Copolymer, laminate, and method for producing laminate

Abstract

This laminate is a copolymer for bonding molded bodies that contain a fluororesin, the copolymer containing a monomer unit that is derived from an olefin monomer having 2 to 8 carbon atoms and a monomer unit that has a glycidyl group. The proportion of the monomer unit that has a glycidyl group in the copolymer is 10 mass% or more based on the total mass of the copolymer. The present invention is provided with a resin layer that contains a fluororesin, and an adhesive layer that is formed on the surface of a molded body, and the adhesive layer contains the above-described copolymer.

Description

Copolymer, laminate, and method for producing laminate

[0001] The present invention relates to a copolymer, a laminate, and a method for producing the laminate.

[0002] Fluorine resins have excellent properties such as heat resistance, flame retardancy, chemical resistance, weather resistance, non-stickiness, low friction, low dielectric properties, etc. Therefore, molded articles containing fluororesin are used in a wide range of fields such as corrosion-resistant piping materials in chemical plants, agricultural greenhouse materials, release coating materials for kitchen utensils, coating materials for electronic devices, and coating materials for heat-resistant and flame-retardant electric wires.

[0003] However, since molded articles containing fluororesin have low surface energy and low affinity with other materials, the adhesiveness to the molded article may be insufficient. Therefore, studies have been made to improve the adhesiveness between the molded article containing fluororesin and other members. For example, Patent Document 1 studies a method for improving the adhesive strength to the fluororesin by reacting a thermal adhesive resin having a functional group with the functional group of the fluororesin.

[0004] JP 2012-84587 A

[0005] However, the higher the melting point of a molded product containing a fluororesin, the greater the proportion of the fluororesin in the molded product tends to be, and since the adhesiveness to the fluororesin tends to be low, the higher the melting point of the molded product, the lower the adhesiveness to the molded product. Therefore, there is a demand for further improvement in the adhesiveness to molded products with high melting points.

[0006] An object of one aspect of the present invention is to provide a copolymer having excellent adhesion to a molded article containing a fluororesin. Another object of the present invention is to provide a laminate obtained using the copolymer and a method for producing the same.

[0007] The present invention includes, for example, the following: [1] A copolymer for bonding molded articles containing a fluororesin, the copolymer comprising a monomer unit derived from an olefin monomer having 2 to 8 carbon atoms and a monomer unit having a glycidyl group, wherein the proportion of the monomer unit having a glycidyl group in the copolymer is 10% by mass or more, based on the total mass of the copolymer. [2] The copolymer according to [1], wherein the monomer unit derived from an olefin monomer having 2 to 8 carbon atoms is a monomer unit derived from ethylene. [3] The copolymer according to [1] or [2], wherein the monomer unit having a glycidyl group is a monomer unit derived from glycidyl (meth)acrylate. [4] The copolymer according to any one of [1] to [3], wherein the proportion of the monomer unit having a glycidyl group in the copolymer is 13% by mass or more, based on the total mass of the copolymer. [5] The copolymer according to any one of [1] to [4], wherein the proportion of the monomer unit having a glycidyl group in the copolymer is 20% by mass or less, based on the total mass of the copolymer. [6] The copolymer according to any one of [1] to [5], wherein the fluororesin is a copolymer containing a monomer unit derived from ethylene and a monomer unit derived from tetrafluoroethylene. [7] The copolymer according to any one of [1] to [6], wherein the melting point of the molded article is 200°C or higher and 260°C or lower. [8] The copolymer according to any one of [1] to [7], wherein the molded article is a molded article that has not been surface-modified. [9] A laminate comprising a resin layer containing the fluororesin and an adhesive layer formed on the surface of the molded article, wherein the adhesive layer comprises the copolymer according to any one of [1] to [8].

[10] The laminate according to [9], which is a film, a multilayer sheet, or a multilayer tube.

[11] A method for producing a laminate comprising a resin layer containing a fluororesin, and an adhesive layer containing a copolymer and formed on a surface of the resin layer, the method comprising: forming the adhesive layer on the surface of the resin layer by heat sealing; or forming the adhesive layer on the surface of the resin layer by co-extruding a resin containing at least the fluororesin and a resin containing at least the copolymer; wherein the copolymer contains a monomer unit derived from an olefin monomer having 2 to 8 carbon atoms and a monomer unit having a glycidyl group, and the proportion of the monomer unit having a glycidyl group in the copolymer is 10 mass% or more based on the total mass of the copolymer.

[0008] According to the present invention, it is possible to provide a copolymer having excellent adhesive strength to a molded article containing a fluororesin, and also to provide a laminate obtained using the copolymer and a method for producing the same.

[0009] FIG. 1 is a schematic cross-sectional view of a laminate according to one embodiment.

[0010] Several examples of the present invention will be described in detail below, but the present invention is not limited to the following examples.

[0011] A copolymer according to one embodiment of the present invention is used for bonding molded articles containing fluororesin. The copolymer contains monomer units derived from an olefin monomer having 2 to 8 carbon atoms and monomer units having a glycidyl group, and the proportion of the monomer units having a glycidyl group in the copolymer is 10 mass% or more based on the total mass of the copolymer. Such a copolymer has excellent adhesive strength to molded articles containing fluororesin. In particular, even when the melting point of the molded article containing fluororesin is high (e.g., 200°C or higher), the copolymer has excellent adhesive strength to molded articles containing fluororesin.

[0012] <Copolymer> The copolymer contains monomer units derived from an olefin monomer having 2 to 8 carbon atoms and monomer units having a glycidyl group, and the proportion of the monomer units having a glycidyl group in the copolymer is 10 mass% or more based on the total mass of the copolymer (the total mass of the monomer units constituting the copolymer). Hereinafter, such a copolymer will also be referred to as "copolymer A."

[0013] The monomer unit derived from an olefin monomer having 2 to 8 carbon atoms may be a monomer unit derived from ethylene, a monomer unit derived from an α-olefin, or a combination thereof, or may be a monomer unit derived from ethylene. Examples of the α-olefin include linear olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene; cyclic olefins such as norbornene, 5-methylnorbornene, and 1-methylnorbornene; and aromatic olefins such as styrene.

[0014] The proportion of monomer units derived from olefin monomers having 2 to 8 carbon atoms in copolymer A may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 81% by mass or more, 82% by mass or more, or 83% by mass or more, based on the total mass of copolymer A, from the viewpoint that copolymer A has superior adhesive strength to molded articles containing fluororesin. The proportion of monomer units derived from olefin monomers having 2 to 8 carbon atoms in copolymer A may be 90% by mass or less, 88% by mass or less, 86% by mass or less, or 84% by mass or less, based on the total mass of copolymer A, from the viewpoint that copolymer A has superior adhesive strength to molded articles containing fluororesin. The proportion of monomer units derived from ethylene may be within the same range as the proportion of monomer units derived from olefin monomers having 2 to 8 carbon atoms.

[0015] The monomer unit having a glycidyl group may be a monomer unit derived from an unsaturated carboxylic acid glycidyl ester, a monomer unit derived from a glycidyl ether having an unsaturated group, or a combination thereof. From the viewpoint of providing Copolymer A with superior adhesive strength to a molded article containing a fluororesin, the monomer unit having a glycidyl group may be a monomer unit derived from an unsaturated carboxylic acid glycidyl ester.

[0016] The unsaturated carboxylic acid glycidyl ester from which the glycidyl group-containing monomer unit is derived may be a compound represented by the following formula (1), from the viewpoint that copolymer A has superior adhesive strength to a molded article containing a fluororesin. １ represents an alkenyl group having 2 to 18 carbon atoms, and the alkenyl group may have one or more substituents. Examples of the compound represented by formula (1) include glycidyl acrylate, glycidyl methacrylate, and glycidyl itaconic acid ester. The compound represented by formula (1) may be glycidyl methacrylate, from the viewpoint that copolymer A has superior adhesive strength to molded articles containing fluororesin.

[0017]

[0018] The glycidyl ether having an unsaturated group from which a monomer unit having a glycidyl group is derived may be a compound represented by the following formula (2), from the viewpoint that copolymer A has superior adhesive strength to a molded article containing a fluororesin. ２ represents an alkenyl group having 2 to 18 carbon atoms, and the alkenyl group may have one or more substituents. X represents CH ２ -O(CH ２ is R ２ (bonded to) or an oxygen atom. Examples of the compound represented by formula (2) include allyl glycidyl ether, 2-methylallyl glycidyl ether, and styrene-p-glycidyl ether.

[0019]

[0020] The proportion of the monomer units having a glycidyl group in copolymer A is 10% by mass or more, based on the total mass of copolymer A. From the viewpoint of copolymer A having better adhesive strength to molded articles containing fluororesin, the proportion of the monomer units having a glycidyl group in copolymer A may be 12% by mass or more, 13% by mass or more, 14% by mass or more, 15% by mass or more, 16% by mass or more, or 18% by mass or more, based on the total mass of copolymer A. From the viewpoint of excellent storage stability of the copolymer and of copolymer A having better adhesive strength to molded articles containing fluororesin, the proportion of the monomer units having a glycidyl group in copolymer A may be 30% by mass or less, 26% by mass or less, 24% by mass or less, 20% by mass or less, 19% by mass or less, 18% by mass or less, or 17% by mass or less, based on the total mass of copolymer A.

[0021] The mass ratio of monomer units having a glycidyl group to monomer units derived from an olefin monomer having 2 to 8 carbon atoms (ratio of monomer units having a glycidyl group / ratio of monomer units derived from an olefin monomer having 2 to 8 carbon atoms) may be 0.1 or more, 0.13 or more, 0.15 or more, 0.17 or more, 0.18 or more, 0.19 or more, or 0.2 or more, from the viewpoint of copolymer A having superior adhesive strength to a molded article containing a fluororesin, and may be 0.6 or less, 0.5 or less, 0.4 or less, 0.3 or less, 0.25 or less, 0.24 or less, 0.23 or less, 0.22 or less, or 0.21 or less, from the same viewpoint.

[0022] Copolymer A may contain monomer units other than monomer units derived from olefin monomers having 2 to 8 carbon atoms and monomer units having a glycidyl group (hereinafter also referred to as "other monomer units"). Examples of other monomer units include monomer units derived from (meth)acrylic acid esters and monomer units derived from vinyl ethers. In this specification, "(meth)acrylate" means acrylate or methacrylate, and this also applies to similar compounds.

[0023] Examples of the (meth)acrylic acid ester from which the (meth)acrylic acid ester-derived monomer unit is derived include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate.

[0024] Examples of vinyl ethers from which vinyl ether-derived monomer units are derived include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, and phenyl vinyl ether.

[0025] From the viewpoint of providing copolymer A with superior adhesive strength to a molded article containing a fluororesin, the proportion of the other monomer units in copolymer A may be 3% by mass or less, 1% by mass or less, 0.5% by mass or less, or 0.1% by mass or less, based on the total mass of copolymer A. The proportion of the other monomer units in copolymer A may be 0% by mass, based on the total mass of copolymer A.

[0026] Examples of copolymer A include ethylene-glycidyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-methyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-ethyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-normal propyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-isopropyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-normal butyl (meth)acrylate copolymer, ethylene-glycidyl (meth)acrylate-isobutyl (meth)acrylate copolymer, and ethylene-glycidyl (meth)acrylate-vinyl ether copolymer. Copolymer A may be an ethylene-glycidyl (meth)acrylate copolymer, from the viewpoint that copolymer A has superior adhesive strength to molded articles containing fluororesin.

[0027] From the viewpoint of copolymer A having superior adhesive strength to a molded article containing a fluororesin, the melt flow rate (MFR) of copolymer A may be 0.1 g / 10 min or more, 0.5 g / 10 min or more, 1 g / 10 min or more, 3 g / min or more, 5 g / 10 min or more, or 7 g / 10 min or more. The MFR of copolymer A may be 100 g / 10 min or less, 50 g / 10 min or less, 30 g / 10 min or less, or 10 g / 10 min or less. The MFR of copolymer A can be measured in accordance with JIS K7210 under conditions of a temperature of 190°C and a load of 2.16 kgf.

[0028] The adhesive strength of the copolymer to a molded article containing a fluororesin may vary depending on the melting point of the molded article containing a fluororesin. For example, when the melting point of the molded article containing a fluororesin is 255°C, the adhesive strength of copolymer A to a molded article containing a fluororesin may be 3 N / 10 mm or more. If the adhesive strength is 3 N / 10 mm or more, it can be said that the copolymer has excellent adhesiveness to a molded article containing a fluororesin. The adhesive strength of the copolymer to a molded article containing a fluororesin can be measured by the method described in the Examples below.

[0029] When the melting point of the fluororesin-containing molded article is 255°C, the adhesive strength of copolymer A to the fluororesin-containing molded article may be 5 N / 10 mm or more, 7 N / 10 mm or more, 8 N / 10 mm or more, 10 N / 10 mm or more, 12 N / 10 mm or more, 14 N / 10 mm or more, 15 N / 10 mm or more, 18 N / 10 mm or more, 20 N / 10 mm or more, 30 N / 10 mm or more, 40 N / 10 mm or more, or 45 N / 10 mm or more, from the viewpoint of copolymer A having superior adhesive strength to the fluororesin-containing molded article.

[0030] Copolymer A can be synthesized by various methods. For example, copolymer A can be produced by bulk polymerization using a free radical initiator, emulsion polymerization, solution polymerization, etc. A typical example of a polymerization method for synthesizing copolymer A is a polymerization method in which copolymer A is polymerized under a polymerization pressure of 500 kg / cm in the presence of a polymerization initiator that generates free radicals. ２This is a method for copolymerizing an olefin monomer having 2 to 8 carbon atoms, a monomer having a glycidyl group, and, if necessary, a (meth)acrylic acid ester or a vinyl ether, under the conditions of a polymerization temperature of 40 to 300°C. The polymerization pressure is 1000 kg / cm. ２ or more, 2000 kg / cm ２ The polymerization temperature may be 100 to 250° C., or 150 to 200° C. Since the olefin monomer having 2 to 8 carbon atoms, the monomer having a glycidyl group, and, if necessary, the (meth)acrylic acid ester or vinyl ether are randomly copolymerized, the olefin monomer having 2 to 8 carbon atoms and the monomer having a glycidyl group are at least present in the main chain.

[0031] Copolymer A is used for bonding molded articles containing fluororesin, that is, copolymer A can also be said to be an adhesive for molded articles containing fluororesin.

[0032] From the viewpoint of excellent mechanical strength, the fluororesin may be a copolymer containing a monomer unit derived from ethylene and a monomer unit derived from tetrafluoroethylene (ethylene-tetrafluoroethylene (ETFE)). That is, the copolymer A may be for use in adhering molded articles containing ETFE.

[0033] The molded article may consist solely of a fluororesin, or may further contain components other than the fluororesin, such as additives such as antioxidants, heat stabilizers, ultraviolet absorbers, color inhibitors, plasticizers, flame retardants, mold release agents, antistatic agents, and colorants.

[0034] From the viewpoint of excellent mechanical strength, the content of the fluororesin in the molded product may be 80 mass% or more, 90 mass% or more, 95 mass% or more, or 100 mass% (i.e., the molded product is substantially composed of the fluororesin) based on the total mass of the molded product. The content of ETFE in the molded product may be within the above range.

[0035] The melting point of the molded article may be 200°C or higher, 210°C or higher, 220°C or higher, 230°C or higher, 240°C or higher, or 250°C or higher. Copolymer A has excellent adhesive strength to the molded article even if the molded article has a high melting point (for example, 200°C or higher). The melting point of the molded article may be 300°C or lower, 280°C or lower, or 260°C or lower, from the viewpoint that copolymer A has better adhesive strength to a molded article containing a fluororesin. The melting point of the molded article can be measured, for example, by a thermal analysis device, differential scanning calorimeter (DSC), in accordance with ASTM D3159. When the molded article is made of a fluororesin, the melting point of the molded article can be considered to be the same as the melting point of the fluororesin.

[0036] The molded article may be a molded article that has been surface-modified (for example, plasma surface treatment), or may be a molded article that has not been surface-modified. By surface-modifying the molded article, the adhesive strength to the molded article can be further improved, but since copolymer A has excellent adhesive strength to the molded article, it also has sufficient adhesive strength to the molded article that has not been surface-modified. The surface roughness Rz of the molded article may be, for example, 4.5 μm or less. The fact that the molded article has been surface-modified can be expressed by the following formula: ６０ This can be confirmed by XPS depth profile analysis using ion sputtering. For example, when the molded body is subjected to plasma surface treatment, the surface is subjected to an XPS analysis using Ar and C. ６０ An ion gun was installed, and AlKα characteristic X-rays were used as the X-ray source. The irradiation conditions of the Ar ion beam were 2 kV, the incident angle was 39 degrees from the normal to the sample surface, and C ６０ The ion beam irradiation conditions were 10 kV, the ion incident angle was 67 degrees from the vertical of the sample surface, and the XPS measurement was performed at a detection angle of 75 degrees. ６０ This can be confirmed by the change in the C1s narrow spectrum due to sputtering.

[0037] <Laminate> The above-described copolymer A can be adhered to a molded article containing a fluororesin to form a laminate 10 having a resin layer 1 containing a fluororesin and an adhesive layer 2 containing copolymer A, as shown in Figure 1. That is, another embodiment of the present invention is a laminate comprising a resin layer containing a fluororesin and an adhesive layer formed on the surface of the molded article, the adhesive layer containing a copolymer, the copolymer containing monomer units derived from an olefin monomer having 2 to 8 carbon atoms and monomer units having a glycidyl group, and the proportion of the monomer units having a glycidyl group in the copolymer being 10 mass% or more based on the total mass of the copolymer.

[0038] From the viewpoint of excellent mechanical strength, the content of the fluororesin in the resin layer may be 80 mass% or more, 90 mass% or more, 95 mass% or more, or 100 mass% (i.e., the resin layer is substantially composed of the fluororesin) based on the total mass of the resin layer. The content of ETFE in the resin layer may be within the above range.

[0039] The content of copolymer A in the adhesive layer may be 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass (i.e., an embodiment in which the adhesive layer is essentially composed of copolymer A) based on the total mass of the adhesive layer, from the viewpoint that the adhesive layer has excellent adhesive strength to the molded body.

[0040] The adhesive layer may further contain a component other than copolymer A. Examples of the component other than copolymer A include resins other than copolymer A, fillers, conductive materials, compatibilizers, antioxidants, heat stabilizers, UV absorbers, coloring inhibitors, plasticizers, flame retardants, plasticizers, release agents, antistatic agents, and colorants. The adhesive layer may contain any of the above-mentioned components other than copolymer A, or may contain none of them, or may contain none of them (i.e., an embodiment in which the adhesive layer is essentially composed of copolymer A).

[0041] The laminate may have layers other than the resin layer and the adhesive layer. For example, the laminate may have a release layer, a surface protective layer, a gas barrier layer, or the like on the surface of the adhesive layer opposite to the resin layer, or the resin layers and the adhesive layers may be laminated alternately.

[0042] The laminate may be a film having at least a resin layer and an adhesive layer, or may be a multilayer sheet. Furthermore, since the adhesive layer has excellent adhesive strength to the resin layer containing a fluororesin, the resin layer and the adhesive layer can maintain a tight contact state even when the laminate is curved. Therefore, the laminate is not limited to a two-dimensional shape such as a film, but may be a tubular shape (multilayer tube) or may have a shape that conforms to the shape of a component or the like. The term "film" refers to a laminate having a thickness of less than 250 μm, and the term "sheet" refers to a laminate having a thickness of 250 μm or more.

[0043] The thickness of the resin layer in the laminate may be, for example, 5 to 5000 μm, 5 to 4000 μm, or 5 to 3000 μm.

[0044] The thickness of the adhesive layer in the laminate may be, for example, 1 to 3000 μm, 1 to 2000 μm, or 1 to 1000 μm.

[0045] <Method for Producing Laminate> The above-described laminate can be produced, for example, by forming an adhesive layer on the surface of a resin layer by heat sealing. Alternatively, the above-described laminate can also be produced by co-extruding a resin containing a fluororesin or the like that constitutes the resin layer and a resin containing copolymer A or the like that constitutes the adhesive layer to form an adhesive layer on the surface of the resin layer. That is, another embodiment of the present invention is a method for producing a laminate comprising a resin layer containing a fluororesin and an adhesive layer that contains a copolymer and is formed on the surface of the resin layer, the method comprising: a step of forming an adhesive layer on the surface of the resin layer by heat sealing; or a step of co-extruding a resin containing at least a fluororesin and a resin containing at least a copolymer to form an adhesive layer on the surface of the resin layer; the copolymer comprises a monomer unit derived from an olefin monomer having 2 to 8 carbon atoms and a monomer unit having a glycidyl group, and the proportion of the monomer unit having a glycidyl group in the copolymer is 10% by mass or more based on the total mass of the copolymer.

[0046] The laminate may be produced by heat sealing, which allows the layers to be bonded for any time and at any pressure, and allows the conditions to be easily changed depending on the type of resin, the thickness of each layer, etc. When producing the laminate by heat sealing, the laminate can be produced, for example, by producing a molded product containing a fluororesin and a molded product containing copolymer A, then overlapping these molded products and heat sealing them using a heat sealer. The heat sealing conditions may be, for example, a heat sealing temperature of 150 to 400°C, a sealing surface pressure of 0.1 to 1 MPa, and a sealing time of 1 to 30 seconds.

[0047] The laminate can be formed into various shapes (for example, a film or a pipe), and may be produced by coextrusion, from the viewpoint of reducing the number of steps and costs involved in producing the laminate by omitting the bonding step. When producing the laminate by coextrusion, the laminate can be produced, for example, by melt-kneading a resin containing at least a fluororesin and a resin containing at least a copolymer in an extruder, and then introducing the mixture into a T-die and extruding.

[0048] The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the following examples. 1. Raw Materials The following raw materials were prepared. Copolymer A, fluororesin, and LLDPE were each prepared as resin pellets. (A) Copolymer A EGMA-1 (a random copolymer of 81 mass% ethylene and 19 mass% glycidyl methacrylate (GMA), MFR = 7 g / 10 min) EGMA-2 (a random copolymer of 88 mass% ethylene and 12 mass% glycidyl methacrylate (GMA), MFR = 3 g / 10 min) EGMA-3 (a random copolymer of 94 mass% ethylene and 6 mass% glycidyl methacrylate (GMA), MFR = 3 g / 10 min) EGMA-4 (a random copolymer of 85 mass% ethylene and 15 mass% glycidyl methacrylate (GMA), MFR = 5 g / 10 min) EGMA-5 (a random copolymer of 85.4 mass% ethylene and 15.6 mass% glycidyl methacrylate (GMA), MFR = 5 g / 10 min) EGMA-6 (a random copolymer of 83.1% by mass of ethylene and 16.9% by mass of glycidyl methacrylate (GMA), MFR = 6 g / 10 min) (B) Fluororesin ETFE-1 (a copolymer of ethylene and tetrafluoroethylene, Neoflon EP-7000, manufactured by Daikin Corporation, melting point 255°C) ETFE-2 (a copolymer of ethylene and tetrafluoroethylene, Fluon ADHESIVE AH-5000, manufactured by AGC Inc., melting point 225°C) (C) LLDPE LLDPE (a random copolymer of ethylene and 1-hexene, MFR = 2 g / 10 min)

[0049] (Examples 1 to 4, 6 to 8, Comparative Examples 1 and 2) 2. Preparation of Laminates by Heat Sealing Method 2-1. Preparation of Fluororesin Molded Body Resin pellets of the fluororesins shown in Tables 1 and 3 were heated at 260°C for 10 minutes using a vacuum press (IMC-19E6, manufactured by Imoto Manufacturing Co., Ltd.) and then cooled at 30°C for 5 minutes to prepare a 1.0 mm thick sheet-like fluororesin molded body. The prepared sheet-like fluororesin molded body was not surface-modified. 2-2. Preparation of Ethylene-Based Copolymer Molded Body Resin pellets of copolymer A shown in Tables 1 and 3 were heated at 190°C for 10 minutes using a vacuum press (IMC-19E6, manufactured by Imoto Manufacturing Co., Ltd.) and then cooled at 30°C for 5 minutes to prepare a 0.1 mm thick sheet-like ethylene-based copolymer molded body. 2-3. Preparation of Laminate: The prepared fluororesin molded article, the prepared ethylene copolymer molded article, and a 0.1 mm thick aluminum plate were stacked in this order, and heat-sealed using a heat sealer (manufactured by Tester Sangyo) with the temperature of the seal bar on the aluminum plate side (heat sealing temperature) at 300°C, the temperature of the silicone sheet on the fluororesin molded article side at 60°C, the sealing surface pressure at 0.3 MPa, the sealing time at 3 seconds, and the sealing width at 10 mm to prepare a laminate. 2-4. Evaluation of Adhesive Strength: A 10 mm wide test piece was cut out perpendicular to the heat-sealed surface of the prepared laminate, and a 180° peel strength test was performed at a speed of 100 mm / min using a 5564 type tensile tester (manufactured by Instron). The average value of the peel strength within the range in which the peel strength stabilized was taken as the adhesive strength.

[0050] (Example 5, Comparative Example 3) 3-1. Preparation of Laminates by Coextrusion Method Three-type, three-layer laminates were prepared using the fluororesins shown in Table 2 for outer layer 1, the copolymers shown in Table 2 for intermediate layers, and LLDPE for outer layer 2 in contact with the chill roll. The films were prepared by coextrusion using three 30 mmφ extruders (manufactured by Tanabe Plastics) with an L / D ratio of 28. Specifically, pellets were melt-kneaded in the 30 mmφ extruders and extruded through a multi-manifold T-die (die width: 250 mm, manufactured by the Plastics Engineering Research Institute) to prepare laminates with a die setting temperature of 270°C and a chill roll temperature of 50°C, with layer thicknesses of outer layer 1 / intermediate layer / outer layer 2 = 20 / 60 / 60 μm. 3-2. Evaluation of peeling: The prepared laminate was cut into a width of 100 mm, and one end of the laminate was immersed in Echinacene (manufactured by Nippon Alcohol Sales Co., Ltd.) for 1 hour. After that, the Echinacene was wiped off and the laminate was air-dried. Then, a 10 mm width was cut out, and both outer layers of the laminate immersed in Echinacene were attached with packing tape and forcefully peeled off. At this time, it was evaluated whether peeling occurred between the layers of the laminate.

[0051]

[0052]

[0053]

[0054] 1...resin layer, 2...adhesive layer, 10...laminated body

Claims

1. A copolymer containing a fluororesin for use in bonding molded articles, the copolymer containing a monomer unit derived from an olefin monomer having 2 to 8 carbon atoms and a monomer unit having a glycidyl group, and the proportion of the monomer unit having a glycidyl group in the copolymer is 10 mass% or more based on the total mass of the copolymer.

2. The copolymer according to claim 1, wherein the monomer units derived from an olefin monomer having 2 to 8 carbon atoms are monomer units derived from ethylene.

3. The copolymer according to claim 1, wherein the monomer unit having a glycidyl group is a monomer unit derived from glycidyl (meth)acrylate.

4. The copolymer according to claim 1, wherein the proportion of the monomer units having a glycidyl group in the copolymer is 13% by mass or more based on the total mass of the copolymer.

5. The copolymer according to claim 1, wherein the proportion of the monomer units having a glycidyl group in the copolymer is 20% by mass or less, based on the total mass of the copolymer.

6. The copolymer according to claim 1, wherein the fluororesin is a copolymer containing a monomer unit derived from ethylene and a monomer unit derived from tetrafluoroethylene.

7. The copolymer according to claim 1, wherein the melting point of the molded product is 200°C or higher and 260°C or lower.

8. The copolymer according to claim 1, wherein the molded article is a molded article that has not been surface-modified.

9. A laminate comprising a resin layer containing the fluororesin and an adhesive layer formed on the surface of the molded body, wherein the adhesive layer contains the copolymer according to any one of claims 1 to 8.

10. The laminate according to claim 9, which is a film, a multilayer sheet, or a multilayer tube.

11. A method for manufacturing a laminate comprising a resin layer containing a fluororesin and an adhesive layer containing a copolymer and formed on the surface of the resin layer, the method comprising: forming the adhesive layer on the surface of the resin layer by heat sealing; or forming the adhesive layer on the surface of the resin layer by co-extruding a resin containing at least the fluororesin and a resin containing at least the copolymer; wherein the copolymer contains monomer units derived from an olefin monomer having 2 to 8 carbon atoms and monomer units having a glycidyl group, and the proportion of the monomer units having a glycidyl group in the copolymer is 10 mass% or more based on the total mass of the copolymer.

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