JP2595308B2 - Lignin-phenol resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lignin-phenol resin composition and an adhesive containing the lignin-phenol resin composition as a main component.

More specifically, the present invention relates to a lignin material-
The present invention relates to a lignin-phenol resin composition containing a phenol compound-formaldehyde addition / condensation reaction product and having excellent curability, applicability and adhesive strength, and an adhesive containing the lignin-phenol resin composition as a main component.

[Problems to be Solved by the Prior Art and the Invention] In the pulp and paper industry, the cellulose component, which is a raw material for papermaking, is extracted from wood by a pulping method, and most of the remaining lignin component is recovered and consumed as fuel. Is the actual situation. For this reason, it is desired to develop a lignin component that is more expensive and more expensive. Explosion treatment of wood as pretreatment for wood chemical use of wood, and organosolv pulping method as a new pulping method, which is currently in a very potent research stage, but one key to the success of its practical use Is said to be in the development of high value-added uses of lignin.

The present invention is one of high-value-added methods of using these alkali lignin, explosive lignin, and waste lignin from organosolv pulping. Specifically, these lignin materials are used in water-soluble and adhesive resin compositions. What you want to do.

Water-soluble phenolic resin compositions (resole resin compositions) are widely used as wood adhesives that are required to have high durability and water resistance. One of the problems with such adhesives is that they require a high bonding temperature of 140 ° C. or higher, and in some cases 170 ° C., in order to cause sufficient curing during bonding. Therefore, unless the moisture content of the wood to be bonded is extremely reduced, a fatal problem called a puncture will occur due to heating during bonding. This problem places great restrictions on the bonding operation and results in extra operations. On the other hand, conventionally, development of an adhesive from biomass such as a lignin material or a lignocellulose material has been attempted, and some of the results have been put to practical use. A major problem in this case is that biomass-modified adhesives such as lignin-modified adhesives are inferior in reactivity and curability as compared with corresponding commercially available adhesives, and thus require more severe bonding conditions. Such bonding conditions reduce the efficiency of the industrial bonding operation and result in high energy consumption.

Also, many attempts have already been made on the preparation of a water-soluble phenolic resin adhesive using a lignin material, and in these attempts, many of those having performance as a water-resistant adhesive have been reported. As described above, these adhesives require severe bonding conditions such as a higher bonding temperature and a longer bonding time than ordinary water-soluble adhesives. For example, Sakai et al. (The 28th Symposium on Lignin Chemistry (1983)) reported that the amount of inorganic salts added and
A basic formaldehyde-based resin adhesive is prepared from a pre-treated product obtained by changing the treatment conditions. As a result of this research, pH: 2.0, phenol blend ratio (vs. 50% waste liquid):
0.33 to 0.50, temperature: 200 ° C, time: 120 minutes, formaldehyde is mixed with phenol-treated lysin material and dissolved to obtain resin under pH: 9.5 to 11.5, temperature: 80 to 90 ° C. Water-soluble lignin-phenolic resin adhesive has a useful performance as a water-resistant adhesive,
However, it has been found to require somewhat higher than normal bonding temperatures. Also, Abe et al. (Forestry Experiment Station Monthly Report, Vol.15, N
o.179,10 (1966)) is a caustic soda pretreatment (liquid ratio: 1/3,
NaOH addition rate: 20% to lignin, reaction condition: 140 ° C, 3 hours) 60 parts of the exposed kraft lignin, 40 parts of phenol and 42 parts of formaldehyde were blended, and these were co-condensed (80 ° C, 60 minutes) ) To prepare a resin having relatively good fluidity and thermosetting properties. However, in this preparation method, high-temperature, long-term alkali pretreatment is required, and in order to obtain a plywood having excellent adhesive performance using the obtained resin, conditions of relatively high temperature and long time are required. Problems such as the necessity of hot-pressure bonding are pointed out. It has also been pointed out that the addition of a small amount of a curing accelerator (resorcinol) is effective for improving the latter problem.

As described above, the conventional alkaline resol type phenol resin adhesive requires high temperature and long-time heat and pressure conditions for bonding, and the water content of veneer must be set low during use. have. Therefore, it can adhere under the same conditions as urea resin and melamine resin,
You will be interested in phenolic resins with adhesive properties that pass JAS special standards. That is, there is a proposition that the phenol resin adhesive is bonded under the same conditions as the amino resin adhesive, and various methods have been studied to solve the problem. One of them is to use a high-condensation resin adhesive in which the reaction rate of phenolic resin is improved, but this resin adhesive has drawbacks such as remarkably low storability. As another method, it has been attempted to obtain high-speed curing using an acid-curable phenol resin adhesive. In the case of the latter adhesive, it cures even at room temperature, but the pH of the adhesive needs to be 2 or less, and such a low pH causes deterioration of wood. It has been found that after several such trials and errors regarding the rapid curing of phenolic resins, phenol-melamine co-condensation resins can achieve the above object. That is, the phenol-melamine resin adhesive is
Achieved the intended purpose by being able to adhere under the same conditions as amino resins, and by being mixed with urea resin, achieving adhesive performance that meets any of the two JAS standards. And it has been put to practical use.

As described above, the characteristics of the lignin / phenol resin reported so far have both advantages and disadvantages, and have to be said to be inadequate overall. At the same time, the purpose of lowering the heat and pressure curing temperature of the water-soluble phenol resin adhesive to that of the amino resin has not been sufficiently achieved by the conventional lignin-phenol resin adhesive.

That is, the present invention has the following problems in the conventional lignin-phenol resin composition and adhesive: (a) The required adhesive curing temperature is higher than a desired temperature.

(B) The required adhesive curing time is longer than the desired time.

It is an object of the present invention to provide a resin composition and an adhesive capable of performing high-speed curing bonding at a relatively low temperature.

[Means for solving the problem]

The lignin-phenol resin composition of the present invention is a phenolized lignin-containing mixture obtained by reacting 100 parts by weight of a phenol compound with 10 to 150 parts by weight of a lignin material in the absence of a catalyst or an acidic catalyst. And 30 to 250 parts by weight of formaldehyde in the presence of a basic catalyst.

Further, another lignin-phenol resin composition of the present invention is a phenol obtained by reacting 100 parts by weight of a phenol compound with 10 to 150 parts by weight of a lignin material in the absence of a catalyst or in the presence of an acidic catalyst. Lignin-containing mixture and 30
To 250 parts by weight of formaldehyde, 100 parts by weight of an addition / condensation reaction product in the presence of a basic catalyst, and a resorcinol compound and at least one 1 to 50 selected from a resorcinol compound-formaldehyde precondensate Parts by weight.

Further, the lignin-phenol resin adhesive of the present invention,
It is characterized by containing each of the resin compositions as a main component.

In preparing the resin composition of the present invention, first, 100 parts by weight of a phenol compound and 10 to 150 parts by weight of a lignin material are reacted in the absence of a catalyst or in the presence of an acidic catalyst, thereby preliminarily causing phenolation. A lignin-containing mixture is prepared. This phenolized lignin-containing mixture, 30-250
A lignin-phenol resin composition is prepared by adding and condensing a part by weight of formaldehyde in the presence of a basic catalyst.

In order to prepare another lignin-phenol resin composition of the present invention, at least 100 parts by weight of the addition / condensation reaction product obtained in the same manner as above, at least one selected from a resorcinol compound and a resorcinol-formaldehyde precondensate. 1 to 50 parts by weight of one kind is mixed.

The phenol compound used in the present invention is phenol,
It can be selected from cresol, xylenol, alkylphenol, phenylphenol, resorcinol and the like.

The lignin material used in the present invention includes alkali lignin (eg, thio (kraft) lignin obtained by precipitation from kraft black liquor by neutralization with acid), explosive wood lignin (lignin extracted from explosive wood), and sorbolisis It can be selected from lignin by-produced in the pulping reaction.

The basic catalyst for addition / condensation reaction of formaldehyde used in the present invention includes at least one selected from caustic soda, potassium hydroxide, ammonia, organic amines, and hydroxides of zinc, calcium, magnesium and aluminum. Those containing one type can be used.

Further, the addition / condensation reaction between the phenolated lignin-containing mixture and formaldehyde is preferably performed at a temperature of 60 ° C to 150 ° C, and generally, the required reaction time is 30 to 360 ° C.
Minutes.

Reaction of lignin material with phenol (phenolysis)
In this case, various degrees of cleavage of the intramolecular bond of lignin and introduction of phenol into various degrees of the lignin side chain α-position, etc., thereby facilitating dissolution of the lignin material, and The performance and properties are excellent, and at the same time, the reactivity of lignin is increased to facilitate the subsequent reaction. As a result, properties such as physical properties and adhesiveness of the adhesive are improved.

In addition, sugars present as impurities in the lignin material are also hydrolyzed at the time of reaction with phenol to become reaction products such as oxymethylfurfural, which can enhance the performance of the adhesive.

The phenolated lignin-containing mixture contains phenolated lignin and impurities derived from the lignin material and products thereof.

In the present invention, the phenolization of the lignin material also proceeds by simply heating to 140-220 ° C without a catalyst. In addition, in order to facilitate the phenolization of the lignin material more easily, mineral acids such as hydrochloric acid, sulfuric acid and nitric acid,
Organic acids of formic acid, acetic acid, oxalic acid, benzene sulfonic acid, toluene sulfonic acid, phenol sulfonic acid and trifluoroacetic acid sugar, and aluminum chloride, zinc chloride,
And a heat treatment at a temperature of 150 ° C. or less in the presence of at least one acidic catalyst selected from Lewis acids such as boron trifluoride.

If the lignin material is phenolized in the presence of an acid catalyst, the acid catalyst is optionally neutralized. However, in the subsequent addition / condensation reaction using formaldehyde, a basic catalyst composed of caustic soda is preferably used. Therefore, it is convenient to use caustic soda for the above neutralization.

However, if the dissolution of phenol is proceeded without a catalyst, the problem of neutralization does not occur. Considering the formation of a salt by neutralization, etc., the phenolization without catalyst is more preferable in this regard. Further, in the phenolation reaction, when a Lewis acid such as boron trifluoride is used as a catalyst, it is used as a catalyst for subsequent resinification, or a catalyst such as hydrochloric acid or trifluoroacetic acid is recovered by distillation or the like. In some cases, neutralization of the catalyst is not necessary.

In preparing the phenolated lignin-containing mixture, the lignin material is used in a ratio of 10 to 150 parts by weight based on 100 parts by weight of the phenol compound. That is, the amount of the lignin material used is 9.1 to 60% by weight based on the total amount of the phenol compound and the lignin material, whereby a lignin-phenol resin composition having practically sufficient adhesion performance can be obtained. . If the amount of lignin material used is less than 10 parts by weight (9.1% by weight) with respect to 100 parts by weight of phenol, there is no point in using lignin material, and if it exceeds 150 parts by weight (60% by weight), To dissolve high concentrations of lignin material, methanol,
A complicated process such as distilling off the solvent after performing solvolysis using a mixed solvent of low boiling point dissolution such as acetone and phenol is required.

In addition, in the preparation of the addition / condensation reaction product of the phenolated lignin-containing mixture and formaldehyde, the amount of formaldehyde used is 30 to 250 parts by weight per 100 parts by weight of the phenol compound, but the amount of the lignin material and the phenol material is used. Is preferably 10 to 100 parts by weight per 100 parts by weight of the total amount of If the amount of formaldehyde used is less than 30 parts by weight per 100 parts by weight of the phenol compound, the curability of the resulting reaction product will be unsatisfactory, and if it exceeds 250 parts by weight, the resulting reaction product The storage stability becomes practically unsatisfactory.

In the preparation of another resin composition of the present invention, 100% of lignin-phenol resin produced by addition / condensation reaction of a phenolated lignin-containing mixture with formaldehyde
Parts by weight and 1 to 50 parts by weight of at least one selected from a resorcinol compound and a resorcinol compound-formaldehyde precondensate. The above two components may be mixed and reacted.

The resorcinol compound used in the present invention is selected from resorcinol, alkyl resorcinol (for example, methyl-, dimethyl-trimethyl-resorcinol and mixtures thereof), meta-cresol, meta-aminophenol, tannin and the like.

The resorcinol compound-formaldehyde precondensate used in the present invention is obtained by converting at least one of the above resorcinol compounds and formaldehyde into a suitable catalyst such as caustic soda, potassium hydroxide, ammonia, calcium hydroxide, and magnesium hydroxide. It can be produced by condensation in the presence of a basic catalyst or an acidic catalyst such as hydrochloric acid, sulfuric acid, formic acid, acetic acid and phenolsulfonic acid. At this time, the molar ratio between the resorcinol compound and formaldehyde is 1: 0.5 to
Preferably it is 1: 1.5. If the amount of formaldehyde is less than 0.5 mol, the curability of the obtained resin composition may be unsatisfactory, and if it is more than 1.5 mol, the storage stability of the obtained initial condensate and the resin composition Can be unsatisfactory.

In the resin composition of the present invention, the addition / condensation product 10 of a phenolated lignin-containing mixture and formaldehyde
0 parts by weight of at least one resorcinol compound component selected from a resorcinol compound and a resorcinol compound-formaldehyde precondensate is added to 1 part by weight.
To 50 parts by weight, preferably 5 to 25 parts by weight.

The resorcinol compound-formaldehyde precondensate used in the present invention has a copolymer component of 10 mol or less, for example, phenol, based on 1 mol of the resorcinol compound.
It may contain cresol and the like.

When the amount of the resorcinol compound and / or resorcinol compound-formaldehyde precondensate is less than 1 part by weight, the desired effect of strengthening resorcinol is unsatisfactory, and when it is more than 50% by weight, it is obtained. The disadvantage is that the effective storage time and the pot life of the composition or the adhesive are reduced, which is economically disadvantageous.

The reaction (or copolymerization reaction) between the resorcinol compound and / or the resorcinol compound-formaldehyde precondensate and the lignin-phenol resin is 100 ° C. or less,
The reaction is preferably carried out at a temperature of from room temperature to 80 ° C., and the time required for the reaction is generally from 1 minute to 20 hours.

In the resin composition of the present invention, by adding a resorcinol compound and / or a resorcinol compound-formaldehyde initial condensate to a lignin material-phenol compound-formaldehyde addition / condensation reaction product, high-speed curability of the resin composition, and Not only can the storage stability be improved, but also the permeability and transferability to the surface to be bonded can be improved, and the occurrence of the dry bonding phenomenon can be prevented.

The resin composition of the present invention is useful as a main component of the adhesive, and when used, further includes a curing agent such as paraformaldehyde formalin or hexamethylenetetramine, if necessary. And a filler and an extender may be further added.

In the composition of the present invention, a resorcinol, paraformaldehyde, and formalin are used in a copolymerization reaction between an addition / condensation reaction product of a phenolated lignin-containing mixture and formaldehyde with a resorcinol compound and / or a resorcinol compound-formaldehyde initial condensate. As the amount of formaldehyde added increases, the curing properties of the resulting resin composition, and the water resistance of the adhesive increases, but the pot life is shortened, and therefore, it is necessary to balance these properties appropriately. is important. If components containing formaldehyde, such as formalin, which can be directly supplied to the reaction system are added after a certain limit or more, or if such components are present in the reaction system in large amounts in advance, The curability of the resin composition of the invention is remarkably enhanced, and the pot life is remarkably reduced. Therefore, the use of hexamethylenetetramine has given good results for the purpose of shortening the curing time but not shortening the pot life. In addition, at the time of lignin-phenol resin preparation, the amount of formaldehyde to be added was set to about 2.5 mol per 1 mol of the phenol compound,
In the case where the chemical species that formaldehyde is not added later, if the resorcinol compound is added in an excess amount of 10% or more based on the weight of the obtained resin composition, the curability decreases with the increase in the added amount. Is generated. This is presumably because the free resorcinol compound exhibited a melting effect due to lack of formaldehyde in the reaction system. Following the post-addition of the resorcinol compound as described above, the reaction mixture is allowed to react at temperatures up to medium temperature, such as by allowing it to stand at room temperature for 1 minute to 20 hours or reacting at 35 ° C. for 30 minutes. The reaction is carried out under appropriate conditions within a range that does not lead to curing of the product, or within a range that does not significantly shorten the usable time of the produced resin composition. That is, the reaction is generally performed at a temperature of 100 ° C. or less, preferably room temperature to 80 ° C., for example, for 1 minute to 20 hours.

In the present invention, as one of the main components of the resin composition, a large amount of a lignin material, which is considerably less expensive than a phenol compound, is used (50 to 60% of the lignin material as compared with a case where only a phenol compound is used). In other words, the phenol compound: lignin material weight ratio is 100:
Even at 100 to 100: 150, the performance of the obtained adhesive is not reduced), and the cost reduction of the obtained resin composition and adhesive can be expected. In this way, it is possible to use a toughening agent which is more expensive than phenol economically because of the lower raw material cost. In the present invention, even when alkylresorcinol is used in the above range, a sufficient effect has been recognized. The price of alkyl resorcinols such as methyl- and dimethyl-resorcinol is four times as high as that of phenol, but is said to be half that of resorcinol.

In order to further improve the performance of the resin composition adhesive of the present invention, various additives can be added before use. For example, adjusting the viscosity of the adhesive, reducing costs,
It is desirable to add a bulking agent or a filler for the purpose of decreasing the thermal swelling rate, decreasing the curing shrinkage rate, suppressing heat generation during curing, and improving the adhesiveness. As bulking agents, wheat flour, barley flour, rice flour, corn flour and other flour, as well as defatted soy flour, blood flour, animal and plant protein powders such as casein powder, and the like are commonly used in phenolic resin adhesives. Agents can be used. Preferable examples of the filler include inorganic ones such as crushed stone, sand, silica, talc, calcium carbonate, clay, sodium carbonate, slaked lime, and the like, and further, reinforcing filler such as mica, asbestos, glass flakes, and the like. In addition to the agents, depending on the purpose, quartz powder, graphite, porcelain powder, alumina, silica gel (especially effective for giving thixotropy properties), aluminum, aluminum oxide, iron, iron oxide, etc.
And metals that contribute to the thermal swelling coefficient, thermal conductivity, and adhesion such as copper, and inorganic materials that provide flame retardancy such as antimony oxide. Also,
Organic fillers include wheat flour, walnut, coconut flour, wood flour, fir powder, fine plastic powder (phenolic resin, urea resin, etc.), glass fiber, rock wool, carbon fiber, etc. A material having a function as a filler for weight reduction can be used.

Furthermore, in order to improve the performance of the adhesive, the pre-oligomer solution state adhesive may be replaced with a conventionally used amino resin such as urea resin and melamine resin, as well as natural and synthetic polymers, oligomers and low molecular weight compounds. Plasticizers and other known additives (such as heat-resistant agents, weather-resistant agents, lubricants, and fibrous reinforcing agents) can be added.

The adhesive of the present invention is usually used by applying it to a surface to be bonded in a solution or paste form. Bonding conditions such as bonding temperature, bonding time and bonding pressure in the bonding operation are as follows:
It can be set according to the conditions used for a conventional water-soluble phenol resin adhesive. In particular, the bonding temperature can be reduced rather than conventional phenolic resin adhesives. That is, bonding temperature: 120 ° C. to 140 ° C., bonding time: 0.5 to 1 (min / mm thickness, plywood), bonding pressure: 7 to 15 kg f / cm ²
Under such bonding conditions, excellent bonding including water resistance can be performed.

The bonding operation using the adhesive of the present invention includes pressing at room temperature,
In addition to hot pressing by hot pressing, high frequency heating,
It can be appropriately carried out by using a heat and pressure method by microwave heating and low voltage heating.

The adhesive of the present invention can be used for wood building materials, ceramic building materials, general woodworking, and a part of the bonding between wood and other materials. In addition, metal materials, plastic materials, inorganic materials, fiber materials, etc. It can be used for bonding various materials including. Further, the composition of the present invention can also be used for applications in which a phenol resin is usually used as a matrix resin for a composite material or a resin for a molding material.

Example 1. 100 parts by weight of thiolignin and 108.7 parts by weight of 8% water-containing phenol were weighed into a stainless steel pressure-resistant reaction tube and heated in a 200 ° C. oil bath for 1 hour to convert thiolignin into phenol without catalyst. To this reaction solution, a 35% aqueous formaldehyde solution was weighed such that the amount of formaldehyde was 2.5 mol per 1 mol of phenol, and added to the above phenolized thiolignin-phenol solution. % Aqueous sodium hydroxide solution was added to adjust the pH of the solution to 9. The reaction mixture was transferred to a 500 ml two-necked flask having a stirrer and a condenser, and reacted at 90 ° C. for 1 hour with stirring to prepare a lignin-phenol resin composition. During the reaction, the pH of the reaction solution was measured about every 20 minutes, and a 40% aqueous sodium hydroxide solution was added so as to maintain the pH at 9.

Five parts of coconut husk powder were added to the lignin-phenol resin composition, and the composition was subjected to the following adhesion test.

Adhesion test As an adhesion specimen, a birch straight grain veneer with a thickness of about 2 mm (11 × 1
1 cm) was applied to one side of the test piece, and the coating amount per one bonded surface was set to 120 g / m ² . At this time, the adhesive coupons were overlapped so that the wood embedding direction was orthogonal so as to form a 3-ply plywood, which was subjected to cold pressing under a pressure of 13 kg f / cm ² for 30 minutes. Heat-pressing of 13 kg f / cm ² was performed. After the adhesive was left in a room overnight, a specimen for a tensile shear test was cut out according to a conventional method. In this way, for each adhesive, four specimens for measuring normal adhesive strength and four specimens for measuring water-resistant adhesive strength were prepared. The measurement of the normal adhesive force was performed using a Shimadzu Autograph DCS-R-500 at a tensile speed of 1.0 mm / min according to a conventional method. The evaluation of the water-resistant adhesive ability was performed by a repeated boiling test (boiled for 4 hours → dried at 60 ° C. for 20 hours → boiled for 4 hours → put in cold water, left for about 15 minutes → measured adhesive strength in a wet state). The adhesion was measured at a tensile speed of 1.0 mm / min in the same manner as above, using Shimadzu Autograph DCS.
-R-500 was used. Table 1 shows the obtained results.

Comparative Example 1. The same operation as in Example 1 was performed. However, the first phenolation reaction was omitted.

The obtained resin composition showed almost satisfactory adhesion in a normal state, but in the boiling repeated test,
All the adhesive parts peeled off.

Example 2 The same operation as in Example 1 was performed. However, thiolignin
100 parts by weight and 108.7 parts by weight of 8% aqueous phenol were transferred to a 500 ml two-necked flask having a cooling tube, 10 parts by weight of 35% hydrochloric acid was added, and the mixture was reacted at 80 ° C. for 1 hour with stirring to obtain a catalyst-free catalyst. Phenolized. Table 2 shows the results of an adhesion test performed using the obtained adhesive comprising the addition / condensation composition.

Examples 3 to 11 and Comparative Example 2 In each of Examples 3 to 8, the amount of alkylresorcinol (100 parts) based on 100 parts of the lignin-phenol resin liquid obtained by the same operation as described in Example 1 was used. Nagoya Yuka Co., Ltd.), and the resulting reaction mixture is heated at 35 ° C. for 30 minutes.
The reaction was carried out with stirring for minutes. After completion of the reaction, the mixture was cooled to room temperature, and paraformaldehyde, hexamethylenetetramine and coconut husk powder were added in the amounts shown in Table 3 and stirred, and the obtained resin adhesive was subjected to the same adhesion experiment as described in Example 1. Provided. Table 4 shows the obtained results.

The required value of the conventional JIS standard for the adhesive strength of a water-soluble phenolic resin (resole resin) adhesive in a tensile shear test is 12.0 kg f / cm ² for normal adhesive strength and 10.0 kg f / cm ² for water resistant adhesive strength. / cm ² . From this point, all of the resin adhesives of the present invention, except for Example 4, have reached the required values of the standard. That is, the above bonding conditions are 120 ° C,
Although such excellent results were obtained in spite of the extremely mild bonding conditions for a phenolic resin adhesive of 6 minutes, it means that the resin composition of the present invention is a urea resin and a melamine resin. This is a water-soluble phenolic resin adhesive that can be bonded under the same conditions as the bonding conditions, and is of great technical and practical significance.

In Comparative Example 2, the same operation as in Example 6 was performed.
However, the lignin material is not phenolized, that is, 20
A phenol solution obtained by mixing and dissolving kraft lignin directly in phenol at 50 ° C. without performing a reaction for 1 hour in an oil bath at 0 ° C. was used. Table 3 shows the types and amounts of the additives. Table 4 shows the results.

In Example 9, the same operation as in Example 3 was performed. However, 10 parts by weight of alkyl resorcinol was mixed with 100 parts by weight of lignin-resole resin solution together with 5 parts by weight of coconut husk powder during the bonding operation without adding alkyl resorcinol and reacting at 35 ° C. for 30 minutes.

 The results are shown in Table 4.

In Example 10, the same operation as in Example 3 was performed. However, 15 parts by weight of tannin was used instead of alkylresorcinol. This tannin was larch tannin. The other conditions were the same as in Example 3. The results are shown in Table 4.

In Example 11, the same operation as in Example was performed. However, 5 parts by weight of resorcinol was used in place of the alkyl resorcinol.

 The results are shown in Table 4.

Example 12 Kraft lignin 100 parts by weight and 8% aqueous phenol 10
Weigh 8.7 parts into a stainless steel pressure-resistant reaction tube, and add 35% hydrochloric acid 10
The mixture was added in parts by weight and phenolized in a 150 ° C. oil bath for 1 hour. Then, a 37% aqueous solution of formaldehyde was weighed so that the formaldehyde content was 2.5 moles per mole of phenol, added to the above kraft lignin / phenol solution, and further added with a 40% aqueous solution of caustic soda to adjust the pH of the solution to 9. It was adjusted. It was transferred to a 500 ml two-necked flask equipped with a stirrer and a condenser tube, and reacted at 90 ° C. for 1 hour with stirring to resinify.

Measure the pH about every 20 minutes during the reaction, and
% Caustic soda aqueous solution was added. After completion of the reaction, a 40% aqueous sodium hydroxide solution was added to the resin solution to adjust the pH to 11.

A phenol / resorcinol resin solution (manufactured by Hosei Oil KK, based on 100 parts by weight of the obtained lignin / phenol resin solution)
RW-203), 50 parts by weight, and 5 parts by weight of flour and 10 parts by weight of coconut shell powder were further added and uniformly mixed to prepare a size liquid.

This glue solution is applied on both sides of a 2.5 m / m thick, 15 × 15 cm single lauan veneer at a rate of 150 g / m ² per adhesive layer.Furthermore, a lauan veneer of the same thickness is applied on both sides, its grained direction superposed so as to be perpendicular to each other, the pressure 10 kg / cm ² 20 under
℃ Temporary clamping. Thereafter, by a hot press maintained at 120 ° C., a pressure of 10 kg / cm ² was applied and the mixture was heated for 3 minutes and 30 seconds.

The bond strength of the 3-ply sample plywood obtained in this way was determined by JA
It was measured by the test method of S special plywood. As a result, the average bond strength of the normal state was 15.6 kg / c ² , the wood breakage rate was 100%, and the bond strength after continuous boiling treatment for 72 hours was 11.1 kg / cm ² , and the wood break rate was 37.
%.

Comparative Example 3. Commercially available phenolic resin adhesive (manufactured by Hosei Oil KK, PF-10
9) Using a glue solution in which 100 parts, 5 parts of flour and 10 parts of coconut husk were mixed, 3 ply Rawan plywood was bonded under the same bonding conditions as described in the examples, and the bonding strength was determined by the JAS special plywood test method. Was measured. As a result, the average bond strength is 7.
Although the weight was 3 kg / cm ² and the wood breaking rate was 0%, the adhesive was peeled off by continuous boiling treatment for 72 hours.

〔The invention's effect〕

The lignin-phenol resin composition and adhesive of the present invention contain a large amount of lignin material as a raw material, and have strong adhesive strength under mild adhesive conditions (temperature and time) similar to ordinary urea resins and melamine resins. Can be expressed.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C09J 161/06 JEQ C09J 161/06 JEQ JES JES (56) References JP-A-51-14994 (JP, A) JP-A-51-92892 (JP, A) JP-A-51-148731 (JP, A) JP-A-63-112678 (JP, A) JP-A-63-112677 (JP, A) JP-A-52-8042 (JP, A) JP-A-52-93444 (JP, A) JP-A-61-64708 (JP, A)

Claims (4)

(57) [Claims] 1. A phenolized lignin-containing mixture obtained by reacting 100 parts by weight of a phenol compound with 10 to 150 parts by weight of a lignin material in the absence of a catalyst or in the presence of an acidic catalyst; A lignin-phenol resin composition comprising an addition / condensation reaction product with part of formaldehyde in the presence of a basic catalyst. 2. An adhesive comprising the lignin-phenol resin composition according to claim 1 as a main component. 3. A phenolized lignin-containing mixture obtained by reacting 100 parts by weight of a phenol compound with 10 to 150 parts by weight of a lignin material in the presence of a catalyst or an acidic catalyst, and 30 to 250 parts by weight of the mixture. Containing 100 parts by weight of an addition / condensation reaction product with formaldehyde in the presence of a basic catalyst, and 1 to 50 parts by weight of at least one selected from a resorcinol compound and a resorcinol compound-formaldehyde precondensate. , Lignin-phenolic resin composition. 4. An adhesive comprising the lignin-phenol resin composition according to claim 3 as a main component.