JP2951981B2 - Sheet for coating - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a coating which can be used, for example, for anticorrosion near pipe joints for transporting fluids such as gas and water and for repairing anticorrosion layers of existing pipes. For sheet.

2. Description of the Related Art In order to perform such coating, a heat-shrinkable sheet is used so that the outer peripheral surface of a pipe can be air-tightly coated.

A typical prior art is disclosed in JP-A-56-35893. In this prior art, a heat-shrinkable sheet is wrapped around the outer periphery of a tube, and both ends in the circumferential direction in the wrapped state are partially overlapped and bonded with an adhesive. Shrink. In such prior art, the force of shearing and peeling acts due to the shrinkage force of the heat-shrinkable sheet at the time of heat shrinkage, so that the joints are peeled off by the adhesive at the time of construction, and by the residual shrinkage force after construction. In addition, the shearing and peeling forces are always exerted, and the durability is inferior especially when used under high temperature conditions.

Another prior art is disclosed in JP-A-60-34829.
In this prior art, pins are inserted into both ends of the heat-shrinkable sheet and joined. Another prior art is disclosed in Japanese Utility Model Laid-Open No. 57-44293. In this prior art, a large number of fine loops are implanted at one end of the heat-shrinkable sheet, and a large number of hooks hooked on the loop are implanted at the other end. Perform bonding. In each such prior art,
The joint structure is relatively complicated, the productivity is poor, and the joint may be damaged when an excessive bending force is applied and when an excessive tightening force is applied. In addition, there is a problem that the bonding strength is insufficient, and thus the stress at the time of shrinkage of the heat-shrinkable sheet is reduced, so that the sealing property is reduced.

Still other prior art is disclosed in JP-A-57-120417 and JP-A-61-274198. In these prior arts, both ends of a heat-shrinkable sheet are sandwiched and fixed by metal fittings. In such prior art as well, the structure is relatively complicated, and the metal fittings may be damaged by excessive bending force and tightening force, and the sealing property may be reduced due to stress relaxation.

Problems to be Solved by the Invention It is an object of the present invention to provide a covering sheet capable of reliably covering a heat-shrinkable sheet on an object such as a tube.

Means for Solving the Problems The present invention provides a flexible sheet main body, at least a part of which is made of a crosslinked polymer uniaxially stretched in the longitudinal direction, and one surface of one end of the sheet main body in the longitudinal direction. When,
A pair of locking portions respectively formed on the other surface of the other end portion and locking each other, wherein the locking portion is perpendicular to the longitudinal direction of the seat body and inclined inward in the longitudinal direction and has a thickness. A first locking surface extending in the direction;
A covering sheet comprising: a second locking surface outside the first locking surface and extending in the thickness direction; and a raised surface that connects tips of the two locking surfaces.

Further, the present invention is characterized in that the angle between the surface of the seat body and the first locking surface is 30 to 80 °.

Further, the present invention is characterized in that an adhesive is applied to the surface of the locking portion, and the locking portion has a height equal to or greater than the thickness of the adhesive layer.

The covering sheet according to the present invention comprises a flexible sheet body,
The flexible sheet body has a pair of locking portions, at least a part of the flexible sheet body is made of a crosslinked polymer uniaxially stretched in the longitudinal direction, and each of the pair of locking portions is in the longitudinal direction of the sheet body. A first surface is formed on one surface of one end and the other surface of the other end, and extends in the thickness direction perpendicular to the longitudinal direction of the sheet body and inclined inward in the longitudinal direction.
A locking surface, a second locking surface outside the first locking surface and extending in the thickness direction, and a raised surface connecting the tips of the two locking surfaces can be locked to each other. . Therefore, when the flexible sheet body is wound almost once around the object to be covered, for example, the outer peripheral surface of the tube, and the pair of locking portions are locked to each other, the locking portions have the above-described configuration. In the state where the flexible sheet body is wound around the outer circumference of the pipe,
The locking of the locking portion does not come off. Thereafter, the uniaxially stretched crosslinked polymer is heated to cause heat shrinkage. In this way, the flexible sheet main body can be wound around the outer peripheral surface of the tube and covered.

Further, according to the present invention, the first locking surface extends in the thickness direction at an angle of 30 to 80 ° with the surface of the seat body, so that a so-called return projection is formed. Therefore, even if the flexible sheet main body contracts while being wound on the outer peripheral surface of the tube, the locked state is securely maintained.

According to the present invention, the surface of the locking portion is coated with an adhesive, so that the locking portion is also fixed by the adhesive, and the locking portion is larger than the thickness of the adhesive layer. , The pair of locking portions can be reliably locked to each other.

Embodiment FIG. 1 is a perspective view of one embodiment of the present invention. The covering sheet 1 has an elongated flexible sheet main body 2 extending in the longitudinal direction (left-right direction in FIG. 1), and a pair of locking portions formed at both longitudinal ends of the sheet main body 2.
5 and 6, and is made of a crosslinked polymer uniaxially stretched in the longitudinal direction (the left-right direction in FIG. 1), such as crosslinked polyethylene, crosslinked polypropylene, crosslinked fluororubber, fluororesin, and crosslinked silicone rubber. The thickness of the sheet body 2 is, for example, 1 to 3 mm. One locking portion 5 is one end in the longitudinal direction of the seat body 2 (the right end in FIG. 1).
Are formed so as to protrude from one surface (the lower surface in FIG. 1), and a plurality (three in this embodiment) are formed at intervals in the longitudinal direction. Another locking portion 6 is the seat body 2
Of the other end (the left end in FIG. 1) is formed to protrude on the other surface (the upper surface in FIG. 1), extends in the width direction, and is the same as the one locking portion 5 (this embodiment). In the example, 3) or one that is inward when locked is formed one less.

One of the locking portions 5 is perpendicular to the longitudinal direction of the seat body 2 and is inclined inward in the longitudinal direction so as to have an angle of less than 90 °, preferably 30 to 80 ° in the thickness direction (vertical direction in FIG. 1). It has a first locking surface 5a extending, a second locking surface 5c outside the first locking surface 5a and extending in the thickness direction, and a raised surface 5b connecting the tips of the locking surfaces 5a, 5c. The other locking portion 6 has the same configuration. An adhesive 7 is applied to a surface near one of the locking portions 5 over a distance 1 in the longitudinal direction.
The height t2 of the locking portion 5 is larger than the thickness t1 of the layer of the adhesive 7. Thereby, the pair of locking portions 5 and 6 are locked to face each other via the adhesive 7. The height t2 of the locking portion 5 is preferably 0.5 to 2 times the thickness t3 of the seat body 2.

Thus, when the sheet body 2 is formed in a cylindrical shape, the locking of the pair of locking portions 5 and 6 is not released even if the sheet body 2 expands and contracts in the longitudinal direction. Furthermore, the first locking surface 5a
Θ1 between the ridge and the raised surface 5b is less than 90 °, preferably
30-80 °. When the angle θ1 is less than 90 °, when the sheet body 2 is coated on a curved surface such as a tube, the locking of the pair of locking portions 5 and 6 is reliably maintained.

FIG. 2 is a sectional view showing a procedure of a coating method for coating a pipe 10 such as a steel plate for transporting a fluid using the coating sheet 1 shown in FIG. Referring to FIG. 2 (1),
A coating layer 15 is formed on the tube 10 in advance, and an adhesive 16 is applied to a portion 10a of the tube 10 to be coated.
The joining operation of the both ends 3 and 4 of the sheet main body 2 is performed at a position shifted from the portion 10a of the tube 10 to be covered to the left in the axial direction in FIG. FIG. 2 (2) is a cross-sectional view taken along line II-II of FIG. 2 (1). The tube 10 is covered with the sheet body 2 and its ends 3, 4 are overlapped so that the locking portions 5, 6 are locked via the layer of the adhesive 7. FIG. 3 shows the locking portion.
FIG. 5 is an enlarged cross-sectional view showing a state where 5 and 6 are locked via a layer of an adhesive 7 and are bonded by the adhesive 7. In this case, the inner diameter of the cylindrical sheet body 2 is
The gap 12 is larger than the outer diameter of.

Therefore, the flat electric heaters 13 and 14 having flexibility are pressed against the ends 3 and 4 of the sheet body 2 in this manner, and the ends 3 and 4 are heated so that the sheet body 2 is partially The heat-shrinkage is performed so that the locking portions 5 and 6 are locked, and are bonded by the adhesive 7.

The adhesive 7 may be a thermoplastic synthetic resin material which is fluid when heated, solidifies when the temperature of the fluid is transported in the tube 10 or lower, or becomes tacky, or once heated. A thermosetting synthetic resin material or the like which reacts and cures although the viscosity decreases may be used.

Specific examples of such an adhesive 7 include butyl rubber, epoxy resin, and unsaturated polyester resin.

Then, the electric heaters 13 and 14 are removed, the cylindrical sheet body 2 is moved to the portion 10a to be covered, and the burner 17 is used to move the end 3 of the sheet body 2 as shown in FIG. ,
The remaining portion other than 4 is heated, and thus the sheet body 2 is thermally contracted. As a result, the adhesive 16 is applied to the outer peripheral surface of the pipe 10.
, The sheet body 2 is covered. The adhesive 16 may be omitted.

FIG. 4 is a perspective view of a covering sheet 20 according to another embodiment of the present invention. This covering sheet 20 has a configuration similar to that of the covering sheet 1 shown in FIG. 1 described above, and corresponding portions are denoted by the same reference numerals. In this embodiment, it should be noted that the adhesive 7 is applied over the entire surface of the sheet body 2 where the locking portion 5 is formed.

In covering the pipe 10 using the covering sheet 20 shown in FIG. 4, the ends 3, 4 of the sheet body 2 are overlapped and locked as shown in FIG. 5 (1). In this state, a rigid metal plate 21 made of a material such as iron is applied to the outer peripheral surface of the end portion 4 and heated by the burner 22. As a result, the locking portions 5 and 6 are adhered in a formed state.

Thereafter, as shown in FIG.
Is used to heat the remaining part of the sheet body 2 to thermally shrink it. Thereby, the coating is performed in a state where the adhesive 7 is filled between the outer peripheral surface of the tube 10 and the inner peripheral surface of the tubular sheet body 2.

FIG. 6 is a side view of another embodiment of the present invention. In this embodiment, the portions of the lengths l2 and l3 of the ends 3 and 4 of the sheet body 2 do not have heat shrinkage, and the portions extending over the remaining length l4 have heat shrinkage. The portion having no heat shrinkage over the lengths l2 and l3 of the ends 3 and 4 is shrunk in advance by heating the crosslinked polymer uniaxially stretched in the longitudinal direction (the left-right direction in FIG. 6). Or, it is formed into a sheet without stretching.

FIG. 7 is a sectional view of another embodiment of the present invention. In this embodiment, the end portions 3 and 4 of the seat body 2 have one locking portion.
As shown in FIG. 8, the locking portions 5 and 6 are locked, and are bonded through a layer of the adhesive 7 as shown in FIG.

FIG. 9 is a sectional view of still another embodiment of the present invention. This embodiment is similar to the embodiment of FIGS. 7 and 8 described above, and corresponding parts are denoted by the same reference numerals. It should be noted that, in this embodiment, a layer of the adhesive 7 is formed not only near the end portion 5 but also on the entire surface of the sheet body 2 where the locking portion 5 is formed.

Advantageous Effects of the Invention As described above, according to the present invention, at least a portion of the flexible sheet body in the longitudinal direction is made of a crosslinked polymer uniaxially stretched in the longitudinal direction, and this sheet body is formed into an object such as a tube. The sheet is wound substantially once so that a pair of locking portions formed on one surface of one end of the sheet body in the longitudinal direction and the other surface of the other end of the sheet body are mutually locked, and the crosslinked polymer is heated. As a result, the sheet body can be thermally adhered to the surface of an object such as a tube so as to be closely adhered to the surface of the object. Therefore, the joining of the both ends in the longitudinal direction of the seat body at the locking portion is ensured, and the durability is easily improved. The locking portion,
A first locking surface extending in the thickness direction perpendicular to the longitudinal direction and inclined inward in the longitudinal direction; a second locking surface outside the first locking surface and extending in the thickness direction; Since it has a configuration including a raised surface connecting the tips of the two locking surfaces, or a configuration including a locking recess and a locking projection fitted into the locking recess, the pair of locking portions can be locked to each other. For example, when the cylindrical covering sheet is formed, the locking of the locking portion does not come off. Furthermore, it can be easily produced, and the surface of the object can be covered with the sheet body in close contact for a long period of time, whereby long-term corrosion protection can be achieved.

In particular, according to the present invention, the first locking surface is inclined with respect to the surface of the seat body at an angle of 30 to 90 °, and the first locking surfaces come into contact with each other to achieve the locked state. Therefore, even when the sheet main body is wound around the curved surface of the outer peripheral surface of the tube or the like, the locked state in which the locking surface abuts is reliably maintained. An adhesive may be applied to the locking portion to improve the bonding strength at both ends of the sheet body.

In this way, a durable bond is achieved even when shearing and peeling forces act on the locking portion. In addition, it does not require pins and the like in the prior art, has a simple configuration, and therefore has excellent productivity, and can reduce manufacturing costs.

Further, in the present invention, large projections such as metal fittings for fixing both ends of the sheet body in the prior art described above do not protrude from the surface of the coating layer in the present invention. No damage is caused, and the coated state can be reliably maintained for a long period of time.

Even if the environment is high temperature, the locked state of the pair of locking portions is maintained, and the locked state does not come off even during long-term shear creep due to residual stress of the sheet body, and the seat body does not come off. Is securely maintained at both ends.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of the present invention, FIG. 2 is a cross-sectional view showing a method of coating a pipe 10 using the coating sheet 1 shown in FIG. 1, and FIG. End 3 and 4 locking parts
FIG. 4 is a cross-sectional view showing a state in which 5 and 6 are locked and fixed and joined by a layer of an adhesive 7, FIG. 4 is a perspective view of another embodiment of the present invention, and FIG. FIG. 6 is a cross-sectional view showing an operation of coating the pipe 10 using the coating sheet 20 shown, FIG. 6 is a cross-sectional view of another embodiment of the present invention, and FIG. 7 is a cross-sectional view of still another embodiment of the present invention. FIG. 8 is a cross-sectional view showing a state in which the locking portions 5, 6 of the covering sheet shown in FIG. 7 are bonded and bonded via a layer of an adhesive 7, and FIG. 9 is a view showing the present invention. It is sectional drawing of other Example of a. 1,20 ... Coating sheet, 2 ... Sheet body, 3,4 ... End, 5,6 ... Locking part, 5a, 5c, 6a, 6c ... Locking surface, 7 ... Adhesive

Claims (3)

(57) [Claims] 1. A flexible sheet main body at least part of which is made of a crosslinked polymer uniaxially stretched in the longitudinal direction, one surface of one end in the longitudinal direction of the sheet main body, and one end of the other end of the sheet main body. A pair of locking portions respectively formed on the other surface and locking each other, wherein the locking portion extends in the thickness direction perpendicularly to the longitudinal direction of the seat body and inclining inward in the longitudinal direction. A covering sheet comprising: a first locking surface, a second locking surface outside the first locking surface and extending in the thickness direction, and a raised surface connecting the tips of the two locking surfaces. . 2. An apparatus according to claim 1, wherein the angle formed between the surface of the seat body and the first locking surface is 30 to 80 °.
The sheet for covering according to item. 3. The locking portion according to claim 1, wherein an adhesive is applied to a surface of the locking portion, and the locking portion has a height greater than a thickness of the adhesive layer. The sheet for covering according to the above.