JPH07173298A - Polyester conjugate molding and its production - Google Patents

Abstract

PURPOSE:To provide a polyester conjugate molding excellent in flame retardancy, airtightness and tight adhesion by the multiple molding of a resin material comprising, e.g. a specified copolymer consisting mainly of a polyalkylene terephthalate and a resin material comprising a mixture of the copolymer and a flame retardant. CONSTITUTION:A resin material comprising a copolymer (I) composed mainly of a polyalkylene terephthalate (of 2-4C alkylene) and containing 1-40mol% other comonomer unit, or a blend (II) of the copolymer I with the polyalkylene terephthalate in an amount of 1-95wt.% based on the total weight of the blend is integrally molded by the multiple molding method with a flame-retardant resin material (III) consisting of 40-97wt.% copolymer I, 3-25wt.% halogenated flame retardant and 0-15wt.% antimony compound. It is desirable that the melting point of the resin I or II is 250 deg.C or lower. The resin material I or II may contain 1-40wt.% inorganic filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite molded article having excellent flame retardancy, airtightness and adhesion, and a method for producing the same, which is suitable for various machine parts in the automobile and electric / electronic fields. It is to provide goods.

[0002]

2. Description of the Related Art Polybutylene terephthalate (PBT resin), polyethylene terephthalate (PET resin) and the like, which are crystalline resins, have mechanical properties, electrical properties, and other physical and chemical properties. It is used as a engineering plastic in a wide range of applications such as automobiles and electric / electronic parts due to its excellent heat resistance and processability. In recent years, in many cases, these electric / electronic and automobile parts are required to have flame retardancy and at the same time various types of advanced characteristics. On the other hand, the flame-retardant polyalkylene terephthalate is made flame-retardant by adding a flame-retardant agent, so that the physical property tends to be inferior to that of the non-flame-retardant agent due to the flame-retardant agent. Various additives are added to improve the deterioration of physical properties,
These may also deteriorate physical properties other than the intended physical properties, and when conflicting requirements are made for one component,
In some cases, one type of material cannot be used. As one method for solving such a case, a composite molded part has been developed in which materials that are suitable for different requirements are combined and integrated. Generally, as a method for integrally molding two kinds of materials, a double molding method in which a resin of a different material is secondarily molded on a primary-side molded product of the resin and the interface is fusion-bonded is used to obtain partially different characteristics. It is known to obtain a composite molded article having. However, in a composite molded product using a highly crystalline thermoplastic polyester for multiple molding, the fusion between the primary side resin and the secondary side resin is insufficient, and it easily peels off due to external force, and also warps In many cases, the function as an integrally molded product is not satisfied in use. For the purpose of supplementing the fusion strength at the interface between both resins, we have found some ideas such as providing a shape structure with a mechanical anchor effect such as providing an undercut or through hole in the primary molded product, or applying an adhesive to the primary molded product. However, the shape is complicated, and the process is complicated, which is economically disadvantageous and is not desirable in terms of production efficiency. In particular, polybutylene terephthalate, polypropylene terephthalate, or polyethylene terephthalate have high crystallinity, so they are molded by a double molding method, and a composite molded product with a high fusion strength at the interface between resins can be efficiently manufactured by a simple method. It was very difficult to produce well.

[0003]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made an integrally molded product having excellent mechanical properties, chemical properties, thermal properties, etc. of a polyalkylene terephthalate resin, and in particular providing an anchor shape or an adhesive. The present invention has been achieved as a result of earnestly studying to obtain a flame-retardant composite molded article having high fusion bonding strength between resins economically and efficiently by a simple multiplex molding method without using the above. That is, the present invention is formed by integrally molding a resin material (A) represented by the following (I) or (II) and a flame retardant resin material (B) represented by the following (III) by a multiple molding method. A flame-retardant composite molded article excellent in airtightness and adhesion and a method for producing the same. (I) Copolymer mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and containing 1 to 40 mol% of other comonomer unit (II) Polyalkylene terephthalate added to the copolymer of (I) Blend containing 1 to 95% by weight of (alkylene group having 2 to 4 carbon atoms) based on the total amount (III) (a) Mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and 40 mol% or less A flame-retardant resin material consisting of 40 to 97% by weight of a copolymer containing another comonomer unit (b) 3 to 25% by weight of a halogen-based flame retardant (C) 0 to 15% by weight of an antimony compound. The constituent materials of the integrally molded article and the molding method thereof will be described in detail.

Resin material (A) effective for the composite molded article of the present invention
(I), which constitutes one of the above, is mainly composed of polyalkylene terephthalate (having 2 to 4 carbon atoms in the alkylene group) and 1 to 40.
It is a copolymer containing mol% of other comonomer units, and specifically, it is obtained by polycondensation reaction of terephthalic acid or its ester-forming derivative with alkylene glycol having 2 to 4 carbon atoms or its ester-forming derivative. It is mainly composed of alkylene terephthalate, and examples thereof include copolymers containing polyethylene terephthalate, polypropylene terephthalate or polybutylene terephthalate as a main component, and 1 to 40 mol% of other comonomer units introduced therein. Examples of the third component (comonomer) constituting the copolymer include isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenyletherdicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexanedicarboxylic acid, adipic acid, sebacic acid and dodecanedioic acid. Such known dicarboxylic acids and their alkyl, alkoxy or halogen-substituted products can be used. Further, these dicarboxylic acid compounds can also be used as a comonomer component by being used for polycondensation in the form of a derivative capable of forming an ester, for example, a lower alcohol ester such as dimethyl ester. Further, examples of the dihydroxy compound used as the third component for forming the copolymer include ethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, hydroquinone, resorcin, Dihydroxyphenyl, naphthalenediol, dihydroxydiphenyl ether, cyclohexanediol, 2,2-bis (4
-Hydroxyphenyl) propane, a dihydroxy compound having a relatively low molecular weight such as diethoxylated bisphenol A, and alkyl, alkoxy or halogen substitution products thereof. Two or more kinds of these comonomer components may be mixed and introduced. In the present invention, a thermoplastic polyester copolymer produced by polycondensation can be used alone or in combination of two or more as the resin material (A) of the present invention, using the above compound as a comonomer component. Since the resin material mainly composed of polyalkylene terephthalate (A) constituting the integrally molded product in the present invention is a material having properties as an original engineering plastic and having excellent properties of airtightness and adhesion, The content of the copolymerization component is in the range of 1 to 40 mol%,
It is preferably in the range of 3 to 35 mol%.

Further, such a resin material (A) is generally used as a primary molded product, and a secondary material (B) is molded and fused thereon. Therefore, in order to obtain the fusion strength of the interface, the secondary material (A) is used. In molding, the surface (interface) of the resin material (B) needs to be temporarily melted, and its melting point also needs to be considered. Therefore, the melting point of the resin material (A) is 250 ° C. or lower, preferably 240 ° C. or lower. If the melting point of the resin material (A) is too high, it is necessary to raise the molding resin temperature of the resin material (B) in the secondary molding, which easily causes thermal decomposition, etc. Harm and unfavorable. If the melting point of the resin material (A) is too low, the primary material is likely to be deformed during the secondary molding, which is not preferable. The melting point of the resin material (A) is adjusted depending on the type of polyalkylene terephthalate resin used therein, the type and amount of the copolymerization component, and the like. From this viewpoint, polyethylene terephthalate, polypropylene terephthalate, or polybutylene terephthalate is mainly used, and 3 is particularly preferable.
It is a copolymer having a copolymer component of ˜35 mol%. As the resin material (A) effective for the composite molded article of the present invention, polyalkylene terephthalate (having 2 to 4 carbon atoms in the alkylene group) is added to the copolymer of (I) in an amount of 1 to 95% by weight based on the total amount. A mixed blend (II) is also included. The blending amount of the polybutylene terephthalate, polypropylene terephthalate or polyethylene terephthalate to be blended is 95% by weight or less, preferably 90% by weight or less with respect to the total amount of (II) from the viewpoint of imparting airtightness and fusion property of the molded product and melting point of the mixture. It is preferably less than or equal to weight%.

Further, a resin material constituting the molded article of the present invention
As (A), a small amount of other thermoplastic resin may be supplementarily added in addition to the resin represented by (I) or (II) above in order to impart desired properties. Examples of such an auxiliary thermoplastic resin include a polyolefin-based polymer,
Polyamide-based polymer, polycarbonate-based polymer, polyarylate-based polymer, polyester-based polymer other than the main component (for example, fully aromatic polyester), styrene-based polymer (for example, AS or ABS resin), polyphenylene oxide-based polymer, Acrylate polymers, polyacetals, polysulfones, polyether sulfones, polyetherimides, polyether ketones, polyarylene sulfide polymers, fluororesins, olefinic thermoplastic elastomers (eg EPDM or ionomer), styrene thermoplastic elastomers (eg SBS or SEB
S), urethane-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, polyether-based thermoplastic elastomer, or modified products thereof, and the like, and these thermoplastic resins are mixed in two or more kinds. Can be used as
Also in the case of supplementarily blending such other thermoplastic resin, it is necessary to consider the rigidity, melting point and the like of the blend as described above.

A resin material constituting the molded article of the present invention
An inorganic filler can be added to (A). Such fillers are preferably blended in order to obtain excellent properties such as mechanical strength, heat resistance, dimensional stability, and electrical properties, and are particularly effective for increasing rigidity. A fibrous, powdery or plate-like filler is used for this purpose. As the fibrous filler, glass fiber, asbestos fiber, carbon fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, further stainless steel, aluminum, titanium, Inorganic fibrous substances such as metallic fibrous substances such as copper and brass can be used. A particularly representative fibrous filler is glass fiber. In addition, high melting point organic fibrous substances such as polyamide, fluororesin and acrylic resin can also be used. On the other hand, as the particulate filler, carbon black, silica, quartz powder, glass beads, glass powder,
Silicates such as calcium silicate, aluminum silicate, kaolin, talc, clay, diatomaceous earth, wollastonite,
Oxides of metals such as iron oxide, titanium oxide and alumina, carbonates of metals such as calcium carbonate and magnesium carbonate,
Examples thereof include metal sulfates such as calcium sulfate and barium sulfate, as well as silicon carbide, silicon nitride, boron nitride and various metal powders. Examples of the plate-like filler include mica, glass flakes, 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 glass fiber or carbon fiber, with a granular or plate-like filler is a preferable combination particularly in terms of having both mechanical strength, dimensional accuracy, and electrical properties. The addition amount of the inorganic filler is 40% by weight or less based on the total amount of the resin material (A). If it is more than this range, the formability and toughness are impaired, which is not preferable. It is particularly preferably 30% by weight or less.

The resin material constituting the molded article of the present invention
A halogen-based flame retardant can be added to (A).
The flame retardant may be any organic halogen compound which is generally used as a flame retardant for thermoplastic polyesters to obtain flame retardancy, and may be halogenated phenyl, halogenated diphenyl ether, halogenated aromatic bisimide compound, halogenated compound. Examples thereof include aromatic epoxy compounds, low molecular weight organic halogen compounds of bisphenol A, halogenated polycarbonates and halogenated polystyrenes. Here, halogen is preferably bromine in general. The flame retardants may be used alone or in combination of two or more. Using any of the above flame retardants, it is possible to achieve the object of the present invention, particularly halogenated aromatic bisimide compound, halogenated aromatic epoxy compound, halogenated polycarbonate, halogenated benzyl acrylate, halogenated polystyrene Use is preferred. The amount of the flame retardant added can be arbitrarily added according to the required flame retardancy level, but from the viewpoint of mechanical properties of the molded product, moldability, thermal stability and cost, the resin material (A) relative to the total amount. 0 to
15% by weight is preferred and 3-10% by weight is particularly preferred. Furthermore, an inorganic flame retardant aid may be added to the resin material (A) of the present invention to help the effect of the flame retardant. Typical examples thereof include antimony trioxide, antimony tetroxide, antimony pentoxide, sodium antimonate and the like. The amount of the flame retardant aid can be arbitrarily added according to the required flame retardancy, but from the viewpoint of mechanical properties of the molded product, moldability, thermal stability and cost, it can be added to the total amount of the resin material (A). 0 to 10% by weight is preferable, and 2 to 7% by weight is particularly preferable.

Next, (III) which constitutes the flame-retardant resin material (B) for forming the other part of the composite molded article includes (a) mainly polyester resins such as polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate, Alternatively, a copolymer containing these as main components and 40 mol% or less of another comonomer unit, (b) 3 to 25% by weight of a halogen-based flame retardant, and (c) an antimony-based compound 0
It is a flame-retardant resin material consisting of ~ 15% by weight. As the third component (comonomer) constituting the copolymer (a),
The same dicarboxylic acid compound and dihydroxy compound as those described for the resin material (A) can be mentioned, and two or more kinds of comonomer components may be mixed and introduced. In the present invention, a compound as described above is used as a comonomer component,
The thermoplastic polyester copolymers produced by polycondensation can be used alone or in combination of two or more as the resin material (a) of the present invention. Since the flame-retardant resin material (B) that constitutes the integrally molded product in the present invention is a material originally having a property as an engineering plastic,
The content of the copolymer (a) component is at most 40 mol%, preferably 35 mol% or less.

Further, as the flame retardant (b) blended with the flame retardant resin material (B), a halogen flame retardant can be used. Such flame retardant (b) is generally a thermoplastic polyester flame retardant (b)
It is possible to use an organic halogen compound used as a material, but the flame-retardant ability and the flame-retardant resin material (B) are 2
It is preferable to use the flame retardant (b), which has good heat resistance, because it is used for double molding and is molded at a high temperature. Such a flame retardant (b) may be a halogenated bisimide compound (alkylenebistetrabromophthalimide or arylenebistetrabromophthalimide is preferable as this compound), a brominated epoxy resin having a molecular weight of 10,000 or more, or polypentabromo Benzyl acrylate, or polydibromostyrene and / or polytribromostyrene are preferred. The amount of the flame retardant added can be arbitrarily added according to the required flame retardance level, but from the viewpoint of cost, mechanical properties, and moldability, the resin material (B)
It is preferably from 3 to 25% by weight, particularly preferably from 3 to 10% by weight, based on the total amount.

Further, the flame-retardant resin material (B) of the present invention contains
Inorganic flame retardant aids can be added to help the flame retardant effect. Typical examples thereof include antimony trioxide, antimony tetraoxide, antimony pentoxide, sodium antimonate and the like. The amount of the flame retardant aid can be arbitrarily added according to the required flame retardancy, but from the viewpoint of mechanical properties of the molded product, moldability, thermal stability and cost, the resin material
(B) The total amount is preferably 0 to 15% by weight, particularly preferably 2 to 7% by weight.

As the flame-retardant 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 the filler to be blended are the same as those used in the resin material (A).

The resin material (A) used in the present invention
And (B) is a known substance other than the above, which is generally added to the thermoplastic resin in order to impart desired properties to either or both of them, that is, various kinds of antioxidants, ultraviolet absorbers and the like. It is of course possible to add stabilizers, antistatic agents, colorants such as dyes and pigments, lubricants, plasticizers and crystallization accelerators, crystal nucleating agents, release agents and the like.

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 the molding method, injection molding, compression molding and other molding methods are applied, but injection molding is generally preferred.
Either the resin material (A) or (B) is molded in advance to form a primary molded product, and then another resin material is molded and then fused and integrated to form the shape structure or purpose of the molded product. Depending on the intended use, either may be used as the primary side molded product, but generally it is better to perform primary molding with resin material (A) and then secondary molding with resin material (B) when the molded product is deformed or when molding or molding. It is preferable in preventing deformation later.

In this case, the surface layer (interface) of the primary molded article must be melted by the resin temperature of the resin material (B) in the secondary molding in order to firmly bond the two.
Therefore, the resin temperature in the secondary molding must be at least the melting point of the resin material (A) of the primary molded product, and the resin temperature of the secondary material at the time of contact in the secondary molding is 10% below the melting point of the primary material. It is preferable to carry out the secondary molding by raising the temperature by 120 to 120 ° C., preferably 30 to 100 ° C. However, if the resin temperature of the secondary material is too high, it may cause decomposition and deterioration of the secondary material.To avoid this, the resin material of the primary molded product
It is not preferable that the melting point of (A) is too high, and generally, as described above, the melting point of the primary material is 250 ° C. or lower, preferably 24
The temperature is 0 ° C. or less, which can be adjusted by the copolymerization component of the polyalkylene terephthalate resin of the resin material (A) constituting the primary molded product and its introduction amount, auxiliary components and its compounding amount, etc. Since such adjustment also affects the rigidity of the material itself, the resin material configuration is selected depending on the trade-off.

[0016]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. Examples 1 to 20, Comparative Examples 1 to 5 Polyalkylene terephthalate (a) and / or halogen-based flame retardant (b), and optionally inorganic filler (d) were added and mixed in the proportions shown in Table 1, and the extruder was used. Then, a pelletized composition was obtained to obtain a resin material (A). Further, the halogen-based flame retardant (b), the antimony compound (c), and optionally the inorganic filler (d) were added to the polyalkylene terephthalate (a) in the proportions shown in Table 2, mixed and pelletized by an extruder. A resin composition (B) was obtained. Table 3 shows the composition and physical properties of the polyalkylene terephthalate resin used. Next, using the resin materials (A) and (B), composite molded articles were prepared in the combinations shown in Tables 4 and 5, and the adhesion strength was evaluated. The results are shown in Tables 4 and 5.

The adhesion strength was evaluated as follows. [Adhesion Strength Evaluation Method] First, using the resin material (A), a half of the ASTM No. 1 dumbbell shown in FIG. Next, this molded piece is
Attached to the die of No. 1 dumbbell, using resin material (B) as the secondary material, changing the resin temperature to perform secondary molding, and then, as shown in Fig. 1 (b).
A dumbbell-shaped composite molded article having a joint portion at the central portion shown in Fig. 3 was obtained. The adhesion strength of the composite molded product was measured using a tensile tester.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

[Table 5]

[0023]

When a PBT or PET resin is used as the primary material for producing a composite molded article by the multiple molding method, the adhesion strength cannot be expected if the resin temperature during the secondary molding is 280 ° C. or lower. Further, depending on the flame retardant on the secondary side, if the molding temperature is raised, deterioration may occur and molding may not be possible. However, according to the present invention, by using the specific resin material (A), (B) as described above, to provide an anchor shape under normal molding temperature conditions,
A composite molded article having strong interfacial adhesion strength and airtightness, which cannot be obtained by the conventional double molding method, can be simply and economically and efficiently produced without using an adhesive. Moreover, the composite molded article of the present invention has excellent thermal stability, physical properties, mechanical properties, and the like of polyester-based engineering plastics, and particularly has chemical stability against chemicals, solvents, lubricants, detergents, and the like. As a result, it is suitable for many applications in the automobile field and electric / electronic fields where such characteristics are required.

[Brief description of drawings]

FIG. 1 is a diagram showing a molded product for measuring adhesion strength used in Examples, (a) is a primary molded product, and (b) is a dumbbell having a bonded portion at the center where a secondary molded product is bonded. Shaped composite molded article.

[Explanation of symbols]

 1 Primary molded product 2 Secondary molded product 3 Junction 4 Gate

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Claims (11)

[Claims] 1. A resin material (A) represented by the following (I) or (II) and a flame-retardant resin material (B) represented by the following (III) are integrally molded by a multiple molding method. Flame-retardant composite molded product with excellent airtightness and adhesion. (I) Copolymer mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and containing 1 to 40 mol% of other comonomer unit (II) Polyalkylene terephthalate added to the copolymer of (I) Blend containing 1 to 95% by weight of (alkylene group having 2 to 4 carbon atoms) based on the total amount (III) (a) Mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and 40 mol% or less Copolymer containing other comonomer units 40-97% by weight (b) Halogen-based flame retardant 3-25% by weight (C) Antimony compound 0-15% by weight flame-retardant resin material 2. The resin represented by (I) or (II) contained in the resin material (A) has a melting point of 250 ° C. or lower.
The described composite molded article. 3. The composite molded article according to claim 1, wherein the resin material (A) is a composition containing an inorganic filler in an amount of 1 to 40% by weight (based on the total amount of the composition). 4. The resin material (A) contains a halogen-based flame retardant in an amount of 3 to 3.
The composite molded article according to any one of claims 1 to 3, which is a flame-retardant composition containing 25% by weight (relative to the total amount of the composition). 5. The flame-retardant resin material (B) comprises 1 to 1 of an inorganic filler.
The composite molded article according to any one of claims 1 to 4, which is a composition containing 40% by weight (relative to the total amount of the composition). 6. The composite molded article according to claim 1, wherein the flame retardant of the component (b) of the flame-retardant resin material (B) is a halogenated bisimide compound. 7. The composite molded article according to claim 1, wherein the flame retardant as the component (b) of the flame-retardant resin material (B) is a brominated epoxy resin having a molecular weight of 10,000 or more. 8. The composite molded article according to claim 1, wherein the flame retardant of the component (b) of the flame-retardant resin material (B) is polypentabromobenzyl acrylate. 9. The composite molded article according to claim 1, wherein the flame retardant as the component (b) of the flame-retardant resin material (B) is polydibromostyrene and / or polytribromostyrene. 10. A resin material (A) represented by the following (I) or (II) is injection-molded to form a primary molded article, and the primary molded article further has a flame retardant resin represented by the following (III). Material (B)
A method for producing a composite molded article having excellent airtightness and adhesiveness, which comprises secondarily injection-molding and fusion-bonding them together. (I) Copolymer mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and containing 1 to 40 mol% of other comonomer unit (II) Polyalkylene terephthalate added to the copolymer of (I) Blend containing 1 to 95% by weight of (alkylene group having 2 to 4 carbon atoms) based on the total amount (III) (a) Mainly composed of polyalkylene terephthalate (alkylene group having 2 to 4 carbon atoms) and 40 mol% or less Copolymer containing other comonomer units 40-97% by weight (b) Halogen-based flame retardant 3-25% by weight (C) Antimony compound 0-15% by weight flame-retardant resin material 11. The method for producing a composite molded article according to claim 10, wherein the resin temperature at the time of secondarily injecting the flame-retardant resin material (B) is higher than the melting point of the resin material (A) by 10 ° C. or more.