WO1997017412A1 - Adhesive and boards made by using the same - Google Patents

Abstract

An adhesive prepared by using a waste pulp liquor, having excellent strengths, a high content of components derived from the waste liquor, and a marked economic advantage over commercially available thermosetting resin adhesives; and lignocellulose boards made by using this adhesive. The adhesive comprises a waste pulp liquor and a product of a reaction of a phenol compound with formaldehyde, wherein at least 30 % by weight of nonvolatile components are ones derived from a waste pulp liquor of a gramineous plant. The lignocellulose boards are practicable ones, such as a particle board or a fiber board, made by mixing the above adhesive with small pieces of a lignocellulosic substance and heating and pressing the mixture to form a board, wherein at 30 % by weight of nonvolatile components in the adhesive is ones derived from a waste pulp liquor of a gramineous plant.

Description

 Meitoda adhesives and boards using them

 The present invention relates to an adhesive using pulp waste liquid, and a lignocellulose-based board such as a particle board or a fiber board using the same.

 Background art

 The paper valve industry in Japan and the United States and Europe has relied substantially on wood for its raw materials. In these countries, serious environmental pollution problems due to valve effluents have been experienced, and the use of pulp effluents as a raw material for phenol aldehyde resin adhesives has begun.

 Most of these studies use lignin that is produced by separation and purification from valve wastewater. For example, [Wood Industry 24, p84, Hanui et al. (19669) J, 5 3 2 8 4 6 2 gazette, Japanese Patent Publication No. 62-56-193, Tokiohei 6 5 6 9 6 7 gazette, Japanese Patent Publication 7-5 3 8 58 8 gazette Is raised. However, lignin has a cost for purification. In fact, the price of commercially available lignin is higher than that of urea and formalin, which are the raw materials for general wood adhesives, and is almost equal to that of I: nol and melamine. Lignin is a component of waste liquid, and using lignin alone does not fundamentally solve the problem of waste liquid treatment.

 —Some use pulp waste liquid as it is (Japanese Patent Publication No. 51-224,977, Japanese Patent Publication No. 54-157,988, Japanese Patent Publication No. 60-220) No.). However, JP-B-54-157798 and JP-B-62-224 require the use of a larger amount of phenol than the valve waste liquid component in order to obtain sufficient strength performance. And Japanese Patent Publication No. 51-222497 discloses the use of 50 to 100 parts of phenol per 100 parts of solid content of sulfurous acid valve waste liquid, but the production process is complicated. However, its cost is lower than that of commercially available urea resin adhesives and melamine resin adhesives.

As described above, conventional adhesives require complicated manufacturing processes or commercially available adhesives for wood. It has not been put into practical use either for the strength performance of the agent or has no advantage in the cost of raw materials, or for all reasons.

 On the other hand, in China and Southeast Asian countries, pulp is produced not only from wood but also from non-wood such as bamboo, rice straw, wheat straw, ash, flax, and kenaf. Environmental pollution due to a sudden increase in valve waste liquid has become a problem.

 The present invention uses a valve waste liquid (black liquor), exhibits excellent strength performance, has a high ratio of components derived from the valve waste liquid, and is extremely economically advantageous as compared with a commercially available thermosetting resin adhesive. An object of the present invention is to provide an adhesive and to provide a lignocellulose-based board having good performance by using such an adhesive.

 Disclosure of the invention

 In the conventional method, practically, only wood pulp waste liquid was used, and the lignin component therein was exclusively targeted.On the other hand, in the present invention, in particular, the composition of lignin and hemicellulose was significantly different from that of wood. Focusing on valve effluents that take family plants into consideration, we found that such pulp effluents were extremely effective as a raw material for adhesives.

 The present inventor has surprisingly found that a pulp waste liquor of a grass plant can be used to produce a board product having a certain degree of strength even if it is directly used as an adhesive for a board such as a particle board. As a result of intensive studies, the adhesive having good strength properties was obtained by reacting the pulp waste liquor with phenols and formaldehyde under appropriate conditions.

 That is, the adhesive of the present invention is an adhesive obtained by reacting pulp waste liquor with phenol X and formaldehyde, and 30% by weight or more of the non-volatile content of the adhesive is derived from grass pulp waste liquor. It is characterized by the following.

 Further, the present invention provides a method of forming a board by adding and mixing an adhesive containing the above-mentioned adhesive or a component derived from the waste liquid of grass pulp to 30% by weight or more to a small piece of lignocellulosic material, and applying heat and pressure. It also covers lignocellulosic boards, such as characteristic board and fiber board.

The valve waste liquid used in the adhesive of the present invention is a so-called black liquor discharged in the valve digestion step, and is composed of hemicellulose, lignin or a decomposition product or modification thereof and a digestion catalyst. Is a waste liquid containing The pulp waste liquid is It is preferable to use only the waste liquid of the gramineous bulb, but it is also possible to use a mixture of waste liquid other than the gramineous plant such as wood.

 As the above-mentioned gramineous plants, any kind of gramineous plants such as bamboo, rice straw, wheat straw, bagasse (sugar cane pulp), ash, corn, coriander, etc. can be used, but especially bamboo, rice straw, wheat-based pulp. The use of waste liquid is preferred.

 Examples of the above pulp waste liquid include so-called chemical pulping methods such as the Kraft method, the sulfurous acid method, and the soda method, semi-chemical valve forming methods, thermomechanical pulping methods, organic solvent methods, etc. The waste liquid in any pulping method that discharges the denatured product can be used, but it is preferable to use the one obtained by alkaline conditions, particularly the one obtained by the soda method or the craft method. Conventionally, it is said that hemicellulose is decomposed into hydroxy acid in alkaline cooking, and it is expected that there is a limit to using the waste liquid of Al-Chili cooking as it is as an adhesive. It is noteworthy that the waste liquid of Arikuri cooking is preferably used.

 In the present invention, all plant-derived components in the valve waste liquid serve as active ingredients for adhesive production, and when the valve waste liquid is alkaline, the alkali component serves as a reaction catalyst. Therefore, it is not necessary to remove specific components in the valve waste liquid. However, it is preferable to remove the microfissure of the valve mixed in the waste liquid. Pulp waste liquid is usually about 20% to 50% in degree. It is used after being dehydrated and concentrated.

 As phenols, all phenols such as phenol, cresol, xylenol, bisphenol, bisphenol: t-norl F and resorcinol can be used, but from the viewpoint of performance and cost, use of phenol is preferred. Particularly preferably, the amount used is preferably 100% by weight or less, more preferably 5 to 60% by weight, based on the nonvolatile content of the pulp waste liquor. The amount used may exceed 100% by weight, but it will only increase the cost and cannot improve the physical properties.

 As formaldehyde, all formaldehydes such as formalin, paraformaldehyde and polyoxymethylene can be used. The use amount is preferably in the range of 1.2 to 5.0, more preferably 1.8 in terms of the molar ratio to the phenol monomer. A range of -3.5 is particularly preferred.

Also, other aldehydes such as acetoaldehyde, furfural, benzua 4 It is possible to use aldehyde, glyoxal, etc. in place of formaldehyde in a molar number that does not exceed the amount of formaldehyde.

 The adhesive of the present invention is preferably one in which the pulp waste liquor is reacted with phenols and formaldehyde under the conditions of pH 9 or more, particularly pH 10 or more. As the catalyst, any alkali catalyst satisfying such PH conditions can be used, including oxides or hydroxides of alkali metals and alkaline earth metals. However, if the pulp waste liquid used is an alkaline one such as the Kraft method or the soda method, it is not necessary to add the above-mentioned catalyst, which is advantageous.

 The adhesive of the present invention is a reaction product of the above-mentioned valve waste liquid, phenols and formaldehyde, and contains at least 30% by weight or more, preferably 50% by weight, of a component derived from grassy valve waste liquid in non-volatile components. %, Particularly preferably 60 to 95% by weight. Those containing less than 30% by weight of the components derived from the vegetation waste liquid of the gramineous plant cannot achieve the object of the present invention. The content is used in the production of the adhesive with respect to the non-volatile content of the adhesive. The weight percentage of the non-volatile content of the polished grass valve waste liquid. The adhesive of the present invention has a structure in which a pulp waste liquid component and a polymer of phenol X and formaldehyde are added with a methylol group.If possible, the pulp waste liquid component and the phenol monomer are alternately polymerized to form a methylol group. A structure with a well-balanced addition is preferred. As an unfavorable structure, a large amount of polycondensate consisting of c-nol and formaldehyde alone is mixed, and a large amount of polycondensate consisting only of valve waste liquid components and formaldehyde is mixed. These include: I: reacting phenol and formaldehyde with the polycondensation to a sufficient extent and then reacting the valve effluent, or reacting the pulp effluent with formaldehyde. F: I: It is obtained by reacting with nol.

The adhesive having the above preferred structure may be obtained by reacting a reaction product with a valve waste liquid after obtaining a specific reaction product from phenols and formaldehyde, or by mixing a valve waste liquid with a phenol: >>: phenols and formaldehyde. And at the same time under specific conditions. In particular, an adhesive obtained by obtaining a specific reaction product from phenols and formaldehyde and then reacting the reaction product with a valve waste liquid has the most preferable structure. After obtaining a specific reaction product from the above phenols and formaldehyde, The adhesive obtained by reacting the product with the valve waste liquid is as follows. First, the specific reaction product has a weight-average molecular weight of 120 to 500, preferably 150 to 300, and a content of a methylol derivative of a phenol monomer of 20% or more. Preferably, it is a reaction product of not less than 40% of phenol; In the methylol body of the phenol monomer, monomethylol, dimethylol, trimethylol having a certain amount of trimethylol and then dimethylol are preferably as high as possible. Such a reaction product has, for example, a molar ratio of formaldehyde to phenol monomer of 1.8 to 3.5, an alkali metal to phenol monomer of 0.1 to 0.5, and a reaction temperature of 50 to 80. For 30 minutes to 2 hours. This specific reaction product is added to the valve waste liquid and reacted at 50 to 95 temperatures for 20 minutes to 5 hours.

 The adhesive obtained by simultaneously reacting the above-mentioned valve waste liquid with phenols and formaldehyde under specific conditions is as follows: That is, the pulp waste liquid concentrate contains phenols and formaldehyde. , And firstly react at 40 to 85 for 20 minutes to 2 hours, preferably for 45 to 75 at 30 minutes to 1 hour, and then at 50 to 95 at 30 to 8 hours. Let it. The first reaction preferentially forms the methylol form of phenolic monomer.

 When the adhesive of the present invention is neutralized to PH57, it separates into a tetrahydrofuran-soluble component and an insoluble component, and the weight-average molecular weight of the soluble component is preferably 500 or more, and is preferably from 800 to 2,000. Is more preferred. Those having an overlapping average molecular weight of less than 500 have low strength performance, and the desired weight average molecular weight is adjusted mainly by the reaction time. The adhesive of the present invention is usually used in the form of a liquid, particularly an aqueous solution or a suspension of water, but can be used in a powder form by dewatering and drying.

The adhesive of the present invention is cured by a cross-linking reaction of a methylol group and is usually thermosetting, preferably by heat treatment at a temperature of at least 150, more preferably at a temperature of from 180 to 210. , Curing is achieved. However, it is not necessarily limited to thermosetting. For example, the adhesive can be cured at room temperature by allowing an alkali metal to exist in an amount of 0.5 mol or more based on the mononuclear phenol, and mixing an organic acid ester at the time of use. The adhesive of the present invention can be used in all applications where a conventional thermosetting resin adhesive or binder is used, but is particularly useful as an adhesive for wood such as particle board, fiber board, and plywood. Demonstrate excellent performance,

 The adhesive of the present invention may be used in combination with other agents such as a water-soluble agent, a release agent, and a flame retardant. Further, the adhesive of the present invention can be used in combination with other synthetic resin adhesives such as urea resin and melamine resin.

 Next, the board of the present invention will be described.

 The board in the present invention is a board, such as a particle board or a fiber board, formed by mixing small pieces of a lignocellulosic substance such as wood with an adhesive, heating and pressurizing.

 The board of the present invention comprises a small piece of a lignocell mouth substance containing an adhesive containing 30% by weight or more, preferably 50% by weight or more, and particularly preferably 60% by weight or more of a component derived from a pulp waste liquid of a grass family. The non-volatile components are added and mixed at a ratio of 0.5 to 40% base, and heated and pressurized.

 As the above-mentioned adhesive, it is preferable to use the above-mentioned adhesive of the present invention. However, the waste liquid of a grass valve valve itself may be used. Some wood adhesives may be used in combination.

 By adding and mixing the adhesive of the present invention to a small piece of lignocellulose material, heating and pressing to form a plate, a practical lignocellulose board such as a particle board or a fiber board can be produced with good performance. At this time, the adhesive of the present invention may be added at a ratio of about 0.5 to 40% by weight in terms of nonvolatile content to small pieces of the lignocellulose substance, and usually at a rate of 1 to 20% by weight. It is preferably added. Such a board of the present invention has a mechanical strength equal to or higher than that of a board product using a conventional wood adhesive.

 In the production of the lignocellulosic board of the present invention, the conditions for heating and pressing may be in accordance with a conventional method. Further, additives such as a water solution, a release agent, a preservative, and the like may be used, and these may be previously added to and mixed with the adhesive, or may be added separately from the adhesive during board production. .

The reason why the adhesive of the present invention exhibits excellent performance is not necessarily clear, The composition of hemicellulose and lignin specific to gramineous plants can be mentioned. ・ Gramineous plants contain a large amount of xylan as hemicellulose.Xylane hydrolyzes, and mostly xylose is hydrolyzed to furfural. Furfural is a substance used as an aldehyde source for furan and phenolic resins, but is industrially used as a suitable raw material for plants of the family Poaceae such as maize transaxles, wheat straw, fir husks, and bacass. In alkaline valve digestion, the ability of most of the aldehyde components derived from hemicellulose to be converted to hydroxyacid by the beating reaction ί, while xylan shows strong resistance to the beating reaction It has been known. One reason that the adhesive of the present invention exhibits excellent performance is considered to be that xylan or a decomposition product thereof is effectively used as an aldehyde source.

 Lignin of grasses has a special structure represented by the formula (1) (formula (2) is a lignin that is often contained in coniferous trees, and formula (3) is a lignin that is frequently contained in broad-leaved trees).

イネ科植物のリグニンはフ： cノール骨格の左右のオルソ位にメ トキシ基が無いため、 ホルムアルデヒ ドが付加反応しやすく 、 また、 フ： tノールとの共縮合によるオリゴ マーの形成が容易であると考えられる.

Lignin of grasses has no methoxy group at the right and left ortho-positions of the phenolic skeleton, so that formaldehyde can easily undergo an addition reaction, and oligomers can be easily formed by co-condensation with phenolic phenol. It is believed that there is.

In the adhesive of the present invention, the reason why a pulp waste liquid and a methylol derivative of phenol are preferred is exemplified by the most preferred trimethylol phenol. The trimethylol phenol represented by the formula (4): 1: 1: The dehydration and condensation of the pulp waste component with the pulp waste liquid component tend to form an oligomer in which the phenol monomer represented by the formula (5) and the pulp waste liquid component are alternately polymerized with a methylene group interposed therebetween. Moreover, the methylol necessary for the reaction The ru body remains in the skeleton. In this way, a resin composition of a type that cures by a cross-linking reaction of a methylol group is formed by efficiently using a small amount of phenol and formaldehyde.

 However, R and R 'indicate a valve waste liquid component. BEST MODE FOR CARRYING OUT THE INVENTION

 Next, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.

 The molecular weight distribution charts and weight average molecular weights in these Examples and Comparative Examples were obtained by neutralizing a sample with FH5-7 with formic acid and then dissolving the THF (tetrahydrofuran) soluble matter by gel permeation chromatography (manufactured by Shimadzu Corporation). The column was measured using Shimadzu LC Column GPC-801 1500) and the carrier: THF, 1 cc / ai detector, UV. In the present invention, the content of the methylol form of the t-nol monomer is as follows: It was expressed as area% of molecular S distribution chart.

Examples 1 to 5

In a reaction vessel equipped with a cooler and a stirrer, add a concentrated solution Y of bamboo pulp waste liquor with a non-deterrent content 5 Offl amount% and pH 3 The adhesives were added and allowed to react for a predetermined period of time to produce adhesives A to E. Table 1 shows the reaction times and the reaction times of i: nol and formaldehyde. Furthermore, weight average molecular weight, The calculated values of the components derived from grass pulp in the nonvolatile components of the adhesive are also shown in Table 1. Table 1

 2) The molar ratio of formaldehyde to phenol

 3) Weight percent of non-propelled waste of grass pulp liquor in non-volatile adhesive

 Example 6 8 (Calculation of% of non-adherence of used valve waste liquid to non-volatile adhesive)

 Add the concentrated liquid of each grass pulp waste liquid shown in Table 2, add 150% by weight of phenol and phenol to phenol in a molar ratio of 3 to formaldehyde with respect to the non-volatile content of the valve waste liquid. After reacting for 4 hours, adhesives F to H were produced. The weight average molecular weights of these adhesives are also shown in Table 2.

Comparative Example 13 Adhesive IK was produced in the same manner as in Examples -g except that a pulp waste liquid other than 13 Gramineous plants was used. The fi content average molecular weights of these adhesives are also shown in Table 2.

 Table 2

Type of adhesive Type of pulp waste liquid Weight average molecular weight Example 6 F Bamboo craft method 1260

 '' 7G wheat soda method 1 80

 '8 H rice soda method 1090

 Comparative example 1 I Manila hemp soda method 1320

 '' 2 J Flax soda method 1430

'' 3K softwood craft method 1 130 Comparative Example 4

 In a reaction vessel equipped with a condenser and stirrer, formalin in a molar ratio of 2 to phenol and phenol, and sodium hydroxide in a molar ratio of 0.33 to phenol were charged, and reacted at 80 to 3.5 hours. A phenol aldehyde resin adhesive Z was produced. After the adhesive Z was neutralized to pH 5 to 7 with formic acid, the weight-average molecular weight of the THF-soluble component was measured in the same manner as in Example 1. 950. This adhesive Z corresponds to a standard board adhesive.

Examples 9-1 1

 In a reaction vessel equipped with a cooler and a stirrer, 70 mol of formalin corresponding to a molar ratio of 3 to phenol and phenol and 0.333 of sodium hydroxide to phenol with a molar ratio of 0.33 were added. The reaction was carried out for 30 minutes to produce a reaction product X of phenol and formaldehyde. FIG. 1 shows a molecular weight distribution chart of the reaction product X. The content of the methylol form of the phenol monomer in the reaction product X was o-methylolphenol 8%, p-methylolphenol + 2,6-dimethylol 8%, 2.4-dimethylolphenol 11%, Trimetic mouth: 29% for t-nor, a total of 56%. In addition, the weight average molecular weight was 172.

 Then, the reaction product X was added to the same concentrated solution of grass valve waste liquid as used in Examples 4 to 6 so that the ratio of phenol X in the reaction product X to the nonvolatile matter of the valve waste liquid became 15% by weight. And reacted for 2 hours at 70 to produce adhesives L to N. Table 3 shows the weight average molecular weights. Fig. 2 shows the molecular weight distribution chart of the rice valve waste liquid adhesive of the adhesive N.

 Table 3 Types of adhesives Types of valve waste liquid Weight average molecular weight Example 9 L Take Craft Method 1 1 9 0

 * 1 0 M wheat as soda method 1 4 2 0

'1 1 N Rice ¾Soda method 1 0 4 0 [Strength test of barticle board]

 The following Examples 12 to 25 and Comparative Examples 5 to 8 show the strength performance of the adhesive of the present invention as a particle board adhesive, and the particles obtained by the method for producing a lignocellulosic board of the present invention. This is an examination of the strength performance of the board.

 The particle board is made from absolutely dry flakes obtained by cutting the building demolition material using a knife ring flaker (pa 11 man) with a blade of 0.5 mm. After applying and adding a 10% by weight adhesive as a non-volatile content using a spray gun, it is hand-dispersed in a 22 cm square forming box, mat formed, and a lcm size spacer is used (target specific gravity 0). 7 gZ c πί), pressure was 50 kgf Zcnf at 200 ° C for 15 minutes by zono heating.

 In addition, three test pieces obtained by cutting the molded product into a size of 5 × 20 cm were measured in accordance with JIS A59085.5.

Examples 12 to 22

 Particle boards were manufactured using the adhesives A to H and L to N of the present invention manufactured in Examples 1 to 11, and the bending strength was measured. The results are shown in Table 4.

Comparative school 5-8

 Particle boards were manufactured using the adhesives I to K and Ζ manufactured in Comparative Examples 1 to 3, and the bending strength was measured. The results are shown in Table 4.

Example 23

 Using the bamboo valve waste liquid concentrate as an adhesive, a particle board was manufactured and the bending strength was measured. The results are shown in Table 4,

Examples 24 and 25

The bamboo valve waste liquid concentrate Υ and the above-mentioned phenol aldehyde resin adhesive 混合 are mixed at a ratio such that the non-volatile content of the bamboo pulp waste liquid becomes 40% by weight, and the adhesive 0 is mixed. % To produce adhesive 剤. Particle boards were manufactured using these adhesives, and the bending strength was measured. The results are shown in Table 4, Table 4

 2) Amount of components derived from pulp waste liquid in adhesive non-suppressed components

From the above Examples R and Comparative Examples, the following can be seen.

 (1) Even if the component derived from the pulp waste liquor in the non-volatile content of the adhesive is 30% or more, especially 50% or more, and even 80% or more, the phenol alcohol resin adhesive Demonstrates strength performance equal to or higher than

 (2) The weight-average molecule 1 is 120-500, and 20% or more of the non-inhibited portion is phenol: The reaction product of phenol X, which is a methylol form of monomer, with formaldehyde The adhesive reacting to the waste liquid exhibits better strength performance.

 (3) The board can be manufactured using only the pulp waste liquid of grasses as an adhesive.

 (4) Better strength performance is achieved when the molar ratio of formaldehyde to phenol is in the range of 1.8 to 3.5.

 (5) An adhesive having a weight average molecular weight of 500 or more exhibits good strength performance.

Claims

INDUSTRIAL APPLICABILITY The adhesive and board of the present invention have the following effects and are therefore of industrial value. (1) The adhesive of the present invention exhibits excellent strength performance equal to or higher than that of the conventional phenolic aldehyde adhesive. (2) The adhesive of the present invention is extremely inexpensive in raw material cost and easy. (3) The adhesive of the present invention exhibits particularly excellent strength performance as an adhesive for lignocellulosic substances such as verticle board, fiber board, plywood and the like. (4) The adhesive of the present invention can be used in the same manner as a conventional thermosetting resin adhesive. (5) The adhesive of the present invention solves the problem of environmental pollution due to valve waste liquid (6) In addition, resources can be used effectively (7) The board of the present invention has excellent mechanical strength. (8) The board of the present invention is economically extremely advantageous because the lignocellulosic board can be manufactured with extremely low raw material costs. The same production equipment and the same manufacturing process can be applied as for the production of lignocellulosic boards that use the same adhesive. (9) The board of the present invention uses much more formaldehyde than conventional wood adhesives. Fig. 1 shows the molecular weight distribution chart of reaction product X. In Fig. 1, beak 1 is o-methylolphenol, peak 2 is p-methylol Phenol and 2,6-dimethylolphenol, beak 3 is 2,4-dimethylolphenol: tonol, beak 4 is trimethylolphenol Figure 2 shows a molecular weight distribution chart of a rice-based valve adhesive. The scope of the claims 1. Valve waste fluid and adhesive: An adhesive consisting of a reaction product of c-noles and formaldehyde, characterized in that at least 30% by weight of non-volatile components are derived from grass pulp waste fluid.  2. The adhesive according to claim 1, wherein 50 to 95% by weight of the non-volatile components is a component derived from a pulp waste liquid.  3. The adhesive according to claim 1 or 2, wherein the grass pulp waste liquor has been digested under Alkari conditions.  4. A product obtained by reacting a valve waste liquid with furls and formaldehyde under alkaline conditions of pH 9 or more, and the molar ratio of formaldehyde to phenols to phenol monomers relative to phenols The adhesive according to any one of claims 1 to 3, wherein the adhesive is used in a range of 1.2 to 5.0.  5. The adhesive according to claim 4, wherein the molar ratio of formaldehyde to I: nol monomer is 1.8 to 3.5.  6. The weight average molecular weight is 120 to 500, and at least 20% of the non-volatile content is a methylol derivative of a phenol monomer. I: Claims in which the reaction product of phenols and formaldehyde is reacted with pulp waste liquid. Item 4 or 5 adhesive.  7. The adhesive according to claim 6, wherein a weight average molecular weight of a reaction product of the phenol and formaldehyde is 150 to 300, and 40% or more of the non-volatile content is a methylol body of a phenol monomer. .  8.The adhesive according to any one of claims 1 to 7, wherein the weight average molecular weight of the tetrahydrofuran-soluble component after neutralizing the adhesive to pH 5 to 7 is 500 to 2000.  9. To a small piece of lignocellulosic material, add an adhesive containing 30% by weight or more of the component derived from grassy pulp waste liquor at a ratio of 0.5 to 40 overlay% of non-volatile content, mix by heating and pressurize. A lignocellulosic pode characterized by being laminated.  10. The method according to claim 9, wherein the component derived from the waste liquid of the grass pulp is 50% by weight or more. 11. The gramineous valve waste liquid has been digested under Alkyri conditions. 9 or 10 boards.  2. The above adhesive is the product of the reaction of the valve waste liquid with phenols and formaldehyde under alkaline conditions of pH 9 or higher, and the formaldehyde with respect to the phenolic monomer is responsive to phenol X The board according to any one of claims 9 to 11, wherein the board is used in a molar ratio of 1.2 to 5.0.  3. The board according to claim 12, wherein the molar ratio of formaldehyde to C-monomer is 1.8 to 3.5.  4. The above adhesive reacts the reaction product of a phenol with formaldehyde, which has a weight average molecular weight of 120 to 500 and a non-volatile content of 20% or more is a methylol phenol monomer, with the valve waste liquid. 14. The board of claim 12 or claim 13 which is a product of said method.  5. Above: The reaction product of c-noles and formaldehyde has a weight average molecular weight of 150 to 300, and at least 40% of the non-volatile content is a methylol derivative of a phenol monomer, and the non-volatile content is at least 40%. 15. The board according to claim 14, wherein at least 40% of the board is a methylol derivative of a phenol monomer.  6. The board according to any one of claims 9 to 15, wherein the weight average molecular weight of the tetrahydrofuran-soluble component after neutralizing the adhesive to pH 5 to 7 is 500 to 2000.