JP2003286306A - Manufacturing method of nano composite resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of transparent resin composition capable of realizing rigidity improvement. <P>SOLUTION: This manufacturing method of a nano composite resin composition comprises irradiation of 10-10,000 KHz sound wave to a mixed solution comprising a resin monomer, a surface modifying silica composition, and a solvent, then polymerization of the resin monomer to a polymer, and removal of the solvent to recover a resin composition, and the surface modifying silica composition is compounded in the range of 3-100 pts.mass to 100 pts.mass resin monomer, and has a modification coefficient of 0.44-8. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a resin composition suitable for replacing inorganic glass or the like.
More specifically, in the present invention, a resin monomer, a specific amount of a surface-modified silica composition having a specific modification coefficient, and a solvent are mixed to obtain a mixed solution, and the mixed solution is irradiated with a sound wave of a specific frequency. After that, by polymerizing the resin monomer to polymerize it, without deteriorating the light transmittance of the resin,
The present invention relates to a method for producing a nanocomposite transparent resin composition containing a surface-modified silica composition capable of improving the rigidity of a member and reducing thermal expansion.

[0002]

2. Description of the Related Art In a transparent material member, a resin material has an advantage that it is lighter in weight and has a higher degree of freedom in molding than an inorganic material, but on the other hand, since its elastic modulus is small, its rigidity is low and its thermal expansion coefficient is large. In addition, since the hardness is low, the surface is easily scratched. For this reason, transparent resin materials have been conventionally used for small parts such as headlamps and sunroofs that have relatively low rigidity and are easy to surface-treat in automobiles. Has not yet fulfilled the prescribed functions, and has not yet been adopted in earnest.

In order to overcome such drawbacks of the transparent resin material, an inorganic / organic fine particle material is blended with the transparent resin.
Research and development of inorganic nanocomposite materials have become active, and various methods have been proposed. For example, JP-A-11-34
Japanese Patent No. 3349 discloses a transparent resin composition in which inorganic silica fine particles are dispersed and mixed in a transparent amorphous organic polymer (transparent resin) for the purpose of ensuring strength or rigidity and transparency of a resin window. A resin window made of is disclosed. Further, in the above publication, for example,
In Example 1, a resin composition is obtained by mixing benzoyl peroxide as a polymerization initiator with methyl methacrylate, heating the mixture, and then performing polymerization reaction while dropping silica fine particles dispersed in a methyl ethyl ketone solvent. Is described.

[0004]

However, while the transparent resin composition disclosed in the above publication has the effect of increasing the surface hardness while maintaining high transparency, on the other hand The increasing effect, in other words, the effect of improving the rigidity, is not always sufficient, and has not yet been applied to window glass. More specifically, the flexural modulus of the composite resin material containing the silica fine particles is 3,500 MPa of the maximum value in Example 11, whereas the composite resin material containing no silica particles (polymethyl methyl ester) is the maximum. (Methacrylate resin) has a flexural modulus of 3,
It is 200 MPa (Reference Example 1), and the increase rate of the bending elastic modulus due to the addition of the silica fine particles is only 9.4%. It is considered that this is because the interaction between the resin and the silica fine particles is not sufficiently exerted.

That is, since conventional organic glass and composite resin materials have lower strength and rigidity than inorganic materials, they are intended to be applied to large parts such as automobile window glass which require a certain degree of rigidity. In this case, it is necessary to increase the thickness, but in such a case, although the degree of freedom in shape can be secured, the effect of weight reduction, which is a major aim of resinification, is diminished.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a resin composition which is particularly excellent in transparency and which can realize an improvement in elastic modulus.

Further, the resin material has a higher coefficient of thermal expansion than the inorganic material. Therefore, when it is applied to a large part such as a window glass of an automobile, the glass material is deformed due to thermal strain with the steel material of the window frame. There is a problem of cracking itself, so it is necessary to design the structure to avoid thermal strain. Therefore, an object of the present invention is to provide a method for producing a resin composition that can reduce the coefficient of thermal expansion of the resin material.

In addition, in the conventional method of blending the inorganic filler as one means for simultaneously achieving the improvement of the elastic modulus and the reduction of the thermal expansion coefficient, the improvement of the elastic modulus of the member and the reduction of the thermal expansion coefficient are not achieved. Although it can be achieved, the problem of transparency of the member occurs due to increase in reflection / scattering and absorption of transmitted light. These are in a trade-off relationship where one is better and the other is worse. Therefore, it is an object of the present invention to provide a method for producing a resin composition that can improve the elastic modulus of a resin member and reduce the coefficient of thermal expansion while maintaining transparency.

[0009]

The above object can be achieved by the following means. That is, a mixed solution of a resin monomer, a surface-modified silica composition and a solvent is added with 10 to 1
After irradiating a sound wave of 0000 KHz, the resin monomer is polymerized to be polymerized, and then the solvent is removed to obtain a resin composition. The surface-modified silica composition comprises 100 parts by mass of the resin monomer. On the other hand, the method for producing a nanocomposite resin composition is characterized in that it is compounded in a range of 3 to 100 parts by mass and has a modification coefficient of 0.44 to 8.

[0010]

As a result of intensive investigations in view of these problems, the inventors of the present invention focused on appropriate material selection and surface modification of an inorganic compounding material for uniformly dispersing it in a base material resin,
Further studies were made on the method of uniformly dispersing. As a result, in addition to the selection of these materials and their surface modification, it was found that the manufacturing process is deeply involved in the performance of the composite resin composition, and as a measure for improving the performance, sonication is performed before resin polymerization. I found a new technique. In detail, in order to increase the mechanical strength of the composite resin composition, the water molecules attached to the silanol groups (-Si-OH) of the silica composition are released, and the silanol groups and the carbonyl contained in the resin skeleton are released. It is necessary to more strongly form a hydrogen bond with a functional group such as a group (-C = O). At this time, as an effective technique for releasing the water molecules attached to the silanol groups (-Si-OH) of the silica composition, that is, for breaking the hydrogen bonds of the water molecules, there is a paragraph in JP-A-2000-321793. Nos. "0007" to "0013" and Japanese Patent Laid-Open No. 2000-
Paragraph numbers "0006" to "001" of Japanese Patent No. 345195.
There is sonication, as described in "0". More specifically, in the above-mentioned publication, "water forms a cluster by binding a plurality of water molecules by hydrogen bonds (Japanese Patent Application Laid-Open No. 2000-3.
Paragraph No. “0007” of Japanese Patent No.
In paragraph No. “0006” of Japanese Patent Application Laid-Open No. 00-345195), when a sound wave or light is applied, hydrogen bonds are broken and the clusters are subdivided (JP 2000-321793 A).
Paragraph No. “0013” of Japanese Patent Laid-Open No. 2000-34
It is described that the mechanism described in paragraph No. “0010” of Japanese Patent No. 5195) is used for oxidation treatment of members and functionalization of water. The inventors of the present invention focused on such sonication, and sonicated a solution prepared by mixing a monomer of a base material resin and an inorganic compounding material which was appropriately surface-modified at a specific ratio, and hydrogenated water molecules. By breaking the bond and strengthening the hydrogen bond between the silanol group of the silica composition and the functional group such as carbonyl contained in the resin skeleton, by polymerizing the monomer, the inorganic compounding material becomes uniform in the base material resin. The present invention has been accomplished by discovering a new means for simultaneously improving the elastic modulus and reducing the thermal expansion coefficient while dispersing and maintaining high transparency. The effects of the present invention will be described below for each claim.

According to the first aspect of the present invention, a silanol group contained in the surface-modified silica composition is obtained by treating a mixed solution in which a resin monomer and the surface-modified silica composition are dissolved / dispersed in a solvent with a specific sound wave. After removing the adhering water in the, the silanol group and the functional group contained in the resin monomer are reacted to form a hydrogen bond more firmly, by polymerizing the resin monomer, the nanoparticle with excellent mechanical strength is formed. A composite resin composition is obtained. Further, unlike a clayey inorganic filler such as montmorillonite, it is possible to obtain a resin composition which can prevent coloring and is excellent in transparency.

According to a second aspect of the present invention, a silicone compound having a functional group reactive with a hydrophobic group and a silanol group is used for surface modification of fine particle silica to improve compatibility with a resin monomer. It is possible to more evenly and finely disperse the silica composition in the resin.

According to a third aspect of the present invention, the particle size of the silica composition is set to a wavelength of visible light (380 nm) or less, so that the transmission of visible light is not hindered, and therefore the silica composition is finely dispersed in the base resin. It is possible to improve the elastic modulus and reduce the thermal expansion coefficient of the transparent resin member while maintaining transparency.

According to the present invention, the average primary particle diameter of the silica composition is reduced to ensure excellent transparency.

According to the fifth aspect, the transparency is particularly excellent by selecting a specific polymer material.

According to the sixth aspect, by selecting a specific polymer material, the transparency and the weather resistance are particularly excellent.

The nanocomposite resin composition of the present invention has been developed and studied by paying attention to the enhancement of the hydrogen bond between the two in addition to the improvement of the affinity of silica as an inorganic component compounded in the matrix resin. As a result, they have found a method capable of improving the strength and reducing the linear expansion coefficient without impairing the transparency. If this material is used for industrial applications such as automobiles, home appliances, and houses,
It is possible to reduce the weight of members and increase the degree of freedom in molding. For example, if you use it in the window of the car already mentioned,
It can be used as an alternative to inorganic glass and can greatly contribute to weight reduction of vehicles and creation of new designs. Furthermore, in addition to being able to achieve weight reduction in vehicle applications, it also contributes to the conservation of the global environment from fuel efficiency and CO ₂ emission reduction.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The first aspect of the present invention is to provide a resin monomer,
A mixed solution of the surface-modified silica composition and a solvent (also referred to simply as “mixed solution” in the present specification) contains 10 to 10 parts of the mixed solution.
After irradiating a sound wave of 10000 KHz, the resin monomer is polymerized to be polymerized, and then the solvent is removed to obtain a resin composition. At this time, the surface-modified silica composition is 100 parts by mass of the resin monomer. Is a compounding amount in the range of 3 to 100 parts by mass, and has a modification coefficient of 0.44 to 8.

One embodiment of the method of the present invention will be briefly described. That is, first, in a reaction container such as a flask, an organic solvent such as toluene, a resin monomer such as methyl methacrylate (MMA), a polymerization initiator such as AIBN (azobisisobutyronitrile), and a surface modification (hydrophobicization) treatment. The silica composition prepared above is added and stirred with a stir bar to obtain a homogeneous mixed dispersion solution. Next, to the mixed dispersion solution in this flask,
While stirring with a stirrer, a predetermined sound wave is applied by a sonic oscillator to remove the attached water that hydrogen bonds with the silanol group remaining in the silica composition, and the silanol group is reacted with a functional group such as a carbonyl group of the resin monomer. Form a hydrogen bond. Then, the air in the flask was replaced with an inert gas such as nitrogen to seal the system, and the monomers were reacted and polymerized at a predetermined temperature and for a time to give a composite resin composition containing surface-modified fine particle silica. obtain.

According to the method of the present invention, the mixed solution is mixed with 10 to 10 parts.
It is essential to include a step of irradiating a sound wave of 000 KHz.

That is, one of the features of the method of the present invention is that sonication is performed at a specific frequency after the material is charged and before the polymerization. More specifically, since the silanol groups remaining in the surface-modified silica composition have high hydrophilicity,
At room temperature, when 4 to 5 water molecules associate with each other through hydrogen bonds to form water and contact with water, the surface-modified silica composition and water molecules easily form hydrogen bonds. In this state, even if the silica composition and the base material resin are mixed, the hydrogen bond between the silanol group (—Si—OH) and the functional group of the base material resin is inhibited by the hydrogen bond with the water molecule. The obtained composite resin composition cannot sufficiently exhibit the physical properties originally required such as strength. Based on such a phenomenon, when the method of removing the water adhering to the silanol group (-Si-OH) was earnestly studied, the water molecule vibrates by receiving the energy of the sound wave and the hydrogen bond with the silanol group is generated. Cleavage exposes the silanol group, which allows the silanol group to efficiently hydrogen bond with the functional group of the resin monomer.Therefore, the composite resin composition obtained by polymerizing the resin monomer in such a state has an inherent strength and the like. It was found that the physical properties it possessed could be fully exerted. In addition, since the absolute amount of unbound water is small and the system is a hydrophobic system of organic solvent,
It is extremely unlikely that the dissociated water will recombine with the silanol group, and therefore the physical properties associated therewith are unlikely to deteriorate.
Further, it is considered that these dissociated waters are dissipated into the atmosphere by enclosing an inert gas such as nitrogen during the production of the composite resin material. As described above, according to the method of the present invention, it is possible to form a hydrogen bond between the silanol group and the resin monomer to obtain a composite resin material having stronger physical properties,
Unlike clay-like inorganic fillers such as montmorillonite, the formed composite resin material has the advantage that it is not colored.

In the present invention, the frequency of the sound wave when the mixed solution of the resin monomer, the surface-modified silica composition and the solvent is sonicated is 10 to 10,000 KHz.
This efficiently cleaves hydrogen bonds between silanol groups and water molecules remaining in the surface-modified silica composition, and promotes the formation of hydrogen bonds between silanol groups and functional groups such as carbonyl groups of resin monomers. As a result, the physical properties originally possessed by the composite resin composition, such as strength, can be sufficiently exhibited. Preferably, the frequency of the sound wave is 10 to 500 KHz. At this time, at a frequency lower than 10 KHz or higher than 10,000 KHz, the energy is insufficient, and the force for breaking the hydrogen bond formed between the silanol group and the water molecule is weak, and therefore the silanol group and the functional group of the resin monomer are weak. In some cases, hydrogen bonds with and cannot be efficiently formed, and thus the strength of the obtained nanocomposite resin composition may not be sufficiently improved.

Further, in the present invention, in order to prevent the redeposition of water molecules to the silanol groups, the sonication of the mixed solution is carried out in the mixed solution in which the resin monomer and the silica composition coexist.

In the present invention, the sonication conditions of the mixed solution differ depending on the type and amount of the resin monomer, the surface-modified silica composition and the solvent, and the silanol groups and water molecules remaining in the surface-modified silica composition are mixed. There is no particular limitation as long as the hydrogen bond can be efficiently broken. For example, the sonication temperature of the mixed solution is usually 20 to 120 ° C, preferably 40 to 100 ° C, and the treatment time is usually 5 to 120 ° C.
Minutes, preferably 10 to 40 minutes. Further, the sonication is performed under normal pressure.

Further, the method of the present invention includes a step of polymerizing the resin monomer after the sonication. At this time, in order to accelerate the polymerization of the resin monomer, the mixed solution preferably further contains a polymerization initiator. At this time, azobisisobutyronitrile (A
IBN), benzoyl peroxide and the like. The amount of the polymerization initiator used is not particularly limited as long as the polymerization of the resin monomer can proceed well, and a known amount can be used. For example, the amount of the polymerization initiator used is 0.05 to 1 mass% with respect to the resin monomer.

In the present invention, the polymerization reaction of the resin monomer may be any of suspension polymerization, solution polymerization, emulsion polymerization and bulk polymerization. Further, the polymerization conditions differ depending on the types and amounts of the resin monomer, the surface-modified silica composition and the solvent, and are not particularly limited as long as the resin monomer can be efficiently polymerized. For example, the polymerization temperature of the resin monomer is usually 20 to 120 ° C, preferably 40 to 100 ° C.
And the polymerization time is usually 4 to 48 hours, preferably 6 to 24 hours. Further, the polymerization reaction is carried out under normal pressure.

According to the present invention, after the polymerization reaction of the above resin monomer, the solvent is removed to obtain a resin composition, but the method of removing the solvent that can be used at this time is not particularly limited.
A known method can be appropriately used depending on the kind of the solvent. For example, there are a method of precipitating (coagulating) the target substance using an incompatible solvent, a method of heating and evaporating with a distillation apparatus and the like. Solvents for coagulation in the method of precipitating (coagulating) a target substance using an incompatible solvent include alcohols such as ethanol, methanol, butanol, and hexane, and the compounding amount thereof is after the polymerization reaction. 10 to 300 parts by mass, and more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the solution.

In the present invention, the resin monomer constituting the mixed solution is appropriately selected according to the desired application and is not particularly limited, but an oxygen atom (which easily forms a hydrogen bond with a silanol group contained in silica ( O), a nitrogen atom (N), a fluorine atom (F), etc. The resin monomer which has a functional group containing atoms with high electronegativity is preferable. Further, depending on the application, it is preferably a transparent resin monomer. In addition, the transparent resin monomer in this specification refers to a monomer that constitutes a resin having a total light transmittance of 75% or more. Specifically, a (meth) acrylic polymer material such as polymethylmethacrylate, a polyarylate polymer material such as a polycarbonate polymer material, a polyacetal polymer material, a thermoplastic polyester polymer such as polyethylene terephthalate. Monomers of resins having functional groups containing oxygen atoms such as materials, polyetheretherketone-based polymer materials, monomers constituting polyetherketone-based polymer materials; polyamide-based polymer materials, polyamide-imide-based polymer materials, etc. Resin monomer having a functional group containing a nitrogen atom such as a monomer forming a monomer; Resin monomer having a functional group containing a fluorine atom such as a monomer forming a fluororesin such as polytetrafluoroethylene; polystyrene polymer material Is mentioned. Of these, a transparent material suitable for use in which interaction between the silanol group contained in the surface-modified silica composition and the functional group contained in the monomer constituting the matrix resin or high transparency is required as an alternative to the inorganic glass. Considering that it is a resin material, a (meth) acrylic polymer material containing methyl methacrylate having a carbonyl group (—C═O) and a monomer that constitutes a polycarbonate polymer material are preferable. In particular, in the case of a member that is frequently used outdoors such as automobile window glass, it is preferable to use a monomer that constitutes a (meth) acrylic polymer material having good weather resistance in addition to transparency. In addition, each of the monomers constituting the (meth) acrylic polymer material, the polycarbonate polymer material and the polystyrene polymer material is (meth)
Some have acrylic monomers, divalent phenyl monomers, styrene monomers, etc. as main components, especially methacrylic monomers, (meth) acrylic monomers, diphenyl carbonate and bisphenol. It is preferred that A is the major component.

Further, the surface-modified silica composition constituting the mixed solution in the present invention is 0.44 to 8, preferably 1
It has a modification factor of ˜4. This is because the affinity of the silanol group of the fine particle silica with the base resin is improved by subjecting the silanol group of the fine particle silica to a hydrophobic treatment with an alkyl group. In particular, when the modification coefficient is in this range, the affinity with the base material resin increases, so the silica component is uniformly dispersed in the base material resin, and the high strength and low coefficient of thermal expansion do not deteriorate transparency. Transparent resin is obtained. Further, the remaining silanol groups generate a hydrogen bond with a functional group contained in the base material resin, for example, when the base material resin is polymethylmethacrylate or the like, a carbonyl group (—C═O) contained in the skeleton thereof. Therefore, the transparent resin composition is stronger and stronger.

In the present specification, the "modification coefficient" is represented by the product (A × B) of the hydrophobization ratio (A) of the silanol group of the fine particle silica and the total carbon number (B) of the alkyl group. Means a coefficient that is That is, "the surface-modified silica composition has a modification coefficient of 0.44 to 8" means that the surface-modified silica composition has a total silanol group hydrophobicity (A) and alkyl groups of fine particle silica. Product with carbon number (B) (A x B)
Means a silica composition whose surface has been modified so that the modification coefficient thereof is 0.44 to 8. Here, the hydrophobization ratio (A) of the silanol group is the ratio of the hydrogen atom contained in the silanol group of the fine particle silica to the alkyl group,
Corresponds to the hydrophobization rate of the system, exceeding 0 and 1 or less, preferably 0.
It is a number less than 0.5. The total carbon number (B) of the alkyl group is the total number of carbon atoms of the alkyl group added by directly substituting the hydrogen atom of the silanol group.

For example, when the structure of fine particle silica is schematically shown in the left formula below and modified with dimethyldichlorosilane to obtain a modified silica composition shown in the right formula below, the hydrophobicity of silanol is The conversion ratio (A) is 2 / out of the 4 silanol groups, so the conversion ratio (A) is 2 /
4 = 0.5, and since four methyl groups are added, the total number of carbon atoms (B) of the alkyl group is 4, and A × B = 2.

[0032]

[Chemical 2]

In order to produce such a surface-modified silica composition, there is a method of treating fine particle silica having a silanol group with various silicone compounds such as silane type, silazane type and siloxane type.

That is, as a method of modifying the fine particle silica with a silicone compound, a powder of the fine particle silica is dispersed in a solvent such as cyclohexane, and then a silicone compound as a modifier is added and refluxed. The so-called liquid phase method can be used. After completion of the reaction, the product is washed with cyclohexane. At this time, as a solvent for dispersing the fine particle silica, a paraffinic hydrocarbon such as pentane, hexane, heptane and octane; a cycloparaffinic hydrocarbon such as cyclobutane, cyclopentane and cyclohexane; a ketone based carbonization such as methyl ethyl ketone and acetone Hydrogen; aromatic hydrocarbons such as toluene, xylene, benzene and the like can be mentioned. The fine particle silica is dispersed in the solvent at a concentration of 10 to 45% by mass. The modification coefficient can be adjusted by the kind and concentration of the modifier, the reflux time, and the like. Further, the modification conditions are not particularly limited as long as the desired modification coefficient can be achieved, and vary depending on the type and concentration of the silicone compound. For example, the preferable reforming temperature is 40 to 200 ° C., and the reflux time is 0.5 hours or more. When reforming with a chlorine-based silicone compound, a catalyst may be used in the reforming reaction in order to capture the generated hydrogen chloride. As such a catalyst, there is pyridine, and the addition amount thereof is 0 to 300 with respect to 100 parts by mass of the chlorine-based modifier.
Parts by mass.

Such modification is carried out by heating fine silica powder in a vacuum line to remove adsorbed water, and then introducing the vapor of the above-mentioned silicone compound as a modifying agent.
It can also be carried out by a so-called vapor phase method of heating at ~ 300 ° C. The modification coefficient can be adjusted by the kind and concentration of the modifier, the reflux time, and the like. When the fine particle silica before modification is in a colloidal form dispersed in water, it is necessary to replace the water with an organic solvent such as methyl ethyl ketone in order to avoid reactivity with water. Such a dehydration method is disclosed in JP-A-2000-44226.
No., etc.

As fine particle silica, silanol groups (-
Any inorganic silica having (Si—OH) can be used without particular limitation. The terminal hydrogen atom of the silanol group has an active protic property, reacts well with an alkali component, and contains a nitrogen atom, a fluorine atom, and an atom having a high electronegativity such as an oxygen atom contained in a carbonyl group. It has a property of forming a hydrogen bond with a functional group. For this reason, when the surface-modified silica composition is mixed with the resin monomer that serves as the base material resin, it is firmly mixed into the resin monomer. As the fine particle silica, generally commercially available high temperature decomposition products of silicon tetrachloride (SiCl ₄ ) and sodium silicate ((Si
A material obtained by hydrolysis of O ₂ ) _n · Na ₂ O) can be used as a raw material. The former is sold in the form of fine powder and the latter is sold in the form of water-dispersed or organic solvent-dispersed colloid. In the present invention, both fine particle silicas can be used as raw materials for the surface-modified silica composition. In addition, in the latter colloidal silica, spherical silica is 4-5 in recent years.
Individually connected chain silica having a length of 40 to 50 nm is sold (for example, Snowtec S manufactured by Nissan Chemical Industries, Ltd.).
In the present invention, such chain silica can also be used as a raw material of a silica composition in the same manner as conventional spherical silica. The shape of the fine particle silica is not particularly limited and may be spherical or chain-like as described above, but the average primary particle diameter is preferably 380 nm or less, more preferably Is 5
It is preferably 100 nm. This is because when this is mixed with a resin monomer, it is possible to improve the elastic modulus and reduce the thermal expansion coefficient of the resin member while maintaining transparency.

As the modifier for modifying the surface of the fine particle silica, the silicone compounds shown below are particularly preferable.

[0038]

[Chemical 3]

In the above formula, R ₁ , R ₂ and R ₃ have 1 carbon atoms.
The alkyl group which may have a branch of 20 is shown. At this time, R ₁ , R ₂ and R ₃ may be the same or different. Here, as the alkyl group having 1 to 20 carbon atoms, a methyl group, an ethyl group, a propyl group,
Examples thereof include isopropyl group, butyl group, isobutyl group, sec-butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group and octadecyl group. In the present invention, hydrophobicity can be imparted by adding the alkyl group contained in the silicone compound to the fine particle silica. In addition, X ₁ , X ₂ and X ₃ are
A chlorine atom, a hydrogen atom, and an alkoxy group having 1 to 8 carbon atoms are shown. At this time, X ₁ , X ₂ and X ₃ may be the same or different. Where the carbon number is 1 to 8
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group,
Examples thereof include a pentyloxy group, a hexyloxy group, a 2-ethylhexyloxy group and an octyloxy group. In the present invention, since X ₁ , X ₂ and X ₃ easily react with the silanol group in the fine particle silica, the modification coefficient can be easily adjusted, and modification according to the purpose can be carried out rapidly with good reproducibility. Because you can.

More specifically, among the silicone compounds for modifying fine particle silica, n-butyltrichlorosilane and n-butyltrichlorosilane are used as the monosubstituted alkyl silicone compounds.
Butyltrimethoxysilane, n-decyltrichlorosilane, n-decyltriethoxysilane, dimethoxymethylchlorosilane, n-dodecyltrichlorosilane, n-dodecyltriethoxysilane, ethyltrichlorosilane,
Ethyltriethoxysilane, ethyltrimethoxysilane, n-heptyltrichlorosilane, n-hexadecyltrichlorosilane, n-hexadecyltrimethoxysilane, n-hexyltrichlorosilane, n-hexyltriethoxysilane, n-hexyltrimethoxysilane , Methyltrichlorosilane, methyltriethoxysilane, n
-Octadecyltrichlorosilane, n-octadecyltriethoxysilane, n-octadecyltrimethoxysilane, n-propyltrichlorosilane, n-propyltriethoxysilane, n-propyltrimethoxysilane and the like.

The disubstituted alkyl silicone compounds include n-butylmethyldichlorosilane, n-decylmethyldichlorosilane, di-n-butyldichlorosilane, diethyldichlorosilane, diethyldiethoxysilane and di-n-. Hexyldichlorosilane, dimethyldichlorosilane, dimethyldiethoxysilane, dimethyldimethoxysilane, dimethyldipropoxysilane, dimethylmethoxychlorosilane, di-n-octyldichlorosilane, docosylmethyldichlorosilane, dodecylmethyldichlorosilane, dodecylmethyldiethoxysilane , Ethylmethyldichlorosilane, n-heptylmethyldichlorosilane, n-hexylmethyldichlorosilane, methylpentyldichlorosilane, n-octadecylmethoxydichlorosilane, n- Kuta decyl methyl dichlorosilane,
Examples include propylmethyldichlorosilane and the like.

The trisubstituted alkyl silicone compounds include n-decyldimethylchlorosilane, ethyldimethylchlorosilane, n-octadecyldimethylchlorosilane, n-octadecyldimethylmethoxysilane,
Examples thereof include n-octyldimethylchlorosilane, n-propyldimethylchlorosilane, trimethylchlorosilane, trimethylethoxysilane, trimethylmethoxysilane, trimethyl-n-propoxysilane, and tri-n-propylchlorosilane.

In such a silicone-based compound, since the alkyl group contained therein is hydrophobic, the surface-modified silica composition modified by this is excellent in compatibility with the resin monomer, and particularly the (meth) acrylic-based compound. Polymer materials, polyarylate polymer materials such as polycarbonate polymer materials, polyethylene terephthalate polymer materials, polyacetal polymer materials, polyetheretherketone polymer materials, polyetherketone polymer materials, polyamide It is possible to improve the affinity with a polymer-based polymer material, a polyamide-imide-based polymer material, and a monomer that constitutes a fluororesin. Due to such improvement in affinity, silica can be uniformly dispersed in the resin monomer.

The shape of the surface-modified silica composition according to the present invention which has been modified as described above is not particularly limited, and not only general particles and substantially spherical shapes, but also chain shapes, rectangular parallelepipeds and plate shapes, A linear shape such as a fiber or a branched shape may be used, but a particle shape or a chain shape is preferable. Further, the particle diameter of the surface-modified silica composition according to the present invention is also not particularly limited as long as the particle diameter of the surface-modified silica composition can be uniformly dispersed in the resin monomer,
Considering obtaining a nanocomposite transparent resin composition having high strength, low thermal expansion coefficient and high transparency, it is desirable to use a nanocomposite transparent resin composition having a particle size as small as possible. More preferably, a surface-modified silica composition having an average primary particle diameter of 380 nm or less, which is a visible light wavelength (380 to 770 nm), and particularly preferably 5 to 100 nm can be used. By setting the average primary particle diameter to 380 nm or less, the transparency of the resin composition containing this can be ensured. In addition, those having an average primary particle size of 5 to 100 nm are excellent in terms of ensuring transparency.
In addition, in this specification, "average primary particle diameter" means the average value of the lengths of the longest linear distances of the silica composition.

In the present invention, the compounding amount of the surface-modified silica composition is 3 to 1 with respect to 100 parts by mass of the resin monomer.
It is in the range of 00 parts by mass. This is because the strength such as rigidity and impact resistance can be secured and the coefficient of thermal expansion can be reduced by limiting the blending amount of the silica composition to a specific range. As the blending amount of the silica composition increases, the formation of hydrogen bonds between the silanol groups of the silica composition and the functional groups of the resin monomer is promoted, and the strength of the composite resin material increases and the coefficient of thermal expansion decreases accordingly. Even if the blending amount is more than 100 parts by mass with respect to 100 parts by mass of the resin monomer, there is little further improvement in characteristics, conversely the transparency is lowered, and the specific gravity is increased, which may increase the mass of the member. Therefore, it is desirable that the upper limit of the amount of the surface-modified silica composition be 100 parts by mass with respect to 100 parts by mass of the resin monomer. On the other hand, if the compounding amount is 3 parts by mass or more based on 100 parts by mass of the resin monomer, the effect of reducing the linear expansion coefficient is low, but the strength of the composite resin material is improved and the effect is recognized, but the compounding amount is 3
When it is less than the mass part, the effect of reducing the coefficient of thermal expansion is low, and the function of improving the strength and reducing the coefficient of thermal expansion of the nanocomposite resin composition is poor,
This is because there may be no difference from the transparent resin material containing no silica. The strength of the nanocomposite transparent resin composition is recognized to be 3 parts by mass or more of the silica composition, and when it is 40 parts by mass or less, all the predetermined functions can be secured and the weight increase is minimized. You can hold it to the limit.
From these, the blending amount of the surface-modified silica composition is more preferably 3 to 40 parts by mass with respect to 100 parts by mass of the resin monomer.

In the present invention, the surface-modified silica composition may be directly mixed with the resin monomer or solvent, or may be previously dissolved in another solvent and then mixed in the form of a solution. In the latter case, other solvents that can be used include
Paraffin hydrocarbons such as pentane, hexane, heptane and octane; cycloparaffin hydrocarbons such as cyclobutane, cyclopentane and cyclohexane; aromatic hydrocarbons such as methyl ethyl ketone, toluene, xylene, acetone and benzene. To be The concentration of the silica composition in the solution at this time is not particularly limited, but is preferably 10 to 45 mass% from the viewpoint of uniformity of mixing and operability.

In the present invention, the solvent constituting the mixed solution is appropriately selected depending on the kind of the resin monomer and the surface-modified silica composition used. For example, when using methyl methacrylate or the like as the main resin monomer, aromatic or ketone organic solvents such as acetone, aniline, xylene, ethyl acetate, methyl acetate, butyl acetate, toluene and methyl ethyl ketone are preferably used. can do. The amount of the solvent is not particularly limited, but the concentration of the resin monomer (or surface-modified silica composition) in the solvent is 10 to 40% by mass from the viewpoint of uniformity of the mixed solution and operability of sonication and polymerization reaction. The amount is preferably such that In the present invention, the solvent is removed after the polymerization reaction of the resin monomer, whereby the nanocomposite transparent resin composition of the present invention can be prepared. Examples of the solvent for coagulation include alcohols such as ethanol, methanol, butanol, hexane, etc., and the compounding amount is 1 part with respect to 100 parts by mass of the solution after the polymerization reaction.
The amount is 0 to 300 parts by mass, more preferably 50 to 100 parts by mass.

In the nanocomposite resin composition of the present invention, various additives such as an antistatic agent, an antioxidant, a heat stabilizer, an ultraviolet absorber, and the like may be added, if necessary, so long as the transparency is not impaired.
Antioxidants, energy quenchers, flame retardants, pigments, colorants and the like may be added.

The nanocomposite resin composition of the present invention has the characteristics of high strength, low coefficient of thermal expansion, and high transparency depending on the type of resin monomer. Suitable for transparent materials and fixtures used in automobiles, home appliances and houses such as transparent covers for instrument panels for interior materials and window glasses (windows), headlamps, sunroofs and combination lamp covers for exterior materials. ing. In particular,
INDUSTRIAL APPLICABILITY The nanocomposite resin composition of the present invention can exert its effect in a resin window or a molded article for interior / exterior parts of automobiles, which is used as a substitute for inorganic glass, which requires weight reduction and flexibility in molding.

An example of the use of the nanocomposite resin composition of the present invention will be described below with reference to FIG. Figure 1
[Fig. 2] is an external view of a sedan-based automobile, and is an explanatory diagram showing an example of a resin window application of the nanocomposite resin composition according to the present invention. The nanocomposite resin composition of the present invention can be applied to a vehicle front window 1, side window 2, rear window 3, etc. as shown in FIG. In such a case, the window is installed on the front, rear, and side doors of the vehicle as a component for preventing wind and rain, as shown in FIG. 1, but its use area is as large as 3 to 4 m ² .
In the case of the conventional inorganic glass, the weight is 30 to 35.
Since it weighs as much as kg, it was a part with great expectations for weight reduction.

As described above, the nanocomposite resin composition of the present invention has excellent transparency and rigidity, and has little warpage even at high temperatures, and therefore there are problems to be solved in terms of safety and function. It can also be applied to windows that have not yet been adopted in earnest, which makes it possible to reduce the weight of vehicles and increase the degree of freedom in design, which have been highly demanded in the past. Further, in recent years, the spread of one-box type RV vehicles has been remarkable, and the proportion of windows has increased,
From the viewpoint of weight reduction and improvement of occupant's visibility and comfort, the demand for resinification of windows has become stronger and stronger, but the transparent resin glass molded by the nanocomposite transparent resin composition of the present invention is used for these automobile windows. It has the functions required for the vehicle and contributes to the weight reduction and comfort of the vehicle. In addition to the resin windows described above, appearance quality such as aesthetics, smoothness, and transparency is required, and applications requiring high rigidity and scratch resistance of the surface, for example, exterior materials for buildings, interior materials, railway vehicles It can also be used for interior materials.

In the present invention, as a method of manufacturing various members such as the above-mentioned vehicle parts and interior materials for buildings including resin windows, injection molding, vacuum pressure molding, etc. are appropriately selected according to the parts. Just select it. General glass fiber reinforced resin, the physical properties of the glass fiber gradually decreases due to repeated breaking of the glass fiber due to repeated shear stress and the recyclability is low, but the nanocomposite transparent resin composition of the present invention has a surface layer as described above. Since the silica composition modified to have a phenyl group is used, it is difficult to receive shear stress and it is possible to suppress deterioration of physical properties.

In addition, the nanocomposite transparent resin composition of the present invention is used to shape by a known resin molding method such as a vacuum molding method, a vacuum pressure air method, a heat compression method, a blow molding method, a resin window, or an automobile. Exterior parts such as outer plates or interior parts for automobiles can also be molded.

[0054]

EXAMPLES The present invention will be specifically described below with reference to examples. The present invention is not limited to this. Incidentally, various evaluations in Examples and Comparative Examples by the following methods, unless otherwise specified, "parts" means parts by mass,
"%" Indicates mass%.

(Evaluation Method of Nanocomposite Resin Composition) (1) The total light transmittance was measured with a haze meter (HM-65 manufactured by Murakami Color Research Laboratory). 75% or more was passed.

(2) The dispersion state of silica was observed with a transmission electron microscope (H-800 manufactured by Hitachi, Ltd.).

(3) Bending strength and elastic modulus were measured with an autograph (DCS-10T manufactured by Shimadzu Corporation).
A bending strength of 108 MPa or more was passed.

(4) The coefficient of linear expansion was measured with a thermomechanical measuring device (TMA120C manufactured by Seiko Instruments Inc.).

Example 1 In a three-necked flask, fine particle silica having an average primary particle size of 20 nm (Aerosil # 90G manufactured by Nippon Aerosil Co., Ltd.) 2
g and 400 g of cyclohexane were added to prepare a silica solution having a concentration of fine particle silica of 0.5% by mass. Next, n-octadecyltrichlorosilane (CH) which is a monosubstituted alkyl silicone compound is added to the silica solution.
₃ (CH ₂ ) ₁₇ SiCl ₃ ) 0.3 g and pyridine 0.3 ml as a catalyst were added, the liquid temperature was set to 80 ° C., and 2,
Refluxing treatment was performed under four conditions of 4, 6, and 8 hours. After completion of the reaction, wash with cyclohexane and dry to obtain modification coefficient (hydrophobicity ratio x
Total carbon number) is 2.01 (referred to as A-1), 4.45
Four types of surface-modified silica compositions (designated as A-2), 6.16 (designated as A-3) and 8.00 (designated as A-4) were obtained. The hydrophobicity of fine particle silica was measured by FT-IR. The results are shown in Table 1.

Example 2 In a flask, 50 parts of toluene as an organic solvent, 20 parts of methyl methacrylate (MMA) as a resin monomer, 0.05 parts of AIBN (azobisisobutyronitrile) as a reaction initiator, and Example 1 were obtained. The obtained modification coefficient is 2.
2 parts of the surface-modified silica composition of A-1 of No. 01 was added and stirred with a stir bar to prepare a mixed solution. This mixed solution was a slightly milky cloudy solution.

Next, this mixed solution was mixed with an sonic oscillator in an amount of 3
A 0 KHz sound wave was irradiated at 80 ° C. for 30 minutes to obtain a homogeneous mixed dispersion solution. The milky white haze disappeared from the solution after the sonication, and the solution became transparent with no turbidity. This is because, in addition to making the silica composition finer and more dispersed by sonication, it is between the carbonyl group (-C = O) of methyl methacrylate (MMA) and the silanol group (-Si-OH) of the silica composition. It is considered that this is because the generation of hydrogen bond of was promoted.

Further, the air in the flask was replaced with nitrogen gas to seal the inside of the system, and the mixed dispersion solution obtained above was added to 8
The MMA was polymerized by treatment at a temperature of 0 ° C. for 24 hours. After completion of the reaction, hexane was added dropwise to cause precipitation to obtain a nanocomposite resin composition (1) according to the present invention.

The nanocomposite resin composition (1) thus obtained is dried to give granules, which are then extruded to a thickness of 2
It was formed into a sheet of mm. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 1.

Example 3 Instead of the surface-modified silica composition of A-1, A-2 (modification coefficient: 4.45) and A-3 (modification coefficient: 6.5) obtained in Example 1 were used. 16) or A-4 (modification coefficient: 8.00)
Polymerization treatment was carried out by the same method and conditions as in Example 2 except that the three kinds of surface-modified silica compositions of 3 above were used instead of the above four kinds of nanocomposite resin compositions (2) according to the present invention.
~ (4) was obtained.

Each of the nanocomposite resin compositions (2) to (4) thus obtained was dried into granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 1.

Comparative Example 1 Polymerization treatment was carried out in the same manner as in Example 1 except that the reflux treatment time was changed to 10 hours, and the modification coefficient (hydrophobization rate × total carbon number) was changed. A surface-modified silica composition (a-0) for comparison having a value of 8.12 was obtained.

Then, in Example 2, the comparative surface-modified silica composition (a-0) thus obtained is used in place of the surface-modified silica composition A-1. Polymerization treatment was performed under the same method and conditions as in Example 2 except for the above, to obtain a nanocomposite resin composition (1) for comparison.

The comparative nanocomposite resin composition (1) thus obtained was dried to give granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 1.

Comparative Example 2 Polymerization was carried out under the same method and conditions as in Example 1 to obtain four types of comparative surface-modified silica compositions (a-1) to (a-4).

Next, in Example 2, comparative surface-modified silica compositions (a-1) to (a) thus obtained were obtained.
-4) was used instead of the surface-modified silica composition of A-1 and the sonication step was not performed, and the polymerization treatment was performed by the same method and conditions as in Example 2, Four types of comparative nanocomposite resin compositions (2) to (5) were obtained.

Each of the nanocomposite resin compositions for comparison (2) to (5) thus obtained was dried to form granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 1.

Comparative Example 3 A comparative surface-modified silica composition (a-5) was prepared by carrying out a polymerization treatment in the same manner and conditions as in Comparative Example 1 except that the sonication step was not carried out. Got

Next, in Example 2, the comparative surface-modified silica composition (a-5) thus obtained was treated with A
Polymerization treatment was carried out by the same method and conditions as in Example 2 except that the surface-modified silica composition of No. 1 was used instead of the surface-modified silica composition to obtain a comparative nanocomposite resin composition (6).

The comparative nanocomposite resin composition (6) thus obtained was dried to give granules, which were molded into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 1.

Comparative Example 4 A granular polymethylmethacrylate resin (Acrypet VH manufactured by Mitsubishi Rayon Co., Ltd.) having a thickness of 2 mm was prepared by an extrusion method.
Was formed into a sheet. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 1. It was found that this sheet had appropriate physical properties and high transparency. In addition, this result,
For comparison, the results are shown in Tables 2 to 4 below.

[0076]

[Table 1]

Example 4 Using the same fine particle silica and cyclohexane as in Example 1, a silica solution was prepared in the same manner as in Example 1. Next, di-n-butyldichlorosilane (CH) which is a disubstituted alkyl silicone compound is added to the silica solution.
0.1 g of ₃ (CH ₂ ) ₃ SiCH ₃ (CH ₂ ) ₃ Cl ₂ ),
0.3 ml of pyridine was added as a catalyst, and the liquid temperature was 80 ° C.
Was refluxed under 5 conditions of 2, 4, 6, 8 and 10 hours. After completion of the reaction, the product was washed with cyclohexane and dried, and the modification coefficient (hydrophobicity ratio × total carbon number) was 1.07 (referred to as B-1), 2.14 (referred to as B-2), and 3.05 ( B-
3.), 3.61 (designated as B-4) and 3.
61 (referred to as B-5) five kinds of surface-modified silica compositions were obtained. The hydrophobicity of fine particle silica was measured by FT-IR. The results are shown in Table 2.

Example 5 In a flask, 50 parts of toluene as an organic solvent, 20 parts of methyl methacrylate (MMA) as a resin monomer, 0.05 parts of AIBN (azobisisobutyronitrile) as a reaction initiator, and Example 4 were obtained. B-1 to B-5
2 parts of each of the 5 kinds of surface-modified silica compositions of 5 above were added and stirred with a stir bar to obtain a mixed solution of 5 kinds. All were slightly milky and cloudy solutions.

Next, each of these five types of mixed solutions was irradiated with a sound wave of 30 KHz from an sonic oscillator at 80 ° C. for 30 minutes to obtain a homogeneous mixed dispersion solution. The milky white haze disappeared from all of the 5 kinds of solutions after the sonication, and all the solutions were in a transparent state without turbidity. This is similar to the case in Example 2 in that, in addition to making the silica composition finer and more dispersed by sonication, the carbonyl group (-C = O) of methyl methacrylate (MMA) and the silanol group of the silica composition ( It is considered that the generation of hydrogen bond with (Si—OH) was promoted.

Further, the air in the flask was replaced with nitrogen gas to seal the inside of the system, and the 5 kinds of mixed dispersion solutions obtained above were each treated at a temperature of 80 ° C. for 24 hours to give M
The MA was polymerized. After the completion of the reaction, hexane is added dropwise to cause precipitation, and the nanocomposite resin composition (5)-
(9) was obtained.

Each of the nanocomposite resin compositions (5) to (9) thus obtained was dried to form granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 2.

Comparative Example 5 Polymerization treatment was carried out in the same manner as in Example 4 to obtain 5 types of comparative surface-modified silica compositions (b-1) to (b-5).

Next, in Example 5, comparative surface-modified silica compositions (b-1) to (b) thus obtained were obtained.
-5) was used instead of the surface-modified silica composition of B-1 and the sonication step was not performed, and the polymerization treatment was performed by the same method and conditions as in Example 5, Five kinds of comparative nanocomposite resin compositions (7) to (11)
Got

Each of the nanocomposite resin compositions for comparison (7) to (11) thus obtained was dried to give granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 2.

[0085]

[Table 2]

Example 6 Using the same fine particle silica and cyclohexane as in Example 1, a silica solution was prepared in the same manner as in Example 1. Next, trimethylchlorosilane ((CH ₃ ) ₃ Si, which is a 3-substituted alkyl silicone compound, is added to the silica solution.
Cl) (0.1 g) and pyridine (0.3 ml) as a catalyst were added, and the mixture was refluxed under the five conditions of liquid temperature of 80 ° C. for 4, 6, 8 and 10 hours. After completion of the reaction, the product is washed with cyclohexane and dried, and the modification coefficient (hydrophobicity ratio x total carbon number) is 0.4.
5 (referred to as C-1), 0.95 (referred to as C-2),
Four surface modified silica compositions of 1.35 (designated C-3) and 1.34 (designated C-4) were obtained. In addition,
The hydrophobicity of fine particle silica was measured by FT-IR.
The results are shown in Table 3.

Example 7 In a flask, 50 parts of toluene as an organic solvent, 20 parts of methyl methacrylate (MMA) as a resin monomer, 0.05 parts of AIBN (azobisisobutyronitrile) as a reaction initiator, and Example 6 were obtained. C-1 to C-4
2 parts of each of the four types of surface-modified silica compositions described above were added and stirred with a stir bar to obtain a mixed solution of four types. All were slightly milky and cloudy solutions.

Next, each of these four kinds of mixed solutions was irradiated with a sound wave of 30 KHz from an sonic oscillator at 80 ° C. for 30 minutes to obtain a homogeneous mixed dispersion solution. The milky white haze disappeared from each of the four kinds of solutions after the sonication, and all the solutions were in a transparent state without turbidity. This is similar to the case in Example 2 in that, in addition to making the silica composition finer and more dispersed by sonication, the carbonyl group (-C = O) of methyl methacrylate (MMA) and the silanol group of the silica composition ( It is considered that the generation of hydrogen bond with (Si—OH) was promoted.

Further, the air in the flask was replaced with nitrogen gas to seal the inside of the system, and the four kinds of mixed dispersion solutions obtained above were treated at a temperature of 80 ° C. for 24 hours to give M
The MA was polymerized. After completion of the reaction, hexane is added dropwise to cause precipitation, and the nanocomposite resin composition (10)
(13) was obtained.

Each of the nanocomposite resin compositions (10) to (13) thus obtained was dried to form granules,
This was formed into a sheet having a thickness of 2 mm by the extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 3.

Comparative Example 6 Polymerization was carried out in the same manner as in Example 6 except that the reflux treatment time was changed to 2 hours, and the modification coefficient (hydrophobization rate × total carbon number) was changed. A comparative surface-modified silica composition (c-0) having a ratio of 0.40 was obtained.

Next, in Example 7, each of the comparative surface-modified silica compositions (c-0) thus obtained is used in place of the C-1 surface-modified silica composition. Polymerization was performed under the same method and conditions as in Example 7 except for the above, to obtain a nanocomposite resin composition (12) for comparison.

The comparative nanocomposite resin composition (12) thus obtained was dried to give granules, which were molded into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 3.

Comparative Example 7 Polymerization was carried out in the same manner as in Example 6 except that the reflux treatment time was changed to 2 hours, and the modification coefficient (hydrophobization rate × total carbon number) was changed. A comparative surface-modified silica composition (c-1) having a ratio of 0.40 was obtained.

Next, in Example 7, each of the comparative surface-modified silica compositions (c-1) thus obtained was used in place of the C-1 surface-modified silica composition. Then, a polymerization treatment was performed under the same method and conditions as in Example 7 except that the sonication process was not performed, to obtain a nanocomposite resin composition for comparison (13).

The comparative nanocomposite resin composition (13) thus obtained was dried into granules, which were molded into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 3.

Comparative Example 8 Four types of comparative surface-modified silica compositions (c-2) to (c-5) were obtained by polymerizing under the same method and conditions as in Example 6.

Next, in Example 7, comparative surface-modified silica compositions (c-2) to (c) thus obtained.
-5) was used instead of the C-1 surface-modified silica composition, respectively, and a polymerization treatment was carried out in the same manner as in Example 7 except that the sonication step was not performed, Four types of comparative nanocomposite resin compositions (14) to (1
7) was obtained.

Each of the comparative nanocomposite resin compositions (14) to (17) thus obtained was dried into granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 3.

[0100]

[Table 3]

Example 8 Using the same fine particle silica and cyclohexane as in Example 1, a silica solution was prepared in the same manner as in Example 1. Next, trimethylethoxysilane ((CH ₃ ) ₃ S, which is a silicone compound of 3-substituted alkyl, is added to this silica solution.
0.1 g of iOC ₂ H ₅ ) was added, and the solution was heated to 80 ° C. and refluxed under 4 conditions of 4, 6, 8 and 10 hours. After completion of the reaction, the product was washed with cyclohexane and dried to give a modification coefficient (hydrophobicization rate × total carbon number) of 0.44 (referred to as D-1),
Five types of surface-modified silica compositions of 0.78 (designated as D-2), 1.18 (designated as D-3) and 1.19 (designated as D-4) were obtained. The hydrophobicity of fine particle silica was measured by FT-IR. The results are shown in Table 4.

Example 9 In a flask, 50 parts of toluene as an organic solvent, 20 parts of methyl methacrylate (MMA) as a resin monomer, 0.05 parts of AIBN (azobisisobutyronitrile) as a reaction initiator and obtained in Example 8 were obtained. D-1 to D-4
2 parts of each of the four types of surface-modified silica compositions described above were added and stirred with a stir bar to obtain a mixed solution of four types. All were slightly milky and cloudy solutions.

Next, each of these four kinds of mixed solutions was irradiated with a sound wave of 30 KHz from an sonic oscillator at 80 ° C. for 30 minutes to obtain a homogeneous mixed dispersion solution. The milky white haze disappeared from all of the 5 kinds of solutions after the sonication, and all the solutions were in a transparent state without turbidity. This is similar to the case in Example 2 in that, in addition to making the silica composition finer and more dispersed by sonication, the carbonyl group (-C = O) of methyl methacrylate (MMA) and the silanol group of the silica composition ( It is considered that the generation of hydrogen bond with (Si—OH) was promoted.

Further, the air in the flask was replaced with nitrogen gas to seal the inside of the system, and the four kinds of mixed dispersion solutions obtained above were treated at a temperature of 80 ° C. for 24 hours to give M
The MA was polymerized. After completion of the reaction, hexane is added dropwise to cause precipitation, and the nanocomposite resin composition (14)-
(17) was obtained.

Each of the nanocomposite resin compositions (14) to (17) thus obtained was dried to give granules,
This was formed into a sheet having a thickness of 2 mm by the extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 4.

Comparative Example 9 Polymerization was carried out by the same method and conditions as in Example 8 except that the reflux treatment time was changed to 2 hours, and the modification coefficient (hydrophobization rate × total carbon number) was changed. A comparative surface-modified silica composition (d-0) having a size of 0.25 was obtained.

Next, in Example 9, the comparative surface-modified silica composition (d-0) thus obtained is used in place of the surface-modified silica composition D-1. Polymerization was performed under the same method and conditions as in Example 9 except for the above, to obtain a nanocomposite resin composition (18) for comparison.

The comparative nanocomposite resin composition (18) thus obtained was dried to give granules, which were molded into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 4.

Comparative Example 10 Polymerization was carried out by the same method and conditions as in Example 8 except that the reflux treatment time was changed to 2 hours in Example 8, and the modification coefficient (hydrophobization rate × total carbon number) was A comparative surface-modified silica composition (d-1) having a size of 0.25 was obtained.

Next, in Example 9, the comparative surface-modified silica composition (d-1) thus obtained was used in place of the surface-modified silica composition D-1. Further, a polymerization treatment was performed under the same method and conditions as in Example 9 except that the sonication step was not performed, to obtain a nanocomposite resin composition (19) for comparison.

The comparative nanocomposite resin composition (19) thus obtained was dried to give granules, which were molded into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 4.

Comparative Example 11 Four types of comparative surface-modified silica compositions (d-2) to (d-5) were obtained by polymerizing under the same method and conditions as in Example 8.

Next, in Example 9, comparative surface-modified silica compositions (d-2) to (d) thus obtained.
-5) was used instead of the surface-modified silica composition of D-1 and the sonication step was not performed, and the polymerization treatment was performed by the same method and conditions as in Example 9, Four kinds of comparative nanocomposite resin compositions (20) to (2
3) was obtained.

Each of the nanocomposite resin compositions for comparison (20) to (23) thus obtained was dried into granules, which were molded into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 4.

[0115]

[Table 4]

As shown in the results of Tables 1 to 4, when the nanocomposite resin composition was produced by the method of the present invention, the surface-modified silica composition was prepared "after material charging and before polymerization". It was confirmed that the physical properties were significantly improved by performing the sonication. As described above, the hydrogen bond between the silanol group and the water molecule remaining in the surface-modified silica composition is cleaved, and the hydrogen bond between the silanol group and the carbonyl group of the monomer of the base resin becomes stronger. It is thought to be a tame. In addition, the transparency of the obtained nanocomposite resin composition tended to be improved, but the effectiveness of sonication for the silica composition of the present invention was confirmed.

From the results shown in Tables 1 to 4, the nanocomposite resin composition was evaluated from the viewpoint of transparency.
-1 (modification coefficient: 0.44), total light transmittance is 83%
And more than 75% of the passing value, but c-0 in Table 3 (reformation coefficient: 0.40) and d-0 in Table 4 (reformation coefficient: 0.
In 25), the total light transmittance was 74% and 68%, respectively, which was below the acceptable value of 75%. This suggests that the lower limit of the modification coefficient should be 0.44, as according to the present invention. It is suggested that the “modification coefficient”, which is the product of the hydrophobization rate and the total number of carbon atoms, is preferably 0.44 or more.

Further, from the results of Tables 1 to 4, when evaluated from the viewpoint of the bending strength of the nanocomposite resin composition, the bending strength tends to decrease as the modification coefficient increases. 4 (reformation coefficient: 8.00), the bending strength was 131 MPa, which was a pass value of 108 MPa.
However, the bending strength was 106 MPa at a-0 (modification coefficient: 8.12), which was below the acceptable value. It is considered that the reason why the bending strength is lowered is that the steric hindrance of the alkyl group generated in the silica surface layer becomes large if the surface of the fine particle silica is excessively modified. This result suggests that the upper limit of the modification coefficient should be 8 as according to the present invention.

Example 10 In a flask, 250 parts of toluene as a solvent, 100 parts of methyl methacrylate (MMA) as a resin monomer, 0.25 parts of AIBN (azobisisobutyronitrile) as a reaction initiator and the product obtained in Example 1 were obtained. The modification coefficient is 2.
The surface-modified silica composition of A-1 which is 01 is 1, 3, 5, 10, 20, 40, 60, 80, 100, respectively.
120 parts were added and stirred with a stirrer to prepare a mixed solution of 10 kinds.

Next, each of these 10 kinds of mixed solutions was irradiated with a sound wave of 30 KHz from an sonic oscillator at 80 ° C. for 30 minutes to obtain a homogeneous mixed dispersion solution. Further, the air in the flask was replaced with nitrogen gas to seal the inside of the system, and the mixed dispersion solution obtained above was treated at a temperature of 80 ° C. for 24 hours to polymerize MMA. After completion of the reaction, hexane was added dropwise to cause precipitation to obtain a nanocomposite resin composition according to the present invention.

The ten kinds of nanocomposite resin compositions thus obtained were dried into granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. With respect to the obtained sheet, the total light transmittance, the dispersion state of the silica composition, the bending strength, the bending elastic modulus and the linear expansion coefficient were measured. The results are shown in Table 5.

[0122]

[Table 5]

As shown in Table 5, when the compounding amount is 1 part, the effect of improving the physical properties is small like the characteristics of the polymethylmethacrylate resin containing no silica. Further, when the compounding amount is 120 parts, the effect of improving various physical properties is not recognized, and conversely, the total light transmittance is less than the pass line of 75%, and the transparency is lowered. On the other hand, the blending amount of the silica composition is 1 to 10
In the range of 0 parts by mass, the thermal expansion coefficient of the nanocomposite resin composition can be reduced and the bending strength and the bending elastic modulus can be improved without impairing the transparency. Further, since the specific gravity of the nanocomposite resin composition increases as the blending amount of the surface-modified silica composition increases, the mass of the member is considered to increase, which is not preferable depending on the application requiring weight reduction of the resin window or the like. There are cases. Considering these points, the compounding amount of the surface-modified silica composition is set to the resin monomer 1
It is more preferable that the amount is 3 to 40 parts by mass with respect to 00 parts by mass.

Example 11 50 parts of toluene as a solvent, 20 parts of methyl methacrylate (MMA) as a resin monomer, and AIBN (azobisisobutyronitrile) as a reaction initiator were placed in a flask.
0.05 parts and the modification coefficient obtained in Example 1 is 2.01
10 parts of the surface-modified silica composition of A-1 was added to prepare a mixed solution.

Next, this mixed solution was irradiated with sound waves of 11 kinds of frequencies shown in Table 6 at 80 ° C. for 30 minutes by a sonic oscillator while stirring the solution with a stirrer to obtain 11 kinds of solutions. . Furthermore, the air in the flask was replaced with nitrogen gas to seal the inside of the system, and these 11 kinds of solutions were respectively
The MMA was polymerized by treating it at a temperature of 80 ° C. for 24 hours.
After completion of the reaction, hexane was added dropwise to cause precipitation to obtain 11 kinds of nanocomposite resin compositions according to the present invention.

The thus obtained 11 kinds of nanocomposite resin compositions were dried to form granules, which were formed into a sheet having a thickness of 2 mm by an extrusion method. The total light transmittance, bending strength, bending elastic modulus and linear expansion coefficient of the obtained sheet were measured. The results are shown in Table 6. As a comparative control, the results of a-1 of Comparative Example 1 in which sonication was not performed are shown in Table 6.
Also described in.

[0127]

[Table 6]

As shown in Table 6, in sonication with a frequency less than 10 KHz or more than 10 MHz,
The characteristics are the same as those of Comparative Example 1 in which no sound wave is applied, and there is no effect.
It is considered that this is because the energy released from the silanol groups by resonating the water molecules attached to the silanol groups of the silica composition is not sufficient. On the contrary,
When the frequency of the sound wave is 10 to 10,000 KHz, the bending strength and the bending elastic modulus are significantly improved and the linear expansion coefficient is greatly reduced as compared with Comparative Example 1 in which the sonication is not performed, but at the same time, the transparency is slightly. It is improved and the effect of sonication is recognized. Of these, especially 10-500KH
It is suggested that the frequency of the sound wave of 10 to 500 KHz is preferable because the effect of improving the bending strength and the bending elastic modulus and the effect of reducing the linear expansion coefficient are remarkably observed in the sonication with the frequency of z.

[Brief description of drawings]

FIG. 1 is an external view of a sedan-based automobile, and is an explanatory view showing an example of application of a nanocomposite transparent resin composition according to the present invention to a resin window.

[Explanation of symbols] 1 ... Front window, 2 ... Side window, 3 ... Rear window.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takashi Takei             1-1 Minami Osawa, Hachioji City, Tokyo             Tokyo Metropolitan University (72) Inventor Masao Nakajima             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Koichi Handa             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Yasuo Kai             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Shun Seino             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Tomohiro Ito             Nissan, Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan             Inside the automobile corporation (72) Inventor Shoichiro Yano             4-8-24, Kudan-minami 4-chome, Chiyoda-ku, Tokyo             Incorporated in Nihon University (72) Inventor Takashi Sawaguchi             4-8-24, Kudan-minami 4-chome, Chiyoda-ku, Tokyo             Incorporated in Nihon University F-term (reference) 4J011 PA13 PB06 PB16 PC08 QA03                       UA06 VA02 WA07

Claims (6)

[Claims] 1. A resin solution obtained by irradiating a mixed solution comprising a resin monomer, a surface-modified silica composition and a solvent with a sound wave of 10 to 10000 KHz, polymerizing the resin monomer to polymerize it, and then removing the solvent. The surface-modified silica composition comprises the resin monomer 100.
It is compounded in the range of 3 to 100 parts by mass with respect to parts by mass, and has a reforming coefficient of 0.44 to 8,
Method for producing nanocomposite resin composition. 2. The method for producing a nanocomposite resin composition according to claim 1, wherein the surface-modified silica composition is obtained by modifying fine particle silica with a silicone compound represented by the following formula. [Chemical 1] (In the formula, R ₁ , R ₂ and R ₃ each independently represent an alkyl group having 1 to 20 carbon atoms which may have a branch,
X ₁ , X ₂ , and X ₃ each independently represent a chlorine atom, a hydrogen atom, or an alkoxy group having 1 to 8 carbon atoms. ) 3. The surface-modified silica composition has an average of 1
The method for producing a nanocomposite resin composition according to claim 1 or 2, which is in the form of particles or chains having a secondary particle size of 380 nm or less. 4. The method for producing a nanocomposite resin composition according to claim 3, wherein the average primary particle size is 5 to 100 nm. 5. The method for producing a nanocomposite resin composition according to claim 1, wherein the resin monomer is a monomer that constitutes an acrylic polymer material or a polycarbonate polymer material. 6. The method for producing a nanocomposite resin composition according to claim 1, wherein the resin monomer is a monomer that constitutes a methacrylic polymer material.