WO2005105437A1

WO2005105437A1 - Multi-layer structure and process for production thereof

Info

Publication number: WO2005105437A1
Application number: PCT/JP2005/008018
Authority: WO
Inventors: Nahoto Hayashi; Hiroyuki Shindome; Tomoyuki Watanabe; Naoki Kataoka
Original assignee: Kuraray Co., Ltd.
Priority date: 2004-04-28
Filing date: 2005-04-27
Publication date: 2005-11-10
Also published as: JPWO2005105437A1

Abstract

A multi-layer structure comprising a layer of an ethylene/vinyl alcohol copolymer (A), a layer of a carboxylic acid-modified polyolefin (B), a layer of a thermoplastic resin (C) having a solubility parameter of 11 or below, and a layer of a resin composition (E), characterized in that the resin composition (E) consists of the components (A), (B) and (C) and a thermoplastic resin (D) having at least one functional group selected from the group consisting of boron acid groups and boron-containing groups convertible into boron acid groups in the presence of water and that the layer of an ethylene/vinyl alcohol copolymer (A) and the layer of a thermoplastic resin (C) or a resin composition (E) are laminated through the layer of a carboxylic acid-modified polyolefin (B). The multi-layer structure permits effective reuse of the regrinds and is excellent in impact resistance and gas barrier properties.

Description

Specification

Multilayer structure and manufacturing method thereof

Technical field

The present invention relates to a multilayer structure including an ethylene-vinyl alcohol copolymer layer and a method for producing the same.

Background art

[0002] Ethylene bulcohol copolymer (hereinafter sometimes abbreviated as EVOH) has excellent gas barrier properties, and is used for packaging contents such as foods and pharmaceuticals, where maintaining the quality is important. Used as a material. In recent years, thanks to its excellent gasoline barrier properties, it has been widely used for fuel tanks. In particular, a laminate with a thermoplastic resin having excellent moisture-proof properties and mechanical properties such as polyolefin resin is preferably used because it can cover the weak points of EVOH. When manufacturing such a multilayered structure, regrind such as scraps of the product when the shape is a sheet or film, burrs for the end or defective, bottles for the bottle, punching scraps for the cup etc. (Scrap) inevitably occurs, and its reuse is required in terms of cost and resource saving.

[0003] In order to effectively reuse this regrind, a method is used in which a resin layer mainly composed of polyolefin resin is mixed with regrind (see Patent Document 1), and a thermoplastic polyolefin layer and EVOH are used. A method of interposing a regrind composition layer between the layers (see Patent Document 2) and the like have been proposed. For example, the layer structure of a general automotive gasoline tank composed of a high-density polyethylene, a barrier layer, an adhesive layer, and a regrind composition layer is (outer layer) regrind + high-density polyethylene layer Z adhesive layer Z rear layer Z Adhesive layer Z regrind + high-density polyethylene layer (inner layer), (outer layer) high-density polyethylene layer Z regrind composition layer Z adhesive layer Z barrier layer Z adhesive layer Z high-density polyethylene layer (inner layer) and the like.

[0004] In addition, in order to suppress interfacial peeling of the regrind composition layer, disorder of the layer, and generation of a wavy pattern, and to obtain a laminate having excellent impact resistance, a block copolymer specific to the regrind composition is used. Also known are methods of mixing body-graft polymers (for example, carboxylic acid-modified polyolefin) (see Patent Documents 3 and 4) and methods of mixing an antioxidant and a metal compound (see Patent Document 5). It is.

[0005] In spite of the various methods described above, when a regrind composition containing a polyolefin resin and EVOH is melt-extruded, the E VOH in the regrind composition is particularly high. The extruder tends to accumulate and deteriorate, resulting in the formation of black deposits (burns) inside the extruder and the attachment of gel-like substances (e.g. In many cases, it is difficult to continuously carry out extrusion molding of the resin.

[0006] As a method for solving the above problem, a thermoplastic resin having a boronic acid group or a boron-containing group that can be converted to a boronic acid group in the presence of water is used as an adhesive layer, and a regrind composition is prepared. There is known a method for reducing appearance abnormality and gel bumps (Patent Document 6). According to this method, the appearance abnormality of the regrind composition is reduced, but when the thermoplastic resin having the boron-containing group is used as the adhesive layer, the adhesive strength with the EVOH layer is too strong, and thus the carboxylic acid-modified polyolefin is used. There is a concern that the film surface appearance and moldability of the multilayer structure will be adversely affected as compared with the case of using such as the adhesive layer. In particular, when blow molding large multi-layer containers such as fuel containers, it is undeniable that the adhesive strength is too high, which may have an adverse effect on the parison's formability (draw-down property). In addition, since the use of the thermoplastic resin for the adhesive layer may lead to an increase in cost, the use of a carboxylic acid-modified polyolefin for the adhesive layer is preferred in terms of moldability and cost.

[0007] As described above, when the regrind composition obtained when the multilayer structure having the carboxylic acid-modified polyolefin layer is recovered is melt-kneaded as described above, the EVOH in the regrind composition may be melt-kneaded. Stagnation and deterioration, resulting in the formation of black deposits (burns) inside the extruder, and the attachment of gel-like substances (e.g. In fact, it is often difficult to perform molding continuously for a long time.

Patent Document 1: JP-A-51-95478

Patent Document 2: JP-A-59-101338

Patent Document 3: JP-A-5-147177

Patent Document 4: JP-A-8-27332

Patent Document 5: JP-A-9-302170 Patent Document 6: JP-A-7-329252

Disclosure of the invention

Problems to be solved by the invention

[0009] The present invention has been made to solve the above problems, and has as its object to obtain a multilayer structure excellent in impact resistance, gas barrier properties, and appearance. It is another object of the present invention to provide a method for producing a multilayer structure which can effectively utilize a regrind and has excellent thermal stability and melt moldability.

Means for solving the problem

[0010] The above problems, an ethylene content of 5 to 60 mole ^_0/0, 85% or more of ethylene Bulle alcohol copolymer saponification degree (A) layer, a carboxylic acid-modified polyolefin (B) layer, 11 the following solubility parameter A multi-layered structure having a thermoplastic resin (C) layer having a (Fedors formula force) and a resin composition (E) layer; wherein the resin composition (E) is an ethylene-vinyl alcohol copolymer. At least one selected from the group consisting of a polymer (A), a carboxylic acid-modified polyolefin (B), a thermoplastic resin (C), and a boron-containing group that can be converted to a boronic acid group in the presence of a boronic acid group and water. It consists of a thermoplastic resin (D) having one functional group, and has a layer of ethylene-butyl alcohol copolymer (A), thermoplastic resin (C) or resin composition (E). Multi-layer structure characterized by lamination via carboxylic acid-modified polyolefin (B) layer Solved by providing the body.

At this time, the resin composition (E) 1S ethylene-butyl alcohol copolymer (A) 1 to 40% by weight, the carboxylic acid-modified polyolefin (B) 0.1 to 39.1% by weight, It is preferred that the thermoplastic resin (C) is 59.8 to 98.8% by weight and the thermoplastic resin (D) is 0.1 to 39.1% by weight. It is also preferable that the thermoplastic resin (C) is a substantially unmodified polyolefin. It is also preferable that the content of the boron-containing group in the thermoplastic resin (D) is 0.001 to 2 meq / g. The thermoplastic resin (D) is a polyolefin having at least one functional group selected from the group consisting of a boronic acid group and a boron-containing group that can be converted to a boronic acid group in the presence of water, and particularly preferably from 0.85 to Polyethylene having a density of 0.94 gZcm ³ is preferable.

[0012] An extruded product, a blow molded product, a thermoformed product and a fuel container comprising the multilayer structure are It is a preferred embodiment of the present invention.

[0013] Further, the above-mentioned problem is further addressed by a regrind obtained from a multilayer structure having an ethylene-vinyl alcohol copolymer (A) layer, a carboxylic acid-modified polyolefin (B) layer and a thermoplastic resin (C) layer. It is also solved by providing a method for producing the above-mentioned multilayer structure, characterized in that a thermoplastic resin (D) is added and melt-kneaded to form the resin composition (E) layer. You.

[0014] At this time, in addition to the above-mentioned regrind force ethylene-butyl alcohol copolymer (A) layer, carboxylic acid-modified polyolefin (B) layer, and thermoplastic resin (C) layer, a resin composition (E) ) It is preferable that a multilayer structure having a layer is obtained. It is also preferable to add 0.1 to 30 parts by weight of the thermoplastic resin (D) to the total of 100 parts by weight of the regrind and the thermoplastic resin (D) added thereto and melt-knead the mixture. It is. Coextrusion or coinjection molding is also preferred.

[0015] When the regrind of the multilayer structure having the ethylene-vinyl alcohol copolymer (A) layer, the carboxylic acid-modified polyolefin (B) layer and the thermoplastic resin (C) layer is recovered and used, boronic acid groups and A thermoplastic resin (D) having at least one functional group selected from the group consisting of boron-containing groups that can be converted to a boronic acid group in the presence of water is added to the regrind and melt-kneaded. Improves the compatibility of EVOH (A), carboxylic acid-modified polyolefin (B) and thermoplastic resin (C) in the resin composition (E) to be used, and improves the impact resistance and thermal stability Is improved. The reason for this is not clear, but it is presumed that the boron-containing functional group of the thermoplastic resin (D) and the hydroxyl group of the EVOH (A) are bonded by transesterification during melt kneading.

[0016] Conventionally, the carboxylic acid-modified polyolefin (B) contained in the regrind composition is thermally degraded when the number of times of recovery is increased, and the compatibility with the EVOH (A) in the regrind composition gradually decreases. However, the dispersibility of EVOH (A) was poor. As a result, aggregation and thermal degradation of EVO H (A) in the regrind composition occurred. However, when the thermoplastic resin (D) having a boron-containing functional group is added to the regrind, the dispersibility of the EVOH (A) in the regrind composition does not deteriorate even if the number of collections is increased. It was found that the aggregation and thermal degradation of EVOH (A) in the regrind composition were suppressed. The reason is not always clear, The thermoplastic resin (D) having a boron-containing functional group in the regrind composition prevents a decrease in the dispersibility of EVOH (A) in the regrind composition due to the thermal deterioration of the rubonic acid-modified polyolefin (B). It is estimated that Therefore, the effect of improving the recoverability by adding the thermoplastic resin (D) having a boron-containing functional group to the regrind is more remarkably exhibited by increasing the number of times of recovery.

The invention's effect

[0017] The multilayer structure of the present invention is excellent in impact resistance, gas nolia property and appearance. In addition, when regrind of a multilayer structure having an ethylene vinyl alcohol copolymer (A) layer, a carboxylic acid-modified polyolefin (B) layer and a thermoplastic resin (C) layer is recovered and used, a boron-containing material is used. By blending thermoplastic resin (D) having a group with regrind, the melt moldability and thermal stability of the regrind composition are improved, and the impact strength of the multilayer structure is dramatically improved. improves.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

As the EVOH (A) used in the present invention, those obtained by saponifying an ethylene-butyl ester copolymer are preferable. As the butyl ester, a fatty acid butyl ester such as butyl propionate or burivalate can be used as a typical example of the butyl acetate.

[0019] The ethylene content of the EVOH (A) is required to be 5 to 60 mol ^_0/0. The lower limit of the ethylene content is preferably at least 15 mol%, more preferably at least 20 mol%. The upper limit of the ethylene content is preferably 55 mol% or less, more preferably 50 mol% or less. If the ethylene content of EVOH is less than 5 mol%, the melt moldability of the resin composition containing EVOH deteriorates. On the other hand, when the ethylene content exceeds 60 mol%, the barrier properties of the resin composition containing EVOH are insufficient.

[0020] It is necessary that the saponification degree of the bullet ester component of EVOH (A) is 85% or more. The degree of saponification is preferably at least 90%, more preferably at least 99%. If the degree of saponification is less than 85%, the resin composition containing EVOH will have insufficient nolia properties and thermal stability. In the production of EVOH (A), a known method of copolymerizing ethylene with one or more vinyl esters and saponifying the resulting ethylene-vinyl acetate copolymer can be employed. . At this time, 0.003 to 0.2 mol% of the bullsilani conjugate can be contained as the third copolymer component. Examples of the vinylsilane-based compound include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (j8-methoxy-ethoxy) silane, and y-methallyloxypropylmethoxysilane. Of these, burtrimethoxysilane and burtriethoxysilane are preferably used. Furthermore, other monomers, for example, α-olefins such as propylene and butylene; (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate and the like, as long as the object of the present invention is not impaired. Unsaturated carboxylic acids and esters thereof; and butylpyrrolidones such as Ν-pyrrolidone; and the like.

[0022] EVOH (Α) may be a mixture of two or more different types of EVOH! /. In this case, エチレン The ethylene content and the degree of saponification of VOH (A) shall be average values calculated from the blending weight ratio.

[0023] EVOH (A) may contain a boron compound as long as the object of the present invention is not impaired. Examples of the boron compound include boric acids, borate esters, borates, borohydrides, and the like. Specifically, the boric acids include orthoboric acid, metaboric acid, tetraboric acid, etc., the boric acid esters include triethyl borate, trimethyl borate, and the like. Examples thereof include alkali metal salts and alkaline earth metal salts of boric acids, and borax. Of these compounds, orthoboric acid is preferred.

When a boron compound is blended, the content of the boron compound is preferably from 20 to 2000 ppm, more preferably from 50 to LOOO ppm in terms of boron element. When the content of the boron compound is in a strong range, torque fluctuation is suppressed during heating and melting of EVOH. If the content of the boron compound is less than 20 ppm, the effect of improving the suppression of torque fluctuation may be insufficient, and if it exceeds 2000 ppm, EVOH may be gelled and may immediately have poor moldability.

[0025] Further, when EVOH (A) is used alone as one layer constituting a multilayer structure, as described later, an alkali metal salt may be added to EVOH (A) to improve interlayer adhesion. This is preferable because it is effective for improving the above-mentioned properties. The content of the alkali metal salt is preferably from 5 to 5000 ppm, more preferably from 20 to LOOO ppm, and still more preferably from 30 to 500 ppm, in terms of an anorekadi metal element. Examples of the alkali metal include lithium, sodium, and potassium, and examples of the alkali metal salt include an aliphatic carboxylate, an aromatic carboxylate, a phosphate, and a metal complex. Specific examples include sodium acetate, potassium acetate, sodium phosphate, lithium phosphate, sodium stearate, potassium stearate, and sodium ethylenediaminetetraacetate. Of these, sodium acetate, potassium acetate and sodium phosphate are preferred.

[0026] It is also preferable to add a phosphorus compound to EVOH (A), since the melt moldability and thermal stability of EVOH (A) can be improved. The content of the phosphorus compound is preferably 2 to 200 ppm, more preferably 3 to 150 ppm, and still more preferably 5 to 10 ppm in terms of gin element. When the content of the phosphorus conjugate is less than 2 ppm or more than 200 ppm, there may be a problem in the melt formability and thermal stability of EVOH. In particular, when performing melt molding for a long time, problems such as generation of gel-like bubbles and coloring are likely to occur.

[0027] The type of the phosphorus compound to be incorporated into the EVOH (A) is not particularly limited, and for example, various acids such as phosphoric acid and phosphorous acid, and salts thereof can be used. The phosphate may be added in any form of a primary phosphate, a secondary phosphate, or a tertiary phosphate, and the cation species which may be added is not particularly limited. And alkaline earth metal salts. Among these, it is preferable to add the phosphorous conjugate in the form of sodium dihydrogen phosphate, potassium dihydrogen phosphate, disodium hydrogen phosphate, and dipotassium hydrogen phosphate.

[0028] Furthermore, a heat stabilizer, an ultraviolet absorber, an antioxidant, a colorant, and a plasticizer such as glycerin or glycerin monostearate are blended with EVOH (A) within a range not to impair the object of the present invention. You can also. Further, the addition of a metal salt of a higher aliphatic carboxylic acid, a talcite compound, or the like is effective from the viewpoint of preventing deterioration of EVOH (A) due to heat.

[0029] Examples of the metal salt of a higher aliphatic carboxylic acid include metal salts of higher fatty acids having 8 to 22 carbon atoms. Specifically, lauric acid, stearic acid, myristic acid and the like can be mentioned. Examples of the metal include sodium, potassium, magnesium, calcium, zinc, norium, aluminum and the like. Of these, magnesium, calcium and barium are preferred.

[0030] As a hydrated talcite compound, in particular, M Al (OH) (A) · aH O (M is M

2x + 3y-2z 2 g, represents Ca or Zn, A represents CO or HPO, and x, y, z, a are positive numbers)

3 4

Hydrate talcite conjugate which is a double salt. Particularly preferred examples include the following hydrated mouth talcite conjugates.

[0031] Mg Al (OH) CO · 4Η O

6 2 16 3 2

Mg Al (OH) CO-5H O

8 2 20 3 2

Mg Al (OH) CO -4H O

5 2 14 3 2

Mg Al (OH) (CO) -4H O

10 2 22 3 2 2

Mg Al (OH) HPO -4H O

6 2 16 4 2

Ca Al (OH) CO -4H O

6 2 16 3 2

Zn Al (OH) CO -4H O

6 6 16 3 2

Mg Al (OH) CO-3.5H O

4.5 2 13 3 2

[0032] Further, in addition to the above-mentioned examples, hydrated tars such as [MgZn] Al (OH) (CO) .0.45HO described in JP-A-1-308439 may be used. Site system

0.75 0.25 0.67 0.33 2 3 0.167 2

Solid solutions can also be used.

[0033] The content of the metal salt of these higher aliphatic carboxylic acids or the talcite compound of Hideguchi is preferably 0.01 to 3 parts by weight, more preferably 0 to 100 parts by weight of EVOH (A). 05 to 2.5 parts by weight.

The melt flow rate (MFR) of EVOH (A) (at 190 ° C. under a load of 2160 g) is preferably from 0.1 to 50 g / 10 min, more preferably from 0.3 to 40 g / 10 min. , And more preferably, 0.5 to 30 g / l 0 minutes. However, for EVOH with a melting point near 190 ° C or exceeding 190 ° C, measure at multiple temperatures above the melting point under a load of 216 Og, and use the semilog graph to plot the reciprocal of absolute temperature on the horizontal axis and the log of MFR on the vertical axis. Plot it on the axis and extrapolate to 190 ° C as the MFR.

As the carboxylic acid-modified polyolefin (B) used in the present invention, in particular, a copolymer (X-olefin and an unsaturated carboxylic acid or an anhydride thereof) is preferably used. , Polyolefin having a carboxyl group in the molecule, carboxy contained therein Polyolefins in which all or part of the radicals are present in the form of metal salts can also be used. Examples of the polyolefin as a base of the carboxylic acid-modified polyolefin (B) include polyethylene (eg, high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and ultra-low-density polyethylene (VLDPE). )), Polypropylene, copolymerized polypropylene, ethylene-butyl acetate copolymer, ethylene (meth) acrylate copolymer, and various other polyolefins.

[0036] Examples of the unsaturated carboxylic acid as a copolymer component include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, monomethyl maleate, monoethyl maleate, itaconic acid and the like, and among these, acrylic acid And methacrylic acid are preferred. The content of the unsaturated carboxylic acid is preferably 0.5 to 20 mol ^_0/0, more preferably 〖This is 3 to 12 mol% is preferably from 2 to 15 mole ^_0/0, further. Examples of the unsaturated carboxylic anhydride include itaconic anhydride and maleic anhydride. Of these, maleic anhydride is preferable. Content ί unsaturated force Norebon acid anhydride or suitably ί or 0.0001 to 5 Monore ^_0/0, more preferably ί or 0.0005 to 3 mole ^_0/0, even more preferably 0.001 it is to 1 mol ^_0/0.

Examples of the metal ion in the metal salt of the carboxylic acid-modified polyolefin include an alkali metal such as lithium, sodium and potassium; an alkaline earth metal such as magnesium and calcium; and a transition metal such as zinc. The degree of neutralization of the carboxylic acid-modified polyolefin in the metal salt is preferably 100% or less, more preferably 90% or less, even more preferably 70% or less, preferably 5% or more, more preferably Is at least 10%, even more preferably at least 30%.

[0038] The carboxylic acid-modified polyolefin (Β) may contain a monomer other than the above as a copolymer component. Other monomers include vinyl esters such as vinyl acetate and vinyl propionate; methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, η-butyl acrylate, 2-ethylhexyl acrylate, Unsaturated carboxylic acid esters such as methyl methacrylate, isobutyl methacrylate and getyl maleate; carbon monoxide and the like.

[0039] The melt flow rate (MFR) (190 ° C, under a load of 2160 g) of the carboxylic acid-modified polyolefin (Β) is preferably not less than 0.05 OlgZlO min, more preferably not less than 0.05 gZ min. Yes And still more preferably 0.1 lgZlO or more. Further, the MFR is preferably not more than 50 gZlO, more preferably not more than 30 gZlO, even more preferably not more than lOgZlO. These carboxylic acid-modified polyolefins can be used alone or as a mixture of two or more.

As the thermoplastic resin (C) having a solubility parameter of 11 or less (Fedors formula force is used) used in the present invention, for example, polyolefin resin, styrene resin, polychlorinated vinyl resin And the like. Examples of the polyolefin resin include α-olefin homopolymers such as high-density polyethylene, low-density polyethylene, polypropylene, and polybutene-1; α-olefins selected from ethylene, propylene, butene-11, hexene-1 and the like. And copolymers of the above-mentioned α-olefin with vinyl compounds such as diolefin, vinyl chloride and vinyl acetate, and unsaturated carboxylic esters such as acrylic acid esters and methacrylic acid esters. Styrene resins include polystyrene, acrylo-tolyl-butadiene-styrene copolymer resin (ABS), acrylonitrile-styrene copolymer resin (AS), styrene isobutylene block copolymer, and styrene butadiene copolymer. And a styrene isoprene block copolymer. These thermoplastic resins (C) can be used alone or as a mixture of two or more. Here, the thermoplastic resin (C) is at least one selected from the group consisting of a carboxylic acid-modified polyolefin (B), a boronic acid group, and a boron-containing group capable of converting to a boronic acid group in the presence of water. A resin other than the thermoplastic resin (D) having two functional groups, having the above-mentioned solubility parameter.

[0041] The thermoplastic resin (C) not only has a good balance of various physical properties, but also has a wide variety of commercially available products, is easily available, and is inexpensive. It is suitable as the main component in (E). In addition, since these thermoplastic resins (C) are used as the main material layers of many multilayer structures for the same reason, they are inevitable when the multilayer structures are collected and reused. Included in the regrind. For example, in the case of fuel container applications, from the viewpoint of impact resistance, polyolefin resin, which is one of the above thermoplastic resins (C), is often used in the outermost layer. Also contains the polyolefin resin. The thermoplastic resin (C) is preferably used as a substantially unmodified polyolefin. Fins. Substantially unmodified means that a functional group containing an element other than carbon and hydrogen is actively introduced.

[0042] The melt flow rate (MFR) of the thermoplastic resin (C) (at 190 ° C under a load of 2160 g) is preferably at least 0.0 OlgZlO min, more preferably at least 0.02 gZ min. . The MFR is preferably not more than 5 gZlO, more preferably not more than 2 gZlO. In particular, high-density polyethylene used in fuel containers is required to have high impact resistance, so it should have a low MFR and preferably 0.3 gZlO or less. It is more preferable that: In the case of using such a high-viscosity resin, it is often difficult to recover and use the resin. These thermoplastic resins (C) can be used alone or as a mixture of two or more.

[0043] In the thermoplastic resin (D) having a boron-containing functional group used in the present invention, the boronic acid group is represented by the following formula (I).

[0044] [Formula 1]

[0045] Further, the boron-containing group capable of converting to a boronic acid group in the presence of water refers to a compound capable of undergoing hydrolysis in the presence of water to be converted to a boronic acid group represented by the above formula (I). Refers to a boron-containing group. More specifically, water alone, a mixture of water and an organic solvent (toluene, xylene, acetone, etc.), a mixture of a 5% boric acid aqueous solution and the above organic solvent, etc., as a solvent, at room temperature to 150 ° C. A functional group that can be converted to a boronic acid group when hydrolyzed for 10 minutes to 2 hours below. Representative examples of such a functional group include a boronic ester group represented by the following formula (II), a boronic anhydride group represented by the following formula (ΠΙ), and a boronic acid base group represented by the following formula (IV) And the like. [0046]

[0047]

[0048]

[Wherein X and X are the same or different and each represent a hydrogen atom, an aliphatic hydrocarbon group (carbon

1 2

A linear or branched alkyl group or alkenyl group having a prime number of 1 to 20), an alicyclic hydrocarbon group (cycloalkyl group, cycloalkenyl group, etc.), and an aromatic hydrocarbon group (phenyl group, biphenyl) Wherein an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group may have a substituent, and X and X may be bonded to each other.

1 2

However, X and X are not both hydrogen atoms. R, R and R are above

1 2 1 2 3 X and the same hydrogen atom, aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic as X

1 2

Represents a group hydrocarbon group, and M represents an alkali metal. } In the above formula, examples of the substituent which the aliphatic hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group can have include, for example, a carboxyl group and a halogen atom.

[0050] Specific examples of the boronic ester group represented by the general formula (II) include a dimethyl ester boronate group, a getyl boronate group, a dipropyl boronate group, and a diboronic acid group. Sopropyl ester group, dibutyl boronate group, dihexyl boronate group, dicyclohexyl boronate group, ethylene glycol ester boronate group, propylene glycol ester boronate group, 1,3 propanediol ester boronate group 1,3-butanediol boronate ester, neopentylglycolester boronate, catechol ester boronate, glycerol ester boronate, trimethylolethane ester boronate, trimethylolpropane boronate, And a boronic acid diethanolamine ester group.

[0051] Examples of the boronate group represented by the general formula (IV) include an alkali metal base of boronic acid. Specific examples include sodium boronate base and potassium boronate base.

[0052] Among such boron-containing functional groups, a boronic acid cyclic ester group is preferable from the viewpoint of thermal stability. Examples of the boronic acid cyclic ester group include a boronic acid cyclic ester group containing a 5- or 6-membered ring. Specific examples include a boronic acid ethylene glycol ester group, a boronic acid propylene glycol ester group, a boronic acid 1,3 propanediol ester group, a boronic acid 1,3 butanediol ester group, and a boronic acid glycerin ester group.

The content of the boron-containing functional group is not particularly limited, but is preferably 0.001 to 2 meqZg (mmolZg) based on the weight of the thermoplastic resin (D). When the content of the boron-containing functional group is less than 0.001mZg, the effect of improving the compatibility may be insufficient. Therefore, the melt moldability and thermal stability of the regrind composition may be insufficient, and the impact strength of the multilayer structure may be insufficient. The content is more preferably 0.04meqZg or more, and still more preferably 0.04meqZg or more. On the other hand, when the content of the boron-containing functional group exceeds 2 meqZg, gel may be generated in the resin composition (E). More preferably, it is 0.5 meqZg or less, and still more preferably, it is 0.2 meqZg or less.

[0054] The boron-containing functional group is bonded to the main chain, side chain or terminal of the thermoplastic resin by a boron carbon bond. Among them, a form in which the functional group is bonded to a side chain or a terminal is preferable, and a form in which the functional group is bonded to a terminal is more preferable. Here, one end or both ends Means. The carbon in the boron-carbon bond is derived from a thermoplastic resin base polymer described later or from a boron compound reacted with the base polymer.

[0055] Specific examples of the thermoplastic resin (D) having a boron-containing functional group include polyethylene (ultra low density, low density, medium density, and high density), ethylene vinyl acetate copolymer, and ethylene acrylate ester. Polymer, metal salt of ethylene acrylic acid copolymer (Na, Κ, Zn ionomer), polypropylene, ethylene propylene copolymer, ethylene and 1-butene, isobutene, 3-methylpentene, 1-hexene, 1- Polyolefin resin such as a copolymer with α-olefin such as otaten; graft-modified polyolefin such as maleic anhydride and glycidyl methacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; styrene Monohydrogenated butadiene block copolymer, styrene Hydrogenated isoprene copolymer, styrene Monohydrogenated butadiene Styrene mono-hydrogenated isoprene Styrene mono-hydrogenated isoprene Styrene mono-hydrogenated gen block copolymer resin such as styrene block copolymer; Polymethyl acrylate, polyethyl acrylate, polymethyl methacrylate (Meth) acrylic acid ester resins; halogenated butyl resins such as polychlorinated butyl and bi-lidene fluoride; semi-aromatic polyester resins such as polyethylene terephthalate and polybutylene terephthalate; polyvalerolatone And aliphatic polyester resins such as polyproprolataton, polyethylene succinate and polybutylene succinate. One of these may be used alone, or two or more thereof may be used in combination. Among them, polyolefin and styrene monohydrogenated diblock copolymer are preferably used, and polyolefin is particularly preferably used.

When a propylene-based polymer is used as the thermoplastic resin (D) having a boron-containing functional group, the hot water resistance is improved. Extremely useful. When an ethylene-based polymer or a styrene-hydrogenated gen-block copolymer resin is used as the thermoplastic resin (D), the impact resistance is improved. For example, it is useful as a packaging material for bottles, tubes, cups, and pallets. On the other hand, for fuel containers such as gasoline tanks, it is necessary to use an ethylene polymer with good fuel resistance as the thermoplastic resin (D). Is preferred. In particular, it is preferable because it gives a multilayered structure having a density of 0.85-0.94 gZcm ³ and excellent strength and impact resistance of polyethylene. Since there is a tendency that the impact resistance higher density of the polyethylene is low is improved, and further preferably is at 0. 92gZcm ³ or less is more preferred instrument 0. 91gZcm ³ below. On the other hand, the density of the polyethylene when it is less than 0. 85gZcm ^3, there is a possibility that the handling is difficult, it is 0. 87 g / cm ³ or more is more preferred instrument 0. 88gZcm ³ or more Is more preferred.

Next, a typical method for producing the thermoplastic resin (D) having a boron-containing functional group used in the present invention will be described.

[0058] First method: A thermoplastic resin containing an olefinic double bond is reacted with a borane complex and a trialkyl borate under a nitrogen atmosphere to contain a boronic acid alkyl ester group. A method of reacting water or alcohols as necessary after obtaining a thermoplastic resin. In this way, a boron-containing functional group is introduced into the thermoplastic double bond of the thermoplastic resin by an addition reaction.

[0059] The olefinic double bond is introduced into a terminal by, for example, disproportionation at the time of termination of radical polymerization, or is introduced into a main chain or a side chain by a side reaction during polymerization. In particular, the polyolefin resin described above is capable of easily introducing an olefinic double bond by thermal decomposition under oxygen-free conditions, copolymerization of a gen compound, and the like. The coalesced resin is preferred in that by controlling the hydrogenation reaction, an olefinic double bond can be appropriately left.

[0060] The content of double bonds in the thermoplastic resin as a raw material is preferably 0.01 to 2 meq / g, and 0.02 to: LmeqZg is more preferable. By using such a raw material, it becomes easy to control the amount of the boron-containing functional group to be introduced. In addition, the amount of the olefinic double bond remaining after the introduction can be controlled at the same time.

The borane complex is preferably a borane-tetrahydrofuran complex, a borane-dimethylsulfide complex, a borane-pyridine complex, a borane-trimethylamine complex, a borane-triethylamine complex, or the like. Among these, borane-dimethylsulfide complex, borane-trimethylamine complex and borane-triethylamine complex are more preferable. The amount of the borane complex to be charged is in the range of 1 to 3 equivalents to 10 equivalents to the olefinic double bond of the thermoplastic resin. preferable.

[0062] The trialkyl borate is preferably a lower alkyl borate such as trimethyl borate, triethyl borate, propyl borate and tributyl borate. The amount of the trialkyl borate to be charged is preferably in the range of 1 to: LOO equivalent to the olefinic double bond of the thermoplastic resin. The solvent need not be particularly used, but when used, a saturated hydrocarbon solvent such as hexane, heptane, octane, decane, dodecane, cyclohexane, ethylcyclohexane, and decalin is preferable. The reaction temperature is usually in the range of room temperature to 300 ° C, and the reaction is carried out at a temperature in this range, preferably 100 to 250 ° C, for 1 minute to 10 hours, preferably 5 minutes to 5 hours. Good.

[0063] The boronic acid dialkyl ester group introduced into the thermoplastic resin by the above reaction can be hydrolyzed to a boronic acid group by a known method. Also, an arbitrary boronic ester group can be obtained by transesterification with alcohols by a known method. Furthermore, it can be dehydrated and condensed by heating to form a boronic anhydride group. Further, it can be further reacted with a metal hydroxide or a metal alcoholate by a known method to obtain a boronate group.

[0064] Such conversion of the boron-containing functional group is usually performed using an organic solvent such as toluene, xylene, acetone, or ethyl acetate. Examples of alcohols include monoalcohols such as methanol, ethanol, and butanol; ethylene glycol, propylene glycol, 1,3 propanediol, 1,3 butanediol, neopentyl glycol, glycerin, trimethylolmethane, pentaerythritol, dipentane And polyhydric alcohols such as erythritol. Examples of the metal hydroxide include hydroxides of alkali metals such as sodium and potassium. Further, examples of the metal alcoholate include those which are powerful with the above-mentioned metals and the above-mentioned alcohols. These are not limited to those in which the deviation is also exemplified. These are generally used in an amount of 1 to: LOO equivalent based on the boronic acid dialkyl ester group.

Second method: a known thermoplastic resin containing a carboxyl group, and a boronic acid or an amino group containing an amino group such as ethylene glycol ester of m-aminophenylbenzeneboronic acid and m-aminophenylboronic acid. The boronic acid ester contained is reacted with a known method. A method for amidation reaction. At this time, a condensing agent such as carbodiimide may be used. The boron-containing functional group thus introduced into the thermoplastic resin can be converted into another boron-containing functional group by the above-described method.

Examples of the thermoplastic resin containing a carboxyl group include those having a terminal carboxyl group such as semi-aromatic polyester resin and aliphatic polyester resin, polyolefin resin, styrene resin, and ) Acrylic ester resin, halogenated butyl resin, etc., into which a monomer unit having a carboxyl group such as acrylic acid, methacrylic acid, maleic anhydride, etc. is introduced by copolymerization, and the above-mentioned olefinic double bond Examples thereof include, but are not limited to, those in which maleic anhydride or the like is introduced into a thermoplastic resin containing

[0067] The resin composition (E) contained in the multilayer structure of the present invention comprises EVOH (A), carboxylic acid-modified polyolefin (B), and a heat-resistant resin having a solubility parameter of 11 or less (Fedors formula force calculation). A thermoplastic resin (C) and a thermoplastic resin (D) having at least one functional group selected from the group consisting of a boronic acid group and a boron-containing group capable of converting to a boronic acid group in the presence of water. Become.

[0068] The contents of the above raw materials in the resin composition (E) are as follows: EVOH (A) 1 to 40% by weight, carboxylic acid-modified polyolefin (B) 0.1 to 39.1% by weight, thermoplasticity. It is preferred that the resin (C) is 59.8 to 98.8% by weight and the thermoplastic resin (D) having a boron-containing group is 0.1 to 39.1% by weight. Here, the mixing ratio of each component (A) to (D) is a ratio when the total weight of (A) to (D) is 100% by weight. The mixing ratio of each component (A) to (D) is determined in consideration of the balance of various physical properties, availability, and price as described above. In particular, when the resin composition (E) is obtained by using the regrind of the multilayer structure, the compounding ratio of (A) to (C) depends on the performance required for the multilayer structure. In many cases, the mixing ratio is in the above range.

[0069] The content of EVOH (A) in the resin composition (E) is preferably 1 to 40% by weight! / ヽ. When the content of EVOH (A) is less than 1% by weight, there may be no problem in thermal stability even if the thermoplastic resin (D) having a boron-containing group is not blended. The need to employ the invention is reduced. The content of EVOH (A) is more preferably at least 2% by weight, More preferably, it is at least 3% by weight. On the other hand, when the content of EVOH (A) exceeds 40% by weight, impact resistance may be insufficient. The content of EVOH (A) is more preferably 30% by weight or less, further preferably 20% by weight or less, and particularly preferably 10% by weight or less.

[0070] The content of the carboxylic acid-modified polyolefin (B) in the resin composition (E) is preferably 0.1 to 39.1% by weight. When the content of the carboxylic acid-modified polyolefin (B) is less than 0.1% by weight, there is no problem in thermal stability even without blending the thermoplastic resin (D) having a boron-containing group. In some cases, the need to employ the present invention is reduced. The content of carboxy phosphate-modified polyolefin (B) is more preferably 0.3 wt ^_0/0 or more, and even more preferably 1 wt% or more. On the other hand, when the content of the carboxylic acid-modified polyolefin (B) exceeds 39.1% by weight, the resulting multilayer structure may have insufficient impact resistance. The content of the carboxylic acid-modified polyolefin (B) is more preferably 20% by weight or less, and still more preferably 10% by weight or less.

[0071] In the resin composition (E), the content of the thermoplastic resin (C) having a solubility parameter of 11 or less (also calculating the Fedors equation force) is 59.8 to 98.8% by weight. Preferably, there is. Since the main component of the resin composition (E) is the thermoplastic resin (C), the resin composition (E) can be used in the same manner as the thermoplastic resin (C). The content of the thermoplastic resin (C) is more preferably at least 75% by weight, even more preferably at least 89.4% by weight. On the other hand, when the content of the thermoplastic resin (C) exceeds 98.8% by weight, there is a problem in thermal stability even without blending the thermoplastic resin (D) having a boron-containing group. In some cases, the necessity of employing the present invention is reduced. The content of the thermoplastic resin (C) is more preferably 96.4% by weight or less, and still more preferably 95% by weight or less.

[0072] Thermoplastic having at least one functional group selected from the group consisting of a boronic acid group and a boron-containing group capable of converting to a boronic acid group in the presence of water in the resin composition (E). The content of the resin (D) is preferably 0.1 to 39.1% by weight. If the content of the thermoplastic resin (D) is less than 0.1% by weight, the compatibility of the components (A), (B) and (C) in the resin composition (E) May be insufficient, resulting in insufficient impact resistance, thermal stability, and appearance. In addition, when regrind is used to produce thermoplastic resin (D), continuous Extrusion molding may be difficult. The content of the thermoplastic resin (D) is more preferably at least 0.3% by weight, even more preferably at least 1% by weight, particularly preferably at least 3% by weight. In particular, when regrind is repeated and reused, the content of the thermoplastic resin (D) is preferably higher. On the other hand, when the content of the thermoplastic resin (D) exceeds 39.1% by weight, the cost increases. The content of the thermoplastic resin (D) is more preferably 20% by weight or less, and still more preferably 10% by weight or less.

[0073] The resin composition (E) is prepared by mixing the above-mentioned predetermined amounts of the components (A) to (D) using a conventional melt kneading apparatus such as a Banbury mixer, a single screw or twin screw extruder. It can be easily obtained by melt-kneading. The melt-kneading apparatus is not particularly limited. An extruder having a high degree of kneading is preferably used in order to uniformly blend 1S. In addition, in order to prevent the generation and mixing of gels and bubbles, it is preferable to seal the hopper port with nitrogen gas and extrude at a low temperature. At this time, an antioxidant, a plasticizer, a heat stabilizer, an ultraviolet absorber, an antistatic agent, a lubricant, a coloring agent, a filler, or another resin may be added as long as the effects of the present invention are not impaired.

[0074] In this case, all or a part of the individual components (A) to (C) may be used as a product generated in the production of a multilayer structure composed of layers containing the components (A) to (C). It is preferable to use it by replacing it with regrind such as dust, burrs, edges or defective products because the collected material can be reused effectively. The regrind is not limited to the one containing only the components (A) to (C). The thermoplastic resin having a boron-containing group (D), and the thermoplastic resin capable of forming a multilayer structure as described later. May contain fat. Since the size of the regrind is usually irregular V, it is preferable to grind it to an appropriate size and use force.

When the thermoplastic resin (D) having a boron-containing group is separately mixed with the above-mentioned regrind and melt-kneaded, the compatibility of the components (A) to (C) is dramatically improved, It becomes easy to continuously produce the regrind composition. Specifically, the regrind obtained from the multilayer structure having the EVOH (A) layer, the carboxylic acid-modified polyolefin (B) layer, and the thermoplastic resin (C) layer further includes a thermoplastic resin having a boron-containing group. It is preferable that the resin (D) is added and melt-kneaded to form a resin composition (E) layer. That is, a thermoplastic resin (D) having a boron-containing group is used as a recovery aid to be added when using regrind. At that time, in addition to the regrind force EVOH (A) layer, the carboxylic acid-modified polyolefin (B) layer, and the thermoplastic resin (C) layer, a resin composition (E ) It is more preferable that a multilayer structure having a layer is obtained. In this case, re-grinding is performed again using the multilayer structure having the resin composition (E) layer obtained by adding the thermoplastic resin (D) having a boron-containing group to the regrind and melt-kneading the raw material. This corresponds to the case of producing a multilayer structure having a resin composition (E) layer obtained by adding a thermoplastic resin (D) to the mixture and melt-kneading the resultant. That is, it corresponds to the case where the scrap collecting operation is performed again. Usually, when a multilayer structure having a regrind composition layer is continuously produced on an industrial scale, the use of regrind is a force that is repeated many times. It is possible to do.

[0077] To a total of 100 parts by weight of the regrind and the thermoplastic resin (D) added thereto, 0.1 to 30 parts by weight of a thermoplastic resin (D) having a boron-containing group is added and melted. It is preferred to knead. When the content of the thermoplastic resin (D) is less than 0.1% by weight, the compatibility of the components (A), (B) and (C) in the resin composition (E) And the impact resistance, thermal stability, and appearance may be insufficient. In addition, when the thermoplastic resin (D) is produced by using the regrind, it may be difficult to continuously extrude the resin or to repeatedly reuse the regrind. The addition amount of the thermoplastic resin (D) is more preferably at least 0.3 part by weight, still more preferably at least 1 part by weight, particularly preferably at least 3 parts by weight. On the other hand, when the addition amount of the thermoplastic resin (D) exceeds 39.1% by weight, the cost increases. The addition amount of the thermoplastic resin (D) is more preferably 20% by weight or less, and still more preferably 10% by weight or less.

[0078] In addition to the regrind containing the components (A) to (C) and the thermoplastic resin (D) having a boron-containing group, the component (C) is further mixed separately to form a resin composition (E ) Is also preferred. By doing so, a resin composition (E) having physical properties comparable to that of the component (C) itself is often obtained, for example, as a main material layer of a multilayer structure described later. Can also be used.

[0079] The multilayer structure of the present invention contains ethylene in addition to the layer comprising the resin composition (E). The amount 5 to 60 mole ^_0/0 calculated, 85% or more of ethylene Bulle alcohol copolymer saponification degree (A) layer, a carboxylic acid-modified polyolefin (B) layer, and 1 1 from the following equation of solubility parameter (Fedors ) Having a thermoplastic resin (C) layer. Moreover, the EVOH (A) layer and the thermoplastic resin (C) layer or the resin composition (E) layer are laminated via the carboxylic acid-modified polyolefin (B) layer. That is, the carboxylic acid-modified polyolefin (B) layer is used as an adhesive layer used between the (A) layer and the (C) or (E) layer. The carboxylic acid-modified polyolefin (B) has excellent adhesive properties, and also has excellent melt moldability when forming a multilayer structure, which is preferable in terms of cost.

[0080] In the multilayer structure of the present invention, in addition to the EVOH (A) layer, the carboxylic acid-modified polyolefin (B) layer, the thermoplastic resin (C) layer and the resin composition (E) layer, polyester (polyethylene terephthalate) , Polybutylene terephthalate, etc.), polyamide, polycarbonate, polychlorinated vinyl, polychlorinated bilidene, polyurethane, polyacetal and the like.

[0081] The layer configuration of the multilayer structure is not particularly limited, but for example, a four-layer configuration such as A / B / E / C, A / B / C / E; E / BZAZB / C, E / 5-layer configuration such as B / A / B / E, A / B / E / B ZC; 6-layer configuration such as C / B / A / B / E / C, EZBZAZBZEZC; E / B / A / B / A / B / C, CZEZBZAZBZEZC, etc .; In a multilayer structure including two or more layers of the same kind, for example, the EVOH (A) layer, the EVOH constituting each layer may be the same or different! /, Or! /. The same applies to other component layers. Further, it is also possible to provide a layer having another component force in the above-mentioned layer constitution. Among these, a multilayer structure having five or more layers is preferable because it can be used for various purposes with high practicality.

As a method for producing the multilayer structure of the present invention, known methods can be employed, and methods such as extrusion coating, co-extrusion molding, and co-injection molding can be used. Of these, co-extrusion molding or co-injection molding is preferably employed. After once obtaining a multilayer sheet or multilayer film by these methods, it is also possible to further perform co-stretching, pressure-stretching, thermoforming and the like.

[0083] Among these, coextrusion molding is preferable because the process is simple, a laminate having a complicated layer structure can be relatively easily produced, and the production cost can be suppressed. On the other hand, co-injection molding is not suitable for manufacturing a complex layer structure, but has a short production cycle and productivity. Is advantageous. In addition, although the process of thermoforming is complicated, it is possible to use a long-shaped container or the like which is difficult to manufacture by co-extrusion. The molding method is appropriately selected according to the shape, use, and the like of the obtained molded product.

[0084] Examples of the shape of the multilayer structure include sheets, films, cups, bottles, tubes, tanks, and the like, but are not limited thereto. The multilayer structure has various uses, and examples thereof include packaging materials or containers for foods, medicines, medical instruments, clothing, etc., and tubes and tanks for fuel (gasoline and the like). Of these, the most important fuel containers are described below.

[0085] The layer configuration when the multilayer structure is a fuel container is not particularly limited. However, in consideration of moldability and cost, (in) CZBZAZBZE (out), (in) CZBZA / B / E / C (outside), (inside) C / E / B / A / B / E / C (outside) are typical examples. Among them, the layer structure of (inner) C / B / A / B / E / C (outer) should be adopted from the viewpoint of rigidity, impact resistance, moldability, drawdown resistance, fuel resistance, etc. Is particularly preferred.

[0086] The thickness of each layer of the fuel container is not particularly limited. However, in consideration of the fuel barrier properties of the fuel container, mechanical strength, cost merit, etc., the thickness of the EVOH (A) layer is preferably the total layer thickness. Is at least 0.1%, more preferably at least 0.5%, even more preferably at least 1%. The thickness of the EVOH (A) layer is preferably 20% or less of the total layer thickness, more preferably 15% or less, and even more preferably 10% or less. Here, when there are a plurality of EVOH (A) layers, the total thickness of each EVOH (A) layer is defined as the thickness of the EVOH (A) layer. If the thickness of the EV OH (A) layer is less than 0.1% of the total layer thickness, the fuel barrier properties of the fuel container may be insufficient, and if it exceeds 20%, the cost may be relatively high. The mechanical strength may be insufficient.

[0087] The fuel container is preferably formed by co-extrusion blow molding. Specifically, a parison is formed by melt extrusion, the parison is sandwiched between a pair of blow molding dies, the parison is cut, and the opposing cut portions are fused, and then the parison is cut. Is expanded into the above-mentioned mold to form a fuel container. However, when the container becomes large such as a fuel tank for automobiles, the parison is sandwiched by the mold and crimped while the mold is pressed. In many cases, the part that is not part of the container and the surface force of the container is cut off at a desired height using a cutter or the like.

[0088] The fuel container can also be obtained by a method in which a multilayer sheet is separately thermoformed up and down, and these two molded articles are fused by heat welding or the like. In the case of this production method, it is possible to produce a tank having a long shape, which is difficult to produce especially by co-extrusion blow molding or the like.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples. In the following Synthesis Examples and Examples, unless otherwise specified, the ratio means a weight ratio, and “%” means “% by weight”. Melt flow rate (MFR) is a value measured at 190 ° C and a load of 2160 g unless otherwise noted. Intrinsic viscosity is the value measured at 30 ° C in a solution using a mixed solvent of 85% by weight of phenol and 15% by weight of water.

[0090] Synthesis example 1

Synthesis of high-density polyethylene having a boronic acid ethylene glycol ester group at its end: In a separable flask equipped with a condenser, stirrer, and dropping funnel, high-density polyethylene {M FRO. 3gZlO content (190 ° C, load 2160g), density 0 952 gZcm ³ , terminal double bond amount 0.048 meq / g (mmol / g)} 1000 g ゝ decalin 2500 g was charged, degassing was performed at room temperature under reduced pressure, and then nitrogen substitution was performed. To this were added 78 g of trimethyl borate and 5.8 g of borane-triethylamine complex. After reacting at 200 ° C. for 4 hours, a distillation apparatus was attached, and 100 ml of methanol was slowly added dropwise. After the completion of the dropwise addition of methanol, low boiling impurities such as methanol, trimethyl borate, and triethylamine were distilled off by distillation under reduced pressure. Further, 31 g of ethylene glycol was added, and the mixture was stirred for 10 minutes, then reprecipitated in acetone and dried to obtain 0.027 meq / g (mmol / g) of boronic acid ethylene glycol ester, 3 g of MFRO. A modified polyethylene (d-1: modified by BEAG HDPE) having a temperature of ° C, a load of 2160 g) and a density of 0.952 gZcm ³ was obtained. The amount of the boronic acid ethylene glycol ester group (BAEG) in the modified polyethylene was adjusted by using a mixed solution having a ratio of heavy para-xylene: polyethylene form: ethylene glycol = 8: 2: 0.02 as a solvent, 270MHz ^ — Quantified by NMR [0091] Synthesis example 2

Synthesis of ultra-low density polyethylene having boronic acid ethylene glycol ester group at the end In a separable flask equipped with a cooler, stirrer and dropping funnel, ultra-low-density polyethylene {MFR15gZlO content (190 ° C, load 2160g), density 0.9900gZcm ^{3. A} terminal double bond amount of 0.055meqZg} and 1000 g of decalin were charged, degassed by reducing the pressure at room temperature, and then replaced with nitrogen. To this were added 78 g of trimethyl borate and 5.8 g of borane-triethylamine complex. After reacting at 200 ° C. for 4 hours, a distillation apparatus was attached, and 100 ml of methanol was slowly added dropwise. After the completion of the dropwise addition of methanol, low-boiling impurities such as methanol, trimethyl borate, and triethylamine were distilled off under reduced pressure. Further, 31 g of ethylene glycol was added, and the mixture was stirred for 10 minutes, reprecipitated in acetone, and dried to obtain a boronic acid ethylene glycol ester group content of 0.050meqZg, an MFR of 15 gZlO (190.C, a load of 2160 g), and a density of 0. 900 g Zcm ³ of modified polyethylene (d-2: BEAG modified VLDPE) was obtained. The amount of the boronic acid ethylene glycol ester group (BAEG) in the modified polyethylene was determined in the same manner as in Synthesis Example 1.

[0092] Reference Example 1

The resulting modified polyethylene in Synthesis Example 1 (d-1: BEAG modified HDPE) 1 part by weight, the stock company Kuraray Co. EVOH "Ebaru (R) -F101" (ethylene content 32 mol ^_0/0, saponification degree 99. 5%, intrinsic viscosity 1. ldlZg) 5 parts by weight, maleic anhydride-modified polyethylene "Admer (registered trademark) GT6" manufactured by Mitsui Ichigaku Co., Ltd. {MFR: 0.994 ₈ 10 minutes (190, load 2160g)} 8 parts by weight and 86 parts by weight of Bassel's high density polyethylene “Lupolen (registered trademark) 426 1AG” {MFR0.03 gZlO content (190.C, load 2160 g), density 0.945 gZcm ³ } of a twin screw type The mixture was put into a vented extruder and extruded at 220 ° C. under a nitrogen atmosphere, and pelletized to obtain a resin composition pellet.

[0093] Film appearance evaluation

Using the pellets obtained, a film was prepared using the apparatus described below, and the appearance was evaluated.

Machine used: Twin screw extruder manufactured by Toyo Seiki Screw: 20mm φ, Funore flight

Extrusion temperature: 190/260/260/260 ° C

Film thickness: 100 / z m

[0094] Impact strength measurement

A test piece was prepared from the obtained pellet by injection molding using a single screw extruder, and the Izod impact strength was measured at −40 ° C. according to ASTM method D256. The impact strength measuring instrument was placed in a thermostatic chamber adjusted to 40 ° C, and the measurement sample was stored in the thermostatic chamber at least overnight before measurement, and then the impact strength was measured at 40 ° C.

[0095] Retained grease amount

An extrusion test was performed using the obtained pellets using the following apparatus. After kneading for 60 minutes, “Mirason 102” (LDPE) manufactured by Mitsui Igeraku Co., Ltd. was added, and kneading was performed for 45 minutes using the above resin. At this time, the test pellet also purged out the rotor upper force. After extracting the LDPE, the weight of the resin adhering to the rotor surface was measured. Machine used: Toyo Seiki extruder Brabender

Extrusion temperature: 220 ° C

Rotation speed: 50rpm

Kneading under nitrogen atmosphere for 60 minutes

Table 1 summarizes the above results.

[0096] Reference Examples 2 and 3

Pellets of the resin composition were obtained in the same manner as in Reference Example 1 except that the amount of the resin used was changed as shown in Table 1, and then the film appearance evaluation, impact strength measurement and retained resin amount measurement were performed. went. The results are summarized in Table 1.

[0097] Reference Example 4

Produced by Kuraray Co., Ltd. EVOH "Ebaru (R) -F101" (ethylene content 32 mol ^_0/0, saponification degree 99.5%, intrinsic viscosity 1. ldlZg) 5 parts by weight, manufactured by Mitsui Chemicals, Inc. maleic anhydride-modified 8 parts by weight of polyethylene "Admer (registered trademark) GT6" and 87 parts by weight of high density polyethylene "Lupolen (registered trademark) 4261AG" manufactured by Bassel are charged into a twin-screw type vented extruder, and subjected to a nitrogen atmosphere. Extrude at ° C and perform a plastic towel A product pellet was obtained. Using the obtained pellets, evaluation of film appearance, measurement of impact strength, and measurement of retained resin were performed in the same manner as in Example 1. The results are summarized in Table 1.

[0098] Reference Examples 5 to 7

A pellet of the resin composition was obtained in the same manner as in Reference Example 4 except that the amount of the resin used was changed as shown in Table 1, and then the film appearance evaluation, impact strength measurement, and retained resin amount measurement were performed. went. The results are summarized in Table 1.

[0099] [Table 1]

[0100] As can be seen from Table 1, a thermoplastic resin having a boron-containing functional group was added to a resin composition comprising EVOH (A), carboxylic acid-modified polyolefin (B), and thermoplastic resin (C). The addition of D) improved the appearance of the molded product, improved the impact strength, and further reduced the amount of retained resin. The effect becomes more remarkable as the amount of the thermoplastic resin (D) increases. It is considered that the addition of the thermoplastic resin (D) having a boron-containing functional group greatly contributes to the compatibility and thermal stability of each component.

[0101] Example 1

Produced by Kuraray Co., Ltd. EVOH "Ebaru (R) -F101" (ethylene content 32 mol ^_0/0, saponification degree 99.5%, an intrinsic viscosity 1. ldl / g) (EVOH), Mitsui I匕学Co. anhydride Using the maleic acid-modified polyethylene “Admer (registered trademark) GT6” (AD) and the high-density polyethylene “Lupolen (registered trademark) 4261 AG” (HDPE) manufactured by Bassel, the following multilayers were used. HDPEZADZEVOHZADZHDPE using extruder = 510/20/30/20

A sheet having a layer structure of Ζ420 / ζπι was prepared. Next, the obtained multilayer sheet was pulverized to an appropriate size so that it could be put into an extruder. 10 parts by weight of the modified polyethylene (d-1: BEAG-modified HDPE) obtained in Synthesis Example 1 was dry-blended to 90 parts by weight of the pulverized material to obtain a raw material for a recovery layer (Regl). Using this raw material and each of the above resins, a sheet having a layer configuration of HDPEZReglZADZEVOHZADZHDPE = 110Z400Z20Z30Z20 / 420 m was prepared using the multilayer extrusion apparatus shown below. The obtained multilayer sheet was pulverized in the same manner as above, and 90 parts by weight of the pulverized material was dry-blended with 10 parts by weight of the modified polyethylene (d-1) to obtain a raw material for the next recovery layer (Reg2). After repeating this operation five times, the screw used for the fifth extrusion of the recovery layer (Reg5) was taken out from the extruder, and the state of adhesion of the resin was visually observed. It was within the removable range. In addition, pelletization was performed at 210 ° C using the raw material of the fifth recovery layer (Reg5), and the state of formation of the toner adhering around the strand one hour later was visually observed. No outbreak was observed.

[0102] Configuration of multilayer extrusion device:

Extruder 1 HDPE Screw diameter: 25mm Temperature: 190 ° C

Extruder 2 For HDPE or Reg Screw diameter: 40mm Temperature: 210 ° C

Extruder 3 For AD Screw diameter: 20mm Temperature: 190 ° C

Extruder 4 For EVOH Screw diameter: 20mm Temperature: 210 ° C

Extruder 5 AD Screw diameter: 20mm Temperature: 190 ° C

Extruder 6 HDPE Screw diameter: 40mm Temperature: 210 ° C

V, the shift screw is also a screw without a kneading part called full flight.

[0103] Comparative Example 1

As a raw material for the recovery layer (Regn, n is an integer of 1 to 5), the same procedure as in Example 1 was carried out except that modified polyethylene (d-1) was not mixed with the pulverized multilayer sheet. A multi-layer sheet containing was prepared. The screw used for the fifth extrusion of the recovery layer (Reg5) was removed from the extruder, and the state of resin adhesion was visually observed. The amount of adhesion was large, and considerable time and labor was required to remove the resin. Cost me. In addition, using the raw material of the fifth recovery layer (Reg5), At 0 ° C., the pelleting was performed. It is presumed that the thermal stability of the carboxylic acid-modified polyolefin deteriorated by increasing the number of times of recovery, and the dispersion of EVOH in the recovery layer deteriorated. That is, it has become clear that the addition of the thermoplastic resin (D) having a boron-containing group greatly improves the thermal stability of the regrind composition.

[0104] Example 2

Produced by Kuraray Co., Ltd. EVOH "Ebaru (R) -F101" (ethylene content 32 mol ^_0/0, saponification degree 99.5%, an intrinsic viscosity 1. ldl / g) (EVOH), Mitsui I匕学Co. anhydride Using the maleic acid-modified polyethylene “Admer (registered trademark) GT6” (AD) and the high-density polyethylene “Lupolen (registered trademark) 4261 AG” (HDPE) manufactured by Bassel, using the multilayer extrusion equipment shown below, HDPEZADZEVOHZADZHDPE = 510/20/30/20

A sheet having a layer structure of Ζ420 / ζπι was prepared. Next, the obtained multilayer sheet was pulverized to an appropriate size so that it could be put into an extruder. 5 parts by weight of the modified polyethylene (d-2: BEAG-modified VLDPE) obtained in Synthesis Example 2 was dry-blended with 95 parts by weight of the pulverized product to obtain a raw material for a recovery layer (Regl). Using this raw material and each of the above resins, a sheet having a layer configuration of HDPEZReglZADZEVOHZADZHDPE = 110Z400 Z20Z30Z20Z420 / Zm was prepared using the same multilayer extrusion apparatus as in Example 1 under the same conditions. The obtained multilayer sheet was pulverized in the same manner as described above, and 95 parts by weight of the pulverized product was dry blended with 5 parts by weight of a modified polyethylene (d-2) to obtain a raw material for the next recovery layer (Reg2). After repeating this operation five times, the appearance and impact strength of the multilayer sheet prepared using Reg5 were evaluated. The appearance of the multilayer sheet was evaluated by visual observation. For the impact strength, a test piece was prepared from the obtained multilayer sheet using an ASTM-D1829 dampening cutter, and the TIS (tensile impact strength) was measured at 40 ° C. in the MD direction at n = 10. After the above operation was repeated 5 times, the fifth recovery layer (Reg 5) was pulverized, and then pelletized at 210 ° C. One hour later, the particles adhering around the strand were removed. The degree of occurrence was visually observed. No occurrence of force was observed.

[0105] Example 3

A test was conducted in the same manner as in Example 2 except that the operation of dry blending 10 parts by weight of modified polyethylene (d-2: BEAG modified VLDPE) with 90 parts by weight of the pulverized material to form a multilayer sheet was repeated. Tests were performed and evaluated. The results are summarized in Table 2.

Example 4

Same as Example 2 except that the procedure of dry blending 5 parts by weight of the modified polyethylene obtained in Synthesis Example 1 (d-1: BEAG-modified HDPE) with 95 parts by weight of the pulverized material to form a multilayer sheet was repeated. A test was performed and evaluated. The results are summarized in Table 2.

[0107] Comparative Example 2

Example 2 was repeated except that the operation of dry-blending 5 parts by weight of maleic anhydride-modified polyethylene “ADMA-1 (registered trademark) GT6J” manufactured by Mitsui-Danigaku Co., Ltd. to 95 parts by weight of the pulverized product to form a multilayer sheet was repeated. The test was performed and evaluated in the same manner, and the results are summarized in Table 2.

[0108] Comparative Example 3

A test was performed and evaluated in the same manner as in Example 2 except that the operation of forming a multilayer sheet was repeated without adding anything to the pulverized material. The results are summarized in Table 2.

[0109] [Table 2]

[0110] As can be seen from Table 2, the regrind containing EVOH (A), carboxylic acid-modified polyolefin (B), and thermoplastic resin (C) was compared with the thermoplastic resin having a boron-containing functional group. In Examples 2 to 4 in which (D) was blended, it can be seen that the thermal stability was improved, the occurrence of burnout during pelletizing was suppressed, and the appearance and impact resistance of the resulting sheet were also excellent. On the other hand, in Comparative Example 2 in which a carboxylic acid-modified polyethylene was blended in place of the thermoplastic resin (D) having a boron-containing functional group, the occurrence of cracks became remarkable, and the resulting multi-layered resin was obtained. The appearance and impact resistance of the sheet were also poor. In Comparative Example 3 in which nothing was added to the regrind, the appearance and impact resistance of the obtained multilayer sheet were further deteriorated. Also, as can be seen from the comparison between Example 2 and Example 4, it is better to use thermoplastic resin (D) with a low density and polyethylene as the base polymer, which is more excellent in impact resistance. Giving a sheet is easy.

[0111] Example 5

Using Reg5 obtained in Example 2, co-extrusion blow molding was performed under the following conditions to prepare a multilayer bottle of HDPEZReg5ZADZEVOHZADZHDPE having a size of 750 ml. Was When the appearance of the obtained multilayer bottle was visually evaluated, the appearance was good. The center of the bottle was sampled, and a test piece was prepared using an ASTM D1829 dumbbell cutter. TIS (tensile impact strength) was measured at 40 ° C in the MD direction at n = 10. ² , indicating good impact resistance.

[0112] Co-extrusion blow molding conditions

Molding machine: 4 types 7-layer direct blow molding machine manufactured by Suzuki Iron Works

HDPE extrusion temperature: 190 ° C

Reg5 extrusion temperature: 190 ° C

AD extrusion temperature: 180 ° C

EVOH extrusion temperature: 205 ° C

Mold temperature: 80 ° C

[0113] Comparative Example 4

Using Reg5 obtained in Comparative Example 3, a multilayer bottle was prepared and evaluated in the same manner as in Example 5. When the appearance of the obtained multilayer bottle was visually evaluated, unevenness of the film surface occurred frequently. Moreover, sampling the flat central portion of the bottle, ASTM- D1829 dumbbell cutlet coater at creating a test piece, -40 ° C, MD direction, n = 10 was measured TIS (tensile impact strength) at 50KjZm ² And the impact resistance was insufficient.

Claims

The scope of the claims

[1] an ethylene content of 5 to 60 mole ^_0/0, 85% or more of ethylene Bulle alcohol copolymer saponification degree polymer (A) layer, a carboxylic acid-modified polyolefin (B) layer, the following solubility parameters (in F edors 11 A multi-layered structure having a thermoplastic resin (C) layer having the formula force calculation) and a resin composition (E) layer;

The above resin composition (E) power Ethylene vinyl alcohol copolymer (A), carboxylic acid-modified polyolefin (B), thermoplastic resin (C) and conversion to boronic acid group in the presence of boronic acid group and water A thermoplastic resin (D) having at least one functional group selected from the group consisting of boron-containing groups, and

It is characterized in that an ethylene butyl alcohol copolymer (A) layer and a thermoplastic resin (C) layer or a resin composition (E) layer are laminated via a carboxylic acid-modified polyolefin (B) layer. Characteristic multilayer structure.

[2] The resin composition (E) power ethylene-butyl alcohol copolymer (A) 1 to 40% by weight, carboxylic acid-modified polyolefin (B) 0.1 to 39.1% by weight, thermoplastic resin ( The multilayer structure according to claim 1, comprising 59.8 to 98.8% by weight of C) and 0.1 to 39.1% by weight of the thermoplastic resin (D).

3. The multilayer structure according to claim 1, wherein the thermoplastic resin (C) is a substantially unmodified polyolefin.

[4] The multilayer structure according to any one of claims 1 to 3, wherein the content of the boron-containing group in the thermoplastic resin (D) is 0.001 to 2 meqZg.

[5] The thermoplastic resin (D) power is a polyolefin having at least one functional group selected from the group consisting of a boron-containing group capable of converting to a boronic acid group in the presence of a boronic acid group and water. The multilayer structure according to any one of claims 1 to 4.

6. The multilayer structure according to claim 5, wherein the thermoplastic resin (D) is polyethylene having a density of 0.85 to 0.94 gZcm ³ .

[7] An extruded product comprising the multilayer structure according to any one of claims 1 to 6.

[8] Claims 1 to 6! A blow-molded article comprising a multilayer structure according to any one of claims.

[9] The thermoformed product according to any one of claims 1 to 6, which has a multilayered structure.

[10] A fuel container having a multilayer structure according to any one of claims 1 to 6.

[11] The regrind obtained from the multilayer structure having the ethylene butyl alcohol copolymer (A) layer, the carboxylic acid-modified polyolefin (B) layer, and the thermoplastic resin (C) layer is further added to the thermoplastic resin ( The method for producing a multilayer structure according to any one of claims 1 to 6, wherein D) is added and melt-kneaded to form the resin composition (E) layer.

[12] In addition to the regrind force ethylene-vinyl alcohol copolymer (A) layer, carboxylic acid-modified polyolefin (B) layer, and thermoplastic resin (C) layer, a resin composition (E) layer is further provided. 12. The method for producing a multilayer structure according to claim 11, which is obtained.

[13] The thermoplastic resin (D) is added in an amount of 0.1 to 30 parts by weight to the total of 100 parts by weight of the regrind and the thermoplastic resin (D) added thereto, and the mixture is melt-kneaded. 13. The method for producing a multilayer structure according to item 12.

[14] The method for producing a multilayer structure according to any one of claims 11 to 13, wherein coextrusion molding or coinjection molding is performed.