WO2001096464A1 - Ethylene/vinyl alcohol copolymer resin composition - Google Patents

Abstract

An ethylene/vinyl alcohol copolymer resin composition having a content of carboxylic acids (A) of 0.05 to 2.5 νmol/g and a content of alkaline earth metal salts (B) of 10 ppm or below (in terms of metal elements) and satisfying the following relationship (1); and multilayer structures made by using the composition (1); wherein (A) is the total content (νmol/g) of carboxylic acids (A) and salts thereof; and (a1) is the content (νmol/g) of carboxylic acids (a1) having molecular weights of 75 or above and salts thereof.

Description

 Description Ethylene monobutyl alcohol copolymer resin composition

 The present invention has excellent color appearance, low unevenness of film surface, excellent appearance, long run and low odor even at the time of melt molding at a high temperature, such as during co-extrusion molding or co-injection molding with a resin having a high melting point. TECHNICAL FIELD The present invention relates to an ethylene-vinyl alcohol copolymer resin composition excellent in water resistance and a multilayer structure using the same. Background art

 Ethylene-Biel alcohol copolymer (hereinafter sometimes abbreviated as EVOH) is a useful polymer material with excellent oxygen-shielding properties, oil resistance, antistatic properties, mechanical strength, etc., and various types of films, sheets, containers, etc. Widely used as packaging material. Such packaging materials are usually produced by melt molding, and have a long run property during melt molding (a molded article free of fish eyes is obtained even over a long period of time), and the appearance of the molded article ( (A molded product with little coloring and no generation of fish eyes) is required.

 Therefore, conventionally, as a countermeasure for this, the following proposals have been made for producing a good molded product by treating EVOH with various acids and metal salts.

For example, in order to improve coloring, appearance, and interlayer adhesion, (1) 100 to 5000 ppm of hydroxycarboxylic acid and / or its salt in terms of hydroxycarboxylic acid, and 50 to 50 ppm in terms of metal An EVOH composition characterized by containing 500 ppm of an alkaline earth metal salt in an amount of 20 to 200 ppm in terms of a metal element has been disclosed (JP-A-10-67898). In addition, (2) alkali metal acetates are 20 to 200 ppm in terms of metal elements and belong to Group II of the periodic table. 10 ppm or less of metal, 30-250 ppm of acetic acid and 5-500 ppm of phosphoric acid or alkali metal hydrogen phosphate in terms of phosphate group, the acetic acid content / alkaline metal acetate content In the relationship between the heating time and the discharge speed in the Koka type flow tester at at least one point at a temperature of 0.1 to 1 and 10 to 80 ° C higher than the melting point, the discharge speed is at least up to 10 hours. not substantially increase, E styrene content of 20 to 80 mole _^0/0, a saponification degree of 95 mol% or more E styrene monoacetate Bulle copolymer saponified composition acetate Bulle component is disclosed (JP-a-2 — 23 5952; USP 5194474).

 EVOH is often used by being laminated with another thermoplastic resin, and there are many embodiments in which EVOH is laminated with polyolefin through an adhesive resin made of modified polyolefin. In such a case, both the polyolefin and the adhesive resin laminated with EVOH usually have a lower melting point than EVOH, and can be molded at the most desirable molding temperature for molding EVOH. Even when the EVOH resin compositions described in (1) and (2) were used, there were not many problems during molding.

 On the other hand, in another embodiment, polyamide, polyester, etc. are higher than EVOH! There are many embodiments in which a multi-layer structure is molded by co-injection molding with a resin having a melting point. However, when producing a multilayer structure composed of an EVOH layer, a polyamide layer and / or a polyester layer by co-extrusion molding or co-injection molding, molding is performed at a high molding temperature suitable for molding polyamide or polyester. EVOH tends to deteriorate due to heating. Conversely, when molding is performed at the most preferable molding temperature for molding EVOH, the moldability may be insufficient because the polyamide or polyester is not sufficiently melted. Therefore, even when molding at a high molding temperature suitable for molding polyamide or polyester, there is a need for the development of EVOH with low thermal degradation.

However, the techniques disclosed in the above (1) and (2) do not dissolve at high temperatures. There is no description about melt molding, and the EVOH compositions described in (1) and (2) cannot provide sufficient performance at the time of melt molding at high temperatures. Specifically, the EVOH composition described in the prior art (1) has unsatisfactory coloring resistance and long-run property at the time of molding at a high temperature.

 On the other hand, the prior art (2) aims to reduce the generation of odor components, but the effect of improving odor is not always satisfactory. In addition, in the case of co-extrusion molding or co-injection molding with a resin having a higher melting point than EVOH, such as polyamide-polyester, the composition described in the prior art (2) is not suitable for melt-molding at high temperatures. Things left room for improvement.

 As described above, even during melt molding at a high temperature, such as during co-extrusion molding or co-injection molding with a resin having a high melting point, coloration, film surface unevenness is excellent, appearance is excellent, and long run properties and An EVOH resin composition with excellent low odor has not been found yet, and its development is strongly demanded. Disclosure of the invention

 The problem described above is that the content of carboxylic acid (A) is 0.05 to 2.5 μιηοΐ / g and the content of alkaline earth metal salt (B) is 10 ppm or less (metal The problem is solved by providing an ethylene-butyl alcohol copolymer resin composition that is an element-converted value and satisfies the following formula (1).

 0.7 ≤ (a l) / (A) ≤ 1.0 (1)

However,

 (A): Total content of carboxylic acid (A) and its salts (molZg)

(a 1): the content of a carboxylic acid having a molecular weight of 75 or more (a 1) and a salt thereof (μπιοΐ In a preferred embodiment, a carboxylic acid having a molecular weight of 75 or more (a 1) is used. And particularly preferably lactic acid. In a preferred embodiment, the content of the phosphoric acid compound (C) in the resin composition of the present invention is 8 Oppm or less (in terms of phosphate radical).

 In a preferred embodiment, the resin composition of the present invention contains the boron compound (E) in an amount of 50 to 2000 ppm in terms of elemental boron.

 In a preferred embodiment, the MFR (MFR (6 min.); 270 ° C, 2160 g load) when the resin composition is maintained at 270 ° C for 6 minutes in a melt indexer; MFR when held at 270 ° C for 10 minutes, 20 minutes, and 30 minutes (MFR (10 min.), MFR (20 min.) ヽ MFR (30 min.); Deviation is 270 ° (:, 2160 g load) satisfies all of the following equations (2) to (4).

 0.5≤MFR (lOmin.) / MFR (6min.) ≤1.5 (2)

 0.5≤MFR (20min.) / MFR (6min.) ≤1.5 (3)

 0.5≤MFR (30min.) / MFR (6min.) ≤1.5 (4)

 Further, the present invention relates to a multilayer structure obtained by laminating a thermoplastic resin on at least one surface of a layer made of the resin composition. In a preferred embodiment, such a thermoplastic resin is a polyamide or a polyester. Further, in a preferred embodiment, the above-mentioned multilayer structure is formed by co-extrusion or co-injection molding.

 The present invention also relates to a method for producing a multilayer structure in which a die temperature or a nozzle temperature during melt molding is 250 ° C. or higher.

 In the resin composition of the present invention, the content of the carboxylic acid (A) is 0.05 to 2.5 βΐαο 、 / g, and the content of the alkaline earth metal salt (B) is 10 ppm or less ( An ethylene-butyl alcohol copolymer (EVOH) resin composition which is a metal element conversion value and satisfies the following formula (1).

 0.7 ≤ (a l) / (A) ≤ l. 0 (1)

However,

 (A): Total content of carboxylic acid (A) and its salt moL g)

(a 1): Content of carboxylic acid (a 1) having a molecular weight of 75 or more and its salt (// mol Z g)

As the EVOH used in the present invention, those obtained by saponifying an ethylene-bi-ester copolymer are preferable, and those obtained by saponifying an ethylene-bi-butyl acetate copolymer are particularly preferable. The From the viewpoint of obtaining excellent forming shape thereof in Gasubaria properties and melt moldability, the ethylene content Ri preferably 2 0-6 5 mol% der, more preferably 2 5-5 5 mol _^0/0 , and the ones optimally 2 5-5 0 mole _^0/0 are preferred. Further, the saponification degree of the butyl acetate component is preferably at least 80%, and from the viewpoint of obtaining a molded article having excellent gas barrier properties, is more preferably at least 95%, further preferably at least 98%. Particularly preferably, it is 99%. When the ethylene content exceeds 65 mol%, there is a possibility that the barrier property, printability and the like may be insufficient. On the other hand, if the saponification degree is less than 80%, noriability, thermal stability and moisture resistance may be deteriorated. '

In addition, when copolymerizing ethylene and vinyl acetate, other fatty acid vinyl esters (such as vinyl propionate and vivalate) can also be used in combination. Also, EVOH may contain Bierushiran compound 0. 0 0 0 2 to 0.2 moles _^0/0 as a copolymer component. Here, examples of the butylsilane-based compound include vinyltrimethoxysilane, butyltriethoxysilane, vinyltri (] 3-methoxy-1-ethoxy) silane, and γ-methacryloxypropylmethoxysilane. Among them, biertrimethoxysilane and burtriethoxysilane are preferably used.

 Hereinafter, a method for producing EVOH will be specifically described. The polymerization of ethylene and butyl acetate is not limited to solution polymerization, but may be any of solution polymerization, suspension polymerization, chemical polymerization, and Balta polymerization, and may be any of continuous type and batch type. For example, the polymerization conditions for batch solution polymerization are as follows.

Solvents: alcohols are preferred, but other organic solvents (such as dimethyl sulfoxide) that can dissolve ethylene, biel acetate, and ethylene-butyl 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-1,2,4-dimethylpareronitrile), 2, Azonitrile initiators such as 2-azobis (4-methoxy-1,2,4-dimethylvaleronitrile) and 2,2-azobis (2-cyclopropylpropionitrile), etc. , Cumyl peroxy cineeodecanoate, disopropyl peroxy carbonate, di-n-propyl peroxy dicarbonate, t-butyl peroxy neo decanoate, lauper peroxide, benzoyl peroxide, t- An organic peroxide initiator such as butynole hydroperoxide can be used.

 Temperature; 20-90 ° C, preferably 40-70 ° C.

 Time; 2 to: 15 hours, preferably 3 to: 11 hours.

 Polymerization rate: 10 to 90%, preferably 30 to 80% based on the charged vinyl ester. Resin content in the solution after polymerization; 5 to 85%, preferably 20 to 70%.

Ethylene content of the copolymer; preferably 2 0-6 5 mol _^0/0, further preferably 2 5-6 0 mole percent, and optimally 2 5-5 0 mol ^_0/0.

In addition to ethylene and butyl acetate, monomers that can be copolymerized with these, for example, α-olefins such as pyrene pyrene, isobutylene, α-otaten, and a-dodecene; acrylic acid, methacrylic acid, crotonic acid, Unsaturated acids such as acid and itaconic acid, or anhydrides, salts or mono- or dialkyl esters thereof; nitriles such as atarilonitrile and methacrylonitrile; amides such as acrylyl amide and methacrylamide; ethylene Olefin sulfonic acids such as sulfonic acid, arylsulfonic acid, and metharylsulfonic acid or salts thereof; alkyl vinyl ethers, vinyl ketone, Ν-butylpyrrolidone, butyl chloride, chloridylidene, and the like coexist in small amounts. It is also possible.

 After the polymerization for a predetermined period of time, after reaching a predetermined polymerization rate, if necessary, a polymerization inhibitor is added, and the unreacted ethylene gas is removed by evaporating and removing unreacted ethylene gas. As a method of driving out unreacted vinyl acetate from the ethylene monoacetate copolymer obtained by evaporating and removing the ethylene, for example, the copolymer solution is continuously supplied at a constant rate from the upper part of a tower filled with Raschig rings. An organic solvent vapor such as methanol is blown from the bottom of the tower, and a mixed vapor of an organic solvent such as methanol and unreacted vinyl acetate is distilled out from the section of the tower, and the copolymer solution from which unreacted vinyl acetate is removed is removed from the bottom of the tower. A method is adopted.

 An alcohol catalyst is added to the copolymer solution from which unreacted vinyl acetate has been removed, and the vinyl acetate component in the copolymer is saponified. The saponification method can be either continuous or batch. Examples of the alkali catalyst include sodium hydroxide, hydroxylated lime, and alkali metal alkoxide. For example, the saponification conditions for the batch system are as follows.

 Concentration of the copolymer solution: 10 to 50%.

 Reaction temperature; 30-60 ° C.

 Amount of catalyst used: 0.02 to 0.6 equivalents (per butyl acetate component).

 Time; 1-6 hours.

 Although the degree of saponification after the saponification reaction varies depending on the purpose, it is preferably at least 80%, more preferably at least 95%, still more preferably at least 98%, particularly preferably at least 99% of the butyl acetate component. is there. The saponification degree can be arbitrarily adjusted depending on the conditions.

 Since the ethylene-butyl alcohol copolymer after the reaction contains an alkali catalyst, by-product salts, and other impurities, it is preferable to remove these by neutralizing and washing as necessary.

Examples of the carboxylic acid (A) used in the resin composition of the present invention include: saturated aliphatic carboxylic acids such as acetic acid and propionic acid; unsaturated aliphatic carboxylic acids such as oleic acid; Examples thereof include hydroxycarboxylic acids such as glycolic acid and lactic acid, and aromatic carboxylic acids such as benzoic acid. Their pKa at 25 ° C. is preferably 3.5 or more. If the pKa at 25 ° C is less than 3.5, it may be difficult to control the pH of the resin composition composed of EVOH, and the color resistance and interlayer adhesion may be unsatisfactory. . However, if the pKa is large and the strength as an acid is weak, the amount of acid used increases, resulting in cost disadvantages, and the outflow of acid components out of the system in the EVOH resin composition production process. May increase. For this reason, the upper limit of the pKa of the carboxylic acid (A) at 25 ° C. is preferably 5 or less, more preferably 4.5 or less, and still more preferably 4 or less.

 Examples of the carboxylic acid having a molecular weight of 75 or more (a1) used in the present invention include succinic acid, adipic acid, benzoic acid, acetic acid, lauric acid, glycolic acid, lactic acid and the like, and include succinic acid, adipic acid and the like. When the dicarboxylic acid of the above is used, gel-bubbles may easily occur during molding. The use of hydroxycarboxylic acids such as dalicholic acid and lactic acid does not cause the above-mentioned problems and is preferable from the viewpoint of excellent water solubility. Among them, lactic acid is particularly preferable.

 As the carboxylic acid (al) having a molecular weight of 75 or more used in the present invention, a carboxylic acid having a molecular weight of 80 or more is more preferable, a molecular weight of 85 or more is more preferable, and a molecular weight of 90 or more is particularly preferable. It is. By using a strong carboxylic acid having a high molecular weight, volatile components can be effectively reduced. Specifically, it exhibits excellent low odor and long run properties even at high temperatures such as co-extrusion molding or co-injection molding with a high melting point thermoplastic resin such as polyamide or polyester. be able to.

In particular, when lactic acid is used as the carboxylic acid (al) having a molecular weight of 75 or more, it is preferable because it has excellent water solubility as described above and has extremely low volatility as compared with acetic acid. When a pellet made of EVOH resin yarn is produced, it is usually necessary to dry the water-containing pellet, and lactic acid must be used in the drying step. As a result, the volatilization of the acid component is greatly suppressed, and a more stable quality product can be produced. Lactic acid (pKa at 25 ° C = 3.858) is a stronger acid than acetic acid (pKa at 4.75 ° C). It is possible to reduce the amount. Since it has low volatility and requires a small amount of use, it is possible to significantly reduce the outflow of acid components out of the system in the EVOH resin composition production process, thereby reducing the burden on workers. And greatly reduce the environmental impact of production facilities (such as factories).

The content of the carboxylic acid (A) in the resin composition of the present invention is 0.05 to 2.5 μϊαοΐ / g. When the content of the carboxylic acid (A) is less than 0.05 μπιοΐ / g, the coloring at the time of melting is remarkable, particularly at the time of molding at a high temperature. Also, 2.5

Even when the temperature exceeds the above range, coloring of the resin becomes remarkable during molding at a high temperature. Further, when the content of the carboxylic acid (A) is more than 2.5 zmol / g, the tangling property at the time of molding at a high temperature is significantly reduced, and the effect of improving the low odor property and the coloring resistance, and The effect of improving the adhesive force with the adhesive resin in the coextrusion molding becomes insufficient, and a sufficient long-run property cannot be obtained.

 The lower limit of the content of the carboxylic acid (A) is preferably at least 0.1 AtmolZg, and more preferably at least 0.2 fflolZg. Further, the upper limit of the content of the carboxylic acid (A) is more preferably 2 μπιοΐ / g or less, still more preferably 1. S ^ umol / g or less, and most preferably 1.0 ^ umol / g or less. g or less.

 It is optional to add a carboxylic acid (such as acetic acid) and a salt thereof having a molecular weight of less than 75 to the resin composition of the present invention as long as the effects of the present invention are not impaired. However, from the viewpoint of obtaining sufficient low odor, it is preferable that the content of the carboxylic acid having a molecular weight of less than 75 is small. Specifically, it is essential that the resin composition of the present invention satisfies the following formula (1).

 0.7 ≤ (a l) / (A) ≤ l. 0 (1)

However, (A): Total content of carboxylic acid (A) and its salts (wmol / g)

 (a 1): Content of carboxylic acid (a 1) having a molecular weight of 75 or more and its salt (zmol

/ g)

 In the above formula (1), it is essential that (al) / (A) is 0.7 or more. (A l) When Z (A) is less than 0.7, the effect of improving low-odor and long-running color resistance is insufficient. Although the resin composition of the present invention has excellent moldability at high temperatures, the tendency is particularly remarkable during melt molding at such high temperatures. (A1) NO The lower limit of (A) is more preferably 0.8 or more, particularly preferably 0.9 or more, and most preferably 0.98 or more.

 It is essential that the resin composition of the present invention has an alkaline earth metal salt (B) content of 10 ppm or less (in terms of metal element). The content of the alkaline earth metal salt (B) is more preferably 5 ppm or less (in terms of a metal element), and particularly preferably substantially no content. Such an alkaline earth metal salt (B) is not particularly limited, and examples thereof include a magnesium salt, a calcium salt, a barium salt, a beryllium salt and the like. The anion species of the alkaline earth metal salt (B) is not particularly limited, and examples thereof include aion acetate, aion lactate, and anion phosphate.

When melt molding at the normal EVOH molding temperature (around 220 ° C), such as when obtaining a laminate with polyolefin, the content of alkaline earth metal salt (B) is 10 ppm (metal element conversion). Values) tend to improve the long-run property during melt molding. However, the melting point of polyamide or polyester is high! / In the case of co-extrusion molding or co-injection molding with a thermoplastic resin, and at the time of melt molding at a high temperature where the die temperature or nozzle temperature is 250 ° C or higher, the Al-Li earth metal salt (B) If the content exceeds l Op p pm (converted to metal element), the formability will be unsatisfactory. Specifically, the state of the film surface between the EVOH and other thermoplastic resin to be laminated becomes extremely poor, and the EVOH layer is markedly colored, and the long run property is also observed. It becomes bad.

 Thus, the content of the carboxylic acid (A) is 0.05 to 2.5 ^ mol / g, and the content of the alkaline earth metal salt (B) is 10 ppm or less (in terms of metal element). The present inventors have found for the first time that the use of an ethylene-vinyl alcohol copolymer resin composition that satisfies the following formula (1) significantly improves moldability at high temperatures. From this viewpoint, the present invention is significant.

 0.7 ≤ (a 1) / (A) ≤ 1.0 (1)

However,

 (A): Total content of carboxylic acid (A) and its salt mol / g)

 (a1): Content of carboxylic acid (a1) having a molecular weight of 75 or more (a1) and a salt thereof (μπιοΐ) In the resin composition of the present invention, the content of the phosphoric acid compound (C) is 80 ppm or less (in terms of phosphate radical). Examples of the phosphate compound (C) include, but are not limited to, various acids such as phosphoric acid and phosphorous acid, and salts thereof. May be contained in any form of a first phosphate, a second phosphate, and a third phosphate, and the cation species is not particularly limited. For example, sodium dihydrogen phosphate, Examples include potassium dihydrogen phosphate, disodium hydrogen phosphate, and dihydrogen phosphate.

 Example 3 of the above-mentioned prior art (2) discloses an EVOH composition containing acetic acid, sodium acetate and potassium dihydrogen phosphate and having a calcium content of 5 ppm. However, as is clear from Comparative Example 4 of the present specification, a composition in which the carboxylic acid is composed of only acetic acid and (al) Z (A) is less than 0.7 provides a sufficiently low odor. In addition, there is still room for improvement in long-run properties during melt molding at high temperatures.

—Example 3 of this specification containing lactic acid, sodium lactate and dihydrogen phosphate phosphate, and having a content of alkaline earth metal salt of less than 10 ppm in terms of metal element. Although the low odor property was greatly improved, there was room for improvement in the long-run property during melt molding at high temperatures.

 However, as a result of intensive studies by the present inventors, the content of carboxylic acid (A) was 0.05 to 2.5 μπιοΐ / g, and the content of alkaline earth metal salt (B) was 10 ppm or less. (In terms of metal element), and in the ethylene-vinyl alcohol copolymer resin composition that satisfies the following formula (1), by setting the content of the phosphoric acid compound (C) to 8 Opm or less, It has been clarified that the long-run property at the time of melt molding at a high temperature is further improved, and the effect of the present invention can be more remarkably exhibited.

 0.7 ≤ (a 1) / (A) ≤ 1.0 (1)

 As is clear from comparison of Comparative Example 3 and Comparative Example 4 of the present specification, in the case where the sulfonic acid (A) is composed of only acetic acid, that is, when (a1) / (A) satisfies 0.7. If not, by blending the phosphoric acid conjugate (C), the long-run property is improved at the time of melt molding at a high temperature. Also, the coloring resistance is remarkably improved. However, satisfactory low odor has not been obtained. Furthermore, there was room for further improvement in long-run properties during melt molding at high temperatures.

 However, the content of the carboxylic acid (A) is 0.05 to 2.5 molZg, the content of the alkaline earth metal salt (B) is 10 ppm or less (in terms of metal element), and ( al) / In the case of the EVOH resin composition of the present invention in which (A) is 0.7 or more and 1.0 or less, there is a tendency that the long-run property is adversely reduced by the addition of the phosphoric acid compound (C). Was first discovered by the present inventors. When (al) / (A) is less than 0.7, the long run property at the time of melt molding at a high temperature is improved by adding the phosphoric acid compound (C), whereas (al) / (A) ) Is not less than 0.7 and not more than 1.0, the reason why the compound of the phosphoric acid compound (C) does not have the effect of improving the long-run property and rather tends to lower it is extremely surprising. It is a phenomenon.

From the above, in the resin yarn composition of the present invention, when melt molding at a high temperature, From the viewpoint of long running property, the upper limit of the phosphate compound (C) is preferably 80 ppm or less. Such an EVOH resin composition has excellent coloring, low unevenness on the film surface, excellent appearance and excellent odor and low odor even at the time of melt molding at a high temperature. Benefits can be obtained. The upper limit of the phosphoric compound (C) is more preferably 60 ppm or less, still more preferably 40 ppm or less, particularly preferably 20 ppm or less, and it is not substantially contained! /, That is optimal.

 The resin composition of the present invention preferably contains an alkali metal salt (D) from the viewpoint of improving adhesiveness. An example of a preferred embodiment using the EVOH resin composition of the present invention is, for example, laminating polyamide or polyester on one surface of an EVOH resin composition layer, and laminating with polyolefin or the like via an adhesive resin on the other surface. And a laminated multilayer structure. In such embodiments, it is particularly preferred that the EVOH resin composition exhibit good adhesion. From the viewpoint of a balance between adhesion and coloring resistance, particularly from the viewpoint of coloring the resin during melt molding at a high temperature, the upper limit of the content of the alkali metal salt (D) is preferably 500 ppm or less, It is more preferably less than 500 ppm, even more preferably 400 ppm or less, particularly preferably 300 ppm or less. Further, the lower limit of the content of the alkali metal salt (D) is preferably at least 10 ppm, more preferably at least 3 ppm, even more preferably at least 50 ppm. It is particularly preferred that it is p or more. Further, by blending the alkali metal salt (D), it is possible to improve the adhesive strength between the resin composition of the present invention and the adhesive resin.

The alkali metal salt (D) is not particularly limited, but preferred examples thereof include a sodium salt and a potassium salt. The aeon species of the alkali metal salt (D) is not particularly limited, but preferred examples include anion acetate, aion lactate, and anion phosphate, with aion lactate being particularly preferred. It is also preferable that the resin composition of the present invention contains the boron compound (E) in an amount of 50 to 2000 ppm in terms of a boron element. Examples of the boron compound (E) include, but are not limited to, boric acids, borate esters, borates, and borohydrides. Specifically, the boric acids include orthoboric acid, metaboric acid, tetraboric acid, and the like.The borate esters include triethyl borate, trimethyl borate, and the like. Alkali metal salts of various boric acids, alkaline earth metal salts, borax and the like. Of these compounds, orthoboric acid (hereinafter sometimes simply referred to as boric acid) is preferable.

When a boron compound is added to a resin composition composed of EVOH, the melt viscosity can be increased even when EVOH having a low degree of polymerization is used. It is possible to suppress the generation of gels and bubbles compared to EVOH, and to improve the long run property during melt molding at high temperatures, such as during co-extrusion molding or co-injection molding with a resin having a high melting point. is there. The lower limit of the content of the boron compound (E) is preferably at least 50 ppm, more preferably at least 100 ppm, and even more preferably at least 15 ppm in terms of boron element. Further, the upper limit of the content of the boron compound (E) is preferably 1500 ppm or less in terms of a boron element, and more preferably 1 OOOppm or less. If the content of the boron compound (E) is less than 50 ppm, the generation of gel and pop may increase as the molding time becomes longer. May worsen. On the other hand, if the content of the boron compound (E) exceeds 2000 ppm, there is a possibility that Görich will be chewy and the moldability will be poor. Suitable melt flow rate (MFR) of the resin composition comprising EVOH of the present invention (measured at 190 ° C under a load of 2160 g; if the melting point is around 190 ° C or exceeds 190 ° C, the load is 2160 g Below, measured at multiple temperatures above the melting point, plotted with the reciprocal of absolute temperature on the horizontal axis and the melt flow rate on the vertical axis (logarithm) in a semilogarithmic graph, 190; Is 0.:! ~ SOO gZl Omi n. It is. The lower limit of the MFR is more preferably not less than 0.2 g / l 0 min., More preferably not less than 0.5 gZl 0 min., And most preferably not less than l gZl Omin. It is. The upper limit of the MFR is more preferably 50 g / 1 Omin. Or less, still more preferably 10 g / 1 Omin. Or less, and most preferably 7 g / 10 min. Or less. If the melt flow rate is smaller than the above range, the inside of the extruder will be in a high torque state at the time of molding and extrusion processing will be difficult, and if it is larger than this range, the mechanical strength of the molded product will be insufficient. Not preferred.

 Further, the resin composition of the present invention may be blended with an ethylene-vinyl alcohol copolymer having a different degree of polymerization, an ethylene content, and a different degree of saponification within a range that does not impair the object of the present invention, and melt-molded. Is also possible. In addition, other various plasticizers, stabilizers, surfactants, coloring agents, ultraviolet absorbers, slip agents, antistatic agents, drying agents, and crosslinking agents may be added to the resin composition as long as the object of the present invention is not impaired. It is also possible to add appropriate amounts of metal salts, fillers, reinforcing agents for various fibers, and the like.

 It is also possible to mix an appropriate amount of a thermoplastic resin other than the resin composition as long as the object of the present invention is not impaired. Examples of thermoplastic resins include various polyolefins (polyethylene, polypropylene, poly 1-butene, poly 4-methylenol 1-pentene, ethylene-propylene copolymer, copolymer of ethylene and ct-olefin with 4 or more carbon atoms, polyolefin and anhydrous Copolymers with maleic acid, ethylene-polyester copolymers, ethylene-acrylate copolymers, or modified polyolefins obtained by graft-modifying these with unsaturated carboxylic acids or derivatives thereof, and various nylons (nylon 6, Nylon-6,6, Nylon-6 / 6,6 copolymer), Polychlorinated vinyl, Polyvinylidene chloride, Polyester, Polystyrene, Polyacrylonitrile, Polyurethane, Polyacetal-modified polyvinyl alcohol resin Is used.

A method in which an ethylene-butyl alcohol copolymer (EVOH) contains a carboxylic acid (A) and, if necessary, an alkali metal salt (D) and a boron compound (E). The law is not particularly limited. For example, there are a method of immersing the EVOH in a solution in which the compound is dissolved, a method of melting the EVOH and mixing the compound, a method of dissolving the EVOH in an appropriate solvent and mixing the compound, and the like. .

 Above all, in order to more remarkably exert the effects of the present invention, a method of immersing EVOH in a solution of the above compound is desirable. This processing can be performed by either the patch method or the continuous method. In this case, the shape of the EVOH may be any shape such as powder, granule, sphere, and columnar pellet.

 When the ethylene-vinyl alcohol copolymer is immersed in a solution containing the carboxylic acid (A) and, if necessary, the alkali metal salt (D) and the boron compound (E), the carboxylic acid (A) in the above solution, The respective concentrations of the alkali metal salt (D) and the boron compound (E) added as necessary are not particularly limited. The solvent of the solution is not particularly limited, but is preferably an aqueous solution for reasons of handling. The suitable range of the immersion time varies depending on the form of the ethylene-butyl alcohol copolymer, but is preferably 1 hour or more, and more preferably 2 hours or more in the case of a pellet of about 1 to 10 mm.

 The immersion treatment of the above-mentioned various compounds in a solution may be carried out by dividing into a plurality of solutions and immersion at once. Above all, it is preferable from the viewpoint of simplification of the process that the treatment is carried out with a solution containing the carboxylic acid (A), and further the alkali metal salt (D) and the boron compound (E) which are added as necessary. When the treatment is performed by immersion in the solution as described above, the final drying is performed to obtain the desired ethylene-butyl alcohol copolymer composition.

The MFR (MFR (6 min.); 270 ° C, 2160 g load) when the fat yarn composition was kept at 270 ° C for 6 minutes in the melt indexer, and 270 for 10 minutes and 20 minutes The MFR (MFR (10 min .;), MFR (20 min.), MFR (30 min.), Respectively; 270. C, 2160 g load) when held for 30 minutes is calculated by the following formulas (2) to (4 It is preferable that all of the above conditions are satisfied from the viewpoint of moldability of the resin composition. 0.5≤MFR (lOmin.) MFR (6min.) ≤1.5 (2)

 0.5≤MFR (20min.) MFR (6min.) ≤1.5 (3)

 0.5 ≤ MFR (30min.) MFR (6min.) ≤ 1.5 (4)

 Satisfying all of the above formulas (2) to (4) means that even when the heat treatment is performed at 270 ° C, which is considerably higher than the general molding temperature of EVOH, the short-term aging of MFR This indicates that the change is small. A resin composition composed of EVOH having powerful properties exhibits excellent moldability even when co-extrusion or co-injection molding is performed with a resin having a high melting point such as polyamide / polyester. Specifically, unevenness is less likely to occur at the interface between EVOH and another resin, and the resulting multilayer structure has an excellent appearance.

 In the above equations (2) to (4), MFR (lOmin.) / MFR (6min.), MFR (20min.) / MFR (6min.) And MFR (30min.) / MFR (6min.) The lower limit is more preferably 0.6 or more, and even more preferably 0.8 or more. The upper limits of MF R (lOmin.), MF R (6 min.), MFR (20 min.), Z MF R (6 min.) And MF R (30 min.) Z MFR (6 min.) Are more preferably 1. 4 or less, more preferably 1.2 or less.

 The above formulas (2) to (4) are more preferably

 0.6 ≤ MFR (lOmin.) / MF R (6min.) ≤ 1.4 (2 ')

 0.6≤MFR (20min.) MFR (6min.) ≤1.4 (3 ')

 0.6≤MFR (30min.) MFR (6min.) ≤1.4 (4 '), and more preferably,

 0.8 ≤MFR (lOmin.) MFR (6min.) ≤ 1 2 (2 ")

 0.8 ≤MFR (20min.) MFR (6min.) ≤1 2 (3 ,,)

 0.8≤MFR (30min.) / MFR (6min.) ≤2 (4 ,,).

Further, the resin composition of the present invention is a resin composition which has not been subjected to a heat treatment. FR (0)) and the resin composition heated at 220 ° C in a nitrogen atmosphere, the resin I and the MF of the resin I, 50 hours after 8 hours, 16 hours, and 24 hours from the start of heating R (respectively, MFR (8hr), MFR (16hr), MFR (24hr), MFR (50hr); all at 230 ° C, 10.9 kg load) is the total of the following formulas (5) to (8) It is preferable to satisfy

 0.02≤MFR (8hr) / MFR (0) ≤ 1 (5)

 0.02≤MFR (16hr) / MFR (0) ≤ 1 (6)

 0.02≤MFR (24hr) / MFR (0) ≤ 1 (7)

 0.02≤MFR (50hr) / MFR (0) ≤ 1 (8)

 The resin composition of the present invention is preferably subjected to co-extrusion molding or co-injection molding with a resin having a high melting point such as polyamide or polyester, and the die temperature or the nozzle temperature during molding is preferably 250 °. C or more. In order to obtain good moldability during such high-temperature molding, the change in the melting behavior of the resin composition over a long period of time at a heating temperature of 220 ° C. satisfies all of the above formulas (5) to (8). It is preferred that It is not clear why the melting behavior of the resin composition at a heating temperature of 220 ° C affects the moldability at high temperatures, but it satisfies all of the above equations (5) to (8) and increases slowly. Due to the tendency to stick, it is possible to effectively suppress the generation of gel / bubbles in the EVOH resin composition layer at the time of molding at a high temperature, and to improve the coloring resistance.

 In the above formulas (5) to (8), MFR (8hr) / MFR (0), MFR (I6hr) / MFR (0), MFR (24hr) / MFR (O), MFR (50hr) / MFR ( The lower limit of O) is more preferably 0.03, and still more preferably 0.05. Also, the upper limit of MFR (8hr) / MFR (0), MFR (I6hr) MFR (0), MFR (24hr) / MFR (O) and MFR (50hr) / MFR (0) is more preferably 0.8, and more preferably 0.6.

The above formulas (5) to (8) are more preferably 0.03≤MFR (8hr) / MFR (0) ≤ 0.8 (5 '

 0.03≤MFR (16hr) / MFR (0) ≤O. 8 (6 '

 0.03≤MFR (24hr) / MFR (0) ≤ 0.8 (7 '0.03≤MFR (50hr) / MFR (0) ≤ 0.8 (8', more preferably

 0. 05≤MFR (8hr) / MFR (0) ≤ 0.6 (5 "

 0.05≤MFR (16hr) / MFR (0) ≤ 0.6 (6 "

 0. 05≤MFR (24hr) / MFR (0) ≤ 0.6 (7 "

 0. 05 ≤ MFR (50hr) / MFR (0) ≤ 0.6 (8 ".

 The obtained resin composition of the present invention is formed into various molded articles such as films, sheets, containers, pipes, and fibers by melt molding. These molded products can be pulverized for re-use and molded again. It is also possible to uniaxially or biaxially stretch films, sheets, fibers and the like. As the melt molding method, extrusion molding, inflation extrusion, blow molding, melt spinning, injection molding and the like are possible. The melting temperature varies depending on the melting point of the copolymer and the like, but is preferably about 150 to 270 ° C.

 The resin composition of the present invention is, as described above, a multilayer structure having at least one layer of a molded product such as a composition film or sheet of the present invention, in addition to the production of a resin molded product having only a single layer of the resin composition. Often used for practical use. When the layer composition of the multilayer structure is represented by E for the resin composition of the present invention, Ad for the adhesive resin, and T for the thermoplastic resin, E / T, T / EZT, E / Ad / T, T / AdZE / Ad / T, etc., but are not limited thereto. Each layer may be a single layer or, in some cases, a multilayer.

The method for producing the above-described multilayer structure is not particularly limited. For example, a method of melt-extruding a thermoplastic resin into the molded article (film, sheet, etc.), a method of co-extruding the resin composition and another thermoplastic resin on a base material such as a thermoplastic resin, Plastic resin And a method of co-injecting a resin composition comprising EVOH and an organic titanium compound, an isocyanate compound, a polyester compound, and a molded product obtained from the resin composition of the present invention and a film or sheet of another substrate. And laminating using a known adhesive.

The thermoplastic resin used includes linear low-density polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polypropylene, and propylene- _α Polyolefins such as olefin copolymers (polyolefins having 4 to 20 carbon atoms), polybutene, polypentene, etc. alone or copolymers thereof, polyesters such as polyethylene terephthalate, polyester elastomers, nylon-16, nylon-16 And 6 etc., polystyrene, polychlorinated polyvinyl chloride, polychlorinated polyvinylidene, acrylic resin, vinyl ester resin, polyurethane elastomer, polycarbonate, chlorinated polyethylene, chlorinated polypropylene, etc. . Among them, polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-butyl acetate copolymer, polyamide, polystyrene and polyester are preferably used.

When laminating the resin composition of the present invention and a thermoplastic resin, an adhesive resin may be used, and in this case, an adhesive resin made of a carboxylic acid-modified polyolefin is preferable. Here, the carboxylic acid-modified polyolefin is a modified resin containing a carboxyl group obtained by chemically (for example, adding or grafting) an ethylenically unsaturated carboxylic acid or an anhydride thereof to an olefin polymer. This refers to an olefin polymer. Here, the olefin polymer is defined as polyethylene (low pressure, medium pressure, high pressure), linear low density polyethylene, polyolefin such as propylene, boreptene, or a comonomer capable of copolymerizing olefin and the olefin. (E.g., unsaturated carboxylic acid esters), such as ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate It means a stele copolymer or the like. Among linear low density polyethylene, ethylene monoacetate Bulle copolymer (content of acetic Bulle 5-5 5 weight ⁰ /.), Echirenaku acrylic acid Echiruesuteru copolymer (content of Akuriru acid Echiruesuteru 8-3 5 The weight is preferably ⁰ /.), And linear low-density polyethylene and ethylene monoacetate copolymer are particularly preferred. Ethylenically unsaturated carboxylic acids or anhydrides include ethylenically unsaturated monocarboxylic acids, their esters, ethylenically unsaturated dicarboxylic acids, their mono- or diesters, and their anhydrides, of which ethylenically unsaturated Dicarboxylic anhydrides are preferred. Specifically, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, monomethinoleestenole maleate, monoethynole maleate, getyl maleate, monomethyl fumarate, etc. Maleic anhydride is particularly preferred.

 The amount of addition or grafting (degree of modification) of the ethylenically unsaturated carboxylic acid or its anhydride to the olefin polymer is 0.0001 to 15% by weight, preferably 0.0%, based on the olefin polymer. 0 to 10% by weight. The addition reaction and the graft reaction of the ethylenically unsaturated carboxylic acid or its anhydride to the olefin polymer are obtained by, for example, a radical polymerization method in the presence of a solvent (such as xylene) or a catalyst (such as peroxide). Can be The melt flow rate (MFR) of the carboxylic acid-modified polyolefin thus obtained measured at 190 ° C under a load of 210 g should be 0.2 to 30 g / 10 minutes. And more preferably 0.5 to :! O g Z l O minutes. These adhesive resins may be used alone or as a mixture of two or more.

Among these embodiments, a high melting point thermoplastic resin such as polyamide or polyester and the resin composition of the present invention are bonded from the viewpoint that the effect of the present invention, which is excellent in moldability at high temperatures, can be particularly effectively exerted. An embodiment in which the layers are directly laminated without the intervention of a conductive resin or the like is preferable. Further, a high melting point thermoplastic resin such as polyamide or polyester and the resin composition of the present invention are co-extruded or co-injected to form a multilayer structure. Are particularly preferred.

 The method of coextrusion molding of the composition of the present invention and a thermoplastic resin is not particularly limited, and examples thereof include a multi-manifold merging method T-die method, a feedblock merging method T-die method, and an infusion method. Is done. The method of coinjection molding is not particularly limited, and a general method can be used. From the viewpoint that the effect of the present invention, which is excellent in moldability at high temperatures, can be particularly effectively exerted, a multilayer structure composed of the resin composition of the present invention and another thermoplastic resin is produced by co-extrusion molding or co-injection molding. In this case, it is particularly preferable to use a production method in which the die temperature or the nozzle temperature is 250 ° C. or higher. Even when co-extrusion molding or co-injection molding is performed at a high temperature, there is no unevenness at the interface between the resin composition layer made of EVOH and another thermoplastic resin layer, and the gel of the resin composition layer The present invention is also significant from the viewpoint of obtaining a multi-layer structure with good appearance and little occurrence of fuzz.

 By subjecting the co-extruded multilayer structure obtained in this way to secondary processing, various molded articles (films, sheets, tubes, bottles, etc.) can be obtained.

 (1) Multi-layer co-stretched sheet or film obtained by uniaxially or biaxially stretching or biaxially stretching a multilayer structure (such as a sheet or film) and heat-treating it.

(2) Multi-layer rolling sheet or film by rolling a multi-layer structure (sheet or film, etc.)

 (3) Multi-layered structure (sheet or film, etc.) Multi-layer tray cup-shaped container formed by thermoforming, vacuum forming, pressure forming, vacuum forming, etc.

 (4) Bottles and cup-shaped containers made by stretch blow molding from multilayer structures (pipe etc.)

 (5) Multilayer structure (such as parison) Bottle-shaped container made by biaxial stretching blow molding of force

There is no particular limitation on such a secondary processing method. Low molding etc.) can also be adopted.

 The co-extruded multilayer structure and co-injection multilayer structure obtained in this way have excellent low odor, low fish eyes, and are transparent and have few streaks, so they can be used as food container materials, such as deep drawn containers and cups. It is suitably used as a material for shaped containers and bottles. BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Hereinafter, “%” and “parts” are based on weight unless otherwise specified. The water used was ion-exchanged water.

 (1) Determination of carboxylic acid (A) content

 20 g of a dry pellet as a sample was put into 10 Oml of ion-exchanged water, and heated and extracted at 95 ° C for 6 hours. The extract was subjected to neutralization titration with 150 N NaOH using phenolphthalein as an indicator to determine the content of carboxylic acid (A).

 (2) Quantification of (a 1) / (A)

 20 g of a dry bellet as a sample was put into 100 ml of ion-exchanged water, and the mixture was heated and extracted at 95 ° C for 6 hours. Using the extract, ion chromatography was performed by ion chromatography using SCS 5-252 manufactured by Yokogawa Electric Corporation as a column and a 0.1% phosphoric acid aqueous solution as an eluent. The content was quantified to determine the total content of carboxylic acid (A) and its salt (μΐηοΐ / g), and the content of carboxylic acid (al) and its salt having a molecular weight of 75 or more (/ molZg).

 (3) Determination of Na, K, Mg, Ca ions

10 g of the dried pellet to be used as a sample was poured into 50 ml of a 0.01 N hydrochloric acid aqueous solution, and the mixture was stirred at 95 ° C for 6 hours. The aqueous solution after stirring was quantitatively analyzed using ion chromatography, and the amounts of Na, K, Mg, and Ca ions were quantified. The column used was ICS-C25 manufactured by Yokogawa Electric Corporation, and the eluent was an aqueous solution containing 5.0 mM tartaric acid and 1.0 mM 2,6-pyridinedicarboxylic acid. When quantifying, Calibration curves prepared with an aqueous sodium chloride solution, an aqueous solution of sodium chloride, an aqueous solution of magnesium chloride and an aqueous solution of calcium salt were used, respectively. From the amounts of Na, K, Mg, and Ca ions thus obtained, the amounts of the alkaline earth metal salt (B) and the alkali metal salt (D) in the dried pellets were obtained in terms of metal element.

 (4) Determination of phosphate ion

 10 g of a dry velvet as a sample was poured into 50 ml of a 0.01 N aqueous hydrochloric acid solution, and the mixture was stirred at 95 ° C for 6 hours. The aqueous solution after stirring was quantitatively analyzed using ion chromatography to determine the amount of phosphate ions. The column used was ICS-A23 manufactured by Yokogawa Electric Corporation, and the eluent was an aqueous solution containing 2.5 mM sodium carbonate and 1.0 mM sodium hydrogen carbonate. For the determination, a calibration curve prepared with an aqueous solution of sodium dihydrogen phosphate was used. From the amount of phosphate ions thus obtained, the content of the phosphate compound (C) was obtained in terms of phosphate groups.

 (5) Determination of boron compound (E)

 100 g of a dry pellet as a sample was placed in a magnetic crucible and ashed in an electric furnace. The obtained ash was dissolved in 20 OmL of a 0.01 N aqueous nitric acid solution and quantified by atomic absorption spectrometry, and the content of the boron compound (E) was obtained in terms of elemental boron.

 (6) Intrinsic viscosity

 0.20 g of a sample pellet of a resin composition composed of EVOH was precisely weighed, and this was hydrated with phenol (water Z-phenol = 15/85 wt%) at 40 ° C at 60 ° C for 3 to 3 ° C. The mixture was heated and melted for 4 hours, and measured with an Ostwald viscometer at a temperature of 30 ° C. (t 0 = 90 seconds).

[η] = (2 X (77 SP- 1 η ηΐβΐ)) ^1/2 / C (1 / g)

 7] sp = t / t O— l (specific viscosity)

 77 rel = tZ t 0 (relative viscosity)

 C: EVOH concentration (g / 1)

• t O: Time for blank (hydrous phenol) to pass through viscometer -t: Time when the aqueous phenol solution in which the sample is dissolved passes through the viscometer

(7) Relationship between heating time and MFR (1): 2 Melting behavior at 70 ° C

 Put 5 g of the dried pellet as a sample into the melt indexer, hold it at 270 ° C under a load of 2160 kg for 6 minutes, and then weigh the resin discharged from the melt indexer per minute. Was measured for 3 minutes. That is, the discharge amount for 6 to 7 minutes, the discharge amount for 7 to 8 minutes, and the discharge amount for 8 to 9 minutes from the start of heating were measured, and the average value was obtained. The average value of the obtained discharge amount per minute was multiplied by 10 to obtain the MFR (MFR (6 min.)) At a retention time of 6 minutes (n = 3).

 Using the same measurement method as above, the MFR (MFR (20 min.)) For a retention time of 10 minutes, the MFR (MFR (20 min.)) For 20 minutes, and the MFR (MFR (30 min.)) For 30 minutes ).

 • Judgment

It was determined according to the following criteria.

 〇: MFR (lOmin.) / MFR (6min.), MFR (20min.) / MFR (6min.) And MFR (30min.) ZMFR (6min. Included in the range.

X: At least one of MFR (lOmin.) / MFR (6rain.), MFR (20min.) / MFR (6rain.) And MFR (30min.) / MFR (6min.) Is 0.5 to: I Not included in range 5.

 (8) Relationship between heating time and MFR (2): Melting behavior at 220 ° C

5 g of a dry pellet as a sample was placed in a stainless steel metal container under a nitrogen atmosphere and sealed. This sample container was heated at 220 ° C. The MFR of the resin composition at the heat treatment time of 8, 16, 24, and 50 hours was measured at 230 ° C under a load of 10.9 kg, and the MFR (8 hr) and MF R (16 hr), MFR (24 hr) and MFR (50 hr) (n = 3). The MFR of the resin not subjected to the heat treatment was measured at 230 ° C. under a load of 10.9 kg, and was determined as MFR (0) (n = 3). Based on the obtained measurement results, the following judgment was made.

〇: MFR (8hr) / MFR (0), MFR (16hr) / MFR (0), MFR (24hr) / MFR (0) and MFR (50hr) ZMFR (0) are all in the range of 0.02 to 1. Included in the box.

X: at least one of MFR (8hr) / MFR (0), MFR (16hr) / MFR (0), MFR (24hr) / MFR (0) and MFR (50hr) / MFR (0) is 0.02 Not included in the range of ~ 1.

 (9) Multi-layer film forming test

Using the obtained dried chips and a polyamide resin [Ube Nylon 1024 F DX41] manufactured by Ube Industries, a two-layer, three-layer multilayer film (polyamide ZEV OH / polyamide)

Ο / ζΖΐ Ο / ζ) were prepared and evaluated for color resistance, film surface unevenness and appearance.

The specifications of the extruder and die used in this test and the extrusion temperature are as follows. Extruder for EVOH; 20 φ extruder Laboratory machine ME type CO—ΕΧΤ (Toyo Seiki) Extruder for polyamide; 25 φ extruder P 25-18 AC (Osaka Seiki)

T die; 300 arm width coat hanger die (Plastic Engineering Laboratory)

EVOH extrusion temperature;

 C 1 / C 2 / C 3 / die = 180/220/220/260 ° C

Polyamide extrusion temperature;

 C 1 / C 2 / C 3 / die = 230/240/260/260 ° C

 (9-1a) Unevenness of membrane surface

 The state of the interface between the EVOH layer and the polyamide layer of the multilayer film produced by the above method was visually observed and determined as follows.

 A; good B; slight unevenness of film surface C: severe unevenness of film surface

 (9-b) Coloring resistance

The multilayer film produced by the above method is wound around a paper tube, Was visually determined and determined as follows.

A; no coloring B; slightly yellowing C; yellowing D; intense coloring

 (9-1c) Long run

 Eight hours after the start of multilayer film formation, the film was sampled, the polyimide layer was swollen with trifluoroethanol, peeled off, and only the EVOH layer was taken out. The gel-like bulk in the EVOH layer (approximately 100 μπι visible to the naked eye) Above).

The number of the puts was converted into the number per 1. Om ² and determined as follows.

 A: less than 20 B; 20 to 40 C; 40 to 60 D; 60 or more (10) Odor

Samples Peretsuto 20 ₈ of a resin composition composed of EVOH placed in 100 ₁ 111 glass sample tube, after the mouth was covered with aluminum foil and heated 9 0 min 0.99 ° C in a hot air dryer. After taking it out of the dryer and allowing it to cool at room temperature for 1 hour, the sample tube was shaken 2-3 times, then the lid of the aluminum foil was removed and the odor was evaluated. The odor intensity of the sample pellet was determined based on the following criteria.

A: no odor B; weak odor C; obvious odor D; fairly strong odor

They were charged 45% methanol solution of ethylene monoacetate Bulle copolymer ethylene content 38 mole _^0/0 to saponification reactor, acetic Bulle component of sodium hydroxide / methanol solution (80 g / "L) copolymer Of the copolymer was adjusted to 0.4 equivalents, and methanol was added to adjust the copolymer concentration to 20%, while the temperature was raised to 60 ° C and nitrogen gas was blown into the reactor. After 4 hours, the reaction was neutralized with acetic acid to stop the reaction, extruded out of a metal plate with a circular opening into water and precipitated, and cut to obtain a diameter of about 3 mm and a length of about 3 mm. A 5 mm chip was obtained, and the obtained chip was washed with 1 g ZL of an aqueous acetic acid solution, and the operation of adding a large amount of water and removing water was repeated, and the obtained EVOH chip had a water content of 110%. (Dry base).

The EVOH thus obtained (ethylene content 38 mol%, saponification degree 99.4%, 10 kg of a water-containing chip having an intrinsic viscosity of 0.085 1 / g) was immersed in 18 L of an aqueous solution containing 0.53 g / L of boric acid at 25 ° C for 5 hours, and then immersed.

 Further, 3.3 kg of the above hydrated chip was immersed and stirred in 30 L of an aqueous solution containing 0.13 g ZL of boric acid, 0.46 g / L of lactic acid, and 0.855 g of sodium lactate for 25 hours at 25. Thereafter, the solution was drained and dried with hot air at 80 ° C. for 3 hours and at 107 ° C. for 24 hours to obtain a dry chip.

 The content of carboxylic acid (A) in the obtained dried chips is 0.33 / zmolZg, and the total content of carboxylic acid (A) and its salt is 7.9 μΐηο 1 / g (molecular weight in The content of 75 or more carboxylic acids (a 1) and its salts is 7.9 μταο 1 / g), the content of metal salts is 20 ppm in terms of metal elements, and the content of boron compounds is boron elements The converted value was 280 ppm. MFR is 1.7 gZl O

(190 ° C, 2160 g load).

The obtained dried chips were held in a melt indexer at 270 ° C, and the MFR (270 ° C, 2160 ° C) of each of the resin compositions at a holding time of 6 minutes, 10 minutes, 20 minutes, and 30 minutes. g load) was measured. The measurement results are shown below and are also shown in Figure 1. FIG. 1 is a graph showing the relationship between the heating time and the MFR (270 ° C, 2160 g load) when the resin composition composed of EVOH is maintained at 270 ° C in a melt indexer.

 MFR (6min.) = 10.lg / 1 0min

 MFRdOmin.) = 8.9 g / 10 min

 (MFR (lOmin.) / MFR (6min.) = 0.88)

 MFR (20rain.) = 9.4 g / l 0 min

 (MFR (20min.) / MFR (6min.) = 0.93)

 MFR (30min.) = 1 1.8 g / l 0min

 (MFR (30min.) / MFR (6min.) = 1.17)

The obtained dried chips were placed in a stainless steel metal container under a nitrogen atmosphere and sealed. When this sample container was heated at 220 ° C for 8, 16, 24, and 50 hours, the MFR of each resin composition and the MFR (MFR (0) ) Was measured. The measurement results are shown below and are also shown in Figure 2. Figure 2 shows the relationship between heating time and MFR (230 ° C, 10.9 kg load) when the resin composition composed of EVOH was kept at 220 ° C in a nitrogen atmosphere.

 MFR (0) = 40 gZl 0 min

 MFR (8hr) = 12 gZl O min

 (MFR (8hr) / MFR (0) = O. 30)

 MFR (16hr) = l l gZl O min

 (MFR (I6hr) / MFR (0) = 0.28)

 MFR (24hr) = 10 gZl 0 min

 (MFR (24hr) / MFR (0) = O. 25)

 MFR (50hr) = 9 g / l 0 min

 (MFR (50hr) /MFR(0)-0.23)

 Using the obtained dried chips and polyamide resin [Ube Nylon 1024F DX41] manufactured by Ube Industries, two or three layers of polyamide ZEVOH no-polyamide are formed according to the above method, and the film surface unevenness, coloring resistance and Long run test was conducted. The resulting multilayer film was evaluated as A for both the unevenness of the film surface, the degree of coloring of the end surface, and the long run property.

 Using the obtained dried chips, an odor test was conducted in accordance with the above method. The odor test result was A.

Example 2

Ethylene content 38 mole _^0/0, saponification degree 99.4%, intrinsic viscosity 0. 112 lZg of water-containing EVOH chips (water content 110%: dry basis) using a liquid immersing the hydrous EV OH chip A dried pellet was prepared in the same manner as in Example 1 except that the composition was changed as shown in Table 1, and evaluation was performed in the same manner as in Example 1. Table 3 shows the evaluation results.

Examples 3 to 5

 Using the water-containing EVOH chip obtained in Example 1 before immersion treatment (ethylene content 38 mol%, saponification degree 99.4%, intrinsic viscosity 0.085 1 / g), the water-containing EVOH chip is immersed A dried pellet was prepared in the same manner as in Example 1 except that the composition of the solution to be used was changed as shown in Table 1, and evaluation was performed in the same manner as in Example 1. Table 3 shows the evaluation results.

Example 6

Ethylene content ₃ 2 mole ⁰ /. Table 1 shows the composition of the liquid used to immerse the water-containing EVOH chip using a water-containing chip of EVOH (water content: 110%: dry base) with a saponification degree of 99.5% and an intrinsic viscosity of 0.097 lZg. A dried pellet was prepared in the same manner as in Example 1 except that the composition was changed to, and the evaluation was performed in the same manner as in Example 1. Table 3 shows the evaluation results.

Comparative Example 1

 Using the water-containing EVOH chip obtained in Example 1 before immersion treatment (ethylene content 38 mol%, saponification degree 99.4%, intrinsic viscosity 0.085 1 / g), the water-containing EVOH chip is immersed A dried pellet was produced in the same manner as in Example 1 except that the composition of the solution to be used was changed as shown in Table 1.

 The obtained dried chips are held in a melt indexer at 270 ° C., and the MFR (270 ° C., 2160 g load) of each resin composition at the holding time of 6, 10, 20, and 30 minutes Was measured. The measurement results are shown below and are also shown in Figure 1.

 MFR (6min.) = 10.l gZl O min

 MFR (lOmin.) = 8.5 g / l 0 min

 (MFR (lOmin.) / MFR (6min.) = 0.84)

MFR (20min.) = 9.O g no 10min (MFR (20rain.) / MFR (6min.) = 0.89)

 MFR (30min.) = 10.8 g / l 0min

 (MFR (30min.) / MFR (6min.) = 1.07)

 The obtained dried chips were placed in a stainless steel metal container under a nitrogen atmosphere and sealed. The MFR when this sample container was heated at 220 ° C for 8, 16, 24, and 50 hours and the MFR (MFR (O)) of the resin not subjected to the heat treatment were measured. The measurement results are shown below and are also shown in Figure 2.

 MFR (O) = 35.2 g / 10min

 MFR (8hr) = 10.l g / 10min

 (MFR (8hr) / MFR (0) = O. 29)

 MFR (I6hr) = 5.7 g / 10min

 (MFR (I6hr) / MFR (0) = O. 16)

 MFR (24hr) = 3.5 g / l 0 min

 (MFR (24hr) / MFR (0) = O. 10)

 MFR (50hr) = 0.35 g / 10min

 (MFR (50hr) / MFR (0) = O. 01)

 The same evaluation as in Example 1 was performed using the obtained dried chips. Table 3 shows the evaluation results. '

Comparative Example 2

Using hydrous EVOH chips before immersion treatment obtained in Example 2 (ethylene content 38 molar _^0/0, saponification degree 99.4%, intrinsic viscosity 0. 1 12 1 / g), the water EV OH A dried bellet was produced in the same manner as in Example 1 except that the composition of the liquid in which the chip was immersed was changed as shown in Table 1.

The obtained dried chips are held in a melt indexer at 270 ° C., and the MFR (270 ° C., 2160 g load) of each resin composition at the holding time of 6, 10, 20, and 30 minutes is measured. It was measured. The measurement results are as follows, which is also shown in Figure 1. Show.

 MFR (6rain.) = 14. O gZl O min

 MFRdOmin.) = 31.2 g / 10min

 (MFR (lOmin.) / MFR (6min.) = 2.23)

 MFR (20 min.) = 101 gZl 0 min

 (MFR (20min.) / MFR (6min.) = 7.21)

 MFR (30 min.) = 105 g / 10 min

 (MFR (30min.) / MFR (6min.) = 7.50)

 The obtained dried chips were placed in a stainless steel metal container under a nitrogen atmosphere and sealed. The MFR when the sample container was heated at 220 for 8, 16, 24, and 50 hours and the MFR (MFR (O)) of the resin not subjected to the heat treatment were as follows. The measurement results are shown below and are also shown in Figure 2.

 MFR (O) = 40. O gZl O min

 MFR (8hr) = 70.l gZl O min

 (MFR (8hr) / MFR (0) = 1.75)

 MFR (16hr) l O l gZl O min

 (MFR (8hr) / MFR (0) = 2.53)

 MFR (24hr) = 124gZl O min

 (MFR (lOhr) / MFR (0) = 3.10)

 MFR (50hr) = 42.4 gZl O min

 (MFR (50hr) / MFR (0) = 1.06)

 The same evaluation as in Example 1 was performed using the obtained dried chips. Table 3 shows the evaluation results.

Comparative Example 3

Using the water-containing EVOH chip (ethylene content 38 mol%, saponification degree 99.4%, intrinsic viscosity 0.085 1 / g) obtained in Example 1 before immersion treatment, 10 kg of the OH chip was immersed in 18 L of an aqueous solution containing 0.53 g / L of boric acid at 25 ° C for 5 hours.

 Further, 3.3 kg of the above hydrated chip is immersed in 30 L of an aqueous solution containing 0.13 g / L of boric acid, 0.3 g / L of acetic acid, and 0.54 g / L of sodium acetate at 25 ° C for 6 hours with stirring. did. Thereafter, the solution was drained and dried with hot air at 80 ° C for 3 hours and at 107 ° C for 24 hours to obtain dried chips.

 The content of carboxylic acid (A) in the obtained dried chips was 2.2 μϊΆθ 1 / g, and the total content of carboxylic acid (A) and its salts was 5.5 mo 1 / g (of which The content of carboxylic acid (al) with a molecular weight of 75 or more (al) and its salt is 0 μπιο1 Zg), the content of alkali metal salt is 200 ppm in metal element conversion, and the content of boron compound is boron element conversion value At 280 ppm. The MFR was 1.9 gZlO content (190 ° C, 2160 g load).

 The same evaluation as in Example 1 was performed using the obtained dried chips. Table 3 shows the evaluation results.

Comparative Example 4

Using the water-containing EVOH chip obtained in Example 1 before immersion treatment (ethylene content 38 mol%, saponification degree 99.4%, intrinsic viscosity 0.085 1 / g), the water-containing EVOH chip was immersed. A dried pellet was prepared in the same manner as in Example 1 except that the composition of the solution to be used was changed as shown in Table 1, and evaluation was performed in the same manner as in Example 1. Table 3 shows the evaluation results. table 1

* X / Y (g / L): X is the concentration of aqueous solution containing only boric acid, Y is the concentration of aqueous solution containing boric acid and metal salt

Table 2

Table 3

 * 3

 O: MFR (10min.) / MFR (6min.), MFR (20min.) / MFR (6min.), FR (30min.) / FR (6min.) All fall within the range of 0.5 to 1.5.

X: MFR (10min.) / MFR (6min.) _{S At least one of} MFR (20min.) / MFR (6min.), MFR (30min.) / MFR (6min.) Does not fall in the range of 0.5 to 1.5 .

 * Four

 O; MFR (8hr) / MFR (0), MFR (16hr) / MFR (0), MFR (24hr) / FR (0), MFR (50hr) / FR (0) all within the range of 0.02 ~ 1 enter.

X: at least any of MFR (8hr) / MFR (0), MFR (16hr) / MFR (0), MFR (24hr) / FR (0), MFR (50hr) / MFR (0) is 0 ² to 1 Out of range. The resin compositions comprising EVOH of Examples 1 to 6 having the constitution of the present invention

!

Even at the time of co-extrusion molding with the resin at high temperature, it was possible to obtain a molded article excellent in appearance with less unevenness of the film surface and less coloring and less generation of gel and pop. As compared with Example 1, in Example 2, which did not contain a boron compound, the long-run property during multilayer film formation was slightly inferior. In Example 3 in which the content of the phosphoric acid compound (C) exceeds 80 ppm (in terms of phosphate radical), the long-run property was further reduced.

 In Example 4 in which the content of the alkali metal salt (D) was more than 30 Oppm (in terms of metal element), the surface of the film was slightly uneven at the time of multilayer film formation, and the color resistance and the long run property were slightly inferior. .

 Also, Example 5 in which (& 1) da () is less than 0.98 (provided that (A): the total content of carboxylic acid (A) and its salts (μπιοΐ / g), (a 1): The content of the carboxylic acid (a1) having a molecular weight of 75 or more (a1) and its salt (mol / g)) was slightly inferior in the effect of improving the low odor.

 On the other hand, in Comparative Example 1 in which the content of the carboxylic acid was more than 2.5 / molZg, the long run property and the coloring resistance during the multilayer film formation were remarkably inferior. In Comparative Example 2 in which the content of the alkaline earth metal salt (B) exceeds l Op pm (converted to a metal element), severe film surface unevenness occurs during coextrusion molding with polyamide, and the color resistance is remarkably high. Dropped.

 Further, in the case of Comparative Example 3 in which (a 1) / (A) is less than 0.7, a sufficient effect of improving coloration resistance cannot be obtained at the time of coextrusion molding with polyamide and an effect of improving odor. No fruit was obtained. In Comparative Example 4 in which (a 1) / (A) was less than 0.7, but the phosphoric acid compound (C) was blended, the coloring resistance was improved, but the effect of improving the odor was not improved. It was still scarce.

Industrial applicability According to the present invention, even when co-extrusion molding or co-injection molding with a resin having a high melting point such as polyamide or polyester, coloring, film surface unevenness is excellent, appearance is excellent, and long-running is achieved even during high-temperature melt molding. The present invention can provide an ethylene-vinyl alcohol copolymer resin composition having excellent properties and low odor, and a multilayer structure using the same.

 The multilayer structure of the present invention is useful as various food containers, for example, deep drawing containers, cup-shaped containers, bottles and the like.

Claims

The scope of the claims

1. The content of the carboxylic acid (A) is 0.05 to 2.5 μηιο1 / _§ , the content of the alkaline earth metal salt (Β) is 10 ppm or less (in terms of metal element), and An ethylene-butyl alcohol copolymer resin composition satisfying the following formula (1).

 0.7 ≤ (a l) / (A) ≤ l. 0 (1)

However,

 (A): Total content of carboxylic acid (A) and its salt (imolZg)

 (a 1): Content of carboxylic acid with molecular weight of 75 or more (a 1) and its salt (μιηοΐ / g)

 2. The resin composition according to claim 1, which is a carboxylic acid (al) I hydroxycarboxylic acid having a molecular weight of 75 or more.

 3. The resin yarn composition according to claim 1, wherein the carboxylic acid (a1) having a molecular weight of 75 or more is lactic acid.

4. Claims in which the content of the phosphate compound (C) is 80 ppm or less (converted to phosphate radical):! 4. The resin composition according to any one of items 1 to 3.

 5. The resin composition according to claim 1, which contains the boron compound (E) in an amount of 50 to 2,000 ppm in terms of a boron element.

 6. MFR (MFR (6min.); 270 ° C, 2160g load) when the resin composition is held at 270 ° C for 6 minutes in the melt indexer, and 270 for 10 minutes, 20 minutes, 30 The MFR (MFR (10 min.), MFR (20 min.), MFR (30 min.); All at 270 ° C and 2160 g load) when held for minutes is calculated by the following formulas (2) to (4). The resin composition according to any one of claims 1 to 5, which satisfies the following.

 0.5≤MFR (lOmin.) / MFR (6min.) ≤1.5 (2)

 0.5≤MFR (20min.) / MFR (6min.) ≤1.5 (3)

0.5≤MFR (30min.) / MFR (6min.) ≤1.5 (4)

7. A multilayer structure comprising a layer made of the resin composition according to any one of claims 1 to 6 and a thermoplastic resin laminated on at least one surface of the layer.

 8. The multilayer structure according to claim 7, wherein the thermoplastic resin is polyamide or polyester.

 9. The multilayer structure according to claim 7 or 8, which is formed by co-extrusion molding or co-injection molding.

10. The method for producing a multilayer structure according to claim 7, wherein a die temperature or a nozzle temperature during melt molding is 250 ° C. or higher.