JP3301816B2 - Polyester-based composite molded article and production method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite molded product excellent in airtightness and adhesion and a method for producing the same, and provides a composite molded product suitable for various equipment parts in the fields of automobiles and electric and electronic fields.

[0002]

2. Description of the Related Art Polyethylene terephthalate (PE) which is a crystalline thermoplastic resin
T resin), polybutylene terephthalate (PBT resin)
Are used as engineering plastics in a wide range of applications such as automobiles, electric and electronic parts, etc. because of their excellent mechanical properties, electrical properties, and other physical and chemical properties and good workability. However, in recent years, various kinds of characteristics are required for automobiles and electric / electronic parts, and a two-part molded part combining different materials has been developed as one of the characteristics imparting methods. Generally, as a method of integrally molding two kinds of materials, partially different characteristics are obtained by a dual molding method in which a dissimilar resin is secondarily molded on a primary molded article of the resin and the interface is fused and fixed. Although it is known to obtain a composite molded product having a composite molded product using a highly crystalline thermoplastic polyester for multiple molding, fusion at the interface between the resin on the primary side and the resin on the secondary side is insufficient. , Easy to peel off by external force, easy to warp, etc.
In many cases, the function as an integrally molded product is not satisfied. In order to compensate for the fusion strength at the interface between the two resins, the primary molded product must be provided with a mechanical structure that has a mechanical anchor effect, such as by providing undercuts or through holes, or by applying an adhesive to the primary molded product. As can be seen, the shape becomes complicated and the process becomes complicated, which is economically disadvantageous, and is also undesirable in terms of production efficiency. In particular, since polybutylene terephthalate, polypropylene terephthalate, or polyethylene terephthalate has high crystallinity, it is molded by a double molding method, and a composite molded product having a high fusion strength at the interface between resins can be economically produced by a simple method. It was very difficult to produce efficiently.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have developed a polyalkylene terephthalate resin which is an integrally molded product having excellent mechanical properties, chemical properties, thermal properties, etc. As a result of intensive studies to economically and efficiently obtain a composite molded product having a high fusion strength between resins by a simple multiple molding method without using any method, the present invention has been achieved. That is, the present invention provides airtightness and adhesion obtained by integrally molding a resin material (A) represented by the following (I) or (II) and a resin material (B) represented by the following (III) by a multiple molding method. This is a composite molded article having high properties and a method for producing the same. (I) 1 to 40 mol% of other dicarboxy mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms)
Introduced from acid compounds or low molecular weight dihydroxy compounds
A copolymer containing a comonomer unit (provided that
(II) A blend of the copolymer of (I) and 1-95% by weight of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) with respect to the total amount. (III) Polyalkylene Terephthalate (alkylene group having 2 to 4 carbon atoms) or other main component containing up to 40 mol%
Dicarboxylic acid compound or low molecular weight dihydroxy compound
(Excluding Liquid Crystalline Polyester) Containing Comonomer Units Introduced from the following, the constituent materials of the integrally molded article of the present invention and the molding method thereof will be described in detail.

Resin material (A) effective for the composite molded article of the present invention
(I) constituting one of the above is mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and 1 to 40
A copolymer containing at least one mol% of another comonomer unit, specifically, a poly (ethylene glycol) obtained by a polycondensation reaction between terephthalic acid or an ester-forming derivative thereof and an alkylene glycol having 2 to 4 carbon atoms or an ester-forming derivative thereof. It is mainly composed of alkylene terephthalate, and includes, for example, a copolymer containing polyethylene terephthalate, polypropylene terephthalate or polybutylene terephthalate as a main component, into which 1 to 40 mol% of another comonomer unit is introduced. The third component (comonomer) constituting such a copolymer includes isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid, and dodecanediacid. Examples of such known dicarboxylic acids and their alkyl, alkoxy or halogen-substituted products. These dicarboxylic acid compounds can also be used as a comonomer component in the form of a derivative capable of forming an ester, for example, a lower alcohol ester such as dimethyl ester, for polycondensation. Examples of the dihydroxy compound used as the third component for constituting the copolymer include ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, hydroquinone, resorcinol, Dihydroxyphenyl, naphthalene diol, dihydroxydiphenyl ether, cyclohexanediol, 2,2-bis (4
-Hydroxyphenyl) propane, relatively low molecular weight dihydroxy compounds such as diethoxylated bisphenol A, and alkyl, alkoxy or halogen substituted products thereof. These comonomer components may be introduced by mixing two or more kinds. In the present invention, the above-mentioned compound can be used as a comonomer component, and a thermoplastic polyester copolymer produced by polycondensation can be used alone or as a mixture of two or more kinds as the resin material (A) of the present invention. The resin material mainly composed of polyalkylene terephthalate constituting the integrally molded product in the present invention (A) is a material having characteristics as an original engineering plastic and having both excellent airtightness and excellent adhesiveness, The content of the copolymer component is in the range of 1 to 40 mol%,
Preferably it is in the range of 3-35 mol%. Further, such a resin material (A) is generally used as a primary molded product, and the secondary material (B) is molded and fused thereon, so that in order to obtain the fusion strength at the interface, the resin material is used in the secondary molding. Depending on the material (B), its surface (interface) needs to be temporarily melted, and its melting point also needs to be considered. Therefore, the melting point of the resin material (A) is desirably 250 ° C or lower, preferably 240 ° C or lower. If the melting point of the resin material (A) is too high,
In the secondary molding, it is necessary to further raise the molding resin temperature of the resin material (B), which tends to cause thermal decomposition and the like, and also impairs the moldability due to a decrease in viscosity, which is not preferable. On the other hand, if the melting point of the resin material (A) is too low, the primary material tends to be deformed during the secondary molding, which is not preferable. The melting point of the resin material (A) is adjusted according to the type of the polyalkylene terephthalate resin used, the type and amount of the copolymer component, and the like. Particularly preferred from this point of view are polyethylene terephthalate,
A copolymer mainly composed of polypropylene terephthalate or polybutylene terephthalate and having a copolymer component of 3 to 35 mol%. Further, as a resin material (A) effective for the composite molded article of the present invention, poly (alkylene terephthalate (alkylene group having 2 to 4 carbon atoms) is added to the copolymer (I) in an amount of 1 to 95% by weight based on the total amount. Mixed blends (II) are also mentioned. The mixing amount of polybutylene terephthalate, polypropylene terephthalate or polyethylene terephthalate to be blended is 95% by weight or less, preferably 90% by weight, based on the total amount of (II) from the viewpoint of imparting airtightness and fusibility of the molded article and melting point of the mixture. % By weight or less is preferred.

Further, a resin material constituting the molded article of the present invention
As (A), a small amount of another thermoplastic resin may be supplemented in addition to the resin represented by (I) or (II) in order to impart desired properties. As such an auxiliary thermoplastic resin, for example, a polyolefin-based polymer,
Polyamide-based polymer, polycarbonate-based polymer, polyarylate-based polymer, polyester polymer other than the main component (for example, completely aromatic polyester), styrene-based polymer (for example, AS or ABS resin), polyphenylene oxide-based polymer, Acrylate-based polymers, polyacetals, polysulfones, polyethersulfones, polyetherimides, polyetherketones, polyarylenesulfide-based polymers, fluororesins, olefin-based thermoplastic elastomers (eg, EPDM or ionomer), styrene-based thermoplastic elastomers (eg, SBS or SEB
S), a urethane-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a polyether-based thermoplastic elastomer, or a modified product thereof, and the like. Two or more kinds of these thermoplastic resins are mixed. You can also use
As described above, it is necessary to consider the rigidity, melting point, and the like of the compound even when such other thermoplastic resin is compounded supplementarily. The resin material (A) constituting the molded article of the present invention may contain an inorganic filler. Such a filler is preferably blended in order to obtain excellent properties such as mechanical strength, heat resistance, dimensional stability, and electrical properties, and is particularly effective for increasing rigidity. For this purpose, a fibrous, powdery or plate-like filler is used depending on the purpose.
As the fibrous filler, glass fiber, asbestos fiber,
Inorganic substances such as carbon fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and metal fibrous materials such as stainless steel, aluminum, titanium, copper, and brass Fibrous substances. Particularly typical fibrous fillers are glass fibers. In addition, a high melting point organic fibrous substance such as polyamide, fluororesin, and acrylic resin can also be used. On the other hand, as powdery fillers, carbon black, silica, quartz powder, glass beads, glass powder, calcium silicate, aluminum silicate, kaolin, talc,
Clay, diatomaceous earth, silicates such as wollastonite, oxides of metals such as iron oxide, titanium oxide and alumina, carbonates of metals such as calcium carbonate and magnesium carbonate, metals such as calcium sulfate and barium sulfate Sulfates, other silicon carbide, silicon nitride, boron nitride, various metal powders, and the like. Examples of the plate-like filler include mica, glass flake, various metal foils, and the like. These inorganic fillers can be used alone or in combination of two or more. The combined use of a fibrous filler, particularly a glass fiber or a carbon fiber, and a granular or plate-like filler is a preferable combination, particularly in terms of having both mechanical strength, dimensional accuracy, electrical properties and the like. The amount of the inorganic filler added is 40% by weight or less based on the total amount of the resin material (A). If it is more than this, the moldability and toughness are impaired, which is not preferable. Particularly preferably, it is at most 30% by weight.

[0006] Next, (III) constituting the resin material (B) for forming the other part of the composite molded article is mainly a polyester resin such as polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, or a resin containing these as a main component. a polymer obtained by introducing 40 mol% or less of other comonomer units thereto. As the third component (comonomer) constituting such a copolymer, the same dicarboxylic acid compound as described in the resin material (A),
A dihydroxy compound may be used, and the comonomer component may be a mixture of two or more components. In the present invention, the above-described compound can be used as a comonomer component, and a thermoplastic polyester copolymer produced by polycondensation can be used alone or as a mixture of two or more kinds as the resin material (B) of the present invention. Since the resin material (B) constituting the integrally molded article in the present invention is a material originally having properties as an engineering plastic, the content of the copolymer component is at most 40 mol% or less, preferably 35 mol% or less.
Mol% or less. If this is expressed in terms of flexural modulus, it is desirably at least 15000 kgf / cm ² or more, preferably 18000 kgf / cm ² or more. In addition, as the resin material (B) constituting the molded article of the present invention, a thermoplastic resin and / or various fillers may be blended in addition to the resin represented by the above (III). Examples of the thermoplastic resin and filler to be compounded are the same as those used in the resin material (A).

The resin material (A) used in the present invention
And (B) are known substances other than the above, which are generally added to a thermoplastic resin in order to impart desired properties to one or both of them, that is, various kinds of substances such as antioxidants and ultraviolet absorbers. It is of course possible to incorporate stabilizers, antistatic agents, flame retardants, flame retardant aids, coloring agents such as dyes and pigments, lubricants, plasticizers and crystallization accelerators, crystal nucleating agents, mold release agents, etc. is there.

[0008] The composite molded article of the present invention comprises the above (A) and (B) 2
It is molded by a so-called multiple molding method using various kinds of resin materials. As a molding method, injection molding, compression molding and other molding methods are applied, but injection molding is generally preferred.
Either resin material (A) or (B) is molded in advance to form a primary molded product, and then another resin material is molded, fused and integrated, and the shape and structure of the molded product or purpose Any of the primary side molded products may be used depending on the application.However, it is generally better to perform primary molding with the resin material (A) and then secondary mold the resin material (B) when the molded product loses its shape or during molding or during molding. It is preferable in order to prevent deformation later. In this case, in order to perform strong fusion, in the secondary molding, the resin material (B)
It is necessary that the surface layer (interface) of the primary molded article is melted by the resin temperature of the primary molded article. Therefore, the resin temperature in the secondary molding must be at least a melting point of the resin material (A) of the primary molded article. Yes, it is preferable to perform the secondary molding by raising the resin temperature of the secondary material at the time of contact in the secondary molding by 10 to 120 ° C., preferably 30 to 100 ° C. above the melting point of the primary material. However, if the resin temperature of the secondary material is too high, the secondary material may be decomposed and deteriorated.To avoid this, it is not preferable that the resin material (A) of the primary molded product has a melting point that is too high. As shown, the melting point of the primary material is 250 ° C
The temperature is preferably 240 ° C. or lower, which is controlled by the copolymerization component of the polyalkylene terephthalate-based resin of the resin material (A) constituting the primary molded product and its introduction amount, auxiliary components and its blending amount, etc. However, since such adjustment also affects the rigidity of the material itself, the resin material configuration is selected depending on the balance.

[0009]

EXAMPLES In order to find the best combination of polyesters, the present inventors have selected polyesters with different properties,
An experiment was conducted on the adhesion strength exhibited by these combinations. Next, an experimental example will be described. First, using resin material (A), 80mm square, 2mm thick as primary molded product
Was molded. Next, this flat plate is mounted in a mold cavity of 80 mm square and 4 mm thick, and the resin material (B) is used as a secondary material and the resin temperature is changed to perform secondary molding to form a flat composite molded product. Then, the peel strength at the interface was measured. The peel strength was measured by cutting a composite molded product to a width of 10 mm, forcibly peeling off the joint interface at one end by a fixed length with a knife, setting each of them on a fixture of a tensile tester, pulling and peeling. The maximum load that caused the pressure was defined as the peel strength. The inventor also conducted an experiment on the airtightness exhibited by the combination of each polyester. Next, an experimental example will be described. The inspection method is as follows: After exposing a flat composite molded article to an atmosphere of 130 ° C for 60 minutes, immersing it in water of 0 ° C for 60 minutes, taking it out of the water and leaving it at room temperature for 15 minutes, a heating and cooling cycle Repeat 50 times, then immerse in highly permeable ink,
After the ink had dried, the adhesive surface was broken and the state of penetration of the ink was visually observed.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto. Example 1 DMI (dimethyl isophthalate) was used as the resin material (A).
Is modified by copolymerizing about 12.5 mol% of
Primary molding of BT (melting point 205 ° C) (A-1), secondary molding using PBT resin (melting point 225 ° C) (B-1) as a secondary material and changing the resin temperature, flat composite molding The product was molded and its peel strength and airtightness were evaluated. Table 1 shows the results.

Example 2 As a resin material (A), DMI-modified PBT (melting point 205 ° C.)
(A-1) is first molded, and the same DMI-modified PBT (A-1) as the resin material (B) is secondarily molded by changing its resin temperature,
The same evaluation as in Example 1 was performed. Table 1 shows the results.

Example 3 DMI modified PBT modified by copolymerizing about 5 mol% of DMI as resin material (A) (melting point: 215 ° C.) (A-2)
Is primarily molded, and as the resin material (B), PET resin (B-2)
Was subjected to secondary molding while changing the resin temperature, and the same evaluation as in Example 1 was performed. Table 1 shows the results.

Example 4 About 17.5 mol% of ethylene glycol as the resin material (A)
Modified PBT modified by copolymerization (melting point 205
℃) (A-3) as primary resin and PBT resin as resin material (B)
(B-1) was subjected to secondary molding by changing the resin temperature, and the same evaluation as in Example 1 was performed. Table 1 shows the results.

Comparative Example 1 PBT resin (melting point: 257 ° C.) (B-1) was first molded, and then the same PBT resin (B-1) was secondarily molded by changing the resin temperature. An evaluation was performed. Table 1 shows the results.

Comparative Example 2 PET resin (melting point: 257 ° C.) (B-2) was first molded, and then the same PET resin (B-2) was secondarily molded by changing its resin temperature. An evaluation was performed. Table 1 shows the results.

[0016]

[Table 1]

Example 5 As a resin material (A), DMI-modified PBT (melting point 205 ° C.)
(A-1) A composition (a-1) composed of (70% by weight) and glass fiber (30% by weight), and a PBT resin (melting point 2) as a resin material (B).
A composite molded article was molded using the composition (b-1) composed of (B-2) (70% by weight) and glass fiber (30% by weight) and evaluated in the same manner as in Example 1. . Table 2 shows the results.

Example 6 A composite molded article was molded using the same composition (a-1) as in Example 5 as the resin material (A) and the resin material (B), and the same evaluation was performed. Table 2 shows the results.

Example 7 As a resin material (A), DMI-modified PBT (melting point: 215 ° C.) (A
-2) Composition (a-2) consisting of (70% by weight) and glass fiber (30% by weight), and PET resin (melting point 257) as resin material (B)
° C) (B-2) A composite molded article was molded using the composition (b-2) consisting of (70% by weight) and glass fiber (30% by weight), and was evaluated in the same manner as in Example 5. . Table 2 shows the results.

Example 8 As a resin material (A), a composition (a-3) comprising ethylene glycol-modified PBT (melting point: 205 ° C.) (A-3) (70% by weight) and glass fiber (30% by weight), resin PB as material (B)
A composite molded article was formed using a composition (b-1) composed of T resin (melting point: 225 ° C.) (B-1) (70% by weight) and glass fiber (30% by weight). An evaluation was performed. Table 2 shows the results
Shown in

Example 9 As a resin material (A), DMI-modified PBT (melting point 205 ° C.) (A
-1) and a composition (b-1) consisting of PBT resin (melting point: 225 ° C.) (B-1) (70% by weight) and glass fiber (30% by weight) as the resin material (B) Then, a composite molded article was formed, and the same evaluation as in Example 5 was performed. Table 2 shows the results.

Example 10 As a resin material (A), DMI-modified PBT (melting point 205 ° C.) (A
-1) (30% by weight), PBT resin (melting point 225 ° C) (B-1)
(B-3) (b-3) is primarily molded from a composition (40% by weight) and glass fiber (30% by weight) (melting point of the composition: 215 ° C)
Using PBT resin (melting point 225 ° C) (B-1) (70% by weight) and glass fiber (30% by weight) composition (b-1) as (B), molding a composite molded article The same evaluation as in Example 5 was performed. Table 2 shows the results.

Comparative Example 3 A composition (b-1) composed of PBT resin (melting point: 225 ° C.) (B-1) (70% by weight) and glass fiber (30% by weight) was first molded,
Subsequently, the same composition (b-1) was subjected to secondary molding, and the same evaluation as in Example 5 was performed. Table 2 shows the results.

Comparative Example 4 A composition (b-2) composed of PET resin (melting point: 257 ° C.) (B-2) (70% by weight) and glass fiber (30% by weight) was first molded,
Subsequently, the same composition (b-2) was subjected to secondary molding, and the same evaluation as in Example 5 was performed. Table 2 shows the results.

Comparative Example 5 PBT resin (melting point: 225 ° C.) (B-1) was first molded, and then a composition (b) comprising PBT resin (B-1) (70% by weight) and glass fiber (30% by weight) -1) was subjected to secondary molding, and the same evaluations as in Example 5 were performed. Table 2 shows the results.

[0026]

[Table 2]

[0027]

According to the present invention, when a PBT resin is used in producing a composite molded product by the multiple molding method, practical resin adhesion strength and airtightness are not expected at a resin temperature of 260 ° C. or less during secondary molding. Further, when a PET resin is used, even at a temperature of the secondary resin material of 290 ° C., sufficient adhesiveness and airtightness between the resins are not obtained. However, according to the present invention, the use of the specific resin materials (A) and (B) as described above provides an anchor shape under normal molding resin temperature conditions where there is no risk of thermal decomposition of the resin, or provides an adhesive. Without using it, it is possible to easily and economically efficiently produce a composite molded article having a strong interfacial adhesion strength and airtightness that cannot be obtained by the conventional double molding method.

Moreover, the composite molded article of the present invention has excellent thermal stability, physical properties, mechanical properties, etc. of polyester engineering plastics, and especially has a chemical stability to chemicals, solvents, lubricants, detergents, etc. It is suitable for many uses in the automotive field and electric / electronic field where such characteristics are required as a product.

Claims (6)

(57) [Claims] An airtightness obtained by integrally molding a resin material (A) represented by the following (I) or (II) and a resin material (B) represented by the following (III) by a multiple molding method. Composite molded product with high adhesion. (I) 1 to 40 mol% of other dicarboxy mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms)
Introduced from acid compounds or low molecular weight dihydroxy compounds
A copolymer containing a comonomer unit (provided that
(II) A blend of the copolymer of (I) and 1-95% by weight of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) with respect to the total amount. (III) Polyalkylene Terephthalate (alkylene group having 2 to 4 carbon atoms) or other main component containing up to 40 mol%
Dicarboxylic acid compound or low molecular weight dihydroxy compound
Polymer containing comonomer unit introduced from (excluding liquid crystalline polyester) 2. The composite molded article according to claim 1, wherein the resin material (A) has a melting point of 250 ° C. or less. 3. The resin material (A) comprises an inorganic filler and a resin material.
3. The composite molded article according to claim 1, which is a composition containing 1 to 40% by weight based on the total amount of (A). 4. The resin material (B) comprises an inorganic filler and a resin material.
The composite molded article according to any one of claims 1 to 3, which is a composition containing 1 to 40% by weight based on the total amount of (B). 5. A resin article (A) represented by the following (I) or (II) is injection-molded to form a primary molded product, and the resin material (B) represented by the following (III) is further added to the primary molded article. ), By injection molding and fusing them together to form a composite molded article having excellent airtightness and adhesion. (I) 1 to 40 mol% of other dicarboxy mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms)
Introduced from acid compounds or low molecular weight dihydroxy compounds
A copolymer containing a comonomer unit (provided that
(II) A blend of the copolymer of (I) and 1-95% by weight of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) with respect to the total amount. (III) Polyalkylene Terephthalate (alkylene group having 2 to 4 carbon atoms) or other main component containing up to 40 mol%
Dicarboxylic acid compound or low molecular weight dihydroxy compound
Polymer containing comonomer unit introduced from (excluding liquid crystalline polyester) 6. The method according to claim 5, wherein the resin temperature at the time of secondary injection molding of the resin material (B) is higher than the melting point of the resin material (A) by 10 ° C. or more.