Copolymer and resin composition comprising the same

Abstract

The present invention provides a copolymer capable of suppressing coloring even after heating. A copolymer containing a structural unit (A) derived from 1, 1-dicyanoethylene and a structural unit (B) derived from a compound represented by general formula (I) CH2 = CR1R2 (I), characterized in that: the copolymer contains the following four types of triad structures (U-1)-(U-4) comprising the structural unit (A) and the structural unit (B); the total content of (U-2) and (U-3) in the total amount of the four triad structures (A)-(A)-(A)... (U-1) (A)-(A)-(B)... (U-2) (B)-(A)-(A)... (U-3) (B)-(A)-(B)... (U-4) is 9.0 mol% or less.

Description

Technical Field

[0001] The present invention relates to a copolymer containing a structural unit derived from 1,1-dicyanoethylene and a structural unit derived from a specific polymerizable monomer in a specific arrangement, and a resin composition containing the copolymer. Background Art

[0002] Films using copolymers obtained by free radical polymerization of 1,1-dicyanoethylene and polymerizable monomers have excellent transparency and are therefore suitable for use in various materials such as optical components, lighting components, sign components, and decorative components (e.g., Patent Document 1). Research on polymers using the above-mentioned 1,1-dicyanoethylene is in vogue, and, for example, Non-Patent Document 1 describes an analysis method for copolymers of 1,1-dicyanoethylene and vinyl acetate.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 01-103614

[0006] Non-patent literature

[0007] Non-patent literature 1: Macromolecules, 1985, 18, 1850-1855 Summary of the invention

[0008] Problems to be solved by the invention

[0009] As described above, a film using a copolymer obtained by radical polymerization of 1,1-dicyanoethylene and a polymerizable monomer has excellent transparency, but there is a problem that when the copolymer is heated, it is colored and the appearance is impaired.

[0010] The present invention has been made in view of the above-mentioned conventional problems, and its subject is to provide a copolymer which can suppress coloration even after heating. In addition, the present invention provides a resin composition containing the copolymer, and a molded product and a film using the copolymer.

[0011] Methods used to solve problems

[0012] The present inventors have conducted research and found that by free radical polymerization of 1,1-dicyanoethylene and a specific polymerizable monomer at a relatively low temperature and at a specific input ratio, the structural units derived from 1,1-dicyanoethylene and the structural units derived from the polymerizable monomer are polymerized in a specific arrangement. Based on this finding, further research was conducted and found that by controlling the arrangement of each monomer, a copolymer capable of suppressing coloration even after heating can be obtained, thereby completing the present invention.

[0013] That is, the present invention provides the following [1] to

[12] .

[0014] [1] A copolymer comprising a structural unit (A) derived from 1,1-dicyanoethylene and a structural unit (B) derived from a compound represented by the following general formula (I),

[0015] CH2=CR 1 R 2 (I)

[0016] It is characterized in that

[0017] The copolymer contains the following four triad structures (U-1) to (U-4) composed of the structural unit (A) and the structural unit (B),

[0018] (A)-(A)-(A) … (U-1)

[0019] (A)-(A)-(B) … (U-2)

[0020] (B)-(A)-(A) … (U-3)

[0021] (B)-(A)-(B) … (U-4)

[0022] The total content of (U-2) and (U-3) in the total amount of the above four types of triad structures is 9.0 mol % or less.

[0023] (In the general formula (I), R 1 is one or more selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group and a halogen atom,

[0024] R 2 is selected from alkoxy, carboxyl, -COOR 3 (R 3 is an alkyl group having 1 to 12 carbon atoms), an ester group, an acid anhydride group, a -COR 4 (R 4 is an alkyl group having 1 to 12 carbon atoms), an acyl group represented by -OCOR 5 (R 5 is an alkyl group having 1 to 12 carbon atoms).

[0025] [2] The copolymer according to [1] above, wherein the content of the (U-1) is 1.8 mol % or less in the total amount of the four triad structures.

[0026] [3] The copolymer according to [1] or [2] above, wherein the content of the structural unit (A) in the total amount of the copolymer is 30 to 55 mol %.

[0027] [4] The copolymer according to any one of [1] to [3] above, wherein the compound represented by the general formula (I) is one or more selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, methyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate.

[0028] [5] A resin composition comprising the copolymer according to any one of [1] to [4] above.

[0029] [6] A molded product using the copolymer described in any one of [1] to [4] or the resin composition described in [5] above.

[0030] [7] A film using the copolymer described in any one of [1] to [4] or the resin composition described in [5], wherein the difference between the yellowness before heating and the yellowness after heating at 140° C. for 1 hour under normal pressure is 3.0% or less.

[0031] [8] A conductive film comprising a conductive layer stacked on the film according to [7].

[0032] [9] A thin film capacitor comprising the thin film described in [7] above or the conductive thin film described in [8] above.

[0033]

[10] A polarizing material comprising the resin composition described in [5] above or the film described in [7] above.

[0034]

[11] An electrostatic induction conversion element comprising the polarizing material described in

[10] above.

[0035]

[12] A touch panel comprising the electrostatic induction conversion element described in

[11] above.

[0036] Effects of the Invention

[0037] According to the present invention, a copolymer capable of suppressing coloration even after heating can be provided. In addition, according to the present invention, a resin composition containing the copolymer, and a molded product and a film using the copolymer can be provided. DETAILED DESCRIPTION

[0038] [Copolymer]

[0039] The copolymer of the present invention is a copolymer containing a structural unit (A) derived from 1,1-dicyanoethylene and a structural unit (B) derived from a compound represented by the following general formula (I).

[0040] CH2=CR 1 R 2 (I)

[0041] It is characterized in that

[0042] The copolymer contains the following four triad structures (U-1) to (U-4) composed of the structural unit (A) and the structural unit (B),

[0043] (A)-(A)-(A) … (U-1)

[0044] (A)-(A)-(B) … (U-2)

[0045] (B)-(A)-(A) … (U-3)

[0046] (B)-(A)-(B) … (U-4)

[0047] The total content of (U-2) and (U-3) in the total amount of the above four types of triad structures is 9.0 mol % or less.

[0048] (In the general formula (I), R 1 is one or more selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group and a halogen atom,

[0049] R 2 is selected from alkoxy, carboxyl, -COOR 3 (R 3 is an alkyl group having 1 to 12 carbon atoms), an ester group, an acid anhydride group, a -COR 4 (R 4 is an alkyl group having 1 to 12 carbon atoms), an acyl group represented by -OCOR 5 (R 5 is an alkyl group having 1 to 12 carbon atoms).

[0050] In the present invention, the "triad structure" refers to a structure in which three structural units (A) derived from 1,1-dicyanoethylene and three structural units (B) derived from the compound represented by the above general formula (I) are connected.

[0051] In addition, "(A)-(A)-(A)", which is one of the above-mentioned four triad structures, refers to a triad structure in which three structural units (A) derived from 1,1-dicyanoethylene are continuously bonded, and "(A)-(A)-(B)" refers to a triad structure in which two structural units (A) derived from 1,1-dicyanoethylene are continuously bonded and then bonded to a structural unit (B) derived from the compound represented by the above-mentioned general formula (I), and the other triad structures have the same meaning.

[0052] In the present invention, the amounts of four triad structures (U-1) to (U-4) are specified. The amount of the triad structure (U-1) refers to "the content (mol %) of (A) bonded between two (A)s in the structure of (A)-(A)-(A) constituting (U-1)". Similarly, the content of the triad structure (U-2) refers to "the content (mol %) of (A) bonded between (A) and (B) in the structure of (A)-(A)-(B) constituting (U-2)". The contents of other triad structures have the same meaning.

[0053] It should be noted that the contents of the triad structures (U-1) to (U-4) in the present invention can be adjusted by 13 C-NMR can be measured, and specifically, it can be measured by the method described in the Examples.

[0054] The present invention is characterized in that the total content of (U-2) and (U-3) in the total amount of the above-mentioned four triad structures is 9.0 mol% or less. When the total content of the above-mentioned (U-2) and (U-3) is 9.0 mol% or less, the amount of the arrangement that causes coloration due to heat, specifically the continuous arrangement of (A), can be suppressed to a small extent, so that the molded product using the copolymer of the present invention can suppress coloration even after heating.

[0055] From the viewpoint of effectively suppressing coloration, the total content of (U-2) and (U-3) in the total amount of the above-mentioned four triad structures is 9.0 mol% or less, preferably 8.5 mol% or less, preferably 8.0 mol% or less, preferably 7.5 mol% or less, preferably 7.0 mol% or less, preferably 6.0 mol% or less, and further preferably 5.0 mol% or less. Usually, the lower limit is 0.5 mol% or more, but it may be less than that.

[0056] The total content of (U-2) and (U-3) can be adjusted by controlling the amount of monomers added at a relatively low temperature of less than 50°C.

[0057] In addition, in the present invention, the content of the above-mentioned (U-1) in the total amount of the above-mentioned 4 triad structures is preferably 1.8 mol% or less. When the content of the above-mentioned (U-1) is below the above-mentioned upper limit value, the continuous arrangement of (A) in the copolymer becomes less, and therefore, as a result, the coloring after heating of the molded product using the copolymer of the present invention can be further suppressed. From the above viewpoint, the content of the above-mentioned (U-1) in the total amount of the above-mentioned 4 triad structures is preferably 1.4 mol% or less, more preferably 1.0 mol% or less, further preferably 0.6 mol% or less, further preferably 0.4 mol% or less, and particularly preferably 0.3 mol% or less.

[0058] <Structural unit derived from 1,1-dicyanoethylene (A)>

[0059] The copolymer of the present invention contains a structural unit (A) derived from 1,1-dicyanoethylene. Since 1,1-dicyanoethylene provides a highly transparent copolymer by radical polymerization, the copolymer of the present invention can be suitably used for molded products and the like that require transparency.

[0060] 1,1-Dicyanoethylene can be produced by the production methods described in J. Am. Chem. Soc., 1989, 111, 9078-9081 and US Patent Application Publication No. 2476270.

[0061] <Structural unit (B) derived from the compound represented by general formula (I)>

[0062] The copolymer of the present invention contains a structural unit (B) derived from a compound represented by the following general formula (I).

[0063] CH2=CR 1 R 2 (I)

[0064] (In the general formula (I), R 1 is one or more selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group and a halogen atom,

[0065] R 2 is selected from alkoxy, carboxyl, -COOR 3 (R 3 is an alkyl group having 1 to 12 carbon atoms), an ester group, an acid anhydride group, a -COR 4 (R 4 is an alkyl group having 1 to 12 carbon atoms), an acyl group represented by -OCOR 5 (R 5 is an alkyl group having 1 to 12 carbon atoms).

[0066] In the general formula (I), R1 is at least one selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group and a halogen atom.

[0067] As R 1 The alkyl group is preferably an alkyl group having 1 to 12 carbon atoms, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, heptyl, octyl, decyl and dodecyl.

[0068] As R 1 The cycloalkyl group is preferably a cycloalkyl group having 3 to 12 carbon atoms, and examples thereof include cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

[0069] As R 1 The aryl group is preferably an aryl group having 6 to 20 carbon atoms, and examples thereof include phenyl, tolyl, xylyl and naphthyl.

[0070] As R 1 The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms, and examples thereof include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy and tert-butoxy.

[0071] As R 1 The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0072] However, from the viewpoint of suppressing the coloration of the molded product using the copolymer of the present invention after heating, R 1 A hydrogen atom and an alkyl group having 1 to 6 carbon atoms are preferred, a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are more preferred, and a hydrogen atom and a methyl group are further preferred.

[0073] In the general formula (I), R 2 is selected from alkoxy, carboxyl, -COOR 3 (R 3 is an alkyl group having 1 to 12 carbon atoms), an ester group, an acid anhydride group, a -COR 4 (R 4 is an alkyl group having 1 to 12 carbon atoms), an acyl group represented by -OCOR 5 (R 5 is an alkyl group having 1 to 12 carbon atoms).

[0074] As R 2 The alkoxy group is preferably an alkoxy group having 1 to 12 carbon atoms, and examples thereof include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy and tert-butoxy.

[0075] R2 Can be made by -COOR 3 The ester group represented by R 3 Examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, heptyl, octyl, decyl and dodecyl.

[0076] As R 2 Examples of the acid anhydride groups include those derived from phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, glutaric anhydride, dimethylglutaric anhydride, diethylglutaric anhydride, succinic anhydride, methylhexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride.

[0077] R 2 Can be made by -COR 4 The acyl group represented by R 4 Examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl and n-hexyl.

[0078] R 2 Can be by-OCOR 5 The acyloxy group represented by R 5 Examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl and n-hexyl.

[0079] However, from the viewpoint of suppressing the coloration of the molded product using the copolymer of the present invention after heating, R 2 Preferably, it is selected from -COOR 3 The ester group represented by -OCOR 5 One or more of the group consisting of acyloxy groups represented by -COOR 3 The ester group represented by 3 is an alkyl group having 1 to 12 carbon atoms), represented by -OCOR 5 The acyloxy group represented by 5 is an alkyl group having 1 to 6 carbon atoms), more preferably -COOR 3 The ester group represented by 3 is an alkyl group having 1 to 12 carbon atoms), represented by -OCOR 5 The acyloxy group represented by 5 is an alkyl group having 1 to 4 carbon atoms).

[0080] More specifically, from the viewpoint of suppressing coloration, the compound represented by the general formula (I) is preferably one or more selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, methyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate, and more preferably one or more selected from the group consisting of vinyl acetate, methyl methacrylate, methyl acrylate and ethyl acrylate. By using these compounds, discoloration can be more effectively suppressed.

[0081] The compound represented by the above general formula (I) can be easily obtained from commercial products, or can be produced by a known method.

[0082] <Content of each structural unit in the copolymer>

[0083] The content of the structural unit (A) in the copolymer of the present invention is preferably 30 to 55 mol %, more preferably 40 to 53 mol %, and even more preferably 45 to 53 mol %.

[0084] On the other hand, the content of the structural unit (B) is preferably 20 to 80 mol %, preferably 45 to 70 mol %, more preferably 47 to 60 mol %, and further preferably 47 to 55 mol %.

[0085] When the content of each structural unit is within the above range, a molded product using the copolymer of the present invention is unlikely to be colored even after heating.

[0086] It should be noted that the content of the above-mentioned structural units can be 1 H-NMR can be measured, and specifically, it can be measured by the method described in Examples.

[0087] <Other structural units>

[0088] The copolymer of the present invention may also contain structural units derived from other monomers in addition to the structural unit (A) derived from 1,1-dicyanoethylene and the structural unit (B) derived from the compound represented by the above general formula (I). The other structural units are not particularly limited, and examples thereof include aromatic vinyl compounds such as styrene, α-methylstyrene and tert-butylstyrene.

[0089] When the copolymer of the present invention contains a structural unit derived from other monomers, the content of the structural unit in the copolymer is preferably 20 mol % or less, more preferably 10 mol % or less, and even more preferably 5 mol % or less.

[0090] [Method for producing copolymer]

[0091] The method for producing the copolymer of the present invention is not particularly limited, but it is preferably produced at a polymerization temperature of less than 50° C. in the presence of a radical initiator.

[0092] By making the polymerization temperature lower than 50° C., it is easy to adjust the content of (U-2) and (U-3) in the total amount of the above four triad structures to 9.0 mol % or less. From the viewpoint of adjusting the content of (U-2) and (U-3), the polymerization temperature is preferably 47° C. or less, and more preferably 45° C. or less.

[0093] From the viewpoint of polymerization rate and productivity, the polymerization temperature is preferably 10° C. or higher, more preferably 20° C. or higher, and even more preferably 30° C. or higher.

[0094] <Radical polymerization initiator>

[0095] In the production of the copolymer of the present invention, it is preferred to produce it in the presence of a radical polymerization initiator. By using a radical polymerization initiator, it is easy to adjust the total content of (U-2) and (U-3) in the total amount of the triad structure.

[0096] As the free radical polymerization initiator that can be used in the present invention, for example, there can be mentioned: azo compounds such as azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate; inorganic peroxides such as sodium persulfate, potassium persulfate, hydrogen peroxide; organic peroxides such as tert-butyl hydroperoxide, cumene hydroperoxide, and p-menthane hydroperoxide; redox initiators composed of a combination of an oxidant and a reductant such as hydrogen peroxide and an iron (II) salt, a persulfate and sodium bisulfite, etc. These can be used alone or in combination of two or more.

[0097] As described above, the copolymer of the present invention can be easily adjusted in the total content of (U-2) and (U-3) in the total amount of the triad structure by free radical polymerization at low temperature. Therefore, among these free radical polymerization initiators, azo compounds such as azobisisobutyronitrile and 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), redox initiators, etc., which are easy to use at low temperatures, are preferred.

[0098] The amount of the radical polymerization initiator used is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, and even more preferably 0.08 to 3 parts by mass, based on 100 parts by mass of all monomers used as raw materials of the copolymer.

[0099] <Ratio of input amount when producing copolymer>

[0100] In the production of the copolymer of the present invention, the amount of the compound represented by the general formula (I) is preferably 1.5 equivalents or more, more preferably 1.8 equivalents or more, and further preferably 2.2 equivalents or more relative to the amount of 1,1-dicyanoethylene. Generally, from the viewpoint of suppressing the production cost, it is preferably 5.0 equivalents or less. When the amount of the compound represented by the general formula (I) relative to the amount of 1,1-dicyanoethylene is greater than the lower limit, it is easy to adjust the total content of (U-2) and (U-3) in the total amount of the triad structure, and as a result, it is possible to suppress the discoloration of the molded product using the copolymer after heating.

[0101] In the production of the copolymer of the present invention, from the viewpoint of suppressing ionic polymerization, it is preferred that the amount of water contained in 1,1-dicyanoethylene is low. The amount of water contained in 1,1-dicyanoethylene is preferably 10000 ppm or less, more preferably 1000 ppm or less, further preferably 500 ppm or less, and further preferably 300 ppm or less. When the amount of water contained in 1,1-dicyanoethylene is below the above upper limit, it is easy to adjust the total content of (U-2) and (U-3) in the total amount of the above triad structure, and as a result, it is possible to suppress discoloration of a molded product using the copolymer after heating.

[0102] The amount of water contained in 1,1-dicyanoethylene can be measured by a method in accordance with JIS K0068:2001, for example.

[0103] [Resin composition]

[0104] The resin composition of the present invention contains the above copolymer and can be suitably used as a raw material for molded products, etc. As described above, the copolymer of the present invention can suppress coloration even after heating and is therefore particularly suitable as a material for films, etc.

[0105] The resin composition of the present invention is not particularly limited as long as it contains the above-mentioned copolymer, and may contain a synthetic resin in addition to the above-mentioned copolymer.

[0106] Other synthetic resins include polyethylene, polypropylene, copolymers of ethylene and one or more α-olefins having 3 to 20 carbon atoms (e.g., propylene, 1-butene, 1-pentene, 1-hexene, etc.), ethylene-propylene-diene copolymers (EPDM), ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers and other polyolefin resins, polyurethane resins, polyamide resins, polyester resins and polycarbonate resins.

[0107] Furthermore, the resin composition of the present invention may contain other components as necessary in addition to the copolymer of the present invention and the above-mentioned synthetic resin.

[0108] As other components, a solvent, a filler, a thickener, an anti-aging agent, a plasticizer, a flame retardant, a stabilizer, an antioxidant and the like may be contained.

[0109] From the viewpoint of suppressing coloration, the content of the copolymer in the resin composition of the present invention is preferably 0.1% by mass or more, more preferably 20% by mass or more, and even more preferably 50% by mass or more.

[0110] On the other hand, when resin combination of the present invention contains optional component, i.e., above-mentioned synthetic resin and other components, their total content is preferably below 99.9 mass %, more preferably below 80 mass %, further preferably below 50 mass %, usually preferably above 1 mass %. The content of above-mentioned other components is preferably below 10 mass %, more preferably below 3 mass %, usually preferably above 0.001 mass %.

[0111] <Method for producing resin composition>

[0112] The resin composition can be prepared by a method including a mixing step of mixing the copolymer of the present invention with the synthetic resin and other components as required. The method of mixing the components is not particularly limited and can be mixed by a known method.

[0113] [Molded products and films]

[0114] The molded product and film of the present invention use the copolymer or resin composition of the present invention. As the shape of the molded product, there is no restriction as long as it is a shape that can be manufactured using the copolymer or resin composition of the present invention, and various shapes such as films, pellets, sheets, plates, pipes, tubes, fibers, nonwoven fabrics, rods, and granules can be cited.

[0115] The method for producing the molded product is not particularly limited, and the molded product can be molded by various conventionally known molding methods, such as injection molding, blow molding, press molding, extrusion molding, and calendar molding.

[0116] Examples of molded products using the copolymer composition of the present invention include thin film capacitors, insulating layers of EL elements, electrostatic induction conversion elements, sensors (e.g., touch sensors, vibration sensors, biosensors, tire sensors (sensors provided on the inner surface of a tire)), actuators, touch panels, tactile devices (devices having the function of providing tactile feedback to a user), vibration power generation devices (e.g., vibration power generation floors, vibration power generation tires), speakers, microphones, and the like.

[0117] The molded product of the present invention is preferably a film. As described above, the molded product using the copolymer of the present invention can suppress coloring even after heating, so by processing into a film, a film with better appearance can be obtained.

[0118] The film of the present invention can suppress coloration even after heating, so the difference in yellowness before heating and after heating at 140° C. for 1 hour under normal pressure is preferably 3.0% or less, more preferably 2.0% or less, further preferably 1.0% or less, and more preferably 0.9% or less.

[0119] It should be noted that the film of the present invention can also suppress the yellowness to a low level before heating. Specifically, the yellowness is preferably 1.5% or less, and more preferably 1.2% or less.

[0120] The film of the present invention preferably has a low yellowness after heating, and the yellowness after heating at 140° C. for 1 hour under normal pressure is preferably 3.0% or less, more preferably 2.5% or less, further preferably 2.0% or less, and further preferably 1.8% or less.

[0121] The yellowness in the present invention is the yellowness measured in accordance with JIS Z8722:2009, and can be specifically measured by the method described in the Examples.

[0122] The thickness of the film of the present invention is not particularly limited, but is preferably 0.001 to 5.0 mm, more preferably 0.005 to 1.5 mm, further preferably 0.01 to 1.0 mm, further preferably 0.01 to 0.5 mm, further preferably 0.01 to 0.1 mm from the viewpoint of improving the transparency of the film.

[0123] The film of the present invention may be produced by any method known in the art, such as solution casting, melt extrusion, calendaring, compression molding, and injection molding.

[0124] [Conductive films, film capacitors]

[0125] In the conductive film of the present invention, a conductive layer is stacked on the above-mentioned film, and the film capacitor of the present invention includes the above-mentioned film or the above-mentioned conductive film.

[0126] The conductive film of the present invention uses the thin film of the present invention having an excellent relative dielectric constant, and therefore exhibits excellent performance as a film capacitor.

[0127] The conductive layer constituting the conductive film is not particularly limited, and is usually preferably a layer composed of a conductive metal such as aluminum, zinc, gold, platinum and copper, and is a metal foil or a metal coating (such as a vapor-deposited metal coating), and a combination of the two may be used. Among these, vapor-deposited metal coatings are preferred from the viewpoints of thinning the conductive layer and increasing the capacity relative to the volume, improving the adhesion with the dielectric, and reducing the unevenness of the thickness.

[0128] The vapor-deposited metal film may be formed into a multilayer structure by further forming a semiconductor aluminum oxide layer on an aluminum layer for the purpose of imparting moisture resistance, as described in Japanese Patent Application Laid-Open No. 2-250306, for example.

[0129] The thickness of the vapor-deposited metal film is not particularly limited, but is preferably 10 to 200 nm, more preferably 20 to 100 nm. When the thickness of the vapor-deposited metal film is within the above range, both the capacitance and the strength of the capacitor can be achieved, which is preferred.

[0130] When a deposited metal film is used as the conductive layer, the method for forming the film is not particularly limited, and for example, vacuum deposition, sputtering, ion plating, etc. may be used, and generally, vacuum deposition is preferred.

[0131] As the formation method of the conductive layer, for example, a batch method suitable for formed products, a semi-continuous method suitable for long strip products, and a continuous (air to air) method can be listed, and the semi-continuous method as the mainstream is preferred. The metal vapor deposition method of the semi-continuous method is a method as follows: metal vapor deposition is performed in a vacuum system, winding is performed, and then the vacuum system is restored to an atmospheric system, and the vapor-deposited film is taken out.

[0132] [Polarized Materials]

[0133] The polarizing material of the present invention comprises the resin composition of the present invention or the film of the present invention.

[0134] The polarized material of the present invention can be obtained, for example, by subjecting the film of the present invention to a polarization treatment (poling treatment). As the polarization treatment, the following method can be cited: heating the heat-treated molded product to a specified temperature, applying a DC high electric field or a DC high electric field superimposed with an AC electric field from the inside and outside of the molded product for a certain period of time in this state, and then slowly cooling or rapidly cooling. In addition, the following method can also be cited: while performing the above-mentioned heat treatment, applying a DC high electric field or a DC high electric field superimposed with an AC electric field from the inside and outside of the molded product for a certain period of time, and then slowly cooling or rapidly cooling.

[0135] The treatment temperature of the polarization treatment is preferably carried out at a temperature 30°C or higher than the glass transition temperature (Tg) of the heat-treated molded article. The polarization treatment is usually preferably carried out using a metal foil, a metal plate, a conductive paste, a metal coating formed by vacuum evaporation or chemical plating, which is closely attached to both sides of the molded article as an electrode. The applied voltage is usually 10KV / cm or more, preferably with an electric field strength to the extent that no insulation breakdown occurs, more preferably 100 to 1500KV / cm. The treatment time is not particularly limited, and for the heat-treated molded article, it is preferably 1 minute to 5 hours, more preferably 10 minutes to 2 hours.

[0136] Polarization treatment may also be performed by corona discharge treatment. Corona discharge may be either negative corona or positive corona, but negative corona is preferably used from the viewpoint of easy polarization of the non-polarized film.

[0137] The corona discharge treatment is not particularly limited, and examples thereof include a method of applying the corona discharge to a non-polar thin film using a linear electrode, a method of applying the corona discharge to a non-polar thin film using a needle electrode, or a method of applying the corona discharge to a non-polar thin film using a grid electrode as described in Japanese Patent Application Laid-Open No. 2011-181748.

[0138] The conditions for the corona discharge treatment can be appropriately set based on common knowledge in the technical field. If the conditions for the corona discharge treatment are too weak, the piezoelectricity of the obtained film may be insufficient, while if the conditions for the corona discharge treatment are too strong, the obtained film may have point defects.

[0139] In order to suppress the piezoelectric constant d of the obtained polarized film 33 In order to prevent in-plane unevenness, it is preferred that the distance between each needle-shaped electrode and / or linear electrode and the film is constant, that is, the distance between the electrode and the film has no in-plane unevenness (or is extremely small). Specifically, the difference between the longest distance and the shortest distance is preferably within 6 mm, more preferably within 4 mm, and even more preferably within 3 mm.

[0140] In addition, for example, when continuously applying in a roll-to-roll manner, it is preferred that the film be brought into close contact with the roll appropriately and uniformly so that a constant tension is applied to the film. For example, when continuously applying in a roll-to-roll manner using a linear electrode, the DC electric field is preferably -10 to -25 kV, and the processing speed is preferably 10 to 1200 cm / min, although it also varies depending on the distance between the linear electrode and the non-polarized film, the film thickness, etc.

[0141] Regarding polarization treatment, in addition to corona discharge, for example, a method of applying it from both sides of a non-polarized film by clamping it with flat electrodes can also be listed. In this case, it is preferred to use a DC electric field preferably in the range of 0 to 400 MV / m, more preferably 50 to 400 MV / m, with an application time in the range of 0.1 seconds to 60 minutes.

[0142] [Electrostatic induction conversion element, touch panel]

[0143] The electrostatic induction conversion element of the present invention includes the polarizing material of the present invention, and the touch panel of the present invention includes the electrostatic induction conversion element of the present invention.

[0144] The electrostatic induction conversion element can be assembled in a touch panel and also in a vibration generator, an actuator, a sensor, etc. The electrostatic induction conversion element and the touch panel of the present invention are derived from the resin composition or film of the present invention and are particularly useful in terms of durability when used outdoors.

[0145] Example

[0146] Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples.

[0147] In addition, the water content in 1,1-dicyanoethylene in Examples and Comparative Examples was measured by a method in accordance with JIS K0068:2001.

[0148] <Example 1>

[0149] Into a 100-ml four-necked flask equipped with a stirring device, a Dimroth condenser and a thermometer, 2.0 g (0.026 mol, water content 390 ppm) of 1,1-dicyanoethylene synthesized by the method described in the above-mentioned document, 5.5 g of vinyl acetate (0.064 mol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 25 ml of ethyl acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 18 mg of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) were added, and the mixture was heated and stirred at 45°C for 6 hours under a nitrogen flow to carry out free radical polymerization.

[0150] After the polymerization, the precipitated copolymer was filtered, washed with ethyl acetate and n-hexane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in that order, and then dried at 80°C overnight under reduced pressure. The yield of the product (copolymer powder) was 3.4 g, with a yield of 82%.

[0151] The obtained copolymer was subjected to spectrum measurement by NMR by the method described later. The results are shown in Table 1.

[0152] The obtained copolymer was dissolved in N,N-dimethylacetamide (manufactured by Tokyo Chemical Industry Co., Ltd.), applied by solution casting using an applicator (manufactured by Tester Industry Co., Ltd.) to a thickness of 50 μm, and vacuum dried at 40° C. and 1 kPa for 7 days to prepare a film before heating.

[0153] The yellowness of the obtained film was measured by the method described below. The results are shown in Table 1.

[0154] The relative dielectric constant of the obtained thin film was further measured by the method described below. The results are shown in Table 1.

[0155] As shown in Table 1, the film of the present invention can suppress yellowness to a low level and has a high relative dielectric constant. Such a material with a high relative dielectric constant is suitable for use in film capacitors as described in Japanese Patent Application Laid-Open No. 2008-034189.

[0156] Furthermore, the obtained thin film was subjected to polarization treatment, and the piezoelectricity was evaluated by the method described later.

[0157] As shown in Table 3, the film of the present invention can suppress yellowness to a low level and has excellent piezoelectric properties. Therefore, it is suitable as a transparent piezoelectric film for applications requiring transparency such as touch panel applications.

[0158] <Examples 2, 3, 5 to 7, Comparative Examples 1 and 2>

[0159] A film was prepared in the same manner as in Example 1 except that a copolymer was produced according to the ratio of the charged amounts and the polymerization temperature described in Table 1.

[0160] The spectrum of the obtained copolymer was measured by NMR in the same manner as in Example 1, and the yellowness of the obtained film was measured.

[0161] <Example 4>

[0162] Into a 100-ml four-necked flask equipped with a stirring device, a serpentine condenser and a thermometer, 2.0 g (0.026 mol, water content 390 ppm) of 1,1-dicyanoethylene synthesized by the method described in the aforementioned literature, 6.4 g of methyl methacrylate (0.064 mol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 25 ml of toluene (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 18 mg of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) were added, and the mixture was heated and stirred at 40°C for 6 hours under a nitrogen flow to carry out free radical polymerization.

[0163] After the polymerization, the precipitated copolymer was filtered, washed with toluene and n-hexane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) in that order, and then dried at 80° C. under reduced pressure overnight to obtain a product (copolymer powder).

[0164] The obtained copolymer was subjected to NMR spectrum measurement by the method described below. In addition, a thin film was prepared for the obtained copolymer in the same manner as in Example 1, and the yellowness was measured. The results are shown in Table 1.

[0165] <Comparative Example 3>

[0166] A film was prepared in the same manner as in Example 4 except that a copolymer was produced according to the polymerization temperature and the ratio of the charged amounts described in Table 1.

[0167] The spectrum of the obtained copolymer was measured by NMR in the same manner as in Example 1, and the yellowness of the obtained film was measured.

[0168] <Comparative Example 4>

[0169] A film was produced in the same manner as in Example 1 except that the water concentration in 1,1-dicyanoethylene, the polymerization temperature, the ratio of the charged amounts, and the like were changed as described in Table 1.

[0170] The spectrum of the obtained copolymer was measured by NMR in the same manner as in Example 1, and the yellowness of the obtained film was measured.

[0171] <Measurement method>

[0172] (1) Spectral measurement of copolymers by NMR

[0173] The product (copolymer powder) was measured using a nuclear magnetic resonance spectrometer (NMR) under the following conditions: 1 H-NMR and 13 C-NMR spectrum. Using the measurement results, the ratio of each triad structure was determined according to the method described in Non-Patent Document 1. The results are shown in Tables 1 and 2.

[0174] [ 1 H-NMR measurement conditions]

[0175] Device: JEOL Ltd. JNM-ECX400

[0176] Determination solvent: deuterated dimethyl sulfoxide

[0177] Measuring temperature: 65℃

[0178] Chemical shift value standard: tetramethylsilane

[0179] [ 13 C-NMR measurement conditions]

[0180] Device: JEOL Ltd. JNM-ECX400

[0181] Determination solvent: deuterated dimethyl sulfoxide

[0182] Measuring temperature: 65℃

[0183] Determination method: Proton decoupling method

[0184] Pulse width: 45 degrees

[0185] Pulse repetition time: 10 seconds

[0186] Chemical shift value standard: tetramethylsilane

[0187] (2) Determination of yellowness of film

[0188] The films obtained in Examples and Comparative Examples were heated in a clean oven DE-41 (manufactured by Yamato Scientific Co., Ltd.) at 140° C. under normal pressure for 1 hour.

[0189] The yellowness of the film before and after heating was measured using a haze meter SH7000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.) in accordance with JIS Z8722:2009.

[0190] In addition, about yellowness, the value of 3 places of each film was measured, and the average value was adopted as yellowness.

[0191] (3) Determination of relative dielectric constant of thin films

[0192] After the thin films obtained in the examples and comparative examples were humidified at 26°C and 60% RH, Au-Pd alloy with a diameter of 30 mm was vapor-deposited on the surface of the film until the surface was conductive, and vapor deposition was also performed on the opposite side to form a conductive layer to prepare a thin film capacitor sample.

[0193] The electrostatic capacitance (C) of the sample was measured using an LCR meter (manufactured by Keysight), and the relative dielectric constant was calculated using the formula C=ε×ε0×S / d (ε0 is the dielectric constant of vacuum) based on the electrostatic capacitance, electrode area (S), and film thickness (d). The results are shown in Tables 1 and 2.

[0194] (4) Evaluation of piezoelectricity

[0195] Both surfaces of the thin films obtained in Examples and Comparative Examples were subjected to polarization treatment at 160° C. using vacuum-deposited gold electrodes, and the piezoelectric properties of the obtained optical materials were evaluated.

[0196] The piezoelectricity was evaluated as follows: a buffer (metal weight) was placed on the optical material, and a 6.5 g weight was dropped from a height of 20 cm to apply a certain force. The optical material with a voltage of 1 V or more was considered to have "acceptable" piezoelectricity. The results are shown in Table 3.

[0197] [Table 1]

[0198]

[0199] [Table 2]

[0200]

[0201] The results in Tables 1 and 2 show that the copolymer of the present invention can suppress coloring even after heating and can therefore be suitably used for molded products such as films.

[0202] [Table 3]

[0203]

[0204] The results in Table 3 show that the film of the present invention has piezoelectricity and can therefore be suitably used in touch panel applications and the like.

Claims

1. A copolymer comprising a structural unit (A) derived from 1,1-dicyanoethylene and a structural unit (B) derived from a compound represented by the following general formula (I), CH2=CR 1 R 2 (I) It is characterized in that The copolymer contains the following four triad structures (U-1) to (U-4) composed of the structural unit (A) and the structural unit (B), (A)-(A)-(A) … (U-1) (A)-(A)-(B) … (U-2) (B)-(A)-(A) … (U-3) (B)-(A)-(B) … (U-4) The total content of (U-2) and (U-3) in the total amount of the four triad structures is 9.0 mol % or less, In the general formula (I), R 1 is one or more selected from the group consisting of a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group and a halogen atom, R 2 is selected from alkoxy, carboxyl, -COOR 3 Ester group, anhydride group, -COR 4 Acyl represented by -OCOR 5 One or more acyloxy groups represented by 3 is an alkyl group having 1 to 12 carbon atoms, R 4 is an alkyl group having 1 to 12 carbon atoms, R 5 It is an alkyl group having 1 to 12 carbon atoms.

2. The copolymer according to claim 1, wherein The content of (U-1) in the total amount of the four triad structures is 1.8 mol % or less.

3. The copolymer according to claim 1 or 2, wherein The content of the structural unit (A) in the total amount of the copolymer is 30 to 55 mol %.

4. The copolymer according to any one of claims 1 to 3, wherein The compound represented by the general formula (I) is at least one selected from the group consisting of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, methyl methacrylate, methyl acrylate, ethyl acrylate and butyl acrylate. 5 . A resin composition comprising the copolymer according to claim 1 . 6 . A molded product using the copolymer according to claim 1 or the resin composition according to claim 5 .

7. A film comprising the copolymer according to any one of claims 1 to 4 or the resin composition according to claim 5, wherein: The difference between the yellowness before heating and the yellowness after heating at 140° C. under normal pressure for 1 hour was 3.0% or less.

8. A conductive film, wherein: A conductive layer is laminated on the thin film according to claim 7. 9 . A thin film capacitor comprising the thin film according to claim 7 or the conductive thin film according to claim 8 . 10 . A polarizing material comprising the resin composition according to claim 5 or the film according to claim 7 . 11 . An electrostatic induction conversion element comprising the polarizing material according to claim 10 . 12 . A touch panel comprising the electrostatic induction conversion element according to claim 11 .

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