Flooring

Abstract

To provide a floor material which has an excellent sound proof property in which a reduction amount of a heavy floor impact sound level is equal to or greater than ΔLH-3 which is measured by using a standard impact source (tire impact source of impact characteristic (1)=bang machine) according to JIS A 1440-2.SOLUTION: A floor material is obtained by laminating a cushion sheet whose compressive elasticity modulus is 1.0-7.0 MPa on a lower surface of a tabular core material whose bending elasticity modulus is 500-9,000 MPa. In the tabular core material, a mean value of an aspect ratio of internally present cells is 1.1-4.0, and a polyolefin resin sheet whose tensile elasticity modulus is equal to or greater than 5 GPa is laminated at least on one surface of a polyolefin resin foam sheet whose expansion ratio is 3-20 times. In the floor material, a reduction amount of a heavy floor impact sound level is equal to or greater than ΔLH-3 which is measured by using a standard impact source (tire impact source of impact characteristic (1)=bang machine) according to JIS A 1440-2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flooring material having excellent soundproofing properties and capable of reducing heavy floor impact sound levels. [Background technology]

[0002] Conventionally, floors in houses have generally been formed by laying tatami mats or flooring materials on top of floor surfaces such as concrete, mortar, wood, or plywood. However, there has been a problem in that sounds generated on the upper floors echo to the floors below, causing noise problems.

[0003] Various means for preventing this noise have been proposed. For example, there is a "flooring material formed by bonding and fixing a cushioning material to the bottom of the flooring material, and then laying and fixing the material to the surface to be laid using an adhesive" (see, for example, Patent Document 1), "wooden flooring material and a slab with a density of 0.15 to 0.2 g / cm 3 , basis weight 450~550g / m 2 "(See, for example, Patent Document 2) and the like have been proposed for use as flooring materials.

[0004] However, low frequency sounds such as the sound of a heavy object falling are difficult to prevent, i.e. the amount of reduction in impact sound levels is small, and there has been a demand for flooring materials with better soundproofing properties that can reduce heavy floor impact sound levels more. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-206618 A [Patent Document 2] JP 2004-244972 A Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above problems, the object of the present invention is to provide a flooring material with excellent soundproofing properties, which has a reduction in heavy floor impact sound level of ΔLH-3 or more, measured using a standard impact source (tire impact source with impact force characteristics (1) = bang machine) based on JIS A 1440-2. [Means for solving the problem]

[0007] That is, the present invention provides: [1] A flooring material comprising a cushion sheet having a compressive modulus of 1.0-7.0 MPa laminated on the underside of a plate-shaped core material having a bending modulus of 500-9000 MPa, the plate-shaped core material comprising a polyolefin resin sheet having a tensile modulus of 5 GPa or more laminated on at least one side of a polyolefin resin closed-cell foam sheet having an average aspect ratio of the internal cells [Dz (maximum diameter of the cell in the thickness direction of the sheet) / Dxy (maximum diameter of the cell in the width direction or length direction of the sheet)] of 1.1-4.0 and an expansion ratio of 3-20 times, the flooring material being characterized in that the reduction in the heavy-duty floor impact sound level measured using a standard impact source (tire impact source of impact force characteristics (1) = bang machine) in accordance with JIS A 1440-2 is ΔLH-3 or more. [2] The flooring material according to the above [1], wherein the cushion sheet is a nonwoven fiber sheet in which non-moisture heat adhesive fibers are partially fused with a moisture heat adhesive resin. [3] The flooring material according to [1] or [2] above, characterized in that a decorative sheet is laminated on the upper surface of the plate-shaped core material. [4] The flooring material according to [1], [2] or [3], characterized in that a second plate-shaped core material is laminated on the underside of the cushion sheet. [5] The flooring material according to [4] above, characterized in that the second plate-shaped core material has a flexural modulus of 500 to 9000 MPa. [6] The flooring material according to any one of [1] to [5] above, characterized in that the surface hardness measured in accordance with the floor hardness test of JIS A 5917 (2018) is 50 G or less; and [7] The flooring material according to any one of [1] to [6] above, characterized in that the difference between the surface hardness measured in accordance with the JIS A 5917 (2018) floor hardness test and the surface hardness measured in accordance with the JIS A 6519 (2013) floor hardness test is 10 G or less. Regarding. Effect of the Invention

[0008] The present invention has the above-mentioned configuration, and has excellent soundproofing properties, with a reduction in heavy floor impact sound level of ΔLH-3 or more, measured using a standard impact source (a tire impact source of impact force characteristics (1) = bang machine) based on JIS A 1440-2. Therefore, it has an excellent effect of soundproofing noises such as audio equipment, pet cries, door opening and closing, and talking, and in particular, low-frequency sounds such as walking sounds on upper floors and heavy objects falling, and can reduce noise troubles. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the flooring material of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view showing another example of the flooring material of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The flooring material of the present invention is a flooring material comprising a cushion sheet having a compressive modulus of 1.0 to 7.0 MPa laminated on the underside of a plate-shaped core material having a flexural modulus of 500 to 9000 MPa, the plate-shaped core material comprising a polyolefin resin closed-cell foam sheet having an average aspect ratio of the internal cells [Dz (maximum diameter parallel to the sheet thickness direction) / Dxy (maximum diameter parallel to the sheet width or length direction)] of 1.1 to 4.0 and an expansion ratio of 3 to 20 times, the plate-shaped core material comprising a polyolefin resin sheet having a tensile modulus of 5 GPa or more laminated on at least one side thereof, the flooring material being characterized in that the reduction in heavy-duty floor impact sound level measured in accordance with JIS A 1440-2 using a standard impact source (tire impact source for impact force characteristics (1) = bang machine) is ΔLH-3 or more.

[0011] Next, the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing an example of the flooring material of the present invention. In the drawing, 1 is a plate-shaped core material, and the plate-shaped core material 1 is formed by laminating polyolefin-based resin sheets 12, 12 on both sides of a polyolefin-based resin closed-cell foam sheet 11, and a cushion sheet 2 is laminated on the lower surface of the plate-shaped core material 1.

[0012] The flooring material of the present invention is formed by laminating a cushion sheet 2 on the lower surface of a plate-shaped core material 1, and the plate-shaped core material 1 is used to impart mechanical strength to the flooring material and has a flexural modulus of 500 to 9000 MPa. If the flexural modulus is small, an impact applied locally to the plate-shaped core material 2 is directly transmitted locally to the cushion sheet 2 and does not spread to the entire flooring material, resulting in a decrease in soundproofing effect. Therefore, the flexural modulus is 500 to 9000 MPa, preferably 700 to 5500 MPa, more preferably 1000 to 4000 MPa, and even more preferably 2000 to 3600 MPa. In the present invention, the flexural modulus is measured in accordance with JIS K 7171.

[0013] The plate-like core material 1 is formed by laminating, on at least one side of a polyolefin resin closed-cell foam sheet 11 having an average cell aspect ratio [Dz (maximum diameter parallel to the sheet thickness direction) / Dxy (maximum diameter parallel to the sheet width or length direction)] of 1.1 to 4.0 and an expansion ratio of 3 to 20, a polyolefin resin sheet 12 having a tensile modulus of elasticity of 5 GPa or more.

[0014] The polyolefin resin closed-cell foam sheet 11 is a closed-cell foam sheet made of a polyolefin resin. Excellent closed cell property means that many of the cells present in the foam sheet are closed, and since a low closed cell rate makes the foam sheet soft and reduces its mechanical strength, the closed cell rate is preferably 60% or more, and more preferably 80% or more.

[0015] Examples of the polyolefin resin include high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, etc., and high-density polyethylene resin and polypropylene resin are preferred. Two or more types may be blended.

[0016] Furthermore, additives that have been generally used in the past when molding polyolefin-based resins, such as heat stabilizers, heat resistance improvers, light stabilizers, ultraviolet absorbers, antioxidants, impact modifiers, antifogging agents, antistatic agents, flame retardants, colorants, and pigments, may be added to the above-mentioned polyolefin-based resins as necessary.

[0017] The foam sheet 11 has spindle-shaped cells therein, and the average aspect ratio of the cells is 1.1 to 4.0. If the average aspect ratio is small, the shape of the cells becomes almost spherical, and the effect of improving the compressive strength (compressive elastic modulus) due to the shape of the cells decreases, and creep resistance and elastic recovery force decrease. Conversely, if the average aspect ratio is too large, the compressive strength (compressive elastic modulus) of the foam sheet becomes too high, vibration absorption decreases, and high stress is required against distortion, so the aspect ratio is 1.1 to 4.0, and preferably 1.3 to 2.5.

[0018] In the present invention, the aspect ratio is measured as follows. First, the foam sheet is cut in the thickness direction (z direction) of the sheet, and a 10x magnified photograph of the cut surface is taken. The maximum diameters of at least 50 randomly selected cells are measured in the thickness direction (z direction) and in the width direction or length direction (xy direction) of the sheet, and the average value is calculated. Next, the aspect ratio is calculated using the following formula. Aspect ratio = Dz (average maximum cell diameter in the thickness direction of the sheet) / Dxy (average maximum cell diameter in the width or length direction of the sheet)

[0019] Furthermore, if the expansion ratio of the foam sheet 11 is small, it becomes hard and the compression strength (compressive elastic modulus) becomes too high, and conversely, if it is large, the thickness of the cell walls becomes thin and the compression strength (compressive elastic modulus) becomes small, and when a heavy object is placed on the foam sheet 11 or when an impact is applied, it becomes prone to sagging, dents, etc., or to breakage, so the expansion ratio is 3 to 20 times, and preferably 5 to 15 times.

[0020] In the present invention, the bulk density of the foam sheet is measured in accordance with JIS K-6767 "Testing methods for polyethylene foams", and the reciprocal of the bulk density is taken as the expansion ratio.

[0021] The polyolefin resin sheet 12 is a resin sheet made of a polyolefin resin having a tensile modulus of elasticity of 5 GPa or more.

[0022] The polyolefin resin sheet 12 is laminated on at least one side of the polyolefin resin closed-cell foam sheet 11, and is a sheet that imparts mechanical strength to the laminated plate-like core material, so it is preferably laminated on both sides of the polyolefin resin closed-cell foam sheet 11. The polyolefin resin sheet is a sheet that imparts mechanical strength such as bending rigidity and impact resistance to the polyolefin resin closed-cell foam sheet, so the higher the mechanical strength, the more preferable it is, and the tensile modulus is 5 GPa or more. However, if it is too high, the rigidity becomes too large, and the soundproofing effect against impact sound when an impact is applied decreases, so 50 GPa or less is preferable.

[0023] The polyolefin resin sheet 12 may be uniaxially or biaxially stretched. The stretching ratio may be set so that the tensile modulus is 5 GPa or more, and is generally 10 times or more, and preferably 10 to 40 times.

[0024] Examples of the polyolefin resin constituting the polyolefin resin sheet 12 include high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, polypropylene resin, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-pentene copolymer, ethylene-1-hexene copolymer, etc., and high-density polyethylene resin and polypropylene resin are preferred. Two or more types may be used in combination.

[0025] Furthermore, additives that have been generally used in the past when molding polyolefin-based resins, such as heat stabilizers, heat resistance improvers, light stabilizers, ultraviolet absorbers, antioxidants, impact modifiers, antifogging agents, antistatic agents, flame retardants, colorants, and pigments, may be added to the above-mentioned polyolefin-based resins as necessary.

[0026] It is preferable that the polyolefin resins constituting the polyolefin resin closed-cell foam sheet 11 and the polyolefin resin sheet 12 are the same or similar so that the adhesion between the polyolefin resin closed-cell foam sheet and the polyolefin resin sheet is excellent.

[0027] The thickness of the polyolefin resin closed-cell foam sheet 11 is not particularly limited, but since a thinner polyolefin resin closed-cell foam sheet 11 reduces soundproofing properties, and a thicker polyolefin resin closed-cell foam sheet 11 reduces mechanical strength, the thickness is preferably 1 to 30 mm, and more preferably 2 to 9 mm.

[0028] The thickness of the polyolefin resin sheet 12 is not particularly limited, but if it is too thin, the mechanical strength will be low and it will be easily broken when an impact is applied, and conversely, if it is too thick, the bending rigidity will be too high, making it difficult to bend and reducing the soundproofing effect against impact noise when an impact is applied. Therefore, the thickness is preferably 20 to 1,000 μm, and more preferably 40 to 100 μm.

[0029] The thickness of the plate-shaped core material 1 is not particularly limited, but if it is too thin the flooring material will lack mechanical strength, and if it is too thick it will be heavy, so the thickness is preferably 1 to 10 mm, and more preferably 2 to 9 mm.

[0030] The method for producing the above-mentioned plate-shaped core material is not particularly limited, and any conventionally known manufacturing method may be adopted. For example, a method in which the above-mentioned polyolefin-based resin closed-cell foam sheet and polyolefin-based resin sheet are separately produced, and then the two are adhesively bonded together with an adhesive, or a method in which the two are heat-sealed, may be mentioned.

[0031] Other examples of different methods for producing a plate-shaped core material include a method in which a foamable resin composition consisting of a polyolefin resin, a crosslinking agent and a thermally decomposable foaming agent is heated and melt-extruded to produce a foamable resin sheet, the resulting foamable resin sheet is sandwiched between two polyolefin resin sheets and fusion-laminated, and then further heated to foam; a method in which a foamable resin composition consisting of a polyolefin resin and a thermally decomposable foaming agent is heated and melt-extruded onto a polyolefin resin sheet to form a foamable resin sheet that is fusion-laminated, and then the crosslinked foamable resin sheet obtained by crosslinking the composition by exposure to ionizing radiation is heated and melted to foam.

[0032] By the above-mentioned manufacturing method, a plate-shaped core material can be easily obtained in which a polyolefin resin sheet is laminated on at least one side of a polyolefin resin closed-cell foam sheet, and the average aspect ratio of the internal cells [Dz (maximum diameter parallel to the sheet thickness direction) / Dxy (maximum diameter parallel to the sheet width or length direction)] is 1.1 to 4.0.

[0033] The cushion sheet 2 imparts cushioning and soundproofing properties to the plate-shaped core material 1, and in particular, by being laminated on the underside of the plate-shaped core material 1, it contributes to the effect of reducing the heavy floor impact sound level, and its compressive elastic modulus is 1.0 to 7.0 MPa.

[0034] The compressive elastic modulus of the cushion sheet 2 is 1.0 to 7.0 MPa, preferably 1.5 to 3.0 MPa, since a smaller compressive elastic modulus makes the sheet more susceptible to sagging and reduces soundproofing properties, particularly the effect of reducing heavy floor impact sound levels, and a larger compressive elastic modulus reduces cushioning properties and impact mitigation properties.

[0035] In the present invention, the compressive elastic modulus is determined in accordance with JIS K 7181 (2011 Plastics - Determination of compression properties) by pressing a 50 mm x 50 mm square cushion sheet at a speed of 10 mm / min with a cylindrical indenter with a diameter of 50 mm and a flat bottom, and measuring the slope of the compression when the cushion sheet is distorted by 10% to 20%.

[0036] The apparent density of the cushion sheet 2 is set to 0.04 to 0.2 g / cm because a smaller apparent density leads to a decrease in cushioning properties and a tendency to collapse, and a larger apparent density leads to a decrease in soundproofing properties. 3 is preferable, and more preferably 0.04 to 0.12 g / cm 3 Furthermore, the thickness is preferably 2 to 20 mm, and more preferably 5 to 15 mm, since a thinner material reduces cushioning and soundproofing properties, and a thicker material is more likely to become worn out.

[0037] In addition, if the basis weight of the cushion sheet 2 is small, it becomes easy to collapse, and if it is large, the cushioning property and soundproofing property decrease. Therefore, the basis weight is 160 to 2000 g / m 2 is preferable, and more preferably 200 to 1800 g / m 2 , and more preferably 300 to 1500 g / m 2 It is.

[0038] The cushion sheet 2 is not particularly limited as long as it is a sheet having cushioning properties with a compressive elastic modulus of 1.0 to 7.0 MPa, and examples thereof include cushioning sheets that have traditionally been used as cushioning sheets for flooring materials, such as olefin resin foam sheets; rubber sheets; elastomer sheets; and woven fabrics, knitted fabrics, nonwoven fabrics, mats, felts, and other cushioning sheets made of organic fibers such as natural fibers and synthetic fibers or inorganic fibers.

[0039] As the cushion sheet 2, a nonwoven fiber sheet in which non-moisture heat adhesive fibers are partially fused with a moisture heat adhesive resin is preferably used since it has a low apparent density, an excellent compressive elastic modulus, and a high mechanical strength.

[0040] As the non-heat-adhesive fiber under moisture, general-purpose non-heat-adhesive fibers can be used, such as hemp fibers, cotton fibers, polyethylene fibers, polypropylene fibers, urethane fibers, polyacrylic fibers, polyester fibers, and polyamide fibers, with polyester fibers and polyamide fibers being preferred.

[0041] The above-mentioned heat-adhesive resin under moisture conditions is a thermoplastic resin capable of self-adhesive or adhering to the above-mentioned non-heat-adhesive fiber under high temperature and high humidity conditions, and examples thereof include ethylene-vinyl alcohol copolymers and polylactic acid resins.

[0042] In the above nonwoven fiber sheet, the non-thermal adhesive fibers are partially fused with a thermal adhesive resin under moisture, but it is preferable that the fused portions are uniformly distributed throughout the nonwoven fiber sheet so that the apparent density and mechanical strength of the entire nonwoven fiber sheet are uniform.

[0043] Therefore, it is preferable that the non-thermal adhesive fiber is partially fused with the thermal adhesive resin fiber made of the thermal adhesive resin under moisture. Also, the thermal adhesive resin fiber under moisture may be a core-sheath type fiber in which the surface of the non-thermal adhesive fiber is coated with the thermal adhesive resin under moisture.

[0044] The average fineness of the non-thermal adhesive fiber and the thermal adhesive resin fiber under moisture is preferably 0.1 to 30 dtex, more preferably 0.5 to 20 dtex, since a smaller average fineness leads to a decrease in cushioning properties and a tendency to become sagging, and a larger average fineness leads to a decrease in soundproofing properties. The cross-sectional shape is not particularly limited, and examples thereof include a circle, an ellipse, a polygon, and the like.

[0045] Furthermore, the length of the above non-thermal adhesive fibers and thermal adhesive resin fibers under moisture is generally 5 to 100 mm, preferably 10 to 80 mm, since a shorter length reduces mechanical strength and soundproofing properties, while a longer length makes production difficult.

[0046] The ratio of the non-thermal adhesive fiber and the thermal adhesive resin under moisture is not particularly limited, but is generally 50 to 200 parts by weight, and preferably 80 to 150 parts by weight, of the thermal adhesive resin under moisture to 100 parts by weight of the non-thermal adhesive fiber under moisture.

[0047] The method for producing the nonwoven fiber sheet is not particularly limited, but may be, for example, a method in which a sheet-like web is produced by mixing non-heat-adhesive fibers and heat-adhesive resin fibers under moisture, and the web obtained is sandwiched between a net and pressurized while being heated and humidified by spraying hot water or steam from above and below. The nonwoven fiber sheet produced by the above method is uniformly bonded throughout the sheet, and has excellent uniform mechanical strength (especially compressive modulus) throughout the sheet. When a web is produced using sheath-core fibers in which the surface of a non-heat-adhesive fiber is coated with a heat-adhesive resin under moisture, the web may be produced using only sheath-core fibers.

[0048] The cushion sheet 2 may be a laminated sheet in which two or more of the above-mentioned thin nonwoven fiber sheets are laminated, or in which two or more of the above-mentioned thin nonwoven fiber sheets having different densities or thicknesses are laminated, or in which one or more of the above-mentioned thin nonwoven fiber sheets and one or more of the above-mentioned thin cushioning sheets are laminated.

[0049] The cushion sheet 2 formed by laminating the nonwoven fiber sheet and the cushioning sheet has a compressive elastic modulus of 1.0 to 7.0 MPa as a whole sheet. The compressive elastic modulus of the cushioning sheet may deviate slightly from this range, but it is preferable that the compressive elastic modulus of the nonwoven fiber sheet is within this range.

[0050] When the cushion sheet 2 is formed by laminating the nonwoven fiber sheet and the cushioning sheet, the ratio of the thickness of the nonwoven fiber sheet to the thickness of the cushioning sheet is preferably 1:2 to 2:1.

[0051] Fig. 2 is a cross-sectional view showing another example of the flooring material of the present invention. In the figure, reference numeral 1 denotes a plate-shaped core material formed by laminating polyolefin resin sheets on both sides of a polyolefin resin closed-cell foam sheet, and a cushion sheet 2 and a second plate-shaped core material 3 are laminated in this order on the underside of the plate-shaped core material 1.

[0052] The second plate-shaped core material 3 is laminated on the lower surface of the cushion sheet 2 to protect the cushion sheet 2 and impart mechanical strength to the flooring material.

[0053] The second plate-shaped core material 3 is preferably a plate material with a higher bending modulus than the cushion sheet 2. If the bending modulus is small, an impact applied locally to the flooring material will be transmitted directly downward locally and not spread throughout the entire flooring material, resulting in a reduced soundproofing effect. Therefore, the bending modulus is preferably 500 to 9000 MPa, more preferably 1000 to 5000 MPa, and even more preferably 1500 to 4000 MPa.

[0054] Furthermore, as the second plate-shaped core material 3, plate materials that have traditionally been used as plate-shaped core materials for flooring materials can also be used, such as wood-based plate materials used as plate-shaped core materials for flooring materials, wood-based plate materials that have been given rigidity by laminating aluminum sheets, aluminum foil, etc. on both sides of the plate material, closed-cell olefin-based synthetic resin foam sheets with high-rigidity sheets laminated on both sides, high-beam boards, aluminum plywood, wood flooring, cork boards, etc.

[0055] The board material is preferably a wood-based board material having high mechanical strength such as bending strength and bending elasticity modulus. As the wood-based board material, a wood fiberboard made by pulping lumber or other plant fibers, binding them with a binder resin, and hot-pressing them into a board is preferred. Examples of such board materials include particle board, plywood, insulation fiberboard (insulation board), medium density fiberboard (MDF), hard fiberboard (hardboard), etc., with medium density fiberboard (MDF) being particularly preferred.

[0056] The second plate-shaped core material 3 has a reduced mechanical strength if it is too thin, and is heavy if it is too thick, so the thickness is preferably 2 to 30 mm, and more preferably 3 to 7 mm.

[0057] Since the surface of the plate-shaped core material 1 is the surface of the flooring material on which people sit and walk, a decorative sheet for imparting flexibility, cushioning, heat retention, decorativeness, etc. may be laminated on the upper surface of the plate-shaped core material 1. Examples of decorative sheets include carpets, rugs, cushion flooring, synthetic resin foam sheets, flooring, P-tiles, tatami mats, etc.

[0058] When a decorative sheet is laminated on the top surface of the plate-shaped core material 1, a second cushion sheet may be laminated between the plate-shaped core material 1 and the decorative sheet to impart cushioning and soundproofing to the flooring material. The second cushion sheet imparts cushioning, soundproofing, and functionality to the flooring material, and is not particularly limited as long as it is a sheet that has been conventionally used as a cushion sheet for flooring materials, and examples thereof include nonwoven fabrics, woven fabrics, mats, and felts made of fibers such as hemp fibers, cotton fibers, polyethylene fibers, polypropylene fibers, urethane fibers, polyacrylic fibers, and polyester fibers; foam sheets such as polystyrene resin foam sheets, polyethylene resin foam sheets, polypropylene resin foam sheets, urethane foam sheets, and rubber foam sheets; and cushioning sheets such as kraft paper, paperboard, thick paper, and cardboard, and functionality can be added by adding moisture absorbents, anti-mite agents, anti-fungal agents, antibacterial agents, disinfectants, and fragrances.

[0059] The second cushion sheet is prone to collapse and its cushioning properties decrease when its apparent density is small, while its sound absorption and soundproofing properties decrease when its apparent density is large. Therefore, the apparent density is set to 0.04 to 0.2 g / cm. 3 It is preferable that the nonwoven fabric is made of fibers such as hemp fibers, cotton fibers, polyethylene fibers, polypropylene fibers, urethane fibers, polyacrylic fibers, polyester fibers, or the like, and more preferable that the nonwoven fabric is made of polyester fibers.

[0060] The basis weight of the second cushion sheet is 50 to 3000 g / m because the cushioning effect decreases when it is small and the soundproofing effect decreases when it is large. 2 is preferable, and more preferably 150 to 500 g / m 2 It is.

[0061] The thickness of the second cushion sheet is generally 1 to 10 mm, and preferably 1.5 to 5 mm. The second cushion sheet may be formed by laminating two or more thin nonwoven fabrics. Furthermore, nonwoven fiber sheets having different densities or thicknesses may be laminated, or the nonwoven fiber sheet may be combined with a cushioning sheet.

[0062] Furthermore, a back surface finishing material may be laminated on the underside of the cushion sheet 2 or the second plate-shaped core material 3. The back surface finishing material is a sheet laminated on the underside of the cushion sheet 2 or the second plate-shaped core material 3 for the purpose of preventing slipping, reinforcing, waterproofing, etc. of the floor material.

[0063] Examples of back surface finishing materials for preventing slipping include anti-slip sheets made of resins having anti-slip properties such as silicone resins, acrylic resins, and acrylic silicone resins, anti-slip sheets on nonwoven fabrics, woven fabrics, mats, felts, etc. made of fibers such as hemp fibers, cotton fibers, polyethylene fibers, polypropylene fibers, urethane fibers, polyacrylic fibers, and polyester fibers, on which granular, linear, and lattice-shaped convex portions are formed, such as silicone resins, acrylic resins, and acrylic silicone resins, and foam sheets on which granular, linear, and lattice-shaped convex portions are formed on the back surface of polyethylene resins, polypropylene resins, polystyrene resins, etc. Examples of back surface finishing materials for reinforcement include craft paper, paperboard, thick paper, cardboard, chipboard, synthetic resin sheets, and cloth adhesive tape, and examples of back surface finishing materials for waterproofing include synthetic resin sheets such as polyethylene resins, polypropylene resins, and polystyrene resins.

[0064] The method for manufacturing the flooring material of the present invention is not particularly limited, and any conventionally known manufacturing method may be adopted. For example, a method of laminating a plate-shaped core material 1 and a cushion sheet 2, or a plate-shaped core material 1, a cushion sheet 2 and a second plate-shaped core material 3, and if necessary a second cushion sheet, a back surface finishing material, etc., and bonding them with, for example, a rubber-based, acrylic-based, urethane-based, silicone-based or other pressure-sensitive adhesive, a method of heat-sealing with a polyolefin-based hot melt adhesive such as ethylene-vinyl acetate copolymer or linear low density polyethylene resin, a method of sewing with thread, a method of nailing down with a stapler, etc.

[0065] It is preferable that the plate-shaped core material 1 or the second plate material 3 and the cushion sheet 2 are bonded with an adhesive so as not to move. Although it is sufficient that a part of the surface of the plate-shaped core material 1 or the second plate material 3 that contacts the cushion sheet 2 is bonded to the cushion sheet 2, it is preferable to bond the entire surface.

[0066] The flooring material of the present invention has the above-mentioned configuration, and although there are no particular limitations on its thickness, it is generally 8 to 35 mm since it is a flooring material.

[0067] The flooring material of the present invention has the above-mentioned structure, and the reduction in the heavy-duty floor impact sound level measured using a standard impact source (tire impact source of impact force characteristics (1) = bang machine) based on IS A 1440-2 is ΔLH-3 or more.

[0068] The surface hardness (hereinafter referred to as the "first G value") of the flooring material of the present invention measured in accordance with the floor hardness test of JIS A 5917 (2018) is preferably 50 G or less, and more preferably 37 G or less.

[0069] It is preferable that the difference between the surface hardness (1st G value) measured in accordance with the floor hardness test JIS A 5917 (2018) and the surface hardness (hereinafter referred to as the "2nd G value") measured in accordance with the floor hardness test JIS A 6519 (2013) is 10 G or less.

[0070] The first G value is the average value of the measurements taken in the third to fifth measurements out of five drop tests, and the second G value is the average value of the measurements taken in the first to fifth measurements out of five drop tests. Usually, when a drop test is repeated, the shock mitigation performance decreases, so the second G value becomes smaller than the first G value. Therefore, a small difference between the first G value and the second G value means that the shock mitigation performance is maintained even if the drop test is repeated, and the smaller this difference is, the more preferable, and it is more preferably 5G or less, and even more preferably 3G or less.

[0071] The flooring material of the present invention has the above-mentioned configuration, and by configuring this flooring material to a specific shape and size, it can also be used as a floor panel that can be installed in a specified position.

[0072] The flooring material of the present invention has a structure as described above, and has a soundproofing effect of reducing heavy floor impact sound levels by ΔLH-3 or more as measured using a standard impact source (tire impact source with impact force characteristics (1) = bang machine) based on IS A 1440-2, and is excellent in soundproofing the noise of audio equipment, pet cries, opening and closing doors, talking, etc., and in particular in soundproofing low-frequency sounds such as the sound of walking upstairs and the sound of heavy objects falling, thereby reducing noise troubles. EXAMPLES

[0073] Next, examples of the present invention will be described, but the present invention is not limited to these examples.

[0074] Example 1 Manufacturing of plate-shaped core material A resin composition consisting of 100 parts by weight of polypropylene resin, 15 parts by weight of azodicarbonamide, and 2 parts by weight of zinc stearate was hot-melt extruded at 170°C using an extruder, and the resulting molten resin sheet was laminated and adhered to a uniaxially oriented polypropylene resin film (thickness 40 μm, stretch ratio 10 times, tensile modulus 15 GPa), crosslinked by irradiating with 3 Mrad of ionizing electron beams, and then a uniaxially oriented polypropylene resin film (thickness 40 μm, stretch ratio 10 times, tensile modulus 15 GPa) was heat-sealed to the other side of the molten resin sheet to obtain a three-layered foamable sheet.

[0075] Next, the obtained foamable sheet was fed into a foaming chamber set at about 250°C to foam the molten resin sheet to obtain a plate-shaped core material. The thickness of the obtained plate-shaped core material was 6 mm, the foamed molten resin sheet (polypropylene resin closed cell foam sheet) had an expansion ratio of 10 times, a closed cell ratio of 90%, the shape of the cells was long in the thickness direction, and the aspect ratio was 2.4. The flexural modulus of the plate-shaped core material was 1900 MPa.

[0076] Manufacture of cushion sheets A carded web was produced by the carding method using core-sheath staple fibers (fineness 3.3 dtex, fiber length 51 mm, core to sheath weight ratio 1:1, number of crimps 21 / 25 mm, shrinkage rate 13.5%) in which the core was polyethylene terephthalate and the sheath was ethylene-vinyl alcohol copolymer (ethylene content 44 mol%, saponification degree 98.4 mol%).

[0077] The obtained card web was sandwiched between two wire belts, and pressure was applied while high-temperature steam at 0.25 MPa was sprayed from above and below to melt and bond the sheath portion (ethylene-vinyl alcohol copolymer) of the core-sheath staple fibers, obtaining a nonwoven fiber sheet with a thickness of 4 mm and an apparent density of 0.05 g / cm3.

[0078] Four of the nonwoven fiber sheets were stacked together to obtain a cushion sheet with a thickness of 16 mm. The compressive elastic modulus of the cushion sheet obtained was 1.05 MPa, and the basis weight was 800 g / m 2 It was.

[0079] As shown in FIG. 1, the obtained cushion sheet 2 was laminated on the lower surface of the obtained plate-shaped core material 1 having a thickness of 6 mm and a bending modulus of 1900 MPa to obtain a floor material having a thickness of 22 mm.

[0080] Example 2 Three nonwoven fiber sheets obtained in Example 1 were stacked to obtain a cushion sheet having a thickness of 12 mm. The compressive elastic modulus of the obtained cushion sheet was 1.66 MPa, and the basis weight was 600 g / m 2A flooring material having a thickness of 18 mm was obtained in the same manner as in Example 1, except that the obtained cushion sheet was used.

[0081] Example 3 Two nonwoven fiber sheets obtained in Example 1 were overlapped to obtain a cushion sheet having a thickness of 8 mm. The compressive elastic modulus of the obtained cushion sheet was 2.29 MPa, and the basis weight was 400 g / m 2 A flooring material having a thickness of 14 mm was obtained in the same manner as in Example 1, except that the obtained cushion sheet was used.

[0082] Example 4 As shown in Figure 2, a plate-shaped core material 2 obtained in Example 1 having a thickness of 6 mm, a bending modulus of elasticity of 1900 MPa and a bending strength of 40.9 MPa was laminated on the upper surface of the cushion sheet 1 obtained in Example 2 having a thickness of 12 mm, and the same plate-shaped core material was laminated on the lower surface as a second plate-shaped core material 3, to obtain a flooring material having a thickness of 24 mm.

[0083] Example 5 As shown in Figure 2, a plate-shaped core material 2 obtained in Example 1 having a thickness of 6 mm, a bending modulus of elasticity of 1900 MPa and a bending strength of 40.9 MPa was laminated on the upper surface of the 8 mm-thick cushion sheet obtained in Example 3, and the same plate-shaped core material was laminated on the lower surface as a second plate-shaped core material 3 to obtain a flooring material having a thickness of 20 mm.

[0084] The flooring materials obtained in Examples 1 to 5 were used as samples, and the reduction in the heavy floor impact sound level was measured using a standard impact source (tire impact source of impact force characteristics (1) = bang machine) based on JIS A 1440-2. In addition, the first G value was measured in accordance with the floor hardness test of JIS A 5917 (2018), and the second G value was measured in accordance with the floor hardness test of JIS A 6519 (2013). The reduction in the heavy floor impact sound level, the first G value, the second G value, and the difference between the first G value and the second G value are shown in Table 1 together with the composition of the flooring material. For reference, the standard values ​​of floor impact sound levels ΔLH-2 and ΔLH-3 are also shown.

[0085] [Table 1] [Industrial Applicability]

[0086] The flooring material of the present invention has excellent soundproofing properties, with a reduction in heavy floor impact sound levels of ΔLH-3 or more, measured using a standard impact source (a tire impact source of impact force characteristics (1) = bang machine) based on JIS A 1440-2, and is therefore effective in insulating noise from audio equipment, pets barking, door opening and closing, talking, etc., and is particularly effective in insulating low-frequency sounds such as the sound of walking on upper floors and the sound of heavy objects falling, thereby reducing noise troubles. Therefore, it can be suitably used in place of conventional flooring materials even in high-rise apartment complexes and condominiums. [Explanation of symbols]

[0087] 1 Plate-shaped core material 11 Polyolefin resin closed cell foam sheet 12 Polyolefin resin sheet 2 Cushion seat 3. Second plate-shaped core material

Claims

1. A flooring material comprising a cushion sheet having a compressive modulus of elasticity of 1.0 to 7.0 MPa laminated on the underside of a plate-shaped core material having a flexural modulus of elasticity of 500 to 9000 MPa, the plate-shaped core material comprising a polyolefin resin closed-cell foam sheet having an average aspect ratio of the internal cells [Dz (maximum diameter of the cell in the thickness direction of the sheet) / Dxy (maximum diameter of the cell in the width direction or length direction of the sheet)] of 1.1 to 4.0 and an expansion ratio of 3 to 20 times, and a polyolefin resin sheet having a tensile modulus of elasticity of 5 GPa or more laminated on at least one side of the plate-shaped core material, the weight floor impact sound level reduction amount measured using a standard impact source (tire impact source of impact force characteristic (1) = bang machine) in accordance with JIS A 1440-2 is ΔLH-3 or more, and a second plate material is laminated on the underside of the cushion sheet, the second plate material having a flexural modulus of elasticity of 500 to 9000 MPa.

2. 2. The flooring material according to claim 1, wherein the cushion sheet is a nonwoven fiber sheet in which non-moisture heat adhesive fibers are partially fused with a moisture heat adhesive resin.

3. 3. The flooring material according to claim 1, further comprising a decorative sheet laminated on the upper surface of the plate-like core material.

4. The flooring material according to any one of claims 1 to 3, characterized in that the surface hardness measured in accordance with the floor hardness test of JIS A 5917 (2018) is 50 G or less.

5. The flooring material according to any one of claims 1 to 4, characterized in that the difference between the surface hardness measured in accordance with the floor hardness test of JIS A 5917 (2018) and the surface hardness measured in accordance with the floor hardness test of JIS A 6519 (2013) is 10 G or less.

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