JP6934349B2 - Polyhydroxyurethane resin composition, gas barrier coating agent and gas barrier film using the composition - Google Patents

Description

The present invention relates to a polyhydroxyurethane resin composition, a gas barrier coating agent using the same, and a gas barrier film. More specifically, in the present invention, the crosslinked resin film layer formed by the polyhydroxyurethane resin constituting the present invention is heat-cured in combination with a compound having two or more epoxy groups. Provided is a polyhydroxyurethane resin composition useful as a material for a gas barrier film, which is a crosslinked film having high mechanical strength and exhibits high gas barrier properties even at high temperatures without deteriorating the gas barrier properties inherent in the hydroxyurethane resin. Regarding technology. Further, since the polyhydroxyurethane resin constituting the present invention can utilize carbon dioxide as a forming raw material and can incorporate carbon dioxide into its chemical structure, the present invention can also provide a highly environmentally friendly product. Regarding industrially useful technology.

Films with gas barrier properties are mainly used for the purpose of protecting the contents, and are widely used in the field of industrial materials, mainly as packaging materials for foods and pharmaceuticals. As a material for forming the gas barrier layer for a film having a gas barrier property (hereinafter referred to as "gas barrier film"), a resin in which the formed film exhibits a gas barrier property is used. Typical resins include, for example, ethylene-vinyl alcohol copolymer resin (hereinafter abbreviated as EVOH) and vinylidene chloride resin (hereinafter abbreviated as PVDC). These resins having gas barrier properties can be used alone. Generally, as described below, a multilayer film is formed by using another resin material, and is used as a material for forming a gas barrier layer in the multilayer film.

For example, EVOH is used for composite films by co-extruding with a resin such as polypropylene (hereinafter abbreviated as PP), but EVOH is inferior in solubility in organic solvents, so it is a coating method. It is not suitable for producing films and coating films. On the other hand, PVDC can be molded by a coating method and can be applied to various base materials, and therefore is used as a coat film for food packaging and the like. However, since PVDC has a high chlorine content, another problem has been pointed out, such as the generation of dioxins when it is discarded (incinerated).

On the other hand, in recent years, global warming has become a problem, and studies are underway to reduce the use of petroleum-derived materials and use biomass-derived materials as polymer raw materials. For example, in polyethylene terephthalate (hereinafter abbreviated as PET) used for packaging materials, a manufacturing method using biomass-derived components has been almost established, and in polyethylene and PP, biomass-derived components can also be used. It is under consideration. However, with respect to resins such as EVOH and PVDC, which are widely used as materials for forming the barrier layer described above, it is difficult to replace them with biomass-derived components due to chemical structural problems, and the current situation is that studies have not progressed. ..

On the other hand, as a novel environment-friendly barrier material having a completely different chemical structure from the above-mentioned EVOH and PVDC, a polyhydroxyurethane resin that can be synthesized using carbon dioxide as a raw material is used as a material for forming a gas barrier layer. Has been proposed (see Patent Document 1). For example, the polyhydroxyurethane resin described in Patent Document 1 is a resin capable of dealing with environmental problems in that it has an —O—CO— bond derived from carbon dioxide in the chemical structure of the resin. Furthermore, this resin is characterized by a chemical structure having a hydroxyl group in the vicinity of the urethane bond, and the chemical structure having the hydroxyl group exhibits gas barrier properties not found in conventional polyurethane resins, according to Patent Document 1. It is specified.

Further, as a technique for using the polyhydroxyurethane resin, there is a method of cross-linking the hydroxyl group of the polyhydroxyurethane resin with a cross-linking agent exhibiting reactivity with the hydroxyl group for the purpose of improving the thermal characteristics of the formed film.

Further, as a technique relating to a polyhydroxyurethane resin, a method of allowing a secondary amino group to exist in the main chain by utilizing the difference in reactivity between a primary amino group and a secondary amino group is known, and Non-Patent Document 1 An example is shown in which a compound exhibiting reactivity with this secondary amino group is used as a cross-linking agent.

Japanese Unexamined Patent Publication No. 2012-172144

J. Polym. Sci. Part A 43 5899 2005

However, according to the study by the present inventors, the hydroxyl groups of the polyhydroxyurethane resin are crosslinked with a cross-linking agent for the purpose of improving the mechanical properties and thermal properties of the polyhydroxyurethane resin as in the above-mentioned conventional technique. In that case, there is a problem that the gas barrier property itself expressed by the hydrogen bond of the hydroxyl group of the polyhydroxyurethane resin is lowered, which is a contradictory state.

On the other hand, the technique of Non-Patent Document 1 described above in which a secondary amino group is introduced into a polyhydroxyurethane resin and crosslinked by utilizing its reactivity is based on a reaction with a special compound as an example, and other compounds. However, the study of the gas barrier property of the formed resin film, which is the subject of the present invention, and the use of the gas barrier property film using the same have not been studied at all.

Therefore, an object of the present invention is a case where a crosslinked film is formed by a gas barrier coating agent or a gas barrier film using a polyhydroxyurethane resin whose film exhibits gas barrier properties due to hydroxyl groups in the structure. In addition, the polyhydroxyurethane resin composition can improve the problem that the original gas barrier property of the polyhydroxyurethane resin is lowered, and can improve the mechanical properties and thermal properties of the gas barrier coating agent and the gas barrier film. It is to provide things. More specifically, a gas barrier coating agent or a gas barrier film using a polyvinylidene urethane resin as a material has improved mechanical properties and thermal properties, and is about the same as when a conventional material such as EVOH or PVDC is used. It is possible to realize the gas barrier property of the above, and it is possible to produce a film by a simple coating method, and provide a highly practical material that does not have problems due to chlorine during disposal (incineration) in conventional materials such as PVDC. To do.

As a result of repeated studies to solve the above-mentioned problems of the prior art, the present inventors have found a phenomenon in which the original gas barrier property of the polyhydroxyurethane resin is lowered by the prior art. Polyhydroxyurethane The present invention has found a configuration capable of improving the original gas barrier property of the cured resin film without lowering it, and improving the mechanical properties and thermal properties of the cured film of the polyhydroxyurethane resin. Has been completed.

［一般式（１）中、Ｘは、直接結合を表すか、炭素数１〜３０の脂肪族炭化水素基、炭素数４〜４０の脂環式炭化水素基又は炭素数６〜４０の芳香族炭化水素基のいずれかを表し、これらの基の構造中には、エーテル結合、アミノ結合、スルホニル結合、エステル結合、水酸基、ハロゲン原子及び繰り返し単位１〜３０の炭素数２〜６からなるポリアルキレングリコール鎖を含んでもよい。Ｙは、下記一般式（２）で示される少なくとも１つの２級アミノ基を有する構造であり、前記繰り返し単位間において、異なる構成のＹが混在していてもよい。また、２つのＺは、それぞれ独立に下記一般式（３）〜（６）のいずれかの構造を表し、同一の構造であっても異なる構造であっていてもよく、且つ、繰り返し単位間においても、同一の構造であっても異なる構造であってもよい。］

［一般式（２）中、Ｙ₁、Ｙ₂及びＹ₃は、同一でも異なっていてもよく、炭素数１〜１５の脂肪族炭化水素基、炭素数４〜１５の脂環式炭化水素基又は炭素数６〜１５の芳香族炭化水素基のいずれかを表し、該構造中には、エーテル結合、スルホニル結合、水酸基及びハロゲン原子を含んでもよい。］

［一般式（３）〜（６）中、Ｒは、水素原子又はメチル基を表し、右側の結合手は、一般式（１）中の酸素原子と結合し、左側の結合手は、一般式（１）中のＸと結合するか、該Ｘが直接結合の場合は他方のＺと結合する。］ That is, the above-mentioned problems are achieved by the following invention. The present invention comprises [1] a polyhydroxyurethane resin having a repeating unit represented by the following general formula (1) and having a secondary amino group derived from Y in the formula (1) in the main chain, and at least two. Provided is a polyhydroxyurethane resin composition comprising an epoxy compound having one epoxy group.

[In the general formula (1), X represents a direct bond, or is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 4 to 40 carbon atoms, or an aromatic group having 6 to 40 carbon atoms. Represents any of the hydrocarbon groups, and in the structure of these groups is a polyalkylene consisting of ether bonds, amino bonds, sulfonyl bonds, ester bonds, hydroxyl groups, halogen atoms and 2 to 6 carbon atoms of repeating units 1 to 30. It may contain a glycol chain. Y has a structure having at least one secondary amino group represented by the following general formula (2), and Y having different configurations may be mixed between the repeating units. Further, the two Zs independently represent any of the structures of the following general formulas (3) to (6), and may have the same structure or different structures, and between the repeating units. May have the same structure or different structures. ]

[In the general formula (2), Y ₁ , Y ₂ and Y ₃ may be the same or different, and are an aliphatic hydrocarbon group having 1 to 15 carbon atoms and an alicyclic hydrocarbon group having 4 to 15 carbon atoms. Alternatively, it represents any of an aromatic hydrocarbon group having 6 to 15 carbon atoms, and the structure may contain an ether bond, a sulfonyl bond, a hydroxyl group and a halogen atom. ]

[In the general formulas (3) to (6), R represents a hydrogen atom or a methyl group, the bond on the right side is bonded to the oxygen atom in the general formula (1), and the bond on the left side is the general formula. It binds to X in (1), or if the X is a direct bond, it binds to the other Z. ]

Preferred forms of the polyhydroxyurethane resin of the present invention include the following. [2] The polyhydroxyurethane resin having the secondary amino group in the main chain is a compound having two 5-membered cyclic carbonate structures in one molecule synthesized by using carbon dioxide as one of the raw materials. It is a polymer obtained by a double addition reaction with an amino compound containing a compound having a structure having two primary amino groups and at least one secondary amino group in one molecule, and is a whole of the polyhydroxyurethane resin. The polyhydroxyurethane resin composition according to [1], wherein the ratio of carbon dioxide-derived —O—CO— bonds to the mass is 1 to 30% by mass; [3] Further, in the general formula (1). A repeating unit in which Y is an aliphatic hydrocarbon group having 1 to 15 carbon atoms, an alicyclic hydrocarbon group having 4 to 15 carbon atoms, or an aromatic hydrocarbon group having 6 to 15 carbon atoms. The polyhydroxyurethane resin composition according to [1] or [2] in which the above is mixed can be mentioned.

Further, as another embodiment, the present invention is a gas barrier coating agent for [4] thermosetting to form a crosslinked resin film, and the polyhydroxy according to any one of [1] to [3]. Provided is a gas barrier coating agent comprising a urethane resin composition.

Further, as another embodiment, the present invention is a film composed of [5] a single layer or a multilayer, and at least one layer is a gas barrier formed by thermosetting the gas barrier coating agent according to [4]. Provided is a gas barrier film characterized by being a crosslinked resin film layer exhibiting properties.

As a preferable form of the gas barrier film of the present invention, [6] the thickness of the crosslinked resin film layer is 0.1 to 100 μm, and the oxygen permeability of the film is 23 ° C. and 65% relative humidity, constant temperature and constant humidity. and 40 ° C. even under any environment of 65% relative humidity constant temperature and humidity, and a gas barrier film according to or less ^{50ml / m 2 · 24h · atm} [5].

Although the above [2] relates to the invention of a product, "a compound having two 5-membered cyclic carbonate structures in one molecule synthesized by using carbon dioxide as one of the raw materials and two 1 in one molecule". There is a part defined by the process as "a polymer obtained by a double addition reaction with an amino compound containing a compound having a structure having a secondary amino group and at least one secondary amino group". Regarding this point, as described below, it is impossible or impractical to directly specify the product by its structure or characteristics, and there is a circumstance that it cannot be specified except by the process (manufacturing method). First, the polyhydroxyurethane resin having a secondary amino group in the main chain, which characterizes the present invention, is "a compound having two 5-membered cyclic carbonate structures in one molecule" and "two in one molecule". It can be obtained by a double addition reaction of "an amino compound containing a compound having a structure having a primary amino group and at least one secondary amino group", and the polymers obtained by this heavy addition reaction are complicated and diverse. It is common technical knowledge that a polymer has a structure and is composed of aggregates of different molecular weights, and there is a circumstance that it is impossible or impractical to directly identify the product by its structure or properties. Furthermore, as will be described later, when carbon dioxide is used as a raw material for a compound having a five-membered cyclic carbonate structure used in a polyaddition reaction, carbon dioxide is incorporated into the structure of this complex and diverse polymer. Therefore, when defining carbon dioxide in a state of being incorporated in this complex polymer structure, it is impossible to specify it except by the process described above.

Although the above [5] relates to the invention of a product, there is a part in which the product is defined by a process as "a crosslinked resin film layer having a gas barrier property formed by heat-curing a gas barrier coating agent". In this respect as well, the gas barrier coating agent is composed of a polyhydroxyurethane resin having a secondary amino group in the main chain, which characterizes the present invention, and an epoxy compound having two or more epoxy groups. The reaction product of the above-mentioned polymer composed of aggregates of different molecular weights having a complicated and diverse structure and an epoxy compound becomes one having a similarly complicated and diverse structure, and the structure or the product is formed. There are circumstances in which it is impossible or impractical to directly specify due to the characteristics, and it cannot be specified except by the process (manufacturing method).

According to the present invention, in a technique using a polyhydroxyurethane resin, which is a useful resin that can be synthesized using carbon dioxide as one of raw materials and that copes with environmental problems and that exhibits gas barrier properties by hydroxyl groups in its structure, Useful curing that can improve the problem of deterioration of gas barrier property in the cured film formed by using the resin and can realize the same level of gas barrier property as the case of using conventional materials such as EVOH and PVDC even at high temperature. A polyvinylidene urethane resin composition capable of forming a film is provided. Further, according to the present invention, by using this resin composition as a coating agent, it is possible to produce a gas barrier film having high gas barrier properties by a simple coating method, and when a conventional material is used. Provided is an excellent material with high practicality, which does not have a problem caused by chlorine generated at the time of disposal (incinerator) as in the above. More specifically, according to the present invention, the main chain contains a secondary amino group, which is useful as a material for forming a cured (crosslinked) resin film having good gas barrier properties, mechanical strength and transparency with little temperature dependence. The polyhydroxyurethane resin contained therein can be provided, and when carbon dioxide is used as one of the raw materials for the resin, it is possible to provide a material that contributes to reducing the environmental load. Further, according to the polyhydroxyurethane resin composition of the present invention, an epoxy compound in which a secondary amino group in the structure is coexisted in the composition without chemically modifying the hydroxyl group in the structure of the polyhydroxyurethane resin. Since the crosslinked resin film formed by curing by reacting with the above-mentioned function becomes a film layer, it is possible to easily provide an excellent gas barrier film by using the crosslinked resin film. Since the gas barrier film is used for containers of pharmaceuticals and foods, mechanical strength is required in addition to gas barrier property. However, in the present invention, it is possible to obtain an effect of improving mechanical strength such as breaking point strength, which is widespread. Expected to be used.

IR spectrum of the crosslinked coating film of Example 1 IR spectrum of the crosslinked coating film of Example 2 IR spectrum of the crosslinked coating film of Example 3 IR spectrum of the crosslinked coating film of Example 5

Next, the present invention will be described in more detail with reference to the best mode for carrying out the invention.
[Polyhydroxyurethane resin composition]
The polyhydroxyurethane resin composition of the present invention is characterized by containing a polyhydroxyurethane resin having a secondary amino group in the main chain having a specific repeating unit and an epoxy compound having at least two epoxy groups. .. Then, the gas barrier coating agent of the present invention using this composition is thermally cured by reacting the secondary amino group of the polyhydroxyurethane resin having a secondary amino group in the main chain with the epoxy compound. Therefore, a crosslinked resin film having excellent functionality can be formed. Specifically, the polyhydroxyurethane resin constituting the gas barrier coating agent of the present invention is characterized in that the repeating unit represented by the general formula (1) is introduced into the main chain skeleton, and is contained in the main chain skeleton structure. All or part of the secondary amino groups in the above are thermosetting by reacting with two or more epoxy groups of the epoxy compound used in combination, and as a result, a crosslinked resin film layer having sufficient gas barrier properties even at high temperatures. Can be formed. Since the crosslinked resin film layer thus formed is also excellent in mechanical strength and transparency, it can be expected to be widely used as a gas barrier film, and its practical value is extremely high.

<Polyhydroxyurethane resin having a secondary amino group in the main chain>
The polyhydroxyurethane resin constituting the present invention has a repeating unit represented by the following general formula (1), and has a secondary amino group derived from Y in the formula (1) in the main chain skeleton structure. It is characterized by having.

［一般式（１）中、Ｘは、直接結合を表すか、炭素数１〜３０の脂肪族炭化水素基、炭素数４〜４０の脂環式炭化水素基又は炭素数６〜４０の芳香族炭化水素基のいずれかを表し、これらの基の構造中には、エーテル結合、アミノ結合、スルホニル結合、エステル結合、水酸基、ハロゲン原子及び繰り返し単位１〜３０の炭素数２〜６からなるポリアルキレングリコール鎖を含んでもよい。Ｙは、下記一般式（２）で示される少なくとも１つの２級アミノ基を有する構造であり、前記繰り返し単位間において、異なる構成のＹが混在していてもよい。また、２つのＺは、それぞれ独立に下記一般式（３）〜（６）のいずれかの構造を表し、同一の構造であっても異なる構造であっていてもよく、且つ、繰り返し単位間においても、同一の構造であっても異なる構造であってもよい。］

[In the general formula (1), X represents a direct bond, or is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 4 to 40 carbon atoms, or an aromatic group having 6 to 40 carbon atoms. Represents any of the hydrocarbon groups, and in the structure of these groups is a polyalkylene consisting of ether bonds, amino bonds, sulfonyl bonds, ester bonds, hydroxyl groups, halogen atoms and 2 to 6 carbon atoms of repeating units 1 to 30. It may contain a glycol chain. Y has a structure having at least one secondary amino group represented by the following general formula (2), and Y having different configurations may be mixed between the repeating units. Further, the two Zs independently represent any of the structures of the following general formulas (3) to (6), and may have the same structure or different structures, and between the repeating units. May have the same structure or different structures. ]

［一般式（２）中、Ｙ₁、Ｙ₂及びＹ₃は、同一でも異なっていてもよく、炭素数１〜１５の脂肪族炭化水素基、炭素数４〜１５の脂環式炭化水素基又は炭素数６〜１５の芳香族炭化水素基のいずれかを表し、該構造中には、エーテル結合、スルホニル結合、水酸基及びハロゲン原子を含んでもよい。］

［一般式（３）〜（６）中、Ｒは、水素原子又はメチル基を表し、右側の結合手は、一般式（１）中の酸素原子と結合し、左側の結合手は、一般式（１）中のＸと結合するか、該Ｘが直接結合の場合は他方のＺと結合する。］

[In the general formula (2), Y ₁ , Y ₂ and Y ₃ may be the same or different, and are an aliphatic hydrocarbon group having 1 to 15 carbon atoms and an alicyclic hydrocarbon group having 4 to 15 carbon atoms. Alternatively, it represents any of an aromatic hydrocarbon group having 6 to 15 carbon atoms, and the structure may contain an ether bond, a sulfonyl bond, a hydroxyl group and a halogen atom. ]

[In the general formulas (3) to (6), R represents a hydrogen atom or a methyl group, the bond on the right side is bonded to the oxygen atom in the general formula (1), and the bond on the left side is the general formula. It binds to X in (1), or if the X is a direct bond, it binds to the other Z. ]

The polyhydroxyurethane resin constituting the present invention has an aliphatic hydrocarbon group having 1 to 15 carbon atoms and an alicyclic hydrocarbon having 4 to 15 carbon atoms in which Y in the general formula (1) is a repeating unit. A form in which a hydrocarbon group of any of a group or an aromatic hydrocarbon group having 6 to 15 carbon atoms is mixed is also preferable. With this configuration, the obtained polyhydroxyurethane resin has the minimum necessary amino groups as cross-linking points, and the formed film is appropriately provided with performance such as higher barrier properties and flexibility. Will be useful.

(Manufacturing method of polyhydroxyurethane resin having a secondary amino group in the main chain)
The method for producing a polyhydroxyurethane resin having a secondary amino group constituting the present invention in the main chain (hereinafter, also simply referred to as “polyhydroxyurethane resin”) is not particularly limited, but for example, two in one molecule. A structure having a compound having a 5-membered cyclic carbonate group (hereinafter, may be referred to as a "cyclic carbonate compound"), two primary amino groups, and one or more secondary amino groups in one molecule. It can be synthesized by utilizing the polyaddition reaction of an amino compound containing the compound (hereinafter referred to as “polyamine compound”). Specifically, when the polyhydroxyurethane resin of the present invention is produced by the above method, in order to have a secondary amino group in the main chain of the resin as an amino compound to be subjected to a heavy addition reaction with the "cyclic carbonate compound". Although it is essential to use the above-mentioned "polyamine compound", for example, a compound having two primary amino groups in one molecule (hereinafter referred to as "diamine compound") is used in combination with the "polyamine compound". May be good. Hereinafter, the raw materials and production conditions used for producing the polyhydroxyurethane resin will be described.

(Cyclic carbonate compound)
The cyclic carbonate compound used in the above-mentioned heavy addition reaction is not particularly limited, and conventionally known cyclic carbonate compounds can be used. In the present invention, as shown in the following formula, it is preferable to use a polymer synthesized by the reaction of an epoxy compound and carbon dioxide. By using such a polymer as the cyclic carbonate compound, a structure derived from carbon dioxide can be incorporated into the target polyhydroxyurethane resin. The reaction conditions of the following formula include, for example, 4 to 24 in a carbon dioxide atmosphere in which an epoxy compound as a raw material is pressurized to about atmospheric pressure to 1 MPa at a temperature of 0 ° C. to 160 ° C. in the presence of a catalyst. Reacting for about an hour can be mentioned. As a result, a cyclic carbonate compound in which carbon dioxide is immobilized on the ester moiety can be obtained.

As described above, by using the cyclic carbonate compound synthesized from carbon dioxide as a raw material for forming the resin, the urethane-bonded −O—CO— in the general formula (1) uses carbon dioxide as a raw material. It will be configured. As a result, the gas barrier coating agent of the present invention, which is made of the polyhydroxyurethane resin composition of the present invention, and the gas barrier film formed by using the gas barrier coating agent are also valuable as products capable of dealing with environmental problems. It becomes a thing. When carbon dioxide is used as a raw material for the cyclic carbonate compound as described above, the -O-CO- bond in the structure of the above-mentioned resin derived from carbon dioxide is the content of carbon dioxide of the polyhydroxyurethane resin. It accounts for 1 to 30% by mass of the total mass. It is preferable that this amount is as large as possible from the viewpoint of environmental friendliness.

As the compound having two epoxy groups in one molecule that can be used when synthesizing the "cyclic carbonate compound" which is the raw material of the above-mentioned polyhydroxyurethane resin from carbon dioxide, any conventionally known compound can be used. Preferred compounds that can be used in the present invention are illustrated below.

For example, a compound having two epoxy groups in one molecule and having a benzene skeleton and an aromatic polycyclic skeleton is exemplified in the following compounds. R in any of the following formulas is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

Further, for example, a compound having two epoxy groups in one molecule and having an aliphatic or alicyclic skeleton is exemplified in the following compounds. R in any of the following formulas is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

(Amine compound)
As described above, the polyhydroxyurethane resin having a secondary amino group constituting the present invention in the main chain has two primary amino groups and one or more secondary amino groups in one molecule as its synthetic raw material. It can be easily produced by using a "polyamine compound" which is a compound having a structure having an amino group. As the "polyamine compound", any conventionally known compound can be used. Suitable examples include, for example, diethylenetriamine, triethylenetetramine, iminobispropylamine, N, N'-bisaminopropyl-1,3-propyldiamine and N, N'-bisaminopropyl-1,3-butylenediamine. Such as chain aliphatic diamines can be mentioned.

The polyhydroxyurethane resin having a secondary amino group in the main chain constituting the present invention is a compound having two primary amino groups in one molecule together with the above-mentioned "polyamine compound" as a synthetic raw material thereof. It can be obtained by using a "diamine compound". Further, as the "diamine compound", any conventionally known compound can be used. Suitable examples include, for example, ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane, 1,10-diaminodecane and 1,12- Chain aliphatic diamines such as diaminododecane, isophorone diamines, norbornan diamines, cyclic aliphatic diamines such as 1,4-cyclohexanediamine and piperazine, aliphatic diamines having an aromatic ring such as xylene diamine, metaphenylenediamine and diaminodiphenylmethane, etc. Aromatic diamines can be mentioned.

According to the study by the present inventors, the polyhydroxyurethane resin obtained by using the above-mentioned "diamine compound" together with the "polyamine compound" has the minimum necessary amino group as a cross-linking point. , The formed film becomes a useful one that can appropriately have performance such as higher barrier property and flexibility. The amount of the "diamine compound" used is preferably, for example, about 80 mol% or less, and more preferably 50 mol% or less, based on the total amount of the polyamine compound and the diamine compound. When the amount of the diamine compound used is 80 mol% or less, the gas barrier film having the crosslinked resin film layer exhibiting the gas barrier property obtained by using the polyhydroxyurethane resin composition of the present invention has the gas barrier property at high temperature and the machine. It will be better in strength.

(Manufacturing conditions)
The specific method for producing the polyhydroxyurethane resin constituting the present invention is not particularly limited, but for example, in the presence or absence of an organic solvent, the cyclic carbonate compound as described above and the polyamine. It can be obtained by mixing the compound and, if necessary, a diamine compound, reacting at a temperature of 40 to 200 ° C. for 4 to 24 hours, and performing a polyaddition reaction.

As the solvent that can be used in the production of the above-mentioned polyhydroxyurethane resin, any organic solvent that is inert to the raw materials used and the obtained polyhydroxyurethane resin can be used. Preferred examples include, for example, methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, butyl acetate, tetrahydrofuran, dioxane, toluene, xylene, dimethylformamide, dimethylsulfoxide, perchlorethylene, trichloroethylene, methanol, ethanol. , Propanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, propylene glycol methyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether and the like.

The polyhydroxyurethane resin constituting the present invention can be produced without using a catalyst, but it can also be produced in the presence of a catalyst as described below in order to promote the reaction. In this case, for example, basic catalysts such as triethylamine, tributylamine, diazabicycloundecene (DBU), triethylenediamine (DABCO) and pyridine, Lewis acid catalysts such as tetrabutyltin and dibutyltin dilaurylate can be used. .. The preferable amount of these catalysts to be used is about 0.01 to 10 parts by mass with respect to the total amount (100 parts by mass) of the carbonate compound and the polyamine compound used and the diamine compound used as needed.

<Epoxy compound>
The polyhydroxyurethane resin composition of the present invention may be referred to as an epoxy compound having two or more epoxy groups (hereinafter, simply referred to as "epoxy compound") together with the above-mentioned polyhydroxyurethane resin having a secondary amino group in the main chain. Is). The epoxy compound is not particularly limited as long as it has at least two epoxy groups, and conventionally known ones can be used. Suitable examples include polyfunctional aliphatic glycidyl ether compounds such as 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether, and bisphenol A di. Examples thereof include polyfunctional aromatic glycidyl ether compounds such as glycidyl ether, resorcinol diglycidyl ether and N, N, N', N'-tetraglycidyl-m-xylene diamine. Further, the suitable epoxy compound used in the present invention may have two or more epoxy groups, but more preferably one having an aromatic ring in its structure.

The amount of the epoxy compound used may be determined by the amount of the epoxy group of the epoxy compound to be crosslinked with respect to the amount of the secondary amino group of the polyhydroxyurethane resin constituting the present invention. Specifically, for example, the epoxy groups may be configured so as to coexist in an amount that reacts with half to an equal amount (total amount) of the secondary amino groups in the resin. It may be appropriately determined according to the required performance in the crosslinked (cured) film formed by thermally curing the epoxy compound to be used.

〔Coating agent〕
The polyhydroxyurethane resin composition of the present invention can be used as a gas barrier coating agent. Since the polyhydroxyurethane resin composition of the present invention contains an epoxy compound together with a polyhydroxyurethane resin having a secondary amino group in the main chain, a crosslinked resin film (cured film) is formed by thermosetting these. Can be done. The formed crosslinked resin film has improved mechanical properties and thermal properties as compared with the conventional polyhydroxyurethane resin film, which does not reduce the gas barrier property inherent in the polyhydroxyurethane resin but rather improves it. become. The gas barrier coating agent of the present invention may have a structure in which the polyhydroxyurethane resin and the epoxy compound are thermally cured in a coexisting state. For example, the epoxy compound is mixed with the polyhydroxyurethane resin immediately before coating2. It may be in the form of a liquid type.

In addition to the above-mentioned polyhydroxyurethane resin and epoxy compound, the gas barrier coating agent of the present invention can contain various additives depending on the physical properties to be applied to the gas barrier layer. Specific examples of additives include weather resistance improvers, abrasion resistance improvers, cross-linking agents, infrared absorbers, antistatic agents, adhesive improvers, leveling agents, thixo-imparting agents, coupling agents, plasticizers, etc. Examples thereof include defoaming agents, fillers, solvents and coloring materials. As the weather resistance improving agent, a hindered amine-based light stabilizer (HALS), an ultraviolet absorber, an antioxidant and the like can be used as long as the curability is not impaired.

[Gas barrier film]
Next, the gas barrier film of the present invention that can be easily obtained by using the gas barrier coating agent of the present invention described above will be described. The gas barrier film of the present invention is a film composed of a single layer or multiple layers, and at least one layer is a crosslinked resin film layer exhibiting gas barrier properties formed by thermosetting the gas barrier coating agent of the present invention. It is characterized by. The crosslinked resin film layer to be formed is made of a polyhydroxyurethane resin that develops a gas barrier property by hydrogen bonding of hydroxyl groups, but solves the problem of the prior art that the gas barrier property is lowered at a high temperature. It becomes.

As a method for obtaining a gas barrier film having a structure composed of a single layer, there are the following methods. For example, by coating a release paper with a solution of a polyhydroxyurethane resin having a secondary amino group in the main chain mixed with an epoxy compound having two or more epoxy groups, and then thermosetting the resin through a drying step. There is a method of forming a crosslinked resin film to obtain a gas barrier film.

Examples of a method for obtaining a multi-layered gas barrier film in which at least one layer is a crosslinked resin film layer exhibiting gas barrier properties include a coating method and a laminating method. As a coating method, for example, a solution of the polyhydroxyurethane resin composition of the present invention (the gas barrier coating agent of the present invention) is applied onto a base material, and the mixture is heat-cured through a drying step to crosslink. Examples thereof include a method of laminating a resin film on a base material. In addition, examples of the laminating method include a method in which a gas barrier film produced as a single layer by the method described above is bonded to a base material via an adhesive.

Examples of the base material that can be used in producing the gas barrier film of the present invention include polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, fluororesin, polycarbonate, polyacetate, polyester, polyamide, and polyimide. , Polyurethane, polyvinylidene sulfide, polyallylate, polysulfone, polyethersulfone, polyether ether ketone, polyether imide and the like. Prior to coating, corona discharge treatment, plasma treatment, ozone treatment, frame treatment, primer (also called anchor coat, adhesion accelerator, easy adhesive) coating treatment, preheat treatment, dust removal treatment, etc. Easy adhesion treatment such as vapor deposition treatment and alkali treatment may be performed. Further, if necessary, additives such as fillers, colorants, plasticizers and antistatic agents may be added to the coating liquid.

In the gas barrier film of the present invention, the thickness of the crosslinked resin film layer having gas barrier property is 0.1 to 100 μm, and the oxygen permeability of the film is constant temperature and humidity of 65% relative humidity at 23 ° C and relative to 40 ° C. even under humidity of 65% of the constant temperature and humidity any environment, it is preferably not more than ^{50ml / m 2 · 24h · atm} . A film satisfying the above conditions is an excellent film in which good gas barrier properties are realized even at high temperatures and good gas barrier properties are maintained even at high temperatures. The method for measuring the oxygen permeability will be described in detail in Examples.

Next, the present invention will be described in more detail with reference to specific production examples, examples and comparative examples, but the present invention is not limited to these examples. In the following examples, "part" and "%" are based on mass unless otherwise specified.

[Production Example 1: Synthesis of cyclic carbonate-containing compound (CI)]
100 parts of bisphenol A type epoxy resin with epoxy equivalent of 187 (trade name: Epototo YD-128, manufactured by Nippon Steel & Sumitomo Metal Corporation), 20 parts of sodium iodide (manufactured by Wako Pure Chemical Industries, Ltd., the same applies hereinafter), and N- 150 parts of methyl-2-pyrrolidone was placed in a reaction vessel equipped with a stirrer and a recirculator with an air release port. Then, carbon dioxide was continuously blown with stirring, and the reaction was carried out at 100 ° C. for 10 hours. Then, 300 parts of water was added to the solution after completion of the reaction to precipitate the product, and the mixture was filtered off. The obtained white powder was recrystallized from toluene to obtain 52 parts (yield 42%) of the white powder.

When the compound obtained above was analyzed by IR (trade name: IRAfitty-1, manufactured by Shimadzu Corporation, the same device was used for the following measurements), absorption from the epoxy group of the raw material around ^{910 cm -1 (absorption from the epoxy group of the raw material around 910 cm-1).} The peak) has disappeared, and absorption (peak) derived from the carbonyl group of the carbonate group, which is not present in the raw material, was ^{confirmed around 1800 cm -1.} In addition, as a result of analysis by HPLC (trade name: LC-2000, manufactured by JASCO Corporation, column: FinePakSIL C18-T5, mobile phase: acetonitrile + water), the peak of the raw material disappeared and a new peak appeared on the highly polar side. It appeared and its purity was 98%. As a result of DSC measurement (differential scanning calorimetry), the melting point was 178 ° C, and the melting point range was ± 5 ° C. From the above, it was confirmed that this powder was a compound having a structure represented by the following formula, in which a cyclic carbonate group was introduced by a reaction between an epoxy group and carbon dioxide. This is called compound (CI). The ratio of the carbon dioxide-derived component to the obtained compound (CI) was 20.6% (calculated value from the molecular weight in the chemical structural formula).

[Production Example 2: Synthesis of cyclic carbonate-containing compound (C-II)]
A stirrer containing 100 parts of hexanediol polyglycidyl ether (trade name: Epogose-HD (D), manufactured by Yokkaichi Chemical Company Limited) having an epoxy equivalent of 116, 20 parts of sodium iodide, and 150 parts of N-methyl-2-pyrrolidone. And placed in a reaction vessel equipped with a reflux device with an air release port. Then, carbon dioxide was continuously blown with stirring, and the reaction was carried out at 100 ° C. for 10 hours. Then, 400 parts of ethyl acetate and 800 parts of water were added to the solution after completion of the reaction, and the mixture was stirred for 1 hour. Then, the ethyl acetate phase was recovered and the solvent was removed by an evaporator to obtain 127 parts (yield 92.1%) of an oily compound.

When the compound obtained above was analyzed by IR, the absorption (peak) derived from the epoxy group of the raw material near ^{910 cm -1} disappeared, while the carbonate group not present in the raw material near ^{1800 cm -1.} Absorption (peak) derived from the carbonyl group of was confirmed. Moreover, as a result of the measurement of GPC using DMF (dimethylformamide) as a mobile phase, the weight average molecular weight of the obtained substance was 318 (polyethylene oxide equivalent). From the above, it was confirmed that this substance is a compound having a structure represented by the following formula, in which a 5-membered cyclic carbonate group is introduced by a reaction between an epoxy group and carbon dioxide. This is called (C-II). The proportion of carbon dioxide-derived components in this compound (C-II) was 27.5% (calculated from the molecular weight in the chemical structural formula).

[Example 1]
42.8 parts of the cyclic carbonate-containing compound (CI) obtained in Production Example 1 in a reaction vessel equipped with a stirrer and a reflux device with an open air port, iminobispropylamine (manufactured by Koei Chemical Industry Co., Ltd.) , And 83.9 parts of N, N-dimethylformamide as a reaction solvent were added, and the reaction was carried out for 24 hours while stirring at a temperature of 80 ° C. By sampling a part of the solution after the reaction and analyzing it by IR, it was confirmed that the absorption (peak) derived from the carbonyl group of the carbonate group near ^{1800 cm -1 disappeared, and it is specified in the present invention.} A polyhydroxyurethane resin having a secondary amino group in the structure was synthesized. The weight average molecular weight of the obtained resin by GPC measurement using N, N-dimethylformamide (DMF) as a mobile phase (manufactured by Tosoh, GPC-8220; column SuperAW2500 + AW3000 + AW4000 + AW5000; also measured in the following examples) is 29000. It was (polystyrene conversion). Moreover, when the hydroxyl value was measured, it was 201 mgKOH / g with respect to the resin content.

7.6 parts (that is, the resin has) of 1,6-hexanediol diglycidyl ether (trade name: Denacol EX-212, manufactured by Nagase Chemtex) having an epoxy equivalent of 151 g / eq with respect to the resin obtained above. Add the amount of epoxy group that reacts to the secondary amino group in half), dilute this with N, N-dimethylformamide so that the total solid content becomes 40%, and apply the coating liquid (gas barrier property). Coating agent) was prepared.

A corona-treated PET film having a thickness of 25 μm was used as a base material, and the coating solution prepared above was uniformly applied onto the film by the bar coating method so that the dry film thickness was 20 μm, and the film was prepared at 80 ° C. for 5 minutes. After drying, it was cured at 120 ° C. for 10 minutes to form a crosslinked coating film (cured film of crosslinked resin). As a result of measuring the IR of the formed crosslinked coating film (resin coating film) by the ATR method (trade name: MIRacle 10, manufactured by Shimadzu Corporation, the same device is used for the following measurements), the epoxy around ^{915 cm -1.} It was confirmed that there was almost no absorption derived from the compound. FIG. 1 shows the IR spectrum of the crosslinked coating film. The hydroxyl value of the resin coating film was 221 mgKOH / g with respect to the resin content, and the ratio of the carbon dioxide-derived -O-CO- bond to the resin content was 13.9% (hydroxyl group of the coating film). The valence and CO ₂ content are calculated values from the molecular weight in the chemical structural formula, and the calculated values calculated in the same manner in the other examples below are shown). A crosslinked coating film formed on the substrate prepared above was used as an evaluation sample, and the evaluation described later was performed.

[Example 2]
In a reaction vessel equipped with a stirrer and a reflux device with an open air port, 42.8 parts of the cyclic carbonate-containing compound (CI) obtained in Production Example 1, 6.6 parts of iminobispropylamine, and , Hexamethylenediamine (manufactured by Asahi Kasei Chemicals Co., Ltd.) was added in an amount of 5.8 parts, and N, N-dimethylformamide was added in an amount of 82.7 parts as a reaction solvent, and the reaction was carried out for 24 hours while stirring at a temperature of 80 ° C. By sampling a part of the solution after the reaction and analyzing it by IR, it was confirmed that the absorption (peak) derived from the carbonyl group of the carbonate group near ^{1800 cm -1 disappeared, and it is specified in the present invention.} A polyhydroxyurethane resin having a structure having a secondary amino group was synthesized. The weight average molecular weight of the obtained resin was 28,000 (in terms of polystyrene). Moreover, when the hydroxyl value was measured, it was 203 mgKOH / g with respect to the resin content.

With respect to the resin obtained above, 7.2 parts (that is, the secondary amino group of the resin) of resorcinol diglycidyl ether (trade name: Denacol EX-201, manufactured by Nagase Chemtex) having an epoxy equivalent of 143 g / eq was added. On the other hand, the amount of the epoxy group to be reacted was equal), and this was diluted with N, N-dimethylformamide so that the total solid content was 40% to prepare a coating liquid.

A corona-treated PET film having a thickness of 25 μm is used as a base material, and the coating liquid prepared above is uniformly applied onto the film by the bar coating method so that the dry film thickness is 20 μm, and the temperature is 80 ° C. for 5 minutes. After pre-drying, it was cured at 120 ° C. for 10 minutes to form a crosslinked coating film. As a result of measuring the IR of the formed crosslinked coating film, it was confirmed that there was almost no absorption derived from the epoxy compound in the vicinity of ^{915 cm -1.} FIG. 2 shows the IR spectrum of the crosslinked coating film. The crosslinked coating film (resin coating film) prepared above was used as an evaluation sample. The hydroxyl value of the resin coating film was 225 mgKOH / g with respect to the resin content, and the ratio of the carbon dioxide-derived -O-CO- bond to the resin content was 14.1%.

[Example 3]
5.8 parts of glycerol polyglycidyl ether (trade name: Denacol EX-314, manufactured by Nagase Chemtex) having an epoxy equivalent of 115 g / eq, which is the resorcinol diglycidyl ether used in Example 2 (that is, the secondary amino contained in the resin). A crosslinked coating film was formed on the base film in the same manner as in Example 2 except that the amount of the epoxy group to be reacted was equal to that of the group. FIG. 3 shows the IR spectrum of the crosslinked coating film. The crosslinked coating film (resin coating film) prepared above was used as an evaluation sample. The hydroxyl value of the resin coating film was 230 mgKOH / g with respect to the resin content, and the ratio of the carbon dioxide-derived -O-CO- bond to the resin content was 14.4%.

[Example 4]
The 1,6-hexanediol diglycidyl ether used in Example 1 was used as an epoxy equivalent of 98 g / eq of N, N, N', N'-tetraglycidyl-m-xylene diamine (trade name: TETRAD-X, Mitsubishi Gas). On the base film in the same manner as in Example 1 except that the amount was changed to 4.9 parts (that is, the amount of the epoxy group that reacts with the secondary amino group of the resin is halved). A crosslinked coating was formed. This crosslinked coating film (resin coating film) was used as an evaluation sample. The hydroxyl value of the resin coating film was 231 mgKOH / g with respect to the resin content, and the ratio of the carbon dioxide-derived -O-CO- bond to the resin content was 14.5%.

[Example 5]
The amount of N, N, N', N'-tetraglycidyl-m-xylene diamine used in Example 4 was 9.8 parts (that is, the amount of epoxy group reacting with the secondary amino group of the resin was equal to that of the resin. A crosslinked coating film was formed on the base film in the same manner as in Example 4 except that the amount used was changed to. This crosslinked coating film (resin coating film) was used as an evaluation sample. The hydroxyl value of the obtained resin coating film was 256 mgKOH / g with respect to the resin content, and the ratio of the -O-CO- bond derived from carbon dioxide to the resin content was 13.4%. FIG. 4 shows the IR spectrum of the crosslinked coating film.

[Example 6]
5. In a reaction vessel equipped with a stirrer and a reflux device with an air opening, 42.8 parts of the cyclic carbonate-containing compound (CI) obtained in Production Example 1 and diethylenetriamine (manufactured by Koei Chemical Industry Co., Ltd.) were placed. Add 3 parts, 6.8 parts of m-xylylenediamine (manufactured by Mitsubishi Gas Chemical Company, Inc.), and 82.1 parts of N, N-dimethylformamide as a reaction solvent, and stir at a temperature of 80 ° C. for 24 hours. The reaction was carried out. By sampling a part of the solution after the reaction and analyzing it by IR, it was confirmed that the absorption (peak) derived from the carbonyl group of the carbonate group near ^{1800 cm -1 disappeared, which is specified in the present invention.} A polyhydroxyurethane resin having a structure having a secondary amino group was synthesized. The weight average molecular weight of the obtained resin was 23000 (in terms of polystyrene). Moreover, when the hydroxyl value was measured, it was 205 mgKOH / g with respect to the resin content.

7.6 parts (that is, the resin has) of 1,6-hexanediol diglycidyl ether (trade name: Denacol EX-212, manufactured by Nagase Chemtex) having an epoxy equivalent of 151 g / eq with respect to the resin obtained above. Add an equal amount of reactive epoxy group to the secondary amino group) and dilute this with N, N-dimethylformamide so that the total solid content becomes 40% to prepare a coating solution. bottom.

Then, a corona-treated PET film having a thickness of 25 μm was used as a base material, and the coating liquid prepared above was uniformly applied onto the film so that the dry film thickness was 20 μm by the bar coating method, and 5 at 80 ° C. After pre-drying for 1 minute, it was cured at 120 ° C. for 10 minutes to form a crosslinked coating film. As a result of measuring the IR of the formed crosslinked coating film, it was confirmed that there was almost no absorption derived from the epoxy compound in the vicinity of ^{915 cm -1.} This crosslinked coating film (resin coating film) was used as an evaluation sample. The hydroxyl value of the obtained resin coating film was 225 mgKOH / g with respect to the resin content, and the ratio of the -O-CO- bond derived from carbon dioxide to the resin content was 14.1%.

[Example 7]
In a reaction vessel equipped with a stirrer and a reflux device with an air opening, 32.0 parts of the cyclic carbonate-containing compound (C-II) obtained in Production Example 2, 6.6 parts of iminobispropylamine, and , 6.8 parts of m-xylylenediamine and 68.0 parts of N, N-dimethylformamide as a reaction solvent were added, and the reaction was carried out for 24 hours while stirring at a temperature of 80 ° C. By sampling a part of the solution after the reaction and analyzing it by IR, it was confirmed that the absorption (peak) derived from the carbonyl group of the carbonate group near ^{1800 cm -1 disappeared, and it is specified in the present invention.} A polyhydroxyurethane resin having a secondary amino group having a structure was synthesized. The weight average molecular weight of the obtained resin was 22000 (in terms of polystyrene). Moreover, when the hydroxyl value was measured, it was 247 mgKOH / g with respect to the resin content.

7.6 parts (that is, the resin has) of 1,6-hexanediol diglycidyl ether (trade name: Denacol EX-212, manufactured by Nagase Chemtex) having an epoxy equivalent of 151 g / eq with respect to the resin obtained above. Add an equal amount of reactive epoxy group to the secondary amino group) and dilute this with N, N-dimethylformamide so that the total solid content becomes 40% to prepare a coating solution. bottom.

A corona-treated PET film having a thickness of 25 μm is used as a base material, and the coating liquid prepared above is uniformly applied onto the film by the bar coating method so that the dry film thickness is 20 μm, and the temperature is 80 ° C. for 5 minutes. After pre-drying, it was cured at 120 ° C. for 10 minutes to form a crosslinked coating film. As a result of measuring the IR of the formed crosslinked coating film, it was confirmed that there was almost no absorption derived from the epoxy compound in the vicinity of ^{915 cm -1.} This crosslinked coating film (resin coating film) was used as an evaluation sample. The hydroxyl value of the obtained resin coating film was 265 mgKOH / g with respect to the resin content, and the ratio of the -O-CO- bond derived from carbon dioxide to the resin content was 16.6%.

[Comparative Example 1]
In a reaction vessel equipped with a stirrer and a reflux device with an air opening, 42.8 parts of the cyclic carbonate-containing compound (CI) obtained in Production Example 1, 13.1 parts of iminobispropylamine, and further. , 83.9 parts of N, N-dimethylformamide was added as a reaction solvent, and the reaction was carried out for 24 hours while stirring at a temperature of 80 ° C. By sampling a part of the solution after the reaction and analyzing it by IR, it was confirmed that the absorption (peak) derived from the carbonyl group of the carbonate group near ^{1800 cm -1 disappeared, and it is specified in the present invention.} A polyhydroxyurethane resin having a structure having a secondary amino group was synthesized. The weight average molecular weight of the obtained resin was 29,000 (in terms of polystyrene). Moreover, when the hydroxyl value was measured, it was 201 mgKOH / g with respect to the resin content.

The resin solution obtained above without an epoxy compound was used as a coating liquid, and a corona-treated PET film having a thickness of 25 μm was used as a base material, and the dry film thickness was 20 μm on this film. The prepared coating liquid is uniformly applied by the bar coating method, pre-dried at 80 ° C. for 5 minutes, and then heated at 120 ° C. for 10 minutes in the same manner as in the case of forming the crosslinked coating film performed in the example, and resin coated. A film was formed. The dry resin coating film obtained as described above was used as an evaluation sample. The ratio of the obtained dry resin coating film to the calculated carbon dioxide-derived -O-CO- bond resin content was 15.7%.

[Comparative Example 2]
The 1,6-hexanediol diglycidyl ether used in Example 1 is an epoxy compound having one epoxy group, and 6.5 parts (resin) of butyl glycidyl ether (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) having an epoxy equivalent of 130 g / eq. A resin coating film was formed in the same manner as in Example 1 except that the amount of the epoxy group to be reacted was halved with respect to the secondary amino group possessed by the above. The formed resin coating film was used as an evaluation sample. The hydroxyl value of the obtained resin coating film was 225 mgKOH / g with respect to the resin content, and the ratio of the carbon dioxide-derived -O-CO- bond to the resin content was 14.1%.

[evaluation]
Table 1 summarizes the formulations and characteristics of the resin compositions of Examples and Comparative Examples. Specifically, a cyclic carbonate compound having two or more 5-membered cyclic carbonate structures (groups) and two or more aminos used when obtaining a polyhydroxyurethane resin by the polyaddition reaction used in Examples and Comparative Examples, respectively. The raw material composition with the amino compound having a group is described by the substance amount ratio (molar ratio). Regarding the epoxy compounds used in combination with the polyhydroxyurethane resin constituting the resin compositions of Examples and Comparative Examples, Table 1 shows the epoxy groups for the secondary amino groups present in the resin, which were calculated from the epoxy equivalents. It is described by the usage amount ratio. Further, Table 1 summarizes the hydroxyl value and the ratio of carbon dioxide-derived —O—CO— to the resin molecular weight calculated from the structure of the resin coating film after cross-linking.

〔Measuring method〕
The hydroxyl value of each of the polyhydroxyurethane resins of Examples and Comparative Examples shown in Table 1, the hydroxyl value of the cured film (crosslinked coating film) of the polyhydroxyurethane resin and the epoxy compound, and the CO ₂ content are as follows. I asked for it.

<Hydroxy group value>
The hydroxyl value of the hydroxypolyurethane resin having a secondary amino group in the main chain is described as a value measured according to the measuring method of JIS K1557-1. The unit is mgKOH / g. Further, the hydroxyl value of the resin coating film after cross-linking in Table 1 is based on the assumption that all the epoxy groups of the added epoxy compound react with the secondary amino groups to generate hydroxyl groups, and the secondary amino groups are contained in the main chain. It is a calculated value added to the measured value of the hydroxyl value of the hydroxypolyurethane resin possessed by.

<CO ₂ content>
The content of CO ₂ is described by calculating the ratio of carbon dioxide-derived -O-CO- to the molecular weight of the compound. Specifically, with respect to the monomer used in the synthesis of the compound (CI) or (C-II) used in the synthesis reaction of the polyhydroxyurethane resin having a secondary amino group in the main chain. The calculated value calculated from the theoretical amount of carbon dioxide contained is shown. For example, in the case of Example 1, the carbon dioxide-derived component of the compound (CI) used was 20.6%, and from this, the carbon dioxide concentration in the solid composition of the coating liquid obtained in Example 1 was obtained. Is (42.8 parts x 20.6%) /63.4 total amount = 13.9% by mass.

[Evaluation method for the evaluation sample of the formed film]
On each evaluation film, which is an evaluation sample in which each crosslinked coating film is formed on the base film obtained in Examples 1 to 7 above, and on the base film obtained in Comparative Examples 1 and 2 above. The following items were evaluated by the following evaluation methods for the comparative evaluation films, which are the comparative evaluation samples on which the respective dry coating films were formed. The obtained evaluation results are summarized in Table 2 for Examples and Table 3 for Comparative Examples.

<Oxygen permeability>
For each film, the oxygen permeability was measured according to JIS K7126, and this was used as the evaluation of gas barrier property. It can be judged that the lower this value is, the better the gas barrier property is. Specifically, using an oxygen permeability measuring device (trade name: OX-TRAN2 / 21ML, manufactured by MOCON), the oxygen permeability of each film and the oxygen permeability of the PET film used as the base material can be determined. The measurements were taken under the conditions of a relative humidity of 23 ° C. of 65% (hereinafter referred to as 23 ° C. oxygen permeability) and a relative humidity of 40 ° C. of 65% (hereinafter referred to as 40 ° C. oxygen permeability). The oxygen permeability of the gas barrier layer is a value calculated from the measured value in consideration of the amount corresponding to the oxygen permeability of the base material. The unit is ml / m ² · day · atm, and a ^{value exceeding 500 ml / m 2} · day · atm is described as> 500. The smaller the value described, the more it can be evaluated that the coating film layer has excellent gas barrier properties.

<Temperature dependence>
The temperature dependence of the gas barrier function deterioration caused by the difference in the operating environment temperature was quantified by the following calculation method. It can be judged that the smaller this value is, the less the temperature dependence is, and the better the gas barrier property under high temperature. One object of the present invention is that the value of this temperature dependence becomes extremely close to zero.
Temperature dependence =
(Oxygen permeability at 40 ° C. relative humidity 65%)-(Oxygen permeability at 23 ° C. relative humidity 65%)

<Breaking point strength>
The mechanical strength of each film was evaluated by the breaking point strength (tensile test). The breaking point strength is measured at room temperature (25 ° C) by a measuring method using an autograph (trade name: AGS-J, manufactured by Shimadzu Corporation) in accordance with JIS K-7127. evaluated. It can be determined that the larger this value is, the higher the mechanical strength of the film is.

As shown in Table 3, in the case of Comparative Example 2 in which a resin having an increased hydroxyl group of a polyhydroxyurethane resin was used using butyl glycidyl ether, which is an epoxy compound having one epoxy group, the dry coating film was formed. Both the oxygen permeability at 23 ° C. and 40 ° C. were poor, and high gas barrier properties could not be realized.

On the other hand, in Examples 1 to 7, a crosslinked coating film was formed by curing the polyhydroxyurethane resin using the polyhydroxyurethane resin composition of the example having a configuration in which an epoxy compound having two or more epoxy groups was used in combination. In the case of the evaluation sample (evaluation film), as compared with the case where the resin of Comparative Example 1 in which the epoxy compound is not used in combination with the polyhydroxyurethane resin having the secondary amino group constituting the example in the main chain is used. As shown in Table 3, it was confirmed that the difference between the oxygen permeability at 23 ° C. and the oxygen permeability at 40 ° C. was small, and high gas barrier properties could be maintained. Since the gas barrier film is used for containers of pharmaceuticals and foods, which are extremely required to maintain the quality of stored items, it is possible to maintain the high gas barrier property shown in the evaluation film of Examples without temperature dependence. , It is extremely significant in improving the performance of these products (containers).

As described above, as an example of utilization of the polyhydroxyurethane resin composition of the present invention, a polyhydroxyurethane resin, which is a resin that can use carbon dioxide as a raw material, is used, and its practicality is further improved. A gas barrier film having a small decrease in gas barrier property under high temperature, which was difficult to do, and having excellent mechanical strength can be mentioned, and its use is expected from the viewpoint of protecting the global environment.

Claims (6)

A polyhydroxyurethane resin having a secondary amino group derived from Y in the formula (1) having a repeating unit represented by the following general formula (1) in the main chain, and a polyfunctional aliphatic glycidyl ether compound or poly. of any one selected from functional aromatic glycidyl ether compounds, and a epoxy compound having at least two epoxy groups, and, in an amount to react with half-equivalent amount of the secondary amino group with the above polyhydroxy urethane resin A polyhydroxyurethane resin composition characterized in that a crosslinked resin film can be formed by thermally curing the compound so that epoxy groups coexist.

[In the general formula (1), X represents a direct bond, or is an aliphatic hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 4 to 40 carbon atoms, or an aromatic group having 6 to 40 carbon atoms. Represents any of the hydrocarbon groups, and in the structure of these groups is a polyalkylene consisting of ether bonds, amino bonds, sulfonyl bonds, ester bonds, hydroxyl groups, halogen atoms and 2 to 6 carbon atoms of repeating units 1 to 30. It may contain a glycol chain. Y has a structure having at least one secondary amino group represented by the following general formula (2), and Y having different configurations may be mixed between the repeating units represented by the general formula (1). .. Further, the two Zs independently represent any of the structures of the following general formulas (3) to (6), and may have the same structure or different structures, and may be between repeating units. , The same structure or different structures may be used. ]

[In the general formula (2), Y ₁ , Y ₂ and Y ₃ may be the same or different, and are an aliphatic hydrocarbon group having 1 to 15 carbon atoms and an alicyclic hydrocarbon group having 4 to 15 carbon atoms. Alternatively, it represents any of an aromatic hydrocarbon group having 6 to 15 carbon atoms, and the structure may contain an ether bond, a sulfonyl bond, a hydroxyl group and a halogen atom. ]

[In the general formulas (3) to (6), R represents a hydrogen atom or a methyl group, the bond on the right side is bonded to the oxygen atom in the general formula (1), and the bond on the left side is the general formula. It binds to X in (1), or if the X is a direct bond, it binds to the other Z. ] The polyhydroxyurethane resin having the secondary amino group in the main chain is a compound having two 5-membered cyclic carbonate structures in one molecule synthesized by using carbon dioxide as one of the raw materials, and one molecule in one molecule. It is a polymer obtained by a double addition reaction of an amino compound containing a compound having a structure having two primary amino groups and at least one secondary amino group, and is added to the total mass of the polyhydroxyurethane resin. The polyhydroxyurethane resin composition according to claim 1, wherein the ratio of the -O-CO- bond derived from carbon dioxide is 1 to 30% by mass. Further, Y in the general formula (1) is an aliphatic hydrocarbon group having 1 to 15 carbon atoms, an alicyclic hydrocarbon group having 4 to 15 carbon atoms, or an aromatic hydrocarbon group having 6 to 15 carbon atoms. The polyhydroxyurethane resin composition according to claim 1 or 2, wherein the repeating unit which is any of the hydrocarbon groups is mixed. A gas barrier coating agent for forming a crosslinked resin film by thermosetting, which comprises the polyhydroxyurethane resin composition according to any one of claims 1 to 3. Coating agent. A gas barrier comprising a single layer or a multi-layer film, wherein at least one layer is a crosslinked resin film layer exhibiting gas barrier properties formed by thermosetting the gas barrier coating agent according to claim 4. Sex film. The thickness of the crosslinked resin film layer is 0.1 to 100 μm, and the oxygen transmittance of the film is 23 ° C. relative humidity 65% constant temperature constant humidity or 40 ° C. relative humidity 65% constant temperature constant humidity. gas barrier film according to claim 5 in is also less ^{50ml / m 2 · 24h · atm} .

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