JP2659027B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of the Invention The present invention relates to a film-forming property of a blend composition of a thermoplastic resin, a saponified ethylene-vinyl acetate copolymer and an unsaturated carboxylic acid or its derivative-modified polyolefin. It relates to a significantly improved composition.

B. Prior Art A thermoplastic resin and a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) and an unsaturated carboxylic acid or its derivative-modified polyolefin (hereinafter abbreviated as a modified polyolefin) blend composition are characterized by: Has certain physical properties. For example, at the time of multilayer co-extrusion molding of a thermoplastic resin and EVOH and a modified polyolefin, instead of the thermoplastic resin or the EVOH layer, a layer of the blend composition may be used, or the thermoplastic resin and the EVOH layer may be provided in the middle of the layer. By providing the layer of the blend composition, the interlayer adhesion can be improved. In addition, a blend composition of a thermoplastic resin, EVOH, and a modified polyolefin suppresses the transmission of oxygen gas as compared with the thermoplastic resin, so that the food can be prevented from being altered by oxygen gas. The characteristics of such a blend composition of a thermoplastic resin, EVOH and a modified polyolefin are widely known, and various attempts have been made to utilize them by a so-called extrusion molding method. Furthermore, multi-layer coextrusion molding using a combination of a thermoplastic resin, EVOH, and a modified polyolefin is widely performed, and unnecessary materials (a blend composition of a thermoplastic resin, EVOH, and a modified polyolefin) generated during the multilayer molding are removed. It was desired to improve the economic efficiency by carrying out collection.

However, this composition generally has poor film-forming properties at the time of extrusion molding, and when formed into films, sheets, bottles, and the like,
In fact, a good molded product could not be obtained due to remarkable impairment of the appearance or peeling inside the blend composition.

On the other hand, by mixing different types of polymers to improve properties,
There are many methods for improving processability, and a block copolymer hydrogenated product comprising a vinyl aromatic compound and a conjugated diene compound (hereinafter abbreviated as a block copolymer hydrogenated product) as one component, or It is known to use the unsaturated dicarboxylic acid derivative (hereinafter abbreviated as hydrogenated modified block copolymer). For example, JP-A-58-74
No. 43 describes that a block copolymer hydrogenated product is used by blending with a polar thermoplastic polymer, but judging from examples of the patent, the patent relates to improvement of mechanical properties by blending. There is no technical idea regarding the improvement of the film forming property and the co-extrusion moldability (defective appearance, peeling) of the present invention.

C. Problems to be Solved by the Invention The present invention relates to a resin composition comprising a thermoplastic resin (A), EVOH (B) and a modified polyolefin (C), which has poor film-forming properties, and a molded product such as a film to be obtained. It is intended to improve the poor appearance.

D. Means for Solving the Problem The problem is to include a block copolymer hydrogenated product (D) within a specific range in the thermoplastic resin (A), EVOH (B), and modified polyolefin (C). Solved by

The present inventors have studied various methods for improving the film forming property of a blend composition of a thermoplastic resin (A), EVOH (B) and a modified polyolefin (C) and obtaining an extruded product with a beautiful appearance. It has been found that when both the modified polyolefin (C) and the hydrogenated block copolymer (D) are present, a remarkable effect of improving the film-forming properties can be obtained. When the modified polyolefin (C) is not present, there is little effect of improving the film forming property, it is difficult to obtain a good molded product, and a new abnormality occurs in which a gel-like thermally degraded resin is mixed in the molded product, resulting in poor molding. This is surprising compared to what you can only get.

In addition, the present inventors have proposed a modified block copolymer hydrogenated product (b) obtained by subjecting an unsaturated carboxylic acid or a derivative thereof to an addition reaction within a specific range with a block copolymer hydrogenated product (a).
Was found to be more easily obtained by incorporating the above-mentioned blend composition into an extruded product having a beautiful appearance and free from abnormalities such as peeling inside the layer and mixing of a gel-like thermally degraded resin.

That is, more specifically, (A) + (B), (A) +
In the blend system of (B) + (C) and (A) + (B) + (D), the effect of improving abnormalities is small, but (A) + (B) +
It was found that the blend system of (C) + (D) exhibited an unexpected improvement effect at a specific composition ratio as described later.
Further, it was found that the composition (D) in the composition had a better effect when (a) + (b) was used than when only (a) was used.

Further, the composition includes a metal salt of ethylenediamineatetraacetic acid, a hydrotalcite-based compound, or a metal salt of a higher fatty acid, such as Group I, Group II, and Group III of the periodic table.
It has been found that blending at least one kind of salt or oxide (E) containing at least one element selected from the group has a further improving effect, thereby completing the present invention. These facts are clear from the examples described later.

In the present invention, examples of the thermoplastic resin (A) include low-water-absorbing thermoplastic resins, such as polyolefin, polyester, polyamide, polystyrene, polycarbonate, and polyvinyl chloride. These may be used alone or in combination of two or more. Used. Among these, polyolefin and polystyrene are preferred.

Examples of the polyolefin include high-, medium-, or low-density polyethylene, vinyl acetate, acrylates, or polyethylenes copolymerized with α-olefins such as butene, hexene, and 4-methyl-1-pentene, ionomer resins, and polypropylene. Homopolymer,
Polypropylene obtained by graft polymerization of ethylene, polypropylene obtained by copolymerizing α-olefins such as ethylene, butene, hexene, and 4-methyl-1-pentene; modified polypropylene obtained by blending a rubber-based polymer; poly 1-butene; Contains methyl-1-pentene. Of these, polyethylene and polypropylene resins are important in that the compatibility with EVOH is particularly poor and the effects of the present invention are particularly remarkable.

Polystyrene is a resin containing at least 25% by weight or more of a structural unit represented by the following general formula in the resin.

(Where R is a hydrogen atom or a methyl group, Z is a halogen atom or a methyl group, and p is an integer of 0 or 1-3.) Specifically, polystyrene, rubber-modified polystyrene, styrene-acrylonitrile copolymer And homopolymers and copolymers of styrene and its derivatives exemplified by styrene-butadiene-acrylonitrile copolymer and the like. A blend of these resins with a styrene-conjugated diene block copolymer rubber and a hydrogenated product thereof is also applicable.

Polyamides are produced by polycondensation reaction of ω-aminocarboxylic acid or polycondensation reaction of dibasic acid and diamine, 6-nylon, 6-6-nylon, 6-10-nylon, 11-nylon, 12-nylon. Nylon and copolymers thereof, and particularly, a copolymer polyamide resin of ε-caprolactam and hexamethylene diammonium adipate is preferable.

The polyester is obtained by polymerization of a saturated dibasic acid and glycols, for example, polyethylene terephthalate obtained from ethylene glycol and terephthalic acid, phthalic acid, isophthalic acid, sebacic acid,
Polyethylene terephthalate copolymer containing a saturated dibasic acid such as adipic acid, azelaic acid, glutaric acid, succinic acid, and oxalic acid as a copolymer component, and 1,4-cyclohexanedimethanol, diethylene glycol, propylene glycol, and the like as a diol component Is a copolymer component of polyethylene terephthalate or polybutylene or a blend thereof.

In the present invention, EVOH (B) is a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20 to 60 mol%, preferably 25 to 50 mol%, and a saponification degree of the vinyl acetate component of 90%. As described above, preferably, 95% or more can be used. If the ethylene content is less than 20 mol%, the melt moldability is poor.
If it is more than 60, the gas barrier properties will be insufficient. Also, the degree of saponification
If it is less than 90%, the gas barrier properties and thermal stability will be poor. In addition, the EVOH may contain other monomers [for example, polypropylene, butylene, and the like, as long as the object of the present invention is not hindered.
Unsaturated carboxylic acid or its ester (meth) acrylic acid, (meth) acrylic acid ester (methyl, ethyl)
｝, Vinylsilane compounds (vinyltrimethoxysilane, triethoxysilane, etc.), vinylpyrrolidone (N
-Vinylpyrrolidone, etc.]] can also be copolymerized. This EVOH contains a plasticizer, a heat stabilizer, an ultraviolet absorber,
It is also free to blend antioxidants, colorants, fillers, and other resins (such as partially saponified ethylene-vinyl acetate copolymer).

Further, a suitable melt index (MI) of the EVOH used in the present invention (a value measured at 190 ° C under a load of 2160 g; Plotted with the reciprocal of the absolute temperature on the horizontal axis and the melt index on the vertical axis on a semilog graph, extrapolated to 190 ° C) 0.1 to 50 g / 10 min, optimally 0.5 to 20 g / 10 min It is.

The modified polyolefin (C) in the present invention is an unsaturated carboxylic acid or a derivative thereof modified polyolefin, for example, an unsaturated carboxylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid or the like. Saturated carboxylic acids, esters or anhydrides thereof; methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate,
A polyolefin resin modified with at least one selected from the group consisting of unsaturated carboxylic acid derivatives such as butyl methacrylate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, sodium acrylate and sodium methacrylate; Here, as the polyolefin resin, polyethylene, polypropylene, ethylene-vinyl acetate, acrylate copolymer and the like are preferable.

Examples of the hydrogenated block copolymer (D) in the present invention include a hydrogenated block copolymer (a) composed of a conjugated diene compound of a vinyl aromatic compound. (A)
Is composed of a vinyl aromatic compound polymer block (S) and a conjugated diene compound block (O) whose degree of unsaturation does not exceed 20%, and is generally represented by the structure of S—O or S—O—S. However, the molecular structure may be linear, branched, radial, or a combination thereof, and the SO structure and the SOS structure may be used in combination. The content of the vinyl aromatic compound in the component (D) is 10 to 90% by weight, preferably 10 to 50% by weight, and the vinyl aromatic compound is one or two kinds selected from styrene, α-methylstyrene, vinyltoluene and the like. You can select and use more than species,
As conjugated diene compounds, butadiene, isoprene,
One or more selected from 1,3-pentadiene can be used.

Further, as the component (D), 0.1 to 10 parts by weight of an unsaturated carboxylic acid or a derivative thereof is added to 100 parts by weight of the hydrogenated block copolymer (a) composed of the above-mentioned vinyl aromatic compound and conjugated diene compound. And a modified block copolymer hydrogenated product (b) modified by an addition reaction. The addition amount of the unsaturated carboxylic acid or its derivative is more preferably 1 to 5 parts by weight because of an improvement effect.

By using a blend of the above (a) and (b) as the component (D), more excellent effects can be obtained, but the mixing ratio (weight ratio) at that time is (a) / (b) = 1 / 99-99
/ 1 is preferred, and more preferably 10/90 to 90/10. It is also free to use as a blend of combinations in which the content of each vinyl aromatic compound in (a) and (b) is different.

Examples of unsaturated carboxylic acids or derivatives thereof added to the block copolymer hydrogenated product (a) include acrylic acid,
Methacrylic acid, maleic acid, fumaric acid, crotonic acid,
Unsaturated carboxylic acids such as itaconic acid and citraconic acid, esters or anhydrides thereof; unsaturated carboxylic acid derivatives such as acrylamide, methacrylamide, sodium acrylate and sodium methacrylate; Acids are preferred.

The compounding ratio of the resin composition of the present invention is such that EVOH (B) is 10 to 200 parts by weight, preferably 10 to 150 parts by weight based on 100 parts by weight of the thermoplastic resin (A). The modified polyolefin (C) and the hydrogenated block copolymer (D) are EVOH
0.1 to 3 (weight ratio) to (B), preferably 0.5 to 3
~ 2 (weight ratio).

When the modified polyolefin (C) has a weight ratio of less than 0.1 or 3 or more with respect to the EVOH (B), a small amount of gel and lumps are generated in both cases, resulting in poor appearance. The block copolymer hydrogenated product (D) is used in a weight ratio with respect to EVOH (B).
If it is less than 0.1, slight turbulence occurs in the sheet, and the improvement effect becomes small. If the weight ratio is 3 or more, a small amount of gel and lumps are generated, and the appearance becomes poor. These are clear from the comparative examples.

In the present invention, by using the modified polyolefin (C) and the block copolymer (D) in combination, the moldability of the melt-molded product of the polyolefin (A) and the EVOH (B) is remarkably improved, and The mechanisms that prevent exfoliation are not fully understood, but polyolefins and EVs
It is presumed that the synergistic effect of the modified polyolefin and the block copolymer works effectively in a state where the rheological effect and the dispersing action in the OH melt system are intricately combined.

Next, in the present invention, group I, group II and group II of the periodic table
It is further preferable to mix at least one kind (E) of a salt or oxide containing at least one element selected from Group I from the viewpoint of preventing gel generation. Here, for example, a number of compounds are listed. Among them, oxides such as calcium oxide, magnesium oxide, barium oxide and zinc oxide, metal (Group I, Group II or Group III) salts of fatty acids, and metal of ethylenediaminetetraacetic acid (I Group, group II or III
Group) salts or hydrotalcites are effective. Further, it has been found that salts containing a metal element belonging to Group II of the periodic table, such as magnesium, calcium, and zinc, are particularly effective in these compounds. Examples of the fatty acids of metal (Group I, Group II or Group III) salts of fatty acids include lower aliphatic acids such as acetic acid, propionic acid, butyric acid, caproic acid, and caprylic acid; and higher fatty acids such as lauric acid, stearic acid, and myristic acid. Is mentioned. Among them, metal salts of higher fatty acids having 8 to 22 carbon atoms, particularly calcium salts, magnesium salts and zinc salts, are particularly suitable for the purpose of the present invention. Metal (group I, group II or group III) salts of ethylenediaminetetraacetic acid include disodium salt, trisodium salt, tetrasodium salt, dipotassium salt, tripotassium salt, tetrapotassium salt, disodium monomagnesium salt, disodium salt Monocalcium salt, disodium monoiron salt, disodium monozinc salt, dipotassium monomagnesium salt and the like are preferred. In particular, as a hydrotalcite compound, M _x Al
_y (OH) _{2X + 3Y-2Z} (A) _Z · aH ₂ O (M is Mg, Ca or Z
u and A are CO ₃ or HPO ₄ , x, y, z and a are integers and a is 0
And a hydrotalcite compound which is a double salt represented by the following formula. Examples of such compounds include the following.

_{Mg 6 Al 2 (OH) 16} CO 3 · 4H 2 O Mg 8 Al 2 (OH) 20 CO 3 · 5H 2 O Mg 5 Al 2 (OH) 14 CO 3 · 4H 2 O Mg 10 Al 2 (OH) 22 _{(CO 3) 2 · 4H 2} O Mg 6 Al 2 (OH) 16 HPO 4 · 4H 2 O Ca 6 Al 2 (OH) 16 CO 3 · 4H 2 O Zu 6 Al 6 (OH) 16 CH 3 · 4H 2 O These hydrotalcite compounds not only improve the compatibility of EVOH with the polyolefin, but also improve the hue of the resulting moldings.

Addition amount of additive (E) in resin composition ｛(A) +
The blending ratio with respect to the total amount of (B) + (C) + (D)} is preferably 0.001 to 10% by weight, particularly preferably 0.01 to 5% by weight. If it exceeds 10% by weight, various properties other than the compatibility are impaired, which is not preferable in many cases. Additive (E)
One or more types are used.

As a method for blending (E), when directly used in dry blending, when the dispersibility is insufficient, or when good results cannot be obtained, the resins (A), (B),
It is preferable that a predetermined amount is previously blended with either (C) or (D) before use, and it is particularly preferable to blend with (A) before use.

As a method for obtaining the composition of the present invention, a method of blending a block copolymer hydrogenated product (D) with a composition containing a thermoplastic resin (A), EVOH (B) and a modified polyolefin (C), 1 of (A), (B) or (C)
A method of blending (D) with a species or more, and further using one of (A), (B) or (C) or a composition containing (A), (B) and (C) Further, there is a method of blending (D). Among them, the blend of (D) or (D) + (A) or the blend of (D) + (C) is (A)
A method of blending with the compositions (B) and (C) is effective.

The blending method is not particularly limited, and examples thereof include a dry blending method and a pre-pelletizing method using a single-screw or twin-screw extruder. Among them, a pre-pelletizing method using a single-screw extruder having a kneading unit is preferable. It is valid.

Also, when blending, the moisture absorption of the raw materials, especially the composition containing EVOH, should be avoided.
It is preferable to dry at 0 ° C. for 6 to 24 hours so that the moisture content in EVOH is 1% by weight or less, preferably 0.5% by weight or less.

In addition, the resin composition of the present invention may be blended with, for example, a thermoplastic resin, for example, a polyolefin, and other conventional additives. Examples of such additives include antioxidants, ultraviolet absorbers, plasticizers, antistatic agents, lubricants,
Coloring agents, fillers, and other high molecular compounds can be used, and these can be blended as long as the effects of the present invention are not impaired. Specific examples of the additives include the following.

Antioxidant: 2,5-di-t-butylhydroquinone, 2,6
-Di-t-butyl-p-cresol, 4,4'-thiobis- (6-t-butylphenol), 2,2'-methylene-
Bis (4-methyl-6-t-butylphenol), octadecyl-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate and the like.

UV absorber: ethylene-2-cyano-3,3-diphenylacrylate, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5) '-Methylphenyl) 5-
Chlorobenzotriazole, 2-hydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone and the like.

Plasticizer: dimethyl phthalate, diethylene phthalate, dioctyl phthalate, wax, liquid paraffin, phosphate ester and the like.

Antistatic agent: pentaerythritol monostearate, sorbitan monopalmitate, sulfated olein, polyethylene oxide, carbowax and the like.

Lubricants: ethylene bis stearamide, butyl stearate and the like.

Coloring agents: carbon black, phthalocyanine, quinacridone, indoline, azo pigments, titanium oxide, red iron, etc.

Fillers: glass fiber, asbestos, mica, ballastonite, calcium silicate, aluminum silicate,
Calcium carbonate and the like.

Many other high molecular compounds can also be blended to such an extent that the effects of the present invention are not impaired.

The resin composition of the present invention is not limited to film molding, but uses a well-known melt extrusion molding machine, compression molding machine, transfer molding machine, injection molding machine, blow molding machine, thermoforming machine, rotary molding machine, dip molding machine, and the like. And sheets, tubes, bottles,
The same effect as that of a film can be obtained by molding into an arbitrary molded product such as a cup.

When the resin composition of the present invention is used as one layer of a multilayer structure, it can have an arbitrary layer structure of two or more layers. As a suitable example of the layer constitution, when the resin composition of the present invention is represented by F, the thermoplastic resin is represented by A, the EVOH is represented by B, and the adhesive is represented by AD, the following layer constitution is obtained. Here, it is preferable to use the modified polyolefin (C) used in the present invention as AD.

2-layer A / F 3-layer A / F / B, F / B / F, F / AD / B 4-layer F / B / AD / A, A / F / AD / B 5-layer F / AD / B / AD / F, A / F / B / AD / A, A / F / B / F / A 6 layers A / F / AD / B / AD / A 7 layers A / F / AD / B / AD / F / A In such a multilayer structure, the resin composition of the present invention can be replaced with a scrap of the multilayer structure.

As a multilayer molding method, generally, a number of extruders corresponding to the type of the resin layer are used, and this extruder is used,
The best practice is a method of so-called co-extrusion, in which the flow of the resin melted in the extruder is simultaneously extruded in a superposed layer state. It is clear from the examples described later that the resin composition of the present invention is excellent in coextrusion moldability. As another method, a multilayer molding method such as extrusion coating and dry lamination may be employed.

Since the multilayer structure having the above-mentioned layer structure contains EVOH having excellent gas barrier properties, it is particularly useful as a food packaging material and a medical product (medicine, medical equipment, etc.) packaging material requiring gas barrier properties. is there. In particular, a multilayer structure composed of at least two layers of the EVOH (B) layer and the resin composition (F) layer is preferable because of its excellent gas barrier properties.

In the present invention, when the (F) layer is stretch-molded, for example, SPPF molding in a sheet (vacuum pressure air solid phase molding),
In the case of stretch blow molding or the like, the transparency of the molded product is increased because (D) and (C) are blended.
In some cases, the improvement is significant compared to a system in which (D) and / or (C) is not blended.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Parts mean parts by weight.

E. Examples Example 1 In a four-type, seven-layer coextrusion plant, (A) PP (polypropylene), (B) EVOH (1) (ethylene content 32 mol%,
(C) Ad (1) modified polyolefin (maleic anhydride-modified PP) and (F) blend composition [(A) 65 parts of PP, (B) 20 parts of EVOH (1), Composition in which 10 parts of C) modified polyolefin and 5 parts of (D) block copolymer (hydrogenated styrene-butadiene block copolymer) are prepelleted at 230 ° C. by a single screw extruder having a kneading section in advance. ] Into four single-screw extruder hoppers, and (A) / (F) / (C) /
(B) / (C) / (F) / (A) sheet at 240 ° C
Molded at The thickness of each layer at this time is (A) = 150
μ, (B) = 300 μ, (C) = 20 μ, (B) = 60 μ, a total of 1000 μ, no bumps, gels, and blemishes were observed, and the appearance evaluation result was good. Even if this sheet is folded, cut with scissors, or knocked,
(F) Whitening and delamination due to delamination of the layer were not observed, and the evaluation result of delamination in the layer was good. The adhesive strength between layer (F) and layer (C) of the sheet was measured at 20 ° C. under the conditions of 90 ° peeling and a pulling speed of 100 mm / min. Heating the sheet to 150 ° C,
After performing vacuum pressure forming (SPPF solid-phase stretching molding), a molded product having good transparency was obtained, and a favorable evaluation result was obtained for the transparency of the SPPF molded product.

Examples 2 to 9 and Comparative Examples 1 to 7 A multilayer sheet was obtained under the same conditions as in Example 1 except that a raw material shown in Table 1 was used to prepare a (F) blend composition. The adhesive strength was measured under the same conditions. Further, the sheet was subjected to vacuum pressure forming under the same conditions as in Example 1. The evaluation results (sheet appearance bleeding, sheet appearance defects, gel, delamination in layer, adhesive strength, transparency of SPPF molded product) were all performed by the same person to eliminate individual differences.

Example 10 The same conditions as in Example 1 were used except that the (F) blend composition was prepared at 270 ° C. using the raw materials shown in Table 1 and a four-layer, seven-layered multilayer sheet was formed at 270 ° C. Carried out.

Sheet appearance ｛シ ー ト (wave pattern): Excellent = no film surface erosion of the molded product 優 = almost no film surface erosion of the molded product Good = 多少 膜 膜 多少 多少 多少 多少 多少 多少 ＝ ＝ ＝ ＝ ＝ ＝ ＝ The surface of the film is large, making it difficult to use in practice. Sheet appearance (gel / bud): Excellent = almost no gel / bud on the film surface of the molded product.

Good = There are some gel spots on the film surface of the molded product, but there is no practical problem. Poor = Many gel spots or large gel spots are recognized on the film surface of the molded product. Transparency (visual evaluation): Excellent = Cloudy, No partial whitening part Good = Cloudy Slightly no practical problem Poor = Cloudy, partial whitening, practically difficult to use PP: Polypropylene HDPE: High density polyethylene HIPS: Impact resistant polystyrene PET: Polyethylene terephthalate EVOH (1) : Ethylene content 32 mol%, saponification degree 99.6%
EVOH EVOH (2): ethylene content 44 mol%, saponification degree 99.4%
EVOH Ad (1): maleic anhydride-modified polypropylene Ad (2): maleic anhydride-modified polyethylene Ad (3): maleic anhydride-modified ethylene-vinyl acetate copolymer Ad (4): maleic anhydride-modified ethylene-acryl Acid ethyl ester copolymer SOS (1): hydrogenated styrene-butadiene block copolymer (a) (styrene content 41% by weight, hydrogenation rate 96%) SOS (2): 100 parts by weight of SOS (1) (B) SOS (3): SOS (1) (a) and hydrogenated styrene-isoprene block copolymer (styrene content 14% by weight, hydrogenation rate 96) %) A mixture of 100 parts by weight of maleic anhydride and 3 parts by weight of addition reaction (b) in a 50/50 weight ratio (a / b). SOS is the styrene-butadiene-styrene S-
It shows that it is an OS block copolymer.

F. Effects of the Invention According to the present invention, a film-forming property and a co-extrusion moldability of a thermoplastic resin blend containing EVOH are remarkably improved, and a molded article having a beautiful appearance and excellent delamination resistance, especially A multilayer structure can be provided.

Claims (4)

(57) [Claims] 1. A thermoplastic resin (A), a saponified ethylene-vinyl acetate copolymer (B), an unsaturated carboxylic acid or its derivative-modified polyolefin (C), and a block copolymer comprising a vinyl aromatic compound and a conjugated diene compound. A saponified ethylene-vinyl acetate copolymer (B) comprising a hydrogenated polymer (D) and 100 parts by weight of a thermoplastic resin (A)
10 to 200 parts by weight, and the weight ratio of each of component (C) and component (D) to component (B) is 0.1 to
3. The resin composition according to item 3. 2. Component (D) is subjected to an addition reaction of an unsaturated carboxylic acid or a derivative thereof in an amount of 0.1 to 10 parts by weight per 100 parts of a hydrogenated block copolymer comprising a vinyl aromatic compound and a conjugated diene compound. The resin composition according to claim 1, which is a hydrogenated modified block copolymer (b). 3. A block copolymer hydrogenated product (a) wherein the component (D) comprises a vinyl aromatic compound and a conjugated diene compound, and an unsaturated dicarboxylic acid or a derivative thereof. a) A modified block copolymer hydrogenated product (b) obtained by addition reaction of 0.1 to 10 parts by weight per 100 parts, and the ratio of component (a) to component (b) is (a) / (b) =
The resin composition according to claim 1, wherein the ratio is in the range of 1/99 to 99/1 (weight ratio). 4. The composition according to claim 1, which comprises at least one kind of salt or oxide (E) containing at least one element selected from Group I, Group II and Group III of the periodic table. The resin composition as described in the above.