JP6895859B2 - Polypropylene resin composition - Google Patents

Description

The present invention relates to a polypropylene resin composition having excellent molding processability, mechanical properties, heat resistance and dimensional stability, and a molded product composed of the polypropylene resin composition.

Molded products obtained by injection molding a polypropylene resin composition are widely used in electrical / electronic parts, building parts, machine parts, daily necessities, etc. from the viewpoints of weight reduction and cost performance.

However, due to the recent complication of design and the demand for further weight reduction, the machine can improve the formability (especially the fluidity of the resin material) and secure the required strength even if the material is thin. Physical properties (rigidity and impact strength) and heat resistance are required. Further, from the viewpoint of designability, dimensional stability (low coefficient of linear expansion) is required.

Therefore, a resin composition in which a polypropylene-based resin contains a specific talc has been proposed (Patent Document 1). However, the resin composition proposed in Patent Document 1 has insufficient fluidity and is also inferior in rigidity.

Further, Patent Document 2 proposes a resin molded product obtained by melt-kneading a polypropylene-based resin and a thermoplastic liquid crystal resin obtained by adding a semi-aromatic polyester to a fully aromatic polyester. However, the melting point of the total aromatic polyester is as high as 260 ° C., and when melt-kneaded under high temperature conditions, the polypropylene-based resin deteriorates, and there is a problem that it becomes difficult to obtain impact strength and heat resistance of the molded product.

Japanese Unexamined Patent Publication No. 9-08747 Japanese Unexamined Patent Publication No. 2002-241550

The present invention is intended to solve the above problems, and provides a polypropylene resin composition excellent in molding processability, mechanical strength, heat resistance and dimensional stability, and a molded product composed of the polypropylene resin composition. The purpose is to do.

As a result of diligent studies on improving the physical properties of polypropylene resin, the present inventors have obtained a polypropylene resin composition having excellent moldability, mechanical strength and heat resistance by incorporating a specific total aromatic liquid crystal polymer into the polypropylene resin. We have found that it can be obtained and have completed the present invention.

［式中、
Ａｒ _１ およびＡｒ _２ は、それぞれ１種または２種以上の２価の芳香族基を表し、ｐ、ｑ、ｒおよびｓは、それぞれ、全芳香族液晶ポリエステル中での各繰返し単位の組成比（モル％）であり、以下の条件を満たすものである：
０．５≦ｐ／ｑ≦２．５
２≦ｒ≦１５、および
２≦ｓ≦１５］
で表される繰返し単位を含む全芳香族液晶ポリエステルである、〔１〕〜〔３〕のいずれかに記載のポリプロピレン樹脂組成物。
〔５〕Ａｒ _１ およびＡｒ _２ が、互いに独立して、式（１）〜（４）
［化２］

で表される芳香族基からなる群から選択される１種または２種以上を含む、〔４〕に記載のポリプロピレン樹脂組成物。
〔６〕ポリプロピレン樹脂組成物が、ポリプロピレン樹脂１００質量部に対して、無機充填材１〜１５０質量部を含有する、〔１〕〜〔５〕のいずれかに記載のポリプロピレン樹脂組成物。
〔７〕〔１〕〜〔６〕のいずれかに記載のポリプロピレン樹脂組成物から構成される成形品。 That is, the present invention contains 10 to 500 parts by mass of a total aromatic liquid crystal polymer having a crystal melting temperature of less than 260 ° C. with respect to 100 parts by mass of polypropylene resin, and has a melt volume flow rate (ISO 1133, 230 ° C., load of 2160 g). ^{) Is 3} to 100 cm 3/10 minutes, the bending elasticity (ISO-178) is 2.0 GPa or more, and the Charpy impact strength (ISO-179) is 3.0 kJ / m ² or more. Provided is a molded product composed of a resin composition.
Preferred embodiments of the present invention include:
[1] A polypropylene resin composition containing 10 to 500 parts by mass of a total aromatic liquid crystal polymer having a crystal melting temperature of less than 260 ° C. with respect to 100 parts by mass of the polypropylene resin.
Melt volume flow rate (ISO 1133,230 ℃, load 2160 g) is 3~100cm ^3/10 min,
Flexural modulus (ISO-178) is 2.0 GPa or more, and
Charpy impact strength (ISO-179) is 3.0 kJ / m ² or more
Is a polypropylene resin composition.
[2] The polypropylene resin composition according to [1], wherein the deflection temperature under load (ISO-75, load 0.46 MPa) is 100 ° C. or higher.
[3] The polypropylene resin composition according to [1] or [2], wherein the polypropylene resin is block polypropylene.
[4] All aromatic liquid crystal polymers are represented by formulas (I) to (IV).
[Chemical 1]

[During the ceremony,
Ar ₁ and Ar ₂ represent one or more divalent aromatic groups, respectively, and p, q, r and s are the composition ratios of each repeating unit in the total aromatic liquid crystal polyester (respectively). Mol%), which meets the following conditions:
0.5 ≤ p / q ≤ 2.5
2 ≦ r ≦ 15, and
2 ≦ s ≦ 15]
The polypropylene resin composition according to any one of [1] to [3], which is a totally aromatic liquid crystal polyester containing a repeating unit represented by.
[5] Ar ₁ and Ar ₂ are independent of each other and have equations (1) to (4).
[Chemical 2]

The polypropylene resin composition according to [4], which comprises one or more selected from the group consisting of aromatic groups represented by.
[6] The polypropylene resin composition according to any one of [1] to [5], wherein the polypropylene resin composition contains 1 to 150 parts by mass of an inorganic filler with respect to 100 parts by mass of the polypropylene resin.
[7] A molded product composed of the polypropylene resin composition according to any one of [1] to [6].

According to the present invention, it is possible to obtain a polypropylene resin composition and a molded product having excellent molding processability by injection molding and the like, and excellent mechanical strength, heat resistance and dimensional stability.

Hereinafter, the present invention will be specifically described.

The polypropylene resin composition of the present invention contains a polypropylene resin and a totally aromatic liquid crystal polymer as essential components.

The polypropylene resin used in the present invention includes a propylene homopolymer, a propylene-olefin copolymer (for example, a copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms), block polypropylene, or a blend thereof. Examples include resin.
Among these, block polypropylene is preferable from the viewpoint that mechanical strength can be easily obtained.

Examples of the olefin used for copolymerization with propylene in the propylene-olefin copolymer include ethylene and α-olefins having 4 to 20 carbon atoms, for example, 1-butene, 1-pentene, 4-methyl-1-pentene, and the like. Examples thereof include 1-hexene, 4-methyl-1-hexene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-octadecene, 1-eicosene and the like. These can be used alone or in combination of two or more.
Of these, ethylene and α-olefins having 4 to 10 carbon atoms are preferable.

The content of the repeating unit derived from the α-olefin is preferably 20 mol% or less, more preferably 10 mol% or less in the polypropylene resin.

Examples of the propylene-olefin copolymer include a random copolymer, a block copolymer, a random block copolymer and the like.

Block polypropylene is a resin composed of a crystalline propylene polymer as a main component, a random copolymer elastomer as a copolymer component, and an ethylene polymer as an optional component.

Examples of the propylene polymer in the block polypropylene include a propylene homopolymer or a crystalline random copolymer (for example, a copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms), and have heat resistance. From this point of view, it is preferably a propylene homopolymer.

Examples of the random copolymer elastomer in the block polypropylene include an ethylene-propylene copolymer and a propylene-ethylene-α-olefin (for example, 4 to 20 carbon atoms) copolymer, and the ethylene-propylene copolymer weight. Combined elastomers are preferred.

Examples of the ethylene polymer in the block polypropylene include an ethylene homopolymer or a crystalline random copolymer (for example, a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms), and the ethylene homopolymer. Is preferable.

The normal temperature xylene-soluble component in the block polypropylene is preferably 1 to 50% by mass, more preferably 2 to 30% by mass, and further preferably 3 to 20% by mass.

When the room temperature xylene soluble content is less than 1% by mass, the dispersibility and impact strength of the total aromatic liquid crystal polymer tend to be insufficient in the obtained polypropylene resin composition, and when it exceeds 50% by mass, the polypropylene resin The rigidity and heat resistance of the composition tend to decrease.

The room temperature xylene-soluble component is measured as follows. First, 2.5 g of block polypropylene is dissolved in 250 ml of xylene at 135 ° C. with stirring. After 20 minutes, the solution is cooled to 25 ° C. with stirring, then settled for 30 minutes, then the precipitate is filtered, the filtrate is evaporated under a nitrogen stream and the residue is vacuum dried at 80 ° C. until constant volume is reached. .. Then, the dried residue is weighed to determine the mass% of the xylene-soluble component at 25 ° C.

Melt volume flow rate of the polypropylene resin used in the present invention (MVR) is preferably a 1 to 100 cm ^3/10 min, more preferably from 2~80cm ^3/10 min, 3~60cm ^3/10 min Is more preferable.

Here, MVR is a value measured under a 2.16 kg load under a temperature condition of 230 ° C. in accordance with ISO 1133.

When MVR of the polypropylene resin is less than ^{1 cm} 3/10 min, it decreases the fluidity of the polypropylene resin composition obtained, and when it exceeds 100 cm ^3/10 min, a bending tendency modulus, impact strength and heat resistance is lowered There is.

As a method for producing the polypropylene resin used in the present invention, a method of homopolymerizing propylene using a Ziegler-Natta type catalyst or a metallocene catalyst, or an olefin other than propylene (for example, ethylene and α- with 4 or more carbon atoms) Examples thereof include a method of copolymerizing one or more kinds of olefins selected from (olefins) with propylene. Examples of the Ziegler-Natta type catalyst include a catalyst system in which a titanium-containing solid transition metal component and an organometallic component are used in combination. Examples of the metallocene catalyst include a catalyst system in which a transition metal compound of Group 4 to Group 6 of the periodic table having at least one cyclopentadienyl skeleton and a co-catalyst component are used in combination.

Further, as the polymerization method, for example, a slurry polymerization method or a solution polymerization method carried out in an inert hydrocarbon solvent, a liquid phase polymerization method or a gas phase polymerization method carried out in the absence of a solvent, and a continuous method thereof. Examples thereof include a gas phase-gas phase polymerization method and a liquid phase-gas phase polymerization method to be carried out, and these polymerization methods may be a batch method or a continuous method. Further, the polypropylene resin may be produced in one step, or may be a multi-step polymerization method in which two or more steps are produced under different conditions. These polymerization methods can be applied to both homopolymerization of propylene and copolymerization of propylene and olefin.

The method for producing block polypropylene in the present invention may be either a batch method or a continuous method, and generally, a method for first producing a propylene polymer as a main component and then producing a copolymer component. Is used.

For example, in the case of continuous production, hydrogen gas as a molecular weight modifier and a catalyst are supplied to the raw material propylene gas in the polymerization tank in the first stage, and the polymerization amount is controlled by the polymerization time to produce a propylene homopolymer, and then in the second stage. After moving to a polymerization tank, hydrogen gas such as raw material propylene gas or ethylene gas and, if necessary, a catalyst are added to produce a copolymer (random copolymer elastomer, ethylene polymer, etc.) to produce block polypropylene. Obtainable.

In such a multi-stage polymerization method, since the resin components produced at each stage are blended in the polymerization reaction vessel at the time of polymerization, the resin components in the main component propylene polymer are compared with the method in which each resin component is melt-kneaded by an extruder. The dispersion of the copolymer (random copolymer elastomer, ethylene polymer, etc.) in the above becomes fine.

The block polypropylene can be produced by the multi-stage polymerization method as described above, but is not limited to this, and may be a blended resin obtained by melt-kneading each of the above polymers.

The polypropylene resin may further contain at least one selected from the group consisting of ethylene-propylene-diene rubber (EPDM), vinyl resins, diene rubbers and thermoplastic elastomers.

The ethylene-propylene-diene rubber (EPDM) is not particularly limited, and examples thereof include ethylene-propylene-ethylidene norbornene rubber, ethylene-propylene-1,4-hexadiene rubber, and ethylene-propylene-dicyclopentadiene rubber. These may be used alone or in combination of two or more.

The vinyl-based resin is not particularly limited, and is, for example, an ethylene-vinyl acetate copolymer, a (meth) acrylic resin ((meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, and (. (Meta) (co) polymer of one or more monomers selected from 2-ethylhexyl acrylate, etc.) and styrene resin (polystyrene, AS resin, ABS resin, styrene-butadiene resin, styrene-maleic anhydride). Resins, styrene-acrylic acid ester resins, HIPS, etc.) and the like. These may be used alone or in combination of two or more.

The diene rubber is not particularly limited, and examples thereof include butadiene rubber, butyl rubber, chloroprene rubber, isoprene rubber, and nitrile rubber (acrylonitrile-butadiene copolymer and the like). These may be used alone or in combination of two or more.

The thermoplastic elastomer is not particularly limited, but for example, styrene-butadiene block copolymer, styrene-butadiene-styrene triblock copolymer, styrene-ethylene-butadiene-styrene block copolymer, styrene-isoprene-styrene block. Copolymers, styrene-isoprene rubber, styrene-ethylene-propylene-styrene block copolymers, polystyrene-poly (ethylene / butylene) block copolymers, polystyrene-poly (ethylene / propylene) block copolymers, styrene-ethylene Examples thereof include -butylene-ethylene block copolymers and derivatives obtained by hydrogenating them. These may be used alone or in combination of two or more.

The total aromatic liquid crystal polymer used in the present invention is a total aromatic liquid crystal polyester or a total aromatic liquid crystal polyester amide that forms an anisotropic molten phase, which is called a thermotropic liquid crystal polymer by those skilled in the art.

The properties of the anisotropic molten phase of the total aromatic liquid crystal polymer can be confirmed by a usual deflection test method using an orthogonal deflector, that is, by observing a sample placed on a hot stage in a nitrogen atmosphere.

The repeating unit constituting the total aromatic liquid crystal polymer used in the present invention includes an aromatic oxycarbonyl repeating unit, an aromatic dicarbonyl repeating unit, an aromatic dioxy repeating unit, an aromatic aminooxy repeating unit, and an aromatic diamino repeating unit. , Aromatic aminocarbonyl repeating units and combinations thereof.

Specific examples of the monomer giving the aromatic oxycarbonyl repeating unit include, for example, 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, and 6-hydroxy-2, which are aromatic hydroxycarboxylic acids. -Naftoeic acid, 5-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl- Examples thereof include 3-benzoic acid and the like, and alkyl, alkoxy or halogen substituents thereof, and ester-forming derivatives such as acylated products, ester derivatives and acid halides thereof. Among these, 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are easy to adjust the mechanical characteristics, heat resistance, crystal melting temperature, and moldability of the obtained total aromatic liquid crystal polymer to appropriate levels. preferable.

Specific examples of the monomer giving an aromatic dicarbonyl repeating unit include, for example, aromatic dicarboxylic acids terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, and 2,7. -Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, etc., and their alkyl, alkoxy or halogen substituents, and ester-forming derivatives such as their ester derivatives, acid halides, etc. 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 total aromatic liquid crystal polymer can be easily adjusted to appropriate levels.

Specific examples of the monomer giving an aromatic dioxy repeating unit include, for example, aromatic diols hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1, 4-Dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether and the like, and their alkyl, alkoxy or halogen substituents, In addition, ester-forming derivatives such as these acylated products can be mentioned. Among these, hydroquinone and 4,4'-dihydroxybiphenyl can easily adjust the reactivity at the time of polymerization, the mechanical properties of the obtained total aromatic liquid crystal polymer, heat resistance, crystal melting temperature, and moldability to appropriate levels. Is preferable.

Examples of the monomer giving the aromatic aminooxy repeating unit, the aromatic diamino repeating unit and the aromatic aminocarbonyl repeating unit include aromatic hydroxyamine, aromatic diamine and aromatic aminocarboxylic acid.

The total aromatic liquid crystal polymer used in the present invention contains an aromatic oxydicarbonyl repeating unit, an aliphatic dihydroxy repeating unit, an aliphatic dicarbonyl repeating unit and a thioester bond as long as the object of the present invention is not impaired. May be good. Examples of the monomer that imparts a thioester bond include mercapto aromatic carboxylic acid, aromatic dithiol, and hydroxyaromatic thiol. The amount of these monomers used is divided into aromatic oxycarbonyl repeating units, aromatic dicarbonyl repeating units, aromatic dioxy repeating units, aromatic aminooxy repeating units, aromatic diamino repeating units and aromatic aminocarbonyl repeating units. It is preferably 10 mol% or less based on the total amount of the given monomers.

Some copolymers combining these repeating units may or may not form an anisotropic molten phase depending on the composition and composition ratio of the monomers and the sequence distribution of each repeating unit in the copolymer. Although present, the total aromatic liquid crystal polymer used in the present invention is limited to copolymers that form an anisotropic molten phase.

The total aromatic liquid crystal polymer used in the present invention may be a blend of two or more kinds of total aromatic liquid crystal polymers.

The crystal melting temperature measured by the differential scanning calorimetry of the total aromatic liquid crystal polymer used in the present invention is less than 260 ° C., preferably 250 ° C. or lower, more preferably 235 ° C. or lower, still more preferably 225. It is below ° C. The total aromatic liquid crystal polymer used in the present invention has a crystal melting temperature measured by a differential scanning calorimeter of preferably 150 ° C. or higher, more preferably 170 ° C. or higher, still more preferably 180 ° C. or higher.

When the crystal melting temperature of the total aromatic liquid crystal polymer is less than 260 ° C., the total aromatic liquid crystal polymer is easily dispersed in the polypropylene resin as a matrix in a fibrous state, which is an object of the present invention when molding. It becomes easy to obtain excellent mechanical properties and heat resistance.

In the present specification and claims, "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). It is obtained from the peak temperature. More specifically, after observing the heat absorption peak temperature (Tm1) observed when a sample of a total aromatic liquid crystal polymer is measured at a temperature rising condition of 20 ° C./min from room temperature, it is 20 to 50 ° C. higher than Tm1. After holding the sample at a temperature for 10 minutes and then cooling the sample to room temperature under a temperature decrease condition of 20 ° C./min, the heat absorption peak when measured again under a temperature rise condition of 20 ° C./min is observed, and the peak top is shown. Let the temperature be the crystal melting temperature of the total aromatic liquid crystal polymer. As the measuring device, for example, Exstar6000 manufactured by Seiko Instruments Inc. can be used.

The melt viscosity of the total aromatic liquid crystal polymer used in the present invention (measured with a capillary rheometer, crystal melting temperature + 40 ° C., 1000s ^-1 ) is preferably 1 to 200 Pa · s, more preferably 5 to 100 Pa · s.

If the melt viscosity is less than 1 Pa · s, it tends to be difficult to disperse uniformly in the fiber state, and if it exceeds 200 Pa · s, it also tends to be difficult to disperse uniformly in the fiber state.

As the total aromatic liquid crystal polymer used in the present invention, a total aromatic liquid crystal polyester is preferably used, and a total aromatic liquid crystal polyester containing a repeating unit represented by the formulas (I) to (IV) is more preferably used. To.

[During the ceremony,
Ar ₁ and Ar ₂ represent one or more divalent aromatic groups, respectively, and p, q, r and s are the composition ratios of each repeating unit in the total aromatic liquid crystal polyester (respectively). Mol%), which meets the following conditions:
0.5 ≤ p / q ≤ 2.5
2 ≦ r ≦ 15, and 2 ≦ s ≦ 15. ]

The molar ratio (p / q) of the composition ratio p (mol%) according to the above formula (I) and the composition ratio q (mol%) according to the formula (II) is more preferably 0.6 to 1.8, and is 0. .8 to 1.6 is more preferable.

With respect to the above-mentioned preferably used total aromatic liquid crystal polyester, the total composition ratio of p and q is preferably 70 to 96 mol%, more preferably 76 to 90 mol%.

With respect to the above-mentioned preferably used total aromatic liquid crystal polyester, the composition ratio p according to the formula (I) and the composition ratio q according to the formula (II) are preferably 32 to 54 mol%, respectively, and 36 to 52 mol%, respectively. Is more preferable.

The total aromatic liquid crystal polyester preferably used in the present invention has a repeating unit represented by the formulas (I) and (II) as at least the above molar ratio (p / q) and optionally the above p. A crystal melting temperature of less than 260 ° C. is indicated by inclusion in the total composition ratio of q and / or the respective composition ratios of p and q (mol%).

Further, with respect to the total aromatic liquid crystal polyester preferably used in the present invention, the composition ratio r according to the formula (III) and the composition ratio s according to the formula (IV) are preferably 2 to 15 mol%, respectively, and 5 to 5 12 mol% is more preferred. r and s are preferably equimolar quantities.

In the above repeating unit, for example, when Ar ₁ (or Ar ₂ ) represents two or more divalent aromatic groups, the repeating unit represented by the formula (III) (or (IV)) is a total aromatic group. It means that two or more kinds are contained in the liquid crystal polyester depending on the kind of divalent aromatic group. In this case, the composition ratio r according to the formula (III) (or the composition ratio s according to the formula (IV)) represents the composition ratio obtained by summing up two or more repeating units.

Specific examples of the monomer giving the repeating unit represented by the formula (I) include 4-hydroxybenzoic acid and an ester-forming derivative such as an acylated product thereof, an ester derivative or an acid halide.

Specific examples of the monomer giving the repeating unit represented by the formula (II) include 6-hydroxy-2-naphthoic acid and an ester-forming derivative such as an acylated product, an ester derivative, or an acid halide. Be done.

Specific examples of the monomer giving the repeating unit represented by the formula (III) include terephthalic acid and isophthalic acid, which are aromatic dicarboxylic acids, 2,6-naphthalenedicarboxylic acid, and 1,6-naphthalenedicarboxylic acid. , 2,7-Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl and the like, and their alkyl, alkoxy or halogen substituents, and esters such as their ester derivatives and acid halides. Examples include forming derivatives.

Specific examples of the monomer giving the repeating unit represented by the formula (IV) include, for example, aromatic diols hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 1,6-. Dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether, etc., and their alkyl, alkoxy Alternatively, halogen-substituted products and ester-forming derivatives such as these acylated products can be mentioned.

Further, among all aromatic liquid crystal polyesters preferably used in the present invention, Ar ₁ and Ar _{2 according} to the repeating unit represented by the formulas (III) and (IV) are independently of the formula (3). All aromatic liquid crystal polyesters containing one or more selected from the group consisting of aromatic groups represented by 1) to (4) are more preferably used.

Among these, the aromatic group represented by the formulas (1) and (4) is used as the repeating unit represented by the formula (III), that is, the monomer giving these repeating units is terephthalic acid. And 2,6-naphthalenedicarboxylic acids and their ester-forming derivatives are particularly preferable because they can easily adjust the mechanical properties, heat resistance, crystal melting temperature and molding processability of the obtained total aromatic liquid crystal polyester to appropriate levels. ..

Further, as the repeating unit represented by the formula (IV), the aromatic groups represented by the formulas (1) and (3) are used, that is, the monomers giving these repeating units are hydroquinone and 4, 4'-dihydroxybiphenyl and these ester-forming derivatives can easily adjust the reactivity at the time of polymerization and the mechanical properties, heat resistance, crystal melting temperature and molding processability of the obtained total aromatic liquid crystal polyester to an appropriate level. Is particularly preferable.

In the above repeating unit, for example, when Ar ₁ (or Ar ₂ ) contains two or more kinds of aromatic groups, the repeating unit represented by the formula (III) (or (IV)) is in the total aromatic liquid crystal polyester. It means that two or more kinds are contained depending on the kind of divalent aromatic group. In this case, the composition ratio r according to the formula (III) (or the composition ratio s according to the formula (IV)) represents the composition ratio obtained by summing up two or more repeating units.

In the total aromatic liquid crystal polyester preferably used in the present invention, the total composition ratio of the repeating units [p + q + r + s] is preferably 100 mol%, but other repeating units may be used as long as the object of the present invention is not impaired. It may be further contained.

Examples of the monomer giving another repeating unit constituting the totally aromatic liquid crystal polyester preferably used in the present invention include other aromatic hydroxycarboxylic acids, aromatic hydroxyamines, aromatic diamines, and aromatic aminocarboxylic acids. , Aromatic hydroxydicarboxylic acid, aliphatic diol, aliphatic dicarboxylic acid, aromatic mercaptocarboxylic acid, aromatic dithiol, aromatic mercaptophenol and combinations thereof.

Specific examples of other aromatic hydroxycarboxylic acids include, for example, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 5-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl. -4-Hydroxybenzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid and its alkyl, alkoxy or halogen substituents, and their acylates, ester derivatives, acid halides. Examples thereof include ester-forming derivatives such as.

The total composition ratio of the repeating units given from these other monomer components is preferably 10 mol% or less in the entire repeating units.

Hereinafter, a method for producing the total aromatic liquid crystal polymer used in the present invention will be described.

The method for producing the total aromatic liquid crystal polymer used in the present invention is not particularly limited, and a known polycondensation method for forming an ester bond or an amide bond composed of the above-mentioned combination of monomers, for example, a molten acidlysis method or a slurry weight. Legal etc. can be used.

The melt acidlysis method is a preferred method for use in the method for producing a total aromatic liquid crystal polymer used in the present invention, in which the monomer is first heated to form a melt of the reactants. Then, the reaction is continued 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 all-aromatic liquid crystal polymer is a modified form in which a hydroxyl group and / or an amino group is acylated at room temperature. That is, it can also be subjected to the reaction as a lower acylated product. 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 in the reaction can be mentioned.

As the 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 is added to the monomer during the production of the total aromatic liquid crystal polymer to generate the monomer in the reaction system. You can also make it.

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 (dialkyltin oxide such as dibutyltin oxide, diaryltin oxide, etc.), organic titanium compounds (titanium dioxide, antimony trioxide, alkoxytitanium silicate, titanium alkoxide, etc.), and carboxylic acids. Examples include gaseous or alkaline earth metal salts (such as potassium acetate), inorganic acid salts (such as potassium sulfate), Lewis acids (such as boron trifluoride), and gaseous acid catalysts such as hydrogen halides (such as hydrogen chloride).

The ratio of the catalyst used is usually 1 to 1000 ppm, preferably 2 to 100 ppm, based on the total amount of the monomers.

The total aromatic liquid crystal polymer obtained by the polycondensation reaction in this manner is extracted from the polymerization reaction tank in a molten state and then processed into pellets, flakes, or powders.

The content of the total aromatic liquid crystal polymer in the polypropylene resin composition of the present invention is 10 to 500 parts by mass, preferably 13 to 450 parts by mass, more preferably 13 to 450 parts by mass of the total aromatic liquid crystal polymer with respect to 100 parts by mass of the polypropylene resin. It is 15 to 430 parts by mass, more preferably 20 to 400 parts by mass.

If the content of the total aromatic liquid crystal polymer is less than 10 parts by mass, the effect of improving fluidity, mechanical strength and heat resistance cannot be sufficiently obtained, and if it exceeds 500 parts by mass, the amount of bending is reduced and the flexibility is reduced. Tends to be compromised.

The polypropylene resin composition of the present invention can further contain a compatibilizer as an arbitrary component.

The compatibilizer refers to one that is localized at the interface of each resin phase constituting the blended resin composition, has a function of reducing the interfacial tension between the phases, and improving the compatibility.

The blending amount of the compatibilizer in the polypropylene resin composition is preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass with respect to 100 parts by mass of the polypropylene resin.

If the amount of the compatibilizer added is less than 0.5 parts by mass, the effect of improving compatibility is difficult to obtain, and if it exceeds 10 parts by mass, the thermal stability during molding tends to decrease.

Specific examples of the compatibilizer include maleic anhydride-grafted polyolefin-based copolymer, maleic anhydride-grafted polystyrene-based copolymer, vinyl monomer / maleic anhydride-based copolymer, and epoxy group-containing polyolefin-based copolymer. Examples thereof include epoxy group-containing vinyl-based random or graft or block copolymers, and carboxyl group-containing olefin-based random or graft copolymers.

Among these compatibilizers, a copolymer having at least one selected from the group consisting of an acid anhydride group, a carboxyl group, and an epoxy group is preferable, and a maleic anhydride-grafted polyolefin copolymer or an epoxy group is contained. A polyolefin-based copolymer is more preferable.

Specific examples of the maleic anhydride graft polyolefin-based copolymer include, for example, maleic anhydride graft polypropylene (PP-g-MAH), maleic anhydride graft ethylene / propylene rubber (EPR-g-MAH), and maleic anhydride graft. Ethylene / propylene / diene rubber (EPDM-g-MAH) and the like can be mentioned.

Specific examples of the maleic anhydride graft polystyrene-based copolymer include, for example, maleic anhydride graft polystyrene (PS-g-MAH), maleic anhydride graft styrene / butadiene / styrene copolymer (SBS-g-MAH), and the like. Maleic anhydride grafted styrene / ethylene / butene / styrene copolymer (SEBS-g-MAH) and the like can be mentioned.

Specific examples of the vinyl monomer / maleic anhydride copolymer include, for example, a styrene / maleic anhydride copolymer, a styrene / acrylic acid / maleic anhydride copolymer, and an acrylic acid ester / maleic anhydride copolymer. Can be mentioned.

Specific examples of the epoxy group-containing polyolefin-based copolymer include, for example, ethylene / glycidyl methacrylate copolymer, ethylene / glycidyl methacrylate / vinyl acetate copolymer, ethylene / glycidyl methacrylate / methyl acrylate copolymer, and ethylene / glycidyl. Polymethylmethacrylate graft copolymer to methacrylate / ethyl acrylate copolymer, polystyrene graft copolymer to ethylene / glycidyl methacrylate copolymer (EGMA-g-PS), polymethylmethacrylate graft copolymer to ethylene / glycidyl methacrylate copolymer (EGMA-) g-PMMA), a styrene / acrylonitrile graft copolymer to an ethylene / glycidyl methacrylate copolymer (EGMA-g-AS), and the like.

Specific examples of epoxy group-containing vinyl-based random or graft or block copolymers include, for example, glycidyl methacrylate graft polystyrene (PS-g-GMA), glycidyl methacrylate graft polymethyl methacrylate (PMMA-g-GMA), and glycidyl methacrylate graft. Examples thereof include polyacrylonitrile (PAN-g-GMA).

Specific examples of the carboxyl group-containing olefin-based random or graft copolymer include, for example, carboxylated polyethylene, carboxylated polypropylene, ethylene / methacrylic acid copolymer (ionomer), styrene / methacrylic acid copolymer, and styrene / acrylic acid. Examples include copolymers.

The compatibilizer may be used alone or in combination of two or more.

The polypropylene resin composition of the present invention may further contain an inorganic and / or organic filler as an optional component.

Specific examples of the inorganic and / or organic filler that the polypropylene resin composition of the present invention may contain include, for example, glass fiber, silica alumina fiber, alumina fiber, carbon fiber, potassium titanate fiber, and aluminum borate. Fibers, aramid fibers, polyarylate fibers, polybenzimidazole fibers, talc, mica, graphite, wollastonite, dolomite, clay, glass flakes, glass beads, glass balloons, calcium carbonate, barium sulfate, titanium oxide, etc. It may be used alone or in combination of two or more.
Among these, talc is preferable because it has an excellent balance between physical properties and cost.

Further, the inorganic and / or organic filler may be surface-treated. Examples of the surface treatment method include a method of adsorbing a surface treatment agent on the surface of the filler and a method of adding a surface treatment agent at the time of kneading.

Surface treatment agents include higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon-based lubricants, such as silane-based coupling agents, titanate-based coupling agents, and borane-based coupling agents, which are reactive coupling agents. Examples include surfactants.

When the inorganic and / or organic filler is blended, the content is preferably 1 to 150 parts by mass, preferably 10 to 100 parts by mass, based on 100 parts by mass of the total amount of the polypropylene resin and the total aromatic liquid crystal polymer. Is more preferable.

If the content of the inorganic and / or organic filler is less than 1 part by mass, it is difficult to obtain the effect of improving the mechanical strength and heat resistance of the polypropylene resin composition, and if it exceeds 150 parts by mass, the fluidity tends to decrease. ..

In addition to the polypropylene resin and the all-aromatic liquid crystal polymer, other additives and resin components may be added to the polypropylene resin composition of the present invention as long as the object of the present invention is not impaired.

Specific examples of other additives include, for example, higher fatty acids that are lubricants, higher fatty acid esters, higher fatty acid amides, higher fatty acid metal salts (here, higher fatty acids refer to those having 10 to 25 carbon atoms) and the like. , Mold release improver polysiloxane, fluororesin, colorant dye, pigment, carbon black, etc., flame retardant, antistatic agent, surfactant, nucleating agent talc, organic phosphate, sorbitol Examples thereof include anti-blocking agents, phosphorus-based antioxidants that are antioxidants, phenol-based antioxidants, sulfur-based antioxidants, and other weather-resistant agents, heat stabilizers, and neutralizing agents. These additives can be used alone or in combination of two or more.

The total amount of the other additives in the polypropylene resin composition is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the total amount of the polypropylene resin and the total aromatic liquid crystal polymer. It is a mass part.

If the total amount of the other additives is less than 0.01 parts by mass, it is difficult to realize the function of the additives, and if it exceeds 5 parts by mass, the thermal stability of the molding process of the polypropylene resin composition tends to deteriorate. is there.

Further, among the above other additives, when an additive such as a lubricant, a mold release agent, or an antiblocking agent is used, it may be added at the time of preparing a polypropylene resin composition, or at the time of molding. It may be attached to the pellet surface of the resin composition.

Specific examples of other resin components include thermoplastic resins such as polyamide, polyester, polyacetal, polyphenylene ether and its modified products, polysulfone, polyethersulfone, polyetherimide, polyamideimide, and thermocurable resins. Examples thereof include certain phenol resins, epoxy resins, and polyimide resins. These resin components may be used alone or in combination of two or more.

When other resin components are contained, the content thereof is preferably 0.1 to 100 parts by mass, preferably 0.1 to 80 parts by mass, based on 100 parts by mass of the total amount of the polypropylene resin and the total aromatic liquid crystal polymer. It is more preferable that it is a part.

The polypropylene resin composition of the present invention is a mixture of a polypropylene resin and a totally aromatic liquid crystal polymer, a compatibilizer, an inorganic and / or organic filler, other additives, and other resin components, and a Banbury mixer, a kneader, and the like. It can be obtained by melt-kneading the total aromatic liquid crystal polymer from the vicinity of the crystal melting temperature under the temperature condition of the crystal melting temperature + 40 ° C. using a uniaxial or biaxial extruder or the like.

Other resin components and other additives may be previously blended with either polypropylene resin or total aromatic liquid crystal polymer, or polypropylene obtained by melt-kneading polypropylene resin and total aromatic liquid crystal polymer. It may be blended when molding the resin composition.

The polypropylene resin composition of the present invention obtained in this way, melt volume flow rate conforming to ISO 1133 (230 ° C., load 2160 g) is, 3~100cm ^3/10 min, preferably 5~85cm ^3/10 min, more preferably 10~65cm ^3/10 min, more preferably a 15~60cm ^3/10 min, has the advantage that the fluidity is excellent.

The polypropylene resin composition of the present invention has an ISO-178-compliant flexural modulus (23 ° C.) of 2.0 GPa or more, preferably 2.0 to 30.0 GPa, more preferably 2 for a molded product composed of the same. It is .3 to 20.0 GPa, more preferably 2.5 to 15.0 GPa, and has an advantage of excellent rigidity.

The polypropylene resin composition of the present invention has an ISO-179-compliant Charpy impact strength (23 ° C.) of 3.0 kJ / m ² or more, preferably 5.0 to 100 kJ / m ² , for a molded product composed of the same. It is preferably 5.0 to 75 kJ / m ² , more preferably 5.5 to 50 kJ / m ² , and has an advantage of excellent impact resistance.

The polypropylene resin composition of the present invention has an ISO-75 deflection temperature under load (load 0.46 MPa), preferably 100 ° C. or higher, more preferably 100 to 250 ° C., still more preferably. The temperature is 110 to 225 ° C., more preferably 120 to 200 ° C., and has an advantage of excellent heat resistance.

The polypropylene resin composition of the present invention has a linear expansion coefficient of the flow direction (MD) of the molded product conforming to ASTM D696, preferably −1.0 × 10 ^{−5 to} 10.0 × for the molded product composed of the same. ^10-5 / ° C, more preferably −0.7 × ^{10-5 to} 8.0 × ^10-5 / ° C, even more preferably −0.5 × ^{10-5 to} 6.5 × ^10-5 / ° C, Even more preferably, it is −0.4 × 10 ^{−5 to} 5.0 × 10 ⁻⁵ / ° C., and has an advantage of excellent dimensional stability.

Further, since the polypropylene resin composition in the present invention has a low crystal melting temperature (less than 260 ° C.) of the total aromatic liquid crystal polymer, it easily melts and flows during molding, and the melt volume flow rate as described above even at a relatively low temperature. Is obtained.

Examples of the method for obtaining a molded product composed of the polypropylene resin composition of the present invention include known molding methods such as injection molding, extrusion molding, blow molding, compression molding and injection compression molding.

Among these, an injection molding method using an injection molding machine is preferable from the viewpoints of ease of molding, mass productivity, cost and the like.

Further, an injection molding method for molding the polypropylene resin composition of the present invention under temperature conditions within the range of the crystal melting temperature of the total aromatic liquid crystal polymer (crystal melting temperature of less than 260 ° C.) to the crystal melting temperature + 50 ° C. is more preferable. is there.

By injection molding the polypropylene resin composition of the present invention under the above temperature conditions, all aromatic liquid crystal polymers are uniformly dispersed in the polypropylene resin in a fibrous state, resulting in mechanical strength (bending strength, sharpy impact strength) and heat resistance. A molded product having excellent properties (deflection temperature under load) can be obtained.

In a suitable injection molding method, the content of the total aromatic liquid crystal polymer in the polypropylene resin composition is preferably 10 to 100 parts by mass, more preferably 15 to 50 parts by mass with respect to 100 parts by mass of the polypropylene resin.

The injection molding machine used for injection molding is not particularly limited, but may be any of a mold clamping mechanism type such as a direct pressure type (hydraulic type) and a toggle type, and a screw type (screw pre-plunger type, in-line screw type). , Etc.), a plunger method (single plunger type, plunger pre-plastic type, etc.) or other injection method may be used.

The direction of the cylinder may be any type such as horizontal type and vertical type, and may be any of a drive mechanism such as a hydraulic type, an electric type, or a combination type of both.

As the injection conditions, the optimum conditions can be appropriately selected depending on the size of the injection molding machine, the shape of the mold, and the number of pieces to be taken. The gate position and the number of gates can be selected according to the type of injection molded product.
The injection speed is not particularly limited, but is usually 300 mm / sec or less.

The mold temperature is preferably 25 to 100 ° C, more preferably 30 to 85 ° C.
If the mold temperature is less than 25 ° C, a short shot is likely to occur, and if it exceeds 100 ° C, the total aromatic liquid crystal polymer in the polypropylene resin tends to be less likely to be in a fibrous state.

In addition to the above-mentioned usual injection molding method, the injection molding method includes, for example, an injection molding method to which insert molding, injection compression molding, two-color molding, sandwich molding, gas assist molding and the like are applied.

The molded product composed of the polypropylene resin composition of the present invention is not particularly limited, and examples thereof include electrical / electronic parts, building parts, machine parts, and daily necessities.
Electrical and electronic components include, for example, housings for copy machines, personal computers, printers, electronic musical instruments, home-use game machines, portable game machines, and internal parts (connectors, switches, IC and LED housings, sockets, relays, etc. Resistors, capacitors, capacitors, coil bobbins, etc.).

Examples of building parts include curtain parts, blind parts, roof panels, heat insulating walls, adjusters, plastic bundles, ceiling fishing gear and the like.

Examples of mechanical parts include gears, screws, springs, bearings, levers, cams, ratchets, rollers and the like.

Examples of daily necessities include various cutlery, various toiletry parts, prepaid cards, saw blades for household wraps, food tray cases, food cups, and the like.

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

The crystal melting temperature, melt viscosity, melt volume flow rate, flexural modulus, shearpy impact strength, deflection temperature under load and linear expansion coefficient in the examples were measured by the methods described below.

(1) Crystal melting temperature Tm1 after observing the heat absorption peak temperature (Tm1) observed when measuring from room temperature to 20 ° C./min using Exstar6000 manufactured by Seiko Instruments Inc. as a differential scanning calorimeter. Hold at a higher temperature of 20-50 ° C for 10 minutes. Next, the sample was cooled to room temperature under a temperature lowering condition of 20 ° C./min, and the temperature at the peak top of the exothermic peak observed at that time was set to the crystallization temperature (Tc) of the total aromatic liquid crystal polymer, and then 20 again. The endothermic peak when measured under the temperature rising condition of ° C./min was observed, and the temperature indicating the peak top was defined as the crystal melting temperature (Tm) of the total aromatic liquid crystal polymer.

(2) Melt Viscosity Using a melt viscosity measuring device (Capillary Graph 1D manufactured by Toyo Seiki Co., Ltd.), using a capillary of 0.7 mmφ × 10 mm ^{, under the condition of a shear rate of 1000 sec -1} , LCP-1 is 260 ° C., LCP. The melt viscosities of -2 at 380 ° C. and LCP-3 at 320 ° C. were measured.

(3) Melt volume flow rate (MVR)
In accordance with ISO 1133, the measurement was carried out using Melt Indexer G-02 manufactured by Toyo Seiki Seisakusho Co., Ltd. under the conditions of 230 ° C. and a load of 2160 g. When the value of MVR is large, it means that the fluidity is high, the molding is easy, and the molding processability is excellent.

(4) Flexural modulus Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), the cylinder set temperature is 260 ° C (320 ° C for Comparative Example 4), the mold temperature is 40 ° C, and the length. A strip-shaped test piece having a width of 80.0 mm, a width of 10.0 mm and a thickness of 4.0 mm was formed, and the measurement was performed in accordance with ISO-178 using the strip-shaped test piece.

(5) Charpy Impact Strength Using an injection molding machine (UH1000-110 manufactured by Nissei Jushi Kogyo Co., Ltd.), the cylinder set temperature is set to 260 ° C (320 ° C for Comparative Example 4), the mold temperature is 40 ° C, and the length is long. It is molded into a strip-shaped test piece with a length of 80.0 mm, a width of 10.0 mm, and a thickness of 4.0 mm, conforms to ISO-179, and uses G-UB manufactured by Toyo Seiki Seisakusho Co., Ltd. as a digital impact tester. The notch type was A (the remaining width after notch processing was 8.0 mm), the hammer weighed 4 wJ, and the striking direction was measured under the condition of edgewise.

(6) Deflection temperature under load (DTUL)
Using the same test piece as the test piece used for measuring the flexural modulus, the measurement was performed in accordance with ISO-75 at a load of 0.46 MPa and a heating rate of 2 ° C./min.

(7) Linear expansion coefficient For the same test piece as the test piece used for measuring the flexural modulus, the length is 10.0 mm and the width is 10.0 mm by cutting with the flow direction (MD) of the molded product as the long side. A strip-shaped test piece having a thickness of 4.0 mm and a thickness of 4.0 mm was prepared and used as a measurement sample. Using a thermomechanical analyzer (TMA / SS6000) manufactured by Hitachi High-Tech Science Co., Ltd., the amount of change in sample length with respect to temperature change was measured in accordance with ASTM D696. The closer the value of the coefficient of linear expansion is to 0, the better the dimensional stability.

The abbreviations below represent the following compounds:

PP: Polypropylene resin LCP: Total aromatic liquid crystal polymer POB: 4-Hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid HQ: Hydroquinone BP: 4,4'-dihydroxybiphenyl TPA: Terephthalic acid

(Polypropylene resin)
In the examples, the following polypropylene resins were used.
PP-1: Block Polypropylene (Co. Prime Polymer Co., J715M, MVR12.9cm ^3/10 min, 230 ° C., load 2160 g)
PP-2: Propylene homopolymer (Co. Prime Polymer Co., J105G, MVR12.8cm ^3/10 min, 230 ° C., load 2160 g)
PP-3: Block Polypropylene (Co. Prime Polymer Co., J466HP, MVR4.1cm ^3/10 min, 230 ° C., load 2160 g)

(Synthesis of LCP)
[Synthesis Example 1 (LCP-1)]
BON6: 376.3 g (40 mol%), POB: 276.2 g (40 mol%), HQ: 55.1 g (10 mol%) and TPA in a reaction vessel equipped with a stirrer with a torque meter and a distillate. : 83.1 g (10 mol%) was charged, and 1.025 times mol of acetic anhydride was further charged with respect to the amount of hydroxyl groups (molar) of all the monomers, and deacetic acid polymerization was carried out under the following conditions.

The temperature was raised from room temperature to 150 ° C. over 1 hour under a nitrogen gas atmosphere, and the temperature was maintained at the same temperature for 30 minutes. Next, the temperature was rapidly raised to 210 ° C. while distilling 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 335 ° C. over 3 hours, and then reduced to 20 mmHg over 30 minutes. When a predetermined torque was exhibited, the polymerization reaction was terminated, the contents were taken out from the reaction vessel, and pellets of the total aromatic liquid crystal polymer 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 218 ° C., and the melting viscosity was 23 Pa · s.

[Synthesis Example 2 (LCP-2)]
POB: 323.2 g (36 mol%), BON 6: 48.9 g (4 mol%), BP: 169.4 g (14 mol%), HQ in a reaction vessel equipped with a stirrer with a torque meter and a distillate. : 114.5 g (16 mol%) and TPA: 323.9 g (30 mol%) were charged, and 1.03 times mol of acetic anhydride was further charged with respect to the amount of hydroxyl groups (mol) of all the monomers. Deacetic anhydride polymerization was carried out under the conditions.

The temperature was raised from room temperature to 145 ° C. over 1 hour under a nitrogen gas atmosphere, and the temperature was maintained at 145 ° C. for 30 minutes. Next, the temperature was raised to 350 ° C. over 7 hours while distilling 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 were taken out from the reaction vessel, and pellets of the total aromatic liquid crystal polymer 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 335 ° C., and the melting viscosity was 20 Pa · s.

[Synthesis Example 3 (LCP-3)]
POB: 655.4 g (73 mol%) and BON 6: 330.2 g (27 mol%) were charged in a reaction vessel equipped with a stirrer with a torque meter and a distillate, and the amount of hydroxyl groups (mol) of all the monomers was further charged. ), 1.03 times by mole of acetic anhydride was charged, and deacetic 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. 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 reduced to 20 mmHg over 90 minutes. When a predetermined torque was applied, the polymerization reaction was terminated, the contents of the reaction vessel were taken out, and pellets of the total aromatic liquid crystal polymer 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 278 ° C., and the melting viscosity was 23 Pa · s.

(Examples 1 to 6, Comparative Examples 1 to 4) (Example 5 is a reference example)
PP-1 to 3 and LCP-1 to 3 are blended so as to have the contents shown in the examples in Table 1, and a cylinder temperature is used using a twin-screw extruder (TEX-30 manufactured by Japan Steel Works, Ltd.). Was melt-kneaded at Tm + 10 + 30 ° C. of LCP to obtain pellets of a polypropylene resin composition.

For this resin composition, the melt volume flow rate (MVR), flexural modulus, Charpy impact strength, deflection temperature under load (DTUL) and linear expansion coefficient were measured by the above methods. The results are shown in Table 1.

Both the polypropylene resin composition (Examples 1-6) are in each example, melt volume flow rate (MVR) is 5.62~39.6cm ^3/10 minutes, flexural modulus 2.1~7.8GPa , Sharpy impact strength is 5.3 to 11.0 kJ / m ² , deflection temperature under load (DTUL) is 123 to 157 ° C, linear expansion coefficient is -0.08 x ^{10-5 to} 4.4 x ^10-5 / ° C. It was excellent in molding processability, mechanical strength, heat resistance and dimensional stability.

On the other hand, the polypropylene resin composition in Comparative Example 1 which does not contain the total aromatic liquid crystal polymer and Comparative Example 2 in which the content is less than a predetermined amount is inferior in molding processability, flexural modulus, heat resistance and dimensional stability. Met.

Further, in Comparative Example 3 using the total aromatic liquid crystal polymer LCP-2 (Tm 335 ° C.) having a high crystal melting temperature, a polypropylene resin composition could not be obtained due to thermal deterioration during melt kneading. Similarly, the polypropylene resin composition in Comparative Example 4 using the total aromatic liquid crystal polymer LCP-3 (Tm 278 ° C.) having a high crystal melting temperature is inferior in moldability, mechanical strength, heat resistance and dimensional stability. It was.

(Example 7, Comparative Examples 5 and 6)
The polypropylene resin composition of Example 1 (pellet containing 25 parts by mass of LCP-1 at Tm 218 ° C.) was described above in the same manner as in Example 1 except that a test piece was molded at the cylinder set temperature shown in Table 2. Flexural modulus, shearpy impact strength and deflection temperature under load (DTUL) were measured by the method (Examples 7 and Comparative Examples 5 and 6). The results are shown in Table 2.

Molded products (Examples 1 and 7) obtained at a molding temperature within the temperature range of the crystal melting temperature of the total aromatic liquid crystal polymer to the crystal melting temperature + 50 ° C. have a flexural modulus, a shearpy impact strength, and a deflection temperature under load (DTUL). Excellent results were obtained. On the other hand, the molded products (Comparative Examples 5 and 6) obtained at a molding temperature outside the above temperature range were inferior in flexural modulus and tended to decrease in Charpy impact strength.

Claims (8)

A polypropylene resin composition containing 10 to 500 parts by mass of a total aromatic liquid crystal polymer having a crystal melting temperature of less than 260 ° C. with respect to 100 parts by mass of the polypropylene resin.
Polypropylene resin contains block polypropylene,
Melt volume flow rate (ISO 1133,230 ℃, load 2160 g) is 3~100cm ^3/10 min,
Flexural modulus (ISO-178) is 2.0 GPa or more, and
A polypropylene resin composition having a Charpy impact strength (ISO-179) of 3.0 kJ / m ^{2 or more.} The polypropylene resin composition according to claim 1, wherein the deflection temperature under load (ISO-75, load 0.46 MPa) is 100 ° C. or higher. The polypropylene resin composition according to claim 1 or 2, wherein the room temperature xylene-soluble component in the block polypropylene is 1 to 50% by mass. All aromatic liquid crystal polymers are represented by formulas (I)-(IV).

[During the ceremony,
Ar ₁ and Ar ₂ represent one or more divalent aromatic groups, respectively, and p, q, r and s are the composition ratios of each repeating unit in the total aromatic liquid crystal polyester (respectively). Mol%), which meets the following conditions:
0.5 ≤ p / q ≤ 2.5
2 ≦ r ≦ 15, and 2 ≦ s ≦ 15]
The polypropylene resin composition according to any one of claims 1 to 3, which is a totally aromatic liquid crystal polyester containing a repeating unit represented by. Ar ₁ and Ar ₂ are independent of each other and have equations (1) to (4).

The polypropylene resin composition according to claim 4, which comprises one or more selected from the group consisting of aromatic groups represented by. The automobile exterior according to any one of claims 1 to 5, wherein the polypropylene resin composition contains 10 to 233 parts by mass of a total aromatic liquid crystal polymer having a crystal melting temperature of less than 260 ° C. with respect to 100 parts by mass of the polypropylene resin. parts. The polypropylene resin composition according to any one of claims 1 to 6 , wherein the polypropylene resin composition contains 1 to 150 parts by mass of an inorganic filler with respect to 100 parts by mass of the polypropylene resin. A molded product composed of the polypropylene resin composition according to any one of claims 1 to 7.