JPH037336A - Article having p-xylene polymer film improved for adhesive and hardness - Google Patents

Abstract

PURPOSE:To improve wettability for adhesive and to reduce scratch by sequentially providing a p-xylene polymer film or chlorinated p-xylene polymer film and a synthetic resin film having 4H or more of hardness in this order on a material to be protected. CONSTITUTION:In order to prevent wettability with adhesive of high corrosionproof article and scratch to be formed with a p-xylene polymer film or chlorinated p-xylene polymer film on a material to be protected such as rare earth iron alloy magnet, etc., the surface of the xylene polymer film or the chlorinated polymer film is coated with a synthetic resin film having 4H or more of hardness and satisfactory wettability. The resin includes, for example, epoxy resin, acrylic resin, and melamine resin. A synthetic resin paint coating method includes, for example, a dipping method, a spraying method, etc., as an arbitrarily coating method, and the thickness of the coating after drying is 2-30mum and more desirably 5-15mum.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides p-
Regarding a corrosion-resistant article formed with a xylylene polymer film or a chlorinated p-xylylene polymer film, in particular, improving the wetting of a highly corrosion-resistant product with an adhesive having a p-xylylene polymer film or a chlorinated p-xylylene polymer film on the surface, The present invention also relates to highly corrosion-resistant articles that suppress the occurrence of scratches and the like.

(Prior art) Conventionally, Sm-C○-based magnets have been used as high-energy product magnets, but rare earth iron-based magnets have recently attracted attention because of their advantages in terms of cost, Isoki processability, and higher energy product. rare earth elements, especially rare earth elements with an atomic ratio of 8 to 30%, 2 to 2
A composition consisting of 8% B and balance Fe and unavoidable impurities has been found to be effective.

However, rare earth iron magnets are inferior to Sm--Co magnets in terms of corrosion resistance, and various surface protection treatments are being considered.

Rare earth iron magnets are manufactured using sintering and rapid cooling methods. This type of magnet contains a large amount of Nd and E, which are easily oxidized, and therefore has poor chemical resistance, especially against acids and alkanolytes.In surface treatments such as wet plating, the surface may be damaged during pre-treatment with acids, alkalis, etc. or during the plating process. Even if plating is possible, internal corrosion may occur due to the influence of chemicals that have entered the interior, and magnetic properties may deteriorate due to erosion between crystal grains.

Materials manufactured by the rapid cooling method have less distortion due to external forces and less deterioration of magnetic properties due to heat than materials manufactured by the sintering method. However, the rapidly cooled powder is made of plastic, etc.
It is often used in L, and requires a coating material that has high adhesion strength to both the magnet material and the pound material on the magnet surface.

Also, is it known to provide a plasma polymerized coating on this type of magnet, especially on this type of sintered magnet?
6811), it was difficult to obtain sufficient strength with conventional multi-element coatings.

For example, in the case of acrylic acid, active oxygen is present during plasma polymerization, and plasma etching occurs simultaneously with plasma polymerization. Therefore, the hardness and density of the protective polymer film are not sufficient, and the degree of polymerization is also low. Therefore, it cannot function satisfactorily as a corrosion-resistant protective film, such as not having sufficient gas barrier properties.

Additionally, a polymer resin film has been formed on the surface of rare earth sintered metal magnets as a protective coating (Japanese Patent Application Laid-open Nos. 1982-1982, 1982-1982, 1985-81908, and 60-63901). etc.), the polymer resin membrane is moisture permeable,
Since the oxygen permeability is high and the affinity with rare earth sintered metal magnets is low, sufficient adhesion cannot be ensured.

Furthermore, there are no films that have both adhesion and corrosion resistance, such as fluorocarbon resins that require high-temperature baking and which lead to oxidation of the magnet, and epoxy resins that have poor corrosion resistance. Furthermore, it has been proposed to form a film of xylylene resin by vacuum evaporation, but the degree of polymerization is low and there are problems with corrosion resistance (Japanese Patent Laid-Open No. 103714/1983).

Among these polymer resin films, p-xylylene polymer films and chlorinated p-xylylene polymer films are known as materials that have extremely good barrier properties against moisture and oxygen, and therefore have extremely excellent corrosion resistance. (The product made by the gas phase polymerization method is commercially available from Union Carbide Company in the United States under the trade name Parylene).

(Problems to be solved) However, when a highly corrosion-resistant magnet coated with a p-xylylene polymer film or a chlorinated p-xylylene polymer film is fixed to a part of electrical or electronic equipment using an epoxy resin or other adhesive, this polymerization occurs. Because the membrane has a high contact angle of 90 degrees and is water repellent, it has poor compatibility with adhesives, making it difficult to obtain sufficient adhesive strength, which has hindered its practical use. Therefore, for forced use, mechanical means such as locking bands, screws, and rivets are required, which poses problems in terms of workability and space. In addition, although P-xylylene polymer film and chlorinated p-xylylene polymer film coating have excellent corrosion resistance, they are easily scratched and are not suitable for areas that come into mechanical contact or friction with other objects. There is a problem that makes it unusable.

(Object of the Invention) Therefore, the object of the present invention is to provide an article coated with a p-xylylene polymer film or a chlorinated p-xylylene polymer film, particularly a rare earth iron-based magnet, which has good wettability with adhesives and less scratches caused by external forces. There is a particular thing.

(Means for Solving the Problems) After making various studies to solve the above-mentioned drawbacks, the present inventor found that the surface of the protected material of the rare earth iron magnet was
- By coating a xylylene polymer film or chlorinated p-xylylene polymer film and then encasing a thin layer of synthetic resin coating, especially resin coatings such as epoxy resin, acrylic resin, and melamine resin, the surface hardness is high and resistant to adhesives. It was found that the wettability was greatly improved. More preferably, the bonding strength between the p-xylene polymer film or the chlorinated p-xylylene polymer film and the synthetic resin coating film can be adjusted by subjecting the surface of the material to be protected to plasma treatment or coating it with a plasma polymer film. can be improved.

(Detailed Description of the Invention) Corrosion-Resistant Article In the present invention, the corrosion-resistant article refers to a material to be protected coated with a p-xylcine polymer film and a chlorinated p-xylylene polymer film. The material to be protected here can be any material, such as electronic parts whose characteristics deteriorate due to the influence of humidity or oxygen, such as alloy magnets, but the above-mentioned rare earth irons, which are particularly prone to rust due to the action of surrounding humidity and air. It is a system magnet. For example, N
The surface of a rare earth iron magnet such as a d-Fe magnet is first polished to a surface roughness Ra of about 1 μm or less.

Such rare earth iron-based magnets have poor corrosion resistance, and are generally RT-B or RT-B-M (where R is a rare earth element and T is Fe or a transition metal mainly composed of Fe or Co). , M is at least one of Zr, Nb, Mo, Hf, Ta, W), for example, Nd-Fe-B',
Examples include NdFe-B-Zr, Mitsushmetal, and any rare earth iron-based magnets. Such magnets can be used in the form of sintered magnets obtained by molding and sintering powder, or bonded magnets obtained by mechanically pulverizing these magnets and bonding them with an organic binder of 10% by weight or less.

Electronic components such as magnets having coatings of p-xylylene polymer films and chlorinated p-xylylene polymer films are known per se.

Such coatings include, for example, Parylene N (boryl xylylene), Valun C (polymonochlorochloro p-xylylene), and Parylene D (polydichloro p-xylylene) manufactured by Union Carbide Company of the United States, but they have low gas permeability. Therefore, parylene C is particularly preferred. Films such as polyp-xylylene are obtained by thermally decomposing dimer gas under reduced pressure. The film thickness is 0.5μm or more, preferably 1~
It is 20 μm. However, p-xylylene polymer films and chlorinated p-xylylene polymer films have poor adhesion and are easily peeled off from the surface of the material to be protected, and therefore do not have sufficient corrosion resistance. As a countermeasure to this problem, the present inventor has recently proposed improving the adhesiveness of the surface of the material to be protected, thereby improving the corrosion resistance. One method is to improve adhesiveness or adhesion by subjecting the surface of the material to be protected to plasma treatment to perform etching, formation of various radicals, functional groups such as OH, etc. (Japanese Patent Application No. 1-67521). Another method is to form a plasma polymerized film consisting essentially of carbon and hydrogen on the surface of the material to be protected to improve adhesion to p-xylylene polymeric films and chlorinated p-xylylene polymeric films, resulting in improved corrosion resistance. Improve (Japanese Patent Application No. 109063/1983). Still other methods employ methods such as increasing the surface smoothness of the material to be protected or combining this with the above method (Japanese Patent Application No. 1-6928).
No. 9). Corrosion-resistant articles to which the present invention is applied generally consist of a material to be protected coated with a p-xylylene polymer film and a chlorinated p-xylylene polymer film, and preferably are the improved articles described above. Furthermore, the synthetic resin coating film for improving hardness and adhesion, which is essential in the present invention, may be applied directly to the surface of the p-xylylene polymer film and the chlorinated p-xylylene polymer film, but preferably the synthetic resin coating film p prior to application of
- It is preferable to subject the surfaces of the xylylene polymer film and chlorinated p-xylylene polymer film to the above plasma treatment or plasma polymer film. Note that these processes will be described later.

The surface smoothing described above involves polishing the surface of the protected material, a rare earth iron magnet, to a surface roughness Ra of approximately 1 μm according to the JIS standard.
By doing the following, corrosion resistance will be dramatically improved. The reason for this is not clear, but the step coverage characteristics and surface roughness of the p-xylylene polymer film and chlorinated p-xylylene polymer film are well matched, allowing the protective film to cover the material to be protected. It is thought that reducing the surface roughness reduces defects such as holes, holes, etc. that initially exist. Normally, the surface roughness of rare earth iron-based magnets is quite large, and is 2 μm12J or more expressed in Ra according to the JIS standard. Prior to plasma treatment and formation of a hydrocarbon-based plasma polymerized film, a p-xylylene polymerized film, or both, the surface of the material to be protected, especially the rare earth iron magnet, is polished to a surface roughness Ra of approximately 1 μm or less. It is preferable to polish the surface to a certain level and then form the above-mentioned protective film on the surface.

As briefly mentioned above, the surface of the rare earth iron magnet and/or the surface of the p-xylylene polymer film and the chlorinated p-xylylene polymer film may be subjected to plasma treatment. Plasma treatment is performed using a rare gas such as Ar, He, Ne, etc.82N2. O□,
Gases such as co, co2H20, NOx, Ne2, and NH3 are introduced into a vacuum chamber, turned into plasma, and then brought into contact with a rare earth iron magnet. The following conditions are usually used for plasma treatment. gas pressure 0
．． Direct current or alternating current can be used as a power source at 01 to 10 Torr, and the frequency of alternating current can be from 50 Hz to 5 GHz. Processing conditions vary depending on the shape and amount of the sample, but the power consumption can be set to 10 W to 10 KW and the processing time can be set to 0.5 seconds to 10 minutes. The contact angle of the surface after treatment is preferably 30° or less.

Plasma treatment activates the surface of the magnet and/or p-xylylene polymer film and chlorinated p-xylylene polymer film, and depending on the type of gas used, various active radicals and functional groups such as ○H groups are generated and subsequently formed. The reactivity and wettability of the plasma-polymerized film or synthetic resin film are improved, and as a result of the adhesive sufficiently penetrating into the substrate (anchor effect), the adhesion is greatly improved, and the surface hardness is also greatly improved.

Plasma-polymerized AIr'' As briefly mentioned above, a plasma-polymerized film may be formed on the surface of the rare earth iron magnet and/or the p-xylylene polymeric film and the chlorinated p-xylylene polymeric film.Plasma The polymerized membrane can use any conventionally known monomer gas, such as methane, ethane, propane, butane,
In addition to hydrocarbon monomers such as hentane, ethylene, propylene, butene, butadiene, acetylene, and methylacetylene, silicon-based monomers such as tetramethoxysilane, hydrogen fluoride-based monomers such as tetrafluoroethylene, methyl methacrylate, etc. can be mentioned. In particular, a plasma polymerized film consisting essentially of carbon and hydrogen forms a hard film on the surface with no pinholes, has good corrosion resistance, and has excellent long-term stability. It is preferable because it has the advantage that the characteristics can be maintained, and in particular, H/C=1.5 or less in terms of the ratio of the number of atoms (atomic composition ratio) is preferable because it is a plasma with good three-dimensionally crosslinked characteristics. A polymer film can be formed. In this case, sufficient corrosion resistance can be obtained with a film thickness of 0.2 μm or less. Such a plasma polymerized protective film can be produced by reducing the amount of hydrocarbon monomer gas, lowering the reaction pressure, and increasing the applied power. That is, by lowering the reaction pressure and increasing the applied power, the decomposition energy per unit amount of monomer increases, the decomposition progresses, and a crosslinked plasma polymerized protective film can be formed. The energy density W/(FM) suitable for carrying out the present invention is 108 J/kg or more (W is the plasma input power of 57 seconds, F is the raw material gas flow rate kg/sec, and M is the raw material gas molecular weight). Other gases such as hydrogen and inert gas can be used as carrier gases.

However, more than a trace amount of oxygen, which comes as an unavoidable impurity, must not be used. In this way, when the material consists essentially only of carbon and hydrogen, excluding unavoidable impurity gases, it exhibits high corrosion resistance and good adhesion. Furthermore, when forming a plasma polymerized film, the effect can be further improved by raising the temperature of the magnet.

In the present invention, a highly corrosion resistant product formed by forming a p-xylylene polymer film or a chlorinated p-xylylene polymer film on the surface of a material to be protected, such as a rare earth iron alloy magnet, can be protected against wetting and scratches by adhesives. In order to prevent this from occurring, the surface of the p-xylylene polymer film or chlorinated p-xylylene polymer film is coated with a synthetic resin film having a hardness of 4H or higher and good wettability.

Such synthetic resin materials include epoxy resin, acrylic resin, and melamine resin.

These resins satisfy the wettability and hardness conditions described above. Any coating method such as a dip method or a spray method can be used to apply the synthetic resin paint. The coating thickness is 2~2~ after drying.
It is 30μ, more preferably 5 to 15μ. If it is too thin, its hardness is low and it is easily scratched. If it is too thick, dimensional unevenness will occur and accuracy will be difficult to achieve.

(Explanation of Examples) Raw materials for food bonded magnets are weighed, melted, cast, and the alloy composition is Nda.
Fe79. a Zr4B7.5 (alloy 1) and Nd
Two types of alloy ingots were manufactured: a. 5F1980Zr3.5Ba (alloy 2). These were each melted by high frequency, injected onto the surface of a Cu single roll (peripheral speed 20 m/sec) in an Ar atmosphere, and rapidly quenched to obtain an alloy ribbon. This was heat-treated at 700° C. for 30 minutes in an Ar atmosphere, and then ground in a stamp mill to an average diameter of 50 to 200 LLm to obtain magnet powder.

2.5 wt% of epoxy resin was mixed with the above magnet powder, pressure molded at 5 ton/cm2, and the resin was cured by blowing at a temperature of 180°C. The magnetic properties of the obtained compact are shown in Table 1.

Table 1 The surface roughness Ra of each of these molded bodies was 21 μm. The surfaces of these molded bodies were polished to 0.3 μm.

Next, the surfaces of these samples were subjected to plasma treatment under the following conditions.

Using 0.02 gas, the gas pressure was 0. I Torr 1356M
The surface was subjected to plasma treatment using a Hz RF power source at too much power. The contact angle of the surface was 10°.

Next, all of these molded bodies were charged into a plasma polymerization apparatus, and the pressure was 0.02 Torr and the RF power was 800.
A hydrocarbon polymer film was formed on the surface of the molded body under the conditions of W, CH453CCM. The film forming process was continued until the film thickness reached approximately 0.15 μm as measured using an ellipsometer. When measured with a secondary electron mass spectrometer SIMS, H/
The C ratio was 1.21.

Next, a 10 μm thick film of parylene C was formed on the obtained molded body by thermal decomposition and polymerization of a monochloropara-xylene dimer at 25° C. and 0.05 Torr.

(Resistance ↑low internal magnetism Nd + g Fe, alloy with composition consisting of 7B8 (alloy 3)
was prepared, coarsely pulverized, and then finely pulverized using a jet mill into magnetic powder with an average particle size of 3.5 μm. 1 of this magnetic powder
Molding was carried out at a pressure of L5ton/am2 in a magnetic field of 0kOe. Thereafter, sintering was performed in vacuum at 1100°C for 2 hours, followed by aging treatment at 600°C for 11 hours.

The magnetic properties of the obtained magnet are shown in Table 2. The surface roughness was 23 μm.

Table 2 This compact was subjected to the same treatment as in the preparation of the above-mentioned corrosion-resistant bonded magnet to obtain a sintered magnet having a surface coating film with an H/C ratio of 1.21. Next, Parylene C was coated to a thickness of 10 μm. All alloys 1.2.3 subjected to these treatments have good corrosion resistance.

, Example 1 Bonded Magnetism) H as a plasma gas was applied to the above corrosion-resistant alloy 1.2.
2, plasma treatment was performed using a gas pressure of 0.2 Torr and a power source of 100 kHz and a power of 200'W. Spray epoxy resin onto the surface of Alloy 1 to a dry thickness of 0.
It was coated to a thickness of ~40 μm. Table 3 shows the surface hardness (pencil hardness) and dimensional accuracy of Alloy 1. Dimensions were measured at 20 locations, and the average value and variation are shown.

Furthermore, among the above samples, the epoxy resin had a dry thickness of 10 μm.
(Sample 1.2 for Alloy 1.2, and Comparative Sample 1.2 for No epoxy resin)
As an adhesion test, the bottom is 1 cm x 1 cm and the length is 1.
It was adhered to the surface of a 0 cm square iron prism using epoxy adhesive. A peel test was conducted using Tensilon. Table 4 shows the results.
Shown below. C in the table indicates the interface between parylene and adhesive,
E indicates the interface between iron and adhesive. The results are shown in Table 4.

''A Treatment Example 2 - Stone) Alloy 3 was subjected to the above corrosion resistance treatment. This sample was subjected to plasma treatment under the same conditions as in Example 1. Acrylic resin was applied to the surface to a dry thickness of 0 to The surface hardness and dimensional accuracy are shown in Table 3. The results of the adhesion test are also shown for samples coated with acrylic resin to a dry thickness of 10 μm (sample 3, and comparative sample 3 without resin film). 4.

- Example 3 (Real magnet) The above corrosion-resistant alloy 1.2 was charged into a plasma polymerization apparatus, the pressure was 0.02 Torr, the RF power was 800 W,
A hydrocarbon polymer film was formed on the surface of the molded body under the conditions of CH, 5SCC''Y1. The film formation process was carried out until the film thickness reached approximately 0.15 μm as measured using an ellipsometer. The obtained film When measured using a secondary electron quality analyzer SIMS, the H/C ratio was 121.Melamine resin was applied to the obtained alloy 1 to a dry thickness of 0 to 40 μm.The results of the hardness test are shown in Table 3. The dry thickness of melamine resin is 10 gm.
(alloy 1.2 and sample 1' respectively)
, 2'), these samples were adhered to the surface of the iron rod by epoxy adhesive. The results of the adhesion test are shown in Table 4.

Example 4: A plasma polymerized film was formed on the above-mentioned corrosion-resistant Alloy 3 under the same conditions as in Example 3. Dry epoxy resin to thickness 10
Epoxy adhesive was applied to the sample B (sample 3''). The results of the adhesion test are shown in Table 4.

Example (alloy) Table 3 Example 3 (alloy 2) Table 4 Example 2 (alloy 3) (Summary of effects) As can be seen from the second example, p-
Highly corrosion resistant products with a xylylene polymer film or chlorinated p-xylylene polymer film on which the outer surface is then subjected to plasma treatment or a plasma polymer film formed thereon do not get wet with adhesives and have improved adhesive strength. It can be seen that the hardness is also improved. Therefore, this article can be easily fixed in place using adhesives in the various applications mentioned above, and can also be used in areas subject to the effects of thick friction.

Claims (1)

[Scope of Claims] 1) A highly food-resistant product having, in this order, a p-xylylene polymer film or a chlorinated p-xylylene polymer film, and a synthetic resin coating film with a hardness of 4H or more on the surface of a material to be protected. 2) The synthetic resin coating is selected from the group consisting of epoxy resin, acrylic resin, and melamine resin.
Highly food resistant products listed in section. 3) The highly corrosion-resistant article according to item 1 above, wherein the synthetic resin coating has a thickness of 2 to 30 μm. 4) The highly food-resistant product according to item 1 or 3, wherein the p-xylylene polymer film or the chlorinated p-xylylene polymer film has a thickness of 0.5 μm or more. 5) The highly corrosion-resistant product according to any one of items 1 to 4, wherein the material to be protected is a rare earth iron alloy magnet. 6) A p-xylylene polymer film or a chlorinated p-xylylene polymer film is formed on the surface of the material to be protected by vapor phase thermal polymerization, and a resin selected from the group consisting of epoxy resin, acrylic resin, and melamine resin is applied to the surface. A method for producing a highly corrosion-resistant product, which comprises applying a coating and drying or curing the coating.