JP5456241B2 - Gas barrier material forming composition, gas barrier material, method for producing the same, and gas barrier packaging material - Google Patents

Description

  The present invention relates to a composition for forming a gas barrier material using a cross-linking agent comprising a compound having a specific functional group in a polycarboxylic acid-based polymer. Further, the present invention relates to a gas barrier material forming composition having gas barrier properties, retort resistance and flexibility, a gas barrier material, a production method thereof, and a packaging material using such a gas barrier material.

Conventionally, various types of gas barrier resins have been used, and in particular, polyvinylidene chloride, polyacrylonitrile, ethylene vinyl alcohol copolymer and the like are known as gas barrier resins. However, polyvinylidene chloride and polyacrylonitrile have a tendency to refrain from their use due to environmental problems. In ethylene vinyl alcohol copolymers, the gas barrier property is highly dependent on humidity, and the gas barrier property decreases under high humidity conditions. There was a problem.
As a method for imparting a gas barrier property to a packaging material, a film in which an inorganic substance is vapor-deposited on the surface of a substrate is also known. However, these films are very expensive, and the flexibility of the vapor-deposited film or the substrate or There is a problem of poor adhesion to other resin layers.

  In order to solve such a problem, a gas barrier film (Patent Document 1) in which a coating made of an aqueous polymer A, a water-soluble or water-dispersible polymer B, and an inorganic layered compound is formed on a substrate, Gas barrier film (Patent Document 2) formed by coating a layer containing a metal compound on the surface of a molding layer comprising a mixture of poly (meth) acrylic acid polymer and polyalcohol, or polyvinyl alcohol and ethylene-malein Gas barrier paints (Patent Document 3) containing an acid copolymer and a divalent or higher metal compound have been proposed.

  In addition, by reacting a polycarboxylic acid polymer with a crosslinking agent having 2 to 4 functional groups that react with a carboxyl group and a metal ion having a valence of 2 or more, the polycarboxylic acid polymer is allowed to crosslink with a crosslinking agent. And a gas barrier resin composition having a weight ratio of 99.9 / 0.1 to 65/35 of the polycarboxylic acid polymer and the crosslinking agent formed by forming a cross-linked site by the above-described divalent or higher metal ions (patent) Document 4), or a film formed by forming a gas barrier coating layer on at least one surface of a thermoplastic resin film, the coating layer comprising a crosslinking agent containing an epoxy compound having three or more epoxy groups per molecule It is formed from cross-linked polyacrylic acid, and contains 1 to 100 parts by mass of the cross-linking agent with respect to 100 parts by mass of the polyacrylic acid. Gas barrier film (Patent Document 5) it has been proposed.

JP-A-9-151264 JP 2000-931 A Japanese Patent Laid-Open No. 2004-115776 JP 2003-171419 A JP 2002-240207 A

Even if the gas barrier material described in Patent Documents 1 to 5 is improved in gas barrier properties under high humidity conditions, it cannot withstand various requirements as a packaging material, and is still not sufficiently satisfactory. Absent.
That is, in the gas barrier film described in Patent Document 1, since the inorganic layered compound is only dispersed in the coating film, it is necessary to add a large amount of the inorganic layered compound in order to obtain excellent gas barrier properties. There is a problem that the mechanical strength is lowered, and the retort resistance is inferior. Further, the gas barrier film described in Patent Document 2 requires high-temperature and long-time heat treatment to form a coating film, and the gas barrier paint described in Patent Document 3 also requires a coating film in a short time. In the case of curing, it is necessary to perform a heat treatment at a high temperature. In the gas barrier materials described in Patent Documents 2 and 3, there is a problem in terms of productivity as well as a large influence of heat on the plastic substrate.

  In addition, the gas barrier resin composition described in Patent Document 4 requires a high temperature of 150 ° C. or higher or long-time heating to form a film. There are problems and the flexibility is not satisfactory. Further, the gas barrier film described in the cited document 5 also needs to be heated at a high temperature of 150 ° C. or higher, is inferior in flexibility, and is not sufficiently satisfactory in terms of retort resistance.

  In order to solve such a problem, the present inventors have formed an ether bond in carbon forming a double bond between the polycarboxylic acid polymer (A) and nitrogen, and oxygen in the ether bond. A compound (B) containing two ring structures (b) comprising a cross-linked structure formed by the reaction of the carboxyl group of the polycarboxylic acid polymer (A) with the ring structure (b). A gas barrier material characterized by the above has been proposed (Japanese Patent Application No. 2005-282008).

Such a gas barrier material does not cause the problems of the above prior art, has excellent gas barrier properties, retort resistance, flexibility, and can cure the coating film in a short time at a low temperature, thereby improving productivity. Is also excellent.
As a result of further earnest studies on the gas barrier material, the present inventors have used the compound (B) in combination with the compound (C) further having an epoxy group in the gas barrier material, so that it can be performed at a lower temperature and in a shorter time. It has been found that curing of can be performed.
Further, it will be clarified that the reaction for forming a crosslinked structure by the compound (B) is hindered by water present in the composition for forming a gas barrier material, and the gas barrier material can be removed if such water can be removed without affecting the crosslinking reaction. It has been found that the storage stability of the forming composition is improved, and in combination with the use of a compound having an epoxy group in combination, the coating film can be cured stably at a low temperature in a short time.

Accordingly, an object of the present invention is to form a gas barrier material having excellent gas barrier properties, retort resistance, and flexibility, and to enable curing at a lower temperature in a shorter time without affecting the plastic substrate. Another object is to provide a gas barrier material forming composition capable of improving productivity.
Another object of the present invention is to provide a method for producing the gas barrier material and a packaging material using the gas barrier material.

式中、ｎは、１〜１０の整数である。
本発明のガスバリア材形成用組成物においては、
１．ポリカルボン酸系ポリマー（Ａ）１００重量部当たり、前記化合物(Ｂ)を０．０１乃至６０重量部及び前記化合物（Ｃ）を０．０１乃至２０重量部の量で含有すること、
２．ポリカルボン酸系ポリマー（Ａ）が、ポリ（メタ）アクリル酸又はその部分中和物であること、
３．ポリカルボン酸系ポリマー（Ａ）１００重量部当たり、脱水剤（Ｄ）を１乃至１００重量部の量で含有すること、
４．脱水剤(Ｄ)が、オルト蟻酸メチル及び／又はオルト酢酸メチルであること、
が好適である。 According to the present invention, a ring structure (b) comprising an ether bond formed on the carbon that forms a double bond between the polycarboxylic acid polymer (A) and nitrogen, and oxygen in the ether bond. the Ri compound containing two (B) and the compound having at least two epoxy groups from (C) formed, wherein compound (B) is 2,2'-bis (2-oxazoline), the compound ( C) is the gas-barrier material forming composition according to claim der Rukoto those represented by the following formula (1) is provided.

In formula, n is an integer of 1-10.
In the gas barrier material forming composition of the present invention,
1. Containing 0.01 to 60 parts by weight of the compound (B) and 0.01 to 20 parts by weight of the compound (C) per 100 parts by weight of the polycarboxylic acid polymer (A);
2. Polycarboxylic acid polymer (A) is that it is a poly (meth) acrylic acid or partially neutralized product thereof,
3 . Containing the dehydrating agent (D) in an amount of 1 to 100 parts by weight per 100 parts by weight of the polycarboxylic acid polymer (A);
4 . The dehydrating agent (D) is methyl orthoformate and / or methyl orthoacetate,
Is preferred.

According to the present invention, it is also composed of the gas barrier material-forming composition, wherein the carboxyl group of the polycarboxylic acid polymer (A) of the gas barrier material-forming composition and the ring structure (b) of the compound (B) and the compound ( A gas barrier material is provided in which the epoxy group of C) is reacted to form a crosslinked structure.
In the gas barrier material of the present invention, it is preferable that two amide ester bonds or two ester bonds derived from an epoxycyclohexyl group are formed at the cross-linked portion in the cross-linked structure.
In the gas barrier material of the present invention, it is further preferable that metal ion bridges are formed between the remaining unreacted carboxyl groups by polyvalent metal ions.
According to the present invention, there is further provided a gas barrier material, wherein the gas barrier material is treated with water containing a polyvalent metal compound to form a metal ion bridge between the remaining unreacted carboxyl groups. A manufacturing method is provided.

According to the present invention, there is also provided a packaging material comprising the layer made of the gas barrier material provided on the surface of the plastic substrate or between the plastic layers.
In the packaging material of the present invention, it is preferable that the layer made of the gas barrier material is provided such that the surface of the plastic substrate or at least one surface is interposed between the plastic layers via the anchor layer via the anchor layer, In particular, the anchor layer preferably contains a urethane polymer.

According to the composition for forming a gas barrier material of the present invention, since the compound (C) is used in addition to the compound (B), a crosslinked structure can be easily formed by heating at a lower temperature and in a shorter time. The production time and energy can be further reduced without adversely affecting the substrate, and an excellent gas barrier material can be formed with high productivity.
Further, according to the composition for forming a gas barrier material of the present invention, by adding the dehydrating agent (D), water that deactivates the compound (B) and inhibits the crosslinking reaction is removed without affecting the crosslinking reaction. It is possible to suppress the decrease in curability of the gas barrier material-forming composition and to significantly improve the storage stability. Further, among the dehydrating agent (D), by using methyl orthoformate and / or methyl orthoacetate, by-products generated by the reaction between the dehydrating agent and water are easily evaporated and disappear when forming the gas barrier material. The excellent performance of the gas barrier material of the present invention is not impaired.
The gas barrier material obtained from the composition for forming a gas barrier material of the present invention has excellent gas barrier properties and water resistance, and can achieve excellent gas barrier properties even after being placed under high-temperature wet heat conditions such as retort sterilization. It also becomes possible to impart retort resistance.
Furthermore, since the gas barrier material of the present invention is excellent in flexibility, there is no deterioration in gas barrier property due to damage of the gas barrier material, which causes a problem even when used in a flexible packaging material. It can be formed on top to form a multilayer preform, which can be further processed.
Furthermore, the gas barrier properties under high humidity conditions are significantly improved by cross-linking between unreacted carboxyl groups after cross-linking with polycarboxylic acid polymers and cross-linking agents having specific functional groups with metal ions. Is also possible.

The composition for forming a gas barrier material of the present invention comprises an ether bond formed on carbon forming a double bond between a polycarboxylic acid polymer (A) and nitrogen, and oxygen in the ether bond. It is an important feature that it consists of a compound (B) containing two ring structures (b) and a compound (C) having at least two epoxy groups.
The basic structure in which the composition for forming a gas barrier material of the present invention forms a gas barrier material has a cross-linked structure by reacting the carboxyl group of the polycarboxylic acid polymer (A) with the ring structure (b) of the compound (B). It is based on what is formed, and what forms a crosslinked structure by the reaction of the carboxyl group of the polycarboxylic acid polymer (A) and the epoxy group of the compound (C).

に示すように、ポリカルボン酸系ポリマー（Ａ）のカルボキシル基と、化合物（Ｂ）の環構造（ｂ）が反応してアミドエステルを形成し、架橋部分にアミドエステル結合が２個形成された架橋塗膜として形成されると共に、下記式（３）

に示すように、ポリカルボン酸系ポリマー（Ａ）のカルボキシル基と、化合物（Ｃ）のエポキシ基が反応して、脂環式エポキシ基由来のエステル構造が２個形成された架橋構造が形成され、これらにより優れたガスバリア性を付与することが可能となるのである。 That is, the following formula (2)

As shown in FIG. 2, the carboxyl group of the polycarboxylic acid polymer (A) and the ring structure (b) of the compound (B) reacted to form an amide ester, and two amide ester bonds were formed at the cross-linked portion. It is formed as a crosslinked coating film and has the following formula (3)

As shown in FIG. 2, the carboxyl group of the polycarboxylic acid polymer (A) and the epoxy group of the compound (C) react to form a crosslinked structure in which two ester structures derived from the alicyclic epoxy group are formed. Thus, it becomes possible to impart excellent gas barrier properties.

The reason why the gas barrier material exhibits excellent gas barrier properties is considered as follows.
i) Since the polymer as the main component is a polycarboxylic acid polymer, the carboxyl group in the side chain has a high hydrogen bondability and a strong cohesive force, so that it forms a basic structure with excellent gas barrier properties. Can do.
ii) By reacting the carboxyl group which is a polymer side chain with the ring structure (b) of the compound (B) which is a crosslinking component, an amide ester bond which is a structure effective for gas barrier properties can be formed, and the polymer side By the reaction between the carboxyl group as a chain and the epoxycyclohexyl group of the compound (C) as a crosslinking component, an ester bond having a structure effective for gas barrier properties can be formed.
iii) The ring structure (b) of the compound (B) is the minimum two necessary for cross-linking formation, and the compound (C) is also mainly bifunctional, so that the structure of the cross-linking point is difficult to spread three-dimensionally. In addition, a dense cross-linked structure excellent in gas barrier properties can be formed.
iv) Since a polycarboxylic acid-based polymer is used as the main component, unreacted carboxyl groups that have not been used for crosslinking (B) and (C) are cross-linked with metal ions to provide gas barrier properties under high humidity conditions. Can be further improved, and excellent gas barrier properties that are not impaired even under high humidity conditions can be imparted.

  Further, since the crosslinking of the polycarboxylic acid polymer (A) with the compound (B) and the compound (C) can be formed by heating at a low temperature in a short time, the influence on the plastic substrate on which the gas barrier material is to be formed is small. There is also an advantage that it is excellent in productivity.

Compound containing two ring structures (b) in which an ether bond is formed on carbon forming a double bond between the polycarboxylic acid polymer (A) and nitrogen, and oxygen in the ether bond is contained In the crosslinking reaction represented by the above formula (2) in (B), when water is present, the compound (B) is deactivated, the crosslinking reaction is inhibited, and the curability is lowered.
In the composition for forming a gas barrier material of the present invention, by adding a dehydrating agent (D) in addition to the components (A), (B) and (C), water present in the reaction system is removed, and the compound ( Inactivation of B) can be suppressed. Thereby, the storage stability of the gas barrier material-forming composition can be improved, and the compound (B) can be efficiently reacted with the polycarboxylic acid-based polymer (A) to promote the crosslinking reaction.
Here, the dehydration reaction when methyl orthoformate is used as the dehydrating agent (D) is shown. In the following formula (4), the products generated by the reaction with the dehydrating agent are methanol and methyl formate, and both of these easily evaporate under the reaction conditions of the crosslinking reaction and remain in the formed gas barrier material. Therefore, in the composition for forming a gas barrier material of the present invention, the formed gas barrier material is the same as the one not containing the dehydrating agent (D), but the crosslinked structure is formed at a lower temperature and in a shorter time. Is possible.

This is also clear from the results of Examples described later.
That is, the gas barrier material composition comprising the gas barrier material forming composition of the present invention blended with the dehydrating agent (D) and the gas barrier material forming composition not blended with the dehydrating agent cured under the same conditions. Both of the gas barrier materials (Example 1) made of the product have a considerably low methanol extraction rate (%) indicating the cured state of the coating film. However, when both are compared, Example 3 has better curability. It is clear that it is obtained.
Further, when Example 2 and Example 5 are compared with each other, the methanol extraction rate is almost the same, but Example 5 is a gas barrier material-forming composition containing a dehydrating agent, and 2,2′-bis ( The blending amount of 2-oxazoline (compound (B)) is 30% by weight.
On the other hand, Example 2 is a composition for forming a gas barrier material that does not contain a dehydrating agent, and the amount of 2,2′-bis (2-oxazoline) (compound (B)) is 60% by weight. . In Example 5, by adding 2,2′-bis (2-oxazoline) (compound (B)) and a dehydrating agent, the amount of 2,2′-bis (2-oxazoline) is smaller than that in Example 2. Almost the same methanol extraction rate can be obtained.
As a result, even if the compounding amount of the compound (B) is reduced as in Example 5, the number of effective crosslinking points formed between the molecules of the polycarboxylic acid polymer (A) is the same as in Example 2. Further, the cohesive force due to hydrogen bonding between the carboxyl groups of the polycarboxylic acid polymer (A) works more effectively, or the number of metal ion crosslinks formed between the remaining carboxyl groups increases, resulting in more moisture resistance. Therefore, it can be seen that the value of oxygen permeation measured in a high humidity environment at a temperature of 25 ° C. and a relative humidity of 80% decreases.

(Composition for forming gas barrier material)
[Polycarboxylic acid polymer (A)]
The polycarboxylic acid polymer used in the composition for forming a gas barrier material of the present invention is a homopolymer of a monomer having a carboxyl group, such as polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, and acrylic acid-methacrylic acid copolymer. Alternatively, a copolymer and a partially neutralized product thereof can be mentioned, and it is preferable to use polyacrylic acid or polymethacrylic acid.
The partially neutralized product of the polycarboxylic acid polymer can be partially neutralized with a metal hydroxide salt such as sodium hydroxide or potassium hydroxide, ammonia or the like.
Although the neutralization degree of the said partially neutralized material is not specifically limited, It is preferable that it is 30% or less by the molar ratio with respect to a carboxyl group. When the amount is larger than the above range, the hydrogen bonding property of the carboxyl group is lowered and the gas barrier property is lowered.
The “weight average molecular weight” of the polycarboxylic acid polymer is not particularly limited, but is preferably in the range of 2000 to 5,000,000, particularly 10,000 to 1,000,000.
The above-mentioned “weight average molecular weight” is measured using two separation columns, “TSK G4000PWXL” and “TSK G3000PWXL” (manufactured by Tosoh Corporation), using a 50 mmol aqueous phosphoric acid solution as an eluent and a flow rate of 1.degree. It was determined from the chromatogram and the standard polycarboxylic acid polymer calibration curve at 0 ml / min.

Moreover, it is particularly preferable that the polycarboxylic acid polymer has a water content of 15% or less. This makes it possible to produce the gas barrier material of the present invention at a lower temperature and in a shorter time in combination with the blending of the dehydrating agent (D).
In order to reduce the water content to 15% or less, a method of subjecting the polycarboxylic acid polymer to a dehydration treatment such as heating or reduced pressure can be mentioned.
For the dehydration treatment, for example, a heat treatment at a temperature of 140 to 180 ° C. for about 5 to 20 minutes is sufficient in an electric oven, and other heating means may be used. In addition, a reduced pressure or a combination of heating and reduced pressure is used. It doesn't matter.
The water content of the polycarboxylic acid polymer is determined by the Karl Fischer method. The moisture content determined by the Karl Fischer method depends on the heating conditions of the polycarboxylic acid polymer for water vaporization. If the heating condition is set to less than 200 ° C., the amount of water adsorbed to the polycarboxylic acid polymer (free water amount) can be grasped, but the water content of the polycarboxylic acid polymer, which is a high hydrogen bonding polymer, as structural water It is considered difficult to obtain the moisture content including the amount. On the other hand, if it exceeds 250 ° C., there is a risk that the polycarboxylic acid polymer will be significantly degraded, which is not preferable. Therefore, in order to obtain the water content considering both free water and structured water, 200 to 250 ° C. is considered to be a preferable range as the heating condition. The moisture content in the present invention was set to 230 ° C. under heating conditions for vaporizing water.

[Compound (B)]
In the gas barrier material forming composition of the present invention, the compound (B) used as a crosslinking agent for crosslinking the polycarboxylic acid-based polymer has an ether bond formed on carbon that forms a double bond with nitrogen. And a ring structure (b) comprising oxygen in the ether bond, that is, two ring structures having an oxoimino group having a —N═C—O— group or a ═C—O— moiety in the ring. The ring structure (b) is not limited to this, and the following ring structures can be exemplified.

に示されるような複素環であっても、環中にエーテル結合の酸素を含まない構造ではポリカルボン酸系ポリマーとアミドエステル結合を生成する架橋反応が起こらない。また、環構造が１個では架橋することができない。３個以上では架橋点の構造が３次元的に広がり、ガスバリア性に優れた緻密な架橋構造が形成できないため好ましくない。これらのことより、窒素と炭素が二重結合を形成していること、炭素がエーテル結合を形成していること、窒素との間に二重結合を形成する炭素にエーテル結合が形成されていること、それらの条件が単独で存在するだけではなく、窒素との間に二重結合を形成する炭素にエーテル結合が形成され、該エーテル結合中の酸素を含んで成る環構造（ｂ）を２個含有することが重要である。 On the other hand, the following formula

Even in the case of a heterocyclic ring as shown in (1), a crosslinking reaction that generates an amide ester bond with a polycarboxylic acid polymer does not occur in a structure that does not contain an ether-linked oxygen in the ring. Moreover, it cannot bridge | crosslink with one ring structure. When the number is three or more, the structure of the cross-linking points spreads three-dimensionally and a dense cross-linking structure having excellent gas barrier properties cannot be formed, which is not preferable. From these facts, nitrogen and carbon form a double bond, carbon forms an ether bond, and an ether bond is formed on the carbon that forms a double bond with nitrogen. In addition to the existence of these conditions alone, an ether bond is formed on the carbon that forms a double bond with nitrogen, and the ring structure (b) containing oxygen in the ether bond is converted into 2 It is important to contain them.

  The compound (B) used in the composition for forming a gas barrier material of the present invention contains two ring structures (b) as described above, and such ring structures may have two identical ring structures, A combination of different ring structures may be used, but at least one is preferably an oxazoline group or a derivative thereof.

  Examples of the compound (B) having two such ring structures (b) include, but are not limited to, 2,2'-bis (2-oxazoline), 2,2'-bis (4-methyl-2- Oxazoline), 2,2'-bis (5-methyl-2-oxazoline), 2,2'-bis (5,5'-dimethyl-2-oxazoline), 2,2'-bis (4,4,4 ', 4'-tetramethyl-2-oxazoline), 2,2'-p-phenylenebis (2-oxazoline), 2,2'-m-phenylenebis (2-oxazoline), 2,2'-o- Phenylenebis (2-oxazoline), 2,2'-p-phenylenebis (4-methyl-2-oxazoline), 2,2'-p-phenylenebis (4,4-dimethyl-2-oxazoline), 2, 2'-m-phenylenebis (4-methyl-2-oxazoline) 2,2'-m-phenylenebis (4,4'-dimethyl-2-oxazoline), 2,2'-ethylenebis (2-oxazoline), 2,2'-tetramethylenebis (2-oxazoline), 2 , 2'-hexamethylene bis (2-oxazoline), 2,2'-octamethylene bis (2-oxazoline), 2,2'-decamethylene bis (2-oxazoline), 2,2'-ethylene bis (4 -Methyl-2-oxazoline), 2,2'-tetramethylenebis (4,4-dimethyl-2-oxazoline), 2,2'-3,3'-diphenoxyethanebis (2-oxazoline), 2, Bisoxazolines such as 2'-cyclohexylenebis (2-oxazoline) and 2,2'-diphenylenebis (2-oxazoline): 2,2'-methylenebis (5,6-dihydro-4 H-1,3-oxazine), 2,2'-ethylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-propylenebis (5,6-dihydro-4H-1, 3-oxazine), 2,2'-butylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-hexamethylenebis (5,6-dihydro-4H-1,3-oxazine) 2,2'-p-phenylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2'-m-phenylenebis (5,6-dihydro-4H-1,3-oxazine) 2,2′-naphthylenebis (5,6-dihydro-4H-1,3-oxazine), 2,2′-p · p′-diphenylenebis (5,6-dihydro-4H-1,3-oxazine Bisoxazines such as).

  In the present invention, from the viewpoint of mechanical properties and coloring, it is preferable that the cross-linked portion formed by the polyacrylic acid polymer (A) and the compound (B) is formed by an aliphatic chain. Among these compounds (B), those having no aromatic ring can be preferably used, and 2,2′-bis (2-oxazoline) can be particularly preferably used.

[Compound (C) having at least two epoxy groups]
In the composition for forming a gas barrier material of the present invention, the compound (C) having at least two epoxy groups is used as a crosslinking agent for crosslinking the polycarboxylic acid polymer together with the compound (B).
In the present invention, the compound (C) used as the cross-linking agent is preferably an alicyclic epoxy resin, thereby forming an excellent gas barrier property and such a gas barrier material at a low temperature in a short time. In addition, it has excellent flexibility.
Further, among alicyclic epoxy resins, those having two epoxycyclohexyl groups in one molecule are particularly suitable, and excellent flexibility can be maintained.
That is, if one epoxycyclohexyl group is present in one molecule, sufficient flexibility cannot be obtained in the first place. On the other hand, if three or more epoxycyclohexyl groups are present in one molecule, three or more epoxycyclohexyl groups cannot be obtained. The structure of the cross-linking points spreads three-dimensionally, a dense cross-linking structure excellent in gas barrier properties cannot be formed, and the formed film becomes hard and brittle, so that the flexibility is inferior and satisfactory retort resistance is obtained. May not be possible.

  The compound (C) having at least two epoxy groups that can be particularly preferably used in the present invention is not limited to these, but in addition to the alicyclic epoxy compound represented by the formula (1), 3,4-epoxy-6-methylcyclohexyl) methyl-3,4-epoxy-6-methylcyclohexanecarboxylate, (3,4-epoxy-6-methylcyclohexyl) methyl-3,4-epoxycyclohexanecarboxylate Bis (3,4-epoxycyclohexylmethyl) adipate, bis (3,4-epoxycyclohexyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methyl Cyclohexanecarboxylate-3,4-epoxy-6-methylcyclohexanecarbox Rate, can be exemplified 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexane carboxylate.

In the present invention, from the viewpoints of mechanical properties and coloring, it is preferable that the cross-linked portion formed by the polyacrylic acid polymer (A) and the compound (C) is formed by an aliphatic chain. Among the compounds (C), those having no aromatic ring can be preferably used, and 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate can be particularly preferably used.
In addition, as a commercial item of an epoxy cyclohexyl group containing compound, Cyracure UVR-6100, Cyracure UVR-6105, Cyracure UVR-6110, Cyracure UVR-6128, Cyracure UVR-6200, Cyracure UVR-6216 (above, manufactured by Dow Chemical Co., Ltd.) , Celoxide 2021, Celoxide 2021P, Celoxide 2081, Celoxide 2083, Celoxide 2085, Epolide GT-300, Epolide GT-301, Epolide GT-302, Epolide GT-400, Epolide 401, Epolide 403 (above, Daicel Chemical Industries, Ltd.) Product), KRM-2100, KRM-2110, KRM-2199 (manufactured by Asahi Denka Kogyo Co., Ltd.) and the like.
In addition to the alicyclic epoxy compound, ethylene glycol diglycidyl ether, 1,2,5,6-diepoxyoctanol, bisphenol A diglycidyl ether, and the like can be used.

（式（５）中、Ｒ^１は水素原子又は−ＣＨ_３を表し、Ｒ^２は同一又は相異なってもよい−ＣＨ_３、−Ｃ_２Ｈ_５を表す。）
これらの脱水剤は、単独で又は２種以上併用して使用することができる。
式（５）で表される有機アルコキシ化合物として、特に加熱乾燥時に揮散し易いことから、オルト蟻酸メチル及び／又はオルト酢酸メチルを好適に使用することができる。 [Dehydrating agent (D)]
As the dehydrating agent used in the composition for forming a gas barrier material of the present invention, a known dehydrating agent can be used per se, but the following dehydrating agents can be mentioned without being limited thereto.
(I) Metal oxide or carbonized material rich in porosity in powder form; for example, synthetic silica, activated alumina, zeolite, activated carbon, etc.
(Ii) Calcium compounds having a composition such as CaSO ₄ , CaSO ₄ .1 / 2H ₂ O, CaO; for example, calcined gypsum, soluble gypsum, quick lime, etc.
(Iii) Metal alkoxides; for example, aluminum isopropylate, aluminum sec-butyrate, tetraisopropyl titanate, tetra n-butyl titanate, zirconium 2-propylate, zirconium n-butyrate, ethyl silicate, vinyltrimethoxysilane, etc. (iv) single Functional isocyanates; for example, additive TI (manufactured by Sumika Bayer Urethane Co., Ltd., trade name), etc.
(V) Organic alkoxy compounds; for example, organic alkoxy compounds represented by the following formula (5).

(In formula (5), ^{R 1} represents a hydrogen atom or -CH _3, ^{R 2} good _-CH 3 be the same or different, represents a _-C 2 _{H 5.)}
These dehydrating agents can be used alone or in combination of two or more.
As the organic alkoxy compound represented by the formula (5), methyl orthoformate and / or methyl orthoacetate can be suitably used because they are particularly easily volatilized during heating and drying.

[Preparation of Gas Barrier Material Forming Composition]
The composition for forming a gas barrier material of the present invention comprises 0.01 to 60 parts by weight, particularly 0.1 to 20 parts by weight of the compound (B) per 100 parts by weight of the polycarboxylic acid polymer (A). It is preferable to contain the compound (C) in an amount of 0.01 to 20 parts by weight, particularly 0.02 to 5 parts by weight.
In the composition for forming a gas barrier material of the present invention, depending on the types of the compound (B) and the compound (C) to be used, preparation of the composition for forming a gas barrier material can be carried out by using a solvent such as water or alcohol, water / alcohol. Etc. can be used. As described above, in order to prevent the deactivation of the compound (B), it is particularly preferable to mix the dehydrating agent (D). Therefore, the solvent used for preparing the gas barrier material forming composition is mainly composed of a solvent other than water. It is preferable that there is a solvent that requires less heat than water to volatilize. Examples of such a solvent include methanol, ethanol, isopropanol and the like, and methanol is particularly preferable. A solution of the polycarboxylic acid polymer (A) is prepared with a mixed solvent containing the alcohol, and the compounds (B), (C), and (D) may be added as they are if they are soluble in the solvent composition. .
Moreover, after adding to the solution of the said polycarboxylic acid type polymer (A), after melt | dissolving (B), (C) and (D) separately by the solvent composition which can hold | maintain a solution state, It may be added to the solution. Or after adding the solution containing (B) and (C) component to the solution of the said polycarboxylic acid type polymer (A) previously, it can prepare also by mix | blending (D) component.

In the gas barrier material forming composition of the present invention, in order to promote the reaction of the carboxyl group of the polycarboxylic acid polymer (A) with the ring structure (b) of the compound (B) and the reaction of the compound (C). Acidic or basic catalysts may be added.
Acid catalysts include monovalent acids such as acetic acid, propionic acid, ascorbic acid, benzoic acid, hydrochloric acid, paratoluenesulfonic acid, alkylbenzenesulfonic acid, sulfuric acid, sulfurous acid, phosphoric acid, phosphorous acid, hypophosphorous acid, polyphosphoric acid Examples thereof include divalent or higher acid such as acid, pyrophosphoric acid, maleic acid, itaconic acid, fumaric acid and polycarboxylic acid.
Basic catalysts include hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, barium hydroxide; ammonia; ethylamine, propylamine, butylamine, benzylamine , Monoethanolamine, neopentanolamine, 2-aminopropanol, 3-aminopropanol and other primary monoamines; diethylamidiethanolamine, di-n- or di-iso-propanolamine, N-methylethanolamine, N- Secondary monoamines such as ethylethanolamine; Tertiary monoamines such as dimethylethanolamine, trimethylamine, triethylamine, triisopropylamine, methyldiethanolamine, dimethylaminoethanol; diethylenetri Examples thereof include polyamines such as amine, hydroxyethylaminoethylamine, ethylaminoethylamine, and methylaminopropylamine.

In addition to the above components, the composition for forming a gas barrier material of the present invention can also contain an inorganic dispersion. Such an inorganic dispersion has a function of blocking moisture from the outside and protecting the gas barrier material, and can further improve gas barrier properties and water resistance.
The inorganic dispersion may have any shape such as a spherical shape, a needle shape, a layer shape, etc., but has wettability to the polycarboxylic acid polymer (A), the compounds (B) and (C), and is a composition for forming a gas barrier material. Those that disperse well are used. In particular, from the viewpoint that water can be blocked, a silicate compound having a layered crystal structure such as water-swellable mica and clay is preferably used. These inorganic dispersions preferably have an aspect ratio of 30 or more and 5000 or less in that they are dispersed in layers and block moisture.
The content of the inorganic dispersion is preferably 5 to 100 parts by weight with respect to 100 parts by weight of the total of the polycarboxylic acid polymer (A), the compound (B) and the compound (C).

(Gas barrier material)
The gas barrier material of the present invention comprises the above-described composition for forming a gas barrier material, the type of polycarboxylic acid polymer (A), the compounds (B) and (C) used, or the coating amount of the composition for forming a gas barrier material. However, it can be produced by heating at a temperature of 60 to 140 ° C. for 1 second to 5 minutes.
The gas barrier material of the present invention can be formed into a gas barrier material by forming the above-mentioned gas barrier material-forming composition directly into a sheet or film form and heating it to form a crosslinked structure, or for the above-mentioned gas barrier material forming The composition coated on the substrate can be heated to form a crosslinked structure, and then removed from the substrate to form a single-layer gas barrier material. Further, a gas barrier layer can be formed on a plastic substrate to form a multilayer gas barrier material.

In the gas barrier material in which the crosslinked structure is formed, since unreacted carboxyl groups that have not been used for the formation of the crosslinked structure remain, in the present invention, metal ions are further interposed between the unreacted carboxyl groups. It is particularly preferable to form a cross-linkage, whereby the unreacted carboxyl group is reduced and the water resistance is remarkably improved, and an ionic cross-link structure is further introduced into the cross-link structure of the polycarboxylic acid polymer. A dense cross-linked structure is imparted, and the gas barrier properties can be significantly improved particularly under high humidity conditions.
In the metal ion crosslinking, a carboxyl group corresponding to at least an acid value of 100 mg / g KOH or more in the gas barrier material is preferably crosslinked with metal ions, and more preferably 330 mg / g KOH or more.

In order to form a metal ion bridge between the remaining unreacted carboxyl groups in the gas barrier material in which a cross-linked structure is formed, the metal ion bridge can be easily formed by treating the gas barrier material with water containing a polyvalent metal compound. A structure can be formed.
The treatment with water containing a polyvalent metal compound includes (i) immersion treatment of the gas barrier material in water containing the polyvalent metal compound, and (ii) spray treatment of the gas barrier material containing water with the polyvalent metal compound. , (Iii) Atmosphere treatment in which a gas barrier material is placed under high humidity after the treatment of (i) to (ii), (iv) Retort treatment with water containing a polyvalent metal compound (preferably the packaging material and hot water are directly And the like).

The process (iii) is a process that brings about the aging effect after the processes (i) to (ii), and enables the processes (i) to (ii) to be shortened. The treated water used in any of the above treatments (i) to (iii) may be cold water, but contains a polyvalent metal compound so that the water containing the polyvalent metal compound can easily act on the gas barrier material. The temperature of the water is set to 20 ° C. or higher, particularly 40 to 100 ° C. In the case of (i) to (ii), the processing time is preferably 1 second or longer, particularly 3 seconds to 4 days. In the case of (iii), the processing time (i) to (ii) is 0. After the treatment for 5 seconds or more, particularly 1 second to 1 hour, it is preferable to perform an atmosphere treatment in which the gas barrier material is placed under high humidity for 1 hour or more, particularly 2 hours to 14 days. In the case of the treatment (iv), the treatment temperature is 101 ° C. or higher, particularly 120 to 140 ° C., and the treatment is performed for 1 second or longer, particularly 3 seconds to 120 minutes.
Further, a gas barrier material formed from a coating solution in which a polyvalent metal compound is dissolved or dispersed in advance may be similarly treated with water or water containing a polyvalent metal compound.

The polyvalent metal ion is not particularly limited as long as the carboxyl group of the resin can be cross-linked, and is preferably divalent or more, particularly preferably 2-3 valence, preferably magnesium ion Mg ²⁺ , calcium ion Ca. Bivalent metal ions such as ²⁺ can be used.
Examples of the metal ions include alkaline earth metals (magnesium Mg, calcium Ca, strontium Sr, barium Ba, etc.), periodic table group 8 metals (iron Fe, ruthenium Ru, etc.), periodic table group 11 metals (copper Cu, etc.), Examples thereof include metal ions such as a periodic table group 12 metal (such as zinc Zn) and a periodic table group 13 metal (such as aluminum Al). Among these, as divalent metal ions, magnesium ions Mg ²⁺ , calcium ions Ca ²⁺ , strontium ions Sr ²⁺ , barium ions Ba ²⁺ , copper ions Cu ²⁺ , zinc ions Zn ^{2+ and the} like can be exemplified. Can be exemplified by ions such as aluminum ions Al ³⁺ and iron ions Fe ³⁺ . The above metal ions can be used alone or in combination of two or more. Examples of the water dissociable metal compound that is an ion source of the polyvalent metal ion include salts of metals constituting the metal ion, such as halides (for example, chlorides such as magnesium chloride and calcium chloride), hydroxides ( For example, magnesium hydroxide, calcium hydroxide, etc.), oxide (eg, magnesium oxide, calcium oxide, etc.), carbonate (eg, magnesium carbonate, calcium carbonate), inorganic acid salt, eg, perhalogenate salt (eg, Perchlorate such as magnesium perchlorate and calcium perchlorate), sulfate, sulfite (eg, magnesium sulfonate, calcium sulfonate, etc.), nitrate (eg, magnesium nitrate, calcium nitrate, etc.), hypophosphorous acid Salt, phosphite, phosphate (eg, magnesium phosphate, calcium phosphate, etc.), organic acid , For example, carboxylates (e.g., magnesium acetate, acetates such as calcium acetate and the like) and the like.
These metal compounds can be used alone or in combination of two or more. Of these compounds, the above-mentioned metal halides and hydroxides are preferred.

The polyvalent metal compound is preferably 0.125 mmol / L or more in water, more preferably 0.5 mmol / L or more, and further preferably 2.5 mmol / L or more in water.
In any case, the water containing the polyvalent metal compound is neutral to alkaline, and the unreacted carboxyl group that was not used for forming the crosslinked structure in the gas barrier material is It is preferable because it is dissociated and a metal ion bridge is easily formed.

The gas barrier material of the present invention has sufficient gas barrier performance as a packaging material for retort, and the oxygen permeation before retort (conforming to JIS K7126-1) is 1 cm ³ / m ² · day · atm (25 ° C. − Under 80% RH environment), oxygen permeation after retort is 10 cm ³ / m ² · day · atm (under 25 ° C.-80% RH environment) or less, preferably 5 cm ³ / m ² · day · atm It has excellent gas barrier properties and retort resistance as follows (under an environment of 25 ° C.-80% RH).

(Packaging material)
The packaging material of the present invention is formed by forming the gas barrier material on the surface of a plastic substrate or between plastic layers.
As a plastic substrate, a film, a sheet, a bottle, a cup, a tray, or the like, manufactured from a thermoformable thermoplastic resin by means of extrusion molding, injection molding, blow molding, stretch blow molding or press molding , Can include any packaging material such as can shape

  Suitable examples of the resin constituting the plastic substrate are low-, medium- or high-density polyethylene, linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene-copolymer, ionomer, ethylene- Olefin copolymers such as vinyl acetate copolymer and ethylene-vinyl alcohol copolymer; polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate / isophthalate, polyethylene naphthalate; nylon 6, nylon 6,6, nylon 6,10, polyamides such as metaxylylene adipamide; polystyrenes, styrene-butadiene block copolymers, styrene-acrylonitrile copolymers, styrene-butadiene-acrylonitrile copolymers (ABS resin), etc. Rene copolymers; Vinyl chloride copolymers such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymers; Acrylic copolymers such as polymethyl methacrylate and methyl methacrylate / ethyl acrylate copolymers; is there.

These thermoplastic resins may be used alone or present in the form of a blend of two or more, and the plastic substrate may be in a single layer configuration or, for example, co-melt extrusion or other lamination It may be a laminated structure of two or more layers.
Of course, the melt-moldable thermoplastic resin may contain one or more additives such as pigments, antioxidants, antistatic agents, ultraviolet absorbers, lubricants, etc. as required per 100 parts by weight of the resin. The total amount can be added in the range of 0.001 to 5.0 parts.
Also, for example, to reinforce this container, fiber reinforcement such as glass fiber, aromatic polyamide fiber, carbon fiber, pulp, cotton linter, or powder reinforcement such as carbon black, white carbon, or glass flake, One type or two or more types of flaky reinforcing materials such as aluminum flakes can be blended in a total amount of 2 to 150 parts by weight per 100 parts by weight of the thermoplastic resin. 5 to 100 parts by weight of one or more of calcium carbonate, mica, talc, kaolin, gypsum, clay, barium sulfate, alumina powder, silica powder, magnesium carbonate, etc. as a total amount per 100 parts by weight of the thermoplastic resin Even if it mix | blends according to a prescription known per se in quantity, it does not interfere.
Furthermore, with the aim of improving gas barrier properties, a prescription known per se in the amount of 5 to 100 parts by weight as a total amount of scaly inorganic fine powders such as water-swellable mica and clay per 100 parts by weight of the thermoplastic resin Can be blended according to

  According to the present invention, the gas barrier material described above can be provided on the surface of the final film, sheet, or container, or this coating can be provided in advance on a preform for molding into a container. Examples of such a preform include a bottomed or bottomless cylindrical parison for biaxial stretch blow molding, a pipe for plastic cage molding, a vacuum molding, a pressure molding, a sheet for plug assist molding, or Examples thereof include a heat seal lid and a film for bag making.

  In the packaging material of the present invention, the gas barrier material preferably has a thickness of generally 0.1 to 10 μm, particularly 0.5 to 5 μm. If this thickness is less than the above range, oxygen barrier properties may be insufficient. On the other hand, even if this thickness exceeds the above range, there is no particular advantage, and there is a tendency to be disadvantageous in terms of the cost of the packaging material. . Of course, this gas barrier material can be provided as a single layer as the inner surface of the container, the outer surface of the container, and the intermediate layer of the laminate, and as a plurality of layers, at least the inner and outer surfaces of the container or the inner and outer surfaces of the container. One can be provided as an intermediate layer of the laminate.

  Molding from the coated preform into the final container can be performed under conditions known per se such as biaxial stretch blow molding and plug assist molding. In addition, a film or sheet provided with a coating layer is bonded to another film or sheet to form a laminate, and the laminate can be used as a heat seal lid, a pouch, or a preform for container molding. .

When the gas barrier material of the present invention is used as a packaging material, it is preferable to provide an anchor layer on at least one side of the layer made of the gas barrier material, thereby further improving the adhesion between the layers, and the mechanical strength of the container. It becomes possible to increase the flexibility of the laminate. When a layer made of a gas barrier material is used for the inner and outer surfaces of the container or the outermost layer of the laminate, a layer made of the gas barrier material may be formed via an anchor layer, and when used for an intermediate layer of the laminate, the gas barrier material An anchor layer may be formed on at least one side of the layer made of.
In the packaging material of the present invention, the anchor material can be formed from various polymers such as urethane, epoxy, acrylic and polyester. It is particularly preferable to contain a urethane polymer.
The anchor material may be composed of a main agent and a curing agent, and may be a precursor in a state where the curing reaction is not completed, or may be in a state where an excessive amount of the curing agent is present. For example, in the case of urethane, it is mainly composed of a polyol component such as polyester polyol and polyether polyol and a polyisocyanate component, and the polyisocyanate component has an excess of the number of isocyanate groups than the number of hydroxyl groups in the polyol component. An isocyanate component may be present.

As the polyol component used for forming the urethane polymer, a polyester polyol is preferable. Examples of polyester polyols include polyester polyols obtained by reacting polyvalent carboxylic acids or their dialkyl esters or mixtures thereof with glycols or mixtures thereof.
Examples of the polyvalent carboxylic acid include aromatic polyvalent carboxylic acids such as isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid, and aliphatic polyvalent carboxylic acids such as adipic acid, azelaic acid, sebacic acid, and cyclohexanedicarboxylic acid.
Examples of the glycol include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, and 1,6-hexanediol.
The glass transition temperature of the polyester polyol is preferably -50 ° C to 100 ° C, more preferably -20 ° C to 80 ° C. The number average molecular weight of these polyester polyols is preferably from 1,000 to 100,000, more preferably from 3,000 to 80,000.

  Examples of the polyisocyanate used for forming the urethane polymer include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4. '-Diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate, 3,3'-dichloro- 4,4'-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, etc. Polyisocyanate, tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclohexylene diisocyanate, 4-cyclohexylene diisocyanate, hydrogenated xylylene diisocyanate, lysine diisocyanate, isophorone diisocyanate Aliphatic polyisocyanates such as 4,4′-dicyclohexylmethane diisocyanate and 3,3′-dimethyl-4,4′-dicyclohexylmethane diisocyanate, isocyanurates derived from the above polyisocyanate monomers, burettes, allophanates, etc. Polyfunctional polyisocyanate compounds or trifunctional or more functional groups such as trimethylolpropane and glycerin Polyfunctional polyisocyanate compound in the reaction containing terminal isocyanate groups obtained by the polyol compound and the like.

In the packaging material of the present invention, the anchor layer is not limited thereto. For example, the anchor layer contains polyisocyanate in an amount of 1 to 100 parts by weight, particularly 5 to 80 parts by weight, based on 100 parts by weight of the polyester polyol described above. The coating composition can be produced by heating at a temperature of 60 to 170 ° C. for 2 seconds to 5 minutes, depending on the type of polyester polyol or polyisocyanate used or the coating amount of the coating composition. it can.
In the preparation of the coating composition, each component of polyester polyol and polyisocyanate may be dissolved in a solvent such as toluene, MEK, cyclohexanone, solvesso, isophorone, xylene, ethyl acetate, butyl acetate alone or in a mixed solution. Alternatively, it can also be prepared by mixing a solution of each component. In addition to the above components, known curing accelerating catalysts, fillers, softeners, anti-aging agents, stabilizers, adhesion promoters, leveling agents, antifoaming agents, plasticizers, inorganic fillers, tackifying resins, fibers In addition, colorants such as pigments, usable time extenders, and the like can also be used.

The thickness of the anchor layer is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and still more preferably 0.1 to 3 μm. If this thickness is less than the above range, the effect of the anchor layer on adhesion may not be manifested.On the other hand, even if this thickness exceeds the above range, there is no particular advantage, and it is disadvantageous in terms of the cost of the packaging material. Tend to be.
In the packaging material of the present invention, when an anchor layer is provided to increase the adhesion between the layers, the flexibility of the laminate is further increased, and an increase in the amount of oxygen permeation after repeated bending of the laminate is suppressed. Can do.

  The present invention is further illustrated by the following examples, but the invention is not limited in any way by the following examples.

(Methanol extraction rate)
The methanol extraction rate was determined according to the following procedure.
The weight of the test plate was measured. ... (1)
The paint is applied to the test plate so that the dry film thickness is 2 μm, and the weight of the test plate is measured by heat treatment for 5 seconds at a set temperature of 100 ° C. using a conveyor type continuous drying furnace, or the set temperature is 140 ° C. Then, the weight of the test plate was measured by heat treatment for 20 seconds. ... (2)
The test plate which was immersed in 1000 ml of methanol and heated and extracted for 60 minutes under reflux was dried and weighed. ... (3)
The weight loss (%) before and after the immersion of the coating in methanol was measured according to the following formula.
Methanol extraction rate (%) = [(2) − (3) / (2) − (1)] × 100
(Oxygen transmission rate)
The oxygen transmission rate of the obtained laminate laminate of plastic films was measured using an oxygen transmission rate measurement device (manufactured by Modern Control, OX-TRAN 2/20). Moreover, the oxygen permeation amount after performing retort sterilization treatment at 120 ° C. for 30 minutes was also measured. The measurement conditions are measurement gas oxygen (100%), environmental temperature 25 ° C., and relative humidity 80%.

Example 1
Polyester polyol (Toyobo, Byron 200) was dissolved in an ethyl acetate / MEK mixed solvent (60/40 by weight) to give 20% by weight. In this solution, polyisocyanate (manufactured by Sumika Bayern Urethane, Sumidur N3300) and di-n-butyltin dilaurate (manufactured by Wako Pure Chemical Industries) are 60% by weight and 0.5% by weight, respectively, based on the polyester polyol. In addition, the mixture was diluted with the mixed solvent so that the total solid content was 14% by weight, and used as a coating liquid for forming an anchor layer.
The coating solution was applied to a biaxially stretched polyethylene terephthalate film 2 having a thickness of 12 μm with a bar coater, and then heat-treated with a conveyor-type electric oven at a set temperature of 80 ° C. and a processing time of 5 seconds. A polyethylene terephthalate film having an anchor layer 3 was obtained.
Polyacrylic acid (manufactured by Nippon Pure Chemical Co., Ltd., AC-10LHP) is used as the polycarboxylic acid polymer (A) and added to a methanol / methyl ethyl ketone mixed solvent (50/50 by weight) so that the solid content is 12% by weight. To obtain solution (I).
As a compound (B) containing an ether bond formed on a carbon forming a double bond with nitrogen and containing two ring structures (b) containing oxygen in the ether bond, 2,2′- Bis (2-oxazoline) (manufactured by Tokyo Chemical Industry Co., Ltd.) was used and dissolved in methanol to give a solution (II) having a solid content of 10% by weight.
As the compound (C) having at least two epoxy groups, Syracure UVR-6110 (manufactured by Dow Chemical Company, 3,4-epoxycyclohexylmethyl- (3,4-epoxy) cyclohexanecarboxylate) is used, and methanol / methyl ethyl ketone. It was dissolved in a mixed solvent (50/50 by weight) to obtain a solution (III) having a solid content of 10% by weight.
The solution (I) is such that the compound (B) is 5% by weight relative to the polycarboxylic acid polymer (A) and the compound (C) is 0.2% by weight relative to the polycarboxylic acid polymer (A). ), Solution (II) and solution (III) are mixed and diluted with a methanol / methyl ethyl ketone mixed solvent (50/50 by weight) so that the solid content is 8% by weight. No. It was set to 1.
The coating liquid No. 1 was applied onto the anchor layer of the polyethylene terephthalate film having the anchor layer 3 by a bar coater. The coated film is heat-treated in a conveyor type electric oven at a set temperature of 100 ° C. for a processing time of 5 seconds, or at 140 ° C. for a processing time of 20 seconds, and a barrier layer 4 having a thickness of 2 μm is formed on the anchor layer 3. It was set as the polyethylene terephthalate film which has.
Adjusting pH to 12.0 (value at 24 ° C water temperature) by adding 360 mmol (40 g) of calcium chloride to 1 L of tap water and then adding 11 g of calcium hydroxide to 1 L of tap water Then, the film was immersed for 3 seconds while stirring at 40 ° C. while stirring. Take out from the hot water, wash and dry the treatment liquid adhering to the surface, then use the coating layer as the lower layer, 2 μm thick urethane adhesive 5, 15 μm thick biaxially stretched nylon film 6, 2 μm thick urethane adhesive 7 and an unstretched polypropylene film 8 having a thickness of 70 μm were sequentially laminated to obtain a laminate 1 having a layer structure as shown in FIG.

(Example 2)
In Example 1, the addition amount of 2,2′-bis (2-oxazoline) with respect to polyacrylic acid was 60% by weight, and the addition amount of 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate was 0. A laminate was obtained in the same manner as in Example 1 except that the content was 0.05% by weight.

(Example 3)
In Example 1, methyl orthoformate (manufactured by Wako Pure Chemical Industries, Ltd.) as the dehydrating agent (D) was added to the coating solution for forming the barrier layer so as to be 30% by weight with respect to polyacrylic acid. A laminate was obtained in the same manner.

Example 4
In Example 1, the amount of 2,2′-bis (2-oxazoline) added to polyacrylic acid was 0.01 wt%, and the amount of 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate added 0.5% by weight and methyl orthoformate (manufactured by Wako Pure Chemical Industries, Ltd.) as a dehydrating agent (D) is added to the coating solution for forming the barrier layer so as to be 2% by weight with respect to polyacrylic acid. A laminate was obtained in the same manner as in Example 1.

(Example 5)
In Example 1, the amount of 2,2′-bis (2-oxazoline) added to polyacrylic acid was 30 wt%, and the amount of 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate was 0 Example 1 except that methyl orthoformate (manufactured by Wako Pure Chemical Industries, Ltd.) as a dehydrating agent (D) was added to the barrier layer-forming coating solution so as to be 10% by weight with respect to polyacrylic acid. A laminate was obtained in the same manner as above.

(Example 6)
In Example 1, the amount of 2,2′-bis (2-oxazoline) added to polyacrylic acid was 1 wt%, and the amount of 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate added was 1 Example 1 except that methyl orthoacetate (manufactured by Wako Pure Chemical Industries, Ltd.) as a dehydrating agent (D) is added to the barrier layer forming coating solution so as to be 5% by weight with respect to polyacrylic acid. Thus, a laminate was obtained.

(Example 7)
In Example 1, the amount of 2,2′-bis (2-oxazoline) added to polyacrylic acid was 10 wt%, and the amount of 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate was 0 Example 1 except that methyl orthoformate (manufactured by Wako Pure Chemical Industries, Ltd.) as a dehydrating agent (D) is added to the barrier layer forming coating solution so as to be 20% by weight with respect to polyacrylic acid. A laminate was obtained in the same manner as above.

(Example 8)
In Example 1, the compound (C) is a polyfunctional alicyclic epoxy resin of the following formula (Epolide GT-301, manufactured by Daicel Chemical Industries, Ltd.), and the amount added to polyacrylic acid is 0.2% by weight. Lamination was performed in the same manner as in Example 1 except that methyl orthoformate (manufactured by Wako Pure Chemical Industries, Ltd.) was added as a dehydrating agent (D) to the coating liquid for forming the barrier layer so as to be 30% by weight with respect to polyacrylic acid. Got the body.

Example 9
In Example 1, ethylene glycol diglycidyl ether (manufactured by Kishida Chemical Co., Ltd.) was used as the compound (C), the amount added to polyacrylic acid was 5% by weight, and methyl orthoacetate (manufactured by Wako Pure Chemical Industries, Ltd.) as the dehydrating agent (D). ) Was added to the barrier layer-forming coating solution so as to be 30% by weight with respect to polyacrylic acid, to obtain a laminate in the same manner as in Example 1.

(Example 10)
In Example 1, 0.52% by weight of 2,2′-bis (2-oxazoline) was added to polyacrylic acid, and 1,2,5,6-diepoxyoctanol was used as compound (C). A laminate was obtained in the same manner as in Example 1, except that the amount added to the polyacrylic acid was 5% by weight to the barrier layer-forming coating solution.

(Example 11)
In Example 1, 2,2′-tetramethylenebis (2-oxazoline) was used as the compound (B), the addition amount to the polyacrylic acid was 0.1% by weight, and bisphenol A glycidyl ether as the compound (C). Was used to obtain a laminate in the same manner as in Example 1 except that the amount added to the polyacrylic acid was 20% by weight to the barrier layer forming coating solution.

(Example 12)
In Example 1, a laminate was obtained in the same manner as in Example 1 except that the immersion treatment was not performed on the polyethylene terephthalate film after application of the anchor layer and the barrier layer.

(Example 13)
In Example 1, a laminate 9 as shown in FIG. 2 was applied in the same manner as in Example 1 except that the anchor layer was not applied and the barrier layer 4 was directly applied onto the biaxially stretched polyethylene terephthalate film 2 having a thickness of 12 μm. Got.

(Example 14)
In Example 1, after coating the anchor layer and the barrier layer, the barrier layer 4 is used as a surface layer, the urethane adhesive 5 having a thickness of 2 μm, the biaxially stretched nylon film 6 having a thickness of 15 μm, the urethane adhesive 7 having a thickness of 2 μm, and the thickness. A laminate 10 as shown in FIG. 3 was obtained in the same manner as in Example 1 except that 70 μm unstretched polypropylene film 8 was sequentially laminated.

(Comparative Example 1)
In Example 1, a laminate was obtained in the same manner as in Example 1 except that 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate of compound (C) was not added.

(Comparative Example 2)
In Example 1, the addition of 2,2′-bis (2-oxazoline) of compound (B) without adding 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate of compound (C) A laminate was obtained in the same manner as in Example 1 except that the amount was 50% by weight.

(Comparative Example 3)
In Example 1, a laminate was obtained in the same manner as in Example 1 except that 2,2′-bis (2-oxazoline) of the compound (B) was not added.

Table 2 shows the measurement results of the oxygen permeation amount before and after the retort treatment of the laminates obtained in the above examples and comparative examples. In any of Examples 1 to 14, good barrier performance was exhibited before and after retorting. Examples 8 to 11 are reference examples.

2 is a view showing a cross-sectional structure of a laminate produced in Example 1. FIG. It is a figure which shows the cross-section of the laminated body created in Example 13. FIG. It is a figure which shows the cross-section of the laminated body created in Example 14. FIG.

Explanation of symbols

1, 9, 10: Laminated body 2: Biaxially stretched polyethylene terephthalate film having a thickness of 12 μm 3: Anchor layer having a thickness of 0.3 μm 4: Barrier layer having a thickness of 2 μm 5, 7: Urethane adhesive having a thickness of 2 μm 6: Thickness of 15 μm Biaxially stretched nylon film 8: unstretched polypropylene film having a thickness of 70 μm

Claims (12)

Compound containing two ring structures (b) in which an ether bond is formed on carbon forming a double bond between the polycarboxylic acid polymer (A) and nitrogen, and oxygen in the ether bond is contained (B) and Ri consists compound (C) having at least two epoxy groups, said compound (B) is 2,2'-bis (2-oxazoline), wherein the compound (C) is a compound represented by the following formula (1) gas-barrier material forming composition characterized der Rukoto those represented by.

In formula, n is an integer of 1-10.   2. The compound (B) is contained in an amount of 0.01 to 60 parts by weight and the compound (C) is contained in an amount of 0.01 to 20 parts by weight per 100 parts by weight of the polycarboxylic acid polymer (A). A gas barrier material forming composition.   The composition for gas barrier material formation according to claim 1 or 2, wherein the polycarboxylic acid polymer (A) is poly (meth) acrylic acid or a partially neutralized product thereof. The composition for forming a gas barrier material according to any one of claims 1 to 3 , comprising a dehydrating agent (D) in an amount of 1 to 100 parts by weight per 100 parts by weight of the polycarboxylic acid polymer (A). The gas barrier material forming composition according to claim 4 , wherein the dehydrating agent (D) is methyl orthoformate and / or methyl orthoacetate. A ring structure (b) comprising a carboxyl group of the polycarboxylic acid polymer (A) of the gas barrier material forming composition and the compound (B), comprising the gas barrier material forming composition according to any one of claims 1 to 5. And a gas barrier material, wherein an epoxy group of the compound (C) is reacted to form a crosslinked structure. The gas barrier material according to claim 6, wherein two amide ester bonds or two ester bonds derived from an epoxycyclohexyl group are formed at a cross-linked portion in the cross-linked structure. The gas barrier material according to claim 6 or 7 , wherein metal ion bridges are formed between the remaining unreacted carboxyl groups by polyvalent metal ions. A method for producing a gas barrier material, wherein the gas barrier material according to claim 6 or 7 is treated with water containing a polyvalent metal compound to form metal ion bridges between the remaining unreacted carboxyl groups. . A layer of a gas-barrier material according to any one of claims 6 to 8, the packaging material and characterized in that it comprises between the layers of the surface or plastic of the plastic base. The packaging material according to claim 10, wherein the layer made of the gas barrier material is provided on the surface of the plastic substrate or at least one surface between the plastic layers via the anchor layer via the anchor layer. The packaging material according to claim 11, wherein the anchor layer contains a urethane-based polymer.

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