JPS6135312B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is directed to asphalt, which is suitable for asphalt waterproofing work mainly on the roofs of buildings. It concerns roofing. Specifically, asphalt is characterized by using a water-impermeable core sheet containing polyethylene synthetic pulp and forming a polyethylene melt layer. It is roofing. Its purpose is asphalt. A water-impermeable sheet is used as the core material sheet of the roofing, and by preventing water from entering the inside of the asphalt waterproof layer, aging is prevented, durability is improved, and the weight of the waterproof layer is reduced. Conventional asphalt. The core material for roofing is base paper such as pulp, waste paper, rag fiber, synthetic fiber, inorganic fiber, or nonwoven fabric. Even if such a sheet is impregnated with asphalt, its water absorption rate is 20%.
% or more, and its water permeability is also very high. Even if coating asphalt is applied to both sides of the asphalt-impregnated sheet, the coating asphalt itself has some water permeability, and after many years of use,
Water permeability increases due to surface cracks and aging,
It is well known in the industry that moisture entering the asphalt waterproofing layer accelerates aging to the inside, deteriorating the strength, extensibility, and elasticity of the asphalt waterproofing layer, resulting in a loss of durability. . The permeability coefficient of blown asphalt for coating is 9×
Although it is about 10 ^-9 gcm/cm ² mmHghr, it has a large effect on the water resistance of the waterproof layer. On the other hand, the asphalt waterproof layer is made by alternately laminating asphalt and roofing, and usually uses 3 to 5 roofing layers to reduce aging caused by water permeation and improve durability. However, since the core materials of asphalt and roofing have water permeability, aging of the inside of the waterproof layer due to infiltrated moisture is inevitable, which impairs durability. Furthermore, as a result of using a large number of laminated layers, the weight of the waterproof layer increases significantly, and in modern architecture, it is now desired to make the waterproof layer lighter. Therefore, roofing has been proposed in which a plastic sheet or aluminum foil sheet is used as a non-water permeable core material and asphalt is coated, but these have poor adhesion with asphalt and have drawbacks such as delamination or peeling of the applied asphalt. Therefore, it could not be used. 〓〓〓〓〓
In view of the current situation, the present invention has been developed to improve all the drawbacks of the conventional roofing body. The thickness of the asphalt can be made thin, and even when multiple layers of this are used for waterproofing construction on rooftops, floors, etc., the asphalt layer sandwiched in between will reliably block water intrusion and prevent aging. In addition, the overall thickness of the waterproof construction layer can be reduced, the weight of the waterproof layer can be reduced, and a waterproof layer with reliable durability can be obtained. That is, the present invention heat-presses paper made of 40-60% by weight of polyethylene synthetic pulp with a melting point of 90-140°C, vegetable fibers and glass fibers as main raw materials,
Asphalt made by melting and rolling polyethylene synthetic pulp, binding the fibers together to form an impermeable layer, and using asphalt as a core material, and coating asphalt on at least one surface of the core material sheet. Roofing. It is. In the present invention, the polyethylene synthetic pulp has the trade names SWP-E and SWP-UL (manufactured by Mitsui Petrochemicals KK), and is a pulp-like, multi-branched, low-melting polyethylene fiber. average fiber length
0.6-1.6mm, specific gravity 0.95, well dispersed in water, suitable for mixed papermaking with pulp. Melting point is 90℃~140℃
℃, and when hot-pressing is performed at a temperature above the melting point,
Forms a water-impermeable layer and improves sheet stretchability. However, in order to bind and integrate polyethylene synthetic pulp with other fibers to form an impermeable layer, it is necessary to
It is necessary to mix and use 60% by weight. If it is less than 40% by weight, it will not be possible to form a sufficient water-impermeable layer, and if it is more than 60% by weight, the amount of vegetable fibers and glass fibers will be reduced, resulting in improved dimensional stability, toughness, and cyclic resistance. Since the loadability deteriorates, it is necessary to select from the above range. Glass fibers are suitable for roofing dimensional properties, ie cold. Heat. It serves to prevent elongation and shrinkage due to aging and increase strength. In addition, the high-temperature rigidity is increased to strengthen the stiffness during lamination work using heated asphalt, making it less likely to wrinkle and making construction easier. For this purpose, the optimum content is 5 to 20% of the core material sheet. Vegetable fibers include conventional asphalt such as pulp, waste paper, rag fiber, and fallen cotton. It is used as the main raw material for the core material sheet used for roofing, has good impregnability with waterproofing agents, and has high resistance to repeated loads, i.e., tension caused by vibrations or shaking behavior of buildings.
Provides properties that make it difficult to break under repeated stress of compression and bending. In addition, heat-pressing processing is because the melting point of polyethylene synthetic pulp is 90 to 140°C, so it is passed through or wrapped around a roll, cylinder, or dryer heated above the melting point, pressurized, and rolled to form a water-impermeable polyethylene layer. It is what causes it to form. It is important that this processing melt-rolls the polyethylene synthetic pulp to form an impermeable layer in which the fibers are bound and integrated. In addition, when making the core sheet using a paper machine, in order to stabilize the formation and transfer of wet paper, PV
It is advantageous to add a fibrous binder A, and other water-soluble polymeric binders can also be used. The core sheet of the present invention configured in this way is
Asphalt has excellent water impermeability, so by simply applying a thin layer of asphalt to both or one side, it can be made lightweight and highly waterproof. You can make roofing. Moreover, since the core material sheet has a shape in which each fiber is exposed on the surface, the coated asphalt adheres well, and unlike conventional metal foil or plastic sheets, there is no possibility of asphalt peeling or interlayer peeling. A highly durable product can be obtained. Therefore, the asphalt of the present invention. When constructing an asphalt waterproof layer on the roof of a building using roofing, the following effects are achieved. In the asphalt layer, multiple roofing layers, and laminated waterproof layer, the core sheet is impermeable to water, so the asphalt sandwiched between the roofing layers does not allow moisture to enter, preventing aging. It is durable and can provide excellent waterproof function over a long period of time. Since the core material sheet is water-impermeable, the covering asphalt can sufficiently perform the waterproof function even if it is thin, so it can be made lightweight. Because it is lightweight, it is extremely advantageous in terms of handling, transportation, and construction work in high places such as the roof of a building. 〓〓〓〓〓
By reducing the number and amount of laminated asphalt layers and roofing layers, a lightweight waterproof layer can sufficiently perform the waterproof function, and the recent demand for lightweight building structures can be fully met. The present invention will be further clarified by showing typical examples and comparative examples below. Example Polyethylene synthetic pulp (Mitsui Petrochemical Co., Ltd. SWP-
E, melting point 100℃) and wood pulp are thoroughly beaten and dispersed in water at 50 to 60℃, then glass fibers and PVA fibrous binder are added and mixed, and a wet paper layer is formed on a screen using a fourdrinier paper machine. form, suction dehydration and
Paper was manufactured by drying in a 100°C dryer. In the next step, the polyethylene synthetic pulp was melted and rolled by pressure and rolling using calender rolls heated to 130°C to obtain a core sheet in which the fibers were bound and integrated to form an impermeable layer. . Next is asphalt. Coating asphalt was applied to both sides of this core sheet using a roofing manufacturing machine, and one roll (21 m ² ) of 22 kg of asphalt of the present invention was produced.
Got roofing. As a result of the property tests shown in Table 2, the weight of one roll (21 m ² ) is lighter than that of the conventional product (comparative example), and the amount of asphalt covered is smaller, but the water absorption rate and water permeability are lower than that of the conventional product (comparative example). Asphalt with little
Roofing was obtained. Comparative example (conventional product) Roofing base paper manufactured by the conventional method using the core material sheet composition shown in Table 1 was impregnated and coated with asphalt to produce 35 kg as specified in JISA6006.
Asphalt that passes the quality standards. Got roofing. The property test results are shown in Table-2.

【table】

【table】

[Table] 〓〓〓〓〓

Claims (1)

[Claims] 1 Polyethylene synthetic pulp 40 with a melting point of 90-140℃
The paper made from ~60% by weight, vegetable fibers and glass fibers as the main raw materials is heat-pressed and the polyethylene synthetic pulp is melted and rolled, the fibers are bound together and integrated to form an impermeable layer. This asphalt roofing is made by using the formed sheet as a core material and applying asphalt to at least one surface of the core material sheet.