JPH07205349A - Incombustible honeycomb structural material and manufacture thereof - Google Patents

Abstract

PURPOSE:To reduce physical distribution cost and storage space by a method wherein elastical folding to before-expansion state is made possible. CONSTITUTION:Honeycomb structural material main body 1 consists of incombustible sheet 2 mainly made of sepiolite. Next, on the whole surface of the main body 1, aqueous dispersion liquid prepared by dispersing water glass composition, which is gelatinized in advance and then crushed to particles, in water is applied by immersion treatment or the like and dried. Thus, inorganic covering 4 made of water glass composition is integrally formed so as to cover the surface of the honeycomb structural material main body 1 made of incombustible sheet 2 under the condition that the surface is covered not by continuous filmy skin but by minute particles. Since the honeycomb structural material equipped with the inorganic covering 4 has proper elasticity and flexibility, the structural material can be folded again to before-expansion state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a partition wall material, shutter,
The present invention relates to a nonflammable honeycomb structure material used as a core material for building materials such as doors and floors, or a core material for interior panels of railway vehicles, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, since a panel for building materials such as a partition wall material has a light weight and strength, a large number of columnar cells having a hexagonal cross section are formed in a honeycomb shape by partition walls in the thickness direction. The honeycomb structure material thus prepared is used as a core material.

This honeycomb structure material is made of a sheet material, and a plurality of laminated sheets are bonded by alternately arranging adhesive strips at regular intervals and shifting them by a half pitch, and then cutting this into a desired width. It is generally manufactured by the method of spreading. As the sheet material, paper materials such as kraft paper are generally used because they are much cheaper than metal materials and easy to handle. However, since the honeycomb structural material formed from such kraft paper is made of an organic pulp material, it easily burns,
Further, it has a drawback that it is easily deteriorated by heat, and is unsuitable for applications requiring fire resistance or fire resistance.

Therefore, in order to improve the fire resistance of such a honeycomb structure material, as a sheet material used for forming the honeycomb structure material, a flame-retardant material made from a slurry containing a mixture of aluminum hydroxide and pulp as a main component. The use of paper has been proposed, for example, in JP-A-60-250945 and JP-A-63-178033.
And, the honeycomb structure material formed from this flame-retardant paper,
Then, in order to fix its expanded shape and impart compressive strength and rigidity to it, it is subjected to an immersion treatment with an aqueous inorganic impregnating liquid consisting of a water glass composition, and an inorganic hardened film of water glass is formed on the surface thereof. .

However, although the honeycomb structural material formed from such a flame-retardant paper can sufficiently achieve the purpose of flame-retardant, the flame-retardant paper contains a large amount of pulp in order to improve bending strength. Since it was contained at about 30%, it was still insufficient in terms of non-combustibility and high temperature durability.

[0006] Therefore, as a new material replacing the flame-retardant paper, the present applicant has focused on the natural mineral sepiolite and developed a non-combustible sheet (non-combustible paper) made from a slurry containing this as a main component. (For example, Japanese Patent Laid-Open No. 5-280
No. 121). This non-combustible sheet does not substantially require the blending of pulp because sepiolite is excellent in binding property and the like. Therefore, the honeycomb structure material formed from this noncombustible sheet has complete noncombustibility and excellent fire resistance. Incidentally, this non-combustible honeycomb structure material, similarly to the above-mentioned conventional example, after forming the main body of the honeycomb structure from the non-combustible sheet, it is immersed in an aqueous inorganic impregnating liquid consisting of a water glass composition, the surface It is manufactured by forming a cured film of water glass.

[0007]

As described above, the honeycomb structure material using the non-combustible sheet previously developed by the present applicant has complete non-combustibility and excellent fire resistance, and has a fireproof panel or fireproof property. It is extremely suitable as a core material for panels and the like. Moreover, since the main raw material is sepiolite, which is a natural mineral, it is inexpensive.

Therefore, the use and application of this non-combustible honeycomb structure material has been widespread, but the problem with it has been the problem of transportation and storage. That is, as described above, the non-combustible honeycomb structure material is impregnated with the water glass composition in order to increase the strength and maintain the expanded state. For this reason, this non-combustible honeycomb structure material is very bulky, not only requires a large space to store a large amount, but packing and transportation costs to remote areas in particular, compared to manufacturing costs. It was very expensive.

This problem of transportation and storage can be easily solved if the noncombustible honeycomb structure material can be refolded to the state before expansion. However, the inorganic cured film formed by the water glass composition formed on the surface of the non-combustible honeycomb structure material is a glass material that is hard but brittle, and the water glass composition impregnated into the honeycomb structure material is It forms a hard but brittle glassy matrix. Therefore, the non-combustible honeycomb structure material, when forcibly folded it, not only the film breaks and collapses,
At the bending point, the entire noncombustible sheet was broken, and the original honeycomb structure was not restored.

Therefore, an object of the present invention is to provide a non-combustible honeycomb structure material which can be refolded into a state before expansion and a manufacturing method thereof.

[0011]

A non-combustible honeycomb structure according to a first aspect of the present invention is a honeycomb structure main body formed from a non-combustible sheet containing sepiolite as a main component, and a water glass composition obtained by pre-gelling and pulverizing. And an inorganic coating integrally formed on the surface of the honeycomb structure body.

A method for manufacturing a non-combustible honeycomb structure material according to a second aspect of the present invention comprises a step of forming a main body of the honeycomb structure material from a non-combustible sheet containing sepiolite as a main component, and the surface of the main body of the honeycomb structure is pre-gelled. The method further comprises a step of applying an aqueous dispersion of the water glass composition that has been pulverized afterwards, and a step of drying the honeycomb structure main body coated with the aqueous dispersion.

Here, the water glass composition used for forming the inorganic coating is an aqueous solution containing an alkali metal silicate as a main component. This alkali metal silicate is represented by the general formula M ₂ O · nSiO ₂ , M is sodium Na, potassium K, or lithium Li, and the molar ratio of M ₂ O and SiO ₂ is. n is generally 1.
6 to 4.5. As such an aqueous solution of an alkali metal silicate, water glass of sodium silicate, which is inexpensive and easily available as a JIS standard product, can be particularly preferably used. Further, it is more preferable to use the water glass of sodium silicate mixed with the water glass of lithium silicate. Thereby, the water resistance after curing can be further enhanced.

In order to improve the water insolubility and heat resistance of the coating, it is preferable to use a curing agent in combination with this water glass composition. Various kinds of such curing agents have been conventionally known and used. Typical examples include oxides of polyvalent metals such as zinc oxide, hydroxides of polyvalent metals such as calcium hydroxide, silicides such as calcium silicate, silicic fluorides such as sodium silicofluoride, and boron. Examples thereof include borate salts such as potassium acid salt, phosphate salts such as aluminum phosphate, and a mixed calcined product of phosphoric acid and a metal oxide.

As described above, this water glass composition is used for forming an inorganic coating by pre-gelling, pulverizing and dispersing in water. The gelation can be performed by any method, but one preferable method is a method of gelling the water glass composition by adding the above-mentioned curing agent. Also,
A method using an inorganic material having a gelling ability such as swelling mica and smectite is also one of the preferable methods. Then, the gelled water glass composition is then pulverized into fine particles, and this pulverization is easily performed by, for example, adding water to the gelled water glass composition and mixing the mixture with a stirrer. It can be carried out. Then, the aqueous dispersion of the water glass composition which has been gelled and pulverized in advance is used in place of the aqueous solution of water glass used as the impregnating liquid in the conventional dipping treatment of the honeycomb structure main body. Applied on the surface of the body. And the honeycomb structure material body coated with this aqueous dispersion,
Then, it is dried by forced drying with hot air or natural drying, whereby an inorganic coating with water glass is formed.

[0016]

In the first aspect of the present invention, since the inorganic coating integrally deposited on the surface of the honeycomb structure body is formed from an aqueous dispersion of a water glass composition which has been gelled in advance and then ground, water glass The inorganic coating made of the composition of the inorganic polymer (polysilicate) is not applied as a continuous film-like coating, but is adhered integrally to the surface of the honeycomb structure body made of the non-combustible sheet in the form of particles, and , As a coating that fills at least the tissue gaps on its surface. Further, since the gelled pulverized particles of the water glass composition are not substantially impregnated into the inside of the tissue of the non-combustible sheet forming the honeycomb structure main body due to its adhesiveness, the flexibility of the non-combustible sheet is reduced. Maintained. Therefore, the honeycomb structure body integrally provided with the inorganic coating has flexibility and elasticity, and is elastically expandable and contractible in the expanding direction, and at the time of expansion and contraction, the inorganic coating is destroyed. , It won't fall. Therefore, this non-combustible honeycomb structure material can be folded again in the state before the expansion.

According to a second aspect of the present invention, a step of applying an aqueous dispersion of a water glass composition, which has been gelled in advance and pulverized, to the surface of the honeycomb structure body, and a honeycomb structure body coated with the aqueous dispersion are provided. Since it has a step of drying,
The water glass composition is applied to the surface of the body as a finely divided particulate gelled product, which is then cured by drying, substantially in the form of its particles. Therefore, the above-mentioned inorganic coating in a substantially particle state is formed on the surface of the honeycomb structure main body. Therefore, as a result, it is possible to manufacture a non-combustible honeycomb structure material that can be refolded to the state before expansion.

[0018]

EXAMPLES Examples of the present invention will be described below.

FIG. 1 is a perspective view showing a non-combustible honeycomb structure material according to an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a honeycomb structure body formed by laminating a plurality of non-combustible sheets 2 containing sepiolite as a main component using an inorganic adhesive 3 and expanding them.
As the inorganic adhesive 3, water glass type, phosphate type,
Although any adhesive such as colloidal silica-based adhesive and colloidal alumina-based adhesive can be used, in this embodiment, a colloidal silica-based adhesive having low permeability is used. Note that an organic adhesive such as vinyl acetate can be used instead of the inorganic adhesive, but the inorganic adhesive is more preferable in terms of fire resistance and heat resistance. Reference numeral 4 denotes an inorganic coating integrally deposited on the entire surface of the honeycomb structure body 1, and a water glass composition that has been gelled in advance and then pulverized, that is, a granular material of the gelled water glass composition is dispersed in water. It is formed from the above-mentioned aqueous dispersion.

Now, the non-combustible sheet 2 forming the honeycomb structure body 1 will be described.

Sepiolite, which is the main component of the non-combustible sheet 2, is a clay mineral commonly called mountain leather (mountain skin), mountain cork, mountain wood, and sepiolite in Japan is also one of them. The appearance may be cork-like, leather-like, or a pure white soft lump, but it is generally a magnesium silicate lump having fibrous properties. The surface thereof has a highly reactive hydroxyl group and has basic properties such as adsorptivity, thixotropy, and caking property.

The non-combustible sheet 2 is obtained by paper-making the slurry containing sepiolite as a main component, and is generally a thin sheet having a thickness of 0.3 to 0.5 mm. This non-combustible sheet may be made of sepiolite alone, but preferably inorganic fibers are added for reinforcement. Glass fiber, rock wool fiber, stainless fiber etc. can be used for this purpose,
Generally, it is blended in a ratio of up to 20% by weight (based on the whole noncombustible sheet). For the purpose of this reinforcement, organic fibers such as wood pulp or aramid fibers can also be used, but it is desirable that the blending amount thereof be kept to 5% by weight or less, whereby the flame retardancy and after thermal decomposition The sufficient shape retention property is maintained. Further, a thermosetting or thermoplastic synthetic resin can be used as a binder for increasing the binding property of the noncombustible sheet. However, since sepiolite is excellent in caking property, even when these synthetic resins are used as a binder, the addition amount thereof is 5% by weight or less. And such an added amount does not substantially affect the incombustibility.

In this embodiment, the non-combustible sheet 2 is composed of 85% sepiolite (weight, the same applies hereinafter), 10% glass fiber,
Pulp 3%, vinylon fiber 1%, acrylic resin 0.
5% and 0.5% of epoxy resin. Here, the total amount of organic components such as pulp is 5% by weight, and although this organic component is carbonized under the heating temperature condition of 800 to 1000 ° C., the strength of the carbonized sheet hardly deteriorates and sufficient. Has heat-resistant shape retention. Further, this nonflammable sheet does not redissolve even when immersed in water, and its strength is not significantly reduced. The nonflammable sheet used in this example has a thickness of about 0.4 mm.

Using the non-combustible sheet 2 as described above, the honeycomb structure body 1 can be formed by a conventional and well-known method, for example, as follows. That is, first, the inorganic adhesive 3 is applied to the surface of the sheet-shaped noncombustible sheet 2 in a stripe shape at a predetermined interval at a predetermined interval by screen transfer or roller application. The width of the strip of the inorganic adhesive 3 determines the length of the overlapping portion of the honeycomb structure body 1, and the honeycomb structure body 1 is formed by changing the width and pitch of the strip of the adhesive 3. The shape and size of the cells can be varied as desired. Then, a large number of the sheet-shaped non-combustible sheets 2 on which the strips of the inorganic adhesive 3 are formed are arranged so that the strips of the adhesive 3 are displaced from each other by a half pitch between the adjacent non-combustible sheets 2. And stack them together and press them from the top and bottom to bond them together. Next, this block composed of a large number of non-combustible sheets 2 adhered to each other is cut in a direction perpendicular to the line of the adhesive 3 into a predetermined width corresponding to the desired thickness of the honeycomb structure material. Then, the honeycomb structure main body 1 is formed by expanding the cut object from both sides. Although the expansion of the honeycomb structure main body 1 can be performed as an independent process, it is preferably performed together with the dipping treatment for forming the inorganic coating 4, and the honeycomb structure main body 1 is expanded in the treatment tank. Immerse or expand while being immersed in the treatment tank.

Then, the formed honeycomb structure body 1
Is then dip-treated to form the inorganic coating 4. The treatment liquid used for this immersion treatment consists of an aqueous dispersion of a water glass composition which has been gelled in advance and then pulverized.
In this example, this aqueous dispersion was prepared as follows.

To 100 parts by weight of sodium silicate JIS No. 3 (solid content of sodium silicate: 38.5%), 2 parts by weight of sodium silicofluoride was added as a curing agent, and the solution was kept at 50 to 70 ° C. While stirring, the mixture was stirred for about 3 hours. Then, after this stirring, the solution was left in a room at about 20 ° C. to be cooled and gelled. Then add 400 parts of water to the gel.
By adding parts by weight, high-speed stirring was performed for about 1 hour under room temperature conditions. As a result, an aqueous dispersion liquid in which the water glass gel was pulverized into fine particles and dispersed in water was obtained. The composition of this aqueous dispersion is as shown in Table 1 below.

[0028]

[Table 1]

Then, the honeycomb structure body 1 is dipped in a treatment tank filled with this aqueous dispersion and then pulled up to apply the aqueous dispersion on the entire surface thereof. The application of this aqueous dispersion can be carried out by other application methods such as spraying, but the method of dipping treatment is most preferable in that uniform application is possible. Next, the honeycomb structure main body 1 coated with the aqueous dispersion described above is dried by this dipping treatment to remove water impregnated inside the main body 1, and the coating film of the aqueous dispersion is dried to form a water glass. The inorganic coating 4 is formed. In addition, in this example, this drying was performed by natural drying. Drying with hot air is also suitable for a large amount of treatment because the drying time is short, but gradually drying by natural drying causes less warpage of the main body 1 and a good inorganic coating 4 Can be formed.

In this way, it is possible to obtain a noncombustible honeycomb structure material in which the inorganic coating 4 is integrally formed on the surface of the main body 1 made of the noncombustible sheet 2. Here, the inorganic coating 4 enhances the tensile strength and compressive strength of the non-combustible sheet 2 forming the main body 1, and also holds the main body 1 in the expanded state of the honeycomb structure. Further, the fibers on the surface of the non-combustible sheet 2 are prevented from fuzzing or peeling off, and further the fire resistance of the non-combustible sheet 2 is improved.

Since the inorganic coating 4 is formed from an aqueous dispersion of a water glass composition which has been gelled and then ground, the ground particles of the water glass composition gel adhering to the surface of the main body 1 are By drying, it cures substantially in the form of its particles. For this reason, the coating 4 is not a cured film of an inorganic polymer of a water glass composition, not as a continuous film-like film, but in the state of particles substantially independent of each other, at least the texture of the surface of the main body 1 It is formed as a coating applied to fill the gaps, increasing the rigidity of the surface. Further, the gel particles of the water glass composition are not substantially impregnated into the inside of the tissue of the noncombustible sheet 2 forming the main body 1 due to its adhesiveness, so that the flexibility of the noncombustible sheet 2 is maintained. It Therefore, the non-combustible honeycomb structure integrally provided with the inorganic coating 4 on the surface of the main body 1 has appropriate flexibility and elasticity, and can elastically expand and contract in the extending direction. You can also fold it before spreading. Further, during the folding, the transient shear stress does not act on the coating 4, so that it is not broken and does not fall.

The aqueous dispersion for forming such an inorganic coating 4 is not limited to the above-mentioned example, but various changes can be made in composition. For example, the following Table 2
It is also possible to have a composition of

[0033]

[Table 2]

This aqueous dispersion was prepared in the same manner as the above-mentioned aqueous dispersion, but primary particles of sepiolite were further added to the water glass composition before gelation. As a result, the strength of the coating is increased, and since sepiolite has a high adsorptivity, the adherence of the coating is improved.

Further, in these examples, sodium silicofluoride is used as a hardening agent for gelling the water glass composition. As such a hardening agent, a desired gelling rate and gel Appropriate types can be used in an appropriate blending amount depending on hardness and the like. Further, gelation of the water glass composition can be carried out by adding an inorganic substance having a gel forming ability such as swelling mica and smectite.

[0036]

As described above, the non-combustible honeycomb structure according to the first aspect of the present invention comprises a honeycomb structure main body formed from a non-combustible sheet containing sepiolite as a main component, and water which has been previously gelled and then pulverized. An inorganic coating formed from an aqueous dispersion of a glass composition and integrally applied to the surface of the honeycomb structure body.

Accordingly, since the inorganic coating is substantially adhered to the surface of the main body of the honeycomb structure made of the non-combustible sheet in the form of particles, it is not broken and collapsed even when bent. In addition, it also provides the body with appropriate flexibility and elasticity. Therefore, since the honeycomb structure material can be packed, transported, stored, and the like in a folded state before being expanded, physical distribution cost, storage space, and the like can be significantly reduced. Further, this honeycomb structure material can be easily expanded again due to its elasticity, and the expansion rate can be arbitrarily adjusted according to the desired compressive strength. Further, since it has appropriate flexibility, surface strain is easily eliminated, and the core pattern does not stand out even when a thin surface material is attached. Furthermore, since the adhesive has good permeability, the adhesiveness of the hot-melt adhesive is also good.

A method for manufacturing a non-combustible honeycomb structure material according to a second aspect of the present invention comprises a step of forming a main body of the honeycomb structure material from a non-combustible sheet containing sepiolite as a main component, and a gel preliminarily formed on the surface of the main body of the honeycomb structure material. After this, it comprises a step of applying an aqueous dispersion of the crushed water glass composition, and a step of drying the honeycomb structure material body coated with the aqueous dispersion. Therefore, the conventional, since the aqueous inorganic impregnating liquid used for the immersion treatment, after gelling in advance, is only used instead of the aqueous dispersion of the crushed water glass composition, it is nonflammable having the above-mentioned effect. The honeycomb structure can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing a non-combustible honeycomb structure material according to an embodiment of the present invention.

[Explanation of symbols]

 1 Honeycomb structure material main body 2 Non-combustible sheet containing sepiolite as a main component 3 Inorganic adhesive 4 Inorganic coating

Claims (2)

[Claims] 1. A honeycomb structure main body formed from a non-combustible sheet containing sepiolite as a main component, and an aqueous dispersion of a water glass composition which has been gelled in advance and then crushed to form a honeycomb structure main body. A non-combustible honeycomb structure material comprising an inorganic coating integrally deposited on the surface. 2. A step of forming a honeycomb structure main body from a non-combustible sheet containing sepiolite as a main component, and a step of pre-gelling the surface of the honeycomb structure main body,
A method for producing a non-combustible honeycomb structure material, comprising: a step of applying an aqueous dispersion liquid of the crushed water glass composition; and a step of drying the honeycomb structure material main body to which the aqueous dispersion liquid is applied.