JP2001205658A - Grip and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grip having a soft feeling equal to that of RIM urethane and requring no coating by solving a problem such as the low productivity, low recyclability or the like of a grip made of RIM urethane. SOLUTION: A grip has a non-foamed skin layer with a thikness of 0.1-3 mm provided on the surface thereof and comprises foam of a thermoplastic elastomer of which the foaming ratio is 1.2-3.0 times. The thermoplastic elastomer consists of a specific high molecular polyol, polyisocyanate and, if necessary, a chain extender having two active hydrogen atoms capable of reacting with polyisocyanate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foam R used for a grip for an automobile interior, a grip (handle) for a bag, and the like.
The present invention relates to a grip that solves problems such as low productivity and low recyclability of a grip made of IM urethane, has a soft feeling equivalent to foamed RIM urethane, and does not require painting, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, resin inserted into a grip (a shift lever grip, a door grip, an assist grip at an upper part of a door used when getting on and off, a side brake lever, etc.) and a bag grip (handle) used in a car interior are used. A metal core around which a rigid resin material such as polypropylene (PP) or polyvinyl chloride (PVC) is coated is used. However, solid molded articles of PP and PVC have a hard feel when gripped, and have problems in operability and safety. On the other hand, foamed RIM urethane is used because of its excellent feel and operability.

[0003] In this regard, there has been proposed a foam of a thermoplastic elastomer. JP-A-6-21874
No. 1, JP-A-6-218742, JP-A-6-218742
JP-A-234133, JP-A-7-80885, and JP-A-7-88878 disclose a method of injecting a foamed thermoplastic elastomer into a mold cavity and then expanding the volume of the cavity to foam the surface. There has been proposed a method of forming an elastic foam having excellent properties. However, substantially these inventions are a method of increasing the cavity capacity by moving the entire design surface to be foamed after injection molding, and it is possible with a molded product having a shape close to a plane, but it is possible to use the entire surface like a grip. At present, it cannot be applied to molded products that require a soft feeling (when the entire design surface is slid, it is difficult to emboss the side surfaces to be slid, so that the appearance cannot be obtained).

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a molded article requiring a soft feeling over the entire surface, such as a grip (handle), by forming a foamed thermoplastic elastomer into a foam layer and a surface by foam injection molding. A molded body having a foamed skin layer is obtained, and it has excellent soft feel like a foamed RIM urethane grip and excellent surface appearance, and can be manufactured with higher productivity than foamed RIM urethane, and can be recycled. It is an object of the present invention to provide a grip that is capable of generating no harmful gas even when it is incinerated. further,
Excellent hydrolysis resistance, sweat resistance, light resistance, oxidation deterioration
A homogeneous grip with good elastic recovery.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a skin material comprising a skin layer containing 0.1%.
A grip made of a thermoplastic elastomer foam having an expansion ratio of 1.2 to 3.0 times and having a non-foamed skin layer having a thickness of 1 mm to 3 mm, wherein the thermoplastic elastomer has the following (a), ( It is intended to provide a grip characterized by being a polyurethane elastomer obtained by copolymerizing component (b) and, if necessary, component (c).

(A) an aliphatic polycarbonate diol comprising a repeating unit of the following formula (1) and having a terminal group of a hydroxyl group (wherein R is an aliphatic or alicyclic hydrocarbon group having 2 to 10 carbon atoms) Represent).

[0007]

Embedded image

(B) Polyisocyanate (c) Chain extender having two active hydrogens capable of reacting with polyisocyanate

The aliphatic polycarbonate diol used for the soft segment of the polyurethane elastomer of the present invention is described in Schell, Polymer Revie.
w Synthesized from aliphatic and / or cycloaliphatic diols by various methods described in Vol. 9, pages 9-20 (1964). Preferred diols include ethylene glycol, 1,2-propanediol, 1,3-
Propanediol, 1,2-butanediol, 1,3-
Butanediol, 1,4-butanediol, neopentyl glycol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 2,5-hexanediol, 1,4-cyclohexanediol,
1,4-cyclohexanedimethanol and the like can be mentioned.

In order to obtain a grip having a good balance of hydrolysis resistance (sweat resistance), weather resistance and softness, it is necessary to use 1,4
-Butanediol, 1,4-hexanediol, 1,6
-Pentanediol is particularly preferred.

The range of the average molecular weight of the polycarbonate diol used in the present invention is usually 500 in number average molecular weight.
~ 30000, preferably 600 ~ 2000
0, more preferably 700 to 60,000, and it is desirable that the terminal of the polymer is substantially all hydroxyl groups.

In the present invention, in addition to the above-mentioned diols, compounds having three or more hydroxyl groups in one molecule, such as trimethylolethane, trimethylolpropane, hexanetriol, pentaerythritol,
Polyurethane using a polycarbonate which has been polyfunctionalized by using a small amount such as the above is also included.

The polyisocyanate used in the present invention includes, for example, 2,4-tolylene diisocyanate,
2,6-tolylene diisocyanate and its mixture (TDI), diphenylmethane-4,4'-diisocyanate (MDI), naphthalene-1,5-diisocyanate (NDI), 3,3'-dimethyl-4,4'- Known aromatic diisocyanates such as biphenylene diisocyanate, crude TDI, polymethylene polyphenyl isocyanate, and crude MDI; known aromatic alicyclic diisocyanates such as xylylene diisocyanate (XDI) and phenylene diisocyanate; 4,4′-methylenebiscyclohexyl diisocyanate (Hydrogenated MDI), known aliphatic diisocyanates such as hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), and cyclohexane diisocyanate (hydrogenated XDI); Sulfonates of isocyanurate-modified products, carbodiimide-modified products, a biuretization modified products.

In the present invention, suitable chain extenders used as needed include those commonly used in the polyurethane industry. Supervised by Keiji Iwata Recent polyurethane application technology CMC 1985, pp. 25-27, including known water, low molecular polyol, polyamine and the like. A known polyol may be used in combination with the aliphatic polycarbonate used in the present invention, depending on the use of the polyurethane, as long as the effects of the present invention are not impaired. Known polyols include known polyols such as polyester and polyether carbonate described in Yoshio Imai, Polyurethane Form Polymer Publishing Association, 1987, pp. 12-23.

As a method for producing the polyurethane elastomer of the present invention, a urethane-forming reaction technique known in the polyurethane industry is used. For example, an NCO-terminated polyurethane prepolymer is produced by reacting the polyol with an organic polyisocyanate at room temperature to 200 ° C.

A thermoplastic polyurethane elastomer can be produced using the polyol, polyisocyanate and, if necessary, a chain extender. In the production of these, known polymerization catalysts represented by organic metal salts such as tertiary amines, tin, and titanium are described, for example, by Keiji Yoshida (polyurethane resin), Nihon Kogyo Shimbun, No. 23-32
Page (1969) "can also be used.
These reactions may be carried out using a solvent. Preferred solvents include dimethylformamide, diethylformamide, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran, methylisobutylketone,
Dioxane, cyclohexanone, benzene, toluene,
Ethyl cell solve and the like.

In producing the polyurethane elastomer of the present invention, a compound containing only one active hydrogen that reacts with an isocyanate group, for example, a monohydric alcohol such as ethyl alcohol and propyl alcohol, and a compound such as diethylamine and di-n-propylamine Secondary amines and the like can be used as terminal terminators.

The polyurethane elastomer of the present invention using a specific polycarbonate polyol has not only excellent flexibility and elastic recovery but also extremely good hydrolysis resistance as compared with other polyurethane elastomers. When used for a grip that touches the surface, it is particularly preferable because of excellent sweat resistance.

The polyurethane elastomer of the present invention has a Shore D hardness of preferably from 20 to 70, more preferably from 2 to 70.
The soft segment amount may be appropriately selected so as to fall within the range of 5 to 50. If the Shore D hardness is less than 20, when the grip is formed after foam molding, the followability with the core metal is poor, and there is a problem in operability. If the Shore D exceeds 70, the resulting foamed grip lacks a soft feeling, which is not preferable.

The polyurethane elastomer of the present invention has a melt flow rate (at 230 ° C., under a load of 2.16 kg; hereinafter abbreviated as MFR) of 0.5 to 100 g / 10 min.
Preferably 5 to 50 g / 10 min, more preferably 10
３０30 g / 10 min. If the MFR is less than 0.5 g / 10 minutes, the injection moldability is poor and short shots are caused, which is not preferable. Further, the MFR is 100 g / 1.
If the time exceeds 0 minutes, the foaming gas cannot be retained, and not only the foaming property is deteriorated, but also the mechanical properties (rupture strength, breaking elongation, etc.), abrasion, compression set (C-Set), etc. are inferior. Not preferred.

As additives used in the present invention, it is preferable to use at least an antioxidant, a light stabilizer and a heat stabilizer. Examples of these antioxidants include aliphatic, aromatic or alkyl-substituted aromatic esters of phosphoric acid and phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonates, dialkylpentaerythritol diacids. Phosphite,
Phosphorus compounds such as dialkylbisphenol A diphosphite; phenol derivatives, especially compounds containing sulfur such as hindered phenol compounds, thioethers, dithioates, mercaptobenzimidazoles, thiocarbanilides, thiodipropionates; tinmalate, dibutyltin mono Tin compounds such as oxides can be used.

These may be used alone or in combination of two or more. The addition amount of these stabilizers is based on 100 parts by weight of the polyetherester block copolymer.
0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight,
More preferably, the amount is 0.2 to 3 parts by weight. Normal,
Antioxidants can be divided into primary, secondary and tertiary antiaging agents. Particularly, as a hindered phenol compound as a primary anti-aging agent, Irganox 1010 (trade name: manufactured by Ciba Geigy), Irganox 1520 (trade name: manufactured by Ciba Geigy) and the like are preferable. PEP-36 and PEP-24 are phosphorus compounds as secondary aging inhibitors
G, HP-10 (both trade names: manufactured by Asahi Denka Co., Ltd.) I
rgafos168 (trade name: Ciba-Geigy) is preferred. Further, as the sulfur compound as the tertiary aging inhibitor, thioether compounds such as dilauryl thiopropionate (DLTP) and distearyl thiopropionate (DSTP) are preferable.

If necessary, an ultraviolet absorber and a light stabilizer may be added in the same manner. Examples of these ultraviolet absorbers include benzotriazole-based compounds and benzophenone-based compounds. As the light stabilizer, a radical scavenging light stabilizer such as a hindered amine compound is suitably used.

If necessary, a plasticizer may be added to the composition obtained. Examples of such plasticizers include phthalic acid esters such as dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, diisononyl phthalate: tricresyl phosphate, triethyl phosphate, Phosphate esters such as tributyl phosphate, tri-2-ethylhexyl phosphate, trimethylhexyl phosphate, tris-chloroethyl phosphate, tris-dichloropropyl phosphate: octyl trimellitate, isodecyl trimellitate, trimellitate, Dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl aze Over DOO, dioctyl azelate, dioctyl sebacate, di-2
Fatty acid esters such as ethylhexyl sebacate and methyl acetyl ricinocate: pyromellitic esters such as octyl pyromellitic acid: epoxidized soybean oil,
Epoxy plasticizers such as epoxidized linseed oil and epoxidized fatty acid alkyl esters: Polyether plasticizers such as adipic ether ester and polyether Plasticizer: liquid N
Liquid rubbers such as BR, liquid acrylic rubber and liquid polybutadiene: process oils and the like.

These plasticizers can be used alone or in combination of two or more. The addition amount of the plasticizer is appropriately selected according to the required hardness and physical properties, but is preferably 1 to 50 parts by weight per 100 parts by weight of the composition.

Kaolin, as long as the physical properties are not impaired,
Silica, mica, titanium dioxide, alumina, calcium carbonate, calcium silicate, clay, kaolin, diatomaceous earth, asbestos, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, carbon fiber, etc. Fillers and reinforcements: Lubricants or mold release agents such as zinc stearate and bis-amide amide: carbon black for coloring, ultramarine, titanium white, zinc white, zinc oxide, navy blue, azo pigment, nitro pigment, lake pigment Pigments such as phthalocyanine pigments: octabromodiphenyl,
Flame retardants such as tetrabromobisphenol polycarbonate: thickeners such as epoxy compounds and isocyanate compounds: Various known additives such as silicone oil and silicone resin can be used.

The thermoplastic elastomer composition constituting the grip of the present invention can be prepared by using various extruders, Banbury mixers,
It can be easily obtained in the form of pellets by kneading after melt kneading with a kneader, roll, or a combination thereof.

As the foaming agent used for foaming the polyurethane elastomer, any organic or inorganic foaming agent can be used as long as it can normally foam the polyurethane elastomer by injection molding. Specific examples of such a foaming agent include azo compounds such as azodicarboxylic acid amide, nitroso compounds such as N, N'-dinitrosopentamethylenetetramine, carbonates such as sodium bicarbonate and ammonium bicarbonate, citric acid, Organic acids such as sodium citrate and oxalic acid, and sodium borohydride can be exemplified. Further, a combination of a carbonate and an organic acid may be used. When foam molding is performed at a relatively high temperature, compounds such as p, p'-oxybisbenzenesulfonylsemicarbazide, p-toluenesulfonylsemicarbazide, trihydrazinotriazine, and barium azodicarboxylate can also be used. However, azodicarboxylic acid amide is generally preferred. As a method of adding a foaming agent, a method of adding a foaming agent at the time of material kneading, or a method of adding a foaming agent or a master batch thereof during molding may be used.

The amount of the foaming agent is 0.01 to 100 parts by weight of the polyetherester block copolymer.
10 to 10 parts by weight, preferably 1 to 9 parts by weight, more preferably 2 to 7 parts by weight. If the amount of the foaming agent is less than the above range, the expansion ratio is inferior, and if the amount exceeds the above range, the appearance of the foam is inferior.

[0030]

EXAMPLES Hereinafter, the present invention will be described in more detail, but the present invention is not limited to the examples. The method of synthesizing the aliphatic copolycarbonate diol is shown below as a reference example.

Reference Example 1 970 g of ethylene carbonate (EC) was placed in a 3 liter flask equipped with a Dixon packing 3φ and having a diameter of 10 mm and a length of 300 mm, a thermometer, and a stirrer.
(11 mol), 1,4-butanediol (BDL) 99
0 g (11 mol) was added, and the mixture was heated and stirred under a reduced pressure of 20 torr, and the internal temperature was controlled to 150 ° C. The reaction was carried out for 20 hours while distilling EC having an azeotropic composition and ethylene glycol (hereinafter abbreviated as EG) from the top of the distillation column. Next, the distillation column was removed and the degree of vacuum was reduced to 7 torr.
At r, unreacted EC and diol were recovered. After the completion of the distillation of the unreacted substances, the internal temperature was set to 190 ° C., and the diol was distilled while maintaining the temperature to carry out a self-condensation reaction to increase the molecular weight. Four hours later, a polymer having a molecular weight of 2100 was obtained by GPC analysis. The yield was 650 g and the hydroxyl value was 57 mgKOH / g. This polymer is abbreviated as pc-a.

Reference Example 2 Using 1,5-pentanediol as a diol,
An aliphatic copolycarbonate diol (pc-b) was obtained in the same manner as in Reference Example 1, except that the charged amount of 5-pentanediol was changed to 1140 g. The yield was 730 g, the hydroxyl value was 55 mgKOH / g, and the molecular weight by GPC analysis was 2,000.

Reference Example 3 970 g of ethylene carbonate (EC) was placed in a 3 liter flask equipped with a Dixon packing 3φ and having a diameter of 10 mm and a length of 300 mm, a thermometer, and a stirrer.
(11 mol), 1,4-butanediol (BDL) 65
0 g (5.5 mol), 1,5-pentanediol (P
DL) 570 g (5.5 mol) and add 20 torr
The mixture was heated and stirred under reduced pressure, and the internal temperature was controlled to 150 ° C. While distilling azeotropic EC and ethylene glycol (hereinafter abbreviated as EG) from the top of the distillation column, 2
The reaction was performed for 0 hours. Next, the distillation column was removed, the degree of vacuum was reduced to 7 torr, and unreacted EC and diol were recovered. After the completion of the distillation of the unreacted substances, the internal temperature was set to 190 ° C., and the diol was distilled while maintaining the temperature to carry out a self-condensation reaction to increase the molecular weight. 4 hours later, GP
A polymer having a molecular weight of 2000 was obtained by C analysis. The yield was 740 g and the hydroxyl value was 56 mgKOH / g. This polymer is abbreviated as pc-c. Raw materials used in Examples and Comparative Examples and evaluation methods are as follows.

1. Polyurethane elastomer (hereinafter TP)
Component (1) TPU-1: 200 g of pc-a obtained in Reference Example 1,
67.2 g of hexamethylene diisocyanate was charged into a reactor equipped with a stirrer, a thermometer, and a cooling tube, and was charged at 100 ° C.
For 4 hours to obtain a prepolymer having terminal NCO. A chain extender of 1,4-butanediol 30 is added to the prepolymer.
g, dibutyltin dilaurate 0.006 as a catalyst
g, and the mixture is reacted at 140 ° C. for 60 minutes with a universal extruder for laboratories with built-in kneader (Model KR-35 for LABO manufactured by Kasamatsu Chemical Industries, Ltd.), and extruded at a cylinder temperature of 180 ° C. to 200 ° C. The polymerization was completed with a pelletizer to form urethane pellets. The obtained urethane elastomer had a Shore D hardness of 40 and an MFR of 27.

(2) TPU-2: A urethane elastomer was obtained by polymerization in the same manner as in the synthesis method of TPU-1, except that pc-b was used as the polycarbonate diol. The resulting urethane elastomer has a Shore D hardness of 38, MF
R was 25.

(3) TPU-3: A urethane elastomer was obtained by polymerization in the same manner as in the synthesis of TPU-1, except that pc-c was used as the polycarbonate diol. The resulting urethane elastomer has a Shore D hardness of 35, MF
R was 29.

(4) TPU-4: TPU-4 was synthesized in the same manner as in the synthesis of TPU-1, except that polycaprolactone polyol (Placcel 220, molecular weight: 2,000) was used as the aliphatic copolycarbonate diol. . The obtained urethane elastomer had a Shore D hardness of 42 and an MFR of 27.

(5) TPU-5: milactolan E19
0 (MDI / adipate TP manufactured by Nippon Miractran Co., Ltd.)
U), Shore D hardness 45, MFR; 28

2. Blowing agent component (1) BA-1: azodicarboxylic amide (2) BA-2: sodium bicarbonate

3. Injection molding machine Horizontal injection molding machine for general resin, injection capacity: 1,200cm
³ , mold clamping force: 1,000 tonf. Nozzle; Valve nozzle (Nozzle with a pressure valve that can be injected above a certain pressure. Suppress foaming in the cylinder.)

4. Evaluation Method (1) Measurement of Expansion Ratio The value obtained by dividing the specific gravity of an unfoamed product by the specific gravity of the foam obtained from the volume and weight of the product after molding using a grip mold was defined as the expansion ratio (times). Corrected by subtracting the weight of the metal core).

(2) Measurement of Skin Layer Thickness The formed grip was cut, and observed with a graduated loupe (measurement sites were BB cross section and design portion in FIG. 1).

(3) Method of Measuring Foam Hardness The design surface of the grip (the measurement site is the BB cross section in FIG. 1 of the accompanying drawings) was measured using JIS-A hardness according to JIS-K6301.

(4) Feeling Judgment is made based on the feeling when grasped by hand. Good: Good; Normal: Bad;

(5) Appearance Judged visually. ○: good ×: poor (transfer of silver, satin finish etc.)

(6) Sweat Resistance The grip was immersed in artificial sweat (artificial sweat composition: 7 g of NaCl, 500 cc of methyl alcohol, 1 g of urea, 4 g of lactic acid, 500 cc of distilled water) at room temperature for 30 days. The appearance after taking out the grip and performing a wear test (JIS K7
204 after wear test) was rated on a scale of 3. 3; not recognized at all 2; slightly recognized 1; clearly recognized

Embodiment 1 Embodiment 1 will be described with reference to FIGS. FIG. 1 shows a grip formed in this embodiment. The grip has a metal insert 11 at the center, and the metal insert 11 has a mounting hole 12 for mounting the grip. This metal insert 11
Is usually made of a metal such as iron or aluminum, and is hereinafter referred to as a core metal. Around the core metal, a T
The PE foam 21 is coated.

FIG. 2 shows a cutaway section taken along the line BB. The inside of the molded part of TPE is foamed (symbol 23).
Part), a non-foamed skin layer (symbol 22) is formed on the surface.

FIGS. 3 and 4 show a typical mold structure for foam-molding the grip. FIG. 3 is a view showing the structure of the mold as viewed from the lateral side of the molding machine. The cavity 37 into which the core metal 11 is inserted is formed by a movable slide core. Has a mechanism that can be slid into the interior of the cavity after it is mounted at a predetermined position. FIG.
FIG. 3 is a view showing a structure of a mold as viewed from a nozzle side of an injection molding machine. A movable slide core is provided so that a part of a non-design surface of a grip can slide. By increasing the projected cross section of the movable slide core, it is possible to increase the foaming ratio of the obtained grip. The preferred ratio of the projected area is 50 to 99% of the total projected area of the non-designed surface, more preferably 70 to 95%. If the projected area of the movable slide core is less than 50%, the expansion ratio of the obtained foam is low, which is not preferable. Further, when the projected area of the movable slide core is 100%, the cross section becomes the slide portion on the side surface of the slide portion (that is, the side surface of the product). .

Here, the projected area of the slide core corresponds to the area of the slide core 33 in the mold plan view FIG. 4, and the total projected area corresponds to the area of the cavity 37. .

Next, the injection foam molding of Example 1 will be specifically described with reference to FIG. FIG. 5 is a cross-sectional view of the CC cross-section of FIG. 4 as viewed from above the injection molding machine. First, the cavity cross-sectional area is minimized with the slide core advanced (Step 1). The sliding distance should be as close as possible to the metal core 11. The distance between the slide core and the core 11 is 1 m
Set to about m. In this state, the foamable TPU is injected. TPU-1 was used as the TPU, and azodicarboxylic acid amide was used as a blowing agent by dry blending 3 parts by weight with respect to 1100 parts by weight of TPU-1 before injection molding. In Example 1, the cylinder temperature of the injection molding machine was set from 200 ° C. to 220 ° C. from the hopper side to the nozzle side. The filling amount is 60 to 100%, preferably 80 to 100% of the total cavity volume when the slide core is advanced.
97%, more preferably 90-95% is filled. If the filling amount is 60% or less, the appearance of the final foamed molded product obtained is poor, which is not preferable. The injection speed is preferably completed within 8 seconds, more preferably within 5 seconds. If the injection speed exceeds 8 seconds, the thickness of the skin layer becomes too large and a soft feeling cannot be obtained, which is not preferable. The mold temperature is 20
~ 60 ° C is preferred. If the mold temperature is less than 20 ° C., the skin layer becomes thick, and if it exceeds 60 ° C., the molding cycle becomes undesirably long.

Next, immediately after the end of the injection, the movable slide core 3
3 is retracted (step 2). By retreating, the cavity capacity is increased, and the expansion ratio can be increased. The timing at which the movable slide core is retracted is within 4 seconds, preferably within 2 seconds, more preferably within 1 second after the end of the injection. If the timing of retreating the movable slide core exceeds 4 seconds, cooling proceeds and the thickness of the skin layer becomes thick, and the soft feeling is lost. Further, even if the movable slide core is retracted, the surface is completely solidified, so that the slide portion of the final molded product has a concave shape, which is not preferable.

After the molded product is retracted from the movable slide core,
After cooling for about 30 seconds, the mold is opened and taken out. When removing the molded product, the molded product can be easily removed by moving the movable slide core forward with the mold open. Table 1 shows the evaluation results of the grips thus obtained.

Examples 2 to 8 Using TPU-1 to 3, molded in the same manner as in Example 1 under the molding conditions shown in Tables 1 and 2. Tables 1 and 2 show the evaluation results of the obtained grip.

[0055]

[Table 1]

[0056]

[Table 2]

Comparative Examples 1 to 4 Using TPU-2, TPU-4 and TPU-5, grips were formed under the conditions shown in Table 3. The results are shown in Table 3. As shown in Table 3, grips molded under materials other than the present invention or molding conditions had some problems.

[0058]

[Table 3]

[0059]

The grip formed according to the present invention has the following characteristics.
It has a very good softness equivalent to that of IM urethane foam, and can solve the problems of low productivity and low recyclability of the grip made of RIM urethane foam, and can eliminate the painting step.

[Brief description of the drawings]

FIG. 1 is a plan view of a grip according to an embodiment of the present invention, and a cross-sectional view taken along line AA.

FIG. 2 is a cutaway perspective view of the grip shown in FIG. 1 taken along the line BB.

FIG. 3 is a diagram showing a structure of a mold as viewed from a lateral side of a molding machine.

FIG. 4 is a view showing a structure of a mold as viewed from a nozzle side of the injection molding machine.

FIG. 5 is an enlarged view of a cross section taken along line CC of FIG. 4 as viewed from above a mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Core metal 12 Grip mounting hole 21 Foamed TPU grip 22 TPU skin layer 23 TPU foamed layer 31 Moving type 32 Fixed type 33 Movable slide core 34 Sprue 35 Runner 36 Gate 37 Cavity

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // B29K 75:00 B29K 75:00 105: 04 105: 04 B29L 31:30 B29L 31:30 F term ( 3B088 CA15 4F202 AA42 AA45 AB02 AD03 AG20 AH17 CA11 CB01 CB12 CB30 CK19 CK54 4F206 AA42 AA45 AB02 AG20 AH17 JA04 JB12 JB30 JN25 JQ81 4J034 BA08 CA04 DA01 DB04 DF02 HA01 HC07 HC12 HC01 HC07 HC12 HC01 HC07 HC12 HC01

Claims (3)

[Claims] 1. A grip made of a thermoplastic elastomer foam having an expansion ratio of 1.2 to 3.0 times, having a non-foamed skin layer having a thickness of 0.1 mm to 3 mm on a skin layer. A grip, wherein the plastic elastomer is a polyurethane elastomer having a Shore D hardness of 20 to 70, obtained by copolymerizing the following components (a) and (b) and, if necessary, component (c). (A) a polycarbonate diol comprising a repeating unit represented by the following formula (1) and having a terminal group of a hydroxyl group (wherein R
Represents an aliphatic or alicyclic hydrocarbon group having 2 to 10 carbon atoms). Embedded image (B) Polyisocyanate (c) Chain extender having two active hydrogens capable of reacting with polyisocyanate 2. Using a mold provided on a non-design surface of a cavity and having a movable slide core, the slide core is slid into the cavity in advance,
The polyurethane elastomer (A) 100 according to claim 1,
A foamable thermoplastic elastomer comprising 0.1 parts by weight of a foaming agent and 0.01 to 10 parts by weight of a foaming agent (B) was placed in a mold cavity and the total cavity volume in a state where a slide core was slid into the cavity. A method for manufacturing a grip, comprising: after injecting at a filling amount of 60% or more, retracting the slide core within 4 seconds from the end of injection to foam. 3. The grip and the method for producing a grip according to claim 1, wherein the polycarbonate diol component is a polycarbonate diol having a repeating unit represented by the following formula (2) and a terminal group being a hydroxyl group. Is 4
And / or an integer of 5). Embedded image