JP3637694B2 - Powder molding resin composition and molded product - Google Patents

Description

【００４５】
【発明の効果】
本発明のマレイミド重合体微粒子粉末は、成形時の組成物の溶融性を損なうことなく、艶消し表皮材の表面における経時的な艶の発生を防止し、しぼ模様を保持出来、熱可塑性ポリウレタン系スラッシュ成形材料用として有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin composition for powder molding mainly composed of thermoplastic polyurethane resin powder, which suppresses surface gloss and is suitable as a molding material for automotive interior parts such as so-called matted instrument panels and door trims. About.
[0002]
[Prior art]
Conventionally, a vinyl chloride powder slush molded product is often used as a skin material for automotive interior parts such as instrument panels and door trims.
[0003]
However, when the vinyl chloride material is used for a long period of time, the plasticizer contained therein is transferred to the surface by heat, light, etc., and the soft feeling is impaired. In addition, it has been pointed out that the incinerator is corroded by hydrogen chloride gas generated during incineration after scrapping.
[0004]
In order to solve these problems, development of a powder slush molding material mainly composed of thermoplastic polyurethane resin powder has been underway. In the powder slush molding method, the powder is filled in a mold heated to 200 to 240 ° C., rotated to weld the powder to the inner surface of the mold, and the unwelded powder is discharged from the mold and collected to obtain a skin material. This is a method of molding.
[0005]
[Problems to be solved by the invention]
However, when the melting point of a thermoplastic polyurethane resin is adjusted so that powder slush molding can be performed, the skin surface changes over time due to heat (for example, heat received from direct sunlight in an automobile), and gloss is produced. This has the disadvantage that the wrinkle pattern that has been applied in order to apply the effect disappears. That is, even if a molded article to be obtained is provided with a matte surface and / or wrinkle pattern in advance, its durability over time is poor and the surface state cannot be sufficiently maintained.
[0006]
Under such circumstances, there is a strong demand for a modifier capable of preventing the occurrence of gloss without reducing moldability and maintaining a wrinkle pattern for a long period of time.
[0007]
Therefore, in order to obtain the thermoplastic polyurethane powder slush molding material that can prevent the gloss of the skin material without reducing such moldability and can retain the wrinkle pattern for a long period of time, a heat resistant resin powder that does not melt at the molding temperature is used. We have found that exploration is a problem that should be solved at present.
[0008]
[Means for Solving the Problems]
As a result of diligent research, the present inventor has produced a gloss of the skin material by blending a thermoplastic polyurethane powder resin composition with a maleimide polymer fine particle powder having a particle size of 0.5 to 200 μm that does not melt at the molding temperature. And the inventors have found that the wrinkle pattern can be retained for a long period of time, and have completed the present invention.
[0009]
That is, the present invention comprises a maleimide polymer fine particle powder having a particle size of 0.5 to 200 μm that does not melt at a molding temperature in a resin composition mainly composed of a thermoplastic polyurethane resin powder and used for powder slush molding or the like. Further, the present invention relates to a resin composition for powder molding, wherein the blending ratio is 0.5 to 5% by weight.
[0010]
The resin composition is preferably obtained by dry blending the thermoplastic polyurethane resin powder and the maleimide polymer fine particle powder together with a pigment for coloring and other additives as required.
[0011]
In the resin composition, the maleimide polymer fine particle powder is contained in an amount of 0.5 to 5% by weight based on the thermoplastic polyurethane resin powder, and the maleimide polymer has a number average molecular weight of 2,000 to 100. , 000, etc. are important.
[0012]
The resin molded product obtained by powder molding using the resin composition thus configured has a matte surface, and since the matte state retention durability is good, the present invention This relates to a molded product having the resin composition as a raw material and having a wrinkle pattern on the surface thereof, and also relates to the point that this composition was selected as a molding material for a resin molded product having a matte surface. is there.
[0013]
Such a molded article has good durability of the wrinkle pattern, and the matte surface of the wrinkle pattern gives the molded article a high-class feeling.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The typical and best modes of the embodiment of the present invention are specifically shown in the examples described later. Each component that can be selected for carrying out the present invention will be described in detail.
[0015]
Specific examples of the maleimide polymer fine particle powder used in the present invention include N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, Nn-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, N -Cyclohexyl maleimide, N-2-ethylhexyl maleimide, N-decyl maleimide, N-dodecyl maleimide, N-octadecyl maleimide, N-cyclododecyl maleimide, N-phenyl maleimide, N-0-methylphenyl maleimide, N-benzyl maleimide, Examples thereof include those obtained by polymerizing maleimide compounds such as N-phenyl-2-chloromaleimide and N-benzyl-2-methylmaleimide in the presence of a radical generator in an alcohol-based non-aqueous solvent.
[0016]
Also, other monomers having copolymerizability with the maleimide compound can be copolymerized within a range not exceeding 20% by weight.
[0017]
When the other monomer exceeds 20% by weight, the heat resistance of the obtained maleimide polymer fine particle powder is impaired, which is not preferable.
[0018]
Specific examples of other monomers include styrene monomers such as styrene and α-methylstyrene, (meth) acrylic such as methyl (meth) acrylate, butyl (meth) acrylate, and β-hydroxyethyl (meth) acrylate. Examples include acid esters, (meth) acrylonitrile, vinyl acetate, maleic anhydride, maleic acid, and alkyl esters of fumaric acid.
[0019]
These maleimide polymer fine particles may be used alone or in a combination of two or more. Among them, preferred are N-cyclohexylmaleimide, N-2-ethylhexylmaleimide polymer fine particles, and N-cyclohexylmaleimide and β-hydroxy-ethyl (meth) acrylate copolymer fine particles, 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 system resin powder.
[0020]
The blending ratio of the maleimide polymer fine particles is in the range of 0.5 to 5% by weight with respect to the thermoplastic polyurethane resin powder. Among these, the range of 1 to 2% by weight is particularly preferable from the viewpoint of preventing the gloss of the skin material and maintaining the texture.
[0021]
If the blending ratio of the maleimide polymer fine particles is less than 0.5% by weight, it is impossible to prevent the luster of the skin material and keep the texture. If it exceeds 5% by weight, the meltability of the thermoplastic polyurethane resin powder is lowered, and the slush moldability is deteriorated.
[0022]
The particle size of the maleimide polymer fine particles is in the range of 0.5 to 200 μm. Among these, the range of 100 to 150 μm is particularly preferable from the viewpoint of the fluidity (powder flowability) of a resin composition for use in powder slush molding mainly composed of thermoplastic polyurethane resin powder.
[0023]
If the particle size of the maleimide polymer fine particles is less than 0.5 μm, the fluidity (powder flowability) of the resin composition for use in powder slush molding is impaired. If it exceeds 200 μm, the surface of the skin material will remain as white spots, resulting in poor appearance, and it will not be possible to prevent the occurrence of gloss and to keep the pattern, which is not preferable.
[0024]
The shape of the fine particles is not particularly limited, but is preferably spherical or close to that in view of the flowability of the material during molding.
[0025]
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. Among these, the range of 10,000 to 50,000 is particularly preferable from the viewpoint of heat resistance.
[0026]
If the number average molecular weight of the maleimide polymer fine particles is less than 2,000, it will melt at the temperature at the time of slush molding, and it will not be possible to prevent the luster of the skin material from being retained. If it exceeds 100,000, the meltability of the thermoplastic polyurethane resin powder is lowered, and the slush moldability is deteriorated.
[0027]
As examples of the maleimide polymer fine particles used in the present invention, those described in JP-A-3-244607 can be used effectively.
[0028]
Specific examples of the thermoplastic polyurethane resin powder used in the present invention include a suspension polymerization method, a bulk polymerization method, and an emulsion polymerization method, and a particle size that can be melted at 200 to 240 ° C. is in the range of 30 to 300 μm. The thermoplastic polyurethane resin powder in the above.
[0029]
In addition to the above-mentioned components, the slush molding powder resin composition of the present invention includes known and commonly used pigments as long as the gloss of the skin material, which is an effect peculiar to the present invention, is prevented and the retention of the texture is not impaired. Inorganic fillers, plasticizers, mold release agents, organic fillers, dispersants, ultraviolet absorbers (light stabilizers), antioxidants, and the like can be added.
[0030]
As a method of mixing the powder resin composition for slush molding of the present invention, a method of dry blending using a high-speed rotary mixer is well known.
[0031]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.
In the examples, unless otherwise specified, all parts represent parts by weight.
[0032]
Example 1
A Henschel mixer with an internal volume of 10 l is charged with 3 kg of a thermoplastic polyurethane resin powder (manufactured by Dainippon Ink & Chemicals, Inc.) having a particle size in the range of 30 to 300 μm produced by suspension polymerization. 120 g of a blue pigment paste (pigment content 50%) dispersed in DIDP) and 15 g of zinc stearate as a release agent were dry blended at a constant rotational speed.
The mixture is allowed to stand for 20 minutes with low-speed stirring at 90 to 100 ° C., cooled to a temperature of 40 ° C. or less with water, and then 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 Yushi) 20 g of Noflex MP-200 (manufactured by Co., Ltd.) was dry blended at a constant rotational speed to obtain a powder resin composition for slush molding.
[0033]
Example 2
Powder resin composition for slush molding in the same manner as in Example 1 except that 15 g of N-cyclohexylmaleimide polymer fine particle powder (manufactured by NOF Corporation) having a number average molecular weight of 15,000 and a particle size of 100 to 150 μm was used. I got a thing.
[0034]
Example 3
Maleimide polymer fine particle powder is 90 g of N-cyclohexylmaleimide having a number average molecular weight of 20,000 and a particle size of 100 to 130 μm, and 10 g of β-hydroxyethyl (meth) acrylate (manufactured by NOF Corporation). ; Noflex MP-10H) A powder resin composition for slush molding was obtained in the same manner as in Example 1 except that 30 g was used.
[0035]
Example 4
100 g of a gray pigment paste (pigment content: 60%) dispersed in a plasticizer (DUP) in advance, 90 g of N-cyclohexylmaleimide having a number average molecular weight of 20,000 and a particle size of 100 to 130 μm, and β A powder resin composition for slush molding was obtained in the same manner as in Example 1 except that 60 g of copolymer fine particle powder of 10 g of hydroxyethyl (meth) acrylate was used.
[0036]
Comparative Example 1
Into a Henschel mixer with an internal volume of 10 l, 3 kg of a thermoplastic polyurethane resin powder (manufactured by Dainippon Ink Chemical Co., Ltd .; Pandex) having a particle size of 30 to 300 μm made by suspension polymerization is charged. 120 g of a blue pigment paste (pigment content 50%) previously dispersed in a plasticizer (DIDP) and 15 g of zinc stearate as a release agent were dry blended at a constant rotational speed.
After standing at 90-100 ° C. for 20 minutes while stirring at low speed, after cooling to 40 ° C. or less with water cooling, 3 g of silicon oxide (Degussa; TS-100) is dry blended at a constant rotational speed and powder resin for slush molding A composition was obtained.
[0037]
Comparative Example 2
A powder resin composition for slush molding was obtained in the same manner as in Comparative Example 1 except that 15 g of benzoguanamine resin powder (manufactured by Nippon Shokubai Kogyo Co., Ltd .; Eposter S) was used instead of silicon oxide.
[0038]
Comparative Example 3
A powder resin composition for slush molding was obtained in the same manner as in Comparative Example 1 except that 25 g of charcoal cal (manufactured by Nitto Flour Chemical Co., Ltd .; NS-200) was used instead of silicon oxide.
[0039]
Comparative Example 4
Into a Henschel mixer with an internal volume of 10 l, 3 kg of a thermoplastic polyurethane resin powder (manufactured by Dainippon Ink Chemical Co., Ltd .; Pandex) having a particle size of 30 to 300 μm made by suspension polymerization is charged. 120 g of a blue pigment paste (pigment content 50%) previously dispersed in a plasticizer (DIDP) and 15 g of zinc stearate as a release agent were dry blended at a constant rotational speed.
The mixture was allowed to stand for 20 minutes at 90 to 100 ° C. with low speed stirring, and cooled to a temperature of 40 ° C. or less with water cooling to obtain a slush molding powder resin composition.
[0040]
Preparation of performance evaluation skin: Fill a Ni electromold with a wrinkle pattern preheated to 230 ° C. with a powder resin composition for slush molding, and after leaving for 2 minutes, discharge the excess powder resin composition. After further heating at 230 ° C. for 30 seconds and water cooling, it was peeled off from the Ni electroforming mold to prepare a skin material having a thickness of about 1 mm.
[0041]
The performance was evaluated by the following test. The results are shown in Table 1.
(1) Fluidity (powder flowability): The 220CC glass bottle was half filled with the powder and tilted to 45 °, and the powder flow was evaluated in the following three stages. ............ Block is recognized and defective [0042]
(2) Meltability: The smoothness and glossiness of the back surface of the skin material were visually observed and evaluated in the following four stages.
◎ …… Gloss and smoothness are sufficient.
○ …… Smooth, but lacks gloss.
Δ: Glossy but not smooth.
× …… It is completely glossy and the surface is rough.
[0043]
(3) Heat resistance: Leave the skin material for 100 hours in a gear oven type heating furnace (Satake Rika Chemical Machinery Co., Ltd.) in an atmosphere of 110 ° C., and visually observe the gloss and texture of the skin. Evaluation was made in 4 stages.
◎ …… There is almost no change in gloss and wrinkle pattern.
○ The gloss is slightly increased, but almost no change is observed in the wrinkle pattern. Δ The gloss is considerably increased, the surface of the skin material is melted, and the wrinkle pattern is considerably lost.
× The skin material melts and the wrinkle pattern disappears completely.
[0044]
[Table 1]

[0045]
【The invention's effect】
The maleimide polymer fine particle powder of the present invention can prevent generation of gloss over time on the surface of a matte skin material without impairing the meltability of the composition at the time of molding, and can retain a wrinkle pattern, and is a thermoplastic polyurethane system. Useful for slush molding materials.

Claims (6)

A resin composition mainly composed of a thermoplastic polyurethane resin powder and used for powder slush molding or the like, comprising maleimide polymer fine particle powder having a particle size of 0.5 to 200 μm which does not melt at a molding temperature. A resin composition for powder molding. The resin composition according to claim 1, wherein the thermoplastic polyurethane resin powder and the maleimide polymer fine particle powder are dry blended . The resin composition according to claim 1 or 2, wherein the maleimide polymer fine particle powder is contained in an amount of 0.5 to 5% by weight based on the thermoplastic polyurethane resin powder. The resin composition according to claim 1, 2 or 3, wherein the maleimide polymer has a number average molecular weight of 2,000 to 100,000 and does not melt at a molding temperature. The resin composition according to any one of claims 1 to 4, which is used for molding a molded article having a matte surface. A resin molded product characterized in that the resin composition according to any one of claims 1 to 4 is used as a raw material, has a mottled pattern on the surface, and is matted.