JP2007205155A - Curable resin composition for pre-grout steel member, and prestressed concrete tendon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable resin composition for a pre-grout steel member, and a prestressed concrete tension member using the resin composition for the pre-grout steel member attaining easy tensioning work with excellent application property to a steel member, having excellent rust-proof/corrosion-proof effect and fixing effect and satisfying hardness exhibiting speed after tensioned regarding a resin composition applied to the surface of the prestressed concrete tensioning steel member. <P>SOLUTION: The curable resin composition for the pre-grout steel member contains oxygen curable resin A and solid resin B whose softening point exceeds 40°C, wherein the content of the solid resin B is 5 pts.wt. or more and 60 pts.wt. or less to the total 100 pts.wt. of the oxygen curable resin A and solid resin B. The prestressed concrete tendon uses the resin composition for the pre-grout steel member. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a curable resin composition for a pre-grout steel material, and a prestressed concrete tension material using the resin composition. More specifically, in order to prevent corrosion and rust of the PC tension steel used in the post-tension method of prestressed concrete (hereinafter also referred to as “PC”), and to integrate the PC tension steel and concrete, The present invention relates to a curable resin composition for pre-grout steel applied to the surface of a steel for PC tension. Further, the present invention relates to a PC tension member obtained by coating a steel material coated with this curable resin composition on its surface with a sheath.

  The PC post-tension method is a method in which steel for tension is inserted into a sheath embedded in concrete, the steel for tension is tensioned after the concrete is hardened, tension is applied, and compressive stress is applied to the concrete in advance by the reaction force. It compensates for the shortcomings of concrete with low tensile strength.

  The tension steel used here is covered with a grout material such as cement milk or a resin composition in order to prevent rust and corrosion and to integrate the steel and concrete. In particular, if a PC tension member in which a tension steel material coated with a resin composition (a curable resin composition for a pre-grouting steel material) with an adjusted curing time is used in a sheath is used, an insertion operation of the tension steel material or a grout material is performed. This is preferable because the complexity of the injection work can be solved.

As this curable resin composition for pre-grout steel materials, for example, epoxy-ketimine resin compositions have been proposed (Japanese Patent Laid-Open Nos. 2000-281967 and 2002-60465). On the other hand, JP-A-2004-99834, JP-A-2004-76358, JP-A-2004-76359, etc. point out that an epoxy-ketimine resin composition may cause skin irritation. Instead, a curable resin composition for a pre-grout steel material using an oxygen curable resin has been proposed.
JP 2000-281967 A Japanese Patent Laid-Open No. 2002-60465 JP 2004-99834 A JP 2004-76358 A JP 2004-76359 A

  However, the conventional oxygen curable resin has a problem that its curing rate is slow and it takes time to develop hardness, and its practicality is low as an application as a grout material. Therefore, a curable resin composition (grouting material) for a pre-grout steel material that has a faster curing speed while using an oxygen curable resin has been desired.

  The present invention has been made in view of the above problems, and is a curable resin composition for a pre-grout steel material that is applied to the surface of a steel material for PC tension. A curable resin composition for pre-grout steel that is capable of excellent anti-corrosion / corrosion-prevention and has excellent fixing effect for integrating concrete and steel for tension, and also satisfies the expression rate of hardness after tension. The purpose is to provide. The present invention further provides a PC tendon using this curable resin composition for a pre-grout steel material, in which the steel material is completely anticorrosive, has an excellent fixing effect, and is excellent in the expression of hardness after tension.

  As a result of intensive studies to achieve the above object, the present inventor has a resin composition containing a predetermined amount of a solid resin that is solid at room temperature and compatible with the oxygen curable resin, together with the oxygen curable resin. It has been found that the object achieves the above-mentioned problems, and the present invention has been completed.

  That is, the present invention contains, in claim 1, the oxygen curable resin (A) and the solid resin (B) that is compatible with the oxygen curable resin (A) to form a uniform liquid mixture. A curable resin composition for a pre-grout steel material characterized in that the softening point of the solid resin (B) exceeds 40 ° C., and the content of the solid resin (B) is solid with that of the oxygen curable resin (A). The present invention provides a curable resin composition for a pre-grout steel material, which is 5 parts by weight or more and 60 parts by weight or less with respect to 100 parts by weight in total with the resin (B).

  The present inventor has also found that the speed of development of hardness can be further improved by adding a crosslinking agent (C) to the curable resin composition for pre-grout steel. The invention according to claim 2 has been completed based on this finding, and is the curable resin composition for pregrout steel material according to claim 1, further comprising an oxygen curable resin (A) and a solid resin (B ) In addition to a cross-linking agent (C), the molar equivalent of the cross-linking agent (C) is 0.03 or more with respect to a total of 1 molar equivalent of the carboxyl group and hydroxyl group of the oxygen curable resin (A). The present invention provides a curable resin composition for pre-grout steel, which is 50 or less.

  The inventor further contains a crosslinking agent (C), increases the functional groups in the oxygen curable resin (A) constituting the curable resin composition for pregrout steel materials, and describes the concentration of the functional groups below. It was found that the hardness development rate can be further improved by setting the range. The invention according to claim 3 has been completed based on this finding, and the curable resin composition for pregrout steel according to claim 2, that is, curing for pregrout steel containing the crosslinking agent (C). A curable resin composition for a pre-grout steel material, wherein the sum of the acid value and the hydroxyl value of the oxygen curable resin (A) is 10 or more and 50 or less. is there.

  The oxygen curable resin (A) may be any one having at least one fatty acid that can be oxidatively polymerized in one molecule, and alkyd resin, urethanized oil (oil-modified urethane resin), and fatty acid-modified epoxy ester are oxygenated resins. Examples are curable resins. These are known resins, and the drying oils, polyhydric alcohols, polybasic acids, and isocyanates used in the production thereof are not particularly limited, and the same materials as those for known resins are used. can do.

  As the alkyd resin, an oil-modified alkyd resin obtained by polycondensation of a polyhydric alcohol and a polyvalent carboxylic acid having two or more carboxyl groups, which is modified with (semi) dry oil or (semi) dry oil fatty acid. In addition, fatty acid-modified alkyd resins can be used.

  Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, polypropylene glycol, neoventyl glycol, 1,3-butanediol, 1,6-hexanediol, and triglyceride. Examples include methylene glycol, tetramethylene glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and dipentaerythritol.

  Examples of the polyvalent carboxylic acid include saturated polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic acid, maleic anhydride And unsaturated polybasic acids such as fumaric acid, itaconic acid and citraconic anhydride.

  As the (semi) drying oil or (semi) drying oil fatty acid, those having an iodine value of 100 or more are preferable. Thereby, a high crosslinking density is obtained. Examples of (semi) drying oils used for synthesizing alkyd resins include asami oil, linseed oil, safflower oil, soybean oil, bran oil, cottonseed oil, rice oil, rapeseed oil, tung oil, tall oil and the like.

  (Semi) drying oil fatty acids include ramie oil fatty acid, linseed oil fatty acid, safflower oil fatty acid, soybean oil fatty acid, bran oil fatty acid, cottonseed oil fatty acid, rapeseed oil fatty acid, rapeseed oil fatty acid, tung oil fatty acid, tall oil fatty acid Examples include oil fatty acids, castor oil fatty acids, dehydrated castor oil fatty acids, and coconut oil fatty acids. Further, those modified with a phenol resin, an epoxy resin, isocyanate, or the like can be used.

  Urethane oil is obtained by modifying (semi) drying oil with isocyanate. Here, as the (semi) drying oil, an iodine value of 100 or more is preferable as in the case of the alkyd resin. Examples of isocyanates include tolylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, tetrahydronaphthalene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, Examples thereof include tetramethylxylylene diisocyanate and dimethyldicyclohexylmethane diisocyanate.

  The fatty acid-modified epoxy ester is obtained by modifying a resin having an epoxy group with (semi) dry oil or (semi) dry oil fatty acid. As the (semi) drying oil or the (semi) drying oil fatty acid, those having an iodine value of 100 or more are preferable as in the case of the alkyd resin.

  Examples of the resin having an epoxy group include bisphenol A type epoxy resin, bisphenol F type epoxy resin, condensate of polyhydric alcohol and epichlorohydrin, condensate of polycarboxylic acid and epichlorohydrin, phenol novolac type epoxy resin, ortho Examples thereof include cresol novolac type epoxy resins and brominated products thereof. About the above illustration, one type in illustration can also be used independently or can also use 2 or more types together.

  The curable resin composition for a pre-grout steel material of the present invention is blended with this oxygen curable resin (A) and a solid resin (B) having a softening point exceeding 40 ° C. and having good compatibility with the oxygen curable resin (A). It is characterized by doing. By blending the solid resin (B) with the oxygen curable resin (A), it is possible to increase the rate of development of hardness that was insufficient with the oxygen curable resin (A) alone, and it is suitable as a grout material. A curing rate can be developed.

  The solid resin (B) is a solid resin at room temperature having a softening point of 40 ° C. or higher. With a resin having a softening point of less than 40 ° C., the hardness of the resin at room temperature is insufficient, and the effect of accelerating the hardness development time of the curable resin composition is insufficient. Problems are likely to occur. More preferably, the resin has a softening point of 60 ° C. or higher.

  The solid resin (B) has excellent compatibility with the oxygen curable resin (A) and is mixed with the oxygen curable resin (A) at room temperature to form a uniform liquid mixture (solution). Must be a thing.

  The blending amount of the oxygen curable resin (A) and the solid resin (B) is 5 parts by weight of the solid resin (B) with respect to a total of 100 parts by weight of the oxygen curable resin (A) and the solid resin (B). It is the range above and below 60 weight part.

  When content of solid resin (B) is less than 5 weight part, the expression rate of the hardness of a resin composition falls and the utility as a grout material becomes low. On the other hand, when the amount exceeds 60 parts by weight, there may be a problem in handling such that the viscosity of the resin composition becomes too high and the coating property is lowered. A more preferable range of the content of the solid resin (B) is 10 parts by weight or more and 40 parts by weight or less.

  Resins that can be used as such a solid resin (B) include petroleum resins, xylene resins, styrene resins, resol type phenol resins, novolac type phenol resins, rosin esters, rosin phenols, polyamide resins, polyester resins, urethane resins, and ketones. Examples thereof include resins. One type of resin selected from these resins may be used alone, or two or more types may be used in combination.

  Among them, a resol type phenol resin (resole resin) is preferably exemplified. Claim 4 corresponds to this preferred embodiment. As described above, the curing rate of the resin composition can be improved by blending the solid resin (B). However, when a resole resin is used, it is further improved by utilizing self-polymerization of resole. It is considered that an effect of improving the curing rate can be obtained.

  Here, the resol resin is a product obtained by introducing a methylol group into phenols by heating and condensing phenols and formaldehydes in the presence of a reaction catalyst under the condition that the formaldehydes are excessive. The introduced methylol group may be alkyl etherified.

  Examples of the phenol component constituting the phenol resin include o-cresol, p-cresol, p-tert-butylphenol, p-ethylphenol, p-phenylphenol, 2,3-xylenol, 2,5-xylenol, p- tert-aminophenol, p-nonylphenol, p-cyclohexylphenol, coal acid, m-cresol, m-ethylphenol, 3,5-xylenol, m-methoxyphenol, 2,4-xylenol, 2,6-xylenol, bisphenol A Bisphenol F, and those modified with xylene resin can also be used. These can be used individually by 1 type or in combination of 2 or more types.

  Also, when a petroleum resin is used as the solid resin (B), an excellent effect of improving the curing rate is obtained, which is preferable. Claim 5 corresponds to this preferable mode.

  The petroleum resin is obtained by polymerizing an unsaturated compound obtained when naphtha is decomposed, and includes an aliphatic system using a C5 fraction as a raw material and an aromatic system using a C9 fraction as a raw material. Examples of the C5 system include a cyclopentadiene system, a dicyclopentadiene system, a pentene system, a pentadiene system, an isoprene system, a piperylene system, and a methylbutene system. Examples of the C9 system include a vinyl toluene system and an α-methylstyrene system. , Styrene, indene, and coumarone. These hydrogenated products can also be used. Furthermore, in the petroleum resin, in addition to hydrocarbon bonds, functional groups such as ester bonds, hydroxyl groups, carboxyl groups, and oxidative polymerizable groups can be included in the molecule.

  A crosslinking agent (C) raise | generates a crosslinking reaction with the hydroxyl group and carboxyl group which are contained in oxygen curable resin (A). Since the polyfunctional crosslinking agent (C) having a functional group such as an amino group, an isocyanate group, an acrylic group, or an epoxy group can be added to the oxygen curable resin (A), curing from the inside of the resin composition can be promoted. Further, it is possible to improve the curing rate, which is insufficient with conventional oxygen curing from the surface. Even in the case of thick film coating, uniform curing from the inside can be realized, and an appropriate curing rate can be exhibited as a grout material.

  Examples of the crosslinking agent (C) that can be used include epoxy resins, glycidyl group-containing organosilanes, isocyanates, melamine resins, oxazoline compounds, carbodiimide compounds, and aluminum chelate compounds. One of the above examples can be used alone, or two or more can be used in combination. Furthermore, you may use in combination with thermosetting resins, such as a resole resin and a benzoxazine.

  Examples of the epoxy resin used as the crosslinking agent (C) include bisphenol A type epoxy resin (condensate of bisphenol A and epichlorohydrin), bisphenol F type epoxy resin (condensate of bisphenol F and epichlorohydrin), phenol novolak and epichlorohydrin. A condensate, a condensate of a dihydric alcohol and epichlorohydrin, a condensate of a divalent carboxylic acid and epichlorohydrin, and the like can be used, and these can be used alone or in combination of two or more.

  Specific examples of the epoxy resin include trade names: Epicoat 828, 834, 1001, 871 (manufactured by Japan Epoxy Resin Co., Ltd.), trade names: Epolite 400E, 400P (manufactured by Kyoeisha Yushi Chemical Co., Ltd.), trade names : SR-16H, SR-4GL (manufactured by Sakamoto Pharmaceutical Co., Ltd.).

  Examples of the glycidyl group-containing organosilane used as the crosslinking agent (C) include glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, β-glycidoxyethyltriethoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyl (methyl) dimethoxysilane, γ-glycidoxypropyl (dimethyl) methoxysilane, γ-glycidoxypropyl (ethyl) dimethoxysilane Can be mentioned. Moreover, the oligomer using these can also be used. These glycidyl group-containing organosilanes can be used alone or in combination of two or more. Among these, γ-glycidoxypropyltrimethoxysilane is preferable from the viewpoint of cost and reactivity.

  Examples of the isocyanate compound used as the crosslinking agent (C) include isocyanate monomers such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylene diisocyanate, and adduct modifications thereof. And polyisocyanates such as modified products and isocyanurate-modified products. These can be used alone or in combination of two or more.

  When an isocyanate group-containing resin is used as the crosslinking agent (C), the isocyanate group-containing resin in which the isocyanate group in the isocyanate group-containing resin is blocked with phenol, xylenol, alcohol, ε-caprolactam, MEK oxime, acetylacetone, or the like. It is preferable to use (block type isocyanate group-containing resin).

  As an example of the melamine resin used as the crosslinking agent (C), trade names: Cymel 300, 303, 325 (manufactured by Cytec Co., Ltd.) can be given. Melamine resins can be used alone or in combination of two or more, but it is desirable to use a solvent-free type in view of the physical properties of the cured product.

  Examples of the oxazoline-based compound used as the crosslinking agent (C) include oxazoline group-containing polymers. Specifically, trade names: Epocross RPS-1005, WS-500, WS-700, K-2020E (Co., Ltd.) Nippon Shokubai Co., Ltd.) can be exemplified.

  As the carbodiimide compound used as the crosslinking agent (C), those having at least two carbodiimide groups can be used. Specific examples include trade name: Carbodilite (manufactured by Nisshinbo Industries, Inc.).

  Examples of the aluminum chelate compound used as the crosslinking agent (C) include aluminum ethyl acetoacetate diisopropylate, aluminum tris (ethyl acetoacetate), aluminum tris (acetylacetoacetate), and aluminum bisethylacetoacetate monoacetylacetoacetate. These may be used alone or in combination of two or more. At this time, in order to improve the storage stability, it is desirable to add acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate or the like.

The content of the crosslinking agent (C) is preferably in the range where the molar equivalent is 0.03 or more and 2.50 or less with respect to the total 1 molar equivalent of the carboxyl group and hydroxyl group of the oxygen curable resin (A). When this molar equivalent exceeds 2.50, there is a problem in that the curing rate becomes too fast and a sufficient period for tensioning the steel material cannot be obtained, and the steel is cured before tension. If it is less than 0.03, the effect of improving the curing rate cannot be sufficiently obtained. More preferably, it is 0.1 or more and 2.0 or less. In addition, the molar equivalent of the carboxyl group and the hydroxyl group per 1 g of the weight of the oxygen curable resin (A) has the following relationship with the acid value and the hydroxyl value.
Carboxyl group molar equivalent = acid value / 56110
Molar equivalent of hydroxyl group = hydroxyl value / 56110

  As described above, when the crosslinking agent (C) is added and the concentration of the functional group, particularly the carboxyl group, contained in the oxygen curable resin (A) is increased, the curing rate of the curable resin composition for pregrout steel is increased. Since it can improve more, it is preferable. It is considered that by increasing the functional group concentration in the oxygen curable resin (A), the number of crosslinking points in the oxygen curable resin (A) can be increased, so that the curing rate can be improved.

  Specific means for increasing the functional group (carboxyl group) concentration in the oxygen curable resin (A) include a method of increasing the amount of acid in the synthesis of the oxygen curable resin (A), an oxygen curable resin ( Examples thereof include a method of adding an acid (trimellitic anhydride) to the hydroxyl group of A).

  As an index specifically indicating the functional group concentration, an acid value and a hydroxyl value can be used, and the sum of the acid value and the hydroxyl value is preferably in the range of 10 or more and 50 or less. If it is less than 10, there is a problem that the curing rate is not sufficiently improved. More preferably, it is 15 or more and 40 or less.

  In the curable resin composition for a pre-grout steel material of the present invention, the curing rate can be adjusted by further blending a metal catalyst at an appropriate ratio. Claim 6 corresponds to an embodiment in which this metal catalyst is blended. Metal catalysts include cobalt naphthenate, calcium naphthenate, lithium naphthenate, manganese naphthenate, lead naphthenate, zinc naphthenate, copper naphthenate, zirconium naphthenate, cobalt octylate and calcium octylate. , Octylates such as manganese octylate, copper octylate, lead octylate, zinc octylate, zirconium octylate, aluminum octylate, stannous octylate, and the like, and one or more of these are used. be able to.

  It is preferable that a metal catalyst is 0.05-1 weight part in conversion of a metal part with respect to 100 weight part in total of oxygen curable resin (A) and solid resin (B). That is, when the content of the metal catalyst is less than 0.05 parts by weight, curing by oxidation is delayed. In addition, when the amount of the metal catalyst is increased, the amount of the solvent used for diluting the metal catalyst increases, and voids may be generated when a sheath often formed from polyethylene or the like is extrusion coated. Therefore, it is not preferable. More preferably, it is the range of 0.1-0.8 weight part in conversion of a metal part.

  Moreover, various fillers can be mix | blended with the curable resin composition for pregrout steel materials of this invention for hardness development, a viscosity adjustment, and thixotropy adjustment. Claim 7 corresponds to this aspect. Examples of the filler include talc, calcium carbonate, calcium oxide, precipitated barium sulfate, silica, Aerosil (ultrafine anhydrous silicon dioxide, trade name of Nippon Aerosil Co., Ltd.), zeolite, and the like. The range of the blending amount of the filler is not particularly limited, and is appropriately determined in consideration of the relationship between the viscosity and the hardness.

  Furthermore, a small amount of an organic solvent or the like can be blended with the curable resin composition for a pre-grout steel material of the present invention for viscosity adjustment or the like. However, if an organic solvent is included, there is a possibility of causing environmental or operational problems, and the amount of solvent may be reduced because the active ingredient may decrease due to the evaporation of the solvent. A smaller amount is preferable, and use without a solvent is more preferable.

  The resin composition for a pre-grout steel material of the present invention preferably has a viscosity at 25 ° C. of 10 to 250 Pa · s, more preferably 15 to 150 Pa · s, from the viewpoint of coating operation and storage stability. Furthermore, log [η5] / log [η40] is 3 when the viscosity at 40 ° C. is 5 Pa · s or more, the viscosity at 5 ° C. is [η5], and the viscosity at 40 ° C. is [η40]. It is preferably less than 0. Claim 8 corresponds to this preferable mode.

  When the viscosity at 40 ° C. is less than 5 Pa · s, the fluidity of the resin composition becomes too large in summer and the application work becomes difficult. In addition, when log [η5] / log [η40] is 3.0 or more, the fluctuation range of the condition at the time of application becomes large, and the number of days that can be tensioned varies depending on the season. log [η5] / log [η40] is more preferably less than 2.7.

  The PC tension material using the steel material for PC tension coated with the resin composition is embedded in the concrete before hardening by the post-tension method, and when the concrete is hardened to some extent, the steel material for PC tension is tensioned to the concrete. Apply compressive stress. Therefore, until the concrete has hardened to some extent, it is necessary that it does not harden (even if the heat generated by the concrete is large). On the other hand, after the tension, it is preferable to harden in as short a time as possible.

  In the single use of the oxygen curable resin, it is difficult to achieve curing in a short time after tension, but in the resin composition of the present invention, since a solid resin is added, the curing rate is improved, It is possible to adjust the curing rate so as to satisfy the above conditions. The curing rate can be adjusted by adjusting the content of the metal catalyst relative to the oxygen curable resin, or by changing the type of fatty acid (iodine value) used for modification. Moreover, it becomes possible to improve a cure rate more by adding a crosslinking agent as mentioned above, or increasing the functional group in oxygen curable resin.

  Although it does not specifically limit about the method of manufacturing the curable resin composition for pregrout steel materials of this invention, For example, the following methods are mentioned. First, the solid resin (B) is dissolved or dispersed in the oxygen curable resin (A), then a filler is added if necessary, and a predetermined amount of a crosslinking agent (C) or a metal catalyst is added if necessary. Blend and mix with a mixer. After completion of mixing, defoaming is performed under vacuum to obtain a target curable resin composition for pre-grout steel.

  The curable resin composition for pregrout steel materials of the present invention is applied to the surface of a steel material for PC tension. In order to facilitate this coating operation, as described above, it is desirable that the resin composition has a viscosity range having an appropriate fluidity at the coating temperature. The application temperature is preferably around 0 to 40 ° C., but may be applied while heating the resin composition as necessary.

  As the steel material for PC tension, the same as the pre-grout steel material used conventionally is used. Specifically, it is a steel wire, a steel rod, etc., and in particular, a product obtained by twisting a plurality of steel wires.

  The present invention further provides a PC tendon using the curable resin composition for pregrout steel. That is, a steel material for PC tension, a coating layer that covers the surface of the steel material for PC tension, including a grout material layer made of the curable resin composition for pregrout steel material of the present invention, and a sheath that covers the outer periphery of the coating layer It is a PC tendon material characterized by having (Claim 9).

  In order to effectively exhibit the effect of the curable resin composition for a pre-grout steel material of the present invention, the thickness of the curable resin composition for a pre-grout steel material, that is, the thickness of the grout material layer is preferably 20 μm or more. If this thickness is less than 20 μm, the edge cutting between the steel material for PC tension and the sheath is not sufficient at the time of tension, and the friction coefficient becomes large and sufficient tension cannot be performed.

  The grout material layer is a layer made of the curable resin composition for pregrout steel material of the present invention, and the surface of the steel for PC tension is covered with a coating layer containing this grout material layer, and this coating layer will be described in detail later. Covered by the sheath described. Although this coating layer may consist only of a grout material layer, it may contain other layers. For example, the surface of the PC tension steel may be coated with a grout material layer, and another layer may be formed on the outside thereof, or another layer may be formed on the surface of the PC tension steel, and the grout material on the outside thereof. A layer may be formed.

  The grout material layer may be formed, for example, by applying the curable resin composition for pregrout steel material of the present invention to the surface of the steel material for PC tension or the surface of another layer formed on the steel material for PC tension. it can. The application method is not particularly limited. For example, a steel box for PC tension (including those in which other layers are formed) is passed through a resin box filled with the resin composition, and is provided at the outlet of the resin box so that a desired coating thickness is achieved. And a method of uniformly applying a predetermined amount of resin by removing excess resin with a hole having a diameter designed in (1). Another layer may be formed on the surface of the grout material layer thus formed.

  The outer periphery of the coating layer comprising the grout material layer and optionally one or more other layers is covered with a sheath. As the sheath, the same sheath as that used in conventional PC tendons can be used. For example, a sheath or a metal sheath formed from a thermoplastic resin such as polyethylene is used. The sheath surface is preferably provided with irregularities in order to ensure its fixation with concrete.

  The PC tension material of the present invention can be manufactured by inserting a steel material for PC tension having a coating layer including a grout material layer on the surface thereof into the sheath as described above. The PC tendon of the present invention thus obtained has a steel material (usually a twist of a plurality of steel wires) in the center in a cross section perpendicular to the length direction, and the periphery of the PC tendon is of the present invention. It is covered with a covering layer including a grout material layer made of a resin composition, and the periphery thereof is covered with a sheath. As a result of the steel for PC tension being further covered by the sheath, its corrosion protection is more complete.

  The PC tendon of the present invention thus obtained can be used in a post tension method. That is, this PC tension material is embedded in the concrete before hardening, and when the concrete is hardened to some extent, the PC tension steel material is tensioned to give compressive stress to the concrete. The resin composition of the present invention has a curing rate adjusted so that the concrete is not cured until it is cured to some extent so that the tension is smoothly performed, while it is cured in a short time at room temperature after the tension. Therefore, the fixing effect between the PC tendon of the present invention and the concrete is also excellent.

  The post-tension method includes a steel material for PC tension, a grout material layer made of the curable resin composition for pre-grouting steel material of the present invention, and a coating layer that covers the surface of the steel material for PC tension, and covers the outer periphery of the coating layer In the case of using a PC tendon having a sheath to be used, an operation of inserting a tension steel material and an operation of injecting a grout material are unnecessary, and the troublesomeness associated with these operations can be solved. Moreover, the curable resin composition for pre-grout steel material of the present invention has an excellent fixing effect, is excellent in integration with concrete after tension of the steel material, and is also excellent in rust prevention and anticorrosion effects on the tension steel material. Is.

  Furthermore, even when this resin composition is exposed to high temperatures due to heat generated during the curing of the concrete, the resin does not harden before the concrete is cured and does not make the tension work difficult. Moreover, the expression rate of the hardness after steel material tension is also satisfied. In particular, when a cross-linking agent is added or the functional group in the oxygen curable resin is increased, the curing rate can be further increased, and the expression rate of the hardness after the steel material tension is more satisfied.

  Next, the best mode for carrying out the present invention will be described below with reference to examples, but the present invention is not limited to these examples.

(Adjustment Example 1) (Adjustment of alkyd resin A)
A flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a reflux condenser was charged with 721 parts by weight of linseed oil (iodine number: 187), 99 parts by weight of pentaerythritol, and 0.8 parts by weight of lithium naphthenate while stirring. The temperature was raised to 250 ° C. After maintaining at 250 ° C. for 1 hour, the temperature was lowered to 180 ° C., 180 parts by weight of phthalic anhydride and 20 parts by weight of xylene were further charged, and the temperature was raised to 250 ° C. again. The mixture was stirred at 250 ° C. for 5 hours while dehydrating under reflux of xylene, and then the flow rate of nitrogen gas was increased and stirring was further performed for 1 hour at 250 ° C. to collect xylene and obtain an alkyd resin. The resin had an oil length of 74%, a viscosity at 25 ° C. of 2.9 Pa · s, an acid value of 4.5, and a hydroxyl value of 28.

(Adjustment Example 2) (Adjustment of alkyd resin C)
A flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a reflux condenser was charged with 703 parts by weight of linseed oil (iodine number: 187), 97 parts by weight of pentaerythritol, and 0.8 parts by weight of lithium naphthenate while stirring. The temperature was raised to 250 ° C. After maintaining at 250 ° C. for 1 hour, the temperature was lowered to 180 ° C., 176 parts by weight of phthalic anhydride and 20 parts by weight of xylene were further charged, and the temperature was raised to 250 ° C. again. While stirring at 250 ° C. for 5 hours while dehydrating under reflux of xylene, the nitrogen gas flow rate was increased and stirring was continued for an additional hour at 250 ° C. to recover xylene. The temperature was lowered to 160 ° C., 24 parts by weight of trimellitic anhydride was added, and the mixture was stirred at 160 ° C. for 1 hour to obtain an alkyd resin. This resin had an oil length of 73%, a viscosity at 25 ° C. of 9.8 Pa · s, an acid value of 19, and a hydroxyl value of 16.

(Adjustment Example 3) (Adjustment of urethanized oil)
A flask equipped with a stirrer, a thermometer, a nitrogen gas inlet tube, and a reflux condenser was charged with 850 parts by weight of linseed oil (iodine number: 187), 50 parts by weight of pentaerythritol, and 0.1 parts by weight of sodium hydroxide while stirring. The temperature was raised to 250 ° C. After maintaining at 250 ° C. for 1 hour, the temperature was lowered to 50 ° C., 100 parts by weight of tolylene diisocyanate was further added, stirred for 2 hours, and further stirred at 120 ° C. for 2 hours to obtain a urethanized oil. The resin had an oil length of 85%, a viscosity at 25 ° C. of 1.5 Pa · s, an acid value of 0.1, and a hydroxyl value of 25.

  80 parts by weight of alkyd resin A (oxygen curable resin (A)) obtained in Preparation Example 1, butylphenol resole resin (solid resin (B), trade name: Resitop PS-2607, Gunei Chemical Industry Co., Ltd.) Manufactured, softening point: 65 to 80 ° C.) mixed with 80 parts by weight at 80 ° C. for 1 hour, a filler consisting of 2.5 parts by weight of Aerosil, 80 parts by weight of talc and 40 parts by weight of calcium carbonate, and As a curing catalyst, 9 parts by weight of 4% zirconium naphthenate and 1 part by weight of 6% cobalt naphthenate were mixed to obtain a curable resin composition for pre-grout steel.

  A curable resin composition for pre-grout steel was obtained in the same manner as in Example 1 except that the urethanized oil obtained in Preparation Example 3 was used as the oxygen curable resin (A).

  As solid resin (B), C9 petroleum resin (C9 aromatic hydrocarbon fraction polymer, trade name: Neopolymer 120: manufactured by Nippon Petrochemical Co., Ltd., softening point: 120 ° C.) is used, and oxygen curable resin A curable resin composition for a pre-grout steel was obtained in the same manner as in Example 1 except that the mixing temperature of (A) and the solid resin (B) was changed from 80 ° C to 130 ° C.

  In addition to the same formulation as in Example 1, 1.7 parts by weight of carbodilite V-05 (carbodiimide-based crosslinking agent: manufactured by Nisshinbo Co., Ltd.) as the crosslinking agent (C) (carboxyl group of the oxygen curable resin (A)) And 0.14 molar equivalents with respect to the total of 1 molar equivalent of hydroxyl groups), and the others were the same as in Example 1 to obtain a curable resin composition for a pre-grout steel material.

  As the oxygen curable resin (A), the alkyd resin C obtained in Preparation Example 2 was used, and as the crosslinking agent (C), organosilane S-510 (organosilane-based crosslinking agent: manufactured by Chisso Corporation) 6.4. A curable resin for a pre-grout steel material in the same manner as in Example 4 except for blending parts by weight (0.54 molar equivalents relative to a total of 1 molar equivalent of the carboxyl group and hydroxyl group of the oxygen-curable resin (A)). A composition was obtained.

(Comparative Example 1)
The same procedure as in Example 1 was conducted except that the amount of the alkyd resin (oxygen curable resin (A)) obtained in Preparation Example 1 was 100 parts by weight and the solid resin (B) such as butylphenol resole resin was not mixed. Thus, a curable resin composition for a pre-grout steel material was obtained.

(Comparative Example 2)
The same as Example 2 except that the amount of the urethanized oil (oxygen curable resin (A)) obtained in Preparation Example 3 was 100 parts by weight and the solid resin (B) such as butylphenol resole resin was not mixed. Thus, a curable resin composition for a pre-grout steel material was obtained.

(Comparative Example 3)
Example 1 except that the amount of alkyd resin (oxygen curable resin (A)) obtained in Preparation Example 1 was 98 parts by weight and the amount of butylphenol resole resin (solid resin (B)) was 2 parts by weight. In the same manner as above, a curable resin composition for pre-grout steel was obtained.

  The resin compositions for pregrout steel materials obtained in the above examples and comparative examples were evaluated for the curing rate by the following method, and the viscosity (5 ° C., 25 ° C., 40 ° C.) and nonvolatile content (%) were determined. It measured by the method shown below. The results are shown in Table 1.

[Evaluation of curing speed]
The obtained resin composition for pregrout steel was applied to a polypropylene petri dish at a thickness of 8 mm, and the Shore D hardness after being left at 90 ° C. for 30 days was measured to evaluate the curing rate.

[viscosity]
It measured at 5 degreeC, 25 degreeC, and 40 degreeC using the E-type viscosity meter (Corporation | KK Rheology make, MR-300VII type | mold).

[Measurement method of non-volatile content]
The measurement was performed in accordance with “Nonvolatile content measurement” defined in JIS K 6833 “General test method for adhesive”.

As is clear from the results shown in Table 1, the resin compositions for pre-grout steel materials of Examples 1 to 5 (product of the present invention) exhibited high Shore D hardness when left at 90 ° C. for 30 days, and the post-tension method It is considered that the rate of development of hardness after PC tension is also satisfied when used in the above. On the other hand, it is considered that the compositions of Comparative Examples 1 to 3 do not cure when left at 90 ° C. for 30 days, and the rate of development of hardness after tension is insufficient.

Claims (9)

  A curable resin composition for a pre-grout steel material comprising an oxygen curable resin (A) and a solid resin (B) that is compatible with the oxygen curable resin (A) to form a uniform liquid mixture The softening point of the solid resin (B) exceeds 40 ° C., and the content of the solid resin (B) is 100 parts by weight in total of the oxygen curable resin (A) and the solid resin (B). On the other hand, the curable resin composition for a pre-grout steel material, which is 5 parts by weight or more and 60 parts by weight or less.   Furthermore, it contains a crosslinking agent (C), and the molar equivalent of the crosslinking agent (C) is 0.03 or more and 2.50 or less with respect to the total 1 molar equivalent of the carboxyl group and hydroxyl group of the oxygen curable resin (A). The curable resin composition for a pre-grout steel material according to claim 1, wherein   The sum of the acid value and hydroxyl value of oxygen-curable resin (A) is 10 or more and 50 or less, The curable resin composition for pregrout steel materials of Claim 2 characterized by the above-mentioned.   The curable resin composition for a pre-grout steel material according to any one of claims 1 to 3, wherein the solid resin (B) is a resol resin.   The curable resin composition for a pre-grout steel material according to any one of claims 1 to 3, wherein the solid resin (B) is a petroleum resin.   The metal catalyst for curing the oxygen curable resin (A) is 0.05 to 1 part by weight in terms of metal with respect to a total of 100 parts by weight of the oxygen curable resin (A) and the solid resin (B). The curable resin composition for a pre-grout steel material according to any one of claims 1 to 5, further comprising:   Furthermore, a filler is included, The curable resin composition for pregrout steel materials in any one of Claim 1 thru | or 6 characterized by the above-mentioned.   The log [when the viscosity at 25 ° C. is 10 to 250 Pa · s, the viscosity at 40 ° C. is 5 Pa · s or more, the viscosity at 5 ° C. is [η5], and the viscosity at 40 ° C. is [η40]. The curable resin composition for a pre-grout steel material according to any one of claims 1 to 7, wherein η5] / log [η40] is less than 3.0. Prestressed concrete tension steel,
A coating layer that covers the surface of the steel material for prestressed concrete tension, comprising a grout material layer comprising the curable resin composition for a pregrout steel material according to any one of claims 1 to 8, and
A prestressed concrete tendon having a sheath covering the outer periphery of the covering layer.