Polyurethane composition, coating composition, coating composition set, and laminate using the same

Abstract

To provide a polyurethane composition capable of achieving high oxygen barrier performance and high substrate adhesion.SOLUTION: The above problem can be solved by a polyurethane composition including a polyurethane (C) that is a reaction product of a polyol (A) and a polyisocyanate (B), and a solvent (D), wherein the polyol (A) has an oxygen-containing hydrocarbon ring that is a five-membered ring and / or a six-membered ring containing an oxygen atom in the ring, and a ring mass ratio occupied by the oxygen-containing hydrocarbon ring and an aromatic ring in the polyurethane (C) is 10% to 50%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polyurethane composition, a coating composition, a coating composition set, and a laminate using the same. [Background technology]

[0002] In recent years, various studies have been conducted on the recycling of plastic products from the perspectives of environmental measures and effective resource utilization, and there has been a particularly strong demand for material recycling in order to realize a recycling-oriented society. Among plastic products, packaging materials made of plastic films may have a multi-layer structure to meet the different performance requirements for each application, and packaging materials containing multiple types of materials are difficult to separate or sort into single materials, making material recycling difficult. Therefore, in recent years, the conversion of packaging materials to mono-materials and dealumination of packaging materials has been actively studied.

[0003] In particular, mono-material packaging materials made of polyolefin resin layers have extremely low oxygen barrier properties due to the low polarity of their polymer chains and high flexibility, making them difficult to replace existing non-mono-material packaging materials in terms of the storage stability of the contents. Therefore, barrier coating layers have been considered as an alternative to aluminum layers and vapor deposition layers.

[0004] The mechanism by which gas barrier properties are expressed is generally discussed in terms of the combination of the "solubility coefficient" and the "diffusion coefficient." The solubility coefficient is an index that indicates the solubility of gas molecules in the film (barrier coat layer), and the diffusion coefficient is an index that indicates the mobility of gas molecules based on the free volume in the film. For example, a layer with a high hydroxyl value containing many hydroxyl groups repels oxygen molecules, which are low-polar molecules, and therefore has a low solubility coefficient for oxygen molecules. Furthermore, the formation of a three-dimensional network through hydrogen bonding reduces free volume, which has the effect of lowering the diffusion coefficient. Therefore, this layer exhibits high oxygen barrier properties in low-humidity environments. On the other hand, in a high-humidity environment, highly polar water molecules bond with hydroxyl groups, reducing polarity and promoting the cleavage of hydrogen bonds, which increases the solubility coefficient and diffusion coefficient and significantly reduces the oxygen barrier properties compared to a low-humidity environment.

[0005] The presence of rings also affects the increase or decrease of these coefficients. For example, hydrocarbon rings containing oxygen atoms contribute to a decrease in the solubility coefficient for oxygen molecules due to their increased polarity, while aromatic rings with high electron density contribute to a decrease in the diffusion coefficient by hindering the movement of oxygen molecules. Furthermore, an increase in the ring mass ratio in the layer leads to a decrease in the diffusion coefficient by restricting the path of oxygen molecules due to the suppression of ring rotation, thereby improving oxygen barrier properties.

[0006] Examples of components with a high hydroxyl value include polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer resin (EVOH), sugars (monosaccharides, disaccharides, oligosaccharides, and their polyester derivatives), polysaccharides, and sugar alcohols. However, for the reasons mentioned above, all of these have the problem of reduced oxygen barrier properties in high-humidity environments, and it is desirable to reduce the diffusion coefficient by crosslinking.

[0007] For example, Patent Document 1 discloses a polyurethane resin in which sugars (sorbitol), sugar alcohols (D-sorbitol, D-mannite), and ring-free diols are crosslinked with aliphatic polyisocyanate. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4774974 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the polyurethane resin described in Patent Document 1 has a low mass ratio of rings containing oxygen atoms or aromatic rings, and also a low hydroxyl value, meaning that the solubility coefficient and diffusion coefficient are high, resulting in insufficient oxygen barrier properties and poor substrate adhesion.

[0010] Therefore, an object of the present invention is to provide a polyurethane composition that exhibits high oxygen barrier properties and high substrate adhesion. [Means for solving the problem]

[0011] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by the following embodiments, and have thus completed the present invention.

[0012] A polyurethane composition according to one embodiment of the present disclosure comprises a polyurethane (C) which is a reaction product of a polyol (A) and a polyisocyanate (B), and a solvent (D), The polyol (A) has an oxygen-containing hydrocarbon ring which is a five-membered ring and / or a six-membered ring containing an oxygen atom in the ring, In the polyurethane (C), the ring mass ratio occupied by the oxygen-containing hydrocarbon rings and aromatic rings of the polyurethane (C) calculated by the following formula 1 is 10 to 50%.

number

[0013] A polyurethane composition according to one embodiment of the present disclosure is a polyurethane composition in which the ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings of the polyol (A), calculated by the following formula 2, in the polyurethane (C) is 20 to 50%:

number

[0014] A polyurethane composition according to one embodiment of the present disclosure is the polyurethane composition described above, wherein the ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings in the polyurethane (C) is 20 to 50% based on the total weight of the polyurethane (C).

[0015] A polyurethane composition according to one embodiment of the present disclosure is the polyurethane composition described above, wherein the polyurethane (C) has a hydroxyl value of 300 to 1200 [mgKOH / g].

[0016] A polyurethane composition according to one embodiment of the present disclosure is the above polyurethane composition in which the polyisocyanate (B) has an aromatic ring.

[0017] A polyurethane composition according to one embodiment of the present disclosure is the polyurethane composition described above, in which the ratio (NCO / OH) of the total number of isocyanate groups in the polyisocyanate (B) to the total number of hydroxyl groups in the polyol (A) is 0.20 to 0.80.

[0018] A polyurethane composition according to one embodiment of the present disclosure is the polyurethane composition described above, in which the polyisocyanate (B) includes an araliphatic polyisocyanate.

[0019] A polyurethane composition according to one embodiment of the present disclosure is the above polyurethane composition, wherein the polyol (A) contains a monosaccharide and / or a disaccharide.

[0020] A polyurethane composition according to one embodiment of the present disclosure is the polyurethane composition described above, having a solid content of 5 to 30% by mass based on the total mass of the composition.

[0021] A coating composition according to one aspect of the present disclosure is characterized by using the polyurethane composition described above.

[0022] A coating composition set according to one embodiment of the present disclosure is a coating composition set (E) consisting of a coating composition set A agent and a coating composition set B agent, the coating composition set A agent comprises a polyol (A) and / or a polyurethane (C) and a solvent (DA); The coating composition set B agent contains a polyisocyanate (B) and a solvent (DB).

[0023] A laminate according to one embodiment of the present disclosure includes a polyolefin resin layer and a coating layer in this order, The coating layer is characterized in that it is formed from the coating composition.

[0024] A laminate according to one embodiment of the present disclosure includes a first polyolefin resin layer, a coating layer, an adhesive layer, and a second polyolefin resin layer in this order; the first polyolefin resin layer and the second polyolefin resin layer contain polyolefin resins containing the same repeating unit, The coating layer is characterized in that it is formed from the coating composition.

[0025] A laminate according to one embodiment of the present disclosure includes a first polyolefin resin layer, a coating layer, and a second polyolefin resin layer in this order, the first polyolefin resin layer and the second polyolefin resin layer contain polyolefin resins containing the same repeating unit, The coating layer is characterized in that it is formed from the coating composition. [Effects of the Invention]

[0026] According to the present invention, a polyurethane composition that exhibits high oxygen barrier properties and high substrate adhesion can be obtained. DETAILED DESCRIPTION OF THE INVENTION

[0027] The polyurethane composition of the present invention comprises a polyurethane (C) which is a reaction product of a polyol (A) and a polyisocyanate (B), and a solvent (D), The polyol (A) has an oxygen-containing hydrocarbon ring which is a five-membered ring and / or a six-membered ring containing an oxygen atom in the ring, In the polyurethane (C), the ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings of the polyurethane (C) calculated by the following formula 1 is 10 to 50%.

number

[0028] <<Polyurethane (C)>> The polyurethane composition of the present invention comprises a polyurethane (C) which is a reaction product of a polyol (A) and a polyisocyanate (B), and a solvent (D), The polyol (A) has an oxygen-containing hydrocarbon ring which is a five-membered ring and / or a six-membered ring containing an oxygen atom in the ring, It is important that the ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings in polyurethane (C) calculated by the following formula 1 is 10 to 50%, more preferably 20 to 50%.

number

[0029] The ring mass ratio can be determined, for example, as follows. The "ring weight" counts only the atoms that make up the ring. For a five-membered ring, it is the sum of the weights from the five atoms. The case where polyurethane (C) is obtained by reacting 12.1 parts of glucose as polyol (A) with 12.9 parts of metaxylylene diisocyanate as polyisocyanate (B) will be described. Glucose has a total molecular weight of 180, of which the molecular weight of the oxygen-containing hydrocarbon ring and aromatic ring is 76. Therefore, the molecular weight ratio of the oxygen-containing hydrocarbon ring and aromatic ring is 76 × 100 / 180 = 42%. In other words, the ring weight of polyol (A) is 12.1 × 0.42 = 5.082. Metaxylylene diisocyanate has a total molecular weight of 188, of which the molecular weight of oxygen-containing hydrocarbon rings and aromatic rings is 72. Therefore, the molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings is 72 × 100 / 188 = 38%. In other words, the ring weight of polyisocyanate (B) is 12.9 × 0.38 = 4.902. From the above, the ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings in polyurethane (C) is (5.082+4.902)×100 / (12.1+12.9)=40%.

[0030] The hydroxyl value of the polyurethane (C) is preferably 300 to 1200 [mgKOH / g], more preferably 500 to 1000 [mgKOH / g], and even more preferably 650 to 850 [mgKOH / g]. When the hydroxyl value is 300 or more, the increased polarity contributes to a decrease in the solubility coefficient for oxygen molecules, tending to improve oxygen barrier properties. When the hydroxyl value is 1000 or less, the solubility coefficient for water decreases, tending to improve oxygen barrier properties in high-humidity environments (e.g., relative humidity of 70% or more). In addition, the closer polarity to the substrate, the higher the affinity, tending to improve adhesion to the substrate.

[0031] The content of polyurethane (C) in the polyurethane composition is preferably 5% by mass to 40% by mass, more preferably 10% by mass to 30% by mass. When it is 5% by mass or more, it tends to lead to improved work efficiency and reduced residual solvent due to a shortened time required for drying the solvent. When it is 40% by mass or less, it tends to improve leveling ability on a substrate due to a reduced viscosity of the polyurethane composition.

[0032] <Polyol (A)> The polyol (A) in the present invention may be any compound having a five- and / or six-membered oxygen-containing hydrocarbon ring containing an oxygen atom within the ring. The oxygen-containing hydrocarbon ring is preferably an oxygen-containing aliphatic hydrocarbon ring, and can be selected from known polyols. Examples of the polyol (A) include polyester polyols, polycarbonate polyols, polycaprolactone polyols, polyether polyols, polyolefin polyols, acrylic polyols, silicone polyols, castor oil-based polyols, fluorine-containing polyols, sugars, and sugar alcohols, all of which have a five- and / or six-membered oxygen-containing hydrocarbon ring containing an oxygen atom within the ring. These polyols may be used alone or in combination of two or more. The polyol (A) preferably contains a saccharide from the viewpoint of decreasing the solubility coefficient due to a high hydroxyl value and decreasing the diffusion coefficient due to suppression of rotation.

[0033] (Sugars) The saccharides are compounds having a five- and / or six-membered oxygen-containing hydrocarbon ring containing an oxygen atom within the ring, such as monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Among these, it is preferable to contain monosaccharides and / or disaccharides from the viewpoint of solubility, and more preferably monosaccharides from the viewpoint of improving adhesion to the substrate by improving flexibility.

[0034] The ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings in the polyol (A) is preferably 20 to 50%. When the ring mass ratio is 20% or more, rotation is inhibited, which contributes to a decrease in the diffusion coefficient and tends to improve oxygen barrier properties. When the ring mass ratio is 50% or less, the flexibility of the polyurethane (C) tends to improve, which tends to improve adhesion to substrates. The ring mass ratio can be determined by the procedure described in the section <Polyurethane (C)>.

[0035] <Polyisocyanate (B)> The polyisocyanate (B) in the present invention can be selected from known polyisocyanates. Examples of polyisocyanates include aromatic polyisocyanates, araliphatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates. These polyisocyanates may be used alone or in combination of two or more. The polyisocyanate (B) preferably contains an aromatic polyisocyanate and / or an araliphatic polyisocyanate from the viewpoint of reducing the diffusion coefficient by inhibiting rotation, and more preferably contains an araliphatic polyisocyanate from the viewpoint of improving substrate adhesion by imparting flexibility.

[0036] Examples of aromatic polyisocyanates include diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, phenylene diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, and polymeric diphenylmethane diisocyanate (hereinafter referred to as polymeric MDI). Among these, polymeric MDI is preferred from the viewpoint of reducing the diffusion coefficient by inhibiting rotation.

[0037] Examples of aromatic aliphatic polyisocyanates include orthoxylylene diisocyanate or a mixture thereof, metaxylylene diisocyanate or a mixture thereof, paraxylylene diisocyanate or a mixture thereof, ω,ω'-diisocyanato-1,4-diethylbenzene, 1,3- or 1,4-bis(1-isocyanato-1-methylethyl)benzene or a mixture thereof, and the like. Among these, metaxylylene diisocyanate is preferably contained from the viewpoint of reducing the diffusion coefficient by inhibiting rotation and improving solubility.

[0038] Examples of aliphatic diisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methylcaproate, lysine diisocyanate, and dimer acid diisocyanate.

[0039] Examples of alicyclic diisocyanates include 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, 1,4-bis(isocyanatemethyl)cyclohexane, 1,3-bis(isocyanatemethyl)cyclohexane, and norbornene diisocyanate.

[0040] When polyol (A) and polyisocyanate (B) are blended to obtain polyurethane (C), the ratio (NCO / OH) of the total number of isocyanate groups in polyisocyanate (B) to the total number of hydroxyl groups in polyol (A) is preferably 0.20 to 0.80. When the ratio is 0.20 or more, the urethane concentration of polyurethane (C) increases, and adhesion to substrates tends to improve. When the ratio is 0.80 or less, polyurethane (C) having a high hydroxyl value can be obtained, and oxygen barrier properties tend to improve. NCO / OH is more preferably 0.25 to 0.75, and even more preferably 0.30 to 0.70.

[0041] <Method for producing polyurethane (C)> The polyurethane (C) can be obtained by a urethanization reaction between a polyol (A) and a polyisocyanate (B). Any reaction equipment can be used for the urethanization reaction. The polyol (A), polyisocyanate (B), and solvent (D) used in producing the polyurethane (C) can be charged in any order.

[0042] <Solvent (D)> The solvent (D) in the present invention refers to a solvent capable of dissolving or dispersing the polyol (A) and polyisocyanate (B) in the present invention. Examples of the solvent (D) include N,N-dimethylformamide, N,N-dimethylsulfoxide, N-methylpyrrolidone, alcohols, and water. The solvent (D) is preferably one which is inert to the polyisocyanate (B), and examples thereof include N,N-dimethylformamide, N,N-dimethylsulfoxide, and N-methylpyrrolidone.

[0043] <Other ingredients> The polyurethane composition of the present invention may contain components other than the polyol (A) and the polyisocyanate (B) in order to satisfy various required performance characteristics. These other components may be blended with either the polyol (A) or the polyisocyanate (B), or may be blended when the polyol (A) and the polyisocyanate (B) are mixed. The other components may be used alone or in combination of two or more. Specific examples of other components are listed below.

[0044] (Silane coupling agent) The polyurethane composition of the present invention may contain a silane coupling agent from the viewpoint of improving adhesion to metal materials such as metal foils and metal vapor deposition layers. Examples of the silane coupling agent include trialkoxysilanes having a vinyl group, such as vinyltriethoxysilane and vinyltriethoxysilane; trialkoxysilanes having an amino group, such as 3-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; and trialkoxysilanes having a glycidyl group, such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane. The content of the silane coupling agent is preferably 0.1 to 5 mass %, more preferably 0.2 to 3 mass %, based on the total solid content of the polyurethane composition. By setting it in this range, adhesion to the metal foil can be improved, which is preferable.

[0045] (phosphoric acid or phosphoric acid derivatives) The polyurethane composition of the present invention may contain phosphoric acid or a phosphoric acid derivative from the viewpoint of improving adhesion to metal materials such as metal foils and metal vapor deposition layers. The phosphoric acid may be any phosphoric acid having at least one free oxygen acid, such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, or hypophosphoric acid; or condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, or ultraphosphoric acid. Phosphoric acid derivatives include, for example, phosphoric acids partially esterified with alcohols, while leaving at least one free oxygen acid. Examples of such alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerin; and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and phloroglucinol. The content of phosphoric acid or a derivative thereof is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and particularly preferably 0.05 to 1 mass %, based on the total solid content of the polyurethane composition. By setting the content within the above range, adhesion to the metal foil can be improved, which is preferable.

[0046] (Leveling agent or defoaming agent) The polyurethane composition of the present invention may contain a leveling agent and / or an antifoaming agent to improve the appearance of the laminate. Examples of leveling agents include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, acrylic copolymer, methacrylic copolymer, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, and lecithin. Examples of the antifoaming agent include silicone resin, silicone solution, and copolymers of alkyl vinyl ether, alkyl acrylate, and alkyl methacrylate.

[0047] (Reaction accelerator) The polyurethane composition of the present invention may contain a reaction accelerator to accelerate the curing reaction. Examples of the reaction accelerator include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate; tertiary amines such as 1,8-diaza-bicyclo(5,4,0)undecene-7 and 1,5-diazabicyclo(4,3,0)nonene-5,6-dibutylamino-1,8-diazabicyclo(5,4,0)undecene-7; and reactive tertiary amines such as triethanolamine.

[0048] (additives) The polyurethane composition of the present invention may contain various additives within the range that does not impair the effects of the present invention. Examples of additives include inorganic fillers such as alumina, mica, talc, aluminum flakes, and glass flakes, layered inorganic compounds, stabilizers (antioxidants, heat stabilizers, UV absorbers, hydrolysis inhibitors, etc.), rust inhibitors, thickeners, plasticizers, antistatic agents, lubricants, antiblocking agents, colorants, fillers, crystal nucleating agents, and catalysts for adjusting the curing reaction.

[0049] <Coating layer formation> The polyurethane composition of the present invention can be applied to a substrate as a coating composition containing the polyurethane composition, and used in a laminate including a coating layer. The coating on the substrate can be achieved, for example, by known coating or printing processes such as roll coating, followed by drying the solvent at a temperature of 60 to 120°C. The polyurethane composition can also be used as a coating composition as it is. The thickness of the coating layer is preferably 0.5 to 10.0 μm, more preferably 1.0 to 6.0 μm. If it is 0.5 μm or more, the contribution of the coating layer increases, and the oxygen barrier property of the laminate tends to be improved. If it is 10.0 μm or less, the flexibility of the coating layer increases, improving adhesion, and it also tends to lead to improved work efficiency and reduced residual solvent by shortening the time required to dry the solvent.

[0050] The coating composition of the present invention may comprise a coating composition set (E) consisting of a coating composition agent A and a coating composition agent B. The coating composition agent A contains a polyol (A) and / or a polyurethane (C) and a solvent (DA), and the coating composition agent B contains a polyisocyanate (B) and a solvent (DB). When agent A contains polyurethane (C), it is preferable that polyurethane (C) has a hydroxyl group. The solvent (DA) and the solvent (DB) can be selected from the solvent (D) described above. Note that the solvent (DA) is the solvent contained in the agent A, and the solvent (DB) is the solvent contained in the agent B.

[0051] Coating composition set (E) can be used to form a laminate containing a coating layer by the method described above after mixing components A and B. When a laminate is produced using coating composition set (E), the coating layer can be cured by aging the laminate, for example, in an environment of 20 to 60°C for about 1 to 5 days.

[0052] <<Laminate manufacturing>> The laminate of the present invention has a partial structure including an optional substrate layer and the coating layer of the present invention in this order, and may further include other layers as long as the effects of the present invention are not impaired. In particular, the coating layer of the present invention is characterized by its high suitability for mono-material packaging materials due to its high adhesion to polyolefin resin layers, and polyolefin resin layers can be suitably used as the substrate layer.

[0053] The polyolefin resin layer preferably contains a polyolefin resin containing the same repeating unit, and is not particularly limited and can be appropriately selected from known polyolefin substrates such as polypropylene films and polyethylene films. When multiple polyolefin resin layers are laminated, they may be of the same type or different types. Examples of polyolefin substrates include uniaxially oriented and biaxially oriented, and raw materials include low-density polyolefins, linear low-density polyolefins, high-density polyolefins, and acid-modified polyolefins. The polyolefin substrate may be selected according to the required performance and application. In the following, the terms "substrate" and "resin layer" may be used synonymously. The polyolefin substrate may have a barrier layer formed of a vapor-deposited layer of a metal or metal oxide, and examples of such a barrier layer include vapor-deposited layers of aluminum, silica, alumina, and the like.

[0054] The thickness of the polyolefin substrate can be selected as desired. In the case of a polyolefin substrate without sealant properties, from the viewpoints of tearability, formability, and transparency, the thickness is preferably 5 to 100 μm, more preferably 10 to 50 μm, and even more preferably 10 to 50 μm. A thickness of 5 μm or more is preferred because oxygen barrier properties are improved. A thickness of 100 μm or less is preferred because tearability of the laminate is improved. In the case of a polyolefin substrate having sealant properties, from the viewpoints of tearability, formability, and transparency, the thickness is preferably 10 to 200 μm, more preferably 20 to 130 μm, and even more preferably 20 to 80 μm. A thickness of 10 μm or more is preferred because oxygen barrier properties are improved. A thickness of 200 μm or less is preferred because tearability of the laminate is improved.

[0055] In order to improve adhesion to the printing layer or adhesive layer described below, the polyolefin substrate may be subjected to surface treatments such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, etc., physical treatments such as glow discharge treatment, chemical treatments such as oxidation treatment using chemicals, treatments to form adhesive layers, primer coating layers, undercoat layers, or vapor deposition anchor coating layers, etc., and other treatments before lamination or vapor deposition. Furthermore, after the surface treatment, an inorganic vapor deposition layer may be provided, and a barrier coating layer may be further provided on the inorganic vapor deposition layer.

[0056] The polyolefin substrate can be produced by a known film-forming method. Examples of such film-forming methods include extrusion, cast molding, T-die, cutting, inflation, and multilayer co-extrusion. Furthermore, from the viewpoint of film strength, dimensional stability, and heat resistance, the polyolefin substrate can be uniaxially or biaxially stretched using, for example, a tenter system or a tubular system.

[0057] If necessary, plastic compounding agents and additives such as lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments can be added to the polyolefin base material for the purpose of improving or modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slip properties, mold releasability, flame retardancy, mildew resistance, electrical properties, strength, etc., and the amount of these additives can be arbitrarily selected depending on the purpose, as long as they do not adversely affect other properties.

[0058] The thickness of each layer can be measured from the cross section of the laminate. The method for cutting out the cross section is not particularly limited, and examples thereof include a razor, a cutter, a microtome, and an ion milling method, and may be performed after cooling with liquid nitrogen or the like. The method for measuring the thickness is not particularly limited, and examples thereof include a laser microscope, an optical microscope, and an electron microscope.

[0059] <<Adhesive layer>> When the production of the laminate of the present invention includes a lamination step, any adhesive layer can be used. The resin type of the adhesive layer is not particularly limited, and examples thereof include polyether, polyester, polyether polyurethane, and polyester polyurethane. When a polyurethane type is used, any polyisocyanate can be used. Any manufacturing method can be used for manufacturing the adhesive layer. Examples of coating methods include dry lamination and non-solvent lamination. When the laminate of the present invention includes an adhesive layer, the adhesive layer can be disposed adjacent to the coating layer of the present invention.

[0060] <<Print layer>> The laminate of the present invention may further include a printed layer, and the position of the printed layer is not particularly limited. When a polyolefin resin layer and a coating layer are sequentially included, the printed layer may be disposed between the polyolefin resin layer and the coating layer, or may be disposed on the side of the polyolefin resin layer other than the coating layer. When a first polyolefin resin layer, a coating layer, an adhesive layer, and a second polyolefin resin layer are sequentially included, the printed layer may be disposed between the first polyolefin resin layer and the coating layer, or may be disposed on the side of the first polyolefin resin layer other than the coating layer, or may be disposed between the adhesive layer and the second polyolefin resin layer. When a first polyolefin resin layer, a coating layer, and a second polyolefin resin layer are sequentially included, the printed layer may be disposed between the first polyolefin resin layer and the coating layer, or may be disposed on the side of the first polyolefin resin layer other than the coating layer, or may be disposed between the coating layer and the second polyolefin resin layer. The printed layer may also be disposed via another layer such as a primer layer. When the laminate of the present invention has a printed layer, the laminate can be produced, for example, by forming a printed layer on a polyolefin substrate, applying a coating composition onto the printed layer, and then drying the solvent. The printing layer is a layer on which any desired printed pattern such as letters, numbers, pictures, figures, symbols, designs, etc. is formed for decoration, indication of contents, indication of expiration date, indication of manufacturer, seller, etc., or for the purpose of imparting aesthetic appeal, and may be a solid printing layer that is printed all over the surface. Generally, the printed layer is formed using a printing ink containing a colorant such as a pigment or dye. Examples of printing inks include oil-based inks, water-based inks, and UV inks. Examples of printing methods include gravure coating, flexo coating, roll coating, bar coating, die coating, curtain coating, spin coating, and inkjet printing. In the printing process, air blowing, heating, drying under reduced pressure, ultraviolet irradiation, and the like may be performed as needed. The printing layer preferably has a thickness of 0.1 to 10 μm, more preferably 0.5 to 5 μm, and even more preferably 0.5 to 3 μm. The printed layer may be monochromatic or multicolored, and may have a configuration such as color ink layer / white ink layer, color ink layer / white ink layer / white ink layer, or color ink layer / color ink layer / white ink layer / white ink layer.

[0061] Examples of the structure of the laminate of the present invention are given below, but the present invention is not limited to these. Polypropylene substrate / coating layer, Polyethylene substrate / coating layer, Polypropylene base material / coating layer / adhesive layer / polypropylene base material, Polypropylene base material / coating layer / adhesive layer / polyethylene base material, Polypropylene substrate / coating layer / polypropylene substrate, Polypropylene base material / coating layer / polyethylene base material Polyethylene substrate / coating layer / adhesive layer / polypropylene substrate, Polyethylene substrate / coating layer / adhesive layer / polyethylene substrate, Polyethylene substrate / coating layer / polypropylene substrate, Polyethylene substrate / coating layer / polyethylene substrate, Polypropylene substrate / printing layer / coating layer, Polyethylene substrate / printing layer / coating layer, Polypropylene base material / printing layer / coating layer / adhesive layer / polypropylene base material, Polypropylene substrate / printing layer / coating layer / adhesive layer / polyethylene substrate, Polypropylene substrate / printing layer / coating layer / polypropylene substrate, Polypropylene base material / printing layer / coating layer / polyethylene base material Polyethylene substrate / printing layer / coating layer / adhesive layer / polypropylene substrate, Polyethylene substrate / printing layer / coating layer / adhesive layer / polyethylene substrate, Polyethylene substrate / printing layer / coating layer / polypropylene substrate, Polyethylene substrate / printing layer / coating layer / polyethylene substrate [Example]

[0062] The present invention will be specifically described below with reference to examples and comparative examples. In the examples and comparative examples, "parts" and "%" mean "parts by mass" and "% by mass" unless otherwise specified.

[0063] [Calculation method for hydroxyl value (OHV)] The hydroxyl value was calculated using known values ​​according to the following (hydroxyl value calculation formula). (Calculation formula for hydroxyl value of polyol (A)) Hydroxyl value of polyol (A) (mgKOH / g) = (number of hydroxyl groups × 56,000) / molecular weight (Calculation formula for hydroxyl value of polyurethane (C)) Hydroxyl value (mgKOH / g) of polyurethane (C) = (hydroxyl value of polyol (A) × charged amount of polyol (A)) / (charged amount of polyol (A) + charged amount of polyisocyanate (B))

[0064] [Method for measuring NCO content (mass%)] Approximately 1 g of sample was weighed into a 200 mL Erlenmeyer flask and dissolved in 10 mL of 0.5 N di-n-butylamine toluene solution and 10 mL of toluene. Next, phenolphthalein test solution was added as an indicator, and after holding for 30 seconds, the solution was titrated with 0.25 N hydrochloric acid solution until it turned pale pink. The NCO content (mass%) was calculated using the following formula (NCO content (mass%)). (Formula 3):NCO(mass%)={(ba)×4.202×F×0.25} / S where S is the amount of sample collected [g] a: Consumption of 0.25N hydrochloric acid solution [mL] b: Amount of 0.25N hydrochloric acid solution consumed in the blank experiment [mL] F: Potency of 0.25N hydrochloric acid solution

[0065] [Measurement of thickness of each layer] The obtained laminate was used to cut out a cross section of the laminate by ion milling (JEOL Ltd., "IB-19520CCP"), and the cross section was then observed with a scanning electron microscope (JEOL Ltd., "JSM-7800F") to measure the layer thickness.

[0066] <Production of Polyurethane (C)> (Synthesis of Polyurethane (C-1)) A reaction vessel equipped with a stirrer, temperature control system, reflux condenser, dropping tank, and nitrogen gas inlet tube was charged with 12.1 parts of glucose and 75.0 parts of dimethylformamide, and the mixture was heated to 60°C while stirring under a nitrogen stream. After stirring for 3 hours, complete dissolution was confirmed. Next, 12.9 parts of metaxylylene diisocyanate was charged, the temperature was raised to 90°C, and the reaction was carried out for 3 hours to obtain a polyurethane (C-1) with a hydroxyl value of 758 mgKOH / g and a solids content of 25%.

[0067] (Synthesis of Polyurethanes (C-2 to C-11)) A urethane reaction was carried out in the same manner as in (C-1), except that the raw materials were changed to the compositions and blending ratios (parts by mass) shown in Table 1, to obtain polyurethanes (C-2 to C-11).

[0068] [Table 1]

[0069] The abbreviations and property values ​​in Table 1 are shown below. Glucose (molecular weight 180, number of functional groups 5, hydroxyl value 1556, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 42%) Fructose (molecular weight 180, number of functional groups 5, hydroxyl value 1556, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 42%) Sucrose (molecular weight 342, number of functional groups 8, hydroxyl value 1310, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 41%) Sorbitol (molecular weight 182, number of functional groups 6, hydroxyl value 1846, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 0%) 1,6-Hexanediol (molecular weight 118, number of functional groups 2, hydroxyl value 949, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 0%) mXDI: meta-xylylene diisocyanate (molecular weight 188, NCO content 44.7%, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 38%) Polymeric MDI: Polymeric diphenylmethane diisocyanate (WANNATE PM-200 manufactured by Wanhua, molecular weight 330, NCO content 30.0%, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 22%) IPDI: Isophorone diisocyanate (molecular weight 222, NCO content 37.5%, molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings 0%)

[0070] <Production of Coating Composition Set (E)> (Production of Coating Composition Set (E-1)) A reaction vessel equipped with a stirrer, temperature control system, reflux condenser, dropping tank, and nitrogen gas inlet tube was charged with 12.1 parts of glucose and 65.0 parts of dimethylformamide, and the mixture was heated to 60 °C while stirring under a nitrogen stream. After stirring for 3 hours, complete dissolution was confirmed and the mixture was cooled to room temperature to obtain coating composition set A. Next, using a separate reaction vessel, 12.9 parts of metaxylylene diisocyanate and 10.0 parts of dimethylformamide were dissolved in the same manner as coating composition set A to obtain coating composition set B. The coating composition set A and coating composition set B thus obtained were designated coating composition set (E-1).

[0071] (Production of Coating Composition Sets (E-2 to E-11)) Except for changing the raw materials to the compositions and blending ratios (parts by mass) shown in Table 2, coating composition sets (E-2 to E-11) were obtained in the same manner as (E-1).

[0072] (Production of Coating Composition Set (E-12)) A reaction vessel equipped with a stirrer, a temperature control system, a reflux condenser, a dropping tank, and a nitrogen gas inlet tube was charged with 25.0 parts of the aforementioned polyurethane (C-1) and 75.0 parts of dimethylformamide, and stirred under a nitrogen stream at room temperature for 30 minutes to obtain a coating composition set A. Subsequently, using another reaction vessel, 8.0 parts of metaxylylene diisocyanate and 24.0 parts of dimethylformamide were dissolved in the same manner as in the coating composition set A to obtain a coating composition set B. The coating composition set A and the coating composition set B thus obtained were designated as coating composition set (E-12).

[0073] (Production of Coating Composition Sets (E-13 to E-15)) Except for changing the raw materials to the compositions and blending ratios (parts by mass) shown in Table 2, a coating composition set (E-13 to E-15) was obtained in the same manner as (E-12).

[0074] [Table 2]

[0075] <Preparation of laminate> (Example 1-1) A coating composition containing polyurethane (C-1) was applied to the treated surface of a 20 μm-thick biaxially oriented polypropylene substrate (Futamura Chemical FOR, hereinafter referred to as OPP) using a bar coater, and then dried at 80°C for 10 minutes to obtain a laminate having an "OPP / coating layer" configuration. The thickness of the coating layer was in the range of 4.8 to 5.2 μm.

[0076] (Examples 2-1 to 9-1, Comparative Examples 1-1 to 2-1) A laminate was obtained in the same manner as in Example 1-1, except that the coating layers shown in Table 3 were used.

[0077] (Example 1-2) The coating layer surface of the laminate prepared in Example 1-1 opposite the polypropylene substrate was bonded to the treated surface of an unstretched polypropylene substrate (FHK2 manufactured by Futamura Chemical Co., Ltd., hereinafter referred to as CPP) using a solvent-based laminating adhesive (Tomoflex TM-569 / CAT-10L manufactured by Toyo-Morton Co., Ltd.) at room temperature using a laminator. The thickness of the adhesive layer was 3.3 to 3.7 μm. The laminate was stored in an environment of 40°C and 65% RH to harden the adhesive layer, and then removed after 72 hours to obtain a laminate with a structure of "OPP / coating layer / adhesive layer / CPP."

[0078] (Examples 2-2 to 9-2, Comparative Examples 1-2 to 2-2) A laminate was obtained in the same manner as in Example 1-2, except that the coating layers shown in Table 3 were used.

[0079] [Table 3]

[0080] Example 10 The coating composition set (E-1) was applied to the treated surface of a 20 μm-thick OPP sheet using a bar coater, and then dried at 80°C for 10 minutes to obtain a laminate having an "OPP / coating layer" configuration. At this point, the coating layer was in an uncured state. The thickness of the coating layer was in the range of 4.8 to 5.2 μm. Next, the coating layer surface of the laminate opposite the OPP was bonded to the treated surface of the CPP using a laminator in a room temperature environment. The laminate was stored in an environment of 40°C and 65% RH to harden the coating layer, and was then removed after 72 hours to obtain a laminate with a structure of "OPP / coating layer / CPP."

[0081] (Examples 11 to 22, Comparative Examples 3 to 4) A laminate was obtained in the same manner as in Example 10, except that the coating composition set (E) shown in Table 4 was used.

[0082] [Table 4]

[0083] <Evaluation of laminate> The resulting laminate was evaluated as follows, and the results are shown in Tables 3 and 4.

[0084] [Oxygen barrier properties] The obtained laminate was cut into a 10 cm square to prepare a test piece. Based on JIS K7126, the oxygen permeability [mL / m] was measured using an OX-TRAN 2 / 22 manufactured by MOCON under an environment of a temperature of 23°C and a relative humidity of 90%. 2 ·24h·atm] was measured. In the case of a laminate having a "polyolefin substrate / coating layer" configuration, the outermost coating layer surface was set facing the oxygen gas side, and in the case of a laminate having a "first polyolefin substrate / coating layer / adhesive layer / second polyolefin substrate" configuration and a "first polyolefin substrate / coating layer / second polyolefin substrate" configuration, the outermost first polyolefin substrate surface was set facing the oxygen gas side for measurement. The obtained values ​​were used to evaluate according to the following criteria. A: 100 [mL / m 2 Less than 24h atm (very good) B: 100 [mL / m 2 ·24h·atm] or more, 300[mL / m 2 Less than 24h atm (good) C: 300 [mL / m 2 ·24h·atm] or more, 500[mL / m 2 Less than 24h atm (available) D: 500 [mL / m 2 ·24h·atm] or more (unavailable)

[0085] [Adhesive strength] The resulting laminate was cut into a 15 mm wide, 300 mm long test piece. Based on JIS K6854, the T-peel strength [N / 15 mm] between the first polyolefin substrate and the second polyolefin substrate was measured using an Instron tensile tester at a temperature of 20°C and a relative humidity of 65% at a peel rate of 300 mm / min. The measurement was performed five times, and the average value was used to evaluate the results according to the following criteria. A: 1.5 [N / 15mm] or more (very good) B: Less than 1.5 [N / 15mm], 1.0 [N / 15mm] or more (good) C: Less than 1.0 [N / 15mm], 0.5 [N / 15mm] or more (usable) D: Less than 0.5 [N / 15mm] (unusable)

[0086] According to the evaluation results, the laminate of the present invention had good oxygen barrier properties and excellent adhesive strength. In particular, Examples 1-1 to 4-1, 1-2 to 4-2, and 10 to 13, in which the ring mass ratio of oxygen-containing hydrocarbon rings and aromatic rings in polyurethane (C) was 20 to 50%, were superior in oxygen barrier properties to Examples 5-1, 5-2, and 14, in which the ring mass ratio was less than 20%, due to a decrease in solubility coefficient due to improved polarity and a decrease in diffusion coefficient due to suppression of ring rotation. Furthermore, Examples 1-1 to 4-1, 1-2 to 4-2, and 10 to 13, in which the hydroxyl value of the polyurethane (C) was within the range of 650 to 850 mgKOH / g, were superior in oxygen barrier property to Examples 6-1 to 7-1, 6-2 to 7-2, 15, 16, and 19 to 22, in which the hydroxyl value was below 650, due to a decrease in the solubility coefficient resulting from improved polarity. Furthermore, Examples 1-1 to 4-1, 1-2 to 4-2, and 10 to 13, in which the hydroxyl value of the polyurethane (C) was within the range of 650 to 850 [mgKOH / g], had a lower solubility coefficient for water molecules than Examples 8-1 to 9-1, 8-2 to 9-2, 17, and 18, in which the hydroxyl value exceeded 850, and were therefore superior in oxygen barrier properties in a 90% relative humidity environment. Furthermore, in Examples 1-2 to 2-2, in which only monosaccharides were used as polyol (A), the flexibility of polyurethane (C) was higher than in Example 3-2, which contained a disaccharide, and therefore adhesion to substrates was improved and adhesive strength was superior. For the same reason, Examples 10 and 11 also had superior adhesive strength to Example 12, which contained a disaccharide. Furthermore, in Examples 1-2 to 2-2, in which an araliphatic polyisocyanate was used as the polyisocyanate (B), the flexibility of the polyurethane (C) was higher than in Example 4-2, in which an aromatic polyisocyanate was used, and therefore the adhesion to the substrate was improved and the adhesive strength was superior. For the same reason, Examples 10 and 11 were superior to Example 13 in adhesive strength. Furthermore, in Examples 1-2 to 4-2, in which the hydroxyl value of the polyurethane (C) was within the range of 650 to 850 [mgKOH / g], the polarity of the polyurethane (C) was closer to the polarity of the substrate, resulting in increased affinity and superior adhesive strength compared to Examples 8-2 to 9-2, in which the hydroxyl value exceeded 850. For the same reason, Examples 10 and 11 were superior in adhesive strength to Examples 17 and 18. Furthermore, Example 19, which used only an aromatic aliphatic polyisocyanate as the polyisocyanate (B), had improved substrate adhesion and excellent adhesive strength because the flexibility of the polyurethane (C) was higher than in Examples 20 to 22, which also used an aromatic polyisocyanate.

Claims

1. The composition contains a polyurethane (C) which is a reaction product of a polyol (A) and a polyisocyanate (B), and a solvent (D), The polyol (A) has an oxygen-containing hydrocarbon ring which is a five-membered ring and / or a six-membered ring containing an oxygen atom in the ring, The polyurethane (C) is a polyurethane composition in which the ring mass ratio of oxygen-containing hydrocarbon rings and aromatic rings in polyurethane (C) calculated by the following formula 1 is 10 to 50%. [Equation 1] where: The amount of polyol (A) charged and the amount of polyisocyanate (B) charged are based on mass. The "ring content of polyol (A)" is a value calculated by multiplying the charged amount of polyol (A) by the molecular weight ratio of the oxygen-containing hydrocarbon rings and aromatic rings in the molecular weight of polyol (A), The "ring amount of polyisocyanate (B)" is a value calculated by multiplying the charged amount of polyisocyanate (B) by the molecular weight ratio of oxygen-containing hydrocarbon rings and aromatic rings in the molecular weight of polyisocyanate (B).

2. 2. The polyurethane composition according to claim 1, wherein the polyurethane (C) has a ring mass ratio of oxygen-containing hydrocarbon rings and aromatic rings of the polyol (A) calculated by the following formula 2 of 20 to 50%: [Equation 2]

3. 3. The polyurethane composition according to claim 1, wherein the ring mass ratio of the oxygen-containing hydrocarbon rings and aromatic rings in the polyurethane (C) is 20 to 50% based on the total weight of the polyurethane (C).

4. 3. The polyurethane composition according to claim 1, wherein the polyurethane (C) has a hydroxyl value of 300 to 1,200 mgKOH / g.

5. The polyurethane composition according to claim 1 or 2, wherein the polyisocyanate (B) has an aromatic ring.

6. 3. The polyurethane composition according to claim 1, wherein the ratio (NCO / OH) of the total number of isocyanate groups in the polyisocyanate (B) to the total number of hydroxyl groups in the polyol (A) is 0.20 to 0.

80.

7. The polyurethane composition of claim 5 , wherein the polyisocyanate (B) comprises an araliphatic polyisocyanate.

8. The polyurethane composition according to claim 1 or 2, wherein the polyol (A) comprises a monosaccharide and / or a disaccharide.

9. 3. The polyurethane composition according to claim 1, wherein the solid content of the polyurethane composition is 5 to 30 mass %.

10. A coating composition comprising the polyurethane composition of claim 1 or 2.

11. A coating composition set (E) for producing the coating composition according to claim 10, comprising a coating composition agent A and a coating composition agent B, The coating composition agent A contains a polyol (A) and / or a polyurethane (C) and a solvent (D-A), The coating composition set (E) includes the coating composition B agent containing a polyisocyanate (B) and a solvent (DB).

12. A polyolefin resin layer and a coating layer are included, A laminate, wherein the coating layer is formed from the coating composition according to claim 10.

13. The film has a first polyolefin resin layer, a coating layer, an adhesive layer, and a second polyolefin resin layer in this order, the first polyolefin resin layer and the second polyolefin resin layer contain polyolefin resins containing the same repeating unit, A laminate, wherein the coating layer is formed from the coating composition according to claim 10.

14. The film has a first polyolefin resin layer, a coating layer, and a second polyolefin resin layer in this order, the first polyolefin resin layer and the second polyolefin resin layer contain polyolefin resins containing the same repeating unit, A laminate, wherein the coating layer is formed from the coating composition according to claim 10.

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