US20160017115A1

US20160017115A1 - Liquid color concentrate for use in particle articles

Info

Publication number: US20160017115A1
Application number: US14/868,774
Authority: US
Inventors: Mike Fatta
Original assignee: Badger Color Concentrates Inc
Current assignee: Badger Color Concentrates Inc
Priority date: 2012-05-10
Filing date: 2015-09-29
Publication date: 2016-01-21
Also published as: US9725572B2; US20130298804A1

Abstract

A liquid color concentration for use in plastic articles comprises a non-orthophthalate plasticizer and at least one of a colorant, a functional additive or a special effect pigment.

Description

RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/645,275, filed May 10, 2012, the entirety of which is hereby incorporated by reference for all purposes.

TECHNICAL FIELD

The present disclosure relates generally to the use of a liquid color concentrate for use in plastic articles to impart a desired visual and/or physical effect, such as a process additive, a UV additive and/or color.

BACKGROUND

Plastic has taken the place of other materials in a variety of industries. In the packaging industry, plastic has replaced glass to minimize breakage, reduce weight, and reduce energy consumed in manufacturing and transport. In other industries, plastic has replaced metal to minimize corrosion, reduce weight, and provide color-in-bulk products.
Attracting consumers to purchase individually-sized or family-sized containers includes branding and trade dress. Among the elements of valuable trade dress is the color of the plastic article. Moreover, such color may need to co-exist with translucency, transparency, or other special effects for the plastic container.

SUMMARY

According to one aspect of the present disclosure, a liquid color concentrate for use in plastic articles is provided. The liquid color concentrate comprises a non-orthophthalate plasticizer and at one of a colorant, a functional additive or a special effect pigment.
Another aspect of the present disclosure can include a liquid color concentrate for use in coloring plastic articles. The liquid color concentrate can comprise an amount of 1,4-bis(2-ethylhexyl) benzenedicarboxylate and at least one of a colorant, a functional additive or a special effect pigment.
Another aspect of the present disclosure can include a liquid color concentrate for use in coloring a polyester article. The liquid color concentrate can comprise an amount of 1,4-bis(2-ethylhexyl) benzenedicarboxylate and at least one of a colorant, a functional additive or a special effect pigment.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present disclosure will become apparent to those skilled in the art to which the present disclosure relates upon reading the following description with reference to the accompanying drawings, in which:

FIG. 1 is an image showing the chemical structure of polyethylene terephthalate;

FIG. 2 is an image showing the chemical structure of poly(ethylene 2,6-naphthalate); and

FIG. 3 is an image showing the chemical structure of 1,4-bis(2-ethylhexyl) benzenedicarobxylate.

DETAILED DESCRIPTION

The present disclosure relates generally to the use of a liquid color concentrate for use in plastic articles to impart a desired visual and/or physical effect, such as a process additive, a UV additive and/or color. One aspect of the present disclosure includes a liquid color concentrate comprising a non-orthophthalate plasticizer and at least one of a colorant, a functional additive or a special effect pigment. Advantageously, the non-orthophthalate plasticizer of the present disclosure is highly compatible with certain polymer resins used to form plastic articles, such as polyester articles (e.g., bottles). Historically, ortho-phthalates have been used as plasticizers for polyvinyl chloride (PVC)-based products, as well as liquid color carriers for PVC and polyethylene terephthalate (PET)-based products. The fact that the liquid color concentrate of the present disclosure does not include raw phthalates, which have been associated with human infertility (e.g., lowered sperm count) is advantageous for reproductive health reasons and, thus, provides the public with a safe alternative to ortho-phthalate with certain polymer resins (e.g., PET).
In one aspect of the present disclosure, the liquid color concentrate includes colorant. The colorant can be any combination of one or more additives, pigments, and/or dyes. The choice of colorant is dependent upon the desired color, the machine process, molding temperature, and the end-use of the plastic article.
The science of color is well known to those skilled in the art. Without undue experimentation, one can use color matching techniques to identify a particular location in spherical color space. For example, one skilled in the art can digitally map color space using specific polymer carriers and colorants as raw material ingredients. Alternatively, one can make small samples (i.e., plaques) for visual review.
Colorants are commercially available from a number of sources well known to those skilled in the art. Commercially available pigments are well known to those skilled in the art and include organic and inorganic colorant chemistries. Additionally, commercially available dyes are well known to those skilled in the art and include all organic chemistries. Commercial sources for pigments and dyes include multinational companies, such as BASF, Bayer, Color-Chem International, Sun Chemical, and Zhuhai Skyhigh Chemicals.
Table 1 lists eight commercially available pigment colorants in a variety of primary and secondary colors.

TABLE 1

Commercial Pigment Colorants

Raw Material
Name	CI Name	Family	COLOR	FDA*

TIOXIDE	PIGMENT	INORGANIC	WHITE	Y
R-FC6 WHITE	WHITE 6
REGAL 660R	PIGMENT	ORGANIC		N
BLACK	BLACK 7
POWDER
MPC CHANNEL	PIGMENT	ORGANIC		Y
BLACK	BLACK 7
HELIOGEN	PIGMENT	ORGANIC	BLUE	Y
BLUE K7090	BLUE 15:3
HELIOGEN	PIGMENT	ORGANIC	BLUE	Y
BLUE K6903	BLUE 15:1
34L2000	PIGMENT	INORGANIC	BLUE	Y
AZURE BLUE	BLUE 28
SICOTAN	PIGMENT	INORGANIC	YELLOW	Y
YELLOW	BROWN 24
K 2001 FG
SICOTAN	PIGMENT	INORGANIC	YELLOW	Y
YELLOW	YELLOW 53
K 1011

*As published by the commercial producer.

Table 2 shows fourteen commercially available dyes.

TABLE 2

Commercial Dye Colorants

Raw Material
Name	CI Name	Family	Color	FDA*

Lambdaplast	Solvent	Anthraquinone	Blue	N
Blue NL	Blue 59
Macrolex	Solvent	Anthraquinone	Blue	N
Blue RR	Blue 97
Granular
Macrolex	Solvent	Anthraquinone	Green	N
Green G	Green 28
Granular
Macrolex	Solvent	Anthraquinone	Green	N
Green 5B	Green 3
Granular
Macrolex	Disperse	Polymethine	Orange	N
Orange R	Orange 47
Granular
Macrolex	Solvent	Perinone	Orange	N
Orange 3G	Orange 60
Granular
Macrolex	Solvent	Perinone	Red	N
Red EG	Red 135
Granular
Macrolex	Solvent	Perinone	Red	N
Red E2G	Red 179
Granular
Thermoplast	Solvent	Anthraquinone	Red	N
Red 454	Red 195
Macrolex Red	Disperse	Anthraquinone	Violet	N
Violet R	Violet 26
Granular
Macrolex Red	Solvent	Anthraquinone	Violet	N
Violet B	Violet 13
Granular
Macrolex	Solvent	Anthraquinone	Violet	N
Violet 3R	Violet 36
Granular
Key Plast	Solvent	Pyrazolone	Yellow	N
Yellow 3G	Yellow 93
Key Plast	Solvent	Quinophthalone	Yellow	N
Yellow AG	Yellow 114

*As published by the commercial producer.

The colorants can be intended for transparent, translucent, and opaque plastic articles, as well as all opacities therebetween as required by end-use application and/or customer preference.
Achievement of a color match of a plaque with a desired color, from the creativity of a designer or a pre-arranged color standard, such as PANTONE color standards from an inventory of commercially available colorants, is relatively straightforward for a skilled color matcher, even if a few iterations are required to satisfy the customer.
The concentration of the colorant(s) in the liquid color concentrate is significant for several reasons, such as the relative cost of the colorant ingredient(s), the need for colorants to be evenly distributed and dispersed throughout the liquid color concentrate, and that the liquid color concentrate have a stable and pourable viscosity, all for consistent and precise addition (letdown) of the liquid color concentrate with the polymer resin during the formation of pre-form bottles or other polyester articles. Letdown ratios can depend upon the concentration of colorant(s) and/or additives in the liquid color concentrate and whether the final molded product or article is intended to be opaque, translucent, or transparent.
The concentration of colorant after letdown into the final molded product or article can range from about 0.05 to about 0.2 weight percent, and preferably from about 0.1 to about 0.5 weight percent.
In another aspect of the present disclosure, the liquid color concentrate can be molded with a polymer resin. Suitable polymer resins can comprise a homopolymer or copolymer containing at least one ester functional group in its main chain. For example, a polymer resin can comprise one or more polyesters. Polyesters can be made in the form of a thermoplastic or a thermoset.
Suitable polyesters can have an average molecular weight ranging from about 100 to about 65000, and preferably from about 150 to about 8000, and most preferably about 192 (i.e., a PET monomer).
The polymer resin can have a glass transition temperature ranging from about −15° C. to about 100° C. and preferably from about 10° C. to about 80° C., and most preferably about 76° C. (i.e., the glass transition temperature PET).
Non-limiting examples of polyesters can include PET (FIG. 1), glycol-modified polyethylene terephthalate (PETG) poly(ethylene 2,6-naphthalate) (PEN) (FIG. 2), polytrimethylene terephthalate, polybutylene terephthalate, polyglycolic acid, polylactic acid, polycaprolactone, polyethylene adipate, and polyhydroxyalkanoate.
In one example of the present disclosure, the liquid color concentrate can be molded with PET.
In another example of the present disclosure, the liquid color concentrate can be molded with PETG.
In yet another example of the present disclosure, the liquid color concentrate can be molded with PEN.
In another aspect of the present disclosure, the liquid color concentrate includes a non-orthophthalate plasticizer that is compatible with the polymer resin. The amount of the non-orthophthalate plasticizer present in a plastic article can be measured as a percentage of the non-orthophthalate plasticizer in the finished or final plastic article. The non-orthophthalate plasticizer can include a terephthalate, such as bis(2-ethylhexyl)phthalate or 1,4-bis(2-ethylhexyl) benzenedicarobxylate (referred to as DOTP) (FIG. 3), which is commercially available as EASTMAN 168 (Eastman Chemical Company, Kingsport, Tenn.). In one example, about 0.01% to about 10% of the non-orthophthalate plasticizer can be present in a plastic article (e.g., a bottle).
In some instances, a transparent letdown ration (LDR) can be as low as 0.01 lbs. per 100 lbs (of polymer resin). Thus, for a transparent LDR of 0.01 lbs. per 100 lbs., the corresponding percentage of non-orthophthalate plasticizer present in the plastic article or be indicated as “0.01% in finished part.” Similarly, if a molder was to use a liquid color concentrate (but without any pigments, additives, etc.) at a 5% LDR, the amount of the non-orthophthalate plasticizer present in the plastic article would be indicated as “about 5% in the finished part”. In other words, one skilled in the art would understand the following calculation in this instance: 100 lbs. of plastic resin plus 5 lbs. of a non-orthophthalate plasticizer would yield a total weight of 105 lbs.; therefore, one would understand 0.0476% of the non-orthophthalate plasticizer in final part.
In another aspect, the liquid color concentrate include about 5% to about 100% (e.g., about 8% to about 99.9%) of the non-orthophthalate plasticizer depending, for example, on the colorant type and loading necessary to achieve a desired technical effect. The amount of the non-orthophthalate plasticizer present in the liquid color concentrate can be measured as a percentage of other additives and/or liquids present in the liquid color concentrate. In one example, a white liquid color concentrate can be formulated as follows: about 8% DOTP; about 8% plasticizer (e.g., mineral oil or benzoic acid); about 4% suspension improvement additive; about 1% thixotrope; and about 79% TiO₂. In another example, a transparent liquid color concentrate can be formulated as follows: about 95% DOTP; about 1% Solvent Blue 97; and about 4% thixotrope.
In another aspect of the present disclosure, the liquid color concentrate can additionally or optionally include at least one functional additive to improve processing or performance of one or more constituents of the liquid color concentrate. For example, functional additives for polyester bottles can include anti-oxidants, anti-stats, acetaldehyde scavengers, blowing agents, biocides, exfoliated nanoclays, thickeners, and the like. Generally, minor amounts of such additives provide improvement of performance to the liquid color concentrate during processing with the other ingredients in the polymer resin or in performance of the molded article after manufacturing. One skilled in the art can determine the appropriate concentration of one or more additives without undue experimentation.
Frequently, preparation of a colored plastic article (e.g., a polyester article) does not involve merely color, but also special effect features, such as granite, translucent, pearls, metallics, fluorescents, iridescents, marbles, etc.
Plastic articles exposed to natural sunlight are exposed to ultraviolet rays that can harm the color of the article. Therefore, it is customary (but not required) to include ultraviolet light stabilizers in the liquid color concentrate. The optional additive can add value to the liquid color concentrate as the ultraviolet stabilizer also helps protect the plastic article from adverse effects arising from exposure to ultraviolet rays.
Commercially available stabilizers are well known to those skilled in the art and can include, for example, thermal stabilizers and Tinuvin brand stabilizers (BASF, Florham Park, N.J.), such as Tinuvin 234 stabilizer.
It will be appreciated that known types of mixing and injection molding machinery can be used to make the liquid color concentrate and form plastic articles (e.g., colored polyester articles) in the liquid color concentrate. Mixing equipment used to make the liquid color concentrate can include any suitable equipment already used in manufacture of liquid products. For example, such equipment can include high speed “Cowles” type dispersers, media mills and three-roll mills. Mixing equipment can operate at mixing speeds ranging from about 100 rpm to about 10,000 rpm, and preferably from about 500 to about 8000 rpm. Mixing equipment can operate at temperatures ranging from about 25° C. to about 100° C., and preferably from about 40° C. to about 80° C.
The following example is for the purpose of illustration only and is not intended to limit the scope of the claims, which are appended hereto.

EXAMPLE

Several DOTP-based color concentrates, with letdown ratios up to 5%, were injection molded with polymers (PET, PEN and PETG) with the following results:
Clarity: when measured by a Datacolor SF650 spectrophotometer in transmission mode, the samples all had excellent clarity with no effect versus the clarity of the base polymer resin without the DOTP-based color concentrate.
Viscosity: the viscosity of the DOTP-based color concentrate was at a level where it would be stable and have good shelf life. It showed good dispersion of the pigments and good viscosity for pumping.
Processing: the polymers were injection molded with levels up to, and including, 5% DOTP without screw slippage and with no change to the polymers haze.
The liquid blends were made using a lab Cowles type mixer.
From the above description of the disclosure, those skilled in the art will perceive improvements, changes and modifications. Such improvements, changes, and modifications are within the skill of the art and are intended to be covered by the appended claims.

Claims

1-21. (canceled)

22. A method of making a liquid color concentrate having a stable and pourable viscosity, consisting of:

mixing a colorant,

a non-orthophthalate plasticizer, and

optionally one or more functional additives in a mixing mill or a “Cowles” type mixer at a speed of 100 to 10,000 rpms,

wherein the functional additive is selected from the group consisting anti-oxidants, anti-stats, acetaldehyde scavengers, blowing agents, thickeners, and ultraviolet stabilizers.

23. The method of claim 22, wherein the non-orthophthalate plasticizer terephthalate.

24. The method of claim 23, wherein the terephthalate is 1,4-bis(2-ethylhexyl) benzenedicarboxylate.

25. The method of claim 22, wherein the liquid color concentrate includes about 8% to about 99.9% of non-orthophthalate plasticizer.

26. A method of making a colored plastic article using a liquid color concentrate, comprising:

preparing a liquid color concentrate using a process consisting of:

mixing a colorant,

a non-orthophthalate plasticizer, and

wherein the functional additive is selected from the group consisting anti-oxidants, anti-stats, acetaldehyde scavengers, blowing agents, thickeners, and ultraviolet stabilizers; and

molding the liquid color concentrate with a polymer resin to provide a colored plastic article.

27. The method of claim 26, wherein the non-orthophthalate plasticizer is a terephthalate.

28. The method of claim 27, wherein the terephthalate is 1,4-bis(2-ethylhexyl) benzenedicarboxylate.

29. The method of claim 25, wherein the liquid color concentrate includes about 8% to about 99.9% of non-orthophthalate plasticizer.

30. The method of claim 26, wherein the colored plastic article includes about 0.01% to about 10% of the non-orthopthalate plasticizer.

31. The method of claim 26, wherein the polymer resin is a polyester.

32. The method of claim 31, wherein the polyester is selected from the group consisting of polyethylene terephthalate, glycol-modified polyethylene terepthalate, and polyethylene 2,6-naphthalate