Resin composition, resin composition for recovery additive, use in recovery additive, recovery material layer, multilayer structure, packaging body, food package, recovery additive

Abstract

Provided is a resin composition having excellent thermal stability and coloring inhibition properties. The resin composition (X) contains an ethylene-vinyl acetate copolymer (A), and the ethylene-vinyl acetate copolymer (A) contains carbon 14.

Description

Technical Field

[0001] This invention relates to resin compositions, resin compositions for recycling additives, their use in recycling additives, recycled material layers, multilayer structures, packaging bodies, food packaging, and methods for manufacturing recycling additives and recycled material layers. Background Technology

[0002] Previously, ethylene-vinyl alcohol copolymers (hereinafter referred to as "EVOH") with an ethylene content of 60 mol% or less were mainly used as food packaging materials due to their excellent gas barrier properties and transparency. Sheets, films, etc., used as the above-mentioned food packaging materials can also be made from EVOH alone, but they are also used by blending with other thermoplastic resins to improve physical properties, or by forming multilayer structures with layers formed of polyolefin resins to impart other functions.

[0003] In addition, recently, in order to reduce the environmental impact, used resin products, resin scraps, ends, or defective products generated during the manufacturing process of resin products are recycled and reused as resin compositions containing EVOH and polyolefins.

[0004] However, when resin compositions containing EVOH and polyolefins are repeatedly melt-molded, the quality of the resin composition deteriorates due to the effects of the thermal process.

[0005] Therefore, as a resin composition that is not easily affected even when repeatedly subjected to thermal processes, a resin composition comprising an ethylene-vinyl acetate copolymer (hereinafter referred to as "EVA") and an EVA saponified compound with an ethylene content of more than 60 mol% has been proposed (see Patent Document 1 below).

[0006] On the other hand, as a resin composition that reduces carbon emissions compared to materials generated using only fossil fuel sources, a resin composition containing EVA derived from biomass resources has been proposed (see Patent Document 2 below).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: International Publication No. 2009 / 041440

[0010] Patent Document 2: Japanese Patent Publication No. 2021-536526 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] The present invention provides a resin composition with excellent thermal stability and suppressed coloration.

[0013] Solution for solving the problem

[0014] In order to address the above-mentioned problems, the inventors conducted in-depth research and discovered that in resin compositions containing EVA and EVA saponification, by using EVA and / or EVA saponification containing carbon-14 (… 14 A resin composition containing C (radioactive carbon-14, half-life 5730 years) can solve the above-mentioned problems.

[0015] That is, the present invention has the following aspects.

[0016] [1] A resin composition (X) containing EVA (A) comprising carbon 14.

[0017] [2] A resin composition (X) comprising EVA (A) and EVA saponified (B) having an ethylene content greater than 60 mol%, wherein the EVA (A) and / or the EVA saponified (B) comprises carbon-14.

[0018] [3] The resin composition (X) according to [2], wherein the EVA (A) contains carbon 14.

[0019] [4] According to the resin composition (X) of [2], wherein the bio-based content of the EVA (A) and / or the EVA saponified (B) with an ethylene content greater than 60 mol% is 1 to 100%.

[0020] [5] The resin composition (X) according to any one of [1] to [4], wherein the bio-based content of the EVA (A) is 1 to 100%;

[0021] [6] The resin composition (X) according to any one of [1] to [4], wherein the bio-based content of the EVA (A) is 40 to 100%;

[0022] [7] The resin composition (X) according to any one of [1] to [6], wherein the ethylene content of the EVA (A) is 60 to 98 mol%.

[0023] [8] A resin composition for recycling additives, comprising the resin composition (X) described in any one of [1] to [7].

[0024] [9] Use of any one of the resin compositions (X) described in [1] to [7] in a recycling additive.

[0025]

[10] A recycling aid comprising the resin composition (X) described in any one of [1] to [7].

[0026]

[11] The resin composition (X) according to any one of [1] to [7] further comprises a polyolefin resin (C);

[0027]

[12] The resin composition (X) according to any one of [1] to [7] further comprises EVOH(D) with an ethylene content of 60 mol% or less;

[0028]

[13] A resin composition (Y) comprising EVA (A), a polyolefin resin (C) and EVOH (D), wherein the EVA (A) comprises carbon 14.

[0029]

[14] A resin composition (Y) comprising EVA (A), EVA saponified compound (B) with an ethylene content greater than 60 mol%, a polyolefin resin (C) and EVOH (D), wherein the EVA (A) and / or the EVA saponified compound (B) comprises carbon 14.

[0030]

[15] The resin composition (Y) according to

[13] or

[14] further contains hydrotalcite (E);

[0031]

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

[13] to

[15] further comprises a higher fatty acid metal salt (F);

[0032]

[17] According to the resin composition (Y) of

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

[0033]

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

[13] to

[17] further comprises a titanium compound (G);

[0034]

[19] The resin composition (Y) according to

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

[0035]

[20] A recyclable material layer comprising the recycling aid described in

[10] .

[0036]

[21] A multi-layer structure comprising the recycled material layer described in

[20] .

[0037]

[22] The multilayer structure according to

[21] further comprises a layer containing a polyolefin resin, which does not contain EVA(A).

[0038]

[23] The multilayer structure according to

[21] or

[22] further includes an adhesive resin layer that is different from the recycled material layer and does not contain EVA(A).

[0039]

[24] A packaging body comprising any one of the multi-layer structures described in

[21] to

[23] .

[0040]

[25] A food packaging comprising any one of the multilayer structures described in

[21] to

[23] .

[0041]

[26] A method for manufacturing a recycling agent, comprising the step of mixing EVA (A) and EVA saponified (B) with an ethylene content greater than 60 mol%, wherein the EVA (A) and / or EVA saponified (B) contains carbon 14.

[0042]

[27] A method for manufacturing a recycled material layer by molding a resin composition, comprising a step of mixing a polyolefin resin (C), EVOH (D), EVA (A) and an EVA saponified compound (B) with an ethylene content greater than 60 mol%, wherein the resin composition contains carbon 14 in the EVA (A) and / or the EVA saponified compound (B).

[0043] The effects of the invention

[0044] The resin composition (X) of this invention, in the form of a resin composition containing EVA or a resin composition containing EVA and EVA saponification, exhibits excellent thermal stability and excellent color inhibition. Therefore, the resin composition (X) of this invention is suitable for use as a raw material for molded articles and multilayer structures with excellent thermal stability and color inhibition.

[0045] Furthermore, the above-mentioned resin composition (X) can be used as a recycling aid, which can improve the thermal stability of the recycled resin composition and maintain a certain quality when recycling and reusing used resin products containing polyolefin resin and EVOH, resin scraps discarded during the manufacturing process, etc.

[0046] Furthermore, although the resin composition (Y) of another aspect of the present invention is a resin composition containing polyolefin resin and EVOH, it exhibits excellent thermal stability and color inhibition properties. Therefore, the resin composition (Y) of the present invention is suitable for use as a raw material for molded articles and multilayer structures with excellent thermal stability and color inhibition properties.

[0047] Furthermore, the above-mentioned resin composition (Y), especially when it is a recycled resin composition of polyolefin resin and EVOH obtained by using recycled resin products, resin scraps discarded during the manufacturing process, etc., does not undergo thermal degradation and can maintain a certain quality, and is therefore preferred. Detailed Implementation

[0048] The present invention will now be described in more detail based on embodiments thereof, but the present invention is not limited to the following embodiments.

[0049] It should be noted that when expressed as "x~y" (x and y are arbitrary numbers) in this specification, unless otherwise specified, it includes the meaning of "above x and below y", and also includes the meaning of "preferably greater than x" or "preferably less than y".

[0050] In addition, when expressed as "X or above" (where X is any number) or "Y or below" (where Y is any number), it also implies "preferably greater than X" or "preferably less than Y".

[0051] Furthermore, "X and / or Y (X and Y are arbitrary configurations)" refers to at least one of X and Y, and specifically refers to the three cases of only X, only Y, and X and Y.

[0052] In addition, in this specification, "film" also includes the meanings of "belt" and "sheet".

[0053] Regarding the numerical ranges described in stages in this specification, the upper or lower limit of a numerical range for a certain stage can be arbitrarily combined with the upper or lower limit of numerical ranges for other stages. Furthermore, the upper or lower limit of the numerical range described in this specification can also be replaced with the values ​​shown in the embodiments.

[0054] First, the resin composition (X) (hereinafter referred to as "this resin composition (X)") which is the first aspect of the present invention is a resin composition (X) containing EVA (A) and said EVA (A) containing carbon 14, and a resin composition (X) containing EVA (A) and EVA saponified (B) with an ethylene content of more than 60 mol% and said EVA (A) and / or EVA saponified (B) containing carbon 14.

[0055] Next, for the resin composition (Y) (hereinafter referred to as "this resin composition (Y)") as a second aspect of the present invention, it is a resin composition (Y) containing EVA (A), polyolefin resin (C) and EVOH (D), wherein the EVA (A) contains carbon 14, and a resin composition (Y) containing EVA (A), EVA saponified (B), polyolefin resin (C) and EVOH (D), wherein the EVA (A) and / or EVA saponified (B) contains carbon 14.

[0056] The first and second methods will be explained in turn below.

[0057] <<The First Approach>>

[0058] The resin composition (X) is any one of the following: a resin composition (X) containing EVA (A) and wherein the EVA (A) comprises carbon 14, and a resin composition (X) containing EVA (A) and EVA saponified (B) with an ethylene content greater than 60 mol% and wherein the EVA (A) and / or EVA saponified (B) comprises carbon 14.

[0059] Furthermore, this resin composition (X) is suitable for use as a recycling aid, and therefore can be used as a resin composition for recycling aids (hereinafter referred to as "this resin composition for recycling aids").

[0060] The following is a description of each component.

[0061] <EVA(A)>

[0062] In this resin composition (X), "EVA" in EVA(A) refers to a polymer copolymerized from ethylene and vinyl acetate. Furthermore, the EVA(A) and / or the EVA saponified (B) containing more than 60 mol% ethylene in this resin composition (X) contain carbon 14, and it is particularly preferred that EVA(A) contains carbon 14.

[0063] EVA containing carbon-14 refers to EVA obtained through chemical or biological synthesis using renewable biomass resources as raw materials (hereinafter referred to as "bio-EVA"). Bio-EVA has the following characteristics: due to the carbon neutrality of biomass, it does not increase the concentration of carbon dioxide in the atmosphere even when it is incinerated.

[0064] Petroleum-derived EVA does not contain carbon-14, while it is found in biological EVA. Therefore, accelerator mass spectrometry analysis was used to determine the presence of carbon-14. 14 The concentration of C can serve as an indicator of the presence or proportion of biological EVA (bio-based content).

[0065] Among the aforementioned biomass resources, plant-based raw materials are preferred. For example, ethylene derived from plant-based materials and vinyl acetate derived from plant-based materials, specifically, are preferred. That is, the aforementioned EVA (A) containing carbon-14 is preferably EVA derived from plant-based materials.

[0066] The aforementioned bio-based content can be determined, for example, by the following method: The sample to be tested is burned to produce carbon dioxide, which is then purified in a vacuum line. Using iron as a catalyst, the purified carbon dioxide is reduced with hydrogen to produce graphite. This graphite is then mounted on a tandem accelerator-based... 14 A dedicated C-AMS device (manufactured by NEC) is used to perform... 14 Counting C 13 The concentration of C ( 13 C / 12C) 14 The concentration of C ( 14 C / 12 The determination of C) is used to calculate the carbon content of the sample. 14 The ratio of C concentration to standard modern carbon.

[0067] The bio-based content of EVA(A) used in this resin composition (X) is typically 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 bio-based content of EVA(A) within the above range, a resin composition (X) with superior thermal stability can be obtained.

[0068] It should be noted that the reason why this resin composition (X) is considered to have excellent thermal stability and color inhibition is that it contains carbon-14 ( 14 C) Bio-based EVA, compared to petroleum-derived EVA which does not contain C14, has a stronger binding energy due to the primary isotope effect, resulting in slower decomposition, improved thermal stability, and enhanced color inhibition.

[0069] The ethylene content in the above-mentioned EVA(A) is typically 1 to 99 mol%, preferably 60 to 98 mol%, and more preferably 70 to 95 mol%. That is, by setting the ethylene content to the lower limit or above, the resin composition (X) tends to have excellent thermal stability and extrusion molding properties, and by setting it to the upper limit or below, the resin composition (X) tends to have excellent color inhibition properties.

[0070] Furthermore, the vinyl acetate content in the aforementioned EVA(A) is typically 1 to 60 mol%, preferably 2 to 40 mol%, and more preferably 3 to 30 mol%. That is, by setting the vinyl acetate content to the lower limit or above, the resin composition (X) tends to have excellent color inhibition properties, and by setting it to the upper limit or below, the resin composition (X) tends to have excellent thermal stability and extrusion molding properties.

[0071] The melt flow rate (MFR) of the above-mentioned EVA(A) (190°C, 2160g load) is typically 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. By keeping the MFR within the above range, there is a tendency for the dispersibility with other resins when mixed with them to be good, and the effects of the present invention are more easily manifested.

[0072] The MFR can be determined according to JIS K7120.

[0073] It should be noted that, without hindering the spirit of the present invention, the aforementioned EVA(A) can be a modified body containing a carboxyl group obtained by chemically bonding unsaturated carboxylic acids or their anhydrides through addition reactions, grafting reactions, etc. Specifically, the amount of modification is preferably 10 mol% or less. Examples of the aforementioned unsaturated carboxylic acids or their anhydrides include olefinic unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethylacrylic acid, and crotonic acid; olefinic unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, their anhydrides, and half-esters; among which, maleic anhydride is preferred.

[0074] In addition, the above-mentioned EVA(A) can be used alone or in combination with two or more biological EVAs with different ethylene content, molecular weight, MFR, density, modifying groups, and modification amounts.

[0075] Alternatively, the aforementioned EVA(A) can also be petroleum-derived EVA. Furthermore, EVA(A) can also be a substance obtained by replacing a portion of the carbon in petroleum-derived EVA with carbon-14.

[0076] The content of EVA(A) relative to the resin composition (X) is typically 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, a resin composition (X) with particularly excellent thermal stability can be obtained.

[0077] <EVA saponification (B) with an ethylene content greater than 60 mol%>

[0078] The EVA saponified compound (B) used in this resin composition (X) with an ethylene content greater than 60 mol% is an EVA saponified compound obtained by saponifying the vinyl acetate component of EVA with an ethylene content greater than 60 mol%.

[0079] The aforementioned EVA saponified compound (B) with an ethylene content greater than 60 mol% (hereinafter referred to as "high-ethylene EVA saponified compound (B)") is polymerized by any known polymerization method, such as solution polymerization, suspension polymerization, emulsion polymerization, etc., and the saponification of its copolymer can also be carried out by known methods. Moreover, the aforementioned high-ethylene EVA saponified compound (B) can be modified as needed.

[0080] The ethylene content of the above-mentioned high-ethylene EVA saponified compound (B) is greater than 60 mol%, usually less than 98 mol%, more preferably 70-97 mol%, further preferably 75-95 mol%, and particularly preferably 80-95 mol%. By keeping the ethylene content within the above range, there is a tendency to more easily and effectively obtain the effects of the present invention (thermal stability and color inhibition).

[0081] Furthermore, the degree of saponification of the aforementioned high-ethylene EVA saponified compound (B) is typically 20 mol% or more, more preferably 40 to 99.5 mol%, and particularly preferably 80 to 99 mol%. That is, by keeping the degree of saponification within the aforementioned range, there is a tendency to more easily and effectively obtain the effects of the present invention (thermal stability, etc.).

[0082] The melt flow rate (MFR) of the above-mentioned high-ethylene EVA saponified compound (B) (190°C, 2160g load) is typically 0.5 to 100 g / 10 min, and is further preferably 1 to 50 g / 10 min, and particularly preferably 2 to 30 g / 10 min, from the perspective of excellent dispersibility and the excellent effect of the present invention.

[0083] The MFR can be determined according to JIS K7120.

[0084] The aforementioned high-ethylene EVA saponified compound (B), without hindering the spirit of the present invention, can be a modified body containing a carboxyl group obtained by chemically bonding unsaturated carboxylic acids or their anhydrides through addition reactions, grafting reactions, etc. Specifically, the amount of modification is preferably 10 mol% or less. Examples of the aforementioned unsaturated carboxylic acids or their anhydrides include olefinic unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, ethylacrylic acid, and crotonic acid; olefinic unsaturated dicarboxylic acids such as fumaric acid, itaconic acid, citraconic acid, maleic acid, monomethyl maleate, monoethyl maleate, and maleic anhydride, their anhydrides, and half-esters; among which, maleic anhydride is preferred.

[0085] The above-mentioned high-ethylene EVA saponified compound (B) can be used alone or in combination with two or more high-ethylene EVA saponified compounds with different ethylene contents, saponification degree, molecular weight, MFR, density, modifying groups, and modification amounts.

[0086] In addition, the high-ethylene EVA saponified (B) used in this resin composition (X) preferably contains carbon 14.

[0087] The bio-based content of the high-ethylene EVA saponified compound (B) used in this resin composition (X) is typically 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 bio-based content of the high-ethylene EVA saponified compound (B) within the above range, a resin composition (X) with superior thermal stability can be obtained.

[0088] The content of the aforementioned high-ethylene EVA saponified compound (B) is typically 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, by keeping the ethylene content below the upper limit, there is a tendency for the resin composition (X) to have excellent color inhibition properties, and by keeping it above the lower limit, there is a tendency for the appearance of the molded article obtained from the resin composition (X) to become good.

[0089] In addition, the total amount [(A)+(B)] obtained by adding the content of the above-mentioned EVA (A) and the content of high-ethylene EVA saponified (B) in the resin composition (X) as a whole is usually 70 to 100% by mass relative to the resin composition (X) as a whole.

[0090] It should be noted that the resin composition (X) may contain other thermoplastic resins other than components (A) and (B) such as polyamide resin, polyester resin, and polyolefin resin, within a range that does not impair the effects of the present invention (e.g., less than 30% by mass relative to the total resin composition (X)).

[0091] Furthermore, when a hydrotalcite (E) and / or a higher fatty acid metal salt (F) are used in combination with the above-mentioned EVA (A) and high-ethylene EVA saponified compound (B) in this resin composition (X), the suppression effect of foreign matter (accumulation) generated due to phase separation is improved when the molded article is obtained using this resin composition (X). Therefore, it is preferable to use hydrotalcite (E) from the viewpoint of excellent discoloration suppression effect when obtaining a recycled material layer using resin recycled material.

[0092] <Hydrotalcite (E)>

[0093] As an example of the above-mentioned hydrotalcite class (E), hydrotalcite solid solutions represented by the following general formula (1) can be cited.

[0094] [(M1 2+ ) y1 (M2 2+ ) y2 ] 1-x M x 3+ (OH)2A n- x / n ·mH2O……(1)

[0095] In the formula, M1 2+ M2 is a metal selected from Mg, Ca, Sr, and Ba. 2+ M is a metal selected from Zn, Cd, Pb, and Sn. x 3+ A is a trivalent metal. n-is an anion with a valence of n, and x, y1, y2, and m are positive numbers represented by 0 < x ≤ 0.5, 0.5 < y1 < 1, y1 + y2 = 1, and 0 ≤ m < 2.

[0096] In the above general formula (1), as M1 2+ , preferably Mg, Ca, as M2 2+ , preferably Zn, Cd. Furthermore, as M x 3+ , for example, Al, Bi, In, Sb, B, Ga, Ti, etc. can be cited. They can be used alone or in combination of two or more. Among them, Al is practical. In addition, in the above general formula (1), as A n- , for example, CO3 2- , OH - , HCO3 - , salicylic acid ion, citric acid ion, tartaric acid ion, NO3 - , I - , (OOC-COO) 2- , ClO 4- , CH3COO - , CO3 2- , (OOCHC=CHCOO) 2- , 〔Fe(CN)6〕 4- , etc. They can be used alone or in combination of two or more. Among them, CO3 2- , OH - are particularly useful.

[0097] Moreover, as specific examples of the above hydrotalcite solid solution, the following can be cited: [Mg [[ID=4D]] 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 Zn 3 / 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 / 7Pd 2 / 7 ] 0.7 Al 0.30 (OH)2(CO3) 0.15 ·0.52H2O, [Mg 0.74 Zn 0.26 ] 0.68 Al 0.32 (OH)2(CO3) 0.16 、[Mg 0.56 Zn 0.44 ] 0.68 Al 0.32 (OH)2(CO3) 0.16 ·0.2H2O, [Mg 0.81 Zn 0.19 ] 0.74 Al 0.26 (OH)2(CO3) 0.13 、[Mg 0.75 Zn 0.25 ] 0.8 Al 0.20 (OH)2(CO3) 0.10 0.16H2O, [Mg] 0.71 Zn 0.29 ] 0.7 Al 0.30 (OH)2(NO3) 0.30 、[Mg 0.71 Zn 0.29 ] 0.7 Al 0.30 (OH)₂(OOCHC=CHCOO) 0.15 、[Mg 0.14 Ca 0.57 Zn 0.28 ] 0.7 Al 0.30 (OH) 2.3 ·0.25H2O, etc., among which, in particular, [Mg] can be cited. 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 6 / 7 Cd 1 / 7 ] 0.7 Al 0.3 (OH)2(CH3COO) 0.3 ·0.34H2O, [Mg 5 / 7Pd 2 / 7 ] 0.7 Al 0.30 (OH)2(CO3) 0.15 ·0.52H2O, etc.

[0098] In addition, other examples of hydrotalcites (E) include compounds represented by the following general formula (2).

[0099] M i Al j (OH) 2i+3j-2z (E) z ·aH2O……(2)

[0100] In the formula, M is Mg, Ca or Zn, E is CO3 or HPO4, i, j, z are positive numbers, and a is 0 or a positive number.

[0101] Specifically, Mg can be cited as a compound represented by the general formula (2) above. 4.5 Al2(OH) 13 CO3·3.5H2O, Mg5Al2(OH) 14 CO3·4H2O, Mg6Al2(OH) 16 CO3·4H2O, Mg8Al2(OH) 20 CO3·5H2O, Mg 10 Al2(OH) 22 (CO3)2·4H2O, Mg6Al2(OH) 16 HPO4·4H2O, Ca6Al2(OH) 16 CO3·4H2O, Zn6Al6(OH) 16 CO3·4H2O, etc. Furthermore, not limited to the above, for example, even if a portion of the OH in Mg2Al(OH)9·3H2O is replaced with a substance whose chemical formula is not explicitly represented, such as CO3 or HPO4, or a substance whose water of crystallization has been further removed (a=0), the same effect can be expected. In particular, among these, compounds where M is Mg and E is CO3 effectively suppress discoloration caused by phase separation, reduce appearance due to phase separation foreign matter (so-called material buildup), and exhibit excellent molding stability, therefore they are preferred.

[0102] The particle size of the aforementioned hydrotalcite (E) is typically 10 µm or less on average, more preferably 5 µm or less, and particularly preferably 1 µm or less. That is, by setting the average particle size below the upper limit, it is easier to obtain the effects of the present invention more effectively. It should be noted that the average particle size referred to herein is a value measured by the LUZEX method.

[0103] Among the above-mentioned hydrotalcites (E), from the viewpoint of high forming stability, high inhibition effect of phase separation foreign matter (accumulation) and high inhibition effect of coloring, the hydrotalcite solid solution shown in the above general formula (1) is particularly preferred.

[0104] When using the aforementioned hydrotalcite (E), its content is not particularly limited, but is preferably 0.5 to 30% by mass relative to 100% by mass of EVA (A), more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass. By setting the above content to the lower limit or above, there is a tendency for improved molding stability and better suppression of foreign matter / coloring; by setting it to the upper limit or below, there is a tendency for improved appearance of the molded article, better coloring suppression effect, and superior mechanical properties.

[0105] <Higher fatty acid metal salts (F)>

[0106] Examples of the aforementioned higher fatty acid metal salts (F) include alkali metal salts such as lithium, sodium, and potassium of organic acids with 8 or more carbon atoms (more preferably 12 to 30 carbon atoms, particularly preferably 14 to 22 carbon atoms), alkaline earth metal salts such as magnesium, calcium, and barium, and transition metal salts such as zinc, copper, cobalt, iron, and manganese. From the viewpoints of suppressing phase separation foreign matter (accumulation) and coloring, and from the viewpoints of excellent molding stability, alkaline earth metal salts and transition metal salts of higher fatty acids with 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.

[0107] When using the aforementioned higher fatty acid metal salt (F), its content is not particularly limited, but is preferably 0.5 to 30% by mass relative to 100% by mass of EVA (A), more preferably 1 to 20% by mass, and even more preferably 2 to 10% by mass. By setting the above content to the lower limit or above, there is a tendency to easily obtain molding stability and foreign matter / coloring suppression effects, while by setting it to the upper limit or below, there is a tendency to obtain molded articles with good appearance, coloring suppression effects, and excellent mechanical properties.

[0108] It should be noted that when using the above-mentioned hydrotalcite (E) and higher fatty acid metal salts (F) in combination, it is also preferable that their respective contents are within the above-mentioned range.

[0109] Furthermore, in this resin composition (X), a titanium compound (G) can be used in conjunction with the aforementioned EVA (A) and high-ethylene EVA saponified compound (B). The titanium compound (G) is used as a pigment or is contained in recycled pulverized material; if such a titanium compound (G) is blended, the thermal stability of the resin composition (X) tends to decrease. In this resin composition (X), even with the inclusion of the titanium compound (G), an improved thermal stability is achieved, and the color inhibition properties of this resin composition (X) become more superior.

[0110] <Titanium Compound (G)>

[0111] Examples of the titanium compound (G) mentioned above include inorganic titanium compounds and organic titanium compounds. It should be noted that two or more titanium compounds can be used alone or in combination. Inorganic titanium compounds are preferred.

[0112] Examples of such inorganic titanium compounds include titanium oxides, titanium hydroxides, titanium chlorides, and inorganic salts of titanium.

[0113] Examples of titanium oxides mentioned above include titanium oxide (II), titanium oxide (III), titanium oxide (IV), and titanium suboxide.

[0114] Examples of titanium hydroxides mentioned above include titanium hydroxide (III) and titanium hydroxide (IV).

[0115] Examples of titanium chlorides mentioned above include titanium chloride (III) and titanium chloride (IV).

[0116] Examples of inorganic salts of titanium include titanium phosphate and titanium sulfate.

[0117] Among them, titanium oxide is preferred, titanium oxide (IV) is more preferred, and rutile titanium oxide (IV) is particularly preferred.

[0118] Examples of the aforementioned organotitanium compounds include titanium acetate, titanium butyrate, titanium stearate, and other carboxylic acid titanium compounds.

[0119] It should be noted that, in addition to existing as a titanium compound in this resin composition (X), the aforementioned titanium compound (G) may also exist in an ionized state or as a complex that interacts with resin components or other ligands.

[0120] When using the above-mentioned titanium compound (G), its average particle size is typically 0.001µm to 100µm, preferably 0.01µm to 50µm, and more preferably 0.015µm to 20µm.

[0121] When using the above-mentioned titanium compound (G), its metal conversion content relative to the resin composition (X) is preferably 1 to 20% by mass, more preferably 1 to 15% by mass, even more preferably 1 to 10% by mass, and particularly preferably 1 to 8% by mass.

[0122] It should be noted that the metal conversion content of the above titanium compound (G) can be quantified as follows: the resin composition (X) is weighed into a platinum crucible, ashed sequentially using a burner and an electric furnace, the ashed material is heated and decomposed with nitric acid and hydrofluoric acid, treated with a mixed acid of dilute nitric acid and dilute hydrofluoric acid and brought to a final volume, and the titanium in the final volume solution is determined by ICP mass spectrometry using an ICP mass spectrometry device (manufactured by Agilent Technologies, Agilent 8800), thereby quantifying the content.

[0123] <Other Ingredients>

[0124] In this resin composition (X), in addition to the aforementioned EVA (A), high-ethylene EVA saponified compound (B), suitable hydrotalcite (E), higher fatty acid metal salts (F), and titanium compounds (G), resins other than EVA (A) and high-ethylene EVA saponified compound (B) (e.g., polyolefin resins, other types of resins), and any additives (hereinafter referred to as "other components") may be blended according to various purposes, without significantly impairing the effects of the present invention. Only one other component may be used, or two or more may be used in any combination and ratio.

[0125] Examples of additives mentioned above include lubricants, plasticizers, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, crystal nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, and anti-blocking agents.

[0126] In particular, from the viewpoint of reducing the thermal degradation of the resin composition (X), antioxidants are preferably used in combination among the above-mentioned additives.

[0127] [Antioxidants]

[0128] As examples of the antioxidants mentioned above, at least one of the following antioxidants can be selected.

[0129] Hindered phenolic compounds: butylated hydroxytoluene, 2,5-di-tert-butylhydroquinone, 2,6-di-tert-butyl-p-cresol, 4,4'-thiobis-(6-tert-butylphenol), 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propionate]methane, N,N'-hexamethylene-bis(3,5-di-tert-butyl-4'-hydroxy-hydrogenated cinnamamide), 1,3,5-trimethyl-2,4,6tris(3,5-di-tert-butyl-4-hydroxybenzyl) Pentaerythritol tetra-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylaniline)-1,3,5-triazine, 2,2-thio-diethylidene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate diethyl ester, bis(3,5-di-tert-butyl-4-hydroxybenzylphosphonate ethyl ester) calcium, tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 2,4-bis[(octylthio)methyl]-o-cresol, isooctyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-tert-butyl-6-(3-tert-butyl-6-hydroxyphenyl)propionate Butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 4,4'-butylenebis(3-methyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 3,9-bis{2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)-propionyloxy]-1,1-dimethylethyl}-2,4,8,10-tetraoxaspiro(55)undecane, etc.;

[0130] Phosphite compounds: triphenyl phosphite, tri(p-nonylphenyl) phosphite, tri(2,4-di-tert-butylphenyl) phosphite, and other triaryl phosphite esters; diphenyl isooctyl phosphite, diphenyl isodecanyl phosphite, and other monoalkyl diphenyl phosphite esters; dialkyl monophenyl phosphite esters such as phenyl diisooctyl phosphite, phenyl diisodecyl phosphite, and other alkyl aryl phosphite esters; triisooctyl phosphite, tristearyl phosphite, and other trialkyl phosphite esters; bis(2,4-di-tert-butylphenyl)pentaerythritol-diphosphite, etc.

[0131] Thioether compounds: pentaerythritol-tetra-(β-lauryl thiopropionate), tetra[methylene-3-(dodecyl thio)propionate]methane, bis[2-methyl-4-{3-n-alkylthiopropionoxy}-5-tert-butylphenyl] sulfide, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearate-3,3'-thiodipropionate, pentaerythritol-tetra(3-lauryl thiopropionate), di(tetranyl)-3,3'-thiodipropionate, 2-mercaptobenzimidazole, etc.

[0132] Hindered amine compounds: dimethyl succinate·1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine condensate, poly{[6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidinyl)imino]}, N,N'-bis(3-aminopropyl)ethylenediamine· 2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidinyl)amino]-6-chloro-1,3,5-triazine condensate, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid bis(1,2,2,6,6-pentamethyl-4-piperidinyl) ester, etc.;

[0133] Benzotriazole compounds: 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-tert-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3 ,5-Di-tert-pentyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, methyl-3-[3-tert-butyl-5-(2H-benzotriazole-2-yl)-4-hydroxyphenyl]propionate-polyethylene glycol condensate, hydroxyphenylbenzotriazole derivatives, 2-[2-hydroxy-3-(3,4,5,6-tetra-hydrophthalimino-methyl)-5-methylphenyl]benzotriazole, etc.;

[0134] Benzophenone compounds: 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, etc.

[0135] As for the properties of these antioxidants, antioxidants can be used in any form, such as powder, granules, liquid, paste, emulsion, etc.

[0136] Among the antioxidants mentioned above, hindered phenolic antioxidants are preferred, especially pentaerythritol tetra-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, which have excellent effects on reducing the thermal degradation of this resin composition (X) and thus do not hinder the effects of the present invention (suppressing discoloration of the recycled material layer).

[0137] When using the antioxidant described above, its content is typically 0.001 to 10% by mass relative to 100% by mass of EVA(A), preferably 0.01 to 5% by mass, and particularly preferably 0.05 to 1% by mass. By setting the content of the antioxidant to the lower limit or above, there is a tendency to reduce the thermal degradation of the resin composition (X), and by setting it to the upper limit or below, there is a tendency to improve the appearance, anti-discoloration effect, and mechanical properties of the resulting molded article.

[0138] It should be noted that when the resin composition (X) contains the above-mentioned "other components", their total content is generally 30% by mass or less relative to the resin composition (X), preferably 20% by mass or less, and more preferably 10% by mass or less.

[0139] [Method for manufacturing resin composition (X)]

[0140] This resin composition (X) can be manufactured by mixing EVA (A) and high-ethylene EVA saponified compound (B), as essential components, hydrotalcite (E), higher fatty acid metal salts (F), titanium compounds (G), and other components as appropriate. Examples of mixing methods include known methods such as dry mixing, melt mixing using a single-screw extruder or a twin-screw extruder to obtain the composite, solution mixing, and impregnation, and combinations thereof are also possible.

[0141] [Resin Composition (X)]

[0142] The resin composition (X) obtained in this way, compared with conventional resin compositions of EVA (A) and / or EVA saponification (B) that do not contain carbon 14, is less prone to decomposition under high temperature heating, has excellent thermal stability, and has excellent color inhibition properties.

[0143] The melt flow rate (MFR) of this resin composition (X) (190°C, 2160g load) is typically 0.1 to 50 g / 10 min, preferably 0.5 to 30 g / 10 min, and particularly preferably 2 to 10 g / 10 min.

[0144] The MFR can be determined according to JIS K7120.

[0145] The moisture content of this resin composition (X) is generally 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.

[0146] It should be noted that the moisture content of this resin composition (X) was determined and calculated using the following method.

[0147] Weigh the resin composition before drying (W1) using an electronic balance. Dry it in a hot air dryer at 150°C for 5 hours. Weigh the composition after cooling in the dryer for 30 minutes (W2) and calculate it using the following formula.

[0148] Moisture content (mass%) = [(W1-W2) / W1] × 100

[0149] This resin composition (X) is prepared in various forms such as granules and powders, and is provided as a material for various molded articles and multilayer structures. Moreover, as described above, this resin composition (X) has excellent thermal stability and color retention, therefore, molded articles using this resin composition (X), or multilayer structures having layers using this resin composition (X), have the advantage of minimal quality degradation such as thermal deterioration and color retention, even when recycled.

[0150] Furthermore, this resin composition (X) is suitable as a recycling aid (hereinafter referred to as "this recycling aid") for resin recyclables containing polyolefin resin (C) and EVOH (D) as described later (e.g., recyclables obtained by recycling waste containing a laminate containing a polyolefin resin (C) layer and an EVOH (D) layer).

[0151] [Resin Composition for Recycling Additives]

[0152] When the resin composition (X) is used as a resin composition for recycling aids, the content of the resin composition (X) relative to the total content of the resin composition for recycling aids 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.

[0153] The higher the content, the easier it is to achieve the effect of a recycling aid.

[0154] It should be noted that, in this specification, recycling aids refer to additives mixed when resin recyclables containing polyolefin resin (C) and EVOH (D) (e.g., recyclables obtained by recycling waste materials containing polyolefin resin layers and EVOH layers), and are sometimes also called compatibilizers or recycling aids.

[0155] In addition, this recycling aid is made by forming it into a powder using a resin composition.

[0156] [molded body]

[0157] An example of the molded body of the present invention (hereinafter referred to as "the molded body I") is formed by molding the resin composition (X).

[0158] Examples of shapes for this molded body I include films, sheets, belts, cups, trays, tubes, bottles, pipes, filaments, extrusions with irregular cross-sections, and various irregularly shaped bodies.

[0159] Furthermore, there are no particular limitations on the molding method used to obtain this molded article I; any molding method applicable to general resin compositions may be used. Examples of molding methods include extrusion molding, blow molding, injection molding, and thermoforming.

[0160] [Multi-layer structure]

[0161] An example of an embodiment of the present invention is a multilayer structure (hereinafter referred to as "this multilayer structure I") having a layer comprising the above-described resin composition (X).

[0162] This multilayer structure I can be further enhanced with strength or other functions by being laminated with other substrates that are mainly composed of thermoplastic resins other than this resin composition (X).

[0163] It should be noted that the main component of thermoplastic resin refers to the component that has a significant impact on the determination of the substrate. 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 it can also be 100% by mass.

[0164] <<Second Method>>

[0165] The resin composition (Y) is a resin composition (Y) containing EVA (A), polyolefin resin (C) and EVOH (D), wherein the EVA (A) comprises carbon 14, and a resin composition (Y) containing EVA (A), EVA saponified compound (B) with an ethylene content greater than 60 mol%, polyolefin resin (C) and EVOH (D), wherein the EVA (A) and / or the aforementioned EVA saponified compound (B) comprises carbon 14.

[0166] <EVA(A)>

[0167] EVA (A) used in this resin composition (Y) can be the same substance as that described in the first embodiment above.

[0168] The content of EVA(A) used in this resin composition (Y) is typically 0.02 to 35% by mass relative to the resin composition (Y), preferably 0.5 to 30% by mass, more preferably 0.8 to 15% by mass, and even more preferably 1.0 to 10% by mass. By setting the content of EVA(A) within the above range, a resin composition (Y) with particularly excellent thermal stability can be produced.

[0169] <EVA saponification (B) with an ethylene content greater than 60 mol%>

[0170] As an EVA saponified compound (B) with an ethylene content greater than 60 mol% used in this resin composition (Y), the same substance as that described in the first embodiment above can be cited.

[0171] The content of EVA saponified material (B) with an ethylene content greater than 60 mol% used in this resin composition (Y) is typically 0.001 to 30% by mass relative to this resin composition (Y), 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. By keeping the ethylene content below the upper limit, there is a tendency for the resin composition (Y) to have excellent color inhibition properties, and by keeping it above the lower limit, there is a tendency for the appearance of the molded article obtained from the resin composition (Y) to become better.

[0172] <Polyolefin Resin (C)>

[0173] Examples of polyolefin resins (C) (excluding EVA (A) and EVA saponification (B)) used in this resin composition (Y) include, for example, linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), ultra-low-density polyethylene (VLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), etc., polypropylene (PP), ionomers, ethylene-propylene (block or random) copolymers, ethylene-acrylic acid copolymers, ethylene-acrylate copolymers, ethylene-methacrylic acid copolymers, ethylene-methacrylate copolymers, propylene-α-olefin (α-olefin with 4 to 20 carbon atoms) copolymers, ethylene-α-olefin (α-olefin with 4 to 20 carbon atoms) copolymers, homopolymers or copolymers of olefins such as polybutene, polypentene, and polymethylpentene, or blends thereof. They can be used alone or in combination of two or more. From the perspective of economy and mechanical properties, polyethylene, ethylene-propylene (block or random) copolymers, polypropylene (PP) and their blends are preferred. Furthermore, from the perspective of particularly excellent effects of the present invention, polyethylene, polypropylene (PP) and ethylene-propylene (block or random) copolymers are particularly preferred.

[0174] The melt flow rate (MFR) of the above-mentioned polyolefin resin (C) (230°C, 2160g load) is typically 0.1 to 50g / 10 minutes, and more preferably about 0.5 to 30g / 10 minutes.

[0175] The MFR can be determined according to JIS K7120.

[0176] In the above-mentioned polyolefin resin (C), known plasticizers, lubricants, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, crystal nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, antiblocking agents, and other additives may be blended within a range that does not impair the effects of the present invention (e.g., less than 30% by mass relative to the total polyolefin resin (C), or other polyolefin resins may be blended.

[0177] The content of the polyolefin resin (C) in the resin composition (Y) is typically 40 to 99.99% by mass relative to the total resin composition (Y), preferably 45 to 99.9% by mass, more preferably 50 to 99% by mass, and even more preferably 65 to 95% by mass. When the polyolefin resin (C) is within the above range, the excellent effects of the present invention can be more fully obtained.

[0178] <EVOH(D)>

[0179] The EVOH(D) used in this resin composition (Y) is typically a resin obtained by saponifying an ethylene-vinyl ester copolymer, which is a copolymer of ethylene and a vinyl ester monomer. It is a non-water-soluble thermoplastic resin, and the ethylene content is usually less than 60 mol%. From an economic perspective, vinyl acetate is typically used as the aforementioned vinyl ester monomer.

[0180] The polymerization of ethylene and vinyl ester monomers can be carried out using any known polymerization method, such as solution polymerization, suspension polymerization, or emulsion polymerization, with solution polymerization using methanol as a solvent being common. The saponification of the resulting ethylene-vinyl ester copolymer can also be performed using known methods.

[0181] The EVOH(D) produced in this way is mainly composed of structural units derived from ethylene and vinyl alcohol, and usually contains a certain amount of unsaponified vinyl ester structural units.

[0182] Vinyl acetate is a representative vinyl ester monomer used in this context due to its market availability and efficient impurity removal during manufacturing. Other vinyl ester monomers include, for example, aliphatic vinyl esters such as vinyl formate, vinyl propionate, vinyl valerate, vinyl butyrate, vinyl isobutyrate, vinyl neovalerate, vinyl decanoate, vinyl laurate, vinyl stearate, and vinyl tert-carbonate, as well as aromatic vinyl esters such as vinyl benzoate. Generally, aliphatic vinyl esters with 3 to 20 carbon atoms, preferably 4 to 10, and particularly preferably 4 to 7 carbon atoms, are used. These monomers can be used alone or in combination of two or more.

[0183] The ethylene content in the above-mentioned EVOH(D) can be controlled by the ethylene pressure during copolymerization of the vinyl ester monomer and ethylene, and is typically below 60 mol%. Preferably, it is 20 to 60 mol%, more preferably 25 to 50 mol%, and particularly preferably 25 to 35 mol%. By keeping the ethylene content above the lower limit, there is a tendency for excellent gas barrier properties and melt formability under high humidity, and by keeping it below the upper limit, there is a tendency for excellent gas barrier properties.

[0184] It should be noted that the ethylene content can be determined based on ISO 14663.

[0185] Furthermore, the degree of saponification of the vinyl ester component in EVOH(D) can be controlled by the amount, temperature, and time of the saponification catalyst (usually an alkaline catalyst such as sodium hydroxide) during the saponification of the ethylene-vinyl ester copolymer. It is typically 90-100 mol%, preferably 95-100 mol%, and particularly preferably 99-100 mol%. By keeping the degree of saponification within the above range, there is a tendency for excellent gas barrier properties, thermal stability, and moisture resistance.

[0186] The degree of saponification of EVOH can be determined based on JIS K6726 (wherein EVOH is used in the form of a solution uniformly dissolved in water / methanol solvent).

[0187] Furthermore, the melt flow rate (MFR) of the aforementioned EVOH(D) (190°C, 2160g load) 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. By setting the MFR below the upper limit, there is a tendency for stable film-forming properties; by setting the MFR above the lower limit, there is a tendency for stable viscosity and good melt extrusion.

[0188] The MFR is an indicator of the degree of polymerization of EVOH, and it can be adjusted by the amount of polymerization initiator and solvent used in the copolymerization of ethylene and vinyl ester monomers. Furthermore, the MFR can be determined according to JIS K7120.

[0189] In addition, EVOH(D) may further contain structural units from the comonomers shown below, within a range that does not impair the effects of the present invention (e.g., less than 10 mol% relative to the EVOH as a whole).

[0190] Examples of the aforementioned comonomers include olefins such as propylene, 1-butene, and isobutene; hydroxyl-containing α-olefins such as 3-buten-1-ol, 3-buten-1,2-diol, 4-penten-1-ol, and 5-hexen-1,2-diol, as well as their esterified and acylated derivatives; hydroxyalkyl vinylides such as 2-methylenepropane-1,3-diol and 3-methylenepentane-1,5-diol; and 1,3-diacetoxy-2-methylenepropane and 1,3-dipropionyloxy-2-methylenepropane. Hydroxyalkyl vinylidene diacetate esters such as methylpropane and 1,3-dibutyryloxy-2-methylenepropane; unsaturated acids such as acrylic acid, methacrylic acid, crotonic acid, phthalic acid (anhydride), maleic acid (anhydride), itaconic acid (anhydride), or their salts, or monoalkyl or dialkyl esters with alkyl groups having 1 to 18 carbon atoms; acrylamide, N-alkylacrylamide, N,N-dimethylacrylamide, 2-acrylamide propanesulfonic acid or their salts, and acrylamide propyl dimethyl... Acrylamides such as amines or their acid salts or quaternary ammonium salts; methacrylamides, N-alkylmethacrylamides with alkyl groups having 1-18 carbon atoms, N,N-dimethylmethacrylamide, 2-methacrylamide propanesulfonic acid or its salts, methacrylamide propyl dimethylamine or its acid salts or quaternary ammonium salts, etc.; N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, etc.; cyanocyanates such as acrylonitrile and methacrylonitrile; alkyl groups with 1-18 carbon atoms... Alkyl vinyl ethers of 1–18; vinyl ethers such as hydroxyalkyl vinyl ethers and alkoxyalkyl vinyl ethers; halogenated vinyl compounds such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, and vinyl bromide; vinyl silanes such as trimethoxyvinylsilane; allyl halides such as allyl acetate and allyl chloride; allyl alcohols such as allyl alcohol and dimethoxyallyl alcohol; comonomers such as trimethyl-(3-acrylamido-3-dimethylpropyl)-ammonium chloride and acrylamide-2-methylpropanesulfonic acid. These can be used alone or in combination of two or more.

[0191] In particular, EVOH with primary hydroxyl groups in the side chains is preferred from the perspective of improving secondary forming properties while maintaining gas barrier properties. Among them, EVOH copolymerized with hydroxyl-containing α-olefins is preferred, and EVOH with 1,2-diol structures in the side chains is particularly preferred. Especially in the case of EVOH with primary hydroxyl groups in the side chains, the content of structural units from the monomers with primary hydroxyl groups is typically 0.1 to 20 mol% of the EVOH, more preferably 0.5 to 15 mol%, and particularly preferably 1 to 10 mol%.

[0192] In addition, the above-mentioned EVOH(D) can be a substance that has undergone "post-modification" such as urethane esterification, acetalization, cyanoethylation, or oxidative olefination.

[0193] Furthermore, the aforementioned EVOH(D) can be a mixture of two or more types of EVOH, such as EVOH with different degrees of saponification, EVOH with different degrees of polymerization, or EVOH with different copolymer components.

[0194] The content of EVOH(D) in the resin composition (Y) relative to the total resin composition (Y) is typically 0.1 to 30% by mass, preferably 0.3 to 25% by mass, more preferably 0.4 to 23% by mass, even more preferably 0.5 to 15% by mass, and particularly preferably 1.0 to 10% by mass. When the EVOH(D) is within the above range, the excellent effects of the present invention can be fully realized.

[0195] It should be noted that, in this resin composition (Y), in addition to the above-mentioned components, when the above-mentioned hydrotalcite (E) and / or higher fatty acid metal salt (F) are used in combination, the suppression effect of foreign matter (accumulation) generated due to phase separation is improved when the molded article is obtained using this resin composition (Y). Therefore, it is preferable to use hydrotalcite (E) from the perspective that the discoloration suppression effect is particularly excellent when the recycled material layer is obtained using the resin recycled material.

[0196] <Hydrotalcite (E)>

[0197] As the hydrotalcite (E) used in this resin composition (Y), the same substance as the hydrotalcite (E) described in the first embodiment above can be cited.

[0198] When the resin composition (Y) contains the aforementioned hydrotalcite (E), its content is not particularly limited, but is typically 0.001 to 30% by mass relative to the resin composition (Y), 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. By setting the above content to the lower limit or above, there is a tendency for improved molding stability and better suppression of foreign matter / coloring; by setting it to the upper limit or below, there is a tendency for improved appearance of the molded article, better coloring suppression effect, and superior mechanical properties.

[0199] <Higher fatty acid metal salts (F)>

[0200] As the higher fatty acid metal salt (F) used in this resin composition (Y), examples can be the same higher fatty acid metal salts (F) described in the first embodiment above.

[0201] When the resin composition (Y) contains the aforementioned higher fatty acid metal salt (F), its content is not particularly limited, but is typically 0.001 to 30% by mass relative to the resin composition (Y), 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. By setting the above content to the lower limit or above, there is a tendency to easily obtain molding stability and foreign matter / coloring suppression effects, while by setting it to the upper limit or below, there is a tendency to obtain molded articles with good appearance, coloring suppression effects, and excellent mechanical properties.

[0202] It should be noted that when using the above-mentioned hydrotalcite (E) and higher fatty acid metal salts (F) in combination, it is also preferable that their respective contents are within the above-mentioned range.

[0203] Furthermore, in this resin composition (Y), a titanium compound (G) can be used in conjunction with the above-mentioned EVA (A), high-ethylene EVA saponified compound (B), polyolefin resin (C) and EVOH (D).

[0204] <Titanium Compound (G)>

[0205] As the titanium compound (G) used in this resin composition (Y), the same substance as the titanium compound (G) described in the first embodiment above can be cited.

[0206] When using the above-mentioned titanium compound (G), its metal conversion content relative to the resin composition (Y) as a whole is preferably 0.0001 to 20% by mass, more preferably 0.001 to 15% by mass, even more preferably 0.005 to 10% by mass, and particularly preferably 0.01 to 8% by mass.

[0207] <Other Ingredients>

[0208] In addition to the components described above, this resin composition (Y) may contain different types of resins, any additives, etc. (hereinafter referred to as "other components"), depending on various purposes, without significantly impairing the effects of the present invention. Only one of the other components may be used, or two or more may be used in any combination and ratio.

[0209] Examples of additives mentioned above include lubricants, plasticizers, heat stabilizers, light stabilizers, ultraviolet absorbers, antioxidants, crystal nucleating agents, colorants, antistatic agents, surfactants, antibacterial agents, desiccants, oxygen absorbers, and anti-blocking agents.

[0210] In particular, from the viewpoint of obtaining a reduction effect on the thermal degradation of the resin composition (Y), antioxidants are preferably used in combination among the above-mentioned additives.

[0211] Antioxidants

[0212] As the antioxidant used in this resin composition (Y), the same antioxidant as that described in the first embodiment can be cited.

[0213] When the above-mentioned antioxidant is used in the resin composition (Y), its content, for example, relative to the resin composition (Y), is typically 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. By setting the content of the antioxidant to the lower limit or above, there is a tendency to easily reduce the thermal degradation of the resin composition (Y), and by setting it to the upper limit or below, there is a tendency for the obtained molded article to have a better appearance and excellent anti-discoloration effect / mechanical properties.

[0214] It should be noted that when the resin composition (Y) contains the above-mentioned "other components", their total content relative to the resin composition (Y) is generally 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less.

[0215] [Method for manufacturing resin composition (Y)]

[0216] This resin composition (Y) can be manufactured by mixing EVA (A), high-ethylene EVA saponification (B), polyolefin resin (C), EVOH (D), hydrotalcite (E), higher fatty acid metal salt (F), titanium compound (G), and other components as the above-mentioned essential components.

[0217] Furthermore, this resin composition (Y) can be manufactured by mixing the above-mentioned resin composition (X) with polyolefin resin (C) and EVOH (D). It should be noted that when the above-mentioned resin composition (X) contains hydrotalcite (E), higher fatty acid metal salts (F), and titanium compounds (G), even without adding hydrotalcite (E), higher fatty acid metal salts (F), or titanium compounds (G), it is possible to manufacture a resin composition (Y) with excellent thermal stability and color inhibition properties.

[0218] Examples of the aforementioned mixing methods include known methods such as dry mixing, melt mixing using a single-screw extruder or a twin-screw extruder to obtain the composite, solution mixing, and impregnation, and these methods can be combined in any way.

[0219] It should be noted that the above-mentioned polyolefin resin (C) and EVOH (D) can be used as recycled resins obtained by crushing waste materials such as waste materials containing laminates of polyolefin resin layers and EVOH layers.

[0220] [Resin Composition (Y)]

[0221] The resin composition (Y) obtained in this way, compared with conventional resin compositions of EVA (A) and / or high-ethylene EVA saponification (B) without carbon 14, is less prone to decomposition under high temperature heating, has excellent thermal stability, and has excellent color inhibition properties.

[0222] The melt flow rate (MFR) of this resin composition (Y) (230°C, 2160g load) is typically 0.1 to 50 g / 10 min, preferably 0.5 to 30 g / 10 min, and particularly preferably 2 to 10 g / 10 min.

[0223] The MFR can be determined according to JIS K7120.

[0224] The moisture content of this resin composition (Y) is generally 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.

[0225] It should be noted that the moisture content of this resin composition (Y) was determined and calculated using the following method.

[0226] Weigh the resin composition before drying (W1) using an electronic balance. Dry it in a hot air dryer at 150°C for 5 hours. Weigh the composition after cooling in the dryer for 30 minutes (W2) and calculate it using the following formula.

[0227] Moisture content (mass%) = [(W1-W2) / W1] × 100

[0228] This resin composition (Y) is prepared in various forms such as granules and powders, and is provided as a material for various molded articles and multilayer structures. Moreover, as mentioned above, this resin composition (Y) has excellent thermal stability and color retention. Therefore, molded articles using this resin composition (Y), or multilayer structures having layers using this resin composition (Y), have the advantage of minimal quality degradation such as thermal deterioration and color retention, even when recycled.

[0229] Furthermore, as mentioned above, the polyolefin resin (C) and EVOH (D) can be substances derived from recycled materials obtained by recycling waste materials containing a laminate including a polyolefin resin (C) layer and EVOH (D), etc. When the resin composition (Y) is such a recycled resin composition, as mentioned above, the quality degradation such as thermal deterioration and coloring is small. Therefore, it is preferable to provide molded articles and multilayer structures with excellent quality.

[0230] [molded body]

[0231] An example of the molded body of the present invention (hereinafter referred to as "this molded body II") is formed by molding the resin composition (Y).

[0232] Examples of shapes for this molded body II include films, sheets, belts, cups, trays, tubes, bottles, pipes, filaments, extrusions with irregular cross-sections, and various irregularly shaped bodies.

[0233] Furthermore, there are no particular limitations on the molding method used to obtain this molded article II; any molding method applicable to general resin compositions may be used. Examples of molding methods include extrusion molding, blow molding, injection molding, and thermoforming.

[0234] [Multi-layer structure]

[0235] An example of an embodiment of the present invention is a multilayer structure (hereinafter referred to as "this multilayer structure II") having at least one layer comprising the above-described resin composition (Y).

[0236] This multilayer structure II can be further enhanced with strength or other functions by being laminated with other substrates whose main component is a thermoplastic resin of this resin composition (Y).

[0237] It should be noted that the main component of thermoplastic resin refers to the component that has a significant impact on the determination of the substrate. 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 it can also be 100% by mass.

[0238] Furthermore, in this multilayer structure II, the layer containing the resin composition (Y) is preferably a layer (recycled material layer) formed using the resin composition (Y) (= recycled resin composition), wherein the resin composition (Y) comprises a polyolefin resin (C) layer and EVOH (D) derived from recycled materials obtained by recycling waste materials containing a laminate comprising a polyolefin resin (C) layer and an EVOH (D) layer. The following describes such a multilayer structure having a recycled material layer.

[0239] [Recycled Material Layer]

[0240] The recycled material used to obtain an example of an embodiment of the present invention, comprising a polyolefin resin (C) layer and an EVOH (D) layer, refers to a substance obtained during its manufacturing process from the recycling of unwanted parts such as scraps and ends of the product, defective products, or waste after the molded body has been used for various purposes. This recycled material is then used to prepare the resin composition (Y), and the recycled material layer can be obtained using it.

[0241] It should be noted that the recyclables used for reuse are usually waste materials related to one molded body, but waste materials related to two or more molded bodies can also be used as recyclables.

[0242] To obtain the aforementioned recycled material layer, for example, EVA (A), high-ethylene EVA saponification (B), and other arbitrary components that are other components of this resin composition (Y) can be appropriately combined into the aforementioned recycled material (a composition containing polyolefin resin (C) and EVOH (D)). Alternatively, the aforementioned resin composition (X) can be added to the aforementioned recycled material (a composition containing polyolefin resin (C) and EVOH (D)). By uniformly mixing them, this resin composition (Y) is obtained as a recycled resin composition. Then, by melt molding using this resin composition (Y), this multilayer structure having a recycled material layer can be obtained.

[0243] First, in order to supply the recycled material of the above-mentioned laminated body for melt molding again using an extruder or the like, it is preferable to crush the recycled material.

[0244] The aforementioned recycled material can be pulverized using a known pulverizer. Regarding the shape and particle size of the pulverized material, for example, based on the value determined by the "5.3 Apparent Density" test method according to JIS-K6891, it is typically 0.25 to 0.85 g / mL, more preferably 0.3 to 0.7 g / mL, and particularly preferably 0.35 to 0.6 g / mL. When the apparent density is above the lower limit, there is a tendency for good dispersion of EVOH in the recycled material layer, and for excellent melt formability and mechanical properties of the resulting molded article's recycled material layer. When the density is below the upper limit, there is a tendency to suppress the occurrence of poor supply in the extruder, and for excellent melt formability of the resulting molded article's recycled material layer.

[0245] The apparent density can be controlled by arbitrarily adjusting the shape of the pulverizer blades, the rotation speed of the pulverizer blades, the pulverization processing speed, and the size of the mesh openings used.

[0246] Here, the EVOH content in the above-mentioned recycled material is typically 0.1 to 30% by weight relative to the total weight of the recycled material. In order to particularly exert the effect of this resin composition (Y), it is further preferably set to 0.3 to 25% by weight, and particularly preferably set to 0.5 to 20% by weight. This is because, in the present invention, any amount of recycled material can exert an improving effect, but within the above range, it can exert a particularly improving effect.

[0247] The EVOH content in the aforementioned recycled material depends on the thickness ratio of the EVOH layers in the laminate. If the EVOH content is too low, it can be adjusted by mixing appropriate amounts of unused identical or different EVOH as needed. Conversely, if the EVOH content is too high, it is practically preferable to mix appropriate amounts of unused identical or different polyolefin resins to adjust the content.

[0248] Next, EVA (A), high-ethylene EVA saponified material (B), etc., which are the remaining components of this resin composition (Y), are blended into the pulverized recycled material. Alternatively, the above-mentioned resin composition (X) is blended.

[0249] As for the above-mentioned mixing method, known mixing devices such as swing mixers, ribbon mixers, super mixers, and pipe mixers can be used.

[0250] In this way, the present resin composition (Y) can be obtained as a recycled resin composition containing recycled materials.

[0251] Using this resin composition (Y), a multilayer structure having at least one recycled material layer can be obtained. This multilayer structure having a recycled material layer is generally preferably a multilayer structure comprising, in addition to the recycled material layer, a polyolefin resin layer and an EVOH layer, and an adhesive resin layer as needed. It should be noted that the polyolefin resin layer, the EVOH layer, and the adhesive resin layer do not contain EVA (A).

[0252] Examples of layer compositions that include a multilayer structure containing a recycled material layer include: a polyolefin resin layer / recycled material layer / adhesive resin layer / EVOH layer, a polyolefin resin layer / recycled material layer / adhesive resin layer / EVOH layer / adhesive resin layer / polyolefin resin layer, a polyolefin resin layer / recycled material layer / adhesive resin layer / EVOH layer / adhesive resin layer / recycled material layer / polyolefin resin layer, and a recycled material layer / EVOH layer, a recycled material layer / adhesive resin layer / EVOH layer, a recycled material layer / adhesive resin layer / EVOH layer / adhesive resin layer / EVOH layer, a recycled material layer / adhesive resin layer / EVOH layer / adhesive resin layer / polyolefin resin layer, a recycled material layer / adhesive resin layer / EVOH layer / adhesive resin layer / polyolefin resin layer, a polyolefin resin layer / adhesive resin layer / EVOH layer / recycled material layer / EVOH layer / adhesive resin layer / polyolefin resin layer, etc.

[0253] The thickness of each layer in a multilayer structure containing a recycled material layer varies depending on the layer composition, the type of polyolefin resin, the application, the container shape, and the required physical properties, and cannot be generalized. The recycled material layer is typically 5-5000 µm, more preferably 30-1000 µm. The EVOH layer is typically 5-500 µm, more preferably 10-200 µm. The polyolefin resin layer is typically 5-5000 µm, more preferably 30-1000 µm. In the case of an adhesive resin layer, this adhesive resin layer is typically 5-400 µm, more preferably 10-150 µm.

[0254] Furthermore, the thickness ratio of the recycled material layer to the polyolefin resin layer is typically 1 / 5 to 10 / 1, and more preferably 1 / 2 to 5 / 1. Moreover, the thickness ratio of the recycled material layer to the EVOH layer is typically 1 / 1 to 100 / 1, and more preferably 5 / 1 to 20 / 1.

[0255] The aforementioned multilayer structure containing the recycled material layer can be formed, for example, by the same method as the method for forming the aforementioned laminate of recycled material. Specifically, it can be manufactured using the polyolefin resin used in the polyolefin resin layer of the laminate of recycled material, the EVOH used in the EVOH layer, and the adhesive resin used in the adhesive resin layer, by the method illustrated below.

[0256] Examples of methods for obtaining the aforementioned multilayer structure include: a method of melt-extruding and laminating the resin composition (Y) onto a film or sheet of EVOH; a method of melt-extruding and laminating the resin composition (Y) onto a substrate composed of a polyolefin layer; a method of co-extruding EVOH or polyolefin resin with the resin composition (Y); and a method of dry laminating a film or sheet of EVOH or polyolefin resin with a film or sheet of the resin composition (Y) using an adhesive such as an organotitanium compound, isocyanate compound, polyester compound, or polyurethane compound. The melt forming temperature during the melt extrusion process is typically in the range of 150°C to 300°C.

[0257] The aforementioned multilayer structure containing recycled material layers can be directly used in products of various shapes. However, in order to further improve the physical properties of the laminate and form any container shape, a heat stretching process can also be implemented.

[0258] The heat stretching process here refers to the operation of shaping a multi-layered structure in the form of a film, sheet, or preform into a cup, tray, tube, or bottle by means of chuck, plug, vacuum force, compressed air force, blow molding, etc., after the film or sheet has been heated evenly.

[0259] Examples of stretching methods used in the aforementioned heat stretching treatment include roll stretching, tenter frame stretching, tubular stretching, stretch blow molding, vacuum forming, pneumatic forming, and vacuum pneumatic forming. In the case of biaxial stretching, either simultaneous biaxial stretching or successive biaxial stretching can be used. The stretching temperature is typically 60~170℃, more preferably around 80~160℃. Either uniaxial or biaxial stretching can be used. When stretching at the highest possible ratio, good physical properties are achieved, and stretch-formed bodies with excellent gas barrier properties are obtained without pinholes, cracks, uneven stretching, uneven thickness, delamination, etc.

[0260] It should be noted that in this multilayer structure, the recycled material used for the recycling material layer can also have a recycling material layer within the recycled material itself. The laminate having at least one such recycling material layer can be formed using the same resin as the recycled material as the raw material and by the same method. That is, a laminate (recycled product) having at least one recycling material layer can be manufactured using a resin composition obtained from the recycled material, and the recycled material of this molded body can be reused for the recycling material layer of the same laminate (repeatedly recycled product).

[0261] In addition, as another way of this multilayer structure, [1] the recycled material of a laminate with different polyolefin resin layers, different EVOH layers and / or different multilayers can be used in the same recycled material layer, [2] the recycled material can be used in a recycled material layer having a laminate of polyolefin resin and EVOH of a different kind than the polyolefin resin and EVOH contained in the recycled material.

[0262] In addition, in order to improve the formability, physical properties, etc., antioxidants, heat stabilizers, light stabilizers, lubricants, antistatic agents, crystal nucleating agents, plasticizers, colorants, ultraviolet absorbers, surfactants, antibacterial agents, desiccants, oxygen absorbers, anti-blocking agents, slip agents, inorganic / organic fillers, etc., may be added to each layer of this multilayer structure without impairing the effects of the present invention.

[0263] In addition, this multi-layer structure can be heat-treated, cooled, rolled, printed, dry-laminated, solution or melt-coated, bag-making, deep-drawing, box-making, tube-making, and segmentation as needed.

[0264] This multi-layered structure can be used as a recycled or repeatedly recycled product. It is useful as a container for various foods, such as mayonnaise, sauces, fermented foods like miso, oils, soups, beverages, cosmetics, pharmaceuticals, detergents, fragrances, industrial pharmaceuticals, pesticides, and fuels. It is particularly useful for semi-solid foods / seasonings such as mayonnaise, ketchup, sauces, miso, wasabi, yellow mustard, and barbecue sauces; bottle-shaped and tubular containers for liquid beverages / seasonings such as salad oil, cooking wine, sake, beer, wine, fruit juice, black tea, sports drinks, mineral water, and milk; cup-shaped containers for semi-solid foods / seasonings such as fruits, jelly, pudding, yogurt, mayonnaise, miso, processed rice, cooked food, and soups; and dish-shaped containers for raw meat, processed meat products (ham, bacon, sausages, etc.), rice, and pet food.

[0265] Example

[0266] The present invention will be described in more detail below with examples, but the present invention is not limited to the following examples as long as it does not depart from its spirit. It should be noted that unless otherwise specified, "parts" and "%" refer to the mass standard.

[0267] Before implementing the examples, prepare the following ingredients.

[0268] [EVA(A)]

[0269] • C14 EVA (A1): EVA derived from biomass resources (manufactured by Braskem, SVT2145R), ethylene content 95 mol%, vinyl acetate content 14 wt%, MFR (190℃, loading 2160g) 2.1g / 10min, bio-based content 88%.

[0270] • Petroleum-derived EVA (A2): EVA derived from petroleum feedstock (manufactured by Tosoh Corporation, Ultrathene 630), ethylene content 95 mol%, vinyl acetate content 15 wt%, MFR (190℃, 2160g load) 1.5g / 10min, density 0.936g / cm³ 3

[0271] [EVA saponification (B)]

[0272] • EVA saponification (B1): EVA saponification derived from petroleum feedstock (manufactured by Tosoh Corporation, MELTHENEH0051K), ethylene content 89 mol%, degree of saponification 99 mol%, MFR (190℃, load 2160g) 6.5g / 10 minutes

[0273] [Polyolefin resin (C)]

[0274] • Polyolefin resin (C1): Polypropylene (manufactured by Nippon Polypropylene Co., Ltd., NOVATEC (registered trademark) EA9), MFR (230℃, load 2160g) 0.5g / 10min

[0275] [Adhesive resin]

[0276] Maleic anhydride-grafted modified ethylene-propylene random copolymer, MFR (230℃, 2160g load) 3.2g / 10min

[0277] [EVOH(D)]

[0278] • EVOH (D1): EVOH (ethylene content 32 mol%, saponification degree 99.9 mol%), MFR (190℃, load 2160g) 3.8g / 10 minutes

[0279] [Hydrotalcite (E)]

[0280] • Hydrotalcite (E1): Hydrotalcite solid solution (manufactured by Kyowa Chemical Industry Co., Ltd., ZHT-4A)

[0281] [Higher fatty acid metal salts (F)]

[0282] • Higher fatty acid metal salts (F1): Calcium stearate (Nissan Oils & Fats Co., Ltd.)

[0283] [Titanium compound (G)]

[0284] • Titanium compound (G1): Titanium oxide (manufactured by Wako Pure Chemical Industries, Ltd.)

[0285] [Antioxidants]

[0286] • Pentaerythritol tetra-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Ciba Specialty Chemicals, IRGANOX 1010)

[0287] <<The First Approach>>

[0288] <Example 1-1>

[0289] 85 parts of EVA containing C14 (A1), 5 parts of EVA saponification (B1), 5 parts of hydrotalcite (E1), 5 parts of higher fatty acid metal salt (F1), and 0.05 parts of antioxidant were dry-mixed and then fed into a twin-screw mixer at a rate of 8 kg / h using a mass feeder. The mixture was then cut into granules using a drum granulator to prepare granular resin composition (X). The mixing conditions are as described below.

[0290] [Mixing Conditions]

[0291] • Twin-screw extruder: Diameter 20mm, L / D=48 (Manufactured by Toshiba Machine Co., Ltd.)

[0292] • Extruder set temperature (°C): C1 / C2 / C3 / C4 / C5 / C6 / H=120 / 150 / 160 / 160 / 170 / 170 / 170

[0293] Screw speed: 250 rpm

[0294] • Traction speed: 12m / min

[0295] <Examples 1-2~1-4, Comparative Examples 1-1, 1-2>

[0296] As shown in Table 1 below, the types and mixing amounts of each component were changed, except that the 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.

[0297] The following thermal stability and color inhibition evaluations were performed using the resin compositions (X) of Examples 1-1 to 1-4, and Comparative Examples 1-1 and 1-2. These results are shown together in Table 1 described below.

[0298] [Thermal stability evaluation (10% temperature reduction)]

[0299] Using 5 mg of the obtained granular resin composition (X), a thermogravimetric analyzer (Perkin Elmer, Pyris 1 TGA) was used to determine the temperature at which the resin composition (X) decreased in mass to 90% (10% reduction temperature) under nitrogen atmosphere, gas flow rate of 20 mL / min, and temperature range of 30–550 °C. A higher value indicates slower decomposition of the resin composition (X), signifying excellent thermal stability.

[0300] In addition, the evaluation is based on the following criteria.

[0301] A (Excellent): 10% reduction in temperature to above 370.0℃

[0302] B (Excellent): 10% reduction in temperature to above 367.5℃ and below 370.0℃.

[0303] C (Good): 10% reduction in temperature to above 362.5℃ and below 367.5℃

[0304] D (Difference): 10% reduction in temperature to less than 362.5℃

[0305] [Staining inhibition assessment (ratio of YI values)]

[0306] The granular resin composition (X) was pulverized at 650 rpm using a pulverizer (manufactured by Sometani Sangyo Company Limited, SKR16-240) to produce pulverized material with a diameter of 1-5 mm.

[0307] The obtained pulverized material was filled into a cylinder with an inner diameter of 32 mm and a height of 30 mm. The yellow index (YI value) before heating was measured using a spectrophotometer (manufactured by Nippon Denshoku Kogyo Co., Ltd.) while the material was smoothed.

[0308] In addition, the pulverized material was heat-treated in an oven at 60°C for 3 days under air atmosphere, and the YI value after heating was measured in the same way. The ratio of the YI value after heating to the YI value before heating was calculated. The larger the value, the more yellow the resin composition (X) is after heating.

[0309] In addition, the evaluation is based on the following criteria.

[0310] A (Excellent): The ratio of YI value is below 1.0.

[0311] B (Very Good): The ratio of YI values ​​is greater than 1.0 and less than 3.5.

[0312] C (Good): The ratio of YI value is greater than 3.5 and less than 5.0.

[0313] D (Difference): The ratio of YI values ​​is greater than 5.0.

[0314] [Table 1]

[0315]

[0316] As shown in Table 1, the resin compositions (X) of Examples 1-1 to 1-4, which used EVA (A1) containing carbon-14 as the EVA, exhibited improved thermal stability compared to Comparative Examples 1-1 and 1-2, which used EVA (A2) derived from petroleum. Furthermore, a comparison between Examples 1-2 and Comparative Example 1-1 revealed that color inhibition was also improved when using EVA (A1) containing carbon-14. This is attributed to the improved color inhibition properties of EVA (A1) containing carbon-14. 14 C) EVA has a stronger binding energy due to the primary isotope effect, thus decomposing slowly, having improved thermal stability, and can achieve synergistic effects with hydrotalcite (E1) and higher fatty acid metal salts (F1).

[0317] Moreover, it is known that even if the mixing ratio and type of each component change, the excellent thermal stability and color inhibition of the products in Examples 1-1 to 1-4 can still be obtained.

[0318] It should be noted that, as can be seen from Examples 1-1 and Comparative Examples 1-2, when the resin composition (X) contains a titanium compound (G1), the thermal stability and yellowing inhibition are improved by using EVA (A1) containing carbon 14 instead of EVA (A2) derived from petroleum, and the color inhibition is also excellent in the products of Examples 1-1 to 1-4.

[0319] <<Second Method>>

[0320] <Example 2-1>

[0321] The recycled material was pulverized to obtain recycled pulverized material, which consisted of a layer of polyolefin resin (C1) and a layer of EVOH (D1) separated by an adhesive resin layer. This recycled pulverized material, along with EVA containing C14 (A1), EVA saponified material (B1), hydrotalcite (E1), and higher fatty acid metal salts (F1) in the proportions shown in Table 2, was dry-mixed and then fed into a twin-screw mixer at a rate of 8 kg / h using a mass feeder. The mixture was then cut into granules using a drum granulator to prepare granular resin composition (Y). It should be noted that the mixing conditions are as described below.

[0322] [Mixing Conditions]

[0323] • Twin-screw extruder: Diameter 20mm, L / D=48 (Manufactured by Toshiba Machine Co., Ltd.)

[0324] • Extruder set temperature (°C): C1 / C2 / C3 / C4 / C5 / C6 / H=120 / 150 / 160 / 160 / 170 / 170 / 170

[0325] Screw speed: 250 rpm

[0326] • Traction speed: 12m / min

[0327] <Examples 2-2~2-5, Comparative Example 2-1>

[0328] As described in Table 2 below, the types and mixing amounts of each component were changed. Otherwise, the 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.

[0329] The thermal stability and color inhibition were evaluated using the resin compositions (Y) of Examples 2-1 to 2-5 and Comparative Example 2-1. These results are shown in Table 2 below.

[0330] [Thermal stability evaluation (5% temperature reduction)]

[0331] Using 5 mg of the obtained particulate resin composition (Y), a thermogravimetric analyzer (Perkin Elmer, Pyris 1 TGA) was used to determine the temperature at which the resin composition (Y) decreased in mass to 95% (5% reduction temperature) under nitrogen atmosphere, gas flow rate of 20 mL / min, and temperature range of 30–550 °C. A higher value indicates slower decomposition of the resin composition (Y), signifying excellent thermal stability.

[0332] In addition, the evaluation is based on the following criteria.

[0333] A (Excellent): 5% reduction in temperature above 380.0℃

[0334] B (Excellent): 5% reduction in temperature above 375.0℃ and below 380.0℃.

[0335] C (Good): 5% reduction in temperature above 372.5℃ and below 375.0℃

[0336] D (Difference): 5% reduction in temperature less than 372.5℃

[0337] [Evaluation of staining inhibition (difference in YI values)]

[0338] The granular resin composition (Y) was pulverized at 650 rpm using a pulverizer (manufactured by Sometani Sangyo Company Limited, SKR16-240) to produce pulverized material with a diameter of 1-5 mm.

[0339] The obtained pulverized material was filled into a cylinder with an inner diameter of 32 mm and a height of 30 mm. The yellow index (YI value) before heating was measured using a spectrophotometer (manufactured by Nippon Denshoku Kogyo Co., Ltd.) while the material was smoothed.

[0340] In addition, the pulverized material was heat-treated in an oven at 60°C for 3 days under air atmosphere, and the YI value after heating was measured in the same way. The difference between the YI value after heating and the YI value before heating was calculated. The larger the value, the more yellow the resin composition (Y) is after heating.

[0341] In addition, the evaluation is based on the following criteria.

[0342] A (Excellent): The difference in YI values ​​is less than 0.20.

[0343] B (Excellent): The difference in YI values ​​is greater than 0.20 and less than 0.30.

[0344] C (Good): The difference in YI values ​​is greater than 0.30 and less than 0.40.

[0345] D (Difference): The difference in YI values ​​is 0.40 or higher.

[0346] [Table 2]

[0347]

[0348] As shown in Table 2, compared with Comparative Example 2-1 which uses petroleum-derived EVA (A2), the resin compositions (Y) of Examples 2-1 to 2-5, which use EVA (A1) containing 14 carbon atoms and are used with components (C) to (E) contained in laminated recycled materials, have improved thermal stability and color inhibition.

[0349] As the reason given, it is believed to contain carbon-14 ( 14 C) EVA has a stronger binding energy due to the primary isotope effect, thus its decomposition is slower, its thermal stability is improved, and it also exhibits synergistic effects with hydrotalcite (E1) and higher fatty acid metal salts (F1).

[0350] In particular, a comparison of Example 2-1 with Comparative Example 2-1 shows that the color inhibition is significantly improved when using EVA containing C14 compared to petroleum-derived EVA (A2).

[0351] Moreover, it is known that even if the mixing ratio and type of each component change, the excellent thermal stability and color inhibition of the products in Examples 2-1 to 2-5 can still be obtained.

[0352] The above embodiments illustrate specific aspects of the present invention, but these embodiments are merely illustrative and not intended to be limiting. Various modifications that will be apparent to those skilled in the art are included within the scope of the present invention.

[0353] Industrial availability

[0354] Compared to resin compositions using petroleum-derived EVA, this resin composition (X) exhibits improved thermal stability and colorfastness. Therefore, molded articles formed from this resin composition (X), and multilayer structures having layers containing this resin composition (X), are useful as materials for various packaging containers, i.e., packaging bodies and food packaging. Furthermore, this resin composition (X) is useful as a recycling aid for recycled resins containing polyolefin resins and EVOH.

[0355] Furthermore, compared to resin compositions using petroleum-derived EVA, this resin composition (Y) exhibits improved thermal stability and colorfastness. Therefore, molded articles formed from this resin composition (Y), and multilayer structures having layers containing this resin composition (Y), are useful as materials for various packaging containers, i.e., packaging bodies and food packaging. In particular, this resin composition (Y) is useful as a recycled resin composition using recycled resins containing polyolefin resins and EVOH.

Claims

1. A resin composition X comprising an ethylene-vinyl acetate copolymer A, the ethylene-vinyl acetate copolymer A contains carbon 14.

2. A resin composition X comprising an ethylene-vinyl acetate copolymer A and an ethylene-vinyl acetate copolymer saponate B having an ethylene content of more than 60 mol%, the ethylene-vinyl acetate copolymer A and / or the ethylene-vinyl acetate copolymer saponate B contains carbon 14.

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

4. The resin composition X according to claim 2, wherein, the bio-based content of the ethylene-vinyl acetate copolymer A and / or the ethylene-vinyl acetate copolymer saponate B having an ethylene content of more than 60 mol% is 1 to 100%.

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

6. The resin composition X according to claim 1 or 2, wherein, the bio-based content of the ethylene-vinyl acetate copolymer A is 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 a recycling 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 for a recycling aid.

10. A recycling 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- ethylene vinyl alcohol copolymer D having an ethylene content of 60 mol% or less.

13. A resin composition Y comprising an ethylene-vinyl acetate copolymer A, a polyolefin resin C and an ethylene-ethylene vinyl alcohol copolymer D, the ethylene-vinyl acetate copolymer A contains carbon 14.

14. A resin composition Y comprising an ethylene-vinyl acetate copolymer A, an ethylene-vinyl acetate copolymer saponate B having an ethylene content of more than 60 mol%, a polyolefin resin C and an ethylene-ethylene vinyl alcohol copolymer D, the ethylene-vinyl acetate copolymer A and / or the ethylene-vinyl acetate copolymer saponate B contains carbon 14.

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 higher fatty acid metal salt F.

17. The 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 a higher fatty acid calcium salt, a higher fatty acid magnesium salt and a higher fatty acid zinc salt.

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 recycled material layer comprising the recycling aid according to claim 10.

21. A multi-layered structure comprising the recycled material layer according to claim 20.

22. The multi-layered structure according to claim 21, further comprising a layer comprising a polyolefin resin, which layer does not comprise the ethylene-vinyl acetate copolymer A.

23. The multi-layered structure according to claim 21, further comprising an adhesive resin layer different from the recycled material layer, which adhesive resin layer does not comprise the ethylene-vinyl acetate copolymer A.

24. A package comprising the multilayer structure according to claim 21.

25. A food package comprising the multilayer structure according to claim 21.

26. A method for producing a recycling aid, comprising a step of mixing an ethylene-vinyl acetate copolymer A and an ethylene-vinyl acetate copolymer saponate B having an ethylene content of more than 60 mol%, the ethylene-vinyl acetate copolymer A and / or the ethylene-vinyl acetate copolymer saponate B contains carbon 14.

27. A method for producing a recycling material layer by shaping a resin composition, comprising a step of mixing a polyolefin resin C, an ethylene-vinyl alcohol copolymer D, an ethylene-vinyl acetate copolymer A and an ethylene-vinyl acetate copolymer saponate B having an ethylene content of more than 60 mol%, in the resin composition, the ethylene-vinyl acetate copolymer A and / or the ethylene-vinyl acetate copolymer saponate B contains carbon 14.

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