Resin flooring material and method for manufacturing resin flooring material

Abstract

We provide resin flooring that can create a natural terrazzo pattern. [Solution] The resin flooring material 1 comprises a main body layer 2 having an aggregated portion 5 in which a plurality of vinyl chloride resin particles 7 with a particle size of 20 μm to 300 μm are aggregated, and a plurality of resin flakes 6 fixed to the aggregated portion 5. When the main body layer 2 is divided into an upper layer 2A including the surface of the main body layer 2 and a lower layer 2B including the back surface of the main body layer 2, the resin flakes 6 are contained in the upper layer 2A and the lower layer 2B of the main body layer 2, respectively.

Description

[Technical Field]

[0001] The present invention relates to a resin flooring material having a terrazzo pattern and a method for producing the same. [Background Art]

[0002] Conventionally, resin interior materials having a so-called terrazzo pattern are known as interior materials for buildings such as floor materials, wall materials and ceiling materials of buildings. The terrazzo pattern is a pattern having a marble-like appearance in which crushed natural stone such as marble is sprinkled in an aggregate such as cement or resin. A resin flooring material having a terrazzo pattern can be said to be a flooring material in which the terrazzo pattern is artificially reproduced with a resin material. For example, Patent Document 1 discloses a method for obtaining a synthetic resin plate having a terrazzo pattern by crushing a colored vinyl chloride resin sheet, collecting the crushed product, and rolling or pressing the same. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 3842420 [Summary of the Invention]

[0004] However, in the resin plate obtained by the method of Patent Document 1, it is necessary to bond the crushed products to each other with sufficient strength in order to ensure the required strength. As a general method for increasing the bonding strength between crushed products, it is conceivable to increase the heating temperature and pressure when rolling the crushed product to enhance the fusion of the vinyl chloride resin. However, when the fusion of the vinyl chloride resin is enhanced, the exposed pattern becomes blurred due to the resin fusion or becomes close to plain (unpatterned). In addition, chips are buried in the vinyl chloride paste resin, making it difficult to express a natural three-dimensional appearance. Furthermore, since the surface of the flooring material wears over time, when the chips are buried in the vinyl chloride paste resin, some portions where the terrazzo pattern disappears may occur. [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a resin flooring material that can express a natural-looking terrazzo pattern and in which the terrazzo pattern does not easily disappear over time. [Means for solving the problem]

[0006] The first embodiment of the resin flooring material comprises a main body layer having aggregated portions formed by the aggregation of multiple vinyl chloride resin particles with a particle size of 20 μm to 300 μm, and multiple resin flakes fixed to the aggregated portions, wherein when the main body layer is divided into an upper layer including the surface of the main body layer and a lower layer including the back surface of the main body layer, the resin flakes are contained in the upper and lower layers of the main body layer, respectively.

[0007] The second embodiment of the resin flooring material is the resin flooring material of the first embodiment, wherein the upper layer of the main body layer includes a resin flake having a portion exposed on the surface of the main body layer. The third embodiment of the resin flooring material includes, in the second embodiment of the resin flooring material, a resin flake that is parallel to the surface of the main body layer or inclined at an angle of 30 degrees or less with respect to the surface of the main body layer.

[0008] The fourth embodiment relates to a method for manufacturing a resin flooring material, the method comprising: a layered material manufacturing step of forming a layered material containing a plurality of vinyl chloride resin particles and resin flakes with a particle size of 20 μm to 300 μm on a substrate; and a sheet manufacturing step of manufacturing a sheet by heating the layered material, wherein the layered material manufacturing step includes scattering the vinyl chloride resin particles and resin flakes. [Effects of the Invention]

[0009] The resin flooring material displays a natural-looking terrazzo pattern, and furthermore, it prevents the terrazzo pattern from disappearing even as the main layer wears down over time. [Brief explanation of the drawing]

[0010] [Figure 1]A partially omitted plan view of the resin flooring material according to one embodiment. [Figure 2] A schematic cross-sectional view taken along line II-II in FIG. 1. [Figure 3] A schematic cross-sectional view of a modified resin flooring material of the same embodiment. [Figure 4] A schematic cross-sectional view of a resin flooring material according to a further modified example. [Figure 5] A schematic cross-sectional view of a resin flooring material according to a further modified example. [Figure 6] A schematic cross-sectional view of a resin flooring material according to a further modified example. [Figure 7] An enlarged plan view of the surface of the resin flooring material (enlarged plan view of section VII in FIG. 1). [Figure 8] (a) is an enlarged cross-sectional view taken along line VIII-VIII in FIG. 7, and (b) is an enlarged cross-sectional view showing another example when cut at the same position. [Figure 9] An enlarged cross-sectional view taken along line IX-IX in FIG. 7. [Figure 10] An enlarged cross-sectional view taken along line X-X in FIG. 7. [Figure 11] A reference cross-sectional view enlarging the circled section XI in FIG. 8(a). [Figure 12] A perspective view of a resin flake. [Figure 13] A reference front view of vinyl chloride resin particles to which filler fine particles adhere. [Figure 14] A schematic diagram of the manufacturing apparatus according to the first embodiment. [Figure 15] A schematic diagram of the manufacturing apparatus according to the first example of the second embodiment. [Figure 16] A schematic diagram of the manufacturing apparatus according to the second example of the second embodiment. [Figure 17] A schematic diagram of the manufacturing apparatus according to the third example of the second embodiment. DESCRIPTION OF EMBODIMENTS

[0011] Hereinafter, the present invention will be described with appropriate reference to the drawings. In this specification, planar view refers to viewing from a direction orthogonal to the surface of the resin flooring material, and the shape in planar view refers to the shape when viewed from that direction. In this specification, a numerical range expressed as "lower limit X to upper limit Y" means a range greater than or equal to lower limit X and less than or equal to upper limit Y. If multiple such numerical ranges are listed separately, any lower limit and any upper limit can be selected to set "any lower limit to any upper limit". Please note that the dimensions, such as the thickness of layers, particle size, and various shapes shown in each figure may differ from those of the actual objects.

[0012] <Resin flooring> In Figure 1, the resin flooring material 1 has a main body layer 2. The resin flooring material 1 of this embodiment may be formed in the shape of a long strip, as shown in Figure 1, or, although not specifically shown, may be formed in the shape of a single sheet. The long strip refers to a roughly rectangular shape in plan view, where the length in one direction is sufficiently longer than the length in the other direction. For example, the long strip resin flooring material 1 has a length of 1000 mm to 4000 mm in the first direction and a length of 5 m or more in the second direction, preferably 10 m or more in the second direction. The first direction is the direction perpendicular to the second direction. The long strip resin flooring material 1 is also called a floor sheet. The aforementioned "sheet-like" shape refers to a predetermined shape, such as a roughly square shape in plan view, and generally means a shape that can be stacked for storage and transport. Examples of sheet-like resin flooring materials include a roughly rectangular shape with a length of 200 mm to 1000 mm in the first direction and a length of 200 mm to 1000 mm in the second direction. Sheet-like resin flooring materials are also called floor tiles.

[0013] The resin flooring material 1 does not necessarily have to be flexible, but it is preferably flexible. The degree of flexibility is such that, for example, the back side of the resin flooring material 1 can be rolled up around a core with a diameter of 10 cm.

[0014] Figure 2 shows a layered resin flooring material 1 according to one embodiment, Figure 3 shows a layered resin flooring material 1 according to a modified example, Figure 4 shows a layered resin flooring material 1 according to yet another modified example, and Figure 5 shows a layered resin flooring material 1 according to yet another modified example. Figure 6 shows a layered resin flooring material 1 according to yet another modified example. The plan views of the resin flooring material 1 for each modified example are the same as in Figure 1 and are therefore omitted. In Figure 2, one example of resin flooring material 1 consists only of the main layer 2. In Figure 3, the resin flooring material 1 of the other example has, in order from the back side, a main layer 2 and a protective layer 21 that protects the surface of the main layer 2. In this case, the surface of the resin flooring material 1 is made up of the surface of the protective layer 21. In Figure 4, the resin flooring material 1 of the other example has, in order from the surface side, a main layer 2, a fiber reinforcement layer 3, and a back layer 4. Although not specifically shown, a fiber reinforcement layer made of the same or a different material as the fiber reinforcement layer 3 provided between the main layer 2 and the back layer 4 may be provided on the back surface of the back layer 4 of the resin flooring material 1 in Figure 4. In Figure 5, the resin flooring material 1 of the other example has, in order from the surface side, a main layer 2, a back layer 4, and a fiber reinforcement layer 3. Although not specifically shown, a back layer made of the same or a different material as the back layer 4 provided on the back surface of the main layer 2 may be provided on the back surface of the fiber reinforcement layer 3 of the resin flooring material 1 in Figure 5. In Figure 6, the resin flooring material 1 of another example has, in order from the surface side, a main layer 2 and a back layer 4. In the resin flooring material 1 shown in Figures 4 to 6, the back layer 4 is represented as a single-layer structure, but these back layers 4 may also be a laminated structure of two or more layers (not shown). Furthermore, a protective layer (not shown) that protects the surface of the main layer 2 may be provided for any of the resin flooring material 1 shown in Figures 4 to 6. Preferably, the resin flooring material 1 of the present invention has a single-layer structure (consisting only of the main layer 2) as shown in Figure 2, or a two-layer structure having a protective layer 21 and a main layer 2 as shown in Figure 3. The thickness of the main body layer 2 is not particularly limited, and is, for example, 0.5 mm to 8 mm, preferably 1 mm to 5 mm. The thickness of the protective layer 21 is not particularly limited, and is, for example, 3 μm to 100 μm, preferably 5 μm to 50 μm.

[0015] (Main layer) Figure 7 is a plan view of an enlarged portion of the surface of the resin flooring material 1, and Figures 8 to 10 are enlarged cross-sectional views obtained by cutting the resin flooring material 1 at a predetermined location. Figure 11 is a reference view of an enlarged portion of the aggregated area 5. Although Figures 8 to 10 show a cross-section of the resin flooring material 1 consisting only of the main body layer 2, as described above, the resin flooring material 1 of the present invention may have a protective layer or the like laminated on the main body layer 2.

[0016] The main body layer 2 has an aggregated portion 5 in which multiple vinyl chloride resin particles with a particle size of 20 μm to 300 μm are aggregated, and multiple resin flakes 6 that are scattered in and fixed to the aggregated portion 5. The main body layer 2 is composed of layers of aggregated portions 5, with resin flakes 6 firmly fixed to various points within these aggregated portions 5. Therefore, the main component of the main body layer 2 is the aggregated portions 5.

[0017] Referring to Figure 11, the vinyl chloride resin particles 7 constituting the aggregated portion 5 include some that are roughly spherical or roughly elliptical, but most have an irregular three-dimensional shape. Since most of the aggregated vinyl chloride resin particles 7 have an irregular three-dimensional shape, their particle size is determined as follows: The aggregated portion 5 is cut in the thickness direction, and an SEM image (60x magnification) is taken at an arbitrary location on the cut surface. An area of ​​1500 μm along the transverse direction and 1500 μm along the vertical direction is arbitrarily extracted from the image. Ten vinyl chloride resin particles 7 within the extracted image area that are relatively close to a circular shape are selected, and the maximum length of these particles is measured. The average of the maximum lengths of these ten particles is taken as the particle size of the vinyl chloride resin particles 7 constituting the aggregated portion 5.

[0018] Furthermore, the aggregated portion 5 may have cavities 58 inside. The cavities 58 consist of a closed space surrounded by a plurality of vinyl chloride resin particles 7, or a closed space surrounded by a plurality of vinyl chloride resin particles 7 and resin flakes 6. The size and number of cavities 58 are not particularly limited, but if they are too large or too numerous, the strength of the aggregated portion 5 will decrease, so the size and number of cavities 58 are controlled with this in mind. The three-dimensional shape of the cavities 58 is not particularly limited, but they are often approximately spherical. For example, the size of the cavities 58 is 10 μm to 300 μm, and the number of cavities 58 is, for example, 2 to 50 in the range of 1000 μm × 1000 μm. The size of the cavities 58 can be measured in the same way as the method for determining the particle size of the vinyl chloride resin particles 7. That is, in the explanation of the method for determining the particle size of the vinyl chloride resin particles 7, the size of the cavities 58 can be determined by replacing "vinyl chloride resin particles 7" with "cavities 58". The number of cavities 58 is determined by cutting the aggregated portion 5 in the thickness direction, taking an SEM image (60x magnification) of any point on the cut surface, and arbitrarily extracting a range of 1000 μm in the horizontal direction and 1000 μm in the vertical direction from that image, and counting the number of cavities within that range.

[0019] The main body layer 2 contains multiple resin flakes 6 randomly dispersed, and each resin flake 6 is integrally bonded to the aggregated portion 5. When the main body layer 2 is divided into an upper layer 2A including the surface of the main body layer 2 and a lower layer 2B including the back surface of the main body layer 2, the resin flakes 6 are dispersed in multiples in each of the upper layer 2A and the lower layer 2B. Referring to Figures 8 to 10, the upper layer 2A of the main body layer 2 refers to the area from the surface of the main body layer 2 to half the thickness of the main body layer 2. The lower layer 2B of the main body layer 2 is the area in the thickness direction of the main body layer 2 excluding the upper layer 2A, and refers to the area from the back surface of the main body layer 2 to half the thickness of the main body layer 2.

[0020] As shown in Figure 7, the presence of resin flakes 6 can be seen with the naked eye when the surface of the main body layer 2 is viewed. Visually, the resin flakes 6 present in the aggregated portion 5 look like large stones, so the resin flooring material 1 of the present invention has a terrazzo pattern appearance as a whole. In Figure 7, the portion of the resin flake 6 shown by a solid line is exposed on the surface of the main body layer 2. "Exposed" means being visible on the surface. The exposed portion of the resin flake 6 constitutes the surface of the main body layer 2. The portion of the resin flake 6 shown by a dashed line is visible from the surface of the main body layer 2, but the aggregated portion 5 covers it. As will be described later, resin flakes 6 are colored in various ways, but the visible resin flakes 6 have a different color from the aggregated portion 5.

[0021] Specifically, in Figure 7, the resin flake 6 denoted by reference numeral 6a is located in the upper layer 2A, and as shown in Figure 8, the entire surface of the resin flake 6(6a) is exposed. In Figure 7, the resin flake 6 denoted by reference numeral 6b is located in the upper layer 2A, and as shown in Figure 9, a portion of the surface of the resin flake 6(6b) is exposed, and the aggregated portion 5 covers a portion of the surface of the resin flake 6(6b). The resin flakes 6(6a) and 6(6b) are resin flakes that have a portion exposed on the surface of the main layer 2. Also, in Figure 7, the resin flake 6 denoted by reference numeral 6c is located in the upper layer 2A, and as shown in Figure 10, the resin flake 6(6c) is not exposed, and the aggregated portion 5 covers its entire surface. Hereinafter, the aggregated portion 5 covering the surface of the resin flake 6 of the upper layer 2A will be referred to as the "covering portion 51," and the portion of the resin flake 6 that is exposed will be referred to as the "exposed portion 61." The resin flake 6 covered by the covering portion 51, including the portion covered by the covering portion 51, is visible from the surface side of the main layer 2.

[0022] The resin flakes 6 present in the upper layer 2A are visible from the surface. The portion of the resin flakes 6 covered by the overlapping portion 51 appears to be further away than the exposed portion 61. Therefore, the presence of both exposed and non-exposed resin flakes 6 in the upper layer 2A gives it a three-dimensional terrazzo pattern appearance. The presence of the above three patterns of resin flakes 6(6a, 6b, 6c) in the upper layer 2A provides a resin flooring material 1 with a natural terrazzo pattern appearance. The number and arrangement of these three patterns of resin flakes 6(6a, 6b, 6c) in the planar direction are not particularly limited and are random. Printed terrazzo patterns give an unnatural impression because the pattern of the printing plate is repeated, but by randomizing the number and arrangement of the above three patterns of resin flakes 6(6a, 6b, 6c) in the planar direction, a natural terrazzo pattern can be expressed.

[0023] In the exposed portion 61 of the resin flake 6, for example, as shown in Figure 8(a), there is no relatively large step at the boundary between the resin flake 6 and the aggregated portion 5, and the surface from the surface of the resin flake 6 to the surface of the aggregated portion 5 is substantially flat. This state of having no relatively large step at the boundary means that the step cannot be detected or is only slightly felt when traced with a fingertip. Since the resin flooring material 1 is not a precision instrument, a slight step occurs at the boundary when viewed microscopically. Therefore, the statement that there is no step at the boundary between the resin flake 6 and the aggregated portion 5 as shown in Figure 8(a) means that such a microscopic step is not present. Furthermore, while there may be no steps at the boundaries between all exposed resin flakes 6 and aggregated portions 5, steps may exist at the boundaries between the exposed portions 61 of some resin flakes 6 and aggregated portions 5. For example, as shown in Figure 9, steps 615 may exist at the boundaries between the exposed portions 61 of some resin flakes 6 and aggregated portions 5. Note that Figure 9 shows the case where there are steps between partially exposed resin flakes 6 and aggregated portions 5, but for example, as shown in Figure 8(b), steps 615 may exist at the boundaries between some resin flakes 6 and aggregated portions 5 among resin flakes 6 whose entire surface is exposed. The microscopic steps are, for example, steps greater than 0 and less than 50 μm, and the steps 615 are, for example, steps of about 50 μm to 200 μm. Furthermore, the surface of the main body layer 2 may be embossed. Examples of embossing include fine matte embossing for a matte finish and relatively deep embossing to create a textured pattern. When embossing is applied, a step will be created on the surface of the main body layer 2 due to the irregularities of the embossing. However, it should be noted that the step caused by the embossing is different from the step at the boundary between the resin flake 6 and the aggregated portion 5. In other words, the step caused by the irregularities of the embossing does not necessarily occur at the boundary between the resin flake 6 and the aggregated portion 5.

[0024] Referring to Figures 8 to 10, resin flakes 6 are also embedded in the lower layer 2B. As the resin flooring material 1 is used, the surface will be worn down by the soles of feet and wheels, but because of the presence of resin flakes 6 in the lower layer 2B, the resin flakes 6 in the lower layer 2B will remain visible even when the upper layer 2A becomes thin. The number and arrangement of the resin flakes 6 in the lower layer 2B are not particularly limited and are random. Because the number and arrangement of the resin flakes 6 in the lower layer 2B are random, even when the resin flakes 6 in the lower layer 2B become visible due to wear of the main layer 2, it maintains a natural terrazzo pattern appearance.

[0025] As shown in Figure 8, the resin flakes 6 of the lower layer 2B may not overlap the resin flakes 6 present in the upper layer 2A in the thickness direction, or, as shown in Figures 9 and 10, they may partially overlap the resin flakes 6 present in the upper layer 2A in the thickness direction. Furthermore, some of the resin flakes 6 embedded in the main body layer 2 are entirely contained within the lower layer 2B, while others, as shown in Figures 9 and 10, are contained across both the lower layer 2B and the upper layer 2A. Conceptually, resin flakes 6 that exist across both the lower layer 2B and the upper layer 2A are divided at the boundary between the lower layer 2B and the upper layer 2A, and the portions corresponding to this division are contained within the lower layer 2B and the upper layer 2A, respectively.

[0026] Most of the resin flakes 6 are contained in the main layer 2 in a state parallel to the surface of the main layer 2 or inclined at an angle of 30 degrees or less relative to the surface of the main layer 2. This state allows the entire surface of the resin flakes 6 to be visible from the surface of the main layer 2, making the resin flakes 6 appear like stones. However, since the resin flooring material 1 is not a precision instrument, some of the resin flakes 6 may be contained perpendicular to the surface of the main layer 2 or inclined at an angle greater than 30 degrees relative to the surface of the main layer 2. The amount of resin flakes 6 contained in the main layer 2 in a state parallel to the surface of the main layer 2 or inclined at an angle of 30 degrees or less relative to the surface of the main layer 2 is 70% by weight or more, preferably 80% or more, when the total amount of resin flakes 6 is considered 100% by weight.

[0027] The number of resin flakes 6 in the upper layer 2A and the number of resin flakes 6 in the lower layer 2B may be approximately the same, but preferably, the amount of resin flakes 6 in the upper layer 2A is greater than the amount of resin flakes 6 in the lower layer 2B. The resin flooring material 1 wears down from the upper layer 2A during use, but generally, it is rare for it to be used until the entire lower layer 2B is worn away. By including more resin flakes 6 in the upper layer 2A, it is possible to provide a resin flooring material 1 in which the terrazzo pattern is less likely to disappear over time. The amount of resin flakes 6 contained in the upper layer 2A and the amount of resin flakes 6 contained in the lower layer 2B shall be determined as follows: The main layer 2 is cut in the thickness direction, and an SEM image (60x magnification) is taken at any point on the cut surface, and a 50mm range is arbitrarily extracted from the image along the plane direction of the main layer 2. The extracted image is divided into two equal parts in the thickness direction to distinguish between the upper layer 2A and the lower layer 2B. The sum of the areas of the resin flakes 6 in the image of the upper layer 2A shall be taken as the amount of resin flakes 6 contained in the upper layer 2A, and the sum of the areas of the resin flakes 6 in the image of the lower layer 2B shall be taken as the amount of resin flakes 6 contained in the lower layer 2B. Since the resin flakes 6 are distributed randomly, three arbitrary locations within a 50mm range along the plane direction of the main layer 2 shall be extracted, the area of ​​the resin flakes 6 in each location shall be measured, and the average value shall be adopted.

[0028] (agglomeration part) As described above, the aggregated portion 5 is composed of a layer of aggregated polyvinyl chloride resin particles 7 with a particle size of 20 μm to 300 μm. The presence of resin flakes 6 within the multiple polyvinyl chloride resin particles 7 with a particle size of 20 μm to 300 μm makes it possible to create a deep, natural-looking terrazzo pattern. The vinyl chloride resin particles 7 are colored to a desired color by the addition of a coloring agent. However, vinyl chloride resin particles 7 without a coloring agent may also be used. Vinyl chloride resin particles 7 without a coloring agent are white or milky white due to the filler, and vinyl chloride resin particles 7 without both a coloring agent and a filler are colorless, transparent or translucent. In other words, from the standpoint of color, the vinyl chloride resin particles 7 include (1-1) vinyl chloride resin particles colored in any single color (hereinafter referred to as monochromatic particles), (1-2) patterned vinyl chloride resin particles colored in any two or more colors (hereinafter referred to as multichromatic particles), (1-3) colorless, transparent or translucent vinyl chloride resin particles (hereinafter referred to as transparent particles), and (1-4) colorless, transparent or translucent vinyl chloride resin particles colored in any one or more colors (hereinafter referred to as composite particles). At least one type of vinyl chloride resin particle is used from among these. Examples of the multiple vinyl chloride resin particles 7 include (a-1) any of monochromatic particles, multicolored particles, transparent particles, or composite particles, (a-2) two or three types selected from monochromatic particles, multicolored particles, transparent particles, and composite particles, (a-3) two or more monochromatic particles with different colors from each other, (a-4) two or more multicolored particles with different colors from each other, and (a-5) one monochromatic particle or two or more monochromatic particles with different colors from each other and one multicolored particle or two or more multicolored particles with different colors from each other. The vinyl chloride resin particles 7 may be those with filler fine particles scattered on their surface, or they may not have filler fine particles scattered on their surface. As the former, vinyl chloride resin particles with filler fine particles scattered on their surface can be those disclosed in Patent Document 1 (JP 2021-046777 A). By using vinyl chloride resin particles with filler fine particles scattered on their surface, aggregated portions 5 having an appearance like sandy ground or fine sand scattered on it can be easily formed.

[0029] Specifically, in the aggregated portion 5, which is composed of polyvinyl chloride resin particles 7 with filler microparticles scattered on its surface, the filler microparticles become concentrated between adjacent polyvinyl chloride resin particles 7. When viewed as a whole, the aggregated portion 5 appears as a state where the filler microparticles are scattered. In other words, it is a state in which parts containing polyvinyl chloride resin particles 7 and parts containing aggregated filler microparticles are mixed together. Such an aggregated portion 5 takes on an appearance with a sandy texture, as if fine sand had been scattered.

[0030] Furthermore, when manufacturing the resin flooring material 1, various colors of vinyl chloride resin particles (in this paragraph, this refers to vinyl chloride resin particles used in the manufacturing of the flooring material, meaning vinyl chloride resin particles as raw materials) may be prepared, and two or more types of vinyl chloride resin particles may be selected from them. Preferably, five types of vinyl chloride resin particles with different colors (for example, black, white, magenta, cyan, and yellow) may be prepared in advance, and any aggregated parts 5 can be created by selecting at least two types of vinyl chloride resin particles from them. Since the vinyl chloride resin particles exhibiting each color are not melted during manufacturing, the colors do not completely mix, and each vinyl chloride resin particle contributes to the expression of a sand-like pattern, thereby forming a resin flooring material 1 having aggregated parts 5 of various colors macroscopically. For example, by primarily using magenta and cyan vinyl chloride resin particles from the five types mentioned above, a resin flooring material 1 having aggregated areas 5 with a dark blue sand-like pattern when viewed macroscopically can be produced. Similarly, by primarily using cyan and yellow raw material particles A, a resin flooring material 1 having aggregated areas 5 with a green sand-like pattern when viewed macroscopically can be produced. In other words, by selecting several of the five types of vinyl chloride resin particles and mixing them in predetermined proportions, a wide variety of sand-like patterns can be expressed using the principle of primary colors. While magenta, cyan, and yellow are preferred as the primary colors, red, blue, and green may also be used.

[0031] Furthermore, even if the vinyl chloride resin particles 7 do not contain dispersed filler fine particles, or if they are any of the vinyl chloride resin particles 7 described in (a-2) to (a-5) above, aggregated portions 5 having a sand-like appearance can be formed. Because resin flakes 6 are dispersed within the aggregated areas 5 with a sand-like pattern, the resin flakes 6 appear to be embedded in the sand, giving the impression of natural stone. This provides a resin flooring material with a natural stone-like appearance.

[0032] When vinyl chloride resin particles 7, which have filler fine particles scattered on their surface, are used, the filler fine particles 72 tend to accumulate and adhere to the recesses (gaps) formed between adjacent vinyl chloride resin particles 7 in the aggregated portion 5. In Figure 11, areas where the filler fine particles 72 tend to accumulate and adhere are indicated by diagonal lines. Examples of filler fine particles 72 include inorganic fillers such as calcium carbonate, titanium dioxide, calcium oxide, barium carbonate, magnesium hydroxide, aluminum hydroxide, clay, talc, and mica, and preferably contain calcium carbonate. Furthermore, the size of the filler particles 72 is considerably smaller than the vinyl chloride resin particles 7. In the aggregated portion 5, multiple vinyl chloride resin particles 7 are adjacent to each other, and adjacent vinyl chloride resin particles 7 are joined together to form a layer. Note that in Figure 11, the spaces between adjacent vinyl chloride resin particles 7 are clearly shown with solid lines, but it should be noted that adjacent vinyl chloride resin particles 7 may not have a clear boundary due to joining (fusion).

[0033] The vinyl chloride resin particles 7 contain a vinyl chloride resin and a plasticizer, and optionally contain fillers and / or any suitable additives. Vinyl chloride resins include polymers formed by polymerizing at least a monomer of vinyl chloride (chloroethylene). Vinyl chloride resins include not only homopolymers formed by the homopolymerization of chloroethylene, but also copolymers of chloroethylene and other monomers that can copolymerize with chloroethylene, mixtures of homopolymers and copolymers, and mixtures of two or more copolymers. A mixture refers to a polymer in which homopolymers and copolymers, or copolymers, are kneaded together without substantially polymerization. Examples of vinyl chloride resins include vinyl chloride polymers (homopolymers); chlorinated vinyl chloride; partially crosslinked vinyl chloride; copolymers containing vinyl chloride, such as vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, vinyl chloride-isobutylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-butadiene copolymer, vinyl chloride-isoprene copolymer, and vinyl chloride-chlorinated propylene copolymer; mixtures of homopolymers and one or more copolymers; and mixtures of two or more copolymers. Preferably, a vinyl chloride polymer (homopolymer) is used. These vinyl chloride resins may be used individually or in combination of two or more types. Furthermore, while virgin vinyl chloride resins are used, recycled materials may be used as needed, or a mixture of virgin and recycled materials may be used.

[0034] The vinyl chloride polymer (homopolymer) can be one produced by emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization, etc., and it is preferable to use a paste vinyl chloride resin and / or a suspension vinyl chloride resin. The paste vinyl chloride resin is, for example, a paste-like vinyl chloride resin obtained by emulsion polymerization, and its viscosity can be adjusted as appropriate with a plasticizer. The average degree of polymerization of the paste vinyl chloride resin is preferably around 1000 to 2000. The suspension vinyl chloride resin is, for example, a vinyl chloride resin obtained by suspension polymerization. The average degree of polymerization of the suspension vinyl chloride resin is preferably around 700 to 1500, more preferably around 700 to 1100, and even more preferably around 700 to 1000.

[0035] Plasticizers are primarily added to improve the flexibility of vinyl chloride resins. Examples of plasticizers include polyester plasticizers, glycerin plasticizers, polycarboxylic acid ester plasticizers, and polyalkylene glycol plasticizers. Fillers are primarily added to improve processability and physical properties. Examples of fillers include those mentioned above. The aforementioned additives can be those that are conventionally known, such as colorants, flame retardants, stabilizers, antioxidants, lubricants, antibacterial agents, antifungal agents, and surfactants.

[0036] (resin flake) Figure 12 is a perspective view of an exemplary resin flake 6. The plan view shape of the resin flake 6 is, for example, irregular. That is, the size and shape of multiple resin flakes 6 vary and cannot be specified. The size of the resin flake 6 is, for example, 10 mm. 2 ~2000mm 2 It is approximately, preferably 50 mm 2 ~1500mm 2 This is the extent of the size. Resin flakes 6 of this size are obtained by removing the fine powder described later. In addition to the resin flakes 6 within the above size range, a small amount of the fine powder described later may also be included. The thickness of the resin flakes 6 is not particularly limited, for example, 0.1 mm to 2 mm, preferably 0.2 mm to 1.5 mm. If the thickness of the resin flakes 6 is above the lower limit, when the resin flakes 6 are scattered during the manufacture of the flooring material described later, the resin flakes 6 will be able to align well on the surface of the PVC layer. If the thickness of the resin flakes 6 is below the upper limit, the planar shape of the resin flakes 6 will be maintained, and heat will be applied more easily, allowing for good manufacture of the flooring material and the formation of a natural-looking terrazzo pattern. From a color perspective, the resin flakes 6 include (2-1) resin flakes colored in any single color (hereinafter referred to as monochromatic flakes), (2-2) patterned resin flakes colored in any two or more colors (hereinafter referred to as multichromatic flakes), (2-3) colorless, transparent or translucent resin flakes (hereinafter referred to as transparent flakes), and (2-4) colorless, transparent or translucent resin flakes with any one or more colors added (hereinafter referred to as composite flakes). At least one type of resin flake is used from among these. The multiple resin flakes 6 can be, for example, (b-1) any of a single-color flake, a multi-color flake, a transparent flake, or a composite flake; (b-2) two or three types selected from single-color flakes, multi-color flakes, transparent flakes, and composite flakes; (b-3) two or more single-color flakes with different colors; (b-4) two or more multi-color flakes with different colors; (b-5) one single-color flake or two or more single-color flakes with different colors and one multi-color flake or two or more multi-color flakes with different colors. It is preferable that the resin flakes 6 be any of (b-2) to (b-5) as they have the appearance of a natural terrazzo pattern due to the inclusion of various stone patterns. The resin flakes 6 are formed from a resin material such as a vinyl chloride resin. It is preferable that the resin flakes 6 be formed from a resin material primarily composed of vinyl chloride resin, as they bond firmly to the aggregated portion 5. As the vinyl chloride resin for the resin flakes 6, those exemplified in the vinyl chloride resin particles 7 can be used. By making both the aggregated portion 5 and the resin flakes 6 primarily composed of vinyl chloride resin, they bond firmly, eliminating the need to fuse them at high temperatures. This results in a clearly defined boundary between the two, creating a more natural-looking terrazzo pattern. The resin flakes 6 are obtained by forming a sheet of the aforementioned thickness from a resin material such as a polyvinyl chloride resin using calendering or the like, and then randomly crushing the sheet. In this way, multiple irregularly shaped resin flakes 6 are obtained.

[0037] (Fiber reinforced layer) The fiber reinforcement layer 3 is provided to give dimensional stability to the resin flooring material 1. The fiber reinforcement layer 3 is provided as needed. In Figures 4 and 5, the fiber reinforcement layer 3 is shown as a single layer structure, but it may also consist of two or more fiber reinforcement layers stacked on top of each other (not shown). The fiber reinforcement layer 3 can be, for example, a nonwoven fabric or a woven fabric. The material of the fibers constituting the nonwoven or woven fabric is not particularly limited and can be, for example, synthetic resin fibers such as polyester or polyolefin; inorganic fibers such as glass or carbon; or natural fibers. In particular, it is preferable to use a glass nonwoven fabric or glass woven fabric containing glass fibers as the fiber reinforcement layer 3 because it exhibits small dimensional changes due to temperature.

[0038] (Back layer) The back layer 4 is provided on the back side of the main body layer 2. The back layer 4 is provided as needed. The thickness of the back layer 4 is not particularly limited, but is, for example, 1 mm to 5 mm, and preferably 1.2 mm to 3 mm. The back layer 4 may or may not be foamed. For example, if the back layer 4 has a laminated structure of two or more layers, all of the layers may be foamed or not foamed, or at least one layer may be foamed and the remaining layers may not be foamed.

[0039] The back layer 4 is usually composed of a resin layer. As the synthetic resin that makes up the back layer 4, for example, a thermoplastic resin is used, and preferably a resin mainly composed of vinyl chloride resin is used. When the back layer 4 has a multilayer structure, each layer may be made of the same main resin, or each layer may be made of different main resins. For example, when the back layer 4 has a multilayer structure, it is preferable that all layers are made of resin with vinyl chloride resin as the main resin. In this case, each resin layer with vinyl chloride resin as the main resin may have the same composition or different compositions. Different compositions mean that the type of vinyl chloride resin, components other than vinyl chloride resin, the content of vinyl chloride resin, and / or the content of components other than vinyl chloride resin are different.

[0040] (protective layer) The protective layer 21 is the outermost layer of the flooring material. The protective layer 21 is provided to prevent scratches and dirt from adhering to the floor. The protective layer 21 is provided as needed. The protective layer 21 is composed of any suitable resin layer. A relatively strong protective layer 21 can be formed, and it is preferable that the protective layer 21 is made of a material containing an ionizing radiation-curable resin. The ionizing radiation-curable resin used is a resin that crosslinks and hardens when irradiated with charged particle beams or electromagnetic waves that have energy quanta capable of crosslinking monomers, etc. (e.g., electron beams, ultraviolet rays, etc.). As the ionizing radiation-curable resin, for example, a resin in which a curable monomer or oligomer has been hardened by ionizing radiation can be suitably used. Among ionizing radiation-curable resins, the protective layer 21 is more preferably formed from a material containing an ultraviolet-curable resin, as it is versatile. The ultraviolet-curable resin is not particularly limited, and for example, unsaturated polyesters such as condensates of unsaturated dicarboxylic acids and polyhydric alcohols, polyester (meth)acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, epoxy (meth)acrylate, melamine (meth)acrylate, and other (meth)acrylates can be used.

[0041] <Manufacturing method for resin flooring> The above-mentioned resin flooring material 1 can be manufactured, for example, by the following method. The method for manufacturing resin flooring includes the steps of: preparing vinyl chloride resin particles with a particle size of 20 μm to 300 μm (particle preparation step); preparing resin flakes (flake preparation step); forming multiple vinyl chloride resin particles and resin flakes in layers on a substrate to create a layered material in which the resin flakes are dispersed among the multiple vinyl chloride resin particles (layered material production step); and producing a sheet by heating the layered material (sheet production step). The particle size during manufacturing is the volume-average particle size (50% diameter), as described later. The layered material production step includes scattering the vinyl chloride resin particles and resin flakes onto a substrate. The vinyl chloride resin particles and resin flakes may be scattered simultaneously, sequentially, simultaneously, one or the other, or both sequentially. In the first embodiment, the layered material production step includes pre-mixing a plurality of vinyl chloride resin particles and resin flakes, and then scattering the mixture onto a substrate to ultimately form a layered material containing both. In the second embodiment, the layered material production step includes separately scattering vinyl chloride resin particles and resin flakes onto a substrate to ultimately form a layered material containing both. Preferably, the layered material production step of the first embodiment includes, in this order, a step of scattering resin flakes onto a substrate, and a step of scattering vinyl chloride resin particles with a particle size of 20 μm to 300 μm on top of the resin flakes, and more preferably, after scattering the vinyl chloride resin particles, a step of further scattering resin flakes on top of them onto the substrate. In the third embodiment, a plurality of vinyl chloride resin particles and resin flakes are mixed in advance, the mixture is sprayed onto a substrate, and then the vinyl chloride resin particles and resin flakes are sprayed separately on top of it, ultimately forming a layered material containing both. In the fourth embodiment, vinyl chloride resin particles and resin flakes are scattered separately onto a substrate, and then a mixture of vinyl chloride resin particles and resin flakes is scattered on top of that, ultimately forming a layered material containing both.

[0042] In the description of the manufacturing method, for the purpose of distinguishing between the vinyl chloride resin particles 7 formed as the resin flooring material 1 and the vinyl chloride resin particles used as raw materials before forming the resin flooring material 1, the vinyl chloride resin particles used as raw materials will be referred to as "raw material resin particles A". Furthermore, as mentioned above, the vinyl chloride resin particles 7 may have filler fine particles scattered on their surface, or they may not have filler fine particles attached to them. Here, we will explain the case in which vinyl chloride resin particles with filler fine particles attached are used. Hereafter, filler fine particles used as raw materials will be referred to as "raw material filler fine particles B", and particles to which raw material filler fine particles B are attached will be referred to as "raw material particles C".

[0043] (Particle preparation process) The vinyl chloride resin constituting the raw material resin particles A can be manufactured by emulsion polymerization, suspension polymerization, solution polymerization, or bulk polymerization. Vinyl chloride resins obtained by emulsion polymerization or suspension polymerization are preferred because they are easily formed into particles, and vinyl chloride resins obtained by suspension polymerization are particularly preferred. For example, particles made of vinyl chloride resin obtained by the suspension polymerization method are sieved using a screen to extract raw resin particles A of a desired particle size. The preferred volume-average particle size (50% diameter) of raw resin particles A is 20 μm to 300 μm, preferably 30 μm to 250 μm, and more preferably 50 μm to 200 μm. The volume-average particle size of the raw resin particles A can be measured using a laser diffraction scattering particle size distribution analyzer.

[0044] The average degree of polymerization of the vinyl chloride resin constituting the raw material resin particles A is not particularly limited, but is, for example, 650 to 1000, preferably 700 to 900. The average degree of polymerization can be measured by the solution viscosity measurement method using an Ubbelohde viscometer according to JIS K 6721. The K value of the vinyl chloride resin is not particularly limited, but is, for example, 58 to 70, preferably 60 to 65. The K value can be measured according to JIS K 7367-2. The apparent density of the vinyl chloride resin is not particularly limited, but is, for example, 0.45 to 0.75, preferably 0.5 to 0.7. The apparent density can be measured according to JIS K 7365.

[0045] Furthermore, as shown in Figure 13, raw material particles C consist of raw material resin particles A with smaller raw material filler fine particles B scattered on their surface. In Figure 13, areas where multiple raw material filler fine particles B are attached are shown with shading, while the solid areas in Figure 13 represent areas where the surface of the raw material resin particles A is exposed.

[0046] The raw material filler fine particles B can be any inorganic filler that is solid under standard conditions (standard conditions are 25°C and 1 atm), and any inorganic filler as described above can be used. Since it is inexpensive, it is preferable to use calcium carbonate fine particles for the raw material filler fine particles B. The volume-average particle size (50% diameter) of the raw material filler fine particles B is, for example, 0.05 μm to 20 μm, preferably 1 μm to 10 μm, and more preferably 2 μm to 6 μm. The volume-average particle size of the raw material filler fine particles B can be measured using a laser diffraction scattering particle size distribution analyzer. Note that the volume-average particle size of the raw material filler fine particles B represents the volume average value of the equivalent spherical diameter. While conventionally known pigments and dyes can be used as colorants, pigments are preferred because they are less prone to fading. Furthermore, the colorant may be in liquid or powder form, but a liquid colorant is preferred because it mixes more easily with the raw material resin particles A.

[0047] Raw material particles C can be obtained by mixing the above-mentioned raw material resin particles A, raw material filler fine particles B, plasticizer, and, if necessary, colorants and additives. The amount of raw material filler fine particles B is not particularly limited, but if it is too much, there is a risk that the raw material filler fine particles B will adhere to almost the entire surface of the raw material resin particles A, and if it is too little, the surface of the raw material resin particles A will be too exposed. From this viewpoint, the amount of raw material filler fine particles B is 1 to 100 parts by weight, preferably 1 to 50 parts by weight, per 100 parts by weight of raw material resin particles A. The amount of plasticizer is not particularly limited, for example, 20 to 50 parts by weight, preferably 30 to 40 parts by weight, per 100 parts by weight of raw material resin particles A. The amount of colorant can be appropriately set according to the type of colorant, for example, 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of raw material resin particles A.

[0048] When mixing the raw material resin particles A, raw material filler fine particles B, plasticizer, and optionally colorants and additives, the mixing should be carried out at a temperature sufficiently higher than room temperature (25°C) but below the temperature at which the vinyl chloride resin does not melt. For example, the mixing is preferably carried out in the temperature range of 80°C to 140°C, more preferably 100°C to 130°C, and even more preferably 110°C to 125°C. Furthermore, the mixing is preferably carried out at atmospheric pressure (especially without applying external pressure). By mixing within the aforementioned temperature range, the raw material resin particles A become slightly softer while maintaining a generally spherical shape without melting, and the raw material filler fine particles B come into contact with the surface of the raw material resin particles A. In this way, raw material particles C can be obtained in which raw material filler fine particles B, smaller than the raw material resin particles A, are scattered on the surface of the resin particles A, as shown in Figure 13.

[0049] Furthermore, by mixing raw material resin particles A, a plasticizer, and, if necessary, colorants and additives, without incorporating raw material filler fine particles B, raw material particles without filler fine particles adhering to their surface can be obtained. As described above, the aggregated portion 5 of the main body layer 2 may be composed of multiple vinyl chloride resin particles 7 without scattered filler fine particles, and such aggregated portion 5 is made using raw material particles without filler fine particles adhering to their surface.

[0050] (Thin section preparation process) Resin flakes are obtained by randomly crushing a resin sheet. For example, a resin material such as polyvinyl chloride resin can be formed into a sheet of the aforementioned thickness by calendering or other methods, and then the sheet can be randomly crushed to obtain pulverized material. As a crusher, for example, a screen-type granulator (manufactured by Kurimoto Iron Works Co., Ltd.) can be used. By using a screen-type crusher, pulverized material below a certain size can be obtained, making it easier to obtain resin flakes of a certain size range and to form the desired terrazzo pattern. However, even when using a screen-type crusher, fine pulverized material may be mixed in, so the pulverized material may contain a mixture of various sizes and shapes. In that case, the pulverized material can be passed through a sieve with relatively small mesh to remove the fine powder, thereby obtaining pulverized material of a certain size. This pulverized material from which the fine powder has been removed is used as resin flakes. If necessary, the resin flakes to be used may be further sieved. Specifically, when a resin sheet such as a polyvinyl chloride resin is randomly crushed, it is broadly classified into relatively large flakes, relatively small flakes, and fine powder that cannot be called flakes. The relatively large and relatively small flakes can be used as resin flakes as appropriate, but it is desirable to remove the fine powder as it does not contribute to the terrazzo pattern. Therefore, it is sieved to a degree that can remove the fine powder that cannot be called flakes. Through such sieving, resin flakes 6 within the above size range are obtained, but it is acceptable for some fine powder to be included. The reason for this is that completely removing the fine powder increases the number of work steps, while even if fine powder is included, it dissolves into the aggregated parts 5 in appearance and does not adversely affect the terrazzo pattern. The pulverized material (resin flakes) from which fine powder has been removed may be further sieved to group the resin flakes into multiple groups according to their size, such as relatively large resin flakes and relatively small resin flakes. Using grouped resin flakes makes it easier to form a terrazzo pattern that closely resembles the designed pattern.

[0051] (Layered material fabrication process according to the first embodiment) The layered material manufacturing process involves forming layers of raw material particles C containing vinyl chloride resin particles with a particle size of 20 μm to 300 μm and a material to be heated containing resin flakes 6 on a substrate. Figure 14 is a schematic diagram showing a manufacturing apparatus 9 for resin flooring material 1. In particular, Figure 14 shows a manufacturing apparatus 9 that performs the layered material manufacturing process according to the first embodiment.

[0052] In Figure 14, the manufacturing apparatus 9 includes a base material 91 that serves as the base for forming a layered material when manufacturing resin flooring material, a conveying section 92 for conveying the base material 91, a supply section 931 for supplying raw material particles C and resin flakes 6, a heating section 941 for heating the layered material, and a winding section 95 for winding up the manufactured sheet. A leveling section 961 for leveling the layered material is also provided downstream of the supply section 931. In the illustrated example, an embossing roll 97 for embossing is also provided, but if embossing is not performed, the embossing roll 97 and the heating section 943 (third heating section 943) immediately before the embossing roll 97 are omitted. By pressing with the embossing roll, the protrusion of resin flakes 6 present in the upper layer 2A (generation of steps 615) can be suppressed.

[0053] Specifically, the base material 91 is made from a sheet material on which raw material particles C can be placed and which can ultimately release the formed sheet (resin floor material 1). The base material 91 is provided in an annular shape on a conveying section 92 having a drive roll, for example. The base material 91 is a so-called endless belt. The white arrow indicates the conveying direction of the base material 91. In the first embodiment, one supply unit 931 is provided. When there is only one supply unit 931, as in this embodiment, the structure of the manufacturing apparatus 9 becomes relatively simple, and resin flooring material can be manufactured easily. The supply unit 931 includes a hopper 93a and a supply roll 93b. The outlet of the hopper 93a extends in the width direction of the substrate 91. The supply roll 93b rotates to feed the contents of the hopper 93a out through the outlet. The supply roll 93b consists of a pair of rolls, one of which is a smooth roll with a smooth surface on its circumferential surface, and the other is a textured roll with irregularities on its circumferential surface, as shown in the illustrated example. However, the pair of rolls is not limited to this, and either both may be smooth rolls, or either both may be textured rolls. In this embodiment, the supply unit 931 supplies the resin flakes 6 and raw material particles C onto the substrate 91 while mixing them. Although not specifically shown, there may be another supply unit for supplying the resin flakes 6 and another supply unit for supplying the raw material particles C. The heating element may be located in only one place, but in this embodiment, multiple heating elements are provided. In the illustrated example, three heating elements 941, 942, and 943 (first heating element 941, second heating element 942, and third heating element 943) are provided. The leveling section may be located in only one place, but in this embodiment, multiple leveling sections are provided. In the illustrated example, three leveling sections 961, 962, and 963 (first leveling section 961, second leveling section 962, and third leveling section 963) are provided. The first leveling section 961 is provided between the supply section 931, which is the most downstream supply section, and the first heating section 941. The second leveling section 962 is provided between the first heating section 941 and the second heating section 942. The third leveling section 963 is provided between the second heating section 942 and the third heating section 943.

[0054] The conveying unit 92 conveys the base material 91 at a predetermined speed, for example, 3 m / min to 15 m / min, and the supply unit 931 scatters a mixture of raw material particles C and resin flakes 6 onto the base material 91. In Figure 14, for convenience, the resin flakes 6 are represented by white circles and the raw material particles C are represented by black circles (the same applies to Figures 15 to 17). Immediately after being placed on the base material 91, some of the resin flakes 6 have surfaces that are approximately parallel to the surface of the base material 91, some have surfaces that are inclined relative to the surface of the base material 91, and some have surfaces that are approximately perpendicular to the surface of the base material 91. As the base material 91 is conveyed, vibrations and wind hit the resin flakes 6, so these resin flakes 6 become approximately parallel to the surface of the base material 91 while being conveyed. In this way, a layered material 11 made up of accumulated raw material particles C and resin flakes 6 is formed on the base material 91. In this embodiment, since the pre-mixed raw material particles C and resin flakes 6 are scattered onto the base material 91, a resin flooring material 1 containing resin flakes 6 in the upper layer 2A and lower layer 2B can be manufactured. The total amount of raw material particles C and resin flakes 6 that make up the layered material 11 can be designed as appropriate, but for example, the weight ratio of raw material particles C:resin flakes 6 is 95:5 to 60:40, and preferably 90:10 to 75:25. This ratio allows a natural terrazzo pattern to appear while also ensuring sufficient strength as a flooring material.

[0055] To level the thickness of the layered material 11 to some extent, the layered material 11 is passed through the first leveling section 961. The first leveling section 961 consists of, for example, a pair of rolls with a predetermined gap between them, and the layered material 11 is leveled by passing it between these rolls.

[0056] This layered material 11 is heated in a first heating unit 941 such as an oven to melt the vinyl chloride resin of the raw material particles C. The heating temperature should be above the temperature at which the vinyl chloride resin melts, for example, 170°C to 220°C. The first heating unit 941 should be set to maintain the above temperature range. After heating in the first heating section 941, the material is further leveled under pressure in the second leveling section 962, then heated again in the second heating section 942, and then leveled under pressure in the third leveling section 963. A pair of pressure rolls can be used as the second leveling section 962 and the third leveling section 963. By applying pressure and leveling before and / or after heating, a sheet 12 (resin flooring material 1) can be obtained in which the thickness distribution in the width direction is substantially uniform and there is substantially no step at the boundary between the resin flakes 6 and the aggregated parts 5 on the surface. In particular, by performing the step of applying pressure and leveling at least once between two heating parts, preferably by having three or more heating parts and performing the step of applying pressure and leveling at least once between each heating part, a sheet 12 with a more uniform thickness distribution and substantially no step can be obtained. A resin flooring material 1 with a substantially uniform thickness distribution in the width direction and excellent surface smoothness is less prone to rippling and bulging wrinkles when rolled up. Therefore, a resin flooring material 1 with high smoothness can be obtained. The aforementioned rippling and bulging wrinkles are a phenomenon generally called "flare," and although they can sometimes be observed when the sheet material is rolled up, they are often visible in oblique light when unrolled and spread out on a flat surface.

[0057] When embossing the sheet 12, the sheet 12 is heated in the third heating section 943 and then passed through the embossing roll 97 to form embossed irregularities on the surface of the sheet. The resulting sheet 12 (resin flooring material 1) is wound onto a winding unit. Alternatively, before being wound onto the winding unit, further processing, such as the formation of a protective layer 21, may be performed.

[0058] (Layered material fabrication process according to the second embodiment) Next, a second embodiment of the layered material manufacturing process will be described. However, in this description, the configuration will mainly be described in a manner different from the first embodiment described above, and for similar configurations, the same terms or symbols will be used, and the explanation of such configurations may be omitted (the same applies to the third embodiment and subsequent embodiments). In the layered material creation process of the second embodiment, raw material particles C and resin flakes 6 are scattered separately onto the substrate 91. The scattering of raw material particles C and resin flakes 6 may be done once each, or one may be done multiple times and the other once, or both may be done multiple times each. In this embodiment, since the raw material particles C and resin flakes 6 are scattered separately, the amount of each scattered can be controlled individually, allowing for more precise expression of colors, patterns, and other characteristics. The apparatus 9 for performing this process includes one or more supply units for supplying raw material particles C to a substrate, and one or more supply units for supplying resin particles 6 to the substrate. If there are multiple supply units for either or both of the raw material particle C and resin particle 6, the supply units for the raw material C and the supply units for the resin particles 6 may be arranged alternately from upstream to downstream, or some or all of the supply units supplying the same material may be arranged side by side.

[0059] Figure 15 shows a manufacturing apparatus 9 that performs a layered material manufacturing process according to the first example of the second embodiment. In Figure 15, the first example of the manufacturing apparatus 9 in the second embodiment has two supply units 932 and 933 instead of the supply unit 931 of the first embodiment. That is, two supply units 932 and 933 are provided upstream of the first leveling unit 961, with one supply unit supplying raw material particles C onto the substrate 91 and the other supply unit supplying resin flakes 6 onto the substrate 91. Hereafter, prefixes indicating the order of the multiple supply units arranged from upstream to downstream will be added, such as "first supply unit," "second supply unit," and so on, starting from the upstream side. The manufacturing apparatus 9 of the first embodiment is the same in all other respects.

[0060] Specifically, the first supply unit 932 and the second supply unit 933 have a hopper 93a and a supply roll 93b, similar to the supply unit 931 of the first embodiment. The hopper 93a of the first supply unit 932 contains resin flakes 6. The resin flakes 6 are fed out from the outlet by the rotation of the supply roll 93b and supplied by being scattered onto the substrate 91. The hopper 93a of the second supply unit 933 contains raw material particles C. The raw material particles C are fed out from the outlet by the rotation of the supply roll 93b and supplied by being scattered onto the substrate 91.

[0061] In the manufacturing apparatus 9 of the second embodiment, similar to the first embodiment, the conveying unit 92 conveys the base material 91 at a predetermined speed. The resin flakes 6 are scattered onto the conveyed base material 91 from the first supply unit 932. Immediately after being placed on the base material 91, some of the multiple resin flakes 6 have surfaces that are approximately parallel to the surface of the base material 91, some have surfaces that are inclined relative to the surface of the base material 91, and some have surfaces that are approximately perpendicular to the surface of the base material 91. As the base material 91 is conveyed, vibrations and wind hit the resin flakes 6, so as they are conveyed, their surfaces become approximately parallel to the surface of the base material 91. Therefore, downstream of the first supply unit 932, multiple resin flakes 6 are arranged randomly on the base material 91. By adjusting the amount of resin flakes 6 scattered per unit time, the resin flakes 6 can be arranged on the base material 91 with less overlap.

[0062] Next, raw material particles C are scattered onto the resin flakes 6 from the second supply unit 933. Because the raw material particles C are fine, they accumulate on the resin flakes 6 and on the substrate 91 between the resin flakes 6. In this way, a layered material 11 is formed on the substrate 91. The resulting layered material 11 is leveled by the first leveling unit 961. Due to vibrations applied to the layered material 11 as the base material 91 is transported, and external forces are applied to the layered material 11 by the first leveling unit 961, fine raw material particles C tend to move towards the base material 91. As a result, the raw material particles C tend to wrap around to the bottom of the resin flakes 6 supplied onto the base material 91 by the first supply unit 932, and as shown in Figure 15, the layered material 11 downstream of the first leveling unit 961 has a state in which the resin flakes 6 are dispersed in the layer of raw material particles C in the thickness direction. The more raw material particles C wrap around, the greater the amount of resin flakes 6 located on the upper side, and a resin floor material 1 is obtained that contains more resin flakes 6 in the upper layer 2A than in the lower layer 2B. The amount of raw material particles C that wrap around the material varies depending on the vibration time applied to the layered material 11, the degree of leveling by the first leveling section 961, and the transport speed of the base material 91. By appropriately designing these factors, the amount of resin flakes 6 contained in the upper layer 2A and the lower layer 2B can be adjusted. Subsequently, similar to the first embodiment, the sheet 12 (resin flooring material 1) is obtained by heating and pressurizing the layered material 11.

[0063] Figure 16 shows a manufacturing apparatus 9 that performs a layered material manufacturing process according to a second example of the second embodiment. The manufacturing apparatus 9 shown in Figure 16 has three supply units 932, 933, and 934. That is, the three supply units 932, 933, and 934 are arranged in order upstream of the first leveling unit 961, with one or two of the supply units supplying raw material particles C onto the substrate 91, and the remaining supply units supplying resin flakes 6 onto the substrate 91. In other respects, the manufacturing apparatus 9 of the first embodiment is the same. As in this embodiment, increasing the number of supply units can increase the degree of freedom in forming layered materials.

[0064] Specifically, the first supply unit 932, the second supply unit 933, and the third supply unit 934 each have a hopper 93a and a supply roll 93b, similar to the supply unit 931 of the first embodiment. The hopper 93a of the first supply unit 932 and the third supply unit 934 contains resin flakes 6. The resin flakes 6 are fed out from the outlet by the rotation of the supply roll 93b and supplied by being scattered onto the substrate 91. The hopper 93a of the second supply unit 933 contains raw material particles C. The raw material particles C are fed out from the outlet by the rotation of the supply roll 93b and supplied by being scattered onto the substrate 91.

[0065] A layered material 11 is formed on the substrate 91 by scattering resin flakes 6 from the first supply unit 932, then scattering raw material particles C from the second supply unit 933 on top of that, and then scattering resin flakes 6 from the third supply unit 934 on top of that. In this case as well, as explained in the first example of the second embodiment, the resin flakes 6 scattered from the first supply unit 932 and the third supply unit 934 become approximately parallel to the surface of the substrate 91 as the substrate 91 is transported. In addition, as the substrate 91 is transported, the raw material particles C can easily move around to the underside of the resin flakes 6. As described above, when the resin is grouped into multiple resin flakes according to size, for example, relatively small resin flakes 6 may be scattered onto the substrate 91 by the first supply unit 932, or relatively large resin flakes 6 may be scattered onto the substrate 91 by the first supply unit 932. In one example, relatively small resin flakes 6 are supplied by the first supply unit 932, and relatively large resin flakes 6 are supplied by the third supply unit 934. In another example, relatively small resin flakes 6 or relatively large resin flakes 6 are supplied by the first supply unit 932, and the relatively large resin flakes 6 and relatively small resin flakes 62 are mixed and supplied by the third supply unit 934. In this way, a layered material 11, in which raw material particles C and resin flakes 6 are deposited in layers, is formed on the substrate 91.

[0066] Figure 17 shows a manufacturing apparatus 9 that performs a layered material production process according to a third example of the second embodiment. The manufacturing apparatus 9 shown in Figure 17 has four supply units 932, 933, 934, and 935. That is, the four supply units 932, 933, 934, and 935 are arranged in order upstream of the first leveling unit 961, with one or more of the supply units supplying raw material particles C onto the substrate 91, and the remaining supply units supplying resin flakes 6 onto the substrate 91. In other respects, the manufacturing apparatus 9 of the first embodiment is the same.

[0067] Specifically, the first supply unit 932, the second supply unit 933, the third supply unit 934, and the fourth supply unit 935 each have a hopper 93a and a supply roll 93b, similar to the supply unit 931 of the first embodiment. The hopper 93a of the first supply unit 932 and the third supply unit 934 contains resin flakes 6. The resin flakes 6 are fed out from the outlet by the rotation of the supply roll 93b and supplied by being scattered onto the substrate 91. The hopper 93a of the second supply unit 933 and the fourth supply unit 935 contains raw material particles C. The raw material particles C are fed out from the outlet by the rotation of the supply roll 93b and supplied by being scattered onto the substrate 91. After the resin flakes 6 are scattered from the first supply unit 932, raw material particles C are scattered on top of them from the second supply unit 933, then the resin flakes 6 are scattered on top of them from the third supply unit 934, and then raw material particles C are scattered on top of them from the fourth supply unit 935, thereby forming a layered material 11 on the substrate 91.

[0068] Although not specifically shown in the diagram, there may be five or more supply units in total, which supply the raw material particles C and the resin flakes 6. In this embodiment, as the base material 91 is transported, the raw material particles C tend to move downward, resulting in a resin flooring material 1 in which the resin flakes 6 are biased towards the upper layer 2A. Therefore, this embodiment has the advantage that the amount of resin flakes 6 contained in the upper layer 2A and the lower layer 2B can be adjusted relatively easily.

[0069] (Layered material fabrication process according to the third embodiment) The third embodiment is a layered material manufacturing process that combines the first and second embodiments. The layered material manufacturing process of the third embodiment, although not specifically shown, involves scattering a mixture of raw material particles C and resin flakes 6 onto a substrate 91, and then scattering only raw material particles C on top of that; or scattering a mixture of raw material particles C and resin flakes 6 onto a substrate 91, and then scattering only resin flakes 6 on top of that; or scattering a mixture of raw material particles C and resin flakes 6 onto a substrate 91, and then scattering only raw material particles C on top of that, and then scattering only resin flakes 6; or scattering a mixture of raw material particles C and resin flakes 6 onto a substrate 91, and then scattering only resin flakes 6 on top of that, and then scattering only raw material particles C. According to this layered material manufacturing process, the amount of resin flakes 6 contained in the upper layer 2A and the lower layer 2B can be adjusted relatively easily.

[0070] (Layered material fabrication process according to the fourth embodiment) The fourth embodiment is also a layered material manufacturing process that combines the first and second embodiments. The layered material manufacturing process of the fourth embodiment, although not specifically shown, involves scattering only resin flakes 6 onto the substrate 91, then scattering only raw material particles C, and then scattering a mixture of raw material particles C and resin flakes 6 onto the substrate 91; or scattering only resin flakes 6 onto the substrate 91, and then scattering a mixture of raw material particles C and resin flakes 6 onto the substrate 91; or scattering only raw material particles C onto the substrate 91, and then scattering a mixture of raw material particles C and resin flakes 6 onto the substrate 91. [Explanation of symbols]

[0071] 1. Resin flooring 2. Main Layer 2A upper layer 2B Lower layer 5 Agglomeration part 6 Resin flakes 7. Vinyl chloride resin particles

Claims

1. The main body layer comprises an aggregated portion in which multiple vinyl chloride resin particles with a particle size of 20 μm to 300 μm are aggregated, and multiple resin flakes fixed to the aggregated portion. A resin flooring material in which, when the main body layer is divided into an upper layer including the surface of the main body layer and a lower layer including the back surface of the main body layer, the resin flakes are contained in the upper layer and the lower layer of the main body layer, respectively.

2. The resin flooring material according to claim 1, wherein the upper layer of the main body layer includes a resin flake having a portion exposed on the surface of the main body layer.

3. The resin flooring material according to claim 1, comprising resin flakes parallel to the surface of the main body layer or inclined at an angle of 30 degrees or less with respect to the surface of the main body layer.

4. A layered material manufacturing process, in which a material to be heated, containing multiple vinyl chloride resin particles and resin flakes with a particle size of 20 μm to 300 μm, is formed in layers on a substrate, thereby producing a layered material. The process includes a sheet manufacturing step of producing a sheet by heating the layered material to be heated, A method for manufacturing a resin flooring material, wherein the layered material production step includes scattering the vinyl chloride resin particles and resin flakes.

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