Laminate, packaging film, and method for manufacturing laminate

Abstract

A laminate (1) is provided with a base material (2) and a heat seal layer (3). The heat seal layer (3) is a dried product of a coating composition. The coating composition contains a resin component composed of a copolymer of 4-methyl-1-pentene and an α-olefin (excluding 4-methyl-1-pentene) and / or a modified product of the copolymer. In the copolymer, the proportion of structural units derived from 4-methyl-1-pentene is 50 mol% or more and 99 mol% or less, and the proportion of structural units derived from the α-olefin is 1 mol% or more and 50 mol% or less, relative to the total amount of the structural units derived from 4-methyl-1-pentene and the structural units derived from the α-olefin. The oxygen transmission coefficient and the carbon dioxide transmission coefficient of the laminate are 1000 cm 3 ·mm / (m 2 ·24hr·atm) or more.

Description

Technical Field

[0001] The present invention relates to a laminate, a packaging film, and a method for manufacturing the laminate, and more specifically, to a laminate, a packaging film having the laminate, and a method for manufacturing the laminate. Background Technology

[0002] Previously, it was known that membranes formed from copolymers containing structural units derived from 4-methyl-1-pentene exhibited excellent air permeability. Therefore, such membranes are suitable for use as packaging materials, for example, fresh food.

[0003] As such a film, for example, a film has been proposed formed by casting a resin composition comprising a thermoplastic resin (A) and a thermoplastic resin (B) other than thermoplastic resin (A), wherein the thermoplastic resin (A) is a copolymer comprising structural units from 4-methyl-1-pentene and structural units from α-olefins having 2 to 20 carbon atoms, and the thermoplastic resin (B) is an olefin copolymer (see, for example, Patent Document 1).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-121322 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, membranes require both breathability and heat-sealing properties.

[0009] In Patent Document 1, from the viewpoint of improving heat sealing, a polymer other than a polymer containing structural units from 4-methyl-1-pentene (specifically thermoplastic resin (B)) is incorporated. However, if thermoplastic resin (B) is incorporated, there is a problem of reduced air permeability.

[0010] The present invention provides a laminate with excellent air permeability and heat sealing properties, a packaging film having the laminate, and a method for manufacturing the laminate.

[0011] Methods for solving problems

[0012] The present invention [1] is a laminate, which is a laminate having a substrate and a heat-sealing layer sequentially on one side facing the thickness direction. The heat-sealing layer is a dried product of the coating composition. The coating composition contains a resin component, which is composed of a copolymer of 4-methyl-1-pentene and an α-olefin (excluding 4-methyl-1-pentene) having 2 to 20 carbon atoms, and / or a modified version of the copolymer. In the copolymer, relative to the total amount of structural units from 4-methyl-1-pentene and structural units from the α-olefin, the content of structural units from 4-methyl-1-pentene is 50 mol% to 99 mol%, and the content of structural units from the α-olefin is 1 mol% to 50 mol%. The oxygen permeability and carbon dioxide permeability of the laminate are 1000 cm⁻¹. 3 ·mm / (m 2 (24hr atm) or more.

[0013] The present invention [2] includes the laminate described in [1] above, wherein the aforementioned substrate is a breathable porous substrate or a substrate formed from a polymer of 4-methyl-1-pentene.

[0014] The present invention [3] includes the laminate described in [1] or [2] above, wherein the thickness of the aforementioned heat-sealing layer is more than 1 μm and less than 50 μm.

[0015] The present invention [4] includes the laminate described in any one of [1] to [3] above, wherein the peel strength determined by the following test is 2.0 N / 15 mm or more.

[0016] Experiment: Two laminates were prepared. The two laminates were bonded together with their heat-sealed layers in contact with each other, and heat-sealed at 160°C, 0.3 MPa, and 2 seconds to produce a film. The peel strength of the film was measured by peeling it at a tensile speed of 50 mm / min and a temperature of 23°C along a direction of 180° relative to the heat-sealed surface.

[0017] The present invention [5] includes a packaging film having a laminate as described in any one of [1] to [4] above.

[0018] The present invention [6] includes a method for manufacturing a laminate as described in any one of [1] to [4] above, the method comprising the following steps: a first step of preparing the aforementioned substrate; a second step of dissolving the aforementioned coating composition in an organic solvent to prepare a varnish; and a third step of coating one side of the aforementioned substrate in the thickness direction with the aforementioned varnish and drying it to thereby configure a heat-sealing layer.

[0019] Invention Effects

[0020] In the laminate of the present invention, the heat-sealing layer is a dried product of the coating composition. Therefore, it exhibits excellent heat-sealing properties.

[0021] Furthermore, in this laminate, the coating composition comprises a resin component consisting of a copolymer of 4-methyl-1-pentene and an α-olefin (excluding 4-methyl-1-pentene) having 2 to 20 carbon atoms, and / or a modified version of the copolymer. Therefore, air permeability is improved.

[0022] The packaging film of the present invention comprises the laminate of the present invention. Therefore, it has excellent air permeability and heat-sealing properties.

[0023] The method for manufacturing the laminate of the present invention includes the following steps: a second step, dissolving a coating composition in an organic solvent to prepare a varnish; and a third step, applying the varnish to one side of a substrate in the thickness direction and drying it to form a heat-sealing layer. That is, by the second and third steps, a heat-sealing layer, which is a dried product of the coating composition, can be formed on one side of the substrate in the thickness direction. Therefore, according to this method, a laminate with excellent heat-sealing properties can be manufactured.

[0024] Furthermore, in the method for manufacturing this laminate, a coating composition comprising a resin component consisting of a copolymer of 4-methyl-1-pentene and an α-olefin having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene), and / or a modified copolymer thereof. Therefore, according to this method, a laminate with excellent air permeability can be manufactured. Attached Figure Description

[0025] [ Figure 1 ] Figure 1 This is a schematic diagram illustrating one embodiment of the laminate of the present invention.

[0026] [ Figure 2 ] Figure 2 This is a schematic diagram illustrating one embodiment of the method for manufacturing the laminate of the present invention. Figure 2 A shows the first step, namely, preparing the substrate 2. Figure 2 B shows the third step, namely, applying a varnish of the coating composition to one side of the substrate in the thickness direction and drying it, thereby configuring a heat-sealing layer on one side of the substrate in the thickness direction. Detailed Implementation

[0027] <Layered Body>

[0028] Reference Figure 1 An embodiment of the laminate of the present invention will be described in detail below.

[0029] Figure 1In the diagram, the vertical direction on the paper is the vertical direction (thickness direction). Additionally, the upper side of the paper is the upper side (one side of the thickness direction). The lower side of the paper is the lower side (the other side of the thickness direction). Furthermore, the horizontal and depth directions of the paper are plane directions orthogonal to the vertical direction. Specifically, refer to the directional arrows in each diagram.

[0030] The laminate 1 has a film shape (including a sheet shape) with a specified thickness. The laminate 1 extends along a plane direction orthogonal to the thickness direction.

[0031] like Figure 1 As shown, the laminate 1 has a substrate 2 and a heat-sealing layer 3 on the side facing the thickness direction.

[0032] Specifically, the laminate 1 includes a substrate 2 and a heat-sealing layer 3 disposed on the upper surface (one side in the thickness direction) of the substrate 2.

[0033] The thickness of the laminate 1 is, for example, 5 μm or more, and also, for example, 10,000 μm or less.

[0034] <Substrate>

[0035] The substrate 2 extends along the surface direction (orthogonal to the thickness direction) and has a sheet shape having a surface and a back side.

[0036] The substrate 2 is preferably selected in such a way that the air permeability is above a specified value as described later.

[0037] Examples of such substrates 2 include breathable porous substrates and substrates formed from polymers of 4-methyl-1-pentene (preferably homopolymers of 4-methyl-1-pentene).

[0038] Examples of breathable porous substrates include paper, cloth, knitted fabrics, and nonwoven fabrics. Specifically, such porous substrates are composed of, for example, polyolefins, polyesters, natural fibers such as cellulose, fluorinated resins, silicone resins, and urethane resins.

[0039] As the substrate 2, a breathable porous substrate is preferred. If the substrate 2 is a breathable porous substrate, the dried material of the coating composition (described later) can penetrate into the substrate 2, thereby improving the adhesion between the substrate 2 and the heat-sealing layer 3 through the resulting anchoring effect. As a result, the heat-sealing performance is improved.

[0040] The thickness of the substrate 2 is, for example, 1 μm or more, and also, for example, 9999 μm or less.

[0041] <Heat-sealing layer>

[0042] The heat-sealing layer 3 extends along the surface direction (orthogonal to the thickness direction) and has a sheet shape with a flat surface and a back surface. Furthermore, the heat-sealing layer 3 contacts one surface of the substrate 2 in the thickness direction.

[0043] The heat-sealing layer 3 is a dried product of the coating composition. Therefore, it exhibits excellent heat-sealing properties.

[0044] The coating composition contains a resin component.

[0045] [Resin Composition]

[0046] The resin component consists of a copolymer of 4-methyl-1-pentene and an α-olefin having 2 to 20 carbon atoms (excluding 4-methyl-1-pentene) (hereinafter sometimes referred to as a copolymer of 4-methyl-1-pentene and an α-olefin), and / or a modified version of the copolymer of 4-methyl-1-pentene and an α-olefin. In other words, the resin component essentially contains only copolymers of 4-methyl-1-pentene and α-olefins, and / or modified versions of copolymers of 4-methyl-1-pentene and α-olefins. The term "resin component essentially comprising only copolymers of 4-methyl-1-pentene and α-olefins, and / or modified copolymers of 4-methyl-1-pentene and α-olefins" means that, relative to the resin component, the content of the copolymers of 4-methyl-1-pentene and α-olefins, and / or modified copolymers of 4-methyl-1-pentene and α-olefins is, for example, 95% by mass or more, preferably 99% by mass or more, more preferably 99.9% by mass or more, and even more preferably 100% by mass.

[0047] If the resin component is composed of a copolymer of 4-methyl-1-pentene and α-olefin, and / or a modified copolymer of 4-methyl-1-pentene and α-olefin, then air permeability can be improved.

[0048] (A copolymer of 4-methyl-1-pentene and α-olefin)

[0049] The copolymer of 4-methyl-1-pentene and α-olefin is a polymer of 4-methyl-1-pentene and an α-olefin with 2 to 20 carbon atoms.

[0050] Examples of α-olefins with 2 to 20 carbon atoms include linear α-olefins with 2 to 20 carbon atoms and branched α-olefins with 2 to 20 carbon atoms.

[0051] Examples of linear α-olefins with 2 to 20 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

[0052] Examples of branched α-olefins with 2 to 20 carbon atoms include 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, and 3-ethyl-1-hexene.

[0053] As an α-olefin with 2 to 20 carbon atoms, a straight-chain α-olefin with 2 to 20 carbon atoms is preferred. As an α-olefin with 2 to 20 carbon atoms, a straight-chain α-olefin with 2 to 4 carbon atoms is more preferred. As an α-olefin with 2 to 20 carbon atoms, propylene is even more preferred.

[0054] α-olefins with 2 to 20 carbon atoms can be used alone or in combination of two or more.

[0055] Furthermore, copolymers of 4-methyl-1-pentene and α-olefins can be obtained by polymerizing 4-methyl-1-pentene with α-olefins having 2 to 20 carbon atoms using the method described in International Publication No. 2004 / 87775. Specifically, copolymers of 4-methyl-1-pentene and α-olefins can be obtained by polymerizing 4-methyl-1-pentene with α-olefins having 2 to 20 carbon atoms in the presence of a metallocene catalyst.

[0056] Thus, a copolymer of 4-methyl-1-pentene and α-olefin can be obtained (a reaction solution containing the copolymer of 4-methyl-1-pentene and α-olefin).

[0057] In the copolymer of 4-methyl-1-pentene and α-olefin, the proportion of structural units from 4-methyl-1-pentene is 50 mol% or more, preferably 60 mol% or more, and further preferably 99 mol% or less, more preferably 90 mol% or less, relative to the total amount of structural units from 4-methyl-1-pentene and structural units from α-olefin.

[0058] If the proportion of structural units from 4-methyl-1-pentene is above the lower limit mentioned above, the air permeability can be improved.

[0059] On the other hand, if the proportion of structural units from 4-methyl-1-pentene is less than the lower limit mentioned above, the air permeability decreases.

[0060] In addition, if the proportion of structural units from 4-methyl-1-pentene is below the above-mentioned upper limit, the heat-sealing and film-forming properties can be improved.

[0061] On the other hand, if the proportion of structural units from 4-methyl-1-pentene is greater than the above upper limit, the heat-sealing and film-forming properties will decrease.

[0062] Furthermore, relative to the total amount of structural units from 4-methyl-1-pentene and structural units from α-olefins, the structural units from α-olefins are 1 mol% or more, preferably 10 mol% or more, and also 50 mol% or less, preferably 40 mol% or less.

[0063] If the structural unit derived from α-olefin is above the lower limit mentioned above, then the heat-sealing performance and film-forming properties can be improved.

[0064] On the other hand, if the structural units derived from α-olefins are smaller than the aforementioned lower limit, the heat-sealing and film-forming properties decrease.

[0065] In addition, if the structural unit from the α-olefin is below the above upper limit, the air permeability can be improved.

[0066] On the other hand, if the structural units from α-olefins are larger than the above upper limit, the permeability decreases.

[0067] It should be noted that the proportions of structural units from 4-methyl-1-pentene and the proportions of structural units from α-olefins can be determined by, for example... 13 Confirmed using known methods such as C-NMR measurements.

[0068] Furthermore, the weight-average molecular weight of the copolymer of 4-methyl-1-pentene and α-olefin, as determined by GPC (gel permeation chromatography) and converted to standard polystyrene, is, for example, 10,000 or more, preferably 50,000 or more, more preferably 100,000 or more, further preferably 300,000 or more, and, for example, 500,000 or less, preferably 400,000 or less.

[0069] In addition, the weight-average molecular weight / number-average molecular weight (Mw / Mn) of the copolymer of 4-methyl-1-pentene and α-olefin is, for example, 1.5 or more, preferably 2.0 or more, and also, for example, 4.0 or less, preferably 3.0 or less.

[0070] Furthermore, the melting point of the copolymer of 4-methyl-1-pentene and α-olefin is not observable, or, if a melting point is observed, it is, for example, below 199°C, preferably below 150°C, more preferably below 140°C, and, for example, above 80°C, preferably above 100°C.

[0071] If the melting point of the copolymer of 4-methyl-1-pentene and α-olefin is not observable, or is below the upper limit mentioned above, the heat-sealing performance can be further improved.

[0072] It should be noted that the melting point can be determined using a differential scanning calorimeter (DSC) (the same applies below). Furthermore, the phrase "melting point not observed" means that, in DSC-based measurements, no melting peak with a heat of fusion greater than 1 J / g is observed within the temperature range of -150°C to 200°C.

[0073] (Modified copolymer of 4-methyl-1-pentene and α-olefin)

[0074] Modified copolymers of 4-methyl-1-pentene and α-olefins (hereinafter, sometimes referred to as modified copolymers) can be obtained by grafting the copolymers of 4-methyl-1-pentene and α-olefins with grafting components.

[0075] Examples of grafting components include, for example, olefinic unsaturated compounds containing hydroxyl groups, olefinic unsaturated compounds containing amino groups, unsaturated carboxylic acids, unsaturated carboxylic anhydrides, vinyl ester compounds, and olefinic unsaturated compounds containing thiol groups. Unsaturated carboxylic acids and / or unsaturated carboxylic anhydrides are preferred grafting components.

[0076] Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornenedicarboxylic acid, and bicyclo[2,2,1]hept-2-ene-5,6-dicarboxylic acid.

[0077] Examples of unsaturated carboxylic anhydrides include, for example, maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and bicyclic [2,2,1]hept-2-ene-5,6-dicarboxylic anhydride.

[0078] As a grafting component, unsaturated carboxylic anhydrides are more preferred. As a grafting component, maleic anhydride is even more preferred.

[0079] Grafting components can be used alone or in combination of two or more.

[0080] Furthermore, the modified material can be obtained by grafting a copolymer of 4-methyl-1-pentene and α-olefin using grafting components.

[0081] To graft-modify a copolymer of 4-methyl-1-pentene and α-olefin using grafting components, for example, firstly, the copolymer of 4-methyl-1-pentene and α-olefin is dissolved in a known organic solvent (e.g., toluene). Next, the grafting component and a free radical polymerization initiator are added, and they are mixed and heated (specifically, melt-mixed).

[0082] Compared to the modified copolymer of 4-methyl-1-pentene and α-olefin, the amount of grafting component modified (introduced), that is, the proportion of structural units from the grafting component in the modified copolymer of 4-methyl-1-pentene and α-olefin, is, for example, 0.1% by mass or more, preferably 0.5% by mass or more, and for example, 10% by mass or less, preferably 5.0% by mass or less, more preferably 3.0% by mass or less, and even more preferably 2.0% by mass or less.

[0083] The above-mentioned amount of modification can be achieved through, for example... 1 It can be confirmed using known methods such as H-NMR measurement.

[0084] Examples of free radical polymerization initiators include organic peroxides and organic peresters.

[0085] Examples of organic peroxides include, for example, dicumyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(benzoyl peroxide)hex-3-yne, 1,4-bis(tert-butyl peroxide isopropyl)benzene, lauroyl peroxide, 2,5-dimethyl-2,5-di(tert-butyl peroxide)hex-3-yne, 2,5-dimethyl-2,5-di(tert-butyl peroxide)hexane, tert-butyl peroxide, and 2,5-dimethyl-2,5-bis(tert-butyl peroxide)hexane. In addition, examples of organic peresters include tert-butyl peroxyacetate, tert-butyl peroxyphenylacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxyoctanoate, tert-butyl peroxypentanoate, cumyl peroxypentanoate, and tert-butyl peroxydiethylacetate.

[0086] Organic peroxides are preferred as free radical polymerization initiators. 2,5-Dimethyl-2,5-bis(tert-butylperoxide)hexane is more preferred as a free radical polymerization initiator.

[0087] The proportion of the free radical polymerization initiator is, for example, 0.001 parts by mass or more, and, for example, 10 parts by mass or less, relative to 100 parts by mass of the copolymer of 4-methyl-1-pentene and α-olefin.

[0088] Free radical polymerization initiators can be used alone or in combination of two or more.

[0089] The heating temperature is, for example, 50°C or higher, preferably 80°C or higher, and also, for example, 250°C or lower. The reaction time is, for example, 1 minute or more, and also, 10 hours or less.

[0090] Therefore, by grafting the copolymer of 4-methyl-1-pentene and α-olefin with grafting components, a modified copolymer of 4-methyl-1-pentene and α-olefin (varnish of the modified copolymer) is obtained.

[0091] Furthermore, the weight-average molecular weight of the modified material, as determined by GPC (gel permeation chromatography) and converted to standard polystyrene, is, for example, 10,000 or more, preferably 50,000 or more, more preferably 100,000 or more, even more preferably 200,000 or more, and, for example, 500,000 or less, preferably 300,000 or less.

[0092] In addition, the weight-average molecular weight / number-average molecular weight (Mw / Mn) of the modified material is, for example, 1.5 or more, preferably 1.9 or more, and for example, 4.0 or less, preferably 3.0 or less.

[0093] In addition, the melting point of the modified material is not observable, or if a melting point is observed, its melting point is, for example, below 199°C, preferably below 150°C, more preferably below 140°C, and for example, above 80°C, preferably above 100°C.

[0094] If the melting point of the modified material is not observable, or if the melting point is below the upper limit mentioned above, the heat sealing performance can be further improved.

[0095] As described above, the resin component is composed of a copolymer of 4-methyl-1-pentene and α-olefin, and / or a modified version of the copolymer of 4-methyl-1-pentene and α-olefin. Preferably, the resin component is composed of a copolymer of 4-methyl-1-pentene and α-olefin without containing a modified version of the copolymer, or it is composed of a modified version of the copolymer of 4-methyl-1-pentene and α-olefin without containing a modified version of the copolymer.

[0096] Furthermore, since the resin component is composed of a copolymer of 4-methyl-1-pentene and α-olefin, and / or a modified version of the copolymer of 4-methyl-1-pentene and α-olefin, the resin component substantially does not contain other thermoplastic resins. The statement that the resin component substantially does not contain other thermoplastic resins means that, relative to the resin component, the content of other thermoplastic resins is, for example, 5% by mass or less, preferably 1% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0% by mass.

[0097] Other thermoplastic resins include, for example, the thermoplastic resin (B) described in Japanese Patent Application Publication No. 2016-121322. Specifically, other thermoplastic resins include olefin polymers (polymers of α-olefins (excluding 4-methyl-1-pentene)).

[0098] If the resin composition does not substantially contain other thermoplastic resins, it can improve air permeability.

[0099] The resin component is present in a proportion of 80% by mass or more, preferably 90% by mass or more, more preferably 95% by mass or more, and, for example, 100% by mass or less, relative to the coating composition.

[0100] [additive]

[0101] The coating composition may also contain additives in appropriate proportions as needed.

[0102] Examples of additives include, for example, leveling agents, defoamers, antioxidants, heat stabilizers, ultraviolet absorbers, plasticizers, surfactants, pigments, thixotropic agents, thickeners, tackifiers, surface conditioners, antisettling agents, weathering agents, pigment dispersants, antistatic agents, fillers, mildew inhibitors, and silane coupling agents.

[0103] Additives can be used alone or in combination of two or more.

[0104] [Preparation of the coating composition]

[0105] The coating composition can be prepared by mixing the resin components with additives as needed.

[0106] Furthermore, in the second step described later, the coating composition is dissolved in an organic solvent (described later) and prepared as a varnish of the coating composition. The varnish of the coating composition is the organic solvent solution of the coating composition.

[0107] Then, although detailed later, the heat-sealing layer 3 can be formed by applying a varnish of the coating composition to one side of the substrate 2 in the thickness direction and drying it.

[0108] Regarding the thickness of the heat-sealing layer 3, for example, from the viewpoint of molding processability, it is 1 μm or more, preferably 3 μm or more. In addition, for example, from the viewpoint of improving heat sealing performance, it is less than 50 μm, preferably less than 20 μm, and more preferably 19 μm or less.

[0109] <Manufacturing Method of Laminated Materials>

[0110] Reference Figure 2 A and Figure 2 B. One embodiment of the method for manufacturing a laminated body will be described.

[0111] The manufacturing method of the laminate 1 includes the following steps: a first step of preparing a substrate 2; a second step of dissolving a coating composition in an organic solvent to prepare a varnish of the coating composition; and a third step of applying the varnish of the coating composition to one side of the substrate 2 in the thickness direction and drying it, thereby depositing a heat-sealing layer 3 on one side of the substrate 2 in the thickness direction.

[0112] [Step 1]

[0113] In the first process, such as Figure 2 As shown in Figure A, prepare substrate 2.

[0114] [Step 2]

[0115] In the second step, the coating composition is dissolved in an organic solvent to prepare a varnish of the coating composition.

[0116] Examples of organic solvents include, for example, aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, ketones, alkyl esters, glycol ether esters, ethers, and polar aprotic hydrocarbons. Examples of aliphatic hydrocarbons include, for example, n-hexane, n-heptane, and octane. Examples of alicyclic hydrocarbons include, for example, cyclohexane and methylcyclohexane. Examples of aromatic hydrocarbons include, for example, toluene and xylene. Examples of ketones include, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of alkyl esters include, for example, methyl acetate, ethyl acetate, butyl acetate, and isobutyl acetate. Examples of glycol ether esters include, for example, methyl cellolytic acetate, ethyl cellolytic acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, and ethyl 3-ethoxypropionate. Examples of ethers include, for example, diethyl ether, tetrahydrofuran, and dioxane. Examples of polar aprotic ethers include, for example, N-methylpyrrolidone, dimethylformamide, N,N'-dimethylacetamide, dimethyl sulfoxide, and hexamethylphosphoramide.

[0117] Alicyclic hydrocarbons and / or alkyl esters are preferred organic solvents. Methylcyclohexane and / or ethyl acetate are more preferred solvents.

[0118] Organic solvents can be used alone or in combination of two or more. It is preferred to use methylcyclohexane and ethyl acetate as solvents.

[0119] The proportion of organic solvent relative to 100 parts by weight of resin is, for example, 200 parts by weight or more, and, for example, 1000 parts by weight or less.

[0120] The concentration of solid components in the varnish of the coating composition is, for example, 5% by mass or more, and also, for example, 70% by mass or less.

[0121] [Step 3]

[0122] In the third process, such as Figure 2 As shown in B, a varnish of the coating composition is applied to one side of the substrate 2 in the thickness direction and dried, thereby depositing a heat-sealing layer 3 on one side of the substrate 2 in the thickness direction.

[0123] In order to apply the varnish of the coating composition to one side of the substrate 2 in the thickness direction, firstly, the surface of one side of the substrate 2 in the thickness direction is subjected to surface treatment as needed.

[0124] Examples of surface treatments include corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, and saponification treatment, with corona treatment being a preferred option.

[0125] Next, the composition is coated onto one side of the substrate 2 in the thickness direction using a known method, and then dried by heating as needed.

[0126] The heating temperature is, for example, 50°C or higher, preferably 80°C or higher, and also, for example, 250°C or lower. The heating time is, for example, 10 seconds or higher, and also, for example, 600 seconds or lower.

[0127] In addition, especially when the substrate 2 is a nonwoven fabric, after coating the coating composition on one side of the substrate 2 in the thickness direction, from the viewpoint of allowing the coating composition to penetrate into the nonwoven fabric, it is allowed to stand for, for example, 1 hour and, for example, 50 hours or less, and then heated as needed to dry it.

[0128] Thus, a heat-sealing layer 3, serving as the dried product of the varnish coating composition (i.e., the dried product of the coating composition), is disposed (formed) on one side of the substrate 2 in the thickness direction. The laminate 1 is manufactured in this manner.

[0129] Furthermore, as described above, such a laminate 1 includes a heat-sealing layer 3, which is a dried product of the coating composition. Therefore, it exhibits excellent heat-sealing properties.

[0130] Specifically, in the laminate 1, the peel strength, as determined by the following test, is, for example, 2.0 N / 15 mm or more, preferably 4.0 N / 15 mm or more.

[0131] In the experiment, firstly, two laminates 1 were prepared. Then, the two laminates 1 were bonded together with their heat-sealing layers 3 in contact, and heat-sealed at 160°C, 0.3 MPa, and 2 seconds to produce a film. The peel strength of the film was measured by peeling it at a tensile speed of 50 mm / min and a temperature of 23°C along a direction 180° relative to the heat-sealed surface.

[0132] In addition, the oxygen permeability and carbon dioxide permeability of laminate 1 are 1000 cm⁻¹. 3 ·mm / (m 2 (24hr atm) or more.

[0133] More specifically, the oxygen permeability coefficient is 1000 cm⁻¹. 3 ·mm / (m 2 (24hr·atm) or more, preferably 1400cm 3 ·mm / (m 2 • 24hr • atm) or more, and for example, 100,000 cm 3 ·mm / (m 2 (24hr atm) or less.

[0134] In addition, the carbon dioxide permeability is 1000 cm⁻¹ 3 ·mm / (m 2 (24hr·atm) or more, preferably 2000cm 3 ·mm / (m 2 (24hr·atm) or more, preferably 4000cm 3 ·mm / (m 2 • 24hr • atm) or more, and for example, 200,000 cm 3 ·mm / (m 2 (24hr atm) or less.

[0135] It should be noted that the methods for determining the oxygen permeability coefficient and the carbon dioxide permeability coefficient are detailed in the examples described later.

[0136] Furthermore, due to the excellent air permeability and heat-sealing properties of this laminate 1, it is particularly suitable for use in packaging films. Such a packaging film possesses a laminate 1. Therefore, it exhibits excellent air permeability and heat-sealing properties.

[0137] <Effects>

[0138] In this laminate 1, the coating composition comprises a resin component consisting of a copolymer of 4-methyl-1-pentene and α-olefin, and / or a modified copolymer of 4-methyl-1-pentene and α-olefin. Therefore, air permeability is improved.

[0139] In detail, in Patent Document 1, from the viewpoint of improving heat sealing, a polymer other than the polymer containing structural units from 4-methyl-1-pentene (specifically thermoplastic resin (B)) is incorporated into thermoplastic resin (A). However, if thermoplastic resin (B) is incorporated, there is an adverse situation of reduced air permeability.

[0140] On the other hand, in this laminate 1, the resin component is composed of a copolymer of 4-methyl-1-pentene and α-olefin, and / or a modified copolymer of 4-methyl-1-pentene and α-olefin. Therefore, the resin component does not substantially contain other thermoplastic resins (specifically, the thermoplastic resin (B) of Patent Document 1).

[0141] Therefore, it can suppress the decrease in air permeability caused by the combination with thermoplastic resin (B).

[0142] As a result, it improves breathability.

[0143] Furthermore, in the laminate 1, the heat-sealing layer 3 is a dried product of the coating composition. Therefore, the heat-sealing performance is excellent. In particular, in the laminate 1, especially when the substrate 2 is a breathable porous substrate (preferably paper or nonwoven fabric) and its surface has irregularities, the thickness of the heat-sealing layer 3 can be reduced (e.g., less than 50 μm), thereby improving the heat-sealing performance.

[0144] Example

[0145] Next, the present invention will be described based on embodiments and comparative examples, but the present invention is not limited to the embodiments described below. It should be noted that unless otherwise specified, "parts" and "%" are based on mass. In addition, the specific values ​​of the proportions (including proportions), physical property values, parameters, etc. used in the following description can be replaced with the corresponding upper limit values ​​(values ​​defined in the form of "less than" or "less than") or lower limit values ​​(values ​​defined in the form of "more than" or "greater than") of the proportions (including proportions), physical property values, parameters, etc., described in the "Specific Embodiments" above.

[0146] <Ingredient Details>

[0147] The trade names and abbreviations of the ingredients used in each manufacturing example, each embodiment, and each comparative example are described in detail.

[0148] Paper: Trade name "OK Blizzard", manufactured by Oji Materia Co., Ltd.

[0149] Nonwoven fabric: Trade name "Syntex PK102", manufactured by Mitsui Chemicals Co., Ltd.

[0150] TPX: A membrane formed from a polymer of 4-methyl-1-pentene, trade name "Opulent XP-88B", manufactured by Mitsui Chemicals Tohcello, Inc.

[0151] Propylene-ethylene random copolymer: Prime Polypro (registered trademark) F327, propylene-ethylene random copolymer, manufactured by Prime Polymer Co., Ltd.

[0152] <Preparation of a copolymer of 4-methyl-1-pentene and propylene>

[0153] Manufacturing Example 1

[0154] In a 1.5 L SUS autoclave equipped with stirring blades and fully nitrogen-purified, 300 mL of n-hexane (dried on activated alumina under a dry nitrogen atmosphere) and 450 mL of 4-methyl-1-pentene were added at 23 °C. Next, 0.75 mL of a 1.0 mmol / mL toluene solution of triisobutylaluminum (TIBAL) was added to the autoclave and stirred.

[0155] Next, the autoclave is heated to an internal temperature of 60°C and pressurized with propylene at a total pressure (gauge pressure) of 0.40 MPa.

[0156] Next, using nitrogen, 0.34 ml of a pre-prepared toluene solution containing 1 mmol of methylaluminoxane (calculated as Al) and 0.01 mmol of diphenylmethylene (1-ethyl-3-tert-butyl-cyclopentadienyl)(2,7-di-tert-butyl-fluorenyl)zirconium dichloride was pressurized into an autoclave to initiate the polymerization reaction. During the polymerization reaction, the temperature was adjusted to maintain the autoclave's internal temperature at 60°C.

[0157] Sixty minutes after the start of polymerization, 5 ml of methanol was injected into the autoclave using nitrogen to stop the polymerization reaction. The autoclave was then depressurized to atmospheric pressure. After depressurization, acetone was added to the reaction solution while stirring. This yielded a reaction solution containing a copolymer of 4-methyl-1-pentene and propylene.

[0158] Next, the reaction solution containing the copolymer of 4-methyl-1-pentene and propylene was dried at 100°C for 12 hours under reduced pressure. This yielded 36.9 g of the copolymer of 4-methyl-1-pentene and propylene in powder form.

[0159] The copolymer has a weight-average molecular weight of 337,000. Furthermore, the weight-average molecular weight / number-average molecular weight (Mw / Mn) ratio of the copolymer is 2.1. The melting point of the copolymer was not observed. In addition, relative to the total amount of structural units from 4-methyl-1-pentene and structural units from propylene, the content of structural units from 4-methyl-1-pentene is 73 mol%, and the content of structural units from propylene is 27 mol%. It should be noted that the above proportions are obtained through... 13It was obtained by C-NMR measurement.

[0160] Manufacturing Example 2

[0161] By following the same steps as in Manufacturing Example 1, 44.0 g of the 4-methyl-1-pentene-propylene copolymer in powder form was obtained. However, in Manufacturing Example 2, propylene was pressurized to a total pressure (gauge pressure) of 0.19 MPa.

[0162] The copolymer has a weight-average molecular weight of 340,000. Furthermore, the weight-average molecular weight / number-average molecular weight (Mw / Mn) ratio of the copolymer is 2.1. Additionally, the copolymer has a melting point of 132°C. Moreover, in this copolymer, relative to the total amount of structural units from 4-methyl-1-pentene and structural units from propylene, the content of structural units from 4-methyl-1-pentene is 85 mol%, and the content of structural units from propylene is 15 mol%. It should be noted that the above content percentages are obtained through... 13 It was obtained by C-NMR measurement.

[0163] <Preparation of Maleic Anhydride Modified Compound of Copolymer of 4-Methyl-1-pentene and Propylene> Manufacturing Example 3

[0164] The copolymer of 4-methyl-1-pentene and propylene of Manufacturing Example 1 is charged into the resin loading section of a twin-screw compounding extruder equipped with a vent. Further, maleic anhydride as a grafting component is added in 2 parts by mass relative to 100 parts by mass of the copolymer of 4-methyl-1-pentene and propylene, and 2,5-dimethyl-2,5-bis(tert-butylperoxide)hexane as a free radical polymerization initiator in 0.4 parts by mass relative to 100 parts by mass of the copolymer of 4-methyl-1-pentene and propylene.

[0165] Next, the copolymer of 4-methyl-1-pentene and propylene, the grafted component, and the free radical polymerization initiator were melt-blended at 190°C. The blend was then discharged from the blending extruder and cooled. After cooling, it was granulated using a granulator. This yielded a maleic anhydride-modified version of the copolymer of 4-methyl-1-pentene and propylene.

[0166] The weight-average molecular weight of the modified compound is 231,000. Furthermore, the weight-average molecular weight / number-average molecular weight (Mw / Mn) ratio of the modified compound is 2.0. Additionally, the melting point of the modified compound was not observed. Furthermore, the amount of grafted component introduced into the maleic anhydride modified compound of the copolymer of 4-methyl-1-pentene and propylene is 0.9% by mass. It should be noted that the above modification amount is obtained through… 1 It was obtained by H-NMR measurement.

[0167] Manufacturing Example 4

[0168] By following the same steps as in Manufacturing Example 3, a maleic anhydride-modified copolymer of 4-methyl-1-pentene and propylene was obtained. However, in Manufacturing Example 4, the copolymer of 4-methyl-1-pentene and propylene from Manufacturing Example 2 was used instead of the copolymer of 4-methyl-1-pentene and propylene from Manufacturing Example 1.

[0169] The modified compound has a weight-average molecular weight of 208,000. Furthermore, its weight-average molecular weight / number-average molecular weight (Mw / Mn) ratio is 2.1. Additionally, its melting point is 132°C. Furthermore, the amount of grafted component introduced into the maleic anhydride modified compound of the copolymer of 4-methyl-1-pentene and propylene is 1.8% by mass. It should be noted that the above modification amount is obtained through… 1 It was obtained by H-NMR measurement.

[0170] <Preparation of maleic anhydride-modified propylene / 1-butene copolymer>

[0171] Manufacturing Example 5

[0172] In a 2L autoclave that has undergone thorough nitrogen purging, 900ml of hexane and 90g of 1-butene were added, followed by 1 mmol of triisobutylaluminum, and the mixture was heated to 70°C. Propylene was then supplied to bring the total pressure to 7 kg / cm². 2 G, add 0.30 mmol of methylaluminoxane and 0.001 mmol of racemic-dimethylmethylenesilyl-bis{1-(2-methyl-4-phenylindenyl)}zirconium dichloride, while continuously supplying propylene and maintaining the total pressure at 7 kg / cm². 2 G. A polymerization reaction was carried out for 30 minutes. After polymerization, degassing was performed, the polymer was recovered in a large amount of methanol, and then dried under reduced pressure at 110°C for 12 hours. This yielded a propylene / 1-butene copolymer.

[0173] The propylene / 1-butene copolymer has a weight-average molecular weight of 300,000. Its melting point is 78.3°C. Furthermore, in this copolymer, the proportion of structural units from propylene is 75 mol%, and the proportion of structural units from 1-butene is 25 mol%, relative to the total amount of structural units from propylene and 1-butene. It should be noted that the above proportions are obtained through... 13 It was obtained by C-NMR measurement.

[0174] Next, 3 kg of propylene / 1-butene copolymer was added to 10 L of toluene, and the mixture was heated to 145 °C under a nitrogen atmosphere to dissolve the propylene / 1-butene copolymer in the toluene. Further, 382 g of maleic anhydride and 175 g of di-tert-butyl peroxide (as a free radical polymerization initiator) were added under stirring for 4 hours, and the mixture was stirred at 145 °C for 2 hours. This yielded maleic anhydride-modified propylene / 1-butene copolymer. The copolymer was then cooled, and a large amount of acetone was added to precipitate it. After filtration, washing with acetone, and vacuum drying, the copolymer was then obtained.

[0175] The weight-average molecular weight (Mw) of the maleic anhydride-modified propylene / 1-butene copolymer is 100,000. The melting point of the maleic anhydride-modified propylene / 1-butene copolymer is 75.8°C. Furthermore, the amount of maleic anhydride modification in the maleic anhydride-modified propylene / 1-butene copolymer is 0.8% by mass. It should be noted that the above modification amount is obtained through... 1 It was obtained by H-NMR measurement.

[0176] <Preparation of Homopolymers of 4-Methyl-1-pentene>

[0177] Manufacturing Example 6

[0178] By following the same steps as in Manufacturing Example 1, 36.9 g of powdered 4-methyl-1-pentene homopolymer was obtained. However, in Manufacturing Example 6, propylene was not used for pressurization.

[0179] The polymer has a weight-average molecular weight of 337,000. Furthermore, its weight-average molecular weight / number-average molecular weight (Mw / Mn) ratio is 2.1. Additionally, the copolymer has a melting point of 222°C.

[0180] <Fabrication of Layered Structures>

[0181] Example 1

[0182] [Step 1]

[0183] Prepare paper as the base material.

[0184] [Step 2]

[0185] To a nitrogen-purified flask (5 L capacity), 650 parts by mass of the copolymer from Manufacturing Example 1, 1040 parts by mass of ethyl acetate, and 1560 parts by mass of methylcyclohexane were added. The mixture was heated to 70°C and dissolved for 3 hours. Then, it was cooled to below 60°C. This yielded a varnish containing the coating composition. The solid content concentration of the varnish was 20% by mass.

[0186] [Step 3]

[0187] A varnish containing the above-described coating composition is applied to one side of a substrate in the thickness direction and dried at 100°C for 1 minute. This creates a heat-sealing layer (19 μm thick after drying) on ​​one side of the substrate in the thickness direction. A laminate is thus manufactured.

[0188] Examples 2 to 6, Comparative Examples 1, 2 and 4

[0189] The laminate was manufactured using the same steps as in Example 1. However, the type of substrate and the composition of the varnish of the coating composition were changed according to Table 1. In addition, in Example 5 and Comparative Example 2, the varnish of the coating composition was applied to one side of the substrate in the thickness direction, left to stand at room temperature for 5 hours, and then dried at 100°C for 1 minute.

[0190] Comparative Example 3

[0191] 60 parts by weight of the copolymer from Manufacturing Example 1 and 40 parts by weight of the propylene-ethylene random copolymer were mixed (dry mixing) to obtain a mixture. Next, the mixture was fed into the feed hopper of a 20mm φ single-screw extruder (single-screw sheet forming machine, manufactured by Tanaka Tekko Co., Ltd.) equipped with a T-die with a die lip width of 240mm. Then, the barrel temperature and die temperature were set to 230°C, and the molten compound was extruded from the T-die to a thickness of 50μm, thereby casting and forming a laminate on one side of the paper in the thickness direction. This produced a laminate.

[0192] <Evaluation>

[0193] [Breathability]

[0194] The oxygen permeability coefficient (unit: cm) was measured for the laminates of each embodiment and each comparative example. 3 ·mm / (m 2 ·24h·atm) and carbon dioxide transmission coefficient (unit: cm) 3 ·mm / (m 2 ·24h·atm)).

[0195] Specifically, firstly, the laminates of each embodiment and each comparative example are shaped into a form with a width of 30mm and a length of 30mm.

[0196] Next, following JIS K7126-1, a gas permeability measuring apparatus (manufactured by Toyo Seiki Co., Ltd.) was used to measure the gas permeability of the laminate under test conditions of 23°C and 0% RH, with the measured area being 7 cm². 2Measurements were performed. For the measurement area of ​​the laminate, two aluminum masks with adhesive, manufactured by ModernCotrol and containing a 25mm diameter hole in the center, were prepared and laminated to hold the sample. Specifically, the film was arranged so that the central hole overlapped in both masks. The results are shown in Table 1.

[0197] [Heat-sealing performance]

[0198] The laminates of each embodiment and comparative example were cut into strips with a width of 150 mm and a length of 50 mm to prepare two laminates. The two laminates were bonded together with their heat-sealed layers in contact, and heat-sealed using a heat-sealing testing machine (TP-701-B thermal gradient heat-sealing tester, manufactured by Tester Industry Co., Ltd.) at a sealing width of 5 mm, 160°C, a sealing pressure of 0.3 MPa, and a time of 2 seconds to produce a film. For the film, the peel strength (unit: N / 15 mm) was measured using an Intesco precision testing machine (210N type, manufactured by INTESCO Corporation) at a tensile speed of 50 mm / min and a temperature of 23°C, peeled along a direction at 180° relative to the heat-sealed surface. The test was performed 5 times, and the average values ​​are shown in Table 1.

[0199] [Table 1]

[0200]

[0201] It should be noted that the above-described invention is provided as an illustrative embodiment of the present invention, but it is merely illustrative and not intended to be limiting. Modifications of the present invention that will be apparent to those skilled in the art are included in the appended claims.

[0202] Industrial availability

[0203] The laminate, packaging film, and method for manufacturing the laminate of the present invention can be suitably used, for example, in packaging materials.

Claims

1. A laminate, which is a laminate having a substrate and a heat-sealing layer sequentially on one side facing the thickness direction. The heat-sealing layer is a dried product of the coating composition. The coating composition comprises a resin component. The resin component is composed of a copolymer of 4-methyl-1-pentene and an α-olefin having 2 to 20 carbon atoms, and / or a modified version of the copolymer, wherein, The α-olefin is not 4-methyl-1-pentene. In the copolymer, relative to the total amount of structural units from the 4-methyl-1-pentene and structural units from the α-olefin, the content of structural units from the 4-methyl-1-pentene is 50 mol% to 99 mol%, and the content of structural units from the α-olefin is 1 mol% to 50 mol%. The oxygen permeability and carbon dioxide permeability of the laminate are both 1000 cm⁻¹. 3 ·mm / (m 2 (24hr atm) or more, The resin component is present in a proportion of 80% by mass or more relative to the coating composition. The substrate is a breathable porous substrate or a substrate formed from a polymer of 4-methyl-1-pentene. The peel strength, as determined by the following test, is greater than 2.0 N / 15 mm. The oxygen permeability and carbon dioxide permeability were determined based on JIS K7126-1. Experiment: Prepare two laminates; bond the two laminates together with their heat-sealed layers in contact with each other, and heat seal them at 160°C, 0.3MPa and 2 seconds to produce a film; for the film, peel it at a stretching speed of 50mm / min and a temperature of 23°C along a direction of 180° relative to the heat-sealed surface and measure the peel strength.

2. The laminated body as claimed in claim 1, wherein, The thickness of the heat-sealing layer is greater than 1 μm and less than 50 μm.

3. A packaging film comprising the laminate as described in claim 1.

4. The method for manufacturing a laminate according to claim 1, wherein the method for manufacturing a laminate comprises the following steps: Step 1: Prepare the substrate; In the second step, the coating composition is dissolved in an organic solvent to prepare a varnish; and In the third step, the varnish is applied to one side of the substrate in the thickness direction and dried to form a heat-sealing layer.

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