JP2002363317A - Coated polyamide molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a coated polyamide molding having a good moldability and an excellent thermal fusibility at a low cost by combining entirely different kinds of hard/soft materials, i.e., by combining a polyamide resin excellent in strengths and stiffness with a soft thermoplastic resin elastomer. SOLUTION: This coated polyamide molding is prepared by coating a polyamide molding comprising (A) a polyamide resin consisting of a crystalline polyamide resin and an amorphous polyamide resin, (B) a thermoplastic resin composition having functional groups reactive with a polyamide resin, and optionally (C) an inorganic filler with (D) a thermoplastic resin elastomer compatible with (B) the thermoplastic resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a polyamide resin having excellent strength, rigidity and impact resistance, which is coated with a flexible thermoplastic resin elastic body on the surface of the molded article and heat-sealed, thereby obtaining strength and rigidity. The present invention relates to a polyamide-based molded article having both grip properties, packing, sealing properties, and vibration absorption properties.

[0002]

2. Description of the Related Art Conventionally, a composite molded article made of a hard material and a soft material has been composite-molded with a combination of a hard olefin material and a homogenous material such as an olefin-based flexible material, and heat-fused.
Various product developments have been performed. (For example, Japan Rubber Association Journal, VOL. 69, No. 9, P. 631 (1996), Plastics VOL. 48, No. 3, P. 30 (199)
7)) In addition, compatibility between different materials is extremely important for heat-sealing different materials, and in the case of a combination of homogeneous materials, heat-sealing can be performed relatively easily. However,
Such a combination of homogenous materials has the disadvantage that only very limited materials can be used and the field of application is also limited.

On the other hand, a general-purpose elastomer such as a styrene-based thermoplastic elastomer or an olefin-based thermoplastic elastomer is blended with a polyamide-based thermoplastic elastomer made of polyether block amide or an engineering elastomer having a polar group such as a polyester thermoplastic elastomer to obtain a flexible material. It has been reported that a material is made and thermally fused with a hard material such as ABS, polycarbonate, nylon, and PBT (for example, Japanese Patent Publication No. 6-9878, Japanese Patent Publication No. 7-11662). However,
These methods use special flexible materials that are blended with general-purpose thermoplastic elastomers and extremely expensive polyamide-based thermoplastic elastomers or polyester-based thermoplastic elastomers. In this case, phase separation of the flexible material occurs, and it becomes a defective portion of the molded product, which is not preferable.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art, and is a completely different type of hardening material comprising a polyamide resin having excellent strength and rigidity and a flexible thermoplastic elastic material. An object of the present invention is to produce a polyamide-coated molded article having excellent heat-fusibility and good moldability in combination with a flexible material at low cost.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and have finally completed the present invention. That is, the present invention provides (A) a polyamide resin containing a crystalline polyamide resin and an amorphous polyamide resin, (B) a thermoplastic resin composition having a functional group that reacts with the polyamide resin, and (C) an inorganic resin if necessary. A polyamide molded article obtained from a polyamide resin composition containing a filler is coated with (D) a thermoplastic resin elastic body compatible with the thermoplastic resin composition as the component (B). A polyamide-coated molded article characterized by the above-mentioned.
(A) 90 to 50% by weight of a polyamide resin and (B) 100% by weight of a composition comprising 10 to 50% by weight of a thermoplastic resin composition having a functional group reactive with the polyamide resin.
(D) heat that is compatible with (D) the thermoplastic resin composition as component (B) in a polyamide-based molded article obtained from a polyamide-based resin composition containing 0 to 200 parts by weight of an inorganic filler; The above-mentioned polyamide-coated molded article covered with a plastic resin elastic body. (B) The polyamide-coated molded article as described above, wherein the thermoplastic resin composition is a single resin selected from a general-purpose resin, an engineering plastic, a flexible resin, and a thermoplastic elastomer, or a blend of two or more resins. . (D) The polyamide-coated molded article described above, wherein the elastic body of the thermoplastic resin has a JIS-A hardness of 90 to 30 degrees.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The (A) polyamide resin in the present invention has an acid amide bond (—CONH—) in the molecule, and specifically includes ε-caprolactam, 6-aminocaproic acid, ω
Polymer or copolymer obtained from enantholactam, 7-aminoheptanoic acid, 11-aminoundecanoic acid, α-aminononanoic acid, α-pyrrolidone, α-piperidone, etc., hexamethylenediamine, nonamethylenediamine, undecamethylene A crystalline polyamide polymer and an amorphous polyamide polymer obtained by polycondensing a diamine such as diamine, dodecamethylenediamine, and meta-xylylenediamine with a dicarboxylic acid such as terephthalic acid, isophthalic acid, adipic acid, and sebacic acid. Alternatively, it is a polyamide resin containing a crystalline polyamide resin composed of a crystalline polyamide copolymer or an amorphous polyamide copolymer and an amorphous polyamide resin.

[0007] The crystalline polyamide resin has a melting point and a glass transition point.
Differential scanning calorimeter (DS) after heating the resin at 160 ° C for 1 hour
C) The temperature is raised at 20 ° C./min and the heat of crystal fusion is 4 J / g or more. Specifically, nylon 6 (calorific value =
52 J / g), nylon 66 (calorie = 65 J / g), nylon 6 / nylon 66 copolymer (calorie = 40 J / g)
g), nylon 46 (calorific value = 90 J / g), nylon 1
2 (calorific value = 38 J / g), nylon 6T / nylon 66
Copolymer (calorie = 48 J / g), nylon MXD-6
(Calorific value = 40 J / g), and nylon 6 and nylon 66 are preferred in the invention.

[0008] The amorphous polyamide resin has only a glass transition point.
20 ° C / differential scanning calorimeter (DSC) after heating for 1 hour
And a crystal melting heat of 3 J / g or less, and a number average molecular weight of 7,000 to 30,
000 are preferably used. Specific examples of the amorphous polyamide resin include nylon 6T / nylon 6
6 copolymer (calorific value = 2 J / g), nylon 6T / nylon 6I copolymer (caloric value = 0.5 J / g), nylon TM
DT / nylon 6 copolymer (caloric value = 0.7 J / g) and the like. In the present invention, nylon 6T / nylon 66 copolymer and the like are preferable, and blends with various nylon copolymers are also preferable. preferable.

The preferred blending ratio of the crystalline polyamide resin and the amorphous polyamide resin is 90 to 50% by weight of the crystalline polyamide and 10 to 50% by weight of the amorphous polyamide with respect to the polyamide resin composition. 85 to 65% by weight of crystalline polyamide, amorphous polyamide 1
The content is 5 to 35% by weight, but is not limited thereto.

The thermoplastic resin composition (B) used in the present invention is a single resin or a blend of two or more resins selected from general-purpose resins, engineering plastics, flexible resins, thermoplastic elastomers and the like. Is obtained by kneading. Specifically, various polyethylenes, isotactic polypropylene, syndiotactic polypropylene, polybutene-1, 4-
Olefin general-purpose resin such as methylpentene-1. Polystyrene, syndiotactic polystyrene, AS resin, AB
Styrene-based general-purpose resins such as S resin and polystyrene-modified polyphenylene ether resin. Engineering plastics such as PMMA resin, PET resin, PBT resin, polycarbonate, polyarylate, polyacetal resin, etc. ethylene
/ Propylene copolymer, ethylene / butene-1 copolymer, ethylene / octene-1 copolymer, ethylene / hexene-1 copolymer, ethylene / 4-methylpentene-1 copolymer, ethylene / cyclic olefin copolymer, etc. Ethylene copolymer. Propylene copolymers such as propylene / ethylene copolymer and propylene / butene-1 copolymer. Butene-1 copolymers such as butene-1 / ethylene copolymer and butene-1 / propylene copolymer. Ethylene / acrylic acid copolymer, ethylene / ethyl acrylate copolymer,
Acrylic copolymers such as ethylene / methacrylic acid copolymer and ethylene / methyl methacrylate copolymer. In addition, flexible resins such as ionomer resins and ethylene / vinyl acetate copolymers. Various olefinic thermoplastic elastomers such as dynamically crosslinked olefinic thermoplastic elastomer (TPO), blended type TPO, and polymerized type TPO.
Various styrenic thermoplastic elastomers (specifically, SB
S, SIS, SEBS, SEPS, vinyl SEPS, hydrogenated SBR, etc.), thermoplastic elastomers such as urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers. Specific examples of various general-purpose resins, engineering plastics, flexible resins, and thermoplastic elastomers have been given, but the thermoplastic resin composition of the present invention is not limited to these.

The amount of the thermoplastic resin composition (B) is 10 to 50% by weight, preferably 10 to 40% by weight, and more preferably 15 to 35% by weight. If the amount is less than 10% by weight, heat-fusibility with the thermoplastic resin elastic body is poor, and if the amount exceeds 50% by weight, phase inversion with the polyamide resin may occur, which is not preferable.

The thermoplastic resin composition (B) is used to improve the compatibility with the polyamide resin (A).
It has a functional group that reacts with the polyamide resin, and examples of the functional group that reacts with the polyamide resin include a carboxylic acid group, an acid anhydride group, an epoxy group, an oxazoline group, an amino group, and an isocyanate group. Of these, acid anhydride groups have the highest reactivity and are particularly preferred.

As a method for producing a thermoplastic resin composition containing a functional group which reacts with the polyamide resin as the component (B), a compound having the above-mentioned functional group is blended at the time of producing the thermoplastic resin composition. A method of reacting with the constituents of the thermoplastic resin composition, a method of mixing pellets of the thermoplastic resin composition with the compound having the above functional group, kneading with an extruder or the like, and reacting with the constituents of the thermoplastic resin composition. In the present invention, any of the methods can be adopted.

Specific examples of the inorganic filler (C) used in the present invention include glass fibers, carbon fibers, ceramic fibers, various whiskers, and fibrous inorganic reinforcing materials such as acicular wollastonite, silica, alumina, and the like. Examples include powdery inorganic fillers such as talc, kaolin, quartz, powdered glass, mica, and graphite. These inorganic fillers can be used alone or in combination of two or more. These inorganic fillers may be treated with a silane coupling agent as a surface treating agent, and aminosilane is particularly preferred. The compounding amount of the (C) inorganic filler is (A)
The amount is from 0 to 200 parts by weight, preferably from 0 to 200 parts by weight, based on 100 parts by weight of the polyamide resin and the thermoplastic resin composition (B).
160 parts by weight, especially 0 to 150 parts by weight, is desirable. If the amount of the inorganic filler is more than 200 parts by weight, it is not preferable because glossy unevenness of the appearance of the molded article occurs and the appearance becomes poor.

Next, the thermoplastic resin elastic body (D) used in the present invention is compatible with the thermoplastic resin composition as the component (B) and mainly comprises a hard segment and a soft segment. And a blend of a block copolymer, a graft copolymer, a partially crosslinked polymer, and a homopolymer having excellent compatibility. In the present invention, it is important to select a combination in which the thermoplastic resin composition (B) and the elastic body of the thermoplastic resin (D) are compatible with each other, and the compatible combination is defined as a solvability parameter (SP value). Is considered as one standard, but it is necessary to knead both resins and to confirm compatibility.

Specific examples of the component (D) include dynamically crosslinked olefinic thermoplastic elastomers (TPO), blended TPO, and polymerized TPO. SBS, SIS, S
Styrenic thermoplastic elastomers such as EBS, SEPS, vinyl SEPS and hydrogenated SBR. Urethane-based thermoplastic elastomer. Polyester-based thermoplastic elastomer. Polyamide thermoplastic elastomer. And other thermoplastic elastomers.
Ethylene having a high copolymerization component in ethylene-based copolymer
Propylene copolymer, ethylene / butene-1 copolymer,
Examples thereof include an ethylene / octene-1 copolymer and a blend of a homopolymer compatible with the copolymer.

The component (D) in the present invention is used for coating and heat-sealing the surface of a highly rigid polyamide molded article to impart grip properties, packing and sealing properties, and vibration absorption. Lower hardness is preferred. The preferred surface hardness is 90 to 30 degrees, more preferably 80 to 35 degrees in JIS-A hardness. If the hardness exceeds 90 degrees, the grip and sealing properties are poor, and if the hardness is less than 30 degrees, the heat resistance and moldability of the thermoplastic resin elastic body (D) are inferior, and it is difficult to coat and form with the polyamide resin. Is not preferred.

The method for producing a polyamide-coated molded article in the present invention is not particularly limited, and a known method of coating or laminating (D) a thermoplastic resin elastic body on a polyamide-based molded article and heat-sealing the same. All manufacturing methods are included. As an example of a specific production method, after injection molding of a polyamide resin, the mold is immediately rotated to further injection-mold (D) a thermoplastic resin elastic body on the entire or partial surface of the polyamide molding. "Two-color injection molding method" of coating and fusing, and "outsert" in which a molded product preformed of a polyamide resin is mounted in the cavity of a mold and additional molding is performed on the entire surface or a part of the molded product Or a double-layer extrusion method, in which a polyamide resin and (D) a thermoplastic resin elastic body are simultaneously extruded and thermally fused by a two-layer extrusion molding machine. This also employs a "thermal ramie method" in which a sheet or molded article of (D) thermoplastic resin elastic material which has been molded in advance is laminated and thermally fused by an ultrasonic welding machine or a vibration welding machine or the like. However, the present invention Not intended to be constant.

The polyamide-coated molded article of the present invention can be used as a high-strength, high-rigidity polyamide-based molded article without using a special adhesive, and is flexible, has excellent gripping properties, sealing properties, and vibration absorption properties, and is made of polyamide resin. By laminating and heat-sealing resins having completely different properties, a composite molded product having many functions can be manufactured at low cost.

[0020]

Next, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these examples. The compatibility between the component (B) and the component (D) and the fusion strength (adhesion strength) of the coated molded article were measured and evaluated by the following peel strength. Compatibility between component (B) and component (D): Both resins were mixed and kneaded at a ratio of 50/50 to form pellets. Injection molding it to make a 1mm flat plate,
The peeling phenomenon when the molded product was bent was visually evaluated. 〇: No peeling, ×: Peeling. Peel strength: The evaluation sample in the two-color molding method and the outsert molding method described below was measured by measuring the peel strength by pulling a polyamide-based resin and a styrene-based flexible resin in a 90 ° direction. As an evaluation sample in the thermal ramie molding method, the polyamide resin and the elastic body (D) of the thermoplastic resin were pulled in the direction of 180 °, and the peel strength was measured. In each case, the pulling speed is 1
It was 00 mm / min. ：: Peel strength of 1.0 kg / 15 mm or more ×: Peel strength ≒ 0 kg / 15 mm or less

Reference Example 1 (Production of polyamide resin Ny-1) 50% by weight of a crystalline polyamide resin (Nylon T-803, number average molecular weight 12,000, manufactured by Toyobo Co., Ltd.) and an amorphous polyamide resin (Manufactured by EMS Co., Ltd.
Grivory G21: 6T / 6I copolymerized nylon) 15% by weight, acid-modified polypropylene (Grand Polymer Co., Ltd.)
MMP-006) 35% and mixed with a twin screw extruder.
The mixture was kneaded at a cylinder temperature of 50 ° C. and pelletized.

Reference Example 2 (Production of Ny-2 Polyamide Resin) 55% by weight of Ny6 (Nylon T-803 manufactured by Toyobo Co., Ltd.) as a crystalline polyamide resin and the same as Reference Example 1 as an amorphous polyamide resin 15% by weight of G21 manufactured by EMS, acid-modified polypropylene (manufactured by Grand Polymer Co., Ltd.)
MMP-006) was mixed with 30% by weight, and kneaded with a twin-screw extruder at a cylinder temperature of 250 ° C. to obtain pellets.

Reference Example 3 (Production of Ny-3 polyamide resin) Ny6 (manufactured by Toyobo Co., Ltd.) as a crystalline polyamide resin
35% by weight of nylon T-803), 15% by weight of G21 manufactured by EMS as in Reference Example 1 as an amorphous polyamide resin,
20% by weight of acid-modified polypropylene and 30% by weight of glass fiber (RES-03-TP64 manufactured by Nippon Glass Fibers Co., Ltd.) were mixed and kneaded with a twin-screw extruder at a cylinder temperature of 260 ° C. to obtain pellets.

Reference Example 4 (Production of polyamide resin Ny-4) Maleic anhydride was added to ethylene / octene-1 copolymer (Engage 8402 manufactured by Dow Chemical Co., Ltd.).
5 parts by weight and 0.2 parts by weight of dicumyl peroxide were mixed and kneaded with a twin-screw extruder at a cylinder temperature of 220 ° C. to produce an acid-modified ethylene / octene-1 copolymer. 30% by weight of this acid-modified product, 55% by weight of Ny6 as a crystalline polyamide resin, and 15% by weight of G21 as in Example 1 of EMS as an amorphous polyamide resin were mixed with a twin screw extruder. The mixture was kneaded at a cylinder temperature of 250 ° C. to form pellets.

Reference Example 5 (Production of polyamide resin Ny-5) 0.5 parts by weight of maleic anhydride and 0.2 parts of dicumyl peroxide were added to polybutylene terephthalate (PBT, Tuffpet N-1000 manufactured by Mitsubishi Rayon Co., Ltd.). Parts by weight, and kneaded with a twin-screw extruder at a cylinder temperature of 250 ° C.,
Acid-modified PBT was produced. 30% by weight of this acid-modified PBT, 50% by weight of nylon 6 as a crystalline polyamide resin, and G2 as in Example 1 of EMS as an amorphous polyamide resin.
1 was mixed with 20% by weight, and kneaded with a twin-screw extruder at a cylinder temperature of 250 ° C. to obtain pellets.

Reference Example 6 (Production of Ny-6 Polyamide Resin) Ny6 was 60% by weight as a crystalline polyamide resin, and G2 was the same as that of Reference Example 1 of EMS as an amorphous polyamide resin.
1 to 10% by weight, acid-modified styrene / ethylene / butylene /
30% by weight of a styrene copolymer (SEBS, manufactured by Asahi Kasei Corp., Tuftec M-1943) is mixed and mixed at 250 ° C. with a twin screw extruder.
And kneaded at a cylinder temperature to form pellets.

Reference Example 7 (Production of polyamide resin Ny-7) Ny6 (Toyobo nylon, T-80, manufactured by Toyobo Co., Ltd.)
A pellet was formed in the same manner as in Reference Example 1 using only 3).

Reference Example 7 The thermoplastic resin elastic bodies EP-1 to EP-5 are as follows. EP-1: hydrogenated styrene / butadiene copolymer (HSB
R JSR Corporation Dynalon 1320P, hardness 39A) EP-2: Olefinic thermoplastic elastomer (TPO,
EP-3: Ethylene / octene-1 copolymer (Engage 8180 hardness 66A, manufactured by Dow Chemical Co., Ltd.) EP-4: Polyester thermoplastic elastomer (TPE)
E, Toyobo Co., Ltd. Perprene P-30B Hardness 85A
EP-5: Styrene / ethylene / propylene / styrene copolymer (SEPS, Septon 2062 manufactured by Kuraray Co., Ltd.)
Hardness 39A)

Examples 1, 2, 3, 5, 6 Comparative Example 1,
3, 4 (Two-color molding method) A two-color molding machine of core rotation type (KS-2C300, manufactured by Takahashi Seiki Kogyo Co., Ltd.) using a mold having the product shape shown in FIG.
Mold) at a mold temperature of 40 ° C and primary injection molding at 260 ° C cylinder temperature to mold the respective polyamide resin, and a secondary injection molding machine at 230 ° C cylinder temperature.
, Various thermoplastic resin elastic bodies shown in Table 1 were molded to produce molded articles for evaluation.

Examples 4, 7, 8 and Comparative Example 2 (Outsert molding method) Primary injection molding was performed with the above two-color molding machine, and a primary injection molded article was molded with a polyamide resin, and a mold was formed. Take out from
Heat retention and moisture absorption prevention were performed in a dryer at about 100 ° C. Next, the polyamide-based molded product that had been molded in advance was mounted in the primary cavity of the mold of the secondary-side injection molding machine, and a laminate of a thermoplastic resin elastic material was formed to produce a molded product for evaluation. The molding conditions are the same as in the two-color molding method. Example 1
7, Table 1 shows the evaluation results of Comparative Examples 1 to 4.

[0031]

[Table 1]

As is clear from Examples 1 to 7, the heat-fusibility between the laminated layers of the polyamide-coated molded article of the present invention is excellent.
It can be seen that a polyamide-coated molded article that is firmly bonded and durable can be obtained. On the other hand, in Comparative Examples 1 and 2, there was no thermal fusion between the laminate of the thermoplastic resin elastic body and the polyamide resin composition in which the thermoplastic resin composition having a polar group reactive with the polyamide resin was not blended. Comparative Examples 3 to
As shown in 4, when the compatibility between the thermoplastic resin composition and the elastic body of the thermoplastic resin is poor, the heat sealability between the laminates is poor, and a durable polyamide-based molded article cannot be produced. .

[0033]

The polyamide-based molded article of the present invention is excellent in strength, rigidity and impact resistance, and can be used at low cost to obtain a laminated molded article having surface properties of grip and packing sealability. It can be used in a wide range of application fields such as sports and recreational goods, automobile parts, office supplies, etc., and greatly contributes to the industrial world.

[Brief description of the drawings]

FIG. 1 is a perspective view of an evaluation sample of a polyamide-based molded article of the present invention.

[Explanation of symbols]

 1: Elastic thermoplastic resin (secondary injection molding) 2: Polyamide resin (primary injection molding)

Continued on the front page F-term (reference) 4F006 AA12 AA14 AA15 AA22 AA32 AA35 AA36 AA37 AA38 AB13 AB14 AB16 AB35 AB37 AB38 AB52 CA04 CA07 4F100 AA00A AA00H AK01A AK03B AK04B AK04J AK07A12 A07 BAK AK07BAB BA15 CA23A GB32.

Claims (4)

[Claims] 1. A polyamide resin containing (A) a crystalline polyamide resin and an amorphous polyamide resin, (B) a thermoplastic resin composition having a functional group which reacts with the polyamide resin, and optionally (C) (D) A thermoplastic resin elastic body compatible with the thermoplastic resin composition as the component (B) is coated on a polyamide molded article obtained from the polyamide resin composition containing an inorganic filler. A polyamide-coated molded article, characterized in that: (A) 90 to 50% by weight of a polyamide resin,
(B) A polyamide resin containing (C) 0 to 200 parts by weight of an inorganic filler with respect to 100 parts by weight of a composition comprising 10 to 50% by weight of a thermoplastic resin composition having a functional group reactive with a polyamide resin. The polyamide-based molded article according to claim 1, wherein the polyamide-based molded article obtained from the resin composition is coated with (D) a thermoplastic resin elastic body compatible with the thermoplastic resin composition as the component (B). body. (3) a thermoplastic resin composition comprising: a general-purpose resin;
The polyamide-based molded article according to claim 1, wherein the molded article is a single resin selected from engineering plastics, flexible resins, and thermoplastic elastomers or a blend of two or more resins. 4. The polyamide-coated molded article according to claim 1, wherein (D) the thermoplastic resin elastic body has a JIS-A hardness of 90 to 30 degrees.