JPH0429709B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a dust-proof coating film-forming material, and more particularly to a room-temperature-curable coating film-forming material capable of forming a coating film with excellent dustproof properties on the surface of a silicone elastomer. Various types of polyorganosiloxane compositions that cure at room temperature and consist of rubber-like elastic bodies are known. For example, a polydiorganosiloxane whose both ends are blocked with silanol groups is hydrolyzed with acetoxy groups, alkoxy groups, dialkylketoxime groups, dialkylamino groups, dialkylaminoxy groups, N-methylamide groups, etc. that are bonded to silicon atoms. Polyorganosiloxane compositions using organosilicon compounds having such groups as crosslinking agents are widely used in the construction industry, automobiles, electrical equipment, and other industries. In the construction industry, this composition is collectively referred to as silicone sealant, and is widely used for waterproof sealing of building wall materials such as concrete and aluminum plates, for fixing glass to sash, and for adhering glass to glass. There is. Silicone sealants have particularly excellent weather resistance, durability, heat resistance, and cold resistance, their physical properties do not change much due to temperature, they do not deteriorate due to ozone or ultraviolet rays, and they have good workability during installation, so they are used in high-rise buildings and other applications. Demand is increasing. In addition, in recent years, polyorganosiloxane with this type of crosslinking mechanism has been applied to roofs and walls to form a silicone elastic layer with excellent waterproof and weather resistance, and its use as a coating material has begun in recent years. However, although such silicone elastomers have the excellent properties mentioned above, they remain slightly sticky after the curing reaction, and because their main component, polydiorganosiloxane, is a derivative, they are difficult to remove dust from. Easy to absorb. In particular, when non-reactive polydiorganosiloxane is added to obtain a flexible silicone elastomer while maintaining workability, the polydiorganosiloxane that does not participate in such crosslinking oozes out from the inside of the elastomer to the surface. In order to cover the dust and make the dust water repellent, the dust is not washed away by rainwater, and the appearance is seriously spoiled due to staining. Such silicone elastomers have problems in maintaining the appearance required as building materials, and are subject to restrictions in use. In addition, there are many uses for industrial materials other than construction where dust adhesion affects the appearance and usage characteristics. Therefore, the establishment of a technology for preventing dust from adhering to the surface of silicone elastic bodies has been desired by various industries including the construction industry. As a method for preventing dust from adhering to the surface of a silicone elastic body, there is a method described in JP-A-57-1627631. This method is based on the idea of covering the surface of the silicone elastomer with a conventional paint that is less likely to attract dust. Specifically, a room-temperature-curable polysiloxane composition consisting of an alkyd resin, a silanol-terminated polydiorganosiloxane with a certain degree of polymerization, and a silicon compound having a hydrolyzable group is dissolved in an organic solvent. A dustproof film is formed by applying the composition on the surface of a silicone elastomer. Although the film formed by this method is certainly excellent in dust-proofing properties, it has the disadvantage of causing so-called repellency and uneven coating unless the coating is done at a certain level of viscosity at the expense of ease of application. . As a result of studying methods for solving the above-mentioned problems, the present inventors have discovered that a volatile organic The coating film-forming material obtained by adding an organic solvent containing a silicon compound has low viscosity and excellent workability, and has good wettability and adhesion to silicone elastomers, and the resulting film is highly dust-proof. , and found that it has good weather resistance. This coating film-forming material was completed as a so-called two-component packaging type, which consists of a main body and a hardening agent, and the two are mixed before use. We proceeded with the study of obtaining forming materials. As a result, by using methyltrimethoxysilane as the hydrolyzable silane, a composition can be obtained that can be stored for a long time in a one-component package and forms a coating film with the best dust-proofing effect. I discovered that. However, methyltrimethoxysilane has a relatively low boiling point and azeotropes with methanol, a hydrolysis product, at even lower temperatures, so this film-forming material does not form a good film in a closed room. However, methyltrimethoxysilane volatilizes outdoors where there is a large amount of air circulation, and as a result, the problem remains that a good coating film cannot be formed unless the amount added is adjusted to an excessive amount. An object of the present invention is to provide a one-component packaged dustproof coating forming material that does not have the above-mentioned drawbacks. As a result of diligent efforts to solve the above problems, the inventors of the present invention discovered that after adding an organic tin compound as a curing catalyst to a mixed solution of an alkyd resin solution and methyltrimethoxysilane, water was added to the mixed solution to cause a partial condensation reaction. By removing methanol, a condensation reaction product, even when cured in an atmosphere with a large air flow rate, the same good coating film as when cured in a closed room can be achieved. The present inventors have discovered that it is possible to obtain a coating film-forming material that provides the following properties, and have completed the present invention. That is, the dust-proof coating film forming material of the present invention comprises (A) 100 parts by weight of an alkyd resin; and (B) 5 to 200 parts by weight of methyltrimethoxysilane;
and (C) a curing catalyst; and (D) a cured product obtained by partial condensation using 0.25 to 1.5 mol of water per 1 mol of methyltrimethoxysilane (B); and (E) a. Formula: (R ¹ ) ₄ Si, (R ² ) ₃ SiO [(R ³ ) ₂ SiO] _n Si (R ² ) ₃ , R
^Four
Si[OSi( ^R5 ) ₃ ] ₃ or [( ^R6 ) _2SiO ]n (wherein ^R1 to ^R6 each represent the same or different alkyl group; m is 0 or a positive integer, (n represents an integer of 3 or more) and has a boiling point in the range of 70 to 250°C under normal pressure; (b) a hydrocarbon solvent; 50 to 5000 parts by weight of a mixed solvent, which is 5 to 95% by weight of the total amount of a) and b);
The composition is characterized in that methanol is removed from the composition. Component (A) used in the present invention is an essential component for forming a dust-proof coating film, and is produced by esterification or transesterification reaction between polyhydric alcohols, polyacidic acids, their anhydrides, and alkyl esters. It is formed by As the polyhydric alcohol, a normal aliphatic polyhydric alcohol, an alicyclic polyhydric alcohol, or an aliphatic polyhydric alcohol containing an aromatic ring is used, and examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and butanediol. 1,4, glycerin, trimethylolpropane, diglycerin, pentaerythritol, sorbitol, cyclohexanediol-
1,4, hydrogenated bisphenol A, and 2,2
-Bis(4-hydroxypropoxybenzene) is exemplified. Polybasic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid,
Examples include maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, and hexahydrophthalic acid.
Examples of polybasic acid anhydrides include succinic anhydride, maleic anhydride, phthalic anhydride, trimellitic anhydride, and pyromellitic anhydride. Furthermore, examples of the alkyl esters include corresponding methyl esters and ethyl esters. In order to form a network molecule by esterification or transesterification reaction and obtain a cured film, at least a part of these components must be a polyhydric alcohol or a polybasic acid having trifunctionality or higher functionality. or a derivative thereof. Also.
If necessary, modifying agents include lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linoleic acid, ricinoleic acid, coconut oil fatty acid, safflower oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, rosin acid, dehydration. Monobasic fatty acids such as castor oil fatty acids and melamine resins may also be added. Of these, in order to form a film with excellent dust resistance, which is the object of the present invention, 50% by weight or more of polybasic acids or derivatives thereof are phthalic acid, isophthalic acid, phthalic anhydride, or methyl thereof. Preferably it is an ester. Furthermore, it is preferable to use a room temperature curable alkyd resin with an oil length of 45% or more, which contains glycerin as a polyhydric alcohol, or a combination of glycerin and ethylene glycol, and a drying oil or semi-drying oil as a modifier. Component (B) used in the present invention undergoes a curing reaction to form a network-like siloxane structure, thereby providing excellent properties characteristic of silicone such as water repellency, heat resistance, weather resistance, and cold resistance. In addition to imparting this to the coating film, it is also a component for developing adhesion between the coating film and the silicone elastomer. By using methyltrimethoxysilane as component (B), it is possible to form a coating film that is more dust-proof than when other hydrolyzable silanes or siloxanes are used.
It becomes possible to obtain a coating film forming material that can withstand long-term storage in a packaged state. The amount of component (B) used must be in the range of 5 to 200 parts by weight per 100 parts by weight of the resin content of component (A). If the amount of component (B) is less than 5 parts by weight, the coating film will lose its weather resistance, heat resistance, water repellency, and other properties, and its adhesion to the silicone elastomer will decrease. On the other hand, if the amount is more than 200 parts by weight, the antifouling effect decreases. Component (C) used in the present invention is obtained by a condensation reaction between component (B) and the alcoholic hydroxyl group remaining in the alkyd resin of component (A) and by adding water, component (D), in the manufacturing process. promotes the partial condensation reaction of Here, partial condensation means that methyltrimethoxysilane is hydrolyzed to become silanol, and then silanol is condensed. However, in the presence of by-product methanol, a reverse reaction between silanol and methanol occurs, and the reaction is in equilibrium. This means that a state is reached in which condensation is not completed. Furthermore, it has the function of accelerating the hardening of the coating film when exposed to the air after application. Examples of these curing catalysts include fatty acid salts such as manganese, cobalt, tin, and zinc; dialkyltin difatty acid salts such as dibutyltin acetate, dibutyltin dioctoate, and dibutyltin dilaurate; and dibutyltin oxide. Component (E) used in the present invention consists of (a) a volatile organosilicon compound and (b) a hydrocarbon solvent, which provides good wettability to the surface of the silicone elastomer of the coating film forming material, and provides uniform It is a necessary ingredient for coating on. The volatile organosilicon compound in b) is a silane or siloxane that does not contain an unstable group, but the presence of a hydrogen atom bonded to a silicon atom is allowed.
It is necessary to have appropriate volatility, in other words, it is necessary that the boiling point under normal pressure is in the range of 70 to 250°C.
If the boiling point is lower than this, it will volatilize early during application and will not work effectively, and if it is too high, drying properties will be poor.
This is because the formation of the film is delayed. Specific examples include silanes such as triethylsilane, dimethyldiethylsilane, and trimethylbutylsilane, linear siloxanes such as hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, and dodecamethylpentasiloxane, and 3-trimethyl Siloxane-1,1,1,
Branched siloxanes such as 3,5,5,5-heptamethylsiloxane, hexamethylcyclotetrasiloxane, octamethyltricyclotetrasiloxane, decamethylcyclopentasiloxane, 1
Examples include cyclic siloxanes such as -ethyl-3,3,5,5,7,7-hexamethylcyclotetrasiloxane, but methyl-based siloxanes are preferred due to their ease of synthesis, particularly those with moderate volatility and Octamethylcyclotetrasiloxane is more preferred in view of the above. Examples of the hydrocarbon solvent (b) include benzene, toluene, xylene, n-hexane, n-heptane, cyclohexane, and gasoline. Among these, toluene and xylene are preferred because of their appropriate volatility, solubility of component (A), and ease of handling. The blending amount of a) must be within the range of 5 to 95% by weight based on the total amount of a) and b),
Furthermore, it is preferably within the range of 10 to 80% by weight. If the amount of (A) is less than 5% by weight, the wettability of the coating film forming material to the silicone elastomer will be reduced, causing repellency and uneven wetting.On the other hand, if the amount is more than 95% by weight, the amount of component (A) will decrease. It becomes impossible to separate and precipitate and obtain a uniform composition. The blending amount of component (E) is 50 parts by weight for 100 parts by weight of component (A).
~5000 parts by weight. If the amount of component (E) is less than 50 parts by weight, the viscosity of the coating film-forming material will increase and the coating workability will decrease, while if it is more than 5,000 parts by weight, it will be necessary to repeat the coating several times to achieve the desired result. film thickness cannot be obtained, and work efficiency decreases. Note that it is also possible to use a lower alcohol as the hydrocarbon solvent, but when this is used, it is preferable to remove it at the stage of manufacturing the forming material of the present invention. At this time, it is preferable that lower alcohols be removed as much as possible. Such lower alcohols have 1 to 10 carbon atoms.
Specific examples include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, sec-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, and isoamyl alcohol. alcohol, sec-amyl alcohol, tert-
Examples include amyl alcohol, 3-pentanol, n-hexanol, methyl amyl alcohol, and n-heptanol. In the present invention, lower alcohols can be removed by ordinary and simple removal means. To produce the forming material of the present invention, first, a mixed solution (for example, an alkyd resin is dissolved in a hydrocarbon solvent) consisting of (A), (B), and (C), and (B) and (C) are dissolved in the solution. Production is started by adding 0.25 to 1.5 moles of water, component (D), to 1 mole of methyltrimethoxysilane (B) to cause a partial condensation reaction. . At this time, for the purpose of improving dispersibility in the mixed solution, water was replaced with methanol,
It is preferable to use it as a mixed solution with a lower alcohol such as ethanol or isopropyl alcohol. Incidentally, as the hydrocarbon solvent for dissolving the alkyd resin, the same ones as mentioned above can be used. If the amount of water added per mole of methyltrimethoxysilane is less than 0.25 mole, the amount of methyltrimethoxysilane present in the film-forming material in the form of a monomer becomes excessive. At this time, methyltrimethoxysilane has a relatively low boiling point (bp 102°C) and azeotropes with the hydrolysis product methanol at an even lower temperature (bp 47.5°C), so it is not lost by volatilization during coating drying. It becomes easier. As a result, due to the large amount of air flow on the exterior walls of buildings where this type of paint film-forming material is mainly used, its volatilization loss is particularly significant, and as a result, properties such as weather resistance and water repellency of the paint film are affected. In addition to this, adhesion to the silicone elastomer is not developed. On the other hand, if the amount of water added is more than 1.5 mol, the viscosity increases during production, making it difficult to obtain a uniform composition. In addition, before adding water to perform a partial condensation reaction, a mixed solution consisting of (A), (B), and (C) is heated to a reflux temperature using a solvent or methyltrimethoxysilane and their azeotrope. It is advantageous to complete the reaction between the alcoholic hydroxyl groups remaining in the alkyd resin and methyltrimethoxysilane in order to obtain a coating film-forming material that is uniform and has excellent gloss. Condensation reaction is usually carried out at 50-150℃, preferably 60-120℃
It is carried out in a temperature range of ℃. Reaction time is usually 0.5
~6 hours, preferably 1 to 3 hours. Next, simultaneously with the above condensation reaction or after the completion of the condensation reaction, methanol belonging to the lower alcohol, which is a reaction product, is removed. Examples of removal means include distillation, extraction, adsorption means, etc., but the means are not particularly limited as long as methanol can be removed. Among these, distillation means are most preferred for ease of operation. Distillation is usually carried out under reduced pressure or normal pressure. At this time, the distillation temperature is usually set to be higher than the boiling point of methanol under the pressure during distillation. Incidentally, when a lower alcohol is used as a solvent for water to carry out partial condensation, it is preferable that this is also distilled off.
Methanol, a condensation reaction product, is contained in the coating film forming material.
If the lower alcohol used as a solvent for water remains, it is undesirable because it will cause reluctance when applied to the surface of the silicone elastomer and a uniform coating will not be formed. At this time, the distillation temperature is set to be higher than the boiling point of the lower alcohol having the highest boiling point. Finally, the production is completed by adding the above-mentioned required amount of the volatile organosilicon compound (E). In addition,
At this time, a hydrocarbon solvent is added as necessary to adjust the viscosity. Examples of the hydrocarbon solvent include the same compounds as mentioned above, but if a lower alcohol is used, it must be redistilled. The forming material of the present invention can also be produced by adding component (E) to the mixture obtained after the condensation reaction and then removing the lower alcohol described above. Even in this case, the same removal means and distillation conditions as above are selected. The coating film forming material of the present invention can be stored for a long period of time as a one-component package, and has good wettability and adhesion to silicone elastomers. Further, after application, the curing reaction proceeds quickly and the surface dries, and the coating film formed is uniform, has excellent dust resistance, and is highly weather resistant. Therefore, the coating film-forming material of the present invention is suitable as a top coat material for a silicone elastic coating material to be applied to the outer wall surface of a building where aesthetics are primarily important. Hereinafter, the present invention will be explained in detail with reference to Examples. In the examples, all parts represent parts by weight. Preparation Example 1 A 50% toluene solution of an alkyd resin obtained from raw materials containing phthalic anhydride, pentaerythritol, and linseed oil fatty acids in a weight ratio of 25:30:45, respectively.
parts, 0.1 parts of zinc octoate and 100 parts of titanium oxide
part was added and dispersed using a ball mill. Hereinafter, this product will be referred to as (A-1). Preparation Example 2 0.1 part of cobalt naphthenate and 100 parts of titanium oxide were added to 200 parts of a 50% triene solution of an alkyd resin obtained from raw materials with a weight ratio of 35:25:40 for terephthalic acid, glycerin, and linoleic acid, respectively, and milled in a ball mill. It was dispersed using Below is this (A
-2). Preparation Example 3 0.1 part of tin naphthenate and 100 parts of titanium oxide were added to 200 parts of a 50% triene solution of an alkyd resin obtained from raw materials containing isophthalic acid, glycerin, and linseed oil fatty acids in a weight ratio of 30:25:45, respectively. It was dispersed using a ball mill. Hereinafter, this product will be referred to as (A-3). Reference Example 1 100 parts by weight of silanol group-endblocked polydimethylsiloxane with a viscosity of 20,000 cst at 25°C, 10 parts by weight of fumed silica surface-treated with octamethycyclotetrasiloxane, 10 parts by weight of titanium oxide, and 100 parts by weight of heavy calcium carbonate. were mixed in a kneader to obtain a base compound. To this, 0.25 parts by weight of dibutyltin laurate and 4 parts by weight of methyltris(butanone oxime) silane were sequentially added and mixed while keeping moisture out. 100 parts by weight of kerosene was added and mixed, and the mixture was applied onto a mild steel plate using a paint brush. After curing at room temperature for 7 days, the film thickness of the silicone elastic material was measured.
It was approximately 0.4mm thick. The silicone elastic body coated iron plate thus obtained is shown below (test specimen-1).
It is written as Reference Example 2 A base compound was obtained by mixing 65 parts by weight of ground calcium carbonate and 10 parts by weight of titanium oxide with 100 parts by weight of silanol group end-capped polydimethylsiloxane having a viscosity of 5000 cSt at 25°C. This contains 93% by weight

[Formula] and 7 weight%

3.0 parts by weight of a crosslinking agent mixture consisting of the formula was mixed. To this thing,
Further, 100 parts by weight of xylene was added to form a liquid, which was applied to the surface of a glass plate using a brush to a thickness of about 0.5 mm, and cured at room temperature for 7 days. The silicone elastomer-coated glass plate thus obtained is hereinafter referred to as (test specimen-2). Example 1 Methyltrimethoxysilane and dibutyltin dilaurate in the amounts (parts) shown in Table 1 were added to 300 parts of (A-1) and mixed uniformly in a flask. Next, a mixed solution of water and methanol in the amount (parts) shown in Table 1 was added, and the mixture was stirred at room temperature for 30 minutes. Next, a reflux condenser was attached and stirring was performed at reflux temperature for 30 minutes. Note that the solution temperature during reflux was 69°C. Next, after cooling to below the reflux temperature, the reflux condenser tube was replaced with a distillation tube, and methanol was distilled off. At this time, the gas temperature in the flask began to rise rapidly, and when it reached 80°C, heating was stopped and distillation was completed. Next, after cooling the solution to room temperature, volatile siloxanes shown in Table 1 were added to obtain samples 11-15. After applying the thus obtained sample to the surface of (test specimen-1) and observing the coating properties, the sample was placed at room temperature while blowing air with a blower so that the air flow rate on the sample surface was approximately 2 m/sec. The time required for the surface to become dry to the touch was measured. After blowing air for 24 hours, the blowing was stopped, and the material was cured for 5 days at the same temperature. After curing was completed, a test specimen shown in the drawing was prepared and a tensile test was conducted to measure the adhesion of the coating film forming material to the silicone elastomer (arrows in the drawing indicate the tensile direction). The results are shown in Table 1. In addition, the sample-applied test specimen prepared in the same manner was exposed outdoors, and the degree of staining was read using Munsell lightness. The results are also shown in Table 1. Note that sample 16 is a comparative example in which methyltrimethoxysilane is not partially condensed, sample 18 is a comparative example in which methyltrimethoxysilane is not added, and sample 17 is a comparative example in which no volatile organosilicon compound is added. In addition, a specimen to which no sample was applied (test specimen-1) was also exposed at the same time for comparison.

[Table] Example 2 Methyltrimethoxysilane and dibutyltin dilaurate in the amounts (parts) shown in Table 1 were added to 300 parts of (A-1) and mixed uniformly in a flask. Next, attach a reflux condenser and adjust the liquid temperature to 40-45℃.
The amount (parts) of water shown in Table 2 was added dropwise at a rate of about 1 drop per second while stirring the mixture at a rate of about 1 drop per second.
After the dropwise addition of water was completed, stirring was continued for 1 hour at the same temperature, then heating was started and stirring was continued for 30 minutes at reflux temperature. Next, after cooling down to below the reflux temperature, replace the reflux condenser tube with a distillation tube.
Methanol was distilled off. At this time, the gas temperature in the flask began to rise rapidly, and when it reached 80°C, heating was stopped and distillation was completed. Next, after the solution was cooled to room temperature, xylene of the same weight as the methanol distilled off and volatile siloxane shown in Table 2 were added to obtain samples 21 to 25. A tensile test similar to that in Example 1 was conducted using the sample thus obtained. The results are shown in Table 2. Sample 26 is a comparative example in which methanol, which is a partial condensation reaction product, is not distilled off, and xylene of the same weight as the distilled methanol is not added.

【table】

[Table] Example 3 Using 300 parts of (A-2) as a phthalic acid resin solution, samples 31 to 38 were obtained with the compositions shown in Table 3. As a silicone elastomer coating test specimen (test specimen-
A tensile test similar to that in Example 1 was conducted using 2). The results are shown in Table 3. In addition, sample 36
is a comparative example in which methyltrimethoxysilane was not partially condensed, sample 38 was a comparative example in which methyltrimethoxysilane was not added, and sample 37 was a comparative example in which no volatile organosilicon compound was added. In addition, a specimen to which no sample was applied (test specimen-2) was also exposed at the same time for comparison.

【table】

[Table] Example 4 (A-3) Amounts (parts) shown in Table 4 for 300 parts
of methyltrimethoxysilane were mixed and stirred for 1 hour at the reflux temperature of methyltrimethoxysilane. Next, after cooling the solution temperature to room temperature, the same operation as in Example-2 was performed, and the same tensile test as in Example-1 was conducted. The results are shown in Table 4. Sample 46 is a comparative example in which methanol, which is a partial condensation reaction product, is not distilled off, and xylene is not added in the same amount as the distilled methanol.

[Table] Example 5 Immediately after preparing Samples 12, 22, 32, and 42, they were sealed in glass bottles and left in a constant temperature bath at 50°C. After one month had passed, the sample was taken out from the thermostat, cooled to room temperature, and then subjected to a tensile test in the same manner as in Example-1. The results are shown in Table 5.

【table】 [Brief explanation of drawings]

The figure is a perspective view of a test specimen used in Examples to measure the adhesion of a sample coating film to a silicone elastomer. 1... Sample coating film, 2... Silicone elastic body, 3
... Mild steel plate or glass substrate, 4 ... Integrally molded metal fitting made of aluminum or aluminum alloy, 5
...Silicone sealant (product name Tosseal)
381, manufactured by Toshiba Silicone Corporation).

Claims (1)

[Scope of Claims] 1 (A) 100 parts by weight of alkyd resin; and (B) 5 to 200 parts by weight of methyltrimethoxysilane;
and (C) a curing catalyst; and (D) a cured product obtained by partial condensation using 0.25 to 1.5 mol of water per 1 mol of methyltrimethoxysilane (B); and (E) A: (R ¹ ) ₄ Si, (R ² ) ₃ SiO [(R ³ ) ₂ SiO] _n Si (R ² ) ₃ , R
^Four
Si[OSi( ^R5 ) ₃ ] ₃ or [( ^R6 ) _2SiO ]n (wherein ^R1 to ^R6 each represent the same or different alkyl group; m is 0 or a positive integer, (n represents an integer of 3 or more) and has a boiling point in the range of 70 to 250°C under normal pressure; (b) a hydrocarbon solvent; 50 to 5,000 parts by weight of a mixed solvent that is 5 to 95% by weight of the total amount of a) and b); A dust-proof coating film forming material obtained by removing methanol from a composition. 2. The dust-proof coating film forming material according to claim 1, wherein the alkyd resin (A) is a room temperature curable alkyd resin. 3. Claims in which 50% by weight or more of the polybasic acid or its derivative constituting the alkyd resin of (A) is a phthalic acid compound selected from phthalic acid, isophthalic acid, alkyl esters thereof, and phthalic anhydride. The dust-proof coating film forming material according to item 1. 4. The dust-proof coating film forming material according to claim 1, wherein ^R2 to ^R6 in (E) are methyl groups. 5. The curing catalyst in (C) is a single or combined catalyst selected from fatty acid salts of manganese, cobalt, tin, or zinc; dialkyltin difatty acid salts of dibutyltin diacetate, dibutyltin dioctoate, or dibutyltin dilaurate; and dibutyltin oxide. The dust-proof coating film forming material according to claim 1, comprising: