JPH101572A - Colorant composition for polypropylene - Google Patents

Abstract

(57) [Abstract] [Purpose] There is no mixing of fine chips derived from the colorant into the polypropylene that is colored during molding, and the coloring pigment is easily distributed to the molded article. Provided is a colorant composition having significantly reduced mechanical properties. [Structure] Pigment, isotactic polypropylene having MFR of 10gr / 10min or more and 19: 1 to 1: 1
A composition for coloring polypropylene comprising, as a main carrier component, a polypropylene composition containing a syndiotactic polypropylene in the proportion of [Effect] It is easy to granulate without a powdery swarf in the production process of the colorant, can contain a pigment at a high concentration, and does not reduce the mechanical properties of the molded article when coloring polypropylene and its composite material. In addition, it is possible to provide a granular colorant which does not cause color unevenness or color streaks at the molding process and has good distribution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for molding polypropylene and its composite, in which the pigment compounded as a coloring component is easily distributed to the molded product, and the mechanical properties of the molded product are significantly reduced. The present invention relates to a colorant composition which is easy to handle and does not generate chips in cooling cut of the melt-kneaded product in the production thereof.

[0002] The colorant composition of the present invention can be used in any molding method such as injection, extrusion and hollow.

[0003]

2. Description of the Related Art In recent years, polypropylene has been used in a wide range of applications because the moldability and physical properties have been improved by the improvement of catalysts and polymerization methods, and recycling is easy.

The mainly used polypropylene is a homopolymer of isotactic polypropylene or a copolymer with ethylene or α-olefin, and atactic polypropylene is sometimes used. Particularly, polypropylene having high rigidity and high heat resistance, such as highly crystalline isotactic polypropylene having a stereoregularity and an isotic pentad index exceeding 98%, has been used. These are modified by the addition of other polyolefins, inorganic fillers or rubbers, for example, extruded and melt-kneaded together with ethylene propylene rubber or talc, and are widely used, particularly in the fields of automobiles and home appliances.

[0005] Generally, coloring of plastics is carried out for the purpose of giving a molded article an improvement in various properties such as decorativeness, and a powdery, granular or liquid colorant is used at the stage of injection molding or extrusion molding. The coloring agent is a coloring component obtained by adding a dispersing agent to a pigment or a dye, or a resin is added and simply mixed,
It is obtained by melting and kneading, but its coloring component varies depending on the material and use of the plastic.

[0006] Pigments are exclusively used to color polypropylene, but powdery colorants to which pigments or dispersing aids have been added cause environmental pollution due to handling, and the accuracy of weighing in automatic weighing machines is poor. For this reason, granular colorants, commonly known as masterbatch colors, are often used as one of the easy-to-handle colorants. However, in the production of granular colorants, in particular, when the melt-kneaded extrudate is drawn out and cooled by an extruder, and then cut into granules by a rotary blade type cutting machine, chips due to defective cutting of the granules are generated, and this is automatically measured. In some cases, this could lead to contamination of the machine.

To solve this problem, conventionally, the extrudate was cut immediately after extrusion, the shape of the rotary blade of the cutting machine was devised, or chips were selectively removed.
The masterbatch color concentrates the required pigment concentration when coloring a plastic molded product to a maximum of about 60% by weight, and is kneaded into a suitable carrier resin (also called vehicle resin) with good dispersion. Things. Therefore, at the stage of injection, extrusion, and blow molding, it is used after being diluted according to the concentration ratio.

Problems that arise when diluting the masterbatch color into polypropylene are the distribution of the masterbatch color to the molded article (peptizing property) and the preservation of the physical properties of the colored resin. Polyethylene or polypropylene is usually used as the carrier resin for the masterbatch color for polypropylene, but the pigment concentration of the masterbatch color should be increased in consideration of economy, and the dilution ratio should be increased when used (for the resin to be colored). On the other hand, when the mixing ratio is reduced), the melt viscosity of the masterbatch color becomes high due to the pigment concentration, so that kneading by a molding machine is insufficient, and uneven color and color streaks, which are poor distribution properties, occur.

In such a case, as a measure for eliminating color unevenness and color streaks, the kneading conditions are conventionally reduced by decreasing the pigment concentration of the master batch color and decreasing the dilution ratio, or by changing the screw design of the molding machine or installing a static mixer. And a method of lowering the melting point and viscosity of the carrier resin of the master batch color have been adopted. However, the method of reducing the dilution ratio of the master batch color and increasing the kneading conditions of the molding machine increases the coloring cost due to the increase in the unit cost of the material and the amount of capital investment, and the desired economic efficiency cannot be achieved.
Similarly, if a resin other than polypropylene is used to lower the melting point and viscosity of the carrier resin of the masterbatch color, there is a problem that the properties of the colored resin such as the mechanical strength of the molded article are impaired due to the influence of the resin.

On the other hand, various proposals have been made for improving the distribution property and maintaining the properties of the colored resin by improving the polyolefin which is the carrier resin of the master batch color. For example, JP-A 1-26
No. 1440 discloses that a masterbatch color made of a pigment and a binary or ternary amorphous polyolefin is an olefin resin such as polyethylene or polypropylene, an acrylonitrile styrene butadiene copolymer, or a resin such as polyvinyl chloride. It is disclosed as a technique for improving color unevenness. JP-A-5-202234 discloses, as a vehicle for a masterbatch color, a copolymer of a monomer having an α, β unsaturated double bond and a dibasic acid having an unsaturated double bond or an anhydride thereof. It has been shown that such a material is extremely effective for coloring a polyolefin in which physical properties such as mechanical properties and heat resistance are particularly important. Furthermore, Japanese Patent Publication No. 6-21201 discloses a master batch color composed of a pigment, an ethylene-vinyl acetate copolymer and a polyolefin wax, which is a general-purpose resin such as an olefin resin or a styrene resin even if the pigment content is high. In addition, it is disclosed as a colorant composition having good pigment dispersion and easily distributing at the time of molding even for high processing temperatures such as polyamide and polyacetal, that is, for engineering plastics.

[0011]

The mechanical properties of polypropylene have recently been improved, and its use has been expanded to fields requiring high mechanical properties. Therefore, a colorant that does not impair the original physical properties of the material has been desired. ing. Therefore, the required performance becomes more severe, and the conventional general-purpose colorants are not always satisfied.

In the present invention, an olefin resin different from these carrier resins is used, and it is easily granulated in the process of producing a coloring agent.
Pigment can be contained in high concentration, and when coloring polypropylene and its composite material, it does not reduce the physical properties of colored resin such as tensile strength, flexural strength, flexural modulus, impact strength, etc. It is an object of the present invention to provide a granular colorant having good distribution without causing color unevenness or color streaks in a processing stage.

[0013]

Under these circumstances, the present inventors have conducted intensive studies on improving the dispersibility of the particulate colorant and preventing the deterioration of the properties of the colored resin. When syndiotactic polypropylene is added to isotactic polypropylene as a carrier resin for the coloring agent, the distribution properties are excellent at the time of injection molding, extrusion or coloring molding of hollow, etc., so that color unevenness and color streaks are not generated, and Was found to be hardly impaired. It has also been found that when the pigment and these carrier resins are melt-kneaded, drawn out of a processing machine and cooled and cut, the generation of chips is extremely small.

That is, the present invention relates to a colorant composition comprising a pigment and a carrier resin, polypropylene as a main component, wherein the polypropylene has a weight ratio of isotactic polypropylene to syndiotactic polypropylene of 1%.
The present invention relates to a colorant composition for polypropylene, characterized in that a mixture of 9: 1 to 1: 1 is used. In particular, isotactic polypropylene has a MFR (ASTM D123).
The present invention relates to a granular colorant (master batch color) having a melt flow rate (melt flow rate of 8 L) of 10 gr / 10 min or more and containing 5 to 80% by weight of a pigment.

Further, the present invention can achieve its object better by adding various polyolefins or derivatives thereof as a modifier to the above-mentioned carrier resin as a modifier depending on circumstances and if desired.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The typical embodiment and the best state of the embodiment of the present invention are specifically shown in the following examples. This will be described in detail.

The syndiotactic polypropylene used in the present invention is a polypropylene having a syndiotactic pentad fraction of more than 0.7 discovered by JAEWEN et al., Which is disclosed in JP-A-2-41303 and JP-A-2-4130.
5 is a polypropylene polymerized with the metallocene catalyst disclosed in No. 5. In the present invention, either a homopolymer or a copolymer with ethylene or an α-olefin may be used, and the shape such as a powder or a particle is not limited. The MFR may be 0.1 or more, and those having a wider molecular weight distribution are more effective in increasing the fluidity. The molecular weight is preferably from 3000 to 1,000,000. Examples of such a material include Tiaro (trade name) of Mitsui Toatsu Co., Ltd. It has a softening and melting temperature of about 140 ° C., which is lower than isotactic polypropylene, higher than atactic polypropylene or low density polyethylene (LDPE), and is also used as a carrier resin for granular colorants. HDP
It is almost equivalent to E) or linear low density polyethylene (LLDPE).

Conventionally, when a particulate colorant using a carrier resin other than polypropylene is used for coloring polypropylene or a copolymer thereof, or a polypropylene modified with an inorganic filler or rubber (referred to as a compound), the physical properties of the colored resin deteriorate. If the addition rate is small, color streaks and color unevenness increase,
Conversely, the addition rate was high, and depending on the molding conditions, the carrier resin peeled off on the surface of the colored molded article.

Therefore, the carrier resin of the particulate colorant is mainly composed of isotactic polypropylene or atactic.
Various attempts have been made to improve distribution and maintain physical properties by using a viscosity-adjusted product, and a method using a low-viscosity isotactic polypropylene having a high MFR is disclosed in Japanese Patent Application No. Hei.
No. 131695 (filed on May 30).

Under these circumstances, the present inventor, when using isotactic polypropylene and syndiotactic polypropylene as the carrier resin for the particulate colorant, has a better distribution and resin properties than using a resin other than polypropylene. Admitted that the balance is good. Particularly, the isotactic polypropylene used in combination has a high fluidity (having a large MFR), which is effective in increasing the fluidity of a granular colorant containing a pigment at a high concentration.

Originally, syndiotactic polypropylene is less affected by the shear rate in the molten state than isotactic polypropylene, and has a high viscosity at high shear rates. However, syndiotactic polypropylene has a low viscosity when used in combination with high-fluidity isotactic polypropylene. The viscosity balance from high to high-speed shearing is improved, and at the same time, it contributes to the improvement of the toughness of isotactic polypropylene, and the polypropylene to be colored with a granular colorant using this as a carrier resin has improved distribution and physical properties.

The preferred combination ratio of the carrier resin is such that the isotactic polypropylene and the syndiotactic polypropylene are in a weight ratio of 19: 1 to 1: 1. Is not improved, and too much undesirably loses rigidity.

The isotactic polypropylene used in the present invention is a resin synthesized by a Ziegler-Natta catalyst, a metallocene catalyst or other catalysts, and may be a copolymer with ethylene or α-olefin. Preferably, the stereoregularity is 96 in isotactic pentad fraction.
% Or more, the MFR should be 10 or more. Preferably, the MFR is at least twice that of the syndiotactic polypropylene, and more preferably 100 or more is added to enhance the fluidity.

It is also effective to improve the performance of the carrier resin by adding a modifier thereto, and examples of the modifier include polyolefin and derivatives thereof. This includes homopolymers and copolymers obtained by synthesizing olefins containing unsaturated bonds with Ziegler-Natta or metallocene catalysts. Copolymers include multi-component copolymers containing multiple monomer units. Including. Their use is not subject to any restrictions, provided that they are compatible with isotactic polypropylene and its composites. For example, polyethylene, atactic polypropylene, ethylene / propylene copolymer, ethylene / butene-1 copolymer, propylene / butene-1 copolymer, ethylene / propylene / ethylidene norbornene-terpolymer, poly-4-methylpentene 1 Olefin / styrene copolymers such as styrene / ethylene / butene / styrene copolymer (SEBS) and hydrogenated styrene / butene rubber (HSBR);
Examples thereof include ethylene / α, β-unsaturated carboxylic acid copolymers such as EEA and EVA.

In the present invention, the molecular weight of the polyolefin or a derivative thereof as the modifier varies depending on the kind of the constituting monomer, but is usually 500 to 1,000,000.
In addition, any shape such as powder and granule and copolymerization ratio can be used without any limitation. Alternatively, the acid group of an α, β-unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid, maleic acid, fumaric acid, itaconic acid, or an anhydride thereof may be introduced into the molecule of these resins by post-treatment. There is nothing in the invention.

Examples of such a material include sun wax (trade name) of Sanyo Chemical Co., Ltd. and JSR of Nippon Synthetic Rubber Co., Ltd.
EP (trade name), TR (trade name), Dinalon (trade name), Mitsui Petrochemical Co., Ltd. high wax (trade name),
Tuffmer (trade name), Lucant (trade name), Mitsui EP
T (trade name), TPX (trade name), Evaflex (trade name) of DuPont Mitsui, P.T. E. FIG. R.
(Trade name), Asahi Kasei's ToughTech (trade name), Sumitomo Chemical Co., Ltd. Esplen (trade name), Dow Chemical Engage (trade name), Shell Chemical's Clayton G (trade name)
And the like.

In the present invention, the pigment is an essential component, and the granular colorant contains 5 to 80% by weight, but it is desirable to use the pigment with good dispersion. Pigments used in the present invention are known in the plastics processing field, for example, titanium oxide, zinc oxide, red iron oxide, titanium oxide-based baked pigment, ultramarine, cobalt aluminate, inorganic pigments such as carbon black and azo-based, quinacridone-based pigments Organic pigments such as anthraquinone-based, perylene-based, isoindolinone-based, phthalocyanine-based, quinophthalone-based, selen-based, and diketopyrrolopyrrole-based pigments; and extender pigments such as barium sulfate and calcium carbonate.

In the present invention, known pigment dispersants such as fatty acids, fatty acid metal salts, fatty acid esters, fatty acid amides and surfactants, heat stabilizers, light stabilizers, flame retardants, plasticizers, antistatic agents, lubricants, Nucleating agents or fillers can be added as needed.

In the colorant composition of the present invention, the composition ratio of the components excluding the pigment is 95 to 20% by weight. And other components may be configured to be 60 to 0% by weight.

The granular colorant of the present invention can be obtained by mixing essential components of the colorant composition and other components, and thoroughly kneading the mixture.
The shape of the kneaded material can be made into a granular material by hot cutting depending on how to be taken out from the kneading machine, or a granular material by cold cutting of a sheet or a strand, which was unexpected by the present inventor. When the granular colorant is produced by cold cutting, cutting by a cutting machine (cutter) having a rotary blade is remarkably improved, and generation of chips due to defective cutting of the granular material is reduced.

Usually, as the pigment is contained in a higher concentration, chips in a cutting machine by cold cutting are more likely to be generated, and a hot cutting device is mounted at the discharge port of the kneading extruder, and chips are formed by air suction and blowing. Although a removal device is installed, these devices are not required for the coloring agent of the present invention,
It is economical.

The granular colorant is produced in the following steps. For example, the pigment is mixed with a known pigment dispersant with a high-speed mixer or pulverizer and finely pulverized, or mixed with a low-molecular-weight olefin resin in advance with a high-speed mixer, kneaded with a Banbury mixer or a kneader, and then heated. This roll and heating 3
After being finely ground by this roll, the mixture is kneaded with a syndiotactic polypropylene, an isotactic polypropylene and other components by a kneader such as a single screw or twin screw extruder. Alternatively, all of these components are mixed at once, and melt-kneaded by a Banbury mixer, a kneader, a high-speed rotating intensive mixer, a single screw or twin screw extruder, or the like.

The particulate coloring agent of the present invention includes isotactic polypropylene, syndiotactic polypropylene, polypropylene modified with a comonomer, a polymer alloy with another polyolefin, and a polypropylene compounded with the aforementioned filler and the like. I do. In particular, it is suitable for a highly crystalline polypropylene which requires high physical properties and a polypropylene which is composited with various modifiers and fillers using the same.
The coloring agent is diluted and blended so as to have a desired pigment concentration, and is usually blended in an amount of 10 parts by weight or less based on 100 parts by weight of the resin to be colored.

[0034]

Next, the present invention will be described specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples but has a wide range of application. All parts and percentages in Examples and Comparative Examples are based on weight.

Examples 1 and 2 and Comparative Examples 1 to 4 Red iron oxide (CIPR101) and black iron oxide (CI
PR101), titanium yellow (Sb-Ni-Tioxide, CIPY53)
And titanium oxide (rutile type CIPW6) pigment, low molecular weight polyethylene and zinc stearate in a mixing ratio (parts) shown in Table 1 by a high-speed mixer.
The mixture was heated and melted and kneaded with a durer, and then the kneaded product finely ground with a three-roll mill was pulverized with a crusher to obtain irregular shaped particles having good pigment dispersion. The granules are mixed with a specific polypropylene composition shown in Table 1 or a conventional polypropylene or an ethylene resin at a compounding ratio shown in Table 1, respectively, and melt-kneaded with a single screw extruder (L / D = 27). After being extruded into a strand and cooled in a water bath at a water temperature of 20 ° C., a cylindrical master batch batch pellet having a length of 2 to 3 mm using a rotary blade cutting type pelletizer is used.
Processed to parts by weight. The obtained masterbatch color was used for investigating the mixing of powdery chips, and also subjected to an injection molding color unevenness evaluation test and a physical property test.

The results are shown in Table 2. The master batch color of the composition of the present invention has no chips and almost no color unevenness.
And the retention of various physical property values was 95% or more.

The method for evaluating color unevenness in injection molding and the method for testing physical properties are as follows. Injection molding color unevenness evaluation test: After adding the master batch color to the polypropylene or polypropylene composition shown in the table at the dilution rate (%) shown in the table and mixing, the mixture was fitted with a full flight screw (L / D = 20). It is molded into a direct gate disc mold (diameter 100, thickness 2 mm) at an injection molding machine with a mold clamping pressure of 60 tons at a molding temperature of 230 ° C, a mold temperature of 40 ° C, and a back pressure of 5 kg / cm ² .

The evaluation of the color unevenness is made based on the size of the color streak observed on the disk, and the evaluation standard is set to five levels. Injection molding property test: Add masterbatch color to the polypropylene or polypropylene composition shown in the table at the dilution ratio (%) shown in the table, mix and mix the mixture with a full flight screw (L / D = 20). Molding is performed using a physical piece mold at a molding temperature of 210 ° C., a mold temperature of 40 ° C., and a back pressure of 20 kg / cm ^{2 using} an injection molding machine with a pressure of 60 tons. The molded piece was subjected to a tensile test, a bending test, an IZOD impact test, and a thermal deformation test (HDT).

Evaluation criteria: Assuming that the physical property value of the uncolored resin is 100, the retention rate of the physical properties of the colored resin is indicated by the following criteria. ：: Retention rate of physical property value is 95% or more Δ: Retention rate of physical property value is 90% or more and less than 95% X: Retention rate of physical property value is less than 90%

[0040]

[Table 1]

[0041]

[Table 2]

The details of the raw materials in Table 1 are as follows. Low molecular weight polyethylene: molecular weight (Mn) = 5000, viscosity (CPS: 1)
40 ° C.) = 3000, softening point = 111 ° C. Zinc stearate: a mixture of stearate (55%), palmitate and myristate, melting point (differential calorimetric analysis) = 127 ° C. Isotactic PP-A: Homopolypropylene MFR (230 ° C load 2.16Kg) = 10gr / 10min Isotactic PP-B: Ethylene propylene block copolymer MFR (230 ° C load 2.16Kg) = 60gr / 10min Isotactic PP-C: Homopolypropylene MFR ( 230 ° C load 2.16Kg) = 350gr / 10min Syndiotactic PP-A: Homopolypropylene MFR (230 ° C load 2.16Kg) = 8.9gr / 10min Ethylene resin -A: Low density polyethylene MFR (190 ° C load 2.16Kg) = 50gr / 10min Ethylene resin-B: Linear low density polyethylene MFR (190 ° C load 2.16Kg) = 40gr / 10min

The details of the coloring test resin in Table 2 are as follows. Isotactic PP-D: ethylene propylene block copolymer MFR (230 ° C load 2.16 kg) = 25 gr / 10 min, tensile strength = 29.
0MPa, tensile elongation at break = 20%, flexural modulus = 1300MPa, IZ
OD impact value (1/4 ") = 50 J / m, HDT = 62 ° C

Examples 3 and 4 and Comparative Examples 5 to 7 Furnace carbon black described in Table 3 (particle size: 19 μm, PH
= 9), black iron oxide (CIPR101), Cu phthalocyanine blue (CIPB15: 1), quinacridone red (CIPR12
2) and a titanium oxide (rutile type CIPW6) pigment and a low molecular weight polyethylene were respectively mixed by a high-speed mixer at a mixing ratio (parts) shown in Table 3, and then heated and melted and kneaded by a pressure kneader. The kneaded product finely ground by this roll was pulverized with a crusher to obtain irregular-shaped granules having good pigment dispersion. The granules are mixed with a specific polypropylene composition shown in Table 1 or a conventional polypropylene or an ethylene resin at a compounding ratio shown in Table 3, respectively, and melt-kneaded with a single screw extruder (L / D = 27). Then, the mixture was extruded into strands and cooled in a water bath at a water temperature of 20 ° C., and then processed into 100 parts by weight of a cylindrical master batch batch pellet having a length of 2 to 3 mm by a rotary blade cutting type pelletizer. The obtained masterbatch color was used for investigating the mixing of powdery chips, and also subjected to an injection molding color unevenness evaluation test and a physical property test. These test methods used were different from those used in Examples 1 and 2 and Comparative Examples 1 to 4 in the color resin, but were performed under the same conditions except for the above.

The results are shown in Table 4. The masterbatch color of the composition of the present invention had no chips and no color unevenness, and the retention of various physical property values was 95% or more.

[0046]

[Table 3]

[0047]

[Table 4]

The details of the ingredients in Table 3 are as follows. Low molecular weight polyethylene: molecular weight (Mn) = 5000, viscosity (CPS: 1)
40 ° C) = 3000, softening point = 111 ° C Isotactic PP-A: Homopolypropylene MFR (230 ° C load 2.16 kg) = 10 gr / 10 min Isotactic PP-E: Homopolypropylene MFR (230 ° C load 2.16 kg) = 820gr / 10min Syndiotactic PP-A: Homopolypropylene MFR (230 ° C load 2.16Kg) = 8.9gr / 10min Ethylene resin-B: Linear low density polyethylene MFR (190 ° C load 2.16Kg) = 40gr / 10min

The details of the coloring test resin in Table 4 are as follows. PP-A with filler: ethylene block copolymerized polypropylene [MFR (230 ° C load 2.16Kg) = 50gr / 10min] 6
5 parts, ethylene-α-olefin copolymer [MFR (190 ° C
7.5 parts, ethylene-α-olefin copolymer [MFR (190 ° C load 2.16K)
g) = 0.4 gr / 10 min, specific gravity = 0.88] 7.5 parts, white talc (35
0mesh sieve, specific surface area 4.3m ² / gr, PH = 9) 20 parts, high molecular weight hindered phenol antioxidant [IRGANOX 1010 (CIB
A GEIGY)] 0.1 part and phosphorus antioxidant [IRGAFOS 16
8 (CIBA GEIGY)] The mixture mixed with a high-speed mixer in a 0.1 part configuration is mixed with a twin-screw extruder (co-rotating, L / D = 32).
A product obtained by kneading and extruding at 20 ° C. and processing into a cylindrical pellet having a length of 2 to 3 mm. MFR (230 ° C load 2.16Kg) = 20gr / 10min, tensile strength = 22.
7MPa, tensile elongation at break = 100%, flexural modulus = 995MPa, IZ
OD impact value (1/4 ") = 100J / m, HDT = 56 ℃

Example 5 and Comparative Example 8 30 parts of furnace carbon black (particle size: 16 μm, PH = 8) were combined with 40 parts of isotactic polypropylene (homopolypropylene, MFR (230 ° C., load: 2.16 kg) = 100 gr / 10 min). 30 parts of syndiotactic polypropylene [homopolypropylene, MFR (load at 230 ° C 2.16 kg) = 8.9gr / 10min] or 30 parts of ethylene copolymerized polypropylene [MFR (load at 230 ° C)
2.16 kg) = 20 gr / 10 min] and mixed with a small high-speed mixer, and then heated and melted and kneaded from room temperature to 160 ° C. with a small pressure kneader to obtain a melt in which carbon black was finely dispersed. Next, these melts taken out were shaped into a sheet and cut into pellets of several millimeters square to obtain carbon black kneaded materials A and B, each of which was made of isotactic polypropylene, ultramarine blue (CIPB29) and red iron oxide shown in Table 5.
(CIPR109) After mixing the pigment, low molecular weight polyethylene, magnesium stearate, and zinc stearate with a cylindrical tumble mixer at the mixing ratio (part) described in the same table, 2
Melt and kneaded with a shaft screw extruder (rotating in the same direction, L / D = 32), extruded into strands, cooled in a water bath at a water temperature of 20 ° C., and then 2-3 m long with a rotary blade cutting type pelletizer.
m cylindrical master batch color pellets were processed into 100 parts by weight. The obtained masterbatch color was used for investigating the mixing of powdery chips, and also subjected to an injection molding color unevenness evaluation test and a physical property test. These test methods used were different from those used in Examples 1 and 2 and Comparative Examples 1 to 4 in the color resin, but were performed under the same conditions except for the above.

The results are shown in Table 6. The masterbatch color of the composition of the present invention had no chips and no color unevenness, and the retention of various physical property values was 95% or more.

[0052]

[Table 5]

[0053]

[Table 6]

The details of the ingredients in Table 5 are as follows. Low molecular weight polyethylene: molecular weight (Mn) = 5000, viscosity (CPS: 1)
40 ° C) = 3000, softening point = 111 ° C Magnesium stearate: a mixture of stearate (55%), palmitate, and myristate, melting point (differential calorimetric analysis) = 118 ° C Zinc stearate: stearate (55%), a mixture of palmitate and myristate, melting point (differential calorimetry) = 127 ° C isotactic PP-F: homopolypropylene MFR (230 ° C load 2.16Kg) = 400gr / 10min

The details of the coloring test resin in Table 4 are as follows. Highly crystalline PP: 97% or more of isotactic pentad,
Homopolypropylene MFR (230 ° C load 2.16Kg) = 10gr / 10min, tensile strength = 38.
1MPa, tensile elongation at break = 600%, flexural modulus = 2040MPa, I
ZOD impact value (1/4 ") = 21 J / m, HDT = 74 ° C

[0056]

According to the present invention, when the specific polypropylene of the present invention is used as a carrier resin for a masterbatch color, it can be easily granulated without powder chips in the production process of the colorant, can contain a pigment at a high concentration, and has a high concentration of polypropylene and When coloring the composite material, it does not decrease the mechanical properties such as tensile strength, tensile elongation, flexural modulus, impact strength and heat deformation temperature of the molded product. And a granular colorant having good distribution properties can be provided.

As a result, it is not necessary to remove chips from the colorant, and a colorant having a high pigment concentration can be used.
As a result, the amount of the coloring agent used is reduced, so that the coloring cost can be reduced and the molding cost can be significantly reduced by improving the moldability.

Claims (5)

[Claims] 1. A colorant composition comprising a pigment and a carrier resin, polypropylene as a main component, wherein the polypropylene is a mixture of isotactic polypropylene and syndiotactic polypropylene, and the isotactic polypropylene and the syndiotactic polypropylene in the mixture. A colorant composition for polypropylene, which has a composition ratio with tic polypropylene of 19: 1 to 1: 1 by weight. 2. A colorant composition for polypropylene, wherein the isotactic polypropylene according to claim 1 has an MFR of 10 gr / 10 min or more. 3. The colorant composition according to claim 1, further comprising a carrier resin modifier as an auxiliary component. 4. The colorant composition according to claim 3, wherein the modifier for the carrier resin is a polyolefin or a derivative thereof. 5. A granular colorant (master batch color) containing 5 to 80% by weight of a pigment.
5. The colorant composition according to any one of 4.