Polyrotaxane, method for producing polyrotaxane, curable composition, and cured product

Abstract

The present invention relates to a polyrotaxane which has one or more cyclic molecules, a linear molecule, and blocking groups that are positioned at both ends of the linear molecule, wherein the cyclic molecules enclose the linear molecule passing through the openings of the cyclic molecules, and some or all of the cyclic molecules have a polysiloxane chain and a group X that has a crosslinkable group. A polyrotaxane according to the present invention has excellent compatibility when added into a curable composition that contains a silicone resin, and the elongation properties of a cured product of a curable composition is improved by adding the polyrotaxane according to the present invention into the curable composition.

Description

Polyrotaxane, method for producing polyrotaxane, curable composition, cured product

[0001] The present invention relates to a polyrotaxane, a method for producing a polyrotaxane, a curable composition containing the polyrotaxane, and a cured product formed from the curable composition. This application claims priority under Japanese Patent Application No. 2025-026542, filed in Japan on February 21, 2025, the contents of which are incorporated herein by reference.

[0002] In recent years, the technology of incorporating polyrotaxanes has attracted attention as a way to improve the elongation of rubber and resin materials. Polyrotaxanes are molecular assemblies in which linear molecules are slidably inserted through cyclic molecules, and the cyclic molecules are prevented from detaching by sealing groups located at both ends of the linear molecules. They are also known as slide-ring materials.

[0003] As an example of incorporating polyrotaxane into rubber materials, Patent Document 1 discloses a crosslinked rubber composition in which polyrotaxane having vinyl groups is sulfur-crosslinked with ethylene propylene diene rubber (EPDM) to improve tensile strength, tensile elongation rate, and compression set.

[0004] Furthermore, the examples in Patent Document 2 disclose a crosslinked rubber composition in which a polyrotaxane having a mercapto group in its cyclic molecule is sulfur-crosslinked with styrene-butadiene rubber (SBR) to improve durability.

[0005] Among rubber and resin materials, silicone viscoelastic materials such as silicone gels and silicone rubbers are used in various fields such as electronic equipment, construction, and medicine because they possess various properties such as flexibility, elongation, heat resistance, light resistance, and light transmittance. In recent years, with the diversification of applications, there has been a demand to further improve the properties of silicone viscoelastic materials. In particular, in applications such as sealing materials for electrical and electronic components, coating materials for sensors, potting materials, damping materials, heat dissipation materials, and optical adhesives (OCR, OCA), there is a demand for silicone viscoelastic materials with excellent deformation-following properties to withstand stronger impacts and larger vibrations. Therefore, there is a growing need for silicone resin compositions that form silicone viscoelastic materials with high deformation-following properties, that is, excellent elongation.

[0006] Japanese Patent Publication No. 2015-203037 Japanese Patent Publication No. 2018-024768

[0007] However, even when attempting to incorporate polyrotaxane into a curable composition primarily composed of silicone resin, the poor compatibility between silicone resin and polyrotaxane prevented the achievement of high elongation through the application of polyrotaxane, as was the case with other rubber materials.

[0008] The present invention aims to provide a polyrotaxane that exhibits excellent compatibility when incorporated into a curable composition containing a silicone resin, and that can improve the elongation of the cured product.

[0009] The present invention has the following embodiments: <1> A polyrotaxane having one or more cyclic molecules, a linear molecule, and choke groups located at both ends of the linear molecule, wherein the cyclic molecule encloses the linear molecule penetrating its opening, and part or all of the cyclic molecule has a polysiloxane chain and a group X having a crosslinking group. <2> The polyrotaxane according to <1>, wherein the cyclic molecule has a hydroxyl group, and at least a portion of the hydrogen atoms of the hydroxyl group are substituted with the group X. <3> The polyrotaxane according to <1> or <2>, wherein the cyclic molecule further has a group Y, and the group Y does not contain a polysiloxane chain and has a crosslinking group. <4> The polyrotaxane according to <3>, wherein the cyclic molecule has a hydroxyl group, and at least a portion of the hydrogen atoms of the hydroxyl group are substituted with the group X or the group Y. <5> The polyrotaxane according to any one of <1> to <4>, wherein the cyclic molecule further has a group Z, and the group Z does not contain a polysiloxane chain or a crosslinking group but has a non-crosslinking group. <6> The polyrotaxane according to <5>, wherein the cyclic molecule has a hydroxyl group, and at least a portion of the hydrogen atoms of the hydroxyl group are substituted with the group X or the group Z. <7> A method for producing a polyrotaxane, comprising: dissolving compound A, which has one or more cyclic molecules, linear molecules, and chelating groups located at both ends of the linear molecules, wherein the cyclic molecules enclose the linear molecules penetrating through their openings, and the cyclic molecules have hydroxyl groups, in an organic solvent; ring-opening addition of a cyclic siloxane to at least a portion of the hydroxyl groups of the cyclic molecules to form a polysiloxane chain having hydroxyl groups at its termini to obtain compound B; and reacting compound C, which has a crosslinking group and reacts with a hydroxyl group, with compound B to introduce the crosslinking group to at least a portion of the termini of the polysiloxane chain.<8> A method for producing a polyrotaxane, comprising: dissolving compound A, which has one or more cyclic molecules, linear molecules, and chelating groups located at both ends of the linear molecules, wherein the cyclic molecules enclose the linear molecules penetrating through their openings, and the cyclic molecules have hydroxyl groups, in an organic solvent; ring-opening addition of a cyclic siloxane to at least a portion of the hydroxyl groups of the cyclic molecules to form a polysiloxane chain having hydroxyl groups at its termini to obtain compound B; reacting compound D, which has halogen groups and reacts with hydroxyl groups, with compound B to introduce the halogen groups to at least a portion of the termini of the polysiloxane chain, and then substituting the halogen groups with mercapto groups. <9> A curable composition containing the polyrotaxane described in any one of <1> to <6> above and an organopolysiloxane having crosslinkable groups. <10> A cured product formed from the curable composition described in <9> above.

[0010] According to the present invention, a polyrotaxane can be obtained that exhibits excellent compatibility when blended into a curable composition containing a silicone resin, and that can improve the elongation of the cured product. The curable composition of the present invention can form a cured product with excellent elongation.

[0011] The following definitions of terms apply throughout this specification and the claims. A numerical range indicated by "~" means that the numbers preceding and following it are included as the lower and upper limits. The lower and upper limits of the numerical ranges disclosed herein may be combined in any way to form new numerical ranges.

[0012] <<Polyrotaxane>>The polyrotaxane of the present embodiment is a molecular assembly having one or more cyclic molecules, a linear molecule, and blocking groups located at both ends of the linear molecule. The cyclic molecule includes the linear molecule penetrating through the opening thereof. Some or all of the one or more cyclic molecules have a specific group X. In this specification, one molecule of polyrotaxane means the molecular assembly in which the linear molecule is one molecule. In this specification, a structure in which the opening of the cyclic molecule is pierced by the linear molecule in a skewer-like manner is also referred to as a pseudo-polyrotaxane structure. A structure in which blocking groups are bonded to both ends (both ends of the linear molecule) of the pseudo-polyrotaxane structure so that the cyclic molecule does not dissociate is also referred to as a polyrotaxane structure.

[0013] <Linear molecule>The linear molecule constituting the polyrotaxane is a molecule or substance that can be included in the cyclic molecule and integrated with the cyclic molecule by non-covalent interaction, and is not particularly limited as long as it is linear, and any molecule including a polymer may be used. Here, "linear" of the "linear molecule" means substantially "linear". That is, it is sufficient that the cyclic molecule as a rotor can rotate, or the cyclic molecule can slide or move on the linear molecule, and the linear molecule may have a branched chain. Further, the length of the "linear" only needs to be such that the cyclic molecule can slide or move on the linear molecule, and there is no particular limitation on the length.

[0014] As linear molecules, polymers known as linear molecules constituting a polyrotaxane structure can be used. Both hydrophilic and hydrophobic polymers can be used as linear molecules. Examples of hydrophilic polymers include polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, cellulosic resins (carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, etc.), polyacrylamide, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch, and copolymers thereof. Examples of hydrophobic polymers include polyolefin resins such as polyethylene, polypropylene, and copolymers of olefin monomers; polyester resins; polyvinyl chloride resins; polystyrene resins such as polystyrene and acrylonitrile-styrene copolymers; acrylic resins such as polymethyl methacrylate, (meth)acrylic acid ester copolymers, and acrylonitrile-methyl acrylate copolymers; polycarbonate resins; polyurethane resins; vinyl chloride-vinyl acetate copolymers; polyvinyl butyral resins; and derivatives or modified versions thereof. In addition to these, polyisobutylene, polytetrahydrofuran, polyaniline, acrylonitrile-butadiene-styrene copolymer (ABS resin), polyamides such as nylon, polyimides, polyisoprene, polydienes such as polybutadiene, polysiloxanes such as polydimethylsiloxane, polysulfones, polyimines, polyanhydride, polyurea, polysulfide, polyphosphazene, polyketone, polyphenylene, polyhaloolefin, and derivatives thereof can also be used.

[0015] Of these, polyethylene glycol, polyisoprene, polyisobutylene, polybutadiene, polypropylene glycol, polytetrahydrofuran, polydimethylsiloxane, polyethylene, and polypropylene are preferred as linear molecules. Polyethylene glycol is particularly preferred.

[0016] The number average molecular weight of the linear molecule is preferably 1,000 or more, for example, 1,000 to 1,000,000. More preferably, it is 5,000 or more, for example, 5,000 to 1,000,000 or 5,000 to 500,000, and even more preferably 10,000 or more, for example, 10,000 to 1,000,000, 10,000 to 500,000 or 10,000 to 300,000. In this specification, when the linear molecule is a polyol such as polyethylene glycol, the number average molecular weight of the linear molecule is a value calculated based on the measured value of the hydroxyl value. When the linear molecule is a polyolefin, polyene, organopolysiloxane, etc., it is a value measured by gel permeation chromatography (GPC), and it is a value converted by a standard substance selected according to the type of the linear molecule. For example, when the linear molecule is a polyolefin or polyene, it is a conversion value by standard polyethylene, standard polypropylene, standard polybutadiene, etc., and when the linear molecule is an organopolysiloxane, it is a conversion value with polystyrene as the standard substance.

[0017] <Cyclic molecule> As the cyclic molecule constituting the polyrotaxane structure, a cyclic molecule known as a cyclic molecule constituting the polyrotaxane structure can be used. For example, it may be a cyclic molecule having a hydroxyl group directly bonded to an atom constituting the ring. Specific examples include various cyclodextrins. Examples of cyclodextrins include unmodified cyclodextrins such as α-cyclodextrin, β-cyclodextrin or γ-cyclodextrin; and modified cyclodextrins in which these hydroxyl groups are partially modified. Examples of the modified cyclodextrin include dimethyl cyclodextrin, hydroxypropyl cyclodextrin, hydroxyethyl cyclodextrin, acetyl cyclodextrin, and the like.

[0018] The size of the opening of the cyclic molecule varies depending on the type of cyclodextrin. For example, the type of cyclic molecule can be selected according to the type of linear molecule used. Specifically, the linear molecule used can be considered as cylindrical, and a cyclic molecule capable of encapsulating the linear molecule can be selected according to the diameter of the cylinder's cross-section and the hydrophobicity or hydrophilicity of the linear molecule. Furthermore, if a cyclic molecule with a relatively large opening and a cylindrical linear molecule with a relatively small diameter are used, two or more linear molecules can be encapsulated in the opening of the cyclic molecule.

[0019] <Blocking Groups> The locking groups constituting the polyrotaxane structure are not particularly limited, and any group may be used as long as they maintain the form in which the cyclic molecule is impaled by linear molecules. Examples of such groups include groups having "bulkiness" and / or groups having "ionicity". In this specification, "group" refers to various groups, including groups consisting of atomic groups without repeating units and groups consisting of polymers having repeating units (polymer chains) (polymer groups). The group having "bulkiness" may schematically be a group represented as a sphere, or it may be a solid support represented as a side wall. Furthermore, the "ionicity" of the group having "ionicity" and the "ionicity" of the cyclic molecule may interact with each other, for example by repelling each other, thereby maintaining the form in which the cyclic molecule is impaled by linear molecules.

[0020] As chelating groups, groups known as chelating groups for polyrotaxane structures can be used. Specific examples include dinitrophenyl groups such as 2,4-dinitrophenyl and 3,5-dinitrophenyl; groups having a cyclodextrin skeleton; groups having an adamantane skeleton; trityl groups; groups having a fluorescein skeleton; groups having a pyrene skeleton; and derivatives or modified forms thereof. For example, when α-cyclodextrin is used as the cyclic molecule and polyethylene glycol is used as the linear molecule, chelating groups can include groups having a cyclodextrin skeleton; dinitrophenyl groups such as 2,4-dinitrophenyl and 3,5-dinitrophenyl; groups having an adamantane skeleton; trityl groups; groups having a fluorescein skeleton; groups having a pyrene skeleton; and derivatives or modified forms thereof.

[0021] Furthermore, if the chokeholding group is a polymer group having repeating units, it is sufficient that it maintains a skewer-like structure, and the main chain of the polymer group may be bonded to the ends of the linear molecules, or the side chains of the polymer may be bonded to the linear molecules.

[0022] [Preferred Embodiments of Polyrotaxane Structure] Preferred embodiments of the cyclic molecule, linear molecule, and choke group constituting the polyrotaxane structure include a configuration in which the cyclic molecule is a cyclodextrin, the linear molecule is polyethylene glycol, and the choke group is a group having an adamantane structure or a dinitrophenyl group. α-cyclodextrin is particularly preferred among the cyclodextrins. <Group X> In the polyrotaxane of this embodiment, some or all of the cyclic molecules constituting the polyrotaxane structure have a polysiloxane chain and a group X having a crosslinking group. That is, some or all of the cyclic molecule is modified with group X. For example, the cyclic molecule may have a hydroxyl group directly bonded to an atom constituting the ring, and at least some of the hydrogen atoms of the hydroxyl group are substituted with group X. That is, the atom constituting the ring may have a group X (-OX) bonded to it via a linking group (-O-) obtained by removing a hydrogen atom from the hydroxyl group.

[0023] In group X, the polysiloxane chain has a main chain consisting of siloxane bonds. The main chain may be linear or branched. The main chain consists of at least two silicon atoms, preferably three or more, and more preferably four or more. There is no particular upper limit, but for example, it may be 200 or less, or 1000 or less. Substituents (side chains) may be attached to the silicon atoms that make up the main chain. Examples of substituents include methyl groups, phenyl groups, vinyl groups, allyl groups, and hydride groups. Methyl groups are more preferred. The substituents attached to the silicon atoms in the main chain of the polysiloxane chain may be one type or two or more types. In this specification, a unit having one silicon-oxygen bond that makes up the main chain of the polysiloxane chain is called a siloxane unit. The siloxane units that make up the polysiloxane chain may be one type or two or more types.

[0024] Examples of crosslinkable groups of group X include alkenyl groups, hydrosilyl groups, mercaptoalkyl groups, mercapto groups, methoxy groups, ethoxy groups, and acetyl groups. Preferably, the crosslinkable group is an alkenyl group, a hydrosilyl group, or a mercaptoalkyl group. Examples of alkenyl groups include vinyl groups, allyl groups, propenyl groups, isopropenyl groups, 2-methyl-1-propenyl groups, 2-methylallyl groups, and 2-butenyl groups, as well as alkenylalkyl groups. Vinyl groups are particularly preferred. Examples of mercaptoalkyl groups include mercaptoethyl groups, mercaptopropyl groups, and mercaptobutyl groups. The mercapto group constituting the mercaptoalkyl group is preferably bonded to the end of the alkyl group, and 2-mercaptopropyl groups are particularly preferred. From the viewpoint of crosslinking reactivity, the bond position of the crosslinkable group in group X is preferably at the end of the polysiloxane chain.

[0025] [Linking Group] In group X, a linking group may exist between the terminal of the polysiloxane chain and the crosslinking group. The linking group may be a divalent group formed by the reaction of the terminal group of the polysiloxane chain with the compound used to introduce the crosslinking group (for example, compound C and compound D described later). The linking group may include a carbon chain. The carbon chain may have an etheric oxygen atom (-O-) between the carbon-carbon bonds. The carbon chain may be linear or branched. The carbon chain may be, for example, an ethylene glycol unit (-CH₂). ２ CH ２ Examples include polyethylene glycol chains having two or more -O- atoms. Preferably, the chain length of the carbon chain is within a range that does not impede the compatibility of the polyrotaxane in the curable composition described later.

[0026] <Group Y> In the polyrotaxane of this embodiment, the cyclic molecule may have groups X and Y. Group Y is a group that does not contain a polysiloxane chain and has a crosslinking group. Examples of the crosslinking group of group Y are the same as the crosslinking group of group X. The crosslinking group of group X and the crosslinking group of group Y present in one molecule of polyrotaxane may be the same or different. It is preferable that they be the same. For example, the cyclic molecule may have a hydroxyl group directly bonded to an atom constituting the ring, with some of the hydrogen atoms of the hydroxyl group being substituted by group X, and at least some of the hydrogen atoms of the remaining hydroxyl group being substituted by group Y. That is, it may have a group X (-OX) bonded to an atom constituting the ring via -O-, and further have a group Y (-OY) bonded to another atom constituting the ring via -O-.

[0027] [Linking Group] In group Y, a linking group may exist between the cyclic molecule and the crosslinking group. The linking group may be, for example, a divalent group formed by the reaction of the hydroxyl group of the cyclic molecule with the compound used to introduce the crosslinking group (for example, compound C and compound D described later). Specific examples of linking groups include those similar to the linking group in group X. The linking group of group X and the linking group of group Y in one molecule of polyrotaxane may be the same.

[0028] <Group Z> In the polyrotaxane of this embodiment, the cyclic molecule may have groups X and Z, or the cyclic molecule may have groups X, Y and Z. Group Z is a group that does not contain a polysiloxane chain or a crosslinking group, but has a non-crosslinking group. For example, the cyclic molecule may have a hydroxyl group directly bonded to an atom constituting the ring, some of the hydrogen atoms of the hydroxyl group are substituted with group X, and some of the hydrogen atoms of the other hydroxyl groups are substituted with group Z. That is, it may have a group X (-OX) bonded to an atom constituting the ring via -O-, and further have a group Z (-OZ) bonded to another atom constituting the ring via -O-. Alternatively, it may have the -OX and -OZ, and further have a group Y (-OY) bonded to another atom constituting the ring via -O-.

[0029] In the curable composition described later, group Z is preferably a group that improves the compatibility between the polyrotaxane of this embodiment and the organopolysiloxane described later. From the viewpoint of compatibility with organopolysiloxane, group Z is preferably hydrophobic. For example, group Z is preferably a monovalent group (RC(O)-, where R is a hydrocarbon group having 2 to 17 carbon atoms) obtained by removing the -OH group from a C1 to C18 carboxylic acid.

[0030] [Inclusion Rate] In polyrotaxanes, it is preferable that at least two cyclic molecules are pierced by linear molecules in a skewer-like manner. That is, it is preferable that there are two or more cyclic molecules that encapsulate linear molecules. In the polyrotaxane structure, the amount of cyclic molecules pierced by linear molecules in a skewer-like manner can be controlled when forming the pseudo-polyrotaxane structure. When the maximum number of cyclic molecules that can exist on the linear molecules is defined as the maximum inclusion amount, the inclusion rate, which represents the ratio of the number of cyclic molecules to the maximum inclusion amount, is preferably 0.1 to 60%, more preferably 1 to 50%, and even more preferably 5 to 40%. For example, when the linear molecule is polyethylene glycol and the cyclic molecule is cyclodextrin, the maximum inclusion amount (inclusion rate of 100%) is when there is one cyclic molecule for every two repeating units (ethylene glycol units) of the linear molecule. If there is one cyclodextrin for every eight ethylene glycol units, the inclusion rate is 25%. The inclusion rate of polyrotaxanes １ This can be determined by 1H-NMR analysis. Specifically, it can be calculated by comparing the integral value of the signal originating from the cyclic molecule with the integral value of the signal originating from the repeating unit of the linear molecule in the NMR spectrum.

[0031] The molecular weight of the polyrotaxane corresponds to the total molecular weight of one linear molecule, the sealing groups at both ends of that molecule, and the cyclic molecule (containing at least group X) enclosing the linear molecule. The average molecular weight of the polyrotaxane is preferably 1,900 to 7,700,000, more preferably 6,000 to 3,820,000, and particularly preferably 10,000 to 300,000. In this specification, the average molecular weight of the polyrotaxane is determined by GPC measurement, and １ It can be measured by H-NMR.

[0032] In polyrotaxanes, the number of groups X per polyrotaxane molecule is preferably 1 to 200,000, more preferably 2 to 10,000, and particularly preferably 2 to 1,000. If the number is above the lower limit of the above range, the compatibility with organopolysiloxanes is better, and if it is below the upper limit, it becomes easier to design the flexibility (complex modulus) and extensibility of the cured organopolysiloxane composition within a desirable range.

[0033] In polyrotaxanes, the number of silicon atoms present in group X (hereinafter also referred to as "silicon atoms of group X") is preferably 1 to 2,000 on average per cyclic molecule, and more preferably 200 to 500. If the average number of silicon atoms of group X per cyclic molecule is above the lower limit of the above range, the compatibility with organopolysiloxanes is improved, and if it is below the upper limit, it becomes easier to design the flexibility (complex modulus) and extensibility of the cured organopolysiloxane composition within a desirable range.

[0034] ≪Method for Producing Polyrotaxane≫ In the method for producing polyrotaxane according to this embodiment, compound A is used, which has one or more cyclic molecules, linear molecules, and sealing groups located at both ends of the linear molecules, wherein the cyclic molecules enclose the linear molecules that penetrate through their openings, and the cyclic molecules have hydroxyl groups. The hydroxyl groups of the cyclic molecules of compound A are modified with a group X having a polysiloxane chain and a crosslinking group to produce a polyrotaxane. According to this method, a polyrotaxane is obtained in which the cyclic molecules have hydroxyl groups, and at least some of the hydrogen atoms of the hydroxyl groups are substituted with the group X.

[0035] Compound A can be produced by forming a pseudopolyrotaxane structure in step 1 below and a polyrotaxane structure in step 2 below. (Step 1) A step of mixing a cyclic molecule having a hydroxyl group and a linear molecule, and piercing the opening of the cyclic molecule with the linear molecule in a skewer-like manner to form a pseudopolyrotaxane structure. (Step 2) A step of sealing both ends of the pseudopolyrotaxane structure obtained in step 1 (both ends of the linear molecule) with a sealing group so that the cyclic molecule does not detach from the skewer-like state, thereby obtaining a polyrotaxane (compound A) in which the cyclic molecule has a hydroxyl group. Step 1 can be carried out by known methods. Step 2 can be carried out by known methods.

[0036] Step 1 uses a cyclic molecule having a hydroxyl group (preferably a cyclodextrin). In the pseudopolyrotaxane structure obtained in Step 1, it is preferable that reactive groups are present at both ends of the linear molecule. The reactive groups can be any group that can react with the compound that forms the sealing group, such as a hydroxyl group, an amino group, a carboxyl group, or a thiol group. In Step 2, by reacting the reactive groups at both ends of the linear molecule with the compound that forms the sealing group, sealing groups can be introduced at both ends of the linear molecule to form a polyrotaxane structure. Examples of compounds that form the sealing group include 2,4-dinitrofluorobenzene and adamantylacetic acid.

[0037] The step of modifying the hydroxyl group of the cyclic molecule of compound A with group X can be carried out by introducing a polysiloxane chain in step 3 below and introducing a crosslinking group in step 4 below. (Step 3) A step of dissolving compound A in an organic solvent and adding a cyclic siloxane to at least a portion of the hydroxyl group of the cyclic molecule of compound A by ring-opening addition to form a polysiloxane chain having a hydroxyl group at the end to obtain compound B. (Step 4) A step of introducing a crosslinking group to at least a portion of the end of the polysiloxane chain of compound B obtained in step 3.

[0038] Step 4 can be carried out by the method of Step 4-1 or Step 4-2 below. (Step 4-1) A step of reacting compound C, which has a crosslinking group and reacts with a hydroxyl group, with compound B to introduce the crosslinking group to at least a portion of the terminal end of the polysiloxane chain. (Step 4-2) A step of reacting compound D, which has a halogen group and reacts with a hydroxyl group, with compound B to introduce the halogen group to at least a portion of the terminal end of the polysiloxane chain, and then substituting the halogen group with a mercapto group.

[0039] <Step 3> In Step 3, compound A, in which the cyclic molecule has a hydroxyl group, is dissolved in an organic solvent, and a cyclic siloxane is added to at least a portion of the hydroxyl group of the cyclic molecule by ring-opening addition to form a polysiloxane chain having a hydroxyl group at the terminal, thereby obtaining compound B.

[0040] [Cyclic Siloxanes] Cyclic siloxanes with three or four silicon atoms are preferred. Specific examples include hexamethylcyclotrisiloxane (C6DMS), octamethylcyclotetrasiloxane, 2,4,6-trimethyl-2,4,6-trivinylcyclotrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, 2,4,6-trimethyl-2,4,6-triphenylcyclooctanetrisiloxane, 2,4,6,8-tetramethyl-2,4,6,8-tetraphenylcyclooctanetetrasiloxane, and 2,4,6,8-tetramethylcyclotetrasiloxane. More preferably, hexamethylcyclotrisiloxane (C6DMS) is preferred.

[0041] [Catalyst] Basic catalysts are used in ring-opening addition reactions of cyclic siloxanes. Examples of basic catalysts include amidine-type bases or guanidine-type bases such as 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene, and 1,5,7-triazabicyclo[4.4.0]deca-5-ene, with 1,8-diazabicyclo[5.4.0]-7-undecene and 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene being preferred.

[0042] [Organic Solvents] In the reaction of ring-opening addition of a cyclic siloxane, a combination of a first organic solvent that dissolves compound A having a polyrotaxane structure and a second organic solvent that can dissolve the cyclic siloxane and is compatible with the first organic solvent is preferred. Examples of the first organic solvent include dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and N-ethylpyrrolidone. Examples of the second organic solvent include chloroform, tetrahydrofuran, and methylene chloride. Preferred combinations of the first and second organic solvents include a combination of dimethyl sulfoxide and chloroform, and a combination of N-methylpyrrolidone and tetrahydrofuran.

[0043] <Step 4-1> In Step 4-1, compound C, which has a crosslinking group and reacts with a hydroxyl group, is reacted with compound B obtained in Step 3 to introduce a crosslinking group to at least a portion of the terminal end of the polysiloxane chain, thereby forming group X.

[0044] [Compound C] Compound C has a reactive group that can react with the hydroxyl group at the end of the polysiloxane chain and a crosslinking group. Examples of reactive groups that can react with the hydroxyl group include halogen groups, imino groups (-NH-), and hydrosilyl groups (-SiH). Examples of crosslinking groups include alkenyl groups, hydrosilyl groups (-SiH), mercaptoalkyl groups (thiol groups), methoxy groups, ethoxy groups, and acetyl groups. Preferred compound C includes silane compounds, silazane compounds, and siloxane compounds such as compounds C1 to C4 below. Furthermore, if a compound having a carbon chain between the reactive group and the crosslinking group is used as compound C, such as compound C5 below, a group X can be formed in which a linking group containing the carbon chain exists between the end of the polysiloxane chain and the crosslinking group. The carbon chain may have an etheric oxygen atom (-O-) between the carbon-carbon bonds. Furthermore, compounds that do not contain Si atoms, such as compounds C6 and C7 below, may be used as compound C.

[0045] Compound (C1): A silane or silazane compound in which the reactive group is a halogen group and the crosslinking group is an alkenyl group or a hydrosilyl group. Specific examples include chlorodimethylvinylsilane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, and chlorodimethylsilane. Preferably, chlorodimethylvinylsilane or chlorodimethylsilane. Compound (C2): A silazane compound in which the reactive group is an imino group and the crosslinking group is a hydrosilyl group (-SiH). Specific examples include 1,1,3,3-tetramethyldisilazane. Compound (C3): A siloxane compound in which the reactive group is a hydrosilyl group and the crosslinking group is a hydrosilyl group. Specific examples include 1,1,3,3-tetramethyldisiloxane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, 1,1,3,3,5,5,7,7,9,9,11,11-dodecamethylhexasiloxane, and 1,1,3,3,5,5,7,7,9,9,11,11,13,13-tetradecamethylheptasiloxane. Compound (C4): A silane compound in which the reactive group is a halogen group and the crosslinking group is a mercaptoalkyl group (thiol group). Specific examples include mercaptoalkylhalogenated silanes such as 3-mercaptopropyldimethylchlorosilane and 3-mercaptomethyldimethylchlorosilane. Compound (C5): A compound having a linear or branched carbon chain, such as polyethylene glycol chains, with a reactive group at one end that reacts with the hydroxyl group at the end of the polysiloxane chain, and one or more crosslinking groups at the other ends. Examples of reactive groups include dimethylchlorosilyl and dimethylsilyl groups. Examples of crosslinking groups include dimethylvinylsilyl and dimethylsilyl groups. Compound (C6): A compound in which the reactive group is a halogen group and the crosslinking group is an acetyl group. Specific examples include acetyl chloride and acetic anhydride. Compound (C7): A compound in which the reactive group is a halogen group and the crosslinking group is a methoxy or ethoxy group. Specific examples include chloro(methoxy)dimethylsilane and chloro(ethoxy)dimethylsilane.

[0046] <Step 4-2> In Step 4-2, compound D, which has a halogen group and reacts with a hydroxyl group, is reacted with compound B obtained in Step 3 to introduce a halogen group to at least a portion of the terminal end of the polysiloxane chain. Then, the halogen group is replaced with a mercapto group to form a crosslinkable mercaptoalkyl group (thiol group) or mercapto group, thereby forming group X.

[0047] [Compound D] Compound D includes silane and silazane compounds having a reactive group that can react with the terminal hydroxyl group of a polysiloxane chain and a halogen group. Examples of reactive groups include halogen groups and hydrosilyl groups (-SiH). Specific examples of compound D include chloro(chloromethyl)dimethylsilane, chlorodimethylsilane, (bromomethyl)chlorodimethylsilane, and 1,3-bis(chloromethyl)tetramethyldisilazane, with chloro(chloromethyl)dimethylsilane and chlorodimethylsilane being preferred.

[0048] Methods for forming a mercaptoalkyl group (thiol group) or mercapto group by substituting a halogen group introduced at the end of a polysiloxane chain with a mercapto group include substitution reactions with NaSH, substitution reactions using thiourea and amine, substitution reactions using sodium thioacetate followed by a reduction reaction using lithium aluminum hydride, and so on.

[0049] <Introduction of group Y> In step 4-1, compound C may react with the hydroxyl group of the cyclic molecule to introduce a crosslinking group to the cyclic molecule, thereby forming group Y which does not contain a polysiloxane chain and has a crosslinking group. Compound C6 or C7 may be used as compound C for forming group Y. Alternatively, in step 4-2, compound D may react with the hydroxyl group of the cyclic molecule to introduce a halogen group to the cyclic molecule, and the halogen group may be replaced by a mercapto group to form group Y. For example, in step 3, a polysiloxane chain may be introduced to some of the hydroxyl groups of the cyclic molecule of compound A to obtain compound B, and then in step 4-1, group Y may be introduced to the cyclic molecule by reacting with compound C in excess of the total number of hydroxyl groups of compound C and the hydroxyl groups at the ends of the polysiloxane chain. For example, it is preferable that the number of reacting groups be 5 to 20 equivalents of the total number of hydroxyl groups. For example, in step 3, compound B is obtained by introducing a polysiloxane chain to some of the hydroxyl groups of the cyclic molecule of compound A. Then, in step 4-2, group Y may be introduced to the cyclic molecule by reacting with compound D in an excess amount relative to the total number of hydroxyl groups of the remaining hydroxyl groups of the cyclic molecule of compound B and the hydroxyl groups at the ends of the polysiloxane chain. For example, it is preferable that the number of reacting groups be 5 to 20 times the equivalent amount of the total number of hydroxyl groups.

[0050] <Introduction of Group Z> The step of introducing a group Z, which does not contain a polysiloxane chain or a crosslinking group but has a non-crosslinking group, into a cyclic molecule can be carried out using a compound Z that has a reactive group that can react with the hydroxyl group of the cyclic molecule and a non-crosslinking group. Examples of reactive groups include halogen groups, imino groups (-NH-), and hydrosilyl groups (-SiH). Examples of non-crosslinking groups include monovalent groups obtained by removing -OH from C1 to C18 carboxylic acids. Compound Z is preferably a silane compound. For example, in step 3, a polysiloxane chain may be introduced to a portion of the hydroxyl group of the cyclic molecule of compound A to obtain compound B, and then in step 4, a group Y may be introduced to a portion of the remaining hydroxyl group of the cyclic molecule of compound B, and then the hydroxyl group of the remaining cyclic molecule may be reacted with the reactive group of compound Z to introduce group Z into the cyclic molecule. When reacting the hydroxyl groups of the cyclic molecule with the reactive groups of compound Z, it is preferable that the number of reactive groups of compound Z be 1.5 to 2 times the equivalent amount of the number of hydroxyl groups of the cyclic molecule.

[0051] Furthermore, a non-crosslinkable group (group Z), which is a monovalent group obtained by removing the -OH group from a C1-C18 carboxylic acid, can be introduced into the cyclic molecule by esterification reaction with the hydroxyl group of the cyclic molecule. Examples include a method using a carboxylic acid chloride and a base corresponding to the desired non-crosslinkable group, a method using the corresponding carboxylic acid and a condensing agent such as dicyclohexylcarbodiimide, and a mixed acid anhydride method using the corresponding carboxylic acid, sulfonyl chloride, and a base. In particular, the method using the corresponding carboxylic acid chloride and a base is preferred.

[0052] <Reaction By-product Trap Agent> In the production process of polyrotaxanes, when a dehalogenation reaction is carried out, it is preferable to add a trap agent (reaction by-product trap agent) to neutralize the hydrogen halides produced as by-products. Preferred reaction by-product trap agents include nitrogen-containing heterocyclic compounds such as pyridine, 2-picoline, 2,6-lutidine, and N,N-dimethylaminopyridine; and tertiary alkylamines such as triethylamine and diisopropylethylamine, with pyridine and triethylamine being more preferred.

[0053] <Purification Step> It is preferable to perform a purification step after the reaction step to obtain the target polyrotaxane. The purification step can be carried out using known methods. For example, the solvent in the reaction solution can be removed by vacuum distillation, water can be added to precipitate the target compound, the precipitate can be washed with methanol, and then the solvent can be removed by vacuum distillation. Other purification methods include separating the target compound by decantation and then purifying it by column chromatography, or preparative purification by gel filtration chromatography.

[0054] Preferred embodiments of the method for producing polyrotaxane include, for example, the following embodiments 1 and 2. <Embodiment 1> As a specific example of [Steps 1 and 2], compound A can be synthesized by a similar synthesis method to the method for synthesizing blocked polyrotaxane in Example 1 of International Publication No. 2001 / 083566, using (2-hydroxypropyl)-α-cyclodextrin instead of α-cyclodextrin for the cyclic molecule. Here, the inclusion rate of the polyrotaxane can be adjusted by the mixing ratio of linear molecules and cyclic molecules. As [Step 3], compound A obtained in Step 2 is added to dehydrated N-methylpyrrolidone under a nitrogen atmosphere and heated until dissolved. Then, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene is added as a catalyst and stirred. Furthermore, a monomer solution of hexamethylcyclotrisiloxane dissolved in THF is added in part and reacted, and then cooled to obtain a solution of compound B. In step 4, pyridine is added to the solution of compound B as a reaction by-product trapping agent, chlorodimethylvinylsilane is added as compound C and stirred, then the solvent is removed by vacuum distillation, water is added and the precipitate is collected, methanol is added and decanted, and then purified by column chromatography to obtain a polyrotaxane into which a polydimethylsiloxy group with a vinyl group at the end is introduced as group X and a dimethylvinylsilyl group is introduced as group Y.

[0055] <Aspect 2> After obtaining a solution of compound B by carrying out [Steps 1, 2] and [Step 3] in the same manner as in Aspect 1, in [Step 4], pyridine and chlorodimethylvinylsilane are added to the solution of compound B, stirred, then recooled, pyridine and acetyl chloride are added, stirred, then the solvent etc. is removed by vacuum distillation, water is added and the precipitate is collected, methanol is added and decanted, and then purified by column chromatography to obtain a polyrotaxane into which a polydimethylsiloxy group having a vinyl group at the end as group X, a dimethylvinylsilyl group as group Y, and an acetyl group as group Z are introduced.

[0056] <<Curable Composition>> The curable composition of this embodiment contains the polyrotaxane of the above embodiment (hereinafter also referred to as "polyrotaxane (R)") and an organopolysiloxane having crosslinkable groups. Preferably, the organopolysiloxane has at least two crosslinkable groups in one molecule. A cured product can be formed by a crosslinking reaction between the crosslinkable groups present in the organopolysiloxane and the crosslinkable groups present in the polyrotaxane (R). The curable composition may contain reaction-promoting components that accelerate the crosslinking reaction, and may also contain functional fillers that add functionality to the cured product. Furthermore, it may contain other optional components as long as they do not impair the effects of the present invention.

[0057] <Organopolysiloxanes with Crosslinkable Groups> The crosslinkable group of the organopolysiloxane is selected according to the type of crosslinkable group present in the polyrotaxane (R). For example, if the crosslinkable group of the polyrotaxane (R) is an alkenyl group, the crosslinkable group of the organopolysiloxane is preferably a hydrosilyl group, a mercaptoalkyl group, or a mercapto group. If the crosslinkable group of the polyrotaxane (R) is a hydrosilyl group, a mercaptoalkyl group, or a mercapto group, the crosslinkable group of the organopolysiloxane is preferably an alkenyl group. The organopolysiloxane may contain one type of crosslinkable group or two or more types.

[0058] [Organopolysiloxane with a crosslinkable group being an alkenyl group] An organopolysiloxane in which the crosslinkable group is an alkenyl group (hereinafter also referred to as "alkenyl group-containing organopolysiloxane") is preferably a polymer (1) represented by the following average composition formula (1). Polymer (1) contains at least two alkenyl groups bonded to silicon atoms in one molecule. The molecular structure of polymer (1) is not particularly limited and may be linear, branched, cyclic or three-dimensional network. Also, polymer (1) may be a polymer composed of a single siloxane unit or a copolymer composed of two or more siloxane units. R １ ａ R ２ ｂ SiO （４－ａ－ｂ）／２ ・・・(1) In formula (1), R １ is an unsubstituted or substituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond. In formula (1), R １ is an alkenyl group, a is 0.96 to 2.00, b is 0.001 to 0.5, and a + b = 1.00 to 2.04. In formula (1), preferably, a is 1.80 to 2.00, b is 0.001 to 0.1, and a + b is 1.90 to 2.04.

[0059] The monovalent hydrocarbon group represented by R １ in the above formula includes alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, hexyl group, octyl group, dodecyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group; aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl groups such as benzyl group, phenylethyl group, phenylpropyl group; or substituted hydrocarbon groups in which some or all of the hydrogen atoms of these hydrocarbon groups are substituted with fluorine atoms, chlorine atoms, nitrile groups, etc., for example, trifluoropropyl group, chloromethyl group, cyanoethyl group, etc. are exemplified.

[0060] The plurality of R １These groups may be identical or different from each other, but it is preferable that they are all methyl groups for the sake of chemical stability and ease of synthesis. If necessary for the properties, some of the methyl groups may be substituted with phenyl groups or trifluoropropyl groups, etc. For example, from the viewpoint of improving cold resistance, it is preferable to substitute some of the methyl groups with phenyl groups. The content of phenyl groups bonded to silicon atoms in the polysiloxane chain is preferably 15 mol% or less, and more preferably 10 mol% or less, relative to the total amount of monovalent organic groups (unsubstituted or substituted monovalent hydrocarbon groups) bonded to silicon atoms in polymer (1). Furthermore, from the viewpoint of flexibility under low temperature conditions, it is preferable that the above-mentioned phenyl groups are bonded to silicon atoms of D units (SiO units).

[0061] R in polymer (1) ２ Examples of alkenyl groups represented by R include vinyl, allyl, isopropenyl, butenyl, and pentenyl groups. ２ The alkenyl group is preferably a vinyl group or an allyl group, with the vinyl group being the most preferred in terms of ease of synthesis and chemical stability. This alkenyl group may be bonded to a silicon atom at the end of the molecular chain, to a silicon atom at the non-terminus (middle of the molecular chain), or to both. A diorganopolysiloxane containing alkenyl groups bonded to at least two silicon atoms at the ends of the molecular chain is preferred as polymer (1).

[0062] In the curable composition, the alkenyl group-containing organopolysiloxane may be used individually or in combination of two or more types. The length of the siloxane main chain of the alkenyl group-containing organopolysiloxane is appropriately selected according to the desired crosslinking structure.

[0063] [Organopolysiloxanes with hydrosilyl crosslinking groups] Organopolysiloxanes with hydrosilyl crosslinking groups (hereinafter also referred to as "organohydrogenpolysiloxanes") preferably contain at least two (usually 2 to 200), more preferably three or more (for example, about 3 to 150) hydrogen atoms bonded to silicon atoms (i.e., SiH groups) in the molecule, and are preferably organohydrogenpolysiloxanes (2) represented by the average composition formula of the following formula (2). R ３ ｃ H ｄ SiO （４－ｃ－ｄ）／２ ...(2) In formula (2), R ３ is an unsubstituted or substituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, c is 0.70 to 2.0, d is 0.01 to 1.2, and c + d = 0.8 to 3.0. In formula (2), preferably c is 1.0 to 2.0, d is 0.01 to 1.0, and c + d is 1.1 to 2.2.

[0064] R in equation (2) above ３ The unsubstituted or substituted monovalent hydrocarbon group represented by the above R is １ Similar examples are given. Multiple R present in organohydrogenpolysiloxane (2) ３ These groups may be identical or different from each other, but it is preferable that they are all methyl groups for ease of synthesis and chemical stability. If necessary for specific properties, some of the methyl groups may be substituted with phenyl or trifluoropropyl groups.

[0065] The molecular structure of organohydrogenpolysiloxane (2) is not particularly limited and may be linear, branched, cyclic, or three-dimensional network. A polymer consisting only of siloxane units having silicon-hydrogen bonds, or a polymer consisting of triorganosiloxy units, diorganosiloxy units, monoorganosiloxy units and SiO ２ The molecule may be a copolymer of one or more units selected from the available units. Furthermore, there are no particular restrictions on the position of the SiH group in the molecule; it may be located at the end of the molecular chain, at the non-terminus of the molecular chain (midway through the chain), or at both.

[0066] In the curable composition, the organohydrogenpolysiloxane may be used alone or in combination of two or more types. The length of the siloxane main chain of the organohydrogenpolysiloxane is appropriately selected according to the desired crosslinking structure.

[0067] [Organopolysiloxanes with thiol groups as crosslinkable groups] Organopolysiloxanes with thiol groups as crosslinkable groups (hereinafter also referred to as "thiol group-containing organopolysiloxanes") are preferably polymers (3) having at least two siloxane units in the molecule that contain a mercaptoalkyl group bonded to a silicon atom represented by the following formula (3). In polymer (3), there may be one type of siloxane unit represented by formula (3), or two or more types may be used in combination. ４ ｒ R ５ ｓ SiO （４－ｒ－ｓ）／２ ...(3) In formula (3), R ４ R is an unsubstituted or substituted monovalent hydrocarbon group that does not have an aliphatic unsaturated bond. ５ is a mercaptoalkyl group having 1 to 6 carbon atoms, r is an integer from 0 to 2, s is an integer from 1 to 3, and r+s is 1 to 3.

[0068] In polymer (3), in order to ensure a stable structure through the crosslinking reaction while suppressing excessive curing shrinkage, the number of mercaptoalkyl groups bonded to silicon atoms is preferably 2 to 20 per molecule, more preferably 3 to 10, and even more preferably 3 to 7. The molecular structure of polymer (3) is not particularly limited as long as the siloxane bond is the main backbone, and may be linear, branched, cyclic, or three-dimensional network, and the siloxane backbone may be interrupted by divalent organic groups. It may also have hydroxyl groups or alkoxy groups such as methoxy or ethoxy groups bonded to silicon atoms.

[0069] R in the above formula ４Examples include alkyl groups, such as C1-C6 alkyl groups (e.g., methyl, ethyl, propyl, etc.); cycloalkyl groups, such as C3-C10 cycloalkyl groups (e.g., cyclohexyl, etc.); aryl groups, such as C6-C20 aryl groups (e.g., phenyl, tolyl, xylyl, naphthyl, anthracenyl, etc.); aralkyl groups, such as C7-C13 aralkyl groups (e.g., 2-phenylethyl, 2-phenylpropyl, etc.); and substituted hydrocarbon groups, such as halogen-substituted hydrocarbon groups (e.g., chloromethyl, chlorophenyl, 3,3,3-trifluoropropyl, etc.). Alkyl groups are preferred from the viewpoint of ease of synthesis, and among them, methyl, ethyl, and propyl groups are preferred, with methyl being more preferred. Aryl groups can be used in combination to adjust the refractive index, and among them, phenyl groups are preferred from the viewpoint of ease of synthesis.

[0070] R in the above formula ５ Examples include mercaptomethyl, 2-mercaptoethyl, 3-mercaptopropyl, 4-mercaptobutyl, and 6-mercaptohexyl. Mercaptomethyl and 3-mercaptopropyl are preferred, and 3-mercaptopropyl is more preferred, due to their ease of synthesis.

[0071] From the viewpoint of crosslinking reactivity, thiol group-containing organopolysiloxanes have at least two R groups in one molecule. ５１ SiO ３／２ Unit (in the formula, R) ５１ Preferably, the molecule contains a polyorganosiloxane having a mercaptoalkyl group with 1 to 6 carbon atoms. In particular, it contains at least two R groups in one molecule. ５１ SiO ３／２ Units, and R ４ ３ SiO １／２ Units and R ４ ２ SiO ２／２ It is more preferable to include units. Thiol group-containing organopolysiloxanes are preferable in terms of workability and crosslinking reactivity, as R is present in one molecule. ５１ SiO ３／２Preferably, the ratio (M:S) of the number of units (referred to as "unit M") to the number of siloxane units that do not contain mercaptoalkyl groups (referred to as "unit S") is 1:60 to 1:5, but is not limited to this.

[0072] [Mixing Ratio] In the curable composition, the mixing ratio of polyrotaxane(R) and organopolysiloxane having a crosslinking group can be adjusted according to the physical properties of the cured product. For example, the content of polyrotaxane(R) is preferably 0.1 to 50% by mass, more preferably 0.1 to 20% by mass or 1 to 50% by mass, and even more preferably 1 to 20% by mass, relative to the total amount of polyrotaxane(R) and organopolysiloxane having a crosslinking group.

[0073] <Aspects of using organopolysiloxanes having crosslinkable groups in combination> The curable composition may also contain two or more organopolysiloxanes that can be crosslinked with each other. For example, the curable composition may contain an organopolysiloxane having a first crosslinkable group, an organopolysiloxane having a second crosslinkable group, and a polyrotaxane (R) having either the first or second crosslinkable group. Examples of crosslinkable group combinations include a combination in which one of the first and second crosslinkable groups is an alkenyl group and the other is a hydrosilyl group, and these are crosslinked by a hydrosilylation reaction; and a combination in which one of the first and second crosslinkable groups is an alkenyl group and the other is a thiol group, and these are crosslinked by an ene-thiol reaction. The "molar ratio of crosslinking groups" is defined as the molar ratio of crosslinking groups present only in the organopolysiloxane to the molar ratio of crosslinking groups present in both the polyrotaxane (R) and the organopolysiloxane. The molar ratio of crosslinking groups is preferably 0.1 to 10, more preferably 0.1 to 8 or 0.5 to 10, and even more preferably 0.5 to 8. If the molar ratio of crosslinking groups is above the lower limit of the above range, the composition is sufficiently crosslinked and has superior shape retention, and if it is below the upper limit, it is superior in that it achieves both flexibility (complex modulus) and high elongation.

[0074] It is preferable that two or more organopolysiloxanes that can crosslink with each other have different numbers of crosslinking groups per molecule (hereinafter also referred to as "number of functional groups") and viscosity (molecular weight). The number of functional groups and viscosity (molecular weight) of the organopolysiloxanes can be appropriately selected according to the physical properties of the desired cured product. For example, if the first organopolysiloxane (S1) has the same crosslinking groups as polyrotaxane (R), and the second organopolysiloxane (S2) has crosslinking groups that crosslink with polyrotaxane (R), then the first organopolysiloxane (S1) may have 2 functional groups, and the second organopolysiloxane (S2) may have an average number of functional groups per molecule of 3.0 or more, 4.0 or more, 5.0 or more, or 6.0 or more. The viscosity at 25°C is preferably 0.1 mm for the first organopolysiloxane (S1). ２ / s or more, more preferably 0.1 to 100,000 mm ２ The ratio is / s, and the second organopolysiloxane (S2) is preferably 100,000 mm ２ Less than / s, more preferably 0.1 to 100,000 mm ２ It may be / s. Here, the viscosity of organopolysiloxanes in this specification is the value measured by a rotational viscometer, and in the case of commercially available products, it is the catalog value.

[0075] <Reaction-Promoting Components> As reaction-promoting components for heating and crosslinking by hydrosilylation reactions, catalysts that promote the addition reaction between alkenyl groups and hydrosilyl groups may be used. From the viewpoint of good catalytic activity, compounds containing platinum group metal atoms such as platinum, rhodium, and palladium are preferably used as catalysts. Specific examples include platinum compounds such as chloroplatinic acid, reaction products of chloroplatinic acid and alcohols, platinum-olefin complexes, platinum-vinylsiloxane complexes, platinum-ketone complexes, and platinum-phosphine complexes; rhodium compounds such as rhodium-phosphine complexes and rhodium-sulfide complexes; and palladium compounds such as palladium-phosphine complexes. Platinum compounds are particularly preferred, and platinum-vinylsiloxane complexes are more preferred. From the viewpoint of ensuring an appropriate curing rate, the amount of these catalysts used is preferably 0.1 to 1000 ppm by mass, and more preferably 0.5 to 200 ppm by mass, relative to the total blending mass of polyrotaxane (R) and organopolysiloxane having a crosslinking group, in terms of platinum group metal atoms.

[0076] A photoactive catalyst may be used as a reaction-promoting component for the heating crosslinking reaction by hydrosilylation. When activated by light such as ultraviolet light, the photoactive catalyst functions as a catalyst that promotes the addition reaction by hydrosilylation. The photoactive catalyst is not particularly limited as long as it is a photoactive catalyst, and known photoactive catalysts used in conventional photoactive thermosetting silicone resin compositions can be applied. Platinum group metal catalysts or nickel-based catalysts are particularly preferred. Platinum group metal catalysts can be platinum-based, palladium-based, or rhodium-based, with platinum-based catalysts being particularly preferred. Examples of platinum-based catalysts include β-diketone platinum complexes or platinum complexes having cyclic diene compounds as ligands.

[0077] Examples of β-diketone platinum complexes include trimethyl(acetylacetonato) platinum complex, trimethyl(2,4-pentanedionate) platinum complex, trimethyl(3,5-heptanedionate) platinum complex, trimethyl(methylacetoacetate) platinum complex, bis(2,4-pentanedionato) platinum complex, bis(2,4-hexanedionato) platinum complex, bis(2,4-heptanedionato) platinum complex, bis(3,5-heptanedionato) platinum complex, bis(1-phenyl-1,3-butanedionato) platinum complex, and bis(1,3-diphenyl-1,3-propanedionato) platinum complex. Furthermore, platinum complexes having cyclic diene compounds as ligands include, for example, (1,5-cyclooctadienyl)dimethylplatinum complex, (1,5-cyclooctadienyl)diphenylplatinum complex, (1,5-cyclooctadienyl)dipropylplatinum complex, (2,5-norboradienene)dimethylplatinum complex, (2,5-norboradienene)diphenylplatinum complex, (cyclopentadienyl)dimethylplatinum complex, (methylcyclopentadienyl)diethylplatinum complex, (trimethylsilylcyclopentadienyl)diphenylplatinum complex, (methylcycloocta-1, Examples include 5-dienyl)diethylplatinum complex, (cyclopentadienyl)trimethylplatinum complex, (cyclopentadienyl)ethyldimethylplatinum complex, (cyclopentadienyl)acetyldimethylplatinum complex, (methylcyclopentadienyl)trimethylplatinum complex, (methylcyclopentadienyl)trihexylplatinum complex, (trimethylsilylcyclopentadienyl)trimethylplatinum complex, (dimethylphenylsilylcyclopentadienyl)triphenylplatinum complex, and (cyclopentadienyl)dimethyltrimethylsilylmethylplatinum complex. These may be used individually or in combination of two or more.

[0078] The amount of photoactive catalyst used can be set to a blending ratio sufficient to promote the crosslinking reaction of the curable composition. For example, when the photoactive catalyst is a platinum complex, the amount of platinum metal is preferably in the range of 1 to 5,000 ppm by mass, and more preferably 10 to 500 ppm, relative to the total blending mass of polyrotaxane (R) and organopolysiloxane having a crosslinking group.

[0079] Polymerization initiators may be used as components that promote the crosslinking reaction by the enthiol reaction. The polymerization initiator is a compound that promotes the crosslinking reaction under active energy ray irradiation, and known ones can be used. Specific examples include 1-hydroxycyclohexylphenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1-(4-isopropyl ether) Examples include phenyl)-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis-(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxy. Commercially available products include BASF products Omnirad 184, 369, 651, 500, 907, 1173, TPO H, etc. Acetophenone compounds are preferred from the viewpoint of promoting the crosslinking reaction. Polymerization initiators can be used individually or in combination of two or more. The amount of polymerization initiator used can be appropriately selected to be an amount effective for initiating the reaction by active energy ray irradiation. For example, 0.1 to 5 parts by mass is preferred per 100 parts by mass of the total of polyrotaxane (R) and organopolysiloxane having a crosslinking group.

[0080] <Functional Fillers> Functional fillers are inorganic or organic fillers that do not inhibit the curing properties of the curable composition. Depending on the function, known fillers such as thermal conductive fillers, conductive fillers, magnetic fillers, dielectric fillers, thixotropic fillers, and shock-absorbing fillers can be selected. These functional fillers have the function of imparting desired properties to the curable composition or its cured product. Functional fillers can be blended into the curable composition in a proportion corresponding to the degree of the function to be imparted, as long as the effects of the present invention are not impaired.

[0081] [Thixotropic Fillers] Thixotropic fillers are components that can impart thixotropic properties to a curable composition, that is, properties in which viscosity is high in the low shear rate region and decreases in the high shear rate region. One or more known thixotropic fillers can be used. Suitable thixotropic fillers include, for example, inorganic fine particles such as fine silica, calcium carbonate, heavy calcium carbonate, bentonite, and sepiolite; resin fine particles such as Teflon® and silicone; long-chain fatty acid ester polymers; amide waxes; oxidized polyethylene waxes; sulfate ester-based anionic surfactants; polycarboxylic acids; polycarboxylic acid amine salts; polyethers; and other organic compounds. The shape of the fine particles can be spherical, rod-shaped, flaky, or as appropriate.

[0082] [Thermal Conductivity Fillers] Thermal conductivity fillers are components that impart thermal conductivity to a curable composition or its cured product, and one or more known types can be used in combination. Examples of thermal conductivity fillers include silica (quartz), aluminum oxide (alumina), aluminum hydroxide, magnesia, zinc oxide, boron nitride, aluminum nitride, silicon nitride, mica, ferrite, graphite, carbon nanotubes, carbon microcoils, etc.

[0083] [Conductive Filler] A conductive filler is a component that imparts electrical conductivity to a curable composition or its cured product, and one or more known types can be used in combination. Examples of conductive fillers include metals, graphite, carbon nanotubes, carbon microcoils, carbon-based materials such as fullerenes, and metal oxides such as zinc oxide.

[0084] [Magnetic Filler] A magnetic filler is a component that imparts magnetism to a curable composition or its cured product, and one or more known magnetic fillers can be used in combination. Examples of magnetic fillers include iron powder, Fe alloys such as Fe-Si alloy powder, Fe-Ni alloy powder, Fe-Co alloy powder, Fe-Cr alloy powder, and Fe-Cr-Si alloy powder, spinel-type ferrites such as Mg-Zn ferrite, Mn-Zn ferrite, Mn-Mg ferrite, Cu-Zn ferrite, Mg-Mn-Sr ferrite, and Ni-Zn ferrite, and hexagonal ferrites such as Ba-Zn ferrite, Ba-Mg ferrite, Ba-Ni ferrite, Ba-Co ferrite, and Ba-Ni-Co ferrite.

[0085] [Dielectric Fillers] Dielectric fillers are components that impart dielectric properties to a curable composition or its cured product, and one or more known types can be used in combination. Examples of dielectric fillers include high-dielectric ceramic powders such as barium titanate, lead zirconate titanate (PZT), lanthanum-doped lead zirconate titanate (PLZT), strontium titanate, lead titanate, bismuth titanate, and bismuth barium titanate, as well as organic compounds having a thiocarbonyl group, such as thiourea derivatives, thioamide derivatives, thioketone derivatives, and dithiocarbamate ester derivatives.

[0086] [Impact-absorbing filler] The impact-absorbing filler is a component that imparts impact-absorbing properties to the cured product of the curable composition, and one or more known types can be used in combination. As the impact-absorbing filler, a micro hollow body having a synthetic resin outer shell is preferred. The micro hollow body has a synthetic resin, for example, a thermoplastic resin as its shell, and examples of such resins include polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyacrylic acid ester, polyacrylonitrile, polybutadiene, or copolymer resins thereof. In particular, from the viewpoint of impact absorption, vinylidene chloride resin, copolymer of vinylidene chloride and acrylonitrile, copolymer of acrylonitrile and methacrylonitrile, terpolymer of vinylidene chloride, acrylonitrile and divinylbenzene, copolymer resin mainly composed of styrene and acrylic, etc., and copolymer resin of vinylidene chloride and acrylonitrile is more preferred.

[0087] The micro-hollow bodies may be, for example, micro-hollow particles that have a thermoplastic resin shell and contain air or other gases inside, and may already be in a foamed state or have been expanded by heat. In particular, the type that has already completed expansion is preferred because it is less susceptible to deterioration of physical properties due to thermal expansion, and the expanded type has excellent buffering properties. For example, a type that expands with heat may expand at 80 to 150°C, with a diameter of four times or more and a volume of approximately 50 to 100 times or more. The average particle diameter is preferably 1 to 250 μm, more preferably 30 to 150 μm, and the density (true density) is 20 to 50 kg / m³. ３ This is preferable. Furthermore, low molecular weight compounds other than air, such as low boiling point hydrocarbons, or foaming agents may be present inside the shell walls of the minute hollow bodies.

[0088] As a specific example of a synthetic resin-based micro hollow sphere, there is "Expancel® 551DE" manufactured by Nippon Philite Co., Ltd., which is a micro hollow body made of a copolymer of vinylidene chloride and acrylonitrile, for example, "Expancel® 551DE40d42" (average particle size of 30-50 (40) μm, density of 42 kg / m³). ３) and Nippon Philite's "Expancell (registered trademark) 092DE120d30" (average particle size 100-140 (120) μm, density 30 kg / m³) ３ Examples include "Matsumoto Microspheres (registered trademark)" manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd. Additionally, "SARAN MICROSPHERES," provided by DOW CHEMICAL, can be used as a polyvinylidene chloride-based resin balloon.

[0089] Furthermore, balloons coated with inorganic powders such as calcium carbonate, talc, and titanium dioxide can also be used, such as the "Matsumoto Microsphere (registered trademark) MFL series" provided by Matsumoto Oil & Fat Pharmaceutical Co., Ltd., or "EMC" manufactured by Nippon Philite Co., Ltd.

[0090] <Other Optional Components> Other optional components include heat resistance modifiers, flame retardant modifiers, pigments, dyes, tackiness / adhesion modifiers, polymerization inhibitors, etc., as well as additives to improve weather resistance, such as antioxidants, UV absorbers, and light stabilizers. Known components can be used for these.

[0091] <Method for Producing Curable Compositions> Curable compositions are obtained by mixing polyrotaxane(R), organopolysiloxane having crosslinkable groups, and components as needed. The mixing method is not particularly limited, and as an example, a rotary / revolving mixer, a single-screw extruder, a twin-screw extruder, a kneader, a Banbury mixer, or a roll mill can be used. The order of mixing is not particularly limited. If the curable composition contains two or more organopolysiloxanes that can crosslink with each other, an organopolysiloxane having the same crosslinkable groups as the polyrotaxane(R) may be mixed with the polyrotaxane(R) beforehand, or the polyrotaxane(R) and an organopolysiloxane having crosslinkable groups that react with the polyrotaxane(R) may be mixed to partially initiate the crosslinking reaction beforehand, and then an organopolysiloxane having the same crosslinkable groups as the polyrotaxane(R) may be added to further initiate the crosslinking reaction.

[0092] ≪Cured product of curable composition≫ The cured product of this embodiment is obtained by the curing of the curable composition of the above embodiment through a crosslinking reaction. The preferred type of crosslinking reaction is crosslinking by heating and / or crosslinking by irradiation with active energy rays.

[0093] <Crosslinking Method by Heating> The cured product of this embodiment can be cured at room temperature, but when heating is used to improve curing efficiency, it is generally preferable to cure it at a heating temperature of 60 to 200°C. The curing time varies depending on the curing temperature and molding method, but is usually about 1 minute to 24 hours. Alternatively, primary curing may be performed at 60 to less than 100°C, followed by secondary curing at 100°C or higher.

[0094] <Crosslinking Method by Irradiation with Active Energy Rays> Active energy rays refer to infrared rays, visible light, ultraviolet rays, X-rays, electron beams, alpha rays, beta rays, or gamma rays, with ultraviolet rays being particularly preferred. In this specification, ultraviolet rays include near ultraviolet rays (wavelength 200-380 nm), far ultraviolet rays (wavelength 10-200 nm), and extreme ultraviolet rays (wavelength 1-10 nm). These active energy rays can be used individually or two or more simultaneously. The sources of these active energy rays are not particularly limited, but as sources of ultraviolet rays, for example, known generating means such as low-pressure mercury lamps, high-pressure mercury lamps, excimer ultraviolet (excimer UV) lamps, halide lamps, LED lights, or lasers can be used. Furthermore, examples of infrared radiation sources include lamps, resistance heating plates, or lasers; examples of visible light radiation sources include direct sunlight, lamps, fluorescent lamps, LED lights, or lasers; and examples of electron beam radiation sources include devices that utilize thermionic electrons generated from commercially available tungsten filaments, cold cathode devices that generate electrons by passing high-voltage pulses through a metal, and secondary electron devices that utilize secondary electrons generated by collisions between ionized gaseous molecules and metal electrodes. In addition, examples of alpha, beta, and gamma ray radiation sources include fissile materials such as Co60; and for gamma rays, vacuum tubes that collide accelerated electrons with the anode can be used. These active energy rays may be irradiated individually or in pairs or more simultaneously.

[0095] <Physical Properties of the Cured Product> The cured product of this embodiment is a gel-like or rubber-like cured product (silicone rubber or silicone gel). In particular, because it contains polyrotaxane(R) which readily becomes compatible with silicone materials and crosslinks with silicone materials, the cured product has excellent elongation and high deformation followability. For example, in a curable composition that does not contain functional fillers, a tensile elongation (elongation at break Eb) of 200% or more (in accordance with JIS K6251:2071) can be achieved. A tensile elongation (elongation at break Eb) of 1000% or more is more preferable, and a tensile elongation of 1500% or more is particularly preferable. When the cured product of this embodiment is used as a damping material, from the viewpoint of achieving high damping performance, the complex modulus of elasticity is preferably 1000 to 150000 (in accordance with JIS K7244-10), more preferably 1500 to 100000, and particularly preferably 2000 to 70000.

[0096] <Applications of the Cured Product> The cured product of this embodiment has excellent elongation and high deformation-following properties, and can therefore be used as a damping material, potting material, heat dissipation material, sealing material, coating material, vibration isolation material, vibration damping material, and optical adhesive (OCR, OCA). Furthermore, since the complex modulus of elasticity of the cured product according to this embodiment can be designed within a desired range, vibration absorption can be improved by designing it to exhibit high damping properties, and because it also has excellent elongation, it also has excellent vibration durability. Therefore, this cured product is suitably used as a damping member that supports and absorbs vibrations of precision parts such as camera modules. In addition, because the cured product according to this embodiment has excellent elongation, even when a heat dissipation sheet is formed by blending a high proportion of thermal conductive filler into the curable composition, its elongation is maintained, making it difficult to break. Therefore, it is suitably used as a durable heat dissipation sheet that dissipates heat generated from semiconductor etching equipment and the like while absorbing vibrations.

[0097] <Mechanism of Action> The polyrotaxane of this embodiment exhibits excellent compatibility with silicone compounds such as organopolysiloxanes. This is because the polysiloxane chain in group X is thought to contribute to improved compatibility with silicone compounds. Furthermore, by incorporating the polyrotaxane of this embodiment into a curable composition containing an organopolysiloxane having crosslinkable groups, the elongation of the cured product is improved. This is because the crosslinkable groups contained in the polyrotaxane undergo a crosslinking reaction with the crosslinkable groups of the organopolysiloxane, incorporating the polyrotaxane structure into the cured product.

[0098] In particular, when the cyclic molecule is a molecule having hydroxyl groups, such as cyclodextrin, the number of hydroxyl groups in the cyclic molecule can be reduced by introducing group X (and further groups Y and / or Z) by substituting the hydrogen atoms of the hydroxyl groups of the cyclic molecule, thereby increasing the hydrophobicity of the polyrotaxane. Furthermore, if hydrophobic groups are used as groups Y and Z, the hydrophobicity of the polyrotaxane can be further increased. By increasing the hydrophobicity of the polyrotaxane, the compatibility with silicone compounds can be further improved.

[0099] The present invention will be described in more detail below using examples, but the present invention is not limited to these examples.

[0100] <Measurement Method and Evaluation Method> [Method for Measuring Inclusion Rate] Dissolve polyrotaxane in DMSO-d6 and measure using an NMR measuring device. １¹H-NMR spectra were obtained, and the inclusion ratio was calculated using the integral values ​​derived from cyclodextrin with chemical shift values ​​of 4-6 ppm and the integral values ​​derived from cyclodextrin and polyethylene glycol with chemical shift values ​​of 3-4 ppm. [Method for measuring the average molecular weight of polyrotaxane] Using the NMR measurement results of polyrotaxane, the average number of ethylene oxide units X and the average number of α-cyclodextrin units Y in the polyethylene glycol structural molecule were determined, assuming that the number of terminal sealing group units in the polyrotaxane is 2. From the obtained average numbers X and Y, the number of terminal sealing group units (2), the theoretical molecular weight Ma of the ethylene oxide unit, the theoretical molecular weight Mb of α-cyclodextrin including the side chain, and the theoretical molecular weight Mc of the terminal sealing group unit, the average molecular weight of polyrotaxane was calculated using the following formula: Average molecular weight of polyrotaxane = X × Ma + Y × Mb + 2 × Mc

[0101] [Method for evaluating compatibility] The compatibility between polyrotaxane and organopolysiloxane was evaluated by visually inspecting the curable composition containing polyrotaxane in its uncured state. The evaluation criteria were that the absence of an insoluble separation phase was considered a pass, and the presence of an insoluble separation phase was considered a fail.

[0102] [Tensile Test: Measurement Method for Tensile Elongation (Elongation at Break Eb)] The cured material of the curable composition was formed into a 0.2 mm thick sheet and punched into a No. 6 dumbbell to be used as a measurement sample. The obtained measurement sample was measured using a tensile testing machine (Shimadzu Corporation product name "AG-Xplus") in accordance with JIS K6251:2017, under conditions of a tensile speed of 500 mm / min and at 23°C, to determine the tensile elongation (Elongation at Break Eb, in %). A larger value of tensile elongation Eb indicates better elongation.

[0103] <Synthesis Example 1: Synthesis of Polyrotaxane (R1)> [Steps 1, 2] Compound A was synthesized by the following method, which is the same as the method for synthesizing blocked polyrotaxane described in Example 1 of International Publication No. 2001 / 083566. However, in this example, the number-average molecular weight of the starting material polyethylene glycol was set to 35,000, (2-hydroxypropyl)-α-cyclodextrin was used instead of α-cyclodextrin, and the inclusion rate of compound A was set to 2%. That is, compound A was synthesized by the following procedure. [Step 1] 4 g of polyethylene glycol (number-average molecular weight 35,000) and 20 ml of dried methylene chloride were placed in a 100 ml Erlenmeyer flask and the polyethylene glycol was dissolved. The resulting solution was placed under an argon atmosphere and 0.8 g of 1,1-carbonyldiimidazole was added. The mixture was then stirred and reacted under an argon atmosphere at room temperature (20°C) for 6 hours. The resulting reaction product was poured into 300 ml of diethyl ether that had been stirred at high speed. After standing for 10 minutes, the liquid containing the precipitate was centrifuged at 10,000 rpm for 5 minutes. The precipitate was removed and vacuum-dried at 40°C for 3 hours to obtain 3.74 g of product. The obtained product was dissolved in 20 ml of methylene chloride. The resulting solution was added dropwise to 10 ml of ethylenediamine over 3 hours, and stirred for 40 minutes after addition. The resulting reaction mixture was subjected to a rotary evaporator to remove methylene chloride, then dissolved in 50 ml of water, placed in a dialysis tube (molecular weight cutoff 8,000), and dialyzed in water for 3 days. The obtained dialysate was dried in a rotary evaporator, and the resulting dry product was dissolved in 20 ml of methylene chloride and reprecipitation with 180 ml of diethyl ether. The liquid containing the precipitate was centrifuged at 100,000 rpm for 5 minutes and vacuum-dried at 40°C for 2 hours to obtain 2.83 g of a product (abbreviated as DAT-PEG) in which amino groups were introduced at both ends of polyethylene glycol. Next, 3.6 g of (2-hydroxypropyl)-α-cyclodextrin (abbreviated as CD) and 0.9 g of the DAT-PEG (molecular weight approximately 35,000) obtained above were each dissolved in 15 ml of water at 80°C. The two were then mixed and refrigerated at 5°C for 6 hours to form a pseudo-polyrotaxane structure. Subsequently, the mixture was vacuum-dried at 40°C for 12 hours.[Step 2] Next, the intermediate having a pseudopolyrotaxane structure obtained above was placed in a 100 ml Erlenmeyer flask. Separately, a mixed solution was prepared by mixing 10 ml of N,N-dimethylformamide and 2.4 ml of 2,4-dinitrofluorobenzene. This mixed solution was added dropwise to the Erlenmeyer flask and reacted at room temperature under argon sealing. After 5 hours, 40 ml of dimethyl sulfoxide was added to the mixture in the Erlenmeyer flask to make a clear solution. This clear solution was added dropwise to 750 ml of water that had been vigorously stirred to obtain a pale yellow precipitate. This precipitate was dissolved again in 50 ml of dimethyl sulfoxide, and this solution was added dropwise to 700 ml of 0.1% sodium chloride aqueous solution that had been vigorously stirred to allow for further precipitation. The obtained precipitate was washed with water and methanol. During washing, after washing with each solution, centrifugation at 10,000 rpm for 1 minute was performed three times for each solution. The obtained substance was vacuum dried at 50°C for 12 hours to obtain 3.03 g of compound A. The resulting compound A has a cyclic molecule (2-hydroxypropyl-α-cyclodextrin) having a hydroxyl group, a linear molecule (polyethylene glycol), and chelating groups (monovalent groups obtained by removing a fluorine atom from 2,4-dinitrofluorobenzene) located at both ends of the linear molecule, and the cyclic molecule encloses the linear molecule that penetrates through its opening.

[0104] [Step 3] Under a nitrogen atmosphere, 500 mg (11 μmol) of compound A obtained in Step 2 was added to 7 mL of anhydrous N-methylpyrrolidone and heated to 50°C until dissolved. 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene (0.3 mL, 2.1 mmol) was added as a catalyst and the mixture was stirred for 5 minutes. Then, a monomer solution of 3.6 g, 16.4 mmol of hexamethylcyclotrisiloxane dissolved in 10 mL of THF was added in portions and reacted for 8 hours. After that, the mixture was cooled in an ice bath to obtain a solution of compound B. [Step 4] Pyridine (2 mL, 25 mmol) was added to the solution of compound B as a reaction byproduct trapping agent, and chlorodimethylvinylsilane (2.5 mL, 18 mmol) was added as compound C. The mixture was stirred at 7°C for 1 hour, and then stirred at room temperature for another 1 hour to synthesize the target polyrotaxane. The solvent was then removed by vacuum distillation, 30 mL of water was added, the precipitated material was collected, 30 mL of methanol was added for decantation, and the precipitate was purified by column chromatography. The yield was 31%. See below. １ ¹H-NMR analysis confirmed that the obtained polyrotaxane contained a polydimethylsiloxy group with a vinyl group at its terminus as group X, and a dimethylvinylsilyl group as group Y. The average number of silicon atoms in group X per cyclic molecule was approximately 670. １ H-NMR (CDCl ３ ): 0–0.1 (m, 17,000H), 3.62 (s, 3,200H), 5.60–6.20 (m, 414H) The average molecular weight of the obtained polyrotaxane (R1) was 265,000, and the sum of the number of groups X and Y per polyrotaxane molecule was 138. The inclusion rate of the polyrotaxane was 2.5%.

[0105] <Synthesis Example 2: Synthesis of Polyrotaxane (R2)> [Steps 1-3] A solution of compound B was obtained in the same manner as in steps 1-3 of Synthesis Example 1. [Step 4] Pyridine (2 mL, 25 mmol) was added to the solution of compound B as a reaction by-product trapping agent, and chlorodimethylsilane (2.0 mL, 18 mmol) was added as compound C. The mixture was stirred at 7°C for 1 hour, and then stirred at room temperature for 1 hour to synthesize the target polyrotaxane. The solvent and other substances were then removed by vacuum distillation, 30 mL of water was added, the precipitated product was collected, 30 mL of methanol was added for decantation, and the product was purified by column chromatography. The yield was 31%. See below. １ ¹H-NMR analysis confirmed that the obtained polyrotaxane contained a polydimethylsiloxy group with a hydrosilyl group at its terminus as group X, and a dimethylsilyl group as group Y. The average number of silicon atoms in group X per cyclic molecule was approximately 670. １ H-NMR (CDCl ３ ): 0–0.1 (m, 17,000H), 3.62 (s, 3,200H), (m, 414H), 4.70–4.77 (m, 138H) The average molecular weight of the obtained polyrotaxane (R2) was 261,000, and the sum of the number of groups X and Y per polyrotaxane molecule was 138. The inclusion rate of the polyrotaxane was 2.5%.

[0106] <Raw Materials> In the following example, (S1-1), (S1-2), (S2-1), and (S2-2) were used as organopolysiloxanes having crosslinkable groups. [S1: First organopolysiloxane] (S1-1) Vinyl-modified polydimethyldiphenyl silicone at both ends, product name "PDV-0331", manufactured by Gelest, molecular weight 27,000, viscosity 1,000 mm ２ / s, average number of functional groups per molecule: 2. (S1-2) Hydrogen-modified polydimethyl silicone at both ends, product name "DMS-H21", manufactured by Gelest, molecular weight 4,500, viscosity 100 mmHg ２ / s, average number of functional groups per molecule: 2. [S2: Second organopolysiloxane] (S2-1) Side-chain hydrogen-modified polydimethyl silicone, product name "HMS-082", manufactured by Gelest, molecular weight 6,000, viscosity 130 mm ２ / s, average number of functional groups per molecule: 6.57. (S2-2) Side-chain vinyl-modified polydimethyl silicone, product name "RH-Vi315", manufactured by Construe Chemical, molecular weight 35,000, viscosity 1,500 mmHg ２ / s, average number of functional groups per molecule: 4.67.

[0107] <Example 1> (Preparation of curable composition) 0.50 g of polyrotaxane (R1) obtained in Synthesis Example 1, 9.13 g of vinyl-modified polydimethyldiphenylsiloxane (S1-1), 0.87 g of side-chain hydrogen polydimethylsiloxane (S2-1), and 150 μL of platinum complex catalyst (product name "Catalist EP", manufactured by Asahi Kasei Wacker Co., Ltd.) were mixed. This mixture was kneaded at 2000 rpm for 3 minutes using a rotation-revolution mixer (product name "Awatori Rentaro (registered trademark) ARE-350", manufactured by Thinky Co., Ltd.), and then centrifuged and degassed at 2200 rpm for 1 minute to obtain a curable composition. In this example, the ratio of the total number of moles of hydrosilyl groups to the total number of moles of vinyl groups (molar ratio of crosslinkable groups, hereinafter referred to as "hydrosilyl group / vinyl group") is 1.0. In other words, the ratio of the number of moles of the hydrosilyl group in (S2) to the total number of moles of the vinyl group in (R) and the vinyl group in (S1) is 1.0. Also, the content of (R) relative to the total mass of (R), (S1), and (S2) (hereinafter referred to as "R / (R+S1+S2)") is 4.8% by mass. The compatibility of the uncured curable composition obtained in this example was evaluated using the method described above. The formulation of the main raw materials and the evaluation results are shown in Table 1 (the same applies hereinafter).

[0108] (Manufacturing of Cured Product) Next, the uncured cured composition obtained above was calendered to form a 0.2 mm thick sheet, preheated at 70°C for 1 hour in a hot air oven (product name "WFO-520W", manufactured by Tokyo Rikakikai Co., Ltd.), and then heated at 100°C for 3 hours to obtain a 0.2 mm thick sheet-like cured product. The tensile elongation (Eb) of the obtained cured product was measured using the method described above to evaluate its elongation. The results are shown in Table 1 (the same applies below).

[0109] <Example 2> In Example 1, the amount of compounding was changed so that the molar ratio of hydrosilyl group to vinyl group was 6.0. That is, (R1) was changed to 0.50 g, (S1-1) to 6.11 g, and (S2-1) to 3.89 g, but otherwise the procedure was the same as in Example 1. A curable composition and a cured product were prepared in the same manner as in Example 1, and the compatibility and elongation of the cured product were evaluated (the same applies hereafter).

[0110] <Example 3> In Example 1, the blending amounts were changed so that R / (R+S1+S2) was 1.0% by mass. That is, (R1) was changed to 0.10 g, (S1-1) to 9.31 g, and (S2-1) to 0.69 g, but otherwise the same as in Example 1 was used.

[0111] <Example 4> In Example 1, polyrotaxane (R1) was changed to polyrotaxane (R2) obtained in Synthesis Example 2, (S1-1) was changed to (S1-2), and (S2-1) was changed to (S2-2). The blending amounts were changed so that R / (R+S1+S2) was the same as in Example 1, 4.8% by mass. That is, (R2) was changed to 0.50 g, (S1-2) to 1.90 g, and (S2-2) to 8.10 g, but otherwise it was the same as in Example 1.

[0112] <Example 5> In Example 4, the blending amounts were changed so that R / (R+S1+S2) was 1.0% by mass. That is, (R2) was changed to 0.10 g, (S1-2) to 2.30 g, and (S2-2) to 7.70 g, but otherwise the same as in Example 4 was used.

[0113] <Example 6> In Example 4, the blending amounts were changed so that R / (R+S1+S2) was 9.1% by mass. That is, (R2) was changed to 1.00 g, (S1-2) to 1.50 g, and (S2-2) to 8.50 g, but otherwise the same as in Example 4 was used.

[0114] <Comparative Example 1> In this example, a curable composition was prepared without using polyrotaxane. The same end-vinyl modified polydimethyldiphenylsiloxane (S1-1), side-chain hydrogen-modified polydimethylsiloxane (S2-1), and platinum complex catalyst as in Example 1 were used. The formulation was modified so that the ratio of moles of hydrosilyl groups in (S2-1) to moles of vinyl groups in (S1-1) (hydrosilyl groups / vinyl groups) was 1.0. That is, the formulation consisted of 9.41 g of (S1-1), 0.65 g of (S2-1), and 150 μL of platinum complex catalyst mixed together. A curable composition was prepared in the same manner as in Example 1, and its compatibility and the elongation of the cured product were evaluated.

[0115] <Comparative Example 2> In Comparative Example 1, the amount of each compound was changed so that the molar ratio of hydrosilyl group to vinyl group was 6.0. Specifically, (S1-1) was changed to 7.11 g and (S2-1) to 2.89 g. Otherwise, the curable composition was prepared in the same manner as in Example 1, and the compatibility and elongation of the cured product were evaluated.

[0116] <Comparative Example 3> In Comparative Example 1, (S1-1) was changed to (S1-2) and (S2-1) was changed to (S2-2). The amount of each compound was changed so that the molar ratio of hydrosilyl group to vinyl group was 1.0, the same as in Comparative Example 1. That is, (S1-2) was 2.29 g and (S2-2) was 7.71 g. Otherwise, the curable composition and cured product were produced in the same manner as in Comparative Example 1, and the compatibility and elongation of the cured product were evaluated.

[0117]

[0118]

[0119] As shown in Tables 1 and 2, the curable compositions of Examples 1 to 6 exhibited good compatibility, and the elongation of the cured products was improved compared to Comparative Examples 1 to 3, which did not contain polyrotaxane. Specifically, comparing the tensile elongation (Eb) values, Example 1 was 165% of Comparative Example 1, Example 2 was 201% of Comparative Example 2, Example 3 was 189% of Comparative Example 1, Example 4 was 254% of Comparative Example 3, Example 5 was 164% of Comparative Example 3, and Example 6 was 285% of Comparative Example 3.

[0120] The polyrotaxane of the present invention exhibits excellent compatibility when blended into a curable composition containing a silicone resin, and also has reactivity with curable silicone components. Therefore, it is useful as a component that can add polyrotaxane-derived effects to the cured product of the curable composition, and in particular improves the elongation of the cured product. As a result, it can be used as a damping material, potting material, heat dissipation material, sealing material, coating material, vibration isolation material, vibration damping material, and optical adhesive (OCR, OCA).

Claims

1. A polyrotaxane comprising one or more cyclic molecules, a linear molecule, and choke groups located at both ends of the linear molecule, wherein the cyclic molecule encloses the linear molecule penetrating its opening, and part or all of the cyclic molecule has a polysiloxane chain and a crosslinkable group X.

2. The polyrotaxane according to claim 1, wherein the cyclic molecule has a hydroxyl group, and at least a portion of the hydrogen atoms of the hydroxyl group are substituted with the group X.

3. The polyrotaxane according to claim 1, wherein the cyclic molecule further has a group Y, and the group Y does not contain a polysiloxane chain and has a crosslinking group.

4. The polyrotaxane according to claim 3, wherein the cyclic molecule has a hydroxyl group, and at least a portion of the hydrogen atoms of the hydroxyl group are substituted with group X or group Y.

5. The polyrotaxane according to claim 1, wherein the cyclic molecule further has a group Z, and the group Z does not contain a polysiloxane chain or a crosslinking group but has a non-crosslinking group.

6. The polyrotaxane according to claim 5, wherein the cyclic molecule has a hydroxyl group, and at least a portion of the hydrogen atoms of the hydroxyl group are substituted with group X or group Z.

7. A method for producing a polyrotaxane, comprising: dissolving compound A, which has one or more cyclic molecules, linear molecules, and chelating groups located at both ends of the linear molecules, wherein the cyclic molecules enclose the linear molecules penetrating through their openings, and the cyclic molecules have hydroxyl groups, in an organic solvent; ring-opening addition of a cyclic siloxane to at least a portion of the hydroxyl groups of the cyclic molecules to form a polysiloxane chain having hydroxyl groups at its termini to obtain compound B; and reacting compound C, which has a crosslinking group and reacts with a hydroxyl group, with compound B to introduce the crosslinking group to at least a portion of the termini of the polysiloxane chain.

8. A method for producing a polyrotaxane, comprising: dissolving compound A, which has one or more cyclic molecules, linear molecules, and chelating groups located at both ends of the linear molecules, wherein the cyclic molecules enclose the linear molecules penetrating through their openings, and the cyclic molecules have hydroxyl groups, in an organic solvent; ring-opening addition of a cyclic siloxane to at least a portion of the hydroxyl groups of the cyclic molecules to form a polysiloxane chain having hydroxyl groups at its termini to obtain compound B; reacting compound D, which has halogen groups and reacts with hydroxyl groups, with compound B to introduce the halogen groups to at least a portion of the termini of the polysiloxane chain, and then substituting the halogen groups with mercapto groups.

9. A curable composition containing a polyrotaxane according to any one of claims 1 to 6 and an organopolysiloxane having a crosslinking group.

10. A cured product formed from the curable composition described in claim 9.

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