JP2017044057A - Method for manufacturing floor material and floor material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a floor material which: has a foam resin layer made of a material including vinyl chloride series resin; has sufficient strength and adequate flexibility; and is relatively light in weight.SOLUTION: A method for manufacturing a floor material has a process to form a foam resin layer by molding a resin composition, including at least either one of vinyl chloride series resin or vinyl acetate series resin and thermally expandable micro capsules consisting of outer shells made of nitrile series thermoplastic resin and an inclusion component which is included in the outer shells and evaporates when heated, while heating the resin composition at 150 to 200°C. The nitrile series thermoplastic resin is a polymer of a polymerizable component which contains 45 mass% or more of nitrile series monomers. The thermally expandable micro capsule has inner pressure of 0.7 to 1.7 MPa at 150°C and 1.5 to 3.5 MPa at 200°C.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a flooring material having a foamed resin layer containing a vinyl chloride resin and the like, and the flooring material.

In addition to having a certain degree of flexibility and mechanical strength, the flooring material is desired to have a relatively light weight per unit area so that it can be easily transported and constructed. As a comparatively lightweight flooring, the flooring which has a foamed resin layer is mentioned, for example.
Patent Document 1 discloses a method of forming a foamed resin layer by foaming a vinyl chloride resin using a chemical foaming agent as a foaming agent.
However, in the method of foaming a vinyl chloride resin with a chemical foaming agent, there is a problem that a gas generated by the decomposition of the chemical foaming agent can easily escape to the outside, and a foamed resin layer having a low foaming ratio can be obtained. .

JP-A-9-314710

  An object of the present invention is to provide a method for producing a floor material and a floor material that have a foamed resin layer formed from a vinyl chloride resin, etc., have sufficient strength and appropriate flexibility, and are relatively light. It is.

  As described above, a vinyl chloride resin cannot be foamed well with a chemical foaming agent. The inventors of the present invention have made extensive studies on such problems and have found that a vinyl chloride resin can be foamed well by using a specific thermally expandable microcapsule. Furthermore, the present inventors also found that this thermally expandable microcapsule can foam a vinyl acetate resin well.

  The flooring production method of the present invention is vaporized by heating at least one of a vinyl chloride resin and a vinyl acetate resin, an outer shell made of a nitrile thermoplastic resin, and the outer shell. A step of obtaining a foamed resin layer by molding a resin composition comprising a thermally expandable microcapsule comprising an encapsulated component while heating to a temperature of 150 to 200 ° C., and the nitrile thermoplastic The resin is a polymer of a polymerizable component containing 45% by mass or more of a nitrile monomer, and the thermally expandable microcapsule has an internal pressure at 150 ° C. of 0.7 to 1.7 MPa, and an internal pressure at 200 ° C. Is 1.5 to 3.5 MPa.

In a preferred method for producing a flooring material of the present invention, the resin composition further contains an inorganic filler, and the amount of the inorganic filler with respect to the entire resin composition is more than 0 and 68% by mass or less.
In a preferable method for producing a flooring material of the present invention, the amount of the thermally expandable microcapsule with respect to the entire resin composition is 0.1% by mass to 3% by mass.

According to another aspect of the present invention, a flooring is provided.
The floor material of the present invention includes a matrix resin containing at least one of a vinyl chloride resin and a vinyl acetate resin, a plurality of cavities scattered in the matrix resin, and a hollow wall forming the cavity A thermally expandable micro layer having an internal pressure at 150 ° C. of 0.7 to 1.7 MPa and an internal pressure at 200 ° C. of 1.5 to 3.5 MPa. It is comprised from the outer shell of the expansion body of a capsule, and the outer shell of the said expansion body is formed from the polymer of the polymeric component which contains 45 mass% or more of nitrile monomers.

  According to the production method of the present invention, a flooring material having a foamed resin layer having a high expansion ratio can be obtained. The flooring material having such a foamed resin layer is relatively lightweight, and has sufficient strength and appropriate flexibility.

The top view of the flooring which concerns on 1st Embodiment of this invention. The expanded sectional view which cut | disconnected the flooring with the II-II line | wire of FIG. The expanded sectional view of the flooring concerning a 2nd embodiment (cutting in the same portion as the II-II line of Drawing 1). The expanded sectional view of the flooring concerning a 3rd embodiment (cutting in the same portion as the II-II line of Drawing 1). The expanded sectional view of the flooring concerning a 4th embodiment (cutting in the same portion as the II-II line of Drawing 1). The expanded sectional view of the flooring concerning a 5th embodiment (cutting in the same portion as the II-II line of Drawing 1). The expanded reference sectional view of a foamed resin layer. The schematic side view of the manufacturing process of a flooring.

Hereinafter, the present invention will be described with reference to the drawings as appropriate.
In this specification, the “upper surface” or “upper” of a layer refers to the surface or direction far from the floor surface on which the flooring is laid, and the “lower surface” or “lower” refers to the opposite side (the flooring The surface or direction on the side near the floor to be laid.
In the present specification, a numerical range represented by “to” means a numerical range including numerical values before and after “to” as a lower limit value and an upper limit value. When a plurality of lower limit values and a plurality of upper limit values are separately described, an arbitrary lower limit value and an arbitrary upper limit value can be selected and set to a range connected by “˜”.
In addition, it should be noted that dimensions such as thickness and size in each drawing are different from actual ones.

[Laminated structure of flooring]
FIG. 1 is a plan view of the flooring of the first embodiment, and FIG. 2 is an enlarged cross-sectional view of the flooring.
As shown in FIG. 1, the flooring 1 is formed in a long band shape in plan view. In the present specification, the long band shape is a rectangular shape in which the length in one direction is sufficiently longer than the length in the other direction (the other direction is perpendicular to the one direction). Is at least twice as long as the length in the other direction, preferably at least four times. The long belt-like flooring 1 is usually wound around a roll and stored and transported, and is cut into a desired shape and used at a construction site. But the flooring 1 of this invention is not restricted to a elongate strip | belt-shaped sheet | seat, The tile formed in sheet shape, such as planar view square shape, may be sufficient (not shown).

The long belt-like flooring 1 is formed to have a predetermined length such as a width of 800 mm to 4000 mm, for example, and the length is, for example, 2 m to 300 m. The flooring 1 formed in a sheet shape has, for example, a length and width of 100 mm to 4000 mm, respectively. The sheet-like flooring 1 is generally square in plan view with a side length of 50 cm, but may be rectangular, hexagonal, etc. 10 cm long by 90 cm wide, and the size and shape are particularly limited. Not.
The top surface of the flooring 1 may be embossed (not shown) as needed to give a concavo-convex pattern. Moreover, the embossing may be given to the lower surface of the flooring 1 or the upper surface and lower surface of the flooring 1 as needed.

The flooring 1 of the present invention has a foamed resin layer and has flexibility. As the degree of flexibility of the flooring 1, for example, the flooring 1 of the present invention can be wound around a core material having a diameter of 10 cm in a roll shape.
The flooring 1 of the present invention may be composed only of a foamed resin layer, but is usually a laminated structure having a foamed resin layer 7 and any other layer.
For example, the flooring 1 shown in FIG. 2 includes a scratch-preventing layer 2, a protective layer 3, a decorative layer 4, a resin layer 5, a first base layer 61, a foamed resin layer 7, and a second base layer in order from the top. A laminate composed of 62. These layers are joined and integrated.
3 to 6 are cross-sectional views of the flooring 1 according to the second to fifth embodiments. The plan view of the flooring 1 according to the second to fifth embodiments is the same as FIG.
The flooring material 1 of 2nd Embodiment shown in FIG. 3 is the damage prevention layer 2, the protective layer 3, the decorative layer 4, the foamed resin layer 7, the 1st base material layer 61, the resin layer 5, and 2nd in order from the upper side. This is a laminate composed of the base material layer 62. These layers are joined and integrated.
The flooring material 1 of 3rd Embodiment shown in FIG. 4 is a damage prevention layer 2, the protective layer 3, the decorative layer 4, the resin layer 5, the 1st base material layer 61, the foaming resin layer 7, and 2nd from an upper side. It is a laminate composed of a base material layer 62 and a backing layer 63. These layers are joined and integrated. Examples of the backing layer include adsorption layers such as rubber, felt, and foamed acrylic resin layer.
The flooring 1 of 4th Embodiment shown in FIG. 5 is the damage prevention layer 2, the protective layer 3, the decorative layer 4, the foaming resin layer 7, the 1st base material layer 61, the foaming resin layer 7, and the 1st from the upper side. It is a laminate composed of two base material layers 62. These layers are joined and integrated.
A flooring material 1 according to the fifth embodiment shown in FIG. 6 is a laminated body including an anti-scratch layer 2, a protective layer 3, a decorative layer 4, a foamed resin layer 7, and a second base material layer 62 in order from the upper side. These layers are joined and integrated. In addition, you may provide a backing layer similarly to FIG. 4 in the lowermost surface of the flooring 1 shown in FIG.2, FIG.3, FIG.5 and FIG.
Although not particularly illustrated, in the flooring 1 of the first to fifth embodiments, at least one layer selected from the scratch-preventing layer 2, the protective layer 3, and the decorative layer 4 may be omitted. At least one layer selected from the layer 61 and the second base material layer 62 may be omitted.

<Foamed resin layer>
The foamed resin layer 7 includes a matrix resin containing at least one of a vinyl chloride resin and a vinyl acetate resin, a plurality of cavities scattered in the matrix resin, and a hollow wall portion forming the cavity. And a hollow wall portion made of a nitrile thermoplastic resin.
Specifically, FIG. 7 is a cross-sectional view in which only the foamed resin layer 7 is partially enlarged. As shown in FIG. 7, the foamed resin layer 7 has a plurality of hollow portions 7a therein. The hollow portions 7 a are scattered in the matrix resin 71. The cavity 7 a is an infinite number of spaces formed in the matrix resin 71. Although not particularly illustrated, a part of the cavity may be present on the upper surface or the lower surface of the foamed resin layer. In this case, the foamed resin layer has a recess corresponding to the cavity on the upper surface or the lower surface. .
The three-dimensional shape of the hollow portion 7a is not particularly limited, and examples thereof include a hollow substantially elliptical sphere, a hollow substantially spherical shape, and a hollow substantially rectangular parallelepiped shape. In the present invention, the “substantially” shape means a shape allowed in the technical field to which the present invention belongs. The three-dimensional “substantially oval, substantially spherical” of the hollow portion 7a includes, for example, a shape including a convex surface that is a part of a curved surface bulging or a concave surface that is concave, and a shape in which a part of the curved surface is a flat surface. . Further, the “substantially rectangular parallelepiped shape” includes, for example, a shape including a convex surface in which a part of a plane swells or a concave concave surface, and a shape in which corners draw an arc shape.

The hollow portion 7 a is a space surrounded by the hollow wall portion 73. In other words, the hollow wall portion 73 forms the cavity 7a. The hollow wall 73 is composed of an outer shell of an expanded body of a microcapsule having a thermal expansibility of an internal pressure at 150 ° C. of 0.7 to 1.7 MPa and an internal pressure at 200 ° C. of 1.5 to 3.5 MPa. ing. The outer shell of the expanded body is formed from a nitrile thermoplastic resin which is a polymer of a polymerizable component containing 45% by mass or more of a nitrile monomer. Details of such thermally expandable microcapsules will be described later.
However, the present invention is not limited to the case where all the hollow portions 7a are formed by the hollow wall portion 73 constituted by the outer shell of the expansion body. For example, as shown by reference numeral 74, the closed inner wall of the matrix resin 71 is Some hollow portions 7a may be formed.
The size of the hollow portion 7a is, for example, 50 μm to 200 μm, preferably 60 μm to 150 μm. The size of the hollow portion can be measured with a 3D digital fine scope “VC7700” manufactured by OMRON Corporation.

The foamed resin layer 7 may contain other components besides the expanded body of the matrix resin and the thermally expandable microcapsule. Examples of the other components include plasticizers, fillers, stabilizers, processing aids, fungicides, flame retardants, ultraviolet absorbers, colorants such as pigments, various additives such as antioxidants and lubricants. For example, the foamed resin layer 7 includes at least a plasticizer as an additive, or at least a plasticizer and a filler as an additive, in addition to the matrix resin and the expanded body of the thermally expandable microcapsule.
Although the thickness of the foamed resin layer 7 is not specifically limited, For example, it is 0.5 mm-5 mm, Preferably it is 1 mm-3 mm.

<Scratch prevention layer>
The scratch-preventing layer 2 is a layer that is provided to provide the flooring 1 with dirt removal and the abrasion resistance and scratching resistance on the upper surface of the flooring 1 together with the protective layer 3. The scratch preventing layer 2 is provided as necessary. The scratch-preventing layer 2 may be transparent or opaque, but is preferably transparent in order to make the design of the decorative layer 4 visible.
The scratch preventing layer 2 is formed of, for example, a resin material. The resin material is not particularly limited, but is preferably formed from a relatively hard resin layer. As the resin material for the scratch-preventing layer 2, it is preferable to use a curable resin from the viewpoint of good workability. Furthermore, it is more preferable to use an ionizing radiation curable resin because it is difficult to cause thermal damage to the protective layer 3. It is more preferable to use an ultraviolet curable resin because of its versatility. Examples of the curable resin include thermosetting resins and resins that are cured by non-ionizing radiation, in addition to ionizing radiation curable resins such as ultraviolet curable resins. Although the thickness of the damage prevention layer 2 is not specifically limited, For example, they are 1 micrometer-100 micrometers, Preferably they are 5 micrometers-70 micrometers, More preferably, they are 10 micrometers-50 micrometers.

<Protective layer>
The protective layer 3 is a layer provided to make it possible to easily remove the dirt attached to the flooring 1. The protective layer 3 is provided as necessary. The protective layer 3 may be transparent or opaque, but is preferably transparent for the same reason as the scratch-preventing layer 2.
The protective layer 3 is made of, for example, a resin material. As the resin material, a thermoplastic resin is generally used. Examples of the thermoplastic resin include vinyl chloride resins such as vinyl chloride and vinyl chloride-vinyl acetate copolymers; polyolefin resins; urethane resins; vinyl acetate resins such as ethylene-vinyl acetate copolymers; Examples thereof include acrylic resins such as resins; polyamide resins; ester resins; various elastomers such as various elastomers such as olefin elastomers and styrene elastomers; and rubbers. These can be used alone or in combination of two or more. A resin mainly composed of a vinyl chloride resin is preferable because it is firmly bonded to the decorative layer 4, the resin layer 5, or the foamed resin layer 7. The thickness of the protective layer 3 is not specifically limited, For example, it is 0.03 mm-1 mm.

<Makeup layer>
The decorative layer 4 is a layer that imparts a design to the flooring 1. The decorative layer 4 is provided as necessary.
Examples of the decorative layer 4 include a transfer layer, a design printing layer, a design printing sheet, and a thermoplastic resin layer to which design properties are imparted. However, the decorative layer 4 is not limited to these exemplary layers, and any other layer can be used as long as it can express a design.
The transfer layer is composed of a transfer film formed by printing and solidifying a printing ink on a base material such as release paper and then peeling the solidified printing ink. The decorative layer 4 made of the transfer layer is formed by transferring to the lower surface of the protective layer 3 or the like. The design printing layer is composed of a layer in which printing ink is directly printed on the lower surface of the protective layer 3 and solidified. The decorative layer 4 made of a design printed sheet is formed by joining a sheet that has been subjected to design printing in advance to the lower surface of the protective layer 3 or the like. The thermoplastic resin layer imparted with designability is a layer that itself can be designed. The thermoplastic resin layer has (1) a design property imparted by the color of the resin itself, (2) a colorant is mixed, and the design property is imparted by the color of the colorant and how it is mixed. (3) When resin chips are mixed and design properties are given by the color, shape, dispersion method, etc. of the resin chips, (4) Colorants having different colors and resin chips are mixed, When designability is imparted depending on the color or mixing method, etc. The decorative layer 4 made of a thermoplastic resin layer is formed by laminating and bonding the thermoplastic resin layer to the lower surface of the protective layer 3 or the like. Although the thickness of the said decorative layer 4 is not specifically limited, For example, they are 0.5 micrometer-1 mm, Preferably they are 0.01 mm-0.8 mm. In particular, the thickness of the decorative layer 4 made of a transfer layer or a design printing layer is 0.5 μm to 0.5 mm.

<Resin layer>
The resin layer 5 is a layer constituting the strength and weight of the flooring 1. The resin layer 5 is provided as necessary.
The resin layer 5 may be foamed or may not be foamed. The resin layer 5 in the illustrated example is not foamed (non-foamed). Examples of the material for forming the resin layer 5 include those exemplified in the above section <Protective layer>, and since the resin layer 5 is firmly bonded to the decorative layer 4 or the like, a resin mainly composed of a vinyl chloride resin is preferable. . In addition, by including a colorant such as a pigment in the resin layer 5, the resin layer 5 to which design properties are imparted can be configured depending on the color or mixing method of the colorant. When using the resin layer 5 to which such design properties are imparted, the decorative layer 4 can be omitted. The thickness of the resin layer 5 is not specifically limited, For example, it is 0.05 mm-1.0 mm, Preferably it is 0.1 mm-0.8 mm.

<First base material layer and second base material layer>
The first base material layer 61 and the second base material layer 62 are layers for suppressing dimensional changes or warpage of the flooring 1 due to shrinkage or expansion over time. The 1st base material layer 61 and the 2nd base material layer 62 are provided as needed.
Although the 1st base material layer 61 and the 2nd base material layer 62 are not specifically limited, Conventionally well-known fiber sheets, such as a nonwoven fabric, a woven fabric, paper, felt, can be used independently, respectively. The material of the fibers constituting the nonwoven fabric or the woven fabric is not particularly limited, and examples thereof include synthetic resin fibers such as polyester and polyolefin; inorganic fibers such as glass and carbon; natural fibers and the like. Since the 1st base material layer 61 arrange | positioned in the thickness direction intermediate | middle of the flooring 1 can suppress especially the shrinkage | contraction and expansion | swelling of the flooring 1 with time, it is using the nonwoven fabric or woven fabric containing inorganic fibers, such as glass. preferable. Since the 2nd base material layer 62 arrange | positioned at the lower surface side or lowermost surface of the flooring 1 can suppress the upper curvature of the flooring 1, it is preferable to use the nonwoven fabric or woven fabric containing a synthetic resin fiber. Basis weight of the first base layer 61 and the second base layer 62 is not particularly limited, each independently, for ^example, a ^{30g / m 2 ~50g / m 2} . Note that only one of the first base material layer 61 and the second base material layer 62 may be provided.

[Manufacturing method of flooring]
The method for producing a flooring of the present invention includes a preparation step of preparing a resin composition containing at least one of a vinyl chloride resin and a vinyl acetate resin and a thermally expandable microcapsule, extruding the composition while heating, and foaming A molding step of molding the resin layer.
The manufacturing method of the flooring of this invention may have other processes other than a preparation process and a formation process. For example, the flooring 1 includes, as described above, the foamed resin layer 7, the scratch preventing layer 2, the protective layer 3, the decorative layer 4, the resin layer 5, the first base material layer 61, and the second base material layer 62. At least one selected layer is laminated. The manufacturing method of this invention may have these lamination processes. Furthermore, you may have an embossing process.
Each of these steps may be performed in series on one production line, or one or more steps selected from the above steps may be performed on one line and the remaining steps may be performed on another one or Two or more lines may be used. Further, all of the steps may be performed by one practitioner, or one or more steps selected from the steps may be performed by one practitioner, and the remaining steps may be performed by another practitioner. The person may go.
FIG. 8 is a schematic side view schematically showing each step of the flooring manufacturing method. The production line used in the production method of FIG. 8 is a case where a series of processes from the laminating process of each layer to the production of a long strip flooring is performed.

<Preparation process of resin composition>
The preparation step of the resin composition is a step of obtaining a resin composition by mixing a matrix resin containing at least one of a vinyl chloride resin and a vinyl acetate resin and an unexpanded thermally expandable microcapsule. .
The thermally expandable microcapsules before expansion together with the matrix resin are put into a mixing device such as a mixer, and the pulverized product is melted. If necessary, fillers, plasticizers, and additives other than fillers and plasticizers are placed in the mixing device. Hereinafter, additives other than the filler and the plasticizer are referred to as other additives.

(Thermal expansion microcapsule)
The heat-expandable microcapsule used in the present invention is composed of an outer shell made of a thermoplastic resin, and an encapsulated component that is encapsulated therein and vaporizes when heated.
The outer shell is made of a nitrile thermoplastic resin. The nitrile thermoplastic resin refers to a polymer obtained by polymerizing a polymerizable component containing 45% by mass or more of a nitrile monomer. The thermally expandable microcapsule has an internal pressure of 0.7 to 1.7 MPa when heated to 150 ° C. and an internal pressure of 1.5 to 3.5 MPa when heated to 200 ° C. Have
By using the outer shell and the microcapsules having thermal expansibility, destruction of the outer shell is suppressed when mixing with the matrix resin, while a foamed resin layer having a high expansion ratio can be formed in the molding step. In particular, when a material containing a matrix resin and an inorganic filler and a heat-expandable microcapsule are mixed, the outer shell tends to be destroyed by contacting the inorganic filler, but the heat-expandable microcapsule was used. In this case, the outer shell can be effectively prevented from being broken.

  The present inventors have prepared a resin obtained by mixing a matrix resin containing at least one of a vinyl chloride resin and a vinyl acetate resin, an inorganic filler added as necessary, and various thermally expandable microcapsules. Experiments for forming a foamed resin layer using the composition were repeated. As a result, in the case of using the thermally expandable microcapsule having the outer shell of the thermoplastic resin other than the nitrile-based thermoplastic resin, even if the inclusion component having the specific internal pressure as described above is used, the matrix When a material containing a resin and a thermally expandable microcapsule are mixed, the thermally expandable microcapsule expands, making it difficult to extrude the resin composition and reducing the expansion ratio of the resulting foamed resin layer. there were. Only when the nitrile thermoplastic resin outer shell and the thermally expandable microcapsule having the specific internal pressure are used, it does not expand when mixed with the material containing the matrix resin, and a foamed resin layer having a high expansion ratio is obtained. Can be.

  The polymerizable component constituting the nitrile thermoplastic resin is essentially a monomer component having one ethylenically unsaturated bond, and a polymerizable monomer (crosslinking agent) having two or more ethylenically unsaturated bonds. It is a component that may contain. Therefore, the nitrile thermoplastic resin constituting the outer shell of the thermally expandable microcapsule used in the present invention contains a polymerizable component (preferably containing 45% by mass or more of a nitrile monomer and a crosslinking agent). Obtained by polymerization (in the presence of a polymerization initiator). Note that a thermally expandable microcapsule composed of an outer shell made of a nitrile thermoplastic resin may be referred to as a nitrile thermally expandable microcapsule.

The nitrile monomer is not particularly limited as long as it is a monomer having a nitrile group, and examples thereof include acrylonitrile, methacrylonitrile, and fumaronitrile.
As a monomer component, you may include other monomers other than a nitrile-type monomer. Examples of other monomers include vinyl halide monomers such as vinyl chloride; vinylidene halide monomers such as vinylidene chloride; vinyl halides such as vinyl acetate, vinyl propionate, and vinyl butyrate. Vinyl ester monomers; (meth) acrylic acid amide monomers such as acrylamide and methacrylamide; maleimide monomers such as N-phenylmaleimide and N-cyclohexylmaleimide; styrene, α-methylstyrene, vinyltoluene Styrenic monomers such as acrylic acid, methacrylic acid, fumaric acid, itaconic acid and other carboxyl group-containing monomers; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-methylol ( Monomers containing reactive functional groups such as (meth) acrylamide; methyl (meta) Acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, Examples include (meth) acrylic acid ester monomers such as phenyl (meth) acrylate, isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate. (Meth) acrylate means acrylate or methacrylate, and (meth) acryl means acryl or methacryl.

  The nitrile thermoplastic resin constituting the outer shell of the thermally expandable microcapsule is composed of a polymer obtained by polymerizing a polymerizable component containing the nitrile monomer as described above. In order to improve the strength of the thermoplastic resin constituting the outer shell of the thermally expandable microcapsule, the weight ratio of the nitrile monomer in the polymerizable component is 45% by mass or more, preferably 50 to 99.9. It is 70 mass%, More preferably, it is 70-99.9 mass%, More preferably, it is 75-99.9 mass%. When the weight ratio is less than 45% by mass, the strength of the thermoplastic resin forming the outer shell is lowered, and when the resin composition containing the matrix resin and the thermally expandable microcapsule is used for extrusion, The expandable microcapsule is destroyed and a foamed resin layer having a desired expansion ratio cannot be obtained.

The polymerizable component for forming the outer shell of the nitrile-based thermally expandable microcapsule contains a polymerizable monomer (crosslinking agent) having two or more polymerizable double bonds in addition to the above monomer. Also good. By polymerizing using a crosslinking agent, a decrease in the retention rate (encapsulation retention rate) of the encapsulated component encapsulated in the outer shell during thermal expansion is suppressed, and the thermally expanded microcapsules can be effectively expanded.
The crosslinking agent is not particularly limited. For example, aromatic divinyl compounds such as divinylbenzene; allyl methacrylate, triacryl formal, triallyl isocyanate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, Ethylene glycol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, PEG # 200 di (meth) acrylate, PEG # 600 di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri Examples thereof include polyfunctional (meth) acrylate compounds such as (meth) acrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. These crosslinking agents may be used alone or in combination of two or more.
The blending amount of the crosslinking agent is not particularly limited, but the weight ratio of the crosslinking agent in the polymerizable component is preferably 0.01 to 5.0% by mass, more preferably 0.05 to 2.0% by mass, Especially preferably, it is 0.1-1.0 mass%.

The method for producing the nitrile-based thermally expandable microcapsule of the present invention is not limited, but it is preferable to include a polymerization initiator in an oily mixture containing a polymerizable component and polymerize the polymerizable component in the presence of the polymerization initiator. .
Although there is no limitation in particular as a polymerization initiator, The peroxide, an azo compound, etc. which are used very generally can be mentioned.

Examples of the peroxide include peroxydicarbonates such as diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, dibenzylperoxydicarbonate; lauroyl peroxide Diacyl peroxides such as 2,2-bis (t-butylperoxy) butane; dialkyl peroxides such as dicumyl peroxide and di-t-butyl peroxide; t-hexyl Peroxyesters such as peroxypivalate and t-butylperoxyisobutyrate can be mentioned.
Examples of the azo compound include 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4- Dimethylvaleronitrile), 2,2'-azobis (2-methylpropionate), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), etc. Can be mentioned.

  These polymerization initiators may be used alone or in combination of two or more. Although there is no limitation in particular about the compounding quantity of a polymerization initiator, Preferably it is 0.05-10 mass parts with respect to 100 mass parts of said polymeric components, More preferably, it is 0.1-8 mass parts. .

The encapsulated component is a component that is vaporized when heated, and by being encapsulated in an outer shell made of a nitrile thermoplastic resin, the thermally expandable microcapsule as a whole is thermally expandable (the property that the entire microcapsule expands when heated) ).
From the viewpoint of increasing the expansion ratio of the foamed resin layer by extruding the resin composition containing the matrix resin, the internal pressure of the thermally expandable microcapsules at 150 ° C. needs to be 0.7 to 1.7 MPa. When the internal pressure at 150 ° C. is lower than 0.7 MPa, the expansion ratio of the thermally expandable microcapsules is decreased, and the expansion ratio of the obtained foamed resin layer is decreased. When the internal pressure is higher than 1.7 MPa, the heat-expandable microcapsule expands greatly when extruding or mixing with the matrix resin, and the thickness of the outer shell of the heat-expandable microcapsule is reduced. In addition, the outer shell is destroyed by contact with an inorganic filler or the like added as necessary, and a foamed resin layer having a desired expansion ratio cannot be obtained. The internal pressure at 150 ° C. is preferably 0.8 to 1.6 MPa, more preferably 0.8 to 1.3 MPa, still more preferably 0.9 to 1.2 MPa, and particularly preferably 0.9 to 1.1 MPa. is there.

  Moreover, the internal pressure of the thermally expansible microcapsule in 200 degreeC needs to be 1.5-3.5 Mpa from the point which raises the expansion ratio of a foamed resin layer. When the internal pressure at 200 ° C. is lower than 1.5 MPa, the expansion ratio of the thermally expandable microcapsules becomes low, and the expansion ratio of the foamed resin layer becomes low. On the other hand, when the internal pressure at 200 ° C. is higher than 3.5 MPa, the heat-expandable microcapsule greatly expands when being extruded or mixed with the matrix resin, and the thickness of the outer shell of the heat-expandable microcapsule is reduced, The outer shell is destroyed by contact with a matrix resin or an inorganic filler added as necessary at the time of extrusion molding, and a foamed resin layer having a desired expansion ratio cannot be obtained. The internal pressure at 200 ° C. is preferably 1.6 to 3.3 MPa, more preferably 1.6 to 2.7 MPa, still more preferably 1.7 to 2.6 MPa, and particularly preferably 1.7 to 2.5 MPa. is there.

  Here, in the present invention, the internal pressure of the thermally expandable microcapsule at 150 ° C. (or 200 ° C.) means the vapor pressure of the entire encapsulated component. When the encapsulated component is composed of a plurality of components, the internal pressure of the thermally expandable microcapsule at 150 ° C. (or 200 ° C.) is different from that of each component with respect to the vapor pressure of 150 ° C. (or 200 ° C.) of each component. It is a value calculated by multiplying the mole fractions of the two and totaling the multiplied values.

  The encapsulated component (vaporizing component) encapsulated in the outer shell of the thermally expandable microcapsule of the present invention is a component that is vaporized by heating, so long as it becomes the internal pressure of the specific thermally expandable microcapsule. There is no particular limitation, for example, propane, butane, pentane, hexane, heptane, octane, nonane, decane, isobutane, isopentane, isohexane, isoheptane, isooctane, isononane, isodecane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, Cyclooctane, neopentane, dodecane, isododecane, cyclotridecane, hexylcyclohexane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nanodecane, isotridecane, 4-methyldodecane, isote Radecane, isopentadecane, isohexadecane, 2,2,4,4,6,8,8-heptamethylnonane, isoheptadecane, isooctadecane, isonanodecane, 2,6,10,14-tetramethylpentadecane, cyclotridecane, heptyl Examples include cyclohexane, n-octylcyclohexane, cyclopentadecane, nonylcyclohexane, decylcyclohexane, pentadecylcyclohexane, hexadecylcyclohexane, heptadecylcyclohexane, octadecylcyclohexane, and the like. The inclusion component may be used alone or in combination of two or more.

  The weight ratio of the encapsulated component in the entire thermally expandable microcapsule is not particularly limited, but is preferably 5 to 30% by mass, more preferably 10 to 26% by mass, and most preferably 15 to 23% by mass. When the weight ratio of the encapsulated component to the entire thermally expandable microcapsule is less than 5% by mass, the expansion ratio of the thermally expandable microcapsule becomes low, and a foamed resin layer having a desired expansion ratio cannot be obtained. It may be necessary to add more capsules. On the other hand, when the weight ratio of the encapsulated component to the entire thermally expandable microcapsule exceeds 30% by mass, the encapsulated component leaks from the thermally expandable microcapsule when the thermally expandable microcapsule and the material containing the matrix resin are mixed. In addition, the foaming ratio of the obtained foamed resin layer may be lowered.

  The average particle size of the thermally expandable microcapsule is not particularly limited, but is preferably 15 to 50 μm, more preferably 20 to 40 μm. When the average particle diameter is smaller than 15 μm, the expansion performance of the thermally expandable microcapsule is lowered, and the expansion ratio of the foamed resin layer may be decreased. On the other hand, when the average particle size is larger than 50 μm, when the resin composition containing the matrix resin and the thermally expandable microcapsules is extruded, the thermally expandable microcapsules are destroyed, and a foamed resin layer having a desired expansion ratio is obtained. There is a risk of not being able to.

The expansion start temperature (Ts) of the thermally expandable microcapsule is not particularly limited as long as the thermally expandable microcapsule does not expand when the material containing the matrix resin and the thermally expandable microcapsule are mixed. Preferably it is 120-190 degreeC, More preferably, it is 140-190 degreeC, More preferably, it is 150-190 degreeC, Most preferably, it is 155-187 degreeC. When the expansion start temperature (Ts) of the thermally expandable microcapsule is less than 120 ° C., the thermally expandable microcapsule expands when the material containing the matrix resin and the thermally expandable microcapsule are mixed, and a good foamed resin layer May not be obtained.
The maximum expansion temperature (Tmax) of the thermally expandable microcapsule used in the present invention is not particularly limited, but is preferably 180 ° C to 200 ° C, more preferably 182 ° C to 197 ° C. When the maximum expansion temperature (Tmax) is less than 180 ° C., the heat-expandable microcapsule has low heat resistance, and the heat-expandable microcapsule expands when the material containing the matrix resin and the heat-expandable microcapsule are mixed, There is a possibility that a good foamed resin layer cannot be obtained. On the other hand, if the maximum expansion temperature (Tmax) is higher than 200 ° C., the heat-expandable microcapsules have high heat resistance, and thus there is a possibility that a foamed resin layer having a desired expansion ratio cannot be obtained.
In addition, the measuring method of expansion start temperature (Ts) and maximum expansion temperature (Tmax) is explained in full detail in the column of the following Example.
In addition, as a thermally expansible microcapsule used by this invention, you may use a commercially available nitrile type thermally expansible microcapsule.

(Matrix resin)
In the present invention, the matrix resin contains at least one of a vinyl chloride resin and a vinyl acetate resin.
The vinyl chloride resin includes a vinyl chloride monomer homopolymer, a copolymer of a vinyl chloride monomer and a monomer copolymerizable with vinyl chloride, and the like.
The monomer copolymerizable with the vinyl chloride monomer is not particularly limited, and examples thereof include vinyl acetate, acrylonitrile, vinylidene chloride, ethylene, vinyl ether, maleic acid, maleic anhydride, acrylic acid ester, vinyl fluoride, and maleimide. It is done. These may be used alone or in combination of two or more. In this specification, the vinyl chloride-vinyl acetate copolymer is included in the category of vinyl chloride resin.

As the vinyl chloride resin, those produced by an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, a bulk polymerization method, or the like can be used. A vinyl chloride resin obtained by an emulsion polymerization method or a suspension polymerization method is preferred because it is easy to process and handle. These vinyl chloride resins may be used alone or in combination of two or more.
The paste vinyl chloride resin is, for example, a paste-like vinyl chloride resin obtained by an emulsion polymerization method, and the viscosity can be appropriately adjusted with a plasticizer. The paste vinyl chloride resin is a fine powder having a particle diameter of 0.1 to 10 μm (preferably 1 to 3 μm) composed of a large number of fine particle aggregates. Preferably, the surface of the fine powder is coated with a surfactant. ing. The average degree of polymerization of the paste vinyl chloride resin is preferably about 1000 to 2000.
The suspension vinyl chloride resin is, for example, a vinyl chloride resin obtained by a suspension polymerization method. The suspension vinyl chloride resin is a fine powder having a particle size of preferably 20 μm to 100 μm. The average degree of polymerization of the suspension vinyl chloride resin is preferably about 700 to 1500, more preferably about 700 to 1100, and still more preferably about 700 to 1000. However, the particle diameter is the median diameter (D50) in the volume-based particle size distribution.
Each vinyl chloride resin preferably has a K value of about 60 to 95, and more preferably has a K value of about 65 to 80.

Examples of the vinyl acetate resin include a homopolymer of vinyl acetate monomer, a copolymer of vinyl acetate monomer and a monomer copolymerizable with vinyl acetate, and a saponified product thereof. Specifically, examples of the vinyl acetate resin include ethylene-vinyl acetate resin (EVA), polyvinyl butyral resin (PVB), ethylene-vinyl alcohol resin (EVOH), and the like. These vinyl acetate resins may be used alone or in combination of two or more.
The vinyl chloride resin and the vinyl acetate resin may be used independently in combination with a virgin material and a recycled material.

The matrix resin may contain at least one of vinyl chloride resin and vinyl acetate resin, but preferably contains at least vinyl chloride resin. However, the matrix resin may contain other resin components on the condition that at least one of a vinyl chloride resin and a vinyl acetate resin is included. When the matrix resin contains other resin components, the amount of the other resin components is 20% by mass or less, preferably 10% by mass or less when the entire matrix resin is 100% by mass.
In another aspect, the matrix resin is made of at least one of a vinyl chloride resin and a vinyl acetate resin, and preferably only a vinyl chloride resin. However, “consisting only of the above” means that a very small amount of components inevitably contained is allowed and a significant amount is excluded.

(Additive)
The inorganic filler is not particularly limited, and inorganic fillers conventionally added to vinyl chloride resins can be used as appropriate. For example, calcium carbonate, calcium oxide, barium carbonate, magnesium hydroxide, aluminum hydroxide And various inorganic fillers such as clay, talc and mica.
The plasticizer is not particularly limited, and those conventionally added to vinyl chloride resins can be used as appropriate. For example, dioctyl phthalate (DOP), dibutyl phthalate (DBP), butyl octyl phthalate (BOP) Etc.
Other additives include stabilizers, processing aids, fungicides, flame retardants, UV absorbers, pigments and other colorants, antioxidants, lubricants and the like.

(mixture)
By mixing the matrix resin, the heat-expandable microcapsules before expansion, and additives as necessary, a resin composition that is a raw material for forming the foamed resin layer can be obtained.
The amount of the heat-expandable microcapsule is not particularly limited, but if it is too small, there is a possibility that a well-foamed foamed resin layer cannot be obtained. If it is too large, the amount of other components is relatively small. From this viewpoint, when the total resin composition is 100% by mass, the amount of the thermally expandable microcapsule is preferably 0.1% by mass to 3% by mass, and further 0.2% by mass to 2%. More preferably, it is 5 mass%.

The resin composition may or may not contain a filler, a plasticizer, and other additives. When a matrix resin containing a vinyl chloride resin is used, it is preferable to add a plasticizer, and it is more preferable to add a plasticizer and a filler.
When the resin composition contains a plasticizer, the amount is not particularly limited. However, if the amount is too small, the flexibility of the foamed resin layer is insufficient. If the amount is too large, the strength of the foamed resin layer may be insufficient. From this viewpoint, when the entire resin composition is 100% by mass, the amount of the plasticizer is preferably 10% by mass to 30% by mass, and more preferably 15% by mass to 25% by mass. preferable.
When the resin composition contains a filler, the amount is not particularly limited, but if it is too large, the foamed resin layer may become brittle and easily cracked, and the thermal expansion in which the outer shell is destroyed during mixing of the resin composition There is a possibility that the generation rate of conductive microcapsules is relatively high. From this viewpoint, when the total resin composition is 100% by mass, the amount of the filler is preferably more than 0 and 68% by mass or less, more preferably 5% by mass to 65% by mass, and more preferably 15% by mass. -62 mass% is further more preferable, and 30 mass%-60 mass% is especially preferable.
The amount of other additives such as a stabilizer is not particularly limited, and is 0.5% by mass to 3% by mass when the entire resin composition is 100% by mass.

The matrix resin and the heat-expandable microcapsules, and fillers, plasticizers, and other additives that are added as necessary are put into a mixing apparatus and kneaded. When mixed for a predetermined time, a powdery resin composition is obtained. They may be placed in the mixing device at the same time or sequentially.
The mixing may be performed at room temperature, but the material itself generates heat and the temperature rises while the material is kneaded. In the mixing step, it is preferable to control this temperature. That is, a target temperature range at the time of mixing is set in advance, kneading until that temperature is reached, and further kneading while maintaining the temperature range. Hereinafter, this target temperature may be referred to as a mixing scheduled temperature. In addition, when the mixing expected temperature is not reached during the kneading, it is preferable to apply heat until the temperature is reached.
The expected mixing temperature is, for example, a melting temperature of the matrix resin of −10 ° C. or higher, preferably higher than the melting temperature of the matrix resin, more preferably higher than the melting temperature of the matrix resin and expansion of the thermally expandable microcapsules. It is lower than the starting temperature, and more preferably, the melting temperature of the matrix resin + 10 ° C. to the expansion starting temperature of the thermally expandable microcapsule −10 ° C. Specifically, it is 125 ° C to 175 ° C, preferably 135 ° C to 175 ° C, more preferably 140 ° C to 175 ° C, still more preferably 145 ° C to 170 ° C, and particularly preferably 150 ° C. ~ 170 ° C. By mixing the material containing the heat-expandable microcapsules at the planned mixing temperature, the outer shell can be softened to such an extent that the strength is not impaired without greatly expanding the heat-expandable microcapsules.
The thermally expandable microcapsules may be added from the beginning of mixing, but in order to prevent expansion of the thermally expandable microcapsules, it is preferable to mix them in the middle.
Although the obtained powdery resin composition may be used as it is, it is preferable to screen the powdery resin composition in order to form a homogeneous foamed resin layer. For example, the powdery resin composition is passed through a 12 mesh screen. The forming material that has passed through the sieve is a powdery substance having a particle size of approximately 1.5 mm or less. In the present specification, the sieve is based on JISZ8801-1: 2006.

<Molding process of resin composition>
The molding step is a step of molding the foamed resin layer by extruding the resin composition while heating.
The resin composition is put into a hopper of an extrusion molding machine. A conventionally well-known thing should just be used for an extrusion molding machine.
The processing temperature at the time of extrusion is 150 ° C to 200 ° C. The heated resin composition is extruded into a sheet form from the die of the extruder, thereby forming a foamed resin layer having an expanded body in which the thermally expandable microcapsules are greatly expanded in the matrix resin. By extruding at the processing temperature, the outer shell of the microcapsule is hardly broken and the thermally expandable microcapsule is greatly expanded, and a foamed resin layer having a high expansion ratio can be obtained.

As described above, since the outer shell of the thermally expandable microcapsule is softened during the mixing process, when the processing temperature of the molding process exceeds the maximum expansion temperature of the thermally expandable microcapsule, it can be sufficiently expanded, Moreover, even if it is lower than the maximum expansion temperature of the thermally expandable microcapsule, an expanded body in which the thermally expandable microcapsule is sufficiently expanded can be obtained. For this reason, it is possible to form a foamed resin layer having a relatively large cavity and foamed substantially uniformly.
The thickness of the foamed resin layer is not particularly limited and can be set as appropriate. Although the thickness of a foamed resin layer is not specifically limited, For example, it is 0.5 mm-5 mm, Preferably it is 1 mm-3 mm. If the thickness of the foamed resin layer is too small, the cushioning property of the flooring material is poor, and if it is too large, the sole contacting the flooring material may sink too much.
Also, the expansion ratio of the foamed resin layer is not particularly limited, and is, for example, 1.1 times to 2.5 times in terms of specific gravity, preferably more than 1.1 times and 2.1 times or less, more preferably Is more preferably 1.2 times to 1.7 times. When the expansion ratio is too small, the cushioning property of the flooring material is poor, and when it is too large, the flooring material is easily sag.

<Preparation process of each layer other than the foamed resin layer>
Separately, a protective layer, a decorative layer, a resin layer, a first base material layer, and a second base material layer are prepared. These layers are in the form of a long band having a predetermined width, and preferably a long band having substantially the same width as the foamed resin layer is prepared. In addition, a decorative layer is abbreviate | omitted when using the resin layer to which the designability was provided.
The formation method of a protective layer or a resin layer is not specifically limited, According to the material which forms them, it can select suitably, For example, a calendar method, an extrusion molding method, a solution casting method etc. are mentioned.
In addition, the protective layer, the decorative layer, the resin layer, the first base material layer, and the second base material layer may be independent from each other, or any two or more layers selected from these may be integrally laminated. Good.

<Lamination process>
As shown in FIG. 8, the first base material layer 61, the resin layer 5, the decorative layer 4, and the protective layer 3 are laminated on the upper surface of the foamed resin layer 7, and the second base material layer is placed on the lower surface of the foamed resin layer 7. Each layer is integrated by laminating 62 and passing through a pair of rolls 81 and 82 by heating and pressing.
Specifically, a laminated body in which the protective layer 3, the decorative layer 4, the resin layer 5, the first base material layer 61, the foamed resin layer 7, and the second base material layer 62 are overlapped in order from the upper side is paired with a pair of heating rolls. By passing between 81 and 82 (or heating roll 81 and resin roll 82), the laminate is heated and pressurized, and the layers are joined.
As described above, for example, in the preparation step, in the case where a layer in which two or more arbitrary layers are stacked is prepared, the stack of two or more layers is used in FIG.

Examples of the bonding method of each layer by heat and pressure include a laminating method, a calendering method, and a continuous pressing method. Among them, the method of continuously joining the laminate by heating and pressing with a roll, such as a laminating method and a calendering method, is preferable because many products can be manufactured at one time. In particular, the laminating method can be most suitably applied in the present invention because many laminated bodies can be joined at one time. The heating temperature and pressure of the laminating method are appropriately set according to a known processing method. For example, the heating temperature of the laminate is 140 ° C. to 200 DEG ° C., the pressure between the rolls ^{is 20kgf / cm 2 ~100kgf / cm 2} .
The flooring materials shown in the second to fifth embodiments can be obtained by omitting appropriate layers from the layers shown in FIG. 8 or adding appropriate layers.

<Embossing process>
The embossing process is performed as necessary to form irregularities on the upper surface or the lower surface of the laminate 11. By passing the laminate 11 in which the layers are integrated by passing between the rolls 81 and 82 between the embossing roll 83 and the receiving roll 84, irregularities are formed in the laminate 11.

<Scratch prevention layer forming process>
This step is performed as necessary in order to form the scratch-preventing layer 2 on the upper surface of the protective layer 3.
For example, an ionizing radiation curable monomer or oligomer (formation material of the scratch-preventing layer 2) is applied to the upper surface of the laminate 11 using a roll coater 85 or the like, and ionizing radiation irradiation device 86 is used for ionization. By irradiating with radiation, a flooring in which the scratch-preventing layer 2 is formed on the uppermost surface is obtained.
The obtained long belt-like flooring 1 is wound up on a roll as necessary, and is stored and transported. Further, when the flooring of the present invention is a sheet-like tile, the long strip-like flooring is cut into an appropriate size by punching, cutting, etc., and stacked and stored and transported. To be served.

According to the production method of the present invention, the matrix resin can be foamed at a relatively high magnification, and a foamed resin layer having sufficient strength and appropriate flexibility can be obtained.
The flooring material having such a foamed resin layer is lightweight and has sufficient strength and appropriate flexibility.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples.

[Preparation of thermally expandable microcapsules]
[Production Example 1]
As shown in Table 1, in 600 g of ion-exchanged water, 120 g of sodium chloride, 50 g of colloidal silica having an active silica content of 20% by mass, 3.0 g of adipic acid-diethanolamine condensate and 2% aqueous solution 2 of ethylenediaminetetraacetic acid and 4Na salt 2 0.0 g was added, pH was adjusted to 2.8-3.2, and the aqueous dispersion medium was prepared.
Separately, 155 g of acrylonitrile, 79 g of methacrylonitrile, 15 g of methyl methacrylate (monomer component); 1.0 g of ethylene glycol dimethacrylate (crosslinking agent); 2,2′-azobisisobutyronitrile 1.5 g (polymerization initiator); 16 g of isopentane, 34 g of isooctane, 15 g of isohexanedecane, and 5 g of isohexadecane (encapsulated component) were mixed to prepare an oily mixture. In Table 1, the abbreviations shown in Table 2 are used.
The aqueous dispersion medium and the oily mixture were mixed, and the resulting mixture was dispersed with a homomixer (TK machine manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a suspension. The suspension was transferred to a pressure reactor having a capacity of 1.5 liters, and purged with nitrogen. Then, the initial reaction pressure was 0.5 MPa, and polymerization was performed at a polymerization temperature of 70 ° C. for 20 hours while stirring at 80 rpm. The polymerization solution obtained after the polymerization was filtered and dried to obtain thermally expandable microcapsules (1). The obtained thermally expandable microcapsule (1) had an average particle size of 29 μm, an expansion start temperature Ts of 186 ° C., and a maximum expansion temperature Tmax of 195 ° C. The obtained thermally expandable microcapsule (1) had an internal pressure at 150 ° C. of 0.8 MPa and an internal pressure at 200 ° C. of 1.7 MPa.
The average particle diameter, the expansion start temperature Ts, the maximum expansion temperature Tmax, the internal pressure at 150 ° C., and the internal pressure at 200 ° C. were measured as follows.

[Production Examples 2 to 12]
Thermally expandable microcapsules (2) to (12) were obtained in the same manner as in Production Example 1 except that the aqueous dispersion medium and the oily mixture were changed to those shown in Table 1. Table 1 shows the average particle diameter, expansion start temperature Ts, maximum expansion temperature Tmax, internal pressure at 150 ° C., and internal pressure at 200 ° C. of the thermally expandable microcapsules (2) to (12) obtained.
The thermally expandable microcapsule (10) does not satisfy the condition that its outer shell is a polymer of a polymerizable component containing 45% by mass or more of a nitrile monomer (100/250 = 0.4). The thermally expandable microcapsules (11) and (12) do not satisfy the condition that the internal pressure at 150 ° C. is 0.7 to 1.7 MPa and the internal pressure at 200 ° C. is 1.5 to 3.5 MPa.

[Measurement of expansion start temperature (Ts) and maximum expansion temperature (Tmax)]
As a measuring device, DMA (DMA Q800 type, manufactured by TA instruments) was used. Place 0.5 mg of microspheres into an aluminum cup with a diameter of 6.0 mm (inner diameter 5.65 mm) and a depth of 4.8 mm, and place an aluminum lid (diameter 5.6 mm, 0.1 mm) on top of the microsphere layer. Got ready. The sample height was measured in a state where a force of 0.01 N was applied to the sample with a pressurizer from above. In a state where a force of 0.01 N was applied by the pressurizer, the plate was heated from 20 ° C. to 300 ° C. at a temperature rising rate of 10 ° C./min, and the displacement of the pressurizer in the vertical direction was measured. The displacement start temperature in the positive direction was measured as the expansion start temperature (Ts), and the temperature at which the maximum displacement was shown was measured as the maximum expansion temperature (Tmax).

[Measurement of average particle size]
A laser diffraction particle size distribution analyzer (manufactured by SYMPATEC, HEROS & RODOS) was used. The dispersion pressure of the dry dispersion unit was 5.0 bar, the degree of vacuum was 5.0 mbar, measured by a dry measurement method, and the D50 value was defined as the average particle size.

[Calculation method of internal pressure]
The internal pressure at 150 ° C. and 200 ° C. of the inclusion component of the thermally expandable microcapsule is calculated by calculating the mole fraction of each hydrocarbon constituting the inclusion component from the blending amount of each hydrocarbon constituting the inclusion component. The vapor pressure at 150 ° C. and 200 ° C. of each hydrocarbon to be multiplied by the calculated mole fraction of each hydrocarbon, and the multiplied values were summed to calculate the internal pressure at 150 ° C. and 200 ° C. of the inclusion component.
Isobutane: vapor pressure at 150 ° C. of 4.1 MPa, vapor pressure at 200 ° C. of 7.4 MPa, molecular weight 58.
Isopentane: vapor pressure at 150 ° C 1.8 MPa, vapor pressure at 200 ° C 3.6 MPa, molecular weight 72.
Isohexane: vapor pressure 0.89 MPa at 150 ° C., vapor pressure 2.0 MPa at 200 ° C., molecular weight 86.
Isooctane: vapor pressure at 150 ° C. of 0.35 MPa, vapor pressure at 200 ° C. of 0.89 MPa, molecular weight 114.
Isododecane: molecular weight 170
Isohexadecane: molecular weight 226
Since the vapor pressures at 150 ° C. and 200 ° C. of isododecane and isohexadecane are very low, the vapor pressure of the encapsulated component of the thermally expandable microcapsule was calculated with the vapor pressure of isododecane and isohexadecane being substantially 0 MPa.

[Example 1]
In the proportions shown in Table 3, 23 parts by mass of vinyl chloride resin (paste vinyl chloride manufactured by Shin Daiichi PVC Co., Ltd., degree of polymerization 1050), 58.5 parts by mass of inorganic filler (Nitto Flour & Chemical Co., Ltd.) Heavy calcium carbonate), 16.5 parts by weight of plasticizer (dioctyl phthalate manufactured by Shin Nippon Kagaku Co., Ltd.), and stabilizer (Ca—Zn stabilizer manufactured by Sakai Chemical Industry Co., Ltd.) (Trade name “SMG-500” manufactured by Kawata Co., Ltd.) and kneaded for about 15 minutes at a rotating speed of the stirring blade of 1000 rpm. When the material temperature at this time was measured, it was about 150 degreeC. The melting temperature of the vinyl chloride resin is about 135 ° C.
Next, 0.7 parts by mass of the thermally expandable microcapsule (1) obtained in Production Example 1 was added, and the mixture was further kneaded for about 1 minute while maintaining the rotational speed of the stirring blade, whereby 350 kg of powder was obtained. A resin composition was obtained. The material temperature after adding the thermally expandable microcapsule (1) also remained at about 150 ° C.
Next, this was stirred while cooling, and the crude heat was taken to 60 ° C. The obtained powder was passed through a sieve having a mesh size of 12 mesh, and the material passed through the sieve was used as a foamed resin layer forming material.
This foamed resin layer forming material was put into a hopper of an extrusion molding machine and extruded at a temperature of 180 ° C. to form a foamed resin layer having a thickness of 1.8 mm, a width of 1950 mm, and a length of 10 m.

[Examples 2 to 9, Comparative Examples 1 to 3]
Examples 2 to 9 and Comparative Examples 1 to 3 are the same as Example 1 except that instead of the thermally expandable microcapsules (1), the thermally expandable microcapsules (2) to (12) are used, respectively. Thus, each of the foamed resin layers was formed. However, in Example 8, the material temperature when kneading for about 15 minutes was about 145 ° C.

[State during mixing]
About Example 1 thru | or 9 and Comparative Examples 1 thru | or 3, the state of the capsule at the time of mixing a thermally expansible microcapsule was confirmed. In the confirmation method, the powdery resin composition (formation material for the foamed resin layer) obtained by mixing is placed in a methanol solution with a purity of 99%, and the suspended matter is confirmed. The specific gravity of the unexpanded microcapsule is about 1, and the specific gravity of the expanded microcapsule is about 0.02. For this reason, when the said floating substance arises, it can be judged that the floating substance is the thermally expanded microcapsule which expanded. The results are shown in Table 3.
In the mixed state of Table 3, ○ indicates that no suspended solids were observed, that is, most of the thermally expandable microcapsules were present in the resin composition without expansion, and Δ represents a small amount of floating The product was observed, that is, a small amount of thermally expandable microcapsules was expanded, but the remainder was present in the resin composition without expanding, x was a large amount of suspended matter was observed, That is, most of the thermally expandable microcapsules were expanded.

[Processability during molding]
For Examples 1 to 9 and Comparative Examples 1 to 3, when the foamed resin layer was molded, the ease of molding into a sheet shape was evaluated. The results are shown in Table 3.
○ in the processability at the time of molding in Table 3 indicates that foaming is performed at a foaming ratio of 1.4 times or more, and the microcapsule is hardly destroyed during extrusion molding, and the foamed resin layer can be efficiently manufactured. , Δ indicates that foaming was performed at a foaming ratio of 1.1 to 1.4 times, and some microcapsules were broken, and × was a foaming ratio of less than 1.1 times. This indicates that the capsule is broken or the microcapsule does not foam and a foamed resin layer having a target foaming ratio cannot be manufactured.

[Foaming ratio]
The expansion ratio of the foamed resin layers obtained in Examples 1 to 9 and Comparative Examples 1 to 3 was calculated in terms of specific gravity. Foaming ratio in terms of specific gravity = specific gravity of the foamed resin layer that has been re-kneaded to crush the hollow portion into a sheet, divided by the specific gravity of the foamed resin layer. The results are shown in Table 3.

[Example 10]
In the proportions shown in Table 4, vinyl chloride resin (suspension vinyl chloride manufactured by Shin Daiichi Vinyl Co., Ltd., polymerization degree 1050), inorganic filler (heavy calcium carbonate of Nitto Flour & Chemical Co., Ltd.), plasticizer (new Dictyl phthalate manufactured by Nihon Kagaku Co., Ltd.) and stabilizer (Ca-Zn stabilizer manufactured by Sakai Chemical Industry Co., Ltd.) are introduced into a super mixer (trade name "SMG-500" manufactured by Kawata Co., Ltd.) The mixture was kneaded for about 15 minutes at a stirring blade speed of 1000 rpm. When the material temperature at this time was measured, it was about 150 degreeC. The melting temperature of the vinyl chloride resin is about 135 ° C.
Next, 0.7 parts by mass of the thermally expandable microcapsule (1) obtained in Production Example 1 was added, and the mixture was further kneaded for about 1 minute while maintaining the rotational speed of the stirring blade, whereby 350 kg of powder was obtained. A resin composition was obtained. The material temperature after adding the thermally expandable microcapsule (1) also remained at about 150 ° C.
Next, this was stirred while cooling, and the crude heat was taken to 60 ° C. The obtained powder was passed through a sieve having a mesh size of 12 mesh, and the material passed through the sieve was used as a foamed resin layer forming material.
This foamed resin layer forming material was put into a hopper of an extrusion molding machine and extruded at a temperature of 180 ° C. to form a foamed resin layer having a thickness of 1.8 mm, a width of 1950 mm, and a length of 10 m.

On the upper surface of this foamed resin layer, as a base material layer, a glass nonwoven fabric (trade name “Grabest” manufactured by Olivest Co., Ltd .. Glass fiber thickness: diameter of about 18 μm, glass fiber length: about 13 mm, basis weight of glass fiber : 37 g / m ² ) and a paste vinyl chloride resin (manufactured by Kaneka Co., Ltd., polymerization degree: 1150, K value: 69) was applied thereon to form a resin layer having a thickness of about 0.3 mm. . On the resin layer, a decorative paper (trade name “Hiroshima Kasei Co., Ltd., trade name“ Center Film ”, thickness 0.15 mm.) Is laminated as a decorative layer. A “clear film” (thickness: 0.37 mm) was stacked to form a laminate.
In a state where the laminate is heated to 150 ° C. with a preheater, the laminate is passed between upper and lower laminate rolls each having a temperature of 50 ° C., thereby forming a long strip having a thickness of about 2.5 mm, a width of 1950 mm, and a length of 10 m. A flooring was prepared. In addition, the conveyance speed of the laminated body was about 10 m / min, and the pressure applied to the laminated body was 40 kgf / cm ² .

[Examples 11 to 18]
A flooring was produced in the same manner as in Example 1 except that the blending amount of each material was changed to the ratio shown in Table 4. In addition, the column of the composition of Table 4 is a mass part display.

[Example 19]
Instead of the vinyl chloride resin of Example 1, a vinyl chloride resin having a polymerization degree of 800 (suspension vinyl chloride manufactured by Shin Daiichi Vinyl Co., Ltd., melting temperature of about 135 ° C.) and the blending of each material A flooring was produced in the same manner as in Example 1 except that the amount was changed to the ratio shown in Table 4.

[Example 20]
In place of the vinyl chloride resin of Example 1, a vinyl chloride resin having a polymerization degree of 1400 (suspension vinyl chloride manufactured by Kaneka Corporation. Melting temperature is about 145 ° C.) and the blending amount of each material are shown. A flooring was produced in the same manner as in Example 1 except that the ratio was changed to the ratio shown in FIG.

[Example 21]
Instead of the vinyl chloride resin of Example 1, a vinyl chloride resin having a polymerization degree of 650 (suspension vinyl chloride manufactured by Kaneka Corporation, melting temperature of about 125 ° C.) and the blending amount of each material are shown. A flooring was produced in the same manner as in Example 1 except that the ratio was changed to the ratio shown in FIG.

[Example 22]
Instead of the vinyl chloride resin of Example 1, a vinyl chloride-vinyl acetate copolymer (manufactured by Kaneka Corporation. Vinyl chloride: vinyl acetate = 95: 5, polymerization degree 780, melting temperature about 125 ° C.) was used. And the flooring was produced like Example 1 except having changed the compounding quantity of each material into the ratio shown in Table 4.

[Example 23]
Example 1 except that instead of calcium carbonate of Example 1 clay (made by Daiseng Sangyo Co., Ltd.) was used as a filler and the blending amount of each material was changed to the ratio shown in Table 4. In the same manner, a flooring was produced.

[Example 24]
Example 1 and Example 1 except that talc (manufactured by Nippon Talc Co., Ltd.) was used as a filler instead of the calcium carbonate of Example 1 and the blending amount of each material was changed to the ratio shown in Table 4. Similarly, a flooring was produced.

[Example 25]
Example except that wollastonite (manufactured by Maruo Calcium Co., Ltd.) was used as a filler in place of the calcium carbonate of Example 1, and the blending amounts of the respective materials were changed to the ratios shown in Table 4. In the same manner as in Example 1, a flooring was produced.

[Example 26]
Implemented except that in place of dioctyl phthalate of Example 1, dioctyl adipate (manufactured by J-Plus Co., Ltd.) was used as a plasticizer, and the blending amounts of each material were changed to the ratios shown in Table 4. A flooring was produced in the same manner as in Example 1.

[Example 27]
Implemented except for using diisononyl phthalate (manufactured by J-Plus Co., Ltd.) as a plasticizer instead of dioctyl phthalate of Example 1 and changing the blending amounts of each material to the ratios shown in Table 4. A flooring was produced in the same manner as in Example 1.

[Foaming ratio]
The expansion ratio of the foamed resin layers obtained in Examples 10 to 27 was calculated in terms of specific gravity. The results are shown in Table 4.

[Cavity size]
The size of the cavity (bubble) of the foamed resin layer obtained in Examples 10 to 27 was measured. The results are shown in Table 4.
The size of the cavity was measured using a microscope measuring machine. Specifically, using a 3D digital fine scope “VC7700” manufactured by OMRON Corporation, the cross section of the foamed resin layer was enlarged 50 times, and 10 cavities were arbitrarily selected from the cross section. The vertical and horizontal internal dimensions were measured respectively. The size of the hollow portion was an average value of 20 measured values in total.

[Bending crack test]
In order to confirm the flexibility and strength of the foamed resin layers obtained in Examples 10 to 27, a bending crack test was performed.
In the bending crack test, the foamed resin layer is cut into a length × width = 5 cm × 30 cm to obtain a sample, and the sample is wound around a cylinder with a diameter of 6 mm and a cylinder with a diameter of 4 mm in a 5 ° C. environment, and the sample is cracked. Confirmed whether or not. The results are shown in Table 4.
◯ of the test results were not cracked even when wound on all cylinders, and △ was cracked when wound on a cylinder with a diameter of 4 mm, but cracked when wound on a cylinder with a diameter of 6 mm, X represents that a crack occurred when wound around a cylinder having a diameter of 6 mm.

DESCRIPTION OF SYMBOLS 1 Floor material 7 Foamed resin layer 7a Hollow part 71 Matrix resin 73 Hollow wall part

Claims (4)

Thermal expansibility composed of at least one of vinyl chloride resin and vinyl acetate resin, an outer shell made of nitrile thermoplastic resin, and an inner shell component encapsulated in the outer shell and vaporized by heating. A step of obtaining a foamed resin layer by molding a resin composition containing microcapsules while heating to a temperature of 150 to 200 ° C.,
The nitrile thermoplastic resin is a polymer of a polymerizable component containing 45% by mass or more of a nitrile monomer,
The method for producing a flooring material, wherein the thermally expandable microcapsule has an internal pressure at 150 ° C of 0.7 to 1.7 MPa and an internal pressure at 200 ° C of 1.5 to 3.5 MPa.   The method for producing a flooring according to claim 1, wherein the resin composition further contains an inorganic filler, and the amount of the inorganic filler with respect to the entire resin composition is more than 0 and 68% by mass or less.   The manufacturing method of the flooring material of Claim 1 or 2 whose quantity of the said thermally expansible microcapsule with respect to the said whole resin composition is 0.1 mass%-3 mass%. A foamed resin having a matrix resin containing at least one of a vinyl chloride resin and a vinyl acetate resin, a plurality of hollow portions scattered in the matrix resin, and a hollow wall portion forming the hollow portion Has a layer,
The hollow wall portion is composed of an outer shell of a thermally expandable microcapsule having an internal pressure at 150 ° C. of 0.7 to 1.7 MPa and an internal pressure at 200 ° C. of 1.5 to 3.5 MPa, A flooring in which the outer shell of the expanded body is formed from a polymer of a polymerizable component containing 45% by mass or more of a nitrile monomer.

Images