 (frgazin 3RLTN).

L5 Testing was again as in the procedure used in Example 1 versus a dry sample of PY110. The inventive pre-dispersion and the inventive pigmented polymer showed significantly finer dispersion than the comparisons, as well as improved transparency.

:o

Example 6

The procedure of Example 3 was repeated but the Monarch 880 slurry was replaced by red iron oxide - PR 101 (KDT5094 ex RocKwood) slurry. (The slurry preparation is given below). For the flushing process a first add 5Ib was followed 5 by 2 adds of 1.6 Ib each. Washing, cooling and grinding was as in Example 1

Testing was again as in the procedure used in Example 1 versus a dry sample of PR 101, as well as a slurry of PR 101 only including water and no surfactant. The PR101 water only slurry, without the surfactant, did not flush due D to poor water separation and also showed poor dispersion level. iWFnwntive pre-ctispersion (including the slurry with the surfactant) and the inventive pigmented polymer showed improved transparency and finer dispersion than the comparisons.

5 PR 101 Slurry

3 parts of a surfactant (fatty acid mixture (Sylvata! DT-30 by Arizona Chemical)) was added to 67 parts of water and pH adjusted to 9.5 - 10.0 with sodium hydroxide. 30 parts of the PR 101 was then added and mixture stirred for 30 minutes. This mixture was then passed through a media mill (0.5 mm steel shot in 0 an Bger Mill) to achieve a 20 minute residience time. A well dispersed fluid slurry was obtained and used for flushing in the above procedure.

[ 5 In general, the inventive pre-dispersion and the inventive pigmented polymer show improved transparency, opacity, color strength and dispersion levels compared to polymers pigmented with dry pigment or pigment slurry (including onfy water).

'0 It should be understood that the preceding is merely a detailed description of one preferred embodiment or a small number of preferred embodiments of the present invention and that numerous changes to the disclosed embodiment(s) can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. The preceding description, therefore, is not meant to

5 limit the scope of the invention in any respect. Rather, the scope of the invention is to be determined only by the appended issued claims and their equivalents.

Claims

CLAIMSWe claim:

1. A method for making a pigment pre-dispersion composition for use with an ionomer comprising the steps of: (a) creating a slurry of a pigment in water;

(b) melting or softening a resin compatible with an ionomer; and

(c) mixing the slurry into the melted or softened resin.

2. The method of claim 1 , wherein the slurry has a pigment particle size of less than or equal to about 50 micrometers.

3. The method of claims 1 or 2, wherein the pigment particle size in the pigment pre-dispersion is less than about 30 micrometers.

4. The method of any of claims 1 to 3, wherein the pigment pre-dispersion when melted will flow through a U.S. Mesh 400 screen.

5. The method of any of claims 1 to 4, wherein the resin that is compatible with the ionomer has a refractive index within about 0.005 of the refractive index of the ionomer when measured at the same temperature and load as the ionomer.

6. The method of any of claims 1 to 5, wherein the resin that is compatible with the ionomer has a melt flow index that is greater than the ionomer.

7. The method of any of claims 1 to 6, wherein the resin is an acid copolymer, acid terpolymer, ionomer, polyethylene, ethylene vinyl acetate, ethylene methylacrytate, or mixtures thereof.

8. A pigment pre-dispersion composition for use with an ionomer comprising: (a) a resin that is compatible with an ionomer; and

(b) a pigment having a particle size that is less than about 30 micrometers.

9. The pigment pre-dispersion composition of claim 8, wherein the pigment particle size in the pigment pre-clispersion composition is less than about 25 micrometers.

10 The pigment pre-dispersion composition of claims 8 or 9, wherein the pre- dispersion pigment composition when melted will flow through a U.S. Mesh 400 screen. 0

11. The pigment pre-dispersion composition of any of claims 8 to 10, wherein the resin that is compatible with the ionomer has a refractive index within about 0,005 of the refractive index of the ionomer when measured at the same temperature and load as the ionomer. 5

12. The pigment pre-dispersion composition of any of claims 8 to 11 , wherein the resin that is compatible with the ionomer has a melt flow index that is greater than the ionomer.

13. The pigment pre-dispersion composition of any of claims 8 to 12 wherein !0 the resin is an acid copolymer, acid terpolymer, ionomer, polyethylene, ethylene vinyl acetate, ethylene methylacrylate, or mixtures thereof.

14. A melt blended composition comprising:

(a) an ionomer; 5 (b) a resin that is compatible with the ionomer; and

15. The melt blended composition of claim 14, wherein the resin that is

0 compatible with the ionomer has a refractive index within about 0.005 of the refractive index of the ionomer when measured at the same temperature and load as the ionomer. TO. iWfTfeWtHended composition of claims 14 or 15, wherein the resin that is compatible with the ionomer has a melt flow index that is greater than the ionomer.

17. The melt blended composition of any of claims 14 to 16, wherein the resin is an acid copolymer, acid terpotymer, ionomer, polyethylene, ethylene vinyl acetate, ethylene methylacrylate, or mixtures thereof.

18. A film or sheet formed from the melt blended composition of claim 14.

19. A multilayer film or sheet comprising:

(a) a polymer layer; and

(b) a pigmented ionomer layer comprising: (i) an ionomer; (ii) a resin that is compatible with the ionomer; and (iii) a pigment having a pigment particle size that is less than or equal to about 25 micrometers.

20. The multilayer film or sheet of claim 19, wherein the polymer layer and the pigmented ionomer layer are co-extruded.

21. The multilayer film or sheet of claim 19, wherein the polymer layer is a clear ionomer layer.

22. The multilayer film or sheet of any of claims 19 to 21 , further comprising a third polymer layer in direct contact with the pigmented ionomer layer,

23. The multilayer film or sheet of claim 22, wherein the third polymer layer is selected from the group consisting of polypropylene, polypropylene copolymer, polyethylene, polyethylene copolymer, polyamide, polyester, ABS, styrene terpolymer, and polyurethane.

EWL 'Tffle'fMftlfayer film or sheet of any of claims 19 to 23, further comprising a fourth polymer layer in direct contact with the third polymer layer.

25. The multilayer film or sheet of claim 24, wherein the fourth polymer layer is selected from the group consisting of polypropylene, polypropylene copolymer, polyethylene, polyethylene copolymer, polyamide, polyester, ABS, styrene terpolymer, and poiyurethane.

26. The multilayer film or sheet of claim 19, wherein the multilayer film or sheet is thermoformed into a part.

27. The multilayer film or sheet of claim 19, wherein the multilayer film or sheet is thermoformed into a part and then injection molded from behind.

28. A method for making a pigment pre-dispersion composition for use with a polymer comprising the steps of: a) combining an aqueous pigment with a carrier; b) optionally melting the carrier if in solid form; and c) removing the water in the mixture.

29. The method of claim 28 wherein the aqueous pigment is a presscake.

30. The method of claim 28 wherein the aqueous pigment is a slurry.

31. The method of claim 30 further comprising adding an ionic surfactant.

32. The method of claims 30 or 31 further comprising neutralizing the pH of the

slurry with add or base or precipitated by addition of at least one polyvalent ion. TNe-røe o c a m w ere n e neu ra za on s ep occurs e ore or after addition of the carrier.

34. The method of claim 28 wherein the aqueous pigment is added to the carrier.

35. The method of claim 28 wherein the carrier is added to the aqueous pigment presscake.

36. The method of claim 28, wherein the aqueous pigment is mixed with the carrier by means of a high shear mixer selected from the group consisting of a sigma blade, double arm mixer, extruder, cowles dissolver, a single blade mixer, a banbury mill, a gaullin homogenizer and combinations thereof.

37. The method of claim 28, wherein the carrier is compatible with the polymer.

38. The method of claim 37 wherein the carrier is a polar polymer or ionomer having a molecular weight that is less than the molecular weight of the polymer in which the pre-dispersion composition will be used.

39. The method of claim 38 wherein the carrier is a copolymer of acrylic acid with an olefin.

. q Rerøm o c aim w erei carrier is an ionomer se ec e rom e group consisting of acid copolymers, acid terpolymers, ionomers, polyethylenes, ethylene vinyl acetates, ethylene methylacrytates, and mixtures thereof.

41. The method of claim 28 wherein the method is carried out at a temperature

of about 50⁰C to about 13O⁰C.

42. The method of claim 41 wherein the temperature is about 85⁰C to about

95°C.

43. The method of claim 28 wherein the pigment is present in an amount of

about 0.1 weight percent to about 60 weight percent, based on the total weight of

pigment and carrier.

44. The method of claim 28 wherein the carrier is present in an amount of

about 50 weight percent to about 80 weight percent, based on the total weight of

pigment and carrier.

45. A pre-dispersion produced by the method of any of claims 28 to 44, having

a dispersion level of about 0.1 microns to about 5 microns.

46. A method of coloring a polymer, comprising the steps of:

a) mixing an aqueous pigment with a carrier, said carrier being optionally melted if in solid form to produce a pre-dispersion; and b) mixing the pre-dispersion with the polymer.

URr^« iffeweffled of claim 46, wherein said aqueous pigment is a pressca e or

slurry.

5 48. The method of claim 47 further comprising adding an ionic surfactant to the

slurry.

49. The method of claim 48 further comprising neutralizing the pH of the slurry

with acid or base or precipitated by addition of at least one polyvalent ion.

[0

50. The method of claim 49 wherein the neutralization step occurs before or

after addition of the carrier.

51. The method of claim 46 wherein the carrier is compatible with the polymer.

5

52. The method of claim 46 wherein the carrier is a polar polymer or ionomer

having a molecular weight that is less than the molecular weight of the polymer.

53. The method of claim 46 wherein the carrier is a copolymer of acrylic acid

0 with an olefin.

54. The method of claim 46 wherein the carrier is an ionomer selected from the group consisting of acid copolymers, acid terpolymers, ionomers, polyethyienes, ethylene vinyl acetates, ethylene methyl aery lates, and mixtures thereof. 5 _ϋu

Ss. I ne^~τrretrrøα of claim 46 wherein the pre-dispβrsion has a dispersion level of about 0.1 microns to about 5 microns.

56. The method of claim 46 wherein the polymer is selected from the group consisting of polyolefins, polyesters, sheet molding compounds, acrylonitrile butyl styrene, polyvinyl chloride, polystyrenes, polyurethanes, polyethylenes, polypropylenes aceta⁽ and acrylic polymers, celfulosics, fluoroplastics, polyamides, polycarbonates, foams, rubbers, plastomers, thermoplastics, elastomers, and combinations thereof.

57. A colored polymer produced by the method of any of claims 46-56, having a dispersion level of about 0.1 microns to about 5 microns.

58. A colored polymer produced by the method of any of claims 46-56 used in molded plastics, backfill, films, laminates and combinations thereof.