JPS6324554B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a surface treatment agent for changing surface properties such as imparting water repellency to a solid surface, and particularly to a surface treatment agent for forming a film with excellent heat resistance and durability. Many industrial products are known that are used to make solid surfaces water repellent. Among the purposes of making the surface water repellent is to prevent contamination caused by adhesion of water droplets and the resulting deterioration of electrical insulation properties. Examples of this include protective films for automobile body paint and protective films for electrical equipment used outdoors, such as insulators. Various types of refrigeration equipment are also treated with water repellent treatment to prevent frost formation due to water adhesion. Additionally, cooking utensils and the like are subjected to surface treatment to prevent them from burning during heating. Fields in which water-repellent surface treatments are highly effective are those in which their non-stick properties are utilized. For example, in the field of electronics industry, a photo-etching process is used to form patterns for LSIs and the like. In that case, in the step of exposing the photoresist film formed on the LSI substrate, a pattern mask is brought into close contact with the photoresist, and exposure processing is performed. The mask is removed after the exposure process, but if the removability between the mask and the photoresist film is poor, the photoresist film will adhere to the mask and cause pattern defects, so in order to improve the removability of the mask, Surface treatment is performed. Molds used in other fields, such as plastic molding, are also often treated with water repellent treatment to improve mold releasability. In addition, for the purpose of preventing fusion between the tape or disk and the magnetic head in a magnetic recording device,
Water repellent treatment is performed on the surface of the magnetic head. Conventionally, organic silicone compositions have been used for these water repellent treatments. This method involves applying an oily composition and baking it at a high temperature. However, this method is limited in the substrates that can be used because it involves a step of baking at a high temperature. Moreover, it has the disadvantage that it is susceptible to dimensional changes due to high-temperature treatment and cannot be applied to high-precision applications. In addition, although the water-repellent film was subjected to high-temperature treatment, the heat resistance of the water-repellent film was low and its durability was poor. Another method is polytetrafluoroethylene baked film. This treated membrane is used in many cooking utensils that use heat. However, this method requires processing at a very high temperature, and is more limited in materials and uses than the silicone-based processing described above, making it less versatile. Another drawback is that the materials are very expensive. In any of the above cases, it is difficult to locally make only a portion of the substrate water repellent, and in this respect, the method lacks versatility. The present invention was made to improve these drawbacks of the prior art, and its purpose is to form a surface treated film with excellent heat resistance and durability despite the low processing temperature. The purpose of this invention is to provide a processing agent that obtains the desired results. Another object of the present invention is to provide a treatment agent that can easily form a surface treatment film locally by a printing method or the like. To summarize the present invention, the first invention of the present invention relates to a surface treatment agent, which has the following general formula: It is characterized by containing a fluoroalkylsilane-modified silanol oligomer obtained by modifying a silanol oligomer represented by (n represents a number from 10 to 20) with a fluoroalkylsilane. ) The second invention of the present invention relates to another surface treatment agent, and is characterized by containing the fluoroalkylsilane-modified silanol oligomer and film-forming polymer according to the first invention. The present invention uses a silane compound having a fluoroalkyl group that is effective for lowering surface energy.
Products containing fluoroalkylsilane-modified silanol oligomers obtained by reacting with silanol oligomers typically have excellent water repellency; This was based on the discovery that it is compatible with the film-forming polymer of . The advantages of the fluoroalkylsilane-modified silanol oligomer single film in the first aspect of the present invention include high heat resistance, low film formation temperature,
It can be processed at low temperatures and has good transparency. This is because it can be applied as a solution in a solvent and dried to form a film, and the solvents include ether alcohols such as butyl cellosolve and carbitol,
There is also ethanol. Furthermore, according to the second aspect of the present invention, it is also possible to form a film locally by a printing method. This is because by selecting a film-forming polymer, a solution with a viscosity suitable for printing can be obtained. Moreover,
Since this polymer mediates the bond with the substrate, the conventional high-temperature baking process is not necessary, and the film can be formed at a temperature below 150°C, which is the temperature required to remove the solvent. Furthermore, surprisingly, regardless of the heat resistance of the coexisting polymer itself, the inherent heat resistance of fluoroalkylsilane is exhibited, and water repellency is maintained up to a high temperature of approximately 450°C. In view of the correspondence with the results of thermal analysis, this temperature corresponds to the temperature at which the fluoroalkyl group is detached from the silanol main chain. In addition, since the fluoroalkyl group controls water repellency, the surface is made with much lower energy than conventional silane treatment, which achieves water repellency using alkyl or aromatic groups. A water-repellent, non-stick, and stain-resistant surface could be obtained. The silanol oligomer used in the present invention has the formula: (n is a number from 10 to 20) It is a silicone compound represented by: The fluoroalkylsilane used to modify this silanol oligomer means a silane compound containing a fluoroalkyl group, and a typical one is represented by the following general formula. (Here, R _f is a perfluorocarbon group, Z
represents a direct bond, -O-, -COO-, X represents a lower alkyl group, Y represents a lower alkoxy group,
(p represents a number from 1 to 3, and q represents a number from 0 to 2) Specific examples include the following compounds. Here, an example of the production of the fluoroalkylsilane-modified silanol oligomer used in the present invention is as follows. 1 Production example of silanol oligomer Synthesize using the solution polymerization method according to the following procedure. In a 200 ml flask equipped with a thermometer, stirrer, and condenser, add 20.5 g of ethyl silicate Si (OC ₂ H ₅ ) ₄ , 37.4 g of ethanol, 14.4 g of ethyl acetate, and 1.5 g of acetic anhydride.
g, 150 mg of phosphorus pentoxide were added at the same time, and the temperature was 1.5 at 70℃.
Allow time to react. Thereafter, 7 g of ion-exchanged water is added, and the mixture is reacted at 70° C. for 1.5 hours to obtain a silanol oligomer solution. 2 Production example 1 of modified silanol oligomer The silanol oligomer solution synthesized in Example 1 above was
Add 53.3g and 0.62g of 8D silane to a 100ml flask and react at 20℃ for 5 hours with stirring.
Make an 8D silane-modified silanol oligomer solution. 3 Production Example 2 of Modified Silanol Oligomer Weigh 10 g of an 8% butyl cellosolve solution of silanol oligomer, and add 0.3 g of 8D silane to it. This was placed in a 50 ml Erlenmeyer flask, a cooling tube was attached to the mouth of the flask, the liquid was stirred with a stirrer while cooling with water, and the mixture was reacted for 2 hours in a constant temperature water bath at 70°C to obtain an 8D silane-modified silanol oligomer. The structure of the fluoroalkylsilane-modified silanol oligomer used in the present invention is estimated to be as shown in the following formula as a model. The appropriate amount of fluoroalkylsilane to be bound into the silanol oligomer is 10 to 80%.
This corresponds to a ratio of silicon in the silanol oligomer to silicon in the fluoroalkylsilane of 20:1 to 1:1. Many commercially available film-forming polymers can be used in the present invention. As a general selection criterion, good film formability is required.
It is also necessary to have excellent adhesion to the substrate, high heat resistance, and excellent abrasion resistance. Although not limited to the following, for example, polymers that undergo a thermal decomposition reaction and disappear upon heat treatment, such as nitrocellulose, hydroxypropyl cellulose, and polymethyl methacrylate, can be used.
In addition, aliphatic polyamides, aromatic polyamides, aromatic ether polyamides, polyester imides, polyamide imides, polyimides, polyhydrazidoimides, which have high heat resistance and can be formed into films at low temperatures,
Polybenzimidazole and the like were useful polymers. These polymers are added directly to the fluoroalkylsilane-modified silanol oligomer solution or in the form of a solution in a suitable solvent. The blending amount of these polymers is arbitrary, but
In order to obtain satisfactory water repellency, the appropriate amount is 50% by weight or less. Hereinafter, the effects of the present invention will be explained in detail based on some examples. The attached drawing is a graph showing the relationship between the contact angle of water and the heat treatment temperature on the treated film surface prepared in the later-described example of the present invention, and illustrates the heat resistance effect, as will be described in detail later. It is something. An example of a single film of a fluoroalkylsilane-modified silanol oligomer according to the first aspect of the present invention will be shown below. Examples 1 to 9 Silanol oligomers were reacted with the fluoroalkylsilanes shown in the table below to produce fluoroalkylsilane-modified silanol oligomer solutions with a solid content concentration of 6% by weight. Note that 1/30 of the number of --OH groups in the silanol oligomer are substituted with fluoroalkylsilane. Each was applied to a glass substrate using a spinner, heated at 100℃ for 1 hour, and then heated at 200℃.
After heating for 1 hour, a treated film with a thickness of about 1000 Å was obtained. The results of measuring the contact angle of these treated membranes with respect to water are shown in Table 1 below.

[Table] Examples 10 to 13 Silanol oligomers were reacted with 8D silane to prepare 8D silane-modified silanol oligomer solutions with a solid content concentration of 6% by weight. The amount of 8D silane substitution relative to the number of -OH groups in the silanol oligomer was 1/40 (Example 10), 1/20 (Example 11), and 1/10, respectively.
(Example 12) and 1/5 (Example 13). Coat these on a glass substrate with a spinner and heat at 100℃ for 1
The mixture was heated for 1 hour and further heated at 200° C. for 1 hour to form a treated film with a thickness of about 1000 Å. The contact angles of these treated membranes with water were as shown in Table 2 below.

[Table] Examples of treated membranes containing a fluoroalkylsilane-modified silanol oligomer and a membrane-forming polymer according to the second aspect of the present invention are shown below. Examples 14 to 27 Water-repellent treatment by mixing a 10% by weight solution of 8D silane-modified silanol oligomer with butylcelloselb and an 8% by weight N-methyl-2-pyrrolidone solution of polyimide resin (PIQ, registered trademark, manufactured by Hitachi Chemical Co., Ltd.) It was made into a liquid. Fourteen types of treatment solutions were prepared by varying the 8D silane content in the silanol oligomer and the blending ratio of the 8D silane-modified silanol oligomer to PIQ. Using these treatment solutions, apply the coating onto a soda glass plate using the spin coating method and leave it at 100℃ for 1 hour.
Subsequently, it was dried at 200° C. for 1 hour to form a treated film. Thereafter, the contact angle of the treated membrane surface with water was measured using an Elmer type contact angle meter. Table 3 shows the composition of the film and the measurement results of the contact angle. In addition,
For comparison, Table 3 also shows the measurement results of the contact angle on an untreated soda glass plate and a commercially available Teflon plate.

[Table] From these results, it can be seen that many treatment solutions exhibit water repellency equivalent to or better than Teflon. Note that the contact angle of water was measured after heating soda glass plates treated with the same treatment liquid as in Example 17 at each temperature for 1 hour. The results are shown in the attached drawings. Since it shows a high contact angle up to almost 450℃,
It can be seen that this is a water-repellent membrane with excellent heat resistance. Example 28 A solution of 2,2-bis[4-(4-aminophenoxy)phenyl]-propane and isophthalic acid chloride is added to a 10% butyl cellosolve solution of a 4T silane-modified silanol oligomer with a 4T silane content of 5 mol%. A legally synthesized aromatic ether polyamide was added so that the proportion of the polyamide in the solid content was 50% by weight, and the mixture was stirred and mixed to obtain a uniform solution as a water repellent treatment agent. Using this treatment liquid, the thickness is
It was coated on a 200 μm polyethylene terephthalate film and dried at 120° C. for 2 hours to form a treated film. Thereafter, the contact angle of the surface of this treated membrane with water was measured and found to be 108±3 degrees, indicating hydrophobicity comparable to Teflon. Example 29 Add ethyl cellulose to the treatment solution of Example 28.
A printing processing liquid was prepared by adding 1 part by weight per 100 parts by weight. This treatment solution was applied to a soda glass plate using the letterpress printing method, and then heated at 100°C for 1 hour.
It was dried at ℃ for 1 hour to form a treated film. The contact angle of water on this membrane surface was 104±2 degrees. Examples 30-38 A 10% by weight butyl cellosolve solution of a fluoroalkylsilane-modified silanol oligomer with a different structure of the fluoroalkyl group was prepared. The fluoroalkylsilane content at this time was 11.0 mol%. An aliphatic polyamide (Trogamid-T manufactured by Dynamite Nobel) was added to and dissolved in these oligomer solutions so that the aliphatic polyamide content was 40% to obtain a water repellent treatment liquid. Using this treatment liquid, apply it to a part of a soda glass plate by letterpress printing method, and
The treated film was then dried at 200° C. for 1 hour to form a treated film. For these treated plates, the contact angle of water was measured on the surface with the treated membrane and the surface without the treated membrane. The results are shown in Table 4.
This shows that localized water repellent treatment is possible.

[Table] In addition to water repellency, the surface treatment agent of the present invention has excellent non-adhesive properties, mold releasability, oil repellency, lubricity, and stain resistance, and can be used for various purposes.

[Brief explanation of the drawing]

The attached drawing is a graph showing the relationship between the contact angle of water and the heat treatment temperature on the surface of the treated membrane prepared in Example 17 according to the present invention.

Claims (1)

[Claims] 1. The following general formula: A surface treatment agent comprising a fluoroalkylsilane-modified silanol oligomer obtained by modifying a silanol oligomer represented by (n represents a number from 10 to 20) with a fluoroalkylsilane. 2 General formula below: A surface treatment agent comprising a fluoroalkylsilane-modified silanol oligomer represented by (n represents a number of 10 to 20) modified with a fluoroalkylsilane, and a film-forming polymer.