JP2505307B2 - Non-combustible paper - Google Patents

Description

TECHNICAL FIELD The present invention relates to a nonflammable paper used as a wall covering, a heat-resistant decorative sheet, etc., and particularly has nonflammability as an asbestos substitute paper, and , Non-combustible paper excellent in paper strength and productivity.

[Prior Art] In recent years, due to the social needs related to the prevention of fire accidents, flameproofing of building interior materials, etc. along with plastics, clothing, etc.
Issues such as fire resistance have been addressed, and it has become fairly regulated. As with paper materials, there is a high demand in the market for so-called flameproof / noncombustible paper, which does not burn and is resistant to heat, including wall coverings.

Heretofore, asbestos fiber paper has been typified as a general-purpose non-burnable paper in inorganic fiber type. This asbestos fiber paper excels in all aspects such as flame retardancy, heat resistance, high strength, easy productivity, low price, etc. It covers a range of applications that are difficult for organic fibers and has a wide range of uses.

Here, if you touch the characteristics of this asbestos,
Ore such as olivine and pyroxene is fibrous crystallized into serpentine and amphibolite by geothermal heat and hydrothermal action of groundwater in the crust under high pressure. Among them, many of the varieties used as raw materials for papermaking are serpentine chrysotile asbestos, whose chemical formula is 3MgO · 2SiO ₂ · 2H ₂ O. The fiber diameter is 20-40 nm, which is extremely thin and flexible. Hardness 2.5
It is as low as ~ 4.0, which is why it is used as a friction material. Further, when it is made into paper, it has good compatibility with water because it contains water of crystallization. In the case of mixing with other additives, chrysotile has good adsorption and scavenging properties because the charge in water is cation. When the paper sheet is used, these physical properties have various advantages such as strong, non-burning, soft, smooth and easy to make.

However, asbestos has recently become unusable in Japan due to its harmful effects on health. In Western Europe, it is almost unusable.

From this situation, with the development of new materials, development of alternative materials similar to asbestos is being actively researched in various places, and high-performance inorganic fibers and whiskers are being developed one after another. For example, pitch-based general-purpose carbon fibers, potassium titanate fibers, alumina-silica fibers, glass fibers and the like are used rather widely. In addition, gypsum fiber, basic magnesium sulfate fiber, phosphate fiber, magnesium pyroborate fiber and the like are also available. However, in reality, these fibers have not reached the level of alternatives to asbestos in terms of use, productivity, price, etc.

In addition, there is a flameproofing method as a method of making a paper that does not burn easily. This is a method found in wallpaper, shoji paper, paper heat exchangers, etc., and can be said to be a treatment method that does not ignite. The base material is one obtained by impregnating or coating a wood pulp paper such as kraft paper with a flameproofing agent, an ammonium-containing salt type aqueous inorganic salt, a phosphorus-containing nitrogen compound, a phosphorus-containing halogen compound, an antimony trioxide-halogen compound, a boron compound, A halogen compound or the like is used. However, this treatment is mainly based on so-called organic substances and cannot be said to be completely non-combustible. Aromatic polyamide fibers are also used as high-performance fibers, but they are not widely used.

Under such circumstances, there has been a strong demand from a social and industrial point of view to develop a surface that cannot use asbestos fiber paper by using another fiber. From a general-purpose application, there is a need for a wide range of applications such as wall coverings, sealing materials, gaskets, packing, asphalt roofing, cushion floors, incombustible cores, building material covering paper, laminated paper, and heat insulating materials.

Under these circumstances, the possibility of using sepiolite as an alternative to asbestos among the existing natural fiber products is drawing attention.
There are also many cases of paper materials (sheets) that use sepiolite.

Here, sepiolite is a clay mineral commonly referred to as mountain leather, mountain cork, and mountain wood, and sepiolite in Japan is also a kind of this. Although the appearance may be cork-like, leather-like, or a pure white soft lump, it is generally a lump of hydrous magnesium silicate clay mineral having fibrous properties. For the time being, although it is classified as a one-dimensional structure clay, it can be considered as a crystalline three-dimensional structure of bricks that can be easily shaved in a certain direction depending on the viewpoint, and a crystal form group consisting of silicon, magnesium, oxygen, hydroxyl group, and crystal water is formed. Is forming. Physical properties have basic properties such as adsorption, thixotropy, and solidification.

Examples of papermaking utilizing this characteristic include, for example, JP-A-51-88779, JP-A-56-165097, JP-A-58-95636, and JP-A-58-144196. Kaisho 5
9-21800, JP 61-258099, JP 63-
There are technologies disclosed in Japanese Patent No. 235600, Japanese Patent Laid-Open No. 64-61599, and the like.

[Problems to be Solved by the Invention] The above publication discloses that inorganic fibers such as ceramic fibers or cloth, that is,
In many cases, sepiolite, which is rich in adsorptivity, thixotropy, and solidification, is mixed, dispersed, treated, and dried in organic fibers or fibers composed of both. this is,
Since sepiolite is a fine fiber, when papermaking as a paper material, drainage is poor, it is difficult to form an arbitrary sheet, and it is difficult to make paper using sepiolite as a main raw material due to reasons such as poor tear strength. It depends. Therefore, the excellent characteristics of sepiolite have not been fully utilized. Japanese Patent Laid-Open No. 59-21800 discloses a single use of sepiolite fiber alone, but lacks a specific technical content, which is not practical.

By the way, as described above, the wall paper is required to have flameproofness and nonflammability in terms of flameproofness. On the other hand, in a humid country such as Japan, the building material may swell by absorbing water, and the wall paper may be deformed or broken by repeated swelling and drying. Therefore, in addition to flameproof and nonflammable,
Water resistance is also required.

On the other hand, in the above publication, there is almost no description of a technique relating to water resistance. In Japanese Patent Laid-Open No. 59-21800, there is described a technique for improving the water resistance, heat resistance and chemical resistance by mixing a small amount of a resin such as silicone or Teflon as an inorganic filter paper. Is a filter paper,
In addition, the specific technical contents are not specified, and there is a possibility that the practicality is lacking as in the above.

Therefore, the present invention has both noncombustibility and water resistance, and can secure paper strength at the time of dry and wet, and further, to provide an inexpensive noncombustible paper excellent in productivity To do.

[Means for Solving the Problems] The non-combustible paper according to claim 1 contains sepiolite as a main material in a proportion of 80% by weight or more based on the entire raw material, and is made of a thermosetting resin. Binder and molecular weight
A second binder for aggregation consisting of 8-10 million anionic polyacrylamide and a third binder for strengthening paper consisting of anionic polyacrylamide with a molecular weight of 800,000-1 million
It is formed by making a slurry containing a binder.

Further, in the non-combustible paper according to claim 2, in the claim 1, the slurry further contains an inorganic fiber as a reinforcing material.

[Operation] In the non-combustible paper according to claim 1, the main ingredient is sepiolite, which is a clay mineral composed of hydrous silicon magnesium, has high heat resistance, is non-swelling with respect to moisture, and is inexpensive. Since a slurry containing 80% by weight or more of the whole raw material is made into paper, it can have both noncombustibility and water resistance depending on the characteristics of the sepiolite, and can be manufactured at low cost. In addition, the third binder for strengthening the paper strength, which is composed of anionic polyacrylamide having a molecular weight of 800,000 to 1,000,000, which is added to the slurry, contributes to the strengthening of the paper strength, and thereby the strength of the non-combustible paper at the time of drying. The first binder for consolidating, which is composed of a thermosetting resin,
It heat-cures to form a polymer compound with a network-like three-dimensional structure, which solidifies the raw materials mainly composed of sepiolite, thereby improving the strength of the non-combustible paper when it is wet. Can be secured. Furthermore, the molecular weight is 8 million to 1
The second binder for agglomeration consisting of 10 million anionic polyacrylamide agglomerates and focuses the sepiolite in the slurry to form coarse flocs, which improves the drainage of the slurry and is a non-combustible material mainly composed of sepiolite. It is possible to improve the productivity by papermaking of the elastic paper.

In the non-combustible paper according to claim 2, since inorganic fibers as a reinforcing material are further added, the strength and physical properties of the non-combustible paper mainly composed of sepiolite are improved without impairing its non-combustibility and water resistance. can do.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is an explanatory view showing an outline of a manufacturing process of nonflammable paper in one embodiment of the present invention.

In this example, in order to make the best use of the characteristics of sepiolite, the sepiolite was made to be 80% or more based on the whole raw material, and a binder or the like was added to this to make a slurry to make a paper. Usually, when the sepiolite rich is used, since sepiolite is fine fibers, the drainage property at the time of papermaking is poor, and a paper of an arbitrary thickness cannot be produced. In particular, when a continuous paper machine is used, a machine weighing 200 g / m ² or more does not match the paper making speed. On the other hand, when the thickness is around 100 g / m ² or less, there is no wet paper strength immediately after paper making, and there is a problem in continuous paper making property such as water squeezing and conveyance by machine. Therefore, in this development research, while devising and improving an appropriate papermaking device, in particular, an appropriate binder was selected and combined.

First, the manufacturing process of the nonflammable paper in this embodiment will be described.

In Fig. 1, in the defibration step 1, the main raw material sepiolite and the glass fiber as a reinforcing material are put into a defibrating machine, and the sepiolite composed of a lump of fine fibers is sufficiently defibrated by stirring to disperse the dispersion. And to mix it homogeneously with the glass fiber. Therefore, this defibration process
It is also an important process for obtaining smooth non-combustible paper with fine grain.

Next, in the raw material mixing step 2, the sepiolite that has been defibrated and mixed with the glass fiber is used as a binder, a softening agent,
It is put in a mixing tank together with a stabilizer and the like and mixed with water to prepare a slurry. Here, as the binder, in order to enhance the paper strength of the resulting noncombustible paper, particularly when wet,
A thermosetting resin that is thermoset to form a polymer compound having a three-dimensional network structure is used as a first binder for consolidation,
Of these thermosetting resins, EPA (polyamide polyamine epichlorohydrin, epoxidized polyamide polyamine)
It was used. In addition to the first binder made of EPA, a second binder made of PAA (polyacrylamide) for coagulation having a molecular weight of 8 million to 10 million and a molecular weight of 800,000 to
A third binder of PAA (polyacrylamide) for paper strength enhancement was used together.

Next, the slurry mixed in the raw material mixing step 2 is subjected to a bundling process by a stock material bundling reaction device in a paper material bundling process step 3. That is, in this paper making process 3, the coagulation of sepiolite dispersed in water and the fixing of the first binder and the third binder for enhancing the paper strength are promoted, and the third binder for aggregating is promoted. The floc is coarsened by. In this way, by this stocking treatment step 3, coarsened flocs are generated, and a slurry with improved papermaking property is formed. Since the slurry is bundled in the paper making process step 3, the second binder can be added in this step.

The slurry prepared as a stock in the stock making process 3 is sent to a stock tank and accumulated so that the mixed state is always uniformed so that sedimentation separation or collapse of the prepared stock does not occur. Step 4 is entered.

The slurry accumulated in the stock tank in the accumulation step 4 is pumped up to the quantitative hopper, and the slurry measured by the quantitative hopper is then introduced to the papermaking step 5.

Then, in this papermaking step 5, the slurry containing sepiolite as a main material and in which coarse and good flocs are formed is made into paper by a continuous paper machine or the like. In this example, papermaking was carried out using a round net paper machine. At this time, the slurry concentration was 0.5 to 1.0%, and the paper machine used was 60 to 80 mesh. Then, when the slurry in which the flocculation flocs are formed flows into the papermaking net, water quickly flows down from the nets through the flocculation flocs to form a paper layer.

After this, this paper layer is pressed and dehydrated in a drying step 6, and the dehydrated wet paper is dried for a predetermined time at a temperature of about 120 ° C., for example, by a steam rotary dryer. By this heating and drying, the water inside the paper layer is evaporated, and the curing and condensation of the binder is promoted and the binder is dried and solidified. Then, the dried non-combustible paper is peeled off from the dryer surface of the steam rotary dryer to form a roll paper.

By the above, nonflammable paper with a thickness of 0.1 to 1.0 mm is completed. This non-combustible paper has high heat resistance and fire resistance, generates a slight amount of smoke even when approaching a fire by a gas burner, and is only blackened, and retains its initial shape. That is, it is virtually completely nonflammable.

Here, the results of research on the agglomeration of the slurry to improve drainage will be described.

As a binder for agglomeration of this slurry,
A second binder, i.e., anionic PAA (polyacrylamide), which is ionically bonded to magnesium ions, which are metal ions in the composition of sepiolite, or a cationic substance to aggregate and bind the fine fibers of sepiolite was selected. The second binder for aggregation, PAA, is a high molecular weight resin polymer having a molecular weight of 8,000,000 to 10,000,000, and has a large attraction force (cohesion energy) between the molecules of the polymer. Regarding the binding between this PAA and sepiolite, the magnesium ion of sepiolite and PAA
It is considered that a linearly extended bridge structure is formed by repulsion with the amide group of.

In this development study, first, the blending ratio of this PAA (second binder) for aggregation was examined.

As the processing conditions, a papermaking tool of 150 × 150 mm size and 80 mesh of papermaking were used, and the raw material was 85% by weight of sepiolite and 15% by weight of glass fiber as a reinforcing material, and 2.5 g of this was disintegrated and dispersed in 100 ml of water. . Cationic EPA (polyamide polyamine epichlorohydrin), which is the first binder for consolidation, was added as fixed conditions to each sample in an amount of 2.0% by weight in terms of solid content, and the amount of PAA for aggregation was calculated. I changed it to 2. And the papermaking concentration is 2.5g / 1000ml (0.25%)
After the dilution, the drainage was judged by measuring the drainage time of 1000 ml of this slurry.

FIG. 2 is for aggregating non-combustible paper in one embodiment of the present invention.
It is a table which shows the test result about the relationship between the addition amount of PAA (2nd binder), and drainage.

As shown in FIG. 2, as the addition amount of PAA for coagulation is increased, the drainage time is shortened and drainage is improved. However, in the case of adding 0.3% by weight of this (No. 5), the focused lumps (flocks) were too large, and the texture of the obtained noncombustible paper tended to deteriorate. Therefore, the amount of the second binder made of anionic PAA having a molecular weight of 8 to 10 million is preferably around 0.2% by weight.

Next, the relationship between the added amount of the paper strengthening agent and the drainage will be described.

As the paper-strengthening agent, as described above, the third binder for strengthening paper-strength is an anionic PAA having a molecular weight of 800,000 to 1,000,000.
(Polyacrylamide) was selected. The anionic PAA is obtained by changing a part of the amide group to a carboxyl group, like the PAA for aggregation as the second binder. Since this PAA is a relatively low molecular weight thermoplastic resin polymer, it has good dispersibility, and since it is anionic, it has good fixability to cation-charged sepiolite. Therefore, the strength of the non-combustible paper when dried is favorably improved.

As a fixing condition, the second binder, PAA for aggregation
Is 0.2% by weight with good drainage by the above test, and EPA as the first binder is 2.0% by weight as above.
I made it. The processing conditions were the same as above.

Results are shown in FIG. FIG. 3 is a table showing the test results of the relationship between the amount of paper strength enhancer added to nonflammable paper and drainage in one example of the present invention.

The third binder used, PAA for strengthening paper strength, has a high viscosity, and when the amount added is 3.0% by weight or more, No. 4 or more, the aggregate tends to gel, and the drainage is good. Absent. Therefore, this anionic P with a molecular weight of 800,000 to 1,000,000
The addition amount of the third binder composed of AA is 1.0 to 2.0% by weight.
Is preferred.

Next, EP, which is the first binder made of thermosetting resin
The tendency of physical properties was investigated by increasing and decreasing A (polyamide polyamine epichlorohydrin).

As fixing conditions, the second binder PAA (for aggregation) was 0.2% by weight, and the third binder PAA (for paper strength enhancement) was 2.0% by weight. The processing conditions were the same as above.

The test results are shown in FIG. FIG. 4 is a table showing the test results of the physical property tendency of the non-combustible sheet according to one embodiment of the present invention due to the increase / decrease in EPA (first binder).

As shown in Fig. 4, the more the EPA, which is a thermosetting resin, is mixed, the more the wet tensile strength increases along with the tensile strength at the time of drying. They are high. Therefore, 2.0% by weight is preferable as EPA which is the first binder for consolidation. However, if it exceeds 2.0% by weight, the amount of organic components will increase and it will deviate from the intent of nonflammability, so 2.0% by weight was made the upper limit.

By the way, in this test, in order to further improve the paper strength, glass fiber as a reinforcing material is added.

With respect to this glass fiber, the mixing ratio to sepiolite and the fiber length were changed, and the strength and drainage were examined. Specifically, the fiber lengths were set to 3, 6, and 13 mm, and the mixing ratio was changed to 5, 10, 15, and 20% by weight for each.

As a result, a fiber having a fiber length of 13 mm and a mixing ratio of 15 to 20% by weight was the best overall strength and drainage property. It is considered that glass fiber also has a function of promoting aggregation as a filler.

Regarding the strength of the non-combustible paper when wet in the present example, the sample of No. 4 in Fig. 4 and a commercially available sample (flame-retardant paper, aluminum hydroxide paper composed of wood pulp and aluminum hydroxide powder) Fig. 5 shows an example of comparison between and.

FIG. 5 is a table comparing the in-water elongation of non-combustible paper and commercially available flame-retardant paper (aluminum hydroxide paper) in one example of the present invention.

As shown in Fig. 5, in the longitudinal direction, after immersion for 1 hour,
Although there is no difference between the sample of the example of the present invention and the commercially available sample in any of the samples after 24 hours of immersion, the elongation of the sample of the example of the present invention is obviously small in the lateral direction, and the sample of the present invention is generally comprehensive. The example samples show excellent wet strength.

In the commercially available sample (aluminum hydroxide paper), the longitudinal and lateral elongations are significantly different from each other because the fiber orientation of wood pulp tends to be aligned vertically during papermaking, the degree of entanglement of fibers increases and the elongation decreases. On the other hand, it is considered that the elongation increases because the fiber entanglement degree is small in the lateral direction.

On the other hand, the samples of the examples of the present invention do not use wood pulp, and since sepiolite is the main material and has a relatively short fiber length, the fiber orientation is small, and integrated with fine glass fibers. It is considered that the difference between the length and the width is small because the bundled fibers are formed.

As described above, the non-combustible paper of this example contains sepiolite as a main material in a ratio of 80% or more with respect to the entire raw materials,
The first binder for consolidation consisting of polyamide polyamine epichlorohydrin (epoxidized polyamide polyamine, EPA) which is a thermosetting resin, and the first binder for aggregation consisting of anionic polyacrylamide (PAA) with a molecular weight of 8-10 million. It is prepared by making a slurry by adding 2 binders and a third binder for strengthening paper strength made of anionic polyacrylamide (PAA) having a molecular weight of 800,000 to 1,000,000.

Therefore, according to the non-combustible paper of this example, the main material is
That is, 80% or more of the raw material is a clay mineral composed of hydrous magnesium silicate and inexpensive sepiolite, so that it has excellent noncombustibility, and sepiolite itself is water-insoluble. Since it does not swell even when it absorbs water, it also has good water resistance (moisture resistance) and can be manufactured at low cost. Further, unlike the case of pulp paper or flame-retardant paper containing a relatively large amount of pulp,
Molds do not propagate or rot.

Further, since the first binder to the third binder are added to the slurry containing sepiolite as a main material, the third binder composed of a relatively low molecular weight anionic PAA contributes to the enhancement of paper strength, and The first binder made of EPA, which is a thermosetting resin, can improve and secure the strength of the non-combustible paper when dried, and the first binder made of thermosetting resin EPA is a polymer compound having a three-dimensional network structure by thermosetting. And the raw material containing sepiolite as a main material is stably consolidated in water, whereby the strength of the non-combustible paper when wet can be improved and ensured. Also,
The second binder, which is a relatively high molecular weight anionic PAA, acts as a flocculant, flocculates sepiolite in the slurry, and makes flocs coarser to improve drainage and papermaking properties. It is possible to improve the productivity of non-combustible paper mainly made of sepiolite.

In this example, glass fiber as a reinforcing material was further mixed in the above slurry. for that reason,
Due to the reinforcing effect of this inorganic glass fiber,
The strength and physical properties of the nonflammable paper can be further improved without impairing the nonflammability. Further, since glass fiber is an inexpensive material together with sepiolite, the non-combustible paper can be manufactured at low cost.

By the way, in the non-combustible paper of the above-mentioned embodiment, glass fibers are mixed as a reinforcing material, but other inorganic fibers can be optionally used. In addition to this, wood pulp,
Organic fibers such as synthetic fibers can also be used within a range that does not impair incombustibility.
It can be blended appropriately. However, it is not always necessary to mix the reinforcing material depending on the intended use of the nonflammable paper.
Then, by omitting the use of the reinforcing material, the mixing process of the reinforcing material can be omitted and the work can be simplified. However, by mixing the glass fibers, not only the strength of the paper strength can be enhanced, but also a smooth feeling can be given to the nonflammable paper which feels hard.

In addition, in the present embodiment, polyamide polyamine epichlorohydrin (EPA) is used as the first binder for consolidation made of a thermosetting resin, but the present invention is not limited to this. Not urea-formaldehyde (UF), melamine-formaldehyde (MF), polyethyleneimine epichlorohydrin (PE
Other thermosetting resins such as I) can be used. And these thermosetting resin may be used individually, respectively, or may be used in mixture of 2 or more types.

Further, the mixing ratio of the sepiolite, the reinforcing material, and the first binder to the third binder in the above examples is not limited thereto, and an optimum one may be selected according to the physical properties, drainage, papermaking method, intended use, etc. You can select it. However, sepiolite is used as the main material for all raw materials.
The proportion is preferably 80% or more, whereby excellent nonflammability as a nonflammable paper and good water resistance can be secured.

The non-combustible paper of the present invention can be used for wall covering materials, sealing materials, architectural surface covering paper, etc., but in addition, by sticking on both sides of the heat insulating material, It can also be used to prevent fluffing and falling off. Alternatively, they can be laminated to form a heat insulating material, and can also be used as an insulating material. Further, the molded body can be formed into a paper having a thickness of about 10 mm, and can be used as a noncombustible board, for example. Further, since it is possible to make paper in a concavo-convex shape, it can be used as a non-combustible material having a three-dimensional shape.

[Advantage of the Invention] As described above, the non-combustible paper according to claim 1 contains sepiolite as a main material in a proportion of 80% by weight or more based on the whole raw material, and is made of a thermosetting resin. 1 binder and a second binder for aggregation composed of anionic polyacrylamide (PAA) having a molecular weight of 8 to 10 million,
Anionic polyacrylamide with a molecular weight of 800,000 to 1,000,000 (P
It is made by making a slurry containing a third binder for strengthening paper strength, which is composed of AA).

Therefore, according to this non-combustible paper, it is a natural mineral, has high heat resistance, and is non-swellable with respect to moisture,
Moreover, since a low-priced slurry containing sepiolite as a main material is formed into paper, there is an effect that it has both noncombustibility and water resistance and can be manufactured at low cost. Further, since the first binder for consolidation and the third binder for strengthening the paper strength are added to the slurry, it is possible to improve and secure the paper strength of the non-combustible paper during drying and wet. , Because the second binder for aggregation is added,
Sepiolite in the slurry can be aggregated and focused to form coarse flocs, which can improve drainage and enhance papermaking, and the productivity of non-combustible paper based on sepiolite. There is an effect that can be improved.

Further, in the non-combustible paper according to claim 2, in the claim 1, the slurry further contains an inorganic fiber as a reinforcing material. Therefore, according to this non-combustible paper, in addition to the effect of claim 1, there is an effect that the strength physical properties of the non-combustible paper can be further improved.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of a manufacturing process of nonflammable paper in one embodiment of the present invention. FIG. 2 shows a PA for aggregating non-combustible paper in one embodiment of the present invention.
It is a table showing the test results about the relationship between the addition amount of A (polyacrylamide, the second binder) and drainage. FIG. 3 is a table showing the test results of the relationship between the added amount of the paper strengthening agent (PAA for paper strength, third binder) and the drainage of non-combustible paper in one example of the present invention. FIG. 4 is an EP for consolidation of nonflammable paper in one embodiment of the present invention.
It is a table showing the test results of the physical property tendency due to increase and decrease of A (polyamide polyamine epichlorohydrin, first binder). FIG. 5 is a table comparing the in-water elongation of non-combustible paper and commercially available flame-retardant paper (aluminum hydroxide paper) in one example of the present invention. In Fig. 1, it is 1: defibration process, 2: raw material mixing process 3: paper making process, 4; accumulation process 5: papermaking process, 6: drying process.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Koji Tsuchiya, 65, Metal Complex, Kakamigahara City, Gifu Prefecture, Tokiwa Electric Co., Ltd. (56) References JP 60-231899 (JP, A) JP 63-201048 (JP, A) JP-A-54-3868 (JP, A)

Claims (2)

(57) [Claims] 1. A first binder for consolidating, which is composed of thermosetting resin and contains sepiolite as a main material in a proportion of 80% by weight or more, and an anionic polyacrylamide having a molecular weight of 8 to 10 million. A non-combustible paper characterized by being produced by making a slurry into which a second binder for agglomeration consisting of the above and a third binder for strengthening the paper consisting of anionic polyacrylamide having a molecular weight of 800,000 to 1,000,000 are added. 2. The nonflammable paper according to claim 1, wherein the slurry further contains inorganic fibers as a reinforcing material.