JP7589447B2 - Waterproof sheet - Google Patents

Description

The present invention relates to a waterproof sheet.

Waterproof sheets are installed on roofs and balconies of buildings to prevent water from penetrating into the interior. Because waterproof sheets are used outdoors, they deteriorate and lose their waterproofing performance when exposed to sunlight and heat for long periods of time. For this reason, efforts are being made to develop waterproof sheets that can maintain their waterproofing performance for a long period of time.

Patent Document 1 discloses a thermoplastic resin composition containing a vinyl chloride resin, an ethylene-carbon monoxide-vinyl acetate copolymer, and a thermoplastic urethane elastomer. The document states that the thermoplastic resin composition can be used as a wire coating material.

Patent Documents 2 to 6 disclose resin compositions and waterproof sheets that contain acrylic-grafted vinyl chloride resin and ethylene-carbon monoxide-vinyl acetate copolymer.

Japanese Unexamined Patent Publication No. 59-33345 JP 2017-132996 A JP 2017-132997 A JP 2017-132998 A JP 2017-132999 A JP 2017-133000 A

However, the conventional technologies described in Patent Documents 1 to 6 leave room for improvement in terms of long-term weather resistance and long-term durability.

The inventors focused on the ash concentration of each layer that makes up the waterproof sheet and discovered that by specifying this concentration, it is possible to achieve long-term weather resistance and long-term durability.

The present invention can be shown as follows.
According to the present invention,
The laminate is made of a plurality of layers each including a polyvinyl chloride resin, a plasticizer, and inorganic particles.
The laminate includes, as the layers, a back layer on the application surface side, an intermediate layer, and a front layer in this order ;
A waterproof sheet (excluding dynamic load-bearing flooring materials) in which the ash concentration of the back layer or the intermediate layer is higher than the ash concentration of the surface layer.
is provided.

The present invention provides a waterproof sheet with excellent long-term weather resistance and durability.

1 is a schematic cross-sectional view of a waterproof sheet according to an embodiment of the present invention. A schematic cross-sectional view of another waterproof sheet of this embodiment is shown.

The following describes an embodiment of the present invention with reference to the drawings. In all drawings, similar components are given similar reference symbols and descriptions are omitted where appropriate. In addition, "~" indicates "above" to "below" unless otherwise specified.

The waterproof sheet of the present embodiment is made of a laminate of multiple layers containing polyvinyl chloride resin, a plasticizer, and inorganic particles, and the ash concentration differs for each of the multiple layers.
The waterproof sheet of this embodiment will be described below with reference to a first embodiment and a second embodiment.

First Embodiment
The waterproof sheet 10 of this embodiment is a laminate comprising, in that order, a back layer 12 on the application side, a reinforcing material layer 14, and a front layer 16, and the ash concentration of the back layer 12 is higher than the ash concentration of the front layer 16.

(Back surface layer 12)
The back surface layer 12 contains a polyvinyl chloride resin, a plasticizer, and inorganic particles.
Examples of polyvinyl chloride resins include vinyl chloride homopolymers, butyl acrylate grafted vinyl chloride resins, (meth)acrylic grafted vinyl chloride resins, ethylene-vinyl acetate grafted vinyl chloride resins, etc. The back surface layer 12 may contain at least one selected from these. In the present embodiment, it is preferable to use vinyl chloride homopolymers from the viewpoint of the effects of the present invention.
The average degree of polymerization of the polyvinyl chloride resin is 700 or more and 3,000 or less.

As the plasticizer used in this embodiment, any plasticizer used in vinyl chloride resins can be used.
For example, at least one selected from the group consisting of phthalic acid-based plasticizers, adipic acid-based plasticizers, phosphoric acid-based plasticizers, trimellitic acid-based plasticizers, and polyester-based plasticizers can be used.
The plasticizer may be contained in an amount of preferably 10 to 100 parts by weight, more preferably 30 to 80 parts by weight, and particularly preferably 40 to 70 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin.

As the inorganic particles, inorganic particles that are usually added to waterproof sheets can be used.
Examples of inorganic particles include particles made of calcium carbonate, titanium dioxide, talc, mica, silica, etc., and particles made of calcium carbonate and titanium dioxide are preferred.
The average particle size of the inorganic particles is about 0.2 to 2 μm. The amount of inorganic particles to be added is determined taking into account the ash content.

The back layer 12 may contain other components in addition to those mentioned above, such as antioxidants, pigments, processing aids, stabilizers, and fillers.

(Reinforcement layer 14)
The reinforcing layer 14 can efficiently improve the rigidity and strength of the waterproof sheet 10, can obtain good shape stability by reducing shrinkage, and can also suppress the occurrence of cracks, breaks, etc. As the reinforcing layer 14, a woven or nonwoven fabric made of inorganic fibers such as glass fibers or organic synthetic fibers such as polyester fibers can be suitably used.

(Surface layer 16)
The surface layer 16 is composed of substantially the same components as the back layer 12, but the composition can be changed as appropriate.
The front surface layer 16 may contain, in addition to the other components listed for the back surface layer 12, an ultraviolet absorbing agent to impart light resistance.

(Waterproof sheet 10)
The waterproof sheet 10 of this embodiment comprises a back layer 12 located on the application surface side, a reinforcing material layer 14, and a front layer 16, in this order. The thickness of the back layer 12 is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.5 mm, and particularly preferably 0.4 to 1.2 mm. The thickness of the front layer 16 is preferably 0.2 to 3.0 mm, more preferably 0.3 to 2.0 mm, and particularly preferably 0.5 to 1.5 mm. The front layer 16 is preferably thicker than the back layer 12. The thickness of the reinforcing material layer 14 of the waterproof sheet is appropriately selected depending on the material constituting the reinforcing material layer 14 and the required strength, but is about 200 to 400 μm.

In the waterproof sheet 10 of this embodiment, the ash concentration of the back layer 12 is higher than that of the front layer 16. This makes it possible to provide a waterproof sheet with excellent long-term weather resistance and long-term durability. The ash content is measured in accordance with JIS K7250-(1) (2006).

The ash concentration of the back layer 12 is preferably 2 to 40% by weight, more preferably 5 to 35% by weight, and particularly preferably 10 to 30% by weight. The ash concentration of the front layer 16 is preferably 1 to 30% by weight, more preferably 2 to 25% by weight, and particularly preferably 3 to 20% by weight. It is preferable that the ash concentration of the back layer 12 is higher than that of the front layer 16. When the ash concentration is within the above range, a waterproof sheet with excellent long-term weather resistance and long-term durability can be provided.

The ash content of the back layer 12 and the front layer 16 contains a metal element. The metal element is preferably at least one selected from the group consisting of calcium, titanium, magnesium, aluminum, silicon, phosphorus, zinc, vanadium, and tin.
By including these metal elements in the ash, it is possible to provide a waterproof sheet having superior long-term weather resistance and long-term durability.

The waterproof sheet of this embodiment can be manufactured by heating and melting the resin composition at a predetermined temperature and forming the molten resin composition into a sheet.

Methods for forming into a sheet include a calendar method or an extrusion method. The waterproof sheet having a multilayer structure of this embodiment may be formed by forming the resin composition into a sheet by a calendar method, an extrusion method, or the like, and laminating and integrating the resin compositions constituting the other layers by a calendar method, or each resin composition may be formed into a sheet separately in advance by a calendar method or an extrusion method, and then laminated and integrated by a lamination method such as a lamination method. Also, each resin composition may be multilayered by co-extrusion.

Second Embodiment
The waterproof sheet 10 of this embodiment is a laminate comprising, in this order, a back layer 12 on the construction side, a reinforcing material layer 14, an intermediate layer 15, and a surface layer 16, with the ash concentration of the back layer 12 being higher than that of the surface layer 16, and the ash concentration of the back layer 12 or the intermediate layer 15 being the highest.
The back layer 12, the reinforcing material layer 14, and the front layer 16 are the same as those in the first embodiment, and therefore the description thereof will be omitted.

Intermediate layer 15
The intermediate layer 15 is composed of substantially the same components as the back surface layer 12 of the first embodiment, but the composition can be appropriately changed. The intermediate layer 15 may be a single layer or a multi-layer structure of two or more layers.

(Waterproof sheet 10)
The waterproof sheet 10 of this embodiment comprises a back layer 12 located on the application surface side, a reinforcing material layer 14, an intermediate layer 15, and a front layer 16, in this order.

In this embodiment, the thickness of the back layer 12 is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.5 mm, and particularly preferably 0.4 to 1.2 mm. The thickness of the intermediate layer 15 is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.5 mm, and particularly preferably 0.4 to 1.2 mm. The thickness of the surface layer is preferably 0.2 to 3.0 mm, more preferably 0.3 to 2.0 mm, and particularly preferably 0.5 to 1.5 mm. The thickness of the surface layer 16 is greater than that of the back layer 12 or the intermediate layer 15, and it is preferable that the surface layer 16 is the thickest. The thickness of the reinforcing layer 14 of the waterproof sheet is appropriately selected depending on the material constituting the reinforcing layer 14 and the required strength, but is about 200 to 400 μm.

The ash concentration is highest in the back layer 12 or the intermediate layer 15. This allows for the provision of a waterproof sheet with excellent long-term weather resistance and long-term durability. The ash content is measured in accordance with JIS K7250-(1) (2006).

The ash concentration of the back layer 12 is preferably 2 to 40% by weight, more preferably 5 to 35% by weight, and particularly preferably 10 to 30% by weight. The ash concentration of the intermediate layer 15 is preferably 2 to 40% by weight, more preferably 3 to 30% by weight, and particularly preferably 5 to 25% by weight. The ash concentration of the surface layer 16 is preferably 1 to 30% by weight, more preferably 2 to 25% by weight, and particularly preferably 3 to 20% by weight. The ash concentration of the back layer 12 is higher than that of the surface layer 16, and the ash concentration of the back layer 12 or the intermediate layer 15 is the highest. When the ash concentration is in the above range, a waterproof sheet with excellent long-term weather resistance and long-term durability can be provided.

The ash content of the back layer 12, the intermediate layer 15 and the surface layer 16 contains a metal element. The metal element is preferably at least one selected from the group consisting of calcium, titanium, magnesium, aluminum, silicon, phosphorus, zinc and tin.
By including these metal elements in the ash, it is possible to provide a waterproof sheet having superior long-term weather resistance and long-term durability.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted as long as they do not impair the effects of the present invention.
In the first and second embodiments, a laminated structure in which the reinforcing material layer 14 does not exist may be used.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

(Examples 1 to 3, Comparative Examples 1 and 2)
The materials listed in Table 1 were mixed in the compounding ratio to prepare a resin composition for each layer. The resin composition for each layer was then melted at a temperature of 170°C and molded into a sheet by extrusion. Each sheet was then laminated and integrated with a net to produce a waterproof sheet having a back layer, a reinforcing layer (net), an intermediate layer, and a surface layer laminated in that order.
The compositions of the resin compositions of the examples and comparative examples are shown in Table 1.

<Evaluation of waterproof sheets>
[Weather resistance evaluation]
Using a metal halide lamp weather resistance tester (Metal Weather, manufactured by Daipla Wintes), light emitted from a metal halide lamp as a light source was irradiated continuously from the normal direction onto the surface of the waterproof sheet of each Example and Comparative Example for 900 hours, and then the elongation of the waterproof sheet was measured, and the change from the elongation of the waterproof sheet before the test was calculated according to the following formula and evaluated according to the following criteria. The results are shown in Table 1.
Formula: (elongation rate of waterproof sheet after test/elongation rate of waterproof sheet before test) x 100
(standard)
〇: 70% or more,
△: Less than 70% 60% or more ×: Less than 60%

[Ash content]
The ash concentration was measured in accordance with JIS K7250-(1) (2006).

The components listed in Table 1 are as follows.
Polyvinyl chloride resin: ZEST 1300Z (manufactured by Shin-Daiichi Vinyl Co., Ltd.)
Plasticizer: bis(2-ethylhexyl) phthalate (DOP) (manufactured by Mitsubishi Chemical Corporation)

As is clear from Table 1, the waterproof sheets in the examples had excellent weather resistance and durability. In contrast, the comparative examples did not produce satisfactory results.

10 Waterproof sheet 12 Back layer 14 Reinforcing material layer 15 Intermediate layer 16 Surface layer

Claims (11)

The laminate is made of a plurality of layers each including a polyvinyl chloride resin, a plasticizer, and inorganic particles.
The laminate includes, as the layers, a back layer on the application surface side, an intermediate layer, and a front layer, in this order;
the inorganic particles contained in the back surface layer include calcium carbonate and titanium dioxide;
A waterproof sheet in which the ash concentration of the back layer or the intermediate layer is higher than the ash concentration of the surface layer (excluding the back layer which is formed by adding 50 to 300 parts by weight of spindle-shaped or cubic-shaped precipitated calcium carbonate to 100 parts by weight of polyvinyl chloride resin ). The waterproof sheet according to claim 1, wherein the thickness of the back layer is 0.1 to 2.0 mm, and the thickness of the front layer is 0.2 to 3.0 mm. The waterproof sheet according to claim 2, wherein the surface layer is thicker than the back layer. The waterproof sheet according to any one of claims 1 to 3, wherein the intermediate layer is made up of multiple layers. The waterproof sheet according to any one of claims 1 to 4, wherein the thickness of the back layer is 0.1 to 2.0 mm, the thickness of the intermediate layer is 0.1 to 2.0 mm, and the thickness of the surface layer is 0.2 to 3.0 mm. The waterproof sheet according to any one of claims 1 to 5, wherein the surface layer is the thickest. The waterproof sheet according to any one of claims 1 to 6, wherein the polyvinyl chloride resin is a homopolymer of vinyl chloride. The waterproof sheet according to any one of claims 1 to 7, wherein the ash contains a metal element. The waterproof sheet according to claim 8, wherein the metal element is at least one selected from calcium, titanium, magnesium, aluminum, silicon, phosphorus, zinc and tin. The waterproof sheet according to any one of claims 1 to 9, wherein the inorganic particles contained in the surface layer or the intermediate layer include at least one selected from calcium carbonate and titanium dioxide. The waterproof sheet according to any one of claims 1 to 10, comprising a reinforcing layer between the back layer and the intermediate layer.

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