JP2005075875A - Method for producing granular colorant composition for thermoplastic resin and its utilization - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a granular colorant composition which is used for thermoplastic resins, has excellent dispersibility in the thermoplastic resins, does not form dust, and contains a pigment in a high concentration, and to provide a molded product having excellent pigment dispersibility and mechanical physical properties. <P>SOLUTION: This method for producing the granular colorant composition for thermoplastic resins, comprising adding and stirring a mixture solution to the water slurry of an organic pigment or carbon black pigment to phase-transfer the pigment from the water system side to the mixed solution side, is characterized in that the mixed solution comprises an organic solvent and a dispersant dissolved in the organic solvent, wherein the dispersant is selected from (a) an un-modified resin and (b) a hydroxy fatty acid or its ester or alkali metal salt, (a) and (c) an unsaturated carboxylic acid or its anhydride-containing polyolefin resin, and a combination of (a), (b) and (c). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a granular colorant composition for a thermoplastic resin, a granular colorant composition for a thermoplastic resin obtained therefrom, and a molded product.

For coloring thermoplastic resin moldings, powder-like dry color in which a solid dispersant and a pigment are mixed at room temperature, flakes or powders in which the pigment is dispersed at a high concentration in a heat-melted dispersant, etc. The following colorants are used.
The dry color is simply a mixture of a dispersant and a pigment, and dust like the pigment powder is generated. Further, in the colorant obtained by melt-kneading and pulverizing both the dispersant and the pigment, although the generation of dust is reduced, the fine powder part is mixed because of the pulverization process, and the generation of dust cannot be completely suppressed. In addition, the colorant adheres to the molding machine and container used at the time of manufacture, and there is a problem in cleaning properties and work environment at the time of color change.

In particular, since organic pigments and carbon black pigment powders contain fine particles in the pigments themselves, a large amount of dust is generated during measurement, transportation, and mixing, and handling is difficult, so granulation has been required.
There are a number of methods for granulating powder (see, for example, Non-Patent Document 1). However, since other process steps are also required, costs have increased in terms of equipment, time, and physical distribution.

  In recent years, as the demand for higher dispersion of pigments is increasing, as a solution to the above problem, a dispersant dissolved in an organic solvent is added to a water slurry of an organic pigment, and the phase transition of the pigment from the aqueous side to the dispersant side There is a technique for producing a granular pigment that performs a (flushing) treatment (see, for example, Patent Documents 1 and 2). However, it has a dispersant composition aimed at inks and coatings from the beginning to the end, and cannot be applied to colorants for thermoplastic resins in terms of heat resistance, maintenance of physical properties, and compatibility. In addition, when the dispersant was simply changed to polyethylene wax or the like, the treated products were fused together to form a lump and did not form a uniform granule, and the dispersibility in the thermoplastic resin was poor.

  In addition, there is a technique in which an aqueous suspension of an organic pigment treated in an organic medium or an aqueous organic medium is spray-dried to obtain a pigment granule (see, for example, Patent Document 3). However, the pigment treatment process and the granulation drying process are separate processes, which is disadvantageous in terms of cost.

Japanese Patent Laid-Open No. 53-134032 JP-A-63-230776 JP 2001-81349 A “Granulation Manual”, published by Ohmsha, 1975 1-10

  An object of the present invention is to provide a granular colorant that is sufficiently pre-dispersed in the granule in advance so as to suppress dust of the colorant composed of an organic pigment or a carbon black pigment and can be used for coloring a thermoplastic resin as it is. Is to get. In addition, the influence of the dispersant on the thermoplastic resin to be colored is minimized, and the mechanical properties such as tensile strength, flexural modulus, impact strength, etc. are 5 as compared to the value in the case of the colored resin alone. It is to provide a granular colorant that does not give a physical property inhibition of more than 50%.

  The dispersant in the present invention always contains a carboxylic acid. The present inventors have found that pigment dispersion and granulation can be simultaneously performed in an aqueous system due to the presence of carboxylic acid, and the present invention has been completed.

The first aspect of the present invention is a granule for thermoplastic resin obtained by adding a mixed solution to an aqueous slurry of an organic pigment or a carbon black pigment and stirring to cause the pigment to undergo phase transition from the aqueous system side to the mixed solution system side. In the method for producing a colorant composition, the mixed solution is composed of an organic solvent and a dispersant dissolved therein, and the dispersants (a) and (b), (a) and (c), (a ), (B), and (c). A method for producing a granular colorant composition for thermoplastic resins.
(A) Unmodified resin (b) Hydroxy fatty acid, ester or alkali metal salt thereof (c) Polyolefin resin containing unsaturated carboxylic acid or anhydride thereof

  According to a second invention, in the granular colorant composition for thermoplastic resins according to the first invention, the hydroxy fatty acid, ester or alkali metal salt thereof is 12-hydroxystearic acid. It is a manufacturing method.

  The third invention is characterized in that (c) the polyolefin resin containing an unsaturated carboxylic acid or an anhydride thereof is a maleic acid-modified resin or a maleic anhydride-modified resin having an acid value of 1 to 100 mgKOH / g. It is a manufacturing method of the granular coloring agent composition for thermoplastic resins as described in 1 or 2nd invention.

  4th invention is the granular colorant composition for thermoplastic resins obtained using the manufacturing method of the granular colorant composition for thermoplastic resins in any one of 1st-3rd invention.

  5th invention is a molding obtained using the granular colorant composition for thermoplastic resins as described in 4th invention.

  Since the granular colorant composition of the present invention is obtained by the above-described production method, the content of the fine particle portion is small and no dust is generated during use. Therefore, it is excellent in work environment and equipment cleaning at the time of color change. In addition, since the pigment is sufficiently dispersed in the granular colorant composition, good colorability and color developability can be obtained even if it is used as it is for coloring a thermoplastic resin.

  Since the molded product of the present invention is obtained by using the above-mentioned granular colorant composition in which the pigment is well dispersed, the pigment in the granular colorant composition can be dispersed well in the resin to be colored and colored. In addition to the property and color developability, a molded product having good mechanical stability, heat resistance, and color mixing stability when made into a synthetic fiber can be obtained.

Below, the shape bear of implementation of this invention is demonstrated in detail.
Known organic pigments and carbon black pigments can be used in the present invention.
Examples of organic pigments include azo pigments such as monoazo lake, monoazo, disazo, condensed azo, metal complex azo, phthalocyanine, anthraquinone, thioindigo, perinone, perylene, quinacridone, dioxazine, isoindolinone, quinophthalone, isoindolinone, pyrrole, etc. These condensed polycyclic pigments are mentioned.

  The water slurry of an organic pigment or carbon black pigment is a slurry for producing a pigment, and preferably has a pigment solid content of 3 to 15% by weight. These pigments may be obtained by dispersing a once dried product in an aqueous solvent, but an aqueous slurry of a pigment that is preferably not subjected to a drying step is preferable.

  As water used when preparing the water slurry of the pigment, tap water, distilled water, ion-exchanged water, hard water, soft water, etc. can be used, but components that affect the use of the colored resin composition ( It is preferable not to contain coarse particle suspensions, dissolved substances, ions, and the like.

  A water-soluble organic solvent may be added to the water slurry as necessary. Any water-soluble organic solvent can be used as long as the effect of wetting the surface of the pigment exhibiting hydrophobicity can be obtained. Liquids at room temperature are preferred, and alcohols and glycols are particularly suitable.

  The (a) unmodified resin used in the present invention means (c) a known unmodified resin and unmodified wax other than the polyolefin resin containing no unsaturated carboxylic acid or anhydride thereof. For example, polyolefin resin (polyethylene resin, polyethylene resin polymerized with metallocene catalyst, polypropylene resin, copolymer of ethylene and propylene, polyethylene wax, polypropylene wax, etc.), acrylic resin, polyvinyl acetate resin, ethylene ethyl acrylate resin, polyester Based resins and the like.

  In the present invention, the term “resin” means that the weight average molecular weight is 50,000 or more and MFR measurement is possible according to JIS K7210, which is generally called “thermoplastic resin”, and the weight average molecular weight is It shows both of those generally called “wax”, which is generally less than 50000 and incapable of MFR measurement according to JIS K7210.

  Specific examples of (b) hydroxy fatty acid, its ester or alkali metal salt used in the present invention include 12-hydroxystearic acid, methyl 12-hydroxystearate, calcium 12-hydroxystearate, zinc 12-hydroxystearate, 12 -A magnesium hydroxy stearate etc. are mentioned. In particular, 12-hydroxystearic acid is preferable.

  The (c) polyolefin resin containing an unsaturated carboxylic acid or an anhydride thereof used in the present invention refers to a polyolefin resin modified with an unsaturated carboxylic acid or an anhydride thereof. Specifically, maleic acid modified polyethylene, maleic anhydride modified polyethylene, maleic acid modified polyethylene wax, maleic anhydride modified polyethylene wax, maleic acid modified polypropylene, maleic anhydride modified polypropylene, maleic acid modified polypropylene wax, maleic anhydride modified Examples thereof include polypropylene wax. A maleic acid modified resin or a maleic anhydride modified resin is more preferable.

The acid value of (c) is preferably 1 to 100 mgKOH / g. If the acid value is less than 1 mgKOH / g, the colorant granules tend to vary. On the other hand, when the acid value exceeds 100 mgKOH / g, the pigment particles are aggregated due to extreme adsorption or repulsion to the pigment, and it is difficult to obtain an appropriate coloring power. There is a tendency to seriously damage. An acid value of 2 to 50 mg KOH / g is more preferred.
Further, (c) is particularly preferably a maleic acid-modified resin or a maleic anhydride-modified resin having an acid value of 1 to 100 mgKOH / g, more preferably an acid value of 2 to 50 mgKOH / g.

The mixed solution used in the present invention is a dispersing agent comprising any combination of (a) and (b), (a) and (c), or (a), (b) and (c). Is dissolved in an organic solvent.
The content of the dispersant in the mixed solution is preferably in a range corresponding to 0.2 to 1 part by weight with respect to 1 part by weight of the pigment. If the amount is less than 0.2 parts by weight, the pigment dispersibility tends to deteriorate. If the amount exceeds 1 part by weight, various physical properties of the colored resin molded product tend to be lowered. From the viewpoint of pigment dispersibility, 0.3 to 1 part by weight of a dispersant is particularly preferable with respect to 1 part by weight of the pigment.
The proportion of (a) in the dispersant is preferably 30 to 95% by weight, and the proportion of [(b) + (c)] is preferably 5 to 70% by weight.

Organic solvents in the mixed solution include alcohols such as isopropanol and butanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, aromatics such as toluene, xylene and cumene, esters such as ethyl acetate and butyl acetate, and naphthenes A solvent etc. are mentioned. These may be used alone or in combination of two or more.
The mixed solution preferably contains an organic solvent so that the solid content of the dispersant is in the range of 15 to 50% by weight. If the solid content exceeds 50% by weight, the viscosity of the solution increases and the spread when added is poor, and if it is less than 15% by weight, the solvent content increases and it takes time and effort to separate and remove, immediately after producing the granular colorant. Colorant particles may be easily welded together.

The granular colorant composition of the present invention can be produced by the following method.
The pigment water slurry is put into a temperature-adjustable container and stirred with a batch type stirrer such as a high speed mixer or a homomixer while heating.
Thereafter, a mixed solution in which the dispersant component is dissolved in an organic solvent is added, and the pigment in the water slurry undergoes phase transition (flushing) into the mixed solution. The temperature at the time of flushing is preferably equal to or higher than the temperature necessary for dissolving the dispersant in the organic solvent, and is preferably 50 to 80 ° C.
The pigment concentration in the obtained granular colorant composition is preferably 50 to 80% by weight. Therefore, it is preferable to adjust the amount of the dispersant component during the production of the colorant composition.

  After the aqueous phase and the organic solvent phase in the phase transition (flushing) system are separated, the temperature is lowered while stirring, the granular colorant composition is taken out by filtration or decantation, and then the water and solvent are removed in a drying step. After flushing, it is preferable to cool the container or cool water and ice into the container so that the generated granular colorants are not fused to each other and lower the temperature to about 40 ° C. The particle size of the granular colorant composition is preferably about 1.0 to 2 mm.

  The resin to be colored of the granular colorant composition of the present invention is preferably a polyolefin resin. Other resins include polymethylpentene, AS (styrene-acrylonitrile) resin, ABS (acrylonitrile-butadiene-styrene) resin, AES (acrylonitrile-EPDM-styrene) resin, methacrylic resin, acrylic polyamide, EVOH (ethylene vinyl alcohol) resin. , Polycarbonate, polyethylene phthalate, polyethylene naphthalate, polybutylene terephthalate, polyacetal, polyvinyl chloride, polyvinylidene chloride, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyallyl sulfone, fluororesin, liquid crystal polymer, and polystyrene, polyurethane It can be blended in a thermoplastic resin such as a thermoplastic elastomer.

  The molded product of the present invention is obtained by molding the granular colorant composition for thermoplastic resin and the resin to be colored by extrusion molding, injection molding or the like. Examples of types of molded products include two-dimensional molded products such as films, plates, and fibers, and three-dimensional molded products such as bottles.

  In the thermoplastic resin colorant composition and molded product of the present invention, known additives such as an antioxidant can be used as necessary in addition to the above-described constituent components.

  Hereinafter, the present invention will be described in more detail with reference to examples. Hereinafter, “%” means “% by weight” and “part” means “part by weight”.

<Example 1>
1 liter of water slurry of copper phthalocyanine blue ("Lionol Blue FG7351" manufactured by Toyo Ink Co., Ltd.) adjusted to 5% solid content by adding water to an aqueous wet cake equivalent to 20 parts solid content can be heated from the outside In a stainless steel container (heated to 70 ° C.) and stirred with a homodisper (made by Tokushu Kika Kogyo Co., Ltd., 3500 rpm) until uniform.
Subsequently, 10 parts of metallocene polyethylene (“Kernel KJ740” manufactured by Nippon Polychem Co., Ltd.) and 3.3 parts of 12-hydroxystearic acid (manufactured by Ito Oil Co., Ltd.) were dissolved in 39.9 parts of toluene at 70 ° C. (solid) Min 25%) was added and stirred.
At this time, cooling was started after confirming that the pigment dispersed in water had shifted to the mixed solution phase. The stirring time for all steps was about 30 minutes. The product was separated by filtration, dried in an oven at 70 ° C. for 12 hours, and the remaining water and solvent were removed to obtain a granular colorant composition (pigment concentration 60%) having a particle size of 1 to 2 mm. There was no problem of dust generation in this colored composition.

<Example 2>
Granular colorant composition having a particle diameter of 1 to 2 mm except that 12-hydroxystearic acid in Example 1 was changed to methyl 12-hydroxystearate (“CW-FA methyl ester” manufactured by Ito Oil Co., Ltd.). A product (pigment concentration 60%) was obtained. There was no problem of dust generation in this colored composition.

<Example 3>
Except that the metallocene polyethylene in Example 1 was changed to polyethylene wax (“Sunwax 131P” manufactured by Sanyo Chemical Co., Ltd.), the same procedure was followed to obtain a granular colorant composition (pigment concentration 60%) having a particle diameter of 1 to 2 mm. It was. There was no problem of dust generation in this colored composition.

<Example 4>
Granular coloring with a particle diameter of 1 to 2 mm was carried out in the same manner except that 12-hydroxystearic acid in Example 1 was changed to maleic acid-modified polypropylene wax (“Yumex 1001” acid value 25 mg KOH / g, manufactured by Sanyo Chemical Co., Ltd.). An agent composition (pigment concentration 60%) was obtained. There was no problem of dust generation in this colored composition.

<Example 5>
Granules having a particle diameter of 1 to 2 mm except that 12-hydroxystearic acid in Example 1 was changed to polyethylene-acrylic ester-maleic anhydride (“Bondaine HX8210” acid value 15 mg KOH / g manufactured by Sumitomo Chemical Co., Ltd.). A colorant composition (pigment concentration 60%) was obtained. There was no problem of dust generation in this colored composition.

<Example 6>
A granular colorant composition having a particle diameter of 1 to 2 mm (pigment concentration) except that the metallocene polyethylene in Example 1 was changed to an isobutyl methacrylate polymer ("Paralod B-67", manufactured by ROHM AND HASS). 60%). There was no problem of dust generation in this colored composition.

<Example 7>
Except for changing the copper phthalocyanine blue in Example 1 to quinacridone red (“Rionogen Red 5700” manufactured by Toyo Ink Co., Ltd.), the same procedure was followed, and a granular colorant composition having a particle size of 1 to 2 mm (pigment concentration 60) %). There was no problem of dust generation in this colored composition.

<Example 8>
A granular colorant having a particle diameter of 1 to 2 mm without generation of dust, except that 12-hydroxystearic acid in Example 1 was changed to calcium 12-hydroxystearate (“Rick Soap SC” manufactured by Ito Oil Co., Ltd.). A composition (pigment concentration 60%) was obtained. There was no problem of dust generation in this colored composition.

<Example 9>
Add 20 parts of ethanol and 40 parts of water to 20 parts of carbon black (“Mitsubishi Carbon # 44” manufactured by Mitsubishi Chemical Corporation), stir with a homodisper, add 100 parts of water and stir uniformly, and then filter with suction and water. The water was washed with 200 parts, ethanol was removed, and an aqueous wet cake having a solid content of 48% was obtained.
A water slurry of carbon black adjusted to 5% solid content by adding water to the aqueous wet cake equivalent to 20 parts solid content is placed in a 1 liter stainless steel container (heated to 70 ° C.) that can be heated from the outside, The mixture was stirred with a homodisper (made by Tokushu Kika Kogyo Co., Ltd., 3500 rpm) until uniform.
Subsequently, 10 parts of metallocene polyethylene (“Kernel KJ740” manufactured by Nippon Polychem Co., Ltd.) and 3.3 parts of 12-hydroxystearic acid (manufactured by Ito Oil Co., Ltd.) were dissolved in 39.9 parts of toluene at 70 ° C. (solid) Min 25%) was added and stirred.
At this time, cooling was started after confirming that the pigment dispersed in water had shifted to the mixed solution phase. The stirring time for all steps was about 30 minutes. The product was separated by filtration, dried in an oven at 70 ° C. for 12 hours, and the remaining water and solvent were removed to obtain a granular colorant composition (pigment concentration 60%) having a particle size of 1 to 2 mm. There was no problem of dust generation in this colored composition.

<Comparative Example 1>
The same procedure was performed as in Example 1 except that 12-hydroxystearic acid in Example 1 was not used and the metallocene polyethylene (“Kernel KJ740” manufactured by Nippon Polychem Co., Ltd.) was changed to 13.3 parts by weight. A colorant composition (pigment concentration 60%) containing particles of 1 mm or less, having dust generation, and having no uniform shape was obtained.

<Comparative example 2>
The same procedure was performed as in Example 3 except that 12-hydroxystearic acid in Example 3 was not used and only 13.3 parts by weight of polyethylene wax (“Sun Wax 131P” manufactured by Sanyo Chemical Co., Ltd.) was used. A colorant composition (pigment concentration 60%) having a diameter of 1 mm or less and having generated dust and having no uniform shape was obtained.

<Comparative Example 3>
Except for using 12-hydroxystearic acid in Example 6, isobutyl methacrylate polymer ("Paralod B-67", manufactured by ROHM AND HASS) was changed to 13.3 parts by weight. As a result, the product did not disperse in water and became a pasty mass. After drying, it was ground in a mortar for evaluation.

<Comparative example 4>
The same procedure as in Example 1 was carried out except that the metallocene polyethylene in Example 1 was not used and only 13.3 parts by weight of 12-hydroxystearic acid (Ito Oil Co., Ltd.) was used. A granular colorant composition (pigment concentration 60%) having a particle diameter of 1 to 2 mm and no dust generation was obtained.

  The following evaluation tests were conducted on the granular colorant resin compositions of Examples 1 to 9 and Comparative Examples 1 to 4, and the results are shown in Table 1. Evaluation methods and evaluation criteria are shown below.

[Evaluation of fine particle content]
(1) 20 g of the obtained granular colorant composition was placed on a 60-mesh (mesh 250 μm) sieve and subjected to vibration for a certain period of time, and the amount passing through the mesh was measured. If the passage was 1% or less, it was considered acceptable.

[Evaluation of film molding]
A granular colorant composition and polypropylene “F327BV” (manufactured by Sumitomo Mitsui Polyolefin Co., Ltd.) as a resin to be colored are mixed so that the final pigment concentration is 1.5%, and a T-die film molding machine (Toyo Seiki Co., Ltd.). The film was melt-extruded at a molding temperature of 250 ° C. and a screw rotation speed of 50 rpm to obtain a film having a thickness of 50 μm.

(2) Film surface condition (visual observation of presence or absence of film cracks, bumps and smoothness)
5: Smoothness with no film cracks or defects, very good surface condition 4: Good surface condition, no problem in practical use 3: Either with defects or smoothness 2: With film cracks 1: Unable to form film

[Evaluation of pigment dispersibility]
(3) Microscope observation Five visual fields of the T-die film molded product obtained in (2) were observed with a transmission optical microscope 100 times. The maximum pigment particle diameter in each field was ranked in 1 to 5 stages, and the average of 5 fields was obtained. If it is 4 or more, it can be used without any practical problem.
5: 5 μm or less 4: 15 μm or less 3: 25 μm or less 2: 35 μm or less 1: Greater than 35 μm

[Evaluation of injection molded products]
The granular colorant composition and block polypropylene “J707” (manufactured by Sumitomo Mitsui Polyolefin Co., Ltd.) as a resin to be colored are mixed so that the final pigment concentration is 1.5%, and an injection molding machine (“IS75E” TOSHIBA) The following test pieces were molded under the conditions of a molding temperature of 220 ° C and a mold temperature of 40 ° C.

(4) Retention ratio of mechanical properties to colored resin Ten items of tensile strength / elongation (ASTM D638), flexural modulus (ASTM D790), Izod impact strength (ASTM D256), and deflection temperature under load (ASTM D648) were tested. .
The value obtained with the test piece molded only with the resin to be colored was taken as 100%, the retention of the mechanical properties of each test item was determined, and evaluated according to the following criteria.
○: 96% or more in all tests Δ: 90% or more and less than 96% even in 1 test × 1: 90% or less in 1 test

Since the granular colorant composition of the present invention has a small fine particle content, it does not generate dust when used. Therefore, it is excellent in work environment property and equipment cleaning property at the time of color change.
In addition, since the pigment is sufficiently dispersed in the granular colorant composition of the present invention, the pigment in the granular colorant composition is excellent in the colored resin even if it is used as it is for coloring a thermoplastic resin. Since the molded product obtained can be dispersed and has good color strength and color developability as well as mechanical strength, heat resistance, and color mixing stability, a new application can be expected.

Claims (5)

In a method for producing a granular colorant composition for a thermoplastic resin obtained by adding a mixed solution to an aqueous slurry of an organic pigment or carbon black pigment and stirring the mixture to cause a phase transition from the aqueous side to the mixed solution side. The mixed solution comprises an organic solvent and a dispersant dissolved in the organic solvent, and the dispersants (a) and (b), (a) and (c), (a), (b) and (c) shown below. A method for producing a granular colorant composition for a thermoplastic resin, characterized by being selected from the combination of:
(A) Unmodified resin (b) Hydroxy fatty acid, ester or alkali metal salt thereof (c) Polyolefin resin containing unsaturated carboxylic acid or anhydride thereof   (B) Hydroxy fatty acid, its ester or alkali metal salt is 12-hydroxystearic acid, The manufacturing method of the granular coloring agent composition for thermoplastic resins of Claim 1 characterized by the above-mentioned.   (C) The polyolefin resin containing an unsaturated carboxylic acid or an anhydride thereof is a maleic acid-modified resin or a maleic anhydride-modified resin having an acid value of 1 to 100 mgKOH / g. A method for producing a granular colorant composition for thermoplastic resins.   The granular coloring agent composition for thermoplastic resins obtained using the manufacturing method of the granular coloring agent composition for thermoplastic resins in any one of Claims 1-3.   A molded product obtained by using the granular colorant composition for thermoplastic resin according to claim 4.