Coatings, coating films, laminates, and flexible flat cables

Abstract

The present invention discloses a coating, which comprises: (A) 100 parts by mass of acid-modified polypropylene; and (B) 450 parts by mass or more of an organic solvent, wherein the melting point of the acid-modified polypropylene (A) is below 90°C; (B) the organic solvent is composed of 80 to 99% by mass of (B1) an aromatic hydrocarbon solvent; and (B2) 20 to 1% by mass of one or more selected from the group consisting of an ester solvent, a ketone solvent, and an alcohol solvent, wherein the sum of the proportion of the component (B1) and the proportion of the component (B2) is 100% by mass. The coating may further comprise 0.1 to 20 parts by mass of a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule (C). The compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule (C) may be a compound having no hydrolyzable group. The present invention also discloses a coating film of the coating, a laminate comprising the coating film and a substrate film, and a flexible flat cable comprising the laminate.

Description

Technical Field

[0001] The present invention relates to a coating material, a coating film, a laminate and a flexible flat cable. Background Art

[0002] Conventionally, flexible flat cables are used for wiring of electronic devices such as computers, image display devices, mobile phones, smart phones, printers, car navigation systems, and copiers. Flexible flat cables are cables having a structure in which a plurality of arranged conductors are sandwiched and covered by an insulating adhesive laminate having an adhesive resin composition layer, typically a polyester hot-melt adhesive layer, provided on one surface of an insulating base film.

[0003] In recent years, flexible flat cables are used for electronic devices such as millimeter wave radars and car cameras that are arranged outside the car. They are also used for household appliances such as rice cookers, electric kettles, and microwave ovens that generate water vapor, and other uses that assume high temperature and humidity environments. However, the use of polyester resin compositions as adhesive resin compositions has insufficient moisture and heat resistance. It is found that if used in a high temperature and humidity environment, the laminate will peel off from the conductor and even have the problem of conductor exposure. Therefore, the applicant proposes to use a polyolefin resin composition instead of a polyester resin composition as an adhesive resin composition (for example, refer to Japanese Patent International Publication No. 2016 / 181880 and Japanese Patent International Publication No. 2018 / 042995 (Patent Documents 1 and 2)). In addition, Japanese Patent International Publication No. 2016 / 047289, Japanese Patent International Publication No. 2014 / 185332, and Japanese Patent International Publication No. 2019 / 171709 (Patent Documents 3 to 5) also disclose other polyolefin resin compositions used as adhesive resin compositions.

[0004] In recent years, in order to meet higher rated temperature standards, the use of polyethylene naphthalate resin film, polyimide resin film, polyphenylene sulfide resin film, etc. as an insulating base film instead of polyethylene terephthalate resin film has been discussed. However, there is a problem that the adhesive resin composition layer of the polyolefin resin composition and the polyethylene naphthalate resin film have insufficient interlayer bonding strength.

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent International Publication No. 2016 / 181880

[0007] Patent Document 2: Japanese Patent International Publication No. 2018 / 042995

[0008] Patent Document 3: Japanese Patent International Publication No. 2016 / 047289

[0009] Patent Document 4: Japanese Patent International Publication No. 2014 / 185332

[0010] Patent Document 5: Japanese Patent International Publication No. 2019 / 171709 Summary of the invention

[0011] Problems to be solved by the invention

[0012] An object of the present invention is to provide a novel coating material not found in the prior art, and a coating film, a laminate, and a flexible flat cable formed of the coating material.

[0013] Another object of the present invention is to provide a coating material as an anchor coating layer that can form a preferable coating film, and a coating film, a laminate, and a flexible flat cable formed of the coating material.

[0014] Technical means of solving problems

[0015] Various aspects of the invention are described below.

[0016] [1]. A coating comprising:

[0017] (A) 100 parts by mass of acid-modified polypropylene; and

[0018] (B) 450 parts by mass or more of an organic solvent,

[0019] The melting point of the acid-modified polypropylene (A) is below 90°C;

[0020] The above-mentioned (B) organic solvent is composed of:

[0021] (B1) 80 to 99% by mass of an aromatic hydrocarbon solvent; and

[0022] (B2) 20 to 1% by mass of one or more solvents selected from the group consisting of ester solvents, ketone solvents and alcohol solvents,

[0023] The sum of the blending ratio of the above-mentioned (B1) aromatic hydrocarbon solvent and the above-mentioned (B2) solvent is 100% by mass.

[0024] [2] The coating material described in item [1], further comprising (C) 0.1 to 20 parts by mass of a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule.

[0025] [3] The coating material described in item [2], wherein the compound (C) having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule is a compound having no hydrolyzable group.

[0026] [4] The coating material described in any one of items [1] to [3], wherein the organic solvent (B) comprises 92 to 99% by mass of (B1) an aromatic hydrocarbon solvent; and

[0027] (B2) 8 to 1% by mass of one or more solvents selected from the group consisting of ester solvents, ketone solvents, and alcohol solvents.

[0028] [5]. The coating material described in item [4], wherein the above-mentioned (B2) is one or more selected from the group consisting of ester solvents, ketone solvents and alcohol solvents, has a water solubility of 5 g or more, or is water-soluble.

[0029] [6] The coating material according to any one of items [1] to [5], wherein the acid-modified amount of the acid-modified polypropylene (A) is 0.1 to 2.8% by mass.

[0030] [7]. A coating film formed by using the coating material according to any one of items [1] to [6].

[0031] [8] The coating film described in item [7] has a thickness of 0.05 μm or more and less than 5 μm.

[0032] [9] A coating film formed by using a coating material containing 70% by mass or more of (A) acid-modified polypropylene as a solid content, and having a thickness of 0.05 μm or more and less than 5 μm.

[0033]

[10] The coating film according to item [9], wherein the coating material containing 70% by mass or more of (A) acid-modified polypropylene as a solid component comprises:

[0034] (A) 100 parts by mass of acid-modified polypropylene; and

[0035] (C) 0.1 to 20 parts by mass of a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule.

[0036]

[11] . The coating film described in item

[10] , wherein the compound (C) having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule is a compound having no hydrolyzable group.

[0037]

[12] . A laminate comprising:

[0038] a substrate film; and

[0039] The coating film according to any one of items [7] to

[11] is formed on at least one surface of the substrate film.

[0040] The coating film is formed directly on the surface of the substrate film.

[0041]

[13] . The laminate described in item

[12] , wherein the substrate film is a polyethylene naphthalate resin film, a polyimide resin film, or a polyphenylene sulfide resin film.

[0042]

[14] . The laminate described in item

[12] or

[13] , wherein the coating film and the adhesive resin layer are provided in this order on at least one surface of the substrate film.

[0043]

[15] . The laminate described in item

[14] , wherein the adhesive resin layer is a polyolefin hot-melt adhesive layer.

[0044]

[16] . A flexible flat cable comprising the laminate according to any one of

[12] to

[15] .

[0045] Effects of the Invention

[0046] According to the present invention, a new coating material not available in the prior art, and a coating film, a laminate and a flexible flat cable formed by the coating material are provided. The preferred coating material of the present invention may be a coating material having further good storage stability. The preferred coating film of the present invention may exhibit good bonding strength to any one of an adhesive resin composition layer of a polyolefin resin composition, a polyethylene naphthalate resin film, a polyimide resin film and a polyphenylene sulfide resin film. The preferred coating film of the present invention may further exhibit good bonding strength to any one of an adhesive resin composition layer of a polyolefin resin composition, a polyethylene naphthalate resin film, a polyimide resin film and a polyphenylene sulfide resin film under a high temperature and high humidity environment.

[0047] The coating material of the present invention can be a coating material suitable for forming an anchor coating. The preferred coating material of the present invention can be preferably used as a coating material for forming an anchor coating for improving the interlayer bonding strength between an adhesive resin composition layer of a polyolefin resin composition for a flexible flat cable and a polyethylene naphthalate resin film or the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a conceptual diagram showing a cross section of one embodiment of the flexible flat cable of the present invention.

[0049] Explanation of symbols

[0050] 1, 1': Base film

[0051] 2, 2': Coating film of the present invention as anchor coating

[0052] 3, 3': Flame retardant hot melt adhesive layer

[0053] 4, 4', 4", 4'': Flat wire for conductors DETAILED DESCRIPTION

[0054] In this specification, the term "resin" is used as a term that also includes a resin mixture containing two or more resins and a resin composition containing components other than resins.

[0055] In this specification, the terms "film" and "sheet" can be used interchangeably or interchangeably. In this specification, the terms "film" and "sheet" are used for items that can be rolled up industrially. The term "plate" is used for items that cannot be rolled up industrially. In addition, in this specification, sequentially stacking a certain layer with other layers includes both directly stacking these layers and stacking them with one or more other layers such as anchor coatings between these layers.

[0056] In this specification, the term "above" in a numerical range is used to mean a certain value or exceeding a certain value. For example, 20% or more means 20% or more than 20%. The term "below" in a numerical range is used to mean a certain value or less than a certain value. For example, 20% or less means 20% or less than 20%. In addition, the symbol "to" in a numerical range is used to mean a certain value, exceeding a certain value and less than another certain value, or another certain value. Among them, another certain value is a value greater than a certain value. For example, 10-90% means 10%, exceeding 10% and less than 90%, or 90%. Furthermore, the upper limit and lower limit of the numerical range can be arbitrarily combined, and any combination of embodiments can be read. For example, from the description of the numerical range of a certain characteristic "usually more than 10%, preferably more than 20%. On the other hand, it is usually less than 40%, preferably less than 30%." or "usually 10-40%, preferably 20-30%.", it can be read that the numerical range of the certain characteristic is 10-40%, 20-30%, 10-30% or 20-40% in one embodiment.

[0057] Except for the examples, or unless otherwise specified, all numerical values ​​used in this specification and claims should be understood as modified by the term "about". Without limiting the application of the doctrine of equivalents to the claims, each numerical value should be interpreted in light of significant figures and by applying ordinary rounding methods.

[0058] In this specification, terms regarding specific shapes or geometric conditions such as parallel, orthogonal, and perpendicular include substantially the same conditions in addition to the strict meanings.

[0059] 1. Paint

[0060] The coating of the present invention comprises: (A) acid-modified polypropylene. In one embodiment, the coating of the present invention comprises: (A) acid-modified polypropylene and (B) an organic solvent. In a preferred embodiment, the component (B) organic solvent consists of (B1) an aromatic hydrocarbon solvent and (B2) one or more selected from the group consisting of ester solvents, ketone solvents and alcohol solvents. In another preferred embodiment, the coating of the present invention comprises: (A) acid-modified polypropylene and (B) an organic solvent, wherein (B) organic solvent consists of (B1) an aromatic hydrocarbon solvent and (B2) one or more selected from the group consisting of ester solvents, ketone solvents and alcohol solvents, and may not contain an organic solvent other than the (B) organic solvent.

[0061] In another embodiment, the coating of the present invention contains 70% by mass or more of (A) acid-modified polypropylene as a solid component. In a preferred embodiment, the coating of the present invention contains (A) acid-modified polypropylene and (B) an organic solvent, wherein (B) the organic solvent is composed of (B1) an aromatic hydrocarbon solvent and (B2) one or more selected from the group consisting of an ester solvent, a ketone solvent, and an alcohol solvent, and contains 70% by mass or more of (A) acid-modified polypropylene as a solid component.

[0062] In a preferred embodiment, the coating of the present invention further comprises (C) a curing agent (preferably a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule). In a preferred embodiment, the coating of the present invention comprises (A) acid-modified polypropylene, (B) an organic solvent and (C) a curing agent (preferably a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule), wherein (B) the organic solvent is composed of (B1) an aromatic hydrocarbon solvent and (B2) one or more selected from the group consisting of an ester solvent, a ketone solvent and an alcohol solvent. In another preferred embodiment, the coating of the present invention comprises (A) acid-modified polypropylene, (B) an organic solvent, and (C) a curing agent (preferably a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule), wherein the (B) organic solvent is composed of (B1) an aromatic hydrocarbon solvent and (B2) one or more selected from the group consisting of an ester solvent, a ketone solvent, and an alcohol solvent, and contains 70% by mass or more of (A) acid-modified polypropylene as a solid content. Each component is described below.

[0063] (A) Acid-modified polypropylene

[0064] The coating of the present invention contains the above-mentioned component (A) acid-modified polypropylene. The above-mentioned component (A) acid-modified polypropylene is a polypropylene resin copolymerized with unsaturated carboxylic acid or unsaturated carboxylic acid derivatives, usually graft copolymerized (hereinafter, sometimes referred to as "acid-modified"). Since the above-mentioned component (A) acid-modified polypropylene is copolymerized with unsaturated carboxylic acid or unsaturated carboxylic acid derivatives, it has the effect of showing good bonding strength to any of polyethylene naphthalate resin films, polyimide resin films and polyphenylene sulfide resin films. In addition, since the above-mentioned component (A) acid-modified polypropylene is a polypropylene resin, it has the effect of showing good bonding strength to the adhesive resin composition layer of the polyolefin resin composition.

[0065] The melting point of the acid-modified polypropylene of the above-mentioned component (A) can be appropriately selected from the viewpoint of solubility when preparing the coating and the viewpoint of the adhesive strength of the coating film under a high temperature and high humidity environment. The melting point of the acid-modified polypropylene of the above-mentioned component (A) can be generally 90°C or less, preferably 85°C or less, and more preferably 82°C or less, from the viewpoint of solubility when preparing the coating. On the other hand, its melting point can be preferably 60°C or more, more preferably 68°C or more, and even more preferably 70°C or more, from the viewpoint of the adhesive strength of the coating film under a high temperature and high humidity environment.

[0066] In this specification (including the examples), the melting point is calculated according to JIS K7121-1987, using a differential scanning calorimeter (DSC measuring device), by measuring the second melting curve (melting curve measured during the last heating process) by keeping at 30°C for 5 minutes, heating to 240°C at 20°C / min, keeping at 240°C for 5 minutes, cooling to -50°C at -10°C / min, keeping at -50°C for 5 minutes, and heating to 240°C at 10°C / min. At this time, the above melting point is the peak temperature of the dissolution peak appearing in the above second melting curve. It should be noted that when more than two dissolution peaks are observed, the peak temperature of the dissolution peak with the largest peak height is set as the melting point.

[0067] The acid modification amount of the acid-modified polypropylene of the component (A) (the content of the structural unit derived from the copolymerized unsaturated carboxylic acid or unsaturated carboxylic acid derivative relative to the total mass of the acid-modified polypropylene (100 mass%)) can be appropriately determined from the viewpoint of the adhesive strength of the coating film and the storage stability of the coating, taking into account the type of the copolymerized unsaturated carboxylic acid or unsaturated carboxylic acid derivative and the types of other components contained in the coating. Typically, the acid modification amount of the acid-modified polypropylene of the component (A) may be usually 0.1 mass% to 5.0 mass%, preferably 0.1 mass% to 3.5 mass%, 0.1 mass% to 3.0 mass%, 0.5 mass% to 5.0 mass%, 0.5 mass% to 3.5 mass%, 0.5 mass% to 3.0 mass%, 1.0 mass% to 5.0 mass%, 1.0 mass% to 3.5 mass%, or 1.0 mass% to 3.0 mass%. The copolymerized unsaturated carboxylic acid derivative is maleic anhydride. In the case of a compound having two or more epoxy groups in one molecule as the above-mentioned component (C) curing agent, from the viewpoint of the bonding strength of the coating film, the acid-modified amount of the above-mentioned component (A) acid-modified polypropylene can usually be 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and more preferably 1.5% by mass or more. On the other hand, from the viewpoint of the storage stability of the coating, the acid-modified amount of the above-mentioned component (A) acid-modified polypropylene can usually be 5.0% by mass or less, preferably 3.5% by mass or less, more preferably 2.8% by mass or less, and more preferably 2.5% by mass or less. It should be noted that, in the case where the above-mentioned component (A) acid-modified polypropylene is a mixture of two or more acid-modified polypropylene resins, the acid-modified amount of the mixture can be within the above range. In addition, if the acid-modified polypropylene of the component (A) is contained in a small amount (usually less than 50% by mass, preferably 20% by mass or less, and more preferably 10% by mass or less), it can be mixed with an un-acid-modified polypropylene resin (acid-modified amount 0% by mass). In this case, the acid-modified amount of the mixture can be within the above range.

[0068] Can be used 13 The acid modification amount of the acid-modified polypropylene of the component (A) can be determined by C-NMR spectroscopy. For example, a nuclear magnetic resonance device can be used to measure the acid modification amount of the acid-modified polypropylene under the following conditions: 13 C-NMR spectroscopy.

[0069] Sample concentration: 60 mg / NMR solvent 0.6 mL

[0070] NMR solvent: a mixed solvent of 1,2,4-trichlorobenzene / benzene-d6 (90 vol% / 10 vol%)

[0071] Measuring temperature: 130℃

[0072] Pulse width: 45° (5.0μs)

[0073] Repeat time: 4 seconds

[0074] The method for producing the acid-modified polypropylene of the component (A) is not particularly limited, and it can be produced by a known method. As a method for producing the acid-modified polypropylene of the component (A), for example, a method of producing the acid-modified polypropylene of the component (A) by melt-kneading a resin composition comprising (p) a polypropylene resin, (q) one or more selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid derivatives, and (r) an organic peroxide, by grafting the component (q) onto the component (p). At this time, from the viewpoint that the components (q) and (r) react completely and no unreacted components remain in the produced acid-modified polypropylene of the component (A), the melt-kneading is preferably carried out at a temperature higher than the 1-minute half-life temperature of the component (r) for more than 1 minute, and more preferably at a temperature higher than the 1-minute half-life temperature of the component (r) for more than 2 minutes. The 1-minute half-life temperature is a temperature at which the half-life becomes 1 minute, that is, it means that when the -OO- bond in the component (r) is decomposed at this temperature, the time required for the current concentration of the bond to become half of the initial concentration is 1 minute.

[0075] Examples of the above-mentioned component (p) polypropylene resin include propylene homopolymers, copolymers (including block copolymers and random copolymers) of propylene and other small amounts of α-olefins (e.g., ethylene, 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene, etc.), and the like.

[0076] The melting point of the component (p) polypropylene resin may be preferably 60 to 90°C, more preferably 68 to 90°C or 68 to 85°C, and even more preferably 70 to 85°C or 70 to 82°C, from the viewpoint of making the melting point of the component (A) acid-modified polypropylene within the above preferred range. Such a polypropylene resin may have a structure in which the stereoregularity of the propylene chain is low (mm fraction is usually about 50 to 80 mol%), or a random copolymerization of a large amount of α-olefin as a comonomer (depending on the type of α-olefin, usually about 5 to 35 mol%), or abnormal insertion (2-1 insertion or 1-3 insertion) of propylene is contained in a large amount (usually about 5 to 35 mol%), or a combination of these. The definition and measurement method of the melting point are as described above.

[0077] As the polypropylene resin of the component (p), these may be used alone or in mixture of two or more.

[0078] As the unsaturated carboxylic acid of the above-mentioned component (q), for example, maleic acid, itaconic acid, fumaric acid, acrylic acid and methacrylic acid can be listed. As the unsaturated carboxylic acid derivative of the above-mentioned component (q), for example, a compound having one or more carboxyl groups of an ester of an unsaturated polycarboxylic acid such as maleic acid monoester, itaconic acid monoester and fumaric acid monoester; an anhydride of an unsaturated carboxylic acid such as maleic anhydride, itaconic anhydride and fumaric anhydride; an unsaturated carboxylic acid diester such as maleic acid diester, itaconic acid diester and fumaric acid diester; an alkyl acrylate such as methyl acrylate; and an alkyl methacrylate such as methyl methacrylate. As one or more selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid derivatives of the above-mentioned component (q), from the viewpoint of the bonding strength of the coating film, preferably, an unsaturated carboxylic acid, a compound having one or more carboxyl groups of an ester of an unsaturated polycarboxylic acid and an anhydride of an unsaturated carboxylic acid are used. More preferably, an unsaturated carboxylic acid and an anhydride of an unsaturated carboxylic acid are used, and more preferably, maleic anhydride is used.

[0079] As the component (q) described above, one or more selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid derivatives, one or a mixture of two or more thereof may be used.

[0080] The amount of one or more selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid derivatives as the component (q) can be appropriately determined from the viewpoints that the component (q) is completely reacted during melt kneading, no unreacted acid remains in the produced component (A) acid-modified polypropylene, and that the acid modification amount of the component (A) acid-modified polypropylene is within the above-mentioned preferred range. The amount of one or more selected from the group consisting of unsaturated carboxylic acids and unsaturated carboxylic acid derivatives as the component (q) can be generally 0.1 to 5 parts by mass, preferably 0.5 to 3.5 parts by mass, more preferably 1 to 2.8 parts by mass, and even more preferably 1.5 to 2.5 parts by mass, relative to 100 parts by mass of the component (p) polypropylene resin.

[0081] Examples of the organic peroxide as the component (r) include diisopropylbenzene peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 1,3-bis(tert-butylperoxyisopropyl)benzene, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 4,4-bis(tert-butylperoxy)butyl valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, (2,4-dichlorobenzoyl) peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and tert-butylisopropylbenzene peroxide. As the organic peroxide of the component (r), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3-yl are preferred from the viewpoint of adhesive strength.

[0082] As the organic peroxide of the component (r), these may be used alone or in mixture of two or more.

[0083] The amount of the organic peroxide as the component (r) can be appropriately determined from the viewpoints of completely reacting the components (q) and (r) so that no unreacted product remains in the acid-modified polypropylene as the component (A) produced and suppressing the decrease in the molecular weight of the polypropylene resin as the component (p). The amount of the organic peroxide as the component (r) can be generally 0.05 to 1.5 parts by mass, preferably 0.2 to 1.3 parts by mass, and more preferably 0.5 to 1.0 parts by mass, relative to 100 parts by mass of the polypropylene resin as the component (p).

[0084] In another embodiment, the coating of the present invention preferably contains 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more of the acid-modified polypropylene as a solid content. By using such a coating, a coating film can be formed that exhibits good bonding strength to any of the adhesive resin composition layers of the polyethylene naphthalate resin film, the polyimide resin film, the polyphenylene sulfide resin film, and the polyolefin resin composition.

[0085] (B) Organic solvents

[0086] In one embodiment, the coating of the present invention further comprises the above-mentioned component (B) organic solvent in addition to the above-mentioned component (A) acid-modified polypropylene. The above-mentioned component (B) organic solvent is not particularly limited as long as it helps dissolve the above-mentioned component (A) acid-modified polypropylene. Examples of the above-mentioned component (B) organic solvent include, for example, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, alcohol solvents, ketone solvents, ester solvents, and halogen solvents in which at least one hydrogen atom of these solvents is replaced by a halogen atom such as a chlorine atom.

[0087] As the organic solvent of the component (B), these may be used alone or in mixture of two or more.

[0088] In a typical embodiment, the organic solvent of component (B) may be composed of (B1) an aromatic hydrocarbon solvent and (B2) one or more selected from the group consisting of an ester solvent, a ketone solvent and an alcohol solvent (hereinafter, sometimes referred to as "ester solvent, etc."). In a preferred embodiment, in the coating of the present invention, the content of organic solvents other than (B1) and (B2) in the organic solvent of component (B) may be preferably 10% by mass or less, more preferably 4% by mass or less, even more preferably 1% by mass or less, and most preferably 0% by mass (that is, the organic solvent of component (B) does not contain any organic solvents other than (B1) and (B2)).

[0089] The aromatic hydrocarbon solvent of the component (B1) can dissolve the acid-modified polypropylene of the component (A), but has the problem of low storage stability (easy to gel). In addition, the ester solvent of the component (B2) can hardly dissolve the acid-modified polypropylene of the component (A). That is, the ester solvent of the component (B2) is a poor solvent for the acid-modified polypropylene of the component (A). It is common technical knowledge to use a good solvent to improve the storage stability of the coating, but surprisingly, by making it contain a small amount of a poor solvent, the storage stability can be improved (the above problem can be solved).

[0090] Although not intending to be bound by theory, the acid-modified part of the acid-modified polypropylene of the above-mentioned component (A) has low compatibility with the above-mentioned component (B1) aromatic hydrocarbon-based solvent, so the acid-modified parts gather together to enhance interaction and promote gelation. Here, when a small amount of the above-mentioned component (B2) ester-based solvent is added, it is found that the ester group, ketone group and hydroxyl group of the above-mentioned component (B2) gather around the acid-modified part of the above-mentioned component (A), which can expand the distance between the acid-modified parts and inhibit gelation.

[0091] The aromatic hydrocarbon solvent of the component (B1) is a hydrocarbon solvent having an aromatic ring. The aromatic hydrocarbon solvent of the component (B1) is not particularly limited, but examples thereof include toluene, xylene, o-xylene and benzene. Among these, the component (B1) preferably has an aromatic ring and does not have an ester group, a ketone group and a hydroxyl group (including both alcoholic hydroxyl groups and phenolic hydroxyl groups), and is more preferably toluene, xylene and o-xylene, and even more preferably toluene, from the viewpoint of the solubility of the acid-modified polypropylene of the component (A) when preparing the coating and the storage stability of the coating.

[0092] As the aromatic hydrocarbon solvent of the component (B1), one kind or a mixture of two or more kinds thereof may be used.

[0093] The ester solvent of the above-mentioned component (B2) is an aliphatic (without aromatic ring) hydrocarbon compound having one or more ester groups in one molecule, and is a liquid compound under standard conditions (temperature 25°C, pressure 100KPa. The same applies hereinafter). Examples of the above-mentioned ester solvent include acetates such as methyl acetate, ethyl acetate, n-propyl acetate, 1-methylethyl acetate, n-butyl acetate, 2-methylpropyl acetate, 1-methylpropyl acetate, and tert-butyl acetate; and lactic acid esters such as ethyl lactate (ethyl 2-hydroxypropionate), ethyl lactate (ethyl 2-hydroxypropionate), and butyl lactate (n-butyl 2-hydroxypropionate).

[0094] The ketone solvent of the component (B2) is an aliphatic (non-aromatic) hydrocarbon compound having one or more ketone groups in one molecule, and is a liquid compound under standard conditions. Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, and diacetone alcohol.

[0095] The alcohol solvent of the component (B2) is an aliphatic (non-aromatic) hydrocarbon compound having one or more alcoholic hydroxyl groups in one molecule, and is a liquid compound under standard conditions. Examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol (isopropanol), 1-butanol, 2-methyl-1-propanol (isobutanol), 2-butanol, 2-methyl-2-propanol (tert-butanol), 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1,3-butanediol, 1,4-butanediol, 2-ethylhexanol, ethylene glycol, propylene glycol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether.

[0096] It should be noted that ester solvents having an alcoholic hydroxyl group such as methyl lactate, ethyl lactate, and butyl lactate, and ketone solvents having an alcoholic hydroxyl group such as diacetone alcohol are compounds that can also be classified as alcohol solvents.

[0097] The water solubility of the above-mentioned component (B2) ester solvent, etc., may preferably be 5 g or more, more preferably 8 g or more, from the viewpoint of the storage stability of the coating. The above-mentioned component (B2) ester solvent, etc., may be water-soluble from the viewpoint of the storage stability of the coating. The water solubility is the mass (unit: g) dissolved in 100 mL of pure water at a temperature of 20°C (the mixed liquid can maintain a uniform appearance). In addition, water solubility means that it can be mixed with pure water at a temperature of 20°C in any proportion (the mixed liquid maintains a uniform appearance). Examples of the ester solvent of the component (B2) include methyl acetate (water solubility: 24.4 g), ethyl acetate (water solubility: 8.3 g), acetone (water soluble), methyl ethyl ketone (water solubility: 27.5 g), methanol (water soluble), ethanol (water soluble), 1-propanol (water soluble), 2-propanol (water soluble), 1-butanol (water solubility: 7.7 g), 2-methyl-1-propanol (water solubility: 10 g), 2-butanol (water solubility: 26 g), 2-methyl-2-propanol (water soluble), 1,3-butanediol (water soluble), and 1,4-butanediol (water soluble).

[0098] As the ester solvent of the component (B2), these may be used alone or in mixture of two or more.

[0099] In the embodiment where the organic solvent of component (B) is composed of the aromatic hydrocarbon solvent of component (B1) and the ester solvent of component (B2), the proportion of the aromatic hydrocarbon solvent of component (B1) in the organic solvent of component (B) can be appropriately determined from the viewpoint of dissolving the acid-modified polypropylene of component (A) and the storage stability of the coating. The proportion of the aromatic hydrocarbon solvent of component (B1) in the organic solvent of component (B) can be generally 80% by mass or more, preferably 86% by mass or more, and more preferably 92% by mass or more, from the viewpoint of dissolving the acid-modified polypropylene of component (A), taking the sum of the proportion of the proportion of the component (B1) and the proportion of the component (B2) as 100% by mass. That is, the proportion of the ester solvent of component (B2) in the organic solvent of component (B) can be generally 20% by mass or less, preferably 14% by mass or less, and more preferably 8% by mass or less, from the viewpoint of dissolving the acid-modified polypropylene of component (A). On the other hand, the proportion of the aromatic hydrocarbon solvent of the component (B1) in the organic solvent of the component (B) may be generally 99% by mass or less, preferably 98% by mass or less, from the viewpoint of the storage stability of the coating. That is, the proportion of the ester solvent of the component (B2) in the organic solvent of the component (B) may be generally 1% by mass or more, preferably 2% by mass or more, from the viewpoint of the storage stability of the coating.

[0100] The amount of the organic solvent of the component (B) may be appropriately determined from the viewpoints of dissolving the acid-modified polypropylene of the component (A), the storage stability of the coating, the coating properties when forming a thin coating film, and the operability of the drying process when forming the coating film. The amount of the organic solvent of the component (B) may be generally 450 parts by mass or more, preferably 500 parts by mass or more, and more preferably 550 parts by mass or more, relative to 100 parts by mass of the component (A), from the viewpoints of dissolving the acid-modified polypropylene of the component (A), the storage stability of the coating, and the coating properties when forming a thin coating film. On the other hand, the amount may be preferably 2000 parts by mass or less, more preferably 1200 parts by mass or less, and even more preferably 800 parts by mass or less, from the viewpoint of operability in the drying process when forming the coating film.

[0101] (C) Curing agent

[0102] In one embodiment, the coating of the present invention includes the above-mentioned component (C) curing agent. The above-mentioned component (C) curing agent is a compound having two or more functional groups that can form a chemical bond with a carboxyl group in one molecule. The above-mentioned component (C) curing agent, when the above-mentioned component (A) acid-modified polypropylene is a component having a carboxyl group, forms a chemical bond with the carboxyl group in the above-mentioned component (A), imparts a moderate hardness to the coating film, and plays a role in suppressing the reduction of the bonding strength of the coating film under a high temperature and high humidity environment. That is, this embodiment is particularly effective when the above-mentioned component (A) acid-modified polypropylene is a component having a carboxyl group or is modified with an anhydride of an unsaturated carboxylic acid such as maleic anhydride.

[0103] As the functional group that can form chemical bonding with the above-mentioned carboxyl group, for example, epoxy group, isocyanate group and amine group etc. can be listed. Among these, as the functional group that can form chemical bonding with the above-mentioned carboxyl group, from the viewpoint of the storage property of coating and the bonding strength of coating film, epoxy group and isocyanate group are preferably used, and epoxy group is more preferably used.

[0104] Examples of the curing agent as component (C) include compounds having two or more epoxy groups in one molecule, such as 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-diphenylenediamine, diglycidyl aniline, diglycidylamine, bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexanediol diglycidyl ether, and trimethylolpropane triglycidyl ether.

[0105] In addition, examples of the curing agent as the component (C) include compounds having two isocyanate groups in one molecule, such as hexamethylene diisocyanate, isophorone diisocyanate, toluene diisocyanate and methylene bis-4-cyclohexyl isocyanate; polyisocyanates having two or more isocyanate groups in one molecule, such as trimethylolpropane adducts of toluene diisocyanate, trimethylolpropane adducts of hexamethylene diisocyanate, trimethylolpropane adducts of isophorone diisocyanate, isocyanurate forms of toluene diisocyanate, isocyanurate forms of hexamethylene diisocyanate, isocyanurate forms of isophorone diisocyanate and biuret forms of hexamethylene diisocyanate; and compounds having two or more isocyanate groups in one molecule, such as urethane crosslinking agents such as blocked isocyanates of the above-mentioned polyisocyanates.

[0106] The curing agent of component (C) preferably has no hydrolyzable group from the viewpoint of the adhesive strength of the coating film under a high temperature and high humidity environment. Examples of the hydrolyzable group include alkoxy groups such as methoxy, ethoxy, propoxy and isopropoxy; acyloxy groups such as acetoxy; and halogen groups such as chloro.

[0107] The number of functional groups capable of forming a chemical bond with the carboxyl group in one molecule of the above-mentioned component (C) curing agent can be appropriately determined in consideration of the type of functional groups, from the viewpoint of storage stability of the coating, from the viewpoint of suppressing the reduction in the bonding strength of the coating film under a high temperature and high humidity environment, and from the viewpoint of stopping the hardening of the coating film within an appropriate range. The number of functional groups capable of forming a chemical bond with the carboxyl group in one molecule of the above-mentioned component (C) curing agent can generally be 2 to 20, preferably 3 to 12, when the functional group is an epoxy group. The number of functional groups capable of forming a chemical bond with the carboxyl group in one molecule of the above-mentioned component (C) curing agent can generally be 2 to 20, preferably 3 to 12, when the functional group is an isocyanate group.

[0108] As the curing agent of the component (C), these may be used alone or in mixture of two or more.

[0109] The amount of the curing agent of the component (C) can be appropriately determined in consideration of its type, from the viewpoint of obtaining the effect of use as a curing agent, from the viewpoint of stopping the hardening of the coating film within a suitable range, and from the viewpoint of not causing gelling before applying the coating after mixing the component (C). The amount of the curing agent of the component (C) can be generally 0.1 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 1 parts by mass or more, and more preferably 2 parts by mass or more, relative to 100 parts by mass of the acid-modified polypropylene of the component (A), from the viewpoint of obtaining the effect of use as a curing agent. On the other hand, the amount can be generally 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, from the viewpoint of stopping the hardening of the coating film within a suitable range, and from the viewpoint of not causing gelling before applying the coating after mixing the component (C).

[0110] The coating of the present invention may further contain any component other than the above-mentioned component (A) acid-modified polypropylene, the above-mentioned component (B) organic solvent, and the above-mentioned component (C) curing agent as required, within the scope not contrary to the purpose of the present invention. As the optional component, for example, thermoplastic resins other than the above-mentioned component (A) acid-modified polypropylene; pigments, inorganic fillers, organic fillers, and resin fillers; and additives such as lubricants, antioxidants, weather stabilizers, heat stabilizers, mold release agents, antistatic agents, and surfactants, etc. In one embodiment, the coating of the present invention does not contain any component other than the above-mentioned component (A) acid-modified polypropylene, the above-mentioned component (B) organic solvent, and the above-mentioned component (C) curing agent. In another embodiment, the coating of the present invention does not contain any component other than the above-mentioned component (A) acid-modified polypropylene; pigments, inorganic fillers, organic fillers, and resin fillers; and any one or more additives selected from lubricants, antioxidants, weather stabilizers, heat stabilizers, mold release agents, antistatic agents, and surfactants.

[0111] Examples of thermoplastic resins other than the acid-modified polypropylene of the component (A) include methacrylate alkyl esters such as methyl methacrylate, ethyl methacrylate and butyl methacrylate; acrylate alkyl esters such as methyl acrylate, ethyl acrylate and butyl acrylate; and copolymers of ethylene and comonomers such as vinyl acetate.

[0112] As the optional component, one or more of these may be used. The amount of the optional component may be generally 0 to 20 parts by mass, preferably 0 to 10 parts by mass, or about 0.01 to 10 parts by mass, relative to 100 parts by mass of the acid-modified polypropylene (A).

[0113] The coating of the present invention can be obtained by mixing and stirring these components. In the embodiment using the above-mentioned component (C) curing agent, the coating of the present invention is preferably obtained by mixing and stirring the above-mentioned component (C) curing agent before applying the coating after mixing and stirring the components other than the above-mentioned component (C). It can suppress the occurrence of gelation and other problems before applying the coating.

[0114] 2. Coating

[0115] The coating film of the present invention is formed using the coating of the present invention. The coating of any embodiment described in the above item 1 can be used to form the coating film of the present invention. In one embodiment, the coating film of the present invention comprises the above-mentioned component (A) acid-modified polypropylene and the above-mentioned component (B) organic solvent, wherein the above-mentioned component (B) organic solvent is formed using a coating composed of the above-mentioned component (B1) aromatic hydrocarbon solvent, and the above-mentioned component (B2) one or more selected from the group consisting of ester solvents, ketone solvents and alcohol solvents. In another embodiment, the coating film of the present invention is formed using a coating containing 70% by mass or more of the above-mentioned component (A) acid-modified polypropylene as a solid component (that is, a coating in which 70% by mass or more of the total mass of the solid content contained in the coating is acid-modified polypropylene). In another embodiment, the coating film of the present invention is formed using a coating containing 80% by mass or more of the above-mentioned component (A) acid-modified polypropylene as a solid component.

[0116] The coating film of the present invention is formed on any substrate surface using the coating of the present invention. In a typical embodiment, the coating film of the present invention is directly formed on any substrate surface using the coating of the present invention. The coating of the present invention is as described above in "1. Coating". The above-mentioned substrate is described in "3. Laminated body" below.

[0117] Using the coating of the present invention, the method for forming the coating of the present invention on any substrate surface is not particularly limited, and known methods can be used. As the above method, it is possible to list, for example, rod coating, roller coating, gravure coating, reverse coating, touch reverse coating, roller brush, spraying, pneumatic scraper coating, solution coating and steel die coating methods. When using substrate film as the above substrate, from the viewpoint of coating with good productivity using a roll-to-roll method, preferably, for example, rod coating, roller coating, gravure coating, reverse coating, touch reverse coating and steel die coating methods.

[0118] The thickness of the coating film of the present invention can be appropriately determined in consideration of the application, from the viewpoint of bonding strength and the viewpoint of productivity when forming the coating film. The thickness of the coating film of the present invention can generally be 0.05 to 30 μm, preferably 0.05 to 10 μm, 0.05 to 5 μm, 0.1 to 30 μm, 0.1 to 10 μm, or 0.1 to 5 μm.

[0119] The thickness of the coating film of the present invention, when the coating film is used as an anchor coating, particularly when the coating film is used as an anchor coating for improving the interlayer bonding strength between the adhesive resin composition layer of the polyolefin resin composition and the polyethylene naphthalate resin film, polyimide resin film, or polyphenylene sulfide resin film, etc., can be generally less than 5 μm, preferably 4 μm or less, more preferably 2 μm or less, and even more preferably 1.5 μm or less from the viewpoint of bonding strength. On the other hand, in this case, from the viewpoint of productivity when forming the coating film, it can be generally 0.05 μm or more, preferably 0.1 μm or more, and even more preferably 0.3 μm or more.

[0120] Although not intending to be bound by theory, when the coating film is used as an anchor coating, it is found that when the coating film thickness is thin (within the above range), the adhesive resin composition layer of the polyolefin resin composition and the polyethylene naphthalate resin film are integrated, and the interlayer bonding strength becomes high. In addition, from the viewpoint of integrating the two, it is preferred that the coating film thickness is highly uniform, and therefore, the coating coating forming method is more preferred than the melt extrusion film forming method.

[0121] 3. Laminated body

[0122] The laminate of the present invention comprises an arbitrary substrate and a coating of the present invention formed on the surface of the substrate. The coating of any embodiment described in the above item 2 can be used to form the laminate of the present invention. In one embodiment, the laminate of the present invention has a coating of the present invention on at least one surface of a base film as an arbitrary substrate, usually on one surface. In a typical embodiment, the laminate of the present invention has a coating of the present invention on the surface of an arbitrary substrate, and the coating is directly formed on the surface of the above substrate. The coating of the present invention and the method for forming the coating of the present invention on the surface of the above substrate are as described above in "2. Coating".

[0123] Examples of the substrate include base films such as resin films, resin plates, glass films, glass plates, metal foils, metal plates, and resin, glass, or metal bodies having any shapes.

[0124] Examples of the substrate film include, for example, polyvinyl chloride resins; polyester resins such as aromatic polyesters and aliphatic polyesters such as polyethylene terephthalate resin films and polyethylene naphthalate resin films; polyolefin resins such as polyethylene, polypropylene, and polymethylpentene; acrylic resins; polycarbonate resins; poly(meth)acrylic imide resins; styrene resins such as polystyrene, acrylonitrile / butadiene / styrene resin (ABS resin), styrene / ethylene / butadiene / styrene copolymer, styrene / ethylene / propylene / styrene copolymer, and styrene / ethylene / ethylene / propylene / styrene copolymer; cellulose resins such as cellophane, triacetyl cellulose, diacetyl cellulose, and cellulose acetate butyrate; polyvinylidene chloride resins; fluorine-containing resins such as polyvinylidene fluoride; and any resin films such as polyvinyl alcohol, ethylene-vinyl alcohol, polyetheretherketone, nylon, polyamide, polyimide, polyphenylene sulfide, polyurethane, polyetherimide, polysulfone, and polyethersulfone. These films include unoriented films, uniaxially oriented films, and biaxially oriented films. Furthermore, a laminated film in which two or more layers of one or more of these are laminated is included.

[0125] When the laminate of the present invention is used for a flexible flat cable, the substrate film is preferably a polyethylene terephthalate resin film, a polyethylene naphthalate resin film, a polyimide resin film (typically, a polycondensate of an aromatic tetrabasic acid or its derivative and an aromatic polyamine), and a polyphenylene sulfide resin film. When the laminate of the present invention is used for a flexible flat cable with a high rated temperature, the substrate film is preferably a polyethylene naphthalate resin film, a polyimide resin film, and a polyphenylene sulfide resin film, and more preferably a polyethylene naphthalate resin film and a polyphenylene sulfide resin film.

[0126] The thickness of the substrate film can be appropriately determined in consideration of the application of the laminate of the present invention and the various properties required. When the laminate of the present invention is used as an insulating adhesive laminate of a flexible flat cable, the thickness of the substrate film can be appropriately determined from the viewpoint of ensuring the flexibility of the flexible flat cable, the viewpoint of the strength of the flexible flat cable, and the viewpoint of workability when producing the flexible flat cable.

[0127] When the laminate of the present invention is used as an insulating adhesive laminate of a flexible flat cable, the thickness of the substrate film may be generally 10 μm or more, preferably 15 μm or more, and more preferably 20 μm or more from the viewpoint of the strength of the flexible flat cable and the workability when producing the flexible flat cable. On the other hand, in this case, the thickness of the substrate film may be generally 200 μm or less, preferably 100 μm or less, and more preferably 50 μm or less from the viewpoint of ensuring the flexibility of the flexible flat cable.

[0128] When the laminate of the present invention is used as a reinforcing tape for a flexible flat cable (a tape that is attached to the conductor end of a flexible flat cable and is used to reinforce the conductor end of the cable so that it can be connected to an electronic device by a connector), the thickness of the above-mentioned base film can be appropriately determined from the viewpoint of imparting better rigidity and strength to the connector connection and from the viewpoint of processability when the reinforcing tape is cut into a size and shape suitable for connector connection. When the laminate of the present invention is used as a reinforcing tape for a flexible flat cable, the thickness of the above-mentioned base film can be generally 100 μm or more, preferably 125 μm or more, and more preferably 150 μm or more, from the viewpoint of imparting better rigidity and strength to the connector connection. On the other hand, in this case, the thickness of the above-mentioned base film can be generally 500 μm or less, preferably 250 μm or less, from the viewpoint of processability when the reinforcing tape is cut into a size and shape suitable for connector connection.

[0129] When the laminate of the present invention is used as an insulating adhesive laminate of a flexible flat cable, the laminate of the present invention comprises the above-mentioned base film, the coating film of the present invention formed on one surface of the base film, and further, may comprise an adhesive resin layer formed on the surface of the coating film, preferably a hot melt adhesive layer, and more preferably a flame retardant hot melt adhesive layer. The thickness of the hot melt adhesive layer or the flame retardant hot melt adhesive layer is not particularly limited, but can generally be 1 μm to 300 μm, preferably 2 μm to 200 μm.

[0130] As the hot melt adhesive, for example, a polyester hot melt adhesive (thermoplastic polyester resin) or a polyolefin hot melt adhesive (thermoplastic polyolefin resin) or other known hot melt adhesives can be used. As the flame retardant hot melt adhesive, for example, a flame retardant polyester hot melt adhesive (composition comprising a thermoplastic polyester resin and a flame retardant) or a flame retardant polyolefin hot melt adhesive (composition comprising a thermoplastic polyolefin resin and a flame retardant) or other known flame retardant hot melt adhesives can be used. When the flexible flat cable is assumed to be used in a high temperature and humid environment, the above-mentioned polyolefin hot melt adhesive or the above-mentioned flame retardant polyolefin hot melt adhesive is preferably used.

[0131] Preferred adhesives of these adhesives are not particularly limited, but examples thereof include, for example, the adhesive resin composition described in Japanese Patent International Publication No. 2016 / 181880, "An adhesive resin composition comprising: (A) 20 to 70% by mass of an acid-modified polypropylene resin; (B) 20 to 60% by mass of a polypropylene resin; and (C) 2 to 25% by mass of a copolymer of ethylene and one or more comonomers selected from the group consisting of vinyl acetate, alkyl methacrylates, and alkyl acrylates, wherein the above-mentioned components (A), (B), and (C) are selected from the group consisting of vinyl acetate, alkyl methacrylates, and alkyl acrylates. The sum of the components (A) and (B) is 100% by mass. ", or the resin composition described in Japanese Patent International Publication No. 2018 / 042995, "A resin composition for an adhesive layer of a laminate, comprising: (A) 55 to 85% by mass of an acid-modified polypropylene resin; and (B) 45 to 15% by mass of a copolymer of ethylene and one or more comonomers selected from the group consisting of vinyl acetate, alkyl methacrylates and alkyl acrylates, wherein the sum of the above components (A) and the above components (B) is 100% by mass, and the acid modification amount of the above component (A) is 0.5 to 10 mol%". The entirety of the specification, claims, abstract and drawings of Japanese Patent International Publication No. 2016 / 181880 and Japanese Patent International Publication No. 2018 / 042995 are incorporated by reference as disclosed in this specification.

[0132] 4. Flexible flat cable

[0133] The flexible flat cable of the present invention includes the coating film of the present invention. The coating film of any embodiment described in the above item 2 can be used to form the flexible flat cable of the present invention. The flexible flat cable of the present invention includes the laminate of the present invention. The laminate of any embodiment described in the above item 3 can be used to form the flexible flat cable of the present invention. In a typical embodiment, the flexible flat cable of the present invention is produced using an insulating adhesive laminate comprising the above-mentioned base film, a coating film formed on one surface of the base film, and further formed on the surface of the coating film, the above-mentioned hot melt adhesive, preferably the above-mentioned flame-retardant hot melt adhesive layer.

[0134] The method for producing the flexible flat cable of the present invention is not particularly limited and can be produced by a known method. As the above method, for example, the following method can be cited. Use two rolls of the above insulating adhesive laminate (typically, a laminate comprising the above substrate film, the coating film of the present invention formed on one surface of the substrate film, and the above hot melt adhesive, preferably the above flame retardant hot melt adhesive layer formed on the surface of the coating film), use a known flexible flat cable manufacturing device, feed the above insulating adhesive laminate so that it is opposite to the above hot melt adhesive layer, sandwich the parallel flat wires of the conductor therebetween, and heat press with the hot pressing roller of the above device to fuse the above hot melt adhesive layers to each other. In the above insulating adhesive laminate, before the flat wire of the conductor is clamped, the above reinforcing tape can be pasted from the above substrate film side of the above insulating adhesive laminate at the punching position while punching (that is, the laminate of the present invention can be used, or a laminate other than the laminate of the present invention can be used as a reinforcing tape instead). Secondly, the two side ends are cut to a predetermined finished width, and the hole and the reinforcing band are partially cut to complete the flexible flat cable having the conductor end reinforced by the reinforcing band.

[0135] The conductive flat wire is not particularly limited and can be used arbitrarily. From the viewpoint of the sliding property of the flexible flat cable, the conductive flat wire can be a soft copper wire, a hard copper wire, or a tinned or nickel-plated copper wire having a thickness of 12 to 50 μm and a width of 0.2 to 2 mm.

[0136] Figure 1 This is a conceptual diagram showing a cross section of an embodiment of the flexible flat cable of the present invention. On each surface of a base film 1, 1', two sheets of insulating adhesive laminates having a coating film 2 or 2' of the present invention as an anchor coating and a layer 3 or 3' of a flame-retardant hot-melt adhesive on the surface are sandwiched between conductive flat wires 4, 4', 4", and 4'".

[0137] Example

[0138] Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to these examples.

[0139] Raw materials used

[0140] (A) Acid-modified polypropylene

[0141] (A-1) Maleic anhydride-modified polypropylene "TOYO-TAC PMA-KH" (trade name) manufactured by Toyobo Co., Ltd., melting point 77° C., maleic acid modification amount 1.8% by mass.

[0142] (A-2) Maleic anhydride-modified polypropylene "TOYO-TAC PMA-LE" (trade name) manufactured by Toyobo Co., Ltd., melting point 69° C., maleic acid modification amount 3.0% by mass.

[0143] (A-3) Maleic anhydride-modified polypropylene "TOYO-TAC PMA-KE" (trade name) manufactured by Toyobo Co., Ltd., melting point 78°C, maleic acid modification amount 2.9 mass %.

[0144] (A-4) Using a co-rotating twin-screw extruder, a mixture consisting of 100 parts by mass of a propylene / 1-butene random copolymer "TAFMER XM7070" (trade name) manufactured by Mitsui Chemicals, Inc., 1.1 parts by mass of a maleic anhydride guarantee reagent manufactured by Fuji Film Co., Ltd. and 3.0 parts by mass of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (organic peroxide) "PERHEXA25B" (trade name) manufactured by NOF Corporation was fed together through an inlet at the root of the screw, and melt-kneaded under the conditions of a die outlet resin temperature of 200° C. and a stagnation period of 3 minutes (calculated value) to obtain a maleic anhydride-modified polypropylene having a melting point of 75° C. and a maleic acid modification amount of 1.0% by mass.

[0145] (A-5) Maleic anhydride-modified polypropylene "TOYO-TAC PMA-T" (trade name) manufactured by Toyobo Co., Ltd., melting point 94° C., maleic acid modification amount 2.4% by mass.

[0146] (B) Organic solvents

[0147] (B1-1) Toluene.

[0148] (B2-1) Ethyl acetate (water solubility: 8.3 g).

[0149] (B2-2) Methyl ethyl ketone (water solubility: 27.5 g).

[0150] (B2-3) 2-Propanol (water-soluble).

[0151] (C) Curing agent

[0152] (C-1) Methyl ethyl ketone diluted solution of a compound having two or more epoxy groups in one molecule, "HARDLEN LAE-004" (trade name), manufactured by Toyobo Co., Ltd. Solid content (content of the compound): 65% by mass.

[0153] (C-2) "Takenate D-170" (trade name), a compound having two or more isocyanate groups in one molecule manufactured by Mitsui Chemicals, Inc.

[0154] (P) Base film

[0155] (P-1) A polyethylene naphthalate resin film "Theonex Q83C" (trade name) manufactured by Teijin Limited, which has a thickness of 25 μm and one side of which has been subjected to corona discharge treatment.

[0156] (P-2) A polyphenylene sulfide resin film "Torelina #25-3030" (trade name) manufactured by Toray Industries, Ltd., having a thickness of 25 μm and one surface of which was subjected to corona discharge treatment.

[0157] (P-3) A polyimide resin film "Kapton 100H" (trade name) manufactured by Toray Industries, Inc., which has a thickness of 25 μm and one surface of which has been subjected to corona discharge treatment.

[0158] (P-4) A polyethylene terephthalate resin film "EMBLET S25" (trade name) manufactured by Unitika Co., Ltd., having a thickness of 25 μm and one surface of which was subjected to corona discharge treatment.

[0159] The above-mentioned substrate films (P-1) to (P-4) have no anchor coating. That is, as long as a direct coating film is formed on the corona discharge treated surface or any surface other than the back surface, the substrate film and the coating film are in direct contact and laminated.

[0160] (1) Preparation of coating (S-1)

[0161] Into a polypropylene container "IBOY PP wide-mouth bottle 500 ml" (trade name) manufactured by ASONE Co., Ltd., 300 g of a mixture consisting of 100 parts by mass of the above-mentioned component (A-1), 570 parts by mass of the above-mentioned component (B-1) and 30 parts by mass of the above-mentioned component (B-2-1) was added, and the sealing tape was engaged with the thread of the mouth portion of the above-mentioned container and the above-mentioned container cap was tightened. After sealing, mixing and stirring were carried out for 60 minutes using a locking mill at a temperature of 23°C to obtain a coating (S-1).

[0162] The following tests (i) solubility and (ii) storage stability were conducted. The results are shown in Table 1.

[0163] Preparation of coatings (S-2) to (S-14)

[0164] Except that the formulation of the above mixture was changed as shown in Table 1, coatings (S-2) to (S-14) were obtained in the same manner as the above coating (S-1). The following tests (i) solubility and (ii) storage stability were conducted. The results are shown in Table 1. It should be noted that in Table 1 and the following description, the coating (S-1)~(S-14) are collectively referred to as coating (S) situation.

[0165] It was found that the coatings of the following test (i) whose productivity (solubility) was grade B contained many gel-like substances. In addition, for the coatings of the following test (i) whose productivity (solubility) was grade B or grade C, the following tests on storage stability and adhesive strength were omitted.

[0166] (i) Solubility

[0167] The coatings (S-1) to (S-14) were visually checked for any remaining undissolved matter. For those that were visually checked for any remaining undissolved matter, 100 g of the coating was further vacuum filtered using filter paper (Qualitative Filter Paper No. 2) manufactured by ADVANTEC Toyo Co., Ltd. (trade name).

[0168] A: No undissolved matter was visually confirmed to remain. In addition, 100 g of the coating material was able to be filtered without retardation.

[0169] B: No undissolved matter was visually confirmed to remain. However, clogging occurred when filtration was attempted, and the entire amount could not be filtered out.

[0170] C: It was visually confirmed that undissolved matter remained.

[0171] (ii) Storage stability 1

[0172] Each of the above-mentioned coatings (S-1) to (S-4), (S-6) to (S-7) and (S-10) to (S-14) (the coatings with productivity (solubility) of the above-mentioned test (i) coating being A-grade) is allowed to stand for a predetermined period of time at a temperature of 25°C, and then the viscosity is measured using a tuning fork vibration viscometer "SV-10" (trade name) of A&D Co., Ltd., and evaluated according to the following criteria. In a usage mode requiring higher storage stability (for example, when the coating needs to be left at room temperature for more than 3 hours), if the evaluation grade of the storage stability 1 of the coating composed of components (A) and (B) is C or above, the coating can be actually adopted. From the viewpoint of practical adoption, the evaluation grade of the storage stability 1 of the coating is preferably B or above, and A is the best.

[0173] A: After standing for 3 weeks, the viscosity is below 500 mPa·s.

[0174] B: The viscosity after standing for 48 hours was 500 mPa·s or less, but the viscosity after standing for 3 weeks exceeded 500 mPa·s.

[0175] C: The viscosity after standing for 3 hours was 500 mPa·s or less, but the viscosity after standing for 48 hours exceeded 500 mPa·s.

[0176] D: After standing for 3 hours, the viscosity exceeds 500 mPa·s.

[0177] (2) Preparation of coating (T-1)

[0178] Relative to 100 parts by mass of the component (A-1) in the coating (S-1), 9.8 parts by mass of the component (C-1) (6.4 parts by mass in terms of solid content) was mixed and stirred in the coating (S-1) to obtain a coating (T-1). It should be noted that, regarding the component (C-1), the amount of the solid content is recorded in the table.

[0179] The following test (iii) Storage stability 2 was conducted. The results are shown in Table 2.

[0180] Preparation of coatings (T-2) to (T-11)

[0181] In order to prepare the coating as shown in Table 2, coatings (T-2) to (T-11) were obtained in the same manner as the coating (T-1) except that at least one of the type of the coating (S), the type of the component (C) and the amount of the component (C) was changed. The following test (iii) storage stability 2 was performed. The results are shown in Table 2. It should be noted that, for the components (C-1) and (C-2), the amounts of solid content conversion are recorded in the table.

[0182] (iii) Storage stability 2

[0183] After each of the above-mentioned coatings (T-1) to (T-11) was left to stand for a predetermined time in an environment at a temperature of 25°C, the viscosity was measured using a tuning fork vibration viscometer "SV-10" (trade name) of A&D Co., Ltd. and evaluated according to the following criteria. In the use mode requiring higher storage stability (for example, when the coating needs to be left at room temperature for more than 3 hours), if the evaluation grade of storage stability 2 of the coating composed of components (A), (B) and (C) is B or above, then the coating can be actually adopted. From the perspective of practical adoption, the evaluation grade of storage stability 2 of the coating is preferably A.

[0184] A: After standing for 24 hours, the viscosity is below 500 mPa·s.

[0185] B: The viscosity after standing for 3 hours was 500 mPa·s or less, but the viscosity after standing for 24 hours exceeded 500 mPa·s.

[0186] C: After standing for 3 hours, the viscosity exceeds 500 mPa·s.

[0187] (3) Production of flame-retardant polyolefin hot-melt adhesives

[0188] A formulation consisting of 55 parts by mass of maleic anhydride modified polypropylene "FUSABOND P353" (trade name) of Dow Chemical Japan Co., Ltd., 35 parts by mass of ethylene vinyl acetate copolymer "EVAFLEX V523" (trade name) of DUPONT-MITSUIPOLYCHEMICALS Co., Ltd., 10 parts by mass of random polypropylene "F-227D" (trade name) of Primen Polymer Co., Ltd., 54 parts by mass of brominated flame retardant "SAYTEX 8010" (trade name) of Albemarle Japan Co., Ltd., 18 parts by mass of antimony trioxide "PATOX-M" (trade name) of Nippon Seiko Co., Ltd. and 1 part by mass of external lubricant "metablen L100P" (trade name) of Mitsubishi Chemical Corporation was melt-kneaded using a co-rotating twin-screw extruder at a die outlet resin temperature of 210° C. to obtain a flame-retardant polyolefin hot-melt adhesive.

[0189] (4) Film formation of flame-retardant polyolefin hot-melt adhesive

[0190] Using the flame-retardant polyolefin hot-melt adhesive obtained in the above step (3), a film-forming device including a T-die, an extruder and a stretching and winding device with a nip method is used to form an adhesive resin film with a thickness of 40 μm at a resin temperature of 210°C at the steel die outlet.

[0191] Example 1

[0192] The above-mentioned coating (T-1) is applied to the corona discharge treated surface of the above-mentioned substrate film (P-1) by a rod coating method so that the thickness after drying is 1 μm, and dried at a temperature of 100°C to form a coating film. Secondly, the adhesive resin film obtained in the above-mentioned step (4) is overlapped on the surface of the coating film, and a dielectric heating laminating machine is used for heat lamination to obtain a laminate having a substrate film, a coating film and an adhesive resin film (flame-retardant polyolefin hot-melt adhesive layer) in sequence. At this time, the hot lamination conditions are a preheating temperature of 110°C for the pressure roller, a preheating temperature of 110°C for the receiving roller, a pressure of 0.4 MPa and a speed of 1.0 m / min. The following tests (iv) and (v) are carried out. The results are shown in Table 3.

[0193] Examples 2 to 11

[0194] Laminated bodies were obtained in the same manner as in Example 1 except that each of the coating materials (T-2) to (T-11) was used instead of the coating material (T-1). The following tests (iv) and (v) were performed. The results are shown in Table 3.

[0195] Examples 12~15

[0196] A laminate was obtained in the same manner as in Example 1 except that the thickness of the coating film was changed to the thickness (thickness after drying) shown in Table 3. The following tests (iv) and (v) were performed. The results are shown in Table 3.

[0197] Examples 16~18

[0198] A laminate was obtained in the same manner as in Example 1 except that each of the substrate films (P-2) to (P-4) was used instead of the substrate film (P-1). The following tests (iv) and (v) were performed. The results are shown in Table 3.

[0199] Examples 19 and 20

[0200] A laminate was obtained in the same manner as in Example 1 except that the thickness of the coating film was changed to the thickness (thickness after drying) shown in Table 3 and the substrate film (P-2) or (P-3) was used instead of the substrate film (P-1). The following tests (iv) and (v) were performed. The results are shown in Table 3.

[0201] Example 21

[0202] A laminate was obtained in the same manner as in Example 1 except that the coating material (S-1) (containing no curing agent) was used instead of the coating material (T-1) (containing a curing agent). The following tests (iv) and (v) were performed. The results are shown in Table 3.

[0203] (iv) Bonding strength 1 (bonding strength under standard conditions)

[0204] From the above-mentioned laminate, cut out two strips with a width of 50mm and a length of 150mm, and overlap the two strips so that their adhesive resin films (flame retardant polyolefin hot melt adhesive layers) are opposite to each other, and are all preheated to 190°C metal plates and silicone rubber sheets, and pressed under the conditions of pressure 0.3MPa and time 8 seconds to make them heat-weld. After state adjustment for 24 hours under standard conditions (temperature 23°C, relative humidity 50%), under the environment of standard conditions, collect a test piece with a width of 1 inch (25.4mm) and a length of 150mm from the heat-welded strips, and measure the bonding strength under the conditions of test speed 100mm / min and T-shaped peeling (peeling angle 180°). In addition, visually observe the peeling interface to confirm which interface is damaged (destruction mode). The meaning of each symbol in the table is as follows.

[0205] P material broken: The substrate film is damaged.

[0206] HM: The flame-retardant polyolefin hot-melt adhesive layer was cohesively destroyed.

[0207] P / AC: interfacial (interlayer) delamination between substrate film and coating film.

[0208] AC / HM: Delamination of the interface (interlayer) between the coating film and the flame-retardant polyolefin hot-melt adhesive layer.

[0209] The bonding strength 1 (bonding strength under standard conditions) is preferably 10 N / inch or more, more preferably 12 N / inch or more, even more preferably 13 N / inch or more, and even more preferably 15 N / inch or more.

[0210] ">16" in the table means that when the failure mode is P material failure (base film failure), the stress at the time of the base film failure is 16 N / inch or more.

[0211] (v) Adhesion strength 2 (moisture and heat resistant adhesion strength)

[0212] Adhesion strength is measured using a tensile testing machine equipped with a constant temperature and humidity chamber. Specifically, after stabilizing the temperature in the constant temperature and humidity chamber at 105°C and relative humidity of 50%, the test piece obtained in the same manner as in the above-mentioned test (iv) Adhesion Strength 1 is set in a fixture in the constant temperature and humidity chamber, and the temperature of the constant temperature and humidity chamber reaches 105°C again, and after 10 minutes, the adhesion strength is measured under the conditions of a test speed of 100 mm / min and T-peeling (peeling angle of 180°). In addition, the peeling interface is visually observed to confirm which interface is damaged (destruction mode). The meaning of each symbol in the table is the same as that of the above-mentioned test (iv) Adhesion Strength 1.

[0213] The above-mentioned bonding strength 2 (moisture-heat resistant bonding strength) is preferably 1 N / inch or more, more preferably 2 N / inch or more, even more preferably 3 N / inch or more, and even more preferably 4 N / inch or more.

[0214] [Table 1]

[0215] Table 1 Coating preparation and characteristics

[0216]

[0217] [Table 2]

[0218] Table 2 Preparation and properties of coatings containing curing agent

[0219]

[0220] [Table 3]

[0221] Table 3 Composition and properties of laminate

[0222]

[0223] In the above examples, it was confirmed that by using the coating of the present invention, a preferred coating film can be formed as an anchor coating. The preferred coating of the present invention further has good storage stability. In addition, in the above examples, the coating of the present invention can show good bonding strength to any one of the adhesive resin composition layer of the polyolefin resin composition, the polyethylene naphthalate resin film, the polyimide resin film, and the polyphenylene sulfide resin film. The preferred coating of the present invention can further show good bonding strength to any one of the adhesive resin composition layer of the polyolefin resin composition, the polyethylene naphthalate resin film, the polyimide resin film, and the polyphenylene sulfide resin film under a high temperature and high humidity environment. It can be judged from the confirmed results of the above examples that the coating of the present invention can be used as a coating for forming an anchor coating, especially as a coating for forming an anchor coating for improving the interlayer bonding strength between the adhesive resin composition layer of the polyolefin resin composition of the flexible flat cable and the polyethylene naphthalate resin film, etc.

Claims

1. A coating, characterized in that: Include: (A) 100 parts by mass of acid-modified polypropylene; and (B) 550 parts by mass or more of an organic solvent, The melting point of the (A) acid-modified polypropylene is below 90°C; The (B) organic solvent is composed of: (B1) 92 to 99% by mass of an aromatic hydrocarbon solvent; and (B2) 8 to 1% by mass of one or more solvents selected from the group consisting of ester solvents, ketone solvents and alcohol solvents, The sum of the proportion of the aromatic hydrocarbon solvent (B1) and the proportion of the solvent (B2) is 100% by mass; The coating material further comprises (C) 0.1 to 20 parts by mass of a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule.

2. The coating according to claim 1, wherein The compound (C) having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule is a compound having no hydrolyzable group.

3. The coating according to claim 1, wherein The (B2) is at least one selected from the group consisting of an ester solvent, a ketone solvent, and an alcohol solvent, and has a water solubility of 5 g or more, or is water-soluble.

4. The coating according to claim 1 or 2, wherein The acid modification amount of the (A) acid-modified polypropylene is 0.1 to 2.8% by mass.

5. A coating film, characterized in that: The coating material is formed by using the coating material according to any one of claims 1 to 4.

6. The coating film according to claim 5, wherein The thickness is 0.05 μm or more and less than 5 μm.

7. The coating film according to claim 6, characterized in that The coating material is formed by using a coating material containing 70 mass % or more of (A) acid-modified polypropylene as a solid content.

8. The coating film according to claim 7, wherein The coating material containing 70% by mass or more of (A) acid-modified polypropylene as a solid content comprises: (A) 100 parts by mass of acid-modified polypropylene; and (C) 0.1 to 20 parts by mass of a compound having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule.

9. The coating film according to claim 8, wherein The compound (C) having two or more functional groups capable of forming a chemical bond with a carboxyl group in one molecule is a compound having no hydrolyzable group.

10. A laminate, characterized in that: Include: Base film; and The coating film according to any one of claims 5 to 9, which is formed on at least one surface of the substrate film. The coating film is formed directly on the surface of the substrate film.

11. The laminate according to claim 10, wherein The substrate film is a polyethylene naphthalate resin film, a polyimide resin film, or a polyphenylene sulfide resin film.

12. The laminate according to claim 10 or 11, wherein The base film has the coating film and the adhesive resin layer in this order on at least one surface thereof.

13. The laminate according to claim 12, wherein The adhesive resin layer is a polyolefin hot-melt adhesive layer.

14. A flexible flat cable, characterized in that: The invention comprises the laminate according to any one of claims 10 to 13.

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