JPH08325423A - Colorant composition for highly crystalline polypropylene - Google Patents

Abstract

PURPOSE: To obtain a colorant composition whose pigment can be easily dispersed in the molding during molding and which, when used as a colorant, can give a molding with very lowly deteriorated mechanical properties by using a pigment and a PP having an MFR in a specified range as the principal components. CONSTITUTION: This colorant composition is the one mainly consisting of a pigment and a PP as a carrier resin, wherein the MFR of the PP is in the range of 300-2,000g/10min. By using this PP resin as the vehicle resin of a masterbatch, the colorant is easily granulated in the production step, the composition can contain the pigment in a high concentration, the mechanical properties, such as tensile strength, bending modulus, impact strength and heat distortion temperature, of a molding are not deteriorated when a highly crystalline PP or a composite material thereof is colored therewith, the dispersion of the coloring component can be improved in the coloration molding such as injection, extrusion or blow molding, and therefore the segregation and color unevenness do not occur.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pigment compounded as a coloring component, which can be easily distributed to a molded product during molding of a highly crystalline polypropylene and a composite material thereof, and the mechanical properties of the molded product can be remarkably deteriorated. The present invention relates to a colorant composition which can be reduced.

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

[0003]

2. Description of the Related Art In recent years, polypropylene has been used in a wide variety of applications because it has improved moldability and physical properties due to improvements in catalysts and polymerization methods and is easy to recycle.

Particularly, polypropylene having high rigidity and high heat resistance, such as highly crystalline polypropylene having a stereoregularity and an isotactic index exceeding 98%, has been used. And these are other olefinic resins and fillers,
For example, it is extruded, melted and kneaded with ethylene / propylene rubber, talc, etc., and has high rigidity especially in the fields of automobiles and home appliances.
The amount of use as a composite material having high heat resistance is increasing.

Generally, coloring of plastics is carried out for the purpose of imparting various functions such as decorativeness to a molded product, and powdery, granular or liquid coloring agents are used for coloring in the stages of injection molding and extrusion molding. The coloring agent is a coloring component such as a pigment or a dye added with a dispersion aid, or a carrier resin is added thereto,
It is obtained by simply mixing or melt-kneading, but the coloring component changes variously depending on the material of the plastic and its use.

Pigments are used exclusively for coloring highly crystalline polypropylene and its composite materials. However, powdery colorants containing dispersion aids, so-called dry colors, cause environmental pollution at the handling stage, and are not automatically used. The weighing accuracy of the weighing machine is also poor. Therefore, a granular colorant, commonly known as a masterbatch color, is often used as one of the colorants that is easy to handle.

The masterbatch color is a product obtained by concentrating the required pigment to a maximum of about 60% by weight when coloring a plastic molded product, and kneading it in an appropriate carrier resin (also called vehicle resin) with good dispersion. Is. Therefore, it is diluted with the molding resin according to the concentration ratio and used at the stages of injection, extrusion and blow molding.

When diluting the masterbatch color into the resin to be colored, a problem is the distributability (peptizability) of the pigment in the masterbatch color to the molded product. In particular, if the pigment concentration of the masterbatch color is increased and the dilution ratio is increased (the blending ratio of the masterbatch color to the resin to be colored is reduced) in consideration of economy, the masterbatch color melts due to the pigment concentration. Since the viscosity becomes high, insufficient kneading by the molding machine occurs, resulting in color unevenness and color streaks, which are phenomena of poor distributability. In particular, highly crystalline polypropylene and its composite materials have a higher melting softening point than ordinary polypropylene and can be shortened in their molding cycle because of their faster crystallization, but doing so results in less kneading force in the molding machine. , This problem becomes noticeable.

In such a case, a method of reducing the pigment concentration of the masterbatch color to reduce the dilution ratio as a measure for eliminating color unevenness and color streaks, or a method of increasing the kneading conditions by changing the screw design of the molding machine or installing a static mixer Has been adopted. However, the method of reducing the dilution ratio of the masterbatch color and increasing the kneading conditions of the molding machine raises the coloring cost due to the increase in the unit price of the material and the increase in the capital investment amount, and the desired economic efficiency cannot be achieved.

On the other hand, various proposals have been made to improve the distributability by improving the olefin resin which is a vehicle resin for masterbatch color. For example, in JP-A-1-261440, 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 polyacrylic resin. It is disclosed as a technique for improving color unevenness in a resin such as vinyl chloride.
Further, JP-A-5-202234 discloses 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 as a vehicle for a masterbatch color. It has been shown that what is contained is extremely effective for coloring polyolefins in which physical properties such as mechanical properties and heat resistance are particularly important. Further, Japanese Patent Publication No. 6-21201 discloses a pigment and ethylene-
Master batch color consisting of vinyl acetate copolymer and polyolefin wax and neutralized carboxylic acid-containing polyolefin wax, even if the pigment content is high, not only general-purpose resins such as olefin resins and styrene resins, but also polyamide, It is disclosed as a colorant composition which has good pigment dispersion and can be easily distributed at the time of molding even for high processing temperatures such as polyacetal, that is, engineering plastics.

However, these disclosed masterbatch colors have a big problem that the effect of improving the distributability or the effect of retaining mechanical properties is particularly poor with respect to a composite material containing highly crystalline polypropylene or a filler. It was JP-A-5-202234 and JP-B-6-2
In JP-A No. 1201, the fluidity of the vehicle resin is restricted to 300 gr / 10 min or less in terms of MFR in order to increase the physical property retention, but this also causes a problem that it is difficult to increase the pigment concentration. In addition, when the MFR exceeds 300 gr / 10 min, there is a problem that it becomes difficult to granulate in the process of processing the granular colorant, which makes manufacturing difficult.

[0012]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned drawbacks, facilitates granulation in the process of producing a colorant, can contain a high concentration of a pigment, and colors a highly crystalline polypropylene and its composite material. Tensile strength of the molded product,
An object of the present invention is to provide a granular colorant which does not reduce mechanical properties such as flexural modulus, impact strength and heat deformation temperature, and does not cause color unevenness or color streaks during the molding process and has good dispersibility. .

[0013]

DISCLOSURE OF THE INVENTION As a result of intensive studies of the improvement of the dispersibility of a granular colorant, the present inventors have found that when a specific polypropylene resin is used as a vehicle resin for a masterbatch color, it is granulated in the production process of the colorant. Easy, can contain a high concentration of pigment, in the case of coloring highly crystalline polypropylene and its composite material, do not reduce the mechanical properties such as tensile strength, flexural modulus, impact strength and heat distortion temperature of the molded product, Further, it has been found that color distribution such as injection molding, extrusion molding, or hollow molding does not cause color unevenness and color streaks because of excellent dispersibility.

That is, the present invention relates to a colorant composition containing a pigment and a polypropylene as a carrier resin (vehicle resin) as a main component, and the specific polypropylene, that is, MFR (melt flow rate according to ASTM D 1238L) is 300 to. The present invention relates to a colorant composition for crystalline polypropylene characterized by using 2000 gr / 10 min, and more particularly to a granular colorant (masterbatch color) containing 5 to 80% by weight of a pigment.

The present invention will be described in detail below. The specific polypropylene used in the present invention has an MFR of 300 to 2000 gr / 10 min as described above, preferably 15 mol%.
Comprising ethylene and / or C ₄ -C ₈ alpha-olefin of up to, P. I. Value (polydispersity index) of 3.7 or less, MFR value of 600 to 1000 gr / 10 min, Mw value (weight average molecular weight) of 100,000 to 60,000, MFR value of 1000 to 2000 gr / 10 min, Mz It is characterized in that the value (Z average molecular weight) is 140,000 or more.

Specific examples of such polypropylene include those described in JP-A-7-2925, which is said to be a crystalline polypropylene having a high MFR value and a narrow molecular weight distribution. .

As the pigment used in the present invention, those known in the field of plastics processing can be used. For example, inorganic pigments such as titanium oxide, zinc oxide, rouge, titanium oxide calcined pigment, ultramarine blue, cobalt aluminate, carbon black and azo. There are organic pigments of quinacridone type, anthraquinone type, perylene type, isoindolinone type, phthalocyanine type, quinophthalone type, slene type, diketopyrrolopyrrole type and extender pigments such as barium sulfate and calcium carbonate.

In the present invention, a metal soap, a dispersant such as esters of long-chain alkyl groups and polyhydric alcohols, a heat stabilizer,
A light stabilizer, a flame retardant, a plasticizer, an antistatic agent, a lubricant or a filler can be added if necessary.

In the colorant composition of the present invention, the specific polypropylene is at least 10 to 1 in the composition ratio of the components excluding the pigment.
It is sufficient if it is 00% by weight. It is also effective to add a modifier to the carrier resin to improve its performance. The modifier is, for example, polyolefin or its derivative. Examples of such polyolefins include homopolymers and copolymers synthesized from olefins containing an unsaturated bond using a Ziegler-based or metallocene-based organometallic compound as a catalyst. Includes multi-component copolymers containing monomer units. And their use is not limited as long as it is compatible with the highly crystalline polypropylene and its composite material. For example, polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / butene-1 copolymer, propylene / butene-1 copolymer, ethylene / propylene / ethylidene norbornene terpolymer, poly-4methylpentene 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 these polyolefins or their derivatives varies depending on the kind of the constituent monomers, but it is usually 500 to 1,000,000, and the external shape such as powder and granules, density, and copolymer in the copolymer. Any stereoregularity such as polymerization ratio, isotactic, syndiotactic and the like can be used without limitation. In addition, acrylic acid, methacrylic acid,
There is no problem in the present invention even if an acid group of α, β-unsaturated carboxylic acid such as ethylacrylic acid, maleic acid, fumaric acid, itaconic acid or the anhydride thereof is introduced.

Examples of such products include Sun Wax (trade name) of Sanyo Kasei Co., Ltd. and JSR of Japan Synthetic Rubber Co., Ltd.
EP (trade name), TR (trade name), Dynaron (trade name), Mitsui Petrochemical's high wax (trade name),
Toughmer (trade name), Lucant (trade name), Mitsui EP
T (trade name), TPX (trade name), Mitsui DuPont's EVAflex (trade name), Tokuyama P.M. E. FIG. R.
(Brand name), Sumitomo Chemical Co., Ltd.'s Esplen (brand name),
Dow Chemical's Engage (product name), Asahi Kasei's Tough Tech (product name), Shell Chemical's Clayton G (product name)
Etc. can be mentioned.

The granular colorant can be obtained by mixing the components constituting the colorant and melt-kneading. For example, a pigment is previously mixed with a low molecular weight olefin resin by a high speed mixer or the like, kneaded with a Banbury mixer or a kneader, and then heated 2.
It may be obtained by finely grinding the pigment with a main roll or three heating rolls, and then kneading it with a specific polypropylene and other components with a kneading machine such as a single-screw or twin-screw extruder. , Mix all these ingredients at once,
It is a product obtained by melt-kneading with a Banbury mixer, a kneader, a high-speed rotating intensive mixer, a twin-screw extruder or the like. The shape of the kneaded product may be hot cut to give granules or cold cut sheets or strands to give granules depending on how the kneaded product is taken out from the kneader.

The colorant of the present invention, particularly the resin to be colored by the granular colorant of the present invention, is stereoregular and has a high crystallinity isotactic polypropylene having a stereoregularity index (isotactic pentad) of more than 98%. It is a polymer alloy resin of a crystalline isotactic polypropylene and another olefin resin, or a composite material using the above resin and glass or talc as a filler. The colorant is usually added in an amount of 10 parts by weight or less with respect to 100 parts by weight of the resin to be colored so as to obtain a desired pigment concentration.

[0024]

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

Examples 1, 2, 3, 4, 5 and Comparative Example 1,
2, 3 Phthalocyanine blue (monochloro α type) and titanium oxide (rutile type) pigments shown in Table 1 and low molecular weight olefin resin were mixed at a blending ratio (parts) shown in Table 1 with a high speed mixer, and then a pressure kneader. The mixture was heated and melted and kneaded by using a crusher, and then the kneaded material finely ground by a three-roll mill was crushed by a crusher to obtain an irregular-shaped granular material having good pigment dispersion. This granular material was mixed with a specific polypropylene shown in Table 1 or a conventional polypropylene or ethylene resin or ethylene / propylene copolymer at a compounding ratio shown in Table 1, respectively, and a single screw extruder (L / D = 27) was used. ) Was melt-kneaded, extruded into a strand, and processed into 100 parts by weight of a cylindrical master batch color pellet having a length of 2 to 3 mm by a pelletizer. The obtained masterbatch color was subjected to an injection molding color unevenness evaluation test and a physical property test.

The results are shown in Table 2. The masterbatch color of the composition of the present invention had no color unevenness, and the retention rate of various physical properties was approximately 95% or more.

The injection molding color unevenness evaluation test method and the physical property test method are as follows. Injection Molding Color Mottling Evaluation Test: Master batch color is made of highly crystalline isotactic polypropylene (MFR = 30gr / 10min (230 ℃, load 2.1
6Kg): Stereoregularity 99%) at the dilution rate (%) shown in Table 1 and mixed, and then the mixture is fitted with a full flight screw (L
/ D = 20) with a mold clamping pressure of 60 tons and a molding temperature of 210
Direct gate disk mold (diameter at ℃, back pressure 5Kg / cm ²
100mm, thickness 2mm).

The color unevenness is evaluated based on the occurrence of color streaks recognized on the disk, and the evaluation standard is 5 levels. Evaluation Criteria 1: There are no color streaks. 2: There is a slight color streak. 3: There are small color streaks. 4: There are large color streaks in places. 5: There is a large color streak on the entire surface.

Injection molding physical property test: The masterbatch color was changed to a highly crystalline isotactic polypropylene (MFR =
30gr / 10min (230 ℃, load 2.16Kg): Stereoregularity 99%)
After adding and mixing at the dilution rate (%) shown in Table 2, the mixture was mixed with a full flight screw (L / D = 20) at an injection molding machine with a mold clamping pressure of 60 tons and a molding temperature of 210 ° C and a back pressure of 20 kg / Mold with physical property mold at cm ² . The molded piece was subjected to a tensile test, a bending test, an IZOD impact test, and a heat deformation test (HDT).

Criteria for evaluation: The physical property value of the uncolored resin is 100, and the retention ratio of the physical property value of the colored resin is ◯: The retention ratio of the physical property value is 95% or more. Δ: The retention rate of physical property values is 90% or more and less than 95%. X: The retention rate of physical properties is less than 90%.

[0031]

[Table 1]

[0032]

[Table 2]

The details of the blended raw materials in Table 1 are as follows. Low molecular weight olefin resin: Low molecular weight polyethylene wax Molecular weight (Mn) = 5000, viscosity (CPS: 140 ° C) = 3000, softening point = 11
1 ° C Specific PP-A: Polypropylene MFR (230 ° C, load 2.16Kg) = 350gr / 10min Specific PP-B: Polypropylene MFR (230 ° C, load 2.16Kg) = 820gr / 10min PP-C: Polypropylene (homopolymer ) MFR (230 ° C, load 2.16Kg) = 40gr / 10min PP-D: polypropylene (block copolymer) MFR (230 ° C, load 2.16Kg) = 80gr / 10min Ethylene resin-A: linear low density polyethylene MFR ( 190 ℃, load 2.16Kg) = 40gr / 10min Ethylene resin-B: Low density polyethylene MFR (190 ℃, load 2.16Kg) = 50gr / 10min EPR-A: Ethylene / propylene copolymer MFR (230 ℃, load 2.16) Kg) = 8.6 gr / 10 min Ethylene / Propylene ratio 75:25

Examples 6, 7, 8 and Comparative Examples 4, 5, 6,
7,8 Furnace carbon black with primary particle size of 19mμ (oil absorption = 47 DBPml / 100gr, PH = 9) and low molecular weight olefin resin shown in Table 2 and specific polypropylene or conventional polypropylene or ethylene resin or ethylene / The α-olefin copolymer or the ethylene / propylene copolymer was mixed in a mixing ratio (part) shown in Table 3 in a high-speed mixer, melt-kneaded in a Banbury mixer, and the melted product was taken out by a two-roll mill. It was processed into a sheet and processed into 100 parts by weight of a masterbatch color pellet of 3 to 5 mm square with a square pelletizer. The obtained pellets were subjected to the injection molding color unevenness evaluation test and the physical property test as in Examples 1 to 5.

The injection molding color unevenness evaluation test and the physical property test method were carried out in place of the highly crystalline polypropylene described in Examples 1 and 2 by using a highly crystalline polypropylene (MFR = 30 gr).
/ 10min, 230 ℃ load 2.16Kg: Stereoregularity 99%) 70 parts and ethylene / butene-1 copolymer (MFR = 20gr / 10m
in, 190 ℃ load 2.16Kg) 10 parts and talc (average particle size = 2.
(3 μm) 20 parts were extruded (barrel temperature: 230 ° C.) to obtain white pellets, and the same procedure as in Examples 1 to 5 was performed.

The results are shown in Table 4. When polypropylene is used, ethylene resin or ethylene / α is used.
Compared to the case of using the olefin copolymer, the masterbatch color of the composition of the present invention had no color unevenness and the physical property retention rate was generally 95% or more.

[0037]

[Table 3]

[0038]

[Table 4]

Details of the blended raw materials in Table 3 are as follows. Low molecular weight olefin resin: high oxidation type low molecular weight polyethylene Molecular weight (viscosity method) = 3200, viscosity (CPS: 140 ° C) = 550 Acid value (KOHmg / g) = 20, softening point (° C) = 115 Specific PP- A: Polypropylene MFR (230 ° C, load 2.16Kg) = 350gr / 10min Specific PP-B: Polypropylene MFR (230 ° C, load 2.16Kg) = 820gr / 10min PP-D: Polypropylene (block copolymer) MFR (230 ° C, Load 2.16Kg) = 80gr / 10min PP-E: Polypropylene (block copolymer) MFR (230 ° C, load 2.16Kg) = 500gr / 10min Polypropylene (block copolymer) (MFR (230
℃, load 2.16Kg) = 50gr / 10min) 2,5-dimethyl in 100 parts
Add 0.02 parts of -2,5- [ter-butylperoxy] hexane and adjust the barrel temperature to 2
It was produced by extrusion at 30 ° C. Ethylene Resin-C: Low Density Polyethylene MFR (190 ℃, Load 2.16Kg) = 70gr / 10min EAO-A: Propylene / Butene-1 Copolymer MFR (230 ℃, Load 2.16Kg) = 20gr / 10min Propylene / Butene 1 ratio = 80/20 EPR-B: ethylene / propylene copolymer Mooney viscosity (ML1 + 4,125 ° C.) = 52 ethylene / propylene ratio 55:45

Examples 9, 10, 11, 12 and Comparative Example 9,
10, 11 Ultramarine blue listed in Table 3 (Ultramarine blue: particle size 0.7μ
m) and titanium oxide (particle diameter 0.18 μm) and primary particle diameter
18 μm furnace carbon black (oil absorption = 47 DBP
ml / 100 gr, PH = 9) and specific polypropylene or conventional polypropylene or ethylene / ethyl acrylic acid copolymer or hydrogenated styrene / butadiene rubber or ethylene / propylene copolymer and metal soap in the mixing ratios shown in Table 3, respectively. After mixing with a high-speed mixer, heat and knead with a co-rotating twin-screw extruder (L / D = 35), and process the extrudate in the form of strands into cylindrical master batch color pellets with a length of 2-3 mm. did. The obtained pellets were subjected to the injection molding color unevenness evaluation test and the physical property test as in Examples 1, 2, and 3.

The injection molding color unevenness evaluation test method was carried out by using a highly crystalline polypropylene block copolymer {MFR = 30 instead of the highly crystalline polypropylene described in Examples 1 and 2.
gr / 10min (230 ℃, load 2.16Kg), stereoregularity 99%} 7
0 parts and ethylene / butene copolymer {MFR = 4gr / 10min
(230 ° C, load 2.16Kg)} 10 parts and ethylene / propylene copolymer {MFR = 3.2gr / 10min (230 ° C, load 2.16Kg),
Propylene content 26%} 10 parts and talc (average particle size = 2.3 μm) 10 parts were extruded (barrel temperature 230 ° C.) to obtain white pellets obtained by the same method as in Examples 1 and 2. It was

The results are shown in Table 6. Compared with the case of using the conventional polypropylene, the masterbatch color of the composition of the present invention has almost no color unevenness and the physical property retention rate is about 9.
It was 5% or more.

[0043]

[Table 5]

[0044]

[Table 6]

Details of the blended raw materials in Table 5 are as follows. Specific PP-B: polypropylene MFR (230 ° C, load 2.16Kg) = 820gr / 10min PP-F: polypropylene (block copolymer) MFR (230 ° C, load 2.16Kg) = 700gr / 10min polypropylene (block copolymer) (MFR ( 230
℃, load 2.16Kg) = 80gr / 10min) 2,5-dimethyl in 100 parts
Add 0.02 parts of -2,5- [ter-butylperoxy] hexane to give a barrel temperature of 2
It was produced by extrusion at 30 ° C. EEA-A: ethylene / ethyl acrylic acid copolymer MFR (190 ° C, load 2.16Kg) = 25gr / 10min ethylacrylic acid content 17% by weight HSBR-A: hydrogenated styrene / butadiene rubber MFR (230 ° C, load 2.16Kg) Kg) = 3.5 gr / 10 min Styrene content 10% by weight EPR-C: ethylene / propylene copolymer MFR (190 ° C., load 2.16 Kg) = 20 gr / 10 min Ethylene / propylene ratio = 20/80 Metal soap: stearic acid zinc

[0046]

When the specific polypropylene of the present invention is used as a vehicle resin for a masterbatch color, it is easy to granulate in the manufacturing process of the colorant, the pigment can be contained in a high concentration, and the highly crystalline polypropylene and its composite material. In the case of coloring, the mechanical strength of the molded product such as tensile strength, flexural modulus, impact strength and heat distortion temperature is not reduced, and color unevenness and color streaks do not occur in the molding step,
A granular colorant having good dispersibility can be provided.

As a result, it becomes possible to use a high-concentration colorant, which reduces the amount of colorant used, so that the coloring cost can be reduced and the molding cost can be greatly reduced by improving the moldability.

Claims (5)

[Claims] 1. A colorant composition comprising a pigment and polypropylene as a carrier resin as a main component, wherein the polypropylene has a MFR of 300 to 2000 gr / 10 min. 2. The colorant composition according to claim 1, further comprising a carrier resin modifier as an accessory component. 3. The colorant composition according to claim 2, wherein the modifier of the carrier resin is polyolefin or its derivative. 4. The colorant composition according to claim 1, which is a granular colorant (masterbatch color) containing 5 to 80% by weight of a pigment. 5. The coloring according to claim 1, wherein polypropylene having a high crystallinity with a stereoregularity index (isotactic pentad) of more than 98% is a coloring object. Agent composition.