JPH02164507A - Manufacture of board - Google Patents

Abstract

PURPOSE:To prevent from adhering to a heated metal surface, by making use of an organic polyisocyanate as the binder of a lignocellulose substance. CONSTITUTION:Hot press molding of a lignocellulose substance such as a wood piece or a wood fiber or chips is performed by making use of an organic polyisocyanate compound containing at least two isocyanate groups in a molecule and/or a terminal prepolymer of its isocyanate group for the same as a binder. Prior to the molding, monolithic molding is performed by making use of polyvinyl chloride polyurethane composite resin film as a board surface coating material. The polyvinyl chloride polyurethane composite resin film is set to a cowl plate and heated within a hot press for the monolithic molding. Organic polyisocyanate whose adhesion and water resistance are favorable is used as the binder in an obtained board and a surface film also can be selected variously in accordance with use.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for manufacturing a board. More specifically, a lignocellulose material is used as a base material, an organic polyisocyanate compound containing isocyanate groups of K2 (lid or more in the 9 molecules) and/or its isocyanate group-terminated prepolymer as a binder, and a board covering material. By using a polyvinyl chloride polyurethane composite resin film, it is possible to prevent the board from adhering to hot metals, and at the same time, the board has excellent strength, water resistance, surface properties, etc., and it relates to a method for integrally molding and manufacturing the next board. [Prior Art] The use of organic polyisocyanates as a binder is conventionally known in the production of boards based on lignocellulosic materials, such as particle boards, fiber boards, wafer boards, flake boards, etc. Conventionally, boards are formed by applying organic polyisocyanates in the form of solutions or water emulsions to lignocellulosic materials and then subjecting them to hot pressing. It is also known to use condensate resin as a binder and to be of a higher quality than the next board. However, this high adhesion does not result in significant adhesion of the lignocellulosic material to the hot metal surfaces in contact during the heat press operation. Although many attempts have been made to overcome this adhesion problem, no completely satisfactory solution has been found.
No. 5-49245, No. 55-160013,
Methods for solving this adhesion problem have been proposed in Japanese Patent No. 55-160014, Japanese Patent No. 57-131538, B, P No. 4110397, and the like. However, none of these methods has led to a sufficient solution. In addition, board manufacturing using veneer, melamine decorative paper, etc. as board covering materials has been put into practical use, but there are many problems such as poor workability and excessive cost, and improvements are desired. Good friend. Problem to be Solved by the Invention The object of the invention is to produce high quality boards by using organic polyisocyanates as binders for lignocellulosic materials. Completely eliminates the problem of adhesion to hot metal surfaces, which is the most serious drawback,
Abrasion resistant, oil resistant, weather resistant, heat resistant. To provide a method for manufacturing a board with excellent water resistance and mechanical strength. As a result of extensive research and consideration, the present inventor has found that organic polyisocyanate compounds containing two or more isocyanate groups in the molecule and/or isocyanates thereof are used as binders when manufacturing boards using lignocellulose materials as base materials. By using a base-terminated prepolymer and using a film of polyvinyl chloride polyurethane composite resin as a board surface coating material to solve the adhesion problem and improve the physical properties of the board, we have achieved extremely high performance of organic polyisocyanates as a binder. The present invention was completed after discovering that the characteristics can be utilized to the maximum extent. (Means for Solving the Problems) That is, the present invention provides 9
When hot-press molding is performed using an organic polyisocyanate compound containing two or more isocyanate groups in the molecule and/or its isocyanate group-terminated prepolymer, a film of polyvinyl chloride polyurethane composite resin is used as a board surface coating material. This is a method of manufacturing a board characterized by integral molding. The lignocellulosic material used in the present invention is: Wood chips, wood fibers, shavings, wood wool, cork, tree bark. Mention may be made of sawdust and woodworking waste, and may further include bagasse, straw, flax, rush, perilla, and grasses. These lignocellulosic materials may also be supplemented with other granular or fibrous materials such as glass fibers, mica, and asbestos. Examples of organic polyisocyanate compounds used in the present invention, which may be mixed with rubbers and plastic materials, include tolylene diinocyanate with a functional number of 2 or more, xylylene diisocyanate, kaftere/diisocyanate, diphenylmethane diisocyanate, Phenylmethane polyisocyanate, biphenylene diisocyanate, diphenyl ether diisocyanate, toridine diisocyanate, hexamethylene diisocyanate,
Examples include Inholo/Diisocyanate Gin, as well as these isocyanate derivatives and similar compounds thereof alone or in mixtures of two or more. Further, the isocyanate group-terminated prepolymer can be obtained by reacting an organic polyisocyanate compound with a polyol having active hydrogen. As the polyol having active hydrogen for the core prepolymer, any polyol having at least two or more hydroxyl groups in one molecule can be used. Typical examples include polyester polyols, polyether polyols, epoxy polyols, etc., and a combination of two or more of these polyols can also be used. Examples of polyester polyols include ethylene glycol, diethylene f IJ =y -l, ) I
J ethylene glycol, 1,2-7'robylene glycol, trimethylene glycol, 1,3-f. Tylene glycol, tetramethyl glycol. hexamethylene glycol, decamethylene glycol,
glycerin, sorbitol, trimethylolpropane,
1 m or 2 or more compounds having at least 2 or more hydroxyl groups such as pentaerythritol, malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, sebacin m! , cydianic acid, phthalic acid, terephthalic acid. It can be produced by a known method using one or more compounds having at least two carboxyl groups, such as azelaic acid and trimellitic acid 1. Also included are lactone-based polyesters obtained by abdominally polymerizing heptads having a lacto ring, such as ε-cablockone and a-valerolactone. Examples of polyether polyols include ethylene glycol. Diethylene glycol, triethylene glycol #, l,
2-Glopylene glycol, trimethylene glycol,
1.3-Butylene glycol. Tetramenale/Glycol, Glycerin, Sorbitol, Shake Rose, Bisphenol A. One or more compounds having at least two active hydrogen atoms, such as pentaerythritol, are used as a polyol starting compound, and monomers such as styrene oxide, propylene oxide, butylene oxide, alkylene oxide such as styrene oxide, and epichlorohydrin having carbon B2 or more are used. It is produced by addition polymerizing 1 or 2 fi or more of the following by a known method. Also, for polyols having these active hydrogens. General formula R104R*QH (R1: amgyl group, R1:
Molecular weight 2 represented by alkylene group, n: 5-90)
50-4000 alkoxy polyalkylene glycols are also included. This is because the isocyanate group-terminated prepolymer modified with alkoxypolyalkylene glycol has self-vaporizing properties. It is most useful as a binder for lignocellulose filtration materials because it can be used in the form of a water emulsion. The polyvinyl chloride polyurethane composite resin used as the board surface coating material in the present invention is disclosed in Japanese Patent Application Laid-Open No. 61-1208.
12 and 61-120820, that is, polyol-containing polyols obtained by graft polymerization of polyols soluble in vinyl chloride monomers and vinyl chloride monomers. It is provided by a method of manufacturing by reacting vinyl chloride with an isocyanate compound. Other composite methods include JP-A-58-40312, JP-A-58-42611, and JP-A-5B-370i9.
No. 58-5357, No. 61-25004
As described in Publication No. 4, etc., it is possible to freely change the hardness of a molded product without using a plasticizer, and it is used in the present invention because it has the characteristics of two base materials. The composite resin film has the following characteristics: Although the binder used in the present invention has a high level of adhesive performance, it has a drawback in its adhesive performance with polyvinyl chloride resin. However, since polyvinyl chloride polyurethane composite resin has the properties of polyurethane resin, it has become possible to bond the board and surface coating material into one piece using a binder9. This provides a manufacturing method that is extremely superior in terms of cost and workability since steps such as adhesive application can be omitted. The composite resin film used in the present invention can be manufactured as long as it has a thickness of 30 microns or more, and the selection of the thickness is determined by considering the characteristics of the board. The hardness is in the range of 50-100 in terms of A hardness, and is determined by the type and composite ratio of the polyvinyl chloride resin and polyurethane resin. Normally, the range of composite ratio of polyvinyl chloride resin and polyurethane resin is 1 by weight.
00/20~100/150, 100150~
100/100 is desirable. Further, the flow value (+j/see) measured by a 70-tester at 180'C is in the range of 101 to 10@. The board of the present invention is manufactured as follows. On the production line, the surface coating material that is set on the lower surface is set on the cowl plate at a stage before the cowl plate leaves the hot press and enters the forming machine. The surface coating material set on the top surface is set either continuously or as a cut film on the forming mat exiting the 7 ohming machine. In a line that includes a prepress process, it may be used before or after prepress. If the surface coating material on the top surface is thin and unstable on the mat, a process of further setting a cowl plate on top of it may be adopted. After this, hot press internal pressure feed 140'C-J20
00C. Preferably, it is integrally molded by hot pressing at 150°C to 180'C. The hot pressing time is 15 seconds to 25 seconds per board thickness of 1 mm, and usually 16 seconds to 20 seconds. In addition, in the case of a continuous production line that uses an endless steel belt, the surface coating material that can be set on the bottom side is continuously fed onto the steel belt in front of the forming machine, and the surface coating material that can be set on the top side is fed through a heat press. It is continuously fed into a rotating drum that plays the role of By changing the type of surface coating material, i.e. hardness, the board manufactured by the method of the present invention, the physical properties of the board, the surface characteristics of the board, etc. can be varied in various ways, as well as the coloring of the film. Since embossing etc. are extremely easy, boards with a wide variety of designs can be obtained. In addition, the problem of adhesion to hot metal surfaces when organic polyisocyanates are used in all layers is solved, and the resulting board surface is wear-resistant. The board manufactured by the method of the present invention has excellent oil resistance, weather resistance, heat resistance, water resistance, and mechanical strength, and can be applied to an extremely wide range of fields. Organic polyisocyanates with excellent water resistance etc. are used. 1. A special composite resin film with dominant genetic properties of polyvinyl chloride and polyurethane is used as the surface coating material. hardness. Because the thickness can be changed extremely freely, it is extremely easy to color, embossing is easy, and it has excellent design, it is of course used in fields where lignocellulose-based boards are currently used. I think it can also be applied to fields where plastics are used. In terms of applications 1-1, it can be applied to many fields such as building materials, kitchen equipment materials, furniture materials, electrical appliance materials, audio equipment materials, and musical instrument materials. Furthermore, since we have an extremely high-quality board, it is possible to reduce the specific gravity of the board, which provides great benefits in terms of cost and four working surfaces during secondary processing. [Examples] The present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Further, unless otherwise specified, parts and parts in Examples and Comparative Examples refer to "parts by weight" and "parts by weight", respectively. Example 1 Create 3M particle board using the following method

[7. As a binder, self-emulsifying polyphenylmethane polyisocyanate (Coronet) 3 Q 53. Nippon Polyurethane Kogyo ff, NCO content f#29.5%) was applied in the form of water emulsion, and the A0 surface coating material was polyvinyl chloride polyurethane I synthetic resin film (Dominus 902B, Nippon Polyurethane Kogyo g, thickness 0). ．．
2 mm, A hardness 90) was used on both sides. Board creation conditions Gate size: 400 x 400 x 12 (mm) Oil content: Surface layer / core layer = 8/4 (chi) Matt moisture content 2 surface layer / core layer = 15/8 (%) Forming ratio: surface layer / core layer = 15/8 (%)
Core layer/surface layer = 25150/25 (h) Press pressure: 2
5 (k!?/a4) Press temperature: 160 ('C) Press time: 3.5 (minutes) Board density: 0.7 (VctA) Board physical properties Normal bending strength: 248 (kl?/cn) Wet bending Strength (100°C x 2hr): 133 (L
y,, () Water resistance = Thickness swelling rate 6.4 (%) (2
5° (::x24hr) Water absorption rate 15.2 (%)
Film adhesive strength 3.4 (kg/lo) Comparative Example 1 A second board was prepared under the same conditions as Example 1 except that no surface coating material was used. However, release paper was used on the top F of the mat to prevent it from adhering to the hot plate. Board physical properties Normal bending strength: 204 (ψ steel) Wet bending strength IjL (100°C x 2hr): 1
04 (kfV/cj11) Water resistance: Thickness swelling rate 8.
6 (%) (25°Cxz4hr) Water absorption rate 21.6 (%) Example 2 A three-layer particle board was manufactured by the following method. Polyphenylmethambo-lisocyanate (Millionate MR)
-200. Nippon Boliureta/Made by Kogyo, NCO content 31.
1ch) 970 parts of polyether polyol and Nabor PP-700. After adding 64 parts of methoxypolyethylene glycol (MPG-081, manufactured by Nippon Nyukazai IiJ) and reacting at 80°C for 3 hours, a self-emulsifying polyphenylmethane polyinocyanate was obtained. Obtained. The NCO content of this prepolymer is 26.
It was 7chi. A board was prepared under the same conditions as in Example 1 using this prepolymer as a binder. The surface coating material is polyvinyl chloride polyurethane composite resin film (Dominus K 70).
0 F, Japan Polyurethane In, thickness 0.15mm,
A Hard 1170) was used on both sides. Board normal bending strength = 236 (kg15 damp 6゛4 hour bending strength (100°CX2hr): uts (ky/,
:Hi)Water resistance :Thickness swelling rate 5.8(chi)(2
5°C x 24hr) Water absorption rate 14.3 (%) Film adhesive strength gt: 3.6 (kq 710m) Comparative Example 2 A board was created under the same conditions as Example 2 except that no surface coating material was used. Ta. However, in order to prevent it from adhering to the hot plate, the upper and lower rc of the mat
I used M-pattern paper. Board physical properties Normal bending strength + 1c + 7 (k!g/cm) 15J-
Bending strength at f3 (100°CX 2hr): 96
(ky/cd) Water resistance: Thickness expansion ratio: 92 (%) (25°C x 24 hr) Water absorption: 20.6 (%) Example 3 A three-layer particle board was manufactured in the following manner. 3053 was used as the binder, and 0.5 m thick of the film used in Example 1 was used as the surface coating material.
Next, use the rnO one. The manufacturing conditions were the same as in Example 1 except that the board density was 0169/cd. Board physical properties Normal bending strength: 185 (Y/-) Strong bending when wet (1000CX21ir): 85 (k)
l? /i) Water resistance: Thickness expansion rate n 7.5 (ch) (25°C x 24 hr) Water absorption rate 16.7 (%) Film adhesive strength: 2.7 (y/l Om) Comparative example 3 Surface @, A board was made using the same materials and under the same conditions as Example 3, except for the strength. However, release paper was used on the top and bottom of the mat to prevent it from adhering to the hot plate. Board physical properties Normal bending strength: 143 (Y/R) Bending strength when wet (100'CX2br) + 66 (
k#/+: Shoulder) Water resistance: Thickness expansion*8.9 (%) (25°CX24hr) Water absorption rate 23.0 (%) Example 4 A three-layer verdicle board was manufactured in the following manner. The prepolymer used in Example 2 was used as the binder and L-1.
The film used in Example 3 was used as the surface coating material. Fat content/! -Surface layer/core layer=(5/3 except that the manufacturing conditions are the same as in Example 1. Board physical properties normal bending strength: 20BC', 9/cd>wet bending strength (100'C x 2hr) +10102 (/cJ)
Water resistance: lv moisture rate 7.8 (%) (25°CX
24hr) I & water ratio 17.4 (%) Film adhesive strength: 2.8 (kl/, /10) Comparative Example 1 A board was prepared under exactly the same conditions as Example 4 except that no surface coating material was used. Created. However, release paper was used on the top and bottom of the mat to prevent it from sticking to the hot plate. Board physical properties Normal bending strength: l 78 (k&/crl) Wet bending strength jll'-(100'CX2br): 82 (
kg/csJ) Water resistance: L'J [swelling rate 9.6
(%) (25°C x 24hr) Water absorption rate 21.0 (-
9) Comparative Example 5 Create a 3N particle board as follows. Binding agent - Urine-A resin (NO, 170B, manufactured by Oshikashin FS,
Solid content: 66 cm) was used. The same film as in Example 1 was used as the surface covering material. The preparation conditions were the same as in Example 1 except for the following: fat content t - surface layer/core layer = 14/'J. Physical properties of the board The surface coating material was not adhered to the surface, and the physical properties of the board were measured without surface coating. Normal bending strength I! L: 200 (kg/csl)rnl
Bending strength at A [(loO'cx2hr): 0 (kP/d)
Water resistance: Thickness swelling rate 15 (ch) Water absorption rate 50 (ch)

Claims (1)

[Claims] As a binder for lignocellulosic materials, an organic polyisocyanate compound containing two or more isocyanate groups in the molecule and/or its isocyanate group-terminated prepolymer is used as a board surface coating material when hot-pressing is used. A method for manufacturing a board characterized by integral molding using a polyvinyl chloride polyurethane composite resin film.