KR100216933B1 - Manufacture of multilayer structure - Google Patents

Abstract

The present invention does not contain bubbles such as voids even when extruded at a high temperature, and can be processed at high speed and has a good adhesion between the ethylene-vinyl ester copolymer saponification and the adhesive resin, and the multilayer structure according to the coextrusion coating method, in particular a multilayer film. It relates to a manufacturing method of.

Description

Manufacturing method of multilayer structure

The present invention does not contain bubbles such as voids even by extrusion at high temperature, and can be processed at high speed and has a good adhesion between the ethylene-vinyl ester copolymer saponification and the adhesive resin, and a multilayer structure, in particular a multilayer film. It relates to a manufacturing method of.

Conventionally, a biaxially stretched polypropylene film (hereinafter abbreviated as OPP), a biaxially stretched polyamide film (hereinafter abbreviated as OPA) or a biaxially stretched polyethylene terephthalate film (hereinafter, Substrate films, such as PET), are laminated with polyolefin films and used as packaging materials for various applications including foods and drugs for imparting heat sealability. However, since these films have poor gas barrier properties, the oxygen penetrating into the package from the outside may cause mold to evaporate, the volatilize or retain the oxidation part or taste, and the retention of the content is easy. It is worse, and the improvement of gas barrier property is desired.

As a method of improving gas barrier properties, a solution of vinylidene chloride-methyl methacrylate latex or vinylidene chloride-acrylonitrile copolymer is coated on various films or referred to as PVDC coating films and sold by various companies. It is possible by laminating a film of ethylene-vinyl ester copolymer saponified (hereinafter abbreviated as EVOH), a film of polyvinyl alcohol (hereinafter abbreviated as PVA), and the aforementioned various films. However, the PVDC coating film has a yellowish tinge as it is, and also has the disadvantage of being more yellowed by ultraviolet rays. In addition, PVDC coating films have significant drawbacks that greatly reduce the flex resistance and generate pinholes during transportation and impair gas barrier properties.

On the other hand, products laminated with films of OPP, EVOH or PVA are colorless and transparent, and do not have to be changed in ultraviolet light, but they have the disadvantages that they are inferior in flex resistance, easily peel off when boiling at high temperatures, and also increase in manufacturing cost. .

Japanese Laid-Open Patent Publication No. 51-18775 discloses a method for producing a laminate film, wherein the base film is composed of two or more layers, of which one layer is press-bonded with a thin film melt of EVOH. It is. However, in the above invention, the use of inferior thermal stability due to impurities and other causes of the EVOH used in the present invention must be particularly careful because foaming, fish eye, etc. are generated, and it has a significant effect on the air permeability. And `` The heat resistance is poor, so the melting temperature is 250 Must be made below. However, the publication does not describe prescriptions that can be extruded at a higher temperature, and also extrudes at a higher temperature to improve the ductility of EVOH, and to improve high-speed processing, to improve the adhesion between EVOH and the adhesive resin, and to improve the EVOH. It is not described that the thinning of the layer and the reduction of unmelted EVOH can improve the surface of other membranes.

Japanese Patent Application Laid-Open No. 2-37298 has 10 to 100 weight of EVOH. 30 weight of resin and polyethylene-based resin to contain more than The resin containing the above-mentioned resin is extruded and laminated | stacked so that resin containing this polyethylene-type resin may be laminated | stacked on one surface, and the extruded laminated body is produced, and the polyethylene in which at least its surface part is melt | dissolved immediately after extrusion laminated | stacked Ozone treatment was performed by spraying a gas containing ozone on the surface of the resin layer containing the resin-based resin, and then the separately prepared base sheet, which was subjected to the undercoat treatment on the extruded laminate and the surface described above, was used as the former ozone treatment surface. And a method for producing a laminate characterized by laminating, pressing and cooling so that the latter underside treated surfaces face each other. However, the publication discloses that the EVOH decomposes when heated at high temperatures. It is described that it is necessary to process below. In addition, this publication does not describe prescriptions that can be extruded at higher temperatures and other effects of extruding at higher temperatures.

Japanese Patent Laid-Open No. 3-75120 coextrudes a laminated film upper body coral barrier resin and an adhesive resin composed of a polyester film and an adhesive resin layer, and the adhesive resin is used as the adhesive number of the laminated film. A method for producing a laminate, which is superimposed on a layer and co-extruded, is described. However, the publication also stated that in the case of EVOH, 180 to 240 It is preferable to carry out at a temperature within the range of ". In addition, European Patent Publication No. 504808 describes co-extrusion of an adhesive ethylene polymer having a density of 0.9 / cm 3 or less with EVOH on a base film to obtain a multilayer film having excellent bend resistance and interlayer adhesion. The publication does not describe a treatment method which can be extruded by high temperature and high speed.

Japanese Patent Application Laid-Open No. 64-66262 describes obtaining an EVOH composition with low occurrence of gels and boiling, containing acetyl groups, alkali metal ions and alkaline earth metal ions, but with EVOH and adhesion to the substrate. It is not described to coat the resin by coextrusion.

As described above, the coextrusion lamination of EVOH and adhesive resin is problematic due to the limitation of the extrusion temperature of EVOH and the high temperature is high, and the coextrusion lamination product which does not contain air bubbles or the like even when extruded at high temperature is adhesive with EVOH. It is desired that the adhesive force with the resin be good.

However, the present invention has been devised to solve the above-mentioned drawbacks of the prior art, and does not contain bubbles such as voids even at high temperatures, and can be processed at high speed and has good adhesion between EVOH and adhesive resin. It is an object to obtain an extrusion coated multilayer structure, in particular a multilayer film.

The above-mentioned object is P value [inner diameter is 2 And the length is 1 Nozzle with inner diameter of 9.5 Melt indexer with phosphor cylinder 300 Heating, and 5 g of sample resin (EVOH) were put into the cylinder, and immediately under a load of 2.16 kg, 1 g of sample resin was discharged from the nozzle, the load was removed, the nozzle was sealed, and then a 480 g load was applied to the piston. This 5 Co-extrusion of EVOH (A) and adhesive polyolefin resin (B) (hereinafter abbreviated as APO) having a pyrolysis behavior, which is a time to rise, within 45 seconds to 15 minutes]. By coating.

In the following, the present invention is explained in more detail. In the present invention, EVOH (A) is polymerized ethylene and vinyl ester by a known method using a polymerization initiator such as benzoyl peroxide and azobisisobutyronitrile under pressure in a solvent such as methanol, t-butanol or dimethyl sulfoxide. Next, it is a polymer obtained by saponification with an acid or alkali catalyst. Examples of the vinyl esters include aliphatic vinyl esters such as vinyl acetate ester, vinyl propionate, vinyl basatate, and pivalic acid vinyl esters, and also aromatic carboxylic acid vinyl esters. Among these vinyl esters, vinyl acetate esters are preferable in terms of price. Ethylene content of EVOH is 20 to 65 mol , Preferably 25 to 50 moles The degree of saponification of the vinyl ester component is 90 mol The above, preferably 95 mol That's it. 20 moles of ethylene If less than, when humidity is high, gas barrier property will fall, and 65 mol When exceeding, gas barrier property is not enough. On the other hand, 90 degrees of safflower If less than that, when the humidity is high, not only the gas barrier property is lowered, but also the thermal stability of the EVOH is deteriorated, and gel is likely to occur on the surface of the obtained film.

EVOH also contains smaller amounts of α-olefins such as propylene, isobutene, 4-methylpentene-1, hexene, octene, unsaturated carboxylic acids such as itaconic acid, methacrylic acid, acrylic acid, maleic acid, salts thereof, portions thereof, or Vinyl silane-based compounds such as complete esters, nitriles thereof, amides thereof, anhydrides thereof, and vinyltrimethoxysilane, unsaturated sulfonic acids, salts thereof, alkylthiols, and N-vinylpyrrolidone may also be contained. none.

In addition, the EVOH may be a mixture of two or more EVOHs having different ethylene contents, and may also be a mixture of two or more EVOHs having different degrees of polymerization or saponification. Moreover, ethylene content, polymerization degree, and saponification degree may all differ. Also, the EVOH layer may be a multilayer of two or more EVOHs having different ethylene contents and the like.

In addition, EVOH includes various additives such as antioxidants, pigments, ultraviolet absorbers, lubricants, antistatic agents, plasticizers, crosslinking agents such as boric acid, inorganic fillers, and inorganic drying agents, polyamides, polyolefins, and high-quality aqueous resins, without affecting the present invention. Various resins, such as these, can be mix | blended.

In the present invention, the measuring method of P value, that is, the measuring method of the piston ascending speed of the melt indexer has an internal diameter of 2 And the length is 1 Nozzle with inner diameter of 9.5 Melt indexers with phosphorus cylinders [JIS K7210; Takara Bridge Co., Ltd., melt indexer L 203 type] 300 Heating, and 5 g of sample resin is added to the cylinder, and then a load of 2.16 kg is immediately applied to discharge 1 g of resin from the nozzle, and the load is immediately removed and the outlet of the nozzle is immediately blocked (e.g., a diameter of 2 Phosphorus metal needle is inserted into the nozzle and sealed), and then a load of 480g is applied to activate the stop position. It is to measure the time until it rises.

It is important that the range of the P value is 45 seconds to 15 minutes, preferably 1 minute to 15 minutes, more preferably 1 minute to 10 minutes, and most preferably 2 minutes to 10 minutes. The EVOH layer obtained by coextrusion coating at a typical extrusion temperature even with a P value of less than 45 seconds has a good surface of the membrane, but if the extrusion temperature is increased for high speed processing to improve productivity, The resulting EVOH layer tends to become a film containing bubbles resulting from pyrolysis of EVOH and results in poor appearance. On the other hand, when it exceeds 15 minutes, the adhesive force of adhesive resin and EVOH will fall easily.

EVOH (A) used in the present invention is typically obtained by the following method. That is, volatile matter [20 EVOH 120 Volatile weight loss rate (drying basis) when drying for 24 hours at Below, suitably 0.2 Or less, more preferably 0.15 Drying to less than or equal to 70 to 2000ppm, preferably 70 to 1000ppm, more preferably 100 to 1000ppm, alkali metal ions 15 to 400ppm, preferably 20 to 300ppm, more preferably 30 to It is obtained by containing 200 ppm, alkaline earth metal ions 10-300 ppm, suitably 30-200 ppm, more suitably 50-150 ppm. In addition, when the alkali metal ions are 100 ppm or more, a small amount or good content of the alkaline earth metal ions may be sufficient, and when the alkali earth metal ions are 50 ppm or more, the alkali metal ions may be good even if they are a small amount or no content.

Acid groups in the present specification are preferably pKa (25). Acidity index in) Acids of 3.5 or more, such as acetic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, citric acid, lauric acid, oleic acid, stearic acid, behenic acid, benzoic acid, aspartic acid, aminobenzoic acid, glutamic acid Hydrogen atoms are removed from organic acids such as organic acids and boric acids, and are added as compounds such as acids, acid anhydrides or metal salts. Moreover, as other acidic groups, phosphoric acid groups, such as inorganic acidic substances, such as potassium dihydrogen phosphate and sodium dihydrogen phosphate, are mentioned. Examples of the alkali metal ions include lithium ions, sodium ions, potassium ions, and the like, and examples of the alkaline earth metal ions include magnesium ions, calcium ions, and barium ions. Such metal ions can be added as compounds such as carbonates, acetates, phosphates, sulfates, nitrates, borates, hydroxides and chlorides.

When added with sodium carbonate, only sodium ions are contained, but when added with metal salts such as sodium acetate, calcium acetate, potassium dihydrogen phosphate and sodium dihydrogen phosphate, both acid groups and metal ions need to be calculated. have.

In the present invention, APO (B) is an unsaturated carboxylic acid such as maleic anhydride, modified with an olefin polymer having 2 to 8 carbon atoms such as ethylene, propylene, butene-1 or two or more internally different olefin copolymers of these olefins, and also with these olefins. And copolymers with other comonomers. These APOs can be used alone and can be used in combination with the above-mentioned (co) polymers which are not modified with maleic anhydride or the like. In addition, two or more APO may be used in combination. In addition, these APOs can be blended with various resins such as antioxidants, pigments, ultraviolet absorbers, lubricants, antistatic agents, plasticizers, crosslinking agents, inorganic fillers, inorganic desiccants, and thermoplastic resins within the scope of not impairing the present invention. have.

As the basic polyethylene used in APO, propylene, butene-1, 4-methylpentene-1, 1-hexene, 1-octene, 5, which is a ethylene homopolymer of high density polyethylene, medium density polyethylene, low density polyethylene, and ethylene as a main component, 5 Ethylidene-2-norbornene, 5-methylene-2-norbornene, styrene, vinyl acetate, methyl acrylate, ethyl acrylate, acrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid, glycerin methacrylate Copolymers of dill, maleic anhydride, itaconic anhydride, and the like. Among these copolymers, the copolymer of ethylene with acrylic acid or methacrylic acid may be an ionomer crosslinked with sodium, zinc aluminum, or the like. The copolymer of vinyl acetate with some or all of the vinyl acetate components may be saponified. Substances graft-modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic anhydride and maleic anhydride, salts thereof or esters thereof are employed as these basic polyethylenes as APO. However, the main chain containing unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride and itaconic anhydride in the main chain may be unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic anhydride, maleic anhydride, salts thereof or esters thereof. It is possible to denature the graft and not to denature the graft.

Polypropylene used for APO, which is a homopolymer of propylene and ethylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1 and 5-ethylidene-2-, which are mainly composed of propylene. Copolymers of norbornene, 5-methylene-2-norbornene, 1,4-hexadiene, styrene and the like with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic anhydride, maleic anhydride, salts thereof or esters thereof The graft denaturation can be listed.

Polybutene-1 used in APO, which is a homopolymer of butene-1 and ethylene, propylene, butene-2, isobutylene, butadiene, pentene-1, 4-methylpentene-1, and hexene, mainly composed of butene-1. And graft-modified copolymers of -1, octene-1 and the like with carboxylic acids such as acrylic acid, methacrylic acid, itaconic anhydride and maleic anhydride, salts thereof or esters thereof.

In the present invention, when the total layer thickness of the EVOH layer is a μm, the total layer thickness of the APO layer is b μm, and the thickness per layer of the APO layer is b 'μm,

0.5 ≦ a ≦ 20, 0.5 ≦ b ′ ≦ 20, 1 ≦ a + b ≦ 30;

Preferably 0.5 ≦ a ≦ 15, 0.5 ≦ b ′ ≦ 15, 1 ≦ a + b ≦ 25;

More preferably, 1 ≦ a ≦ 10, 1 ≦ b '≦ 10, and 2 ≦ a + b ≦ 20 are appropriate.

When the total layer thickness (a) of the EVOH layer is in the range of 0.5 to 20 µm, a multilayer film excellent in gas barrier properties and bend resistance can be obtained. Further, according to the present invention, the overall layer thickness a of the EVOH layer can be made thin, thereby reducing the amount of expensive EVOH used and economical. Moreover, when the thickness (b ') per layer of APO layer is 0.5-20 micrometers, the interlayer adhesive force with EVOH is enough, and the multilayer film excellent in transparency can be obtained. In addition, when the range of the total layer thickness of the EVOH layer and the total layer thickness of the APO layer (a + b) is 1 to 30 µm, the safety of the melts of (A) and (B) is good and occurrence of film cleavage It is possible to obtain a multilayer film having little and excellent bending resistance. By satisfying all of these conditions, a multilayer constitution film having productivity, economy, strength and the like can be obtained.

In order to obtain a coextruded film having a uniform thickness distribution in each of the layers and the entire layer, the melt index (in the case of EVOH is a compound) of the EVOH melt index (temperature 230 according to JIS K 7210) , Internal diameter 2 at load 2,16 kg When the weight discharged from the nozzle for 10 minutes, hereinafter abbreviated as MFR) is set to ηEg / 10min and the MFR of APO is set to ηEg / 10min.

1 ≤ηE≤80, 1 ≤ηA≤80, 0.08 ≤ηE / ηA≤8,

Preferably 2 ≦ ηE ≦ 70, 2 ≦ ηA ≦ 60, 0.1 ≦ ηA / ηA ≦ 5,

More preferably, it is 3 <= E> <= 50, 3 <= (eta) A <= 40, 0.2 <= (eta) E / (eta) A <= 3. When eta E or eta A is in the range of 1 to 80, a coextrusion film having a small increase in the width of the neckline and a uniform thickness distribution is obtained. Moreover, when (eta) E / (eta) A is the range of 0.08-8, the width | variety of the thickness nonuniformity of the width direction is little occurring in a coextrusion film, and the appearance defect by a wood grain, a bark pattern, etc. can be prevented.

In the present invention, the composition of the molten multilayer body composed of EVOH and APO may include EVOH / APO, APO / EVOH / APO, EVOH / APO / EVOH, EVOH / APO / EVOH / APO, and the like. The molten multilayer body of, for example, EVOH / APO / thermoplastic resin, APO / EVOH / thermoplastic resin, APO / EVOH / APO / thermoplastic resin, EVOH / APO / EVOH / thermoplastic resin and the like. Either side of EVOH or APO of such a molten multilayer body may be laminated on the substrate (C), and one or both sides of the molten multilayer body and / or the substrate may be ozonated or corona treated before being laminated to the substrate.

In the present specification, as the thermoplastic resin, a raw material thermoplastic resin used for the following sealing material (for example, a heat sealing material) and a thermoplastic resin used for the following substrate (C) can be used.

In the present invention, as the coextruded coated substrate (C), polyolefins such as high density, medium density, low density polyethylene and polypropylene; Polyesters such as polyethylene terephthalate and polyethylene naphthalate; Polyamides such as poly-caprolactam, polyhexamethyleneadipamide, polymethaxylyleneadipamide; Unstretched films made of thermoplastic resins such as polyvinylidene chloride, polystyrene, polyacrylonitrile and polycarbonate; A uniaxial stretched film, a biaxially stretched film, a rolled film, or a sheet can be enumerated as an appropriate thing, Other papers, such as graft paper and a carton paper, cellophane, aluminum foil, etc. can also be enumerated. The base material, especially the branch film, may be deposited with metal or metal oxide, may be printed, may be coated with a primer, and two or more of these treatments may be performed. It is preferable to set the thickness range of the base material (C) to 10-1000 micrometers, especially 10-200 micrometers, especially 10-100 micrometers, more especially 15-60 micrometers from a viewpoint of strength and economy.

In this invention, it is suitable to use the lamination agent (C) which has the resin (M-TR) layer in which at least one surface gave adhesiveness as a base material (C), since adhesiveness with (B) layer is improved more. In the present specification, the laminating agent (C) having an M-TR layer is a propylene copolymer, a butene polymer, or polyethyleneimine as an M-TR resin for imparting adhesion to at least one surface of various resins, particularly various thermoplastic resin layers. And polymers selected from modified cellulose are laminated. In the present specification, as the M-TR, for example, a multi-layered writing film such as (C) / (B) / (A) is used. , Relative humidity 65 , Distance between chucks 50 Tensile speed 250 T peel test under the condition of / min, causing material breakdown between layers (C) and (B) and the adhesive strength could not be measured, or the adhesive strength was 70g / 15 Is more than the width of, preferably 100g / 15 Is more than the width of, more preferably 150 g / 15 It is preferable that it is more than the width of. Surface treatment such as corona discharge treatment, chromic acid treatment, flame treatment, ozone treatment, sand blast treatment, vacuum deposition treatment such as aluminum or aluminum oxide is performed on one or both surfaces of the laminate (C) having the M-TR layer. can do. As a base of the substrate (C), a polypropylene film, in particular a biaxially stretched polypropylene film (OPP), for example, a stretch area magnification of 10 times or more, suitably 18 times or more of OPP is used for strength and printing aptitude such as tensile strength. As it improves, it is appropriate. Moreover, it is preferable to set the thickness range of the M-TR resin layer laminated | stacked in order to provide adhesiveness to 0.01-15 micrometers, especially 0.1-10 micrometer at the light point of adhesiveness and economical efficiency. The adhesive side of M-TR is laminated | stacked so that it may adjoin each other with (B) layer.

The propylene copolymer in the M-TR resin laminated to impart adhesiveness is chlorinated polypropylene; Ethylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, octene-1, 5-ethylriten-2-norbornene, 5-methylene-2-norbornene based on propylene, Copolymers with 1,4-hexadiene, styrene and the like; Graft modified products such as maleic anhydride using carboxylic acid and combinations thereof, or combinations thereof with propylene copolymers and propylene homopolymers. These propylene copolymers have a melting point of 10 than the base OPP. Or more, preferably 15 More preferably 20 It is preferable that the above is low because the effects of the present invention can be sufficiently obtained.

Butene-based polymers in the M-TR resin laminated to impart adhesion are homopolymers of butene-1; Copolymers of ethylene, propylene, butene-2, isobutylene, butadiene, pentene-1, 4-methylpentene-1, hexene-1, octene-1 and the like, and combinations thereof based on butene-1; It is a compound of the homopolymer of butene type polymer of and a propylene, or the above propylene copolymer.

Polyethylenimine in M-TR resins laminated to impart adhesion refers to polymers of arididine or two or more copolymers of arididine and derivatives thereof and / or comonomers copolymerizable with arididine and added thereto It is a polymer to which a comonomer can be added.

Modified cellulose in M-TR resin laminated in order to impart adhesiveness is an ester of cellulose, and typical examples thereof include cellulose acetates such as cellulose triacetate and cellulose diacetate and nitrocellulose.

In the present invention, there is no particular limitation on the lamination method with a biaxially stretched polypropylene film and a polymer selected from a propylene copolymer, butene-based polymer, polyethyleneimine, and modified cellulose, which are laminated for imparting adhesion, and biaxially stretched polypropylene. The polypropylene which is a raw material of a propylene film and the multilayer sheet obtained by coextrusion of the said polymer can be biaxially stretched, The polymer is extruded into the polypropylene sheet which is a raw material of a biaxially stretched polypropylene film, etc. The multilayer sheet obtained by laminating by lamination may be biaxially stretched, and the polymer may be laminated on a biaxially stretched polypropylene film by an extrusion lamination method or a solution coating method. When printing on such a biaxially stretched polypropylene film, it is preferable to laminate | stack a polymer for providing adhesiveness to a printing surface. By using the biaxially stretched polypropylene film (C) provided with such adhesiveness, the adhesion between the layer (B) and the layer (C) is remarkably improved, and the boiling resistance and pinhole resistance are greatly improved. Polymers laminated for imparting adhesion are particularly preferred because the propylene copolymers or butene polymers described above sufficiently achieve the effects of the present invention.

Moreover, in this invention, a sealing material can also be laminated | stacked on at least one surface of a coextrusion coating film. Polypropylene, polyethylene, polyester, polyamide and polyacrylonitrile may be used as the sealant to be laminated. These may be used alone or in combination of two or more. It is preferable that it is melting | fusing point or low softening point. Viket softening point (JIS K 7206) is 15 Or more, preferably 25 It is preferable to use the sealing material layer which consists of a thermoplastic resin with a low abnormality.

The polypropylenes used in the sealant are homopolymers of propylene and ethylene, butene-1, 5-ethylritene-2-norbornene, 5-methylene-2-norbornene, 1,4-hexadiene, based on propylene. And graft-modified copolymers with carboxylic acids such as maleic anhydride and salts thereof or esters thereof.

In addition, the polyethylene used for the sealing material is high density polyethylene, medium density polyethylene, low density polyethylene, and ethylene homopolymers of propylene, butene-1, 4-methylpentene-1, 1-hexene, 1-octene, 5 -Copolymers of ethylidene-2-norbornene, 5-methylene-2-norbornene, vinyl acetate, methyl acrylate, ethyl acrylate, acrylic acid, methyl methacrylate, ethyl methacrylate, methacrylic acid, and the like. . Among the copolymers described above, the copolymer with acrylic acid or methacrylic acid may be crosslinked with sodium, zinc, aluminum, or the like, and the copolymer with vinyl acetate may be part or all of the vinyl acetate component. The polyethylene may also be graft modified with carboxylic acids, such as maleic anhydride, salts thereof or esters thereof.

In addition, the polyester used for the sealing material is ethylene glycol, diethylene glycol, trimethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, 4,4'-dihydroxyl Polyhydric alcohol components, such as cidiphenyl-2,2-propane, glycerin, and pentaerythritol, hydroxycarboxylic acid components such as parahydroxybenzoic acid, δ-valerolactone, ∈-caprolactone, tartaric acid, terephthalic acid, isophthalic acid, various And polyesters obtained by using polyhydric carboxylic acids such as naphthalene dicarboxylic acid, azelaic acid, sebacic acid, pimelic acid, adipic acid, ketalic acid, succinic acid and ester components thereof as raw materials.

In addition, the polyamide used as the sealing material is a diamine component such as hexamethylenediamine, piperazine, tetramethylenediamine, ethylenediamine, and methacrylyldiamine, δ-valetolactam, ∈-caprolactam, ω-laurolactam, ω Raw materials include aminocarboxylic acid components such as aminoundecanoic acid and aminododecanoic acid, and polyvalent carboxylic acid components such as various naphthalenedicarboxylic acids, terephthalic acid, isophthalic acid, azelaic acid, sebacic acid, pimelic acid, adipic acid, glutamic acid and succinic acid. Polyamide etc. which are obtained by this are mentioned.

Moreover, the polyacrylonitrile used as a sealing material has acrylonitrile as a main component, and copolymers, such as styrene, methyl methacrylate, methyl acrylate, ethyl methacrylate, ethyl acrylate, butadiene, etc. are mentioned. In addition, various resins, such as various additives, such as an antioxidant, a pigment ultraviolet absorber, a lubricant, an antistatic agent, a plasticizer, a crosslinking agent, an inorganic filler, and an inorganic desiccant, and a thermoplastic resin are mix | blended with the said sealing material or base film in the range which does not inhibit this invention. can do. The thickness range of the sealant layer is appropriately selected depending on the weight of the contents, but 15 to 150 μm is suitable.

The method of laminating the base material (C), especially the base film, the EVOH (A) layer, the APO (B) layer, and the sealing material is based on co-extrusion of the molten multilayer body of the (B) layer and the (A) layer on the base film. In this case, the sealant film may be coextruded at the same time. In addition, the substrate may be coextruded with a molten multilayer body of layers (B) and (A) and subsequently extruded and laminated with a sealing material (a base material may be used in each step, and a base material may be used only in one step). And both processes may not use undercoats). The molten multilayer body of the layer (B) and the layer (A) may be coextruded to the substrate (a base material may be used), and then the sealing material film may be dried and laminated.

The extrusion temperature of the EVOH in the present invention is the extruder end temperature 220 More preferably, 225 More preferably 230 More preferably, 240 That's it. The upper limit of the extrusion temperature is not particularly limited and depends on the residence time of the EVOH in the extruder, but 300 I can raise it to a degree. By extruding at such a high temperature, the EVOH thin layer can be extruded at a high speed of at least 110 m / min, in particular at least 125 m / min, in particular at least 130 m / min, more in particular at least 150 m / min. The upper limit of the speed is not particularly limited, and may be raised to about 250 m / min, in particular about 300 m / min. In addition, by extruding at a high temperature, the adhesion between APO and EVOH is improved, and the productivity is improved due to the high speed, and the gas barrier property is also improved. High-speed extrusion requires high temperature extrusion, and in the conventional method, it is difficult to achieve high temperature because bubbles are generated at higher temperatures. Therefore, high speed extrusion is difficult, but the present invention solves these problems. In terms of industrial significance,

The coextruded coated film thus obtained has good adhesion between EVOH and APO and is suitable for various foods, pharmaceuticals, industrial medicines, and cosmetics, even when it is extruded at a high temperature without containing bubbles such as voids.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Also, wealth and It is said that it is based on weight unless there is a special messenger.

EXAMPLE

Example 1

OPP having a thickness of 25 µm (manufactured by Tokyo Cellophane Paper Co., Ltd .; Tosero HC-OP; 32 moles of ethylene in thermoplastic resin (propylene copolymer) (M-TR)} And saponification degree of 99.5 mol of vinyl acetate component , P value for 6 minutes (containing 9 ppm sodium ion, 65 ppm calcium ion, 870 ppm acetic acid group and 10 ppm phosphoric acid group, volatile content 0.1 270 EVOH It melt | dissolves in water and APO {made by Mitsui Seiki Yugagaku Kogyo Co., Ltd., ADMER SF 600 (polyethylene type adhesive resin)} 270 After melting at, the thickness of EVOH is 5 μm, the thickness of APO is 2 μm, and the APO is coextruded at 130 m / min so as to contact the M-TR surface of the OPP, and then the coextrusion coating composed of OPP / APO / EVOH A multilayer film was obtained, followed by application of 0.2 g / m &lt; 2 &gt; After evaporating the solvent in, low-density polyethylene {Mirason 11 made by Mitsui Seki Yukagaku Kogyo Co., Ltd.} was used as a sealing material. Melted at 20 μm and extruded and laminated on the EVOH side at a thickness of 20 μm, and finally low density polyethylene (Mirason 11, manufactured by Mitsui Seki Yukagaku Kogyo Co., Ltd. Melt at 320 with a thickness of 40 μm The laminated film is obtained by extrusion lamination onto a low density polyethylene surface extruded at.

EVOH with a P value of 6 minutes was obtained from EVOH containing sodium dihydrogen phosphate, calcium acetate and sodium acetate.

Oxygen barrier property of the said laminated | multilayer film was 1.4 ml / m <2> * atm (Made by the modern control company, using OX-TRAN 10/50 type | mold) , 65 Measured in RH), bubbles are not generated in the EVOH layer and the appearance is good. Lamination Strength of APO and EVOH (T-type Peel, Speed 250 / min, sample width 15 Degree 270 g / 15 More than width (first, OPP and APO are 270g / 15 APO and EVOH lamination strength is 270g / 15 It is more than width).

Comparative Example 1

In Example 1, the P value was 3 seconds (containing 100 ppm of sodium ions, 150 ppm of calcium ions, and 20 ppm of acetic acid groups, and a volatile content of 0.3). A laminated film is obtained on the same conditions as Example 1 except having changed to EVOH. Bubbles are generated in the EVOH layer and are poor in appearance.

EVOH having a P value of 3 seconds was obtained from EVOH containing sodium acetate and calcium acetate.

Comparative Example 2

In Example 1, the P value was 18 minutes (containing 10 ppm of potassium ions, 5 ppm of calcium ions, 50 ppm of acetic acid groups and 20 ppm of phosphate groups, and a volatile content of 0.05). Except having changed into EVOH which is), the laminated | multilayer film is obtained on the conditions similar to Example 1. The appearance is good, but the lamination strength of APO and EVOH is 30g / 15 Small in width and problematic.

EVOH having a P value of 18 seconds was obtained from EVOH containing potassium dihydrogen phosphate, calcium acetate and acetic acid.

Comparative Example 3

Ethylene content is 47 moles in OPA {cononine, carbonyl R} with a thickness of 15 μm , 99.5 mol saponification degree of vinyl acetate component , P value 30 seconds (containing 320 ppm of calcium ions and 400 ppm of acetic acid, volatile matter 0.06 250 EVOH Melted, and APO {maleic anhydride graft modified ethylene propylene copolymer, density 0.89 g / cm 3} was 240 After melting at, the thickness of EVOH is 4 μm, the thickness of APO is 4 μm, and the APO is coextruded at 120 m / min so that the APO is in contact with OPA, and then the multilayer film by the coextrusion coating of OPA / APO / EVOH composition is prepared. Then, 0.2 g / m <2> was apply | coated on the EVOH side as a solid content as solid, and 70 was then After evaporating the solvent in, low density polyethylene {Mirason 11 made by MitM Iseki Yukagaku Kogyo Co., Ltd.} Melted at 20 μm and extruded and laminated on the EVOH side at a thickness of 20 μm, and finally low density polyethylene (Mirason 11, manufactured by Mitsui Seki Yukagaku Kogyo Co., Ltd. Melt at 320 with a thickness of 40 μm The laminated film is obtained by extrusion lamination onto a low density polyethylene surface extruded at.

EVOH having a P value of 30 seconds was obtained from EVOH containing calcium acetate.

The oxygen barrier property of the laminated film is 13 ml / m 2 day · atm, and bubbles are not generated in the EVOH layer and the appearance is good. 270g / 15 lamination strength of APO and EVOH More than width (first, OPP and APO are 270g / 15 APO and EVOH lamination strength is 270g / 15 It is more than width). However, although a higher speed processing is attempted, melt film cutting occurs and this becomes a problem in terms of high speed workability. Thus, EVOH and APO 270 The temperature was lowered and the high-speed processing was attempted, but even in the high-speed processing of 130 m / min, no melt film was cut, but bubbles were generated in the EVOH layer and the appearance was poor.

Example 2

0.2 g / m <2> was apply | coated as a solid content to the PET {Dia foil Co., Ltd. product, H-500} of 12 micrometers in thickness, and 70 After evaporating the solvent in ethylene, 44 mol And saponification degree of 99.5 mol of vinyl acetate component , P value for 3 minutes (containing 200 ppm sodium ion and 200 ppm acetic acid, 0.1 volatilization) 250 EVOH Melt | dissolved in an APO (made by Sumitomo Kagaku Kogyo Co., Ltd., Bondine TX 8030 (polyethylene adhesive resin)} 280 After melting at, the thickness of each is 10 μm, the APO side is ozonated (take air at an ozone concentration of 15 g / m 3 at a rate of 160 ml / m 2), and then at 140 m / min to allow APO to contact PET. Coextrusion coating affords a coextrusion coating film of PET / APO / EVOH construction.

EVOH having a P value of 3 minutes was obtained from EVOH containing sodium acetate.

3 g / m <2> apply | coated to the EVOH surface of the said coextrusion coating film as a solid content the adhesive for drying lamination | mixing (Takerak A-385 / Takenate A-50 by the ratio of 6-1) by Takeda Yakuhinkogyo Co., Ltd. as a solid content. 70 After evaporating the solvent at, a low-density polyethylene film (manufactured by Aisero Kagaku Co., Ltd., Suzuron LS 201) having a thickness of 60 µm was laminated on the adhesive lamination surface for dry lamination to obtain a laminated film.

The oxygen barrier property of the coextrusion coating film is good at 3.9 ml / m 2 · day · atm, and bubbles are not generated in the EVOH layer, and the appearance is good. Lamination Strength of APO and EVOH is 330g / 15 It is good in width.

Example 3

0.2 g / m <2> was apply | coated as a solid content to the corona treatment surface of 20 micrometers OPP {made by Tokyo Cellophane Paper Co., Ltd., Tosero OP-UI}, 70 After evaporating the solvent at 32 moles of ethylene , 99.5 mol saponification degree of vinyl acetate component , P value for 2 minutes (70 ppm sodium ion, 120 ppm calcium ion, 800 ppm acetic acid group and 110 ppm phosphoric acid group, volatile content 0.08 250 EVOH Melt | dissolved in an APO (made by Mitsui Seki Yukagaku Kogyo Co., Ltd., ADMER SF 600 (polyethylene adhesive resin)} 260 Melted in a low-density polyethylene {Mirason 11 made by Mitsui Sekiyukagaku Kogyo Co., Ltd.} 320 Molten multilayers composed of low-density polyethylene / APO / EVOH were each co-extruded at 130 m / min to have a thickness of 5 μm and EVOH was in contact with the OPP surface, followed by low-density polyethylene Myrason 11} It melt | dissolved in the and and it extrusion-laminated on the low density polyethylene side with a thickness of 40 micrometers, and obtains a laminated film.

EVOH with a P value of 2 minutes was obtained from EVOH containing sodium dihydrogen phosphate, calcium acetate and acetic acid.

The oxygen barrier property of the coextrusion coating film was good at 1.4 ml / m 2 · day · atm, and bubbles were not generated in the EVOH layer, and the appearance was good. Lamination Strength of APO and EVOH 310g / 15 It is good in width.

Example 4

The corona treatment is performed on 200 g / m 2 fine paper, and first, low-density polyethylene {Mirason 11 made by Mitsui Seki Yukagaku Kogyo Co., Ltd.} After melt at, it is extruded and laminated on the corona treated surface to a thickness of 20μm. Subsequently, 44 mol of ethylene content , 99.5 mol saponification degree of vinyl acetate component , P value for 6 minutes (135 ppm of sodium ion, 60 ppm of acetic acid group and 40 ppm of phosphate group, 0.1 volatilization) 280 EVOH It melt | dissolves with an APO (made by Mitsui Seki Yukagaku Kogyo Co., Ltd., ADMER NF 550 (polyethylene adhesive resin)} 280 Melt at 10 μm each and co-extruded at 170 m / min so that APO contacts the low density polyethylene side, and then 0.2 g / m 2 as a solid is applied to the EVOH side as a solid, 70 After evaporating the solvent in low density polyethylene 310 Melt, and by extrusion lamination on the EVOH side with a thickness of 40 μm, a coextruded coated film of constitution paper / LDPE / APO / EVOH / LDPE is obtained.

EVOH having a P value of 6 minutes was obtained from EVOH containing sodium hydrogen phosphate and sodium acetate.

The oxygen barrier property of the coextrusion coating film is good at 3.8 ml / m 2 · day · atm, and bubbles are not generated in the EVOH layer, and the appearance is good. Lamination Strength of APO and EVOH 350g / 15 It is good in width.

Example 5

Ethylene content is 32 mol in pre OPP {Tokyo Cellophane Paper Co., Ltd. product, Tosero OP-U-2} which corona-treated both sides which is 20 micrometers in thickness , 99.5 mol saponification degree of vinyl acetate component , P value for 6 minutes (containing 9 ppm sodium ion, 65 ppm calcium ion, 870 ppm acetic acid group and 10 ppm phosphoric acid group, volatile content 0.1 250 EVOH It melt | dissolves with an APO (made by Mitsui Seki Yukagaku Kogyo Co., Ltd., ADER NF 550 (polyethylene adhesive resin)} 280 After melting in, the thermoplastic resin (manufactured by Mitsui Seiki Yugagaku Kogyo Co., Ltd., ADER QF 551 (polyethylene adhesive resin)) 270 was again used. The molten multilayer body of the APO / EVOH / thermoplastic resin composition melted at was 3μm / 5μm / 3μm in thickness, and co-extruded at 130m / min so that the APO side was in contact with the OPP, and then OPP / APO / EVOH / thermoplastic A coextruded coated film of constitution is obtained.

EVOH with a P value of 6 minutes was obtained from EVOH containing sodium dihydrogen phosphate, calcium acetate and sodium acetate.

3 g / m <2> of dry lamination | adhesive adhesives (Takeda Yakuhin Kogyo Co., Ltd. make, Takerak 1-385 / Takenate 1-50 in 6 to 1 ratio) apply | coated to the OPP surface of the said coextrusion coating film as solid content. 70 After evaporating the solvent at, the thickness is 60 μm and the content of vinyl acetate component is 5 weight Phosphorous ethylene-vinyl acetate copolymer film (manufactured by Aisero Kagaku Co., Ltd., Suzuron L E305) was laminated to obtain a laminated film.

The oxygen barrier property of the laminated film was good at 1.4 ml / m 2 · day · atm, and bubbles were not generated in the EVOH layer, and the appearance was good. In addition, the lamination strength of APO1 and EVOH is also 280 g / 15. It is good in width.

Vertical 230 which enclosed 100 ml of water with the said laminated | multilayer film , Width 150 A rectangular package of is obtained. Two overlapping ones, alone and in contact with other packages. Boil for 30 minutes at. No change in appearance such as peeling or blocking between packages is seen in any package, and the boiling resistance is good.

Example 6

Polypropylene homopolymer with a thickness of 1000 μm (melting point 168 Vicket Softening Store 150 ) And a polybutene-1 homopolymer (M-TR) having a thickness of 100 µm is stretched at an area magnification of 50 times to obtain a base film (C) having a total of 22 µm. 250 27 mol of ethylene content melted in And saponification degree of vinyl acetate component is 99.6 mol EVOH (A) with MFR of 7.0 g / 10 min and P value of 6 minutes (Vicket Softening Point 180 (Contains 10 ppm sodium ion, 65 ppm calcium ion, 90 ppm acetic acid group and 10 ppm phosphoric acid group, volatile content 0.09 ) And 220 Ethylene (75 weight, melted at, density 0.88 g / c ³ , MFR 7.0 g / 10 min) Propylene (25 weight) based on Maleic anhydride (0.1 weight) in copolymer with APO (B) grafted) was coextruded to cover the APO (B) layer with the M-TR surface of the base film (C) at a rate of 150 / min using Chloressa's feed block die, and the (A) layer And (B) a multilayer constituent film having a thickness of 2 µm each. In addition, the lamination strength between the base film and APO and APO and EVOH (T-type peeling, rate 250 / min, sample width 15) ) Is so large that material destruction of the coating occurs and is unmeasurable.

EVOH with a P value of 6 minutes was obtained from EVOH containing sodium dihydrogen phosphate, calcium acetate and sodium acetate.

The gas barrier property of such a film is 2 cc / m 2, day, atm (modern 20 using OX-TRAN 10/50 manufactured by Modern Control Co., Ltd.). Humidity 65 Measured in 3g / m <2> was apply | coated as a solid content to the EVOH side of the multilayer constitution film obtained by mixing the adhesive for dry lamination (Takerak A-385 and Takenate A-50 by weight ratio of 6-1) by Takeda Yakhin Kogyo Co., Ltd. And 70 After evaporating the solvent at, a low density polyethylene film having a thickness of 60 μm on this coated surface (manufactured by Aisero Kagaku Co., Ltd., Suzuron L S-210, hereinafter abbreviated as LDPE, Viket softening point 95 } (Heat seal layer) is laminated at a speed of 5 / min.

The film has a side sealing temperature of 155 using LDPE as a sealing layer. Bottom sealing temperature 160 Length 230 at speed, 60 packages / min , Width 150 Package was made and 100 ml of water was added and sealed with an in-pulse sealer to obtain a rectangular package. This 98 After boiling for 30 minutes at, no changes in ducts such as peeling and whitening were observed, and the boiling resistance was good. In addition, yellowing of the film does not occur even when exposed to a fluorescent lamp for one month.

Example 7

250 instead of APO used in Example 6 Adhesive low-strength polyethylene with a density of 0.90 g / cm3 and MFR 12 g / 10 min melted in 4-methylpentene-1 (15 weight) to make Maleic anhydride (0.08 weight) in the copolymer with ) Was carried out according to Example 6 except that APO consisting of grafted) was used.

The gas barrier property of this film is 2 cc / m 2 · day · atm. In addition, the lamination strength between the base film and APO and APO and EVOH is also good because material destruction of the coating occurs and the adhesive force is sufficient. Even if the film which laminated | stacked LDPE on the said multilayer film similarly to Example 1 as a package, and boiled similarly to Example 6, the external appearance changes, such as peeling and whitening, are not seen but the boiling resistance is favorable. In addition, yellowing of the film does not occur even when exposed to a fluorescent lamp for one month.

* 1: ml / ㎡, day, atm

* 2: g / 15 width; Interlaminar Peel Strength of EVOH / APO

* 1: ml / ㎡, day, atm

* 2: g / 15 width; Interlaminar Peel Strength of EVOH / APO

* 1: ml / ㎡, day, atm

* 2: g / 15 width; EVOH / APC Interlayer Peel Strength

PB-1: Polybutene-1

* 1: ml / m2, day, atm

* 2: g / 15 ; EVOH / APO Interlaminar Peel Strength

* 3: g / 15 ; Interlaminar Peel Strength of Base Film / APO

As described above, according to the present invention, even if the extrusion process at high temperature and high speed, it is possible to obtain a multilayer film having good adhesion between the EVOH and the adhesive resin without containing bubbles such as voids, and these are various foods, pharmaceuticals, industrial chemicals. And cosmetics.

Claims (4)

P value [Inner diameter is 2 And the length is 1 Nozzle with inner diameter of 9.5 Melt indexer with phosphor cylinder 300 The sample resin was charged with 5 g of sample resin and immediately loaded with 2.16 kg of sample resin to discharge 1 g of sample resin from the nozzle, the load was removed and the nozzle was sealed. Co-extrusion coating of substrate (C) with ethylene-vinyl ester copolymer saponification (A) and adhesive polyolefin resin (B) having a thermal decomposition behavior as Method for producing a multilayer structure characterized in that. The method for producing a multilayer structure according to claim 1, wherein the P value is 1 to 10 minutes. The base material C is laminated | stacked so that at least one surface may have the resin layer provided with adhesiveness, and the surface of the resin layer given the adhesiveness of (B) layer and the base material C is adjacent. Method for producing a multilayer structure. The method for producing a multilayer structure according to claim 1, wherein a sealing material is laminated on at least one side of the multilayer structure.