KR20160083644A - Polyoxymethylene Resin Composition and Molding Product Including the Same - Google Patents

Abstract

The present invention relates to a polyoxymethylene resin composition and a molded product formed of the resin composition. The polyoxymethylene resin composition comprises: a base resin including polyoxymethylene, which has the weight reduction less than or equal to 0.25% after heating the same for 10 to 30 minutes at the temperature in the range of 200-220°C; 1.0 to 3.0 parts by weight of aluminum flake, with respect to 100 parts by weight of the base resin; 0.1 to 0.5 parts by weight of polyhydric alcohol fatty acid ester; 0.1 to 0.5 parts by weight of an acrylate-styrene copolymer; and 0.05 to 0.5 parts by weight of a dihydrazide compound. Provided in the present invention is the polyoxymethylene resin composition, which can maintain material properties such as excellent mechanical strength and shock resistance.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyoxymethylene resin composition and a molded article comprising the same,

The present invention relates to a polyoxymethylene resin composition and a molded article produced using the same.

BACKGROUND ART Polyoxymethylene resin is known as a high-performance plastic having a balance of mechanical strength and impact resistance, and has been used in a wide range of fields such as electronic appliances and automobile parts. However, polyoxymethylene (polyoxy methylene) resin has a disadvantage in that formaldehyde is generated although the thermal decomposition reaction proceeds due to heat and frictional heat during extrusion or injection molding to an extremely small amount. Particularly, polyoxymethylene (polyoxy methylene) resin is used in combination with a pigment containing metal particles such as aluminum for the appearance of a luxurious metal feel of the final molded product. When such a metallic pigment is used, the polyoxymethylene resin Decomposition is further promoted, and the generation of formaldehyde is remarkably increased.

Formaldehyde generated during polyoxymethylene resin molding is closely related not only to the environmental hormone problem but also to the increase of the defective rate due to the contamination of the mold or the molding operation. It is therefore urgent to reduce the amount of formaldehyde generated in the production of molded articles using polyoxymethylene It is a challenge. Thus, as an additive for inhibiting formaldehyde generated from a polyoxymethylene resin, a nitrogen-based compound such as a melamine compound, a hydrazine compound, a urea compound, an amine compound or an amide compound has been conventionally examined.

In the prior art related to the inhibition of formaldehyde generation, Japanese Patent Laid-Open Publication No. 2012-92185 discloses a polyaluminum compound which improves the metallic feeling and weatherability and inhibits the formation of formaldehyde by containing aluminum particles, hindered amine light stabilizers, ultraviolet absorbers and formaldehyde- A polyoxy methylene resin composition is disclosed. Japanese Patent Application Laid-Open No. 2009-155418 discloses a polyoxy methylene resin composition which inhibits the generation of formaldehyde by specifying the amount of terminal groups of a polyacetal copolymer including a hemiformal terminal group , International Publication No. 2011-129445 proposes formaldehyde reduction and injection molding improvement using formaldehyde capturing agent.

However, there is a problem that it is difficult to say that the formation of formaldehyde is sufficient to suppress the generation of formaldehyde, and the flowability and the dispersibility can be lowered simultaneously with the reduction of formaldehyde. In addition, when a large amount of substantially aluminum particles are added, the flowability is deteriorated. Therefore, pyrolysis may occur due to frictional heat during extrusion processing, and flow marks are not easily dispersed during injection molding, There is a limit to improvement.

Accordingly, there is an urgent need to develop a polyoxy methylene resin composition having a metal texture and reduced formaldehyde generation as well as exhibiting excellent melt flowability and pigment dispersibility.

Accordingly, the present invention provides a polyoxymethylene resin composition capable of realizing sensitivity to metal rather than suppressing the generation of formaldehyde while improving physical properties such as excellent mechanical strength and impact resistance, And to provide a molded article produced by using the same.

A first preferred embodiment of the present invention for solving the above problems is a base resin comprising polyoxymethylene and having a weight loss of not more than 0.25% after heating at 200 to 220 ° C for 10 to 30 minutes; Based on 100 parts by weight of the base resin, 1.0 to 3.0 parts by weight of aluminum flake; 0.1 to 0.5 parts by weight of a polyhydric alcohol fatty acid ester; 0.1 to 0.5 parts by weight of an acrylate-styrene copolymer; And 0.05 to 0.5 parts by weight of a dihydrazide compound.

The base resin according to the first embodiment may further include 0.01 to 0.5 parts by weight of an alkali hydroxide hydroxide and 0.01 to 1 part by weight of a porous organic-inorganic hybrid silicate with respect to 100 parts by weight of the polyoxymethylene.

The aluminum flakes according to the first embodiment may have an average particle diameter of 10 to 30 mu m.

The polyhydric alcohol fatty acid ester according to the first embodiment may be at least one selected from the group consisting of glycerol monostearate, glycerol monobehenate and glycerol monomontane.

The acrylate-styrene copolymer according to the first embodiment may have a weight average molecular weight of 2000 to 4000.

The dihydrazide-based compound according to the first embodiment may be selected from dihydrazide oxalate, dihydrazide malonate, dihydrazide succinate, dihydrazide glutarate, dihydrazide Adipate, dihydrazide sebacate, dihydrazide dodecanedic acid, 1,18-octadecanedicarbohydrazide, dihydrazide maleate, dihydrazide fumarate, 7,11-octadecane Diene-1, 18-dicarbohydrazide, dihydrazide terephthalate, and mixtures thereof.

The polyoxymethylene according to the first embodiment may have a weight average molecular weight of 150000 to 300000 and a melting point of 165 ° C to 172 ° C.

A second preferred embodiment of the present invention is a molded article formed from the polyoxymethylene resin composition of the first embodiment.

(I) the amount of formaldehyde generated is not more than 1.5 ppm per 10 g of a molded product (chip basis) when stored in a closed space at a temperature of 140 ° C. for 30 minutes, or (ii) a sealed space At room temperature for 1 hour, the amount of formaldehyde generated may be ² ppm or less per 32 cm ² of the area of the molded article.

According to the present invention, it is possible to provide a polyoxymethylene resin having excellent dispersibility to an inorganic substance or pigment while maintaining physical properties such as excellent mechanical strength and impact resistance. As a result, not only the phenomenon of resin decomposition (formaldehyde generation) due to frictional heat during molding is reduced but also the flow mark is remarkably reduced, so that the appearance of metal-like appearance Can be produced.

FIG. 1 is a graph showing the relationship between a molded article (left) of a conventional polyoxymethylene resin in which a flow mark is generated due to poor flowability during injection molding, and a molded article of a polyoxymethylene resin produced in an embodiment of the present invention FIG.

According to one aspect of the present invention, there is provided a base resin composition comprising: a base resin containing polyoxymethylene and having a weight loss of not more than 0.25% after heating at 200 to 220 ° C for 10 to 30 minutes; Based on 100 parts by weight of the base resin, 1.0 to 3.0 parts by weight of aluminum flake; 0.1 to 0.5 parts by weight of a polyhydric alcohol fatty acid ester; 0.1 to 0.5 parts by weight of an acrylate-styrene copolymer; And 0.05 to 0.5 parts by weight of a dihydrazide compound can be provided.

Hereinafter, each component of the resin composition of the present invention will be described in more detail.

[Base resin]

The base resin of the present invention contains polyoxymethylene as a main component, wherein the polyoxymethylene is an oxymethylene homopolymer in which both ends of the polymer are blocked by an ester or an ether group, or in the polymer chain composed of oxymethylene monomer units, May be an oxymethylene copolymer in which an oxyalkylene unit having 2 to 8 carbon atoms is randomly inserted and both ends of the polymer are blocked with an ester or an ether group. In the present invention, the polyoxymethylene is not particularly limited as long as it is a commonly used polyoxymethylene, but it has a weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) of 150000 to 300000 and a melting point of 165 to 172 Lt; 0 > C.

The present invention is not particularly limited thereto, but the oxyethylene homopolymer and the oxymethylene copolymer may be prepared by the following method. First, the oxyethylene homopolymer is polymerized by introducing anhydrous formaldehyde into an organic solvent containing a basic polymerization catalyst such as organic amine, organic or inorganic tin compound or metal hydroxide, filtering the polymer, By heating in acetic anhydride in the presence of sodium to acetylate the end.

Further, the oxymethylene-based copolymer can be produced, for example, by reacting a cyclic oligomer of formaldehyde such as anhydrous trioxane or tetraoxane with a cyclic oligomer of ethylene oxide, propylene oxide, 1,3-dioxolane, , 1,4-butanediol formal, 1,5-pentanediol formal, 1,6-hexanediol formal, diethyleneglycol formal, 1,3,5-trioxepan, Is dissolved or suspended in an organic solvent such as cyclohexane or benzene and then added with a Lewis acid catalyst such as boron triflate diethyl etherate to polymerize and decompose to remove the unstable terminal .

In the present invention, it may be preferable to select an oxymethylene copolymer from the viewpoint of balance of heat resistance, mechanical strength and impact resistance. Here, the content of the oxyalkylene comonomer unit in the oxymethylene-based copolymer is preferably 0.1 to 10 moles per 100 moles of the oxymethylene monomer unit, more preferably 0.1 to 10 moles per 100 moles of the oxymethylene monomer unit from the viewpoints of improving the thermal stability of the oxymethylene- May be 0.1 to 7 mol, and more preferably 0.1 to 5 mol.

According to a preferred embodiment of the present invention, the base resin comprises 0.01 to 0.5 parts by weight of an alkali hydroxide hydroxide and 0.01 to 1 part by weight of a porous organic-inorganic hybrid silicate, based on 100 parts by weight of polyoxymethylene which is contained as a main component, The weight loss after heating at 200 to 220 ° C for 10 to 30 minutes may be 0.25% or less.

That is, it is preferable to use a polyoxy-methylene resin in which an alkaline hydroxide hydroxide and a porous organic-inorganic hybrid silicate are added to polyoxymethylene so that the thermal stability of the base resin is remarkably improved. At this time, the alkaline earth metal hydroxide may preferably be calcium hydroxide (Ca (OH) ₂ ), decomposing the metastable terminal and unstable terminal of the polyoxymethylene through the Kanizar reaction to generate formaldehyde , And enhances heat stability. In addition, porous organic-inorganic hybrid silicates capture low-molecular substances and capture substances that decompose polymers such as formic acid, thereby contributing to the inhibition of formaldehyde generation.

In the present invention, when the content of the alkaline earth metal hydroxide is less than 0.01 part by weight with respect to 100 parts by weight of polyoxymethylene, the unstable terminal can not be sufficiently decomposed to form a formaldehyde gas generating source at the subsequent injection. Decomposition may cause degradation of physical properties or cause discoloration of the polymer. If the content of the organic-inorganic hybrid silicate is less than 0.001 part by weight with respect to 100 parts by weight of polyoxymethylene, the adsorption of volatile organic compounds (VOCs) may be deteriorated. If the content is more than 1 part by weight, And the decomposition occurs due to the weak bonding force between the resin and the resin, the gas is released and foaming may occur, and the stability during the manufacturing process may be deteriorated.

In the present invention, the porous organic-inorganic hybrid silicate may be prepared by hydrolyzing 60 to 98% by weight of a silica precursor and 2 to 40% by weight of an organic silane in the presence of a surfactant, followed by dehydration and washing. The silica precursor may be at least one selected from the group consisting of an alkoxysilylalkylene having at least four alkoxy groups, a tetraalkylorthosilicate, and an alkoxysilylalkane having at least four alkoxy groups, and the organosilane may have one to three An alkoxy silane having an alkoxy group, an alkoxy silane silane, an alkoxy silane silane, and an alkoxyaralkyl silane. Also, by having pores of 50 nm or less and a surface area of 200 to 2000 m 2 / g, it is possible to capture low-molecular substances such as formic acid and VOCs to remove the substances causing discoloration.

[aluminum flake ]

In the present invention, an aluminum flake is added for the expression of color and luster such as a metal without being subjected to a painting process including painting, coating and the like. However, in the extrusion and injection molding of a resin, It is preferable to control the degree of dispersion and the particle size and content of the flakes.

In the present invention, the average particle size of the aluminum flakes is preferably 10 to 30 탆. If the particle size of the aluminum flake is less than 10 탆, the particle size is too small to have a sufficient gloss effect. If the aluminum flake exceeds 30 탆, the dispersibility is lowered and the aluminum flake tends to sag, ≪ / RTI >

The aluminum flakes may be added in an amount of 1.0 to 3.0 parts by weight based on 100 parts by weight of the base resin. When the content is less than 1.0 part by weight, a problem of metal texture and gloss is insufficient. When the content is more than 3.0 parts by weight, physical properties are lowered and the composition is not able to withstand external impact, There is a drawback that the cost is increased.

[Polyhydric alcohol fatty acid ester]

In the present invention, the polyhydric alcohol fatty acid ester improves the fluidity of the resin during extrusion, thereby reducing pyrolysis due to frictional heat, and consequently contributing to the reduction of formaldehyde. However, if the molecular weight is excessively increased, the compatibility may be lowered, the fluidity may be improved, and the lubricant improving effect may be insignificant. Therefore, the polyhydric alcohol fatty acid ester may have a molecular weight of 300 to 1000 in consideration of extrudability.

In the present invention, the polyhydric alcohol fatty acid ester may be one or more selected from the group consisting of glycerol monostearate, glycerol monobehenate, and glycerol monomontanate, 0.5 part by weight. If the content of the polyhydric alcohol fatty acid ester is less than 0.1 parts by weight, flowability upon melting may be lowered. If the content is more than 0.5 parts by weight, mold contamination due to reaction with formaldehyde may be increased.

[ Acrylate - Styrene  Copolymer]

In the present invention, the acrylate-styrene copolymer serves to improve the flowability at the time of injection and the dispersibility of the aluminum flakes, thereby reducing the occurrence of flow marks in the articles, Contributing. If the molecular weight is excessively low, it is difficult to add because of the liquid phase, and if the molecular weight is excessively large, the effect of improving the dispersibility may be insignificant. Therefore, the acrylate-styrene copolymer preferably has a weight average molecular weight of 2000 to 4000 .

The content of the acrylate-styrene copolymer in the present invention is preferably 0.1 to 0.5 parts by weight based on 100 parts by weight of the base resin. If the content in the acrylate-styrene copolymerization is less than 0.1 parts by weight, flowability and dispersibility deteriorate during injection molding. If the content is more than 0.5 parts by weight, compatibility may deteriorate and appearance quality may deteriorate.

[ Dehydrazide system ( dihydrazide ) Compound: Formaldehyde Capture agent ]

The resin composition of the present invention may contain 0.05 to 0.5 parts by weight of a dihydrazide compound as a formaldehyde capturing agent relative to 100 parts by weight of the base resin in order to minimize occurrence of formaldehyde which may occur during extrusion or injection molding have.

If the content of the dihydrazide compound is less than 0.05 part by weight, the efficiency of the porous organic-inorganic hybrid silica compound contained in the base resin for removing formaldehyde may be lowered or decomposition of the base resin may occur. On the other hand, when the content of the dihydrazide compound exceeds 0.5 parts by weight, contaminants are generated in the injection mold due to the reaction between the formaldehyde and the additives in the manufacturing process, The quality may be deteriorated.

In the present invention, the dihydrazide compound is selected from the group consisting of dihydrazide oxalate, dihydrazide malonate, dihydrazide succinate, dihydrazide glutarate, dihydrazide adipate, di Dihydrazide sebacate, dihydrazide dodecanedic acid, 1,18-octadecanedicarbohydrazide, dihydrazide maleate, dihydrazide fumarate, 7,11-octadecanediene-1, 18-dicarbohydrazide, dihydrazide terephthalate, and mixtures thereof, more preferably at least one selected from the group consisting of dihydrazide adipate, dihydrazide sebacate ( Dihydrazide sebacate, and Dodecanedioic acid Dihydrazide.

Accordingly, it is an object of the present invention to provide a process for producing a resin molded article excellent in metal texture of an injection-molded article itself, without requiring a painting process including painting, coating and the like, on the surface of the resin using the polyoxy methylene resin composition And excellent flow properties of the polyoxymethylene resin and excellent dispersibility with respect to the inorganic material or the pigment can significantly reduce the flow mark in the molded product, thereby realizing excellent surface gloss and appearance.

Particularly, in the resin molded article of the present invention, the amount of formaldehyde generated due to frictional heat during injection / extrusion molding is extremely reduced. The amount of formaldehyde is remarkably reduced when (i) the amount of formaldehyde generated is stored in a closed space of 140 ° C for 30 minutes, (Ii) the amount of formaldehyde generated is ² ppm or less per 32 cm ² of the molded article when it is stored in a closed space at 65 캜 for 2 hours and then left at room temperature for 1 hour .

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. These examples are for the purpose of illustrating the present invention more specifically, and the present invention is not limited thereto.

The components used in the examples of the present invention are as follows.

- Base resin: K300-1 (weight loss after heating for 30 minutes at 220 ℃ / Kolon plastic, 0.25% for weight loss), K300-2 (weight loss after heating at 220 ℃ for 30 minutes)

- Aluminum flake: NME020T2 (Toyo Aluminum)

- polyhydric alcohol fatty acid ester: Glycerol mono-behenate (GM-B, Kao Corporation)

-Acrylate copolymer: ADF1350 (BASF, Mw 2000-4000)

- Dihydrazide: Adipic acid dihydrazed (ADH, Nippon Fine Chemicals)

Example  One

2.1 parts by weight of an aluminum flake (NME020T2, TOYO aluminum), 0.2 part by weight of a polyhydric alcohol fatty acid ester (GM-B, Kao Corporation), an acrylate-styrene copolymer (ADF1350, BASF ) And 0.2 parts by weight of dihydrazide (ADH, manufactured by Nippon Fine Chemical Co., Ltd.) were melted and mixed through a twin-screw extruder at an extruder temperature of 180 to 200 ° C, and then extruded into chips. The polyoxymethylene resin prepared in a chip form was dried in a hot air drier at 130 ° C for 4 hours. A portion of the chip thus prepared was put into a heated screw extruder and heated to a temperature of 4 cm x 8 cm 0.3 cm injection specimen.

Example  2 to 9

The procedure of Example 1 was repeated except that aluminum flakes, polyhydric alcohol fatty acid esters, acrylate-styrene copolymers and dihydrazide were added to 100 parts by weight of the base resin in the ratios shown in Table 1 below To prepare a polyoxymethylene resin, and then chips and injection specimens were prepared.

Comparative Example  1 to 8

The procedure of Example 1 was repeated except that aluminum flakes, polyhydric alcohol fatty acid esters, acrylate-styrene copolymers and dihydrazide were added to 100 parts by weight of the base resin in the ratios shown in Table 1 below To prepare a polyoxymethylene resin, and then chips and injection specimens were prepared.

Comparative Example  9

Chips and injection specimens were prepared by applying the same method as in Example 1 except that K300-2 having a weight loss of 0.5% after heating at 220 占 폚 for 30 minutes as a base resin was used.

Property evaluation

The properties of the polyoxymethylene resin compositions prepared in Examples and Comparative Examples were measured by the following methods, and the results are shown in Table 2.

(1) Evaluation of metal texture: The metal texture and the surface gloss of the surface appearing in the injection specimen were divided into excellent (◯), normal (Δ) and poor (ⅹ).

(2) Evaluation of flow mark: The flow mark at the gate part of the injection specimen was divided into ◯, △, and ⅹ.

(3) Formaldehyde in the chips (FA, Formaldehyde): 10 g of the chips prepared in Examples 1 to 9 and Comparative Examples 1 to 9 were aged at 140 ° C for 30 minutes, and formaldehyde (FA) formaldehyde gas contents were measured.

(4) Formaldehyde content of the injection specimen: The injection specimen (4 cm x 8 cm x 0.3 cm) was placed in a 3 L no-odd stirrer bag, allowed to stand at 65 ° C for 2 hours, allowed to cool at room temperature for 1 hour, The formaldehyde gas content was measured using Z-300XP.

(4) Izod Impact Strength: The Izod Notched impact strength was measured using an impact tester after leaving the specimen at room temperature (23 ° C) and relative humidity of 50% for one day according to ASTM D256.

division
(Parts by weight) Base resin NME020T2 GM-B ADF 1350 ADH K300-1 K300-2 Example 1 100 2.1 0.2 0.3 0.2 Example 2 100 1.0 0.2 0.3 0.2 Example 3 100 2.1 0.2 0.3 0.2 Example 4 100 2.1 0.1 0.3 0.2 Example 5 100 2.1 0.5 0.3 0.2 Example 6 100 2.1 0.2 0.1 0.2 Example 7 100 2.1 0.2 0.5 0.2 Example 8 100 2.1 0.2 0.3 0.05 Example 9 100 2.1 0.2 0.3 0.5 Comparative Example 1 100 0.8 0.2 0.3 0.2 Comparative Example 2 100 4.0 0.2 0.3 0.2 Comparative Example 3 100 2.1 0.05 0.3 0.2 Comparative Example 4 100 2.1 0.6 0.3 0.2 Comparative Example 5 100 2.1 0.2 0.05 0.2 Comparative Example 6 100 2.1 0.2 0.7 0.2 Comparative Example 7 100 2.1 0.2 0.3 0.03 Comparative Example 8 100 2.1 0.2 0.3 0.6 Comparative Example 9 100 2.1 0.2 0.3 0.2

division Metal texture
(Visual evaluation) Flow mark
(Visual evaluation) Chip FA
(ppm) Psalm FA
(ppm) Impact strength
(Kg · cm / cm) Example 1 О О 0.7 0.8 7.5 Example 2 О О 0.5 0.7 7.6 Example 3 О О 1.3 1.7 7.0 Example 4 О О 1.0 1.3 7.7 Example 5 О О 0.5 0.4 7.3 Example 6 О О 0.7 0.8 7.6 Example 7 О О 0.6 0.7 7.4 Example 8 О О 1.1 1.4 7.7 Example 9 О О 0.3 0.5 7.6 Comparative Example 1 X О 0.6 0.8 7.7 Comparative Example 2 О Δ 2.5 4.5 5.7 Comparative Example 3 О О 2.1 4.1 7.5 Comparative Example 4 Δ Δ 1.3 1.6 7.6 Comparative Example 5 О X 0.8 1.0 7.7 Comparative Example 6 Δ Δ 0.7 0.9 7.8 Comparative Example 7 О О 3.1 6.3 7.6 Comparative Example 8 Δ X 0.2 0.4 7.6 Comparative Example 9 О О 3.0 5.4 7.5

As shown in Table 1, Comparative Example 1, which has a low aluminum flake content, is poorly evaluated in terms of metal texture, and Comparative Example 2, which is too high, causes flow marks due to the problem of flowability, resulting in decrease in mechanical strength and increase in formaldehyde generation I was concerned. In addition, as in Comparative Examples 3, 4, 7, and 8, when the content of the polyhydric alcohol fatty acid ester or dihydrazide is low or high, formaldehyde generation inhibiting effect is low. As in Comparative Examples 5 and 6, the acrylate / It was found that the dispersibility decreased and flow mark was generated. Further, in the case of Comparative Example 9 using the base resin having poor heat stability, the amount of formaldehyde generated was also measured to be high.

On the other hand, in Examples 1 to 9, the polyoxymethylene resin composition exhibited excellent metal texture, no flow mark, and excellent impact strength. In the case of Example 8 in which the content of dihydrazide was low, the amount of formaldehyde generation was relatively high as compared with the other Examples. However, in Comparative Example 2, 3 and 9 in which dihydrazide was added more than Example 8 . That is, in Examples 1 to 9, it was confirmed that the amounts of formaldehyde generation were significantly lower in both the chip and the specimen.

Claims (9)

A base resin comprising polyoxymethylene and having a weight loss of 0.25% or less after heating at 200 to 220 占 폚 for 10 to 30 minutes;
With respect to 100 parts by weight of the base resin,
1.0 to 3.0 parts by weight of aluminum flake;
0.1 to 0.5 parts by weight of a polyhydric alcohol fatty acid ester;
0.1 to 0.5 parts by weight of an acrylate-styrene copolymer; And
0.05 to 0.5 parts by weight of a dihydrazide compound.
[Claim 2] The method according to claim 1, wherein the base resin further comprises 0.01 to 0.5 parts by weight of an alkali hydroxide hydroxide and 0.01 to 1 part by weight of a porous organic-inorganic hybrid silicate, based on 100 parts by weight of the polyoxymethylene. Resin composition.
The polyoxymethylene resin composition according to claim 1, wherein the aluminum flakes have an average diameter of 10 to 30 mu m.
The polyoxymethylene resin composition according to claim 1, wherein the polyhydric alcohol fatty acid ester is at least one selected from the group consisting of glycerol monostearate, glycerol monobehenate, and glycerol monomontanate.
The polyoxymethylene resin composition according to claim 1, wherein the acrylate-styrene copolymer has a weight average molecular weight of 2000 to 4000.
The composition of claim 1, wherein the dihydrazide compound is selected from the group consisting of dihydrazide oxalate, dihydrazide malonate, dihydrazide succinate, dihydrazide glutarate, dihydrazide adi But are not limited to, fats, dihydrazide sebacate, dihydrazide dodecanedic acid, 1,18-octadecanedicarbohydrazide, dihydrazide maleate, dihydrazide fumarate, 7,11-octadecanediene -1, 18-dicarbohydrazide, dihydrazide terephthalate, and mixtures thereof. The polyoxymethylene resin composition according to claim 1,
The polyoxymethylene resin composition according to claim 1, wherein the polyoxymethylene has a weight average molecular weight of 150,000 to 300,000 and a melting point of 165 to 172 ° C.
A molded article formed from the polyoxymethylene resin composition according to any one of claims 1 to 7.
The molded article according to claim 8, wherein the molded article has (i) an amount of formaldehyde generated is not more than 1.5 ppm per 10 g of a molded product (chip basis) when it is stored in a closed space at a temperature of 140 캜 for 30 minutes, (ii) At room temperature for 1 hour, the amount of formaldehyde generated is ² ppm or less per 32 cm ² of the area of the molded article.

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