JP5089071B2 - Resin composition - Google Patents

Description

  The present invention relates to a resin composition comprising an ethylene-vinyl alcohol copolymer (A) containing a specific structural unit and an oxygen-absorbing substance (B), and more specifically, good gas barrier properties and transparency. The present invention relates to a resin composition having

  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. Used in various packaging materials such as materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, etc., and multilayered with other thermoplastic resins for the purpose of supplementing the mechanical properties and moisture resistance of EVOH It is often used as a body.

In order to further improve the oxygen barrier property, studies have been made to impart oxygen absorption to EVOH. A method of adding a transition metal to EVOH (see, for example, Patent Document 1), a resin comprising a polyolefin and an oxidation catalyst A method of adding the composition to EVOH (for example, see Patent Document 2) and a method of adding a polymer having a specific carbon-carbon double bond and a transition metal salt to EVOH (for example, see Patent Document 3). Proposed.
Japanese Patent Laid-Open No. 04-211444 Japanese Patent Laid-Open No. 05-156095 JP 2001-106866 A

  However, when the inventor examined the above methods in detail, the method described in Patent Document 1 has a low oxygen absorption rate and a small effect of improving gas barrier properties. Transparency is low due to lack of compatibility between EVOH and polymers other than EVOH. Furthermore, when the EVOH layer is thin (about 15 microns) at high temperature and high humidity, the conventional EVOH is used. As in the case of EVOH, a sufficient oxygen barrier property cannot be obtained, and an EVOH resin composition exhibiting a good gas barrier property under such conditions is desired.

（ ここで、Ｘ は炭素数５ 以下のアルキレン鎖で、Ｒ １ 〜 Ｒ ４ は水素原子であり、ｎ は０ または１ を表す。）
すなわち、本発明においては、Ｅ Ｖ Ｏ Ｈ として１ ， ２ − グリコール結合を有する構造単位を含有するＥ Ｖ Ｏ Ｈ を用いることで併用する酸素吸収性物質との良好な親和性が得られ、その結果、フィルム等に成形した場合の良好な透明性とガスバリア性が得られたものと推測される。
また、本発明においては、上記の構造単位（ １ ） が共重合により導入されてＥ Ｖ Ｏ Ｈ の主鎖に有していること、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 inventor contains E V O H (A) containing the following structural unit (1) and an oxygen-absorbing substance (B) , The ethylene content of the ethylene-vinyl alcohol copolymer (A) is 10 to 60 mol%, the saponification degree is 90 mol% or more, and the structural unit amount of the structural unit (1) is 0.1 to 30 mol. %, The melt flow rate (210 ° C., weight 2160 g) is 0.1 to 100 g / 10 min, and the oxygen-absorbing substance (B) is an oxidizable thermoplastic resin (B 1) and an oxidation catalyst (B 2), wherein the oxidizable thermoplastic resin (B 1) is a polymer (B1 2) having a polyalkylene ether unit, and the ethylene-vinyl alcohol copolymer (A) and oxygen in the resin composition Absorbable substance (B) Resin composition content is characterized by a 99.5 / 0.5 to 50/50 (weight ratio) and have completed the present invention found that meets the above object.

(Here, X is an alkylene chain having 5 or less carbon atoms , R 1 to R 4 are hydrogen atoms , and n represents 0 or 1.)
That is, in the present invention, good affinity with the oxygen-absorbing substance used in combination is obtained by using E V O H containing a structural unit having a 1,2-glycol bond as E V O H. As a result, it is presumed that good transparency and gas barrier properties were obtained when formed into a film or the like.
In the present invention, this and, it, etc. preferably contains a boron compound is et embodiment having the above structural unit (1) is introduced by copolymerization in the backbone of E V O H It is.

  The resin composition of the present invention contains EVOH and an oxygen-absorbing substance, and EVOH has a specific structural unit, and therefore has good gas barrier properties and transparency.

The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and is not limited to these contents.
Hereinafter, the present invention will be described in detail.

E V O H (A) used in the present invention is the above-mentioned structural unit (1), that is, E V O H containing a structural unit having a 1,2-glycol bond, and the structural unit (1) R1 ~ R 4 in the Ru Oh in all hydrogen atom.

Regarding the bond chain (X) that connects the molecular chain of EVOH and the 1,2-glycol bond structure, the carbon of the main chain and the carbon of the 1,2-glycol bond structure are preferably bonded directly. However, a bond chain may be used as long as it does not inhibit the effect of the present invention, and as such a bond chain, alkylene is preferable as a bond type in terms of heat melting stability, and further, the number of carbon atoms is further reduced. An alkylene of 5 or less is preferred. In addition, a resin composition 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. better not.

  The method for producing 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 the 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. And those having alkylene as the connecting chain (X) include 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, etc. and vinyl Examples include a method of saponifying a copolymer obtained by copolymerizing a steal monomer and ethylene, and obtained by copolymerizing 3,4-diasiloxy-1-butene, a vinyl ester monomer and ethylene. A method of saponifying the copolymer is preferable from the viewpoint of excellent copolymerization reactivity, and 3,4-diacetoxy-1-butene is preferably used as 3,4-diasiloxy-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。また、１，４―ブタンジオール製造工程中の副生成物として得られる３，４−ジアセトキシ−１−ブテンを利用することも出来る。 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. Further, 3,4-diacetoxy-1-butene obtained as a by-product during the production process of 1,4-butanediol can also be used.

  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-methylpropane sulfonic acid, vinyl ethylene carbonate, 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.

  Furthermore, the amount of the structural unit having a 1,2-glycol bond introduced into EVOH is not particularly limited, but is 0.1 to 30 mol% (more preferably 0.5 to 25 mol%, particularly 1 to 20 mol%). 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 30 mol%, the gas barrier property tends to decrease, which is not preferred. 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. However, the difference in the ethylene content of EVOH at that time is preferably less than 2 mol%. Further, at least one of them may not have a structural unit having a 1,2-glycol bond.

  EVOH (A) having the structural unit (1) obtained by such a method can be used as it is, but further, acetic acid, phosphoric acid and the like are added to the resin composition of the present invention within a range not impairing the object of the present invention. It is preferable to add boric acid or a metal salt thereof as a boron compound in order to improve the thermal stability of the resin.

  The amount of acetic acid added is 0.001 to 1 part by weight (further 0.005 to 0.2 part by weight, particularly 0.010 to 0.1 part by weight) with respect to 100 parts by weight of EVOH 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 tends to deteriorate. Absent.

  In addition, borate metal salts include calcium borate, aluminum / potassium borate, ammonium borate (ammonium metaborate, ammonium tetraborate, ammonium pentaborate, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate) Cadmium tetraborate), potassium borate (potassium metaborate, potassium tetraborate, potassium pentaborate, potassium hexaborate, potassium octaborate, etc.), sodium borate (sodium metaborate, sodium diborate) , Sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc.), lead borate (lead metaborate, lead hexaborate, etc.), barium borate (barium orthoborate, barium metaborate, Barium diborate, barium tetraborate, etc.), bismuth borate, Magnesium oxide (magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, pentamagnesium tetraborate, etc.), lithium borate (lithium metaborate, lithium tetraborate, lithium pentaborate, etc.), etc. In addition, borate minerals such as borax, carnite, inyoite, agateite, suinanite, zyberite, etc. are preferable, borax, boric acid, sodium borate (sodium metaborate, diborate) Sodium, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, 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. Further, the addition amount of the metal salt is 0.0005 to 0.1 parts by weight (more preferably 0.001 to 0.05 parts by weight, particularly 0) with respect to 100 parts by weight of EVOH in the resin composition. 0.0002 to 0.03 parts by weight), and if the amount added is less than 0.0005 parts by weight, the content may not be sufficiently obtained. 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 of adding acids or metal salts thereof to the resin composition is not particularly limited. A) A porous precipitate of EVOH having a water content of 20 to 80% by weight is brought into contact with an aqueous solution of acids or metal salts thereof. , A method of drying after containing an acid or its metal salt, and b) adding an acid or its metal salt to a uniform EVOH solution (water / alcohol solution, etc.) and then extruding it into a coagulation liquid, A method in which the obtained strand is cut into pellets and further dried; c) a method in which EVOH and acids and metal salts thereof are mixed together and then melt-kneaded with an extruder or the like; d) a resin composition; A method in which acids and their metal salts are mixed together and then melt-kneaded with an extruder or the like. E) During production of EVOH, the alkali (sodium hydroxide, potassium hydroxide, etc.) used in the saponification step is acetic acid, etc. of Neutralized with kind, sodium acetate to acids and byproducts such as acetic acid remaining include a method in which to adjust the water washing treatment the amount of the alkali metal salts such as potassium acetate. 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 obtained by the above method a), i) 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. Examples of the material transfer type of the mold drying box type dryer include, but are not limited to, a band dryer, a tunnel dryer, and a vertical dryer. 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 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, particularly 0.1 to 1% by weight). If the water content is less than 0.001% by weight, long-run moldability tends to decrease. Conversely, if it exceeds 5% by weight, foaming occurs during extrusion molding. There is a fear that it is not preferable.

  Such EVOH has some monomer residues (3,4-diol-1-butene, 3,4-diacyloxy-1-butene, 3-acyloxy-4-ol-1 as long as the object of the present invention is not impaired. -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) and 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 a 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.

The resin composition of the present invention contains the above E V O H (A) and the oxygen-absorbing substance (B). Examples of the oxygen-absorbing substance (B) include reduced iron powder, Inorganic oxygen absorbers such as aluminum powder, potassium sulfite, and photocatalytic titanium oxide may be used, but organic compound-based oxygen absorbers are preferable in terms of good transparency. Acid, further fatty acid esters and metal salts thereof, hydroquinone, gallic acid, polyhydric phenols such as hydroxyl group-containing phenol aldehyde resin, bis-salicylaldehyde-imine cobalt, tetraethylenepentamine cobalt, cobalt-Schiff base complex, porphyrins Coordination of nitrogen-containing compounds such as macrocyclic polyamine complexes and polyethyleneimine-cobalt complexes with transition metals Body, terpene compound, reaction product of amino acids and hydroxyl group-containing reducing substance, triphenylmethyl compound, etc. Among them, high molecular oxygen absorber is preferable in terms of good hygiene, high molecular oxygen absorption Coordination conjugate of nitrogen-containing resin and transition metal (example: combination of M X D nylon and cobalt), blend of tertiary hydrogen-containing resin and transition metal (example: combination of polypropylene and cobalt), Carbon-carbon unsaturated bond-containing resin and oxidation catalyst blend, polyalkylene ether bond-containing resin and oxidation catalyst blend, photo-oxidative decay resin (eg, polyketone), anthraquinone polymer (eg, polyvinyl anthraquinone), etc. Among them, a combination of an oxidizable thermoplastic resin (B 1) and a metal oxide (B2) is an oxygen barrier property. Preferred for further improvement, such oxidizable thermoplastic resins (B 1) include nitrogen-containing resins (such as MXD nylon), tertiary hydrogen-containing resins (such as polypropylene), and carbon-carbon unsaturated bond content. resins, polyalkylene ether bond-containing resins, and among them, especially the polyalkylene emissions ether bond-containing resin (B 1 2) is not preferred.

Moreover, as a polymer (B12) which has a polyalkylene ether unit, if it is a polymer containing a polyalkylene ether unit, it may be a single polymer or a copolymer.
Examples of the polymer (B12) containing a polyalkylene ether unit include polymethylene glycol, polyethylene glycol, poly (1,2- and 1,3) propylene glycol, polytetramethylene glycol, polybutylene glycol, and polyhexamethylene glycol. In addition to the linear and branched aliphatic ethers, alicyclic ether homopolymers or copolymers such as cyclohexanediol condensates and cyclohexanedimethanol condensates. Further, a random copolymer in these ether units may be used. Also, block copolymers having polyalkylene ether units can be used. These block copolymers include polyester ether block copolymers using aromatic polyesters and polyalkylene ethers, aliphatic polyesters and polyalkylenes. A block copolymer using ether, a polyurethane copolymer having a unit composed of a polymer of short chain glycol and diisocyanate and a unit composed of a polymer of diisocyanate and polyalkylene ether, polyamide and polyalkylene ether were used. Examples thereof include polyamide polyether copolymers. Of these, polytetramethylene glycol is particularly preferred. The number average molecular weight of the polyalkylene ether unit is preferably from 600 to 4000 (more preferably from 800 to 2500, particularly 900 to 2100). When the number average molecular weight is less than 600, the melting point is increased and the ethylene-vinyl alcohol copolymer is used. When blending with a polymer, the meltability is lowered. On the other hand, when it exceeds 4000, the melting point is lowered and adhesion to a hopper or the like may occur at the time of blending. These polyalkylene ether units can be used alone or in combination of two or more different in number average molecular weight.
The polyester ether block copolymer using the above aromatic polyester and polyalkylene ether includes an aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, an aromatic dicarboxylic acid or an alkyl ester thereof, and A polyalkylene ether having an average molecular weight of 600 to 4,000 is used as a raw material, and an oligomer obtained by esterification or transesterification can be polycondensed.
As the aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, those usually used as a raw material for polyester can be used. Examples of the alkylene glycol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like, among which 1,4-butanediol is preferable. These diols can be used singly or as a mixture of two or more.
As the aromatic dicarboxylic acid, those generally used as a raw material for polyester can be used. For example, terephthalic acid and its lower alkyl ester, isophthalic acid, phthalic acid, 2,5-norbonane dicarboxylic acid, 1,4 -Naphthalic acid, 1, 5- naphthalic acid, 4, 4- oxybenzoic acid, 2, 6- naphthalene dicarboxylic acid, those lower alkyl esters, etc. are mentioned. Among these, terephthalic acid and isophthalic acid are preferable, and terephthalic acid is particularly preferable. Two or more of these aromatic dicarboxylic acids may be used in combination.
The above polyester ether block copolymers include “Polyester” (manufactured by Nippon Synthetic Chemical Industry), “Primalloy” (manufactured by Mitsubishi Chemical), “Perprene” (manufactured by Toyobo Co., Ltd.), “Hytrel” (DuPont) And other commercial products.
In the present invention, the polymer (B) having the polyalkylene ether unit may be acid-modified, and acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citrus acid, tetrahydrophthalate. Examples include acid-modified products obtained by graft polymerization of acids such as α, β-unsaturated carboxylic acids such as acids, unsaturated dicarboxylic acids, maleic anhydride, itaconic anhydride, citraconic anhydride, and tetrahydrophthalic anhydride onto the polymer (B). be able to.

  Moreover, as an oxidation catalyst (B2) used with said oxidizable thermoplastic resin (B1), a transition metal or its compound can be mentioned, As this transition metal, titanium, vanadium, chromium, manganese, iron, cobalt At least one selected from nickel, copper, zinc, zirconium, ruthenium, and palladium. Among them, cobalt is preferable from the viewpoint of compatibility with a resin, functionality as a catalyst, and safety. Further, the form of the compound is not particularly limited, and examples thereof include oxides, chlorides, organic acid salts, complexes, etc. In consideration of kneading into the resin, organic acid salts are preferable, and aliphatic compounds are particularly preferable. Carboxylic acid salts such as carboxylic acid, aromatic carboxylic acid, saturated carboxylic acid and unsaturated carboxylic acid are preferable, and stearic acid, palmitic acid, lauric acid, decanoic acid, octanoic acid, oleic acid are preferable in terms of good melt mixing Long chain alkyl fatty acid salts such as neodecanoic acid and linoleic acid are preferred, and stearic acid and neodecanoic acid are more preferred. The content of the transition metal is 0.001 to 1 part by weight (particularly 0.005 to 0.1 part by weight, more preferably 0.01 to 0.05 part by weight based on 100 parts by weight of EVOH (A) in terms of metal. Parts by weight).

  The resin composition of the present invention contains the EVOH (A) and the oxygen-absorbing substance (B), and the EVOH (A) and the oxygen-absorbing substance (B) in the resin composition are contained. The ratio is not particularly limited, but it is 99.5 / 0.5 to 50/50 (weight ratio, the same applies hereinafter) (further 99/1 to 55/45, particularly 98/2 to 60/40). Preferably, when the content of the oxygen-absorbing substance (B) is less than 0.5 parts by weight, the effect of the present invention cannot be obtained. On the contrary, when the content exceeds 50 parts by weight, the transparency of the molded product tends to decrease. Absent.

  The blending method of EVOH (A) and oxygen-absorbing substance (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 component to the extruder is not particularly limited. B) A method of dry-blending EVOH (A) and oxygen-absorbing substance (B) and supplying them to the extruder in a batch. A method in which either EVOH (A) or oxygen-absorbing substance (B) is supplied to an extruder and melted to supply the other solid (solid side feed method), c) EVOH (A) or oxygen Examples include a method (melt side feed method) in which any one of the absorptive substances (B) is supplied to an extruder and melted, and the other of the melted state is supplied (melt side feed method). The method is industrially practical in terms of the simplicity of the apparatus and the 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.), deodorants (activated carbon, etc.), heat stabilizers, light A stabilizer, an antioxidant, an ultraviolet absorber, a colorant, an antistatic agent, a surfactant, an antibacterial agent, an antiblocking agent, a slip agent, a filler (for example, an inorganic filler), other resins, etc. may be blended. .

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. Examples of the shape of the die include a T die and a round die. 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 and 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, it is not possible to say unconditionally, but 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, a graft reaction, etc. 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, rubber / elastomer components such as polyisobutylene, ethylene-propylene rubber, and the resin of the b layer. In particular, blending a polyolefin resin different from the base polyolefin resin of the adhesive resin is useful because the adhesiveness may be improved.

  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 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.

Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to the description of the examples unless it exceeds the gist.
In the examples, “parts” and “%” mean 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 carried out 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 the 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 at 10 kg / hour from the top of the methanol / water solution adjusting tower, methanol vapor at 120 ° C. was supplied at 4 kg / hour, and water vapor was supplied from the bottom of the tower at a rate of 2.5 kg / hour. The methanol was distilled from the top of the column at a rate of 8 kg / hr. 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 a column temperature of 95 to 110 ° C. A water / alcohol solution of EVOH (resin concentration 35%) was obtained from the bottom.

  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. 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 proton of 3,4-diacetoxy-1-butene (integrated 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, the same procedure was carried out except that the amount of methanol charged was 80 kg, and boric acid was not added. The ethylene content was 29 mol%, and the amount of structural units introduced with 1,2-glycol bonds was 2. An EVOH composition containing 5 mol% of 0.005 parts by weight of calcium dihydrogen phosphate (converted to phosphate radical) and MFR of 4.8 g / 10 min 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 containing (in terms of boron), 0.005 parts by weight of calcium dihydrogen phosphate (in terms of phosphate group), and MFR of 3.7 g / 10 min was obtained.

  Separately, ethylene content 29 mol% not containing structural unit (1), saponification degree 99.5 mol%, MFI = 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 calcium dihydrogen phosphate (in terms of phosphate radical) was prepared.

Example 1
To 100 parts of the EVOH composition (A1) obtained above, 0.4 / 0.1 / 0.5 (1,4-butanediol, polytetramethylene glycol, terephthalic acid as the oxygen-absorbing substance (B) ( (Copolymerization molar ratio) 5 parts of copolymer resin (B1) and 0.023 parts by weight of cobalt stearate (B2) (metal conversion) were blended and fed to a 30 mmφ twin screw extruder and melt mixed at 210 ° C. A pellet of the resin composition was obtained.

  The pellets (resin composition) obtained above were supplied to a 40 mmφ single screw extruder and extruded from a 400 mm wide single layer T die onto a roll at 80 ° C. at 210 ° C. to obtain a single layer film having a thickness of 15 μm. .

About the obtained single layer film, gas-barrier property and transparency were evaluated as follows.
(Gas barrier properties)
Oxygen permeability (cc / m ² · day · atm) was measured using an oxygen permeability measuring device “OX-TRAN 2/20” manufactured by MOCON under the conditions of 23 ° C. and 90% RH.

(transparency)
Using a “NDH2000 haze meter” manufactured by Nippon Denshoku Co., Ltd., the haze value was measured and the transparency was evaluated.

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 evaluation was performed in the same manner.

Comparative Example 3
A resin composition was prepared in the same manner as in Example 1 except that 5 parts of polybutadiene (B 1) was blended in place of 1,4-butanediol / polytetramethylene glycol / terephthalic acid copolymer resin (B 1). Was evaluated.

Comparative Example 1
In Example 1, it evaluated similarly except not having mix | blended the oxygen absorptive substance (B).

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.

[Table 1]

  Since the resin composition of the present invention has good gas barrier properties and excellent transparency, when processed into a film, it exhibits excellent gas barrier properties even at high temperatures, high humidity, and thin film thicknesses. It is useful as various packaging materials such as pharmaceutical packaging materials, industrial chemical packaging materials, and agricultural chemical packaging materials.

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 (9)

An ethylene-vinyl alcohol copolymer (A) containing the following structural unit (1) and an oxygen-absorbing substance (B) are contained , and the ethylene content of the ethylene-vinyl alcohol copolymer (A) is 10 to 10. 60 mol%, the degree of saponification is 90 mol% or more, the structural unit amount of the structural unit (1) is 0.1 to 30 mol%, and the melt flow rate (210 ° C, weight 2160 g) is 0.1. 1 to 100 g / 10 min, the oxygen-absorbing substance (B) is composed of an oxidizable thermoplastic resin (B1) and an oxidation catalyst (B2), and the oxidizable thermoplastic resin (B1) is It is a polymer (B12) having a polyalkylene ether unit, and the content ratio of the ethylene-vinyl alcohol copolymer (A) and the oxygen-absorbing substance (B) in the resin composition is 99.5 / 0.5. ~ 50 / 0 resin composition, which is a (weight ratio).

(Here, X is an alkylene chain having 5 or less carbon atoms , R 1 to R 4 are hydrogen atoms , and n represents 0 or 1.) Oxidation catalyst (B 2) is a transition metal or a resin composition according to claim 1, characterized in that a compound thereof. The resin composition according to claim 2 , wherein the transition metal is cobalt. It claims 1 to 3, the resin composition according to any one of n, characterized in that it is 0 the structural unit (1). The tree composition according to any one of claims 1 to 4, wherein the structural unit (1) is introduced into the molecular chain of the ethylene-vinyl alcohol copolymer (A) by copolymerization. The ethylene-vinyl alcohol copolymer (A) is obtained by saponifying a copolymer of 3,4-diacyloxy-1-butene, a vinyl ester monomer and ethylene. 5. The resin composition according to any one of 5 . The ethylene-vinyl alcohol copolymer (A) is obtained by saponifying a copolymer of 3,4-diacetoxy-1-butene, a vinyl ester monomer and ethylene. 6. The resin composition according to any one of 6 . The ethylene-vinyl alcohol copolymer (A) converted the boron compound into an ethylene-vinyl alcohol copolymer 100 parts by weight in terms of boron with respect to 10 parts by weight. The resin composition according to any one of claims 1 to 7, which is contained in an amount of 0 0 1 to 1 part by weight. A multilayer structure comprising at least one layer of the resin composition according to any one of claims 1 to 8 .

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