Reinforced elastomer sheet laminate with suppressed thermal expansion

Abstract

To provide a reinforced elastomer sheet with thermal expansion in at least one of surface directions being suppressed under a high-temperature environment, and to provide a method of producing the same.SOLUTION: Provided is a reinforced elastomer sheet 10 in which one or more layered reinforcement materials 1 and one or more elastomer layers 2A, 2B are laminated, the reinforced elastomer sheet 10 having a laminate structure in which the first elastomer layer 2A is laminated on one major surface 1a of the first layered reinforcement material 1, a coefficient of linear expansion of a material constituting the layered reinforcement material being smaller than a coefficient of linear expansion of elastomer constituting the elastomer layers.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a reinforced elastomer sheet, a method for producing the same, and a reinforced elastomer sheet laminate. [Background technology]

[0002] Conventionally, methods for producing a composite silicone rubber sheet in which a synthetic fiber fabric, an inorganic fiber fabric, or a resin film is laminated on one surface of a silicone rubber sheet have been disclosed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-256068 A Summary of the Invention [Problem to be solved by the invention]

[0004] When an elastomer sheet such as silicone rubber is used in a high-temperature environment, thermal expansion occurs in the surface direction and thickness direction of the sheet, which may cause the installation to become unstable. If the sheet expands in the surface direction, the edge of the sheet will protrude from the specified position and shift in the surface direction or float up, and if the sheet expands in the thickness direction, it will push up objects facing the sheet or cause unnecessary contact. For this reason, an elastomer sheet that can maintain a stable size even in a high-temperature environment is required. In the composite silicone rubber sheet disclosed in Patent Document 1, the mechanical strength is improved, but suppression of thermal expansion when used in a high-temperature environment is not considered.

[0005] The present invention provides a reinforced elastomer sheet in which thermal expansion in at least one of the planar directions in a high-temperature environment is suppressed, a method for producing the same, and a reinforced elastomer sheet laminate. [Means for solving the problem]

[0006] [1] A reinforced elastomer sheet having one or more layered reinforcing materials and one or more elastomer layers laminated thereto, the reinforced elastomer sheet having a laminate structure in which a first elastomer layer is laminated on one main surface of a first layered reinforcing material, and the linear expansion coefficient of the material constituting the layered reinforcing materials is smaller than the linear expansion coefficient of the elastomer constituting the elastomer layer. [2] A reinforced elastomer sheet having an elastomer sheet as a main body, the main body including a plurality of layered reinforcing materials, the plurality of layered reinforcing materials extending in any direction approximately parallel to each other along one main surface of the elastomer sheet, each of the plurality of layered reinforcing materials extending from one main surface to the other main surface, and the linear expansion coefficient of the material constituting the layered reinforcing materials being smaller than the linear expansion coefficient of the elastomer constituting the elastomer sheet. [3] A reinforced elastomer sheet comprising an elastomer and a plurality of layered reinforcing materials, the reinforced elastomer sheet comprising a plurality of strip-shaped elastomer portions arranged in a planar direction, and a plurality of adhesive portions interposed between each of the elastomer portions and adhering them to each other, the adhesive portions having an adhesive material that adheres to the elastomer portions, and layered reinforcing materials that are in contact with the adhesive material, extend in the thickness direction of the reinforced elastomer sheet, and extend in the length direction of the strip-shaped elastomer portions, the linear expansion coefficient of a material constituting the layered reinforcing materials being smaller than the linear expansion coefficient of the elastomer. [4] The reinforced elastomer sheet according to any one of [1] to [3], wherein the layered reinforcing material is a nonwoven fabric. [5] A reinforced elastomer sheet laminate comprising a plurality of sheets arbitrarily selected from the reinforced elastomer sheets according to any one of [2] to [4] laminated together with their principal surfaces facing each other. [6] The reinforced elastomer sheet laminate according to [5], wherein, when viewed in the lamination direction of the reinforced elastomer sheet laminate, the crossing angle between the extension direction of one arbitrarily selected layer reinforcing material in the first reinforced elastomer sheet and the extension direction of one arbitrarily selected layer reinforcing material in the second reinforced elastomer sheet is 10 to 80°. [7] A method for producing a reinforced elastomer sheet, comprising: a step of obtaining a block laminate in which a plurality of elastomer layers are stacked with their principal surfaces facing each other and an adhesive and a layered reinforcement material interposed between the principal surfaces; and a step of cutting the block laminate along the stacking direction of the block laminate in a direction that cuts each layered reinforcement material within the block laminate, thereby obtaining a reinforced elastomer sheet, wherein the linear expansion coefficient of the material constituting the layered reinforcement material is smaller than the linear expansion coefficient of the elastomer constituting the elastomer layer. Effect of the Invention

[0007] In the reinforced elastomer sheet of the present invention, thermal expansion in at least one of the planar directions is suppressed, and therefore it is suitable for use in high-temperature environments of, for example, about 80 to 150°C. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view of an example of a reinforced elastomer sheet according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a top view of one major surface of reinforced elastomeric sheet 20, an example of the second embodiment of the present invention. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line SS in FIG. 2. [Figure 4] FIG. 1 is a perspective view of a block laminate 28 obtained by stacking eight elastomer layers 24 with adhesive 23 and layered reinforcing material 21 interposed between each pair of elastomer layers 24. [Diagram 5] FIG. 5 is a perspective view of a reinforced elastomer sheet 20 obtained by thinly cutting the block laminate 28 of FIG. 4 along a cut surface in the XY direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In this specification, the "thickness" and "width" of a member are the average values ​​measured for thickness or width at five or more randomly selected locations using a magnifying observation means such as a measuring microscope. The linear expansion coefficient of the material or member of the present invention is the average linear expansion coefficient measured in the temperature range of 25 to 150°C (representative temperature: 87.5°C) using a known thermomechanical analyzer in accordance with JIS K 7197-1991 "Test method for linear expansion coefficient by thermomechanical analysis of plastics." The tensile modulus of elasticity of the material or member of the present invention is a value measured in accordance with the JIS K 7161 standard series. When a nonwoven fabric is used as the material of the present invention, its air permeability, thickness (method A: 0.5 kPa pressure), tensile strength (standard time), elongation (standard time), and basis weight (mass per unit area) are measured in accordance with JIS L 1913:2010 "General nonwoven fabric testing methods."

[0010] <Reinforced elastomer sheet> <First aspect> The first aspect of the present invention is a reinforced elastomer sheet in which one or more layered reinforcing materials and one or more elastomer layers are laminated. As illustrated in FIG. 1, the reinforced elastomer sheet 10 has a laminated structure in which a first elastomer layer 2A is laminated on one main surface 1a of a first layered reinforcing material 1, and a second elastomer layer 2B is laminated on the other main surface 1b of the first layered reinforcing material 1. Here, the main surfaces of the layered reinforcing material 1 refer to each of the two surfaces with the largest area. Another adhesive layer (not shown) may be interposed between the layered reinforcing material 1 and each of the elastomer layers 2A and 2B. The other adhesive layer is preferably thinner than each of the elastomer layers. The other adhesive layer may be impregnated into the inside of the layered reinforcing material 1. Suitable elastomer materials and adhesives include those exemplified in the description of the manufacturing method described later.

[0011] The laminated structure of the reinforced elastomer sheet 10 is not limited to the above example, and may be a two-layer structure excluding the second elastomer layer 2B. In this two-layer structure, the layered reinforcing material 1 is exposed on the back side. In addition, in a three-layer structure similar to the reinforced elastomer sheet 10, the relationship between the layered reinforcing material and the elastomer layer may be reversed, and a three-layer structure may be formed in which a layered reinforcing material is provided on one main surface of the elastomer layer and the other main surface of the elastomer layer. In addition, the laminated structure is not limited to the two- or three-layer structure described here, and any number of layered reinforcing materials and elastomer layers may be laminated. Suitable layered reinforcing materials include those exemplified in the description of the manufacturing method described below.

[0012] In the reinforced elastomer sheet of the first embodiment, the thickness of each elastomer layer can be set arbitrarily and can be independently set to, for example, 5 μm to 100 μm.

[0013] In the reinforced elastomer sheet of the first embodiment, the thickness of each layered reinforcing material is, for example, 1 μm to 100 μm. From the viewpoint of reducing the thickness of the reinforced elastomer sheet, a thinner thickness is preferable, and from the viewpoint of increasing the tensile strength of the layered reinforcing material, a thicker thickness is preferable. From these viewpoints, for example, a thickness of 5 μm to 50 μm is preferable, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 30 μm.

[0014] When viewed in the thickness direction of the reinforced elastomer sheet of the first embodiment (as viewed virtually), the ratio (A / B) of the area A of an arbitrarily selected layered reinforcement material to the area B of the elastomer layer immediately below or above the selected layered reinforcement material is, for example, preferably 0.5 to 2, more preferably 0.8 to 1.2, even more preferably 0.9 to 1.1, and most preferably 1.0.

[0015] The planar shape, size, thickness, etc. of the reinforced elastomer sheet of the first embodiment are appropriately set depending on the application. The planar shape of the sheet may be, for example, a rectangle, a circle, an ellipse, a polygon, or any other shape. The length x width size of the sheet is not particularly limited, and may be, for example, 0.5 cm x 0.5 cm to 10 cm x 10 cm. The thickness of the sheet may be, for example, 10 μm to 1000 μm.

[0016] In the reinforced elastomer sheet of the first embodiment, the linear expansion coefficient of the material constituting each layer of reinforcing material is smaller than the linear expansion coefficient of the elastomer constituting each elastomer layer, specifically, a comparison is made between an arbitrarily selected layer of reinforcing material and an elastomer layer immediately below or above it.

[0017] (Action and effect) When the reinforced elastomer sheet of the first embodiment is placed in a high-temperature environment (e.g., 80 to 150°C), the elastomer layer, which has a linear expansion coefficient larger than that of the layered reinforcing material, tends to expand in the plane direction of the sheet. However, like the elastomer layer, the layered reinforcing material is provided along the plane direction of the sheet. The linear expansion coefficient of the material constituting each layered reinforcing material is smaller than the linear expansion coefficient of the elastomer constituting each elastomer layer. Therefore, the degree of thermal expansion of each layered reinforcing material is smaller than the degree of thermal expansion of each elastomer layer, so that the layered reinforcing material acts to suppress the thermal expansion of each elastomer layer in the plane direction of the sheet directly below or directly above it. As a result, the thermal expansion of the reinforced elastomer sheet of the first embodiment in the plane direction can be suppressed.

[0018] The reinforced elastomer sheet of the first embodiment described above may be used alone, or may be used as a laminate in which a plurality of sheets are laminated, or may be used as a heterogeneous laminate in which another type of sheet-like member is laminated. Examples of other types of sheets include the reinforced elastomer sheet of the second embodiment described below and a resin sheet made of a known resin.

[0019] <Second aspect> 2, a reinforced elastomer sheet 20, which is an example of the second embodiment of the present invention, comprises an elastomer sheet 22 as a main body, and the main body includes a plurality of layered reinforcing materials 21. The main body is a rectangular sheet, with the horizontal direction being the X direction, the vertical direction being the Y direction, and the direction perpendicular to the main surface (i.e., the thickness direction of the sheet) being the Z direction.

[0020] The multiple layered reinforcement materials 21 extend in an arbitrary direction (Y direction in the illustrated example) approximately parallel to each other along one main surface of the elastomer sheet 22. Each of the multiple layered reinforcement materials 21 extends from one main surface to the other main surface, penetrating the other main surface. Here, the main surfaces of the elastomer sheet 22 refer to each of the two surfaces with the largest areas.

[0021] The reinforced elastomer sheet 20 comprises a plurality of strip-shaped elastomer portions α arranged in the planar direction (XY direction) and a plurality of adhesive portions β interposed between each of the elastomer portions α to bond them together. The elastomer portions α and adhesive portions β are arranged alternately when viewed in the X direction, have the same length in the Y direction, and extend in the same direction.

[0022] The width in the X direction of each strip-shaped elastomer portion α in plan view (XY plane view) of reinforced elastomer sheet 20 is preferably wider than the width of adhesive portion β, and can be, for example, about 5 μm to 200 μm. Suitable elastomer materials will be described later.

[0023] The adhesive portion β has an adhesive material 23 that adheres to the adjacent elastomer portion α, and a layered reinforcing material 21. The width of the adhesive portion β (the distance between the adjacent elastomer portions α) can be, for example, about 5 μm to 200 μm.

[0024] The adhesive 23 may be any material capable of adhering to the adjacent elastomer portion α and holding the layered reinforcing material 21, and may be a hardened product of a known adhesive. Suitable adhesives will be described later. In order to adhere the layered reinforcing material 21 to the adjacent elastomer portion α while holding the layered reinforcing material 21, it is preferable that layered adhesive material 23 is disposed on both sides of the layered reinforcing material 21. A part of the adhesive material 23 may be contained inside the layered reinforcing material 21 by impregnation (penetration) or the like.

[0025] The layered reinforcement material 21 extends in the thickness direction (Z direction) of the reinforced elastomer sheet 20, and also extends in the length direction (Y direction in the illustrated example) of the strip-shaped elastomer portion α. ​​In other words, the two main surfaces (widest surfaces) of the layered reinforcement material 21 each face the adjacent elastomer portion α.

[0026] The layered reinforcing material 21 included in one adhesive joint β may be one layer, two layers, or three or more layers. It is preferable that all of the adhesive zones β of the reinforced elastomer sheet 20 contain the layered reinforcing material 21, but it does not matter if some of the adhesive zones β do not contain the layered reinforcing material 21.

[0027] The thickness of the layered reinforcing material 21 (thickness in the X direction in the illustrated example) is, for example, 1 μm to 100 μm. From the viewpoint of increasing the occupancy rate of each elastomer portion α in the X direction, the thinner the thickness is, and from the viewpoint of increasing the tensile strength of the layered reinforcing material 21, the thicker the thickness is. From these viewpoints, for example, 5 μm to 50 μm is preferable, 10 μm to 40 μm is more preferable, and 15 μm to 30 μm is even more preferable.

[0028] Since the layered reinforcement 21 extends in the Z and Y directions along the elastomer portion α, even if the elastomer portion α expands due to heat, the layered reinforcement 21 does not follow the expansion, suppressing the thermal expansion of the reinforced elastomer sheet 20 in the Z and Y directions in a high temperature environment. From the viewpoint of fully obtaining this effect, it is preferable that the linear expansion coefficient of the material constituting the layered reinforcement 21 is smaller than that of the elastomer sheet 22 and the elastomer portion α. ​​In addition, it is preferable that the tensile modulus of the material constituting the layered reinforcement 21 is larger than that of the elastomer constituting the elastomer sheet 22 and the elastomer portion α (i.e., it is difficult to deform under tensile stress). A suitable layered reinforcement 21 will be described later.

[0029] The length of the layered reinforcement material 21 in the thickness direction (Z direction) of the reinforced elastomer sheet 20 is preferably 50 to 100% of the thickness of the reinforced elastomer sheet 20, more preferably 70 to 100%, even more preferably 90 to 100%, and most preferably 100%. When it is 100%, the layered reinforcement material 21 penetrates in the thickness direction (Z direction) of the reinforced elastomer sheet 20 and is exposed on one main surface 22a and the other main surface 22b of the elastomer sheet 22. That is, in a plan view of one main surface 22a or the other main surface 22b of the elastomer sheet 22, the multiple layered reinforcement materials 21 extend approximately parallel to each other in any direction (Y direction in the illustrated example) and most preferably penetrate from one main surface 22a to the other main surface 22b of the elastomer sheet 22. When the Z-direction length of the layered reinforcement material 21 is within the above-mentioned preferred range, the contact area in the Z-direction between the adhesive portion β containing the layered reinforcement material 21 and the adjacent elastomer portion α is increased, thereby further suppressing the thermal expansion of the reinforced elastomer sheet 20 in the Z-direction.

[0030] 3, each layered reinforcing material 21 extending along the Z direction may be inclined at any angle or may be perpendicular to each main surface of the elastomer sheet 22, and is preferably perpendicular. The angle of inclination of each layered reinforcing material 21 to the main surface in a cross-sectional view in the thickness direction may be, for example, about 0 to 20° on the acute angle side.

[0031] The length of the layered reinforcement 21 along the longitudinal direction (Y direction) of the elastomer portion α is preferably 50 to 100% of the length of the adjacent elastomer portion α, more preferably 70 to 100%, even more preferably 90 to 100%, and most preferably 100%. When it is 100%, the layered reinforcement 21 penetrates the reinforced elastomer sheet 20 in the longitudinal direction (Y direction) and is exposed on the side surface of the elastomer sheet 22. When the length of the layered reinforcement 21 in the Y direction is within the above-mentioned preferred range, the contact area in the Y direction between the adhesive portion β including the layered reinforcement 21 and the elastomer portion α increases, so that the effect of suppressing the thermal expansion of the reinforced elastomer sheet 20 in the Y direction is further improved.

[0032] The reinforced elastomer sheet of the second embodiment may have a shape other than that shown in the drawings. The shape, size, thickness, etc. of the sheet in a plan view are appropriately set depending on the application. The shape of the sheet in a plan view is not limited to a rectangle, and may be, for example, a circle, an ellipse, a polygon, or any other shape. The extension direction of the layered reinforcing material in the plan view of the sheet may be along the edge of the outer shape of the sheet body, or may be in any direction without following the edge. The length x width size of the reinforced elastomer sheet is not particularly limited and can be, for example, 0.5 cm x 0.5 cm to 10 cm x 10 cm. The thickness of the reinforced elastomer sheet can be, for example, from 20 μm to 1000 μm.

[0033] (Action and effect) When the reinforced elastomer sheet 20 of the second embodiment is placed in a high-temperature environment (e.g., 80 to 150°C), the strip-shaped elastomer portion α, which has a linear expansion coefficient larger than that of the layered reinforcement material 21, tends to expand in the plane direction (XY direction) and the thickness direction (Z direction). However, the layered reinforcement material 21 is provided at the adhesive portion β adjacent to each elastomer portion α. ​​The layered reinforcement material 21 has a planar structure on the ZY plane. The linear expansion coefficient of the material constituting the layered reinforcement material 21 is smaller than the linear expansion coefficient of the elastomer constituting each elastomer portion α. ​​Therefore, the degree of thermal expansion of the layered reinforcement material 21 is smaller than the degree of thermal expansion of each elastomer portion α, so that the layered reinforcement material 21 acts to suppress the thermal expansion of each elastomer portion α in the Y direction and Z direction at its sides. As a result, the layered reinforcement material 21 can suppress the thermal expansion of the reinforced elastomer sheet 20 in the vertical direction (Y direction) and the thickness direction (Z direction).

[0034] <Reinforced elastomer sheet laminate> A third aspect of the present invention is a reinforced elastomer sheet laminate in which a plurality of sheets arbitrarily selected from the reinforced elastomer sheets of the second aspect are laminated with their main surfaces facing each other.

[0035] When viewed in the stacking direction of the reinforced elastomer sheet laminate, that is, when viewed virtually through the overlap of all the reinforced elastomer sheets, the crossing angle between the extension direction of one or more layer reinforcements arbitrarily selected in the first reinforced elastomer sheet (the extension direction in the plane direction of the first reinforced elastomer sheet) and the extension direction of one or more layer reinforcements arbitrarily selected in the second reinforced elastomer sheet (the extension direction in the plane direction of the second reinforced elastomer sheet) is preferably 10 to 90°, more preferably 30 to 90°, even more preferably 50 to 90°, and particularly preferably 70 to 90°, when viewed on the acute angle side.

[0036] When the crossing angle is within the above range, the thermal expansion in the plane direction of the reinforced elastomer sheet laminate can be further suppressed. This mechanism will be explained in detail. For example, the layered reinforcing material of the first reinforced elastomer sheet extends in the direction of 0° in the plane direction of the reinforced elastomer sheet laminate. And the layered reinforcing material of the second reinforced elastomer sheet extends in the direction of 90° in the plane direction of the reinforced elastomer sheet laminate. Then, when viewed in the plane direction of the reinforced elastomer sheet laminate, the thermal expansion in the direction of 0° is suppressed by the first reinforced elastomer sheet, and the thermal expansion in the direction of 90° is suppressed by the second reinforced elastomer sheet. Therefore, in the reinforced elastomer sheet laminate, the thermal expansion in two mutually orthogonal directions of 0° and 90° in the plane direction can be suppressed. Furthermore, the thermal expansion in the direction of 45° in the plane direction is also suppressed by the layered reinforcing materials of the first and second reinforced elastomer sheets. Furthermore, the thermal expansion of the reinforced elastomer sheet laminate in the stacking direction (thickness direction) is suppressed by the layered reinforcing material contained in each reinforced elastomer sheet.

[0037] When the above-mentioned reinforced elastomer sheet laminate includes three or more reinforced elastomer sheets, the extending direction of the layered reinforcing material of the third or subsequent reinforced elastomer sheets may be the same as or may cross the extending direction of the layered reinforcing material of the first or second reinforced elastomer sheet. From the viewpoint of suppressing thermal expansion in uniform directions, it is preferable that the extending directions of the layered reinforcing materials of each reinforced elastomer sheet have equal crossing angles with each other when viewed in the stacking direction of the reinforced elastomer sheet laminate.

[0038] <Functional layer> A functional layer may be disposed on at least one of the main surfaces of the reinforced elastomer sheets according to the first to third aspects of the present invention described above. Examples of the functional layer include an adhesive layer, an anti-blocking layer, and a solid layer. Examples of the adhesive layer include an adhesive layer made of an adhesive directly laminated onto the main surface, and an adhesive layer made of an optional base layer adhered to the main surface and an adhesive laminated onto the base layer. The anti-blocking layer may be made of a silicone rubber layer laminated on the main surface, and the surface may be matte-finished (embossed) to form projections and recesses, providing a smooth feel when touched and providing slippery properties. The solid layer may be made of any resin layer such as PET adhered to the main surface via an adhesive layer.

[0039] <Method of manufacturing reinforced elastomer sheet> The fourth aspect of the present invention is a method for producing a reinforced elastomer sheet, which includes a lamination step and a cutting step. According to the production method of this aspect, the reinforced elastomer sheet of the second aspect can be produced. Moreover, the reinforced elastomer sheet (laminate) of the first aspect and the third aspect can be produced by referring to the production method of this aspect.

[0040] [Lamination process] The lamination step is a step of obtaining a block laminate by laminating a plurality of elastomer layers with their main surfaces facing each other and interposing an adhesive and a layered reinforcing material between the main surfaces. Specifically, for example, two elastomer layers 24 made of an elastomer film are prepared, and an adhesive layer made of an adhesive is formed on one main surface of each elastomer layer 24. Next, one main surface of the layered reinforcing material 21 is attached to the adhesive layer of the first elastomer layer 24. As a result, at least a part or the whole of one main surface of the first elastomer layer 24 is covered with the layered reinforcing material 21. Next, one main surface of the second elastomer layer 24 is attached to the other main surface of the layered reinforcing material 21 attached to the first elastomer layer 24 via the adhesive layer. As a result, a laminate is obtained in which the main surfaces of the two elastomer layers 24 face each other and are attached via the adhesive 23 formed by the cured adhesive layer and the layered reinforcing material 21. By sequentially stacking the elastomer layers 24 in this manner, a block laminate 28 in which a desired number of elastomer layers 24 are stacked is obtained (see FIG. 4). In the block laminate 28 , each layered reinforcing material 21 covers at least a portion of the main surface of each elastomer layer 24 in the gaps between the elastomer layers 24 .

[0041] In the block laminate 28 illustrated in FIG. 4, eight elastomer layers 24 are laminated, with one layer of layered reinforcing material 21 provided between each of the elastomer layers 24. It is preferable that the layered reinforcement material 21 is provided in all of the gaps between the elastomer layers 24 in the block laminate 28, but it is sufficient that the layered reinforcement material 21 is provided in at least one gap. The layered reinforcement material 21 provided in each gap may be one layer (one sheet), two layers (two sheets), or three layers (three sheets) or more. From the viewpoint of increasing the adhesive strength of the adhesive portion β, it is preferable that the layered reinforcement material 21 provided in each gap be one or two layers, and more preferably one layer.

[0042] Examples of the elastomer material forming each elastomer layer 24 include silicone rubber, urethane rubber, isoprene rubber, ethylene propylene rubber, natural rubber, ethylene propylene diene rubber, and styrene butadiene rubber. Among these, silicone rubber is preferred because it is less likely to cause dimensional changes or warping after curing, has small compression set, and has high heat resistance. The silicone rubber may be either a heat curing type (addition type, organic peroxide type) or a room temperature curing type (addition type, condensation type). Each elastomer layer may independently be a dense solid rubber or a foamed rubber.

[0043] The elastomer material may contain appropriate amounts of known additives, such as a catalyst for promoting polymerization of resins, a crosslinking agent for promoting crosslinking between resins, an antioxidant, a dye, a pigment, a filler, a leveling agent, a foaming agent, and the like.

[0044] A known adhesive can be used as the adhesive forming the adhesive material 23. From the viewpoint of enhancing adhesion to the elastomer layer 24, it is preferable to use an adhesive that becomes the same as the elastomer material constituting the elastomer layer 24 after curing. In this case, the adhesive material 23 and the elastomer layer 24 may be the same.

[0045] As viewed in the X direction in FIG. 4, the thickness of the adhesive portion β consisting of the adhesive 23 and the layered reinforcing material 21 is preferably thinner than the thickness of each elastomer layer 24, from the viewpoint of reducing the thickness of the block laminate 28.

[0046] In the block laminate 28, the linear expansion coefficient (thermal expansion coefficient) of the material constituting the arbitrarily selected layered reinforcement 21 is smaller than the linear expansion coefficient of the elastomer constituting the elastomer layer 24 directly below or directly above the layered reinforcement 21.

[0047] When the layered reinforcement material 21 is made of a plurality of materials (when the layered reinforcement material 21 is a composite material), the linear expansion coefficient of each component material is multiplied by the volume fraction of each component material to obtain the linear expansion coefficient of the composite material. For example, when the volume fraction of material A taken out from the layered reinforcement material 21 is 40%, and the volume fraction of material B taken out from the layered reinforcement material 21 is 60%, the linear expansion coefficient of the composite material is obtained by [linear expansion coefficient of material A × volume fraction of material A (0.4) + linear expansion coefficient of material B × volume fraction of material B (0.6)]. Note that the elastomer impregnated in the layered reinforcement material 21 is not considered to be a material that constitutes the layered reinforcement material 21.

[0048] The expansion ratio R, expressed as (linear expansion coefficient of the elastomer constituting each elastomer layer 24)÷(linear expansion coefficient of the material constituting the layered reinforcing material 21), is preferably 2 or more, more preferably 5 or more, and even more preferably 10 or more. There is no particular upper limit, and it may be 100 or 1000. The larger the expansion ratio R, the greater the effect of the layered reinforcing material 21 in suppressing the thermal expansion of the elastomer layer 24.

[0049] The linear expansion coefficient of silicone rubber (unit: 1 / K) is approximately 300 x 10-6 When the elastomer constituting the elastomer layer 24 is silicone rubber, the linear expansion coefficient of the material constituting the layered reinforcing material 21 is 200×10 -6 Less than or equal to 100×10 -6 Less than 50×10 is preferable. -6 The lower the linear expansion coefficient of the material of the layered reinforcing material 21, the more the thermal expansion of the elastomer layer 24 adjacent to the adhesive portion β can be suppressed in a high-temperature environment. The lower limit of the linear expansion coefficient of the material of the layered reinforcing material 21 is not particularly limited, and is preferably 1×10 -6 The degree is given as a guideline.

[0050] The linear expansion coefficients of common materials are shown below. The numbers in parentheses are the linear expansion coefficients (unit: x 10 -6 / K); copper (17.7), titanium (8.4), polypropylene (about 70), polyethylene (about 130), polycarbonate (66), polyethylene terephthalate (65), polyether ether ketone (about 40), polyamide imide (30.6).

[0051] When the elastomer constituting the elastomer layer 24 is silicone rubber, the material of the layered reinforcing material 21 is preferably a resin having the above-mentioned suitable linear expansion coefficient, more preferably a liquid crystal polymer having excellent heat resistance and tensile strength, or more preferably polyarylate (linear expansion coefficient: 25×10 -6 / K is more preferable.

[0052] The layered reinforcement material 21 constituting the block laminate 28 may have any shape as long as it is layered, and examples of such layered reinforcement material include a flat plate, a film, a cloth, etc. The size of the layered reinforcement material 21 is preferably approximately the same as that of one main surface of the elastomer layer 24, and examples of the approximate length x width size include 10 cm x 10 cm to 100 cm x 100 cm.

[0053] The thinner the layered reinforcement material 21, the thinner the thickness of the block laminate 28 (X direction in FIG. 4) can be, but a certain thickness is necessary to function as a reinforcement material that suppresses thermal expansion in a high-temperature environment. In consideration of this balance, the thickness of the layered reinforcement material 21 (X direction in FIG. 4) is preferably 1 μm to 100 μm, more preferably 5 μm to 50 μm, and even more preferably 10 μm to 30 μm.

[0054] If the stiffness of the layered reinforcement 21 in the plane direction (direction along the main surface of the layered reinforcement 4) is excessively high, the rubber elasticity of the reinforced elastomer sheet in the thickness direction (Z direction in FIG. 4) may be impaired. For this reason, the layered reinforcement 21 is preferably flexible enough to flexibly deform when a compressive force is applied in the plane direction. From this viewpoint, the layered reinforcement 21 is preferably a porous material having a large number of voids on the surface or inside. Suitable porous materials include, for example, sponge-like porous materials, felt, nonwoven fabrics, and the like.

[0055] When the layered reinforcing material 21 is a nonwoven fabric, its air permeability (unit: cc / cm 2 / sec) is preferably from 10 to 500, more preferably from 50 to 300, and even more preferably from 100 to 250. When the thickness is equal to or greater than the lower limit of the above range, the flexibility (compressibility) in the layer direction of the layered reinforcement material 21 is increased. Also, the adhesive in contact with the layered reinforcement material 21 is more likely to penetrate into the layered reinforcement material 21, improving the adhesiveness. When the thickness is equal to or less than the upper limit of the above range, the tensile strength of the layered reinforcement material 21 is increased.

[0056] When the layered reinforcing material 21 is a nonwoven fabric, the thickness thereof is preferably 5 μm to 50 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 30 μm. When it is equal to or greater than the lower limit of the above range, the tensile strength of the layered reinforcing material 21 increases. When it is equal to or less than the upper limit of the above range, the flexibility (compressibility) of the layered reinforcing material 21 in the layer direction is increased.

[0057] When the layered reinforcing material 21 is a nonwoven fabric, its tensile strength (unit: N / 1.5 cm) in at least one arbitrary direction, for example, the Y direction in Fig. 2, is preferably 3 or more, more preferably 5 or more, and even more preferably 10 or more. The higher the tensile strength of the layered reinforcing material 21, the easier it is to suppress the thermal expansion of the elastomer layer 24. The upper limit of the tensile strength is not particularly limited, and a guideline is, for example, about 100.

[0058] When the layered reinforcing material 21 is a nonwoven fabric, its elongation (unit: %) in at least one arbitrary direction, for example, the Y direction in Fig. 2, is preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less. The smaller the elongation of the layered reinforcing material 21, the easier it is to suppress the thermal expansion of the elastomer layer 24. The lower limit of the elongation is not particularly limited, and a guideline is, for example, about 0.5.

[0059] When the layered reinforcing material 21 is a nonwoven fabric, its basis weight (unit: g / m 2 ) is preferably 1 to 50, more preferably 2 to 30, and even more preferably 3 to 20. When it is equal to or greater than the lower limit of the above range, the tensile strength of the layered reinforcing material 21 can be increased. When it is equal to or less than the upper limit of the above range, the reinforced elastomer sheet becomes light in weight and its handling properties improve.

[0060] When the layered reinforcing material 21 is a nonwoven fabric, the average fiber diameter (unit: μm) of the fibers constituting the nonwoven fabric is preferably 0.5-20, more preferably 1-10, and even more preferably 3-7. When it is equal to or greater than the lower limit of the above range, the tensile strength of the layered reinforcing material 21 can be increased. When it is equal to or less than the upper limit of the above range, the thickness and basis weight of the layered reinforcing material 21 can be reduced. The average fiber diameter is an average value of diameters at arbitrarily selected points of 30 or more randomly selected fibers measured by image processing or the like, taken from an SEM image of the nonwoven fabric.

[0061] In general, nonwoven fabrics are manufactured by a fleece process in which a fleece (web) is formed by overlapping fibers, and an interfiber bonding process in which the fibers that make up the fleece are bonded to each other. Known methods for producing fleece include the dry method (a method in which fibers are stacked together in a dry state), the wet method (a method in which short fibers are dispersed in water), the spunbond method (a method in which long fibers obtained by melting and spinning a resin are directly stacked), the meltblown method (a method in which, when molten resin is discharged from a spinning nozzle, high-temperature air is sprayed from around the spinning nozzle to thin the fibers and stack them in a sheet shape), etc. Among these, nonwoven fabrics formed by the meltblown method, which can reduce the fiber diameter and produce nonwoven fabrics composed only of thin fibers, are particularly suitable as the layered reinforcing material 21. Known methods for bonding the fibers that make up fleece include the thermal bonding method, the chemical bonding method (impregnation method, spray method), and the needle punch method.

[0062] When the layered reinforcing material 21 is a nonwoven fabric, the type of fiber constituting the nonwoven fabric is not particularly limited as long as the linear expansion coefficient of the material constituting the fiber is smaller than the linear expansion coefficient of the elastomer. For example, natural fibers, chemical fibers, and other fibers can be mentioned. Examples of natural fibers include cellulosic materials such as cotton, hemp, pulp, silk (fibroin), and mineral fibers. Examples of chemical fibers include rayon, polyamide resins such as nylon and aramid, polyester resins such as vinylon, PET and PEN, polypropylene, (meth)acrylic resins, polyarylate and liquid crystal polymers having parahydroxybenzoic acid as a monomer unit. Other fibers include, for example, glass fibers. Among these, chemical fibers are preferable as the material for the layered reinforcing material 21, and fibers made of liquid crystal polymers are more preferable, because the linear expansion coefficient is easy to measure and control.

[0063] [Cutting process] The block laminate 28 obtained in the previous step is cut to a desired thickness and size in a direction transverse to the plane direction of each layered reinforcing material 21 in the block laminate 28, thereby obtaining a reinforced elastomer sheet 20 (see FIG. 5).

[0064] Regarding the method of taking the cut surface, for example, when cutting in a direction perpendicular to the surface direction of each layered reinforcement material 21, the surface direction of each layered reinforcement material 21 intersects perpendicularly with the main surface (cut surface) of the reinforced elastomer sheet 20. Also, when cutting at an arbitrary angle with respect to the surface direction of each layered reinforcement material 21, the surface direction of each layered reinforcement material 21 intersects with the main surface (cut surface) of the reinforced elastomer sheet 20 at an arbitrary angle (the surface of each layered reinforcement material 21 is disposed at an angle with respect to the main surface).

[0065] In the plan view (XY plane view) of reinforced elastomer sheet 20 shown in Fig. 2, the length direction of layered reinforcement material 21 is along the Y direction, but the length direction of layered reinforcement material 21 is not limited to the Y direction and can be set in any direction. For example, by pressing a rectangular punch die against reinforced elastomer sheet 20 in any direction to cut it out, a rectangular reinforced elastomer sheet (not shown) smaller than reinforced elastomer sheet 20 can be obtained. The length direction of layered reinforcement material 21 in the plan view of this rectangular reinforced elastomer sheet can be set as desired depending on the direction in which the punch die is pressed against it. EXAMPLES

[0066] [Example 1] An elastomer layer (elastomer film) of 30 μm thickness made of uncured silicone rubber was formed on a PET substrate, cured, and then the PET substrate was peeled off. 2000 sheets of the elastomer layers thus prepared were laminated to obtain a block laminate. At this time, uncured silicone rubber was applied to the main surface of each elastomer layer, and nonwoven fabric was attached, so that an adhesive made of silicone rubber and nonwoven fabric were interposed in the gaps between each elastomer layer. The nonwoven fabric used here is Veclus (registered trademark) manufactured by Kuraray Kuraflex Co., Ltd. using the melt-blown method, and is made of polyarylate fibers (average fiber diameter 3 μm), which is a liquid crystal polymer, and has a basis weight of 4 g / cm. 2 , thickness 16μm, tensile strength 11N / 1.5cm (MD direction), elongation 3% (MD direction), air permeability 204cc / cm 2 / second. The linear expansion coefficient of hardened silicone rubber is 300×10 -6 / K, and the linear expansion coefficient of the fiber (polyarylate) that composes the nonwoven fabric is 25×10 -6 / K.

[0067] Next, the nonwoven fabric between the elastomer layers was sliced ​​at an angle of about 60° to obtain a reinforced elastomer sheet having a thickness of 150 μm. This was then molded into a size of 5 cm x 8 cm in the X direction x Y direction, and had the same structure as the reinforced elastomer sheet 20 already shown in the figure.

[0068] [Comparative Example 1] An elastomer sheet laminate was obtained in the same manner as in Example, except that no nonwoven fabric was interposed between the elastomer layers.

[0069] <Evaluation by Heating Test 1> The vicinity of two sides in the X direction of the reinforced elastomer sheet produced above was fastened with metal clips, and the reinforced elastomer sheet was fixed in a state of being lightly pulled in the Y direction so as not to loosen, and heated on a hot plate. As a result, it was visually confirmed that the deformation due to thermal expansion of the reinforced elastomer sheet of Example 1 was smaller than that of the comparative example at both 90°C and 120°C. In other words, the thermal expansion of the reinforced elastomer sheet of Example 1 in the Y direction and Z direction (plane direction of the layered reinforcing material 21) was suppressed compared to the comparative example.

[0070] [Example 2] Two reinforced elastomer sheets prepared in Example 1 were prepared, and laminated with their main surfaces facing each other via a silicone rubber adhesive to obtain a reinforced elastomer sheet laminate. At this time, the sheets were laminated so that the Y direction of one reinforced elastomer sheet was perpendicular to the Y direction of the other reinforced elastomer sheet, so that the cross angle between the extension direction of the layered reinforcing material of one reinforced elastomer sheet and the extension direction of the layered reinforcing material of the other reinforced elastomer sheet was about 90° when viewed in the lamination direction of the reinforced elastomer sheet laminate.

[0071] [Comparative Example 2] Two elastomer sheets produced in Comparative Example 1 were prepared, and laminated with their main surfaces facing each other via a silicone rubber adhesive to obtain an elastomer sheet laminate.

[0072] <Evaluation by heating test 2> Heating tests were conducted using the method described above for the reinforced elastomer sheet laminate of Example 2 and the elastomer sheet laminate of Comparative Example 2. As a result, the thermal expansion of Example 2 was suppressed in the two mutually perpendicular Y directions (two directions in a plan view) and the Z direction of each reinforced elastomer sheet compared to the thermal expansion of Comparative Example 2. [Explanation of symbols]

[0073] 1...Layered reinforcing material, 1a...One main surface, 1b...The other main surface, 2A, 2B...Elastomer layer, 21...Layered reinforcing material, 22...Elastomer sheet, 22a...One main surface, 22b...Other main surface, 23...Adhesive, 24...Elastomer layer, 28...Block laminate, α...Elastomer portion, β...Adhesive portion, 10...Reinforced elastomer sheet, 20...Reinforced elastomer sheet

Claims

1. A reinforced elastomer sheet having an elastomer sheet as a main body, the main body including a plurality of layered reinforcing materials, the plurality of layered reinforcement materials extend generally parallel to one another in any direction along one main surface of the elastomeric sheet, and each of the plurality of layered reinforcement materials extends from the one main surface to the other main surface; a thermal expansion-suppressed reinforced elastomer sheet laminate in which a plurality of sheets arbitrarily selected from thermal expansion-suppressed reinforced elastomer sheets, the thermal expansion of which is suppressed and the material constituting the layered reinforcing material has a linear expansion coefficient smaller than the linear expansion coefficient of the elastomer constituting the elastomer sheet, are laminated with their main surfaces facing each other, A reinforced elastomer sheet laminate having suppressed thermal expansion, wherein the crossing angle between the extending direction of one arbitrarily selected layer reinforcing material in the first reinforced elastomer sheet and the extending direction of one arbitrarily selected layer reinforcing material in the second reinforced elastomer sheet is 10 to 80° when viewed in the lamination direction of the reinforced elastomer sheet laminate.

2. A reinforced elastomeric sheet comprising an elastomer and a plurality of layered reinforcements, The elastic member has a plurality of strip-shaped elastomer portions arranged in a planar direction, and a plurality of adhesive portions interposed between the respective elastomer portions to bond the elastomer portions to each other, the adhesive portion includes an adhesive material that adheres to the elastomer portion, and a layer-like reinforcing material that is in contact with the adhesive material, extends in a thickness direction of the reinforced elastomer sheet, and extends in a length direction of the strip-like elastomer portion; a thermal expansion-suppressed reinforced elastomer sheet laminate in which a plurality of sheets arbitrarily selected from thermal expansion-suppressed reinforced elastomer sheets, the thermal expansion coefficient of which is smaller than the linear expansion coefficient of the material constituting the layered reinforcing material, are laminated with their main surfaces facing each other, A reinforced elastomer sheet laminate having suppressed thermal expansion, wherein the crossing angle between the extending direction of one arbitrarily selected layer reinforcing material in the first reinforced elastomer sheet and the extending direction of one arbitrarily selected layer reinforcing material in the second reinforced elastomer sheet is 10 to 80° when viewed in the lamination direction of the reinforced elastomer sheet laminate.

3. A reinforced elastomer sheet comprising an elastomer sheet as a main body, the main body including a plurality of layered reinforcing materials, the plurality of layered reinforcement materials extend generally parallel to one another in any direction along one main surface of the elastomeric sheet, and each of the plurality of layered reinforcement materials extends from the one main surface to the other main surface; a reinforced elastomer sheet having a thermal expansion suppressed, the linear expansion coefficient of a material constituting the layered reinforcing material being smaller than the linear expansion coefficient of an elastomer constituting the elastomer sheet; And, A reinforced elastomeric sheet comprising an elastomer and a plurality of layered reinforcements, The elastic member has a plurality of strip-shaped elastomer portions arranged in a planar direction, and a plurality of adhesive portions interposed between the respective elastomer portions to bond the elastomer portions to each other, the adhesive portion includes an adhesive material that adheres to the elastomer portion, and a layer-like reinforcing material that is in contact with the adhesive material, extends in a thickness direction of the reinforced elastomer sheet, and extends in a length direction of the strip-like elastomer portion; a reinforced elastomer sheet having a thermal expansion suppressed, the linear expansion coefficient of a material constituting the layered reinforcing material being smaller than the linear expansion coefficient of the elastomer; a laminate of reinforced elastomer sheets having thermal expansion suppressed, the laminate being formed by stacking a plurality of sheets selected from the group consisting of the following, with their main surfaces facing each other; A reinforced elastomer sheet laminate having suppressed thermal expansion, wherein the crossing angle between the extending direction of one arbitrarily selected layer reinforcing material in the first reinforced elastomer sheet and the extending direction of one arbitrarily selected layer reinforcing material in the second reinforced elastomer sheet is 10 to 80° when viewed in the lamination direction of the reinforced elastomer sheet laminate.

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