KR20130113129A

KR20130113129A - Composition for preparing mineral wool fiber having high solubility in body fluid and mineral wool fiber prepared therefrom

Info

Publication number: KR20130113129A
Application number: KR1020120035467A
Authority: KR
Inventors: 우봉기; 이병원; 이남수; 허균용; 정원식; 주석재; 강성호
Original assignee: 주식회사 케이씨씨
Priority date: 2012-04-05
Filing date: 2012-04-05
Publication date: 2013-10-15
Also published as: KR101348274B1

Abstract

The present invention relates to a composition for producing mineral wool fibers excellent in solubility in body fluids and mineral wool fibers prepared therefrom, and more specifically, SiO ₂ 29-42 wt%, Al ₂ O ₃ 17-23 wt%, FeO 3.6 ˜7.2 wt%, Fe ₂ O ₃ 0.1-4.8 wt%, CaO 18-28 wt%, MgO 7-13 wt%, Na ₂ O + K ₂ O 1-5 wt% The present invention relates to a composition for preparing a mineral wool fiber and a mineral wool fiber produced therefrom, which can be particularly suitably used as an inorganic fiber thermal insulator as well as having excellent solubility in water) and exhibiting high heat resistance and water resistance, low thermal conductivity, and the like.

Description

Composition for preparing mineral wool fiber having high solubility in body fluid and mineral wool fiber prepared therefrom}

Mineral wool (also called 'rock wool') is largely divided into two types depending on the purpose: general mineral wool, commonly referred to as stone wool or rock wool, and ceiling wool mineral wool, called bale wool. General mineral wool is produced by processing in various forms such as mat, board, pipe cover, etc. by using an organic binder such as phenolic resin. Used as the main material.

Typical characteristics that mineral wool should have include high heat resistance, water resistance, and low thermal conductivity. In the case of heat resistance, it indicates how much mineral wool retains its role as a heat insulator under high temperature conditions such as fire. In the case of water resistance, since the mineral wool fiber has an open-cell shape, external moisture such as rain or snow may penetrate into the mineral wool, or condensation may occur inside the mineral wool due to temperature difference, thereby reducing the thermal conductivity. Therefore, it shows the characteristic of how effectively this moisture is blocked. And, in the case of thermal conductivity, the most basic property of a heat insulating material indicates how well the heat is blocked when in contact with the heat insulating material. All three are common requirements for inorganic fiber insulation.

Mineral wool is melted by applying high-temperature heat to silicate ore and dropping it on the surface of the spinner in the form of a centrifugal rotation to tension the fiber using its centrifugal force, and at the same time spraying high-pressure air from the rear to wash the fiber. It is usually prepared in a fibrous manner.

In the case of the mineral wool produced in the above manner, the heat resistance is very excellent compared to other organic insulating materials, and has an advantage of showing excellent safety in an emergency situation such as a fire. However, there is an opinion that the fibrous dust scatters and enters the body through the respiratory tract, which may affect the human body. Therefore, many studies have been conducted on how to efficiently discharge the mineral wool fibers into the body. That is, by designing a specific composition, when the fiber is in contact with human body fluids within the lungs, it can be easily decomposed and dissolved in the body fluids, thereby minimizing the possibility of harmful mineral fibers.

This biodegradability is related to how efficiently the inorganic fiber invades the human body through the respiratory tract, so that it can be decomposed and released into the body. The mechanism proceeds differently depending on the pH. Inorganic fibers entering the lungs through the respiratory tract are basically exposed to neutral (pH 7.4) bodily fluids. When contacted with these neutral bodily fluids, the reaction rate is slow, but the dissolution of network formers including SiO ₂ The reaction continues and the adsorption of water on the surface of the inorganic fiber becomes easier due to the formation of OH-group on the surface of the fiber. On the other hand, the body fluid inside the macrophage, which plays a role in the treatment of external foreign matter inside the alveoli, is weakly acidic (pH 4.5), in which case ion exchange occurs predominantly to make the alkaline earth ions rich in aqueous solution. As the pH is continuously maintained at a high flow rate, fiber weight reduction in this process tends to be controlled by diffusion of ions. To assess biodegradation, in vitro testing that simulates this process is preferably used. Here, the flow-through method is used to reproduce the situation in which the fluid is continuously supplied.

However, if the biodegradability of the body fluids, the water resistance may also be lowered, and may be vulnerable to the moisture encountered in the general environment, so it is essential to find a composition having both adequate water resistance and biodegradability for the body fluids. In addition, high heat resistance and heat insulation, which are basic properties of mineral wool fibers, are essential elements.

Much research has been conducted on inorganic biodegradable fibers. Korea Patent Application Publication No. 2011-00097010 discloses a composition in which there is a relative increase in the SiO ₂ content to lower the content of Al ₂ O ₃ improves the biodegradability of the inorganic fibers is disclosed, in which the Al ₂ O _3, which in particular acts as an intermediate oxide The biodegradability was increased by reducing the content to increase the proportion of modified oxides relatively. However, this method has a problem in that it is difficult to apply in the case of mineral wool that must contain a certain amount or more of Al ₂ O ₃ in the raw material composition.

The present invention is to solve the problems of the above-described prior art, it is not only excellent in solubility in body fluids, but also exhibits high heat resistance and water resistance, low thermal conductivity, etc., and can be particularly suitably used as an inorganic fiber insulation material, the material composition of a certain amount or more It is a technical problem to provide a composition for preparing mineral wool fibers and mineral wool fibers prepared therefrom even when it is necessary to contain Al ₂ O ₃ essentially.

The present invention to achieve the above technical problem, SiO ₂ 29 ~ 42 wt%, Al ₂ O ₃ 17 ~ 23 wt%, FeO 3.6 ~ 7.2 wt%, Fe ₂ O ₃ 0.1 ~ 4.8 wt%, CaO 18 ~ 28 wt It provides a composition for producing mineral wool fibers, comprising%, MgO 7 ~ 13 wt% and Na ₂ O + K ₂ O 1 ~ 5 wt%.

According to a preferred embodiment of the present invention, the Redox value [FeO wt% / (FeO wt% + Fe ₂ O ₃ wt%)] of iron in the composition for producing mineral wool fibers is 0.6 or more.

According to another aspect of the present invention, there is provided a biodegradable mineral wool fiber for body fluid, characterized in that it is prepared from the composition for producing mineral wool fibers of the present invention.

According to another aspect of the invention, there is provided an insulation product comprising the mineral wool fibers of the present invention.

In accordance with the present invention, as to the solubility in body fluids excellent as indicated a high heat resistance and water resistance, low thermal conductivity, etc. may be particularly be suitably used as an inorganic fiber heat insulating material, a raw material configuration phase for a predetermined amount or more of Al ₂ O ₃ should be essentially free of Even suitable mineral wool fibers can be produced using conventional fiberizers.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In the present invention, SiO ₂ serves to form a basic skeleton of the glass as a network former oxide. In the composition for preparing mineral wool fibers of the present invention, SiO ₂ is included 29 to 42 wt% (wt%), more preferably 30 to 38 wt%. If the content of SiO _{2 in the} composition is less than 29 wt%, the physical properties of the mineral wool fibers prepared from the composition are lowered. If the SiO ₂ content is more than 42 wt%, the viscosity of the composition is increased, resulting in a coarse fiber and a large fiber diameter.

In the present invention, Al ₂ O ₃ is an intermediate oxide, the content of which affects the biodegradability of the composition. Depending on the coordination number of Al ³ ⁺ may partially replace the role of SiO ₂ , and may also act as a modifier oxide, which may vary depending on the content of other modified oxides. The composition for producing mineral wool fibers of the present invention contains Al ₂ O ₃ 17-23 wt%, more preferably 17-21 wt%. Al ₂ O _{3 in the} composition If the content is less than 17wt% or more than 23wt%, biodegradability may be lowered.

According to one embodiment of the invention, the main raw material as Al ₂ O ₃ content is by using the about 30% for about anorthosite (Anorthite) is more than 35% of the injected raw material mixed-composition in Al ₂ O ₃ content of the above Can be implemented at the level.

In the present invention, iron (FeO and Fe ₂ O ₃ ) is used to improve the heat resistance of mineral wool fibers. The composition for producing mineral wool fibers of the present invention contains FeO of 3.6 to 7.2 wt%, Fe ₂ O ₃ 0.1 to 4.8 wt%, more preferably 4.5 to 7.2 wt% FeO, 0.1 to 4.2 Fe ₂ O ₃ wt% is included. If the content of FeO and Fe ₂ O _{3 in the} composition is less than the above-mentioned level, there is a problem that the fiber shrinkage is increased or the thermal stability is lowered at high temperatures, and if it exceeds this, it causes an overload of the fiber manufacturing equipment to reduce durability. Occurs.

The Redox value [FeO wt% / (FeO wt% + Fe ₂ O ₃ wt%)] of iron in the composition represents the ratio of FeO content to the total iron content. Therefore, the higher the Redox value the amount of FeO is relatively higher, this fiber is the ratio of Fe ² ⁺ of the entire iron content means that the Fe ³ ⁺ higher contrast. When the fiber fibers in the air are exposed to high temperatures, FeO is oxidized to Fe ₂ O ₃ (that is, Fe ²⁺ is oxidized to Fe ³⁺ ), resulting in crystallization behavior of the fiber surface and the inside. The nanoscale thin periclase (MgO crystal) crystal phase is generated, thereby increasing the physical and chemical durability to improve the heat resistance of the fiber. This is especially true in mineral wool compositions with high iron content (PM Sørensen et al., Effect of the redox state and concentration of iron on the crystallization behavior of iron-rich aluminosilicate glasses, Journal of Non-Crystalline Solids 351 , (2005), pp. 1246-1253).

Therefore, a moderately high level of Redox value of iron in the composition is particularly preferable in terms of further improving the heat resistance of the fiber. In particular, this thermal stability is essential for mineral wool products that can be exposed to high temperatures instantaneously, such as in a fire situation. In one preferred embodiment of the invention, the Redox value of iron in the composition is at least 0.6 (eg, at least 0.6 and less than 1).

High levels of iron Redox can be obtained by melting the raw materials using an electric furnace using a graphite electrode. In this case, the continuous oxidation of graphite leads to the formation of a reducing atmosphere in the furnace, which can raise the redox of iron.

In addition, the existing mineral wool is mainly melted in Cupola (Cupola), which uses a fossil fuel cokes (Cokes) as a fuel has a disadvantage of generating a lot of greenhouse gases such as CO ₂ when melting. On the other hand, when melting using an electric resistance type electric furnace can greatly reduce such greenhouse gas emissions, it is easy to control the temperature in the furnace, has a variety of advantages such as to improve the homogeneity of the melt to stabilize the fiber quality.

In the present invention, CaO and MgO, which are alkaline earth metal oxides, may act as a flux as modifier oxides and increase chemical durability. The composition for producing mineral wool fibers of the present invention contains 18 to 28 wt% of CaO, 7 to 13 wt% of MgO, more preferably 20 to 25 wt% of CaO and 8 to 13 wt% of MgO. If the content of CaO and MgO in the composition is less than the above-mentioned level, there is a problem in that the melting temperature is increased to increase the heat consumption required for melting. This leads to deterioration of fiber quality, such as an increase in shot content.

In the present invention, the alkali metal oxides Na ₂ O and K ₂ O as another modified oxide to generate the non-crosslinked oxygen of the glass to facilitate the melting during melting, and serves to improve the biodegradability of the fiber. . Of mineral wool fibers for preparing the compositions of the present invention includes the 1 ~ 5 wt% to the total amount of Na ₂ O + K ₂ O, and more preferably contains 1.5 to 4.0 wt% the Na ₂ O + K ₂ O. The content of each of Na ₂ O and K ₂ O may be freely selected within a range satisfying the above range of total amounts. That is, the content of each of Na ₂ O and K ₂ O is in the range of 0 to 5 wt%, with the total amount being 1 to 5 wt%.

When the total amount of Na ₂ O + K ₂ O in the composition is less than 1 wt%, melting becomes difficult and not only consumes a lot of melt energy, but also increases the melt viscosity, thereby decreasing fiber flexibility and increasing the possibility of generation of unfibrillated particles. If exceeded, the water resistance deteriorates, and the high temperature stability may also be lowered.

Meanwhile, the composition for preparing mineral wool fibers according to the present invention may include components such as TiO ₂ , SO ₃ , and P ₂ O ₅ as impurities depending on the raw materials used, but the amount thereof may be 1 wt% or less in the total composition. If so, it does not affect the thermal properties or physical properties of the fiber.

There is no particular limitation on the method for producing the composition for producing mineral wool fibers according to the present invention, and by using the above components in the content range can be prepared by a method for producing a composition for a conventional mineral wool fiber. For example, it may be prepared by the same method as the electric melting method, but is not limited thereto. Preferably, the raw material may be melted by using an electric furnace of an electric resistance method using a graphite electrode.

There is no particular limitation on the method of fiberizing the composition for producing the mineral wool fiber of the present invention, and a conventional fiberizing method such as a blowing method or a spinning method may be applied. In applying this fiberization method, the viscosity range required for the fiber production composition is preferably 20 to 100 poise. The viscosity of the melt is a function of temperature and the corresponding composition, and the viscosity of the melt having the same composition will depend on the temperature. When the temperature of the melt is high during the fiberization, the viscosity is lowered. On the contrary, when the fiberization temperature is low, the viscosity is increased to affect the fiberization. If the viscosity of the fiber composition is too low at the fiberization temperature, the length of the fiber produced is short and thin as well as a lot of fine unfiberized particles (shots) to produce a low fiberization yield, even if the viscosity is too high diameter of the fiber The problem arises that this large fiber is formed and the coarse unfiberized shots are increased.

Accordingly, according to another aspect of the present invention, there is provided a biodegradable mineral wool fiber for body fluid, characterized in that it is prepared from the composition for producing mineral wool fibers of the present invention as described above.

The mineral wool fiber of the present invention preferably has a dissolution rate constant of 1) at least 300 ng / cm 2 · hr, more preferably at least 350 ng / cm 2 · hr, for artificial body fluids having a pH of 4.5; 1,000 ° C / 1 hour retention) is 5% or less, more preferably 4% or less, 3) the water loss test (100 ° C / 5 hour retention) is 1% or less, more preferably 0.7% or less, and 4 ) Satisfies one or more of the conditions that the thermal conductivity is 0.037 W / mK or less, more preferably 0.036 W / mK or less, more preferably two or more, even more preferably three or more, most preferably these Satisfies all conditions

According to another aspect of the present invention, there is provided an insulation product comprising the mineral wool fibers of the present invention as described above. There is no particular limitation on the specific form of the insulation product, and for example, plate, board, blanket, pipe cover, or any other form is possible.

According to a preferred embodiment of the present invention, the heat insulating material product of the present invention can be strengthened between the fibers by spraying the organic binder between the fibers and then cured.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the scope of the present invention is not limited by these.

[ Example ]

Example 1 to 6 and Comparative Example 1 to 7

By using an electric current melting method using a three-phase graphite electrode bar to prepare a composition for producing mineral wool fibers having the components and contents shown in Table 1 (Example) and Table 2 (Comparative Example), then spinning process for manufacturing a conventional mineral wool Mineral wool fibers were prepared by dropping the melt on the surface of a spinner in the form of a centrifugal rotation to tension the fibers, and at the same time, jetting high-pressure air from the rear to refine the fibers. The content analysis of each component was measured by high frequency inductively coupled plasma (ICP) method.

[Table 1]

[Table 2]

For the mineral wool fibers prepared in Examples and Comparative Examples, the dissolution rate constant (K _dis ) value, the Redox value, the heating contraction rate, the loss rate and the thermal conductivity in the water resistance test for the artificial body fluid were measured as follows. It was calculated and shown in Table 3 (Example) and Table 4 (Comparative Example).

Artificial body fluid dissolution rate constant Kdis )

In order to evaluate the biosolubility of the prepared fiber, the solubility in artificial body fluid was obtained by the following method. The biodegradability of the ceramic fiber in the body was evaluated based on the solubility of the fiber in the artificial body fluid, and after comparing the residence time based on the solubility, the dissolution rate constant (K _dis ) was calculated using the following equation.

Where d ₀ is the initial average fiber diameter (μm), ρ is the initial density of the fiber (g / cm ³ ), M ₀ is the mass of the initial fiber (mg), M is the mass of the remaining dissolved fiber (mg), And t represents the experiment time (hr).

The fiber to be measured was placed between thin layers between 0.2 μm polycarbonate membrane filters fixed with a plastic filter support, and the dissolution rate was measured by filtering artificial fluid between the filters. During the experiment, the temperature of the artificial fluid was continuously adjusted to 37 ° C. and the flow rate was 135 mL / day, and the pH was maintained at 4.5 ± 0.1 using hydrochloric acid (HCl, 35.0 to 37.0%).

In order to accurately measure the solubility of fibers occurring over a long period of time, the artificial fluids filtered at specific intervals (1, 4, 7, 11, 14, and 21 days) were subjected to inductively coupled plasma analysis (ICP, After dissolving the ions using an Inductively Coupled Plasma Spectrometer, the dissolution rate constant (K _dis ) was obtained using the above equation.

The content (g) of the composition contained in 1 L of the artificial body fluid used to measure the dissolution rate of the fiber was as follows.

Redox value

About 300 ml of water was added to a 500 ml beaker and boiled, and CO ₂ was extracted and cooled. 10 ml of sulfuric acid (1: 1) and 10 ml of saturated boric acid solution were added thereto and used as a test solution. Coagulate the mineral wool melt and finely crush 0.2 ~ 0.5g of the powder sample which is finely pulverized to the particle size of about 50㎛ or less in a sealed plastic beaker and wet it with the above test solution (10ml), and the same amount of sulfuric acid (1: 1) and hydrofluoric acid 10 ml) was added and then stirred. After the powder sample was completely decomposed, a solution in which saturated boric acid water was excessively added was used as a sample for analysis. 10 ml of Reinhard Zimmermann solution was added to this analytical sample, and titrated with 1 / 50-N KMnO ₄ solution. The end point was a point where pink did not disappear for 30 seconds. Blank tests were also performed in parallel, and Redox values were calculated from the following equation. At this time, the total iron content, which is the sum of FeO and Fe ₂ O ₃ , was applied to a value obtained through ICP analysis.

heating Contraction rate

The pad was manufactured with the prepared mineral wool and measured by the Hot Furnace Method. After preparing a pad of a predetermined size, it was cut to a size of 50 * 50mm, and the width and length of the cut pad were measured using a vernier caliper. The elevator furnace was then set to 1,000 ° C, and when the elevator furnace reached the set temperature, the pads were placed in the elevator furnace and held for 1 hour. After 1 hour, the pads were removed and the width and length were measured. The bow rate was calculated from the following equation.

Weight loss rate (Water resistance test)

DGG (Deutchen Glastechnischen Gesellschaftev) weight loss method was used. About 10 g of mineral wool was heated in 100 ml of distilled water and maintained at 100 ° C. for 5 hours, followed by rapid cooling and filtering. After drying at 150 ℃ with a filter after the weight is measured by weight compared to the initial weight was expressed as a percentage.

Thermal conductivity

The prepared mineral wool fibers were molded into a plate to prepare a sample (300 × 300 × 20 mm). About this sample, the thermal conductivity which finally converges by the heat flow meter method was measured by making the temperature difference of an average temperature of 20 degreeC, an upper plate, and a lower plate into 28 degreeC.

[Table 3]

[Table 4]

As can be seen from the above experimental results, the mineral wool prepared according to the present invention exhibits excellent biodegradability with a K _dis value of 300 ng / cm ² h or more, and at the same time, excellent heat resistance (that is, low shrinkage) and excellent water resistance (that is, , Low loss rate) and satisfactory level of thermal conductivity.

On the other hand, Comparative Examples 1 and 2 showed poor heat resistance (ie, high heat shrinkage), and Comparative Example 3 showed a high thermal conductivity due to an increase in the shot content with a large diameter inside the fiber due to the increased viscosity, and Comparative Example 4 There was a problem in heat resistance and water resistance, and the viscosity was so low that when the molten metal hit the spinner, it could not be fibrized and splashed, so the content of fine shot increased and the thermal conductivity was increased. Example 6 showed low biodegradability. Comparative Example 7 exhibited problems such as decrease in thermal conductivity, heat resistance, and water resistance reduction due to a decrease in viscosity.

Claims

SiO ₂ 29-42 wt%, Al ₂ O ₃ 17-23 wt%, FeO 3.6-7.2 wt%, Fe ₂ O ₃ 0.1-4.8 wt%, CaO 18-28 wt%, MgO 7-13 wt% and Na ₂ O + K ₂ O 1 to 5 wt%, the composition for preparing mineral wool fibers.

The composition of claim 1, wherein the Redox value of iron in the composition is 0.6 or more.

The composition of claim 1, wherein the raw material is manufactured by melting the raw material using an electric resistance type electric furnace using a graphite electrode.

A biodegradable mineral wool fiber for body fluids, which is prepared from the composition for producing mineral wool fibers according to any one of claims 1 to 3.

The mineral wool fiber of claim 4, wherein the mineral wool fiber satisfies at least one of the following properties:
1) Dissolution rate constant for artificial fluid at pH 4.5: 300 ng / ㎠ · hr or more
2) Heating preshrinkage rate (1,000 ℃ / 1 hour maintenance): 5% or less
3) Loss rate during water resistance test (~~ ℃ / 5 hours): 1% or less
4) Thermal conductivity: 0.037 W / mK or less.

[6] The mineral wool fiber according to claim 5, wherein all of the physical properties of 1) to 4) are satisfied.

Insulation product comprising the mineral wool fibers according to claim 4.

8. The thermal insulation product according to claim 7, wherein the organic binder is sprayed and cured between the fibers to harden the bond between the fibers.

8. Insulation product according to claim 7, characterized in that it is in the form of a plate, board, blanket or pipe cover.