JP7194049B2 - resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an ethylene-vinyl alcohol copolymer resin composition with improved heat resistance, mechanical strength, water absorption and gas barrier properties.

Ethylene-vinyl alcohol copolymer (hereinafter also referred to as "EVOH") is a resin obtained by copolymerizing and saponifying ethylene and vinyl ester, and has excellent gas barrier properties in a low-humidity environment. Unlike vinyl chloride resin, it does not generate harmful gases when incinerated, and is environmentally friendly. Therefore, ethylene-vinyl alcohol copolymers are widely used as packaging containers for foods, pharmaceuticals, cosmetics, agricultural products, industrial products, gasoline tanks for automobiles, tubes for tires, and the like.

However, since EVOH has hydroxyl groups in the polymer main chain, it has a high water absorption rate, and also has problems of insufficient oxygen gas barrier properties and water vapor barrier properties in a high humidity environment.

For the purpose of improving gas and liquid permeability of EVOH, a method of blending a liquid crystal polymer has been proposed (Patent Document 1).

JP-A-2001-172445

In Patent Document 1, the liquid crystal polymer to be blended with EVOH is a semi-aromatic liquid crystal polymer containing ethylenedioxy units as a constituent, and has a relatively high melting point of 265 ° C. Therefore, during melt kneading, Since EVOH is thermally decomposed, there is a problem that the heat resistance, mechanical properties, and gas barrier properties of the obtained resin composition are deteriorated.

An object of the present invention is to provide a resin composition with improved water absorption and excellent heat resistance, mechanical strength and gas barrier properties.

In view of the above-mentioned problems, the present inventors have made intensive studies on improving the hygroscopicity and physical properties of EVOH. In addition, the inventors have found that a resin composition having excellent heat resistance, mechanical properties and gas barrier properties can be obtained, and have completed the present invention.

That is, the present invention provides a resin composition containing 100 parts by mass of an ethylene-vinyl alcohol copolymer resin and 0.1 to 100 parts by mass of a wholly aromatic liquid crystal polymer having a crystal melting temperature of 260° C. or lower.

According to the present invention, it is possible to obtain a resin composition and a molded article having improved water absorbency and excellent heat resistance, mechanical properties and gas barrier properties.

The resin composition of the present invention contains an ethylene-vinyl alcohol copolymer resin (EVOH) and a wholly aromatic liquid crystal polymer as essential components.

The EVOH used in the resin composition of the present invention is a copolymer mainly composed of ethylene units and vinyl alcohol units, and is obtained by saponifying the vinyl ester units in the ethylene-vinyl ester copolymer. . The EVOH used in the present invention is not particularly limited, and any known EVOH that can be used in melt molding applications can be used. EVOH can be used alone or in combination of two or more.

The lower limit of the content of ethylene units in EVOH is preferably 20 mol %, more preferably 24 mol %. When the above lower limit is not reached, the melt moldability of the resulting resin composition may deteriorate. On the other hand, the upper limit of the content of ethylene units in EVOH is preferably 65 mol%, more preferably 60 mol%, and even more preferably 48 mol%. If the above upper limit is exceeded, the gas barrier properties of the resulting resin composition may deteriorate.

Although the degree of saponification of EVOH is not particularly limited, it is preferably 90 mol% or more, more preferably 95 mol% or more, more preferably 99 mol%, from the viewpoint of maintaining the gas barrier properties of the resulting resin composition. It is more preferable that it is above.

The melt flow rate of EVOH (measured by the method described in ISO 1133 under conditions of a temperature of 190 ° C. and a load of 2160 g, hereinafter, "melt flow rate" may be referred to as "MFR") is not particularly limited, but the lower limit is preferably 0.1 g/10 minutes, more preferably 0.5 g/10 minutes, and even more preferably 1.0 g/10 minutes. On the other hand, the upper limit of MFR is preferably 60 g/10 minutes, more preferably 40 g/10 minutes, and even more preferably 20 g/10 minutes. When the MFR is within the above range, the moldability and workability of the resulting resin composition are improved.

EVOH may have other structural units in addition to ethylene units, vinyl alcohol units and vinyl ester units. Other structural units include units derived from vinylsilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(β-methoxy-ethoxy)silane, and γ-methacryloxypropylmethoxysilane. Among these, units derived from vinyltrimethoxysilane or vinyltriethoxysilane are preferred. Further, EVOH is, within a range that does not hinder the object of the present invention, olefins such as propylene and butylene; unsaturated carboxylic acids such as (meth)acrylic acid and methyl (meth)acrylate or their esters; N-vinylpyrrolidone and the like. It may have units derived from vinylpyrrolidone. The content of units other than ethylene units, vinyl alcohol units and vinyl ester units is preferably 10 mol % or less, more preferably 5 mol % or less, relative to all structural units.

A method for producing EVOH includes, for example, a method for producing ethylene-vinyl ester copolymer according to a known method and then saponifying it to produce EVOH. Ethylene-vinyl ester copolymers can be produced, for example, by dissolving ethylene and vinyl ester in an organic solvent such as methanol, t-butyl alcohol, dimethyl sulfoxide, etc. under pressure to form radicals such as benzoyl peroxide and azobisisobutyronitrile. It is obtained by polymerizing using a polymerization initiator. As the raw material vinyl ester, vinyl acetate, vinyl propionate, vinyl pivalate, and the like can be used, and among these, vinyl acetate is preferred. An acid catalyst or an alkali catalyst can be used for saponification of the ethylene-vinyl ester copolymer.

The wholly aromatic liquid crystalline polymer used in the resin composition of the present invention is a wholly aromatic liquid crystalline polyester or wholly aromatic liquid crystalline polyester amide which forms an anisotropic melt phase and is called a thermotropic liquid crystalline polymer by those skilled in the art.

The properties of the anisotropic melt phase of the wholly aromatic liquid crystal polymer can be confirmed by a normal deflection inspection method using crossed polarizers, that is, by observing a sample placed on a hot stage under a nitrogen atmosphere.

Repeating units constituting the wholly aromatic liquid crystal polymer used in the present invention include aromatic oxycarbonyl repeating units, aromatic dicarbonyl repeating units, aromatic dioxy repeating units, aromatic aminooxy repeating units, and aromatic diamino repeating units. , aromatic aminocarbonyl repeat units and combinations thereof.

Specific examples of monomers that give aromatic oxycarbonyl repeating units include, for example, aromatic hydroxycarboxylic acids such as 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2 -naphthoic acid, 5-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl- 3-benzoic acid and the like, alkyl, alkoxy or halogen-substituted products thereof, and ester-forming derivatives such as acylates, ester derivatives and acid halides thereof. Among these, 4-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are easy to adjust the mechanical properties, heat resistance, crystal melting temperature, and moldability of the obtained wholly aromatic liquid crystal polymer to an appropriate level. preferable.

Specific examples of monomers that give aromatic dicarbonyl repeating units include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7 -naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, etc., alkyl, alkoxy or halogen-substituted products thereof, ester derivatives thereof, ester-forming derivatives such as acid halides, etc. 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 resulting wholly aromatic liquid crystal polymer can be easily adjusted to appropriate levels.

Specific examples of monomers that give aromatic dioxy repeating units include aromatic diols such as hydroquinone, resorcinol, 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 alkyl, alkoxy or halogen substituted versions thereof; and ester-forming derivatives such as acylated products thereof. Among these, hydroquinone and 4,4'-dihydroxybiphenyl are easy to adjust reactivity during polymerization, mechanical properties, heat resistance, crystal melting temperature, and moldability of the resulting wholly aromatic liquid crystal polymer to appropriate levels. preferred from

Monomers that provide aromatic aminooxy repeat units, aromatic diamino repeat units and aromatic aminocarbonyl repeat units include aromatic hydroxylamines, aromatic diamines and aromatic aminocarboxylic acids.

The wholly aromatic liquid crystal polymer used in the present invention may contain aromatic oxydicarbonyl repeating units and thioester bonds as long as the objects of the present invention are not impaired. Monomers that provide thioester bonds include mercaptoaromatic carboxylic acids, and aromatic dithiols and hydroxyaromatic thiols. The amounts of these monomers used are limited to 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 with respect to the total including the total amount of monomers and the like to be provided.

Copolymers that combine these repeating units may or may not form an anisotropic melt 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 wholly aromatic liquid crystalline polymers used in the present invention are limited to copolymers that form anisotropic melt phases.

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

The crystal melting temperature of the wholly aromatic liquid crystal polymer used in the present invention measured by a differential scanning calorimeter is 260° C. or lower, preferably 255° C. or lower, more preferably 250° C. or lower, and still more preferably 240° C. ℃ or less. The crystal melting temperature of the wholly aromatic liquid crystal polymer is usually 210° C. or higher, in some cases 211° C. or higher, in another case 212° C. or higher, and in another case 213° C. or higher. .

When the crystal melting temperature of the wholly aromatic liquid crystal polymer is within the above temperature range, the wholly aromatic liquid crystal polymer is easily dispersed uniformly in the matrix EVOH, and when molding, the excellent It becomes easier to obtain mechanical properties and heat resistance.

In the present specification and claims, the term "crystal melting temperature" refers to the crystal melting temperature measured at a heating rate of 20°C/min with a differential scanning calorimeter (hereinafter abbreviated as DSC). It is obtained from the peak temperature. More specifically, after observing the endothermic peak temperature (Tm1) observed when measuring the wholly aromatic liquid crystal polymer sample under the condition of increasing the temperature from room temperature by 20° C./min, it is 20 to 50° C. higher than Tm1. The temperature is held for 10 minutes, then the sample is cooled to room temperature under the condition of temperature decrease of 20°C/min, and then the endothermic peak when measured again under the condition of temperature increase of 20°C/min is observed, and the peak top is shown. The temperature is defined as the crystalline melting temperature of the wholly aromatic liquid crystal polymer. As a measuring instrument, for example, Exstar6000 manufactured by Seiko Instruments Inc. can be used.

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

When the melt viscosity is less than 1 Pa·s, uniform dispersion tends to be difficult, and when it exceeds 200 Pa·s, uniform dispersion tends to be difficult.

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

[In the formula,
Ar ₁ and Ar ₂ each represent one or more divalent aromatic groups, and p, q, r and s respectively represent the composition ratio of each repeating unit in the wholly aromatic liquid crystalline polyester ( mol%), which satisfies 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 formula (I) and the composition ratio q (mol%) according to the formula (II) is more preferably 0.6 to 1.8, and 0 0.8 to 1.6 is more preferred.

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

Regarding the wholly aromatic liquid crystal polyester that is preferably used, the composition ratio p according to formula (I) and the composition ratio q according to formula (II) are preferably 32 to 54 mol%, respectively, and 36 to 52 mol%. is more preferred.

The wholly aromatic liquid crystalline polyester preferably used in the present invention contains at least the above molar ratio (p/q) of the repeating units represented by formula (I) and formula (II), and optionally the above p and By including the total composition ratio of q and/or the composition ratio (mol%) of each of p and q, a crystalline melting temperature of 260° C. or less is indicated.

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

In the above repeating unit, for example, Ar ₁ (or Ar ₂ ) represents two or more divalent aromatic groups means that the repeating unit represented by formula (III) (or (IV)) is wholly aromatic It means that two or more types are contained in the liquid crystalline polyester according to the type of divalent aromatic group. In this case, the composition ratio r according to formula (III) (or the composition ratio s according to formula (IV)) represents the total composition ratio of two or more repeating units.

Specific examples of monomers that provide repeating units represented by formula (I) include 4-hydroxybenzoic acid and ester-forming derivatives such as acylates, ester derivatives and acid halides thereof.

Specific examples of monomers that give repeating units represented by formula (II) include 6-hydroxy-2-naphthoic acid and its acylated products, ester derivatives, and ester-forming derivatives such as acid halides. be done.

Specific examples of monomers that give repeating units represented by formula (III) include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and 1,6-naphthalenedicarboxylic acid. , 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4′-dicarboxybiphenyl, etc., and alkyl, alkoxy or halogen-substituted products thereof, ester derivatives thereof, esters such as acid halides, etc. Formative derivatives are mentioned.

Specific examples of monomers that give repeating units represented by formula (IV) include aromatic diols such as hydroquinone, resorcinol, 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, etc., and alkyl and alkoxy thereof Alternatively, halogen-substituted products and ester-forming derivatives such as acylated products thereof may be mentioned.

Further, among the wholly aromatic liquid crystal polyesters preferably used in the present invention, Ar ₁ and Ar ₂ related to the repeating units represented by the formulas (III) and (IV) are each independently represented by the formula ( A wholly aromatic liquid crystalline polyester containing one or more selected from the group consisting of aromatic groups represented by 1) to (4) is more preferably used.

Among them, the repeating units represented by formula (III) are aromatic groups represented by formulas (1) and (4), that is, the monomers giving these repeating units are terephthalic acid and The use of 2,6-naphthalenedicarboxylic acid and ester-forming derivatives thereof makes it easy to adjust the mechanical properties, heat resistance, crystal melting temperature and moldability of the obtained wholly aromatic liquid crystalline polyester to appropriate levels. Especially preferred.

Further, the repeating units represented by formula (IV) include aromatic groups represented by formulas (1) and (3). The use of '-dihydroxybiphenyl and ester-forming derivatives thereof adjusts the reactivity during polymerization and the mechanical properties, heat resistance, crystal melting temperature and moldability of the obtained wholly aromatic liquid crystalline polyester to appropriate levels. It is particularly preferred because it is easy to use.

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

In the wholly aromatic liquid crystalline polyester preferably used in the present invention, the total composition ratio [p + q + r + s] of the repeating units is preferably 100 mol%, but other repeating units may be added within the range not impairing the object of the present invention. Further, it may be contained.

Monomers that give other repeating units constituting the wholly aromatic liquid crystalline polyester preferably used in the present invention include other aromatic hydroxycarboxylic acids, aromatic hydroxyamines, aromatic diamines and aromatic aminocarboxylic acids. , aromatic hydroxydicarboxylic acids, aromatic mercaptocarboxylic acids, aromatic dithiols, aromatic mercaptophenols and combinations thereof.

Specific examples of other aromatic hydroxycarboxylic acids include 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 5-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4'-hydroxyphenyl -4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid and their alkyl, alkoxy or halogen substituted products, and their acylated products, ester derivatives and acid halides and ester-forming derivatives such as

The total compositional ratio of repeating units provided by these other monomer components is preferably 10 mol % or less in the entire repeating units.

A method for producing the wholly aromatic liquid crystal polymer used in the present invention will be described below.

The method for producing the wholly 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 consisting of a combination of the above monomers, such as a melt acidolysis method, a slurry polymerization method, or the like. Legal, etc. can be used.

The melt acidolysis method, which is the preferred method for use in the method of making the wholly aromatic liquid crystalline polymers used in the present invention, involves first heating the monomers to form a melt of reactants. , and then continue the reaction to obtain a molten polymer. A vacuum may be applied to facilitate removal of volatiles (eg, acetic acid, water, etc.) that are by-produced in the final stages of condensation.

Slurry polymerization is a process in which the reaction is carried out in the presence of a heat exchange fluid and the solid product is obtained in suspension in the heat exchange medium.

In both the melt acidolysis method and the slurry polymerization method, the polymerizable monomer component used in producing the wholly aromatic liquid crystal polymer is a modified form obtained by acylating hydroxyl groups and/or amino groups at room temperature. , that is, it can be subjected to the reaction as a lower acylated product. The lower acyl group preferably has 2 to 5 carbon atoms, more preferably 2 or 3 carbon atoms. Particularly preferred is a method of using an acetylated product of the above monomer for the reaction.

The acylated product of the monomer may be previously synthesized by acylating separately, or may be produced in the reaction system by adding an acylating agent such as acetic anhydride to the monomer during the production of the wholly aromatic liquid crystal polymer. You can also harass.

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

Specific examples of catalysts include organic tin compounds such as dialkyltin oxide (e.g., dibutyltin oxide) and diaryltin oxide; metal oxides such as titanium dioxide; antimony compounds such as antimony trioxide; titanium compounds; alkali and alkaline earth metal salts of carboxylic acids (eg potassium acetate); gaseous acid catalysts such as Lewis acids (eg boron trifluoride), hydrogen halides (eg hydrogen chloride) and the like.

The proportion of the catalyst used is generally 1-1000 ppm, preferably 2-100 ppm, relative to the total amount of monomers.

The wholly aromatic liquid crystal polymer thus obtained by the polycondensation reaction is extracted from the polymerization reactor in a molten state, and then processed into pellets, flakes, or powder.

The content of the wholly aromatic liquid crystal polymer in the resin composition of the present invention is 0.1 to 100 parts by mass, preferably 1 to 90 parts by mass, and more preferably 3 to 80 parts by mass with respect to 100 parts by mass of EVOH. , more preferably 5 to 70 parts by mass.

If the content of the wholly aromatic liquid crystal polymer is less than 0.1 parts by mass, the effect of improving water absorption, mechanical strength and heat resistance is not sufficiently obtained, and if it exceeds 100 parts by mass, flexibility tends to decrease. be.

The resin composition of the present invention is characterized in that the wholly aromatic liquid crystal polymer to be blended has a crystalline melting temperature of 260° C. or less. Since blending by melt-kneading is possible, thermal decomposition of EVOH is suppressed, water absorption is improved, and a resin composition having excellent heat resistance, mechanical strength and gas barrier properties can be obtained.

Therefore, a compatibilizer is not particularly necessary for blending, but a compatibilizer may be added for the purpose of further improving the compatibility between EVOH and the wholly aromatic liquid crystal polymer. When a compatibilizer is added, the amount added is preferably 0.5 to 10 parts by mass, more preferably 1 to 5 parts by mass, per 100 parts by mass of EVOH.

The resin composition of the present invention may further contain inorganic and/or organic fillers as optional components.

Specific examples of inorganic and/or organic fillers that may be contained in the resin composition of the present invention include glass fiber, silica alumina fiber, alumina fiber, carbon fiber, potassium titanate fiber, and aluminum borate fiber. , aramid fiber, polyarylate fiber, polybenzimidazole fiber, talc, mica, graphite, wollastonite, dolomite, clay, glass flakes, glass beads, glass balloons, calcium carbonate, barium sulfate, titanium oxide, etc. or in combination of two or more.

Among these, talc is preferable because it has an excellent balance between physical properties and cost.

Also, the inorganic and/or organic fillers may be surface-treated. Examples of surface treatment methods include a method of adsorbing a surface treatment agent to the surface of the filler, a method of adding a surface treatment agent during kneading, and the like.

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

The content when blending inorganic and/or organic fillers is preferably 1 to 150 parts by mass, preferably 10 to 100 parts by mass, with respect to 100 parts by mass of the total amount of EVOH and wholly aromatic liquid crystal polymer. It is more preferable to have

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 resin composition due to the inorganic and/or organic filler. Liquidity tends to decline.

In addition to EVOH and the wholly aromatic liquid crystal polymer, other additives and resin components may be added to the resin composition of the present invention as long as the objects of the present invention are not impaired.

Specific examples of other additives include lubricants such as higher fatty acids, higher fatty acid esters, higher fatty acid amides, and higher fatty acid metal salts (herein, higher fatty acids refer to those having 10 to 25 carbon atoms). , release improvers such as polysiloxane and fluorine resin, coloring agents such as dyes, pigments, carbon black, flame retardants, antistatic agents, surfactants, nucleating agents such as talc, organic phosphates, and sorbitol. antiblocking agents, antioxidants such as phosphorus antioxidants, phenolic antioxidants, sulfur antioxidants, weathering agents, heat stabilizers, neutralizers, and the like. These additives can be used alone or in combination of two or more.

The total amount of other additives in the 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 EVOH and the wholly aromatic liquid crystal polymer. is.

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 resin composition during molding tends to deteriorate. .

In addition, among the above other additives, when using additives such as lubricants, mold release agents, anti-blocking agents, etc., they may be added when preparing the resin composition, or may be added when the resin composition is molded. You may attach to the pellet surface of a thing.

Specific examples of other resin components include, for example, thermoplastic resins such as polyamide, polyester, polyacetal, polyphenylene ether and modified products thereof, polysulfone, polyethersulfone, polyetherimide, and polyamideimide, and thermosetting resins. Some phenolic resins, epoxy resins, polyimide resins, and the like can be mentioned. 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 EVOH and the wholly aromatic liquid crystal polymer. is more preferable.

The resin composition of the present invention is prepared by mixing EVOH and a wholly aromatic liquid crystal polymer, as well as compatibilizers, inorganic and/or organic fillers, other additives, and other resin components, followed by a Banbury mixer, kneader, uniaxial or Using a twin-screw extruder or the like, it can be obtained by melt-kneading under temperature conditions from the vicinity of the crystal melting temperature of the wholly aromatic liquid crystal polymer to +40° C. of the crystal melting temperature.

Other resin components and other additives may be blended in advance with either EVOH or the wholly aromatic liquid crystal polymer, or a resin composition obtained by melt-kneading EVOH and the wholly aromatic liquid crystal polymer. may be blended when molding.

The resin composition of the present invention has a molded article formed therefrom that has a deflection temperature under load (load 0.46 MPa) in accordance with ISO 75. It is 225° C., more preferably 95 to 200° C., and has the advantage of excellent heat resistance.

The resin composition of the present invention has a tensile strength of 55 MPa or more, preferably 58 to 160 MPa, and more preferably 60 to 130 MPa in accordance with ISO 527-1 for molded articles formed therefrom.

The resin composition of the present invention has a bending strength of 85 MPa or more, preferably 90 to 190 MPa, and more preferably 95 to 170 MPa in accordance with ISO 178 for a molded product formed therefrom.

The resin composition of the present invention has a flexural modulus of 10.0 GPa or less, preferably 3.3 to 9.0 GPa, more preferably 3.4 to 8.0 GPa, in accordance with ISO 178 for a molded product formed therefrom. is.

The resin composition of the present invention has a Charpy impact strength (23° C.) conforming to ISO 179 of 1.0 kJ/m ² or more, preferably 1.0 to 100 kJ/m 2 , more preferably 1.0 to 100 kJ/m ² , more preferably 1.1 to 80 kJ/m ² , more preferably 1.2 to 60 kJ/m ² .

The resin composition of the present invention has a water vapor permeability of preferably 20 g/m ² ·24 h or less, more preferably 10 g/m ² ·24 h or less in a 100 μm film conforming to JIS K7129-B for a molded article formed therefrom. , more preferably 8 g/m ² ·24h or less, particularly preferably 7 g/m ² ·24h or less, and usually 0.01 g/m ² ·24h or more, and are said to have low water vapor permeability and excellent gas barrier properties. have advantages.

The resin composition of the present invention preferably has an oxygen gas permeability of 5.0 cm ³ /m ² ·24 h·atm or less, more preferably 3 in a 100 μm film conforming to JIS K7126-2 for a molded article formed therefrom. 0 cm ³ /m ² ·24 h·atm or less, particularly preferably 1.3 cm ³ /m ² ·24 h·atm or less, and usually 0.01 cm ³ /m ² ·24 h·atm or more, high humidity It has the advantages of low oxygen gas permeability under certain conditions and excellent gas barrier properties.

Examples of methods for obtaining a molded article composed of the 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, injection molding, extrusion molding, or blow molding is preferable from the viewpoint of ease of molding, mass productivity, cost, and the like.

Further, a molding method in which the resin composition of the present invention is molded under temperature conditions within the range from the crystal melting temperature of the wholly aromatic liquid crystal polymer (crystal melting temperature of 260° C. or less) to the crystal melting temperature +50° C. is more preferable.

By molding the resin composition of the present invention under the above temperature conditions, the wholly aromatic liquid crystal polymer is uniformly dispersed in EVOH, and the mechanical strength (tensile strength, bending strength, Charpy impact strength) and heat resistance (load A molded article having excellent deflection temperature can be obtained.

When injection molding is adopted, the injection molding machine used for injection molding is not particularly limited. Any injection method such as a screw pre-plasticizer type, an in-line screw type, etc.) or a plunger method (single plunger type, plunger pre-plasticizer type, etc.) may be used.

As for the direction of the cylinder, it may be of any type, such as horizontal or vertical, and may be driven by any type of drive mechanism, such as a hydraulic type, an electric type, or a combination of both types.

Optimal injection 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 molded. 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 25-100°C, more preferably 30-85°C.

When the mold temperature is less than 25°C, short shots tend to occur, and when it exceeds 100°C, the molding cycle becomes long.

The injection molding method includes, in addition to the usual injection molding method described above, injection molding methods such as insert molding, injection compression molding, two-color molding, sandwich molding, and gas-assisted molding.

When extrusion molding or blow molding is adopted, it can be processed into films, sheets, containers, pipes, fibers, etc., and it may be a single-layer molded body. A multi-layer molded body having different layers may also be used. It is also possible to uniaxially or biaxially stretch films, sheets, fibers and the like. In addition, the obtained molded article may be subjected to secondary processing such as bending, vacuum forming, blow molding, and press molding to obtain the intended molded article, if necessary.

The molded article composed of the resin composition of the present invention is not particularly limited, but examples thereof include mechanical parts, electrical/electronic parts, construction/civil engineering materials, household/office supplies, furniture parts, and daily necessities. , particularly molded articles as containers are useful.

Examples of electric and electronic parts include housings for copiers, personal computers, printers, electronic musical instruments, home game machines, and portable game machines, and internal parts (connectors, switches, IC and LED housings, sockets, relays, resistors, capacitors, capacitors, coil bobbins, etc.).

Building parts include, for example, curtain parts, blind parts, roof panels, heat-insulating walls, adjusters, plastic bundles, ceiling hooks, and the like.

Mechanical parts include, for example, 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 plastic wrap, food tray cases, food cups, and the like.

Containers made from the resin composition of the present invention include rice products, processed foods, side dishes, pickles, Japanese sweets, western sweets, juices, alcoholic beverages, food and drink such as seasonings, cosmetics such as hair styling products, foundations and perfumes, and hand washing. It can be used as a container for storing various contents such as detergents for hair, facial cleansers, kitchen detergents, laundry detergents, shampoos, rinses and the like. Among these, it is particularly useful as a container for storing food and drink.

The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these.

Crystal melting temperature, deflection temperature under load (DTUL), tensile strength, flexural strength, flexural modulus, Charpy impact strength, water vapor permeability, water absorption rate and oxygen gas permeability in the examples were measured by the methods described below. .

<Crystal melting temperature>
The measurement was performed using a differential scanning calorimeter (DSC) Exstar 6000 manufactured by Seiko Instruments Inc. A sample of wholly aromatic liquid crystal polymer is measured from room temperature at a temperature increase of 20° C./min, and after observing the endothermic peak temperature (Tm1), it is held at a temperature 20 to 50° C. higher than Tm1 for 10 minutes. Then, after cooling the sample to room temperature under the temperature decreasing condition of 20° C./min, the endothermic peak was measured again under the temperature increasing condition of 20° C./min. Crystal melting temperature.

<Deflection temperature under load (DTUL)>
Using an injection molding machine (UH1000-110 manufactured by Nissei Plastic Industry Co., Ltd.), the cylinder setting temperature is 230 ° C., the mold temperature is 50 ° C., the length is 80.0 mm, the width is 10.0 mm, and the thickness is 4.0 mm. It was molded into a strip-shaped test piece, and was used for measurement according to ISO 75 under a load of 0.46 MPa and a heating rate of 2° C./min.

<Tensile strength>
Using an injection molding machine (UH1000-110 manufactured by Nissei Plastic Industry Co., Ltd.), injection molding was performed at a cylinder setting temperature of 230 ° C. and a mold temperature of 50 ° C., and a type A1 dumbbell test piece with a thickness of 4.0 mm was produced. . Using INSTRON 5567 (a universal testing machine manufactured by Instron Japan Co., Ltd.), using a contact type extensometer with a gauge length of 50 mm, a test speed of 5 mm / min, and a chuck distance of 115 mm, ISO 527-1 Measured according to

<Bending strength, bending elastic modulus>
Measurements were made in accordance with ISO 178 using the same specimens as those used for measuring deflection temperature under load.

<Charpy impact strength>
Using the same test piece as the test piece used to measure the deflection temperature under load, conforming to ISO 179, using G-UB manufactured by Toyo Seiki Seisakusho Co., Ltd. as a digital impact tester, the notch type is A (notch The remaining width after processing was 8.0 mm), the weight of the hammer was 4 wJ, and the hitting direction was edgewise.

<Water vapor permeability>
A film having a thickness of 100 μm was prepared by the T-die method, and was subjected to a water vapor permeability test at a temperature of 40° C. and a humidity of 90% according to JIS K7129-B.

<Water absorption rate>
Using an injection molding machine (UH1000-110 manufactured by Nissei Plastic Industry Co., Ltd.), a cylinder setting temperature of 230 ° C. is used to mold a disc-shaped test piece with a diameter of 50.0 mm and a thickness of 3.0 mm. After being placed under constant temperature and humidity of 23° C. and 50% for 48 hours, it was immersed in water of 23° C. for 24 hours in accordance with ISO 62, and the water absorption was calculated from the weight change before and after immersion.

<Oxygen gas permeability>
A film having a thickness of 100 μm was prepared by the T-die method, and an oxygen gas permeability test was conducted at a temperature of 20° C. and a humidity of 90% according to JIS K7126-2.

In the examples, the following abbreviations represent the following compounds.
EVOH: ethylene-vinyl alcohol copolymer resin LCP: wholly aromatic liquid crystal polymer POB: 4-hydroxybenzoic acid BON6: 6-hydroxy-2-naphthoic acid HQ: hydroquinone BP: 4,4'-dihydroxybiphenyl TPA: terephthalic acid

(EVOH)
The following were used as EVOH.
EVAL (registered trademark) E105B (44 mol% ethylene content, MFR 5.5 g/10 minutes) manufactured by Kuraray Co., Ltd.

(Synthesis of Wholly Aromatic Liquid Crystal Polymer)
[Synthesis Example 1 (LCP-1)]
POB: 276.2 g (40 mol %), BON6: 376.4 g (40 mol %), HQ: 55.1 g (10 mol %) and TPA were added to a reaction vessel equipped with a stirrer with a torque meter and a distillation tube. : 83.1 g (10 mol %) was added, and 1.025 times mol of acetic anhydride was added to the hydroxyl group amount (mol) of all the monomers, and deacetic acid polymerization was carried out under the following conditions.

In a nitrogen gas atmosphere, the temperature was raised from room temperature to 150° C. over 1 hour and maintained at the same temperature for 30 minutes. Subsequently, the temperature was rapidly raised to 210° C. while distilling off the by-produced acetic acid, and the temperature was maintained for 30 minutes. Then, after raising the temperature to 335° C. over 3 hours, the pressure was 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 reactor, and pellets of the wholly aromatic liquid crystal polymer were obtained with a pulverizer. The amount of acetic acid distilled off during polymerization was almost the same as the theoretical value. The crystalline melting temperature (Tm) of the pellets obtained was 218°C.

[Synthesis Example 2 (LCP-2)]
POB: 323.2 g (36 mol %), BON6: 48.9 g (4 mol %), TPA: 323.9 g (30 mol %), BP : 169.4 g (14 mol %) and HQ: 114.5 g (16 mol %) were charged, and acetic anhydride was charged in an amount of 1.03 times the amount of hydroxyl groups (mol) of all monomers. Deacetic acid polymerization was carried out under the following conditions.

Under a nitrogen gas atmosphere, the temperature was raised from room temperature to 145° C. over 1 hour and maintained at 145° C. for 30 minutes. Next, the temperature was raised to 350° C. over 7 hours while acetic acid, which was produced as a by-product, was distilled off, 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 reactor, and pellets of the wholly aromatic liquid crystal polymer were obtained with a pulverizer. The amount of acetic acid distilled off during polymerization was almost the same as the theoretical value. The crystalline melting temperature (Tm) of the obtained pellets was 335°C.

[Examples 1 to 3 and Comparative Examples 1 to 3]
EVOH and LCP-1 to 2 were blended so as to have the contents shown in Table 1, and using a twin-screw extruder (TEX-30 manufactured by Nippon Steel Co., Ltd.), the cylinder temperature was adjusted to the crystal melting temperature of LCP. The mixture was melt-kneaded at +10 to +30° C. to obtain pellets of the resin composition.

Using the obtained pellets, deflection temperature under load, tensile strength, bending strength, Charpy impact strength, water vapor permeability, water absorption and oxygen gas permeability were measured by the above methods. Table 1 shows the results.

The resin composition (Examples 1 to 3) in each example has a deflection temperature under load (DTUL) of 98 to 147°C, a tensile strength of 62 to 119 MPa, a bending strength of 98 to 134 MPa, and a Charpy impact strength of 2. 0 to 2.8 kJ/m ² , water vapor permeability of 4.3 to 6.5 g/m ² ·24 h, water absorption of 0.07 to 0.56%, oxygen gas permeability of 1.0 to 1.2 cm ³ /m ² ·24 h·atm, and was excellent in heat resistance, mechanical strength, water vapor barrier properties, low water absorption, and oxygen gas barrier properties under high humidity conditions.

On the other hand, the resin composition of Comparative Example 1 containing no LCP was inferior in heat resistance, mechanical strength, water vapor barrier properties, water absorbency, and oxygen gas barrier properties.

The resin composition in Comparative Example 2, in which the LCP content was greater than the predetermined amount, had a high flexural modulus, decreased flexibility, and poor film workability.

In addition, in Comparative Example 3 using LCP (LCP-2) with a high crystal melting temperature, EVOH was thermally degraded during melt kneading to generate a large amount of cracked gas, and the discharge of extruded strands was not stable. couldn't get stuff.

本発明の好ましい態様は以下を包含する。
〔１〕エチレン-ビニルアルコール共重合体樹脂１００質量部、および
結晶融解温度が２６０℃以下である全芳香族液晶ポリマー０．１～１００質量部
を含有する樹脂組成物。
〔２〕全芳香族液晶ポリマーの結晶融解温度は２１０～２６０℃である、〔１〕に記載の樹脂組成物。
〔３〕曲げ弾性率は１０．０ＧＰａ以下である、請求項１または２に記載の樹脂組成物。
〔４〕シャルピー衝撃強度は１．０ｋＪ／ｍ ^２ 以上である、〔１〕～〔３〕のいずれかに記載の樹脂組成物。
〔５〕液晶ポリマーは、式（Ｉ）～（ＩＶ）
［化１］

［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：
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〕～〔４〕のいずれかに記載の樹脂組成物。
〔６〕Ａｒ _１ およびＡｒ _２ は、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、〔５〕に記載の樹脂組成物。
〔７〕〔１〕～〔６〕のいずれかに記載の樹脂組成物から構成される成形品。

Preferred embodiments of the invention include the following.
[1] 100 parts by mass of ethylene-vinyl alcohol copolymer resin, and
0.1 to 100 parts by mass of a wholly aromatic liquid crystal polymer having a crystal melting temperature of 260° C. or less
A resin composition containing
[2] The resin composition according to [1], wherein the wholly aromatic liquid crystal polymer has a crystal melting temperature of 210 to 260°C.
[3] The resin composition according to [1] or [2], which has a bending elastic modulus of 10.0 GPa or less.
[4] The resin composition according to any one of [1] to [3], which has a Charpy impact strength of 1.0 kJ/m ² or more.
[5] The liquid crystal polymer has formulas (I) to (IV)
[Chemical 1]

[In the formula,
Ar ₁ and Ar ₂ each represent one or more divalent aromatic groups, and p, q, r and s respectively represent the composition ratio of each repeating unit in the wholly aromatic liquid crystalline polyester ( %) and satisfies the following conditions:
0.5≦p/q≦2.5
2≦r≦15, and
2≦s≦15]
The resin composition according to any one of [1] to [4], which is a wholly aromatic liquid crystal polyester containing a repeating unit represented by:
[6] Ar ₁ and Ar ₂ are, independently of each other, represented by formulas (1) to (4)
[Chemical 2]

The resin composition according to [5], which contains one or more selected from the group consisting of aromatic groups represented by:
[7] A molded article composed of the resin composition according to any one of [1] to [6].

Claims (6)

100 parts by mass of an ethylene-vinyl alcohol copolymer resin, and 0.1 to 100 parts by mass of a wholly aromatic liquid crystal polymer having a crystal melting temperature of 260° C. or less ,
The liquid crystal polymer has formulas (I)-(IV)

[In the formula,
Ar ₁ and Ar ₂ each represent one or more divalent aromatic groups, and p, q, r and s respectively represent the composition ratio of each repeating unit in the wholly aromatic liquid crystalline polyester ( %) and satisfies the following conditions:
0.5≦p/q≦2.5
2≦r≦15, and
2≦s≦15]
A wholly aromatic liquid crystalline polyester containing a repeating unit represented by
Resin composition. The resin composition according to claim 1, wherein the wholly aromatic liquid crystal polymer has a crystal melting temperature of 210 to 260°C. 3. The resin composition according to claim 1, which has a flexural modulus of 10.0 GPa or less. 4. The resin composition according to claim 1, which has a Charpy impact strength of 1.0 kJ/m ² or more. Ar ₁ and Ar ₂ are, independently of each other, the formulas (1)-(4)

The resin composition according to any one of claims 1 to 4, comprising one or more selected from the group consisting of aromatic groups represented by A molded article composed of the resin composition according to any one of claims 1 to 5 .