JP2000351887A - Low-warpage high-stiffness polyacetal composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyacetal composite excellent in mechanical strengths, resistances to heat and warpage, anisotropy, and dimensional stability by compounding a polyacetal resin with specified amounts of a silicate composite comprising a swellable layered silicate and an organic ammonium ion compound and a fibrous reinforcement. SOLUTION: A polyacetal resin in an amount of 100 pts.wt. is compounded with 0.01-100 pts.wt. silicate composite and 0.01-150 pts.wt. fibrous reinforcement. Examples of the layered silicate are phyllosilcates, especially a 2:1-type phyllosilicate comprising two tetrahedral layers and one octahedral layer and a 1:1-type phyllosilicate comprising one tetrahedral layer and one octahedral layer. A compound represented by R1R2R3R4N+ is listed as the organic ammonium ion compound. In the formula, R1 to R4 are each 1-40C alkyl, H, or (CH2 CH2O)nR5 (wherein R5 is 1-5C alkyl or H; and n is 1 or higher) provided at least one of R1 to R4 is (CH2CH2O)nR5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a low warpage high rigidity polyacetal composite material. More specifically, it has high mechanical strength and heat resistance, and is excellent in warpage, anisotropy, and dimensional stability, and can be used in a wide range of applications such as automotive parts, electric / electronic parts, home appliance materials, and mechanical parts. The present invention relates to a low warpage high rigidity polyacetal composite material.

[0002]

2. Description of the Related Art Polyacetal resins have excellent mechanical properties, slidability, heat resistance, electrical properties, and moldability. As representative engineering plastics, they are used in automobile parts, electric / electronic parts, and home electric appliance materials. Used in a wide range of fields, such as mechanical parts. In order to further improve the mechanical strength and heat resistance, there is a method of adding a fibrous inorganic substance such as glass fiber or whisker. However, the addition of the fibrous filler causes problems such as anisotropy and poor appearance in the molded product. In order to improve this, a method of using a planar filler such as talc or a method of using an inorganic substance obtained by pulverizing a granular or fibrous reinforcing material has been proposed.

[0003]

However, in the method using the planar filler in combination, the improvement effect cannot be exhibited unless a considerable amount of the filler is used. There is a point. In addition, when an inorganic substance obtained by pulverizing a granular or fibrous reinforcing material is used, the improvement in mechanical properties is significantly lower than that of the fibrous reinforcing material. Therefore, a low-warpage high-rigidity polyacetal composite material having high mechanical strength and heat resistance and excellent in warpage, anisotropy, and dimensional stability has been desired.

[0004]

Means for Solving the Problems The present inventors have carried out sincere studies in order to solve the problems of the prior art as described above, and as a result, have accomplished the present invention. That is, the present invention relates to (A) 100 parts by weight of a polyacetal resin, (B)
A low warpage and high rigidity polyacetal composite material comprising 0.01 to 100 parts by weight of a silicate composite comprising a swellable layered silicate and an organic ammonium ion compound and (C) 0.01 to 150 parts by weight of a fibrous reinforcing material. Is what you do.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Component (A) Polya in the present invention
Cetal resin has an oxymethylene group (-CH _TwoO-)
It is a crystalline polymer compound having a main skeleton. Sand
That is, a known polyoxymethylene homopolymer or
In addition to the xymethylene group, other structural units such as oxyethyl
Len group (-CH_TwoCH_TwoCopolymer containing small amount of O-)
-, Terpolymer and block copolymer
And molecules have not only linear but also branched and cross-linked structures
May be used, and the terminal thereof is not particularly limited.
No. In addition, the degree of polymerization, branching and cross-linking are also particularly restricted.
There is no limitation, as long as it has melt-forming processability.

As the silicate complex (B) in the present invention, a salt complex comprising a swellable layered silicate and an organic ammonium ion compound is used. The swellable layered silicate used in the present invention is rich in changes such as chemical composition and crystal structure,
There is no established classification and naming. The feature of the layered silicate here is that it is a layered crystal and belongs to phyllosilicate in mineralogy. Among them, especially, it is a 2: 1 type phyllosilicate composed of two tetrahedral layers and one octahedral layer. One example is a 1: 1 phyllosilicate composed of one tetrahedral layer and one octahedral layer. Typical minerals of 2: 1 type phyllosilicate include smectite, vermiculite, mica and chlorite, and 1: 1 type phyllosilicate includes kaolin, serpentine and the like. The smectite group includes saponite, hectorite, sauconite, montmorillonite, beidellite, nontronite, and stephensite.The vermiculite group includes trioctahedral vermiculite, dioctahedral vermiculite, and the mica group. Examples thereof include compositions such as phlogopite, biotite, lepidrite, muscobite, paragonite, chlorite, margarite, teniolite, and tetrasilicic mica. These phyllosilicates may be produced naturally or synthesized by a hydrothermal method, a melting method, a solid phase method, or the like.
Further, various compounds such as sodium, potassium, lithium, magnesium, copper (I), copper (II), and aluminum can be applied to the cations supported between the layers.

[0007] As the organic ammonium ion compound,
In the formula, R ₁ R ₂ R ₃ R ₄ N ^{+ wherein} R ₁ R ₂ R ₃ R ₄ are the same or different and have an alkyl group having 1 to 40 carbon atoms, a hydrogen atom, or (CH ₂ CH ₂ O) _n R ₅ groups (R ₅ is an alkyl group having 1 to ₅ carbon atoms or a hydrogen atom, n is 1 or more), and at least _{one of} R _{1 to} R ₄ is a (CH ₂ CH ₂ O) _n R ₅ group ] The compound shown by these is mentioned. In order to introduce the organic ammonium ion compound, an organic ammonium salt compound containing the ion is used. Examples of such a salt include Cl ⁻ , Br ⁻ , NO ₃ ⁻ , OH ⁻ , and CH ₃ C.
OO ^- salt of the anion of the like can be mentioned. The alkyl group in the organic ammonium ion compound,
Those having 1 to 40 carbon atoms are used. Specifically, methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl,
Undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, octadecyl and the like can be mentioned. Also, CH
R ₅ in ₂ CH ₂ O) _n R ₅ groups is an alkyl group or a hydrogen atom of 1 to 5 carbon atoms. Further, n is 1 or more, and particularly preferably 1 to 20. Specifically, hydroxyethyl, hydroxypolyoxyethylene, methoxyethyl,
Examples thereof include methoxypolyoxyethylene, ethoxyethyl, ethoxypolyoxyethylene, alkoxyethyl, and alkoxypolyoxyethylene.

[0008] The amount of the organic ammonium ion compound added is a cation exchange capacity (hereinafter referred to as "CEC").
0.1 to 10 equivalents are preferable, but especially 0.3 to
Five equivalents are preferred. If the amount of the organic ammonium ion compound is less than 0.1 equivalent to CEC, the dispersibility of the layered silicate in the composite material is reduced, and the effect on low warpage is reduced. On the other hand, when the amount is more than 10 equivalents, the amount of the organic ammonium ion compound added is larger than that of the swellable phyllosilicate, so that a uniform composite cannot be formed, and the mechanical properties, moldability and the like of the composite material deteriorate. The CEC is, for example, a column permeation method (refer to “Clay Handbook” No. 56
Pages 7 to 577, published by Techniquedo) and a method for measuring the amount of adsorbed methylene blue (standard test method of Japan Bentonite Industry Association, JBAS
-107-91).

The silicate composite of the present invention is obtained by intercalating the above-mentioned organic ammonium ion compound with the swellable layered silicate to cause swelling and ion exchange reaction. Is not limited. Specifically, after the swellable layered silicate powder is sufficiently solvated with water, alcohol, or the like, the above-mentioned organic ammonium ion compound is added, and the mixture is stirred and replaced with a metal cation present between the layers of the swellable layered silicate. Let it. Thereafter, the formed precipitate is filtered and dried to obtain a silicate complex. At that time, the unsubstituted organic ammonium ion compound may be removed by washing.

[0010] The addition amount of the silicate composite is 0.01 to 100 parts by weight, preferably 0.05 to 50 parts by weight, more preferably 0.1 to 20 parts by weight based on 100 parts by weight of the polyacetal resin. It is.

Examples of the fibrous reinforcing material (C) in the present invention include whiskers such as aluminum borate, silicon nitride and potassium titanate, and fibrous inorganic fillers such as glass fibers, carbon fibers, and wollastonite. These fibrous reinforcing materials are not particularly limited in shape, size, manufacturing method and the like, and can be appropriately selected according to the purpose.
Further, the fibrous reinforcing material of the present invention may be one which has been surface-treated with a coupling agent in advance. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent. Examples of the silane coupling agent include triethoxysilane, vinyl tris (2-methoxyethoxy) silane, N- (2-aminoethyl) 3-aminopropylmethyldimethoxysilane, and N- (2-aminoethyl) 3-
Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glucidoxypropyltrimethoxysilane, 3-glucidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3 -Chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercapropropyltrimethoxysilane and the like. Examples of titanate-based coupling agents include isopropyl triisostearoyl titanate, isopropyl oris (dioctyl bilophosphate), isopropyl tri (N-aminoethyl-aminoethyl) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctylbilophosphate) oxyacetate titanate, bis (dioctylbilophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldi Methacryl isostearyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearyl diacryl titanate DOO, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, tetraisopropyl bis (dioctyl phosphite) titanate. Examples of the aluminate-based coupling agent include acetoalkoxyaluminum diisopropylate.

The amount of the fibrous reinforcing material to be added can be selected from a wide range according to the purpose of use. However, considering the mechanical properties and thermal stability of the polyacetal composite material, 0.01 to 100 parts by weight of the polyacetal resin. To 150 parts by weight, preferably 1 to 100 parts by weight, more preferably 1 to 100 parts by weight.
50 parts by weight.

In the present invention, it is preferable to further use (D) an isocyanate compound in combination. (D) Examples of the isocyanate compound include alicyclic or aliphatic isocyanates, aromatic isocyanates, and modified products thereof. Specifically, 1,6-hexamethylene diisocyanate, isophorone diisocyanate,
Alicyclic or aliphatic isocyanates such as 6-hydrogenated xylene diisocyanate, diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, 1,5-naphthalene diisocyanate, 4,4 Aromatic isocyanates such as -methylenebis (phenylisocyanate), and dimers and trimers thereof, and compounds in which isocyanate (NCO) is protected in some form. Among these, in particular, from various physical properties such as discoloration at the time of melt processing, safety in handling,
Particularly preferred are 1,6-hexamethylene diisocyanate and modified products or derivatives such as dimers and trimers.

The amount of the isocyanate compound to be added is preferably 0.01 to 20 parts by weight, particularly preferably 0.01 to 10 parts by weight, per 100 parts by weight of the polyacetal resin.

Further, the low warpage high rigidity polyacetal composite material (hereinafter, referred to as "composite material") of the present invention may contain various additives commonly used in the art, depending on the intended use. For example, various colorants, lubricants, release agents, surfactants, heterogeneous polymers, organic polymer improvers, antioxidants, light resistance agents, antistatic agents, electric insulation improvers, fungicides, inorganic, organic In addition, a fibrous, powdery or plate-like filler such as metal, and other additives may be blended within a range that does not impair the effects of the present invention and the performance of the composite material.

Further, the composite material of the present invention may be mixed with another thermoplastic resin. The type of the thermoplastic resin is not particularly limited, and specifically, a polypropylene resin, a polyolefin resin such as a polyethylene resin, a styrene resin such as polystyrene and a polystyrene-butadiene copolymer, and an acrylonitrile-styrene copolymer ,
Nitrile group-containing resin such as acrylonitrile-butadiene-styrene copolymer; aromatic polyester resin such as polyethylene terephthalate and polybutylene terephthalate; ester group-containing resin such as aliphatic polyester such as polyethylene succinate and polylactic acid; polyamide 6 , Polyamide 11, polyamide 12, polyamide 6
6, polyamide 610, polyamide 612, polyamide 46, polyamide 6-66, polyamide 6-610, polyamide 6-6T (T; terephthalic acid component), an acid amide bond (-CONH-) such as a semi-aromatic polyamide as a repeating unit And thermoplastic resins such as polyamide resins, fluorine resins, silicone resins, polyurethane resins, polycarbonate resins, polyimide resins, and various elastomers. As the compounding amount of these other thermoplastic resins,
In order to take advantage of the characteristics of the polyacetal resin, the amount is preferably less than 60 parts by weight based on 100 parts by weight of the polyacetal resin.

The method for mixing the above components for obtaining the composite material of the present invention is not particularly limited, and it can be obtained by kneading by a method generally employed in the field of synthetic resins. Also, the adjustment method is not particularly limited,
In general, it can be adjusted by a known equipment and method as a method for adjusting a synthetic resin composition or a molded product thereof. For example, after the polymerization, powder, flakes, pellets, or any other form of polyacetal resin or a commercially available polyacetal resin is sufficiently mixed with a silicate complex and an isocyanate compound in a tumbler, a super mixer, a ribbon mixer, and the like, and then mixed with a Banbury mixer and a rotor. And a method of melting and kneading at a temperature of from the melting point to 270 ° C. for at least 30 seconds with a melt kneading device such as a continuous mixer equipped with a screw or a twin screw extruder (screw rotation directions are different directions and the same direction). In addition, some of the components constituting the composition (for example, component (A) and component (B)
Or a part of the component (A) and a part of the component (D) are previously melt-kneaded (master batch), and further melt-kneaded with the remaining components to obtain a predetermined composition or molded article. No. The stabilizers and additives may be added at any arbitrary stage, and may be added and mixed immediately before obtaining a final molded product. Further, the composite material of the present invention is extrusion molding, injection molding, compression molding, vacuum molding,
It can be formed by any method such as blow molding and foam molding.

[0018]

Next, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In addition, the measuring method is as follows. (1) Flexural modulus Measured according to ASTM D791. (2) Deflection temperature under load Measured in accordance with ASTM D648. (3) Warpage Deformation A flat plate created by injection molding (size: 100 × 100
× 2 mm) was measured, and the maximum value was defined as the amount of warpage deformation. (4) Mold shrinkage and anisotropy The dimensional difference between the molded product and the mold expressed in% is defined as the mold shrinkage (%), and the flow direction (MD) of the flat plate and the direction perpendicular to the flow (TD). Was measured. The difference between MD and TD (TD-MD) was defined as anisotropy.

As the polyacetal resin, a polyacetal copolymer (trade name "Duracon" manufactured by Polyplastics Co., Ltd.) (hereinafter referred to as "POM") was used.

Production Example of Silicate Complex A synthetic mica (“ME-100”, manufactured by Corp Chemical Co., cation exchange capacity (CEC) = 80 meq / 100 g) was used as a layered silicate in distilled water (10 L) at 60 ° C. 200
g. Further, 1 equivalent of dodecylmethyldihydroxyethylammonium chloride (commercially available reagent) with respect to CEC was dissolved in distilled water, added to the above layered silicate dispersion, and stirred at 60 ° C. for 2 hours. The resulting precipitate was washed, filtered and dried, and then pulverized to an average particle size of 5 μm to obtain a silicate composite (hereinafter, referred to as “composite-1”). The organic ammonium ion compound inserted between the layers of the composite-1 was analyzed by an X-ray diffractometer (Rigaku Corporation, RINT
2000, CuKα-40 kV, 20 mA) to measure the interlayer distance, which can be confirmed from the fact that the interlayer distance increases to 18.7 ° (interlayer distance of synthetic mica; 9.6 °). In addition, the content of the organic ammonium ion compound,
It was measured using a differential thermal / thermogravimeter (manufactured by Seiko Denshi Co., Ltd.) (hereinafter referred to as “TG-DTA”), and the result was 23% by weight.

Dodecylmethyldimethoxyethylammonium chloride (commercially available reagent)
A silicate composite (hereinafter, referred to as “composite-2”) was obtained in the same manner as above except that was used. The interlayer distance of the composite-2 was 21.0 °, and the content of the organic ammonium ion compound was 25% by weight. Except for using dodecylmethyldihydroxypolyoxyethyleneammonium chloride (n = 5 to 9) (commercially available reagent) as the organic ammonium ion compound, a silicate composite (hereinafter referred to as “composite-
3 ". ) Got. The interlayer distance of the composite-3 is 25.
6%, the content of the organic ammonium ion compound was 29% by weight.

Glass fiber (CS03MAFT554, manufactured by Asahi Fiberglass Co., Ltd.) (hereinafter referred to as "GF") was used as the fibrous reinforcing material.

Hexamethylene diisocyanate (a commercially available reagent) (hereinafter referred to as "ISO-
1 ". ) And polyisocyanate (trade name “Coronate” manufactured by Nippon Polyurethane Industry Co., Ltd.) (hereinafter “ISO
-2 ". ) Was used.

Examples 1 to 5, Comparative Examples 1 to 3 100 parts by weight of a polyacetal resin and 3 parts by weight of a silicate complex (and 0.5 part by weight of an isocyanate compound) among the components shown in Table 1 Is premixed, and then supplied to a coaxial twin-screw kneader (TEM37 manufactured by Toshiba Machine Co., Ltd.)
12 parts by weight of the fibrous reinforcing material was fed from a middle part of the extruder by a weight feeder to obtain pellets. Each test piece was prepared from the obtained pellet using an injection molding machine (manufactured by Sumitomo Heavy Industries, Ltd., Cycap 75t), and various characteristics were measured. Table 2 shows the above results. In Comparative Example 1, talc (Micron White, manufactured by Hayashi Kasei Co., Ltd.) was used instead of the silicate composite.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

The composite material of the present invention has high mechanical properties,
It has thermal properties and is excellent in warpage, anisotropy and dimensional stability. In addition, since it has excellent surface appearance and workability, it is processed into various molded products, and electric and electronic parts materials, automobile parts,
This is a composite material that is useful in a wide range of fields, including home appliance materials and mechanical component materials.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Ao Ebata 3-2 Chidori-cho, Kawasaki-ku, Kawasaki-ku, Kawasaki, Kanagawa Prefecture Showa Denko KK Kawasaki Laboratory (72) Inventor Masayuki Noguchi Kawasaki-ku, Kawasaki-shi, Kanagawa 3-2 Chidoricho Showa Denko KK Kawasaki Laboratory, Research Laboratory (72) Inventor Junichi Nakamura 3-2 Chidoricho, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture Showa Denko KK Kawasaki Laboratory F-term ( Reference) 4J002 CB001 DA018 DE188 DJ006 DK008 DL008 EN137 ER009 FA048 FA068 FB086 FB098 FB168

Claims (4)

[Claims] 1. (A) 100 parts by weight of a polyacetal resin, (B) 0.01 to 100 parts by weight of a silicate composite comprising a swellable layered silicate and an organic ammonium ion compound, and (C) a fibrous reinforcing material. A low warpage high rigidity polyacetal composite material consisting of 01 to 150 parts by weight. 2. (A) 100 parts by weight of a polyacetal resin, (B) 0.01 to 100 parts by weight of a silicate composite comprising a swellable layered silicate and an organic ammonium ion compound, and (C) a fibrous reinforcing material. A low warpage high rigidity polyacetal composite material comprising from 0.01 to 150 parts by weight and from 0.01 to 20 parts by weight of an isocyanate compound (D). 3. The low warpage high rigidity polyacetal composite material according to claim 1, wherein the swellable layered silicate is a smectite-type clay and / or a swellable mica. 4. An organic ammonium ion represented by the general formula R ₁
R ₂ R ₃ R ₄ N ⁺ [wherein R ₁ R ₂ R ₃ R ₄ may be the same or different and includes an alkyl group having 1 to 40 carbon atoms, a hydrogen atom,
Or (CH ₂ CH ₂ O) _n R ₅ group (R ₅ has 1 to ₅ carbon atoms)
Wherein n is 1 or more, and at least one of R _{1 to} R ₄ is an ion represented by (CH ₂ CH ₂ O) _n R ₅ group]. The low warpage high rigidity polyacetal composite material according to claim 1 or 2.