JP6865532B2 - Polymethylpentene resin composition - Google Patents

Description

The present invention relates to a polymethylpentene resin composition in which heat resistance and fluidity are significantly improved as compared with a single polymethylpentene resin by incorporating a liquid crystal polyester having a specific crystal melting temperature.

Plastic materials are widely used in the fields of daily necessities, home appliances, electricity and electronics, automobiles, agriculture, industry, and aerospace. The main reason why plastic materials, especially thermoplastic resins, are widely used is that they are superior in ease of molding and light weight as compared with metal materials and ceramic materials.

Among plastic materials, polyolefin resins such as polypropylene resin and polyethylene resin are used for various purposes, but due to their low mechanical properties and heat resistance, they are not used for parts exposed to harsh environments. The current situation is that it is difficult.

Polyamide resin and polycarbonate resin, which are general-purpose engineering plastics, are preferably used as materials having high mechanical strength and heat resistance as members used in a harsh environment, but these resins are compared with polyolefin resins. Since the specific gravity is large, the weight is inferior, and the high heat resistance impairs the ease of molding.

Especially in the fields of electricity / electronics and machinery, it is easy to carry, and in the fields of automobiles, aerospace, and energy saving, it is a high machine with excellent lightness and moldability. There is a demand for a thermoplastic resin having strength and heat resistance.

From this point of view, various thermoplastic resins have been developed in recent years. For example, a thermoplastic resin composition in which a polyamide resin or a polybutylene terephthalate resin is blended with a polyolefin resin has been proposed (Patent Documents 1 and 2). However, the resin composition described in Patent Document 1 has a high water absorption rate, a large decrease in strength during water absorption, and insufficient resistance to calcium chloride, which is widely used as a road antifreeze agent. , The usable range was limited. Further, although the resin composition described in Patent Document 2 has high strength, it is inferior in lightness due to its large specific gravity, and it cannot be said that the molding processability is also good.

On the other hand, polymethylpentene resin, which is one of the polyolefin resins, has a high crystal melting temperature among polyolefin resins, has excellent heat resistance, and is lightest among widely used thermoplastic resins to reduce weight. Is being considered for use in fields where

However, the polymethylpentene resin cannot be said to have sufficient molding processability, and is not suitable for use in fields requiring higher heat resistance.

Therefore, there has been a demand for the development of a thermoplastic resin having improved heat resistance and molding processability while maintaining the light weight characteristic of the polymethylpentene resin.

Japanese Unexamined Patent Publication No. 9-059438 Japanese Unexamined Patent Publication No. 2005-263933

An object of the present invention is to provide a polymethylpentene resin composition having improved heat resistance and fluidity as compared with a single polymethylpentene resin. Another object of the present invention is to provide a polymethylpentene resin composition in which a liquid crystal polymer is uniformly dispersed without adding a compatibilizer.

As a result of diligent studies on improving the heat resistance and fluidity of the polymethylpentene resin, the present inventors have excellent heat resistance and fluidity by blending the polymethylpentene resin with a liquid crystal polymer having a predetermined crystal melting temperature. They have found that a polymethylpentene resin composition can be obtained, and have completed the present invention.

That is, the present invention provides a polymethylpentene resin composition containing 0.1 to 100 parts by weight of a liquid crystal polymer having a crystal melting temperature of 300 ° C. or lower with respect to 100 parts by weight of the polymethylpentene resin.

The polymethylpentene resin composition of the present invention is excellent in heat resistance and fluidity, and is lightweight, so that it is suitably used as a material in fields such as electricity / electronics, machinery, automobiles, and aerospace. Be done.

Further, since a compatibilizer is not required for kneading the polymethylpentene resin and the liquid crystal polymer, the steps such as premixing can be simplified, and the resin composition can be provided inexpensively and easily. is there. Further, it is possible to avoid deterioration of the resin performance due to thermal decomposition of the compatibilizer during kneading and molding.

The polymethylpentene resin used in the present invention is a polymer composed of a monomer containing 4-methyl-1-pentene, a homopolymer of 4-methyl-1-pentene, or 4-methyl-1-pentene and others. It may be a copolymer with the monomer of.

Other monomers include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, Examples thereof include 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 3-ethyl-1-hexene and the like, which can be used alone or in combination of two or more.

The crystal melting temperature of the polymethylpentene resin used in the present invention is not particularly limited, but is preferably 180 ° C. or higher, more preferably 190 ° C. or higher, and further preferably 200 ° C. or higher in terms of excellent heat resistance. Is particularly preferred.

In the present invention, the "single polymethylpentene resin" means a resin containing only the above-mentioned polymethylpentene resin as a resin component.

In the present invention, the liquid crystal polymer blended in the polymethylpentene resin forms an anisotropic molten phase, which is called a thermotropic liquid crystal polymer by those skilled in the art, and has a crystal melting temperature of 300 ° C. or lower. As long as it is a certain liquid crystal polymer, it is not particularly limited.

The properties of the anisotropic molten phase can be confirmed by a normal deflection inspection method using an orthogonal deflector, that is, by observing a sample placed on a hot stage in a nitrogen atmosphere.

In the present invention, as a liquid crystal polymer satisfying a crystal melting temperature range of 300 ° C. or lower, a liquid crystal polyester containing a repeating unit represented by the formulas [I] and [II] is preferably used. Further, liquid crystal polyesters composed of repeating units represented by the formulas [I] and [II] are particularly preferably used.

In the present specification and claims, "liquid crystal polyester containing a repeating unit represented by the formula [I] and the formula [II]" means that the liquid crystal polymer is a constituent component thereof in the formulas [I] and [II]. In addition to the repeating unit represented by, it means that other repeating units may be contained as long as the crystal melting temperature of the liquid crystal polymer is 300 ° C. or lower.

Further, in the present specification and claims, "liquid crystal polyester composed of repeating units represented by the formulas [I] and [II]" means that the liquid crystal polymer is a constituent component of the formula [I] and the formula [I]. It means a liquid crystal polyester containing 90 mol% or more of the repeating units represented by the formula [II] in total.

Some liquid crystal polyesters composed of these repeating units form an anisotropic molten phase and some do not form an anisotropic molten phase, depending on the constituent components, the composition ratio in the polymer, and the sequence distribution. The liquid crystal polyester used in the present invention is limited to one that forms an anisotropic molten phase.

The liquid crystal polymer used in the present invention preferably contains the repeating unit represented by the formula [I] in an amount of 20 mol% or more, more preferably 25 to 45 mol%, based on all the repeating units. When the repeating unit represented by the formula [I] is less than 20 mol% in all the repeating units, the crystal melting temperature of the liquid crystal polymer tends to be high, which is not preferable.

Examples of the monomer giving the repeating unit represented by the formula [I] include 6-hydroxy-2-naphthoic acid and ester-forming derivatives such as acylates, ester derivatives and acid halides thereof.

Examples of the monomer giving the repeating unit represented by the formula [II] include 4-hydroxybenzoic acid and ester-forming derivatives such as acylates, ester derivatives and acid halides thereof.

The main repeating units other than the repeating units represented by the formulas [I] and [II] that constitute the liquid crystal polymer used in the present invention are (1) aromatic oxycarbonyl repeating units and (2) aromatic dicarbonyl repeating units. Units and (3) aromatic dioxy repeating units.

(1) Specific examples of the monomer giving an aromatic oxycarbonyl repeating unit include metahydroxybenzoic acid, orthohydroxybenzoic acid, 5-hydroxy-2-naphthoic acid, and 3-hydroxy-2-naphthoic acid. 4'-Hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, their alkyl, alkoxy or halogen substituents, and their acylates, esters. Examples thereof include ester-forming derivatives such as derivatives and acid halides.

(2) Specific examples of the monomer giving an aromatic dicarbonyl repeating unit include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. Acids, aromatic dicarboxylic acids such as 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, alkyl, alkoxy or halogen substituents thereof, and ester-forming derivatives such as their ester derivatives and acid halides. Can be mentioned. Among these, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferable because the mechanical properties, heat resistance, crystal melting temperature, and moldability of the obtained liquid crystal polyester can be easily adjusted to appropriate levels.

(3) Specific examples of the monomer giving an aromatic dioxy repeating unit include hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, and 1,4-. Aromatic diols such as dihydroxynaphthalene, 4,4'-dihydroxybiphenyl (4,4'-biphenol), 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, etc. , These alkyl, alkoxy or halogen substituents, and ester-forming derivatives such as their acylated products. Among these, hydroquinone and 4,4'-dihydroxybiphenyl are preferable from the viewpoint of reactivity at the time of polymerization and the characteristics of the obtained liquid crystal polyester.

The repeating unit contained in the liquid crystal polymer used in the present invention and the monomer giving it have been described above. However, the liquid crystal polymer used in the present invention has a crystal melting temperature of 300 ° C. or less measured by a differential scanning calorimeter. Anything is fine.

In the present specification and claims, the "crystal melting temperature" means crystal melting when measured at a heating rate of 20 ° C./min by a differential scanning calorimetry (hereinafter abbreviated as DSC). Temperature Obtained from the peak temperature. More specifically, after observing the heat absorption peak temperature (Tm1) observed when the liquid crystal polymer sample is measured at a temperature rising condition of 20 ° C./min from room temperature, it is held at a temperature 50 ° C. higher than Tm1 for 10 minutes. Then, after cooling the sample to room temperature under the temperature lowering condition of 20 ° C./min, the heat absorption peak when measured again under the temperature rising condition of 20 ° C./min was observed, and the temperature indicating the peak top was determined by the liquid crystal polymer. Let it be the crystal melting temperature. As the measuring device, for example, Exstar6000 manufactured by Seiko Instruments Co., Ltd. can be used.

The upper limit of the crystal melting temperature of the liquid crystal polymer used in the present invention is 300 ° C. or lower, preferably 295 ° C. or lower, and more preferably 290 ° C. or lower.

When the crystal melting temperature of the liquid crystal polymer exceeds 300 ° C., the polymethylpentene resin is decomposed during kneading and molding, so that the excellent properties of the polymethylpentene resin such as mechanical strength and heat resistance tend to be impaired. There is.

The lower limit of the crystal melting temperature of the liquid crystal polymer used in the present invention is preferably 180 ° C. or higher. When the crystal melting temperature of the liquid crystal polymer is lower than 180 ° C., the dispersion of the liquid crystal polymer phase in the polymethylpentene continuous phase tends to be non-uniform.

The liquid crystal polymer preferably used in the present invention can obtain a liquid crystal polymer having a crystal melting temperature of 300 ° C. or lower by containing the repeating units represented by the formulas [I] and [II].

The liquid crystal polymer used in the present invention preferably has a melt viscosity measured by a capillary rheometer of 1 to 1000 Pa · s, and more preferably 5 to 300 Pa · s.

The method for producing the liquid crystal polymer used in the present invention is not particularly limited, and a known polycondensation method for polyester that forms an ester bond with the above-mentioned monomer components, for example, a molten acidlysis method, a slurry polymerization method, or the like can be used.

The molten acidlysis method is a method suitable for producing the liquid crystal polymer used in the present invention, and this method first heats a monomer to form a melt of a reactant and continues the reaction. To obtain a molten polymer. A vacuum may be applied to facilitate the removal of volatiles (eg, acetic acid, water, etc.) that are by-produced in the final stage of condensation.

The slurry polymerization method is a method of reacting in the presence of a heat exchange fluid, and the solid product is obtained in a state of being suspended in a heat exchange medium.

In both the melt acidlysis method and the slurry polymerization method, the polymerizable monomer component used in producing the liquid crystal polymer reacts at room temperature as a modified form in which a hydroxyl group is acylated, that is, a lower acylated product. It can also be provided. The lower acyl group preferably has 2 to 5 carbon atoms, and more preferably 2 or 3 carbon atoms. Particularly preferably, a method of using the acetylated product of the monomer component in the reaction can be mentioned.

As the lower acylated product of the monomer, a product that is separately acylated and synthesized in advance may be used, or an acylating agent such as acetic anhydride may be added to the monomer during the production of the liquid crystal polymer to produce the monomer in the reaction system. ..

In either case of the melt acidlysis method or the slurry polymerization method, a catalyst may be used at the time of the reaction, if necessary.

Specific examples of the catalyst include organic tin compounds such as dialkyltin oxide (eg dibutyltin oxide) and diaryltin oxide; organic titanium compounds such as titanium dioxide, antimony trioxide, alkoxytitanium silicate, and titanium alkoxide; alkalis and alkalis of carboxylic acids. Earth metal salts (eg potassium acetate); _{gaseous acid catalysts such as Lewis acid (eg BF 3} ), hydrogen halides (eg HCl) and the like.

The ratio of the catalyst used is usually 10 to 1000 ppm, preferably 20 to 200 ppm, based on the monomer.

The liquid crystal polymer obtained by such a polycondensation reaction is extracted from the polymerization reaction tank in a molten state, processed into pellets, flakes, or powder, and subjected to mixing with a polymethylpentene resin. To.

In the polymethylpentene resin composition of the present invention, the blending ratio of the polymethylpentene resin and the liquid crystal polymer is 0.1 to 100 parts by weight, preferably 1 to 90 parts by weight, based on 100 parts by weight of the polymethylpentene resin. , More preferably 2 to 70 parts by weight, still more preferably 5 to 50 parts by weight.

If the ratio of the liquid crystal polymer to 100 parts by weight of the polymethylpentene resin is less than 0.1 parts by weight, the effect of improving heat resistance and fluidity cannot be sufficiently obtained. If the ratio of the liquid crystal polymer exceeds 100 parts by weight, the lightness of the obtained polymethylpentene resin composition is impaired.

The polymethylpentene resin composition of the present invention is characterized in that the crystal melting temperature of the liquid crystal polymer to be mixed is 300 ° C. or lower, so that the liquid crystal polymer is uniformly dispersed in the polymethylpentene resin which is a matrix resin, and the object of the present invention is It can be a resin composition having excellent heat resistance and fluidity.

Therefore, a compatibilizer is not particularly required for mixing, but a compatibilizer may be added for the purpose of improving the compatibility between the polymethylpentene resin and the liquid crystal polymer. Here, the compatibilizer refers to one that is localized at the interface between the phases of each polymer constituting the mixed polymer and has a function of reducing the interfacial tension between the phases.

The type of compatibilizer is not particularly limited as long as the object of the present invention is achieved, but conventionally known ones, for example, those described in JP-A-2014-148616 can be used. When the compatibilizer is added, it is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the polymethylpentene resin.

The polymethylpentene resin composition of the present invention preferably has a specific gravity of 1.00 g / cm ³ or less, and ^{more preferably 0.95 g / cm 3} or less. If the specific gravity ^{exceeds 1.00 g / cm 3} , the lightness characteristic of the polymethylpentene resin is impaired, and it tends to be unsuitable for use as a lightweight member.

The polymethylpentene resin composition of the present invention may contain an inorganic filler and / or an organic filler, if necessary.

Examples of the inorganic filler and / or organic filler that may be blended in the polymethylpentene resin composition of the present invention include glass fiber, silica alumina fiber, alumina fiber, carbon fiber, potassium titanate whisker, and aluminum borate. One or more selected from the group consisting of whisker, aramid fiber, talc, mica, graphite, wollastonite, dolomite, clay, glass flakes, glass beads, glass balloons, calcium carbonate, barium sulfate, and titanium oxide. .. Among these, glass fiber is preferable because it has an excellent balance between physical properties and cost.

When an inorganic filler and / or an organic filler is used, the blending amount of the filler is preferably 0.1 to 200 parts by weight with respect to 100 parts by weight of the total amount of the polymethylpentene resin and the liquid crystal polymer. , More preferably 1 to 100 parts by weight, still more preferably 5 to 50 parts by weight.

In addition to the polymethylpentene resin and the liquid crystal polymer, the polymethylpentene resin composition of the present invention may further contain other resin components and additives as long as the object of the present invention is not impaired. Other resin components include, for example, polyamide, polyester, polyacetal, polyphenylene ether, and modified products thereof, thermoplastic resins such as polysulfone, polyethersulfone, polyetherimide, and polyamideimide, and phenol resins, epoxy resins, and polyimide resins. Examples thereof include thermocurable resins such as. Examples of the additive include a colorant, a flame retardant, an antistatic agent and the like.

The other resin components and additives can be blended alone or in combination of two or more.

When other resin components are blended, the blending amount of the resin component is preferably 0.1 to 100 parts by weight, preferably 0.1 to 100 parts by weight, based on 100 parts by weight of the total amount of the polymethylpentene resin and the liquid crystal polymer. More preferably, it is 80 parts by weight.

When an additive is blended, the blending amount of the additive is preferably 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total amount of the polymethylpentene resin and the liquid crystal polymer. It is more preferable that it is a part.

The polymethylpentene resin composition of the present invention kneads the above-mentioned polymethylpentene resin and liquid crystal polymer together with the above-mentioned compatibilizer, inorganic filler and / or organic filler, other resin components, and additives, if necessary. It can be manufactured by melting and kneading with a machine. Melt kneading can be performed well under conventional blending conditions. The compatibilizer, inorganic filler and / or organic filler, other resin components and additives may be pre-blended into either the polymethylpentene resin or the liquid crystal polymer, or the polymethylpentene resin composition may be formulated. It may be blended at the time of molding.

As the kneader, a Banbury mixer, a kneader, a single-screw or twin-screw extruder, or the like is used. For example, when a twin-screw extruder is used, kneading may be performed while the vent port is evacuated, but the kneading is not limited to this, and kneading may be performed in an inert gas atmosphere.

The polymethylpentene resin composition of the present invention can be used in containers, sheets, films, pipes, tubes, bottles, fibers and the like by known molding methods such as injection molding, blow molding, press molding, uniaxial stretching, biaxial stretching and inflation. Is processed into. Since the polymethylpentene resin composition of the present invention has excellent fluidity, it is particularly preferably molded by injection molding.

Molded products such as containers, sheets, films, pipes, tubes, bottles, and fibers obtained by molding the polymethylpentene resin composition of the present invention by these methods exhibit excellent heat resistance and light weight. is there.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited thereto.

The characteristic values in the examples were measured by the following methods.
<Crystal melting temperature>
After measuring the endothermic peak temperature (Tm1) observed when the sample is measured at a temperature rising condition of 20 ° C./min from room temperature using a differential scanning calorimeter (Exstar6000 manufactured by Seiko Instruments Co., Ltd.), it is 50 from Tm1. Hold at high temperature for 10 minutes. Next, the sample was cooled to room temperature under the temperature lowering condition of 20 ° C./min, and the endothermic peak when measured again under the temperature rising condition of 20 ° C./min was observed, and the temperature indicating the peak top was the crystal melting temperature (Tm). ).

<Liquidity (liquidity)>
Molded with an injection molding machine (UH1000-110 manufactured by Nissei Resin Industry Co., Ltd.) at a cylinder temperature of 300 ° C. and an injection pressure of 75 MPa using a barflow flow length measuring die having a thickness of 0.5 mm and a width of 12.7 mm. It was evaluated by the flow length at that time.

<Melting viscosity>
The melt viscosity was measured at 300 ° C. using a 0.7 mmφ × 10 mm capillary rheometer using a melt viscosity measuring device (Capillary Graph 1D manufactured by Toyo Seiki Co., Ltd.).

<Deflection temperature under load>
Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), a strip-shaped test piece (length 127 mm × width 12.) was used at a crystal melting temperature of + 20 to 40 ° C. and a mold temperature of 70 ° C. 7 mm x 3.2 mm thick) was injection molded, and using this, the temperature at which a predetermined deflection amount (0.254 mm) was measured at a load of 0.46 MPa and a heating rate of 2 ° C./min was measured in accordance with ASTM D648. ..

<specific gravity>
Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), a disk-shaped test piece (diameter 50 mm x thickness 3 mm) was used at a cylinder temperature of + 20 to 40 ° C. ) Was injection molded and measured according to ASTM D792 using this.

<Tensile strength and tensile modulus>
Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), a dumbbell-shaped tensile test piece (length 115 mm x width 6 mm) was used at a cylinder temperature of + 20 to 40 ° C. × Thickness 3.2 mm) was injection molded. The measurement was performed using an INSTRON 5567 (universal testing machine manufactured by Instron Japan Company Limited) in accordance with ASTM D638, with a chuck-to-chuck distance of 64.0 mm and a tensile speed of 5 mm / min.

<Bending strength and flexural modulus>
Under the same conditions as the molded piece used for measuring the tensile strength and tensile elastic modulus, a strip-shaped bending test piece (length 127 mm × width 12.7 mm × thickness 3.2 mm) was injection-molded. The bending test was performed using an INSTRON5567 (universal testing machine manufactured by Instron Japan Company Limited) at a distance between spans of 50.0 mm and a compression speed of 1.3 mm / min in accordance with ASTM D790.

In the examples, the abbreviations below represent the following compounds.
PMP: Polymethylpentene LCP: Liquid crystal polyester POB: 4-Hydroxybenzoic acid
BON6: 6-Hydroxy-2-naphthoic acid HQ: Hydroquinone BP: 4,4'-biphenol TPA: Terephthalic acid

(Polymethylpentene resin)
In the examples, the following were used as the polymethylpentene resin.
PMP: TPX (MX004) manufactured by Mitsui Chemicals, Inc.

Hereinafter, an example of synthesizing LCP will be described [Synthesis Example 1 (LCP1)].
POB and BON6 were charged in a 2 L reaction vessel equipped with a stirrer with a torque meter and a distilling tube so as to have a total amount of 6.5 mol in the composition ratio shown in Table 1, with respect to the amount of hydroxyl groups (mol) of all the monomers. In addition, 1.03 times the molar amount of acetic anhydride was charged, and deacetic acid polymerization was carried out under the following conditions.

The polymerization was carried out in a nitrogen gas atmosphere from room temperature to 150 ° C. in 1 hour and maintained at the same temperature for 30 minutes. Next, the temperature was rapidly raised to 210 ° C. while distilling off acetic acid produced as a by-product, and the temperature was maintained at the same temperature for 30 minutes. Then, the temperature was raised to 325 ° C. over 5 hours, and then the pressure was reduced to 20 mmHg over 90 minutes. When a predetermined torque was exhibited, the polymerization reaction was terminated, the contents of the reaction vessel were taken out, and pellets of liquid crystal polyester were obtained by a pulverizer. The amount of distillate acetic acid at the time of polymerization was almost the same as the theoretical value. The crystal melting temperature measured by DSC of the obtained pellet was 278 ° C.

[Synthesis Example 2 (LCP2)]
In a 2 L reaction vessel equipped with a stirrer with a torque meter and a distillate, POB, BON6, HQ, BP and TPA were charged in a composition ratio shown in Table 2 so as to have a total amount of 6.5 mol, and all the monomers were further charged. Acetic anhydride was charged 1.03 times by mole with respect to the amount of hydroxyl groups (molar), and deacetic acid polymerization was carried out under the following conditions.

The temperature was raised from room temperature to 150 ° C. in a nitrogen gas atmosphere in 1 hour, and the temperature was maintained at the same temperature for 30 minutes. Then, the temperature was raised to 350 ° C. over 7 hours while distilling off the acetic acid produced as a by-product, and then the pressure was reduced to 5 mmHg over 80 minutes. When a predetermined torque was exhibited, the polymerization reaction was terminated, the contents of the reaction vessel were taken out, and pellets of liquid crystal polyester resin were obtained by a pulverizer. The amount of distillate acetic acid at the time of polymerization was almost the same as the theoretical value. The crystal melting temperature (Tm) of the obtained pellets was 341 ° C.

[Example 1]
Polymethylpentene and LCP1 are blended so as to have the weight ratios shown in Table 3, and melt-kneaded at 300 ° C. using a twin-screw extruder TEX-30 (manufactured by Japan Steel Works, Ltd.), and LCP. Pellets of the polymethylpentene resin composition in which the mixture was uniformly dispersed were obtained. Then, the fluidity, melt viscosity, deflection temperature under load, specific gravity, tensile strength, tensile elastic modulus, bending strength and bending elastic modulus were measured.

[Reference Examples 1 and 2]
The fluidity, melt viscosity, deflection temperature under load, specific gravity, tensile strength, tensile elastic modulus, bending strength and flexural modulus were measured independently of the polymethylpentene resin and LCP1 in the same manner as in Example 1. The results are shown in Table 3.

[Examples 2 to 3 and Comparative Example 1]
Pellets of the polymethylpentene resin composition were prepared in the same manner as in Example 1 except that the polymethylpentene resin and LCP1 were changed to the ratios shown in Table 3, and the fluidity, melt viscosity, deflection temperature under load, and specific gravity were prepared. , Tensile strength, tensile elastic modulus, bending strength and bending elastic modulus were measured. The results are shown in Table 3.

[Comparative Example 2]
Polymethylpentene and LCP2 were blended so as to have the weight ratios shown in Table 3, and melt-kneading was attempted at 355 ° C. using a twin-screw extruder TEX-30 (manufactured by Japan Steel Works, Ltd.). Since a large amount of gas was generated due to the decomposition of PMP immediately after the start of kneading, the melt kneading was stopped.

As is clear from Table 3, the polymethylpentene resin compositions according to the present invention of Examples 1 to 3 have improved heat resistance and fluidity as compared with a single polymethylpentene resin, and further. The specific gravity was ^{as low as 1.00 g / cm 3} or less, and the weight was excellent.

On the other hand, the polymethylpentene resin composition of Comparative Example 1 containing an excess amount of LCP had a high specific gravity and was inferior in lightness.

〔３〕液晶ポリマーが、式[Ｉ]で表される繰返し単位を全繰返し単位中２０モル％以上含む液晶ポリエステルである、〔１〕または〔２〕に記載のポリメチルペンテン樹脂組成物。

〔４〕液晶ポリマーが、式[Ｉ]および式［ＩＩ］で表される繰返し単位から構成される液晶ポリエステルである、〔１〕〜〔３〕の何れかに記載のポリメチルペンテン樹脂組成物。

〔５〕比重が１．００ｇ／ｃｍ ^３ 以下である、〔１〕〜〔４〕の何れかに記載のポリメチルペンテン樹脂組成物。
〔６〕〔１〕〜〔５〕の何れかに記載のポリメチルペンテン樹脂組成物から構成される成形品。
Further, in Comparative Example 2 in which LCP2 having a crystal melting temperature of more than 300 ° C. was blended, melt-kneading was extremely difficult, and a polymethylpentene resin composition could not be obtained.
Preferred embodiments of the present invention include:
[1] A polymethylpentene resin composition containing 0.1 to 100 parts by weight of a liquid crystal polymer having a crystal melting temperature of 300 ° C. or lower with respect to 100 parts by weight of the polymethylpentene resin.
[2] The polymethylpentene resin composition according to [1], wherein the liquid crystal polymer is a liquid crystal polyester containing a repeating unit represented by the formulas [I] and [II].

[3] The polymethylpentene resin composition according to [1] or [2], wherein the liquid crystal polymer is a liquid crystal polyester containing 20 mol% or more of the repeating units represented by the formula [I] in all the repeating units.

[4] The polymethylpentene resin composition according to any one of [1] to [3], wherein the liquid crystal polymer is a liquid crystal polyester composed of repeating units represented by the formulas [I] and [II]. ..

[5] The polymethylpentene resin composition according to any one of [1] to [4], which has a specific gravity of 1.00 g / cm ^{3 or less.}
[6] A molded product composed of the polymethylpentene resin composition according to any one of [1] to [5].

Claims (5)

For 100 parts by weight of the polymethylpentene resin, 0.1 to 70 parts by weight of a liquid crystal polymer having a crystal melting temperature of 300 ° C. or lower is contained, and the liquid crystal polymer is of the formula [I].

The repeating unit represented by, and the formula [II].

A polymethylpentene resin composition which is a liquid crystal polyester containing a repeating unit represented by. The polymethylpentene resin composition according to claim 1, wherein the liquid crystal polymer is a liquid crystal polyester containing 20 mol% or more of the repeating units represented by the formula [I] in all the repeating units.

The polymethylpentene according to claim 1 or 2, wherein the liquid crystal polymer is a liquid crystal polyester containing 90 mol% or more of the repeating unit represented by the formula [I] and the repeating unit represented by the formula [II] in a total amount. Resin composition.

The polymethylpentene resin composition according to any one of claims 1 to 3, which has a specific gravity of 1.00 g / cm ^{3 or less.} A molded product composed of the polymethylpentene resin composition according to any one of claims 1 to 4.