JPH09263645A - Hinge part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lightweight hinge part having extremely excellent hinge characteristics by compounding a thermoplastic polyester resin with an epoxy group-modified polypriopylene resin in a specific ratio. SOLUTION: A composition comprising (A) 100 pts.wt. of a thermoplastic polyester resin (especially preferably polybutylene terephthalate), (B) 3-100 pts.wt. of an epoxy group-modified polypropylene resin, and preferably further (C) <=100 pts.wt. of a thermoplastic resin such as a polyolefin, polystyrene or acrylonitrile-styrene copolymer is molded. The component B is obtained e.g. by melt-blending an epoxy group-containing monomer (e.g. glycidyl methacrylate) with polypropylene resin and a radical polymerization initiator such as a peroxide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hinge component which is lightweight and has excellent hinge characteristics. More specifically, it relates to a hinge component having a composition in which a thermoplastic polyester resin is mixed with an epoxy group-modified polypropylene resin. The hinge parts referred to here are, for example, FIGS.
And a thin portion to which a bending or bending load is applied one or more times in a certain part of the component is referred to as a hinge (shown in FIGS. 1 and 2). The hinge shape is not particularly limited, and may be a sheet shape, a band shape, a string shape, or the like. The thickness and length of the hinge are not specified, and those substantially having a function as a hinge are included in the hinge component of the present invention. In addition, the hinge characteristic in the present specification is defined as the durability of the hinge as described above against one or more bending or bending loads.

[0002]

2. Description of the Related Art Thermoplastic polyester resins represented by polyethylene terephthalate and polybutylene terephthalate are excellent in processability, mechanical properties, and other physical and chemical properties. Widely used in the fields of automobile parts, electric parts, electronic parts, and other precision parts. In these fields, in addition to the excellent properties of the thermoplastic polyester resin, more special properties are often required in accordance with the higher functionality of the parts in which the thermoplastic polyester resin is used. One of the special characteristics required for such a thermoplastic polyester resin is hinge characteristics. In particular, in recent years, there is a growing demand for cost reduction by reducing the number of parts, which makes it easier to assemble parts at a low cost by integrating several parts with a hinge. In addition, a hinge part that can be used at low temperatures, or one that cannot have a stronger hinge shape due to the structural reason of the part, or
Of course, weight reduction as a material is required for further weight reduction, and further, there are many strict requirements such as thin-walled hinge property. However, general thermoplastic polyester resin materials cannot sufficiently satisfy the requirements for these hinge characteristics. Therefore, a thermoplastic polyester resin that is lightweight and has excellent hinge properties is strongly desired. As a method for satisfying such a demand, a method of adding a rubber-like substance, for example, a polyolefin-based elastomer to a thermoplastic polyester resin to improve hinge characteristics is known. Although this method is also effective in improving the hinge property to some extent, it does not always provide a sufficient effect, and has the drawback that the original properties of the polyester resin, such as strength and rigidity, are reduced. On the other hand, the polymer alloy method of adding another resin has been confirmed to have the effect of improving the hinge characteristics, but peeling and deterioration of physical properties occur due to lack of compatibility with polyester resin, or the heat resistance of the added resin is poor. In addition, due to deterioration of long-term heat deterioration characteristics, deterioration of high-temperature rigidity, etc., it has not been used as a material for practical use.

[0003]

The inventors of the present invention have conducted extensive studies to solve this problem, and as a result, a composition obtained by blending a thermoplastic polyester resin with an epoxy group-modified polypropylene resin is superior to the polyester resin. The inventors have found that it is possible to obtain a molded product that maintains the above various characteristics and has excellent hinge characteristics, and has completed the present invention. That is, the present invention
The present invention relates to a hinge part formed by molding a composition in which 100 parts by weight of a thermoplastic polyester resin (A) is mixed with 3 to 100 parts by weight of an epoxy group-modified polypropylene resin (B). Further speaking, although the composition itself as described above is known, it is quite unexpected and surprising that such composition significantly improves the hinge property, and the result of intensive studies by the present inventors. The present invention was first achieved by finding such a fact.

[0004]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the components of the present invention will be described in detail. First, the thermoplastic polyester resin (A) used in the present invention is a polyester obtained by polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound or polycondensation of a mixture of these three components, The effect of the present invention is exerted on both homopolyester and copolyester. Examples of the dicarboxylic acid compound used here include known dicarboxylic acids such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid and sebacic acid. And alkyl, alkoxy or halogen substitution products thereof. These dicarboxylic acid compounds can also be used for polymerization in the form of a derivative capable of forming an ester, for example, a lower alcohol ester such as dimethyl ester. It is also possible to use two or more of these dicarboxylic acids. Next, examples of the dihydroxy compound constituting the thermoplastic polyester resin (A) of the present invention are shown: ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hydroquinone, resorcin, dihydroxyphenyl, naphthalenediol,
Dihydroxy compounds such as dihydroxydiphenyl ether, cyclohexanediol, 2,2-bis (4-hydroxyphenyl) propane, and diethoxylated bisphenol A, polyoxyalkylene glycols, and their alkyl, alkoxy or halogen-substituted compounds.
One kind or a mixture of two or more kinds can be used. Examples of oxycarboxylic acids include oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid, and diphenyleneoxycarboxylic acid, and alkyl, alkoxy or halogen-substituted products thereof. Further, derivatives of these compounds capable of forming an ester can also be used. In the present invention,
One or more of these compounds are used. Also,
Besides these, trifunctional monomers, namely trimellitic acid,
It may be a polyester having a branched or crosslinked structure in which a small amount of trimesic acid, pyromellitic acid, pentaerythritol, trimethylolpropane or the like is used in combination. Also,
Add halogen compounds to aromatic nuclei such as dibromoterephthalic acid, tetrabromoterephthalic acid, tetrachloroterephthalic acid, 1,4-dimethyloltetrabromobenzene, tetrabromobisphenol A, tetrabromobisphenol A ethylene or propion oxide adducts. Also included are halogen-containing polyester copolymers with compounds having a substituent and having an ester-forming group. Further, a polyester elastomer constituting a block copolymer of a high melting point hard segment and a low melting point soft segment can also be used. Examples of the polyester elastomer include a block copolymer of a hard segment mainly composed of an alkylene terephthalate unit and a soft segment composed of an aliphatic polyester or polyether. In the present invention,
Any of the thermoplastic polyester resins produced by polycondensation may be used as the monomer component of the compound as described above, and may be used alone or in combination of two or more, preferably polyalkylene terephthalate, more preferably Polybutylene terephthalate and a polymer mainly containing polybutylene terephthalate are used, and the effect of the present invention is remarkable.

Next, the epoxy group-modified polypropylene resin (B) used in the present invention is as long as the epoxy group is bound to the polypropylene chain by a covalent bond,
Anything can be used. A polymer chain obtained by copolymerizing a monomer other than a propylene group can also be used, and examples thereof include a propylene-ethylene copolymer and a propylene-ethylene-diene copolymer. Moreover, it is also possible to mix and use these. Examples of the epoxy group-containing monomer component constituting the epoxy group-modified polypropylene resin (B) include glycidyl acrylate, glycidyl methacrylate, 4,5-epoxybenzyl acrylate,
Examples include 4,5-epoxybenzyl methacrylate, allyl glycidyl ether, methacryl glycidyl ether, butadiene monoepoxide, and the like, and glycidyl acrylate and glycidyl methacrylate are particularly preferably used. The amount of the epoxy-containing monomer added is preferably in the range of 0.1 to 15% by weight, more preferably 0.5 to 10% by weight, based on all the components. When the amount is too small, peeling and physical properties decrease due to insufficient compatibility with the component (A) polyester resin, and when the amount is too large, the melt viscosity of the polyester resin composition is remarkably increased to deteriorate moldability. Further, it is possible to copolymerize an aromatic vinyl compound in the epoxy group-modified polypropylene resin within a range not deteriorating the characteristics. For example, styrene, methylstyrene, vinyltoluene, vinylxylene, ethylbenzene, isopropylstyrene, chlorostyrene and the like can be used, and they can be used alone or in combination.

The method for producing the epoxy group-modified polypropylene resin is not particularly limited, but generally two methods are known. One of them is a method in which an epoxy group-containing monomer is mixed with a polypropylene resin and a radical initiator such as a peroxide, and the mixture is melt-mixed using a Banbury mixer or an extruder. The other method is a method in which an epoxy group-containing monomer, propylene and, if necessary, another olefin monomer are mixed and copolymerized. Examples of such a radical initiator include dicumyl peroxide, t-butylcumyl peroxide, 2,5-dimethylhexane-2,5-dihydroperoxide, di-
t-butyl peroxide, t-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxide) (Oxy) hexyne-3, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,3-dimethyl-2,3-diphenylbutane, 2,3-diethyl-2,3-
Diphenylbutane, 2,3-dimethyl-2,3-di (p-methylphenyl) butane, 2,3-dimethyl-2,3-di (bromophenyl) butane, etc. may be mentioned, and two or more of them should be used in combination. You can also The amount of the radical initiator added is 0.01 to 1.5 parts by weight, preferably 0.1 to 1.0 part by weight, based on 100 parts by weight of the polypropylene resin. When the amount of the radical initiator to be added is too small, the modification of the polypropylene resin becomes insufficient, the effect of improving the compatibility between the polyester and the modified polypropylene resin is small, and it is difficult to obtain the effect of the present invention. On the other hand, if it is excessively large, foaming may occur when the polypropylene resin is modified, which is not preferable. The addition amount of the epoxy group-modified polypropylene resin (B) used in the present invention is the thermoplastic polyester resin (A)
The amount is 3 to 100 parts by weight, preferably 5 to 90 parts by weight, more preferably 7 to 85 parts by weight, based on 100 parts by weight. If it is less than 3 parts by weight, the effect of adding polypropylene does not appear,
If the amount added exceeds 0 parts by weight, the fluidity and strength of the polyester resin composition may be deteriorated, which is not preferable.

Next, in the present invention, a thermoplastic resin (C) selected from polyolefin, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer, and polymethylmethacrylate is blended, if necessary. You can You may use these in mixture of 2 or more types. Further, a copolymer containing these thermoplastic resins as a main component can also be used. The addition amount of the third component thermoplastic resin (C) used in the present invention is 100 parts by weight or less, preferably 5 to 50 parts by weight, relative to 100 parts by weight of the thermoplastic polyester resin (A). In order to maintain the original moldability (flowability) of the polyester resin, it is desirable to add the necessary amount. Further, it is preferable to add 10 to 100% of the addition amount of the epoxy group-modified polypropylene resin (B).

In the resin composition of the hinge part of the present invention,
Substances that accelerate the reaction between the carboxylic acid terminal of the thermoplastic polyester resin and the epoxy group, such as phosphonium salts, 3
A small amount of an organic metal complex of a quaternary or quaternary amine, imidazole or a salt thereof may be added.

Further, in the composition for forming the hinge part in the present invention, it is possible to supplementarily use a small amount of a thermoplastic resin other than the above-mentioned component (C) within a range not impairing the purpose. For example, polyamide, polyacetal, polycarbonate, polyurethane, polyphenylene oxide, polyphenylene sulfide, polybutadiene, halogenated polyolefin, polyhalogenated vinyl, butyl rubber, multi-layer acrylic core shell rubber, etc. can be blended in any proportion depending on the purpose. .

The composition for forming the hinge part of the present invention is a known substance generally added to thermoplastic resins and thermosetting resins in order to impart desired properties according to the purpose, that is, Antioxidants, heat-resistant stabilizers, stabilizers such as UV absorbers, antistatic agents, colorants such as dyes and pigments, lubricants, plasticizers and crystallization accelerators, crystal nucleating agents, flame retardants, flame retardant aids. Of course, it is also possible to mix such.

In addition, in the hinge part composition of the present invention, an inorganic or organic fibrous reinforcing material,
It is also possible to mix an inorganic filler. Examples of the fibrous reinforcing material include glass fibers, carbon fibers, ceramic fibers, boron fibers, potassium titanate fibers, general inorganic fibers such as asbestos, and organic fibers such as aramid fibers.
As the inorganic filler, calcium carbonate, highly dispersible silicate, alumina, aluminum hydroxide, talc, clay,
Mica, glass flakes, glass powder, glass beads, quartz powder, silica sand, wollastonite, carbon black, barium sulfate, calcined gypsum, silicon carbide, alumina, powdered and granular substances such as boron nitrite and silicon nitride, plate-like inorganic Compounds and the like are included. These inorganic fillers may be used alone or in admixture of two or more, if necessary.

The composition used for molding the hinge part of the present invention can be easily prepared by known equipment and methods generally used as conventional resin composition preparation methods. For example, i) a method of mixing the respective components, kneading and extruding with an extruder to prepare pellets, and then molding, ii) once preparing pellets having different compositions, and mixing the pellets in a predetermined amount to mold Any method such as a method of obtaining a molded article having a desired composition after molding and iii) a method of directly charging one or more of each component into a molding machine can be used. Mixing and adding a part of the resin component as a fine powder with other components is a preferable method for uniformly blending these components.

If the filler or the like does not hinder the reaction between the polyester resin and the epoxy group-modified polypropylene, these are added at any time before or during the reaction to give a desired composition. It is also possible to obtain.

The hinge part made of the resin composition of the present invention exhibits excellent hinge characteristics for any shape of hinge, and can be applied to various hinge parts. Specifically, it is optimal for pipe holders for automobiles, electric wire holders for automobiles, connectors for automobiles, cases and holders for various parts, connectors in the electrical and electronic fields, caps in the field of miscellaneous goods, and the like.

[0015]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.
The evaluation method is as follows.

The specific gravity was measured according to the method of ASTM D-792 using an injection molded product (13 × 13 × 3 mm). The hinge characteristics were evaluated by injection-molding hinge test pieces of two types of shapes (M type and V type) shown in FIGS. 1 and 2, and evaluating the hinge type test pieces based on the following criteria. Number of samples: n = 10 Test method: After leaving the test piece sample at -20 ° C for 24 hours or more, bend the hinge part once at an angle of 180 ° C under the same condition. Next, this test piece sample is tested at 23 ° C. and 50% R
It was left under H for 48 hours, and then the tensile strength of the hinge part was measured. The strength of the hinge portion (hinge property) in each material in this test is shown as a ratio (% retention) to the tensile strength of the untreated hinge molded product. It is shown that a material having a higher retention rate has a higher hinge characteristic. Production Example 1 (Production of epoxy group-modified polypropylene) 100 parts by weight of polypropylene (PP) (Noblene manufactured by Sumitomo Chemical Co., Ltd.), 5 parts by weight of glycidyl methacrylate, and 2,5-dimethyl-2,5- Di (t-butylperoxy) hexane was added to PP at 0.15
Parts by weight were added and premixed for 5 minutes with a Henschel mixer. The obtained mixture was supplied to an extruder and melt-kneaded at a temperature of 200 ° C. to obtain epoxy group-modified polypropylene pellets.

Example 1 100 parts by weight of polybutylene terephthalate [manufactured by Polyplastics Co., Ltd., trade name: Duranex] and 10 parts by weight of the epoxy group-modified polypropylene of the above Production Example 1 were mixed, and a 30 mmφ twin-screw extruder was used. Was kneaded and extruded at 250 ° C. to prepare pellets. Next, the pellets were molded by an injection molding machine into hinge test pieces having two types of shapes as shown in FIGS. 1 and 2, and the hinge characteristics were evaluated.
Table 1 shows the characteristic evaluation results. Examples 2 to 3 Using 100 parts by weight of polybutylene terephthalate, the epoxy group-modified polypropylene of Production Example 1 described above in the amounts shown in Table 1, a hinge molded article was obtained in the same manner as in Example 1, and the hinge characteristics were evaluated. did. Example 4 To 100 parts by weight of polybutylene terephthalate, 10 parts by weight of the epoxy group-modified polypropylene of the above Production Example 1 and 10 parts by weight of polypropylene [Mitsui Petrochemical Co., Ltd., trade name: J300] as the third component were used. A hinge molded product was obtained by the same operation as in Example 1, and the hinge characteristics were evaluated. Example 5 Using 100 parts by weight of polybutylene terephthalate, 20 parts by weight of the epoxy group-containing polypropylene of Production Example 1 described above and 20 parts by weight of polypropylene as the third component were used to obtain a hinge molded product in the same manner as in Example 1. , Hinge characteristics were evaluated. Example 6 To 100 parts by weight of polybutylene terephthalate, 20 parts by weight of the epoxy-modified polypropylene of Production Example 1 described above and 20 parts by weight of an acrylonitrile-styrene copolymer [manufactured by Daicel Chemical Industries, Ltd.] as a third component were used. A hinge molded product was obtained by the same operation as in Example 1, and the hinge characteristics were evaluated. Comparative Example 1 A hinge molded product was obtained from polybutylene terephthalate by the same operation as in Example 1, and the hinge characteristics were evaluated. Comparative Example 2 Using 100 parts by weight of polybutylene terephthalate and 20 parts by weight of polypropylene, a hinge molded product was obtained in the same manner as in Example 1 and the hinge characteristics were evaluated.

Comparative Example 3 Using 100 parts by weight of polybutylene terephthalate and 10 parts by weight of ethylene ethyl acrylate [manufactured by Nippon Unicar Co., Ltd., trade name: NUC-6570] as an elastomer, hinge molding was carried out in the same manner as in Example 1. The product was obtained and the hinge characteristics were evaluated.

[0019]

[Table 1]

[0020]

As is clear from the results of Table 1, the hinge characteristics of the resin composition obtained by blending the thermoplastic polyester resin and the epoxy group-modified polypropylene resin are
It can be seen that it exhibits excellent hinge properties that cannot be obtained with the conventional thermoplastic polyester resin compositions. As described above, according to the present invention, it becomes possible to apply the thermoplastic polyester resin to a hinge component that requires strict hinge characteristics.

[Brief description of drawings]

FIG. 1 is a schematic view of an M-type hinge test piece whose hinge characteristics are measured, (a) is a side view, (b) is a plan view, and (c) is an enlarged view of a hinge portion. The unit of the numerical values in the figure is mm.

FIG. 2 is a schematic view of a V-type hinge test piece whose hinge characteristics are measured, (a) is a side view, (b) is a plan view, and (c) is an enlarged view of a hinge portion. The unit of the numerical values in the figure is mm.

Claims (4)

[Claims] 1. A hinge part formed by molding a composition in which 100 parts by weight of a thermoplastic polyester resin (A) is mixed with 3 to 100 parts by weight of an epoxy group-modified polypropylene resin (B). 2. In addition to the above components, the thermoplastic resin of the third component (C) is selected from polyolefin, polystyrene, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer and polymethylmethacrylate. 1 or 2 or more (A) component 100
The hinge part according to claim 1, which is formed by molding a composition in which 100 parts by weight or less are mixed with respect to parts by weight. 3. The hinge part according to claim 1, wherein the thermoplastic polyester resin (A) is polyalkylene terephthalate. 4. The hinge part according to claim 3, wherein the thermoplastic polyester resin (A) is polybutylene terephthalate.