JPH0331830B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a reinforcing material used in a waterproofing method for civil engineering and construction, particularly an asphalt waterproofing room temperature method, and more specifically, a reinforcing material made of a fiber sheet mainly composed of specific hydrophilic fibers and lipophilic fibers. This invention relates to a reinforcing material for waterproofing rubber asphalt emulsion coatings. Traditionally, asphalt waterproofing and thermal methods, sheet waterproofing and coating waterproofing methods have been used as waterproofing methods for civil engineering and construction, but the majority of them are based on the asphalt waterproofing and thermal method due to its reliability, waterproofness, and durability. The current situation is that it depends on However, with this thermal method, the asphalt must be heated and melted at a construction site where there are many flammable materials such as paint, which poses a high risk of fire and human health, and the odor and smoke generated during heating and melting are harmful to urban areas. It is prone to pollution problems, and if the asphalt's heat retention properties and pot life are incorrectly adjusted, it will result in a waterproof layer with poor watertightness, making it highly dependent on skilled workers. Therefore, in recent years, an asphalt waterproof room-temperature lamination method using rubber asphalt emulsion has been proposed and has been implemented in some cases, but the rubber asphalt emulsion used as the adhesive is 20 to 50% by weight.
It has been pointed out that rubber asphalt emulsions used as adhesives have disadvantages such as the fact that the adhesive itself is thin and has poor filling properties, and the waterproof layer tends to swell. There is a strong need for improvements in curing methods. Curing methods for such rubber asphalt emulsions include physical curing by natural drying, chemical curing using a hydration reaction by mixing a hydraulic inorganic substance such as cement, and chemical curing by mixing a water-reactive substance such as an isocyanate compound. Examples of methods include physical hardening, chemical hardening by mixing different types of ions, and neutralization and coagulation with inorganic acids and alkalis. In this case, workability decreases,
In addition, the hydration reaction progresses over time, increasing the cohesiveness of the paint film and impairing its deformability.In the method, it gels instantaneously, making it extremely difficult to work with, and it has poor alkali resistance, making it difficult to apply to concrete substrates. However, it is difficult to work with because it gels instantaneously, and the particles become coarser, which reduces the watertightness of the coating film.
All of them have inherent problems that need to be improved. On the other hand, the coating film waterproofing method is gaining a stable position in the small area new construction and repair fields due to its ease of on-site construction and the ability to waterproof deformed roofs with complex shapes. Emulsions such as rubber-based, acrylic rubber-based, chloroprene rubber-based, and rubber asphalt-based emulsions are used.
Among these, rubber asphalt emulsions have the advantages of being inexpensive and having good adhesion to various substrates. There is also a strong need for improvement. As a result of intensive studies to overcome this defect, the present inventors found that a fiber sheet made of specific fibers can effectively cure rubber asphalt emulsion when used as a reinforcing material. The present invention was completed based on the discovery that a waterproof layer with excellent watertightness and no thinning can be formed in a short period of time, and that the fiber sheet can significantly improve the strength of the waterproof coating layer. That is, an object of the present invention is to be able to effectively harden a rubber asphalt emulsion, to coagulate a high concentration rubber asphalt emulsion even on rising surfaces and ceiling surfaces, and to quickly absorb moisture in the emulsion. The object of the present invention is to provide a reinforcing material for waterproofing rubber asphalt emulsion coatings, which can rapidly cure the emulsion to exhibit fixing properties in a short period of time, and can significantly improve the strength of the resulting waterproof coating layer. Another object of the present invention is to provide a reinforcing material that is free from skinning and thinning, guarantees uniform thickness, and can easily form a thick waterproof coating layer. Another object of the present invention is to form a waterproof layer that does not swell without the risk of moisture interfering with the adhesion between the paint film and the substrate, and to dramatically improve the performance of waterproofing the paint film due to its excellent water absorption and hardening properties. The object of the present invention is to provide a reinforcing material that can shorten the construction period. In order to achieve the object of the present invention, the rubber asphalt emulsion-based waterproof reinforcing material for paint films according to the present invention contains carboxyl groups of 0.1 mmol/g or more and has a neutralization degree of 75%. It is made of a fiber sheet containing 0.5 to 80% by weight of hydrophilic fibers as follows and 20% by weight or more of lipophilic fibers having excellent affinity with rubber asphalt. Although it is not clear why the use of the fiber sheet according to the present invention as a reinforcing material for rubber-asphalt emulsion-based waterproof coatings produces particularly remarkable effects that are completely different from conventional techniques, it is possible to increase the degree of neutralization.
When using fibers with a content of more than 75%, the emulsion is cured only by the water absorption capacity of the fibers. The acid type carboxyl group (-COOH) present in the fibers promotes the coagulation of the rubber asphalt emulsion, and the hydrophilic fibers simultaneously absorb and capture the water that oozes out due to the coagulation. It is possible to cure the emulsion more effectively, and in the end, a waterproof coating layer is formed that does not become skinned or thin, has a dense and uniform thickness, and has further improved strength characteristics. I think that the. The present invention will be explained in detail below. First, the hydrophilic fiber, which is an essential component in forming the fiber sheet of the present invention, has a content of 0.1 m mol/g.
contains the above carboxyl group, and the degree of neutralization of the carboxyl group is 75% or less, preferably
As long as it is 10 to 70% fiber, it can be used without any restrictions, but acrylonitrile (Hereafter AN
) system fibers with crosslinking and 0.1 m mol/g or more,
Preferably, 0.3 to 4.0 mmol/g of carboxyl groups are introduced, and 75% or less of the carboxyl groups are neutralized to become alkali metal or ammonium salt type carboxyl groups, and at least one of the fiber outer layer portions is preferably introduced. It is preferable to use fibers in which part of the fiber is made of a hydrophilic crosslinked polymer (hydrogel) and the remainder is made of an AN polymer and/or other polymer. There are no limitations on the method for producing such fibers, but for example,
-As described in Publication No. 138693, AN-based fibers,
If a high concentration alkali metal hydroxide aqueous solution of 6.0 mol/1000 g or more or a low concentration alkali metal hydroxide aqueous solution coexisting with electrolyte salts of 0.5 mol/1000 g or more is used, no crosslinking agent should be used. capable of hydrogelating the AN-based polymer present in at least a part of the outer layer of the fiber without using it;
Next, the carboxyl groups in the fibers are treated with an acid to a predetermined degree of neutralization, or once the carboxyl groups in the fiber are treated with an acid to a degree of neutralization of 0%, and then treated with alkali metal water to a predetermined degree of neutralization. It can be industrially advantageously produced by neutralizing with an oxide aqueous solution or ammonia. For the above AN-based fibers, it is preferable to use fibers consisting of a single component of AN-based polymers, but the polymer forming the fibers contains 30% by weight or more, preferably 50% by weight or more of AN bonded. As long as the The fibers may be composite spun fibers such as a bonded type fiber or a sandwich type fiber, or a fiber made from a mixed polymer of the above-mentioned polymers. Note that the above-mentioned hydrophilic fibers do not need to be individual fibers with a single degree of neutralization, but may be a mixture of two or more types of fibers with different degrees of neutralization, as long as the degree of neutralization is set within a predetermined range. Even if it is an article, it does not depart from the scope of the present invention. By setting the degree of neutralization within the range according to the present invention, the rubber asphalt emulsion can be effectively coagulated, and the water in the emulsion can be quickly absorbed and cured, resulting in a waterproof coating film that is dense and has excellent physical properties. layers can be formed. In addition, lipophilic fibers can be used as long as they have excellent affinity with rubber asphalt, but it is preferable that a polymer component with a melting point of 200°C or lower, more preferably 150°C or lower, be present at least on the fiber surface. By using heat-adhesive conjugate fibers as a part of the fibers, it is possible to produce sheets with excellent bulkiness and shape retention, thereby improving the permeability of rubber-asphalt emulsions. It is desirable because it is possible to form a thick waterproof coating layer with a uniform thickness without thinning. Polymers constituting such lipophilic fibers include polyethylene, polypropylene, polystyrene, polyester, polyamide, etc. Among them, for example,
Preferably, the heat-adhesive conjugate fibers containing polyethylene as the first component and polypropylene as the second component are disclosed in Japanese Patent Publication No. 15684, Japanese Patent Publication No. 54-44773, and the like. The proportion of hydrophilic fibers contained in a fiber sheet formed mainly of the above-mentioned hydrophilic fibers and lipophilic fibers is determined by the amount of carboxyl groups bonded and contained in the fibers, the degree of neutralization of the carboxyl groups, the rubber It is determined appropriately depending on the water content in the asphalt emulsion, etc., and it is difficult to set it uniquely, but it is generally within the range of 0.5 to 80% by weight, preferably 2 to 30% by weight, and the lipophilic fiber is 20% by weight or more,
It is necessary to set it preferably within the range of 70 to 98% by weight, and this configuration improves various performances such as the water absorption performance of the fiber sheet, the permeability of the rubber asphalt emulsion, and the strength of the waterproof coating layer finally obtained. This is desirable because it improves overall. In addition,
In addition to the above two types of fibers, pulp, if desired,
It goes without saying that other fibers such as cotton, rayon, polyvinyl alcohol, polyester, polyamide, acrylonitrile, and the like can be mixed. Examples of the form of the above-mentioned fiber sheet include non-woven fabric, woven fabric, knitted fabric, etc., but the basis weight is 30~
In order to achieve the object of the present invention, a 100 g/m ² nonwoven fabric, particularly a dry nonwoven fabric in which joints are provided by thermally melting lipophilic fibers made of heat-adhesive conjugate fibers, is desirable. Suitably, such a fiber sheet has a water swelling degree of 0.5 times or more, preferably 1 to 50 times.
If the lower limit of this range is exceeded, it is difficult to effectively cure the rubber asphalt emulsion to form a waterproof layer that is free from thinning and has excellent watertightness. The rubber asphalt emulsion to which such a fiber sheet reinforcing material is applied is not limited in any way, but it is preferable to use one with a rubber asphalt solid content concentration of 50% by weight or more, more preferably 80% by weight or more. This is desirable because the emulsion cures rapidly, does not cause skinning or thinning, and can form a thick waterproof coating layer with a small number of coatings. The application ratio of the fiber sheet reinforcing material to the rubber asphalt emulsion is based on the amount of carboxyl groups in the hydrophilic fibers and the degree of neutralization of the carboxyl groups, the degree of water swelling of the fiber sheet reinforcing material, and the amount of carboxyl groups in the rubber asphalt emulsion. It is appropriately set depending on the moisture content, the required strength of the waterproof coating layer, etc. The fiber sheet reinforcing material as described above allows the rubber asphalt emulsion to be effectively cured, and the rubber asphalt emulsion can be cured uniformly without causing problems such as skinning, thinning, or swelling caused by moisture in the emulsion.
A characteristic advantage of the present invention is that it is possible to form a waterproof coating layer that is thicker and has improved strength. Furthermore, due to the excellent water absorption and curing ability of such reinforcing materials, it can be applied to rising surfaces and ceiling surfaces in the same way as floor surfaces, and the construction period for waterproofing coatings can be significantly shortened. It is an effect. Examples of the present invention are shown below, in which all percentages and parts are based on weight unless otherwise specified. The degree of water swelling, amount of carboxyl groups, and curing time described in the Examples were measured or calculated by the following methods. (1) Degree of water swelling (times) Approximately 0.1g of the test piece was immersed in pure water and kept at 25℃.
After 24 hours, it was wrapped in nylon cloth (200 mesh) and the water between the fibers was removed using a centrifugal dehydrator (32G x 30 minutes, where G is gravitational acceleration). Measure the weight of the sample prepared in this way (W ₁ g). The sample is then dried in a vacuum dryer at 80° C. to a constant weight and weighed (W ₂ g). It was calculated from the above measurement results using the following formula. Therefore, the water swelling degree is a numerical value indicating how many times the weight of the fiber or textile product can absorb and retain water. (Water swelling degree) = W ₁ − W ₂ /W ₂ (2) Amount of carboxyl groups (m mol/g) Approximately 1 g of a sufficiently dried sample was accurately weighed (Xg), and 200 ml of water was added to it. While heating to 50℃
Add 1N hydrochloric acid aqueous solution to bring the pH to 2, then
A titration curve was determined using a 0.1N caustic soda aqueous solution according to a conventional method. The amount of caustic soda aqueous solution consumed by carboxyl groups (Yc.c.) was determined from the titration curve. From the above measurement results, it was calculated using the following formula. (Amount of carboxyl group)=0.1Y/X If polyvalent cations are included, it is necessary to determine the amount of these cations by a conventional method and correct the above formula. (3) Curing time (minutes) Add 0.3 of the sample fiber (fiber length: 3 mm) to 100 g of Emulcoat G (high-concentration rubber asphalt emulsion manufactured by Nichirei Kagaku Kogyo Co., Ltd., solid content: 85%) in a glass beaker. After stirring and mixing while adding g, the mixture was sealed and left at a temperature of 20°C, and the time (minutes) at which the container did not deform even if the container was tilted was determined. Reference example 1 Lanseal (3D manufactured by Nippon Exlan Kogyo Co., Ltd.)
Hydrochloric acid aqueous solution was added to the water-swellable fiber, water swelling degree 150 times, -COONa group content: 1.9 m mol/g) until the pH reached 2 to convert the carboxyl groups into the acid form (-
COOH), a predetermined equivalent of a caustic soda aqueous solution was added and neutralized to obtain a predetermined degree of neutralization, and seven types of test fibers (a to g) were prepared. The results of measuring the curing time are shown in Table 1 below.
In addition, when measuring the curing time, Table 1 also shows the results of visually determining the amount of water seeping out at the interface with the glass after one day of standing.

[Table] From the results in the above table, it is understood that the hydrophilic fiber according to the present invention has excellent curing ability. In addition, when the present invention is lowered (particularly No. 1), the curing time is shortened, but oozing water is observed. Example 1 Reference Example 1, 10 parts of No. d hydrophilic fiber (7d x Varicut) and ES fiber (polyethylene-polypropylene heat-adhesive composite fiber manufactured by Chitsuso Co., Ltd.: melting point 135°C: 10d x 51 mm) 90 Put the cards between the club and
A web of 50 g/m ² was prepared and dried at 145° C. for 10 minutes to produce a nonwoven fabric (I) having a water swelling degree of 16 times. Apply 15% styrene-butadiene latex diluted with water as a primer to the roof mortar surface at a rate of approximately 0.3 kg/ ^m2 , and after drying, apply Emulcoat G at a rate of approximately 0.7 kg/ ^m2 . While doing so, the nonwoven fabric (I) was poured and pasted. The emulsion was stored at 20℃ and 65%RH.
After 10 minutes, the mixture coagulated and the nonwoven fabric (I) was adhesively fixed to the base. Next, Emulcoat G was coated and impregnated on the fixed nonwoven fabric (I) at a rate of 2 kg/m ² , and the impregnation of the emulsion into the nonwoven fabric (I) was good, and after 20 minutes, it solidified and approx. We were able to form a rubber asphalt waterproof coating layer with a thickness of 2.6 mm. The waterproof coating layer had a uniform thickness and excellent watertight filling properties, and did not cause any problem of swelling due to moisture in the emulsion. Example 2 Three types of nonwoven fabrics (~
) was created. Further, two types of nonwoven fabrics (V and ) were prepared in the same manner as in Example 1 except that Nos. e and f were used instead of No. d of Reference Example 1 and the mixing ratio was 5/95. After coating and impregnating 18 g of Emulcoat G on the nonwoven fabric cut into 3 cm x 20 cm, it was heated to 65% at 20°C.
Five types of test pieces (A to E) were prepared by curing in an RH environment for 24 hours, and test piece F was prepared with a thickness of 0.5 mm without using a nonwoven fabric because it did not harden. Note that test pieces D and E were cured in 25 minutes and 30 minutes, respectively. The strength and elongation of the test pieces (A to F) was measured using Instron (10
Table 2 also shows the results measured using a constant speed extension type of ±1 cm/min.

【table】

[Table] From the above table, test pieces according to the present invention (A and D)
is a test piece using hydrophilic fibers with a degree of neutralization of 80%, which has good impregnation and curing properties for rubber asphalt emulsion, and also has a practically satisfactory level of mechanical properties as a waterproof layer. The fact that it is much improved compared to E is clearly understood. On the other hand, in test piece B, Emulcoat G did not impregnate into the nonwoven fabric, and in test piece (C), although the impregnating property was good, the nonwoven fabric did not have curing performance, and both were used for strength and elongation measurement. It was not possible to create a test piece.

Claims (1)

[Claims] 1 0.5 to 80% by weight of hydrophilic fibers containing 0.1 m mol/g or more of carboxyl groups and a degree of neutralization of the carboxyl groups of 75% or less, and 20 weight % of lipophilic fibers that have excellent affinity with rubber asphalt. A reinforcing material for waterproofing rubber asphalt emulsion-based paint films consisting of a fiber sheet containing % or more.