JPH1055607A - Soft material bonded electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain electronic parts having excellent performance and high dimensional accuracy by thermally fusing an ester elastomer and amide elastomer to a non-olefinic thermoplastic resin support. SOLUTION: The non-olefinic thermoplastic resin comprises, for example, arom. polycarbonate having a modulus of elasticity in bending of >=15,000kg/cm<2> . The thermoplastic elastomer comprises, for example, ester system TPE and amide system TPE having hardness of >=80. The thermoplastic resin support is previously molded and, thereafter, a soft member is thermally fused as the thermoplastic elastomer thereto, by which the electronic parts having the excellent performance, such as antislip property and impact relieving property, and high dimensional accuracy are obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electronic components such as waterproof housings for mobile phones and vibration-proof components, as well as holding members for information recording media.

[0002]

2. Description of the Related Art As shown in FIG. 1, a turntable for an electronic component, for example, a CD-ROM, has a disk-shaped support base 3 which is mounted on the tip of a rotating drive shaft 2 and rotates. An annular soft ring 4 is fixed to the upper surface of 3,
An information recording medium disk 5 such as a CD-ROM is held between a soft ring 4 and a clamper 6 to rotate. Since the information recording medium disk 5 and the support base 3 are required to have a high degree of dimensional accuracy, both are made of an amorphous engineering plastic material, especially polycarbonate (hereinafter referred to as PC).
Sometimes described as resin. ) Is mainly used.

The soft ring 4 has a high coefficient of friction with respect to the disc in order to maintain a sufficient holding force of the information disc during high-speed rotation, and at the same time, contaminates the disc due to sticking to the information disc, It is required that the resistance at the time of removal is small. Therefore, conventionally, P
Urethane coating is applied to a support base made of C resin (JP-A-3-18535), or a sheet-like thermosetting rubber such as chloroprene rubber is adhered via an adhesive tape or the like. However, in these methods, the cost is high due to the complicated manufacturing process, and the friction coefficient with the disk becomes insufficient due to the increase in the number of rotations of the desk.
The unevenness in the thickness of the coating film impairs the surface accuracy of the information disk, causing problems such as fluttering. On the other hand, if the thermoplastic elastomer can be thermally fused to the support base 3 at the same time as the molding, it is extremely advantageous in terms of cost and surface accuracy. However, thermoplastic elastomers such as styrene-based elastomers and olefin-based elastomers cannot be practically used because of insufficient heat-fusibility with polycarbonate and the like.

[0004]

DISCLOSURE OF THE INVENTION The present inventors are inexpensive and have excellent performances such as anti-slip properties and shock-absorbing properties.
It is an object to provide an electronic component having high dimensional accuracy.

[0005]

According to the present invention, a thermoplastic elastomer comprising one or more selected from ester-based elastomers and amide-based elastomers is obtained by using a non-elastomer having a flexural modulus of 15,000 kg / cm ² or more. An object of the present invention is to provide a soft body-bonded electronic component characterized by being thermally fused to an olefin-based thermoplastic resin support.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An electronic component according to the present invention is formed by bonding a soft body with a support serving as a main body or a skeleton of the electronic component. Taking a turntable of an information disk as an example, as shown in FIG. 1, the turntable 1 is composed of a support base 3 as a support and a soft ring 4 made of a soft body coupled to an upper surface thereof. . For the support, a non-olefin-based thermoplastic resin having a flexural modulus of 15,000 kg / cm ² or more is used, and a thermoplastic elastomer is used as a soft body.

(1) Non-olefin-based thermoplastic resin As the non-olefin-based thermoplastic resin, a resin having excellent rigidity is used, and aromatic polycarbonate, polybutylene terephthalate, polyphenylene sulfide, and various polyamides (nylon 6, 66, nylon 610, nylon M
XD6), at least one resin selected from the group consisting of non-olefin resins such as polyetherimide, polysulfone, polyethersulfone, acrylic resin, styrene resin, and modified polyphenylene ether;
Flexural modulus according to IS-K7203 is 15,000kg
/ Cm ² or more, preferably 20,000 kg / cm ² or more, more preferably 22,000 kg / cm ² or more.

[0008] If the flexural modulus is lower than this, the motor driving shaft is press-fitted into the hole at the center of the turntable, and the tightening force on the shaft is small. Further, if the hole of the product is reduced to increase the tightening force, the product is deformed at the time of press-fitting and the surface accuracy is significantly impaired. Further, among the above non-olefin resin materials, a polycarbonate resin is desirable in terms of a good balance of dimensional accuracy, heat resistance, cost, and heat sealability with the elastomer soft member.

(2) Thermoplastic Elastomer As the thermoplastic elastomer, ester thermoplastic elastomer (ester TPE) and / or amide thermoplastic elastomer (amide TPE) are used.
The ester-based TPE and the amide-based TPE used in the present invention are:
A thermoplastic elastomer (TPE) in which a hard segment is composed of a crystal part of a segment having an ester group or an amide group can be used. The hardness of these TPEs is preferably JIS-A hardness (K6301) of 75 or more, more preferably 80 or more, and still more preferably 85 or more in terms of low sticking to the medium.

(A) Ester-based thermoplastic elastomer The ester-based elastomer of the present invention is JIS-K720.
The flexural modulus according to 3 is 1,000 MPa or less. Preferably 0-600MPa, particularly preferably 10-600MPa
a is preferred. Such ester-based elastomers include an aromatic polyester as a hard component, a polyester polyether block copolymer using an aliphatic polyether as a soft component, an aromatic polyester as a hard component, and an aliphatic polyester as a soft component. Polyester A polyester block copolymer is exemplified.

(A) Polyester Polyether Block Copolymer The polyester polyether block copolymer comprises an aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, an aromatic dicarboxylic acid or an alkyl ester thereof, and a weight. It is obtained by polycondensing an oligomer obtained by an esterification reaction or a transesterification reaction with a polyalkylene ether glycol having an average molecular weight of 400 to 6,000 as a raw material. As the aliphatic and / or alicyclic diol having 2 to 12 carbon atoms used in the present invention, those known as raw materials for polyesters, in particular, raw materials for polyester elastomers can be used. Examples include methylene glycol, 1,4-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, and the like, preferably 1,4-butanediol and ethylene glycol, particularly preferably 1,4-butane A diol is a main component, and one or more kinds can be used.

As the aromatic dicarboxylic acid, those known as raw materials for polyesters, especially polyester elastomers, can be used, and terephthalic acid, isophthalic acid,
Examples thereof include phthalic acid and 2,6-naphthalenedicarboxylic acid, preferably terephthalic acid and 2,6-naphthalenedicarboxylic acid, particularly preferably those containing terephthalic acid as a main component. The above may be used in combination. Examples of the alkyl ester of an aromatic dicarboxylic acid include dimethyl esters such as dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate and 2,6-dimethyl naphthalate, and preferably dimethyl terephthalate and 2,6-dimethyl naphthalate. Yes, particularly preferred is dimethyl terephthalate, which may be used in combination of two or more. Also,
In addition to the above, trifunctional diols, other diols and other dicarboxylic acids and esters thereof may be copolymerized in small amounts, and further, aliphatic dicarboxylic acids or alicyclic dicarboxylic acids such as adipic acid, or alkyl esters thereof. And the like may be used as a copolymer component.

As the polyalkylene ether glycol, those having a weight average molecular weight of 400 to 6,000 are used, preferably 500 to 4,000, particularly preferably 600 to 3,000. Molecular weight 400
If it is less than 3, the blockability of the copolymer will be insufficient, and if the weight average molecular weight exceeds 6,000, the physical properties of the polymer will decrease due to phase separation in the system. Further, those having a weight average molecular weight of 2,000 or less, more preferably 1,500 or less are preferable in that they have low sticking property to a medium. Here, as the polyalkylene ether glycol, polyethylene glycol, poly (1, 2, and 1,
(3 propylene ether) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, a block or random copolymer of ethylene oxide and propylene oxide, and a block or random copolymer of ethylene oxide and tetrahydrofuran. Particularly preferred is polytetramethylene ether glycol. The content of the polyalkylene ether glycol is 5 to 8 with respect to the produced block copolymer.
0% by weight, preferably 20 to 70% by weight.
% By weight, particularly preferably 20 to 65% by weight. When the content is more than 80% by weight, the adhesiveness to the information disc increases.

(B) Polyester polyester block copolymer The polyester polyester block copolymer of the present invention may be substituted by an aliphatic or alicyclic compound instead of the above-mentioned polyalkylene ether glycol having a weight average molecular weight of 400 to 6,000. A polyester oligomer obtained by condensing a dicarboxylic acid and an aliphatic diol, a polyester oligomer synthesized from an aliphatic lactone or an aliphatic monool carboxylic acid, the aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, It is obtained by polycondensation of an oligomer obtained by an esterification reaction or a transesterification reaction using an aromatic dicarboxylic acid or an alkyl ester thereof as a raw material.

Examples of 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid,
Alicyclic dicarboxylic acids such as dicyclohexyl-4,4'-dicarboxylic acid or one or more aliphatic dicarboxylic acids such as succinic acid, oxalic acid, adipic acid, sebacic acid and ethylene glycol, propylene glycol, tetramethylene glycol; Examples thereof include polyester oligomers having a structure in which one or more diols such as pentamethylene glycol are condensed, and examples thereof include polycaprolactone-based polyester oligomers synthesized from ε-caprolactone, ω-oxycaproic acid, and the like.

(C) Method for producing polyester-based elastomer The esterification, transesterification, and polycondensation reaction in the present invention can be carried out according to a conventional method. As the catalyst in these reactions, one or two or more of known catalysts such as alcoholates such as tin, titanium, zinc and manganese, chlorides and oxides can be used, respectively. Catalysts, especially tetrabutyl titanate, are desirable. Phosphoric acid, phosphorous acid, hypophosphorous acid, or a metal salt thereof may be added as an auxiliary agent. In particular, it is preferable to add an alkali metal hypophosphite since the content of terminal carboxyl groups is reduced and the hydrolysis resistance is improved.

Examples of the alkali metal hypophosphite include sodium hypophosphite, potassium hypophosphite, lithium hypophosphite and the like, and sodium hypophosphite is particularly desirable. The amount of the alkali metal hypophosphite added is 1 to 1,000 ppm, preferably 3 to 200 ppm, more preferably 5 to 80 ppm, based on the produced polymer. If it is less than 1 ppm, the effect of the addition cannot be sufficiently obtained, and if it is added more than 1,000 ppm, the effect is not changed but the polycondensation reaction is inhibited, which is not preferable.

As an addition method, the alkali metal hypophosphite may be added to the molten polymer in any state of a solution, a slurry, or a solid. The timing of addition is preferably at least before completion of the polycondensation reaction. That is, it may be added at any time from before the esterification reaction or transesterification reaction to before the end of the polycondensation reaction. In particular, it is preferable to add in the form of a slurry immediately before the start of the polycondensation under reduced pressure, since the decrease in polymerizability is small.

In the reaction step, other additives may be present. For example, known additives such as a hindered phenol-based oxidation stabilizer, a hindered amine-based oxidation stabilizer, a phosphorus-based oxidation stabilizer, a sulfur-based oxidation stabilizer, and a triazole-based light stabilizer are used. In particular, in the present invention, 0.01 to 1% by weight of the hindered phenol-based oxidation stabilizer is more preferably added to the polymer from the viewpoint of the effect. The esterification or transesterification reaction is usually performed at 120 to 250 ° C., preferably 150 to 230 ° C., and the melt polycondensation reaction is generally performed at 200 to 280 ° C. for 2 to 6 hours under a reduced pressure of 10 torr or less.

Usually, the polymer obtained by melt polymerization is
The temperature is maintained at a temperature equal to or higher than the melting point, and discharge and pelletization are sequentially performed from the reactor. The pellets obtained here are:
If necessary, solid phase polymerization may be further performed. As such a polyester polyether block copolymer,
Commercially available polymers such as "Perprene P" (trade name, manufactured by Toyobo Co., Ltd.), "Hytrel" (trade name, manufactured by Dupont Toray), "Lomod" (trade name, manufactured by Nippon GE Plastics), and "Nichigo Polyester" ( Nippon Synthetic Chemical Industry Co., Ltd.), Teijin Polyester Elastomer
(Trade name, manufactured by Teijin Limited), and the polyester-polyester block copolymer includes “Perprene S” (trade name, manufactured by Toyobo Co., Ltd.) which is a commercially available polymer.

(B) Polyamide-based thermoplastic elastomer The above-mentioned polyamide-based thermoplastic elastomer has polyamide (nylon 6, 66, 11, 12 or the like) as a hard segment and polyether or polyester as a soft segment. For example, polyether block amide is represented by the following general formula [1]. General formula [1]

[0022]

Embedded image

(Wherein PA represents a polyamide block which is a hard segment, and PG represents a polyether block which is a soft segment.) The PG is used in the present invention and represented by the chemical formula represented by the above general formula [I]. The polyether block amides are known per se, as disclosed in U.S. Pat. No. 3,044,978.

These include, for example, (a) salts of diamines and dicarboxylic acids, lactams, or aminodicarboxylic acids (PA constituents), and (b) polyoxyalkylene glycols such as polyoxyethylene glycol and polyoxypropylene glycol. It is adjusted by polycondensing (PG component) and (c) dicarboxylic acid. Commercially available products include “Pebax” (trade name, manufactured by Toray Industries, Inc.), “Diamid-PAE” (trade name, manufactured by Daicel Huls),
“UBE polyamide elastomer” (trade name, manufactured by Ube Industries, Ltd.), “Novamit PAE” (trade name, manufactured by Mitsubishi Chemical Corporation), “Greak A” (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), "Grillon ELX, ELX" (trade name, manufactured by MMS Japan Co., Ltd.) and the like.

(3) Additional compounding agent-1 The above-mentioned TPE can be compounded with optional compounding components according to various purposes. Specifically, softeners for hydrocarbon rubber (average molecular weight 300 to 2,000), various plasticizers, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers,
Various additives such as a neutralizer, a lubricant, an anti-clouding agent, an anti-blocking agent, a slip agent, a crosslinking agent, a crosslinking aid, a colorant, a flame retardant, a dispersant, and an antistatic agent can be added. Furthermore, various elastomers and various thermoplastic resins can be blended within a range that does not significantly impair the effects of the present invention.

Further, examples of the elastomer in the additional compounding material component include an olefin-based elastomer, a styrene-based elastomer, and a urethane-based elastomer. Examples of the olefin elastomer include olefin copolymer rubbers, for example, ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer rubber (EPDM), etc. An elastic body of a copolymer, or an elastic body which has been subjected to a heat treatment in the presence of an organic peroxide and crosslinked mainly by radicals, is contained as a basic component. As the styrene-based elastomer, a hydrogenated product of a styrene / conjugated diene block copolymer selected from a hydrogenated product of a styrene / butadiene block copolymer or a hydrogenated product of a styrene / isobrene block copolymer or a mixture thereof Which are contained as a basic component.

The thermoplastic resin in the above-mentioned additional compounding materials includes polyolefin resins such as polypropylene, ethylene resin and polybutene-1 resin, polystyrene, acrylonitrile / styrene copolymer, acrylonitrile / butadiene / styrene copolymer. Polystyrene resins such as coalesced resins, polyphenylene ether resins, polyamide resins such as nylon 6 and nylon 66, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyoxymethylene such as polyoxymethylene homopolymer and polyoxymethylene copolymer Resin, polymethyl methacrylate resin, or the like can be used.

As the ethylene resin, polyethylene,
Examples thereof include an ethylene / α-olefin copolymer, an ethylene / vinyl acetate copolymer, an ethylene / (meth) acrylic acid copolymer, and an ethylene / (meth) acrylate copolymer. Examples of the polyethylene include low-density polyethylene (branched ethylene polymer) and medium density,
High density polyethylene (linear ethylene copolymer) and the like can be mentioned.

(4) Additional compounding material-2 These resins to be used may further contain additional components as required. For example, glass fiber, carbon fiber, silica fiber, silica-alumina fiber, potassium titanate fiber, aluminum borate fiber, stainless fiber,
Inorganic fibrous reinforcing materials such as aluminum fibers, organic fibrous reinforcing materials such as aramid fibers, polyimide fibers, and fluororesin fibers; inorganic fillers such as talc, calcium carbonate, mica, glass beads, glass powder, and glass balloons;
Various additives such as fluororesin powder, solid lubricant such as graphite, molybdenum disulfide and the like can be mentioned.

In particular, when used for a media holding component such as a turntable, the above-described various types are used to improve the tightening force on the press-fitted drive shaft, improve the dimensional accuracy of the component, and prevent the resonance of the component due to rotation. It is desirable to reinforce with a filler. The reinforcing material is a non-olefin thermoplastic resin 1.
0 to 250 parts by weight, preferably 20 parts by weight
It is preferable to mix it in an amount of up to 150 parts by weight.

(Manufacture of Composite Molded Product) As a method of bonding a thermoplastic elastomer soft part and a thermoplastic resin support, a support is formed in advance, and then a thermoplastic elastomer soft member is thermally fused to the support. Alternatively, a thermoplastic resin supporting member may be heat-fused to a thermoplastic elastomer soft part that has been molded in advance. Examples of a method for producing such a composite molded article include a T-die laminate molding method, a co-extrusion molding method, a blow molding method, an insert injection molding method, a two-color injection molding method, a core back injection molding method, a sandwich injection molding method, and an injection molding method. Various molding methods such as a press molding method can be used. Among them, insert injection molding, two-color injection molding, and core back injection molding are desirable from the viewpoint of productivity.

In the insert injection molding method, for example, a material for a support (a non-olefin-based thermoplastic resin) is previously molded by injection molding, extrusion molding, sheet molding, film molding, or the like, and the formed molded product is molded into a mold. A molding method in which a soft member (thermoplastic elastomer) is injection-molded in a gap between the molded product and the mold after being inserted into the mold, or a soft member is previously subjected to injection molding, extrusion molding, sheet molding, film molding, or the like. This is a molding method in which after molding, a molded article that has been shaped is inserted into a mold, and a material for a support member is injection-molded into a gap between the molded article and the mold.

[0033] The two-color injection molding method means that the mold is rotated or moved after the support member is injection-molded using two or more injection molding machines, so that the cavity of the mold is exchanged. This is a molding method in which a gap is formed between the molded product and the mold, and a soft member is injection-molded there. In addition, the core back injection molding method is to use a single injection molding machine and a single mold to perform injection molding of a support material, and then increase the cavity volume of the mold, and This is a molding method in which a soft member is injection-molded in a gap between the mold and the mold. Further, the support member may be formed by using a normal injection molding method, or may be formed by performing gas injection molding.

The runners, spools, and the like consisting only of the soft member are used as the soft member, and the support members alone, or the runner, the spools, the defective molded products, and the like consisting of the support member and the soft member are recycled and used as the support member. You can also.
The present invention is directed to information such as information storage medium holding members, mobile phones, cordless phones, car navigation, packing of various remote control housings, various non-slip components, vibration absorbing components such as leaf springs, and vibration isolating components. Can be used for electronic components. The holding member for the information recording medium is paper, optical disc,
A holding member for fixing an information recording medium such as a magneto-optical disk or a magnetic tape at a predetermined position, or for moving the information recording medium at an accurate position, specifically, information on a CD-ROM, a magneto-optical disk, a digital video disk, etc. It is used for disk turntables, pinch rollers for video tape recorders and the like, copiers, paper feed rollers for printers, and the like.

[0035]

EXAMPLES The TPE used in the examples is described below. Ester-based TPE (E-1) 30 parts by weight of dimethyl terephthalate, 18 parts by weight of 1,4-butanediol, 77 parts by weight of polytetramethylene ether glycol (average molecular weight: 2,000),
As a catalyst, tetrabutyl titanate was added in an amount of 200 ppm, in terms of titanium metal, to the polymer to be produced.
Perform a transesterification reaction at 50 to 230 ° C. for 3.5 hours,
Then, 50 ppm of sodium hypophosphite monohydrate relative to the polymer to be produced, a hindered phenol-based oxidation stabilizer [Ciba Geigy Co., Ltd. product name: Irg
anox1330] 0.2 parts by weight, and melt polycondensation was conducted at 230 to 245 ° C. under a reduced pressure of 3 torr or less, and ester-based TPE (polyester polyether block copolymer: polytetramethylene ether glycol content 77 parts by weight, Density 1.05 g / cm ³ , JIS-A hardness 77, MFR (245 ° C, 2.16 kg load) 45 g /
10 minutes). Next, this ester-based TPE100
The silicone oil (SH200 manufactured by Dow Corning Toray Silicone Co., Ltd.)
10 cs ") and then melt-kneaded at 180 ° C. using a twin-screw extruder.

Ester TPE (E-2) E-1 was prepared by using 32 parts by weight of dimethyl terephthalate, 20 parts by weight of 1,4-butanediol, and 70 parts by weight of polytetramethylene ether glycol (average molecular weight: 2,000). Ester-type TPE (polyester polyether block copolymer: polytetramethylene ether glycol content: 70 parts by weight, density: 1.07
g / cm ³ , JIS-A hardness 82, MFR (245 ° C.,
2.16 kg load) 40 g / 10 min) was produced.

Ester-based TPE (E-3) Silicone oil (Dow Corning Toray, Toray) was used as a release agent with respect to 100 parts by weight of the ester-based TPE (E-2).
"SH200 100cs" manufactured by Silicone Co., Ltd.)
After mixing 1 part by weight, the mixture was melt-kneaded at 200 ° C. using a twin-screw extruder.

Ester-based TPE (E-4) Using 40 parts by weight of dimethyl terephthalate, 25 parts by weight of 1,4-butanediol, and 60 parts by weight of polytetramethylene ether glycol (average molecular weight: 1,000), E-1 was used. Ester TPE (polyester polyether block copolymer: polytetramethylene ether glycol content: 60 parts by weight, density: 1.11)
g / cm ³ , JIS-A hardness 89, MFR (245 ° C.,
2.16 kg load) 35 g / 10 min).

Ester TPE (E-5) E-1 was obtained by using 40 parts by weight of dimethyl terephthalate, 25 parts by weight of 1,4-butanediol, and 60 parts by weight of polytetramethylene ether glycol (average molecular weight: 2,000). Ester TPE (polyester polyether block copolymer: polytetramethylene ether glycol content: 60 parts by weight, density: 1.11)
g / cm ³ , JIS-A hardness 89, MFR (245 ° C.,
2.16 kg load) 32 g / 10 min).

Ester TPE (E-6) Using 48 parts by weight of dimethyl terephthalate, 27 parts by weight of 1,4-butanediol, and 50 parts by weight of polytetramethylene ether glycol (average molecular weight: 1,000), E-1 was used. Ester-type TPE (polyester polyether block copolymer: polytetramethylene ether glycol content: 50 parts by weight, density: 1.14)
g / cm ³ , JIS-A hardness 94, MFR (245 ° C.,
2.16 kg load) 32 g / 10 min).

Ester TPE (E-7) Using 54.4 parts by weight of dimethyl terephthalate, 30 parts by weight of 1,4-butanediol, and 42 parts by weight of polytetramethylene ether glycol (average weight molecular weight: 1,000), In the same manner as in Example 1, ester TPE (polyester polyether block copolymer: polytetramethylene ether glycol content 42 parts by weight, density 1.1
7 g / cm ³ , JIS-A hardness 97, MFR (245
° C, 2.16 kg load) 30 g / 10 min).

Amide TPE (A-1) Pebax 2533 hardness 76 manufactured by Toray Industries, Inc. Amide TPE (A-2) Pebax 4033 hardness 97 manufactured by Toray Co., Ltd. Urethane TPE (U-1) Nippon Milactran ( Milactran E185 hardness 85 Urethane-based TPE (U-2) manufactured by Nippon Milactran Co., Ltd. Milactran E195 hardness 85 Styrene-based TPE (S-1) manufactured by Mitsubishi Chemical Corporation Lavalon SJ7400 hardness 75

The details of the non-olefinic thermoplastic resin composition used for the support base of the examples are described below. Polycarbonate Resin Composition (C-1) 30 parts by weight of a polycarbonate resin (NOVAREX 7025A manufactured by Mitsubishi Engineering-Plastics Co., Ltd.) having a fiber diameter of 15 μm and a fiber length of 6 mm, surface-treated with a silane coupling agent of 30 parts by weight. Were melt-kneaded using a twin-screw kneading extruder. The flexural modulus of this composition according to JIS-K7203 is 69,000.
kg / cm ² .

Polycarbonate resin composition (C-2) 30 parts by weight of the above-mentioned ester-based TPE (E-4) was mixed with 70 parts by weight of a polycarbonate resin (NOVAREX 7025A manufactured by Mitsubishi Engineering-Plastics Corporation), and Melt kneading was performed using a shaft kneading extruder. The flexural modulus of this composition according to JIS-K7203 is 14,00.
It was 0 kg / cm ² .

Next, using the materials shown in Table 1, samples for evaluation of the CD-ROM turntable shown in FIG. 1 were prepared in the following manner. The above polycarbonate resin composition was injection molded at a molding temperature of 280 ° C. and a mold temperature of 90 ° C. to obtain a turntable support base 3 shown in FIG. Further, the molded body was inserted into a mold, and the above-mentioned TPE was injection-molded from three gates provided at 120 ° intervals to thermally bond the soft ring 4 to the support base 3. In addition,
A yoke, a magnet, and the like are inserted into the ordinary turntable 1, but are omitted because they are not relevant to the evaluation in the present embodiment.

The dimensions of the turntable 1 are as follows. a = 30 mm b = 28 c = 26 d = 25.9 e = 15 f = 5 g = 3 h = 0.3 This turntable is on a soft body (receiving area 0.88 cm).
² ) A CD-ROM disc is carried, and the disc is pressed and held by a load from above. The details of the evaluation method are described below.

(Coefficient of Friction with Disk) The tester shown in FIG. 3 was used. That is, the end face of the CD-ROM disc (made of PC resin) crimped on the fixed turntable with a load 8 of 200 g is pulled by the load W. The load W was increased every 2 g, and the coefficient of static friction was obtained from the load at the time when the disk started to move.

(Adhesion to Disk) A CD-ROM disk (made of PC resin) was pressed on the obtained soft turntable under a load of 300 g (surface pressure: 340 g / cm ² ), and this was pressed at 70 ° C. and 50%. For 100 hours. Thereafter, the strength required for vertically removing the disk from the turntable was measured, and the sticking force was evaluated.

(Measurement of Surface Accuracy) The surface of the turntable 1 is placed downward on a horizontal base, and the center hole 7
Then, the drive shaft 2 whose center was matched was vertically press-fitted.
Next, a load was applied in the direction in which the drive shaft 2 protruded, and the stress at which the drive shaft began to move was measured to obtain a removal force. The size of the hole 7 was set so that the removal force of the drive shaft at this time was 10 kg or more. After that, CD-RO on the turntable
The flatness of the upper portion of the elastomer was measured using the drive shaft mounted with the M disk and press-fitted as a reference axis, and the surface accuracy was determined. For the measurement of the flatness, five samples were measured using a roundness shape measuring device Roncom 40A manufactured by Tokyo Seimitsu Co., Ltd. The results of the measurement are shown in Tables 1 to 3.

[0050]

[Table 1]

[0051]

[Table 2] * Material destruction

[0052]

[Table 3]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an information medium turntable as an example of a component to which the present invention is applied.

FIG. 2 is a partial longitudinal sectional view of a soft body part.

3A and 3B are diagrams showing a method for measuring a coefficient of friction with respect to a disk, wherein FIG. 3A is a longitudinal sectional view, and FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electronic component (turntable for information media) 3 Support body (rotary base) 4 Soft body (soft ring) 5 Information recording medium

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Ikuo Mizuno 3-17 Ojida, Yokkaichi-shi, Mie Pref. Yuka Electronics Co., Ltd.

Claims (6)

[Claims] 1. A thermoplastic elastomer comprising one or more selected from an ester elastomer and an amide elastomer, having a flexural modulus of 15,000 kg /
A soft body-bonded electronic component characterized by being thermally fused to a non-olefin-based thermoplastic resin support having a size of at least ² cm ² . 2. The electronic component according to claim 1, wherein the electronic component is a turntable for an information disk. 3. The thermoplastic elastomer has a JIS hardness of 8
The soft body-bonded electronic component according to claim 1, wherein the number is 0 or more. 4. A thermoplastic elastomer comprising an ester elastomer, wherein the content of the soft component of the ester elastomer is 70 parts by weight or less.
The soft body-bonded electronic component according to any one of the above. 5. The soft-body-bonded electronic component according to claim 1, wherein the soft component of the ester elastomer comprises a polyether, and the polyether has a weight average molecular weight of 2,000 or less. 6. The electronic component according to claim 1, wherein the non-olefin-based thermoplastic resin is a polycarbonate resin.