JP2001277352A - Method for manufacturing laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate excellent in gas barrier properties, moistureproofness, aroma retention or like and capable of obtaining a packaging bag excellent in sealability and appearance. SOLUTION: In manufacturing the laminate having layered constitution of polypropylene layer/adhesive resin layer/ethylene/vinyl acetate copolymer saponified matter layer/adhesive resin layer/heat seal layer, polypropylene, ethylene- vinyl acetate copolymer saponified matter and an adhesive resin are co-extruded to obtain a multilayered sheet having layered constitution of polypropylene layer/adhesive resin layer/ethylene/vinyl acetate copolymer saponified matter layer and this multilayered sheet is stretched at least in an extruding direction (MD direction) and the adhesive resin layer is laminated on the surface of the ethylene vinyl acetate copolymer saponified matter layer of the multilayered sheet and the whole is stretched in a lateral direction (TD direction) and a heat seal layer is further laminated on the surface of the adhesive resin layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate using a saponified ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVOH) as an intermediate layer, and a method for producing the same. TECHNICAL FIELD The present invention relates to a laminate excellent in suitability for bag making, which is capable of obtaining a packaging bag excellent in properties, fragrance retention and the like, and excellent in sealability and appearance, and a method for producing the same.

[0002]

2. Description of the Related Art In general, EVOH is excellent in transparency, gas barrier properties, fragrance retention, solvent resistance, oil resistance, and the like.
Utilizing such characteristics, it is used for various packaging materials such as food packaging materials, pharmaceutical packaging materials, industrial chemical packaging materials, agricultural chemical packaging materials, etc., and is also expected as a substitute film for the conventional vinylidene chloride coating film.

[0003] That is, a laminate having an EVOH layer laminated on the surface of a polyolefin film such as polypropylene via an adhesive layer, and is usually subjected to a stretching treatment for the purpose of improving the mechanical strength and the like of the laminate. It is a laminated body.

[0004] However, when such a laminate is used as a film for various packaging, the laminate is curled by the influence of heat, moisture, or the like due to the residual stress difference and relaxation contraction difference of each constituent resin. When the packaging bag is twisted, the sealing portion may be deformed or abnormal when the packaging bag is formed, which may hinder the appearance and performance of the packaging bag.

As a countermeasure, Japanese Patent Laid-Open Publication No. 58-3342 discloses
No. 7 discloses that the moisture-absorbing resin layer of a laminated film of a polyolefin resin layer and a moisture-absorbing resin layer (EVOH, etc.)
It is described that 5% by weight or more of water is absorbed.

[0006]

However, in the above method, since the EVOH layer as the barrier layer absorbs water, the barrier performance of the EVOH layer at an angle decreases, and the barrier performance of the EVOH layer is reduced. At the same time, it is difficult to make full use of it, and at the same time, there is a problem that the productivity of the laminated film is reduced due to the addition of the water absorption step.

Therefore, a laminate having excellent gas barrier properties, moisture-proof properties, fragrance retention properties, etc., as well as excellent sealing properties and appearance, and excellent in bag-making suitability is desired. .

[0008]

Accordingly, the present inventor has conducted intensive studies in view of the present situation, and as a result, has found that a polypropylene (PP) layer / adhesive resin layer / EVOH layer / adhesive resin layer / heat seal layer has been obtained. In producing a laminate having the layer configuration of (1), a multilayer sheet having a layer configuration of polypropylene (PP) layer / adhesive resin layer / EVOH layer was obtained by co-extrusion of polypropylene (PP), EVOH and an adhesive resin. Thereafter, the multilayer sheet is stretched at least in the extrusion direction (MD direction), and then the adhesive resin layer is laminated on the EVOH surface of the multilayer sheet, and then stretched in the width direction (TD direction). A laminate produced by laminating a heat seal layer on the surface of the EVOH layer can achieve the above object, and furthermore, the EVOH layer has a C-O
The inventors have found that when the orientation coefficient of the group is from -0.4 to -0.01, the effects of the present invention can be remarkably obtained, thereby completing the present invention.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The polypropylene (P) used in the present invention
No particular limitation is imposed on P), and homopolypropylene, ethylene-propylene block copolymer, ethylene-propylene random copolymer, blends thereof, and further PPs of these high-density polyethylene, medium-density polyethylene, low-density polyethylene, Linear low-density polyethylene,
Highly polymerized high-density polyethylene, high-polymerized low-density polyethylene, unsaturated carboxylic acid-modified polyethylene, unsaturated carboxylic acid-modified polypropylene, etc. blended at a ratio of 50% or less can be used. Index (MI) (230 ° C, load 2160g)
But 0.5 to 20 g / 10 min (further 1 to 15 g / 10 min)
(In particular, 2 to 7 g / 10 min) of PP is used, and when the melt index is smaller than the above range, the extrusion load becomes too large. Dimensional stability and mechanical strength are undesirably reduced.

The PP used in the present invention may contain, if necessary, an antistatic agent, an antifogging agent, an ultraviolet absorber, an antioxidant, a plasticizer, a lubricant, a nucleating agent, a dispersant, a colorant, an antibacterial agent. Agent,
Additives such as inorganic fillers can be added.

The EVOH used in the present invention is not particularly limited, but has an ethylene content of 20 to 70 mol%.
(More preferably 25 to 60 mol%), and a saponification degree of 80 mol% or more (more preferably 90 mol% or more). When the ethylene content is less than 20 mol%, gas barrier properties at high humidity and melting On the other hand, if it exceeds 70 mol%, sufficient gas barrier properties cannot be obtained, and if the saponification degree is less than 80 mol%, the gas barrier properties, heat stability, moisture resistance, etc. decrease, which is not preferable.

The EVOH has a melt index (MI) (210 ° C., load 2160 g) of 1 to 50 g.
/ 10 min (more preferably 2 to 30 g / 10 min). When the melt index is smaller than the above range, the inside of the extruder becomes a high torque state at the time of molding, and the extrusion process becomes unstable. If it is larger than this, the mechanical strength of the molded product is insufficient, which is not preferable.

The EVOH is obtained by saponification of an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer can be produced by any known polymerization method, for example, solution polymerization,
It is produced by suspension polymerization, emulsion polymerization, or the like, and saponification of an ethylene-vinyl acetate copolymer can also be performed by a known method.

In the present invention, a copolymerizable ethylenically unsaturated monomer may be copolymerized as long as the effects of the present invention are not impaired. Examples of such a monomer include propylene and 1-butene. , Olefins such as isobutene, acrylic acid, methacrylic acid, crotonic acid, (anhydrous) phthalic acid,
Unsaturated acids such as (anhydride) maleic acid and (anhydride) itaconic acid or salts thereof, mono- or dialkyl esters having 1 to 18 carbon atoms, acrylamide, 1 to 1 carbon atoms
8, acrylamides such as N-alkylacrylamide, N, N-dimethylacrylamide, 2-acrylamidopropanesulfonic acid or a salt thereof, acrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, methacrylamide, having 1 to 18 carbon atoms Methacrylamides such as N-alkyl methacrylamide, N, N-dimethyl methacrylamide, 2-methacrylamidopropanesulfonic acid or a salt thereof, methacrylamidopropyldimethylamine or an acid salt thereof or a quaternary salt thereof, N-vinylpyrrolidone N-vinylamides such as, N-vinylformamide and N-vinylacetamide;
Vinyl cyanides such as acrylonitrile and methacrylonitrile, vinyl ethers such as alkyl vinyl ethers having 1 to 18 carbon atoms, hydroxyalkyl vinyl ethers and alkoxyalkyl vinyl ethers, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride and vinyl bromide And vinylsilanes such as trimethoxyvinylsilane, allyl acetate, allyl chloride, allyl alcohol, dimethylallyl alcohol, trimethyl- (3-acrylamido-3-dimethylpropyl)-
Examples thereof include ammonium chloride and acrylamide-2-methylpropanesulfonic acid. Further, post-modification such as urethanization, acetalization, and cyanoethylation may be performed as long as the gist of the present invention is not impaired.

Further, in the present invention, as EVOH,
The use of a mixture of two or more types is also preferable in that stable stretching is possible and the resulting molded product has a uniform film thickness. In such a case, the ethylene content and / or the degree of saponification of EVOH to be mixed are preferable. It is preferable to change the ethylene content at this time by at least 4 mol% (further 6 to 2
0 mol%, especially 6 to 15 mol%), and when the difference is less than 4 mol%, the effect of improving the stretchability is undesirably small. When three or more types of EVOH are mixed, the difference between the one having the minimum ethylene content and the one having the maximum ethylene content should satisfy the above condition. Similarly, the difference in the degree of saponification is preferably at least 1 mol% (more preferably 1.5 to 10 mol%, particularly 2 to 5 mol%). The effect of improving stretchability is undesirably reduced. E mixed
When there are three or more VOHs, the difference between the minimum and maximum saponification degrees among them should satisfy the above condition, as in the above case.

Further, in the present invention, the EV as described above is used.
As long as the object of the present invention is not impaired in the OH or EVOH composition, a saturated aliphatic amide (eg, stearic acid amide, etc.), an unsaturated fatty acid amide (eg, oleic acid amide, etc.), a bisfatty acid amide (eg, ethylenebisstearic acid amide) Lubricants such as fatty acid metal salts (eg, calcium stearate, magnesium stearate, etc.), low molecular weight polyolefins (eg, low molecular weight polyethylene having a molecular weight of about 500 to 10,000, or low molecular weight polypropylene, etc.), and inorganic acids (eg, boric acid) , Phosphoric acid, etc.),
Organic acids (eg, acetic acid, stearic acid, etc.), inorganic salts (eg, calcium phosphate, hydrotalcite, etc.), organic salts (eg, sodium acetate, magnesium acetate, etc.), plasticizers (eg, aliphatic acids such as ethylene glycol, glycerin, hexanediol, etc.) Polyhydric alcohols), oxygen absorbers (eg, reduced iron powders, ascorbic acid, etc.), heat stabilizers,
Light stabilizers, antioxidants, ultraviolet absorbers, coloring agents, antistatic agents, surfactants, antibacterial agents, deodorants (eg, activated carbon), antiblocking agents (eg, talc particles), slip agents (eg, A fixed silica or the like), a filler (for example, an inorganic filler or the like), another resin (for example, a polyolefin, a polyamide or the like) may be blended.

The adhesive resin used in the present invention is not particularly limited, but a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof is preferably used. Examples of the unsaturated carboxylic acid include acrylic acid and methacrylic acid. Acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, etc., and their esters and anhydrides can also be used. Further, as the derivatives, methyl acrylate, methyl methacrylate, ethyl acrylate , Propyl acrylate, butyl acrylate, butyl methacrylate, vinyl acetate, glycidyl acrylate, glycidyl methacrylate, acrylamide, methacrylamide, sodium acrylate, etc., and as the polyolefin resin, polyethylene, polypropylene , Ributen, and copolymers thereof, ethylene - vinyl acetate copolymer, ethylene - and acrylic acid ester copolymer. At this time, the amount of the unsaturated carboxylic acid or its derivative contained in the polyolefin resin is 0.001 to 3% by weight.
Is preferably 0.01 to 1% by weight, particularly preferably 0.03 to 0.5% by weight. When the amount of modification in the modified product is small, the effect of improving interlayer adhesion is poor,
Conversely, if the amount is too large, a crosslinking reaction may occur, and the moldability may deteriorate, which is not preferable. In addition, these adhesive resins are improved in adhesiveness by blending a rubber / elastomer component such as polyisobutylene and ethylene-propylene rubber, or a polyolefin resin different from the base polyolefin resin of the adhesive resin. There is useful.

In the production method of the present invention, first, it is necessary to obtain a multilayer sheet having a layer structure of PP layer / adhesive resin layer / EVOH layer.
What is necessary is just to co-extrude PP, an adhesive resin, and EVOH, and in this co-extrusion, a well-known method and apparatus can be adopted. The melting temperature at this time can be selected from 150 to 300 ° C. (further, 180 to 280 ° C.) for PP, and 170 to 300 ° C. for EVOH.
(Further 200-280 ° C),
In the case of an adhesive resin, 150 to 300 ° C. (and 180 to 300 ° C.)
280 ° C.).

Next, the multilayer sheet obtained above is stretched at least in the extrusion direction (MD direction). The stretching is not particularly limited, and a known method and apparatus can be adopted. Of the roll stretching method, tenter stretching method, tubular stretching method, and the like, those having a high stretching ratio can be employed.

The stretching ratio when the above-mentioned multilayer sheet is stretched in the extrusion direction (MD direction) is 2 to 10 times (further 3 times).
If it is less than 2 times, the effect of improving the mechanical strength and moisture resistance by stretching will be insufficient, and if it exceeds 10 times, the tear resistance of the obtained stretched multilayer sheet will be reduced. Subsequently, when the film is stretched in the width direction (TD direction), the stretching becomes unstable, which is not preferable. Next, the adhesive resin is laminated on the surface of the EVOH layer of the obtained multilayer sheet. In this case as well, the adhesive resin is extruded and laminated or the adhesive resin sheet (layer ) May be dry-laminated.

Before the adhesive resin is laminated on the above-mentioned multilayer sheet, corona discharge treatment, chromic acid treatment, flame treatment, ozone treatment, sand blast treatment, anchor coat treatment, vacuum deposition, etc. Surface treatment such as treatment may be performed. After laminating the adhesive resin, the obtained multilayer sheet of PP layer / adhesive resin layer / EVOH layer / adhesive resin layer is stretched in the width direction (TD direction). 2 to 20 times (further 4-1
5 times) is preferable, and if it is less than 2 times, the effect of improving the mechanical strength, gas barrier properties, and moisture resistance by stretching becomes insufficient, and if it exceeds 20 times, local unevenness in the thickness of the obtained stretched multilayer sheet is reduced. It is not preferable because it breaks.

In any of the above stretching, 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.
-170 ° C, preferably 2-600 at 100-160 ° C
Heat treatment is performed for about a second.

The stretched multilayer sheet may be subjected to a surface treatment such as a corona discharge treatment, a chromic acid treatment, a flame treatment, an ozone treatment, a sand blast treatment, an anchor coat treatment, and a vacuum deposition treatment, if necessary.

The total thickness of such a stretched multilayer sheet is 10
６０60 μm (more preferably 15 to 40 μm), and the thickness of each layer is PP layer / adhesive resin layer / EVOH layer / adhesive resin layer = 8 μm or more (further 10 to 50 μm) /0.2 to 5 μm
m (further 0.3 to 2 μm) / 1 to 20 μm (further 1
-10 μm) /0.2-5 μm (further 0.3-2 μm)
The selection may be made from the range of m).

If the thickness of the sheet is less than 10 μm, the sheet may not be stiff and may be difficult to handle.
If it exceeds μm, the flexibility of the sheet tends to be insufficient. P
If the thickness of the P layer is less than 8 μm, the moisture resistance tends to be insufficient. If the thickness of the adhesive resin layer is less than 0.2 μm, EVOH
When the thickness exceeds 5 μm, the transparency of the sheet may decrease. EVOH layer thickness is 1μ
If it is less than m, the gas barrier property is insufficient, and if it exceeds 20 μm, the bending resistance of the sheet tends to deteriorate.

Thus, PP layer / adhesive resin layer / EVO
A stretched multi-layer sheet comprising an H layer / adhesive resin layer can be obtained. In the present invention, a heat seal layer is laminated on the surface of the adhesive resin of the stretched multi-layer sheet. Will be described.

The resin used for the heat sealing layer is not particularly limited as long as heat sealing is possible.
Ethylene-based polymer, propylene-based polymer, butene-based polymer, or a copolymer thereof, α-olefins having 3 to 10 carbon atoms containing ethylene as a main component, and 4 to 15 carbon atoms
Dienes, vinyl acetate, acrylates, methacrylates and the like, olefin-based polymers such as copolymers with one or more comonomers selected from the group consisting of:
Examples include polyester, polyamide, polyacrylonitrile, and the like. Among them, a non-stretched polypropylene resin (CPP) layer, an ethylene-butene-polypropylene copolymer resin layer or a linear low-density polyethylene resin (LLDPE) layer is preferably used. Polymerized LLDPE is also suitably used. Also,
The thickness of the heat seal layer is not particularly limited, but is preferably 5 μm or more (more preferably 10 to 80 μm) in order to prevent deformation of the laminate and the packaging bag.

Further, the melting point of the resin used for the heat seal layer is preferably 150 ° C. or less (more preferably 70 to 150 ° C.). If the melting point exceeds 150 ° C., the difference in melting point from the PP of the base material becomes small, so that the PP of the base material tends to shrink during heat sealing, and the appearance of a packaging bag may be deteriorated.

For lamination, a known method can be employed, for example, a method such as a dry lamination method, a polysand lamination method, or an extrusion lamination method. The dry lamination method is preferred in terms of the number of the adhesives, and known adhesives such as an organic titanium compound, an isocyanate compound, a polyester compound, and a polyurethane compound can be used.

It is also preferable to provide a printing layer between the adhesive resin layer and the heat sealing layer. The printing surface can be on either the side of the adhesive resin layer or the side of the heat seal layer. For printing, a known printing method and apparatus such as gravure printing, flexographic printing, screen printing, and ink can be used.

Thus, the desired laminate is obtained. In the present invention, the E
The orientation coefficient of the C—O group of the VOH layer by the polarized infrared dichroism method is −0.4 to −0.01 (furthermore, −0.3 to −0.05).
It is preferable that the orientation coefficient of such a CO group is-
If it is less than 0.4, the tear resistance of the laminate tends to decrease, and if it exceeds -0.01, the effect of improving the gas barrier properties by stretching tends to be insufficient, which is not preferable. The orientation coefficient (F) according to the polarized infrared two-color method can be determined by the following equation (1).

F = (1−D) / (1 + 2D)
(1) Here, F represents an orientation coefficient, D represents a dichroic ratio, and D =
In At / Am, At and Am further denote absorption peaks (1090) of the CO stretching vibration in the direction parallel to the stretching direction (Am) and the direction perpendicular to the stretching direction (At) in the IR absorption spectrum of the laminate.
cm ^-1 ). In calculating the absorbance, a line connecting the valleys of the peaks near 780 cm ^-1 and 1550 cm ^-1 with a straight line is determined as a baseline. Also,
Here, the stretching direction refers to the transverse direction (TD direction).

To adjust the orientation coefficient, EVOH
And the stretching conditions (stretching temperature, stretching speed, stretching ratio) and the like may be controlled. Among them, the ethylene content of the main component EVOH in the EVOH composition is 20 to 40 mol%, and the saponification degree is 98 mol%. As described above, a method in which the stretching ratio is 4 times or more is suitably used.

Thus, a laminate can be obtained by the method of the present invention. In the present invention, a semi-transparent layer is provided on the surface of the PP layer of the laminate in order to impart a light-shielding property and a high-grade feeling to the packaging bag. Provided, and the haze value of the laminate is 30% or more (further 4%).
(0 to 90%, particularly 50 to 80%). When the haze value is less than 30%, the light-shielding property is poor and the sense of quality is poor. Such a translucent layer is not particularly limited as long as the haze value of the laminate can be in the above range, and examples thereof include a block copolymer of PP-other component, a polyolefin such as LDPE, and a quinacridone derivative of the aforementioned PP. Special nucleating agents, inorganic fillers, etc.
Blends of a foaming agent and the like, and those obtained by mechanically embossing after obtaining a film using the above-mentioned PP can be used. Among them, ethylene-propylene block copolymer or ethylene-propylene copolymer can be used. A blend of a polymer and LDPE is preferably used.

The method for providing the translucent layer on the surface of the PP layer is not particularly limited, and a method of previously laminating on a multilayer sheet of the PP layer / adhesive resin layer / EVOH layer before stretching,
A method of laminating after obtaining a stretched multilayer sheet composed of P layer / adhesive resin layer / EVOH layer / adhesive resin layer,
A method of obtaining a laminate composed of a P layer / adhesive resin layer / EVOH layer / adhesive resin layer / heat seal layer and then laminating the laminate is exemplified. Although the thickness of the translucent layer is not particularly limited, in the finally obtained laminate, the total thickness of the translucent layer and the PP layer is 8 μm or more (further 10 to 50 μm).
μm) is preferable, and the thickness ratio between the translucent layer and the PP layer is
The ratio of 9/1 to 1/9 is preferable in terms of the balance between light-shielding properties, high-grade appearance, and economy.

The laminate thus obtained by the method of the present invention can be used for various packaging applications such as moisture-proof packaging, heat sterilization packaging, high-temperature packaging, pillow packaging, microwave packaging, PTP packaging, and bag-in-box for food and medicine. It is particularly useful as a packaging bag as an alternative film to the conventional vinylidene chloride coated polypropylene film (KOP), and the method of making and using such packaging bags is described.

For bag making, an ordinary bag making machine can be used, for example, a hot bar seal type or hot roll type bag making machine can be used, and a side seal type, a two-side seal type, and a three-side seal type can be used. It is used after processing into a bag such as a gasket seal type. In addition, an automatic bag making and filling machine such as a pillow package, a three-side seal package, and a four-side seal package that simultaneously perform bag making and filling can also be used.

The obtained packaging bag can be used as an alternative film to the conventional vinylidene chloride-coated polypropylene film (KOP) as an edible oil, an edible oil / fat product, a processed meat product, a processed marine product, a miso product requiring gas barrier properties and moisture-proof properties. ,
Pickles, various seasonings, spices, ketchup, mayonnaise,
Sauce, dressing, cheese, butter, jelly, curry roux, jam, soup, delicacy, confectionery, tea, coffee,
In addition to foods such as drinking water and alcohol, it is useful as a packaging bag for toiletries such as fragrances, toothpaste and detergents, cosmetics, perfumes, pharmaceuticals, agricultural chemicals, industrial fats and oils, industrial chemicals, etc. .

[0040]

The present invention will be specifically described below with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

Example 1 Polypropylene [melting point 1]
60 ° C., density 0.90 g / cm ³ , MI ³ g / 10 min (230 ° C., load 2160 g), amine antistatic agent 1
%), EVOH [Ethylene content 34 mol%, saponification degree 99.5 mol%, MI 8 g / 10 min (210 ° C., load 2160 g) 60 parts EVOH and ethylene content 38
Mol%, 99.5 mol% saponification degree, 15 parts of EVOH having MI of 8 g / 10 min (same as above) and EVOH25 having ethylene content of 44 mol%, saponification degree of 96.2 mol%, MI 6.5 g / 10 min (same as above) Parts of the molten mixture] and the adhesive resin [density 0.89 g / cm ³ , MI 4 g / 10 min (23
0 ° C, load 2160g), maleic anhydride concentration 0.05
%, A modified ethylene-propylene copolymer having an ethylene content of 3 mol%], PP / adhesive resin / EVOH
After obtaining a laminated sheet (thickness configuration is 600 μm / 32 μm / 160 μm), it is placed on a heating roll in the longitudinal direction (MD direction).
Stretched 5 times. Next, E of the obtained stretched laminated sheet
An adhesive resin (same as above) was laminated on the surface of the VOH layer using a single-layer T-die extrusion laminator at a speed of 80 m / min (thickness: 6.4 μm), and then at a speed of 9 m / min and a temperature of 1 m / min.
Stretched 8 times at 70 ° C., PP layer / adhesive resin layer / EV
OH layer / adhesive resin layer (thickness configuration is 15μm / 0.8μ
A stretched multilayer sheet having m / 4 μm / 0.8 μm and an orientation coefficient of the EVOH layer determined by a polarized infrared dichroism method of −0.03) was obtained.

A dry laminating adhesive [polyester two-component solvent type] was applied to the surface of the adhesive resin layer of the obtained stretched multilayer sheet at a solid content of 2 g / m ² , and dried to evaporate the solvent. Thereafter, a non-stretched film of an ethylene-butene-polypropylene copolymer [ethylene content 3%, butene content 2%] having a thickness of 20 μm is laminated on the applied surface by a dry lamination method to obtain a target laminate. Was. About the obtained laminated body, oxygen permeability (20 degreeC, 50% R
H) and water vapor permeability (measured at 40 ° C., 90% RH).

Further, using an automatic filling and bag making machine (horizontal pillow wrapping machine “FW3400” manufactured by Fujiki Kaisha Co., Ltd.), the ethylene temperature of the obtained laminate was set at 160 ° C. and 50 shots / min. Packaging bag of 20 cm length x 10 cm width using a butene-polypropylene copolymer layer as a seal layer (3-sided seal consisting of sticking on the mouth and back, no filling)
Was prepared.

With respect to such a packaging bag, the back-sticking strength (measured at a pulling speed of 200 mm / min at 23 ° C.) was measured. The state of the packaging bag was visually observed, and the appearance was evaluated as follows. ○ ・ ・ ・ No abnormality such as wrinkles was observed in both the mouth and back pastes, and the appearance was good △ ・ ・ ・ The laminated body curled during bag making and there were wrinkles in the back paste part, There is a slight problem in appearance ×: The laminate is curled during bag making, wrinkles are formed on the back part, and there are also parts where the laminate is heat-sealed with the curl. is there

Further, one side of the above-mentioned packaging bag was cut open, and 3 g of paradichlorobenzene (PDCB) was added thereto. The cut portion was heat-sealed and sealed, and then sealed in a 2 liter glass container. It was stored at 23 ° C. and its fragrance retention performance was evaluated as follows. ○ ・ ・ ・ The odor of PDCB was not detected in the glass container even after 2 months from the start of the test, and the scent retention performance was good △ ・ ・ ・ 1 month after the start of the test, the PD in the glass container
The scent of CB is leaking and the scent retention performance is poor. ×… One week after the start of the test, PD was placed in a glass container.
The scent of CB is leaking and the scent retention performance is extremely poor

Example 2 PP [same as in Example 1], EVOH [ethylene content 36 mol%, saponification degree 99.5 mol%, MI 4 g / 10 min (210 ° C.) , Load 2
160 g) of a melt mixture of 70 parts of EVOH, 47 mol% of ethylene content, 96.5 mol% of saponification degree, and 30 parts of EVOH having MI of 4.5 g / 10 min (same as above) and adhesive resin [same as in Example 1]. Supply, PP layer / adhesive resin layer / EVOH layer (thickness configuration is 600 μm / 32 μm / 1
After obtaining a laminated sheet (60 μm), the sheet was stretched 4 times in the machine direction (MD direction) on a heating roll. Next, an adhesive resin (same as in Example 1) was applied to the surface of the EVOH layer of the obtained stretched laminated sheet by using a single-layer T-die extrusion laminating apparatus.
After laminating (thickness: 6.4 μm) at a speed of 0 m / min to obtain a multilayer sheet, the speed is 12 m / min in the lateral direction (TD direction).
The film is stretched 10 times at a temperature of 170 ° C. to obtain a PP layer / adhesive resin layer / EVOH layer / adhesive resin layer (having a thickness of 15 μm /
A stretched multilayer sheet having a thickness of 0.8 μm / 4 μm / 0.8 μm and an orientation coefficient of the EVOH layer determined by a polarized infrared dichroism method of −0.07) was obtained.

An adhesive for dry lamination was applied to the surface of the adhesive resin layer of the obtained stretched multilayer sheet in the same manner as in Example 1, dried and evaporated to remove the solvent. Ethylene with a thickness of 20 μm by lamination
An unstretched film of a butene-polypropylene copolymer was laminated to obtain a desired laminate. The obtained laminate was measured for oxygen permeability and water vapor permeability in the same manner as in Example 1. Further, in the same manner as in Example 1, a packaging bag was prepared using an automatic filling bag-making machine, and the back pasting seal strength was measured. Further, the appearance and perfume retention performance of the packaging bag were similarly evaluated.

Example 3 In a multilayer T-die coextrusion film forming apparatus, PP [same as in Example 1], EVOH [ethylene content 34 mol%, saponification degree 99.5 mol%, MI 8 g / 10 min (210 ° C.) , Load 2
160 g) of a molten mixture of 80 parts of EVOH, 44 mol% of ethylene content, 96.2 mol% of saponification degree, and 20 parts of EVOH having MI of 6.5 g / 10 min (same as above) and an adhesive resin [same as in Example 1]. Supply, PP layer / adhesive resin layer / EVOH layer (thickness configuration is 600 μm / 42 μm / 1
After obtaining a laminated sheet having a thickness of 26 μm), it was stretched 6 times in the machine direction (MD direction) on a heating roll. Next, the adhesive resin [same as above] was applied to the EVOH layer surface of the obtained stretched laminated sheet for 80 m using a single-layer T-die extrusion laminating apparatus.
At a speed of 8 m / min in the transverse direction (TD direction) at a temperature of 168.
At 7 ° C., the PP layer / adhesive resin layer / EVOH
Layer / adhesive resin layer (thickness structure is 14μm / 1μm / 3μ
A stretched multilayer sheet having m / 1 μm and an orientation coefficient of the EVOH layer determined by a polarized infrared two-color method of −0.02) was obtained.

An adhesive for dry lamination [polyester two-component solvent type] is applied to the surface of the adhesive resin layer of the obtained stretched multilayer sheet at a solid content of 1.5 g / m ² , dried, and the solvent is evaporated. After that, a 40 μm-thick linear low-density polyethylene (L
(LDPE) was laminated to obtain a target laminate. The obtained laminate was measured for oxygen permeability and water vapor permeability in the same manner as in Example 1. In the same manner as in Example 1, using the LLDPE layer of the obtained laminated body as a sealing layer, a packaging bag of 25 cm (length) × 5 cm (width) (three-sided seal composed of mouth and back, no filling) was prepared. Then, the strength of the back-sticking seal was measured. Further, the appearance and fragrance retention performance of the packaging bag were similarly evaluated. However, about the evaluation of the fragrance retention performance, 3 g of camphor was sealed in place of 3 g of paradichlorobenzene.

Example 4 A multi-layer T-die co-extrusion film forming apparatus was prepared by adding PP [same as in Example 1], EVOH [ethylene content 29 mol%, saponification degree 99.7 mol%, MI 12 g / 10 min (210 ° C.) , A 2160 g load, 60 parts EVOH, an ethylene content of 36 mol%, a saponification degree of 99.5 mol%, and an MI of 8 g / 10 min (2
20 parts of EVOH (10 ° C., load 2160 g), ethylene content 42 mol%, degree of saponification 97.5 mol%, MI13
g / 10 minutes (same as above) and 20 parts of a molten mixture of EVOH] and an adhesive resin [same as in Example 1].
Adhesive resin layer / EVOH layer (thickness configuration is 800 μm / 5
(0 μm / 300 μm), and stretched 5 times in the machine direction (MD direction) on a heating roll. Next, an adhesive resin [same as above] is laminated (at a thickness of 10 μm) on the surface of the EVOH layer of the obtained stretched laminated sheet at a speed of 80 m / min using a single-layer T-die extrusion laminating apparatus. After obtaining, the speed 15m in the lateral direction (TD direction)
Per minute at a temperature of 172 ° C., and stretched 12 times to obtain a PP layer / adhesive resin layer / EVOH layer / adhesive resin layer (thickness configuration is 13
A stretched multilayer sheet having a thickness of μm / 0.8 μm / 5 μm / 0.8 μm and an orientation coefficient of the EVOH layer determined by a polarized infrared dichroism method of −0.08) was obtained.

An adhesive for dry lamination [polyester two-component solvent type] was applied to the surface of the adhesive resin layer of the obtained stretched multilayer sheet at a solid content of 2 g / m ² , and dried to evaporate the solvent. Thereafter, a non-stretched polypropylene film (CPP) having a thickness of 25 μm was laminated on the coated surface by a dry lamination method to obtain a target laminate. The obtained laminate was measured for oxygen permeability and water vapor permeability in the same manner as in Example 1. Also, in the same manner as in Example 1,
Using the CPP layer of the obtained laminate as a seal layer,
A wrapping bag measuring 3 cm in width and 5 cm in width (a three-sided seal consisting of a mouth-applied and a back-applied, no filling) was prepared, and the back-applied seal strength was measured. Further, the appearance and perfume retention performance of the packaging bag were similarly evaluated. However, the evaluation of the perfume retention performance was performed by sealing 10 g of green tea in place of 3 g of paradichlorobenzene.

Example 5 In Example 2, a multi-layer T-die co-extrusion film forming apparatus was used.
[Same as in Example 1], ethylene-propylene block copolymer (PE-PP) [melting point: 158 ° C, density: 0.91 g]
/ Cm ^3, MI6.5g / 10 min (230 ° C., load 21
60 g), ethylene content 25%], EVOH [same as in Example 2] and adhesive resin [same as in Example 1] to supply PE-PP layer / PP layer / adhesive resin layer / EVOH layer ( Thickness configuration is 80 / 520μm / 32μm / 160μ
m), except that a laminated sheet was obtained.
Layer / PP layer / adhesive resin layer / EVOH layer / adhesive resin layer (thickness configuration is 2 μm / 13 μm / 0.8 μm / 4 μm /
A stretched multilayer sheet having a thickness of 0.8 μm and an orientation coefficient of the EVOH layer determined by a polarization infrared dichroism method of −0.06) was obtained. Further, in the same manner as in Example 1, a non-stretched film of an ethylene-butene-polypropylene copolymer having a thickness of 20 μm was laminated to obtain a target laminate. In addition, the haze value of the obtained laminated body was 50%. The obtained laminate was measured for oxygen permeability and water vapor permeability in the same manner as in Example 1. Also,
When a packaging bag was produced using an automatic filling bag making machine in the same manner as in Example 1, the packaging bag exhibited excellent light-shielding properties and high-grade appearance. In addition, the strength of the sealing sticking on the back of the packaging bag,
Appearance and fragrance retention were similarly evaluated.

Example 6 In Example 3, a multi-layer T-die coextrusion film forming apparatus was used.
[Same as in Example 1], ethylene-propylene block copolymer (PE-PP) [melting point: 158 ° C, density: 0.91 g]
/ Cm ³ , MI 6.5 g / 10 min (230 ° C., load 21
60%), ethylene content 25%] 85% and low density polyethylene (LDPE) [melting point 113 ° C, density 0.925
g / cm ³ ] 15% molten mixture, EVOH [Example 3
And the adhesive resin [same as in Example 1] to supply (PE-PP + LDPE) layer / PP layer / adhesive resin layer / EVOH layer (thickness configuration is 90/510 μm / 42 μm).
m / 126 μm) (PE-PP + LDPE) layer / PP layer / adhesive resin layer / EVOH layer / adhesive resin layer (thickness is 2 μm / 1
A stretched multilayer sheet having a thickness of 2 μm / 1 μm / 3 μm / 1 μm and an orientation coefficient of the EVOH layer determined by a polarized infrared dichroism method of −0.02) was obtained. Further, in the same manner as in Example 3, an unstretched LLDPE film having a thickness of 40 μm was laminated to obtain a target laminate. In addition, the haze value of the obtained laminated body was 60%. The obtained laminate was measured for oxygen permeability and water vapor permeability in the same manner as in Example 1. Further, a packaging bag was produced using an automatic filling bag making machine in the same manner as in Example 3, and the packaging bag exhibited excellent light-shielding properties and high-grade appearance. Further, the backing seal strength, appearance and fragrance retention performance of the packaging bag were similarly evaluated.

Comparative Example 1 The same PP and E as in Example 1 were used in a multilayer T-die coextrusion film forming apparatus.
After supplying VOH and adhesive resin to obtain a multilayer sheet (thickness configuration is 600 μm / 32 μm / 160 μm / 32 μm) of PP layer / adhesive resin layer / EVOH layer / adhesive resin layer, After stretching 5 times in the machine direction (MD direction), the film is further stretched 8 times in the transverse direction (TD direction) at a temperature of 170 ° C. by a tenter method at a speed of 9 m / min and PP / adhesive resin / EVOH / adhesion Resin (thickness is 15μm /
A stretched multilayer sheet having a thickness of 0.8 μm / 4 μm / 0.8 μm and an orientation coefficient of the EVOH layer determined by a polarized infrared dichroism method of −0.03) was obtained. Evaluation was performed in the same manner as in Example 1 without providing a heat sealing layer on the obtained stretched multilayer sheet. However,
The production of the packaging bag was performed by heat-sealing the surfaces of the adhesive resin layers.

Table 1 shows the evaluation results of the examples and the comparative examples. [Table 1] Evaluation of laminated body Evaluation of packaging bag Oxygen permeability Water vapor permeability Seal strength Appearance Scent retention performance Example 1 3.7 5.4 2000 ○ ○ 〃 2 4.1 5.4 2000 ○ ○ 〃 3 4.7 4.4 4000 ○ ○ ４ 4 3.0 4.4 2700 ○ ○ ５ 5 4.1 5.4 2000 ○ ○ 〃 6 4.7 4.4 4000 ○ ○ Comparative Example 1 5.0 8.5 200 × × 1) Unit of oxygen permeability: cc / m ²・ day ・ atm 2) Unit of water vapor permeability: cc / m ²・ day 3) Unit of seal strength: g / 15mm

[0056]

Industrial Applicability The laminate of the present invention is excellent in gas barrier properties, moisture proof properties, fragrance retention properties, etc., and furthermore, when obtained as a packaging bag, has excellent sealing properties and excellent appearance. It is useful for various packaging applications, as well as food and pharmaceutical packaging bags.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B65D 65/40 B65D 65/40 D // B29K 23:00 B29K 23:00 B29L 7:00 B29L 7:00 9:00 9:00 (72) Inventor Motohiro Enoda 1 Kasamidate, Saijo, Daiji-cho, Kaifu-gun, Aichi Prefecture Inside Nagoya Plant of Nimura Chemical Industry Co., Ltd.

Claims (6)

[Claims] 1. A polypropylene (PP) layer / adhesive resin layer / a saponified ethylene-vinyl acetate copolymer (EVO)
H) In producing a laminate having a layer configuration of layer / adhesive resin layer / heat seal layer, polypropylene (P)
P), saponified ethylene-vinyl acetate copolymer (EVO
H) and the adhesive resin are coextruded to form a polypropylene (P
After obtaining a multilayer sheet having a layer configuration of P) layer / adhesive resin layer / saponified ethylene-vinyl acetate copolymer (EVOH) layer, the multilayer sheet is stretched at least in the extrusion direction (MD direction), Next, after laminating an adhesive resin layer on the surface of the saponified ethylene-vinyl acetate copolymer (EVOH) layer of the multilayer sheet, it is stretched in the width direction (TD direction), and further heat-sealed to the surface of the adhesive resin layer. A method for producing a laminate, comprising laminating layers. 2. An orientation coefficient of a CO group of a saponified ethylene-vinyl acetate copolymer (EVOH) layer measured by a polarized infrared dichroism method is -0.4 to -0.01. A method for manufacturing a laminate according to claim 1. 3. The saponified ethylene-vinyl acetate copolymer (EVOH) is composed of two saponified ethylene-vinyl acetate copolymers (EVOH), and the difference in ethylene content between each is 4 mol% or more and / or 3. The method according to claim 1, wherein a difference in saponification degree is 1 mol% or more. 4. The saponified ethylene-vinyl acetate copolymer (EVOH) comprises three or more kinds of saponified ethylene-vinyl acetate copolymers (EVOH), and the difference between the maximum value and the minimum value of the ethylene content is 4%. The method for producing a laminate according to any one of claims 1 to 3, wherein the difference between the maximum value and the minimum value of the degree of saponification is 1 mol% or more. 5. A laminate comprising a translucent layer provided outside the polypropylene (PP) layer, and a haze value of the laminate of 30%.
The method for producing a laminate according to any one of claims 1 to 4, wherein: 6. The method for producing a laminate according to claim 1, wherein the laminate is used for a packaging bag.