JPH0559331A - Water-repellent and oil-repellent coating material and its production - Google Patents

Abstract

PURPOSE:To obtain the title material excellent in wear resistance, useful for e.g. cooking utensils such as frying pans by immersing a substrate in a nonaqueous organic solvent and by chemical adsorption of a chlorosilane-based surfactant to the substrate to form a monomolecular adsorption film on the surface of the substrate. CONSTITUTION:A wear-resistant substrate 5 is immersed in a nonaqueous organic solvent (e.g. toluene) and a chlorosilane-based surfactant having tetrachlorosilane or trichlorosilane and perfluoralkyl groups is put to chemical absorption to the surface of the substrate to form a monomolecular adsorption film 6 or built-up film each having siloxane links, thus affording the objective coating material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abrasion-resistant material which is used in places such as an inner pot of a jar rice cooker, a hot plate, a grill pot, a frying pan, etc., where water, oil and food are heavily contaminated. TECHNICAL FIELD The present invention relates to a water-repellent / oil-repellent coating material having properties and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, the surface of an inner pot of a jar rice cooker, a hot plate, a grill pan, a frying pan, etc. is coated with fluororesin through a primer, or the surface of a substrate is roughened and coated with fluororesin. The surface modification that makes the most of the water and oil repellency of the fluororesin is used.

[0003]

However, in these fluorine coating techniques, the adhesion between the substrate and the fluororesin is weak and the fluororesin peels off when the fluorine-coated surface is rubbed or scratched with a hard material such as metal. There is a problem that the substrate is exposed. Further, even when the heat cycle is repeatedly performed, the fluororesin is peeled off and the substrate is exposed in the same manner. This problem is that when used in general households, for example, when polishing rice in the inner pot of a jar rice cooker, the rice scratches the fluororesin surface and the fluororesin coating comes off during repeated use. The phenomenon described above, or the use of a metal spatula for the hot plate causes the fluororesin coating to peel off, so the current one appears to be made of a plastic material.

The present invention is intended to solve such conventional problems, and a first object thereof is to provide a water-repellent / oil-repellent coating material having excellent wear resistance.

The second and third objects are to provide second and third means for achieving the first object more reliably.

A fourth object is to provide a method for easily and uniformly producing a water / oil repellent coating material having abrasion resistance.

It is a fifth and sixth object to provide a method for achieving the fourth object more reliably.

[0008]

The first means of the present invention for achieving the first object is to provide a monomolecular adsorption film or a cumulative film having a siloxane bond on the surface of a substrate having abrasion resistance. It is a water and oil repellent coating material.

A second means of the present invention for achieving the second object is the constitution of the first means of the present invention, wherein the monomolecular adsorption film is a chlorosilane-based surfactant having a perfluoroalkyl group. It is a water and oil repellent coating material.

A third means of the present invention for achieving the third object is the construction of the first means of the present invention, wherein the cumulative film is tetrachlorosilane or trichlorosilane and a chlorosilane-based surface active agent having a perfluoroalkyl group. It is used as a water- and oil-repellent coating material.

A fourth means of the present invention for achieving the fourth object is to immerse a substrate having abrasion resistance in a non-aqueous organic solvent to chemically adsorb a chlorosilane-based surfactant on the surface of the substrate. A method for producing a water-repellent / oil-repellent coating material for forming a monomolecular adsorption film having a siloxane bond or a cumulative film.

A fifth means of the present invention for achieving the fifth object is, in the constitution of the fourth means of the present invention, a water-repellent / oil-repellent coating material comprising a non-aqueous organic solvent containing a basic compound. The manufacturing method is as follows.

A sixth means of the present invention for attaining the sixth object is the ultrasonic wave in the step of forming a monomolecular adsorption film or a cumulative film having a siloxane bond in the constitution of the fourth means of the present invention. To produce a water-repellent / oil-repellent coating material that promotes chemical adsorption.

[0014]

According to the first means of the present invention, since the monomolecular adsorption film or the accumulated film is formed at a high density on the surface of the substrate having abrasion resistance, the water and oil repellency excellent in abrasion resistance is obtained. A coating material is obtained.

According to the second means of the present invention, since the monomolecular adsorption film on the surface of the substrate is composed of a chlorosilane type surfactant having a perfluoroalkyl group, the perfluoroalkyl group has abrasion resistance at the molecular level. The monomolecular adsorption film is formed on the surface of the substrate, which has a higher density. Therefore, a coating material having more excellent water and oil repellency than that obtained by the first means of the present invention can be obtained.

According to the third means of the present invention, since the cumulative film is composed of tetrachlorosilane or trichlorosilane and a chlorosilane-based surfactant having a perfluoroalkyl group, the density of the perfluoroalkyl group is further increased and the water repellency is further improved. -A coating material having excellent oil repellency and abrasion resistance can be obtained.

According to the fourth means of the present invention, the substrate having abrasion resistance and the monomolecular adsorption film or cumulative film are chemically adsorbed. Therefore, a water-repellent / oil-repellent coating material having excellent heat resistance and abrasion resistance can be obtained as compared with a product coated with a fluororesin. Further, when the fluororesin is applied, heating and baking steps are not required, and a water-repellent / oil-repellent coating material having uniform wear resistance is produced only by the dipping step.

According to the fifth means of the present invention, since the basic compound is contained in the non-aqueous organic solvent, the dehydrochlorination reaction of the chlorosilane-based surfactant and the hydroxyl group on the surface of the substrate having abrasion resistance. Is promoted. Therefore, chemisorption is promoted and the manufacturing process of the coating material is shortened.

Furthermore, according to the sixth means of the present invention, since ultrasonic waves are used, the reaction between the chlorosilane-based surfactant and the hydroxyl group on the surface of the substrate having abrasion resistance is accelerated by vibration, and the coating material The manufacturing process is shortened and a reliable bond is obtained.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 is a sectional view of a rice cooker. 1 is an inner pot of a rice cooker, 2 is an inner lid, and 3 is a heat sink.
Reference numeral 4 is a heat source such as a heater. The inner pot 1, the inner lid 2, the heat dissipation plate 3 and the like are surface-treated as shown in FIG. 2 and coated with a water and oil repellent material having abrasion resistance. In FIG. 2, the surface of an aluminum substrate 5 that constitutes the inner pot 1 and the like is coated with ceramic. This is degreased with an organic solvent such as trichlorethylene. on the other hand,
A chlorosilane-based surfactant C ₈ F ₁₇ C ₂ H ₄ SiCl ₃ having a perfluoroalkyl group was used in an amount of 3 × 10 ^{−3 to} 5 × 10.
Prepare a solution of 80% n-hexadecane (cyclohexane, toluene, xylene, dicyclohexyl), 12% carbon tetrachloride, 8% chloroform dissolved at a concentration of about ^-2 mol / l. Then, the substrate 5 is placed in this solution.
Was immersed in a non-aqueous atmosphere at room temperature for about 2 hours, washed with chloroform for about 30 minutes, and washed with water for about 15 minutes.
Do for a minute. By this treatment, since the surface of the substrate 5 contains a hydroxyl group, the chlorosilyl group of the chlorosilane-based surfactant having a perfluoroalkyl group reacts with the hydroxyl group to form a surface.

[0022]

[Chemical 1]

The bond (1) is generated, and the monomolecular adsorption film 6 is chemically bonded to the substrate 5 and is formed with a thickness of 10 to 30 Å.

The following experiment was carried out to measure the wear resistance of the sample thus produced.

A water-repellent / oil-repellent coating material sample having a wear resistance of 5 × 5 cm ² prepared by the above method was put on a commercially available turtle brush and subjected to a total load of 2 kg at a speed of 60 rpm. After adding a predetermined number of rotations while rotating with,
Pure water and 2.5 μl of salad oil were dropped on the sample, and the contact angle of each of them was measured at room temperature. The results are shown in FIG. As a comparative example, the same measurement was performed for a glass coated with a conventional fluororesin (perfluoroalkoxy resin, hereinafter referred to as PFA), and the results are shown together. As is clear from the result of FIG. 3, the water-repellent / oil-repellent coating material having abrasion resistance of Example 1 was 800
It retains abrasion resistance up to 0 revolutions and shows superior abrasion resistance to the conventional glass coated with PFA.

The chlorosilane-based surfactant having a perfluoroalkyl group is generally represented by the following formula.

F (CF ₂ ) _m (CH ₂ ) _n SiR _q X _3-q or F (CF ₂ ) _m (CH ₂ ) _n A (CH ₂ ) _p SiR _q X _3-q (where m = 1 ~ 30, n = 0 to 15, m + n = 10 to 3
0, p = 1 to 25, q = 0 to 2, R represents an alkyl group, X represents a halogen atom or alkoxy, and A represents an oxygen atom, carboxy or dimethylsilylene. From the viewpoint of heat resistance and oil repellency, it is preferable that the number of m in the above formula is large and that the number of n is small. Practically, n = 0
-5 are preferable. By way of _{example, F (CF 2) 8 (} CH 2) 2 SiCl 3 F (CF 2) 8 (CH 2) SiCl 3 F (CF 2) 8 SiCl 3 CF 3 (CH 2) 2 SiCl 3 F (CF ₂ ) ₆ (CH ₂ ) ₂ SiCl ₃ F (CF ₂ ) ₈ (CH ₂ ) ₂ Si (CH ₃ ) Cl ₂ F (CF ₂ ) ₂₀ (CH ₂ ) ₂ SiCl ₃ is effective, but other also _{CF 3 (CH 2) 2 Si} (CH 3) 2 (CH 2) 15 SiCl 3 F (CF 2) 4 (CH 2) 2 Si (CH 3) 2 (CH 2) 9 Si
Cl ₃ CF ₃ COO (CH ₂ ) ₁₅ SiCl ₃ CF ₃ CH ₂ O (CH ₂ ) ₁₅ SiCl _{3 and the} like are also effective.

As a substrate having wear resistance, iron,
This refers to those with a ceramic coating on the surface of metal such as aluminum, those with a enamel treatment, or those with a hard alumite treatment. A silicon alkoxide, a metal alkoxide, or a mixture thereof is used as the ceramic coating material. These are represented by R ₁ M (OR ₂ ) _n as a general formula. R ₁ is an alkyl group having 0 to 3 carbon atoms, vinyl group, 3,3,3 trifluoropropyl group, γ-glycidoxypropyl group, γ-methacryloxypropyl group, and R ₂ is a hydroxyl group or methoxy group. An ethoxy isopropoxy t-butoxy substituent. M is silicon or metal.

As a typical example of this, Si (OH) ₄ , S
i (OCH ₃ ) ₄ , Ti (OCH ₃ ) ₄ , Al (OC
H ₃ ) ₃ , Zr (OCH ₃ ) ₄ , Y (OCH ₃ ) ₃ , La (O
_{CH 3) 3, Ca (OCH} 3) 2, Mn (OCH 3) 4, Sn
(OCH ₃ ) ₄ , Sr (OCH ₃ ) ₄ , Ba (OCH ₃ ) ₂ ,
_{CH 3 Si (OCH 3) 3} , SiOZr (OC 2 H 5) 6, S
iOTi (OC ₂ H ₅ ) ₆ and the like. (Embodiment 2) FIG. 4 shows an example of a hot plate.
The plate 7, which is the cooking surface of food, is manufactured by die casting of aluminum, and is provided with a translucent glass 8 such as heat-resistant tempered glass. The surface of the plate 7 is coated with a water-repellent / oil-repellent coating material having abrasion resistance as follows. First, a ceramic-coated aluminum substrate is degreased with an organic solvent such as trichlorethylene. On the other hand, a chlorosilane-based surfactant having a perfluoroalkyl group, C ₈ F ₁₇ C ₂ H ₄ SiCl
^{_3, 3 × 10 -3 ~5 × 10} -2 80% was dissolved at a concentration of about mol / l n-hexadecane (toluene, xylene, or a dicyclohexyl), 12% carbon tetrachloride, adjusting 8% chloroform solution To do. Then, the aluminum substrate is immersed in this solution in a non-aqueous atmosphere at room temperature for about 2 hours. After this immersion step, the substrate is washed with chloroform for about 30 minutes, and further washed with water for about 15 minutes. By this washing step, the surface of the aluminum substrate contains a hydroxyl group, and the chlorosilyl group of the chlorosilane-based surfactant reacts with the hydroxyl group. As a result of this reaction, the bond of (Chemical Formula 1) is generated on the surface of the aluminum substrate, and the monomolecular adsorption film is chemically bonded to the aluminum substrate to form a thickness of 10 to 30 Å.

The following experiment was conducted to measure the wear resistance of the sample thus produced.

A sample of a water-repellent / oil-repellent coating material having abrasion resistance of 5 × 5 cm ² prepared by the above-mentioned method,
Rotate at a speed of 60 revolutions per minute while applying a total load of 2 kg using a commercially available Kameko scrubbing brush. After adding a predetermined number of rotations in this way, pure water and 2.5 μl of salad oil were dropped on the sample, and the contact angle of each was measured at room temperature. The result is shown in FIG. At this time, as a comparative example, the same measurement was carried out for a sample coated with PFA, which is a conventional method, and the results are shown together.

As is clear from these results, the water-repellent / oil-repellent coating material having the wear resistance of Example 2 maintains the wear resistance up to 6000 rotations under the above conditions. On the other hand, the contact angle of the sample coated with conventional PFA sharply decreases.

(Embodiment 3) The construction of this embodiment is the same as that shown in FIG.
Is the same as. In this embodiment, the inner pot 1 and the inner lid 2 of the rice cooker are used.
The surface treatment of the heat sink 3 is performed as follows. FIG. 6 shows a manufacturing process according to this embodiment. First, the substrate 9 is degreased with an organic solvent such as trichlorethylene. On the other hand, tetrachlorosilane is added to 3 × 10 ^{−3 to} 5 ×
Prepare a solution of 80% n-hexadecane, 12% carbon tetrachloride and 8% chloroform dissolved at a concentration of about 10 ^-2 mol / l. Next, the substrate 9 is immersed in this solution in a non-aqueous atmosphere at room temperature for about 2 hours. After this immersion step, the substrate is washed with chloroform for about 30 minutes and further washed with water for about 15 minutes. By this cleaning step, the surface of the substrate 9 contains hydroxyl groups as shown in FIG. This hydroxyl group reacts with one of the four chlorine groups of tetrachlorosilane, and the other three chlorosilyl groups are replaced with hydroxyl groups by the water washing process,

[0034]

[Chemical 2]

A bond of is generated. Thus, FIG.
Substrate 9 whose monolayer as shown in (b) has abrasion resistance
Adsorbs in a form chemically bound to. Therefore, three hydroxyl groups are obtained for one hydroxyl group on the surface of the substrate 9. After that, if a chlorosilane-based surfactant having a perfluoroalkyl group is adsorbed on the substrate 9 as shown in Example 1, the bond of Chemical formula 1 is generated, and as shown in FIG. 6C. The cumulative film 10 is adsorbed.

The water-repellent / oil-repellent coating material having abrasion resistance produced by this method has a higher adsorption density of the chlorosilane-based surfactant having a perfluoroalkyl group than that shown in Example 1. Better water repellent
An oil repellent coating material can be obtained.

The heat resistance of the water / oil repellent coating material shown in Example 1 and the water / oil repellent coating material of this example were compared as follows. That is, after heating each sample at a predetermined temperature for 30 minutes, add pure water and salad oil on top of this.
2.5 μl was dropped, and the contact angle of each was measured at room temperature. The result is shown in FIG. 7. As is clear from FIG. 7, the water-repellent / oil-repellent coating material obtained by the method of this example exhibits superior performance to that of Example 1.

Tetrachlorosilane (SiCl ₄ )
In addition to SiHCl ₃ , SiH ₂ Cl ₂ , Cl- (Si
Cl ₂ O) _n -SiCl ₃ (n is an integer) and the like are also effective.

Example 4 In this example, in the step of adsorbing the chlorosilane-based surfactant having a perfluoroalkyl group of Example 1, 3 × 10 ⁻ of a basic compound, pyridine, was dipped in the solution to be dipped. ^{5 to} 5 × 10 ⁻³ mol / l was added. In this case, samples with various immersion times were prepared, and pure water and salad oil 2.
5 μl was dropped, and the contact angle of each was measured at room temperature. The result is shown in FIG. For comparison, a sample immersed for the same time as in Example 1 was also prepared,
Similarly, the results of measuring the contact angle are also shown in FIG.

As is apparent from FIG. 8, the water-repellent / oil-repellent coating material obtained by the method shown in this example is more excellent than the water-repellent / oil-repellent coating material obtained by the method according to Example 1. It can be seen that the adsorption time of the chlorosilane-based surfactant having a perfluoroalkyl group is fast, which is an effective method for shortening the time required for the dipping process.
This is because the dehydrochlorination reaction that occurs when a chlorosilane-based surfactant having a perfluoroalkyl group is adsorbed on a substrate is accelerated, and the rate at which a siloxane bond is generated is increased. It is believed that the rate of surfactant adsorption is increased.

Example 5 In this example, the step of adsorbing the chlorosilane-based surfactant having a perfluoroalkyl group of Example 1 is immersed while applying ultrasonic waves. In this case, samples with various immersion times were prepared, 2.5 μl of pure water and salad oil were dropped on the water-repellent / oil-repellent coating material of the prepared samples, and the contact angle of each was measured at room temperature. The result is shown in FIG. Further, at this time, for comparison, the contact angle of the sample immersed in the method of Example 1 for the same period of time was also measured and the results are shown together.

As is apparent from FIG. 9, the water-repellent / oil-repellent coating material obtained by the method of this example is more chlorosilane having a perfluoroalkyl group than the water-repellent / oil-repellent coating material of Example 1. It can be seen that the adsorption time of the system surfactant is fast, and this is an effective method for shortening the time of the dipping process.

It can be easily inferred that the immersion step time can be further shortened by combining the method shown in Example 3 and the method shown in Example 4.

[0044]

As described above, according to the first means of the present invention, a water-repellent / oil-repellent coating in which a monomolecular adsorption film having a siloxane bond or a cumulative film is provided on the surface of a substrate having abrasion resistance. By using the material, a water-repellent / oil-repellent coating material having excellent abrasion resistance as compared with the conventional example can be obtained.

According to the second means of the present invention, since the monomolecular adsorption film is composed of a chlorosilane-based surfactant having a perfluoroalkyl group, the substrate surface where the perfluoroalkyl group has abrasion resistance at the molecular level. Since the monomolecular adsorption film is formed on the upper side with high density, a coating material having more excellent water and oil repellency and abrasion resistance can be obtained.

According to the third means of the present invention, since the cumulative film is composed of tetrachlorosilane or trichlorosilane and a chlorosilane-based surfactant having a perfluoroalkyl group, the density of the perfluoroalkyl group is further increased, A coating material having more excellent water repellency and oil repellency and abrasion resistance can be obtained.

According to the fourth means of the present invention, a substrate having abrasion resistance is immersed in a non-aqueous organic solvent to chemically adsorb a chlorosilane-based surfactant on the surface of the substrate,
By using a method for producing a water-repellent / oil-repellent coating material that forms a monomolecular adsorption film having a siloxane bond or a cumulative film, the substrate having abrasion resistance and the monomolecular adsorption film or cumulative film can be chemically adsorbed. It is possible to provide a manufacturing method capable of obtaining a water-repellent / oil-repellent coating material having excellent abrasion resistance as compared with a product coated with a fluororesin. Further, when coating a fluororesin, drying and baking steps are required, but in the manufacturing method according to the present invention, these steps are unnecessary, and the number of steps can be greatly reduced,
A water-repellent / oil-repellent coating material with uniform properties can be created only by the dipping process.

According to the fifth means of the present invention, in addition to the constitution of the fifth means of the present invention, by adding a basic compound to a non-aqueous organic solvent, the chlorosilane-based surfactant and the substrate surface are Since the dehydrochlorination reaction of the hydroxyl group is promoted, chemisorption is promoted and the production process is shortened as compared with the fourth means of the present invention.

According to the sixth means of the present invention, since the chemical adsorption is promoted by using ultrasonic waves, the reaction between the chlorosilane type surfactant and the hydroxyl group on the surface of the substrate having abrasion resistance is vibrated. It is possible to obtain a water-repellent / oil-repellent coating material which is accelerated by the above, has a shortened manufacturing process, and has wear resistance capable of reliable bonding.

[Brief description of drawings]

FIG. 1 is a sectional view of a rice cooker showing a configuration of a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a surface state of the embodiment.

FIG. 3 is a characteristic diagram showing the relationship between the contact angle between water and oil and the number of wears in the same example.

FIG. 4 is an external perspective view of a hot plate showing a second embodiment of the present invention.

FIG. 5 is a characteristic diagram showing the relationship between the contact angle between water and oil and the number of wears in the same example.

FIG. 6 is a configuration diagram showing a surface state of the example.

FIG. 7 is a characteristic diagram showing the relationship between the contact angle between water and oil and the wear frequency of the coating material according to the third embodiment of the present invention.

FIG. 8 is a characteristic diagram showing the relationship between the contact angle between water and oil and the immersion time of the coating material according to the fourth embodiment of the present invention.

FIG. 9 is a characteristic diagram showing the relationship between the contact angle between water and oil and the immersion time of the coating material according to the fifth embodiment of the present invention.

[Explanation of symbols]

 1 Inner pot of rice cooker 2 Inner lid of rice cooker 3 Heat sink of rice cooker 5.9 Substrate 6 Monomolecular adsorption film 7 Hot plate plate 10 Cumulative film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Norio Mino, 1006 Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (72) Kazumi Ogawa, 1006, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Industrial (72) Inventor Hidenori Kawanishi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Atsushi Asamu, 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A water-repellent / oil-repellent coating material in which a monomolecular adsorption film having a siloxane bond or a cumulative film is provided on the surface of a substrate having abrasion resistance. 2. The water / oil repellent coating material according to claim 1, wherein the monomolecular adsorption film comprises a chlorosilane-based surfactant having a perfluoroalkyl group. 3. The water / oil repellent coating material according to claim 1, wherein the cumulative film comprises tetrachlorosilane or trichlorosilane and a chlorosilane-based surfactant having a perfluoroalkyl group. 4. A substrate having abrasion resistance is immersed in a non-aqueous organic solvent to chemically adsorb a chlorosilane-based surfactant on the surface of the substrate to form a monomolecular adsorption film or cumulative film having a siloxane bond. A method for producing a water-repellent / oil-repellent coating material. 5. The method for producing a water / oil repellent coating material according to claim 4, wherein the non-aqueous organic solvent contains a basic compound. 6. The method for producing a water / oil repellent coating material according to claim 4, wherein in the step of forming a monomolecular adsorption film or a cumulative film having a siloxane bond, the chemical adsorption is promoted by using ultrasonic waves. ..