JP2006124669A - Resin composition and multilayered structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition excellent in retort resistance at high temperatures, gas-barrier property and also pinhole resistance after retorted, and to provide a multilayered structure using the same. <P>SOLUTION: The resin composition comprises an ethylene-vinyl alcohol copolymer(A) and a polyamide resin(B), wherein the copolymer(A) contains structural units(1)(wherein, X is a linkage chain, being any linkage chain except ether linkage; and n is 0 or 1). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin composition comprising a novel ethylene-vinyl alcohol copolymer (A) and a polyamide-based resin (B), and a multilayer structure using the resin composition. The present invention relates to a resin composition and a multilayer structure excellent in retort property, gas barrier property, and pinhole resistance after retort.

In general, an ethylene-vinyl alcohol copolymer (hereinafter abbreviated as EVOH) is excellent in transparency, gas barrier properties, aroma retention, solvent resistance, oil resistance, and the like. It is used for various packaging materials such as materials, pharmaceutical packaging materials, industrial chemical packaging materials, and agricultural chemical packaging materials. However, when such food is sealed in such packaging materials and exposed to treatments such as boil sterilization and retort sterilization, that is, when exposed to high temperature and high humidity, EVOH is hydrophilic, a large amount of moisture Penetrates to generate voids in the EVOH and whitens to deteriorate the appearance or to deteriorate the barrier performance.
In order to overcome such drawbacks, it has been proposed to blend a polyamide resin with EVOH (see, for example, Patent Documents 1 and 2).
Japanese Patent Laid-Open No. 54-078749 Japanese Patent Laid-Open No. 54-077875

  However, when the present inventors examined the above method in detail, the appearance and gas barrier properties after performing boil sterilization and retort sterilization are improved, but pin resistance after performing boil sterilization and retort sterilization is improved. It is confirmed that the gas barrier property is lowered when bending is applied to the multilayer structure because the hole property is lowered, and the retort treatment at a high temperature such as 130 ° C. cannot be said to be sufficient in improving the retort resistance. A resin composition excellent in retort resistance and gas barrier property and having good pinhole resistance even after retort treatment and a multilayer structure using the same are desired.

（ここで、Ｘは結合鎖であってエーテル結合を除く任意の結合鎖で、Ｒ１〜Ｒ４はそれぞれ独立して任意の置換基であり、ｎは０または１を表す。）
また、本発明においては、上記の構造単位（１）が共重合によりＥＶＯＨの主鎖に導入されていること、上記の構造単位（１）の含有量が全ＥＶＯＨの０．１〜３０モル％であること、さらにホウ素化合物を含有すること等が好ましい実施態様である。 Therefore, as a result of intensive studies in view of the present situation, the present inventors have found that a composition containing EVOH (A) containing the following structural unit (1) and a polyamide resin (B) has the above object. The present invention has been completed by finding a match.

(Here, X is a bond chain and is an arbitrary bond chain excluding an ether bond, R1 to R4 are each independently an arbitrary substituent, and n represents 0 or 1.)
Moreover, in this invention, said structural unit (1) is introduce | transduced into the principal chain of EVOH by copolymerization, Content of said structural unit (1) is 0.1-30 mol% of all EVOH. In addition, it is preferable that a boron compound is contained.

  The resin composition of the present invention is composed of EVOH (A) and a polyamide-based resin (B), and EVOH (A) has a specific structural unit, so it has excellent retort resistance and gas barrier properties at high temperatures. A resin composition having good pinhole resistance even after the retort treatment and a multilayer structure using the resin composition can be obtained.

Hereinafter, the present invention will be specifically described.
EVOH (A) used in the present invention is EVOH containing the above structural unit (1), that is, a structural unit having a 1,2-glycol bond, and its molecular chain, 1,2-glycol bond structure, With respect to the bond chain (X) that bonds to any bond chain, any bond chain other than an ether bond can be applied, and the bond chain is not particularly limited, but includes alkylene, alkenylene, alkynylene, phenylene, naphthylene, and the like. hydrocarbons (these hydrocarbons fluorine, chlorine, may be substituted with halogen such as bromine, etc.) other, -CO -, - COCO -, - CO (CH 2) m CO -, - CO (C ₆ H ₄ ) CO—, —S—, —CS—, —SO—, —SO ₂ —, —NR—, —CONR—, —NRCO—, —CSNR—, —NRCS—, —NRNR—, —HPO _{4 , -Si (OR) 2 -,} - OSi (OR) 2 -, - OSi (OR) 2 O -, - Ti (OR) 2 -, - OTi (OR) 2 -, - OTi (OR) 2 O- , -Al (OR)-, -OAl (OR)-, -OAl (OR) O-, and the like, wherein R is each independently an arbitrary substituent, preferably a hydrogen atom or an alkyl group, Further, m is a natural number), and the ether bond is not preferable in that it is decomposed during melt molding and the heat melting stability of the resin composition is lowered. Of these, alkylene is preferable as the bond type from the viewpoint of heat melting stability, and further alkylene having 5 or less carbon atoms is preferable. In addition, a resin having a smaller number of carbon atoms is preferable in that the gas barrier performance of the resin composition is good, and a structure in which a 1,2-glycol bond structure in which n = 0 is directly bonded to a molecular chain is most preferable. . R1 to R4 are arbitrary substituents, and although not particularly limited, a hydrogen atom and an alkyl group are preferable in terms of easy availability of the monomer, and further, a hydrogen atom has good gas barrier properties of the resin composition. This is preferable.

  The production method of EVOH (A) used in the present invention is not particularly limited, but when a structural unit in which a 1,2-glycol bond structure is directly bonded to the main chain, which is the most preferable structure, is taken as an example, 3,4-diol A method of saponifying a copolymer obtained by copolymerizing -1-butene, a vinyl ester monomer and ethylene, obtained by copolymerizing 3,4-diacyloxy-1-butene, a vinyl ester monomer and ethylene A method of saponifying the obtained copolymer, a method of saponifying a copolymer obtained by copolymerizing 3-acyloxy-4-ol-1-butene, a vinyl ester monomer and ethylene, 4-acyloxy- Method for saponifying a copolymer obtained by copolymerizing 3-ol-1-butene, a vinyl ester monomer and ethylene, 3,4-diacyloxy-2 Method for saponifying a copolymer obtained by copolymerizing methyl-1-butene, vinyl ester monomer and ethylene, 2,2-dialkyl-4-vinyl-1,3-dioxolane, vinyl ester monomer and Examples include a method of saponifying a copolymer obtained by copolymerizing ethylene, and a method of saponifying and decarboxylating a copolymer obtained by copolymerizing vinyl ethylene carbonate, a vinyl ester monomer and ethylene. It is done. Moreover, as what has alkylene as a coupling chain (X), 4,5-diol- 1-pentene, 4, 5- diacyloxy-1-pentene, 4, 5-diol-3-methyl- 1-pentene, 4, Copolymers obtained by copolymerizing 5-diol-3-methyl-1-pentene, 5,6-diol-1-hexene, 5,6-diacyloxy-1-hexene and the like with vinyl ester monomers and ethylene The method of saponifying a copolymer obtained by copolymerizing 3,4-diasiloxy-1-butene, a vinyl ester monomer and ethylene is excellent in copolymerization reactivity. It is preferable to use 3,4-diacetoxy-1-butene as 3,4-diacyloxy-1-butene. A mixture of these monomers may also be used. Further, 3,4-diacetoxy-1-butane, 1,4-diacetoxy-1-butene, 1,4-diacetoxy-1-butane and the like may be contained as a small amount of impurities. Moreover, although such a copolymerization method is demonstrated below, it is not limited to this.

（ここで、Ｒはアルキル基であり、好ましくはメチル基である。）

（ここで、Ｒはアルキル基であり、好ましくはメチル基である。）

（ここで、Ｒはアルキル基であり、好ましくはメチル基である。）
なお、上記の（２）式で示される化合物は、イーストマンケミカル社から、上記（３）式で示される化合物はイーストマンケミカル社やアクロス社の製品を市場から入手することができる。 The 3,4-diol-1-butene is represented by the following formula (2), and the 3,4-diacyloxy-1-butene is represented by the following formula (3), 3-acyloxy-4-ol-1-butene. Represents the following formula (4), and 4-acyloxy-3-ol-1-butene is represented by the following formula (5).

(Here, R is an alkyl group, preferably a methyl group.)

(Here, R is an alkyl group, preferably a methyl group.)

(Here, R is an alkyl group, preferably a methyl group.)
The compound represented by the above formula (2) can be obtained from Eastman Chemical Co., and the compound represented by the above formula (3) can be obtained from Eastman Chemical and Acros.

  Examples of vinyl ester monomers include vinyl formate, vinyl acetate, vinyl propionate, vinyl valelate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, Examples thereof include vinyl versatate, among which vinyl acetate is preferably used.

  There are no particular limitations on the copolymerization of 3,4-diacyloxy-1-butene, vinyl ester monomer, and ethylene, and known methods such as bulk polymerization, solution polymerization, suspension polymerization, dispersion polymerization, or emulsion polymerization may be used. Although it can be employed, solution polymerization is usually performed.

The method for charging the monomer component at the time of copolymerization is not particularly limited, and any method such as batch charging, split charging, continuous charging, etc. may be employed.
In addition, as a method for introducing ethylene into the copolymer, ordinary ethylene pressure polymerization may be carried out, and the amount introduced can be controlled by the pressure of ethylene, and can be controlled according to the intended ethylene content. However, it is usually selected from the range of 25 to 80 kg / cm ² .

Examples of the solvent used for such copolymerization include usually lower alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone and methyl ethyl ketone, and methanol is preferably used industrially.
The amount of the solvent used may be appropriately selected in consideration of the chain transfer constant of the solvent in accordance with the degree of polymerization of the target copolymer. For example, when the solvent is methanol, S (solvent) / M ( Monomer) = 0.01 to 10 (weight ratio), preferably 0.05 to 7 (weight ratio).

In the copolymerization, a polymerization catalyst is used. Examples of the polymerization catalyst include known radical polymerization catalysts such as azobisisobutyronitrile, acetyl peroxide, benzoyl peroxide, lauryl peroxide, and t-butylperoxyneodeca Noate, t-butylperoxypivalate, α, α′bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxyneodecanoate, 1,1,3,3, -tetramethylbutylperoxyneodeca Peroxyesters such as noate, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-hexylperoxypivalate, di-n-propylperoxydi Carbonate, di-iso-propyl peroxydicarbonate], di-sec- Til peroxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethyl peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate, dimethoxybutyl peroxydicarbonate, di Peroxydicarbonates such as (3-methyl-3-methoxybutylperoxy) dicarbonate, diacyl peroxides such as 3,3,5-trimethylhexanoyl peroxide, diisobutyryl peroxide, lauroyl peroxide, etc. Examples include low temperature active radical polymerization catalysts, and the amount of polymerization catalyst used varies depending on the type of catalyst and cannot be determined unconditionally, but is arbitrarily selected according to the polymerization rate. For example, when azobisisobutyronitrile or acetyl peroxide is used, 10 to 2000 ppm is preferable with respect to the vinyl ester monomer, and 50 to 1000 ppm is particularly preferable.
Moreover, it is preferable to select the reaction temperature of a copolymerization reaction from the range of 40 degreeC-boiling point with the solvent and pressure to be used.

  In the present invention, it is preferable to make the resin composition obtained by allowing the hydroxylactone compound or hydroxycarboxylic acid to coexist with the above catalyst to make the color tone good (close to colorless). The compound is not particularly limited as long as it has a lactone ring and a hydroxyl group, and examples thereof include L-ascorbic acid, erythorbic acid, glucono delta lactone, etc., preferably L-ascorbic acid and erythorbic acid are used. Examples of the hydroxycarboxylic acid include glycolic acid, lactic acid, glyceric acid, malic acid, tartaric acid, citric acid, salicylic acid, and the like, and preferably citric acid is used.

  The amount of the hydroxylactone compound or hydroxycarboxylic acid used is 0.0001 to 0.1 parts by weight (more preferably 0.0005 to 100 parts by weight of vinyl ester monomer) in both batch and continuous systems. 0.05 part by weight, particularly 0.001 to 0.03 part by weight), and if the amount used is less than 0.0001 part by weight, the coexistence effect may not be sufficiently obtained. Exceeding parts by weight is not preferable because it results in inhibiting the polymerization of the vinyl ester monomer. In preparing such a compound in a polymerization system, there is no particular limitation, but usually an aliphatic ester (methyl acetate, ethyl acetate) containing a lower aliphatic alcohol (methanol, ethanol, propanol, tert-butanol, etc.) or a vinyl ester monomer. Etc.), a solvent such as water, or a mixed solvent thereof, and charged into the polymerization reaction system.

  In addition, what is necessary is just to determine the preparation amount of 3, 4- diacyloxy 1-butene etc. according to the introduction amount of said structural unit (1) desired.

  In the present invention, an ethylenically unsaturated monomer that can be copolymerized may be copolymerized as long as the effects of the present invention are not impaired during the above copolymerization. Examples of such monomers include propylene, 1 -Olefins such as butene and isobutene, unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid and (anhydrous) itaconic acid, or salts thereof, or those having 1 to 18 carbon atoms Mono- or dialkyl esters, acrylamide, N-alkyl acrylamide having 1 to 18 carbon atoms, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or its salt, acrylamidopropyldimethylamine or its acid salt or its quaternary salt, etc. Acrylamides, methacrylamide, N-alkyl methacryl having 1 to 18 carbon atoms Methacrylamides such as amide, N, N-dimethylmethacrylamide, 2-methacrylamide propanesulfonic acid or salts thereof, methacrylamide propyldimethylamine or acid salts thereof or quaternary salts thereof, N-vinylpyrrolidone, N-vinylformamide N-vinylamides such as 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, alkoxyalkyl vinyl ethers, vinyl chloride, vinylidene chloride , Vinyl halides such as vinyl fluoride, vinylidene fluoride, vinyl bromide, vinyl silanes, allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, trimethyl- (3- Acrylamide-3-dimethylpropyl) - ammonium chloride, acrylamido-2-methylpropanesulfonic acid, glycerol monoallyl ether, ethylene carbonate, and the like.

  Furthermore, N-acrylamidomethyltrimethylammonium chloride, N-acrylamidoethyltrimethylammonium chloride, N-acrylamidopropyltrimethylammonium chloride, 2-acryloxyethyltrimethylammonium chloride, 2-methacryloxyethyltrimethylammonium chloride, 2-hydroxy-3- Cationic group-containing monomers such as methacryloyloxypropyltrimethylammonium chloride, allyltrimethylammonium chloride, methallyltrimethylammonium chloride, 3-butenetrimethylammonium chloride, dimethyldiallylammonium chloride, diethyldiallylammonium chloride, acetoacetyl group-containing monomers And so on.

  Further, vinyl silanes include vinyl trimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, vinylisobutyldimethoxysilane, vinylethyldimethoxysilane, vinylmethoxydioxysilane. Butoxysilane, vinyldimethoxybutoxysilane, vinyltributoxysilane, vinylmethoxydihexyloxysilane, vinyldimethoxyhexyloxysilane, vinyltrihexyloxysilane, vinylmethoxydioctyloxysilane, vinyldimethoxyoctyloxysilane, vinyltrioctyloxysilane , Vinylmethoxydilauryloxysilane, vinyldimethoxylauryloxysilane, vinylmethoxydioleoxysilane And vinyl dimethoxy I acetoxyphenyl silane.

  The obtained copolymer is then saponified. In such saponification, an alkali catalyst or an acid catalyst is used in a state where the copolymer obtained above is dissolved in alcohol or hydrous alcohol. Done. Examples of the alcohol include methanol, ethanol, propanol, tert-butanol and the like, and methanol is particularly preferably used. The concentration of the copolymer in the alcohol is appropriately selected depending on the viscosity of the system, but is usually selected from the range of 10 to 60% by weight. Catalysts used for saponification include alkali catalysts such as alkali metal hydroxides and alcoholates such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium methylate, lithium methylate, etc., sulfuric acid, Examples include acid catalysts such as hydrochloric acid, nitric acid, metasulfonic acid, zeolite, and cation exchange resin.

The amount of the saponification catalyst used is appropriately selected depending on the saponification method, the target degree of saponification, and the like. Usually, when an alkali catalyst is used, a vinyl ester monomer and 3,4-diacyloxy-1- 0.001-0.1 equivalent with respect to the total amount of monomers, such as butene, Preferably 0.005-0.05 equivalent is suitable. With regard to such a saponification method, batch saponification, continuous saponification on a belt, and continuous saponification of a tower type are possible depending on the target saponification degree, etc., and the amount of alkali catalyst during saponification can be reduced and the saponification reaction is high. For reasons such as efficiency and ease of progress, tower saponification under constant pressure is preferably used. The pressure during saponification cannot be generally specified depending on the target ethylene content, but is selected from the range of ^{2 to} 7 kg / cm ² , and the temperature at this time is 80 to 150 ° C., preferably from 100 to 130 ° C. Selected.

  Thus, EVOH (A) having the structural unit (1) (structural unit having a 1,2-glycol bond) is obtained. In the present invention, the ethylene content of the obtained EVOH (A) is obtained. The saponification degree is not particularly limited, but the ethylene content is 10 to 60 mol% (more preferably 20 to 50 mol%, particularly 25 to 48 mol%), and the saponification degree is 90 mol% or more (further 95). If the ethylene content is less than 10 mol%, the resulting molded article tends to deteriorate the gas barrier property and appearance at high humidity. The gas barrier property of the product tends to decrease, and if the degree of saponification is less than 90 mol%, the gas barrier property and moisture resistance of the molded product tend to decrease, which is not preferable.

Further, the amount of the structural unit having a 1,2-glycol bond introduced into EVOH (A) is not particularly limited, but is 0.1 to 50 mol% (more preferably 0.5 to 40 mol%, particularly 1 to 30 mol%) is preferable, and if the amount introduced is less than 0.1 mol%, the effect of the present invention is not sufficiently exhibited. On the other hand, if it exceeds 50 mol%, the gas barrier property tends to be lowered. Further, in adjusting the amount of structural units having 1,2-glycol bonds, it is also possible to adjust by blending at least two types of EVOH having different introduction amounts of structural units having 1,2-glycol bonds. . Further, at least one of them may not have a structural unit having a 1,2-glycol bond.
With regard to EVOH in which the 1,2-glycol bond amount is adjusted in this way, the 1,2-glycol bond amount can be calculated by weight average, and the ethylene content can also be calculated by weight average. However, precisely, the ethylene content and the 1,2-glycol bond amount can be calculated from the measurement result of ¹ H-NMR described later.

  EVOH (A) having the structural unit (1) obtained by such a method can be used as it is, but furthermore, within the range not impairing the object of the present invention, acids such as acetic acid and phosphoric acid, and alkali metals thereof, Addition of a metal salt such as an alkaline earth metal or transition metal, or boric acid or a metal salt thereof as a boron compound is preferable in terms of improving the thermal stability of the resin.

  The amount of acetic acid added is 0.001 to 1 part by weight (more preferably 0.005 to 0.2 part by weight, particularly 0.010 to 0.1 part per 100 parts by weight of EVOH (A) in the resin composition. If the amount added is less than 0.001 part by weight, the inclusion effect may not be sufficiently obtained. Conversely, if the amount added exceeds 1 part by weight, the appearance of the resulting molded product deteriorates. It tends to be unfavorable.

In addition, borate metal salts include calcium borate, cobalt borate, zinc borate (zinc tetraborate, zinc metaborate, etc.), aluminum borate / potassium borate, ammonium borate (ammonium metaborate, ammonium tetraborate, Ammonium pentaborate, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate, cadmium tetraborate, etc.), potassium borate (potassium metaborate, potassium tetraborate, potassium pentaborate, potassium hexaborate, Potassium octaborate), silver borate (silver metaborate, silver tetraborate, etc.), copper borate (cupric borate, copper metaborate, copper tetraborate, etc.), sodium borate (sodium metaborate) , Sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.), Lead oxalate (lead metaborate, lead hexaborate, etc.), nickel borate (nickel orthoborate, nickel diborate, nickel tetraborate, nickel octaborate, etc.), barium borate (barium orthoborate, metaborate) Barium, barium diborate, barium tetraborate, etc.), bismuth borate, magnesium borate (magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate, etc.), boron In addition to manganese oxide (manganese borate, manganese metaborate, manganese tetraborate, etc.), lithium borate (lithium metaborate, lithium tetraborate, lithium pentaborate, etc.), borax, carnite, inyoite , Borate minerals such as olivine, kyanite, zyberite, etc. Sand, boric acid, sodium borate (sodium metaborate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate acid, eight sodium borate, etc.).
Moreover, as an addition amount of a boron compound, 0.001-1 weight part (further 0.002-0.2 weight part, especially 0.005-0 in conversion of boron with respect to 100 weight part of all EVOH in a composition). .1 part by weight), and if the amount added is less than 0.001 part by weight, the effect of the content may not be sufficiently obtained. It is not preferable because it tends to deteriorate.

  Such metal salts include sodium, potassium, calcium, magnesium, and other organic acids such as acetic acid, propionic acid, butyric acid, lauric acid, stearic acid, oleic acid, and behenic acid, sulfuric acid, sulfurous acid, carbonic acid, and phosphoric acid. And metal salts of inorganic acids such as acetate, phosphate and hydrogen phosphate are preferred. The amount of the metal salt added is 0.0005 to 0.1 parts by weight (more preferably 0.001 to 0.05 parts by weight) in terms of metal with respect to 100 parts by weight of EVOH (A) in the resin composition. In particular, 0.002 to 0.03 parts by weight) is preferable, and if the amount added is less than 0.0005 parts by weight, the content may not be sufficiently obtained. If it exceeds 1, the appearance of the resulting molded product tends to deteriorate, which is not preferable. In addition, when adding 2 or more types of alkali metal and / or alkaline-earth metal salt to EVOH, it is preferable that the total is in the range of said addition amount.

  The method for adding acids or metal salts thereof to EVOH (A) is not particularly limited. A) A porous precipitate of EVOH (A) having a water content of 20 to 80% by weight is converted into an aqueous solution of acids or metal salts thereof. A method in which the acid or its metal salt is added and then dried, and a) a uniform solution (water / alcohol solution, etc.) of EVOH (A) is mixed with the acid or its metal salt, and then in the coagulation liquid Extruded into strands, then cut the resulting strands into pellets and further dried, c) EVOH (A) and acids and their metal salts are mixed together and then melted in an extruder K) a method of kneading, d) a method in which the resin composition and acids or metal salts thereof are mixed together, and then melt kneading with an extruder or the like, and e) an alkali used in the saponification step during the production of EVOH (A). (Sodium hydroxide, (E.g., neutralizing potassium oxide, etc.) with acids such as acetic acid, and adjusting the amount of remaining acid such as acetic acid and by-product sodium metal salt such as sodium acetate and potassium acetate by washing with water Can do. In order to obtain the effects of the present invention more remarkably, the methods (a), (i) and (v), which are excellent in dispersibility of acids and metal salts thereof, are preferred.

The EVOH composition (A) obtained by the method of a), b) or o) is dried after salts and metal salts are added.
As such a drying method, various drying methods can be employed. For example, fluidized drying in which substantially pellet-like EVOH is stirred and dispersed mechanically or with hot air, or substantially pellet-like EVOH is not subjected to dynamic actions such as stirring and dispersion. Examples of dryers for fluidized drying include cylindrical / groove-type stirred dryers, circular tube dryers, rotary dryers, fluidized bed dryers, vibrating fluidized bed dryers, and conical rotations. In addition, as a dryer for performing stationary drying, a batch type box dryer is used as a stationary material type, a band dryer, a tunnel dryer, and a vertical dryer are used as a material transfer type. Although a vessel etc. can be mentioned, it is not limited to these. It is also possible to combine fluidized drying and stationary drying.

  Air or an inert gas (nitrogen gas, helium gas, argon gas, etc.) is used as the heating gas used in the drying process, and the temperature of the heating gas is 40 to 150 ° C., which is the productivity and the heat of EVOH. It is preferable in terms of preventing deterioration. The time for the drying treatment is usually from about 15 minutes to 72 hours, although it depends on the water content of EVOH and the amount of treatment, from the viewpoint of productivity and prevention of thermal degradation of EVOH.

  The EVOH composition (A) is dried under the above conditions. The water content after the drying treatment is 0.001 to 5% by weight (more preferably 0.01 to 2% by weight, especially 0.1%). It is preferable that the water content is less than 0.001% by weight. If the water content is less than 0.001% by weight, long-run moldability tends to decrease. Is not preferable.

  Such EVOH composition (A) has some monomer residues (3,4-diol-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy- within the range not impairing the object of the present invention. 4-ol-1-butene, 4-acyloxy-3-ol-1-butene, 4,5-diol-1-pentene, 4,5-diacyloxy-1-pentene, 4,5-diol-3-methyl- 1-pentene, 4,5-diol-3-methyl-1-pentene, 5,6-diol-1-hexene, 5,6-diacyloxy-1-hexene, 4,5-diacyloxy-2-methyl-1- Butene etc.) and saponified monomers (3,4-diol-1-butene, 4,5-diol-1-pentene, 4,5-diol-3-methyl-1-pentene, 4,5-diol-3 -Methyl-1 Pentene, it may include 5,6-diol-1-hexene, etc.).

In addition, the EVOH used in the present invention is preferably a blend of EVOH containing the structural unit (1) and another EVOH different from this from the viewpoint of improving the gas barrier property and pressure resistance. Examples of EVOH include those having different structural units, those having different ethylene contents, those having different degrees of saponification, and those having different molecular weights.
Examples of the EVOH having a structural unit different from the EVOH having the structural unit (1) include, for example, an EVOH composed only of an ethylene structural unit and a vinyl alcohol structural unit, and a modified EVOH having a functional group such as a 2-hydroxyethoxy group in the side chain of the EVOH. Can be mentioned.
Moreover, when using what has different ethylene content, the structural unit may be the same or different, but the ethylene content difference is 1 mol% or more (further 2 mol% or more, particularly 2 to 2 mol%). 20 mol%). If the ethylene content difference is too large, the transparency may be deteriorated, which is not preferable.

  The melt flow rate (MFR) (210 ° C., load 2160 g) of the EVOH composition (A) thus obtained is not particularly limited, but is 0.1 to 100 g / 10 minutes (further 0.5 to 50 g / 10). When the melt flow rate is smaller than this range, the extruder tends to be in a high torque state during molding, making extrusion difficult. If it is larger than this range, the appearance and gas barrier properties during heat-stretching molding tend to decrease, such being undesirable.

Next, the polyamide resin (B) used in the present invention will be described.
Specific examples of the polyamide resin (B) used in the present invention include polycapramide (nylon 6), poly-ω-aminoheptanoic acid (nylon 7), poly-ω-aminononanoic acid (nylon 9), polyundecanamide ( Nylon 11), polylauryl lactam (nylon 12), polyethylenediamine adipamide (nylon 26), polytetramethylene adipamide (nylon 46), polyhexamethylene adipamide (nylon 66), polyhexamethylene sebacamide (Nylon 610), polyhexamethylene dodecamide (nylon 612), polyoctamethylene adipamide (nylon 86), polydecamethylene adipamide (nylon 108), caprolactam / lauryl lactam copolymer (nylon 6/12) , Caprolactam / ω-aminononane Copolymer (nylon 6/9), caprolactam / hexamethylene diammonium 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 (nylon 66/610), ethylene ammonium adipate / hexamethylene diammonium adipate / hexa Methylenediammonium sebacate copolymer (nylon 6/66/610), polyhexamethylene isophthalamide, polyhexamethylene terephthalamide, hexamethylene iso Examples thereof include those obtained by modifying a thalamide / terephthalamide copolymer or a polyamide resin thereof with an aromatic amine such as methylenebenzylamine or metaxylenediamine, or metaxylylene diamine adipate. A polyamide-based resin whose terminal is adjusted with a group is preferably used.

  As the polyamide-based resin (B) whose terminal is adjusted, caproamide is the main structural unit, and the terminal carboxyl group content [X] and the terminal amino group content [Y] using a terminal adjusting agent are {( 100 × [Y]) / ([X] + [Y])} ≧ 5 (where units of [X] and [Y] are μeq / g · polymer) (B) ) Is used.

  As a terminal regulator in the above, a C2-C23 carboxylic acid and a C2-C20 diamine are used. Here, the monocarboxylic acid having 2 to 23 carbon atoms includes aliphatic monocarboxylic acids (acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, capric acid, pelargonic acid, undecanoic acid, lauric acid. , Tridecanoic acid, myristic acid, myroleic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid, behenic acid, etc.), alicyclic monocarboxylic acids (cyclohexanecarboxylic acid, methylcyclohexanecarboxylic acid, etc.), aromatic Group monocarboxylic acids (benzoic acid, toluic acid, ethylbenzoic acid, phenylacetic acid, etc.).

  Examples of the diamine having 2 to 20 carbon atoms include aliphatic diamines [ethylene diamine, trimethylene diamine, tetramethylene diamine, pentamethylene diamine, hexamethylene diamine, octamethylene diamine, decamethylene diamine, dodecamethylene diamine, hexadecamethylene diamine, 2 , 2,4- (or 2,4,4-) trimethylhexamethylenediamine], etc.], alicyclic diamines [cyclohexanediamine, bis- (4,4'-aminocyclohexyl) methane, etc.], aromatic diamines (xyli Range amine etc.).

  In addition to the above monocarboxylic acids, aliphatic dicarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, hexadecanedione Acid, hexadecenedioic acid, octadecanedioic acid, octadecenedioic acid, eicosadioic acid, eicosenedioic acid, docosandioic acid, 2,2,4-trimethyladipic acid, etc.), alicyclic dicarboxylic acid (1,4-cyclohexanedicarboxylic acid) Acid) and aromatic dicarboxylic acids (terephthalic acid, isophthalic acid, phthalic acid, xylylene dicarboxylic acid, etc.) can be used or used in combination.

  The degree of polymerization of the polyamide-based resin (B) is not particularly limited, but is preferably 1.7 to 5.0, particularly preferably 2.0 to 5.0, in terms of relative viscosity measured according to JIS K6810. .

  As a polymerization method for the polyamide-based resin (B), melt polymerization, interfacial polymerization, solution polymerization, bulk polymerization, solid phase polymerization, or a combination of these can be employed. Moreover, as a polyamide raw material, (epsilon) -caprolactam is especially preferable at the point from which more favorable boil resistance and retort resistance are obtained.

  The resin composition of the present invention comprises the EVOH (A) and the polyamide resin (B), and the content ratio of the EVOH (A) and the polyamide resin (B) in the resin composition is particularly high. Although it is not limited, it is preferable to contain 95 / 5-60 / 40 (95 / 5-65 / 35, especially 90 / 10-70 / 30) (weight ratio), and when this content rate exceeds 95/5 Appearance and gas barrier properties after retort treatment tend to be reduced. Conversely, if it is less than 60/40, gas barrier properties tend to decrease, which is not preferable.

  The blending method of EVOH (A) and polyamide-based resin (B) for obtaining the resin composition of the present invention is not particularly limited, but a melt-mixing method is preferable because uniform mixing is possible.

  As the method of melt mixing, for example, a known kneading apparatus such as a kneader rudder, an extruder, a mixing roll, a Banbury mixer, a plast mill, etc. can be used. Usually, a single or twin screw extruder is used. It is industrially preferable to use it, and it is also preferable to provide a vent suction device, a gear pump device, a screen device, etc. as needed. In particular, in order to remove moisture and by-products (such as pyrolytic low molecular weight substances), one or more vent holes are provided in the extruder and suction is performed under reduced pressure, or oxygen is prevented from entering the extruder. Therefore, by continuously supplying an inert gas such as nitrogen into the hopper, a resin composition having excellent quality with reduced thermal coloring and thermal deterioration can be obtained.

  Also, the method of supplying each resin to the extruder is not particularly limited. (A) A method of dry blending EVOH (A) and the polyamide resin (B) and supplying them to the extruder in a batch, b) EVOH ( B) A method in which either the polyamide resin (B) is supplied to an extruder and melted to supply the other solid (solid side feed method), c) EVOH (A) or a polyamide resin ( Examples include a method (melt side feed method) in which any one of B) is supplied to an extruder and melted, and the other melted state is supplied (melt side feed method). Industrially practical in terms of simplicity and cost of the blend.

  The resin composition of the present invention thus obtained can be used for melt molding or the like as it is, but in the present invention, a saturated aliphatic amide (for example, as long as the object of the present invention is not hindered by the resin composition) Stearic acid amide), unsaturated fatty acid amide (such as oleic acid amide), bis fatty acid amide (such as ethylene bis stearic acid amide), fatty acid metal salt (such as calcium stearate, magnesium stearate), low molecular weight polyolefin (such as Lubricants such as low molecular weight polyethylene having a molecular weight of about 500 to 10,000, or low molecular weight polypropylene), inorganic salts (for example, hydrotalcite), plasticizers (for example, aliphatic polyhydric alcohols such as ethylene glycol, glycerin, hexanediol) Etc.), oxygen absorbers (for example, inorganic oxygen absorbers and In addition, reduced iron powders, further added with water-absorbing substances and electrolytes, aluminum powder, potassium sulfite, photocatalytic titanium oxide, and the like are ascorbic acid, fatty acid esters and metals thereof as organic compound-based oxygen absorbers. Salt, hydroquinone, gallic acid, polyhydric phenols such as hydroxyl group-containing phenol aldehyde resin, bis-salicylaldehyde-imine cobalt, tetraethylenepentamine cobalt, cobalt-Schiff base complex, porphyrins, macrocyclic polyamine complex, polyethyleneimine -Coordinated conjugates of nitrogen-containing compounds such as cobalt complexes with transition metals, terpene compounds, reactants of amino acids and reducing substances containing hydroxyl groups, triphenylmethyl compounds, etc. Coordination conjugate of containing resin and transition metal (eg MXD NA) Iron and cobalt), tertiary hydrogen-containing resin and transition metal blend (eg, polypropylene and cobalt), carbon-carbon unsaturated bond containing resin and transition metal (eg, polybutadiene and cobalt) ), Photo-oxidatively disintegrating resins (eg, polyketone), anthraquinone polymers (eg, polyvinyl anthraquinone), etc., and further to these compounds, photoinitiators (benzophenone, etc.) and peroxide supplements (commercially available oxidation) ), Heat stabilizers, light stabilizers, antioxidants, UV absorbers, colorants, antistatic agents, surfactants, antibacterial agents, anti-reactive agents, etc.) You may mix | blend a blocking agent, a slip agent, a filler (for example, inorganic filler etc.), other resin (for example, polyolefin etc.), etc.

Thus, although the resin composition of the present invention is obtained, such a resin composition is useful for a molded product, particularly useful for melt molding, and such melt molding will be described below.
Examples of the molded product include single-layered or multilayered (laminated) films, sheets, containers, tubes, and the like, and examples of the laminating method when laminating with other base materials include the film of the resin composition of the present invention. , A method of melt extrusion laminating another substrate on a sheet, a method of melt extrusion laminating the resin to another substrate, a method of coextruding the resin and another substrate, and the resin (layer) And other base materials (layers) may be dry-laminated using known adhesives such as organic titanium compounds, isocyanate compounds, polyester compounds, polyurethane compounds, etc., but multilayer structures (laminates) A co-extrusion method is preferred because it can be easily produced.

  As the co-extrusion method, specifically, a known method such as a multi-many hold die method, a feed block method, a multi-slot die method, or a die external bonding method can be employed. As the shape of the die, there are a T die and a round die, and the T die is preferable in that the stretchability can be further improved by quenching immediately after film formation. The film forming speed is preferably 10 to 200 m / min from the viewpoint of productivity and stability of film properties. The melt molding temperature during melt extrusion is preferably 150 to 300 ° C.

  As such other base materials, thermoplastic resins are useful. Specifically, linear low density polyethylene, low density polyethylene, ultra-low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer Polymer, ionomer, ethylene-propylene (block and random) copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polypropylene, propylene-α-olefin (α-olefin having 4 to 20 carbon atoms) ) Polyolefin resins and polyesters in a broad sense, such as copolymers, polybutenes, polypentenes or other olefins or copolymers, or those olefins alone or copolymers grafted with unsaturated carboxylic acids or esters thereof Resin, polyamide resin (including copolyamide) ), Polyvinyl chloride, polyvinylidene chloride, acrylic resin, polystyrene, vinyl ester resin, polyester elastomer, polyurethane elastomer, chlorinated polyethylene, chlorinated polypropylene, aromatic or aliphatic polyketone, and reduction of these Polyalcohols, and other EVOH, etc., but from the point of practicality such as physical properties (particularly strength) of the laminate, polypropylene, ethylene-propylene (block or random) copolymer, polyamide, polyethylene, An ethylene-vinyl acetate copolymer, polystyrene, polyethylene terephthalate (PET), and polyethylene naphthalate (PEN) are preferably used.

  Furthermore, when a substrate such as a film, a sheet, or a stretched film of the resin composition of the present invention is extrusion coated with another substrate, or a film, a sheet, or the like of another substrate is laminated using an adhesive, this is required. As the base material, any base material (paper, metal foil, uniaxial or biaxially stretched plastic film or sheet and its inorganic deposit, woven fabric, non-woven fabric, metallic cotton, wood, etc.) can be used in addition to the thermoplastic resin. It can be used.

  The layer structure of the laminate is a (a1, a2,...) For the resin composition layer of the present invention, and b (b1, b2,...) For another substrate such as a thermoplastic resin layer. When it is a film, sheet or bottle shape, not only a / b two-layer structure but also b / a / b, a / b / a, a1 / a2 / b, a / b1 / b2, b2 / b1 Any combination such as / a / b1 / b2, b2 / b1 / a / b1 / a / b1 / b2, and the like, and further, a regrind layer composed of at least a mixture of the EVOH composition and a thermoplastic resin is formed into R And 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., and in the filament form, a and b are bimetal type, core (a) -sheath (b) type, core (b) -sheath (a) type, or eccentric core sheath Any combination like are possible. In the above layer structure, an adhesive resin layer can be provided between the respective layers as required, and various types of such adhesive resins can be used. However, the carboxyl group obtained by chemically bonding an unsaturated carboxylic acid or its anhydride to an olefin polymer (the above-mentioned polyolefin resin in the broad sense) by an addition reaction or a graft reaction is not possible. Examples of the modified olefin-based polymer include maleic anhydride graft-modified polyethylene, maleic anhydride graft-modified polypropylene, maleic anhydride graft-modified ethylene-propylene (block and random) copolymer, anhydrous Maleic acid graft modified ethylene-ethyl acrylate copolymer, maleic anhydride Shift modified ethylene - 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 anhydride thereof contained in the thermoplastic resin is preferably 0.001 to 3% by weight, more preferably 0.01 to 1% by weight, particularly preferably 0.03. ~ 0.5 wt%. If the amount of modification in the modified product is small, the adhesiveness may be insufficient. On the other hand, if the amount is too large, a crosslinking reaction may occur and the moldability may be deteriorated. Further, these adhesive resins can be blended with the EVOH composition of the present invention, other EVOH, polyisobutylene, rubber / elastomer components such as ethylene-propylene rubber, and the resin of the b layer. In particular, blending a polyolefin-based resin different from the base polyolefin-based resin of the adhesive resin is useful because the adhesiveness may be improved.

  In addition, it is preferable that the resin composition layer is an intermediate layer and a polyolefin resin is present on the inner layer side from the viewpoint of good appearance after retort, and a polyamide-based resin layer is disposed adjacent to at least one surface of the resin composition layer. It is preferable that the gas barrier performance immediately after the retort is good.

  The thickness of each layer of the laminate cannot be generally stated depending on the layer configuration, the type of b, the use and container form, the required physical properties, etc., but usually the a layer is 2 to 500 μm (further 3 to 200 μm), b The layer is selected from the range of about 10 to 5000 μm (more preferably 30 to 1000 μm), and the adhesive resin layer is about 1 to 400 μm (more preferably 2 to 150 μm).

  The base resin layer may contain an antioxidant, an antistatic agent, a lubricant, a core material, an antiblocking agent, an ultraviolet absorber, a wax and the like as conventionally known.

The laminate is used in various shapes as it is, but it is also preferable to perform a heat stretching treatment in order to further improve the physical properties of the laminate or to form a desired container shape. Here, the heat-stretching treatment refers to a film, sheet, or parison-like laminate that has been heated uniformly and uniformly by a chuck, plug, vacuum force, pneumatic force, blow, etc. This stretching may be either uniaxial stretching or biaxial stretching, and physical properties are better when stretching as high as possible. Thus, a stretched molded article having excellent gas barrier properties that does not cause stretching unevenness, uneven thickness, delamination and the like can be obtained.
When stretching the laminate, it may be either uniaxial stretching or biaxial stretching, and it is better in terms of physical properties to perform stretching at as high a magnification as possible. In the case of uniaxial stretching, it is preferably 5 times or more, particularly 10 times or more, and in the case of biaxial stretching, the area magnification is preferably 5 times or more, particularly preferably 10 times or more, but in the present invention, the area magnification is 20 times. It is also possible to make it at least twice, particularly 24 to 50 times. Even at this time, a stretched film or stretched sheet that does not cause pinholes, cracks, stretch unevenness, etc. during stretching can be obtained.

  As the stretching method, in addition to a roll stretching method, a tenter stretching method, a tubular stretching method, a stretching blow method, and the like, a deep drawing method, a vacuum forming method, or the like having a high stretching ratio can be employed. In the case of biaxial stretching, both a simultaneous biaxial stretching method and a sequential biaxial stretching method can be employed. The stretching temperature is selected from the range of about 80 to 170 ° C, preferably about 100 to 160 ° C.

  Thus, after stretching is completed, heat setting is then performed. The heat setting can be carried out by a known means, and the heat treatment is performed at 80 to 170 ° C., preferably 100 to 160 ° C. for about 2 to 600 seconds while keeping the stretched film in a tension state. Moreover, the stretched film obtained is subjected to cooling treatment, rolling treatment, printing treatment, dry laminating treatment, solution or melt coating treatment, bag making processing, depth sticking processing, box processing, tube processing, split processing, etc. Can do.

  The laminate thus obtained may have 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 a modified cross-section extrudate. In addition, the obtained laminate can be subjected to heat treatment, cooling treatment, rolling treatment, printing treatment, dry lamination treatment, solution or melt coating treatment, bag making processing, deep drawing processing, box processing, tube processing, split processing, etc. It can be carried out.

Containers made of cups, trays, tubes, bottles, pouches, bags, etc. obtained as described above, bags and lids made of stretched film are seasonings such as mayonnaise and dressing, fermentation of miso, etc. It is useful as various containers such as foods and oils and fats such as salad oil, beverages, cosmetics, pharmaceuticals, detergents, cosmetics, industrial chemicals, agricultural chemicals, and fuels.
In particular, the resin composition of the present invention is useful for retort applications.

  Hereinafter, the method of the present invention will be specifically described with reference to examples. In the following, “%” means a weight basis unless otherwise specified.

Polymerization example 1
An EVOH composition (A1) was obtained by the following method.
A 1 m ³ polymerization can with a cooling coil is charged with 500 kg of vinyl acetate, 100 kg of methanol, 500 ppm of acetyl peroxide (vs. vinyl acetate), 20 ppm of citric acid, and 14 kg of 3,4-diacetoxy-1-butene. After replacing with gas once, and then replacing with ethylene, the mixture was injected until the ethylene pressure became 35 kg / cm ² , stirred, and then heated to 67 ° C., and 3,4-diacetoxy-1-butene was added. Polymerization was carried out while adding a total amount of 4.5 kg at 15 g / min, and polymerization was conducted for 6 hours until the polymerization rate reached 50%. Thereafter, the polymerization reaction was stopped to obtain an ethylene-vinyl acetate copolymer having an ethylene content of 29 mol%.

A methanol solution of the ethylene-vinyl acetate copolymer was supplied at a rate of 10 kg / hour from the top of a plate tower (saponification tower), and at the same time 0.012% of the remaining acetic acid groups in the copolymer. A methanol solution containing an equivalent amount of sodium hydroxide was fed from the top of the tower. On the other hand, methanol was supplied at 15 kg / hour from the bottom of the tower. The tower temperature was 100 to 110 ° C., and the tower pressure was 3 kg / cm ² G. From 30 minutes after the start of charging, a methanol solution of EVOH having a structural unit having a 1,2-glycol bond (EVOH 30%, methanol 70%) was taken out. The saponification degree of the vinyl acetate component of EVOH was 99.5 mol%.

  Next, the obtained methanol solution of EVOH was supplied from the top of the methanol / water solution adjusting tower at 10 kg / hour, and methanol vapor at 120 ° C. was charged from the bottom of the tower at a rate of 4 kg / hour and steam at 2.5 kg / hour. At the same time, methanol was distilled from the top of the column at 8 kg / hour, and at the same time, 6 equivalents of methyl acetate with respect to the amount of sodium hydroxide used in the saponification was charged from the middle of the column at 95-110 ° C. A water / alcohol solution of EVOH (resin concentration 35%) was obtained.

The obtained EVOH water / alcohol solution was extruded in a strand form from a nozzle with a pore diameter of 4 mm into a coagulation liquid tank maintained at 5 ° C. consisting of 5% methanol and 95% water. Cutting with a cutter gave EVOH porous pellets having a diameter of 3.8 mm and a length of 4 mm and a moisture content of 45%.
After washing with 100 parts of water with respect to 100 parts of the porous pellets, the mixture was put into a mixed solution containing 0.032% boric acid and 0.007% calcium dihydrogen phosphate, and at 30 ° C. for 5 hours. Stir. Further, the porous pellets were dried for 12 hours by passing nitrogen gas having a temperature of 70 ° C. and a moisture content of 0.6% in a batch-type ventilated box dryer, and the moisture content was adjusted to 30%. Using a batch tower type fluidized bed dryer, drying was performed with nitrogen gas having a temperature of 120 ° C. and a water content of 0.5% for 12 hours to obtain pellets of the target EVOH composition (A1). Such pellets contain 0.015 parts by weight (in terms of boron) and 0.005 parts by weight (in terms of phosphate group) of boric acid and calcium dihydrogen phosphate with respect to 100 parts by weight of EVOH, respectively, and MFR (210 ° C., 2160 g). ) Was 4.0 g / 10 min.

The amount of 1,2-glycol bond introduced was calculated by measuring the ethylene-vinyl acetate copolymer before saponification with ¹ H-NMR (internal standard substance: tetramethylsilane, solvent: d6-DMSO). However, it was 2.5 mol%. In addition, “AVANCE DPX400” manufactured by Nippon Bruker Co., Ltd. was used for NMR measurement.

[ ¹ H-NMR] (see FIG. 1)
1.0 to 1.8 ppm: methylene proton (integrated value a in FIG. 1)
1.87 to 2.06 ppm: methyl proton 3.95 to 4.3 ppm: proton on the methylene side of structure (I) + unreacted 3,4-diacetoxy-1-butene proton (integral value b in FIG. 1) )
4.6 to 5.1 ppm: methine proton + proton on the methine side of structure (I) (integral value c in FIG. 1)
5.2 to 5.9 ppm: unreacted 3,4-diacetoxy-1-butene proton (integral value d in FIG. 1)

[Calculation method]
Since there are four protons in 5.2 to 5.9 ppm, the integral value of one proton is d / 4, and the integral value b is an integral value including the protons of the diol and the monomer. The integral value (A) of the proton is A = (b−d / 2) / 2, and the integral value c is an integral value including the protons on the vinyl acetate side and the diol side. Since the integral value (B) is B = 1− (b−d / 2) / 2 and the integral value a is an integral value including ethylene and methylene, the integral value (C) of one proton of ethylene is , C = (a−2 × A−2 × B) / 4 = (a−2) / 4, and the introduction amount of the structural unit (1) is 100 × {A / (A + B + C)} = 100 × Calculated from (2 × b−d) / (a + 2).

Moreover, the result of having similarly performed ¹ H-NMR measurement also about EVOH after saponification is shown in FIG. Since the peak corresponding to 1.87 to 2.06 ppm of methyl proton is greatly reduced, the copolymerized 3,4-diacetoxy-1-butene is also saponified into a 1,2-glycol structure. It is clear that

Polymerization example 2
An EVOH composition (A2) was obtained by the following method.
In polymerization example 1, polymerization was carried out while adding 3 kg of 3,4-diacetoxy-1-butene at a rate of 26 g / min, and the introduction amount of structural units having a 1,2-glycol bond at an ethylene content of 29 mol% was 29 mol%. An EVOH composition containing 3.0 mol%, boric acid 0.015 parts by weight (in terms of boron), calcium dihydrogen phosphate 0.005 parts by weight (in terms of phosphate radicals), and MFR 3.7 g / 10 min ( A2) was obtained.

Polymerization example 3
An EVOH composition (A3) was obtained by the following method.
70 of 3,4-diacetoxy-1-butene, 3-acetoxy-4-ol-1-butene and 1,4-diacetoxy-1-butene instead of 3,4-diacetoxy-1-butene in polymerization example 1: The same procedure was performed except that a 20:10 mixture was used, and the amount of structural units having 1,2-glycol bonds introduced was 2.0 mol%, the ethylene content was 29 mol%, and the boric acid content was 0.015 parts by weight. An EVOH composition (A3) containing (in terms of boron), containing 0.005 parts by weight of phosphoric acid (in terms of phosphate radical) and having an MFR of 3.7 g / 10 min was obtained.

  Separately, ethylene content 29 mol% not containing structural unit (1), saponification degree 99.5 mol%, MFR = 3.5 g / min (210 ° C., 2160 g), boric acid content (boron conversion) 0 An EVOH composition (A4) containing 0.15 part by weight and 0.005 part by weight of phosphoric acid (in terms of phosphate radical) was prepared.

Example 1
The EVOH composition (A1) obtained above and the end-capped nylon (B) [terminal carboxyl group content 20 μeq / g, terminal amino group content 26 μeq / g] are 30 mmφ so that the blending weight ratio is 85:15. It used for the twin-screw extruder, was melt-mixed at 240 degreeC, and obtained the pellet of the target resin composition.

  Pellet (resin composition) (a) obtained above, nylon-6 ["NOVAMID 1022-1" manufactured by Mitsubishi Engineering Plastics] (b), polypropylene ["FL6CK" manufactured by Nippon Polychem, Inc.] (c) and Adhesive resin [“ADMER QF500” manufactured by Mitsui Chemicals, maleic anhydride-modified polypropylene] (d) is supplied to a feed block type coextrusion multilayer film molding machine (manufactured by Gunze Sangyo Co., Ltd.), and (b) / (a ) / (D) / (c) = 20/20/10/80 (μm; thickness) was formed into a laminate (multilayer film).

About the obtained laminated body, the external appearance property, gas barrier property, and the anti-pinhole after a retort process were evaluated as follows.
(Appearance)
The obtained multilayer film is sealed on all sides so that the layer (c) is on the inside, and a 15 cm × 15 cm pouch containing 150 ml of distilled water is prepared. The pouch is retorted at 130 ° C. for 30 minutes and immediately after taking out. The appearance of the pouch was visually observed and evaluated as follows.
○: Overall high transparency and no unevenness Δ ... Locally whitening is recognized × ... Overall uneven whitening is observed

(Gas barrier properties)
The multilayer film cut out from the pouch after the above retort was allowed to stand in an environment of 23 ° C. and Dry for 24 hours, and then the oxygen permeability measuring device “OX-TRAN 2/20 manufactured by MOCON under the conditions of 23 ° C. and 80% RH. Was used to measure oxygen permeability (cc / m ² · day · atm).

(Pinhole resistance)
The obtained multilayer film was cut into A4 size (21 × 29.7 cm), fixed with the four ends open, and retorted at 130 ° C. for 30 minutes, and then gelboflex tester (manufactured by Rigaku Corporation) ), In a 50 ° RH atmosphere at 23 ° C., after repetitive reciprocating motion of 440 ° twist (3.5 inches) + straight forward (2.5 inches) 100 times, 23 ° C., 80% The oxygen permeability (cc / m ² · day · atm) was measured using an oxygen permeability measuring device “OX-TRAN 2/20” manufactured by MOCON under the condition of RH. When pinholes are generated in the EVOH layer, the barrier property is lowered and the oxygen permeability is increased.

Example 2
In Example 1, a resin composition was prepared in the same manner except that the EVOH composition (A2) was used instead of the EVOH composition (A1), and evaluation was performed in the same manner.

Example 3
In Example 1, a resin composition was prepared in the same manner except that the EVOH composition (A3) was used instead of the EVOH composition (A1), and the same evaluation was performed.

Comparative Example 1
In Example 1, a multilayer structure was prepared using only the EVOH composition (A4) instead of the resin composition, and the same evaluation was performed.

Comparative Example 2
In Example 1, a resin composition was prepared in the same manner except that the EVOH composition (A4) was used instead of the EVOH composition (A1), and the same evaluation was performed.

The evaluation results of Examples and Comparative Examples are summarized in Table 1.

*：測定上限を超えたため測定不可 [Table 1]

*: Cannot be measured because the measurement upper limit has been exceeded

  The resin composition of the present invention and the multilayer structure using the resin composition are excellent in retort resistance at high temperatures, gas barrier properties, pinhole resistance, food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, etc. It is useful as various packaging materials, and is particularly useful for retort applications.

2 is a ¹ H-NMR chart before saponification of EVOH obtained in Polymerization Example 1. FIG. 2 is a ¹ H-NMR chart of EVOH obtained in Polymerization Example 1.

Claims (15)

A resin composition comprising an ethylene-vinyl alcohol copolymer (A) containing the following structural unit (1) and a polyamide resin (B).

(Here, X is a bond chain and is an arbitrary bond chain excluding an ether bond, R1 to R4 are each independently an arbitrary substituent, and n represents 0 or 1.)   R1 to R4 of the structural unit (1) are each independently a hydrogen atom, a hydrocarbon group having 1 to 8 carbon atoms, a cyclic hydrocarbon group having 3 to 8 carbon atoms, or an aromatic hydrocarbon group. The resin composition according to claim 1.   The resin composition according to claim 1 or 2, wherein R1 to R4 of the structural unit (1) are all hydrogen atoms.   The resin composition according to any one of claims 1 to 3, wherein X in the structural unit (1) is alkylene having 6 or less carbon atoms.   N of said structural unit (1) is 0, The resin composition in any one of Claims 1-3 characterized by the above-mentioned.   6. The resin composition according to claim 1, wherein the structural unit (1) is introduced into the molecular chain of the ethylene-vinyl alcohol copolymer (A) by copolymerization.   The resin composition according to any one of claims 1 to 6, comprising 0.1 to 30 mol% of the structural unit (1) in the molecular chain of the ethylene-vinyl alcohol copolymer (A).   The ethylene-vinyl alcohol copolymer (A) is obtained by saponifying a copolymer of 3,4-diasiloxy-1-butene, a vinyl ester monomer and ethylene. 7. The resin composition according to any one of 7.   The ethylene-vinyl alcohol copolymer (A) is obtained by saponifying a copolymer of 3,4-diacetoxy-1-butene, a vinyl ester monomer and ethylene. 8. The resin composition according to any one of 8.   The ethylene-vinyl alcohol copolymer (A) contains a boron compound in an amount of 0.001 to 1 part by weight in terms of boron with respect to 100 parts by weight of the ethylene-vinyl alcohol copolymer. A resin composition as described above.   The resin composition according to any one of claims 1 to 10, wherein the polyamide-based resin (B) is a terminal-adjusted polyamide-based resin.   The content weight ratio (A / B) of the ethylene-vinyl alcohol copolymer (A) and the polyamide resin (B) is 95/5 to 60/40, according to any one of claims 1 to 11. Resin composition.   A multilayer structure comprising at least one layer containing the resin composition according to claim 1.   A multilayer structure comprising a polyolefin resin layer disposed inside a layer containing the resin composition according to claim 1. The multilayer structure according to claim 13 or 14, wherein a polyamide resin layer is disposed adjacent to at least one side of the layer containing the resin composition according to any one of claims 1 to 12.

Images