WO1997023563A1

WO1997023563A1 - Polyacetal resin composition

Info

Publication number: WO1997023563A1
Application number: PCT/JP1996/003688
Authority: WO
Inventors: Yasuyuki Fukute
Original assignee: Polyplastics Co., Ltd.
Priority date: 1995-12-25
Filing date: 1996-12-18
Publication date: 1997-07-03
Also published as: JP3281242B2; JPH09176444A

Abstract

A polyacetal resin composition appropriately usable in clips and hinges which has excellent clipping and hinging properties and an improved fluidity while sustaining the inherent mechanical and molding properties, toughness, etc. of polyacetal. The composition comprises (A) from 96 to 40 % by weight (based on the whole composition; the same will apply hereinafter) of a polyacetal resin, (B) from 3 to 50 % by weight of a core/shell polymer having the core made of a rubber-like polymer and the shell made of a glassy polymer, and (C) from 1 to 10 % by weight of a polyethylene resin.

Description

Specification

Polyacetal resin composition

TECHNICAL FIELD OF THE INVENTION

The present invention provides a method for attaching and locking a mating material to an article or part in an automobile or the like by utilizing elastic repulsion while maintaining the mechanical properties, friction and wear properties, moldability, and the like inherently possessed by the polyacetal resin. An object of the present invention is to provide a polyacetal resin composition which can be suitably used for a hinge which is a thin portion to which a clip or a part of a part is subjected to bending or bending load more than once.

[Prior art]

As is well known, polyacetal resin is used in an extremely wide range of fields as an engineering resin having excellent physical properties such as mechanical properties and electrical properties, or chemical properties such as chemical resistance and heat resistance. I have. In recent years, with the expansion of fields in which polyacetal resins are used, there may be cases where special properties are required for the materials.

Polyamide resins and polyacetal resins are used as clip plastic materials for attaching and locking articles or parts to mating materials using elastic repulsion in automobiles and other equipment and appliances. It is widely used. Polyamide resin materials are excellent in flexibility and impact resistance, and also excellent in clipping properties, making them suitable as clip materials.However, moisture absorption easily changes flexibility and impact resistance. However, it is necessary to pay attention to the environmental conditions (temperature, humidity, etc.) at the time of clip mounting, and the poor assembly workability poses a practical problem. On the other hand, those made of polyacetal resin have little change in physical properties such as impact resistance due to moisture absorption, but have the problem that the crib characteristics are inferior to those made of boriamid resin. Was.

In general, as a polyacetal resin for clip materials, a composition containing a thermoplastic polyurethane for the purpose of improving impact resistance is used, and although it has some desirable properties in terms of impact resistance, it is molded. Separation phenomenon of the polyacetal resin and thermoplastic polyurethane occurs on the surface of the product, causing a problem that the appearance of the molded product is remarkably impaired.Also, the thermal stability is reduced, and the strong elongation of the molded part is extremely low. Therefore, there are various problems such as a decrease in the degree of freedom in clip design, and improvements have been required. Further, in recent years, the functions required for clips have increased, and the shapes have become more complicated, and the thickness of molded products has been reduced for the purpose of cost reduction and weight reduction. Also, in order to improve productivity during clip injection molding, it is necessary to shorten the molding cycle and increase the number of dies that can be obtained by a single injection molding. Is done. In order to respond to such demands, it is necessary to improve the material's high fluidity, easy releasability, and heat stability during injection molding at high temperatures. use resin sets Narubutsu has not yet been provided ₃

In addition, with the expansion of the field where polyacetate resin is used, the development of a material with excellent flexibility, that is, a material with excellent hinge characteristics, is required as a property other than the clip characteristics required for the material. There are cases.

In particular, in recent years, there has been an increasing number of cases where it is desired to combine several parts with hinges and to assemble them easily and inexpensively because of the necessity of cost reduction by reducing the number of parts. There are many factors that degrade the hinge characteristics, such as the use under the above conditions or a structure that does not have a favorable hinge shape, and the demand for essentially excellent hinge characteristics is becoming more severe.

As a method of responding to the requirement of hinge characteristics, there is known a method of adding a thermoplastic urethane elastomer to a polyacetal resin to improve the hinge characteristics. With this method, it is possible to show an improvement in the hinge characteristics, but as described above, the blending of one component of the elastomer makes the exfoliation phenomenon more likely to occur on the molded product surface, and the appearance of the molded product is improved. There are various problems such as a significant loss of heat stability, a decrease in thermal stability, and a remarkable reduction in the elongation and elongation of the molded product and a decrease in flowability. There was a point, and improvement was required. The present invention provides a polyacetal resin composition having more excellent clip characteristics and hinge characteristics without impairing other physical properties, and a polyacetal resin clip part obtained by molding the composition. A hinge part is provided.

DISCLOSURE OF THE INVENTION

The present inventors have solved the above-mentioned problems without sacrificing the original properties of the polyacetal resin as much as possible, and have satisfied all the performances required as a resin composition for clips or a resin composition for hinges. To develop a polyacetal resin composition that can be used as a result of intensive research. It has been found that it is effective to add-and a specific polyethylene resin in combination, and the present invention has been completed.

That is, the present invention

(A) 96 to 40% by weight of polyacetal resin (to total composition)

(B) a core-shell polymer having a rubbery polymer core and a glassy polymer shell in an amount of 3 to 50% by weight (based on the total composition);

(C) Polyethylene resin 1 to 10% by weight (based on total composition)

And a polyacetal resin composition comprising:

The polyacetal resin composition of the present invention has a stable clip characteristic and high fluidity against environmental changes, a preferable clip insertion force, heat resistance during injection molding, and heat resistance, which have been difficult with the prior art. Since impact and good hinge properties can be achieved, it is a very suitable material as both a clip material and a hinge material.

As apparent from the above description and Examples, the polyacetal resin composition of the present invention, which is obtained by adding and blending a core-shell polymer and a polyethylene resin in combination with a polyacetal resin, has a well-balanced mechanical property of the polyacetal. While maintaining the properties, it exhibited excellent effects of maintaining excellent clip characteristics, fluidity, and hinge characteristics, and maintaining toughness and heat stability.

Examples of applications of parts obtained by molding such a polyacetal resin composition include various parts in the fields of automobiles, electricity, electronics, building materials, miscellaneous goods, and the like. It is preferably used.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the components of the present invention will be described in detail.

First, the (A) polyacetal resin used in the present invention is a polymer compound having oxymethylene groups (-CH2O-) as main structural units, and is a polyoxymethylene homopolymer, a copolymer having a small amount of other structural units in addition to oxymethylene groups. The polymer may be any one of a copolymer, a block copolymer, and a molecule having not only a linear but also a branched or crosslinked structure.

Next, the core-shell polymer (B) used in the present invention is a compound having a rubber-like polymer core and a glass-like polymer shell, and can be prepared by a known method. Commercial products can also be used. A typical example is the mouth —Mach Haas Acryloids KM330 and KM653; Kureha Chemical Co., Ltd. Paraloid CA-102 and KCA-301; Takeda Pharmaceutical Co., Ltd. Staphyloids P0-0270 and PO-0148; Kaneace FM of Chemical Industry Co., Ltd .; and Metaprene C-102, E-901, W-800, S-2001 of Mitsubishi Rayon Co., Ltd. Among such core-shell polymers, a core-shell polymer having a rubber-like polymer core and a glass-like polymer shell containing methyl methacrylate as a main component, particularly a core-shell polymer in which substantially no anion is detected, is preferred. One. When a core shell polymer in which anion is detected is used, decomposition of polyacetal may be promoted during melt-kneading or injection molding, and a desired clip characteristic may not be obtained. In addition, there are cases in which melting and kneading are impossible due to excessive decomposition. Here, the core-shell polymer in which anion is not substantially detected means a core-shell polymer in which anion is not detected in a usual qualitative test of anion. For example, as a measurement method, 5 g of a sample (core-shell polymer) is weighed in a 50 ml Erlenmeyer flask, 20 ml of ion-exchanged water is added, the mixture is stirred for 3 hours with a magnetic stirrer, and then with No. 5C filter paper. The filtered filtrate was divided into two parts, and 0.5 tnl of a 1% barium chloride aqueous solution was added to one of the two parts. A method of comparing and observing the occurrence of turbidity (qualitative test of sulfate ion) or the same treatment was performed. Instead, 0.1 N silver nitrate aqueous solution is added, and the presence of anion can be confirmed by a method of comparing the generation of turbidity (qualitative test of halogen ions). Preferably, a core shell polymer in which these aons are not present at all is suitably used.

A core-shell polymer that is preferable for use in the present invention is obtained by emulsion polymerization using a nonionic surfactant and a polymerization initiator in which a generated radical is neutral. Such a core-shell polymer can be produced, for example, by using an emulsion polymerization technique described in JP-A-3-14856. Emulsion polymerization can be carried out using, for example, the following surfactant and polymerization initiator. Examples of nonionic surfactants include ethers such as polyoxyethylene nouryl ether, polyoxyethylene stearyl ether, and polyoxyethylene lauryl ether, and esters such as polyoxyethylene monostearate. Widely used for molds, sorbitan ester type such as polyoxyethylene sorbitan monolaurate, block polymer type such as polyoxyethylenepolypropylene propylene block copolymer Most of the nonionic surfactants used can be used. The addition amount is appropriately selected according to the particle stabilizing ability of the surfactant. As the polymerization initiator, azobisisobutyronitrile, dimethyl 2,2'-azobisisobutyrate, 2,2'-azobis

(2-Aminopropane) Azo-based polymerization initiators such as dihydrochloride, peroxide-based polymerization initiators such as cumenehydroxide peroxyde, diisopropylbenzene hydroxoxide, and hydrogen peroxide are used alone or in combination of two or more. Are used in combination. When emulsification polymerization is performed in a reaction system that does not contain anion and a surfactant that is not a persulfate, a core-shell polymer that contains substantially no anion or contains a very small amount of anion is contained. can get. A polyacetal resin composition using such a core-shell polymer that does not substantially contain anion has excellent clip characteristics and hinge characteristics.

The core-shell polymer (B) used in the present invention has a rubber-like polymer core and a glass-like polymer shell. In the seed emulsion polymerization method, the polymer in the former stage is usually used in the latter stage. When the _three- core shell polymer obtained by the continuous multi-stage emulsion polymerization method in which the polymer of the present invention is successively coated has an intermediate phase described below, the polymer of the previous stage is put into the polymer of the previous stage. In some cases, an intermediate phase is formed by a multi-stage emulsification polymerization method in which water enters. At the time of the particle generation polymerization, it is preferable to start the emulsion polymerization reaction by adding a monomer, a surfactant and water to the reactor, and then adding a polymerization initiator. The polymerization of the first stage is a monomer constituting the _three rubbery polymer is a reaction to form a rubbery polymer, such as alkyl § chestnut rates or their number of carbon atoms of the conjugated diene or an alkyl group is 2-8 And the like. These monomers are polymerized to form a rubbery polymer having a glass transition temperature of preferably 30 ° C or lower. Examples of such a conjugated diene include butadiene, isoprene, and chloroprene. Examples of the alkyl acrylate having an alkyl group having 2 to 8 carbon atoms include, for example, ethyl acrylate, propynole acrylate, butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, and the like. Can be mentioned. In particular, butyl acrylate is preferably used as the rubber-like polymer. _{3 In} the first stage of polymerization, copolymerizable monomers such as conjugated gens and alkyl acrylates, for example, aromatic compounds such as styrene, vinyl toluene and α-methylstyrene are used. Group vinyl, aromatic It is also possible to copolymerize vinyl cyanide such as vinylidene, acrylonitrile and methacrylonitrile, and alkyl methacrylate such as vinylidene cyanide, methyl methacrylate and butyl methacrylate.

When the first-stage polymerization does not contain a conjugated diene, or even when it contains a conjugated diene, the total amount of all monomers in the first-stage is 20 wt. When the ratio is not more than / ₀ , a polymer having high impact resistance can be obtained by using a small amount of a crosslinking monomer and a grafting monomer. Examples of the cross-linkable monomer include aromatic divinyl monomer such as divinylbenzene, ethylene glycol resin acrylate, ethylene glycol resin methacrylate, butylene glycol monoacrylate, and hexanediol diacrylate. Hexanediol dimethacrylate, oligoethylene glycol diacrylate, oligoethylene glycol dimethacrylate, trimethyl methacrylate / repropane diacrylate, trimethylolpropane dimethacrylate, Bok Rimechirorupu Lono, ³ down Toriaku Li rate, there may be mentioned a preparative trimethylolpropane Torimetaku Li rate such alkanes polyol poly Accession Li rate or alkane polio one Ruporimetaku re, single bets, etc., especially Buchirenguri co one Le § click Li rate, hexane Jiorujiaku Re, single Bok is preferably used to. Examples of the daraftized monomer include, for example, unsaturated carboxylic acid aryl esters such as diaryl acrylate, aryl methacrylate, diaryl maleate, diaryl fumarate, and diaryl itaconate. Among them, aryl methacrylate is particularly preferably used. Such a crosslinkable monomer and a grafting monomer each occupy 0 to 5 weight of the total monomer amount in the first stage. / ₀ , preferably in the range of 0.1 to 2% by weight.

The core of this rubbery polymer weighs 50-90 of the core-shell polymer. /. Is preferred. When the weight of the core is less than this range or more than this range, the effect of improving the impact resistance of the resin composition obtained by melt-mixing the produced core shell polymer may not be sufficient. If the glass transition temperature of the core is higher than 130 ° C, the effect of improving the low-temperature impact resistance may not be sufficient. The outermost shell layer (shell phase) is formed of a glassy polymer. The monomer constituting the glassy polymer is methyl methacrylate, a mixture of monomers copolymerizable with methyl methacrylate, and a glassy polymer having a glass transition temperature of 60 ° C or higher.- Methyl methacrylate Examples of monomers copolymerizable with the acrylate include, for example, ethyl methacrylate. Alkyl methacrylate such as acrylate, butyl methacrylate, etc., alkyl acrylate such as ethyl acrylate, butyl acrylate, styrene, vinyl toluene, α-methyl styrene, etc., aromatic vinyl, aromatic vinylidene, Examples thereof include vinyl cyanide such as acrylonitrile and methacrylonitrile, and vinyl polymerizable monomers such as vinylidene cyanide.Ethyl acrylate, styrene, and acrylonitrile are particularly preferable. Are used. The outermost shell layer (shell phase) is Koashi Eruporima one entire 10-50 wt ⁰ /. Is preferable. When the amount of the seal phase is less than or greater than the above range, the effect of improving the impact resistance of the resin composition obtained by melt-mixing the formed core seal polymer may not be sufficient. Further, an intermediate phase may exist between the first stage and the final polymerization phase. For example, a polymerizable monomer having a functional group such as glycidyl methacrylate, methacrylic acid, or hydroxyshethyl methacrylate; a polymerizable monomer such as methyl methacrylate that forms a glassy polymer; An intermediate phase is formed by side emulsion polymerization of a polymerization monomer or the like that forms a rubbery polymer such as a rate. Such an intermediate phase can be selected variously depending on the desired properties of the core-shell polymer. Further, the polymerization ratio may be appropriately selected depending on the monomer used. For example, when a glassy polymer is used as the intermediate layer, its polymerization ratio may be calculated as a part of the shell, and when it is a rubbery polymer, it may be calculated as a part of the core.

The structure of the core seal polymer having such an intermediate phase is, for example, a multi-layer structure in which another layer exists between the core and the shell, or a structure in which the intermediate phase becomes fine particles in the core. Those having a dispersed salami structure can be mentioned. In a more extreme case of a core-shell polymer having a salami structure, the mesophase to be dispersed may form a new core in the center of the core. A core seal polymer having such a structure may occur when a monomer represented by styrene is used as a monomer constituting the intermediate phase. In addition, when a core-shell polymer having a medium phase is used, the impact resistance, the flexural modulus, the heat distortion temperature, the appearance (suppression of surface peeling and pearl luster, color tone due to refractive index change) are improved. Change) may be improved. The amount of the core-shell polymer (II) of the present invention relative to the total composition is 3 to 50% by weight, preferably 5 to 40% by weight, particularly preferably 5 to 30% by weight. If the amount of the core-shell polymer is too small, the necessary clip properties and hinge properties cannot be obtained, and even if added unnecessarily, mechanical properties, particularly rigidity, are greatly reduced.

By adding and blending the core-shell polymer (B) into the polyacetal resin, a material having good clip properties and hinge properties can be obtained without deteriorating the excellent mechanical properties of the polyacetal resin. ) Since the fluidity decreases in proportion to the amount of the core-shell polymer, the moldability of the polyacetal resin composition, that is, the fluidity required when injection-molding a thin-walled part is inferior. Therefore, the practical use range, product design, product shape, etc. were limited, and the good characteristics of polyacetate resin required for the material were not fully utilized. Therefore, the present invention is characterized in that a polyethylene resin (C) is further added to the above components (A) and (B), and the three components (A), (B) and (C) are added. The above-mentioned problems can be overcome without deteriorating the balanced properties inherent in the polyacetal resin by blending the polyacetal resin. It has been found that the material is effective for improving the clip insertion force and that the material has good hinge characteristics, so that it is possible to provide a preferable material for clip and hinge.

In the present invention, as the (0 polyethylene-based resin used for such purposes, an ethylene homopolymer such, or ethylene and professional propylene, butene one 1, ⁴ - polymethylpentene one 1, hexene one 1, Okuten one 1, nonene-11, decene-11, dodecene-11, etc., and copolymers with α-olefins, butyl esters, unsaturated carboxylic acids, unsaturated carboxylic esters, etc. Examples include low-density polyethylene, medium- to low-pressure method high-density, medium- and low-density polyethylene, ethylene-propylene copolymer, ethylene-butyl acetate copolymer, ethylene-acrylate copolymer, and the like. , Main chain, terminal or side chain, hydroxyl group, carboxyl group, amino group, glycidyl group, maleic anhydride The copolymer may be one or more selected from the group consisting of resins modified with functional groups such as groups, etc. Here, the copolymer is a random copolymer, a block copolymer, or a graft. Copolymers and mixtures thereof are also meant.

(C) Polyethylene resin has its melt index strength; ASTM D1238 (J IS IS67 As a value measured according to 60), a value of 1.0 to 250 gZ i0 min is preferable :: In particular, a value of 5.0 to i 50 g / 10 min is preferable:

Here, the ethylene-acrylate copolymer is an ester with an alcohol selected from the alcohol components alkyl alcohol and arylanol, and preferably has 1 to 4 carbon atoms. an alcohol having atoms include Mechinoreanoreko - Honoré, E Ji / Reanorekonore, n- Purohi Reanoreko one deviation, i - Pro Pino Les alcohol, _n - Buchinoreanoreko - le, 1 - Petit / Rearukonore, t Buchinorea alcohol, Are typical. All alcohol components in the molecule may be the same, some alcohols may be different alcohols, and some may be vinyl groups or hydroxyl groups. In particular, an ethylene-methyl acrylate copolymer and an ethylene-ethyl acrylate copolymer are preferred. Also, at that time, the weight ratio of ethylene to acrylate is preferably in the range of 1:10 to 10: 1, particularly preferably in the range of〗: 5 to 5: 1. The number average molecular weight of the ethylene-acrylate copolymer is preferably in the range of 1500 to 8000. When the number average molecular weight exceeds 8000, the effect of improving the fluidity is small, and when the number average molecular weight is less than 00, the solvent resistance and the mechanical strength decrease are not suitable.

(C) The amount of the polyethylene resin is 1 to 10% by weight based on the total composition. / o is appropriate, especially 2 to 8 weight. The preferred weight is 1. When the amount is less than / ₀ , the effect of improving clip characteristics and hinge characteristics is small, and the weight is 10%. /. If the amount is larger, the improvement effect reaches saturation, which may adversely affect the inherent properties of the polyacetal resin, and is inappropriate because the surface of the molded product may be peeled off.

Even if the (C) polyethylene resin is used alone in the polyacetal resin, a polyacetal resin composition having excellent clip properties and excellent impact resistance cannot be obtained. Therefore, the combination of the three components (発揮 + B + C) with the core-shell polymer (B) exerts a remarkable improvement effect, resulting in excellent clip properties, hinge properties, and impact resistance. The effect of having fluidity is recognized. The resin composition also has the effect of reducing the insertion force when assembling the clip, because the action of the polyethylene resin improves the slip on the surface of the molded article. This became a more preferable material in terms of work such as clip assembly.

The composition of the present invention may further include various known stabilizers to enhance thermal stability. Desirably, for this purpose, it is desirable to use one or more known antioxidants, nitrogen-containing compounds, alkali or alkaline earth metal compounds, or the like.

In order to further impart desired properties to the composition of the present invention according to the purpose, conventionally known additives such as a lubricant, a nucleating agent, a release agent, an antistatic agent and other surfactants, or components other than the component (C) One or more organic polymer materials, inorganic and organic fibrous, powdery and granular fillers, and plate-like fillers can be added and contained.

The composition of the present invention can be prepared by equipment and a method generally known as a method for preparing a synthetic resin composition. That is, the necessary components are mixed, kneaded using a single-screw or twin-screw extruder, extruded to form a pellet, and then molded, and the composition is prepared by a molding machine. It is also possible to carry out simultaneously with molding. In addition, in order to improve the dispersion and mixing of each component, a method in which a part or the whole of the resin component is pulverized, mixed, and melt-extruded to form a bellet can be used.

The compounds such as the stabilizers and additives may be added at any arbitrary stage, and may be added or mixed immediately before obtaining a final molded article.

The resin composition according to the present invention can be molded by any of extrusion molding, injection molding, compression molding, vacuum molding, blow molding, and foam molding, but generally, the crib is molded by injection molding. Is done.

[Brief description of the drawings]

FIG. 1 is a view showing the shape of a clip test piece used for evaluating the clip characteristics. FIG. 2 is a diagram showing an actual test situation of the evaluation of the clip characteristics.

FIG. 3 is a diagram showing an actual test situation of the evaluation of the clip input.

Fig. 4 is a schematic diagram of the test piece used for the hinge characteristic measurement, and (a), (b), and (c) show a plan view, a side view, and an enlarged view of the hinge portion, respectively. The other unit of the numerical value is sleep.

【Example】

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

In addition, the characteristic evaluation in the Example and the comparative example was performed according to the following method.

(1) Clip characteristics test

Using a pellet having the composition shown in Tables 1 and 2, a clip having the shape shown in Fig. 1 was prepared as follows. Then, as shown in Fig. 2, place it on a jig with a diameter of 7.0mni (at room temperature of 23 ° C and 50% RH) and a hole of 7.5 dragon (at -10 ° C) with a diameter of 7.0mni. A drop of lkg was dropped from a height of 3icm directly above it, and the clip was hammered into the hole. The number of sample breaks in the test samples (25) was examined, and it was determined that the smaller the number of breaks, the better the clip characteristics.

* Molding machine: J 75E P, manufactured by Japan Steel Works, Ltd.

* Molding condition :

Nozzle C 1 C 2 C 3

Cylinder temperature (° C) 200 190 180 160

Injection pressure 800 (kg / cm2)

Injection speed 0.3 (m / min)

Mold temperature 60 (° C)

Molding cycle Injection holding pressure 7 sec, cooling 9 sec

(2) Clip insertion force test

The clip insertion force test uses a clip formed in the same manner as the above-mentioned clip characteristic test, and as shown in Fig. 3, a 8.6 mm thick SUS416 sheet metallurgy with an 8.3 mm diameter hole is drilled. The test pieces were placed under the conditions of room temperature 23 ° C and 50% RH according to the test method specified in K7211-1976. The completion of the insertion of the test sample into the sheet metal jig is determined by whether or not all the flanges of the clip are in contact with the sheet metal jig.The weight of the weight and the drop height at which the clip is completely inserted are determined. From this, the clipping input energy was determined. It was determined that the lower the clip insertion force energy, the better.

(3) Method of measuring flowability (thin-wall flow length)

Using a pellet having the composition shown in Tables 1 and 2, a thin test piece (5 mm wide x 0.5 day thick) was molded using a molding machine set under the following conditions, and its flow length (filled with resin) (The maximum length: 50 mm). * Molding machine: Nissei P S20E

* Molding condition

Nosul C 1 C 2 C 3

Cylinder temperature (.C) 200 190 180 160

Injection pressure 1000 (kg / cm2)

(Injection speed 4.0 m / min)

Mold temperature 70 (.C)

(4) Izod impact strength

Using a let having the composition shown in Table 12, a test sample (a rectangular parallelepiped having a width of 12.7, a thickness of 6.4 mm and a length of 64 mm) was molded using an inline injection molding machine under the following conditions. A notch according to the above method was attached, and the Izod impact value was measured. The higher the Izod impact value, the better.

* Molding machine: Toshiba Corporation I S80E P N

* Molding condition ;

Nozore C 1 C 2 C 3

Cylinder temperature (° c) 200 190 180 160

Injection pressure 650 (kg / cm2)

Injection speed 4.0 (m / min

Mold temperature 80 CO

(5) Evaluation of hinge characteristics

Using Re' bets having the composition of Table 1 2, were molded test piece having a shape shown in FIG. 4 in the molding under the following conditions ₃

* Molding machine: Toshiba Corporation I S80E P N

* Molding condition :

Nozzle C 1 C 2 C 3

Cylinder temperature (C) 200 190 180 160

Injection pressure 650 (kg / cm2)

Injection speed 1.0 (m / min)

Mold temperature 80 (° C)

The hinge characteristics, based on the criteria shown below evaluated _c • Number of samples: n = 10

• Test method: After leaving the sample for at least 24 hours in an environment of —10 ⁼ C and 50% RH, the hinge part was repeatedly bent at the 180 ° angle 100 times under the same conditions. Evaluation A;

The number of broken hinge parts during 100 bends (smaller values are better). Evaluation B: The state of the hinge portion after bending 100 times was evaluated according to the following criterion and expressed as an average point (the larger the value, the better). 5: Almost no abnormality was recognized

: Fine cracks on the surface of the hinge

3: Growing cracks on the surface of the hinge and growing

2: Hinge cracks grow further toward the center and hinges become extremely thin 1: Thin hinges are cut and are about to be cut

0: fractured (6) Surface peel test

A cellophane tape was adhered to the surface of the 1 32 inch test piece, peeled off, and the peeling state was visually observed to evaluate the presence or absence of a surface layer peeling state.

Examples 1 to 9, Comparative Examples 1 to 18

Polyacetal resin (Λ) (Polyplastics Co., Ltd., Zyuracon (trade name)) is blended with core-shell polymer B_1 and polyethylene resin C-11 in the composition shown in Tables 1 and 2, and Henschel mixer is used. After mixing, the mixture was melt-kneaded using a 30-mni twin-screw extruder to prepare a pellet-shaped composition, and then a test piece was formed from this pellet using an injection molding machine under the above-described molding conditions. Tables 1 and 2 show the results of measuring and evaluating each characteristic.

In addition, the symbol of each component shown in the table | surface shows the following.

Polyacetal [Zyuracon (trade name) manufactured by Polyplastics Co., Ltd.]

A-1 melt index (190.C) 2.5 (g / lOmin)

A-2 Melt index (190 ° C) 9.0 (g / 10min)

A-3 Melt index (190 C) 14.0 (g / 10min)

Core seal polymer

B-1 Takefied Pharmaceutical Co., Ltd. Staphylode (trade name) PO-0148

B-2 Takefy Pharmaceutical Co., Ltd. Staphyloid (trade name) P0— 0143 Polyethylene resin, etc. c-1 Ethylene monoacrylate resin manufactured by Nippon Tunicer Co., Ltd.

NUC copolymer one (trade name) NUC6570 Echiruaku Li rate 25 ^_0/0 denatured

C-1 2 Ethylene monoacrylate resin manufactured by Nippon Tunicer Co., Ltd.

NUC copolymer (brand name) MB870 Ethyl atalylate 41% denaturation

C-3 polyethylene resin

HIZEX 5100B (trade name) C-1 polypropylene resin manufactured by Mitsui Petrochemical Industries, Ltd.

Hypol J700 (trade name) C'-2 thermoplastic polyurethane manufactured by Mitsui Petrochemical Industries, Ltd.

Eras Toranichi S80A (trade name) manufactured by Takeda Baichi Deshuretan Industry Co., Ltd.

Examples

1 2 3 4 5 6 7 8 9

(Α) Polyacetal type A-l A-2 A-3 Λ-2 Λ-2 A-2 A-2 A-2 A-2 Resin

75 75 75 75 75 75 78 72 87 m

(B) Core sil poly m m D-l D-l B-l B-2 D-l D-l B-l B-l B-l

Amount% 20 20 20 20 20 20 20 20 10 10

(0 Polyethylene type C-l C-l C-l C-l C-2 C-3 C-l C-l C-l Resin

Weight% 5 5 5 5 5 5 2 8 3 Clip characteristics / 23 ° C pieces 0 0 0 0 0 0 0 0 0

/ -10 ° C pieces 0 0 0 0 0 0 0 0 0 Clip input / 23 ° C j 0.74 0.70 0.78 0.72 0.71 0.72 0.77 0.69 0.80 Flowability 0.5mmtBF mm 39.2 46.1> 50 45.3> 50 47.9 45.9〉 50> 50

Wiii 擊 J / m 192 170 155 153 161 152 172 165 165 98

Hinge characteristics evaluation A 0 0 0 0 0 0 0 0 0 evaluation B 5 5 4.8 5 5 4.4 4.8 5 4.5 Surface peeling No No No No No No No No No No

Ratio * intersection f? 'L

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

(A) Class Al Al Al A-2 A-2 A-2 A-2 A-2 Λ-3 A-3 A-3 A-2 A-2 A-2 A-2 A-2 A-2 A -2 poly W ^

ffiS% 100 80 95 100 80 95 79.5 G5 100 80 95 80 95 95 92 90 75 90

(B) m ― B-l ― ― B-1 ― B-1 B 1 1 B-l 1 B-2 ― ― 1 B-1 B-1 1

Re

-20-1 20-20 20-20-20 1 1-10 20-

(0 n one-C-1 one C-1 C-1 C 1--C-1-C-2 C-3 C-1 one-1 C "-2

.J ^ h flu

Break% 1 ― 5 ― ― 5 0.5 15 ― 1 5 1 5 5 8 1 5 10 Crib characteristics / 23 pieces 16 0 20 17 0 17 0 22 25 0 25 0 1G 1G 25 9 0 G

/-10 ° C 25 0 25 25 0 25 0 25 25 0 25 0 25 25 25 25 0 15 Clip ^ input / 23'C j 1.22 0.87 1.20 1.25 0.89 1.12 0.84 0.G8 1.2G 0.94 1.22 0.88 1.22 1.09 1.11 1.09 0.71 1.01 mouth

0.5mntBF inn 41.2 36.1 44.3> 50 41.5> 50 42.8> 50> 50 50 50 40.1> 50> 50> 50> 50 48.3> 50

J / m GO 202 52 59 184 52 179 81 09 177 53 1G1 43 47 33 104 118 98

Κ

Hinge characteristics evaluation ASA 10 5 10 10 6 10 6 10 10 G 10 10 10 10 10 8 6 7 Evaluation B 0 2.6 0 0 2.1 0 2.3 0 0 2.1 0 0 0 0 0 0.6 1.5 0.9 None None None None None None None No No No No No M Yes

Claims

The scope of the claims

(A) 96-40 weight percent polyacetal resin. / o (vs. total composition) and

(B) A core shell polymer having a rubber-like polymer core and a glass-like polymer shell in an amount of 3 to 50% by weight. / ₀ (vs. total composition) and

(C) Polyethylene resin 1 to 10 weight ⁰ /. (Vs. total composition)

A polyacetal resin composition comprising:

2. The polyacetal resin composition according to claim 1, which is a core-shell polymer in which anion is not substantially detected.

The polyacetal resin composition according to claim 1, wherein the polyacetal resin composition is obtained by emulsion polymerization using a core-shell polymer (B), a nonionic surfactant, and a polymerization initiator in which a generated radical is neutral.

2. The polyacetal resin composition according to claim 1, wherein the shell of the core-shell polymer (B) is a polymer containing methyl methacrylate as a main component.

The polyacetano according to claim 1, wherein the polyethylene-based resin (C) is an ethylene acrylate copolymer, and the acrylate is an ester of an alcohol having 1 to 4 carbon atoms and acrylic acid. Resin composition.

The weight ratio of ethylene to acrylate is 1: L0 to 10: 1, and its melt index is 1.0 to 250 g / 10 min [ASTM D L238 ( The polyacetate resin composition according to claim 1, which is at least one member selected from the group consisting of ethylene acrylate copolymers (measured according to JI SK 6760).

A polyacetal resin clip part obtained by molding the polyacetal resin composition according to claim 1.

A hinge part made of a polyacetal resin obtained by molding the polyacetal resin composition according to claim 1.