JPH10180878A - Method of manufacturing vibration welded molded product made of polyamide resin - Google Patents

Abstract

(57) [Problem] To provide a method for producing a vibration-welded molded product made of polyamide resin having high welding strength. A method for producing a vibration-welded molded article made of a polyamide resin, wherein a temperature at the time of vibration welding of a plurality of molded articles primarily formed using a polyamide resin is set to 50 ° C. or higher and lower than a melting point of the polyamide resin. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a vibration-welded molded article made of a polyamide resin, and more particularly, to a vibration-welded molding of a polyamide resin in which a plurality of primary molded articles are integrated by a vibration welding method. The present invention relates to a method for manufacturing a product.

[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, according to the conventional manufacturing method, even if the primary molded article is welded by the vibration welding method, a sufficiently satisfactory welding strength cannot be obtained. For example, an intake of an automobile engine in which the vibration welded molded article is a hollow body molded article. In the case of a manifold, sufficient pressure resistance cannot be obtained, and when the internal pressure increases due to an engine backfire or the like, there is a risk of rupture.Therefore, design changes such as an increase in welding area are often required. Was.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a vibration-welded molded article made of a polyamide resin having a high welding strength.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist of the present invention is to determine the temperature at the time of vibration welding of a plurality of molded products which are primarily molded using a polyamide resin. The present invention provides a method for producing a vibration-welded molded article made of a polyamide resin, wherein the temperature is 50 ° C. or higher and lower than the melting point of the polyamide resin.

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 It is. Specifically, ω-amino acids as raw materials include ε-aminocaproic acid, 7-aminoheptanoic acid,
-Aminononanoic acid, 11-aminoundecanoic acid, 12-
Aminododecanoic acid; As lactams,
ε-caprolactam, enantholactam, caprylactam, lauryl lactam, α-pyrrolidone, α-piperidone.

Examples of the dibasic acids include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecadionic acid, hexadecadionic acid, hexadecenedionic acid, eicosandioic acid, and eicosadi. Endionic acid, diglycolic acid, 2,
Examples include 2,4-trimethyladipic acid, xylylenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, and isophthalic acid.

[0007] 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.

[0008] The polyamide resin used in the present invention is preferably 6 nylon, 66 nylon or 66 nylon.
/ 6 copolymerized nylon. Further, a plurality of the above-mentioned polyamide resins may be used.

The polyamide resin in the present invention preferably has a degree of polymerization within an appropriate range, that is, a resin having a relative viscosity within a certain range. The relative viscosity of the polyamide resin is determined by JI
S 1% concentration in 98% sulfuric acid according to K6810 of S, temperature 2
The value measured at 5 ° C. is preferably 2.0 to 4.0, more preferably 2.5 to 3.7. If the relative viscosity is low, the welding strength will be low, and if it is too high, the fluidity will be impaired and the surface smoothness will be poor.

In the present invention, the glass fibers used when the polyamide resin is a glass fiber reinforced polyamide resin may be those usually used in thermoplastic resins, and may be chopped made of E glass (alkali-free glass). Strands are preferred. The fiber diameter of the glass fiber is preferably 1 to 20 μm, more preferably 5 μm.
１５15 μm. The glass fiber is preferably surface-treated with a silane coupling agent or the like to improve the adhesion to the polyamide. The compounding amount of the glass fiber is preferably 10 to 60% by weight of the glass fiber reinforced polyamide resin, more preferably 20 to 50% by weight, and further preferably 30 to 40% by weight. If the amount is too small, the welding strength is reduced, and if it is too large, the surface smoothness tends to be impaired.

In the polyamide resin of the present invention, inorganic fillers other than glass fibers, for example, glass flakes, glass beads, and the like, as long as the effects of the present invention are not impaired.
Mica, talc, kaolin, wollastonite, potassium titanate whiskers and 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 can be carried out at any stage from polymerization of the resin to molding, but it is preferable to carry out melt kneading using an extruder.

In the present invention, first, a plurality of components are firstly molded using a polyamide resin. 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 shape of the plurality of molded products obtained by the primary molding in the present invention may be any shape having a joining surface that can be welded by vibration welding,
The plurality of molded products 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 three-way tube which is a hollow body shown in FIG. 4 is cut in the longitudinal direction. Shaped molded articles are exemplified.

In the manufacturing method of the present invention, when a plurality of primary molded products are welded by vibration welding, the temperature of the primary molded product (sometimes referred to as a primary molded product) at the time of vibration welding is set to 50. The temperature is set to not less than 0 ° C. and lower than the melting point of the polyamide resin used for the primary molded product, and the primary molded product is welded and joined to obtain the desired vibration-welded molded product made of the polyamide resin.

If the temperature during vibration welding of the primary molded product is low,
If the effect of improving the welding strength is small and the temperature at the time of vibration welding of the primary molded product exceeds its melting point, the molded product is undesirably melted. The temperature during vibration welding of primary molded products is
Preferably, the temperature is 70 ° C. or higher and 10 ° C. or lower than the melting point of the polyamide resin used for the primary molded product, and more preferably 80 ° C. or higher, and 20 ° C. or lower than the melting point of the polyamide resin used for the primary molded product. It is.

If the temperature of the primary molded product during vibration welding is within the above range, the temperature of the atmosphere in which the vibration welding is performed may be within the above temperature range. Temperature range. Immediately after the primary molding, vibration welding can be performed while the temperature of the molded product is within the above range.

The frequency of vibration in vibration welding is preferably 100 to 300 Hz, and the amplitude is preferably 0.5 to 2.0 mm, more preferably 0.8 to 2.0 mm.
1.6 mm, and the welding pressure is preferably 5 to 100
kg / cm ² . The welding time that should be under a predetermined pressure is appropriately set so as to obtain a desired melting margin, and the holding pressure and the holding time after stopping the vibration are appropriately 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.

The polyamide resins used in the following Examples and Comparative Examples are as follows.

(1) 6 nylon: NOVAMID1015J manufactured by Mitsubishi Engineering-Plastics Corporation.
Relative viscosity 3.0. (2) 66 nylon: Zytel 101NC manufactured by DuPont
10. Relative viscosity 3.0. (3) 66/6 copolymerized nylon: a copolymerized nylon having a 9: 1 molar ratio of AH salt (salt of adipic acid and hexamethylenediamine) and ε-caprolactam and a melting point of 245 ° C. Relative viscosity 3.0.

The method for evaluating the vibration welding strength is as follows. (4) Test piece for measuring welding strength: Injection molding is performed under the conditions described in the following examples to obtain two primary molded articles having the same shape as 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. (5) Measuring method of welding strength: This vibration-welded molded product is manufactured by Orientec Co., Ltd. using 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 50 mm, and the breaking strength at the welded portion was defined as the weld strength.

[Example 1] Polyamide resin shown in Table 1 was added to glass fiber (trade name T, manufactured by NEC Corporation).
283H) to 35% by weight to obtain a glass fiber reinforced polyamide resin composition. For the compounding, a twin-screw kneader was used, and the set temperature was 280 ° C.

The obtained glass fiber reinforced polyamide resin composition was molded at a set temperature of 260 ° C. and a set mold temperature of 8 using an FS160S type injection molding machine manufactured by Nissei Plastics Industry Co., Ltd.
At 0 ° C., two primary molded articles of the same shape shown in FIG. 1 were obtained. A pair of primary molded products warmed in a hot air drying oven,
It was fixed with a vibration welding jig, and the temperature of the primary molded product was measured with a surface thermometer immediately before performing the vibration welding. Table 1 shows the measurement results.

[0022] A pair of the primary molded products is used as a vibration welding machine (Vibration Weld) manufactured by Emerson Japan.
ER Model 2800) using frequency 24
0 Hz, welding pressure 15.5 kg / cm ² , amplitude 1.5 m
m, welding margin 1.5 mm, holding pressure: welding pressure 15.5 kg / cm ² after stopping vibration, holding time 5.0 sec, to obtain a vibration welded molded product shown in FIG. To control the melting allowance, CX132 manufactured by Emerson Japan
A mold 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.

Example 2 The temperature of the primary molded product was set to 140 ° C.
A vibration welded molded product was obtained under the same conditions as in Example 1, except that the welding strength was measured. Table 1 shows the measurement results. Example 3 Example 1 was repeated except that the polyamide resin was made of glass fiber reinforced 66 nylon (glass fiber content 35% by weight), the injection molding temperature was set at 280 ° C., and the temperature of the primary molded product was 140 ° C. Under the same conditions as described above, a vibration-welded molded product was obtained, and the welding strength was measured. Table 1 shows the measurement results.

Example 4 A polyamide resin was made of glass fiber reinforced 66/6 copolymerized nylon (glass fiber content: 35% by weight), the injection molding temperature was set to 280 ° C., and the temperature of the primary molded product was set to 140 ° C. Except for the above, a vibration-welded molded product was obtained under the same conditions as in Example 1, and the welding strength was measured. Table 1 shows the measurement results. Comparative Example 1 A vibration welded molded product was obtained under the same conditions as in Example 1 except that the temperature of the primary molded product was set to 23 ° C., and the welding strength was measured. Table 1 shows the measurement results.

Comparative Example 2 A vibration-welded molded product was obtained under the same conditions as in Example 3 except that the temperature of the primary molded product was 23 ° C., and the welding strength was measured. Table 1 shows the measurement results. [Comparative Example 3] A vibration welded molded product was obtained under the same conditions as in Example 4 except that the temperature of the primary molded product was set to 23 ° C.
The welding strength was measured. Table 1 shows the measurement results.

[0026]

[Table 1]

[0027]

The welding strength of the vibration-welded molded article made of a polyamide resin obtained by the method of the present invention is remarkably improved, and the vibration-welded molded article can be applied to various fields.
It is particularly useful as a method for manufacturing an intake manifold for an automobile that requires 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

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 06 B29L 23:00 (72) Inventor Tatsuya Hitomi 370, Enzo 370, Chigasaki-shi, Kanagawa Mitsubishi Engineering-Plastics Corporation In the center

Claims (4)

[Claims] 1. A method of manufacturing a vibration-welded molded article made of a polyamide resin, wherein a temperature of a plurality of molded articles formed by primary molding using a polyamide resin at the time of vibration welding is set to 50 ° C. or higher and lower than the melting point of the polyamide resin. Method. 2. The method according to claim 1, wherein the polyamide resin is 6 nylon, 66 nylon, or 66/6 copolymerized nylon. 3. The method according to claim 1, wherein the polyamide resin is a glass fiber reinforced polyamide resin. 4. The method for producing a vibration-welded polyamide resin article according to claim 1, wherein the vibration-welded molded article made of a polyamide resin is a hollow body molded article.