JP7458913B2 - Rubber materials for gaskets and gaskets - Google Patents

Description

The present invention relates to a rubber material for a gasket and a gasket.

Gaskets made of a laminated rubber layer and metal base material are currently used in various fields such as automobiles. Gaskets are required to have high sealing performance, and for this purpose, improvements in compression set resistance (CS), stress relaxation properties, and rubber hardness are being considered. For example, Patent Document 1 discloses a metal gasket in which a plurality of metal sheets and a sealing material made of an elastic body are laminated.

In recent years, hybridization and electrification of automobiles have progressed, and environmentally friendly vehicles such as fuel cell vehicles are being developed. These automobiles use gaskets for motors, gaskets for batteries such as secondary batteries and fuel cells, and gaskets for power control units. Environmentally friendly vehicles such as hybrid vehicles, electric vehicles, and fuel cell vehicles use motors, which generate vibrations when the motors are driven. Therefore, it is desired to suppress vibrations generated in these environmentally friendly vehicles and vibrations originating from other devices such as motors.

Further, since gaskets are generally required to have gasket functions suitable for various uses, improvements in gasket functions are required. Therefore, it is desired to improve not only the gasket function but also the vibration damping and vibration isolation properties.

International Publication No. 2011/024812

The present invention provides a rubber material for a gasket and a gasket that can provide excellent vibration damping and vibration isolation properties as well as a good gasket function.

The rubber material for gaskets according to the present invention contains rubber and carbon black, and the rubber is a nitrile rubber containing 30% by mass or more of acrylonitrile, and has a 100% modulus value of 5.0 MPa according to JIS K6251:2017. In addition, the type A durometer hardness measured in accordance with JIS K6253-3:2012 is 90 or less.

In the rubber material for gaskets according to the present invention, it is preferable that the rubber content contained in the rubber material is 30% by mass or more and 65% by mass or less.

In the rubber material for gaskets according to the present invention, it is preferable that the carbon black has a primary particle diameter of 26 nm or more.

In the rubber material for gaskets according to the present invention, it is preferable that the material contains more than 35 parts by mass of carbon black per 100 parts by mass of the rubber.

The gasket according to the present invention includes a rubber layer containing the rubber material and a metal base material, and the rubber layer is provided on at least one surface of the metal base material.

According to the present invention, it is possible to provide a rubber material for a gasket and a gasket that can provide excellent vibration damping and vibration isolation properties as well as a good gasket function.

Embodiments of the present invention will be described in detail below. The rubber material for gaskets according to the present embodiment (hereinafter sometimes simply referred to as "rubber material") contains nitrile rubber containing 30% by mass or more of acrylonitrile as rubber, and carbon black as a reinforcing material. In addition, the physical properties of the rubber material include a 100% modulus value of 5.0 MPa or more in accordance with JIS K6251:2017, and a type A durometer hardness of 90 or less as measured in accordance with JIS K6253-3:2012. It is. Here, the "100% modulus value" represents the value obtained by dividing the tensile force when 100% elongation is applied to a test piece of a rubber material by the cross-sectional area of the test piece before the test. When the 100% modulus value of the rubber material is 5.0 MPa or more, the rubber material is given an appropriate elastic modulus, so even if compressive stress is applied to the gasket, the rubber material will not be released from the gasket. It becomes possible to suppress earworms. As a result, it is possible to obtain a rubber material that can satisfy the pressure resistance properties required of a gasket and can provide good gasket function. Further, since the type A durometer hardness of the rubber material is 90 or less, it becomes possible to reduce the dynamic spring constant of the rubber material, and the transmission of vibration from the vibration source is effectively suppressed. Furthermore, by using nitrile rubber containing 30% by mass or more of acrylonitrile as a raw material for the rubber material, it has excellent vibration damping properties and vibration isolation in the high-temperature region (region above room temperature), which is necessary for application as a housing gasket. Demonstrate your sexuality. As a result, a rubber material that can provide excellent vibration damping and vibration damping properties can be obtained as a gasket material.

In the rubber material according to this embodiment, the 100% modulus value according to JIS K6251:2017 is 5.0 MPa or more. This provides the rubber material with an appropriate elastic modulus and simultaneously satisfies the protrusion characteristics required for a gasket, resulting in a rubber material that can provide good gasket function. The 100% modulus value of the rubber material is preferably 5.0 MPa or more, and more preferably 8.0 MPa or more.

In the rubber material according to this embodiment, the Type A durometer hardness measured in accordance with JIS K6253-3:2012 is 90 (points) or less. This makes it possible to reduce the dynamic spring constant of the rubber material, and effectively suppresses the transmission of vibration from the vibration source. As a result, a rubber material that can impart excellent vibration damping and vibration isolation properties as a gasket material can be obtained. The Type A durometer hardness of the rubber material is preferably 90 (points) or less, and more preferably 85 (points) or less. In addition, the lower limit of the Type A durometer hardness of the rubber material is preferably 70 (points) or more from the viewpoint of the protrusion characteristics of the gasket.

(rubber component)
The rubber (rubber polymer) constituted as the main component of the rubber material is nitrile rubber containing 30% by mass or more of acrylonitrile. Nitrile rubber is a copolymer of butadiene and acrylonitrile and may be hydrogenated or non-hydrogenated. Examples of nitrile rubbers include nitrile rubbers containing 30% by mass or more of acrylonitrile, such as very high nitrile content (acrylonitrile content of 43% or more), high nitrile content (acrylonitrile content of 36% or more and less than 43%), and medium-high nitrile content. (acrylonitrile content of 31% or more and less than 36%) and medium nitrile content (acrylonitrile content of 25% or more and less than 31%). In particular, by using nitrile rubber containing 36% by mass or more of acrylonitrile, vibration damping properties and vibration isolation properties in high temperature ranges are improved, and a rubber material that can provide better vibration damping properties and vibration isolation properties is obtained. I can do it. The nitrile rubber constituted as a rubber component may be used alone or in combination of two or more.

Commercial products of such nitrile rubber include the trade name "Nipol (registered trademark) DN3350" (acrylic nitrile content 33%, manufactured by Zeon Corporation) and the trade name "NANCAR (registered trademark) 3345" (acrylonitrile content 33%: Product name: "N230S" (acrylic nitrile content: 35%: manufactured by JSR Corporation); Product name: "N220S" (acrylonitrile content: 41.5%: manufactured by JSR Corporation); Product name: "Nipol (registered trademark)" ) DN003'' (acrylonitrile content 50%: manufactured by Nippon Zeon Co., Ltd.).

The rubber content in the rubber material, i.e., the rubber polymer fraction, is preferably 30% by mass or more and 65% by mass or less, and more preferably 45% by mass or more and 62% by mass or less. The rubber content is set in the range of 30% by mass or more and 65% by mass or less depending on the type of carbon black described below so that the desired characteristics are imparted to the rubber material. In particular, by having a rubber content of 45% by mass or more and 62% by mass or less, a rubber material that can be imparted with better vibration damping and vibration isolation properties can be obtained.

(Carbon black)
The rubber material according to this embodiment contains carbon black, and preferably contains carbon black having a primary particle diameter of 26 nm or more. Examples of such carbon black include High Abrasion Furnace (HAF) carbon black (primary particle size: 28 to 36 nm) and Easy Processing Channel (EPC) carbon black (primary particle size: 30 to 36 nm). Hard carbon such as 35 nm); as well as conductive (XCF: e 55nm), General Purpose Furnace (GPF) carbon black (primary particle size: 49-60nm), High Modulus Furnace (HMF) carbon black (primary particle size: 46-73nm), Medium Reinforcement (SRF) : Semi-Reinforcing Furnace) carbon black (primary particle size: 70 to 96 nm), fine thermal decomposition (FT) carbon black (primary particle size: 180 to 200 nm), and medium thermal decomposition (MT) Examples include soft carbon such as carbon black (primary particle size: 250 to 350 nm). These carbon blacks may be used alone or in combination of two or more. Among these, soft carbon is preferable as carbon black, and among soft carbon, SRF carbon black and MT carbon black are more preferable. Commercial products of carbon black include, for example, MT carbon black such as the product name "THERMAX (registered trademark) N990 LSR" (manufactured by Can Carb Co., Ltd.), and the product name "HTC #S" (manufactured by Nippon Steel Carbon Co., Ltd.) and the product name Examples include SRF carbon black such as "Asahi #50HG" (manufactured by Asahi Carbon Co., Ltd.) and HAF carbon black such as the trade name "Show Black N330" (manufactured by Showa Cabot Co., Ltd.).

The blending amount of carbon black is set so that the rubber content (rubber polymer fraction) is 30% by mass or more and 65% by mass or less. The amount of carbon black to be blended is preferably more than 35 parts by mass, more preferably 50 parts by mass or more, per 100 parts by mass of rubber. Further, the amount of carbon black blended is preferably 250 parts by mass or less, more preferably 200 parts by mass or less, based on 100 parts by mass of rubber.

When the carbon black is MT carbon, the lower limit of the amount of carbon black to be blended is preferably 50 parts by mass or more, more preferably 70 parts by mass or more, and even more preferably 85 parts by mass or more, relative to 100 parts by mass of rubber, from the viewpoint of imparting an appropriate elastic modulus to the rubber material and improving the sticking-out characteristics when a compressive stress is applied. Also, the upper limit of the amount of carbon black to be blended is preferably 220 parts by mass or less, more preferably 200 parts by mass or less, and even more preferably 180 parts by mass or less, relative to 100 parts by mass of rubber, from the viewpoint of imparting an appropriate hardness to the rubber material and improving vibration damping and vibration prevention properties.

When the carbon black is SRF carbon, the lower limit of the amount of carbon black to be blended is preferably 40 parts by mass or more, and more preferably 50 parts by mass or more, per 100 parts by mass of rubber, from the viewpoint of imparting an appropriate elastic modulus to the rubber material and improving the sticking-out characteristics when a compressive stress is applied. Also, the upper limit of the amount of carbon black to be blended is preferably 120 parts by mass or less, and more preferably 110 parts by mass or less, per 100 parts by mass of rubber, from the viewpoint of imparting an appropriate hardness to the rubber material and improving vibration damping and vibration isolation.

The rubber material used to form the rubber layer of the gasket preferably contains a vulcanizing agent and a vulcanization accelerator in order to provide the rubber material with a crosslinked structure. Examples of the vulcanizing agent include commercially available colloidal sulfur A (manufactured by Tsurumi Kagaku Kogyo Co., Ltd.) and trade name "Varnock (registered trademark) R" (4,4'-dithiodimorpholine: made by Ouchi Shinko Kagaku Kogyo Co., Ltd.). Examples include items. These vulcanizing agents may be used alone or in combination of two or more. The blending amount of the vulcanizing agent is preferably 0.1 parts by mass or more and 10 parts by mass or less, for example, based on 100 parts by mass of rubber.

As the vulcanization accelerator, various sulfur-containing vulcanization accelerators such as guanidine-based, aldehyde-amine-based, aldehyde-ammonia-based, thiazole-based, sulfenamide-based, thiourea-based, thiuram-based, dithiocarbamate-based, and xanthate-based are used. Among these, tetramethylthiuram disulfide, tetrabenzylthiuram disulfide, and N-cyclohexyl-2-benzothiazylsulfenamide are preferred as the sulfur-containing vulcanization accelerator. These vulcanization accelerators may be used alone or in combination of two or more. Examples of the vulcanization accelerator include commercially available products such as "Noccela (registered trademark) TBZTD" (tetrabenzylthiuram disulfide: manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) and "Noccela (registered trademark) CZ-P" (N-cyclohexyl-2-benzothiazylsulfenamide: manufactured by Ouchi Shinko Chemical Industry Co., Ltd.). The amount of vulcanization accelerator mixed is preferably, for example, 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of rubber.

The rubber material may also contain various auxiliaries commonly used in the rubber industry, such as plasticizers, acid acceptors such as zinc oxide, processing aids such as stearic acid, antioxidants, and waxes, as necessary.

Examples of the plasticizer include commercially available products such as the trade name "ADEKASIZER (registered trademark) RS107" (adipic acid ether ester type: manufactured by ADEKA). As the acid acceptor, for example, a commercially available product such as zinc oxide (manufactured by Seido Kagaku Kogyo Co., Ltd.) may be used. As the anti-aging agent, for example, a commercially available product such as the product name "Nocrac (registered trademark) 810-NA" (2,2,4-trimethyl-1,2-dihydroquinoline polymer: manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) can be mentioned. Examples of processing aids include stearic acid, for example, commercially available products such as the trade name "DTST" (manufactured by Miyoshi Yushi Co., Ltd.). Examples of the wax include commercially available products such as "Santite (registered trademark) R" (normal paraffin wax, manufactured by Seiko Kagaku Co., Ltd.). Each of these auxiliary agents may be used alone or in combination of two or more. The blending amount of each auxiliary agent is preferably, for example, 0.5 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of rubber.

The rubber material may also contain fillers such as calcium carbonate and silica, if necessary. As calcium carbonate, various types of calcium carbonate, such as heavy calcium carbonate and synthetic calcium carbonate, can be used. As calcium carbonate, commercially available products such as "Whiten (registered trademark) SB-Red" (heavy calcium carbonate, manufactured by Bihoku Funka Kogyo Co., Ltd.) can be used.

Examples of silica that can be used include amorphous silica, such as dry silica produced by the thermal decomposition of halogenated silicic acid or organic silicon compounds, or by the air oxidation of silicon oxide (SiO) vaporized by heating and reducing silica sand, and wet silica produced by the thermal decomposition of sodium silicate. Commercially available silica products include, for example, the product name "Nipsil (registered trademark) E-74P" (manufactured by Tosoh Silica Corporation). Each of these fillers may be used alone or in combination of two or more. The amount of each filler to be mixed is preferably, for example, 2 to 200 parts by mass per 100 parts by mass of rubber.

<Gasket>
The gasket according to this embodiment includes a rubber layer containing the above-described rubber material and a metal base material, and the rubber layer is provided on at least one surface of the metal base material. The rubber layer may be provided on one side or both sides of the metal base material. Such a gasket has excellent vibration-damping and vibration-proofing properties even in the high-temperature region required for a gasket for a housing, and therefore can be used, for example, in automobile housing parts such as compressors, inverters, and motors. In particular, since it is possible to reduce noise and vibration such as motor startup noise, when the gasket is applied to automobile parts, the reduction in vibration makes the interior of the automobile quieter, and it is expected that the ride comfort will be improved. Furthermore, even in applications other than automobiles, it is possible to prevent noise and vibrations generated inside machines, equipment, etc. from leaking to the outside. Furthermore, it is possible to realize a gasket with good gasket functions such as tampering properties.

(rubber layer)
The rubber layer is formed, for example, by applying the above-mentioned vulcanized rubber material onto a metal substrate. The thickness of the rubber layer is appropriately set depending on the use of the gasket, and is preferably 20 μm or more and 200 μm or less.

(metal base material)
Examples of the material of the metal base material include iron, stainless steel, aluminum, magnesium, galvanized steel, and copper. As the iron, for example, a cold rolled steel plate (SPCC), a high tensile strength steel plate, a mild steel plate, etc. are used. Further, as the stainless steel, for example, a ferritic, martensitic, or austenitic stainless steel plate can be used. Specific examples of stainless steel include, for example, SUS304, SUS301, SUS301H, and SUS430. As the aluminum, an aluminum plate, an aluminum die-cast plate, etc. are used.

The metal substrate is preferably subjected to a surface treatment. There is no particular restriction on the surface treatment, and any known surface treatment can be used. When using iron and stainless steel such as cold-rolled steel sheet, high-tensile steel sheet, and stainless steel sheet as the metal substrate, the surface treatment is preferably a chemical conversion treatment method using a chemical conversion treatment agent such as zinc phosphate treatment or iron phosphate treatment, or a plating method such as electrolytic zinc plating or hot-dip galvanization. Examples of chemical conversion treatment agents for metal substrates include organic chemical conversion treatment agents containing silicone compounds, titanium compounds, zirconium compounds, etc. In addition, chromium-free chemical conversion treatment agents that do not substantially contain chromium are preferable from the viewpoint of preventing environmental pollution.

The thickness of the metal base material is appropriately set depending on the use of the gasket, and is preferably 100 μm or more and 2000 μm or less.

(glue)
The rubber layer and the metal base material may be adhered to each other using an adhesive. As the adhesive, commercially available adhesives such as phenol resin, epoxy resin, polyurethane resin, and silane are used. These adhesives can be appropriately selected depending on the use of the gasket. By using an adhesive, the adhesiveness between the metal base material and the rubber layer is improved.

As the phenol resin, for example, a novolac type phenol resin and a resol type phenol resin are used. The novolak type phenolic resin and the resol type phenolic resin may be used alone or in combination of two or more types. Further, as the adhesive, one containing two types of phenolic resins, a novolak type phenolic resin and a resol type phenolic resin, and unvulcanized nitrile rubber may be used.

Examples of the epoxy resin include bisphenol A type, cresol novolac type, biphenyl type, and brominated epoxy resin. These epoxy resins may be used alone or in combination of two or more. Among these epoxy resins, bisphenol A epoxy resins and cresol novolac epoxy resins are preferred from the viewpoint of easy commercial availability and excellent heat resistance.

The various adhesives described above are used as a solution dissolved in an organic solvent. Examples of the organic solvent include ketones such as methyl ethyl ketone and methyl isobutyl ketone, and aromatic hydrocarbons such as toluene and xylene. These organic solvents may be used alone or in combination of two or more.

<Rubber material and gasket manufacturing method>
The rubber material and gasket according to this embodiment can be manufactured, for example, by the following method. The rubber material is a mixture of specified nitrile rubber, carbon black, a vulcanizing agent, a vulcanization accelerator, and various auxiliary agents and fillers as necessary, and the mixture is processed using an intermix, kneader, Banbury mixer, etc. Manufactured by kneading with a kneader or open rolls. Gaskets are manufactured by applying the obtained rubber material via an adhesive layer onto a metal base material whose surface has been arbitrarily treated, and then vulcanizing the rubber material under predetermined heating conditions to form a rubber layer. Ru. The rubber material is preferably applied so that the thickness of the rubber layer after application is 20 μm or more and 200 μm or less. Further, in manufacturing the gasket, a resin-based coating agent, a graphite-based coating agent, or the like may be applied onto the rubber layer.

The method for applying the rubber material onto the metal base material is not particularly limited as long as the rubber material can be applied onto the metal base material. Examples of the application method include a spray method, a dipping method, a roll coating method, and a dispenser method.

When manufacturing the rubber material and applying it onto a metal substrate, an organic solvent may be added to the rubber material to adjust the viscosity, if necessary. The organic solvent is not particularly limited as long as it can adjust the viscosity of the rubber material to a desired viscosity. Examples of the organic solvent include methyl ethyl ketone, toluene, and ethyl acetate. These organic solvents may be used alone or in combination of two or more.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and includes all aspects included in the concept of the present invention and the scope of the claims. It can be modified to .

Hereinafter, the present invention will be explained in more detail based on Examples. Note that the present invention is not limited to the following examples.

(Example 1A) 100 parts by mass of nitrile rubber A (trade name "NANCAR (registered trademark) 3345", manufactured by Ssangyong Sangyo Co., Ltd.), carbon black A (MT carbon black: trade name "THERMAX (registered trademark) N990 LSR"), 90 parts by mass of zinc oxide (manufactured by Seido Kagaku Kogyo Co., Ltd.), 1 part by mass of stearic acid (trade name "DTST", manufactured by Miyoshi Oil Co., Ltd.), anti-aging agent (2,2,4 -Trimethyl-1,2-dihydroquinoline polymer: 2 parts by mass of product name "Nocrac (registered trademark) 810-NA", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., vulcanizing agent A (colloidal sulfur A, Tsurumi Chemical Co., Ltd.) (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) 1.5 parts by mass, 1 part by mass of vulcanizing agent B (4,4'-dithiodimorpholine: trade name "Varnock (registered trademark) R", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.), vulcanization accelerator A (tetrabenzylthiuram disulfide: trade name "Noxela (registered trademark) TBZTD", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.) 5 parts by mass, and vulcanization accelerator B (N-cyclohexyl-2-benzothiazyl sulfenamide: product) A rubber material was prepared by kneading 4 parts by mass of Noxela (registered trademark) CZ-P, manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. using a kneader and an open roll.

<Measurement of physical properties of rubber materials>
The obtained rubber material was pressurized and vulcanized at 170° C. for 8 minutes to prepare a sample of a 2 mm thick rubber piece (4 mm width x 20 mm length). The hardness of the obtained rubber piece was measured using a type A durometer in accordance with JIS K6253-3:2012, and the 100% modulus value, tensile strength, and elongation were measured in accordance with JIS K6251:2017. The measurement results are shown in Table 1 below.

A gasket was produced using the obtained rubber material, and various performances of the produced gasket were evaluated.

<Vibration damping/vibration isolation>
(1) Preparation of sample for loss factor measurement The surface of a cold rolled steel plate with a thickness of 400 μm was treated with zinc phosphate. Thereafter, methyl ethyl ketone (MEK) in which a phenolic resin (trade name "Sixon 715" manufactured by Rohm & Haas Japan) was dissolved was applied onto the surface-treated cold-rolled steel plate, and then dried. The above rubber material was then dissolved in MEK. After this, MEK in which the rubber material has been dissolved is applied onto the cold rolled steel sheet after the MEK solution containing the phenol resin has been applied, and then the rubber material is vulcanized for 3 minutes in an oven at 200°C to perform cold rolling. A rubber layer with a thickness of 120 μm was formed on a steel plate (metal base material). As a result, a gasket having a rubber layer on a metal base material and having a width of 17 mm and a length of 250 mm was produced. A sample for loss factor measurement was prepared by attaching the gasket thus obtained to a SUS301 plate having a thickness of 250 μm, a width of 17 mm, and a length of 250 mm via a cyanoacrylate adhesive. In addition, through preliminary experiments, it was confirmed that the type of adhesive does not affect the value of the loss coefficient as long as the gasket can be attached to the SUS301 plate.

(2) Evaluation of vibration damping/vibration damping properties The obtained sample was measured using Rion AS14PA5 (cantilever type) using the half-width method in accordance with JIS K7391:2008 at a measurement temperature of 23±2°C. The loss coefficient at room temperature was measured using the second-order resonance frequency within the measurement range of 0 to 1 kHz. If the loss coefficient is 0.03 or more, it is judged that the vibration damping property and vibration isolation property are excellent and is evaluated as "○", and if the loss coefficient is less than 0.03, the vibration damping property and vibration isolation property are judged to be excellent. I judged it to be inferior in gender and rated it "x". The evaluation results are shown in Table 1 below.

<Gasket function>
(1) Preparation of a sample for compression test evaluation A phenolic resin (trade name "Sixon 715" manufactured by Rohm and Haas Co.) diluted with an organic solvent of MEK and methanol was applied to a cold-rolled steel plate having a thickness of 400 μm and surface-treated with zinc phosphate, and dried at room temperature. Next, the obtained rubber material was dissolved in an organic solvent and applied to a cold-rolled steel plate coated with a phenolic resin so that the rubber layer had a thickness of 120 μm, and then vulcanized in an oven at 200 ° C. for 3 minutes to prepare a sample for compression test evaluation of a gasket. Here, an anti-adhesion layer may be applied as necessary. The compression test evaluation sample prepared was evaluated for the protrusion characteristics of the rubber layer as a gasket function by the following evaluation method.

(2) Evaluation of Hamidashi characteristics A donut-shaped convex metal fitting was placed on the rubber layer of the sample for evaluation of the compression test of the casket for 5 minutes at 100°C, under condition A of a pressure of 150 MPa, and for 5 minutes at 150°C. After pressing under condition B at a pressure of 150 MPa, the state of the rubber layer was evaluated based on the following criteria. In the following evaluation criteria, if the evaluation for condition A and condition B is 3 points or more, it is judged that the rubber layer has been suppressed and evaluated as "○", and if either evaluation is less than 3 points, it is evaluated as "○". If so, it was determined that the rubber layer was insufficiently inhibited from tingling, and was rated as "x". The evaluation results are shown in Table 1 below.
5 points: No metal is exposed and almost no rubber flow is observed.
4 points: There is no exposed metal and a small amount of rubber flows.
3 points: Although a considerable amount of rubber flow occurred, metal was not exposed.
2 points: Rubber flow is large, but metal exposure is small.
1 point: Both rubber flow and metal exposure are large.

(Example 2A)
A rubber material and a gasket were produced in the same manner as in Example 1A, except that the amount of carbon black A was 151 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 1 below.

(Example 3A)
Except that the amount of carbon black A was 181 parts by mass, and 10 parts by mass of a plasticizer (adipic acid ether ester type: trade name "ADEKASIZER (registered trademark) RS107", manufactured by ADEKA) were used. A rubber material and a gasket were produced in the same manner as in Example 1A, and the above measurements and evaluations were performed. The results are shown in Table 1 below.

(Example 4A)
A rubber material and a gasket were prepared in the same manner as in Example 1A, except that 65 parts by mass of carbon black B (SRF carbon black: trade name "HTC #S", manufactured by Nippon Steel Carbon Co., Ltd.) was used in place of carbon black A. was prepared and the above measurements and evaluations were performed. The results are shown in Table 1 below.

(Example 5A)
A rubber material and a gasket were produced in the same manner as in Example 4A, except that the amount of carbon black B was 104 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 1 below.

(Example 6A)
A rubber material and a gasket were prepared in the same manner as in Example 1A, except that 58 parts by mass of carbon black C (SRF carbon black: product name "Asahi #50HG", manufactured by Asahi Carbon Co., Ltd.) was used instead of carbon black A, and the above measurements and evaluations were carried out. The results are shown in Table 1 below.

Example 7A
A rubber material and a gasket were prepared in the same manner as in Example 1A, except that 46 parts by mass of carbon black D (HAF carbon black: product name "Show Black N330", manufactured by Showa Cabot Corporation) was used instead of carbon black A, and the above measurements and evaluations were carried out. The results are shown in Table 1 below.

(Comparative example 1A)
A rubber material and a gasket were produced in the same manner as in Example 1A, except that the amount of carbon black A was 45 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 2 below.

(Comparative Example 2A)
A rubber material and a gasket were produced in the same manner as in Example 4A, except that the blending amount of carbon black B was 31 parts by mass, and the above measurements and evaluations were carried out. The results are shown in Table 2 below.

(Comparative example 3A)
A rubber material and a gasket were produced in the same manner as in Example 6A, except that the amount of carbon black C was 30 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 2 below.

(Comparative Example 4A)
A rubber material and a gasket were produced in the same manner as in Example 6A, except that the blending amount of carbon black C was 125 parts by mass, and the above measurements and evaluations were carried out. The results are shown in Table 2 below.

(Comparative Example 5A)
A rubber material and a gasket were produced in the same manner as in Example 1A, except that the blending amount of carbon black A was 230 parts by mass, and the above measurements and evaluations were carried out. The results are shown in Table 2 below.

(Example 1B)
100 parts by mass of nitrile rubber A (trade name "NANCAR (registered trademark) 3345", manufactured by Ssangyong Sangyo Co., Ltd.), carbon black A (MT carbon black: trade name "THERMAX (registered trademark) N990 LSR", manufactured by Can Carb Corporation) 90 parts by mass, zinc oxide (manufactured by Seido Kagaku Kogyo Co., Ltd.) 5 parts by mass, stearic acid (trade name "DTST", manufactured by Miyoshi Oil Co., Ltd.) 1 part by mass, anti-aging agent (2,2,4-trimethyl-1, 2-dihydroquinoline polymer: 2 parts by mass of trade name "Nocrac (registered trademark) 810-NA", manufactured by Ouchi Shinko Chemical Industry Co., Ltd., 1.5 parts of vulcanizing agent A (colloidal sulfur A, manufactured by Tsurumi Chemical Industry Co., Ltd.) Parts by mass, 1 part by mass of vulcanizing agent B (4,4'-dithiodimorpholine: trade name "Varnock (registered trademark) R", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.), vulcanization accelerator A (tetrabenzylthiuram disulfide) 5 parts by mass of vulcanization accelerator B (N-cyclohexyl-2-benzothiazylsulfenamide): trade name "Noxela (registered trademark) TBZTD", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.), and vulcanization accelerator B (N-cyclohexyl-2-benzothiazylsulfenamide): A rubber material was prepared by kneading 4 parts by mass of CZ-P (trademark) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd. using a kneader and an open roll.

<Measurement of physical properties of rubber materials>
A rubber piece sample was prepared in the same manner as in Example 1A above. The hardness of the obtained rubber piece was measured using a type A durometer in accordance with JIS K6253-3:2012, and the 100% modulus value, tensile strength, and elongation were measured in accordance with JIS K6251:2017. The measurement results are shown in Table 3 below.

A gasket was produced using the obtained rubber material, and various performances of the produced gasket were evaluated.

<Vibration damping and vibration prevention>
(1) Preparation of loss factor measurement sample A loss factor measurement sample was prepared in the same manner as in Example 1A. In addition, a preliminary experiment confirmed that the type of adhesive does not affect the loss factor value as long as the gasket can be attached to the SUS301 plate.

(2) Evaluation of vibration damping/vibration damping properties The obtained sample was measured using Rion AS14PA5 (cantilever type) using the half-width method in accordance with JIS K7391:2008 at a measurement temperature of 23±2°C. The loss coefficient at room temperature was measured using the second-order resonance frequency within the measurement range of 0 to 1 kHz. In addition, the loss coefficient at high temperatures was also measured at measurement temperatures of 50° C. and 70° C. and at a secondary resonance frequency within the measurement range of 0 to 20 kHz. If the loss coefficients at 50°C and 70°C are both 0.015 or more, it is judged that the vibration damping and vibration isolation properties are excellent and evaluated as "○", and one of the loss coefficients is 0. If it was less than .015, it was judged that the vibration damping properties and vibration isolation properties were poor, and the evaluation was rated as "x". The evaluation results are shown in Table 3 below.

<Gasket function>
A gasket compression test evaluation sample was prepared in the same manner as in Example 1A. An anti-adhesive layer may be applied if necessary. The compression test evaluation sample was evaluated for the protrusion characteristics of the rubber layer as a gasket function using the same evaluation method as in Example 1A. The evaluation results are shown in Table 3 below.

(Example 2B)
A rubber material and a gasket were prepared in the same manner as in Example 1B, except that 100 parts by mass of nitrile rubber B (trade name "N230S", manufactured by JSR Corporation) was used in place of nitrile rubber A, and the above measurements were carried out. and evaluated. The results are shown in Table 3 below.

(Example 3B)
A rubber material and a gasket were prepared in the same manner as in Example 1B, except that 100 parts by mass of nitrile rubber C (trade name "N220S", manufactured by JSR Corporation) was used in place of nitrile rubber A, and the above measurements were carried out. and evaluated. The results are shown in Table 3 below.

(Example 4B)
Except that 100 parts by mass of nitrile rubber D (trade name "Nipol (registered trademark) DN003", manufactured by Nippon Zeon Co., Ltd.) was used in place of nitrile rubber A, and the amount of carbon black A was 60 parts by mass. A rubber material and a gasket were produced in the same manner as in Example 1B, and the above measurements and evaluations were performed. The results are shown in Table 3 below.

(Example 5B)
A rubber material and a gasket were produced in the same manner as in Example 1B, except that the amount of carbon black A was 151 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 3 below.

(Example 6B)
A rubber material and a gasket were prepared in the same manner as in Example 1B, except that 65 parts by mass of carbon black B (SRF carbon black: trade name "HTC #S", manufactured by Nippon Steel Carbon Co., Ltd.) was used in place of carbon black A. was prepared and the above measurements and evaluations were performed. The results are shown in Table 3 below.

(Example 7B)
A rubber material and a gasket were produced in the same manner as in Example 6B, except that the amount of carbon black B was 104 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 3 below.

(Example 8B)
The rubber material and gasket were prepared in the same manner as in Example 1B, except that 58 parts by mass of carbon black C (SRF carbon black: trade name "Asahi #50HG", manufactured by Asahi Carbon Co., Ltd.) was used in place of carbon black A. It was manufactured and the above measurements and evaluations were performed. The results are shown in Table 3 below.

Example 9B
A rubber material and a gasket were produced in the same manner as in Example 8B, except that the blending amount of carbon black C was 90 parts by mass, and the above measurements and evaluations were carried out. The results are shown in Table 3 below.

(Comparative example 1B)
A rubber material and a gasket were prepared in the same manner as in Example 1B, except that 100 parts by mass of nitrile rubber E (trade name "N240S", manufactured by JSR Corporation) was used in place of nitrile rubber A, and the above measurements were carried out. and evaluated. The results are shown in Table 4 below.

(Comparative Example 2B)
A rubber material and a gasket were produced in the same manner as in Example 1B, except that the blending amount of carbon black A was 45 parts by mass, and the above measurements and evaluations were carried out. The results are shown in Table 4 below.

(Comparative Example 3B)
A rubber material and a gasket were produced in the same manner as in Example 6B, except that the blending amount of carbon black B was 31 parts by mass, and the above measurements and evaluations were carried out. The results are shown in Table 4 below.

(Comparative example 4B)
A rubber material and a gasket were produced in the same manner as in Example 8B, except that the amount of carbon black C was 30 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 4 below.

(Comparative Example 5B)
A rubber material and a gasket were produced in the same manner as in Example 8B, except that the amount of carbon black C was 125 parts by mass, and the above measurements and evaluations were performed. The results are shown in Table 4 below.

The ingredients for each component in Tables 1 to 4 above are as follows.
Nitrile rubber A: medium-high nitrile (acrylonitrile content 33%, product name "NANCAR (registered trademark) 3345", manufactured by Ssangyong Sangyo Co., Ltd.)
Nitrile rubber B: medium-high nitrile (acrylonitrile content 35%, product name "N230S", manufactured by JSR)
Nitrile rubber C: High nitrile (acrylonitrile content 41.5%, trade name "N230S", manufactured by JSR)
Nitrile rubber D: Extremely high nitrile (acrylonitrile content 50%, trade name "Nipol (registered trademark) DN003", manufactured by Nippon Zeon Co., Ltd.)
Nitrile rubber E: medium nitrile (acrylonitrile content 26%, product name "N240S", manufactured by JSR Corporation)
Carbon black A: MT carbon black (product name "THERMAX (registered trademark) N990 LSR" manufactured by Can Carb)
Carbon black B: SRF carbon black (product name "HTC #S", manufactured by Nippon Steel Carbon Co., Ltd.)
Carbon black C: SRF carbon black (product name "Asahi #50HG", manufactured by Asahi Carbon Co., Ltd.)
Carbon black D: HAF carbon black (product name "Show Black N330", manufactured by Showa Cabot)
Plasticizer: Adipic acid ether ester type (trade name: ADEKASIZER (registered trademark) RS107, manufactured by ADEKA)
Zinc oxide (manufactured by Seido Kagaku Kogyo Co., Ltd.)
Stearic acid: Product name “DTST” (manufactured by Miyoshi Oil Co., Ltd.)
Anti-aging agent: 2,2,4-trimethyl-1,2-dihydroquinoline polymer (trade name "Nocrac (registered trademark) 810-NA", manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
Vulcanizing agent A: Colloidal sulfur A (manufactured by Tsurumi Chemical Industry Co., Ltd.)
Vulcanizing agent B: 4,4'-dithiodimorpholine (trade name "Varnock (registered trademark) R", manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
Vulcanization accelerator A: Tetrabenzylthiuram disulfide (trade name: "Noxela (registered trademark) TBZTD", manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)
Vulcanization accelerator B: N-cyclohexyl-2-benzothiazyl sulfenamide (trade name "Noxela (registered trademark) CZ-P", manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.)
Incidentally, the blending amounts of each of the above components in Tables 1 to 4 represent "parts by mass."

As shown in Table 1, by providing a gasket with a rubber layer containing a rubber material with a 100% modulus value of 5.0 MPa or more and a type A durometer hardness of 90 or less, a gasket with excellent vibration damping and vibration prevention properties and good gasket function was obtained (Examples 1A to 7A). In particular, when the rubber content (rubber polymer fraction) was 45% by mass or more and 62% by mass or less, the vibration damping and vibration prevention properties were more excellent (Examples 1A, 4A, 6A, and 7A).

On the other hand, as shown in Table 2, when the 100% modulus value of the rubber material was less than 5.0 MPa, the overhanging property was rated less than 3, and sufficient gasket function was not achieved (Comparative Examples 1A to 3A). Also, when the Type A durometer hardness of the rubber material exceeded 90, the loss factor was less than 0.03 in all cases, and vibration damping and vibration prevention properties were poor (Comparative Examples 4A to 5A).

As shown in Table 3, when nitrile rubber containing 30% or more by mass of acrylonitrile was used as the rubber material, the 100% modulus value of the rubber material was 5.0 MPa or more, and the type A durometer hardness was 90 or less, the loss factor was high even at high temperatures, and the gasket had excellent vibration damping and vibration prevention properties and good gasket function (Examples 1B to 9B). In particular, when nitrile rubber containing 36% or more by mass of acrylonitrile was used, a higher loss factor was shown and the vibration damping and vibration prevention properties were excellent (Examples 3B and 4B). Furthermore, when the rubber content (rubber polymer fraction) was 45% or more by mass and 62% or less by mass, the loss factor at room temperature was high and the vibration damping and vibration prevention properties were excellent, as in Table 1 (Examples 1B to 4B, 6B, and 8B to 9B).

On the other hand, as shown in Table 4, when using nitrile rubber with an acrylonitrile content of less than 30% by mass, the loss coefficient at high temperatures is less than 0.015, resulting in poor vibration damping and damping properties. (Comparative Example 1B). Furthermore, even if nitrile rubber containing 30% by mass or more of acrylonitrile is used, if the 100% modulus value of the rubber material is less than 5.0 MPa, the evaluation of the hamidashi property will be less than 3, and sufficient gasket function will be achieved. It was not possible (Comparative Examples 2B to 4B). Further, when the type A durometer hardness of the rubber material exceeded 90, the loss coefficient at high temperature was less than 0.015, and the damping and vibration damping properties were poor (Comparative Example 5B).

From the above results, in a rubber material containing nitrile rubber containing 30% by mass or more of acrylonitrile and carbon black, the 100% modulus value of the rubber material is 5.0 MPa or more, and the type A durometer hardness is 90. By having the following properties, it is possible to provide a rubber material suitable for producing a gasket that has excellent vibration damping properties and vibration isolation properties, and also has good gasket functions such as hamstring properties. A gasket equipped with a rubber layer containing such a rubber material can exhibit excellent vibration damping and vibration isolation properties, and is particularly suitable for use as a gasket for the housing of compressors, inverters, motors, etc. .

Claims (5)

Contains rubber and carbon black,
The rubber is nitrile rubber containing 30% by mass or more of acrylonitrile,
A gasket characterized in that the 100% modulus value according to JIS K6251:2017 is 5.0 MPa or more, and the type A durometer hardness measured according to JIS K6253-3:2012 is 90 or less. Rubber material for. The rubber material according to claim 1, wherein the rubber content contained in the rubber material is 30% by mass or more and 65% by mass or less. The rubber material according to claim 1 or 2, wherein the carbon black has a primary particle size of 26 nm or more. The rubber material according to any one of claims 1 to 3, containing more than 35 parts by mass of carbon black based on 100 parts by mass of the rubber. A rubber layer containing the rubber material according to any one of claims 1 to 4, and a metal base material,
A gasket, wherein the rubber layer is provided on at least one surface of the metal base material.