JPH02162037A - Waterproof sheet - Google Patents

Abstract

PURPOSE:To fusion-adhere solvent with inexpensive tetrahydrofuran by laminating chloride made by chlorinating specific ethylene/alpha-olefin copolymer on a base cloth. CONSTITUTION:Chlorinated polyethylene having 0.945 or less of density, 20-45wt.% of chlorine content obtained by chlorinating ethylene/alpha-olefin copolymer having 3 pieces or more of short chain branch of 2C/1,000 or more C, 1-300 of MFR, and 10cal/g or less of crystallinity measured by a differential scanning calorimeter (DSC) is laminated on a base cloth. In this case, the alpha- olefin is desirably butene-1.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a waterproof sheet used for example as a roofing material. More specifically, the present invention relates to a waterproof sheet comprising 81 layers of a specific chlorinated material on a base fabric.

(Prior art and its problems) The polymers most commonly used for conventional waterproofing materials, such as roofing rates, and linings for tents, ponds, swimming pools, etc. (bond linings, tent linings), are mainly cheap and flexible. It is a plasticized polyvinyl chloride (so-called soft vinyl chloride) that can be made into a flexible sheet. In addition, there are waterproof sheets made partly of asphalt compositions for the same reason.

However, soft vinyl chloride has the problem of generating a bad odor due to volatilization of the plasticizer. Furthermore, asphalt-based materials are easily flammable and do not necessarily have good workability in construction.

Therefore, conventionally, as other synthetic polymer roofing materials,
Ethylene/propylene rubber (EPR), butyl rubber, etc. have been proposed. However, when these synthetic polymer systems are used in place of conventional soft vinyl chloride, it is necessary to develop a new application system including construction technology.

In other words, adhesive technology between sheets is generally important in the construction of waterproofing materials, including roof ingrates. is widely practiced.

Therefore, THFQ is a solvent for solvent welding that is capable of thermal welding and is conventionally used in soft vinyl chloride systems.
If solvent welding can be performed by using a conventional welding system, the conventional welding system can be applied as is, which is extremely convenient.

However, the synthetic polymer waterproof sheets proposed above, including the conventional chlorinated polyethylene made by chlorinating high-density polyethylene, have not always been satisfactory in solvent weldability, even though they have thermal weldability.

Tarpaulin sheets use a large amount of materials, and as mentioned above, it is important that they are inexpensive, including the construction techniques. However, it is natural that it would be uneconomical if conventional construction techniques could not be adopted and new construction techniques had to be developed.

As a result of intensive research in view of the above circumstances, the present inventors have found that the specific chlorinated product of the present invention has good properties, unlike conventional chlorinated polyethylene which is obtained by chlorinating high-density polyethylene with extremely few branches. Based on the surprising finding that it exhibits excellent THF weldability, we have developed a waterproof sheet with a structure in which a chlorinated product made by chlorinating a specific ethylene/me-olefin copolymer, also known as linear low-density polyethylene, is laminated on a base fabric. By doing so, the present invention has been completed.

(Means for Solving the Problems) That is, the present invention provides ethylene/
Laminated with chlorinated polyethylene obtained by chlorinating a Meolefin copolymer, the chlorine content is 20 to 45% by weight, the MFR is 1 to 300, and the degree of crystallinity is 10 cal/g or less as measured by differential scanning calorimetry (DSC). This invention relates to a waterproof sheet.

This will be explained in detail below.

The raw material polymer for the chlorinated product of the present invention is an ethylene/me olefin copolymer having a density of 0.945 or less, which is also referred to as linear low-density polyethylene. This polymer is produced by copolymerizing ethylene with an a-olefin using a Ziegler catalyst or a chromium catalyst consisting of a transition metal such as titanium, vanadium or zirconium and an organic metal such as alkyl aluminum. Depending on the polymerization pressure, the method is classified into low, medium, and high pressure polymerization methods, and any of these methods can be used. Also, in the reaction phase, the gas phase,
There are liquid phase and slurry polymerization methods, but either one can be used. For Ziegler-based catalysts, recent magnesium compound carriers such as magnesium chloride, and supported catalysts supported on silica carriers and the like may also be used as polymerization catalysts.

The α-olefin to be copolymerized is an α-olefin having 4 to 12 carbon atoms.
- It is an olefin. Specifically, they include butene-1,4-methylpentene-1, hexene-1, octene-1, decene-1, dodecene-1, and the like. Propylene is not preferred because the chlorinated product obtained from its ethylene copolymer has poor heat resistance. From this point of view, conventional so-called ethylene/
Propylene copolymer rubber is not preferred as the raw material resin of the present invention. Particularly preferred is butene-1 because it not only has good physical properties but is also an inexpensive comonomer. Further, other comonomers such as butadiene may also be used in combination.

02 or more short chain branches (J13/100OC or more, carbon number 2 (C
) In the case of an ethylene/me olefin copolymer having less than 3 short chain branches/100 OC, the solvent weldability of the chlorinated product of the copolymer with tetrahydrofuran is significantly inferior, although the reason is unknown. That is, even if tetrahydrofuran is used as a solvent, solvent welding is impossible. Moreover, when compared with the same chlorine content, a chlorinated product with poor flexibility is obtained, and conversely, if a larger amount of chlorine is reacted to make it flexible, a chlorinated product with poor thermal stability is obtained, which is not preferable. The upper limit of the number of short chain branches of 02 or more is not particularly limited. However, since chlorination is usually carried out by an aqueous suspension method, copolymers with too many short chain branches tend to cause book fourting during chlorination; Use one with 90 branches/100 QC or less.

Also, methyl branching is not preferred because its presence causes inferior #4 thermal properties of the chlorinated product obtained therefrom. Therefore, it is advantageous to have fewer methyl branches.

The density of the raw material ethylene/Meolefin copolymer of the present invention, also called linear low density polyethylene, is 0.945.
It is defined as: The density of high-density polyethylene usually exceeds 0.945, and as described below, it is critically inferior in weldability to solvents compared to conventional chlorinated high-density polyethylene. There is no particular restriction on the lower limit of the density of the copolymer, but if the density is too low, the amount of expensive α-olefin used will increase, and the copolymer will not be a cheap polymer. From this point of view, the lower limit is usually 0.8
Up to 80.

In addition, DSC of the raw material ethylene/Meolefin copolymer
Of course, the melting point is over 100℃,
Those having a temperature of less than 100°C can also be used, and there are no particular limitations on the amount of boiling 1n-hexane insoluble matter.

The above ethylene/me olefin copolymer is chlorinated and has a chlorine content of 20 to 45% by weight and an MFR of 1 to 300. DS
A chlorinated product having a crystallinity of 10 cal/g or less as measured by C is used in the roofing sheet of the present invention.

If the chlorine content is lower than 20%, the weldability with organic solvents will be poor, making it impossible to join the sheets. In addition, chlorinated materials have poor flexibility and are not preferred as materials for waterproof materials. 4
If it exceeds 5% by weight, the heat resistance and flexibility of the sheet will decrease, making it unsuitable.

MFR (g/l 0 minutes; JIS K?210 compliant, measurement temperature: 180°C, load 23.1kg) is:
It is 1-300. If the VFR is higher than 300, the mechanical properties of the sheet deteriorate, which is not preferable. Further, if the MFR is lower than 1, although the sheet properties are good, the processability during sheet molding is unfavorable. The VFR of chlorinated products is also related to its chlorine content, so it is not always the case that the raw material ethylene/
MI olefin copolymer MI (JIS K67
Compliant with No. 60, measurement temperature: 190°C, load: 2.13
kg). However, it is preferable to chlorinate the raw material ethylene/me olefin copolymer having an MI in the range of 0.1 to 50. MI less than 0.1
However, the processability of chlorinated products is poor, and on the other hand, if Ml exceeds 50
However, the mechanical properties of chlorinated materials are inferior, making them unsuitable as waterproof materials.

The crystallinity of chlorides is 10 when measured by DSC.
It is necessary that ea1/g or less. If the degree of crystallinity is higher than this, even if the degree of chlorination of the future chloride is high, the flexibility and thermal stability of the chloride will be poor.
In addition, its solvent welding properties are also poor, which makes it undesirable. Depending on the method of chlorination, for example, if chlorine is selectively introduced into the amorphous part of the copolymer, a chlorinated product with a high crystallinity exceeding 10 eal/g despite a relatively high chlorine content may be used. is obtained, but of course such a result is not preferable. The lower limit of the degree of crystallinity of the chloride is not particularly limited, and a chloride with no crystallinity at all may be used.

As a method for producing the chlorinated product used in the present invention, conventionally known chlorination methods such as an organic solvent method or an aqueous suspension method can be employed. It is usually chlorinated by an aqueous suspension method. In this method, a powdered ethylene/me olefin copolymer is suspended in water containing an appropriate surfactant, and chlorine gas is introduced to perform chlorination. During this chlorination, the molecular weight of the raw material, the particle size of the powder, the particle size distribution, the powder concentration, the type and amount of surfactant, the stirring speed, the supply rate of chlorine gas, the chlorination temperature, the multi-stage reaction, etc. The optimum reaction conditions should be determined accordingly. Preferably, the temperature is 70 to 80°C under appropriate pressure.
Chlorination is carried out while maintaining the temperature at °C or preferably above 90 °C.

The waterproof sheet of the present invention is a waterproof sheet formed by laminating the above chlorinated material on a base fabric.

Construction of a tarpaulin is rarely completed by placing a single sheet of tarpaulin at the construction site, but usually involves gluing two sheets together because the construction area is large or the construction shape is irregular. Is required. Furthermore, in order to improve the adhesive strength, this bonding is usually done by overlapping the plates, rather than by butting the end surfaces of the sheets together. In conventional PVC waterproofing, THF is used as mentioned above.
Adhesion by solvent welding is widely practiced.

Conventional synthetic polymers, including chlorinated polyethylene,
Solvent adhesion using HE was insufficient, but with the sheet of the present invention, the chlorinated layer is made of a polymer with good THF weldability, so overlay adhesion using THF welding, which is the conventional construction technique, is possible. is easy and convenient.

The waterproof sheet of the present invention is produced by adhering it to a base fabric by a press molding method, a calendering method, a heat welding method, or the like.

The above-mentioned chlorinated products include, for example, conventional chlorinated polyethylene obtained by chlorinating high-density polyethylene, low-density polyethylene, and EPDM, as long as their physical properties, particularly adhesive properties, are not deteriorated.

Polyvinyl chloride (PVC), chlorosulfonated polyethylene, EVA, EEA, natural rubber, butyl rubber,
S B R11TR, BR, 5-B-3 or S-1-
It is also possible to use a blend of any of the above-mentioned polymers, such as thermoplastic elastomers such as Type 8, hydrogenated products thereof, and the like. The chloride sheet may optionally contain suitable additives, such as tackifying resins, crosslinking agents, calcium carbonate, silica, various inorganic or organic fillers such as metal fibers and carbon fibers, antioxidants, weathering agents, and flame retardants. , colorants, etc. can be added.

As described above, the chlorinated product of the present invention has excellent THF solvent adhesion properties. However, mechanical strength etc. are not necessarily good. Therefore, in order to improve the mechanical strength while maintaining the flexibility of the waterproof sheet, the waterproof sheet of the present invention has a base fabric laminated thereon. Examples of the base fabric include polyester, nylon, vinylon, cellulose,
This is a base fabric made of fibers such as acrylic. These base fabrics are processed together with the chlorinated product of the present invention by a press molding method, a calendar molding method, etc. according to a conventional method to obtain a multilayered waterproof sheet.

(Manufacture of Sheet) The waterproof sheet of the present invention can be manufactured by a conventionally known method as described above. Typically, the chlorinated product is first formed into a sheet by a T-die method or a calendar method. The thickness of the sheet made of chloride of the present invention is 01
~10I*11, preferably 0.3 to 1.5 degrees.

The formed sheet can then be laminated with a base fabric by calender molding, press molding, heat welding molding, or the like to form a multilayer waterproof sheet.

(Solvent Welding) The waterproof sheet of the present invention can be easily adhered by the THF solvent welding method conventionally used for polyvinyl chloride waterproof sheets, and can provide sufficient adhesive strength. That is, THF may be adhered to the surfaces of two waterproof sheets that have been heated as necessary, and then the THF contact surfaces may be crimped together. The THF contact time is appropriately determined in consideration of the state of dissolution of the sheet surface by THF. Further, the crimping time is about 10 seconds to 30 minutes, but crimping can normally be completed in 10 minutes or less. Thereafter, the THF may be volatilized by heating or leaving as appropriate as necessary.

THE can be used in combination with other appropriate organic solvents to the extent that the weldability is not inhibited.

(Effects of the Invention) The waterproof sheet of the present invention is composed of a multilayer sheet having a chlorinated layer of a specific so-called linear low-density polyethylene that has good THF weldability. This is extremely convenient because the construction method used in the previous can be used as is. That is, by using a specific chlorinated compound, a strong adhesive surface can be formed by solvent welding with THF, and an adhesive strength comparable to that obtained by thermal welding can be obtained, which can destroy the base material if it is peeled off.

Also, base fabric and 1! sP! By doing so, a waterproof sheet with excellent mechanical strength while retaining flexibility can be obtained. Moreover, since the earth and stone are composed of chlorinated substances that have good weather resistance, it becomes a waterproof sheet that has good weather resistance.

Therefore, the waterproof sheet of the present invention is suitable for linings (bond linings, tent linings) for tents, ponds, swimming pools, etc., especially as roofing materials.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

Examples and Comparative Examples Here, the raw resins for each test piece and their chlorination methods are as follows.

Test pieces 1 to 5: Linear ethylene/butene-1 copolymer resins produced by vapor phase polymerization of a predetermined amount of ethylene and butene-1 using a Ziegler-based titanium chloride catalyst.

Test pieces 6 to 7: High-density polyethylene obtained by slurry polymerization of ethylene using a Ziegler catalyst of titanium chloride.

The chlorination method involves suspending powdered resin in water and first adding 10
After blowing chlorine gas at a temperature lower than 0°C to cause a certain degree of reaction, the temperature was then raised to 100°C and further chlorine gas was blown to complete chlorination.

Further, various measurement methods in Examples and Comparative Examples are as follows.

(Method for creating test pieces) The resin was placed in a mold with a thickness of 1.5 mm and heated at 150°C for 50 minutes.
After preheating for 1 minute, pressure molding was carried out at the same temperature for 5 minutes at 100 kg/ctIr-G, and then at 30°C at 100 kg/cIIr-G.
Created by cooling for 10 minutes under pressure of G.

(DSC crystallinity measurement method) Thickness 0.2: IJX A disk-shaped resin test piece with a diameter of 6 mm was attached to the DSC, heated to 430K, and after 5 minutes, the cooling rate was 10.
Cool to room temperature at a rate of 10°C/min, then heat at a temperature increase rate of 10°C/min, and measure at 330-430K to determine the degree of crystallinity.

(Tensile test) According to JIS K6301, a test piece was prepared using a No. 3 dumbbell and at a tensile speed of 200 M/min.

(Hardness) A test piece was prepared according to JIS K6301 and measured using a type A testing machine. Instantaneous values were obtained as the measured values.

(Solvent welding method): The chlorinated products listed in Table 2 and the polyester base fabric were laminated by a calendering method according to a conventional method to a thickness of 1.0 mm.
A laminated sheet of chlorinated material and base fabric was prepared. However, due to solvent welding, the edges were made to be a single layer of only chlorinated material. This was cut to create a test piece with a radius of 25w and a length of 100m.

Various organic solvents, including tetrahydalofuran, are applied to one side (the single layer of chloride at the end) of two laminated sheet test pieces at room temperature, and the two test pieces are immediately bonded together.

After pasting them together, they are pressed together for 10 minutes under a load of 1 to 5 g/cd.

(Evaluation method of solvent weldability): Immediately after pressing, two test pieces were manually subjected to T-peeling to measure the weldability. In addition, the same test was performed on the test pieces left indoors for 24 hours after compression. The results are shown in the following table according to the evaluation criteria below, and all evaluations of weldability are the average values of 10 sets of test pieces.

Table 1 shows the results of testing Test Piece 1 with different organic solvents, and Table 2 shows the results of testing various chlorinated test pieces.

The weldability evaluation criteria listed in Tables 1 and 2 are as follows.

0: Completely welded, and accurate adhesive force cannot be measured because the base material is destroyed.

○: Welded and has adhesive strength.

Δ: Although it is slightly welded, it can be peeled off with a small amount of force, and the adhesive strength is completely insufficient for adhesion of waterproof materials.

×: Not welded at all.

As can be seen from Table 1, among many organic solvents, only tetrahydrofuran exhibits specific weldability.

Furthermore, Table 2 shows that even if tetrahydrofuran is used, chlorinated high-density polyethylene has no soluble properties even when the content is high enough to improve weldability.

Table 1 (Various solvents)

Claims (2)

[Claims] (1) Chlorine content of 20 to 45% by weight, MFR of 1 to 300, obtained by chlorinating an ethylene/α-olefin copolymer having a density of 0.945 or less, 3 short chain branches of C2 or more/1000 carbons or more, A waterproof sheet made of a base fabric laminated with chlorinated polyethylene having a crystallinity of 10 cal/g or less as measured by a differential scanning calorimeter (DSC). (2) Claim 1, wherein the a-olefin is butene-1.
Waterproofing rate listed.