JP7002935B2 - Manufacturing method of gas barrier laminate - Google Patents

Description

The present invention relates to a method for producing a gas barrier laminate.

Generally, as a gas barrier material, a laminate in which an inorganic material layer, which is a gas barrier layer, is provided on a base material layer is used.
However, this inorganic layer is vulnerable to friction and the like, and such a gas barrier laminate has a gas barrier property due to cracks in the inorganic layer due to rubbing and elongation during post-processing printing, laminating, or filling of contents. May decrease.
Therefore, as a gas barrier material, a laminate using an organic layer as a gas barrier layer is also used.

As a gas barrier material using an organic layer as a gas barrier layer, a laminate having a gas barrier layer formed of a mixture containing a polycarboxylic acid and a polyamine compound is known.
Examples of the technique relating to such a gas barrier laminate include those described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-225940) and Patent Document 2 (Japanese Patent Laid-Open No. 2013-10857).

Patent Document 1 discloses a gas barrier film having a gas barrier layer formed of a polycarboxylic acid and a polyamine and / or a polyol, and having a degree of cross-linking of the polycarboxylic acid of 40% or more.
Patent Document 1 describes that such a gas barrier film has excellent gas barrier properties even under high humidity conditions as well as under low humidity conditions.

In Patent Document 2, polyamine and polycarboxylic acid are added to at least one surface of a base material made of a plastic film in a weight ratio of polyamine / polycarboxylic acid = 12.5 / 87.5 to 27.5 / 72.5. A film coated with a mixture thereof is disclosed.
Patent Document 2 describes that such a gas barrier film is excellent in gas barrier property, particularly oxygen blocking property, and also excellent in flexibility, transparency, moisture resistance, chemical resistance and the like even after boiling treatment.

Japanese Unexamined Patent Publication No. 2005-225940 Japanese Unexamined Patent Publication No. 2013-10857

According to the studies by the present inventors, the gas barrier film as described in Patent Documents 1 and 2 requires high temperature and long-term heating in order to crosslink the polycarboxylic acid and the polyamine. It became clear that there was still room for improvement in terms of productivity.

The present invention has been made in view of the above circumstances, and provides a production method capable of efficiently producing a gas barrier laminate having an amide crosslinked structure formed of a polyamine compound and a polycarboxylic acid, which is excellent in gas barrier performance. It is something to do.

The present inventors have conducted extensive research in order to achieve the above-mentioned problems. As a result, by heating the mixture containing the polycarboxylic acid and the polyamine compound by a specific heating means, the dehydration condensation reaction between the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound efficiently occurs. The present invention has been completed based on the finding that a gas barrier laminate having an amide crosslinked structure formed of a polyamine compound and a polycarboxylic acid, which has excellent gas barrier performance, can be efficiently produced.

That is, according to the present invention, the following method for producing a gas barrier laminate is provided.

[1]
A method for producing a gas barrier laminate comprising a substrate layer and a gas barrier polymer layer provided on at least one surface of the substrate layer.
A step of applying a mixture containing a polycarboxylic acid and a polyamine compound to a base material layer to obtain a coated layer, and
The coating layer is heated by a heating means, and the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound are dehydrated and condensed to form a gas barrier polymer layer having an amide bond. Process and
Including
A method for producing a gas barrier laminate, wherein the heating means includes at least one selected from a conduction heat transfer method and a radiant heat transfer method.
[2]
The method for producing a gas barrier laminate according to the above [1], wherein the heating means includes at least one selected from conduction heat transfer by a heating roll and radiant heat transfer by infrared rays.
[3]
The method for producing a gas barrier laminate according to the above [1] or [2], wherein the heating means further includes a convection heat transfer method.
[4]
In the step of forming the gas barrier polymer layer,
In the infrared absorption spectrum of the obtained gas barrier polymer layer,
The total peak area in the range of absorption band 1493 cm ^-1 or more and 1780 cm ^-1 or less is defined as A.
When the total peak area in the range of absorption band 1598 cm ^-1 or more and 1690 cm ^-1 or less is B.
The method for producing a gas barrier laminate according to any one of the above [1] to [3], wherein heating is performed until the area ratio of the amide bond represented by B / A becomes 0.330 or more.
[5]
(Number of moles of -COO- group contained in the above polycarboxylic acid in the above mixture) / (Number of moles of amino group contained in the above polyamine compound in the above mixture) = 100/22 or more and 100/99 or less. The method for producing a gas barrier laminate according to any one of the above [1] to [4].
[6]
Any one of the above [1] to [5], wherein the polycarboxylic acid contains one or more polymers selected from polyacrylic acid, polymethacrylic acid, and a copolymer of acrylic acid and methacrylic acid. The method for producing a gas barrier laminate according to the above.
[7]
The method for producing a gas barrier laminate according to any one of the above [1] to [6], wherein the polyamine compound contains polyethyleneimine.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a production method capable of efficiently producing a gas barrier laminate having an amide crosslinked structure formed of a polyamine compound and a polycarboxylic acid, which is excellent in gas barrier performance.

The above-mentioned objectives and other objectives, features and advantages are further clarified by the preferred embodiments described below and the accompanying drawings below.

It is sectional drawing which shows typically an example of the structure of the gas barrier laminated body of embodiment which concerns on this invention. It is sectional drawing which shows typically an example of the structure of the gas barrier laminated body of embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The figure is a schematic view and does not match the actual dimensional ratio. Unless otherwise specified, the "~" between the numbers in the text indicates the following from the above.

<Manufacturing method of gas barrier laminate>
1 and 2 are cross-sectional views schematically showing an example of the structure of the gas barrier laminated body 100 according to the embodiment of the present invention.
The gas barrier laminate 100 is provided on at least one surface of the base material layer 101 and the base material layer 101, and heats a mixture containing a polycarboxylic acid and a polyamine compound (hereinafter, also referred to as a coating material for a gas barrier). The gas barrier polymer layer 103 formed by the above-mentioned method is provided.

Hereinafter, an example of a method for manufacturing the gas barrier laminate 100 according to the present embodiment will be described.
The method for producing the gas barrier laminate 100 according to the present embodiment includes (1) a step of applying a mixture containing a polycarboxylic acid and a polyamine compound to the base material layer 101 to obtain a coated layer, and (2) a heating means. The step of forming the gas barrier polymer layer 103 having an amide bond by heating the coating layer with a dehydration condensation reaction between the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound. And, including. Then, in the step (2), the heating means includes at least one selected from the conduction heat transfer method and the radiant heat transfer method.

First, (1) a step of applying a mixture containing a polycarboxylic acid and a polyamine compound to the base material layer 101 to obtain a coated layer will be described.

First, a coating material for a gas barrier is prepared.
The coating material for a gas barrier can be prepared, for example, as follows.

First, the carboxyl group of the polycarboxylic acid is completely or partially neutralized by adding a base to the polycarboxylic acid. The polyamine compound is then added to the polycarboxylic acid with the carboxyl groups completely or partially neutralized. By mixing the polycarboxylic acid and the polyamine compound in such a procedure, the formation of aggregates of the polycarboxylic acid and the polyamine compound can be suppressed, and a uniform gas barrier coating material can be obtained. This makes it possible to more effectively proceed with the dehydration condensation reaction between the -COO- group contained in the polycarboxylic acid and the amino group contained in the polyamine compound.

By neutralizing the polycarboxylic acid with the base according to the present embodiment, it is possible to suppress the occurrence of gelation when the polyamine compound and the polycarboxylic acid are mixed. Therefore, in the polycarboxylic acid, it is preferable to use a base to make a partially neutralized product or a completely neutralized product of a carboxyl group from the viewpoint of preventing gelation. The neutralized product can be obtained by partially or completely neutralizing the carboxyl group of the polycarboxylic acid with a base (that is, making the carboxyl group of the polycarboxylic acid partially or completely carboxylate). .. This makes it possible to prevent gelation when the polyamine compound is added.
The partially neutralized product is prepared by adding a base to an aqueous solution of the polycarboxylic acid, and the desired degree of neutralization can be obtained by adjusting the amount ratio of the polycarboxylic acid to the base. In the present embodiment, the degree of neutralization of the polycarboxylic acid by the base is preferably 30 to 100 equivalent%, preferably 40 to 100, from the viewpoint of sufficiently suppressing gelation caused by the neutralization reaction of the polyamine compound with the amino group. Equivalent%, more preferably 50-100 equivalent%.

As the base, any water-soluble base can be used. As the water-soluble base, either or both of a volatile base and a non-volatile base can be used, but the volatility is easy to remove during drying and curing from the viewpoint of suppressing the deterioration of the gas barrier property due to the remaining free base. It is preferably a base.
Examples of the volatile base include tertiary amines such as ammonia, morpholine, alkylamine, 2-dimethylaminoethanol, N-methylmonophorin, ethylenediamine, and triethylamine, aqueous solutions thereof, or mixtures thereof. An aqueous ammonia solution is preferable from the viewpoint of obtaining good gas barrier properties.
Examples of the non-volatile base include sodium hydroxide, lithium hydroxide, potassium hydroxide, an aqueous solution thereof, or a mixture thereof.

Further, the solid content concentration of the gas barrier coating material is preferably set to 0.5 to 15% by mass, more preferably 1 to 10% by mass, from the viewpoint of improving the coatability.

(Mixing ratio of polycarboxylic acid and polyamine compound)
In the present embodiment, (the number of moles of -COO- groups contained in the polycarboxylic acid in the coating material for gas barrier) / (the number of moles of amino groups contained in the polyamine compound in the coating material for gas barrier) is preferably 100. It is more than / 22, more preferably 100/25 or more, and particularly preferably 100/29 or more.
On the other hand, in the present embodiment, (the number of moles of -COO- groups contained in the polycarboxylic acid in the coating material for gas barrier) / (the number of moles of amino groups contained in the polyamine compound in the coating material for gas barrier) is preferable. Is 100/99 or less, more preferably 100/86 or less, and particularly preferably 100/75 or less. In order to obtain the gas barrier polymer layer 103 according to the present embodiment, (the number of moles of -COO- group contained in the polycarboxylic acid in the gas barrier coating material) / (contained in the polyamine compound in the gas barrier coating material). It is preferable to adjust the blending ratio of the polycarboxylic acid and the polyamine compound in the coating material for the gas barrier so that the number of moles of the amino group) is within the above range.

(Polycarboxylic acid)
The polycarboxylic acid according to this embodiment has two or more carboxyl groups in the molecule. Specifically, homopolymers of α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, cinnamic acid, 3-hexenoic acid, and 3-hexendioic acid, or homopolymers thereof. Examples include copolymers. Further, it may be a copolymer of the above α, β-unsaturated carboxylic acid with esters such as ethyl esters and olefins such as ethylene.
Among these, homopolymers of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, crotonic acid, and cinnamic acid or copolymers thereof are preferable, and polyacrylic acid, polymethacrylic acid, and acrylic acid and methacrylic acid are co-polymerized. It is more preferably one or more polymers selected from the polymers, further preferably at least one polymer selected from polyacrylic acid and polymethacrylic acid, and a homopolymer of acrylic acid. , At least one polymer selected from methacrylic acid homopolymers is particularly preferred.
Here, in the present embodiment, the polyacrylic acid includes both a homopolymer of acrylic acid and a copolymer of acrylic acid and other monomers. In the case of a copolymer of acrylic acid and another monomer, polyacrylic acid contains a constituent unit derived from acrylic acid in 100% by mass of the polymer, usually 90% by mass or more, preferably 95% by mass or more. It preferably contains 99% by mass or more.
Further, in the present embodiment, the polymethacrylic acid includes both a homopolymer of methacrylic acid and a copolymer of methacrylic acid and another monomer. In the case of a copolymer of methacrylic acid and another monomer, polymethacrylic acid contains a constituent unit derived from methacrylic acid in 100% by mass of the polymer, usually 90% by mass or more, preferably 95% by mass or more. It preferably contains 99% by mass or more.

The polycarboxylic acid according to the present embodiment is a polymer obtained by polymerizing a carboxylic acid monomer, and the molecular weight of the polycarboxylic acid is preferably 500 to 2,000,000 from the viewpoint of excellent balance between gas barrier property and handleability. , 500 to 1,000,000 is more preferable. Further, 5,000 to 500,000 is preferable, and 10,000 to 100,000 is particularly preferable.
Here, in the present embodiment, the molecular weight of the polycarboxylic acid is a weight average molecular weight in terms of polyethylene oxide, and can be measured by gel permeation chromatography (GPC).

(Polyamine compound)
The polyamine compound according to this embodiment is a polymer having two or more amino groups at the main chain, side chain, or terminal. Specific examples thereof include aliphatic polyamines such as polyallylamine, polyvinylamine, polyethyleneimine and poly (trymethyleneimine); polyamides having an amino group in the side chain such as polylysine and polyarginine; and the like. Further, a polyamine in which a part of the amino group is modified may be used. Polyethyleneimine is more preferable from the viewpoint of obtaining good gas barrier properties.

The weight average molecular weight of the polyamine compound according to the present embodiment is preferably 50 to 5,000,000, more preferably 100 to 2,000,000, and 1,500 to 1,500, from the viewpoint of excellent balance between gas barrier properties and handleability. 1,000,000 is even more preferred, 1,500 to 500,000 is even more preferred, and 1,500 to 100,000 is particularly preferred.
Here, in the present embodiment, the molecular weight of the polyamine compound can be measured by using a boiling point elevation method or a viscosity method.

Further, it is preferable to further add a surfactant to the coating material for the gas barrier from the viewpoint of preventing the generation of repelling during coating. The amount of the surfactant added is preferably 0.01 to 3% by mass, more preferably 0.01 to 1% by mass, when the total solid content of the gas barrier coating material is 100% by mass.

Examples of the surfactant according to the present embodiment include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants and the like, from the viewpoint of obtaining good coatability. Therefore, nonionic surfactants are preferable, and polyoxyethylene alkyl ethers are more preferable.

Examples of the nonionic surfactant include polyoxyalkylene alkylaryl ethers, polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, sorbitan fatty acid esters, silicone-based surfactants, and acetylene alcohol-based surfactants. , Fluorine-containing surfactant and the like.

Examples of the polyoxyalkylene alkyl aryl ethers include polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene dodecylphenyl ether.
Examples of the polyoxyalkylene alkyl ethers include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene lauryl ether.
Examples of the polyoxyalkylene fatty acid ester include polyoxyethylene oleic acid ester, polyoxyethylene lauric acid ester, and polyoxyethylene distearate.
Examples of the sorbitan fatty acid esters include sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquiorate, polyoxyethylene monooleate, and polyoxyethylene stearate.
Examples of the silicone-based surfactant include dimethylpolysiloxane and the like.
Examples of the acetylene alcohol-based surfactant include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3, 5-Diol-1-hexyne-3ol and the like can be mentioned.
Examples of the fluorine-containing surfactant include fluorine alkyl esters and the like.

The coating material for a gas barrier according to the present embodiment may contain other additives as long as the object of the present invention is not impaired. For example, various additives such as lubricants, slip agents, anti-blocking agents, antistatic agents, antistatic agents, pigments, dyes, inorganic or organic fillers, and polyvalent metal compounds may be added.

Next, a coating material for a gas barrier is applied to the base material layer 101 to obtain a coating layer.

The method for applying the gas barrier coating material according to the present embodiment to the base material layer 101 is not particularly limited, and a normal method can be used. For example, Mayer bar coater, air knife coater, direct gravure coater, gravure offset, arc gravure coater, gravure coater such as gravure reverse and jet nozzle method, top feed reverse coater, bottom feed reverse coater and reverse roll such as nozzle feed reverse coater. Examples thereof include a method of coating using various known coating machines such as a coater, a 5-roll coater, a lip coater, a bar coater, a bar reverse coater, a die coater, and an applicator.

The thickness (wet thickness) of the coating layer is preferably 0.05 to 300 μm, more preferably 1 to 200 μm, further preferably 1 to 100 μm, and particularly preferably 0.05 to 30 μm.
When the thickness of the coating layer is not more than the above upper limit value, curling of the obtained gas barrier laminate 100 can be suppressed. Further, when the thickness of the coating layer is not more than the above upper limit value, the dehydration condensation reaction between the -COO- group contained in the polycarboxylic acid and the amino group contained in the polyamine compound can be more effectively promoted. ..
Further, when the thickness of the coating layer is at least the above lower limit value, the barrier performance of the obtained gas barrier laminate 100 can be improved.
The thickness of the gas barrier polymer layer 103 after the heat treatment is preferably 0.01 to 15 μm, more preferably 0.05 to 5 μm, further preferably 0.1 to 1 μm, and having gas barrier properties and stability with the substrate layer 101. It is particularly preferably 0.15 to 0.45 μm or less because it is excellent in the balance of adhesion.

Subsequently, (2) the coating layer is heated by a heating means, and the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound are subjected to a dehydration condensation reaction to have a gas barrier property having an amide bond. The step of forming the polymer layer 103 will be described.

In the method for producing the gas barrier laminate 100 of the present embodiment, in order to obtain the gas barrier polymer layer 103 according to the present embodiment, as a means for heating the coating layer, "conduction transfer" by contact with a high temperature body is performed. At least one selected from "heat method" and "radiant heat transfer method" by heat radiation from a high temperature body is adopted.
Thereby, the dehydration condensation reaction between the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound can be efficiently promoted.

The conduction heat transfer method is a method of heating a material in contact with a high temperature body by heat conduction, and examples of the device for heating by the conduction heat transfer method include a heating roll and the like. In the case of heating with a heating roll, heating is performed by bringing the heating roll into contact with the material. The heating roll is preferable from the viewpoint of excellent heat conduction efficiency to the film.
The radiant heat transfer method is a method in which the radiant energy of infrared rays emitted by a high-temperature body is used as a heat source, and the infrared rays absorbed by the material are converted into heat in the material to heat the material. As the infrared source, an infrared heater, an infrared lamp, or the like is used.

In the step of forming the gas barrier polymer layer 103, the heat treatment temperature is 160 to 250 ° C., the heat treatment time is 1 second to 10 minutes, preferably the heat treatment temperature is 180 to 240 ° C., and the heat treatment time is 5 seconds to 5 seconds. It is desirable to perform the heat treatment under the conditions that the heat treatment temperature is 190 ° C. to 230 ° C. and the heat treatment time is 10 seconds to 2 minutes.

When the coating layer is heated, it may be heated from the base material layer 101 side or from the coating layer side, but the gas barrier polymer layer 103 having excellent gas barrier performance may be heated more stably. From the viewpoint of obtaining, it is preferable to heat from the substrate layer 101 side.

Further, when heating the coating layer, a heating means by a convection heat transfer method may be appropriately combined. Here, heating by the convection heat transfer method is a heating method in which heated air is used as hot air and is brought into direct contact with the material, and heat transfer is caused by the relative speed between the material and the hot air and the temperature difference between the material and the hot air. It is controlled by the amount of heat.
Examples of the device for heating by the convection heat transfer method include a hot air dryer, a hot air oven, and a dryer.

From the viewpoint of effectively advancing the dehydration condensation reaction between the -COO- group contained in the polycarboxylic acid and the amino group contained in the polyamine compound, the heat treatment temperature and the heat treatment time depend on the wet thickness of the coating material for the gas barrier. It is important to adjust.

In the step of forming the gas barrier polymer layer 103, the coating layer may be dried before the heating of the coating layer. The above drying and heat treatment may be performed at the same time.
In the step of forming the gas barrier polymer layer 103, when drying is performed before the heat treatment of the coating layer, the drying may be performed under the conditions of a drying temperature of 60 to 150 ° C. and a drying time of 1 second to 60 seconds. desirable.

The gas barrier polymer layer 103 according to the present embodiment is formed by the above-mentioned coating material for gas barrier, and the coating material for gas barrier is applied to the base material layer 101 and the inorganic material layer 102 described later, and then dried. It is obtained by performing heat treatment and curing the coating material for gas barrier.

Further, in the step of forming the gas barrier polymer layer 103, in the infrared absorption spectrum of the obtained gas barrier polymer layer 103, the total peak area in the range of the absorption band 1493 cm ^-1 or more and 1780 cm ^-1 or less is set as A, and the absorption band is set. When the total peak area in the range of 1598 cm -1 or more and 1690 cm ^-1 or less is B, the area ratio of the amide bond represented by B / A is preferably ^0.330 or more, more preferably 0.370 from the viewpoint of gas barrier property. Above, heating is carried out until it becomes more preferably 0.400 or more, and particularly preferably 0.420 or more. As a result, the gas barrier laminated body 100 having further excellent gas barrier performance can be obtained. Further, the upper limit of the area ratio of the amide bond represented by B / A is preferably 0.700 or less, more preferably 0.680 or less, particularly from the viewpoint of further improving the balance between appearance, dimensional stability and productivity. It is preferably 0.650 or less.

In the gas barrier polymer layer 103 according to the present embodiment, absorption of the unreacted carboxylic acid based on νC = O is observed in the vicinity of 1700 cm ^-1 in the infrared absorption spectrum, and absorption based on νC = O of the amide bond having a crosslinked structure is observed. Is found around 1630 to 1685 cm ^-1 , and absorption of the carboxylate based on νC = O is seen around 1540 to 1560 cm ^-1 .
That is, in the present embodiment, the total peak area A in the range of the absorption band 1493 cm ^-1 or more and 1780 cm ^-1 or less in the infrared absorption spectrum represents an index of the total amount of the carboxylic acid, the amide bond and the carboxylate, and the absorption band 1598 cm. The total peak area B in the range of ^-1 or more and 1690 cm ^-1 or less represents an index of the abundance of amide bonds, and the total peak area C in the range of absorption zone 1690 cm ^-1 or more and 1780 cm ^-1 or less, which will be described later, is an unreacted carboxylic acid. The total peak area D in the range of absorption zone 1493 cm ^-1 or more and 1598 cm ^-1 or less, which will be described later, represents an index of the abundance of carboxylic acid salts, that is, ionic cross-links of carboxyl groups and amino groups. it is conceivable that.

In this embodiment, the total peak areas A to D can be measured by the following procedure.
First, a 1 cm × 3 cm measurement sample is cut out from the gas barrier polymer layer 103 of the present embodiment. Next, the infrared absorption spectrum of the surface of the gas barrier polymer layer 103 is obtained by infrared total reflection measurement (ATR method). From the obtained infrared absorption spectrum, the total peak areas A to D are calculated by the following procedures (1) to (4).
(1) The absorbances of 1780 cm ^-1 and 1493 cm ^-1 are connected by a straight line (N), and the absorption spectrum in the absorption band 1493 cm ^-1 or more and 1780 cm ^-1 or less and the area surrounded by N are defined as the total peak area A.
(2) Draw a straight line (O) vertically from the absorbance (Q) of 1690 cm ^-1 , let P be the intersection of N and O, and draw a straight line (S) vertically from the absorbance (R) of 1598 cm ^-1 . Let T be the intersection of S, and the absorption spectrum in the range of absorption zone 1598 cm ^-1 or more and 1690 cm ^-1 or less, and the area surrounded by straight lines S, point T, straight line N, point P, straight line O, absorbance Q, and absorbance R are all peaks. The area is B.
(3) Absorption band The area surrounded by the absorption spectrum in the range of 1690 cm ^-1 or more and 1780 cm ^-1 or less and the absorbance Q, the straight line O, the point P, and the straight line N is defined as the total peak area C.
(4) Absorption band The area surrounded by the absorption spectrum in the range of 1493 cm ^-1 or more and 1598 cm ^-1 or less and the absorbance R, the straight line S, the point T, and the straight line N is defined as the total peak area D.
Next, the area ratios B / A, C / A, and D / A are obtained from the area obtained by the above method.
For the measurement of the infrared absorption spectrum of the present embodiment (infrared total reflection measurement: ATR method), for example, an IRT-5200 apparatus manufactured by Nippon Spectroscopy Co., Ltd. is used, and a PKM-GE-S (Germanium) crystal is attached to the incident angle. It can be performed under the conditions of 45 degrees, room temperature, resolution of 4 cm ^-1 , and the number of integrations of 100 times.

The gas barrier polymer layer 103 formed by a mixture containing a polycarboxylic acid and a polyamine compound has two types of crosslinked structures, an ion crosslink and an amide crosslink, and the abundance ratio of these crosslinked structures improves the gas barrier performance. Is important in. The ion cross-linking is generated by causing an acid-base reaction between the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound, and the amide cross-linking is contained in the polycarboxylic acid. It is produced by causing a dehydration condensation reaction between the carboxyl group and the amino group contained in the polyamine compound.
Therefore, in order to improve the performance balance of appearance, dimensional stability, and productivity while improving the gas barrier performance such as oxygen barrier property and water vapor barrier property under both conditions under high humidity and after boiling and retort treatment. As a design guideline, the scale of the area ratio of the amide bond shown in the above B / A can be applied. By controlling the production conditions, the area ratio of the amide bond represented by the above B / A of the gas barrier polymer layer 103 can be adjusted to a specific value or more, and the gas barrier polymer layer having such characteristics can be adjusted. 103 more effectively develops gas barrier properties under both high humidity conditions and after boiling and retort treatment, and is also excellent in balance between appearance, dimensional stability, and productivity.
That is, by setting the area ratio of the amide bond represented by B / A to the above lower limit value or more, the oxygen barrier property and the water vapor barrier property are further excellent under both conditions under high humidity and after the boil / retort treatment. However, it is possible to obtain the gas barrier laminated body 100 having an excellent balance between appearance, dimensional stability, and productivity.

The reason why such a gas barrier polymer layer 103 is excellent in the above performance balance is not necessarily clear, but the gas barrier polymer layer in which the area ratio of the amide bond represented by B / A is within the above range is described above. It is considered that this is because the two types of cross-linking structures, ionic cross-linking and amide cross-linking, form a well-balanced and dense structure.
That is, it is considered that the fact that the area ratio of the amide bond represented by the above B / A is within the above range means that two types of cross-linking structures, ionic cross-linking and amide cross-linking, are formed in a well-balanced manner. ..

Further, in the step of forming the gas barrier polymer layer 103, when the total peak area in the absorption band 1690 cm ^-1 or more and 1780 cm ^-1 or less in the infrared absorption spectrum of the obtained gas barrier polymer layer 103 is C. From the viewpoint of further improving the balance between appearance, dimensional stability and productivity, the area ratio of the carboxylic acid represented by C / A is preferably 0.040 or more, more preferably 0.060 or more, and particularly preferably 0. Heat until it reaches 080 or more.
Further, the upper limit of the area ratio of the carboxylic acid indicated by the above C / A is from the viewpoint of further improving the oxygen barrier property and the water vapor barrier property under both conditions under high humidity and after the boil / retort treatment. It is preferably 0.500 or less, more preferably 0.450 or less, and particularly preferably 0.400 or less.

Further, in the step of forming the gas barrier polymer layer 103, when the total peak area in the absorption band 1493 cm ^-1 or more and 1598 cm ^-1 or less in the infrared absorption spectrum of the obtained gas barrier polymer layer 103 is D. The area ratio of the carboxylate represented by D / A is preferably 0. From the viewpoint of further improving the oxygen barrier property and the water vapor barrier property under both conditions of high humidity and after boiling / retort treatment. Heating is performed until it reaches 100 or more, more preferably 0.150 or more.
Further, the upper limit of the area ratio of the carboxylate represented by the above D / A is preferably 0.450 or less, more preferably 0.420 or less from the viewpoint of further improving the balance between appearance, dimensional stability and productivity. , Particularly preferably 0.400 or less.

The area ratio of the amide bond represented by B / A, the area ratio of the carboxylic acid represented by C / A, and the area ratio of the carboxylic acid salt represented by D / A of the gas barrier polymer layer 103 according to the present embodiment are: It can be controlled by appropriately adjusting the production conditions of the gas barrier polymer layer 103. In the present embodiment, in particular, the compounding ratio of the polycarboxylic acid and the polyamine compound, the method for preparing the gas barrier coating material, the method, temperature, time, etc. of the heat treatment of the gas barrier coating material are the amides represented by the above B / A. It is mentioned as a factor for controlling the area ratio of a bond, the area ratio of a carboxylic acid represented by the above C / A, and the area ratio of the carboxylic acid salt represented by the above D / A.

(Base layer)
The base material layer 101 of the present embodiment is formed of, for example, a thermosetting resin, a thermoplastic resin, or an organic material such as paper, and contains at least one selected from a thermosetting resin and a thermoplastic resin. Is preferable.

Examples of the thermosetting resin include known thermosetting resins such as epoxy resin, unsaturated polyester resin, phenol resin, urea-melamine resin, polyurethane resin, silicone resin, and polyimide.

Examples of the thermoplastic resin include known thermoplastic resins such as polyolefins (polyethylene, polypropylene, poly (4-methyl-1-pentene), poly (1-butene), etc.) and polyesters (polyethylene terephthalate, polybutylene terephthalate, polyethylene). Naphthalate, etc.), Polyamide (nylon-6, nylon-66, polymethoxylen adipamide, etc.), polyvinyl chloride, polyimide, ethylene vinyl acetate copolymer or its saponified product, polyvinyl alcohol, polyacrylonitrile, polycarbonate, polystyrene, etc. , Ionomer, fluororesin or a mixture thereof and the like.
Among these, from the viewpoint of improving transparency, one or more selected from polypropylene, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyamide, and polyimide is preferable, and polyethylene terephthalate and polyethylene naphthalate are selected. One or more of them are more preferable.
Further, the base material layer 101 formed of the thermoplastic resin may be a single layer or two or more types of layers depending on the use of the gas barrier laminate 100.

Further, the film formed of the thermosetting resin and the thermoplastic resin may be stretched in at least one direction, preferably biaxially, to form a base material layer.

The base material layer 101 of the present embodiment has one or more heats selected from polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyamide, and polyimide from the viewpoint of excellent transparency, rigidity, and heat resistance. A biaxially stretched film formed of a plastic resin is preferable, and a biaxially stretched film formed of one or more kinds of thermoplastic resins selected from polyethylene terephthalate and polyethylene naphthalate is more preferable.

Further, the surface of the base material layer 101 may be coated with polyvinylidene chloride, polyvinyl alcohol, an ethylene / vinyl alcohol copolymer, an acrylic resin, a urethane resin, or the like.
Further, the base material layer 101 may be surface-treated in order to improve the adhesiveness with the gas barrier polymer layer 103. Specifically, surface activation treatments such as corona treatment, flame treatment, plasma treatment, undercoat treatment, and primer coating treatment may be performed.

The thickness of the base material layer 101 is preferably 1 to 1000 μm, more preferably 1 to 500 μm, and even more preferably 1 to 300 μm from the viewpoint of obtaining good film characteristics.

The shape of the base material layer 101 is not particularly limited, and examples thereof include a sheet or film shape, a tray, a cup, and a hollow body.

(Inorganic layer)
As shown in FIG. 2, in the gas barrier laminate 100, the inorganic layer 102 may be further laminated between the substrate layer 101 and the gas barrier polymer layer 103. Thereby, the barrier performance such as oxygen barrier property and water vapor barrier property can be further improved.

Examples of the inorganic substance constituting the inorganic substance layer 102 of the present embodiment include metals, metal oxides, metal nitrides, metal fluorides, metal oxynitrides and the like capable of forming a thin film having a barrier property.
Examples of the inorganic substances constituting the inorganic substance layer 102 include periodic table group 2A elements such as beryllium, magnesium, calcium, strontium, and barium; periodic table transition elements such as titanium, zirconium, ruthenium, hafnium, and tantalum; periodic table of zinc and the like. Group 2B elements; Periodic table of group 3A elements such as aluminum, gallium, indium, and tarium; Periodic table of group 4A elements such as silicon, germanium, and tin; Periodic table of group 6A elements such as selenium, tellurium, etc. One or more selected from a substance, a fluoride, an oxynitride and the like can be mentioned.
In this embodiment, the family name of the periodic table is shown by the old CAS formula.

Further, among the above-mentioned inorganic substances, one or more kinds of inorganic substances selected from the group consisting of silicon oxide, aluminum oxide, and aluminum are preferable because they have an excellent balance of barrier properties, cost, and the like.
In addition to silicon dioxide, silicon monoxide and silicon suboxide may be contained in the silicon oxide.

The inorganic substance layer 102 is composed of the above-mentioned inorganic substances. The inorganic layer 102 may be composed of a single inorganic layer or may be composed of a plurality of inorganic layers. When the inorganic layer 102 is composed of a plurality of inorganic layers, it may be composed of the same type of inorganic layer or may be composed of different types of inorganic layers.

The thickness of the inorganic layer 102 is usually 1 nm or more and 1000 nm or less, preferably 1 nm or more and 500 nm or less, from the viewpoint of the balance of barrier property, adhesion, handleability and the like.
In the present embodiment, the thickness of the inorganic layer 102 can be determined from an observation image by a transmission electron microscope or a scanning electron microscope.

The method for forming the inorganic layer 102 is not particularly limited, and for example, a vacuum vapor deposition method, an ion plating method, a sputtering method, a chemical vapor deposition method, a physical vapor deposition method, a chemical vapor deposition method (CVD method), and plasma CVD method. The inorganic layer 102 can be formed on one side or both sides of the base material layer 101 by a method, a solgel method, or the like. Above all, film formation under reduced pressure such as a sputtering method, an ion plating method, a chemical vapor deposition method (CVD), a physical vapor deposition method (PVD), and a plasma CVD method is desirable. As a result, chemically active molecular species containing silicon such as silicon nitride and silicon oxide react rapidly, thereby improving the smoothness of the surface of the inorganic layer 102 and reducing the number of pores. It is expected to be.
In order to carry out these bonding reactions rapidly, it is desirable that the inorganic atom or compound is a chemically active molecular species or atomic species.

The gas barrier laminate 100 of the present embodiment has excellent gas barrier performance, and includes various packaging materials such as food packaging materials for contents that require high gas barrier properties, medical applications, industrial applications, and daily miscellaneous goods applications. It can also be suitably used as a packaging material.
Further, the gas barrier laminate 100 of the present embodiment is suitable as, for example, a vacuum heat insulating film that requires high barrier performance; a sealing film for sealing an electroluminescence element, a solar cell, or the like; Can be used for.

Although the embodiments of the present invention have been described above with reference to the drawings, these are examples of the present invention, and various configurations other than the above can be adopted.

Hereinafter, this embodiment will be described in detail with reference to Examples and Comparative Examples. The present embodiment is not limited to the description of these examples.

<Preparation of solution (Z)>
Aqueous aqueous solution of ammonium polyacrylic acid prepared by adding purified water to a mixture of ammonium polyacrylic acid (manufactured by Toa Synthetic Co., Ltd., product name: Aron A-30, 30% by mass aqueous solution, molecular weight: 100,000) to make a 10% by mass solution. Got
<Preparation of solution (Y)>
Purified water was added to polyethyleneimine (manufactured by Wako Pure Chemical Industries, Ltd., product name: polyethyleneimine, average molecular weight: about 10,000) to obtain a 10% by mass aqueous solution of polyethyleneimine.

[Example 1-1]
A mixed solution was prepared by mixing and stirring 79 g of the aqueous ammonium polyacrylate solution (Z) and 21 g of the aqueous polyethyleneimine solution (Y).
Further, purified water was added so that the solid content concentration of the above mixed solution was 2.5% by mass, and after stirring until a uniform solution was obtained, a nonionic surfactant (polyoxyethylene lauryl ether, manufactured by Kao Co., Ltd.) was added. , Trade name: Emargen 120) was mixed so as to be 0.3% by mass with respect to the solid content of the mixed solution, and a solution (V) was prepared.
The obtained solution (V) was applied to the corona-treated surface of a biaxially stretched polyethylene terephthalate film (PET12 manufactured by Unitika Ltd.) having a thickness of 12 μm after heat treatment with a mayer bar (that is, the thickness of the gas barrier polymer layer). ) Is 0.3 μm, dried using a hot air dryer under the conditions of temperature; 100 ° C., time; 30 seconds, and further on a hot roll, temperature; 200 ° C., time; conditions of 60 seconds. A gas barrier laminated film was obtained by heat treatment with.

[Example 1-2]
A gas barrier laminated film was obtained in the same manner as in Example 1-1 except that the heat roll was a dryer using both a far-infrared heater and hot air.

[Comparative Example 1]
A gas barrier laminated film was obtained in the same manner as in Example 1-1 except that the hot roll was used as a hot air dryer.

[Example 2-1]
A gas barrier laminated film was obtained in the same manner as in Example 1-1 except that the heat treatment was carried out under the conditions of temperature; 210 ° C. and time; 60 seconds.

[Example 2-2]
A gas barrier laminated film was obtained in the same manner as in Example 2-1 except that the heat roll was a dryer using both a far-infrared heater and hot air.

[Comparative Example 2]
A gas barrier laminated film was obtained in the same manner as in Example 2-1 except that the hot roll was used as a hot air dryer.

[Example 3]
A gas barrier laminated film was obtained in the same manner as in Example 1-1 except that the heat treatment was carried out under the conditions of temperature; 220 ° C. and time; 45 seconds.

[Comparative Example 3]
A gas barrier laminated film was obtained in the same manner as in Example 3 except that the hot roll was used as a hot air dryer.

The gas barrier laminated films obtained in Examples and Comparative Examples were evaluated as follows. The results obtained are shown in Table 1.

<Manufacturing of multilayer film for physical property evaluation>
(1) Ester-based adhesive (polyurethane-based adhesive (Mitsui Chemicals, Inc. product name: Takelac A525S): 9 on one side of a 70 μm-thick unstretched polypropylene film (Mitsui Chemicals Tocello Co., Ltd. product name: RXC-22) A parts by mass, an isocyanate-based curing agent (trade name: Takenate A50 manufactured by Mitsui Chemicals, Inc.): 1 part by mass and ethyl acetate: 7.5 parts by mass) were applied. After drying, the gas barrier laminated film obtained in Examples and Comparative Examples was laminated with the gas barrier polymer layer surface (dry laminate) to obtain a multilayer film.

(2) Retort treatment The multilayer film obtained in (1) above is folded back so that the unstretched polypropylene film is on the inner surface, heat-sealed on both sides to form a bag, and then 70 cc of water is added as the content. One side was heat-sealed to make a bag, which was retorted with a high-temperature and high-pressure retort sterilizer at 130 ° C. for 30 minutes. After the retort treatment, the contents were drained to obtain a multilayer film after the retort treatment.

(3) Oxygen permeability [ml / ( ^m2 , day, MPa)]
The multilayer film obtained by the above method was measured using OX-TRAN2 / 21 manufactured by Mocon Co., Ltd. under the conditions of temperature 20 ° C. and humidity 90% RH according to JIS K 7126.

(4) IR area ratio For infrared absorption spectrum measurement (infrared total reflection measurement: ATR method), an IRT-5200 device manufactured by Nippon Spectroscopy Co., Ltd. was used, and a PKM-GE-S (Germanium) crystal was attached to the incident angle of 45 degrees. The measurement was performed under the conditions of room temperature, resolution of 4 cm ^-1 , and the number of integrations of 100 times. The obtained absorption spectrum was analyzed by the method described above, and the total peak areas A to D were calculated. Then, the area ratios B / A, C / A, and D / A were obtained from the total peak areas A to D.

Comparing Examples 1-1 and 1-2 and Comparative Example 1 in which the heat treatment time and temperature are the same, the heat roll and farther than in Comparative Example 1 using only the hot air dryer as the heating means of the coating layer. Examples 1-1 and 1-2 using infrared heating had a higher proportion of amide bonds (B / A). That is, it was found that Examples 1-1 and 1-2 were able to more efficiently produce the gas barrier polymer layer 103 having an amide crosslinked structure than Comparative Example 1. Further, it was found that such a gas barrier laminated film has low oxygen permeability and is superior in gas barrier performance.
Further, from the comparative examples with Examples 2-1 and 2-2 and Comparative Example 2 having the same heat treatment time and temperature, and the comparative examples with Example 3 and Comparative Example 3, the heating means for the coating layer is also obtained. It was found that the proportion of amide bonds (B / A) was higher in the examples using hot rolls and far-infrared heating than in the comparative examples using only the hot air dryer.
From the above, it was found that according to the production method of the present invention, a gas barrier laminate having excellent gas barrier performance can be efficiently produced.

This application claims priority based on Japanese application Japanese Patent Application No. 2015-103500 filed on May 21, 2015, and all of its disclosures are incorporated herein by reference.

Claims (7)

A method for producing a gas barrier laminate comprising a substrate layer and a gas barrier polymer layer provided on at least one surface of the substrate layer.
A process of applying a gas barrier coating material containing a polycarboxylic acid and a polyamine compound to a base material layer to obtain a coating layer, and
A drying step of drying the coating layer and removing the solvent contained in the gas barrier coating material.
The dried coating layer is heated by a heating means , and the carboxyl group contained in the polycarboxylic acid and the amino group contained in the polyamine compound are subjected to a dehydration condensation reaction to form a gas barrier polymer layer having an amide bond. The heat treatment process to form and
Including
The heating means includes at least one selected from a conduction heat transfer method and a radiant heat transfer method.
A method for producing a gas barrier laminate, wherein the heating means comprises at least one selected from conduction heat transfer by a heating roll and radiant heat transfer by infrared rays . The drying temperature in the drying step is 60 ° C. or higher and 150 ° C. or lower.
The method for producing a gas barrier laminate according to claim 1, wherein the heat treatment temperature in the heat treatment step is 160 ° C. or higher and 250 ° C. or lower. The method for producing a gas barrier laminate according to claim 1 or 2, wherein the heating means further includes a convection heat transfer method. In the heat treatment step of forming the gas barrier polymer layer,
In the infrared absorption spectrum of the obtained gas barrier polymer layer,
The total peak area in the range of absorption band 1493 cm ^-1 or more and 1780 cm ^-1 or less is defined as A.
When the total peak area in the range of absorption band 1598 cm ^-1 or more and 1690 cm ^-1 or less is B.
The method for producing a gas barrier laminate according to any one of claims 1 to 3, wherein heating is performed until the area ratio of the amide bond represented by B / A becomes 0.330 or more. (Number of moles of -COO- group contained in the polycarboxylic acid in the mixture) / (Number of moles of amino group contained in the polyamine compound in the mixture) = more than 100/22 and 100/99 or less. The method for producing a gas barrier laminate according to any one of claims 1 to 4. The invention according to any one of claims 1 to 5, wherein the polycarboxylic acid comprises one or more polymers selected from polyacrylic acid, polymethacrylic acid, and a copolymer of acrylic acid and methacrylic acid. Method for manufacturing a gas barrier laminate. The method for producing a gas barrier laminate according to any one of claims 1 to 6, wherein the polyamine compound contains polyethyleneimine.

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