JP2686554B2 - Continuous sheet manufacturing method and continuous sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the invention]

TECHNICAL FIELD The present invention relates to a method for continuously producing a sheet containing a vegetable or inorganic excipient and a continuous sheet thereof. [Prior Art] Conventionally, in order to mix a solid organic material or an inorganic material with a resin adhesive, a method of stirring and mixing with a hand mill, a kneader, a roll mixer, or the like has been used. For example, when the curing speed is slow and the adhesive force of the prepolymer or the produced resin is weak such as 50 g or less, the raw materials are mixed by a known means, spread on a belt conveyor, and then pressed by a roll to obtain a uniform coating. It is possible to obtain a continuous sheet having a thickness and a uniform width. However, the urethane prepolymer or its resin, which is a typical quick-hardening resin, when used as a certain composition,
It has a particularly strong adhesiveness, for example, in the production of particle board, when urethane resin is used as a binder and the mixture with wood chips is hot pressed, the resin adheres to the hot plate and ordinary urea / melamine resin is used as a binder. It is difficult to manufacture with such a particle board manufacturing means. Therefore, in a known method such as head mixing or spray mixing, a resin having a high curing rate or a resin having a strong adhesive force, such as a urethane resin or an acrylic resin, which is the object of the present invention, and a vegetable fiber or an inorganic fine fiber are uniformly mixed. Not available when mixed in. Further, even if it is possible to overcome the problem of adhesion, for example, for flooring materials that use sheets, wall materials, and other products, dimensional accuracy such as thickness is required,
It is difficult to spread the mixture uniformly on a wide substrate and shape it into a uniform layer. For example, if pressure is applied from the top for the purpose of making the thickness uniform, it will not be possible to release from the press plate due to its adhesiveness, and even if a release sheet such as a release bite or Teflon is used, its adhesiveness Can't be stopped. [Problems to be solved by the invention] Therefore, the problem to be solved by the present invention is to use a curable resin having a high curing rate or a high tackiness as a binder, and bonding a vegetable or inorganic excipient to obtain a uniform composition. It is to develop a means for continuously producing a wide sheet of various sizes.

Configuration of the Invention

[Means for Solving the Problems] (1) Outline In order to solve the above problems, the present invention is an epoch-making method, that is, an uncured and curing speed is continuously supplied on a belt conveyor. Prepolymer solution (A) which is fast or exhibits tackiness in the curing process after supply (A)
It is characterized in that at least one kind of excipient (B) selected from the group consisting of vegetable fine fiber, vegetable powder, inorganic fine fiber and inorganic powder is continuously and uniformly dropped on the above. Hereinafter, important matters related to the configuration of the present invention will be described separately. (2) Prepolymer solution In the present invention, "uncured and fast curing prepolymer" means a prepolymer that starts to cure within a predetermined temperature within 30 minutes, particularly within 10 minutes, and "after supply""A prepolymer that exhibits tackiness during the curing process" means a tack tester manufactured by Toyo Seiki Co., Ltd., adhesion time 20 seconds, rising speed 25 mm /
Min, product temperature 20 ° C, relative humidity 60% means that it has an adhesive force of 50g or more under the condition of 50%, even if the initial prepolymer solution has a low adhesive property
It is applied in the above cases. The prepolymer solution that satisfies one of these conditions is
Examples thereof include an aqueous solution of an unsaturated monomer compound, a urethane compound, a phenol compound or the like, or an organic solvent solution. Examples of such unsaturated monomer compounds include polymethacrylate of polyoxyalkylene polyol, copolymers of α-olefin such as isobutene and a monomer having a carboxyl group such as maleic anhydride, sodium acrylate, Acrylic acid amide, methacrylic acid derivative such as methylene-bis-acrylamide, vinyl alcohol, vinyl sulfonic acid, vinyl acetate, allylamine, a solution containing at least one unsaturated monomer compound such as maleic anhydride, in this case, If necessary, a polymerization catalyst or a crosslinking agent is used in combination. In addition, natural rubber, styrene-butadiene rubber (SB
R), chloroprene rubber, polyvinyl acetate, polyvinyl chloride, ethylene / vinyl acetate copolymer (EVA), polymethacrylic acid ester, etc. made into an aqueous dispersion having gel forming ability by using various surfactants. Can also be mentioned. These unsaturated monomer-based compounds neutralize the surface charge by heating them or adding various ionic surfactants that neutralize the surface charge of the emulsion particles and organic acids, organic acid salts and inorganic acid salts. Resinization or gelation is carried out by salting out or salting out. UV rays, electron beams,
It can also be made into a resin by irradiation with microwaves or far infrared rays. Next, as the urethane-based compound, there is a terminal NCO-group-containing prepolymer obtained by the reaction of monool or polyol with an organic polyisocyanate. Monool here means methanol, ethanol,
It refers to a compound obtained by addition-polymerizing ethylene oxide or other alkylene oxides alone or in combination with a monohydroxyl group-containing compound such as butanol, hexanol, octanol, phenol, cresol, or alkylphenol. Examples of polyols include polyoxyalkylene polyols such as polyoxyethylene glycol, polyester polyols, polycaprolactone polyols, dimer acid ester polyols, polycarbonate polyols, butadiene polyols, acrylic polyols, hydrolysates of ethylene / vinyl acetate copolymers, and chloroprene. Examples include polyols. Examples of the organic polyisocyanate to be reacted with monool or polyol include tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MD
I), polymethylene polyphenyl isocyanate (CM
DI) Hexamethylene diisocyanate, xylene diisocyanate (XDI), isophorone diisocyanate, hydrogenated XDI or hydrogenated MDI can be mentioned. In some cases, a curing accelerating catalyst such as amine or metal soap and various resin latices are used in combination with these urethane prepolymers. Next, examples of the phenol compound include a resole obtained by condensation of phenol and formaldehyde, and a condensate of resorcinol and formaldehyde, and in some cases, a catalyst is used in combination. The prepolymer solution is often used in combination with a catalyst or a cross-linking agent in practice, and is therefore a two-component reaction type, so that it is mixed immediately before use. (3) Excipient In the present invention, vegetable fine fibers or powder particles thereof, inorganic fine fibers, and inorganic powder are used as excipients. Examples of the vegetable fine fiber or its grain include wood flour,
Wood scraps, rice husks, husk charcoal, barley husks, buckwheat husks, rice bran, rice bran, soybean meal, fiber scraps, cotton litters, etc. can be shown, but are not limited to the examples. As the inorganic fine fibers and the inorganic powder, for example, activated carbon, carbon fiber, metal fiber, boron fiber, ceramic fiber, carbon powder, charcoal powder, graphite powder, coal powder,
Coke powder, silica, perlite, asbestos, diatomaceous earth, shirasu balloon, pearlite foam, pumice, verculite, attapulgite, glass balloon, activated clay,
Calcium carbonate, talc, kaolin, calcium silicate,
Fine fibers and powders of zeolite, mica, aluminum hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide, magnesium silicate, ceramics, silicic acid, borosilicate, borax, silicon nitride, silicon carbide and the like can be mentioned. These may be used alone or in combination of two or more. (4) Amount of Prepolymer Solution Used The amount of the prepolymer solution used in the present invention is
1 to 5 in terms of solid content for 100 parts (weight part, the same applies below)
The amount is 00 parts, more preferably 3 to 100 parts. The amount of water or organic solvent used at the same time is preferably 10 parts or more with respect to 100 parts of the prepolymer, and more preferably 50 to 25.
It is 00 copies. (5) Manufacturing Method In the manufacturing method of the present invention, the prepolymer solution is cast on a molding belt conveyor, and the excipient is uniformly dropped onto the prepolymer solution and immersed in the solution. It is carried out by accelerating the curing with light, an electron beam, etc., continuously taking out the formed sheet-like material from the end of the conveyor, and then drying it if necessary. At this time, in order to help the uniform dispersion of the excipient, it is effective to apply vibration to the belt conveyor by a vibrator or the like to further homogenize the mixing and homogenize the thickness. The vibrator in this case may be a commercially available one. It is desirable that the excipient is supplied to the lower molding conveyor via a conveyor as much as possible. The material of this supply conveyor may be either resin or steel, and its width is preferably 90 to 300 cm in the case of building materials and the like. A sheet-like material having a thickness of 0.5 mm to 20 cm can be obtained by the above method, but it is usually preferable that the thickness is in the range of 1 mm to 10 mm. [Operation] A prepolymer solution is continuously cast on a belt conveyor, and an excipient selected from the group consisting of plant fine fibers, plant powder particles, inorganic fibers or inorganic powder particles is continuously cast thereon. When dropped, the mixture cures while traveling on the belt, so that a sheet-like material can be continuously obtained. Therefore, according to this method, while avoiding the obstacle that the resin mixture adheres to the kneader or the like during kneading or adheres to the press at the time of pressing after spreading, the work cannot be continued, economically It becomes possible to mass-produce sheet-shaped products useful as building agents and the like. [Examples] Hereinafter, embodiments and effects of the invention will be shown by examples and comparative examples, but the examples are, of course, for explanation, and do not mean limitations or restrictions of the inventive idea. Example 1 Using the apparatus shown in FIG. 1 attached, a belt conveyor having a width of 2 m is continuously supplied while the polyethylene film 3 for mold release is closely attached to the surface from the tension holding device 2 for mold release polyethylene film at a speed of 3 m / min. Approximately 2 when diluted from the prepolymer solution feeder 4 to 10% water while moving with
Urethane prepolymer with the property of gelling in minutes (terminal
NCO5%) at a rate of 2 / min, water at a rate of 20 / min,
Each of them was uniformly and continuously supplied onto the belt conveyor while mixing (reference numeral 8 for mixed aqueous solution). At a position within 2 m from the supply port of the aqueous solution, a wood powder (particle size 20 to 40 mesh) 9 having a water content of 30% was uniformly dropped at a rate of 6 kg / min from the hopper 5 through the constant amount feeder 6. The belt conveyor 1 was vibrated by a vibrator (manufactured by Shinko Electric Co., Ltd.) 7 in the range of 1 m to 2 m from the dropping position of the wood powder 9 to completely immerse the wood powder in the urethane aqueous solution. The prepolymer / wood flour mixture on the belt conveyor started to thicken at a position of about 3.5 m from the supply port of the urethane aqueous solution, and gelled with wood powder contained at a position of about 6 m. The obtained hydrogel sheet has an adhesive force of 240 g and a thickness of 5 m.
It was a uniform sheet of m and 2 m in width. When the obtained hydrous gel sheet was dried to a water content of 10% or less, a highly flexible continuous sheet (having a radius of curvature of 1 cm or less) having a density of 0.30 g / cm ³ and a wood powder content of 75% was obtained. This flexible sheet is useful as a building material. Example 2 In Example 1, pearlite (bulk specific volume: 3.5 ml / g, average particle size: 5 mm) was continuously dropped at a rate of 10 kg / min instead of wood flour. The resulting hydrogel containing perlite was a uniform sheet having an adhesive force of 215 g, a thickness of 5.8 mm and a width of 2 m. When the hydrogel sheet was dried to a water content of 10% or less, it became a flexible continuous sheet having a pearlite content of 83% and a density of 0.21 g / cm ³ . Example 3 In Example 1, instead of the urethane prepolymer aqueous solution, polyethylene glycol (number average molecular weight 20
00) dimethacryl ester of 3.0 kg / min, sodium persulfate of 0.02 kg / min, ammonium persulfate of 0.05 kg / mm and warm water (water temperature 65 ° C) at a rate of 20 / min were mixed and supplied (the gel of the mixed solution). Approximately 10 minutes). Thereafter, in the same manner as in Example 1, a hydrous gel sheet containing wood powder having a thickness of 5.5 mm and a width of 2 m was obtained. When this was dried to a water content of 10% or less, a flexible continuous sheet having a wood powder content of 68% (a bending curvature radius of 3.5 cm) was obtained. Comparative column A mixture of 2 kg of the urethane prepolymer of Example 1, 20 kg of water and 6 kg of wood flour was mixed with a kneader and tried to spread on a belt having a width of 2 m, but the viscous mixture adhered to the inner wall of the kneader. Therefore, continuous mixing was difficult. Moreover, when the mixture of the wood powder and the resin on the belt conveyor was rolled with a Teflon-coated roll, the resin adhered to the roll and became a dumpling of the mixture on the conveyor,
It could not be spread evenly.

【The invention's effect】

The production method according to the present invention continuously mixes a fast curing prepolymer, vegetable fine fibers, inorganic fibers, and the like,
It contributes to the economical production of building materials, which provided a method for uniformly and economically obtaining a sheet containing a relatively small amount of resin components.

[Brief description of the drawings]

FIG. 1 is a model diagram showing an example of a sheet-shaped material molding apparatus that can be used for implementing the present invention. The symbols in the figure have the following meanings: -1: belt conveyor; 2: release film tension holding device; 3: release film; 4: prepolymer solution supply device; 5: excipient hopper; 6 : 5 quantitative supply device; 7: vibrator; 8: prepolymer solution; 9: excipient.

Claims (3)

(57) [Claims] 1. A continuous supply on a belt conveyor,
Obtained from the group consisting of vegetable fine fibers, vegetable fine particles, inorganic fine fibers and inorganic fine particles on a prepolymer solution (A) which is uncured and has a high curing rate or which exhibits tackiness in the curing process after feeding. A method for producing a continuous sheet, characterized in that at least one excipient (B) is continuously and uniformly dropped. 2. The manufacturing method according to claim 1, wherein the conveyor is vibrated. 3. A continuous sheet produced by the method according to claim 1.