JP2002363313A - Prepreg of normal-temperature diffusion cure type, its production method, and fastening execution method for concrete construction utilizing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prepreg improved in moldability in processing and in quality stability, its production method, and a fastening execution method for a concrete construction utilizing the properties of the prepreg. SOLUTION: A fibrous reinforcement is impregnated with a resin composition which diffuses and cures at the normal temperature in the atmospheric air, and thus impregnated reinforcement is left standing at the normal temperature in the air, giving the prepreg of which the surface is cured and the inside is not cured. In the fastening execution method for a concrete construction, the circumference of a concrete construction Q having cracks occurred thereon is fastened with a belt-shaped fastening member which is prepared by impregnating a baggage-hanging belt 1 prepared by sewing a fiber aggregate impregnated with the resin composition in the same way as above and curing the surface of the resultant prepreg.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room temperature diffusion hardening type prepreg, a method for producing the same, and a method for tightening a concrete structure using the same. A prepreg that stabilizes the quality of molded products, its manufacturing method, and its properties to reinforce a revolvable concrete structure and to provide an emergency to protect buildings that have once escaped from an earthquake from collapsing due to aftershocks As a measure, the present invention relates to a method for tightening a concrete structure used for temporarily reinforcing a concrete structure.

[0002]

2. Description of the Related Art A prepreg, which is a molding material obtained by impregnating a fiber reinforcing material with a resin, has a role as an intermediate product, and has a form of a slightly tacky (uncured) wound in a roll. Such a sheet-like material and a rigid plate-like material having no tackiness as seen in a multilayer printed wiring board are known.

[0003] Each of these is formed by impregnating a heat-curable resin into a fiber reinforcing material. In the case of a sheet-like material, it is uncured and rolled with a release paper therebetween. The product is wound into a shape, manufactured, transported, and stored. The formed product is formed into a material for various products, and finally heat-cured to produce a product.

[0004] Originally, prepreg is an intermediate material used for ease of molding and for stabilizing the quality of the molded product. What is common to conventional prepregs is that the matrix resin is initially in an uncured state, By heating after molding, the entire resin is softened or melted, and melts with each other while lowering the viscosity. Then, the resin is integrated with the fiber reinforcing material while being cross-linked by a chemical reaction, and reaches curing.

[0005]

However, when a sheet-like material that has been rolled up in an uncured state is used, there is a problem of disposal of the release paper after use. In addition, the surface of the uncured sheet-like material unnecessarily adheres during the molding process and deteriorates the workability of molding, and dust or the like adheres to the surface of the sheet-like material to reduce the quality of the product. There are problems such as giving a bad influence, and further, uncured resin adheres to the periphery.

SUMMARY OF THE INVENTION An object of the present invention is to provide a prepreg improved in workability and quality stability during molding by maintaining a hardened surface while maintaining an uncured interior, and a method of manufacturing the same. Utilizing the properties of the prepreg obtained in this manner, it is possible to reinforce a revolvable concrete structure and apply a compressive force from the periphery to the concrete structure once cracked or the like, to apply a lateral prestress to the concrete structure. It is an object of the present invention to provide a method for tightening concrete structures using a prepreg for applying stress to adhere and re-aggregate the concrete to protect the collapse of the building from aftershocks.

[0007]

According to the present invention, in order to achieve the above object, a prepreg of the present invention is a molding material obtained by impregnating a fiber reinforcing material with a resin composition which is diffusion-hardened at room temperature in the air. The gist is that the surface of the molding material is in a cured state and the inside is in an uncured state.

Here, as the resin composition which diffuses and cures at room temperature in the air, a composition obtained by blending a latent curing agent with the resin is used. As the latent curing agent to be blended in the composition, it is preferable to use a curing agent containing ketimine as a main component.

[0009] Thereby, at the time of forming the product,
When prepregs can be flexibly deformed or sheared as a molding material, when prepregs are laminated, etc., there is no adhesion of materials and they slide easily with each other. Since the surface of the prepreg itself is not sticky, there is no adhesion of dust and the like, and the stability of quality is guaranteed.

The method for producing a room-temperature diffusion-curable prepreg of the present invention comprises the steps of: (a) immersing a resin composition which is diffusion-cured at room temperature in the air in a fiber reinforcing material to form a molding material; Is to cure the surface by leaving it in the air at room temperature.

The method for producing a room-temperature diffusion-curable prepreg according to the present invention comprises the steps of: (b) impregnating a fiber-reinforced body with a resin composition which is diffusion-cured at room temperature in the atmosphere to form a molding material;
The gist of the present invention is to keep this molding material shielded from the outside air, store it, immediately before using the molding material, release the molding material to the atmosphere, and leave it in air at room temperature to cure the surface. It is.

Further, the method for producing a room-temperature diffusion-curable prepreg according to the present invention comprises: (c) cooling the molding material to freeze the resin composition when storing the molding material while shielding the molding material from the outside air; The gist of the present invention is to defrost the molding material immediately before using the molding material before releasing the molding material to the atmosphere.

Thus, the prepreg adsorbs moisture, oxygen, or humidity in the air at normal temperature from the surface and gradually diffuses the inside to advance the curing of the resin (a network polymer system). A prepreg with a hardened surface and an uncured interior is obtained, which guarantees ease of molding and stability of quality.

In the case where the prepreg is stored for a certain period of time and the start of curing due to the adsorption of moisture or oxygen in the air is delayed in relation to the timing of product processing by the prepreg, the above-mentioned process (b) may be used. When the method is adopted and the start of curing is further delayed, the production method (c) is adopted.

Further, the invention of a method for tightening a concrete structure according to the present invention comprises: (d) sewing a fiber assembly to form a suspended load belt having joint engaging portions at both ends; A band-shaped tension member is formed by impregnating a resin composition that is diffusion-hardened at room temperature in the air, and then the surface is cured by leaving the band-shaped tension member at room temperature in the air,
The gist of the present invention is that the belt-shaped tension member is wound around the concrete structure and both ends of the joint locking portion are tightened by tightening means to be fixed around the concrete structure.

Further, another invention of the method for tightening a concrete structure according to the present invention comprises the steps of: (e) sewing a fiber assembly to form a hanging belt having joint locking portions at both ends; A belt-shaped tension member is formed by impregnating the belt with a resin composition that is diffusion-hardened at room temperature in the air, and thereafter, the belt-shaped tension member is shielded from the outside air and stored. It is opened to the inside, the surface is hardened by leaving it in the air at room temperature, and the band-shaped tension member is wound around the concrete structure, and both ends of the joint locking portion are tightened by tightening means. The gist of the invention is to tighten and fix the periphery of an object with a belt-shaped tensioning member.

Further, when the band-shaped tension member is shielded from the outside air and stored, the resin is frozen by cooling the band-shaped tension member to release the blockage of the band-shaped tension member from the outside air immediately before construction. The gist of the present invention is to thaw the band-shaped tension member beforehand.

Thus, regardless of the difference in the outer peripheral shape of the concrete structure, the band-shaped tightening member can be tightened from the periphery of the concrete structure, and the hardening of the band-shaped tightening member gradually progresses with time. Therefore, a compressive force from around the concrete structure is secured to protect the collapse of the building from aftershocks.

In the case where the belt-shaped tension member is stored for a certain period and the start time of the hardening due to the adsorption of moisture or oxygen in the air is delayed in relation to the tensioning time of the concrete structure, (b) If the tightening method of (c) is adopted and the start time of hardening is further delayed, the tightening method of (c) above is adopted.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

In a typical embodiment of the prepreg of the present invention, a fiber reinforced material is impregnated with a resin which diffuses and hardens at room temperature in the air to form a molding material, and the molding material is allowed to stand at room temperature in the air. It can be manufactured. The molding material obtained in this way has a hardened surface and an unhardened interior.

Here, the uncured state refers to a state of the resin which remains tacky and can be plastically deformed, and includes a state in which a slight curing reaction has progressed and the viscosity and the like have increased.

The form of the fiber reinforcing material to be used is not particularly limited, but fiber bundles, various woven fabrics, non-woven fabrics, and material forms appropriately constituted by using these are widely used. Fiber, aramid fiber,
Polyester fiber, polyamide fiber, etc. are widely used.

The mechanism of curing of a resin which diffuses and cures in the atmosphere is that moisture and oxygen in the atmosphere are adsorbed from the free surface of the resin, and the curing gradually progresses from the surface as the resin diffuses inside. Although it refers to a network polymer system, the present invention also includes a curing mechanism for a paint-type resin in which a solvent volatilizes from the free surface of the resin into the atmosphere and gradually cures toward the inside.

The resin used in the present invention is, for example, a resin material selected from a liquid resin mainly composed of an epoxy resin having a bisphenol A skeleton and an epoxy resin having a bisphenol F skeleton alone or in a mixture at room temperature. A composition containing a latent curing agent having a function of adsorbing moisture and oxygen therein and diffusing it inside is used. In addition, resin
It is also possible to appropriately include a reactive diluent, a filler and the like.

As a latent curing agent that adsorbs moisture from the free surface of the resin and gradually diffuses the moisture into the interior to accelerate the curing of the resin, a curing agent containing ketimine as a main component is effective.

In this case, water molecules adsorbed and diffused from the free surface of the resin react with ketimine to decompose into amines and ketones, which are taken in as part of each and disappear. Then, the amine bonds with the resin and cures by progressing to three-dimensionalization. As described above, the diffusion and infiltration of an externally-derived substance called water molecule triggers the curing, and the curing proceeds gradually from the surface layer to the deep part with a time lag.

As the oxygen-curable resin, for example,
A blend of a thiol group-containing resin and a metal chelate compound is exemplified, and examples of the moisture-curable resin include oxazolidines in addition to ketimines.

The prepreg obtained as described above can be flexibly bent or sheared during molding of a product using the prepreg. Since there is no adhesion of materials, they slide easily with each other, so that molding is easy. Further, since the surface of the prepreg itself is not sticky, there is no adhesion of dust and the like, and the stability of quality is guaranteed.

Also, while being flexible at the time of forming a product, it is hardened toward the inside with the lapse of time by leaving it in the air at room temperature, and the property that the product is completely cured is finally used. As a temporary measure to reinforce a revolvable concrete structure and to protect a building that once escaped from an earthquake from collapsing due to aftershocks, the prepreg according to the present invention is reinforced by tightening the concrete structure from the surroundings. Succeeded in adopting it as the material of the band-shaped tightening member used in the above.

Hereinafter, an embodiment in which a concrete structure is tightened by utilizing the properties of the prepreg obtained by the present invention will be described in detail with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 (a) is a plan view showing one embodiment of a hanging belt made of a fiber assembly constituting a belt-shaped tightening member of the present invention, and FIG. 1 (b) is obtained by impregnating the belt with a resin. FIG. 4 shows a plan view of the formed band-shaped tightening member. FIG. 2 is a perspective view for explaining an embodiment when the tightening work of the present invention is applied to a columnar concrete structure, and FIG. 3 is a cross-sectional view of the columnar concrete structure of FIG. Is shown.

As shown in FIG. 1 (a), a fiber assembly is sewn to form a suspended load belt 1 having eyeglass-shaped joint locking portions 3, 3 'at both ends. The band-shaped tightening member 2 shown in FIG. 1 (b) was formed by impregnating with a resin composition which is to be hardened by diffusion, and then left in the air at room temperature for 24 hours.

The belt-shaped tightening member 2 thus obtained
Are wound around the concrete structure Q where cracks or the like have once formed, as shown in FIG. 2, and as shown in FIGS. 4 (a) and 4 (b), the joint locking portions 3,
3 ', a supporting member 4 projecting in the width direction of the band-shaped tightening member 2,
4 ′ is inserted, and the upper and lower projecting portions of the support members 4, 4 ′ are connected by the tightening means 5.

Examples of the concrete structure Q include not only concrete columns, but also piers, prestressed concrete, concrete piles, and the like. Also, a penetration material such as a steel rod may be combined and wound around a pillar with a wall.

That is, the tightening means 5 includes a support member 4, 4 'having through holes 4a at both ends, and a bolt, nut or the like which is inserted through the through holes 4a provided in the support members 4, 4' and connected. At the time of construction, a tension is applied to the belt-shaped tightening member 2 by tightening the fastener 6 using a ratchet wrench or the like, and a lateral prestress is applied to the concrete structure Q by a compressive force from the surroundings. .
As a result, the concrete is brought into the state of cohesion and re-aggregation and RC
(Reinforcing bar concrete) Enhances the original strength.

Thereafter, the band-shaped tightening member 2 gradually hardens to the inside of the impregnated resin portion with the passage of time, the concrete re-cohesion state becomes permanent, and the concrete structure Q is collapsed from aftershock. protect. In the case of a healthy concrete structure, the occurrence of cracks can be suppressed, which is effective for preventive maintenance.

FIG. 5 is a perspective view for explaining an embodiment in which a tightening work of the present invention is applied to a prismatic concrete structure, and FIG. 6 is a sectional view taken along the line BB of FIG. I have.

In the case of the tightening work of the prismatic concrete structure, the band-like tightening member 2 is provided around the concrete structure Q.
7, a supporting member 8 is interposed at a position of the band-shaped tightening member 2 facing the corner 7 of the concrete structure Q, and the supporting member 8 is tensioned by the tension T of the band-shaped tightening member 2, as shown in FIG. , A compressive force P is applied to the concrete structure Q from the surroundings, and a lateral prestress is applied to the concrete structure Q.

EXAMPLE Aramid fibers were sewn to form a hanging belt 1 having eyeglass-shaped joint locking portions 3 and 3 'at both ends, and this was made of a ketimine latent curing agent (* 1) and a bispheno resin. The belt-shaped tightening member 2 was obtained by dipping in a water diffusion hardening type liquid resin composed of a liquid A type liquid epoxy resin (* 2). (* 1) Condensate of norbornanediamine and methyl isopropyl ketone (* 2) Epoxy equivalent 190, viscosity about 60 poise (EP-4
100, ADEKA RESIN (Asahi Denka Kogyo)) Here, the hanging belt 1 is a spectacle-shaped joint locking portion 3,
It is sewn so as to have a uniform cross-sectional shape with a width of 80 mm and a thickness of about 5 mm except for the 3 'portion, and a linear density of 250 g / m.
Met.

The belt-shaped tightening member 2 is taken out of the liquid resin, the excess resin is dripped, and placed on a wire mesh-shaped saw, and placed in a laboratory room (room temperature 20 ° C., humidity 60%).
Left for hours. The weight of the band-shaped tightening material 2 was increased to 600 g / m due to impregnation with the resin.

After 16 hours, the surface of the band-shaped tightening member 2 lost its tackiness and was hardened, but the band-shaped tightening member 2 itself maintained flexibility, and was easily bent by hand and bent when released. Had been kept in a state.

When the band-shaped tightening member 2 was cut and the cross section was observed, the surface was near the surface in a dry state like skin, but the liquid resin bleed out from the portion near the center.

Further, the same observation was continued for one week, two weeks, one month, and six months from the beginning, and the same observation was performed, and the results shown in the following [Table 1] were obtained. .
Thickness and linear density of the fiber assembly constituting the belt-shaped tightening member 2,
Although the timing suitable for the molding process of the prepreg obtained by the present invention naturally varies depending on the content of the resin to be impregnated therein, the storage conditions after the resin impregnation, and the like, the results of Table 1 show that In the case of, after the resin was impregnated and allowed to stand in air at room temperature for 16 hours,
It was found that the time after about a week was a suitable time for workability without impairing the flexibility of the prepreg.

[0045]

[Table 1]

[0046]

The prepreg of the present invention is excellent in flexibility but has no stickiness on the surface, so that materials are not adhered to each other during processing such as lamination, and the workability is excellent. Therefore, the stability of the quality of the molded product is guaranteed.

Further, in storing, transporting, and using the sheet material, it is not necessary to take up the sheet material with a release paper or the like interposed therebetween, so that it is not necessary to dispose of the waste material after use.

Further, by selecting the type or amount of the latent curing agent to be added to the resin impregnated in the fiber reinforcing material, the time until curing can be adjusted.

On the other hand, the method for producing a prepreg of the present invention is advantageous because a special treatment step is not required for curing the adhesive surface, and the storage method is selected according to the use time of the prepreg. By doing so, the time of curing the prepreg can be selected.

In the method for tightening concrete structures according to the present invention, several kinds of belt-like tightening members having different lengths are prepared in advance in order to enable tightening work corresponding to various column shapes. By doing so, emergency response is possible, and by leaving the concrete structure after construction in the air at room temperature, it is possible to permanently secure the tightening force over time.

[Brief description of the drawings]

FIG. 1A is a plan view of a hanging load belt formed by sewing a fiber assembly, and FIG. 1B is a plan view of a belt-shaped tightening member formed by impregnating the belt with a resin composition.

FIG. 2 is a part of a perspective view for explaining an embodiment in which a tightening work of the present invention is applied to a columnar concrete structure.

FIG. 3 is a sectional view of the columnar concrete structure of FIG.

FIGS. 4A and 4B are a plan view and a front view of a connecting portion in a state where the belt-shaped tightening member of the present invention is connected.

FIG. 5 is a part of a perspective view for explaining an embodiment in which the tightening work of the present invention is applied to a prismatic concrete structure.

FIG. 6 is a cross-sectional view of the prismatic concrete structure of FIG.

FIG. 7 is a partially enlarged explanatory view showing one embodiment of a corner portion of the concrete structure when the tightening work of the present invention is applied to the prismatic concrete structure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Suspension belt 2 Belt-shaped tightening member 3 Joint locking part 4, 4 'Support member
4a Through-hole 5 Fastening means 6 Fastening metal 7 Corner 8 Supporting member Q Concrete structure

Continued on the front page F-term (reference) 2E176 AA04 BB29 4F072 AA01 AA07 AB05 AB06 AB09 AB10 AB28 AB29 AD28 AE01 AF27 AG03 AG12 AH02 AH31 AJ04 AK02 AL17 4J002 CD05W CF00X CL00X CL06X DA016 DL006 ER007 FA04X FA046 FD01

Claims (9)

[Claims] 1. A molding material in which a fiber reinforcing material is impregnated with a resin composition that diffuses and cures at room temperature in the air, wherein the surface of the molding material is cured and the interior is uncured. A cold diffusion hardening prepreg composed of: 2. The room temperature diffusion-curable prepreg according to claim 1, wherein the resin composition is a composition obtained by blending a latent curing agent with a resin. 3. The room temperature diffusion-curable prepreg according to claim 2, wherein the latent curing agent contains ketimine as a main component. 4. A room temperature in which a fiber reinforcing material is impregnated with a resin composition which diffuses and hardens in the air at room temperature to form a molding material, and the molding material is left at room temperature to cure the surface. A method for producing a diffusion-curable prepreg. 5. A molding material is formed by impregnating a fiber reinforced body with a resin composition which is diffusion-hardened at room temperature in the air, and this molding material is stored in a state of being shielded from the outside air, and immediately before use of the molding material. A method for producing a room-temperature diffusion-curable prepreg, in which the molding material is opened to the atmosphere and left in air at room temperature to cure the surface. 6. When the molding material is shielded from outside air and stored, the molding material is cooled to freeze the resin composition, and the molding material is released to the atmosphere immediately before use of the molding material. 6. The method for producing a room-temperature diffusion hardening prepreg according to claim 5, wherein the molding material is thawed prior to the thawing. 7. A belt-shaped tension by sewing a fiber assembly to form a suspended belt having joint engaging portions at both ends, and impregnating the suspended belt with a resin composition that is diffusion-hardened at room temperature in the atmosphere. After forming the member, the band-shaped tension member is left in the atmosphere at room temperature to cure the surface, and the band-shaped tension member is wound around a concrete structure to tighten both ends of the joint locking portion. A method for tightening concrete structures which is fastened and fixed around concrete structures by means of fastening. 8. A belt-shaped tension by sewing a fiber assembly to form a suspended belt having joint locking portions at both ends, and impregnating the suspended belt with a resin composition that is diffusion-hardened at room temperature in the atmosphere. After forming the member, after that, the band-shaped tension member is shielded from the outside air and stored, and immediately before construction, the band-shaped tension member is opened to the atmosphere and left at room temperature at room temperature to cure the surface. A method for tightening a concrete structure, in which the band-shaped tension member is wound around the concrete structure, and both ends of the joint locking portion are tightened by tightening means, whereby the periphery of the concrete structure is tightened and fixed by the band-shaped tension member. 9. When the band-shaped tension member is shielded from the outside air and stored, the band-shaped tension member is cooled to freeze the resin composition, and the band-shaped tension member is released to the atmosphere immediately before construction. 9. The method for tightening a concrete structure according to claim 8, wherein the band-shaped tensioning member is thawed beforehand.