JPS6144943A - Colored resin composition - Google Patents

Abstract

PURPOSE:A colored resin composition for use as a masterbatch, containing a coloring agent uniformly in a high concentration, obtained by incorporating a coloring agent into a modified resin prepared by the graft polymerization of an alpha-olefin polymer with an aromatic vinyl monomer. CONSTITUTION:100-20wt% modified resin (A) containing 5-70wt% aromatic vinyl monomer units, prepared by the graft polymerization of an alpha-olefin polymer resin (e.g. a propylene-ethylene random copolymer) having a melt flow index of 0.1-400g/10min with an acromatic vinyl monomer (e.g. styrene), and 0- 80wt% alpha-olefin or styrene polymer resin (B) (e.g. a styrene-acrylonitrile copolymer) are mixed. 100pts.wt. resin component thus obtained and 3-150pts.wt. coloring agent consisting of organic or inorganic pigments are mixed uniformly to give an objective colored resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to coloring of various plastics, and relates to a colored resin composition containing a coloring agent highly uniformly.

(Prior Art) Plastic coloring methods can be roughly divided into dry coloring methods, colored pellet methods, and color masterbatch methods.

Among these, the color masterbatch method has the following advantages: (1) excellent pigment dispersibility, (2) high pigment concentration, (3) easy handling, and (A) dispersibility. The coloring method has a number of advantages, including no contamination, (5) dilution to any desired concentration, (6) convenient measurement, and (7) easy storage. It is by far the most dominant method among them, and it occupies a large position especially in the coloring of polyolefin resins. The resin component for the masterbatch needs to have good compatibility with the matrix resin used, and in addition, it is necessary to fill and mix the colorant in a high concentration and uniformly. Furthermore, since it is necessary not to greatly deviate between the fluidity levels of the masterbatch and the matrix resin, it is better to have a crystalline one with a low melting point, and a non-grade one with a low glass transition point, and both of which have a low melt viscosity. A certain degree of low value is preferable.

Specifically, for example, in the case of polyolefin, polyethylene wax, low density polyethylene, linear low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer (EVA), etc. are representative.

On the other hand, styrenic resin, namely polystyrene (PS
), high-impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene copolymer (ABS), as well as polycarbonate, modified polyphenylene oxide (modified-PPO), polysulfone, polyethylene terephthalate (PET), polybutylene. The main methods for coloring engineering resins such as terephthalate (PBT) are the dry color method or the colored pellet method, and the color masterbatch method is not often used.

(Impact point to be solved by the invention) Styrene resins and the aforementioned engineering resins have poor pigment dispersibility compared to polyolefin resins, and even in the dry color method and colored pellet method, it is difficult to There are restrictions on the type and concentration of pigment dispersants, and pigment dispersants used to improve pigment dispersion can cause stains on the surface of colored molded products and deterioration of physical properties. The reality is that the desired colored molded product cannot be obtained unless the process is strictly controlled.

Further, the reason why the color masterbatch method is not widely adopted is that a suitable resin component for masterbatches that satisfies the various requirements of the color masterbatch method described above has not been obtained. For example, a color masterbatch containing a high concentration of pigment based on a mixture of polyethylene wax and polyethylene or EVA has excellent manufacturability and is extremely useful for polyolefin resins. When applied to styrene resins and engineering resins, the dispersibility of the masterbatch is poor due to poor compatibility between the masterbatch resin components and these resins, resulting in uneven coloring and flow marks on molded products. This deteriorates the appearance and reduces the mechanical properties of the molded product.If styrene resin itself is used as the material for the master patch, there are the following problems: Coloring due to the high melt viscosity of the polymer. (The melt flow index value according to JIS-6871 is 3 Of/10 min for polystyrene and 8 F/10 min for ABS.)
10 minutes). Therefore, depending on the type of pigment, in many cases it is almost impossible to increase the filling amount, and if the concentration of the masterbatch is forced to be increased, the dispersibility of the pigment will be extremely reduced.

Attempts have also been made to use low molecular weight polystyrene or styrene-grafted polyolefin wax as a pigment dispersant in the dry color method or the 2-doverette method, or as a resin for a masterbatch in the color masterbatch method. When these low-molecular-weight polymers are used as dispersants in the colored pellet method, their low melt viscosity often impedes cross-wire workability with styrenic resins and engineering resins. In particular, when applied to engineering resins with high melting points or high glass transition points, the set temperature of the kneading extruder is high and the viscosity decreases near the feed hopper mouth, causing crosstalk problems or even worsening pigment dispersibility. Special feeding methods must be considered. Furthermore, when these low molecular weight polymers are used as resins for color masterbatches, when the pigment concentration becomes high, the melt viscosity becomes too small, making it difficult to disperse the pigment particles finely and uniformly (shear stress caused by crosstalk). In addition, when manufacturing the masterbatch,
The shape of the struts produced using a conventional extruder is flaky. Flake-like masterbatches often cause problems during the actual coloring and molding process, as they interfere with smooth transportation through the molding machine hopper and transport pipe.

(Objective of the invention) The present invention has been made with the aim of supplying a colored molded body or a colorant masterbatch that does not have such drawbacks, and by using a specific resin component, the dispersibility due to colorant crosstalk can be reduced. The present invention provides a colored resin composition which can be made into a good and highly concentrated masterbatch and which has excellent FIJ and mold quality (appearance, mechanical properties, etc.).

(Means for solving the problem) That is, the present invention provides (A) melt flow index (
An aromatic vinyl monomer unit content of 5 to 70% by weight obtained by subjecting an α-olefin polymer resin with MFR) of 0.1 to 4 oot/1o and an aromatic vinyl monomer to graft polymerization conditions. 100 to 20% by weight of modified resin and ■α-olefin or styrenic polymer resin 0 to 20% by weight.
100 parts by weight of a resin component consisting of 80% by weight, and (C')
This is a uniformly colored resin composition characterized by comprising 3 to 150 parts by weight of a colorant.

Since the composition of the present invention is excellent in the above points, it is also effective as a colorant masterbatch for various matrix resins.

(Function) The above component (A) used in the present invention has an MFR of 0.1 to 4.
00 f710 minutes, preferably 5 to 200 f/lO of α-olefin polymer resin and aromatic vinyl monomer are subjected to graft polymerization conditions, and the aromatic vinyl monomer unit content is 5 to 70 minutes. % by weight, preferably 25-70% by weight of modified resin.

The MFR referred to here is defined in JIS-6758 (propylene polymers) or JIS-6760 (ethylene polymers). This is a value measured at °C. When using an α-olefin polymer with an MFR of less than o, 1 r/lo min, the extrusion torque of the resin increases and shear heat generation increases, making it difficult to fill the colorant at a high concentration. Moreover, when it is larger than aoof/lo, the crosstalk workability with the pigment is poor, and the mechanical strength of the molded product obtained by granulating the masterbatch is deteriorated. Contains one unit of aromatic vinyl monomer: If the amount is less than 5% by weight, no improvement in compatibility with different types of matrix resins can be expected, and if it exceeds 70% by weight, it is not suitable for uniformly kneading the colorant at a high concentration.

Here, the α-olefin polymer resin is a crystalline polypropylene-based polymer such as a propylene homopolymer, a copolymer mainly composed of propylene with other α-olefins or ethylene, or with an unsaturated organic acid or its derivative. A group of resins are preferably mentioned.

Specifically, representative examples include isotactic polypropylene, propylene-ethylene random copolymer, propylene-ethylene block copolymer, propylene-butene-1 random copolymer, and maleic anhydride-modified polypropylene. Furthermore, the following ethylene polymers are preferably mentioned. That is, in addition to high, medium, and low density ethylene polymers, the majority of ethylene and other monomers, such as vinyl esters (vinyl acetate, etc.), unsaturated organic acids or their derivatives (acrylic acid, methacrylic acid, maleic anhydride, , methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, metal salts of acrylic acid, metal salts of methacrylic acid, etc.), α-olefins (propylene, butene-1, pentene-1,4-methylpentene=1, hexene Suitable are block, random or graft copolymers with esters such as heptene-1, heptene-1, octene-1, etc.).

Among these, propylene-ethylene random copolymer, propylene-butene-1 copolymer, (EVA), styrenic monomer copolymerized with ethylene-ethyl acrylate, such as styrene, nuclear-substituted styrene (e.g.
methylstyrene, isoglobylstyrene, chlorstyrene), α-substituted styrene (e.g. EVA, α-methylstyrene, α
ethylstyrene), etc. Also, styrene and acrylic ester, styrene and methacrylic ester,
Mixed systems such as styrene and acrylonitrile are also applicable.

Among these, when styrene is used, it is possible to reduce the molecular weight of the polystyrene by-produced in addition to the styrene graft chains by selecting polymerization conditions, which is preferable. Further, it is preferable to use styrene in combination with a long chain acrylate such as n-butyl acrylate or 2-ethylhexyl acrylate, since the glass transition point of the modified resin can be lowered.

As the graft polymerization conditions, conventional methods such as melt grafting, solution grafting, suspension grafting, radiation grafting, and gas phase grafting can be employed, but preferably, for example, the following method can be used.

That is, 30 to 95% by weight of α-olefin polymer particles, 70 to 5% by weight of aromatic vinyl heptamer, and a radical polymerization initiator having a decomposition temperature of 50 to 150°C to obtain a half-life of 10 hours are used as an aromatic compound. An aqueous suspension containing 0.01 to 5 parts by weight based on 100 parts by weight of group vinyl heptamine is heated under conditions that substantially no decomposition of the initiator occurs;
The aromatic vinyl monomer is impregnated into the α-olefin polymer particles so that the amount of free aromatic vinyl monomer is 20% by weight.
The temperature of the aqueous suspension is then raised to complete the polymerization of the aromatic vinyl heptamer.

Among the modified resins obtained in this way, preferred are:
These are styrene-modified EVA, styrene-modified low-density polyethylene, and styrene-modified propylene-ethylene random copolymer.

Next, the α-olefin polymer resin which is the component (C) used in the present invention can be appropriately selected from the α-olefin polymer resins listed above. The styrene polymer resin has at least 25 methyl groups in the structural unit represented by the following general formula, and p is 0 or an integer of 1 to 3.

) Specifically, polystyrene rubber modified I raw polystyrene,
Examples include homopolymers and copolymers of styrene and its derivatives, such as styrene-acrylonitrile copolymer and styrene-butadiene-acrylonitrile copolymer. Blends of these resins with styrene-conjugated diene block copolymer rubber and hydrogenated products thereof are also applicable.

These α-olefin polymer resins and styrene polymer resins, which are components (), can be used in combination.

Further, examples of the zero-component coloring agent used in the present invention include raw pigments conventionally used in color molding of thermoplastic resins, and processed pigments consisting of pigments, dispersants, and other additive components. . Specific examples of pigments include titanium white (rutile), titanium white (anatase), titanium yellow, cadmi yellow, isoindolinone yellow, polyazo yellow, quinophthalone yellow, phthalocyanine clean, phthalocyanine blue, ultramarine blue, cobalt blue, Polyazo brown, red red, polyazo red, perylene red, quinacridone red,
There are organic and inorganic pigments such as aniline black and carbon black. 3 to 150 parts by weight of colorant per 100 parts by weight of the resin component of olefinic or styrene polymer resin 0 to 80% by weight, preferably 60% by weight or less,
Preferably it is 5 to 100 parts by weight.

If the modified resin is less than 20% by weight, the compatibility with the different matrix will be unsatisfactory, and if the colorant exceeds 150 parts by weight, sufficient melt-kneading with the resin will not be possible, making it unsuitable as a seamaster batch. .

In the present invention, other components such as an antioxidant, a weather resistance improver, an antistatic agent, and a plasticizer can also be contained.

As an embodiment of the present invention, for example, the following method can be applied.

(1) A method of coloring and molding various matrix resins using colorant masterbatch pellets consisting of the above (A) + (B) + (Q). The matrix is PSXABS.

Polycarbonate, modified ppo, ppo, acrylonitrile-styrene resin, 6 nylon, 6.6 nylon,
Particularly good results are obtained with PBT, PET, etc.

(2) (A)+(B)+(Q10) Colored pellets made of the above matrix resin, method.

(3) A method of coloring and molding using an existing color masterbatch for α-olefin polymers (the paste resin is an α-olefin polymer), components (A) + (B), and a matrix resin.

The composition of the present invention, for example, the masterbatch composition of method (1) above, is sufficiently melt-blended and granulated using a high shear mixer such as a Banbury mixer, a roll mixer, or a twin screw extruder. . A twin-screw extruder is particularly preferred in that the masterbatch can be obtained in one step.

(Example) Example I MFR measured with JIS-6760 is 80? Quinacridone: Perylene Red: Stearic Acid 25 parts by weight of a red pigment consisting of magnesium (dispersant) in a ratio of 1:1:1 was thoroughly mixed in a super mixer. This powder mixture was melt-kneaded in a co-rotating twin-screw extruder to obtain granulated pellets (masterbatch). The cross-wire extrusion conditions were a cylinder temperature of 130°C to 150°C, a die temperature of 150°C, and a screw rotation speed of 20 Orpm. As a result of the experiment, there was no increase in cylinder temperature and no overload of the motor (screw motor current was 8 to IOA, normal operating range).
Masterbatch pellets with uniform particle size could be produced by stably extruding them into strands.

Comparative Example I MFR3or7 measured at 6s7t on JI S-
25 parts by weight of the same red pigment used in Example 1 was triblended in a super mixer to 100 parts by weight of a powder obtained by freezing and pulverizing 10-minute polystyrene to an average particle size of about 80 microns. We attempted to manufacture masterbatch pellets under these conditions. As a result of the experiment, the screw torque was large and the resin temperature rose, resulting in a sharp drop in viscosity and poor dispersibility of the pigment, making it difficult to take it in the form of strands and pelletize it.

Example 2 MF'R measured with JIS-6760 is 150t/1
60% by weight of a powder obtained by freezing and pulverizing a modified polymer obtained by graft polymerizing 35% by weight of styrene monomer and 15% by weight of 2-ethylhexyl acrylate on a portion of EVA to an average particle size of about 80 microns; MFR6or/1
100 parts by weight of a tri-blend of 40% by weight of low-density PE powder with an average particle size of about 150 microns in a super mixer, and 1.4 parts by weight of the same red pigment used in Example 1. The mixture was mixed to produce masterbatch pellets under the same conditions as in Example 1. The stability of the extruded strand was also good, and a masterbatch in which a high concentration of pigment was well dispersed was obtained.

Comparative Example 2 20 parts of the same red pigment used in Example 1 was added to 100 parts of a tri-blend of the same amount of polystyrene powder as used in Comparative Example 1 in a super mixer. Attempts were made to produce a masterbatch. The manufacturing conditions were a cylinder temperature of 150°C to 180°C, a die temperature of 180°C, and a screw rotation speed of 20 Orpm.

Compared to Comparative Example 1, the screw torque is slightly smaller due to the blending effect of low-density PE, and the rise in resin temperature is relatively suppressed, but the blending compatibility between polystyrene and low-density PE is poor, and the exit of the strand die Due to severe eye stains around the area and partial fibrillation (due to delamination) of the extruded strands,
It was not possible to obtain uniform masterbatch pellets in which the pigment was sufficiently uniformly dispersed.

Example 3 A modified polymer obtained by graft polymerizing 80% by weight of styrene monomer to a propylene-ethylene random copolymer having an MFR of 6f/10 minutes as measured by JIS-6758 was made into a modified polymer having an average particle size of about 80 microns. 100 crushed powder
The same red pigment used in Example 1, based on parts by weight, 2
Masterbatch pellets were produced in the same manner as in Example 1 by adding 0 parts by weight.

It was rpm.

There was little variation in the amperage of the screw motor, the strand take-up condition was stable, and a masterbatch with a good pellet shape was obtained.

Application example I HIPS (Dialex HT-8 manufactured by Mitsubishi Monsanto)
8) Injection molding of a material in which 2.5 or 5 parts by weight of the masterbatch obtained in Example 1 with a pigment concentration of 25 parts by weight was added to 100 parts by weight was attempted. Using a 6゛O2 screw in-line injection molding machine, the molding conditions are molding temperature 220℃, back pressure 6 to 9/- and 1sKp/64, injection pressure 600~/-1, injection speed 2see/5hot.
, the mold temperature was 76°C.

The obtained molded article had a good appearance without uneven pigment dispersion or flow marks. In addition, a part of the molded product was cut out, a 0.1-can film was made by press molding, and the pigment dispersibility was observed using an optical microscope, but there were almost no large pigment aggregates (75 microns or more). It was found that good dispersibility was observed with no visible signs of dispersion. Table 1 shows the physical properties of the injection molded product.

(Space below) Application example 2 The masterbatch obtained in Example 1 and the masterbatch obtained in Example 3 (pigment concentration Injection molding of materials to which 5.2.5 parts by weight of 20 parts by weight) were added was attempted. Using a 6 oz screw in-line injection molding machine, the molding conditions were molding temperature 2.
70℃, injection pressure 1.000 K9/di, injection speed 2
sec/5hot, and the mold temperature was 80°C. The obtained molded article had a good appearance without uneven pigment dispersion or flow marks.

Table 2 shows the physical properties of the injection molded product.

(Left below) Application example 3 Polycarbonate resin (Kneepilon C manufactured by Mitsubishi Gas Chemical Co., Ltd.)
-3000) Injection molding of a material in which 2 parts by weight of the masterbatch having a pigment concentration of 40 parts by weight obtained in Example 2 was added to 100 parts by weight was attempted.

As in Application Examples 1 and 2, the appearance and physical properties of the molded product were measured. In particular, in terms of appearance, the base resin of the masterbatch has good fluidity and has the effect of lowering the viscosity of the matrix polycarbonate, making it possible to obtain high-gloss molded products even at relatively low mold temperatures. Ta. The molding conditions were a molding temperature of 270°C and an injection pressure of 1. o
o o Kq/cd.

Injection speed 2see/5hot, mold temperature 70℃
And so.

Table 3 shows the physical properties of the injection molded product.

(Leaving space below) Example 4 5% by weight of the modified polymer powder in Example 3 1.5 parts by weight of the red pigment in Example 1 95% by weight of HIPS (Dialex HT-88 manufactured by Mitsubishi Monsanto) in a super mixer Mix thoroughly. This mixture was melt-kneaded using a single screw extruder (A0% diameter, L/D=22) to obtain color pellets. The kneading and extrusion conditions were: cylinder temperature 220°C, die temperature 215°C, screw rotation speed 6.
Or, p, m. Injection molding was performed in the same manner as in Application Example 1 using the obtained color pellet.

The obtained molded product had a good appearance with no uneven pigment dispersion or flow marks. It was also found that the physical properties of the injection molded product were good, and that an excellent balance of physical properties and appearance could be obtained. Table 4 shows the physical properties of the injection molded product.

Example 5 Low density polyethylene (MFR4s y/10 minutes) 10
0 Heavy Kawabe Gray pigment consisting of titanium white/carbon black 50 parts by weight Magnesium stearate (dispersant) 10
50% by weight of a color masterbatch for polyolefin resin consisting of parts by weight and 50% by weight of the modified polymer in Example 2
and were melt-kneaded in a co-rotating twin-screw extruder to obtain granulated pellets. Injection molding of a material prepared by adding 2 parts by weight of these colored pellets to 100 parts by weight of polycarbonate (Nipilon C-3000 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was attempted. The molding conditions were a molding temperature of 270°C and an injection pressure of 1. o o o Kq/
ltl, injection speed 2 see /5ho - mold temperature 70
℃. The obtained molded article has good pigment dispersion and an excellent appearance. Table 4 shows the physical properties of the injection molded product.

(Left below) (Effects of the invention) The present invention has good dispersibility, so it can be used as a dispersant or as a highly concentrated masterbatch, and has good compatibility with the matrix resin, so it is advantageous. This has the effect of improving the appearance, mechanical strength, etc. of the molded product.

Patent applicant: Mitsubishi Yuka Co., Ltd. Agent: Patent Attorney Hidetoshi Furukawa Agent: Patent Attorney Masahisa Nagatani Ql Take

Claims (1)

[Claims] (A) Melt flow index is 0.1 to 400g/
Modified resin 1 having an aromatic vinyl monomer unit content of 5 to 70% by weight obtained by subjecting an α-olefin polymer resin and an aromatic vinyl monomer to graft polymerization conditions for 10 minutes
00 to 20 parts by weight, and (B) 100 parts by weight of a resin component consisting of 0 to 80% by weight of an a-olefin or styrene polymer resin, and (C) 3 to 150 parts by weight of a coloring agent consisting of an organic or inorganic pigment. A uniformly colored resin composition characterized by comprising: