JPS62299596A - Inorganic sheet - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 3. Detailed description of the invention <Industrial application field> This invention is mainly applicable to wall and ceiling materials of buildings.

This invention relates to an inorganic sheet for imparting flame retardancy and fire resistance to flooring materials and the like.

<Background Art> In recent years, as buildings have become taller, larger, and more concentrated, importance has been placed on making buildings flame retardant and fire prevention measures.

Conventionally, wA oak fiber sheets, which impart flame retardancy to various building materials, have been used for this purpose. Examples of this type of inorganic sheet include asbeth 1 - fiber paper, flame retardant chemical treated paper,
Papers high in aluminum hydroxide powder are generally known.

<Problems to be solved by the invention> The above-mentioned conventional asbestos fiber paper is made by mixing asbestos fibers with cellulose fibers and exhibits excellent flame retardancy, but asbestos fibers are designated as a specified substance. and pollution prevention.

Its use is restricted due to work environment hygiene issues, and its use is prohibited in some countries.

Flame retardant chemical treated paper uses phosphorus as the treatment agent.

A halogen-based, titanium-based, ammonia-based, nitrogen-based, or composite system of these is added internally to cellulose fibers, or impregnated after the sheet is made, so that the paper contains about 10 to 30% of the drug. In the case of chemically treated paper using the internal addition method,
Combinations of tripartite antimony and chlorinated paraffin, and ammonium polyphosphate and polyethyleneimine have been proposed as drugs. However, when using the former agent, there is a problem because antimony contains toxic substances such as arsenic and lead as impurities. If it is added in an amount of about 9% by weight or more, the yellowing of Sea 1~ will become significant, and the flame retardance will be extremely reduced when immersed in hot water.

On the other hand, in the case of chemically treated paper produced by the impregnation method, the chemical tends to be eluted by light, heat from the processing process, or high humidity atmosphere, reducing the flame retardance.

Aluminum hydroxide powder Aluminum hydroxide commonly used in high-content paper has a gibbsite crystal structure, with 2O0~
Since crystal water is dehydrated at 300'C, it exhibits an excellent flame retardant effect, and there are no problems in handling or hygiene such as pollution, so it can be said to be a safe flame retardant paper at present. However, since the aluminum hydroxide after dehydration becomes alumina powder, the sheet shape cannot be maintained, and the carbonized portions are missing and penetrate through the sheet. Therefore, for example, when this paper with a high content of aluminum hydroxide powder is used as a face material sheet for a plastic foam insulation material, the face material sheet itself must meet the JIS standards.
Even if the product passed grade 1 flame retardant according to the A-1322 standard, there was a problem in that the carbonized portion of the face material sheet was missing and penetrated, resulting in the foam insulation material in the lower layer burning with smoke.

This invention was developed in view of the above-mentioned problems with conventional inorganic sheets, and it does not use asbestos fibers or flame retardants, which are harmful and problematic to handle, and also contains a high content of aluminum hydroxide powder. The aim is to obtain an inorganic sheet with a high flame retardant effect that can eliminate the defects such as missing and penetrating carbonized parts that are observed in paper.

<Means 2 for solving the problem> The flame-retardant inorganic sheet according to the present invention contains 2CaO4380.5H in 15 to 50% by weight of a fibrous material mainly composed of cellulose fibers.
Hydrous calcium borate powder represented by the chemical formula 2O 50
It is characterized in that it is made of a sheet-like material on which ~85% by weight is fixed and supported.

The hydrated calcium borate used in this invention may be artificially synthesized, but it is generally preferable to use an Fa acid acid product called perovorite. This perioborite has traditionally been used for industrial purposes such as heat-resistant and chemical-resistant glass products, long-fiber glass fibers, and raw material for nm fertilizers, but since it is not produced in Japan, it is mainly imported from countries such as the Republic of Turkey. ing.

The physical, chemical and thermal properties of such borate are as follows.

General composition B2O3: 40-50% CaO: 25-28% Machi0: 2O-22% pH 8-9 Thermal decomposition Endothermic dehydration decomposition at 350-450°C 850-
Melting and vitrifying solubility at 1050°C Refractory to water, alcohol, and other solvents The most important feature of using boronite in the inorganic sheet of this invention is its thermal decomposition ability, which melts and vitrifies at 850°C. It is in. i.e. melting.

By vitrifying the sheet, the carbonized portion of the sheet will not be broken or penetrated, and when used in conjunction with combustible materials, the surface of the combustible material will be covered with molten vitrified perovskite, which will isolate it from the air. Combined with the endothermic action caused by the dehydration of the crystallized water of perioborite, it is possible to provide unprecedented flame retardancy.

Zarani borite is not subject to alteration due to external environment such as heat or light, is chemically stable, and there are no regulations regarding its handling. In addition, since the l)H of perovskite is 8 to 9, there is no risk of corrosion of the machine during the papermaking process.

The fibrous material used in this invention is mainly composed of cellulose fibers such as paper pulp.
Fiberglass if required.

One or more types of inorganic fibers such as rock wool fibers, masonry water salt fibers, and alumina fibers can be used in combination with cellulose fibers. Although the cellulose fibers are not particularly limited, it is preferable to use fibrillated cellulose fibers or cationically modified pulp obtained by cationizing long-fiber natural cellulose pulp in order to enhance the effect of fixing the perioborite powder onto the fibers.

When producing the inorganic sheet of the present invention, a method of mixing a fibrous material and perovskite powder at a predetermined ratio to form an aqueous suspension, and then making paper from this using a normal paper making method. Can be adopted.

In addition, organic binders, binding aids, sizing agents, wet paper strength enhancers, etc., which are conventionally used in the papermaking process, may be added to the paper stock as necessary.

In the inorganic sheet of this invention, perioborite powder is added at 50@f
The reason for setting f1% or more is that if it is less than this, the desired flame retardant effect tends not to be obtained. The reason why the content of the fibrous material is 15% by weight or more is that if it is less than this, it becomes difficult to make paper using normal paper making, and the strength of the resulting sheet becomes weak.

As the inorganic powder fixed and carried on the fibrous material in the sheet of the present invention, the above-mentioned perioborite powder can be used alone, but it can also be used in combination with other inorganic powders if necessary. Such inorganic powders include metal hydrates such as aluminum hydroxide and magnesium hydroxide; metal oxides such as titanium diMide and alumina; metal carbonates such as calcium carbonate and magnesium carbonate; mica, vermiculite, and pearl. Examples include silicates such as rocks and obsidian. These inorganic powders can be used alone or in combination with the perioborite powder.

The 1fA embodiment, which is particularly preferable in terms of flame retardant performance, uses a mixture of perioborite powder and aluminum hydroxide powder as the inorganic powder. In other words, even when ashlarstone powder is used alone, it is possible to prevent the carbonized portion of the sheet from breaking through and to provide flame retardancy through dehydration.
Since cellulose fibers, which are the main component of fibrous materials, ignite and burn at around 250°C, the carbonization length according to the JIS A-1322 standard, which is a general evaluation of the flame retardant performance of flame retardant paper, tends to be slightly larger. Even if the carbonized portion does not penetrate through, the result will be that the flame retardant grade 1 in the JIS A-1322 standard is not met. On the other hand, when perioborite and aluminilla hydroxide are used together, aluminum hydroxide has a higher crystallization water content than perovorite (aluminum hydroxide: approximately 35%, perovorite: approximately 22%). ), near the ignition temperature of cellulose fibers (2
This results in an increase in the dehydration endothermic action (near O0'C) and an increase in the amount of steam generated due to dehydration, which is not possible with conventional methods, as it passes JIS A-1322 standard flame retardant class 1 and does not have carbonized parts missing or penetrating. Therefore, it becomes possible to provide an inorganic sheet with a high quality.

The type of inorganic powder to be mixed with perioborite can be selected from various types depending on the use of the inorganic sheet to be produced. A specific example will be given and explained below.

■ A mixed sheet made of perioborite and gold Ff compounds such as titanium oxide and alumina can be used for the purpose of maintaining fire resistance and sheet shape in a high temperature environment of 1000 to 1500' (:). In this case, If alumina fiber is used as the mixed inorganic fiber, the fireproofing effect will be further increased by 1q.

■ Mixed sheets of perioborite and metal carbonate minerals such as calcium carbonate and magnesium carbonate are JIS A-1.
It can be used for the purpose of responding to industries that do not require particularly high flame retardant performance, such as flame retardant class 2 or flame retardant class 3 in the 322 standard. In particular, calcium carbonate is an inexpensive material that can be largely self-sufficient in Japan, making it possible to reduce manufacturing costs. In this case, it is preferable from the economic point of view to use rock wool fibers, which are relatively inexpensive, as the inorganic fibers to be mixed.

■ A mixed sheet of perioborite and mica can be used as a flame-retardant electrical insulation sheet to impart flame retardance to electric wires and cables due to the electrical insulation and heat deformation resistance properties of mica itself. can.

■ Mixed paper sheets made from perovskite and silicate minerals such as vermiculite, nacre, and obsidian are used for foamed plastic insulation or heat retention due to the characteristics of these silicate minerals, such as light weight and nonflammability. It can be used as a lightweight flame-retardant sheet for industrial board products and as a flame-retardant base paper for gypsum boards. In the case of base paper for gypsum board, it is preferable to use masonry hydrate fibers as the inorganic fibers to be mixed.

<Examples> Examples and comparative examples of the present invention will be described in detail below. In addition, in these examples and comparative examples, "part" and "
%" is based on weight.

96 parts of softwood kraft pulp was beaten to a furnace water level of 300 mJ2 CSF using a beater set. For the purpose of improving paper strength, 4 parts of rock wool (ml < ts fiber system 5 μm, fiber length 3 mm) was added as an inorganic fiber under no load in a beater with a beater, and the paper material was thoroughly dispersed. Prepare.

The proportions of fibrous material and inorganic powder in the final paper sheet product are as shown in Examples 1 to 5 in the table below. A predetermined matrix of one or two types of inorganic powders was blended into the above paper stock material in the proportions shown in Comparative Examples 1 to 3, and 0.2% of an alkyl ketene dimer-based neutral sizing agent was added. (based on total solid weight) and a modified polyamide resin wet paper strength agent of 0.
Add 5% (based on total solids weight). Next, each sample was diluted with water until the total solids concentration was 0.75%, and then 0.2% polyacrylamide binding agent was added immediately before paper making.
(based on the total solid weight) and the sheet basis is 150
Paper is made on a square-shaped paper machine (-250 mm x 250 mm) for experimental purposes so that the paper size is 2 mm2.

A flame retardant performance evaluation test was conducted on each of the paper sheets of Examples 1 to 5 and Comparative Examples 1 to 3 thus obtained in accordance with JIS A-1322r "Flame retardant test method for thin materials for construction". The results are shown in the table below.

<Effects of the Invention> As is clear from this table, the sheet of Example 1, which is made of 40% fibrous material mainly composed of cellulose fibers and 60% perovskite powder, has a flame retardant level of 2 without penetration of carbonized parts. It is the one that passes the grade.

Further, the sheets of Examples 2 to 4 in which aluminum hydroxide was mixed with perioborite powder were flame-retardant sheets in which the carbonized portions were not cut through. In particular, the mixture of aluminum hydroxide and perovskite in the same amount (Example 3) and the mixture of aluminum hydroxide with more sides than perovskite (Example 4) passed the first grade flame retardant test. Moreover, it can be seen that a sheet can be obtained in which the carbonized portion does not break through.

On the other hand, in a sheet using only aluminum hydroxide as an inorganic powder, as can be seen from Comparative Examples 1 and 2, it is necessary to use 70% aluminum hydroxide in order to obtain a sheet that passes grade 1 flame retardant. However, even in this case, it is not possible to obtain a sheet in which the carbonized portion does not penetrate through the sheet. On the other hand, in the sheets of Examples 3 and 4, in which a mixture of aluminum hydroxide and ash was used as the inorganic powder, only 60% of the inorganic powder was used, and the sheets passed grade 1 flame retardant, and the carbonized portion It can be seen that the sheet without missing penetration is 1q.

In general, a sheet using only calcium carbonate as an inorganic powder (Comparative Example 3) burns and ashes even after heating for 10 seconds, whereas a sheet using the same IF compound of calcium carbonate and perovskite is used. As a result, a sheet was obtained that passed grade 3 flame retardancy and had no cracks or penetrations in the carbonized portion (Example 5).
It becomes possible to provide a relatively inexpensive flame retardant sheet.

As can be seen from the above explanation, the amorphous sheet of the present invention, which is made of a fibrous material mainly composed of cellulose fibers and carrying perioborite powder, is harmless and poses no problems in handling or manufacturing. It is possible to provide a flame retardant sheet with no cracks or penetrations in the carbonized parts.In particular, by using a combination of perioborite powder and aluminum hydroxide, flame retardant sheets with JIS A-1322 standard flame retardant grade 1 can be produced. It is possible to obtain a precipitate-free sheet that is an acceptable product, has no cracks or penetrations in the carbonized portion, and has a high degree of flame retardancy that has not been obtained in the past.

Therefore, this invention can appropriately meet the increasing demand for flame retardant and non-combustible materials in the building materials industry, which requires a high degree of safety and flame retardancy. For example, it can fully meet the demand for flame retardant electric wires and cables.

Patent applicant: Nippon Steel Mining Co., Ltd. Same Toyo Pulp Co., Ltd.

Claims (1)

[Claims] 1. Fibrous material mainly composed of cellulose fibers 15-50
1. An inorganic sheet comprising a sheet-like material in which 50 to 85% by weight of hydrated calcium borate powder represented by the chemical formula 2CaO.3B_2O_3.5H_2O is fixedly supported. 2. Fibrous material mainly composed of cellulose fibers 15-50
It consists of a sheet-like material in which 50 to 85% by weight of a mixture of hydrated calcium borate powder represented by the chemical formula of 2CaO.3B_2O_3.5H_2O and other inorganic powder is fixedly supported, and the other inorganic powder is
An inorganic sheet comprising one or more metal hydrates, metal oxides, metal carbonates, or silicates.