JP4725072B2 - Coating material composition and painted product - Google Patents

Description

  The present invention relates to a coating material composition used for forming an antireflection coating and the like, and a coated product formed as an antireflection coating by coating this coating material composition.

  The anti-reflective coating formed on the outermost surface of the display has excellent anti-reflective performance, surface strength that prevents scratches (ie, scratch resistance), and surface water and water repellency that can easily remove dirt such as fingerprints. -Oil repellency (that is, antifouling property) and chemical resistance against various chemicals such as cleaners are required.

  When the film refractive index is not taken into consideration, a high surface strength can be obtained by using a UV-curable or EB-curable resin coating material. In general, however, a UV-curable or EB-curable resin has a refractive index. Since it is high, an antireflection ability cannot be obtained with a resin-rich film, and it is necessary to combine a low refractive index filler such as hollow silica fine particles. In order to obtain sufficient antireflection performance with a single layer, it is necessary to increase the ratio of the hollow silica fine particles. In this case, even if the coating matrix material is a UV curable resin or an EB curable resin, it is sufficient. The surface strength cannot be obtained. In addition, with recent high-definition displays (especially liquid crystal displays), it is necessary to eliminate defects caused by foreign matter such as dust in the antireflection coating as much as possible. However, UV-curable and EB-curable resins are diluted after coating. Even if the solvent evaporates, it is in a wet and wet state until UV or EB is irradiated, so that foreign matters such as dust are likely to adhere. For this reason, it is necessary to maintain the cleanliness of the coating zone as well as the entire drying zone, which requires large-scale equipment.

  In order to reduce the area of the drying zone that maintains the cleanliness, a thermosetting resin is preferable as the matrix forming material. However, since a general organic thermosetting resin has a high refractive index, the same as above. It is not possible to obtain a sufficient surface hardness. In addition, the refractive index of fluororesins typified by perfluororesins is as low as less than 1.40. However, the film strength is reduced due to the resin itself, so that a composite with an acrylic resin is required to obtain strength. As a result, the refractive index increases, and eventually it is difficult to achieve both sufficient antireflection performance and surface strength.

On the other hand, a hydrolyzate obtained by hydrolyzing a hydrolyzable organosilane represented by the chemical formula of SiX ₄ (X is a hydrolyzable group) has a lower film refractive index than a general organic resin such as an acrylic resin. In addition, it is a matrix forming material that can be expected to have a coating with excellent mechanical strength. For this reason, when this hydrolyzable organosilane hydrolyzate is used as a matrix-forming material, hollow silica fine particles are formed more than other general organic resins in the case of forming a film composed of low refractive index fillers such as hollow silica fine particles. It is easy to form a film having high surface strength (see, for example, Patent Document 1, Patent Document 2, etc.).

  However, in applications where antifouling properties such as fingerprint wiping properties are strongly desired, the above hydrolyzable organosilane hydrolyzate as a matrix-forming material has insufficient water and oil repellency, It is necessary to add a hydrolyzable organosilane copolymer hydrolyzate having a fluorine-substituted alkyl group having excellent water and oil repellency to the matrix forming material. However, the hydrolyzable organosilane copolymer hydrolyzate having a fluorine-substituted alkyl group also has a film refractive index reduction effect due to fluorine, but has a tendency to reduce the surface strength of the film. Until oil repellency was developed, it was difficult to introduce a hydrolyzable organosilane copolymer hydrolyzate having a fluorine-substituted alkyl group.

In addition, when hollow silica fine particles are used as the low refractive index filler as described above, the hollow silica fine particles have a double structure of an outer shell and a cavity, and are obtained from general colloidal fine particles (primary particle diameter of 5 to 20 nm). In general, the primary particle size is large. Since the thickness of the coating formed as the antireflection coating is a thin film of about 100 nm, the surface smoothness of the coating containing the hollow silica fine particles is easily affected by the particle size of the hollow silica fine particles. For this reason, the surface of the coating is increased in surface roughness due to the hollow silica fine particles, the surface friction resistance is increased due to being caught on the surface of the coating, and the surface of the coating is easily scratched. It had the problem of being lowered.
JP 2003-201443 A JP 2002-79616 A

  The present invention has been made in view of the above points, and has a coating material composition and a coated article that can form a coating film having excellent antireflection performance, high surface strength, and high scratch resistance. Is intended to provide.

The coating material composition according to the present onset Ming, a coating material composition which outer shell comprising a hollow fine particles and the matrix-forming material formed of a metal oxide, the hollow fine particles with respect to the silanol group The metal oxide of the outer shell is treated with a hydrophobizing agent having a reactive functional group and a hydrophobic group in the molecule, and the hydroxyl group on the surface of the metal oxide is substituted with the hydrophobic group. Hydrophobizing agents are hexamethyldisilazane, hexamethyldisiloxane, trimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, triethylethoxysilane, triethylmethoxysilane, methyltrichlorosilane, ethyltrichlorosilane, methyl chloride, heptadecafluorodecyl Selected from triethoxysilane and above Matrix-forming material is copolymerized with at least one hydrolyzate, coating material composition characterized by comprising a silicone diol following (C) of the hydrolyzate and the following (B) (A) below .
(A) The general formula is SiX ₄ (X is a hydrolyzable group) (1)
Hydrolyzate obtained by hydrolyzing hydrolyzable organosilane represented by formula (B) Copolymerization hydrolysis of hydrolyzable organosilane of formula (1) and hydrolyzable organosilane having a fluorine-substituted alkyl group Product (C) Dimethyl silicone diol represented by the following formula (2)

In the coating material composition , n in the formula (2) of the silicone diol (C) is preferably 20-100.

In the coating material composition , the hollow fine particles include first particles having an average particle size of 40 to 80 nm and second particles having an average particle size of 1/10 to 2/3 of the particle size of the first particles. It is preferable to use what to do.

Further, in the coating material composition, non-hollow oxide fine particles containing fine particles having an average particle size of 40 to 80 nm as hollow fine particles and having an average particle size of 1/10 to 2/3 of the particle size of the hollow fine particles It is preferable to contain.

In the coating material composition, it is preferable to use only fine particles having an average particle diameter of 10 to 30 nm as the hollow fine particles.

In the coating material composition , the matrix-forming material preferably contains a hydrophobizing agent having a functional group that reacts with a silanol group and a hydrophobic group in the molecule.

Coated article according to the present onset Ming, the cured coating of the coating material composition, is intended to characterized in that it comprises the surface of the substrate.

Moreover, in the said coated article , it is preferable that the film thickness of the cured film of a coating material composition is 50-150 nm .

  Since the matrix-forming material contains at least one of the hydrolyzate (A) and the copolymer hydrolyzate (B), a cured film having a low refractive index can be formed. Even if the blending amount is decreased, a cured film having a low refractive index and excellent antireflection performance can be formed, and a cured film having a high surface strength can be formed. In addition, since the matrix-forming material contains the silicone diol (C), the silicone diol is introduced into the cured coating, and the surface frictional resistance of the cured coating can be reduced. This makes it possible to reduce scratches and make it difficult for scratches to enter, and to improve the scratch resistance of the cured coating.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The matrix-forming material used in the present invention is composed of at least one of a hydrolyzate (A) and a copolymer hydrolyzate (B), and a silicone diol (C). The hydrolyzate (A) and the silicone diol ( C), a combination of copolymer hydrolyzate (B) and silicone diol (C), hydrolyzate (A), copolymer hydrolyzate (B) and silicone diol (C) ) Can be used.

The hydrolyzate (A) used in the present invention is:
The general formula is SiX ₄ (X is a hydrolyzable group) (1)
The tetrafunctional hydrolyzate (tetrafunctional silicone resin) obtained by hydrolyzing the tetrafunctional hydrolyzable organosilane represented by these. Examples of the tetrafunctional hydrolyzable organosilane include a tetrafunctional organoalkoxysilane represented by the following formula (3).

Si (OR) ₄ (3)
“R” in the alkoxyl group “OR” in the formula (3) is not particularly limited as long as it is a monovalent hydrocarbon group, but a monovalent hydrocarbon group having 1 to 8 carbon atoms is preferable. Examples thereof include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl group. Among the alkyl groups contained in the alkoxide group, those having 3 or more carbon atoms may be linear such as n-propyl group, n-butyl group, isopropyl group, It may have a branch such as an isobutyl group or a t-butyl group.

  As the hydrolyzable group X of the tetrafunctional hydrolyzable organosilane, in addition to the above alkoxyl group, an acetoxy group, an oxime group (—O—N═C—R (R ′)), an enoxy group (—O—) C (R) = C (R ′) R ″), amino group, aminoxy group (—O—N (R) R ′), amide group (—N (R) —C (═O) —R ′) ( In these groups, R, R ′, and R ″ are each independently, for example, a hydrogen atom or a monovalent hydrocarbon group), halogen, and the like.

  And in preparing the hydrolyzate (A) which is a tetrafunctional silicone resin, it is carried out by hydrolyzing (including partial hydrolysis) a tetrafunctional hydrolyzable organosilane such as the above tetrafunctional organoalkoxysilane. Can do. Here, although the weight average molecular weight of the hydrolyzate (A), which is the resulting tetrafunctional silicone resin, is not particularly limited, it is cured by a smaller proportion of the matrix-forming material with respect to hollow fine particles such as hollow silica fine particles. In order to obtain the mechanical strength of the coating, the weight average molecular weight is preferably in the range of 200 to 2,000. If the weight average molecular weight is less than 200, the film forming ability may be inferior, and if it exceeds 2000, the mechanical strength of the cured film may be inferior.

  The copolymerized hydrolyzate (B) used in the present invention is a copolymerized hydrolyzate of a hydrolyzable organosilane and a hydrolyzable organosilane having a fluorine-substituted alkyl group.

  As the hydrolyzable organosilane, the tetrafunctional hydrolyzable organosilane of the above formula (1) is used. As the tetrafunctional hydrolyzable organosilane, the tetrafunctional organoalkoxysilane of the above formula (3) is used. Can be mentioned.

  Moreover, as a fluorine-substituted alkyl group containing hydrolyzable organosilane, what has a structural unit represented by following formula (4)-(6) is suitable.

(In the formula, R ¹ represents a fluoroalkyl group or perfluoroalkyl group having ¹ to 16 carbon atoms, and R ² represents an alkyl group, halogenated alkyl group, aryl group, alkylaryl group, arylalkyl having 1 to 16 carbon atoms. A group, an alkenyl group, an alkoxy group, a hydrogen atom or a halogen atom, X represents — (C _a H _b F _c ) —, a represents an integer of 1 to 12, b + c represents 2a, and b represents 0 And an integer of ˜24, c is an integer of 0 to 24. Such X is preferably a group having a fluoroalkylene group and an alkylene group.
A hydrolyzable organosilane and a hydrolyzable organosilane having a fluorine-substituted alkyl group are mixed, hydrolyzed, and copolymerized to obtain a copolymerized hydrolyzate (B). The mixing ratio (copolymerization ratio) of the hydrolyzable organosilane and the hydrolyzable organosilane having a fluorine-substituted alkyl group is not particularly limited. A hydrolyzable organosilane having a fluorine-substituted alkyl group is preferably in the range of 99/1 to 50/50. Although the weight average molecular weight of a copolymer hydrolyzate (B) is not specifically limited, The range of 200-5000 is preferable. If it is less than 200, the film-forming ability is inferior. Conversely, if it exceeds 5000, the film strength may be lowered.

  The silicone diol (C) used in the present invention is a dimethyl type silicone diol represented by the above formula (2). In the above formula (2), the repeating number n of dimethylsiloxane is not particularly limited, but a range of n = 20 to 100 is preferable. If n is less than 20, the effect of reducing frictional resistance as described below cannot be sufficiently obtained. Conversely, if n exceeds 100, the compatibility with other matrix forming materials tends to deteriorate. Yes, the transparency of the cured coating may be adversely affected, and the appearance of the cured coating may be uneven.

  The matrix-forming material is formed by containing at least one of the hydrolyzate (A) and the copolymer hydrolyzate (B) and the silicone diol (C). In the matrix forming material, the blending amount of the silicone diol (C) is not particularly limited, but is 1 to the total solid content of the coating material composition (the solid content in terms of the condensation compound of the hollow fine particles and the matrix forming material). A range of 10% by mass is preferred.

  On the other hand, hollow silica fine particles can be used as the hollow fine particles whose outer shell is formed of a metal oxide in the present invention. The hollow silica fine particles are those in which cavities are formed inside the outer shell, and are not particularly limited as long as they are such, but specifically, the following can be used. For example, hollow silica fine particles having a cavity inside an outer shell (shell) made of a silica-based inorganic oxide can be used. The silica-based inorganic oxide is (A) a single layer of silica, (B) a single layer of a composite oxide composed of silica and an inorganic oxide other than silica, and (C) the (A) layer and the (B) layer. Including a double layer. The outer shell may be porous having pores, or may be one in which the pores are closed by an operation described later and the cavity is sealed. The outer shell is preferably a plurality of silica-based coating layers including an inner first silica coating layer and an outer second silica coating layer. By providing the second silica coating layer on the outer side, the outer shell fine pores are closed and the outer shell is densified, and furthermore, hollow silica fine particles in which the inner cavity is sealed with the outer shell can be obtained. is there.

  The thickness of the first silica coating layer is preferably 1 to 50 nm, particularly preferably 5 to 20 nm. When the thickness of the first silica coating layer is less than 1 nm, it is difficult to maintain the particle shape, and there is a possibility that hollow silica fine particles cannot be obtained, and when forming the second silica coating layer, There is a possibility that a partial hydrolyzate of an organosilicon compound enters the pores of the core particles, and it is difficult to remove the core particle constituent components. On the other hand, when the thickness of the first silica coating layer exceeds 50 nm, the ratio of the cavities in the hollow silica fine particles may be reduced, and the refractive index may not be sufficiently lowered. Furthermore, the thickness of the outer shell is preferably in the range of 1/50 to 1/5 of the average particle diameter. The thickness of the second silica coating layer may be such that the total thickness with the first silica coating layer is in the range of 1 to 50 nm, and particularly in the case of densifying the outer shell, the range of 20 to 49 nm is preferable. It is.

In the cavity, there are the solvent used when preparing the hollow silica fine particles and / or the gas that enters during drying. The precursor material for forming the cavity may remain in the cavity. The precursor material may remain slightly attached to the outer shell or may occupy most of the interior of the cavity. Here, the precursor substance is a porous substance remaining after removing a part of the constituent components from the core particles for forming the first silica coating layer. As the core particles, porous composite oxide particles composed of silica and an inorganic oxide other than silica are used. Examples of the inorganic oxide include Al ₂ O ₃ , B ₂ O ₃ , TiO ₂ , ZrO ₂ , SnO ₂ , Ce ₂ O ₃ , P ₂ O ₅ , Sb ₂ O ₃ , MoO ₃ , ZnO ₂ and WO ₃ . 1 type or 2 or more types can be mentioned. Examples of the two or more inorganic oxides include TiO ₂ —Al ₂ O ₃ and TiO ₂ —ZrO ₂ . The solvent or gas is also present in the pores of the porous material. When the removal amount of the constituent components at this time increases, the volume of the cavity increases and hollow silica fine particles having a low refractive index are obtained. The transparent film obtained by blending the hollow silica fine particles has a low refractive index and an antireflection performance. Excellent.

  The coating material composition according to the present invention can be prepared by blending the matrix forming material and hollow fine particles. In the coating material composition, the weight ratio between the hollow fine particles and the other components is not particularly limited, but the hollow fine particles / other components (solid content) = 95/5 to 50/50. Preferably, it is set to 95/5 to 75/25. If the number of hollow fine particles is more than 95, the mechanical strength of the cured film obtained by the coating material composition may be reduced. Conversely, if the number of hollow fine particles is less than 50, the effect of developing the low refractive index of the cured film is small. There is a risk.

  Further, silica particles whose outer shell is not hollow can be added to the coating material composition. By blending the silica particles, the mechanical strength of the cured film formed by the coating material composition can be improved, and the surface smoothness and crack resistance can also be improved. It is. The form of the silica particles is not particularly limited, and may be, for example, a powder form or a sol form. When the silica particles are used in a sol form, that is, as colloidal silica, it is not particularly limited. For example, water-dispersible colloidal silica or a hydrophilic organic solvent-dispersible colloid such as alcohol can be used. . Generally, such colloidal silica contains 20 to 50% by mass of silica as a solid content, and the amount of silica can be determined from this value. It is preferable that the addition amount of this silica particle is 0.1-30 mass% with respect to the solid content whole quantity in a coating material composition. If the amount is less than 0.1% by mass, the effect due to the addition of the silica particles may not be obtained. Conversely, if it exceeds 30% by mass, the refractive index of the cured film may be adversely affected.

  Then, the coating material composition prepared as described above is applied to the surface of the base material to form a coating, and the coating is dried and cured to form a cured coating having a low refractive index on the surface. Goods can be obtained. The base material to which the coating material composition is applied is not particularly limited, but examples thereof include inorganic base materials typified by glass, metal base materials, organic base materials typified by polycarbonate and polyethylene terephthalate. Examples of the shape of the substrate include a plate shape and a film shape. Furthermore, one or more layers may be formed on the surface of the substrate.

  The method of coating the coating material composition on the surface of the substrate is not particularly limited. For example, brush coating, spray coating, dipping (dipping, dip coating), roll coating, flow coating, curtain coating. Various ordinary coating methods such as knife coating, spin coating, table coating, sheet coating, single wafer coating, die coating, and bar coating can be selected.

  Moreover, it is preferable to heat-treat this after drying the coating formed on the surface of the substrate. This heat treatment can further improve the mechanical strength of the cured coating. The temperature during the heat treatment is not particularly limited, but it is preferable to perform the treatment at a relatively low temperature of 100 to 300 ° C. for 5 to 30 minutes. Even if heat treatment is performed at such a low temperature, the same mechanical strength as when heat treatment is performed at a high temperature can be obtained, so that the film forming cost can be reduced, and as in the case of heat treatment at a high temperature. The type of the base material is not limited. In addition, for example, in the case of a glass substrate, since the thermal conductivity is low, it takes time for temperature rise and cooling, and the heat treatment at a high temperature slows down the processing speed, whereas the heat treatment at a low temperature conversely increases the processing speed. It is something that can be done.

  The film thickness of the cured film formed on the surface of the substrate can be appropriately selected according to the intended use and purpose and is not particularly limited, but is preferably in the range of 50 to 150 nm. Here, the product of the refractive index and the film thickness of the cured film is the optical film thickness, and the optical film thickness of the cured film needs to be set to 1 / 4λ in order for light of wavelength λ to have the lowest reflectance. is there. In order for the light having the wavelength λ = 540 nm, which is the object of antireflection, to have the minimum reflectance, when the refractive index of the cured film is 1.35, the film thickness of the cured film needs to be 100 nm. Yes (optical film thickness = 1.35 × 100 = 135≈1 / 4λ). Further, when the refractive index of the cured film is 1.42, the film thickness of the cured film needs to be 95 nm (optical film thickness = 1.42 × 95 = 13.4.apprxeq.1 / 4λ). Thus, when optically designing as an antireflection coating, the thickness of the cured coating is preferably in the range of 50 to 150 nm.

  Thus, if the coating material composition according to the present invention is used, a cured film having a low refractive index can be easily formed, which is suitable for antireflection applications. For example, when the refractive index of the base material is 1.60 or less, a cured coating having a refractive index of 1.60 or more is formed on the surface of the base material, and this is used as an intermediate layer. It is effective to form a cured film with the coating material composition according to the present invention. The cured film for forming the intermediate layer can be formed using a known high refractive index material, and if the refractive index of the intermediate layer is 1.60 or more, the coating material composition according to the present invention is used. Thus, the difference in refractive index from the cured film due to the above becomes large, and an antireflection substrate excellent in antireflection performance can be obtained. Moreover, in order to relieve the coloring of the cured film of the antireflection substrate, the intermediate layer may be formed of a plurality of layers having different refractive indexes. Examples of the use for antireflection include the outermost surface of a display, a side mirror of an automobile, a windshield, a side glass, an inner surface of a rear glass, other vehicle glass, and building material glass.

  Further, when forming a cured film having a low refractive index on the surface of the substrate as described above, the coating material composition contains a silicone diol as a part of the matrix forming material, and the cured film contains this silicone diol. Is introduced, the surface frictional resistance of the cured coating can be reduced. Therefore, it is possible to reduce the catch on the surface of the cured coating so that scratches are difficult to enter, and to improve the scratch resistance. In particular, the dimethyl type silicon diol used in the present invention is such that when the coating film is formed, the silicone diol is localized on the surface of the coating film and does not impair the transparency of the coating film (having a low haze ratio). In addition, the dimethyl type silicone diol is excellent in compatibility with the matrix forming material used in the present invention and has reactivity with the silanol group of the matrix forming material, so that it is fixed to the surface of the cured film as a part of the matrix. Yes, the surface of the hardened film is not removed when the surface of the hardened film is wiped, just like when silicone oil (both ends are methyl groups) is mixed. Thus, the scratch resistance can be maintained for a long time.

  Here, the average particle diameter of hollow fine particles, for example, hollow silica fine particles is generally in the range of 5 nm to 2 μm (note that the average particle diameter can be determined by a dynamic light scattering method). The average particle size of the hollow fine particles used in the present invention is not particularly limited, and for example, those having an average particle size in the range of 10 to 30 nm can be used. When the average particle diameter is less than 10 nm, only the thickness of the outer shell is obtained, and sufficient voids cannot be formed, and the particles are not substantially hollow fine particles. When the average particle diameter exceeds 30 nm, the surface of the cured film is affected by the particle size of the hollow fine particles, and the surface roughness of the cured film increases. That is, FIGS. 1A and 1B show the surface of the cured coating 3 composed of the hollow microparticles 1 and the matrix 2. As the particle size of the hollow microparticles 1 increases, the unevenness of the surface of the cured coating 3 increases. As a result, the surface roughness increases. For this reason, the surface frictional resistance of the cured coating 3 is increased and the scratch resistance is lowered. Also, the fingerprint oil 5 enters the recesses 4 formed on the surface of the cured coating 3 between the hollow fine particles 1 and is wiped. It becomes impossible to remove and the fingerprint wiping property is lowered. Therefore, the average particle diameter of the hollow fine particles is preferably in the range of 10 to 30 nm in order to form a smooth surface of the cured film and improve the scratch resistance and fingerprint wiping property.

  As the hollow fine particles, the first particles having an average particle size of 40 to 80 nm and the second particles having an average particle of 1/10 to 2/3 of the average particle size of the first particles are used in combination. One particle and the second particle can also be used in a mixed state. When the large-diameter first particles and the small-diameter second particles are mixed and used as hollow fine particles in this way, the small-diameter second particles 1b enter between the large-diameter first particles 1a as shown in FIG. Thus, the recesses between the first particles 1a are filled with the second particles 1b, and the surface roughness of the cured coating 3 can be reduced to reduce the surface roughness. Therefore, even if hollow fine particles having a large average particle diameter of 40 to 80 nm are used, the surface of the cured film can be formed smoothly to improve the scratch resistance and the fingerprint wiping property. When the particle diameter of the first particles is 40 to 80 nm as described above, a large void is formed inside, so that it is possible to obtain a high effect of reducing the coating refractive index. When the ratio of the average particle diameter of the second particles to the first particles having an average particle size of 40 to 80 nm is less than 1/10, the second particles cannot maintain the shape of the hollow particles, and are substantially not hollow particles. Conversely, if it exceeds 2/3, the effect of reducing the surface roughness by reducing the surface roughness cannot be obtained sufficiently. The mixing ratio of the first particles and the second particles is not particularly limited, but is preferably in the range of first particles / second particles = 95/5 to 50/50 in terms of mass ratio.

  Further, when hollow particles having an average particle size of 40 to 80 nm are used, non-hollow oxide particles having an average particle size of 1/10 to 2/3 of the average particle size of the hollow particles are mixed and used. It may be. By using non-hollow oxide fine particles having an average particle size of 1/10 to 2/3 mixed with hollow fine particles having an average particle size of 40 to 80 nm, the unevenness on the surface of the cured film can be reduced as described above. Thus, the surface roughness can be reduced, and the surface of the cured coating can be formed smoothly to improve the scratch resistance and the fingerprint wiping property. The mixing ratio of hollow fine particles and non-hollow oxide fine particles having an average particle size of 40 to 80 nm is not particularly limited, but the mass ratio is hollow fine particles / non-hollow oxide fine particles = 95/5 to 50/50. preferable. As the non-hollow oxide fine particles, the aforementioned silica particles in which the inside of the outer shell is not hollow can be used.

  In addition, as a hollow fine particle, the hollow fine particle is treated with a hydrophobizing agent having a functional group that reacts with a silanol group and a hydrophobic group in the molecule, and the hydroxyl group on the surface of the outer metal oxide is hydrophobized. What was substituted by the hydrophobic group of an agent can be used. Examples of functional groups that react with silanol groups include halogens, amino groups, imino groups, carboxyl groups, and alkoxyl groups, and examples of hydrophobic groups include alkyl groups, phenyl groups, and fluorides thereof. Etc.

  The hydrophobizing agent may have only one type or two or more types of functional groups and hydrophobic groups that react with silanol groups. Specific examples of such hydrophobizing agents include hexamethyldisilazane, hexamethyldisiloxane, trimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, triethylethoxysilane, triethylmethoxysilane, dimethyldichlorosilane, dimethyldiethoxysilane. And organic silane compounds such as methyltrichlorosilane and ethyltrichlorosilane. Besides these, carboxylic acids such as acetic acid, formic acid and succinic acid, and organic compounds such as alkyl halides such as methyl chloride. Can do. Two or more hydrophobizing agents may be used in combination.

  The method for the hydrophobization treatment is not particularly limited. For example, the hollow microparticles are infiltrated into the hollow microparticles by immersing and mixing the hollow microparticles in a solution in which the hydrophobization treatment agent is dissolved in a solvent. Thereafter, a method of performing a hydrophobization treatment reaction by heating as necessary may be mentioned. Examples of the solvent used for the hydrophobizing treatment include methanol, ethanol, toluene, benzene, N, N-dimethylformamide, and the like, but the solvent (in which the hydrophobizing agent is easily dissolved and the gel compound is contained) The material is not limited to these as long as it can replace the dispersion medium. The amount of the hydrophobizing agent used in the hydrophobizing treatment is preferably set to an amount that provides a number of moles that can sufficiently react with all the surface silanol groups of the hollow fine particles. For example, the mass ratio of hollow fine particles / hydrophobizing agent is preferably in the range of about 0.5 to 10, but this is a balance between the amount of solvent for performing the hydrophobizing reaction, temperature, time, etc., and cost and performance. Etc., and is not limited. Also, the amount of solvent used is not limited.

  By treating the hollow fine particles with the hydrophobic treatment agent in this way, the silanol groups on the surface of the metal oxide of the outer shell of the hollow fine particles are replaced with the hydrophobic groups of the hydrophobic treatment agent, and the surface of the hollow fine particles is hydrophobic. Thus, it is possible to reduce the permeation of water into the cured coating containing the hollow fine particles, and to improve the water resistance of the cured coating.

  Moreover, you may make it contain said hydrophobic treatment agent in a matrix formation material. By including the hydrophobic treatment agent in the matrix forming material in this way, the silanol groups and hydroxyl groups on the surface of the cured coating are replaced with the hydrophobic groups of the hydrophobic treatment agent, and the surface of the cured coating becomes hydrophobic and cured. The water resistance of the coating can be improved. The blending amount of the hydrophobizing agent to the matrix forming material is preferably in the range of the hydrophobizing agent / matrix forming material = 0.01 to 0.5 in terms of mass ratio.

  Hereinafter, the present invention will be specifically described by way of examples. Unless otherwise specified, all “parts” represent “parts by mass”, and “%” represents “% by mass” except for the reflectance and haze ratio described later. Further, the molecular weight is measured by GPC (gel permeation chromatography), using a standard polystyrene with a calibration curve using HLC8020 manufactured by Tosoh Corporation as a measurement model, and measuring the converted value.

Example 1
356 parts of methanol is added to 208 parts of tetraethoxysilane, 18 parts of water and 18 parts of 0.01N hydrochloric acid aqueous solution (“H ₂ O” / “OR” = 0.5) are mixed, and this is mixed using a disper. Mix well. This mixed solution was stirred in a thermostat at 25 ° C. for 2 hours to obtain a hydrolyzate (A) (tetrafunctional silicone resin) having a weight average molecular weight adjusted to 850.

  Moreover, hollow silica IPA (isopropanol) dispersion sol (solid content 20%, average primary particle diameter of about 60 nm, outer shell thickness of about 10 nm, manufactured by Catalyst Kasei Kogyo Co., Ltd.) was used as the hollow silica fine particles. Then, hollow silica fine particles are added to the matrix-forming material composed of the above-described tetrafunctional silicone resin so that the hollow silica fine particles / 4 functional silicone resin (condensation compound equivalent) has a mass ratio of 50/50 based on the solid content. IPA / Butyl acetate / Butyl cellosolve mixture so that the total solid content is 1% (a solution premixed so that 5% of the diluted solution is butyl acetate and 2% of the total amount is butyl cellosolve) Diluted with

  Next, a solution obtained by diluting dimethyl silicone diol (n≈40 in formula (2)) with ethyl acetate so as to have a solid content of 1% is used to obtain a solid content of hollow silica fine particles and tetrafunctional silicone resin (condensate equivalent). The coating material composition was prepared by adding so that the solid content of dimethyl silicone diol was 2% with respect to the sum.

This coating material composition was allowed to stand for 1 hour, and then surface-washed in advance with a UV-ozone cleaning machine (an excimer lamp “model H0011” manufactured by USHIO INC.), An acrylic plate (“Delaglass _TM HA” manufactured by Asahi Kasei Kogyo Co., Ltd., double-sided hard A hard coat surface having a coating treatment, a hard coat refractive index of 1.52 and a haze of 0.10) is coated with a wire bar coater to form a film having a film thickness of about 100 nm, and the film is formed in an oxygen atmosphere at 80 ° C. for 1 hour A cured coating was obtained by heat treatment.

(Example 2)
In Example 1, except that the solid content of dimethyl silicone diol was 4% with respect to the sum of the solid content of hollow silica fine particles and tetrafunctional silicone resin (condensate conversion) In the same manner as in No. 1, a coating material composition was prepared.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Example 3)
356 parts of methanol is added to 166.4 parts of tetraethoxysilane, 14.7 parts of heptadecafluorodecyltriethoxysilane (CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OC ₂ H ₅ ) ₃ ), and water 18 Part and 18 parts of 0.01N hydrochloric acid aqueous solution (“H ₂ O” / “OR” = 0.5) were mixed and mixed well using a disper. This mixed solution was stirred in a thermostatic bath at 25 ° C. for 2 hours to obtain a fluorine / ricone copolymer hydrolyzate (B) having a weight average molecular weight adjusted to 830.

  Next, hollow silica fine particles / fluorine / silicone copolymer hydrolyzate (condensation compound equivalent) are added to the matrix-forming material comprising the above-mentioned fluorine / silicone copolymer hydrolyzate (B) as in Example 1. Was added to a mass ratio of 50/50 based on the solid content, and further diluted with an IPA / butyl acetate / butyl cellosolve mixed solution in the same manner as in Example 1 so that the total solid content was 1%.

  Furthermore, a solution obtained by diluting dimethyl silicone diol (n≈40 in formula (2)) with ethyl acetate so as to have a solid content of 1% is obtained as a result of hollow silica fine particles and fluorine / silicone copolymer hydrolyzate (condensate conversion). The coating material composition was prepared by adding the solid content of dimethyl silicone diol to 2% of the total solid content.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

Example 4
In Example 1, a dimethyl silicone diol having n≈11 of formula (2) was used, and the solid content of dimethyl silicone diol was compared to the sum of the solid content of hollow silica fine particles and tetrafunctional silicone resin (condensate equivalent). A coating material composition was prepared in the same manner as in Example 1 except that the content was 4%.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Example 5)
In Example 1, a dimethyl silicone diol having n≈250 of the formula (2) was used, and the solid content of the dimethyl silicone diol with respect to the sum of the solid content of the hollow silica fine particles and the tetrafunctional silicone resin (condensate conversion). A coating material composition was prepared in the same manner as in Example 1 except that the content was 1%.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Example 6)
Example 1 except that a hollow silica IPA dispersion sol (solid content 20%, average primary particle diameter of about 35 nm, outer shell thickness of about 8 nm, manufactured by Catalyst Kasei Kogyo Co., Ltd.) is used as the hollow silica fine particles in Example 1. In the same manner, a coating material composition was prepared.

  Then, the coating material composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Example 7)
In the coating material composition of Example 1, together with hollow silica fine particles, silica methanol sol (“MA-ST” manufactured by Nissan Chemical Industries, Ltd., average particle diameter) as non-hollow silica fine particles in which no cavity is formed inside the outer shell 10-20 nm) in the same manner as in Example 1 except that the hollow silica fine particles / silica fine particles / silicone hydrolyzate (condensation compound equivalent) was blended so as to have a mass ratio of 40/10/50 based on the solid content. Thus, a coating material composition was prepared.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Comparative Example 1)
A coating material composition was prepared in the same manner as in Example 1 except that the dimethyl silicone diol was not blended in the coating material composition of Example 1.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Comparative Example 2)
A coating material composition was prepared in the same manner as in Example 1 except that the dimethyl silicone diol was not blended in the coating material composition of Example 3.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Comparative Example 3)
In Example 1, an alkyl-modified silicone oil (“XF42-A6131” manufactured by GE Toshiba Silicone) was used instead of dimethylsilicone diol, and the total solid content of hollow silica fine particles and tetrafunctional silicone resin (condensate conversion) was used. On the other hand, a coating material composition was prepared in the same manner as in Example 1 except that the solid content of the alkyl-modified silicone oil was 1%.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Comparative Example 4)
In Example 1, methylphenyl silicone oil (“TSF4300” manufactured by GE Toshiba Silicone Co., Ltd.) was used instead of dimethyl silicone diol, and the total solid content of hollow silica fine particles and tetrafunctional silicone resin (condensate conversion) A coating material composition was prepared in the same manner as in Example 1 except that the solid content of methylphenyl silicone oil was 1%.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

(Comparative Example 5)
In Example 1, fatty acid-modified dimethyl silicone oil (“TSF411” manufactured by GE Toshiba Silicone) was used in place of dimethyl silicone diol, and the total solid content of hollow silica fine particles and tetrafunctional silicone resin (condensate conversion) Thus, a coating material composition was prepared in the same manner as in Example 1 except that the solid content of the fatty acid-modified dimethyl silicone oil was 1%.

  The coating composition was applied in the same manner as in Example 1 and heat treated to obtain a cured film.

  About the cured film obtained in said Examples 1-7 and Comparative Examples 1-5, the reflectance, haze rate, refractive index, and mechanical strength were measured, and the performance evaluation of the cured film was performed. The results are shown in Table 1.

(5 ° relative reflectance)
The minimum reflectance was measured using a spectrophotometer ("U-4100" manufactured by Hitachi, Ltd.).

(Haze rate)
It measured using the haze meter (Nippon Denshoku Industries "NDH2000").

(Refractive index)
The refractive index was derived with a simple ellipsometer (“F20” manufactured by FILMTRICS).

(Mechanical strength)
The surface of the cured coating was rubbed with an abrasion tester (“HEIDON-14DR” manufactured by Shinbun Kagaku Co., Steel Wool # 0000, 250 kg load, 10 reciprocations), and the number of the cured coating was measured.

  As can be seen in Table 1, each example has a low haze ratio and few scratches in the wear test, and it is confirmed that the sample has high scratch resistance.

The surface part of a cured film is enlarged and illustrated, and (a) and (b) are cross-sectional views, respectively. It is sectional drawing which expands and illustrates the surface part of a cured film.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hollow microparticle 2 Matrix 3 Hardened film 4 Recessed part

Claims (8)

A coating material composition comprising hollow fine particles whose outer shell is formed of a metal oxide and a matrix-forming material, wherein the hollow fine particles contain functional groups that react with silanol groups and hydrophobic groups in the molecule. The metal oxide of the outer shell is treated with the hydrophobizing agent having the above, and the hydroxyl group on the surface of the metal oxide is substituted with the hydrophobic group. The hydrophobizing agent is hexamethyldisilazane, Hexamethyldisiloxane, trimethylchlorosilane, trimethylmethoxysilane, trimethylethoxysilane, triethylethoxysilane, triethylmethoxysilane, methyltrichlorosilane, ethyltrichlorosilane, methyl chloride, heptadecafluorodecyltriethoxysilane, the matrix forming material, following (a) Water decomposition products with the following (B) of at least one copolymer hydrolyzate, coating material composition characterized by comprising a silicone diol below (C).
(A) The general formula is SiX ₄ (X is a hydrolyzable group) (1)
Hydrolyzate obtained by hydrolyzing hydrolyzable organosilane represented by formula (B) Copolymerization hydrolysis of hydrolyzable organosilane of formula (1) and hydrolyzable organosilane having a fluorine-substituted alkyl group Product (C) Dimethyl silicone diol represented by the following formula (2)

  2. The coating material composition according to claim 1, wherein n in the formula (2) of the silicon diol (C) is 20 to 100.   As the hollow fine particles, those containing first particles having an average particle diameter of 40 to 80 nm and second particles having an average particle diameter of 1/10 to 2/3 of the particle diameter of the first particles are used. The coating material composition according to claim 1 or 2.   The hollow fine particles contain fine particles having an average particle size of 40 to 80 nm and non-hollow oxide fine particles having an average particle size of 1/10 to 2/3 of the particle size of the hollow fine particles. The coating material composition according to claim 1 or 2.   The coating material composition according to claim 1 or 2, wherein only the fine particles having an average particle diameter of 10 to 30 nm are used as the hollow fine particles. The matrix-forming material, the coating material according to any one of claims 1 to 5, characterized in that comprising a hydrophobizing agent having a functional group and a hydrophobic group that reacts with the silanol groups in the molecule Composition. A coated product comprising a cured film of the coating material composition according to any one of claims 1 to 6 on a surface of a substrate. The coated product according to claim 7 , wherein the coating film composition has a cured film thickness of 50 to 150 nm.

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