JPH05163696A - Incombustible sheet and its production - Google Patents

Abstract

PURPOSE:To give incombustibility and water resistance by using sepiolite as the main raw material and to enable paper-making at a low cost by mass- production while improving productivity. CONSTITUTION:Sepiolite is used as the main raw material and a polymer coagulant obtained by mixing DMAEM as a strongly cationic polymer and AA as a weakly anionic polymer in an amount of 0.2 to 1.0wt.% in total based on the raw material solid matter is added thereto. The resultant slurry is subjected to paper-making, thus producing the objective sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noncombustible sheet used for wall coverings, heat-resistant decorative sheet, etc., and a method for producing the same, and particularly has noncombustibility and heat resistance as an asbestos substitute, and The present invention relates to a non-combustible sheet having excellent productivity and a method for manufacturing the same.

[0002]

[Prior Art]

[0003]

In recent years, due to social needs related to prevention of fire accidents, problems such as flameproofing and fireproofing have been taken up in building interior materials as well as plastics and clothing, and they have been severely regulated. It became so. Paper is no exception to this, and there are many market demands for so-called flameproof / nonflammable paper (nonflammable sheet), including wall coverings, that do not burn and are resistant to heat.

Conventionally, as general-purpose non-burnable paper, asbestos fiber paper is representative of inorganic fibers. This asbestos fiber paper excels in all aspects such as flame retardancy, heat resistance, high strength, easy productivity, and low price, and covers areas of application difficult with organic fibers.
It had a wide range of uses.

However, recently, asbestos has a harmful effect on health, so that it has gradually become unusable in Japan. In Western Europe, it is almost unusable. From this situation, with the development of new materials, the development of alternative materials similar to asbestos is being actively researched in various places, and high-performance inorganic fibers or 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, phosphoric acid 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.

[0006] In addition, there is a flameproofing method as a method for producing 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 a wood pulp paper such as kraft paper impregnated with or coated with a flameproofing agent. Ammonium-containing salt type aqueous inorganic salts, phosphorus-containing nitrogen compounds, phosphorus-containing halogen compounds, antimony trioxide-
A halogen compound, a boron compound, a halogen compound, etc. are used. However, this treatment is mainly organic matter after all and cannot be said to be completely nonflammable. Aromatic polyamide fibers are also used as high-performance fibers, but they are not widely used.

Under these circumstances, there is 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.

[0008] 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 non-combustible sheets that use sepiolite.

Sepiolite is a clay mineral commonly referred to as mountain leather, mountain cork, and mountain wood, and sepiolite in Japan is one of these. Generally, it is a mass of magnesium silicate having fibrous properties, and is rich in adsorptivity, thixotropy and solidification.

Examples of papermaking using this characteristic include, for example, Japanese Patent Laid-Open Nos. 51-88799 and 56-1.
65097, JP-A-58-95636, JP-A-58-144196, JP-A-59-2180.
No. 0, JP 61-258099 A, JP 6
There are techniques disclosed in JP-A-3-235600, JP-A-64-61599 and the like.

[0011]

In the above publication, sepiolite, which is rich in adsorptivity, thixotropy and solidification, is used as an auxiliary for inorganic fibers such as ceramic fibers and cloth, that is, fibers composed of organic fibers or both. In many cases, they are mixed, dispersed, processed, and dried. This is because when sepiolite is a fine fiber, when it is made into paper, its drainage is poor, and the ratio of raw material to raw material added in a slurry composed of general good drainage wood pulp, synthetic fiber, inorganic fiber, etc. 0.01
With the addition amount of coagulant of ~ 0.1%, it is difficult to form an arbitrary sheet, and because the tear strength is poor, it must withstand mechanical impacts such as pump-up, stirring, and turbulent flow in the paper manufacturing process. This is because it is difficult to make paper from sepiolite as the main raw material due to factors such as the inability to produce paper. Even if the amount of the aggregating agent added is 0.1% or more with respect to the raw material, not only the drainage performance is not improved, but also the excessive addition increases the viscosity of the slurry and rather deteriorates the papermaking property. For this reason, in the past, even if it was possible in the case of small-scale production in a laboratory, it was extremely difficult to carry out industrial production in conformity with the mass production base, and the excellent characteristics of sepiolite were not fully utilized. Slightly, JP-A-59-21800
In the gazette, there is a description about the use of sepiolite fiber alone, but there is no description about the specific technical contents, and it is not practical.

By the way, as described above, wall paper is required to have flameproofness and nonflammability in terms of disaster prevention. On the other hand, a building material, in a humid country such as Japan, absorbs water and swells, and there is a risk that the wall-paper will be deformed or broken by repeated swelling and drying. Therefore, in addition to flameproofness and nonflammability, water resistance is also required.

However, in the above publication, there is almost no description of a technique relating to water resistance. Slightly the above-mentioned JP-A-59
In Japanese Patent Laid-Open No. 21800, there is described a technique for improving 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, but the application is a filter paper, and However, the specific technical content is not clearly stated, and there is a possibility that the practicality is lacking as described above.

Therefore, the present invention provides a low-cost non-combustible sheet which has both non-combustibility and water resistance by using sepiolite as a main raw material, and has improved productivity and can be manufactured by mass production. The challenge is to provide.

[0015]

A non-combustible sheet according to the present invention comprises a sepiolite as a main material and a strong cationic polymer and a strong anionic polymer in a total amount of 0.2 to 1.0% by weight based on a solid content of raw materials. % Of the polymer coagulant mixed, the slurry containing the essential component is made into paper.

Further, in the method for producing a non-combustible sheet according to the present invention, sepiolite as a main material, and a strong cationic polymer and a strong anionic polymer are added in a total amount of 0.2 to 1.0% by weight based on the solid content of the raw material. A slurry is prepared by using a mixed polymer flocculant as an essential component.

[0017]

In the present invention, since the flocculant is a mixture of a strong cationic polymer and a strong anionic polymer, it forms an ion complex with the slurry for forming the sepiolite main material and is insolubilized to reduce the adhered water. However, since the hydrophilicity is reduced, the flocs are tightened. As a result, a strong, high-yield floc that can withstand mechanical shock in the papermaking process is formed, and papermaking properties are improved, which is consistent with productivity and economy. Mass production of seats becomes possible. When the total amount of the strong cationic polymer and the strong anionic polymer added is 0.2% by weight or less in the raw material, the combined effect is small. Since the viscosity increases and papermaking becomes difficult, the mass-producible range is 0.2 to 1.0% by weight.

Since the main material of the non-combustible sheet produced as described above is inexpensive sepiolite, it has non-combustibility and water resistance and can be manufactured at low cost.

[0019]

EXAMPLE An example of the present invention will be described below.

First, the raw material composition of this embodiment is shown.

[0021]

[Table 1]

In the table, DMAEM is dimethylaminoethyl methacrylate (same below), AA is acrylamidoacrylic acid copolymer (same below), which are used in this example as strong cationic polymer and strong anionic polymer, respectively. Is.

These aggregating agents are a feature of the present invention, and are liquid high-molecular polymers, and their compounding ratios are all polymer pure contents, that is, solid content weight ratios.

In general, there is no strict definition of "strong cationic polymer" or "strong anionic polymer", but in the present invention, "strong cationic polymer" means that the cation is 3.5 meq / g or more. Say something, and also
The “strong anionic polymer” means that the type of anionic polymer flocculant is limited, so the ionicity is judged from general applications, and the ratio of dissociation into anions in water is 20.
% Or more, that is, the ratio of not dissociated is 80% or less.

The compounding ratio of these flocculants will be described later.

In this example, water was added to the raw material having the above mixing ratio to dilute it to 0.5 to 1.0%, and this was used as the papermaking concentration.

Next, production of a nonflammable sheet having the above composition will be described.

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

In the drawing, in the defibration step A, sepiolite as a main raw material, glass fiber as a reinforcing material, wood pulp as a reinforcing fiber and synthetic fiber are put into a defibrating machine and defibrated by stirring to disperse the fibers. Improve In this example, if the amount of wood pulp is 5% by weight or more, nonflammability will be impaired, so the amount is limited to 5% by weight or less.

Next, in the raw material mixing step B, the disentangled paper material, softening agent, stabilizer and the like are put into a mixing tank and mixed to prepare a slurry.

The slurry mixed in the raw material mixing step B is
In order to carry out a coagulation treatment suitable for papermaking, in a process step C, a focusing reaction device is used to perform focusing. As shown in the above table, the coagulant used here is a combination of a strong cationic polymer and a strong anionic polymer.

Next, the slurry prepared in the processing step C is sent to a stock tank, and a storage step D is carried out in which the mixed state is always kept uniform so as to prevent sedimentation separation or collapse of the prepared sheet. enter.

Then, the slurry uniformly maintained in the accumulating step D is pumped up to the metering hopper by a metering pump,
Lead to the papermaking process E.

In the papermaking process E of this embodiment, papermaking was carried out using a short-net paper machine. The slurry concentration at this time is 0.5 to
1.0%, and the short-net paper machine used a 60-80 mesh net. In this papermaking step E, when the dispersed aqueous solution in which agglomerated flocs are formed is flown into a papermaking machine having a mesh of about 80 mesh from above, water quickly flows down from the mesh through the flocs to form a paper layer.

Thereafter, in the drying step F, the paper layer is pressed and dehydrated and dried at an ambient temperature of about 120 ° C. for a predetermined time, whereby the water content in the paper layer is evaporated and the binder is condensed. Is accelerated to dry and solidify.

As described above, a nonflammable sheet having a plate thickness of 0.1 to 1.0 mm is completed. This non-combustible sheet has high heat resistance, and even if a fire is approached, it can maintain a predetermined shape with only a slight smoke and blackening.

Next, the coagulant, which is a feature of this embodiment, will be described.

Generally, when the main raw material is wood pulp, synthetic fiber, inorganic fiber or the like having a good drainage property, the coagulant having a solid content of 0.01 to 0.1% by weight relative to the raw material is added to produce electricity. The paper is fixed, the flocs are formed, and it is possible to mass-produce paper.

However, when the main raw material is sepiolite, as described above, the drainage is poor and the tear strength is weak, so that it is possible to withstand mechanical impacts such as pump-up, stirring and turbulent flow in the papermaking process. Therefore, conventionally, mass production has been difficult.

In the present invention, a strong cationic polymer and a strong anionic polymer are used and a predetermined mixing ratio is used to form an ion complex with the slurry for forming the sepiolite main material, which is insolubilized. A network was formed, and as a result, papermaking at a mass production level became possible.

The details will be described below based on the experimental data shown in FIGS.

FIG. 2 is a graph showing the relationship between the amount of coagulant added and freeness in one embodiment of the present invention, and FIG. 3 is the relationship between the amount of coagulant added and turbidity in one embodiment of the present invention. FIG. 4 is a characteristic diagram showing the relationship between the combined use ratio of the agglomerated polymer and the freeness in one example of the present invention.

FIG. 2 shows the freeness which is an index of productivity when the amount of addition of various coagulants is changed. The freeness is a cylindrical container in which a wire mesh of 80 mesh is set. It was evaluated by injecting 1000 cc of the diluted stock material and measuring the filtration amount of the slurry for 30 seconds.

In the figure, the thin solid line indicates the nonionic polymer, the "strong", "medium", and "weak" cations.
This is a representative example of the case where each coagulant such as “strong”, “medium” and “weak” anions is used “alone”, and each of the coagulants is represented by a thin solid line represented by a characteristic diagram. I drew a curve close to.

On the other hand, when a cation and an anion of a high molecular polymer are used in combination, "weak cation + weak anion"
In the combination of, the curve indicated by a broken line similar to that of the "alone" was drawn, and in the combination of "medium cation + middle anion", the freeness was slightly larger than these. But,
It is difficult to industrially produce this "medium cation + medium anion" with freeness. In addition, in these combinations, the numerical value of the addition amount indicates the addition amount of both the cation and the anion (the same applies below).

On the other hand, in the case of "strong cation + strong anion", the freeness is about 4 times that of "medium cation + medium anion" at the peak, and a value of this level is sufficient. It is at a level where mass production is possible. From the curve in the figure,
If it is about 2% by weight or more, industrial production is considered possible.
However, if it exceeds 1.0% by weight, the viscosity of the slurry becomes very large, which makes papermaking difficult. Therefore, 0.2 ~
It is determined that 1.0% by weight is the amount that can be mass-produced.

On the other hand, the turbidity after filtration, which is an index of paper-making property and is consistent with the freeness, was also examined. Turbidity was measured by using a scattered light (reflection) photoelectric turbidimeter on the filtered slurry.

In FIG. 3, when the freeness is large, the filterability of the papermaking machine is good, and the turbidity of the slurry after filtration naturally shows a low value. As is clear from this figure, in the case of "strong cation + strong anion" as compared to the case of "single" polymer, "weak cation + weak anion", and "medium cation + medium anion" as in FIG. It can be seen that indicates a very low value.

Thus, "strong cation + strong anion"
The papermaking property of the combination of is because the strong cationic polymer and the strong anionic polymer form an ion complex with the forming slurry of the sepiolite main material, and are insolubilized to reduce the adhered water, thereby decreasing the hydrophilicity. It is thought that the floc is tightened. In addition, "weak cation +
This is probably because the combined effect of "weak anions" and "medium cations + middle anions" has not been sufficiently exhibited.

Next, the combined ratio of the strong cationic polymer and the strong anionic polymer in the case of "strong cation + strong anion" will be described.

FIG. 4 shows the combined use ratio of each polymer in the flocculant in which the strong cationic polymer and the strong anionic polymer are used together, and the total addition amount of “strong cation + strong anion” is 0.3% by weight. , 0.5% by weight, when the combined ratio of the strong cationic polymer and the strong anionic polymer is about 50%, that is, when the molar ratio of the strong cationic polymer and the strong anionic polymer is about 1: 1. In addition, the production rate of the ion complex and the freeness associated therewith were the maximum. This is presumably because the strong cationic polymer and the strong anionic polymer theoretically react with each other in an equimolar manner. From the figure, it is judged that mass production is possible if the mixing molar ratio of the strong cationic polymer is within the range of about 25 to 75%.

As described above, the non-combustible sheets of the above-mentioned examples are mainly composed of sepiolite, and the strong cationic polymer DMAEM and the strong anionic polymer AA are added in a total amount of 0.2 to 1 with respect to the solid content of the raw material. It is manufactured by making a slurry into which a polymer flocculant mixed with 0.0% by weight is added.

Therefore, according to the above-mentioned embodiment, since the coagulant is a combination of the strong cationic polymer and the strong anionic polymer, it forms an ion complex with the slurry for forming the sepiolite main material and insolubilizes it. The adhered water decreases, the hydrophilicity decreases, and the flocs are tightened. As a result, strong, high-yield flocs that can withstand mechanical impacts such as pump-up, stirring, and turbulent flow are formed, and papermaking properties are improved, which is consistent with productivity and economic efficiency.
It is possible to mass-produce non-combustible sheets that use sepiolite as a main raw material.

In this case, if the total amount of the strong cationic polymer and the strong anionic polymer added is 0.2% by weight or less in the raw material, the combined effect is small,
When it is 1.0% by weight or more, the viscosity of the stock water becomes large and it becomes difficult to make a paper. Therefore, the total amount added is 0.2 to 1.0% by weight to achieve the above-mentioned high yield of flocs. it can.

Further, since the molar ratio of the cationic polymer in the polymer flocculant in which the strong cationic polymer and the strong anionic polymer are used in combination is set to 25 to 75%, the production rate of the ion complex is increased and the freeness is increased. It is possible to increase the particle size and to achieve a high yield of flocs in the same manner as described above.

Since the main material of the non-combustible sheet produced as described above is inexpensive sepiolite, it has noncombustibility and water resistance and can be manufactured at low cost.

By the way, the aggregating agent of the above-mentioned examples uses a strong cationic polymer and a strong anionic polymer in combination. However, the present invention is not limited to this, and sepiolite itself. Since it has a cationic property, depending on the implementation conditions, it may be possible to mass-produce paper even if the coagulant to be added is only a strong anionic polymer. This case corresponds to the aspects of claims 3 and 6.

Although the non-combustible sheet of the above-mentioned embodiment is mixed with glass fiber as a reinforcing material, the present invention is not limited to this, and rock wool fiber, stainless fiber is not limited to this. It is possible to use various reinforcing materials such as whiskers. However, glass fiber is most suitable in terms of material cost, cohesive effect, and the like. Depending on the intended use, it is not always necessary to mix the reinforcing material. In this embodiment of the invention, the step of mixing the reinforcing material can be omitted and the work can be simplified. In addition, it is possible to give a smooth texture to a non-combustible sheet that is hard by mixing glass fibers. Similarly, it is not always necessary to mix wood pulp and synthetic fibers as reinforcing fibers,
It may be appropriately used in consideration of paper-making properties, intended use, and the like.

Further, the strong cationic polymer and the strong anionic polymer of the above-mentioned examples are DMAEM and AA, respectively.
However, when the present invention is carried out, the present invention is not limited to this, and a strong cationic polymer and a strong anionic polymer that can be used as a flocculant can be appropriately selected.

Further, the combined ratio of the respective components in the above-mentioned examples is not limited to the values in the above-mentioned table, and an optimum one may be selected according to the physical properties, drainage, application and the like.

The non-combustible sheet of the present invention is a wall covering material,
It can be used as a sealing material, architectural surface paper, etc., but it can also be used by preventing it from sticking or falling off by sticking it on both sides of the heat insulating material. .. Alternatively, they can be laminated to form a heat insulating material and can also be used as an insulating material.

Further, it is possible to make it thick and use it as a non-combustible board, for example, and to fabricate it in a concavo-convex shape, so that it can also be used as a three-dimensionally shaped non-combustible material.

[0063]

INDUSTRIAL APPLICABILITY As described above, the nonflammable sheet and the method for producing the same of the present invention are mainly composed of sepiolite, and the total amount of the strong cationic polymer and the strong anionic polymer is 0.2 to 1 with respect to the solid content of the raw material. It is made by making a slurry into which a polymer flocculant mixed with 0.0% by weight is added,
The method for producing a non-combustible sheet of the present invention comprises a polymer flocculant containing sepiolite as a main material and a strong cationic polymer and a strong anionic polymer mixed in a total amount of 0.2 to 1.0% by weight with respect to the raw material solid content. The added slurry is made into paper. Therefore, the aggregating agent formed by using the strong cationic polymer and the strong anionic polymer in combination forms an ion complex with the forming slurry of the sepiolite main material,
Since it becomes insoluble and reduces the amount of adhered water, and reduces the hydrophilicity,
The production floc is tightened. As a result, a strong floc that can withstand mechanical impact is formed, and a high yield of flocs is formed to improve the papermaking property, which is consistent with productivity and economy.
It is possible to mass-produce non-combustible sheets using sepiolite as the main raw material. Since the main material of the non-combustible sheet produced as described above is inexpensive sepiolite, it has non-combustibility and water resistance and can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of a manufacturing process in a nonflammable sheet and a manufacturing method thereof according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the amount of coagulant added and the freeness in the non-combustible sheet and the method for producing the same according to one embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the amount of coagulant added and the turbidity in the nonflammable sheet and the method for producing the same according to one embodiment of the present invention.

FIG. 4 is a characteristic diagram showing the relationship between the combined use ratio of the agglomerated polymer and the freeness in the nonflammable sheet and the method for producing the same according to one embodiment of the present invention.

[Explanation of symbols]

 A defibration process B raw material mixing process C treatment process D accumulation process E papermaking process F drying process

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location D21H 17/37 // C08J 5/18 9267-4F

Claims (6)

[Claims] 1. A slurry comprising, as essential components, sepiolite as a main material and a polymer flocculant in which a strong cationic polymer and a strong anionic polymer are mixed in a total amount of 0.2 to 1.0% by weight in a solid content of a raw material. A non-combustible sheet characterized by being manufactured by papermaking. 2. The combination ratio of the strong cationic polymer in the polymer flocculant in which the strong cationic polymer and the strong anionic polymer are used in combination is 25 to 75%. Non-combustible sheet. 3. Sepiolite as a main material and a strong anionic polymer in a raw material in a solid content of 0.1 to 0.5% by weight.
A non-combustible sheet, which is formed by making a slurry containing a mixed polymer flocculant as an essential component. 4. A slurry containing, as essential components, sepiolite as a main material and a polymer flocculant in which a strong cationic polymer and a strong anionic polymer are mixed in a total amount of 0.2 to 1.0% by weight in a solid content of raw materials. A method for producing a non-combustible sheet, comprising: 5. The combination ratio of the strong cationic polymer in the polymer flocculant in which the strong cationic polymer and the strong anionic polymer are used in combination is 25 to 75%. Manufacturing method of non-combustible sheet. 6. Sepiolite as a main material and a strong anionic polymer in a raw material in a solid content of 0.1 to 0.5% by weight.
A method for producing a non-combustible sheet, which comprises forming a slurry containing a mixed polymer flocculant as an essential component.