JPH06158584A - Incombusible press board and its production - Google Patents

Abstract

PURPOSE:To produce an incombusible press board exhibiting a high ply bond strength and improved in water resistance by using sepiolite as the main material, paper-making a slurry containing an inorganic fiber, an organic filler, a binder and a thermosensitive resin, applying a predrying treatment thereto, laminating it and applying a heat treatment under pressure. CONSTITUTION:A slurry containing (A) sepiolite as the main material, (B) an inorganic fiber for reinforcement, (C) an organic filter, (D) a binder for aggregation and solidification and (E) a thermosetting resin (a thermosensitive resin) beginning to melt at a temperature beyond the predrying temperature is subjected to paper-making. The resultant wet sheet is predried, laminated and heated under pressure for insolubilization and infusibilization of the component (E).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noncombustible pressboard used for interior wall materials, building materials such as lining materials for partitioning panels, various heat insulating materials, and electrical insulators, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, flame resistance and flame retardancy have been demanded in many fields including building materials such as wall covering materials in response to social needs related to prevention of fire accidents. Conventionally, as a general-purpose non-flammable sheet material, one using asbestos fiber has been representative. Asbestos fiber sheet is flame retardant, heat resistant, high strength,
It excels in many aspects such as easy productivity and low price, and covers a range of applications where organic fibers are difficult, and has a wide range of uses.

However, recently, asbestos is in a situation where it cannot be used because it has a harmful effect on health. Therefore, development of alternative materials for asbestos is being carried out in various places. For example,
Japanese Patent Application No. 4-39910 discloses that the main material is adsorptivity,
Focusing on sepiolite, a mineral fiber with excellent thixotropy and caking properties, it has been difficult to make paper with a slurry containing a large amount of sepiolite fiber. A technique that enables the production of high-quality sheets is disclosed. This sepiolite-rich nonflammable sheet is expected to be used in a wide range of applications such as building materials due to its properties such as nonflammability and water resistance.

A thick non-combustible board of about several millimeters made by mixing a fiber material such as sepiolite fiber into a slurry is usually formed into a thick wet sheet by one-time papermaking, squeezed and heat-dried. Grind the uneven surface,
It is manufactured by making a flat surface.

[0005]

However, the conventional non-combustible board obtained by forming a thick wet sheet by one-time papermaking is pressed and heated and dried in a state where the wet sheet after the papermaking has a high water content. Therefore, in the case of a wet sheet having a thickness of several millimeters, it usually takes a long time of 30 to 40 minutes to apply pressure, and the press machine is expensive. Further, in the heating and drying, it takes a long time for the water content inside to be scattered, so that the production can be performed only at a speed of about several m ² per minute and the production efficiency is low.

Further, when a thick sheet is dried, a large warp occurs, which requires a separate step for correcting it, resulting in a high cost.

If the sheets have a laminated structure and the thin wet sheet is used for the papermaking, the papermaking becomes easy. However, in this case, since the interlayer strength is weakened, there is a problem that interlayer peeling easily occurs.

Therefore, the present invention has an object to provide a non-combustible pressboard which has a laminated thick plate structure containing sepiolite as an essential component, has a large interlayer strength, and can be manufactured at low cost in a short time, and a manufacturing method thereof. To do.

[0009]

The incombustible pressboard according to the invention of claim 1 comprises a sepiolite as a main material, an inorganic fiber for reinforcement, an organic extender, a binder for consolidation and agglomeration, and a preliminary. A slurry in which a heat-sensitive resin consisting of a thermosetting resin that starts to melt when heated above the drying temperature is made into a paper, is preliminarily dried, and then the preliminarily dried sheets are laminated, pressed and heated. Is.

The non-combustible pressboard according to the invention of claim 2 further comprises sepiolite as a main material, reinforcing inorganic fibers, an organic extender, a binder for consolidating and aggregating,
A slurry containing a thermosensitive resin made of a thermoplastic resin as an essential component is formed into paper, preliminarily dried, and then the preliminarily dried sheets are laminated, pressed and heated.

Further, in the method for producing a non-combustible pressboard according to the invention of claim 3, a raw material mixing step of mixing the essential components consisting of sepiolite, inorganic fibers, an organic extender and a heat-sensitive resin, and the raw material. A binder is added to the mixed liquid of the mixing step, an aggregating step of aggregating to form flocs, a papermaking step of forming a slurry in which flocs are formed in the aggregating step, and a wet sheet formed by papermaking are dried at a predetermined temperature, Preliminary drying step to make water content, laminating step to laminate predried sheets, pressurizing and heating step to press and heat the laminated laminated sheets to melt and solidify the thermosensitive resin inside to form a board And a cutting step of cutting the formed board into a predetermined size.

Here, reinforcing fibers such as glass fibers, rock wool, stainless fibers, and whiskers can be used as the inorganic fibers.

Further, wood pulp can be used as the organic extender, and various inexpensive waste materials such as wood fiber such as papermaking sludge and waste paper can also be used.

Examples of the heat sensitive resin include thermosetting resins such as epoxy resin, urea resin, phenol resin, melamine resin, unsaturated polyester resin and polyurethane, and polyethylene, vinyl chloride resin, polypropylene, polystyrene, ABS, polyethylene terephthalate and the like. A thermoplastic resin may be mentioned.

The binder can be satisfactorily manufactured by adding various known polymer flocculants for flocculation and consolidation, which are added individually or preferably in combination at a predetermined concentration.

Pressurization of the wet sheet after papermaking of the slurry,
Dehydration can be performed by a well-known cold press or hot press, and in the case of cold press, a smooth surface can be finished using a calender roll after pressing. In general, hot pressing is preferable because it can be dried at the same time as pressing and a calender roll can be eliminated.

[0017]

In the invention of claim 1, sepiolite and
Inorganic fibers, organic fillers, binders, and a heat-sensitive resin are mixed to form a slurry to form a wet sheet, and the wet sheet is pre-dried and then laminated to form a thick non-combustible board. Since it is formed, a thin wet sheet may be prepared in the papermaking. Therefore, papermaking of each wet sheet can be performed in a short time, and in preliminary drying, dehydration and drying can be performed up to a predetermined water content in a short time, and subsequent pressurization and heating can be performed in a short time.
Further, since the preliminary drying is carried out at a relatively low temperature, the heat-sensitive resin does not melt in the preliminary drying but melts in the subsequent pressure heating. Therefore, the bonding strength of each sheet itself is increased to improve the bending strength and water resistance, and the interlayer strength of the sheet is increased to prevent delamination, and the heat-sensitive resin solidified after pressure heating is Since it is a curable resin, it becomes insoluble and infusible, and the water resistance strength of the sheet is improved. Further, since the thin wet sheets are laminated to form a thick board, each sheet hardly causes warpage, and therefore, there is almost no warpage in the board after lamination. In addition, since sepiolite, which is excellent in adsorptivity, thixotropy, and caking properties, is an essential component and mainly inorganic substances, a board having high noncombustibility and high strength can be obtained. Moreover, since inexpensive materials are used, they can be manufactured at low cost.

Further, in the invention of claim 2, since the thermoplastic resin is used as the thermosensitive resin of claim 1, the sheet preliminarily dried by melting the thermoplastic resin in predrying. Has a high strength and is easy to handle.

Further, in the invention of claim 3, a raw material mixing step, an aggregating step, a papermaking step, a preliminary drying step,
Since a non-combustible pressboard can be manufactured by a simple process including a laminating process, a pressure heating process, and a cutting process, it is excellent in productivity and economical efficiency and can be used for mass production.

[0020]

EXAMPLES Examples of the present invention will be described below.

Table 1 shows the material composition of the non-combustible pressboard according to the embodiment of the present invention.

The unit of Table 1 is% by weight.

[0023]

[Table 1]

In Table 1 above, glass fibers are added to increase the bending strength. Also, wood pulp was mixed to give flexibility.

Further, a reinforcing resin such as an epoxy resin or an acrylic resin was added to strengthen the sheet, and a waterproofing agent such as wax was added to further enhance waterproofness.

Four types of binders were used in order to satisfactorily prepare a slurry containing sepiolite as an essential component.

As the first binder, PAA (polyacrylamide) having a molecular weight of 800,000 to 1,000,000, which is a thermoplastic resin, was used in order to increase the paper strength. The second binder uses EPA (polyamide polyamine epichlorohydrin), which is a thermosetting resin having a three-dimensional network structure, in order to impart cohesiveness and water resistance, and the third binder is an anionic thermoplastic resin. (Acrylamidoacrylic acid copolymer) as the coagulant, and the fourth binder is DM as the coagulant made of a cationic thermoplastic resin.
AEM (dimethylaminoethylmethacrylate) was used.

Next, a method for manufacturing the non-combustible pressboard of this embodiment using the materials having the above composition will be described with reference to FIG.

FIG. 1 is an explanatory view showing an outline of a manufacturing process of a non-combustible pressboard according to an embodiment of the present invention.

First, in the raw material mixing step A, sepiolite fibers and glass fibers were put into a defibrating machine such as a pulper and defibrated by stirring to improve the dispersion of the fibers. Further, the wood pulp was put into a beater such as a beater or a pocher and beaten.

Then, the defibrated sepiolite, the glass fiber, the beaten wood pulp, the phenol resin, the reinforcing resin and the waterproofing agent were put in a mixing tank and mixed.

Since the mixed liquid mixed in the raw material mixing step A is subjected to an aggregating treatment suitable for papermaking, a binder is added in the aggregating step B to prepare a slurry. Here, the binder is P as a first binder for increasing paper strength.
AA, EPA as a second binder for imparting cohesiveness and water resistance, AA as a third binder for aggregation
And DMAEM as a fourth binder for flocculation were added in this order. However, the order is not necessarily limited to this. The mixed solution to which the binder was added was focused by a focusing reaction device. The concentration of the slurry at this time was adjusted to about 0.5%. Subsequently, the concentrated slurry was sent to a stock tank and maintained so that the mixed state was always homogenized without causing sedimentation separation or collapse of the prepared paper stock. Then, the uniformly maintained slurry was pumped up to the quantitative hopper by the quantitative pump, and the slurry measured by the quantitative hopper was guided to the papermaking step C.

In the papermaking process C of this embodiment, a Fourdrinier wet machine was used. In this papermaking step C, the aqueous solution in which agglomerate flocs are formed is poured from above into a papermaking machine with a net, and water is quickly made to flow through the agglomerate flocs from the net, so that the water content is 60 to 70%. A wet sheet having a thickness of about 0.8 mm was obtained.

Next, the wet sheet is subjected to a preliminary drying step D.
And pre-dried. The preliminary drying was performed by open drying at a relatively low temperature of 30 to 70 ° C. for 30 minutes to 1 hour. By this preliminary drying, the moisture content of the wet sheet is 8 to
It decreased to 15%. At this time, since the wet sheet was thin, there was almost no warpage due to pre-drying, and because the drying efficiency was good, it was possible to dry to the above water content in a short time. At this stage, the phenol resin in the wet sheet does not melt because the drying temperature is low.

Next, in a laminating step E, several pre-dried sheets whose pre-drying reduced the water content to a predetermined value were laminated. Although sepiolite, phenolic resin, etc. can secure the interlayer bonding force of the completed sheet,
In order to prevent delamination more reliably, a thermoplastic resin such as an acrylic resin may be applied as an adhesive on the surface of the preliminary dry sheet before lamination.

The laminated sheet obtained by laminating several sheets in the laminating step E is
It sent to the pressure heating process F, and pressure and heating were simultaneously performed by the hot press. By this pressurization, the laminated sheet was dehydrated to be formed into a thick plate shape, and the internal moisture was evaporated by heating to dry and solidify. Here, the hot pressing was performed for 3 to 10 minutes under the conditions of a pressing force of 15 to 80 kg / cm ² and 130 to 180 ° C. Under this heating condition, since the phenol resin mixed inside melts, the binding force between the fibers increases and the interlayer strength improves. Since the phenol resin is a thermosetting resin, it is insoluble and infusible after being cooled and solidified. Since the wet sheet before lamination had almost no warpage because it was thin, and the surface was relatively smooth, the pressboard after pressurizing and heating had little warpage and had a smooth surface state. Therefore, after pressurizing and heating, in the case of a press board that was conventionally formed into a predetermined thickness without laminating and was heated under pressure, surface grinding of a calender roll or the like was required. The process can be eliminated.

Then, in a cutting step G, the compression-dried press board was cut into a predetermined size.

By the above, the plate thickness is about 3 mm and the bulk specific gravity is about 0.
A non-combustible press board of 9 g / cm ³ was completed.

In each of the examples, a nonflammable pressboard having a good appearance and nonflammability, excellent bending resistance and water resistance, and high interlaminar strength was obtained. The phenol resin solidified after heating under pressure becomes insoluble and infusible, and is particularly excellent in water resistance against hot water and hot water. Regarding incombustibility, organic materials are also included in the material, but inorganic materials are the main constituents, and since it is a thick plate laminated to block the passage of air to the inside, The standard was cleared.

As described above, the non-combustible pressboards of the above-described examples include sepiolite as a main material, glass fiber as an inorganic fiber for reinforcement, and wood pulp as an organic extender.
After making a slurry of the essential components of a binder consisting of four types of polymer compounds for consolidation and aggregation and a phenol resin as a heat-sensitive resin that starts melting when heated above the preliminary drying temperature, and after preliminary drying The pre-dried sheets are laminated, pressed and heated.

Therefore, according to the above-mentioned embodiment, a wet sheet is formed by making a slurry by mixing sepiolite, glass fiber, wood pulp, a binder and a phenol resin, and the wet sheet is preliminarily prepared. After drying
By forming a thick board by stacking,
A thin wet sheet may be prepared for papermaking. Therefore, each wet sheet can be easily produced in a short period of time, and can be produced at a speed of about 30 m ² / min, which was conventionally a few m ² / min. Then, even in the preliminary drying, the dehydration and drying can be performed to a predetermined water content in a short time, and the subsequent pressurization and heating can be performed in a short time. In addition, it can be wound and stored.

Further, since the preliminary drying is carried out at a relatively low temperature, the heat-sensitive resin does not melt in the preliminary drying but melts in the pressure heating afterwards. Therefore, in particular, the effect of phenol resin melting appears in the interlayer adhesion of the sheets, not only the bonding strength of each sheet itself, but also the interlayer strength of the sheet is increased, delamination is less likely to occur, and the bending strength is excellent. Will be things. And
After melting and solidification, the phenol resin becomes insoluble and infusible.
Excellent water resistance. In addition, since it contains a waterproofing agent,
The water resistance can be further improved, and water can be prevented from adhering and swelling during use.

Further, since a thin wet sheet is laminated to form a thick board, warpage hardly occurs in forming each sheet, and therefore warpage in the board after lamination can be avoided.

In addition, since sepiolite, which is excellent in adsorptivity, thixotropy, and solidification, is an essential component and mainly inorganic substances, a board having high incombustibility, high strength, and high rigidity can be obtained. Therefore, the required rigidity can be secured even if the conventional plate thickness of about 6 mm is changed to about 3 mm. And the conventional 1.6
Since the bulk specific gravity, which has been around to a certain extent, is reduced to about 0.9, the overall weight can be greatly reduced, the transportation work and the handling work can be facilitated, and the burden on the operator can be reduced.

Since inexpensive materials are used,
It can be manufactured at low cost.

In addition, in the method for producing a non-combustible pressboard of the above embodiment, the raw material mixing step A of mixing the essential components consisting of sepiolite, glass fiber, wood pulp, and phenol resin, and the raw material mixing step A Aggregation step B in which a binder is added to the mixed liquid and aggregated to form flocs
And a papermaking step C for making a slurry with flocs formed in the agglomeration step B, a pre-drying step D for drying the wet sheet made at a predetermined temperature to a predetermined water content, and a few pre-dried sheets. Laminating step E for laminating and laminating laminated sheets are pressurized and heated to melt the phenol resin inside,
Pressurizing and heating step F for solidifying to form a press board, and cutting step G for cutting the formed press board into a predetermined size.
Consists of.

Therefore, according to the above embodiment, the raw material mixing step A, the aggregating step B, the papermaking step C, the preliminary drying step D, the laminating step E, the pressure heating step F, and the cutting step G.
Since a non-combustible pressboard can be manufactured by a simple process consisting of, it is excellent in productivity and economic efficiency and can be used for mass production.

The above embodiments correspond to the modes of claims 1 and 3.

By the way, in the above embodiment, a phenol resin which is a thermosetting resin is used as the heat sensitive resin, but a thermoplastic resin may be used when the present invention is carried out. In this case, the pre-drying temperature is 80-150 ° C.
And the temperature in pressure heating after lamination is 100 to 150.
The board can be formed at 0 ° C.

When the thermoplastic resin is used, it is melted and solidified particularly in the preliminary drying, the strength of the preliminary dried sheet is improved, and the handling becomes easy.

This case corresponds to the modes of claims 2 and 3.

The non-combustible pressboard is used as an interior wall material by attaching a decorative plate to the surface, a building material as a lining material for a partition panel, and various heat insulating materials.

[0053]

As described above, the incombustible pressboard according to the first aspect of the present invention comprises sepiolite, inorganic fibers, an organic extender, a binder, and a thermosensitive resin composed of a thermosetting resin as essential components. The prepared slurry is made into paper, preliminarily dried, and then the preliminarily dried sheets are laminated, pressed and heated. Therefore, since a thick noncombustible board is formed by laminating the slurry to form a wet sheet, predrying the wet sheet, and laminating the wet sheet, a thin wet sheet may be formed in the papermaking. As a result,
Paper making of each wet sheet can be facilitated and can be performed in a short time, and pressurization and heating can be performed in a short time. Also,
Almost no warpage occurs in the formation of each wet sheet, and warpage in the board after lamination can be avoided. Furthermore, the heat-sensitive resin that melts under pressure and pressure increases the interlayer strength of the sheet, and can prevent delamination. Then, the heat-sensitive resin solidified after heating under pressure becomes insoluble and infusible, so that the water resistance strength is improved. In addition, since inexpensive materials are used, they can be manufactured at low cost.

A non-combustible pressboard according to a second aspect of the present invention is a heat-sensitive resin composed of sepiolite as a main material, inorganic fiber for reinforcement, organic extender, binder for consolidation and aggregation, and thermoplastic resin. A slurry in which and are essential components is formed into paper, preliminarily dried, and then preliminarily dried sheets are laminated, pressed and heated. Therefore, in particular, the strength of the pre-dried sheet is increased by melting the heat-sensitive resin made of a thermoplastic resin in the pre-drying,
It can be handled easily.

The method for producing a non-combustible pressboard according to the third aspect of the present invention comprises sepiolite, inorganic fibers, an organic extender, and
A raw material mixing step of mixing essential components consisting of a thermosensitive resin, and a binder added to the mixed liquid of the raw material mixing step,
An aggregating step of forming flocs by aggregating, a paper making step of making a slurry in which flocs are formed in the agglomerating step, a wet drying sheet made at a predetermined temperature and a pre-drying step of making a predetermined water content, and a pre-drying step. Laminating step of laminating the laminated sheet, pressurizing and heating the laminated laminated sheet to melt and solidify the thermosensitive resin inside to form a board, and cut the formed board into a predetermined size. And a cutting process. Therefore, since the non-combustible pressboard can be manufactured by these simple steps, it is excellent in productivity and economical efficiency and can be mass-produced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of a manufacturing process of a non-combustible pressboard according to an embodiment of the present invention.

[Explanation of symbols]

 A raw material mixing step B aggregating step C papermaking step D pre-drying step E laminating step F pressure heating step G cutting step

Claims (3)

[Claims] 1. A sepiolite as a main material, an inorganic fiber for reinforcement, an organic extender, a binder for consolidating and aggregating, and a thermosetting resin which starts melting upon heating above a predrying temperature. A non-combustible material characterized in that a slurry containing a heat-sensitive resin as an essential component is made into paper, preliminarily dried, and then the preliminarily dried sheets are laminated and pressed and heated to make the heat-sensitive resin insoluble and infusible. Press board. 2. Papermaking of a slurry containing sepiolite as a main material, inorganic fibers for reinforcement, an organic extender, a binder for consolidation and aggregation, and a heat-sensitive resin made of a thermoplastic resin as essential components. Then, after pre-drying, the pre-dried sheets are laminated, pressed and heated to produce a non-combustible press board. 3. A raw material mixing step of mixing the essential components consisting of sepiolite as a main material, reinforcing inorganic fibers, an organic extender, and a heat-sensitive resin, and solidified in a mixed liquid of the raw material mixing step. , A flocculation step of adding a binder for flocculation and flocculating to form flocs, a papermaking step of papermaking a slurry in which flocs are formed in the flocculation step, and a wet sheet made of paper is dried at a predetermined temperature to have a predetermined water content. A pre-drying step, a laminating step of laminating the pre-dried sheets, a pressure heating step of pressing and heating the laminated laminated sheets to melt and solidify the thermosensitive resin inside to form a board, And a cutting step for cutting the formed board into a predetermined size.