KR20110032028A - Low melting point modified sulfur binders and their manufacturing method - Google Patents

Abstract

PURPOSE: A low melting point modified sulfur binder is provided to exhibit re-meltable property at a temperature of 100 °C or less by mixing ammonium salts or urea-based compounds with a dicyclopentadiene-based modifier. CONSTITUTION: A low melting point modified sulfur binder is obtained by mixing 99~60 weight% of sulfur and 1~40 weight% of dicyclopentadiene-based mixture, ammonium salts or urea-based compounds as a modifier of the sulfur, and melting and reacting the mixture. The dicyclopentadiene-based mixture is dicyclopentadiene alone, or a mixture in which at least one of cyclopentadiene, dicyclopentadiene derivative, and cyclopentadiene derivative is added to dicyclopentadiene, or a mixture to which at least one of dipentene, vinyltoluene, styrene monomer, and dicyclopentene is added.

Description

Low Melting Point Modified Sulfur Binders and Their Manufacturing Method

The present invention is a low melting point that can be used in combination with a hydraulic binder such as cement and gypsum by melting the modified sulfur binder for the production of sulfur concrete having a faster hardness, acid resistance and chemical resistance than ordinary cement concrete at a low temperature below 100 ℃ The present invention relates to a modified sulfur binder and a preparation method thereof.

Normally, ordinary concrete made using Portland cement exhibits alkali and very vulnerable to acids, with much of the degradation due to chemical reactions. The most common of these is the corrosion situation caused by salting or neutralization of concrete structures. In particular, concrete structures exposed to salty environment are a major problem due to premature deterioration due to corrosion of reinforcing bars. In general, construction for repairing and reinforcing steel is burdened in terms of work time and material cost since the construction is usually carried out by stacking several layers of epoxy or glass mat for repairing.

In order to overcome the disadvantages such as weak chemical resistance and strength of ordinary concrete, modified sulfur concrete using modified sulfur as a binder instead of Portland cement and mixing it with various aggregates to produce mortar or concrete. Technology has been developed. In the case of using modified sulfur binders, water cannot be used due to the characteristics of the modified sulfur concrete, and a molten sulfur melt is used.

However, the modified sulfur concrete is limited in its application due to resistance to freeze-thawing in water, surface depression due to temperature difference between the inside and outside of the test specimen due to rapid cooling after pouring, aggregate or form preheating problem, and fire vulnerability. .

That is, as the current technology, the modified sulfur concrete should be used only in the ground, the sea, and the water. Therefore, the scope of application of the modified sulfur concrete is limited. Therefore, the expanded sulfur concrete is widely used as a general construction material. This is not happening.

Looking more specifically, the development of technology to apply sulfur to the civil engineering and construction fields using the properties of sulfur, that is, "dissolved above 119 ℃ and solid at room temperature" has been continuously tried. For example, it is used as a binder of a packaging material (US Patent No. 4290816), a building material (JP-A 55-49024), or a waste solidification material (JP-A 62-15274). This is under review.

However, with regard to the combustibility of sulfur, sulfur has a flash point of 207 ° C, a spontaneous ignition temperature of 245 ° C, and flammability, and sulfur exposed to the surface has a problem of burning easily. In addition, in terms of mechanical strength, sulfur exhibits high strength when there is no defect in a stable solid state, but in reality, when cooled and solidified from a liquid state, three types of tetragonal, monoclinic, and amorphous sulfur are mixed and There is a brittleness problem in which brittleness tends to occur and brittleness with time as the mixing ratio changes. Therefore, the use range of pure sulfur as a binder is very limited.

Many sulfur modifiers have been investigated to remedy this drawback.

In particular, since dicyclo pentadiene (DCPD) is inexpensive, it is excellent in economic efficiency, and together with "New Uses of Sulfur-II, 1978, PP." 68-77, 1978 ", is known to have a good effect on mechanical strength and the like.

In addition, vinyl toluene, dipentene, and other olefin oligomers have been added to improve the properties of sulfur and used as packaging materials, adhesives, and waterproofing materials (Japanese Patent Publication No. 2-25929) Japanese Patent Application Laid-Open No. 2-28529) is also known.

In addition, Japanese Patent Application Laid-Open No. 2003-277108 uses tetra hydraulic indene as a sulfur modifier, and Japanese Patent Laid-Open No. 2002-60491 uses dicyclopentadiene and tetra hydraulic indene as a modifier. What was used together is disclosed, and the thing which mixed asphalt and sulfur as a road pavement material is utilized.

Typically, the reaction of dicyclopentadiene with sulfur can be viewed as a kind of polymerization reaction, and the reaction mechanism associated therewith is described in US Pat. No. 4,311,826. In the production of modified sulfur, the chemical reaction involves dicyclopentadiene and sulfur reacting at the beginning of the reaction, and then sulfur is polymerized by a radical chain reaction.

However, the subsequent reaction of dicyclopentadiene and sulfur is accompanied by a large exotherm, so there is a problem that the reaction control is difficult due to an increase in temperature and viscosity, and it is rapidly solidified at room temperature and cannot be molded.

To solve this problem, U.S. Patent No. 4,311,826 discloses a technique for reacting sulfur with 20 to 40% by weight of a modifier (combination of oligomer mixtures consisting of at least trimers of dicyclopentadiene and cyclopentadiene). have. In addition, Japanese Patent Application Laid-Open No. 2-28529 and its corresponding U.S. Patent No. 4,391,969 are polymers reacted with sulfur and 2 to 20% by weight of a modifier (modifier containing dicyclopentadiene oligomer mixture and dicyclopentadiene). Although a modified sulfur binder is disclosed, it is required to add at least 37% by weight of the cyclopentadiene oligomer in the modifier. On the other hand, Korean Patent Laid-Open No. 2006-101878 discloses that when dicyclopentadiene, which is substantially free of oligomers of at least 3 dimers of dicyclopentadiene, is used as a modifier alone, the amount of addition is controlled within 2 to 4% by weight. It has been disclosed that a modified sulfur binder can be prepared with excellent stability.

In addition, Korean Patent Registration No. 10-0911659 and Korean Patent Application No. 10-2009-004226 disclose sulfur by modifying sulfur by mixing heterocyclic amines or alkylamines with dicyclopentadiene-based modifiers as sulfur modifiers. It has been disclosed that a modified sulfur binder can be produced that exhibits physical properties that can be remelted at temperature.

However, according to the above patent, heterocyclic amines or alkylamines were used as low-melting sulfur modifiers. Especially, pyridine-based compounds have a bad smell and are difficult to work with during the manufacture and use of low-melting-point modified sulfur binders and are not good for the health of workers. In addition, the price of raw materials is expensive, and manufacturing costs are high.

The present invention uses ammonium salts or urea compounds, which are inexpensive and free of decomposition products, for the purpose of solving the above-mentioned problems. The present invention provides a low melting point modified sulfur binder and a method for producing the same, which exhibit physical properties that can be remelted at a temperature of 100 ° C. or less that can be mixed with a hydraulic material.

In order to solve this problem, a low-melting-point reforming sulfur binder comprising 99 to 60% by weight of sulfur and 1 to 40% by weight of a dicyclopentadiene-based mixture and ammonium salt or urea-based compound as a modifier of the sulfur. And at this time, the mixing temperature can achieve the object through the manufacturing method characterized in that the production in the temperature range of 120 ~ 160 ℃ to make the reaction in the molten state.

According to the present invention, ammonium salts or urea compounds, which are inexpensive and have no decomposition products and are not harmful to health, are mixed with dicyclopentadiene-based modifiers in order to reform sulfur. It is possible to provide a low melting point modified sulfur binder exhibiting physical properties that can be remelted at the following temperature.

 In addition, when the concrete is prepared by mixing general cement and aggregate with the low melting point modified sulfur binder, it may express fast hardening, strength enhancement, acid resistance, chemical resistance, and excellent freeze-thawing characteristics.

Hereinafter, a preferred embodiment of the present invention will be described in detail.

In the present invention, the term "hydraulic" used in hydraulic materials, hydraulic modified sulfur material compositions, hydraulic modified sulfur mortars or hydraulic modified sulfur concrete, etc., means "cemental materials or water" in KS L 0005 (standard term in hydraulic cement field). As expressed in the term "chemical substance", an inorganic substance or a mixture of inorganic substances refers to a substance in which a hydrate is formed by chemical reaction with water, thereby exhibiting condensation and expression of strength, and the reaction also occurs in water. More specifically, when the hydraulic material and water are mixed with the modified sulfur binder, the reaction occurs chemically, which is cured at room temperature to express the strength, and finally, the ability to be manufactured into a very dense and hardened body.

When re-melting the modified sulfur binder prepared by the method proposed in the existing patent, it is melted at about 115 ° C and needs to be heated at about 130 ° C to mix with the aggregate, so it is mixed with a hydraulic material based on a hydration reaction with water. Can not use it.

 Therefore, in order to mix and use the modified sulfur binder and the hydraulic material together with water, it is an important issue whether the reconditioning is possible under 100 ° C., which is the evaporation temperature of water.

In addition, a hydrophilic group (radical) should be combined to allow the surfactant to react well with the reformed sulfur so that it can be well dispersed in water and exhibit a homogeneous property.

In the present invention, the term "modified sulfur binder" means a liquid-modified sulfur binder in which an ammonium salt or a urea compound which is inexpensive and has no decomposition products and does not harm odors and health is melt-mixed with a dicyclopentadiene-based modifier. And a solid-state modified sulfur binder obtained by cooling the liquid modified sulfur binder at a temperature of 120 ° C. or lower, and at a temperature of 100 ° C. or lower which can be mixed with a hydraulic material. Means both low melting point modified sulfur binders.

 As shown in the comparative example, when sulfur is modified with dicyclopentadiene-based and pyridine-based modifiers, remelting is possible at 85 ° C. However, it is difficult to manufacture due to the nasty odor. This can be a problem and the absence of hydrophilic groups and the large viscosity forces no mixing with water.

The low melting point binder used in the present invention is an ammonium salt or a urea-based compound having an ammonia group (NH ₄ ⁺ ), which lowers the melting point by reacting with sulfur to weaken the bond, and in most manufacturing and use temperature ranges. It is safe because there is no decomposition, and even if some decomposition is done, it is inexpensive because it is harmless to health.

Ammonium salts are compounds produced by reaction of an ammonia group with an acid and include organic salts such as ammonium oleate and ammonium stearate as well as general salts such as ammonium acetate, ammonium formate, ammonium sulfate and ammonium phosphate.

In addition, the urea-based compound includes a compound such as urea nitrate, urea acetate and urea formate, and a high molecular compound such as urethane substituted with a portion thereof based on urea.

 When at least one or more of the ammonium salts or urea-based compounds are used in combination with a dicyclopentadiene-based modifier, the melting point is lowered depending on the amount added.

A two-necked flask was placed in a magnetic stirrer that could be heated, insulated, and stirred, and 60 to 100 g (60 to 80 wt%) of industrial powder sulfur was added to the flask to melt sulfur at about 120 to 130 ° C., followed by While stirring using a bar, 15-20 g (12-20 wt%) of a dicyclopentadiene solution containing 10-20 wt% of methylcyclopentadiene was slowly added to promote the reaction. At this time, while maintaining the temperature of the reaction between 120 ~ 160 ℃ while keeping in mind the sudden rise of the temperature due to the exothermic reaction was stirred for 30 to 40 minutes.

 At this point, when the reaction product becomes darker by the reaction, if the reaction is further performed for 10 to 20 minutes, the viscosity increases and the color becomes dark brown. At this time, 10-20 g of pyridine, ammonium formate and urea as low melting point modifiers (8-20 wt%) was added and the reaction continued for 30 minutes.

When the viscosity is increased by the reaction of sulfur and the modifier, the rotation speed of the magnet bar is remarkably decreased. At this time, the reaction is terminated and cooled to room temperature to prepare a solid low melting point modified sulfur binder.

The compositions and remelting temperatures for the low melting point modified sulfur binders obtained above are shown in Table 1.

In particular, the low melting point modified sulfur binders were added in order to see the change in melting point as shown in Table 1, and the reaction was evaluated by mixing with sweet rice or each other.

Compared with Comparative Example 1, the color of the reactant was changed to black when pyridine was added, but the color of ammonium formate and urea was slightly darkened, but did not change significantly.

In order to confirm the remelting temperature of the low melting point modified sulfur binder, it was confirmed by increasing the temperature to 85 ~ 110 ℃ using an oven capable of temperature control.

In addition, by using a hot plate that can be heated and stirred to determine whether remelting is possible at a temperature of 100 ° C. or less, which can be mixed with a hydraulic material as shown in FIG. Stirring was increased to 85 ~ 100 ℃.

division brimstone DCPD Pyridine Formic acid
ammonium Element Remelting
Temperature (℃) Remarks Comparative Example 1 83.3 16.7 - - - 110 Brown Comparative Example 2 77 11.5 11.5 - - 85 black Example 1 80 12 4 - 4 90 black Example 2 83.2 12.6 - - 4.2 100 Dark brown Example 3 80 12 - - 8 90 Dark brown Example 4 80 12 - 4 4 85 Dark brown Example 5 80 12 - 8 - 85 Dark brown Example 6 71.4 14.3 - 14.3 - 80 Dark brown Example 7 60 20 20 - 85 Dark brown

As shown in Table 1, it can be seen that the remelting temperature of the prepared low melting point modified sulfur binder is lowered according to the addition amount of the low melting point modifier, and when the total amount of the modifying agent is more than 40% by weight, curing is slow and curing is performed. It is also difficult to increase the strength after showing ductility. That is, the total amount of modifier in the mixture of sulfur and modifier is preferably in the range of 10 to 30% by weight.

1 is a composition range and remelting temperature range of sulfur (sulfur), dicyclo pentadiene modifier (DCPD, dicyclo pentadiene) and low melting point modifier (LMM, Low Melting Modifier) in the low melting point modified sulfur binder prepared according to the present invention It is shown.

2 is a liquid phase state in which the low melting point modified sulfur binder according to the present invention is present in boiling water (a) and (a ') is the side and top of Comparative Example 1, (b) and (b') is Example 3 Side and top of the (c) and (c ') are the side and the top of Example 6, in the case of Comparative Example 1 is not melted in water, Example 6 is a photograph showing that the molten.

Claims (11)

A low-melting-point modified sulfur binder, characterized by reacting 99 to 60% by weight of sulfur and 1 to 40% by weight of a dicyclopentadiene-based mixture with an ammonium salt or urea-based compound as a modifier of the sulfur. The method of claim 1, The dicyclopentadiene-based mixture is dicyclopentadiene (DCPD) alone or a mixture in which at least one of cyclopentadiene (CPD), DCPD derivative, and CPD derivative is added to DCPD or dipentene, vinyltoluene, styrene monomer Sulfur modifier, characterized in that the mixture is added at least one of dicyclopentene. The method of claim 1, The ammonium salt or urea compound modifier is a low melting point modifier, characterized in that the low-melting-point sulfur modifier is a mixture of ammonium salts, mixed ammonium salts thereof, or a mixture of at least one of the urea, urea compounds. The method of claim 1, The ammonium salt or urea-based compound modifier is a low melting point sulfur modifier, characterized in that a mixture of at least one of heterocyclic amines or alkylamines that is a similar low melting point modifier. The method of claim 1, The low melting point modified sulfur binder is a modified sulfur binder, characterized in that the liquid or solid phase. A method for producing a low melting point modified sulfur binder in which sulfur is reacted by mixing and melting the dicyclopentadiene mixture modifier with an ammonium salt or a urea compound with a low melting point modifier. The method of claim 5, And 99 to 60% by weight of sulfur and 1 to 40% by weight of the modifier mixture, wherein the mixing temperature is prepared at a temperature in the range of 120 to 160 ° C. such that the reaction is performed in a molten state. The method of claim 5, After heat-reacting the pentadiene-based modifier with sulfur to sulfur, a mixture in which at least one of ammonium salts or urea-based compounds, which are the low-melting-point sulfur modifiers, is added and heat-treated to prepare a liquid modified sulfur binder. Method for producing a low melting point modified sulfur binder. The method of claim 5, The dicyclopentadiene-based modifier is reacted with sulfur, followed by cooling to prepare a solid phase reactant. The solid phase reactant is further melted, and a mixture of at least one of ammonium salts or urea compounds, which are the low melting point sulfur modifiers, is added thereto. The method for producing a low melting point modified sulfur binder, characterized in that to produce a liquid low melting point modified sulfur binder by heat treatment. The method of claim 5, The low melting point reforming sulfur binder is a low melting point reforming sulfur binder, characterized in that the cooling step below the solidification temperature to produce a solid low-melting-point reforming sulfur binder. The method of claim 5, And mixing the low melting point modified sulfur binders having different solid melting points with each other to homogenize by reacting at a melting point temperature to produce a low melting point modified sulfur binder.

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