JP2022182934A - Polyrotaxane - Google Patents

Abstract

To provide a polyrotaxane capable of improving mechanical properties of a resin such as a curable resin.SOLUTION: Polyrotaxane has a straight chain molecule, a cyclic molecule and a sealing group. The cyclic molecule includes the straight chain molecule in a skewered state. The sealing group is arranged at both terminals of the straight chain molecule. The cyclic molecule has an external stimulation reaction type ring-opening functional group composed of cyclic aliphatic ether and/or cyclic aliphatic thioether.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polyrotaxane, a curable resin composition containing the polyrotaxane, and a cured product thereof.

In recent years, in the field of structural materials using polymers, developments have been made to improve mechanical properties (that is, mechanical properties). As such a polymer, a polyrotaxane is known which consists of a cyclic molecule, a linear molecule penetrating the cyclic molecule in a skewed manner, and blocking groups arranged at both ends of the linear molecule. . A blocking group is positioned such that the cyclic molecule does not detach, and is also called a blocking group.
Polyrotaxane has a structure in which cyclic molecules can move along linear molecules, so it is expected to be applied to resins with excellent mechanical properties.

For example, in Patent Document 1, a material is developed in which a polyrotaxane or a crosslinked product thereof is bonded to a polymer (that is, a resin) via a cyclic molecule of the polyrotaxane. According to Patent Document 1, it is possible to develop a material having both the properties of a crosslinked polymer and the properties of a crosslinked polyrotaxane.

WO2005/095493

Curable resins such as thermosetting resins and photocurable resins are cured by external stimuli such as heat and light, and do not require special equipment or methods for curing. Therefore, curable resins are used in a wide variety of applications. On the other hand, curable resins are also desired to further improve their physical properties. , improvement in mechanical properties is desired. However, even if a conventional polyrotaxane such as that described in Patent Document 1 is applied to a curable resin, it has been difficult to obtain an effect of improving mechanical properties. This is probably because the chemical interaction between the conventional polyrotaxane and the curable resin (more specifically, the polymer that constitutes the curable resin) is low.

An object of the present invention is to solve the above problems. That is, the present invention aims to provide a polyrotaxane capable of improving the mechanical properties of a resin such as a curable resin, a curable resin composition containing the polyrotaxane, and a cured product thereof.

As a result of intensive studies aimed at solving the above problems, the present inventors found that the mechanical properties of resins such as curable resins can be improved by introducing an external stimuli-reactive ring-opening functional group into polyrotaxanes. , led to the present invention. That is, the gist of the present invention resides in the following.

[1] a linear molecule;
a cyclic molecule that clathrates the linear molecule in a skewered manner;
and a blocking group arranged at both ends of the linear molecule,
The polyrotaxane, wherein the cyclic molecule has an external stimulus-reactive ring-opening functional group composed of a cyclic aliphatic ether and/or a cyclic aliphatic thioether.
[2] The cyclic molecule according to [1], wherein the cyclic molecule has a cyclic main chain, a side chain linked to the main chain, and the external stimulus-responsive ring-opening functional group linked to the side chain. Polyrotaxane.
[3] to [2], wherein the side chain of the cyclic molecule has an ether group, and the cyclic molecule has the external stimuli-responsive ring-opening functional group linked to the side chain via the ether group; The polyrotaxane described.
[4] The polyrotaxane according to [2] or [3], wherein the side chain of the cyclic molecule is composed of polyester.

[5] The polyrotaxane according to [2] or [3], wherein the side chain of the cyclic molecule is composed of polycaprolactone.
[6] The polyrotaxane according to any one of [1] to [5], wherein the external stimulus-reactive ring-opening functional group is an epoxy group and/or an oxetane group.
[7] The polyrotaxane according to [6], wherein the external stimulus-reactive ring-opening functional group is an epoxy group.

[8] The cyclic molecule has a cyclic main chain, a side chain linked to the main chain, and the external stimulus-responsive ring-opening functional group linked to the side chain, and the side chain has a molecular weight of The polyrotaxane according to [1], which is less than 500.
[9] the side chain of the cyclic molecule has an ether bond, a carbonate bond, or a carbamate bond, and the external stimuli-responsive ring-opening functional group linked to the side chain via the bond; The polyrotaxane according to [8].
[10] The polyrotaxane according to [8] or [9], wherein the cyclic molecule has the external stimulus-reactive ring-opening functional group directly linked to the main chain via a carbonate bond.

[11] The polyrotaxane according to any one of [8] to [10], wherein the number of external stimulation-reactive ring-opening functional groups per cyclic molecule is 0.1 to 9.
[12] The polyrotaxane according to any one of [8] to [11], wherein the external stimulus-reactive ring-opening functional group is an epoxy group and/or an oxetane group.
[13] The polyrotaxane according to [12], wherein the external stimulus-reactive ring-opening functional group is an epoxy group.

[14] The polyrotaxane (A) according to any one of [1] to [13];
a resin (B) capable of reacting with the external stimulus-reactive ring-opening functional group of the polyrotaxane;
A curable resin composition comprising a curing agent (C).

[15] The curable resin composition according to [14], containing 0.1 to 30% by mass of the polyrotaxane (A).
[16] The curable resin composition according to [14] or [15], wherein the external stimulus-reactive ring-opening functional group is an epoxy group, and the resin (B) is an epoxy resin.
[17] The curable resin composition according to [16], wherein the epoxy resin contains an epoxy resin having a linear aliphatic skeleton in the main chain constituting the epoxy resin.
[18] A cured product obtained by curing the curable resin composition according to any one of [15] to [17].

According to the polyrotaxane, it is possible to improve the mechanical properties of a resin such as a curable resin. Examples of mechanical properties include elasticity and toughness.
According to the curable resin composition, a cured product having excellent mechanical properties such as toughness can be obtained. For example, by curing the curable resin composition, a cured product having excellent mechanical properties such as toughness can be obtained.

Embodiments of the present invention will be described in detail below. is not limited to the contents of
In addition, when the expression "~" is used in this specification, it is used in the sense of including the numerical values or physical values described before and after it. Numerical values or physical values described as the upper limit and the lower limit are used in the sense of including those values.
Further, in this specification, toughness is evaluated, for example, by a tensile test, and an improvement in tensile elongation at break without a decrease in tensile modulus is an index of improvement in mechanical properties (more specifically, improvement in toughness). and

[Polyrotaxane]
A polyrotaxane has at least a linear molecule, a cyclic molecule, and a capping group. Linear and cyclic molecules are specifically macromolecules. The cyclic molecule clathrates the linear molecule in a skewered manner. The cyclic molecule has an external stimulus responsive ring-opening functional group, and the external stimulus responsive ring-opening functional group is composed of a cycloaliphatic ether and/or a cycloaliphatic thioether. The external stimulus-responsive ring-opening functional group means a functional group having a cyclic structure, the cyclic structure of which can be opened in response to an external stimulus such as heat or light.
The blocking groups are arranged at both ends of the linear molecule, and specifically are bonded to both ends of the linear molecule. The blocking group can prevent the cyclic molecule from detaching from the end of the linear molecule. The blocking group is large enough to prevent the cyclic molecule from detaching from the end of the linear molecule, and more specifically, has a maximum length greater than the diameter of the opening of the cyclic molecule. have. The linear molecules, cyclic molecules, and sealing groups that constitute the polyrotaxane are described in detail below.

Linear molecules include, for example, cellulose-based resins such as carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; polyvinyl alcohol, polyvinylpyrrolidone, poly(meth) ) acrylic acid, polyacrylamide, polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch, and copolymers of two or more of these examples.
Examples of linear molecules include polyolefin resins such as polyethylene and polypropylene; polystyrene resins such as polystyrene and acrylonitrile-styrene copolymers; polymethyl methacrylate, (meth)acrylic ester copolymers, acrylonitrile- acrylic resins such as methyl acrylate copolymers; polyester resins, polyvinyl chloride resins, polycarbonate resins, polyurethane resins, vinyl chloride-vinyl acetate copolymers, polyvinyl butyral resins, and derivatives or modified products thereof.
Furthermore, linear molecules include, for example, polysiloxanes such as polydimethylsiloxane; polydienes such as polyisoprene and polybutadiene; polyamides such as nylon; polyisobutylene, polyaniline, acrylonitrile-butadiene-styrene copolymer (that is , ABS resin), polyimides, polysulfones, polyimines, polyacetic anhydrides, polyureas, polysulfides, polyphosphazenes, polyketones, polyphenylenes, polyhaloolefins, and derivatives thereof.

As linear molecules, polyalkylene glycols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol; polyolefin resins such as polyethylene and polypropylene; and polysiloxanes such as polydimethylsiloxane are preferable, and polyethylene glycol is more preferable.

The molecular weight of the linear molecule is preferably 1,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more. Although the upper limit of the molecular weight of the linear molecule is not particularly limited, it is about 1,000,000 from the viewpoint of handleability. Molecular weight means number average molecular weight and is measured according to JIS K7252-1:2016, for example.

The cyclic molecule preferably has a cyclic main chain, a side chain linked to the main chain, and an external stimuli-responsive ring-opening functional group linked to the side chain. In this case, it is possible to improve the tensile elastic modulus while suppressing a decrease in the tensile elongation at break, or to improve the tensile elongation at break while suppressing a decrease in the tensile elastic modulus.

The backbone of the cyclic molecule includes, for example, a cyclodextrin molecule. Cyclodextrin molecules include, for example, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and derivatives thereof.

<First preferred form>
A first preferred form of polyrotaxane will be described. Incidentally, the first preferred form will be hereinafter referred to as the first form as appropriate.
In the polyrotaxane of the first form, the side chain of the cyclic molecule preferably has an ether group, and the side chain preferably has the above-described external stimulation-reactive ring-opening functional group via the ether group. In this case, the synthesis of the polyrotaxane is facilitated, and the stability of the bond between the external stimulation-reactive ring-opening functional group and the cyclic molecule is improved.

In the polyrotaxane, it is preferred that the linear molecule is polyethylene glycol and the cyclic molecule is α-cyclodextrin. In this case, the synthesis of the polyrotaxane is facilitated, and the effect of improving the mechanical properties of the polyrotaxane is likely to be obtained.

The side chains of the cyclic molecules are preferably made of polyester. In this case, an effect of improving compatibility with the matrix resin described later is obtained.

The side chain of the cyclic molecule is preferably composed of polycaprolactone. In this case, the compatibility with the epoxy resin is particularly improved.

From the viewpoint of facilitating movement of the cyclic molecule on the linear molecule, the inclusion amount of the cyclic molecule in the polyrotaxane is preferably 0.6 or less, more preferably 0.5 or less, and even more preferably 0.4 or less. On the other hand, the inclusion amount is preferably 0.001 or more, more preferably 0.01 or more, and even more preferably 0.05 or more, from the viewpoint of facilitating the manifestation of the effect of improving mechanical properties by the polyrotaxane.
The clathrate amount is the maximum amount of cyclic molecules clathrated on the linear molecule while a large number of cyclic molecules are clathrated one after another by the linear molecule (that is, the maximum clathrate amount). is expressed as a relative value when is set to 1.

The maximum inclusion amount of the cyclic molecule can be determined by the length of the linear molecule and the thickness of the cyclic molecule. For example, when the linear molecule is polyethylene glycol and the cyclic molecule is α-cyclodextrin, the maximum inclusion amount has been determined experimentally (see Macromolecules 1993, 26, p.5698-5703). thing.).

The blocking group is not particularly limited as long as it has the effect of preventing the cyclic molecule from leaving the linear molecule.
Examples of sealing groups include dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes, substituted benzenes, optionally substituted polycyclic aromatics, and steroids. mentioned.
Examples of substituents in substituted benzenes and optionally substituted polycyclic aromatics include alkyl groups, alkyloxy groups, hydroxy groups, halogen groups, cyano groups, sulfonyl groups, carboxy groups, amino groups, A phenyl group is mentioned. One or more substituents may be present.

As the sealing group, dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins and pyrenes are preferred, and adamantane groups and trityl groups are more preferred.

The external stimulus-responsive ring-opening functional group is not particularly limited as long as it is a functional group capable of ring-opening in response to some external stimulus. The external stimulus responsive ring-opening functional group is composed of a cycloaliphatic ether and/or a cycloaliphatic thioether.
Cycloaliphatic ethers include, for example, an epoxy group and an oxetane group.
Cycloaliphatic thioethers include, for example, an ethylene sulfide group.

The external stimuli-reactive ring-opening functional group is preferably an epoxy group and/or an oxetane group. In this case, the effect of easily controlling the reactivity with the matrix resin is obtained.

The external stimulation-reactive ring-opening functional group is preferably a functional group capable of efficiently reacting with the matrix resin, and the mutual reaction improves the mechanical properties of the resulting cured product.
For example, when an epoxy resin is used as the matrix resin, the external stimulation-reactive ring-opening functional group is preferably an epoxy group.

From the viewpoint that the crosslink density of the cured product does not increase and the effect of polyrotaxane to absorb stress is sufficiently exhibited, the number of external stimulus-reactive ring-opening functional groups per cyclic molecule is preferably 5 or less. , is more preferably 3 or less.
From the viewpoint that the stress-absorbing effect of the polyrotaxane is sufficiently expressed in the entire cured product, the number of external stimulus-reactive ring-opening functional groups per cyclic molecule is preferably 0.1 or more, and 1 or more. more preferred.

Preferably, the external stimuli-responsive ring-opening functional group is bonded to the cyclic molecule. In this case, the cyclic molecule has an external stimuli-responsive ring-opening functional group.
The compatibility in the curable resin composition and the compatibility as a cured product can be adjusted, the solubility in organic solvents is improved, and the reactivity with the resin (B) is improved. The stimuli-responsive ring-opening functional group is preferably bound to the cyclic molecule via a side chain.

The number of external stimulus-reactive ring-opening functional groups per side chain is preferably 0.01 to 3, depending on the degree of crosslink density required for the cured product.
The introduction position of the external stimulus-responsive ring-opening functional group in the side chain may be in the middle of the side chain or at the end.
As a method for introducing the external stimulus-reactive ring-opening functional group to the side chain, introduction via an ether group is preferred from the viewpoint of ease of synthesis and bond stability.

The side chain is preferably polyester, and more preferably aliphatic polyester when the resin (B) is an epoxy resin.
Aliphatic polyesters include, for example, polylactic acid, polyglycolic acid, poly-3-hydroxybutyrate, poly-4-hydroxybutyrate, poly(3-hydroxybutyrate/3-hydroxyvalerate), and polycaprolactone.
Among these, polycaprolactone is preferred from the viewpoint of compatibility with the epoxy resin, and specifically poly(ε-caprolactone) is more preferred.

The molecular weight of the side chain is preferably 500 to 100,000.

When the polyrotaxane has a configuration in which the cyclic molecule has an external stimulus-reactive ring-opening functional group and a side chain, the polyrotaxane reacts with the matrix resin while dispersing more uniformly in the matrix resin. A crosslinked structure can be formed. This further improves the mechanical properties of the matrix resin.

<Second preferred form>
Next, a second preferred form of polyrotaxane will be described. Incidentally, the second preferred form will be hereinafter referred to as the second form as appropriate.
In the polyrotaxane of the second form, it is preferable that the side chain of the cyclic molecule contains a linking group, and the cyclic molecule is linked to the external stimulus-responsive ring-opening functional group via the linking group. In this case, the effect of facilitating the synthesis of the polyrotaxane is obtained.
Linking groups include, for example, ether linkages, carbonate linkages, and carbamate linkages. From the viewpoint of improving the thermal stability of the bonding group (that is, the bonding site), the bonding group is preferably an ether bond and/or a carbonate bond, and from the viewpoint of compatibility with the epoxy resin, the bonding group is a carbonate. A bond is more preferred.

From the viewpoint of easily suppressing a decrease in elastic modulus, the molecular weight of the side chain excluding the binding group is preferably less than 500, more preferably 499 or less, even more preferably 400 or less, and 300 or less. 1 is particularly preferred and 0 is most preferred.
When the side chain has a molecular weight of 0, the external stimuli-responsive ring-opening functional group is directly linked to the main chain of the cyclic molecule via the linking group. Specifically, the cyclic molecule preferably has an external stimuli-responsive ring-opening functional group directly linked via a carbonate bond.
By reducing the molecular weight of the side chain that binds to the external stimulus-reactive ring-opening functional group, when external stress is applied to a cured product containing polyrotaxane, the stress propagates to the polyrotaxane portion of the cured product. easier to do. As a result, when stress is applied, the cyclic molecules move along the straight-chain molecules, facilitating relaxation of the stress, thereby facilitating improvement in mechanical properties (particularly toughness).

The average number of side chains having an external stimulus-responsive ring-opening functional group is preferably 0.1 to 9, more preferably 0.2 to 8, and 0.3 to 0.3 per main chain of the cyclic molecule. 7 is more preferred.
When the average number of side chains is within the above range, it is possible to improve the tensile elastic modulus while suppressing a decrease in tensile elongation at break, or to suppress a decrease in tensile elastic modulus and increase the tensile elongation at break. degree can be improved.

In a second embodiment, the main chain of the cyclic molecule may have side chains that do not have an external stimulus responsive ring-opening functional group. By having such a side chain, the intermolecular force of the polyrotaxane can be suppressed, and the compatibility with the epoxy resin and the curing agent can be enhanced.
The molecular weight of such side chains is less than 500, preferably 499 or less, more preferably 400 or less, and even more preferably 300 or less. Within this range, a decrease in elastic modulus can be suppressed.
The average number of side chains that do not have an external stimulus responsive ring-opening functional group is 0 to 15 per main chain of the cyclic molecule.

The average number of side chains that do not have an external stimulus-reactive ring-opening functional group and side chains that have an external stimuli-reactive ring-opening functional group is 4 or more per main chain of the cyclic molecule. is preferred. Within this range, the intermolecular force of the polyrotaxane can be suppressed, and the compatibility with the epoxy resin and the curing agent can be enhanced.

In the polyrotaxane, it is preferred that the linear molecule is polyethylene glycol and the cyclic molecule is α-cyclodextrin. In this case, the synthesis of the polyrotaxane is facilitated, and the effect of improving the mechanical properties of the polyrotaxane is likely to be obtained.

The inclusion amount of the cyclic molecule, the sealing group, and the external stimuli-reactive ring-opening functional group in the polyrotaxane are the same as in the first embodiment.

From the viewpoint that the cross-linking density of the cured product does not increase and the stress absorbing effect of the polyrotaxane is sufficiently expressed, the number of external stimulus-reactive ring-opening functional groups per cyclic molecule is 0.1 to 9. is.

[Method for producing polyrotaxane]
Polyrotaxane can be produced by the following steps (1) to (5). However, the method for producing polyrotaxane is not limited to this production method.
(1) a step of converting a terminal substituent of a linear molecule to prepare a linear molecule; Step (3) to block both ends of the linear molecule so that the cyclic molecule does not detach from the linear molecule to obtain a polyrotaxane having no blocking group (pseudopolyrotaxane). Step of obtaining (4) Step of modifying the side chain of the cyclic molecule of the polyrotaxane (5) Step of introducing an external stimuli-reactive ring-opening functional group to the cyclic molecule or the side chain of the cyclic molecule of the polyrotaxane

The step (1) is a step of converting a substituent of polyethylene glycol, which is a linear molecule, into another substituent. As a conversion method, a conversion method based on an induction method using ordinary organic synthesis can be used. In this case, multiple derivatization steps may be followed until a linking group is formed at the end of the polyethylene glycol moiety.
Also, depending on the terminal group of the starting linear molecule, the pseudo-polyrotaxane may be obtained by carrying out the step (2) without going through the step (1).

The step (2) is a step of including a cyclic molecule in a linear molecule. In this step, a pseudo-polyrotaxane can be obtained, and it is preferable to carry out the step while controlling the inclusion amount of the cyclic molecule in the linear molecule. In this case, it is possible to control the time, humidity, temperature, pressure and the molecular weight of the linear molecule used when mixing the cyclic molecule and the linear molecule.
More specifically, there is a method of dissolving excess linear molecules in a saturated solution of cyclic molecules.
When a cyclic molecule is included in a linear molecule, the linear molecule and the cyclic molecule dissolved in an organic solvent or a mixed solvent of an aqueous solution and an organic solvent are allowed to stand as they are, or ultrasonic waves are generated. It may be left for several hours to several tens of hours. Moreover, it is preferable to adjust the temperature conditions appropriately.

Next, after standing still or after ultrasonic treatment, the solvent is removed from the reaction liquid by centrifugation, freeze drying, hot air drying, vacuum distillation, vacuum drying, vacuum drying, or the like to obtain a pseudopolyrotaxane. Alternatively, the pseudo-polyrotaxane having a higher purity may be obtained by washing with a suitable solvent or the like.

The step (3) is a step of blocking both ends of the linear molecule with blocking groups so that the cyclic molecule does not detach from the linear molecule to obtain a polyrotaxane. The blocking group can be introduced by a method using ordinary organic synthesis reactions. Solvents used in the reaction may be appropriately selected, and examples thereof include dimethylformamide and acetonitrile.

The step (4) is a step of modifying the cyclic molecule of the polyrotaxane with a side chain. A side chain of a cyclic molecule can be introduced by a method utilizing a normal organic synthesis reaction. There may be no solvent in the reaction. When using a solvent, for example, dimethylformamide, dimethylsulfoxide, acetonitrile can be mentioned.

The step (5) is a step of introducing an external stimuli-reactive ring-opening functional group into the cyclic molecule or the cyclic molecule side chain of the polyrotaxane. This functional group can be introduced by a method utilizing a normal organic synthesis reaction. It is preferred to use a solvent in the reaction.
In this step, a ring-opening functional group having internal strain is modified, and it is necessary to control the reaction by temperature and catalyst, so it is preferable to adjust the reaction conditions appropriately. Moreover, by selecting a solvent that disperses the polyrotaxane uniformly, the reaction can be favorably performed.
When purifying, it is preferable to exclude factors that induce reaction of the ring-opening functional group, such as water and active oxygen.

[Curable resin composition]
The curable resin composition comprises a polyrotaxane (A), a resin (B) capable of reacting with its external stimulus-reactive ring-opening functional group, and a curing agent (C). Incidentally, in the curable resin composition, the resin (B) tends to be, for example, the component with the largest mass ratio. In this specification, the resin (B) is sometimes referred to as a matrix resin.

[Resin (B) capable of reacting with external stimulation-reactive ring-opening functional group]
The resin (B) is preferably a resin capable of reacting with the externally stimulus-reactive ring-opening functional group of the polyrotaxane (A). Specifically, the resin (B) is preferably a resin capable of reacting with a cycloaliphatic ether such as an epoxy group or an oxetane group and/or a cycloaliphatic thioether such as an ethylene sulfide group.
Examples of the resin (B) include epoxy resins and oxetane resins.
Further, the resin (B) may be a resin having an external stimuli-reactive ring-opening functional group such as an epoxy group, an oxetane group, or an ethylene sulfide group. Examples include resins, polycarbonate resins, polyethylene resins, polypropylene resins, polyvinyl chloride resins, polystyrene resins such as polystyrene and acrylonitrile-styrene copolymers, polyurethane resins, and silicone resins.
As the resin (B), an epoxy resin, which is particularly required to improve mechanical properties, is preferable.

[Epoxy resin]
Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, tetra Bromobisphenol A type epoxy resins, glycidyl ether type epoxy resins such as other polyfunctional phenol type epoxy resins, epoxy resins obtained by hydrogenating aromatic rings of aromatic epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, Examples include cyclic epoxy resins and heterocyclic epoxy resins. Among these, the bisphenol A type epoxy resin is preferable as the epoxy resin because it can be used in a wide range of applications and the manufacturing cost is low.

In order to adjust the glass transition temperature and crosslink density of the cured product, the epoxy resin preferably contains an epoxy resin having a linear aliphatic skeleton in its main chain.
The amount of the epoxy resin having a linear aliphatic skeleton in the main chain is preferably 10 to 90% by mass of the total epoxy resin, although it depends on the epoxy equivalent of other epoxy resins.

Examples of epoxy resins having a linear aliphatic skeleton in the main chain include alkanediol glycidyl ether, alkanediol diglycidyl ether, polyethylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether.

[Curing agent]
The curing agent (C) may be any curing agent that cures the resin (B) (specifically, the matrix resin). When the matrix resin is an epoxy resin, a known epoxy resin curing agent may be used. good.

Curing agents for epoxy resins are substances that contribute to cross-linking and/or chain extension reactions between the epoxy groups of the epoxy resin. In this specification, even if a substance is usually called a "curing accelerator", it is regarded as a curing agent if it is a substance that contributes to the cross-linking reaction and/or chain extension reaction between the epoxy groups of the epoxy resin. do.

The content of the curing agent in the curable resin composition is preferably 0.1 to 300 parts by mass, more preferably 250 parts by mass or less, even more preferably 200 parts by mass or less, with respect to 100 parts by mass of the epoxy resin. Part by mass or less is particularly preferred.

Curing agents for epoxy resins include, for example, polyfunctional phenols, amine compounds, acid anhydride compounds, imidazole compounds, amide compounds, cationic polymerization initiators, and organic phosphines.
Among these, amine-based compounds are preferred because polyrotaxanes are uniformly dispersed in the epoxy resin.

Examples of polyfunctional phenols include bisphenols, biphenols, catechol, resorcinol, hydroquinone, dihydroxynaphthalenes, and those in which hydrogen atoms bonded to aromatic rings of these compounds are substituted with substituents such as halogen. Further, polyfunctional phenols include novolaks and resoles.
These may be used individually by 1 type, and may use 2 or more types together.

Examples of amine compounds include aliphatic primary, secondary, and tertiary amines, aromatic primary, secondary, and tertiary amines, cyclic amines, guanidines, and urea derivatives. Specifically, triethylenetetramine, diaminodiphenylmethane, diaminodiphenyl ether, metaxylenediamine, dicyandiamide, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0] -5-nonene, dimethylurea, guanylurea.
These may be used individually by 1 type, and may use 2 or more types together.

From the viewpoint that the polyrotaxane can be more uniformly dispersed in the epoxy resin, it is preferable to use an amine-based compound as the curing agent, and it is more preferable to use diaminodiphenylmethane.

Acid anhydride compounds include, for example, phthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride, and condensates of maleic anhydride and unsaturated compounds.
These may be used individually by 1 type, and may use 2 or more types together.

Examples of imidazole compounds include 1-isobutyl-2-methylimidazole, 2-methylimidazole, 1-benzyl-2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and benzimidazole. .
These may be used individually by 1 type, and may use 2 or more types together.

Examples of amide compounds include dicyandiamide and its derivatives, and polyamide resins.
These may be used individually by 1 type, and may use 2 or more types together.

Examples of cationic polymerization initiators include anionic components such as SbF ₆ ⁻ , BF ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , CF ₃ SO ₃ ²⁻ and B(C ₆ F ₅ ) ₄ ⁻ , iodine, sulfur , nitrogen, and an aromatic cation component containing atoms such as phosphorus. Among these, diaryliodonium salts and triarylsulfonium salts are preferred.
These may be used individually by 1 type, and may use 2 or more types together.

Examples of organic phosphines include tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine.
These may be used individually by 1 type, and may use 2 or more types together.

When using polyfunctional phenols, amine compounds, and acid anhydride compounds, functional groups in the curing agent for epoxy groups in the curable resin composition (specifically, hydroxyl groups of polyfunctional phenols, amine compounds or the acid anhydride group of the acid anhydride-based compound) is preferably used so that the equivalent ratio is in the range of 0.8 to 1.5.

The content of polyrotaxane (A) in the curable resin composition is preferably 0.1 to 30% by mass. When the content of the polyrotaxane (A) is within the above range, the mechanical properties of the cured product of the curable resin composition are improved.

[Method for producing curable resin composition]
A curable resin composition may be prepared by mixing a polyrotaxane, a matrix resin and a curing agent by a common method in this field.

[Cured product]
A cured product can be obtained by curing the curable resin composition. The term "curing" as used herein means intentionally curing the curable resin composition with heat and/or light, and the degree of curing may be controlled according to desired physical properties and applications.

When the curable resin composition is an epoxy resin-based curable resin composition, the curing method (more specifically, the heating conditions for curing) varies depending on the ingredients and amounts in the composition, but usually , 80-200° C. for 60-180 minutes.
When the curing reaction is sufficiently advanced, primary heating at 80 to 160° C. for 10 to 30 minutes and secondary heating at 120 to 200° C., which is 40 to 120° C. higher than the primary heating temperature, for 60 to 150 minutes. It is preferable to carry out the two-stage treatment with.
When a cured product is produced as a semi-cured product, the curing reaction of the curable resin composition may be allowed to proceed by heating or the like to such an extent that the shape can be maintained.

[Physical properties of cured product]
The cured product has improved mechanical properties.
Mechanical properties can be measured by a tensile test, bending test, impact resistance test, or the like.
In the case of a tensile test, the tensile elongation at break is improved by increasing the toughness. At that time, it is particularly important that the tensile elastic modulus obtained from the elastic strain region in which the stress and strain in the tensile test are proportional does not decrease.

[Use]
Since the curable resin composition and the cured product have improved mechanical properties such as toughness and elasticity, they can be suitably used in fields such as paints, electrical and electronic materials, adhesives, and carbon fiber reinforced resins.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
In the following description, the unit "parts" indicates "mass parts".

[Evaluation method]
<Mechanical properties (uniaxial tensile test)>
Dumbbell-shaped test pieces (straight portion length 4 mm, straight portion width 16 mm, thickness 1 mm) obtained in Examples and Comparative Examples were measured using a precision universal testing machine Autograph AG-10kNXPlus (manufactured by Shimadzu Corporation). Then, a uniaxial tensile test was performed at room temperature (23°C).
The tensile modulus and tensile elongation at break were measured with an initial crosshead distance of 25 mm and a crosshead speed of 1 mm/min. Further, in Examples 6 to 14, Comparative Examples 2 and 3, the maximum stress at this time was measured.
The tensile modulus is obtained as the slope of the stress-strain curve between two points of strain 0.05% and 0.25%. The tensile elongation at break is obtained as a value obtained by dividing the distance extended from the start of the test to the time of break by the initial distance between the crossheads. The maximum stress is obtained as the maximum of the stresses exhibited from the start of the test to the time of break.

[material]
Preparation of polycaprolactone-modified hydroxypropylated polyrotaxane (a1) Prepared in the same manner as described in paragraphs 0035 to 0037 of Japanese Patent No. 4461252 and paragraphs 0072 to 0073 of JP-A-2011-046917. The structure of the polycaprolactone-modified hydroxypropylated polyrotaxane (a1) is as follows.
Linear molecule: polyethylene glycol (number average molecular weight 20,000 g/mol)
Cyclic molecule: α-cyclodextrin (hereinafter "cyclodextrin" is abbreviated as "CD")
Sealing group: adamantaneamine group CD modifying group: polycaprolactone (around 8 repeating structural units)
α-CD inclusion amount: 0.28
Number of polycaprolactones per α-CD: about 5
Overall weight average molecular weight: 200,000 g/mol

Preparation of hydroxypropylated polyrotaxane (a2) Prepared in the same manner as described in WO2005/080469. The structure of the hydroxypropylated polyrotaxane (a2) is as follows.
Linear molecule: Polyethylene glycol (average molecular weight 35,000)
Cyclic molecule: α-CD
Blocking group: adamantaneamine group α-CD inclusion amount: 0.25
Hydroxypropyl group modification rate: 51%
Theoretical amount of hydroxyl groups: 9.76 mmol/g
Weight average molecular weight by gel permeation chromatography (GPC): 150,000

Epoxy resin (b1): jER (registered trademark) 828 (bisphenol A liquid epoxy resin, manufactured by Mitsubishi Chemical Corporation)
Epoxy resin (b2): YED216D (alkyl diglycidyl ether, manufactured by Mitsubishi Chemical Corporation)
Curing agent (c): 4,4'-diaminodiphenylmethane (manufactured by Tokyo Chemical Industry Co., Ltd.)

[Example 1] Introduction of epoxy group to (a1) 10 g of polycaprolactone-modified hydroxypropylated polyrotaxane (a1) was dissolved in 80 mL of toluene and stirred for 4 hours, followed by 1,8-diazabicyclo[5.4.0]undeca. -7-ene 0.96 mL was added and mixed for an additional hour.
0.63 mL of epibromohydrin was added thereto and reacted at 50° C. for 24 hours.
Toluene was distilled off from the resulting synthesis solution, and the solution was dissolved and reprecipitated with chloroform/hexane two or three times, and dried under reduced pressure at 60° C. for 24 hours to obtain a white solid.
NMR measurement confirmed the structure of epoxy group-modified polyrotaxane (A1) in which about 30% of epoxy groups were modified with respect to hydroxyl groups derived from polycaprolactone.
Epoxy groups are attached to the ends of polycaprolactone via ether groups.

The obtained epoxy group-modified polyrotaxane (A1): 20 parts, epoxy resin (b1): 60 parts, and epoxy resin (b2): 40 parts were mixed at 80° C. for 1 hour, and then the curing agent (c): 32.7. and melted at 85° C. to obtain a curable resin composition.
The obtained curable resin composition was placed in a dumbbell-shaped silicone mold (dumbbell No. 8 test piece, length of straight part 4 mm, width of straight part 16 mm, thickness 1 mm), and the pressure was reduced at 80 ° C. for 10 minutes. Degassed below. Thereafter, the temperature was raised from room temperature at a rate of 6° C./min under atmospheric pressure to reach 90° C., and then held for 15 minutes.
Then, after the temperature was raised at a rate of 6° C./min to reach 150° C., the composition was thermally cured by holding for 2 hours to obtain a cured product.

[Comparative Example 1]
Polyrotaxane (a1) not modified with an epoxy group (that is, unmodified polyrotaxane (a1), more specifically, polycaprolactone-modified hydroxypropylated polyrotaxane (a1)): 20 parts, epoxy resin (b1): 60 and epoxy resin (b2): 40 parts were mixed at 80° C. for 1 hour, and then cured in the same manner as in Example 1 to obtain a cured product.

[Comparative Example 2]
Epoxy resin (b1): 60 parts and epoxy resin (b2): 40 parts were mixed at 80° C. for 1 hour, and then cured in the same manner as in Example 1 to obtain a cured product.

From Table 1, the cured product of Example 1 using polyrotaxane having an external stimulus-reactive ring-opening functional group exhibits a high tensile elongation at break without impairing the inherent tensile modulus of the epoxy resin. In other words, it was found that the cured product of Example 1 had both elastic modulus and elongation, and had very excellent mechanical properties.

On the other hand, the cured product of Comparative Example 1 using a polyrotaxane not modified with an epoxy group exhibited a high tensile elongation at break, but a low tensile modulus and could not maintain the original tensile modulus of the epoxy resin. I understood it.
The cured product of Comparative Example 2, which did not use polyrotaxane, exhibited a high tensile modulus, but a low tensile elongation at break and poor toughness.

Examples 2 to 5 below are examples of producing polyrotaxanes different from Example 1.

[Example 2] Introduction of epoxy group to (a2) Under a nitrogen atmosphere, 40 mL of dehydrated DMSO (DMSO represents dimethyl sulfoxide) was added to 1000 mg of hydroxypropylated polyrotaxane (a2), and the mixture was stirred at 60°C. Dissolved. As the hydroxypropylated polyrotaxane (a2), one dried under reduced pressure in advance was used. Then, 1582 mg (9.76 mmol) of 1,1′-carbonyldiimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the dissolved material, and the mixture was stirred at 60° C. for 2 hours.
238 mg (1.95 mmol) of N,N-dimethylaminopyridine (manufactured by Tokyo Kasei Co., Ltd.) and 1445 mg (19.5 mmol) of glycidol (manufactured by Kanto Kagaku Co., Ltd.) were added and stirred at 60° C. for 2 hours. After cooling to room temperature, an aqueous solution prepared by dissolving 29.3 mmol of sodium dihydrogen phosphate in 40 mL of water was poured little by little, and the deposited precipitate was obtained by decantation.
The precipitate was reprecipitated with DMSO (15 mL)-water (15 mL) three times, and then reprecipitated with chloroform (15 mL)-hexane (15 mL) eight times. The resulting precipitate was dissolved in chloroform (30 mL) and then filtered. The resulting solution was dried over anhydrous sodium sulfate and filtered to obtain a colorless solution.

Using 2073 mg of hydroxypropylated polyrotaxane (a2) as a starting material, the same operation as above was performed to obtain another colorless solution.

By mixing the two colorless solutions obtained as described above and partially concentrating the solvent, 89.2 g of a chloroform solution containing 725 mg of the target epoxy group-modified polyrotaxane (A2) was obtained ( concentration 0.81% by weight). In the proton NMR measured in DMSO-d ₆ , OH estimated from the integration of the peak derived from the epoxy group at 2.9 ppm based on the integration of the methyl group peak derived from the hydroxypropyl group at 1.0-1.2 ppm. The epoxidation rate of the groups was about 40%.

It can be said that the epoxy group-modified polyrotaxane (A2) of this example has the following structure.
A glycidyl group is bonded to the α-CD ring, which is a cyclic molecule, via a carbonate bond, and the modification rate is about 40%. More specifically, the hydroxypropylated polyrotaxane (a2) used as a raw material has 18 hydroxyl groups (including hydroxypropylated ones) per α-CD ring. , and about 40% of the hydroxyl groups on average are replaced with glycidyl carbonate groups.

[Example 3] Introduction of epoxy group and benzyl group to (a2) Under a nitrogen atmosphere, 21 mL of dehydrated DMSO was added to 516 mg of hydroxypropylated polyrotaxane (a2), and the mixture was stirred at 60°C to dissolve. As the hydroxypropylated polyrotaxane (a2), one dried under reduced pressure in advance was used. Then, 816 mg (5.04 mmol) of 1,1′-carbonyldiimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the dissolved material, and the mixture was stirred at 60° C. for 2 hours.
The temperature is raised to 80° C., 62 mg (0.50 mmol) of N,N-dimethylaminopyridine (manufactured by Tokyo Kasei Co., Ltd.) and 1089 mg (10.1 mmol) of benzyl alcohol (manufactured by Tokyo Kasei Co., Ltd.) are added, and the mixture is stirred at 80° C. for 2 hours. did. After cooling to 60°C, 746 mg (10.1 mmol) of glycidol (manufactured by Kanto Kagaku Co., Ltd.) was added and stirred at 60°C for 1 hour. After cooling to room temperature, the reaction solution was gradually poured into 21 mL of ice-cooled water, and the deposited precipitate was collected by decantation.
The precipitate was reprecipitated with DMSO (6 mL)-water (6 mL) three times, and then reprecipitated with chloroform (3 mL)-hexane (6 mL) three times. The resulting precipitate was dissolved in chloroform (20 mL) and then filtered. The resulting solution was dried over anhydrous sodium sulfate and filtered to obtain a colorless solution.

Using 518 mg, 479 mg, 490 mg and 517 mg of hydroxypropylated polyrotaxane (a2) as starting materials, the same operation as above was performed to obtain four colorless solutions.

By mixing the five solutions obtained as described above and partially concentrating the solvent, 36.2 g of a chloroform solution containing 1090 mg of the target epoxy group-modified polyrotaxane (A3) was obtained (concentration: 3 .0% by weight). In the proton NMR measured in DMSO-d ₆ , OH estimated from the integration of the peak derived from the epoxy group at 2.9 ppm based on the integration of the methyl group peak derived from the hydroxypropyl group at 1.0-1.2 ppm. The epoxidation rate of the group was about 21%, and the benzylation rate of the OH group was about 41% as estimated from the integration of the peak derived from the benzyl group at 5.1-5.2 ppm.

It can be said that the epoxy group-modified polyrotaxane (A3) of this example has the following structure.
A glycidyl group and a benzyl group are bonded to the α-CD ring, which is a cyclic molecule, via a carbonate bond, and their modification rates are about 21% and 41%, respectively. More specifically, the hydroxypropylated polyrotaxane (a2) used as a raw material has 18 hydroxyl groups (including hydroxypropylated ones) per α-CD ring. , about 21% of the hydroxyl groups on average are replaced by glycidyl carbonate groups, and further, about 41% on average are replaced by benzyl carbonate groups.

[Example 4] Introduction of epoxy group and benzyl group to (a2) Under nitrogen atmosphere, 21 mL of dehydrated DMSO was added to 533 mg of hydroxypropylated polyrotaxane (a2), and stirred at 60°C to dissolve. As the hydroxypropylated polyrotaxane (a2), one dried under reduced pressure in advance was used. Next, 842 mg (5.20 mmol) of 1,1′-carbonyldiimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the dissolved material, and the mixture was stirred at 60° C. for 2 hours.
The temperature is raised to 80° C., 63 mg (0.52 mmol) of N,N-dimethylaminopyridine (manufactured by Tokyo Kasei Co., Ltd.) and 2247 mg (20.8 mmol) of benzyl alcohol (manufactured by Tokyo Kasei Co., Ltd.) are added, and the mixture is stirred at 80° C. for 2 hours. did. After cooling to 60°C, 770 mg (10.4 mmol) of glycidol (manufactured by Kanto Kagaku Co., Ltd.) was added and stirred at 60°C for 1 hour. After cooling to room temperature, the reaction solution was gradually poured into 21 mL of ice-cooled water, and the deposited precipitate was obtained by decantation.
The precipitate was reprecipitated with DMSO (6 mL)-water (6 mL) three times, and then reprecipitated with chloroform (1 mL)-hexane (3 mL) seven times. The resulting precipitate was dissolved in chloroform (20 mL) and then filtered. The resulting solution was dried over anhydrous sodium sulfate and filtered to obtain a colorless solution.

Using 535 mg and 493 mg of hydroxypropylated polyrotaxane (a2) as starting materials, the same operation as above was carried out to obtain two more colorless solutions.

By mixing the three solutions obtained as described above and partially concentrating the solvent, 49.8 g of a chloroform solution containing 1372 mg of the target epoxy group-modified polyrotaxane (A4) was obtained (concentration: 2 .75% by weight). In the proton NMR measured in DMSO-d ₆ , OH estimated from the integration of the peak derived from the epoxy group at 2.9 ppm based on the integration of the methyl group peak derived from the hydroxypropyl group at 1.0-1.2 ppm. The epoxidation rate of the group was about 9%, and the benzylation rate of the OH group was about 57% as estimated from the integration of the peak derived from the benzyl group at 5.1-5.2 ppm.

It can be said that the epoxy group-modified polyrotaxane (A4) of this example has the following structure.
A glycidyl group and a benzyl group are bonded to the α-CD ring, which is a cyclic molecule, via a carbonate bond, and their modification rates are about 9% and 57%, respectively. More specifically, the hydroxypropylated polyrotaxane (a2) used as a raw material has 18 hydroxyl groups (including hydroxypropylated ones) per α-CD ring. , about 9% of the hydroxyl groups on average are replaced by glycidyl carbonate groups, and further, about 57% on average of these hydroxyl groups are replaced by benzyl carbonate groups.

[Example 5] Introduction of epoxy group and 2-(2-methoxyethoxy)ethyl group to (a2) Under a nitrogen atmosphere, 10 mL of dehydrated DMSO was added to 242 mg of hydroxypropylated polyrotaxane (a2), and the mixture was stirred at 60°C. to dissolve. As the hydroxypropylated polyrotaxane (a2), one dried under reduced pressure in advance was used. Then, 383 mg (2.36 mmol) of 1,1′-carbonyldiimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the dissolved material, and the mixture was stirred at 60° C. for 2 hours.
The temperature was raised to 80° C., N,N-dimethylaminopyridine (manufactured by Tokyo Kasei Co., Ltd.) 29 mg (0.24 mmol) and diethylene glycol monomethyl ether (manufactured by Tokyo Kasei Co., Ltd.) 852 mg (7.09 mmol) were added, and the mixture was heated at 80° C. for 2 hours. Stirred. After cooling to 60° C., 350 mg (4.73 mmol) of glycidol (manufactured by Kanto Kagaku Co., Ltd.) was added and stirred at 60° C. for 1 hour. After cooling to room temperature, the reaction solution was gradually poured into 10 mL of ice-cooled water, and the deposited precipitate was collected by decantation.
The precipitate was reprecipitated with DMSO (3 mL)-water (3 mL) three times, and then reprecipitated with chloroform (0.5 mL)-hexane (1.5 mL) six times. The resulting precipitate was dissolved in chloroform (20 mL) and then filtered. The resulting solution was dried over anhydrous sodium sulfate and filtered to obtain a colorless solution.

Using 517 mg, 524 mg and 518 mg of hydroxypropylated polyrotaxane (a2) as starting materials, the same operation as above was performed to obtain three colorless solutions.

By mixing the four solutions obtained as described above and partially concentrating the solvent, 60.7 g of a chloroform solution containing 1281 mg of the target epoxy group-modified polyrotaxane (A5) was obtained (concentration: 2 .1% by weight). In the proton NMR measured in DMSO-d ₆ , OH estimated from the integration of the peak derived from the epoxy group at 2.9 ppm based on the integration of the methyl group peak derived from the hydroxypropyl group at 1.0-1.2 ppm. The epoxidation rate of the group was about 33%, and the 2-(2-methoxyethoxy)ethylation rate of the OH group estimated from the integration of the peak of the methoxy group at 3.4 ppm was about 23%.

It can be said that the epoxy group-modified polyrotaxane (A5) of this example has the following structure.
A glycidyl group and a 2-(2-methoxyethoxy)ethyl group are bonded to the α-CD ring, which is a cyclic molecule, via a carbonate bond, and their modification rates are about 33% and 23%, respectively. . More specifically, the hydroxypropylated polyrotaxane (a2) used as a raw material has 18 hydroxyl groups (including hydroxypropylated ones) per α-CD ring. , about 33% of the hydroxyl groups on average are replaced by glycidyl carbonate groups, and further, about 23% on average are replaced by 2-(2-methoxyethoxy)ethyl carbonate groups. .

Examples 6 to 14 below are examples in which cured products are produced using the polyrotaxanes of Examples 2 to 5, respectively, and evaluated. The evaluation was carried out by performing the above-mentioned uniaxial tensile test and measuring the maximum stress, tensile modulus and tensile elongation at break.

[Example 6]
Solution of epoxy group-modified polyrotaxane (A2): 1 part in terms of solid content, epoxy resin (b1): 60 parts, and epoxy resin (b2): 40 parts were mixed. After that, chloroform was distilled off under reduced pressure, and then mixed at 80° C. for 1 hour. Next, the curing agent (c) was added and dissolved at 85° C. to obtain a curable resin composition. As shown in Table 2, the amount of the curing agent (c) was such that the amount of active hydrogen in the curing agent (c) was equal to the total amount of epoxy groups possessed by the epoxy resin and the polyrotaxane.
A cured product was obtained in the same manner as in Example 1 using the obtained curable resin composition.

[Example 7]
Solution of epoxy group-modified polyrotaxane (A2): A cured product was obtained in the same manner as in Example 6, except that 5 parts in terms of solid content was used.

[Example 8]
Solution of epoxy group-modified polyrotaxane (A3): A cured product was obtained in the same manner as in Example 6, except that 1 part in terms of solid content was used.

[Example 9]
Solution of epoxy group-modified polyrotaxane (A3): A cured product was obtained in the same manner as in Example 6, except that 5 parts in terms of solid content were used.

[Example 10]
Solution of epoxy group-modified polyrotaxane (A4): A cured product was obtained in the same manner as in Example 6, except that 1 part in terms of solid content was used.

[Example 11]
Solution of epoxy group-modified polyrotaxane (A4): A cured product was obtained in the same manner as in Example 6, except that 5 parts in terms of solid content were used.

[Example 12]
Solution of epoxy group-modified polyrotaxane (A5): A cured product was obtained in the same manner as in Example 6, except that 1 part in terms of solid content was used.

[Example 13]
Solution of epoxy group-modified polyrotaxane (A5): A cured product was obtained in the same manner as in Example 6, except that 5 parts in terms of solid content were used.

[Example 14]
Solution of epoxy group-modified polyrotaxane (A5): A cured product was obtained in the same manner as in Example 6, except that 10 parts in terms of solid content was used.

[Comparative Example 3]
Polyrotaxane not modified with epoxy group (a1): 10 parts, epoxy resin (b1): 60 parts, epoxy resin (b2): 40 parts were mixed at 80 ° C. for 1 hour, and cured in the same manner as in Example 6. got stuff

As can be seen from Table 2, the cured products of Examples 6 to 14 using polyrotaxanes having an external stimulus-reactive ring-opening functional group are all high in tensile elasticity when compared with Comparative Example 2 that does not use polyrotaxane. modulus and maximum stress are given. In other words, it was found that by using a polyrotaxane having an external stimulus-reactive ring-opening functional group, the excellent mechanical properties inherent in epoxy resins can be further improved. Furthermore, among Examples 6 to 14, the cured products of Examples 6, 8, and 10 to 14 exhibited high tensile elongation at break and were found to have excellent mechanical properties.
On the other hand, the cured product of Comparative Example 3 using polyrotaxane not modified with epoxy groups exhibited a high tensile elongation at break, but had a low tensile modulus and maximum stress, maintaining the original tensile modulus of the epoxy resin. It turned out that it wasn't.

Claims (18)

a linear molecule;
a cyclic molecule that clathrates the linear molecule in a skewered manner;
and a blocking group arranged at both ends of the linear molecule,
The polyrotaxane, wherein the cyclic molecule has an external stimulus-reactive ring-opening functional group composed of a cyclic aliphatic ether and/or a cyclic aliphatic thioether. 2. The polyrotaxane according to claim 1, wherein the cyclic molecule has a cyclic main chain, a side chain linked to the main chain, and the external stimuli-responsive ring-opening functional group linked to the side chain. 3. The polyrotaxane according to claim 2, wherein the side chain of the cyclic molecule has an ether group, and the cyclic molecule has the external stimulus-reactive ring-opening functional group linked to the side chain via the ether group. . 4. The polyrotaxane according to claim 2, wherein the side chain of said cyclic molecule is composed of polyester. 4. The polyrotaxane according to claim 2, wherein the side chain of said cyclic molecule is composed of polycaprolactone. 6. The polyrotaxane according to any one of claims 1 to 5, wherein the external stimuli-reactive ring-opening functional group is an epoxy group and/or an oxetane group. 7. The polyrotaxane according to claim 6, wherein the external stimuli-reactive ring-opening functional group is an epoxy group. The cyclic molecule has a cyclic main chain, a side chain linked to the main chain, and the external stimuli-responsive ring-opening functional group linked to the side chain, and the side chain has a molecular weight of less than 500. The polyrotaxane of claim 1, wherein wherein the side chain of the cyclic molecule has an ether bond, a carbonate bond, or a carbamate bond, and the external stimulation-responsive ring-opening functional group is linked to the side chain via the bond; Item 8. The polyrotaxane according to item 8. 10. The polyrotaxane according to claim 8 or 9, wherein the cyclic molecule has the external stimulus-reactive ring-opening functional group directly linked to the main chain via a carbonate bond. 11. The polyrotaxane according to any one of claims 8 to 10, wherein the number of external stimulation-reactive ring-opening functional groups per cyclic molecule is 0.1 to 9. The polyrotaxane according to any one of claims 8 to 11, wherein the external stimuli-reactive ring-opening functional group is an epoxy group and/or an oxetane group. 13. The polyrotaxane according to claim 12, wherein the external stimuli-reactive ring-opening functional group is an epoxy group. The polyrotaxane (A) according to any one of claims 1 to 13,
a resin (B) capable of reacting with the external stimulus-reactive ring-opening functional group of the polyrotaxane;
A curable resin composition comprising a curing agent (C). The curable resin composition according to claim 14, comprising 0.1 to 30% by mass of the polyrotaxane (A). 16. The curable resin composition according to claim 14 or 15, wherein the external stimulus-reactive ring-opening functional group is an epoxy group, and the resin (B) is an epoxy resin. 17. The curable resin composition according to claim 16, wherein the epoxy resin contains an epoxy resin having a linear aliphatic skeleton in the main chain constituting the epoxy resin. A cured product obtained by curing the curable resin composition according to any one of claims 15 to 17.