JP5393581B2 - Method for producing organic-inorganic composite dispersion - Google Patents

Description

  In the present invention, organic-inorganic composite particles (X) in which a polymer (P) of a (meth) acrylic monomer (A) and a water-swellable clay mineral (B) form a three-dimensional network include water The present invention relates to a method for producing an organic-inorganic composite dispersion characterized by being dispersed in a medium (C).

  Polymer composites called nanocomposites have been prepared by combining organic polymers such as polyamide, polystyrene, polypropylene, polyimide, and polyurethane with clay. Since the resulting polymer composite has finely dispersed clay layers with a large aspect ratio, it has been reported that the elastic modulus, heat distortion temperature, gas permeability, and burning rate are effectively improved. (For example, refer nonpatent literature 1).

  As the amount of clay mineral contained in the polymer composite, a high clay mineral content is desired from the viewpoint of performance enhancement, but it is also important to achieve effective performance enhancement with a lower amount of clay mineral. . In the studies so far, 0.2 to 5% by mass is usually used, and a low inorganic content polymer complex of 0.1% by mass or less and a high inorganic content polymer complex exceeding 10% by mass are not used. This is so small that the performance improvement effect is ignored when the inorganic content is low, while the increase in viscosity at the time of production is large when the inorganic content is high, at the nanoscale of the clay mineral in the resulting composite. This is because fine and uniform dispersion cannot be achieved, or the composite becomes brittle and mechanical properties (strength and elongation) are greatly reduced.

  To solve such problems, an organic-inorganic composite hydrogel in which clay mineral is uniformly dispersed in an organic polymer in a wide range of clay mineral content is disclosed as a nanocomposite material exhibiting excellent mechanical properties. Inorganic composite hydrogels form polymer composites with good mechanical properties by polymerizing acrylamide, methacrylamide derivatives, (meth) acrylates, etc. in the presence of water-swellable clay minerals and polymerization initiators in aqueous media. It is disclosed that it can be manufactured (for example, refer to Patent Document 1 and Patent Document 2).

  Moreover, as a nanocomposite material exhibiting excellent mechanical properties in a dry state, a polymer obtained from a water-soluble (meth) acrylic acid ester (a) and a water-swellable clay mineral (B) form a three-dimensional network. The polymer composite is characterized by comprising: a water-swellable clay mineral (B), a water-soluble (meth) acrylic acid ester (a), a polymerization initiator, and further if necessary The catalyst or / and the organic crosslinking agent (C) are dissolved or uniformly dispersed in water or a mixed solvent of water and an organic solvent, and then the polymer is polymerized and then dried to remove the solvent. Discloses that a polymer composite can be produced (see, for example, Patent Document 3).

  Furthermore, a method is disclosed in which an organic-inorganic composite hydrogel is hardly affected by oxygen and can be produced in a short time, that is, a reaction in which a water-insoluble polymerization initiator (d) is dispersed in an aqueous medium (c). A method of producing an organic-inorganic composite hydrogel having excellent mechanical properties by reacting a water-soluble acrylic monomer (A) by irradiation with energy rays in the presence of a water-swellable clay mineral (B) in a solution. (For example, see Patent Document 4).

  The organic-inorganic composite hydrogel and polymer composite shown above are all bulk bodies, and are manufactured through a process in which the entire reaction system is gelated even in the manufacturing process. Each of them also contains a polymerization initiator that generates radicals in the reaction solution, and depending on the intended purpose, a step of removing the initiator from the gel after preparation is required.

  In addition, after irradiating plasma on the film surface of an organic polymer such as polytetrafluoroethylene (PTFE) and reacting with moisture in the air, the PTFE film is placed in an aqueous solution of a water-soluble monomer such as acrylic acid. The technology to graft polymerize hydrophilic monomers on the surface of PTFE film by irradiating with ultraviolet rays, that is, peroxide is generated by reaction with moisture after plasma irradiation, and grafting without adding other initiator A technique capable of polymerization is disclosed (for example, see Non-Patent Document 2).

  However, in the case of an inorganic compound, graft polymerization on the surface of the inorganic compound is difficult in the same plasma treatment, and there has been no example of using the plasma-treated inorganic compound instead of the initiator.

  On the other hand, in industrial fields such as automobiles and architecture, a dispersion (paint) of an organic-inorganic composite capable of forming a film having excellent film forming ability and excellent adhesion to a substrate, or There is a demand for a dispersion of an organic-inorganic composite capable of imparting functionality such as a function of adjusting transmitted light using a change in transparency of an organic-inorganic composite dispersion due to a change in external temperature. However, in the above-mentioned patent documents and the like, an organic-inorganic composite dispersion liquid in which particles of an organic-inorganic composite satisfying such characteristics are dispersed in an aqueous medium relates to a production method for producing an initiator-free system. The technology is not disclosed.

  By the way, in Patent Document 5, a polymer of a monomer containing an acrylate monomer having an alkoxyalkyl group in the side chain and one or more inorganic materials selected from water-swellable clay minerals and silica form a three-dimensional network. A technique relating to an organic-inorganic composite dispersion liquid in which organic-inorganic composite particles thus formed are dispersed in an aqueous medium and a method for producing the same is disclosed. However, this technique does not disclose a method for producing an organic-inorganic composite dispersion without using an initiator.

JP2002-53762 JP-A-2004-143212 JP2005-232402 JP 2006-169314 A JP2010-18775

T.J. Pinnavaia and G. W. Beall Eds. "Polymer-Clay Nano Composites", Wiley, 2000. K. L. Tan et al., Macromolecules 1993, 26, 2832-2836

  Therefore, the problem to be solved by the present invention is that organic-inorganic composite particles are stably dispersed in water, have excellent film-forming ability by drying, and have excellent adhesiveness with a substrate. The structure of the organic-inorganic composite particles formed by combining the inorganic substance and the high-molecular polymer and the particle size of the particles are easy to control. An object is to provide a method for producing an organic-inorganic composite dispersion which is an initiator-free system and can be easily produced in a short time.

  Patent Documents 1-4 relate to a technique for manufacturing an organic-inorganic composite hydrogel or a polymer composite through a process in which the entire reaction system gels in the manufacturing process. Based on these techniques, the present inventors have studied various methods for producing a particulate organic-inorganic composite in water while adjusting the concentration of the inorganic substance and the mass ratio of the inorganic substance to the organic polymer. As a result, in addition to the region in which the entire reaction system gels as shown in FIG. 1, the concentration of the monomer and inorganic substance in the reaction system is within a specific range (boundary indicated by the equations (1) and (2) in FIG. 1). The lower region), the reaction system does not gel at all, there is a region where an aqueous dispersion of organic-inorganic composite particles can be produced, and a water-swellable clay mineral used as a polyfunctional crosslinking agent ( It was found that by subjecting B) to a surface treatment with plasma, the monomer (A) can be polymerized without adding an initiator to the reaction solution, and the present invention was completed.

That is, in the present invention, after the (meth) acrylic monomer (A) and the water-swellable clay mineral (B) subjected to the surface treatment by plasma are dissolved or uniformly dispersed in the aqueous medium (C), the polymerization is started. A step of polymerizing the monomer (A) by heating or irradiation with ultraviolet rays without using an agent to form an organic-inorganic composite (X),
An organic-inorganic composite, wherein the concentration (mass%) of the water-swellable clay mineral (B) in the aqueous medium (C) is in a range represented by the following formula (1) or formula (2) A method for producing a dispersion is provided.
Formula (1) When Ra <0.19
Concentration (mass%) of clay mineral (B) <12.4Ra + 0.05
Formula (2) When Ra ≧ 0.19
Concentration (mass%) of clay mineral (B) <0.87Ra + 2.17
(Wherein the concentration (mass%) of the clay mineral (B) is a numerical value obtained by dividing the mass of the clay mineral (B) by the total mass of the aqueous medium (C) and the clay mineral (B) and multiplying by 100, Ra Is the mass ratio of clay mineral (B) to polymer (P) ((B) / (P)).)

  The production method of the present invention has few production steps, does not require expensive equipment investment, and can produce an organic-inorganic composite dispersion easily and in a short time without using a polymerization initiator. In addition, the organic-inorganic composite produced by the production method of the present invention can contain inorganic substances finely and uniformly at a nanometer level and in a wide concentration range, and has good stability and film-forming ability. The obtained film has high transparency, good elastic modulus, flexibility and flexibility. It has the characteristics of being used stably in the atmosphere. The organic-inorganic composite dispersion liquid of the present invention is excellent in the light control function accompanying changes in the environmental temperature, and the film obtained from the dispersion liquid is excellent in anti-fogging properties, so that it can be used in houses, automobiles, etc. It is useful as a surface modifier for various industrial materials and medical / biochemical tools because of its excellent transparency and stretchability.

It is the figure which showed the area | region which can form the organic inorganic composite dispersion liquid which satisfies General formula (1) and (2).

  The (meth) acrylic monomer (A) used in the present invention can be suitably used as long as the polymer interacts with the clay mineral and can form an organic-inorganic composite hydrogel by polymerization. ) Acrylamide and / or derivatives thereof (N- or N, N-substituted (meth) acrylamide) and (meth) acrylic acid esters are preferably used, particularly preferably (meth) acrylamide and / or derivatives thereof (N- Alternatively, N, N-substituted (meth) acrylamide) is used.

  More preferably, (meth) acrylic monomers represented by the following formulas (1) to (6) are used.

（式中、Ｒ_１は水素原子またはメチル基、Ｒ_２及びＲ_３はそれぞれ独立に水素原子又は炭素原子数１〜３のアルキル基、Ｒ_４は炭素原子数１〜２のアルキル基を表し、ｎは１〜９の整数である。）

Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ and R ₃ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ₄ represents an alkyl group having 1 to 2 carbon atoms, n is an integer of 1 to 9.)

One or more of the above acrylic monomers may be mixed and used depending on required mechanical properties and chemical properties. By using the monomer (A), the resulting organic-inorganic composite dispersion liquid has good wettability with respect to a substrate, particularly a hydrophobic substrate, and is thinner, smoother and has a higher quality coating film, and is anti-fogging. If a monomer (A) (for example, N-isopropylacrylamide) to be a polymer (P) having LCST (Lower Critical Solution Temperature) is used, the dispersion temperature of the dispersion increases. A dispersion having an energy-saving dimming function in which the transparency changes can be obtained.
In addition, as other copolymerization monomers, for example, acrylic monomers having an anion group such as a sulfone group or a carboxyl group, cationic groups such as a quaternary ammonium group, to the extent that the physical properties of the organic-inorganic composite hydrogel are not affected. Acrylic monomer having quaternary ammonium group and phosphoric acid group, acrylic monomer having zwitterion group, acrylic monomer having amino acid residue having carboxyl group and amino group, acrylic monomer having sugar residue In addition, an acrylic monomer having a hydroxyl group, polyethylene glycol, an acrylic monomer having a polypropylene glycol chain, an amphiphilic acrylic monomer having a hydrophilic chain such as polyethylene glycol and a hydrophobic group such as a nonylphenyl group, Polyethylene glycol Diacrylate, N, may be used in combination such as N'- methylenebisacrylamide.

  Examples of the water-swellable clay mineral (B) used in the present invention include a swellable clay mineral that can be peeled in layers, and preferably a clay mineral that can swell and uniformly disperse in water or a mixed solution of water and an organic solvent. Particularly preferably, an inorganic clay mineral that can be uniformly dispersed at a molecular level (single layer) or close to that in water is used. Specific examples include water-swellable hectorite containing sodium as an interlayer ion, water-swellable montmorlite, water-swellable saponite, and water-swellable synthetic mica. You may mix and use these clay minerals.

  By using the clay mineral (B), the stability of the dispersion and the film-forming ability are good, and a dry film having excellent antifogging properties can be obtained.

  When producing the organic-inorganic composite dispersion of the present invention, the mass ratio ((B) / (P)) of the polymer (P) and the clay mineral (B) is preferably 0.01 to 10. 0.03 to 5 is more preferable, and 0.05 to 3 is particularly preferable. When the mass ratio ((B) / (P)) is within this range, the resulting dispersion has good stability, and it is easy to obtain a smooth and strong coating with the substrate.

  One characteristic of the organic-inorganic composite dispersion production of the present invention is that the concentration (mass%) of the clay mineral (B) in the aqueous medium is in the range represented by the formula (1) or the formula (2). When the concentration (mass%) of the clay mineral (B) in the aqueous medium exceeds the above range, the polymerization may cause gelation of the entire reaction system or the dispersion becomes non-uniform. Dispersion cannot be produced.

  The aqueous medium (C) used in the present invention is not particularly limited as long as it can contain the monomer (A), the clay mineral (B), etc., and an organic-inorganic composite dispersion liquid with good physical properties can be obtained. For example, it may be water or an aqueous solution containing a solvent miscible with water and / or other compounds, and further includes preservatives and antibacterial agents, coloring agents, fragrances, enzymes, collagen, proteins, sugars, Amino acids, cells, DNAs, salts, water-soluble organic solvents, surfactants, polymer compounds, inorganic compounds, foaming agents, leveling agents and the like can be included.

  The surface treatment method of the clay mineral with plasma in the present invention includes a method of directly irradiating a powdery clay mineral with plasma, or applying an aqueous dispersion of clay mineral to a support and drying to form a thin layer of clay mineral. There is a method of irradiating with plasma after the formation. In the latter case, a more uniform plasma treatment can be performed, and the proportion of the clay mineral to be treated is high, which is preferable. In this case, the thickness of the clay mineral thin layer is preferably 10 μm or less, more preferably 3 μm or less. If the thickness of the thin layer of the water-swellable clay mineral is 10 μm or less, a clay mineral having radicals can be sufficiently generated after plasma irradiation, and a good organic-inorganic composite dispersion can be obtained.

  For plasma irradiation, a known and commonly used plasma irradiation apparatus can be used. For example, a vacuum type plasma processing apparatus, an atmospheric pressure plasma processing apparatus, an atmospheric pressure corona processing apparatus, etc. are mentioned.

As a method of polymerizing the (meth) acrylic monomer (A), a thermal polymerization method by heating for a certain time or a photopolymerization method of irradiating ultraviolet rays is used. Among them, the polymerization method using ultraviolet rays is preferable because it is not heated, the polymerization time is short, and the influence of oxygen is small. The intensity of the irradiated ultraviolet light is preferably 10 to 500 mW / cm ² and the irradiation time is generally about 0.1 to 200 seconds.

The present invention utilizes radicals generated on the surface of a clay mineral (B) used as a polyfunctional crosslinking agent that has been subjected to plasma irradiation without adding any polymerization initiator for thermal polymerization or photopolymerization to the reaction system. Thus, it is another feature of the present invention that the monomer (A) is polymerized.
The organic-inorganic composite dispersion produced by the production method of the present invention may be used as it is as a paint or may be used after undergoing a purification step such as washing with water. In addition, for the purpose of imparting functionality such as coatability, surface smoothness of the dry film, light control performance, and antifogging property, the organic-inorganic composite dispersion is further provided with a leveling agent, surfactant, polymer compound, and colorant. Etc. may be added and used. By using the polymer P having LCST, the organic-inorganic composite dispersion liquid of the present invention can be used as it is as an optical element having a light control function. For example, when natural sunlight hits, the temperature of the dispersion rises above LCST, the dispersion becomes cloudy, blocks natural light, and when sunlight falls off, the ambient temperature drops below LCST. Then, the dispersion liquid becomes transparent and natural light can be transmitted.

  Moreover, a laminated body can be manufactured by apply | coating the organic inorganic composite dispersion liquid of this invention on a support body, and making it a dry film. When applying on the support, it can be applied in a pattern of a specific shape, if necessary.

  Furthermore, by drying the organic-inorganic composite dispersion liquid of the present invention, a transparent dry film having good flexibility and mechanical properties can be obtained. This film may be in a state of being attached to a support (base material) (coating film) or may be an independent film without a support. The thickness of the coating can be arbitrarily adjusted according to the application, and the thickness of the coating as a film is preferably 0.01 mm to 2 mm for ease of handling. If it is this range, the intensity | strength of a film | membrane will be enough, and it will be easy to handle and manufacture of a film | membrane with high surface smoothness will become easy. Further, the thickness of the film adhered to the support is preferably 0.00005 mm (0.05 μm) or more because it can be suitably handled.

  The organic-inorganic composite dispersion liquid of the present invention is applied to a support (for example, a polystyrene container), dried, washed as necessary, and then dried in a state of being attached to the support, thereby producing cells. It can be used as a cell culture substrate having good adhesion, growth and release properties. In addition, by selecting the polymer (P), the cell does not adhere to the culture surface, and can be used as a culture substrate that can be cultured in a floating state (cell low adhesion), and further as a substrate that can suppress protein adsorption. You can also.

  The particle size of the composite particles (X) is preferably 30 nm to 5 μm. More preferably, it is 50 nm-1 micrometer. Within this range, the dispersion is stable, a tougher and smoother film can be formed, and the film thickness can be easily controlled.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, the scope of the present invention is not limited only to these Examples.

  The inventors of the present invention studied various methods for producing a particulate organic-inorganic composite in water while adjusting the concentration of the viscosity mineral and the mass ratio of the clay mineral and the organic polymer. As a result, in addition to the region in which the entire reaction system gels as shown in FIG. 1, the concentrations of the monomer and clay mineral in the reaction system are in a specific range (shown by equations (1) and (2) in FIG. 1). It has been found that there is a region in which the reaction system does not gel at all, and an aqueous dispersion of organic-inorganic composite particles can be produced.

  Furthermore, the present inventors produced a water dispersion of organic-inorganic composite particles by polymerizing the monomer (A) without adding a polymerization initiator to the reaction solution by subjecting the clay mineral to a surface treatment with plasma. I found out that I can do it.

  Each plot in FIG. 1 is Examples 1, 2, 3, 4, 5, 8, 9, and Comparative Examples 1-9. A comparative example is located in the area | region which gelatinizes, and an Example is located in the area | region which does not gel. As can be seen from this, the region that gels and the region that forms particles are separated on the basis of Equation (1) and Equation (2).

Example 1
[Surface treatment of water-swellable clay mineral with plasma]
A clay dispersion (B), 0.5 g Laponite XLG (manufactured by Rockwood Additives Ltd.) and 10 g water as an aqueous medium (C), uniformly mixed with a 6 × 15 cm glass plate, dried clay mineral The thin layer was applied so as to have a thickness of 1 μm and dried at 80 ° C. for 1 hour to prepare a thin layer of clay mineral. A thin layer of clay mineral produced on this glass plate is put into a vacuum type plasma processing apparatus (PR31 type, manufactured by Yamato Scientific Co., Ltd.) and irradiated with plasma at an irradiation intensity of 60 W in an argon gas atmosphere for 5 minutes. A plasma-treated clay mineral (B1) was prepared.
[Preparation of reaction liquid (E) containing monomer (A), clay mineral (B) and aqueous medium (C)]
0.6 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd.) as monomer (A), 0.02 g of plasma-treated clay mineral (B1) as clay mineral (B), and 10 g of water as aqueous medium (C) are uniformly mixed. Thus, a reaction solution (E1) was prepared.

[Preparation of dispersion liquid of organic-inorganic composite complex X]
While stirring the reaction liquid (E1) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare a substantially transparent organic-inorganic composite X dispersion liquid (1).
Ra = 0.03 of this reaction system, concentration (mass%) of inorganic material (B) = 0.20 (%) <12.4Ra + 0.05 = 0.42
When the container containing the dispersion (1) was placed in a water tank and the temperature of the water tank was raised from room temperature at a rate of temperature increase of 1 ° C./3 minutes, the cloudiness start temperature (LCST) of the dispersion was measured. The LCST of the dispersion (1) was about 32 ° C.
About the said organic inorganic composite dispersion liquid (1), when the particle size distribution was measured using the particle size distribution measuring apparatus (Microtrac UPA150 type, Nikkiso Co., Ltd. product), the average particle diameter was 60 nm.

(Example 2)
[Preparation of reaction liquid (E) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
Reaction is performed by uniformly mixing 0.5 g of acryloylmorpholine (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.15 g of the plasma treated clay mineral (B1) as the clay mineral (B), and 10 g of water as the aqueous medium (C). A liquid (E2) was prepared.

[Preparation of dispersion liquid of organic-inorganic composite complex X]
While stirring the reaction liquid (E2) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare a substantially transparent organic-inorganic composite dispersion liquid (2).

Ra = 0.30 of this reaction system, concentration (mass%) of inorganic material (B) = 1.48 (%) <0.87 Ra + 2.17 = 2.43
Since the polymer P of this example does not have LCST, the dispersion (2) also did not show LCST.
When the particle size distribution of the organic-inorganic composite dispersion liquid (2) was measured using a particle size distribution analyzer (Microtrac UPA150 type, manufactured by Nikkiso Co., Ltd.), the average particle size was 50 nm.

(Example 3)
[Preparation of reaction liquid (E) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
Uniformly, 0.18 g of N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.32 g of the plasma treated clay mineral (B1) as the clay mineral (B), and 10 g of water as the aqueous medium (C) The reaction solution (E3) was prepared by mixing.

[Preparation of dispersion liquid of organic-inorganic composite complex X]
While stirring the reaction liquid (E3) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare a substantially transparent organic-inorganic composite X dispersion liquid (3).

Ra = 1.8 in this reaction system, concentration (mass%) of clay mineral (B) = 3.10 (%) <0.87Ra + 2.17 = 3.74
Since the polymer P of this example does not have LCST, the dispersion (3) also did not show LCST.
With respect to the organic-inorganic composite dispersion liquid (3), the particle size distribution was measured using a particle size distribution analyzer (Microtrac UPA150 type, manufactured by Nikkiso Co., Ltd.), and the average particle size was 50 nm.

Example 4
[Preparation of reaction liquid (E) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
Uniform mixing of 0.28 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd.) as monomer (A), 0.02 g of plasma-treated clay mineral (B1) as clay mineral (B), and 10 g of water as aqueous medium (C) Thus, a reaction solution (E4) was prepared.

[Preparation of dispersion liquid of organic-inorganic composite complex X]
While stirring the reaction liquid (E4) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare an almost transparent dispersion liquid (4) of the organic-inorganic composite X.
The organic-inorganic composite dispersion (4) was allowed to stand at room temperature (about 23 ° C.) for 3 months in a glass screw tube and sealed, and there was no precipitation or change in particle size distribution.
Ra = 0.07 of this reaction system, concentration (mass%) of clay mineral (B) = 0.20 (%) <12.4Ra + 0.05 = 0.92
With respect to the organic-inorganic composite dispersion liquid (4), the particle size distribution was measured using a particle size distribution measuring device (Microtrac UPA150 type, manufactured by Nikkiso Co., Ltd.), and the average particle size was 40 nm.
The container containing the dispersion (4) was placed in a water tank, and when the temperature of the water tank was raised from room temperature at a temperature increase rate of 1 ° C./3 minutes, the cloudiness start temperature (LCST) of the dispersion was measured. The LCST of the dispersion (4) was about 32 ° C.

(Example 5)
[Preparation of reaction liquid (E) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
As a monomer (A), 0.21 g of N-methylacrylamide (manufactured by Kojin Co., Ltd.), 0.04 g of plasma-treated clay mineral (B1) as a clay mineral (B), and 10 g of water as an aqueous medium (C) are uniformly mixed. To prepare a reaction solution (E5).

[Preparation of dispersion liquid of organic-inorganic composite complex X]
While stirring the reaction liquid (E5) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare a substantially transparent organic-inorganic composite X dispersion liquid (5).
Ra = 0.19 of this reaction system, concentration (mass%) of clay mineral (B) = 0.4 (%) <0.87 Ra + 2.17 = 2.34
With respect to the organic-inorganic composite dispersion liquid (5), the particle size distribution was measured using a particle size distribution measuring device (Microtrac UPA150 type, manufactured by Nikkiso Co., Ltd.), and the average particle size was 40 nm.
Since the polymer P of this example does not have LCST, the dispersion (5) also did not show LCST.

(Example 6)
This example shows an example in which a dispersion having LCST is applied to an optical element.

  A pair glass-like pseudo window is produced using a plate-like glass having a length of 100 × 100 mm and a thickness of 2 mm, and a glass having a length of 100 mm, a width of 5 mm, and a thickness of 2 mm as spacers. The liquid (4) was poured between the plate glasses and sealed to produce an optical element having a light control function.

  When the transmittance of visible light was measured using this optical element, the transmittance was about 96%. On the other hand, this optical element was put in 40 ° C. warm water, and after a few seconds, the entire glass became cloudy. When the transmittance of visible light was measured, the transmittance was almost 0%.

  Furthermore, when this optical element was placed near a window and exposed to sunlight, it was observed that the entire glass gradually became cloudy.

  From the above Example 6, by applying sunlight to this optical element, the temperature of the internal dispersion gradually rises, and when LCST (32 ° C.) is reached, the entire glass becomes cloudy and functions to block sunlight. You can understand that

(Example 7)
In this example, a dry film made of a dispersion liquid without LCST is used as an antifogging material.

  The dispersion liquid (5) of Example 5 was applied to a glass plate so as to have a thickness of about 200 μm, and dried at 80 ° C. for 60 minutes to prepare an antifogging coating film 7. The thickness of the dried film of the organic-inorganic composite after drying was about 5 μm. When this anti-fogging coating film 7 is visually observed, it can be seen that the anti-fogging coating film 7 has transparency equivalent to that before application, and the dry coating film has high transparency.

  Using a cutter knife on this coating, cut a 1 x 1 mm square grid, and then strongly press the cellophane tape on the grid, and pull the end of the tape rapidly at an angle of 45 °. When peeling and observing the state of the grid, it was confirmed that the coating film did not peel at all and the adhesiveness with the substrate was good.

  Further, when this antifogging coating film 7 was exposed to water vapor generated from water at 50 ° C. for about 1 minute (distance between the coating film and the water surface was about 5 cm), the coating film was not fogged at all.

  From this example, it can be seen that the coating film of the organic-inorganic composite containing the hydrophilic polymer has good adhesion to the substrate and has antifogging properties.

(Example 8)
[Preparation of reaction liquid (E) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) 0.223 g as the monomer (A), 0.165 g of polyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.), water-swellable clay mineral (B) The reaction solution (E8) was prepared by uniformly mixing 0.02 g of the plasma-treated clay mineral (B1) and 10 g of water as the aqueous medium (C).

[Preparation of dispersion liquid of organic-inorganic composite complex X]
While stirring the reaction liquid (E8) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare a substantially transparent organic-inorganic composite X dispersion liquid (8).
Ra = 0.05 in this reaction system, concentration (mass%) of clay mineral (B) = 0.20 (%) <12.4Ra + 0.05 = 0.67
With respect to the organic-inorganic composite dispersion liquid (8), the particle size distribution was measured using a particle size distribution analyzer (Microtrac UPA150 type, manufactured by Nikkiso Co., Ltd.), and the average particle size was 50 nm.

The dispersion (8) was cast on a 35 mm polystyrene petri dish (manufactured by AGC Techno Glass Co., Ltd.) to a thickness of 50 μm, dried at 80 ° C. for 20 minutes, washed with sterile water, and then sterilized bag The petri dish was dried inside to obtain a cell culture substrate (8). When this culture substrate 8 is visually observed, it can be seen that it has a transparency equivalent to that before application, and the dried film has a high transparency.

[Suspension culture of mouse macrophage cells (J744.1)]
An appropriate amount of DMEM medium (Bio West) supplemented with 10% bovine serum is added to the obtained cell culture substrate 8, and mouse macrophage cells (J744.1) are seeded (seeding concentration is 2 × 10 ^5). The culture was performed in 5% carbon dioxide at 37 ° C. for 3 days. Next, the medium and floating cells in the petri dish were sucked up, rinsed once with a PBS buffer, and then confirmed for cell adhesion on the petri dish surface with a microscope. The cells were completely washed away with the PBS buffer. No adherent cells were observed.
On the other hand, when a similar culture test was performed using a 35 mm polystyrene petri dish (manufactured by AGC Techno Glass Co., Ltd.), almost all mouse macrophage cells were adhered to the petri dish.
From the above examples, it can be understood that the culture substrate 8 is cultured in a floating state without cells adhering to the petri dish surface.

Example 9
[Preparation of reaction liquid (E) containing monomer (A), other monomers, water-swellable clay mineral (B), aqueous medium (C)]
0.27 g of 2-methoxyethyl acrylate (manufactured by Toagosei Co., Ltd.) as monomer (A), 0.18 g of methoxypolyethylene glycol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) as other monomer, and plasma treatment as clay mineral (B) 0.02 g of clay mineral (B1) and 10 g of water as the aqueous medium (C) were uniformly mixed to prepare a reaction liquid (E9).

[Preparation of organic / inorganic composite dispersion]
While stirring the reaction liquid (E9) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare an organic-inorganic composite dispersion liquid (9) having a slightly milky white color.

With respect to the organic-inorganic composite dispersion liquid (9), the particle size distribution was measured using a particle size distribution analyzer (Microtrac UPA150 type, manufactured by Nikkiso Co., Ltd.), and the average particle size was 70 nm.
In this reaction system, Ra = 0.074, the concentration (mass%) of the clay mineral (B) = 0.20 (%) <12.4 Ra + 0.05 = 0.97

[Preparation of cell culture substrate]
The dispersion (9) was cast on a 35 mm polystyrene petri dish (manufactured by AGC Techno Glass Co., Ltd.) to a thickness of 50 μm, dried at 80 ° C. for 20 minutes, washed with sterilized water, and sterilized bag. The petri dish was dried inside to obtain a cell culture substrate (9).
[Culture of normal human dermal fibroblasts]
An appropriate amount of CS-C complete medium (Cell Systems Inc. medium) is added to the obtained cell culture substrate (9), and normal human dermal fibroblasts are seeded (seeding concentration is 1.2 × 10 ⁴ cells). / Cm ² ) The cells were cultured at 37 ° C. in 5% carbon dioxide. When the cells grown for 5 days were confirmed with a microscope, it was observed that the cells were covered with the entire surface of the petri dish. Next, the medium in the petri dish was sucked up, a medium at 4 ° C. was added, and allowed to stand for a certain time, and the proliferated cells were naturally detached. As a result, the cells gradually detached, and almost all the cells detached in a thin film form in about 20 minutes.

  From Example 9 above, the surface coated with the dispersion liquid (9) shows adhesion to cells at 37 ° C., and the cells can proliferate, but the cells naturally peel off from the coating surface by lowering the temperature. Can understand.

(Example 10)
This example shows an application example in which a dry film made of a dispersion is used as a protein adsorption preventing material.

[Protein adsorption test]
1 ml of an immunoglobulin G (IgG) aqueous solution having a concentration of 0.2 μg / ml is placed in the cell culture substrate 8 produced in Example 8 above, and left at room temperature for 3 hours to adsorb IgG. Next, the IgG aqueous solution in the petri dish was sucked up and rinsed three times with PBS buffer. Then, 1 ml of TMB color former (manufactured by KPL) was added, left to stand for 2 minutes, and 1 ml of 1N hydrochloric acid was further added (the surface of the petri dish). When protein remains in the color). This solution was measured for absorbance at 450 nm using an ultraviolet-visible spectrophotometer (manufactured by Hitachi, Ltd.) to evaluate the degree of protein adsorption. As a result, the absorbance was 0.2.
On the other hand, when a similar protein adsorption test was performed using a 35 mm polystyrene petri dish (manufactured by AGC Techno Glass Co., Ltd.), the absorbance was 2.0.

  From Example 10 above, it can be understood that protein adsorption was greatly suppressed by forming a dry film made of the dispersion (8) on the surface of the PS petri dish.

(Example 11)
This example is an example of producing a cell culture substrate.
[Preparation of reaction liquid (E) containing monomer (A), clay mineral (B) and aqueous medium (C)]
Uniformly, 0.32 g of 2-methoxyethyl acrylate (manufactured by Toagosei Co., Ltd.) as monomer (A), 0.08 g of plasma-treated clay mineral (B1) as clay mineral (B), and 10 g of water as aqueous medium (C) A reaction solution (E11) was prepared by mixing.

[Preparation of organic / inorganic composite dispersion]
While stirring the reaction liquid (E11) with a magnetic stirrer, ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² was irradiated for 180 seconds to prepare an organic-inorganic composite dispersion liquid (11) having a slightly milky white color.

Ra = 0.25 in this reaction system, concentration (mass%) of inorganic material (C) = 0.79 (%) <0.87 Ra + 2.17 = 2.39

[Preparation of aqueous solution of polymer P having LCST]
As monomer (A), 1.7 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd.), 10 g of water, 1-hydroxycyclohexyl phenyl ketone “Irgacure 184” (polymerization initiator, manufactured by Ciba Geigy), 140 μl of 2 wt% methanol solution, Then, the glass container containing the aqueous solution was cooled (about 10 ° C.) and irradiated with ultraviolet rays having an ultraviolet intensity of 365 m at 40 mW / cm ² for 180 seconds to prepare an aqueous solution of poly N-isopropylacrylamide. . After adding 5 g of water to this aqueous solution and mixing it uniformly, the viscosity of this solution was measured using a DIGITAL VISCOMATE viscometer (MODEL VM-100A, manufactured by Yamaichi Electronics Co., Ltd.). The viscosity was 368 mPa · s. Met. The solution temperature at the time of measurement was 24.2 ° C.

Furthermore, as a result of measuring with Shodex GPC System-21 apparatus (made by Showa Denko KK), the weight average molecular weight Mw of this poly N-isopropylacrylamide was 3.40 × 10 ⁶ . An N, N-dimethylformamide (DMF) solution containing 10 mmol / L LiBr was used as a solvent for the measurement. STANDARD SH-75 and SM-105 kit (manufactured by Showa Denko KK) were used as polystyrene standard substances used for the calculation of molecular weight.
[Preparation of cell culture substrate]
To the total amount of the dispersion (11), 1.0 g (0.1 g solid content) of the above poly N-isopropylacrylamide aqueous solution was added and mixed uniformly, and then a 60 mm polystyrene petri dish (Asahi Techno Glass Co., Ltd.) had a thickness of 50 μm. Then, the petri dish was washed with sterilized water and dried in a sterile bag to obtain a cell culture substrate (11).
[Culture of normal human dermal fibroblasts]
Normal human dermal fibroblasts were cultured on the obtained cell culture substrate 11 in the same manner as in Example 9. After confirming that the cells had sufficiently proliferated, the medium (at 37 ° C.) was replaced with a medium at 4 ° C. and allowed to stand for a certain period of time to allow the grown cells to spontaneously detach. As a result, the cells gradually detached, and almost all the cells detached in a thin film form in about 7 minutes.

  From Example 11 above, the surface coated with the dispersion (11) containing poly N-isopropylacrylamide having LCST shows adhesion to cells at 37 ° C., and the cells can grow, but by lowering the temperature, It can be understood that the cells naturally detach from the coating surface.

(Comparative Example 1)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
1.8 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.018 g of the plasma treated clay mineral (B1) as the clay mineral (B), and bubbling with nitrogen as the aqueous medium (C) in advance with oxygen 10 g of the removed water was uniformly mixed to prepare a reaction solution (S1).

When the said reaction liquid (S1) was stirred at 60 degreeC for 15 hours, the whole reaction liquid gelatinized. Even if this gel was put in a large amount of water and stirred for a long time, the gel did not dissolve or disperse and remained as a gel.
Ra = 0.01 of this reaction system, concentration (mass%) of clay mineral (B) = 0.18> 12.4Ra + 0.05 = 0.17

(Comparative Example 2)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
1.7 g of N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.05 g of the plasma treated clay mineral (B1) as the clay mineral (B), and nitrogen as the aqueous medium (C) are previously bubbled. A reaction solution (S2) was prepared by uniformly mixing 10 g of water from which oxygen was removed.

  When the said reaction liquid (S2) was stirred at 60 degreeC for 15 hours, the whole reaction liquid gelatinized. Even if this gel was put in a large amount of water and stirred for a long time, the gel did not dissolve or disperse and remained as a gel.

  Ra = 0.03 of this reaction system, concentration (mass%) of clay mineral (B) = 0.50> 12.4Ra + 0.05 = 0.42

(Comparative Example 3)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
The reaction solution (as in Reference Example 2 above) except that 1.3 g of N-methylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A) and 0.08 g of the plasma-treated clay mineral (B1) as the clay mineral (B) ( S3) was prepared.

  When the said reaction liquid (S3) was stirred at 60 degreeC for 15 hours, the whole reaction liquid gelatinized. Even when this gel was placed in a large amount of water and stirred for a long time, it did not dissolve or disperse and remained as a gel.

  Ra = 0.06 of this reaction system, concentration (mass%) of clay mineral (B) = 0.79 = 12.4Ra + 0.05 = 0.79

(Comparative Example 4)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
Reaction solution (S4) in the same manner as in Reference Example 2 except that 1.28 g of acryloylmorpholine (manufactured by Kojin Co., Ltd.) as monomer (A) and 0.16 g of plasma-treated clay mineral (B1) as clay mineral (B) Was prepared.

  When the reaction solution (S4) was stirred at 60 ° C. for 15 hours, almost the whole gelled. Even when this gel was placed in a large amount of water, it did not dissolve or disperse and remained as a gel.

  Ra = 0.125 of this reaction system, concentration (mass%) of clay mineral (B) = 1.60 = 12.4Ra + 0.05 = 1.60

(Comparative Example 5)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
1.28 g of N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.24 g of the plasma treated clay mineral (B1) as the clay mineral (B), and 10 g of water as the aqueous medium (C) The reaction solution (S5) was prepared by mixing.

When the reaction liquid (S5) was stirred with a magnetic stirrer and irradiated with ultraviolet light having an ultraviolet intensity at 365 nm of 40 mW / cm ² for 180 seconds, the entire reaction liquid was gelled. Even when this gel was placed in a large amount of water, it did not dissolve or disperse and remained as a gel.

  Ra = 0.19 of this reaction system, concentration (mass%) of the clay mineral (B) = 2.34% = 0.87Ra + 2.17 = 2.34

(Comparative Example 6)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) 0.22 g as the monomer (A), 0.40 g of the plasma treated clay mineral (B1) as the clay mineral (B), and 10 g of water as the aqueous medium (C). The reaction solution (S6) was prepared by mixing.

When the reaction solution (S6) was stirred with a magnetic stirrer and irradiated with ultraviolet rays having an ultraviolet intensity of 365 m at 40 mW / cm ² for 180 seconds, the entire reaction solution was gelled. Even when this gel was placed in a large amount of water, it did not dissolve or disperse and remained as a gel.

  Ra = 1.82 of this reaction system, concentration (mass%) of clay mineral (B) = 3.85%> 0.87Ra + 2.17 = 3.75

(Comparative Example 7)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) 3.2 g as the monomer (A), 0.16 g of the plasma treated clay mineral (B1) as the clay mineral (B), and 10 g of water as the aqueous medium (C) The reaction solution (S7) was prepared by mixing.

When the reaction solution (S7) was stirred with a magnetic stirrer and irradiated with ultraviolet rays having an ultraviolet intensity at 365 nm of 40 mW / cm ² for 180 seconds, the entire reaction solution gelled. Even when this gel was placed in a large amount of water, it did not dissolve or disperse and remained as a gel.
Ra = 0.05 of this reaction system, concentration (mass%) of clay mineral (B) = 1.57> 12.4Ra + 0.05 = 0.67

(Comparative Example 8)
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
0.64 g of N, N-dimethylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.64 g of the plasma treated clay mineral (B1) as the clay mineral (B), and 10 g of water as the aqueous medium (C) The reaction solution (S8) was prepared by mixing.
When the reaction solution (S8) was stirred with a magnetic stirrer and irradiated with ultraviolet rays having an ultraviolet intensity at 365 nm of 40 mW / cm ² for 180 seconds, the entire reaction solution gelled. Even when this gel was placed in a large amount of water, it did not dissolve or disperse and remained as a gel.
Ra = 1.0 of this reaction system, concentration (mass%) of clay mineral (B) = 6.02> 0.87Ra + 2.17 = 3.04

(Comparative Example 9)
[Preparation of dispersion (S) containing monomer (A), clay mineral (B), and aqueous medium (C)]
1.13 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd.) as monomer (A), 0.4 g of plasma-treated clay mineral (B1) as clay mineral (B), and 10 g of water as aqueous medium (C) are uniformly mixed. Thus, a reaction solution (S9) was prepared.
[Preparation of dispersion liquid of organic-inorganic composite complex X]
When the reaction solution (S9) was stirred with a magnetic stirrer and irradiated with ultraviolet rays having an ultraviolet intensity of 365 m at 40 mW / cm ² for 180 seconds, the entire reaction solution was completely gelled. Even when this gel was placed in a large amount of water, it did not dissolve or disperse and remained as a gel.
Ra = 0.35 of this reaction system, concentration (mass%) of clay mineral (B) = 3.85 (%)> 0.87Ra + 2.17 = 2.47

(Comparative Example 10)
This comparative example is an example using a clay mineral not subjected to surface treatment with plasma.
[Preparation of dispersion (S) containing monomer (A), water-swellable clay mineral (B), and aqueous medium (C)]
1.13 g of N-isopropylacrylamide (manufactured by Kojin Co., Ltd.) as the monomer (A), 0.4 g of Laponite XLG (manufactured by Rockwood Additives Ltd.) as the clay mineral (B), and 10 g of water as the aqueous medium (C) To prepare a dispersion (S10).
When the dispersion (S10) was stirred with a magnetic stirrer and irradiated with ultraviolet rays having an ultraviolet intensity at 365 nm of 40 mW / cm ² for 180 seconds, the dispersion (S10) did not gel and the monomer (A) was polymerized. I did not.

  From this comparative example, it can be understood that if the clay mineral is not subjected to plasma surface treatment, in the initiator-free system, the monomer is not polymerized and the dispersion of the organic-inorganic composite X cannot be obtained.

  From the above examples and comparative examples, the organic-inorganic composite dispersion liquid of the present invention can be easily controlled in particle size, has good stability of the dispersion liquid, and has good adhesion to a substrate such as plastic or glass. Moreover, the dry film obtained by drying this composite dispersion has high transparency and excellent antifogging properties. Furthermore, according to the production method, clay minerals and organic polymers can be combined in different structures in a very short time and in a wide range of clay mineral content without using a polymerization initiator, and excellent dispersion It was clear that organic-inorganic composite dispersions exhibiting stability and film-forming ability can be produced.

Claims (5)

At least one water-swellable clay mineral selected from (meth) acrylic monomer (A), water-swellable hectorite surface-treated with plasma , water-swellable montmorillonite, water-swellable saponite and water-swellable synthetic mica ( After dissolving or uniformly dispersing B) in the aqueous medium (C), the monomer (A) is polymerized by irradiation with ultraviolet rays without using a polymerization initiator to form an organic-inorganic composite (X). Including a step, wherein the concentration (mass%) of the water-swellable clay mineral (B) in the aqueous medium (C) is in a range represented by the following formula (1) or formula (2). A method for producing an organic-inorganic composite dispersion.
Formula (1) When Ra <0.19
Concentration (mass%) of clay mineral (B) <12.4Ra + 0.05
Formula (2) When Ra ≧ 0.19
Concentration (mass%) of clay mineral (B) <0.87Ra + 2.17
(Wherein the concentration (mass%) of the clay mineral (B) is a numerical value obtained by dividing the mass of the clay mineral (B) by the total mass of the aqueous medium (C) and the clay mineral (B) and multiplying by 100, Ra Is the mass ratio of clay mineral (B) to polymer (P) ((B) / (P)).) The organic-inorganic composite dispersion according to claim 1, wherein the (meth) acrylic monomer (A) is at least one selected from the group consisting of (meth) acrylamide, derivatives thereof, or (meth) acrylic acid esters. Liquid manufacturing method. The method for producing an organic-inorganic composite dispersion according to claim 1, wherein the (meth) acrylic monomer (A) is at least one selected from the following formulas (1) to (6).

Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ and R ₃ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ₄ represents an alkyl group having 1 to 2 carbon atoms, n is an integer of 1 to 9.) The method for producing an organic-inorganic composite dispersion liquid according to any one of claims 1 to 3 , wherein an average particle diameter of the organic-inorganic composite particles (X) is 50 nm to 5 µm. Polymer (P) and the mass ratio of the water swelling clay mineral (B) of the monomer (A) ((B) / (P)) is, according to claim 1-4 in the range of 0.01 to 10 The manufacturing method of the organic inorganic composite dispersion liquid in any one of.

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