WO2023022236A1

WO2023022236A1 - Composite material, sputtering target, thin-film coating member, and manufacturing method therefor

Info

Publication number: WO2023022236A1
Application number: PCT/JP2022/031445
Authority: WO
Inventors: 康訓多賀
Original assignee: 株式会社表面・界面工房
Priority date: 2021-08-20
Filing date: 2022-08-19
Publication date: 2023-02-23

Abstract

Provided is a composite material containing: a matrix of metal oxides; a fluororesin; and one or more types of metallic materials selected from the group consisting of In, Sn, and Bi.

Description

Composite material, sputtering target, thin film coated member, and manufacturing method

Cross-reference to related applications

This international application is the Japanese Patent Application No. 2021-134966 filed with the Japan Patent Office on August 20, 2021, and the Japanese patent application filed with the Japan Patent Office on December 7, 2021 It claims priority based on Application No. 2021-198807, and the entire contents of Japanese Patent Application No. 2021-134966 and Japanese Patent Application No. 2021-198807 are incorporated by reference into this international application. .

The present disclosure relates to composite materials containing inorganic materials and organic materials.

Research and development of composite materials of inorganic and organic materials is actively carried out with the aim of combining and complementing the strengths and weaknesses of inorganic and organic materials and developing new functions. For example, metal compounds, which are inorganic materials, have high rigidity and are excellent in heat resistance and environmental resistance. On the other hand, inorganic materials are generally inferior in flexibility, and require high-temperature processes for manufacturing and processing, lacking in energy efficiency. Examples of organic materials include hydrocarbon compounds (methane-based, ethylene-based, acetylene-based, halogen-based, olefin-based, etc.) and fluorine-based compounds. These are widely used as synthetic resin materials such as melamine resins, urea resins, alkyd resins, polyester resins, vinyl chloride resins, styrene resins, acrylic resins, polyethylene resins, and fluororesin silicon resins. In general, the advantage of organic materials is that they are flexible and flexible, but the disadvantages of organic materials are that they lack scratch resistance, heat resistance, and weather resistance (ultraviolet light resistance).

In addition, one of the problems with composite materials (hereinafter also simply referred to as "composite materials") composed of inorganic and organic materials is a low-temperature synthesis process that is rate-determined by the heat resistance of the organic materials. In fact, the heat resistance of polytetrafluoroethylene (PTFE), which is an organic material having the highest heat resistance, is about 300°C. In the production of composite materials by such a low-temperature process, an organic binder such as acrylic is usually used for the purpose of bonding and joining to maintain the shape during pressure molding. However, composite materials sintered at a low temperature of about 300° C. are likely to crack or break due to insufficient mechanical strength, and there is concern about the effects of organic binder remaining in the composite material.

　There is a strong need not only for bulk materials but also for thin films to combine inorganic and organic materials. In fact, research and development have been conducted on surface treatments in which inorganic or organic thin films are formed on inorganic or organic substrates to impart new functions. In addition, from the viewpoint of weight reduction and deformability, light and shape-flexible resin films have begun to be used in place of conventional heavy and hard inorganic substrates. Sputtering, which enables low-temperature film formation, is widely used for the surface treatment of such resin substrates and substrates. In addition, as the processing area increases, the size of the sputtering target made of an organic-inorganic composite material is increased, so that the composite material is required to have higher mechanical strength.

Furthermore, in the research and development of thin films, in addition to conventional inorganic compounds, the preparation and evaluation of composite compound films with organic substances are being studied in pursuit of higher functionality. However, since the sintering temperature of the inorganic-organic mixture target is rate-determined by the vaporization temperature of the organic matter and is produced by low-temperature sintering, its mechanical strength is limited by the high-temperature sintering disclosed in Patent Document 1 and Patent Document 2, for example. It was lower than that of the bonded target, and sufficient mechanical strength was not obtained.

JP 2012-162755 A JP 2019-137875 A

The object of the present disclosure was made in view of the above problems, that is, to propose a composite material with high mechanical strength and a method for producing the same.

One aspect of the present disclosure is a composite material that includes a matrix, a fluororesin, and a metal material. The matrix is a metal oxide. The metal material is one or more selected from the group including In, Sn, and Bi. Such composite materials have high mechanical strength.

In the composite material described above, the metal oxide may contain one or more selected from the group containing Ce, Y, Al, Si, and Nb as metal elements. In the composite material described above, the fluororesin includes polytetrafluoroethylene, tetrafluoroethylene/hexafluoropropylene copolymer, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/ethylene copolymer and polyfluoride. It may contain at least one or more selected from the group containing vinylidene.

Further, in the composite material described above, the mixed weight ratio of the metal oxide and the fluororesin may be in the range of 20:1 to 1:1. Further, the metal material may be 0.1% by weight or more and 50% by weight or less when the total weight of the metal oxide, the fluororesin, and the metal material is 100%. With such a mixture weight ratio, the composite material can have higher mechanical strength.

In addition, the composite material described above may form a composite compound phase of metal fluoride or fluorocarbon between the metal oxide and the fluororesin and between the metal material and the fluororesin. Such a composite material can have higher mechanical strength.

One aspect of the present disclosure is a sputtering target, which is composed of the composite material described above. Such a sputtering target has high mechanical strength and is less likely to be damaged even if it is enlarged, for example.

One aspect of the present disclosure is a thin film coated member comprising a workpiece and a thin film. A thin film is formed on the surface of the workpiece by sputtering. Also, the thin film includes a matrix, a fluororesin, and a metal material. The matrix is a metal oxide. The metal material is one or more selected from the group including In, Sn, and Bi. With such a thin film coated member, the mechanical strength of the thin film is high, so damage to the thin film is suppressed.

One aspect of the present disclosure is a method for producing a composite material, comprising: mixing material powders containing metal oxide powder, fluororesin powder, and metal material powder to obtain a mixture; and obtaining a sintered body by firing the molded product at 100° C. or higher and 350° C. or lower. The metal material powder contains one or more metal materials selected from the group including In, Sn, and Bi. With such a production method, a composite material having high mechanical strength can be produced while maintaining the functions of the fluororesin.

One aspect of the present disclosure is a method for manufacturing a thin-film coated member, comprising: obtaining a mixture by mixing material powders containing metal oxide powder, fluororesin powder, and metal material powder; obtain a molded product by molding; obtain a sintered body by firing the molded product at 100° C. or higher and 350° C. or lower; and use the sintered body as a sputtering target to form a thin film on a predetermined work by sputtering. and forming. The metal material powder contains one or more metal materials selected from the group including In, Sn, and Bi. With such a manufacturing method, it is possible to manufacture a thin-film coated member in which the thin film has high mechanical strength while maintaining the function of the fluororesin in the thin film.

It is a figure which shows the apparatus which performs a bending-strength evaluation test. 4 is a graph showing spectral properties of a CeO ₂ -PTFE-In film fabricated using a composite sputtering target. 1 is a graph showing the nanoindenter hardness of CeO ₂ -PTFE-In films fabricated using composite sputtering targets. 1 is a graph showing the water contact angle of a CeO ₂ -PTFE-In film fabricated using a composite sputtering target.

11... sample fixing jig, 12... load applying jig, 13... sample

The embodiments of the present disclosure will be described below together with the drawings.

[1. Composition of Composite Material]
Composite materials of the present disclosure include metal oxides, fluororesins, and metal materials. Composites of the present disclosure may include other materials, for example, as long as they do not detract from the superior properties of the products described in the present disclosure.

[1-1. metal oxide]
Metal oxides are the matrix of the composite material and are contained in a relatively large proportion of the composite material. There are no particular restrictions on the specific types and blending ratios of the elements in the metal oxide. It is preferable that one or more selected from the group including Ce, Y, Al, Si and Nb be included as metal elements.

(i) Cerium Oxide As the cerium oxide used in the composite material according to the present embodiment, cerium trioxide (Ce ₂ O ₃ ) and cerium dioxide (CeO ₂ ) are preferable, and cerium dioxide is more preferable. As the cerium oxide used in the composite material, one or a mixture of two or more of these cerium oxides may be used.

(ii) Aluminum Oxide Aluminum oxide (Al ₂ O ₃ ) is exemplified as an aluminum oxide that can be used in the composite material according to this embodiment.

(iii) Silicon Oxide Silicon oxide (SiO ₂ ) is exemplified as a silicon oxide that can be used in the composite material according to the present embodiment.

(iv) Yttrium Oxide Yttrium oxide (Y ₂ O ₃ ) is exemplified as yttrium oxide that can be used in the composite material according to the present embodiment.

(v) Niobium Oxide Niobium oxide (Nb ₂ O ₅ ) is exemplified as a niobium oxide that can be used in the composite material according to the present embodiment.

<Regarding particle size>
The average particle size of the metal oxide particles (powder) used to produce the composite material of the present embodiment is not particularly limited as long as the composite material can be produced. The particle size of the metal oxide should be 0.5 μm to 50 μm, preferably 2 μm to 20 μm, more preferably 3 μm to 10 μm.

[1-2. Fluororesin]
A fluororesin is a compound having a fluorine-carbon bond, typically a compound having a structure in which one or more hydrogen atoms of an organic compound such as a hydrocarbon are substituted with fluorine atoms.

The fluororesin used in the method for producing a composite material of the present embodiment includes, for example, a structural unit derived from a monomer having a structure in which one or more hydrogen atoms of an α-olefin are substituted with fluorine atoms. Preferably, those containing as one of the main structural units can be exemplified. The term "main structural unit" as used herein refers to one having the above structure in an amount of 20 mol% or more based on the total of 100 mol% of the structural units derived from all constituent monomers. The above structure may preferably contain 40 mol % or more, more preferably 60 mol % or more, still more preferably 80 mol % or more, and most preferably 90 mol % or more.

Examples of monomers having a structure in which one or more hydrogen atoms of the α-olefin are substituted with fluorine atoms include tetrafluoroethylene, trifluoroethylene, vinylidene fluoride, vinyl fluoride, hexafluoropropylene, Examples include pentafluoropropylene, tetrafluoropropylene, trifluoropropylene, and chlorotrifluoroethylene. As the monomer having a structure in which one or more hydrogen atoms of the α-olefin are substituted with fluorine atoms, one or a mixture of two or more thereof may be used.

Examples of fluororesins containing the above monomers as structural units include polytetrafluoroethylene (PTFE), polyhexafluoropropylene (PHFP), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVA), tetrafluoroethylene-hexa Fluoropropylene copolymer (FEP), tetrafluoroethylene/ethylene copolymer (ETFE), tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (PFA), chlorotrifluoroethylene/ethylene copolymer (ECTFE), and Polychlorotrifluoroethylene (PCTFE) and the like can be mentioned. One or a mixture of two or more of these may be used as the fluororesin.

Among these, polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-ethylene copolymer It is preferable to use at least one selected from the group including (ETFE) and polyvinylidene fluoride (PVDF).

<Oxygen plasma treatment>
It is preferable to plasma-treat the surface of the fluororesin particles (powder) used in manufacturing the composite material of the present embodiment. Specifically, by treating the surface of fluororesin particles (powder) with oxygen plasma, in addition to C—F ₂ bonds, C—C, and C—H, C—F, C—F ₃ , and CO ₂ , C═O, and C—H bonds newly appear on the surface of the fluororesin particles. These new surface bonding groups are highly reactive and effective for sintering with metal oxides.

<Regarding particle size>
The average particle size of the fluororesin particles (powder) used in producing the composite material of the present embodiment is not particularly limited as long as the composite material can be produced. The average particle size of the fluororesin is preferably 0.1 μm to 20 μm, preferably 0.2 μm to 10 μm, more preferably 0.3 μm to 5 μm.

[1-3. Metal material]
The metal component is a metal material having a melting point of 400° C. or less. As the metal material used in the method for producing the composite material of the present embodiment, one or more selected from the group including In, Sn, and Bi are preferable.

<Regarding particle size>
The average particle size of the metal material particles (metal material powder) used in producing the composite material of the present embodiment is not particularly limited, but is 0.1 μm to 50 μm, preferably 0.2 μm to 10 μm. Good to have.

[1-4. Composition of each component]
The mixing weight ratio (mixing ratio) of the metal oxide, the fluororesin, and the metal material will be described. The mixing ratio of the metal oxide particles (powder) and the fluororesin particles (powder) used when producing the composite material is such that the mixed weight ratio of the metal oxide and the fluororesin is in the range of 20:1 to 1:1. good too. In addition, it is preferable that the ratio of the fluororesin is larger than 10:1. Also, it is preferable that the ratio of the fluororesin is smaller than 5:1. The content of the metal material may be 0.1% by weight or more and 50% by weight or less when the total weight of the metal oxide, the fluororesin, and the metal material is taken as 100%. The metal material is preferably 0.5% by weight or more, more preferably 5% by weight or more. Moreover, it is preferable that the metal material is 25% by weight or less.

[1-5. Physical properties and chemical bonding state of composite materials]
<Density>
Although the density of the composite material of the present embodiment is not particularly limited, it is 3.0 g/cm ³ or more and 8.0 g/cm 3 or less, preferably 3.2 g/cm ³ or more and 8.0 g/cm ³ or more when calculated based on the measured weight/volume. 0 g/cm ³ or less, more preferably 3.5 g/cm ³ or more and 5.3 g/cm ³ or less.

<Breaking strength>
The breaking strength of the composite material of the present embodiment is measured according to the bending strength test method for fine ceramics specified in JIS R 1601, and when this is taken as the breaking strength, it is 0.2 MPa, preferably 0.5 MPa or more, More preferably, it is 1 MPa or more.

For the measurement, a bending strength evaluation test device (JT Toshi lSC-2/100) and an evaluation jig were used. As shown in FIG. 1 , a sample 13 was fixed by a sample fixing jig 11 and a load was applied by a load applying jig 12 .

<About chemical bonding state>
In the composite material of the present embodiment, the metal oxide matrix contains the metal oxide component, the fluororesin component, and the compound derived from the metal. At this time, between the metal oxide component, the fluororesin, and the metal component, that is, between the metal oxide and the fluororesin, and between the metal material and the fluororesin, the metal fluoride or fluorocarbon Forming a complex compound phase is preferable.

In the composite material and the composite material of this embodiment, what kind of compound each element forms can be confirmed by X-ray photoelectron spectroscopy (hereinafter sometimes abbreviated as "XPS analysis"). For XPS analysis, for example, an ESCA5400 type XPS analyzer manufactured by ULVAC-Phi is used, and Mg kα rays (for example, Mg kα rays with a beam diameter of 1.1 mm generated under the conditions of a power of 400 W and a voltage of 15 kV) are used as X-rays. can be measured using

[2. Composite material manufacturing method]
Examples of the method of manufacturing the composite material include a first manufacturing method including a mixing step, a molding step, and a sintering step, and a second manufacturing method including a mixing step and a hot molding step.

<First manufacturing method>
In the mixing step, material powders containing fluororesin powder, metal oxide powder, and metal material powder are mixed to obtain a mixture. The material powder may contain other materials. In this mixing step, the mixing ratio of the metal oxide particles (powder) and the fluororesin particles (powder) may be in the range of 20:1 to 1:1. Moreover, when the total weight of the metal oxide, the fluororesin, and the metal material is taken as 100%, it is preferable that the metal material is 0.1% or more and 50% or less by weight. The metal component used in the method for producing a composite material of the present embodiment is one or more selected from the group containing In, Sn, and Bi, and from metal oxide components (Ce, Y, Al, Si, Nb) It is preferred to contain a compound phase consisting of

In the subsequent molding step, the mixture obtained in the mixing step is compression-molded to obtain a molded product. Here, as an example, the molded product is molded by normal temperature pressurization (Cold Press, CP). The applied pressure can be, for example, 1 to 1.5 t/cm ² , but may be other than this. For the purpose of maintaining the shape during pressure molding, the mixture may be mixed with a resin binder (acrylic, etc.) by several percent.

In the subsequent sintering step, the molded product obtained in the molding step is fired at 100°C or higher and 350°C or lower, preferably 200°C or higher, and preferably 300°C or lower to obtain a sintered body. The resulting sintered body is the composite material.

<Second manufacturing method>
In the first production method, compression molding of the mixture to obtain a molded product and firing of the molded product at a temperature of 100° C. to 350° C. to obtain a sintered body were performed in different steps. The second manufacturing method differs from the first manufacturing method in that these are performed in one step. A second manufacturing method includes a mixing step and a thermoforming step.

The mixing step is the same as the mixing step in the first manufacturing method. For the purpose of maintaining the shape during pressure molding, the mixture may be mixed with a resin binder (acrylic, etc.) by several percent. In the hot molding step, after the mixing step, the mixture obtained in the mixing step is subjected to temperature-rising compression molding (hot press method, HP) at 100° C. to 350° C. to obtain a molded sintered body. The resulting sintered body is the composite material.

[3. Example]
In Examples 1-48, composite materials were made. In Example 49, the composite material of Example 5 was used as a sputtering target to form a film on a substrate to produce a thin-film coated member.

<Examples 1-12 and Comparative Example 1>
Molded workpieces were formed from the following materials.
Metal oxide: _CeO2 powder (manufactured by Nikki Co., Ltd., average particle size 5 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: In powder (manufactured by Mitsuwa Chemicals Co., Ltd., average particle size 40 μm)
A cerium oxide powder was prepared by a coprecipitation method. Cerium oxide powder (average particle size 5 μm) and PTFE powder (average particle size 3 μm) were mixed at a weight ratio of 10: 1 (Examples 3, 6, 9, 12), 7: 1 (Examples 2, 5, 8, 11). ), 5:1 (Examples 1, 4, 7, and 10), and further, when the total weight of In as the metal material, the metal oxide, the fluororesin, and the metal material is 100%, the metal material was mixed in the range of 0.1% to 50% by weight.

The mixture was then pressed at a molding pressure of 1 ton/cm ² and molded to a diameter of 3 inches and a thickness of 5 mm.

The molded product thus formed was sintered under normal pressure and heating conditions of 200°C for 3 hours to obtain a composite material as a sintered body. Also, the mechanical bending strength of the obtained composite material was measured. Table 1 shows the blending ratio (mixed weight ratio) and bending strength measurement results of Examples 1-12. In Table 1, the value next to the mixed weight ratio of metal materials is the weight percent of the metal materials when the total weight is taken as 100%.

In addition, cerium oxide powder (average particle size 5 μm) as a metal oxide and PTFE powder (average particle size 3 μm) as a fluororesin were mixed at a weight ratio of 7:1, and further, a metal oxide, a fluororesin, and a resin binder were mixed. When the total weight is 100%, a mixture containing 5% by weight of an acrylic resin as a resin binder is pressure-molded at room temperature and then sintered at 100°C. added to

<Examples 13-15>
A composite material was produced under the same conditions as in Example 4-6, except that the metal material was changed from In to Sn.
Metal oxide: _CeO2 powder (manufactured by Nikki Co., Ltd., average particle size 5 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: Sn powder (SN-AT-350 D50: 27 μm, manufactured by Fukuda Metal Foil & Powder Co., Ltd.)
Table 2 shows the mixing ratio (mixed weight ratio) and bending strength measurement results of Examples 13 and 15.

<Examples 16-18>
A composite material was produced under the same conditions as in Example 4-6, except that the metal material was changed from In to In-5% Sn powder.
Metal oxide: _CeO2 powder (manufactured by Nikki Co., Ltd., average particle size 5 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: In-5% Sn powder (Mitsubishi Materials Electronic Chemicals, particle size 0.03 μm)
Table 3 shows the mixing ratio (mixed weight ratio) and bending strength measurement results of Examples 16 and 18.

<Examples 19-21>
A composite material was produced under the same conditions as in Example 4-6, except that the metal material was changed from In to Bi.
Metal oxide: _CeO2 powder (manufactured by Nikki Co., Ltd., average particle size 5 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: Bi powder (manufactured by Nilaco Co., Ltd., particle size 74 μm)
Table 4 shows the mixing ratio (mixed weight ratio) and bending strength measurement results of Examples 19 to 21.

<Examples 22-24>
A composite material was produced under the same conditions as in Examples 4-6, except that the metal oxide was changed from CeO ₂ to SiO ₂ .
Metal oxide: _SiO2 powder (Shin-Etsu Chemical Co., Ltd., particle size 0.2 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: In powder (manufactured by Mitsuwa Chemicals Co., Ltd., average particle size 40 μm)
Table 5 shows the mixing ratio (mixed weight ratio) and bending strength measurement results of Examples 22-24.

<Examples 25-27>
A composite material was produced under the same conditions as in Examples 4-6, except that the metal oxide was changed from CeO ₂ to Al ₂ O ₃ .
Metal oxide: Al ₂ O ₃ powder (manufactured by EM Japan, particle size 1 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: In powder (manufactured by Mitsuwa Chemicals Co., Ltd., average particle size 40 μm)
Table 6 shows the mixing ratio (mixed weight ratio) and bending strength measurement results of Examples 25 and 27.

<Examples 28-30>
A composite material was produced under the same conditions as in Example 4-6, except that the metal oxide was changed from CeO ₂ to Y ₂ O ₃ .
Metal oxide: Y ₂ O ₃ powder (made by Iwatani Corporation, particle size 1 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: In powder (manufactured by Mitsuwa Chemicals Co., Ltd., average particle size 40 μm)
Table 7 shows the blending ratio (mixed weight ratio) and bending strength measurement results of Examples 28-30.

<Examples 31-33>
A composite material was produced under the same conditions as in Example 4-6, except that the metal oxide was changed from CeO ₂ to Nb ₂ O ₅ .
Metal oxide: Nb ₂ O ₅ powder (3N D50 manufactured by Taniobis Japan: 0.3 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: In powder (manufactured by Mitsuwa Chemicals Co., Ltd., average particle size 40 μm)
Table 8 shows the mixing ratio (mixed weight ratio) and bending strength measurement results of Examples 31 and 33.

<Examples 34-36>
A composite material was produced under the same conditions as in Example 4-6, except that the metal oxide was changed from CeO ₂ to Nb ₂ O ₅ and the metal material was changed from In to Sn.
Metal oxide: Nb ₂ O ₅ powder (3N D50 manufactured by Taniobis Japan: 0.3 μm)
Fluorine resin: PTFE powder (manufactured by Seishin Enterprise Co., Ltd., average particle size 3 μm)
Metal material: Sn powder (SN-AT-350 D50: 27 μm, manufactured by Fukuda Metal Foil & Powder Co., Ltd.)
Table 9 shows the blending ratio (mixed weight ratio) and bending strength measurement results of Examples 34 and 36.

<Examples 37-39>
In Examples 37-39, CeO ₂ , PTFE, and In were used as raw materials in the same manner as in Examples 1-12, but the grain size of CeO ₂ was changed. The mixed weight ratio is CeO ₂ :PTFE:In=70:10:8.8. The CeO ₂ powder had an average particle size of 0.8 μm, 5 μm, or 45 μm.

The molded product thus formed was sintered under normal pressure and heating conditions of 200°C for 3 hours to obtain a composite material as a sintered body. Also, the mechanical bending strength of the obtained composite material was measured. Table 10 shows the measurement results of the average particle size and bending strength of each component in Examples 37-39.

<Examples 40-42>
In Examples 40-42, CeO ₂ , PTFE, and In were used as raw materials in the same manner as in Examples 1-12, but the particle size of PTFE was changed. The mixed weight ratio is CeO ₂ :PTFE:In=70:10:8.8. The PTFE powder had an average particle size of 3 μm, 10 μm, or 30 μm.

The molded product thus formed was sintered under normal pressure and heating conditions of 200°C for 3 hours to obtain a composite material as a sintered body. Also, the mechanical bending strength of the obtained composite material was measured. Table 11 shows the measurement results of the average particle size and bending strength of each component in Examples 40-42.

<Examples 43-45>
In Example 43, the same materials and mixture ratio as in Example 37 were used to form a molded product at room temperature, followed by sintering at 100° C. for 1 hour to obtain a composite material as a sintered body.

In Example 44, a molded product was formed at room temperature using the same materials and mixture ratio as in Example 38, and then sintered at 200°C for 1 hour to obtain a composite material as a sintered body.

In Example 45, a molded product was formed at room temperature using the same materials and mixture ratio as in Example 39, and then sintered at 300°C for 1 hour to obtain a composite material as a sintered body.

Table 12 shows the compounding ratio (mixed weight ratio), test conditions, and bending strength measurement results of Examples 43-45.

<Examples 46-48>
Examples 46-48 were manufactured by the second manufacturing method. That is, a composite material was produced by subjecting the mixture to temperature-rising compression molding.

In Example 46, although the same materials and mixture ratio as in Example 37 were used, temperature-rising compression molding was performed at a pressure of 1.5 t/cm ² at 100° C. for 2 hours to obtain a composite material that is a sintered body. .

In Example 47, although the same materials and mixture ratio as in Example 38 were used, temperature-rising compression molding was performed at a pressure of 1.5 t/cm ² at 200° C. for 2 hours to obtain a composite material that is a sintered body. .

In Example 48, although the same materials and mixture ratio as in Example 39 were used, temperature-rising compression molding was performed at a pressure of 1.5 t/cm ² at 300° C. for 2 hours to obtain a composite material that is a sintered body. .

Table 13 shows the compounding ratio (mixed weight ratio), test conditions, and bending strength measurement results of Examples 46-48.

<Example 49>
In Example 49, the composite material of Example 5 was used as a sputtering target, and a film was formed on a substrate made of borosilicate glass to prepare a thin-film coated member. The target standard was 3 inches in diameter and 5 mm in thickness. The composite was adhesively attached to a copper backing plate and used for sputter deposition.

Sputtering film formation conditions: RF magnetron sputtering method, sputtering gas pressure of 1 Pa, sputtering power of 4.4 W/cm ² , target-substrate distance of 8 cm
The evaluation was performed based on target strength (confirmed by the presence or absence of cracks or breakage during sputtering), film composition/state evaluation (XPS), and film characteristics evaluation (spectral characteristics).

Regarding the strength of the target, it was confirmed that it had sufficient strength because it did not crack or break during sputtering.

FIG. 2 shows the spectral characteristics of the CeO ₂ -PTFE-In film of the manufactured thin-film-coated member. A thin film of about 100 nm formed by sputtering using a CeO ₂ -PTFE-In composite material as a target exhibited a high light shielding rate for ultraviolet light (<380 nm) compared to Corning glass. Also, the CeO ₂ -PTFE-In film of 103.6 nm showed a high transmittance of 85% or more around 500 nm, which has the highest visibility. As the CeO ₂ -PTFE-In film is thickened (122.2 nm), interference with the substrate Corning glass appears. Light absorption in the near-infrared to infrared region is small.

FIG. 3 shows the nanoindenter hardness of the CeO ₂ -PTFE-In film of the manufactured thin-film coated member. Although the hardness of the film is low compared to the case where a CeO ₂ film is formed on glass, the hardness is sufficiently high compared to the PTFE film or the glass itself. Specifically, the nanoindenter hardness of the sputtered CeO ₂ film was about twice that of the substrate Corning glass (borosilicate glass). The nanoindenter hardness of the CeO ₂ -PTFE-In film that shields ultraviolet light is about 8 MPa, which is higher than that of the substrate borosilicate glass. The nanoindenter hardness of the sputter-deposited PTFE film is about 1 GPa, which is three times that of the bulk PTFE plate.

FIG. 4 shows the water contact angle of the CeO ₂ -PTFE-In film of the manufactured thin film coated member. Time-of-flight mass spectrometry performed separately confirmed that PTFE decomposes into C, F, CF, CF ₂ and CF ₃ by sputtering and evaporates. As shown in FIG. 4, the CeO ₂ , CeO ₂ -PTFE and PTFE films all exhibit higher water contact angles than the glass substrate. A high contact angle is an indicator of water repellency, and indicates that the CeO ₂ -PTFE-In film has a water-repellent function of repelling water.

In addition, the thin film coated member described above includes a glass workpiece and a thin film formed on the surface of the workpiece by sputtering. , and Bi.

The method of manufacturing the thin-film coated member includes mixing metal oxide powder, fluororesin powder, and metal material powder to obtain a mixture, and compression-molding the mixture to obtain a molded product. , firing the molded product at a temperature of 100° C. or higher and 350° C. or lower to obtain a sintered body; and using the sintered body as a sputtering target to form a thin film on a predetermined work by sputtering. .

[4. effect]
According to the composite material of the present disclosure detailed above, the following effects are obtained.

(4a) According to the composite material and the method for manufacturing the composite material of the present disclosure, the lack of mechanical strength due to low-temperature sintering performed due to the lack of heat resistance of the organic material can be resolved. Even polytetrafluoroethylene (PTFE), which is a fluorine resin with excellent heat resistance, has a heat resistance of about 300 ° C, so it is difficult to sinter at high temperatures, and conventional composite materials have low mechanical strength. . However, the composite material of the present disclosure can obtain high mechanical strength even with low temperature sintering.

(4b) The composite material of the example does not contain an organic binder such as acrylic. Therefore, it is suppressed to affect the binder composite material.

[5. Industrial Applicability]
The sputtering method is widely used for surface treatment of digital signage devices using large flat panel displays, automobiles, and windows of buildings and houses. On the other hand, inorganic substances such as metals, oxides, nitrides, carbides and sulfides, composite inorganic compounds thereof, and organic compounds such as fluororesins have been used as sputtering targets for a long time.

In recent years, research and development has begun on organic-inorganic hybrid films that combine the advantages of both inorganic and organic materials. Methods of producing such a hybrid film by sputtering include (i) a method of forming an inorganic target and an organic target simultaneously. However, this method is not preferable as a production technique because the discharge may become unstable due to mutual interference of discharges on different targets arranged at close range.

Another method is (ii) a method of using an organic-inorganic composite target (organic-inorganic composite target). In this method, a mixture of different inorganic compound powders and organic compound powders is normally pressed at 1 to 1.5 t/cm ² at room temperature (cold press method) and sintered at about 100 ° C. to 350 ° C., or It is performed by a hot press method in which temperature-rising molding and sintering are performed at a temperature of about 100°C to 350°C.

However, the mechanical strength of the low-temperature sintered composite material, which is a mixed powder containing inorganic materials and organic materials (fluororesin, etc.), is extremely weak, and there were major problems in actual use due to cracks and fractures during mass production. Also, in the cold press method, it is necessary to maintain the shape of the composite material from the time of molding the composite powder at room temperature to sintering at 100° C. to 350° C. (preferably up to 300° C.). For the purpose of maintaining the shape at the time of molding, generally, several percent of a resin binder (acrylic, etc.) is mixed at the time of molding to produce a molded body. If only the inorganic material is used, the resin binder is scattered during the subsequent high-temperature sintering (1000° C. or higher) and does not remain in the sintered body. However, since the sintering temperature of the organic-inorganic composite is as low as 300° C. or less, there is concern that the organic binder may remain in the composite and affect the composite. In the present disclosure, by using a low-melting-point metal instead of acrylic, the metal material melts and spreads between particles at the sintering temperature to exhibit a binder effect. In addition, for example, the In binder can be sintered at 300° C. or lower, and the target can be densified and strengthened by sintering. Therefore, according to the technique of the present disclosure, a composite material with high strength can be produced with a reduced amount of organic binder or without using it, and the above-described problems can be solved. It should be noted that although the present disclosure allows the content of the organic binder to be reduced, it does not preclude the inclusion of an organic material that functions as a binder, if necessary or according to purpose.

[6. Other embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is by no means limited to the above-described embodiments, and needless to say, can take various forms as long as they fall within the technical scope of the present disclosure.

(6A) The composite material of the present disclosure is not limited to combinations of elements and compounds described as examples, and various combinations within the technical scope of the present disclosure are possible. That is, the metal material should at least contain one or more selected from the group including In, Sn, and Bi. Moreover, the metal oxide to be combined may include one or more selected from the group including Ce, Y, Al, Si and Nb, or may be other metals. Moreover, the fluororesin to be combined is not limited to the resins specifically exemplified in the embodiments.

(6B) The composite material can be used as a sputtering target, but it may of course be used for other purposes. In addition, although the glass substrate is exemplified as the workpiece on which the film is formed, the thin film covering member may be formed on other materials.

Claims

a matrix of metal oxides;
fluororesin;
one or more metal materials selected from the group containing In, Sn, and Bi;
Composite materials, including
A composite material according to claim 1,
The composite material, wherein the metal oxide contains one or more metal elements selected from the group containing Ce, Y, Al, Si, and Nb.
A composite material according to claim 1 or claim 2,
The mixed weight ratio of the metal oxide and the fluororesin is in the range of 20:1 to 1:1,
A composite material in which the metal material is 0.1% by weight or more and 50% by weight or less when the total weight of the metal oxide, the fluororesin, and the metal material is 100%.
A composite material according to claim 3,
A composite material in which a composite compound phase of a metal fluoride or a fluorocarbon is formed between the metal oxide and the fluororesin and between the metal material and the fluororesin.
A composite material according to any one of claims 1 to 4,
The fluororesin is selected from the group including polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-ethylene copolymer and polyvinylidene fluoride. Composite material comprising at least one or more
A sputtering target composed of the composite material according to any one of claims 1 to 5.
Work and
a thin film formed by sputtering on the surface of the work,
The thin film-coated member, wherein the thin film includes a metal oxide matrix, a fluororesin, and at least one metal material selected from the group including In, Sn, and Bi.
A method of manufacturing a composite material, comprising:
obtaining a mixture by mixing a material powder containing a metal oxide powder, a fluororesin powder, and a metal material powder;
compression molding the mixture to obtain a molded product;
obtaining a sintered body by sintering the molded product at 100° C. or higher and 350° C. or lower;
including
The method for producing a composite material, wherein the metal material powder contains one or more metal materials selected from the group containing In, Sn, and Bi.
obtaining a mixture by mixing a material powder containing a metal oxide powder, a fluororesin powder, and a metal material powder;
compression molding the mixture to obtain a molded product;
obtaining a sintered body by sintering the molded product at 100° C. or higher and 350° C. or lower;
forming a thin film on a predetermined workpiece by sputtering using the sintered body as a sputtering target;
The method for producing a thin-film coated member, wherein the metal material powder contains one or more metal materials selected from the group containing In, Sn, and Bi.