JP2006131734A - Method for preparing organosiloxane resin coating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preparing a transparent thermosetting type organosiloxane resin coating imparting abrasion and hot-water resistances and to provide a polycarbonate resin molded product having the surface protected with the coating. <P>SOLUTION: The organosiloxane resin coating is prepared by carrying out a condensation reaction of colloidal silica with a hydrolyzate of an alkoxysilane represented by formula (1) (wherein, R<SP>1</SP>and R<SP>2</SP>are each a 1-4C alkyl group, a vinyl group or a 1-3C alkyl group substituted with one or more groups selected from the group consisting of a methacryloxy group, an amino group, a glycidoxy group and a 3,4-epoxycyclohexyl group; R<SP>3</SP>is a 1-4C alkyl group; m and n are each any integer of 0, 1 and 2; and m+n is any integer of 0, 1 and 2). The method for preparation is characterized as follows. The reaction is carried out so that the average particle diameter of silica microparticles is 10-70 nm and the coefficient of variation based on the particle diameter is 20-40%. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for preparing an organosiloxane resin paint, an organosiloxane resin paint, and a polycarbonate resin molded body whose surface is protected with an organosiloxane resin, and more particularly, an optically transparent coating heat which imparts excellent wear resistance. The present invention relates to a method for preparing a curable organosiloxane resin coating, and a polycarbonate resin molded article excellent in wear resistance and hot water resistance, the surface of which is protected by the organosiloxane resin.

  Various coating compositions that help protect the surface of substrates have been used to date, and siloxane-based thermosetting hard coat agents are used especially for applications that require a high level of wear resistance. Has been. Many technical proposals have been made on this siloxane-based hard coat agent.

Patent Document 1 describes a coating composition containing a dispersion system of colloidal silica dispersed in an alcohol aqueous solution of a silanol condensate represented by the formula CH ₃ Si (OH) ₃ . Patent Documents 2 and 3 describe coating compositions in which colloidal silica is added to a hydrolyzed condensate of alkyltrialkoxysilane and tetraalkoxysilane. As described above, the above-described technical proposal has been made on the siloxane-based thermosetting hard coating agent using colloidal silica that a high level of wear resistance can be realized.

  By the way, in these siloxane-based hard coat agents, the alkoxysilane used as a raw material does not exist as it is, but exists as a condensate that is hydrolyzed or partially condensed, and the condensation is not only between the alkoxysilanes. Also, a condensation reaction occurs with the hydroxyl group on the surface of the colloidal silica. Therefore, the siloxane-based hard coating agent exists as a mixture of silica fine particles having various particle sizes, and the average size and variation of the particle size vary greatly depending not only on the composition of the raw material but also on the preparation method of the coating agent. However, the above-described conventional technology does not give any significant knowledge about a preparation method for providing a desirable particle size or particle size distribution of a siloxane-based hard coat agent.

Japanese Patent Laid-Open No. 51-002736 Japanese Unexamined Patent Publication No. Sho 63-27879 Japanese Patent Laid-Open No. 01-306476

  An object of the present invention is to provide a method for preparing an optically transparent thermosetting organosiloxane resin paint for coating that imparts excellent wear resistance and hot water resistance, a resin paint obtainable by such a preparation method, and the organosiloxane resin An object of the present invention is to provide a polycarbonate resin molded body whose surface is protected by the above.

  As a result of intensive studies to achieve this object, the inventors of the present invention prepared an organosiloxane resin paint after the particle diameter and particle system distribution of the prepared silica fine particles were applied to the surface of the plastic substrate. That the performance of the coating film (wear resistance and hot water resistance) can be improved by preparing silica fine particles having a specific particle size and particle system distribution. The headline, the present invention has been reached.

（但し、式中Ｒ^１、Ｒ^２はそれぞれ炭素数１〜４のアルキル基、ビニル基、またはメタクリロキシ基、アミノ基、グリシドキシ基、３，４−エポキシシクロヘキシル基からなる群から選ばれる１以上の基で置換された炭素数１〜３のアルキル基であり、Ｒ^３は炭素数１〜４のアルキル基であり、ｍ、ｎはそれぞれ０、１、２のいずれかの整数であり、ｍ＋ｎは０、１、２のいずれかの整数である） That is, according to the present invention,
1. (A) Organosiloxane resin coating containing silica fine particles obtained by condensation reaction of colloidal silica (component a) and (B) hydrolyzate of alkoxysilane represented by the following formula (1) or its condensate (component b) In preparing the a component, the average particle size of the silica fine particles is 10 to 70 nm, and the coefficient of variation {100 × (standard deviation / average particle size)} based on the particle size is 20 to 40%. A method for preparing an organosiloxane resin paint, which comprises reacting with component b.

(However, in the formula, each of R ¹ and R ² is one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, or a methacryloxy group, an amino group, a glycidoxy group, and a 3,4-epoxycyclohexyl group. An alkyl group having 1 to 3 carbon atoms substituted with a group, R ³ is an alkyl group having 1 to 4 carbon atoms, m and n are each an integer of 0, 1 or 2, and m + n is (It is an integer of 0, 1, 2)

2. The colloidal silica (component a) is 10 to 60% by weight, and the hydrolyzate of alkoxysilane or the condensate thereof (component b) is converted into R ¹ _m R ² _n SiO _{(4-mn) / 2.} 2. The method for preparing an organosiloxane resin coating material according to item 1 above, which is 40 to 90% by weight (the total amount of component a and component b is 100% by weight).

  3. 2. The method for preparing an organosiloxane resin coating material according to item 1 above, wherein the colloidal silica (component a) has a particle size of 5 to 50 nm.

  4). Furthermore, the preparation method of the organosiloxane resin coating material of the preceding clause 1 which contains 0.01-10 weight part of (C) hardening catalyst (c component) with respect to 100 weight part of total amounts of a component and b component.

  5. 2. The method for preparing an organosiloxane resin paint as described in 1 above, wherein the organosiloxane resin paint has a solid content of 10 to 70% by weight.

  6). 2. The method for preparing an organosiloxane resin paint according to item 1, wherein at least 50% by weight or more of the solvent is an alcohol having 1 to 4 carbon atoms as a solvent for the organosiloxane resin paint.

（但し、式中Ｒ^１、Ｒ^２はそれぞれ炭素数１〜４のアルキル基、ビニル基、またはメタクリロキシ基、アミノ基、グリシドキシ基、３，４−エポキシシクロヘキシル基からなる群から選ばれる１以上の基で置換された炭素数１〜３のアルキル基であり、Ｒ^３は炭素数１〜４のアルキル基であり、ｍ、ｎはそれぞれ０、１、２のいずれかの整数であり、ｍ＋ｎは０、１、２のいずれかの整数である） 7). (A) Organosiloxane resin coating containing silica fine particles obtained by condensation reaction of colloidal silica (component a) and (B) hydrolyzate of alkoxysilane represented by the following formula (1) or its condensate (component b) In which the average particle size of the silica fine particles is 10 to 70 nm and the coefficient of variation {100 × (standard deviation / average particle size)} based on the particle size is 20 to 40% Resin paint.

(However, in the formula, each of R ¹ and R ² is one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, or a methacryloxy group, an amino group, a glycidoxy group, and a 3,4-epoxycyclohexyl group. An alkyl group having 1 to 3 carbon atoms substituted with a group, R ³ is an alkyl group having 1 to 4 carbon atoms, m and n are each an integer of 0, 1 or 2, and m + n is (It is an integer of 0, 1, 2)

が提供される。 8). On at least one surface of the polycarbonate substrate, as a first layer, at least 50% by weight of the coating resin is an acrylic resin, and the acrylic resin contains 50 mol% or more of a repeating unit represented by the following formula (2). A polycarbonate resin having a surface protected by laminating a coating film resin, which is an acrylic resin, and then laminating a coating film layer obtained by thermosetting the organosiloxane resin paint according to claim 6 as a second layer thereon. Molded body.

Is provided.

(About colloidal silica of component a)
The colloidal silica used as component a in the present invention is preferably a colloidal dispersion of silica fine particles having a diameter of 5 to 50 nm, more preferably 10 to 40 nm in water or an organic solvent.

  The colloidal silica can be used in either a water dispersion type or an organic solvent dispersion type, but a water dispersion type is preferably used. In the case of water-dispersed colloidal silica, a large number of hydroxyl groups are present on the surface of the silica fine particles, which are strongly bonded to the alkoxysilane hydrolyzate or its condensate, so that a plastic laminate having superior wear resistance can be obtained. It is thought that

  The water-dispersed colloidal silica further includes an acidic aqueous dispersion type and a basic aqueous dispersion type. As the water-dispersed colloidal silica, either an acidic aqueous dispersion type or a basic aqueous dispersion type can be used. However, the aqueous dispersion type colloidal silica is acidic in terms of selection of a curing catalyst, appropriate hydrolysis of trialkoxysilane, and realization of a condensed state. An aqueous dispersion type colloidal silica is preferably used.

  As such colloidal silica, specifically, as a product dispersed in an acidic aqueous solution, as a product dispersed in a basic aqueous solution, Snowtex O of Nissan Chemical Industry Co., Ltd., Cataloid SN of Catalytic Chemical Industry Co., Ltd. Nissan Chemical Industries, Ltd. Snowtex 30, Snowtex 40, Catalytic Chemical Industry Co., Ltd. Cataloid S30, Cataloid S40, Nissan Chemical Industries, Ltd. MA-ST, IPA-ST , NBA-ST, IBA-ST, EG-ST, XBA-ST, NPC-ST, DMAC-ST, OSCAL1132, OSCAL1232, OSCAL1332, OSCAL1432, OSCAL1532, OSCAL1632, OSCAL1732, etc.

（但し、式中Ｒ^１、Ｒ^２はそれぞれ炭素数１〜４のアルキル基、ビニル基、またはメタクリロキシ基、アミノ基、グリシドキシ基、３，４−エポキシシクロヘキシル基からなる群から選ばれる１以上の基で置換された炭素数１〜３のアルキル基であり、Ｒ^３は炭素数１〜４のアルキル基であり、ｍ、ｎはそれぞれ０、１、２のいずれかの整数であり、ｍ＋ｎは０、１、２のいずれかの整数である） (About the hydrolyzate or its condensate of alkoxysilane of b component)
The hydrolyzate of alkoxysilane which is the component b of the present invention or a condensate thereof is a product obtained by hydrolyzing an alkoxysilane of the following formula (1) or condensing the hydrolyzate thereof.

(However, in the formula, each of R ¹ and R ² is one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, or a methacryloxy group, an amino group, a glycidoxy group, and a 3,4-epoxycyclohexyl group. An alkyl group having 1 to 3 carbon atoms substituted with a group, R ³ is an alkyl group having 1 to 4 carbon atoms, m and n are each an integer of 0, 1 or 2, and m + n is (It is an integer of 0, 1, 2)

  Examples of the alkoxysilane include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetraisobutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, and ethyl. Trimethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-a Nopropyltriethoxysilane, dimethyldimethoxysilane, vinylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, etc. Trialkoxysilane is preferable, and methyltrimethoxysilane and methyltriethoxysilane are particularly preferable. These can be used alone or in combination.

  Moreover, in order to obtain the coating composition which forms the coating layer excellent in especially abrasion resistance, it is preferable that 70 to 100 weight% in alkoxysilane is methyl trialkoxysilane.

  The component b is a mixture such as a product obtained by hydrolyzing part or all of the alkoxysilane and a condensate obtained by subjecting part or all of the hydrolyzate to a condensation reaction, which are obtained by subjecting to a sol-gel reaction. It is.

(About preparation of organosiloxane resin paint)
A preferred process for preparing the organosiloxane resin coating is described below.
First, the colloidal silica dispersion is made to contain an amount of water necessary for the hydrolysis reaction of the alkoxysilane of the formula (1), and an acid and a pH adjuster are added as necessary to adjust the pH of the agent to that of the alkoxysilane. Adjust to pH 0.5-4, appropriate for hydrolysis. More preferably, it is adjusted to 1.0 to 3.5. In the case of the acidic aqueous solution dispersion type, the pH of the colloidal silica dispersion is often between 2.5 and 4. In this case, it is not always necessary to add an acid or a pH adjusting agent for adjusting the pH, but in order to accelerate the progress of the hydrolysis reaction, an acid is added when the reaction is performed on the more acidic side.

  When using basic aqueous dispersion type colloidal silica, it is necessary to use an acid in order to adjust pH. Such acids include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, nitrous acid, perchloric acid, sulfamic acid, formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, succinic acid, maleic acid, lactic acid, paratoluene sulfone. Examples thereof include organic acids such as acids, and organic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, succinic acid, and maleic acid are preferable, and acetic acid is particularly preferable from the viewpoint of easy control of pH.

  When an inorganic acid is used as such an acid, it is usually used in a concentration of 0.0001 to 2 N, preferably 0.001 to 0.1 N, and when an organic acid is used, it is usually based on 100 parts by weight of alkoxysilane. It is used in the range of 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight.

  It is also preferable to add a trace amount of salt or base to adjust the pH to make the system a buffer solution of pH. Such salts or bases include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, choline, quaternary ammonium hydroxides such as benzyltrimethylammonium hydroxide, tetrabutylammonium hydroxide, trimethylamine, Amines such as ethylenediamine and butylamine, ammonia, and organic carboxylates of these bases are used.

Subsequently, the alkoxysilane of the said Formula (1) is added to the colloidal silica prepared as mentioned above, and a hydrolysis condensation reaction is carried out.
Here, the water necessary for the hydrolysis reaction of the alkoxysilane is supplied from this dispersion when a water-dispersed colloidal silica dispersion is used, and water may be further added if necessary. The amount of water used is usually 1 to 10 equivalents, preferably 1.5 to 7 equivalents, more preferably 3 to 5 equivalents of water relative to 1 equivalent of alkoxysilane.

  By adding alkoxysilane to colloidal silica, the initial reaction becomes a reaction at an appropriate pH with excess water, and alkoxysilane first undergoes a hydrolysis reaction and then gradually undergoes a condensation reaction. Become. In addition, the condensation reaction is not an alkoxysilane hydrolyzate, but an environment in which a condensation reaction between the hydroxyl group of the alkoxysilane hydrolyzate and the hydroxyl group on the colloidal silica surface easily occurs. In this way, the coating agent becomes a homogeneous coating agent having colloidal silica as a core.

  The conditions for the hydrolysis and condensation reaction of the alkoxysilane vary depending on the type of alkoxysilane used and the type and amount of colloidal silica coexisting in the system, but the hydrolysis reaction of the alkoxysilane is an exothermic reaction. Yes, it is desirable that the temperature of the reaction system does not exceed 60 ° C. at the maximum. The temperature of the reaction system is preferably 20 to 60 ° C., more preferably 20 to 50 ° C., and particularly preferably 20 to 40 ° C. The reaction time is usually 2 hours to several days. It is also preferable to allow the hydrolysis reaction to proceed sufficiently under such conditions and to allow the condensation reaction to proceed at 40 to 80 ° C. for 2 hours to several days in order to stabilize the coating agent.

（但し、式中Ｒ^１、Ｒ^２はそれぞれ炭素数１〜４のアルキル基、ビニル基、またはメタクリロキシ基、アミノ基、グリシドキシ基、３，４−エポキシシクロヘキシル基からなる群から選ばれる１以上の基で置換された炭素数１〜３のアルキル基であり、ｍ、ｎはそれぞれ０、１、２のいずれかの整数であり、ｍ＋ｎは０、１、２のいずれかの整数である） By this reaction, the alkoxysilane of the formula (1) is hydrolyzed to a hydrolyzate represented by the following formula (3).

(However, in the formula, each of R ¹ and R ² is one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, or a methacryloxy group, an amino group, a glycidoxy group, and a 3,4-epoxycyclohexyl group. A C 1-3 alkyl group substituted with a group, m and n are each an integer of 0, 1 or 2, and m + n is an integer of 0, 1 or 2)

  Si—OH generated from alkoxysilane forms a Si—O—Si bond by causing a condensation reaction with Si—OH in colloidal silica and Si—OH of an alkoxysilane hydrolyzate molecule different from this molecule, The produced condensate also undergoes a condensation reaction with another Si—OH to form a Si—O—Si bond. This hydrolysis reaction and condensation reaction proceed partially but not completely.

  The organosiloxane resin (silica fine particles after condensation reaction) in the organosiloxane resin coating has an appropriate hydrolysis and condensation ratio, and if the hydrolysis reaction is not sufficiently progressed, the raw material alkoxysilane is evaporated during thermal curing. Hair cracks occur due to a rapid curing reaction. In addition, if the condensation reaction proceeds too much, the particle size of the silica fine particles in the paint (sol) becomes too large, and an appropriate crosslinking reaction becomes difficult at the time of thermosetting, so that the wear resistance is lowered. The reaction state of the organosiloxane resin is the average particle diameter of silica fine particles chemically bonded with the alkoxysilane hydrolysis condensate having colloidal silica as the core and the variation coefficient based on the particle diameter {100 × (standard deviation / average particle diameter)} The average particle diameter and the coefficient of variation can be obtained from a dynamic light scattering method.

  In the present invention, the average particle size of the silica fine particles in the organosiloxane resin coating is 10 to 70 nm, preferably 15 to 70 nm, and more preferably 20 to 65 nm.

  In the present invention, the coefficient of variation based on the particle size of the silica fine particles in the organosiloxane resin coating is 20 to 40%. The coefficient of variation of the colloidal silica used as component a is a few percent to less than 20% and has a uniform size, but the hydrolyzate of alkoxysilane or its condensate (component b) is chemically bonded around the colloidal silica. As a result, the size of the colloidal silica varies and the coefficient of variation increases. At this time, if the coefficient of variation based on the particle size of the silica fine particles chemically bonded to the alkoxysilane hydrolyzed condensate having colloidal silica as the core remains less than 20%, the hydrolysis reaction or condensation reaction of the organosiloxane resin is insufficient. This indicates that the occurrence of hair cracks tends to increase during thermosetting. Further, if the condensation reaction is advanced so that the coefficient of variation exceeds 40%, an appropriate cross-linking reaction becomes difficult at the time of thermosetting, so that a coating film having sufficient abrasion resistance cannot be obtained.

In the present invention, the mixing ratio of each component of the component a and component b is the stability of the organosiloxane resin obtained after the hydrolysis and condensation reaction, the transparency of the coating film obtained by curing the organosiloxane resin paint, It is determined from the points of wear resistance, scratch resistance, adhesion, crack occurrence and the like. When the total of the a component and the b component is 100% by weight, the preferable mixing ratio of these two components is 10 to 60 for the a component. wt%, b component is 40 to 90 wt% in terms of ^{_{R 1 m R 2 n SiO (}} 4-m-n) / 2, and more preferably 10 to 40% by weight component a, b components R It is 60 to 90% by weight in terms of ¹ _m R ² _n SiO _{(4-mn) / 2} .

(About solvent of organosiloxane resin paint)
As the solvent used in the organosiloxane resin paint of the present invention, it is necessary that the organosiloxane resin is stably dissolved, and for that purpose, at least 20% by weight or more, preferably 50% by weight or more is alcohol. desirable. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-ethoxyethanol, 4-methyl-2-pentanol, and 2-butoxy. Ethanol etc. are mentioned, C1-C4 low boiling point alcohol is preferable, and 2-propanol is especially preferable at the point of solubility, stability, and coating property.

  When organosiloxane resin paint uses water in water-dispersed colloidal silica, water that does not participate in the hydrolysis reaction, lower alcohol generated by hydrolysis of alkoxysilane, and organic solvent-dispersed colloidal silica Includes an organic solvent of the dispersion medium and an acid added for adjusting the pH of the organosiloxane resin coating.

  Acids used for pH adjustment include hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, nitrous acid, perchloric acid, sulfamic acid and other inorganic acids, formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, succinic acid, maleic acid Examples thereof include organic acids such as acid, lactic acid, and paratoluenesulfonic acid, and organic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, oxalic acid, succinic acid, and maleic acid are preferable from the viewpoint of easy control of pH.

  Other solvents must be miscible with water / alcohol, for example, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, ethers such as tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, acetic acid Examples thereof include esters such as ethyl and ethoxyethyl acetate.

  The solvent is preferably used in an amount of 50 to 900 parts by weight, more preferably 150 to 700 parts by weight, based on 100 parts by weight of the organosiloxane resin solid content. The organosiloxane resin coating has a solid content of preferably 10 to 70% by weight, more preferably 12.5 to 40% by weight.

  In the organosiloxane resin coating of the present invention, the pH is preferably adjusted to 4.5 to 6.5, more preferably 5.0 to 6.0 by adjusting the contents of the acid and the curing catalyst described later. desirable. Thereby, the gelation of the organosiloxane resin paint at room temperature can be prevented, and the storage stability can be increased. The organosiloxane resin paint usually becomes a stable paint by further aging for several hours to several days.

(About curing catalyst)
The organosiloxane resin paint of the present invention preferably further contains a curing catalyst as a catalyst when applied to a plastic substrate. Such catalysts include formic acid, propionic acid, butyric acid, lactic acid, tartaric acid, lithium salts of aliphatic carboxylic acids such as succinic acid, alkali metal salts such as sodium salt and potassium salt, benzyltrimethylammonium salt, choline salt, tetramethylammonium salt Examples thereof include quaternary ammonium salts such as salts and tetraethylammonium salts. Specifically, sodium acetate, potassium acetate, choline acetate, and benzyltrimethylammonium acetate are preferably used. When a basic water-dispersed colloidal silica is used as the colloidal silica and an aliphatic carboxylic acid is used as the acid during the hydrolysis of the alkoxysilane, a curing catalyst is already contained in the organosiloxane resin coating. It will be. The content of the curing catalyst varies depending on the composition of the organosiloxane resin, the degree of hydrolysis, the progress of the condensation reaction, and the thermosetting conditions, but is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the organosiloxane resin. More preferably, it is 0.1 to 5 parts by weight. When the content is less than 0.01 parts by weight, it is difficult to obtain a sufficient curing rate. When the content is more than 10 parts by weight, the storage stability of the organosiloxane resin coating may be lowered or a precipitate may be formed.

(Other additives)
Furthermore, a known leveling agent can be blended with the organosiloxane resin paint of the present invention for the purpose of improving the coatability and the smoothness of the resulting coating film.
Examples of such leveling agents include silicone compounds SH200-100cs, SH28PA, SH29PA, SH30PA, Toray Dow Corning Silicone Co., Ltd., silicone compounds KP321, KP322 from Shin-Etsu Chemical Co., Ltd., ST83PA, ST80PA, ST97PA, ST86PA, SH21PA. , KP323, KP324, KP326, KP340, KP341, fluorinated surfactants F-179, F-812A, F-815 from Dainippon Ink & Chemicals, Inc., and the like. These leveling agents may be used alone or in combination of two or more thereof, and the range of 0.01 to 2 parts by weight with respect to 100 parts of the organosiloxane resin is preferable.

  Moreover, you may add a ultraviolet absorber, dye, a pigment, a filler, etc. to an organosiloxane resin coating material in the range which does not impair the objective of this invention. An acrylic resin may be added for the purpose of improving flexibility.

(About transparent plastic moldings)
The organosiloxane resin paint prepared in the present invention is applied to a transparent plastic substrate. The transparent plastic substrate has a haze value of 10% or less. Specifically, polycarbonate resin, acrylic resin such as polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, poly (ethylene-2,6-naphthalate) And polyester resins such as polystyrene, polypropylene, polyarylate, and polyethersulfone. A polycarbonate resin and an acrylic resin are preferable due to their usefulness as a base material having excellent wear resistance, and a polycarbonate resin is particularly preferable.

  In addition, when a polycarbonate resin substrate is used, the organosiloxane resin paint can be applied directly to the polycarbonate resin substrate, but an acrylic resin layer is formed as a primer layer on the polycarbonate resin substrate, A method of applying an organosiloxane resin coating is preferably employed because of improved adhesion and the like.

  As a coating method of the organosiloxane resin paint, a dip coating method, a flow coating method, a spray coating method, a spin coating method, a roller coating method, a bar coating method, or the like is appropriately selected according to the shape of the substrate to be coated. can do.

  The thickness of the organosiloxane resin layer (coat layer) is usually 2 to 10 μm, preferably 3 to 8 μm. When the thickness of the coat layer is within such a range, cracks are not generated in the coat layer due to the stress generated at the time of thermosetting, and the adhesion between the coat layer and the substrate is not lowered. A desired coating layer having sufficient wear resistance can be obtained.

  The coating layer is heat-cured after coating and is in close contact with the substrate. The thermosetting is preferably performed at a high temperature within a range where there is no problem in the heat resistance of the base material because the curing can be completed earlier. At normal temperature, thermosetting does not proceed and a cured film cannot be obtained. This means that the organosiloxane resin solid content in the organosiloxane resin paint of the present invention is partially condensed. In the process of thermosetting, the remaining Si—OH undergoes a condensation reaction to form a Si—O—Si bond, resulting in a coat layer with excellent wear resistance. When thermosetting is usually applied to a polycarbonate substrate in the range of 50 ° C to 400 ° C for 10 minutes to 4 hours, preferably in the range of 80 ° C to 160 ° C for 20 minutes to 2 hours, most preferably 110 ° C to 135 ° C. Heat cure for 30 minutes to 1 hour.

  The organosiloxane resin paint of the present invention forms a transparent coating layer excellent in each point of wear resistance, scratch resistance, hardness, hot water resistance, organic solvent resistance, acid resistance, and adhesion to a substrate, and is high. The wear of the substrate surface can be prevented at the level.

  The polycarbonate resin is, for example, a polycarbonate resin obtained by reacting a dihydric phenol and a carbonate precursor by an interfacial polycondensation method or a melting method. Representative examples of the dihydric phenol include 2,2-bis (4-hydroxyphenyl) propane (commonly referred to as bisphenol A), 2,2-bis (3-methyl-4-hydroxyphenyl) propane, Bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 2,2-bis (4-hydroxy) Phenyl) butane, 2,2-bis (4-hydroxyphenyl) -3-methylbutane, 9,9-bis {(4-hydroxy-3-methyl) phenyl} fluorene, 2,2-bis (4-hydroxyphenyl) -3,3-dimethylbutane, 2,2-bis (4-hydroxyphenyl) -4-methylpentane, 1,1-bis (4-hydroxyphenyl) 3,3,5-trimethylcyclohexane and α, α′-bis (4-hydroxyphenyl) -m-diisopropylbenzene, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, and the like. But bisphenol A is preferred. These dihydric phenols can be used alone or in admixture of two or more.

  As the carbonate precursor, carbonyl halide, carbonate ester, haloformate or the like is used, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol, and the like.

  When producing a polycarbonate resin by reacting the dihydric phenol and the carbonate precursor by an interfacial polycondensation method or a melting method, a catalyst, a terminal terminator, a dihydric phenol antioxidant, etc. are used as necessary. Also good. The polycarbonate resin may be a branched polycarbonate resin copolymerized with a trifunctional or higher polyfunctional aromatic compound, or may be a polyester carbonate resin copolymerized with an aromatic or aliphatic difunctional carboxylic acid, Moreover, the mixture which mixed 2 or more types of the obtained polycarbonate resin may be sufficient.

  In the interfacial polycondensation method using phosgene, the reaction is carried out in the presence of an acid binder and an organic solvent. Examples of the acid binder include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and amine compounds such as pyridine, and examples of the solvent include halogenated hydrocarbons such as methylene chloride and chlorobenzene. In order to accelerate the reaction, a catalyst such as a tertiary amine or a quaternary ammonium salt can also be used. The reaction temperature is usually 0 to 40 ° C., and the reaction time is several minutes to 5 hours.

  The melting method using diphenyl carbonate is carried out by a method in which a predetermined proportion of a dihydric phenol component and diphenyl carbonate are stirred with heating in an inert gas atmosphere to distill the alcohol or phenols produced. The reaction temperature varies depending on the boiling point of the alcohol or phenol produced, but is usually in the range of 120 to 350 ° C. The reaction is completed while distilling off the alcohol or phenol produced by reducing the pressure from the beginning. Moreover, in order to accelerate | stimulate reaction, the catalyst for normal transesterification can also be used.

The molecular weight of the polycarbonate resin is preferably 10,000 to 50,000, more preferably 15,000 to 35,000 in terms of viscosity average molecular weight (M). A polycarbonate resin having such a viscosity average molecular weight is preferable because sufficient strength is obtained and the melt fluidity during molding is good. The viscosity average molecular weight referred to in the present invention is obtained by inserting the specific viscosity (η _sp ) obtained from a solution obtained by dissolving 0.7 g of polycarbonate resin in 100 ml of methylene chloride at 20 ° C. into the following equation.
η _sp /c=[η]+0.45×[η] ² c
[Η] = 1.23 × 10 ⁻⁴ M ^0.83
(Where c = 0.7, [η] is the intrinsic viscosity)

  When producing such a polycarbonate resin, if necessary, stabilizers such as phosphites, phosphates, and phosphonates, low molecular weight polycarbonates of tetrabromobisphenol A, tetrabromobisphenol A, and flame retardants such as decabromodiphenol Coloring agents, lubricants and the like can be added.

（但し、式中Ｒ^４は炭素数１〜４のアルキル基である。）
で示される繰り返し単位を５０モル％以上含むアクリル樹脂が好ましく、具体的には５０モル％以上のアルキルメタクリレートモノマーと５０モル％以下のビニル系モノマーを重合して得られるポリマーが挙げられる。アルキルメタクリレートモノマーとしては、メチルメタクリレート、エチルメタクリレート、プロピルメタクリレートおよびブチルメタクリレートが挙げられ、これらは単独または２種以上を混合して使用できる。なかでもメチルメタクリレートおよびエチルメタクリレートが好ましい。 The coating resin preferably formed as a primer layer on the polycarbonate resin substrate is an acrylic resin in which at least 50% by weight of the coating resin is an acrylic resin, and the acrylic resin has the following formula (2)

(However, in the formula, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms.)
An acrylic resin containing 50 mol% or more of the repeating unit represented by the formula (II) is preferred, and specifically, a polymer obtained by polymerizing 50 mol% or more of an alkyl methacrylate monomer and 50 mol% or less of a vinyl monomer is mentioned. Examples of the alkyl methacrylate monomer include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate, and these can be used alone or in admixture of two or more. Of these, methyl methacrylate and ethyl methacrylate are preferred.

  Further, as other vinyl monomers, those which can be copolymerized with alkyl methacrylate monomers are used, and acrylic acid, methacrylic acid or derivatives thereof are preferably used particularly in terms of durability such as adhesion or weather resistance. . Specifically, acrylic acid, methacrylic acid, acrylic acid amide, methacrylic acid amide, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, N, N-diethylaminoethyl methacrylate, glycidyl methacrylate, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 2- (2'- Hydroxy-5-methacryloxyethylphenyl) -2H-benzotriazole, 2- (2'-hydroxy-5-acryloxyethyl) Eniru) -2H- benzotriazole, etc. These can be used alone or in combination. Moreover, the mixture which mixed 2 or more types of acrylic resin may be sufficient.

  The acrylic resin is preferably a thermosetting type, and desirably contains a vinyl monomer having a crosslinkable reactive group of 0.01 mol% to 50 mol%. Examples of vinyl monomers having such a crosslinkable reactive group include acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, vinyltrimethoxysilane, and 3-methacryloxypropyltrimethoxysilane. , 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldimethoxysilane and the like.

  Among them, acrylic monomers having a hydroxyl group such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, etc. are used as vinyl monomers having a crosslinkable reactive group, and polyisocyanate compounds or their compounds are used as crosslinking agents. A thermosetting urethane acrylic resin using a polyisocyanate compound precursor that generates a derivative can be preferably used.

  The molecular weight of the acrylic resin is preferably 20,000 or more in terms of weight average molecular weight, more preferably 50,000 or more, and those having a weight average molecular weight of 10 million or less are preferably used. The acrylic resin having such a molecular weight range is preferable because performance such as adhesion and strength as a primer layer is sufficiently exhibited.

  As a method of forming the acrylic resin layer (primer layer) used in the present invention, a coating resin component such as an acrylic resin and additional components such as a light stabilizer and an ultraviolet absorber described later are used as a transparent plastic as a base material. This is carried out by dissolving in a volatile solvent that does not react or dissolve the transparent plastic, applying this acrylic coating paint to the surface of the transparent plastic substrate, and then removing the solvent by heating or the like. If necessary, it is also preferable to further crosslink the crosslinkable group by heating to 40 to 140 ° C. after removing the solvent.

  Examples of the solvent include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ethers such as tetrahydrofuran, 1,4-dioxane, and 1,2-dimethoxyethane, esters such as ethyl acetate and ethoxyethyl acetate, methanol, Alcohols such as ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, 2-ethoxyethanol, 4-methyl-2-pentanol, 2-butoxyethanol, n -Hexanes, n-heptane, isooctane, benzene, toluene, xylene, gasoline, light oil, kerosene and other hydrocarbons, acetonitrile, nitromethane, water, etc. These may be used alone or in combination of two or more You may mix and use. The concentration of the solid content composed of the coating resin in the acrylic coating paint is preferably 1 to 50% by weight, and more preferably 3 to 30% by weight.

The acrylic coating paint may contain a light stabilizer, an ultraviolet absorber, and a silane coupling agent for the purpose of improving the weather resistance of the plastic substrate.
Examples of the light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (2, 2,6,6-tetramethyl-4-piperidyl) sebacate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-octanoyloxy-2,2,6,6-tetramethylpiperidine, Bis (2,2,6,6-tetramethyl-4-piperidyl) diphenylmethane-p, p'-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) benzene-1,3- Hindered amines such as disulfonate, bis (2,2,6,6-tetramethyl-4-piperidyl) phenyl phosphite, nickel bis (octylphenyl sulfite) And nickel complexes such as nickel complex-3,5-di-t-butyl-4-hydroxybenzyl phosphate monoethylate, nickel dibutyldithiocarbamate, etc. These light stabilizers may be used alone or in combination of two or more. The amount is preferably 1 to 50 parts by weight, more preferably 1 to 10 parts by weight, based on 100 parts by weight of the coating film resin.

  Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and the like. Benzophenones, 2- (5'-methyl-2'-hydroxyphenyl) benzotriazole, 2- (3'-t-butyl-5'-methyl-2'-hydroxyphenyl) benzotriazole, 2- (3 ' , 5'-di-t-butyl-2'-hydroxyphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) benzotriazole and other benzotriazoles, ethyl-2 -Cyano-3,3-diphenyl acrylate, 2-ethylhexyl-2-cyano-3, -Cyanoacrylates such as diphenyl acrylate, salicylates such as phenyl salicylate, p-octylphenyl salicylate, benzylidene malonates such as diethyl-p-methoxybenzylidene malonate, bis (2-ethylhexyl) benzylidene malonate, 2- ( 4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(methyl) oxy] -phenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl ) -5-[(Ethyl) oxy] -phenol, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(propyl) oxy] -phenol, 2- (4 , 6-Diphenyl-1,3,5-triazin-2-yl) -5-[(butyl) oxy] -phenol, 2- (4,6- Triazines such as phenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol, 2- (2'-hydroxy-5-methacryloxyethylphenyl) -2H-benzotriazole And a vinyl monomer copolymerizable with the monomer, 2- (2'-hydroxy-5-acryloxyethylphenyl) -2H-benzotriazole, and a vinyl monomer copolymerizable with the monomer Examples thereof include metal oxide fine particles such as a copolymer, titanium oxide, cerium oxide, zinc oxide, tin oxide, tungsten oxide, zinc sulfide, and cadmium sulfide. Of these, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole is preferable. These ultraviolet absorbers may be used alone or in combination of two or more, and are preferably used in an amount of 0.1 to 100 parts by weight, more preferably 0.1 to 50 parts by weight, based on 100 parts by weight of the coating resin.

  Examples of the silane coupling agent include γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-β-. (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane / hydrochloride, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriacetoxysilane, γ-anilinopropyltrimethoxy Examples include silane, vinyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-ureidopropyltriethoxysilane and the like, and partial hydrolysis condensates of the above silane coupling agents can also be used. By adding such a silane coupling agent, the adhesion between the transparent plastic substrate and the acrylic resin layer (first layer) and between the first layer and the organosiloxane resin (second layer) is maintained over a long period of time. These silane coupling agents may be used alone or in combination of two or more, and are preferably used in an amount of 0.1 to 50 parts by weight, more preferably 0.2 to 10 parts by weight, based on 100 parts by weight of the coating resin. .

  The acrylic coating paint is applied to the plastic substrate by bar coating, dip coating, flow coating, spray coating, spin coating, roller coating, etc., depending on the shape of the substrate to be coated. It can be selected appropriately. The substrate coated with the coating paint is usually dried and removed at a temperature from room temperature to a temperature lower than the heat distortion temperature of the substrate, and further heated to 40 to 140 ° C. after removing the solvent if necessary. Thus, a crosslinkable group is cross-linked, and a transparent plastic base material in which the coating film resin is laminated as the first layer is obtained.

  The thickness of the coating resin layer of the first layer may be a film thickness that is sufficient to sufficiently bond the transparent plastic substrate and the second layer and to maintain the necessary amount of the additive. The thickness is preferably 0.1 to 10 μm, more preferably 1 to 5 μm.

  By forming the first layer made of a coating film resin mainly composed of the acrylic resin, the adhesion between the second layer and the transparent plastic substrate is improved, and the transparent plastic molded article is excellent in wear resistance and weather resistance. Can be obtained.

  The coating layer obtained from the organosiloxane resin paint of the present invention has good appearance, transparency, scratch resistance, hardness, hot water resistance, adhesion, organic solvent resistance, and acid resistance, and particularly in wear resistance and hot water resistance. It is excellent and can prevent the surface of the base material from being worn at a high level that has not been obtained conventionally. In particular, those coated on one or both surfaces of the polycarbonate sheet surface (preferably double-sided coating) are suitably used for automobile window glass and sunroof, and the industrial effects produced are particularly remarkable.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the obtained molded object (transparent polycarbonate resin sheet which has a coating layer) was evaluated with the following method. Moreover, the part in an Example means a weight part.

  (1) Appearance evaluation: The appearance of the double-sided coating layer of the test piece (repellency, whitening, presence of foreign matter) and the presence or absence of cracks (cracks) were visually confirmed.

  (2) Adhesiveness: Nichiban adhesive tape (trade name “Cerotape” (registered trademark)) is made on one side of the double-sided coating layer with a cutter knife at 100 squares with a 1 mm interval, and peeled off strongly vertically. The number of grids remaining on the substrate was evaluated (based on JIS K5400).

(3) Scratch resistance: One surface of the double-sided coating layer was rubbed with # 0000 steel wool, and then the surface damage state was visually evaluated in five stages.
1: No damage even when rubbed strongly 2: Slightly hurt when rubbed strongly 3: Slightly hurt when rubbed strongly 4: Scratched when rubbed strongly 5: Just rubbed slightly to hurt

  (4) Abrasion resistance: According to JIS K6735, one side of the double-sided coating layer was subjected to a Taber abrasion test of 500 revolutions with a load of 500 g using a wear wheel of CS-10F manufactured by Calibrase. And the difference ΔH between the haze and the haze before the Taber abrasion test was measured and evaluated. However, the wear wheel was refaced at 25 revolutions using abrasive paper S-11 instead of abrasive paper AA-400. (Haze = Td / Tt × 100, Td: scattered light transmittance, Tt: total light transmittance)

  (5) Hot water resistance: Appearance change and adhesion of the coating layer after the test piece was immersed in boiling water for 2 hours were evaluated.

  (6) Coefficient of variation: The coating material for coating was diluted 10-fold with 2-propanol, and evaluated by a dynamic light scattering method using a concentrated particle size analyzer FPAR-1000 manufactured by Otsuka Electronics Co., Ltd. The coefficient of variation was calculated by analyzing the obtained light scattering data by the Marquadt method using analysis software attached to the apparatus. (Coefficient of variation = 100 × (standard deviation / average particle size))

[Reference Example 1] (Preparation of paint for first layer)
A flask equipped with a reflux condenser and a stirrer and purged with nitrogen, 80.1 parts of methyl methacrylate (hereinafter abbreviated as MMA), 13 parts of 2-hydroxyethyl methacrylate (hereinafter abbreviated as HEMA), azobisisobutyronitrile 0.14 parts (hereinafter abbreviated as AIBN) and 200 parts of 1,2-dimethoxyethane were added, mixed and dissolved. Subsequently, it was made to react under stirring at 70 degreeC in nitrogen stream for 6 hours. The obtained reaction solution was added to n-hexane and purified by reprecipitation to obtain 80 parts of a copolymer (acrylic resin (I)) having a MMA / HEMA composition ratio of 90/10 (molar ratio). The copolymer had a hydroxyl value of 54.3 mgKOH / g and a weight average molecular weight of 100,000 in terms of polystyrene from GPC measurement (column; Shodex GPCA-804, eluent: THF). 8.9 parts of the acrylic resin (I) and 2.5 parts of 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole are added from 20 parts of methyl ethyl ketone, 30 parts of methyl isobutyl ketone and 30 parts of 2-propanol. Then, 1.1 parts of hexamethylene diisocyanate was added to this solution so that the isocyanate group was 1.5 equivalents relative to 1 equivalent of the hydroxy group of the acrylic resin (I) at 25 ° C. The coating for coating (I-1) was prepared by stirring for 5 minutes.

[Reference Example 2] (Preparation of paint for first layer)
A copolymer (acrylic resin) having an EMA / HEMA composition ratio of 90/10 (molar ratio) in the same manner as in Reference Example 1 except that 102.7 parts of ethyl methacrylate (hereinafter abbreviated as EMA), 13 parts of HEMA, and 0.18 part of AIBN are used. (II)) 100 parts were obtained. The copolymer had a hydroxyl value of 46.7 mgKOH / g and a weight average molecular weight of 90000 in terms of polystyrene. 7.7 parts of the acrylic resin (II) and 1.5 parts of 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole are mixed with 40 parts of methyl ethyl ketone, 20 parts of methyl isobutyl ketone, 24 parts of isopropanol, and 1 part. -Dissolve in a mixed solvent consisting of 3.2 parts of methoxy-2-propanol, and then add VESTANATB 1358/100 (Degussa) to this solution so that the isocyanate group is 1 equivalent to 1 equivalent of the hydroxy group of the acrylic resin (II). Japan Polyisocyanate Compound Precursor) 2.3 parts and 0.001 part of di-n-butyltin dilaurate were added and stirred at 25 ° C. for 5 minutes to prepare a coating material for coating (I-2).

[Example 1]
24 parts of acetic acid was added to 80 parts of water-dispersed colloidal silica dispersion (Cataloid SN-35, produced by Catalyst Kasei Kogyo Co., Ltd., solid content concentration: 30% by weight, average particle size: 18 nm), and the pH was adjusted to 2.6. . The dispersion was cooled to 10 ° C. and added to 127 parts of methyltrimethoxysilane under cooling in an ice water bath. Immediately after the start of the addition of methyltrimethoxysilane, the temperature of the mixture started to increase due to the heat of reaction. After 5 minutes from the start of the addition of methyltrimethoxysilane, the temperature rose to 50 ° C, and then the temperature of the mixture decreased gradually due to the cooling effect. . When the temperature of the mixture reached 40 ° C, the mixture was stirred for 4 hours at 40 ° C, and 0.5 parts of 45% choline methanol solution as a curing catalyst was mixed under ice water cooling. Then, 50 parts of 2-propanol was added as a diluting solvent to obtain a coating material (i) for second layer coating. When the average particle size of silica fine particles of the coating material for coating (i) and the coefficient of variation based on the particle size (100 × (standard deviation / average particle size)) were determined, the average particle size was 25.3 nm and the coefficient of variation was 21. .7. The coating material for coating (I-1) is applied to a transparent polycarbonate resin sheet having a thickness of 4 mm by dip coating so that the cured film thickness is 4 μm and thermally cured at 120 ° C. for 1 hour. i) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

[Example 2]
1 part of 1M hydrochloric acid is added to 100 parts of water-dispersed colloidal silica dispersion (Cataloid SN-35 manufactured by Catalytic Chemical Industry Co., Ltd., solid content concentration: 30% by weight, average particle size: 18 nm), and the mixture is stirred well. It was adjusted. The dispersion was cooled to 10 ° C., and a mixture of 146 parts of methyltrimethoxysilane and 2.5 parts of dimethyldimethoxysilane was added over 5 minutes while cooling in an ice water bath. Immediately after the addition of the silane mixture started, the temperature of the mixed solution started to increase due to the reaction heat, and after 5 minutes from the start of the addition, the temperature rose to 50 ° C. and then the temperature of the mixed solution gradually decreased due to the cooling effect. When the temperature of the mixed solution reached 25 ° C., this temperature was maintained and stirred at 25 ° C. for 8 hours. To this, 0.5 part of 45% choline methanol solution as a curing catalyst was cooled with ice water. To obtain a coating material for second layer coating (ii). From the dynamic light scattering measurement of the coating material for coating (ii), it was found that the average particle size of the silica fine particles was 26.2 nm and the coefficient of variation was 24.4. The coating material for coating (I-1) is applied to a transparent polycarbonate resin sheet having a thickness of 4 mm by dip coating so that the cured film thickness is 4 μm and thermally cured at 120 ° C. for 1 hour. Both sides of ii) were applied by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

[Example 3]
Add 15 parts of distilled water and 1 part of 1M hydrochloric acid to 60 parts of water-dispersed colloidal silica dispersion (Cataloid SN-35 manufactured by Catalytic Chemical Industry Co., Ltd., solid concentration 30% by weight, average particle size 18 nm) and stirred. PH was adjusted to 1.9. The dispersion was cooled to 10 ° C., and 142 parts of methyltrimethoxysilane was added over 3 minutes under cooling in an ice water bath. Immediately after the start of the addition of methyltrimethoxysilane, the temperature of the mixture started to increase due to the heat of reaction, and after 5 minutes from the start of the addition of methyltrimethoxysilane, the temperature rose to 60 ° C and then the temperature of the mixture gradually decreased due to the effect of cooling. . When the temperature of the mixed solution reached 40 ° C., the mixture was stirred for 6 hours at 40 ° C., and 2 parts of sodium acetate as a curing catalyst was mixed under cooling with ice water, and 50 parts of 2-propanol was mixed. The coating material for coating (iii) for the second layer was prepared by diluting with the above. From the dynamic light scattering measurement of the coating material for coating (iii), it was found that the average particle diameter of the silica fine particles was 33.9 nm and the coefficient of variation was 34.8. A coating material for coating (1-2) is applied to a transparent polycarbonate resin sheet having a thickness of 4 mm by dip coating so that the cured film thickness is 4 μm and thermally cured at 120 ° C. for 1 hour. iii) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

[Example 4]
24 parts of acetic acid was added to 80 parts of a water-dispersed colloidal silica dispersion (Snowtex 30 manufactured by Nissan Chemical Industries, Ltd., solid content concentration 30% by weight, average particle size 20 nm) and stirred to adjust the pH to 2.6. The dispersion was cooled to 10 ° C., and a mixture of 140 parts of methyltrimethoxysilane and 3 parts of dimethyldimethoxysilane was added over 5 minutes while cooling in an ice water bath. Immediately after the start of addition of the silane mixture, the temperature of the mixture started to increase due to the reaction heat, and after 5 minutes from the start of addition, the temperature rose to 60 ° C., and then the temperature of the mixture gradually decreased due to the cooling effect. When the temperature of the mixed liquid reached 25 ° C., the mixture was stirred for 12 hours at 25 ° C., and 2 parts of sodium acetate as a curing catalyst was mixed under ice water cooling as a curing catalyst. A two-layer coating paint (iv) was obtained. From the dynamic light scattering measurement of the coating material for coating (iv), it was found that the average particle diameter of the silica fine particles was 33.9 nm and the coefficient of variation was 34.8. A coating material for coating (1-2) is applied to a transparent polycarbonate resin sheet having a thickness of 4 mm by dip coating so that the cured film thickness is 4 μm and thermally cured at 120 ° C. for 1 hour. iv) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.
The obtained sheet was fitted into a sunroof window frame of an automobile and used for one year. However, it was hardly damaged and could be suitably used as a glass for an automobile sunroof.

[Comparative Example 1]
24 parts of acetic acid was added to 80 parts of water-dispersed colloidal silica dispersion (Cataloid SN-35, produced by Catalyst Kasei Kogyo Co., Ltd., solid content concentration: 30% by weight, average particle size: 18 nm), and the pH was adjusted to 2.6. . The dispersion was cooled to 10 ° C. and added to 127 parts of methyltrimethoxysilane under cooling in an ice water bath. Immediately after the start of the addition of methyltrimethoxysilane, the temperature of the mixture started to increase due to the heat of reaction. After 5 minutes from the start of the addition of methyltrimethoxysilane, the temperature rose to 50 ° C, and then the temperature of the mixture decreased gradually due to the cooling effect. . When the temperature of the mixed liquid reached 25 ° C., the mixture was stirred at 25 ° C. for 4 hours so as to maintain this temperature. To this, 2 parts of sodium acetate as a curing catalyst was mixed under ice water cooling, and 2 parts as a diluting solvent was mixed. -50 parts of propanol was added to obtain a coating material for second layer coating (v). From the dynamic light scattering measurement of the coating material for coating (v), it was found that the average particle size of the silica fine particles was 24.2 nm and the coefficient of variation was 17.4. The coating material for coating (I-1) is applied to a transparent polycarbonate resin sheet having a thickness of 4 μm by dip coating so as to have a cured film thickness of 4 μm and thermally cured at 120 ° C. for 1 hour. v) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

[Comparative Example 2]
Add 1 part of 1M hydrochloric acid to 80 parts of water-dispersed colloidal silica dispersion (Cataloid SN-35, solid content concentration 30% by weight, average particle diameter 18 nm, manufactured by Catalyst Chemical Industry Co., Ltd.) and stir well to adjust the pH to 1.9. It was adjusted. The dispersion was cooled to 10 ° C., and a mixture of 135 parts of methyltrimethoxysilane and 5 parts of dimethyldimethoxysilane was added over 3 minutes while cooling in an ice water bath. Immediately after the addition of the silane mixture started, the temperature of the mixed solution started to increase due to the reaction heat, and after 5 minutes from the start of the addition, the temperature rose to 50 ° C. and then the temperature of the mixed solution gradually decreased due to the cooling effect. When the temperature of the mixed solution reached 40 ° C., the mixture was stirred at 40 ° C. for 12 hours so as to maintain this temperature. To this, 2 parts of sodium acetate as a curing catalyst was mixed under cooling with ice water, and 2 -Diluted with 50 parts of propanol to give a coating for the second layer (vi). From the dynamic light scattering measurement of the coating material for coating (vi), it was found that the average particle diameter of the silica fine particles was 101.0 nm and the coefficient of variation was 99.2. The coating material for coating (I-1) is applied to a transparent polycarbonate resin sheet having a thickness of 4 μm by dip coating so as to have a cured film thickness of 4 μm and thermally cured at 120 ° C. for 1 hour. Vi) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

[Comparative Example 3]
To 80 parts of water-dispersed colloidal silica dispersion (ST-XL, manufactured by Nissan Chemical Industries, Ltd., solid content concentration 40% by weight, average particle size 50 nm), 28 parts of distilled water and 0.5 part of 1M hydrochloric acid are added and stirred. And adjusted to pH 1.9. The dispersion was cooled to 10 ° C., and 171 parts of methyltrimethoxysilane was added over 5 minutes while cooling in an ice-water bath. Immediately after the start of the addition of methyltrimethoxysilane, the temperature of the mixture started to increase due to the heat of reaction, and after 5 minutes from the start of the addition of methyltrimethoxysilane, the temperature rose to 60 ° C and then the temperature of the mixture gradually decreased due to the effect of cooling. . When the temperature of the mixed liquid reached 25 ° C., the mixture was stirred for 8 hours at 25 ° C., and 2 parts of sodium acetate as a curing catalyst was mixed under cooling with ice water, and 50 parts of 2-propanol was mixed. The coating material for the second layer coating (vii) was prepared. From the dynamic light scattering measurement of the coating material for coating (vii), it was found that the average particle diameter of silica fine particles was 90.3 nm and the coefficient of variation was 33.2. A coating material for coating (1-2) is applied to a transparent polycarbonate resin sheet having a thickness of 4 mm by dip coating so that the cured film thickness is 4 μm and thermally cured at 120 ° C. for 1 hour. Vii) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

[Comparative Example 4]
0.8 parts of 1M hydrochloric acid was added to 60 parts of water-dispersed colloidal silica dispersion (ST-XS, manufactured by Nissan Chemical Industries, Ltd., solid content concentration 20% by weight, average particle size 5 nm), and stirred to a pH of 1.9. Adjusted. The dispersion was cooled to 10 ° C., and 45 parts of methyltrimethoxysilane and 17 parts of dimethyldimethoxysilane were added over 5 minutes while cooling in an ice water bath. Immediately after the start of the addition of methyltrimethoxysilane, the temperature of the mixture started to increase due to the heat of reaction, and after 5 minutes from the start of the addition of methyltrimethoxysilane, the temperature rose to 60 ° C and then the temperature of the mixture gradually decreased due to the effect of cooling. . When the temperature of the mixed liquid reached 40 ° C., the mixture was stirred for 4 hours at 40 ° C., and 2 parts of sodium acetate as a curing catalyst was mixed under cooling with ice water, and 50 parts of 2-propanol was mixed. The coating material for the second layer coating (viii) was prepared. As a result of the dynamic light scattering measurement of the coating material for coating (viii), the average particle diameter of the silica fine particles was 213.4 nm, and the variation coefficient was 183.8. A coating material for coating (1-2) is applied to a transparent polycarbonate resin sheet having a thickness of 4 mm by dip coating so that the cured film thickness is 4 μm and thermally cured at 120 ° C. for 1 hour. viii) was coated on both sides by dip coating so as to have a cured film thickness of 5 μm, and thermally cured at 120 ° C. for 1 hour to obtain a transparent polycarbonate resin sheet having a coating layer. The results of evaluating the polycarbonate resin sheet having the obtained coating layer are shown in Table 1.

Claims (8)

(A) Organosiloxane resin coating containing silica fine particles obtained by condensation reaction of colloidal silica (component a) and (B) hydrolyzate of alkoxysilane represented by the following formula (1) or its condensate (component b) In preparing the a component, the average particle size of the silica fine particles is 10 to 70 nm, and the coefficient of variation {100 × (standard deviation / average particle size)} based on the particle size is 20 to 40%. A method for preparing an organosiloxane resin paint, which comprises reacting with component b.

(However, in the formula, each of R ¹ and R ² is one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, or a methacryloxy group, an amino group, a glycidoxy group, and a 3,4-epoxycyclohexyl group. An alkyl group having 1 to 3 carbon atoms substituted with a group, R ³ is an alkyl group having 1 to 4 carbon atoms, m and n are each an integer of 0, 1 or 2, and m + n is (It is an integer of 0, 1, 2) The colloidal silica (component a) is 10 to 60% by weight, and the hydrolyzate of alkoxysilane or the condensate thereof (component b) is converted into R ¹ _m R ² _n SiO _{(4-mn) / 2.} The method for preparing an organosiloxane resin paint according to claim 1, wherein the content is 40 to 90% by weight (the total amount of the component a and the component b is 100% by weight).   The method for preparing an organosiloxane resin coating material according to claim 1, wherein the colloidal silica (component a) has a particle size of 5 to 50 nm.   Furthermore, the preparation method of the organosiloxane resin coating material of Claim 1 which contains 0.01-10 weight part of (C) hardening catalyst (c component) with respect to 100 weight part of total amounts of a component and b component.   The method for preparing an organosiloxane resin paint according to claim 1, wherein the organosiloxane resin paint has a solid content of 10 to 70% by weight.   2. The method for preparing an organosiloxane resin paint according to claim 1, wherein at least 50% by weight or more of the solvent is an alcohol having 1 to 4 carbon atoms as a solvent for the organosiloxane resin paint. (A) Organosiloxane resin coating containing silica fine particles obtained by condensation reaction of colloidal silica (component a) and (B) hydrolyzate of alkoxysilane represented by the following formula (1) or its condensate (component b) In which the average particle size of the silica fine particles is 10 to 70 nm and the coefficient of variation {100 × (standard deviation / average particle size)} based on the particle size is 20 to 40% Resin paint.

(However, in the formula, each of R ¹ and R ² is one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a vinyl group, or a methacryloxy group, an amino group, a glycidoxy group, and a 3,4-epoxycyclohexyl group. An alkyl group having 1 to 3 carbon atoms substituted with a group, R ³ is an alkyl group having 1 to 4 carbon atoms, m and n are each an integer of 0, 1 or 2, and m + n is (It is an integer of 0, 1, 2) On at least one surface of the polycarbonate substrate, as a first layer, at least 50% by weight of the coating resin is an acrylic resin, and the acrylic resin contains 50 mol% or more of a repeating unit represented by the following formula (2). A polycarbonate resin having a surface protected by laminating a coating film resin, which is an acrylic resin, and then laminating a coating film layer obtained by thermosetting the organosiloxane resin paint according to claim 6 as a second layer thereon. Molded body.

(However, in the formula, R ⁴ is an alkyl group having 1 to ⁴ carbon atoms.)