JPS6032652B2 - Dust-proof film formation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a dustproof coating on the surface of a silicone elastomer, particularly a silicone elastomer formed by curing at room temperature.

Various types of polyorganosiloxane compositions that cure at room temperature to become rubber-like elastic bodies are known.

For example, hydrolysis of acetoxy groups, alkoxy groups, dialkylketoxime groups, dialkylaminoxy groups, dialkylamino groups, N-methylacetamide groups, etc. that are bonded to silicon atoms in polydiorganosiloxanes whose both ends are blocked with silanol groups Products using organosilicon compounds having a crosslinking group as a crosslinking agent are widely used in the construction industry, automobiles, electrical equipment, and other industries. In the construction industry, it is widely used for fireproof sealing of voids in building wall materials such as formed concrete and aluminum plates, for fixing glass to sashes, and for adhering glass to glass, and is collectively known as silicone sealant. In particular, it has excellent weather resistance and durability, as well as heat and cold resistance, little change in physical properties due to temperature, no deterioration due to ozone or ultraviolet rays, and good workability during construction, so it is used for high-rise buildings and other purposes. ,
Demand is increasing. In addition, it has recently begun to be used as a coating material by applying this type of cross-linked polyorganosiloxane to roofs and walls to form a silicone elastic layer with excellent fire and film resistance. There is. Although such silicone elastomers have the excellent properties mentioned above, they remain slightly sticky even after the curing reaction is completed, and because their main component, polydiorganosiloxane, is a dielectric, they are susceptible to dust. Easy to absorb.

In particular, when non-reactive polydiorganosiloxane is added to obtain a flexible silicone elastomer while maintaining workability, the polysiloxane 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 it water-repellent, the dust is not washed away by rainwater, etc., and the aesthetic appearance is significantly deteriorated due to staining. In order to prevent such staining, the present inventors have previously found that it is effective to include a surfactant in a polyorganosiloxane composition that can be cured into a rubbery state.

This method has the advantage that there is no need to increase the number of applications because the stain prevention agent is present in the sealant, and that it can follow the fluctuations in joint width.
In order to prevent the mechanical properties and adhesive properties from decreasing after immersion in water, it is necessary to use an inorganic filler with a hydrophobic surface as the filler. The present inventor has conducted extensive research on preventing staining of the surface of such a sea J-cone elastic body.

Benzene-soluble polyorganosiloxane resins containing trifunctional to tetrafunctional siloxane units and having a molar ratio of organic groups to silicon atoms in the molecule of less than 2 are usually prepared using hydrocarbon solvents such as toluene, xylene, gasoline, etc. It is mixed with alcoholic polar solvents such as isopropanol, butanol, methoxyethanol, and ethoxyethanol, and in the form of a solution, it is used as a silicone varnish in paints, insulating materials, etc.

The present inventor has discovered that among these silicone varnishes, those that can be cured at room temperature or relatively low temperature form a thick surface on which dust adheres when cured on the surface of a silicone elastic body. However, they have poor wettability on the surface of silicone elastomers, cause repellency, and are difficult to form a uniform film. Therefore, the inventor of the present invention conducted extensive research into a solution to this problem, and found that by using a mixture of a hydrocarbon solvent and silaso or siloxane, which is volatile and does not undergo hydrolysis under normal conditions, as the solvent for the silicone resin. The present invention was completed based on the discovery that the wettability to the surface of a silicone elastomer was significantly improved. That is, the present invention has the following characteristics: ■'11 Average composition formula R period (OR2) b04-hot-b(
However, RI is a substituted or unsubstituted monovalent hydrocarbon group that is the same or different, and R2 is a hydrogen atom or a carbon number 1
-4 alkyl group, a is 0.85-1.8, b is 0.0
1 to 2, and a+b does not exceed 3), and when [21'1} exceeds 2% by weight, a mixture of '1} and an organic resin or Copolymer.

A silicone resin selected from the group consisting of (B} W
The molecular formula is RashiSi, RkiSj0 [RkyoSi○]mSI
R, or [R room Si○]n (however, R3 to R in the formula
6 are the same or different hydrogen atoms or alkyl groups, m is 0 or a positive number, n is a positive number), and the boiling point at normal pressure is in the range of 70 to 250 oo. and 'o) a hydrocarbon solvent, where the amount of 'i' is 5 of the total amount of 'i' and [o}.
The present invention relates to a method for forming a dust-proof film, which comprises dissolving the specified composition in a mixture having a concentration of up to 75% by weight, applying the special composition to the surface of a silicone elastomer, and drying and curing it.

The polyorganosiloxane resin having a wind {1-} used in the present invention has an RI/Sj of between 0.85 and 1.8, for example, a combination of Si02 units and RxSi○,'2 units, RI
Combination of Si03′2 unit and R with Si○ unit, RISi
It is composed of only 03'2 units, etc., but is not particularly limited to these examples.

Examples of RI include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, amyl group, hexyl group, octyl group, and decyl group, alkenyl groups such as vinyl group, aralkyl groups such as 8-ethylphenyl group, and phenyl group. Examples include aryl groups such as groups, and those in which some of these hydrogen atoms are substituted with chlorine atoms, fluorine atoms, nitrile groups, etc., and can be cured by heating at room temperature or relatively low temperature to form a film. In particular, methyl groups and 0 to 70 mol% of phenyl groups in RI are preferred because the film has excellent weather resistance and is easy to synthesize. If the RI/Si is less than 0.85, the stability during storage will be poor, and although the film will harden quickly, it will become brittle, and cracks will occur especially when the film is formed on the surface of the silicone elastic material applied to the joint area. If it exceeds 1.8, it will not cure at room temperature unless a fairly strong curing catalyst is used, and a good dustproof film will not be formed on the surface of architectural sealants and coating materials. Moreover, the film becomes soft and does not exhibit dust-proofing effects.
In such benzene-soluble polyorganosiloxane resin, the molecules become large and form an insoluble and infusible film.
From 0.01 to 2 hydroxyl and/or lower alkoxy groups should be present per silicon atom. As the lower alkoxy group, a group having at most 4 carbon atoms, such as a methoxy group or an ethoxy group, is selected because it easily forms a film at room temperature. One typical example of a polyorganosiloxane resin with a high degree of stability is Si02 units and R
It is composed of iO,/2 units and has a relatively low molecular weight with a hydroxyl group bonded to a silicon atom.

This type has excellent adhesion to the surface of the silicone elastic body. The ratio of R Si○,/2 units is S
It is preferably between 0.4 and 1.0 mol, more preferably between 0.5 and 0.8 mol, per mol of i02 units. R
If the amount of stem Si0,/2 units is small, it is difficult to stably obtain a benzene-soluble, low-molecular-weight polymer, and it tends to gel during synthesis or storage, resulting in an infusible polymer. Also Rki Si
○, If there are too many /2 units, a film having sufficient dust prevention effect will not be formed. RI is preferably a methyl group because it is easy to synthesize and it is easy to form a dustproof film at room temperature. Such polysiloxane is produced by adding a tetrafunctional silicon-containing compound selected from alkyl silicates such as ethyl silicate and propyl silicate, partial condensates thereof, silicon tetrachloride, and water glass to trimethylchlorosilane, trimethylchlorosilane, and water glass in the presence of a solvent. It can be obtained by cohydrolyzing it with a trialkylchlorosilane such as dimethylvinylchlorosilane or dimethylphenylchlorosilane and removing by-products by conventional means. As a solvent,
Hydrocarbons such as benzene, toluene, xylene, gasoline, n-hexane, n-hebutane are commonly used.
Another typical example of {1) is one composed of RISiO3/2 units and RSi○ units, and has a hydroxyl group or lower alkoxy group bonded to a silicon atom.

This type of material ranges from those that are easy to synthesize and have excellent magnetization and dust resistance to those that are flexible and can withstand stress.
Any combination of siloxane units can be obtained. From the viewpoint of ease of synthesis and ability to form a dustproof film, RI is preferably a methyl group or a combination of a methyl group and a phenyl group. The amount of phenyl groups is preferably 45 mol % or less in RI, from the viewpoint of easily curing at room temperature to obtain a strong film, when the polyorganosiloxane resin is used alone. More preferably between 20 mol%. Further, RI/Sj is preferably 1.55 or less, more preferably 1.1 or less in terms of curability and excellent dust resistance. In addition, for construction purposes, expansion and
If the stress applied to the silicone elastomer due to shrinkage is large, the dustproof coating should also be flexible;
R/Si is preferably between 1.3 and 1.8. Another typical example of the leg {1} is one consisting essentially only of RISi03/2 units, where the reactive groups bonded to the silicon atom are only a lower alkoxy group, or a lower alkoxy group and a hydroxyl group.

This type has excellent curing properties at room temperature. In terms of its curability, it is preferred that the RI consists of only methyl groups, or methyl groups and up to 15 mol% of phenyl groups in the RI. Kaze (2) is a mixture or copolymer of the aforementioned polyorganosiloxane resin and an organic resin.

As the polyorganosiloxane resin, from the viewpoint of compatibility with the organic resin, the above-mentioned RISi03/2 unit and RSi
A compound with a relatively low molecular weight composed of ○ units is preferable, and the amount of phenyl group is 25 to 70 mol% in RI.
It is recommended to use relatively large amounts. Also RI/
For the same reason, it is recommended that Si be between 1.2 and 1.7, more preferably between 1.25 and 1.55. Epoxy resins, alkyd resins, urethane resins, polyester resins, etc. are used as organic resins due to their compatibility with polyorganosiloxane and their ability to be cured at room temperature or relatively low temperatures. Epoxy resin and urethane resin are excellent. The polyorganosiloxane resin in [2] needs to be at least 2% by weight in order to maintain excellent weather resistance. The polyorganosiloxane resin and the organic resin may be simply blended or copolymerized. The wind is selected from [1} or ■, but {1} is preferable from the viewpoint of the stool resistance of the film and the affinity with the surface of the silicone elastomer. The concentration of evil is 5 to 5 relative to the total amount of evil, another.
A range of 8% by weight is preferred, and a range of 10-50% by weight is more preferred. If the concentration is too low, the thickness of the film obtained with one application will be small and it will be necessary to apply it many times, which will be a great burden when applied to buildings. Also, if the concentration is too high, the viscosity will be high, making it inconvenient to handle.
Moreover, a smooth film cannot be obtained. Buddha used in the present invention {
The volatile organosilicon compound is a silane or siloxane that does not contain unstable groups, and must have appropriate volatility, in other words, a boiling point in the range of 70 to 250 qo. If the boiling point is lower than this, it will volatilize during storage or during application and will not work effectively, and if it is too high, drying properties will be poor and the formation of a film will be delayed. Silanes such as triethylsilane, dimethyldiethylsilane, trimethylbutylsilane; linear siloxanes such as hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylbentasiloxane; hexamethylcyclotrisiloxane, octamethylsiloxane; Examples include cyclic siloxanes such as methylcyclotetrasiloxane, decamethylcyclobentasiloxane, and 1-ethyl-3,3,5,5,7,7-hexamethylcyclotetrasiloxane, which are easy to synthesize. Methyl-based siloxanes, particularly octamethylcyclotetrasiloxane, are preferred. The amount of {B}{i} is required to be in the range of 5 to 75% by weight, preferably 10 to 65% by weight, based on the total amount of 'i) and {rho. If the amount of 'B' is too small, good wettability to the surface of the silicone elastomer cannot be obtained, and if it is too large, particles may precipitate during manufacturing or storage, resulting in cloudy coating, or the film may become cloudy after curing. This is because it cannot be obtained as transparent, smooth, and strong. 'B'.

} The hydrocarbon solvent is preferably a hydrocarbon such as benzene, toluene, xylene, n-hexane, n-heptane, cyclohexane, or gasoline in view of poor solubility. Further, some monohydric alcohol, monohydric ether alcohol, acetone, etc. may be used in combination. Among these, toluene and/or xylene are preferred because of their appropriate volatility, wind solubility, and ease of handling. At room temperature, after the wind is dispersed, the condensation of OR2 (however, R2 is as described above) bonded to silicon atoms progresses and hardens, creating a dust-proof film with a non-stick surface. However, if heating is possible, 150~
It is recommended to accelerate curing by heating to 200°C. However, in cases where heating is difficult or possible, such as when treating the surface of architectural sealants and coating materials, curing catalysts and/or hydrolyzable groups bonded to silicon atoms are used to accelerate curing. An organosilane or organosiloxane in which at least two of the above are present in the molecule is added. Examples of the curing catalyst include organic acid salts of metals such as tin, alkyl titanates, titanium chelate compounds, nickel chelate compounds, cobalt chelate compounds, and amine compounds. Hydrolyzable groups include alkoxy groups such as methoxy, ethoxy, and isopropoxy groups, acyloxy groups such as acetoxy, organoaminoxy groups such as jetylaminoxy, amino groups such as jetylamino, and acetone. Examples include oxime groups such as oxime group and methyl ethyl ketoxime group. Y-aminopropyltriethoxysilane is an example of the aforementioned hydrolyzable silane that also serves as a curing catalyst. In addition, R
When I/Si is small, these curing catalysts and/or
Or, even without adding silane or siloxane having a hydrolyzable group, after the solvent {a) and {o} are dispersed,
A dustproof film can be formed at room temperature. Further, powders such as silica, titanium oxide, calcium carbonate, and carbon black may be added for the purpose of coloring, matting, and reinforcing the film.

The present invention aims to reduce bad luck to [B]'s (iX).

), a curing catalyst and/or a hydrolyzable silane or siloxane are added as needed to the resulting composition, and the mixture is applied to a silicone rubber elastomer. - and 'o) are dispersed and then cured at room temperature or by heating to form a protective film. The silicone rubber elastomer may be of either a room temperature curing type or a heat curing type, but the present invention is particularly important for preventing staining of architectural sealing materials and coating materials where contamination by dust is a problem. These cure at room temperature and have a curing mechanism in which silanol-terminated polydiorganosiloxane, particularly polydimethylsiloxane, is reacted with various crosslinking agents. As a crosslinking agent,
Acetoxy group, methoxy group, dialkylketoxime group, dialkylaminoxy group, dialkylamino group, N-
Examples include silanes and siloxanes in which a reactive group such as a methylacetamide group is bonded to a silicon atom. In particular, low modulus type materials that use an organosilicon compound having a dialkylaminoxy group as a crosslinking agent are particularly prone to fouling, but the method of the present invention can effectively prevent dust from adhering to them. Application is performed by any method such as brushing, roll coating, or spraying. According to the present invention, it has become possible to form a dust-proof film on the surface of a silicone elastomer, in particular, without impairing the properties of a building sealant or coating material. The film obtained by the present invention is strong,
Excellent water resistance. Therefore, the present invention is particularly useful as a method for protecting silicone sealants and coatings for construction, but it is also useful for protecting silicone elastomers that are exposed outdoors for long periods of time, such as coatings for outdoor lights and fishing lights. It is also useful for protection. Hereinafter, the present invention will be explained by examples.

In the examples, all parts represent important parts. Also, to simplify the description, the following abbreviations are used. Me: Methyl group Bu: Butyl group Et: Ethyl group Ph: Phenyl group M: Trimethylsiloxane unit (Me3Si○,'2)
D: Dimethylsiloxane unit (Me2Si○) T: Monomethylsiloxane unit (MeSi03/2) Q: Si0
2 units Dna: diphenylsiloxane unit (Ph2Si○
)T": monophenylsiloxane unit (PhSi03/
2) Example 1 A toluene solution containing 50% polymethylsiloxane resin (hereinafter referred to as , S-1) were added and mixed with D4 and toluene in the amounts shown in Table 1 to prepare Samples 11 to 15.

However, sample 11 is a comparative example. A base compound was obtained by kneading 10 parts of silanol-terminated polydimethylsiloxane having a viscosity of 500 relative st at 25 qo and 10 parts of car-quality calcium carbonate in a kneader.

In addition, 94% by weight and 6% by weight A drug mixture consisting of A silicone sealant was obtained by mixing the three anchor parts of the compound.

This was cured into a sheet approximately 2 skin thick. Samples 11 to 15 were applied to this sheet using a paint brush, and the degree of wettability was observed. Next, the test specimen obtained by drying and curing at room temperature was exposed outdoors and the state of staining was observed.
The results of these observations are shown in Table 1. Symbols in Table 1 (hereinafter referred to in each table) Wettability ◎Very good, 0 good△Slightly repellent, ×Repellent exposure test ○No staining△Slightly soiled×Staining××Significantly soiled [ ] Wetting of polyorganosiloxane Because of its poor quality, the parts to which varnish is attached are not stained, but the parts to which varnish is not are stained.

(Note) *: Added and mixed just before use Example 2 Various organosilicon compounds and xylene were added to the toluene solution S-1 of polymethylsiloxane used in Example 1, and samples were prepared as shown in Table 2. 21-24 were prepared.

This was applied to the surface of the silicone elastic body used in Example 1 using a paint brush, and the same experiment as in Example 1 was conducted. The results are shown in Table 2. Second
Table (note) *1:03 5% by weight, D47 neck weight%, D51
Mixture *2: Added immediately before use Example 3 10 parts of silanol-terminated polydimethylsiloxane with a viscosity of 300% at 25°C and 65 parts of stearic acid-treated calcium carbonate were kneaded in a kneader to form a base compound. Obtained.

This includes a crosslinking agent width of 9% by weight and 7% by weight. Compound 3. The eaves were mixed.

This was applied to a thickness of approximately 5 mm on a galvanized iron plate measuring 100 sides x 5 ribs and cured. Sample 14 prepared in Example 1 and samples 31 to 34 prepared according to the formulations shown in Table 3 were applied to the surface of the silicone coating material thus obtained using a roll, and dried and cured at room temperature to form a test specimen. Obtained. However, the polyorganosiloxane resin solution used is shown below. Further, Sample 31 is a comparative example, and a test specimen not treated with the silicone resin solution was also added as a comparative example. The test specimen thus obtained was exposed outdoors. The wettability during application and the results of the exposure test are shown in Table 3. S-2 A xylene solution S-2 containing 50% polyorganosiloxane resin containing a hydroxyl group bonded to a silicon atom, with a molar ratio of T units, D units, T units, and D units of 2:7:6:3. 3 2 units of polyorganosiloxane resin containing hydroxyl groups bonded to silicon atoms and 45 parts of bisphenol-based epoxy resin with a molar ratio of 2:6:3:3 of T units, D units, T units, and D units. A xylene solution containing 50% of an epoxy-modified silicone resin obtained by heating and condensing , and 22 parts of dodecenyl succinic anhydride in the presence of xylene.

S-4 Polymethylsiloxane resin containing a methoxy group bonded to a silicon atom obtained by partially methoxylating methyltrichlorosilane, followed by hydrolysis and condensation.
Toluene solution containing 0%.

Table 3 (Note) *: Example of adding immediately before use 4 Silanol-terminated polydimethylsiloxane with a viscosity of 2000% at 25°C A base compound was obtained by kneading the mixture.

To this, 0.05 part of dibutylstin diacetate and then 5 parts of a partially hydrolyzed condensate of methyltriacetoxysilane were sequentially added, and the mixture was uniformly kneaded while keeping moisture out.
A base of xylene 10 was added to this, dissolved, and applied to a yellow steel plate, dried and hardened. Samples 41 to 43 shown in Table 4 were applied to this, and after drying at room temperature, it was placed in a 150 qo air circulation temperature bath and heated for 4 hours to harden to obtain a test piece. However, the polyorganosiloxane resin solution used is as shown below, and sample 42 is a comparative sample. Table 4 shows the wettability when these samples were applied and the exposure test results of the test pieces. For comparison, test specimens that were not treated with the resin solution were also subjected to the exposure test. S
-5 A xylene solution containing 60% polymethylsiloxane resin containing a hydroxyl group bonded to a silicon atom, in which the ratio of M units to 1 mole of Q units is 0.8 mol.

S-6 T unit, D unit, T unit molar ratio is 20:1
:3, a xylene solution containing 30% of a polyorganosiloxane resin containing hydroxyl groups bonded to silicon atoms.

Table 4 Example 5 A base compound was obtained by mixing 10 parts of silanol-terminated polydimethylsiloxane having a viscosity of 1250 specific St at 25 qo and 1 part of fumed silica surface-treated with octamethylcyclotetrasiloxane.

To this, 0.5 parts of dibutyltin dilaurate and 4 parts of methyltris(butanone oxime) silane are sequentially added and mixed in a moisture-blocking state to obtain a silicone sealant, which is then sealed in a moisture-proof sealing cartridge. I saved it. Two pieces of concrete, 50 ribs x 5 pieces, 1 piece thick, are lined up with a gap between the IQ sails, extrude silicone sealant from a cartridge into the gap, leave it in the air to harden, and make two pieces of concrete. A silicone elastic body was bonded to the side of the concrete and cured.

The molar ratio of T units, D units, Tna units, and Dna units is 2:8
: 3:1, 4 parts xylene solution containing 60% polyorganosiloxane resin containing hydroxyl groups bonded to silicon atoms, polyol prepolymer, Takenate U-2
5 (Takeda Pharmaceutical ■Product name) 6 Ikarito, 32 parts of xylene,
424 parts of D were mixed uniformly, and then polyisocyanate, Takenate XD-110N (Trade name of Takeda Pharmaceutical Co., Ltd.)
A treatment solution was prepared by mixing 44 parts.

When this was applied with a brush to the surface of the silicone elastic body previously formed, it became uniformly wet and dried at room temperature to form a film. When exposed outdoors, the surface remained clean even after 180 days. Example 6 Fill a sealing application cartridge with the same silicone sealant as used in Example 1, and fill it with 50 ribs x 5 enemies.
Two marble plates with a thickness of 10 willow were arranged with a gap of IQ ribs, and a silicone sealant was extruded from a cartridge into the gap and cured, and adhered to the side of the marble to obtain a cured silicone elastic body.

Sample 61 was prepared by adding D45, 50 parts of xylene, and 1 part of methyltriacetoxysilane to 100 parts of polyorganosiloxane resin 8-6 used in Example 4.

Also, instead of methyltriacetoxylan, 1.5 Sample 62 was prepared using

These samples and Sample 33 prepared in Example 3 were brush-coated onto the surface of the silicone elastomer, dried and cured, and then exposed outdoors. For comparison, an untreated silicone elastomer was also included in the exposure test. Table 5 shows the wettability during application and the results of the exposure test. Table 5

Claims (1)

[Claims] 1 (A) (1) Average composition formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, R^1 is a substituted or unsubstituted monovalent hydrocarbon group that is the same or different from each other) , R_2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, a is a number of 0.85 to 1.8, b is a number of 0.01 to 2, and a+b does not exceed 3). organosiloxane resin,
and (2) If (1) exceeds 20% by weight, (1)
A mixture or copolymer of and an organic resin. A silicone resin selected from the group consisting of (B) (
b) The molecular formula is R^3_4Si, R^4_3SiO[R
^5_2SiO]_mSiR^4_3 or [R^6_
2SiO]_n (wherein R^3 to R^6 are each the same or different hydrogen atom or alkyl group,
m is 0 or a positive number, n is a positive number),
and a volatile organosilicon compound having a boiling point in the range of 70 to 250°C at normal pressure, and (b) a hydrocarbon solvent, where the amount of (a) is 5% of the total amount of (a) and (b).
A method for forming a dustproof film, which comprises dissolving the composition in a mixture having a concentration of up to 75% by weight, applying the resulting composition to the surface of a silicone elastomer, and drying and curing it. 2 Claim 1 in which (A) consists only of (1)
The dust-proof film forming method described in Section 1. 3 (1) is essentially SiO_2 units and R^1_3Si
It consists of O_1/_2 units, R^2 is a hydrogen atom, and Si
R^1_3SiO_1/_2 for 1 mole of O_2 units
The method for forming a dustproof film according to claim 2, wherein the proportion of the units is 0.4 to 1.5 moles. 4. The method for forming a dustproof film according to claim 1, wherein R^1 is a methyl group. 5 (1) is essentially R^1SiO_3/_2 units and R
2. The method for forming a dustproof film according to claim 1, wherein R^1 is a monovalent hydrocarbon group selected from the group consisting of a methyl group and a phenyl group. 6. The method for forming a dustproof film according to claim 2, wherein (1) substantially consists of R^1SiO_3/_2 units.
7. The method for forming a dustproof film according to claim 1, wherein the organic resin in (2) is an epoxy resin. 8. The method for forming a dustproof film according to claim 1, wherein the organic resin in (2) is a urethane resin. 9 The amount of (A) is 5 to 5 to the total of (A) and (B).
The method for forming a dustproof film according to claim 1, wherein the amount is 80% by weight. 10. The method for forming a dustproof film according to claim 1, wherein R^3 to R^6 in (B) (a) are methyl groups. 11 (B) (a) is [(CH_3)_2SiO]_4
The method for forming a dustproof film according to claim 10. 12. The method for forming a dustproof film according to claim 1, wherein the amount of (B) (a) is 10 to 65% by weight based on the total of (a) and (b). 13. The method for forming a dustproof film according to claim 1, wherein the hydrocarbon solvent is an aromatic hydrocarbon selected from the group consisting of toluene and xylene. 14 The silicone elastic body is a building sealing material.
A method for forming a dustproof film according to claim 1. 15. The method for forming a dustproof film according to claim 1, wherein the silicone elastic body is the coating material. 16. The method for forming a dustproof film according to claim 1, wherein the silicone elastomer uses a dialkylaminoxy group-containing organosilicon compound as a crosslinking agent.