JP5888779B2 - Method for producing light reflecting coating film - Google Patents

Description

The present invention relates to an organopolysiloxane mixture composition suitable as a main component of a coating material for forming a coating film on the surface of a substrate , and particularly to a light-reflective coating film using the organopolysiloxane mixture composition. It relates to a manufacturing method .

Conventionally, as a coating paint mainly composed of an organopolysiloxane, in Patent Document 1, an organoalkoxysilane represented by the general formula R ¹ _m Si (OR ² ) _4-m is hydrolyzed, further condensed, and weight averaged. Those containing an organopolysiloxane having a molecular weight of, for example, 800 to 4,000 have been proposed.

  However, in Patent Document 1, the organopolysiloxane grows into a spherical shape having a molecular weight distribution with a single peak, and a coating film is formed using a coating paint mainly composed of such an organopolysiloxane. Then, unevenness occurs in the filling of the organopolysiloxane, cracks occur due to the difference in density distribution in the micro region and the resulting stress concentration, and in the worst case, the coating film may be peeled off.

JP-A-10-195381

The present invention is all SANYO been made in view of the problems described above, an object using an organopolysiloxane mixture composition, not easily separable good coating film, that particularly to provide a method for manufacturing a light-reflecting coating And

The production method of the light reflecting coating film of the present invention is represented by the formula 1: R ¹ _m Si (OR ² ) _4-m (wherein R ¹ is an organic group having 1 to 8 carbon atoms and R ² is 1 to 1 carbon atoms). 5 is an organopolysiloxane obtained by hydrolysis and condensation of an organoalkoxysilane represented by (5), m is an integer of 0 to 2, and has different weight average molecular weights. A coating paint with an inorganic filler added is applied to an organopolysiloxane mixture composition obtained by mixing and then heat-cured to form a light reflecting coating film .

The organopolysiloxane mixture composition used in the present invention has the weight average molecular weight of the organopolysiloxane having the largest weight average molecular weight as Mw ¹ and the weight average molecular weight of the organopolysiloxane having the second largest weight average molecular weight. When Mw ² is satisfied, Mw ² <0.5 Mw ¹ and in the mixing ratio, the weight of the organopolysiloxane contained in the organopolysiloxane having the maximum weight average molecular weight is defined as W ^1, and other organopolysiloxanes when the total weight of the ^{W 2,} it is preferable that satisfy W 2 <0.5W ^1. The Mw ² is preferably 800 or more.

  Here, the organopolysiloxane refers to a group of organopolysiloxanes belonging to one molecular weight distribution separated when the molecular weight distribution of the organopolysiloxane is peak-separated by baseline separation. This will be described in detail with reference to the drawings. FIG. 1 shows an example of the molecular weight distribution of an organopolysiloxane analyzed by gel permeation chromatography. The horizontal axis is the molecular weight, and the polymer becomes higher on the right side. On the other hand, the vertical axis represents the intensity of analysis, which is an arbitrary unit. When this is separated using a molecular weight region of zero intensity as a separation boundary, that is, peak separation is performed by zero line separation, the molecular weight distribution in FIG. 1 is classified into four molecular weight distribution regions. The molecular weight distribution region having the first single peak from the left in FIG. 1 is the most ideal distribution shape, can be easily separated from other molecular weight distribution regions, and can be classified as organopolysiloxanes A. it can. The second molecular weight distribution region from the left has a single peak, but has a gentle distribution on the low molecule side. This can also be tentatively classified as organopolysiloxanes B. The third molecular weight distribution region from the left clearly has two peaks, but the number of peaks is irrelevant to the classification criteria of organopolysiloxanes, so the third molecular weight distribution region from the left is As it is, it is temporarily classified as organopolysiloxanes C. Moreover, although the several molecular weight distribution area | region from the left can also confirm a some peak, it is provisionally classified as organopolysiloxane D as it is.

  In the case of FIG. 1, the organopolysiloxane having the largest weight average molecular weight refers to the organopolysiloxane D, and the organopolysiloxane having the second largest weight average molecular weight refers to the organopolysiloxane C. The other organopolysiloxane is an organopolysiloxane excluding the organopolysiloxane contained in the organopolysiloxanes D.

The organopolysiloxane mixture composition used in the present invention has a mixture of at least two types of organopolysiloxanes having different weight average molecular weights. Since the organic polysiloxane having a small molecular weight is filled with the resin to increase the density, local high tensile stress caused by shrinkage during heat treatment curing can be relieved. As a result, the occurrence of cracks during curing can be suppressed, and the coating film having high yield and high reliability can be obtained . In particular, the light reflecting coating film of the present invention obtained by adding an inorganic filler has a yield. It is high, and reliability also have high.

An example of the molecular weight distribution of organopolysiloxane analyzed by gel permeation chromatography is shown.

The organoalkoxysilane used in the present invention is represented by the formula 1: R ¹ _m Si (OR ² ) _4-m (wherein R ¹ is an organic group having 1 to 8 carbon atoms, and R ² is an alkyl having 1 to 5 carbon atoms. Group, m is an integer of 0-2.

As the “C1-C8 organic group” of the substituent R ¹ of Formula 1, a linear alkyl group such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, hexyl, heptyl, octyl, etc .; branched alkyl groups such as iso-propyl, iso-butyl, sec-butyl, tert-butyl, iso-pentyl, tert-pentyl, neo-pentyl, methylhexyl, dimethylhexyl, ethylhexyl, methylheptyl; vinyl, allyl, iso-propenyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl and the like; linear alkenyl or alkynyl groups such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, butazinyl, pentazinyl, hexazinyl, heptazinyl, octadinyl; methyl Pentenyl , Ethylpentenyl, dimethylpentenyl, methylhexenyl, ethylhexenyl, dimethylhexenyl, methylheptenyl, etc .; branched alkenyl or alkynyl groups such as methylpentynyl, ethylpentynyl, dimethylpentynyl, methylhexynyl, ethylhexynyl, dimethylhexynyl, methylheptynyl, etc. Aryl groups such as phenyl, tolyl and xylyl; and substituted linear alkyl groups such as γ-chloropropyl, γ-methacryloyloxypropyl and γ-mercaptopropyl. Of these, methyl, ethyl, n-propyl, iso-propyl, n-butyl, vinyl, phenyl, γ-methacryloyloxypropyl, γ-mercaptopropyl and the like are preferable.

Examples of the “alkyl group having 1 to 5 carbon atoms” of the substituent R ² of Formula 1 include linear alkyl groups such as methyl, ethyl, n-propyl, n-butyl, n-pentyl; iso-propyl, iso- Examples thereof include branched alkyl groups such as butyl, sec-butyl, tert-butyl, iso-pentyl, tert-pentyl and neo-pentyl.

  As specific examples of organoalkoxysilane, when m is 0, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, etc .; Trimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltriisopropoxysilane, methyltri-n-butoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltri Ethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc .; when m is 2, dimethyl Examples include dimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. These organoalkoxysilanes can be used alone or in combination of two or more, and among them, a group consisting of tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane It is preferable that at least one selected from

  The organoalkoxysilane used in the present invention is hydrolyzed with water in the presence of an organic acid such as formic acid, acetic acid and oxalic acid or an inorganic acid such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid and boric acid. Condensed. In using the catalyst, a method of generating the catalyst by chemical change may be used. Examples of such a method include a method of adding diphosphorus pentoxide with water and a method of adding boron oxide with water. . The amount of water to be used is 0.8 to 3 mol, preferably 1 to 1.5 mol, per 1 mol of the alkoxy group. When the amount of water is less than 0.8 mol, many unhydrolyzed alkoxy groups remain and become alkoxy-terminated organopolysiloxane, which is not preferable because the storage stability is good but the adhesion and curability are poor. On the other hand, when the amount of water exceeds 3 mol, a large amount of active silanol groups remains, so that the curability and adhesion are improved, but it is not preferable because it tends to thicken and gel.

The organopolysiloxane mixed composition of the present invention is formed by mixing at least two types of organopolysiloxanes having different weight average molecular weights, preferably, the weight average of the organopolysiloxanes having the largest weight average molecular weight. When the molecular weight is Mw ¹ and the weight average molecular weight of the organopolysiloxane having the second largest weight average molecular weight is Mw ² , Mw ² <0.5 Mw ¹ is satisfied, and the weight average molecular weight in the mixing ratio When the weight of the organopolysiloxane contained in the largest organopolysiloxane is W ¹ and the total weight of the other organopolysiloxane is W ² , mixing is performed so that W ² <0.5W ¹ is satisfied.

  With such a composition and mixing ratio, a coating film precursor filled with an organopolysiloxane can be formed efficiently. When this precursor is formed on a substrate and cured by heat treatment, the coating film precursor has a high density. Thus, it is possible to obtain a coating film in which cracks are hardly generated.

Organopolysiloxanes having different weight average molecular weights can be obtained, for example, by mixing together organopolysiloxanes obtained through different processes, but a process in which organopolysiloxanes having different weight average molecular weights are mixed. If so, the method does not matter. Incidentally, if they meet the above condition is not particularly limited to the scope of the weight average molecular weight, Mw ¹ is the weight average molecular weight by gel permeation chromatography and the standard polyethylene oxide 1,500～300,000 Is preferred.

Various inorganic fillers can be added to the organopolysiloxane mixture composition of the present invention as necessary. As such an inorganic filler, AlN, Al ₂ O ₃ , Al (OH) ₃ , cBN, hBN, BaSO ₄ , CaCO ₃ , MgO, Mg (OH) ₂ , ZrO ₂ , ZrB ₂ , TiO ₂ , TiB ₂ TiN, ZnO, ZnS, (PbCO ₃ ) ₂ Pb (OH) ₂ , SiO ₂ , SiC, Si ₃ N ₄ , graphite, diamond and the like. By adding these inorganic fillers, it is possible to obtain a filler-containing organopolysiloxane that has a function expressed by the inorganic filler and can provide a highly reliable coating film in which cracks are suppressed. For example, a rust preventive film, an electrical insulating film, a conductive film, a far infrared radiation film, a far infrared absorption film, a heat conduction film, a light reflection film, etc. are formed by adding one or more suitable inorganic fillers. Therefore, it is possible to obtain a filler-containing organopolysiloxane that can be suitably used as a coating material. Furthermore, various conventionally known additives such as various surfactants, silane coupling agents, and dyes can be added to the coating paint (filler-containing organopolysiloxane) of the present invention.

  The coating paint of the present invention comprises the organopolysiloxane mixture composition or filler-containing organopolysiloxane of the present invention. In the coating paint of the present invention, in addition to the above-mentioned organopolysiloxane mixture composition or filler-containing organopolysiloxane, a solvent can be appropriately used for the purpose of viscosity adjustment, dilution and the like. Examples of the solvent include alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol and sec-butanol; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethyl acetate and acetic acid. Examples include ester solvents such as butyl and acetic acid diethylene glycol mono-n-butyl ether; polyhydric alcohol solvents such as ethylene glycol, methyl cellosolve, ethyl cellosolve, and butyl cellosolve; aromatic solvents such as benzene, toluene, and xylene. These solvents can be used in combination of one or more.

  The amount of these solvents is appropriately determined according to the purpose such as viscosity adjustment and dilution, and is not particularly limited. However, it is usually preferred that the total solid content in the composition is adjusted to 1 to 60% by mass, preferably 5 to 40% by mass. When the amount of the solvent is within the above range, a coating paint in which the durability of the coating film such as chemical resistance and moisture resistance and the storage stability of the composition are balanced can be obtained.

  The coating paint thus obtained is applied to the surface of various materials (coating bodies) by a known method, that is, a dipping method, a casting method, a spinner method, a spray method, a bar coating method, etc. A desired coating body can be obtained by heat-curing. Examples of the material to be coated include metal, ceramic, cement, glass, plastic, paper, fiber, and wood. In addition, according to the coating paint of the present invention, the coating film can be cured under a relatively mild heat treatment condition of about 80 to 250 ° C. for 5 to 60 minutes, and cracks and peeling may occur during the curing. In other words, it is possible to obtain a coating body having a relatively thick coating film having high toughness and high adhesion.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

<Example 1>
As solution A, 100 parts of methyltriethoxysilane was mixed with 2 parts of acetic acid and 30.3 parts of water (equivalent to 3 moles of water with respect to 1 mole of methyltriethoxysilane), and stirred for 1 hour at room temperature to add water. After decomposing, a condensation reaction treatment was performed at 70 ° C. for 24 hours in an autoclave. When the obtained solution A was subjected to gel permeation chromatography analysis, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 10,500. As solution B, 100 parts of methyltriethoxysilane was mixed with 2 parts of acetic acid and 30.3 parts of water, stirred for 1 hour at room temperature, and then subjected to a condensation reaction treatment at 70 ° C. for 4 hours in an autoclave. . When the obtained solution B was subjected to gel permeation chromatography analysis, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 1,200. The resulting organopolysiloxane in solution A and the organopolysiloxane in solution B were mixed at a weight ratio of 7: 3 to obtain the desired organopolysiloxane mixture composition. When the obtained organopolysiloxane mixture composition was subjected to gel permeation chromatography analysis, it was confirmed to be composed of two organopolysiloxanes.

<Example 2>
As solution C, 100 parts of methyltriethoxysilane was mixed with 2 parts of acetic acid and 30.3 parts of water, stirred at room temperature for 1 hour for hydrolysis, and then subjected to a condensation reaction at 70 ° C. for 24 hours in an autoclave. Processed. When the obtained solution C was subjected to gel permeation chromatography analysis, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 10,500. As solution D, 100 parts of methyltriethoxysilane was mixed with 2 parts of acetic acid and 30.3 parts of water, stirred for 1 hour at room temperature, and then subjected to a condensation reaction treatment at 70 ° C. for 4 hours in an autoclave. . When the obtained solution D was analyzed by gel permeation chromatography, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 1,200. Further, as solution E, 100 parts of methyltriethoxysilane was mixed with 2 parts of acetic acid and 30.3 parts of water, stirred for 1 hour at room temperature, and then subjected to a condensation reaction treatment at 70 ° C. for 1 hour in an autoclave. . When the obtained solution E was subjected to gel permeation chromatography analysis, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 800. The resulting organopolysiloxane in solution C, organopolysiloxane in solution D, and organopolysiloxane in solution E were mixed so that the weight ratio was 7: 2.5: 0.5, and the desired organo A polysiloxane mixture composition was obtained. When the obtained organopolysiloxane mixture composition was subjected to gel permeation chromatography analysis, it was confirmed to be composed of three organopolysiloxanes.

<Example 3>
As solution F, 100 parts of phenyltriethoxysilane was mixed with 2 parts of acetic acid and 22.5 parts of water (equivalent to 3 moles of water with respect to 1 mole of phenyltriethoxysilane), and stirred for 1 hour at room temperature to add water. After decomposing, a condensation reaction treatment was performed at 70 ° C. for 24 hours in an autoclave. When the obtained solution F was analyzed by gel permeation chromatography, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 25,200. Further, as solution G, 2 parts of acetic acid and 31.1 parts of water (4: 1 mixture of methyltriethoxysilane and tetraethoxysilane 1 with respect to 100 parts of 4: 1 mixture of methyltriethoxysilane and tetraethoxysilane 1 (Equivalent to 3.2 moles of water with respect to moles) was mixed, stirred for 1 hour at room temperature, and then subjected to a condensation reaction treatment at 70 ° C for 4 hours in an autoclave. When the obtained solution G was analyzed by gel permeation chromatography, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 1,200. As solution H, 100 parts of tetraethoxysilane was mixed with 2 parts of acetic acid and 34.6 parts of water (equivalent to 4 moles of water with respect to 1 mole of tetraethoxysilane), stirred for 1 hour at room temperature, and then autoclave. The condensation reaction treatment was performed at 70 ° C. for 1 hour. When the obtained solution H was subjected to gel permeation chromatography analysis, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 800. These organopolysiloxanes in solution F, organopolysiloxane in solution G and organopolysiloxane in solution H were mixed so that the weight ratio was 7: 2.5: 0.5, and the desired organo A polysiloxane mixture composition was obtained. When the obtained organopolysiloxane mixture composition was subjected to gel permeation chromatography analysis, it was confirmed to be composed of three organopolysiloxanes.

<Example 4>
As Example 4, the organopolysiloxane in the solution A produced in Example 1 and the organopolysiloxane in the solution B were mixed so that the weight ratio was 3: 7. A body solution was obtained. When the obtained organopolysiloxane mixture composition was subjected to gel permeation chromatography analysis, it was confirmed to be composed of two organopolysiloxanes.

<Example 5>
As solution I, 100 parts of methyltriethoxysilane was mixed with 2 parts of acetic acid and 30.3 parts of water (equivalent to 3 moles of water with respect to 1 mole of methyltriethoxysilane), and stirred for 1 hour at room temperature to add water. After decomposing, a condensation reaction treatment was performed at 70 ° C. for 18 hours in an autoclave. When the obtained solution I was subjected to gel permeation chromatography analysis, it was composed of one organopolysiloxane, and the weight average molecular weight of the organopolysiloxane was 8,600. Using this solution I, solution A and solution B produced in the above example, the weight ratio of the organopolysiloxane in solution A to the organopolysiloxane in solution B and the organopolysiloxane in solution I was 5: 2. 5: 2.5 to obtain the desired organopolysiloxane mixture composition. Gel permeation chromatography analysis of the resulting organopolysiloxane mixture composition revealed that the molecular weight distribution of solution A and solution I overlapped to form one organopolysiloxane, and the resulting organopolysiloxane The mixture composition was confirmed to consist of two organopolysiloxanes. The weight average molecular weight of organopolysiloxanes having a high molecular weight was 9,900, and the weight average molecular weight of organopolysiloxanes having a low molecular weight was 1,200.

<Comparative Example 1>
As Comparative Example 1, the solution A produced in Example 1 was used as an organopolysiloxane solution of Comparative Example 1.

<Comparative Example 2>
As Comparative Example 2, the solution B produced in Example 2 was used as an organopolysiloxane solution of Comparative Example 2.

  The properties of the solutions A to I prepared in Examples 1 to 5 are summarized in Table 1.

Spin the organopolysiloxane mixture composition solutions of Examples 1 to 5 and the organopolysiloxane solutions of Comparative Examples 1 and 2 so that the coating amount is 3 to 8 g / m ² (wet weight) on an aluminum substrate. Coated and dried at 50 ° C. for 5 minutes. Further, the film was dried at 120 ° C. for 10 minutes, and finally heat-treated and cured at 250 ° C. for 30 minutes to form a coating film on the aluminum substrate. When visual observation and microscopic observation were performed about the obtained coating film, as shown in Table 2, although a crack and peeling were not seen in the coating film formed using the solution of Examples 1-5, it is a comparative example Cracks occurred in any of the coating films formed using the solutions 1 and 2.

In addition, about the coating film formed using the solution of Examples 1-5 in which a crack and peeling were not seen, when the bending test was implemented with the aluminum substrate in which the coating film was formed on the aluminum substrate, Example 1 was carried out. Although the coating film formed using the solutions of -3 and Example 5 was able to withstand 90 ° bending with a radius of curvature of 10 mm, the coating film formed using the solution of Example 4 was cracked. did. This is the relationship between the weight W ¹ of the organopolysiloxane contained in the organopolysiloxane having the largest weight average molecular weight in the solution and the total weight W ² of the other organopolysiloxanes in the solution of Example 4. However, it is estimated that W ² <0.5W ¹ is not satisfied.

  Moreover, as a result of measuring the specific gravity of the coating film of Examples 1, 2, 4, and 5 and Comparative Examples 1-2, as shown in Table 2, the organopolysiloxane mixture composition of Examples 1, 2, 4, and 5 The specific gravity of the coating film manufactured using the physical solution is larger than the specific gravity of the coating film manufactured using the organopolysiloxane solution of Comparative Example 1 and Comparative Example 2, and it was confirmed that the density was improved. It was. In particular, it was confirmed that the coating film produced using the organopolysiloxane mixture composition solution of Example 1, Example 2 and Example 5 had a specific gravity exceeding 1.300 and the density was further improved. It was done.

<Example 6>
In Example 6, 15.3 parts of 1% aqueous ammonia (corresponding to 1.5 moles of water per mole of methyltriethoxysilane) was mixed with 100 parts of methyltriethoxysilane, and stirred at room temperature for 1 hour. After hydrolysis, a condensation reaction treatment was performed at 70 ° C. for 24 hours in an autoclave. Thereafter, 5 parts of acetic acid and 15.2 parts of water were further added, and a condensation reaction treatment at 70 ° C. for 4 hours was performed in an autoclave. When the obtained solution was subjected to gel permeation chromatography analysis, two organopolysiloxanes capable of baseline separation were confirmed. The weight average molecular weight of the organopolysiloxanes having a large weight average molecular weight was 15,500. The weight average molecular weight of organopolysiloxanes having a small weight average molecular weight was 2,200. Further, when the weight ratio of the organopolysiloxane in the solution was calculated from the molecular weight distribution, the weight of the organopolysiloxane having a large weight average molecular weight: the weight of the organopolysiloxane having a small weight average molecular weight was 76:24.

The obtained organopolysiloxane solution was spin-coated on an aluminum substrate so that the coating amount was 3 to 8 g / m ² (wet weight), and dried at 50 ° C. for 5 minutes. Further, the film was dried at 120 ° C. for 10 minutes, and finally heat-treated and cured at 250 ° C. for 30 minutes to form a coating film on the aluminum substrate. When the obtained coating film was visually observed and observed with a microscope, it was confirmed that no crack was present and that the film could withstand 90 ° bending with a radius of curvature of 10 mm.

<Example 7>
As Example 7, 300 parts of Al ₂ O ₃ powder was added to the organopolysiloxane solution of Example 1 corresponding to 100 parts by weight of the organopolysiloxane solution of Example 1 after heat treatment and solidified, and the mixture was stirred. The obtained paint was spin-coated on a copper substrate so that the coating amount was 3 to 8 g / m ² (wet weight), and dried at 50 ° C. for 5 minutes. After further drying at 120 ° C. for 10 minutes, heat treatment curing was finally performed at 250 ° C. for 30 minutes to obtain a coated body having a coating film formed on a copper substrate.

The obtained coating body was formed with a crack-free coating film in which Al ₂ O ₃ particles as inorganic filler were dispersed in the organopolysiloxane heat-treated cured body, and the diffuse reflectance of the formed coating film was measured. However, it was confirmed that a coating film having an average reflectance of 88% and a high reflectance was obtained within a visible light range of wavelengths from 380 nm to 780 nm. Further, it was confirmed that the formed coating film had no cracks and that the obtained coating body could withstand 90 ° bending with a radius of curvature of 10 mm. The coating film of Example 1 was transparent, and it was easily assumed that the reflectance was extremely low.

  Thus, it was confirmed that by adding the inorganic filler to the organopolysiloxane mixture composition, it is possible to obtain a highly reliable coating film having the functions expressed by the inorganic filler and suppressing the occurrence of cracks. It was.

  The organopolysiloxane mixture composition of the present invention can be used as a heat-resistant film, a raw material for spinning, a raw material for capacitors, a thermal conductive grease, and a sealing agent in addition to coating paints.

Claims (3)

Formula _^1: R 1 in _{^{m Si (OR 2) 4-}} m ( wherein 1, ^{R 1} is an organic group having 1 to 8 carbon atoms, ^{R 2} is an alkyl group of 1 to 5 carbon atoms, m is integer of 0 to 2 The organopolysiloxane mixture composition obtained by hydrolyzing and condensing the organoalkoxysilane represented by the formula (1) and comprising a mixture of at least two organopolysiloxanes having different weight average molecular weights. The manufacturing method of the light reflection coating film which apply | coats the coating paint which added the inorganic filler to and heat-hardens after that, and uses it as a light reflection coating film . In the organopolysiloxane mixture composition, the weight average molecular weight of the organopolysiloxane having the largest weight average molecular weight is Mw ¹ , and the weight average molecular weight of the organopolysiloxane having the second largest weight average molecular weight is Mw ² . When Mw ² <0.5 Mw ¹ and the mixing ratio thereof, the weight of the organopolysiloxane contained in the organopolysiloxane having the maximum weight average molecular weight is W ^1, and the total weight of the other organopolysiloxanes the when the ^{W 2, W 2} <method of manufacturing a light-reflecting coating according to claim 1 that meets the 0.5 W ^1. The method for producing a light reflecting coating film according to claim 2, wherein the Mw ² is 800 or more .

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