JPH0515183B2 - - Google Patents

Description

[Detailed Description of the Invention] A. Industrial Fields of Application The present invention provides a method of producing a material that exhibits less neck-in and good adhesion during extrusion molding, and a uniform thickness distribution and excellent gas barrier properties during extrusion lamination. Ethylene-vinyl alcohol copolymer (hereinafter referred to as
This is a laminate structure using EVOH), which is particularly suitable for food packaging.

B. Prior Art EVOH is now recognized to have considerable value in food packaging films, particularly those intended for use with food and other products requiring protection against oxygen. However, single-phase films made from EVOH lack toughness and are brittle, and the films do not exhibit effective barrier properties against water or water vapor.

To improve these drawbacks, EVOH resins are usually made of nylon, polyester, polypropylene,
It is in the form of a multilayer film made by laminating a structural layer containing one or more thermoplastic resins such as polyethylene or polyvinyl chloride, and various sealant layers such as ionomers and ethylene-vinyl acetate copolymers. It is used.

By the way, methods for obtaining multilayer laminates containing EVOH include dry laminating or polysand laminating a single-phase EVOH film onto other thermoplastic resins or paper, or conversely, extrusion lamination of EVOH onto paper or other thermoplastic resin films or sheets. Various methods have been adopted, such as a multilayer coextrusion lamination method containing EVOH. However, during the above three molding processes, the following problems occurred. That is, first of all, forming an EVOH single phase film and
During EVOH single layer extrusion lamination, EVOH resin is
After it is discharged from an extruder die, it tends to shrink more easily (neck-in) on both sides and in the width direction than other resins until it comes into contact with a cooling roll and solidifies.

As the width of the resulting film is shortened to a large width, it is necessary to make a large die to obtain the desired width of film. In addition, since both ends of the film are thick, the product becomes even narrower, and both ends have to be cut, which has the disadvantage of increasing loss.

Second, when extrusion laminating a single layer of EVOH to other thermoplastic films, sheets, or paper, the adhesion to the other films or sheets is insufficient;
Furthermore, when high viscosity EVOH was used to improve the above-mentioned netquin, the adhesion became increasingly poor.

Finally, due to recent technological advances, during extrusion lamination, rather than extruding a single EVOH layer, a method has been adopted in which EVOH and other thermoplastic resin are co-extruded and this is extruded into a thermoplastic resin layer. There is. However, even in that case, during coextrusion lamination,
It is often difficult to uniformly control the widthwise thickness distribution of the EVOH layer, resulting in many problems such as making the EVOH layer thicker than necessary and increasing loss at both ends.

Therefore, as a measure to improve netquin,
During film formation, methods have been used to suppress shrinkage by blowing air, etc. onto both ends of the resin discharged from the die, or by fixing only both ends with auxiliary rolls. Since the part is deformed, it is necessary to cut both ends, and there is a large loss, so no fundamental improvement has been achieved. Also
A method of cross-linking EVOH with a cross-linking agent to improve netuin has also been proposed (Japanese Patent Application Laid-Open No.
45848), NETSUQUIN is improved to some extent, but the film does not contain gel or
It was unusable due to the presence of a large amount of particles and the severe coloring.

On the other hand, as measures to improve the uneven thickness of the EVOH layer in the width direction during coextrusion lamination, methods include selecting brands of polyethylene, polypropylene, adhesive resins, etc. whose melt viscosity is close to EVOH, and methods by modifying the coextrusion equipment. However, regarding the former, EVOH and other resins essentially have different dependencies on annual shear rates, so even if the viscosity (melt index) is combined under a constant shear rate condition, the thickness distribution will be different. It is not possible to make any major improvements.
Furthermore, since the viscosity of polypropylene, polyethylene, adhesive resins, etc. is regulated, there is a problem in that the intended food packaging material cannot be obtained. On the other hand, a uniform EVOH layer can sometimes be obtained by modifying the extrusion equipment, but because the operating conditions are very narrow, the thickness distribution changes due to slight fluctuations in the discharge speed and temperature, resulting in stable production. In addition, changing the brand of resin requires extensive modification of the equipment itself, which not only requires a great deal of effort, time, and raw materials to establish conditions, but also reduces the accuracy of design calculations. At present, the level is extremely low, so when modifying or adding new equipment, it is necessary to invest a great deal of effort, time, and raw materials to establish the conditions again, which is a big problem.

Efforts have also been made to improve the thickness distribution by adding additives to EVOH;
-20345), the effect is not sufficient, and during long-term operation,
It tends to cause bumps, streaks, and uneven flow, making it unusable. Therefore, during extrusion molding, there is less build-up and adhesion is good, and when co-extruded laminating, the thickness distribution is uniform and gas barrier properties are excellent.
The development of EVOH compositions was highly desirable in terms of operability and cost.

C. Problems to be Solved by the Invention The present invention provides a modified product that is free from the above-mentioned drawbacks, has no unevenness between products and within a molded product, and therefore has no variation in the above-mentioned properties, and has an extremely high degree of uniformity. The purpose of this study is to obtain an extruded laminate structure using the silicon-containing EVOH.

D Means for Solving the Problems The present invention relates to EVOH obtained by saponifying a copolymer of vinyl acetate, ethylene, and an olefinic unsaturated monomer containing silicon in a specific molecule. and the following general formula (),
Saponification degree of vinyl acetate component obtained by saponifying one or more copolymers selected from silicon-containing olefinic unsaturated monomers represented by () and (): 95 mol% Above, ethylene content is 25 to 60 mol%, preferably 25 to 55 mol%, silicon content is 0.0005 to 0.2 mol%.
It is a laminate structure obtained by melt extruding EVOH onto a thermoplastic resin layer or paper.

E Effects of the Invention When forming a single-layer extrusion laminate or a coextrusion laminate of the EVOH layer, as mentioned above, there is a large amount of net-in during the forming process, insufficient adhesion during extrusion lamination, and furthermore, the coextrusion laminate At times, the thickness distribution of the EVOH layer is uneven, etc.
When using EVOH, which features gas barrier properties, operability and cost are major obstacles. Therefore, as a result of intensive study on the modification of EVOH, we found that silicon-containing
EVOH has greatly improved moldability compared to EVOH alone, the addition of plasticizers such as nylon, aromatic sulfonic acid amides, and aliphatic polyhydric alcohols, or modification with crosslinking agents such as peroxide and boric acid. In addition, it was found that the molded product had excellent gas barrier properties, particularly gas barrier properties at high temperatures, leading to the present invention. Further, according to the present invention, by melt-extrusion laminating silicon-containing EVOH onto a thermoplastic resin layer or paper, a laminate structure having excellent properties can be obtained efficiently and at low cost. This fact is also clear from the examples described in detail below.

As mentioned above, the reason why silicon-containing EVOH has unexpectedly good moldability is not for nothing, but low polymerization degree EVOH containing silicon compounds
This is thought to be due to partial and reversible crosslinking via the silicon compound.

In other words, regarding the netquin properties in EVOH single-phase film formation, EVOH containing silicon compounds has
It is presumed that the partial crosslinking effect between the silicon compound and the -OH group of EVOH increased the elasticity effect and improved the netquin. Although it is generally known that crosslinking a resin improves its network properties, crosslinking with a crosslinking agent causes local gelation and creates numerous fissures in the formed film, making it impractical for practical use. However, silicon compound-containing EVOH causes very little buildup, probably because the crosslinking is partial and reversible as described above.

In general, resins with low polymerization degree cause less build-up due to gelation, but those containing silicon compounds
EVOH is a collection of low-heavy substances (silicides and -OH
Possibly because the degree of polymerization is high in terms of apparent melt viscosity due to partial crosslinking with groups, there is very little buildup, and when comparing EVOH with the same melt viscosity,
It is surprising that compared to unmodified EVOH, silicon-containing EVOH has less fissures.

In addition, when extrusion laminating a single layer of EVOH onto other resin films or paper, the interlayer adhesion of the laminate product increases.In general, the lower the degree of polymerization, the lower the viscosity. It is known that the interlayer adhesion strength increases, probably due to the increased properties. However, there are problems such as the lower the degree of polymerization, the larger the net build-up or the difficulty in forming a stable film due to drawdown. However, silicon-containing
As mentioned above, EVOH has greatly improved monolayer film forming properties (netquin properties) and has a low degree of polymerization.
Perhaps because it is an aggregate of EVOH, it appears to be effective as a low polymerization degree resin in terms of adhesion, and it seems that the interlayer adhesion strength during extrusion lamination is greatly improved.

Furthermore, with regard to coextrusion lamination, which is a recent trend, the above two properties (adhesive strength and bonding properties) work very effectively and are advantageous in terms of operability and cost. Silicon-containing EVOH is very effective in improving the thickness distribution of the EVOH layer during coextrusion molding. In other words, polyethylene on at least one side of the EVOH layer,
When coextruding (laminating) multilayer laminates containing polypropylene, ionomers, ethylene-vinyl acetate copolymers, and other adhesive resins, use resins that have approximately the same viscosity (melt index) at low shear rates for each resin. However, the thickness distribution of the EVOH layer in the width direction becomes uneven. As a result, there were problems such as uneven appearance and a decrease in the gas barrier function of the EVOH layer. However, silicon-containing
When EVOH is used, there is no need for extensive modifications to the equipment, and a uniform thickness distribution can be obtained with good reproducibility. Although the cause of this is not obvious, silicon-containing
Due to the partially reversible crosslinking of EVOH, during melting, it acts uniquely as a low molecular weight resin in the high shear region, and on the other hand, as a high molecular weight resin in the low shear region. The viscosity-shear rate dependence and radiation stress characteristics match and EVOH
It is thought that this is because the thickness distribution of the layer (in the width direction) has become uniform.

F More detailed description of the invention The silicon-containing EVOH of the present invention has an ethylene content of 25 to 60 mol%, preferably 25 to 55 mol%, and the degree of saponification of the vinyl acetate component of the copolymer is
An ethylene content of 95 mol% or more is preferable, and if the ethylene content is less than 25 mol%, it is difficult to significantly improve the effect of improving humidity dependence of barrier properties against oxygen, etc. while maintaining good melt molding processability. On the other hand, if it exceeds 55 mol%, especially 60 mol%, the barrier properties against oxygen, etc. and fragrance retention properties, which are the characteristics of EVOH, will decrease. If the degree of saponification is less than 95 mol %, the barrier properties and oil resistance will deteriorate, making it impossible to maintain the original characteristics of EVOH and making it difficult to enjoy the effects of the present invention.

The silicon-containing olefinic unsaturated monomer used in the present invention is preferably one or two selected from the compounds represented by the following general formulas (), (), and (). be able to.

[However, here, n is 0 to 1, m is 0 to 2, R ¹ is a lower alkyl group, an aryl group, or a lower alkyl group having an aryl group, and R ² is a linear or branched chain having 1 to 40 carbon atoms. is an alkoxyl group, and the alkoxyl group may have an oxygen-containing substituent. R ³ is a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom or a lower alkyl group, R ⁵ is an alkylene group or a divalent organic residue in which chain carbon atoms are interconnected by oxygen or nitrogen, R ⁶ is a hydrogen atom, a halogen atom, a lower alkyl group, an aryl group, or a lower alkyl group having an aryl group,
R ⁷ is an alkoxyl group or an acyloxyl group (herein, the alkoxyl group or acyloxyl group may have a substituent having oxygen or nitrogen), and R ⁸ is a hydrogen atom, a halogen atom, a lower alkyl group, an aryl group, or , a lower alkyl group having an aryl group, R ⁹ is a lower alkyl group. ] More specifically, R ¹ is a lower alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a aryl group having 1 to 18 carbon atoms.
5 represents a lower alkyl group, R ⁴ represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms, and R ⁵ represents an alkylene group having 1 to 5 carbon atoms or a group in which chain carbon atoms are interconnected by oxygen or nitrogen. combined 2
^R6 represents a hydrogen atom, a halogen atom, a lower alkyl group having 1 to 5 carbon atoms, or a valent organic residue having 6 carbon atoms.
~18 aryl group, or a lower alkyl group having 1 to 5 carbon atoms having an aryl group having 6 to 18 carbon atoms, and R ⁷ is an alkoxyl or acyloxyl group having 1 to 40 carbon atoms (here, may have a substituent containing oxygen or nitrogen), and R ⁸ is a hydrogen atom, a halogen atom, a lower alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a C 6 to 18 aryl group. It represents a lower alkyl group having 1 to 5 carbon atoms and having a 6 to 18 aryl group, and ^R9 represents a lower alkyl group having 1 to 5 carbon atoms.

Examples of the silicon-containing olefinic unsaturated monomer represented by the general formula () include vinyltrimethoxysilane, vinylmethyldimethoxysilane, vinyldimethylmethoxysilane, vinyltriethoxysilane, vinylmethyldiethoxysilane, vinyldimethylethoxysilane, Allyltrimethoxysilane, allylmethyldimethoxysilane, allyldimethylmethoxysilane, allyltriethoxysilane, allyldimethylethoxysilane, vinyltris(β-methoxyethoxy)silane, vinylisobutyldimethoxysilane, vinylethyldimethoxysilane, vinylmethoxydibutoxysilane, Vinyldimethoxybutoxysilane, vinyltributoxysilane, vinylmethoxydihexyloxysilane, vinyldimethoxyhexyloxysilane, vinyltrihexyloxysilane, vinylmethoxydioctyloxysilane, vinyldimethoxyoctyloxysilane, vinyltrioctyloxysilane, vinylmethoxy Silauryloxysilane, vinyldimethoxylauryloxysilane, vinylmethoxydioleyloxysilane, vinyldimethoxyoleyloxysilane, general formula (Here, m is the same as above. X indicates 1 to 20)
Examples include polyethylene glycol derivatives of vinylmethoxysilane represented by the following, but vinyltrimethoxysilane is preferred from an economic standpoint.

The silicon-containing olefinic unsaturated monomer represented by the general formula () is 3-(meth)acrylamide-propyltrimethoxysilane 3-(meth)acrylamide-propyltriethoxysilane 3-(meth)acrylamide-propyltri(β-methoxyethoxy)silane 3-(meth)acrylamido-propyltri(N-methylaminoethoxy)silane 2-(meth)acrylamide-ethyltrimethoxysilane 1-(meth)acrylamide-methyltrimethoxysilane 2-(meth)acrylamido-2-methylpropyltrimethoxysilane 2-(meth)acrylamide-isopropyltrimethoxysilane (Meta) such as (R represents hydrogen or methyl group)
Acrylamide-linear or branched alkyltrialkoxysilane N-(2-(meth)acrylamide-ethyl)-
Aminopropyltrimethoxysilane CH ₂ = CRCONHCH ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ (3-(meth)acrylamido-propyl)-oxypropyltrimethoxysilane CH ₂ = CRCONH(CH ₂ ) ₃ O(CH ( _meth )acrylamide-nitrogen-containing or oxygen _- containing alkyltrialkoxysilane such as 2) 3Si( _OCH3 ) ₃ (R represents hydrogen or a methyl group) 3-(meth)acrylamide-propyltriacetoxysilane _CH2 = CRCONH(CH ₂ ) ₃ Si(OCOCH ₃ ) ₃ 2-(meth)acrylamide-ethyltriacetoxysilane CH ₂ = CRCONH(CH ₂ ) ₂ Si(OCOCH ₃ ) ₃ 4-(meth)acrylamide-butyltriacetoxysilane CH ₂ = CRCONH(CH ₂ ) ₄ Si(OCOCH ₃ ) ₃ 3-(meth)acrylamide-propyltripropionyloxysilane CH ₂ = CRCONH(CH ₂ ) ₃ Si(OCOCH ₂ CH ₃ ) ₃ 2-(meth)acrylamide- 2-Mepropyltriacetoxysilane N-( _2- (meth)acrylamido-ethyl)aminopropyltriacetoxysilane _CH2 = _{CRCONHCH2CH2NH} ( _CH2 ) _3Si ( _OCOCH3 ) ₃ (R represents hydrogen or methyl group) )
Acrylamide-alkyltriacyloxysilane, 3-(meth)acrylamide-propylisobutyldimethoxysilane 2-(meth)acrylamide-ethyldimethylmethoxysilane 3-(meth)acrylamide-propyloctylacetoxysilane 1-(meth)acrylamide-methylphenyldiacetoxysilane 3-(meth)acrylamide-propylbenzyldiethoxysilane 2-(meth)acrylamido-2-methylpropyl monochlorodimethoxysilane 2-(meth)acrylamido-2-methylpropylhydrodienemethoxysilane (Meth)acrylamido-alkyldi- or monoalkoxy or di- or monoacyloxysilane such as (R represents hydrogen or methyl group), 3-(N-methyl(meth)acrylamido)-propyltrimethoxysilane 2-(N-ethyl-(meth)acrylamide)-
Ethyltriacetoxysilane Examples include (N-alkyl-(meth)acrylamido)alkyltrialkoxy or triacetoxysilane such as (R represents hydrogen or a methyl group). Among these, 3-(meth)acrylamide-
Propyltrimethoxysilane and 3-(meth)
Acrylamido-propyltriacetoxysilane is relatively easy and inexpensive to produce industrially, and 2-(meth)acrylamido-2-methylpropyltrimethoxysilane and 2-(meth)acrylamido-2-methylpropyltriacetoxysilane is preferably used because the amide bond is extremely stable against acids or alkalis. Here, the modified silicon-containing EVOH obtained by copolymerizing the silicon-containing polymerizable monomer represented by the general formula () with vinyl acetate and ethylene and saponifying the resulting copolymer is obtained by the following general formula ().
Contains a copolymer unit shown in

(Here, R ³ , R ⁴ , R ⁵ , R ⁶ , and m are the same as above.
R ¹⁰ represents a hydroxyl group or a salt of the hydroxyl group represented by the general formula OM (M represents an alkali metal or NH ₄ ).

As the silicon-containing olefinic unsaturated monomer represented by the general formula (), vinyltriacetoxysilane Vinyltripropionyloxysilane isopropenyltriacetoxysilane Vinylisobutyldiacetoxysilane Vinylmethyldiacetoxysilane vinyl methylacetoxysilane vinyl phenyl diacetoxysilane Vinyl monochlorodiacetoxysilane vinyl monohydrodiene diacetoxysilane etc., but vinyltriacetoxysilane is preferred from an economic standpoint.

The copolymerization of the silicon-containing olefinic unsaturated monomer with vinyl acetate and ethylene is preferably carried out by solution polymerization in the presence of alcohol. As for the alcohol, lower alcohols such as methanol and ethanol are usually preferred industrially. Copolymerization can be carried out either batchwise or continuously. The ethylene content of EVOH is mainly determined by the vinyl acetate present in the copolymerization system and the amount of ethylene dissolved in the copolymerization system, and the latter mainly depends on the polymerization ethylene pressure and temperature. In some cases, the silicon content of the modified EVOH is primarily governed by the quantitative relationship between vinyl acetate and silicon-containing olefinically unsaturated monomers present in the system. It is well known that in the case of a batch method, the copolymer composition changes with the polymerization rate depending on the copolymerization reactivity ratio, but one or both monomers are In order to obtain a copolymer having a uniform copolymerization composition, it is more desirable to adopt a so-called semi-batch method of adding . An example of how to calculate the amount added in this case is RJ Hanna (RJ
Industrial and Engineering Chemistry
Engineering Chemistry) Vol.49, No.2, 208~
209 (1957). In the case of a continuous system, a completely mixed one-stage flow system reaction system in which the stirring mixing tank is used as a copolymerization reaction tank is most suitable, and in the case of a multi-stage flow system reaction system of two or more stages, the same method as above is used. For this reason, it is more preferable to carry out the reaction while adding monomers to the second and subsequent copolymerization tanks so that the monomer composition in each stage of the copolymerization tank is constant. As a polymerization initiator, 2,2'-azobis(4-methoxy-
2,4-dimethylvaleronitrile), 2,4,4
-Ntriles such as trimethylvaleronitrile, 2,2'-azobisisobutyronitrile, di-n-
Propyl-peroxycarbonate, bis-4-
Known radical initiation such as carbonates such as t-butylcyclohexyl peroxydicarbonate, bis-2-ethylhexyl peroxydicarbonate, peroxides such as acetylcyclohexane sulfonyl peroxide, benzoyl peroxide, lauroyl peroxide, etc. agent can be used. In particular, polymerization initiators with a shorter half-life are suitable for long-term continuous polymerization operations because they can almost completely or largely suppress the formation of gel-like substances that are insoluble in the polymerization system and are observed over time during copolymerization. used.

The copolymer obtained by polymerization is then subjected to a saponification reaction. The saponification reaction is advantageously carried out in a known manner, for example by using an alkaline catalyst, that is, usually in the form of an alcoholic solution of the copolymer, and the reaction is carried out by alcoholysis. In particular,
The most suitable method is the method disclosed in Japanese Patent No. 575889 and Japanese Patent No. 611557, which uses a tower reactor and removes methyl acetate, which is a by-product during the saponification reaction, from the top of the tower by blowing alcohol vapor into the bottom of the tower. Can be used.

As alkaline catalysts used for saponification reactions,
Alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alcoholates such as sodium methylate and potassium methylate, and the like are used. Among these, sodium hydroxide is industrially and economically advantageous. The saponification temperature is suitably selected from the range of 60 to 175°C. In particular, when using the tower type reactor, a temperature of 100°C or higher is preferable from the viewpoint of shortening the reaction time and the solubility of the silicon-containing EVOH in alcohols, although it is also related to the composition of the copolymer. .

In the saponification reaction, vinyl alkoxysilane units are also partially or highly saponified and converted into vinyl silanol units, their alkali salts, or their intercondensates. However, the general formula ()
The copolymer containing the monomer represented by is kept stable without decomposition of the amide bond of the silicon-containing polymerizable monomer unit in the saponification reaction using an alkaline catalyst. However, during the saponification reaction, the silicon-bonded alkoxyl group, carboxyl group, hydrogen, and halogen of the silicon-containing monomer unit represented by the general formula () are simultaneously partially or highly saponified and converted into hydroxyl groups or alkali salts of hydroxyl groups. Ru. Furthermore, some of these hydroxyl groups are
When drying the modified EVOH molding material obtained after the saponification reaction, these reactive groups may be bonded to each other under exchange conditions to form a siloxane bond.
This modification resulted in the formation of many siloxane bonds.
The thermal meltability of EVOH molding materials sometimes deteriorates, so in such cases, the content of silicon-containing monomers must be adjusted or the silicon-containing polymerizable monomer unit must be extremely stable against alkalis. It is desirable that the modified EVOH has a (meth)acrylamido-branched alkylsilane unit with high properties.

After the saponification reaction, known methods can be applied to isolate the modified EVOH molding material.
In particular, the method disclosed in Japanese Patent No. 725520 in which the polymer is precipitated into strands and the polymer is separated is preferably used. The precipitated and isolated EVOH molding material is washed with water by a known method, then subjected to a known heat stabilization treatment such as acid treatment, and dried. During the saponification reaction during the acid treatment, the silicon-bonded alkoxyl group, carboxyl group, hydrogen, and halogen are converted into an alkali salt of the hydroxyl group, resulting in a hydroxyl group.

The silicon-containing EVOH used in the present invention is extremely satisfactory from the viewpoint of improving the inherent properties of the EVOH resin and imparting properties compatible with other resins and processing methods. The modified EVOH suitable for each case can be obtained by changing the content of the polymer depending on the purpose. For example, as the ethylene content increases, the melt viscosity index of EVOH increases, and when composited with other resins with low melt viscosity indexes, the difference in melt viscosity becomes large and a phenomenon indicating melt viscosity inconsistency occurs. In such cases, using the modified EVOH resin molding material in which the melt viscosity index of the EVOH resin is lowered by the modification of the present invention while maintaining the composition, the melt viscosity can be improved. The modified EVOH of the present invention can eliminate inconsistencies, etc.
The usefulness of the molding material is extremely large, coupled with the uniformity of its modification. If the content of the silicon-containing monomer is too small, the modification effect will not be exhibited, and if it is too large, the degree of crosslinking will increase too much and heat infusibility will develop. The content is selected depending on the purpose, but 0.0005 to 0.2 mol%, especially 0.001
A range of 0.1 mol % is preferred. The silicon content herein refers to the amount (mol %) of the silicon-containing monomer in the silicon-containing monomer-vinyl acetate-ethylene copolymer.

As mentioned above, the silicon-containing EVOH resin used in the present invention can be used more satisfactorily for all conventional purposes, but it has new properties derived from its silicon-containing properties, such as aluminum foil. , improved adhesion with other resins, etc. can be advantageously utilized.

ASTMD-1238-T of EVOH used in the present invention
The melt viscosity index (nullt index) measured by
0.05/10g/10 minutes or longer, more preferably 0.05/10g/10 minutes, and especially 0.1 to 10g/10 minutes is suitable for various uses such as films, sheets, containers, etc., unstretched or at least uniaxially stretched. used.

The silicon-containing EVOH used in the present invention is an EVOH having a specific ethylene content and silicon content obtained by saponifying a copolymer of vinyl acetate, ethylene, and the above-mentioned specific silicon-containing olefinic unsaturated monomer. However, the copolymer may contain other third substances as copolymer components within a range that does not affect its properties. As the third substance, for example, α- having 3 or more carbon atoms
Examples include olefins, acrylic acid, methacrylic acid, and esters of these acids. Furthermore, ordinary EVOH may be blended with the silicon-containing EVOH to the extent that it does not impede the object of the present invention.

As mentioned above, in the present invention, silicon-containing
EVOH is used by laminating it with other thermoplastic resins or low-carbon resins, but in recent years, with the diversification of properties and higher quality required, two-layer or double-layer It is suitably used as a multilayer laminate structure having more than one layer.

Examples of thermoplastic resins include polyolefin resins (polyethylene, polypropylene), ethylene-carboxylic acid vinyl ester copolymers, ionomer resins, polystyrene resins, saturated polyester resins, polyamide resins, and polyvinyl chloride resins. It will be done. Of these, silicon content
From the point of view of combination with EVOH, polyolefin,
Ethylene-carboxylic acid vinyl ester copolymer is preferred. The layer structure of the laminate structure is, for example, polyethylene (hereinafter referred to as PE)/adhesive resin (hereinafter referred to as AD)/silicon-containing EVOH of the present invention (hereinafter referred to as Si-EVOH).
PE/AD/Si-EVOH/AD/PE, PE/AD/Si
-EVOH/AD/Polypropylene (hereinafter referred to as PP) PP/AD/Si-EVOH/AD/PP, PE/AD/
PP/AD/Si-EVOH/AD/PP, ionomer/Si-EVOH/AD/PP, ionomer/
AD/Si−EVOH/AD/PE, PE/AD/Si−
EVOH/AD/Paper, Ionomer/AD/Si-
EVOH/AD/Paper, PE/AD/Si-EVOH/Paper/
PE, ionomer/AD/Si-EVOH/AD/
Examples include PE/paper/PE, but are not particularly limited.

Polyethylene here refers to high-density PE, medium-density
The resin is not particularly limited as long as it is represented by PE, low-density PE linear low-density PE, etc., and also includes copolymers and blends with 20 mol% or less of other monomers.

Further, as the polypropylene, a homopolymer, a copolymer, or a blend of these or with other polymers, which is mainly composed of propylene, can be used. Suitable propylene polymers include isotactic polypropylene, crystalline propylene-ethylene copolymers, blends of polypropylene and propylene-ethylene copolymers or polyethylene, and blends of crystalline propylene copolymers and polyethylene. I can list things. The amount of ethylene units contained in the propylene polymer in the form of a copolymer or blend is preferably 20% by weight or less, particularly 10% by weight or less of the total weight.

Ionomers (ionically crosslinked olefin copolymers) are copolymers of olefins and unsaturated carboxylic acids, or other vinyl monomers, which are obtained by neutralizing with alkali metals, alkaline earth metals, or organic bases. Resins, such as Surlyns, commercially available from DuPont, USA.

In addition, the ethylene-carboxylic acid vinyl ester copolymer is an ethylene-carboxylic acid vinyl ester copolymer having an ethylene content of 60 to 99 mol%, preferably 75 to 98 mol%, and the carboxylic acid vinyl ester component is It is represented by the general formula CH ₂ =CH-OCOR, and R is a linear or branched alkyl group having 1 to 20 carbon atoms. Typical carboxylic acid vinyl esters include, for example, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl octate, and vinyl docadate, among which vinyl acetate is preferred.

The adhesive resin used for the adhesive layer varies depending on the type of resin laminated adjacent to the Si-EVOH, but for example, maleic anhydride graft modified PE,
Maleic anhydride graft modified PP, maleic anhydride graft modified ethylene-ethyl acrylate,
Examples include a mixture of one or more selected from ethylene-vinyl acetate copolymer, maleic anhydride graft-modified ethylene-vinyl acetate copolymer, etc., or a blend of these and Si-EVOH.
It is possible to select and use one of these.

When commercializing the laminate structure into containers, etc., it is economically important to reuse the laminate waste and rejected products generated during molding.
Blends of EVOH and other resins and/or adhesives to be laminated can be used alone or laminated with Si-EVOH or other thermoplastic resins.

In the present invention, extrusion lamination is a method of obtaining a laminate structure by directly contacting and solidifying molten (including semi-molten) silicon-containing EVOH on a base material (thermoplastic resin or paper).

In the present invention, the method of melt-extruding and laminating Si-EVOH includes a single-sided extrusion lamination method, a polysandra lamination method, a tandem extrusion lamination method, etc., but is not particularly limited. In addition, extrusion lamination may be performed circumferentially around a tube-shaped object. It is better to apply corona treatment or plasma treatment to the base material to be extrusion laminated to Si-EVOH, that is, the thermoplastic resin layer, and if even stronger adhesive strength is required, it is recommended to apply an anchor coating agent. It is valid.
There is also a method of extrusion laminating a multilayer melt obtained by coextruding Si-EVOH and a thermoplastic resin onto a thermoplastic resin layer or layer. Here, the thermoplastic resin used for co-pressing with Si-EVOH may be the same as the thermoplastic resin used for the extrusion lamination described above.

In order to obtain the strength and dimensional stability of the extruded laminate structure (film or sheet) obtained in this way, heat setting, humidity control anti-fog treatment, anti-static treatment, heat resistance treatment, etc. can be freely applied. .

The laminate structure of the present invention obtained in this way has no appearance defects such as bumps and streaks, has high interlayer adhesion, and not only greatly reduces loss due to neck-in and poor thickness distribution, but also It is extremely useful as a food packaging material because of its extremely good gas barrier properties.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto in any way.

In the examples, unless otherwise specified, parts or % indicate parts by weight or % by weight.

<Measurement of thickness distribution in the width direction of Si-EVOH during coextrusion lamination> In a feedblock type 3 type 4 layer coextrusion lamination device, PE/EVOH discharged from a die width 550 mm
AD/Si-EVOH/AD or ionomer/AD/
Extrusion lamination of Si-EVOH/AD on paper,
Measurements were performed on the obtained multilayer laminate. If the thickness of the EVOH layer in the center of the above sheet is Aμ, and the average thickness of 10cm left and right from the center is Bμ,
The thickness variation rate (X%) of the EVOH layer is X = ((B-
Defined as A)/A) x 100 (%).

P.E.
Polyethylene (Mitsui Polychemicals, Mirason 12) Ionomer (Mitsui Polychemicals, Surlyn 1605) AD Adhesive resin (Toyo Soda, Mersen 5420) EVOH Center thickness 15μ target <Measurement of netquin properties> Supply EVOH to a 40φ extruder and coat When forming an EVOH single layer film using a hanger type die (width 550 mm), a test was conducted under the following conditions. When the width of the obtained film is defined as Amm, the network characteristic (X%) is defined as X=(550-A)/550×100(%).

Die slip opening 0.7m/m Film take-up speed 10m/min Average film thickness 15μ Air gap (Note 1) 40cm Die temperature 220℃ (Note 1) Air gap is the distance from the die outlet to the point where the film contacts the cooling roll. (cm) <Melt index measurement> Using a melt indexer, temperature 190℃, 2160g
Shows the melt index value measured under load conditions. (JIS K-6760) Example 1 Continuous polymerization was carried out under the following conditions in order to obtain a silicon-containing ethylene-vinyl acetate copolymer in a polymerization tank with a capacity of 10 and equipped with a stirrer and internally equipped with a cooling coil.

Vinyl acetate supply rate 480g/hr Methanol supply rate 40g/hr Vinyl-tri-methoxysilane supply rate 355mg/hr 2,2'-azobisisobutyronitrile 33mg/hr Polymerization temperature 77℃ Polymerization tank ethylene pressure 60Kg/cm ² G Average residence time 6hrs The polymerization rate of vinyl acetate was about 50%. The copolymerization reaction liquid was supplied to a purging tower, and unreacted vinyl acetate was removed from the top of the tower by introducing methanol vapor from the bottom of the tower, to obtain a 45% methanol solution of the copolymer. According to the magnetic resonance analysis, the copolymer contains 0.027 mol% of vinyltrimethoxysilane units, 59.5 mol% of vinyl acetate units, and approximately 59.5 mol% of ethylene units.
It was confirmed that the content was 4.05 mol%. A methanol solution of the copolymer was introduced into a tower-type saponification reactor, and sodium hydroxide was further supplied to the reactor at a molar ratio of 0.05 to the vinyl acetate component contained in the copolymer. Methanol vapor is blown into the tower to remove by-product methyl acetate from the top of the tower, and a saponification reaction is carried out, resulting in reforming from the bottom of the tower.
A methanol solution of EVOH was obtained. Mixed steam with a weight ratio of methanol/water = 7/3 was blown into the methanol solution to change the solvent composition in the solution to a water/methanol mixed system, and then discharged in the form of a strand into a 10% aqueous methanol solution at 5°C. The EVOH was isolated as a pellet by coagulation, precipitation, and cutting. After thoroughly washing with water, immerse it in dilute acetic acid water.
Dry at 65°C to 110°C. Saponification degree is 99.3 mol%
It was hot.

The EVOH (MI2.1g/10min) was supplied to a 40φ extruder, and the die temperature was adjusted using a coat hanger type die.
When forming a film at 220°C, an anchor coating treatment (Toyo Morton AT335A) was applied along the cooling roll of the discharged and molten film. The EVOH layer and the polyethylene layer were crimped together under a linear pressure of 7 Kg/cm, a take-up speed of 50 m/min, and a clearance of 10 cm between the die and the roll, and extrusion lamination of Si-EVOH was carried out. The net-in properties of the Si-EVOH layer of the obtained film were as good as 7%. Also, the adhesive strength between polyethylene and Si-EVOH is 450g/
It was 15mm wide, and the polyethylene layer was destroyed when peeled off.

This film was heated at 20℃-100%RH and at 20℃-65
After conditioning the humidity at %RH for 3 days, each sample was run on a Mocon oxygen permeation meter to measure the amount of oxygen permeation, and the amount of oxygen permeation through the EVOH layer was 1.0cc/20μ/
^m2・24hr・atm (20℃−65%RH), 13c.c.・20μ/
^m2・24hr・atm (20°C-100%RH), showing very good gas barrier properties.

Comparative Example 1 The same procedure as Example 1 was carried out except that vinyltrimethoxysila was not used, and the ethylene content was 40.7.
EVOH with a saponification degree of 99.4 mol% was obtained. Extrusion lamination was carried out in the same manner as in Example 1 using this EVOH. As a result, the netquin properties were as high as 40-60% and varied widely, making it difficult to collect the product. The oxygen permeation amount was measured in the same manner as in Example 1. 12c.c.・20μ/m ²・24hr・atm (20
℃-65%RH), 28c.c.・20μ/ ^m2・24hr・atm(20
℃−100%RH).

Comparative Example 2 Based on 100 parts by weight of EVOH used in Comparative Example 1
0.35 parts by weight of BPO was blended and crosslinked into a belet using a 40φ extruder at 320°C. The obtained pellets
After drying at 100°C for 5 hours, the melt index (hereinafter referred to as MI) was measured and found to be 1.8 g/10 minutes. Using this pellet, extrusion lamination was carried out in the same manner as in Example 1. As a result, the network properties were relatively good at 12%, but there were many fissures from the start of film formation, and even worse, streaks, spots, and uneven flow increased significantly 1 to 1.5 hours after the start of film formation. Moreover, the film was colored yellow, which was unbearable as a product.

Example 2 Using the same polymerization tank as in Example 1, continuous polymerization was carried out under the conditions shown below.

Vinyl acetate supply rate 60g/hr t-Butanol supply rate 440g/hr 2,2'-azobis-(2,4-dimethylvaleronitrile 110mg/hr 3-acrylamide-propyltrimethoxysilane 150mg/hr Polymerization temperature 60℃ Average retention Time: 8 hrs Polymerization tank ethylene pressure: 46 Kg/cm ² G The polymerization rate of vinyl acetate was approximately 55%.The copolymer was determined by nuclear magnetic resonance analysis to contain 0.013 mol% of 3-acrylamide-propyltrimethoxysilane units and acetic acid. It was confirmed that it contained 65 mol% of vinyl units and about 35 mol% of ethylene units.

After saponification and isolation in the same manner as in Example 1, post-treatment, and drying, modified EVOH was obtained. The degree of saponification was 99.2 mol%, and the MI ₁₉₀ was 0.7 g/10 min.

The EVOH was extrusion laminated in the same manner as in Example 1. The net-in characteristic value of the EVOH layer of the obtained film was good at 6%, and the average number of fixation eyes during 24-hour continuous operation was 0.4 pieces/1000cm ²
(The number of fisheyes in a 31 cm square film was measured, and the average value of n=5 is shown.) The film was of good quality. In addition, when the oxygen permeation amount was measured in the same manner as in Example 1, it was found to be 0.6cc・20μ/m ²・24hr・atm
(20℃-65%RH), 21c.c.・20μ/ ^m2・24hr・atm
(20°C - 100% RH), the film was in good condition.

Comparative Example 3 The same procedure as Example 2 was carried out except that 3-acrylamide-propyltrimethoxysilane was not used, and the ethylene content was 35 mol%, the degree of saponification was 99.3 mol%, and MI ₁₉₀ had an EVOH of 2.1 g/10 min. Obtained. Extrusion lamination was carried out in the same manner as in Example 2, and the net-in characteristic value of the obtained film was as high as 32%, with large fluctuations. Also, after 2 to 3 hours of continuous operation,
The appearance of streaks, etc. was noticeable. After 24 hours of operation, the film had an average of 10.5 eyes/ ^1000cm2 . In addition, when we measured the amount of oxygen permeation, we found that it was 0.5cc.
20μ/m ²・24hr・atm (20℃−65%RH), 38c.c.・
The temperature was 20 μ/m ²・24 hr・arm (20℃−100%RH).

Example 3 In Example 2, acrylamide-propyltriacetoxysilane was used as the silicon-containing monomer.
The same procedure as in Example 2 was carried out except that 290 mg/hr was used. It was confirmed by nuclear magnetic resonance analysis that the polymer contained 0.02 mol% of 3-acrylamide-propyltriacetoxysilane units, and had almost the same composition as in Example 2 regarding vinyl acetate and ethylene. The degree of saponification of the modified EVOH was 99.5 mol%, and the MI ₁₉₀ was 0.3 g/10 minutes.

When extrusion laminating the Si-EVOH in the same manner as in Example 1, a 60 μm polyethylene film treated with anchor coating (Toyo Morton AT335A) was guided along the cooling roll. The EVOH layer and the polyethylene layer were crimped together using a Nipprol linear pressure of 7 kg/cm, and extrusion lamination of SiEVOH was carried out. The pressure roll temperature was 70°C. The net-in characteristic value of the EVOH layer of the obtained extruded laminated multilayer film was 7%. Furthermore, the adhesive strength between polyethylene and SiEVOH was 400 g/15 cm width, and the polyethylene layer was destroyed during peeling. The oxygen permeation rate of this film is 0.6cc・20μ/
^m2・24hr・atm (20℃−65%RH), which was very good.

Comparative Example 4 The same procedure as Example 3 was carried out except that 3-acrylamide-propyltrimethoxysilane was not used, and the ethylene content was 34.5 mol% and the degree of saponification was 99.5.
Mol% MI ₁₉₀ yielded EVOH of 1.9 g/10 min. Extrusion lamination was carried out in the same manner as in Example 3. The net-in characteristic value of the EVOH layer of the obtained extruded laminate film was as large as 24%, and after 3 to 4 hours of film formation, streaks appeared on the entire extruded laminate film, probably due to the occurrence of bumps and streaks in the EVOH layer. was extremely difficult. The interlayer adhesion strength of the obtained multilayer film was as low as 100 to 150 g/15 cm width, and
No breakage or breakage of the polyethylene layer was observed during peeling. On the other hand, the oxygen permeation rate of this film is
It was 0.6cc・20μ/m ²・24hr・atm (20℃−65%RH).

Comparative Example 5 Extrusion lamination was carried out in the same manner as in Example 3 using the BPO crosslinked EVOH used in Comparative Example 2. As a result, the net-in characteristic value of the EVOH layer of the obtained multilayer film was 13%, which was relatively good.
Bumps in the EVOH layer begin to appear after 2 to 3 hours. Possibly due to streaks and uneven flow, streaks were likely to occur throughout the extruded laminate film, causing problems in operability. In addition, the PE layer of the film
The adhesive strength with the EVOH layer is low at 100g/15cm width.
There is concern that problems due to delamination will occur frequently in practice.

Example 4 In Example 2, the ethylene pressure in the polymerization tank was set to 35 kg/
cm ² G, vinyltriethoxysilane was used as the silicon-containing olefinic unsaturated monomer, and the same procedure was carried out except that the feed rate was 100 mg/hr. The obtained copolymer contains vinyltriethoxysilane units.
It contained 0.008 mol%, 75 mol% of vinyl acetate units, and about 28 mol% of ethylene units. Modified EVOH was obtained according to Example 2. The degree of saponification is
The melt viscosity index MI ₂₁₀ measured at 210° C. and a load of 2160 g was 0.8 g/10 min.

When forming a single layer film of the SiEVOH in the same manner as in Example 1, corona-treated polyethylene and polypropylene were placed on the cooling roll and the nip roll, respectively, and the nip roll was subjected to a linear pressure of 7 kg/cm.
Sandwich extrusion lamination of SiEVOH was carried out. The pressure roll temperature was 30°C.

The resulting laminate film had a netquin characteristic value of 5% and an interlayer adhesion of 300g/15mm.
Width (between PE and EVOH), 250g/15mm width (PP,
between EVOH). Furthermore, even after continuous operation for 24 hours, this laminate film had very few spots and streaks and had good operability (the film had 1.1 spots/1000 cm ² ).
The oxygen permeation rate of this film is 0.7cc・20μ/ ^m2・
It was good for 24 hours atm (20℃-65%RH).

Comparative Example 6 The same procedure as Example 4 was carried out except that vinyltriethoxysilane was not used. The netquin characteristic value of the EVOH layer of the obtained sand German thyrolaminated film was as large as 25%, and since both ends of the EVOH layer in the width direction were thickened by netquin, the linear pressure of the nipprol was increased from 7 to 14 kg/cm. It is necessary to increase the width, and due to the thickness of both ends, resin scum of EVOH resin is generated at both ends, causing increase and fluctuation of roll rotation torque.
Due to uneven lengths in the width direction of both ends of the EVOH layer and non-uniform appearance, the loss area increased even further. Even worse is the EVOH layer gel,
Bumps and streaks appeared frequently after 2 to 3 hours, and streaks tended to occur throughout the film, resulting in very poor operability.

In addition, when the interlayer adhesive strength of the multilayer film was measured, it was found that 90 g/15 cm width (between PE and EVOH), 50 g/15
It was found that there was almost no adhesion with the cm width (between PP and EVOH). On the other hand, the oxygen permeation rate of this film was 0.7cc・20μ/ ^m2・24hr・atm (20℃−
65%RH).

Example 5 Batch polymerization was carried out under the conditions shown below in order to obtain a silicon-containing ethylene-vinyl acetate copolymer in a polymerization tank with a capacity of 50 mm and equipped with a stirrer and a cooling coil inside.

Vinyl acetate amount 15Kg Methanol amount 5.8Kg Vinyltrimethoxysilane amount 6.4g 2,2'-Azobisisobutyronitrile amount
2.7g Polymerization temperature 60°C Polymerization tank ethylene pressure 36Kg/cm ² G Polymerization time 6.5hr The polymerization rate of vinyl acetate was 33%. It was confirmed by nuclear magnetic resonance analysis that the copolymer contained 0.02 mol% of vinyltrimethoxysilane units, 68 mol% of vinyl acetate units, and 32 mol% of ethylene units. The product was saponified, isolated and post-treated in the same manner as in Example 1, and then dried to obtain modified EVOH.
The degree of saponification was 99.5 mol%, and the MI ₁₉₀ was 0.55 g/10 minutes.

The EVOH, polyethylene (Mitsui Polychemical Mirason 12), and adhesive resin (Toyo Soda Mersen M5420) are fed to a 3 type 4 layer coextrusion (feedblock type die) film forming machine to produce PE/AD/
A film with SiEVOH/AD configuration was discharged.
The thickness of the PE layer is 60μ, the thickness of each adhesive layer is 30μ,
The thickness of the EVOH layer was 15μ. This ejected film is guided by corona-treated paper, and the above multilayer film is extruded and laminated on the paper at a Nipprol linear pressure of 12 kg/cm and a take-up speed of 10 m/min.The resulting structure is PE/AD/SiEVOH/ It became an AD paper.

The netquin properties of the EVOH layer of this sheet are 7
%, and the thickness distribution of the EVOH layer in the width direction was 6%, making it a uniform multilayered product with very high yield.
In addition, even after continuous operation for 24 hours, there was little occurrence of gel or fisheye (Fisheye 1.2
When the oxygen permeability of EVOH was measured, it was found to be 0.6cc/20μ/ ^m2 /24hr/atm (20° ^C -65%RH).

Comparative Example 7 The same procedure as in Example 5 was carried out except that vinyltrimethoxysilane was not used, and EVOH was obtained with an ethylene content of 31.8 mol%, a saponification degree of 99.6 mol%, and an MI ₁₉₀ of 5.1 g/10 min. Example 5 using this EVOH
Coextrusion lamination onto paper was carried out in the same manner as in . The netquin properties of the EVOH layer of the obtained sheet are 24
%, and the thickness distribution of the EVOH layer in the width direction was extremely non-uniform at 89%. 2 more~
After 3 hours of operation, gels and spots began to appear on the EVOH layer (9.6 pieces/1000cm ² ).
The amount of oxygen permeation through the EVOH layer is 0.7cc・20μ/ ^m2・24hr・
ATM (20℃-65%RH) was good.

Comparative Example 8 15 parts by weight of N-ethyltoluenesulfonic acid amide was added to 100 parts by weight of EVOH used in Comparative Example 7, and the mixture was mixed into pellets using a 40φ extruder. Extrusion lamination onto paper was carried out in the same manner as in Example 5 using pellets dried at 105°C for 16 hours. The thickness distribution of the EVOH layer in the width direction of the obtained sheet was 18%, which is a slight improvement.
The netquin characteristic value of the EVOH layer was significantly worse at 31%. In addition, there is a lot of gel (Fitsushi Eye)
7.1 pieces/1000cm ² ), and even worse, the oxygen permeation rate of the EVOH layer is 1.8cc・20μ/m ²・24hr・atm (20℃−
65%RH).

Comparative Example 9 Using the EVOH used in Comparative Example 2, extrusion lamination on paper was carried out in the same manner as in Example 5. The net-in properties of the EVOH layer of the obtained sheet were relatively good at 9%, but the thickness distribution of the EVOH layer in the width direction was uneven at 45%. In addition, spots were noticeable from the beginning of operation, and 2 to 3 hours after the start of operation, uneven flow and streaks occurred frequently, making it unbearable as a product (more than 100 spots/1000 cm ² ).

Example 6 Using the same polymerization tank as in Example 1, continuous polymerization was carried out under the conditions shown below.

Vinyl acetate supply rate 400g/hr Methanol supply rate 100g/hr Vinyltrimethoxysilane 240mg/hr 2,2'-azobis-(2,4-dimethylvaleronitrile) 170mg/hr Polymerization temperature 60℃ Average residence time 5hr Polymerization tank ethylene Pressure: 46 Kg/cm ² G Polymerization rate of vinyl acetate was approximately 45%. Nuclear magnetic resonance analysis revealed that the copolymer contained 0.023 mol% of vinyltrimethoxysilane units and 0.023 mol% of vinyl acetate units.
It was confirmed that it contained 61 mol% and about 39 mol% of ethylene units.

After saponification, isolation, and post-treatment in the same manner as in Example 1, the product was dried to obtain modified EVOH. The degree of saponification was 99.4 mol% and the MI ₁₉₀ was 1.5 min/10 min.

Extrusion lamination to paper was carried out in the same manner as in Example 5, except that the polyethylene was replaced with ionomer (Mitsui Polychemical Surlyn 1605). The netquin properties of the EVOH layer of the obtained sheet were 6%,
And the thickness distribution of the EVOH layer in the width direction is 7%,
And after 24 hours of operation, the number of fish eyes is 1.7/
1000cm ² , and the sheet had very good operability as well. In addition, the amount of oxygen permeation through the EVOH layer is 0.8cc.
It was good at 20μ/ ^m2・24hr・atm (20℃−65%RH).

Comparative Example 10 A paper extrusion laminate sheet was obtained in the same manner as in Example 6 except that vinyltrimethoxysilane was not used. The C ₂ H ₄ cort of EVOH was 39 mol%, the degree of saponification was 99.4 mol%, and the MI was 4.5 g/10 min. The netquin properties of the EVOH layer of this sheet are
18%, and the thickness distribution of the EVOH layer in the width direction was 29%, which was very poor, and uneven flow occurred after 2 to 3 hours (Fisheye was 15%).
pieces/1000cm ² ) The amount of oxygen permeation through the EVOH layer is 0.7cc・
The temperature was 20μ/ ^m2・24hr・atm (20℃−65%RH).

Comparative Example 11 After saponifying the EVOH used in Comparative Example 10, 0.020% boric acid was added to the EVOH solution, and post-treatment was carried out in the same manner as in Example 6. MI1.4 of obtained EVOH
g/10 minutes. Using the boric acid crosslinked EVOH,
Extrusion lamination onto paper was carried out in the same manner as in Example 6. The net-in properties of the EVOH layer of the obtained sheet were 21%, and the thickness distribution of the EVOH layer in the width direction was 21%, so the problem could not be solved. Therefore, boric acid crosslinked EVOH seems to have essentially different effects and effects from silicon-containing EVOH, and silicon-containing
It can be seen that only EVOH exhibits unique formability.

Claims (1)

[Claims] 1 Vinyl acetate, ethylene and the following general formula (),
Saponification degree of vinyl acetate component obtained by saponifying one or more copolymers selected from silicon-containing olefinic unsaturated monomers represented by () and (): 95 mol% A laminate structure obtained by melt-extruding a saponified silicon-containing ethylene-vinyl acetate copolymer having an ethylene content of 25 to 60 mol% and a silicon content of 0.0005 to 0.2 mol% onto a thermoplastic resin layer or paper. [However, here, n is 0 to 1, m is 0 to 2, R ¹ is a lower alkyl group, an aryl group, or a lower alkyl group having an aryl group, R ² is an alkoxy group having 1 to 40 carbon atoms, The alkoxyl group may have an oxygen-containing substituent. R ³ is a hydrogen atom or a methyl group, R ⁴ is a hydrogen atom or a lower alkyl group, R ⁵ is an alkylene group or a divalent organic residue in which chain carbon atoms are interconnected by oxygen or nitrogen, R ⁶ is a hydrogen atom, a halogen atom, a lower ^alkyl group, an aryl group or a lower alkyl group having an aryl group; ), R ⁸ is a hydrogen atom,
A halogen atom, a lower alkyl group, an aryl group or a lower alkyl group having an aryl group, R ⁹ is a lower alkyl group. 2. The laminate structure according to claim 1, obtained by extruding a multilayer melt obtained by coextruding a saponified silicon-containing ethylene-vinyl acetate copolymer and a thermoplastic resin into a thermoplastic resin layer or layer.