Rubber molded products

Abstract

To give an excellent plasma resistance to a rubber molding and to prevent a compound having a perfluoro-polyether skeleton from bleeding out.SOLUTION: There is provided a rubber molding in which a fluororubber composition comprising a component A of a base rubber containing a hydrogen-containing fluororubber as a main component, a component B of a compound having a perfluoro-polyether skeleton and a component C of a powder filler having a bulk density of 0.4 g / cm3 or less and having a ratio of the content of the component C to the content of the component B of larger than 0.1 in which a part or the whole of the component B contains an alkenyl group in the molecule is cross-linked and formed. The rubber molding has a higher CF bond concentration on the surface of the molding than the inside of the molding.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a rubber molded article. [Background technology]

[0002] Fluororubber compositions are widely used as sealing materials for semiconductor manufacturing equipment. Patent Document 1 discloses that the fluororubber composition forming the sealing material contains a compound having a perfluoropolyether skeleton in order to improve its plasma resistance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4675907 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when a compound having a perfluoropolyether skeleton is contained in a fluororubber composition forming a sealing material, there is a problem that the compound bleeds out from the sealing material.

[0005] An object of the present invention is to allow a rubber molded article to maintain excellent plasma resistance and to inhibit the bleeding out of a compound having a perfluoropolyether skeleton from the rubber molded article. [Means for solving the problem]

[0006] The present invention relates to a rubber composition comprising a base rubber component A containing a hydrogen-containing fluororubber as a main component, a compound component B having a perfluoropolyether skeleton, and a polymer having a bulk density of 0.4 g / cm 3 and a powder filler C component as follows: 0.12 or greaterThe rubber molded article is formed by crosslinking a fluororubber composition, and the surface of the molded article has a higher C—F bond concentration than the interior of the molded article.

[0007] The present invention relates to a rubber composition comprising a base rubber component A containing a hydrogen-containing fluororubber as a main component, a compound component B having a perfluoropolyether skeleton, and a polymer having a bulk density of 0.4 g / cm 3 and a powder filler C component as follows: 0.12 or greater A rubber molded article formed by crosslinking a fluororubber composition, wherein the peak area of ​​282 to 288 eV derived from a C1s peak attributable to a C-H bond measured by X-ray photoelectron spectroscopy is A CH The peak area at 288 to 296 eV due to the C—F bond is A CF When X-rays are irradiated onto the surface of the molded product, CF / A CH ) / (A when X-rays are irradiated at the farthest point from the surface of the molded product in the cross section of the molded product CF / A CH )≧2. [Effects of the Invention]

[0008] According to the present invention, it is possible to maintain excellent plasma resistance in a rubber molded article and to prevent the compound having a perfluoropolyether skeleton from bleeding out from the rubber molded article. DETAILED DESCRIPTION OF THE INVENTION

[0009] The embodiments will be described in detail below.

[0010] The fluororubber composition according to the embodiment contains an A component, a B component, and a C component.

[0011] Component A is a base rubber. Component A of this base rubber contains hydrogen-containing fluororubber as a main component. Here, the "hydrogen-containing fluororubber" in the present application refers to a fluororubber containing carbon with hydrogen bonded to the main chain of a polymer. The content of hydrogen-containing fluororubber in Component A is more than 50% by mass, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 100% by mass. Note that Component A may contain fluororubbers other than the hydrogen-containing fluororubber.

[0012] Examples of hydrogen-containing fluororubbers include polymers of vinylidene fluoride (VDF) (PVDF), copolymers of vinylidene fluoride (VDF) and hexafluoropropylene (HFP), copolymers of vinylidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE), copolymers of tetrafluoroethylene (TFE) and propylene (Pr) (FEP), copolymers of vinylidene fluoride (VDF), propylene (Pr), and tetrafluoroethylene (TFE), copolymers of ethylene (E) and tetrafluoroethylene (TFE) (ETFE), copolymers of ethylene (E), tetrafluoroethylene (TFE), and perfluoromethyl vinyl ether (PMVE), copolymers of vinylidene fluoride (VDF), tetrafluoroethylene (TFE), and perfluoromethyl vinyl ether (PMVE), copolymers of vinylidene fluoride (VDF) and perfluoromethyl vinyl ether (PMVE), and the like. Component A preferably contains one or more of these as the hydrogen-containing fluororubber, and more preferably contains a vinylidene fluoride-based fluororubber (FKM) containing vinylidene fluoride as the main component, such as a copolymer of vinylidene fluoride (VDF) and hexafluoropropylene (HFP) or a copolymer of vinylidene fluoride (VDF), hexafluoropropylene (HFP), and tetrafluoroethylene (TFE).

[0013] Component B is a compound having a perfluoropolyether skeleton. Component B's compound having a perfluoropolyether skeleton is a liquid material uniformly mixed with component A. Component B contains alkenyl groups in part or in whole within the molecule. Examples of alkenyl groups include vinyl groups, allyl groups, butenyl groups, pentenyl groups, hexenyl groups, and heptenyl groups. Of these, vinyl groups are preferred as the alkenyl group. It is preferred that there are multiple alkenyl groups within the molecule. In this case, the multiple alkenyl groups within the molecule may be the same or different.

[0014] Component B may contain both those containing an alkenyl group in the molecule and those not containing an alkenyl group in the molecule. The proportion of those containing an alkenyl group in the molecule in component B is preferably 20% by mass or more, more preferably 30% by mass or more.

[0015] Density d of component B B is preferably 1.5 g / cm from the viewpoint of maintaining excellent plasma resistance in a rubber molded article formed using the fluororubber composition according to the embodiment as described below, and suppressing bleeding out of component B from the rubber molded article. 3 More preferably, 1.8 g / cm 3 From the same viewpoint, it is preferably 2.5 g / cm 3 or less, more preferably 2.0 g / cm 3 If component B contains multiple compounds, the density of component B, d B is the sum of the products of the densities and the content fractions of each component. The density d of component B containing alkenyl groups in the molecule is B is measured by the gas pycnometer method specified in JIS Z8837:2018. The density d of component B, which does not contain an alkenyl group in the molecule, is B is measured at a temperature of 20°C by the vibration type density meter method specified in JIS K0061:2001.

[0016] Content of component B per 100 parts by mass of component A p Bis preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, from the viewpoint of obtaining high plasma resistance of the rubber molded article, and is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, from the viewpoint of maintaining excellent plasma resistance of the rubber molded article and suppressing bleeding out of the component B from the rubber molded article. When the component B contains multiple types of compounds, the content p of the component B B is the sum of the respective contents.

[0017] Commercially available materials for the compound having a perfluoropolyether skeleton containing an alkenyl group in the molecule in component B include, for example, SIFEL manufactured by Shin-Etsu Chemical Co., Ltd., and the SIFEL3000 series is particularly preferred. The compound having a perfluoropolyether skeleton containing an alkenyl group in the molecule is preferably a one-component material.

[0018] Examples of commercially available materials of the compound having a perfluoropolyether skeleton containing no alkenyl groups in the molecule of Component B include Fomblin Y lubricant manufactured by SOLVAY and Krytox GPL oil manufactured by Chemours.

[0019] Component C is dispersed in component A with a bulk density of d C is 0.4g / cm 3 The powder fillers are as follows. Examples of powder fillers for component C include silica, resin powder, silicon carbide, boron carbide, silicon nitride, and boron nitride. Component C preferably contains one or more of these, and more preferably contains silica and / or resin powder. The silica may be either dry silica or wet silica. The silica may be either surface-untreated hydrophilic silica or hydrophobic silica surface-modified with dimethyldichlorosilane or the like. Examples of resin powders include phenolic resin powder, fluororesin powder, and polyetheretherketone (PEEK) resin powder.

[0020] Bulk density d of powder filler of component C Cis preferably 0.01 g / cm from the viewpoint of maintaining excellent plasma resistance in the rubber molded article and suppressing the bleeding out of component B from the rubber molded article. 3 More preferably, 0.03 g / cm 3 From the same viewpoint, it is preferably 0.35 g / cm 3 or less, more preferably 0.20 g / cm 3 When component C contains multiple types of powder fillers, the bulk density d C is the sum of the products of the bulk density and the content fraction of each component. Bulk density d of component C C is measured in accordance with the method for measuring tapped bulk density specified in JIS R1628-1997.

[0021] The content of component C relative to 100 parts by mass of component A is p C is preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, from the viewpoint of maintaining excellent plasma resistance in the rubber molded article and suppressing bleeding out of component B from the rubber molded article, and is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, from the viewpoint of suppressing precipitation of powder filler from the rubber molded article. When component C contains multiple types of powder fillers, the content p of component C is C is the sum of the respective contents.

[0022] C component content p C is the content p of component B from the viewpoint of suppressing the precipitation of powder filler from the rubber molded product and suppressing the bleeding out of component B from the rubber molded product. B The content of component C is preferably p C The content of B component p B Ratio to (p C / p B From the same viewpoint, ) is preferably greater than 0.1 and equal to or less than 30, more preferably 0.12 or more and 25 or less, and even more preferably 1.0 or more and 20 or less.

[0023] Commercially available materials for component C include silica such as the Aerosil series and Carplex series manufactured by Evonik. Phenolic resin powders include the Bellpearl series manufactured by Air Water Bellpearl. Fluororesin powders include the Kynar series manufactured by Arkema. Polyetheretherketone (PEEK) resin powders include the VESTAKEEP series manufactured by Daicel-Evonik.

[0024] In the fluororubber composition according to the embodiment, (p C / d C ) / (p B / d B )≧4 is preferable. This means that the volume of component C is four times or more the volume of component B. From the viewpoint of maintaining excellent plasma resistance in the rubber molded article and suppressing the bleeding out of component B from the rubber molded article, it is more preferable that (p C / d C ) / (p B / d B )≧10, more preferably (p C / d C ) / (p B / d B )≧50.

[0025] The fluororubber composition according to the embodiment may further contain a crosslinking agent. Examples of the crosslinking agent include organic peroxides, polyols, polyamines, triazines, etc. Of these, the organic peroxides are preferred as the crosslinking agent.

[0026] Examples of organic peroxides include 1,1-bis(t-butylperoxy)-3,5,5-trimethylcyclohexane, 2,5-dimethylhexane-2,5-dihydroperoxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α,α-bis(t-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)-hexyne-3, benzoyl peroxide, t-butylperoxybenzene, t-butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, etc. The crosslinking agent preferably contains one or more of these, and more preferably contains 2,5-dimethyl-2,5-di(t-butylperoxy)hexane.

[0027] The content of the crosslinking agent relative to 100 parts by mass of the component A is preferably 0.5 parts by mass or more and 2.5 parts by mass or less, and more preferably 0.5 parts by mass or more and 2.0 parts by mass or less.

[0028] The fluororubber composition according to the embodiment may further contain a crosslinking aid. Examples of the crosslinking aid include triallyl cyanurate, trimethallyl isocyanurate, triallyl isocyanurate, triacryl formal, triallyl trimellitate, N,N'-m-phenylene bismaleimide, dipropargyl terephthalate, diallyl phthalate, tetraallyl terephthalate amide, triallyl phosphate, bismaleimide, and fluorinated triallyl isocyanurate (1,3,5-tris(2,3,3-trifluoro-2-propenyl)-1,3,5-triazine). Examples of suitable crosslinking aids include tris(diallylamine)-S-triazine, triallyl phosphite, N,N-diallylacrylamide, 1,6-divinyldodecafluorohexane, hexaallyl phosphoramide, N,N,N',N'-tetraallylphthalamide, N,N,N',N'-tetraallylmalonamide, trivinyl isocyanurate, 2,4,6-trivinylmethyltrisiloxane, tri(5-norbornene-2-methylene)cyanurate, and triallyl phosphite. The crosslinking aid preferably contains one or more of these, and more preferably contains triallyl isocyanurate.

[0029] The content of the crosslinking aid relative to 100 parts by mass of the component A is preferably 1 part by mass or more and 10 parts by mass or less, and more preferably 2 parts by mass or more and 5 parts by mass or less.

[0030] When the fluororubber composition according to the embodiment having the above configuration is crosslinked, it becomes a crosslinked rubber and a rubber molded article is formed. The crosslinking of the fluororubber composition according to the embodiment forms a crosslinked structure between the molecules of the component A by the action of the crosslinking agent due to heating or the action of radiation irradiation. In addition, the component B or the crosslinking aid containing an alkenyl group in the molecule reacts with the component A and becomes interposed between the molecules of the component A, thereby forming a crosslinked structure.

[0031] In the rubber molded article formed by crosslinking the fluororubber composition according to the embodiment, a compound having a perfluoropolyether skeleton as component B is used, which allows the article to maintain excellent plasma resistance. Specifically, mass loss can be reduced even when exposed to plasma. At the same time, bleeding out of component B can be suppressed. This is presumably because component C powder filler is used, and the volume of component C is much larger than that of component B, so component B is supported by component C and held within component A. Furthermore, the bulk density of the powder filler for component C is 0.4 g / cm. 3 By making the particle size smaller than or equal to 100 nm, it is possible to prevent the precipitation of particles of the powder filler of component C even when irradiated with plasma.

[0032] Furthermore, in the rubber molded article formed by crosslinking the fluororubber composition according to the embodiment, the viscosity is increased during molding because the fluororubber composition contains the powder filler (component C), which facilitates the flow of the compound having a perfluoropolyether skeleton (component B). As a result, component B segregates to the surface, resulting in a higher C—F bond concentration at the surface of the molded article than inside the molded article. This reduces the number of C—H bonds on the surface of the molded article that can be attacked by plasma and cause deterioration, thereby improving plasma resistance. Quantitatively, the peak area at 282 to 288 eV due to C—H bonds in the C1s peak measured when irradiated with X-rays using X-ray photoelectron spectroscopy is expressed as A. CH The peak area at 288 to 296 eV due to the C—F bond is A CF When X-rays are irradiated onto the surface of the molded product, CF / A CH ) / (A when X-rays are irradiated at the farthest point from the surface of the molded product in the cross section of the molded product CF / A CH ) ≥ 2. This ratio is preferably 2.5 or more from the viewpoints of maintaining excellent plasma resistance in the rubber molded article and suppressing bleeding out of component B from the rubber molded article.

[0033] The rubber molded article formed by crosslinking the fluororubber composition according to the embodiment is not particularly limited, but is preferably a sealing material, more preferably a sealing material for semiconductor manufacturing equipment.

[0034] The hardness of the crosslinked rubber obtained by crosslinking the fluororubber composition according to the embodiment, measured with a type A durometer in accordance with JIS K6253-3:2012, is preferably 50A or more, more preferably 55A or more, and is preferably 95A or less, more preferably 90A or less.

[0035] The crosslinked rubber obtained by crosslinking the fluororubber composition according to the embodiment has a tensile strength at break measured at a standard test temperature using a 2 mm thick dumbbell-shaped No. 3 test piece according to JIS K6251:2017 of preferably 5.0 MPa or more, more preferably 10.0 MPa or more. The elongation at break is preferably 50% or more, more preferably 100% or more. The tensile stress at 100% elongation is preferably 1.0 MPa or more, more preferably 1.5 MPa or more.

[0036] The crosslinked rubber obtained by crosslinking the fluororubber composition according to the embodiment has a compression set measured in accordance with JIS K6262:2013 at a test time of 72 hours and a test temperature of (200±2)°C of preferably 80% or less, more preferably 50% or less. [Example]

[0037] (sealing material) The following sealing materials were prepared in Examples 1 to 13 and Comparative Examples 1 to 7. The respective configurations are also shown in Tables 1 and 2. The density of the compound having a perfluoropolyether skeleton was measured by the gas pycnometer method specified in JIS Z8837:2018 when it contained an alkenyl group in the molecule, and by the vibration densitometer method specified in JIS K0061:2001 at a temperature of 20°C when it did not contain an alkenyl group in the molecule. The bulk density of the powder filler was measured in accordance with the tap bulk density measurement method specified in JIS R1628-1997.

[0038] Example 1 The component A was a hydrogen-containing fluororubber (Dai-el G912, manufactured by Daikin Industries, Ltd.) made of a copolymer of vinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene. 100 parts by mass of the component A was mixed with 100 parts by mass of the component B, a one-component liquid material, Compound 1 (SIFEL3000 series X-71-359, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether skeleton containing a vinyl group in the molecule. B :1.85g / cm 3 )1 part by mass (p B ), and the powder filler of component C, surface-untreated hydrophilic dry silica 1 (Aerosil 200 manufactured by Evonik, bulk density d C :0.05g / cm 3 )10 parts by mass (p C A fluororubber composition was prepared by blending 1.5 parts by mass of 2,5-dimethyl-2,5-di(t-butylperoxy)hexane (Perhexa 25B, manufactured by Nippon Oil & Fats Corporation), an organic peroxide crosslinking agent, and 4 parts by mass of triallyl isocyanurate (Taiku, manufactured by Nippon Kasei Chemical Industry Co., Ltd.), and kneading them with an open roll. A sealing material (AS-214 O-ring) was then produced by crosslinking this fluororubber composition. The crosslinking of the fluororubber composition was performed by press molding at 160°C for 10 minutes to perform primary crosslinking, and then by holding the composition in a gear oven set at 200°C for 4 hours to perform secondary crosslinking. The resulting sealing material was designated Example 1.

[0039] <Example 2> As the powder filler for component C, hydrophobic fumed silica 2 (Aerosil R972 manufactured by Evonik, bulk density d) surface-treated with dimethyldichlorosilane was used. C :0.05g / cm 3 ) to 100 parts by mass of component A, 0.2 parts by mass (p C A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by blending the above-mentioned components. The resulting sealing material was designated as Example 2.

[0040] Example 3 A sealing material was produced in the same manner as in Example 1, except that the fluororubber composition was prepared by blending the dry silica 2 used in Example 2 as the powder filler of component C. The resulting sealing material was designated Example 3.

[0041] Example 4 As the powder filler of component C, wet silica (Carplex #80 manufactured by Evonik, bulk density d C :0.15g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by blending the above-mentioned components. The resulting sealing material was designated as Example 4.

[0042] <Example 5> As component B, a liquid material, Compound 1 (Fomblin Y lubricant, manufactured by SOLVAY, density: 1.91 g / cm), having a perfluoropolyether skeleton that does not contain an alkenyl group in the molecule, was used. 3 A sealing material was produced in the same manner as in Example 3, except that 1 part by mass of Component B was further blended with 100 parts by mass of Component A to prepare a fluororubber composition. The resulting sealing material was designated Example 5. The density d B is 1.88g / cm 3 is.

[0043] Example 6 A sealing material was produced in the same manner as in Example 3, except that a fluororubber composition was prepared by blending 5 parts by mass of Compound 1 having a perfluoropolyether skeleton containing a vinyl group in the molecule, which is a one-component liquid material of Component B, with 100 parts by mass of Component A. The resulting sealing material was designated Example 6.

[0044] Example 7 As component B, compound 2 having a perfluoropolyether skeleton containing no alkenyl groups in the molecule (Krytox GPL Oil 107, manufactured by Chemours, density: 1.90 g / cm 3A sealing material was produced in the same manner as in Example 3, except that 1 part by mass of Component B was further blended with 100 parts by mass of Component A to prepare a fluororubber composition. The resulting sealing material was designated Example 7. The density d B is 1.88g / cm 3 is.

[0045] Example 8 A sealing material was produced in the same manner as in Example 5, except that a fluororubber composition was prepared by blending 5 parts by mass of Compound 1, which is a liquid material for Component B and has a perfluoropolyether skeleton containing no alkenyl groups in the molecule, with 100 parts by mass of Component A. The resulting sealing material was designated Example 8. The density d B is 1.90g / cm 3 is.

[0046] Example 9 Compound 2(d) having a perfluoropolyether skeleton containing a vinyl group in the molecule, which is a one-component liquid material of component B B :1.90g / cm 3 ) and silica (d C :0.05g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by blending 1 part by mass of a mixed material (SIFEL3000 series X-71-369-N, manufactured by Shin-Etsu Chemical Co., Ltd.) in which Component B and Component C were mixed in a mass ratio of 89:11. The resulting sealing material was designated Example 9.

[0047] Example 10 As the powder filler of component C, phenolic resin powder 1 (Bellpearl R100 manufactured by Air Water Bellpearl Co., Ltd., bulk density d C :0.35g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by blending the above-mentioned fluorine-containing rubber component (A) and the fluorine-containing rubber component (B). The obtained sealing material was designated as Example 10.

[0048] Example 11 As the powder filler of component C, phenolic resin powder 2 (Bellpearl R200 manufactured by Air Water Bellpearl Co., Ltd., bulk density d C :0.38g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by blending the above-mentioned components. The resulting sealing material was designated as Example 11.

[0049] Example 12 As the powder filler of component C, fluororesin (PVDF) powder (Kynar MG15 manufactured by Arkema, bulk density d C :0.32g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by compounding the above-mentioned fluorine-containing rubber component (A) and the fluorine-containing rubber component (B). The obtained sealing material was designated as Example 12.

[0050] Example 13 As the powder filler of component C, polyether ether ketone (PEEK) resin powder (VESTAKEEP 2000UFP10, manufactured by Daicel-Evonik Co., Ltd., bulk density d C :0.25g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by blending the above-mentioned components. The resulting sealing material was designated as Example 13.

[0051] <Comparative Example 1> A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared without blending components B and C. The resulting sealing material was designated Comparative Example 1.

[0052] <Comparative Example 2> A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared without compounding component C. The obtained sealing material was designated as Comparative Example 2.

[0053] <Comparative Example 3> A sealing material was produced in the same manner as in Example 5, except that a fluororubber composition was prepared that did not contain Compound 1 having a perfluoropolyether skeleton containing a vinyl group in the molecule, which is a one-component liquid material of Component B. The resulting sealing material was designated Comparative Example 3.

[0054] <Comparative Example 4> Instead of component C, phenolic resin powder 3 (Bellpearl R800, manufactured by Air Water Bellpearl Co., Ltd., bulk density d C :0.60g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by compounding the above-mentioned components. The obtained sealing material was designated as Comparative Example 4.

[0055] <Comparative Example 5> Instead of component C, a fluororesin (PTFE) powder (Lubron L-5, manufactured by Daikin Industries, Ltd., bulk density d C :0.61g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by compounding the above-mentioned components. The obtained sealing material was designated as Comparative Example 5.

[0056] <Comparative Example 6> Instead of component C, MT carbon black (Thermax N990 manufactured by Cancarb, bulk density d C :0.66g / cm 3 A sealing material was produced in the same manner as in Example 1, except that a fluororubber composition was prepared by compounding the above-mentioned components. The obtained sealing material was designated as Comparative Example 6.

[0057] <Comparative Example 7> A sealing material was produced in the same manner as in Example 2, except that 1 part by mass of Compound 1 having a perfluoropolyether skeleton containing no alkenyl groups in the molecule, which is the liquid material used in Example 5, was further blended with 100 parts by mass of Component A to prepare a fluororubber composition as Component B. The resulting sealing material was designated Comparative Example 7. The density d B is 1.88g / cm 3It is.

[0058]

Table 1

[0059]

Table 2

[0060] (Test method) <Plasma resistance> For each of Examples 1 to 13 and Comparative Examples 1 to 7, they were placed in a small plasma etching apparatus (manufactured by Shinko Seiki Co., Ltd.), irradiated with O2 plasma for 30 minutes for exposure, and the mass reduction rate before and after that was determined. When the mass reduction rate was less than 0.7%, it was evaluated as A, and when it was 0.7% or more, it was evaluated as B. Also, regarding the surface of the sealing material after O2 plasma exposure, the presence or absence of particle deposition was visually confirmed. In the irradiation of O2 plasma, a 1500 W high-frequency power supply was used. As the reaction gases, O2 and CF4 were used, and their flow rate ratio was set to 50:1. The pressure was set to 100 Pa.

[0061] <Presence or absence of bleed-out of component B> For each of Examples 1 to 13 and Comparative Examples 2 to 7, they were pressed against a black acrylic plate. When no transfer marks of the sealing material due to component B were observed, it was evaluated as A, and when transfer marks of the sealing material due to component B were observed, it was evaluated as B.

[0062] <XPS measurement> For each of Examples 1 to 13 and Comparative Examples 1 to 7, for each of the sealing material surface and the cross-section of the sealing material, by X-ray photoelectron spectroscopy, the peak area of 282 - 288 eV derived from CH bonds in the C1s peak measured when irradiated with X-rays was A CH and the peak area of 288 - 296 eV derived from CF bonds was A CF and measured. And, (A CF / A CH when irradiating X-rays on the sealing material surface) / (A when X-rays are irradiated at the farthest point from the sealant surface in the sealant cross section CF / A CH ) was calculated. When this ratio was 2 or more, it was rated as A, and when it was less than 2, it was rated as B. Here, the position farthest from the surface of the sealing material in the cross section of the sealing material was the center of the circle in the cross section of the O-ring that was the sealing material.

[0063] In X-ray photoelectron spectroscopy, data shift occurs due to charging. Therefore, based on the XPS data of fluororubber (Viton A, manufactured by DuPont Elastomers) recorded in the NIST X-ray Photoelectron Spectroscopy Database (https: / / srdata.nist.gov / xps / Default.aspx), the F1s peak was set to 688.80, and the peak area A of the C1s peak at 282-288 eV, which is derived from C-H bonds, was calculated. CH and the peak area A of 288-296 eV due to C—F bonds CF asked for.

[0064] <Hardness> The hardness of the crosslinked rubber forming each of Examples 1 to 13 and Comparative Examples 1 to 7 was measured using a type A durometer in accordance with JIS K6253-3:2012.

[0065] <Tensile properties> For the crosslinked rubbers forming each of Examples 1 to 13 and Comparative Examples 1 to 7, a tensile test was carried out at a standard test temperature using a dumbbell-shaped No. 3 test piece having a thickness of 2 mm in accordance with JIS K6251:2017, and the tensile strength at break, elongation at break, and tensile stress at 100% elongation were measured.

[0066] <Compression set> Each of Examples 1 to 13 and Comparative Examples 1 to 7 was cut in half to obtain a test piece, and the compression set was measured for the test piece at a test time of 72 hours and a test temperature of (200±2)° C. in accordance with JIS K6262:2013.

[0067] (Test results) The test results are shown in Tables 1 and 2. Tables 1 and 2 show that Examples 1 to 13 have both excellent plasma resistance, i.e., a small mass loss rate, and suppression of bleed-out of component B, whereas Comparative Examples 1 to 7 are inferior in one of these respects. [Industrial Applicability]

[0068] The present invention is useful in the technical field of rubber molded products.

Claims

1. A component A of a base rubber containing a hydrogen-containing fluororubber as a main component, a component B of a compound having a perfluoropolyether skeleton, and a bulk density of 0.4 g / cm ３ A rubber molded article formed by crosslinking a fluororubber composition containing the following powder filler: Component C; a part or all of Component B containing an alkenyl group in the molecule; and a ratio of the content of Component C to the content of Component B of 0.12 or more: A rubber molded product in which the CF bond concentration is higher on the surface than inside the molded product.

2. A component A of a base rubber containing a hydrogen-containing fluororubber as a main component, a component B of a compound having a perfluoropolyether skeleton, and a bulk density of 0.4 g / cm ３ A rubber molded article formed by crosslinking a fluororubber composition containing the following powder filler: Component C; a part or all of Component B containing an alkenyl group in the molecule; and a ratio of the content of Component C to the content of Component B of 0.12 or more: The peak area of ​​282 to 288 eV due to the C1s peak, which is derived from a C-H bond and measured when irradiated with X-rays by X-ray photoelectron spectroscopy, is determined as A ＣＨ The peak area at 288 to 296 eV due to the CF bond is A ＣＦ When X-rays are irradiated onto the surface of the molded product, ＣＦ / A ＣＨ ) / (A when X-rays are irradiated at the position farthest from the surface of the molded product in the cross section of the molded product ＣＦ / A ＣＨ ) ≧2.

3. The rubber molded article according to claim 1 or 2, The rubber molded article is a sealing material.

4. The rubber molded article according to claim 3, The rubber molded product is a sealing material for semiconductor manufacturing equipment.

5. The rubber molded article according to claim 1 or 2, A rubber molded article, wherein the component A comprises a copolymer of vinylidene fluoride, hexafluoropropylene and tetrafluoroethylene.

6. The rubber molded article according to claim 1 or 2, A rubber molded article, wherein the proportion of components containing alkenyl groups in the molecules of the component B is 20 mass % or more.

7. The rubber molded article according to claim 1 or 2, The density of the B component is 1.5 g / cm ３ 2.5g / cm or more ３ A rubber molded product that is:

8. The rubber molded article according to claim 1 or 2, A rubber molded article, wherein the content of the component B relative to 100 parts by mass of the component A is 0.1 parts by mass or more and 20 parts by mass or less.

9. The rubber molded article according to claim 1 or 2, The compound having a perfluoropolyether skeleton containing an alkenyl group in the molecule is a one-component material.

10. The rubber molded article according to claim 1 or 2, A rubber molded article, wherein the component C contains silica and / or resin powder.

11. The rubber molded article according to claim 1 or 2, A rubber molded article, wherein the content of the component C relative to 100 parts by mass of the component A is 0.1 parts by mass or more and 30 parts by mass or less.

12. The rubber molded product according to claim 1 or 2, A rubber molded article, wherein all of the components B contain alkenyl groups in the molecule, and the ratio of the content of the component C to the content of the component B in the fluororubber composition is 0.2 or more.

13. The rubber molded product according to claim 1 or 2, A rubber molded article, wherein a part of the component B contains an alkenyl group in the molecule, and the remainder of the part of the component B does not contain an alkenyl group in the molecule, and the ratio of the content of the component C to the content of the component B in the fluororubber composition is 5 or more.

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