JPH09239774A - Polyamide resin integrally molded product - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide an integrally molded product made of a polyamide resin having excellent adhesion. SOLUTION: A crystalline polyamide resin 50 to 100% by weight and a thermoplastic resin other than the crystalline polyamide resin 0 to 50
On the surface of the primary molded article obtained by molding a primary molding material which is a polyamide resin composition consisting of 10% by weight and the heat of fusion of the layer up to 500 μm is 20 mj / mg or less,
An integrally molded product made of a polyamide resin obtained by molding a secondary molding material which is a polyamide resin composition comprising 50 to 100% by weight of a crystalline polyamide resin and 0 to 50% by weight of a thermoplastic resin other than the crystalline polyamide resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide resin integrally molded product, and more specifically, to the surface of a molded product made of a resin composition containing a crystalline polyamide resin, the same or different kinds of crystalline polyamide resin are contained. The present invention relates to a polyamide resin integrally molded product obtained by molding a resin composition.

[0002]

In thermoplastics, engineering plastics have good performance and are widely used. Among them, polyamide resin has excellent mechanical properties, heat resistance, chemical resistance, wear resistance, etc.,
It is used as a material that replaces metals such as iron, zinc, and aluminum. For example, polyamide resin molded products are
It is molded by filling the mold with molten resin. However, depending on the application and shape of the product, it may not be possible to mold with a single mold. In such a case, a double shot molding method is usually used in which a molded product once molded is put in another mold and the molding material is filled therein again. For example, it has been practiced to mount a coil-molded resin molded product in a mold, then fill it with molten resin and integrate it to obtain an integrally molded product. It has been practiced to perform molding in advance, insert this into a cavity of a mold, and then fill the same or different type of resin to obtain an insert molded product, a two-color molded product, or the like. A composite product in which a resin pipe and a resin joint are integrated can also be obtained by the double shot molding method.

However, in the double shot molding method, the adhesion between the primary molded product inserted into the mold and the resin to be further filled is often insufficient, and in order to improve the adhesion, a liquid form is used. Application of an adhesive or a primer to the surface of a primary molded article is described in, for example, Japanese Patent Application No. 1-281907, but there is a problem that a step such as application is required. In addition, when a metal-encapsulated molded product or a molded product having a complicated shape is used as the primary molded product, or an integrally molded product is used for applications requiring pressure resistance and impact resistance or for precision parts. When used, it is described in Japanese Patent Application No. 1-236276 that the adhesion strength is insufficient even if an adhesive or a primer is used, and there are problems of liquid leakage and damage.

Further, there is a case where the adhesion portion between the primary molded product and the resin to be filled later is covered with an epoxy resin or a flowing silicone, but not only the number of steps is increased, Repeated changes in temperature (thermal shock), electric shock when voltage is applied to electric precision parts, and repeated pressurization of engine oil, water, etc., causes delamination of the boundary between the contact surface and the coating surface, resulting in precision machine parts and electronic parts. There were problems such as malfunctions in the equipment and liquid leakage.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyamide resin integrally molded product which is excellent in adhesion between the primary molded product and the secondary molding material molded on the surface thereof.

[0006]

The present invention has been made in order to solve the above-mentioned problems, and its gist is 50 to 100% by weight of a crystalline polyamide resin and a thermoplastic resin other than the crystalline polyamide resin. Obtained by molding a primary molding material that is a polyamide resin composition consisting of 0 to 50% by weight, and the heat of fusion of the layer from the surface to 500 μm is 20 mj / m.
A secondary molding material, which is a polyamide resin composition composed of 50 to 100% by weight of a crystalline polyamide resin and 0 to 50% by weight of a thermoplastic resin other than the crystalline polyamide resin, is formed on the surface of the primary molded article of g or less. It exists in an integrally molded product made of molded polyamide resin.

Hereinafter, the present invention will be described in detail. The primary molded article in the present invention is obtained by molding a primary molding material which is a polyamide resin composition. As the polyamide resin composition, crystalline polyamide resin 50 to
100% by weight and 0 to 50% by weight of a thermoplastic resin other than the crystalline polyamide resin, preferably 70 to 100% by weight of the crystalline polyamide resin and 0 to 30% by weight of a thermoplastic resin other than the crystalline polyamide resin. %. The primary molded article in the present invention is a molded article obtained by molding (may be referred to as primary molding) the above polyamide resin composition, and is 500 μm from the surface of the molded article.
The heat of fusion of layers up to m is 20 mj / mg or less. When the heat of fusion exceeds 20 mj / mg,
Adhesion between the primary molded product and the secondary molding material molded on the surface thereof becomes insufficient.

To reduce the heat of fusion of the layer up to 500 μm from the surface of the primary molded article to 20 mj / mg or less, for example, 1
When molding the next molding material, the molding temperature is 200 to 300 ° C.
By setting the mold temperature to 100 ° C. or lower, preferably 80 ° C. or lower, a molded article having a surface layer showing a desired heat of fusion can be obtained. As a method for measuring the heat of fusion in the primary molded product, the molded primary molded product can be cut with a precision low-speed cutting machine to cut out a surface layer of 500 μm from the surface of the primary molded product, and can be measured using a differential scanning calorimeter.

In the present invention, as the secondary molding material which is a polyamide resin composition molded on the surface of the primary molding, 50 to 100% by weight of a crystalline polyamide resin and a thermoplastic resin other than the crystalline polyamide resin are used. 0 to 50% by weight, preferably crystalline polyamide resin 70 to 1
It is composed of 00% by weight and 0 to 30% by weight of a thermoplastic resin other than the crystalline polyamide resin. The composition of the secondary molding material is
The composition of the primary molding material may be the same or different. When the surface of the primary molded product mounted in the mold is filled with the polyamide resin composition for molding, the primary molded product obtained by the primary molding can be used as it is to obtain an integrally molded product, Also, after mounting another part together with the primary molded product in the mold, the secondary molding material can be molded on the surface of the primary molded product. The ratio of the area where the primary molding product and the secondary molding material are bonded may be a part of the surface of the primary molding product or the entire surface of the primary molding product.

As the crystalline polyamide resin used in the primary molding material and the secondary molding material in the present invention, nylon 6, nylon 66, nylon 69, nylon 610, nylon 612, nylon 12, xylylenediamine and α, ω. -Polyamide resin obtained from linear aliphatic dibasic acid (hereinafter also referred to as MX nylon)
Examples thereof include MX nylon and a resin of MX nylon and nylon 66 and / or nylon 6 from the viewpoint of moldability. The mixing ratio of nylon 66 and / or nylon 6 to 100 parts by weight of MX nylon is 0 to 100 parts by weight, preferably 0 to 80 parts by weight.

As the thermoplastic resin other than the crystalline polyamide resin used in the primary molding material and the secondary molding material of the present invention, polystyrene resin, ABS resin,
AES resin, AS resin, olefin resin, methacrylic resin, polycarbonate resin, polyacetal resin, polyphenylene ether resin (PPE resin), modified PPE
Heat of resin, polyester resin, polysulfone resin, polyimide resin, polyphenylene sulfide resin, polyarylate resin, polyethersulfone resin, polyetherketone resin, polyetheretherketone resin, polyestercarbonate resin, amorphous polyamide resin, liquid crystal polymer, etc. A plastic resin or an alloy resin composition composed of two or more kinds of these resins may be mentioned, and preferably,
It is a polyphenylene ether resin (PPE resin). If necessary, inorganic or organic fibrous fillers, fillers, stabilizers, UV absorbers, dyes and pigments, etc. can be added to these materials.

The polyphenylene ether resin has the following general formula:

[0013]

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(Wherein R ¹ is a lower alkyl group having 1 to 3 carbon atoms, R ² and R ³ are hydrogen atoms or a lower alkyl group having 1 to 3 carbon atoms). It has a chain and may be a homopolymer, a copolymer or a graft polymer. Specifically, poly (2,6-dimethyl-1,4-phenylene) ether,
Poly (2,6-diethyl-1,4-phenylene) ether, poly (2,6-dipropyl-1,4-phenylene)
Examples thereof include ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene) ether, and the like. , Poly (2,6-dimethyl-1,4-phenylene) ether, 2,6 dimethylphenol / 2,3,6-trimethylphenol copolymers and graft copolymers obtained by grafting styrene onto these copolymers. preferable. Further, polyphenylene ether resin having improved compatibility (hereinafter, modified P
It is sometimes referred to as PE), and more preferable. The modified PPE is obtained by reacting PPE with an unsaturated carboxylic acid or an acid anhydride thereof. When an acid anhydride of unsaturated carboxylic acid is used for modifying PPE, the acid anhydride of unsaturated carboxylic acid and PPE are reacted in a melt-mixed state without a catalyst to obtain a modified PPE. In this case, as a method of melt mixing, a kneader, a Banbury mixer,
The extruder is not particularly limited, but it is preferable to use the extruder in consideration of operability. Examples of the acid anhydride of the unsaturated aliphatic carboxylic acid include maleic anhydride, itaconic anhydride, citraconic anhydride and the like, of which maleic anhydride is particularly preferable.

The proportion of the acid anhydride used for modifying PPE is 0.01 to 10 parts by weight, preferably 0.1 to 3 parts by weight, and particularly preferably 0.1 to 1 part by weight, relative to 100 parts by weight of PPE. Parts by weight. The ratio of the acid anhydride used is
When the amount is 0.01 parts by weight or less relative to 100 parts by weight of PPE, the effect of improving the compatibility between PPE and nylon is small,
It is difficult to obtain a composition having toughness, and when it is used in an amount of 10 parts by weight or more, excess acid anhydride is thermally decomposed, resulting in practical inconveniences such as reduced heat resistance and poor appearance. When using an unsaturated aliphatic carboxylic acid for the modification of PPE, a radical generator such as benzoylperoxide, dicumylperoxide and cumene hydroperoxide can be used as a catalyst, if necessary. PP
The proportion of unsaturated carboxylic acid needed to modify E is PPE
It is 0.01 to 10 parts by weight with respect to 100 parts by weight.

The polyamide resin composition used as the primary molding material and / or the secondary molding material in the present invention has a total of 100 parts by weight of a crystalline polyamide resin and a thermoplastic resin other than the crystalline polyamide resin, It is preferably a polyamide resin composition containing 5 to 300 parts by weight of an inorganic filler. As the inorganic filler, a known inorganic filler can be used, and the shape is not particularly limited, and may be any of a fibrous shape, a plate shape, a needle shape, a spherical shape, and a powder. The types of inorganic fillers include glass fibers, carbon fibers, talc, mica, glass flakes, wollastonite, potassium titanate, magnesium sulfate,
Examples include sepiolite, zonolite, aluminum borate, glass beads, balun, calcium carbonate, silica, kaolin, clay, titanium oxide, barium sulfate, zinc oxide, magnesium hydroxide, and the like, or a mixture of two or more thereof. Can be used as The inorganic filler is preferably glass fiber, talc or calcium carbonate.

The blending amount of the inorganic filler is 5 to 300 parts by weight based on 100 parts by weight of the total of the crystalline polyamide resin and the thermoplastic resin other than the crystalline polyamide resin. When the amount of the inorganic filler is less than 5 parts by weight, the effect of improving the mechanical strength, thermal properties and the like is small, and when it exceeds 300 parts by weight, the processability is poor. The content of the inorganic filler is preferably 10 to 250 parts by weight, particularly preferably 50 to 150 parts by weight.
Parts by weight. In the polyamide resin composition of the present invention, in addition to the above components, various additives commonly used in polymer materials, such as stabilizers, facial dyes, release agents, lubricants, nucleating agents, weather resistance improvers, etc. Can be appropriately mixed.

As the method for producing the polyamide resin composition of the present invention, a usual method can be adopted and is not particularly limited. For example, a crystalline polyamide resin, a thermoplastic resin other than the crystalline polyamide resin, in some cases further inorganic filler, various additives, in any order, conventional equipment,
For example, a method of melt-kneading using a vent type extruder or a device similar thereto can be mentioned.

When manufacturing the integrally molded product of the present invention, molding of the secondary molding material molded on the surface of the primary molded product (hereinafter, referred to as 2
Also referred to as the next molding. The molding resin temperature in (1) is preferably higher than the melting point of the polyamide resin composition by 15 ° C. or higher, more preferably higher than the melting point by 20 ° C. or higher, and 300 ° C. or lower. 1 if the resin temperature is below 15 ° C
The surface layer of the next molded product is not sufficiently melted and the adhesiveness is apt to be lowered, and the resin is apt to be decomposed at 300 ° C or higher.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. The raw materials used in the examples and comparative examples are as follows. (1) Crystalline polyamide resin a, poly (meta-xylylene adipamide) (hereinafter referred to as nylon MXD6), manufactured by Mitsubishi Gas Chemical Co., Inc., relative viscosity (measured at a temperature of 25 ° C using 98% sulfuric acid as a solvent) 2.14. (2) Crystalline polyamide resin b, nylon 66 (relative viscosity 2.25) (3) Crystalline polyamide resin c, nylon 6 (relative viscosity 2.30)

(4) To 5 kg of modified PPE and PPE (manufactured by Mitsubishi Gas Chemical Co., Inc., intrinsic viscosity 4.45), 50 g of maleic anhydride was added, and the mixture was mixed for 3 minutes with a super mixer and then biaxial. Modified PPE (5) elastomer modified by maleic anhydride and kneaded under heating and melting at 300 ° C. by an extruder, Tuftec M1913, manufactured by Asahi Kasei Corporation. (6) Inorganic filler a, glass fiber, chopped strand, trade name CS03-JAFT2, length 3 mm, Asahi Fiber Glass Co., Ltd. (7) Inorganic filler b, mica, trade name Y-300, Takara Sangyo Co., Ltd. (8) Inorganic filler c, calcium carbonate, trade name NS-
100, Nitto Koka Kogyo Co., Ltd.

In Examples and Comparative Examples, the heat of fusion of the surface layer portion of the primary molded product and the adhesion strength of the polyamide resin integrally molded product were measured as follows. (9) Measurement of heat of fusion Using a precision low speed cutting machine (Buehler Co., Isomet), about 400 μm was cut out from the surface side of the molded primary molded product, and a differential scanning calorimeter (DSC200, manufactured by Seiko-Electronic Industries) was used. The heat of fusion was measured. (10) Adhesion strength Tensile rupture strength of the obtained integrally molded product was measured according to ASTM D638.
The adhesion strength was evaluated according to the above.

[Examples 1 to 9 and Comparative Examples 1 to 3] The crystalline polyamide resin a, the crystalline polyamide resin b and the inorganic filler a were weighed in the amounts shown in Table 1 and mixed with a tumbler,
After melt-kneading at 270 ° C. using a vent type extruder, the mixture was extruded into a string, cooled in a water tank, cut and dried to produce pellets for a primary molding material. The crystalline polyamide resin a, the crystalline polyamide resin b, and the inorganic filler a were used in the same production method to produce pellets for a secondary molding material using the amounts shown in Table 1. Using the obtained pellets for a primary molding material, a bending test piece having a length of 5 inches, a width of 1/2 inch, and a thickness of 1/4 inch was molded at a resin temperature of 260 ° C. at the time of molding and the metal shown in Table-1. Molded at mold temperature. After cutting the obtained primary molded product in half and inserting it into the cavity, the pellets for the secondary molding material are molded at the resin temperature during molding shown in Table-1.
Molding was performed at a mold temperature of 130 ° C. to manufacture an integrally molded product. Table 1 shows the evaluation results of the obtained integrally molded product.

[0024]

[Table 1]

[Examples 10 to 18, Comparative Examples 4 to 6] The crystalline polyamide resin a, the crystalline polyamide resin c and the inorganic filler a were weighed in the amounts shown in Table 2, mixed with a tumbler, and then vented. After melt-kneading at 270 ° C using an extruder, extruding into a string, cooling in a water tank, cutting and drying
Pellets for the next molding material were produced. The crystalline polyamide resin a, the crystalline polyamide resin c, and the inorganic filler a were used in the same production method to produce pellets for a secondary molding material using the amounts shown in Table 2. Using the obtained pellets for primary molding materials, length 5 inches, width 1/2 inch, thickness 1/4
Inch bending test pieces were molded at a resin temperature of 260 ° C. at the time of molding and a mold temperature shown in Table 2. After cutting the obtained primary molded product in half and inserting it into the cavity, the secondary molding pellets are molded at the resin temperature at the time of molding shown in Table-2 at a mold temperature of 130 ° C. A molded product was produced. Table 2 shows the evaluation results of the obtained integrally molded product.

[0026]

[Table 2]

[Examples 19 to 24, Comparative Examples 7 to 9] The crystalline polyamide resin a, the crystalline polyamide resin b, the crystalline polyamide resin c, the inorganic filler a, the inorganic filler b and the inorganic filler c are shown. -3 is weighed, mixed with a tumbler, melt-kneaded at 270 ° C. using a vent type extruder, extruded into a string, cooled in a water tank, cut and dried to obtain 1
Pellets for the secondary molding material and the secondary molding material were produced. Using the obtained pellets for primary molding material, length 5
A bending test piece having an inch, a width of ½ inch, and a thickness of ¼ inch was molded at a resin temperature of 260 ° C. at the time of molding and a mold temperature shown in Table-3. After cutting the obtained primary molded product in half and inserting it into the cavity, the secondary molding pellets were molded at a molding temperature of 130 at the resin temperature during molding shown in Table 3.
Molded at ℃, to produce an integrally molded product. Table 3 shows the evaluation results of the obtained integrally molded product.

[0028]

[Table 3]

[Examples 25 to 33, Comparative Examples 10 to 12]
Table 4 shows crystalline polyamide resin a, crystalline polyamide resin b, modified PPE, elastomer, and inorganic filler a.
After weighing and mixing with a tumbler, the mixture was melt-kneaded at 270 ° C. using a vent type extruder, and then extruded into a string,
After cooling in a water tank, it was cut and dried to produce pellets for a primary molding material. Further, the crystalline polyamide resin a, the crystalline polyamide resin b, and the inorganic filler a were weighed in the amounts shown in Table 4, and pellets for a secondary molding material were manufactured in the same manner. Using the obtained pellets for the primary molded product, a bending test piece having a length of 5 inches, a width of 1/2 inch and a thickness of 1/4 inch was prepared, and the resin temperature at the time of molding was 260 ° C. Molded at mold temperature. The obtained primary molded product is cut in half and inserted into the cavity, and then the secondary molding pellets are exposed.
At the molding resin temperature shown in 4, the mold temperature is 130 ° C.
Was molded to produce an integrally molded product. Table 4 shows the evaluation results of the obtained integrally molded product.

[0030]

[Table 4]

[0031]

The polyamide resin integrally molded product of the present invention does not require application of an adhesive or a primer to the surface of the primary molded product and the secondary molded product formed on the surface of the primary molded product. Excellent adhesion strength with molding material. Further, by molding a secondary molding material on a bobbin part or the like in which a coil is wound around a primary molded product, various functions such as various sensors can be imparted, and the polyamide resin integrally molded product of the present invention. Is
Extremely useful.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C08L 77/00 LQR C08L 77/00 LQR LQV LQV LQW LQW 101/00 LTA 101/00 LTA // (C08L 77 / 00 71:12) B29K 77:00

Claims (5)

[Claims] 1. A crystalline polyamide resin of 50 to 100% by weight and a thermoplastic resin other than the crystalline polyamide resin of 0 to 50.
On the surface of the primary molded article obtained by molding a primary molding material which is a polyamide resin composition consisting of 10% by weight and the heat of fusion of the layer up to 500 μm is 20 mj / mg or less,
An integrally molded product made of a polyamide resin obtained by molding a secondary molding material which is a polyamide resin composition comprising 50 to 100% by weight of a crystalline polyamide resin and 0 to 50% by weight of a thermoplastic resin other than the crystalline polyamide resin. 2. The polyamide resin, wherein the crystalline polyamide resin is obtained from xylylenediamine and α, ω-linear aliphatic dibasic acid, or xylylenediamine and α, ω.
The polyamide resin integrally molded product according to claim 1, which is a polyamide resin obtained from a linear aliphatic dibasic acid and a resin of nylon 66 and / or nylon 6. 3. The polyamide resin integrally molded product according to claim 1, wherein the thermoplastic resin is a polyphenylene ether resin. 4. The polyamide resin composition is a polyamide resin composition containing 5 to 300 parts by weight of an inorganic filler with respect to a total of 100 parts by weight of a crystalline polyamide resin and a thermoplastic resin other than the crystalline polyamide resin. The polyamide resin integrally molded product according to any one of claims 1 to 3, which is characterized by being present. 5. The integrally molded product made of polyamide resin according to claim 4, wherein the inorganic filler is glass fiber, talc or calcium carbonate.