Resin composition, resin composition for recovery aid, use in recovery aid, regrind layer, multilayer structure, package, food package, recovery aid, and method for producing regrind layer

Abstract

The invention described below is provided as a resin composition having exceptional thermal stability and coloring suppression properties. A resin composition (X) containing an ethylene-vinyl acetate copolymer (A), wherein the ethylene-vinyl acetate copolymer (A) contains carbon 14.

Description

Resin composition, resin composition for recovery aid, use in recovery aid, regrind layer, multilayer structure, packaging, food packaging, recovery aid and method for producing regrind layer

[0001] The present invention relates to a resin composition, a resin composition for a recovery aid, use in a recovery aid, a regrind layer, a multilayer structure, a package, a food package, a recovery aid, and a method for producing a regrind layer.

[0002] Conventionally, ethylene-vinyl alcohol copolymers (hereinafter referred to as "EVOH") having an ethylene content of 60 mol% or less have been mainly used as food packaging materials due to their excellent gas barrier properties and transparency. Sheets, films, etc. used as the food packaging materials can be produced using the above-mentioned EVOH alone, but they are often blended with other thermoplastic resins to improve physical properties, or multilayer structures in which layers made of polyolefin resins or the like are laminated to impart other functions.

[0003] Recently, in order to reduce the environmental load, used resin products, resin scraps and end parts generated in the manufacturing process of resin products, or defective products have been collected, and the collected products have been recycled again as resin compositions containing EVOH and polyolefin.

[0004] However, when a resin composition containing EVOH or a polyolefin is repeatedly melt-molded, the quality of the resin composition deteriorates due to the influence of thermal history, which has become a problem. As a resin composition that is less susceptible to the influence of repeated thermal history, for example, a resin composition containing an ethylene-vinyl acetate copolymer (hereinafter referred to as "EVA") and a saponified EVA having an ethylene content of more than 60 mol% has been proposed (see Patent Document 1 listed below).

[0005] Meanwhile, a resin composition containing EVA derived from biomass resources has been proposed as a resin composition that has reduced carbon emissions compared to materials produced using only fossil fuel sources (see Patent Document 2 below).

[0006] International Publication No. 2009 / 041440 Special Publication No. 2021-536526

[0007] The present invention provides a resin composition that has excellent thermal stability and is inhibited from discoloring.

[0008] However, as a result of intensive research conducted by the present inventors to solve the above-mentioned problems, it has been found that in a resin composition containing EVA and a saponified EVA, the EVA and / or the saponified EVA has a carbon-14 ( 14 It has been found that the above problem can be solved by using a material containing C (radioactive carbon 14, half-life 5730 years).

[0009] That is, the present invention has the following aspects. [1] Resin composition (X) containing EVA (A), wherein the EVA (A) contains 14 carbon atoms. [2] Resin composition (X) containing EVA (A) and a saponified EVA (B) having an ethylene content of more than 60 mol%, wherein the EVA (A) and / or the saponified EVA (B) contain 14 carbon atoms. [3] Resin composition (X) according to [2], wherein the EVA (A) contains 14 carbon atoms. [4] Resin composition (X) according to [2], wherein the biobased content of the EVA (A) and / or the saponified EVA (B) having an ethylene content of more than 60 mol% is 1 to 100%. [5] Resin composition (X) according to any of [1] to [4], wherein the biobased content of the EVA (A) is 1 to 100%. [6] Resin composition (X) according to any one of [1] to [4], wherein the EVA (A) has a biobased content of 40 to 100%. [7] Resin composition (X) according to any one of [1] to [6], wherein the EVA (A) has an ethylene content of 60 to 98 mol%. [8] A resin composition for use as a recovery aid, comprising the resin composition (X) according to any one of [1] to [7]. [9] Use of the resin composition (X) according to any one of [1] to [7] as a recovery aid.

[10] A recovery aid, comprising the resin composition (X) according to any one of [1] to [7].

[11] Resin composition (X) according to any one of [1] to [7], further comprising a polyolefin resin (C).

[12] Resin composition (X) according to any one of [1] to [7], further comprising an EVOH (D) having an ethylene content of 60 mol% or less.

[13] Resin composition (Y) containing EVA (A), polyolefin resin (C), and EVOH (D), wherein the EVA (A) contains 14 carbon atoms.

[14] Resin composition (Y) containing EVA (A), a saponified EVA (B) having an ethylene content of more than 60 mol%, polyolefin resin (C), and EVOH (D), wherein the EVA (A) and / or the saponified EVA (B) contains 14 carbon atoms.

[15] Resin composition (Y) according to

[13] or

[14] , further containing hydrotalcites (E).

[16] Resin composition (Y) according to any one of

[13] to

[15] , further containing a higher fatty acid metal salt (F).

[17] Resin composition (Y) according to

[16] , wherein the higher fatty acid metal salt (F) is at least one selected from the group consisting of higher fatty acid calcium salt, higher fatty acid magnesium salt, and higher fatty acid zinc salt.

[18] Resin composition (Y) according to any one of

[13] to

[17] , further comprising a titanium compound (G).

[19] Resin composition (Y) according to

[18] , wherein the titanium compound (G) is titanium oxide.

[20] A regrind layer comprising the recovery aid according to

[10] .

[21] A multilayer structure comprising the regrind layer according to

[20] .

[22] The multilayer structure according to

[21] , further comprising a layer comprising a polyolefin resin (but excluding EVA (A)).

[23] The multilayer structure according to

[21] or

[22] , further comprising an adhesive resin layer different from the regrind layer (but excluding EVA (A)).

[24] A package comprising the multilayer structure according to any one of

[21] to

[23] .

[25] A food package comprising the multilayer structure according to any one of

[21] to

[23] .

[26] A method for producing a recovery aid, comprising the step of mixing EVA (A) and a saponified EVA (B) having an ethylene content of more than 60 mol%, wherein the EVA (A) and / or the saponified EVA (B) contain carbon-14.

[27] A method for producing a regrind layer by molding a resin composition, comprising the step of mixing a polyolefin resin (C), EVOH (D), EVA (A), and a saponified EVA (B) having an ethylene content of more than 60 mol%, wherein the EVA (A) and / or the saponified EVA (B) contain carbon-14.

[0010] The resin composition (X) according to one embodiment of the present invention is a resin composition containing EVA or a resin composition containing EVA and a saponified EVA, and is excellent in thermal stability and coloration suppression. Therefore, the resin composition (X) of the present invention can be suitably used as a raw material for molded articles and multilayer structures that are excellent in thermal stability and coloration suppression.

[0011] Furthermore, the resin composition (X) can be suitably used as a recovery aid for increasing the thermal stability of recycled resin compositions and maintaining a certain level of quality when used resin products containing polyolefin resins and EVOH, or resin scraps discarded during the production process, are recovered and recycled.

[0012] Furthermore, resin composition (Y), which is another embodiment of the present invention, is a resin composition containing a polyolefin resin and EVOH, and yet has excellent thermal stability and coloration suppression properties. Therefore, resin composition (Y) of the present invention can be suitably used as a raw material for molded articles and multilayer structures that are excellent in thermal stability and coloration suppression properties.

[0013] Furthermore, the resin composition (Y) is particularly suitable when it is a recycled resin composition in which the polyolefin resin and EVOH are recovered from used resin products or resin scraps discarded during the production process, because the resin composition (Y) is not subject to thermal degradation and maintains a certain level of quality.

[0014] The present invention will be described in more detail below based on examples of the present invention, but the present invention is not limited to the following embodiments.

[0015] In this specification, when the expression "x to y" (x and y are arbitrary numbers) is used, unless otherwise specified, it means "x or more and y or less," as well as "preferably greater than x" or "preferably less than y." Furthermore, when the expression "X or more" (X is an arbitrary number) or "Y or less" (Y is an arbitrary number) is used, it also means "preferably greater than X" or "preferably less than Y." Furthermore, "X and / or Y (X and Y are arbitrary configurations)" means at least one of X and Y, and can mean three possibilities: X only, Y only, or X and Y. Furthermore, in this specification, "film" also means "tape" and "sheet." Regarding the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical range can also be replaced with the values ​​shown in the examples.

[0016] First, resin composition (X) (hereinafter referred to as "the present resin composition (X)"), which is a first aspect of the present invention, is a resin composition (X) containing EVA (A), wherein the EVA (A) contains 14 carbon atoms, and resin composition (X) is a resin composition (X) containing EVA (A) and a saponified EVA (B) having an ethylene content of more than 60 mol%, wherein the EVA (A) and / or the saponified EVA (B) contains 14 carbon atoms.

[0017] Next, resin composition (Y) (hereinafter referred to as "the present resin composition (Y)"), which is a second aspect of the present invention, is a resin composition (Y) containing EVA (A), a polyolefin resin (C), and an EVOH (D), wherein the EVA (A) contains 14 carbon atoms. Also, resin composition (Y) is a resin composition (Y) containing EVA (A), a saponified EVA (B), a polyolefin resin (C), and EVOH (D), wherein the EVA (A) and / or the saponified EVA (B) contains 14 carbon atoms. The first and second aspects will be described below in order.

[0018] <<First Aspect>> The present resin composition (X) is either a resin composition (X) containing EVA (A), wherein the EVA (A) contains 14 carbon atoms, or a resin composition (X) containing EVA (A) and a saponified EVA (B) having an ethylene content of more than 60 mol%, wherein the EVA (A) and / or the saponified EVA (B) contains 14 carbon atoms. The present resin composition (X) is suitable for use as a recovery aid, and can therefore be used as a resin composition for a recovery aid (hereinafter referred to as the "present resin composition for a recovery aid"). Each component will be described below.

[0019] <EVA (A)> The term "EVA" in the EVA (A) used in the present resin composition (X) refers to a polymer obtained by copolymerizing ethylene and vinyl acetate. In the present resin composition (X), the EVA (A) and / or the saponified EVA (B) having an ethylene content of more than 60 mol% contains 14 carbon atoms, and it is particularly preferred that the EVA (A) contains 14 carbon atoms.

[0020] Carbon-14 EVA refers to EVA obtained by chemical or biological synthesis using renewable biomass resources (hereinafter referred to as "bioEVA"). BioEVA has the advantage that even if it is incinerated, it does not increase the concentration of carbon dioxide in the atmosphere due to the carbon-neutral nature of biomass.

[0021] The carbon in petroleum-derived EVA does not contain carbon-14, but bio-EVA does. 14 The concentration of C can be measured by accelerator mass spectrometry and used as an indicator of the presence or absence of bio-EVA or the content ratio (bio-based degree).

[0022] Among the biomass resources, plant materials are preferred, and for example, plant-derived ethylene derived from bioalcohol or vinyl acetate derived from biomass resources is preferred. That is, the carbon-14-containing EVA (A) is preferably EVA derived from plant materials.

[0023] The biobased content can be measured, for example, by the following method: A sample to be measured is burned to generate carbon dioxide, which is then purified in a vacuum line and reduced with hydrogen using iron as a catalyst to generate graphite. This graphite is then subjected to a tandem accelerator-based 14 Attach it to a C-AMS dedicated device (NEC) 14 Counting C, 13 The concentration of C ( 13 C / 12 C), 14 The concentration of C ( 14 C / 12 C) is measured, and the carbon content of the sample is compared to that of the standard modern carbon. 14 The C concentration ratio is calculated.

[0024] The biobased content of the EVA (A) used in the resin composition (X) is usually 1 to 100%, preferably 5 to 100%, more preferably 10 to 100%, even more preferably 40 to 100%, and particularly preferably 60 to 90%. By setting the biobased content of the EVA (A) within this range, a resin composition (X) with even better thermal stability can be obtained.

[0025] The reason why the resin composition (X) has excellent thermal stability and coloration suppression is that it contains 14 carbon atoms ( 14 This is thought to be because bio-EVA containing carbon-14 has stronger binding energy due to the primary isotope effect than petroleum-derived EVA that does not contain carbon-14, resulting in slower decomposition and improved thermal stability and color inhibition.

[0026] The ethylene content in the EVA (A) is usually 1 to 99 mol%, preferably 60 to 98 mol%, and more preferably 70 to 95 mol%. That is, when the ethylene content is equal to or greater than the lower limit, the resin composition (X) tends to have excellent thermal stability and extrusion moldability, while when the ethylene content is equal to or less than the upper limit, the resin composition (X) tends to have excellent discoloration suppression properties.

[0027] The vinyl acetate content in the EVA (A) is usually 1 to 60 mol %, preferably 2 to 40 mol %, and more preferably 3 to 30 mol %. That is, when the vinyl acetate content is equal to or greater than the lower limit, the resin composition (X) tends to have excellent coloration suppression properties, and when the vinyl acetate content is equal to or less than the upper limit, the resin composition (X) tends to have excellent thermal stability and extrusion moldability.

[0028] The melt flow rate (MFR) (190°C, 2160 g load) of the EVA (A) is usually 0.1 to 100 g / 10 min, more preferably 0.5 to 50 g / 10 min, and particularly preferably 1 to 30 g / 10 min. Having an MFR within the above range improves dispersibility in other resins when mixed with them, and tends to facilitate the development of the effects of the present invention. The MFR can be measured in accordance with JIS K7120.

[0029] The EVA (A) may be a modified product containing a carboxy group obtained by chemically bonding an unsaturated carboxylic acid or an anhydride thereof by addition reaction, graft reaction, or the like, as long as the purpose of the present invention is not impaired. The amount of such modification is preferably 10 mol% or less. Examples of the unsaturated carboxylic acid or anhydride thereof include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, and crotonic acid, and ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, as well as their anhydrides and half esters. Among these, maleic anhydride is preferably used.

[0030] The EVA (A) may be used alone or in combination of two or more bio-EVAs differing in ethylene content, molecular weight, MFR, density, modifying group, and modification level. The EVA (A) may be a petroleum-derived petroleum EVA. Furthermore, the EVA (A) may be a petroleum-derived petroleum EVA in which some of the carbon atoms have been replaced with carbon-14.

[0031] The content of the EVA (A) in the resin composition (X) is usually 1 to 99% by mass, preferably 10 to 98% by mass, more preferably 30 to 97% by mass, even more preferably 50 to 96% by mass, and particularly preferably 70 to 95% by mass. By setting the content of EVA (A) within the above range, the resin composition (X) can be made to have particularly excellent thermal stability.

[0032] <Saponified EVA (B) having an ethylene content of more than 60 mol%> The saponified EVA (B) having an ethylene content of more than 60 mol% used in the present resin composition (X) is a saponified EVA, and is obtained by saponifying the vinyl acetate component of EVA having an ethylene content of more than 60 mol%.

[0033] The saponified EVA (B) having an ethylene content of more than 60 mol% (hereinafter referred to as "high-ethylene saponified EVA (B)") can be polymerized by any known polymerization method, such as solution polymerization, suspension polymerization, emulsion polymerization, etc., and the resulting copolymer can also be saponified by a known method. The high-ethylene saponified EVA (B) may be modified as necessary.

[0034] The ethylene content of the high-ethylene EVA saponification product (B) may be more than 60 mol%, and is usually 98 mol% or less, more preferably 70 to 97 mol%, further preferably 75 to 95 mol%, and particularly preferably 80 to 95 mol%. When the ethylene content is within the above range, the effects of the present invention (thermal stability and coloration suppression) tend to be more effectively obtained.

[0035] The saponification degree of the high-ethylene EVA saponified product (B) is usually 20 mol % or more, preferably 40 to 99.5 mol %, and particularly preferably 80 to 99 mol %. That is, when the saponification degree is within the above range, the effects of the present invention (thermal stability, etc.) tend to be more effectively obtained.

[0036] The melt flow rate (MFR) (190°C, 2160 g load) of the high-ethylene EVA saponification product (B) is usually 0.5 to 100 g / 10 min, more preferably 1 to 50 g / 10 min, and particularly preferably 2 to 30 g / 10 min, from the viewpoint of excellent dispersibility and the effects of the present invention. Such MFR can be measured in accordance with JIS K7120.

[0037] The saponified high-ethylene EVA (B) may be a modified product containing a carboxy group obtained by chemically bonding an unsaturated carboxylic acid or an anhydride thereof by addition reaction, graft reaction, or the like, as long as the purpose of the present invention is not impaired. The amount of such modification is preferably 10 mol% or less. Examples of the unsaturated carboxylic acid or anhydride thereof include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, and crotonic acid, and ethylenically unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, as well as their anhydrides and half esters. Among these, maleic anhydride is preferably used.

[0038] The high ethylene saponified EVA (B) may be used alone, or two or more high ethylene content saponified EVAs differing in ethylene content, saponification degree, molecular weight, MFR, density, modifying group, modification amount, etc. may be used in combination.

[0039] The high ethylene EVA saponification product (B) used in the present resin composition (X) preferably contains 14 carbon atoms.

[0040] The biobased content of the high ethylene EVA saponified product (B) used in the present resin composition (X) is usually 1 to 100%, preferably 5 to 100%, more preferably 10 to 100%, even more preferably 40 to 100%, and particularly preferably 60 to 90%. By setting the biobased content of the high ethylene EVA saponified product (B) within the above range, a resin composition (X) having even better thermal stability can be obtained.

[0041] The content of the high-ethylene EVA saponification product (B) is usually 0.001 to 30% by mass, preferably 0.005 to 25% by mass, more preferably 0.05 to 10% by mass, and even more preferably 1.0 to 5% by mass. That is, when the ethylene content is equal to or less than the upper limit, the resin composition (X) tends to have excellent coloration suppression properties, and when the ethylene content is equal to or greater than the lower limit, the appearance of a molded article obtained from the resin composition (X) tends to be good.

[0042] The total amount [(A) + (B)] of the EVA (A) and the high-ethylene saponified EVA (B) in the entire resin composition (X) is usually 70 to 100 mass% based on the entire resin composition (X).

[0043] The resin composition (X) may contain other thermoplastic resins other than the components (A) and (B), such as polyamide resins, polyester resins, and polyolefin resins, within the range that does not impair the effects of the present invention (for example, less than 30% by mass based on the total amount of the resin composition (X)).

[0044] In addition, it is preferable to use, in the present resin composition (X), for example, hydrotalcites (E) and / or a metal salt of a higher fatty acid (F) in combination with the above-mentioned EVA (A) and high-ethylene EVA saponification product (B), because this improves the effect of suppressing the generation of foreign matter (dye deposits) due to phase separation when a molded article is obtained using the present resin composition (X). Among these, hydrotalcites (E) are preferably used because they are particularly effective in suppressing discoloration when a regrind layer is obtained using recycled resin.

[0045] <Hydrotalcites (E)> Examples of the hydrotalcites (E) include hydrotalcite solid solutions represented by the following general formula (1).

[0046] [Chemical formula 1] [(M1 2+ ) y1 (M2 2+ ) y2 〕 1-x M x 3+ (OH)2A n- x / n ・mH2O...(1) [In the formula, M1 2+is at least one metal selected from Mg, Ca, Sr, and Ba, M2 2+ is at least one metal selected from Zn, Cd, Pb, and Sn; M x 3+ is a trivalent metal, A n- is an n-valent anion, and x, y1, y2, and m are positive numbers satisfying the conditions 0<x≦0.5, 0.5<y1<1, y1+y2=1, and 0≦m<2.

[0047] In the above general formula (1), M 2+ As the element, Mg and Ca are preferable, and M2 2+ As the element, Zn and Cd are preferable. x 3+ Examples of the elements include Al, Bi, In, Sb, B, Ga, and Ti, which may be used alone or in combination of two or more, but Al is particularly suitable for practical use. n- For example, CO3 2- , OH - , HCO3 - , salicylate ion, citrate ion, tartrate ion, NO3 - , I - , (OOC-COO) 2- , ClO 4- , CH3COO - , CO3 2- , (OOCHC=CHCOO) 2- , [Fe(CN)6] 4- These may be used alone or in combination of two or more kinds, among which CO3 2- YaOH - is particularly useful.

[0048] Specific examples of the hydrotalcite solid solution include [Mg 0.75 Zn 0.25 ] 0.67 Al 0.33 (OH)2(CO3) 0.165 ・0.45H2O, [Mg 0.79 Zn 0.21 ] 0.7 Al 0.3 (OH)2(CO3) 0.15 , [Mg 1 / 7 Ca 3 / 7 Zn3 / 7 ] 0.7 Al 0.3 (OH)2(OOCHC=CHCOO) 0.15 ・0.41H2O[Mg 6 / 7 Cd 1 / 7 ] 0.7 Al 0.3 (OH)2(CH3COO) 0.3 ・0.34H2O[Mg 5 / 7 Pd 2 / 7 ] 0.7 Al 0.30 (O2) (CO3) 0.15 ・0.52H2O[M2 0.74 Zn 0.26 ] 0.68 Al 0.32 (O2) (CO3) 0.16 [M' 0.56 Zn 0.44 ] 0.68 Al 0.32 (O2) (CO3) 0.16 ・0.2H2O[Mg 0.81 Zn 0.19 ] 0.74 Al 0.26 (O2) (CO3) 0.13 [M' 0.75 Zn 0.25 ] 0.8 Al 0.20 (O2) (CO3) 0.10 ・0.16H2O[Mg 0.71 Zn 0.29 ] 0.7 Al 0.30 (OH)2 (NO3) 0.30 [M' 0.71 Zn 0.29 ] 0.7 Al 0.30 (OH)2(OOCHC=CHCOO) 0.15 [M' 0.14 Ca 0.57 Zn 0.28 ] 0.7 Al 0.30 (OH) 2.3 ・0 0.75 Zn 0.25 ] 0.67 Al 0.33 (O2) (CO3) 0.165 ・0.45H2O[Mg0.79 Zn 0.21 ] 0.7 Al 0.3 (OH)2(CO3) 0.15 , [Mg 6 / 7 Cd 1 / 7 ] 0.7 Al 0.3 (OH)2(CH3COO) 0.3 ・0.34H2O, [Mg 5 / 7 Pd 2 / 7 ] 0.7 Al 0.30 (OH)2(CO3) 0.15 ・0.52H2O, etc.

[0049] Further, examples of the hydrotalcites (E) include compounds represented by the following general formula (2).

[0050] [Chemical formula 2] M i Al j (OH) 2i+3j-2z (E) z aH2O (2) [wherein M is Mg, Ca, or Zn, E is CO3 or HPO4, i, j, and z are positive numbers, and a is 0 or a positive number.]

[0051] Specific examples of the compound represented by the general formula (2) include Mg 4.5 Al(OH) 13 CO3・3.5H2O, Mg5Al2(OH) 14 CO3・4H2O, Mg6Al2(OH) 16 CO3・4H2O, Mg8Al2(OH) 20 CO3.5H2O, Mg 10 Al(OH) 22 (CO3)2・4H2O, Mg6Al2(OH) 16 HPO4・4H2O, Ca6Al2(OH) 16 CO3・4H2O, Zn6Al6(OH) 16Examples of suitable compounds include CO3·4H2O. Furthermore, without being limited to the above, compounds with an unclear chemical formula, such as Mg2Al(OH)9·3H2O in which some of the OH groups have been replaced with CO3 or HPO4, and compounds with no crystal water (a = 0) can also be expected to produce similar effects. Of these, compounds in which M is Mg and E is CO3 are particularly suitable, as they effectively suppress molding stability and the deterioration of appearance due to coloration caused by phase separation and the formation of foreign matter (so-called "seam deposits").

[0052] The particle size of the hydrotalcites (E) is, for example, usually 10 μm or less, more preferably 5 μm or less, and particularly preferably 1 μm or less. That is, when the average particle size is equal to or less than the upper limit, the effects of the present invention tend to be more effectively obtained. The average particle size here is a value measured by the LUZEX method.

[0053] Among the above hydrotalcites (E), it is particularly preferable to use the hydrotalcite solid solution represented by the general formula (1) above, because it has high molding stability, a high effect of suppressing the formation of phase-separated foreign matter (dye deposits), and a high effect of suppressing coloration.

[0054] When the hydrotalcites (E) are used, their content is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass, relative to 100% by mass of the EVA (A). When the content is equal to or greater than the lower limit, molding stability and the effect of suppressing foreign matter and discoloration tend to be good, while when the content is equal to or less than the upper limit, the appearance of the molded product tends to be good, and the effect of suppressing discoloration and mechanical properties tend to be excellent.

[0055] <Higher Fatty Acid Metal Salt (F)> Examples of the higher fatty acid metal salt (F) include metal salts of organic acids having 8 or more carbon atoms (more preferably 12 to 30 carbon atoms, particularly preferably 14 to 22 carbon atoms), such as alkali metal salts of lithium, sodium, potassium, etc.; alkaline earth metal salts of magnesium, calcium, barium, etc.; and transition metal salts of zinc, copper, cobalt, iron, manganese, etc. Among these, from the viewpoints of molding stability and the effect of suppressing phase-separated foreign matter (dye deposits) and coloration, alkaline earth metal salts and transition metal salts of higher fatty acids having 14 to 22 carbon atoms are preferred, and magnesium salts, calcium salts, and zinc salts of stearic acid, hydroxystearic acid, oleic acid, and lauric acid are particularly preferred.

[0056] When the higher fatty acid metal salt (F) is used, its content is not particularly limited, but is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass, relative to 100% by mass of the EVA (A). When the content is equal to or greater than the lower limit, molding stability and the effect of suppressing foreign matter and discoloration tend to be easily obtained, while when the content is equal to or less than the upper limit, the appearance of the obtained molded article tends to be good, and the effect of suppressing discoloration and mechanical properties tend to be excellent.

[0057] When the hydrotalcites (E) and the higher fatty acid metal salt (F) are used in combination, the content of each of them is preferably within the above range.

[0058] Furthermore, in the resin composition (X), a titanium compound (G) can be used together with the EVA (A) and the high-ethylene saponified EVA (B). The titanium compound (G) is used as a pigment or is contained in the recovered pulverized material, but the incorporation of such a titanium compound (G) tends to reduce the thermal stability of the resin composition (X). Even when the resin composition (X) contains the titanium compound (G), the effect of improving the thermal stability can be obtained, and at the same time, the resin composition (X) exhibits even better coloration suppression.

[0059] <Titanium Compound (G)> Examples of the titanium compound (G) include inorganic titanium compounds and organic titanium compounds. The titanium compounds may be used alone or in combination of two or more. Among these, inorganic titanium compounds are preferred.

[0060] Examples of the inorganic titanium compounds include titanium oxide, titanium hydroxide, titanium chloride, and inorganic salts of titanium. Examples of the titanium oxides include titanium(II) oxide, titanium(III) oxide, titanium(IV) oxide, and titanium suboxide. Examples of the titanium hydroxides include titanium(I) hydroxide and titanium(II) hydroxide. Examples of the titanium chlorides include titanium(I) chloride and titanium(II) chloride. Examples of the inorganic salts of titanium include titanium phosphate and titanium sulfate. Among these, titanium oxide is preferred, titanium(IV) oxide is more preferred, and rutile-type titanium(IV) oxide is particularly preferred.

[0061] Examples of the organic titanium compounds include titanium carboxylates such as titanium acetate, titanium butyrate, and titanium stearate.

[0062] The titanium compound (G) may exist in the resin composition (X) as a titanium compound, or may exist in an ionized state or in the form of a complex interacting with a resin component or other ligands.

[0063] When the titanium compound (G) is used, its average particle size is usually 0.001 to 100 μm, preferably 0.01 to 50 μm, and more preferably 0.015 to 20 μm.

[0064] When the titanium compound (G) is used, the content thereof in terms of metal is preferably 1 to 20 mass %, more preferably 1 to 15 mass %, even more preferably 1 to 10 mass %, and particularly preferably 1 to 8 mass %, based on the total mass of the present resin composition (X).

[0065] The content of the titanium compound (G) in terms of metal can be determined by weighing out the resin composition (X) into a platinum crucible, ashing it with a burner and then an electric furnace, thermally decomposing the ashed material with nitric acid and hydrofluoric acid, treating it with a mixed acid of dilute nitric acid and dilute hydrofluoric acid, and measuring the titanium in the resulting constant-volume solution by ICP mass spectrometry using an ICP mass spectrometer (Agilent 8800, manufactured by Agilent Technologies).

[0066] <Other Components> In addition to the above-mentioned EVA (A), high-ethylene saponified EVA (B), hydrotalcites (E), higher fatty acid metal salts (F), and titanium compounds (G), resins other than EVA (A) and high-ethylene saponified EVA (B) (e.g., polyolefin resins or other types of resins) and optional additives (hereinafter, these are referred to as "other components") may be blended into the resin composition (X) depending on various purposes, within the scope of not significantly impairing the effects of the present invention. One type of other component may be used alone, or two or more types may be used in any combination and ratio.

[0067] Examples of the additives include lubricants, plasticizers, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, and antiblocking agents.

[0068] Among the above additives, it is particularly preferable to use an antioxidant in combination, since this has the effect of reducing thermal degradation of the present resin composition (X).

[0069] <Antioxidant> Examples of the antioxidant include the following, and at least one of them can be selected. Hindered phenol compounds: dibutylhydroxytoluene, 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, 4,4'-thiobis-(6-t-butylphenol), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, N,N'-hexamethylene-bis(3,5-di-t-butyl-4'-hydroxy-hydrocinnamamide), 1,3,5- Trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5- Di-t-butylanilino)-1,3,5-triazine, 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, bis(3,5-di-t-butyl-4-hydroxybenzylphosphonate ethyl)calcium, tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanate Nurate, 2,4-bis[(octylthio)methyl]-o-cresol, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-t-pentylphenyl)ethyl]-4,6-di-t-pentylphenyl acrylate, 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro(5.5)undecane, etc.; Phosphite compounds: triaryl phosphites such as triphenyl phosphite, tris(p-nonylphenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite, etc.; alkylaryl phosphites such as monoalkyl diphenyl phosphites such as diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, and dialkyl monophenyl phosphites such as phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, etc.; trialkyl phosphites such as triisooctyl phosphite, tristearyl phosphite, etc.; bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, etc.; Thioether compounds: pentaerythritol tetrakis-(β-laurylthiopropionate), tetrakis[methylene-3-(dodecylthio)propionate]methane, bis[2-methyl-4-{3-n-alkylthiopropionyloxy}-5-t-butylphenyl]sulfide, dilauryl-3,3'-thiodipropionate, dimystyryl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythryl-tetrakis(3-laurylthiopropionate), ditridecyl-3,3'-thiodipropionate, 2-mercaptobenzimidazole, etc.; Hindered amine compounds: polycondensation product of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpentyl ether, poly{[6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]}, N,N'-bis(3-aminopropyl)ethylenediamine and 2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensates, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl) and the like; benzotriazole compounds: 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3 ,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, methyl-3-[3-t-butyl-5-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate-polyethylene glycol condensate, hydroxyphenylbenzotriazole derivatives, 2-[2-hydroxy-3-(3,4,5,6-tetra-hydrophthalimido-methyl)-5-methylphenyl]benzotriazole, etc.; Benzophenone compounds: 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, etc.; These antioxidants can be used in any form, such as powder, granules, liquid, paste, emulsion, etc.

[0070] Among the above antioxidants, hindered phenol antioxidants are preferred, and in particular, pentaerythritol-tetrakis-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate and octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate are preferably used because they have an excellent effect of reducing thermal degradation of the resin composition (X) and do not inhibit the effect of the present invention (inhibition of discoloration of the regrind layer).

[0071] When the antioxidant is used, the content thereof is, for example, typically 0.001 to 10% by mass, preferably 0.01 to 5% by mass, and particularly preferably 0.05 to 1% by mass, relative to 100% by mass of the EVA (A). When the content of the antioxidant is at least the lower limit, thermal degradation of the resin composition (X) tends to be reduced, and when the content is at most the upper limit, the appearance of the obtained molded article tends to be good, and the discoloration prevention effect and mechanical properties tend to be good.

[0072] When the present resin composition (X) contains the above-mentioned "other components", the total content thereof is usually 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less, based on the present resin composition (X).

[0073] [Method for producing resin composition (X)] The resin composition (X) can be produced by mixing the essential components EVA (A) and high-ethylene saponified EVA (B), and optionally hydrotalcites (E), higher fatty acid metal salts (F), titanium compounds (G), and other components. Examples of the mixing method include known methods such as a dry blending method, a melt mixing method in which a compound is obtained using a single-screw extruder or a twin-screw extruder, a solution mixing method, and an impregnation method, and these methods can be used in any combination.

[0074] [Resin composition (X)] The present resin composition (X) thus obtained is less likely to decompose under high temperature heating, has excellent thermal stability, and is also excellent in coloration suppression, compared to conventional resin compositions in which the EVA (A) and / or the saponified EVA (B) does not contain carbon-14.

[0075] The melt flow rate (MFR) (190°C, 2160 g load) of the resin composition (X) is usually 0.1 to 50 g / 10 min, preferably 0.5 to 30 g / 10 min, and particularly preferably 2 to 10 g / 10 min. The MFR can be measured in accordance with JIS K7120.

[0076] The water content of the resin composition (X) is usually 0.01 to 0.5% by mass, preferably 0.02 to 0.35% by mass, and particularly preferably 0.05 to 0.3% by mass.

[0077] The water content of the resin composition (X) is measured and calculated by the following method: The mass (W1) of the resin composition before drying is weighed on an electronic balance, dried in a hot air dryer at 150°C for 5 hours, and then cooled in a desiccator for 30 minutes, after which the mass (W2) is weighed and calculated using the following formula: Water content (mass%) = [(W1 - W2) / W1] x 100

[0078] The present resin composition (X) is prepared as a resin composition in various forms, such as pellets or powder, and is provided as a material for various molded articles and multilayer structures. As described above, the present resin composition (X) has excellent thermal stability and coloration suppression properties, and therefore, a molded article using the present resin composition (X) or a multilayer structure having a layer using the present resin composition (X) has the advantage that deterioration in quality, such as thermal degradation and coloration, is small even when recycled.

[0079] The resin composition (X) can be suitably used as a recovery aid (hereinafter referred to as the "recovery aid") for recovered resin materials containing the polyolefin resin (C) and EVOH (D) described below (for example, recovered materials such as scraps of laminates containing a polyolefin resin (C) layer and an EVOH (D) layer).

[0080] [Resin Composition for Recovery Aid] When the resin composition (X) is used as a resin composition for recovery aid, the content of the resin composition (X) is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 90% by mass or more, and particularly preferably 100% by mass, based on the total resin composition for recovery aid. The higher the content, the more likely it is to be effective as a recovery aid. In this specification, the recovery aid is an additive that is added when mixing a recovered resin containing polyolefin resin (C) and EVOH (D) (e.g., recovered scraps of a laminate containing a polyolefin resin layer and an EVOH layer), and is sometimes referred to as a compatibilizer or recycling aid. The recovery aid is also a powdered version of the resin composition for recovery aid.

[0081] [Molded Article] A molded article according to one embodiment of the present invention (hereinafter referred to as "the present molded article I") is obtained by molding the present resin composition (X).

[0082] Examples of the shape of the present molded product I include films, sheets, tapes, cups, trays, tubes, bottles, pipes, filaments, irregular cross-section extrudates, and various irregularly shaped products.

[0083] There are no particular limitations on the molding method for obtaining the present molded body I, and any molding method applicable to general resin compositions can be used. Examples of molding methods include extrusion molding, blow molding, injection molding, and thermoforming.

[0084] [Multilayer structure] A multilayer structure according to one embodiment of the present invention (hereinafter referred to as "the multilayer structure I") has a layer containing the resin composition (X). The multilayer structure I can be laminated with another substrate containing a thermoplastic resin other than the resin composition (X) as a main component to further impart strength or other functions. "Containing a thermoplastic resin as a main component" means a component that has a significant effect on the characteristics of the substrate, and the content of the thermoplastic resin in the substrate is 50% by mass or more, preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and may even be 100% by mass.

[0085] <<Second Aspect>> The present resin composition (Y) is either a resin composition (Y) containing EVA (A), a polyolefin resin (C), and an EVOH (D), wherein the EVA (A) contains 14 carbon atoms, or a resin composition (Y) containing EVA (A), a saponified EVA (B) having an ethylene content of more than 60 mol%, a polyolefin resin (C), and EVOH (D), wherein the EVA (A) and / or the saponified EVA (B) contains 14 carbon atoms.

[0086] <EVA (A)> Examples of the EVA (A) used in the present resin composition (Y) include the same ones as those explained in the first embodiment above.

[0087] The content of EVA (A) used in the present resin composition (Y) is usually 0.02 to 35 mass%, preferably 0.5 to 30 mass%, more preferably 0.8 to 15 mass%, and even more preferably 1.0 to 10 mass%, based on the present resin composition (Y). By setting the content of EVA (A) within the above range, it is possible to obtain a resin composition (Y) that is particularly excellent in thermal stability.

[0088] <Saponified EVA (B) having an ethylene content of more than 60 mol%> Examples of the saponified EVA (B) having an ethylene content of more than 60 mol% used in the present resin composition (Y) include the same as those described in the first embodiment above.

[0089] The content of the saponified EVA (B) having an ethylene content of more than 60 mol% used in the resin composition (Y) is usually 0.001 to 30 mass%, preferably 0.005 to 25 mass%, more preferably 0.05 to 10 mass%, and even more preferably 0.1 to 5 mass%, relative to the resin composition (Y). When the ethylene content is equal to or less than the upper limit, the resin composition (Y) tends to have excellent coloration suppression properties, and when the ethylene content is equal to or greater than the lower limit, the appearance of a molded article obtained from the resin composition (Y) tends to be good.

[0090] <Polyolefin Resin (C)> Examples of the polyolefin resin (C) (excluding EVA (A) and saponified EVA (B)) used in the resin composition (Y) include polyethylenes such as linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), very low-density polyethylene (VLDPE), medium-density polyethylene (MDPE), and high-density polyethylene (HDPE); polypropylene (PP); ionomers; ethylene-propylene (block or random) copolymers; ethylene-acrylic acid copolymers; ethylene-acrylic acid ester copolymers; ethylene-methacrylic acid copolymers; ethylene-methacrylic acid ester copolymers; propylene-α-olefin (α-olefin having 4 to 20 carbon atoms) copolymers; ethylene-α-olefin (α-olefin having 4 to 20 carbon atoms) copolymers; polybutene; polypentene; polymethylpentene; and other olefin homopolymers or copolymers, or blends thereof. These may be used alone or in combination of two or more. Among them, polyethylene, ethylene-propylene (block or random) copolymer, polypropylene (PP) and blends thereof are preferred in terms of economic efficiency and mechanical properties, and polyethylene, polypropylene (PP) and ethylene-propylene (block or random) copolymer are particularly preferred in terms of the particularly excellent effects of the present invention.

[0091] The melt flow rate (MFR) (230°C, 2160 g load) of the polyolefin resin (C) is usually 0.1 to 50 g / 10 min, and more preferably 0.5 to 30 g / 10 min. The MFR can be measured in accordance with JIS K7120.

[0092] The polyolefin resin (C) may contain known additives such as plasticizers, lubricants, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, crystal nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, and antiblocking agents, within a range that does not impair the effects of the present invention (for example, less than 30% by mass based on the total amount of the polyolefin resin (C)), and may also be blended with other polyolefin resins.

[0093] The content of the polyolefin resin (C) in the resin composition (Y) is usually 40 to 99.99 mass%, preferably 45 to 99.9 mass%, more preferably 50 to 99 mass%, and even more preferably 65 to 95 mass%, based on the total mass of the resin composition (Y). When the content of the polyolefin resin (C) is within the above range, the excellent effects of the present invention can be more fully obtained.

[0094] <EVOH (D)> The EVOH (D) used in the present resin composition (Y) is typically a water-insoluble thermoplastic resin obtained by saponifying an ethylene-vinyl ester copolymer, which is a copolymer of ethylene and a vinyl ester monomer, and typically has an ethylene content of 60 mol% or less. From an economical standpoint, vinyl acetate is typically used as the vinyl ester monomer.

[0095] The polymerization of ethylene and vinyl ester monomers can be carried out by any known polymerization method, such as solution polymerization, suspension polymerization, or emulsion polymerization, and solution polymerization using methanol as a solvent is generally used. The resulting ethylene-vinyl ester copolymer can also be saponified by a known method.

[0096] The EVOH (D) produced in this manner is mainly composed of structural units derived from ethylene and vinyl alcohol structural units, and usually contains a small amount of vinyl ester structural units that remain unsaponified.

[0097] As the vinyl ester monomer, vinyl acetate is typically used because of its commercial availability and the efficiency of impurity removal during production. Other vinyl ester monomers include, for example, aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caprate, vinyl laurate, vinyl stearate, and vinyl versatate, and aromatic vinyl esters such as vinyl benzoate. Aliphatic vinyl esters having typically 3 to 20 carbon atoms, preferably 4 to 10 carbon atoms, and particularly preferably 4 to 7 carbon atoms can be used. These can be used alone or in combination of two or more types.

[0098] The ethylene content in the EVOH (D) can be controlled by the ethylene pressure when copolymerizing the vinyl ester monomer with ethylene, and is usually 60 mol% or less. It is preferably 20 to 60 mol%, more preferably 25 to 50 mol%, and particularly preferably 25 to 35 mol%. When the ethylene content is equal to or greater than the lower limit, the gas barrier properties and melt moldability under high humidity conditions tend to be excellent, while when the ethylene content is equal to or less than the upper limit, the gas barrier properties tend to be excellent. The ethylene content can be measured in accordance with ISO 14663.

[0099] The degree of saponification of the vinyl ester component in EVOH (D) can be controlled by the amount, temperature, time, etc. of the saponification catalyst (usually an alkaline catalyst such as sodium hydroxide is used) used when saponifying the ethylene-vinyl ester copolymer, and is usually 90 to 100 mol%, preferably 95 to 100 mol%, and particularly preferably 99 to 100 mol%. Having a saponification degree within the above range tends to result in excellent gas barrier properties, thermal stability, moisture resistance, etc. The saponification degree of EVOH can be measured in accordance with JIS K6726 (however, EVOH is used as a solution uniformly dissolved in a water / methanol solvent).

[0100] The melt flow rate (MFR) (190°C, 2160 g load) of the EVOH (D) is typically 0.5 to 100 g / 10 min, preferably 1 to 50 g / 10 min, and particularly preferably 3 to 35 g / 10 min. When the MFR is below the upper limit, film-forming properties tend to be stable, while when the MFR is above the lower limit, viscosity tends to be stable and melt extrusion tends to be favorable. The MFR is an indicator of the degree of polymerization of the EVOH and can be adjusted by the amount of polymerization initiator and the amount of solvent used when copolymerizing ethylene and vinyl ester monomers. The MFR can be measured in accordance with JIS K7120.

[0101] The EVOH (D) may further contain structural units derived from the comonomers shown below within a range that does not impair the effects of the present invention (for example, 10 mol % or less based on the total EVOH).Examples of the comonomer include olefins such as propylene, 1-butene, and isobutene; hydroxy group-containing α-olefins such as 3-butene-1-ol, 3-butene-1,2-diol, 4-pentene-1-ol, and 5-hexene-1,2-diol, and derivatives thereof such as esters and acylation products; hydroxyalkylvinylidenes such as 2-methylenepropane-1,3-diol and 3-methylenepentane-1,5-diol; 1,3-diacetoxy-2-methylenepropane, 1,3-dipropionyloxy-2-methylenepropane, 1,3-dibutyryloyloxy-2-methylenepropane, and 1,3-dibutyryloyloxy-2-methylenepropane; hydroxyalkylvinylidene diacetates such as hydroxy-2-methylenepropane; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid, (anhydrous) maleic acid, (anhydrous) itaconic acid, or their salts or mono- or di-alkyl esters in which the alkyl group has 1 to 18 carbon atoms; acrylamide, N-alkylacrylamide in which the alkyl group has 1 to 18 carbon atoms, N,N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or its salts, acrylamidopropyldimethylamine or its acid salts or quaternary salts thereof, etc. Acrylamides; methacrylamides such as methacrylamide, N-alkylmethacrylamides in which the alkyl group has 1 to 18 carbon atoms, N,N-dimethylmethacrylamide, 2-methacrylamidopropanesulfonic acid or a salt thereof, methacrylamidepropyldimethylamine or an acid salt or a quaternary salt thereof; N-vinylamides such as N-vinylpyrrolidone, N-vinylformamide, and N-vinylacetamide; vinyl cyanides such as acrylonitrile and methacrylonitrile; alkyl vinyl ethers in which the alkyl group has 1 to 18 carbon atoms, hydroxy vinyl ethers, etc. vinyl ethers such as alkyl vinyl ether and alkoxyalkyl vinyl ether; halogenated vinyl compounds such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and vinyl bromide; vinyl silanes such as trimethoxyvinylsilane; halogenated allyl compounds such as allyl acetate and allyl chloride; allyl alcohols such as allyl alcohol and dimethoxyallyl alcohol; and comonomers such as trimethyl-(3-acrylamido-3-dimethylpropyl)-ammonium chloride and acrylamido-2-methylpropanesulfonic acid.These may be used alone or in combination of two or more.

[0102] In particular, EVOH having a primary hydroxyl group in the side chain is preferred because it has good secondary moldability while maintaining gas barrier properties, and among these, EVOH copolymerized with a hydroxy group-containing α-olefin is preferred, and EVOH having a 1,2-diol structure in the side chain is particularly preferred. In particular, when the EVOH has a primary hydroxyl group in the side chain, the content of the structural unit derived from the monomer having the primary hydroxyl group is preferably usually 0.1 to 20 mol %, more preferably 0.5 to 15 mol %, and particularly preferably 1 to 10 mol % of the EVOH.

[0103] The EVOH (D) may be "post-modified" such as urethanized, acetalized, cyanoethylated, or oxyalkylened.

[0104] Furthermore, the EVOH (D) may be a mixture of two or more kinds of EVOH, for example, EVOHs having different degrees of saponification, different degrees of polymerization, or different copolymerization components.

[0105] The content of the EVOH (D) in the resin composition (Y) is usually 0.1 to 30 mass %, preferably 0.3 to 25 mass %, more preferably 0.4 to 23 mass %, still more preferably 0.5 to 15 mass %, and particularly preferably 1.0 to 10 mass %, based on the total mass of the resin composition (Y). When the EVOH (D) is within the above range, the excellent effects of the present invention can be fully exhibited.

[0106] In addition to the above components, it is preferable to use, in the present resin composition (Y), for example, the above-mentioned hydrotalcites (E) and / or higher fatty acid metal salt (F) in combination, since this improves the effect of suppressing the generation of foreign matter (dye deposits) due to phase separation when a molded article is obtained using the present resin composition (Y). Among these, the hydrotalcites (E) are preferably used because they are particularly effective in suppressing discoloration when a regrind layer is obtained using recycled resin.

[0107] <Hydrotalcites (E)> Examples of the hydrotalcites (E) used in the present resin composition (Y) include the same hydrotalcites (E) as those described in the first embodiment above.

[0108] When the hydrotalcites (E) are contained in the resin composition (Y), their content is not particularly limited, but is usually 0.001 to 30% by mass, preferably 0.005 to 25% by mass, more preferably 0.05 to 10% by mass, and even more preferably 0.1 to 5% by mass, relative to the resin composition (Y). When the content is equal to or greater than the lower limit, molding stability and the effect of suppressing foreign matter and discoloration tend to be good, while when the content is equal to or less than the upper limit, the appearance of the molded product tends to be good, and the effect of suppressing discoloration and mechanical properties tend to be excellent.

[0109] <Higher fatty acid metal salt (F)> Examples of the higher fatty acid metal salt (F) used in the present resin composition (Y) include the same higher fatty acid metal salt (F) as described in the first embodiment above.

[0110] When the resin composition (Y) contains the higher fatty acid metal salt (F), its content is not particularly limited, but is usually 0.001 to 30 mass%, preferably 0.005 to 25 mass%, more preferably 0.05 to 10 mass%, and even more preferably 0.1 to 5 mass%, relative to the resin composition (Y). When the content is at least the lower limit, molding stability and the effect of suppressing foreign matter and discoloration tend to be easily obtained, while when the content is at most the upper limit, the appearance of the obtained molded article tends to be good, and the effect of suppressing discoloration and mechanical properties tend to be excellent.

[0111] When the hydrotalcites (E) and the higher fatty acid metal salt (F) are used in combination, the content of each of them is preferably within the above range.

[0112] Furthermore, in the resin composition (Y), a titanium compound (G) can be used together with the EVA (A), the high-ethylene EVA saponification product (B), the polyolefin resin (C), and the EVOH (D).

[0113] <Titanium Compound (G)> Examples of the titanium compound (G) used in the present resin composition (Y) include the same titanium compounds (G) as described in the first embodiment above.

[0114] When the titanium compound (G) is used, the content thereof in terms of metal is preferably 0.0001 to 20 mass%, more preferably 0.001 to 15 mass%, still more preferably 0.005 to 10 mass%, and particularly preferably 0.01 to 8 mass%, based on the total mass of the resin composition (Y).

[0115] <Other Components> In addition to the components described above, the resin composition (Y) may contain other resins different from the resins of the essential components described above, optional additives, etc. (hereinafter, these will be referred to as "other components") depending on various purposes, as long as the effects of the present invention are not significantly impaired. The other components may be used alone, or two or more may be used in any combination and ratio.

[0116] Examples of the additives include lubricants, plasticizers, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, and antiblocking agents.

[0117] Among the above additives, it is particularly preferable to use an antioxidant in combination, since this has the effect of reducing thermal degradation of the present resin composition (Y).

[0118] <Antioxidant> Examples of the antioxidant used in the present resin composition (Y) include the same antioxidants as those described in the first embodiment above.

[0119] When the antioxidant is used in the present resin composition (Y), the content thereof is, for example, usually 0.001 to 30 mass%, preferably 0.005 to 25 mass%, more preferably 0.05 to 10 mass%, and even more preferably 0.1 to 5 mass%, relative to the present resin composition (Y). When the content of the antioxidant is at least the lower limit, thermal degradation of the present resin composition (Y) tends to be easily reduced, and when it is at most the upper limit, the appearance of the obtained molded article tends to be good, and the discoloration prevention effect and mechanical properties tend to be excellent.

[0120] When the present resin composition (Y) contains the above-mentioned "other components," the total content thereof is usually 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less, relative to the present resin composition (Y).

[0121] [Method for Producing Resin Composition (Y)] The resin composition (Y) can be produced by mixing the essential components EVA (A), high-ethylene saponified EVA (B), polyolefin resin (C), EVOH (D), and optionally hydrotalcites (E), higher fatty acid metal salt (F), titanium compound (G), and other components. The resin composition (Y) can also be produced by mixing the polyolefin resin (C) and EVOH (D) with the resin composition (X). When the resin composition (X) contains hydrotalcites (E), higher fatty acid metal salt (F), and titanium compound (G), a resin composition (Y) with excellent thermal stability and coloration inhibition can be produced without adding hydrotalcites (E), higher fatty acid metal salt (F), or titanium compound (G).

[0122] Examples of the mixing method include known methods such as a dry blending method, a melt mixing method in which a compound is obtained using a single-screw extruder or a twin-screw extruder, a solution mixing method, an impregnation method, etc., and these can be combined in any desired manner. Note that the polyolefin resin (C) and EVOH (D) can be recycled resins obtained by pulverizing recovered scraps of a laminate containing a polyolefin resin layer and an EVOH layer.

[0123] [Resin composition (Y)] The resin composition (Y) thus obtained is less likely to decompose under high temperature heating, has excellent thermal stability, and is also excellent in coloration suppression, compared to conventional resin compositions in which the EVA (A) and / or the high-ethylene EVA saponification product (B) does not contain carbon-14.

[0124] The melt flow rate (MFR) of the resin composition (Y) (230°C, 2160 g load) is usually 0.1 to 50 g / 10 min, preferably 0.5 to 30 g / 10 min, and particularly preferably 2 to 10 g / 10 min. The MFR can be measured in accordance with JIS K7120.

[0125] The water content of the resin composition (Y) is usually 0.01 to 0.5% by mass, preferably 0.02 to 0.35% by mass, and particularly preferably 0.05 to 0.3% by mass.

[0126] The water content of the resin composition (Y) is measured and calculated by the following method: The mass (W1) of the resin composition before drying is weighed on an electronic balance, dried in a hot air dryer at 150°C for 5 hours, and then cooled in a desiccator for 30 minutes, after which the mass (W2) is weighed and calculated using the following formula: Water content (mass%) = [(W1 - W2) / W1] x 100

[0127] The resin composition (Y) is prepared as a resin composition in various forms, such as pellets or powder, and is provided as a material for various molded articles and multilayer structures. As described above, the resin composition (Y) has excellent thermal stability and coloration suppression properties, and therefore, a molded article using the resin composition (Y) or a multilayer structure having a layer using the resin composition (Y) has the advantage that deterioration in quality, such as thermal degradation and coloration, is small even when recycled.

[0128] Furthermore, as already described, the polyolefin resin (C) and the EVOH (D) may be derived solely from recycled materials such as scraps of laminates containing a polyolefin resin (C) layer and an EVOH (D), etc. When the present resin composition (Y) is such a recycled resin composition, as described above, deterioration in quality such as thermal degradation and coloration is small, and therefore a molded article or multilayer structure having excellent quality can be provided, which is preferable.

[0129] [Molded Article] A molded article according to one embodiment of the present invention (hereinafter referred to as "the present molded article II") is obtained by molding the present resin composition (Y).

[0130] Examples of the shape of the present molded product II include films, sheets, tapes, cups, trays, tubes, bottles, pipes, filaments, irregular cross-section extrudates, and various irregularly shaped products.

[0131] The molding method for obtaining the present molded article II is not particularly limited, and any molding method applicable to general resin compositions can be used, such as extrusion molding, blow molding, injection molding, thermoforming, etc.

[0132] [Multilayer structure] A multilayer structure according to one embodiment of the present invention (hereinafter referred to as "the multilayer structure II") has at least one layer containing the resin composition (Y). The multilayer structure II can be laminated with another substrate containing the thermoplastic resin of the resin composition (Y) as a main component to further impart strength or other functions. Note that "containing a thermoplastic resin as a main component" means a component that has a significant effect on the characteristics of the substrate, and the content of the thermoplastic resin in the substrate is 50% by mass or more, preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and may even be 100% by mass.

[0133] In the multilayer structure II, the layer containing the resin composition (Y) is preferably a layer (regrind layer) formed using the resin composition (Y) (= recycled resin composition) containing the polyolefin resin (C) and EVOH (D) derived from scraps or the like of a laminate containing a polyolefin resin (C) layer and an EVOH (D) layer. Such a multilayer structure having a regrind layer will be described below.

[0134] [Regrind Layer] The recycled materials of the laminate containing the polyolefin resin (C) layer and the EVOH (D) layer used to obtain the regrind layer according to one embodiment of the present invention are scraps, unnecessary parts such as edges, and defective products collected during the production process, or waste collected after the molded body has been used for various purposes. These recycled materials can be reused to prepare the present resin composition (Y), which can then be used to obtain the regrind layer.

[0135] The recovered material used for recycling is generally scraps related to one molded product, but scraps related to two or more types of molded products may also be used as the recovered material.

[0136] To obtain the regrind layer, for example, the recycled material (a composition containing polyolefin resin (C) and EVOH (D)) is appropriately combined with other components of the present resin composition (Y), such as EVA (A), high-ethylene saponified EVA (B), and other optional components, and, if necessary, additional polyolefin resin (C) and EVOH (D) are added. Alternatively, the resin composition (X) is added to the recycled material (a composition containing polyolefin resin (C) and EVOH (D)). These are uniformly mixed to obtain the present resin composition (Y), which is a recycled resin composition. The present multilayer structure having a regrind layer can then be obtained by melt-molding the present resin composition (Y).

[0137] First, in order to subject the recovered laminate to melt molding again using an extruder or the like, it is preferable to pulverize the recovered laminate.

[0138] The recovered material can be pulverized using a known pulverizer. The shape and particle size of the pulverized product, as measured in accordance with the "5.3 Apparent Density" test method of JIS-K6891, are typically 0.25 to 0.85 g / mL, preferably 0.3 to 0.7 g / mL, and particularly preferably 0.35 to 0.6 g / mL. When the apparent density is equal to or greater than the lower limit, the dispersion of EVOH in the regrind layer is improved, and the resulting molded article tends to have excellent melt-moldability and mechanical properties. When the density is equal to or less than the upper limit, the occurrence of feeding problems in the extruder tends to be suppressed, and the resulting molded article tends to have excellent melt-moldability of the regrind layer.

[0139] The apparent density can be controlled by adjusting the shape of the grinding blade of the grinding machine, the rotation speed of the grinding blade, the grinding processing speed, the size of the openings of the mesh used, and the like.

[0140] The content of EVOH in the recycled material is usually 0.1 to 30% by weight based on the total weight of the recycled material, and in order to particularly exhibit the effects of the present resin composition (Y), it is preferably set to 0.3 to 25% by weight, particularly 0.5 to 20% by weight. In the present invention, the improving effect is exhibited for recycled materials of any content, but the improving effect is particularly exhibited within the above range.

[0141] The content of EVOH in the recycled material depends on the thickness ratio of the EVOH layer in the laminate, and if the EVOH content is too low, the content may be adjusted by mixing an appropriate amount of virgin EVOH of the same or a different type, as necessary. Conversely, if the EVOH content is too high, it is practically preferable to adjust the content by mixing an appropriate amount of virgin EVOH of the same or a different type, polyolefin resin.

[0142] Next, the remaining components of the present resin composition (Y), such as EVA (A) and high-ethylene EVA saponification product (B), are blended with the pulverized recovered material. Alternatively, the resin composition (X) is blended. The blending can be carried out using a known blending device such as a rocking mixer, ribbon blender, super mixer, or line mixer.

[0143] In this manner, the present resin composition (Y), which is a recycled resin composition containing recovered materials, can be obtained.

[0144] The present resin composition (Y) can be used to obtain a present multilayer structure having at least one regrind layer. The present multilayer structure having a regrind layer is generally preferably a multilayer structure comprising, in addition to the regrind layer, a polyolefin resin layer, an EVOH layer, and optionally an adhesive resin layer. Note that the polyolefin resin layer, the EVOH layer, and the adhesive resin layer do not contain EVA (A).

[0145] Examples of the layer configuration of the regrind layer-containing multilayer structure include polyolefin resin layer / regrind layer / adhesive resin layer / EVOH layer, polyolefin resin layer / regrind layer / adhesive resin layer / EVOH layer / adhesive resin layer / polyolefin resin layer, polyolefin resin layer / regrind layer / adhesive resin layer / EVOH layer / adhesive resin layer / regrind layer / polyolefin resin layer, and further regrind layer / EVOH layer, regrind layer / adhesive resin layer / EVOH layer, regrind layer / adhesive resin layer / EVOH layer / adhesive resin layer / EVOH layer, regrind layer / adhesive resin layer / EVOH layer / adhesive resin layer / polyolefin resin layer, regrind layer / adhesive resin layer / EVOH layer / adhesive resin layer / regrind layer / polyolefin resin layer, polyolefin resin layer / adhesive resin layer / EVOH layer / regrind layer / EVOH layer / adhesive resin layer / polyolefin resin layer, and the like.

[0146] The thickness of each layer of the regrind layer-containing multilayer structure cannot be generalized depending on the layer configuration, type of polyolefin resin, intended use, container shape, required physical properties, etc., but the regrind layer is usually 5 to 5,000 μm, and more preferably 30 to 1,000 μm. The EVOH layer is usually 5 to 500 μm, and more preferably 10 to 200 μm. The polyolefin resin layer is usually 5 to 5,000 μm, and more preferably 30 to 1,000 μm. In this case, if an adhesive resin layer is present, the adhesive resin layer is usually 5 to 400 μm, and more preferably 10 to 150 μm.

[0147] The thickness ratio of the regrind layer to the polyolefin resin layer is usually 1 / 5 to 10 / 1, and preferably 1 / 2 to 5 / 1. The thickness ratio of the regrind layer to the EVOH layer is usually 1 / 1 to 100 / 1, and preferably 5 / 1 to 20 / 1.

[0148] The regrind layer-containing multilayer structure can be formed, for example, by the same method as the method for forming the laminate to be recycled. Specifically, it can be produced by the following method using a polyolefin resin used in the polyolefin resin layer of the laminate to be recycled, an EVOH used in the EVOH layer, and an adhesive resin used in the adhesive resin layer.

[0149] Examples of methods for obtaining the multilayer structure include a method of melt-extrusion laminating the present resin composition (Y) onto an EVOH film, sheet, etc., a method of melt-extrusion laminating the present resin composition (Y) onto a substrate consisting of a polyolefin layer, a method of co-extruding the present resin composition (Y) with an EVOH or polyolefin resin, and a method of dry-laminating a film, sheet, etc. of an EVOH or polyolefin resin with a film, sheet, etc. of the present resin composition (Y) using an adhesive such as an organic titanium compound, an isocyanate compound, a polyester compound, a polyurethane compound, etc. The melt molding temperature during the melt extrusion is usually in the range of 150 to 300°C.

[0150] The above-mentioned regrind layer-containing multilayer structure can be used as is in various shapes, but it can also be subjected to a heat stretching treatment to further improve the physical properties of this laminate and to form it into any desired container shape.

[0151] Here, the heat stretching treatment means an operation of forming a thermally uniformly heated film, sheet or parison-like multilayer structure into a shape such as a cup, tray, tube or bottle by means of a chuck, plug, vacuum force, compressed air force, blow or the like.

[0152] Examples of the stretching method used in the heat stretching treatment include roll stretching, tenter stretching, tubular stretching, stretch-blow, vacuum forming, pressure forming, and vacuum-pressure forming. In the case of biaxial stretching, either simultaneous biaxial stretching or sequential biaxial stretching can be used. The stretching temperature is usually 60 to 170°C, and preferably about 80 to 160°C. Either uniaxial stretching or biaxial stretching may be used, and stretching at as high a ratio as possible results in better physical properties and a stretched molded product with excellent gas barrier properties that is free from pinholes, cracks, stretching unevenness, thickness deviation, delamination, etc. during stretching can be obtained.

[0153] In the present multilayer structure, the recycled material used for the regrind layer may also have a regrind layer therein, and a laminate having at least one regrind layer containing such recycled material can be molded using the same resin as the recycled material and the same method as the recycled material. That is, a laminate having at least one regrind layer (recycled product) can be produced using a resin composition obtained from the recycled material, and the recycled material from that molded product can be used again as the regrind layer of a similar laminate (recycled product).

[0154] In addition, other forms of the present multilayer structure include: [1] using recycled laminates having multiple different types of polyolefin resin layers or multiple different types of EVOH layers, and / or recycled laminates of multiple different types, in the same regrind layer; and [2] using recycled materials in the regrind layer of a laminate having different types of polyolefin resin and EVOH from the polyolefin resin and EVOH contained in the recycled materials.

[0155] Furthermore, to improve moldability, physical properties, and the like, each layer of the present multilayer structure may also contain additives such as antioxidants, heat stabilizers, light stabilizers, lubricants, antistatic agents, crystal nucleating agents, plasticizers, colorants, ultraviolet absorbers, surfactants, antibacterial agents, desiccants, oxygen absorbers, antiblocking agents, slip agents, inorganic or organic fillers, and the like, within limits that do not impair the effects of the present invention.

[0156] Furthermore, the present multilayer structure may be subjected to heat treatment, cooling treatment, rolling treatment, printing treatment, dry lamination treatment, solution or melt coating treatment, bag making, deep drawing, box processing, tube processing, splitting processing, etc., as necessary.

[0157] The multilayer structure, whether recycled or re-recycled, is useful as a variety of containers for general foods, condiments such as mayonnaise and dressings, fermented foods such as miso, fatty foods such as salad oil, soups, beverages, cosmetics, pharmaceuticals, detergents, toiletries, industrial chemicals, pesticides, fuels, etc., but is particularly useful as bottle-shaped or tube-shaped containers for semi-solid foods and condiments such as mayonnaise, ketchup, sauces, miso, wasabi, mustard, and sauces for grilled meat, etc., and liquid beverages and condiments such as salad oil, mirin, sake, beer, wine, juice, tea, sports drinks, mineral water, and milk; cup-shaped containers for semi-solid foods and condiments such as fruit, jelly, pudding, yogurt, mayonnaise, miso, processed rice, cooked foods, and soup; and tray-shaped containers for raw meat, processed meat products (ham, bacon, sausages, etc.), cooked rice, and pet food.

[0158] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not depart from the gist of the invention. Unless otherwise specified, "parts" and "%" below refer to mass standards. Prior to the examples, the following components were prepared.

[0159] [EVA (A)] Carbon-14-containing EVA (A1): Biomass-derived EVA (SVT2145R, manufactured by Braskem), ethylene content 95 mol%, vinyl acetate content 14 mass%, MFR (190°C, load 2160 g) 2.1 g / 10 min, biobased content 88% Petroleum-derived EVA (A2): Petroleum-derived EVA (Ultrathene 630, manufactured by Tosoh Corporation), ethylene content 95 mol%, vinyl acetate content 15 mass%, MFR (190°C, load 2160 g) 1.5 g / 10 min, density 0.936 g / cm 3[EVA saponification product (B)] EVA saponification product (B1): EVA saponification product derived from petroleum raw materials (Mersen H0051K, manufactured by Tosoh Corporation), ethylene content 89 mol%, saponification degree 99 mol%, MFR (190°C, load 2160 g) 6.5 g / 10 min [Polyolefin resin (C)] Polyolefin resin (C1): Polypropylene (Novatec (registered trademark) EA9, manufactured by Japan Polypropylene Co., Ltd.), MFR (230°C, load 2160 g) 0.5 g / 10 min [Adhesive resin] Maleic anhydride grafted ethylene-propylene random copolymer, MFR (230°C, load 2160 g) 3.2 g / 10 min [EVOH (D)] EVOH (D1): EVOH (ethylene content 32 mol%, saponification degree 99.9 mol%), MFR (190°C, load 2160 g) 3.8 g / 10 min [Hydrotalcites (E)] Hydrotalcites (E1): Hydrotalcite solid solution (ZHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd.) [Higher fatty acid metal salt (F)] Higher fatty acid metal salt (F1): Calcium stearate (Nissan Calcium Stearate S, manufactured by NOF Corporation) [Titanium compound (G)] Titanium compound (G1): Titanium oxide (manufactured by Wako Pure Chemical Industries, Ltd.) [Antioxidant] Pentaerythritol tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate) (Irganox 1010, manufactured by Ciba Specialty Chemicals)

[0160] <<First Aspect>> <Example 1-1> 85 parts of carbon-14-containing EVA (A1), 5 parts of saponified EVA (B1), 5 parts of hydrotalcites (E1), 5 parts of a higher fatty acid metal salt (F1), and 0.05 parts of an antioxidant were dry-blended all at once, and then fed to a twin-screw kneader at a rate of 8 kg / hour using a mass feeder. Subsequently, the resulting mixture was strand-cut using a drum pelletizer to prepare a pellet-shaped resin composition (X). The kneading conditions were as follows: [Kneading conditions] Twin-screw extruder: diameter 20 mm L / D = 48 (manufactured by Toshiba Machine Co., Ltd.) Extruder setting temperatures (°C): C1 / C2 / C3 / C4 / C5 / C6 / H = 120 / 150 / 160 / 160 / 170 / 170 / 170 Screw rotation speed: 250 rpm Take-up speed: 12 m / min

[0161] Examples 1-2 to 1-4, Comparative Examples 1-1 and 1-2 Resin compositions (X) of Examples 1-2 to 1-4 and Comparative Examples 1-1 and 1-2 were prepared in the same manner as in Example 1, except that the types and amounts of each component were changed as shown in Table 1 below.

[0162] The resin compositions (X) obtained in Examples 1-1 to 1-4 and Comparative Examples 1-1 and 1-2 were evaluated for thermal stability and coloration suppression, as described below. The results are shown in Table 1 below.

[0163] [Evaluation of Thermal Stability (10% Loss Temperature)] Using 5 mg of the obtained pellet-like resin composition (X), the temperature at which the resin composition (X) had decreased to 95% of its mass before measurement (10% loss temperature) was measured using a thermogravimetric analyzer (Perkin Elmer, Pyris 1 TGA) under conditions of a nitrogen atmosphere, an air flow rate of 20 mL / min, and a temperature range of 30 to 550°C. A higher value indicates that the resin composition (X) decomposes more slowly, and therefore indicates that the resin composition (X) has better thermal stability. Evaluation was also performed based on the following criteria. A (excellent): 10% decrease in temperature is 370.0°C or higher B (very good): 10% decrease in temperature is 367.5°C or higher and lower than 370.0°C C (good): 10% decrease in temperature is 362.5°C or higher and lower than 367.5°C D (poor): 10% decrease in temperature is lower than 362.5°C

[0164] [Evaluation of Coloration Inhibition (YI Value Ratio)] The pellet-like resin composition (X) was pulverized at 650 rpm using a pulverizer (SKR16-240, manufactured by Sometani Sangyo Co., Ltd.) to obtain pulverized material of 1 to 5 mm square. The obtained pulverized material was filled into a cylinder with an inner diameter of 32 mm and a height of 30 mm, and the pulverized material was completely worn out. The yellow index (YI value) before heating was measured using a spectrophotometer (manufactured by Nippon Denshoku Industries Co., Ltd.). The pulverized material was then heated in an oven under air at 60°C for 3 days, and the YI value after heating was measured in the same manner. The ratio of the YI value after heating to the YI value before heating was calculated. The larger this value, the more yellow the resin composition (X) was colored after heating. Evaluation was also performed based on the following criteria. A (excellent): YI value ratio is 1.0 or less B (very good): YI value ratio is more than 1.0 and 3.5 or less C (good): YI value ratio is more than 3.5 and 5.0 or less D (poor): YI value ratio is more than 5.0

[0165]

[0166] From the results in Table 1, it can be seen that the resin compositions (X) of Examples 1-1 to 1-4, which used the carbon-14-containing EVA (A1) as the EVA, have improved thermal stability compared to Comparative Examples 1-1 and 1-2, which used the petroleum-derived EVA (A2). Furthermore, a comparison between Example 1-2 and Comparative Example 1-1 reveals that the use of the carbon-14-containing EVA (A1) also improves coloration suppression. The reason for this is that the carbon-14 ( 14 It is believed that the C-containing EVA has stronger bond energy due to the primary isotope effect, resulting in slower decomposition and improved thermal stability, as well as a synergistic effect with the hydrotalcites (E1) and the higher fatty acid metal salt (F1). Furthermore, it can be seen that the effects of the above-mentioned Examples 1-1 to 1-4, such as excellent thermal stability and coloration inhibition, can be similarly achieved even when the blending ratio or type of each component is changed. Furthermore, Example 1-1 and Comparative Example 1-2 show that when the resin composition (X) contains a titanium compound (G1), the use of a carbon-14-containing EVA (A1) instead of the petroleum-derived EVA (A2) improves thermal stability and yellowing inhibition, and furthermore, the products of Examples 1-1 to 1-4 have excellent coloration inhibition.

[0167] <<Second Aspect>> <Example 2-1> A recovered laminate comprising a layer of polyolefin resin (C1) and a layer of EVOH (D1) laminated via an adhesive resin layer was pulverized, and the resulting pulverized material was mixed together with a carbon-14-containing EVA (A1), a saponified EVA (B1), a hydrotalcite (E1), and a higher fatty acid metal salt (F1) by dry blending in proportions such that the components would yield the composition shown in Table 2. The mixture was then fed into a twin-screw kneader at a rate of 8 kg / hour using a mass feeder, and then strand-cut using a drum pelletizer to prepare pellets of a resin composition (Y). The kneading conditions were as follows: [Kneading conditions] Twin-screw extruder: diameter 20 mm L / D = 48 (manufactured by Toshiba Machine Co., Ltd.) Extruder setting temperatures (°C): C1 / C2 / C3 / C4 / C5 / C6 / H = 120 / 150 / 160 / 160 / 170 / 170 / 170 Screw rotation speed: 250 rpm Take-up speed: 12 m / min

[0168] Examples 2-2 to 2-5, Comparative Example 2-1 Resin compositions (Y) of Examples 2-2 to 2-5 and Comparative Example 2-1 were prepared in the same manner as in Example 2-1, except that the types and amounts of each component were changed as shown in Table 2 below.

[0169] The resin compositions (Y) obtained in Examples 2-1 to 2-5 and Comparative Example 2-1 were evaluated for thermal stability and coloration suppression, as described below. The results are shown in Table 2 below.

[0170] [Evaluation of Thermal Stability (5% Loss Temperature)] Using 5 mg of the obtained pellet-like resin composition (Y), the temperature at which the resin composition (Y) had decreased to 95% of its mass before measurement (5% loss temperature) was measured using a thermogravimetric analyzer (Perkin-Elmer, Pyris 1 TGA) under conditions of a nitrogen atmosphere, an airflow rate of 20 mL / min, and a temperature range of 30 to 550°C. A higher value indicates that the resin composition (Y) decomposes more slowly, and therefore indicates that the resin composition (Y) has better thermal stability. Evaluation was also performed based on the following criteria. A (excellent): 5% decrease in temperature is 380.0°C or higher B (very good): 5% decrease in temperature is 375.0°C or higher and lower than 380.0°C C (good): 5% decrease in temperature is 372.5°C or higher and lower than 375.0°C D (poor): 5% decrease in temperature is lower than 372.5°C

[0171] [Evaluation of Coloration Inhibition (Difference in YI Value)] The pellet-like resin composition (Y) was pulverized at 650 rpm using a pulverizer (SKR16-240, manufactured by Sometani Sangyo Co., Ltd.) to obtain pulverized material of 1 to 5 mm square. The obtained pulverized material was filled into a cylinder with an inner diameter of 32 mm and a height of 30 mm, and the pulverized material was completely worn out. The yellow index (YI value) before heating was measured using a spectrophotometer (manufactured by Nippon Denshoku Industries Co., Ltd.). The pulverized material was then heated in an oven under air at 60°C for 3 days, and the YI value after heating was measured in the same manner. The difference in the YI value after heating relative to the YI value before heating was calculated. The larger this value, the more yellow the resin composition (Y) was colored after heating. Evaluation was also performed based on the following criteria. A (excellent): YI value ratio is less than 0.20 B (very good): YI value ratio is 0.20 or more and less than 0.30 C (good): YI value ratio is 0.30 or more and less than 0.40 D (poor): YI value ratio is 0.40 or more

[0172]

[0173] From the results in Table 2, it can be seen that the resin compositions (Y) of Examples 2-1 to 2-5, which used the carbon number 14-containing EVA (A1) together with the components (C) to (E) contained in the recycled laminates, etc., have improved thermal stability and coloration suppression properties compared to Comparative Example 2-1, which used the petroleum-derived EVA (A2). The reason for this is that the carbon number 14 ( 14 It is believed that the C-containing EVA has stronger bond energy due to the primary isotope effect, which slows decomposition and improves thermal stability, and also provides a synergistic effect with the hydrotalcites (E1) and the higher fatty acid metal salt (F1). In particular, comparing Example 2-1 with Comparative Example 2-1, it is clear that the use of the carbon-14-containing EVA (A1) significantly improves coloration inhibition compared to the use of the petroleum-derived EVA (A2). It is also clear that the effects of the products of Examples 2-1 to 2-5, such as excellent thermal stability and coloration inhibition, can be similarly obtained even when the blending ratio and type of each component are changed.

[0174] Although the above examples show specific embodiments of the present invention, the examples are merely illustrative and should not be construed as limiting. Various modifications that are obvious to those skilled in the art are intended to fall within the scope of the present invention.

[0175] The resin composition (X) can exhibit higher thermal stability and coloration suppression than resin compositions using petroleum-derived EVA. Therefore, molded articles made from the resin composition (X) and multilayer structures having a layer containing the resin composition (X) are useful as packaging materials for various packaging containers and food packaging. Furthermore, the resin composition (X) is useful as a recovery aid for recycled resin products containing polyolefin resin and EVOH. Furthermore, the resin composition (Y) can exhibit higher thermal stability and coloration suppression than resin compositions using petroleum-derived EVA. Therefore, molded articles made from the resin composition (Y) and multilayer structures having a layer containing the resin composition (Y) are useful as packaging materials for various packaging containers and food packaging. In particular, the resin composition (Y) is useful as a recycled resin composition made from recycled resin products containing polyolefin resin and EVOH.

Claims

1. A resin composition (X) containing an ethylene-vinyl acetate copolymer (A), wherein the ethylene-vinyl acetate copolymer (A) contains 14 carbon atoms.

2. Resin composition (X) containing an ethylene-vinyl acetate copolymer (A) and a saponified ethylene-vinyl acetate copolymer (B) having an ethylene content of more than 60 mol%, wherein the ethylene-vinyl acetate copolymer (A) and / or the saponified ethylene-vinyl acetate copolymer (B) contains 14 carbon atoms.

3. The resin composition (X) according to claim 2, wherein the ethylene-vinyl acetate copolymer (A) contains 14 carbon atoms.

4. The resin composition (X) according to claim 2, wherein the ethylene-vinyl acetate copolymer (A) and / or the saponified ethylene-vinyl acetate copolymer (B) having an ethylene content of more than 60 mol % have a biobased degree of 1 to 100%.

5. The resin composition (X) according to claim 1 or 2, wherein the ethylene-vinyl acetate copolymer (A) has a bio-based content of 1 to 100%.

6. The resin composition (X) according to claim 1 or 2, wherein the ethylene-vinyl acetate copolymer (A) has a bio-based content of 40 to 100%.

7. The resin composition (X) according to claim 1 or 2, wherein the ethylene content of the ethylene-vinyl acetate copolymer (A) is 60 to 98 mol %.

8. A resin composition for use as a recovery aid, comprising the resin composition (X) according to claim 1 or 2.

9. Use of the resin composition (X) according to claim 1 or 2 as a recovery aid.

10. A recovery aid comprising the resin composition (X) according to claim 1 or 2.

11. The resin composition (X) according to claim 1 or 2, further comprising a polyolefin resin (C).

12. The resin composition (X) according to claim 1 or 2, further comprising an ethylene-vinyl alcohol copolymer (D) having an ethylene content of 60 mol % or less.

13. A resin composition (Y) containing an ethylene-vinyl acetate copolymer (A), a polyolefin resin (C), and an ethylene-vinyl alcohol copolymer (D), wherein the ethylene-vinyl acetate copolymer (A) contains 14 carbon atoms.

14. Resin composition (Y) containing an ethylene-vinyl acetate copolymer (A), a saponified ethylene-vinyl acetate copolymer (B) having an ethylene content of more than 60 mol%, a polyolefin resin (C), and an ethylene-vinyl alcohol copolymer (D), wherein the ethylene-vinyl acetate copolymer (A) and / or the saponified ethylene-vinyl acetate copolymer (B) contains 14 carbon atoms.

15. The resin composition (Y) according to claim 13 or 14, further comprising a hydrotalcite (E).

16. The resin composition (Y) according to claim 13 or 14, further comprising a metal salt of a higher fatty acid (F).

17. Resin composition (Y) according to claim 16, wherein the higher fatty acid metal salt (F) is at least one selected from the group consisting of higher fatty acid calcium salts, higher fatty acid magnesium salts, and higher fatty acid zinc salts.

18. The resin composition (Y) according to claim 13 or 14, further comprising a titanium compound (G).

19. The resin composition (Y) according to claim 18, wherein the titanium compound (G) is titanium oxide.

20. A regrind layer comprising the recovery aid of claim 10.

21. A multi-layer structure comprising a regrind layer according to claim 20.

22. The multilayer structure according to claim 21, further comprising a layer containing a polyolefin resin (but not containing an ethylene-vinyl acetate copolymer (A)).

23. The multilayer structure of claim 21, further comprising an adhesive resin layer different from said regrind layer (but not including ethylene-vinyl acetate copolymer (A)).

24. A package comprising the multi-layer structure of claim 21.

25. A food package comprising the multi-layer structure of claim 21.

26. A method for producing a recovery aid, comprising a step of mixing an ethylene-vinyl acetate copolymer (A) and a saponified ethylene-vinyl acetate copolymer (B) having an ethylene content of more than 60 mol%, wherein the ethylene-vinyl acetate copolymer (A) and / or the saponified ethylene-vinyl acetate copolymer (B) contain carbon-14.

27. A manufacturing method for obtaining a regrind layer, comprising a step of mixing a polyolefin resin (C), an ethylene-vinyl alcohol copolymer (D), an ethylene-vinyl acetate copolymer (A), and a saponified ethylene-vinyl acetate copolymer (B) having an ethylene content of more than 60 mol%, wherein the ethylene-vinyl acetate copolymer (A) and / or the saponified ethylene-vinyl acetate copolymer (B) contains carbon-14.

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