JPH11172097A - Colored resin composition for powder molding - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Using thermoplastic polyurethane resin powder,
When a molded product having a matte and / or grained surface is manufactured by slush molding, it is difficult to maintain the surface state, and gloss is produced over time and the grained pattern disappears. SOLUTION: In a composition mainly composed of a thermoplastic polyurethane resin powder, a urethane resin powder is used as a paste colorant obtained by using a phthalate ester plasticizer converted into an alkyl ester having 9 to 12 carbon atoms as a vehicle component. And dry blending with 1 to 20% by weight. Maleimide polymer fine particle powder that does not melt at the molding temperature may be blended. The resulting molded article does not lose its luminous pattern due to the increase in gloss over time and the occurrence of reflected light,
Luxury and other appearances are not impaired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for suppressing surface gloss,
The present invention relates to a colorant composition for powder molding, which is mainly composed of a thermoplastic polyurethane resin powder and is suitable as a material for molding automotive interior parts such as so-called matted instrument panels and door trims.

[0002]

2. Description of the Related Art Conventionally, a vinyl chloride powder slush molded product is often used as a skin material for automobile interior parts such as instrument panels and door trims.

However, a vinyl chloride-based material requires a plasticizer in order to give a soft feeling, and when used for a long time, the plasticizer contained in the material is transferred to the surface by heat, light, etc. Soft feeling is impaired. In addition, it has been pointed out that when an automobile in which it is used is scrapped after being scrapped, the incinerator is corroded by hydrogen chloride gas generated at that time.

[0004] In order to solve these problems, development of a powder slush molding material mainly composed of a thermoplastic polyurethane resin powder has been advanced as an alternative to the vinyl chloride-based material. Incidentally, the powder slush molding method referred to here is to fill the powder into a mold heated to 200 to 240 ° C., rotate the powder to weld the powder to the inner surface of the mold, discharge the undeposited powder from the mold, and collect the powder. Means a method of forming a skin material.

[0005]

However, when a thermoplastic polyurethane resin is colored by a dry blending method, it is difficult to achieve uniform coloring with a powdery colorant, and even when a liquid colorant is used. In addition, it is difficult to achieve proper coloring and the colored powder is sticky, powder does not sufficiently flow into the details of the mold during molding, and a uniform molded product cannot be obtained, or the liquid vehicle bleeds over the molding surface over time, There is a disadvantage that impairs. Further, there is a defect that the skin surface is deteriorated with time (for example, heat received from direct sunlight in an automobile) due to heat, and gloss is generated, and a grain pattern provided for giving a sense of quality disappears. That is, even if the obtained molded article has a matte surface and / or grain pattern before molding, its durability over time is poor and its surface state cannot be sufficiently maintained. Therefore, the present inventors have found that searching for a colorant and an auxiliary agent that does not impair the uniform coloring property and moldability and the appearance over time is an object to be solved at present. As a result, an invention relating to an auxiliary agent has been made, and a patent application has already been filed as Japanese Patent Application No. 8-233110.

According to the present invention, among the above-mentioned problems, the disadvantage of being deteriorated by heat with the passage of time and impairing the appearance has been solved.
There is a problem that uniform colorability and moldability cannot be obtained. For this reason, more effective measures were required.

[0007]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that a phthalic acid-based plasticizer converted into an alkyl ester having 9 to 12 carbon atoms and a maleimide as needed are added to a thermoplastic polyurethane-based resin composition. By dry blending the polymer fine particle powder, it has been found that uniform coloring properties and moldability, the appearance of gloss of the skin material can be prevented, and the grain pattern can be maintained for a long period of time, and the present invention has been completed.

That is, the present invention relates to a resin composition mainly composed of a thermoplastic polyurethane resin powder for use in powder slush molding and the like, wherein a phthalic acid plasticizer converted into an alkyl ester having 9 to 12 carbon atoms is used as a vehicle. The present invention relates to a colored resin composition for powder molding, characterized by containing a coloring agent.

The resin composition is obtained by dry blending the thermoplastic polyurethane resin powder and a colorant using a phthalic acid plasticizer as a vehicle together with a maleimide polymer fine particle powder and other auxiliaries as required. Is preferably used.

In the above resin composition, it is important that the phthalic acid plasticizer is contained in an amount of 1 to 20% by weight based on the thermoplastic polyurethane resin powder.

[0011] The resin molded product obtained by powder molding using the resin composition constituted as described above as a raw material has a matte surface and has a good matting state holding durability. The present invention also relates to a molded article having the resin composition as a material and having a grain pattern on the surface thereof, and to a point that the composition is selected as a molding material for a resin molded article having a matte surface. Things.

[0012] Such a molded article has good durability of the grain pattern, and the matte surface of the grain pattern gives the molded article a sense of quality.

The present invention also relates to a colorant for a thermoplastic polyurethane resin powder used for powder slush molding or the like, which contains, as a vehicle, a dye and a pigment and a phthalic acid-based plasticizer converted into an alkyl ester having 9 to 12 carbon atoms. And a paste-like colorant.

[0014]

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

Specific examples of the phthalic acid plasticizer converted into an alkyl ester having 9 to 12 carbon atoms used in the present invention include:
Various commercially available alkyl phthalate esters such as diisononyl phthalate, dinonyl phthalate, ditridecyl phthalate, didecyl phthalate, diisodecyl phthalate, and diundecyl phthalate are exemplified.

These phthalic acid plasticizers may be used alone or in a combination of two or more.
Among these, didecyl phthalate and diisodecyl phthalate are particularly preferred from the viewpoint of uniform coloring and moldability.

If the alkyl group has less than 9 carbon atoms, the alkyl group has fogging properties, that is, the plasticizer is vaporized by heat, and fogging occurs when it comes into contact with the glass surface. If the number of carbon atoms in the alkyl group exceeds 12, the compatibility with the thermoplastic urethane resin powder decreases, and uniform coloring cannot be obtained, which is not preferable.

The mixing ratio of the phthalic acid-based plasticizer is 1 to 20 with respect to the thermoplastic polyurethane-based resin powder.
% By weight. Above all, the range of 10 to 15% by weight is particularly preferable in view of uniform coloring, moldability, and durability of the skin material.

When the blending ratio of the phthalic acid-based plasticizer is less than 1% by weight, it is difficult to obtain a uniform coloring property. If the content is more than 20% by weight, the colored urethane resin powder is sticky, the slush moldability is deteriorated, and the durability of the skin material is undesirably reduced.

Prior to preparing the resin powder of the present invention, it is preferable to prepare a paste-like colorant using a phthalic acid-based plasticizer as a vehicle. ９５95% by weight. Above all, the range of 45 to 90% by weight is particularly preferable from the viewpoints of handling properties as a colorant, dispersibility of dyes and pigments, and mixing with resin powder.

The dyes and pigments may be organic or inorganic, and may be chromatic or achromatic. An extender and a filler may be used. Any of them can be appropriately selected and used.

Specific examples of the maleimide polymer fine particle powder used as required in the present invention include N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, -T-butylmaleimide, N-cyclohexylmaleimide, N-2-ethylhexylmaleimide, N-
Decylmaleimide, N-dodecylmaleimide, N-octadecylmaleimide, N-cyclododecylmaleimide,
N-phenylmaleimide, N-0-methylphenylmaleimide, N-benzylmaleimide, N-phenyl-2-
Examples thereof include those obtained by subjecting a maleimide compound such as chloromaleimide or N-benzyl-2-methylmaleimide to a radical generator in an alcohol-based non-aqueous solvent and polymerizing the same.

In addition, the maleimide compound and another monomer having copolymerizability can be copolymerized within a range not exceeding 20% by weight.

If the amount of the other monomer exceeds 20% by weight, the heat resistance of the obtained maleimide polymer fine particle powder is impaired, which is not preferable.

Specific examples of other monomers include styrene-based monomers such as styrene and α-methylstyrene,
(Meth) acrylates such as methyl (meth) acrylate, butyl (meth) acrylate, β-hydroxyethyl (meth) acrylate, (meth) acrylonitrile, vinyl acetate, maleic anhydride, maleic acid, and fumaric acid And the like.

One type of these maleimide polymer fine particles may be used alone, or two or more types may be used in combination. Among them, preferred are polymer fine particles of N-cyclohexylmaleimide and N-2-ethylhexylmaleimide, and copolymer fine particles of N-cyclohexylmaleimide and β-hydroxy-ethyl (meth) acrylate, and particularly preferred is polyurethane. It is a copolymer fine particle of N-cyclohexylmaleimide and β-hydroxy-ethyl (meth) acrylate because of its compatibility with the base resin powder.

The blending ratio of the maleimide polymer fine particles is in the range of 0.5 to 5% by weight based on the thermoplastic polyurethane resin powder. Above all, the range of 1 to 2% by weight is particularly preferable from the viewpoint of preventing the gloss of the skin material from occurring and maintaining the grain pattern.

If the blending ratio of the maleimide polymer fine particles is less than 0.5% by weight, it is impossible to prevent the gloss of the skin material from occurring and to maintain the grain pattern. If it exceeds 5% by weight, the meltability of the thermoplastic polyurethane-based resin powder decreases, and the slush moldability deteriorates, which is not preferable.

The particle size of the maleimide polymer particles is as follows:
It is in the range of 0.5 to 200 μm. Above all, 100-15
The range of 0 μm is particularly preferable from the viewpoint of fluidity (powder flowability) of a resin composition mainly used for thermoplastic slush molding and used for powder slush molding.

The maleimide polymer fine particles have a particle size of 0.5.
If it is less than 5 μm, the fluidity (powder flowability) of the resin composition used for powder slush molding is impaired. 200μ
If it exceeds m, white spots are left on the surface of the skin material to cause poor appearance, gloss is not generated, and a grain pattern cannot be maintained, which is not preferable.

The shape of the fine particles is not particularly limited, but is preferably spherical or nearly spherical in view of the flowability of the material during molding.

The molecular weight of the maleimide polymer fine particles is in the range of 2,000 to 100,000 as the number average molecular weight. Above all, a range of 10,000 to 50,000 is particularly preferable from the viewpoint of heat resistance.

If the number average molecular weight of the maleimide polymer particles is less than 2,000, the particles are thermally melted at the temperature at the time of slush molding, so that the surface material cannot be glossy and a grain pattern cannot be maintained. If it exceeds 100,000, the meltability of the thermoplastic polyurethane-based resin powder decreases, and the slush moldability deteriorates, which is not preferable.

As examples of the maleimide polymer fine particles used in the present invention, those described in JP-A-3-244607 can be effectively used.

Specific examples of the thermoplastic polyurethane resin powder used in the present invention include those having a particle size of 30 to 40 ° C., which can be melted at 200 to 240 ° C., produced by a suspension polymerization method, a bulk polymerization method, or an emulsion polymerization method. Thermoplastic polyurethane resin powder in the range of 300 μm is exemplified.

In addition to the above-mentioned components, the powdery resin composition for slush molding of the present invention may be used in any other known range as long as it does not impair the glossiness of the skin material and retains the grain pattern, which is an effect unique to the present invention. Conventional pigments, inorganic fillers, plasticizers, release agents, organic fillers, dispersants, ultraviolet absorbers (light stabilizers),
Antioxidants and the like can be added.

As a method of mixing the slush molding powder resin composition of the present invention, a method of dry blending using a high-speed rotary mixer is well known.

[0038]

The present invention will be described more specifically with reference to the following examples and comparative examples. In the examples, all parts are by weight unless otherwise specified.

Example 1 A thermoplastic polyurethane resin powder having a particle size in the range of 30 to 300 μm produced by a suspension polymerization method in a Henschel mixer having an internal volume of 10 L (Dainippon Ink Chemical Industry Co., Ltd.)
3 kg), and a plasticizer (Sekisui Chemical Co., Ltd .:
330 g of a blue pigment paste (pigment content: 10%) dispersed in isodecyl phthalate) and 15 g of zinc stearate as a release agent were dry-blended at a constant rotation speed. 90
Leave for 20 minutes with low-speed stirring at １００100 ° C .;
After cooling to a temperature of 0 ° C. or less, N-cyclohexylmaleimide polymer fine particle powder having a number average molecular weight of 15,000 and a particle size of 100 to 150 μm (Nippon Oil & Fats Co., Ltd.)
(Noflex MP-200) was dry-blended at a constant rotational speed to obtain a powder resin composition for slush molding.

Example 2 Gray pigment paste (pigment content: 10%) previously dispersed in a plasticizer (manufactured by Sekisui Chemical Co., Ltd .: diundecyl phthalate)
500 g, maleimide polymer fine particle powder as an auxiliary agent,
Number average molecular weight 20,000, particle size 100-130 μm
A powder resin composition for slush molding was obtained in the same manner as in Example 1, except that 90 g of N-cyclohexylmaleimide and 60 g of a copolymer fine particle powder of 10 g of β-hydroxyethyl (meth) acrylate were used.

Example 3 Blue pigment paste (pigment content: 10%) previously dispersed in a plasticizer (manufactured by Sekisui Chemical Co., Ltd .: diisodecyl phthalate)
300 g, maleimide polymer fine particle powder as an auxiliary agent,
Number average molecular weight 20,000, particle size 100-130 μm
90 g of N-cyclohexylmaleimide and 10 g of β-hydroxyethyl (meth) acrylate (manufactured by NOF CORPORATION; Noflex MP-10)
H) Except for using 30 g, a powder resin composition for slush molding was obtained in the same manner as in Example 1.

Example 4 Gray pigment paste (pigment content: 10%) previously dispersed in a plasticizer (manufactured by Sekisui Chemical Co., Ltd .: diisononyl phthalate)
500 g, maleimide polymer fine particle powder as an auxiliary agent,
Number average molecular weight 20,000, particle size 100-130 μm
A powder resin composition for slush molding was obtained in the same manner as in Example 1, except that 90 g of N-cyclohexylmaleimide and 60 g of a copolymer fine particle powder of 10 g of β-hydroxyethyl (meth) acrylate were used.

Comparative Example 1 A thermoplastic polyurethane resin powder having a particle diameter in the range of 30 to 300 μm produced by a suspension polymerization method (Dainippon Ink Chemical Industry Co., Ltd.) was placed in a Henschel mixer having an internal volume of 10 L.
3 g), 400 g of a blue pigment paste (pigment content: 10%) previously dispersed in a plasticizer (manufactured by Sekisui Chemical Co., Ltd .: dioctyl phthalate), and 15 g of zinc stearate as a mold release agent at a constant speed. Dry blended at speed. The mixture was left for 20 minutes with low-speed stirring at 90 to 100 ° C., cooled to a temperature of 40 ° C. or less by water cooling, and then 3 g of silicon oxide (manufactured by Degussa; TS-100) was dry-blended at a constant rotation speed as a slush. A molding resin composition was obtained.

Comparative Example 2 60 g of a blue pigment powder (50% pigment content) previously dispersed in lead stearate, a maleimide polymer fine particle powder as an auxiliary, a number average molecular weight of 20,000, and a particle diameter of 100 to
90 g of 130 μm N-cyclohexylmaleimide;
A slush molding powder resin composition was obtained in the same manner as in Example 1, except that 60 g of copolymer fine particle powder of 10 g of β-hydroxyethyl (meth) acrylate was used.

Comparative Example 3 Plasticizer (isodecyl phthalate, manufactured by Sekisui Chemical Co., Ltd.)
Gray pigment paste (pigment content: 10%) dispersed in 30
Except for using g, a slush molding powder resin composition was obtained in the same manner as in Example 1.

Comparative Example 4 Plasticizer (isodecyl phthalate, manufactured by Sekisui Chemical Co., Ltd.)
Pigment paste (pigment content: 10%) dispersed in 80
0 g, a maleimide polymer fine particle powder as an auxiliary agent, N having a number average molecular weight of 20,000 and a particle diameter of 100 to 130 μm.
-A slush molding powder resin composition was obtained in the same manner as in Example 1, except that 90 g of cyclohexylmaleimide and 60 g of a copolymer fine particle powder of 10 g of β-hydroxyethyl (meth) acrylate were used.

Performance evaluation Preparation of skin: A slash molding powder resin composition was filled in a Ni electroform having a grain pattern preliminarily heated to 230 ° C., left for 2 minutes, and then the excess powder resin composition was discharged. 23
After heating at 0 ° C. for further 30 seconds and cooling with water, it was peeled off from the Ni electroforming mold to prepare a skin material having a thickness of about 1 mm.

The performance was evaluated by the following test. Table 1 shows the results. (1) Fluidity (powder flowability): A 220 cc glass bottle is half filled with powder and tilted at 45 °.
◎ ‥‥ Excellent ○ ‥‥ Good △ ‥‥ Slightly insufficient fluidity × ‥‥ Blocking is observed and defective

(2) Meltability: The smoothness and gloss of the back surface of the skin material were visually observed and evaluated according to the following four grades. ◎ ‥‥ Gloss and smoothness are sufficient ○ ‥‥ Smoothness but lack of gloss △ ‥‥ Glossy but lack of smoothness × ‥‥ Complete gloss The surface is rough

(3) Heat resistance: The skin material was left in a gear oven type heating furnace (manufactured by Satake Rika Chemical Machinery Co., Ltd.) at 110 ° C. for 100 hours, and the glossiness of the skin and the retention of the grain pattern were visually observed. And the following four grades. ◎ ‥‥ Gloss and grain pattern hardly changed ○ ‥‥ Gloss slightly increased, but grain pattern hardly changed △ ‥‥ Gloss increased considerably, skin material surface melted, grain The pattern is also considerably disappeared. × 認 め The skin material has melted and the grain pattern has completely disappeared.

(4) Uniformity of coloring: The uniformity of coloring on the surface of the skin material was visually observed and evaluated according to the following four grades. ◎ ‥‥ Very good ○ ‥‥ Good △ ‥‥ Some unevenness is observed × ‥‥ Unevenness is observed

[0052]

Industrial Applicability The resin composition of the present invention is excellent in uniformity of coloring, prevents generation of gloss over time on the surface of a matte skin material, can maintain a grain pattern, and is used for a thermoplastic polyurethane slush molding material. Useful as

[0053]

[Table 1]

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // (C08L 75/04 35:00) B29K 75:00 B29L 31:58

Claims (6)

[Claims] 1. A resin composition mainly composed of a thermoplastic polyurethane resin powder for use in powder slush molding or the like, in which a phthalic acid plasticizer converted into an alkyl ester having 9 to 12 carbon atoms is colored using a vehicle. A colored resin composition for powder molding, characterized by containing an agent. 2. A maleimide polymer fine particle powder in which a thermoplastic polyurethane resin powder and a coloring agent containing a phthalic acid plasticizer converted into an alkyl ester having 9 to 12 carbon atoms as a vehicle are added as required. The resin composition according to claim 1, wherein the resin composition is dry-blended together with an auxiliary. 3. The resin composition according to claim 1, wherein the phthalic acid-based plasticizer is contained in an amount of 1 to 20% by weight based on the thermoplastic urethane-based resin powder. 4. The resin composition according to claim 1, which is used for molding a molded article having a matte surface. 5. A resin molded article which is made of the resin composition according to claim 1 and has a matte pattern on its surface and is matte. 6. A paste comprising a coloring agent for a thermoplastic polyurethane resin powder used for powder slush molding or the like, which contains, as a vehicle, a dye and pigment and a phthalic acid plasticizer converted into an alkyl ester having 9 to 12 carbon atoms. Coloring agent.