JP2000314000A - Fluorine compound containing composite plating solution and formation of composite plated coating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the falling of pitch fluoride as to a composite plating coating film contg. pitch fluoride. SOLUTION: A composite plating soln. contains metallic salt, pitch fluoride treated with a diamine compd. and a hexafluoroethyleneperfluoroalkoxyvinyl ether copolymer, where the diamine compd. is the one, e.g. shown by the formula. Moreover, in the formula, R denotes 1 to 3C alkyl group, and (n) denotes the integers of 2 to 5, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a plating solution and a method for forming a plating film, and more particularly to a composite plating solution and a method for forming a composite plating film.

[0002]

2. Description of the Related Art As a film for imparting water repellency to a metal or resin substrate, a film made of a fluorine-based resin such as polytetrafluoroethylene is known. However, since the fluororesin hardly softens and flows, it is difficult to form a uniform coating on the inner surface of a fine metal tube or the surface of a member having a complicated uneven shape. Therefore, a composite plating film having water repellency has been proposed as a film capable of imparting uniform water repellency to the surface of a member having a complicated shape or the like.

For example, Japanese Patent Application Laid-Open No. Hei 7-26397 discloses a composite plating film in which fine pitch fluoride particles are dispersed and eutectoid in a metal base material layer. This composite plating film has high water repellency because it contains fine pitch fluoride particles exhibiting high water repellency in the metal base material layer, and can be formed by a conventional plating method, and thus has a complicated shape and the like. Can be formed even on the surface of a member having the same.

However, when a frictional force is applied to the surface of the composite plating film, pitch fluoride fine particles dispersed in the metal base material layer easily fall off. Therefore, the composite plating film may contaminate the surrounding environment due to fine pitch fluoride particles that have fallen from it, and may exhibit high water repellency in the initial stage of formation, but the water repellency gradually decreases when subjected to friction. It is expected to do.

[0005] An object of the present invention is to suppress falling off of fluoride pitch in a composite plating film containing pitch fluoride.

[0006]

The composite plating solution according to the present invention contains a metal salt, pitch fluoride treated with a diamine compound and a hexafluoroethylene perfluoroalkoxy vinyl ether copolymer. here,
The diamine compound is, for example, one represented by the following general formula (1). In the formula, R represents an alkyl group having 1 to 3 carbon atoms, and n represents an integer of 2 to 5, respectively.

[0007]

Embedded image

The diamine compound represented by the general formula (1) is, for example, N, N-dimethyl-1,3-propanediamine.

[0009] The composite plating solution is, for example, 10 to 50 g / fluoride pitch treated with a diamine compound.
1, 10 to 50 g / l of hexafluoroethylene perfluoroalkoxy vinyl ether copolymer.

The method for forming a composite plating film according to the present invention is a method for forming a composite plating film on a substrate. This forming method is a step of preparing a composite plating solution containing a metal salt, pitch fluoride and hexafluoroethylene perfluoroalkoxy vinyl ether copolymer treated with a diamine compound, and immersing the substrate in the composite plating solution, Applying a plating method to the base material. The method of forming such a composite plating film is as follows.
For example, the method further includes a step of heat-treating the composite plating film obtained by the plating method.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The composite plating solution of the present invention comprises an aqueous solution in which a metal salt is dissolved and pitch fluoride and a hexafluoroethylene perfluoroalkoxy vinyl ether copolymer are dispersed.

The metal salt used in the present invention is a material for forming a metal base material layer of a composite plating film, for example, nickel, copper, zinc, tin, iron, lead, cadmium,
Noble metals such as chromium, gold and silver, and salts of alloys thereof are used. Examples of such metal salts include chloride salts such as nickel chloride, carbonate salts such as nickel carbonate, and sulfamate salts such as nickel sulfamate.

Fluorinated pitch is a known substance which can be produced by fluorinating pitch using fluorine gas, and is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-275190.

The pitch used for producing such a fluorinated pitch generally has a layer structure in which aromatic condensed six-membered ring planes are laminated while being cross-linked by an aliphatic hydrocarbon group such as methylene. Usually, petroleum distillation residue,
Naphtha pyrolysis residue, ethylene bottom oil, coal liquefied oil and petroleum or coal heavy oil such as coal tar are distilled to remove low boiling components having a boiling point of less than 200 ° C.,
These are those synthesized by condensation of naphthalene or the like, and those further subjected to heat treatment or hydrogenation treatment. Specifically, isotropic pitch, mesophase pitch, hydrogenated mesophase pitch, mesocarbon microbeads composed of mesophase spheres formed after distilling petroleum-based or coal-based heavy oil to remove low-boiling components, etc. Can be mentioned.

When producing the desired fluorinated pitch using the above-mentioned pitch, the pitch is directly reacted with fluorine gas. The temperature at the time of this reaction is preferably set to about 0 to 350 ° C., and more preferably to the softening point of the pitch or lower. In addition, the fluorine gas pressure during the reaction is not particularly limited, but is generally preferably set to 0.07 to 1.5 atm. Note that, as the fluorine gas, a gas diluted with an inert gas such as nitrogen, helium, argon, or neon may be used.

Preferred fluorinated pitches usable in the present invention substantially consist of carbon atoms and fluorine atoms, and have an atomic ratio of fluorine to carbon (fluorine / carbon) of, for example, 0.5 to 1. It is about 8 powders. Such a fluorinated pitch exhibits the following characteristics (a), (b), (c) and (d).

(A) In powder X-ray diffraction, 2θ = 13
A peak with the maximum intensity is shown near ゜, and a peak with a smaller intensity than the maximum intensity peak is shown near 2θ = 40 °. (B) 290.0 ± 1.
The peak corresponding to CF at 0 eV and 292.5 ± 0.
A peak corresponding to CF ₂ is shown around 9 eV, and the ratio of the intensity of the peak corresponding to CF ₂ to the peak corresponding to CF is about 0.15 to 1.5. (C) A film can be formed by vacuum distillation. (D) The contact angle with water at 30 ° C. is 141 ± 8.
°.

In the present invention, a fluorinated pitch in the form of a transparent resin can also be used. The pitch of the fluorinated pitch in the form of a transparent resin is, for example, about 0.1 to 3 ° C./min, preferably 0.5 to 1.5 ° C. in a fluorine gas atmosphere.
The temperature is raised to about 250 to 400 ° C. at a rate of about 250 ° C./minute, and the temperature is raised for a predetermined time, for example, about 1 to 18 hours, preferably
It can be produced by reacting for about 12 hours. According to this method, for example, a fluorinated pitch in the form of a transparent resin having the following characteristics can be obtained.

F / C atomic ratio: 1.5 to 1.7 Light transmittance (250 to 900 nm): 90% Molecular weight: 1,500 to 2,000 Softening point: 150 to 250 ° C.

The pitch fluoride may be used in combination with the powdery powder and the transparent resinous pitch.

The pitch fluoride used in the present invention is obtained by treating the above-mentioned pitch fluoride with a diamine compound, that is, by reacting the above-mentioned pitch fluoride with a diamine compound. Has a surfactant activity. The diamine compound used here is not particularly limited as long as it has two amino groups, and is a variety of known compounds. Preferably, the diamine compound is represented by the following general formula (1). .

[0022]

Embedded image

In the general formula (1), R represents an alkyl group having 1 to 3 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group or an iso-propyl group. When the carbon number of the alkyl group represented by R exceeds 3, the steric hindrance may make it difficult for the diamine compound to react with the fluorinated pitch. On the other hand, n has shown the integer of 2-5. When n is 1, the diamine compound becomes unstable and handling may be difficult. Conversely, if it exceeds 5, it may be difficult to obtain a fluorinated pitch having a high surface activity.

Particularly preferred among the diamine compounds represented by the general formula (1) are N, N-dimethyl-, wherein the alkyl group represented by R is a methyl group and n is 3.
1,3-propanediamine.

When reacting the above-mentioned pitch fluoride and the diamine compound, usually, a solution is prepared by dissolving both in a suitable solvent, and both solutions are mixed to react the pitch fluoride with the diamine compound. Let it. The solvent for dissolving the pitch fluoride and the diamine compound is not particularly limited as long as both can be dissolved, and for example, alcohols, furans, and the like can be used.

The reaction temperature at the time of reacting the pitch fluoride and the diamine compound is usually preferably set at room temperature to 100 ° C., more preferably at 10 to 40 ° C., and more preferably at 10 to 20 ° C. More preferably, When the reaction temperature exceeds 100 ° C., the product may be tarred. In the above reaction, it is preferable to set the amount of the diamine compound to be substantially equivalent to the pitch fluoride. However, the amount of the diamine compound to be used is generally larger than that of the pitch fluoride. It is preferable to set

Further, the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer used in the present invention is a known fluororesin containing a methoxy group, an ethoxy group or the like as an alkoxy group. -2CR ".

The composite plating solution of the present invention is prepared by preparing an aqueous solution in which the above-mentioned metal salt is dissolved in water, and in this aqueous solution, pitch fluoride treated with the above-mentioned diamine compound (hereinafter, referred to as “pitch fluoride”).
It can be produced by uniformly and finely dispersing a modified fluorofluorinated pitch) and a hexafluoroethylene perfluoroalkoxy vinyl ether copolymer. The concentration of the metal salt in the aqueous solution prepared here is usually preferably set to 30 to 60% by weight. When the concentration of the metal salt is less than 30% by weight, it may be difficult to form a metal base material layer having a required thickness. Conversely, 6
If it exceeds 0% by weight, the viscosity of the composite plating solution will be high, and it may be difficult to maintain the uniformity of the composite plating solution.

The content of the modified fluorinated pitch in the composite plating solution of the present invention is usually preferably set to 10 to 50 g / l, more preferably 12 to 38 g / l. The content of the modified fluorinated pitch is 10 g /
If it is less than 1, the dispersibility of the composite plating solution may not be sufficiently increased. Conversely, if it exceeds 50 g / l,
The composite plating film may be discolored and the appearance of the composite plating film may be impaired.

Further, the content of the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer in the composite plating of the present invention is usually preferably set to 10 to 50 g / l, and more preferably to 12 to 38 g / l. Is more preferred. The content of the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer is 10 g /
If it is less than 1, there is a possibility that dropping of the fluoride pitch from the composite plating film cannot be effectively suppressed.
Conversely, if it exceeds 50 g / l, the dispersibility of the composite plating solution may be insufficient.

The total amount of the modified fluorinated pitch and the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer contained in the composite plating solution of the present invention is usually preferably set to 40 to 60 g / l, 45-
It is more preferably set to 55 g / l, and particularly preferably set to 50 g / l.

The composite plating solution of the present invention may contain, in addition to the various components described above, various additives which can be usually added to the plating solution, such as a primary brightener, a secondary brightener, and a pigment for coloring the composite plating film. It may contain an agent.

As described above, the composite plating solution of the present invention comprises a modified pitch fluoride in an aqueous solution in which the above-mentioned metal salt is dissolved.
It can be produced by adding and mixing and dispersing a hexafluoroethylene perfluoroalkoxy vinyl ether copolymer and other additives. At this time, the modified fluorinated pitch and the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer can be used as a modified fluorinated pitch itself without adding a surfactant which may be a cause of inhibiting the water repellency of the composite plating film. It can be uniformly dispersed in an aqueous solution in the form of fine particles due to its surface activity.

When a composite plating film is formed using the above-mentioned composite plating solution, a predetermined base material is immersed in the composite plating solution prepared as described above, and the plating method is applied to the base material. Apply.

At this time, in order to disperse the fine particles of the modified fluorinated pitch and the hexafluoroethylene perfluoroalkoxyvinyl ether copolymer evenly and uniformly in the metal base material layer constituting the composite plating film, a composite plating solution is used. Is preferably sufficiently stirred. The stirring method is not particularly limited, but various known methods such as screw stirring and stirring with a magnetic stirrer can be adopted. In addition, as the plating method, a known electroless plating method or electrolytic plating method can be adopted. The plating conditions at this time can be set in the same manner as those employed in a general composite plating method. Specifically, the solution temperature, pH value, current density, and the like can be appropriately set according to the properties of the base material, the type of the composite plating solution, and the like.

In such a method of forming a composite plating film, the metal salt contained in the composite plating solution is reduced to a metal, and the metal is electrodeposited on the substrate. Thereby, a metal base material layer is formed on the base material. At this time, the modified pitch fluoride and the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer contained in the composite plating solution are co-deposited at the same time, and are uniformly dispersed in the form of fine particles in the metal base material layer. Thereby, a target composite plating film is formed on the base material.

It is preferable that the composite plating film thus formed is further heat-treated. By performing such a heat treatment, the water repellency of the composite plating film can be further increased. In this heat treatment, it is usually preferable to set the processing temperature to 150 to 300 ° C. and the processing time to 30 minutes to 2 hours. When the heat treatment temperature is lower than 150 ° C., it is necessary to set a long heat treatment time in order to obtain a sufficient heat treatment effect, which is not efficient. Conversely, if the processing temperature exceeds 300 ° C., the composite plating film may be deteriorated.

The substrate to which such a composite plating film is applied generally needs to be provided with water repellency by the composite plating film, and is, for example, as follows.

A member requiring rust prevention. For example, various building materials and ship materials. ◎ Materials that may cause inconvenience if snow or icing occurs. For example, ice plates, transmission lines, parabolic antennas, etc. ◎ Materials that are required to have stain resistance, oil repellency, heat scorch, etc. For example, the inner surface of a dishwasher, the inner surface of a washing machine tank, a range hood, a ventilation fan, a table stove top plate, a table stove juice saucer, an oven plate, a grilled iron plate, a roster,
Genghis Khan hot pot, frying pan, goku, grill, gas stove, oven, microwave oven, rice cooker, barbecue stove, hot plate, pot, oven toaster, electric pot, electromagnetic induction heater, system kitchen top plate, sink, faucet, Mixing faucet, gas pipe inner and outer coats, etc. ◎ Materials requiring dew condensation prevention. For example, bathroom interior materials. ◎ Materials requiring water repellency and antifouling properties. For example, a bathtub. ◎ A member that is inconvenient if thermal conductivity is impaired. For example,
Exhaust top, heat exchanger fins, carbon fiber surface coat, carbon material coat, LNG vaporizer evaporator plate, copy roller, etc. ◎ Materials requiring mold release properties. For example, a mold. ◎ A member that requires water repellency and ice repellency. For example, parts for aircraft and helicopters. ◎ Materials that require slidability. For example, gas valve inner surface coating. ◎ A member that requires good liquid drainage. For example, liquid supply tubes such as micro syringe needles, pipettes, dispensers, separating funnels and general nozzles.

The specific material constituting such a base material is not particularly limited as long as the electroplating method can be applied. Examples thereof include copper, stainless steel, general steel, aluminum and aluminum. Various metals such as alloys, and carbon materials such as carbon plates and graphite plates.

In order to enhance the adhesion of the substrate to the composite plating film, the portion where the composite plating film is to be formed may be roughened in advance into fine irregularities. As such a method of surface roughening, a method of chemically treating a substrate using an aqueous solution of an etching agent such as hydrofluoric acid, ammonium fluoride, or hydrochloric acid, or a shot blast treatment,
Mechanical processing methods such as sandblasting, liquid honing, and polishing using steel wire or steel wool can be employed.

Further, the substrate may be provided with a base plating layer such as a nickel plating layer or a copper plating layer on the surface on which the composite plating film is formed.

The composite plating film as described above can exhibit good water repellency because of fine particles of pitch fluoride and hexafluoroethylene perfluoroalkoxyvinyl ether copolymer contained therein. Further, in the composite plating film, even if frictional force is applied to the surface, fine particles of pitch fluoride are less likely to fall off. As a result, the composite plating film is less likely to contaminate the surrounding environment even when subjected to friction, and can maintain good water repellency for a long period of time. The reason for this is not clear, but the fine particles of the hexafluoroethylene perfluoroalkoxyvinyl ether copolymer dispersed in the metal base material layer together with the pitch fluoride are stably dispersing the fine pitch fluoride particles in the metal base material layer. It is thought that the effect of holding can be exhibited.

Further, since this composite plating film does not contain a surfactant, the occurrence of unevenness and discoloration are small, and the finished condition, that is, the appearance is good.

[0045]

EXAMPLES Production Example (Production of Modified Fluorinated Pitch) Pitch Fluoride (Prototype name "N-7-
25 ") Dissolve 100 g in 200 ml ethanol,
A pitch fluoride solution was obtained. Further, 5 g of N, N-dimethyl-1,3-propanediamine was dissolved in 200 ml of ethanol to obtain a diamine compound solution.

When the obtained pitch fluoride solution and the diamine compound solution were mixed at room temperature, the pitch fluoride and N, N-dimethyl-1,3-propanediamine reacted while generating heat, and a black-brown solid was formed. (Modified pitch fluoride)
was gotten.

Examples 1 to 3 A nickel plating aqueous solution containing 360 g / l of nickel sulfamate, 45 g / l of nickel chloride and 30 g / l of boric acid was prepared. The modified fluorinated pitch and hexafluoroethylene perfluoroalkoxy vinyl ether copolymer obtained in Production Example (trade name "AD-2CR" of Daikin Industries, Ltd .: "PF-2" in Table 1 below)
A ") is added at a ratio shown in Table 1 so that the total amount becomes 50 g / l, uniformly dispersed in fine particles, and nickel carbonate is appropriately added to adjust the pH to 4.2. A composite plating solution was obtained.

The plate-like substrate was immersed in the obtained composite plating solution and subjected to electrolytic plating to form a composite plating film on the plate-like substrate. Here, the size is 5.
A stainless steel plate (SU) having a mirror surface of 0 cm x 5.0 cm
S403), and plating conditions were set as follows.

Current density: 3 A / dm ² Bath temperature: 50 ° C. Coating thickness: 10 μm

Examples 4 to 6 The composite plating films obtained in Examples 1 to 3 were heat-treated.
The heat treatment conditions here were set at 300 ° C. for 30 minutes.

Comparative Example 1 A composite plating solution containing only the modified fluorinated pitch obtained in the Production Example at a ratio of 50 g / l was prepared without using the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer. In the same manner as in cases Nos. 1 to 3, a composite plating film was formed.

Comparative Example 2 The composite plating film obtained in Comparative Example 1 was heat-treated. The heat treatment conditions here were set at 300 ° C. for 30 minutes.

Evaluation With respect to the composite plating films obtained in the respective Examples and Comparative Examples, the contact angle and the falling angle when distilled water was dropped were measured, and the falling test and the burning test of the pitch fluoride powder were performed. Carried out. Further, the finished condition (appearance) of the composite plating film was evaluated. The contact angle and falling angle are
Measurements were made for the composite plating film immediately after formation (immediately after formation) and for the case where the surface was strongly wiped 50 times using “Kimwipe” (trade name of Jujo Kimberly Co., Ltd.) (after friction treatment). In addition, the burning test was performed on the composite plating film after the friction treatment. The measuring method and the test method are as follows. Table 1 shows the results.

(Contact angle) The contact angle was measured using a contact angle meter ("CA-A type" manufactured by Kyowa Interface Science Co., Ltd.).

(Falling Angle) A water drop having a diameter of 3 mm was dropped on the contact angle meter used in the measurement of the contact angle, and the dropping surface was gradually inclined from the horizontal plane.

(Detachment Test of Fluoride Pitch Powder) When the composite plating film was subjected to the friction treatment as described above, the adhesion state of the fluorinated pitch powder adhered to the Kimwipe was visually determined. The evaluation criteria are as follows. ：: No adhesion. Δ: There is slight adhesion. X: There is a large amount of adhesion.

(Scorching Test) A mixed solution of egg, soy sauce and sugar was prepared and dropped onto the composite plating film. Then, the composite plating film was heated to 250 ° C. to cause the mixture to scorch, and the adhered state was visually evaluated. The evaluation criteria are as follows. ：: no sticking adhesion. Δ: There is slight sticking adhesion. X: There is remarkable sticking.

(Finish Condition) The composite plating film was visually observed to determine the presence or absence of unevenness and discoloration. The evaluation criteria are as follows. ：: No unevenness or discoloration. Δ: There is slight unevenness and discoloration. X: There is clear unevenness and discoloration.

[0059]

[Table 1]

[0060]

Since the composite plating solution of the present invention contains hexafluoroethylene perfluoroalkoxy vinyl ether copolymer together with fluorinated pitch treated with a diamine compound, it exhibits high water repellency, A composite plating film with less falling off can be realized.

In the method for forming a composite plating film according to the present invention, since the above-mentioned composite plating solution according to the present invention is used, a composite plating film exhibiting high water repellency and having a small amount of pitch fluoride fluoride falling off is obtained. Can be formed.

Claims (6)

[Claims] 1. A composite plating solution containing a metal salt, pitch fluoride treated with a diamine compound, and a hexafluoroethylene perfluoroalkoxy vinyl ether copolymer. 2. The method according to claim 1, wherein the diamine compound is represented by the following general formula (1):
The composite plating solution according to claim 1, which is represented by: Embedded image (Wherein, R represents an alkyl group having 1 to 3 carbon atoms, and n represents 2 to
An integer of 5 is shown. ) 3. The method according to claim 1, wherein the diamine compound is N, N-dimethyl-
The composite plating solution according to claim 2, which is 1,3-propanediamine. 4. The composite plating solution according to claim 1, comprising 10 to 50 g / l of the pitch fluoride and 10 to 50 g / l of the hexafluoroethylene perfluoroalkoxy vinyl ether copolymer. 5. A method for forming a composite plating film on a substrate, comprising a metal fluoride, pitch fluoride treated with a diamine compound and a hexafluoroethylene perfluoroalkoxy vinyl ether copolymer. A method for forming a composite plating film, comprising: preparing a solution; and immersing the substrate in the composite plating solution and applying a plating method to the substrate. 6. The method for forming a composite plating film according to claim 5, further comprising a step of heat-treating the composite plating film obtained by said plating method.