JP2002363417A - Thermoplastic elastomer composition powder for powder molding and surface skin body powder-molded by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a thermoplastic elastomer composition powder which is excellent in sheet molding property and inexpensive and to provide a surface skin body having high physical properties, not causing whitening when folded, excellent in flexibility and having good surface appearance. SOLUTION: The thermoplastic elastomer composition powder is obtained by mixing a powder composition having 300-1,000 μm primary particle diameter with a powder composition having 50-200 μm primary particle diameter at a weight ratio of 50:50 to 95:5. The elastomer composition powder is used for powder molding. An olefin-based (TPO) or polyurethane-based (TPU) thermoplastic elastomer is preferably used as the thermoplastic elastomer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition powder used for powder molding, and more particularly, to a powder composition having a primary particle size of 300 to 1000 .mu.m, and a powder having a primary particle size of 50 to 200 .mu.m. TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition powder obtained by mixing a body composition at a specific mass ratio and a skin formed by powder molding using the same.

[0002]

2. Description of the Related Art As a powder molding method using a soft powder material, a powder slush molding method using a soft vinyl chloride resin powder is used for an instrument panel, a console box,
Widely used for the skin of car interior parts such as door trim. This is a soft touch, and can be provided with leather grain and stitches, and has good design properties such as a large degree of freedom in design.

[0003] Unlike other molding methods such as injection molding and compression molding, this molding method does not apply a shaping pressure. Therefore, in order to uniformly adhere a powder material to a mold having a complicated shape at the time of molding, powder molding is performed. It is necessary to have excellent body fluidity, and the powder attached to the mold melts and flows even under no pressure to form a film. It has become. In addition, it was necessary that the skin formed by cooling the mold could be released more easily than the mold.

As one method for improving this, Japanese Patent Application Laid-Open No. 7-82433 discloses that a polypropylene resin and a specific styrene-based thermoplastic elastomer have a mass ratio of 70/3.
It has been proposed to pulverize and use a mixture of 0 to 30/70. Here, the styrene-based thermoplastic elastomer is a styrene / ethylene / butylene / styrene block copolymer having a styrene content of 20% by mass or less, a styrene / ethylene propylene / styrene block copolymer having a styrene content of 20% by mass or less, and a styrene content of 2% or less.
It is selected from hydrogenated styrene-butadiene rubber of 0% by mass or less, and has a good compatibility with a polypropylene resin and is a composition suitable for powder molding.

[0005]

However, in general, the thermoplastic elastomer composition powder used in the powder molding method under no pressure should have a primary particle size of 300 μm or less to ensure the melt flowability. Needed for
Powders exceeding this primary particle size have insufficient melt fluidity, failing to provide a good surface skin, and pinhole defects due to insufficient powder fusion have been observed on the surface of the compact. did. As a method of eliminating the pinhole phenomenon, there is a method of improving the melt fluidity by lowering the molecular weight of the thermoplastic elastomer composition, but the lower molecular weight lowers various physical properties of the molded product, and the physical properties required for the skin are reduced. There is a problem that strength cannot be obtained. There is also a method of increasing the temperature of a molding die, but this is not preferable because the thermoplastic elastomer composition thermally deteriorates during molding.

[0006] For the above reasons, in the prior art, there is no other method than the sole use of a thermoplastic elastomer composition powder having a primary particle size of 300 µm or less to obtain a skin having desired physical properties. Was. However, as a method for producing a powder composition having a primary particle size of 300 μm or less, after preparing a pellet composition of several mm,
Generally, this is pulverized to 300 μm or less by freeze pulverization or the like, and this pulverization requires high cost. Development of things was desired.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and is an inexpensive powdery thermoplastic elastomer composition for powder molding excellent in sheet moldability, and a skin molded by using the same. It is an object of the present invention to provide a body, specifically, a skin body having high physical properties, without bending and whitening, and having no pinholes and excellent flexibility. Note that the above publication does not describe the correlation between the primary particle size of the powder and the surface properties of the compact, and the present applicant has made extensive studies and found the present invention.

[0008]

That is, according to the first aspect of the present invention, there is provided a thermoplastic elastomer composition powder used for powder molding, which has a primary particle size of 300 to 1000 μm.
The following powder composition and a primary particle size of 50 to 200 μm
A thermoplastic elastomer composition powder for powder molding, characterized in that the following powder compositions are mixed at a mass ratio of 50:50 to 95: 5. When a powder composition having a primary particle size of 300 μm or more is used alone as a powder molding material, the pinhole phenomenon on the surface cannot be avoided, but the primary particle size is 200 μm.
When a powder composition of the powder composition having a particle size of 200 μm or less is used as the molding material, the powder composition having a particle size of 300 μm or less is filled with the powder composition having a particle size of 200 μm or less. Since the powder uniformly adheres to the surface of the mold, the gap between the powders adhered to the mold surface is equivalent to the case where the powder composition of 300 μm or less adheres to the surface of the mold alone, and a pin is formed on the surface of the molded body. It is possible to obtain a molded article having excellent design without a hole defect. Moreover, since 50% by mass or more of the thermoplastic elastomer composition powder is composed of a relatively low-cost powder composition having a primary particle size of 300 μm or more, it is necessary to use a low-cost and low-molecular-weight material. Therefore, it is possible to produce a skin body having high physical properties and excellent flexibility without bending and whitening.

According to the invention of claim 2 of the present application, the thermoplastic elastomer composition is a composition mainly composed of an olefin-based thermoplastic elastomer, and the obtained composition has a melt flow rate (MFR). , JIS K72
The thermoplastic elastomer composition powder for powder molding according to claim 1, which is measured at a temperature of 230 ° C. and a load of 2.16 kgf in accordance with 10 and is 10 g / 10 min or more. By using a polyolefin-based composition that is easy to use for recycling, the configuration is environmentally friendly.

In the invention according to claim 3 of the present application, the copolymer of a vinyl aromatic hydrocarbon compound monomer and a conjugated diene monomer is added to 100 parts by mass of a polypropylene resin. A composition containing at least 90 to 500 parts by mass of a hydrogenated copolymer which is hydrogenated by 90% or more and in which the proportion of the vinyl aromatic hydrocarbon compound in the hydrogenated copolymer is 5 to 25% by mass; 3. The thermoplastic elastomer composition powder for powder molding according to claim 2, wherein the powder molding is excellent in sheet moldability by blending a polypropylene resin and a hydrogenated copolymer having good compatibility with the polypropylene resin. Thermoplastic elastomer composition powder.

In the invention according to claim 4, the hydrogenated copolymer according to claim 3 is a random copolymer of styrene and butadiene, a random copolymer of styrene and isoprene,
A block copolymer of styrene and butadiene having an average of 1.2 bonds of butadiene block before hydrogenation of 6
At least one selected from a copolymer having 2 mol% or more and a copolymer having an average of 1.2 bonds of isoprene blocks of 62 mol% or more before hydrogenation in a block copolymer of styrene and isoprene; A thermoplastic elastomer composition powder for powder molding, which has a higher degree of compatibility with a polypropylene resin by specifying a hydrogenated copolymer, and is finely dispersed in the order of several tens of nanometers. And good sheet formability.

In the invention according to claim 5 of the present application, the ethylene / α-olefin copolymer rubber is used as a hydrogenated copolymer 1
4. The composition according to claim 3, wherein the content is 5 to 250 parts by mass with respect to 00 parts by mass.
Or the thermoplastic elastomer composition powder for powder molding according to any one of 4 to 4, wherein the MFR of the composition is large and the moldability of the powder molding is good.

In the invention according to claim 6 of the present application, the organic peroxide is added in an amount of 0.0
The thermoplastic elastomer composition powder for powder molding according to any one of claims 3 to 5, which is blended in an amount of 2 to 5.0 parts by mass, wherein the composition has a large MFR and good powder moldability. Become.

According to a seventh aspect of the present invention, there is provided the thermoplastic elastomer composition powder for powder molding according to any one of the second to sixth aspects, further comprising a process oil.
The FR is large, and the moldability of powder molding becomes good.

In the invention according to claim 8 of the present application, the thermoplastic elastomer composition is a composition mainly composed of thermoplastic polyurethane, and the obtained composition has a melt flow rate (MFR) of JIS K7210. The thermoplastic elastomer composition powder for powder molding according to claim 1, which is measured at a temperature of 230 ° C and a load of 2.16 kgf in accordance with the above, and has a flexibility of 10 g / 10 min or more. As a result, a skin with good touch and good scratch resistance can be obtained.

According to the ninth aspect of the present invention, the thermoplastic polyurethane is a thermoplastic polyurethane comprising at least one selected from the group consisting of polyester diol and polyether diol, and an aliphatic diisocyanate or an alicyclic diisocyanate. The thermoplastic elastomer composition powder for powder molding according to claim 8, wherein the number average molecular weight is at least 10,000 and less than 100,000, which is synthesized from a diisocyanate selected from at least one type of naat. Thus, an epidermis having good weather resistance and less discoloration can be obtained.

According to a tenth aspect of the present invention, there is provided a skin formed by powder using the thermoplastic elastomer composition powder for powder molding according to any one of the first to ninth aspects, wherein A product having the same moldability and skin quality as those obtained by molding using a powder of 300 μm or less alone can be produced at lower cost.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermoplastic elastomer used in the present invention includes thermoplastic elastomers such as olefin (TPO), polyurethane (TPU), styrene, polyester, polyamide and polyvinyl chloride. However, TPO or TPU is preferred because of its flexibility as the skin material and ease of recycling.

As the TPO material, for example, an elastomer composition obtained by blending or alloying an elastomer component with a polypropylene resin to have flexibility is exemplified. The polypropylene resin may be a homopolymer, a block copolymer with an α-olefin, or any of random copolymers.
Examples thereof include butylene, pentene and octene, and ethylene is particularly preferred from the viewpoint of price. Further, in order to use the powder slush molding without applying pressure, an MFR measured at 230 ° C. and a load of 2.16 kgf according to JIS K7210 as an index of melt fluidity is 100 g.
/ 10 min or more, more preferably 100 to 800 g / 10
It is desirable to use a polypropylene resin which is a sufficient amount.

When a polypropylene resin having an MFR of less than 100 g / 10 minutes and lacking in melt fluidity is used, an organic peroxide is used in an amount of 0.02 to 5.0 parts by mass based on 100 parts by mass of the polypropylene resin. Blended, 120-2
Knead at a temperature of 50 ° C. to obtain an MFR of 100 to 800 g /
It is possible to reduce the molecular weight of the polypropylene resin so that it takes 10 minutes.

Further, it is preferable that after the organic peroxide is added to the polypropylene resin and melt-kneaded, an elastomer component such as a hydrogenated copolymer is melt-kneaded. When melt-kneading the elastomer component and the organic peroxide at the same time,
The elastomer has a low molecular weight and migrates to the surface of the molded sheet.After heat aging, the surface becomes tacky or glossy. In some cases, the moldability is deteriorated.

As the above-mentioned organic peroxide, usually, rubber,
Diacyl peroxide used for crosslinking of resin,
Peroxyester, diallyl peroxide, di-t
-Butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, 2,5-dimethyl-
2,5-di (t-butylperoxy) -hexane-3,
1,3-bis (t-butylperoxy-isopropyl)
Benzene, 1,1-di-butylperoxy-3,3,5
-Trimethylcyclohexane and the like;
Those having a half-life of 150 to 250 ° C. per minute are preferred.

The hydrogenated copolymer used in the present invention has excellent compatibility with the polypropylene resin, and is finely dispersed uniformly when kneaded and mixed. A composition is obtained.

As the hydrogenated copolymer, a copolymer of a vinyl aromatic hydrocarbon compound monomer and a conjugated diene monomer is hydrogenated by 90% or more, and a hydrogenated copolymer of a vinyl aromatic hydrocarbon compound is hydrogenated. 5-25 in the polymer
There is wt% polymer.

Examples of the vinyl aromatic hydrocarbon compound monomer include alkyl styrene such as styrene, α-methyl styrene, p-methyl styrene and p-tert-butyl styrene, paramethoxy styrene, vinyl naphthalene and the like. Species, or selected from two or more, among which styrene is preferred, and the hydrogenated copolymer is a random copolymer of styrene and butadiene, a random copolymer of styrene and isoprene, and a block copolymer of styrene and butadiene. Copolymers having an average of 1.2 bonds of butadiene blocks before hydrogenation of at least 62 mol% can be mentioned, and the ratio of the vinyl aromatic hydrocarbon compound in the hydrogenated copolymer is 5 to 5. 25% by mass. In order to obtain a skin having good moldability and high flexibility, 5%
-15% by mass is appropriate.

The hydrogenated copolymer used in the present invention is, specifically, a random copolymer of styrene and butadiene. The one having a styrene content of 10% and a hydrogenation rate of 90% or more is manufactured by JSR Corporation. Dynalon 1320P, 23
20P, a typical block copolymer of styrene and butadiene having an average of 1,2 bond amount of at least 62 mol% of a block mainly composed of a butadiene monomer unit before hydrogenation is at least 62 mol%. There is a product made by Asahi Kasei Corporation, Tuftec L-515. These hydrogenated copolymers are excellent in compatibility with a polymer mainly composed of polypropylene, so that they are finely dispersed, are excellent in powder molding, and have characteristics such that a molded sheet is not whitened when folded.

The blending amount of the polypropylene resin and the hydrogenated copolymer is 20 to 500 parts by mass with respect to 100 parts by mass of the polypropylene resin. When the amount of the polypropylene resin exceeds the above range, the molded skin becomes hard, On the other hand, when it decreases, the tensile strength decreases.

The hydrogenated copolymer used in the present invention has very good compatibility with the polypropylene resin, and the hydrogenated copolymer is finely dispersed with a particle diameter of 15 to 20 nm in the polypropylene resin. Has been confirmed by a transmission electron microscope. Uniform fine dispersion of the polypropylene resin and the hydrogenated copolymer improves the moldability, enhances the physical properties, is flexible and does not whiten when folded, and is a thermoplastic elastomer composition and skin for powder molding. The body is obtained.

In the present invention, the addition of the process oil has the effect of being absorbed by the elastomer component in the composition and lowering the melt viscosity, lowering the hardness of the skin body, and having flexibility. The above process oils are used for rubber and are classified into paraffinic, naphthenic, and aroma-based oils. Among them, paraffin-based oils having good compatibility with elastomer components are preferred. The addition amount is preferably from 5 to 200 parts by mass based on 100 parts by mass of the hydrogenated copolymer. If it exceeds 200 parts by mass, the tensile properties decrease,
When the amount is less than 5 parts by mass, the melt viscosity does not decrease and the skin becomes hard.

The ethylene / α-olefin-based copolymer rubber is an elastomer having excellent oil absorbing ability, and its compatibility with the polypropylene resin is improved by blending it with the hydrogenated copolymer. Further, it has a property of absorbing the process oil and the oligomer component in the composition, and is at least one selected from non-crystalline ethylene / α-olefin copolymers. Preferred α-olefins include α-olefins having 3 to 10 carbon atoms such as propylene, 1-butene and 1-octene.
Among them, ethylene propylene rubber (EPR) and ethylene / octene copolymer (EOR) are preferable.

The above ethylene / α-olefin copolymer rubber is inferior in compatibility with the polypropylene resin as compared with the hydrogenated copolymer used in the present invention. However, since the elastomer has excellent oil-absorbing ability, it can absorb the oligomer component and oil in the composition and can considerably prevent bleeding.

The amount of the ethylene / α-olefin copolymer rubber to be added is 5 to 250 parts by mass based on 100 parts by mass of the hydrogenated copolymer. When the amount is less than 5 parts by mass, the oligomer component and oil in the composition cannot be sufficiently absorbed, and when it exceeds 250 parts by mass, propylene-α-
Dispersion with the olefin copolymer tends to be poor, and tensile properties tend to decrease.

As the heat stabilizer, those used for ordinary polyolefins can be used. Generally, phenol and a phosphorus-based antioxidant are used in combination, but are not particularly limited. As the light stabilizer, a hindered amine or benzotriazole type radical scavenger may be used. Organic and inorganic pigments suitable for ordinary olefins are used. Further, a lubricant such as a fatty acid metal salt and a filler such as calcium carbonate and talc are added as required.

These TPO compositions are prepared by melt-kneading according to the following six methods. (1) A method in which a hydrogenated copolymer is simultaneously added to a polypropylene resin having an MFR of 100 to 800 g / 10 min and kneaded at a temperature of 120 to 250 ° C. In this case, an organic peroxide is used. Is not added.

(2) A hydrogenated copolymer, an ethylene / α-olefin copolymer rubber and the like are simultaneously added to a polypropylene resin having an MFR of 100 to 800 g / 10 minutes, and these are heated at a temperature of 120 to 250 ° C. In this case, no organic peroxide is added. (3) Hydrogenated copolymer, process oil, ethylene / α-olefin-based copolymer rubber, etc. are simultaneously added to a polypropylene resin having an MFR of 100 to 800 g / 10 minutes, and these are heated to a temperature of 120 to 250 ° C. In this case, no organic peroxide is added. (4) 0.02 to 5.0 parts by mass of an organic peroxide is added to a polypropylene resin having an MFR of less than 100 g / 10 minutes in advance, and the mixture is kneaded at a temperature of 120 to 250 ° C. to reduce the MFR to 10%.
There is a method in which a hydrogenated copolymer, an ethylene / α-olefin-based copolymer rubber and the like are simultaneously added to a propylene resin adjusted to 0 to 800 g / 10 minutes, and these are kneaded at a temperature of 120 to 250 ° C. .

(5) To a polypropylene resin having an MFR of less than 100 g / 10 minutes and an ethylene / α-olefin copolymer rubber, 0.02 to 5.0 parts by mass of an organic peroxide is added, and After the kneading at a temperature of 120 ° C., a hydrogenated copolymer is further added thereto, and the mixture is kneaded at a temperature of 120 to 250 ° C.

(6) 0.02-5.0 parts by mass of a polypropylene resin having an MFR of less than 100 g / 10 minutes, an ethylene / α-olefin-based copolymer rubber and an organic peroxide are added at 120-250 ° C. After kneading at a temperature of 120 ° C., a process oil and a hydrogenated copolymer
By a method of kneading at a temperature of up to 250 ° C., kneading may be carried out twice in a sequential manner, or kneading may be performed in one pass using a vent port.

The additive kneading method is as follows.
Dry blended using a tumbler, Henschel mixer, etc., is supplied from a raw material supply hopper, process oil is injected from a vent port, and melt-kneaded with a twin-screw extruder adjusted to a temperature in a range of 120 to 250 ° C. to form a pellet. Become

Further, a process oil was added to the hydrogenated copolymer and the ethylene / α-olefin copolymer rubber as the elastomer components by means of a kneader or a Banbury mixer as an internal mixer, and the mixture was kneaded and pelletized. Thereafter, after the pellets and the polypropylene resin are dry-blended, the pellets can be charged into a single-screw or twin-screw extruder whose temperature has been adjusted to a range of 120 to 250 ° C. and melt-kneaded into pellets.

MFR which is the melt viscosity of the obtained pellet
Is 10 at a temperature of 230 ° C and a load of 2.16 kgf.
g / 10 min or more, more preferably 40 to 800 g / 10
It is preferable to have a melt fluidity of the order of 1 minute. If it is less than this, the melt fluidity of the composition tends to be low, and pinholes tend to occur in the skin.

Further, a thermoplastic polyurethane (TPU) usable as a main material of the thermoplastic elastomer composition powder
Is a polymer obtained by reacting a high molecular weight diol such as a polyester diol or a polyether diol with a low molecular weight diol as a chain extender with a diisocyanate compound. And isocyanate groups in substantially equal amounts. For powder molding, the melt flow rate (MFR) was measured at a temperature of 230 ° C. and a load of 2.16 kgf in accordance with JIS K7210, and was 10 g / 10 min or more, and was measured by liquid chromatography (GPC). The measured number average molecular weight in terms of styrene is preferably 10,000 or more and less than 100,000.

The polyester diols of high molecular weight diols include diols obtained by ring-opening polymerization of ε-caprolactone, diols obtained by condensing adipic acid and 1.4 butanediol, and diols obtained by condensing terephthalic acid with 1.4.
Examples thereof include diols obtained by condensing butanediol. Also, as polyether diol,
Examples include polypropylene glycol obtained by ring-opening polymerization of polypropylene oxide, and polyethylene glycol obtained by ring-opening polymerization of ethylene oxide. These high molecular weight diols can be used alone or in combination of two or more in order to obtain the flexibility and physical strength required for the powder molded skin. Examples of the low molecular weight diol used as a chain extender include ethylene glycol and 1,4-butanediol.

As the diisocyanate compound, a diisocyanate compound having an aromatic ring such as tolylene diisocyanate or diphenylmethane diisocyanate can be used. However, in order to improve the weather resistance of the molded skin and eliminate discoloration with time, hexamethylene diisocyanate, hydrogenated triisocyanate, etc. It is preferable to use diisocyanates having a saturated hydrocarbon skeleton such as diisocyanate and hydrogenated diphenylmethane diisocyanate.

As a method for synthesizing a polyurethane, a prepolymer in which a diisocyanate is added to both terminal hydroxyl groups of a high molecular weight diol in advance and a low molecular weight diol is added to the prepolymer to extend the chain, There is a method in which components are simultaneously charged and reacted. In order to make the reaction uniform, a method of using an organic medium and removing it after completion of the reaction, or a tin-based or tertiary amine which promotes the reaction can be used.

The thermoplastic elastomer composition may be formed into a powder having a primary particle size of 300 to 1000 μm by pulverization at room temperature with an impact pulverizer, pulverization at room temperature with a grinder pulverizer, or a hole extruder at a screw extruder. Micro-pelletization using a hot-cut pelletizer equipped with a die having a diameter of 200 to 400 μm and a number of holes of 100 to 700 can be mentioned, and the cost of powdering is inexpensive.

In the use of a hot cut pelletizer, a method of cutting in water is preferable to a method of cutting in air in order to eliminate mutual adhesion of the cut molten elastomer.

As a method for obtaining a thermoplastic elastomer composition powder having a primary particle size of 50 to 200 μm, a freeze-pulverization method of freezing with liquid nitrogen or the like and pulverizing with a pulverizer, or spraying a molten thermoplastic elastomer is used. Cooling and solidification, a method in which a thermoplastic elastomer dissolved in a good solvent is injected into a poor solvent and precipitated, and then the solvent is removed, and a granular thermoplastic elastomer reacted in suspension in a medium A method of separating the composition and removing the medium can be used.

The thermoplastic elastomer composition powder used for powder molding in the present invention has a primary particle size of 300 to 1000.
A mixture of powder having a primary particle size of 50 to 200 μm and a powder having a primary particle size of 50 to 200 μm in a mass ratio of 50:50 to 95: 5 is used as a powder molding material. In order to improve the quality, inorganic materials such as silica, calcium carbonate and mica having a primary particle size of 5 μm or less, or a primary particle size of 5 μm or less.
An organic substance such as a polymer powder having a size of μm or less can be mixed with the powder.

Next, powder slush molding is performed using the thermoplastic elastomer composition powder. In this molding, the composition is mainly dropped by gravity and poured into a mold heated to a temperature higher than the melting point of the composition, and after a certain period of time, the mold is inverted and excess composition is collected in a collection box. The composition adheres as a layer to the mold surface, and melts over time to form a skin layer. Then, the mold is cooled to remove the skin layer, and this is repeatedly performed.

The method of heating the mold is generally a method of circulating oil or putting it in a hot blast stove. Oil circulation is easy to adjust the mold temperature by pipe arrangement, but is heated only from the mold surface. On the other hand, when a hot blast stove is used, heating can be performed from both sides of the mold surface and the back surface of the molded product. It is necessary to consider the prescription and conditions so as not to cause oxidative deterioration.

The hot air method is effective when performing powder molding in multiple layers (two or three). That is, the first powder to be the outermost layer is powder-molded in a heated mold, the second powder is adhered in a semi-molten state, and the powder is molded a third time if necessary, and then heated and melted. In this case, if the heating is performed only from the mold surface side, the heat transfer is insufficient, so that a hot blast stove method capable of heating from the back surface of the molded product is often used.

[0052]

Next, the present invention will be described in more detail with reference to specific examples. First, each thermoplastic elastomer composition was prepared as follows. [Preparation of thermoplastic elastomer composition (TPO-A)]
In the composition shown in Table 1, 45 parts by mass of CS-3650 manufactured by Chisso Co. as a polypropylene resin, 16 parts by mass of an ethylene-octene copolymer (trade name: Engage) manufactured by DuPont Dow as an elastomer having excellent oil absorbing ability, As an organic peroxide, 0.4% of Perhexa 25B-40 manufactured by NOF Corporation
A dry blend of 5 parts by mass was supplied from a hopper, and was supplied as paraffin oil by Idemitsu Co. (PW-90) 1
2 parts by weight was injected from the vent port, and a side feeder was prepared by dry blending 27 parts by weight of Dynaron H-2320P manufactured by JSR and 0.1 part by weight of each of a heat stabilizer and a light stabilizer as a hydrogenated copolymer. Twin screw extruder (TEX manufactured by Nippon Steel Corporation)
-44) and the thermoplastic elastomer composition TP
OA pellets were prepared. The melt flow rate measured under the conditions of 230 ° C. and a load of 2.16 kgf according to JIS K7210 was 180 g / 10 min.

[Thermoplastic elastomer composition (TPO-
Preparation of B)] In the formulation shown in Table 1, 45 parts by mass of CS-3650 manufactured by Chisso Corporation as a polypropylene resin, and an ethylene-octene copolymer manufactured by DuPont Dow as an elastomer having excellent oil absorbing ability (trade name: Engage) 16 parts by mass, Nippon Yushi Co., Ltd.
0.45 parts by mass of -40 was dry-blended and supplied from a hopper, and 12 parts by mass of Idemitsu (PW-90) was injected as a paraffin oil from a vent port, and as a hydrogenated copolymer, Tuftec manufactured by Asahi Kasei Corporation 27 parts by mass of L-515 and 0.1 parts by mass of each of the heat stabilizer and the light stabilizer were dry-blended and supplied from a side feeder.
The mixture was kneaded with a twin-screw extruder (TEX-44, manufactured by Nippon Steel Corporation) having a cylinder temperature of 180 to 230 ° C to prepare pellets of a thermoplastic elastomer composition TPO-B. JIS K
When the melt flow rate was measured under the conditions of 230 ° C. and a load of 2.16 kgf according to 7210, the melt flow rate was 150 g /
It was 10 minutes.

[0054]

[Table 1]

[Thermoplastic Elastomer Composition (TPU)
Preparation] In a reaction vessel equipped with a stirrer, number average molecular weight 1,0
0.5 mol of polybutylene adipate diol, 0.5 mol of 1.4-butanediol as a chain extender, 0.98 mol of hexamethylene diisocyanate (HDI), and 0.9 mol of dibutyltin dilaurate (DBTDL) as a catalyst.
5 ml is put in a toluene medium.
After reacting at 110 ° C. for 3 hours, toluene was removed under reduced pressure, the mixture was cooled, and the solidified product was crushed by a crusher and reduced to 5 mm.
PASS milled thermoplastic elastomer composition (TP
U) was prepared. 230 ° according to JIS K7210
C. The melt flow rate was measured under the conditions of a load of 2.16 kgf. The melt flow rate was 200 g / 10 min, and the number average molecular weight was about 28,000.

Subsequently, a powder composition was prepared using the above-mentioned thermoplastic elastomer composition. Primary particle size 300-1
Preparation of 000 μm thermoplastic elastomer composition powder Each of the above thermoplastic elastomer compositions TPO-A, TPO
-B, TPU was charged from a raw material supply hopper of a single screw extruder (FS-25, manufactured by Ikegai Iron & Steel Co., Ltd.) equipped with a hot cut pelletizer equipped with a die having a diameter of 0.36 mm and 200 holes, and a cylinder. Temperature 160 ° C,
Micro pelletization was performed at a die temperature of 150 ° C., or pulverization was performed at room temperature by using an impact-type pulverizer Turbomill T250-4J (manufactured by Turbo Kogyo Co., Ltd.). The average primary particle diameter of the obtained powder composition was TPO-A 650 μm, TPO-B 670 μm.
m, and TPU 610 μm. The powder having a primary particle size of 300 μm or less contained in the powder composition pulverized at room temperature was 3% by mass or less.

[Preparation of thermoplastic elastomer composition powder having a primary particle size of 50 to 200 μm] Pellets of the thermoplastic elastomer compositions TPO-A and TPO-B are immersed in liquid nitrogen, and a turbo mill T250-4J (manufactured by Turbo Kogyo Co., Ltd.) ) And pulverized to collect only a 200 μm sieve.
The average primary particle size of the obtained powder composition is TPO-A1
70 μm and 165 μm of TPO-B.

Further, TP having a primary particle size of 50 to 200 μm
The U composition powder was placed in a reaction vessel equipped with a high-speed stirrer.
0.5 mol of polybutylene adipatediol having a number average molecular weight of 1,000 with hexane as a medium, 0.5 mol of 1.4 butanediol with a chain extender, 0.3 g of a nonionic surfactant, and 0.5 ml of DBTDL are used. After charging, 0.97 mol of HDI was dropped and reacted in a suspended state by stirring at a high speed. After the dropping, the powder was reacted at 80 ° C. for 5 hours, and the obtained powder was separated by filtration, and the medium was removed under reduced pressure. Then, a powder having a primary particle size of 50 to 200 μm was collected by a sieve and used for powder molding. The average primary particle size of the obtained TPU powder composition was 160 μm, and the number average molecular weight and the melt flow rate of this powder composition were equivalent to those of the TPU composition prepared above.

Next, powder molding was performed using the above powder composition. Examples 1 to 6, Comparative Examples 1 to 9 Powder slush molding was performed using powder compositions that were mixed at the mixing ratios shown in Tables 2 to 4. First, a 150 mm x 150 mm x 3 mm plate with a grain pattern is heated to 250 ° C in an oven, and about 800 g of the powder composition mixed with the powder is placed on the plate for 10 minutes to adhere.
Except for the powder not melt-adhered, the powder was heated in an oven adjusted to 300 ° C. for 60 seconds, taken out of the oven and cooled with water, and the skin having a thickness of about 0.8 mm was removed from the mold.

The pinholes on the front surface of the slash-formed sheet, the molten state of the back surface of the sheet, the tensile properties of the skin, the hardness, and the whitening of the fold were evaluated by the following methods. The obtained results are also shown in Tables 2 to 4.

The sheet surface pinholes were evaluated on a scale of 5 from the size and number of pinholes by observing the sheet surface obtained by powder molding with a 15-fold loupe. 5: The pinhole is hardly seen (small pinhole size) 4: The pinhole is slightly seen (small pinhole size) 3: The pinhole can be slightly confirmed visually (medium pinhole size) 2: The pinhole is small Visually confirmable and large number (medium pinhole size) 1: Pinholes can be visually confirmed and fairly large (large pinhole size) Samples were performed at n = 3, and the obtained evaluation values were averaged. Pinhole generation evaluation. In the present technology, it is assumed that a rating of 4 or more has no practical problem.

Further, even in the molten state of the back surface of the sheet,
"XX" indicates that the powder remains without being melted, and "X" indicates that the powder remains in a slightly molten state. Was evaluated as “△”.

The tensile properties of the skin obtained by powder molding were determined by JI
The sheet was punched out with an S3 dumbbell, and the tensile strength and elongation were measured at a tensile speed of 200 mm / min.

The hardness of the molded skin was measured using a JIS A hardness tester with three skins each having a thickness of about 0.8 mm.

The whitening at the time of bending the sheet is determined according to the degree of whitening by bending the powder-formed sheet and visually checking the degree of whitening. The evaluation was "x" or "△". The results are shown in Tables 2 to 4.

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

[Table 4]

As a result, in Examples 1 to 6, the sheet formability was good and there were almost no pinholes on the surface.
The back surface of the sheet is also uniformly melted and has a primary particle size of 50 to 20.
Comparative Example 3.6 in which powder molding was performed using only the 0 μm powder composition.
Even when compared with the physical property values of No. 9, the values are almost the same, and the physical strength is sufficiently practical. However, in Comparative Examples 2, 5, and 8 in which powder molding was performed only with the powder composition having a primary particle size of 300 to 1000 μm, the sheet moldability was poor, the number of pinholes on the front surface was large, and the back surface of the sheet was large. When the sample was checked, shrinkage was observed, unevenness was observed due to non-uniform melting, and underfilling and pinholes occurred on the sheet surface due to insufficient melting. Further, Comparative Examples 1, 4,
In No. 7, although the powder composition having a primary particle size of 50 to 200 μm was mixed with 3% by mass of the powder, almost no improvement in the above physical properties was observed.

[0070]

As described above, according to the invention described in each of the claims of the present application, in the thermoplastic elastomer composition powder used for powder molding, the powder composition having a primary particle size of 300 to 1000 μm, When the thermoplastic elastomer composition powder obtained by mixing the powder composition having a diameter of 50 to 200 μm at a mass ratio of 50:50 to 95: 5 is used for powder molding, the sheet moldability is good. It was found that there were almost no pinholes on the front surface, the back surface of the sheet was uniformly melted, and a skin material having sufficient physical strength was obtained.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08L 9/06 C08L 9/06 23/00 23/00 53/02 53/02 75/04 75/04 (72) Invention Person Yoshihiro Toda 4-1-1, Hamazoe-dori, Nagata-ku, Kobe-shi, Mitsusei Belt Co., Ltd. (72) Inventor Tomoyuki Tahara 4-1-1, Hamazodori, Nagata-ku, Kobe-shi Mitsuboshi Belt Co., Ltd. F-term (reference ) 4F205 AA11 AA31 AA45J AA46J AB03 AB07 AH25 AH26 GA12 GB01 GC04 GE17 4J002 AC08X AE05Z BB05Y BB12W BB14W BB15W BB15Y BP01X BP02W CK031 CK041 EK036 EK066 FD02Z FD146 GN00 HA09 4J034 BA02 CA04 CB03 CB07 CC03 DA01 DB04 DB07 DF01 DF12 DF16 DF20 DF22 DG03 DG04 HA01 HA02 HA07 HC03 HC12 HC17 HC22 HC46 HC52 HC61 HC67 HC71 JA27 QA05 QC04 QD06 RA05 RA12

Claims (10)

[Claims] 1. A thermoplastic elastomer composition powder used for powder molding, having a primary particle size of 300 to 1000 μm.
And a powder composition having a primary particle size of 50 to 200 μm in a mass ratio of 50:50 to 95: 5. Composition powder. 2. The thermoplastic elastomer composition is a composition containing an olefin-based thermoplastic elastomer as a main component, and further has a melt flow rate (MFF) of the obtained composition.
R) has a temperature of 230 ° C. according to JIS K7210,
When measured under the condition of a load of 2.16 kgf, 10 g /
The thermoplastic elastomer composition powder for powder molding according to claim 1, which is at least 10 minutes. 3. The olefin-based thermoplastic elastomer composition is obtained by hydrogenating a copolymer of a vinyl aromatic hydrocarbon compound monomer and a conjugated diene monomer in an amount of 90% or more based on 100 parts by mass of a polypropylene resin, and The proportion of the vinyl aromatic hydrocarbon compound in the hydrogenated copolymer is 5
The thermoplastic elastomer composition powder for powder molding according to claim 2, which is a composition containing at least 20 to 500 parts by mass of a hydrogenated copolymer, which is 25 to 25% by mass. 4. The hydrogenated copolymer according to claim 3, which is a random copolymer of styrene and butadiene, a random copolymer of styrene and isoprene, a block copolymer of styrene and butadiene, and a copolymer of butadiene before hydrogenation. A copolymer having an average of 1.2 bond amounts of at least 62 mol% and a copolymer of a block copolymer of styrene and isoprene having an average of at least 62 mol% of isoprene blocks before hydrogenation. A thermoplastic elastomer composition powder for powder molding, which is at least one selected from polymers. 5. An ethylene / α-olefin copolymer rubber is used in an amount of 5 to 250 parts by weight per 100 parts by mass of the hydrogenated copolymer.
The thermoplastic elastomer composition powder for powder molding according to any one of claims 3 and 4, which is blended by mass. 6. An organic peroxide comprising a polypropylene resin 10.
The thermoplastic elastomer composition powder for powder molding according to any one of claims 3 to 5, wherein 0.02 to 5.0 parts by mass is blended with respect to 0 parts by mass. 7. The thermoplastic elastomer composition powder for powder molding according to claim 2, wherein a process oil is added. 8. The thermoplastic elastomer composition is a composition mainly composed of thermoplastic polyurethane, and the obtained composition has a melt flow rate (MFR) of JI.
230 ° C, load 2.16 according to SK7210
The thermoplastic elastomer composition powder for powder molding according to claim 1, which is 10 g / 10 minutes or more as measured under kgf conditions. 9. A thermoplastic polyurethane synthesized from a diol selected from at least one polyester diol or polyether diol and a diisocyanate selected from at least one aliphatic diisocyanate or alicyclic diisocyanate. The thermoplastic elastomer composition powder for powder molding according to claim 8, wherein the number average molecular weight is 10,000 or more and less than 100,000. 10. A skin obtained by powder molding using the thermoplastic elastomer composition powder for powder molding according to any one of claims 1 to 9.