JP2003327634A - Polyamide resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a polyamide resin composition having excellent mechanical characteristics and thermal characteristic equivalent to those obtained when irradiating an active energy ray to the composition without conducting its intermolecular crosslinking by irradiation with the active energy ray. <P>SOLUTION: The polyamide resin composition is characterized in that it contains 0.01-10 wt.% crosslinking agent based on the polymide resin, wherein nylon 6, nylon 66, nylon 12, or the like, is used as the polymide resin, and triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl benzene phosphonate, or the like, is used as the crosslinking agent. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyamide resin composition having excellent mechanical properties and thermal properties equivalent to those obtained by irradiation with active energy rays without irradiation of active energy rays for intermolecular crosslinking. Regarding things.

[0002]

2. Description of the Related Art Polyamide-based resins are widely used as synthetic fibers, films, various molding materials, etc. because of their excellent physical and chemical properties. Especially in recent years, it has been widely used in various electronic / electrical parts, automobile parts, mechanical parts, etc. as an engineering plastic by taking advantage of the properties such as abrasion resistance, heat resistance, mechanical properties, and electrical properties of polyamide resins. Is becoming.

However, as the applications are expanded and diversified, higher performance and special functions are required for resins. For example, when performing blow molding or extrusion molding,
Since the polyamide resin has a low melt viscosity and is difficult to mold, it is required to improve the melt viscosity of the polyamide resin. Further, improvement in heat resistance is also required so that it can withstand even more severe operating environments.

It is generally well known that melt viscosity and heat resistance can be improved by forming a crosslinked structure or a branched structure in a thermoplastic resin. For example, a technique of irradiating a crystalline polymer with an active energy ray to perform intermolecular crosslinking is known, and polyethylene is irradiated with an active energy ray to be intermolecularly crosslinked to be put to practical use for coating an electric wire or a cable. . For polyethylene such as polyethylene, which is easily cross-linked by active energy rays and has less polymer chain scission or odor generation, direct irradiation with active energy rays does not cause any problems, but in the case of polyamide, simultaneous irradiation with There is a problem that the polymer chain is easily broken and the resin is damaged. In addition, there is a problem in that the active energy ray irradiation has low productivity and requires equipment so that the cost becomes high.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and allows direct irradiation of active energy rays,
An object of the present invention is to provide a polyamide resin composition having improved mechanical properties and thermal properties.

[0006]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that a polyamide resin composition prepared by mixing a polyamide resin with a predetermined amount of a specific crosslinking agent is irradiated with active energy rays. The present invention has been completed by finding that they have excellent mechanical properties and thermal properties without doing so.

That is, the present invention relates to a polyamide resin,
The present invention relates to a polyamide resin composition containing 0.01 to 10% by weight of a crosslinking agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the polyamide resin in the present invention, hexamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4- or 2,
4,4-trimethylhexamethylenediamine, 1,3-
Or 1,4-bis (aminomethyl) cyclohexane,
Aliphatic, alicyclic and aromatic diamines such as bis (p-aminocyclohexylmethane), m- or p-xylylenediamine and adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid Polyamide obtained by polycondensation with dicarboxylic acid such as aliphatic, alicyclic, aromatic, etc., polyamide obtained by condensation of aminocarboxylic acid such as ε-aminocaproic acid, 11-aminoundecanoic acid, ε-caprolactam, Examples thereof include polyamides obtained from lactams such as ω-laurolactam, copolyamides composed of these components, and mixtures of these polyamides. Specifically, for example, nylon 6, nylon 66, nylon 4
6, nylon 610, nylon 9, nylon 11, nylon 12, nylon 6/66, nylon 66/610,
Commercial products such as nylon 6/11 may be mentioned. Of these, nylon 6, nylon 66, and nylon 12 are particularly preferable from the viewpoint of improving moldability and heat resistance.

Examples of the cross-linking agent in the present invention include polyfunctional acrylic monomers, polyfunctional allyl monomers, and mixed monomers thereof. More specific examples include, as the polyfunctional acrylic monomer, ethylene oxide-modified bisphenol A di (meth) acrylate, 1,4-butanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipentaerythritol hexa. Acrylate, dipentaerythritol monohydroxypentaacrylate, caprolactone modified dipentaerythritol hexaacrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, polyethylene glycol di (meth) acrylate,
Trimethylolpropane triacrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO
Modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate,
Tris (methacryloxyethyl) isocyanurate and mixtures thereof are common. In particular, tris (acryloxyethyl) isocyanurate (triacrylic acid ester of tris (2-hydroxyethyl) isocyanuric acid) has low skin irritation and can be preferably used.

Further, as the polyfunctional allyl monomer,
Examples include triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl benzene phosphonate and mixtures thereof.

The crosslinking agent may include an initiator, a catalyst, and
Stabilizers and the like can be added. These initiators, catalysts, stabilizers, etc. may be added to the crosslinking agent or may be added to the polyamide resin.

The polyamide resin composition of the present invention contains a crosslinking agent in an amount of 0.01 to 10% by weight, preferably 0.1 to 5% by weight, based on the polyamide resin. When the content of the cross-linking agent is less than 0.01% by weight, mechanical properties and thermal properties of the polyamide resin are not improved. On the contrary, if it exceeds 10% by weight, mechanical properties such as elongation and impact strength are adversely affected, which is not preferable.

In the polyamide resin composition of the present invention, if necessary, antioxidants such as hindered phenols, phosphoric acid esters and phosphorous acid esters, heat resistance stabilizers, and weather resistance imparting agents such as triazine compounds, Plasticizer, antistatic agent, flame retardant, glass fiber, glass beads, metal powder, talc, mica, other inorganic and organic fillers, pigments, colorants such as dyes, lubricants, water repellents, antiblocking agents , A flexibility improver and the like can be added.

Other thermoplastic resins such as polystyrene resin, HIPS resin (high impact polystyrene resin), AS resin (acrylonitrile-styrene resin),
Polystyrene resin such as ABS resin (acrylonitrile-butadiene-styrene resin), polyvinyl chloride resin,
Polyvinylidene chloride resin, polycarbonate resin, polyolefin resin, polyester resin, polyphenylene ether resin, natural rubber, synthetic rubber, etc. may be added.

The polyamide resin composition of the present invention can be produced by melt-kneading the polyamide resin and the crosslinking agent so that the content of the crosslinking agent with respect to the polyamide resin is a predetermined ratio. The heating temperature is 220-320 ℃,
The temperature is preferably 240 to 300 ° C., particularly preferably 10 ° C. or higher higher than the melting point of the polyamide resin and 290 ° C.
It is the following. If it is lower than 220 ° C, the melting of the polyamide resin is insufficient, and if it exceeds 320 ° C, the resin is decomposed or an abnormal reaction is caused, which is not preferable. As an apparatus used for melt kneading, for example, a Banbury mixer, a pressure kneader,
The kneading extruder, the twin-screw extruder, the roll, or the like can be used.

The polyamide resin composition of the present invention is useful as a molding material and can be formed into various molded articles such as sheets, films, fibers, trays, containers and bags by injection molding, extrusion molding, blow molding and the like. it can. Examples of the molding machine used include an extrusion molding machine, a compression molding machine, a vacuum molding machine, a blow molding machine, a T-die type molding machine, an injection molding machine, and an inflation molding machine.

As typical examples of applications of molded articles obtained from the polyamide resin composition of the present invention, sheets, films, fibers in which polyethylene terephthalate (PET), nylon, polypropylene (PP) and the like have hitherto been used.
Market fields such as containers and bags, and automotive parts such as coated cables, tubes, belts and gears that have been covered by coating and alloying technologies, intake manifolds, cylinder head covers, door panels, automotive outer panels such as fenders, etc. Market areas such as automotive parts, home appliance parts, and industrial machine parts.

[0018]

EXAMPLES The present invention will now be described in detail with reference to examples, but the present invention is not limited thereto. The materials used in the examples, the physical property measurement conditions, and the kneading method are as follows. [Polyamide resin] PA66: Ube Industries, Ltd. 2020B (ηr 2.69) PA6: Ube Industries, Ltd. 1015B (ηr 2.63) PA12: Ube Industries, Ltd. 3020B (ηr 1.90) [Crosslinking agent] TAIC (Tori) Allyl isocyanurate): Nippon Kasei
WH-60 manufactured by Co., Ltd. (WH-60 is white carbon with 60% impregnated in the example: pure TAIC amount in the example) [Creep characteristics] Tensile creep strain after 250 hours was measured under the following conditions. . The smaller the number, the smaller the amount of deformation and the better the mechanical properties when stressed for a long period of time. Test piece: ASTM No. I test atmosphere temperature: 120 ° C. Load stress: 10 MPa (PA12 is 3 MPa) [Kneading method] (1) Kneading machine: Toshiba Machine Co., Ltd. TEM-35B (2) Kneading condition Resin melting temperature: 280 ℃ Vent vacuum degree: 260torr Discharge rate: 20kg / hr Screw rotation speed: 150rpm

Examples 1 to 5 The polyamide resin and the cross-linking agent shown in Table 1 were melt-kneaded in a kneader to give the polyamide resin and the cross-linking agent.
A resin composition contained in the ratio described in 1. was obtained. The obtained resin composition was injection-molded and the creep characteristics were measured. The results are shown in Table 1.

Comparative Example 1 The creep characteristics were measured for the polyamide resins shown in Table 1 which were injection-molded as they were without adding a crosslinking agent. The results are shown in Table 1.

Comparative Example 2 The creep properties of the polyamide resins shown in Table 1 were injection-molded as they were without adding a crosslinking agent and subjected to electron beam irradiation under the irradiation dose of 30 KGy. . The results are shown in Table 1.

Comparative Examples 3 to 4 The polyamide resin and the cross-linking agent shown in Table 1 were melt-kneaded in a kneader to give the polyamide resin and the cross-linking agent.
A resin composition contained in the ratio described in 1. was obtained. The obtained resin composition was injection-molded and subjected to electron beam irradiation under the conditions shown in Table 1 to measure the creep characteristics. The results are shown in Table 1.

Comparative Examples 5 to 6 Creep characteristics of the polyamide resins shown in Table 1 were measured as they were without injection of a crosslinking agent and injection molding. The results are shown in Table 1.

[0024]

[Table 1]

[0025]

EFFECTS OF THE INVENTION The polyamide resin composition of the present invention has excellent mechanical properties and thermal properties equivalent to those of irradiation with active energy rays without irradiation of active energy rays for intermolecular crosslinking. . Therefore, by injection molding, extrusion molding, blow molding, etc., sheets, films, fibers, containers, bags, coated cables, tubes, belts, pulleys,
It can be applied to various molded products such as automobile parts such as connectors and gears, intake manifolds, cylinder head covers, door panels, automobile outer plates such as fenders, home electric appliance parts, and industrial machine parts.

Claims (4)

[Claims] 1. A crosslinking agent is added to a polyamide resin in an amount of 0.0
A polyamide resin composition comprising 1 to 10% by weight. 2. The polyamide resin composition according to claim 1, wherein the polyamide resin is nylon 6, nylon 66, nylon 12 or a mixture thereof. 3. The cross-linking agent is at least one selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallylbenzene phosphonate and mixtures thereof. The polyamide resin composition described. 4. A molded product obtained by molding the polyamide resin composition according to claim 1.