JP2020015653A - Method for synthesizing composite gel, and composite gel - Google Patents

Abstract

To provide a method for synthesizing a composite gel, capable of improving mechanical strength of the composite gel and capable of optimizing physical properties thereof, by synthesizing a polymer gel (the composite gel) formed by compositing a polymer with an inorganic filler that is dispersed easily in the polymer and has a small particle diameter; and to provide the composite gel.SOLUTION: A method for synthesizing a composite gel includes: a CMPS-synthesizing step of mixing a solvent with an amine compound, a surfactant, and a silicon compound to synthesize a colloidal MPS (CMPS) in which the silicon compound is charged in at least some of pores; and a composite gel-synthesizing step of mixing the CMPS prepared at predetermined density with the solvent, a polymerizable monomer, a crosslinking agent, and an initiator, expediting a polymerization reaction of the polymerizable monomer, and synthesizing a polymer gel synthesized in the polymerization reaction with the CMPS to obtain the composite gel.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for synthesizing a composite gel, and a composite gel. In particular, the present invention relates to a method for synthesizing a composite gel containing an inorganic filler and a polymer, and a composite gel.

  The polymer gel is a swollen body in which a linear polymer is cross-linked to form a three-dimensional network structure and absorbs a large amount of a solvent. Since the distribution of cross-linking points in the polymer gel is biased, the structure is non-uniform, and there are non-uniform portions where a load is likely to be applied to the polymer chain and portions where the polymer chain is not easily applied. Therefore, the mechanical strength of the polymer gel is usually low. Therefore, the physical properties of polymer gels such as a composite gel in which an inorganic filler such as a clay mineral or carbon black is compounded with a polymer gel, or a topological gel in which a polyrotaxane containing a cyclic molecule is used as a movable crosslinking point for the polymer gel, etc. Research on improvement has been made.

  For example, mesoporous silica (MPS) used as a kind of inorganic filler is a porous material having highly uniform mesopores of 2 to 50 nm, and has a large specific surface area. Therefore, it is conceivable that MPS is used as a filler for a composite gel, and it has been reported that the mechanical strength is greatly improved by combining MPS and poly (N-isopropylacrylamide) (PNIPA) gel ( For example, see Non-Patent Document 1.)

Miyamoto, N .; et al. Chem. Eur. J. , 2014, 20, 14955

  However, MPS synthesized by a general method, such as that used in Non-Patent Document 1, has no control over the particle size, particle size distribution, and shape, and has a large particle size, and strongly aggregates during the synthesis process. It has the property of being difficult to disperse in polymer gels. Therefore, MPS tends to be unevenly distributed in the polymer gel. Therefore, it is difficult to optimize various physical properties such as mechanical properties of a polymer gel obtained by combining MPS and a polymer, that is, to control various physical properties.

  Accordingly, an object of the present invention is to synthesize a polymer gel (composite gel) in which a polymer and an inorganic filler having a small particle size that are easily dispersed in the polymer are synthesized, and to improve the mechanical strength of the composite gel. Another object of the present invention is to provide a method for synthesizing a composite gel which can optimize the properties and physical properties, and a composite gel.

  In order to achieve the above object, the present invention provides a CMPS in which a solvent is mixed with an amine compound, a surfactant and a silicon compound to synthesize a colloidal MPS (CMPS) in which at least a part of the pores is filled with the silicon compound. A synthesis step, a CMPS prepared at a predetermined concentration, a solvent, a polymerizable monomer, a cross-linking agent, and an initiator are mixed, a polymerization reaction of the polymerizable monomer is advanced, and a polymer gel synthesized by the polymerization reaction and the CMPS are mixed. A composite gel synthesizing step of synthesizing a composite gel.

  In the method for synthesizing the composite gel, it is preferable that the composite gel synthesizing step sucks at least a part of the polymerizable monomer into the pores of the CMPS.

  In the method for synthesizing a composite gel, the CMPS synthesis step preferably includes a dialysis step of dialyzing the CMPS.

  In the method for synthesizing the composite gel, it is preferable that the composite gel synthesizing step uses CMPS having a concentration of 0.00001 wt% or more and 10 wt% or less.

  In the method for synthesizing the composite gel, it is preferable that the CMPS has an average particle diameter of 10 nm or more and 500 nm or less, and a standard deviation in the particle diameter distribution is within 50% of the average particle diameter.

  In order to achieve the above object, the present invention provides a colloidal MPS (CMPS) having an average particle size of 10 nm or more and 500 nm or less and a standard deviation in the particle size distribution of 50% or less of the average particle size. Contains a polymer gel that is a swelling body in which a polymer having a three-dimensional network structure has absorbed a solvent, and the CMPS interacts with the polymer, and the CMPS is substantially uniformly dispersed in the polymer gel. This provides a composite gel that is composited with the polymer gel.

  In the composite gel, the polymer may be poly (N-isopropylacrylamide), and the solvent may be water.

  According to the method for synthesizing a composite gel and the composite gel according to the present invention, a polymer gel (composite gel) in which a polymer and an inorganic filler that is easily dispersed in the polymer and have a small particle size are synthesized. Thus, it is possible to provide a method for synthesizing a composite gel capable of improving the mechanical strength of the composite gel and optimizing the physical properties, and a composite gel.

It is a SEM image of CMPS concerning an example. It is a TEM image of the CMPS according to the example. It is a figure which shows the result of the tensile test of the composite gel which concerns on an Example, and the gel which concerns on a comparative example.

[Embodiment]
<Outline of method for synthesizing composite gel>
The composite gel according to the embodiment of the present invention is a composite of colloidal mesoporous silica (CMPS) and a polymer gel. This composite gel can be synthesized as follows. First, a predetermined amine compound, a surfactant, and a silicon compound are mixed in a predetermined solvent to synthesize a monodisperse CMPS having a small particle diameter. Then, the concentration of the synthesized CMPS is adjusted to a predetermined concentration. Subsequently, the CMPS adjusted to a predetermined concentration, a predetermined polymerizable monomer, a crosslinking agent, and an initiator are mixed in a predetermined solvent, and a polymerization reaction of the polymerizable monomer is allowed to proceed. As a result, a polymer gel is synthesized. Then, since the CMPS and the polymer gel coexist in the solvent, the CMPS and the polymer gel are combined with the synthesis of the polymer gel. Thereby, the composite gel according to the present embodiment is synthesized.

  In the present embodiment, the monodispersed CMPS having a small particle size exhibits high dispersibility in a solvent and exists without aggregation. When the monomer constituting the polymer is added, a part of the monomer is sucked into the mesopores of the CMPS, and the amount of the monomer in the solution decreases. When the polymerization reaction proceeds in this state, CMPS while maintaining high dispersibility is included in the polymer gel.

  Here, it is assumed that the polymer and the CMPS have a predetermined interaction. The details of this interaction are not clear at this stage, but the fact that CMPS exists as a topological cross-linking point of the polymer, that the CMPS physically cross-links the polymers, and / or that the polymer chains penetrate the pores of the CMPS. It is presumed that an interaction such as the action has occurred.

  As a result, a state in which the CMPS is substantially uniformly dispersed in the composite gel is maintained, and a part of the monomer is sucked into the pores (mesopores) of the CMPS, so that the amount of the polymer is reduced from the added monomer. Since the amount is smaller than the calculated amount of the polymer, it is presumed that a composite gel having significantly improved mechanical strength can be synthesized while maintaining a soft state.

  Hereinafter, the composite gel according to the present embodiment and the method for producing the same will be described in detail.

<Details of composite gel and its manufacturing method>
The composite gel according to the present embodiment includes a CMPS synthesis step of synthesizing roughly colloidal mesoporous silica (CMPS), and a composite gel of a polymer gel and CMPS synthesized by polymerizing a predetermined monomer mixed with CMPS. And synthesizing a composite gel. The CMPS synthesis step can also include a dialysis step for dialyzing the CMPS.

[Colloidal mesoporous silica (CMPS) synthesis process]
The CMPS synthesis step is a step of mixing an amine compound, a surfactant, and a silicon compound in a solvent to synthesize colloidal MPS (CMPS) in which at least a part of the pores is filled with the silicon compound. The CMPS synthesis step preferably includes a dialysis step of mixing various materials with a solvent and then dialyzing the CMPS using a predetermined solvent or solution.

  Specifically, the CMPS synthesis step is a first step in which a predetermined amount of an amine compound and a surfactant are added to a predetermined solvent, and the mixture is stirred at a predetermined temperature for a predetermined time, and a predetermined amount of a silicon compound is added thereto. , And a dialysis step. The dialysis step after the second step can be performed, for example, by putting the solution obtained in the second step into a container or the like constituted by using a semipermeable membrane and putting the container into a predetermined solvent or solution. The dialysis is preferably performed a plurality of times by replacing a predetermined solvent or solution. After the dialysis step, the CMPS according to the present embodiment is obtained.

(solvent)
As the solvent, an aqueous solvent, for example, pure water can be used. Alternatively, a mixed solution of pure water and an alcohol (methanol, ethanol, propanol, or the like) can be used as the solvent.

(Amine compound)
Examples of the amine compound include amine compounds having a primary amino group, a secondary amino group, or a tertiary amino group. In the CMPS synthesis step, it is preferable to add 0.1 to 10 parts by weight of an amine compound to 100 parts by weight of a solvent, and to add 0.1 to 1 part by weight of an amine compound. Is more preferred.

  Examples of the amine compound having a primary amino group include primary alkanolamines such as monoethanolamine, diglycolamine, 2-amino-2-methyl-1-propanol and 2-amino-1-propanol, propylamine, Aliphatic amines such as isopropylamine, butylamine, amylamine, hexylamine, octylamine, decylamine, undecylamine and dodecylamine; aromatic amines such as benzylamine, aniline, o-toluidine, m-toluidine, p-toluidine; Alicyclic amines such as butylamine, cyclopentylamine and cyclohexylamine can be mentioned.

  Examples of the amine compound having a secondary amino group include 2-methylaminoethanol, 2-ethylaminoethanol, Nn-propylaminoethanol, 2-isopropylaminoethanol, Nn-butylaminoethanol, and N-isobutyl. Aminoethanol, 3-ethylamino-1-propanol, 3-n-propylamino-1-propanol, 3-isopropylamino-1-propanol, 3-n-butylamino-1-propanol, 3-isobutylamino-1- Secondary alkanolamines such as propanol, diethanolamine and diisopropanolamine, dimethylamine, diethylamine, dipropylamine, di-n-butylamine, di-sec-butylamine, dipentylamine, dihexylamine, di-n-octylamine , Di- (2-ethylhexyl) amine, dicyclohexylamine, N-methylbenzylamine, diallylamine, morpholine, piperazine, 2,6-dimethylmorpholine, 2,6-dimethylpiperazine, 2-methylpiperazine, piperidine, 3,3- Dimethylpiperidine, 2,6-dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, pyrrolidine, 2,5-dimethylpyrrolidine, azetidine, hexamethyleneimine, heptamethyleneimine, 5-benzyloxyindole, 3-azaspiro [5,5] undecane, 3-azabicyclo [3.2.2] nonane, carbazole and the like.

  Examples of the amine compound having a tertiary amino group include tertiary alkanolamines such as N-methyldiethanolamine and triethanolamine (TEA), N, N, N ′, N′-tetramethyl-1,6-diaminohexane. Tertiary alkylamines such as N, N, N ', N'-tetramethyl-1,3-diaminobutane, bis (2-dimethylaminoethyl) ether, N, N-dimethyl-o-toluidine, N-dimethyl-p-toluidine, N, N-dimethyl-m-toluidine, α-picoline, β-picoline, γ-picoline, benzyldimethylamine, benzyldiethylamine, benzyldipropylamine, benzyldibutylamine, (o-methyl (Benzyl) dimethylamine, (m-methylbenzyl) dimethylamine, (p-methylbenzyl) dimethyl Amine, N, N-tetramethylene-o-toluidine, N, N-heptamethylene-o-toluidine, N, N-hexamethylene-o-toluidine, N, N-trimethylenebenzylamine, N, N-tetramethylene Benzylamine, N, N-hexamethylenebenzylamine, N, N-tetramethylene (o-methylbenzyl) amine, N, N-tetramethylene (p-methylbenzyl) amine, N, N-hexamethylene (o-methyl) Benzyl) amine, N, N-hexamethylene (p-methylbenzyl) amine and the like.

(Surfactant)
As the surfactant, a cationic surfactant or a nonionic surfactant can be used. In the present embodiment, it is preferable to use a cationic surfactant from the viewpoint of performing wet synthesis under basic conditions in order to use monodispersed fine particles having a small particle size so as not to precipitate during synthesis of the composite gel.

  Examples of the cationic surfactant include alkyltrimethylammonium halide, alkyltriethylammonium halide, dialkyldimethylammonium halide, alkylmethylammonium halide, and alkoxytrimethylammonium halide. Examples of the alkyltrimethylammonium halide include lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, stearyltrimethylammonium chloride, benzyltrimethylammonium chloride, and behenyltrimethylammonium chloride. Examples of the alkyltrimethylammonium halide include n-hexadecyltrimethylammonium chloride. Examples of the dialkyldimethylammonium halide include distearyldimethylammonium chloride and stearyldimethylbenzylammonium chloride. Examples of the alkylmethylammonium halide include cetylmethylammonium chloride, stearylmethylammonium chloride, and benzylmethylammonium chloride. Examples of the halogenated alkoxytrimethylammonium include octadecyloxypropyltrimethylammonium chloride. In the quaternary ammonium salt, the halogen may be bromine. In this case, cetyltrimethylammonium bromide, tetrabutylammonium bromide, tetrahexylammonium bromide, tetraheptylammonium bromide, decyltrimethylammonium bromide, tetra-n-octylammonium bromide, tetrapropylammonium bromide, Tetraoctyl ammonium, tetradecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium bromide, octadecyl trimethyl ammonium bromide, dodecyl trimethyl ammonium bromide, decyl trimethyl ammonium bromide, octyl trimethyl ammonium bromide, hexyl trimethyl ammonium bromide and the like. Can be

  Examples of the nonionic surfactant include block copolymers of ethylene oxide and propylene oxide, and polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, and polyoxyethylene stearyl ether.

  In the CMPS synthesis step, it is preferable to add 0.1 to 10 parts by weight of a surfactant to 100 parts by weight of a solvent, and 0.5 to 2 parts by weight of a surfactant. Is more preferable.

(Silicon compound)
Examples of the silicon compound include tetraalkyl orthosilicate such as tetramethyl orthosilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, and tetrabutyl orthosilicate. Furthermore, a silicate (sodium silicate) is also included.

  In the CMPS synthesis step, it is preferable to add 0.1 to 10 parts by weight of a silicon compound to 100 parts by weight of a solvent, and 0.5 to 2 parts by weight of a silicon compound. Is more preferred.

(Dialysis process)
In the dialysis step, the solution obtained in the second step (the solution after adding the silicon compound and stirring for a predetermined time) is placed in a predetermined container, and the container is placed in a predetermined solvent or solution at a predetermined temperature for a predetermined time, Can be implemented. The container is formed using, for example, a semi-permeable membrane (for example, a semi-permeable membrane such as a dialysis cellulose tube sold by Nippon Medical Science). The predetermined solvent or solution may be a liquid having a concentration different from that of the solution obtained in the second step. For example, pure water, a mixed solution of an acid and an alcohol having a predetermined concentration (for example, acetic acid and ethanol, And the like can be used. Through the dialysis step, unreacted surfactant is removed, and a CMPS having a small average particle size and a narrow particle size distribution can be obtained.

  Here, the CMPS of the present embodiment preferably has an average particle size of 10 nm or more and 100 nm or less, and more preferably 19 nm or more and 25 nm or less. Further, it is preferable that the standard deviation in the particle size distribution (for example, number conversion distribution) of CMPS be within 25% of the average particle size value. The average particle size and the standard deviation of the CMPS can be obtained by using a dynamic light scattering method (DLS). The particle size and shape of the CMPS can also be measured and confirmed using a transmission electron microscope (TEM) and / or a scanning electron microscope (SEM).

[Composite gel synthesis process]
In the composite gel synthesis step, the solvent is mixed with CMPS prepared at a predetermined concentration, a polymerizable monomer, a cross-linking agent, and an initiator, the polymerization reaction of the polymerizable monomer proceeds, and a polymer gel synthesized by the polymerization reaction is mixed with the polymer gel. This is a step of synthesizing a composite gel with CMPS.

  For example, the composite gel synthesis step includes a raw material addition step of adding a polymerizable monomer, a cross-linking agent, and an initiator and a CMPS prepared to a predetermined concentration to a solvent in a predetermined container, and an inert gas atmosphere in a solution in the predetermined container. And a bubbling step of allowing the reaction to proceed while feeding. The solution in the predetermined container is preferably stirred during the bubbling step. After the bubbling process, the composite gel according to the present embodiment (i.e., the CMPS-polymer composite gel) is synthesized by irradiating the content in the container with light having a predetermined wavelength for a predetermined time. As a result, a polymer gel in which a polymer having a three-dimensional network structure is swollen by absorbing a solvent is synthesized, and CMPS and the polymer interact with each other, so that CMPS is substantially contained in the polymer gel. A composite gel that is uniformly dispersed in the polymer gel and composited with the polymer gel can be synthesized.

  The polymerization reaction to be used is not particularly limited, and examples include a radical polymerization method using a photoradical initiator.

(Concentration of CMPS)
The concentration of CMPS is preferably 0.00001 wt% or more and 10 wt% or less based on the total amount of the polymer gel and CMPS, and it is more preferable to use CMPS having a concentration of 0.0002 wt% or more and 0.04 wt% or less. In the composite gel according to the present embodiment, the intended effect is exhibited even if the amount of CMPS is very small relative to the entire composite gel (that is, the total amount of the polymer gel and CMPS).

(Polymerizable monomer)
Examples of the polymerizable monomer include, but are not particularly limited to, a monomer having an amide group, a monomer having a hydroxyl group, and a monomer having a carboxyl group. For example, a (meth) acrylamide derivative, a (meth) acrylate containing a hydroxy group, an amino group, or the like, and other monomers can be used. Here, (meth) acryl indicates methacryl or acryl. Further, (meth) acrylate indicates methacrylate or acrylate.

((Meth) acrylamide derivative)
Examples of the (meth) acrylamide derivative include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl (meth) acrylamide, N, N-dibutyl (Meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, N, N-diethylaminopropyl (meth) acrylamide, N, N-dipropylaminopropyl (meth) acrylamide, N-methyl (meth) acrylamide, N -Ethyl (meth) acrylamide, N-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-methylol (meth) acrylamide, acryloyl morpholine, methacryloyl morpholine, and the like.

((Meth) acrylate containing hydroxy group or amino group)
Examples of the (meth) acrylate include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, and N, N-dimethylaminoethyl (meth) acrylate. , N, N-diethylaminoethyl (meth) acrylate, N, N-dipropylaminoethyl (meth) acrylate, (meth) acryloylmorpholine, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, or 3-hydroxypropyl (meth) acrylate and the like.

  Other polymerizable monomers include water-soluble monomers such as acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, N-vinylpyrrolidone, and vinyl acetate, and (meth) acrylates (2-hydroxymethyl) having a reactive functional group. (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, glycidyl (meth) acrylate, and the like. These polymerizable monomers may be used alone or in combination of two or more.

(Crosslinking agent)
As the cross-linking agent, various compounds can be used as long as they have two or more cross-linkable functional groups and / or one or more polar groups in the molecule.

  Examples of the crosslinking agent include diallylamine, N, N '-(1,2-dihydroxyethylene) bisacrylamide, 2,4,8,10-tetraoxaspiro [5.5] undecane, and 3,9-divinyl-2. , 4,8,10-Tetraoxaspiro [5.5] undecane, triallylamine, bis (vinylsulfonyl) methane, 1,3-bis (vinylsulfonyl) -2-propanol, 1,3-divinyl-1,1 , 3,3-tetramethyldisilazane, 1,3-divinyltetramethyldisiloxane, 1,6-bis (acryloyloxy) hexane, N, N'-bis (acryloyl) cystamine, bis (vinylsulfonyl) methane, , 3-Bis (vinylsulfonyl) -2-propanol, N, N'-bis (vinylsulfonylacetyl) ethylenediamine Diallyl adipate, 10-vinyl undecenoate, trans, cis-2,6-nonadienal, divinyl adipate, cis-3-hexenyl cis-3-hexenoate, 2-isopropenyl-5-methyl-5-vinyltetrahydrofuran, (2,7-octadien-1-yl) succinic anhydride, diallyl 1,4-cyclohexanedicarboxylate (cis-, trans-mixture); divinyl glycol, divinyl sulfone, divinyl adipate, divinyl sebacate, diethylene glycol divinyl ether , Triethylene glycol divinyl ether, diethylene glycol diacrylate, ethylene glycol diacrylate, 1,4-phenylene bisacrylate, polyethylene glycol diacrylate, N, N'-diacryloylethyl Njiamin, N, N'-hexamethylene bisacrylamide, N, N'-methylene bis-acrylamide; diacrylate 1,4-butane diol. These crosslinking agents may be used alone or in combination of two or more.

  Examples of the crosslinkable functional group include a vinyl group and an acrylic group. Further, as the polar group, for example, amino group, imino group, nitrile group, ammonium group, imide group, amide group, hydrazo group, azo group, diazo group, sulfide group, disulfide group, sulfonyl group, sulfinyl group, thiocarbonyl Groups, hydroxyl group, carboxyl group, carbonyl group, epoxy group, oxycarbonyl group, nitrogen-containing heterocyclic group, oxygen-containing heterocyclic group, tin-containing group, alkoxysilyl group and the like.

  In this embodiment, the crosslinking agent is preferably added in an amount of 0.1 to 5 parts by weight, more preferably 0.2 to 1 part by weight, based on 100 parts by weight of the polymerizable monomer. preferable.

(Initiator)
As the initiator, a photoinitiator, a thermal initiator, a redox initiator, or the like can be used depending on the method of synthesizing the polymer constituting the polymer gel.

  As the photoinitiator, a photoradical generator, a photobase generator, a photoacid generator and the like can be used. The photo radical generator is a compound that generates a radical by irradiation with an active energy ray such as an ultraviolet ray or an electron beam.

  As the photoinitiator, for example, aromatic ketones including thioxanthone and the like, α-aminoalkylphenones, α-hydroxyketones, acylphosphine oxides, oxime esters, aromatic onium salts, organic peroxides, Examples include thio compounds, hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds. Among these, at least one selected from the group consisting of acylphosphine oxide-based polymerization initiators, α-aminoalkylphenone-based polymerization initiators, α-hydroxyketone-based polymerization initiators, and oxime ester-based polymerization initiators It is preferred to use an initiator.

  As acylphosphine oxide-based polymerization initiators, for example, bis (2,4,6-trimethylbenzoyl) -phenyl-phosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphenyl Phosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and the like. Examples of the α-aminoalkylphenone-based polymerization initiator include, for example, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one and 2-benzyl-2- (dimethylamino) -1 -(4-morpholinophenyl) -1-butanone, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like No.

  Examples of the α-hydroxyketone polymerization initiator include, for example, 2-hydroxy-1- {4- [4- (4-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methyl-propane -1-one, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4 ′-(2-hydroxyethoxy) -2-methylpropiophenone, 1-hydroxy-cyclohexyl-phenyl-ketone, oligo {2- Hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone} and the like.

  Examples of the oxime ester-based polymerization initiator include 1.2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], ethanone, 1- [9-ethyl-6- (2- Methylbenzoyl) -9H-carbazol-3-yl]-, 1- (o-acetyloxime), methanone, ethanone, 1- [9-ethyl-6- (1,3-dioxolane, 4- (2-methoxyphenoxy) ) -9H-carbazol-3-yl]-, 1- (o-acetyloxime) and the like.

  Examples of the thermal initiator include organic peroxides such as benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, 2,2′-azobisisobutyronitrile, and 2,2′-azobis-. And azo compounds such as (2-methylbutyronitrile) and 2,2′-azobis (2,4-dimethylvaleronitrile).

  Examples of the redox initiator include a combination of a persulfate initiator and a reducing agent (sodium metabisulfite, sodium bisulfite, a thiourea compound, etc.); a combination of an organic peroxide and a tertiary amine (for example, A combination of benzoyl peroxide and dimethylaniline, a combination of cumene hydroperoxide and anilines, etc.); a combination of an organic peroxide and a transition metal.

  In the present embodiment, the initiator is preferably added in an amount of 0.1 to 0.5 part by weight, preferably 0.2 to 1 part by weight, based on 100 parts by weight of the polymerizable monomer. Is more preferred.

  The composite gel according to this embodiment can be applied to various fields such as a material for a contact lens, a material for a disposable diaper, a material for an artificial muscle, and a material constituting a soft actuator. Further, the composite gel is expected to be applied as a material for components that require both flexibility and strength.

<Effects of Embodiment>
In the composite gel according to the present embodiment, since synthesis is performed through a step in which CMPS and a polymerizable monomer coexist, a part of the polymerizable monomer is sucked into the mesopores of the CMPS, so that the monomer in the solution is The amount can be reduced. Therefore, since the polymerization reaction can proceed in this state, the CMPS can be fixed in the polymer gel while maintaining the high dispersibility of the CMPS. Thereby, in the method for producing a composite gel according to the present embodiment, a composite gel in which CMPS is substantially uniformly dispersed in the composite gel can be synthesized, and the composite gel can be synthesized only by adding a small amount of CMPS. It can greatly improve the mechanical strength (fracture stress, fracture strain) of the gel and control various physical properties.

  Hereinafter, the composite gel according to the present embodiment and the method for producing the same will be specifically described using examples.

[Synthesis of CMPS]
A solution obtained by mixing 0.42 g of triethanolamine, 2.0 g of cetyltrimethylammonium bromide (CTABr), and 240 ml of pure water was stirred at 80 ° C. for 30 minutes. Subsequently, 2.44 ml of tetraethyl orthosilicate was added to this solution, followed by stirring at 80 ° C. for 2 hours. As a result, a CMPS solution in which pores were filled with CTABr was synthesized (hereinafter, referred to as a “CMPS solution before dialysis”). Subsequently, 50 ml of the CMPS solution was dialyzed for 5 days using 250 ml of a mixture of 2M acetic acid and ethanol. The mixing ratio of 2M acetic acid and ethanol is 1: 1 by volume. Furthermore, dialysis was performed for 2 days using 250 ml of pure water. Thereby, the CMPS according to the example was obtained.

[Synthesis of composite gel]
First, 2.0 g of N-isopropylacrylamide, 1.0 ml of a 0.01 g / ml N, N′-methylenebisacrylamide solution as a cross-linking agent, a predetermined amount of 0.19 wt% of CMPS, A solution was prepared by adding 10 μl of -hydroxy-2-methylpropiophenone and pure water to a total volume of 10 ml. Next, nitrogen was bubbled into the solution for 20 minutes (nitrogen bubbling). Subsequently, this solution was stirred under a nitrogen atmosphere for 24 hours, and then placed in a rectangular parallelepiped mold (size: 1 mm × 10 mm × 100 mm) having a capacity of 1 ml, and irradiated with ultraviolet light (light source: Toshiba FL10BLB, peak wavelength: 352 nm) for 15 hours. Minutes. Thus, a CMPS / poly N-isopropylacrylamide (PNIPA) composite gel was obtained.

  In addition, the addition amount of CMPS was 10 μl in Example 1: 100 μl in Example 2, 250 μl in Example 3: 2.0 ml in Example 4. As Comparative Example 1, a gel without the addition of CMPS (the amount of CMPS added: 0 ml) was also synthesized in the same manner as described above. That is, the CMPS concentration of the composite gel according to Example 1 was 0.0002 wt%, that of Example 2 was 0.002 wt%, that of Example 3 was 0.005 wt%, and that of Example 4 was 0.04 wt%. It is.

[Visual observation of CMPS]
The CMPS solution (CMPS dispersed in pure water) obtained by synthesis of CMPS was visually observed. As a result, the CMPS solution was colorless and transparent. Therefore, it was confirmed that the CMPS did not aggregate and was dispersed in the solvent with high dispersibility.

[CMPS particle size measurement (DLS)]
DLS measurement was performed on the CMPS obtained by synthesizing the CMPS (the measuring apparatus used was a dynamic light scattering photometer DLS8000 manufactured by Otsuka Electronics Co., Ltd. The measurement conditions were a He-Ne laser, the number of times of integration was 1,000 times, and the temperature was 25 ° C). As a result of the measurement, the obtained CMPS had an average particle size of 21.8 nm and a standard deviation of 5.3 nm. Therefore, it was confirmed that the particle size of CMPS was as small as about 20 nm and the particle size distribution was narrow.

[CMPS particle size measurement (SEM, TEM)]
FIG. 1 is an SEM image of the CMPS according to the example, and FIG. 2 is a TEM image of the CMPS according to the example.

  The SEM observation and the TEM observation were performed on the CMPS obtained by the synthesis of the CMPS. For SEM observation, SU9000 manufactured by Hitachi High-Technologies Corporation was used. For TEM observation, JEM-2010 manufactured by JEOL Ltd. was used.

  As shown in FIG. 1, in the SEM image (magnification: 400 times), it was confirmed that the obtained CMPS was spherical particles having irregularities and particles having a particle size of about 20 nm. Further, as shown in FIG. 2, it was confirmed in the TEM image (magnification: 1000 times) that the obtained CMPS had pores in the particles.

[FT-IR (change of CMPS synthesis before and after dialysis)]
In the synthesis of CMPS, FT-IR measurement was performed on each of the CMPS solution before dialysis and the CMPS solution obtained after dialysis. For the FT-IR measurement, a Fourier transform infrared spectrophotometer (FT-IR) Cary670 manufactured by Agilent Technologies, Inc. is used, and the measurement condition is the KBr method.

  As a result of the measurement, it was confirmed that the peak attributed to the methylene group confirmed in the CMPS solution before dialysis disappeared in the CMPS solution after dialysis. This confirmed that the surfactant was removed after dialysis.

[Tension test of composite gel]
FIG. 3 shows the results of a tensile test of the composite gel according to the example and the gel according to the comparative example. In FIG. 3, the horizontal axis shows the breaking strain (%), and the vertical axis shows the breaking stress (kPa).

  Tensile tests were performed on each of the composite gel according to Examples 1 to 4 and the gel according to Comparative Example 1. Specifically, a rectangular test piece of 1 mm × 10 mm × 100 mm was produced for each of the composite gels according to Examples 1 to 4 and the gel according to Comparative Example 1.

  The tensile test was performed using a single column type material tester STA-1150 manufactured by Orientec Co., Ltd. Fix both ends of the test piece of the composite gel according to Examples 1 to 4 or the test piece of the gel according to Comparative Example 1 with a jaw, and pull at 23 ± 2 ° C. relative humidity 50 ± 5% at a pulling speed of 5 mm / min. A test was performed to measure the breaking strain (%), the breaking stress (kPa), and the elastic modulus (kPa). In addition, the elastic modulus was measured by obtaining from the gradient of the initial value of the stress.

  As a result, as shown in FIG. 3, the test piece according to Comparative Example 1 to which CMPS was not added had a breaking stress of 11.4 kPa, a breaking strain of 56.7%, and an elastic modulus of 29.3 kPa. The breaking stress of the test piece according to Example 1 was 36.7 kPa, the breaking strain was 305%, and the elastic modulus was 20.6 kPa. That is, in the test piece according to Example 1, it was confirmed that the breaking stress was 3.2 times and the breaking strain was improved to 5.4 times as compared with Comparative Example 1.

  Further, in the test piece according to Example 2, the breaking stress was 23.5 kPa, the breaking strain was 224%, and the elastic modulus was 23.3 kPa. In the test piece according to Example 3, the breaking stress was 13.4 kPa, the breaking strain was 103%, and the elastic modulus was 21.5 kPa. Further, in the test piece according to Example 4, the breaking stress was 11.2 kPa, the breaking strain was 90%, and the elastic modulus was 21.0 kPa.

  From the above, in the composite gel according to the examples, it is shown that the average particle size is small, the particle size distribution contains CMPS, and the CMPS has high dispersibility without agglomeration. It was shown that the composite with the polymer can significantly improve the rupture stress and / or rupture strain without substantially changing the elastic modulus of the composite gel as compared with the case without CMPS. In particular, as shown in Example 1, when the concentration of CMPS was very small, it was shown that the breaking stress and the breaking strain were significantly increased.

  The embodiments and examples of the present invention have been described above, but the embodiments and examples described above do not limit the invention according to the claims. Also, it should be noted that not all combinations of the features described in the embodiments and examples are necessarily essential to the means for solving the problems of the invention.

Claims (7)

A CMPS synthesis step of mixing an amine compound, a surfactant, and a silicon compound in a solvent to synthesize a colloidal MPS (CMPS) in which at least a part of the pores is filled with the silicon compound;
The CMPS prepared at a predetermined concentration, a solvent, a polymerizable monomer, a cross-linking agent, and an initiator are mixed, and the polymerization reaction of the polymerizable monomer is advanced, and the polymer gel synthesized by the polymerization reaction and the CMPS are mixed. A composite gel synthesis step of synthesizing a composite gel.   The method for synthesizing a composite gel according to claim 1, wherein the composite gel synthesizing step causes at least a part of the polymerizable monomer to be sucked into pores of the CMPS. The method for synthesizing a composite gel according to claim 1 or 2, wherein the CMPS synthesis step includes a dialysis step of dialyzing the CMPS.   The method for synthesizing a composite gel according to any one of claims 1 to 3, wherein the composite gel synthesis step uses the CMPS at a concentration of 0.00001 wt% or more and 10 wt% or less.   The synthesis of the composite gel according to any one of claims 1 to 4, wherein the CMPS has an average particle size of 10 nm or more and 500 nm or less, and a standard deviation in the particle size distribution is 50% or less of the average particle size value. Method. A colloidal MPS (CMPS) having an average particle size of 10 nm or more and 500 nm or less and a standard deviation in the particle size distribution of 50% or less of the average particle size value;
A polymer gel having a swelling body in which a polymer having a three-dimensional network structure has absorbed a solvent,
A composite gel in which the CMPS interacts with the polymer, and the CMPS is substantially uniformly dispersed in the polymer gel to form a composite with the polymer gel. The polymer is poly (N-isopropylacrylamide),
The composite gel according to claim 6, wherein the solvent is water.

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