JP2017101779A - Protection method for gas piping facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily prevent gas leakage to enable gas leakage to stop, in a gas piping facility on which external force such as vibration is easy to act.SOLUTION: On an outer peripheral part of a gas piping facility, coated is a photocurable resin composition obtained by mixing: at least one kind of urethane(meth)acrylate oligomer of 40-90 pts.mass; at least one kind of (meth)acrylate monomer 60-10 pts.mass; and titanocene-based polymerization initiator of 0.5-2.5 pts.mass based on a total amount of the urethane(meth)acrylate oligomer and (meth)acrylate monomer of 100 pts.mass, to thereby form a coating part 30, and then light is radiated to the coating part 30 to subject the photocurable resin composition to hardening reaction, to thereby form a protective part on the outer peripheral part of the gas piping facility.SELECTED DRAWING: Figure 2

Description

  The present invention is, for example, a flexible piping facility for gas composed of flexible piping, a joint portion thereof, or the like, or a general galvanized steel pipe (common name: white gas pipe) (general screw joint gas piping) on which vibration or external force acts, In general gas piping equipment consisting of such joints, etc., and gas piping equipment including mechanical joints used in places where large gas pipe elongation is required due to fluctuations in ground subsidence, etc., gas leakage is prevented or prevented. The present invention relates to a method for protecting gas piping equipment.

Generally, when supplying city gas or liquefied petroleum gas to customers, as an example of gas piping equipment, flexible piping as one of gas conduits, galvanized steel pipe used as general piping (commonly called white) Gas pipes), mechanical joints used in places that require large gas pipe elongation due to fluctuations in the ground, etc. are used in residential buildings.
Flexible piping, especially in gas flexible piping equipment that supports residential construction methods such as the prefabricated construction method and the two-by-four construction method, is different from conventional piping equipment that uses screw joints, and piping construction in a narrow space and a short construction period It is effective for the construction requirements of the company.
The flexible piping facility for gas is a facility in which a stainless steel plate is processed into a corrugated plate, and a pipe covered with a resin such as polyvinyl chloride is piped through a joint portion or the like.
And the thickness of the stainless steel plate is 0.2mm to 0.25mm, and the extremely thin steel plate is used. The flexible pipe is passed through the wall of the building. However, the position of the flexible pipe inside the wall is not accurately known, and there are cases where nails are struck on the flexible pipe and a hole is made, so that a hole is generated and gas is leaked from the flexible pipe. May occur.
However, development of a technique for detecting a gas leak from a flexible piping facility for gas has been performed, but a repair method has not been developed (Patent Documents 1 and 2).
In other words, since the flexible pipe for gas can be bent freely, the minimum bending radius is determined, and in order to prevent gas leakage when bent at this minimum radius, in a hard cured product such as an epoxy resin, This is because it was not possible to cope (Non-Patent Document 1).

Moreover, in the case of a galvanized steel pipe (common name: white gas pipe) joint, in the case of a steel pipe, a method of curing an epoxy acrylate resin has been proposed as a repair method for gas leakage from a screw portion or the like (Patent Document 3). 4), and a repair method using an aqueous emulsion resin has also been proposed, but in the case of extremely low temperatures in the Hokkaido region, the emulsion resin freezes and cannot be used. Since it is vaporized to form a film, extremely time is required, curing failure occurs, gas leakage may not stop, and it cannot be used constantly.
In addition, water-based emulsion resin contains a small amount of water-soluble solvent such as alcohol, and since these are contained in the coating film for a long time, it reacts with the gas detector and causes gas leakage. It was not possible to determine whether the residual solvent was present or not, and workability was poor (Patent Document 5).
Moreover, in the case of flexible piping equipment, because flexible piping is easy to move, phenomena such as pulling and bending are likely to occur, adhesion and high elongation are required, and conventional methods using epoxy acrylate are too hard. , Did not follow, caused peeling and could not stop the gas leak.

  In the case of another conventional method of winding with self-adhesive tape, the tape wound by self-shrinking may be integrated, but the adhesion with the gas pipe to be protected is flexible piping. However, since it has a corrugated corrugated structure, it cannot be completely adhered to the periphery of the cleaved hole, and it is difficult to stop gas leakage.

  As the gas piping facility, in addition to the flexible piping facility for gas, the general galvanized steel pipe (common name: white gas pipe) (general threaded joint gas piping) and the general gas piping facility composed of the joint portion thereof, in particular, For example, in a gas cogeneration piping facility or the like on which vibration or external force acts, gas leakage may occur based on the vibration, similarly to the above flexible piping facility. However, since an external force such as vibration acts, the leakage gas cannot be stopped, and there is no protection method suitable for this case.

Mechanical joints are joints designed so that the gas pipe expands and contracts due to ground subsidence, etc., but the expansion of the piping causes loosening of the packing inside the mechanical joint, causing gas leakage from the gap. There are many cases.
Thus, it was not possible to stop the leakage of gas from the mechanical joint on the assumption that such a large displacement of the gas pipe occurred, and there was no protection method suitable for this case.

JP 10-318873 A JP-A-10-132149 JP 2011-67999 A JP 2011-134470 A JP 2002-249760 A

Stainless steel flexible pipe for gas (flexible pipe) Hitachi Metals, Ltd. Trade name Soflex Catalog

  Accordingly, an object of the present invention is to eliminate the above-mentioned problems and to easily prevent gas leakage or to stop gas leakage in a gas piping facility in which external force such as vibration is likely to act. Is to provide protection methods.

  The first characteristic configuration of the present invention is that at least one urethane (meth) acrylate oligomer 40 to 90 parts by mass, at least one (meth) acrylate monomer 60 to 10 parts by mass, A photocurable resin composition in which 0.5 to 2.5 parts by mass of a titanocene polymerization initiator is mixed with 100 parts by mass of the total amount of urethane (meth) acrylate oligomer and (meth) acrylate monomer component is applied. A covering portion is formed, and the covering portion is irradiated with light to cause the photocurable resin composition to cure and form a protective layer on the outer peripheral portion of the gas piping facility.

According to the first characteristic configuration of the present invention, the gas curable resin composition is applied to the outside of the gas piping facility to form the covering portion, so that, for example, a flexible gas can be used regardless of the diameter or type of the piping. On the outer periphery of gas piping equipment such as piping, at least one urethane (meth) acrylate oligomer 40 to 90 parts by mass, at least one (meth) acrylate monomer 60 to 10 parts by mass, and urethane (meth) acrylate A coating part is formed by applying a photocurable resin composition in which 0.5 to 2.5 parts by mass of a titanocene polymerization initiator is mixed with respect to 100 parts by mass of the total amount of the oligomer and the (meth) acrylate monomer component, By irradiating the coating part with light and curing reaction of the photocurable resin composition to form a protective layer on the outer periphery of the gas piping equipment, it can be applied to nailing and cutter scratches, etc. It is possible to cover a gas piping facility that is more likely to leak gas.
In addition, a covering portion can be easily formed even in a narrow work space, and the covering portion is made of a photocurable resin composition that is irradiated with light to cause a curing reaction. It can be formed and can prevent and prevent gas leakage as well as anticorrosive action.

  In a second characteristic configuration of the present invention, the titanocene polymerization initiator is bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium.

  According to the 2nd characteristic structure of this invention, a photocurable resin composition can be hardened in a short time.

  As for the 3rd characteristic structure of this invention, the said photocurable resin composition hardened | cured material has a glass transition point of -30 degreeC-50 degreeC.

The photocurable resin composition cured product of the third characteristic configuration of the present invention has a glass transition point of −30 ° C. to 50 ° C. if the glass transition point is less than −30 ° C. It is too soft, and after curing, the strength to stop the gas is insufficient, causing gas leakage.
Further, if the glass transition point is higher than 50 ° C., peeling occurs at a low temperature such as midwinter and gas leakage occurs. Therefore, the cured product of the photocurable resin composition has a glass transition point of −30 ° C. to 50 ° C.

  The 4th characteristic structure of this invention exists in the said photocurable resin composition hardened | cured material having the breaking elongation of 30%-300%.

The cured product of the photocurable resin composition according to the fourth characteristic configuration of the present invention has a breaking elongation of 30% to 300%. If the breaking elongation is less than 30%, it is too hard. Thus, for example, the gas does not follow the bending work during the work of the flexible pipe for gas and peels off to generate a gas leak.
Further, if the breaking elongation is 300% or more, it is too soft, the strength is insufficient, and gas leakage occurs.

  The 5th characteristic structure of this invention exists in the place which adjusted the viscosity of the said photocurable resin composition to the range of 10,000-60,000 mPa * s at 25 degreeC.

According to the fifth characteristic configuration of the present invention, the photocurable resin composition having the above viscosity is surely strong and hardened in a situation where a leakage point of piping equipment through which gas flows must be quickly stopped. Can be formed to stop gas leakage.
That is, if the viscosity of the photocurable resin composition is lower than 10,000 mPa · s, it is difficult to form a strong film because of its fluidity and cannot be stopped in a short time. If it is higher than 60,000 mPa · s, the fluidity is lost, it cannot be applied to the leaked part, and the gas leakage cannot be stopped in a short time due to poor adhesion to the surface of the pipe.

  The 6th characteristic structure of this invention exists in the place which adjusted the wavelength of the light which the said photocurable resin composition hardens | cures to 400-700 nm.

  According to the sixth characteristic configuration of the present invention, examples of the light that cures the photocurable resin composition include ultraviolet light, visible light, and laser light, and the wavelength of light is 150 nm to 800 nm. However, 400 nm to 700 nm is particularly preferable.

  According to a seventh characteristic configuration of the present invention, the gas piping facility is a gas flexible piping facility, and after the curing reaction of the photocurable resin composition, the flexible piping is bent at a predetermined bending radius to cause gas leakage. It is to confirm the presence or absence.

According to the seventh characteristic configuration of the present invention, the photocurable resin composition has high flexibility, and when the flexible pipe is bent at a predetermined bending radius, the photocurable resin composition is closely attached to the flexible pipe and has high elongation. The gas leakage can be stopped without peeling, and the reliability of the protective function by the protective layer can be improved by checking the presence or absence of the gas leakage.
For example, the bending radius (inner radius) of the predetermined flexible pipe is 20 mm for the diameters 8A, 10A, and 15A, and 25 mm for the diameter 20A. In the case of the aperture 25A, it is 30 mm. In the case of the aperture 30A, it is 40 mm.
Bending with this determined bending radius, after repairing, it is possible to ensure safety by confirming that no gas leakage occurs again.

  In an eighth characteristic configuration of the present invention, the gas piping facility is a mechanical joint for gas piping.

  According to the eighth characteristic configuration of the present invention, even if there is a gas leakage phenomenon that occurs due to vibration or tensile force acting on the mechanical joint, the protective layer can be expanded and contracted with flexibility to prevent gas leakage. In addition to being able to prevent, it can maintain gas leakage prevention performance.

  According to a ninth characteristic configuration of the present invention, the covering portion covers a gas leak point of a gas piping facility, and the covering portion is wound tightly while pulling a transparent resin film around the surface of the covering portion. The photocurable resin composition is irradiated with light from the outside of the transparent resin film in a state where gas leak detection means confirms that no gas leaks through the transparent resin film while maintaining the airtightness of the photocurable resin composition. The protective layer is formed by curing the product.

According to the ninth characteristic configuration of the present invention, before the coating portion is irradiated with light, the surface of the coating portion is covered with a transparent resin film to maintain the airtightness of the coating portion. The resin composition is capable of forming a cured product having a non-adhesive surface by a rapid reaction without blocking air and preventing polymerization curing by oxygen in the air.
In addition, by covering the uncured coating with a transparent resin film, even if there is a gas leakage phenomenon that tries to leak from the leaking part during curing of the coating, the gas flow path is covered by suppressing the gas pressure. Can be prevented from being formed in the part, by continuously irradiating light from the outside of the transparent resin film to cause a curing reaction of the photocurable resin composition, without forming a gas leakage flow path in the covering part, A protective layer capable of preventing complete gas leakage can be formed.
Therefore, since gas leakage at the gas piping is prevented and gas leakage at the time of gas flow is stopped with a transparent resin film, the gas leak repair can be performed quickly and easily when the gas is flowing. . In addition, even a flexible gas piping having a complicated shape can be easily covered with a transparent resin film, and the gas piping equipment can be protected easily and inexpensively.

  According to a tenth characteristic configuration of the present invention, the transparent resin film is any one of the transparent uncolored polyethylene film, the transparent PVC film, or the transparent PVC tape, and is peeled after the photocurable resin composition is cured. It is a protection method.

According to the tenth characteristic configuration of the present invention, as the transparent resin film, a polyolefin resin film such as polyethylene and polypropylene and a vinylidene chloride or vinyl chloride resin film are used, but an appropriate elongation and strength are required. Therefore, preferably, by covering the uncured coating portion with a transparent uncolored polyethylene film, a transparent polyvinyl chloride film or a transparent polyvinyl chloride tape, there is a gas leakage phenomenon that tends to leak from the screw joint portion during the curing of the coating portion. However, it is possible to prevent the gas flow path from being formed in the covering portion by suppressing the gas pressure, and then irradiate light from the outside of the transparent uncolored polyethylene film, the transparent polyvinyl chloride film or the transparent polyvinyl chloride tape. By curing the resin composition, complete gas leakage without forming a gas leakage channel in the coating Possible to form a protective layer can be prevented.
Therefore, not only gas leakage prevention of gas piping equipment but also gas leakage stop work at the time of gas leakage can be performed easily and quickly. In addition, the flexible piping for gas with complex shapes, its joints, or mechanical joints can be easily covered with transparent uncolored polyethylene film, transparent PVC film or transparent PVC tape, and gas piping is simple and inexpensive. Equipment can be protected.

  According to an eleventh characteristic configuration of the present invention, the covering portion covers a gas leakable portion of the gas piping facility.

  According to the eleventh characteristic configuration of the present invention, by covering the gas leakable portion of the gas piping facility with the covering portion, even when gas is flowing in the gas piping or when it is not flowing However, regardless of the presence or absence of a gas leak location, the covering portion prevents gas leak prevention, and the gas piping equipment can be used for a longer time.

It is the partial longitudinal cross-sectional view which expanded the principal part of flexible piping. It is action explanatory drawing which shows the protection procedure with respect to the gas leak location of flexible piping, (a) is a partial cross section figure of the opening part of a gas leak, (b) is a partially notched longitudinal cross section figure of the state which peeled off the coating partially (C) is a partially cutaway longitudinal sectional view in which a covering portion is formed in the opening, and (d) is a partially cutaway longitudinal sectional view of a state in which light is applied to the covering portion. It is a partially longitudinal explanatory view showing a bending test of a flexible pipe, (a) is a state before bending the flexible pipe, (b) is a state where the flexible pipe is bent. It is explanatory drawing which shows the protection method in the connection part of a galvanized steel pipe (common name: white gas pipe) and a mechanical coupling, (a) irradiates light after formation of a coating | coated part, (b) irradiates light after formation of a coating | coated part. In the state, (c) is a front view of a state in which a tensile test is relatively performed in the direction of the arrow on the clamp portion between the mechanical joint and the white gas pipe after the coating portion is cured. It is operation | movement explanatory drawing which shows the protection procedure with respect to the gas leak location of the flexible piping in a live pipe state, (a) is a partial sectional view of the opening part of a gas leak, (b) is a part of the state which peeled off part of coating | covering Cutaway longitudinal cross-sectional view, (c) is a cross-sectional view of the main part in a state where a cover is formed on the opening and then covered with a transparent resin film on the outside of the cover, (d) is a cover from the outside of the transparent resin film It is a partially cutaway longitudinal cross-sectional view of the state which irradiates light.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1 as an example, the gas piping facility according to the present invention is a flexible piping in which a stainless steel plate is processed into a corrugated plate to form a bellows shape, and the outer periphery thereof is covered with a resin coating 40 such as vinyl chloride. 10 is a facility in which piping is constructed using a joint such as a one-touch joint.
And the thickness of a stainless steel plate is 0.2 mm to 0.25 mm, uses the very thin steel plate, and has passed the flexible piping 10 in the wall of the building.

As a method of protecting the flexible piping facility for gas, as shown in FIGS. 2A to 2D, in order to prevent gas leakage from the gas leakage hole (opening 20) formed in the flexible piping 10 ( For the experiment, a hole of about 1 mm is drilled in the gas flexible pipe 1 (FIGS. 2A and 2B)), and the photocurable resin composition is provided in the gas leakage hole (opening 20). Is applied to form a covering portion 30 (FIG. 2C), and the covering portion 30 is irradiated with light such as an LED light 50 to cause the photocurable resin composition to undergo a curing reaction to form a protective layer ( FIG. 2 (d)).
Further, as shown in FIGS. 5A to 5D, when repairing is performed in the state of gas flow (live tube state), the covering 40 before and after the opening 20 is cut off (FIG. 5 ( a) → FIG. 5 (b)), as shown in FIG. 5 (c), a photocurable resin composition is applied to form a covering portion 30, and a transparent uncolored polyethylene film, a transparent PVC film, or a transparent PVC tape is formed. The transparent resin film 90 is wound while being pulled so as to be able to apply a pressure, and once gas leakage is stopped, as shown in FIG. 5 (d), the LED light is passed through the transparent resin film 90 to the covering portion 30. 50 or the like is irradiated to cure the photocurable resin composition to form a protective layer, and then the transparent resin film 90 is removed.
Needless to say, the protection method is not limited to repairing the flexible pipe 1 but can be used for repairing a gas leak hole of a general galvanized steel pipe (common name: white gas pipe).
In addition, after the protective layer is formed, as shown in FIG. 3, the bending radius (inner radius) of the assumed flexible pipe 10 is centered around the point where the gas leakage repair is made outside and the gas leakage is repaired. ) B bent at R to detect gas leakage (FIG. 3 (a) → (b)).

As another example, as shown in FIG. 4, the gas piping facility is a screw joint piping facility called a general galvanized steel pipe (common name: white gas pipe) facility having a mechanical joint 60 (FIG. 4A). ), A photocurable resin is applied to a connection portion between the mechanical joint 60 on which a relative tensile force acts and a galvanized steel pipe (common name: white gas pipe) 70 to form the covering portion 30.
After the coating portion 30 is irradiated with light by the LED light 50 to cause a curing reaction (FIG. 4 (b)), as shown in FIG. 4 (c), a galvanized steel pipe (common name: white) is applied to the mechanical joint 60. The gas pipe 70 is grasped and pulled by the clamp portion 80 to inspect for gas leakage.

The photocurable resin composition comprises at least one urethane (meth) acrylate oligomer 40 to 90 parts by mass, at least one (meth) acrylate monomer 60 to 10 parts by mass, and a urethane (meth) acrylate oligomer. And 0.5 to 2.5 parts by mass of a titanocene polymerization initiator with respect to 100 parts by mass of the total amount of the (meth) acrylate monomer components.
The urethane (meth) acrylate oligomer used in the present invention is not particularly limited as long as it is a urethane (meth) acrylate, and, for example, a (meth) acrylate monomer having a polyisocyanate compound, a polyol compound, and active hydrogen, It is obtained by the reaction of
The urethane (meth) acrylate used in the present invention is preferably a urethane (meth) acrylate or aliphatic urethane having a polyether as a main skeleton from the viewpoint of obtaining a cured product having flexibility and excellent extensibility. And (meth) acrylate.

  Examples of the polyisocyanate compound include aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate. Among these, from the viewpoint of obtaining a cured product having flexibility and excellent extensibility, aliphatic polyisocyanate, Alicyclic polyisocyanates are preferred.

  Examples of the aliphatic polyisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, heptamethylene diisocyanate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4- or 2,4,4-trimethylhexa Methylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, 2,6-diisocyanatoethylcaproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, etc. It is done. These are used alone or in combination.

  Examples of the alicyclic polyisocyanate include isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, and bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-di. Examples thereof include carboxylate and 2,5- or 2,6-norbornane diisocyanate. These are used alone or in combination.

  Examples of the polyol compound include compounds having two or more active hydroxyl groups in the molecule. For example, polyether polyol, polyester polyol, polycarbonate diol, polybutadiene polyol, hydrogenated polybutadiene polyol, polylactone polyol, castor oil type Examples include polyols, hydrogenated castor oil-based polyols, polyisoprene polyols, hydrogenated polyisoprene polyols, and the like. These can be used alone or in combination.

  Examples of the (meth) acrylate monomer having active hydrogen include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, ethylene glycol mono (meth) acrylate, and propylene glycol mono (meth) acrylate. 2-hydroxy-3-methoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, N-methylolacrylamide or methacrylamide, N-hydroxyacrylamide or methacrylamide, and the like. These can be used alone or in combination.

  In the present invention, the blending ratio of the components is not particularly limited, but the urethane (meth) acrylate oligomer is 40 to 90 parts by mass, and at least one (meth) acrylate monomer is 60 to 10 parts by mass, and urethane If the (meth) acrylate oligomer is less than 40 parts by mass, the flexibility tends to be lost, and if it is 90 parts by mass or more, the viscosity is too high and is difficult to work.

  Moreover, in the synthesis | combination of a urethane (meth) acrylate oligomer component, solvents and catalysts, such as ethyl acetate, toluene, and xylene, are used as needed. Examples of the catalyst include titanium-based catalysts such as lead oleate, tetrabutyltin, antimony trichloride, triphenylaluminum, trioctylaluminum, dibutyltin dilaurate, titanium alkoxide, copper naphthenate, zinc naphthenate, zinc octylate, octenoic acid Zinc, zirconium naphthenate, cobalt naphthenate, tetra-n-butyl-1,3-diacetyloxydistanoxane, triethylamine, 1,4-diaza [2,2,2] bicyclooctane, N-ethylmorpholine, etc. Among them, dibutyltin dilaurate, zinc naphthenate, zinc octylate, and zinc octenoate are preferably used because of their high activity.

The weight average molecular weight of the urethane (meth) acrylate oligomer component of the present invention is preferably in the range of 500 to 100,000, more preferably in the range of 1,000 to 70,000, and particularly preferably 2, It is in the range of 000 to 50,000.
That is, if the weight average molecular weight is less than 500, the cured product may be inferior in extensibility. If the weight average molecular weight exceeds 100,000, the viscosity of the photocurable resin composition increases and the workability is improved. May be inferior.
In addition, in this specification, a weight average molecular weight means the weight average molecular weight of polystyrene conversion measured by gel permeation chromatography.

Specific examples of monofunctional acrylic monomers that can be used as the (meth) acrylate monomer include lauryl acrylate, stearyl acrylate, tetrahydrofurfuryl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, and isobornyl. Acrylate, benzyl acrylate, phenyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, nonylphenoxyethyl acrylate, nonylphenoxytetraethylene glycol acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, butoxyethyl acetate Chryrate, butoxytriethylene glycol acrylate, 2-ethylhexyl polyethylene glycol acrylate, nonylphenyl polypropylene glycol acrylate, methoxydipropylene glycol acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycerol acrylate, polyethylene glycol acrylate, polypropylene Glycol acrylate, epichlorohydrin (hereinafter abbreviated as ECH) modified butyl acrylate, ECH modified phenoxy acrylate, ethylene oxide (hereinafter abbreviated as EO) modified phthalic acid acrylate, EO modified succinic acid acrylate, caprolactone modified 2-hydroxyethyl acrylate, N , N-dimethylaminoethyl Acrylate, N, N-diethylaminoethyl acrylate, morpholinoethyl acrylate, but EO-modified phosphoric acid acrylate and the like, but is not limited thereto.
Acrylamide can also be used, and specific examples include, but are not limited to, acryloylmorpholine, dimethylacrylamide, dimethylaminopropylacrylamide, isopropylacrylamide, and diethylacrylamide.

  Specific examples of the bifunctional acrylic monomer that can be used as the (meth) acrylate monomer include 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylate, and neopentyl as specific examples of the (meth) acryl monomer. Glycol diacrylate, 1,6-hexane glycol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, propylene glycol diacrylate, tripropylene glycol diacrylate, EO-modified neopentyl glycol diacrylate, propylene oxide side Abbreviated as PO) modified neopentyl glycol diacrylate, bisphenol A diacrylate, EO modified bisphenol A diacrylate, ECH modified bisphenol A diacrylate, EO modified bisphenol S diacrylate, hydroxypivalate ester neopentyl glycol diacrylate, caprolactone modified hydroxypivalate ester neopentyl glycol diacrylate, neopentyl glycol modified trimethylolpropane diacrylate, stearic acid modified pentaerythritol diacrylate , Dicyclopentenyl diacrylate, EO-modified dicyclopentenyl diacrylate, diacryloyl isocyanurate, and the like, but are not limited thereto.

  Specific examples of the trifunctional acrylic monomer that can be used as the (meth) acrylate monomer include trimethylolpropane triacrylate, pentaerythritol triacrylate, EO-modified trimethylolpropane triacrylate, PO-modified trimethylolpropane triacrylate, and ECH-modified triacrylate. Examples include, but are not limited to, methylolpropane triacrylate, ECH-modified glycerol triacrylate, and tris (acryloyloxyethyl) isocyanurate.

  Specific examples of the polyfunctional acrylic monomer that can be used as the (meth) acrylate monomer include ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, alkyl-modified dipentaerythritol pentaacrylate, dipenta Examples thereof include, but are not limited to, erythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, and the like.

Examples of the titanocene photopolymerization initiator used in the present invention include bis (cyclopentadienyl) -bisphenyltitanium and bis (cyclopentadienyl) -bis (2,3,4,5,6- Pentafluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,3,5,6-tetrafluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,4,6-trifluorophenyl) Titanium, bis (cyclopentadienyl) -bis (2,6-difluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,4-difluorophenyl) titanium, bis (methylcyclopentadienyl) -bis (2,3,4,5,6-pentafluorophenyl) titanium, bis (methylcyclopentadienyl) Bis (2,3,5,6-tetrafluorophenyl) titanium, bis (methylcyclopentadienyl) -bis (2,6-difluorophenyl) titanium, bis (cyclopentadienyl) -bis (2,6- Difluoro-3- (pyrrol-1-yl) phenyl) titanium, bis (cyclopentadienyl) -bis (2,4,6-trifluoro-3- (pyrrol-1-yl) phenyl) titanium, bis (cyclo And pentadienyl) -bis (2,4,6-trifluoro-3- (2-5-dimethylpyrrol-1-yl) phenyl) titanium.
These titanocene photopolymerization initiators can be used alone or in combination of two or more.
A preferred titanocene-based compound is bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium.

The blending ratio of the titanocene polymerization initiator (composition name bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) in the present invention is 0.5-2. .5 parts by mass were mixed.
The blending ratio of the titanocene polymerization initiator in the present invention is preferably 0.01 to 10 parts by mass, more preferably, relative to 100 parts by mass of the total amount of the urethane (meth) acrylate oligomer and the (meth) acrylate monomer component. If it is 0.5 to 2.5 parts by mass, if less than 0.5 parts by mass, the photocurability of the composition is lowered and becomes uncured, and the strength may not be sufficiently developed. If it exceeds 5 parts by mass, curing with room light or sunlight proceeds quickly, and it is not suitable for actual work.

Furthermore, the composition of the present invention includes the urethane (meth) acrylate oligomer, (meth) acrylate monomer of the present invention, a radically polymerizable compound of a titanocene polymerization initiator, a pigment, a dye and the like within a range not impairing the characteristics of the present invention. Colorants, inorganic fillers such as calcium carbonate, talc, silica, alumina, aluminum hydroxide, glass, conductive particles such as silver, flame retardants, organic fillers such as acrylic rubber, polyimide resins, polyamide resins, phenoxy resins An appropriate amount of a polymer such as SEBS resin, a thermoplastic elastomer, a plasticizer, an organic solvent, an antioxidant, an antifoaming agent, a silane coupling agent, a leveling agent, or a rheology control agent may be blended.
By these additions, a composition excellent in resin strength, adhesive strength, flame retardancy, workability and the like and a cured product thereof can be obtained.

<Preparation of composition>
Each component was sampled in parts by mass, mixed at room temperature with a planetary mixer for 30 minutes to prepare a photocurable resin composition, and various physical properties were measured as follows. In addition, all the numerical values of detailed adjustment amounts are expressed in parts by mass.

As the photocurable resin composition, various different compositions of the photocurable resins 1 to 9 were prepared for production based on Production Examples 1 to 9.
In addition, each numerical value represents a mass part.

Production Example 1
Urethane (meth) acrylate oligomer (product name: EBECRYL 264, manufactured by Daicel Ornex Co., Ltd., (meth) acrylic monomer containing 15% 1,6-hexanediol diacrylate) 100 parts by mass, titanocene polymerization initiator (composition name bis (cyclopenta Dienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) 1.0 part by mass (product name: IRGACURE 784, manufactured by Ciba Japan KK) in a dark room with a mixer It knead | mixed and the photocurable resin 1 was obtained.
The viscosity was 45,000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 42 ° C., and the elongation at break was 37%.

Production Example 2
Urethane (meth) acrylate oligomer (product name EBECRYL265 manufactured by Daicel Ornex Co., Ltd. (meth) acrylic monomer containing 25% tripropylene glycol diacrylate) 100 parts by mass, titanocene polymerization initiator (composition name bis (cyclopentadienyl) -Bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) 1.0 part by mass (product name: IRGACURE 784 manufactured by Ciba Japan Co., Ltd.) was kneaded with a mixer in a dark room. Thus, a photocurable resin 2 was obtained.
The viscosity was 35,000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 38 ° C., and the elongation at break was 44%.

Production Example 3
Urethane (meth) acrylate oligomer (product name EBECRYL285 manufactured by Daicel Ornex Co., Ltd. (meth) acrylic monomer containing 25% tripropylene glycol diacrylate), titanocene polymerization initiator (composition name bis (cyclopentadienyl) -Bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) 1.0 part by mass (product name: IRGACURE 784 manufactured by Ciba Japan Co., Ltd.) was kneaded with a mixer in a dark room. Thus, a photocurable resin 3 was obtained. The viscosity was 23,000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 42 ° C., and the elongation at break was 56%.

Production Example 4
Urethane (meth) acrylate oligomer (product name EBECRYL1259 manufactured by Daicel Ornex Co., Ltd. (meth) acrylic monomer containing 35% hydroxypropylmethadiacrylate) 100 parts by mass, titanocene polymerization initiator (composition name bis (cyclopentadienyl)- 1.0 part by mass of bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) (product name: IRGACURE 784 manufactured by Ciba Japan Co., Ltd.) was kneaded with a mixer in a dark room. A photocurable resin 4 was obtained.
The viscosity was 12,000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 43 ° C., and the elongation at break was 99%.

Production Example 5
Urethane (meth) acrylate oligomer (product name EBECRYL8411 manufactured by Daicel Ornex Co., Ltd. (Meth) acrylic monomer containing 20% isobornyl acrylate) 100 parts by mass, titanocene polymerization initiator (composition name bis (cyclopentadienyl)- 1.0 part by mass of bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) (product name: IRGACURE 784 manufactured by Ciba Japan Co., Ltd.) was kneaded with a mixer in a dark room. A photocurable resin 5 was obtained.
The viscosity was 150,000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 43 ° C., and the elongation at break was 99%.

Production Example 6
Epoxy (meth) acrylate oligomer (product name EBECRYL600 manufactured by Daicel Ornex Co., Ltd., containing 25% tripropylene glycol diacrylate as a (meth) acrylic monomer), titanocene polymerization initiator (composition name bis (cyclopentadienyl) ) -Bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) 1.0 part by mass (product name: IRGACURE 784 manufactured by Ciba Japan Co., Ltd.) in a dark room with a mixer Thus, a photocurable resin 6 was obtained.
The viscosity was 7,500 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 65 ° C., and the elongation at break was 4%.

Production Example 7
Urethane (meth) acrylate oligomer (product name EBECRYL8800 manufactured by Daicel Ornex Co., Ltd. (meth) acrylic monomer containing 10% ethoxyethoxyethyl acrylate) 100 parts by mass, titanocene polymerization initiator (composition name bis (cyclopentadienyl)- 1.0 part by mass of bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) (product name: IRGACURE 784 manufactured by Ciba Japan Co., Ltd.) was kneaded with a mixer in a dark room. A photocurable resin 7 was obtained.
The viscosity was 250,000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 30 ° C., and the elongation at break was 75%.

Production Example 8
Urethane (meth) acrylate oligomer (product name EBECRYL1259 manufactured by Daicel Ornex Co., Ltd.) containing 92.3 parts by mass of (meth) acrylic monomer (containing 35% of hydroxypropylmethadiacrylate) and 7. (meth) acrylic monomer as hydroxypropylmethadiacrylate 7 parts by mass was added and 1.0 part by mass of titanocene polymerization initiator (composition name bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) ( Ciba Japan Co., Ltd. product name IRGACURE 784) was kneaded with a mixer in a dark room to obtain a photocurable resin 8.
The viscosity was 6000 mPa · s (25 ° C.), the glass transition point of the cured product after complete curing was 50 ° C., and the elongation at break was 80%.

Production Example 9
Urethane (meth) acrylate oligomer (product name EBECRYL264 manufactured by Daicel Ornex Co., Ltd., containing 15% 1,6-hexanediol diacrylate as a (meth) acrylic monomer), titanocene polymerization initiator (composition name bis (cyclo Pentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) 0.4 part by mass (product name: IRGACURE 784 manufactured by Ciba Japan KK) Kneading was performed to obtain a photocurable resin 1.
The viscosity was 45,000 mPa · s (25 ° C.), the glass transition point of the cured product was 42 ° C., and the elongation at break was 37%.

Production Example 10
Urethane (meth) acrylate oligomer (product name: EBECRYL 264, manufactured by Daicel Ornex Co., Ltd., (meth) acrylic monomer containing 15% 1,6-hexanediol diacrylate) 100 parts by mass, titanocene polymerization initiator (composition name bis (cyclopenta Dienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium) 3.0 parts by mass (product name: IRGACURE 784 manufactured by Ciba Japan KK) in a dark room with a mixer It knead | mixed and the photocurable resin 1 was obtained.
The viscosity was 45,000 mPa · s (25 ° C.), the glass transition point of the cured product was 42 ° C., and the elongation at break was 37%.

  Next, the performance tests of Examples 1 to 8 and Comparative Examples 1 to 10 are shown below as shown in FIGS. 2, 3, and 4 using the photocurable resins 1 to 8, respectively. Went to.

[Example 1]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping 10 for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and open the opening 20 (gas opened for experiments). The coating 40 was peeled off with a cutter up to 5 cm in the front and rear, centering on the leakage hole).
About 5 g of the photocurable resin 1 was applied to the opening 20 in a state where no gas was passed.
Then, the photocurable resin 1 was cured by irradiating the photocurable resin 1 with LED light 50 (wavelength 550 nm, intensity 300 lumens) emitting white light for about 3 minutes.
Thereafter, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed by a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, the point where the gas leak was repaired was turned outside, and the bent point (inner radius) R of the assumed flexible pipe 10 was bent at 25 mm around the point where the gas leak was repaired. However, there was no gas leak.

[Example 2]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare a gas flexible pipe 10 (trade name: Soflex caliber 25A) made by Hitachi Metals Co., Ltd., about 1 m, drill a 1 mm hole in the center of the gas pipe with an electric drill, Up to now, the coating 40 was peeled off with a cutter.
About 5 g of the photocurable resin 2 was applied to the opening 20 in a state where no gas was flowing.
Then, the photocurable resin 2 was cured by irradiating the photocurable resin 2 with LED light 50 (wavelength 550 nm, intensity 300 lumens) emitting white light for about 3 minutes.
Thereafter, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed by a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, the point where the gas leak was repaired was turned outside, the bent point (inner radius) of the flexible pipe 10 was bent at 25 mm, centered on the point where the gas leak was repaired, and the gas leak was again detected. Although detected, there was no gas leak.

Example 3
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare a gas flexible pipe 10 (trade name: Soflex caliber 25A) made by Hitachi Metals Co., Ltd., about 1 m, drill a 1 mm hole in the center of the gas pipe with an electric drill, Up to now, the coating 40 was peeled off with a cutter.
About 5 g of the photocurable resin 3 was applied to the opening in a state where no gas was flowing.
Thereafter, the photocurable resin 3 was cured by irradiating the photocurable resin 3 with LED light 50 (wavelength 550 nm, intensity 300 lumens) emitting white light for about 3 minutes.
Thereafter, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed by a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, the point where the gas leak was repaired was turned outside, the bent point (inner radius) of the flexible pipe 10 was bent at 25 mm, centered on the point where the gas leak was repaired, and the gas leak was again detected. Although detected, there was no gas leak.

Example 4
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. A flexible gas pipe 10 (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd. was used.
About 1 m of the flexible pipe 10 for the gas pipe was prepared, a 1 mm hole at the center of the gas pipe was opened with an electric drill, and the coating 40 was peeled off by a cutter up to 5 cm in the front and back, centering on the opening 20.
About 5 g of the photocurable resin 4 was applied to the opening 20 in a state where no gas passed.
Thereafter, the photocurable resin 4 was cured by irradiating the photocurable resin 4 with LED light 50 (wavelength 550 nm, intensity 300 lumens) emitting white light for about 3 minutes.
Thereafter, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed by a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, the point where the gas leakage was repaired was turned outside, and the gas leakage was detected again by bending at the assumed bending radius (inner radius) of the flexible pipe 10 around the point where the gas leakage was repaired. However, there was no gas leak.

Example 5
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare a gas flexible pipe 10 (trade name: Soflex caliber 25A) made by Hitachi Metals Co., Ltd., about 1m, drill a 1mm hole in the center of the gas pipe with an electric drill, and center the opening 20 at the front and back 5cm. Up to this point, the coating 40 was peeled off with a cutter.
City gas was passed at a pressure of 2.5 kPa, and about 5 g of the photocurable resin 1 was applied to the opening 20 in a live tube state.
Then, completely cover with a 14-micron thick transparent uncolored polyethylene film, wrap tightly and press by hand, and then check that no gas leaks through the clear uncolored polyethylene film, This was confirmed with a gas leak detection foam.
Then, the LED light 50 (wavelength 550nm, intensity | strength 300 lumens) which light-emits white light was irradiated to the photocurable resin 1 for about 3 minutes.
Although the transparent uncolored transparent polyethylene film was peeled off, the photocurable resin 1 was cured.
Thereafter, gas leakage was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, the point where the gas leak was repaired was turned outside, the bent point (inner radius) of the flexible pipe 10 was bent at 25 mm, centered on the point where the gas leak was repaired, and the gas leak was again detected. Although detected, there was no gas leak.

Example 6
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of galvanized steel pipe 70 (common name: white gas pipe) made by Hitachi Metals, Ltd. with a diameter of 25A (general threaded joint gas pipe), and make a 1mm hole in the center of the gas pipe to reproduce the gas leak location. About 5 g of the photo-curable resin 1 was applied to the opening with an electric drill opened and with no gas flowing around the opening (Example for preventive maintenance).
Thereafter, the photocurable resin 1 was cured by irradiating the photocurable resin 1 with LED light (wavelength 550 nm, intensity 300 lumens) emitting white light for about 3 minutes.
Thereafter, gas leakage was confirmed with a gas detector (flammable gas detector: XP-702IIZ-B, detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, since it was not possible to bend the pipe, the same bending radius experiment as that of the flexible pipe was not performed.

Example 7
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. A galvanized steel pipe 70 (common name: white gas pipe) manufactured by Hitachi Metals Co., Ltd. is prepared with a diameter of 25 m (general threaded joint gas pipe), and a 1 mm hole in the center of the gas pipe is opened with an electric drill. As a center, city gas was passed at a pressure of 2.5 kPa (live tube state), and about 5 g of the photocurable resin 1 was applied to the opening 20.
Then, after completely covering with a transparent uncolored polyethylene film having a thickness of 14 microns, wrapping firmly and pressing by hand, the gas detector and the gas were inspected that no gas leaked through the transparent uncolored polyethylene film. This was confirmed with the leak detection foam.
Then, the LED light 50 (wavelength 550nm intensity 300 lumens) which emits white light was irradiated to the photocurable resin 1 for about 3 minutes.
Although the transparent uncolored transparent polyethylene film was peeled off, the photocurable resin 1 was cured. After that, gas leakage was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, since it was not possible to bend the pipe, the same bending radius experiment as that of the flexible pipe was not performed.

Example 8
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. An indoor butt joint diameter 25A for gas was used as a mechanical joint manufactured by Hitachi Metals, Ltd. A mechanical joint 60 in which a galvanized steel pipe 70 (common name: white gas pipe) with a diameter of 25A is inserted and tightened by a predetermined method so as to prevent confidentiality from being damaged inside the packing. It was created. With the city gas stopped, about 5 g of the photocurable resin 1 was applied to the mechanical part.
Then, completely cover with a 14-micron thick transparent uncolored polyethylene film, wrap tightly and press by hand, and then check that no gas leaks through the clear uncolored polyethylene film, This was confirmed with a gas leak detection foam.
Then, the LED light 50 (wavelength 550nm intensity 300 lumens) which emits white light was irradiated to the photocurable resin 1 for about 3 minutes.
Although the transparent uncolored transparent polyethylene film was peeled off, the photocurable resin 1 was cured. Thereafter, gas leakage was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
Then, in a state of flowing at 2.5 kPa pressure (live pipe state), both ends of the mechanical joint 60 and the inserted galvanized steel pipe 70 (common name: white gas pipe) are fixed to a tensile tester, and both ends are 3 mm. I pulled. In that state, gas leakage from the mechanical joint 60 was confirmed. Although gas leak was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), it was not detected and there was no gas leak.
That is, gas leakage stopped at the joint of the mechanical piping.

[Comparative Example 1]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and place each 5cm in the front and back, centering on the opening. Until the coating was removed with a cutter.
Two-pack type epoxy resin DEVCON-A (manufactured by ITW Performance Polymers & Fluids Japan Co., Ltd.) was used for the opening without gas flow.
And the gas leak repair work was performed as follows.
About 5 grams of a two-pack type epoxy resin DEVCON-A (ITW Performance Polymers & Fluids Japan Co., Ltd.) main ingredient 9 grams and a curing agent 1 gram were sufficiently applied to the opening.
After leaving for 3 minutes, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm). The leak did not stop.
In other words, gas leakage could not be stopped with the two-component epoxy resin DEVCON-A.

[Comparative Example 2]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and place each 5cm in the front and back, centering on the opening. Until the coating was removed with a cutter.
About 5 g of the photocurable resin 6 was applied to the opening in a state where no gas was flowing.
Then, although the LED light (wavelength 550nm intensity | strength 300 lumens) which light-emits white light was irradiated to the photocurable resin 6 for about 3 minutes, the photocurable resin 6 was hardened.
Thereafter, city gas was passed at a pressure of 2.5 kPa, and a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity: 10 ppm) was confirmed to have a gas leak, but no gas leak was detected.
After that, the point where the gas leak was repaired was turned outside, the bent point (inner radius) of the assumed flexible pipe was bent at 25 mm, and the gas leak was detected again. However, the photocured material was peeled off and gas leakage occurred.

[Comparative Example 3]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible pipe for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and place each around 5cm around the opening. Until the coating was removed with a cutter.
About 5 g of the photocurable resin 7 was applied to the opening in a state where no gas was flowing.
However, it was too viscous and could not be applied, so it did not adhere well.
Thereafter, the LED light (wavelength 550 nm, intensity of 300 lumens) emitting white light was irradiated to the photocurable resin 7 for about 3 minutes, but the photocurable resin 7 was cured.
After that, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but no gas leakage occurred.
After that, the point where the gas leakage was repaired was turned outside, and the gas leakage was detected again by bending at the assumed bending radius (inner radius) of 25 mm of the flexible piping around the point where the gas leakage was repaired. However, a gas leak occurred.
That is, although the photocurable resin 7 had a glass transition point and a breaking elongation within the ranges, the viscosity was too high and the workability was poor and could not be used.

[Comparative Example 4]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. About 1 m of flexible pipe for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd. was prepared, and a 1 mm hole in the center of the gas pipe was drilled with an electric drill. The coating was peeled off with a cutter up to about 5 cm around the opening, and about 5 g of the photocurable resin 8 was applied to the opening in a state where no gas was passed.
However, the viscosity was too low, the fluidity was high, and it could not be applied, so that it did not adhere sufficiently.
Thereafter, the photocurable resin 8 was cured by irradiating the photocurable resin 8 with LED light (wavelength 550 nm, intensity of 300 lumens) emitting white light for about 3 minutes.
After that, city gas was passed at a pressure of 2.5 Kpa and gas leakage was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but no gas leakage occurred.
After that, the point where the gas leak was repaired was turned outside, the bent point (inner radius) of the assumed flexible pipe was bent at 25 mm, and the gas leak was detected again. However, a gas leak occurred.
That is, although the glass transition point and the elongation at break of the photocurable resin 8 were within the ranges, the viscosity was too low to sag and could not close the opening, and the workability was poor.

[Comparative Example 5]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, and open a 1mm hole in the center of the gas pipe with an electric drill. The coating was peeled off with a cutter.
About 5 g of the photocurable resin 1 was applied to the opening in a state where no gas was flowing.
Thereafter, LED light (wavelength 250 nm) emitting white light was irradiated to the photocurable resin 1 for about 3 minutes, but the photocurable resin 1 was poorly cured.
After that, city gas was passed at a pressure of 2.5 Kpa, and a gas detector (combustible gas detector XP-702IIZ-B detection sensitivity 10 ppm) was confirmed to have gas leak, but no gas leak was detected.
In other words, even if the wavelength was too short, the curing reaction could not be carried out, causing a curing failure and causing gas leakage.

[Comparative Example 6]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and place each 5cm in the front and back, centering on the opening. Until the coating was removed with a cutter.
About 5 g of the photocurable resin 1 was applied to the opening in a state where no gas was flowing.
Then, the LED light (wavelength 800nm) which light-emits white light was irradiated to the photocurable resin 1 for about 3 minutes.
However, the photocurable resin 1 was poorly cured.
After that, city gas was passed at a pressure of 2.5 kPa, and gas leakage was confirmed by a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but gas was not detected but leaked.
That is, even if the wavelength was too long, the curing reaction could not be performed, causing a curing failure and causing gas leakage.

[Comparative Example 7]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and place each 5cm in the front and back, centering on the opening. Until the coating was removed with a cutter.
About 5 g of the photocurable resin 9 was applied to the opening in a state where no gas was flowing.
Thereafter, LED light (wavelength 550 nm, intensity of 300 lumens) emitting white light was irradiated to the photocurable resin 9 for about 3 minutes, but the photocurable resin 9 was poorly cured.
After that, city gas was passed at a pressure of 2.5 kPa, and a gas detector (combustible gas detector XP-702IIZ-B detection sensitivity 10 ppm) was confirmed for gas leak, but it was detected and gas leaked.
That is, when the titanocene polymerization catalyst was less than 0.5 parts by mass, it was uncured and gas leakage occurred.

[Comparative Example 8]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. Prepare approximately 1m of flexible piping for gas (trade name: Soflex caliber 25A) manufactured by Hitachi Metals, Ltd., drill a 1mm hole in the center of the gas pipe with an electric drill, and place each 5cm in the front and back, centering on the opening. Until the coating was removed with a cutter.
About 5 g of the photocurable resin 10 was applied to the opening in a state where no gas was flowing.
Curing starts with fluorescent light, working lamps, and minute light from the outside, and before it is applied well to the opening, curing starts and hardens before covering the opening well, covering the opening could not.
After that, city gas was passed at a pressure of 2.5 kPa, and a gas detector (combustible gas detector XP-702IIZ-B detection sensitivity 10 ppm) was confirmed for gas leak, but it was detected and gas leaked.
That is, when the titanocene polymerization catalyst was more than 2.5 parts by mass, the reaction was too early, workability was poor, and gas leakage occurred.

[Comparative Example 9]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. An indoor butt joint diameter 25A for gas was used as a mechanical joint manufactured by Hitachi Metals, Ltd. A mechanical joint that has a gas leak caused by inserting a galvanized steel pipe (common name: white gas pipe) with a caliber of 25A into the inner packing so that it cannot be kept secret. Created. With the city gas stopped, a two-pack type epoxy resin DEVCON-A (ITW Performance Polymers & Fluids Japan Co., Ltd.) was used.
And the gas leak repair work was performed as follows. About 5 grams of a two-pack type epoxy resin DEVCON-A (ITW Performance Polymers & Fluids Japan Co., Ltd.) main component 9 grams and a curing agent 1 gram were sufficiently applied to the mechanical joint.
After leaving for 3 minutes, city gas was passed at a pressure of 2.5 kPa, curing was insufficient, and gas leakage was confirmed, but gas leakage did not stop.
That is, with the two-component epoxy resin DEVCON-A, gas leakage from the mechanical joint could not be stopped.
As a result, the epoxy resin did not stop the gas leakage even at the joint portion of the mechanical piping.

[Comparative Example 10]
Assuming a general work environment, the work was performed in an indoor space with a fluorescent lamp. An indoor butt joint diameter 25A for gas was used as a mechanical joint manufactured by Hitachi Metals, Ltd. A mechanical joint that has a gas leak caused by inserting a galvanized steel pipe (common name: white gas pipe) with a caliber of 25A into the inner packing so that it cannot be kept secret. Created. With the city gas stopped, about 5 g of the photocurable resin 6 was applied to the mechanical part.
Then, completely cover with a 14-micron thick transparent uncolored polyethylene film, wrap tightly and press by hand, and then check that no gas leaks through the clear uncolored polyethylene film, This was confirmed with a gas leak detection foam.
Thereafter, LED light (wavelength 550 nm, intensity 300 lumens) emitting white light was applied to the photocurable resin 6 for about 3 minutes.
Although the transparent uncolored transparent polyethylene film was peeled off, the photocurable resin 1 was cured. Thereafter, gas leakage was confirmed by a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but was not detected and there was no gas leakage.
After that, in a state of flowing at 2.5 kPa (live pipe state), both ends of the galvanized steel pipe (common name: white gas pipe) inserted with the mechanical joint were fixed to a tensile tester, and both ends were pulled 3 mm. . In that state, gas leakage from the mechanical joint was confirmed. Gas leak was confirmed with a gas detector (flammable gas detector XP-702IIZ-B detection sensitivity 10 ppm), but gas leak was detected.
That is, with epoxy (meth) acrylate, the elongation at break was low and did not follow the tensile test, and gas leakage occurred at the joint portion of the mechanical piping.
[Another embodiment]
<1> The inorganic filler may contain calcium carbonate instead of talc, or may contain both talc and calcium carbonate.
<2> The photocurable resin composition may be applied to the entire flexible piping part, and when the gas leaks from the screwed portion, in order to prevent the gas leakage, the surface of the covering part is used. It is good to irradiate the photocurable resin composition with light through the transparent resin film and cure it while covering it with a transparent resin film so that it is airtight and not forming a gas leakage passage. In order to prevent leakage, when the photocurable resin composition is applied to the screw joint portion in advance, the surface of the covering portion may not be covered with a transparent resin film before the photocurable resin composition is cured. .
<3> After applying the photocurable resin composition to the threaded joint part or the mechanical joint part, a method of covering the entire circumference of the covering part with the transparent resin film was adopted. An uncured resin layer adhering portion is formed by applying a photocurable resin composition to the surface of the surface, and the uncured resin layer adhering portion is provided at the outer end of at least the screwed portion of the screw joint portion provided in the gas pipe The protective layer of the joint part can also be formed by adhering to the part to form a cover part, and irradiating the cover part with light through a transparent resin film to cure the photocurable resin composition.
In addition, this method can be used not only for the joint portion but also for closing a portion where a gas leak hole is formed due to corrosion or the like in a conduit main body portion in a general hard gas pipe.
In addition, the present invention is not limited to flexible piping equipment, and can also be used for repair of gas leak locations in pipes of general hard piping facilities and joints thereof, and preventive maintenance of locations where gas leaks may occur. .
That is, it is possible to form a protective layer that is effective for piping equipment that is subjected to vibration or external force.
<4> The present invention can also be used for protecting a joint portion of a steel pipe not coated with a resin other than a joint portion of a coated steel pipe in a gas piping facility.

  In addition, as mentioned above, although the code | symbol was written in order to make contrast with drawing convenient, this invention is not limited to the structure of an accompanying drawing by this entry. In addition, it goes without saying that the present invention can be carried out in various modes without departing from the gist of the present invention.

  The present invention is effective not only for city gas but also for all gases, and is extremely useful as a protection method for gas piping equipment in general.

DESCRIPTION OF SYMBOLS 10 Flexible piping 20 Opening part 30 Covering part 40 Covering 50 LED light 60 Mechanical coupling 90 Transparent resin film R Bending radius

Claims (11)

At least one type of urethane (meth) acrylate oligomer 40 to 90 parts by mass, at least one type of (meth) acrylate monomer 60 to 10 parts by mass, and urethane (meth) acrylate oligomer (meta) ) A coating portion is formed by applying a photocurable resin composition in which 0.5 to 2.5 parts by mass of a titanocene polymerization initiator is mixed with respect to 100 parts by mass of the total amount of acrylate monomer components,
A method for protecting a gas piping facility, wherein the coating portion is irradiated with light to cause the photocurable resin composition to undergo a curing reaction to form a protective layer on an outer peripheral portion of the gas piping facility.   The method for protecting a gas piping facility according to claim 1, wherein the titanocene polymerization initiator is bis (cyclopentadienyl) -bis (2,6-difluoro-3- (pyrrol-1-yl) phenyl) titanium. .   The protection method of the gas piping equipment of Claim 1 or 2 in which the said photocurable resin composition hardened | cured material has a glass transition point of -30 degreeC-50 degreeC.   The method for protecting a gas piping facility according to any one of claims 1 to 3, wherein the cured product of the photocurable resin composition has a breaking elongation of 30% to 300%.   The viscosity of the said photocurable resin composition is the range of 10,000-60,000 mPa * s at 25 degreeC, The protection method of the gas piping installation of any one of Claims 1-4.   The method for protecting gas piping equipment according to any one of claims 1 to 5, wherein the wavelength of light to be cured by the photocurable resin composition is 400 to 700 nm.   The gas piping facility is a flexible piping facility for gas, and after the curing reaction of the photocurable resin composition, the flexible piping is bent at a predetermined bending radius to check for gas leakage. The method for protecting a gas piping facility according to any one of the above.   The said gas piping installation is a mechanical coupling for gas piping, The protection method of the gas piping installation of any one of Claims 1-6. The covering portion covers a gas leaking part of the gas piping facility,
Maintaining the airtightness of the covering portion by tightly winding the transparent resin film while pulling the transparent resin film on the surface of the covering portion,
With the gas leak detection means confirming that gas has not leaked through the transparent resin film, the photocurable resin composition is cured and reacted by irradiating light from the outside of the transparent resin film. The method for protecting a gas piping facility according to any one of claims 1 to 8, wherein a protective layer is formed.   The gas piping equipment according to claim 9, wherein the transparent resin film is any one of the transparent uncolored polyethylene film, the transparent PVC film, or the transparent PVC tape, and peels after the photocurable resin composition is cured. Protection method.   The method for protecting a gas piping facility according to any one of claims 1 to 10, wherein the covering portion covers a gas leakable portion of the gas piping facility.

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