JPH044130B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention is made of a thermoplastic elastomer in which one layer is flexible and scratch-resistant and has rubber elasticity and vibration-proofing performance, and the other layer is made of a thermoplastic resin with high rigidity and toughness.A metal part is inserted. This invention relates to multi-layer insert injection molded products. [Prior Art and Problems] Recently, many molded products in which metal parts are inserted into thermoplastic resin have been used. For example, home appliances,
It is often used in OA equipment, automobile parts, etc. The problem in this case is that, for example, when a small motor is fixed with bolts inserted into a thermoplastic resin base, it is necessary to insert vulcanized rubber as a gasket in order to improve vibration isolation. Furthermore, during molding or use, cracks may occur in the thermoplastic resin of insert molded products due to the inserted metal parts, which requires improvement. [Means for Solving the Problems] The present invention solves the above problems and provides a multilayer insert injection molded product made of a thermoplastic elastomer and a thermoplastic resin. Thermoplastic elastomers must have rubber elasticity and vibration-proofing properties, have excellent adhesion and compatibility with metals and thermoplastic resins, and have the best heat aging and weather resistance under the conditions in which the product will be used. Therefore, it is essential to use the specific elastomer described in the present invention. That is, the present invention provides (a) a polymer block A mainly composed of at least two vinyl aromatic compounds and a polymer block B mainly composed of at least one conjugated diene compound.
A modified hydrogenated block copolymer elastomer obtained by adding an organic carboxylic acid or a derivative thereof to a hydrogenated block copolymer obtained by hydrogenating a block copolymer consisting of a mixture of a polymer elastomer and a hydrogenated block copolymer elastomer; (b) a polyolefin resin, a polystyrene resin;
The present invention provides a multilayer insert injection molded product consisting of a thermoplastic resin selected from ABS resin, polyamide resin, polyester resin, polyacetal resin, modified PPE resin, etc., and (c) metal parts. In the present invention, the adhesion between the elastomer component (a) and the metal (c) is good and there is no possibility of peeling. or,
Since the adhesion between the (a) elastomer component and (b) thermoplastic resin component is strong, and the compatibility between the two is also good, it is possible to mix the scrap into the layer (b) again, which is economical. It was also extremely advantageous. Among the polymer components of the multilayer molded article of the present invention, component (a) or the hydrogenated block copolymer used as its raw material is a polymer block A mainly composed of at least two vinyl aromatic compounds. It is obtained by hydrogenating a block copolymer consisting of a polymer block B mainly composed of at least one conjugated diene compound, such as A-B-A, B-A-B-A, ( A-B
) _-4Si , a hydrogenated vinyl aromatic compound-conjugated diene compound block copolymer having a structure such as A-B-A-B-A. This hydrogenated block copolymer contains 50 to 60 vinyl aromatic compounds.
% by weight, preferably 10 to 50% by weight.Moreover, referring to the block structure, polymer block A mainly composed of a vinyl aromatic compound contains a vinyl aromatic compound polymer block or a vinyl aromatic compound containing 50% by weight. It has a structure of a copolymer block of a vinyl aromatic compound and a hydrogenated conjugated diene compound containing more than 70% by weight, preferably 70% by weight or more, and furthermore, a copolymer block mainly containing a hydrogenated conjugated diene compound. The polymer block B contains 50% by weight of a hydrogenated conjugated diene compound polymer block or a hydrogenated conjugated diene compound.
It has a structure of a copolymer block of a hydrogenated conjugated diene compound and a vinylaromatic compound containing more than 70% by weight, preferably 70% by weight or more. In addition, polymer block A mainly composed of these vinyl aromatic compounds and polymer block B mainly composed of hydrogenated conjugated diene compounds are composed of hydrogenated conjugated diene in the molecular chain of each polymer block. The distribution of the compound or vinyl aromatic compound may be random, tapered (in which the monomer component increases or decreases along the molecular chain), partially block-like, or any combination thereof, and the vinyl aromatic compound When there are two or more polymer blocks each consisting mainly of a hydrogenated conjugated diene compound, each polymer block may have the same structure, or may have a different structure. It may be hot. As the vinyl aromatic compound constituting the hydrogenated block copolymer, one or more kinds can be selected from, for example, styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene, etc. Among them, styrene is preferred. Further, as the conjugated diene compound before hydrogenation constituting the hydrogenated conjugated diene compound, for example, one type from butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, etc. Or two or more kinds are selected, and among them, butadiene, isoprene, and a combination thereof are preferred. The microstructure of the polymer block mainly composed of a conjugated diene compound before hydrogenation can be arbitrarily selected. For example, in the case of a polybutadiene block, the 1,2-microstructure is 20 to 20%.
50%, preferably 25-45%. Further, the number average molecular weight of the hydrogenated block copolymer used in the present invention having the above structure is 5000 to 5000.
1000000, preferably 10000 to 800000, more preferably 30000 to 500000, and the molecular weight distribution [weight average molecular weight () and number average molecular weight ()
The ratio (/)] is 10 or less. Furthermore, the molecular structure of the hydrogenated block copolymer may be linear, branched, radial, or any combination thereof. Any method for producing these block copolymers can be used as long as they have the structure described above. For example, special public relations
A vinyl aromatic compound-conjugated diene compound block copolymer is synthesized in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 23798, and then, for example, as described in Japanese Patent Publication No. 42-7804, The hydrogenated block donor polymer used in the present invention is obtained by hydrogenation in the presence of a hydrogenation catalyst in an inert solvent by the method described in JP-A-43-6636 or JP-A-59-133203. Can be synthesized. At this time, at least 88% of the aliphatic double bonds based on the conjugated diene compound of the vinyl aromatic compound-conjugated diene compound block copolymer are hydrogenated, and the polymer block mainly composed of the conjugated diene compound is transformed into an olefin. The compound can be converted into a polymer block. In addition, hydrogenation of aromatic double bonds based on vinyl aromatic compounds copolymerized into polymer block A mainly composed of vinyl aromatic compounds and, if necessary, polymer block B mainly composed of conjugated diene compounds. Although there is no particular restriction on the hydrogenation rate, it is preferable that the hydrogenation rate is 20% or less. The amount of unhydrogenated aliphatic double bonds contained in the hydrogenated block copolymer can be easily determined using an infrared spectrophotometer, nuclear magnetic resonance apparatus, or the like. Next, the modified hydrogenated block copolymer used as component (a) will be explained. 0.02 to 30 parts by weight, preferably 0.05 parts by weight of organic carboxylic acids and their derivatives such as maleic acid, itaconic acid, acrylic acid, acrylic esters, crotonic acid, fumaric acid, etc., are added to the hydrogenated block copolymer produced as described above. Addition of ~20 parts by weight yields a modified hydrogenated block copolymer. For the addition method, known means can be used. Specific manufacturing examples will be explained in Examples. As component (a), in addition to using the modified hydrogenated block copolymer elastomer alone, it is also possible to use the copolymer elastomer mixed with a hydrogenated block copolymer elastomer before modification. The mixing ratio is not particularly limited, but is selected in consideration of compatibility with the thermoplastic resin and adhesiveness with metal parts. A preferred range is that the mixing ratio of the hydrogenated block copolymer elastomer is 90% or less. Next, as for the thermoplastic resin used in the component (b) of the present invention, see "Polymer Analysis Handbook" edited by the Japan Society for Analytical Chemistry and the Polymer Analysis Research Council, Applied Edition 2, Plastics (page 225). Each of the resins listed can be used. Examples of polyolefins include (1) high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and modified polyethylene described in the polyethylene-based section on page 235 of the same, (2) polypropylene-based section B on page 249 of the same. polypropylene described in
Copolymers with ethylene and butene and modified polypropylene, (3) as described in the same, p. 244, paragraphs 2, 2, and 3.
EVA etc. are used. In addition, as polystyrene resin, polybutadiene or styrene-butadiene rubber containing 2 to 15% of
HIPS etc. are used. Furthermore, as ABS resins, various ABS and AES,
AAS that uses α-methylstyrene instead of styrene is also used. Polyamide resins include, for example, those described in "Plastic Materials Course 16" Polyamide Resins published by Nikkan Kogyo Shimbun, and refer to synthetic polymers with so-called acid amide bonds such as nylon 6, nylon 66, nylon 610, Nylon 11, nylon 12, copolymerized nylon 6, 66, 12, nylon 4, nylon 9, nylon 13, aromatic nylon,
Includes aromatic-aliphatic nylons. It also includes glass fiber-filled nylon and inorganic filler-filled nylon. Polyester resins are listed in the same series [10] Polyester resins published by Nikkan Kogyo Shimbun, for example, and are saturated polyester resins (PET).
Polybutyral resin (PBT) is a typical example.
Also includes PET and PBT containing glass fiber. Polyacetal resins are listed in the same series [13] Polyacetal resins, and include polyoxymethylene, which is a homopolymer of formaldehyde, a copolymer of formaldehyde and ethylene oxide, and those containing glass fibers. . The modified PPE resin consists of the following aromatic polyphenylene ether resin and reinforcing agent. That is, the aromatic polyphenylene ether resin has the general formula (R ₁ and R ₂ in the formula are non-sterically hindered carbon atoms with 1
~4 alkyl groups, aryl groups, halogen atoms,
Hydrogen atoms, etc., and these may be the same or different), or this structural unit and the general formula (R ₃ , R ₄ and R ₅ , R ₆ in the formula include non-sterically hindered alkyl groups having 1 to 4 carbon atoms, aryl groups, halogen atoms, hydrogen atoms, etc., and these may be the same or different. (Although R ₅ and R ₆ are not hydrogen atoms at the same time. Examples include merging. Resins that can be blended as reinforcing agents for aromatic polyphenylene ether resins include, for example, the general formula (R in the formula is a lower alkyl group or a halogen atom,
Z is selected from a lower alkyl group, a hydrogen atom, and a halogen atom, and p is an integer of 1 to 5. Examples include rubber-modified polymers, rubber-modified polymers, and the like. If necessary, the rubber may be made of a copolymer of the aromatic monovinyl monomer and at least one selected from other vinyl monomers, such as acrylonitrile, methyl methacrylate, and methacrylonitrile. Non-modified or rubber-modified polymers are also included. There are no particular limitations on the material and shape of the metal component used as component (c) of the present invention. Typical examples include bolts and metal cores made of iron, stainless steel, copper, brass, nickel, etc. Component (a), the block copolymer, may contain a thermoplastic resin, an inorganic filler, and a plasticizer, if necessary, in order to adjust the hardness and plasticity. The preferred blending amount is based on 100 parts of the block copolymer.
1 to 200 parts of thermoplastic resin, 1 to 300 parts of inorganic filler,
1 to 300 parts of plasticizer. More preferably, they are 1 to 150 parts, 1 to 250 parts, and 1 to 250 parts, respectively.
Most preferably 1 to 100 parts and 1 to 200 parts, respectively.
1 to 200 copies. Specific examples of thermoplastic resins, inorganic fillers, and plasticizers to be added to component (a) are listed below. Thermoplastic resins include polypropylene resin,
Examples include polyethylene resin, polystyrene resin, aromatic polyphenylene ether resin, and the like. Examples of inorganic fillers include titanium oxide, calcium carbonate, clay, talc, mica, bentonite, and the like. Plasticizers include paraffin oil, naphthenic oil, dibutyl phthalate, di-(-2 ethylhexyl) phthalate, di-(-2 ethylhexyl) adipate, diethylene glycol dibenzoate, butyl stearate, butyl epoxy stearate, tri- (2-ethylhexyl) phosphate and the like. Stabilizers, pigments, etc., which are general additives added to thermoplastic resin materials, can be appropriately added in the case of the present invention as well as conventional polymer resins. The ratio of component (a) and component (b) in the present invention can be arbitrarily selected depending on the use and shape of the product, but the preferred range is that component (a) is 3% to 90%, more preferably 5%. The percentage ranges from 80% to 80%. To mold the multilayer insert injection molded article of the present invention, an insert injection molding machine and a two-color injection molding machine are used alone or in combination. As the insert injection molding machine, a rigid system molding machine, that is, a composite automatic molding machine including pre-processing and post-processing, which is equipped with an automatic insert device and a product take-out device, is preferable. As the two-color injection molding machine, it is preferable to use one equipped with a general core back type mold, or a type called a DC type machine in which the mold rotates 180 degrees. [Effects of the Invention] As detailed above, the multilayer insert injection molded product of the present invention uses thermoplastic elastomer for one layer, so it is flexible, has excellent scratch resistance and vibration damping properties, and has excellent heat aging resistance and weather resistance. It is also excellent. On the other hand, since the other layers are made of thermoplastic resin, they have excellent rigidity and toughness. Further, the elastomer layer is firmly bonded to the thermoplastic resin layer and the metal parts. Therefore, the multilayer insert injection molded product of the present invention can be used for home appliances, office automation equipment,
It can be used in a wide variety of applications such as housings, boxes, gears, handles, chassis, panels, etc. as parts of automobiles. [Example] The present invention will be specifically described below with reference to Examples and Reference Examples, but the scope of the present invention is not limited thereto. The test method used in the Examples is as shown below. Hardness (Shore D): ASTM D2240 Hardness (Rockwell R): ASTM D785 Tensile strength: JIS K6301 Elongation: Same as above Izotsu impact strength: ASTM D746 Adhesive strength: JIS K6854 Cracks in metal insert: Visual inspection Vibration isolation of elastomer layer Properties: tanδ value determined by viscoelastic spectrometer Conditions: Room temperature Initial strain: 5% Dynamic strain: 100 μ Frequency: 15 Hz Sample shape: 4 mm x 2 mm x 30 mm Reference example Reference example of synthesis method for modified hydrogenated block copolymer 1 Modified hydrogenation Block copolymer (A) has a hydrogenated polybutadiene-polystyrene-hydrogenated polybutadiene-polystyrene structure, with a bound styrene content of 18% by weight and a 1,2-vinyl bond content in the polybutadiene portion before hydrogenation. 40%, number average molecular weight 56000, molecular weight distribution 1.40,
A hydrogenated block copolymer with a hydrogenation rate of 98% was published in 1983-
Synthesized using a Ti-based hydrogenation catalyst described in Publication No. 133203. Per 100 parts by weight of this hydrogenated block copolymer,
1 part by weight of maleic anhydride, 2,5-dimethyl-
2,5-di(tert-butylperoxy)hexane
0.1 part by weight was mixed and a modification reaction was carried out in a 50 mm diameter twin screw extruder set at 250°C. The obtained modified hydrogenated block copolymer contained 0.75 parts by weight of maleic anhydride. Reference Example 2 Modified hydrogenated block copolymer (B) Next, it has a structure of (polystyrene-hydrogenated polybutadiene) _-4Si , and the amount of bound styrene is
30% by weight, 1 of the polybutadiene part before hydrogenation
2-vinyl bond amount is 60%, number average molecular weight is 93000,
A hydrogenated block copolymer with a molecular weight distribution of 1.48 and a hydrogenation rate of 97% was synthesized using a Ti hydrogenation catalyst described in JP-A-59-133203. This hydrogen block copolymer
Per 100 parts by weight, 0.5 parts by weight of maleic anhydride, 0.1 parts by weight of dicumyl peroxide, and 0.2 parts by weight of magnesium hydroxide were mixed and heated at 230°C in a 40 mm diameter single screw extruder.
The denaturation reaction was carried out under the following temperature conditions. The obtained modified hydrogenated block copolymer had 0.16 parts by weight of maleic anhydride added thereto. Reference Example 3 Modified hydrogenated block copolymer (C) Furthermore, it has a polystyrene-hydrogenated polybutadiene-polystyrene structure, with a bound styrene content of 30% by weight, and a 1,2-vinyl bond in the polybutadiene portion before hydrogenation. Weight is 32%, number average molecular weight
44,000, a molecular weight distribution of 1.05, and a hydrogenation rate of 99%, a hydrogenated block copolymer was synthesized using a hydrogenation catalyst described in JP-A-59-133203. Per 100 parts by weight of this hydrogen block copolymer, 3.0 parts by weight of maleic anhydride,
0.3 parts by weight of n-butyl 4,4-bis(tert-butylperoxy)valerate was mixed, and a modification reaction was carried out at 260° C. in a 30 mm diameter twin screw extruder. The obtained modified hydrogenated block copolymer contained 2.1 parts by weight of maleic anhydride. Examples 1 to 3 Shear sea parts shown in FIG. 1 were molded using two TSD-SE type rigid insert injection molding machines manufactured by Nissei Plastics. Table 1 shows the type of thermoplastic resin and the performance of the molded product. The following composition was used for the elastomer layer.
90 parts by weight of modified hydrogenated block copolymer of Reference Example A (the same applies hereinafter), hydrogenated block copolymer 10 (bonded styrene 30%, vinyl content 35%, molecular weight 50,000), polypropylene resin 20, parfine oil 135, calcium carbonate 30. In the molding procedure, first, a bolt is fitted into a mold of one insert injection molding machine, and a thermoplastic resin is injection molded to obtain an insert molded product. Next, this molded article was taken out and transferred to a mold of a second insert injection molding machine, and the elastomer composition was subsequently injection molded and integrated to obtain a multilayer insert injection molded article.

[Table] Example 4 A multilayer insert injection molded product having exactly the same combination as in Example 2 was molded using a two-color injection molding machine equipped with a core back type mold manufactured by Nissei Plastics. In other words, ABS resin is injected from the primary side into a mold into which a metal bolt is inserted while the core is moving forward, then the core is moved back, and the elastomer composition is injection molded from the secondary side to form the final multi-layer insert injection. A molded product was obtained. The performance of the product obtained was equivalent to that of Example 2. Examples 5 to 7 Gear parts shown in FIG. 2 were molded using one TSD-SE type rigid insert injection molding machine manufactured by Nissei Plastics. Table 2 shows the type of thermoplastic resin and the performance of the molded product. The following reference example C is used as the elastomer layer.
A modified hydrogenated block copolymer was used alone. The molding procedure involved inserting a separately molded thermoplastic resin gear part and an iron core into a mold, and then injection-molding the elastomer into the gap between the two.

【table】

[Table] Examples 8 to 12 Identical molded articles were obtained in the same manner as in Example 5 except that the elastomer layer was of the type of Reference Example B and the modifier listed in Table 3 was used.

【table】 [Brief explanation of drawings]

FIG. 1 is a sectional view of a chassis component according to one embodiment of the present invention, FIG. 2A is a sectional view of a gear component according to another embodiment, and FIG. 2B is a perspective view thereof. 1... Thermoplastic resin layer, 2... Elastomer layer, 3... Brass bolt, 4... Iron core.

Claims (1)

[Scope of Claims] 1 (a) A block copolymer consisting of a polymer block A mainly composed of at least two vinyl aromatic compounds and a polymer block B mainly composed of at least one conjugated diene compound. A modified hydrogenated block copolymer elastomer obtained by adding an organic carboxylic acid or a derivative thereof to a hydrogenated block copolymer obtained by hydrogenation, or a hydrogenated block copolymer and the modified hydrogenated block copolymer elastomer. mixture with polymer elastomer and (b) polyolefin resin, polystyrene resin,
A multilayer insert injection molded product consisting of a thermoplastic resin selected from ABS resin, polyamide resin, polyester resin, polyacetal resin, and modified PPE resin and (c) metal parts. 2. The multilayer insert injection molded article according to claim 1, wherein the organic carboxylic acid or its derivative is maleic anhydride.