JP2005336409A - Hollow molded article and composite molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow molded article with even thickness and to provide a composite molded article with excellent welding strength by using a polymer alloy obtained by compounding at least a polybutylene terephthalate resin and a polycarbonate resin. <P>SOLUTION: The invention relates to the hollow molded article or the composite molded article using a polymer alloy compounded with at least the polybutylene terephthalate resin and the polycarbonate resin, wherein the polymer alloy has a two-phase continual structure with 0.001-5 μm structural cycle or a dispersed structure with 0.001-5 μm average particle distance on the surface of the hollow molded article or the surface of a non-welded part of the composite molded article. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hollow molded article and a composite molded article using a polymer alloy obtained by blending a polybutylene terephthalate resin and a polycarbonate resin, and utilizes the rheological properties due to the excellent regularity in the polymer alloy to form a hollow mold. It is useful as a composite molded article having a welded portion by utilizing the welding characteristics due to the excellent regularity in the polymer alloy.

  A polymer alloy composed of a polybutylene terephthalate resin and a polycarbonate resin has excellent mechanical properties, dimensional stability, and chemical resistance, and is widely used in various industrial fields. Among them, it is widely used as an automobile part.

  In the automotive field, hollow injection molding typified by gas-assist molding has recently attracted attention for the purpose of weight reduction and cost reduction by shortening the molding cycle. For this purpose, a welding method represented by laser welding has attracted attention.

  Patent Document 1 describes that a gas-assisted injection molding resin composition comprising a polybutylene terephthalate resin, a polycarbonate resin, and a filler can provide stable moldability, excellent appearance, and uniform wall thickness. However, as described in the patent document, the polybutylene terephthalate resin and the polycarbonate resin are simply melt-kneaded with a twin-screw extruder, but the moldability is improved to some extent. Depending on the case, there is a problem such as gas leakage from the thin wall portion, which is not always satisfactory, and further improvement has been demanded.

  Patent Document 2 describes that a resin composition comprising a polybutylene terephthalate resin and a polycarbonate resin is excellent as a laser beam transmission side molded article. However, as described in the patent document, the laser beam transmittance is improved to some extent by merely melt-kneading the polybutylene terephthalate resin and the polycarbonate resin with a twin screw extruder, but the welding strength is not necessarily satisfactory. Instead, further improvements were desired.

On the other hand, Patent Document 3 discloses a polymer alloy in which the structure of a resin composition comprising a polybutylene terephthalate resin and a polycarbonate resin is controlled by spinodal decomposition to have a specific range structure, and the polymer alloy has excellent strength and toughness. However, it is not disclosed for application to a hollow molded article or a composite molded article having a welded portion.
Japanese Patent Application Laid-Open No. 11-49937 (page 2, example) JP 2003-292752 A (page 2, example) JP 2003-286414 A (2nd page, Example)

  An object of the present invention is to provide a hollow molded product having a uniform thickness and a composite molded product having excellent welding strength using a polymer alloy formed by blending at least a polybutylene terephthalate resin and a polycarbonate resin. It is.

  As a result of intensive studies to provide a hollow molded product having a uniform thickness and a composite molded product having excellent welding strength, the present inventors have used a polymer alloy comprising at least a polybutylene terephthalate resin and a polycarbonate resin. On the surface of the hollow molded product and the composite molded product, the polymer alloy forms a continuous structure having a structure period of 0.001 to 5 μm, or a dispersed structure having a distance between particles of 0.001 to 5 μm. It has been found that a uniform hollow molded article and a composite molded article having excellent welding strength can be obtained, and the present invention has been completed.

That is, the present invention
(1) A hollow molded article formed by molding a polymer alloy comprising at least a polybutylene terephthalate resin and a polycarbonate resin, wherein the polymer alloy constituting the hollow molded article has a structural period on the surface of the hollow molded article A hollow molded product characterized by forming a biphasic continuous structure of less than 0.001 to 5 μm, or a dispersed structure having a distance between particles of 0.001 to 5 μm,
(2) The hollow molded article according to (1), wherein the hollow molded article is molded by a molding method selected from a gas assist molding method and an injection blow molding method, and (3) at least It is a composite molded product having a welded portion, which is formed by molding a polymer alloy formed by blending a polybutylene terephthalate resin and a polycarbonate resin, with other members, and is composed of the polymer alloy in the composite molded product. Composite molding, characterized in that the polymer alloy forms a double-phase continuous structure with a structural period of 0.001 to 5 μm or a dispersed structure with a distance between particles of 0.001 to 5 μm on the surface of the non-welded portion. Goods,
(4) The composite according to (3), wherein the welded portion is welded by a welding method selected from a laser welding method, a vibration welding method, a thermal welding method, and an ultrasonic welding method. It is a molded product.

  The polymer alloy of the present invention can be used as a hollow molded product having a uniform thickness and a composite molded product having excellent welding strength. Can be used.

  Hereinafter, the present invention will be described in more detail.

(1) Polybutylene terephthalate resin The polybutylene terephthalate resin used in the present invention is obtained by polycondensation reaction containing terephthalic acid or its ester-forming derivative and 1,4-butanediol or its ester-forming derivative as main components. It is a polymer and may contain a copolymerization component as long as the properties are not impaired, and the copolymerization amount of the copolymerization component is preferably 20 mol% or less with respect to the total monomers.

  Preferred examples of these polymers and copolymers include polybutylene terephthalate, polybutylene (terephthalate / isophthalate), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene. (Terephthalate / Naphthalate) Poly (butylene / ethylene) terephthalate and the like may be mentioned. These may be used alone or in combination of two or more.

  In addition, these polymers and copolymers have an intrinsic viscosity of 0.36 to 1.60, particularly 0.52 to 1.0 when an o-chlorophenol solution is measured at 25 ° C. from the viewpoint of moldability and mechanical properties. Those in the range of 25 are preferred, and those in the range of 0.6 to 1.0 are most preferred.

(2) Polycarbonate resin The polycarbonate resin used in the polycarbonate resin composition of the present invention includes bisphenol A, that is, 2,2′-bis (4-hydroxyphenyl) propane, 4,4′-dihydroxydiphenylalkane, or 4,4 ′. Preferred are those containing, as a main raw material, one or more dihydroxy compounds selected from -dihydroxydiphenyl sulfone and 4,4'-dihydroxydiphenyl ether. Among these, bisphenol A, that is, a product produced using 2,2′-bis (4-hydroxyphenyl) propane as a main raw material is preferable. Specifically, polycarbonate obtained by the transesterification method or the phosgene method using the above bisphenol A or the like as a dihydroxy component is preferable. Furthermore, the bisphenol A may be used in combination with other dihydroxy compounds copolymerizable therewith, such as 4,4′-dihydroxydiphenylalkane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenyl ether, and the like. The amount of other dihydroxy compounds used is preferably 10 mol% or less based on the total amount of dihydroxy compounds.

  The polycarbonate resin has a specific viscosity of 0.1 to 2.0 when 0.7 g of polycarbonate resin is dissolved in 100 ml of methylene chloride and measured at 20 ° C. from the viewpoint of excellent impact resistance and moldability. Those in the range of 0.5 to 1.5 are preferred, and those in the range of 0.8 to 1.5 are most preferred.

(3) Polymer alloy The polymer alloy used in the hollow molded product of the present invention and the composite molded product having a welded portion is composed of a polymer alloy formed by blending at least the polybutylene terephthalate resin and the polycarbonate resin. The polymer alloy forms a two-phase continuous structure with a structural period of 0.001 to 5 μm or a dispersed structure with a distance between particles of 0.001 to 5 μm on the surface and the surface of the non-welded part of the composite molded product having a welded part. It is necessary to do.

  As a method for obtaining a polymer alloy having such a structure, a method utilizing spinodal decomposition described later is preferable.

  In general, polymer alloys composed of two-component resins include compatible systems, incompatible systems, and semi-compatible systems. The compatible system is a system that is compatible in the entire range of practical temperatures above the glass transition temperature and below the thermal decomposition temperature under non-shearing in an equilibrium state. The incompatible system is a system that is incompatible in the entire region, contrary to the compatible system. A semi-compatible system is a system that is compatible in a certain temperature and composition region and incompatible in another region. Furthermore, in this semi-compatible system, there are those that undergo phase separation by spinodal decomposition depending on the conditions of the phase separation state and those that undergo phase separation by nucleation and growth.

  Furthermore, in the case of a polymer alloy comprising three or more components, a system in which all three or more components are compatible, a system in which all three or more components are incompatible, and a compatible phase having two or more components, There is a system in which the remaining one or more components are incompatible with each other, two components are in a semi-compatible system, and the remaining components are distributed in a semi-compatible system composed of these two components. In the present invention, in the case of a polymer alloy comprising three or more components including resin components other than polybutylene terephthalate resin and polycarbonate resin, the third component other than polybutylene terephthalate resin and polycarbonate resin is composed of polybutylene terephthalate resin and polycarbonate resin. A system that is distributed to at least one of them is preferred. In this case, the structure of the polymer alloy is equivalent to the incompatible structure composed of two components. The following description will be made on behalf of a polymer alloy composed of a two-component resin.

In the above incompatible system, it is possible to induce spinodal decomposition by melt kneading, and this is achieved by once compatibilizing under shear at a shear rate of 100 to 10000 sec ⁻¹ during melt kneading and then under non-shearing. The phases are separated by the so-called shear field-dependent spinodal decomposition in which the phase decomposition occurs. Since the basic part of this shear field-dependent spinodal decomposition mode is the same as the above-described general spinodal decomposition in the semi-compatible system, the spinodal decomposition in the general semi-compatible system is described below, and then the present invention is applied. A description will be given in the form of appending characteristic portions.

  In general, phase separation by spinodal decomposition refers to phase separation that occurs in an unstable state inside the spinodal curve in phase diagrams for different two-component resin compositions and temperatures. On the other hand, phase separation by nucleation and growth refers to phase separation that occurs in the metastable state inside the binodal curve and outside the spinodal curve in the phase diagram.

The spinodal curve refers to the difference (ΔGmix) between the free energy in the case of being compatible and the sum of the free energy in the incompatible phase (ΔGmix) when mixing two different resins with respect to the composition and temperature. This is a curve in which the partial differential of (φ ² ) (∂ ² ΔGmix / ∂φ ² ) becomes zero. Inside the spinodal curve, 不 安定² ΔGmix / ∂φ ² <0 is in an unstable state, and outside the spinodal curve, ∂ ² ΔGmix / ∂φ ² > 0.

  The binodal curve is a curve at the boundary between a region where the system is compatible and a region where it is incompatible with the composition and temperature.

  Here, the compatible state is a state in which they are uniformly mixed at the molecular level. Specifically, the case where the phase which consists of a different component does not form the structure of 0.001 micrometer or more is pointed out. Moreover, an incompatible state is a case where it is not a compatible state. That is, the phase which consists of a different component points out the state which forms the structure of 0.001 micrometer or more. Here, the structure of 0.001 μm or more is, for example, a two-phase continuous structure having a structural period of 0.001 to 1 μm or a dispersed structure having a distance between particles of 0.001 to 1 μm. Whether or not they are compatible is determined by, for example, an electron microscope, a differential scanning calorimeter (DSC), and various other methods as described in Polymer Alloys and Blends, Leszek A Utracki, hanser Publishers, Munich Viema New York, P64. be able to.

  According to a detailed theory, in spinodal decomposition, when the temperature of a mixed system that has been uniformly compatibilized at the temperature of the compatible region is rapidly changed to the temperature of the unstable region, the system rapidly moves toward the coexisting composition. Initiate phase separation. At that time, the concentration is monochromatized at a constant wavelength, and a two-phase continuous structure is formed in which both separated phases are continuously intertwined regularly with a structure period (Λm). After the formation of the two-phase continuous structure, the process in which only the concentration difference between the two phases increases while keeping the structure period constant is called the initial process of spinodal decomposition.

  Furthermore, the structural period (Λm) in the initial process of the above-mentioned spinodal decomposition has a thermodynamic relationship as shown in the following equation.

[Lambda] m- [| Ts-T | / Ts] ^-1/2
(Where Ts is the temperature on the spinodal curve)
Here, the two-phase continuous structure refers to a structure in which both components of the resin to be mixed each form a continuous phase and are entangled three-dimensionally. A schematic diagram of this two-phase continuous structure is described, for example, in “Polymer Alloy Fundamentals and Applications (Second Edition) (Chapter 10.1)” (edited by the Society of Polymer Science: Tokyo Kagaku Dojin).

  In the shear field-dependent spinodal decomposition, the compatible region is expanded by applying shear. In other words, since the spinodal curve changes greatly by applying shear, compared with the above general spinodal decomposition in which the spinodal curve does not change, a substantial degree of subcooling (│Ts-T│) even in the same temperature change range. Becomes larger. As a result, it becomes easy to reduce the structure period of the spinodal decomposition in the above relational expression.

  In spinodal decomposition, after going through such an initial process, it goes through a medium-term process in which an increase in wavelength and an increase in concentration difference occur simultaneously, and a later process in which an increase in wavelength occurs in a self-similar manner after the concentration difference reaches the coexisting composition. Finally, the process proceeds until separation into two macroscopic phases. In the present invention, the structure may be fixed when a desired structural period within the range defined by the present invention is reached. In addition, in the process of increasing the wavelength from the mid-stage process to the late-stage process, depending on the influence of the composition and the interfacial tension, the continuity of one phase may be interrupted and the above-described biphasic continuous structure may be changed to a dispersed structure. In this case, the structure may be fixed when a desired interparticle distance within the range defined by the present invention is reached.

  Here, the dispersed structure refers to a so-called sea-island structure in which particles that are the other phase are scattered in a matrix in which one phase is a continuous phase.

  The method of developing the structure from this initial process is not particularly limited, but a method of heat treatment at the lowest temperature or higher among the glass transition temperatures of the individual resin components constituting the polymer alloy is usually preferably used. Furthermore, when the polymer alloy is in a compatible state and has a single glass transition temperature, or when phase decomposition is in progress, the glass transition temperature of the polymer alloy is the glass transition temperature of the individual resin components that make up the polymer alloy. When it is in between, it is more preferable to heat-treat at the lowest temperature or higher among the glass transition temperatures in the polymer alloy.

  In addition, as a method of fixing the structure by spinodal decomposition, a method of fixing the structure of one or both phases of the phase-separated phase by rapid cooling or the like, and when one is a thermosetting component, the phase of the thermosetting component is used. And a method using the fact that when one is a crystalline resin, the crystalline resin phase cannot be freely moved by crystallization. In particular, when a crystalline resin is used, structure fixation by crystallization is preferably used.

  On the other hand, in a system in which phase separation is performed by nucleation and growth, a dispersed structure that is a sea-island structure is formed from the initial stage, and it grows. Therefore, the structure period of 0.001 to 5 μm is regularly arranged as in the present invention. It is difficult to form a two-phase continuous structure in the range, or a dispersed structure in the range of the distance between particles of 0.001 to 5 μm.

In order to confirm that such a biphasic continuous structure or a dispersed structure is obtained, it is important to confirm a regular periodic structure. For that purpose, for example, in addition to confirming that a biphasic continuous structure is formed by optical microscope observation or transmission electron microscope observation, in scattering measurement performed using a light scattering device or a small-angle X-ray scattering device, scattering is performed. Confirm that the maximum appears. Note that the light scattering device and the small-angle X-ray scattering device have different optimum measurement regions, so that they are appropriately selected according to the size of the structure period. The existence of the scattering maximum in this scattering measurement is a proof that a regular phase-separated structure with a certain period exists, and its period Λm corresponds to the structure period in the case of a biphasic continuous structure, and the particle in the case of a dispersed structure. Corresponds to the distance between. Further, the value is calculated by using the following equation Λm = (λ / 2) / sin (θm / 2) using the wavelength λ of the scattered light within the scatterer and the scattering angle θm giving the scattering maximum.
Can be calculated.

In order to realize the spinodal decomposition, it is necessary that the resin having two or more components is once in a compatible state and then in an unstable state inside the spinodal curve. In spinodal decomposition in a general semi-compatible system, spinodal decomposition can be caused by temperature jumping to an incompatible region after melt-kneading under compatible conditions. On the other hand, in the above-mentioned shear field-dependent spinodal decomposition, in the non-compatible system, since it is compatibilized under shear in the range of a shear rate of 100 to 10000 sec ⁻¹ at the time of melt kneading, the spinodal can be obtained only by non-shearing. Degradation can occur. The polymer alloy formed by blending the polybutylene terephthalate resin and the polycarbonate resin of the present invention belongs to the above-mentioned shear field-dependent spinodal decomposition, and is compatibilized under shear in the range of a shear rate of 100 to 10000 sec ⁻¹ during melt kneading. Only under non-shearing can cause spinodal decomposition. In the above, the shear rate is, for example, when using a parallel disk type shear applicator, a resin heated to a predetermined temperature and put in a molten state is put between the parallel disks, the distance (r) from the center, and between the parallel disks It can be obtained as ω × r / h from the interval (h) and the angular velocity (ω) of rotation.

  As a specific method for producing such a polymer alloy, a method using the above-mentioned shear field-dependent spinodal decomposition is mentioned as a preferred example. As a method for realizing compatibilization during melt-kneading, polybutylene terephthalate resin and polycarbonate resin are used. A preferable method is a method of melt-kneading under high shear stress in the kneading zone of the twin-screw extruder.

  When using such a twin-screw extruder, a higher shear stress state is formed by screw arrangement using a kneading block, lowering the resin temperature, increasing the screw rotation speed, or increasing the viscosity of the polymer used. Therefore, it can be adjusted appropriately.

  When the viscosity of the polymer used is increased to form a high shear stress state, the specific viscosity of the preferred polycarbonate resin is in the range of 0.5 to 1.5, more preferably in the range of 0.8 to 1.5. . Here, the specific viscosity of the polycarbonate resin can be determined by dissolving 0.7 g of polycarbonate in 100 ml of methylene chloride and measuring at 20 ° C.

  Although there is no restriction | limiting in particular in the compounding quantity of this polybutylene terephthalate resin and polycarbonate resin, As ratio of the compounding quantity of polybutylene terephthalate resin and polycarbonate resin, polybutylene terephthalate resin / polycarbonate resin = 10 / 90-90 / 10 ( Weight ratio) is preferable, and a range of 15/85 to 85/15 (weight ratio) is more preferable.

  In addition, the addition of a third component such as a block copolymer, a graft copolymer, or a random copolymer that further includes a component constituting the polymer alloy to the above polymer alloy reduces the free energy at the interface between the phase-separated phases. This is preferable because the structure period in the continuous structure and the distance between dispersed particles in the dispersed structure can be easily controlled. In this case, the third component such as such a copolymer is usually distributed to each phase of a polymer alloy composed of a two-component resin (in the present invention, a polybutylene terephthalate resin and a polycarbonate resin in the present invention). It can be handled in the same manner as a polymer alloy made of resin.

  Further, the polymer alloy of the present invention may further contain other thermoplastic resin or thermosetting resin within a range that does not impair the structure of the present invention. Examples of these thermoplastic resins include polyethylene, polyamide, polyphenylene sulfide, polyether ether ketone, liquid crystal polyester, polyacetal, polysulfone, polyether sulfone, polyphenylene oxide, and the like. Examples of the thermosetting resin include phenol resin, Examples include melamine resin, unsaturated polyester resin, silicone resin, and epoxy resin.

  These other thermoplastic resins and thermosetting resins can be blended at any stage for producing the polymer alloy of the present invention. For example, a method of simultaneously adding a polybutylene terephthalate resin and a polycarbonate resin, a method of adding a polybutylene terephthalate resin and a polycarbonate resin after melt-kneading in advance, and a polybutylene terephthalate resin and a polycarbonate resin at the beginning, A method of adding the remaining resin to one of the resins, melt-kneading, and the like can be used.

  The polymer alloy of the present invention may further contain various additives as long as the object of the present invention is not impaired. Examples of these additives include talc, kaolin, mica, clay, bentonite, sericite, basic magnesium carbonate, aluminum hydroxide, glass flake, glass fiber, carbon fiber, asbestos fiber, rock wool, calcium carbonate, silica Sand, wollastonite, barium sulfate, glass beads, titanium oxide and other reinforcing materials, non-plate-like fillers, or antioxidants (phosphorous, sulfur, etc.), UV absorbers, heat stabilizers (hindered phenols, etc.) ), Transesterification inhibitors, lubricants, mold release agents, antistatic agents, antiblocking agents, colorants including dyes and pigments, flame retardants (halogen-based, phosphorus-based, etc.), flame retardant aids (antimony trioxide) Representative antimony compounds, zirconium oxide, molybdenum oxide, etc.), foaming agents, coupling agents (epoxy groups, amino acids) Group a mercapto group, a vinyl group, an isocyanate group one or more containing a silane coupling agent or titanium coupling agent), an antibacterial agent, and the like.

  These additives can be blended at any stage for producing the polymer alloy of the present invention. For example, a method of simultaneously adding a polybutylene terephthalate resin and a polycarbonate resin, a method of adding a polybutylene terephthalate resin and a polycarbonate resin after melt-kneading in advance, and a polybutylene terephthalate resin and a polycarbonate resin at the beginning, A method of adding the remaining resin to one of the resins, melt-kneading, and the like can be used.

(4) Hollow molded product The hollow molded product of the present invention is a surface of the hollow molded product. It is necessary to form a dispersion structure of less than. As a method for obtaining a polymer alloy having such a structure, the above-described method utilizing spinodal decomposition is preferable. Furthermore, in order to obtain a hollow molded product having a more uniform thickness, the surface of the hollow molded product has a two-phase continuous structure with a structural period of 0.002 to 1 μm, or a distance between particles of 0.002 to 1 μm. It is preferable to control to a dispersed structure, and furthermore, to control to a dispersed structure having a two-phase continuous structure in the range of the structural period of 0.003 to 0.5 μm or a distance between the particles of 0.003 to 0.5 μm. More preferably, it is most preferable to control to a two-phase continuous structure having a structural period of 0.003 to 0.3 μm or a dispersed structure having a distance between particles of 0.003 to 0.3 μm. In this invention, since the polymer alloy which gives the hollow molded article which has such a fine phase structure is used, a hollow molded article with uniform thickness can be obtained.

  As described above, the hollow molded product is prepared by melting and kneading polybutylene terephthalate resin and polycarbonate resin under a sufficiently high shear stress using a twin-screw extruder or the like, and once compatibilizing them. By discharging in a sheet form and cooling immediately after discharge, the two-component resin is in a state in which the structure is fixed in a compatible state or the initial period of spinodal decomposition is a continuous phase of 0.1 μm or less. It is processed into a pellet by cutting a gut or sheet having a structure, more preferably a two-component resin in a compatible state and the structure is fixed, and various hollow moldings are performed using the pellet. As a result, a hollow molded product can be obtained.

On the surface of the hollow molded article of the present invention, the polymer alloy preferably has a two-phase continuous structure with a structural period of 0.001 to 5 μm or a dispersed structure with a distance between particles of 0.001 to 5 μm. After producing a pellet in a state in which the resin is in a compatible state and the structure is fixed, or in a state having a biphasic continuous structure with a structural period of 0.1 μm or less, which is an initial state of spinodal decomposition,
This pellet is molded, and spinodal decomposition is further advanced in the molding process to form a biphasic continuous structure having a structural period of 0.001 to 5 μm or a dispersed structure having a distance between particles of 0.001 to 5 μm. And a method of fixing the structure.

  The hollow molded product in the present invention is obtained by injecting various media such as gas or liquid into the molten resin, and preferred examples of the molding method include a gas assist molding method and an injection blow molding method.

In the gas assist molding method, a pellet made of the polymer alloy is melted, and a molten resin is injected and filled into a mold cavity. After the molten resin is injected or filled, a pressurized gas such as nitrogen is supplied by a nozzle or a needle. It is a molding method that is poured into molten resin. The gas assist molding method can be performed according to a normal method using a normal gas assist molding machine. For example, the injection amount of the molten resin is preferably in the range of 30 to 80% of the mold cavity volume, and more preferably in the range of 50 to 70%. The gas injection pressure is not particularly limited, and may be selected according to the melt viscosity of the polymer alloy. For example, a preferable injection pressure is in the range of 5 to 500 kg / cm ² . Here, in the injection filling step, the injection is filled in an amount smaller than the cavity volume according to the volume of the hollow part of the molded body, but when the injection resin is injected non-uniformly into the mold cavity and flow-deformed, the molding is performed. A hesitation mark or the like is generated on the product, and the appearance characteristics deteriorate. On the other hand, when injection filling using the polymer alloy of the present invention, due to the rheological properties due to the excellent regularity, flow deformation is suppressed, and by injection into a uniform shape in the mold cavity, the wall thickness is increased. Is uniform, can suppress the formation of multiple wrinkle-like hesitation marks and the like, and can provide a hollow molded product having a uniform surface and excellent appearance characteristics.

  The injection blow molding method is a molding method in which a preform, which is a template of a molded product, is first molded by injection molding, and a hollow molded product is obtained by blowing air into the preform. Here, in the preform molding step, if non-uniform crystallization occurs due to non-uniformity of the resin used, it becomes difficult to stably swell the preform in the next blowing stage. On the other hand, when preform molding is performed using the above-mentioned pellets, the irregularity of crystallization in the preform is reduced due to excellent regularity, so that the preform can be stably expanded in the next blowing stage. Thus, a hollow molded product having a uniform surface and excellent appearance characteristics can be obtained.

(5) Composite molded product The composite molded product of the present invention is a composite molded product having a welded portion using a polymer alloy formed by blending a polybutylene terephthalate resin and a polycarbonate resin as described above, On the surface of the non-welded portion constituted by the polymer alloy, the polymer alloy forms a biphasic continuous structure having a structural period of 0.001 to less than 5 μm, or a dispersed structure having an interparticle distance of less than 0.001 to 5 μm. It is necessary to be. The composite molded product of the present invention uses a molded product obtained by molding the polymer alloy at least in part, and may be made of other members (alloys similar to the polymer alloy described above, or different resins). Alternatively, the former may be preferable in view of obtaining excellent welding strength, and the number of such other members may be one or more. It is made. In this way, when welding a molded article composed of the polymer alloy having a specific structural period (inter-particle distance), it is considered that the welding behavior is stably improved due to the rheological properties due to excellent regularity. It is done. In the present invention, the structural period (inter-particle distance) of the polymer alloy constituting the composite molded article is measured at the surface of the non-welded part because the structural period (inter-particle distance) of the polymer alloy directly at the weld part after welding ) Is difficult to measure, and usually the phase structure of the surface of the welded portion before welding is substantially the same as the phase structure of the surface of the non-welded portion.

    The molded article composed of the above polymer alloy is, as described above, once melted and kneaded with a polybutylene terephthalate resin and a polycarbonate resin under a sufficiently high shear stress using a twin screw extruder or the like, By discharging from an extruder in a gut or sheet form and cooling immediately after discharge, the structure period in which the structure of the two-component resin is in a compatible state or the initial state of spinodal decomposition is 0. It is processed into a pellet by cutting a gut or a sheet having a two-phase continuous structure of 1 μm or less, more preferably a two-component resin in a compatible state and the structure is fixed, and further using such a pellet Thus, a molded product can be obtained by molding, for example, injection molding. In such a molded article, the polymer alloy forms a double-phase continuous structure having a structural period of less than 0.001 to 5 μm or a dispersed structure having an interparticle distance of less than 0.001 to 5 μm on its surface. As a method for obtaining a polymer alloy having a simple structure, the above-described method utilizing spinodal decomposition is preferred. Furthermore, in order to obtain a composite molded article having better welding strength, a two-phase continuous structure having a structural period in the range of 0.002 to 1 μm or a distance between particles of 0.002 on the surface of the non-welded portion of the composite molded article. It is preferable to control to a dispersed structure in the range of ˜1 μm, and further, a biphasic continuous structure in the range of the structural period of 0.003 to 0.5 μm, or a dispersed structure in the range of the inter-particle distance of 0.003 to 0.5 μm. It is more preferable to control to a two-phase continuous structure with a structural period of 0.003 to 0.3 μm or a dispersed structure with a distance between particles of 0.003 to 0.3 μm. preferable.

  Next, a composite molded product can be obtained by welding the molded product and another member.

  The composite molded article having a welded portion in the present invention is obtained by welding by various welding methods, and preferable welding methods include laser welding, vibration welding, thermal welding, and ultrasonic welding. .

  In the laser welding method, a laser welding test piece using a material that transmits a laser beam is placed on the upper part, and a laser welding test piece using a material that absorbs the laser beam is placed on the lower part. It is a method. Usually, laser irradiation is performed along the laser welding trajectory, and the laser welding conditions are not particularly limited, but for example, an output of 10 to 50 W and a laser scanning speed of 1 to 50 mm / sec are exemplified as preferable laser welding conditions. Can do. Here, when laser welding is performed using the polymer alloy of the present invention, a composite molded article having a welded portion having improved welding strength stably due to excellent regularity can be obtained. Further, the polymer alloy of the present invention is not only effective as a material that transmits a laser beam, but can also be used effectively as a material that absorbs a laser beam by blending carbon black or the like.

The vibration welding method is a welding method using frictional heat, and while pressing the adhesive surfaces at about 0.1 to 0.6 MPa, the vibration width is about 0.5 to 2.0 mm and the frequency is about 100 Hz. It is a method of melting and joining by applying vibration and applying frictional heat.
Here, when vibration welding is performed using the polymer alloy of the present invention, a composite molded article having a welded portion having improved welding strength stably due to excellent regularity can be obtained.

In the heat welding method, the part to be welded is melted by bringing it into contact with a heated hot plate,
Thereafter, the hot plate is peeled off, the melted parts to be welded are held in abutted state, and the heat welding is performed. Here, when the polymer alloy of the present invention is used for thermal welding, a composite molded article having a welded portion having improved welding strength stably due to excellent regularity can be obtained.

  The ultrasonic welding method is a method of melting and bonding by utilizing the characteristic that vibration energy is converted into heat energy in the resin by generating vibration energy by ultrasonic vibration to the resin. Here, when ultrasonic welding is performed using the polymer alloy of the present invention, a composite molded article having a welded portion having improved welding strength stably due to the excellent regularity of the polymer alloy can be obtained.

  The hollow molded article and the composite molded article having a welded portion of the present invention can be widely used for automobile parts, electrical parts, and the like, and among them, can be suitably used as automobile parts.

  Examples of automobile parts include alternator terminals, alternator connectors, IC regulators, light meter potentiometer bases, air intake nozzle snorkels, intake manifolds, air flow meters, air pumps, fuel pumps, engine coolant joints, thermostat housings, carburetors Main body, carburetor spacer, engine mount, ignition hobbin, ignition case, clutch bobbin, sensor housing, idle speed control valve, vacuum switching valve, ECU housing, vacuum pump case, inhibitor switch, rotation sensor, acceleration sensor, distributor cap, Coil base, Actuator for ABS -Case, radiator tank top and bottom, cooling fan, fan shroud, engine cover, cylinder head cover, oil cap, oil pan, oil filter, fuel cap, fuel strainer, distributor cap, vapor canister housing, air cleaner housing, timing belt Covers, brake booster parts, various cases, various tubes for fuel / exhaust / intake systems, various tanks, various hoses for fuel / exhaust / intake systems, various clips, various valves such as exhaust gas valves, various Pipe, exhaust gas sensor, cooling water sensor, oil temperature sensor, brake pad wear sensor, brake pad wear sensor, throttle position sensor, crankshaft Transition sensor, air conditioning thermostat base, air conditioning panel switch board, heating hot air flow control valve, radiator motor brush holder, water pump impeller, turbine vane, wiper motor related parts, step motor rotor, brake piston, solenoid bobbin, engine oil Filter, igniter case, torque control lever, starter switch, starter relay, safety belt parts, register blade, washer lever, window regulator handle, window regulator handle knob, passing light lever, distributor, sun visor bracket, various motors Housing, roof rail, fender, garnish, bumper, door Mirror stay, horn terminal, window washer nozzle, spoiler, hood louver, wheel cover, wheel cap, grill apron cover frame, lamp reflector, lamp socket, lamp housing, lamp bezel, door handle, wire harness connector, SMJ connector, PCB connector And various connectors such as a door grommet connector and a fuse connector.

  Hereinafter, an example is given and the effect of the present invention is further explained.

[Examples 1 to 3]
The raw material which consists of a composition of Table 1 was set to the extrusion temperature of 270 degreeC, it was set as the screw arrangement which provided the two kneading zones, and it turned into the twin-screw extruder (Ikegai Kogyo Co., Ltd. PCM-30) which was 300 rpm. The gut after being supplied and discharged from the die was rapidly cooled in ice water. The guts in each example are transparent, and the gut is stained with polycarbonate by iodine staining, and then the sample obtained by cutting out an ultrathin section is magnified 100,000 times with a transmission electron microscope and observed. Although it went, about any sample, the structure of 0.001 micrometer or more was not seen but it confirmed that it was compatibilizing.

  Next, the gut discharged from the die was rapidly cooled by passing through a cooling bath filled with water adjusted to 10 ° C. over 15 seconds to fix the structure, and then pelletized with a strand cutter to obtain pellets.

The obtained pellets were supplied to a gas assist injection molding machine set to a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and injection molding was performed with the resin injection amount being about 70% of the mold cavity volume. Two seconds after the injection, compressed nitrogen gas having a pressure of 100 kg / cm ² was injected into the injection resin from a movable needle disposed in the mold cavity to swell the resin and transferred it into the mold cavity. Thereafter, the compressed and pressurized state with gas was released, and the molded product was taken out.

  Table 1 shows the results of evaluating the moldability of the obtained molded product as follows.

(1) Uneven thickness ○: Gas is almost uniformly filled and has a uniform thickness of about 2 mm.

  Δ: A thick portion of about 5 mm and a thin portion of about 1 mm are observed.

  X: Some gas leak traces are seen.

(2) Sink marks The number of sink marks in a 50-shot hollow molded article was observed.

(3) Appearance ○: No appearance defect due to jetting or bumps.

  Δ: Appearance failure due to jetting.

  X: Appearance defect due to jetting and butts

  Further, an ultrathin section was cut out from the surface of the molded article subjected to the gas assist molding, and the state of the structure was observed from a transmission electron micrograph in the same manner as the gut. In the electron micrograph, a two-phase continuous structure in which a polycarbonate phase dyed in black and a white polybutylene terephthalate phase form a continuous phase with each other and a dispersed structure with a uniform inter-particle distance were observed.

Moreover, the structural period of the above biphasic continuous structure and the dispersed structure was measured by small angle X-ray scattering. Table 1 shows the result of calculating the structural period (Λm) from the peak position (θm) by the following formula in small-angle X-ray scattering.
Λm = (λ / 2) / sin (θm / 2).

[Comparative Examples 1 to 3]
A gut was obtained by performing melt kneading in the same manner as in Examples 1 to 3, except that the raw materials having the compositions shown in Table 1 were used and the screw rotation speed was set to 100. The guts of Comparative Examples 1 to 3 were all opaque. For these samples, pellets and hollow molded articles were produced in the same manner as in Examples 1 to 3, and molding evaluation was performed in the same manner as in Examples 1 to 3, and the results are shown in Table 1.

  Further, an ultrathin section was cut out from the surface of the molded article subjected to the gas assist molding, and the state of the structure was observed from a transmission electron micrograph in the same manner as the gut. In any of Comparative Examples 1 to 3, a large structure was observed in the electron micrograph, and a structure in which dispersed particles of 5 μm or more were dispersed non-uniformly was observed.

  In the examples and comparative examples, the following resins were used.

PBT: Polybutylene terephthalate (“Toraycon” 1100S manufactured by Toray Industries, Inc., glass transition temperature 32 ° C., crystal melting temperature 220 ° C.)
PC: Polycarbonate resin (“Iupilon” E2000, manufactured by Mitsubishi Engineering Plastics Co., Ltd., glass transition temperature 151 ° C., 0.7 g dissolved in 100 ml of methylene chloride, specific viscosity 1.18 measured at 20 ° C.)
[Examples 4 to 6]
The raw material which consists of a composition of Table 2 was set to the extrusion temperature of 270 degreeC, it was set as the screw arrangement which provided the two kneading zones, and the screw rotation speed was set to 300 rpm. The gut after being supplied and discharged from the die was rapidly cooled in ice water. The guts in each example are transparent, and the gut is stained with polycarbonate by iodine staining, and then the sample obtained by cutting out an ultrathin section is magnified 100,000 times with a transmission electron microscope and observed. Although it went, about any sample, the structure of 0.001 micrometer or more was not seen but it confirmed that it was compatibilizing.

  Next, the gut discharged from the die was rapidly cooled by passing through a cooling bath filled with water adjusted to 10 ° C. over 15 seconds to fix the structure, and then pelletized with a strand cutter to obtain pellets.

  The obtained pellets were supplied to an injection molding machine set at a cylinder temperature of 270 ° C. and a mold temperature of 80 ° C., and a test piece of width × length × thickness = 24 mm × 70 mm × 3 mm was molded, A test piece was obtained. A test piece on the laser beam absorption side was prepared using a material in which 0.4 parts by weight of carbon black was mixed with 100 parts by weight of polybutylene terephthalate resin. Using two of these test pieces, the test piece on the laser beam transmission side is arranged on the top so that the range of 30 mm in length overlaps, and the output is 20 W from the upper part, the laser scanning speed is 10 mm / sec, the focal length is 38 mm, Laser welding was performed at a focal length of 0.6 mm.

  Table 2 shows the results of evaluating the weldability of the obtained composite molded article as follows.

(1) Weldability ○: There is no melt mark on the incident surface of the laser beam and welding is possible.

  Δ: Melting marks are observed on the incident surface of the laser beam, but welding is possible.

  X: Melting marks are observed on the incident surface of the laser beam, and welding is impossible.

(2) Welding strength Using a tensile tester (AG-500B), a tensile test was performed at a tensile speed of 1 mm / min and a span of 40 mm so that a tensile shear stress was applied to the welded part. Asked.

  Further, an ultrathin section was cut out from the surface of the non-welded part of the molded article subjected to the laser welding, and the state of the structure was observed from a transmission electron micrograph as in the case of the gut. In the electron micrograph, a two-phase continuous structure in which a polycarbonate phase dyed in black and a white polybutylene terephthalate phase form a continuous phase with each other and a dispersed structure with a uniform inter-particle distance were observed.

Moreover, the structural period of the above biphasic continuous structure and the dispersed structure was measured by small angle X-ray scattering. Table 2 shows the result of calculating the structural period (Λm) from the peak position (θm) by the following formula in small-angle X-ray scattering.
Λm = (λ / 2) / sin (θm / 2).

[Comparative Examples 4 to 6]
A raw material having the composition shown in Table 2 was melt kneaded in the same manner as in Examples 4 to 6 except that the screw rotation speed was set to 100 to obtain a gut. The guts of Comparative Examples 4 to 6 were all opaque. For these samples, pellets and composite molded products by laser welding were prepared in the same manner as in Examples 4 to 6, and the weldability was evaluated in the same manner as in Examples 4 to 6, and the results are shown in Table 2.

  Further, an ultrathin section was cut out from the surface of the non-welded part of the molded article subjected to the laser welding, and the state of the structure was observed from a transmission electron micrograph as in the case of the gut. In any of Comparative Examples 4 to 6, a large structure was observed in the electron micrograph, and a structure in which dispersed particles of 5 μm or more were dispersed unevenly was observed.

  In the examples and comparative examples, the following resins were used.

PBT: Polybutylene terephthalate (“Toraycon” 1100S manufactured by Toray Industries, Inc., glass transition temperature 32 ° C., crystal melting temperature 220 ° C.)
PC: Polycarbonate resin (“Iupilon” E2000, manufactured by Mitsubishi Engineering Plastics Co., Ltd., glass transition temperature 151 ° C., 0.7 g dissolved in 100 ml of methylene chloride, specific viscosity 1.18 measured at 20 ° C.)

Claims (4)

A hollow molded article formed by molding a polymer alloy comprising at least a polybutylene terephthalate resin and a polycarbonate resin, and the polymer alloy constituting the hollow molded article on the surface of the hollow molded article has a structural period of 0.001. A hollow molded article characterized by forming a continuous structure having a double phase of ˜5 μm or a dispersed structure having a distance between particles of 0.001 to 5 μm. The hollow molded article according to claim 1, wherein the hollow molded article is molded by a molding method selected from a gas assist molding method and an injection blow molding method. A composite molded product having a welded portion, which is formed by molding a polymer alloy formed by blending at least a polybutylene terephthalate resin and a polycarbonate resin with another member, and is composed of the polymer alloy in the composite molded product The composite in which the polymer alloy forms a continuous structure of both phases with a structural period of 0.001 to 5 μm or a dispersed structure with a distance between particles of 0.001 to 5 μm on the surface of the non-welded portion. Molding. The composite molded article according to claim 3, wherein the welded portion is welded by a welding method selected from a laser welding method, a vibration welding method, a thermal welding method, and an ultrasonic welding method.