Method for manufacturing flooring materials, flooring materials, and construction methods for floor structures

Abstract

To improve workability of a floor structure while suppressing unevenness in floor materials and adhesive seeping out onto edge faces of the floor materials.SOLUTION: A manufacturing method of a floor material includes: a tongue portion forming step of forming a tongue portion by a tongue and groove joint working on a widthwise and / or lengthwise end faces of an intermediate product (10A); and a recessed step forming step of forming a recessed step (36) on both widthwise end sides of a back surface of a foamed resin layer (16) in the intermediate product (10A).SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a floor material, a floor material, and a method for constructing a floor structure.

Background Art

[0002] It is known to construct a floor structure (flooring) by sequentially directly pasting a plurality of rectangular floor materials such as those with a width of 300 mm and a length of 1,800 mm onto a floor base using an adhesive. Usually, adhesives such as epoxy resins, urethane resins, crosslinked vinyl acetate resins, and modified silicone resins are used as the adhesive. After applying the adhesive to the surface of the floor base or the back surface of the floor material, the floor material is placed on the surface side of the floor base material.

[0003] Rectangular floor materials may cause warping due to dimensional changes caused by temperature and moisture content variations. This warping may contribute to so-called upheavals occurring on the floor surface. By strengthening the adhesive force of the floor material to the floor base material, the warping of the floor material can be suppressed. However, firmly adhering and fixing all floor materials to the floor base material is not preferable from the perspective of the amount of adhesive used. Also, when constructing the floor structure, it is difficult to uniformly apply the adhesive to the surface of the floor base or the back surface of the floor material at the construction site. Variations occur in the adhesive force between the back surface of the floor material and the surface of the floor base material, and there may be locations where the warping of the floor material cannot be completely suppressed.

[0004] To suppress the warping of the floor material, a method has been proposed in which grooves are formed along the length direction on the back surface of the floor material, and the adhesive is applied using these grooves as guides (see Patent Documents 1-2). According to this method, the adhesive can be applied at a predetermined position without using an excessive amount of adhesive, and the floor material can be directly pasted onto the floor base material while suppressing deformations such as warping of the floor material.

[0005] On the other hand, in order to maintain the adhesive durability of the flooring material and the reliability of the construction of the floor structure, a method has been proposed in which a cut-off section (step) is provided on the widthwise edge side of the back surface of the flooring material, adhesive is applied to the cut-off section, and the flooring material is directly attached to the subfloor material using adhesive tape in combination with the adhesive (see Patent Document 3). With this method, the thickness of the adhesive is absorbed by the cut-off section, and the adhesive tape attached to the back surface of the flooring material can be easily and reliably adhered to the subfloor material. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2008-75330 [Patent Document 2] Utility Model Registration No. 3185185 (Gazette) [Patent Document 3] Japanese Utility Model Publication No. 52-20717 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the technologies described in Patent Documents 1-2 still had problems, such as unevenness in the flooring material occurring depending on the amount of adhesive applied, resulting in floor creaking, and adhesive seeping out onto the edges of the flooring material in the width direction.

[0008] Furthermore, in the technology described in Patent Document 3, since the flooring material is directly attached to the subfloor using both adhesive tape and adhesive, the adhesive tape adheres to the subfloor first, which worsens the workability when fitting (positioning) the actual parts of the flooring material, and there was room for improvement in the construction of the floor structure.

[0009] Therefore, one aspect of the present invention aims to improve the constructability of a floor structure while suppressing unevenness in the flooring material and the leakage of adhesive onto the edges of the flooring material. [Means for solving the problem]

[0010] In order to solve the aforementioned problems, the inventors of the present invention diligently studied a rectangular flooring material having a foamed resin layer and a non-foamed resin layer. As a result, they discovered that by forming recessed steps on both ends in the width direction of the back surface of the foamed resin layer and applying adhesive in a bead-like manner to these recessed steps, it is possible to improve the workability of the floor structure while suppressing unevenness in the flooring material, misalignment of adhesive application, and adhesive seepage to the edges of the flooring material in the width direction, thus completing the present invention. One aspect of the present invention is as follows.

[0011] [1] A method for manufacturing a rectangular flooring material having a foamed resin layer and a non-foamed resin layer laminated on the surface side of the foamed resin layer, comprising: a step of forming an intermediate product by bonding the surface of the foamed resin layer and the back surface of the non-foamed resin layer to form an intermediate product of the flooring material; a step of forming a solid part by forming a solid part on the end faces in the width direction and / or length direction of the intermediate product by solid processing; and a step of forming a recessed step, which forms recessed steps on both ends in the width direction on the back surface of the foamed resin layer of the intermediate product.

[0012] [2] The method for manufacturing the flooring material according to [1], wherein in the step of forming the recessed step, the width dimension of the recessed step is set to 20 mm to 40 mm, and the depth of the recess of the recessed step is set to 8% to 30% of the thickness of the central part in the width direction of the foamed resin layer.

[0013] [3] The method for manufacturing flooring material according to [1] or [2], wherein in the step of forming the recessed step, the recessed step is formed by compression molding both ends in the width direction of the foamed resin layer in the intermediate product.

[0014] [4] A method for manufacturing flooring material according to any of [1] to [3], wherein in the step of forming the recessed step portion, when performing actual processing on the end face of the intermediate product, the widthwise ends of the intermediate product are clamped by a pair of clamping members, thereby compressing and molding the widthwise ends of the foamed resin layer in the intermediate product to form the recessed step portion.

[0015] 〔5〕A floor material formed in a rectangular shape, having a foamed resin layer and a non-foamed resin layer laminated on the surface side of the foamed resin layer, with a real part formed at the end face in the width direction and / or the length direction, and concave stepped portions formed on both ends in the width direction of the back surface of the foamed resin layer, the floor material.

[0016] 〔6〕For the floor material of 〔5〕, the width dimension of the concave stepped portion is 20 mm to 40 mm, and the amount of indentation of the concave stepped portion is 8% to 30% with respect to the thickness of the central portion in the width direction of the foamed resin layer.

[0017] 〔7〕For the floor material of 〔5〕 or 〔6〕, the 10% compression strength of the foamed resin layer is 1.5 MPa or less.

[0018] 〔8〕A method for constructing a floor structure using the floor material of 〔5〕 for constructing a floor structure on a floor underlay material, including an application step of applying an adhesive in a bead shape to the concave stepped portion of the foamed resin layer in the floor material, and a direct bonding step of directly bonding a plurality of the floor materials to the floor underlay material by the bonding action of the adhesive while fitting the real parts of the adjacent floor materials in the width direction and / or the length direction.

[0019] 〔9〕In the application step of 〔8〕, the application width of the adhesive to the concave stepped portion of the foamed resin layer in the floor material is 15 mm to 35 mm.

[0020] 〔10〕In the direct bonding step of 〔8〕 or 〔9〕, the floor material is directly bonded to the floor underlay material only by the bonding action of the adhesive.

Advantages of the Invention

[0021] According to one aspect of the present invention, it is possible to improve the workability of the floor structure while suppressing the step of the floor material and the protrusion of the adhesive to the end face of the floor material.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic perspective view of the floor material according to an embodiment of the present invention as viewed from the back side. [Figure 2] This is a schematic perspective view of a flooring material according to an embodiment of the present invention, as seen from the surface side. [Figure 3] This is a schematic cross-sectional view of a floor structure according to an embodiment of the present invention. [Figure 4] This is a schematic partial cross-sectional view of a floor structure including the male and female parts formed by tongue and groove processing. [Figure 5] This is a schematic partial cross-sectional view of a floor structure including the male and female parts formed by tongue and groove processing. [Figure 6] This is a schematic partial cross-sectional view of a floor structure including male and female fruiting parts formed by interlocking joints. [Figure 7] This is a schematic cross-sectional view illustrating the intermediate product formation process in a method for manufacturing flooring materials according to an embodiment of the present invention. [Figure 8] This is a schematic cross-sectional view illustrating the process of forming the solid portion and the process of forming the recessed step portion in a method for manufacturing flooring material according to an embodiment of the present invention. [Figure 9] This is a schematic cross-sectional view showing a flooring material manufactured by a flooring material manufacturing method according to an embodiment of the present invention. [Figure 10] This is a schematic cross-sectional view illustrating a method for constructing a floor structure according to an embodiment of the present invention. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described below with reference to the drawings. In the description of the specification and claims of this application, the width direction refers to the width direction of the flooring material (including intermediate flooring materials), in other words, the short side direction of the flooring material. The length direction refers to the length direction of the flooring material, in other words, the long side direction of the flooring material. The outward direction is the direction away from the center of the flooring material, and the inward direction is the direction towards the center of the flooring material. In the description of the specification and claims of this application, "X~Y" representing a numerical range means X or greater and Y or less. In the drawings, "WD" refers to the width direction and "LD" refers to the length direction.

[0024] [Composition of flooring materials] The configuration of the flooring material 10 according to an embodiment of the present invention will be described with reference to Figures 1 to 6. Figure 1 is a schematic perspective view of the flooring material 10 according to an embodiment of the present invention, viewed from the back side. Figure 2 is a schematic perspective view of the flooring material 10 according to an embodiment of the present invention, viewed from the front side. Figure 3 is a schematic cross-sectional view of the floor structure 14 according to an embodiment of the present invention. Figures 4 and 5 are schematic partial cross-sectional views of the floor structure 14 including the male tongue and female tongue and groove portion 32 and female tongue and groove portion 34 formed by tongue and groove processing. Figure 6 is a schematic partial cross-sectional view of the floor structure including the male tongue and female tongue and groove portion 32 and female tongue and groove portion 34 formed by interlocking joint processing.

[0025] (Overall composition of flooring material 10: foamed resin layer 16, non-foamed resin layer 18, decorative layer 20) As shown in Figures 1 to 4, the flooring material 10 according to an embodiment of the present invention is used in a floor structure 14 installed on a floor base material 12 and is formed in a rectangular shape. The flooring material 10 has a rectangular foamed resin layer 16 and a rectangular non-foamed resin layer 18 laminated on the surface side (upper side) of the foamed resin layer 16. The foamed resin layer 16 is a layer that mainly provides the flooring material 10 with heat insulation, load-bearing capacity, and impact resistance, and is formed by foaming a foamed resin composition. The non-foamed resin layer 18 is a layer that mainly provides the flooring material 10 with shape stability, water resistance, moisture resistance, impact resistance, and scratch resistance. The surface of the foamed resin layer 16 and the back surface of the non-foamed resin layer 18 are bonded together via an adhesive layer (not shown). The flooring material 10 also has a decorative layer 20 laminated on the surface side of the non-foamed resin layer 18, and the decorative layer 20 is a layer that provides decorative properties to the flooring material 10.

[0026] (Base resin layer 22, pattern layer 24, transparent resin layer 26, adhesive layer 28, surface protection layer 30) As shown in Figure 5, the decorative layer 20 may include a base resin layer 22 laminated on the surface side of the non-foamed resin layer 18, a pattern layer 24 laminated on the surface side of the base resin layer 22, and a transparent resin layer 26 laminated on the surface side of the pattern layer 24. The base resin layer 22 is an optional layer provided as needed, and the transparent resin layer 26 is an optional layer provided to protect the pattern layer 24. The decorative layer 20 may also include an adhesive layer 28 interposed between the surface of the pattern layer 24 and the back surface of the transparent resin layer 26, and a surface protection layer 30 laminated on the surface side of the transparent resin layer 26. The adhesive layer 28 is an optional layer provided to bond the base resin layer 22 and the transparent resin layer 26. The surface protection layer 30 is a layer that imparts surface properties such as impact resistance, load-bearing capacity, and scratch resistance to the flooring material 10, and is an optional layer provided on the outermost surface of the flooring material 10 as needed.

[0027] (Male fruit part 32, female fruit part 34) As shown in Figures 1 to 5, a male tongue-and-groove portion 32, which is a projection that extends outward, is formed on one end face of the flooring material 10 in the width direction and length direction by tongue-and-groove processing. Each male tongue-and-groove portion 32 extends from one end to the other in the width direction or length direction of the flooring material 10. A female tongue-and-groove portion 34, which is a groove with a transverse U-shaped cross-section, is formed on the other end face of the flooring material 10 in the width direction and / or length direction by tongue-and-groove processing. Each female tongue-and-groove portion 34 extends from one end to the other in the width direction or length direction of the flooring material 10. Furthermore, in a pair of adjacent flooring materials 10 in the width direction and / or length direction, the male tongue-and-groove portion 32 of one flooring material 10 can be fitted into the female tongue-and-groove portion 34 of the other flooring material 10. Note that the end face in the width direction of the flooring material 10 is the small end, and the end face in the length direction of the flooring material 10 is the end grain.

[0028] As shown in Figure 6, instead of forming a male tongue portion 32 on one end face in the width and length directions of the flooring material 10 by tongue and groove processing, a male tongue portion 32, which is a protruding ridge outward, may be formed by interlocking. Instead of forming a female tongue portion 34, which is a groove with a transverse U-shaped cross-section, on the other end face in the width and length directions of the flooring material 10 by tongue and groove processing, a female tongue portion 34, which is a groove with a cross-section L-shaped, may be formed by interlocking.

[0029] As shown in Figures 4 to 6, the upper part of the male fruit portion 32 is made of a non-foamed resin layer 18, and the lower part of the male fruit portion 32 is made of a foamed resin layer 16. In other words, the male fruit portion 32 is made of a non-foamed resin layer 18 and a foamed resin layer 16. Similarly, the upper part of the female fruit portion 34 is made of a non-foamed resin layer 18, and the lower part of the female fruit portion 34 is made of a foamed resin layer 16. In other words, the female fruit portion 34 is made of a non-foamed resin layer 18 and a foamed resin layer 16.

[0030] If adjacent floorboards 10 are joined by fitting together the male and female tongue-and-groove parts 32 and 34 having such a structure, even if the adjacent floorboards 10 separate, the foamed resin layer 16 will not be exposed from the gap between the adjacent floorboards 10, thus preserving the aesthetic appearance of the floorboards 10. Furthermore, the processing of the male and female tongue-and-groove parts 32 and 34, which are the joints between adjacent floorboards 10, becomes easier, and sufficient fitting strength between the male and female tongue-and-groove parts 32 and 34 can be achieved. In addition, since the foamed resin layer 16 has cushioning properties, cracking or chipping of the relatively thin non-foamed resin layer 18 can be prevented during the fitting work between the male and female tongue-and-groove parts 32 and 34, enabling easy installation.

[0031] As shown in Figures 3, 4 to 6, when a pair of flooring materials 10 adjacent to each other in the width and / or length direction are fully fitted together, a gap (a predetermined gap) is formed between the foamed resin layer 16 of one flooring material 10 and the foamed resin layer 16 of the other flooring material 10. As a result, when a pair of flooring materials 10 adjacent to each other in the width and / or length direction are joined, the only contact points between the foamed resin layer 16 of one flooring material 10 and the foamed resin layer 16 of the other flooring material 10 are the contact points between the portion constituting the male joint 32 and the portion constituting the female joint 34. Therefore, contact between the foamed resin layers 16 between adjacent flooring materials 10 can be minimized, and floor creaking or squeaking noises caused by contact between the foamed resin layers 16 between adjacent flooring materials 10 can be effectively suppressed. The predetermined gap is 10 mm or less. If the specified gap exceeds 10 mm, the thermal insulation properties of the flooring material 10 may decrease, or the strength of the flooring material 10 may decrease. A more preferable upper limit for the specified gap is 6 mm. A preferable lower limit for the specified gap is 0.5 mm.

[0032] In the fitting portion composed of a male part 32 and a female part 34, the ratio of the thickness of the foamed resin layer 16 to the thickness of the fitting portion (thickness of the male part 32) is not particularly limited, as long as sufficient fitting strength between the male part 32 and the female part 34 can be achieved and floor creaking or squeaking noises can be suppressed, but 40% to 60% is preferred, and 45% to 55% is more preferred.

[0033] (Concave step 36) As shown in Figures 1, 3 to 6, recessed steps 36 are formed on both ends in the width direction of the back surface of the foamed resin layer 16, and each recessed step 36 extends from one end to the other in the length direction of the foamed resin layer 16. Each recessed step 36 is connected to the end face (small end) in the width direction of the flooring material 10.

[0034] The width of each recessed section 36 is preferably 20 mm to 40 mm, and more preferably 20 mm to 30 mm. The reason for making the width of each recessed section 36 20 mm or more is that if it is less than 20 mm, there is a concern that the adhesive applied to the recessed section 36 will seep out from the recessed section 36, wrap around to the end face in the width direction of the flooring material 10 and the decorative layer 20, and cause contamination by the adhesive, as well as making it impossible to secure the adhesive application width necessary to maintain stable adhesion. The reason for making the width of each recessed section 36 40 mm or less is that if it exceeds 40 mm, the ratio of the width of the recessed section 36 to the width of the flooring material 10 increases, which tends to reduce the rigidity of the flooring material 10, and there is a concern that the area where adhesive is not applied to the recessed section 36 will relatively increase, causing a step difference between the area where adhesive is applied and the area where it is not.

[0035] The depth of each recessed section 36 is preferably 8% to 30% of the thickness of the foamed resin layer 16 in the width direction, and more preferably 15% to 25%. The reason for making the depth of each recessed section 36 8% or more of the thickness of the foamed resin layer 16 in the width direction is that if it is less than 8%, there is a concern that the adhesive applied to the recessed section 36 will seep out from the recessed section 36, wrap around to the width direction edge of the flooring material 10 and the decorative layer 20, and cause contamination by the adhesive. The reason for making the depth of each recessed section 36 30% or less of the thickness of the foamed resin layer 16 in the width direction is that if it exceeds 30%, when the flooring material 10 is directly attached to the subfloor material 12, the adhesive applied to the recessed section 36 will not make sufficient contact with the subfloor material 12, and stable adhesion of the flooring material 10 to the subfloor material 12 cannot be ensured. If the depth of each recessed section 36 exceeds 30% of the thickness of the central part in the width direction of the foamed resin layer 16, the ends of the flooring material 10 in the width direction become too thin, making it difficult to form the male and female parts 32 and 34.

[0036] (2nd concave step) In addition to forming recessed sections 36 on both ends in the width direction on the back surface of the foamed resin layer 16, second recessed sections (not shown) may also be formed on both ends in the length direction on the back surface of the foamed resin layer 16. In this case, each second recessed section extends from one end to the other in the width direction of the foamed resin layer 16, and each second recessed section is connected to the end face (edge) in the length direction of the flooring material 10. The width dimension of each second recessed section is preferably 20 mm to 40 mm, and more preferably 20 mm to 30 mm. The amount of recess of each second recessed section is preferably 8% to 30% of the thickness of the central part in the width direction of the foamed resin layer 16, and more preferably 15% to 25%.

[0037] (Flooring thickness 10) As shown in Figures 1 and 2, the thickness of the flooring material 10 is preferably 5 mm or more, more preferably 6 mm to 30 mm, and even more preferably 10 mm to 20 mm, from the viewpoint of obtaining excellent impact resistance, heat insulation, water resistance, moisture resistance, load-bearing capacity, and scratch resistance. Furthermore, considering the ease of installation of the flooring material 10, it is preferable that it be the same thickness as the wood flooring material installed in areas other than wet areas such as living rooms and corridors. The thickness of wood flooring material is usually 8 mm, 12 mm, 15 mm, etc., with 12 mm being the standard thickness.

[0038] Next, we will explain the physical properties of the foamed resin layer 16 and other components that make up the flooring material 10.

[0039] (Physical properties of the foamed resin layer 16, etc.) As shown in Figures 1, 2, and 4, the foamed resin layer 16 is a layer that primarily imparts heat insulation, load-bearing capacity, and impact resistance to the flooring material 10, as described above, and is formed by foaming a foamed resin composition. The foaming ratio of the foamed resin layer 16 is preferably 10 to 20 times. If it falls outside this range, the flooring material 10 may not have good heat insulation, load-bearing capacity, and impact resistance. To obtain even better heat insulation and load-bearing capacity for the flooring material 10, the foaming ratio of the foamed resin layer 16 is more preferably 10 to 15 times.

[0040] The compressive modulus of the foamed resin layer 16 is preferably 15 MPa or higher. If the compressive modulus of the foamed resin layer 16 is less than 15 MPa, a flooring material 10 with excellent load-bearing capacity and impact resistance may not be obtained. In order for the flooring material 10 to obtain even better load-bearing capacity and impact resistance, the compressive modulus of the foamed resin layer 16 is more preferably greater than 15 MPa and 150 MPa or less, and even more preferably between 20 MPa and 120 MPa.

[0041] Here, the compressive modulus is the value obtained by preparing test specimens using the foamed resin layer 16 and the method described in JIS A9511:2009 "Foamed Plastic Thermal Insulation Materials". Specifically, a rectangular parallelepiped-shaped test specimen measuring 100 mm in length, 100 mm in width, and 3 mm in thickness is cut from the foamed resin layer 16, and the compressive modulus is measured using a tensile-compression testing machine at a compression speed of 10 mm / min from a direction perpendicular to the thickness direction. Five test specimens are prepared, and the compressive modulus is measured for each specimen as described above, and the arithmetic mean of these values ​​is taken as the compressive modulus. Note that the thickness of the rectangular parallelepiped-shaped test specimen has been changed to 3 mm, not the thickness specified in JIS.

[0042] The foaming method for the foamed resin composition constituting the foamed resin layer 16 is not particularly limited, and any known method can be used, but foaming by the bead method is preferred from the viewpoint of obtaining a homogeneous foamed resin layer 16. The bead method is a method in which foamed resin particles (pre-foamed particles) are used as raw materials, the foamed resin particles are filled into the cavity of a mold, and the filled pre-foamed particles are secondarily foamed with steam, while the pre-foamed particles are integrated with each other by heat fusion to obtain a foamed resin layer.

[0043] Preferably, thermoplastic resins are used as resins for foamed resin particles. Preferred thermoplastic resins include polyolefin resins such as polystyrene resin (PS), polyethylene (PE), polypropylene (PP), styrene-modified polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), and ethylene-(meth)acrylic acid resin; polyvinyl resins such as acrylonitrile-butadiene-styrene copolymer (ABS resin), acrylonitrile-styrene copolymer, polyvinyl chloride resin (PVC), polyvinyl acetate resin, and polyvinyl alcohol resin; polyester resins such as polyethylene terephthalate resin (PET resin); polyamide resins, polyacetal resins, acrylic resins, polycarbonate resins, and polyurethane resins; and thermoplastic resins, either individually or as copolymers thereof, or as mixtures thereof. Among these, polystyrene resins are preferred when considering the strength of the resin itself.

[0044] The styrene monomer used to form the polystyrene resin is not particularly limited, and any known styrene monomer can be used. Examples include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, ethylstyrene, isopropylstyrene, dimethylstyrene, and bromostyrene. These styrene monomers may be used individually or as a mixture of several types. The preferred styrene monomer is styrene.

[0045] The foamed resin particles used in the bead method are typically obtained by polymerizing seed particles made of resin, absorbing monomers such as styrene monomer along with plasticizers as needed, and then impregnating the resin particles with a foaming agent either simultaneously with or after polymerization, followed by foaming. Alternatively, foamed resin particles can also be obtained by impregnating particles obtained by suspension polymerization of monomers such as styrene monomer in an aqueous medium with a foaming agent, or by introducing polystyrene resin into an extruder, melt-kneading it with a foaming agent, extruding it through a die with small holes into pressurized circulating water, cutting it with a rotating cutter in contact with the die, and then foaming the resulting particles.

[0046] Preferred blowing agents for use in the bead process include, for example, inorganic blowing agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate, ammonium carbonate, and ammonium nitrite as chemical blowing agents; nitroso compounds such as N,N'-dimethyl-N,N'-dinitrosoterephthalamide and N,N'-dinitrosopentamethylenetetramine; azo compounds such as azodicarbonamide, azobisformamide, azobisisobutyronitrile, azocyclohexylnitrile, and azodiaminobenzene; sulfonyl hydrazide compounds such as benzenesulfonyl hydrazide and toluenesulfonyl hydrazide; and azide compounds such as calcium azide, 4,4'-diphenyldisulfonyl azide and p-toluenesulfonyl azide. Furthermore, preferred blowing agents include aliphatic hydrocarbons such as propane, n-butane, isopentane, n-pentane, and neopentane as physical blowing agents, as well as volatile blowing agents such as fluorinated hydrocarbons with zero ozone depletion potential, such as difluoroethane and tetrafluoroethane. These foaming agents can be used individually or in combination. The amount of foaming agent added can be determined appropriately according to the desired foaming ratio and compressive modulus, but preferably 0.5 to 15 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of resin.

[0047] Examples of plasticizers used in the bead process include fatty acid ester compounds such as propylene glycol fatty acid esters, glycerin fatty acid esters, sorbitan fatty acid esters, and sucrose fatty acid esters; phthalate ester compounds such as dibutyl phthalate (DBP), dioctyl phthalate (DOP), and diisononyl phthalate (DINP); adipate ester compounds such as diisobutyl adipate and dioctyl adipate; sebacate ester compounds such as dibutyl sebacate and di-2-ethylhexyl sebacate; glycerin fatty acid ester compounds such as glycerin tristearate and glycerin tricaprylate; and natural oils and fats such as liquid paraffin, coconut oil, palm oil, and rapeseed oil.

[0048] The plasticizer may be added when polymerizing the monomer or when impregnating with a foaming agent. The amount of plasticizer to be added can be appropriately determined according to the desired foaming ratio and compressive modulus, but preferably 0.2 parts by mass or more and less than 3 parts by mass, and more preferably 0.4 parts by mass or more and less than 1.6 parts by mass, per 100 parts by mass of resin. If the amount of plasticizer added is 0.2 parts by mass or more, the secondary transition temperature will be lower, which is advantageous for pre-foaming and molding at low temperatures. If the amount of plasticizer added is less than 3 parts by mass, the foam will be less prone to shrinkage and a good appearance can be obtained. In addition, the foamed resin particles may contain additives such as flame retardants, flame retardant aids, lubricants, anti-bonding agents, fusion accelerators, antistatic agents, spreading agents, bubble regulators, crosslinking agents, fillers, colorants, and heat insulating agents (radiation suppressants, etc.), as long as they do not impair the physical properties.

[0049] In the bead method, for example, foamed resin particles are filled into the cavity of a mold, and the filled pre-foamed particles are subjected to secondary foaming for 10 to 40 seconds using a heat transfer medium such as steam at 100 to 150°C, preferably 100 to 120°C, while the pre-foamed particles are fused together by heat to obtain a foamed resin layer. In this case, the average particle size of the foamed resin particles used is generally preferably 0.2 to 4 mm, and more preferably 0.5 to 2 mm. The average particle size of the foamed resin particles is obtained by stacking multiple sieves with different mesh sizes, as specified in JIS Z8801-1 "Test sieves - Part 1: Metal mesh sieves," from the sieves with smaller mesh sizes to the sieves with larger mesh sizes, placing 100 g of foamed resin particles into the top sieve, and vibrating the sieve to classify the foamed particles.

[0050] The foamed resin layer 16 can be obtained not only by the bead method described above, but also by forming an unfoamed resin layer using a resin composition for forming a foamed resin layer, which includes a resin for foamed resin layers, a foaming agent, a plasticizer, an inorganic filler, and other additives as needed, by a film-forming method such as extrusion film formation using a T-die or calender film formation, and then foaming it at about 220 to 250°C using a heated foaming furnace. In addition, as long as the foamed resin layer 16 is within the range of a predetermined foaming ratio and compressive modulus, commercially available insulation boards, such as bead-formed polystyrene foam insulation boards and extruded polystyrene foam insulation boards, can also be used.

[0051] The thickness of the foamed resin layer 16 varies somewhat depending on the foaming ratio, but is preferably 3 mm to 15 mm, more preferably 5 mm to 15 mm, and even more preferably 7 mm to 12 mm. When the thickness of the foamed resin layer 16 is within the above range, a flooring material 10 with excellent heat insulation, load-bearing capacity, and impact resistance can be obtained.

[0052] When forming the male and female parts 32 and 34, it is preferable to compress both ends of the flooring material 10 in the width direction and length direction with a clamping member to form recessed steps 36 on both ends of the width direction on the back surface of the foamed resin layer 16. For this reason, the 10% compressive strength of the foamed resin layer 16 is preferably 1.5 MPa or less, and more preferably 1.0 MPa or less. If the 10% compressive strength of the foamed resin layer 16 exceeds 1.5 MPa, it tends to become difficult to form recessed steps by compression with a clamping member. There is no particular lower limit for the 10% compressive strength of the foamed resin layer 16, but considering the crushing of the foamed resin layer 16 during actual use of the flooring material 10, it is preferable to have a value of 0.5 MPa or more. In this specification, "10% compressive strength" may be referred to as the 10% compressive modulus.

[0053] It is preferable that the foamed resin layer 16 is thicker than the non-foamed resin layer 18. A flooring material 10 with excellent heat insulation, load-bearing capacity, and impact resistance can be obtained by having a foamed resin layer 16 thicker than the non-foamed resin layer 18, and warping (stress warping) caused by differences in expansion due to moisture, etc., between the foamed resin layer 16 and other layers such as the non-foamed resin layer 18 is less likely to occur.

[0054] (Physical properties of the non-foamed resin layer 18, etc.) As shown in Figures 1, 2, and 4, the non-foamed resin layer 18 is, as described above, a layer that mainly imparts dimensional stability, water resistance, moisture resistance, impact resistance, and scratch resistance to the flooring material 10. The tensile modulus of the non-foamed resin layer 18 is preferably 180 MPa or higher. If the tensile modulus of the non-foamed resin layer 18 is less than 180 MPa, a scratch-resistant flooring material 10 cannot be obtained. In order to obtain a flooring material 10 with excellent water resistance, moisture resistance, and scratch resistance, the tensile modulus of the non-foamed resin layer 18 is preferably 180 MPa to 3000 MPa, more preferably 1,000 MPa to 3,000 MPa, and even more preferably 2,000 MPa to 2,500 MPa. When the tensile modulus of the non-foamed resin layer 18 is within the above range, warping caused by differences in elongation due to temperature, etc., between it and other layers such as the foamed resin layer 16 becomes less likely.

[0055] Here, the tensile modulus (E) was calculated from the initial straight portion of the tensile stress-strain curve obtained by preparing a non-foamed resin layer 18 punched out from a dumbbell-shaped test specimen as described in JIS K6732 (1996), and measuring it using a tensile-compression testing machine at a temperature of 20°C with a tensile speed of 50 mm / min and a chuck distance of 80 mm, using the following formula. E = △p / △E E: Tensile modulus △p: Stress difference due to the original average cross-sectional area between two points on a straight line △E: Difference in strain between the same two points

[0056] The non-foamed resin layer 18 preferably contains a thermoplastic resin. Preferred thermoplastic resins for the non-foamed resin layer 18 include polyvinyl resins such as polyvinyl chloride resin, polyvinyl acetate resin, and polyvinyl alcohol resin; polyolefin resins such as polyethylene resin, polypropylene resin, styrene-modified polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), and ethylene-(meth)acrylic acid resin; polyester resins such as polystyrene resin and polyethylene terephthalate resin (PET resin); acrylic resins; polycarbonate resins; polyurethane resins; acrylonitrile-butadiene-styrene copolymer (ABS resin); acrylonitrile-styrene copolymer; and other thermoplastic resins, both individual and copolymers, or mixtures thereof. In particular, polyolefin resin, acrylonitrile-butadiene-styrene copolymer, or polyvinyl chloride resin are preferred as the thermoplastic resin for the non-foamed resin layer 18.

[0057] The non-foamed resin layer 18 preferably contains an inorganic compound. The inclusion of an inorganic compound in the non-foamed resin layer 18 reduces its coefficient of thermal expansion, thereby suppressing warping of the flooring material 10. Examples of inorganic compounds include talc, calcium carbonate, silica, and mica. The inorganic compound content is preferably 10 to 75 parts by mass per 100 parts by mass of the resin component in the non-foamed resin layer 18. If the inorganic compound content in the non-foamed resin layer 18 is less than 10 parts by mass, the coefficient of thermal expansion of the non-foamed resin layer 18 may not be sufficiently reduced. If the inorganic compound content in the non-foamed resin layer 18 exceeds 75 parts by mass, the tensile modulus of the non-foamed resin layer 18 may be insufficient. A more preferable range for the inorganic compound content in the non-foamed resin layer 18 is 10 to 70 parts by mass.

[0058] The non-foaming resin layer 18 may consist of one layer or a laminate consisting of two or more layers, but it is preferable that it be a laminate in which at least one layer contains a glass component. That is, it is preferable that the non-foaming resin layer 18 is a laminate consisting of two or more layers, in which at least one layer is a thermoplastic resin layer and the other layer is a glass component layer containing a glass component. By adopting such a configuration, a flooring material 10 with excellent impact resistance can be obtained, and the shape stability of the flooring material 10 can be improved. The glass component layer containing a glass component is preferably, for example, a layer made of glass fibers.

[0059] The non-foamed resin layer 18 is preferably a laminate in which thermoplastic resin layers and glass component layers are alternately laminated, and in particular, it is preferably a laminate having a first thermoplastic resin layer, a glass component layer, and a second thermoplastic resin layer in that order. When the non-foamed resin layer 18 has multiple thermoplastic resin layers, the types of resins forming the multiple thermoplastic resin layers may be the same or different, and the thicknesses of the multiple thermoplastic resin layers may be the same or different.

[0060] The thickness of the non-foamed resin layer 18 is preferably 0.3 mm to 10 mm, and more preferably 1 mm to 5 mm. When the thickness of the non-foamed resin layer 18 is within the above range, a flooring material 10 with excellent water resistance, moisture resistance, impact resistance, and scratch resistance can be obtained, and warping caused by differences in expansion due to temperature, etc., between the non-foamed resin layer 18 and other layers such as the foamed resin layer 16 is less likely to occur. Furthermore, as mentioned above, it is preferable that the thickness of the non-foamed resin layer 18 be thinner than the thickness of the foamed resin layer 16. By making the thickness of the non-foamed resin layer 18 thinner than the thickness of the foamed resin layer 16, warping (stress warping) caused by differences in expansion due to temperature, etc., between the non-foamed resin layer 18 and other layers such as the foamed resin layer 16 is less likely to occur.

[0061] (Linear expansion coefficient of foamed resin layer 16 and linear expansion coefficient of non-foamed resin layer 18) As shown in Figures 1, 2, and 4, the coefficient of linear expansion of the foamed resin layer 16 and the coefficient of linear expansion of the non-foamed resin layer 18 are 8 × 10⁻⁶, respectively. -5It is preferable that the coefficient of thermal expansion of the foamed resin layer 16 and / or the non-foamed resin layer 18 is 8 × 10. -5 When the temperature exceeds / ℃, the expansion and contraction of the flooring material 10 in response to temperature changes becomes large. If the expansion of the flooring material 10 is large, warping of the flooring material 10 or buckling of the fitting parts may occur, and if the contraction of the flooring material 10 is large, problems such as gaps opening in the fitting parts may occur. The linear expansion coefficients of the foamed resin layer 16 and the non-foamed resin layer 18 are, respectively, 6 × 10 -5 It is more preferable that the temperature be below / ℃.

[0062] The difference between the coefficient of thermal expansion of the foamed resin layer 16 and the coefficient of thermal expansion of the non-foamed resin layer 18 is 3 × 10⁻⁶. -5 It is preferable that the temperature is within / ℃. The difference between the linear expansion coefficient of the foamed resin layer 16 and the linear expansion coefficient of the non-foamed resin layer 18 is 3 × 10 -5 When the temperature exceeds 10°C, the difference in the degree of expansion and contraction of each layer in response to temperature changes becomes large, which can cause significant warping of the flooring material 10. The difference between the linear expansion coefficient of the foamed resin layer 16 and the linear expansion coefficient of the non-foamed resin layer 18 is 2 × 10 -5 It is more preferable that it be within / ℃, 1 × 10 -5 It is even more preferable that the temperature be within / ℃.

[0063] Here, rectangular parallelepiped test pieces measuring 145 mm in length and 300 mm in width are cut from the foamed resin layer 16 and the non-foamed resin layer 18. The lateral dimensions of the test pieces are measured when their temperatures are stabilized at 0°C and 40°C using a constant temperature bath, and the dimensional change per unit temperature obtained from the dimensional change rate is defined as the linear expansion coefficient of the foamed resin layer 16 and the linear expansion coefficient of the non-foamed resin layer 18.

[0064] (Physical properties of decorative layer 20, etc.) As shown in Figures 1, 2, 4, and 5, the decorative layer 20 is a layer that provides decorative properties to the flooring material 10, as described above. The decorative layer 20 may be, for example, a uniformly colored opaque layer (solid print layer), a pattern layer formed by printing various patterns using ink and a printing press, or a layer combining an opaque layer and a pattern layer (hereinafter referred to as the pattern layer). The decorative layer 20 may also be a pattern created by a transfer method, or a veneer or sawn board made by thinly slicing wood. The decorative layer 20 may also be a decorative sheet having a base resin layer 22, a pattern layer 24, a transparent resin layer 26, an adhesive layer 28, and a surface protection layer 30.

[0065] If the decorative layer 20 is a concealing layer, it can conceal the subfloor material 12 to which the flooring material 10 is directly attached, and even if there are color inconsistencies in the foamed resin layer 16 or non-foamed resin layer 18, the intended colors can be applied to even out the surface color of the flooring material 10. If the decorative layer 20 is a patterned layer, patterns such as wood grain, marble patterns (e.g., travertine marble patterns) that mimic the surface of rocks, fabric patterns that mimic the texture of cloth or cloth-like patterns, tile patterns, brick patterns, or combinations of these such as parquet or patchwork patterns can be applied to the flooring material 10. These patterns can be formed by multicolor printing using the usual yellow, red, blue, and black process colors, or by multicolor printing using spot colors, where individual color plates are prepared to make up the pattern.

[0066] The ink composition used for the decorative layer 20 is a binder resin mixed with appropriate amounts of colorants such as pigments and dyes, extender pigments, solvents, stabilizers, plasticizers, catalysts, and curing agents. There are no particular restrictions on the binder resin, but for example, urethane resin, vinyl chloride / vinyl acetate copolymer resin, vinyl chloride / vinyl acetate / acrylic copolymer resin, acrylic resin, polyester resin, nitrocellulose resin, etc. are preferred. Any one of these binder resins can be used individually or in a mixture of two or more. Preferred colorants include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, lead yellow, titanium yellow, iron oxide, cadmium red, ultramarine, and cobalt blue; organic pigments such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; or dyes; metallic pigments consisting of flaky foil pieces such as aluminum and brass; and pearlescent pigments consisting of flaky foil pieces such as titanium dioxide-coated mica and basic lead carbonate.

[0067] The thickness of the decorative layer 20 is usually preferably about 5 μm to 3 mm. If the decorative layer 20 is an opaque layer (solid print layer), a pattern layer, a pattern layer combining an opaque layer and a pattern layer, or a pattern provided by a transfer method, the thickness of the decorative layer 20 is preferably about 20 μm or less. If the decorative layer 20 is a veneer or sawn board, the thickness of the decorative layer 20 is preferably about 0.5 mm to 3 mm. If the thickness of the decorative layer 20 is within the above range, the flooring material 10 can be given excellent design and opacity.

[0068] (Physical properties of the base resin layer 22, etc.) As shown in Figure 5, the base resin layer 22 is a layer that can be provided as desired, and is preferably formed of a thermoplastic resin. A polyolefin resin is preferred as the thermoplastic resin for forming the base resin layer 22, and polyethylene resin and polypropylene resin are more preferred in particular.

[0069] (Physical properties of the transparent resin layer 26, etc.) As shown in Figure 5, the transparent resin layer 26 is an optional layer provided to protect the decorative layer 20, as described above, and is a transparent resin layer that allows the decorative layer 20 to be seen through, and is formed of a thermoplastic resin. As the thermoplastic resin forming the transparent resin layer 26, polyolefin resins are preferred, and polyethylene resins, polypropylene resins, and ionomer resins are more preferred.

[0070] (Physical properties of adhesive layer 28, etc.) As shown in Figure 5, the adhesive layer 28 is an optional layer provided to bond the base resin layer 22 and the transparent resin layer 26, as described above. Preferred adhesives for the adhesive layer 28 include, for example, urethane adhesives, acrylic adhesives, and polyamide adhesives. These adhesives can be used individually or as a mixture of two or more.

[0071] (Physical properties of surface protective layer 30, etc.) As shown in Figure 5, the surface protection layer 30 is an optional layer provided on the outermost surface of the flooring material 10 as needed, to impart surface properties such as impact resistance, load-bearing capacity, and scratch resistance to the flooring material 10, as described above. The surface protection layer 30 is preferably composed of a resin composition containing a curable resin applied to a decorative layer, or preferably a transparent resin layer 26 and an adhesive layer 28, and then cured. By including a cross-linked curable resin, the surface properties of the flooring material 10 can be improved.

[0072] Preferably, the curable resin used to form the surface protective layer 30 is an ionizing radiation-curable resin or a thermosetting resin, and a so-called hybrid type using both an ionizing radiation-curable resin and a thermosetting resin may also be used. In order to increase the crosslinking density of the resin forming the surface protective layer 30 and improve the surface properties of the flooring material 10, an ionizing radiation-curable resin is preferred as the curable resin used to form the surface protective layer 30.

[0073] Ionizing radiation-curable resins are resins that possess energy quanta capable of crosslinking and polymerizing molecules in electromagnetic waves or charged particle beams, that is, resins that crosslink and harden when irradiated with ultraviolet light or electron beams. Specifically, they can be appropriately selected from polymerizable monomers, polymerizable oligomers, or prepolymers that have been conventionally used as ionizing radiation-curable resins. As polymerizable monomers, (meth)acrylate monomers having radical polymerizable unsaturated groups in the molecule are preferred, and polyfunctional (meth)acrylates are particularly preferred.

[0074] Examples of thermosetting resins used to form the surface protective layer 30 include epoxy resins, phenolic resins, urea resins, unsaturated polyester resins, melamine resins, alkyd resins, polyimide resins, silicone resins, hydroxyl-functional acrylic resins, carboxyl-functional acrylic resins, amide-functional copolymers, and urethane resins.

[0075] [Composition of the manufacturing method for flooring materials] Referring to Figures 7 to 9, the configuration of the method for manufacturing flooring materials according to the present invention will be described. Figure 7 is a schematic cross-sectional view illustrating the intermediate product formation process in the method for manufacturing flooring materials according to the present invention. Figure 8 is a schematic cross-sectional view illustrating the solid part formation process and the recessed step formation process in the method for manufacturing flooring materials according to the present invention. Figure 9 is a schematic cross-sectional view showing flooring materials manufactured by the method for manufacturing flooring materials according to the present invention.

[0076] As shown in Figures 7 to 9, the method for manufacturing flooring material according to the embodiment of the present invention is a method for manufacturing flooring material 10. The method for manufacturing flooring material according to the embodiment of the present invention includes a step of preparing a foamed resin layer, a step of preparing a non-foamed resin layer, a step of preparing a decorative layer, a step of bonding the non-foamed resin layer and the decorative layer, an intermediate product molding step (a step of bonding the foamed resin layer and the non-foamed resin layer), a step of forming a solid part, and a step of forming a recessed step. The specific details of each step in the method for manufacturing flooring material according to the embodiment of the present invention are as follows.

[0077] (Preparation process for the foamed resin layer) As shown in Figure 7, a foamed resin layer 16 having the above-described configuration is prepared. Specifically, the foamed resin layer 16 is produced by foaming at a preferred foaming ratio of 10 to 20 times, preferably by a film formation method such as the bead method, or an extrusion film formation method using a T-die with a foamed resin layer forming resin composition, or a calendering method, so that the compressive modulus is 15 MPa or more. The foaming ratio and compressive modulus of the foamed resin layer 16 can be appropriately adjusted by the foaming temperature, the type of resin, the amount of foaming agent and plasticizer used, etc.

[0078] (Preparation process for the non-foamed resin layer) As shown in Figure 7, a non-foamed resin layer 18 having the above-described configuration is prepared. Specifically, the non-foamed resin layer 18 is fabricated by a film-forming method such as extrusion film formation using a T-die or calendering film formation, so that the tensile modulus of elasticity is 180 MPa or higher. The tensile modulus of elasticity of the non-foamed resin layer 18 can be adjusted as appropriate depending on the type of resin, the type and amount of inorganic compound used, etc.

[0079] (Preparation process for the decorative layer) As shown in Figure 7, a pattern layer 24 is formed on the surface of the base resin layer 22 (see Figure 5) using an ink composition. The ink composition may be applied by methods such as gravure printing, offset printing, screen printing, flexographic printing, or inkjet printing. Furthermore, when forming an opaque layer (solid print layer), it may be formed by various coating methods such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating.

[0080] Next, the transparent resin layer 26 (see Figure 5) is preferably formed after the pattern layer 24 is formed, and if necessary, via an adhesive layer 28 (see Figure 5). The adhesive layer 28 can be formed by various coating methods such as gravure coating, bar coating, roll coating, reverse roll coating, comma coating, or by extrusion film formation using a T-die. The transparent resin layer 26 can then be formed by a method in which it is laminated simultaneously with film formation using extrusion film formation using a T-die, or by a method in which a film is pre-formed using a film formation method such as extrusion film formation using a T-die or calendering, and then laminated by dry lamination or thermal lamination.

[0081] Furthermore, the surface protection layer 30 (see Figure 5) can be formed by the following method. First, after the pattern layer 24 formation step or after the transparent resin layer 26 lamination step, a curable resin composition is applied to the surface of the pattern layer 24 or the surface of the transparent resin layer 26. At this time, an uncured resin layer is formed by applying the resin using a known method such as gravure coating, bar coating, roll coating, reverse roll coating, or comma coating, so that the thickness after curing is approximately 3 μm to 40 μm. Next, the surface protection layer 30 is formed by curing the uncured resin layer by applying heat or by irradiating it with ionizing radiation such as electron beams or ultraviolet rays. In the case of heat curing, the heating temperature is appropriately determined according to the resin used.

[0082] When using electron beams as ionizing radiation, the acceleration voltage can be appropriately selected according to the resin and layer thickness used, but it is generally preferable to cure the uncured resin layer with an acceleration voltage of approximately 70kV to 300kV. The irradiation dose is preferably the amount at which the crosslinking density of the resin layer saturates, and is usually selected in the range of 5kGy to 300kGy (0.5Mrad to 30Mrad), preferably 10kGy to 50kGy (1Mrad to 5Mrad). There are no particular restrictions on the electron source, and various electron beam accelerators such as Cockcroft-Walton type, Van de Graft type, resonant transformer type, insulated core transformer type, or linear type, Dynamitron type, and high-frequency type can be used. When using ultraviolet light as ionizing radiation, it emits ultraviolet light with a wavelength of 190 to 380 nm. There are no particular restrictions on the ultraviolet light source, and for example, high-pressure mercury lamps, low-pressure mercury lamps, metal halide lamps, carbon arc lamps, etc., can be used.

[0083] (Bonding process between non-foamed resin layer and decorative layer) As shown in Figure 7, when the decorative layer 20 is in sheet form, the surface of the non-foamed resin layer 18 and the back surface of the decorative layer 20 can be bonded using, for example, a heat-sensitive adhesive, a pressure-sensitive adhesive, or a hot-melt adhesive. As a hot-melt adhesive, a reactive hot-melt adhesive such as a urethane-based reactive hot-melt adhesive (hereinafter referred to as "PUR adhesive") is preferred. PUR adhesives contain a functional group (isocyanate group) that reacts with moisture in their components, and after cooling and curing, they react with moisture adhering to the substrate or decorative sheet or moisture supplied through them. After the reaction, PUR adhesives do not melt even when heated and have high adhesive strength.

[0084] (Intermediate product formation process (bonding process between foamed resin layer and non-foamed resin layer)) As shown in Figure 7, an intermediate product 10A of the flooring material 10 is formed by bonding the surface of the foamed resin layer 16 obtained in the preparation step of the foamed resin layer to the back surface of the non-foamed resin layer 18 on which the decorative layer 20 is formed. The adhesive shown in the bonding step between the non-foamed resin layer and the decorative layer can be used to bond the surface of the foamed resin layer 16 to the back surface of the non-foamed resin layer 18.

[0085] (Functional part formation process) As shown in Figure 8, using multiple cutters 38, a male joint portion 32 is formed on one end face in the width direction of the intermediate product 10A by tongue and groove machining (true tongue and groove machining or lap joint machining) from one end to the other in the length direction of the intermediate product 10A. At the same time, using a cutter 40, a female joint portion 34 is formed on the other end face in the width direction of the intermediate product 10A by tongue and groove machining from one end to the other in the length direction of the intermediate product 10A.

[0086] After forming the male and female parts 32 and 34 on the widthwise end faces of the intermediate product 10A, the male part 32 is formed by machining on one end face in the lengthwise direction of the intermediate product 10A, extending from one end to the other in the widthwise direction. Simultaneously, the female part 34 is formed by machining on the other end face in the lengthwise direction of the intermediate product 10A, extending from one end to the other in the widthwise direction.

[0087] (Process for forming recessed sections) As shown in Figure 8, when performing actual processing on the end face in the width direction of the intermediate product 10A, the end face in the width direction of the intermediate product 10A is clamped by a pair of pressure rolls 42, thereby compressing both ends in the width direction of the foamed resin layer 16 of the intermediate product 10A. This makes it possible to form recessed steps 36 on both ends in the width direction of the back surface of the foamed resin layer 16 of the intermediate product 10A, from one end to the other in the length direction of the intermediate product 10A. Each pressure roll 42 is a roll that can rotate around its axis and is an example of a clamping member.

[0088] In the process of forming the recessed portion, for the same reasons mentioned above for specifying the width dimension of the recessed portion 36 of the foamed resin layer 16 in the flooring material 10, the width dimension of the recessed portion 36 is set to 20 mm to 40 mm. For the same reasons mentioned above for specifying the amount of recess of the recessed portion 36 of the foamed resin layer 16 in the flooring material 10, the amount of recess of the recessed portion 36 is set to 8% to 30% of the thickness of the central part in the width direction of the foamed resin layer 16.

[0089] Alternatively, instead of the pair of pressure rolls 42, the widthwise end faces of the intermediate product 10A may be clamped by a pair of endless pressure belts (not shown). Each pressure belt is capable of circulating movement and is an example of a clamping member. Furthermore, instead of performing the recessed step formation process simultaneously with the solid part formation process as described above, it may be performed before or after the solid part formation process. For example, instead of compression molding both ends of the foamed resin layer 16 in the widthwise direction, the recessed step 36 may be formed by cutting both ends of the foamed resin layer 16 in the widthwise direction using a cutting machine such as a grinder before or after the solid part formation process.

[0090] Similarly, when performing actual processing on the longitudinal end face of the intermediate product 10A, the longitudinal end face of the intermediate product 10A may be clamped by a pair of pressure rolls, thereby compression molding both longitudinal ends of the foamed resin layer 16 in the intermediate product 10A. This allows for the formation of second recessed steps on both longitudinal ends of the back surface of the foamed resin layer 16 in the intermediate product 10A, extending from one end to the other in the width direction of the intermediate product 10A.

[0091] Then, as shown in Figure 9, by going through the aforementioned process of forming the fruit portion and the process of forming the recessed portion, a flooring material 10 having a male fruit portion 32, a female fruit portion 34, and a pair of recessed portions 36 can be manufactured.

[0092] [Construction method for floor structure] A method for constructing a floor structure according to an embodiment of the present invention will be described with reference to Figures 3, 9, and 10. Figure 10 is a schematic cross-sectional view illustrating a method for constructing a floor structure according to an embodiment of the present invention.

[0093] As shown in Figures 9 and 10, the method for constructing a floor structure according to an embodiment of the present invention is a method for constructing a floor structure 14 on a subfloor material 12 using flooring material 10. The method for constructing a floor structure according to an embodiment of the present invention includes a coating step and a direct bonding step. The specific details of each step in the method for constructing a floor structure according to an embodiment of the present invention are as follows.

[0094] (coating process) As shown in Figures 9 and 10, using an extrusion tube (not shown) containing adhesive B, the adhesive B is extruded from the extrusion tube while an application nozzle (not shown) installed at the supply port of the extrusion tube is used to apply the adhesive B in a bead-like manner to the center of the recessed step portion 36 of the foamed resin layer 16 in the width direction, over the entire length of the flooring material 10. The application of adhesive B is performed using the step line of the recessed step portion 36 of the foamed resin layer 16 (the line when the step surface of the recessed step portion 36 is viewed from above) as a guide. Provided that the necessary adhesive strength between the flooring material 10 and the floor base material 12 is ensured, the application of adhesive B does not need to be continuous over the entire length of the flooring material 10, but may be intermittent.

[0095] Examples of adhesive B used in the coating process include epoxy resins, urethane resins, cross-linked vinyl acetate resins, and modified silicone resins. The application width of adhesive B to the recessed step portions 36 of the foamed resin layer 16 in the flooring material 10 can be appropriately set, but it is preferably 15 mm to 35 mm, and more preferably 15 mm to 30 mm. The reason for setting the application width of adhesive B to 15 mm or more is that if it is less than 15 mm, stable adhesion between the flooring material 10 and the floor base material 12 tends not to be ensured. The reason for setting the application width of adhesive B to 35 mm or less is that if it exceeds 35 mm, there is a concern that the adhesive B will seep out from the recessed step portions 36 of the foamed resin layer 16, wrap around to the widthwise edge of the flooring material 10 and the decorative layer 20, and cause contamination by the adhesive B, as well as the use of excessive adhesive B.

[0096] (Direct application process) As shown in Figure 10, multiple flooring materials 10 are directly attached to the subfloor material 12 by the adhesive action of adhesive B, while fitting together the male and female tongue-and-groove portions 32 and female tongue-and-groove portions 34 of adjacent flooring materials 10 in the width direction and / or length direction. In the direct attachment process, the flooring materials 10 are directly attached to the subfloor material 12 solely by the adhesive action of adhesive B, without using adhesive tape.

[0097] Then, after going through the aforementioned coating and direct bonding processes, the floor structure 14 can be installed on the floor base material 12, as shown in Figure 3. The adhesive B used for direct bonding of the floor material 10 hardens to become an adhesive layer BC.

[0098] [Effects and Effects] Next, we will explain the effects of the flooring material 10, the effects of the manufacturing method of the flooring material, and the effects of the construction method of the floor structure.

[0099] (Effects of flooring material 10) In the flooring material 10 according to an embodiment of the present invention, as described above, recessed steps 36 are formed on both ends in the width direction of the back surface of the foamed resin layer 16, and each recessed step 36 extends from one end to the other in the length direction of the foamed resin layer 16. Therefore, by applying adhesive B in a bead shape to the recessed steps 36 of the foamed resin layer 16 so that the application width is 15 mm to 35 mm, it is possible to improve the workability of the floor structure 14 while suppressing steps in the flooring material 10, misalignment of the adhesive B application, and overflow of adhesive B onto the end faces in the width direction of the flooring material 10.

[0100] Furthermore, if the 10% compressive strength of the foamed resin layer 16 is 1.5 MPa or less, the recessed step portion 36 can be easily formed by compression using a pressure roll 42 or the like, thereby increasing the productivity (manufacturability) of the flooring material 10.

[0101] (Effects and benefits of flooring material manufacturing methods) In the method for manufacturing flooring materials according to an embodiment of the present invention, as described above, recessed stepped portions 36 are formed on both ends in the width direction of the back surface of the foamed resin layer 16 of the intermediate product 10A of the flooring material 10. This makes it possible to manufacture flooring materials 10 having recessed stepped portions 36. Therefore, by applying adhesive B in a bead shape to the recessed stepped portions 36 of the foamed resin layer 16 so that the application width is 15 mm to 35 mm, it is possible to improve the workability of the floor structure 14 while suppressing steps in the flooring material 10, misalignment of the application of adhesive B, and overflow of adhesive B to the end faces in the width direction of the flooring material 10.

[0102] In the method for manufacturing flooring material according to an embodiment of the present invention, when performing a joint process on the end face of the intermediate product 10A, both ends of the intermediate product 10A in the width direction are clamped by a pair of clamping members such as pressure rolls 42, thereby compressing and molding both ends of the foamed resin layer 16 in the width direction of the intermediate product 10A to form a recessed step portion 36. In other words, a joint portion (male joint portion 32 and female joint portion 34) is formed on the end face of the intermediate product 10A, and at the same time, a recessed step portion 36 is formed on the end side in the width direction of the back surface of the foamed resin layer 16 of the intermediate product 10A. Therefore, the manufacturing time of the flooring material 10 can be shortened and the productivity of the flooring material 10 can be increased.

[0103] (Effects and benefits of floor structure construction methods) In the construction method of the floor structure according to the embodiment of the present invention, as described above, adhesive B is applied in a bead-like manner to the recessed step portion 36 of the foamed resin layer 16 of the floor material 10. Therefore, by setting the application width of adhesive B to 15 mm to 35 mm, it is possible to improve the workability of the floor structure 14 while suppressing steps in the floor material 10, misalignment of the adhesive B application, and overflow of adhesive B onto the end faces in the width direction of the floor material 10.

[0104] In the construction method of the floor structure according to the embodiment of the present invention, as described above, the floor material 10 is directly attached to the subfloor material 12 by the adhesive action of adhesive B alone, while fitting the male tongue-and-groove portions 32 and female tongue-and-groove portions 34 of adjacent floor material 10 in the width direction and / or length direction, without using adhesive tape. Therefore, the fitting (fitting positioning) of the tongue-and-groove portions of the floor material 10 is not hindered by adhesive tape, and the workability of the floor structure 14 can be further improved. However, when adhesive B and adhesive tape are used in combination, the adhesive tape adheres to the subfloor material 12 before the adhesive B hardens, which is undesirable because it makes it difficult to work when fitting and positioning the tongue-and-groove portions of the floor material 10.

[0105] [Additional Notes] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in each embodiment are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Examples]

[0106] The following describes embodiments of the present invention, including comparative examples.

[0107] (Evaluation and measurement methods) The flooring materials obtained in the examples and comparative examples were evaluated and measured using the following methods.

[0108] <Evaluation of 10% Compression Modulus> Using a foamed resin layer, test specimens were prepared using part of the method described in JIS A9511:2009 "Foamed Plastic Thermal Insulation Materials," and predetermined measurements were performed. The 10% compressive modulus of the foamed resin layer was calculated from the value of the compressive strength at a 10% displacement in the thickness direction.

[0109] <Construction quality> A urethane-based adhesive was applied to both ends (including recessed sections) in the width direction of the back surface of a 300mm wide x 900mm long flooring material to a predetermined application width. Four flooring materials were then installed on a subfloor (particle board) (cured for one day). Subsequently, the materials were maintained for 12 hours under conditions of an ambient temperature of 10°C and an ambient humidity of 50%, and then changed to conditions of an ambient temperature of 40°C and an ambient humidity of 20%, maintaining these conditions for 12 hours. This environmental cycle test (10°C・50RH%×12hr⇔40°C・20RH%×12hr) was performed for six cycles, and the following items were evaluated.

[0110] "Step" is an indicator that shows the gap where the interlocking parts of flooring materials lift up when the joints of the flooring materials are fitted together. ◎: 0.1mm or less ○: More than 0.1mm and less than 0.3mm △: Over 0.3mm and under 0.5mm ×: Over 0.5mm

[0111] "Adhesive application misalignment" is an indicator of the linearity of the application area when adhesive is applied in a bead-like manner along the length of the flooring material. ◎: Left-right displacement is less than ±5mm ○: Lateral displacement of ±5mm or more but less than 10mm △: Lateral displacement of ±10mm or more but less than 20mm ×: Lateral displacement of ±20mm or more

[0112] "Adhesive leakage" is an indicator showing the amount of adhesive leakage from the edges of the foamed resin layer of the flooring material. ○: No visible overflow. △: Visible to the naked eye, but minor and inconspicuous. ×: Easily identifiable by visual inspection, with food protruding.

[0113] "Workability during assembly" ○: Easy to fit together ×: It takes time to align the mating parts or they cannot be mated.

[0114] "Flooring material peeling strength from subfloor" is an indicator of the adhesive strength when flooring material is peeled off the subfloor after six cycles of a cycle test are performed under the aforementioned environmental conditions (10℃・50RH%×12hr ⇔ 40℃・20RH%×12hr) following the installation of the flooring material onto the subfloor. ◎: The foamed resin layer that makes up the flooring material breaks down, and the flooring material also breaks when it is peeled off. ○: The foamed resin layer that makes up the flooring material undergoes material failure, but no breakage of the flooring material is observed when the flooring material is peeled off. ×: The foamed resin layer that makes up the flooring does not break down, making it easy to peel off the flooring.

[0115] "comprehensive evaluation" ◎: The evaluation items "level difference," "adhesive application misalignment," and "strength of peeling flooring material from subfloor" all received a ◎ rating, and "adhesive overflow" and "workability during fitting" both received a ○ rating. ○: Products that receive a ◎ rating for both evaluation items "level difference" and "adhesive application misalignment," a ○ rating or higher for "strength of peeling flooring material from subfloor," a △ rating or higher for "adhesive overflow," and a ○ rating for "workability during fitting." △: Products where either "level difference" or "adhesive application misalignment" is rated as ○, "strength of peeling flooring material from subfloor" is rated as ○ or higher, "adhesive overflow" is rated as △ or higher, and "workability during fitting" is rated as ○. ×: Items that receive an × rating in at least one of the above evaluation items.

[0116] (Example 1) A 2μm thick stone-patterned layer was formed on a colored polypropylene resin film (thickness: 60μm, color: white) using gravure printing with an ink composition (acrylic urethane-based). Next, a 2μm thick adhesive layer was formed using a urethane-based dry laminating adhesive, and a transparent polypropylene resin film (thickness: 80μm) was dry-laminated onto the surface of the patterned layer.

[0117] Subsequently, a 1 μm thick primer layer was formed on the surface of the transparent polypropylene resin film using a two-component curing urethane resin. Then, an electron beam curable resin composition (acrylate-based) was applied to the surface of the primer layer by gravure printing at a rate of 15 g / m². 2 The coating was applied to form a film, and the film was crosslinked and hardened by irradiation with an electron beam to form a surface protective layer (thickness: 15 μm), and a decorative sheet (thickness: 160 μm) was fabricated to serve as the decorative layer.

[0118] Furthermore, a vinyl chloride resin sheet containing 69% by mass of calcium carbonate (tensile modulus: 6,500 MPa, thickness: 2.7 mm) was prepared as a non-foaming resin layer, and the surface of the non-foaming resin layer and the back surface of the decorative sheet were bonded together by dry lamination using a urethane-based dry laminating adhesive, so that they faced each other.

[0119] Next, a foamed resin layer (foaming ratio: 10 times, compressive modulus: 43 MPa, 10% compressive modulus: 1.4 MPa, thickness: 9 mm) was prepared by the bead method using EPS resin (foaming agent: butane (7 parts by mass per 100 parts by mass of polystyrene resin), plasticizer: liquid paraffin (0.15 parts by mass per 100 parts by mass of polystyrene resin)) as the foamed resin layer. An intermediate flooring material was then produced by bonding the back surface of the non-foamed resin layer, to which a decorative sheet had been attached, to the front surface of the foamed resin layer using a PUR-based adhesive.

[0120] Next, a flooring material with a tongue and groove (male and female parts) was manufactured by processing the foamed resin layer and the non-foamed resin layer using a tenoner machine. At that time, the ends in the width direction of the intermediate flooring material were clamped with a pair of 25 mm wide pressure rolls.

[0121] The obtained flooring material had a thickness of 9.4 mm in the center of the foamed resin layer in the width direction, with a recess depth of 1.9 mm (ratio of recess depth to thickness in the center of the foamed resin layer in the width direction: 20.2%), and a width dimension of 24 mm for the recessed section. Using the obtained flooring material, a modified silicone adhesive (Floor Lock FL110L, manufactured by Cemedyne Co., Ltd.) was applied in a bead-like manner to the recessed section of the foamed resin layer, with an application width of 17 mm in four places (two places in each direction of length and width). The flooring material was then placed on the surface of a separately prepared base material (particle board) and a construction quality evaluation was conducted. The evaluation results are shown in Table 1.

[0122] (Example 2) Except for applying a modified silicone adhesive in a bead-like manner to the recessed areas of the foamed resin layer with a width of 22 mm in four places (two places in each direction of length and width), the substrate was placed on the surface of the substrate in the same manner as in Example 1, and the construction quality was evaluated. The evaluation results are shown in Table 1.

[0123] (Example 3) An EPS-based foamed resin layer with a foaming ratio of 15 times, a compressive modulus of 23 MPa, a 10% compressive modulus of 0.8 MPa, and a thickness of 9 mm was prepared. An intermediate flooring material was manufactured by bonding the back surface of the non-foamed resin layer to which the decorative sheet of Example 1 was attached with a PUR-based adhesive to the front surface of the foamed resin layer.

[0124] Subsequently, flooring material with a tongue and groove (male and female parts) was manufactured by processing the foamed resin layer and the non-foamed resin layer using a tenoner machine. At that time, the ends in the width direction of the intermediate flooring material were clamped with a pair of 25 mm wide pressure rolls.

[0125] The obtained flooring material had a thickness of 9.4 mm in the center of the foamed resin layer in the width direction, with a recess depth of 2.7 mm in the stepped section (ratio of recess depth to thickness of the foamed resin layer in the width direction in the center direction: 28.7%), and a width dimension of 24 mm in the stepped section. Otherwise, the material was placed on the surface of the substrate and the construction quality was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0126] (Example 4) An EPS-based foamed resin layer with a foaming ratio of 8, a compressive modulus of 60 MPa, a 10% compressive modulus of 2.0 MPa, and a thickness of 9 mm was prepared. An intermediate flooring material was manufactured by bonding the back surface of the non-foamed resin layer to which the decorative sheet of Example 1 was attached with a PUR-based adhesive to the front surface of the foamed resin layer.

[0127] Subsequently, flooring material with a tongue and groove (male and female parts) was manufactured by processing the foamed resin layer and the non-foamed resin layer using a tenoner machine. At that time, the ends in the width direction of the intermediate flooring material were clamped with a pair of 25 mm wide pressure rolls.

[0128] The obtained flooring material had a thickness of 9.4 mm in the center of the foamed resin layer in the width direction, with a recess depth of 0.7 mm in the stepped section (ratio of recess depth to thickness of the foamed resin layer in the width direction in the center direction: 7.4%), and a width dimension of 23 mm in the stepped section. Otherwise, the material was placed on the surface of the substrate and the construction quality was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0129] (Comparative Example 1) An EPS-based foamed resin layer with a foaming ratio of 5, a compressive modulus of 118 MPa, a 10% compressive modulus of 4.0 MPa, and a thickness of 9 mm was prepared. An intermediate flooring material was manufactured by bonding the back surface of the non-foamed resin layer to which the decorative sheet of Example 1 was attached with a PUR-based adhesive to the front surface of the foamed resin layer.

[0130] Subsequently, flooring material with a tongue and groove (male and female parts) was manufactured by processing the foamed resin layer and the non-foamed resin layer using a tenoner machine. At that time, the ends in the width direction of the intermediate flooring material were clamped with a pair of 25 mm wide pressure rolls.

[0131] The obtained flooring material had a thickness of 9.4 mm in the width direction at the center of the foamed resin layer, while the thickness at the edges in the width direction was also 9.4 mm, and no recessed steps were formed. Otherwise, the material was placed on the surface of the substrate and the construction quality was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0132] (summary) In Examples 1-3, it was found that the step difference at the interlocking part of the flooring material, misalignment of adhesive application, and adhesive overflow to the edges in the width direction of the flooring material were suppressed compared to Comparative Example 1. In Example 4, it was found that the suppression of adhesive overflow to the edges in the width direction of the flooring material was somewhat insufficient. In other words, it was found that by forming recessed steps with an appropriate amount of recess on both ends in the width direction of the back surface of the foamed resin layer, and applying the adhesive in a bead shape to these recessed steps with an appropriate application width, the step difference at the flooring material, misalignment of adhesive application, and adhesive overflow to the edges in the width direction of the flooring material are suppressed, while improving the workability of the floor structure. The appropriate application width is 15mm to 40mm. [Table 1] [Explanation of Symbols]

[0133] 10 Flooring 10A Intermediate 12. Subflooring materials 14 Floor structure 16 Foamed resin layer 18 Non-foamed resin layer 20 Decorative layers 22 Base resin layer 24 pattern layers 26 Transparent resin layer 28 Adhesive layer 30 Surface protective layer 32 Male Fruit Section (Fruit Section) 34. Female fruit part (fruit part) 36 Concave step 38 cutters 40 cutters 42 Pressure Roll (Clamping Member) B Adhesive BC adhesive layer

Claims

1. A method for manufacturing a rectangular flooring material having a foamed resin layer and a non-foamed resin layer laminated on the surface side of the foamed resin layer, An intermediate product formation step is to form an intermediate product of the flooring material by bonding the surface of the foamed resin layer and the back surface of the non-foamed resin layer, A process for forming a solid portion on the end face of the intermediate product in the width direction and / or length direction by actual machining, The process includes forming recessed steps on both ends in the width direction of the back surface of the foamed resin layer in the intermediate product, A method for manufacturing flooring, wherein in the step of forming the recessed portion, the width dimension of the recessed portion is set to 20 mm to 40 mm, and the depth of the recess of the recessed portion is set to 8% to 30% of the thickness of the central part in the width direction of the foamed resin layer.

2. The method for manufacturing a flooring material according to claim 1, wherein in the step of forming the recessed step, the recessed step is formed by compression molding both ends in the width direction of the foamed resin layer in the intermediate product.

3. The method for manufacturing a flooring material according to claim 1, wherein in the step of forming the recessed step, when performing actual processing on the end face of the intermediate product, the widthwise ends of the intermediate product are clamped by a pair of clamping members, thereby compressing and molding the widthwise ends of the foamed resin layer in the intermediate product to form the recessed step.

4. A flooring material formed in a rectangular shape, A foamed resin layer, The foamed resin layer has a non-foamed resin layer laminated on the surface side, A solid portion is formed on the end faces in the width direction and / or length direction, and recessed steps are formed on both ends in the width direction on the back surface of the foamed resin layer. The width dimension of the recessed step is 20 mm to 40 mm, and the depth of the recessed step is 8% to 30% of the thickness of the central part in the width direction of the foamed resin layer, in a flooring material.

5. The flooring material according to claim 4, wherein the 10% compressive strength of the foamed resin layer is 1.5 MPa or less.

6. A method for constructing a floor structure on a subfloor using the flooring material described in claim 4, The application step involves applying adhesive in a bead-like manner to the recessed portion of the foamed resin layer in the flooring material, A method for constructing a floor structure, comprising: a direct bonding step of directly bonding a plurality of floor materials to a floor base material by the adhesive action of the adhesive, while fitting together the joints of adjacent floor materials in the width direction and / or length direction of the floor materials.

7. The method for constructing a floor structure according to claim 6, wherein in the coating step, the width of the adhesive applied to the recessed portion of the foamed resin layer in the floor material is 15 mm to 35 mm.

8. The method for constructing a floor structure according to claim 6 or 7, wherein in the direct bonding step, the floor material is directly bonded to the subfloor material solely by the adhesive action of the adhesive.

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