JPH10296915A - Waterproof sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve joining strength and properties of application and to prevent occurrence of crease in a joined part by laminating a thermoplastic elastomer containing a polystyrene component in a specified range and made by block polymerization and a fabric base. SOLUTION: A thermoplastic elastomer 2 which is supplied into an extruder 1 and which contains a polystyrene component of 10-40 wt.% and is made by block polymerization is melted by heating at about 190-250 deg.C, passed through a T-die 3 and molded in the shape of a sheet. This thermoplastic elastomer 2 molded in the shape of the sheet is led in, in a softened state and together with a fabric base 4, between a pressure roll 5 made of rubber and a cooling roll 6 made of metal and is pressed there by a linear pressure of about 80-150 kgf/cm to be laminated so that a waterproof sheet 7 of a two-layer structure be obtained. According to this constitution, the sheet being excellent in joining strength and properties of application and free from occurrence of crease in a joined part is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof sheet used as a waterproof lining material on the roof of a building, civil engineering work on a pond, and the like.

[0002]

2. Description of the Related Art Conventionally, asphalt has been generally used as a waterproof lining material on the roof of a building, civil engineering work of a pond, and the like.
In addition, the construction is complicated due to the use of the thermal method, and the asphalt itself has disadvantages such as poor weather resistance and poor substrate followability.

[0003] To compensate for these drawbacks, waterproof sheets such as vulcanized rubber sheets and polyvinyl chloride sheets have recently been provided as waterproof lining materials.
Such a waterproof sheet is generally a long body, and after being transported to the site in a state of being wound up in a roll, the ends in the width direction of the waterproof sheet are overlapped by about 5 cm and laid, and the overlapped end, Is intended to integrate the waterproof layer by bonding between the base and the waterproof sheet as required. Therefore, the waterproof sheet is required to have a high bonding property between the sheets, and in addition, since it is used by being bent at a corner rising portion or the like at the time of construction, the waterproof sheet has flexibility that can be easily bent. That is, excellent workability is required.

[0004]

Of the above waterproof sheets, the rubber sheet is excellent in weather resistance and followability to the substrate, but requires the use of an adhesive to bond the rubber sheets. In addition, it takes a lot of time and labor to construct, and there is a problem that there are many water leakage accidents from the bonded portions of the sheets due to uneven application of the adhesive.

[0005] On the other hand, polyvinyl chloride sheets are excellent in waterproofness because they can be bonded to each other by heat fusion, but a plasticizer must be added to ensure flexibility. Therefore, in low temperature conditions such as winter, when the plasticizer itself has a high viscosity, the hardness of the sheet becomes high and the workability is poor, and the plasticizer oozes from the inside of the sheet for a long period of time, causing deterioration of the sheet and long term stability It has the disadvantage of lacking in properties.

Accordingly, an object of the present invention is to provide a waterproof sheet having high bonding strength between sheets and excellent workability.

[0007]

Means for Solving the Problems The present inventor has focused on the selection of a material instead of the vulcanized rubber sheet and the polyvinyl chloride sheet, and as a result of repeated experiments and examinations, as a result, a thermoplastic elastomer (hereinafter referred to as “TPE”) ) Is effective as a waterproof sheet. Among them, styrene-based TPE or olefin-based resin produced by block polymerization and ethylene-propylene-diene-based rubber (hereinafter referred to as “EPDM”) containing a polystyrene component
Olefinic TPE produced by blending
Has found that the sheet has excellent bonding properties at the time of heat fusion.

[0008] The olefin-based TPE referred to here is of a type that is produced by simply mechanically blending an olefin-based resin and EPDM.
M is crosslinked, and even polymer alloys containing the crosslinked EPDM as a dispersed phase are included. In addition, as the olefin-based resin, for example, polyethylene, polypropylene and the like correspond.

Here, TPE is a material which flows when heated and can be molded in the same manner as ordinary thermoplastics, and exhibits rubber elasticity at room temperature. Depending on the main components, styrene, vinyl chloride, olefin System, urethane system,
It is classified into ester type, polyamide type and the like.

[0010] When selecting a styrene-based or olefin-based TPE from the above, in addition to the above-described bonding properties by heat fusion, hardness, water resistance, heat resistance, and the like which affect workability are considered.
The evaluation was performed by comprehensively evaluating weather resistance, price, and the like.

FIG. 1 shows the relationship between the content of main constituents and TP.
E is a diagram showing the bonding strength and the Shore A hardness of E,
The joining strength is indicated by a solid line, and the Shore A hardness is indicated by a broken line.

In the figure, (a) is a styrene-based T produced by block polymerization of a polystyrene component and a polybutadiene component.
In the PE, the case where the content of the polystyrene component is changed is shown, and (b) shows polypropylene (hereinafter referred to as “PP”) as an olefin resin among olefin TPEs produced by blending an olefin resin and EPDM. ) Is used to change the content of PP. The measurement of the joint strength and the Shore A hardness was performed according to JIS K6301.

As a result, in order to satisfy 10 kgf / 25 mm which is a sufficient value for the bonding strength between the sheets, in FIG. %that's all,
In (b), 40 wt. % Was found to be required.

The above-mentioned TPE is not limited to the one shown in FIG. 1. For example, it is possible to use a polyisoprene component in place of the polybutadiene component in (a). Also obtains a result equivalent to (a). In (b), it is also possible to use polyethylene instead of PP. Also in this case, a result equivalent to (b) is obtained. In addition, it is also possible to use a hydrogenated material for improving the weather resistance.

The TPE thus obtained is excellent in waterproofness and flexibility, and can be used alone. That is, a so-called insulation method is adopted in which the widthwise ends of the long TPE sheet are partially overlapped and laid, and the overlapped ends are heat-sealed to form an integrated waterproof layer. It becomes possible.

However, the TPE alone has a large linear thermal expansion coefficient, and wrinkles are generated at the joints due to the difference in expansion between the heated end and the unheated peripheral portion during thermal fusion. Furthermore, since TPE undergoes plastic deformation at a high temperature due to its properties, the wrinkles once generated are preserved as they are, which causes a problem that the appearance after construction is inferior.

Furthermore, since the coefficient of linear thermal expansion is large, there is also a problem that the waterproof layer has ripples at high temperatures such as in summer.

The present inventor has further studied and found that, in order to prevent the occurrence of wrinkles at the joint,
It has been found that it is effective to laminate a base fabric having a small linear thermal expansion coefficient on TPE. Specifically, the linear thermal expansion coefficient of the TPE alone in the sheet surface direction of about 9.0 × 10 ⁻⁵ mm / mm / ° C. at 20 to 70 ° C. is calculated to be 2.0 × 10 ⁻ If it is suppressed to ⁵ mm / mm / ° C. or less, wrinkles can be prevented.

The base fabric to be laminated on the TPE may be either a woven fabric or a non-woven fabric. The material of the fabric may be a synthetic fiber, a natural fiber, a glass fiber, or the like as long as the coefficient of linear thermal expansion of the laminated waterproof sheet can be suppressed. Can be used without particular limitation. However, those made of synthetic fibers are preferable because they have good adhesion to TPE and can be reduced in weight when formed into a waterproof sheet.

Further, since the waterproof sheet is used after being bent at a corner portion of a wall surface or the like, the base cloth is required to have flexibility enough to be easily bent. From that viewpoint, when the base fabric to be used is made of synthetic fiber, the fiber thickness is 500 to 2,000 denier and the basis weight is 4
The weight is preferably 0 to 200 g / m ² , and particularly when a woven fabric is used, a plain weave having 5 to 30 warp yarns / inch and 5 to 30 weft yarns / inch is preferable.

The thickness of the base fabric to be used varies depending on the material thereof, but it is generally preferably 10 to 60% of the thickness of the waterproof sheet after the base fabric is laminated, and particularly preferably 20 to 60%.
It is preferably about 50%. When the thickness of the base fabric is less than 10% of the thickness of the waterproof sheet, the effect of suppressing the linear thermal expansion coefficient is low, and when the thickness is 60% or more, the thickness of the TPE layer becomes thin and the function as the waterproof sheet may be impaired. It is.

Such a base fabric and TPE each have excellent flexibility and workability when used alone, but when both are laminated to form a waterproof sheet, the flexibility and workability deteriorate. Sometimes. The present inventor has conducted various experiments and found that if the Shore A hardness of the TPE is 80 or less, the flexibility and workability of the waterproof sheet do not decrease even when the base fabric is laminated.

Therefore, in the TPE shown in FIG. 1, in FIG.
%, And in (b), 40 to 80 wt. %, It has been found that a waterproof sheet having excellent bonding strength and workability can be obtained as a waterproof sheet and having no wrinkles at the joints, and the present invention has been completed.

That is, the waterproof sheet according to the present invention comprises:
0-40 wt. % TPS or olefin resin produced by block polymerization, containing 40% polystyrene component
0 wt. % And ethylene-propylene-diene rubber 60
~ 20 wt. % Of TPE and a base fabric are laminated.

As described above, by laminating the TPE having the specific composition and the base cloth, the bondability of the sheet bonding portion is good, wrinkles are prevented from being generated at the time of heat fusion, and the workability is excellent. You can get a waterproof sheet. Furthermore, since such a waterproof sheet has a low linear thermal expansion coefficient not only at the end of the sheet but also over the entire sheet, it does not cause ripples even at high temperatures such as in summer.

As the waterproof sheet according to the present invention, TPE
TP on both sides of the base fabric in addition to the two-layer structure where
It is also possible to adopt a configuration having a three-layer structure in which E is laminated.

The waterproof sheet having the two-layer structure of the above construction is
When the base fabric is laminated over the entire width of the sheet, the TPE and the base fabric may come into contact with each other at the joint where the sheet end portions are overlapped, and the heat fusion may be insufficient. Therefore, in the present invention, a long body having a two-layer structure in which a TPE and a base cloth are laminated, and at least one of both ends in the width direction of the long body, only the TPE having a predetermined width is used as the long body. Can be adopted as a single-layer structure formed in the longitudinal direction.

As described above, by forming a single-layer structure portion composed only of TPE, even a waterproof sheet having a two-layer structure can be reliably heat-sealed.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic view of an apparatus for manufacturing a waterproof sheet having a two-layer structure according to the present invention. In the figure,
Reference numeral 1 denotes an extruder, in which a styrene-based or olefin-based thermoplastic elastomer 2 supplied into the machine is 190
It is heated and melted at about 250 ° C. and formed into a sheet shape through the T die 3.

The thermoplastic elastomer 2 formed into a sheet is introduced into a softened state together with the base cloth 4 between a rubber pressure roll 5 and a metal cooling roll 6, where it is about 80 to 150 kgf / cm. The waterproof sheet 7 having a two-layer structure is obtained by pressurizing and laminating with the linear pressure. The waterproof sheet 7 is cooled by a cooling roll 6 set at 80 to 120 ° C., and then wound around a winding roll (not shown).

FIG. 3 is a sectional view of the waterproof sheet 7 having a two-layer structure. At the interface between the two layers of the waterproof sheet 7, the thermoplastic elastomer 2 partially penetrates into the fibers of the base cloth 4, whereby the two layers are firmly adhered.

In the waterproof sheet 7 having a two-layer structure,
When the single-layer structure is formed, the width of the thermoplastic elastomer 2 in the width direction is made longer than the width of the base fabric 4, and the widthwise central portions of the two are laminated together to form the waterproof sheet 7. A single-layer structure can be formed at both ends in the width direction. In addition, by laminating both ends in the width direction, the single-layer structure can be formed only on the other end side.

FIG. 4 is a schematic view of an apparatus for manufacturing a three-layer waterproof sheet. In the present embodiment, the thermoplastic elastomer 2 is extruded into a sheet while being in a softened state from the extruder 1 installed in the up and down direction of the base cloth 4 sent out from the roll, and cooled while sandwiching the base cloth 4. It is introduced between the rolls 4 and pressed and laminated by the same linear pressure as described above. The waterproof sheet 8 having a three-layer structure thus obtained is cooled by the cooling roll 4 set at 80 to 120 ° C. simultaneously with the pressurization, and is taken up by a take-up roll.

FIG. 5 is a sectional view of the waterproof sheet 8 having a three-layer structure. In the waterproof sheet 8, the thermoplastic elastomer 2 is laminated on both sides of the base cloth 4, and at the interface between the layers, as in the case of the waterproof sheet 7, the thermoplastic elastomer 2 partially penetrates into the fibers of the base cloth 4, Thereby, each layer is firmly adhered.

As the TPE, a commercially available product may be used as long as the content of the polystyrene component or the olefin resin is a predetermined value. For example, the following materials can be used.

(Trade name, grade) (Manufacturer) [Styrene TPE] Lavalon, SE7400 Mitsubishi Yuka Corp. Septon, CE002 Kuraray [Olefin TPE] Surlink, 3170 DSM Thermoplastic Elastomer Santoplane , 101-73 Advanced Elastomer Systems Inc. As the base fabric, for example, the following can be used.

(Product name, grade) (Manufacturer) [Polyester woven fabric] TF, 5 × 5, 10 × 10, etc. Teijin Limited [Polyester nonwoven fabric] Balcompo, HP6050G Toyobo Co., Ltd. Valcomo, HP6200G, etc. The above waterproof sheet is, for example, about 20 m × 1 m × 1.2 m
m, and after being transported to the site in a state of being wound up in a roll, the TPE layer side is directed upward, and the widthwise ends of the waterproof sheet are laid together by about 5 cm, and the overlapped ends are laid. An integrated waterproof layer is formed by heat-sealing the two with each other using an automatic heat-sealing machine or the like.

The heating temperature for heat fusion may be such that the surface temperature of the waterproof sheet is equal to or higher than the melting temperature of TPE and lower than the heat deterioration temperature, preferably 190 to 230 ° C. it is sufficient to crimp the joint with sufficient pressure, typically 10 kgf / cm ² or more, preferably crimped at a pressure of 20~40kgf / cm ^2.

At this time, when the width direction ends of the waterproof sheet having the two-layer structure are overlapped with each other, the end of the single-layer structure portion is overlapped on the end of the two-layer structure side and heat-sealed. I do.
In this way, the joint where the ends are overlapped with each other is T
The PEs come into contact with each other, so that the heat fusion can be reliably performed.

[0040]

EXAMPLE Next, a waterproof sheet was actually prepared using the TPE and the base cloth. In addition, as a waterproof sheet,
Two types of sheets were prepared, a two-layer structure sheet in which TPE and a base fabric were laminated one by one, and a three-layer structure sheet in which TPE was laminated on both sides of the base fabric, and both sheets were 1.20 mm in thickness. Further, in the two-layer structure sheet, a single-layer structure portion having a width of 5 cm was formed on one of both ends in the width direction. The contents are described below.

(Example 1) As TPE, an olefin-based Surlink 3170 (DSM Thermoplastic) was used.
This was supplied to an extruder heated to 210 ° C. and melted, and extruded from a T-die to form a sheet. On the other hand, as the base fabric, a balcompo HP605, which is a nonwoven fabric made of polyester, is used.
Using 0 G (weight per unit area: 50 g / m ² , thickness: 0.30 mm; manufactured by Toyobo Co., Ltd.), the base fabric and the softened TPE sheet are introduced into a pressure roll, and the pressure is set to 80 to 150 kgf / c.
The waterproof sheet having a thickness of 1.20 mm was obtained by laminating under a linear pressure of m.

At this time, the thickness of the TPE sheet used for preparing the waterproof sheet having a two-layer structure is formed to be slightly thicker than 0.90 mm. The linear pressure was adjusted so as to bite the part, and the thickness of the waterproof sheet was set to 1.20 mm.

Further, the length of the TPE and the base cloth in the width direction is increased by 5 cm, and the two ends of the two in the width direction are aligned to be laminated, so that the width 5c is added to the other end side of the waterproof sheet.
m was formed.

The thickness of the two TPE sheets used for producing the three-layer waterproof sheet is formed slightly thicker than 0.45 mm, and the linear pressure is adjusted in the same manner as described above.
The thickness of the waterproof sheet was 1.20 mm.

Example 2 Balcomo HP6 was used as a base cloth.
100G (weight per unit area: 100 g / m ² , thickness: 0.30 mm;
Waterproof sheets having a two-layer structure and a three-layer structure were obtained in the same manner as in Example 1 except that Toyobo Co., Ltd. was used.

(Example 3) As a base cloth, Balcomo H
P6200G (weight per unit area: 200 g / m ² , thickness: 0.60 m
m; Toyobo Co., Ltd.) was used. Further, a TPE sheet molded slightly thicker than 0.60 mm is used for forming a waterproof sheet having a two-layer structure, and a TPE sheet molded slightly thicker than 0.30 mm is used for forming a waterproof sheet having a three-layer structure. A waterproof sheet having a two-layer structure and a three-layer structure was obtained in the same manner as in Example 1 except that the waterproof sheet was used.

(Example 4) As a base cloth, TF5 × 5 (thickness 0.38 mm, plain weave,
Yarn thickness 500 denier, warp 30 yarns / inch, weft 30
Book / inch; manufactured by Teijin Limited). Furthermore, a TPE sheet slightly thicker than 0.82 mm is used for forming a two-layer waterproof sheet, and a TPE sheet slightly thicker than 0.41 mm is used for forming a three-layer waterproof sheet. Other than that, in the same manner as in Example 1,
Waterproof sheets having a two-layer structure and a three-layer structure were obtained.

(Example 5) TF10 × 10 (0.55 mm thick, plain weave,
Thickness 1000 denier, 10 warps / inch, 1 weft
0 / inch; manufactured by Teijin Limited). In addition, 2
A TPE sheet molded slightly thicker than 0.65 mm was used for making a waterproof sheet having a layer structure, and a TPE molded slightly thicker than 0.33 mm was used for making a waterproof sheet having a three-layer structure. In the same manner as in Example 1, two-layer and three-layer waterproof sheets were obtained.

(Comparative Example 1) Surlink 3170 (manufactured by DSM Thermoplastic Elastomer Co., Ltd.) as the TPE was molded to a thickness of 1.20 mm, and this was used alone as a waterproof sheet.

With respect to the two-layer sheet and the three-layer sheet prepared in each example as described above, the linear thermal expansion coefficient in the sheet surface direction was measured. Further, a waterproof layer was actually formed by an insulation method using the prepared waterproof sheet, and the workability, bonding strength, and presence or absence of wrinkles of the waterproof sheet were examined.

(Measurement of Linear Thermal Expansion Coefficient) First, in order to evaluate the occurrence of wrinkles, the linear thermal expansion coefficient of the waterproof sheet in the sheet surface direction was measured under the following measurement conditions. The coefficient of linear thermal expansion is such that an elongated sample is set upright,
It was measured by applying a load thereon and changing the temperature around the sample to detect the amount of expansion and contraction of the sample. However, the prepared two-layer and three-layer waterproof sheets have a thickness of 1.20 m.
Since the sample is m, if the sample is placed vertically, the sample may be bent by the expansion and contraction of the sample itself, and the correct amount of expansion and contraction may not be measured. Therefore, for actual measurement, a sample obtained by laminating two sheets in the thickness direction was used as a sample. That is, the TPE layers of the two sheets were opposed to each other, and the surface of the TPE layer was softened by applying hot air. In this state, the two sheets were superimposed and heat-sealed at a linear pressure of 30 kgf / cm. The conditions for measuring the linear thermal expansion coefficient are as follows. [Linear thermal expansion coefficient measurement conditions]-Measuring equipment: PTC-10A manufactured by Rigaku Denki Co.-Sample shape: length 20 x width 5 x thickness 2.4 (mm)-Sample weight: 7 g

(Formation of Waterproof Layer) The waterproof sheets prepared in each of the above examples were laid on a concrete substrate with their sheet width direction ends overlapped by 5 cm, and were heat-sealed using an automatic hot-air fusing machine. . At this time, in the two-layer structure sheet, the end portion on the single-layer structure portion side was overlapped on the end portion on the two-layer structure side and heat-sealed. The conditions for the heat fusion are as follows.
In addition, when laying the waterproof sheet on the concrete base, the workability of whether or not the bending work can be easily performed at the corner rising portion by following the shape of the waterproof sheet base was also examined. [Heat fusion conditions] TPE surface temperature: 200 to 210 ° C Pressure: 30 kgf / cm ²

Table 1 shows the structure and characteristics of the waterproof sheets in Examples 1 to Comparative Example 1 described above.

[0054]

[Table 1]

From Table 1, it can be seen that all the waterproof sheets have good workability at the corner rising portion of the concrete foundation. Further, the coefficient of linear thermal expansion is 9 × 10 ⁻⁵ mm /
Although the wrinkles occurred in the waterproof sheet of Comparative Example 1 (TPE alone) showing a large value of mm / ° C., the linear thermal expansion coefficient was 2.0 × 10 ⁻⁵ mm / mm / ° C. or less. No wrinkles were observed on any of the waterproof sheets of Examples to 5. In addition, all the waterproof sheets have good bending workability, and the bonding strength between the sheets by heat fusion is 10%.
kgf / 25 mm or more, and a waterproof sheet excellent in waterproofness and workability was obtained.

[0056]

As is clear from the above description, the present invention relates to a thermoplastic elastomer containing a predetermined amount of a polystyrene component, produced by block polymerization, or a predetermined amount of an olefin resin and an ethylene-propylene-diene rubber. A waterproof sheet made by laminating a thermoplastic elastomer manufactured by blending with a base cloth is used as a waterproof sheet, so that the waterproof sheet has excellent jointability at the joint of the waterproof sheet, and has no wrinkles at the joint, and has excellent workability. You can get a sheet.

Further, since a single-layer structure made of only thermoplastic elastomer is formed on at least one of both ends in the width direction of a long waterproof sheet having a two-layer structure, even in a waterproof sheet laminated with a base cloth, Thermal fusion can be performed reliably.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a view showing a joining strength and a Shore A hardness of a TPE.
(B) shows a change state of the olefin-based TPE.

FIG. 2 is a schematic view of an apparatus for manufacturing a waterproof sheet having a two-layer structure.

FIG. 3 is a sectional view of a waterproof sheet having a two-layer structure.

FIG. 4 is a schematic view of an apparatus for manufacturing a three-layer waterproof sheet.

FIG. 5 is a sectional view of a three-layer waterproof sheet.

[Description of Signs] 1 Extrusion molding machine 2 Thermoplastic elastomer 3 T die 4 Base cloth 5 Pressure roll 6 Cooling roll 7 2-layer waterproof sheet 8 3-layer waterproof sheet

Claims (3)

[Claims] Claims: 1. A waterproof sheet in which a thermoplastic elastomer produced by block polymerization and containing a base fabric and containing a polystyrene component by weight is laminated. 2. An olefin resin of 40 to 80 wt. % And ethylene-propylene-diene rubber 60 to 20 wt.
% Thermoplastic elastomer produced by blending
A waterproof sheet laminated with a base fabric. 3. A long body having a two-layer structure obtained by laminating the thermoplastic elastomer and the base cloth, wherein at least one of both ends in the width direction of the long body has a predetermined width. 3. The waterproof sheet according to claim 1, wherein the waterproof sheet is a single-layer structure formed by forming only a layer in a longitudinal direction of the elongated body.