JP2002338771A - Resin composition and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which is excellent in stretchability and pinhole resistance and gives a multilayer stretched film excellent in gas barrier properties after flexural fatigue; and a laminate prepared by using the composition. SOLUTION: This resin composition contains a saponified ethylene/vinyl acetate copolymer, a polyamide resin having a melting point of 160 deg.C or lower, and a polyamide resin having a melting point higher than 160 deg.C. The laminate is prepared by forming a thermoplastic resin layer on at least one side of a layer containing the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition using a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) and a laminate thereof, and more particularly to stretchability and pinhole resistance. The present invention relates to a resin composition capable of obtaining a molded article having improved gas barrier properties after bending fatigue when formed into a multilayer stretched film, and a laminate using the resin composition.

[0002]

2. Description of the Related Art In general, EVOH is excellent in transparency, gas barrier property, fragrance retention, solvent resistance, oil resistance and the like.
It is used for various packaging materials such as industrial chemical packaging materials and agricultural chemical packaging materials. Such EVOH is often subjected to heat stretching treatment for the purpose of improving its mechanical strength and the like, and the stretching performance is an important required performance. It becomes.

However, EVOH is inferior in heat drawability to thermoplastic resins such as polyolefin resins and polystyrene resins, and as a countermeasure, a blend of EVOH with a polyamide resin has been used.
For example, JP-A-63-114645 discloses EVO
A heat-stretched multilayer structure having a resin composition layer comprising H and an aliphatic copolymerized nylon is described. As such a resin composition, specifically, a blend of EVOH and a copolymerized nylon having a melting point of 155 ° C. is disclosed. ing.

[0004]

However, when the present inventors examined the above blend in detail,
Although the effect of improving the heat-stretching formability is recognized to some extent, for example, when the single-layer film is stretched at a relatively low temperature of about 60 to 80 ° C., unevenness in thickness and the like may be observed. In some cases, the improvement effect of the film may not be sufficiently exhibited, and further improvement is desired.In addition, the pinhole resistance at the time of bending fatigue when the film is formed and the gas barrier property due to the bending fatigue when applied to a multilayer stretched film application. It has been found that this has been reduced, and improvement in this respect is also desired. That is,
It is an object of the present invention to improve stretchability at low temperatures and to improve pinhole resistance and gas barrier properties during bending fatigue.

[0005]

Accordingly, the present inventor has conducted intensive studies in view of the present situation, and as a result, has found that EVOH
It has been found that a resin composition containing (A), a polyamide resin (B) having a melting point of 160 ° C. or less and a polyamide resin (C) having a melting point of more than 160 ° C. meets the above-mentioned object, and the present invention Was completed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The EVOH (A) used in the present invention is not particularly limited, but has an ethylene content of 10 to 70.
Mol% (furthermore, 20 to 60 mol%, especially 25 to 50 mol%), and a saponification degree of 90 mol% or more (furthermore, 95 mol%
When the ethylene content is less than 10 mol%, the gas barrier properties and melt moldability at high humidity are reduced. On the contrary, when the ethylene content exceeds 70 mol%, a sufficient gas barrier property is obtained. When the saponification degree is less than 90 mol%, the gas barrier properties, thermal stability, moisture resistance, etc. are undesirably reduced.

The EVOH has a melt flow rate (MFR) (210 ° C., load 2160 g) of 0.5 to 0.5.
100 g / 10 min (more preferably 1 to 50 g / 10 min, particularly 3 to 35 g / 10 min) is preferred. If the MFR is smaller than the above range, the extruder becomes in a high torque state during molding and extrudes. If the working becomes difficult, and if it is larger than the above range, the thickness accuracy of the obtained molded product is undesirably reduced.

The EVOH (A) is obtained by saponifying an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer can be produced by any known polymerization method, for example, solution polymerization, suspension polymerization, It is produced by emulsion polymerization or the like, and saponification of an ethylene-vinyl acetate copolymer can be performed by a known method.

In the present invention, a copolymerizable ethylenically unsaturated monomer may be copolymerized as long as the effects of the present invention are not impaired. Examples of such a monomer include propylene and 1-butene. , Olefins such as isobutene, acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid,
Unsaturated acids such as (anhydride) maleic acid and (anhydride) itaconic acid or salts thereof, mono- or dialkyl esters having 1 to 18 carbon atoms, acrylamide, 1 to 1 carbon atoms
8, acrylamides such as N-alkylacrylamide, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or a salt thereof, acrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, methacrylamide, having 1 to 18 carbon atoms Methacrylamides such as N-alkylmethacrylamide, N, N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid or a salt thereof, methacrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, N-vinylpyrrolidone N-vinylamides such as, N-vinylformamide and N-vinylacetamide;
Vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ethers and alkoxyalkyl vinyl ethers, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and vinyl bromide And vinylsilanes such as trimethoxyvinylsilane, allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, trimethyl- (3-acrylamido-3-dimethylpropyl)-
Examples thereof include ammonium chloride and acrylamide-2-methylpropanesulfonic acid. Further, post-modification such as urethanization, acetalization, and cyanoethylation may be performed as long as the gist of the present invention is not impaired.

It is also possible to use two or more different EVOHs as the EVOH (A1). In this case, the ethylene content is 5 mol% or more (further 5 to 25 mol%,
In particular, 8 to 20 mol%) and / or the degree of saponification is 1 mol% or more (further 1 to 15 mol%, particularly 2 to 10 mol%).
Mol%), and / or by using a blend of EVOH having an MFR ratio of 2 or more (more preferably 3 to 20, especially 4 to 15), it is possible to further increase flexibility and heat while maintaining gas barrier properties. This is useful because the moldability, film forming stability and the like are improved. The method for producing two or more different EVOHs (blends) is not particularly limited.
A method of mixing each paste of VA and then saponifying, a method of mixing a mixed solution of alcohol or water and alcohol of each EVOH after saponification, and a method of melting and kneading after mixing each EVOH are exemplified.

In the present invention, the above EVOH (A)
The most characteristic feature is that a polyamide resin (B) having a melting point of 160 ° C. or less and a polyamide resin (C) having a melting point of more than 160 ° C. are blended. At 150 ° C, even 80-140 ° C
The preferred melting point of (C) is 180 to 280
° C, even 190-260 ° C.

Specific examples of these polyamide resins include polycapramide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-ω-aminononanoic acid (nylon 9), and polyundecaneamide (nylon 1).
1), polylauryl lactam (nylon 12), polyethylene diamine adipamide (nylon 26), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide ( Nylon 610), polyhexamethylene dodecamide (nylon 612), polyoctamethylene adipamide (nylon 8, 6), polydecamethylene adipamide (nylon 108), caprolactam / lauryl lactam copolymer (nylon 6/12 ), Caprolactam / ω-aminononanoic acid copolymer (nylon 6/9), caprolactam / hexamethylenediammonium adipate copolymer (nylon 6/66), lauryl lactam /
Hexamethylene diammonium adipate copolymer (nylon 12/66), ethylenediamine adipamide / hexamethylene diammonium adipate copolymer (nylon 26/66), caprolactam / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer Polymer (nylon 66/610), ethylene ammonium adipate / hexamethylene diammonium adipate / hexamethylene diammonium sebacate copolymer (nylon 6/66/610), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide, hexa Methylene isophthalamide / terephthalamide copolymers or their polyamide resins can be converted to aromatic amines such as methylenebenzylamine and meta-xylenediamine. Modified ones and m-xylylenediamine adipate, etc. can be mentioned, melting point 1
Those having a melting point of not higher than 160 ° C. can be used as the component (C) and those having a melting point of not higher than 60 ° C. can be used as the component (B).

Here, the melting point is measured by a differential scanning calorimeter (DSC).
Is the melting peak temperature (° C.) measured at a heating rate of 10 ° C./min.

The method for adjusting the melting point of the polyamide resin is not particularly limited. Industrially, it is preferable to use a copolymer having a specific ratio among the above polyamide resins. Not something.

Specific examples of the polyamide resin as the component (B) include nylon 6/12, nylon 6/69,
Nylon 6/66/610, Nylon 6/66/610
/ 12, nylon 6/66/610/11 and aromatic amine modified products, and specific commercial names are "Amilan CM4000", "Amilan CM8000", "Amilan CM6541-X3". 』、
"Amilan CM831", "Amilan CM833" (all manufactured by Toray Industries), "Elvamide 8061", "Elvamide 8062S", "Elvamide 8066" (all manufactured by DuPont Japan), "Grillon CF6S", "Grillon CF62BS", "Grillon CA6E", "Grillon XE3381", "Grillon BM13SBG" (above,
Ems Japan), “UBE7128B”, “UB
E7028B "(all manufactured by Ube Industries, Ltd.).

Specific examples of the component (C) include nylon 6, nylon 66, nylon 6/66, nylon 6/12, MXD6, and the like. , "Grillon F34", "Grillon F40" (above, manufactured by EMS Japan), "Novamid 1020", "Novamid 2020", "Novamid 2420" (above, manufactured by Mitsubishi Engineering-Link Plastics),
"Amilan CM1021XF", "CM6021XF"
6, Amiran CM6541-X2, Amiran C
M6541-X4 "(all manufactured by Toray Industries, Inc.)," UBE10
15B "," UBE1022B "," UBE3035
U "," UBE2015 "(above, manufactured by Ube Industries),
"MX Nylon" (manufactured by Mitsubishi Gas Chemical Company) and the like.

Further, the polyamide resin (B) was measured using a differential scanning calorimeter (DSC) (heating rate 10 ° C./mi).
n) The heat of fusion (ΔH) to be performed is preferably 80 J / g or less (more preferably 5 to 70 J / g, particularly 10 to 60 J / g). When the heat of fusion (ΔH) exceeds 80 J / g, However, it is not preferable because the low-temperature heat-stretching moldability tends to decrease. The heat of fusion (ΔH) of the polyamide resin is 80 J /
g or less is not particularly limited, but is industrially preferable by controlling the degree of polymerization in the polyamide resin, molecular weight, molecular weight distribution, content of low molecular weight components, water content, residual monomer content, and the like. Can be done.

Further, the melt flow rate (MFR) of the polyamide resin (B) (210 ° C., load 2160 g)
g) is 1 to 100 g / 10 minutes (further 3 to 80 g / 1
0 minutes, especially 5 to 50 g / 10 minutes). When the melt flow rate is out of the range, the low-temperature heat drawability tends to decrease, which is not preferable. The method for adjusting the MFR of the polyamide resin to the above range is not particularly limited. However, industrially, the degree of polymerization, the molecular weight, the molecular weight distribution, the content of the low molecular weight component, the water content, the residual monomer amount, and the like of the polyamide resin are determined. It can be suitably performed by controlling. The polyamide resin (B) or (C) has a structure, a composition, a molecular weight (MFR),
Two or more polyamide resins having different molecular weight distributions can be used in combination.

The resin composition of the present invention comprises the above-mentioned (A)
To (C), the content ratio of which is not particularly limited, but the content weight ratio of (A) and (B) (A /
B) is 50/50 to 99/1 (further 60/40 to 9
7/3, especially 70/30 to 95/5). When the weight ratio is smaller than 50/50, the gas barrier properties may be insufficient, and when the weight ratio is larger than 99/1, on the other hand. It is not preferable because the low-temperature heat-stretching moldability may be insufficient.

The content ratio of (C) is 1 to 5 with respect to 100 parts by weight of the total amount (A + B) of (A) and (B).
0 parts by weight (more preferably 2 to 30 parts by weight, particularly 3 to 15 parts by weight). If the content is less than 1 part by weight, the pinhole resistance tends to decrease.
If the amount exceeds 0 parts by weight, the obtained heat-stretched molded product tends to have reduced gas barrier properties, which is not preferable.

Further, the content weight ratio of (B) and (C) (B
/ C) is 50 / 50-99 / 1 (further 55 / 45-45).
98/2, especially 60/40 to 95/5), and when the content ratio is less than 50/50, the low-temperature heat drawability becomes insufficient, and when the content ratio exceeds 99/1, the pinhole resistance decreases. There is a tendency and it is not preferable.

The resin composition comprising the components (A) to (C) may be blended with the components (A) to (C). Specifically, the components (A) to (C) A method of melt-kneading after mixing all at once, a method of melt-kneading the components (A) and (B) and then a further melt-kneading by adding the component (C), and a melt-kneading of the components (A) and (C) After adding (B) component, and further melt-kneading,
A method in which the component (A) is added after the components (B) and (C) are melt-kneaded, and the mixture is further melt-kneaded, (A) to (C).
A method of uniformly dissolving and mixing the components in a solvent capable of dissolving the components and then removing the solvent can be mentioned, and the method preferably used for production is used.

For the above-mentioned melt-kneading, a known method can be adopted. For example, Lower Ruder,
Known kneading apparatuses such as an extruder, a mixing roll, a Banbury mixer, a plast mill and the like can be used, and usually at 150 to 300 ° C (more preferably 180 to 280 ° C).
It is preferable to perform melt kneading for about 1 minute to 1 hour, and it is advantageous to use an extruder such as a single-screw extruder or a twin-screw extruder industrially, and if necessary, a vent suction device, a gear pump device, It is also preferable to provide a screen device or the like.
In particular, in order to remove moisture and by-products (such as pyrolyzed low-molecular-weight products), the extruder is provided with one or more vent holes to suck under reduced pressure or to prevent oxygen from being mixed into the extruder. By continuously supplying an inert gas such as nitrogen into the hopper, it is possible to obtain a high-quality resin composition in which thermal coloring and thermal deterioration are reduced.

Thus, the resin composition of the present invention comprising (A) to (C) is obtained. In the resin composition, acids such as acetic acid, boric acid, phosphoric acid and the like, and alkali metals and alkalis thereof are contained. Earth metal, may also contain metal salts such as transition metals, heat stability of the resin composition, long-run moldability,
It is preferable from the viewpoint of improving the interlayer adhesiveness with the adhesive resin and the heat-stretching moldability when the laminate is formed. In particular, an alkali metal salt or an alkaline earth metal salt is preferably used because of its excellent effect.

Examples of such metal salts include acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, oleic acid, such as sodium, potassium, calcium, and magnesium.
Metal salts of organic acids such as behenic acid and the like, and inorganic acids such as sulfuric acid, sulfurous acid, carbonic acid, phosphoric acid and the like can be mentioned, and preferred are acetate, phosphate and hydrogen phosphate. The content of the metal salt is 5 to 1000 p in terms of metal with respect to the resin composition.
pm (further 10 to 500 ppm, especially 20 to 300 ppm
ppm), and the content is 5 pp
If less than m, the content effect may not be sufficiently obtained,
Conversely, if it exceeds 1000 ppm, the appearance of the obtained molded product is undesirably deteriorated. When two or more kinds of alkali metal and / or alkaline earth metal salts are contained in the resin composition, the total amount is preferably in the above range. Further, when boric acid is contained, 10 to 10000 ppm (more preferably 20 to 2000 ppm) in terms of boron.
ppm, particularly preferably 50 to 1000 ppm).

There is no particular limitation on the method for incorporating the acids or their metal salts into the resin composition, and the resin composition may be previously contained in (A) or may be simultaneously contained during the blending of (A) to (C). , (A) to (C) when blended, or (A) to (C) after blending the resin composition, or (B) or (C) in advance. They can be contained, or these methods can be combined. In order to obtain the effects of the present invention more remarkably, a method in which EVOH (A) is contained in advance is preferable in terms of excellent dispersibility of acids and metal salts thereof.

The method of preliminarily incorporating EVOH (A) into EVOH (A) is as follows: a) Contacting a porous precipitate of EVOH having a water content of 20 to 80% by weight with an aqueous solution of an acid or a metal salt thereof to form an acid or the like. A method of drying after containing a metal salt,
B) After making the homogeneous solution (water / alcohol solution, etc.) of EVOH contain acids and their metal salts, extrude them into a coagulating solution in the form of strands, and then cut the obtained strands into pellets, which are further dried. C) EVOH
And kneading with an extruder or the like after batchwise mixing and acid or metal salt thereof, and d) during the production of EVOH, the alkali (sodium hydroxide, potassium hydroxide, etc.) used in the saponification step is converted to acetic acid. And the amount of remaining acids such as acetic acid and by-produced alkali metal salts such as sodium acetate and potassium acetate are adjusted by washing with water. In order to obtain the effect of the present invention more remarkably, the method a), a) or d), which is excellent in dispersibility of acids and metal salts thereof, is preferable.

Further, in the present invention, a saturated aliphatic amide (for example, stearic acid amide), an unsaturated fatty acid amide (for example, oleic acid amide, etc.), Fatty acid amides (e.g., ethylene bisstearic acid amide, etc.), fatty acid metal salts (e.g., calcium stearate, magnesium stearate, zinc stearate, etc.), low molecular weight polyolefins (e.g., low molecular weight polyethylene having a molecular weight of about 500 to 10,000, or low molecular weight Lubricants such as polypropylene), inorganic salts (eg, hydrotalcite), plasticizers (eg, aliphatic polyhydric alcohols such as ethylene glycol, glycerin, hexanediol, etc.), oxygen absorbers [eg, as inorganic oxygen absorbers, Reduced iron powders, as well as water-absorbing substances and electricity And the like, aluminum powder, potassium sulfite, titanium oxide photocatalyst, etc., as organic compound-based oxygen absorbers, ascorbic acid, furthermore, fatty acid esters and metal salts thereof, hydroquinone, gallic acid, hydroxyl-containing phenol aldehyde resin, etc. Of a transition metal with a nitrogen-containing compound such as polyhydric phenols, bis-salicylaldehyde-imine cobalt, tetraethylene pentamine cobalt, cobalt-Schiff base complex, porphyrins, macrocyclic polyamine complex, and polyethylene imine-cobalt complex. Coordination body, terpene compound, reactant of amino acids and hydroxyl group-containing reducing substance, triphenylmethyl compound, etc., as a high molecular oxygen absorber,
Coordination conjugate of a nitrogen-containing resin and a transition metal (for example, MXD
A combination of nylon and cobalt), a blend of a tertiary hydrogen-containing resin and a transition metal (for example, a combination of polypropylene and cobalt), a blend of a resin containing a carbon-carbon unsaturated bond and a transition metal (for example, a combination of polybutadiene and cobalt) ), Photo-oxidatively degradable resin (for example, polyketone, etc.),
An anthraquinone polymer (eg, polyvinyl anthraquinone) and the like, and further, a photoinitiator (eg, benzophenone), a peroxide supplement (eg, a commercially available antioxidant), and a deodorant (eg, activated carbon) are added to these compounds. Additives, etc.], heat stabilizers, light stabilizers, antioxidants, ultraviolet absorbers, colorants, antistatic agents, surfactants, antibacterial agents, antiblocking agents (eg, talc fine particles, etc.), slip agents (eg, Amorphous silica, etc.), fillers (eg, inorganic fillers, etc.), and other resins (eg, polyolefins, polyesters, etc.) may be blended.

The resin composition of the present invention thus obtained is
It is excellent in heat stretch moldability, and has excellent pinhole resistance and gas barrier properties after bending fatigue of a stretched film, and of course, it can be used as a single layer for various applications, but is also useful as a laminate, and is particularly useful. It is preferable to use as a laminate obtained by laminating a thermoplastic resin layer on at least one side of a layer made of the resin composition, and a water-resistant, mechanical property, a laminate suitable for practical use with heat sealability or the like is provided. can get.

Hereinafter, such a laminate will be described. In producing the laminate, another substrate (such as a thermoplastic resin) is laminated on one or both sides of the resin composition of the present invention. The laminating method includes, for example, the resin composition of the present invention. Method of melt-extruding and laminating another substrate on a film, sheet or the like of the present invention, conversely, a method of melt-extruding and laminating the resin composition on another substrate, and a method of co-extruding the resin composition with another substrate An organic titanium compound, an isocyanate compound, and a resin composition (layer) of the present invention and another substrate (layer).
A dry lamination method using a known adhesive such as a polyester compound or a polyurethane compound may be used. The melt molding temperature during the above melt extrusion is 150 to
It is often selected from the range of 300 ° C.

As such another substrate, a thermoplastic resin is useful, and specifically, linear low density polyethylene, low density polyethylene, ultra low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-acetic acid Vinyl copolymer, ionomer, ethylene-propylene (block or random) copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer Polymer, polypropylene, propylene-α-olefin (α-olefin having 4 to 20 carbon atoms) copolymer, homo- or copolymer of olefin such as polybutene, polypentene, polymethylpentene, or homo- or copolymer of these olefins Graft modification of polymer with unsaturated carboxylic acid or its ester Polyolefin resins, polyester resins, polyamide resins (including copolymerized polyamides), polyvinyl chloride, polyvinylidene chloride, acrylic resins, polystyrene resins, etc.
Vinyl ester resins, polyester elastomers, polyurethane elastomers, chlorinated polyethylene, chlorinated polypropylene, aromatic or aliphatic polyketones, polyalcohols obtained by further reducing these, and other EVOHs. From the viewpoint of practicability such as body characteristics (particularly strength and appearance), polypropylene, ethylene-propylene (block or random) copolymer, polyamide, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, polyethylene terephthalate (PE
T) and polyethylene naphthalate (PEN) are preferably used, and particularly, polypropylene, ethylene-propylene (block or random) copolymer, and polyethylene having excellent stretchability, transparency, and flexibility are preferable.

Further, when a molded product such as a film or sheet of the resin composition of the present invention is extrusion-coated with another substrate, or when a film or sheet of another substrate is laminated with an adhesive, such a case is required. As the substrate, any substrate (paper, metal foil, uniaxially or biaxially stretched plastic film or sheet and inorganic deposits thereof, woven fabric, nonwoven fabric, metal flocculent, woody, etc.) other than the above-mentioned thermoplastic resin can be used. Can be used.

The layer structure of the laminate is such that a layer of the resin composition of the present invention is a (a ₁ , a ₂ ,...) And another substrate, for example, a thermoplastic resin layer is b (b ₁ , b _2). when the...), a film, a sheet, if a bottle shape, not only the double layer structure of a / b, b / a / b, a / b / a, a 1 / a 2 / b, a /
_{b 1 / b 2, b 2} / b 1 / a / b 1 / b 2, b 2 / b 1 / a / b
_{1 / a / b 1 / b} 2 , etc. Any combination is possible, furthermore, when the regrind layer comprising at least a resin composition and a mixture of thermoplastic resin and R, b / R / a,
b / R / a / b, b / R / a / R / b, b / a / R / a
/ B, b / R / a / R / a / R / b, etc. In the filament form, a and b are bimetal type, core (a) -sheath (b) type, core (b) Any combination such as a sheath (a) type or an eccentric core-sheath type is possible.

In the above-mentioned layer structure, an adhesive resin layer can be provided between the respective layers as required, and various adhesive resins can be used. It is preferable in that a laminate excellent in the above properties can be obtained. Although it depends on the type of the resin b and cannot be said unconditionally, an unsaturated carboxylic acid or an anhydride thereof is added to an olefin-based polymer (the above-mentioned olefin alone or copolymer). Examples include a modified olefin polymer containing a carboxyl group obtained by chemically binding by a reaction or a graft reaction, and specifically, maleic anhydride graft-modified polyethylene, maleic anhydride graft-modified polypropylene, Maleic anhydride graft-modified ethylene-propylene (block or random) copolymer, maleic anhydride graft-modified Len - ethyl acrylate copolymer, maleic anhydride graft-modified ethylene anhydride - one or a mixture of two or more species selected from vinyl acetate copolymers and the like as preferred. At this time, the amount of the unsaturated carboxylic acid or the anhydride thereof contained in the thermoplastic resin is preferably 0.001 to 3% by weight, more preferably 0.01 to 1% by weight, and particularly preferably 0.03% by weight. ~ 0.5
% By weight. If the amount of modification in the modified product is small, the adhesiveness may be insufficient, and if it is too large, a crosslinking reaction may occur and moldability may deteriorate, which is not preferable. These adhesive resins include the resin composition of the present invention and other EVs.
It is also possible to blend rubber / elastomer components such as OH, polyisobutylene and ethylene-propylene rubber, as well as the resin of the layer b. In particular, by blending a polyolefin resin different from the base polyolefin resin of the adhesive resin, the adhesiveness may be improved, which is useful.

The thickness of each layer of the laminate cannot be specified unconditionally depending on the layer constitution, the type of b, the use and the form of the container, the required physical properties, etc., but usually the layer a has a thickness of 5 to 500 μm (further 1 μm).
0 to 200 μm), the b layer is 10 to 5000 μm (further 30 to 1000 μm), and the adhesive resin layer is 5 to 400 μm
(Further 10 to 150 μm). If the thickness of the layer a is less than 5 μm, the gas barrier properties are insufficient, and the thickness control becomes unstable. On the other hand, if the thickness exceeds 500 μm, the stretchability and pinhole resistance are poor, and it is not economically preferable. When the thickness is less than 5000 μm, the rigidity is insufficient. On the contrary, when the thickness exceeds 5000 μm, the weight increases, and it is not economical and is not preferable. When the adhesive resin layer is less than 5 μm, the interlayer adhesion becomes insufficient and the thickness control becomes unstable, Conversely, if it exceeds 400 μm, the weight increases,
And it is not economical and not preferable.

The laminate is used as it is in various shapes. However, in order to further improve the physical properties of the laminate and to mold it into a desired container shape, it is preferable to perform a heat stretching treatment. . Here, the heat-stretching treatment means to heat a film, a sheet, and a parison-like laminate that are uniformly heated by a chuck, a plug, a vacuum force, a pneumatic force, a blow, or the like to form a cup, tray, tube, bottle, or film. Means the operation of molding uniformly, and for such stretching,
Either uniaxial stretching or biaxial stretching may be performed. Stretching at the highest possible magnification provides better physical properties, and does not cause pinholes, cracks, stretching unevenness, uneven thickness, delamination, etc. during stretching, and gas barrier properties. This gives a stretch molded product excellent in quality.

As the stretching method, any of a roll stretching method, a tenter stretching method, a tubular stretching method, a stretch blow method, vacuum forming, pressure forming, vacuum pressure forming, etc., which have a high draw ratio, can be employed. In the case of biaxial stretching, simultaneous biaxial stretching method,
Any of the sequential biaxial stretching methods can be adopted. The stretching temperature is selected from the range of 60 to 170 ° C, preferably about 80 to 160 ° C.

After completion of the stretching, it is also preferable to carry out heat setting. Heat setting can be carried out by known means,
80-170 while keeping the stretched film under tension.
C., preferably at 100 to 160.degree. C. for about 2 to 600 seconds. Further, when used for heat shrink packaging of raw meat, processed meat, cheese, etc., the product film is not heat-set after stretching, and the raw meat, processed meat, cheese, etc. are stored in the film, 50-130 ° C, preferably 7
At 0 to 120 ° C., heat treatment is performed for about 2 to 300 seconds,
The film is heat-shrinked and tightly packaged.

The shape of the thus obtained laminate may be any shape, and examples thereof include a film, a sheet, a tape, a cup, a tray, a tube, a bottle, a pipe, a filament, and an extrudate having a modified cross section. In addition, the obtained laminate is subjected to heat treatment, cooling treatment, rolling treatment, printing treatment, dry lamination treatment, solution or melt coating treatment, if necessary,
Bag making, deep drawing, box processing, tube processing, split processing, and the like can be performed.

Containers such as cups, trays, tubes, bottles, etc., and bags and lids made of stretched films obtained as described above are not only general foods, but also seasonings such as mayonnaise and dressings, and fermented foods such as miso. , Salad oils and other fat foods, beverages, cosmetics, pharmaceuticals, detergents, cosmetics, industrial chemicals,
Although useful as various containers such as agricultural chemicals and fuels, the laminate of the present invention is particularly useful for packaging bags of miso, pickles, bonito, confectionery, noodles, peanuts, cigarettes and the like, raw meat, processed meat products (ham, Shrink wrapping film for bacon, wiener, etc., cup-shaped container for semi-solid foods and seasonings such as jelly, pudding, yogurt, mayonnaise, miso, etc .; It is useful for heat stretch molding containers such as tray-shaped containers.

[0042]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

For the measurement of the melting point of the polyamide resin, a differential scanning calorimeter (“DSC-
7 ") at a heating rate of 10 ° C./min. The boric acid content in EVOH was measured by melting EVOH with alkali and quantifying boron by ICP emission spectroscopy. Further, the measurement of the alkali metal content was carried out by dissolving the EVOH in an aqueous solution of hydrochloric acid after incineration and quantifying the alkali metal by atomic absorption spectrometry.

Example 1 EVOH [Ethylene content 34 mol%, saponification degree 99.
5 mol%, MFR 4.0 g / 10 min (210 ° C., load 2
160 g), containing 0.2% boric acid, sodium acetate 40
0 ppm] (A) 85 parts, polyamide resin [M
"Guriron CF6S" manufactured by SJAPAN, nylon 6/1
2, copolymer, density 1.05 g / cm^ThreeMelting point 133
° C, ΔH 51 J / g, MFR 18 g / 10 min (210
° C, load 2160g)] (B) 15 parts and polyamide type
Resin [Mitsubishi Engineering Plastics "NO"
VAMID 1020 ", nylon 6, density 1.14 g
/ Cm ^Three] (C) 10 parts with a twin screw extruder under the following conditions
After melt-kneading, the resin composition of the present invention [boron 300 pp
m, sodium 120 ppm).

[Melting Pelletizing Condition by Twin Screw Extruder] Screw inner diameter 30 mm (L / D = 30) Screw shape Screen mesh having a 100 mm kneading disk in the compression part 90/90 mesh Screw rotation speed 150 rpm Vent hole Reduced pressure suction Execution Nitrogen gas was supplied in the hopper and replaced. Extrusion temperature C1: 190 ° C C2: 200 ° C C3: 210 ° C C4: 220 ° C C5: 220 ° C AD: 210 ° C D: 210 ° C

The following evaluation was performed using the resin composition obtained above.

(Stretchability) Using the resin composition obtained above, a single-screw extruder was used to form a film under the following conditions to obtain a film having a thickness of 5 mm.
After obtaining an unstretched film of 0 μm, the film is simultaneously biaxially stretched at a stretching speed of 30 mm / sec at 70 ° C. using a biaxial stretching apparatus to obtain a stretched film (three times vertically and three times horizontally). Was.

[Film forming conditions by single screw extruder] Screw inner diameter 40 mm L / D 28 Screw compression ratio 3.2 T die Coat hanger type Die width 450 mm Extrusion temperature C1: 190 ° C H: 210 ° C C2: 210 ° C D : 210 ° C C3: 220 ° C C4: 220 ° C

The thickness unevenness of the obtained stretched film (approximately 20 cm square at the center of the film) was measured with a digital micrometer (“M-30” manufactured by Sony Corporation) at 20 points at 1 cm intervals in the MD and TD. It measured in the direction and evaluated according to the following criteria.・ ・ ・: The thickness unevenness with respect to the average thickness is less than ± 10% ・ ・ ・: 〃 ± 10 to less than 20% △: 〃 ± 20% or more ×: The film breaks at the time of stretching (measure the thickness) Z)

(Pinhole Resistance) The unstretched film (cut to A4 size) obtained above was used at 23 ° C. and 50% RH using a gelbo flex tester (manufactured by Rigaku Corporation).
After the reciprocating motion of 440 ° twist (3.5 inches) + straight movement (2.5 inches) was repeated 200 times in the atmosphere described above, the number of pinholes generated in the film was examined. The evaluation was based on criteria. The number of pinholes was measured by applying ink to the surface of the film and exuding the ink to the opposite side. ◎ ・ ・ ・ 0 pieces ○ ・ ・ ・ 1-3 pieces △ ・ ・ ・ 4-10 pieces × ・ ・ ・ 11 pieces or more

(Gas Barrier Property) The resin composition (a) obtained above, a polyolefin-based resin [Novatech FL6CK, PP manufactured by Nippon Polychem Co., Ltd.] (b) and an adhesive resin [Modick-AP manufactured by Mitsubishi Chemical Corporation] P-513
V ", maleic anhydride-modified PP] (c) is supplied to a co-extrusion multilayer film forming apparatus, and (b) / (c) / (a) / (c) /
(B) = 150 μm / 30 μm / 60 μm / 30 μm /
A laminate having a layer thickness configuration of 150 μm was obtained, and the obtained laminate was subjected to 100 mm / sec using a biaxial stretching apparatus.
Simultaneous biaxial stretching was performed at a stretching speed of c to obtain a multilayer stretched film (5 times long, 5 times wide). Using a gelbo flex tester (manufactured by Rigaku Corporation), the obtained multilayer stretched film was twisted 440 ° (3.5 inches) + straight (2.5 inches) in an atmosphere of 23 ° C. and 50% RH. After repeating reciprocating motion 1000 times, the oxygen permeability (cc) of the multilayer stretched film was measured at 23 ° C. and 50% RH using an oxygen permeability measuring device (“OXTRAN10 / 50” manufactured by MOCON). / m ² · day · atm).

Example 2 In Example 1, as the component (A), the ethylene content was 29 mol%, the saponification degree was 99.6 mol%, and the MFR was 8.0 g.
/ 10 min (210 ° C., load 2160 g), boric acid 0.1
Evaluation was performed in the same manner except that EVOH containing 3%, 400 ppm of sodium acetate, and 90 ppm of potassium acetate was used. The boron content in the resin composition was 200 ppm, and the sodium content was 100 pp.
The m and potassium contents were 30 ppm.

Example 3 In Example 1, as the component (A), the ethylene content was 38 mol%, the saponification degree was 99.6 mol%, and the MFR was 3.0 g.
/ 10 min (210 ° C., load 2160 g), boric acid 0.1
3% content, 336ppm sodium acetate content, phosphoric acid 2
Contains 92 ppm of sodium hydrogen, 230 calcium acetate
The same procedure was performed except that EVOH containing ppm was used, and the same evaluation was performed. The boron content in the resin composition is 2
00 ppm, the sodium content was 95 ppm, and the calcium content was 50 ppm.

Example 4 In Example 1, "Amilan CM8000" manufactured by Toray Co., Ltd. [nylon 6/66/610/12] was used as the component (B).
A density of 1.12 g / cm ³ , a melting point of 131 ° C.
ΔH40J / g, MFR 25 g / 10 min (210 ° C., load 2160 g)], and the same evaluation was performed.

Example 5 In Example 1, "Grillon CA6E" (nylon 6/12 copolymer, density 1.06 g / cm ³ , melting point 124 ° C., ΔH 39
J / g, MFR 26g / 10 min (210 ° C, load 216
0g)], and evaluated similarly.

Example 6 In Example 1, "Amiran CM6541-X3" [a copolymer of nylon 6/12, density 1.11 g / cm ³ , melting point 135 ° C., ΔH 40
J / g, MFR 12 g / 10 min (210 ° C., load 216
0g)], and evaluated similarly.

Example 7 In Example 1, "Novamid 2020" (a copolymer of nylon 6/66, density 1.13 g / cm ³ , manufactured by Mitsubishi Engineering-Plastics Corporation) was used as the component (C).
[Melting point 193 ° C.], and the same evaluation was performed.

Example 8 In Example 1, "Amilan CM6541-X4" (a copolymer of nylon 6/12, density 1.10 g / cm ³ , melting point 196 ° C.) manufactured by Toray Co., Ltd. was used as the component (C). The same procedure was carried out except for the evaluation, and the same evaluation was performed.

Example 9 Example 9 was the same as Example 1, except that "UBE2015B" (a copolymer of nylon 66, density 1.14 g / cm ³ , melting point 255 ° C.) manufactured by Ube Industries, Ltd. was used as the component (C). And evaluated similarly.

Example 10 The procedure of Example 1 was repeated except that the contents of the components (A) and (B) were changed to 90 parts and 10 parts, respectively.

Example 11 The procedure of Example 1 was repeated, except that the contents of the components (A) and (B) were changed to 70 parts and 30 parts, respectively.

Example 12 The procedure of Example 1 was repeated except that the content of the component (C) was changed to 15 parts, and the same evaluation was conducted.

Example 13 The same procedure as in Example 1 was carried out except that the content of the component (C) was changed to 3 parts, and the same evaluation was conducted.

Comparative Example 1 The procedure of Example 1 was repeated, except that the resin composition did not contain the component (B).

Comparative Example 2 The procedure of Example 1 was repeated, except that the resin composition did not contain the component (C).

Table 1 shows the evaluation results of the examples and comparative examples.

[Table 1] Pinhole resistance Stretchability Gas barrier property * Example 1 ◎ ◎ 4.7 〃 2 ◎ ◎ 4.4 〃 3 ◎ ◎ 6.9 〃 4 ◎ ◎ 5.3 ５ 5 ◎ ◎ 5 5.1 〃 6 ◎ ◎ 5.8 〃 7 ◎ ◎ 5.2 ８ 8 ◎ ◎ 5.0 〃 9 ◎ ◎ 5.6 〃 10 ◎ ◎ 4.4 〃 11 ◎ ◎ 5.1 〃 12 ◎ ◎ 5. 4 〃 13 ◎ ◎ 4.7 Comparative Example 1 △ ×> 200 △ 2 × △> 200 * The unit of gas barrier property is cc / m ² · day · atm

[0068]

EFFECT OF THE INVENTION The resin composition of the present invention comprises EVOH, a polyamide resin having a melting point of 160 ° C. or less, and a melting point of 160 ° C.
Because it contains a polyamide-based resin that exceeds 100%, it has excellent stretchability, pinhole resistance and gas barrier properties after bending fatigue when formed into a multilayer stretched film, and is suitable for various packaging applications (food, beverages, cosmetics, pharmaceuticals) , Industrial chemicals, agricultural chemicals, solvents, fuels, etc.), and is particularly useful as a laminate with a polyolefin resin.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F100 AK01B AK01C AK46A AK69A BA02 BA03 BA10B BA10C GB15 GB16 JA04A JB16B JB16C JD02 JK08 YY00A 4J002 BB221 BE031 CL002 CL003 CL013 CL032 CL033 CL050 EG001 EG026

Claims (6)

[Claims] 1. A saponified ethylene-vinyl acetate copolymer (A), a polyamide resin (B) having a melting point of 160 ° C. or less, and a polyamide resin (C) having a melting point exceeding 160 ° C. Characteristic resin composition. 2. The resin composition according to claim 1, wherein the polyamide resin (C) having a melting point higher than 160 ° C. is a polyamide resin having a melting point of 180 ° C. or higher. 3. The weight ratio (A / B) of the saponified ethylene-vinyl acetate copolymer (A) and the polyamide resin (B) having a melting point of 160 ° C. or less is 50/50 to 99/1.
The resin composition according to claim 1, wherein 4. A total amount of a saponified ethylene-vinyl acetate copolymer (A) having a polyamide resin (C) having a melting point exceeding 160 ° C. and a polyamide resin (B) having a melting point of 160 ° C. or less (B). A + B) 1 to 5 for 100 parts by weight
The resin composition according to any one of claims 1 to 3, wherein the amount is 0 part by weight. 5. A weight ratio (B / C) of a polyamide resin (B) having a melting point of 160 ° C. or less and a polyamide resin (C) having a melting point of more than 160 ° C. is 50/50 to 99/1.
The resin composition according to any one of claims 1 to 4, wherein 6. A laminate having a thermoplastic resin layer on at least one surface of a layer containing the resin composition according to claim 1.