JPH10315332A - Vibration welding molded form made of polyamide resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration welding molded form made of polyamide resin which is excellent in molded appearance as well as welding strength. SOLUTION: A molded form is obtained through primary molding employing polyamide resin composition, consisting of 100 pts.wt of mixed resin, constituted of (A) 20-95 wt.% of polyamide resin having relative viscosity of 2.0-3.0 and (B) 80-5 wt.% of polyamide resin having relative viscosity of 5.1-7.0, and blended with (C) 10-100 pts.wt of glass fiber. The molded form is made by effecting the vibration welding of a plurality of obtained molded forms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-welded molded article made of a polyamide resin, and more particularly to a vibration-welded molded article of a polyamide resin obtained by joining a plurality of primary molded articles by vibration welding. Things.

[0002]

2. Description of the Related Art In recent years, applications of plastics have been expanded,
Taking advantage of this property, various industrial products, such as intake manifolds for automobile engines, have been converted into resins by the vibration welding method. As a material for resinification, glass fiber reinforced 66 nylon or glass fiber reinforced 6 nylon is used.

However, in the conventional method, even if the primary molded article is welded by the vibration welding method, a satisfactory welding strength cannot be obtained. For example, an automobile engine in which the vibration weld molded article is a hollow body molded article In the case of the intake manifold described above, sufficient pressure resistance cannot be obtained, and the intake manifold may be damaged when the internal pressure increases due to backfire of the engine or the like. For this reason, as a means for improving the welding strength, a method of increasing the relative viscosity of the polyamide resin to be used, a method of increasing the welding area, and the like are known. When a primary molded product was obtained by increasing the injection pressure, the molded product was greatly warped and vibration welding was difficult, and the latter required a design change.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration-welded molded article made of a polyamide resin having excellent welding strength by using a highly fluid polyamide resin.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its gist is as follows.
Mixed resin 1 comprising (A) 20 to 95% by weight of a polyamide resin having a relative viscosity of 2.0 to 3.0 and (B) 80 to 5% by weight of a polyamide resin having a relative viscosity of 5.1 to 7.0.
A vibration-welded molded article of a polyamide resin obtained by vibration-welding a plurality of molded articles which are primarily molded using a polyamide resin composition obtained by blending 10 to 100 parts by weight of (C) glass fiber with respect to 00 parts by weight.

Hereinafter, the present invention will be described in detail. As the polyamide resin in the present invention, a polymerizable ω-amino acid or a lactam thereof, preferably a lactam having three or more ring members, or a polyamide resin obtained by polycondensation of a dibasic acid and a diamine as a raw material Is mentioned. Examples of ω-amino acids include ε-aminocaproic acid, 7-aminoheptanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid. Lactams include ε-caprolactam, enantholactam, caprylactam, lauryl lactam, α-pyrrolidone and α-piperidone.

The dibasic acids include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, undecandionic acid, dodecadionic acid, hexadecadionic acid, hexadecenedionic acid, eicosandioic acid , Eicosadienedioic acid, diglycolic acid, 2,2,4-trimethyladipic acid, xylylenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,
Terephthalic acid and isophthalic acid;

The diamines include hexamethylenediamine, tetramethylenediamine, nonamethylenediamine, undecamethylenediamine, dodecamethylenediamine, 2,2,4 (or 2,4,4) -trimethylhexamethylenediamine, bis-methylenediamine, and bis-methylenediamine. (4,4'-aminocyclohexyl) methane and meta-xylylenediamine.

As the polyamide resin in the present invention,
Preferably, 6 nylon, 66 nylon, 66/6 copolymer nylon or the like is used, and more preferably, 6 nylon is used. Further, a plurality of the above-mentioned polyamide resins may be used.

The polyamide resin in the present invention includes:
It is a mixed resin of (A) a polyamide resin having a relative viscosity of 2.0 to 3.0 and (B) a polyamide resin having a relative viscosity of 5.1 to 7.0. Here, the relative viscosity is defined by JIS
According to K6810 98% sulfuric acid concentration 1%, temperature 25
It is a value measured at ° C. If the relative viscosity of the polyamide resin (A) is too low, the welding strength will be low, and if it is too high, the fluidity will decrease. The relative viscosity of the polyamide resin (A) is preferably 2.2 to 2.6.
If the relative viscosity of the polyamide resin (B) is too low, the welding strength will be low, and if it is too high, the fluidity will decrease.
The relative viscosity of the polyamide resin (B) is preferably 5.2 to 7.0, and more preferably 5.3 to 6.8.
It is.

The relative viscosity M of the polyamide resin (B)
The ratio M _H / M _L between the relative viscosity M _L of _H and the component (A) of the polyamide resin is preferably 2.0 or more. If M _H / M _L is less than 2.0, the welding strength and the fluidity are likely to decrease. The ratio M _H / M _L is more preferably 2.1 or more.

The compounding ratio of the polyamide resin (A) to the polyamide resin (B) is 20 to 95 parts by weight /
80 to 5 parts by weight. If the blending ratio of the polyamide resin (A) is less than 20 parts by weight, the fluidity tends to decrease, and if it exceeds 95 parts by weight, the welding strength tends to decrease.
The mixing ratio of the polyamide resin (A) to the polyamide resin (B) is preferably 30 to 70 parts by weight / 7.
0 to 30 parts by weight.

The glass fibers in the present invention may be those usually used for thermoplastic resins, and preferably include chopped strands made of E glass (non-alkali glass). Fiber diameter of glass fiber is 1
To 20 μm, preferably 5 to 15 μm. As the glass fiber, a glass fiber that has been surface-treated with a silane coupling agent or the like to improve the adhesion to the polyamide resin is preferable.

The compounding amount of the glass fiber is 10 to 100 parts by weight based on 100 parts by weight of the mixed resin composed of the polyamide resin (A) and the polyamide resin (B). If the amount of the glass fiber is less than 10 parts by weight, the welding strength decreases, and if it exceeds 100 parts by weight, the fluidity decreases. The blending amount of the glass fiber is a mixed resin 10 composed of the polyamide resin (A) and the polyamide resin (B).
The amount is preferably 20 to 80 parts by weight, more preferably 30 to 70 parts by weight, based on 0 parts by weight.

In the polyamide resin composition of the present invention, inorganic fillers other than glass fibers, such as glass flakes, glass beads, mica, talc, kaolin, wollastonite, and the like, as long as the effects of the present invention are not impaired
A potassium titanate whisker or the like may be blended. Further, known additives such as a heat stabilizer such as a copper compound, a releasing agent, and a coloring agent such as carbon black may be blended. These blending is carried out at any stage from the polymerization of the resin to the molding, but it is preferable to carry out melt-kneading using an extruder.

In the vibration-welded molded product made of a polyamide resin of the present invention, first, a plurality of parts are each first molded using a polyamide resin composition. As a molding method of a molded article obtained by primary molding, a molding method generally used in molding of a thermoplastic resin is applied, and preferably, an injection molding method is used. The plurality of molded products obtained by the primary molding in the present invention may have the same shape or different shapes from each other, for example, a molded product having a shape as shown in FIG. 1 or a hollow body as shown in FIG. A molded product having a shape shown in FIG. 3 in which a three-way tube is cut in a longitudinal direction is exemplified.

Next, the plurality of primary molded products are joined by vibration welding to obtain a polyamide resin vibration welded molded product. The frequency of vibration in vibration welding is 100 to 3
00 Hz, and the amplitude is 0.5 to 2.0 mm, preferably 0.8 to 1.6 mm. The welding pressure is 5
100 kg / cm ² , preferably 10 to 60 kg
/ Cm ² . If the welding pressure is too high or too low, the welding strength will decrease. The welding time, which should be under a predetermined pressure, is set so that the desired melting allowance is obtained,
The holding time after releasing the pressure is set so that the welded portion is sufficiently solidified.

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 it exceeds the gist of the present invention.

The polyamide resin used in the following Examples and Comparative Examples was 6 nylon (NOVAMID,
(Mitsubishi Engineering Plastics Co., Ltd.) and Table 1 shows the relative viscosity.

The method for evaluating the vibration welding strength is as follows. (1) Test piece for measuring welding strength: Injection molding is performed under the conditions described in the examples described below to obtain two primary molded articles having the same shape shown in FIG. Subsequently, vibration welding was performed under the conditions described in Examples described later to obtain a vibration welded molded product shown in FIG. (2) Measuring method of welding strength: This vibration-welded molded product was manufactured using Orientec Co., Ltd. Tensilon UTM-III-50.
Using a 0-type testing machine, tension was applied under the conditions of a tensile speed of 5 mm / min and a distance between chucks of 80 mm, and the breaking strength at the welded portion was defined as the weld strength.

[Examples 1 and 2, Comparative Examples 1 to 3] 43 parts by weight of glass fiber (trade name: T249GH, manufactured by Nippon Electric Glass Co., Ltd.) was added to 100 parts by weight of the total amount of the polyamide resins shown in Table 1. did. For the compounding, a TEM-35B type twin screw kneader manufactured by Toshiba Machine Co., Ltd. was used, and the set temperature was 280.
° C. The obtained glass fiber reinforced polyamide resin composition was heated at a set temperature of 260 ° C. and a set mold temperature of 80 ° C. using an IS80EPN-2A type injection molding machine manufactured by Toshiba Machine Plastic Engineering Co., Ltd.
Two primary molded articles of the same shape were obtained.

Next, a pair of the primary molded products is used as a VIBRATION WELDER manufactured by Emerson Japan.
Using a Model 2800 vibration welding machine, the frequency was 240 Hz, the welding pressure was 15.5 kg / cm ² , and the amplitude was 1.
5 mm, melting margin 1.5 mm, Hold pressure: pressure 15.5 kg / cm ² after stopping vibration, holding time 5.0 sec
To obtain a vibration welded molded product shown in FIG. CX made by Emerson Japan, Inc. to control the melting allowance
A 132 type non-contact WDC welding size control device was used. Table 1 shows the measurement results of the welding strength of the obtained vibration welding molded product.

The obtained glass fiber reinforced polyamide resin composition was set using an IS80EPN-2A type injection molding machine and a spiral mold (molded product thickness: 3.0 mm) manufactured by Toshiba Kikai Plastics Engineering Co., Ltd. At a temperature of 260 ° C, a set mold temperature of 80 ° C, and an injection pressure of 10
Molding was performed at 00 kg / cm ² , and the flow length was measured. Table 1 shows the measurement results.

[0023]

[Table 1]

[0024]

The polyamide resin composition used in the polyamide resin vibration welded molded article of the present invention is excellent in fluidity, and even when a primary molded article having a relatively complicated shape is formed, warping or the like is required. It is easy to obtain molded products with less molding defects.Vibration welding molded products made of polyamide resin obtained by vibration welding such molded products have excellent molding appearance and excellent welding strength, and are suitable for molded products in various fields. It is effective and is particularly useful as an intake manifold for automobiles, etc., which require high safety.

[Brief description of the drawings]

FIG. 1 shows the shape of a primary molded product (60 mm × 25 mm × 4 m
Explanatory diagram showing an example of m)

FIG. 2 is an explanatory view showing an example of the shape of a vibration welding molded product.

FIGS. 3A and 3B are plan views showing examples of shapes of a pair of hollow body molded products.

FIG. 4 is a conceptual diagram showing an example of a vibration-welded hollow body molded product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Welding surface 2, 2 'Upper opening 3 Lower opening

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29L 22:00 23:00 (72) Inventor Tatsuya Hitomi 5-6-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Mitsui Engineering Plastics Co., Ltd. Inside the company technology center

Claims (4)

[Claims] 1. (A) 20 to 95% by weight of a polyamide resin having a relative viscosity of 2.0 to 3.0, and (B) 80 to 5% by weight of a polyamide resin having a relative viscosity of 5.1 to 7.0. (C) glass fiber 1 with respect to 100 parts by weight of the mixed resin comprising
A vibration-welded molded product made of a polyamide resin obtained by vibration-welding a plurality of molded products which are primarily molded using a polyamide resin composition containing 0 to 100 parts by weight. Wherein (B) Relative Viscosity Relative viscosity and relative viscosity M _H of the polyamide resin is 5.1 to 7.0 (A) Polyamide resin relative viscosity M is 2.0 to 3.0 M _The vibration-welded molded article made of a polyamide resin according to claim 1, wherein the ratio _MH / ML to _L is 2.0 or more. 3. The vibration-welded molded article made of polyamide resin according to claim 1, wherein the polyamide resin is nylon 6, nylon 66 or nylon 6/66 copolymer. 4. The vibration-welded molded article made of a polyamide resin according to claim 1, wherein the vibration-welded molded article made of a polyamide resin is a hollow body molded article.