JP4117232B2 - Resin composition and method for producing the same - Google Patents

Description

  The present invention relates to a resin composition comprising an ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) and a modified ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as modified EVOH), and the same. It relates to a manufacturing method.

  An ethylene-vinyl alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is a useful polymer material excellent in oxygen shielding properties, oil resistance, non-charging properties, mechanical strength, etc. Widely used as packaging material. There are various methods for forming EVOH pellets into various molded products, but they are often melt-molded like extrusion molding or injection molding. However, since the melting temperature must normally be 200 ° C. or higher when molding EVOH resin, EVOH that does not contain additives tends to deteriorate during melt molding, causing fish eyes and blisters to the product and reducing the quality. There was sometimes. In addition, it is necessary to add an additive in order to improve the interlaminar adhesion at the time of use with another resin.

  WO99 / 005213 pamphlet (US Pat. No. 6,174,949) includes at least one selected from a boron compound as an essential component, acetic acid as an optional component, and an acetate and a phosphate compound as an essential component. The content of each component with respect to 100 parts by weight of EVOH, the boron compound is 0.001 to 1 part by weight in terms of boron, the acetic acid is 0 to 0.05 parts by weight, and the acetate is 0 in terms of metal. An EVOH resin composition in which 0.001 to 0.05 parts by weight and the phosphoric acid compound is 0.0005 to 0.05 parts by weight in terms of phosphate group is described. This resin composition is said to be an EVOH resin composition with improved long run properties, appearance, and interlayer adhesion. Here, it is described that the purpose of blending acetate is to improve long run properties and interlayer adhesion.

  Japanese Patent Application Laid-Open No. 2001-164059 (European Patent Application Publication No. 1090953) is an EVOH resin composition characterized in that its MFR exhibits a specific behavior when the resin composition is heated and melted. Carboxylic acid having a molecular weight of less than 75 is 50 to 500 ppm, alkali metal salt is 50 to 500 ppm in terms of metal element, alkaline earth metal salt is 10 to 120 ppm in terms of metal element, phosphate compound is 10 to 200 ppm in terms of phosphate group, A resin composition containing 50 to 2000 ppm of a boron compound in terms of boron element is described. This resin composition is said to be an EVOH resin composition that is excellent in appearance and long run property during melt molding, little colored during recovery, and excellent in interlayer adhesion when formed into a laminate. Here, an alkali metal salt is added to improve interlayer adhesion, and a boron compound is added to improve long-run properties.

  As a method for producing EVOH pellets containing the additive, a method in which EVOH hydrous pellets are brought into contact with an aqueous solution containing the additive is described as a representative method. According to this method, it is easy to control the amount of trace components contained in the EVOH pellets by adjusting the solution concentration, and it is possible to obtain stable quality pellets by drying after contacting with the aqueous solution.

  As described above, in order to improve interlayer adhesion, an alkali metal salt is added to the EVOH resin, and is typically added as an acetate salt. In many cases, acetic acid not forming a salt is also added at the same time. However, the EVOH resin composition containing an acetate group in this way sometimes gives off an acetic acid odor. One of the main uses of the EVOH resin composition is a food packaging container, and there has been a demand for an EVOH resin composition with less odor generation in the market. Further, an EVOH resin composition having improved melt stability and excellent long run properties is desired.

  On the other hand, when EVOH hydrous pellets are brought into contact with an aqueous solution containing acetic acid or acetate to produce EVOH resin composition pellets, acetic acid is released into the atmosphere when the hydrous pellets after contact are dried. In many cases, the surrounding environment and work environment may be adversely affected.

  EVOH is excellent in transparency and gas barrier properties, but has drawbacks that lack stretchability, flexibility, and bending resistance. In order to improve this defect, a method of blending EVOH with a flexible resin such as ethylene-vinyl acetate copolymer or ethylene-propylene copolymer is known. However, this method has a drawback that the transparency is greatly reduced.

  International Publication No. 02/092643 pamphlet (Patent Document 3) describes a modified EVOH containing 5 to 55 mol% of ethylene having 0.3 to 40 mol% of the following structural unit (I). The modified EVOH is excellent in barrier properties, transparency, stretchability, flexibility and bending resistance, and is used for various molded products as a single layer or a multilayer structure. For example, it is described that it can be used for a co-injection blow molded container, a thermoformed product, a stretched film, and the like. Moreover, it describes that other resin and various fillers may be mix | blended with the said modified EVOH.

(In the formula, R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or 6 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same or different, and R ³ and R ⁴ may be bonded to each other. R ¹ , R ² , R ³ and R ⁴ may have a hydroxyl group, a carboxyl group or a halogen atom.)

International Publication No. 99/005213 Pamphlet JP 2001-164059 A International Publication No. 02/092643 Pamphlet

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a resin composition excellent in barrier properties, flexibility, secondary processability and transparency. It is another object of the present invention to provide a method for producing a resin composition comprising EVOH and modified EVOH, which does not discharge carboxylic acid such as acetic acid to the surrounding environment and is environmentally friendly.

  The said subject contains 0.1-20 micromol / g of alkali metal salt (A) in conversion of an alkali metal, and 0-2 micromol / g of carboxylic acid root (C1) extracted by immersing in 95 degreeC water for 10 hours. And an ethylene-vinyl alcohol copolymer resin composition (F) containing 0 to 40 μmol / g of carboxylic acid radical (C2) extracted by immersion in a 0.05 N aqueous sodium hydroxide solution at 95 ° C. for 10 hours. 1) to 99% by weight, 1 to 99% by weight of a modified ethylene-vinyl alcohol copolymer (G) having an ethylene content of 5 to 55% by mole containing 0.3 to 40% by mole of the following structural unit (I) This is solved by providing a resin composition comprising:

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same group. And may be different . )

  Moreover, the said subject contains 0.1-20 micromol / g of alkali metal salt (A) in conversion of an alkali metal, Carboxylic acid root (C1) extracted by immersing it in 95 degreeC water for 10 hours is 0-2 micromol /. 1 to 99% by weight of ethylene-vinyl alcohol copolymer resin composition (F) having a saponification degree of 99.7 to 100 mol% and 0.3 to 40 of the following structural unit (I): It is also solved by providing a resin composition comprising 1 to 99% by weight of a modified ethylene-vinyl alcohol copolymer (G) having an ethylene content of 5 to 55 mol%.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same group. And may be different . )

  In these resin compositions, the alkali metal salt (A) is preferably a potassium salt. It is also preferable that the ethylene-vinyl alcohol copolymer resin composition (F) contains the boron compound (B) in an amount of 1 to 200 μmol / g in terms of boron element. It is also preferable that the phosphorus element content (t) of the ethylene-vinyl alcohol copolymer resin composition (F) is 0.05 to 5 μmol / g in terms of phosphorus element. Furthermore, a molded product formed by molding the resin composition is a preferred embodiment of the present invention.

Moreover, the said subject is after making ethylene-vinyl alcohol copolymer resin contact the aqueous solution containing 0.05-40 mmol / L of alkali metal salt (A) and containing the carbon dioxide gas of 0.5 mmol / L or more. The resin composition, wherein the resin composition is melt kneaded with a modified ethylene-vinyl alcohol copolymer (G) having an ethylene content of 5 to 55 mol% and containing 0.3 to 40 mol% of the following structural unit (I): This problem can also be solved by providing a manufacturing method.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same group. And may be different . )

  The resin composition of the present invention is excellent in barrier properties, flexibility, secondary processability and transparency. Moreover, the manufacturing method of the resin composition of this invention considers the environment without discharging | emitting carboxylic acid, such as an acetic acid, to the surrounding environment.

  First, the manufacturing method of EVOH resin composition (F) used by this invention is demonstrated. A suitable production method includes an ethylene-vinyl alcohol copolymer in an aqueous solution containing at least one additive selected from the group consisting of an alkali metal salt (A) and a boron compound (B) and containing carbon dioxide gas. This is a manufacturing method in which a resin is brought into contact.

  Conventionally, in order to make an EVOH resin contain at least one additive selected from the group consisting of an alkali metal salt (A) and a boron compound (B), EVOH is brought into contact with an aqueous solution containing these additives. The way was done. The EVOH resin composition (F) used in the present invention is characterized in that it is brought into contact with an aqueous solution containing carbon dioxide gas in addition to the above additives.

  In order to improve interlayer adhesion in a multilayer structure including a resin composition layer comprising an EVOH resin composition (F) and a modified EVOH (G), the EVOH resin composition (F) contains an alkali metal salt (A). Therefore, the EVOH resin is often immersed in an aqueous solution containing an alkali metal salt (A), particularly an alkali metal acetate. At this time, if the liquid to be immersed is kept alkaline, the stability at the time of melt molding is often lowered, and in order to solve this problem, an acid, particularly a carboxylic acid typified by acetic acid, is often contained separately.

  However, when the content of carboxylic acid radicals derived from carboxylic acids and carboxylates is high, the EVOH resin composition often generates a carboxylic acid odor, which may be a problem when used for food packaging applications. was there. In addition, there has been a problem that carboxylic acid is released to the surrounding environment when it is dried after being brought into contact with an aqueous solution containing an additive. Accordingly, there has been a demand for a method that does not make the aqueous solution containing the additive alkaline, while containing the alkali metal salt (A) and minimizing the content of carboxylic acid radicals. The EVOH resin composition (F) used in the present invention can solve this problem by containing carbon dioxide gas in an aqueous solution containing an alkali metal salt (A) instead of using acetic acid.

  Moreover, in order to improve the long run property when the resin composition comprising the EVOH resin composition (F) and the modified EVOH (G) is melt-molded, it is desirable to add a boron compound (B) to the EVOH resin, Therefore, the EVOH resin is often immersed in an aqueous solution containing the boron compound (B). However, depending on the application, even if the boron compound (B) is contained, the long run property may still be insufficient, and further improvements are desired.

  The EVOH resin composition (F) used in the present invention can be further improved by adding carbon dioxide gas to an aqueous solution containing a boron compound (B). That is, by using an aqueous solution containing carbon dioxide gas, the content of the carboxylic acid radical is reduced, and the boron compound (B) is further added to obtain an EVOH resin composition (F) excellent in long run properties. Can do. And it becomes possible to obtain the resin composition excellent in long run property which consists of the said EVOH resin composition (F) and modified | denatured EVOH (G).

  As EVOH used in the present invention, those obtained by saponifying an ethylene-vinyl ester copolymer are preferable, and those obtained by saponifying an ethylene-vinyl acetate copolymer are particularly preferable. From the viewpoint of obtaining a molded article excellent in gas barrier properties and melt moldability, the ethylene content is preferably 5 to 60 mol%. When the ethylene content is less than 5 mol%, the melt moldability may be deteriorated, and when the ethylene content exceeds 60 mol%, the gas barrier property may be insufficient. The lower limit of the ethylene content is more preferably 15 mol% or more, and even more preferably 20 mol% or more. On the other hand, the upper limit of the ethylene content is more preferably 55 mol% or less, and even more preferably 50 mol% or less.

  The saponification degree of the vinyl acetate component is preferably 80 to 100 mol%. From the viewpoint of obtaining a molded article excellent in gas barrier properties, it is more preferably 95 mol% or more, further preferably 98 mol% or more, and particularly preferably 99 mol% or more. If the saponification degree is less than 80 mol%, the barrier property, long run property, and moisture resistance may be deteriorated. In particular, in the case of producing an EVOH composition having excellent melt stability and long run property, the saponification degree of EVOH is preferably 99.7 mol% or more, and 99.8 mol% or more. More preferably, it is 99.9 mol% or more, more preferably 99.95 mol% or more.

  Further, when ethylene and vinyl acetate are copolymerized, other fatty acid vinyl esters (vinyl propionate, vinyl pivalate, etc.) can be used in combination. Moreover, EVOH can contain 0.0002-0.2 mol% of vinyl silane compounds as a copolymerization component. Here, examples of the vinylsilane compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (β-methoxy-ethoxy) silane, and γ-methacryloxypropylmethoxysilane. Of these, vinyltrimethoxysilane and vinyltriethoxysilane are preferably used.

  The EVOH production method will be specifically described below. The polymerization of ethylene and vinyl acetate is not limited to solution polymerization, and may be any of solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, and may be either continuous or batch-type. The polymerization conditions in the case of polymerization are as follows.

Solvent: Alcohols are preferred, but other organic solvents (such as dimethyl sulfoxide) that can dissolve ethylene, vinyl acetate, and ethylene-vinyl acetate copolymer can be used. As alcohols, methyl alcohol, ethyl alcohol, propyl alcohol, n-butyl alcohol, t-butyl alcohol and the like can be used, and methyl alcohol is particularly preferable.
Catalyst: 2,2-azobisisobutyronitrile, 2,2-azobis- (2,4-dimethylvaleronitrile), 2,2-azobis- (4-methyl-2,4-dimethylvaleronitrile), 2 , 2-azobis- (4-methoxy-2,4-dimethylvaleronitrile), 2,2-azobis- (2-cyclopropylpropionitrile) and the like azonitrile initiators, isobutyryl peroxide, cumylperoxyneo Organic peroxides such as decanoate, diisopropyl peroxycarbonate, di-n-propyl peroxydicarbonate, t-butyl peroxyneodecanoate, lauroyl peroxide, benzoyl peroxide, t-butyl hydroperoxide An initiator or the like can be used.
Temperature; 20-90 ° C, preferably 40 ° C-70 ° C.
Time (average residence time in case of continuous type); 2 to 15 hours, preferably 3 to 11 hours.
Polymerization rate: 10 to 90%, preferably 30 to 80%, relative to the charged vinyl ester.
Resin content in the solution after polymerization; 5 to 85%, preferably 20 to 70%.
Ethylene content in the copolymer; preferably 5 to 60 mol%, more preferably 15 to 55 mol%, optimally 20 to 50 mol%.

  In addition to ethylene and vinyl acetate, monomers that can be copolymerized with these, for example, α-olefins such as propylene, isobutylene, α-octene, α-dodecene; acrylic acid, methacrylic acid, crotonic acid, maleic acid, itacone Unsaturated acids such as acids or their anhydrides, salts, mono- or dialkyl esters, etc .; Nitriles such as acrylonitrile and methacrylonitrile; Amides such as acrylamide and methacrylamide; Ethylene sulfonic acid, allyl sulfonic acid, methallyl sulfone An olefin sulfonic acid such as an acid or a salt thereof; alkyl vinyl ethers, vinyl ketone, N-vinyl pyrrolidone, vinyl chloride, vinylidene chloride and the like can also be present in a small amount.

  After polymerization for a predetermined time, after reaching a predetermined polymerization rate, a polymerization inhibitor is added if necessary, and unreacted ethylene gas is removed by evaporation, and then unreacted vinyl acetate is driven off. As a method of driving off unreacted vinyl acetate from the ethylene-vinyl acetate copolymer solution from which ethylene has been removed by evaporation, for example, the copolymer solution is continuously supplied at a constant rate from the upper part of a tower packed with Raschig rings, A method in which an organic solvent vapor such as methanol is blown from the bottom of the tower, a mixed vapor of an organic solvent such as methanol and unreacted vinyl acetate is distilled from the top of the tower, and the copolymer solution from which the unreacted vinyl acetate has been removed is removed from the bottom of the tower Etc. are adopted.

An alkali catalyst is added to the copolymer solution from which unreacted vinyl acetate has been removed to saponify the vinyl acetate component in the copolymer. The saponification method can be either continuous or batch. As the alkali catalyst, sodium hydroxide, potassium hydroxide, alkali metal alcoholate or the like is used. Moreover, as a solvent used for saponification, methanol is preferable. For example, the saponification conditions are as follows.
The copolymer solution concentration: 10 to 50%.
Reaction temperature: 30-150 ° C.
Amount of catalyst used: 0.005 to 0.6 equivalent (per vinyl acetate component).
Time (in the case of continuous type, average residence time); 10 minutes to 6 hours.

In general, when saponification is performed continuously, methyl acetate produced by saponification can be removed more efficiently, so that a resin having a high saponification degree can be obtained with a smaller amount of catalyst than in the case of batch-wise. In the case of a continuous type, it is necessary to saponify at a higher temperature in order to prevent precipitation of EVOH produced by saponification. Therefore, it is preferable to set the reaction temperature and the catalyst amount within the following ranges in the continuous method.
Reaction temperature: 70-150 ° C.
Amount of catalyst used: 0.005 to 0.1 equivalent (per vinyl acetate component).

  The degree of saponification after the saponification reaction varies depending on the purpose, but is preferably 80 mol% or more, more preferably 95 mol% or more, still more preferably 98 mol% or more, particularly preferably 99 mol% or more of the vinyl acetate component. The degree of saponification can be arbitrarily adjusted according to the conditions.

  As described above, in the case of producing an EVOH composition having excellent melt stability and long run property, the saponification degree of EVOH is preferably 99.7 mol% or more, and 99.8 mol%. More preferably, it is more preferably 99.9 mol% or more, and particularly preferably 99.95 mol% or more. In order to obtain such EVOH, the saponification conditions are further reduced as follows. It is preferable to adjust as follows.

  As a method for obtaining EVOH having a high saponification degree of 99.9 mol% or more, a continuous method is preferable. As a method for obtaining a high saponification degree in a continuous manner, for example, a method of adding a catalyst from a plurality of locations in a saponification reaction tower, a method of increasing the amount of catalyst used, and a large amount of methanol blown from the lower part of the saponification reaction tower. The method of doing is mentioned. Moreover, as a method for obtaining EVOH having a high saponification degree of 99.9 mol% or more by batch method, for example, a method of adding a catalyst in a plurality of times, a method of increasing the amount of catalyst used, a saponification For example, a method of increasing the amount of methanol vapor or nitrogen gas blown into the reaction vessel may be used.

  The method for producing EVOH pellets from the obtained alcohol solution of EVOH after saponification is not particularly limited. Preferably, an alcohol solution of EVOH is precipitated in a strand form in a coagulation bath, and then the strands are cut to obtain water-containing pellets. In the precipitation, the alcohol solution may be concentrated to increase the EVOH concentration as compared with the saponification, or a part or all of methanol may be replaced with water, and the EVOH water / alcohol mixed solution or A water-containing composition of EVOH may be used. A water-containing pellet is obtained by extruding this into water or an alcohol aqueous solution containing a small amount of alcohol, and precipitating it into a strand shape, followed by cutting. Moreover, it can cut | disconnect with a fluid state, without making it precipitate in a strand form, and can also solidify in water and can manufacture a pellet.

  The water-containing pellets obtained as described above are porous, and the saponification catalyst residue can be easily removed by washing with water, and the subsequent addition of additives and drying operations are also easy. It is preferable that the moisture content of such a water-containing pellet is 10 to 80% by weight because of the above operational advantages. The water content is more preferably 20% by weight or more, and further preferably 30% by weight or more. Moreover, it is 70 weight% or less more suitably, More preferably, it is 60 weight% or less.

  The water-containing pellets thus obtained usually contain an alkali metal salt that is a saponification catalyst residue, for example, sodium acetate, which causes problems such as coloring, and thus is preferably removed by washing. Usually, the alkali metal salt content of the water-containing pellets before washing is about 100 to 10,000 μmol / g (per EVOH weight) in terms of alkali metal. The cleaning method is not particularly limited, but a method of cleaning with water is preferable. The water used as the cleaning liquid at this time may be an aqueous solution of an acid such as acetic acid in order to efficiently remove alkali metal ions. Moreover, it is also preferable to reduce the content of the saponification catalyst residue efficiently by using water washing and acid washing together.

  It is preferable to reduce the alkali metal content of the water-containing pellets after washing to 0-50 μmol / g (per EVOH weight) in terms of alkali metal. The upper limit of the alkali metal content is more preferably 40 μmol / g, still more preferably 30 μmol / g, and particularly preferably 20 μmol / g. Since the saponification catalyst residue is usually contained in the form of an alkali metal salt of acetic acid, the content of carboxylic acid radicals was reduced by sufficiently reducing the alkali metal content of the water-containing pellets after washing. It becomes easy to obtain an EVOH composition.

  The method for washing the water-containing pellets is not particularly limited, and either a batch type processing container or a continuous type processing container can be used. Especially, the method of supplying and processing a pellet continuously in a tower type container is suitable from a viewpoint of productivity.

  The EVOH resin composition (F) used in the present invention contains at least one additive selected from the group consisting of alkali metal salts (A) and boron compounds (B), and contains carbon dioxide gas. A method for producing an EVOH resin composition (F) in which an EVOH resin is brought into contact with an aqueous solution is suitably employed. At this time, the aqueous solution in contact with the EVOH resin is an aqueous solution containing at least one additive selected from the group consisting of an alkali metal salt (A) and a boron compound (B) and containing carbon dioxide gas. .

  The amount of carbon dioxide gas contained in the aqueous solution is not particularly limited and can be appropriately adjusted. However, the amount of carbon dioxide gas present in the air is more than the amount that naturally dissolves carbon dioxide gas. It is necessary to let The concentration of carbon dioxide gas in the aqueous solution (total of free carbon dioxide and carbonic acid) is preferably 0.5 mmol / L or more, more preferably 2 mmol / L or more, and further preferably 10 mmol / L or more. . Moreover, in order to raise the solubility of a carbon dioxide gas, you may process on pressurization conditions of about 1.5-10 atmospheres.

  When a continuous processing vessel, particularly a tower type vessel, is used to continuously feed and process pellets, when the concentration of carbon dioxide in the aqueous solution is too high, bubbles are generated around the EVOH pellets. In some cases, the resin sedimentation may be adversely affected. Therefore, when such a continuous processing process is applied, it may be preferable that the carbon dioxide concentration in the aqueous solution is lower than the saturated carbon dioxide concentration. In this case, the carbon dioxide concentration is set to a value less than the saturated carbon dioxide concentration, preferably 0.95 times or less of the saturated carbon dioxide concentration, more preferably 0.9 times or less the saturated carbon dioxide concentration. The This concentration is determined by affecting the temperature and pressure of the treatment liquid. On the other hand, when a batch-type processing container is used, the above problem of sedimentation usually does not occur, but the upper limit value of the carbon dioxide gas concentration can be set in the same manner as in the continuous processing container.

  The aqueous solution preferably contains an alkali metal salt (A) from the viewpoint of securing interlayer adhesion and long run properties. The preferred range of the content of the alkali metal salt (A) is affected by the water content of the water-containing pellets, but generally it is preferably 0.05 to 40 mmol / L. A more preferable lower limit of the content of the alkali metal salt (A) in the aqueous solution is 0.1 mmol / L. A more preferred upper limit is 20 mmol / L. As will be described later, the preferred content of the alkali metal salt (A) in the EVOH resin composition (F) varies depending on the ethylene content of EVOH, and accordingly, the alkali metal salt ( It is preferable to adjust the content of A).

  The cation species of the alkali metal salt (A) is not particularly limited. It is selected from lithium, sodium, potassium, rubidium and cesium salts, with sodium and potassium salts being preferred, and potassium being particularly preferred. By using the potassium salt, a resin composition composed of the EVOH resin composition (F) and the modified EVOH (G), which is excellent in both interlaminar adhesion and long run property, can be obtained.

  The anion species of the alkali metal salt (A) is not particularly limited. Can be added as carbonate, bicarbonate, phosphate, hydrogen phosphate, hydroxide, carboxylate, etc. Among them, added as carbonate, bicarbonate, hydrogen phosphate and hydroxide It is preferable to do. Moreover, it is also preferable to add as a borate as shown below. However, in view of the purpose of the present invention to reduce the content of carboxylate groups, it is better not to be a carboxylate.

  Moreover, it is preferable that the said aqueous solution contains a boron compound (B) from the point which can suppress generation | occurrence | production to the eye | mouth of the die lip part at the time of melt molding. When the concentration of the boron compound (B) in the aqueous solution is 0.1 to 50 mmol / L in terms of boron element, an appropriate amount of the boron compound (B) can be contained in the dry resin composition pellets. It is preferable. The lower limit value of the concentration of the boron compound (B) is more preferably 0.5 mmol / L or more, and further preferably 1 mmol / L or more. The upper limit is more preferably 40 mmol / L or less, and even more preferably 30 mmol / L or less. When it exceeds 50 mmol / L, the EVOH resin composition (F) is easily gelled, and the appearance of the molded product may be deteriorated.

  Examples of the boron compound (B) used for the preparation of the aqueous solution include, but are not limited to, boric acids, boric acid esters, borates, borohydrides, and the like. Specific examples of boric acids include orthoboric acid, metaboric acid, and tetraboric acid. Examples of boric acid esters include triethyl borate and trimethyl borate. Examples include alkali metal salts of acids, alkaline earth metal salts, and borax. Among these compounds, orthoboric acid (hereinafter sometimes simply referred to as boric acid) is preferable.

  Moreover, it is desirable for the said aqueous solution not to contain carboxylic acid or its salt (C) from the meaning of this invention. However, this does not exclude that the carboxylic acid or its salt (C) remaining in the EVOH resin dissolves into the aqueous solution and is contained as a result. Moreover, it does not exclude containing carboxylic acid or its salt (C) in the range which does not inhibit the effect of this invention.

  In order to balance the long run property and the color resistance at the time of melt molding, particularly the color resistance at the time of high temperature molding and the interlayer adhesion, the aqueous solution preferably contains a phosphoric acid compound (D). By containing an appropriate amount of the phosphoric acid compound (D), it is possible to suppress coloring of the molded product and generation of gels and blisters when the obtained EVOH resin composition (F) is melt-molded. The upper limit of the concentration of the phosphoric acid compound (D) in the aqueous solution when adding the phosphoric acid compound (D) is preferably 10 mmol / L, more preferably 5 mmol / L in terms of phosphate radical. More preferably, it is 3.5 mmol / L, and most preferably 2.5 mmol / L. On the other hand, the lower limit value of the concentration of the phosphoric acid compound (D) in the aqueous solution when adding the phosphoric acid compound (D) is preferably 0.01 mmol / L, more preferably 0 in terms of phosphate radical. 0.03 mmol / L, more preferably 0.05 mmol / L, and most preferably 0.1 mmol / L.

  As the phosphoric acid compound (D) used for the preparation of the aqueous solution, an inorganic phosphoric acid compound is preferably used, and various acids such as phosphoric acid and phosphorous acid and salts thereof are exemplified. The phosphate may be contained in any form of primary phosphate, secondary phosphate, and tertiary phosphate, and its cationic species is not particularly limited, but alkali metal salts It is preferable that Among these, it is preferable to add the phosphoric acid compound (D) in the form of sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, or dipotassium hydrogen phosphate.

  The aqueous solution may contain an alkaline earth metal salt (E). However, since the alkaline earth metal salt tends to form a hardly soluble carbonate, it is not appropriate to add it in a large amount. Depending on the application, it may be possible to improve the long run property when the obtained EVOH resin composition (F) is melt-molded by adding an appropriate amount. The addition of the alkaline earth metal salt (E) is optional, but the concentration of the alkaline earth metal salt (E) in the aqueous solution when added is in the range of 0 to 10 mmol / L in terms of alkaline earth metal. It is preferable that the alkaline earth metal salt (E) can be contained in the dry resin composition pellets. The upper limit is more preferably 5 mmol / L or less, and further preferably 3 mmol / L or less.

  The cationic species of the alkaline earth metal salt (E) is not particularly limited. Magnesium salts, calcium salts, barium salts, strontium salts and the like can be mentioned, and magnesium salts and calcium salts are preferred. The anionic species of the alkaline earth metal salt (E) is not particularly limited. Can be added as carbonate, bicarbonate, phosphate, hydrogen phosphate, hydroxide, carboxylate, etc. Among them, added as carbonate, bicarbonate, hydrogen phosphate and hydroxide It is preferable to do. Usually, the above alkaline earth metal salts are hardly soluble in water, but the solubility increases due to the presence of carbonic acid. However, in view of the purpose of the present invention to reduce the content of carboxylate groups, it is better not to be a carboxylate.

  The pH of the aqueous solution containing the additive and carbon dioxide gas is preferably 3.5 to 6.5. By containing a certain amount or more of carbon dioxide gas, such an acidic aqueous solution can be obtained. The pH value is more preferably 3.8 or more, and further preferably 4 or more. Further, the pH value is more preferably 6.3 or less, further preferably 6.0 or less, and most preferably 5.8 or less.

  The method for preparing the aqueous solution containing the additive and carbon dioxide gas is not particularly limited. You may add at least 1 sort (s) of additives selected from the group which consists of an alkali metal salt (A) and a boron compound (B) in the aqueous solution which melt | dissolved the carbon dioxide gas previously. Conversely, carbon dioxide gas may be dissolved in an aqueous solution in which at least one additive selected from the group consisting of alkali metal salts (A) and boron compounds (B) is dissolved in advance. Alternatively, each aqueous solution may be prepared in advance and then mixed.

  A method of bringing the EVOH resin into contact with the aqueous solution is not particularly limited, but a method of immersing the EVOH resin in the aqueous solution is desirable. The shape of the EVOH resin at the time of immersing the EVOH resin in the aqueous solution may be any shape such as powder, granular, spherical, cylindrical pellet, etc. For example, the water-containing EVOH pellet obtained as described above is used. It is preferable to contact the aqueous solution. By immersing the pellet in the water-containing state in the aqueous solution, the alkali metal salt (A) or the boron compound (B) can be efficiently and uniformly contained in the EVOH resin pellet. The water content of the water-containing pellets before being immersed in the aqueous solution is preferably 10 to 80% by weight. The water content is more preferably 20% by weight or more, and further preferably 30% by weight or more. Moreover, it is 75 weight% or less more suitably, More preferably, it is 70 weight% or less.

  The temperature of the aqueous solution brought into contact with the EVOH resin is not particularly limited, but is preferably 10 to 90 ° C. If it is less than 10 degreeC, there exists a possibility that it may take time to make an alkali metal salt (A) or a boron compound (B) contain uniformly in EVOH resin pellet, and when it exceeds 90 degreeC, the saturation solubility of a carbon dioxide gas will fall. In addition, it may be difficult to contain a sufficient amount of carbon dioxide gas in the solution, and the pellets may be fused. The temperature of the aqueous solution is more preferably 20 ° C. or higher, and further preferably 30 ° C. or higher. Moreover, it is 85 degreeC or less more suitably, More preferably, it is 80 degreeC or less. In the case of contact at a high temperature of 70 ° C. or higher, the solubility of carbonic acid is reduced.

  The preferred range of time for contacting the EVOH resin with the aqueous solution varies depending on the form of the EVOH resin, but in the case of pellets of about 1 to 10 mm, it is preferably 1 hour or more, more preferably 2 hours or more. preferable.

  A method for bringing the EVOH resin into contact with the aqueous solution is not particularly limited. The EVOH resin can be brought into contact with water in advance, and the carbon dioxide gas and the additive can be dissolved in water later. However, the method in which the aqueous solution prepared by dissolving these in advance is brought into contact with the EVOH resin is used as an additive. A stable quality EVOH resin composition (F) containing uniformly is obtained, which is preferable.

  As a method of bringing the EVOH resin into contact with the aqueous solution, either a batch method or a continuous method can be adopted. In the continuous method, for example, a method in which the EVOH resin is brought into contact with the continuously supplied aqueous solution while gradually moving the EVOH resin downward in a tower-shaped container is preferable.

  Also, a plurality of aqueous solutions may be prepared and contacted in a plurality of times. For example, after first contacting with an aqueous solution containing only the alkali metal salt (A) or boron compound (B), carbon dioxide is also contained in addition to the alkali metal salt (A) or boron compound (B). A method of contacting with an aqueous solution to be used can also be adopted.

  Furthermore, the EVOH resin is immersed in an aqueous solution containing carbon dioxide gas in addition to the alkali metal salt (A) or the boron compound (B), and then brought into contact with the solution. It is also possible to employ a method in which (A), a boron compound (B), a phosphoric acid compound (D) or an alkaline earth metal salt (E) is brought into contact with an aqueous solution and melt-kneaded.

  The EVOH resin, preferably the EVOH resin pellet, is brought into contact with the aqueous solution, and then drained as necessary before being subjected to a drying step. The drying method is not particularly limited, and a hot air dryer or the like can be used, and drying may be performed while melt-kneading in an extruder with a vent. The dryer may be a fluid dryer or a stationary dryer, and may be used in combination. Among these, a method of drying by a fluidized drying method first and then drying by a stationary drying method is preferable. The drying temperature is not particularly limited, but usually a temperature of about 70 to 120 ° C. is adopted, and the temperature can be raised as the drying proceeds. The water content after drying is usually 1% by weight or less, preferably 0.5% by weight or less. The dry pellets thus obtained are melt kneaded with the modified EVOH (G).

  In the method for producing the EVOH resin composition (F) described above, a resin composition containing almost no carboxylic acid radical is obtained. Therefore, in this drying step, the carboxylic acid is not volatilized and the carboxylic acid is released to the periphery. It is possible to provide a manufacturing method that takes into consideration the surrounding environment without having to do so.

  The EVOH resin composition (F) suitably used in the present invention contains an alkali metal salt (A) in an amount of 0.1 to 20 μmol / g in terms of alkali metal, and is extracted by immersing in 95 ° C. water for 10 hours. Containing 0 to 2 μmol / g of the carboxylate radical (C1) and 0 to 40 μmol / g of the carboxylate radical (C2) extracted by immersion in a 0.05 N aqueous sodium hydroxide solution at 95 ° C. for 10 hours. EVOH resin composition (F).

  The EVOH resin composition (F) is an EVOH resin composition (F) that hardly generates odor and is excellent in long-run property during melt molding. The EVOH resin composition (F) is preferably manufactured by the above-described manufacturing method, but is not limited to that manufactured by the method.

  The EVOH resin composition (F) contains the alkali metal salt (A) in an amount of 0.1 to 20 μmol / g in terms of alkali metal. By containing the alkali metal salt (A), the interlayer adhesion, the coloration resistance at the time of melting and the long run property of the resin composition comprising the EVOH resin composition (F) and the modified EVOH (G) are improved. When the content is less than 0.1 μmol / g, the interlayer adhesion, the coloration resistance at melting and the long run property are insufficient, and when it exceeds 20 μmol / g, the coloration resistance at melting becomes poor. In the range of 0.1 to 0.3 μmol / L, the coloration resistance and long run property at the time of melting are relatively good, but when used in a multilayer structure with other resins, the usual acid anhydride-modified adhesiveness The resin has insufficient adhesive strength. The lower limit of the content of the alkali metal salt (A) is more preferably 0.3 μmol / g or more, and more preferably 0.5 μmol / g or more. The upper limit of the content of the alkali metal salt (A) is preferably 15 μmol / g or less, more preferably 10 μmol / g or less, and particularly preferably 8 μmol / g or less.

At this time, it is preferable that the content of the alkali metal salt (A) and the ethylene content of EVOH satisfy the following formula (1).
0.95 × exp (0.039 × ET) −2 ≦ a ≦ 0.95 × exp (0.039 × ET) +2 (1)
here,
a is the content (μmol / g) of the alkali metal salt (A) in terms of alkali metal,
ET is the ethylene content of the ethylene-vinyl alcohol copolymer (mol%)
It is.

When there is more content of an alkali metal salt (A) than the range prescribed | regulated in the said (1) Formula, there exists a possibility that the hue of EVOH resin composition (F) may deteriorate. On the other hand, when it is less than the range specified in the above formula (1), the long run property and the adhesiveness may be deteriorated. It is more preferable to satisfy the following formula (1 ′), and it is more preferable to satisfy the following formula (1 ″).
0.95 × exp (0.039 × ET) −1.5 ≦ a ≦ 0.95 × exp (0.039 × ET) +1.5 (1 ')
0.95 × exp (0.039 × ET) −1 ≦ a ≦ 0.95 × exp (0.039 × ET) +1 (1 ")

  The EVOH resin composition (F) used in the present invention contains 0 to 2 μmol / g of carboxylic acid radical (C1) extracted by immersing in 95 ° C. water for 10 hours. Since it is assumed that most of the carboxylic acid and carboxylate contained in the EVOH resin composition (F) are extracted by immersing in water at 95 ° C. for 10 hours, the carboxylic acid group (C1) Is a numerical value almost corresponding to these total contents. That is, the EVOH resin composition (F) is a resin composition having a very low content of carboxylic acid and carboxylate. The content of the carboxylate group (C1) is preferably 1.5 μmol / g or less, more preferably 1 μmol / g or less, and further preferably 0.5 μmol / g or less.

  Further, the EVOH resin composition (F) used in the present invention contains 0 to 40 μmol / g of carboxylic acid radical (C2) extracted by immersion treatment in a 0.05 N aqueous sodium hydroxide solution at 95 ° C. for 10 hours. By immersing in an aqueous 0.05 N sodium hydroxide solution at 95 ° C. for 10 hours, not only most of the carboxylic acid and carboxylate contained in the EVOH resin composition (F) are extracted, In most of the unsaponified carboxylic acid ester groups remaining in the EVOH resin, the saponification reaction proceeds, and the carboxylic acid radical as the hydrolysis product is released and extracted. That is, the EVOH resin composition (F) is a resin composition having a small total content of carboxylic acid, carboxylate and carboxylic ester groups. The content of the carboxylate group (C2) is preferably 20 μmol / g or less, more preferably 10 μmol / g or less, further preferably 5 μmol / g or less, and optimally 2 μmol / g or less. .

  When the EVOH resin composition (F) is melt-kneaded, the temperature is usually 200 ° C. or higher, and many chemical reactions can proceed at that temperature. The carboxylic acid ester group contained in the EVOH resin may be hydrolyzed by reacting with water to liberate carboxylic acid, or may undergo transesterification with carboxylic acid or carboxylate. In addition, it is conceivable that carboxylic acid or carboxylate reacts with a hydroxyl group of EVOH to generate a carboxylic acid ester group or transesterifies with a carboxylic acid ester group. That is, in melt molding, particularly long-time melt molding, such a chemical reaction in the molten resin during heat melting cannot be ignored.

  The EVOH resin composition (F) pays attention to this point. With the total amount of carboxylic acid, carboxylate and carboxylic acid ester that can be converted to each other, the resin has improved melt stability and odor. It is intended to prevent the occurrence. The amount of carboxylic acid radical (C1) extracted by immersing in 95 ° C. water in a free form from the beginning for 10 hours is extremely small, including that which can be liberated under heating and melting conditions. When the amount of the carboxylic acid radical (C2) extracted by immersing in a 0.05 N aqueous sodium hydroxide solution for 10 hours is set to a certain value or less, a resin composition having an extremely long run property is obtained.

  Another EVOH resin composition (F) preferably used in the present invention contains an alkali metal salt (A) in an amount of 0.1 to 20 μmol / g in terms of alkali metal, and is immersed in water at 95 ° C. for 10 hours. The EVOH resin composition (F) contains 0 to 2 μmol / g of carboxylic acid radical (C1) extracted in this manner and has a saponification degree of 99.7 to 100 mol%.

  This is a resin composition similar to the EVOH resin composition (F) described above, but instead of the carboxylic acid group (C2) extracted by immersion in a 0.05 N aqueous sodium hydroxide solution at 95 ° C. for 10 hours. Further, the amount of unsaponified carboxylic acid ester group is expressed by the value of saponification degree. When EVOH has a saponification degree of 99.7 mol% or more, it has excellent long-run properties during melt molding. The saponification degree is more preferably 99.8 mol% or more, further preferably 99.9 mol% or more, and particularly preferably 99.95 mol% or more.

  It is preferable that the EVOH resin composition (F) used in the present invention further contains a boron compound (B) from the viewpoint that generation of the eyes on the die lip portion during melt molding can be suppressed. The effects and types of the boron compound (B) are as described in the description of the method for producing the EVOH resin composition (F). The content of the boron compound (B) is preferably 1 to 200 μmol / g in terms of boron element. It is more preferably 2 μmol / g or more, and further preferably 3 μmol / g or more. Moreover, it is more preferable that it is 150 micromol / g or less, and it is further more preferable that it is 100 micromol / g or less.

  In addition, the EVOH resin composition (F) containing the phosphoric acid compound (D) balances long run properties during melt molding, color resistance, particularly color resistance during high temperature molding, and interlayer adhesion. It is preferable in taking. The effects and types of the phosphoric acid compound (D) are as described in the description of the method for producing the EVOH resin composition (F). The upper limit of the content of the phosphoric acid compound (D) is preferably 5 μmol / g, more preferably 4 μmol / g, more preferably 3 μmol / g, and most preferably 1 in terms of phosphate radical. .5 μmol / g. When there are too many phosphate radicals, there is a possibility that the long run property is lowered. On the other hand, the lower limit of the content of the phosphate compound (D) is preferably 0.05 μmol / g, more preferably 0.1 μmol / g, and even more preferably 0.15 μmol / g in terms of phosphate radical. g, optimally 0.2 μmol / g.

  At this time, the content (a: μmol / g) of the alkali metal salt (A) in terms of alkali metal in the EVOH resin composition (F) and the content of the phosphate compound (D) in terms of phosphate radical The ratio (a / d) to (d: μmol / g) is preferably 2.4-50. By doing so, a resin composition having a good hue and long run property can be obtained. When the ratio (a / d) is less than 2.4, the long run property may be deteriorated. On the other hand, when the ratio (a / d) exceeds 50, the hue may be deteriorated, and the long run property may be adversely affected. The ratio (a / d) is more preferably 40 or less, and even more preferably 30 or less.

  These EVOH resin compositions (F) may contain an alkaline earth metal salt (E). The effects and types of the alkaline earth metal salt (E) are as described in the description of the method for producing the EVOH resin composition (F). The content of the alkaline earth metal salt (E) is preferably 0 to 10 μmol / g in terms of alkaline earth metal. It is more preferably 5 μmol / g or less, and further preferably 3 μmol / g or less. In particular, when emphasizing the suppression of coloring during melt molding, the content of the alkaline earth metal salt (E) is more preferably 2 μmol / g or less, and further preferably 1 μmol / g or less. It is preferable that it is not substantially contained.

  A suitable melt flow rate (MFR) of the EVOH resin composition (F) used in the present invention (measured at 190 ° C. under a load of 2160 g; provided that the melting point is around 190 ° C. or exceeds 190 ° C. under a load of 2160 g, Measured at a plurality of temperatures equal to or higher than the melting point, and a semi-logarithmic graph in which the reciprocal absolute temperature is plotted on the horizontal axis and the melt flow rate is plotted on the vertical axis (logarithm), the value extrapolated to 190 ° C. ~ 200 g / 10 min. It is. The lower limit of MFR is more preferably 0.2 g / 10 min. More preferably, 0.5 g / 10 min. Above, optimally 1 g / 10 min. That's it. Further, the upper limit of MFR is more preferably 50 g / 10 min. Or more preferably 30 g / 10 min. And optimally 15 g / 10 min. It is as follows. When the melt flow rate is smaller than this range, the inside of the extruder is in a high torque state during molding, making it difficult to melt and knead with the modified EVOH (G), and when larger than the range, the EVOH resin The molded product formed by molding the resin composition comprising the composition (F) and the modified EVOH (G) is not preferable because of insufficient mechanical strength.

  When the EVOH resin composition (F) contains the phosphoric acid compound (D), the molded product obtained when the EVOH resin composition (F) is melt-molded contains the content of the phosphoric acid compound (D) in terms of phosphate radicals ( d: μmol / g) and phosphorus element content (t: μmol / g) ratio (d / t) is 0.4 or less and substantially free of organophosphorus compounds extractable with chloroform It is preferable.

  Here, content (d) of a phosphoric acid compound (D) is a value calculated | required from the quantity of the phosphoric acid radical extracted, for example by immersing a melt-molded article in aqueous solution. That is, it indicates the amount of the phosphoric acid compound (D) that is contained in the melt-molded product as phosphoric acid or a salt thereof and can be extracted with an aqueous solution. On the other hand, the phosphorus element content (t) is, for example, a value obtained by performing an emission analysis on the amount of phosphorus element contained in an aqueous solution in which ash obtained by completely burning a melt-formed product is dissolved. That is, not only what is extracted by an extraction operation in an aqueous solution but also the total phosphorus element contained in the melt-formed product is quantified. Therefore, the ratio (d / t) being 0.4 or less means that more than half of the total phosphorus elements contained in the melt-molded product are contained in an unextractable form.

  Conventionally, in the case where the phosphoric acid compound (D) is contained in EVOH, almost the entire amount of the phosphoric acid compound (D) contained in the EVOH resin composition can be extracted. It was possible to extract the phosphate compound (D). Therefore, the ratio (d / t) was close to 1 even after melt molding. On the other hand, most of the EVOH resin composition (F) used in the present invention can be extracted as long as the EVOH resin composition (F) is simply immersed in an aqueous solution to contain the phosphate compound (D) and dried. Nevertheless, extraction is impossible by heating in the molten state. Even when the temperature is lower than the melting point, the ratio (d / t) tends to decrease when heated for a long time at a relatively high temperature. Therefore, a reduction in the ratio (d / t) may be observed not only in a melt-molded product but also in a pellet that has been heat-dried for a long time.

  Although it is not always clear what chemical structure the phosphorus element contained in the melt-molded product exists, the phosphate compound (D) reacts with the hydroxyl group of EVOH to form a phosphate ester. It is estimated that Thus, it is estimated that extraction is impossible by being fixed to the molecular chain of EVOH. This time, it is thought that unprecedented characteristics were obtained by adopting an unprecedented manufacturing method such as immersing in an aqueous solution containing carbon dioxide gas instead of using carboxylic acids such as acetic acid. However, the method for producing a melt-formed product having a ratio (d / t) of 0.4 or less is not particularly limited.

  The melt-formed product having a ratio (d / t) of 0.4 or less thus obtained is excellent in long run properties. It is also conceivable that the phosphorus element presumed to be fixed to the EVOH molecular chain contributes to thermal stability. The ratio (d / t) is preferably 0.35 or less, more preferably 0.3 or less, even more preferably 0.25 or less, and optimally 0.2 or less.

  The suitable range of phosphorus element content (t) at this time is the same as the suitable range of content of the phosphoric acid compound (D) in the above-mentioned EVOH resin composition (F). This is because the phosphorus element content (t) does not substantially change before and after melting and heating. It is preferably 5 μmol / g, more preferably 4 μmol / g, even more preferably 3 μmol / g, and most preferably 1.5 μmol / g. On the other hand, the lower limit of the phosphorus element content (t) is preferably 0.05 μmol / g, more preferably 0.1 μmol / g, and even more preferably 0.15 μmol / g. Is 0.2 μmol / g.

  In some applications, the EVOH resin composition (F) may contain an organic phosphorus compound such as an antioxidant. In such a case, if the ratio (d / t) is 0.4 or less, it contains a substantial amount of a phosphorus compound that is not fixed to the EVOH molecular chain but cannot be extracted into water. However, it is not always excellent in long run performance. Therefore, in order to distinguish from such a resin composition, it is preferable that the melt-molded product does not substantially contain an organophosphorus compound that can be extracted with chloroform. Here, “not containing substantially” means, for example, less than 0.01 μmol / g.

  Moreover, about the kind and content of the alkali metal salt (A), the boron compound (B), the carboxylate radical (C1, C2), and the alkaline earth metal salt (E) in the melt-molded product, the EVOH resin composition described above is used. It is the same as the case of. The same applies to the type of EVOH used, the relationship between the content of alkali metal salt (A) and the ethylene content of EVOH, and the like. None of these values change substantially before and after melt molding.

  The resin composition of the present invention has an ethylene content of 5 to 55 containing 1 to 99% by weight of the EVOH resin composition (F) as described above and 0.3 to 40 mol% of the following structural unit (I). It is a resin composition composed of 1 to 99% by weight of a modified EVOH (G) of mol%. By blending the EVOH resin composition (F) and the modified EVOH (G), the flexibility and secondary processability of the EVOH resin composition (F) can be improved while suppressing a decrease in barrier properties and transparency. it can.

(Wherein R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms (such as an alkyl group or an alkenyl group) . R ¹ , R ² , R ³ And R ⁴ may be the same group or different .

In a preferred embodiment, both R ¹ and R ² are hydrogen atoms. In a more preferred embodiment, both R ¹ and R ² are hydrogen atoms, one of R ³ and R ⁴ is an aliphatic hydrocarbon group having 1 to 10 carbon atoms, and the other is hydrogen. Is an atom. Preferably, the aliphatic hydrocarbon group is an alkyl group or an alkenyl group. From the viewpoint of particularly emphasizing gas barrier properties when using modified EVOH (G) as a barrier material, one of R ³ and R ⁴ is a methyl group or an ethyl group, and the other is a hydrogen atom. More preferred.

  The amount of the structural unit (I) contained in the modified EVOH (G) needs to be in the range of 0.3 to 40 mol%. The lower limit of the amount of the structural unit (I) is preferably 0.5 mol% or more, more preferably 1 mol% or more, and further preferably 2 mol% or more. On the other hand, the upper limit of the amount of the structural unit (I) is preferably 35 mol% or less, more preferably 30 mol% or less, and further preferably 25 mol% or less. When the amount of the structural unit (I) contained is within the above range, a modified EVOH (G) having gas barrier properties, stretchability, flexibility and bending resistance can be obtained.

  The ethylene content of the modified EVOH (G) is preferably 5 to 55 mol%. From the viewpoint that the modified EVOH (G) obtains good stretchability, flexibility and bending resistance, the lower limit of the ethylene content of the modified EVOH (G) is more preferably 10 mol% or more, and even more preferably. Is 20 mol% or more, particularly preferably 25 mol% or more, and further preferably 31 mol% or more. On the other hand, from the viewpoint of gas barrier properties of the modified EVOH (G), the upper limit of the ethylene content of the modified EVOH (G) is more preferably 50 mol% or less, and even more preferably 45 mol% or less. When the ethylene content is less than 5 mol%, the melt moldability may be deteriorated, and when it exceeds 55 mol%, the gas barrier property may be insufficient.

  The constituent components other than the structural unit (I) and the ethylene unit constituting the modified EVOH (G) are mainly vinyl alcohol units. This vinyl alcohol unit is usually a vinyl alcohol unit that has not reacted with a monovalent epoxy compound among vinyl alcohol units contained in the raw material EVOH. Further, unsaponified vinyl acetate units that may be contained in the raw EVOH are usually contained in the modified EVOH (G) as they are. It was found from the measurement results of NMR and the melting point that the modified EVOH (G) is a random copolymer containing these components. Furthermore, other components can be included within the range not impairing the object of the present invention.

  A suitable melt flow rate (MFR) (under 190 ° C. and 2160 g load) of the modified EVOH (G) is 0.1 to 30 g / 10 minutes, more preferably 0.3 to 25 g / 10 minutes, and even more preferably. Is 0.5 to 20 g / 10 min. However, those having a melting point near 190 ° C. or exceeding 190 ° C. were measured under a load of 2160 g and at a plurality of temperatures higher than the melting point. The value is extrapolated to 190 ° C.

  The method for producing the modified EVOH (G) is not particularly limited. The method recommended by the present inventors is a method for obtaining modified EVOH (G) by reacting EVOH as a raw material with a monovalent epoxy compound having a molecular weight of 500 or less.

  As the EVOH used as a raw material for the modified EVOH (G) in the present invention, the same EVOH used as a raw material for the EVOH resin composition (F) described above can be used. At this time, at least one selected from the group consisting of an alkali metal salt (A), a boron compound (B), a carboxylic acid or a salt thereof (C), a phosphoric acid compound (D) or an alkaline earth metal salt (E) is appropriately used. The contained EVOH resin composition may be used as a raw material. The suitable content of these additives at this time is the same as the suitable content in the aforementioned EVOH resin composition (F).

  It is essential that the monovalent epoxy compound having a molecular weight of 500 or less used when producing the modified EVOH (G) in the present invention is a monovalent epoxy compound. That is, it must be an epoxy compound having only one epoxy group in the molecule. When a divalent or higher polyvalent epoxy compound is used, the effects of the present invention cannot be achieved. However, in the production process of the monovalent epoxy compound, the polyvalent epoxy compound may be contained in a very small amount. A monovalent epoxy compound containing a very small amount of a polyvalent epoxy compound can be used as the monovalent epoxy compound having a molecular weight of 500 or less in the present invention as long as the effect of the present invention is not impaired.

As the monovalent epoxy compound having a molecular weight of 500 or less used in the present invention , specifically, a compound represented by the following formula (III) is used .

(In the formula, R ⁵ and R ⁶ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms (such as an alkyl group or an alkenyl group) . )

Among these monovalent epoxy compounds having a molecular weight of 500 or less, the monovalent epoxy compound used in the present invention is particularly preferably an epoxy compound having 2 to 8 carbon atoms. From the viewpoint of easy handling of the compound and reactivity with EVOH during production, the carbon number of the monovalent epoxy compound is preferably 2 to 6, and more preferably 2 to 4 . Reactivity with EVOH, and from the gas barrier properties of the viewpoint of the resulting modified EVOH (G), 1,2-epoxybutane, 2,3-epoxybutane, particularly preferably epoxypropane and epoxy ethane, among them epoxypropane preferable. In applications requiring sanitary properties such as food packaging applications, beverage packaging applications, and pharmaceutical packaging applications, 1,2-epoxybutane, 2,3-epoxybutane, epoxypropane, and epoxyethane should be used as monovalent epoxy compounds. It is preferable to use epoxypropane.

  The modified EVOH (G) is obtained by reacting the raw material EVOH with the monovalent epoxy compound. The suitable mixing ratio of EVOH and the monovalent epoxy compound at this time is 1 to 50 parts by weight of the monovalent epoxy compound with respect to 100 parts by weight of EVOH, and more preferably the monovalent epoxy compound 2 with respect to 100 parts by weight of EVOH. It is -40 weight part, Especially preferably, it is 5-35 weight part of monohydric epoxy compounds with respect to 100 weight part of EVOH.

  A method for producing modified EVOH (G) by reacting raw material EVOH with a monovalent epoxy compound having a molecular weight of 500 or less is not particularly limited, and a production method in which EVOH and a monovalent epoxy compound are reacted in a solution, and A suitable method is a production method in which EVOH and a monovalent epoxy compound are reacted in an extruder. Of these, a production method in which EVOH and a monovalent epoxy compound are reacted by melting and kneading in an extruder is preferable. It is also preferable to use a catalyst containing ions of metals belonging to Groups 3 to 12 of the periodic table when they are reacted by melt-kneading. The details of the method for producing the modified EVOH (G) used in the present invention are as described in WO 02/092643 pamphlet.

  The modified EVOH (G) is selected from the group consisting of alkali metal salts (A), boron compounds (B), carboxylic acids or salts thereof (C), phosphoric acid compounds (D), or alkaline earth metal salts (E). At least one of the above can be added after the modified EVOH (G) is obtained by the reaction of EVOH with a monovalent epoxy compound.

  The combination of the respective ethylene contents of the modified EVOH (G) and the EVOH resin composition (F) is adjusted according to the use and purpose of the resin composition. For example, the difference between the ethylene content of the modified EVOH (G) and the ethylene content of the EVOH resin composition (F) is preferably 2 to 30 mol%. The difference is more preferably 5 mol% or more and 20 mol% or less.

  Thus, when there is a difference in the ethylene content of both the modified EVOH (G) and the EVOH resin composition (F), the ethylene content of the modified EVOH (G) is the ethylene content of the EVOH resin composition (F). When it is larger than the amount, the modified EVOH (G) having extremely excellent flexibility can be blended therein while maintaining the characteristics of the EVOH resin composition (F) having a good gas barrier property. As a result, it is possible to provide a resin composition that is excellent in secondary processability such as thermoformability and stretchability, flexibility and flex resistance, and also excellent in gas barrier properties. This embodiment is one particularly useful embodiment. Conversely, it may be preferable that the ethylene content of the modified EVOH (G) is smaller than the ethylene content of the EVOH resin composition (F). In this case, the melting points of both are close to each other, which is advantageous when molding at a low temperature.

  On the other hand, it may be preferable that the difference in ethylene content between the modified EVOH (G) and the EVOH resin composition (F) is small, and in that case, the difference is preferably 2 mol% or less. is there. At this time, it is more preferable to use modified EVOH (G) and EVOH resin composition (F) having substantially the same ethylene content. Thus, by reducing the difference in ethylene content between the modified EVOH (G) and the EVOH resin composition (F), the flexibility, secondary workability, fatigue resistance or interlayer adhesion is improved. In addition, it is possible to obtain a resin composition particularly excellent in barrier properties and transparency.

  The resin composition of the present invention comprises 1 to 99% by weight of EVOH resin composition (F) and 1 to 99% by weight of modified EVOH (G). At this time, it is preferable that the said resin composition consists of EVOH resin composition (F) 50-99 weight% and modified | denatured EVOH (G) 1-50 weight%. That is, it is preferable that the unmodified EVOH resin composition (F) is a main component and the modified EVOH (G) is a subordinate component. By carrying out like this, a softness | flexibility and secondary workability can be provided to a resin composition, without impairing the gas barrier property which EVOH resin composition (F) originally has. Further, the modified EVOH (G) is economically advantageous because the production cost is higher than that of the unmodified EVOH resin composition (F). The content of the modified EVOH (G) is more preferably 5% by weight or more, and further preferably 10% by weight or more. At this time, the more preferable content of the EVOH resin composition (F) is 95% by weight or less, and more preferably 90% by weight or less. On the other hand, the content of the modified EVOH (G) is more preferably 40% by weight or less, and further preferably 30% by weight or less. At this time, the more preferable content of the EVOH resin composition (F) is 60% by weight or more, and more preferably 70% by weight or more.

  The resin composition of the present invention includes an antioxidant, a colorant, an ultraviolet absorber, a slip agent, an antistatic agent, a plasticizer, a cross-linking agent such as boric acid, an inorganic substance, and the like within a range that does not impair the effects exhibited by the present invention. You may mix | blend various resins, such as various additives, such as a filler and an inorganic desiccant, and a super absorbent polymer.

  As a blending means for melt-kneading the EVOH resin composition (F) and the modified EVOH (G) to obtain the resin composition of the present invention, a ribbon blender, a high-speed mixer kneader, a pelletizer, a mixing roll, an extruder, intensive A mixer etc. are illustrated. Among these, the melt kneading method using a single-screw or twin-screw extruder (same direction or different direction), an intensive mixer, a continuous intensive mixer and the like is preferable from the viewpoint of process simplicity and cost. The kneading temperature is appropriately selected depending on the properties of the equipment, the molecular weight of the resin, the blending ratio and the like, but in many cases, the range of 150 to 300 ° C. is preferable. In order to prevent oxidation of the resulting resin composition, it is preferable that the hopper port be sealed with nitrogen and extruded at a low temperature. The longer the kneading time, the better results can be obtained, but 0.1 to 20 minutes is preferable from the viewpoint of preventing oxidation of the resin composition and production efficiency.

  The resin composition of the present invention thus obtained is molded into various molded products such as films, sheets, containers, pipes and fibers by melt molding. As the melt molding method, extrusion molding, inflation extrusion, blow molding, injection molding, melt spinning and the like are possible. The melting temperature varies depending on the melting point of the copolymer, but is preferably about 150 to 270 ° C. At this time, the resin composition of the present invention may be once pelletized and then subjected to molding, or the EVOH resin composition (F) and the modified EVOH (G) may be dry blended and directly subjected to molding. . These molded products can be pulverized and molded again for reuse. Moreover, it is also possible to perform secondary processing by uniaxially or biaxially stretching a film, sheet, fiber or the like, or thermoforming.

  The resin composition of the present invention can be used as a molded product composed of only a single layer of the resin composition. However, since it has excellent interlayer adhesion, a multilayer structure comprising at least one layer of the resin composition. It is also suitable. The layer structure of the multilayer structure is represented by X / T, T / X / T, X / Ad / T, T, where X is the resin composition of the present invention, Ad is the adhesive resin, and T is the thermoplastic resin. Although / Ad / X / Ad / T etc. are mentioned, it is not limited to this. Each of the layers shown here may be a single layer or may be a multilayer according to circumstances.

  The method for producing the multilayer structure shown above is not particularly limited. For example, a method of melt-extruding a thermoplastic resin on a molded article (film, sheet, etc.) comprising the resin composition of the present invention, and conversely, the resin composition and another thermoplastic resin on a substrate such as a thermoplastic resin And a method of co-extrusion or co-injection of a thermoplastic resin and the resin composition of the present invention, and a molded product obtained from the resin composition of the present invention and films and sheets of other substrates And a method of laminating using a known adhesive such as an organic titanium compound, an isocyanate compound, and a polyester compound. Among these, the method of co-extrusion or co-injection is preferable.

  The method of coextrusion molding of the resin composition of the present invention and the thermoplastic resin is not particularly limited, and a multi-manifold merging method T-die method, a feed block merging method T-die method, an inflation method and the like are exemplified as suitable ones. . Further, the method of co-injection molding is not particularly limited, and a general method can be used.

  The thermoplastic resin used for laminating with the resin composition of the present invention includes linear low density polyethylene, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer. Polymers, polypropylene, propylene-α-olefin copolymers (α-olefins having 4 to 20 carbon atoms), olefins such as polybutene and polypentene alone or copolymers thereof, polyesters such as polyethylene terephthalate, polyester elastomers, nylon- 6, Polyamide resin such as nylon-6, 6, polystyrene, polyvinyl chloride, polyvinylidene chloride, acrylic resin, vinyl ester resin, polyurethane elastomer, polycarbonate, chlorinated polyethylene, chlorinated polypropylene, and the like.

  When laminating the resin composition of the present invention and the thermoplastic resin, the adhesive resin in the case of using the adhesive resin is preferably an adhesive resin made of a carboxylic acid-modified polyolefin. Here, the carboxylic acid-modified polyolefin is a modified olefinic polymer containing a carboxyl group obtained by chemically (for example, by addition reaction or graft reaction) bonding an ethylenically unsaturated carboxylic acid or its anhydride to an olefin polymer. Refers to coalescence. In addition, the olefin polymer is a polyolefin such as polyethylene (low pressure, medium pressure, high pressure), linear low density polyethylene, polypropylene, boribten, or the like, a comonomer (vinyl ester, non-polymer) capable of copolymerizing the olefin and the olefin. Means a copolymer with a saturated carboxylic acid ester and the like, for example, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ethyl ester copolymer, and the like. Of these, linear low density polyethylene, ethylene-vinyl acetate copolymer (vinyl acetate content 5-55 wt%), ethylene-acrylic acid ethyl ester copolymer (acrylic acid ethyl ester content 8-35 wt. %), Linear low density polyethylene and ethylene-vinyl acetate copolymers are particularly preferred. Examples of the ethylenically unsaturated carboxylic acid or its anhydride include ethylenically unsaturated monocarboxylic acid, its ester, ethylenically unsaturated dicarboxylic acid, its mono or diester, and its anhydride. Among these, ethylenically unsaturated dicarboxylic acid Anhydrides are preferred. Specific examples include maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, maleic acid monomethyl ester, maleic acid monoethyl ester, maleic acid diethyl ester, and fumaric acid monomethyl ester. Acid is preferred.

  The multilayer structure obtained as described above can be used as it is, and can be used as a packaging film, a container, or the like, but various molded products can be obtained by further secondary processing. Examples of the secondary processing method include a method of stretching a film or sheet in a uniaxial or biaxial direction, a method of thermoforming, a method of rolling, and the like. Moreover, the co-injection-molded parison can be blow-molded. Especially, since the multilayer structure which has the resin composition layer of this invention is excellent in thermoformability, it is used suitably as a thermoformed film or a thermoformed sheet.

  Such a molded article has a good appearance, suppresses the generation of odor, and has excellent interlayer adhesion, and is therefore suitable for various food packaging containers such as packaging films, deep-drawn containers, cup-shaped containers, and bottles. Used for. In addition to food packaging containers, they are also used for applications such as fuel containers, fuel pipes, hot water circulation pipes for floor heating, and wallpaper.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this Example. Hereinafter, “%” and “parts” are based on weight unless otherwise specified. In addition, all the water used ion-exchange water.

(1) Determination of alkali metal salt (A) The pellets of the dried EVOH resin composition (F) were pulverized by freeze pulverization. The obtained pulverized EVOH resin composition (F) was sieved with a sieve having a nominal size of 1 mm (standard fluid standard JIS Z-8801 compliant). 10 g of the EVOH resin composition (F) powder that has passed through the above sieve and 50 mL of 0.01 N hydrochloric acid aqueous solution are put into a conical flask with a 100 mL stopper, attached with a cooling condenser, stirred at 95 ° C. for 10 hours, and heated to extract did. 2 mL of the obtained extract was diluted with 8 mL of ion exchange water. The diluted extract was quantitatively analyzed using an ion chromatography IC7000 manufactured by Yokogawa Electric Corporation to determine the amounts of Na and K ions. In the determination, calibration curves prepared using a sodium chloride aqueous solution and a potassium chloride aqueous solution were used. From the amount of Na and K ions thus obtained, the amount of alkali metal salt (A) contained in the dried EVOH pellets was obtained in terms of metal element.
Ion chromatography measurement conditions:
Column: ICS-C25 manufactured by Yokogawa Electric Corporation
Eluent: aqueous solution containing 5.0 mM tartaric acid and 1.0 mM 2,6-pyridinedicarboxylic acid Measurement temperature: 40 ° C.
Eluent flow rate: 1 mL / min.
Sample injection amount: 50 μL

(2) Quantification of Carboxylic Acid Root (C1) Extracted by Dipping Treatment in Water at 95 ° C. for 10 Hours Pellets of the dried EVOH resin composition (F) were pulverized by freeze pulverization. The obtained pulverized EVOH resin composition (F) was sieved with a sieve having a nominal size of 1 mm (standard fluid standard JIS Z-8801 compliant). 10 g of EVOH resin composition (F) powder and 50 mL of ion-exchanged water that passed through the above sieve were put into a 100 mL Erlenmeyer flask with a stopper, attached with a cooling condenser, and stirred and extracted at 95 ° C. for 10 hours. 2 mL of the obtained extract was diluted with 8 mL of ion exchange water. The diluted extract was quantitatively analyzed using an ion chromatography IC7000 manufactured by Yokogawa Electric Corporation, and the amount of carboxylic acid (acetic acid) ions was quantified to obtain a carboxylic acid radical (C1). Note that a calibration curve prepared using an aqueous acetic acid solution was used for quantification.
Ion chromatography measurement conditions:
Column: SCS5-252 manufactured by Yokogawa Electric Corporation
Eluent: 0.1% phosphoric acid aqueous solution Measurement temperature: 40 ° C
Eluent flow rate: 1 mL / min.
Sample injection amount: 50 μL

(3) Quantification of Carboxylic Acid Root (C2) Extracted by Dipping Treatment in 0.05 N Aqueous Sodium Hydroxide at 95 ° C. for 10 Hours Pellets of the dry EVOH resin composition (F) were pulverized by freeze pulverization. The obtained pulverized EVOH resin composition (F) was sieved with a sieve having a nominal size of 1 mm (standard fluid standard JIS Z-8801 compliant). 10 g of the EVOH resin composition (F) powder that has passed through the above sieve and 50 mL of 0.05 N aqueous sodium hydroxide solution are put into a 100 mL Erlenmeyer flask with a stopper, attached with a cooling condenser, and stirred at 95 ° C. for 10 hours. Extracted with heating. 7 mL of ion-exchanged water was added to 2 mL of the obtained extract to dilute, and 1 mL of 0.1 N phosphoric acid aqueous solution was further added to prepare a sample solution for analysis. The amount of the carboxylate ion contained in the diluted extract is quantitatively analyzed using an ion chromatography IC7000 manufactured by Yokogawa Electric Corporation, the amount of the carboxylate (acetate) ion is quantified, and the carboxylate group ( C2) was obtained. In addition, for the determination, 7 mL of ion-exchanged water was added to 2 mL of a solution obtained by diluting acetic acid with 0.05 N aqueous sodium hydroxide, and 1 mL of 0.1 N aqueous phosphoric acid was added. A standard curve was used.
Ion chromatography measurement conditions:
Column: SCS5-252 manufactured by Yokogawa Electric Corporation
Eluent: 0.1% phosphoric acid aqueous solution Measurement temperature: 40 ° C
Eluent flow rate: 1 mL / min.
Sample injection amount: 50 μL

(4) Quantitative determination of boron compound (B) 50 mg of pellets of the dry EVOH resin composition (F) were completely burned by an oxygen flask combustion method, and the obtained combustion ash was dissolved in 10 mL of a 1 mol / L nitric acid aqueous solution. Using the solution, the content of the boron compound (B) was obtained in terms of boron element by high-frequency plasma emission analysis (ICP emission analyzer IRIS AP manufactured by Jarrel Ash).

(5) Quantification of content (d) of phosphoric acid compound (D) In this example, the content (d1) of the phosphoric acid compound (D) in the pellets before melt molding and the single-layer film after melt molding The content (d2) of the phosphoric acid compound (D) was measured.

  When measuring the EVOH resin composition (F) pellets before melt molding, the pellets of the dry EVOH resin composition (F) were first pulverized by freeze pulverization. The obtained pulverized EVOH resin composition (F) was sieved with a sieve having a nominal size of 1 mm (standard fluid standard JIS Z-8801 compliant). 10 g of EVOH resin composition (F) powder and 50 mL of 0.01 N hydrochloric acid aqueous solution which passed through the above sieve were put into a 100 mL conical flask with a stopper, attached with a cooling condenser, and stirred and extracted at 95 ° C. for 4 hours. The obtained extract was quantitatively analyzed using an ion chromatography IC7000 manufactured by Yokogawa Electric Corporation, and the amount of phosphate ions was quantified to obtain a phosphate radical amount (d1: μmol / g). For the determination, a calibration curve prepared using an aqueous sodium dihydrogen phosphate solution was used.

  When measuring a single-layer film after melt molding, measurement was performed in the same manner as a pellet-shaped sample, except that 5 g obtained by cutting the film into a strip shape was used instead of 10 g of the EVOH resin composition (F) powder. Then, the amount of phosphate ion was quantified to obtain the amount of phosphate radical (d2: μmol / g).

Ion chromatography measurement conditions:
Column: ICS-A23 manufactured by Yokogawa Electric Corporation
Eluent: Aqueous solution containing 2.5 mM sodium carbonate and 1.0 mM sodium bicarbonate Measurement temperature: 40 ° C
Sample injection amount: 50 μL

(6) Phosphorus element content (t)
100 mg of the monolayer film after melt molding was completely burned by an oxygen flask combustion method, and the obtained combustion ash was dissolved in 10 mL of a 1 mol / L nitric acid aqueous solution. Using this solution, a phosphorus element content (t: μmol / g) was obtained by high-frequency plasma emission analysis (ICP emission analyzer “IRIS AP” manufactured by Jarrel Ash).

(7) Content of organophosphorus compound extractable with chloroform 100 g of a melt-molded monolayer film crushed to a size of 5 mm square or less is filled into a cylindrical filter paper, and 3000 ml of chloroform is put into a flask. Then, extraction was performed for 48 hours under reflux conditions using a Soxhlet-type extraction apparatus. Chloroform was removed from the extract with a rotary evaporator to obtain a residue. The obtained residue was completely burned by an oxygen flask combustion method, and the obtained combustion ash was dissolved in 10 mL of 1 mol / L nitric acid aqueous solution. Using this solution, a phosphorus element content was obtained by high-frequency plasma emission analysis (ICP emission analysis device “IRIS AP” manufactured by Jarrel Ash).

(8) Measurement of saponification degree (NMR method)
Dry EVOH pellets were ground by freeze grinding. The obtained pulverized EVOH was sieved with a sieve having a nominal size of 1 mm (conforming to standard sieve standard JIS Z-8801). 5 g of EVOH powder that passed through the above sieve was immersed in 100 g of ion-exchanged water, stirred at 85 ° C. for 4 hours, then drained and dried twice. Using the obtained powder EVOH after washing, NMR was measured under the following measurement conditions, and the degree of saponification was determined by the following analysis method.

Measurement conditions: Device name: JEOL Superconducting Nuclear Magnetic Resonance Device Lambda 500
Observation frequency: 500 MHz
Solvent: DMSO-d6
Polymer concentration: 4% by weight
Measurement temperature: 40 ° C and 95 ° C
Number of integrations: 600 times Pulse delay time: 3.836 seconds Sample rotation speed: 10-12 Hz
Pulse width (90 ° pulse): 6.75 μsec

・ Analysis method In the measurement at 40 ° C., a hydrogen peak in the water molecule is observed around 3.3 ppm, and the methine hydrogen peak of the vinyl alcohol unit of EVOH has a portion of 3.1 to 3.7 ppm. It overlapped. On the other hand, in the measurement at 95 ° C., the overlap generated at 40 ° C. is eliminated, but the hydrogen peak of the hydroxyl group of the vinyl alcohol unit of EVOH present in the vicinity of 4 to 4.5 ppm is methine of the vinyl alcohol unit of EVOH. It overlapped with a portion of 3.7 to 4 ppm of the hydrogen peak. That is, for the quantification of EVOH vinyl alcohol unit methine hydrogen (3.1-4 ppm), in order to avoid overlap with the hydrogen peak of water or hydroxyl group, about 3.1-3.7 ppm portion, The measurement data of ° C. was adopted, the measurement data of 40 ° C. was adopted for the portion of 3.7 to 4 ppm, and the total amount of the methine hydrogen was quantified as the total value thereof. It is known that the hydrogen peak of water or hydroxyl shifts to the high magnetic field side by increasing the measurement temperature.

Therefore, it analyzed using the measurement result of both 40 degreeC and 95 degreeC as follows. From the spectrum measured at 40 ° C., the integrated value (I ₁ ) of the peak of chemical shift of 3.7 to 4 ppm and the integrated value (I ₂ ) of the peak of chemical shift of 0.6 to 1.8 ppm are obtained. On the other hand, from the spectrum measured at 95 ° C., the integrated value (I ₃ ) of the peak of chemical shift of 3.1 to 3.7 ppm, the integrated value (I ₄ ) of the peak of chemical shift of 0.6 to 1.8 ppm and The integrated value (I ₅ ) of the peak of chemical shift of 1.9 to 2.1 ppm is determined. Here, the peak of chemical shift of 0.6 to 1.8 ppm is mainly derived from methylene hydrogen, and the peak of chemical shift of 1.9 to 2.1 ppm is in unsaponified vinyl acetate units. It is derived from methyl hydrogen. The saponification degree was calculated from these integral values by the following formula.

(9) Intrinsic Viscosity 0.20 g of dry EVOH pellets to be used as a sample is precisely weighed and dissolved in 40 mL of hydrous phenol (water / phenol = 15/85 wt%) at 60 ° C. for 4 hours. Then, the viscosity was measured with an Ostwald viscometer (t0 = 90 seconds), and the intrinsic (extreme) viscosity [η] was determined by the following equation.
[Η] = (2 × (ηsp−lnηrel)) ^1/2 / C (L / g)
ηsp = t / t0-1 (specific viscosity)
ηrel = t / t0 (relative viscosity)
C: EVOH concentration (g / L)
T0: Time for blank (hydrous phenol) to pass through viscometer t: Time for hydrous phenol solution in which sample is dissolved to pass viscometer

(10) Measurement of moisture content of water-containing EVOH pellets Using a HR73 halogen moisture content analyzer manufactured by METLER, the moisture content of EVOH pellets was measured under the conditions of a drying temperature of 180 ° C, a drying time of 20 minutes, and a sample amount of about 10 g.

(11) Measurement of carbon dioxide concentration A carbon dioxide sensor (CE-2041) was connected to a portable ion / pH meter (IM-22P) manufactured by Toa Denpa Kogyo Co., Ltd., and the carbon dioxide concentration in the solution was measured.

(12) Single-layer film-forming test A pellet of the dried EVOH resin composition (F) was produced by a 20 mm extruder D2020 (D (mm) = 20, L / D = 20, compression ratio = 2.0) manufactured by Toyo Seiki Seisakusho Co., Ltd. , Screw: full flight) to form a single layer under the following conditions to obtain a single layer film.
Extrusion temperature: C1 / C2 / C3 / Die = 175/200/220/220 ° C.
Screw rotation speed: 40rpm
Discharge rate: 1.3 kg / hr
Take-up roll temperature: 80 ° C
Take-up roll speed: 3.1 m / min.
Film thickness: 20 μm

(12-a) Color resistance The single-layer film produced by the above method was wound around a paper tube, and the degree of color of the film end face was determined with the naked eye as follows.
Judgment: Standard A: No coloring B: Slightly yellow C: Yellowing

(12-b) 72 hr-long run property The film 72 hours after the start of monolayer film formation was sampled, and gel-like irregularities (those of about 100 μm or more that can be confirmed with the naked eye) in the film were counted.
The number of bumps was converted to the number per 1.0 m ² and judged as follows.
Determination: Standard A: Less than 20 B: 20 or more and less than 40 C: 40 or more and less than 60 D: 60 or more

(12-c) 120 hr-long-run property Films 120 hours after the start of monolayer film formation were sampled, and gel-like irregularities (those of about 100 μm or more that can be confirmed with the naked eye) in the film were counted.
The number of bumps was converted to the number per 1.0 m ² and judged as follows.
Determination: Standard A: Less than 20 B: 20 or more and less than 40 C: 40 or more and less than 60 D: 60 or more

(13) Evaluation of high-temperature coloring property 5 g of pellets of the dried EVOH resin composition (F) were heated and melted at 250 ° C. for 2 minutes using a heat compression press device to prepare a disk-shaped sample having a thickness of 2 mm, and the hue was visually determined as follows. It was evaluated as follows.
Judgment: Criteria A: Almost no coloration.
B: Slightly yellowed.
C: Yellowish.

(14) Odor test 10 g of dry EVOH resin composition (F) pellets and 10 mL of ion-exchanged water were placed in a 100 mL glass screw tube, sealed with a lid. Then, after putting in 90 degreeC safe vent dryer (dryer) and heat-extracting for 15 hours, it stood at room temperature for 30 minutes and cooled the said screw pipe | tube. After cooling, the lid of the screw tube was opened, and the odor of the resulting extract was evaluated as follows by using five monitors.
Judgment: Criteria A: No odor is felt.
B: A slight odor is felt.
C: Odor is felt.

(15) Adhesive strength test Pellet of dry EVOH resin composition (F), linear low density polyethylene (LLDPE; made by Mitsui Chemicals, Ultzex 2022L) and adhesive resin (Tie; made by SUMIKA. ATOCHEM Co. Ltd, Bondine TX8030 ) And a multilayer film of 3 types and 5 layers (LLDPE / Tie / EVOH / Tie / LLDPE = 50 μ / 10 μ / 10 μ / 10 μ / 50 μ) was obtained by the following method.
Extruder and T-die specifications used in this test are as follows.
Extruder:
EVOH 20φ Extruder Lab Model ME Type CO-EXT (Toyo Seiki)
25φ extruder for Tie P25-18AC (Osaka Seiki)
32φ extruder for LLDPE GF-32-A (Plastic Engineering Laboratory)
EVOH extrusion temperature:
C1 / C2 / C3 / die = 175/210/220/220 ° C.
Tie extrusion temperature:
C1 / C2 / C3 / die = 100/160/220/220 ° C.
LLDPE extrusion temperature:
C1 / C2 / C3 / die = 150/200/210/220 ° C.
T-die: 300mm width coat hanger die (Plastic Engineering Laboratory)

(15-a) Adhesive strength immediately after film formation Immediately after multilayer film formation, the obtained multilayer film was cut out to 150 mm in the MD direction and 10 mm in the TD direction, and immediately after that, by autograph (manufactured by Shimadzu Corporation, DCS-50M) T-type peel strength measurement was performed. In the measurement, the interlayer adhesive strength between Tie and EVOH on the cooling roll side of the multilayer film was measured.

(15-b) Adhesive strength after one week from film formation The above-prepared sample consisting of a multilayer film having a length of 150 mm and a width of 10 mm was left in a constant temperature and humidity chamber at 23 ° C.-50% RH for one week. Using the sample, T-type peel strength measurement was performed in a constant temperature and humidity chamber of 23 ° C.-50% RH by an autograph (manufactured by Shimadzu Corporation, DCS-50M). In the measurement, the interlayer adhesive strength between Tie and EVOH on the cooling roll side of the multilayer film was measured.

Example 1
[Production of EVOH Resin Composition (F)]
50 kg of a 45% methanol solution of ethylene-vinyl acetate copolymer having an ethylene content of 32 mol% and 129 kg of methanol were charged into a 470 L saponification reactor, and nitrogen gas was blown into the reactor while the internal temperature was set to 60 ° C. did. Thereto, 29 L (concentration: 80 g / L) of methanol solution of sodium hydroxide is added to start the saponification reaction. During the saponification reaction, methyl acetate generated as a by-product in the reaction system is continuously introduced into the reactor together with methanol in the reaction system in order to drive out the reaction system in order to increase the reaction efficiency. Nitrogen gas was continuously blown. The expelling speed was about 20 kg / hr in total of methyl acetate and methanol, and this was condensed and recovered using a cooling condenser. Two hours after the start of the reaction, 29 L of a methanol solution of sodium hydroxide (concentration: 80 g / L) was further added to drive the saponification reaction. Six hours after the start of the reaction, 6.8 kg of acetic acid and 56 L of water were added to neutralize the reaction solution to stop the reaction.

  The neutralized reaction solution was transferred from the reactor to a drum can and allowed to stand at room temperature for 16 hours to be cooled and solidified into a cake. Thereafter, the cake-like resin was drained using a centrifuge (manufactured by Kokusan Centrifuge Co., Ltd., H-130, rotation speed: 1200 rpm). Next, the step of decanting while continuously supplying ion-exchanged water from above to the center of the centrifuge and washing the resin with water was performed for 10 hours. The conductivity of the cleaning solution 10 hours after the start of cleaning was 30 μS / cm (measured with CM-30ET manufactured by Toa Denpa Kogyo).

  The granular EVOH thus obtained was dried at 60 ° C. for 48 hours using a dryer. 20 kg of dried granular EVOH was dissolved in 43 L of a water / methanol mixed solution (weight ratio: water / methanol = 4/6) at 80 ° C. for 12 hours with stirring. Next, the stirring was stopped and the temperature of the dissolution tank was lowered to 65 ° C. and left for 5 hours to degas the EVOH water / methanol solution. And it extrudes in a 5 degreeC water / methanol mixed solution (weight ratio: water / methanol = 9/1) from the metal plate which has a circular opening part with a diameter of 3.5 mm, precipitates in strand shape, and cuts. To obtain pellets having a diameter of about 4 mm and a length of about 5 mm.

  2.4 kg of the hydrous pellets thus obtained and 24 L of ion-exchanged water were placed in a plastic container having a height of 400 mm and an open diameter of 370 mm, washed with stirring at 25 ° C. for 2 hours, and then drained. Repeated twice. Next, an operation of adding 24 L of 1 g / L acetic acid aqueous solution to 2.4 kg of water-containing pellets, washing the mixture with stirring at 25 ° C. for 2 hours, and then removing the liquid was repeated twice. Further, 24 L of ion exchange water was added to 2.4 kg of the water-containing pellets, and the operation of washing with stirring at 25 ° C. for 2 hours and then draining was repeated 6 times. As a result of measuring the conductivity of the cleaning liquid after the sixth cleaning with CM-30ET manufactured by Toa Denpa Kogyo, the conductivity of the cleaning liquid was 3 μS / cm. The water content of the obtained EVOH pellets was 50% by weight.

  The thus-obtained EVOH after washing (ethylene content 32 mol%, saponification degree 99.98 mol% or more (calculated by NMR method), intrinsic viscosity 0.085 L / g) 2.4 kg hydrous pellets and concentration 0 A 36 g / L boric acid aqueous solution (5.1 L) was placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm, immersed at 25 ° C. for 10 hours, and drained after immersion.

  Next, 24L of ion-exchanged water was placed in a plastic container having a height of 400 mm and an open diameter of 370 mm. A silicon tube (inner diameter: 7 mm, outer diameter: 10 mm) was put into the ion-exchanged water in the container (using five of the above-mentioned silicon tubes), and 2 L, 5 L / min. Bubbling at a speed of carbon dioxide was blown. Carbon dioxide was supplied using a carbon dioxide cylinder (liquefied carbon dioxide 30 kg manufactured by Nippon Carbon Co., Ltd.) and a flow meter (Model RK-1600R manufactured by KOFLOC). 1.68 g of boric acid, 6.48 g of dipotassium monohydrogen phosphate, and 1.20 g of phosphoric acid are dissolved in the water into which the carbon dioxide gas is blown, and further, 5 L / min. Carbon dioxide was continuously blown at a speed of. The treatment liquid had a boric acid content of 0.07 g / L, a monopotassium monohydrogen phosphate content of 0.27 g / L, and a phosphoric acid content of 0.05 g / L. Moreover, when the pH of the said processing liquid after blowing in carbon dioxide gas for 1 hour was measured using the pH meter (Metler MA235), the pH of the said processing liquid was 4.9.

  Next, the blowing speed is 5 L / min. Then, 2.4 kg of the above water-containing pellets were added to the treatment liquid while blowing carbon dioxide gas, and immersed and stirred at 25 ° C. for 6 hours. Further, when the pH of the treatment liquid was measured every hour from the start of the treatment to the end of the treatment, the pH of the treatment liquid remained at 4.9 at any measurement and did not change. As a result of analyzing the carbon dioxide gas concentration in the treatment liquid, it was 20 mmol / L. After stirring for 6 hours by immersing in the treatment liquid, the obtained pellets were immediately drained, followed by hot-air drying at 80 ° C. for 3 hours and then at 107 ° C. for 24 hours to obtain a dried EVOH resin composition ( F) Pellets (water content 0.2% by weight) were obtained.

  The alkali metal salt (A) in the obtained dried EVOH resin composition (F) pellets was potassium, and the content of the alkali metal salt (A) was 3.40 μmol / g in terms of metal element. The content (d1) of the phosphate compound (D) was 1.2 μmol / g in terms of phosphate radical. The boron compound (B) content in the obtained dry EVOH resin composition (F) pellets was 143 ppm (13 μmol / g) in terms of boron element. Further, the amount of the carboxylate radical (C1) extracted by immersing the dry EVOH resin composition (F) pellets in 95 ° C. pure water for 10 hours is 0 ppm (0 μmol / g), and the 0.05 ° C. at 95 ° C. is 0.05. The amount of carboxylic acid (acetic acid) root (C2) extracted by immersing in a normal aqueous sodium hydroxide solution for 10 hours was 36 ppm (0.6 μmol / g). The MFR of the dried EVOH resin composition (F) pellet was 1.6 g / 10 min. (Under 190 ° C. and 2160 g load).

  Using the obtained dried EVOH resin composition (F) pellets, a single-layer film was prepared according to the above-described method, and a test for resistance to coloring and long run was performed. The evaluation results of the coloring resistance, 72-hour long run property, and 120-hour long run property of the EVOH resin composition (F) of this example were all judged as A. Moreover, content (d2) of the phosphoric acid compound (D) of a single layer film was 0.10 micromol / g in conversion of the phosphate radical, and phosphorus element content (t) was 1.2 micromol / g. The content of the organophosphorus compound that can be extracted with chloroform was less than 0.01 μmol / g.

  Using the obtained dried EVOH resin composition (F) pellets, a high-temperature colorability evaluation test was performed according to the above-described method. Moreover, when the odor test was done according to the above-mentioned method using the obtained dry EVOH pellet, all five monitors did not feel odor, and evaluation was A determination.

  Moreover, when the obtained dry EVOH resin composition (F) pellet was used and the adhesive strength test was done according to the above-mentioned method, the adhesive strength immediately after film formation is 760g / 15mm, and after one week passes from film formation The adhesive strength was 900 g / 15 mm, and good adhesive strength was obtained in all cases.

[Production of modified EVOH (G)]
Modified EVOH (G) was prepared according to the method described below. The raw EVOH and the modified EVOH (G) obtained were analyzed in accordance with the method described in WO 02/092643.

28 parts by weight of zinc acetylacetonate monohydrate was mixed with 957 parts by weight of 1,2-dimethoxyethane to obtain a mixed solution. To the obtained mixed solution, 15 parts by weight of trifluoromethanesulfonic acid was added with stirring to obtain a catalyst solution. That is, a solution in which 1 mol of trifluoromethanesulfonic acid was mixed with 1 mol of zinc acetylacetonate monohydrate was prepared.
EVOH having an ethylene content of 44 mol%, a saponification degree of 99.8%, an intrinsic viscosity of 0.096 L / g, MFR = 5 g / 10 minutes (under 190 ° C. and 2160 g load) {acetic acid content 53 ppm, sodium content 1 ppm (metal) (Element conversion), potassium content 8 ppm (metal element conversion), phosphate compound content 20 ppm (phosphate group conversion value)} pellets were used as the raw material EVOH. Epoxypropane was used as a monovalent epoxy compound having a molecular weight of 500 or less.

  A TEM-35BS extruder (37 mmφ, L / D = 52.5) manufactured by Toshiba Machine Co., Ltd. was used, and the screw configuration, vent and pressure inlet were installed as shown in FIG. The barrel C1 was water cooled, the barrels C2 to C15 were set to 220 ° C., and the operation was performed at a screw rotation speed of 250 rpm. The raw material EVOH is added from the C1 resin feed port at a rate of 11 kg / hr, the vent 1 is decompressed to an internal pressure of 60 mmHg, and the epoxypropane is fed from the C8 pressure inlet 1 at a rate of 2.0 kg / hr. Both were mixed and then fed so that the solution was added at a rate of 0.22 kg / hr (pressure during feeding: 3 MPa). Next, after removing unreacted epoxypropane at normal pressure from the vent 2, an 8.2 wt% aqueous solution of ethylenediaminetetraacetic acid trisodium trihydrate was added as a catalyst deactivator from the inlet 13 of C13 to a concentration of 0.2%. It was added at a rate of 11 kg / hr.

  In the melt kneading operation, the mixing ratio of the monovalent epoxy compound was 18.3 parts by weight with respect to 100 parts by weight of the raw material EVOH. A catalyst of 2 μmol / g in terms of moles of metal ions relative to the weight of the raw EVOH was added. The ratio of the number of moles of catalyst deactivator to the number of moles of metal ions contained in the catalyst solution was 1: 1.

  The vent 3 was depressurized to an internal pressure of 20 mmHg, and water was removed to obtain a modified EVOH (G). The obtained modified EVOH (G) had an MFR of 5 g / 10 min (under a load of 190 ° C. and 2160 g) and a melting point of 105 ° C. The zinc ion content is 120 ppm (1.9 μmol / g), and the alkali metal salt content is 138 ppm (5.9 μmol / g) [sodium: 130 ppm (5.7 μmol / g), potassium: 8 ppm (0.2 μmol / g)], and the content of trifluoromethanesulfonic acid ions was 280 ppm (1.9 μmol / g). The content of alkali metal ions was 3.1 times (molar ratio) the content of trifluoromethanesulfonic acid ions. The modified EVOH (G) thus obtained had an ethylene content of 44 mol% and a structural unit (I) content of 8 mol%.

[Production of resin composition of the present invention]
After 70 parts by weight of the EVOH resin composition (F) and 30 parts by weight of the modified EVOH (G) are dry blended in advance, extrusion is performed under the following conditions, the molten resin strand is cooled with water, and then cut with a pelletizer. As a result, a pellet shape was obtained. The pellet was dried with hot air at 100 ° C. overnight.
Extruder: Nippon Steel Corporation twin screw extruder TEX30α (L / D = 42)
Barrel temperature: C1 / C2 / C3-C12 = water cooling / 190/210 ° C.
Discharge rate: 20kg / hr
Screw rotation speed: 300rpm

[Multi-layer film thermoforming]
Using the resin composition of the present invention as a barrier material, a multilayer film (nylon 6 resin / barrier material / adhesive resin / LLDPE resin) was produced under the following conditions using a four-kind four-layer coextrusion apparatus. The composition of the film is 10 μm for nylon 6 resin (“Ube Nylon 1022B” manufactured by Ube Industries, Ltd.), 20 μm for barrier material, 10 μm for adhesive resin (“Admer NF500” manufactured by Mitsui Chemicals), and LLDPE resin (“Ultzex manufactured by Mitsui Chemicals). 3520L ") is 60 m.

The coextrusion molding conditions are as follows.
Layer structure: nylon 6 resin / barrier material / adhesive resin / LLDPE resin (thickness 10/20/10/60: unit is μm)
Nylon 6 resin extrusion temperature:
C1 / C2 / C3 / C4 = 230/240/250/250 ° C.
Extrusion temperature of adhesive resin:
C1 / C2 / C3 / C4 = 100/170/220/220 ° C.
Barrier extrusion temperature:
C1 / C2 / C3 / C4 = 175/210/230/230 ° C.
Extrusion temperature of LLDPE resin:
C1 / C2 / C3 / C4 = 100/170/220/220 ° C.
Adapter temperature: 250 ° C
Die temperature: 250 ° C
Extruder for each resin, T-die specifications:
Nylon 6 resin:
40φ Extruder UT-40-H type (Plastic Engineering Laboratory Co., Ltd.)
Adhesive resin:
40φ Extruder 10VSE-40-22 (Osaka Seiki Machine Co., Ltd.)
Barrier material:
40φ extruder VSVE-40-24 (Osaka Seiki Machine Co., Ltd.)
LLDPE resin:
65φ extruder 20VS-65-22 (Osaka Seiki Machine Co., Ltd.)
T-die:
650mm width, 4 types, 4 layers (Plastic Engineering Laboratory)
Cooling roll temperature: 30 ° C
Pickup speed: 8m / min

A thermoformed container was obtained by thermoforming the obtained multilayer film using a thermoforming machine (R530 manufactured by Mulchback Co., Ltd.) so that the LLDPE resin was on the inner layer side of the container. In other words, the multilayer film was heated at a mold temperature of 100 ° C. for 2 seconds, and compressed air (atmospheric pressure 5 kgf / cm ² ) was used for the mold shape (vertical: 130 mm, width: 110 mm, depth: 60 mm rectangular parallelepiped shape). Molded to obtain a thermoformed container.

  When the appearance of the obtained thermoformed container was visually observed, it was uniformly stretched without unevenness and local unevenness, and had excellent transparency and good appearance.

[Thermoforming of multilayer sheet]
Using the resin composition of the present invention as a barrier material, a multilayer sheet (polypropylene resin / adhesive resin / barrier material / adhesive resin / polypropylene resin) was prepared using a three-kind five-layer coextrusion apparatus. The layer structure of the film is 420 μm for the inner and outer layer polypropylene resin (“Idemitsu Polypropylene E-203G” manufactured by Idemitsu Petrochemical Co., Ltd.), 40 μm each for the adhesive resin (“Admer QF551” manufactured by Mitsui Chemicals), and the barrier of the intermediate layer The material was 80 μm.

The obtained multilayer sheet was heated to a round cup with compressed air (atmospheric pressure 5 kgf / cm ² ) using a thermoforming machine (manufactured by Asano Manufacturing Co., Ltd .: vacuum pressure / air deep drawing machine FX-0431-3 type) at a sheet temperature of 160 ° C. A thermoformed container was obtained by thermoforming into a shape (mold shape: upper part 75 mmφ, lower part 60 mmφ, depth 75 mm, drawing ratio S = 1.0). The molding conditions are shown below.
Heater temperature: 400 ° C
Plug: 45φ x 65mm
Plug temperature: 150 ° C
Mold temperature: 70 ℃

  When the appearance of the obtained cup-shaped thermoformed container was visually observed, it was uniformly stretched without unevenness and local unevenness, and had excellent transparency and good appearance.

Reference example 1
50 kg of a 45% methanol solution of ethylene-vinyl acetate copolymer having an ethylene content of 32 mol% and 129 kg of methanol were charged into a 470 L saponification reactor, and nitrogen gas was blown into the reactor while the internal temperature was set to 60 ° C. did. Thereto, 29 L (concentration: 80 g / L) of methanol solution of sodium hydroxide is added to start the saponification reaction. During the saponification reaction, methyl acetate generated as a by-product in the reaction system is continuously introduced into the reactor together with methanol in the reaction system in order to drive out the reaction system in order to increase the reaction efficiency. Nitrogen gas was continuously blown. The expelling speed was about 20 kg / hr in total of methyl acetate and methanol, and this was condensed and recovered using a cooling condenser. Two hours after the start of the reaction, 29 L of a methanol solution of sodium hydroxide (concentration: 80 g / L) was further added to drive the saponification reaction. Six hours after the start of the reaction, 6.8 kg of acetic acid and 56 L of water were added to neutralize the reaction solution to stop the reaction.

  The neutralized reaction solution was transferred from the reactor to a drum can and allowed to stand at room temperature for 16 hours to be cooled and solidified into a cake. Thereafter, the cake-like resin was drained using a centrifuge (manufactured by Kokusan Centrifuge Co., Ltd., H-130, rotation speed: 1200 rpm). Next, the step of decanting while continuously supplying ion-exchanged water from above to the center of the centrifuge and washing the resin with water was performed for 10 hours. The conductivity of the cleaning solution 10 hours after the start of cleaning was 30 μS / cm (measured with CM-30ET manufactured by Toa Denpa Kogyo).

  The granular EVOH thus obtained was dried at 60 ° C. for 48 hours using a dryer. 20 kg of dried granular EVOH was dissolved in 43 L of a water / methanol mixed solution (weight ratio: water / methanol = 4/6) at 80 ° C. for 12 hours with stirring. Next, the stirring was stopped and the temperature of the dissolution tank was lowered to 65 ° C. and left for 5 hours to degas the EVOH water / methanol solution. And it extrudes in a 5 degreeC water / methanol mixed solution (weight ratio: water / methanol = 9/1) from the metal plate which has a circular opening part with a diameter of 3.5 mm, precipitates in strand shape, and cuts. To obtain pellets having a diameter of about 4 mm and a length of about 5 mm.

  2.4 kg of the hydrous pellets thus obtained and 24 L of ion-exchanged water were placed in a plastic container having a height of 400 mm and an open diameter of 370 mm, washed with stirring at 25 ° C. for 2 hours, and then drained. Repeated twice. Next, an operation of adding 24 L of 1 g / L acetic acid aqueous solution to 2.4 kg of water-containing pellets, washing the mixture with stirring at 25 ° C. for 2 hours, and then removing the liquid was repeated twice. Further, 24 L of ion exchange water was added to 2.4 kg of the water-containing pellets, and the operation of washing with stirring at 25 ° C. for 2 hours and then draining was repeated 6 times. As a result of measuring the conductivity of the cleaning liquid after the sixth cleaning with CM-30ET manufactured by Toa Denpa Kogyo, the conductivity of the cleaning liquid was 3 μS / cm. The water content of the obtained EVOH pellets was 50% by weight.

  The thus-obtained EVOH after washing (ethylene content 32 mol%, saponification degree 99.98 mol% or more (calculated by NMR method), intrinsic viscosity 0.085 L / g) 2.4 kg hydrous pellets and concentration 0 A 36 g / L boric acid aqueous solution (5.1 L) was placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm, immersed at 25 ° C. for 10 hours, and drained after immersion.

  Next, 5.1 L of ion-exchanged water was placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm. A silicon tube (inner diameter 7 mm, outer diameter 10 mm) was put into the ion-exchanged water in the container, and 0.5 L, 1 L / min. Bubbling at a speed of carbon dioxide was blown. Carbon dioxide was supplied using a carbon dioxide cylinder (liquefied carbon dioxide 30 kg manufactured by Nippon Carbon Co., Ltd.) and a flow meter (Model RK-1600R manufactured by KOFLOC). 0.51 g of boric acid and 0.56 g of sodium carbonate were dissolved in the water into which the carbon dioxide gas was blown, and further, 1 L / min. Carbon dioxide was continuously blown at a speed of. The boric acid content of the treatment liquid was 0.10 g / L, and the sodium carbonate content was 0.11 g / L. Moreover, when the pH of the said processing liquid after blowing in carbon dioxide gas for 1 hour was measured using the pH meter (Metler MA235), the pH of the said processing liquid was 5.1.

  Next, the blowing speed is 1 L / min. Then, 2.4 kg of the above water-containing pellets were added to the treatment liquid while blowing carbon dioxide gas, and immersed and stirred at 25 ° C. for 6 hours. Further, when the pH of the treatment liquid was measured every hour from the start of the treatment to the end of the treatment, the pH of the treatment liquid remained at 5.1 at any measurement and did not vary. It was 20 mmol / L when the carbon dioxide gas density | concentration in a process liquid was analyzed. After stirring for 6 hours by immersing in the treatment liquid, the obtained pellets were immediately drained, followed by hot-air drying at 80 ° C. for 3 hours and then at 107 ° C. for 24 hours to obtain a dried EVOH resin composition ( F) Pellets (water content 0.2% by weight) were obtained.

  The alkali metal salt (A) in the obtained dried EVOH resin composition (F) pellets was sodium, and the content of the alkali metal salt (A) was 3.13 μmol / g in terms of metal element. The boron compound (B) content in the obtained dry EVOH resin composition (F) pellets was 160 ppm (15 μmol / g) in terms of boron element. Further, the amount of the carboxylate radical (C1) extracted by immersing the dry EVOH resin composition (F) pellets in 95 ° C. pure water for 10 hours is 0 ppm (0 μmol / g), and the 0.05 ° C. at 95 ° C. is 0.05. The amount of carboxylic acid (acetic acid) root (C2) extracted by immersion in a prescribed aqueous sodium hydroxide solution for 10 hours was 35 ppm (0.6 μmol / g). The MFR of the dried EVOH resin composition (F) pellet was 1.6 g / 10 min. (Under 190 ° C. and 2160 g load).

  Using the obtained dried EVOH resin composition (F) pellets, a single-layer film was prepared according to the above-described method, and a test for resistance to coloring and long run was performed. The evaluation results of the color resistance, 72 hour long run property, and 120 hour long run property of the EVOH resin composition (F) of this reference example were all determined as A.

  Using the obtained dried EVOH resin composition (F) pellets, a high-temperature colorability evaluation test was performed according to the above-described method. Moreover, when the odor test was done according to the above-mentioned method using the obtained dry EVOH pellet, all five monitors did not feel odor, and evaluation was A determination.

  Moreover, when the adhesive strength test was done according to the above-mentioned method using the obtained dry EVOH resin composition (F) pellet, the adhesive strength immediately after film formation was 550 g / 15 mm, and after one week has elapsed since film formation. The adhesive strength was 800 g / 15 mm, and good adhesive strength was obtained in all cases.

Reference Examples 2-6
Dry EVOH resin in the same manner as in Reference Example 1 except that the composition of the carbon dioxide-containing treatment liquid into which the hydrous EVOH pellets are immersed after being immersed in the boric acid aqueous solution is changed as shown in Table 1. Composition (F) pellets were prepared and evaluated in the same manner as in Reference Example 1. Table 2 shows the composition of the dry EVOH resin composition (F) pellets, and Table 3 shows the evaluation results.

Reference Example 7
50 kg of a 45% methanol solution of ethylene-vinyl acetate copolymer having an ethylene content of 44 mol% and 129 kg of methanol were charged into a 470 L saponification reactor, and the internal temperature was set to 60 ° C. while blowing nitrogen gas into the reactor. did. Thereto, 29 L (concentration: 80 g / L) of methanol solution of sodium hydroxide is added to start the saponification reaction. During the saponification reaction, methyl acetate generated as a by-product in the reaction system is continuously introduced into the reactor together with methanol in the reaction system in order to drive out the reaction system in order to increase the reaction efficiency. Nitrogen gas was continuously blown. The expelling speed was about 20 kg / hr in total of methyl acetate and methanol, and this was condensed and recovered using a cooling condenser. Two hours after the start of the reaction, 29 L of a methanol solution of sodium hydroxide (concentration: 80 g / L) was further added to drive the saponification reaction. Six hours after the start of the reaction, 6.8 kg of acetic acid and 45 L of water were added to neutralize the reaction solution to stop the reaction.

  The neutralized reaction solution was transferred from the reactor to a drum can and allowed to stand at room temperature for 16 hours to be cooled and solidified into a cake. Thereafter, the cake-like resin was drained using a centrifuge (manufactured by Kokusan Centrifuge Co., Ltd., H-130, rotation speed: 1200 rpm). Next, the step of decanting while continuously supplying ion-exchanged water from above to the center of the centrifuge and washing the resin with water was performed for 10 hours. The conductivity of the cleaning solution 10 hours after the start of cleaning was 30 μS / cm (measured with CM-30ET manufactured by Toa Denpa Kogyo).

  The granular EVOH thus obtained was dried at 60 ° C. for 48 hours using a dryer. 20 kg of dried granular EVOH was dissolved in 48 L of a water / methanol mixed solution (weight ratio: water / methanol = 2/8) at 80 ° C. for 12 hours with stirring. Next, the stirring was stopped and the temperature of the dissolution tank was lowered to 65 ° C. and left for 5 hours to degas the EVOH water / methanol solution. And it extrudes in a 5 degreeC water / methanol mixed solution (weight ratio: water / methanol = 9/1) from the metal plate which has a circular opening part with a diameter of 3.5 mm, precipitates in strand shape, and cuts. To obtain pellets having a diameter of about 4 mm and a length of about 5 mm.

  2.4 kg of the hydrous pellets thus obtained and 24 L of ion-exchanged water were placed in a plastic container having a height of 400 mm and an open diameter of 370 mm, washed with stirring at 25 ° C. for 2 hours, and then drained. Repeated twice. Next, an operation of adding 24 L of 1 g / L acetic acid aqueous solution to 2.4 kg of water-containing pellets, washing the mixture with stirring at 25 ° C. for 2 hours, and then removing the liquid was repeated twice. Further, 24 L of ion exchange water was added to 2.4 kg of the water-containing pellets, and the operation of washing with stirring at 25 ° C. for 2 hours and then draining was repeated 6 times. As a result of measuring the conductivity of the cleaning liquid after the sixth cleaning with CM-30ET manufactured by Toa Denpa Kogyo, the conductivity of the cleaning liquid was 3 μS / cm. The water content of the obtained EVOH pellets was 50% by weight.

  The thus-obtained EVOH after washing (ethylene content 44 mol%, saponification degree 99.98 mol% or more (calculated by NMR method), inherent viscosity 0.088 L / g) 2.4 kg hydrous pellets and concentration 0 A 51 g / L boric acid aqueous solution (5.1 L) was placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm, immersed at 25 ° C. for 10 hours, and drained after immersion.

  Next, 24L of ion-exchanged water was placed in a plastic container having a height of 400 mm and an open diameter of 370 mm. A silicon tube (inner diameter: 7 mm, outer diameter: 10 mm) was put into the ion-exchanged water in the container (using five of the above-mentioned silicon tubes), and 2 L, 5 L / min. Bubbling at a speed of carbon dioxide was blown. Carbon dioxide was supplied using a carbon dioxide cylinder (liquefied carbon dioxide 30 kg manufactured by Nippon Carbon Co., Ltd.) and a flow meter (Model RK-1600R manufactured by KOFLOC). 2.88 g of boric acid, 4.08 g of potassium hydrogen carbonate, and 6.17 g of potassium dihydrogen phosphate are dissolved in the water into which the carbon dioxide gas has been blown, and further, 5 L / min. Carbon dioxide was continuously blown at a speed of. The treatment solution had a boric acid content of 0.12 g / L, a potassium hydrogen carbonate content of 0.17 g / L, and a potassium dihydrogen phosphate of 0.257 g / L. Moreover, when the pH of the said processing liquid after blowing in carbon dioxide gas for 1 hour was measured using the pH meter (Metler MA235), the pH of the said processing liquid was 5.1.

  Next, the blowing speed is 5 L / min. Then, 2.4 kg of the above water-containing pellets were added to the treatment liquid while blowing carbon dioxide gas, and immersed and stirred at 25 ° C. for 6 hours. Further, when the pH of the treatment liquid was measured every hour from the start of the treatment to the end of the treatment, the pH of the treatment liquid remained at 5.1 at any measurement and did not vary. As a result of analyzing the carbon dioxide gas concentration in the treatment liquid, it was 20 mmol / L. After stirring for 6 hours by immersing in the treatment liquid, the obtained pellets were immediately drained, followed by hot-air drying at 80 ° C. for 3 hours and then at 107 ° C. for 24 hours to obtain a dried EVOH resin composition ( F) Pellets (water content 0.2% by weight) were obtained.

  The alkali metal salt (A) in the obtained dried EVOH resin composition (F) pellets was potassium, and the content of the alkali metal salt (A) was 5.4 μmol / g in terms of metal element. The content (d1) of the phosphoric acid compound (D) was 0.5 μmol / g in terms of phosphate radical. The content of the boron compound (B) in the obtained dried EVOH resin composition (F) pellets was 242 ppm (22 μmol / g) in terms of boron element. Moreover, the amount of the carboxylic acid radical (C1) extracted by immersing the dried EVOH resin composition (F) pellets in pure water at 95 ° C. for 10 hours is 0 ppm (0 μmol / g), and the amount of 0.1% at 95 ° C. is 0. The amount of carboxylic acid (acetic acid) root (C2) extracted by immersion in a 05 normal aqueous sodium hydroxide solution for 10 hours was 36 ppm (0.6 μmol / g). The MFR of the dried EVOH resin composition (F) pellet was 1.6 g / 10 min. (Under 190 ° C. and 2160 g load).

  Using the obtained dried EVOH resin composition (F) pellets, a single-layer film was prepared according to the above-described method, and a test for resistance to coloring and long run was performed. The evaluation results of the color resistance, 72 hour long run property, and 120 hour long run property of the EVOH resin composition (F) of this reference example were all determined as A. Moreover, content (d2) of the phosphoric acid compound (D) of a single layer film was 0.03 micromol / g in conversion of the phosphoric acid radical, and phosphorus element content (t) was 0.5 micromol / g. The content of the organophosphorus compound that can be extracted with chloroform was less than 0.01 μmol / g.

  Using the obtained dried EVOH resin composition (F) pellets, a high-temperature colorability evaluation test was performed according to the above-described method. Moreover, when the odor test was done according to the above-mentioned method using the obtained dry EVOH pellet, all five monitors did not feel odor, and evaluation was A determination.

  Moreover, when the obtained dry EVOH resin composition (F) pellet was used and the adhesive strength test was done according to the above-mentioned method, the adhesive strength immediately after film formation is 760g / 15mm, and after one week passes from film formation The adhesive strength was 880 g / 15 mm, and good adhesive strength was obtained in all cases.

Reference Example 8
50 kg of a 45% methanol solution of ethylene-vinyl acetate copolymer having an ethylene content of 27 mol% and 129 kg of methanol were charged into a 470 L saponification reactor, and the internal temperature was set to 60 ° C. while blowing nitrogen gas into the reactor. did. Thereto, 29 L (concentration: 80 g / L) of methanol solution of sodium hydroxide is added to start the saponification reaction. During the saponification reaction, methyl acetate generated as a by-product in the reaction system is continuously introduced into the reactor together with methanol in the reaction system in order to drive out the reaction system in order to increase the reaction efficiency. Nitrogen gas was continuously blown. The expelling speed was about 20 kg / hr in total of methyl acetate and methanol, and this was condensed and recovered using a cooling condenser. Two hours after the start of the reaction, 29 L of a methanol solution of sodium hydroxide (concentration: 80 g / L) was further added to drive the saponification reaction. Six hours after the start of the reaction, 6.8 kg of acetic acid and 56 L of water were added to neutralize the reaction solution to stop the reaction.

  The neutralized reaction solution was transferred from the reactor to a drum can and allowed to stand at room temperature for 16 hours to be cooled and solidified into a cake. Thereafter, the cake-like resin was drained using a centrifuge (manufactured by Kokusan Centrifuge Co., Ltd., H-130, rotation speed: 1200 rpm). Next, the step of decanting while continuously supplying ion-exchanged water from above to the center of the centrifuge and washing the resin with water was performed for 10 hours. The conductivity of the cleaning solution 10 hours after the start of cleaning was 30 μS / cm (measured with CM-30ET manufactured by Toa Denpa Kogyo).

  The granular EVOH thus obtained was dried at 60 ° C. for 48 hours using a dryer. 20 kg of dried granular EVOH was dissolved in 43 L of a water / methanol mixed solution (weight ratio: water / methanol = 5/5) with stirring at 80 ° C. for 12 hours. Next, the stirring was stopped and the temperature of the dissolution tank was lowered to 65 ° C. and left for 5 hours to degas the EVOH water / methanol solution. And it extrudes in a 5 degreeC water / methanol mixed solution (weight ratio: water / methanol = 9/1) from the metal plate which has a circular opening part with a diameter of 3.5 mm, precipitates in strand shape, and cuts. To obtain pellets having a diameter of about 4 mm and a length of about 5 mm.

  2.4 kg of the hydrous pellets thus obtained and 24 L of ion-exchanged water were placed in a plastic container having a height of 400 mm and an open diameter of 370 mm, washed with stirring at 25 ° C. for 2 hours, and then drained. Repeated twice. Next, an operation of adding 24 L of 1 g / L acetic acid aqueous solution to 2.4 kg of water-containing pellets, washing the mixture with stirring at 25 ° C. for 2 hours, and then removing the liquid was repeated twice. Further, 24 L of ion exchange water was added to 2.4 kg of the water-containing pellets, and the operation of washing with stirring at 25 ° C. for 2 hours and then draining was repeated 6 times. As a result of measuring the conductivity of the cleaning liquid after the sixth cleaning with CM-30ET manufactured by Toa Denpa Kogyo, the conductivity of the cleaning liquid was 3 μS / cm. The water content of the obtained EVOH pellets was 50% by weight.

  The thus obtained EVOH after washing (ethylene content 27 mol%, saponification degree 99.98 mol% or more (calculated by NMR method), intrinsic viscosity 0.094 L / g), 2.4 kg hydrous pellets and concentration 0 . 5 L of 30 g / L boric acid aqueous solution was placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm, immersed at 25 ° C. for 10 hours, and drained after immersion.

  Next, 5 L of ion-exchanged water was put in a plastic container having a height of 300 mm and an opening diameter of 280 mm. A silicon tube (inner diameter 7 mm, outer diameter 10 mm) was put into the ion-exchanged water in the container, and 0.5 L, 1 L / min. Bubbling at a speed of carbon dioxide was blown. Carbon dioxide was supplied using a carbon dioxide cylinder (liquefied carbon dioxide 30 kg manufactured by Nippon Carbon Co., Ltd.) and a flow meter (Model RK-1600R manufactured by KOFLOC). In the water into which the carbon dioxide gas was blown, 0.35 g of boric acid, 0.65 g of potassium hydrogen carbonate, and 0.85 g of potassium dihydrogen phosphate were dissolved, and further, 1 L / min. Carbon dioxide was continuously blown at a speed of. The treatment liquid had a boric acid content of 0.07 g / L, a potassium hydrogen carbonate content of 0.13 g / L, and a potassium dihydrogen phosphate content of 0.17 g / L. Moreover, when the pH of the said process liquid after blowing in carbon dioxide gas for 1 hour was measured using the pH meter (Metler MA235), the pH of the said process liquid was 5.0.

  Next, the blowing speed is 1 L / min. Then, 2.4 kg of the above water-containing pellets were added to the treatment liquid while blowing carbon dioxide gas, and immersed and stirred at 25 ° C. for 6 hours. Further, when the pH of the treatment liquid was measured every hour from the start of the treatment to the end of the treatment, the pH of the treatment liquid remained at 5 and remained unchanged at any measurement time. It was 20 mmol / L when the carbon dioxide gas density | concentration in a process liquid was analyzed. After stirring for 6 hours by immersing in the treatment liquid, the obtained pellets were immediately drained, followed by hot-air drying at 80 ° C. for 3 hours and then at 107 ° C. for 24 hours to obtain a dried EVOH resin composition ( F) Pellets (water content 0.2% by weight) were obtained.

  The alkali metal salt (A) in the obtained dried EVOH resin composition (F) pellets is potassium, the content of the alkali metal salt (A) is 2.6 μmol / g in terms of metal element, and the phosphoric acid compound The content (d1) of (D) was 0.4 μmol / g in terms of phosphate radical. The boron compound (B) content in the obtained dry EVOH resin composition (F) pellets was 160 ppm (15 μmol / g) in terms of boron element. Moreover, the amount of the carboxylic acid radical (C1) extracted by immersing the dried EVOH resin composition (F) pellets in pure water at 95 ° C. for 10 hours is 0 ppm (0 μmol / g), and the amount of 0.1% at 95 ° C. is 0. The amount of carboxylic acid (acetic acid) root (C2) extracted by immersion in an aqueous 05 normal sodium hydroxide solution for 10 hours was 35 ppm (0.6 μmol / g). Moreover, MFR of the said dry EVOH resin composition (F) pellet is 4.0 g / 10min. (210 ° C., 2160 g under load).

  Using the obtained dried EVOH resin composition (F) pellets, a single-layer film was prepared according to the above-described method, and a test for resistance to coloring and long run was performed. The EVOH resin composition (F) of this reference example had a color resistance of B, 72 hours of long run properties evaluated as A, and 120 hours of long run properties evaluated as B. Moreover, content (d2) of the phosphoric acid compound (D) of a single layer film was 0.02 micromol / g in conversion of a phosphoric acid radical, and phosphorus element content (t) was 0.4 micromol / g. The content of the organophosphorus compound that can be extracted with chloroform was less than 0.01 μmol / g.

  Using the obtained dried EVOH resin composition (F) pellets, a high-temperature colorability evaluation test was performed according to the above-described method. Moreover, when the odor test was done according to the above-mentioned method using the obtained dry EVOH pellet, all five monitors did not feel odor, and evaluation was A determination.

  Moreover, when the adhesive strength test was done according to the above-mentioned method using the obtained dry EVOH resin composition (F) pellet, the adhesive strength immediately after film formation is 800 g / 15 mm, and after one week has passed since film formation. The adhesive strength was 950 g / 15 mm, and good adhesive strength was obtained in all cases.

Reference Example 9
50 kg of a 45% methanol solution of ethylene-vinyl acetate copolymer having an ethylene content of 47 mol% and 129 kg of methanol were charged into a 470 L saponification reactor, and the internal temperature was set to 60 ° C. while blowing nitrogen gas into the reactor. did. Thereto, 29 L (concentration: 80 g / L) of methanol solution of sodium hydroxide is added to start the saponification reaction. During the saponification reaction, methyl acetate generated as a by-product in the reaction system is continuously introduced into the reactor together with methanol in the reaction system in order to drive out the reaction system in order to increase the reaction efficiency. Nitrogen gas was continuously blown. The expelling speed was about 20 kg / hr in total of methyl acetate and methanol, and this was condensed and recovered using a cooling condenser. Two hours after the start of the reaction, 29 L of a methanol solution of sodium hydroxide (concentration: 80 g / L) was further added to drive the saponification reaction. Six hours after the start of the reaction, 6.8 kg of acetic acid and 45 L of water were added to neutralize the reaction solution to stop the reaction.

  The neutralized reaction solution was transferred from the reactor to a drum can and allowed to stand at room temperature for 16 hours to be cooled and solidified into a cake. Thereafter, the cake-like resin was drained using a centrifuge (manufactured by Kokusan Centrifuge Co., Ltd., H-130, rotation speed: 1200 rpm). Next, the step of decanting while continuously supplying ion-exchanged water from above to the center of the centrifuge and washing the resin with water was performed for 10 hours. The conductivity of the cleaning solution 10 hours after the start of cleaning was 30 μS / cm (measured with CM-30ET manufactured by Toa Denpa Kogyo).

  The granular EVOH thus obtained was dried at 60 ° C. for 48 hours using a dryer. 20 kg of dried granular EVOH was dissolved in 43 L of a water / methanol mixed solution (weight ratio: water / methanol = 2/8) at 80 ° C. for 12 hours with stirring. Next, the stirring was stopped and the temperature of the dissolution tank was lowered to 65 ° C. and left for 5 hours to degas the EVOH water / methanol solution. And it extrudes in a 5 degreeC water / methanol mixed solution (weight ratio: water / methanol = 9/1) from the metal plate which has a circular opening part with a diameter of 3.5 mm, precipitates in strand shape, and cuts. To obtain pellets having a diameter of about 4 mm and a length of about 5 mm.

  2.4 kg of the hydrous pellets thus obtained and 24 L of ion-exchanged water were placed in a plastic container having a height of 400 mm and an open diameter of 370 mm, washed with stirring at 25 ° C. for 2 hours, and then drained. Repeated twice. Next, an operation of adding 24 L of 1 g / L acetic acid aqueous solution to 2.4 kg of water-containing pellets, washing the mixture with stirring at 25 ° C. for 2 hours, and then removing the liquid was repeated twice. Further, 24 L of ion exchange water was added to 2.4 kg of the water-containing pellets, and the operation of washing with stirring at 25 ° C. for 2 hours and then draining was repeated 6 times. As a result of measuring the conductivity of the cleaning liquid after the sixth cleaning with CM-30ET manufactured by Toa Denpa Kogyo, the conductivity of the cleaning liquid was 3 μS / cm. The water content of the obtained EVOH pellets was 50% by weight.

  The thus obtained EVOH after washing (ethylene content 47 mol%, saponification degree 99.98 mol% or more (calculated by NMR method), intrinsic viscosity 0.082 L / g) 2.4 kg hydrous pellets and concentration 0 . 5L of a 21 g / L boric acid aqueous solution was placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm, immersed at 25 ° C. for 10 hours, and drained after immersion.

  Next, 5 L of ion-exchanged water was put in a plastic container having a height of 300 mm and an opening diameter of 280 mm. A silicon tube (inner diameter 7 mm, outer diameter 10 mm) was put into the ion-exchanged water in the container, and 0.5 L, 1 L / min. Bubbling at a speed of carbon dioxide was blown. Carbon dioxide was supplied using a carbon dioxide cylinder (liquefied carbon dioxide 30 kg manufactured by Nippon Carbon Co., Ltd.) and a flow meter (Model RK-1600R manufactured by KOFLOC). In the water into which the carbon dioxide gas was blown, 0.20 g of boric acid, 1.15 g of potassium hydrogen carbonate, and 0.55 g of potassium dihydrogen phosphate were dissolved, and further for 1 hour at 1 L / min. Carbon dioxide was continuously blown at a speed of. The treatment liquid had a boric acid content of 0.04 g / L, a potassium hydrogen carbonate content of 0.23 g / L, and a potassium dihydrogen phosphate content of 0.11 g / L. Moreover, when the pH of the said processing liquid after blowing in carbon dioxide gas for 1 hour was measured using the pH meter (Metler MA235), the pH of the said processing liquid was 5.2.

  Next, the blowing speed is 1 L / min. Then, 2.4 kg of the above water-containing pellets were added to the treatment liquid while blowing carbon dioxide gas, and immersed and stirred at 25 ° C. for 6 hours. Further, when the pH of the treatment liquid was measured every hour from the start of the treatment to the end of the treatment, the pH of the treatment liquid remained at 5.2 at any measurement and did not vary. It was 20 mmol / L when the carbon dioxide gas density | concentration in a process liquid was analyzed. After being immersed in the treatment solution for 6 hours and stirring, the obtained pellets were immediately drained, dried by hot air drying at 80 ° C. for 3 hours and then at 107 ° C. for 24 hours, and then EVOH resin Composition (F) pellets (water content 0.2 wt%) were obtained.

  The alkali metal salt (A) in the obtained dried EVOH resin composition (F) pellets is potassium, the content of the alkali metal salt (A) is 5.6 μmol / g in terms of metal element, and the phosphate compound The content (d1) of (D) was 0.5 μmol / g in terms of phosphate radical. The boron compound (B) content in the obtained dried EVOH resin composition (F) pellets was 110 ppm (10 μmol / g) in terms of boron element. Moreover, the amount of the carboxylic acid radical (C1) extracted by immersing the dried EVOH resin composition (F) pellets in pure water at 95 ° C. for 10 hours is 0 ppm (0 μmol / g), and the amount of 0.1% at 95 ° C. is 0. The amount of carboxylic acid (acetic acid) root (C2) extracted by immersion in an aqueous 05 normal sodium hydroxide solution for 10 hours was 35 ppm (0.6 μmol / g). The MFR of the dried EVOH resin composition (F) pellet was 6.2 g / 10 min. (Under 190 ° C. and 2160 g load).

  Using the obtained dried EVOH resin composition (F) pellets, a single-layer film was prepared according to the above-described method, and a test for resistance to coloring and long run was performed. The evaluation results of the color resistance, 72 hour long run property, and 120 hour long run property of the EVOH resin composition (F) of this reference example were all determined as A. Moreover, content (d2) of the phosphoric acid compound (D) of a single layer film was 0.03 micromol / g in conversion of the phosphoric acid radical, and phosphorus element content (t) was 0.5 micromol / g. The content of the organophosphorus compound that can be extracted with chloroform was less than 0.01 μmol / g.

  Using the obtained dried EVOH resin composition (F) pellets, a high-temperature colorability evaluation test was performed according to the above-described method. Moreover, when the odor test was done according to the above-mentioned method using the obtained dry EVOH pellet, all five monitors did not feel odor, and evaluation was A determination.

  Moreover, when the adhesive strength test was done according to the above-mentioned method using the obtained dry EVOH resin composition (F) pellet, the adhesive strength immediately after film formation was 700 g / 15 mm, and after one week has elapsed since film formation. The adhesive strength was 880 g / 15 mm, and good adhesive strength was obtained in all cases.

Reference Example 10
2.4 kg of washed hydrous pellets obtained in the same manner as in Reference Example 1 and 5.1 L of boric acid aqueous solution with a concentration of 0.36 g / L were placed in a plastic container having a height of 300 mm and an opening diameter of 280 mm, and 25 ° C. For 10 hours, and after immersion, the liquid was drained.

  Subsequently, the hydrated pellets after liquid removal were immersed in 5.1 L of an aqueous solution containing 0.56 g / L acetic acid and 0.025 g / L sodium acetate for 6 hours at 25 ° C. and stirred. Thereafter, the solution was drained and dried with hot air at 80 ° C. for 3 hours and then at 107 ° C. for 24 hours to obtain dry EVOH resin composition pellets (water content: 0.2% by weight). Various evaluations were performed in the same manner as in Reference Example 1 using the obtained dried pellets. Table 2 shows the composition of the dry EVOH resin composition, and Table 3 shows the evaluation results.

Reference Example 11
Dry EVOH resin composition pellets were produced in the same manner as in Reference Example 10 except that the composition of the treatment liquid in which the washed water-containing pellets were immersed was changed as shown in Table 1. Various evaluations were performed in the same manner as in Reference Example 1 using the obtained dried pellets. Table 2 shows the composition of the dry EVOH resin composition, and Table 3 shows the evaluation results.

Reference Example 12
Example of a water-containing EVOH pellet containing 50% by weight of a saponification catalyst residue having an ethylene content of 32 mol%, a saponification degree of 99.6 mol% (calculated from NMR method), and an intrinsic viscosity of 0.085 L / g Washed as in 10.

  A dry EVOH resin composition pellet was prepared in the same manner as in Reference Example 10 except that the above prepared water-containing pellet was used as the water-containing pellet and the composition of the liquid in which the obtained water-containing pellet was immersed was changed as shown in Table 1. Produced. Various evaluations were performed in the same manner as in Reference Example 1 using the obtained dried pellets. Table 2 shows the composition of the dry EVOH resin composition, and Table 3 shows the evaluation results.

Reference Example 13
Dry EVOH resin composition pellets were produced in the same manner as in Reference Example 10 except that the composition of the treatment liquid in which the washed water-containing pellets were immersed was changed as shown in Table 1. Various evaluations were performed in the same manner as in Reference Example 1 using the obtained dried pellets. Table 2 shows the composition of the dry EVOH resin composition, and Table 3 shows the evaluation results.

  Moreover, although EVOH which changed ethylene content from 27 mol% to 47 mol% was used in Example 1 and Reference Examples 7-9, alkali metal salt ( It has been found that it is preferable to increase the content of A). The content of the alkali metal (A) in the present Example 1 and Reference Examples 7 to 9 is based on such knowledge, and the amount of the alkali metal salt (A) considered to be optimal for each ethylene content is determined. It is a blend.

  FIG. 2 is a graph showing the relationship between ethylene content (ET) and alkali metal salt (A) content (a) in Example 1 and Reference Examples 7-9. When an approximate curve was obtained by exponential approximation from the plotted four points of data, an approximate expression of “a = 0.95 × exp (0.039 × ET)” was obtained. The alkali metal salt (A) having a width in the range of 2 μmol / g above and below is preferable.

1 is a schematic diagram of a configuration of an extruder used for producing modified EVOH (G) in Example 1. FIG. It is the graph which showed the relationship between ethylene content (ET) and alkali metal salt (A) content (a) in Example 1 and Reference Examples 7-9.

Claims (7)

Containing 0.1 to 20 μmol / g of alkali metal salt (A) in terms of alkali metal, 0 to 2 μmol / g of carboxylic acid group (C1) extracted by immersion in 95 ° C. water for 10 hours, and Ethylene-vinyl alcohol copolymer resin composition (F) 1 to 99 containing 0 to 40 μmol / g of carboxylic acid radical (C2) extracted by immersion in an aqueous 0.05 N sodium hydroxide solution at 95 ° C. for 10 hours. A resin composition comprising 1% by weight and 1 to 99% by weight of a modified ethylene-vinyl alcohol copolymer (G) having an ethylene content of 5 to 55% by mole and containing 0.3 to 40% by mole of the following structural unit (I) object.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same group. And may be different . ) Containing 0.1 to 20 μmol / g of alkali metal salt (A) in terms of alkali metal, 0 to 2 μmol / g of carboxylic acid group (C1) extracted by immersion in 95 ° C. water for 10 hours, and Ethylene containing 1 to 99% by weight of an ethylene-vinyl alcohol copolymer resin composition (F) having a saponification degree of 99.7 to 100% by mole and 0.3 to 40% by mole of the following structural unit (I) A resin composition comprising 1 to 99% by weight of a modified ethylene-vinyl alcohol copolymer (G) having a content of 5 to 55 mol%.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same group. And may be different . ) The resin composition according to claim 1 or 2, wherein the alkali metal salt (A) is a potassium salt. The resin composition according to any one of claims 1 to 3, wherein the ethylene-vinyl alcohol copolymer resin composition (F) contains the boron compound (B) in an amount of 1 to 200 µmol / g in terms of boron element. The resin composition according to any one of claims 1 to 4, wherein the phosphorus element content (t) of the ethylene-vinyl alcohol copolymer resin composition (F) is 0.05 to 5 µmol / g in terms of phosphorus element. A molded product formed by molding the resin composition according to claim 1. After contacting the ethylene-vinyl alcohol copolymer resin with an aqueous solution containing the alkali metal salt (A) 0.05 to 40 mmol / L and containing carbon dioxide gas of 0.5 mmol / L or more, the following structural unit ( ethylene content from 5 to 55 mol% of a modified ethylene containing I) 0.3 to 40 mol% - claimed in any of claims 1 to 5 vinyl alcohol copolymer (G), wherein the melt-kneading the method for producing the resin composition.

(In the formula, R ¹ , R ² , R ³ and R ⁴ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 10 carbon atoms. R ¹ , R ² , R ³ and R ⁴ may be the same group. And may be different.)

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