JP2016211145A - Flooring material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flooring material excellent in strength.SOLUTION: A rubber flooring sheet 1 includes a base rubber 2, and a rubber chip 3 added to the base rubber 2. At least one of the base rubber 2 and the rubber chip 3 includes fine cellulose fiber 4.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a flooring.

  It is known to apply rubber compositions containing so-called cellulose fibers to flooring.

  For example, Patent Document 1 discloses that a rubber composition containing cellulose microfibrils having an average diameter of less than 0.8 μm is applied to a flooring.

JP-T-2002-503621

  An object of the present invention is to provide a flooring having excellent strength.

  The floor material according to the present invention is a floor material having a sheet-like rubber material and a chip-like rubber material added to the sheet-like rubber material, and at least of the sheet-like rubber material and the chip-like rubber material One is characterized by containing cellulosic fine fibers.

  According to the present invention, the sheet-like rubber material and / or the chip-like rubber material contains cellulosic fine fibers, whereby the strength of the sheet-like rubber material and / or the chip-like rubber material can be improved. The strength of the provided flooring can be effectively improved.

It is the (a) sectional view showing the rubber floor sheet concerning Embodiment 1 typically, and (b) the expanded sectional view.

  Hereinafter, embodiments will be described in detail.

[Embodiment 1]
(Rubber floor sheet)
A rubber floor sheet (floor material) 1 according to Embodiment 1 includes a sheet-shaped base rubber (sheet rubber material) 2 and chip rubber (chip rubber material) 3 added to the base rubber 2. The chip rubber 3 contains cellulosic fine fibers 4.

  The tensile strength of the rubber floor sheet 1 is a measured value based on JIS K 6251, preferably 3 MPa or more, and preferably 100 MPa or less.

  The slip resistance coefficient D of the rubber floor sheet 1 is a measured value based on JIS A 1407, and is preferably 0.3 or more, more preferably 0.5 or more when dry, and preferably when wet. It is 0.2 or more, more preferably 0.3 or more.

<Base rubber>
The base rubber 2 is a main component of the rubber floor sheet 1 and defines the sheet shape. The base rubber 2 includes a rubber component made of a crosslinkable rubber, a thermoplastic rubbery polymer, or a mixture thereof.

  Crosslinkable rubbers include sulfur such as SBR (styrene / butadiene rubber), NR (natural rubber), BR (butadiene rubber), NBR (nitrile / butadiene rubber), CR (chloroprene rubber), EPR (ethylene / propylene rubber), etc. In addition, a material in which a three-dimensional network chain is formed by a crosslinking agent such as a metal oxide, a peroxide, or a resin is applied. These may be used alone or in combination.

  As thermoplastic rubbery polymers, SBS type teleblocks with styrene (S) and butadiene (B), multi-block copolymers, high styrene rubber, 1,2-polybutadiene and so-called thermoplastic elastomers are applied. Is done. These may be used alone or in a mixture of a plurality of types.

  As a compounding agent mix | blended with the base rubber 2, a filler, a function imparting agent, an anti-aging agent, a vulcanization accelerator, a processing aid, a crosslinking agent, etc. are mentioned.

  Examples of the filler include clay, calcium carbonate, talc, diatomaceous earth, and the like. The filler may be composed of a single species or a plurality of species.

  The function-imparting agent, for example, imparts tackiness or the like to the rubber composition, and specifically includes petroleum resin, coumarone resin, and the like. The function-imparting agent may be composed of a single species or a plurality of species.

  Examples of the anti-aging agent include a phenol-based anti-aging agent and an amine-based anti-aging agent. The anti-aging agent may be composed of a single species or a plurality of species.

  Examples of the vulcanization accelerator include sulfenamide (eg, CZ), thiazole (eg, MBT, MBTS, etc.), thiuram (eg, TT, TRA, etc.), dithiocarbamate (eg, BZ-P). And the like. The vulcanization accelerator may be composed of a single species or a plurality of species. Content of a vulcanization accelerator is 1-5 mass parts with respect to 100 mass parts of rubber components of a rubber composition, for example.

  Examples of the processing aid include stearic acid, polyethylene wax, and metal salts of fatty acids. The processing aid may be composed of a single species or a plurality of species. The content of the processing aid is, for example, 0.5 to 2 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition.

  Crosslinking agents include sulfur and organic peroxides. As a crosslinking agent, sulfur may be blended, an organic peroxide may be blended, or both of them may be used in combination. In the case of sulfur, the compounding amount of the crosslinking agent is, for example, 1 to 7 parts by mass with respect to 100 parts by mass of the rubber component of the rubber composition. For example, 1 to 7 parts by mass.

  The thermal expansion coefficient of the base rubber 2 is preferably a change rate of the thermal expansion coefficient at 200 ° C. and normal temperature based on JIS K 7197, preferably 10 ppm / K or less, more preferably 5 ppm / K or less, and still more preferably 3 ppm / K or less.

<Chip rubber>
The chip rubber 3 imparts design properties to the rubber floor sheet 1 by being added to the base rubber 2.

  The chip rubber 3 may be added to the entire base rubber 2 or may be embedded only near the surface of the base rubber 2 as shown in FIG. More preferably, it is effective that the rubber floor sheet 1 is embedded only in the vicinity of the surface of the base rubber 2 from the viewpoint of improving the design of the rubber floor sheet 1 and reducing the amount of chip rubber 3 added. In particular, at least a part of the chip rubber 3 is preferably exposed on the surface of the rubber floor sheet 1. Thereby, the slip resistance coefficient of the rubber floor sheet 1 increases, and the slip resistance of the rubber floor sheet 1 can be effectively improved.

  Specifically, the chip rubber 3 is, for example, a pulverized product of a rubber molded body made of a rubber component having the same or different rubber component as that of the base rubber 2, and may be heat-treated or not heat-treated. A thing may be used.

  In the same manner as the base rubber 2, the above-mentioned various compounding agents can be added to the rubber component of the chip rubber 3.

  In the first embodiment, the chip rubber 3 contains cellulosic fine fibers 4.

  The cellulosic fine fiber 4 is a fiber material derived from a cellulosic fine fiber composed of a skeletal component of a plant cell wall obtained by finely loosening the plant fiber. Examples of the raw material plant for the cellulosic fine fibers 4 include wood, bamboo, rice (rice straw), potato, sugar cane (bagasse), aquatic plants, seaweed and the like. Of these, wood is preferred.

  The cellulosic fine fibers 4 may be either the cellulose fine fibers themselves or the hydrophobic cellulose fine fibers subjected to the hydrophobic treatment. Moreover, as the cellulose-based fine fiber 4, the cellulose fine fiber itself and the hydrophobic cellulose fine fiber may be used in combination. From the viewpoint of dispersibility, the cellulosic fine fibers 4 preferably include hydrophobic cellulose fine fibers. Examples of the hydrophobized cellulose fine fibers include cellulose fine fibers in which some or all of the hydroxyl groups of cellulose are substituted with hydrophobic groups, and cellulose fine fibers that have been subjected to a hydrophobized surface treatment with a surface treatment agent.

  Examples of the hydrophobization for obtaining cellulose fine fibers in which some or all of the hydroxyl groups of cellulose are substituted with hydrophobic groups include esterification (acylation) (alkyl esterification, complex esterification, β-ketoesterification, etc.) ), Alkylation, tosylation, epoxidation, arylation and the like. Of these, esterification is preferred. Specifically, in the esterified hydrophobized cellulose fine fiber, part or all of the hydroxyl groups of cellulose are carboxylic acids such as acetic acid, acetic anhydride, propionic acid, butyric acid, or halides thereof (particularly chlorides). It is the cellulose fine fiber acylated by. Examples of the surface treatment agent for obtaining cellulose fine fibers hydrophobized and surface-treated with the surface treatment agent include silane coupling agents.

  From the viewpoint of improving the strength of the rubber floor sheet 1, it is preferable that the cellulose fine fibers 4 have a wide fiber diameter distribution. From the viewpoint of improving the strength of the rubber floor sheet 1, the fiber diameter distribution range of the cellulosic fine fibers 4 preferably includes 3 to 500 nm.

  From the viewpoint of improving the strength of the rubber floor sheet 1, the average fiber diameter of the cellulosic fine fibers 4 contained in the chip rubber 3 is preferably 10 nm or more and 200 nm or less.

  The fiber diameter distribution of the cellulosic fine fibers 4 is obtained by freeze-grinding a sample of the chip rubber 3 and then observing the cross section with a transmission electron microscope (TEM) and arbitrarily selecting 50 cellulosic fine fibers. The fiber diameter is measured and obtained based on the measurement result. Moreover, the average fiber diameter of the cellulosic fine fiber 4 is calculated | required as the number average of the fiber diameter of the 50 cellulosic fine fibers 4 arbitrarily selected.

  The cellulosic fine fibers 4 may be either high aspect ratio manufactured by mechanical defibrating means or manufactured by chemical defibrating means. Moreover, as the cellulose fine fiber 4, you may use together what was manufactured by the mechanical defibrating means, and what was manufactured by the chemical defibrating means. Examples of the defibrating apparatus used for the mechanical defibrating means include a kneader such as a twin-screw kneader, a high-pressure homogenizer, a grinder, and a bead mill. Examples of the treatment used for the chemical defibrating means include acid hydrolysis treatment.

  In the chip rubber 3, the cellulosic fine fibers 4 are not oriented in a specific direction and are not oriented.

  The content of the cellulosic fine fibers 4 in the chip rubber 3 is preferably 1 part by mass or more, more preferably 3 parts by mass or more, more preferably 100 parts by mass with respect to 100 parts by mass of the rubber component, from the viewpoint of improving the strength of the rubber floor sheet 1. The amount is preferably 5 parts by mass or more, preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less.

  Further, the blending ratio of the base rubber 2 and the chip rubber 3 is such that the chip rubber 3 has 100 parts by mass of the rubber composition of the base rubber 2 with respect to 100 parts by mass of the rubber composition of the base rubber 2 from the viewpoint of improving the design property, strength, slip resistance, etc. The rubber composition is preferably 1 part by mass or more, and preferably 10 parts by mass or less.

  The shape of the chip rubber 3 may be various shapes such as a cubic shape, a rectangular parallelepiped shape, an uneven shape, a substantially spherical shape, and a substantially disc shape. The size of the chip rubber 3 is preferably 5 mm or more, more preferably 8 mm or more, and further preferably 10 mm or more, from the viewpoint of improving the design, strength, slip resistance, etc. of the rubber floor sheet 1. Preferably, it is 100 mm or less, More preferably, it is 80 mm or less, More preferably, it is 60 mm or less. Further, the minimum width is preferably 1 mm or more, more preferably 2 mm or more, further preferably 3 mm or more, preferably 10 mm or less, more preferably 7 mm or less, and further preferably 5 mm or less.

  The thermal expansion coefficient of the chip rubber 3 is preferably 90 or less, more preferably 80 or less, when the thermal expansion coefficient of the base rubber 2 is 100.

(Rubber floor sheet manufacturing method)
Hereinafter, the manufacturing method of the rubber floor sheet 1 according to the first embodiment will be described.

-Base rubber-
Various compounding agents are blended into the rubber component and kneaded with a kneader such as a kneader, Banbury mixer, or biaxial kneader, and the resulting composition is molded into a sheet shape by calendar molding or the like to produce a rubber sheet 2 ′. To do.

-Chip rubber-
In the first embodiment, the chip rubber 3 contains cellulosic fine fibers 4 and is manufactured by the following procedure.

  First, the cellulosic fine fibers 4 are put into the kneaded rubber component and dispersed by kneading.

  Here, as a method for dispersing the cellulose-based fine fibers in the rubber component, for example, a dispersion (gel) in which the cellulose-based fine fibers are dispersed in water is added to the rubber component kneaded with an open roll, A method of vaporizing moisture while kneading them, a master of cellulose fine fibers / rubber obtained by mixing a dispersion (gel) in which cellulosic fine fibers are dispersed in water and rubber latex to vaporize the moisture A method in which a batch is put into a kneaded rubber component, obtained by mixing a dispersion in which hydrophobic cellulose fine fibers are dispersed in a solvent and a solution in which the rubber component is dissolved in a solvent, and evaporating the solvent. Of the obtained cellulose-based fine fiber / rubber masterbatch into the kneaded rubber component, and the dispersion (gel) in which the cellulose-based fine fiber is dispersed in water is freeze-dried A material obtained by pulverizing, a method of introducing the rubber component is masticated, methods and the like to introduce cellulosic microfibers made hydrophobic in rubber component is masticated.

  In addition, you may add surfactant further to such a dispersion (gel) or a masterbatch. Thereby, the compatibility of the cellulosic fine fiber 4 and the rubber component is improved. Furthermore, the hydrophilic group of the surfactant improves the affinity with water and decreases the electrical resistance. Therefore, the antistatic function can be imparted to the chip rubber 3 and thus the rubber floor sheet 1.

  Next, while kneading the rubber component and the cellulosic fine fiber 4, various compounding agents are added and kneading is continued.

  Then, the obtained rubber composition is molded into a sheet shape by calendar molding or the like to produce a rubber sheet 3 ′ for the chip rubber 3.

  Finally, sulfur is added to the rubber sheet 3 ′ and then finely pulverized to obtain the chip rubber 3. Further, heat treatment is performed as necessary.

  Examples of the method for pulverizing the rubber sheet 3 'include methods such as cutting and mill crushing. The size of the chip rubber 3 can be measured by methods such as visual observation and optical microscope observation.

-Rubber floor sheet-
Examples of the method for adding the chip rubber 3 to the base rubber 2 include the following methods.

  That is, when the chip rubber 3 is added to the entire rubber floor sheet 1, there is a method of kneading the chip rubber 3 into the base rubber 2 in the process of manufacturing the base rubber 2. When the chip rubber 3 is added only near the surface of the rubber floor sheet 1, the chip rubber 3 is sprayed on the surface of the rubber sheet 2 ′ formed into a sheet shape, and is embedded in the base rubber 2 by heating and pressing. There is a way to do it.

  At this time, the chip rubber 3 is embedded on the surface of the rubber floor sheet 1 with a part thereof exposed. Further, the chip rubber 3 is compressed and deformed into a convex shape by contraction of the base rubber 2 after heating and pressurization.

  In this manner, the chip rubber 3 can be embedded in the vicinity of the surface of the rubber floor sheet 1 and a chip-shaped pattern can be attached to the surface of the rubber floor sheet 1.

  In addition, it can be set as the structure which affixes an adhesive layer in the single side | surface of the rubber floor sheet 1, and affixes the rubber floor sheet 1 on a desired floor surface through this adhesive layer. In this case, it is preferable that the chip rubber 3 is added so that a pattern is formed on the surface opposite to the surface on which the adhesive layer is formed in the rubber floor sheet 1.

  According to the rubber floor sheet 1 according to the first embodiment, when the chip rubber 3 contains the cellulosic fine fibers 4, excellent strength can be imparted to the rubber floor sheet.

  For example, it is common to add carbon black as a reinforcing material to a rubber product, but according to the rubber floor sheet 1 according to the first embodiment, the chip rubber 3 includes the cellulosic fine fibers 4, Since the strength of the rubber floor sheet 1 is improved, the above-described carbon black is not added to the base rubber 2 and / or the chip rubber 3. Further, by containing the cellulosic fine fibers 4, the rubber floor sheet 1 is imparted with excellent strength and, for example, the cellulosic fine fibers are dyed to give the rubber floor sheet 1 a desired color tone. And so on.

  In addition, since the intensity | strength of the rubber floor sheet 1 can be controlled by content of the cellulosic fine fiber 4 in the chip rubber 3, by adjusting the content, desired strength can be given to the rubber floor sheet 1. Can be granted.

  Moreover, the thermal expansion coefficient of the chip rubber 3 is reduced by containing the cellulosic fine fibers 4 in the chip rubber 3. The dimensional change after heating and pressurizing the base rubber 2 to which the chip rubber 3 is added is smaller in the chip rubber 3 than in the base rubber 2. The shape of the chip rubber 3 changes and becomes convex due to the shrinkage of the base rubber 2 having a large dimensional change. And, such a convex chip rubber 3 is embedded on the surface of the rubber floor sheet 1 so that a part thereof is exposed, so that the slip resistance coefficient increases, and the rubber floor sheet 1 is Improved slip resistance when laid on the floor.

  The difference in dimensional change between the base rubber 2 and the chip rubber 3 after heating and pressure molding is controlled by the addition amount of the cellulosic fine fibers 4 added to the chip rubber 3 in addition to the blending of the base rubber 2 and the chip rubber 3. Therefore, the slip resistance coefficient can be adjusted to effectively improve the slip resistance of the rubber floor sheet 1.

  Further, the chip rubber 3 is usually subjected to a heat treatment before being spread on the surface of the rubber sheet 2 'of the base rubber. This is to increase the viscosity difference from the base rubber by performing a heat treatment, and to prevent the chip rubber 3 from flowing and spreading into the base rubber 2 in the heating / pressurizing process of the rubber floor sheet 1. Done. In this regard, when the chip rubber 3 contains the cellulosic fine fibers 4, the change in the viscosity of the chip rubber 3 with respect to the temperature is reduced, so that the viscosity difference between the base rubber 2 and the chip rubber 3 at a high temperature can be increased. Thereby, the spreading of the chip rubber 3 into the base rubber 2 in the heating / pressurizing step can be effectively suppressed. Moreover, since the viscosity difference between the base rubber 2 and the chip rubber 3 can be easily increased by containing the cellulosic fine fibers 4 in the chip rubber 3, the heat treatment step of the chip rubber 3 can be simplified or completely omitted. it can.

[Embodiment 2]
In the rubber floor sheet 1 according to the first embodiment, the chip rubber 3 contains the cellulosic fine fibers 4, but the cellulosic fine fibers 4 are contained in the base rubber 2 or both the base rubber 2 and the chip rubber 3. A configuration may be adopted. Thereby, the intensity | strength of the rubber floor sheets 1 can be improved effectively. Moreover, by adjusting the content of the cellulosic fine fibers 4, the strength of the rubber floor sheet 1 can be controlled, and desired slip resistance and the like can be imparted to the rubber floor sheet 1.

  Tables 1 and 2 show the formulations of the base rubbers and the chip rubbers of Examples 1 to 5 and Comparative Example 1.

Example 1
<Base rubber>
As a rubber component of the base rubber, SBR rubber (product number: 1502, manufactured by JSR Corporation) was kneaded in MIXTRON BB180 manufactured by Kobe Steel. Thereto, 100 parts by weight of the rubber component, 150 parts by weight of clay (product number: Dixie clay, manufactured by RT VANDERBILT. Co. Ltd) and heavy calcium carbonate (product number: KS-500, Cal Co., Ltd.) Fine product (100 parts by mass) and 20 parts by mass of titanium oxide (product number: Titanium oxide A-100, manufactured by Ishihara Sangyo) as a white filler were added and further kneaded. Finally, as a function-imparting agent, petroleum resin (product number: T-REZ RA100, manufactured by TonenGeneral Sekiyu KK) 5 parts by mass, anti-aging agent (product number: NOCRACK SP / SUNNOCK, manufactured by Ouchi Shinko Chemical Co., Ltd.), And 1.5 parts by mass of a vulcanization accelerator (Part No .: Noxeller NS-P, TS-G, manufactured by Ouchi Shinko Chemical Co., Ltd.) and stearic acid (Part No .: beads, stearic acid Tsubaki, Sanyu Industrial Co., Ltd.) 2 parts by mass were added and kneaded with a Banbury mixer. The rubber after kneading is made into a sheet with TSR, and then 6 parts by mass of sulfur (product number: Seimi OT, manufactured by Rubber Industrial Materials Co., Ltd.) as a cross-linking agent is charged with a mill blender. )

<Cellulose dispersion gel>
A dispersion in which powdered cellulose (trade name: KC Flock W-50GK, manufactured by Nippon Paper Industries Co., Ltd.) is dispersed in water is prepared, and the dispersion is collided with a high-pressure homogenizer to dissolve the powdered cellulose into cellulose fine fibers. A gel in which cellulose fine fibers were dispersed in water (hereinafter referred to as “cellulose-dispersed gel”) was obtained. Accordingly, the cellulose fine fibers are produced by mechanical defibrating means and are not subjected to a hydrophobic treatment.

<Chip rubber>
As the chip rubber, SBR rubber (product number: 1502, manufactured by JSR Corporation) is kneaded with MIXTRON BB180 manufactured by Kobe Steel Co., Ltd., and the cellulose dispersion gel is added thereto so that the content of the cellulose fine fiber is 1 part by mass. After that, the mixture was further kneaded to evaporate water. As a filler, 125 parts by mass of clay (product number: dexterous clay, manufactured by RT VANDERBILT. Co. Ltd), 50 parts by mass of heavy calcium carbonate (product number: KS-500, manufactured by Calfine Co., Ltd.), white filling As an agent, 20 parts by mass of titanium oxide (product number: titanium oxide A-100, manufactured by Ishihara Sangyo) was added and further kneaded. Finally, as a function-imparting agent, petroleum resin (product number: T-REZ RA100, manufactured by TonenGeneral Sekiyu KK) 5 parts by mass, anti-aging agent (product number: NOCRACK SP / SUNNOCK, manufactured by Ouchi Shinko Chemical Co., Ltd.), And 1.5 parts by mass of a vulcanization accelerator (product number: Noxeller NS-P, TS-G, manufactured by Ouchi Shinko Chemical Co., Ltd.), stearic acid as a processing aid (product number: beads, stearic acid Tsubaki, Sanyu Industrial Co., Ltd.) 2 parts by mass) were introduced and kneaded with a Banbury mixer. The rubber after kneading is made into a sheet with TSR, and then 6 parts by mass of sulfur (product number: Seimi OT, manufactured by Rubber Industrial Materials Co., Ltd.) as a cross-linking agent is charged in a rubber blender (thickness 10 mm). Then, it was pulverized to a size of about 3 mm (3 mm mesh pass) to obtain a chip shape, which was heat-treated (150 ° C., 10 minutes) to obtain a chip rubber.

<Rubber floor sheet>
Next, the chip rubber is sprayed on the surface of the rubber sheet and vulcanized (160 ° C., 15 minutes) with a continuous vulcanizer (roof press), and the chip rubber is embedded and integrated in the rubber sheet. A rubber floor sheet (thickness 2.0 mm) was produced.

(Examples 2 to 5 and Comparative Example 1)
The structure of the rubber sheet of the base rubber is the same as that of Example 1 shown in Table 1.

  As shown in Table 2, Examples 2 to 5 differ from Example 1 in the blending amount of cellulose fine fibers. Moreover, the comparative example 1 does not contain a cellulosic fine fiber.

(Test evaluation method)
<Average fiber diameter / fiber diameter distribution>
For each of Examples 1 to 5, after freezing and pulverizing a crosslinked chip rubber sample, the cross section was observed with a transmission electron microscope (TEM), and 50 fibers were arbitrarily selected and the fiber diameter was measured. And the number average was calculated | required and it was set as the average fiber diameter.

  Further, regarding the chip rubber sample of Example 2, the maximum value and the minimum value of the fiber diameter among the 50 cellulose fine fibers were obtained.

<Coefficient of thermal expansion>
The thermal expansion coefficient of the chip rubber was measured by the following method based on JIS K 7197. The thermal expansion coefficients of the base rubber and the chip rubbers of Examples 1 to 5 and Comparative Example 1 were measured at 200 ° C. and room temperature, and the rate of change was evaluated based on the relative value of the measured value obtained for the base rubber as 100. did.

<Tensile strength>
The tensile strength of the rubber floor sheet was measured based on JIS K 6251. The measurement value obtained for the rubber floor sheet of Comparative Example 1 was set to 100, and the relative value was evaluated.

<Slip resistance coefficient>
The slip resistance coefficient D of the rubber floor sheet was measured by a JIS A 1407 pendulum type slip resistance tester.

(Test evaluation results)
Table 3 shows the test results of the fiber diameters of the fine cellulose fibers and the thermal expansion coefficient of the chip rubbers of Examples 1 to 5 and Comparative Example 1.

  About the chip | tip rubber | gum of Examples 1-5, the average fiber diameter of the cellulose fine fiber was 80-100 nm. Moreover, about the chip | tip rubber | gum of Example 2, the minimum value and the maximum value of the fiber diameter of a cellulose fine fiber were 3 nm and 150 nm, respectively.

  According to Table 3, the thermal expansion coefficient of the chip rubber is lower in Examples 1 to 5 than in Comparative Example 1. Further, when Examples 1 to 5 are compared, the thermal expansion coefficient of the chip rubber is reduced with an increase in the content of cellulose fine fibers.

  This is because the chip rubber containing cellulose fine fibers has a small temperature dependency, so that the viscosity difference between the base rubber and the chip rubber can be increased at a high temperature in the vulcanization step. And it can suppress that chip rubber flows and spreads in base rubber in a vulcanization process.

  Next, Table 4 shows the test results of the tensile strength and slip resistance coefficient D of the rubber floor sheet.

  Compared with Comparative Example 1, the tensile strength is increased in Examples 1 to 5. Moreover, the tensile strength is also increasing with the increase in content of the cellulose fine fiber in chip rubber.

  Thereby, it turns out that the intensity | strength of a rubber floor sheet improves by containing a cellulose fine fiber. It can also be seen that the strength can be improved by increasing the cellulose fine fiber content, and the desired strength can be imparted to the rubber floor sheet by adjusting the content.

  According to Table 4, compared with the rubber floor sheet of Comparative Example 1, the slip resistance coefficient D is increased for both the rubber floor sheets of Examples 1 to 5 both when dry and when wet. Thereby, it turns out that the rubber-made floor sheet containing a cellulose fine fiber is excellent in slip resistance.

  Further, the slip resistance coefficient D tends to increase as the contents of cellulose fine fibers in the chip rubber increase as compared with Examples 1 to 5. Furthermore, the rate of increase is higher when wet than when dry. Thus, it can be seen that the rubber floor sheet 1 exhibits excellent slip resistance both when dry and when wet, but exhibits superior slip resistance particularly when wet. Therefore, for example, it can be suitably used as a rubber floor sheet having high slip resistance even in a high humidity environment such as rainy weather.

  The present invention is useful in the technical field of flooring.

1 Rubber floor sheet (floor material)
2 Base rubber (sheet rubber)
3 Chip rubber (chip-shaped rubber material)
4 Cellulose fine fibers

Claims (4)

A flooring material having a sheet-like rubber material and a chip-like rubber material added to the sheet-like rubber material,
At least one of the sheet-like rubber material and the chip-like rubber material is a flooring material containing cellulosic fine fibers. In the flooring material according to claim 1,
The cellulosic fine fibers are contained in the chip-like rubber material,
The chip-like rubber material is a floor material embedded so as to be exposed on the surface of the sheet-like rubber material. In the flooring material according to claim 2,
The cellulosic fine fiber content is 1 to 25 parts by mass with respect to 100 parts by mass of the rubber component of the chip-like rubber material. In the flooring material according to any one of claims 1 to 3,
A flooring in which a fiber diameter distribution range of the cellulosic fine fibers includes 3 to 500 nm.

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