JPH08157553A - Improved asphalt composition - Google Patents

Abstract

PURPOSE: To provide an improved asphalt composition excellent in dryability and curability, with the result of excellent workability in application, and also excellent in waterproofing and water stopping. CONSTITUTION: This composition is obtained by adding 0.05-40 pts.wt. polyisocyanate compound having reactive isocyanato groups to 100 pts.wt. (solid content) asphalt emulsion having a total solid content of 60-90wt.% and produced by adding 25-97.99wt.% heat melted asphalt to a mixture of 2-70wt.% latex of a polymer having a glass transition temperature of -80 to +10 deg.C and 0.01-5wt.% surfactant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a modified asphalt composition, and more specifically to an asphalt emulsion obtained by adding molten asphalt to a polymer latex.
The present invention relates to a modified asphalt composition containing a polyisocyanate compound, which is useful for a wide range of applications including a waterproof material for various structures and a water blocking material.

[0002]

2. Description of the Related Art Waterproofing used for civil engineering such as rooftops of concrete buildings, industrial waste disposal sites, underground structures, etc.
Water-stopping materials are mainly asphalt and polymer latex asphalt emulsions, cement-based polymer cement mortar, polyvinyl chloride resin sheets, and vulcanization of ethylene propylene rubber or styrene butadiene rubber. Rubber sheets, coating materials using urethane polymers, etc. are used.For these waterproof / waterproof materials, construction needs to be done in consideration of the increasing needs for productivity improvement, labor saving, environmental protection, etc. in recent years. Shorter period, less maintenance,
Demands for improvement of waterproof / waterproof performance are becoming more and more strict. However, among the conventional waterproof / waterproof materials, an asphalt emulsion containing asphalt and a polymer latex as a main component has a low drying and curing speed, and thus has poor workability in construction and low adhesion to a substrate. In addition, since the polymer cement mortar has a slow drying and hardening rate and is brittle in terms of material, it cannot be said that its waterproof / waterproof performance is sufficient. In addition, the sheet-like waterproof material such as polyvinyl chloride resin sheet or vulcanized rubber sheet has poor adhesion to a stepped base, which may result in insufficient waterproof / waterproof performance, and may cause heating of the sheet. It is a drawback that it has poor safety and workability when it is adhered to the substrate. Furthermore, the coating material using the urethane-based polymer has poor dimensional stability of the coating film, and as a result, is unsatisfactory in terms of waterproof / waterproof performance. Moreover, these waterproof / waterproof materials are usually laminated and coated in order to improve waterproof / waterproof performance.
The stacking process takes time, which is a major problem from the viewpoint of productivity and labor saving. Further, a curable composition in which a water-soluble polyisocyanate is mixed with a cement-containing bitumen emulsion obtained by adding cement to a bitumen emulsion such as asphalt has been proposed (see Japanese Patent Publication No. 59-38990). Since it uses the hardening reaction of cement, it takes, for example, 24 hours or more to sufficiently harden the cement, and the above-mentioned problems concerning workability have not yet been solved. Therefore, today, there is a strong demand for the development of a waterproof / waterproof material that is satisfactory in terms of both workability and waterproof / waterproof performance.

[0003]

The present invention has been made on the basis of the above-mentioned technical problems, and is excellent in dry-curing property, and as a result, the lamination coating time is short and the workability is excellent.
It is also an object of the present invention to provide a modified asphalt composition which is also excellent in waterproof and waterproof performance.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been found as a result of extensive studies to solve the above problems.
The gist is the glass transition point (hereinafter referred to as "Tg").
2 to 70% by weight of polymer latex at -80 to + 10 ° C
An asphalt emulsion having a total solid content of 60 to 90% by weight obtained by adding 25 to 99.99% by weight of heat-melted asphalt to a latex in which 0.01 to 5% by weight of a surfactant is mixed. A modified asphalt composition comprising 0.05 to 40 parts by weight of a polyisocyanate compound having a reactive isocyanate group with respect to 100 parts by weight (solid content).

The present invention will be specifically described below. This will clarify the purpose, structure and effect of the present invention. Examples of the polymer latex used in the present invention include polybutadiene latex, styrene-butadiene copolymer latex, styrene-methylmethacrylate-butadiene copolymer latex, methylmethacrylate-butadiene copolymer latex, acrylonitrile-butadiene copolymer. Polymer latex, chloroprene rubber latex, vinyl chloride latex, vinylidene chloride latex, ethylene-vinyl acetate copolymer latex, acrylate-vinyl acetate copolymer latex, acrylate-styrene copolymer latex, acrylate-ethylene copolymer Rubber latex or resin latex such as latex, silicone-acrylate copolymer latex, olefin latex, polyurethane latex It can be mentioned, also, these polymer latex is a carboxyl group, an amide group, N
It is also possible to have at least one functional group such as a methylol group, a glycidyl group, a hydroxyl group, and a sulfonic acid group.
In the present invention, particularly preferred polymer latexes are styrene-butadiene copolymer latex and carboxyl-modified styrene-butadiene copolymer latex. Tg of the polymer latex is −80 to + 10 ° C.
And preferably -70 to 0 ° C, more preferably-
It is 65--10 degreeC. In this case, if the Tg is less than -80 ° C, the coating strength of the obtained modified asphalt composition is lowered and the stain resistance is insufficient, while if it exceeds + 10 ° C, the coating becomes hard and the cold resistance is low. Is reduced. The Tg of the polymer latex in the present invention was measured under the following conditions using a differential scanning calorimeter (DSC) manufactured by Rigaku Denki Co., Ltd.
Measured in (i) and (ii). (i) About 5 g of polymer latex was thinly drawn on a glass plate and dried at 25 ° C. for 7 days to obtain a polymer film. (ii) The Tg of the obtained dry polymer film is measured under the conditions of a temperature rising rate of 20 ° C./minute, an atmosphere of nitrogen gas, and a sample amount of 20 mg. The solid content of the polymer latex is usually 45 to 75% by weight. In the present invention, the polymer latex may be used alone or in combination of two or more.
The amount of the polymer latex used in the present invention is 2 as solid content based on the asphalt emulsion (solid content).
Is 70% by weight, preferably 3% by weight to 60% by weight, and more preferably 5% by weight to 50% by weight. In this case, when the amount of the polymer latex used is less than 2% by weight, the temperature dependency of the coating film of the finally obtained modified asphalt composition becomes large, and the coating film is likely to swell, and the coating film on the substrate is liable to be blistered. Adhesion also deteriorates, while if it exceeds 70% by weight, waterproof / waterproof performance commensurate with cost cannot be obtained.

Next, as the surfactant to be blended in the polymer latex, fatty acid salt, higher alcohol sulfate, alkylbenzene sulfonate, diphenyl ether disulfonate, dialkyl disulfosuccinate, alkyl phosphate salt, poly Anionic surfactants such as oxyethylene sulfate salts; cationic surfactants such as alkylamine salts, quaternary ammonium salts, polyoxyalkylamines; polyoxyethylene alkyl ethers, polyoxyethylene alkylphenol ethers, sorbitan fatty acid esters, Examples thereof include nonionic surfactants such as polyoxyethylene sorbitan fatty acid ester, polyoxyethylene amine ester, and polyoxyethylene-polyoxypropylene block polymer. Further, the surfactant may be a fluorine-based surfactant whose lipophilic group has a fluorine atom. Of these surfactants, fatty acid salts and polyoxyethylene sulfate salts are preferred. The surfactants may be used alone or in admixture of two or more. The amount of the surfactant used is 0.01 to 5.0% by weight, preferably 0.1 to 4.5% by weight, and more preferably 0.3 to 3.% by weight based on the asphalt emulsion (solid content). It is 0% by weight. In this case, if the amount of the surfactant used is less than 0.01% by weight, the viscosity stability of the asphalt emulsion with time decreases, whereas
If the content exceeds 10% by weight, the water absorption resistance of the resulting modified asphalt composition is reduced, and it becomes difficult to maintain the initial waterproof / waterproof performance.

Next, the asphalt used in the present invention is not particularly limited, and natural asphalt or petroleum asphalt may be used. Examples of such asphalt include slate asphalt, blown asphalt, semi-blown asphalt, etc. containing asphaltene, paraffin, naphthene, aromatic resin or the like as a main component. The amount of asphalt used in the present invention is 25 to 99.99% by weight, preferably 30 to 90% by weight, and more preferably 40 to 80% by weight, based on the asphalt emulsion (solid content). In this case, if the amount of asphalt used is less than 25% by weight, the waterproof / waterproof performance is deteriorated, while 97.9%.
When it exceeds 9% by weight, the temperature dependency of the obtained modified asphalt composition becomes large, and the coating film easily changes with time,
In addition, the elongation at low temperature becomes small, resulting in a brittle coating film.

The asphalt emulsion in the present invention is prepared by adding asphalt heated and melted at 110 to 150 ° C. to a polymer latex to which a predetermined amount of a surfactant has been added, mixing and cooling. . In this way, by adding and mixing the heat-melted asphalt into the polymer latex, the waterproofing / water-stopping performance is particularly improved as compared with the case where the polymer latex is added and mixed in the asphalt emulsion prepared in advance. To be done. The total solid content of the asphalt emulsion in the present invention is 60 to 90% by weight, preferably 65.
˜89% by weight, more preferably 70 to 88% by weight. In this case, if the total solid content is less than 60% by weight, the total solid content of the modified asphalt composition obtained will be low, resulting in a decrease in dry-curability and poor workability for making a laminated coating film. On the other hand, if it exceeds 90% by weight, the viscosity of the asphalt emulsion is likely to change with time, and the viscosity of the asphalt emulsion becomes high, so that the coating suitability of the modified asphalt composition obtained is reduced.

Next, examples of the polyisocyanate compound having a reactive isocyanate group used in the present invention include phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, 4,4'-biphenyl diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, triphenylmethane diisocyanate,
Diisocyanate compounds such as naphthalene diisocyanate, isophorone diisocyanate, cyclohexylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate; biphenyl triisocyanate, diphenylmethane triisocyanate, triphenylmethane triisocyanate, naphthalene triisocyanate Triisocyanate compounds such as isocyanate; polymers thereof, and the like can be mentioned. Further, the polyisocyanate compound in the present invention, the polyisocyanate compound and the polyamine compound,
It can also be used in the form of a prepolymer having a reactive isocyanate group at the terminal obtained by reaction with a polyhydric alcohol, a polyol compound or the like. Examples of the polyamine compound include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenehexamine, pentaethylenehexamine, cyclohexylenediamines, dicyclohexasilmethanediamines,
Examples thereof include isophoronediamines, phenylenediamines, tolylenediamines, xylylenediamines, diphenylmethanediamines, triphenylmethanepolyamines, piperazine and aminoethylpiperazine. As the polyhydric alcohol, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, hexamethylene glycol, diethylene glycol, triethylene glycol,
Examples thereof include glycerin, hexanetriol, trimethylolpropane, pentaerythritol and sorbitol. Further, as the polyol compound, a polyether polyol compound obtained by addition polymerization of the polyhydric alcohols and alkylene oxides such as ethylene oxide and propylene oxide; maleic acid, succinic acid, and adipine with the polyhydric alcohols. Polyester polyol compound obtained by condensation reaction with polybasic acid such as acid, sebacic acid, tartaric acid, terephthalic acid, isophthalic acid; polyester polyol compound obtained by ring-opening polymerization of lactone such as ε-caprolactone, γ-valerolactone An epoxy polyol compound obtained by reacting an epoxy resin having epoxy groups at both ends with an alkanolamine such as monoethanolamine or diethanolamine; 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl ( Homopolymers of hydroxyl group-containing polymerizable monomers such as (meth) acrylate, 4-hydroxybutyl (meth) acrylate, trimethylolpropane (meth) acrylic acid monoester or copolymers thereof; A copolymerizable monomer of, for example, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylonitrile, styrene, α-methylstyrene, or the like; castor oil or a derivative thereof, etc. Can be mentioned. In the present invention, a preferred polyisocyanate compound is a prepolymer obtained by reacting the diisocyanate compound with the polyol compound, and a particularly preferred polyisocyanate compound is a prepolymer obtained by reacting hexamethylene diisocyanate with the polyol compound. It is a water-soluble type polyisocyanate compound composed of a polymer. The polyisocyanate compounds may be used alone or in admixture of two or more. The compounding amount of the polyisocyanate compound in the present invention is 0.05 to 40 parts by weight, preferably 0.1 to 35 parts by weight, and more preferably 0.15 to 100 parts by weight (solid content). 30 parts by weight. In this case, if the blending amount of the polyisocyanate compound is less than 0.05 parts by weight, the dry modified hardenability of the obtained modified asphalt composition is low, it takes time to form a laminated coating film, and the workability is deteriorated. If it exceeds 40 parts by weight, the compatibility with the asphalt emulsion becomes poor, the viscosity of the resulting modified asphalt composition tends to change over time, and the coating suitability deteriorates. In the present invention, the polyisocyanate compound can be blended at an appropriate stage after the preparation of the asphalt emulsion until just before the use of the final composition, but it may be blended immediately before the final composition is used as a waterproof material, for example. desirable.

Further, the modified asphalt composition of the present invention contains, if necessary, a tackifier such as cement, petroleum resin and rosin resin; other bituminous substances such as heavy oil, pitch and tar; calcium carbonate and water. Fillers such as aluminum oxide, magnesium hydroxide, talc, clay, mica, rubber powder, and shirasu balloons; reinforcing materials such as carbon fibers, glass fibers, organic fibers; aggregates such as silica sand, crushed stone, gravel; titanium oxide, carbon Pigments such as black; Antiaging agents such as styrenated phenol, diphenylamine, 2,6-ditertiarybutyl-4-methylphenol; UV absorbers such as hindered amine, benzophenone, benzotriazole; dioctyl phthalate, dibutyl phthalate, polyethylene glycol, Plasticizers such as butyl cellosolve and carbitol acetate; Antifoaming agents such as dimethyl polysiloxane emulsion; ene, xylene, diluents ethyl acetate and methyl trimethoxy silane, vinyl trimethoxy silane,
Alkoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane and γ-methacryloxypropyltrimethoxysilane; crosslinking agents such as zinc oxide, calcium acetate, zirconium acetate, aziridine, and melamine resins; benzisothiazoline, methylisoazoline, Preservatives such as hydrogen peroxide; flame retardants such as antimony trioxide; antifoaming agents such as sodium hydroxide, zeolite, diatomaceous earth, thickeners, protective colloids, etc. can be added later to optimize the properties. it can. The modified asphalt composition of the present invention is a waterproof material used on roofs and walls of above-ground structures such as concrete buildings, wall surfaces of underground structures such as subways and tunnels, slopes and bottoms of industrial waste treatment plants, or the like. Water-stopping material; cement concrete, secondary cement product, ceramics, aggregate, wood, paper, metal, plastic, rubber, glass, fiber, etc., binder, adhesive, protective coating material or grout material, sealing material It is useful as a binder for road paving. When the modified asphalt composition of the present invention is used, for example, as a roof waterproofing material for an above-ground structure, a construction method is as follows. First, a primer such as an asphalt primer is preferably applied to a concrete base, usually about 0.1 to 0.2.
After coating so as to have a film thickness of mm and drying, the modified asphalt composition of the present invention is usually laminated and applied in two batches so that the total film thickness is usually about 5 mm. In this application, an appropriate application means such as a brush or a rubber roller can be used. It should be noted that it is not necessary to particularly heat the coating after drying.

[0011]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. In the examples, parts and% are based on weight unless otherwise specified. Examples 1 to 6 and Comparative Examples 1 to 10 <Preparation of Asphalt Emulsions A to L> Asphalt emulsions A to L were prepared by mixing the materials having the compositions shown in Tables 1 and 2 into a stainless steel container having an internal volume of 1 liter.
Was prepared. In the asphalt emulsions A to K, first, a surfactant and a polymer latex were mixed in a stainless steel container and stirred with a lab stirrer at 300 rpm,
After heating to 50 ° C., in this mixed solution with stirring,
It was prepared by gradually adding straight asphalt heated and melted at 130 ° C., then adding water to obtain a predetermined solid content, and cooling. In addition, asphalt emulsion L was prepared by adding straight asphalt heated and melted at 130 ° C. to a surfactant aqueous solution and stirring the mixture.
It was prepared by post-adding a polymer latex. Properties of the asphalt emulsions A to L are shown in Tables 1 and 2.

[0012]

[Table 1]

[0013]

[Table 2]

<Preparation and Evaluation of Modified Asphalt Composition> Asphalt Emulsion A shown in Tables 1 and 2.
To L, the polyisocyanate compounds shown in Table 3 (Examples 1 to 6) and Table 4 (Comparative Examples 1 to 10) were blended, and the resulting modified asphalt composition had various physical properties described below (1 ) To (4) were evaluated. (1) Viscosity of Composition The viscosity was measured at 20 ° C. using a B type viscometer. (2) Viscosity stability of composition The viscosity stability of the modified asphalt composition was evaluated according to the following criteria according to the degree of viscosity change. The higher the viscosity stability,
Good coating suitability of the composition, which is advantageous in construction work. ◯: Viscosity change after 1 day relative to viscosity immediately after composition preparation is less than ± 10%, Δ: Viscosity change after 1 day relative to viscosity immediately after composition preparation is ± 10% or more and less than ± 30%, ×: Immediately after composition preparation Viscosity change after 1 day with respect to the viscosity of 30% or more. (3) Dry Curability of Composition The modified asphalt composition was applied onto a slate so that the dry coating thickness would be 7 mm, and the coating hardness after 5 hours
It was measured using a spring type JIS hardness tester. The larger this value is, the faster the dry-curability is and the better the workability is. (4) Waterproof and water-stopping properties of dry coating film Blistering resistance After applying the modified asphalt composition to a thickness of 1 mm on the slate, put it in a hot air dryer at 70 ° C. It was evaluated by. The better the blistering resistance, the more uniform the dry coating film can be formed. ◯: The number of blisters is 5 or less, Δ: The number of blisters is 6 to 10, and ×: The number of blisters is 11 or more. Slate Adhesion The modified asphalt composition was applied onto the slate to a thickness of 1 mm, dried at room temperature for 5 days, and then subjected to a cellophane tape peeling test according to JIS A-6910 for 100 squares of 2 mm square. , Depending on the number of remaining gobang,
The slate adhesion was evaluated. The larger this value, the better the adhesion to the base. Water absorption resistance The modified asphalt composition was coated on a release paper so as to have a thickness of 2 mm, dried at room temperature for 5 days, and then the dry coating film was immersed in room temperature water for 24 hours. ) Evaluated the water absorption resistance. Table 3 shows the evaluation results of Examples 1 to 6, and Table 4 shows the evaluation results of Comparative Examples 1 to 10.

[0015]

[Table 3]

[0016]

[Table 4]

As a result, the modified asphalt composition of the present invention has a viscosity stability, a dry hardening property, and a waterproof / dry film coating.
It excels in both aspects of waterproof performance. On the contrary,
When the amount of the polyisocyanate compound used is outside the range of the present invention (Comparative Examples 1 and 2), the waterproof / waterproof performance of the coating film is lowered, and when the amount of the polyisocyanate compound used is too large (Comparative Example 2), Even if the dry curability is improved to some extent, the viscosity stability of the composition is significantly impaired. Further, the amount of the surfactant used is outside the range of the present invention (Comparative Example 3 to
In 4), the viscosity stability of the composition was lowered, and when the amount of the surfactant used was too small (Comparative Example 3), the swelling resistance and slate adhesion of the dried coating film became insufficient, and the surfactant If the amount of the agent used is too large (Comparative Example 4), the dry curability of the composition and the water absorption resistance of the dry coating film are significantly reduced, and the asphalt emulsion and the composition have high viscosity and poor coating suitability. Further, when the Tg of the polymer latex is outside the range of the present invention (Comparative Examples 5 to 6), waterproofing
If the water-stop performance is lowered and the Tg of the polymer latex is too low (Comparative Example 6), the dry curability of the composition is also lowered.
Furthermore, if the total solids content of the asphalt emulsion is too low (Comparative Example 7), the dry curability of the composition and the slate adhesion of the dry coating film are significantly reduced, and the dry coating film has insufficient swelling resistance. . Further, the use ratio of the polymer latex and the asphalt is out of the range of the present invention (Comparative Example 8 to
In 9), the viscosity stability of the composition and the swelling resistance and slate adhesion of the dried coating are remarkably lowered, and when the amount of asphalt used is too small (Comparative Example 8), the viscosity stability of the composition is also increased. On the contrary, it decreases. Further, unlike the present invention, when the polymer latex is added after the asphalt latex has been prepared in advance (Comparative Example 10), the waterproof / waterproof performance of the dry coating film is significantly lowered.

[0018]

EFFECTS OF THE INVENTION According to the present invention, a polyisocyanate compound is added to an asphalt emulsion obtained by adding heat-melted asphalt to a polymer latex containing a surfactant and mixing them. It has excellent viscosity stability and dry-curability, good coating suitability, and can be laminated and applied in a short time. As a result, construction workability is extremely excellent, and waterproof and waterproof performance are also extremely excellent. A modified asphalt composition is prepared. Therefore, the modified asphalt composition of the present invention,
Wide range of applications, including waterproofing and waterproofing materials, such as on rooftops of concrete buildings, slopes and bottoms of industrial waste disposal sites, and walls of underground structures such as subways and tunnels, which require particularly high waterproofing and waterproofing performance. Can be used very suitably.

Claims (1)

[Claims] 1. A polymer latex having a glass transition point of −80 to + 10 ° C. and 2 to 70% by weight of a surfactant and 0.01 to 5 of a surfactant.
25 to 97.9% by weight of heat-melted asphalt is added to a latex compounded with 10% by weight, and the total solid content obtained by mixing is 100 to 100 parts by weight (solid content) of the asphalt emulsion having a total solid content of 60 to 90% by weight. And a polyisocyanate compound having a reactive isocyanate group 0.05
A modified asphalt composition containing about 40 parts by weight.