JPS58201822A - Preparation of modified asphalt emulsion - Google Patents

Abstract

PURPOSE:To prepare the titled emulsion having excellent stability and high concentration, easily, by mixing a polymer latex or emulsion with molten asphalt in the presence of an emulsifier and a dispersion stabilizer each acounting for a specific ratio. CONSTITUTION:The objective emulsion having a water-content of 8-35wt% is prepared by mixing (A) a polymer latex or emulsion with (B) an emulsifier (preferably anionic emulsifier such as fatty acid salt, etc.) and (C) a dispersion stabilizer (e.g. bentonite, etc.), and adding (D) 100-1,200pts.wt. of molten asphalt (based on 100pts. of the solid content of the component (A)) slowly under stirring to effect emulsification. The sum of the components (A)-(C) is 0.5- 10pts.wt. per 100pts.wt. of the sum of the solid content of the component (A) and the component (D), and the weight ratio of the component (B) to the component (C) is 0.4/0.6-0.95/0.05.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method for producing a mixed emulsion of and asphalt. ``Asphalt is an inexpensive high-molecular-weight hydrocarbon compound that is widely used as a civil engineering construction or industrial material, such as paving materials, waterproofing materials, coating materials, adhesives, and caulking materials.

Asphalt is heated, melted, installed, and processed.
Most of them are used in a so-called hot melt manner, and aggregates, fillers, or polymers are often mixed and modified during heating and melting. However, in this case, heating at the site of use,
Melting equipment also requires larger equipment when adding compounds, poses fire hazards and worker safety issues, and requires use in a molten state.
There is the inconvenience of limited working conditions.

In addition, the modification of asphalt with a polymer is also significantly limited in its type and amount due to the limited compatibility of asphalt and the increase in melt viscosity of the modified asphalt.

In order to make asphalt easier to use, there is a method of dissolving it in a solvent, but its use is severely restricted due to the abrasive nature of the solvent. Furthermore, polymer-modified asphalt is difficult to dissolve in solvents, and is also subject to limitations in this respect. For this reason,
As a method for using it safely at room temperature, it has been in practical use for a long time to use it in the form of an aqueous emulsion on asphalt.

However, the conventional method for producing an asphalt emulsion involves emulsifying molten asphalt together with water and an emulsifier by applying strong shearing force such as in a colloid mill. The density of the asphalt emulsion produced by this method (referred to as asphalt emulsion) is limited to about 60% at most, and its storage stability is poor, and it does not have sufficient stability for various formulations. In addition, to make a modified asphalt emulsion using a polymer, there is a method in which the polymer is dissolved in asphalt in advance and then emulsified, and a polymer latex paste or emulsion is mixed into the finished asphalt emulsion. There is a way. The former is more effective than emulsification of asphalt alone.
゜It is much more difficult to emulsify, and as mentioned above, the type of polymer,
Quantity is limited. The latter method is less limited by the polymer latex or emulsion, but the concentration can be higher than that of the polymer and the emulsion, often due to the difference in diameter and emulsifier between the two. This causes phase separation and storage stability problems.

In order to make a high-concentration and stable asphalt emulsion modified with a polymer, the inventors of the present invention have already used various methods to add molten asphalt to high-concentration latex in Japanese Patent Publication No. 55-4146. We have discovered a method by which a highly concentrated and stable asphalt latex mixed emulsion with a water content of 17% or less can be prepared by stirring. but.

According to this method, the concentration of the polymer latex used is limited and the ratio of polymer to asphalt is also 100.
:Cannot exceed 300.

That is, this method relies on latex to emulsify asphalt.

The present inventors have conducted various studies in order to establish a wide range of production methods for high-concentration polymer-modified asphalt emulsions, and have found that emulsifiers and We have discovered a method for making a mixed emulsion of polymer and asphalt that allows the use of a wide range of polymer latexes or emulsions and allows for a wide range of ratios of polymer and asphalt by coexisting with a dispersion stabilizer.

In this case, it is necessary to use an emulsifier and a dispersion stabilizer together. If only the emulsifier is used in the amount required for emulsification, the amount of emulsifier will increase, resulting in smaller particle sizes and increased viscosity, which will likely cause problems with emulsion stability and reduce the water resistance of the film formed from the mixed emulsion. Ding. However, by using a dispersion stabilizer in combination, it is possible to reduce the amount of emulsifier, prevent excessive emulsification of asphalt with a small particle size, and improve emulsion stability.

That is, in the present invention, the solid content concentration is 40 to 720 to 72% by weight.
After adding the emulsifier and dispersion stabilizer together to the latex or emulsion, 1. 100 to 1200 parts by weight, preferably 350 to 1200 parts by weight
By gradually adding and emulsifying 5 parts by weight of molten asphalt under stirring, the water content is 8 to 35% by weight, preferably 10 to 600 to 60% by weight, and storage stability, work stability, and various other properties are improved. The present invention provides a method for producing a mixed emulsion of a polymer and asphalt, which can be reprocessed by stably adding a compounding agent.

As a polymer latex paste or emulsion, natural comb and histine, aromatic vinyl compounds such as vinyltoluene, vinyl cyanide compounds such as acrylonitrile and methacrylonitrile, acrylic acid, methacrylic acid, maleic acid, fumaric acid, Copolymers consisting of one or more monomers selected from unsaturated carboxylic acids such as itaconic acid or monoolefin derivatives such as their esters, and conjugated olefins such as isoprene, butadiene, chloroprene, acrylic acid, methacrylic acid, etc. There are polymer latexes such as polymers of one or more monomers selected from unsaturated carboxylic acids or their esters, ethylene, propylene, diene copolymers, ethylene, vinyl acetate copolymers 6-, etc. . The temperature at which these polymer latexes are used in the present invention is preferably 5 to 90°C.

If the temperature is below 5°C, the added molten asphalt will not be well dispersed.

If the temperature exceeds 90°C, the stability of the latex deteriorates, which is not preferable because both have a negative effect on the stability of the modified asphalt emulsion.

The polymer latex or emulsion that can be used has a solid content concentration of about 40 to 70% by weight and about 50 to 60% by weight; It is not limited to this unless it becomes.

Asphalt materials include natural asphalt, blown asphalt, and straight asphalt, and it is possible to use a blend of any of these. The temperature at which asphalt is added to the polymer latex or emulsion is preferably 70 to 150°C. If the temperature is below 70°C, dispersion of the asphalt will be poor, and if it exceeds 150°C, the stability of the polymer latex or emulsion will deteriorate.

Since polymer latexes or emulsions are generally anionic or nonionic emulsifiers, it is preferable to use anionic or nonionic emulsifiers as well. Examples of anionic salts include fatty acid salts, higher alcohol sulfate ester salts, alkylbenzene sulfonates, and rosin salts. In the case of nonionic materials, polyoxyethylene dalycol type materials can be used. As the stripped nonionic cation, polyethylene (including propylene) alkylamine can be used. However, depending on the latex, it may be necessary to adjust the pH using an alkali such as caustic soda or an acid such as diluted hydrochloric acid.

Examples of dispersion stabilizers include inorganic types such as Ben I, Nai I, and clay, and organic types such as polyvinyl alcohol, methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, sodium polyacrylate, starch,
Casein, etc. By using one or more of these dispersion stabilizers in combination with the emulsifier, the stability of the highly concentrated modified asphalt emulsion becomes more stable. The combined use of a dispersion stabilizer and an emulsifier is particularly effective when a large amount of asphalt is added to the polymer latex or emulsion in order to obtain a modified asphalt emulsion with good stability.

The total amount of emulsifier and dispersion stabilizer varies depending on the type of polymer latex or emulsion, polymerization conditions, amount of asphalt added, etc., but it is 0.5 to 10 parts by weight per 100 parts by weight (solid content) of polymer latex or emulsion and asphalt in total. parts, preferably 1 to 6 parts by weight. The total amount of emulsifier and dispersion stabilizer is preferably used in proportion to the amount of asphalt added. Note that the amounts of emulsifiers and dispersion stabilizers herein are calculated including those in the polymer latex or emulsion. Further, the weight ratio of the emulsifier to the dispersion stabilizer was 0.4/. 6 to O95/1005, preferably 05105 to 09101. If the total amount is less than 0.05 parts or the ratio exceeds 0.95 parts, the stability of the modified asphalt emulsion will be reduced. The total amount exceeds 10 parts by weight or the ratio is 04//CI
If it is less than 6, the viscosity of the modified asphalt emulsion increases and the workability deteriorates. Furthermore, since the dispersion stabilizer is generally added as a low-concentration aqueous solution, the higher the dispersion stabilizer addition ratio, the lower the emulsion concentration, making it difficult to obtain a highly concentrated modified asphalt emulsion. Can not.

The amount of asphalt added is 100 to 1200 parts by weight per 100 parts by weight of the solid content of the polymer latex or emulsion.
It is added in an amount of 350 to 1200 parts by weight, preferably 350 to 1200 parts by weight.

The amount of asphalt added is 1o.

If it is less than 1 part by weight, it will be difficult to produce a modified asphalt emulsion with a concentration of 65% by weight or more, and if it exceeds 1200 parts by weight, the stability of the modified asphalt emulsion will decrease.

The modified asphalt emulsion of the present invention has a high concentration and a water content of 8 to 35% by weight, preferably 11) to 3030 parts by weight. Moisture content "J1" is 65% by weight TO
- If it exceeds the limit, the drying properties will be poor, and the drying shrinkage of the shredded film will be large, resulting in poor workability. Also, when it becomes less than 8 weight section,
The viscosity of the modified asphalt emulsion increases, resulting in poor workability and difficulty in producing a uniform and highly concentrated modified asphalt emulsion.

The modified asphalt emulsion obtained by the present invention uses a combination of an emulsifier and a dispersion stabilizer to produce a modified asphalt emulsion with a large amount of added asphalt, which has been difficult to manufacture in the past, and a high concentration with good stability. Concentrated polymer latexes can now be easily produced without having to be prepared from a concentrate or emulsion.

High-concentration modified asphalt emulsion can be used alone or by adding various fillers, fiber substances, etc., for easy workability.
In addition, it can be used as a relatively inexpensive paint spraying material for waterproofing materials, water-blocking materials,
Pavement flooring materials, mortar protection materials, insulation materials, soundproofing materials, rust prevention materials,
It is extremely effective in applications such as preservatives, protection materials, joint fillers, adhesives, backing materials, and raw materials for forming sheets. Fillers to be added include clay, calcium carbonate,
The main ones include aluminum hydroxide, Merck, barium sulfate, silica sand, mica powder, and rubber powder. Examples of fibrous substances include asbestos, glass fiber, nolpflock, and cotton linters.

Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Carboxyl-modified styrene-butadiene copolymer latex (manufactured by Synthetic Rubber Co., Ltd., JSRO692, total solid content 4
Add 2 parts by weight of a 30% aqueous solution of potassium oleate and 1 part by weight of an aqueous solution of 10 tons of bentonite clay to 20 parts by weight (solid content: same as below), heat this to 45°C, and then add molten asphalt at 115°C. 80 parts by weight (straight asphalt with a penetration rate of 80 to 100) was gradually added with stirring to produce a modified asphalt emulsion. (Produced asphalt latex solid content 71%). After cooling, there was no residue when filtered through an 80-mesh wire mesh. Furthermore, this emulsion was allowed to stand for one week, but it did not separate.

Example 2 Carboxyl-modified styrene-butadiene copolymer latex (manufactured by Japan Synthetic Rubber Co., Ltd., JSR0668, total solid content 48
%) 15 parts by weight and 30% Emulsion 920 (polyoxyethylene nonylphenol ether, manufactured by Kao Soap Co., Ltd.)
3 parts by weight aqueous solution, 10% bentonite clay aqueous solution 1.
After adding 0 parts by weight of Hichiro-&'H10000 (methyl cellulose, manufactured by Hoechst) 3 multi-aqueous solution and heating to 45°C, molten asphalt at 115°C (penetration 80-100, strained asphalt) was added. A modified asphalt emulsion was obtained by gradually adding 85 parts by weight of Al)) with stirring (solid content: 71%). After cooling, it was filtered through an 80-mesh wire mesh, but no residue was found. Further, this emulsion was sprayed using an airless pump (compression ratio (1:35) (tip diameter: 1.3 tan), but the tip was not clogged.

Example 3 Emulgeta 92030 was added to 8 parts by weight of the carboxyl-modified styrene-13-butadiene copolymer used in Example 2.
3 parts by weight of % aqueous solution and 1 part of 10% bentonite clay solution
．． After adding 5 parts by weight and stirring at 45°C, 92 parts by weight of 115°C molten asphalt (penetration 80-100, strained asphalt) was gradually added with stirring to obtain an emulsion fr: (Produced asphalt latex solid content: 75).

After cooling, it was filtered through an 80-mesh wire mesh, and there was no residue.

Example 4 145 parts by weight of styrene-butadiene copolymer latex (manufactured by Japan Synthetic Rubber Co., Ltd., JSRO561, total solid content 69%), 1.4 parts by weight of a 30% potassium oleate aqueous solution, GOHSENOL GTJ-05 (polyvinyl alcohol, Japan) After adding 0.25 parts by weight of 10% aqueous lVj (manufactured by Synthetic Kagaku Co., Ltd.) and 13 parts by weight of water and heating to 45°C, 855 parts by weight of 115°C molten asphalt (penetration 80-100, straight asphalt) was stirred. The mixture was gradually added to obtain an asphalt emulsion (produced asphalt latex 14-solid content: 80%). - Days later, when it was applied to kraft paper, the asphalt particles were small and the dispersion was good.

Although this emulsion was allowed to stand still for 10 days, no separate layer was formed.

Example 5 Methyl methacrylate-butyl acrylate-2-ethylhexyl acrylate copolymer latex (total solids content 4
Add 4 parts by weight of 30% Emulgen 920 aqueous solution and 0.5 parts by weight of 10% bentonite clay aqueous solution to 20 parts by weight of 5%), heat to 45°C, and gradually add 80 parts by weight of molten asphalt at 115°C with stirring. A quality asphalt emulsion was obtained. - When I applied the asphalt latex produced on kraft paper, the asphalt particles were small.
Dispersion was good.

Example 6 Carboxy-modified IIIBR latex (40% total solids)
) To 10 parts by weight were added 18 parts by weight of a 60% aqueous solution of potassium oleate, 2 parts by weight of a 10% aqueous solution of Go-Septanol GL-05, and water so that the final solid content was 75%.
90 parts by weight of molten asphalt at 15° C. was gradually added with stirring to obtain asphalt latex.

When applied to raft paper one day later, the asphalt particles were small and the dispersion was good.

Comparative Example 1 To 12 parts by weight of styrene-butadiene copolymer latex (manufactured by Japan Synthetic Rubber Co., Ltd., JSR0561), 2 parts by weight of a 30% potassium oleate aqueous solution and 15 parts by weight of water were added.
Molten asphalt at 115℃ after heating to ℃ (penetration 80~
100, straight asphalt) was gradually added while stirring (solid content of the produced asphalt latex: 80%).

When applied to raft paper one day later, the asphalt particles were large and the stability was poor. Let the emulsion stand still 6
After a few days, an asphalt-rich layer formed on the upper layer and separated.

Comparative Example 2 To 20 parts by weight of carboxyl-modified styrene-butadiene copolymer latex (manufactured by Japan Synthetic Rubber Co., Ltd., JSR0692), 6 parts by weight of a 30% potassium oleate aqueous solution and 7 parts by weight of water were added, heated to 45°C, and then melted at 115°C. 80 parts by weight of asphalt (penetration 80-100, straight asphalt) was gradually added with stirring. After cooling, it was filtered through a 20-mesh wire mesh, and a large amount of residue was found.

I also tried spraying this with an airless pump, but the chip often got clogged and spraying was difficult.

Patent applicant: Japan Synthetic Rubber Co., Ltd. Japan Latex Processing Co., Ltd. Agent: Patent attorney Akira Ito 17-

Claims (1)

[Claims] When mixing and stirring 100 parts by weight (solid content) of polymer latex or emulsion and 100 to 1200 parts by weight of heat-molten asphalt in the presence of an emulsifier and a dispersion stabilizer, the total amount of the emulsifier and dispersion stabilizer is Combined latex or emulsion and asphalt total 1
05 to 10 parts by weight per 00 parts by weight (solid content), and the weight ratio of the emulsifier to the dispersion stabilizer is 0.4/0.6 to 0.9.
510.05, the water content is 8~
Method for producing a high concentration polymer-modified asphalt emulsion with excellent stability of 35% by weight