JP2561435B2 - Manufacturing method of surface hydrophobic metal material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface treatment method for hydrophobizing the surface of a metal material such as metal powder, and more particularly to a method for producing a highly hydrophobized metal material.

[0002]

2. Description of the Related Art Inorganic materials such as metal powder, carbon black and ceramic powder are organic materials such as pigment plastics used for paints and inks, magnetic tapes, conductive paints, rubbers, plastic magnets, semiconductor encapsulation resins, etc. It is widely used industrially as a functional property-imparting material for strengthening mechanical strength, imparting conductivity, and magnetic shielding.

However, the surface of an inorganic substance is essentially hydrophilic, and when it is used in combination with an organic material,
The interfacial compatibility with organic materials and the dispersibility of inorganic materials have a great influence on the physical properties and functionality of the final material. For this reason, in order to make the surface of the inorganic substance organic and hydrophobic,
Treatment with a coupling agent such as a silane-based coupling agent, an aluminum-based coupling agent, a phosphoric acid-based coupling agent has been industrially performed, and some effects have been obtained. However, it cannot be said that the high-performance composite materials are sufficiently brought out by the surface treatment method using these coupling agents. The reason for this is that the affinity between the surface of the inorganic material and the coupling agent is small.

Silane-based coupling agents have little effect on metals and carbon black, and other coupling agents tend to be released from the inorganic surface by hydrolysis. Another cause is that the organic groups bonded to these coupling agents are not considered to be sufficiently integrated with the organic resin to be composited. Therefore, in the conventional method, it is impossible to make the surface of the inorganic material highly hydrophobic.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a surface-hydrophobic metallic material which is highly hydrophobic on the surface of the metallic material and can be widely used as a highly functional composite material.

[0006]

The present invention applies the fact that silyl isocyanate has an extremely strong affinity or reactivity with the hydroxyl groups and / or adsorbed water on the surface of the metal material, and the silyl isocyanate and NCO on the surface of the metal material are applied. A hydrophobic compound having a reactive group is bonded to the surface of the metal material to make it highly hydrophobic.

The present invention comprises a silyl isocyanate having a Si-NCO bond, a silanol group and a hydroxyl group in the molecule,
A surface hydrophobic metal characterized in that a reaction product with a hydrophobic compound having at least one group selected from the group consisting of a mercapto group, an amino group, an epoxy group and a carboxyl group is allowed to act on the surface of a metal material. A method of manufacturing a material is provided.

[0008]

The present invention will be described in detail below. As the metal material used in the present invention, in addition to those usually used as pigments and fillers, those used as conductive pigments, conductive fillers, etc., and magnetic powder used as magnetic recording material material Etc., such as Al, As, Bi, C
a, Cd, Co, Cr, Cu, Fe, Mg, Ni, P
Examples of the metal include b, Sb, Si, Ti, Zn and the like, which are mainly composed of simple elements, a mixture of metals such as steel and stainless steel and other elements, and alloys thereof. It may have any shape such as a scaly shape, a fibrous shape, a plate shape, or a needle shape.

As the silylisocyanate which is the first component of the surface treatment agent bonded to the above metal material, R _n Si (NC
O) _4-n , n is 0, 1, 2, 3 and R is an alkyl group having 1 or more carbon atoms, an alkoxy group, an aryl group, a vinyl group or the like. The amount of silylisocyanate used varies depending on the surface area of the metal material and the type of silylisocyanate, but is usually 0.1 to 10% by weight with respect to the metal material.
It is a degree. As the hydrophobic compound which is the second component of the surface treatment agent, there are those having the following groups.

(1) Silanol group General formula --R _n Si (OH) _4-n , R may be an alkyl group or the like, or may be absent. Any hydrophobic compound having n = 3,2,1,0 may be used, and α (l) dihydroxydimethylpolysiloxane and the like can be typically mentioned.

(2) The hydrophobic compound having a hydroxyl group —OH may be any compound having a hydroxyl group other than the above silanol group, but a phenol resin or the like is preferable.

(3) Typical examples of the hydrophobic compound having a mercapto group —SH include γ-mercaptopropyltriethoxysilane.

(4) The hydrophobic compound having an amino group —NH ₂ is preferably an amino resin such as urea resin, melamine resin or guanamine resin.

(5) Epoxy group

Embedded image Hydrophobic compounds having (n is an integer of 0 or more) are called epoxy resins, polycondensates of bisphenols and epichlorohydrin, and halogenated resins, polyhydric alcohols, dimer acids, trimers. Representative examples thereof include a resin obtained by reacting an acid and novolac with epichlorohydrin to introduce an epoxy group, a resin obtained by introducing an epoxy group into hydrogen peroxide with hydrogen peroxide, and an alicyclic epoxy resin.

(6) The hydrophobic compound having a carboxyl group —COOH is preferably stearic acid.

The above hydrophobic compounds may be used alone or in combination. It may also be a copolymer of these compounds. Silanol group, hydroxyl group, mercapto group,
It may be a hydrophobic compound having an epoxy group or a carboxyl group alone, may have various types of these groups, or may have a large number of these groups.

As a method for treating the surface of the metal material with the silyl isocyanate and the hydrophobic compound, there are the following methods. A reaction product is obtained by reacting silyl isocyanate with a hydrophobic compound. That is, 2 equivalents or less, preferably 1 equivalent of the hydrophobic compound is mixed with 1 mol of silylisocyanate, and the mixture is heated and reacted as necessary to produce a reaction product. In this reaction, a solvent having no active hydrogen that reacts with isocyanate, such as ester, ketone, ether or hydrocarbon, can be used as a solvent. A method such as a dry method or a wet method can be used for treating the surface of the metal material with the reaction product thus obtained. Alternatively, the metal material, the silyl isocyanate, and the hydrophobic compound may be mixed at the same time, and the reaction product of the silyl isocyanate and the hydrophobic compound may act on the surface of the metal material. For example, the surface treatment is performed in the presence or absence of a solvent while forcibly stirring the metal material with a V blender, a Henschel mixer, or the like. Specifically, a dry method of spraying the reaction product alone or a solvent not containing active hydrogen, such as an ester, a ketone, an ether, or the reaction product dissolved in a hydrocarbon, for treating the metal material, and activating the metal material. A commonly used method such as a wet method of dispersing in a solvent containing no hydrogen to form a slurry and adding silylisocyanate thereto can be employed. Alternatively, the metal material may be treated with the silyl isocyanate and the hydrophobic compound in the solvent or in the absence of the solvent.

The determination of the hydrophobicity of the metal material treated by the above method is simply carried out by adding the metal material to a two-phase system solution of water and an insoluble organic solvent, stirring the mixture vigorously, and then dispersing the metal material in the dispersed phase. Can be done in the usual way of observing. For example, a two-phase system solution consisting of 20 ml of n-heptane and 80 ml of water is placed in a settling tube with a sealed capacity of 140 ml, to which 1.0 g of a metal material whose hydrophobicity is to be determined is added and shaken vigorously. Let stand and observe the dispersed state of the metal material. The completely hydrophobized metal material is stably dispersed in the n-heptane phase, and the incompletely hydrophobized metal material easily moves to the water layer.

[0019]

EXAMPLES The method of the present invention will be specifically described below based on examples. Example 1. In a reactor equipped with a reflux pipe, Organix SI310 (Matsumoto Pharmaceutical Co., Ltd. methylsilylisocyanate CH ₃ Si (NCO) ₃ ) 169 parts by weight YD128 (Toho Kasei Co., Ltd. epichlorohydrin, bisphenol A type epoxy resin, epoxy equivalent) 186) 1
86 parts by weight of toluene 100 parts by weight were charged and refluxed at 120 ° C. for 1 hour to obtain a reaction product. 100 parts by weight of 316L stainless steel flakes having a thickness of 0.3 μm and an average diameter of 20 μm are dispersed in 100 parts by weight of xylene, 1.5 parts by weight of the above reaction product is added thereto, and the mixture is stirred, filtered and dried. Thus, surface-hydrophobic stainless steel flakes were obtained. The obtained stainless steel flakes have n
Dispersed in n-heptane in a heptane / water bilayer solution.
In addition, the obtained stainless flakes were added to epoxy resin 2
The scanning electron microscope observation of the fracture surface of the compound when 0% was added revealed that the fracture surface of the resin and the stainless flakes had an interfacial fracture mode and a cohesive fracture mode corresponding to "when adhesion was good" in the macroscopic peel test. It was in a state that they were mixed, indicating that the stainless flakes and the resin were firmly bonded. On the other hand, this surface-hydrophobic stainless steel flake was added to epoxy resin stepwise in the range of 5% to 30% to make a compound, and the thickness was 1 by injection molding.
As a result of making a film-like test piece of m / m and measuring the tensile strength, it was confirmed that the strength increased in proportion to the added amount.

Comparative Example 1. The same stainless flakes as in Example 1 above were used without using Bremmer CP30.
The surface treatment was performed only with Organix SI310. The obtained stainless flakes were dispersed on the n-heptane side in the n-heptane / water two-layer solvent. However, in ABS resin 10
%, And microscopic observation was carried out in the same manner as in Example 1. As a result, it was found that it had an interfacial fracture mode and surface treated stainless steel and ABS.
Insufficient resin bonding.

[0021]

EFFECTS OF THE INVENTION According to the method of the present invention, it is possible to achieve a very high degree of surface hydrophobization of a metal material. Therefore, the surface hydrophobic metal material produced by the method of the present invention has a strong kneadability with an organic resin, and has a wide range of properties as a functional imparting material such as strengthening the mechanical strength of the organic resin, imparting conductivity, and magnetic shielding. Available for

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoji Endo 5-13-2 Minamihachiman, Ichikawa-shi, Chiba Matsumoto Pharmaceutical Co., Ltd. (56) Reference JP-A-60-123561 (JP, A) )

Claims (1)

(57) [Claims] 1. A hydrophobic compound having a silyl isocyanate having a Si-NCO bond and at least one group selected from the group consisting of silanol group, hydroxyl group, mercapto group, amino group, epoxy group and carboxyl group in the molecule. A method for producing a surface-hydrophobic metallic material, which comprises reacting a reaction product with a compound on the surface of the metallic material.