JPS63103852A - Fiber for reinforcing cement - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to fibers for reinforcing cement having excellent bending strength in fiber-reinforced cement composite materials.

[Prior art]

When reinforcing cement with continuous edge a, conventional
The λ method in which m bundles are arranged in one direction for reinforcement, and the method in which the materials are processed into a net, wood fiber, or woven fabric and laminated for reinforcement are known. All of the fiber bundles are impregnated with synthetic resin such as epoxy resin to effectively utilize the tensile strength of the fibers.

[Problem that the invention seeks to solve]

However, the synthetic resin that coats the fiber bundles has poor adhesion to cement, and 0-slips occur at the interface, so it cannot be used as a cement composite material.

It was not possible to sufficiently obtain the reinforcing effect of kfl fibers.

[Means for solving problems]

Therefore, as a result of intensive studies to solve the conventional problems, we found that by providing a coating layer with a specific composition on the reinforcing fiber bundle, the adhesion between S cement and the reinforcing fiber bundle was improved, and the outer coating was improved. p due to the laminate having specific tensile properties,
The present invention was achieved based on the finding that the reinforcing effect is improved.That is, the object of the present invention is to improve the adhesion between cement and reinforcing fibers and to provide cement reinforcing fibers having excellent bending strength. It is something.

The purpose is to impregnate organic or inorganic continuous fibers with synthetic resin, and then achieve a tensile strength of 2 ook in the cured state.
g/cI or more, Young* / 00-700 kg /
(This is easily achieved by cement reinforcing fibers obtained by encapsulating and curing an elastomer having a ratio of 7/l.

The present invention will be explained below. The organic or inorganic continuous fibers used in the present invention are not particularly limited, but examples include organic fibers such as nylon, polyester, and rayon.

Aromatic fibers such as aramid are used, and inorganic fibers such as glass fibers, carbon fibers, and graphite fibers are used.

Among these, tensile strength/jOkg/sJ or more, Young's modulus 10
It is preferable to have a temperature of ℃on/- or more. The fibers may be pretreated with surface treatments, finishing agents, and the like.

Next, the synthetic resin used for the impregnation treatment of the present invention may be water-soluble or non-water-soluble.

A known one is used. For example, epoxy compounds, unsaturated polyesters, polyimides, diallyl phthalates, etc. are preferable, but thermosetting resins are preferable, but room temperature curing resins that use a hard surface may also be used. Such synthetic resin.

It is used as an emulsion by dissolving or emulsifying it in water, or as a solution using an organic solvent.

Next, as the elastomer used in the coating treatment of the second treatment of the present invention, natural rubber, synthetic rubber, urethane, thermoplastic resin, etc. are used, and among these, tensile strength of 20
0kQ/Cr11 or more, Young'FIX/00-j
Preferably, it is in the range of 00 kq/cd. If the tensile strength is too low, the elastomer layer will deform significantly if the Young's modulus is too low, and it will be difficult to transfer the fiber bundle strength to the cement structure. On the other hand, if Young's modulus is too high.

If the fiber bundle is not stiff, stress concentration tends to occur and the toughness decreases.

Such an elastomer, like the synthetic resin used in the first treatment, can be used in the form of an emulsified dispersion or a solution using an organic solvent.

Note that, if necessary, a compounding agent such as a vulcanizing agent (crosslinking agent) may be added to the elastomer.

As a method of subjecting the long fibers to the first treatment and second treatment, 1. In the first treatment with a synthetic resin, fl! After soaking the fiber, it is hardened by passing it through a heat treatment tank using a squeezing roller etc., and the heat treatment temperature is usually 70℃ or higher, 12℃.
Do this for about 30 minutes at 0°C or below. If you want to further improve the fiber bundle strength, /! The heating may be carried out at a temperature of θ°C or higher and 200°C or lower for about 1 hour. When using room temperature curing resin,
After impregnating, leave it at room temperature for a certain period of time to harden. No matter which resin is used, it is preferable to perform the second treatment while the resin is still in a semi-cured state, which is convenient from the point of view of handling and the like.

Next, in the second treatment, the FA fibers are immersed in an elastomer emulsion or solution bath, and similarly to the first treatment, they are passed through a heat treatment bath through a squeezing roller or the like and hardened. The heat treatment temperature is preferably 700° C. or higher and 200° C. or lower with a 7-y40 tolerance.

If the heat treatment temperature was too low in both the first treatment and the second treatment, and the curing time was too short, the fiber bundle strength would be insufficient and the bending strength of the cemented composite material would decrease.

On the other hand, if the heat treatment temperature is too high, the resin and elastomer will change in quality and deteriorate, resulting in decreased adhesion with cement.

What is the amount of N applied to the fibers? 0 to J, 00 weight S is preferred. If the amount of resin-attached N is too large, cohesive failure is likely to occur due to uneven adhesion, and if the amount of -force adhesion is too small, the fiber bundles will not be strongly embedded, resulting in a decrease in the bending strength of the cement composite material. In addition, the adhesion formula of the cured elastomer to the fiber is 70~
200% by weight 1% Preferably, JO to ioo weight S is preferably used. If the amount of elastomer attached is too large, the M of the elastomer is one layer? Collision and fracture are likely to occur, and on the other hand, if the amount of M is too small, adhesion with cement will be reduced.

The cured product of resin and elastomer usually covers the entire fiber, but it may cover only a portion of the fiber as long as it does not impair the effects of the present invention.

The above-treated nine fibers can be used in the form of long fibers (strands), sheets, non-woven fabrics,
Can be used in the form of textiles, etc.

Construction methods such as impregnation method (or hand lay-up method) and paper making method are used.

Also, Portland cement, blast furnace cement.

It can be mixed with various hydraulic cements such as alumina cement and calcium silicate to produce fiber-reinforced cement materials in various shapes such as plates, tubes, and columns.

The amount of fiber to be used is determined to obtain the desired strength properties. Usually a dry form of cement xio.

Based on parts by weight, O-5 to i parts by weight are desirable.

The amount of water required for this is usually 20 to 70 parts by weight per dry weight of cement/00 parts by weight.In order to increase the strength of the cement structure as much as possible, it is preferable to mix 30 to +1 parts by weight of water. Furthermore, a "mortar" containing 700 parts by weight of cement and jO-λ00 parts by weight of sand, silica sand, etc. may be used as an aggregate.

〔Example〕

The present invention will be specifically described below by way of an example, but the present invention is not limited to the following example as long as it does not go beyond the gist of the invention.

Example 1 Tensile strength -00kg/xi, Young "X 4'
Using a pitch-based carbon fiber bundle (co000 filament: length JOcm) of or, on /-, it was impregnated in a methyl ethyl ketone solution containing an epoxy resin (thermosetting type) with a concentration of jON, and then heated to 20 minutes more /
Dry at 0°C for 20 minutes and heat treat? The applied resin was cured. Subsequently, it was treated with self-crosslinking styrene-butadiene rubber latex (T, to 5b solid content, manufactured by Nippon Zeon).

The rubber was cured by heat treatment at 710° C. for 70 minutes. Table 1 shows the tensile properties of the cured film obtained by heat-treating the latex.

What is the amount of N attached to resin and rubber to carbon fiber?

Each /3j weight 9, 7! % by weight. The obtained carbon fiber bundles were mixed with 11 parts of cement and 11 parts of water rz% sand according to the conventional method of hand lay-up, which is a method for manufacturing fiber-reinforced cement materials.

in a cement matrix consisting of each part by weight of

The carbon fiber bundles were stretched at regular intervals to arrange io carbon fiber bundles. Next, air curing (temperature 20"c1 relative humidity 2x
), and a carbon fiber reinforced cement material was obtained after 7 days of age.

The obtained carbon ui fiber reinforced cement material was subjected to a bending test under the following conditions.

Specimen dimensions: Vertical 3 bars Width μ country, Thickness 2 pieces Between spans:
2ttx Cover thickness; 0-Jctx Three-point bending test method: Average value of three test specimens The bending properties are shown in Table 2.

Example 7 Using the same carbon fiber bundle as in Example 7, it was impregnated with a methyl ethyl ketone solution containing a room temperature curing epoxy resin with a JOX concentration, and then allowed to stand at room temperature day and night to be cured.

Table 2 below shows the physical properties of the carbon fiber reinforced cement material obtained in the same manner as in Example.

Note that the adhesion amounts of the room temperature curing epoxy resin and rubber were ii, o, iX, and A4 iX, respectively, relative to the carbon fiber.

Example 3 Using the same carbon fiber bundle as in Example 3, it was impregnated with a methyl ethyl ketone solution containing a thermosetting epoxy resin with a concentration of 100 °C, and then dried and heat-treated at 10 °C for 20 minutes and further at 130 °C for 30 minutes. The resin was cured. Subsequently, 3.0 parts of colloidal sulfur was added to 100 parts by weight of the rubber solid content. Zinc flower! , acrylonitrile butadiene rubber latex (solid content μj
Table 1 shows the tensile physical properties of a cured (vulcanized) film obtained by heat treating the latex, which was heat treated at 0°C for 3 days to cure (add) the rubber.

Table 2 below shows the physical properties of the large carbon fiber reinforced cement material obtained in the same manner as in Example.

In addition, the amount of resin and rubber adhered to carbon fiber is as follows:
/2F weight was 3.11% by weight.

Example 4 Using the same carbon fiber bundle as in Example 2, methylolated melamine resin was treated with 11 k'r to a rubber solid content of 10θi.
Against the t section! Table 2 shows the physical properties of the carbon fiber-reinforced cement material obtained in the same manner as in Example 1, except that it was coated with a nine-carboxyl modified acrylate latex (solid content μ/liter).

The tensile properties of the cured latex film were as shown in Table 1, and the amounts of resin and rubber adhered to the carbon fibers were /&Kokyo weight % and weight S, respectively.

Comparative Example/ Using the same carbon fiber bundle as in Example 1, it was impregnated with a methyl ethyl lactone solution containing a thermosetting epoxy resin at a zoyy concentration and heated to ℃ for 20 minutes including the first step.

The resin was cured by drying and heat saturation at -0°C for 1 hour and at -00°C for 1 hour. below.

Table 2 shows the physical properties of the carbon fiber-reinforced cement material obtained by pouring it into cement and curing it in the same manner as in Example.

In addition, the attachment Mik of the resin to the carbon fiber is /10 weight iX
Met.

Comparative side Using the same carbon fiber bundle as in Example 1, in the second treatment, 3.0 parts of colloidal sulfur was added per 100 parts of rubber solid content. Zinc flower!
, sulfenamide vulcanization accelerator/
Dispersed. Table 1 shows the physical properties of a carbon fiber-reinforced cement material obtained in the same manner as in Example 3 except that it was coated with styrene-butadiene rubber latex (solid content θ%).

The amount of fat and rubber deposited is l≠O weight, respectively.

It was a 7z heavy JIX.

Comparative Example 3 Using the same carbon fiber bundle as in Example, in the second treatment, colloidal sulfur λ, zinc white,
2. Dithiocarnocoumate vulcanization accelerator O6! Mix and disperse each part by weight.

Acrylonitrile butadiene rubber latex (solid content a
Table 2 shows the physical properties of the carbon fiber reinforced cement material obtained in the same manner as in Example 3, except that it was coated with JN).

The amount of fat and rubber deposited is /! μ weight xi%.

The weight was r7.

[Preparation and measurement method of latex cured film] Use the latex as a undiluted solution, or for latex that requires compounding agents such as a vulcanizing agent, mix and disperse the compounding agents, pour it onto a glass plate, and leave it at room temperature. , cured (vulcanized) from J 1. A tensile test was performed according to the measurement method specified by JO/.

Table 2 [Effects of the Invention] - It was found that the fiber-reinforced cement material using the 7-ment reinforcing fiber of the present invention has excellent bending strength not found in conventional reinforced cement materials. Further, by applying the treatment of the present invention, it has a corrosion-proofing effect against the water and alkalinity of cement, so it has the advantage of being able to use steel and glass fiber.

According to the present invention, the reasons why the eroded bending strength appears are as follows: 1. By coating the outside of the fiber bundle impregnated with synthetic resin with a rubber layer, the adhesion to cement increases, and the rubber layer has specific tensile properties, so it does not lead to cohesive failure,
Therefore.

Stress concentration is less likely to occur in the resin layer. As a result, it is thought that the fiber bundle strength works effectively to increase the 1-bending strength.

Claims (1)

[Claims] (1) Organic or inorganic continuous fibers are impregnated with a synthetic resin, then coated with an elastomer having a tensile strength of 200 kg/cm^2 or more and a Young's modulus of 100 to 500 kg/cm^2 in the cured state, and cured. The resulting fiber for reinforcing cement.