Resin composition and laminate

Abstract

To provide a resin composition for producing a resin sheet constituting a flexible device which enables production of the resin sheet without performing curing reaction, and a laminate having the resin sheet.SOLUTION: A resin composition has a group represented by the following general formula (11), (21) or (31), a urethane bond and a siloxane bond as resin components, in which a contact angle to water of a resin sheet for test, which is obtained by solidifying the resin composition by drying, is 77-116°. A laminate has a resin sheet obtained by solidifying the resin composition by drying.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition and a laminate. [Background technology]

[0002] In recent years, with the development of flexible sensors, wearable devices capable of managing physical condition have been attracting attention. Wearable devices are expected to be used in a wide range of applications in the fields of sports science and healthcare, such as those embedded in clothing or attached directly to the skin, to measure and monitor specific body parts. Because human skin expands and contracts repeatedly on a daily basis, if a wearable device is required to be worn without stress, it is desirable for the device to have stretchability corresponding to the object being worn. Furthermore, it is desirable for wearable devices to have a certain level of strength to withstand stresses generated when bending or rolling, taking into account handling and human movement. In this specification, devices with such characteristics are referred to as stretchable devices, regardless of their intended use.

[0003] Stretchable devices are expected to include electrodes, devices, electronic components, thin-film sensors, and the like within a stretchable element, and their quality must be maintained even in environments where they are repeatedly stretched and contracted. However, it is difficult to realize such stretchable devices using polyimide sheets, which are used in conventional thin-film resin substrates. For these reasons, it is expected that the element and electrodes of stretchable devices will be primarily made of resins that are suitable for stretchability, such as urethane resin, silicone resin, acrylic resin, epoxy resin, polycarbonate, polystyrene, or polyolefin. In particular, a stretchable film that is a cured product of a composition containing a (meth)acrylate compound having a siloxane bond, a (meth)acrylate compound other than the (meth)acrylate compound having a urethane bond, and an organic solvent with a boiling point in the range of 115 to 200°C at atmospheric pressure, in which the (meth)acrylate compound having a siloxane bond is unevenly distributed on the surface side of the film, is said to have excellent stretchability and strength comparable to polyurethane, and the film surface has excellent water repellency comparable to silicone (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-206626 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the case of a resin sheet (resin film) whose main constituent material is a cured product of a resin composition as described in Patent Document 1, if the curing reaction does not proceed uniformly, variations in composition and degree of curing occur within the resin sheet, resulting in a problem that the resin sheet does not have the desired elasticity, strength, and resistance to deterioration over time.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a resin composition for producing a resin sheet that can constitute a stretchable device, the resin composition being capable of producing the resin sheet without undergoing a curing reaction, and a laminate including the resin sheet. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention employs the following configuration. [1] A resin composition, wherein a resin component in the resin composition has a group represented by the following general formula (11), (21) or (31), a urethane bond, and a siloxane bond, and the resin composition is solidified by drying to obtain a test resin sheet, which has a contact angle with water of 77 to 116°.

[0008] [ka] (In the formula, Z 1 is an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. 2 is an alkyl group. Z 3 is an aryl group. 4 is a hydrogen atom or a halogen atom. A bond marked with a symbol * is formed between the bond destination of the group represented by the general formula (11), (21), or (31).

[0009] [2] The resin composition according to [1], wherein the resin composition contains a resin component having a weight-average molecular weight of 52,000 to 250,000. [3] A laminate comprising a resin sheet obtained by solidifying the resin composition according to [1] or [2] by drying. [4] The laminate according to [3], further comprising a substrate layer containing a resin in addition to the resin sheet. [Effects of the Invention]

[0010] Since the resin component contained in the resin composition of the present invention has a urethane bond, a resin sheet formed using the resin composition has good stretchability. The resin component contained in the resin composition of the present invention has a siloxane bond, so the resin composition has appropriate water repellency and hydrolysis of the urethane bond in the resin component is suppressed, thereby suppressing deterioration of the resin sheet over time. The resin component contained in the resin composition of the present invention is obtained by carrying out a polymerization reaction using a RAFT agent for reversible addition-fragmentation chain transfer polymerization, from which the group represented by the general formula (11), (21), or (31) is derived. By carrying out the polymerization reaction in this manner, gelation of the polymer during the process of forming a crosslinked structure can be avoided, and a resin component with the desired degree of polymerization and crosslinked state can be obtained.

[0011] The resin sheet or support obtained using the resin composition of the present invention is produced by solidifying the resin composition by drying without curing, thereby resulting in little variation in composition, stretchability, and suppressed deterioration over time. Therefore, the resin sheet or support is suitable for, for example, constituting an element in a stretchable device. Furthermore, the laminate of the present invention including the resin sheet or support is suitable as a stretchable device, and furthermore, due to the effect of the resin sheet or support, structural defects, interfacial peeling, etc. are suppressed, resulting in high stability. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating an example of a laminate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention will be described in detail below. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto and can be appropriately changed within the scope of the present invention.

[0014] "Resin composition" The resin composition of this embodiment contains a resin component (sometimes referred to in this specification as "resin component (I)"), and the resin component has a group represented by the following general formula (11), (21), or (31), a urethane bond, and a siloxane bond. The resin composition is solidified by drying to obtain a test resin sheet, which has a contact angle with water of 77 to 116°.

[0015] [ka] (In the formula, Z 1 is an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. 2 is an alkyl group. Z 3 is an aryl group. 4 is a hydrogen atom or a halogen atom. A bond marked with a symbol * is formed between the bond destination of the group represented by the general formula (11), (21), or (31).

[0016] The resin component (I) contained in the resin composition of this embodiment has a urethane bond and therefore has high flexibility. Furthermore, because resin component (I) contains siloxane bonds, the resin composition has moderate water repellency and hydrolysis of the urethane bonds contained in resin component (I) is suppressed. Resin component (I) is obtained by polymerization using a resin containing a urethane bond and a polymerizable unsaturated bond and a resin containing a siloxane bond and a polymerizable unsaturated bond, and further using a RAFT agent for reversible addition-fragmentation chain transfer polymerization (hereinafter sometimes abbreviated as "RAFT polymerization"), from which the group represented by general formula (11), (21), or (31) is derived. By carrying out the polymerization reaction in this manner, gelation of the polymerized resin during the process of forming a crosslinked structure can be avoided, resulting in a resin component with the desired degree of polymerization and crosslinking state. That is, resin component (I) containing a group represented by general formula (11), (21), or (31) exhibits minimal variation in degree of polymerization and crosslinking state. The method for producing the resin component (I) by RAFT polymerization will be described in detail separately.

[0017] The resin having a urethane bond and a polymerizable unsaturated bond used in producing the resin component (I) is an oligomer, and in this embodiment may be referred to as "resin (a)." The resin having a siloxane bond and a polymerizable unsaturated bond used in producing the resin component (I) is an oligomer, and in this embodiment may be referred to as "resin (b)." The resin component (I) is a polymer produced by polymerizing the resin (a) and the resin (b) at their polymerizable unsaturated bonds.

[0018] The resin component (I) preferably has both a urethane bond and a siloxane bond in one molecule.

[0019] The resin (a) is not particularly limited as long as it has a urethane bond and a polymerizable unsaturated bond. Examples of the resin (a) include those having a urethane bond and a (meth)acryloyl group as the group having a polymerizable unsaturated bond, and more specifically, urethane (meth)acrylates and the like. In this specification, the term "(meth)acrylate" is a concept that encompasses both "acrylate" and "methacrylate." The same applies to terms similar to (meth)acrylate; for example, the term "(meth)acryloyl group" is a concept that encompasses both "acryloyl group" and "methacryloyl group."

[0020] The weight average molecular weight (Mw) of the resin (a) is preferably 3000 to 50000, more preferably 15000 to 50000. By using the resin (a) having such a weight average molecular weight, the resin component (I) having better properties can be obtained.

[0021] In this specification, the term "weight average molecular weight" refers to a polystyrene-equivalent value measured by gel permeation chromatography (GPC), not limited to the case of resin (a), unless otherwise specified.

[0022] The resin (b) is not particularly limited as long as it has a siloxane bond and a polymerizable unsaturated bond. Examples of the resin (b) include various known silicone resins having a (meth)acryloyl group as a group having a polymerizable unsaturated bond, and more specifically, examples thereof include modified polydialkylsiloxanes in which a (meth)acryloyl group is bonded to one or both ends of a polydialkylsiloxane such as polydimethylsiloxane.

[0023] The number average molecular weight (Mn) of the resin (b) is preferably 400 to 10000, more preferably 5000 to 10000. By using the resin (b) having such a number average molecular weight, the resin component (I) can be obtained with better properties.

[0024] In the general formula (11), Z 1is an alkyl group. Z 1 The alkyl group in the formula (I) may be any of linear, branched, and cyclic, but is preferably linear or branched, and more preferably linear.

[0025] Z 1 In the formula (I), the linear or branched alkyl group preferably has 1 to 12 carbon atoms, and examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a 1-methylbutyl group, a 2-methylbutyl group, a hexyl group, a heptyl group, an n-octyl group, an isooctyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. Z 1 The linear or branched alkyl group may have, for example, 1 to 8 carbon atoms, 1 to 5 carbon atoms, or 1 to 3 carbon atoms.

[0026] Z 1 The cyclic alkyl group in the formula (I) may be either monocyclic or polycyclic, but is preferably monocyclic. Z 1 In the above formula, the number of carbon atoms in the cyclic alkyl group is preferably 3 to 6, and examples of such an alkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.

[0027] Z 1 In the above formula, one or more hydrogen atoms in the alkyl group may or may not be substituted with a cyano group (-CN), a carboxy group (-C(=O)-OH), or a methoxycarbonyl group (-C(=O)-OCH3). Z 1 When two or more hydrogen atoms in the alkyl group in the formula (I) are substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, the two or more substituents may be the same or different.

[0028] When the hydrogen atom is substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, all of the hydrogen atoms in the alkyl group may be substituted, but it is preferable that an unsubstituted hydrogen atom exists, and the number of substituted hydrogen atoms is preferably 1 or 2, and more preferably 1.

[0029] Z 1 In the formula (I), examples of the alkyl group in which a hydrogen atom is substituted with a cyano group, a carboxy group, or a methoxycarbonyl group include a 1-carboxyethyl group (-CH(CH3)COOH), a 2-carboxyethyl group (-CH2CH2COOH), a 4-carboxy-2-cyano-sec-butyl group (-C(CH3)(CN)CH2CH2COOH), a 2-cyano-4-methoxycarbonyl-sec-butyl group (-C(CH3)(CN)CH2CH2COOCH3), a 1-cyano-1-methylethyl group (-C(CH3)(CN)CH3), a cyanomethyl group (-CH2CN), a 1-cyano-1-methyl-n-propyl group (-C(CH3)(CN)CH2CH3), and a 2-cyano-2-propyl group (-C(CH3)(CN)CH3). A 2-carboxyethyl group is preferred.

[0030] Z 1 is preferably a dodecyl group (n-dodecyl group) or a 2-carboxyethyl group.

[0031] In the general formula (21), Z 2 is an alkyl group. Z 2 The alkyl group in Z 1 Examples of the alkyl group include the same as those in the alkyl group.

[0032] Z 2 The alkyl group in the formula (I) is preferably linear or branched, and more preferably linear. Z 2The linear or branched alkyl group may have, for example, 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 5 carbon atoms, or 1 to 3 carbon atoms.

[0033] Z 2 is preferably a methyl group.

[0034] In the general formula (21), Z 3 is an aryl group. Z 3 The aryl group in the formula (I) may be either monocyclic or polycyclic, but is preferably monocyclic. Z 3 The number of carbon atoms in the aryl group in the formula (I) is preferably 6 to 12, and examples of such aryl groups include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, and a xylyl group (dimethylphenyl group).

[0035] Z 3 is preferably a phenyl group.

[0036] In the general formula (31), R 4 is a hydrogen atom or a halogen atom. R 4 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferred.

[0037] R 4 is preferably a hydrogen atom or a chlorine atom.

[0038] In the general formula (11), (21), or (31), the bond marked with * is formed between the group represented by the general formula (11), (21), or (31) and the terminal portion in the polymer of resin (a) or resin (b).

[0039] Examples of the RAFT agent from which the group represented by general formula (11) is derived include a compound represented by the following general formula (1) (sometimes abbreviated as "RAFT agent (1)" in this specification):

[0040] [ka] (In the formula, R 1 is an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. 1 is the same as above.)

[0041] R in the general formula (1) 1 In the above, examples of the alkyl group in which one or more hydrogen atoms may be substituted by a cyano group, a carboxy group or a methoxycarbonyl group include the above-mentioned Z 1 and R 1 The substitution of hydrogen atoms in Z 1 The substitution of hydrogen atoms is the same as in the above.

[0042] R 1 is preferably a 1-carboxyethyl group, a 4-carboxy-2-cyano-sec-butyl group, a 1-cyano-1-methylethyl group, a 2-cyano-4-methoxycarbonyl-sec-butyl group, a cyanomethyl group, or a 2-cyano-2-propyl group.

[0043] Z in the general formula (1) 1 represents Z in the general formula (11). 1 is the same as

[0044] When the RAFT agent (1) is used, the polymer of the resin (a) and the polymer of the resin (b) is polymerized to the terminal of the polymer to which the group represented by the general formula (11) is not bonded, and the R 1A group represented by the following formula is bonded to the ring.

[0045] Examples of the RAFT agent from which the group represented by general formula (21) is derived include a compound represented by the following general formula (2) (sometimes abbreviated as "RAFT agent (2)" in this specification).

[0046] [ka] (In the formula, R 2 is an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. 2 and Z 3 is the same as above.)

[0047] R in the general formula (2) 2 In the above, examples of the alkyl group in which one or more hydrogen atoms may be substituted by a cyano group, a carboxy group or a methoxycarbonyl group include the above-mentioned Z 1 and R 2 The substitution of hydrogen atoms in Z 1 The substitution of hydrogen atoms is the same as in the above.

[0048] R 2 is preferably a cyanomethyl group.

[0049] Z in the general formula (2) 2 and Z 3 represents Z in the general formula (21). 2 and Z 3 is the same as

[0050] When the RAFT agent (2) is used, the R2 A group represented by the following formula is bonded to the ring.

[0051] Examples of the RAFT agent from which the group represented by general formula (31) is derived include a compound represented by the following general formula (3) (sometimes abbreviated as "RAFT agent (3)" in this specification).

[0052] [ka] (In the formula, R 3 R is an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. 4 is the same as above.)

[0053] R in the general formula (3) 3 In the above, examples of the alkyl group in which one or more hydrogen atoms may be substituted by a cyano group, a carboxy group or a methoxycarbonyl group include the above-mentioned Z 1 and R 3 The substitution of hydrogen atoms in Z 1 The substitution of hydrogen atoms is the same as that in the above.

[0054] R 3 is preferably a cyanomethyl group or a 1-cyano-1-methyl-n-propyl group.

[0055] R in the general formula (3) 4 is R in the general formula (31). 4 is the same as

[0056] When the RAFT agent (3) is used, the polymer of the resin (a) and the polymer of the resin (b) is polymerized to the terminal of the polymer to which the group represented by the general formula (31) is not bonded, and the R 3A group represented by the following formula is bonded to the ring.

[0057] When producing the resin component (I), the resin (a) and the resin (b) may be used in combination with other polymerizable components that do not fall under these categories. Examples of the other polymerizable components include monomers or oligomers having a polymerizable unsaturated bond. More specific examples of the other polymerizable components include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, and decyl (meth)acrylate.

[0058] The resin composition of the present embodiment may, for example, contain a resin component (I) and a solvent, and may further contain other non-polymerizable components that do not fall into these categories, as necessary. The solvent is used in the production of the resin component (I), as will be described later.

[0059] The resin composition of this embodiment preferably contains resin component (I) in an amount of 5 to 100 mass %, more preferably 50 to 100 mass %, and the resin composition preferably contains solvent in an amount of 0 to 5 mass %, more preferably 0 to 0.5 mass %. Resin component (I) preferably contains 0 to 25.0 parts by mass of polymerized component of resin (b) per 100 parts by mass of polymerized component of resin (a), more preferably 0.35 to 15.0 parts by mass, and even more preferably 1.0 to 10.0 parts by mass. In the resin component (I), the group represented by general formula (11), (21), or (31) is preferably contained in an amount of 0.02 to 5.0 parts by mass, more preferably 0.05 to 4.0 parts by mass, and even more preferably 0.37 to 3.20 parts by mass, per 100 parts by mass of the polymerizable components of the resin (a). Resin component (I) preferably contains 0 to 2000 parts by mass, more preferably 0 to 100 parts by mass, and even more preferably 0 to 50 parts by mass of other polymerizable components per 100 parts by mass of the polymerizable components of resin (a). The resin composition preferably contains 500 to 4000 parts by mass, more preferably 800 to 2000 parts by mass, and even more preferably 800 to 1300 parts by mass of other non-polymerizable components per 100 parts by mass of the polymerizable components of resin (a).

[0060] The other non-polymerizable component can be selected arbitrarily depending on the purpose, and may be, for example, either a conductive component or a non-conductive component, more preferably a non-conductive component. For example, by using the resin composition containing a conductive component, the resin sheet containing the conductive component and having stretchability and conductivity can be obtained. Such a resin sheet is suitable for forming electrodes or wiring in a stretchable device, for example. On the other hand, the resin sheet obtained using the resin composition containing a non-conductive component (containing no conductive component) is suitable for forming an element in a stretchable device. Here, examples of the element include a sealing layer for sealing the stretchable device, or a layer for providing wiring, electrodes, metal-plated members, electronic components, etc.

[0061] Examples of the conductive component include metals such as silver and copper, and the metals are preferably in the form of particles (for example, silver particles, copper particles, etc.).

[0062] The resin composition of this embodiment preferably does not contain a curing agent (e.g., a thermosetting agent), or if it does contain a curing agent, the lower the content of the curing agent is, the more advantageous it is. Such a resin composition is advantageous in that it can be solidified without undergoing a curing reaction, resulting in a significant effect. This effect will be described in detail later.

[0063] The test resin sheet obtained by solidifying the resin composition of this embodiment by drying has a water contact angle of 77 to 116°. When the water contact angle is 77° or more, the test resin sheet is highly effective in suppressing the hydrolysis of the urethane bond in the resin component (I). When the water contact angle is 116° or less, the test resin sheet has high flexibility (stretchability).

[0064] In this way, the test resin sheet for determining the water contact angle is produced by applying the resin composition to the target location and solidifying it by drying, without carrying out a curing reaction, and the drying temperature of the resin composition at this time is 90° C., and the resin composition is at the stage where no clear change in mass is observed due to drying. To produce such a test resin sheet, the drying time should be approximately 15 minutes or more.

[0065] In this embodiment, it is preferable that water is dropped onto the surface of the test resin sheet, and the contact angle with water is 77 to 116° within 3 to 13 seconds after the drop. Such a test resin sheet has a more pronounced effect of suppressing hydrolysis of urethane bonds in the resin component (I) and an effect of increasing the flexibility (stretchability) of the test resin sheet.

[0066] The test resin sheet may have a contact angle with water of 93 to 116.5°. In this embodiment, when water is dropped onto the surface of the test resin sheet, the contact angle with water 3 seconds after the drop is preferably 93 to 116.5°. Such a test resin sheet also has a more pronounced effect of suppressing hydrolysis of the urethane bond in the resin component (I) and an effect of increasing the flexibility (stretchability) of the test resin sheet.

[0067] When measuring the contact angle with water, the amount of water dropped onto the test resin sheet is not particularly limited as long as the contact angle with water can be measured with high precision, but is preferably 1 to 3 μL. The contact angle of the test resin sheet with water can be measured using a solid-liquid interface analyzer.

[0068] The weight average molecular weight (Mw) of the resin component (I) is preferably 52000 to 250000, more preferably 61000 to 250000, and even more preferably 100000 to 250000. Such a resin component (I) has better properties.

[0069] "Method of manufacturing resin composition" The resin composition can be produced, for example, by preparing a raw material mixture containing resin (a), resin (b), a RAFT agent (i.e., RAFT agent (1), RAFT agent (2), or RAFT agent (3)), a polymerization initiator (sometimes referred to herein as "polymerization initiator (c)"), a solvent, and, if necessary, the other polymerizable component(s), and, if necessary, the other non-polymerizable component(s), and by carrying out a polymerization reaction in the raw material mixture to produce resin component (I).

[0070] The raw material mixture is a type of resin composition containing resin (a) and resin (b). In this specification, the mere expression "resin composition" does not mean the raw material mixture before the polymerization reaction, but means a resin composition that contains resin component (I) and is a raw material for producing the resin sheet.

[0071] The raw material mixture may contain only one type of resin (a), or two or more types of resins.

[0072] In the raw material mixture, the content of resin (a) is preferably 9.6 to 30 mass% and more preferably 11 to 25 mass% relative to the total amount of the raw material mixture. When the content is 9.6 mass% or more, it becomes easier to produce a resin sheet by drying and solidifying the resin composition. When the content is 30 mass% or less, it becomes easier to improve the handleability of the resin composition using a solvent.

[0073] The raw material mixture may contain only one type of resin (b), or two or more types of resins.

[0074] In the raw material mixture, the content of resin (b) is preferably 0.2 to 25 parts by mass, more preferably 0.2 to 20 parts by mass, and even more preferably 0.2 to 17 parts by mass, per 100 parts by mass of resin (a) plus other polymerizable components. When the content is 0.2 parts by mass or more, the water repellency of the resin composition is more significantly improved. When the content is 25 parts by mass or less, excessive use of resin (b) is avoided, and for example, the resin composition is prevented from becoming unnecessarily hard or from becoming less uniform.

[0075] The raw material mixture may contain only one type of RAFT agent (RAFT agents (1) to (3)), or may contain two or more types of RAFT agents, but usually only one type is sufficient.

[0076] In the raw material mixture, the content of the RAFT agent is preferably 0.03 to 5 parts by mass, more preferably 0.03 to 4.5 parts by mass, and even more preferably 0.03 to 4 parts by mass, relative to 100 parts by mass of resin (a) and other polymerizable components. When the content is 0.03 parts by mass or more, the effect of using the RAFT agent is more pronounced. When the content is 5 parts by mass or less, excessive use of the RAFT agent can be avoided.

[0077] The polymerization initiator (c) may be a known one and is not particularly limited. Examples of the polymerization initiator (c) include dimethyl 2,2'-azobis(2-methylpropionate) and azobisisobutyronitrile.

[0078] The raw material mixture may contain only one type of polymerization initiator (c), or two or more types, but usually only one type is sufficient.

[0079] In the raw material mixture, the content of the polymerization initiator (c) is preferably 0.5 to 5 parts by mass, more preferably 0.7 to 4 parts by mass, and even more preferably 0.9 to 3 parts by mass, relative to 100 parts by mass of the resin (a) and other polymerizable components. When the content is 0.5 parts by mass or more, the polymerization reaction proceeds more smoothly. When the content is 5 parts by mass or less, excessive use of the polymerization initiator (c) can be avoided.

[0080] The solvent is not particularly limited as long as it does not exhibit reactivity with the above-mentioned blended components used in preparing the raw material mixture or with the polymerization reactants, but it is preferable that the solvent has good solubility for the blended components. Examples of the solvent include methyl ethyl ketone (MEK), butyl carbitol acetate, polyethylene glycol methyl ethyl acetate, and ethyl carbitol acetate.

[0081] The raw material mixture may contain only one type of solvent, or two or more types of solvents.

[0082] The raw material mixture preferably contains a solvent so that 100 parts by mass of resin (a) plus other polymerizable components accounts for 5 to 30% by mass of the total raw material mixture, and more preferably 10 to 25% by mass of resin (a) plus other polymerizable components accounts for 100 parts by mass of the total raw material mixture. When the amount of the solvent used is within this range, the resin component (I) having better properties can be obtained more smoothly.

[0083] The raw material mixture may contain only one type of other polymerizable component, or two or more types of other polymerizable components.

[0084] When the other polymerizable component is used, the content of the other polymerizable component in the raw material mixture is preferably 5 to 55 parts by mass, more preferably 10 to 50 parts by mass, and even more preferably 15 to 45 parts by mass, per 100 parts by mass of the resin (a). When the content is 5 parts by mass or more, the effect of using the other polymerizable component is more pronounced. When the content is 55 parts by mass or less, the stretchability of the resin sheet obtained using the resin composition is further improved, and deterioration of the resin sheet over time is further suppressed.

[0085] The raw material mixture may contain only one type of other non-polymerizable component, or two or more types of other non-polymerizable components.

[0086] In the raw material mixture, the content of the curing agent is preferably 0 to 0.01 parts by mass, and particularly preferably 0 parts by mass, i.e., the raw material mixture does not contain a curing agent, relative to 100 parts by mass of the resin (a) and other polymerizable components. Such a resin composition is advantageous in that it does not substantially or completely undergo a curing reaction, thereby providing significant effects.

[0087] In the raw material mixture, the total content of resin (a), resin (b), RAFT agent, polymerization initiator (c), and other optional polymerizable components is preferably 90 to 100 parts by mass, more preferably 95 to 100 parts by mass, and may be, for example, 97 to 100 parts by mass or 99 to 100 parts by mass, relative to 100 parts by mass of the total content of components other than the solvent in the raw material mixture. When the content is 90 parts by mass or more, the effects of the present invention are more pronounced.

[0088] The polymerization reaction is preferably carried out in an atmosphere of an inert gas such as nitrogen gas, helium gas, or argon gas.

[0089] The temperature at which the polymerization reaction is carried out (reaction temperature) is preferably 70 to 110°C, and more preferably 80 to 100°C.

[0090] The polymerization reaction time (reaction time) may be adjusted appropriately depending on the types of raw materials used and the reaction temperature, and can be set to, for example, 5 to 240 minutes.

[0091] In this embodiment, the polymerization reaction of resin (a) and resin (b) is carried out using RAFT agent (1), (2), or (3), allowing the polymerization reaction to proceed stably, resulting in stable production of resin component (I) such that the composition, molecular weight distribution, structure, etc. of resin component (I) fall within certain ranges. In particular, the reaction rate is appropriately controlled during the polymerization reaction, which prevents the reaction from proceeding too quickly, resulting in a rapid increase in the viscosity of the reaction solution and gelation during the process of forming a crosslinked structure. This allows stable production of resin component (I) with the desired degree of polymerization and crosslinked state.

[0092] In addition to RAFT polymerization using a RAFT agent, other known radical polymerization methods include atom transfer radical polymerization (ATRP) and nitroxide-mediated polymerization (NMP). However, ATRP has the drawback of requiring a high concentration of a transition metal-containing catalyst to carry out the polymerization reaction, while NMP has the drawback of making it difficult to control the polymerization reaction and limiting its versatility. Due to these drawbacks, these methods are not suitable for producing the resin component (I) that is the target of the present invention. In contrast, in the present embodiment, by selecting RAFT polymerization using RAFT agent (1), (2), or (3), a resin component (I) having the desired properties can be produced stably with high versatility.

[0093] In this embodiment, after the polymerization reaction, the resulting reaction liquid may be used as the resin composition as is, or the resulting reaction liquid may be subjected to a known post-treatment to obtain the resin composition.

[0094] "Laminate" The laminate of the present embodiment includes a resin sheet obtained by drying and solidifying the resin composition. The resin sheet contains resin component (I) as a main component, and therefore has good stretchability and moderate water repellency, which inhibits deterioration over time due to hydrolysis. The resin sheet having such properties is particularly suitable for constructing various stretchable devices, including wearable devices. For example, the resin sheet is suitable for constituting an element in a stretchable device. Examples of the element include a sealing layer for sealing the stretchable device, or a layer for providing wiring, electrodes, metal-plated members, electronic components, etc. That is, the laminate of this embodiment is particularly suitable for use as a stretchable device.

[0095] The resin sheet can be formed by simply solidifying the resin composition by drying, as described above, without carrying out a curing reaction of the resin composition, and therefore does not have the drawbacks associated with carrying out a curing reaction.

[0096] For example, it is extremely difficult to uniformly cure a material that is not transparent to ultraviolet light in a photocurable resin sheet. For example, when ultraviolet light is irradiated around a mounted device or electronic component in a photocurable resin sheet, the transmittance of ultraviolet light varies, resulting in areas with different degrees of cure, and the resin sheet is prone to breakage in areas with low crosslink density. Furthermore, non-crosslinked areas are prone to deterioration due to oxidation. On the other hand, the thermosetting reaction tends to cause differential shrinkage in the resin sheet due to heat distribution during curing. Such differential shrinkage can easily cause separation at the interface between different constituent materials, such as between a device and a sealant. Furthermore, if regions with different degrees of cure occur in the resin sheet due to heat distribution, repeated expansion and contraction can easily cause deterioration. Furthermore, in both the photocuring reaction and the thermosetting reaction, it is difficult for the reaction to proceed uniformly within the resin sheet, which results in variations in composition and degree of curing within the resin sheet, and the cured resin sheet does not have the desired elasticity and strength. In contrast, the resin sheet obtained by solidifying the resin composition of the present embodiment through drying does not have such a problem.

[0097] The resin sheet can be produced, for example, by applying the resin composition to a desired location and solidifying it by drying, without carrying out a curing reaction.

[0098] The resin composition can be applied by a known method using, for example, various coaters or wire bars.

[0099] During the production of the resin sheet, the drying temperature of the resin composition is preferably 25 to 150° C., and may be, for example, 70 to 120° C. When the drying temperature is 25° C. or higher, the resin sheet can be produced more efficiently. When the drying temperature is 150° C. or lower, the drying temperature is prevented from becoming excessively high, deformation of the release sheet and damage to the resin sheet are less likely to occur, and deterioration of the resin sheet is suppressed.

[0100] In producing the resin sheet, the drying time of the resin composition may be appropriately set depending on the drying temperature, but is preferably 10 to 120 minutes, more preferably 10 to 90 minutes. When the drying time is within this range, a resin sheet with good properties can be efficiently produced.

[0101] Completion of solidification (formation of a resin sheet) by drying of the resin composition can be confirmed, for example, by the fact that no clear change in the mass of the resin composition being dried is observed any more.

[0102] The resin sheet included in the laminate may be only one layer (sheet), or may be two or more layers (sheets). When the laminate includes two or more resin sheets, these two or more resin sheets may be the same or different from each other.

[0103] In this specification, not only in the case of resin sheets, "two or more layers may be the same or different" means "all layers may be the same, all layers may be different, or only some layers may be the same", and further "two or more layers are different" means "at least one of the constituent materials and thicknesses of each layer is different from each other". For example, the laminate having two or more layers of the resin sheet may include a resin sheet provided with wiring, electrodes, metal-plated members, electronic components, etc., and a resin sheet that does not have these and functions as a sealing layer, but this is just one example of the laminate.

[0104] The thickness of one layer of the resin sheet is preferably 1 to 2000 μm, and may be, for example, 5 to 1000 μm. When the thickness of the resin sheet is 1 μm or more, the strength of the resin sheet is further improved. When the thickness of the resin sheet is 2000 μm or less, the resin sheet can be used with low stress when bent.

[0105] The test resin sheet described above is an example of the resin sheet that constitutes the laminate of this embodiment.

[0106] The resin sheet constituting the laminate of this embodiment exhibits a contact angle with water similar to that of the test resin sheet.

[0107] FIG. 1 is a schematic exploded view showing an example of the laminate of the present embodiment. In addition, the drawings used in the following explanation may show enlarged essential parts for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

[0108] The laminate 1 shown here is configured by laminating a first sheet 11, a second sheet 12, a third sheet 13, and a fourth sheet 14 in this order in the thickness direction. In this specification, these four layers (sheets) of resin sheets may be collectively referred to as "first sheet 11 to fourth sheet 14."

[0109] The first sheet 11 is configured by providing electrodes 111 together with wiring on the surface of the resin sheet 10 facing the second sheet 12. The second sheet 12 is formed by embedding or attaching a copper-plated member 121 in the resin sheet 10. The second sheet 12 is also provided with vias or connection portions for connecting to wiring on other sheets. The third sheet 13 is configured by embedding or mounting electronic components 131 in the resin sheet 10. The third sheet 13 is also provided with vias or connection parts for connecting to wiring on other sheets. The fourth sheet 14 is composed of the resin sheet 10 only.

[0110] All of the resin sheets 10 in the first sheet 11 to the fourth sheet 14 are the resin sheets of this embodiment described above.

[0111] When the first sheet 11 to the fourth sheet 14 are stacked, the wiring and electrodes 111 on the first sheet 11 contact the copper-plated members 121 in the second sheet 12, and the copper-plated members 121 contact the electronic components 131 in the third sheet 13. The fourth sheet 14 is provided on the first sheet 11, the second sheet 12, and the third sheet 13 so that the wiring and electrodes 111, the copper-plated members 121, and the electronic components 131 are not exposed, and functions as a sealing layer.

[0112] The laminate 1 can be used as a stretchable device such as a wearable device, and the wiring and electrodes 111, the copper-plated member 121, and the electronic component 131 may be those known in the art.

[0113] The laminate 1 can be produced by laminating the first sheet 11, the second sheet 12, the third sheet 13, and the fourth sheet 14 in this order. The order in which these sheets are stacked when producing the laminate 1 is not particularly limited.

[0114] The first sheet 11 can be produced, for example, by applying a conductive composition for forming wiring and electrodes 111 to one surface of the resin sheet 10 by a printing method, and drying the composition to form a conductive layer. The resin sheet 10 can be produced by the production method described above.

[0115] The second sheet 12 can be produced, for example, by placing a copper-plated member 121 on the surface of the first sheet 11 on which the wiring and electrodes 111 are formed, and then applying the resin composition to the surface of the first sheet 11 on which the wiring and electrodes 111 are formed, and then drying and solidifying the resin composition. At this time, the copper-plated member 121 penetrates the second sheet 12. The second sheet 12 can also be produced by applying the composition to the surface of the first sheet 11 on which the wiring and electrodes 111 are formed, solidifying it, and then attaching the copper-plated member 121 to the resulting product.

[0116] The third sheet 13 can be produced, for example, by placing electronic components 131 on the surface of the second sheet 12 opposite to the first sheet 11 side, and then applying the resin composition to the surface of the second sheet 12 opposite to the first sheet 11 side (i.e., the surface on which electronic components 131 are placed) and drying to solidify it. At this time, the electronic components 131 are made to penetrate through the third sheet 13.

[0117] The fourth sheet 14 can be produced by applying the resin composition to the surface of the third sheet 13 opposite to the second sheet 12 side, and then drying and solidifying it. The method shown here is an example of a method for manufacturing the laminate 1.

[0118] The laminate of this embodiment is not limited to that shown in FIG. 1, and some of the configuration may be changed, deleted, or added within the scope of the gist of the present invention. For example, the sheet constructed using the resin composition of this embodiment has four layers in the laminate 1, but it may have one layer or a number of layers other than four, i.e., one layer or two or more layers. The number of sheets in the laminate can be set arbitrarily depending on the purpose of the laminate. However, when the sheet has one layer, the laminate is to have another layer other than the sheet. Furthermore, the sheet made using the resin composition of the present embodiment includes wiring, electrodes, copper-plated members, or electronic components in the laminate 1, but may also include other components.

[0119] The laminate 1 includes only sheets constructed using the resin sheet of this embodiment, but the laminate of this embodiment may also include other sheets (layers) that do not use the resin sheet of this embodiment. That is, the laminate of the present embodiment may further include other sheets (other layers) in addition to the resin sheet. The other layer may be, for example, a base layer containing a resin.

[0120] The base layer can be arbitrarily selected depending on the purpose of the laminate, and may be a known base layer without any particular limitation. Examples of the substrate layer include an adhesive layer for attaching the laminate to an object to which it is to be used, and a release sheet that is attached to one or both sides of the laminate to protect the laminate during storage and that can be easily peeled off from the laminate when the laminate is to be used, but these are merely examples of the substrate layer.

[0121] The thickness of the substrate layer is not particularly limited, but is usually preferably 10 to 2000 μm, and more preferably 20 to 1000 μm. When the thickness of the substrate layer is 10 μm or more, the strength of the substrate layer is further improved. When the thickness of the substrate layer is 2000 μm or less, the substrate layer can be more easily produced.

[0122] An example of the laminate including the base material layer is the laminate 1 shown in Fig. 1, in which a base material layer is additionally provided on the exposed surface of the first sheet 11 or the exposed surface of the fourth sheet 14. However, this is just one example of a laminate including a base material layer. [Example]

[0123] The present invention will be described in more detail below with reference to specific examples, although the present invention is not limited to the examples shown below.

[0124] The raw materials used in producing the resin composition are shown below. Resin (a) (a)-1: Urethane acrylate oligomer (product name: UN-5500, manufactured by Negami Chemical Industrial Co., Ltd.) ·Resin (b) (b)-1: Methacrylate-modified polydimethylsiloxane in which one end is modified with a methacryloyl group (product name: Silaplane (registered trademark) FM-0721, manufactured by JNC Corporation) Polymerization initiator (c) (c)-1: Dimethyl 2,2'-azobis(2-methylpropionate), azo polymerization initiator (product name: V601, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) RAFT agents (1)-1: RAFT agent represented by the following formula (1)-1 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (3)-1: RAFT agent represented by the following formula (3)-1 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) Other polymerizable components MMA: methyl methacrylate ·solvent MEK: Methyl ethyl ketone BCA: butyl carbitol acetate

[0125] [ka]

[0126] [Example 1] <Production of Resin Composition> Resin (a)-1 (100 parts by mass), resin (b)-1 (2 parts by mass), polymerization initiator (c)-1 (1.2 parts by mass), RAFT agent (1)-1 (2.946 parts by mass), and MEK were weighed into a flask and mixed at room temperature using a stirrer to obtain a raw material mixture. In the present invention, the blending amounts of resin (b), polymerization initiator (c), and RAFT agent are determined based on 100 parts by mass of resin (a) + other polymerizable components. However, in Example 1, no other polymerizable components were used, and therefore the blending amounts of resin (b), polymerization initiator (c), and RAFT agent were determined based on 100 parts by mass of resin (a). Furthermore, MEK, which is a solvent, was mixed in such that 100 parts by mass of resin (a) accounted for 25% by mass of the raw material mixture.

[0127] The resulting raw material mixture was then cooled and solidified using liquid nitrogen, and the sealed flask was evacuated to degass it. Next, the raw material mixture was dissolved in an oil bath under a nitrogen atmosphere, and the temperature was raised while continuing to stir, and a polymerization reaction was carried out at 90°C for 55 minutes to produce resin component (I) and a resin composition containing this resin component (I).

[0128] <Evaluation of Resin Composition> (Measurement of weight average molecular weight of resin component (I)) Three GPC columns (product name: Shodex® LF-404, manufactured by Showa Denko K.K.) were connected in series, and the weight-average molecular weight (Mw) of the resin component (I) obtained above was measured using a molecular weight analyzer (product name: Shodex® GPC-104, manufactured by Showa Denko K.K.) with the temperature of the GPC columns set to 40°C and tetrahydrofuran (THF) as the mobile phase. The weight-average molecular weight was calculated using a calibration curve prepared in advance. The results are shown in Table 3.

[0129] (Measurement of viscosity of resin composition, calculation of viscosity ratio (1 rpm / 10 rpm)) The resin composition obtained above was dissolved in butyl carbitol acetate (BCA) to prepare a butyl carbitol acetate solution of the resin composition (BCA solution) having a resin composition concentration of 15 mass %. Next, using a digital viscometer (BROOKFIELD viscometer HB DV-1 Prime, spindle: S21 type), the BCA solution obtained above was stirred for 5 minutes at a stirring speed of 10 rpm in an atmosphere in which cooling water at a temperature of 25°C was circulated through the measuring tube. After allowing to stand for 5 minutes, the viscosity was measured while stirring at a stirring speed of 1 rpm (viscosity (1 rpm)). After allowing to stand for another 1 minute, the viscosity was measured while stirring at a stirring speed of 10 rpm (viscosity (10 rpm)). The viscosity ratio (1 rpm / 10 rpm) was then calculated. The results are shown in Table 2.

[0130] <Manufacturing of resin sheets> The resin composition obtained above was applied to a release film using an applicator and dried at 25°C for 18 minutes to produce a resin sheet (test resin sheet, thickness 2 μm) without undergoing a curing reaction.

[0131] <Evaluation of resin sheets> (Measurement of contact angle with water) Using a solid-liquid interface analyzer (product name: DropMaster500, manufactured by Kyowa Interface Science Co., Ltd.) and a 22G syringe set equipped with a polytetrafluoroethylene-coated needle, 2 μL of pure water was dropped onto the surface of the resin sheet obtained above, and the contact angle was measured in 22G mode at 3, 8, and 13 seconds after dropping. The results are shown in Table 3.

[0132] (Measurement of contact angle with MEK, calculation of contact angle ratio (3 seconds / 13 seconds)) Using a solid-liquid interface analyzer (product name: DropMaster500, manufactured by Kyowa Interface Science Co., Ltd.) and a 22G syringe set equipped with a polytetrafluoroethylene-coated needle, 2.2 μL of special-grade MEK was deposited on the surface of the resin sheet (thickness: 3 μm) obtained above under atmospheric conditions. The contact angles were measured in 22G mode at 3 and 13 seconds after deposition, and the contact angle ratio (3 seconds / 13 seconds) was calculated. The results are shown in Table 2. The change in the contact angle between 3 and 13 seconds is due to the MEK dissolving the resin film. The small amount of MEK volatilizing between 3 and 13 seconds also has some influence on the change in the value.

[0133] <Production and Evaluation of Resin Composition, Production and Evaluation of Resin Sheet> [Examples 2 to 16] Resin compositions were produced and evaluated, and resin sheets were produced and evaluated in the same manner as in Example 1, except that either or both of the types and amounts of the components of the raw material mixture for obtaining the resin composition, or the polymerization reaction time, were changed as shown in Table 1. In Examples 2 to 16, resin (b), polymerization initiator (c), and RAFT agent were mixed in the amounts shown in Table 1, based on 100 parts by mass of resin (a) plus other polymerizable components. In Examples 4 and 5, the resin (a) + other polymerizable components = 140 parts by mass, but this is converted to 100 parts by mass and the resin (b), polymerization initiator (c), and RAFT agent were mixed in the amounts shown in Table 1. In Examples 2 to 13, MEK was added as a solvent so that 100 parts by mass of resin (a) plus other polymerizable components accounted for 25% by mass of the resin composition. In Examples 14 to 16, BCA was added as a solvent so that 100 parts by mass of resin (a) plus other polymerizable components accounted for 15% by mass of the raw material mixture. Regarding the production of the resin sheets, in Examples 2 to 13, the resin sheets were produced in the same manner as in Example 1. In Examples 14 to 16, the resin composition containing BCA obtained above was applied onto a release film using an applicator, and dried at 115°C for 60 minutes to produce a resin sheet (test resin sheet, thickness 2 μm) without undergoing a curing reaction. In Table 1, "-" in the "Components of raw material mixture (parts by mass)" column means that the component is not blended. Also, the blend amount of "solvent" is omitted.

[0134] [Table 1]

[0135] [Table 2]

[0136] [Table 3]

[0137] As shown in Table 3, in Examples 1 to 16, the contact angle of the resin sheet with water was 76 to 112.7° when the time after the pure water was applied was between 3 and 13 seconds, and the resin sheet had appropriate water repellency.

[0138] As described above, the resin sheets of Examples 1 to 16 have good stretchability due to the resin component (I) having urethane bonds, and furthermore, have moderate water repellency, which inhibits hydrolysis of the urethane bonds and inhibits deterioration over time. In other words, these resin sheets were suitable for forming the element of a stretchable device. [Industrial Applicability]

[0139] The present invention can be used for stretchable devices and their manufacture. [Explanation of symbols]

[0140] REFERENCE SIGNS LIST 1 laminate, 10 resin sheet, 11 first sheet, 12 second sheet, 13 third sheet, 14 fourth sheet, 111 electrode, 121 copper-plated member, 131 electronic component

Claims

1. A resin composition containing a resin component, The content ratio of the resin component in the resin composition is 5 to 100% by mass, The resin component contains a polymer of a resin (a) having a urethane bond and a polymerizable unsaturated bond and a resin (b) having a siloxane bond and a polymerizable unsaturated bond, and has a group represented by the following general formula (11), (21), or (31): The weight average molecular weight (Mw) of the resin component is 52,000 to 250,000, A test resin sheet obtained by solidifying the resin composition by drying has a contact angle with water of 77 to 116°. 【Chemical 1】 (In the formula, Z １ represents an alkyl group, and one or more hydrogen atoms in the alkyl group may be substituted with a cyano group, a carboxy group, or a methoxycarbonyl group, and the two or more substituents may be the same or different. ２ is an alkyl group. ３ is an aryl group. ４ is a hydrogen atom or a halogen atom. A bond marked with a symbol * is formed between the bond destination of the group represented by the general formula (11), (21), or (31).

2. A laminate comprising a resin sheet obtained by drying and solidifying the resin composition according to claim 1.

3. The laminate according to claim 2 , further comprising a base layer containing a resin in addition to the resin sheet.

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