WO2004069922A1

WO2004069922A1 - Resin composition and use thereof

Info

Publication number: WO2004069922A1
Application number: PCT/JP2004/001251
Authority: WO
Inventors: Shinta Miyazumi; Keisuke Fujimura
Original assignee: The Nippon Synthetic Chemical Industry Co., Ltd.
Priority date: 2003-02-07
Filing date: 2004-02-06
Publication date: 2004-08-19

Abstract

A resin composition with which the dispersion of thickness in the TD (width) direction can be inhibited at the film formation through inflation, etc. to thereby enable obtaining a shaped item, such as film or sheet, of uniform thickness; and a monolayer or multilayer structure produced from the resin composition. In particular, a resin composition comprising a copolymer of ethylene, vinyl acetate and vinylsilane compound having been saponified (A) and magnesium acetate or a higher fatty acid salt of bivalent metal (B); and a multilayer structure comprising a layer of the resin composition.

Description

Akira Itoda Resin composition and its use Technical field

The present invention relates to a resin composition containing a saponified copolymer of ethylene, biel acetate and a butylsilane compound, and a multilayer structure using the same. More specifically, the present invention relates to a TD (width) direction during film formation such as inflation molding. The present invention relates to a resin composition of the above-mentioned saponified copolymer in which the variation in the thickness of the resin is suppressed, and a multilayer structure having a layer of the composition. Background art

Conventionally, saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) is excellent in transparency, gas barrier properties, fragrance retention, solvent resistance, oil resistance, and the like. It is formed into films and sheets for food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, etc., or containers such as bottles.

In the above-mentioned molding, it is general to extrude EVOH in a molten state from an extruder or other device (die, etc.) with a certain thickness to form a film. However, the unevenness of cooling and the flow of molten resin The thickness of the extruded film or sheet may be uneven due to unevenness or neck-in. In particular, thickness variations are often observed in the TD (width) direction, and these variations cause poor appearance of the formed film or sheet, poor adhesion (lamination) with other films or sheets, and printing on the surface. This results in inconvenience such as failure. Therefore, in order to prevent such variations, the applicant of the present invention added a boron compound, peroxide, polyacid, polyamide compound, copper compound, aluminum compound to EVOH. An EVOH (see JP-A-9-1165483) obtained by reacting at least one compound selected from a nickel compound, a titanium compound, a zinc compound, a tin compound, a vanadium compound, and a chromium compound; (See Japanese Patent Application Laid-Open No. 2000-351811) was proposed.

However, with the technology disclosed in Japanese Patent Application Laid-Open No. 9-165483, it is possible to obtain a film having excellent transparency, but it is not possible to suppress variations in the film thickness in the TD direction during film formation by an inflation molding machine. Difficult and gel-rich films are easier to make. Although the technique disclosed in Japanese Patent Application Laid-Open No. 2000-351811 can improve the swaying and meandering of the film at the time of high-speed film formation, the use of a die having a long flow path at the time of inflation molding, the outermost layer or the like. In the case of a laminate having an EVOH layer as the innermost layer, the film thickness in the TD direction may not be stable. Therefore, there is a need for a resin composition that suppresses variations in the thickness in the TD direction during film formation. Disclosure of the invention

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that copolymers of ethylene, vinyl acetate and vinyl silane compounds (A), magnesium acetate or higher fatty acid salts of divalent metals The present inventors have found that a resin composition containing (B) meets the above object, and have completed the present invention.

That is, the present invention is a resin composition containing a saponified copolymer of ethylene, vinyl acetate and a vinylsilane-based compound (A), a higher fatty acid S-borate salt of magnesium acetate or a divalent metal (B) (B).

The content of silicon in the saponified copolymer (A) is preferably from 0.001 to 0.1% by weight. The content of the higher fatty acid salt of magnesium acetate or divalent metal (B) is 0.001 to 0.05 part by weight in terms of metal with respect to 100 parts by weight of the copolymer saponified product (A). Is preferred.

It is preferable that the ethylene content in the copolymer (A) is 5 to 60 mol% and the saponification degree of the biel acetate component is 90 mol% or more.

Further, it preferably contains a boron compound (C).

The content of the boron compound (C) is preferably 0.01 to 1 part by weight in terms of boron based on 100 parts by weight of the saponified copolymer (A).

Further, the present invention is a multilayer structure including at least one layer composed of the resin composition.

It is preferable that the layer composed of the resin composition is composed of a multilayer film arranged on the outermost layer, and another film bonded to the multilayer film.

The multilayer structure is preferably manufactured by an inflation molding method. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

The saponified copolymer (A) used in the resin composition of the present invention is obtained by saponifying a copolymer of ethylene, vinyl acetate and a vinylsilane compound. Examples of vinylsilane compounds include vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, pinyltriethoxyquin, vinylisobutyldimethoxysilane, vinylethyldimethoxysilane, vinylmethoxydibutoxysilane, vinyldimethoxybutoxysilane, and vinyltrimethoxysilane. Butoxysilane, vinylmethoxydihexyloxysilane, vinyldimethoxyhexyloxysilane, vinyltrihexyloxysilane, pinyl Methoxydioctyloxysilane, vinyldimethoxyoctyloxysilane, Biertrioctyloxysilane, vinylmethyst, xidilauratexylsilane, vinyldimethoxylaurixylsilane, vinylmethoxydiole xylane, vinyldimethoxyolate xylane, etc. it can. Among them, vinyltrimethoxysilane and vinyltriethoxysilane are preferably used.

To obtain the copolymer, vinyl acetate and the above-mentioned vinylsilane-based compound are dissolved in a solvent such as methanol, and the solution is pressed under ethylene (about 30 to 6 O kg Zcm ² ) under 2,2′- The target copolymer can be obtained by performing a copolymerization reaction in the presence of a polymerization initiator such as azobisisobutyronitrile (AIBN).

The ethylene content in the copolymer is preferably from 5 to 60 mol%, more preferably from 25 to 58 mol%, even more preferably from 25 to 55 mol%. If the ethylene content is less than 5 mol%, the gas barrier properties and melt moldability of the finally obtained copolymer saponified product (A) at high humidity are reduced, and conversely, it exceeds 60 mol%. However, it is not preferable because sufficient gas barrier properties cannot be obtained.

Further, the content of silicon derived from the Biersilane group in the copolymer is preferably from 0.01 to 0.1% by weight, more preferably from 0.05 to 0.05% by weight. , 0.05 to 0.03% by weight. If the content is less than 0.001% by weight, the effect of the present invention may not be sufficiently obtained. On the other hand, if the content exceeds 0.1% by weight, a gel may be formed on a molded film. Not preferred.

In the present invention, a copolymerizable ethylenically unsaturated monomer may be further copolymerized as long as the effects of the present invention are not impaired. Examples of such monomers include olefins such as propylene, 1-butene, and isobutene, acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid, and (anhydrous) maleic. Acid, (anhydride) unsaturated acids such as itaconic acid or salts thereof or mono- or dialkyl esters having 1 to 18 carbon atoms, acrylamide, N-alkylacrylamide having 1 to 18 carbon atoms, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or its salt, acrylamide such as acrylamidopropyldimethylamine or its acid salt or its quaternary salt, methacrylamide, N-alkylmethacrylamide having 1 to 18 carbon atoms, N, N— Methacrylamides such as dimethyl methacrylamide, 2-methylacrylamide propanesulfonic acid or its salt, methacrylamidopropyldimethylamine or its acid salt or its quaternary salt, N-vinylpyrrolidone, N_pinylformamide, N_vinylase N-vinyl such as amide Amides, vinyl cyanides such as acryl nitrile, methacryl nitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ether, alkoxyalkyl vinyl ether, vinyl chloride, vinylidene chloride, vinyl fluoride, Vinyl halides such as vinylidene fluoride and vinyl bromide; vinylsilanes such as trimethoxyvinylsilane; aryl acetate, aryl chloride, acryl alcohol, dimethylaryl alcohol, trimethyl- (3-acrylamide-13-dimethylpropyl) ) -Ammonium chloride, acrylamide-2-methylpropanesulfonic acid and the like. Further, as long as the gist of the present invention is not impaired, it is possible to post-modify the copolymer genated product such as urethane, acetal, and cyanoethyl.

The copolymer is then saponified to obtain the saponified copolymer (A) used in the present invention. For the saponification, a known method can be adopted. For example, the copolymer is saponified in a methanol solvent with sodium hydroxide, hydroxylated water, sodium methylate, potassium hydroxide or the like, and then neutralized with an acid such as acetic acid. The copolymer saponified product (A) You get it.

The saponification degree of the vinyl acetate component of the obtained saponified copolymer (A) is preferably at least 90 mol%, more preferably at least 95 mol%, even more preferably at least 99 mol%. If the degree of saponification of such a vinyl acetate component is less than 90 mol%, the gas barrier properties, thermal stability, moisture resistance, etc. are undesirably reduced.

Further, the saponified copolymer (A) preferably has a melt flow rate (MFR) (210 ° C., load 2160 g) of 0.5 to 100 g / 10 min, more preferably 1 to 50 gZl0. Min, more preferably 3 to 35 gZlO min. If the melt flow rate is less than 0.5 gZl O minute, the inside of the extruder may be in a high torque state during molding and extrusion may be difficult. The thickness accuracy of the sheet is undesirably reduced.

Further, as the saponified copolymer EVOH (A), it is also possible to use two or more different saponified copolymers. In this case, the ethylene content is 5 mol% or more (furthermore, 5 mol% or more). ~ 25 mol%, especially 8-20 mol%) and / or differ in the degree of gation by more than 1 mol% (further 1-15 mol%, especially 2-10 mol%), and Z or MFR The ratio is preferably 2 or more (more preferably 3 to 20, especially 4 to 15).

The resin composition of the present invention contains the above-mentioned copolymer (A) and magnesium acetate or a higher fatty acid salt of a divalent metal (B). Examples of the higher fatty acid salt of a divalent metal include fatty acid salts having 8 or more carbon atoms. Specifically, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptydecyl acid, Alkaline earth metal salts such as magnesium salt, calcium salt and barium salt of higher fatty acids such as stearic acid, nonadecanoic acid, oleic acid, carboxylic acid, behenic acid and linoleic acid, and zinc metal salts be able to. Above all, stearic acid, oleic acid, Alkaline earth metal salts of lauric acid (magnesium salts, calcium salts) are preferably used.

The resin composition of the present invention comprises a saponified copolymer (A) and a metal salt (B), and the content thereof is not particularly limited. However, the metal salt (B) is copolymerized in terms of metal. 0.001 to 0.05 part by weight (further 0.001 to 0.03 parts by weight, particularly 0.001 to 1.0 part by weight) based on 100 parts by weight of the combined saponified compound (A) 0.02 parts by weight). If the content is less than 0.001 part by weight, it is difficult to sufficiently obtain the effects of the present invention, and if it exceeds 0.05 part by weight, the resulting film or sheet may have poor appearance. Is not preferred.

In order to obtain the resin composition of the present invention, a copolymer saponified compound (A) and a metal salt

(B) should be blended, but specifically,

A) A method of externally adding magnesium acetate or a fatty acid metal salt (B) to a saponified copolymer (A) powder or pellets,

B) a method in which saponified copolymer (A) is melt-mixed with magnesium acetate or fatty acid metal salt (B),

Ii) A method in which a fatty acid metal salt (B) is mixed with a resin composition (A) solution (water Z alcohol solution, etc.) and then extruded into a coagulating liquid into a strand to form a pellet.

And the like. Preferably, the method a) is employed.

In the present invention, it is also preferable to further include a boron compound (C) in such a resin composition since the effects of the present invention can be more remarkably obtained. The boron compound (C) is boric acid or a metal salt thereof, such as calcium borate, cobalt borate, zinc borate (zinc tetraborate, zinc metaborate, etc.), aluminum / potassium borate, ammonium borate Ammonia (ammonium metaborate, ammonium tetraborate, ammonium pentaborate Cadmium, ammonium octaborate, etc.), cadmium borate (cadmium orthoborate, cadmium tetraborate, etc.), potassium borate (potassium metaborate, potassium tetraborate, potassium pentaborate, potassium hexaborate, potassium hexaborate, Potassium borohydride, silver borate (silver metaborate, silver tetraborate, etc.), copper borate (cupric borate, copper metaborate, copper tetraborate, etc.), sodium borate (metaborate) Sodium silicate, sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate, sodium octaborate, etc., lead borate (lead metaborate, lead hexaborate, etc.), nickel borate (orthoborate) Nickel sulphate, nickel diborate, nickel tetraborate, nickel octaborate, etc.), barium borate (ortho borate , Barium metaborate, barium diborate, barium tetraborate, etc.), bismuth borate, magnesium borate (magnesium orthoborate, magnesium diborate, magnesium metaborate, trimagnesium tetraborate, tetraborate) Manganese borate (manganese borate, manganese metaborate, manganese tetraborate, etc.), lithium borate (lithium metaborate, lithium tetraborate, lithium pentaborate, etc.) Other examples include borate minerals such as borax, rikonite, inoite, goethite, syanite, and syberite, and preferably borax, boric acid, sodium borate (sodium metaborate, Sodium diborate, sodium tetraborate, sodium pentaborate, sodium hexaborate , Sodium octaborate, etc.).

The content of the boron compound (C) is not particularly limited, but is preferably 0.01 to 1.0 part by weight in terms of boron with respect to 100 parts by weight of the saponified copolymer (A). 0.001 to 0.5 part by weight is more preferable, and 0.01 to 0.2 part by weight is further preferable. If the content is less than 0.001 part by weight, it is difficult to obtain the content effect, and if the content exceeds 1.0 part by weight, the appearance of the resulting film or sheet tends to deteriorate. Preferred Absent.

The method of adding the boron compound (C) to the resin composition is not particularly limited. A method of adding the boron compound (C) to the resin composition containing the saponified copolymer (A) and the metal salt (B). Although it is also possible to employ, it is preferable to incorporate the boron compound (C) in the saponified copolymer (A) in advance in consideration of uniformly dispersing the boron compound (C). Particularly preferred methods include:

1) The porous precipitate of the saponified copolymer having a water content of 20 to 80% by weight was prepared by using the water content of the boron compound in the aqueous boron compound solution and the aqueous solution of the boron compound in the saponified copolymer compound. After contacting with a boron compound aqueous solution adjusted to be 0.001 to 1.0 parts by weight with respect to 100 parts by weight of the total amount of water contained therein, Drying by combining fluidized drying and standing drying,

2) a method in which a saponified copolymer is brought into contact with an aqueous solution of a boron compound to contain the boron compound, and then dried to a water content of 0.001 to 2% by weight and then brought into contact with water;

3) Copolymer saponified product obtained by contacting a pellet with an aqueous solution of a boron compound to contain a boron compound, and then drying to a water content of 0.001 to 10% by weight. A method in which the pellets are melt-kneaded to make pellets again,

4) After the boron compound is contained in a homogeneous solution of the saponified copolymer (water / alcohol solution, etc.), it is extruded into strands in the coagulation solution, and the resulting strands are cut into pellets. Examples of the method include a drying treatment.

Thus, the resin composition of the present invention containing the saponified copolymer (A) and the metal salt (B), or the saponified copolymer (A), the metal salt (B) and the boron compound (C) is obtained. Although it can be obtained, in the present invention, a saturated aliphatic amine is added to the resin composition as long as the object of the present invention is not impaired. (For example, stearic acid amide), unsaturated fatty acid amide (for example, oleic acid amide), bisfatty acid amide (for example, ethylene bisstearic acid amide), low molecular weight polyolefin (for example, molecular weight 500 to 100,0) Low molecular weight polyethylene of about 0, or low molecular weight polypropylene, etc.

), Organic acids (eg, acetic acid, propionic acid, stearic acid, etc.), inorganic acids (eg, boric acid, phosphoric acid, etc.), inorganic salts (eg, hexahydrotalcite, etc.), plasticizers (eg, ethylene glycol, glycerin, It does not contain aliphatic polyhydric alcohols such as hexanediol, etc., oxygen absorbers (for example, reduced iron powder, potassium sulfite, ascorbic acid, hydridone, gallic acid, etc.), heat stabilizers, light stabilizers, and amide groups. Antioxidants, UV absorbers, coloring agents, antistatic agents, surfactants, antibacterial agents, antiblocking agents, slip agents, fillers (such as inorganic fillers), other resins (such as polyolefin, polyester, etc.) ) May be blended.

The resin composition of the present invention is useful for various packaging materials, and can be directly used for melt molding and used for such applications.However, workability during melt molding and discharge stability of an extruder are also possible. In consideration of the above, it is preferable that the mixture is kneaded once in a molten state, then cooled and solidified to form a pellet or the like. As such means, for example, a known kneading apparatus such as a kneader-ruder, an extruder, a mixing roll, a Banbury mixer, and a blast mill can be used, but usually, a single-screw or twin-screw extruder is used. Is industrially preferred. It is also preferable to provide a vent suction device, a gear pump device, a screen device, and the like as necessary. In particular, the extruder is provided with one or more vent holes to remove moisture and by-products (such as pyrolyzed low-molecular-weight products) to prevent suction under reduced pressure and to prevent oxygen from entering the extruder. By continuously supplying an inert gas such as nitrogen into the hopper, a high-quality resin composition with reduced thermal coloring and thermal deterioration can be obtained. The resin composition of the present invention is formed into films, sheets, containers, fibers, rods, pipes, and other various molded products by melt molding, and is also used to form these crushed products (for example, when reusing recovered products). It can be again subjected to melt molding. As the melt molding method, an extrusion molding method (τ-die extrusion, inflation extrusion, professional molding, melt spinning, profile extrusion, etc.) and an injection molding method are mainly employed, and a melting temperature of 150 to 30 is used. It is often selected from the range of 0 ° C.

In particular, the resin composition of the present invention can remarkably exert its function and effect in the inflation molding method. Such a molding method will be described. The inflation molding method refers to a method in which a resin or resin composition melted by an extruder is guided into a cylindrical die (spider die, spiral mandrel die, etc.), and is placed inside a cylindrical film extruded from the die. This is a method in which air is blown to expand, cooled by an air ring or other device, and the resulting film is wound up. In applying the resin composition of the present invention to such a method, inflation molding can be performed using a conventionally known air-cooled multilayer inflation film forming apparatus. Conventionally known molding conditions can be adopted as the molding conditions.For example, the blow-up ratio is 0.75 to 1.0, the take-off speed is 15 to 30 m / min, and the film folding width is The melting temperature of the resin composition of the present invention may be in the range of about 150 to 250 ° C (further, about 180 to 230 ° C). You can choose from. Such a molded article can of course be used as a single layer for various applications, but is also useful as a laminate (multilayer structure), and in particular, a thermoplastic resin layer is formed on at least one side of a layer made of the resin composition. These are preferably used as a laminate obtained by laminating, and a laminate suitable for practical use having water resistance, mechanical properties, heat sealing properties and the like is obtained.

Hereinafter, such a laminate will be described.

In producing the laminate, one side or both sides of the resin composition of the present invention are used. Another substrate (such as a thermoplastic resin) is laminated on the surface. The laminating method is, for example, melt extrusion of the other substrate into a molded film or a molded sheet of the resin composition of the present invention. Laminating method, conversely, melt extrusion lamination of the resin composition on another base material, co-extrusion of the resin composition with another base material, molded film or molded film of the resin composition And a method of dry laminating the substrate with another substrate using an adhesive such as an organic titanium compound, an isocyanate compound, a polyester compound, or a polyurethane compound. The melt molding temperature during the above melt extrusion is often selected from the range of 150 to 300 ° C.

As such another substrate, a thermoplastic resin is useful. Specifically, linear low-density polyethylene, low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-vinyl acetate Polymers, ionomers, ethylene-propylene (block or random) copolymers, ethylene-acrylic acid copolymers, ethylene-acrylic acid ester copolymers, ethylene-methacrylic acid copolymers, ethylene-methacrylic acid ester copolymers Copolymer, Polypropylene, Propylene-α-olefin (α-olefin with 4 to 20 carbon atoms) Copolymer, Polybutene, Polypentene, Polymethylene

Polyolefin resins, polyester resins, polyamide resins (copolymers) such as homo- or copolymers of olefins, or those obtained by graft-modifying homo- or copolymers of these olefins with unsaturated carboxylic acids or their esters. (Including polyamide), polyvinyl chloride, polyvinylidene chloride, acrylic resin, polystyrene resin, vinyl ester resin, polyester elastomer

Polyethylene, chlorinated polypropylene, aromatic or aliphatic polyketones, polyalcohols obtained by reducing them, and other ΕVOH are also examples of the properties of the laminate (particularly strength and appearance). Such as practical In terms of properties, polypropylene, ethylene-propylene (block or random) copolymer, polyamide, polyethylene, ethylene-vinyl acetate copolymer, polystyrene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN) Preferably, polypropylene, ethylene-propylene (block or random) copolymer, or polyethylene, which is excellent in stretchability, transparency and flexibility, is used. .

Further, when a base such as a film or sheet of the resin composition of the present invention is extrusion-coated with another base or a film or sheet of another base is laminated with an adhesive, such base is used as the base. Any substrate other than the above-mentioned thermoplastic resin (paper, metal foil, uniaxial or biaxially stretched plastic film or sheet and its inorganic deposits, woven fabric, nonwoven fabric, metallic cotton, woody, etc.) can be used It is.

The layer structure of the laminate, the layer of the resin composition of the present invention is a (al, a2,

), Other substrates, for example, if the thermoplastic resin layer is b (bl, b2, · · ·), if it is a film, sheet, or bottle, not only the two-layer structure of a Zb but also b / a / b, aZbZa, a 1 / a 2Zb, aZb lZb 2, b 2/1 / a / 1 / b 2, b2 / / bl / a / bl / a / bl / / b 2 etc. can be any combination In addition, when a regrind layer composed of a mixture of at least a resin composition and a thermoplastic resin is defined as R, b / R / a, b / R / a / b, b / R / a / R / b, It is also possible to use b / a / R / a / b, b / R / a / R / a ZRZb, etc. In the filament form, a and b are bimetallic, core (a) —sheath (b) type Any combination such as a core (b) -sheath (a) type or an eccentric core-sheath type is possible.

In the present invention, in the above-mentioned laminated structure, a laminated structure in which the layer of the resin composition of the present invention is the outermost layer is particularly preferable, and more specifically, the layer Z of the resin composition of the present invention is an adhesive resin. Layer Z Polyolefin resin (preferably poly Ethylene) layer, layer of the resin composition of the present invention / polyamide-based resin layer, and Z polyolefin-based resin (preferably polyethylene) layer. In such a laminated structure, advantages such as better film appearance and excellent uniformity of film thickness can be obtained.

In the above-described various layer configurations, an adhesive resin layer can be provided between each layer as needed, and various adhesive resins can be used as the adhesive resin. It is preferable in that an excellent laminate can be obtained. Although it depends on the type of the resin b and cannot be stated unconditionally, the unsaturated carboxylic acid or its anhydride can be converted into an olefin polymer (the above-mentioned olefin alone or copolymer). Examples include a modified olefin polymer containing a carboxyl group obtained by chemically bonding by an addition reaction, a graft reaction, or the like.Specifically, maleic anhydride graft-modified polyethylene, maleic anhydride graft-modified Polypropylene, maleic anhydride graft-modified ethylene-propylene (block or random) copolymer, maleic anhydride Preferred examples include one or a mixture of two or more selected from a graft-modified ethylene-ethyl acrylate copolymer, a maleic anhydride-graft-modified ethylene-vinyl acetate copolymer, and the like. At this time, the amount of the unsaturated carboxylic acid or the anhydride thereof contained in the thermoplastic resin is preferably 0.001 to 3% by weight, more preferably 0.01 to 1% by weight, and particularly preferably. 0.3 to 0.5% by weight. If the amount of modification in the modified product is small, the adhesiveness may be insufficient, while if it is large, a crosslinking reaction may occur and moldability may deteriorate, which is not preferable. In addition, these adhesive resins can be blended with the resin composition of the present invention, other rubber / elastomer components such as EV プ H, polyisobutylene, and ethylene-propylene rubber, as well as the resin in layer b. It is. In particular, by blending a polyolefin resin that is different from the polyolefin resin that is the base of the adhesive resin, the adhesiveness is improved. There is useful.

The thickness of each layer of the laminated body cannot be specified unconditionally depending on the layer constitution, the type of b, the use and the form of the container, the required physical properties, etc., but usually the layer a is 5 to 500 m (and 0 ~ 200 ^ m), b layer is 10 ~ 500m (or even 30 ~ 100 ^ m), adhesive resin layer is 5 ~ 400m (or even 10m) ~: L is selected from the range of about 50 m). If the thickness of the layer a is less than 5 m, the gas barrier properties are insufficient and the thickness control becomes unstable. On the other hand, if it exceeds 500 x m, the impact resistance and the like are poor, and it is not economical and is not preferred. If the b layer is less than 100 m, the rigidity is insufficient, and if it exceeds 500 m; When the thickness of the adhesive resin layer is less than 5 m, the interlayer adhesiveness is insufficient and the thickness control becomes unstable. On the other hand, when the thickness exceeds 400 zm, the weight increases, which is not economical and not preferable.

The laminate is used as it is in various shapes. However, in order to further improve the physical properties of the laminate and to form a desired container shape, it is preferable to perform a heat-extending treatment. Here, the heat-stretching process refers to a film, sheet, or parison-like laminate that has been uniformly heated by means of chucks, plugs, true aerodynamics, pneumatics, blows, etc., cups, trays, tubes, bottles, films This means that the film may be uniaxially stretched or biaxially stretched. Stretching at the highest possible magnification provides better physical properties. A stretch-formed product excellent in gas barrier properties, free from cracks, stretching unevenness, uneven thickness, and delamination, is obtained. As the stretching method, any of a roll stretching method, a tensile stretching method, a tubular stretching method, a stretch blow method, a vacuum forming, a press forming, a vacuum press forming, etc., which has a high draw ratio can be employed. In the case of biaxial stretching, any of a simultaneous biaxial stretching method and a sequential biaxial stretching method can be employed. The stretching temperature is selected from the range of 60 to 170 ° C, preferably about 80 to 160 ° C. After completion of the stretching, it is also preferable to perform heat setting. The heat setting can be performed by a well-known means, and the stretched film is heat-treated at 80 to 170 ° C, preferably 100 to 160 ° C for about 2 to 600 seconds while maintaining the stretched state. I do.

In addition, when used for heat shrink packaging of raw meat, processed meat, cheese, etc., it is used as a product film without heat setting after stretching, and after storing the raw meat, processed meat, cheese, etc. in the film, 50 to 130 ° (preferably, 70 to 120 ° C, heat treatment is performed for about 2 to 300 seconds, and the film is heat-shrinked to perform tight packaging.

The shape of the thus obtained laminate may be any shape, and examples thereof include a film, a sheet, a tape, a cup, a tray, a tube, a pottle, a pipe, a filament, and an extrudate of a modified cross section. In addition, the obtained laminate can be heat-treated, cooled, rolled, printed, dry-laminated, solution or melt-coated, bag-formed, deep drawn, boxed, tubed, or split as required. And so on.

Containers made of cups, trays, tubes, bottles, bottles, bags, bags, etc., and bags and lids made of stretched films obtained as described above, as well as general foods, seasonings such as mayonnaise and dressings, Fermented foods such as miso, oil and fat foods such as salad oil, beverages, cosmetics, pharmaceuticals, detergents, cosmetics, industrial chemicals, agricultural chemicals, fuels, and other containers. This is useful for packaging of foods and pharmaceuticals that make the contents look beautiful.

Hereinafter, the present invention will be described specifically with reference to Examples.

In the examples, “parts” and “%” mean weight standards unless otherwise specified.

Measurement of the content of boron compound in the saponified copolymer (A) and the resin composition The determination was carried out by melting the saponified copolymer (A) and the resin composition with alkali and quantifying boron by ICP emission spectroscopy. For the measurement of the alkali (earth) metal content, the copolymer saponified compound (A) and the resin composition were ashed, dissolved in an aqueous hydrochloric acid solution, and analyzed by atomic absorption spectrometry. Was determined.

[Production of saponified copolymer (A)]

Vinyl acetate and biertrimethoxysilane are dissolved in a methanol solvent and polymerized at a reaction temperature of 60 ° C using 2,2'-azobisisobutyronitrile (AIBN) as an initiator under ethylene pressure (55 kg / cm ² ). The reaction was carried out until the ratio reached 50% to obtain a silane-containing copolymer.

Sodium hydroxide was added to the obtained copolymer in an amount equivalent to 0.02% based on the vinyl acetate component, and a saponification reaction was carried out to obtain an ethylene content of 44 mol% and a saponification degree of the vinyl acetate component. 99.5 mol%, vinylsilane modified amount 0.04 mol% (silicon content 0.03%), MFR 3.2 gZlO content (210 ° C, load 2160 g) copolymer saponified product (A ).

Example 1

100 parts of the saponified copolymer (A), 0.01 part of magnesium acetate (B) (0.002 part in terms of magnesium) and 0.01 part of boric acid (C) (0.0015 part in terms of boron) And were melt-kneaded in a twin-screw extruder under the following conditions to obtain a resin composition (pellet) of the present invention.

[Melting pelletization conditions by twin screw extruder]

Screw inner diameter 30mm (L / D = 30)

Screw shape Compression part has 100 mm reading disk

Screen mesh 90 / 90me sh

Screw rotation speed 150 rpm Vent holes Perform vacuum suction

Supply and replace nitrogen gas in hopper

Extrusion temperature C1: 120 ° C

C 2: 170 ° C

C3: 210 ° C

C4: 220 ° C

C5: 220 ° C

AD: 210 ° C

D: 210 ° C

The obtained resin composition (pellet) was charged into an inflation molding machine, and inflation film formation was performed under the following conditions.

[Inflation film forming conditions]

Die diameter 150mm

Pickup speed 15m / min

Layer composition [Outside] E V 0 HZ Adhesive resin Z LDPE = 10 m / 10 m / 30 [Inside]]

Film fold width 200mm

The thickness of the obtained film in the TD (width) direction was measured, and the average thickness and the difference between the maximum thickness and the minimum thickness were determined. The measurement was performed at intervals of about lcm in the TD direction and over about lm in the MD (longitudinal) direction.

Example 2

In Example 1, except that magnesium acetate (B) was changed to 0.005 part (0.001 part in terms of magnesium) and boric acid (C) to 0.02 part (0.003 part in terms of boron). In the same manner, a resin composition was obtained in the same manner, and evaluation was similarly performed.

Example 3 A resin composition was obtained in the same manner as in Example 1, except that magnesium stearate (B) was used in an amount of 0.025 part (0.001 part in terms of magnesium) in place of magnesium acetate (B). An evaluation was performed.

Example 4

A resin composition was obtained in the same manner as in Example 1 except that magnesium stearate (B) was replaced by 0.02 parts of zinc stearate (B) (0.002 parts in terms of zinc). Was evaluated.

Example 5

A resin composition was obtained in the same manner as in Example 1, except that magnesium acetate (B) was replaced by 0.02 parts of stearic acid (R) (0.0013 parts in terms of calcium). An evaluation was performed.

Example 6

A resin composition was obtained in the same manner as in Example 1 except that potassium borate (C) (0.08 part (0.003 part in terms of boron)) was used instead of boric acid (C). Was done.

Example 7

A resin composition was obtained in the same manner as in Example 1 except that boric acid (C) was not contained, and was similarly evaluated.

Comparative Example 1

In Example 1, inflation molding was performed using only the saponified copolymer (A), and the same evaluation was performed.

Table 1 shows the evaluation results of the examples and the comparative examples. table 1

Unit: rn. Industrial applicability

The resin composition of the present invention can suppress thickness variation in the TD (width) direction at the time of film formation such as inflation molding, and can obtain a molded product such as a film or sheet having a uniform thickness. The multilayer structure including the formed layer is useful for packaging applications such as foods and pharmaceuticals.

Claims

Scope of Word

1. A resin composition containing a saponified copolymer of ethylene, vinyl acetate and a vinylsilane compound (A), magnesium acetate or a higher fatty acid salt of a divalent metal (B).

2. The resin composition according to claim 1, wherein the content of silicon in the saponified copolymer (A) is from 0.001 to 0.1% by weight.

3. The content of the higher fatty acid salt of magnesium acetate or divalent metal (B) is 0.001 to 0 in terms of metal, based on 100 parts by weight of the saponified copolymer (A).

3. The resin composition according to claim 1 or 2, which is 0.5 parts by weight.

4. Claims 1 and 2 wherein the ethylene content in the saponified copolymer (A) is 5 to 60 mol% and the saponification degree of the vinyl acetate component is 90 mol% or more. Item 4. The resin composition according to item 3 or 3.

5. The resin composition according to claim 1, further comprising a boron compound (C).

6. The method according to claim 5, wherein the content of the boron compound (C) is 0.01 to 1 part by weight in terms of boron based on 100 parts by weight of the saponified copolymer (A). Resin composition.

7. A multilayer structure including at least one layer made of the resin composition according to claim 1, 2, 3, 4, 5, or 6.

8. The multilayer structure according to claim 7, wherein the multilayer structure comprises a multilayer film in which a layer made of a resin composition is disposed as an outermost layer, and another film bonded to the multilayer film.

9. The multilayer structure according to claim 7, wherein the multilayer structure is manufactured by an inflation molding method.