阅读说明：本技术 树脂组合物、其制造方法和使用了其的成形体 (Resin composition, method for producing same, and molded article using same ) 是由 片平英里子 下浩幸 中野贤治 于 2018-03-14 设计创作，主要内容包括：树脂组合物,其为含有乙烯-乙烯醇共聚物和非离子表面活性剂的树脂组合物,上述乙烯-乙烯醇共聚物的乙烯单元含量为15~60摩尔%、皂化度为90摩尔%以上,所述树脂组合物中含有上述乙烯-乙烯醇共聚物作为主成分,且含有3~400ppm的上述非离子表面活性剂。此外,通过将包含非离子表面活性剂、水和上述乙烯-乙烯醇共聚物的混合物进行熔融混炼而制造上述树脂组合物。通过使用这样得到的树脂组合物,从而使熔融成形时的喷出量增加,且能够获得外观优异的成形体。(A resin composition comprising an ethylene-vinyl alcohol copolymer and a nonionic surfactant, wherein the ethylene unit content of the ethylene-vinyl alcohol copolymer is 15 ~ 60 mol% and the degree of saponification is 90 mol% or more, the resin composition comprising the ethylene-vinyl alcohol copolymer as a main component and 3 ~ 400ppm of the nonionic surfactant, and wherein the resin composition is produced by melt-kneading a mixture comprising the nonionic surfactant, water and the ethylene-vinyl alcohol copolymer.)

1. A resin composition comprising an ethylene-vinyl alcohol copolymer and a nonionic surfactant,

the ethylene-vinyl alcohol copolymer has an ethylene unit content of 15 ~ 60 mol% and a saponification degree of 90 mol% or more,

the resin composition contains the ethylene-vinyl alcohol copolymer as a main component,

and contains 3 ~ 400ppm of the nonionic surfactant.

2. The resin composition according to claim 1, wherein the nonionic surfactant is at least one selected from the group consisting of an ether type, an amino ether type, an ester seed type and an amide type.

3. The resin composition according to claim 2, wherein the nonionic surfactant is at least one selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyethylene styrenated phenyl ethers, polyoxyalkylene alkylamines, polyoxyalkylene alkenylamines, polyoxyalkylene alkyl esters, polyoxyalkylene alkenyl esters, sorbitan alkyl esters, sorbitan alkenyl esters, polyoxyethylene sorbitan alkyl esters, polyoxyethylene sorbitan alkenyl esters, glycerin alkyl esters, glycerin alkenyl esters, polyglycerin alkyl esters, polyglycerin alkenyl esters, and higher fatty acid amides.

4. The resin composition of any one of claims 1 ~ 3, further comprising 10 ~ 500ppm of an alkali metal salt in terms of metal elements.

5. The resin composition according to any one of claims 1 ~ 4, further containing 0.005 ~ 1% by mass of at least 1 additive selected from the group consisting of an antioxidant, an ultraviolet absorber, a plasticizer, an antistatic agent, a lubricant, and a filler.

6. The resin composition according to claim 1 ~ 5, wherein the ethylene-vinyl alcohol copolymer contains 2 ethylene-vinyl alcohol copolymers having different ethylene unit contents.

7. A molded article comprising the resin composition according to claim 1 ~ 6.

8. A multilayer structure having:

a layer comprising the resin composition of any one of claim 1 ~ 6, and

a layer comprising a thermoplastic resin other than the ethylene-vinyl alcohol copolymer.

9. The method for producing a resin composition according to claim 1 ~ 6, wherein a mixture containing the nonionic surfactant, water, and the ethylene-vinyl alcohol copolymer is melt-kneaded.

10. The production method according to claim 9, wherein the content of water in the mixture is 0.1 ~ 50 parts by mass with respect to 100 parts by mass of the ethylene-vinyl alcohol copolymer.

11. The production method according to claim 9 or 10, wherein the mixture is obtained by adding an aqueous solution or an aqueous dispersion containing the nonionic surfactant to the ethylene-vinyl alcohol copolymer.

Technical Field

The present invention relates to a resin composition containing an ethylene-vinyl alcohol copolymer, a method for producing the same, and a molded article using the same.

Background

An ethylene-vinyl alcohol copolymer (hereinafter, sometimes abbreviated as "EVOH") is a polymer material excellent in barrier properties against gases such as oxygen, transparency, aroma retention, oil resistance, non-charging properties, mechanical strength, and the like. Therefore, EVOH is used in a wide range of applications as a material for molded articles such as containers. Molded articles using EVOH are generally produced by a melt molding method. Therefore, EVOH is required to have an excellent appearance (no coloration such as yellowing) after melt molding, and the like, as well as to improve productivity during melt molding.

Patent document 1 proposes a resin composition containing EVOH, hydrotalcite, and a metal salt of a higher fatty acid. It is said that: according to the resin composition, not only the discharge amount during melt molding is increased and the production efficiency is improved, but also a molded product such as a film with good quality, which is less in lumps and fish eyes, can be obtained. However, a molded article obtained by melt molding the resin composition may be colored and may cause a problem.

Patent documents 2 and 3 propose various resin compositions in which EVOH contains an acid such as a carboxylic acid or a phosphoric acid, and a metal salt such as an alkali metal salt or an alkaline earth metal salt. Further, patent documents 2 and 3 describe that these resin compositions are excellent in appearance and stability during melt molding. However, these resin compositions may have insufficient productivity in melt molding.

Patent document 4 describes a packaging bag for vegetables and fruits comprising an EVOH film containing 0.3 wt% or more of a surfactant. Patent document 4 describes that condensation in a package of vegetables and fruits can be eliminated by using EVOH in combination with a surfactant, but the vegetables and fruits are not wilted. However, in the case of producing the packaging bag for vegetables and fruits described in patent document 4, the productivity at the time of melt molding is insufficient, and the appearance of the molded article obtained by melt molding is also poor.

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made to solve the above problems, and an object thereof is to provide a resin composition which has a large discharge amount during melt molding and can provide a molded article having an excellent appearance, and a method for producing the same. It is another object of the present invention to provide a molded article and a multilayer structure obtained using the resin composition.

Means for solving the problems

The above object is achieved by providing a resin composition comprising an ethylene-vinyl alcohol copolymer and a nonionic surfactant, wherein the ethylene-vinyl alcohol copolymer has an ethylene unit content of 15 ~ 60 mol% and a saponification degree of 90 mol% or more, and the resin composition contains the ethylene-vinyl alcohol copolymer as a main component and 3 ~ 400ppm of the nonionic surfactant.

The nonionic surfactant is preferably at least one selected from the group consisting of ether type, amino ether type, ester seed type, and amide type. The nonionic surfactant is more preferably at least one selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyethylene styrenated phenyl ethers, polyoxyalkylene alkylamines, polyoxyalkylene alkenylamines, polyoxyalkylene alkyl esters, polyoxyalkylene alkenyl esters, sorbitan alkyl esters, sorbitan alkenyl esters, polyoxyethylene sorbitan alkyl esters, polyoxyethylene sorbitan alkenyl esters, glycerin alkyl esters, glycerin alkenyl esters, polyglycerin alkyl esters, polyglycerin alkenyl esters, and higher fatty acid amides.

The resin composition preferably further contains 10 ~ 500ppm of an alkali metal salt in terms of metal element.

The resin composition preferably further contains 0.005 ~ 1 mass% of at least 1 additive selected from the group consisting of an antioxidant, an ultraviolet absorber, a plasticizer, an antistatic agent, a lubricant, and a filler.

The above resin composition is preferably: the EVOH contains 2 kinds of EVOH having different ethylene unit contents.

The molded article containing the resin composition is a preferred embodiment of the present invention. A multilayer structure having a layer comprising the above resin composition and a layer comprising a thermoplastic resin other than the EVOH described above is also a preferred embodiment of the present invention.

The above problem can also be solved by providing a method for producing the resin composition, wherein a mixture containing the nonionic surfactant, water and the EVOH is melt-kneaded, and in this case, the content of water in the mixture is preferably 0.1 ~ 50 parts by mass per 100 parts by mass of the EVOH, and it is preferable that an aqueous solution or an aqueous dispersion containing the nonionic surfactant is added to the EVOH to obtain the mixture.

ADVANTAGEOUS EFFECTS OF INVENTION

The resin composition of the present invention is excellent in appearance. By using the resin composition, the discharge amount during melt molding is increased. In particular, a constant discharge amount can be ensured even at low temperatures. By using such a resin composition, a molded body and a multilayer structure having excellent appearance can be produced with good productivity. Further, according to the production method of the present invention, the resin composition can be produced easily.

Detailed Description

The resin composition, the molded article, and the multilayer structure of the present invention will be described in detail below.

[ resin composition ]

The resin composition of the present invention comprises an ethylene-vinyl alcohol copolymer having an ethylene unit content of 15 ~ 60 mol% and a degree of saponification of 90 mol% or more, and a nonionic surfactant in an amount of 3 ~ 400ppm, wherein the ethylene-vinyl alcohol copolymer is contained as a main component.

（EVOH）

The EVOH contained in the resin composition of the present invention is a copolymer containing an ethylene unit and a vinyl alcohol unit. The EVOH can be produced by a known method. For example, the EVOH can be obtained by copolymerizing ethylene and a vinyl ester to obtain an ethylene-vinyl ester copolymer, and then saponifying the copolymer using an alkali catalyst or the like. Examples of the vinyl ester include vinyl esters of fatty acids such as vinyl acetate, vinyl propionate, and vinyl pivalate, and vinyl acetate is preferred. The EVOH may contain a copolymerizable component other than ethylene and vinyl alcohol within a range not impairing the effects of the present invention. Examples of such other copolymerizable component include units derived from a vinyl silane compound. Examples of the unit derived from the vinyl silane compound include units derived from vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (. beta. -methoxy-ethoxy) silane or γ -methacryloxypropylmethoxysilane. Among these, units derived from vinyltrimethoxysilane or vinyltriethoxysilane are preferred. Furthermore, the EVOH may contain an α -olefin derived from propylene, butene, or the like; unsaturated carboxylic acids such as (meth) acrylic acid and methyl (meth) acrylate, or esters thereof; and a unit of vinylpyrrolidone such as N-vinylpyrrolidone as another copolymerization component. The content of the copolymerizable component other than the ethylene unit and the vinyl alcohol unit in the EVOH is preferably 10 mol% or less, more preferably 5 mol% or less, and still more preferably 1 mol% or less.

The EVOH has an ethylene unit content of 15 ~ 60 mol% as a necessary factor, and therefore, a resin composition having both excellent melt moldability and gas barrier property can be obtained, and when the ethylene content is less than 15 mol%, the long-term run stability at the time of melt molding of the resin composition is lowered, and the water resistance, hot water resistance, and gas barrier property under high humidity of the obtained molded article are also lowered, and on the other hand, when the ethylene content exceeds 60 mol%, the gas barrier property of the obtained molded article is lowered, and preferably, the ethylene content is 50 mol% or less.

The saponification degree of the EVOH must be 90 mol% or more. Thereby, a resin composition having excellent gas barrier properties can be obtained. When the saponification degree is less than 90 mol%, the gas barrier property of the resulting molded article is lowered and the appearance is deteriorated. The saponification degree is preferably 95 mol% or more, and more preferably 99 mol% or more. The ethylene unit content and the degree of saponification of the EVOH can be improved by using DMSO-d in a solvent₆Is/are as follows¹H-NMR measurement.

The melt flow rate (temperature 210 ℃, load 2160g, hereinafter abbreviated as MFR) of the EVOH is preferably 0.1 ~ g/10 min, and when the MFR of the EVOH is within this range, the moldability and processability of the resin composition and the appearance of the molded article obtained are improved, and the MFR of the EVOH is more preferably 0.5g/10 min or more, still more preferably 1g/10 min or more, and particularly preferably 3g/10 min or more, and on the other hand, the MFR of the EVOH is more preferably 50g/10 min or less, still more preferably 30g/10 min or less, particularly preferably 15g/10 min or less, and most preferably 10g/10 min or less, and in the present invention, the melt flow rate is measured in accordance with JIS K7210.

The EVOH may comprise a mixture of 2 or more EVOH, in which case the values of the ethylene content, the saponification degree and the MFR are average values calculated from the blending mass ratio, from the viewpoint of production cost and uniformity of the obtained product, the resin composition of the present invention preferably contains 1 EVOH.

The resin composition of the present invention contains the EVOH as a main component. Here, the main component means a component having the largest content by mass. The content of the EVOH in the resin composition of the present invention is preferably 55 mass% or more. When the content is less than 55% by mass, the gas barrier property and moldability of the resin composition may become insufficient. The content is more preferably 80% by mass or more, still more preferably 90% by mass or more, particularly preferably 95% by mass or more, and most preferably 99% by mass or more.

(nonionic surfactant)

The resin composition of the present invention contains 3 ~ 400ppm of a nonionic surfactant, and the resin composition contains a specific amount of a nonionic surfactant, whereby the resin discharge amount during melt molding can be increased, and particularly, even when the resin composition contains components other than EVOH, the resin composition can increase the resin discharge amount without being affected by such components, and can secure a specific discharge amount even when the molten resin is at a low temperature.

The nonionic surfactant contained in the resin composition is not particularly limited, and is preferably at least one selected from the group consisting of ether type, amino ether type, ester type, seed type and amide type. These nonionic surfactants may be used alone, or 2 or more of them may be used in combination.

The ether-type nonionic surfactant is preferably a polyoxyalkylene alkyl ether, a polyoxyalkylene alkenyl ether or a polyoxyethylene styrenated phenyl ether.

The polyoxyalkylene alkyl ether and polyoxyalkylene alkenyl ether are preferably represented by the following formula (1).

R-O-（AO）_nH （1）

Wherein R is a linear or branched alkyl or alkenyl group having 6 ~ 22 carbon atoms, A is each independently an alkylene group having 2 ~ 4 carbon atoms, and n represents the condensation degree of a polyoxyalkylene unit and is 1 ~ 30.

In the formula (1), the number of carbon atoms of R is preferably 8 ~. a, and the number of carbon atoms of R is preferably 2 or 3. n, and is preferably 2 ~ 25, and more preferably 3 ~ 20.

Specific examples of the polyoxyalkylene alkyl ether include polyoxyethylene alkyl ethers such as polyoxyethylene hexyl ether, polyoxyethylene heptyl ether, polyoxyethylene octyl ether, polyoxyethylene-2-ethylhexyl ether, polyoxyethylene nonyl ether, polyoxyethylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene tetradecyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene eicosyl ether; polyoxypropylene alkyl ethers such as polyoxypropylene stearyl ether; polyoxyethylene polyoxypropylene alkyl ethers, and the like.

Specific examples of the polyoxyalkylene alkenyl ether include polyoxyethylene alkenyl ethers such as polyoxyethylene oleyl ether.

Specific examples of the polyoxyethylene styrenated phenyl ether include polyoxyethylene monostyrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, and polyoxyethylene tristyrenated phenyl ether, and the ethylene oxide addition number of the polyoxyethylene styrenated phenyl ether is preferably 5 ~ 30 mol.

The amino ether type nonionic surfactant is preferably a polyoxyalkylene alkylamine, a polyoxyalkylene amine or the like, the polyoxyalkylene alkylamine is preferably a cacao alkylamine-ethylene oxide adduct, a polyoxyethylene stearylamine, a polyoxyethylene laurylamine, a polyoxyethylene polyoxypropylene laurylamine, a polyoxyethylene stearylamine or the like, the polyoxyalkylene amine is preferably a polyoxyethylene oleylamine or the like, and the ethylene oxide addition number of the polyoxyalkylene alkylamine is preferably 1 ~ 40 mol.

The ester-type nonionic surfactant is preferably a polyoxyalkylene alkyl ester, polyoxyalkylene alkenyl ester, sorbitan alkyl ester, sorbitan alkenyl ester, polyoxyethylene sorbitan alkyl ester, polyoxyethylene sorbitan alkylene ester, glycerin alkyl ester, glycerin alkenyl ester, polyglycerin alkyl ester, polyglycerin alkenyl ester, or the like.

The polyoxyalkylene alkyl ester and polyoxyalkylene alkenyl ester are preferably represented by the following formula (2).

R-COO（AO）_nH （2）

Wherein R, A and n are as defined in the above formula (1) and the preferable ranges are those wherein R has 8 ~ 18 carbon atoms, A has 2 or 3 carbon atoms and n has 7 ~. n is as defined above, good discharge amount and good appearance can be achieved at the same time.

Specific examples of the polyoxyalkylene alkyl ester include polyoxyethylene monolaurate, polyoxyethylene dilaurate, polyoxyethylene monopalmitate, polyoxyethylene monostearate, and polyoxyethylene distearate.

Specific examples of the polyoxyalkylene alkenyl ester include polyoxyethylene oleate and polyethylene glycol dioleate.

As the sorbitan alkyl ester, specifically, sorbitan monohexanoate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, sorbitan tristearate, sorbitan monolaurate and the like are preferable.

The sorbitan alkenyl ester is preferably sorbitan monooleate, sorbitan trioleate, sorbitan sesquioleate, or the like.

Specific examples of the polyoxyethylene sorbitan alkyl ester include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan triisostearate, and polyoxyethylene sorbitan monolaurate.

Specific examples of polyoxyethylene sorbitan alkenyl esters include polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, and the like.

Specific examples of the glycerin alkyl ester include glycerin monostearate and glycerin monomyristate.

Specific examples of the alkenyl glycerols include glyceryl monooleate and the like.

Specific examples of the polyglycerin alkyl ester include diglycerin laurate, tetraglycerol stearate, polyglycerin laurate, and polyglycerin stearate.

Specific examples of the polyglyceryl alkenyl ester include polyglyceryl oleate.

As the above-mentioned ester/seed ether type nonionic surfactant, polyoxyethylene sorbitan alkyl ester, polyoxyethylene sorbitan alkenyl ester, and the like are preferable.

The amide-type nonionic surfactant is preferably a higher fatty acid amide, and more preferably a higher fatty acid alkanolamide.

Examples of the higher fatty acid alkanolamide include higher fatty acid mono-or dialkanolamides, specifically, caproic acid mono-or diethanolamide, caprylic acid mono-or diethanolamide, capric acid mono-or diethanolamide, lauric acid mono-or diethanolamide, palmitic acid mono-or diethanolamide, stearic acid mono-or diethanolamide, oleic acid mono-or diethanolamide, coconut fatty acid mono-or diethanolamide, and a product obtained by replacing the ethanolamide constituting these with propanolamide or butanolamide.

Examples of the higher fatty acid amide other than the higher fatty acid alkanolamide include caproic acid amide, caprylic acid amide, capric acid amide, lauric acid amide, palmitic acid amide, stearic acid amide, oleic acid amide, and the like.

The nonionic surfactant is more preferably at least one selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyethylene styrenated phenyl ethers, polyoxyalkylene alkylamines, polyoxyalkylene alkenylamines, polyoxyalkylene alkyl esters, polyoxyalkylene alkenyl esters, sorbitan alkyl esters, sorbitan alkenyl esters, polyoxyethylene sorbitan alkyl esters, polyoxyethylene sorbitan alkenyl esters, glycerin alkyl esters, glycerin alkenyl esters, polyglycerin alkyl esters, polyglycerin alkenyl esters, and higher fatty acid amides.

The nonionic surfactant is preferably an ether type or an ester type from the viewpoint of obtaining a molded body having a particularly excellent appearance, and more preferably at least one selected from the group consisting of polyoxyalkylene alkyl ethers, polyoxyalkylene alkenyl ethers, polyoxyalkylene alkyl esters, polyoxyalkylene alkenyl esters, glycerin alkyl esters, polyglycerin alkyl esters, and polyglycerin alkenyl esters from the viewpoint of coloring. These may be used alone or in combination of two or more.

The content of the nonionic surfactant in the resin composition of the present invention is 3 ~ 400ppm, and when the content is less than 3ppm, the effect of increasing the discharge amount of the resin composition and the effect of suppressing coloring are not sufficiently obtained, and the content is preferably 10ppm or more, and more preferably 50ppm or more, and when the content exceeds 400ppm, on the other hand, there is a tendency that it is economically disadvantageous, the supply of the resin to the extruder becomes insufficient due to resin slippage, the discharge amount of the resin composition is reduced, the residence time of the resin composition in the extruder becomes long, and the resin is yellowed, and the content is preferably 300ppm or less, and more preferably 150ppm or less.

(alkali metal salt)

The resin composition preferably further contains an alkali metal salt. By thus preparing the resin composition containing the alkali metal salt, the adhesiveness to other resins becomes good. In particular, interlayer adhesiveness is improved in a multilayer structure having a layer comprising the above resin composition and a layer comprising a thermoplastic resin other than the above ethylene-vinyl alcohol copolymer. Furthermore, surprisingly: by using a specific amount of the nonionic surfactant, thermal degradation of EVOH due to an alkali metal salt can be suppressed, and adhesiveness can be improved.

Examples of the alkali metal forming the alkali metal salt include lithium, sodium, potassium, and the like, and sodium and potassium are preferable. Examples of the alkali metal salt include aliphatic carboxylates such as lithium, sodium, and potassium, aromatic carboxylates, carbonates, hydrochlorides, nitrates, sulfates, phosphates, and metal complexes. Among these, sodium acetate, potassium acetate, sodium carbonate, potassium carbonate, sodium phosphate and potassium phosphate are more preferable from the viewpoint of easy availability and the like.

The resin composition of the present invention preferably contains 10 ~ 500ppm of an alkali metal salt in terms of metal element, the content of the alkali metal salt is more preferably 30ppm or more, further preferably 100ppm or more, the content is more preferably 400ppm or less, further preferably 300ppm or less, and when the content of the alkali metal salt is not less than the lower limit, the adhesion between layers can be improved when the resin composition is used as a material for forming a layer of a multilayer structure, and on the other hand, when the content of the metal salt is not more than the upper limit, the coloring of the resin composition can be suppressed.

(other Components)

The content of the other component in the resin composition is preferably 0.005 ~ 45 mass%, and the content is more preferably 20 mass% or less, further preferably 10 mass% or less, particularly preferably 5 mass% or less, and most preferably 1 mass% or less.

The resin composition preferably contains at least 1 additive selected from the group consisting of an antioxidant, an ultraviolet absorber, a plasticizer, an antistatic agent, a lubricant and a filler, and the content of the additive in the resin composition is preferably 0.005 ~ 50 mass%, and the content is more preferably 20 mass% or less, still more preferably 10 mass% or less, particularly preferably 5 mass% or less, and most preferably 1 mass% or less.

Examples of the antioxidant include N, N ' -hexane-1, 6-diylbis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide ], N ' -1, 6-hexanediylbis { N- (2,2,6, 6-tetramethyl-4-piperidyl) -formamide }, 2, 5-di-tert-butylhydroquinone, 2, 6-di-2, 2 ' -methylene-bis- (4-methyl-6-tert-butylphenol), octadecyl 3- (3 ', 5 ' -di-tert-butyl-4 ' -hydroxyphenyl) propionate, and 4,4 ' -thiobis- (6-tert-butylphenol).

Examples of the ultraviolet absorber include ethylene-2-cyano-3, 3 ' -diphenylacrylate, 2- (2 ' -hydroxy-5 ' -methylphenyl) benzotriazole, 2- (2 ' -hydroxy-3 ' -tert-butyl-5 ' -methylphenyl) -5-chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2 ' -dihydroxy-4-methoxybenzophenone, and 2-hydroxy-4-octyloxybenzophenone.

Examples of the plasticizer include dimethyl phthalate, diethyl phthalate, dioctyl phthalate, wax, liquid paraffin, and phosphate ester.

Examples of the antistatic agent include pentaerythritol monostearate, sorbitan monopalmitate, sulfated polyolefins, polyethylene oxide, and polyethylene glycol (trade name: CARBOWAX).

Examples of the lubricant include ethylene bis stearamide and butyl stearate.

Examples of the filler include glass fiber, wollastonite, calcium silicate, talc, and montmorillonite.

The resin composition may contain a thermoplastic resin other than EVOH as another component. Examples of the thermoplastic resin include polyolefins [ e.g., polyethylene, polypropylene, poly (1-butene), poly (4-methyl-1-pentene), ethylene-propylene copolymers, copolymers of ethylene and an α -olefin having 4 or more carbon atoms, copolymers of an olefin and maleic anhydride, ethylene-vinyl ester copolymers, ethylene-acrylic ester copolymers, and modified polyolefins obtained by graft-modifying these with an unsaturated carboxylic acid or a derivative thereof ]; nylon (nylon 6, nylon 66, nylon 6/66 copolymer, etc.); polyvinyl chloride; polyvinylidene chloride; a polyester; polystyrene; polyacrylonitrile; a polyurethane; a polyacetal; modified polyvinyl alcohol, and the like. The content of the thermoplastic resin other than EVOH in the resin composition is preferably 45 mass% or less, more preferably 20 mass% or less, further preferably 10 mass% or less, particularly preferably 5 mass% or less, and most preferably 1 mass% or less.

The resin composition may contain various compounds such as acids as other components in view of adjusting thermal stability and viscosity. Examples of the compound include carboxylic acids, phosphoric acid compounds, and boron compounds, and specifically, the following compounds are mentioned. These compounds may be contained in EVOH in advance.

Carboxylic acid: oxalic acid, succinic acid, benzoic acid, citric acid, acetic acid, lactic acid, etc

Phosphoric acid compound: various acids such as phosphoric acid and phosphorous acid, and salts thereof

Boron compound: boric acid, boric acid ester, boric acid salt, boron hydride, etc

The MFR of the resin composition is preferably in the same range as that of the EVOH. The effect obtained by setting the MFR of the resin composition to such a range is also the same as that of EVOH.

(method for producing resin composition)

The method for producing the resin composition of the present invention is not particularly limited, and a method of melt-kneading a mixture containing the EVOH, the nonionic surfactant, and other components as necessary may be mentioned.

The melt-kneading of the EVOH, the nonionic surfactant and the like can be carried out by using a known mixing apparatus or kneading apparatus such as a Kneader-Kneader, an extruder, a kneading roll, a Banbury mixer and the like, examples of the form of the nonionic surfactant include a solid such as a powder, a melt, a solution such as an aqueous solution and a dispersion such as an aqueous dispersion, and the nonionic surfactant of this form can be mixed with the EVOH and other components, and the form of the nonionic surfactant is preferably a solution and a dispersion, and the temperature at the time of melt-kneading the mixture containing the EVOH and the nonionic surfactant and the like may be appropriately adjusted depending on the melting point of the EVOH to be used and is usually 120 ℃ ~ 300 ℃.

The content of water in the mixture is preferably 0.1 ~ 50 parts by mass, more preferably 0.5 ~ 50 parts by mass, per 100 parts by mass of the EVOH, and when the content is less than 0.1 parts by mass, the resulting resin composition may be easily colored, while when the content exceeds 50 parts by mass, the EVOH may be separated from water and the resin composition discharged from the extruder may be easily foamed, and the water content in the mixture is the total amount of water added separately and water added together with other components, and further includes the nonionic surfactant and water contained in the EVOH due to moisture absorption and the like.

In the above production method, it is preferable that the mixture is obtained by adding an aqueous solution or an aqueous dispersion containing the nonionic surfactant to the EVOH. By adding the nonionic surfactant in the form of an aqueous solution or an aqueous dispersion, the nonionic surfactant can be easily dispersed in the EVOH.

In the above production method, the nonionic surfactant may be added to the EVOH before melting, or may be added to the EVOH after melting. The latter is preferable from the viewpoint of productivity.

As a method for melt-kneading a mixture containing the nonionic surfactant, water and the EVOH, for example, there can be mentioned a method in which the EVOH is introduced into an extruder, then the molten EVOH is kneaded with the nonionic surfactant and other components as needed and then discharged, and in this case, the EVOH having a water content of 5 ~ mass% may be introduced into an extruder.

[ formed article ]

The molded article containing the resin composition thus obtained is a preferred embodiment of the present invention. The molded article may be composed only of the resin composition, or may have a portion containing the resin composition and a portion containing a composition other than the resin composition.

Examples of the molded article containing the resin composition include pellets, films, sheets, containers (bags, cups, tubes, trays, bottles, etc.), fuel containers, tubes, fibers, packaging materials for beverages and foods, filling materials for containers, packaging materials for medical infusions, tubes for tires, cushioning materials for shoes, inner bag materials for bags for box liners, tanks for storing organic liquids, tubes for transporting organic liquids, warm water tubes for heating (warm water tubes for floor heating, etc.), packaging materials for cosmetics, packaging materials for dental care, packaging materials for pharmaceuticals, small parts for bags (caps, valve parts for bags for box liners, etc.), agricultural bottles, agricultural films (greenhouse films, films for soil fumigation), bags for grain protection, geomembranes, wallpaper or cosmetic boards, and gas tanks for hydrogen gas, oxygen gas, etc. Examples of the fuel container include fuel containers mounted on automobiles, motorcycles, ships, airplanes, generators, industrial machines, agricultural machines, and the like, portable containers for replenishing fuel to these fuel containers, containers for storing fuel, and the like. The fuel is gasoline, and a typical example of the fuel is oxygen-containing gasoline blended with methanol, ethanol, MTBE, or the like. Further, other heavy oil, light oil, kerosene, and the like can be cited.

The molded article can be produced by melt-molding the resin composition, and can be molded again after being pulverized for reuse, or a film, a sheet, a fiber, or the like can be uniaxially or biaxially stretched, and any known molding method such as extrusion molding, inflation extrusion, blow molding, melt spinning, injection molding can be applied as the melt-molding method, and the melt temperature in melt-molding is preferably 150 ~ 300 ℃, and more preferably 200 ~ 250 ℃.

The molded article is preferably a multilayer structure having a layer containing the resin composition and a layer containing a thermoplastic resin other than EVOH. The resin composition is excellent in long-term run stability, and is suppressed in the occurrence of coloring such as yellowing, gels, lumps, fish eyes, streaks, and the like after melt molding. Therefore, by melt molding using the above resin composition and other thermoplastic resins, a multilayer structure having an excellent appearance can be produced with good productivity.

The thickness structure of the multilayer structure is not particularly limited, and the thickness ratio of the resin composition layer to all the layer thicknesses is preferably 2 ~ 20% from the viewpoint of moldability, cost, and the like, and the layer structure of the multilayer structure is not particularly limited, and when the other thermoplastic resin layer is denoted by a, the resin composition layer is denoted by B, and the adhesive resin layer is denoted by C, the layer structure may be constituted by, for example, a/B, A/B/A, A/C/B, A/C/B/C/A, A/B/a/B/A, A/C/B/C/a, or the like.

The adhesive resin is preferably a carboxylic acid-modified polyolefin. As the carboxylic acid-modified polyolefin, a carboxyl group-containing modified olefin polymer obtained by chemically (for example, addition reaction, graft reaction, or the like) bonding an ethylenically unsaturated carboxylic acid, an ester thereof, or an anhydride thereof to an olefin polymer can be suitably used. Examples of the ethylenically unsaturated carboxylic acid, ester thereof, or anhydride thereof include maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride, monomethyl maleate, monoethyl maleate, diethyl maleate, monomethyl fumarate, etc., and maleic anhydride is more preferred. These adhesive resins may be used alone, or two or more of them may be used in combination.

Examples of the other thermoplastic resins include polyolefins such as linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polypropylene, propylene- α -olefin copolymer, polybutene, and polypentene; polyesters such as polyethylene terephthalate; a polyester elastomer; polyamides such as nylon 6 and nylon 66; polystyrene; polyvinyl chloride; polyvinylidene chloride; an acrylic resin; a vinyl ester resin; a polyurethane elastomer; a polycarbonate; chlorinated polyethylene; chlorinated polypropylene. Among these, polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyamide, polystyrene, and polyester are preferably used.

Among these, it is preferable to use a polyolefin layer as the other thermoplastic resin layer and a carboxylic acid-modified polyolefin layer as the adhesive resin layer. This is because: by providing the polyolefin layer, the mechanical properties of the multilayer structure are improved and the moisture resistance is also improved. In particular, it is preferable to provide polyolefin layers on both outer layers of the above multilayer structure for effectively preventing moisture absorption of the resin composition layer. In this case, the recycled resin may be added to the polyolefin within a range not to impair the effect.

Examples of the method for producing the multilayer structure include the following methods.

(1) A method of coextruding the above resin composition with other thermoplastic resin

(2) Method for melt-extruding other thermoplastic resin on formed body containing the resin composition

(3) A method of co-injecting the above resin composition with other thermoplastic resin

(4) A method of laminating a molded article comprising the resin composition and a molded article comprising another thermoplastic resin with an adhesive.

Among these methods, (1) is preferable. The resin composition of the present invention is excellent in long-term run stability even when melt-molded under high temperature conditions, and is suppressed in coloration after melt-molding. Therefore, even when the resin composition is coextruded with another thermoplastic resin having a high melting point, coloring is suppressed, and a multilayer structure having excellent appearance can be obtained. Examples of the coextrusion method include a multi-manifold confluence type T-die method, a feeding block confluence type T-die method, and an inflation method.

The multilayer structure obtained by the above coextrusion is subjected to secondary processing to obtain, for example, the following molded article.

(1) A multilayer stretched sheet or multilayer stretched film obtained by stretching a multilayer structure (sheet, film, etc.) in a uniaxial direction or a biaxial direction and heat-treating

(2) Multilayer rolled sheet or multilayer rolled film obtained by rolling multilayer structure (sheet, film, etc.)

(3) Multilayer tray or multilayer cup-shaped container obtained by thermoforming (vacuum forming, pressure-air forming, vacuum pressure-air forming, or the like) a multilayer structure (sheet, film, or the like)

(4) Multilayer bottles, multilayer cup-shaped containers, and the like obtained by stretch blow molding a multilayer structure (such as a tube).

The molded article obtained by performing these secondary processes can be preferably used as a food container such as a deep-drawing container, a cup-like container, and a bottle.