JPS6330852B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a tubular body mainly made of an inorganic curable material. Traditionally, tubular bodies made of inorganic materials such as cement have been used for drainage pipes, etc., but they have the disadvantage of poor water resistance, so the inner surface that comes into contact with water has been coated with a synthetic resin layer. It is being said. However, the adhesion between the synthetic resin layer and the inorganic material layer was not sufficient, and there was a drawback that they easily peeled off during use due to impact or other causes. The present invention has been made for the purpose of solving the above-mentioned drawbacks and providing a method for manufacturing a tubular body mainly composed of an inorganic material having excellent durability. A fibrous sheet material impregnated with a synthetic resin liquid and an inorganic binder on the other side is wrapped around a tubular object such as a paper tube so that one side is on the inside, and formed into a tube shape. The present invention relates to a method for producing a tubular body, which comprises providing a coating layer of a curable composition containing an inorganic binder as a main component on an impregnated surface and curing the coating layer. The synthetic resin liquid in the present invention includes solvent-based,
Both aqueous and water-based synthetic resin liquids can be used; solvent-based and water-based synthetic resin liquids include polyester resin liquid, unsaturated polyester resin liquid, epoxy resin liquid, acrylic resin liquid, and vinyl chloride-vinyl acetate copolymer resin liquid. Examples of water-dispersed synthetic resin liquids include acrylic resin liquid, alkyd resin liquid, vinyl acetate or vinyl acetate copolymer resin liquid, vinylidene chloride copolymer resin liquid, unsaturated polyester resin liquid, and epoxy resin liquid. , SBR latex, etc., and thermosetting resins such as epoxy resins and unsaturated polyester resins are particularly preferably used in the present invention. In addition, the inorganic binder in the present invention refers to a hydraulic inorganic binder to which water is added and hardens by heating or over time, such as gypsum, Portland cement, alumina cement, magnesia cement, or mixtures thereof. However, magnesia cement is particularly preferably used. In addition, a curable composition containing an inorganic binder as a main component is a composition in which the above-mentioned inorganic binder is used as a main component, and in addition, a fibrous reinforcing material such as short glass fibers, glass roving, or continuous glass fibers. It means a curable composition to which other additive materials are added as necessary. In the present invention, the curable composition is mixed and dispersed with the same synthetic resin liquid as that which is impregnated on one side of the fibrous sheet material to form the tube body of the inner surface synthetic resin layer of the resulting tubular body. This is preferable because it makes the bond stronger, and in that case, the amount of synthetic resin liquid added should be
The amount is preferably 5 to 50 parts by weight per 100 parts by weight. In addition, as the fibrous sheet material, woven fabrics or non-woven fabrics of inorganic fibers such as glass fibers or organic fibers such as natural or synthetic fibers are used, but non-woven fabrics are preferred from the viewpoint of impregnability with synthetic resin liquid and inorganic binder. is preferably used. The tubular body according to the present invention is manufactured by impregnating one side of the fibrous sheet with a synthetic resin liquid and the other side with an inorganic binder, and then inserting the fibrous sheet into a paper tube or the like with the one side facing inside. The curable composition is wound around a tubular object to form a tubular shape, and the curable composition is applied to the inorganic binder-impregnated outer surface of the tubular object to form a coating layer, which is then cured. For the above-mentioned curing, curing by heating is generally employed. Alternatively, the tubular object may be extracted after manufacturing the tubular object. Furthermore, in the method of the present invention, the coating layer of the curable composition may be further covered with a fibrous sheet-like material, in particular, the synthetic resin-impregnated side is on the outside and the inorganic binder-impregnated side is on the inside. By forming the outermost layer with the fibrous sheet material, it is possible to obtain a tubular body whose outer surface is also made of a synthetic resin layer firmly bonded to the tube body. Next, the method of the present invention will be explained with reference to the drawings.
1 and 2 are explanatory diagrams of the steps in the present invention. In the step shown in FIG. Impregnated sheet 21 impregnated with inorganic binder 13 by impregnation roll 16
The impregnated sheet 21 is formed into a tubular shape by winding it around a paper tube 14. Impregnated sheet 21 into paper tube 1
To form the impregnated sheet 21 into a tubular shape by winding it around the paper tube 14, both ends of the paper tube 14 are held horizontally and rotatably supported, and one end edge of the impregnated sheet 21 is attached to the paper tube 14. By rotating the paper tube 14, the impregnated sheet 21 is wrapped around the entire circumference of the paper tube 14. After winding the impregnated sheet 21 once around the outer surface of the paper tube 14, the impregnated sheet 21 is cut along one end edge of the beginning of the winding and is pressed so that the beginning of the winding and the cut edge abut against each other. FIG. 2 shows a coating layer formed by winding a curable composition mainly containing an inorganic binder, for example, a glass roving layer impregnated with an inorganic binder, on the impregnated sheet 21 formed into a tubular shape in the process of FIG. 1. 22 is shown. At this time, the method of wrapping the glass roving layer impregnated with the inorganic binder is the impregnated sheet 21.
It is done in the same way as the winding of , but it is best to make sure that the abutting portions of both layers do not overlap at the same position. A tubular body is manufactured by heating the thus obtained material to harden the synthetic resin liquid 12 and inorganic binder 13 impregnated into the fibrous sheet-like material 11 and the inorganic binder in the coating layer 22. In addition, after the tubular body is manufactured, it is generally adopted to extract the paper tube 14 from the tubular body by a conventional method such as providing a mold release agent layer on the paper tube 14 in advance. can be done. FIG. 3 is a sectional view showing an example of a tubular body manufactured according to the present invention, and shows a cured product 2 of an impregnated sheet 21.
A cured product 22' of the coating layer 22 is provided on the tubular body 1'. The inner surface of the thus obtained tubular body is composed of a synthetic resin layer, and the synthetic resin layer and the hardened layer of inorganic binder formed in contact with it are firmly adhered to each other, unlike conventional tubular bodies. The synthetic resin layer on the inner surface does not peel off easily, and the smoothness of the inner surface formed of the synthetic resin layer is also good. The method for manufacturing the tubular body of the present invention is as described above, and in particular, a fibrous sheet-like material impregnated with a synthetic resin liquid on one side and an inorganic binder on the other side is made of paper such that the above-mentioned one side is inside. It is wound around a tubular object such as a pipe and formed into a tubular shape, and a curable composition coating layer mainly composed of an inorganic binder is provided on the outer surface impregnated with an inorganic binder and this is cured, so that the inner surface of the obtained tubular body The synthetic resin coating layer is firmly bonded to the tube body and will not peel off easily like conventional products. Furthermore, if a mixed composition of an inorganic binder and a synthetic resin liquid is used as the curable composition, the water absorption and water permeability of the tubular body will be reduced, and its desirable performance as a drain pipe etc. will be improved. Examples of the present invention will be described below. In addition, in the following, parts mean parts by weight. Example 1 A magnesia cement composition consisting of 100 parts of activated magnesia, 45 parts of magnesium chloride (anhydrous salt), and 100 parts of water was used as an inorganic binder, and an unsaturated polyester resin was used as ^a synthetic resin liquid.
Impregnate one side of glass paper (glass fiber non-woven fabric) in g as shown in Figure 1, and wrap it around a 150 mm diameter paper pipe with release paper wrapped around the surface so that the inorganic binder-impregnated side faces outward. Ta. A glass roving impregnated with the above-mentioned magnesia cement composition was wrapped over it to form a coating layer. This was cured by heating at 80° C. for 1 hour, and then cured for another 21 days, and the paper tube was removed to obtain a tubular body with a wall thickness of 7 mm, an inner diameter of 150 mm, and an inner polyester coating layer thickness of 0.5 mm. The surface smoothness of the polyester coating layer on the inner surface of this tubular body was observed and the adhesion strength was tested, and the results are shown in Table 1. The adhesion strength was determined by driving a wedge-shaped object into the interface between the inner polyester coating layer and the glass roving layer impregnated with an inorganic binder and observing the state of peeling at the interface. Comparative Example 1 The same procedure was used as in Example 1, except that both sides of the glass paper in Example 1 were impregnated with the synthetic resin liquid of Example 1.
A tubular body of 150 mm and an inner polyester coating layer thickness of 1 mm was produced. The tubular body was subjected to the same test as in Example 1, and the results are shown in Table 1. Example 2 Magnesia cement composition in Example 1
Example 1 except that a curable composition prepared by mixing and dispersing 20 parts of epoxy resin in 100 parts was used as the inorganic binder, and an epoxy resin was used as the synthetic resin liquid.
A tubular body was obtained in the same manner. The test results for the tubular body are shown in Table 1. 【table】

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams of steps in the present invention, and FIG. 3 is a sectional view showing an example of a tubular body manufactured according to the present invention. 11... Fibrous sheet material, 12... Synthetic resin liquid, 13... Inorganic binder, 14... Paper tube, 15,
16... Impregnated roll, 21... Impregnated sheet, 22
...Covering layer, 21'...Cured product of impregnated sheet 21,
22': Cured product of the coating layer 22.

Claims (1)

[Claims] 1. A fibrous sheet material impregnated with a synthetic resin liquid on one side and an inorganic binder on the other side is formed into a tube shape by wrapping a tubular material such as a paper tube so that one side is on the inside. A method for manufacturing a tubular body, which comprises providing a coating layer of a curable composition mainly composed of an inorganic binder on a binder-impregnated surface and curing the coated layer.