JP2001026656A - Preparation of molded article by welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molded article having a wide range of welding conditions and an excellent weld strength. SOLUTION: A molded article is produced by unifying through welding, on to another molded article (B), an molded article (A) made from at least one type of polyester-derived copolymer selected from the group consisting of a PBT(polybutylene terephthalate)-derived copolymer having an m.p. in the range of 170-220 deg.C, a PBN(polybutylene naphthalate)-derived copolymer having an m.p. in the range of 190-240 deg.C, a PET(polyethylene terephthalate)-derived copolymer having an m.p. in the range of 200-250 deg.C and a PEN(polyethylene naphthalate)-derived copolymer having an m.p. in the range of 210-260 deg.C.

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 molded product obtained by welding such as laser welding, vibration welding, ultrasonic welding, and hot plate welding.

[0002]

2. Description of the Related Art Polybutylene terephthalate (PB)
T), thermoplastic polyester resins represented by polybutylene naphthalate (PBN), polyethylene terephthalate (PET), and polyethylene naphthalate (PEN) are heat-resistant, chemical-resistant, electrical, mechanical, and molding fluidity. Automotive parts (various control units, ignition coil parts), motor parts, various sensor parts, connector parts, switch parts, relay parts, coil parts, transformer parts, lamp parts, etc., automotive field, electric and electronic fields Widely used for. In assembling these parts, methods such as adhesives, screws, and heat welding have been used. Here, the adhesive often requires a time loss until it is hardened or requires a fixing jig, which leads to a problem of cost increase and the use of a solvent from the viewpoint of environmental protection. In addition, the cost of insert nuts, screws, washers, and the like, the time required for fastening, and an increase in weight have become problems in screwing.

[0003] On the other hand, welding typified by laser welding, vibration welding, ultrasonic welding, hot plate welding, and the like can be joined in a short time and do not use metal parts such as adhesives and screws. Since no problems such as cost increase, weight increase and environmental pollution occur, assembly by this method is increasing. However, the PB used in the above parts
Thermoplastic polyester resins represented by T, PBN, PET, and PEN have excellent heat resistance, but have a high melting point and are hard to be softened and melted, so the processing condition width during welding is narrow, and the control of the processing conditions is strict. In some cases, sufficient bonding strength may not be exhibited depending on the processing conditions, and this has a problem in production.

Here, as a joining method of the synthetic resin material,
Japanese Patent Publication No. 62-53818 proposes a joining method using a laser beam, but the process is complicated and there is a limit in improving mass productivity. Also, JP-A-10-159
No. 89, in a double molding method or a two-color molding method in which a resin is further formed on a primary molded product and a part of the primary molded product is melted and fixed by the heat, PBT is applied to the primary molded product. It has been proposed that the use of a system copolymer improves the adhesion between the primary molded product and the secondary molded product, but is typified by laser welding, vibration welding, ultrasonic welding, and hot plate welding. There is no mention of a welding method.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser welding, vibration welding, ultrasonic welding, or the like, of molded articles made of polyester copolymers represented by at least one of PBT, PBN, PET and PEN. An object of the present invention is to provide a molded article having a wide range of welding conditions and excellent welding strength when integrated by a welding method represented by hot plate welding or the like.

[0006]

The gist of the present invention is to provide a PBT copolymer having a melting point in the range of 170 to 220 ° C, a PBN copolymer having a melting point in the range of 190 to 240 ° C, and a melting point of 200 to 250 ° C. Molded article (A) comprising at least one polyester-based copolymer (a) selected from a PET-based copolymer having a melting point in the range of 210 to 260 ° C. This is a method of manufacturing a molded article by integrating the molded article (B) with the molded article by welding.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

In the present invention, the molded article (A) has a melting point of 1
PBT copolymer having a melting point of 1 to 70 to 220 ° C.
PBN copolymer having a melting point of 90 to 240 ° C.
At least one polyester-based copolymer (a) selected from a PET-based copolymer having a temperature in the range of 00 to 250 ° C and a PEN-based copolymer having a melting point in the range of 210 to 260 ° C;
Manufactured from

PBT having a melting point in the range of 170 to 220 ° C.
The copolymer is mainly composed of a terephthalic acid component and a 1,4-butanediol component, and controls a melting point by copolymerizing another dicarboxylic acid component and a diol component.

PBN having a melting point in the range of 190 to 240 ° C.
The copolymer is mainly composed of a 2,6-naphthalenecarboxylic acid component and a 1,4-butanediol component, and controls the melting point by copolymerizing another dicarboxylic acid component and a diol component.

PET having a melting point in the range of 200 to 250 ° C.
The copolymer is mainly composed of a terephthalic acid component and an ethylene glycol component, and its melting point is controlled by copolymerizing another dicarboxylic acid component and a diol component.

PEN having a melting point in the range of 210 to 260 ° C.
The copolymer is mainly composed of a 2,6-naphthalenecarboxylic acid component and an ethylene glycol component, and controls the melting point by copolymerizing another dicarboxylic acid component and a diol component.

Other dicarboxylic acid components include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,4
-Naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bis (P-carboxyphenyl) methane, anthracenedicarboxylic acid 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, Sebacic acid and dotecanedioic acid (however, except for terephthalic acid for PBT and PET and 2,6-naphthalenecarboxylic acid for PBN and PEN).

The diol component includes 2 to 10 carbon atoms such as ethylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol and cyclohexanedimethanol. Aliphatic diol, polyethylene glycol, poly 1,3-propylene glycol,
The molecular weight of polytetramethylene glycol or the like is 400 to 6
000 long-chain glycol, hydroquinone, resorcinol, dihydroxyphenyl, naphthalene diol, dihydroxydiphenyl ether, cyclohexanediol, 2,2 bis (4-hydroxyphenyl) propane,
Relatively low molecular weight hydroxy compounds such as diethoxylated bisphenol A, and their alkyl, alkoxy or halogen substituted compounds (however, 1,4-butanediol for PBT and PBN, ethylene glycol for PET and PEN) Are excluded).

Examples of the oxycarboxylic acid as the third component include oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid and diphenyleneoxycarboxylic acid, and alkyl, alkoxy or halogen substituted products thereof. Can be Also, ester-forming derivatives of these compounds can be used.

In addition to these, a small amount of a trifunctional monomer for forming the polyester copolymer (a), that is, trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, trimethylolpropane, or the like is used in a small amount. It may be a copolymer having a branched or crosslinked structure.

These copolymer components may be those obtained by mixing and introducing two or more kinds.

These polyester copolymers (a) are:
It can be obtained by a condensation reaction of a monomer containing an aromatic dicarboxylic acid or an ester-forming derivative thereof and a diol or an ester-forming derivative thereof as main components.

The PBT component of the PBT copolymer is desirably at least 70 mol%.

The melting point of the PBT copolymer is 170
C. to 220.degree. C. range is desirable. 170 ° C-220 melting point
The melting temperature of PBT-based copolymer in the range of ℃ is lower than that of PBT polymer with melting point of 227 ℃, and the joining surface is melted by laser welding, vibration welding, ultrasonic welding, hot plate welding, etc. In the case of melting, it is possible to melt with lower melting energy. Also, as in the case of the laser welding method, the molded product (A) and another molded product (B) are overlapped, and a laser beam is irradiated from one side and the laser light is transmitted through the molded product. But the melting point is 170 ° C ~
A PBT copolymer in the 220 ° C. range has a lower crystallinity and a higher light transmittance than a PBT polymer having a melting point of 227 ° C., and thus can be melted with lower melting energy. Joining with low melting energy improves welding strength, broadens the welding conditions, increases the degree of freedom in the joint surface = the shape of the molded product, and extends the life of the welding device because the welding device output can be set low. There are advantages such as expectation. The PBN component of the PBN-based copolymer is desirably 70 mol% or more.

The melting point of the PBN copolymer is 190
C. to 240.degree. C. range is desirable. 190 ° C to 240 melting point
The melting point of the PBN copolymer in the range of ℃ is lower than that of the PBN polymer with the melting point of 247 ° C, and the joint surface is melted by laser welding, vibration welding, ultrasonic welding, hot plate welding, etc. In the case of melting, it is possible to melt with lower melting energy. Also, as in the case of the laser welding method, the molded product (A) and another molded product (B) are overlapped, and a laser beam is irradiated from one side and the laser light is transmitted through the molded product. But the melting point is 190 ° C ~
PBN-based copolymer in the 240 ° C range has a melting point of 247 ° C.
Compared to a BN polymer, it has a lower degree of crystallinity and a higher light transmittance, so that it can be melted with lower melting energy. Joining with low melting energy improves welding strength, broadens the welding conditions, increases the degree of freedom of the joint surface = the shape of the molded product, and extends the life of the welding device because the welding device output can be set low. There are advantages such as expectation.

It is desirable that the PET component of the PET copolymer is at least 70 mol%.

Here, the melting point of the PET copolymer is 200
C. to 250 C. is desirable. Melting point 200 ° C ~ 250
The melting point of PET-based copolymer in the range of ° C is lower than that of PET polymer with a melting point of 257 ° C, and the joining surface is melted by laser welding, vibration welding, ultrasonic welding, hot plate welding, etc. In the case of melting, it is possible to melt with lower melting energy. Also, as in the case of the laser welding method, the molded product (A) and another molded product (B) are overlapped, and a laser beam is irradiated from one side and the laser light is transmitted through the molded product. But the melting point is 200 ° C ~
PET copolymers in the 250 ° C range have a melting point of 257 ° C.
Since it has a lower crystallinity and a higher light transmittance than the ET polymer, it can be melted with lower melting energy. Joining with low melting energy improves welding strength, broadens the welding conditions, increases the degree of freedom of the joint surface = the shape of the molded product, and extends the life of the welding device because the welding device output can be set low. There are advantages such as expectation. The PEN component of the PEN-based copolymer is desirably 70 mol% or more.

The melting point of the PEN copolymer is 210
C. to 260 C. is desirable. 210 ° C-260 melting point
The melting temperature of PEN-based copolymer in the range of ℃ is lower than that of PEN polymer with melting point of 268 ° C, and the joint surface is melted by laser welding, vibration welding, ultrasonic welding, hot plate welding, etc. In the case of melting, it is possible to melt with lower melting energy. Also, as in the case of the laser welding method, the molded product (A) and another molded product (B) are overlapped, and a laser beam is irradiated from one side and the laser light is transmitted through the molded product. But the melting point is 210 ° C ~
PEN copolymers in the 260 ° C range have a melting point of 268 ° C.
Since the degree of crystallinity is low and the light transmittance is high as compared with the EN polymer, it can be melted with lower melting energy. Joining with low melting energy improves welding strength, broadens the welding conditions, increases the degree of freedom in the joint surface = the shape of the molded product, and extends the life of the welding device because the welding device output can be set low. There are advantages such as expectation.

In the present invention, the polyester copolymer (a) may be used as a molded article by mixing one or more kinds. In the present invention, the polyester copolymer (a)
Has a mechanical strength, as long as the effect of the present invention is not impaired.
For the purpose of improving rigidity, heat resistance, dimensional stability, electrical properties, etc., glass fibers, inorganic fibers other than glass fibers, metal fibers, carbon fibers, fibrous reinforcing materials such as heat-resistant organic fibers, mica, sericite, Plate-like fillers such as glass flakes, silicates such as talc, kaolin, clay, wollastonite, bentonite, asbestos, and alumina silicate; metal oxides such as alumina, silicon oxide, magnesium oxide, zirconium oxide, and titanium oxide; and carbonic acid Carbonates such as calcium, magnesium carbonate and dolomite, sulfates such as calcium sulfate and barium sulfate, glass beads, boron nitride, and particulate fillers such as silicon carbide can be added. Further, two or more of these inorganic reinforcing materials and fillers can be used in combination.

The addition amount of the inorganic reinforcing material and the filler is preferably in the range of 5 to 50% by mass. Heat resistance is less than 50% by weight.
If the content is more than 10% by weight, moldability and toughness tend to decrease.

Further, within the range not impairing the effects of the present invention, lubricants such as silica and stearate, mold release agents, ultraviolet absorbers, coloring agents containing pigments such as carbon black, flame retardants such as halides and phosphorus compounds, etc. , Flame retardant aids, antioxidants,
Known additives such as an antistatic agent, a coupling agent, a foaming agent, a crosslinking agent, a crystal nucleating agent, and a heat stabilizer can be added. Further, as long as the effects of the present invention are not impaired, rubber-reinforced resins (butadiene-based copolymer, acrylic-based copolymer, silicon-based copolymer, silicon-acryl-based copolymer), AS resin, polystyrene resin, Polycarbonate resin, polyphenylene ether resin, other thermoplastic resin such as nylon resin and polyester elastomer for improving impact resistance, hydrolysis resistance, heat shock resistance, etc., MBS, butadiene type, acrylic type, silicon type, Various modifiers such as various rubber components such as silicone acrylics, olefin copolymers and nylon copolymers can be added.

As a method for producing a molded article obtained by integrating by heat welding according to the present invention, a polyester-based copolymer (a) is injection-molded, and a molded article (A) and other molded articles are produced. (B) is obtained. The joined surfaces of these molded products are melted by laser welding, vibration welding, ultrasonic welding, hot plate welding, etc., then the joined surfaces are brought into close contact, cooled, and joined to integrate the two molded products. To obtain one compact.

Other molded articles (B) are rubber-reinforced resins (butadiene-based copolymer, acrylic-based copolymer, silicon-based copolymer, silicone-acryl-based copolymer), AS resin,
The resin may be injection molded from a thermoplastic resin other than the polyester copolymer (a) such as a polystyrene resin, a polycarbonate resin, a polyphenylene ether resin, and a nylon resin.

Further, in the present invention, when the molded article (A) and another molded article (B) are overlapped and joined by the welding method, the molded article (A) and the molded article (A) may be used as long as the effects of the present invention are not impaired. A functional component such as a packing, a waterproof and moisture-permeable sheet, a film, and a plastic lens may be interposed between the joining surfaces of another molded product (B).

The molded article obtained by the present invention can be welded by using a polyester-based copolymer (a) with respect to heat welding represented by laser welding, vibration welding, ultrasonic welding, hot plate welding and the like. Strength is improved and processing conditions are greatly improved. As the molded body obtained in this way, automobile electric parts (various control units,
Ignition coil parts), motor parts, various sensor parts, connector parts, switch parts, relay parts, coil parts, transformer parts, lamp parts, etc., are widely used in the automotive field and the electric and electronic fields.

[0032]

The present invention will be described in detail with reference to the following examples.

<< Preparation of Polyester Copolymer >> PBT
As the copolymer, dimethyl isophthalic acid and 2,2
PBT copolymers (a-1) to (a-4) obtained by copolymerizing 6-naphthalenedicarboxylic acid with the copolymerization amounts shown in Table 1 and PBT polymers containing no copolymerized component (a-8: manufactured by Mitsubishi Rayon Co., Ltd.) Toughpet PBT N1300) was prepared.
In addition, the PBT copolymers (a-1) to (a-4) were copolymerized with each copolymer component according to a usual PBT production method. Each molecular weight was adjusted to be equivalent to N1300. As the PBN-based copolymer, a PBN copolymer (a-5) obtained by copolymerizing dimethylisophthalic acid at the copolymerization amounts shown in Table 1 and a PBN polymer (a-9) containing no copolymerized component were prepared. . In addition, the PBN copolymer (a-
5) was copolymerized with each copolymer component according to the usual method for producing a PBN polymer. Each molecular weight is N130
It was adjusted to be equivalent to 0.

Examples of the PET copolymer include a PET copolymer (a-6) obtained by copolymerizing 2,6-naphthalenedicarboxylic acid at the copolymerization amounts shown in Table 1 and a PET polymer containing no copolymerization component (a-6). a-10) was prepared. In addition, PET
The copolymer (a-6) was copolymerized with each copolymer component according to a usual method for producing a PET polymer. Each molecular weight was adjusted to be equivalent to N1300.

Examples of the PEN-based copolymer include a PEN copolymer (a-7) obtained by copolymerizing 2,7-naphthalenedicarboxylic acid at a copolymerization amount shown in Table 1, and a PEN polymer containing no copolymerization component (a). a-11) was prepared. In addition, PET
The copolymer (a-7) was copolymerized with each copolymer component according to a usual production method of a PEN polymer. Each molecular weight was adjusted to be equivalent to N1300.

The melting point of the polyester (co) polymer was measured by DSC (Seiko SSC5200).

Next, the polyester copolymers (a-1) to (a-7) and the polyester polymer (a) shown in Table 1
-8) to (a-11) show glass fibers (ECS03-T191 manufactured by Nippon Electric Glass), glass beads (glass beads GB731B manufactured by Toshiba), and glass flakes (REF-140 manufactured by Nippon Glass Fiber) as inorganic reinforcing materials. Each was mixed at the ratio shown in No. 2 and mixed and homogenized in a V-type blender for 5 minutes to obtain a resin composition. The obtained resin composition is φ
It is charged into a 30 mm vent-type twin-screw extruder. When using PBT and PBN (co) polymer, the cylinder temperature is 2
At 60 ° C., when PET and PEN (co) polymers were used, the pellets were prepared by extruding at a cylinder temperature of 285 ° C. to obtain resin compositions (b-1) to (b-15).

[Table 1]

[Table 2] << Evaluation of heat welding workability >> The heat welding workability was evaluated using these pellets. The laser welding method was adopted as the thermal welding method.

First, the resin compositions (b-1) to (b-1)
For 5), natural and black pellets were prepared respectively, and PBT and PBN (co) polymers were 120
℃ 4Hr, PET and PEN (co) polymer is 15
After the pellets were dried under the conditions of 0 ° C. × 4 hours, the cylinder temperature of the PBT and PBN (co) polymer was 260 ° C., and the cylinder temperature of the PET and PEN (co) polymer was 285 ° C. using an injection molding machine IS80 manufactured by Toshiba. , Mold temperature 80
At 100 ° C., a flat plate of 100 × 100 × 1 mmt was formed. Furthermore, a strip test piece of 100 × 10 × 1 mmt was prepared from the flat plate of 100 × 100 × 1 mmt, and used as a sample for laser welding evaluation. Next, as shown in FIG. 1, a semiconductor laser processing machine SDL-F manufactured by SDL Corporation
A black strip-shaped test piece (1) was placed on D25, and a natural-colored strip-shaped test piece (2) was placed and fixed so as to partially overlap the black strip-shaped test piece (1). Here, the laser beam (3) is applied from the side of the natural color strip test piece, and the position is adjusted so that the joint surface between the natural color and the black strip shape test piece becomes a focal point, and an output of 10 W and a laser Heat welding was performed under the conditions of a light irradiation speed of 2 mm / sec. Using a tensile tester, the molded body obtained in this manner was moved at a speed of 5 m.
m / min, tension between chucks 50 mm,
The tensile shear strength was calculated from the breaking load and the welding area.

Examples are shown in Table 3 and comparative examples are shown in Table 4.

[0040]

[Table 3]

[Table 4] Here, Comparative Example 1 for Examples 1 to 8 and Comparative Examples 2 to 3 and Example 1 for Examples 9 to 10
Comparative Example 4 for Example 1, Comparative Example 5 for Example 12, and Comparative Example 6 for Example 13.

[0041]

The laser welding provided by the present invention,
When performing the welding process, one or both of the molded bodies obtained by the thermal welding process typified by vibration welding, ultrasonic welding, hot plate welding, etc., have a melting point of 170 to 220 ° C. of a PBT-based composite. Incorporation, PBN-based copolymer having a melting point in the range of 190 to 240 ° C, PET-based copolymer having a melting point in the range of 200 to 250 ° C, or molded article comprising PEN-based copolymer having a melting point in the range of 210 to 260 ° C By doing so, a molded article having excellent welding strength can be obtained even under the same welding conditions. If molded products with the same welding strength can be obtained, joining with low melting energy is possible, and the range of welding conditions is widened, and the bonding surface = the degree of freedom in the shape of the molded products is widened. Therefore, there is an advantage that the service life of the welding apparatus can be extended. Examples of the molded body obtained in this manner include automotive electrical components (various control units, ignition coil components),
Motor parts, various sensor parts, connector parts, switch parts, relay parts, coil parts, transformer parts,
It is widely used in the automotive field, electric and electronic fields such as lamp parts.

[Brief description of the drawings]

FIG. 1 shows a laser welding method used in Examples.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Black strip-shaped test piece (molded product on the other side) 2 Natural-colored strip-shaped test piece (molded product on the laser light transmission side) 3 Laser light 4 Laser light moving direction (2 mm / sec)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) B29K 67:00 F term (Reference) 4F071 AA02B AA45 AA45B AA46 AA46B AA84 AF43 AF53 AG28 AH07 AH12 CD02 CD07 4F211 AA24E AA25E AA26E AD04 AD19 AG03 AH17 TA01 TD11 TN07 TN20 TN21 TN22 TN27 4J002 CF061 CF071 CF081 CF121 FD010 FD090 FD160 FD170 GN00 GQ00

Claims (2)

[Claims] 1. A polybutylene terephthale copolymer having a melting point in the range of 170 to 220 ° C., a melting point of 200 to 250.
A molded article (A) comprising at least one polyester-based copolymer (a) selected from a polyethylene terephthalate-based copolymer having a melting point in the range of 210 to 260 ° C. And a molded article (B) are integrated by welding to produce a molded article. 2. The molded article (B) according to claim 1, wherein the other molded article (B) is the same as the molded article (A).