Seal material

Abstract

The present invention addresses the problem of providing a seal material that is exceptional in terms of the strength of a fiber base body and overall cushioning properties. This sheet material (10) comprises a fiber substrate (11), an undercoat layer (12) provided on one main surface (11a) of the fiber substrate (11), and an adhesive layer (13) provided on the undercoat layer (12). The undercoat layer (12) is composed of a resin (A) having a glass transition temperature of 25°C or higher. The adhesive layer (13) is composed of a resin (B) other than the resin used for the undercoat layer (12). The thickness of the seal material (10) is 2-15 mm. The relationship X2 < X1 holds, where X1 mg is the organic component content of a layer at 1 mm from the surface of the sealing material (10) on the adhesive-layer (13) side, excluding the adhesive layer (13), and X2 mg is the organic component content of all remaining portions of the seal material (10) excluding the adhesive layer (13) and the layer at 1 mm from the bottom of the adhesive layer (13) from the surface on the adhesive-layer (13) side.

Description

sealing material

[0001] The present invention relates to a sealing material.

[0002] Sealing materials are used, for example, as materials for filling gaps that occur between building frames such as pillars and beams and gypsum boards or fire doors that constitute wall surfaces. They are also used as materials for filling gaps that occur between windows and housings of water heaters, etc. Sealing materials include a fiber-containing substrate, an adhesive layer formed by coating one entire surface of the substrate with an adhesive, and a release sheet provided on the adhesive layer.

[0003] Sealing materials with an adhesive layer require substrate surface strength and cushioning properties. Substrate surface strength is necessary to prevent the substrate from succumbing to the peeling force when the release sheet is peeled off, causing delamination at the surface layer. Cushioning properties are necessary to fully demonstrate the cushioning properties that are the function of the sealing material. If the substrate surface strength is improved, the sealing material becomes hard and the cushioning properties decrease. On the other hand, if the cushioning properties are improved, the strength of the sealing material decreases, causing delamination at the surface layer. In other words, there is a trade-off between substrate surface strength and cushioning properties.

[0004] A sealing material is known that includes a sheet-like fiber substrate, a fiber-sealing undercoat layer provided on the surface of the sheet-like fiber substrate, an adhesive layer in which adhesive is formed in dots on the undercoat layer, and a release sheet provided on the adhesive layer, the adhesive layer having a thickness of 100 μm to 200 μm (see, for example, Patent Document 1). This sealing material prevents the fibers on the surface of the fiber-containing substrate from adhering to the release sheet via the adhesive layer and being peeled off.

[0005] In a method for producing an adhesive tape in which a hot melt adhesive is applied to one side of a porous substrate to form an adhesive layer, a method for producing an adhesive tape is known in which a liquid incompatible with the hot melt adhesive is applied to the porous substrate, and then a hot melt adhesive containing a thermoplastic block copolymer rubber as a main component is applied to the liquid-applied surface (see, for example, Patent Document 2). This production method can suppress the penetration of the adhesive into the porous substrate, thereby reducing the amount of excess adhesive used, and can produce an adhesive tape with high productivity.

[0006] The density of the pulp-based material is 0.30 g / cm ３ ~1.00 g / cm ３ A method for suppressing the penetration of a hydrophilic coating into a coated base paper is known, in which a dry film layer of an organic polymer gel is first formed on the surface of the paper before the hydrophilic coating is applied (see, for example, Patent Document 3). This method can efficiently suppress the penetration of a hydrophilic coating into the surface of low-density, high-bulk paper.

[0007] JP-A-11-269441 JP-A-9-310049 JP-A 2007-107171

[0008] However, the inventions described in Patent Documents 1 to 3 did not provide a sealing material that was excellent in substrate surface strength and cushioning properties.

[0009] The present invention has been made in view of the above circumstances, and has as its object to provide a sealing material having excellent surface strength of a fiber substrate and excellent overall cushioning properties.

[0010] The present invention has the following aspects: [1] A sealing material comprising a fiber substrate, an undercoat layer provided on one main surface of the fiber substrate, and a pressure-sensitive adhesive layer provided on the undercoat layer, wherein the fiber substrate is made of inorganic fibers, the undercoat layer is made of a resin (A) having a glass transition temperature of 25°C or higher, the pressure-sensitive adhesive layer is made of a resin (B) other than the resin used in the undercoat layer, the thickness of the sealing material is 2 mm or more and 15 mm or less, and the organic content in a layer 1 mm from the surface of the sealing material on the pressure-sensitive adhesive layer side is X １ mg, and the organic content in a layer 1 mm from the surface of the sealing material on the adhesive layer side excluding the adhesive layer is X １ mg, and the organic content in the entire remaining portion of the surface of the sealing material on the adhesive layer side excluding the adhesive layer and a layer 1 mm below it is represented by X ２ When expressed as mg, X ２ <X １[2] The sealing material according to [1], wherein the resin (A) is an aqueous resin. [3] The sealing material according to [1] or [2], wherein the resin (B) is a resin having a glass transition temperature of -80°C or higher and 0°C or lower. [4] The sealing material according to any one of [1] to [3], wherein the resin (B) is an aqueous acrylic resin. [5] The density of the fiber substrate is 160 kg / m ３ Above, 250kg / m ３ [6] The sealing material according to any one of [1] to [4], wherein the thickness of the fiber substrate is 2 mm or more and less than 15 mm. [7] The sealing material according to any one of [1] to [6], wherein a release paper is provided on the pressure-sensitive adhesive layer.

[0011] According to the present invention, it is possible to provide a sealing material that is excellent in strength of the fiber substrate and in overall cushioning properties.

[0012] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.

[0013] A sealing material according to one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a sealing material according to one embodiment of the present invention taken along the longitudinal direction of the sealing material. FIG. 2 is a perspective view of a sealing material according to one embodiment of the present invention. Note that, for the sake of clarity, the drawings used in the following description may show characteristic portions enlarged for convenience, and the dimensional ratios of each component may differ from the actual ones. Furthermore, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited thereto. Appropriate modifications may be made within the scope of the present invention.

[0014] 1 and 2 , a sealing material 10 of this embodiment includes a fiber substrate 11, an undercoat layer 12 provided on one main surface 11a of the fiber substrate 11, and an adhesive layer 13 provided on the undercoat layer 12. The sealing material 10 of this embodiment may also include a release paper 14 provided on the adhesive layer 13.

[0015] Furthermore, any shape can be selected for the sealing material 10 in plan view, and Fig. 2 shows a rectangular shape as an example.

[0016] (Fiber Base) The fiber base 11 is the main body of the sealing material 10, and has an undercoat layer 12 provided on one main surface 11a thereof. The fibers of the fiber base 11 are composed only of inorganic fibers.

[0017] Examples of inorganic fibers include amorphous fibers such as biosoluble ceramic fibers, glass fibers, glass wool, and rock wool fibers; polycrystalline fibers such as carbon fibers, activated carbon fibers, and alumina fibers; and minerals such as sepiolite. Among these, amorphous fibers are preferred from the viewpoint of cost. Of these, rock wool fibers are more preferred. These inorganic fibers may be used alone or in combination of two or more.

[0018] The average fiber diameter of the inorganic fibers is preferably 3 μm or more and 20 μm or less, and more preferably 3 μm or more and 7 μm or less. When the average fiber diameter of the inorganic fibers is equal to or greater than the above-mentioned lower limit, the strength (shape retention) of the fiber substrate 11 is improved. When the average fiber diameter of the inorganic fibers is equal to or less than the above-mentioned upper limit, the uniformity of the strength of the fiber substrate 11 is improved. The average fiber diameter of the inorganic fibers is the arithmetic mean of the area diameters obtained by calculating the cross-sectional area perpendicular to the longitudinal direction of the inorganic fibers using a known calculation method based on vertical cross-sections at any 20 points of the fiber substrate 11 photographed with a microscope, and then calculating the diameter of a perfect circle having the same area as the cross-sectional area.

[0019] The average fiber length of the inorganic fibers is preferably 3 mm or more and 35 mm or less, and more preferably 5 mm or more and 25 mm or less. When the average fiber length of the inorganic fibers is equal to or greater than the lower limit, the strength of the fiber substrate 11 is improved. When the average fiber length of the inorganic fibers is equal to or less than the upper limit, the uniformity of the strength of the fiber substrate 11 is improved. The average fiber length of the inorganic fibers is the arithmetic mean value of the longitudinal lengths of 20 inorganic fibers randomly selected under a microscope.

[0020] The fiber substrate 11 may contain an inorganic binder in addition to the inorganic fibers. Examples of inorganic binders include colloidal silica, fumed silica, alumina sol, zirconia sol, and titania sol. Among these, colloidal silica is preferred from the viewpoint of binder reinforcement of the inorganic fibers. These inorganic binders may be used alone or in combination of two or more.

[0021] The inorganic binder may be a spherical powder, an irregular powder, an emulsion, a sol, or a gel. When the inorganic binder is a spherical powder or an irregular powder, the average particle diameter of the inorganic binder is preferably 7 μm or more and 20 μm or less, and more preferably 9 μm or more and 15 μm or less. When the average particle diameter of the inorganic binder is equal to or more than the lower limit, the strength of the fiber substrate 11 is improved. When the average particle diameter of the inorganic binder is equal to or less than the upper limit, the uniformity of the strength of the fiber substrate 11 is improved. The average particle diameter of the inorganic binder is a value determined by the BET method. Specifically, the average particle diameter of the inorganic binder is determined from the specific surface area of ​​the inorganic binder determined by the BET method and the density of the inorganic binder according to the following formula (1): Average particle diameter of inorganic binder [μm] = 6 / (BET specific surface area [m ２ / g] x density [g / cm ３ ]) (1)

[0022] The fiber substrate 11 may contain organic components in addition to inorganic fibers, such as organic binders, paper strength agents, and polymer flocculants.

[0023] Examples of organic binders include acrylic resin, starch, PVA (polyvinyl alcohol), polyacrylamide, etc. Among these, acrylic resin is preferred from the viewpoint of manufacturing stability and maintaining strength within the layer. These organic binders may be used alone or in combination of two or more. The organic binder may be an emulsion.

[0024] Examples of the acrylic resin include homopolymers of acrylic monomers such as acrylic acid and its esters, methacrylic acid and its esters, acrylamide, and acrylonitrile, or copolymers thereof; and copolymers of at least one of the above acrylic monomers with vinyl monomers such as vinyl acetate, maleic anhydride, and styrene.

[0025] Examples of paper strength agents include melamine resins, urea resins, polyamide epichlorohydrin resins, epoxy resins, dialdehyde starch, polyacrylamide, polyethyleneimine, etc. These paper strength agents may be used alone or in combination of two or more.

[0026] Examples of polymer flocculants include polyacrylamide, polymethacrylic acid ester, polyvinylamine, polyacrylic acid, styrene-based resin, polyethylene oxide, etc. These polymer flocculants may be used alone or in combination of two or more.

[0027] The density of the fiber substrate 11 is 160 kg / m ３ Above, 250kg / m ３ Preferably, 180 kg / m or less ３ Above, 230kg / m ３ The following is more preferable. When the density of the fiber substrate 11 is equal to or greater than the lower limit, the fiber substrate 11 has sufficient strength and is easy to handle. When the density of the fiber substrate 11 is equal to or less than the upper limit, the fiber substrate 11 has sufficient voids and provides sufficient cushioning properties.

[0028] The thickness of the fiber substrate 11 is not particularly limited, but is preferably 2 mm or more and less than 15 mm, and more preferably 5 mm or more and less than 12 mm. If the thickness of the fiber substrate 11 is less than the lower limit, it will not exhibit sufficient cushioning properties as a sealing material and will not be able to conform sufficiently to the unevenness of the surface of other components. If the thickness of the fiber substrate 11 exceeds the upper or lower limit, the fiber substrate 11 will be too thick and difficult to handle when used as a sealing material, and this will lead to an increase in raw material costs, thereby impairing productivity.

[0029] (Undercoat Layer) The undercoat layer 12 is provided on one main surface 11a of the fiber substrate 11. The undercoat layer 12 is formed by applying a resin (A) described below to one main surface 11a of the fiber substrate 11 and drying the applied resin. The undercoat layer 12 has the function of suppressing interlayer delamination of the fiber substrate 11 when the release paper 14 is peeled from the pressure-sensitive adhesive layer 13.

[0030] The undercoat layer 12 is made of a resin (A) having a glass transition temperature of 25° C. or higher. The resin (A) is preferably an aqueous resin. Examples of aqueous resins include acrylic esters, methyl methacrylate, and colloidal silica (aqueous inorganic binder).

[0031] The glass transition temperature of resin (A) is measured using a Q200 (manufactured by TA Instruments Japan Inc.) in a temperature range of −50° C. to 50° C. (after rapid cooling in the apparatus, second heating is performed under the same conditions), using a Tzero Pan (made of aluminum) as a sample container, at a heating rate of 10° C. / min, in a nitrogen atmosphere (50 ml / min).

[0032] (Adhesive Layer) The adhesive layer 13 is provided on one main surface 12a of the undercoat layer 12. The adhesive layer 13 is formed by applying a resin (B) described below to one main surface 12a of the undercoat layer 12 and drying it. The shape of the adhesive portion 13 in a planar view is not particularly limited, and can be arbitrarily selected from a full-surface coating, a discontinuous body such as a circle, an ellipse, a square, a rectangle, a line, or other shape, and a continuous body such as a line, a lattice, or other shape.

[0033] The pressure-sensitive adhesive layer 13 is made of a resin (B) other than the resin used in the undercoat layer 12. The resin (B) is preferably a resin having a glass transition temperature of -80°C or higher and 0°C or lower. A preferred example of a resin having a glass transition temperature of -80°C or higher and 0°C or lower is an aqueous acrylic resin. An example of an aqueous acrylic resin is vinyl acetate.

[0034] The glass transition temperature of resin (B) is a value measured by the same method as that for the glass transition temperature of resin (A).

[0035] The pressure-sensitive adhesive layer 13 is mainly composed of the resin (B), but may contain inorganic components as long as the effects of the present invention are not impaired. Examples of inorganic components include inorganic additives contained in general pressure-sensitive adhesives.

[0036] (Release Paper) The release paper 14 is provided on the pressure-sensitive adhesive layer 13, i.e., on the surface 13c of the pressure-sensitive adhesive layer 13 opposite the undercoat layer 12. The release paper 14 is not particularly limited, and any known release sheet can be used. Examples include polyester film, polyethylene film, polypropylene film, polyimide film, release paper, polyether ether ketone (PEEK), polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamideimide (PAI), polyethersulfone (PES), etc., and films thereof that have been subjected to a release treatment, etc., and among these, release paper is preferred in terms of its resistance to huddling and low cost.

[0037] The thickness of the release paper 14 is not particularly limited, but is preferably 50 μm or more and 150 μm or less, and more preferably 60 μm or more and 120 μm or less.

[0038] (Sealing material) The thickness of the sealing material 10, i.e., the thickness of the laminate consisting of the fiber substrate 11, the undercoat layer 12, and the adhesive layer 13, is 2 mm or more and 15 mm or less, and preferably 5 mm or more and 12 mm or less. If the thickness of the sealing material 10 is less than the lower limit, it will not exhibit sufficient cushioning properties as a sealing material and will not be able to adequately conform to the unevenness of the surface of other components. If the thickness of the sealing material 10 exceeds the upper limit, the sealing material 10 will be too thick, making it difficult to handle when used as a sealing material, and will also lead to higher raw material costs, thereby impairing productivity.

[0039] In the seal material 10, the organic content in a layer 1 mm from the surface of the adhesive layer 13 side of the seal material 10 (in FIG. 1, the surface 13 a of the adhesive layer 13 opposite to the undercoat layer 12) excluding the adhesive layer 13 is defined as X １mg, and the organic content in the entire remaining portion of the surface of the sealing material 10 on the adhesive layer 13 side (in FIG. 1, the surface 13a of the adhesive layer 13 opposite to the undercoat layer 12) excluding the adhesive layer 13 and a layer 1 mm below it is X. ２ When expressed as mg, X ２ <X １ The organic content X satisfies the above. １ is the content of organic components in the sealing material 10 relative to the total mass of a layer 1 mm from the surface of the sealing material 10 on the adhesive layer 13 side, excluding the adhesive layer 13. ２ is the content of organic components in the sealing material 10 relative to the total mass of all the remaining parts of the sealing material 10 excluding the adhesive layer 13 and the 1 mm layer from the surface of the sealing material 10 on the adhesive layer 13 side. ２ <X １ If this condition is not satisfied, the resin contained in the fiber substrate 11 will not be distributed sufficiently unevenly on the surface of the fiber substrate 11 facing the adhesive layer 13, which will reduce the cushioning properties of the fiber substrate 11 and at the same time impair the strength of the substrate on the surface facing the adhesive layer 13.

[0040] The organic content X in a layer 1 mm from the surface of the adhesive layer 13 side of the sealing material 10 (in FIG. 1, the surface 13 a of the adhesive layer 13 opposite to the undercoat layer 12) excluding the adhesive layer 13 １ mg, and the organic content X in the entire remaining portion of the surface of the sealing material 10 on the adhesive layer 13 side (in FIG. 1, the surface 13a of the adhesive layer 13 opposite the undercoat layer 12) excluding the adhesive layer 13 and a layer 1 mm below it. ２ The method for measuring mg is to measure the loss on ignition, thereby obtaining the amount of organic components in a sample of the sealing material.

[0041] (Manufacturing Method) The manufacturing method of the sealing material 10 of this embodiment includes, for example, a step of applying the above-mentioned resin (A) to the entire surface of one main surface 11a of the fiber base 11 and drying to form the undercoat layer 12 (undercoat layer forming step), a step of applying the above-mentioned resin (B) to one main surface 12a of the undercoat layer 12 and drying to form the adhesive layer 13 (adhesive layer forming step), and a step of laminating the release paper 14 on the adhesive layer 13 (i.e., on the surface 13a of the adhesive layer 13 opposite the undercoat layer 12) (lamination step).

[0042] In the pressure-sensitive adhesive layer forming step, the means for forming the pressure-sensitive adhesive layer is not particularly limited, and known means such as a method using a coating plate, gravure coating, or transferring a pressure-sensitive adhesive sheet can be used.

[0043] According to the sealing material 10 of this embodiment, the fiber substrate 11 is made of inorganic fibers, the undercoat layer 12 is made of a resin (A) having a glass transition temperature of 25° C. or higher, the adhesive layer 13 is made of a resin (B) other than the resin used in the undercoat layer 12, the thickness of the sealing material 10 is 2 mm or more and 15 mm or less, and the organic content in a layer 1 mm from the surface of the adhesive layer 13 side of the sealing material 10 (in FIG. 1, the surface 13 a of the adhesive layer 13 opposite to the undercoat layer 12) excluding the adhesive layer 13 is X １ mg, and the organic content in the entire remaining portion of the surface of the sealing material 10 on the adhesive layer 13 side (in FIG. 1, the surface 13a of the adhesive layer 13 opposite to the undercoat layer 12) excluding the adhesive layer 13 and a layer 1 mm below it is X. ２ When expressed as mg, X ２ <X １ Therefore, the sealing material 10 has excellent strength of the fiber substrate 11 and excellent cushioning properties as a whole.

[0044] The present invention is not limited to the above-described embodiment.

[0045] The present invention will be described in more detail below, but is not limited to the following. Using the fiber substrate (I) described below, sealing materials were prepared according to the sealing material preparation method described below, with the thickness, layer structure, and organic content shown in Table 1. The obtained sealing materials were evaluated as follows.

[0046] <Evaluation of cushioning (conformity)> The compressive elastic modulus of the sealing material was determined by the following procedure, and the cushioning properties were evaluated based on this value. A 20 mm x 20 mm fiber substrate sample with an undercoat layer provided on one main surface was prepared. A compressive load was applied to the entire surface of the fiber substrate sample, and the application of the compressive load was stopped when a repulsive force of 0.5 kgf was generated. The displacement (mm) at the stop position was determined, and the elastic modulus was calculated from the displacement, stress, and area values, and evaluated as cushioning properties. Regarding the elastic modulus E (kPa) value, when E≦50, it was rated as "A," when 50<E≦75, it was rated as "B," and when 75<E, it was rated as "C."

[0047] <Evaluation of Surface Strength> A 50 mm x 60 mm fiber substrate sample having an undercoat layer on one main surface was prepared. An adhesive tape (Okamoto Tape No. 411N) was attached to the entire surface of the fiber substrate sample, and a 12.5 g / cm ２ A load of 10 ...

[0048] <Evaluation of productivity / workability> The workability of the sealant during installation was evaluated. Specifically, the temporary fastening function when attaching the sealant to the installation surface during installation was evaluated. The evaluation criteria were "A" if the sealant could be temporarily fastened to the installation surface without being pressed against it and there were no problems such as the sealant falling off during installation, "B" if the sealant could be temporarily fastened by pressing it against the installation surface and there were no problems such as the sealant falling off during installation, and "C" if the temporary fastening was insufficient and the sealant fell off during installation.

[0049] <Measurement of Organic Content> A crucible was prepared and heated in a heating furnace at 120°C for 15 minutes or more to obtain bone-dry crucible A, and the mass of crucible A was measured. A sample was placed in crucible A, and the crucible was again heated in a heating furnace to bone-dry under the same conditions. The combined mass of crucible A and the sample after drying (hereinafter referred to as crucible A containing sample) was measured, and the mass of crucible A was subtracted from the obtained value to obtain the mass of dried sample B. Crucible A containing sample was heated at 600°C for 20 minutes or more, and the mass of crucible A containing sample after heating was measured. The mass C of the organic components in the sample was obtained by subtracting the mass of crucible A containing sample after heating from the mass of crucible A containing sample before heating. The above operation was carried out on a 1 mm layer from the surface of the undercoat layer side excluding the adhesive layer of the sealing material, and on all remaining layers excluding the 1 mm layer from the surface of the undercoat layer side excluding the adhesive layer of the sealing material, using samples each having a size of 10 mm x 10 mm on the main surface, and the mass C of the organic component of the former was calculated as X １ , the mass C of the latter organic component is X ２ The relationship between these values ​​was examined, and the results were obtained as organic content.

[0050] <Overall Evaluation> Based on the evaluation results of cushioning (conformity), surface strength, and productivity / workability, an overall evaluation was performed using the following evaluation criteria. A: All three evaluation items were evaluated as "A." B: All three evaluation items were evaluated as "A" or "B," and one or more evaluation items were evaluated as "B." C: One or more evaluation items were evaluated as "C." The example with the best overall evaluation was labeled "Best" in Table 1. Furthermore, sealants were prepared by maintaining the sealant thickness, layer structure, and organic content of the Best example, while adjusting the thickness and density of the fiber substrate, the Tg and aqueous nature of the undercoat layer, and the material, Tg, type, and aqueous nature of the pressure-sensitive adhesive layer as shown in Table 2. Each sealant was evaluated for cushioning (conformity), surface strength, and productivity / workability. The results are shown in Table 2.

[0051] "Preparation of Fiber Substrate" <Preparation of Fiber Substrate (I)> 91.5 parts by mass of rock wool fiber (manufactured by Pacific Materials Corporation, product name "Pacific Mineral Fiber Granular Cotton") having an average fiber diameter of 3 μm to 6 μm as inorganic fiber, 0.5 parts by mass of colloidal silica (manufactured by Nissan Chemical Industries, Ltd., product name "Snowtex 0") having an average particle diameter of 12 μm as inorganic binder, 6 parts by mass of acrylic emulsion (manufactured by Nippon Zeon Corporation, product name "Nipol Lx852") as organic binder, and 0.5 parts by mass of polyacrylamide (manufactured by Arakawa Chemical Industries, Ltd., product name "Polystron 117") as internal paper strength enhancer were dispersed and mixed in water, and then 1.5 parts by mass of styrene-based resin (manufactured by Meisei Chemical Industry Co., Ltd., product name "Cerafix ST") as a polymer flocculant were added to obtain a papermaking slurry. The papermaking slurry was wet-formed using a square hand-made sheet machine and dried at 150°C. A predetermined amount of synthetic resin emulsion (manufactured by Showa Denko K.K., trade name "Polysol AG-101") as resin (A) having a glass transition temperature of 25°C or higher was dropped onto one of the main surfaces to a coating amount of 15 g / m ２ After lamination, the laminate was placed in an oven at 150°C for 20 minutes to dry, forming an undercoat layer and a basis weight of 2000 g / m ２ A sheet-like fiber substrate (I) having a thickness of 10 mm, a width of 250 mm, and a length of 250 mm was obtained. The basis weight of the organic components (organic binder, internal paper strength enhancer, polymer flocculant) contained in the fiber substrate (I) was 160 g / m ２ , the basis weight of the inorganic components (inorganic fibers, inorganic binder) is 1840 g / m ２ The density of the fiber substrate was adjusted by adjusting the amount of the polymer flocculant, and the thickness of the fiber substrate was adjusted by adjusting conditions such as pressure during drying, to obtain fiber substrates with the density and thickness of each Example and Comparative Example. Furthermore, resins with various glass transition temperatures, aqueous and non-aqueous resins were used for the undercoat layer to form undercoat layers corresponding to each Example and Comparative Example.

[0052] (Method of producing a sealing material) A coated plate is placed on one main surface of the undercoat layer of the fiber substrate (I), and a predetermined amount of an aqueous acrylic emulsion as a resin (B) other than the resin used in the undercoat layer is dropped onto the coated plate. Excess adhesive is scraped off with a squeegee to leave a coating amount of 100 g / m. ２ The adhesive was applied to one main surface of the undercoat layer so that the adhesive layer was 10 mm thick. After coating, the adhesive layer was placed in a 120°C oven for 10 minutes to dry, forming an adhesive layer. A release paper was then attached to the adhesive layer to obtain a 10 mm-thick sealant. Resins (B) with various glass transition temperatures, as well as aqueous and non-aqueous resins, were used to form adhesive layers corresponding to each Example and Comparative Example. The resulting sealants were subjected to the various evaluations described above. The results are shown in Tables 1 and 2. Furthermore, in the sealant, the thicknesses of the undercoat layer and adhesive layer relative to the thickness of the fiber substrate (I) were very small, and did not affect the cushioning properties of the sealant. Therefore, the thicknesses of the sealant listed in Tables 1 and 2 do not need to take into account the undercoat layer and adhesive layer. Therefore, the thicknesses of the sealant are listed as the same values ​​as the thickness of the fiber substrate, and these values ​​(mm) are rounded to one decimal place.

[0053]

[0054]

[0055] As is clear from the results in Tables 1 and 2, when all of the following conditions are met, the sealing material was excellent in overall cushioning (conformity), surface strength, and productivity (overall evaluation: A or B): When the thickness of the sealing material is 2 mm or more and 15 mm or less, When the organic content is X ２ <X １ - When a three-layer structure of adhesive layer (Ad) / undercoat layer (Uc) / fiber substrate (B) is adopted; - When the glass transition temperature of the resin of the undercoat layer is 25°C or higher; and - When the resin constituting the adhesive layer is different from the resin constituting the undercoat layer.

[0056] Furthermore, in addition to the above conditions, when one or more of the following conditions are satisfied, the sealing material tends to have excellent overall cushioning (conformity), surface strength, and / or productivity and workability (each evaluation is roughly A or B): - The resin (A) constituting the undercoat layer is aqueous, - The glass transition temperature of the resin (B) constituting the pressure-sensitive adhesive layer is -80°C or higher and 0°C or lower, - The resin (B) constituting the pressure-sensitive adhesive layer is an aqueous acrylic resin, - The density of the fiber substrate is 160 kg / m ３ Above, 250kg / m ３ If:

[0057] According to the present invention, it is possible to provide a sealing material that is excellent in strength of the fiber substrate and in overall cushioning properties.

[0058] REFERENCE SIGNS LIST 10 Sealing material 11 Fiber substrate 12 Undercoat layer 13 Pressure-sensitive adhesive layer 14 Release paper

Claims

1. A sealing material comprising a fiber substrate, an undercoat layer provided on one main surface of the fiber substrate, and an adhesive layer provided on the undercoat layer, wherein the fiber substrate is made of inorganic fibers, the undercoat layer is made of a resin (A) having a glass transition temperature of 25° C. or higher, the adhesive layer is made of a resin (B) other than the resin used in the undercoat layer, the thickness of the sealing material is 2 mm or more and 15 mm or less, and the organic content in a layer 1 mm from the surface of the sealing material on the adhesive layer side excluding the adhesive layer is X １ mg, and the organic content in the entire remaining portion of the surface of the sealing material on the adhesive layer side excluding the adhesive layer and a layer 1 mm below it is represented by X ２ When it is expressed as mg, X ２ <X １ A sealing material that satisfies the above requirements.

2. The sealing material according to claim 1, wherein the resin (A) is a water-based resin.

3. The sealing material according to claim 1, wherein the resin (B) has a glass transition temperature of -80°C or higher and 0°C or lower.

4. The sealing material according to claim 1, wherein the resin (B) is a water-based acrylic resin.

5. The density of the fiber substrate is 160 kg / m ３ Above, 250kg / m ３ The sealing material according to claim 1 , wherein:

6. The sealing material according to claim 1, wherein the thickness of the fiber substrate is 2 mm or more and less than 15 mm.

7. The sealing material according to claim 1, further comprising a release paper provided on said adhesive layer.

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