Toughening of silicone-based polymer material with addition of polyrotaxane

Abstract

To provide a composition in which a silicone-based polymer material and a plurality of polyrotaxanes are well mixed or dispersed.SOLUTION: Provided is a composition which contains: a silicone-based polymer material; and a plurality of polyrotaxanes, wherein each polyrotaxane has a plurality of cyclic molecules and a chain polymer that penetrates through the openings of the plurality of cyclic molecules, with a polysiloxane chain bonded to at least some of the plurality of cyclic molecules.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a composition containing a silicone-based polymer material and a plurality of polyrotaxanes, and a method for producing the same. [Background technology]

[0002] Silicone polymer materials, including silicone rubber, have excellent heat resistance, weather resistance, and water resistance, and are therefore used in a wide range of applications, including electrical and electronic materials, automobiles, and building materials, as sealing materials, heat dissipation materials, and shock absorbing materials. However, they have poor tear properties.

[0003] It is known that polyrotaxanes improve the mechanical properties of polymers, such as toughness and extensibility, when blended with the polymer. Polyrotaxanes are compatible with polymeric materials having a certain degree of polarity, such as polyamides, polyesters, and polyacrylates, and are easy to exhibit their effects, but are not compatible with polymeric materials having low polarity, such as silicone-based polymers, fluorine-based polymers, and polyolefins. If silicone-based polymers could be composited with polyrotaxanes, the resulting polymer blends could be made tough, but such composites have been difficult in the past from the standpoint of compatibility.

[0004] Meanwhile, a crosslinkable material that maintains a certain number of crosslinking points through an associative dynamic covalent bond is known as a vitrimer, and various dynamic covalent bond exchange modes are currently known (Non-Patent Document 1). Examples of vitrimers containing siloxanes have been reported: an epoxy vitrimer synthesized using a polysiloxane oligomer called bis(potassium) oligoaminopropylmethylsiloxane diolate (K-PAMS) as a curing agent for epoxy resin (Non-Patent Document 2), a vitrimer synthesized using 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (BAS) and bisphenol A diglycidyl ether (DGEBA) as starting materials and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as an organic catalyst (Non-Patent Document 3), and a styrene-based copolymer crosslinked with a bisalkoxysilane crosslinker in which the introduction of adjacent amino moieties accelerates the silyl ether exchange rate (Non-Patent Document 4). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Jie Zheng et al., Volume 51, December 2021, Pages 586-625 DOI: 10.1016 / j.mattod.2021.07.003 [Non-Patent Document 2] Xiao Wu, et al., J. Mater. Chem. A, 2018, 6, 10184 DOI: 10.1039 / c8ta02102c [Non-Patent Document 3] Tapas Debsharma et al., J.Am. Chem. Soc. 2022, 144, 12280-12289 DOI: 10.1021 / jacs.2c03518 [Non-Patent Document 4] J. Am. Chem. Soc. 2017. 139, 14881-14884 Summary of the Invention [Problem to be solved by the invention]

[0006] The problem to be solved by the present invention is to provide a composition in which a silicone-based polymer material and a plurality of polyrotaxanes are well mixed or dispersed. A further problem to be solved by the present invention is to provide a composition in which a silicone-based polymer material and a plurality of polyrotaxanes are well mixed or dispersed and which has improved mechanical strength. [Means for solving the problem]

[0007] The present invention encompasses the embodiments described below.

[0008] Section 1. A silicone polymer material; a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules; A composition comprising: Section 2. -Si-OR in the silicone polymer material 1 (R 1 2. The composition according to item 1, wherein a bond exchange reaction occurs by heating between the cyclic molecule of the polyrotaxane and a silanol group or a metal silanolate group of the polysiloxane chain bonded to the cyclic molecule of the polyrotaxane. Section 3. Item 3. The composition according to item 1 or 2, further comprising a bond exchange catalyst. Section 4. Item 3. The composition according to item 2, which is a transparent composition. Section 5. Item 3. The composition according to item 1 or 2, wherein the silicone-based polymer material contains a silicone elastomer. Section 6. Item 3. The composition according to item 1 or 2, wherein the silicone-based polymer material contains a poly(dimethylsiloxane) skeleton. Section 7. Item 2. The composition according to item 1, wherein the content of the polyrotaxane in the composition is from 0.1% by mass to 99.9% by mass. Section 8. 1. A method for producing a composition comprising a silicone-based polymer material and a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules, the method comprising the steps of: mixing the silicone-based polymeric material and the plurality of polyrotaxanes in the presence of a bond exchange catalyst. Section 9. A method for producing a composition comprising a silicone-based polymer material and a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules, the silicone-based polymer material comprising a silicone elastomer which is a crosslinked product of a base material and a crosslinking agent, the method comprising: mixing the base agent, the crosslinking agent, and the plurality of polyrotaxanes in the presence of a crosslinking catalyst to crosslink the base agent and the crosslinking agent. Section 10. Item 10. The method according to item 9, further comprising reacting a plurality of cyclic molecules of each of the polyrotaxanes with cyclic dimethylsiloxane before the crosslinking to form a plurality of polyrotaxanes in which a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules. Section 11. The composition is further heated in the presence of a bond exchange catalyst to convert -Si-OR 1 (R 1 Item 10. The method according to item 9, further comprising causing a bond exchange reaction between the metal silanolate group or the metal silanolate group of the polysiloxane chain in the polyrotaxane. Effect of the Invention

[0009] According to the present invention, there is provided a composition in which a silicone-based polymer material and a plurality of polyrotaxanes are well mixed or dispersed. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram illustrating bond exchange between silyl ether (—Si—O—Si—) and silanol (—Si—OH) in a composition containing a silicone-based polymer material and a polysiloxane-graft polyrotaxane. [Diagram 2] 1 is a scheme illustrating the reaction of attaching polysiloxane to cyclodextrin. [Diagram 3] GPC measurement of PDMS-PR-1. [Figure 4] 1H-NMR spectrum of PDMS-grafted polyrotaxane. [Diagram 5] Photographs of various cross-linked films. [Figure 6] Stress-strain curves of various films. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] As used herein, "polymer" refers to a compound having a repeating structure consisting of multiple basic units derived from the polymerization of monomers. "Polymer" includes "resin."

[0012] In this specification, "resin" includes natural resins and synthetic resins, and "resin" includes elastomers and rubbers.

[0013] In this specification, the term "comprise" is a concept that encompasses "consist essentially of" and "consist only of."

[0014] In the numerical ranges described in stages in this specification, the upper or lower limit of a certain numerical range can be arbitrarily combined with the upper or lower limit of another numerical range. In addition, in the numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with a value shown in an example or a value that can be unambiguously derived from an example. Furthermore, in this specification, a numerical value connected with "~" means a numerical range that includes the numerical values ​​before and after "~" as the lower and upper limits.

[0015] Hereinafter, an embodiment of the present invention will be described.

[0016] In synthesizing silicone-based polymer materials and polyrotaxanes, the inventors focused on bond exchange between silyl ethers (-Si-O-Si- or -Si-OC-) of vitrimers containing siloxanes and silanol groups (-Si-OH) or metal silanolate groups (-Si-OM, where M is a metal).

[0017] By grafting polysiloxane onto the cyclic molecules of polyrotaxane, good mixing of the polysiloxane graft polyrotaxane with the silicone polymer material is realized. In addition, by promoting the bond exchange between the silicone polymer material and the siloxane graft polyrotaxane, phase separation of the siloxane graft polyrotaxane in the matrix of the silicone polymer material is suppressed, and more uniform dispersion than physical mixing is possible.

[0018] According to one aspect of the present invention, there is provided a composition containing a silicone-based polymer material and a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain-like polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules.

[0019] As shown in Fig. 1 as a schematic diagram for the purpose of facilitating understanding, the composition according to the embodiment of the present invention contains a silicone polymer material 1 and a plurality of polyrotaxanes 2 (only one is shown in the figure). The polyrotaxane 2 comprises a plurality of cyclic molecules 3 and a chain polymer 4 that passes through the openings of the plurality of cyclic molecules 3, and blocking groups 5 are bonded to both ends of the chain polymer 4 to prevent the cyclic molecules 3 from falling off from the chain polymer 4. A polysiloxane chain 6 is bonded to at least a portion of the plurality of cyclic molecules 3. An end 7 of the polysiloxane chain 6 is a hydroxyl group or a metal alkoxide.

[0020] A bond exchange reaction of silyl ether (-Si-O-Si- or -Si-OC-) in the silicone polymer material 1 occurs between the silyl ether and -Si-OH or -Si-OM (M is a metal) at the end 7 of the polysiloxane chain 6 bonded to the cyclic molecule 3 of the polyrotaxane 2, and the compatibility between the silicone polymer material 1 and the polyrotaxane 2 is increased. M is particularly an alkali metal such as lithium, potassium, or sodium. When the composition is heated, the bond exchange reaction is further promoted. This is thought to improve the mechanical strength (e.g., toughness) of the vitrimer compared to a composition of the silicone polymer material 1 and a polyrotaxane to which the polysiloxane chain 6 is not grafted.

[0021] In some embodiments, the silicone-based polymer material is a silicone resin. Silicone resin refers to a thermosetting resin whose main component is silicone, which is a polymer having a main skeleton composed of siloxane bonds. Silicone resins include silicone rubber that exhibits elasticity. In some embodiments, the silicone-based polymeric material is an organopolysiloxane, such as an organopolysiloxane represented by the following formula (Formula I). [ka]

[0022] In the formula, R 1is preferably an unsubstituted or substituted monovalent hydrocarbon group having preferably 1 to 20 carbon atoms, more preferably 1 to 6 carbon atoms, such as a straight-chain alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, or an eicosyl group; Examples of the branched alkyl groups include butyl, isobutyl, 2-methylundecyl, and 1-hexylheptyl; cyclic alkyl groups include cyclopentyl, cyclohexyl, and cyclododecyl; alkenyl groups include vinyl, allyl, butenyl, pentenyl, and hexenyl; aryl groups include phenyl, tolyl, and xylyl; aralkyl groups include benzyl, phenethyl, and 2-(2,4,6-trimethylphenyl)propyl; halogenated alkyl groups include 3,3,3-trifluoropropyl and 3-chloropropyl; and alkyl groups substituted with a cyano group. Preferred are alkyl groups, alkenyl groups, and aryl groups, and particularly preferred are methyl, vinyl, and phenyl groups. The multiple substituents may be different or the same. The letter a is a number ranging from 1.9 to 2.4, preferably from 1.95 to 2.05.

[0023] In some embodiments, it is preferred that the silicone-based polymer material contains a poly(dimethylsiloxane) backbone in terms of compatibility with polyrotaxane. The average degree of polymerization of the organopolysiloxane is preferably 100-3,000.

[0024] In some embodiments, the silicone-based polymeric material comprises a silicone elastomer. Silicone elastomer is synonymous with "organopolysiloxane elastomer" and means a viscoelastic and deformable organopolysiloxane. Silicone elastomer is preferably a viscoelastic and deformable crosslinked organopolysiloxane. Silicone elastomer can return to its original shape after stretching, i.e., it can be elastically deformed.

[0025] Examples of silicone elastomers include those obtained by a condensation reaction between a methoxysilyl group (≡SiOCH3) and a hydroxysilyl group (≡SiOH), a condensation reaction between a hydrosilyl group (≡SiH) and a hydroxysilyl group (≡SiOH), a radical reaction between a mercaptopropylsilyl group (≡Si-CH3H6SH) and a vinylsilyl group (≡SiCH=CH2), and an addition reaction between a vinylsilyl group (≡SiCH=CH2) and a hydrosilyl group (≡SiH). From the viewpoint of reactivity, it is preferable to use a condensation reaction or an addition reaction. These reactions are preferably carried out in the presence of a crosslinking catalyst. Examples of the crosslinking catalyst include platinum catalysts such as platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex.

[0026] The molecular weight of the silicone polymer material, silicone elastomer, or organosiloxane is not particularly limited, and may be, for example, 500 to 1,000,000 in terms of number average molecular weight or weight average molecular weight. The polyrotaxane used in the present disclosure includes a polysiloxane-grafted polyrotaxane comprising a plurality of cyclic molecules and a chain polymer passing through the openings of the plurality of cyclic molecules, and in which a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules.

[0027] Polyrotaxane is a compound having a structure including a plurality of cyclic molecules and a chain polymer penetrating the openings of the plurality of cyclic molecules, and a blocking group is bonded to both ends of the chain polymer to prevent the cyclic molecules from falling off. Polyrotaxane may be produced based on known literature, or a commercially available product from a manufacturer such as ASM Inc. may be used.

[0028] The chain polymer constituting the polyrotaxane includes a molecule that can penetrate the inside of the rings of a plurality of cyclic molecules. The chain polymer is preferably a polymer having a repeating unit of a monomer. Examples of the chain polymer include polyalkylenes, polyesters, polyethers, polyamides, polyacrylics, and chain polymers having a benzene ring. Examples of preferred chain polymers include polyethylene glycol, polyethylene oxide, polypropylene glycol, polylactic acid, polycaprolactone, polyethylene, polypropylene, polyvinyl acetal, polyvinyl methyl ether, polyvinyl pyrrolidone, polyacrylamide, polymethyl acrylate, polymethyl methacrylate, and polystyrene. The chain polymer preferably does not have an ester bond, but may have an ester bond as long as the effect of the present invention is achieved. The chain polymer may have a branched chain as long as it is configured to be able to penetrate the inside of the rings of the cyclic molecules. In one preferred embodiment, the chain polymer is at least one selected from the group consisting of polyethylene glycol, polyvinyl alcohol, polyethyleneimine, and copolymers containing at least one of these. In a more preferred embodiment, the chain polymer is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polyethylene glycol.

[0029] The linear polymer may be a polymer whose entire structure is a repeating structure of the same monomer, or it may be a block copolymer having at least two blocks, or it may be a block copolymer having at least three blocks.

[0030] For example, when the chain polymer is a water-soluble chain molecule consisting of one type of polymer, it may be a polymer consisting of only polyethylene glycol, only polypropylene glycol, only polyvinyl alcohol, only polyethyleneimine, or only polyethylene glycol.When the chain polymer is a chain polymer consisting of three blocks, the central block may be polypropylene glycol and both sides may be polyethylene glycol.

[0031] The molecular weight of the chain polymer is not particularly limited, but the number average molecular weight is, for example, more preferably 3000 to 50000, more preferably 7000 to 200000, and even more preferably 10000 to 100000. Alternatively, the weight average molecular weight is, for example, more preferably 3000 to 500000, more preferably 7000 to 200000, and even more preferably 10000 to 100000. The number average molecular weight and weight average molecular weight referred to in this specification can be determined from polyethylene glycol equivalent values ​​measured by gel permeation chromatography (GPC).

[0032] Both ends of the chain polymer preferably have reactive groups capable of reacting with blocking groups for preventing cyclic molecules from falling off the chain polymer, which makes it easier for the blocking groups described below to be bonded to both ends of the chain polymer. Examples of reactive groups include amino groups, hydroxyl groups, carboxyl groups, thiol groups, disulfides, vinyl groups, acryloyl groups, methacryloyl groups, and sulfo groups. Preferred are amino groups and carboxyl groups.

[0033] The blocking group bonded to the linear polymer of polyrotaxane is not particularly limited as long as it acts to prevent the detachment of the cyclic molecule from the linear polymer. For example, the blocking group may be selected from the group consisting of a dinitrophenyl group, cyclodextrin, adamantane group, trityl group, fluorescein, silsesquioxane, pyrene, substituted benzene (substituents include, but are not limited to, alkyl, alkyloxy, hydroxy, halogen, cyano, sulfonyl, carboxyl, amino, phenyl, etc., and one or more substituents may be present), optionally substituted polynuclear aromatics (substituents include, but are not limited to, the same as those described above, and one or more substituents may be present), and steroids. It is preferable to select from the group consisting of a dinitrophenyl group, cyclodextrin, adamantane group, trityl group, fluorescein, silsesquioxane, and pyrene, and more preferably an adamantane group or cyclodextrin.

[0034] Examples of cyclic molecules constituting polyrotaxane include various cyclodextrins (α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and derivatives thereof, preferably derivatives that retain the carbon skeleton of cyclodextrin and have one or more functional groups bonded to the carbon skeleton substituted), crown ethers, benzocrowns, dibenzocrowns, dicyclohexanocrowns, and derivatives thereof. In terms of ease of grafting of polysiloxane chains, the cyclic molecule is preferably cyclodextrin. Furthermore, cyclodextrin may be a derivative in which one or more hydroxyl groups of cyclodextrin are substituted with other functional groups, and examples of cyclodextrin derivatives include, but are not limited to, methylated α-cyclodextrin, methylated β-cyclodextrin, methylated γ-cyclodextrin, hydroxypropylated α-cyclodextrin, hydroxypropylated β-cyclodextrin, and hydroxypropylated γ-cyclodextrin. Hydroxypropylated α-cyclodextrin, hydroxypropylated β-cyclodextrin and hydroxypropylated γ-cyclodextrin are preferred in terms of improving the mechanical strength of the composition containing them.

[0035] In the present disclosure, a polysiloxane chain is bonded to at least a part of a plurality of cyclic molecules of the polyrotaxane. Although the polysiloxane chain may be bonded to all the cyclic molecules in the polyrotaxane in the composition, it is sufficient that the polysiloxane chain is bonded to at least a part of the cyclic molecules in the polyrotaxane in the composition, as long as a silyl ether-silanol bond exchange reaction occurs between the silicone polymer material and the polysiloxane chain of the cyclic molecules of the polyrotaxane. By grafting a polysiloxane chain onto the cyclic molecules of polyrotaxane, the compatibility between the silicone polymer material and the polyrotaxane is improved compared to the case where the polysiloxane chain is not grafted onto the cyclic molecules of polyrotaxane.

[0036] For example, when the cyclic molecule is cyclodextrin, the cyclodextrin has a hydroxyl group in the molecule. Therefore, as shown in the synthesis scheme of FIG. 2, by reacting the cyclodextrin (shown as a ring) of polyrotaxane (PR) with a cyclic siloxane in a solvent in the presence of a bond exchange catalyst, the cyclic siloxane is opened, and a polysiloxane chain (polydimethylsiloxane chain in the figure) can be introduced into the cyclic molecule. The bond exchange catalyst includes, but is not limited to, basic catalysts such as 1,8-diazabicycloundecene-7 and 1,5-diazabicyclo-5. The solvent includes, but is not limited to, at least one organic solvent selected from the group consisting of DMSO, chloroform, DMF, DMAc, NMP, dichloromethane, THF, and toluene. The cyclic siloxane includes, but is not limited to, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and the like. The reaction temperature of the polyrotaxane and the cyclic siloxane is preferably 0 to 150° C., more preferably 40 to 100° C., but is not limited thereto. The reaction time of the polyrotaxane and the cyclic siloxane is preferably 30 minutes to 72 hours, more preferably 30 minutes to 1 day, but is not limited thereto. The siloxane chain bonded to the cyclic molecule has a hydroxy group at the end.

[0037] The cyclic molecule may further have additional functional groups other than the polysiloxane chain. Examples of the additional functional groups include hydroxyl groups, carboxyl groups, amino groups, epoxy groups, isocyanate groups, thiol groups, aldehyde groups, acetyl groups, propyl groups, hexanoyl groups, methyl groups, ethyl groups, propyl groups, 1-hydroxypropyl groups, poly-2-hydroxypropyl groups, polycaprolactone-modified hydroxypropyl groups, cyclohexyl groups, butylcarbamoyl groups, hexylcarbamoyl groups, phenyl groups, alkoxysilane groups, acryloyl groups, methacryloyl groups, cinnamoyl groups, polymers (polycarbonate groups, polyamide groups, polyurethane groups, etc.), or derivatives thereof.

[0038] A plurality of polyrotaxanes may be crosslinked to each other via the functional groups of the cyclic molecules. A plurality of polyrotaxanes may be directly bonded to each other via the functional groups of the cyclic molecules, or may be bonded to each other via a crosslinking agent reactive with the functional groups of the cyclic molecules. The composition of the present embodiment can be made tougher by converting the polyrotaxane into an elastomer through crosslinking.

[0039] In this specification, the inclusion rate refers to the ratio of the amount of cyclic molecules that include a linear polymer to the maximum amount of cyclic molecules that are included in the linear polymer. The inclusion rate can be determined, for example, by nuclear magnetic resonance spectroscopy (NMR) or gel permeation chromatography (GPC).

[0040] The inclusion rate of the polyrotaxane is preferably from 0.1 to 100%, more preferably from 0.1 to 50%, further preferably from 1 to 50%, and most preferably from 1 to 30%.

[0041] The amount of polyrotaxane in the composition of the present embodiment is not particularly limited, but from the viewpoint of improving the compatibility and toughness of the composition, the amount is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more.

[0042] In order to exert the inherent function of the polymer, the amount of polyrotaxane in the composition is preferably 50% by weight or less, more preferably 40% by weight or less, and even more preferably 30% by weight or less. In one embodiment, in order to improve the mechanical strength of the composition, the amount of polyrotaxane in the composition is 20% by weight or less.

[0043] In one embodiment, the amount of polyrotaxane in the composition is 0.1% by mass or more and 99.9% by mass or less. In another embodiment, the amount of polyrotaxane in the composition is 1 to 40% by mass, more preferably 1 to 30% by mass, and even more preferably 1 to 20% by mass.

[0044] In the composition, the mass ratio of the silicone polymer material (particularly the silicone elastomer) to the polyrotaxane (silicone polymer material:polyrotaxane) is preferably 99.0:0.1 to 1:1, more preferably 99:1 to 1:1, more preferably 95:5 to 1:1, more preferably 95:5 to 3:2, and even more preferably 95:5 to 4:1, from the viewpoint of improving the mechanical strength of the composition.

[0045] The total amount of the silicone-based polymer material and the polyrotaxane in the composition is not particularly limited, but from the viewpoint of improving the toughness of the composition, it is preferably 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more.

[0046] In some embodiments, the silicone-based polymeric material, silicone elastomer, or organosiloxane has -Si-OR 1 (R 1 R has Si or C, and a bond exchange reaction occurs between the silanol group or metal silanolate group of the polysiloxane chain bonded to the cyclic molecule of the polyrotaxane by heating. 1 A preferred example of is trialkylsilyl, and each alkyl in the trialkyl is preferably independently an alkyl having 1 to 6 carbon atoms. The polysiloxane chain preferably has a silanol group or a metal silanolate group at the end. The metal silanolate group is preferably an alkali metal silanolate group. For bond exchange between silyl ether (-Si-O-Si-) and silanol group (-Si-OH), see, for example, Tapas Debsharma et al., J.Am. Chem. Soc. 2022, 144, 12280-12289 DOI: 10.1021 / jacs.2c03518.

[0047] The composition of the present invention preferably contains a bond exchange catalyst. This is a catalyst that causes a bond exchange reaction between the silyl ether of the silicone-based polymer material and the silanol group or metal silanolate group of the polysiloxane chain grafted to the cyclic molecule of the polyrotaxane. The bond exchange catalyst is preferably a basic catalyst. Such basic catalysts are known and include, but are not limited to, the above-mentioned 1,8-diazabicycloundecene-7 and 1,5-diazabicyclo-5. The amount of the bond exchange catalyst or basic catalyst to be added can be appropriately determined by those skilled in the art. In some embodiments, the amount of the bond exchange catalyst or basic catalyst is 0.001 to 10 mass% relative to 100 parts by mass of the silicone-based polymer material.

[0048] The composition according to the embodiment of the present invention may contain, in addition to the silicone polymer material and the polyrotaxane, other additives such as a plasticizer, a surfactant, a lubricant, a filler, a dispersant, an antioxidant, a light stabilizer, an ultraviolet absorber, a colorant, a flame retardant, etc. These additives may be used alone or in combination of two or more kinds.

[0049] The composition of the present embodiment containing the silicone-based polymer material and polyrotaxane described above has improved toughness compared to a composition that differs only in that no polysiloxane chain is bonded to the polyrotaxane.

[0050] In some embodiments, the break stress of the composition, as measured in a uniaxial extension test, is increased over the break stress of a control that differs from the composition only in that no polysiloxane chains are attached to the polyrotaxane.

[0051] In some embodiments, the elongation at break of the composition, as measured in a uniaxial extension test, is increased relative to the elongation at break of a control that differs from the composition only in that no polysiloxane chains are attached to the polyrotaxane.

[0052] In some embodiments, the stress at break of the composition after heating for 12 hours or more at 50° C., as measured in a uniaxial extension test, is increased by at least 2-fold over the stress at break of a control that differs only in that it is not heated. In some embodiments, the elongation at break of the composition after heating for 12 hours or more at 50° C. as measured in a uniaxial extension test is at least 1.5 times greater than the elongation at break of a control that differs only in that it has not been heated.

[0053] Next, a method for producing a composition containing a silicone-based polymer material according to an embodiment of the present invention and a plurality of polyrotaxanes will be described.

[0054] According to one aspect of the present invention, there is provided a method for producing a composition by simply mixing a silicone-based polymeric material with a plurality of polyrotaxanes, the method comprising the steps of: The method includes mixing a silicone-based polymer material with a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules. The silicone polymer material and the polyrotaxane in which a polysiloxane chain is bonded to at least some of a plurality of cyclic molecules are as described above. Mixing of the silicone polymer material and the multiple polyrotaxanes is preferably carried out at a temperature between 0 and 40°C, and more preferably between 15 and 40°C.

[0055] The above method may further include, before mixing the silicone-based polymer material with the plurality of polyrotaxanes, reacting a plurality of cyclic molecules of each polyrotaxane with cyclic dimethylsiloxane to form a plurality of polyrotaxanes in which polysiloxane chains are bonded to at least a portion of the plurality of cyclic molecules.

[0056] The silicone-based polymeric material and the plurality of polyrotaxanes are preferably mixed in the presence of a bond exchange catalyst. The method may further include heating the composition including the silicone-based polymeric material, the plurality of polyrotaxanes, and the bond exchange catalyst to promote bond exchange between the silicone-based polymeric material, the silyl ether, and the silanol group or the metal silanolate group of the polyrotaxane.

[0057] Alternatively, the method may further include contacting a bond exchange catalyst with a composition comprising the silicone-based polymer material and the plurality of polyrotaxanes after mixing the silicone-based polymer material and the plurality of polyrotaxanes. By contacting the composition comprising the silicone-based polymer material and the plurality of polyrotaxanes with the bond exchange catalyst, the bond exchange catalyst is transferred into the composition.

[0058] The method may further include, after the contacting, heating the composition comprising the silicone-based polymeric material, the plurality of polyrotaxanes, and the bond exchange catalyst to promote bond exchange between the silicone-based polymeric material, the silyl ether, and the silanol groups or metal silanolate groups of the polyrotaxane.

[0059] In the composition of the above embodiment of the present invention, the bond exchange reaction is promoted by heating, and the transparency is increased. When the thermosetting composition is heated, the compatibility of the polysiloxane graft polyrotaxane with the silicone-based polymer material is increased, and the composition becomes transparent. The heating temperature is not particularly limited, but is preferably a temperature lower than the melting point of the silicone-based polymer material, and in one embodiment, is 30 to 240°C. In one embodiment, it is 30 to 200°C. In one embodiment, it is 50 to 180°C. The reaction time is preferably 30 minutes to 72 hours, more preferably 30 minutes to 1 day, but is not limited thereto.

[0060] According to another aspect of the present invention, instead, there is provided a method for producing a composition comprising a silicone-based polymer material and a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer penetrating the openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules, the silicone-based polymer material comprising a silicone elastomer that is a crosslinked product of a base agent and a crosslinking agent. The method includes mixing the base agent, the crosslinking agent, and the plurality of polyrotaxanes in the presence of a crosslinking catalyst, and crosslinking the base agent and the crosslinking agent.

[0061] Combinations of the base compound (1) and the crosslinking agent (2) include the following, where one compound can be either the base compound (1) or the crosslinking agent (2), and the other compound can be the other of the base compound (1) and the crosslinking agent (2): Compounds containing a methoxysilyl group (≡SiOCH3) and compounds containing a hydroxysilyl group (≡SiOH) Compounds containing hydrosilyl groups (≡SiH) and compounds containing hydroxysilyl groups (≡SiOH) Compounds containing a mercaptopropylsilyl group (≡Si-C3H6SH) and compounds containing a vinylsilyl group (≡SiCH=CH2) Compounds containing a vinylsilyl group (≡SiCH=CH2) and compounds containing a hydrosilyl group (≡SiH)

[0062] Crosslinking catalysts include platinum catalysts such as platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex.

[0063] The method may further include reacting the cyclic molecules of each polyrotaxane with cyclic dimethylsiloxane prior to crosslinking to form a plurality of polyrotaxanes having polysiloxane chains attached to at least a portion of the cyclic molecules.

[0064] The method may further include contacting the composition containing the silicone-based polymer material and the plurality of polyrotaxanes with a bond exchange catalyst after the crosslinking. By allowing the bond exchange catalyst to act at a different time from the crosslinking catalyst, it is possible to prevent interference between the catalysts. The method may further include, after the contacting, heating the composition comprising the silicone-based polymeric material and the plurality of polyrotaxanes to promote bond exchange between the silicone-based polymeric material, the silyl ether, and the silanol groups or metal silanolate groups of the polyrotaxane, preferably in the presence of a bond exchange catalyst.

[0065] In the composition of the above embodiment of the present invention, the bond exchange reaction is promoted by heating, and the transparency is increased. When the thermosetting composition is heated, the compatibility of the polysiloxane graft polyrotaxane with the silicone-based polymer material is increased, and the composition becomes transparent. The heating temperature is not particularly limited, but is preferably a temperature lower than the melting point of the silicone-based polymer material, and in one embodiment, is 30 to 240°C. In one embodiment, it is 30 to 200°C. In one embodiment, it is 50 to 180°C. The reaction time is preferably 30 minutes to 72 hours, more preferably 30 minutes to 1 day, but is not limited thereto.

[0066] As described above, the simple synthesis method of polysiloxane graft polyrotaxane can realize good mixing of the silicone polymer material and the polyrotaxane. Furthermore, the formation of chemical bonds between the silicone polymer material and the polysiloxane graft polyrotaxane in the obtained composition suppresses phase separation of the polyrotaxane, enabling more uniform dispersion than physical mixing.

[0067] The obtained composition according to the embodiment of the present invention can be molded into any three-dimensional shape, such as a film, sheet, cylinder, or case, by a known molding technique such as extrusion molding, press molding, vacuum molding, injection molding, blow molding, inflation molding, or foam molding, to form a molded article.

[0068] The composition according to the embodiment of the present invention and the molded article containing the same have toughness, and therefore can be used for various applications such as films, sheets, and household goods. As used herein, the term "film" refers to a thin film having a thickness of less than 250 μm. The term "sheet" refers to a plate-like member having a thickness of 250 μm or more.

[0069] Furthermore, when the composition according to the embodiment of the present invention is a thermosetting composition containing a silicone elastomer, such a composition and a molded article containing the same have toughness, and therefore can be suitably used in devices for which it is desired that maintenance is unnecessary or can be omitted, such as automobiles, ships, spacecraft, airplanes, windmills, sporting goods, building materials, defense products, electronic products, packaging materials, etc. The thermosetting composition according to the embodiment of the present invention can also be used in composite materials constituting such devices.

[0070] The disclosures of all patent applications and publications cited herein are hereby incorporated by reference in their entireties.

[0071] The following examples are intended for illustrative purposes only and are not intended to limit the scope of the present invention in any way. Unless otherwise specified, reagents are commercially available or are obtained or prepared according to conventional techniques or procedures known in the art. EXAMPLES

[0072] Example 1 Grafting of polydimethylsiloxane (PDMS) onto polyrotaxane (PR) In a nitrogen-purged two-necked flask, 1.0 g of PR35 (PEG axial molecular weight 35,000, CD inclusion rate 28%) was added. 8.4 mL of ultra-dehydrated dimethyl sulfoxide (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was added, and the temperature was raised to 50 ° C in an oil bath to dissolve PR35 (a compound in which some of the OH groups of α-CD of polyrotaxane consisting of linear molecule: PEG (weight average molecular weight 35000), cyclic molecule: α-cyclodextrin, and blocking group: adamantane amine group were hydroxypropylated). Next, 1.0 mL of diazabicycloundecene (DBU, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was stirred at 50 ° C for 30 minutes. Meanwhile, 24.4 g of hexamethylcyclotrisiloxane (manufactured by Tokyo Chemical Industry Co., Ltd.) was dissolved in 25.8 mL of ultra-dehydrated chloroform (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.), and the resulting chloroform solution was added to the reaction solution in 10 mL portions over 20 minutes. After the addition, the mixture was stirred at 50 ° C for 5 hours under a nitrogen atmosphere.

[0073] After the reaction, the chloroform was mainly removed by rotary evaporator, and after removal, 300 mL of methanol was added, causing the solid matter to precipitate, so the precipitate was allowed to settle, the supernatant was removed by decantation, and the precipitate was collected. The precipitate was washed with 300 mL of methanol, and the collected precipitate was dried under reduced pressure at room temperature to obtain 12.0 g of a grafted body (PDMS-PR-1) in which PDMS was grafted to translucent PR35.

[0074] The obtained PDMS-PR-1 was dissolved in chloroform and subjected to GPC measurement. The GPC chart with RI detection is shown in Figure 3. The peak showed an almost unimodal shape. The peak intensity showed a negative value because the refractive index of the chloroform solution of PDMS-PR-1 was smaller than the refractive index of chloroform (1.44). In addition, PDMS-PR-1 was dissolved in deuterated chloroform and 1 H-NMR measurements were carried out. 1The H-NMR chart is shown in Figure 2. A proton peak derived from the methyl group of PDMS was observed around 0 ppm. A part of the CD of PR35 is modified with a hydroxypropyl group, and a proton peak derived from the CD was observed at 4.8-5.1 ppm, a proton peak derived from the hydroxypropyl group and PEG was observed at 3.2-3.8 ppm, and a proton peak derived from the methyl group of the hydroxypropyl group was observed at 1.0-1.2 ppm. 1 The H-NMR results confirmed that PDMS was grafted onto PR35.

[0075] The amount of PDMS introduced is 1 The analysis was performed using H-NMR. As shown in Figure 4, when the integral value of the proton peak derived from CD at 4.8-5.1 ppm was set to 6.00 (considered as 1 equivalent of CD), the integral value of the proton peak derived from the methyl group of PDMS near 0 ppm was 2280. In other words, it was analyzed that 2280÷6=380 equivalents of dimethylsiloxane units of PDMS were introduced per equivalent of CD.

[0076] Example 2 Solubility of PDMS-PR-1 in solvents, compatibility with PDMS base material and crosslinking agent A solubility test of PDMS-PR-1 synthesized in Example 1 with a solvent was carried out. 10 mg of a sample was mixed with 1 mL of a solvent, and the solubility of the sample after standing for 1 hour and the turbidity of the solution were used to confirm the solvent solubility. PDMS-PR-1 was well soluble in chloroform and dichloromethane, soluble in THF and acetone but the solution became cloudy, and insoluble in dimethyl sulfoxide, dimethylformamide, methanol, and water. In contrast to the high solubility of PR35 used as the raw material, it showed low solubility in water, leaning towards the solubility of the PDMS graft group. A compatibility test of PDMS-PR-1 with each of the PDMS base material and crosslinking agent was carried out using the PDMS elastomer raw materials poly(dimethylsiloxane-co-methylhydrosiloxane) trimethylsilyl end (PDMS base material, Mw: ~13,000 g / mol, Sigma-Aldrich) and poly(dimethylsiloxane) vinyl end (PDMS crosslinking agent, Mw: ~25,000 g / mol, Sigma-Aldrich). PDMS-PR-1 was highly compatible with the PDMS base material, and the mixed solution became colorless and transparent, but it was soluble in the PDMS crosslinking agent, but the solution became cloudy.

[0077] Example 3 Preparation of PDMS elastomer containing PDMS-PR-1 0.1 g of the PDMS base material used in Example 2, 0.1 g of the crosslinking agent, and 0.01 g of PDMS-PR-1 were thoroughly dissolved in 2 mL of chloroform, and then 2 μL of platinum (0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex solution (manufactured by Sigma-Aldrich) was dropped as a crosslinking catalyst, and the solution was cast into a PFA petri dish after quick stirring. The sheet was left at room temperature for 12 hours or more and crosslinked, and then peeled off from the petri dish. For additional crosslinking and solvent removal, the sheet was dried under reduced pressure at 50°C for 12 hours or more to prepare a PDMS elastomer sheet containing PDMS-PR-1 (PDMS / PR elastomer). A PDMS elastomer sheet (PDMS elastomer) not containing PDMS-PR-1 was also prepared as a comparative material using the same procedure.

[0078] Example 4 Preparation of PDMS elastomer with silyl ether bond exchange catalyst The PDMS / PR elastomer sheet prepared in Example 3 was immersed in 10 mL of a chloroform solution mixed with 2 μL of DBU (manufactured by Tokyo Chemical Industry Co., Ltd.) as a silyl ether bond exchange catalyst, and left to stand at room temperature for 5 hours or more to volatilize the chloroform. The PDMS-PR-1-containing PDMS elastomer sheet into which DBU had penetrated was dried under reduced pressure at 50° C. for 12 hours or more to remove the remaining solvent and promote the bond exchange reaction. This sample was named BE-PDMS / PR elastomer 50. A sample prepared in the same manner using a PDMS elastomer sheet not containing PDMS-PR-1 was named BE-PDMS elastomer 50. In order to further activate the bond exchange reaction, the PDMS-PR-1-containing PDMS elastomer sheet was dried under reduced pressure at 50° C. for 12 hours or more, and then heated at 150° C. for 2 hours to give a sample named BE-PDMS / PR elastomer 150.

[0079] Example 5 Compatibility and mechanical properties of various elastomers Figure 5 shows the appearance of PDMS elastomer without PR (upper left), BE-PDMS elastomer 50 (upper right), PDMS / PR elastomer (lower left), and BE-PDMS / PR elastomer 50 (lower right). In the PDMS elastomer without PR, there was no change in appearance with or without the bond exchange catalyst, and all were colorless and transparent. On the other hand, in the PDMS / PR elastomer with PR added, a clear cloudiness was observed without the addition of the bond exchange catalyst, suggesting the formation of a domain of PR. However, in the BE-PDMS / PR elastomer 50 and BE-PDMS / PR elastomer 150, which contained the bond exchange catalyst and were heated at 50°C and 150°C, the cloudiness was reduced and they showed high transparency (BE-PDMS / PR elastomer 150 is not shown). This is suggested to be because the PDMS graft group of PR and the PDMS network form chemical bonds through silyl ether bond exchange, and PR is chemically incorporated into the network.

[0080] Similar effects were also seen in the mechanical properties from the uniaxial extension test shown in Figure 6. In the PDMS elastomer without PR added, there was no significant change in the mechanical properties due to bond exchange. In the PDMS / PR elastomer in which PR was physically mixed, there was no change in Young's modulus, which indicates the hardness of the material, compared to the unadded elastomer, and the breaking elongation was approximately twice as high. Furthermore, in the case of BE-PDMS elastomer 50, the breaking elongation was approximately four times higher than the unadded elastomer. It is believed that the addition of PR improves toughness due to the stress dispersion effect of PR, and that a dramatic improvement in toughness was achieved by chemically combining it with PDMS through bond exchange.

[0081] On the other hand, in the case of BE-PDMS elastomer 150, the Young's modulus was reduced to about half compared to the case without PR, and the breaking elongation was also about the same. This suggests that there is a combination of bond exchangeability and PR morphology in the PDMS network to obtain optimal mechanical properties, and that active bond exchange at 150 °C upsets this balance.

Claims

1. A silicone polymer material; a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules; A composition comprising:

2. -Si-OR in the silicone polymer material 1 (R 1 2. The composition according to claim 1, wherein a bond exchange reaction occurs by heating between the cyclic molecule of the polyrotaxane and a silanol group or a metal silanolate group of the polysiloxane chain bonded to the cyclic molecule of the polyrotaxane.

3. 3. The composition of claim 1 or 2, further comprising a bond exchange catalyst.

4. The composition of claim 2 which is a transparent composition.

5. The composition according to claim 1 or 2, wherein the silicone-based polymeric material comprises a silicone elastomer.

6. The composition according to claim 1 or 2, wherein the silicone-based polymeric material comprises a poly(dimethylsiloxane) backbone.

7. The composition according to claim 1, wherein the content of the polyrotaxane in the composition is 0.1% by mass or more and 99.9% by mass or less.

8. 1. A method for producing a composition comprising a silicone-based polymer material and a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules, the method comprising the steps of: mixing the silicone-based polymeric material and the plurality of polyrotaxanes in the presence of a bond exchange catalyst.

9. A method for producing a composition comprising a silicone-based polymer material and a plurality of polyrotaxanes, each of which comprises a plurality of cyclic molecules and a chain polymer passing through openings of the plurality of cyclic molecules, and a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules, the silicone-based polymer material comprising a silicone elastomer which is a crosslinked product of a base material and a crosslinking agent, the method comprising: mixing the base agent, the crosslinking agent, and the plurality of polyrotaxanes in the presence of a crosslinking catalyst to crosslink the base agent and the crosslinking agent.

10. The method of claim 9, further comprising reacting a plurality of cyclic molecules of each of the polyrotaxanes with cyclic dimethylsiloxane prior to the crosslinking to form a plurality of polyrotaxanes in which a polysiloxane chain is bonded to at least a portion of the plurality of cyclic molecules.

11. The composition is further heated in the presence of a bond exchange catalyst to convert -Si-OR 1 (R 1 The method of claim 9, further comprising: causing a bond exchange reaction between a metal silanolate group or a silanol group of a polysiloxane chain in the polyrotaxane (wherein the metal silanolate group is Si or C) and the silanol group or the metal silanolate group of a polysiloxane chain in the polyrotaxane.

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