JP2004338369A - Binder composition for vegetable fibrous board and manufacturing method for vegetable fibrous board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a vegetable fibrous board which is good in mold releasability at the time of manufacturing and excellent in water resistance and mechanical properties, and a binder composition used for the same. <P>SOLUTION: The manufacturing method for the vegetable fibrous board is constituted as follows. The binder composition for the vegetable fibrous board is composed of an organic isocyanate (A) and a radical polymerization initiator (C) and further in some cases a fatty acid ester compound (B) having double bonds in the molecule. The above binder composition for the vegetable fibrous board is mixed to a vegetable fibrous material. Next, the mixture is molded into the board shape. The radical polymerization is executed to it to make the board. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a plant fiber board having excellent release properties and water resistance and excellent mechanical properties, and a binder composition used therefor.

Boards such as particle boards or fiber boards in which wood chips or fibers are combined with a binder have been industrially produced since about 1950 as furniture materials, building interior materials, roof shingles, and the like. As the binder used for the production, melamine / formaldehyde resin, phenol / formaldehyde resin, urea / formaldehyde resin, organic polyisocyanate, and the like are used.
However, when an organic polyisocyanate is used as the binder for the board, the adhesive strength and water resistance are superior to other resin-based binders, and there are advantages such as not releasing harmful formaldehyde at the time of hot pressing. There is a disadvantage that the product board strongly adheres to a metal hot plate, a cowl plate, a mold, or the like at the time of tightening, and it becomes difficult to take out the product.
This disadvantage can be solved to some extent by inserting a release sheet in advance into a hot platen, a cowl plate, a mold or the like prior to pressing or applying a release agent for each hot pressing step. It is not practical because the manufacturing process becomes complicated.

  Further, a method of producing a multilayer particle board using a hydrophilic urethane prepolymer has also been proposed (see Patent Document 1). However, the obtained board has water resistance, specifically, a swelling ratio upon water immersion. There is a problem of being large.

  Furthermore, in order to solve the problem of releasability at the time of hot pressing, a method of manufacturing a particle board or a fiber board using a wood chip or fiber and a urethane resin-based binder has been proposed (see Patent Document 2). ), The mechanical properties such as the peel strength of the obtained board are not practically sufficient.

JP-A-62-59004 JP-A-2-214602

  The present invention solves the above-mentioned problems of the prior art, and provides a method for producing a plant fiber board having excellent release properties during production, excellent water resistance and excellent mechanical properties, and a binder composition used therefor. The purpose is to provide.

  The present inventors have conducted intensive studies and found that the above problem can be solved by using a radical polymerization initiator in an organic polyisocyanate or a fatty acid ester compound having a double bond in the molecule in some cases, The present invention has been completed.

That is, the present invention is a binder composition for a plant fibrous board, comprising the following (A) and (C).
(A) Organic isocyanate (C) radical polymerization initiator

Further, the present invention is a binder composition for a vegetable fibrous board, which comprises the following (A), (B) and (C).
(A) Organic isocyanate (B) Fatty acid ester compound having double bond in molecule (C) Radical polymerization initiator

  Further, the present invention provides a method for producing a plant fibrous board, which comprises mixing the above-mentioned binder composition for a plant fibrous board with a plant fibrous material, forming the mixture into a board shape, and subjecting the mixture to radical polymerization. Is the way.

  For the first time according to the present invention, a method for producing a plant fibrous board having good mold release properties during production, excellent swelling rate, water resistance such as water absorption and peel strength, and excellent mechanical properties such as bending strength, and the like. It has become possible to provide a binder composition.

Hereinafter, the present invention will be described in detail.
Examples of the organic isocyanate (A) used in the present invention include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate. Polyphenylenepolymethylene polyisocyanate (hereinafter referred to as Polymec MDI) containing 30 to 70% by mass of a mixture of '-diphenylmethane diisocyanate and 2,2'-diphenylmethane diisocyanate, and 70 to 30% by mass of a polynuclear body having a trinuclear body as a main component. ), And aromatic polyisocyanates such as 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate. Of these, diphenylmethane diisocyanate-based polyisocyanate is preferred, and polymeric MDI is preferred because of its low vapor pressure and low crystallization at low temperatures.
In addition, aromatic diisocyanates such as phenylene diisocyanate, xylylene diisocyanate, aromatic aliphatic diisocyanates such as tetramethyl xylylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 3-methyl-1,5-pentane diisocyanate, lysine diisocyanate, etc. Alicyclic diisocyanates such as aliphatic diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethyl xylylene diisocyanate are also included.
Those in which a part of these isocyanate groups are modified into biuret, allophanate, carbodiimide, uretonimine, isocyanurate (trimer), uretdione (dimer), oxazolidone, amide, imide and the like can also be used.
Further, those obtained by modifying these into a water emulsified type can also be used.
These can be used alone or in combination of two or more.

Examples of the (B) fatty acid ester compound having a double bond in the molecule used in the present invention include castor oil and its alkylene oxide adduct, transesterified product with castor oil-based polyhydric alcohol, and polyvalent. Alcohol ricinoleate or ricinoleate polyol, partially acylated or partially oxidized castor oil, tung oil, soybean oil, linseed oil, polyhydric alcohol oleate, polyhydric alcohol linoleate, polyhydric alcohol Examples thereof include esters of higher unsaturated fatty acids such as linolenic acid esters, polyols and acrylic polyols containing these as main components. Further, unsaturated polyesters having a double bond in the molecule, obtained by condensing a polyhydric alcohol represented by glycols such as ethylene glycol and an unsaturated polycarboxylic acid such as maleic acid or fumaric acid, may also be mentioned. Further, there may be mentioned those obtained by using a vinyl monomer such as styrene, diallyl phthalate and divinylbenzene in combination with the unsaturated polyester. Further, those obtained by modifying these into a water emulsified type can also be used. Of these, esters of higher unsaturated fatty acids, particularly glycerides, are preferred.
These can be used alone or in combination of two or more.

Examples of the radical polymerization initiator (C) used in the present invention include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, and 2,2'-azobisisobutyric acid Dimethyl, azobiscyanovaleric acid, 1,1'-azobis- (cyclohexane-1-carbonitrile), 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobis- (4-methoxy Azo compounds such as -2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexa 1,1-bis (t-butylperoxy) cyclododecane, n-butyl-4,4-bis (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, t- Butyl hydroperoxide, diisopropylbenzene hydroperoxide, p-menthane hydroperoxide, t-hexyl peroxide, 1,1,3,3-tetramethylbutyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, Di-t-butyl peroxide, isobutyroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, succinic peroxide, benzoyl peroxide, toluylbenzo Luperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, di-2-ethoxyethylperoxydicarbonate, di-2-methoxybutyl Peroxydicarbonate, di-2-ethylhexylperoxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate, α, α′-bis (neodecanoylperoxy) diisopropylbenzene, cumylperoxy Neodecaneate, 1,1,3,3-tetramethylbutylperoxyneodecanate, 1-cyclohexyl-1-methylethylperoxyneodecanate, t-hexylperoxyneodecanate, t-butylperoxyneone Decanate, t- Xyl peroxypivalate, t-butyl peroxypivalate, 2,5-dimethyl-2,5-bis (2-ethylhexylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2- Ethyl hexanate, 1-cyclohexyl-1-methylethyl peroxy-2-ethyl hexanate, t-hexyl peroxy-2-ethyl hexanate, t-butyl peroxy-2-ethyl hexanate, t-butyl peroxy Isobutylate, t-butyl peroxy laurate, t-butyl peroxy-3,5,5-trimethyl hexanate, t-hexyl peroxyisopropyl monocarbonate, t-butyl peroxyisopropyl monocarbonate, t-butyl peroxy Oxy-2-ethylhexyl monocarbonate, 2,5-dimethyl Tyl-2,5-bis (benzoylperoxy) hexane, 2,5-dimethyl-2,5-bis (m-toluoylperoxy) hexane, t-butylperoxyacetate, t-hexylperoxybenzoate, t Organic peroxides such as -butylperoxy-m-toluoylbenzoate, t-butylperoxybenzoate, and bis (t-butylperoxy) isophthalate. Further, those obtained by modifying these into a water emulsified type can also be used.
These can be used alone or in combination of two or more.

  In the binder composition of the present invention, the fatty acid ester compound (B) is preferably used in an amount of 500 parts by mass or less, more preferably 10 to 250 parts by mass, particularly preferably 20 to 100 parts by mass, based on 100 parts by mass of the organic isocyanate (A). . (C) The radical polymerization initiator is preferably used in an amount of 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass based on 100 parts by mass of the total amount of the organic isocyanate (A) and the fatty acid ester compound (B). preferable.

Examples of the plant fiber material used in the present invention include wood (eg, lauan wood) chips, bark, wood fiber, rice husk, straw (such as wheat straw, rice straw, and cereal straw), bacas, cork, bamboo, flax, and jute. (Kima). There is no particular limitation on these shapes, but it is preferable to use them in the form of chips. Of these, straw is the most advantageous in terms of economy.
These can be used alone or in combination of two or more.

  In the present invention, a laminated wood (for example, OSB) made of a plant fiber material having a thickness and shape capable of sufficiently transmitting heat to the inside during board formation can be suitably used.

  In the present invention, the method of mixing the binder composition with the plant fibrous material can be arbitrarily selected depending on the situation. For example, (A) (A) an organic isocyanate and (C) a radical polymerization initiator and optionally (B) ) The fatty acid ester compound is preliminarily mixed before use and then blended with the plant fiber material, or (B) the plant fiber material is optionally blended with (B) the fatty acid ester compound beforehand, and The isocyanate and the (C) radical polymerization initiator may be blended in any order. Further, (A) an organic isocyanate, (C) a radical polymerization initiator, and optionally (B) a fatty acid ester compound may be diluted or dispersed with water or an organic solvent and sprayed.

  In the method for producing a plant fibrous board of the present invention, the binder composition is 0.1 to 50 parts by mass, more preferably 0.5 to 25 parts by mass, particularly 1 to 10 parts by mass with respect to 100 parts by mass of the plant fibrous material. It is preferable to mix them.

The radical polymerization in the production of the plant fiber board of the present invention is carried out under the conditions of pressurizing and heating the molded board production mixture such as a hot press, specifically, for example, 50 kg / cm ² or less, at 100 to 250 ° C. It is preferable to carry out the treatment by treating for 5 to 1000 seconds.
By treating the mixture for board production under the above-mentioned pressurized and heated conditions, the organic isocyanate (A) reacts with the water in the straw and the hydroxyl group present in the molecule of the straw and (B) the fatty acid ester compound, and (B) The double bond in the fatty acid ester compound molecule can be radically polymerized to form a board.

Hereinafter, the present invention will be described in more detail by way of examples.
Example 1
1000 g of straw chips were put in a rotary blender drum, and a mixture of 30 g of Polymeric MDI (WC-220 manufactured by Nippon Polyurethane Industry Co., Ltd.), 30 g of castor oil and 0.3 g of dicumyl peroxide was sprayed while rotating. The particle size distribution of the straw chips is shown in FIG.
The mixture treated straw chips packed in a uniform thickness in crates carrying on Kouru plate (300 × 300 × 150mm), after removal of the wooden frame, 160 ° C. in pressurized hot plate, of 20 kg / cm ² The board was manufactured by heat-tightening under the conditions for 5 minutes.
The obtained board was easily released from the cowl plate.
Table 1 shows the measurement results of the physical properties of the board according to JIS A5908, together with the raw material composition.

Example 2
A board was manufactured and physical properties were measured in the same manner as in Example 1, except that 40 g of polymeric MDI, 10 g of castor oil and 10 g of tung oil were used instead of 30 g of polymeric MDI and 30 g of castor oil.
The obtained board was easily released from the cowl plate.
Table 1 shows the physical properties and raw material composition of this board.

Example 3
A board was manufactured in the same manner as in Example 1 except that 30 g of tung oil was used instead of 30 g of castor oil, and physical properties were measured.
The obtained board was easily released from the cowl plate.
Table 1 shows the physical properties and raw material composition of this board.

Example 4
A board was manufactured in the same manner as in Example 2 except that castor oil and tung oil were not used, and physical properties were measured.
The obtained board was easily released from the cowl plate.
Table 1 shows the physical properties and raw material composition of this board.

Comparative Example 1
A board was manufactured in the same manner as in Example 1 except that dicumyl peroxide was not used, and physical properties were measured.
The obtained board was easily released from the cowl plate.
Table 2 shows the physical properties and raw material composition of this board.

Comparative Example 2
A board was manufactured in the same manner as in Example 2 except that dicumyl peroxide was not used, and physical properties were measured.
The obtained board was easily released from the cowl plate.
Table 2 shows the physical properties and raw material composition of this board.

Comparative Example 3
A board was manufactured in the same manner as in Example 3 except that dicumyl peroxide was not used, and physical properties were measured.
The obtained board was easily released from the cowl plate.
Table 2 shows the physical properties and raw material composition of this board.

Comparative Example 4
A board was manufactured in the same manner as in Example 4 except that dicumyl peroxide was not used, and physical properties were measured.
The obtained board was easily released from the cowl plate.
Table 2 shows the physical properties and raw material composition of this board.

It is a graph which shows the particle size distribution of the straw chip used in Examples 1-4 and Comparative Examples 1-4.

Claims (3)

A binder composition for a vegetable fiber board, comprising: (A) and (C):
(A) Organic isocyanate (C) radical polymerization initiator A binder composition for a vegetable fibrous board, comprising: (A), (B) and (C):
(A) Organic isocyanate (B) Fatty acid ester compound having double bond in molecule (C) Radical polymerization initiator 3. A method for producing a plant fiber board, comprising mixing the plant fiber material with the binder composition for a plant fiber board according to claim 1 or 2, and then forming the mixture into a board and subjecting the mixture to radical polymerization. Method.

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