JP2010031145A - Water-repellent agent having oil stain removing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous solution type water-repellent agent which has a stain removing function for oil stain or the like deposited on the surface of glass and enables water-repellent film application work to be performed without necessitating a pretreatment step such as oil content wiping work, and which is compliant to PFOS regulation and VOC exhaust regulation. <P>SOLUTION: The water-repellent agent having oil stain removing function contains (A) 5-20 wt.% modified silicone oil covalently bonded with a silanol group exposed on the surface of the glass, (B) 1-10 wt.% abrasive, (C) 0.2-2 wt.% dispersing agent, (D) 10-40 wt.% alcohol, (E) an acid in an amount of 5-30 wt.% of the modified silicone oil and the balance (F) water. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an aqueous solution-type water repellent composition that removes dirt such as oil adhering to a glass surface and the like, in particular, wind glass such as an automobile and at the same time imparts a good water repellent effect.

Heptadecafluorodecyltrimethoxysilane [CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ] has the lowest critical surface tension of 12 dyne / cm among commercially available water repellent compounds. Although it is expensive, it has good water repellency and abrasion resistance due to covalent bonding with a silanol group on the glass surface, and is therefore widely used as a main component of commercially available water repellents. Incidentally, the critical surface tension of fluororesin Teflon ^R , which is standard in this field, is 18.5 dyne / cm.

Patent Document 1 has a function of removing dirt such as oil adhering to the coating surface by adding an abrasive such as silica fine powder to an organic solvent solution containing heptadecafluorodecyltrimethoxysilane or the like. Is disclosed. However, perfluorooctane sulfonate (CF ₃ (CF ₂ ) ₇ SO ₃ ⁻ K ⁺ , abbreviated as “PFOS”), which is a raw material for this heptadecafluorodecyltrimethoxysilane, is harmful to humans, Then, from June 27, 2008, the use was prohibited. For this reason, the use of fluoroalkylsilanes including heptadecafluorodecyltrimethoxysilane is greatly limited.

In Patent Documents 2 and 3, an alkylpolysiloxane represented by the general formula CH ₃ — (Si (CH ₃ ) ₂ —O) n—Si (CH ₃ ) ₃ is dissolved in a half ester solution composed of an acid and an alcohol. A water repellent is disclosed. By the way, the critical surface tension of this alkylpolysiloxane is 16 to 21 dyne / cm, which is higher than that of heptadecafluorodecyltrimethoxysilane, and its wear resistance is somewhat inferior to that of heptadecafluorodecyltrimethoxysilane. Nevertheless, since this alkylpolysiloxane is inexpensive and has good water repellency, it is marketed as an automotive and commercial water repellent under the trade name RAIN-X®.

  However, the water repellent such as RAIN-X (registered trademark) has a water repellent film formed by hydrogen bonding of oxygen atoms of the polysiloxane main chain with silanol groups on the glass surface. There has been a drawback that it is necessary to remove dirt such as oil that interferes with the glass surface in the pretreatment step.

  Patent Document 4 proposes a method in which abrasive particles such as cerium oxide are mixed in a solution obtained by dissolving a silicone-based water repellent in an organic solvent. This water repellent agent is intended to enhance the adhesion between the water-repellent film and the glass by polishing and removing harmful substances that interfere with the adhesion of the water-repellent film with abrasive particles. However, this water repellent also requires a pretreatment step of wiping the glass surface with a wiping cloth containing ethanol before the coating operation, and there is a problem of volatilization of the organic solvent.

  Patent Document 5 discloses a method in which an abrasive is mixed into a water repellent composed of an alkylpolysiloxane, an organic solvent, and an acid. This water repellent was given the function of removing dirt such as dust and dirt adhering to the glass. However, the function of removing oil stains adhering to the glass is not clearly described, and there is a problem of volatilization of the organic solvent.

  Patent Documents 6 to 8 disclose solvent-free water repellents composed of silicone, acid, and solid particles and containing no volatile organic compound (VOC). However, solid particles such as mica, hydrocarbon wax, and plastic function to uniformly disperse the acid in the silicone and not to re-separate, and the water repellent itself does not have a dirt removing function.

  Patent Documents 9 to 12 disclose a water repellent aqueous solution composed of an organosilane quaternary ammonium compound, hydrogen peroxide, abrasive particles, and water, and describes that it has good water repellency and dirt removability. . The water used as the aqueous solution occupies an amount of 60 to 90% by weight, and it is necessary to use deionized water.

Patent Documents 13 to 15 and Patent Document 16 disclose aqueous solution type water repellents composed of amino-modified silicone oil and silanol-modified silicone oil, both of which have a function of removing dirt on the coating surface. Not.
In addition, in the patent document 17, the present applicants proposed a water repellent containing silicone oil, fine particles, a fine particle binder, an aqueous solvent and water. However, this water repellent does not have a function of removing oil stains.

Japanese Patent No. 3572757 US Pat. No. 3,579,540 Japanese Patent Publication No. 50-15473 JP-A-4-342787 US Pat. No. 5,697,991 US Pat. No. 6,676,733 US Pat. No. 6,432,181 Special table 2003-525977 gazette US Patent Publication No. 2007-0227557 US Patent Publication No. 2007-0010419 JP 2007-16201 A US Pat. No. 6,994,890 JP-A-5-301742 US Pat. No. 5,584,917 US Pat. No. 6,809,072 JP 2008-150432 A JP 2008-69365 A

  An object of the present invention is to solve the above-mentioned problems of the conventional technology, and is attached to a glass surface that can perform a water-repellent film coating operation without requiring a pretreatment step such as wiping off oil. An object of the present invention is to provide an aqueous solution type water repellent which has a function of removing dirt such as oil and is compatible with PFOS regulations and VOC emission regulations.

The present inventors have found that a water repellent having a function of removing dirt such as oil can be obtained by adding an abrasive and a dispersant to an acidic aqueous solution of an alcohol solvent containing a modified silicone oil.
The present invention has been made based on the above findings and is as follows.
(1) (A) 5 to 20% by weight of modified silicone oil covalently bonded to silanol groups exposed on the glass surface, (B) 1 to 10% by weight of polishing agent, (C) 0.2 to 2% by weight of dispersing agent (D) A water repellent having a function of removing oil stains containing 10 to 40% by weight of alcohol, (E) 5 to 30% by weight of the modified silicone oil, and (F) water as the balance.
(2) The water-repellent agent having a function of removing oil stains according to the above (1), wherein the modified silicone oil is represented by the following general formula 1 or 2 and is composed of one or more of these: Agent.

(In the formula, R is a hydroxyl group, an alkoxy group, or an amino group, and n is a number of 5 or more)

(In the formula, R is a hydroxyl group, an alkoxy group, or an amino group, m is a number of 1 or more, n is a number of 5 or more, and x is a number of 2 to 10)
(3) The water repellent having an oil dirt removing function according to any one of (1) and (2), wherein the abrasive is cerium oxide.
(4) The water repellent having an oil stain removing function according to any one of (1) to (3), wherein the dispersant is a layered silicate.
(5) The oil stain according to any one of (1) to (4) above, wherein the alcohol is methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol, and is composed of one or more of these. Water repellent with removal function.
(6) The water repellent having an oil stain removing function according to any one of the above (1) to (5), wherein the acid is sulfuric acid, phosphoric acid, or hydrochloric acid, and includes at least one of these.

  The water repellent of the present invention can comply with the PFOS regulations, VOC emission regulations, and the chemical substance emission grasp management promotion method (abbreviated as “PRTR method”), and requires a pretreatment process such as wiping oil with ethanol or the like. In spite of this, it is possible to remove dirt such as oil adhering to the glass surface by a simple application / polishing operation of a water repellent, and at the same time, provide an excellent effect of imparting good water repellency.

The modified silicone oil of the present invention can be used without any problem as long as it is a reactive silicone oil that is covalently bonded to a silanol group exposed on the glass surface to impart water repellency. As such a modified silicone oil, a reactive silicone oil having a hydroxyl group, an alkoxy group, or an amino group at both ends of the polydimethylsiloxane main chain or a part of its side chain is preferable because of its low cost. Particularly preferred is a silanol-terminated silicone oil represented by the general formula HO [Si (CH ₃ ) ₂ O] _n H, which is highly reactive with silanol groups on the glass surface. The modified silicone oil preferably has a viscosity of 30 to 3000 mm ² / s (25 ° C.), particularly a viscosity of about 30 to 100 mm ² / s, considering the ease of production of the water repellent. In order to obtain good water repellency, the modified silicone oil is used in an amount of 5 to 20% by weight, preferably 8 to 12% by weight, based on the total amount of the composition. This modified silicone oil is commercially available, for example, KF-9701, X-21-5841 manufactured by Shin-Etsu Chemical Co., Ltd., XC96-723, YF3800, YF3905 manufactured by Momentive Performance Materials Japan (combined), YF3507, BY16-873 manufactured by Toray Dow Corning Co., Ltd., PRX413, etc. can be used.

The abrasive of the present invention is for removing the oil film adhering to the glass, and if it has such a function, for example, diatomaceous earth, metal oxide, metal carbonate compound, silicate, clay, carbide, plastic, etc. Either of these is not particularly problematic, but in particular, cerium oxide having a so-called chemical / mechanical polishing function is preferably used. This cerium oxide is partially dissolved in an acidic aqueous solution, but the function of removing dirt adhering to the glass surface is not lowered.
The size of the abrasive particles is preferably in the range of 0.5 to 10 [mu] m, particularly preferably in the range of 1 to 5 [mu] m, for efficient removal of oil. This abrasive is preferably 1 to 10% by weight, particularly 2 to 4% by weight, based on the total amount of the composition, in order to efficiently remove the oil.
Cerium oxide is a commercial product available from Mitsui Mining and Smelting Co., Ltd. Mireku ^{/ MIREK R E30, E40, ES3-6} , ESS-6, manufactured by Showa Denko Co., Ltd. show Rocks / SHOROX ^R N-5, H- It is convenient to use 4 or the like.
In addition, this abrasive | polishing agent may mix and use multiple types of what was mentioned above.

As the dispersant of the present invention, those having a function of dispersing the modified silicone oil in water, for example, silicates, surfactants, synthetic thickeners, solvents and the like can be used. In particular, it is preferable to use a layered silicate represented by a chemical composition (Si _2n O _5n ) ²ⁿ − which has no influence on the water repellent effect and has a high dispersing action. Layered silicate is a talc represented by the general formula Mg ₃ Si ₄ O ₁₀ (OH) ₂ , represented by the general formula (Na, Ca) _0.33 (Al, Mg) ₂ Si ₄ O ₁₀ (OH) ₂ · nH ₂ O Montmorillonite, and hectorite represented by the general formula (Na _0.4 Mg _2.7 Li _0.3 ) Si ₄ O ₁₀ (OH) ₂ , both of which are suitable, and in particular, synthetic hectorite Magnesium silicate is preferable because it is excellent in the dispersion effect of the modified silicone oil.
Considering the dispersibility of the modified silicone oil, the amount of the dispersant is appropriately selected from the range of 0.2 to 2% by weight with respect to the total amount of the water repellent composition, but in particular, about 0.5% by weight. It is preferable that
As the layered silicate, it is convenient the use of Laponite / Laponite ^R RD made in England in Rockwood Additives Limited is a commercial product.
In addition, you may mix and use multiple types for this dispersing agent mentioned above.

As the alcohol, it is preferable to use a lower alcohol such as methanol, ethanol, isopropanol, 1-propanol, 1-butanol, 2-butanol, or a mixture of two or more thereof having high solubility in water. In particular, isopropanol is preferable. The alcohol is 10 to 40% by weight with respect to the total composition.
The alcohol constitutes an acidic aqueous solution together with acid and water to produce an alcohol-acid intermediate, so-called “half-ester”, and the silicone oil is easily and uniformly dispersed in this solution and partially dissolved. (See Patent Document 2).

  On the other hand, as the acid, an inorganic acid such as sulfuric acid, hydrochloric acid or phosphoric acid, which can easily form a half ester, can be used, and sulfuric acid is particularly preferable. The amount thereof is preferably 5 to 30% by weight, particularly 8 to 12% by weight, based on the amount of the modified silicone oil, for good dispersion and dissolution of the modified silicone oil.

  As the water, it is not particularly necessary to use deionized water, and even if tap water is used, trace amounts of element ions dissolved therein do not affect the water repellent of the present invention at all. Considering convenience and economy, tap water should be used. In the water repellent of the present invention, water is the remaining amount, but considering the ease of water repellent application, it is preferably 50 to 80% by weight based on the total amount of the composition.

The water repellent of the present invention can be prepared by adding an acid, a modified silicone oil, water, an abrasive and a dispersant to a predetermined amount of alcohol at room temperature with stirring.
The water repellent of the present invention is applied so as to be rubbed against the glass surface by being included in Kimwipe, sponge, cotton cloth or the like. When dirt such as oil adheres to the glass surface, the dirt is removed by the polishing function of the abrasive contained in the water repellent. After coating, air dry for 10 to 30 minutes and wipe with a rag. The evaluation of water repellency, oil film removal function and water washing resistance of the water repellent of the present invention will be described in detail in the following examples.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.
Table 1 shows the compositions used in Examples 1 to 4.

[Production of experimental glass]
A clean glass surface was prepared by polishing and cleaning a 40 × 50 mm slide glass using a cleaning polishing liquid having a weight ratio of cerium oxide and water of 6:94.
Then, the oil film adhesion glass surface was prepared with the following method.
Equivalent amount of wax solution for car wash machine (product name, ECO Special K) manufactured by Yokohama Oil & Fat Co., Ltd. and isoparaffin (product name, Nisseki Isosol 400) with a distillation range of 213-262 ° C manufactured by Shin Nippon Chemical Co., Ltd. Mix with. This mixed solution is applied to a clean glass slide and heated in a dryer at 110 ° C. for 4 hours.

The water repellency of the water repellent film was evaluated by the contact angle with water and the drop angle of water droplets. As a measuring device, a solid-liquid interface analyzer DropMaster300 manufactured by Kyowa Interface Science Co., Ltd. was used.
The oil stain removal function was evaluated by the change in transmittance of the glass before and after the application of the water repellent. As a measuring device, an ultraviolet-visible near-infrared spectrophotometer V-630 Spectrophotometer manufactured by JASCO Corporation was used.
Table 2 shows the water repellency evaluation after applying the water repellents of Examples 1 to 4 to a clean glass surface.

From the above results, it can be seen that the water repellent of the present invention has a good water repellent effect. Furthermore, as shown in FIGS. 1-4, since the transmittance | permeability of the glass after processing with the water repellent of each Example is substantially the same as that of a clean glass, it is excellent in the transparency of the obtained water-repellent film. I understand that
Table 3 shows the evaluation of water repellency and oil film removal function after the water repellents of Examples 1 to 4 were applied to the oil film adhesion surface.

As shown in FIGS. 5 to 8, the oil film-attached glass having a low transmittance is polished and coated with the water repellent agent of each example, and the resulting water-repellent film has a transmittance almost equal to that of clean glass. You can see that you are back. From the above results, it can be seen that the water repellent of the present invention is excellent in the water repellent effect, has an oil film removing function, and the water repellent film has good transparency.
Table 4 shows changes in the water-repellent effect after 1 hour of treatment with ultrasonic waves in an ultrasonic water bath using the water-repellent agents of Examples 1 to 4 shown in Table 3.

[Comparative Example 1]
In Example 1, except for Shin-Etsu Chemical KF9701, which is a modified silicone oil, a comparative coating liquid and a shell liquid having the same composition were prepared. This shell liquid was applied to the same oil film-attached glass as used in the experiment of Table 3. Table 5 shows the change in water repellency. Further, the change in the transmittance is shown in FIG. From the results shown in Table 5 and FIG. 9, it can be seen that the oil film adhered to the glass is completely removed by the instep liquid, and the water repellency derived from the oil film is completely eliminated. These verifications revealed that the water-repellent film shown in Table 3 was due to the knitted silicone oil included in the examples.

[Comparative Example 2]
From the data described in US Pat. No. 7,138,186, the water repellency of the commercially available product RAIN-X (registered trademark) water repellent is a contact angle of 95 to 105 ° and a falling angle (60 μL water droplet) of 20 to 25 °. It is.
From the above, the water repellent of the present invention has a water repellent effect similar to that of the commercially available RAIN-X (registered trademark) water repellent and Comparative Example 1 water repellent, and a novel aqueous solution type having an oil film removing function. It was verified that it is a water repellent.

  The water repellent of the present invention is industrially useful because it can remove dirt such as oil adhering to the glass surface and the like, particularly windshields of automobiles, etc. and at the same time impart a good water repellent effect.

The change of the glass transmittance before and behind application | coating of the water repellent of Example 1 is shown on the clean glass surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 2 is shown on the clean glass surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 3 is shown on the clean glass surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 4 is shown on the clean glass surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 1 is shown on the oil film adhesion surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 2 is shown on the oil film adhesion surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 3 is shown on the oil film adhesion surface. The change of the glass transmittance before and behind application | coating of the water repellent of Example 4 is shown on the oil film adhesion surface. The change of the surface transmittance before and behind the application | coating of the instep liquid of the comparative example 1 is shown on the oil film adhesion surface.

Claims (6)

(A) 5-20% by weight of modified silicone oil covalently bonded to silanol groups exposed on the glass surface, (B) 1-10% by weight of abrasive, (C) 0.2-2% by weight of dispersant, (D) A water repellent having a function of removing oil stains containing 10 to 40% by weight of alcohol, (E) 5 to 30% by weight of the modified silicone oil, and (F) water as the balance. The water-repellent agent having an oil stain removing function according to claim 1, wherein the modified silicone oil is represented by the following general formula 1 or 2 and is composed of one or more of these.

(In the formula, R is a hydroxyl group, an alkoxy group, or an amino group, and n is a number of 5 or more)

(In the formula, R is a hydroxyl group, an alkoxy group, or an amino group, m is a number of 1 or more, n is a number of 5 or more, and x is a number of 2 to 10)   The water repellent having an oil dirt removing function according to claim 1 or 2, wherein the abrasive is cerium oxide.   The water repellent having an oil stain removing function according to claim 1, wherein the dispersant is a layered silicate.   The said alcohol is methanol, ethanol, isopropanol, 1-propanol, 1-butanol, or 2-butanol, and consists of one or more of these. Liquid medicine. The water-repellent agent having a function of removing oil stains according to any one of claims 1 to 5, wherein the acid is sulfuric acid, phosphoric acid, or hydrochloric acid, and contains at least one of them.