CN1113947C - Adhesive and boards made by using the same - Google Patents

Abstract

The present invention provides an adhesive that uses pulp waste liquid, exhibits good strength properties, has a high proportion of components derived from pulp waste liquid, and is more economical than commercially available thermosetting resin adhesives. Also provided are lignocellulosic boards with good properties using such binders. This is a binder composed of a reaction product of pulp waste liquid, phenolic substances, and formaldehyde, wherein more than 30% by weight of non-volatile components are components derived from pulp waste liquid of rice plants. The adhesive is added and mixed into small pieces of lignocellulosic material, and heat and pressure can make practical lignocellulosic boards such as laminated boards and fiberboards. The non-volatile content of the adhesive is more than 30% by weight. Components from pulp waste liquor of rice plants.

Description

Adhesive and board using the same

technical field

The present invention relates to an adhesive using pulp waste liquid, and lignocellulosic board materials such as laminated boards and fiberboards using the adhesive.

Background technique

In fact, the raw materials of the pulp industry in Japan, Europe and the United States can only rely on wood. These countries have all experienced serious environmental pollution problems caused by pulp waste liquid. Taking this as an opportunity, research has been made on the use of pulp waste liquid as a part of the raw material for phenolic resin binders.

Most of these studies have used lignin isolated and refined from pulp waste liquor. For example, "Wood Industry 24, P84, Banjing et al. (1969)", Japanese Patent Publication No. 53-28462, Japanese Patent Publication No. 62-56193, Japanese Patent Publication No. 6-506967, Japanese Patent Publication No. 7-53858 wait. However, the cost of refining lignin is high. At present, the price of commercially available lignin is higher than that of urea and formaldehyde, which are raw materials for general wood adhesives, and almost the same as that of phenol and melamine. Moreover, lignin is a part of waste liquid, and only using lignin cannot fundamentally solve the problem of waste liquid treatment.

On the other hand, there are other reports on the utilization of pulp waste liquid (for example, Japanese Patent Publication No. 51-22497, Japanese Patent Publication No. 54-15798, and Japanese Patent Publication No. 60-22024). However, in order to obtain sufficient strength in Japanese Patent Publication No. Sho 54-15798 and Japanese Patent Publication No. Sho 60-22024, it is necessary to use a larger amount of phenol than pulp waste liquid components. In Japanese Patent Publication No. 51-22497, corresponding to 100 parts of sulfurous acid pulp waste liquid solid content, 50 to 100 parts of phenol are used. The manufacturing process is more complicated. In addition, from the perspective of cost, it is not as good as urea resin. agent and melamine resin adhesive.

The adhesive of the conventional method is not only complicated in the manufacturing process, but its strength is not as good as that of commercially available wood adhesives, and it is also unfavorable in terms of the cost of raw materials. Therefore, considering any or all of the above-mentioned reasons, it is impossible to achieve practical use. for the purpose of transformation.

On the other hand, China and Southeast Asian countries can not only use wood, but also use bamboo, rice straw, wheat straw, reed, flax, kenaf and other non-wood as raw materials for pulp production. However, the production of chemical pulp has increased sharply recently. The problem of environmental pollution caused by pulp waste liquid is also becoming more and more serious.

The object of the present invention is to use pulp waste liquor (black liquor), provide a binder with good strength, a higher proportion of pulp waste liquor components, and a cheaper price than commercially available thermosetting resin binders, and using The adhesive performs well on lignocellulosic boards.

disclosure of invention

In fact, only waste wood pulp was used in the previous method, and the lignin component in it was used as the special object. The present invention focuses on the study of the rice plants that are very different from wood in the composition of lignin and hemicellulose. It is found that it is extremely effective to use this waste liquid as a binder raw material.

Surprisingly, the inventors of the present invention were able to produce a board product with a certain strength even if the concentrated liquid of pulp waste liquid from rice plants was directly used as an adhesive for boards such as laminated boards. The result of the research is that, under appropriate conditions, the reaction of rice plant pulp waste liquid with phenols and formaldehyde can obtain adhesives with good strength characteristics.

That is to say, the adhesive of the present invention has the following characteristics. It is an adhesive obtained by reacting pulp waste liquid with phenols and formaldehyde, and more than 30% by weight of the non-volatile components of the adhesive come from rice plant pulp. waste liquid.

In addition, the present invention also includes lignocellulosic boards such as laminated boards and fiberboards, which are characterized in that small pieces of lignocellulosic substances are added and mixed into the above-mentioned binder or contain more than 30% by weight of waste pulp from rice plants The components of the adhesive are then heated and pressed into sheets.

The pulp waste liquid used in the binder of the present invention is discharged in the pulp cooking process, commonly known as black liquor, which is a waste liquid containing hemicellulose, lignin or their decomposition or denaturation products and a catalyst for cooking . The pulp waste liquid is preferably composed only of rice plant pulp waste liquid, but waste liquid mixed with a part of wood and other plants other than rice plant may also be used.

As the above-mentioned rice plant, all rice plants such as bamboo, rice straw, wheat straw, bagasse (sugar cane bagasse), reed, corn, sorghum can be used, and pulp waste liquid of bamboo, rice straw, and wheat straw is preferably used.

As the above-mentioned pulp waste liquid, so-called chemical pulping methods such as sulfate pulping method, sulfurous acid method, and alkali method, semichemical pulping method, thermomechanical pulping method, organic solvent method, etc. can be used to make hemicellulose, wood pulp, etc. All the waste liquids of the pulping process discharged from the pulp or their decomposition products or denatured products, but preferably the waste liquids obtained under alkaline conditions, especially the waste liquids obtained by the alkaline method and kraft pulping method. In the previous alkaline cooking operation, hemicellulose was decomposed into hydroxy acids, so that the direct use of alkaline cooking waste liquid as a binder was limited. In the present invention, it is better to use alkaline cooking waste liquid.

In the present invention, all the plant-derived components in the pulp waste liquid are effective components for preparing the adhesive, and when the pulp waste liquid is alkaline, the alkaline components act as reaction catalysts. Therefore, it is not necessary to remove specific components in pulp waste liquor. However, it is preferable to remove pulp microfibers mixed in the waste liquor. Pulp waste liquid is usually dehydrated and concentrated to a concentration of 20 to 50% before use.

As the phenols, all phenols such as phenol, cresol, xylenol, bisphenol A, bisphenol F, and resorcinol can be used, but it is particularly preferable to use phenol in terms of performance and cost. The amount of non-volatile components corresponding to the waste pulp of rice plants is preferably at most 100% by weight, particularly preferably 5 to 60% by weight. If the amount exceeds 100% by weight, it does not matter, but the cost increases and the physical properties cannot be improved.

As formaldehyde, all formaldehydes, such as formalin, paraformaldehyde, and polyoxymethylene, can be used. Corresponding to the phenolic monomer, the amount used is in the range of 1.2 to 5.0, particularly preferably in the range of 1.8 to 3.5, in terms of molar ratio.

In addition, other aldehydes, such as acetaldehyde, furfural, benzaldehyde, glyoxal, etc., can also be used instead of formaldehyde within the range where the number of moles does not exceed formaldehyde.

The binder of the present invention is prepared by reacting the above-mentioned pulp waste liquid with phenols and formaldehyde under an alkaline condition of preferably pH 9 or higher, most preferably pH 10 or higher. As the catalyst, all basic catalysts satisfying the above pH conditions including oxides or hydroxides of alkali metals and alkaline earth metals can be used. However, if the pulp waste liquid to be used is an alkaline substance produced by kraft pulping method, alkaline method, etc., it is not necessary to add the above-mentioned basic catalyst, which is better.

The binder of the present invention is the reaction product of the above-mentioned pulp waste liquid, phenols and formaldehyde, and the non-volatile component is at least 30% by weight, preferably more than 50% by weight. , it is particularly preferable that the content is within the range of 60 to 95% by weight. The object of the present invention cannot be achieved if the component derived from the rice pulp waste liquor is less than 30% by weight. In addition, this content represents the weight% of the non-volatile matter in the rice plant pulp waste liquid used when preparing this adhesive agent with respect to the non-volatile matter of an adhesive agent.

The binder of the present invention has a structure in which a methylol group is added to a polymer of pulp waste liquid components, phenols, and formaldehyde, and it is preferable that the pulp waste liquid components and phenolic monomers are mutually polymerized to add methylol groups in a well-balanced manner. base structure. Unfavorable structures include a structure in which a large amount of polycondensate of only phenols and formaldehyde is mixed, or a structure in which a polycondensate of only pulp waste liquid components and formaldehyde is mixed in a large amount, and these structures are formed after a sufficient polycondensation reaction of phenols and formaldehyde. It can be obtained by reacting pulp waste liquid, or reacting pulp waste liquid with formaldehyde and then reacting with phenols.

The above-mentioned binder with a better structure is obtained by reacting phenols and formaldehyde to obtain a specific reaction product, which is then reacted with pulp waste liquid, or pulp waste liquid, phenols and formaldehyde are reacted simultaneously under specific conditions And get. In particular, after obtaining a specific reaction product from phenols and formaldehyde, the adhesive obtained by reacting the reaction product with pulp waste liquor has the most ideal structure.

The binder obtained by obtaining a specific reaction product from phenols and formaldehyde and then reacting the reaction product with pulp waste liquid refers to the following. First, the specific reaction product mentioned above means that the weight average molecular weight is 120-500, preferably 150-300, and the content of the methylol body of the phenolic monomer is more than 20%, preferably 40%. The reaction product of the above phenols and formaldehyde. Although the methylol body of the phenolic monomer includes monomethylol, dimethylol, and trimethylol, the higher the content of trimethylol, followed by dimethylol, the better. For example, such a reaction product can be obtained when the molar ratio of formaldehyde to phenolic monomer is 1.8 to 3.5, the molar ratio of alkali metal to phenolic monomer is 0.1 to 0.5, the reaction temperature is 50 to 80°C, and the reaction time is 30 Minutes to 2 hours under the conditions of reaction. This specific reaction product is added to pulp waste liquid, and it reacts in the temperature range of 50-95 degreeC for 20 minutes - 5 hours.

In addition, the binder obtained by simultaneously reacting the above-mentioned pulp waste liquid, phenols, and formaldehyde under specific conditions refers to the following substances. That is to say, add phenols and formaldehyde to the concentrated liquid of pulp waste liquid, and initially react at a temperature of 40-85° C. for 20 minutes to 2 hours, preferably at a temperature of 45-75° C. for 30 minutes to 2 hours. 1 hour, then react at 50-95°C for 30 minutes-8 hours. Through the initial reaction, the hydroxymethyl form of the phenolic monomer is preferentially formed.

If the binder of the present invention is neutralized to pH 5-7, the binder is separated into components soluble in tetrahydrofuran and insoluble in tetrahydrofuran, and the weight average molecular weight of the soluble components is preferably between More than 500, preferably between 800 and 2000. If the weight-average molecular weight is 500 or less, the strength is low, and the desired weight-average molecular weight is obtained mainly by adjusting the reaction time.

The binder of the present invention can be used in a liquid state, especially in the state of an aqueous solution or a water suspension, and can also be used in a powder form after dehydration and drying.

The adhesive of the present invention is cured through the cross-linking reaction of methylol groups. Generally, the thermosetting property is preferably above 150° C., more preferably through heat treatment at a temperature of 180-210° C. to achieve the purpose of curing. However, it is not necessarily limited to thermosetting. For example, in the adhesive, 0.5 mole or more of alkali metal is present corresponding to the phenolic monomer, and it can be cured at room temperature when mixed with an organic acid ester during use.

The adhesive of the present invention can be used in all fields where thermosetting resin adhesives or adhesives can be used in the past, especially as an adhesive for wood such as laminated boards, fiberboards, and plywoods, it can exert its good performance.

The adhesive of the present invention can also be used in combination with other agents such as waterproofing agents, mold release agents, and flame retardants. In addition, 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 sheet material of the present invention will be described.

The board of the present invention refers to a board formed by mixing adhesives into small pieces of lignocellulosic materials such as wood, and heating and pressing, represented by laminated boards and fiberboards.

The board of the present invention refers to the addition and mixing of the components from the rice plant pulp waste liquid in the small piece of lignocellulosic material, the content of which is more than 30% by weight, preferably more than 50% by weight, and particularly preferably 60% by weight. % or more of the binder, so that the proportion of non-volatile components in it reaches 0.5 to 40% by weight, and the plate is formed by heating and pressing.

As the above-mentioned binder, it is preferable to use the above-mentioned binder of the present invention, and it is also possible to use waste liquid of rice plant pulp. Furthermore, some other wood adhesives may be used in combination.

Adding and mixing the adhesive of the present invention into small pieces of lignocellulosic material, heating and pressing to form a board, can produce laminated boards, fiberboards and other practical lignocellulosic boards with good performance. The binder of the present invention is added to the small pieces of lignocellulosic material, in order to make the non-volatile content therein reach the level of 0.5-40% by weight, generally 1-20% by weight is preferably added.

The board of the present invention has the same or better mechanical strength than board products using conventional wood adhesives.

In addition, when manufacturing the lignocellulosic board material of this invention, the conditions of heating and pressurization etc. can be conventional. Additives such as waterproofing agent, release agent and preservative can also be used. These additives can be pre-added and mixed into the adhesive, or they can be added separately from the adhesive when manufacturing the board.

The reason for the good performance of the adhesive of the present invention is not clear at present, but it may be due to the hemicellulose and lignin components unique to rice plants.

Rice plants contain a large amount of xylan as hemicellulose, and most of the xylan is converted into furfural through xylose after hydrolysis. Furfural can be used as the aldehyde source of furan resin and phenolic resin. Industrially, corn cobs, wheat straw, rice husks, bagasse and other rice plants are used as good raw materials. When alkaline pulp cooking is performed, most of the aldehyde components from hemicellulose are converted to hydroxyacids by the dehulling reaction, to which xylan shows strong resistance. One of the reasons why the binder of the present invention exhibits good performance is that xylan or its decomposition product is effectively utilized as an aldehyde source.

由于稻科植物的木质素在酚骨架左右的邻位没有甲氧基，所以能够很容易地进行甲醛的加成反应，而且，通过与酚的共缩合能够容易地形成低聚物。In addition, the lignin of rice plants has a special structure represented by the formula (1) (the formula (2) is the lignin that is mostly contained in coniferous trees, and the formula (3) is the lignin that is mostly contained in broad-leaved trees)

Since the lignin of rice plants does not have a methoxy group in the ortho position to the left and right of the phenol skeleton, the addition reaction of formaldehyde can easily proceed, and furthermore, an oligomer can be easily formed by co-condensation with phenol.

Among the binders of the present invention, the reason why it is preferable to react the pulp waste liquid and the methylol form of the phenolic substance will be described by taking trimethylol phenol as an example. The trimethylol phenol represented by the formula (4) is dehydrated and condensed with the pulp waste liquid component, and the phenolic monomer represented by the formula (5) and the pulp waste liquid component easily form oligomers which are mutually polymerized through methylene groups. However, the hydroxymethyl form necessary for the crosslinking reaction remains in the phenolic skeleton. In this way, a small amount of phenol and formaldehyde can be effectively utilized to form a curable resin composition through the crosslinking reaction of the methylol groups.

Wherein, R, R ¹ represent pulp waste liquor components.

The best state to implement the invention

Hereinafter, the present invention will be described in more detail through examples, but the present invention is not limited to these examples.

In the embodiment and the comparative example, the pH value of the sample is adjusted to 5～7 with formic acid, then the gel filtration chromatograph produced by Shimadzu (column is シマズ LC column GPC-801 1500) in the carrier is THF1cc/ Under the condition of 1 min, the molecular weight distribution and weight average molecular weight of THF (tetrahydrofuran) soluble components were measured by detector. In the present invention, the content of the methylol body of the phenolic monomer is represented by the area % of the molecular weight distribution diagram.

Embodiment 1-5

In the reaction vessel equipped with condenser and stirrer, add the concentrated liquid Y of the bamboo pulp waste liquid obtained by kraft pulping method with a non-volatile content of 50% by weight and a pH value of 13, and then add a specified amount of phenol and a specified A certain amount of formaldehyde was reacted at 70°C to prepare Adhesives A~E. The dosage and reaction time of phenol and formaldehyde are shown in Table 1. The weight-average molecular weight and the calculated value of the non-volatile components of the binder derived from the rice plant pulp waste liquid are also shown in Table 1.

Table 1 Example Types of Adhesives manufacturing conditions Adhesive properties Phenols1) F/P2) Response time (hr.) Weight average molecular weight Components from waste liquid3) 1 A 100 2.2 3.5 1350 40 2 B 100 2.2 1.5 680 40 3 C 40 2.5 2.5 1349 56 4 D. 20 3.0 3 1180 75 5 E. 20 4.0 2 1190 72

1) % by weight of phenols corresponding to pulp waste liquor and non-volatile components

2) The molar ratio of formaldehyde to phenols

3) % by weight of the non-volatile components of the rice pulp waste liquid in the binder non-volatile components

(Calculated value of % by weight of non-volatile components of used pulp waste liquor corresponding to binder non-volatile components)

Embodiment 6-8

Get the concentrated solution of various rice plant pulp waste liquids shown in table 2, corresponding to the non-volatile components of paper pulp waste liquid, add 150% by weight phenols and the formaldehyde that the mol ratio to phenols is 3 therein, at 70 After reacting at ℃ for 4 hours, adhesives F to H were prepared. The weight average molecular weights of these binders are shown in Table 2.

Comparative example 1-3

Adhesives I to K were prepared in the same manner as in Examples 6 to 8 except for using pulp waste liquor from rice plants. The weight average molecular weights of these binders are also shown in Table 2.

Table 2 Types of Adhesives Types of pulp waste Weight average molecular weight Example 6 f Bamboo Kraft Pulping 1260 Example 7 G Straw soda method 1480 Example 8 h Rice straw alkaline method 1090 Comparative example 1 I Manila Canine Law 1320 Comparative example 2 J linolenic acid 1430 Comparative example 3 K Conifer kraft pulping 1130

Comparative example 4

Add phenolic substances, formalin with a molar ratio of 2 to phenolic substances, and sodium hydroxide with a molar ratio of 0.33 to phenolic substances in a reaction vessel equipped with a condenser and a stirrer, and react at 80°C for 3.5 Hours, the phenolic resin binder Z was prepared. Neutralize binder Z with formic acid, after its pH value is adjusted to 5～7, the weight-average molecular weight of the THF-soluble component that measures with the same method as embodiment 1 is 950, and this binder Z Equivalent to standard sheet adhesives.

Examples 9-11

Add phenolic substances, formalin with a molar ratio of 3 to phenolic substances, and sodium hydroxide with a molar ratio of 0.33 to phenolic substances in a reaction vessel equipped with a condenser and a stirrer, and react at 70°C for 30 Minutes, the reaction product X of phenolic substance and formaldehyde is obtained. The molecular weight distribution diagram of the reaction product X is shown in FIG. 1 . The methylol body content of the phenolic monomer in the reaction product X is o-hydroxymethylphenol 8%, p-hydroxymethylphenol+2,6-dimethylolphenol 8%, 2,4-dimethylolphenol 11% of phenol, 29% of trimethylolphenol, 56% in total. In addition, the weight average molecular weight was 172.

Then, the reaction product X was added to the concentrate of the same rice pulp waste liquid used in Examples 4 to 6, and the ratio of phenolic substances in the reaction product X corresponding to the non-volatile components of the pulp waste liquid was 15 % by weight, reacted at 70°C for 2 hours to prepare adhesives L-N. Its weight average molecular weight is shown in Table 3. In addition, the molecular weight distribution diagram of the rice straw pulp waste liquid binder of the binder N is shown in FIG. 2 .

table 3 Types of Adhesives Types of pulp waste Weight average molecular weight Example 9 L Bamboo Kraft Pulping 1190 Example 10 m Straw soda method 1420 Example 11 N Rice straw alkaline method 1040

[Strength test of laminated board]

The following Examples 12 to 25 and Comparative Examples 5 to 8 were conducted on the strength of the adhesive of the present invention as an adhesive for laminates and the strength of laminates produced by the method for producing lignocellulosic boards of the present invention. determined.

For the laminated board, the building disintegration material was cut into 0.5mm absolutely dry thin slices with the blade of a circular blade (Pallman), and 340 g of the thin slices were coated with 10% by weight of adhesive as a non-volatile component with a sprayer. , put it into a 22cm square forming box for molding, use a 1cm separator (target specific gravity is 0.7g/cm ² ), and heat for 15 minutes at a pressure of 50kgf/cm ² and a temperature of 20°C.

In addition, the molded product was cut into 5×20cm test pieces, and three test pieces were tested according to JIS A 5908 5.5.

Examples 12-22

Using the adhesives A to H and L to N of the present invention prepared in Examples 1 to 11, laminated jade boards were prepared, and the bending strength thereof was measured. The test results are shown in Table 4.

Comparative example 5-8

Using the adhesives I-K and Z prepared in Comparative Examples 1-3, laminated boards were prepared, and their flexural strengths were measured. The test results are shown in Table 4.

Example 23

Using the aforementioned bamboo pulp waste liquid concentrate Y as an adhesive, a laminate was prepared, and its flexural strength was measured. The test results are shown in Table 4.

Example 24, 25

Mix the aforementioned bamboo pulp waste liquid concentrate Y and the aforementioned phenolic resin binder Z so that the non-volatile components of the bamboo pulp waste liquid therein account for 40% by weight to obtain a binder O; make the bamboo pulp waste liquid non-volatile components therein Occupying 60% by weight, Adhesive P was prepared. Laminates were prepared using these adhesives, and their flexural strength was measured. The test results are shown in Table 4.

Table 4 Types of Adhesives Types of waste liquid Adhesive properties The physical properties of the board Phenols1) Waste liquid composition 2) Specific gravity (g/cm ² ) Bending strength (kgf/cm ² ) Example 12 A bamboo 100 40 0.76 214 Example 13 B bamboo 100 40 0.76 143 Example 14 C bamboo 40 56 0.76 226 Example 15 D. bamboo 20 75 0.75 198 Example 16 E. bamboo 20 72 0.75 146 Example 17 f bamboo 15 80 0.75 173 Example 18 G wheat straw 15 80 0.76 158 Example 19 h rice straw 15 80 0.77 148 Example 20 L bamboo 15 80 0.75 227 Example 21 m wheat straw 15 80 0.76 211 Example 22 N rice straw 15 80 0.77 189 Example 23 Y bamboo 0 100 0.77 109 Example 24 o bamboo 96 40 0.75 168 Example 25 P bamboo 43 60 0.76 159 Comparative Example 5 I Manila hemp 15 80 0.73 41 Comparative example 6 J flax 15 80 0.76 52 Comparative Example 7 K conifer 15 80 0.72 32 Comparative Example 8 Z Phenolic resin adhesive 0.76 218

1) Corresponding to the components derived from pulp waste liquid in the binder, the components derived from phenolic substances %

2) Amount of components from pulp waste liquid in the non-volatile components of the binder

Can draw the following conclusions from above embodiment and comparative example:

(1) In the non-volatile components of the binder, the composition from the rice plant pulp waste liquid is more than 30%, even if it is more than 50%, or even more than 80%, it can also exert the same or better performance as the phenolic resin binder. Good strength properties.

(2) A binder obtained by reacting a reaction product of a phenolic substance with a weight-average molecular weight of 120 to 500 and 20% or more of the non-volatile content being a methylol body having a phenolic monomer and formaldehyde, and pulp waste liquid Can play a better strength performance.

(3) It is possible to manufacture boards even if only rice plant pulp waste liquid is used as a binder.

(4) If the molar ratio of formaldehyde to phenolic substances is in the range of 1.8 to 3.5, better strength properties can be exhibited.

(5) Adhesives with a weight average molecular weight above 500 can exhibit good strength properties.

Possibility of industrial use

The adhesive and the sheet material of the present invention have the following effects, and have certain application value in industry.

(1) The adhesive of the present invention can exhibit the same or better strength performance than the conventional phenolic resin adhesive.

(2) The raw material price of the adhesive of the present invention is very low, and it is easy to manufacture, so it is very advantageous economically.

(3) The adhesive of the present invention can exhibit particularly good strength performance as an adhesive for lignocellulosic materials such as laminated boards, fiberboards, and plywood.

(4) The adhesive of the present invention is suitable for use in the same manner as conventional thermosetting resin adhesives.

(5) The adhesive of the present invention solves the problem of environmental pollution caused by pulp waste liquid.

(6) It is also possible to efficiently use resources.

(7) The board of the present invention can be made into a lignocellulosic board with good mechanical strength.

(8) The board of the present invention can be made of lignocellulosic board from extremely cheap raw materials, so it is very economical.

(9) The production equipment and manufacturing process used for the production of the board of the present invention are the same as those used in the production of lignocellulosic boards using general binders.

(10) Compared with the conventional adhesives for wood, the plate of the present invention has very little amount of formaldehyde, so it is very safe to the human body.

A brief description of the graph

Fig. 1 shows a molecular weight distribution diagram of the reaction product X. Peak 1 in Figure 1 is o-hydroxymethylphenol, peak 2 is p-hydroxymethylphenol and 2,6-dimethylolphenol, peak 3 is 2,4-dimethylolphenol, and peak 4 is trihydroxymethylphenol methyl phenol.

Figure 2 shows the molecular weight distribution graph of rice straw pulp binder.

Claims (9)

1. a tackiness agent is characterized in that, is made up of the resultant of reaction of spent pulping liquor and aldehydes matter and formaldehyde, is the composition from paddy rice spent pulping liquor more than the 30 weight % of nonvolatile component.

2. tackiness agent as claimed in claim 1, its feature are that also the 50-95 weight % of nonvolatile component is the composition from paddy rice spent pulping liquor.

3. tackiness agent as claimed in claim 1 or 2, its feature are that also described paddy rice spent pulping liquor is the liquid of process boiling under alkaline condition.

4. tackiness agent as claimed in claim 1, its feature also are, are spent pulping liquor and aldehydes matter and the formaldehyde resultant of reaction under the alkaline condition more than the pH9, and formaldehyde to the mol ratio of phenolic monomers in the scope of 1.2-5.0.

5. tackiness agent as claimed in claim 4, its feature also be, described formaldehyde to the mol ratio of phenolic monomers in the scope of 1.8-3.5.

6. as claim 4 or 5 described tackiness agents, its feature also is, is getting for the aldehydes matter of the methylol body of phenolic monomers and the resultant of reaction and the spent pulping liquor reaction of formaldehyde more than 20% of 120-500, nonvolatile component by weight-average molecular weight.

7. tackiness agent as claimed in claim 6, its feature are that also the weight-average molecular weight of the resultant of reaction of described aldehydes matter and formaldehyde is 150-300, and nonvolatile component is the methylol body of phenolic monomers more than 40%.

8. tackiness agent as claimed in claim 1, its feature also be, the weight-average molecular weight that described tackiness agent is neutralized to the component that dissolves in tetrahydrofuran (THF) behind the pH5-7 is 500-2000.

9. a lignocellulose sheet material is characterized in that, adds each described tackiness agent among the claim 1-8 in small pieces lignocellulose material, makes nonvolatile component wherein reach 0.5-40 weight %, then heating and pressurizing and making.