JP2012057180A5 - Parts used for music, video or information equipment - Google Patents

Description

The present invention relates to a part for use in music, video or information equipment, including a polyacetal resin molded body with less formaldehyde generation, less warping of a molded product and excellent surface appearance.

An object of the present invention is to provide a part for use in music, video, or information equipment, including a polyacetal resin molded body that has a small amount of formaldehyde emission, reduces warping of a molded product, and has an excellent surface appearance.

As a result of intensive studies to achieve the above-mentioned problems, the present inventors have determined that 0.01 to 0.5 parts by mass of the hydrazide compound (B) and talc having a specific particle size (100 parts by mass) with respect to 100 parts by mass of the polyacetal copolymer (A). C) A resin obtained by molding a polyacetal resin composition containing 0.001 to 0.03 parts by mass and alkylene glycol (D) 0 to 5 parts by mass at a mold temperature of 60 ° C or higher and a resin temperature of 200 ° C or higher and 220 ° C or lower. The present inventors have found that a molded body can solve the above problems and have completed the present invention. That is, the present invention is as follows.
[1] Talc having 0.01 to 0.5 parts by mass of hydrazide compound (B) and an average particle size of 10 to 20 μm with respect to 100 parts by mass of polyacetal copolymer (A) having a melting point of 167 to 173 ° C. (C) A polyacetal resin composition containing 0.001 to 0.03 parts by mass and alkylene glycol (D) 0 to 5 parts by mass is molded at a mold temperature of 60 ° C or higher and a resin temperature of 200 ° C or higher and 220 ° C or lower. Parts for use in music, video or information equipment, including polyacetal resin moldings obtained by
[2] The component according to [1], wherein the hydrazide compound (B) is represented by the following general formula :
H ₂ NHNOC-R ⁵ -CONHNH ₂
(Wherein R ⁵ is a hydrocarbon having 2 to 20 carbon atoms);
[3] The above [1] or [2 ], wherein the hydrazide compound (B) is selected from the group consisting of sebacic acid dihydrazide, adipic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, and 2,6-naphthalenedicarbodihydrazide. ] Components described in the above;
[4] The component according to any one of [1] to [3], wherein the talc (C) is not surface-treated ;
[5] The part according to any one of [1] to [4] above , wherein the alkylene glycol compound (D) is polyethylene glycol ;
[6] The polyacetal resin composition comprises 100 parts by mass of the polyacetal copolymer (A), an antioxidant, a polymer or compound containing formaldehyde-reactive nitrogen, a formic acid supplement, a weathering (light) stabilizer, a release agent. The component according to any one of [1] to [5] above , containing 0.01 to 10 parts by mass of at least one selected from the group consisting of an agent and a lubricant ; and
[7] The component according to any one of [1] to [6], wherein an area of a thin portion of 1 mm or less of the polyacetal resin molded body is 2 cm ² or more .

According to the present invention, it is possible to provide a part for use in music, video or information equipment, including a polyacetal resin molded body that generates less formaldehyde, has less warpage of a molded product, and is excellent in surface appearance.

The present invention relates to 100 parts by mass of polyacetal copolymer (A), 0.01 to 0.5 parts by mass of hydrazide compound (B), 0.001 to 0.03 parts by mass of talc (C) having predetermined properties, and alkylene glycol (D) Music, video or information equipment, including a polyacetal resin molded product obtained by molding a polyacetal resin composition containing 0 to 5 parts by mass at a mold temperature of 60 ° C or higher and a resin temperature of 200 ° C or higher and 220 ° C or lower. It relates to parts used in

First, the polyacetal copolymer (A) will be described.

The polyacetal copolymer (A) used in the present invention is a polyoxymethylene copolymer.

Content of the hydrazide compound (B) in a polyacetal resin composition is 0.01-0.5 mass part with respect to 100 mass parts of polyacetal copolymers (A), Preferably it is 0.05-0.5 mass part, More preferably, it is 0.05-0.4 mass part. Within this range, the amount of formaldehyde released is small, and a resin molded article having an excellent surface appearance is obtained.

Content of talc (C) in a polyacetal resin composition is 0.001-0.03 mass part with respect to 100 mass parts of polyacetal copolymer (A), and 0.001 mass part or more from the point of thermal stability improvement. From the standpoint of maintaining the tensile elongation, it must be 0.03 parts by mass or less. Preferably it is 0.002-0.03 mass part, More preferably, it is 0.005-0.02 mass part.

The content of the alkylene glycol (D) in the polyacetal composition is preferably 0 to 5 parts by mass, more preferably 0 to 3 parts by mass, and still more preferably 0 to 0 parts by mass with respect to 100 parts by mass of the polyacetal copolymer (A). 2 parts by mass. When a small amount of alkylene glycol (D) is added, a resin molded article having an excellent surface appearance can be obtained, but when added in an amount exceeding this range, the surface tends to become rough.

The resin molded body of the present invention can be made into a resin molded body excellent in thermal stability by blending an appropriate additive depending on the application. Specifically, with respect to 100 parts by mass of the polyacetal copolymer (A) , (E) an antioxidant, a polymer or compound containing formaldehyde-reactive nitrogen, a formic acid scavenger, a weathering (light) stabilizer, a mold release (lubrication) 0.01-10 mass parts of at least 1 sort (s) of an agent can be contained.

Examples of the thermoplastic resin include polyolefin resin, acrylic resin, styrene resin, polycarbonate resin, and uncured epoxy resin. These modified products are also included. Examples of the thermoplastic elastomer include polyurethane elastomers, polyester elastomers, polystyrene elastomers, and polyamide elastomers. Examples of the pigment include inorganic pigments, organic pigments, metallic pigments, fluorescent pigments, and the like. Inorganic pigments are those commonly used for resin coloring, such as zinc sulfide, titanium oxide, barium sulfate, titanium yellow, cobalt blue, combustion pigments, carbonates, phosphates, acetic acid. It refers to salt, carbon black, acetylene black, lamp black and the like. Organic pigments include condensed azo, inone, furothocyanin, monoazo, diazo, polyazo, anthraquinone, heterocyclic, pennon, quinacridone, thioindico, berylene, dioxazine, phthalocyanine, etc. Or other pigments. Since the addition ratio of the pigment varies greatly depending on the color tone, it is difficult to clarify, but generally it is used in the range of 0.05 to 5 parts by mass with respect to 100 parts by mass of the polyacetal copolymer (A) .

The polyacetal resin composition of the present invention can be produced using a general extruder using the components described above. Examples of the extruder include a single-screw or multi-screw kneading extruder, and among them, a twin-screw extruder provided with a decompression device is preferable. As a method for producing the polyacetal resin composition,
<1> A method in which the polyacetal copolymer (A) is fed from the top of the extruder, and the hydrazide compound (B), talc (C) and alkylene glycol (D) are added from a side feed port by a quantitative feeder or the like and melt kneaded;
<2> A part of the polyacetal copolymer (A) is fed from the top of the extruder, and the hydrazide compound (B), talc (C), alkylene glycol (D) and the remaining polyacetal copolymer (A) are side-fed with a quantitative feeder or the like. A method of adding from the mouth and melt-kneading;
<3> Polyacetal copolymer (A), hydrazide compound (B), talc (C) and alkylene glycol (D) are mixed together using a Henschel mixer, tumbler, V-shaped blender, etc., and then melt kneaded using an extruder. And the like.

The hydrazide compound (B) and talc (C) are added to the molten state of the polyacetal copolymer (A) from the viewpoint of thermal stability of the obtained polyacetal resin composition and reduction of the amount of formaldehyde released <1>, <2> The production method is preferred. Furthermore, when adding (E) component, you may feed simultaneously with a polyacetal copolymer (A) from an extruder top, and you may feed simultaneously with a hydrazide compound (B) and talc (C) from a side feed port.

In the present invention, the polyacetal copolymer (A), hydrazide compound (B), talc (C), and alkylene glycol (D) are defined by the content in the polyacetal resin composition. Even in the body, the content is substantially equal. That is, the polyacetal resin molded product according to the present invention is a talc having a hydrazide compound (B) of 0.01 to 0.5 parts by mass and an average particle size of 10 μm to 20 μm with respect to 100 parts by mass of the polyacetal copolymer (A). (C) 0.001-0.03 mass part and alkylene glycol (D) 0-5 mass part are included.

The resin molded body of the present invention has excellent thermal stability, less formaldehyde generation, excellent mold deposit resistance, little warpage, and excellent surface appearance, so it is used for parts used in music, video or information equipment. Is possible. For example, cassette player, DAT, LD (Laser Disk) , [including the CD-ROM (Read Only Memory) , CD-R (Recordable), CD-RW (Rewritable) ] MD (Mini Disk), CD, DVD [Including DVD-ROM, DVD-R, DVD + R, DVD-RW, DVD + RW, DVD-R DL, DVD + R DL, DVD-RAM (Random Access Memory), DVD-Audio], Blu-ray Disc, HD-DVD, etc. It can be suitably used as a part used in music, video or information equipment represented by optical disk drives, MFDs, MOs, navigation systems, and mobile personal computers.

Hereinafter, the present invention will be described based on examples.
(1) Melting point measurement method for polyacetal copolymer Using a differential calorimeter (Perkin Elmer, DSC-7), the sample once heated to 200 ° C. and cooled was cooled to 100 ° C. and again 2.5 ° C./min. The temperature of the peak of the exothermic spectrum generated in the process of raising the temperature at a rate of was defined as the melting point.
(2) Method for measuring amount of formaldehyde released from molded product Using IS-80A injection molding machine manufactured by Toshiba Corporation, cylinder temperature: 205 ° C., injection pressure: (primary pressure / secondary pressure = 63.7 MPa / 50.0 MPa), injection time: 15 seconds, cooling time: 20 seconds, mold temperature: 77 ° C., a test piece (90 × 50 × 3 mm flat plate) was prepared, measured with a new Cosmos Electric Holctec, and molded product The amount of formaldehyde released from was determined.

The following components were used in Examples and Comparative Examples.
<Polyacetal resin a-1>
A biaxial self-cleaning type polymerization machine (L / D = 8) with a jacket capable of passing a heat medium is adjusted to 80 ° C., 4 kg / hr of trioxane, 42.8 g / liter of 1,3-dioxolane as a comonomer h (1.3 mol% with respect to 1 mol of trioxane), methylal as a chain transfer agent was continuously added at 0.1 × 10 ⁻³ mol with respect to 1 mol of trioxane. Further, boron trifluoride di-n-butyl ether was continuously added as a polymerization catalyst at 1.5 × 10 ⁻⁵ mol with respect to 1 mol of trioxane to carry out polymerization. The polyacetal copolymer discharged from the polymerization machine was put into a 0.1% aqueous solution of triethylamine to deactivate the polymerization catalyst. After filtering the deactivated polyacetal copolymer with a centrifuge, an aqueous solution containing choline formate (triethyl-2-hydroxyethylammonium formate) as a quaternary ammonium compound with respect to 100 parts by mass of the polyacetal copolymer. 1 part by mass was added and mixed uniformly and then dried at 120 ° C. The addition amount of the hydroxycholine formate was adjusted by adjusting the concentration of the hydroxycholine formate in the aqueous solution containing the added choline formate, and was 20 mass ppm in terms of the amount of nitrogen. The dried polyacetal copolymer is supplied to a vented twin screw extruder, and 0.5 parts by mass of water is added to 100 parts by mass of the melted polyacetal copolymer in the extruder, and the extruder set temperature is 200 ° C. The unstable terminal portion was decomposed and removed in a residence time of 7 minutes in the extruder. The polyacetal copolymer whose unstable terminal portion was decomposed was devolatilized under a condition of a vent vacuum of 20 Torr, extruded as a strand from the extruder die, and pelletized. The melting point of the polyacetal resin (A) thus obtained was 169.5 ° C.
<Hydrazide compound (B)>
b-1: Adipic acid dihydrazide (manufactured by Nippon Finechem Co., Ltd.).
b-2: Sebacic acid dihydrazide (manufactured by Nippon Finechem Co., Ltd.).
<Talc (C)>
c-1: MS (surface untreated) manufactured by Nippon Talc Co., Ltd. Average particle size of 15.6 μm.
c-2: (c-1) MS manufactured by Nippon Talc Co., Ltd., surface-treated with 1% aminopropyltriethoxysilane.
c-3: Nippon Talc Co., Ltd. P-3 (untreated surface) Average particle size 5.1 μm.
c-4: MS-KY (surface untreated) manufactured by Nippon Talc Co., Ltd. Average particle size of 24.5 μm.
<Alkylene glycol (D)>
d-1: Polyethylene glycol.
[Example 1]
To 100 parts by mass of the polyacetal resin (a-1), 0.3 parts by mass of triethylene glycol-bis- [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate] as an antioxidant and As a formic acid scavenger, 0.15 parts by mass of calcium distearate, 0.1 part by mass of hydrazide compound (b-1) and 0.005 parts by mass of talc (c-1) were added, and a 30-φ vented single screw extruder Was melt kneaded. The obtained polyacetal resin composition was molded into a plate-shaped product at a resin temperature of 210 ° C. (cylinder setting temperature of 205 ° C.) and a mold temperature of 80 ° C. using an injection molding machine, and formaldehyde emission and warpage were evaluated. Moreover, 3000 shot molding was performed, the surface appearance of the 3000th shot was evaluated, and the mold deposit amount adhering to the mold was observed. Furthermore, the tensile elongation was measured by ISO 527-1 & 2 (93), and the results are shown in Table 1.
[Examples 2 and 3]
Except for the amount of talc (c-1) added, the same operations as in Example 1 were performed for evaluation. The results are shown in Table 1.
[Example 4]
The same operations as in Example 1 were carried out for evaluation except that talc (c-1) was changed to (c-2). The results are shown in Table 1.
[Example 5]
Except for the amount of talc (c-2) added, the same operations as in Example 4 were performed for evaluation. The results are shown in Table 1.
[Examples 6 and 7]
The same operations as in Example 1 were performed except for the addition amount of the hydrazide compound (b-1). The results are shown in Table 1.
[Example 8]
Evaluation was performed by performing the same operations as in Example 2 except that the hydrazide compound (b-1) was changed to (b-2). The results are shown in Table 1.
[Example 9]
Evaluation was performed by performing the same operations as in Example 1 except that the resin temperature during molding was 220 ° C. (cylinder setting temperature 215 ° C.). The results are shown in Table 1.
[Example 10 ]
The same operations as in Example 2 were carried out for evaluation except that polyethylene glycol (d-1) was added. The results are shown in Table 1.
[Example 11 ]
Except for the addition amount of polyethylene glycol (d-1), the same operations as in Example 10 were performed for evaluation. The results are shown in Table 1.
[Comparative Example 1]
Evaluation was performed by performing the same operations as in Example 1 except that the hydrazide compound (b-1) and talc (c-1) were not added. The results are shown in Table 1 .
[Comparative Example 2]
Evaluation was performed by performing the same operations as in Example 1 except that talc (c-1) was not added. The results are shown in Table 1 .
[Comparative Example 3]
Evaluation was performed by performing the same operations as in Example 1 except that the resin temperature at the time of molding was 190 ° C. (cylinder setting temperature 185 ° C.). The results are shown in Table 1 .
[Comparative Example 4]
Evaluation was performed by performing the same operations as in Example 2 except that talc (c-1) was changed to (c-3). The results are shown in Table 1 .
[Comparative Example 5]
Except for the amount of talc (c-1) added, the same operations as in Example 1 were performed for evaluation. The results are shown in Table 1 .
[Comparative Example 6]
Evaluation was performed by performing the same operations as in Example 2 except that talc (c-1) was changed to (c-4). The results are shown in Table 1 .
[Comparative Example 7]
Except for the addition amount of polyethylene glycol (d-1), the same operations as in Example 10 were performed for evaluation. The results are shown in Table 1 .
[Comparative Example 8]
Evaluation was performed by performing the same operations as in Example 1 except that the mold temperature during molding was 50 ° C. The results are shown in Table 1 .

The molded article of polyacetal resin of the present invention has less formaldehyde emission and warpage, and also has excellent surface appearance, so it reduces the amount of formaldehyde emission, and is used for music, video or information equipment that requires high precision and good appearance. It can be suitably used in fields.

Claims (7)

Talc (C) having a melting point of 167 ° C. to 173 ° C. with respect to 100 parts by mass of the polyacetal copolymer (A), 0.01 to 0.5 parts by mass of the hydrazide compound (B), and an average particle size of 10 μm to 20 μm Obtained by molding a polyacetal resin composition containing 0.001 to 0.03 parts by mass and alkylene glycol (D) 0 to 5 parts by mass at a mold temperature of 60 ° C. or higher and a resin temperature of 200 ° C. or higher and 220 ° C. or lower. Parts used for music, video or information equipment, including polyacetal resin moldings.   The component according to claim 1, wherein the hydrazide compound (B) is represented by the following general formula.
  H ₂ NHNOC-R ^Five -CONHNH ₂
(Where R ^Five Is a hydrocarbon having 2 to 20 carbon atoms)   The component according to claim 1 or 2, wherein the hydrazide compound (B) is selected from the group consisting of sebacic acid dihydrazide, adipic acid dihydrazide, dodecanedioic acid dihydrazide, isophthalic acid dihydrazide, and 2,6-naphthalenedicarbodihydrazide.   The component according to any one of claims 1 to 3, wherein the talc (C) is not surface-treated.   The component according to any one of claims 1 to 4, wherein the alkylene glycol compound (D) is polyethylene glycol.   The polyacetal resin composition is an antioxidant, a polymer or compound containing formaldehyde-reactive nitrogen, a formic acid scavenger, a weathering (light) stabilizer, a release agent, and 100 parts by mass of the polyacetal copolymer (A). The component according to any one of claims 1 to 5, comprising 0.01 to 10 parts by mass of at least one (E) selected from the group consisting of lubricants.   The area of the thin portion of 1 mm or less of the polyacetal resin molding is 2 cm. ² The component according to any one of claims 1 to 6, which is the above.