JP7562982B2 - Cosmetic materials - Google Patents

Description

This invention relates to a wide, lightweight decorative material that has excellent strength and places little strain on the construction.

Conventionally, decorative sheets attached to wood-based substrates such as plywood and fiberboard have been widely used for architectural interior materials, flooring materials, fittings, surface materials for home appliances, etc. However, these decorative materials have problems with physical properties such as warping, insect damage, and corrosion caused by the moisture absorption and release of the wood-based substrate, and the substrate is heavy due to being made of wood, which increases the burden of construction work.
As a countermeasure to the above problems, many resin moldings containing a thermoplastic resin and a filler have been developed.
One of the molding methods is the Cerca process (Patent Documents 1 and 2). The Cerca process is a molding method in which a special die is used to solidify the surface layer to form a low foam layer, and at the same time, a foam layer is formed in the core.

Patent No. 4206802 Patent No. 3932883

However, since the above-mentioned Celca process is a profile extrusion molding process, the dimension in the width direction is shorter than the flow direction, and therefore different linear expansion properties are required in the flow direction and the width direction.
For this reason, fibrous wood powder, which has a high effect of suppressing dimensional change in the flow direction, has often been used as a filler. However, it is difficult to make resin moldings with added fibrous fillers wide, which increases the workload during construction and poses economic challenges.
By adding a scaly filler, it is possible to suppress linear expansion in both the machine direction and the width direction, and this effect can be further enhanced by increasing the filler mixing ratio. However, there are problems such as a decrease in the strength of the base material and deterioration of foaming properties, particularly when the filler ratio is 50% or more.

On the other hand, narrow-width molded bodies are a heavy burden to install and have economic problems, so there is a demand for the development of wide-width molded bodies. With fibrous fillers such as wood powder, it is difficult to make them wider because there is a difference in linear expansion between the flow direction and the width direction. As a solution, the use of a high-aspect-ratio scale-like filler can stabilize the thermal expansion and contraction in the flow direction and width direction, but on the other hand, there are issues with the deterioration of foaming properties due to a decrease in viscosity and the decrease in strength due to the deterioration of the filler's dispersibility.
An object of one aspect of the present invention is to provide a wide, lightweight decorative material that is excellent in strength and imposes little strain on the user during application.

In order to achieve the above-mentioned object, a decorative material according to one embodiment of the present invention is a decorative material consisting of a substrate and a decorative sheet laminated to the substrate, wherein the substrate contains a thermoplastic resin and a scaly filler, has a Cerca structure, has a linear expansion coefficient of 6.0 x ^10-5 or less in at least the width direction out of the machine direction and the width direction, contains 50 to 70% by weight of the filler, and the substrate has a bending strength of 30 MPa or more and a bending elasticity in the range of 2000 to 9000 MPa.
A decorative material according to one aspect of the present invention is characterized in that the substrate has a width of 500 mm or more and a length of 500 mm or more.
A decorative material according to one embodiment of the present invention is characterized in that the filler has an average aspect ratio of 10 or more, calculated from the average diameter/thickness of the plate surface.

A decorative material according to one embodiment of the present invention is characterized in that a substrate contains an olefin-based elastomer having a melt flow rate (MFR) of 300 or more in an amount of 10 to 30% by weight based on the weight of the substrate excluding the filler.
A decorative material according to one embodiment of the present invention includes an olefin having strain hardening properties in a substrate, the olefin being contained in an amount of 3 to 10% by weight based on the weight of the substrate excluding the filler.
A decorative material according to one embodiment of the present invention comprises a base material containing an olefin-based elastomer having a melt flow rate (MFR) of 300 or more as a first additive in an amount of 10 to 30% by weight based on the weight of the base material excluding the filler, and an olefin having strain hardening properties as a second additive in an amount of 3 to 10% by weight based on the weight of the base material excluding the filler, with the ratio of the first additive to the second additive being within the range of 5:1 to 1:1.

According to one aspect of the present invention, it is possible to provide a wide, lightweight decorative material that has excellent strength and places little strain on the user during application.

FIG. 1 is a cross-sectional view of a decorative material according to an embodiment of the present invention.

(Decorative material 10)
In FIG. 1, 10 is a decorative material.
The decorative material 10 is broadly composed of a substrate 20 and a decorative sheet 30 laminated to the substrate 20. Located between the substrate 20 and the decorative sheet 30 is an adhesive layer 40 that bonds the substrate 20 and the decorative sheet 30 together.
The thickness ratio of each layer of the decorative material 10 is not limited to that shown in FIG.

(Substrate 20)
The substrate 20 contains a thermoplastic resin and a scaly filler, and has a cell structure.
As shown in FIG. 1, the substrate 20 is roughly composed of a foam layer 22 and surface layers 21, 21 located on both sides of the foam layer 22, respectively.
Examples of the thermoplastic resin that can be used for the substrate 20 include polypropylene, polyethylene, polyvinyl chloride, ABS, polystyrene, polyester, polyamide, polyolefin, ethylene-propylene-diene rubber, ethylene vinyl acetate, and silicone rubber. However, polypropylene is preferred in terms of the mechanical strength and water resistance of the wood substrate.

(Decorative sheet 30)
The decorative sheet 30 is a sheet made of the same material as the base material 20, such as polyolefin or vinyl chloride resin, and is provided with a design such as wood grain or an abstract pattern.
1, the decorative sheet 30 is broadly composed of a design layer 31, a laminate 32, and a top coat 33. The design layer 31 is a sheet base material or a sheet base material on which a design is applied by printing. The sheet base material may be colored.
The thermoplastic resin for the decorative sheet 30 is not particularly limited, but in consideration of the recyclability of the decorative material 10, it is desirable to use a sheet of the same material as the base material 20 with a design such as wood grain or an abstract pattern.

(Adhesive layer 40)
The adhesive layer 40 bonds the surface layer 21 of the substrate 20 and the design layer 31 of the decorative sheet 30 .
The adhesive material used for the adhesive layer 40 is not particularly limited, but a two-liquid urethane resin adhesive or the like can be used.
The adhesive layer 40 may be omitted if sufficient adhesive strength is obtained between the surface layer 21 of the substrate 20 and the design layer 31 of the decorative sheet 30 .

(Selkie structure)
A Cerca structure is a structure obtained by the Cerca process or an equivalent structure.
The Cerca process (Cerca method) is a foaming extrusion molding method in which an extrusion die having outlet dimensions approximately the same as or slightly smaller than the inlet dimensions of a cooling sizing die is used, and a foamable resin composition is extruded from the extrusion die with the outlet of the extrusion die and the inlet of the cooling sizing die being brought into close contact with each other, thereby introducing the foamable resin composition into the cooling sizing die in a state in which foaming has hardly progressed, and foaming occurs mainly inside the cooling sizing die.
The Celca structure is not limited to structures produced by the above-mentioned methods, and is characterized in that at least a portion of the surface is non-foamed or low-foamed, the core is highly foamed, the non-foamed or low-foamed surface and the core are made of thermoplastic resin of the same composition, and the core and the surface have a continuous structure.
In this embodiment, the Cerca structure is adopted because the resin molded body formed by the Cerca process has excellent workability for cutting and nailing, and because a surface layer is formed, the surface is smooth and highly scratch-resistant.In addition, because it is a foam, it is lightweight, requires little construction effort, and has high thermal insulation properties.

(Characteristics of the substrate 20)
The substrate 20 is required to be a wide and lightweight flooring material that has excellent mechanical strength such as bending elasticity and bending strength, and that places little strain on construction. For this reason, the substrate 20 is desirably 500 mm or more in width and 500 mm or more in length. If the substrate 20 is less than 500 mm in width or less than 500 mm in length, the burden on construction increases.
The linear expansion coefficient of the substrate 20 is desirably 6.0×10 ⁻⁵ or less at least in the transverse direction (TD) out of the machine direction (MD) and the transverse direction (TD).
This allows the substrate 20 to be made wider.
The linear expansion coefficient may be 6.0×10 ⁻⁵ or less in both the machine direction (MD) and the transverse direction (TD).

(Material composition of the substrate 20)
The material composition of the substrate 20 is required to contain 50 to 70% by weight of a scaly filler.
This is because if the filler is less than 50%, the linear expansion coefficient of the resin affects the resin and the dimensional stability decreases, whereas if the filler is more than 70%, the filler is poorly dispersed, which reduces the bending strength and the melt viscosity, resulting in poor foaming properties.
In this embodiment, the material composition of the base material 20 contains 50 to 70 weight percent of a scaly filler, thereby providing a decorative material 10 with high dimensional stability without compromising foamability and strength.
As the flaky filler, it is preferable to use talc, mica, clay, bentonite, silica, hexagonal boron nitride, etc.

(Aspect ratio of scale-like filler)
The aspect ratio of the scaly filler is desirably 10 or more, preferably 30 or more. The aspect ratio is a value calculated from the average diameter/thickness of the plate surface of the scaly filler. To suppress linear expansion, it is preferable to use a filler with a high aspect ratio.

(Additives for Substrate 20)
The base material 20 contains a thermoplastic resin and a scaly filler, as well as one or more types of additives.
In this embodiment, the following additives are added.
The additives are not limited to the following (1) and (2).
(1) First additive (hereinafter also referred to as “additive 1”)
Additive 1 contains an olefin-based elastomer having a melt flow rate (MFR) of 300 or more, preferably 1000 or more, in an amount of 10 to 30% by weight based on the weight of the base material excluding the scaly additive.
Here, the melt flow rate (MFR) is one of the methods for evaluating the fluidity of a resin.

The melt flow rate is measured by loading resin test material (pellets) into a test device called a melt flow indexer, heating it to melt a specified weight of resin, and measuring the amount of resin that flows out, and the test method is regulated by JIS and ISO. The higher the melt flow rate, the better the resin is evaluated to have fluidity, and the lower the melt flow rate, the worse the flow.
When the filler content exceeds 50%, the bending strength decreases, so the dispersibility of the filler in the resin becomes important. To improve the dispersibility, it is desirable to use a material with a high MFR as an additive.
(2) Second additive (hereinafter also referred to as “additive 2”)
Additive 2 contains an olefin having strain hardening properties in an amount of 3 to 10% by weight based on the weight of the base material excluding the filler.
As the blending ratio of the scaly filler increases, the melt viscosity decreases and the foaming property of the base material 20 deteriorates, so it is advisable to add a resin having strain hardening properties.

(Ratio of Additive 1 to Additive 2)
The ratio of additive 1 to additive 2 is preferably 5:1 to 1:1.
This is because a high ratio of additive 1 deteriorates the foaming property, whereas a high ratio of additive 2 deteriorates the dispersibility due to an increase in melt viscosity.

Other Properties of Substrate 20
Other characteristics of the substrate 20 include the following:
(1) Flexural Modulus of Elasticity The flexural modulus of the substrate 20 is 2000 to 9000 MPa.
If the flexural modulus is less than 2000 MPa, the rigidity and surface hardness are insufficient, and scratch resistance and indentation resistance are deteriorated.If the flexural modulus exceeds 9000 MPa, the substrate becomes hard, resulting in poor walking feel and reduced flexural strength.
(2) Bending Strength The bending strength of the substrate 20 is 30 MPa or more.
(3) Foaming Method The foaming method for the substrate 20 is preferably chemical foaming, physical foaming, supercritical foaming, or the like.
(4) Foam Structure The foam structure of the substrate 20 is preferably formed by closed cell foaming, open cell foaming, or the like.

(Features of this embodiment)
The decorative material 10 according to this embodiment has an object to provide a wide, lightweight flooring material that has excellent mechanical strength such as bending elasticity and bending strength, and that places a small burden on construction.
In order to increase the width of the substrate 20, it is necessary to increase the suppression of linear expansion in the width direction. In order to increase the suppression of linear expansion in the width direction, it is necessary to pack a large amount of filler (flake-like filler) having a high aspect ratio.
On the other hand, the substrate 20 becomes heavy, and therefore needs to be foamed. As a solution to this problem, it is effective to add a high melt tension resin (olefin having strain hardening properties) to impart foaming properties.
In addition, it is necessary to add an interfacial modifier because the strength of the substrate 20 decreases. As a solution, for example, it is effective to add an olefin-based elastomer to improve dispersibility and suppress the decrease in bending elasticity and bending strength.

With reference to this embodiment, the decorative materials of Examples 1 to 10 and Comparative Examples 1 to 9 will be described below.
(Example 1: Base)
In Example 1, the following materials were mixed and pelletized in a twin-screw kneader. The pellets were expanded by 1.4 times by chemical foaming using a sodium bicarbonate-citric acid foaming agent, and molded into a rectangular parallelepiped shape with a thickness of 5 mm by the Celca process.
(1) Thermoplastic resin: Polypropylene 30 parts by weight (wt%)
(2) Scaly filler: Filler (mica) 60 parts by weight (wt%)
The aspect ratio is 80.
(3) Additive 1: Olefin-based elastomer (hereinafter also referred to as "elastomer")
7 parts by weight (wt%)
(4) Additive 2: Branched olefin 2 parts by weight (wt%)
In this case, the elastomer/branched olefin ratio is 3.5.
(5) Others: Maleic acid modified polypropylene 1 part by weight (wt%)

(Example 2: Low aspect ratio)
Example 2 is the same as Example 1, except that the aspect ratio of the filler in Example 1 is reduced from "80" to "10".

Example 3: Low Filler
Examples 3 to 10 are the same as Example 1 except that the material composition in Example 1 is changed.
First, in Example 3, the amount of the filler in Example 1 was reduced from "60 parts by weight" to "50 parts by weight."
In this case, the amount of elastomer in Example 1 was increased from "7 parts by weight" to "9 parts by weight", and the amount of branched olefin was increased from "2 parts by weight" to "2.5 parts by weight". As a result, the "elastomer/branched olefin" ratio increased from "3.5" to "3.6".

Example 4: Filler Height
In Example 4, contrary to Example 3, the amount of the filler in Example 1 was increased from "60 parts by weight" to "70 parts by weight."
In this case, the amount of the elastomer in Example 1 was reduced from 7 parts by weight to 5 parts by weight, and the amount of the branched olefin was reduced from 2 parts by weight to 1.5 parts by weight. As a result, the "elastomer/branched olefin" ratio was reduced from 3.5 to 3.3.

(Example 5: Elastomer Low)
In Example 5, the amount of the elastomer blended in Example 1 was reduced from "7 parts by weight" to "4 parts by weight."
At this time, the blending amount of the branched olefin in Example 1 was increased from "2 parts by weight" to "2.5 parts by weight", and as a result, the "elastomer/branched olefin" was decreased from "3.5" to "1.6".
(Example 6: High Elastomer)
In Example 6, contrary to Example 5, the blending amount of the elastomer in Example 1 was increased from "7 parts by weight" to "12 parts by weight."
At this time, the blending amount of the branched olefin in Example 1 was increased from "2 parts by weight" to "2.5 parts by weight", and as a result, the "elastomer/branched olefin" increased from "3.5" to "4.8".

Example 7: Low branched olefins
In Example 7, the amount of the branched olefin in Example 1 was reduced from "2 parts by weight" to "1.2 parts by weight."
At this time, the amount of the elastomer in Example 1 was reduced from "7 parts by weight" to "5 parts by weight", and as a result, the "elastomer/branched olefin" increased from "3.5" to "4.2".
(Example 8: High branched olefins)
In Example 8, contrary to Example 7, the blending amount of the branched olefin in Example 1 was increased from "2 parts by weight" to "4 parts by weight."
At this time, the blending amount of the elastomer in Example 1 was reduced from "7 parts by weight" to "5 parts by weight", and as a result, the "elastomer/branched olefin" was reduced from "3.5" to "1.3".

Example 9: Elastomer/Low Branched Olefin
Example 9 reduced the "Elastomer/branched olefins" in Example 1 from "3.5" to "1.0".
At this time, the blending amount of the elastomer in Example 1 was decreased from "7 parts by weight" to "4 parts by weight", and the blending amount of the branched olefin was increased from "2 parts by weight" to "4 parts by weight".
Example 10: Elastomer/High Branched Olefin
In contrast to Example 9, Example 10 increased the "elastomer/branched olefin" in Example 1 from "3.5" to "5.0".
At this time, the blending amount of the elastomer in Example 1 was increased from "7 parts by weight" to "8 parts by weight", and the blending amount of the branched olefin was decreased from "2 parts by weight" to "1.6 parts by weight".

(Comparative Example 1: Low aspect ratio)
Comparative Example 1 is the same as Example 1, except that the aspect ratio of the filler in Example 1 was reduced from "80" to "9".
(Comparative Example 2: Low Filler)
Comparative Examples 2 to 9 are the same as Comparative Example 1 except that the material composition in Comparative Example 1 was changed.
The changes in other parameters when the parameter is changed are as shown in Table 1 below, and the explanation will be omitted.
First, in Comparative Example 2, the amount of the filler in Comparative Example 1 was reduced from "60 parts by weight" to "40 parts by weight."
(Comparative Example 3: High Filler)
In Comparative Example 3, contrary to Comparative Example 2, the blending amount of the filler in Comparative Example 1 was increased from "60 parts by weight" to "80 parts by weight."

(Comparative Example 4: Low Elastomer)
In Comparative Example 4, the amount of the elastomer in Comparative Example 1 was reduced from "7 parts by weight" to "3 parts by weight."
(Comparative Example 5: High Elastomer)
In Comparative Example 5, unlike Comparative Example 4, the blending amount of the elastomer in Comparative Example 1 was increased from "7 parts by weight" to "13 parts by weight."
(Comparative Example 6: Low Branched Olefins)
In Comparative Example 6, the amount of the branched olefin in Comparative Example 1 was reduced from "2 parts by weight" to "1 part by weight."
(Comparative Example 7: High Branched Olefins)
In Comparative Example 7, contrary to Comparative Example 6, the blending amount of the branched olefin in Comparative Example 1 was increased from "2 parts by weight" to "4 parts by weight."
(Comparative Example 8: Elastomer/Low Branched Olefin)
In Comparative Example 8, the "Elastomer/branched olefin" in Comparative Example 1 was reduced from "3.5" to "0.8".
(Comparative Example 9: Elastomer/High Branched Olefin)
In contrast to Comparative Example 8, Comparative Example 9 increased the "elastomer/branched olefin" in Comparative Example 1 from "3.5" to "5.2."

(Evaluation Method)
The above-mentioned Examples 1 to 10 and Comparative Examples 1 to 9 were evaluated for four items: (1) bending strength, (2) bending elasticity, (3) MD (machine direction) linear expansion coefficient, and (4) TD (transverse direction) linear expansion coefficient.
(Thermal expansion measurement)
The linear expansion coefficient was evaluated for the above-mentioned Examples 1 to 10 and Comparative Examples 1 to 9. The linear expansion coefficient was evaluated by calculating the linear expansion coefficient in the temperature range of 10° C. to 70° C. using a thermomechanical analyzer TMA (product name).

(Criteria and Results of Judgment)
As described in the embodiment, a bending strength of 30 MPa or more was considered to be acceptable, and a bending strength of less than 30 MPa was considered to be unacceptable.
As explained in the embodiment, the flexural modulus was considered to be acceptable in the range of 2000 to 9000 MPa, and was considered to be unacceptable in the cases of less than 2000 MPa and more than 9000 MPa.
The linear expansion coefficient was divided into MD (machine direction) and TD (transverse direction), and a value of 6.0×10 ⁻⁵ or less at least in the transverse direction was considered to be acceptable, and a value exceeding 6.0×10 ⁻⁵ was considered to be unacceptable.
The evaluation results are shown in Table 1.

(About bending strength)
As for the bending strength, as shown in Table 1, all of the bending strengths of Examples 1 to 10 were 30 MPa or more, which was acceptable.
In contrast, among Comparative Examples 1 to 9, three of Comparative Examples 1, 2 and 9 had bending strengths of 30 MPa or more and passed the test.
However, the remaining Comparative Examples 3 to 8 had bending strengths of less than 30 MPa, failing the test and showing insufficient bending strength. In Comparative Example 3, it can be assumed that the filler content was too high at "80 parts by weight". In Comparative Example 4, it can be assumed that the elastomer content was too low at "3 parts by weight". In Comparative Example 6, it can be assumed that the branched olefin content was too low at "1 part by weight". In Comparative Example 7, it can be assumed that the elastomer content was too low at "8 parts by weight". In Comparative Example 8, it can be assumed that the "elastomer/branched olefin" was too low at "0.8".

(About bending elasticity)
Concerning the bending elasticity, all of the bending elasticities of Examples 1 to 10 were within the range of 2000 to 9000 MPa and passed the test.
In contrast, for Comparative Examples 1 to 9, the bending elasticity of Comparative Example 1, Comparative Example 2, Comparative Example 4, and Comparative Examples 6 to 8 was within the range of 2000 to 9000 MPa, and therefore passed the test.
However, the remaining Comparative Examples 3, 5, and 9 were unsuccessful because they were less than 2000 MPa or more than 9000 MPa. It can be assumed that the filler content in Comparative Example 3 was too high at "80 parts by weight." It can be assumed that the "elastomer/branched olefin" in Comparative Example 9 was too high at "5.2."

(Linear expansion coefficient in MD and TD)
Concerning the linear expansion coefficient in the MD and TD, all of the linear expansion coefficients of Examples 1 to 10 were 6.0×10 ⁻⁵ or less, which was acceptable.
In contrast, among Comparative Examples 1 to 9, the linear expansion coefficients of Comparative Examples 3 to 9 were 6.0×10 ⁻⁵ or less, and therefore passed the test.
However, the remaining Comparative Examples 1 and 2 exceeded 6.0× ^10-5 and failed. In Comparative Example 1, it can be assumed that the aspect ratio of the filler was too low at "9". In Comparative Example 2, it can be assumed that the blending amount of the filler was too low at "40 parts by weight".

(comprehensive evaluation)
Among Examples 1 to 10, Example 6 had an elastomer blending ratio of "12 parts by weight," which was within the range of 10 to 30% by weight that was preferred in the embodiment described above, and as a result, the linear expansion coefficient was 6.0 x ^10-5 or less, which was a low value.
In addition, among Examples 1 to 10, Examples 8 and 6 both had a branched olefin blending ratio of "4 parts by weight," which is within the range of 3 to 10% by weight that is preferred in the embodiment, and as a result, the linear expansion coefficient was 6.0 x ^10-5 or less, which was a low value.
In summary, only Examples 1 to 10 satisfied all four of the conditions (1) to (4).

REFERENCE SIGNS LIST 10 decorative material 20 substrate 21 surface layer 22 foam layer 30 decorative sheet 31 design layer 32 laminate 33 top coat 40 adhesive layer

Claims (6)

A decorative material comprising a substrate and a decorative sheet laminated on the substrate,
The substrate includes a thermoplastic resin and a scaly filler and has a cell structure;
The linear expansion coefficient is 6.0 × 10 ^or less in at least the width direction among the machine direction and the width direction,
The filler is contained in an amount of 50 to 70% by weight,
The substrate has a bending strength of 30 MPa or more and a bending elasticity in the range of 2000 to 9000 MPa,
The base material contains an olefin-based elastomer having a melt flow rate (MFR) of 300 or more as a first additive, in an amount of 10 to 18 % by weight based on the weight of the base material excluding the filler,
a branched olefin as a second additive, the second additive being present in an amount of 3 to 6.3 wt. % based on the weight of the base material excluding the filler;
the ratio of the first additive to the second additive is in the range of 5:1 to 3.3:1, alternatively in the range of 1.6:1 to 1:1 ;
A decorative material, characterized in that the thermoplastic resin of the substrate is ABS resin, ethylene propylene diene rubber, ethylene vinyl acetate, or silicone rubber. The decorative material according to claim 1, characterized in that the substrate has a width of 500 mm or more and a length of 500 mm or more. The decorative material according to claim 1 or 2, characterized in that the filler has an average aspect ratio calculated from the average diameter/thickness of the plate surface of 10 or more. The decorative material according to any one of claims 1 to 3, characterized in that the substrate has a bending strength of 42 MPa or more. The decorative material according to claim 4, characterized in that the substrate has a bending strength of 52 MPa or less. The decorative material according to any one of claims 1 to 5, characterized in that the substrate has a bending elasticity in the range of 4360 to 9000 MPa.

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