JP5087232B2 - Resorcin-methyl ethyl ketone-formalin resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resorcin/methyl ethyl ketone/formalin resin that exhibits moderate flowability when converted into an aqueous solution and is reduced in both the content of a resorcin monomer and the content of a resorcin/formalin resin having five or more resorcin nuclei. <P>SOLUTION: The resorcin/methyl ethyl ketone/formalin resin is manufactured by a manufacturing method where a series of processes comprising synthesis of the ketone-modified product by a reaction of resorcin with methyl ethyl ketone and subsequent formalin condensation is carried out in the same reactor, and the gel permeation chromatography analysis of the resorcin/formalin resin gives a peak area corresponding to the resorcin monomer of 3% to 9% and a peak area corresponding to the five or more resorcin nuclei of 30% to 55%, each based on the total peak area. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

The present invention reduces both the resorcin monomer content and the resorcin formalin resin content of resorcin pentanuclear or more by using a resorcin formalin resin subjected to formalin condensation after synthesis of a ketone adduct by reaction of resorcin and methyl ethyl ketone. The present invention relates to a novel resorcin-methylethylketone-formalin resin which has excellent adhesiveness, with less unreacted resorcin being sublimated during use of the agent and deteriorating the working environment.

Conventionally, resorcin formalin resin is used for adhesives, plywood, laminated materials, surface coatings, etc. because of its fast curing speed, and especially has excellent adhesion to rubber and fibers. (See, for example, Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document 4).

When the resorcin formalin resin is used as an adhesive, it is required that the resorcin formalin resin has sufficient fluidity and that it is uniformly dissolved when the solvent coexists. When paying attention to fluidity, it is empirically known that sufficient fluidity can be obtained by reducing the composition ratio of the resorcin pentanuclear or higher from the components of the polycondensate. When the resorcin pentanuclear or higher, the ratio of the three-dimensional structure suddenly increases, and it is considered that fluidity is lost. Although it is conceivable to dilute with an organic solvent in order to impart fluidity, the use of an organic solvent is not preferred because it has the possibility of deteriorating the working environment and reducing the adhesive strength. There is a method in which an adhesive is dispersed in water with an anionic surfactant without using an organic solvent (see, for example, Patent Document 5), but there remains anxiety in terms of long-term stability of the aqueous dispersion.
There is a report that a resin is produced by a two-step reaction for the purpose of suppressing the unreacted formaldehyde content in the resin (see, for example, Patent Document 6). This is a patent for a method for producing an aldehyde resin that will be used as an adhesive for water-repellent paper products such as cardboard. The formaldehyde content in the product is 0.1%. However, this aldehyde resin is not an application of resorcin formalin resin.

Japanese Patent Publication No. 48-12185 JP-A-4-148920 JP-A-6-100850 JP 2000-178849 A JP-A-57-167342 EP0498301A2 publication

As described above, it is known that a sufficient fluidity can be obtained when the solvent is water by reducing the component ratio of the resorcin 5 nucleus or more from the components of the polycondensate. When the reaction conditions are set gently so as to reduce the composition ratio above the nucleus, the product molecular weight distribution simply shifts to the low molecular weight side, and usually the unreacted resorcin concentration increases. . When the resorcin concentration is high, resorcin is sublimated when the adhesive is used, so that the working environment may be deteriorated and the adhesive force may be lowered. When 0.6 mol of formaldehyde is reacted with 1 mol of resorcin, about 33 wt% of unreacted resorcin is contained after the reaction is completed, and about 20 wt.% When 0.8 mol of formaldehyde is reacted. % Unreacted resorcin, the amount of unreacted resorcin should be limited to 15% by weight. In order to reduce the unreacted resorcin content, resorcin was reduced at a reduced pressure of 0.05 mmHg and 130 ° C. It has been reported that sublimation has been removed (see, for example, Patent Document 7). Moreover, it has been reported that the content of unreacted resorcin is reduced to 5.5% by using a continuous extractor with methyl isobutyl ketone as a solvent and water as an extractant (see, for example, Patent Document 8). However, these methods are industrially disadvantageous, such as requiring vacuum distillation after completion of the reaction or requiring a long operation using a continuous extractor.

Conversely, if the reaction conditions are made violent in order to reduce the concentration of unreacted resorcin, a large amount of resorcin polynuclear body having 5 or more nuclei is generated, which is not preferable. Here, since the reaction is carried out in an aqueous system, a method of adding a high-concentration salt after the completion of the reaction to lower the solubility of the high molecular weight component and removing it after precipitation can be considered. However, this method is disadvantageous because it requires the addition of a salting-out step, and there are concerns about the decrease in adhesive strength due to the inorganic salt remaining in the resorcin formalin resin and the corrosion of the adherend due to the inorganic salt. It has not been. There has been disclosed a device that does not add this salting-out step and does not increase the composition ratio of seven or more nuclei even in a one-stage reaction (see, for example, Patent Document 9). In order to reduce the solubility of the resorcinol multinuclear body, a large amount of salt coexists in the reaction system. However, in this method, the resorcinol multinuclear body precipitated from the aqueous phase becomes gummy, so even resorcinol is a gum. As a result, the reaction time is lowered and the reaction time is prolonged. In industrial production, the production of a gum-like substance in a long-time reaction is difficult to employ because it causes stirring stoppage, clogging of the liquid feeding system, and the like.

Japanese Patent Publication No.54-932 Japanese Patent Publication No.49-14550 JP 2003-277308 A

The present invention is a resin produced by a production method in which all steps are carried out in the same reaction vessel, has an appropriate fluidity when made into an aqueous solution, and contains a resorcin monomer content without an extraction step. And a resorcin-methylethylketone-formalin resin containing a reacted methyl ethyl ketone in the resin in which both the content of a resorcin formalin resin having a ketone modified with a resorcin 5 nucleus or more and a resorcin formalin resin having a resorcin 5 nucleus or more are reduced. It is an object.

In the present invention, 100 parts by weight of resorcin (A), 2 to 50 parts by weight of methyl ethyl ketone (B), 0.01 to 2 parts by weight of an organic or inorganic acid (C) as a catalyst, or 1 to 40 parts by weight of water are mixed. 1 part to 25% of the resorcin (A) charged to make resorcin-methylethylketone reaction product (f), and then 1 to 40% formalin. (D) is added to and reacted with resorcin (A) in a formaldehyde / resorcin = 0.3 to 0.8 mol ratio, and after cooling, 1 to 30% aqueous ammonia (E) is added with an organic acid or an inorganic acid ( It is obtained by gel permeation chromatography analysis of the resin (F), which is a resin (F) obtained without adding a liquid-liquid partitioning step, by adding 1.0 to 2.0 times the mole of C). The peak area corresponding to the resorcin monomer is 3 to 9% with respect to the entire peak area, the peak area corresponding to the resorcin 5 nucleus or more is 30 to 55%, and methyl ethyl ketone is incorporated into the molecule. and the components contained 1-25 wt% in the solid content of the resin (F), finally the solid concentration of the resin (F) is 35 to 60 wt%, viscosity of 50~10, 000mPa · s / Resorcin-methyl ethyl ketone-formalin resin characterized by being at 24 ° C.

In the present invention, a methanol distillation step is further added to the resin (F) obtained by adding 1 to 30% ammonia water (E) to remove residual methanol in the resin (F). it can.

The resorcin-methyl ethyl ketone-formalin resin of the present invention contains 1 to 25% by weight of reacted methyl ethyl ketone in the solid content of the resin (F). The methyl ethyl ketone content can be adjusted by the ratio of resorcin (A) to methyl ethyl ketone (B) during the reaction. In addition, the amount of resorcin-methyl ethyl ketone reaction product (f) obtained by the reaction of resorcin (A), methyl ethyl ketone (B), organic acid or inorganic acid (C) as a catalyst is measured at an intermediate stage. The resorcin-methyl ethyl ketone reaction product (f) can be analyzed in an intermediate stage and the ratio of unreacted resorcin to resorcin-methyl ethyl ketone reaction product (f) can be readjusted according to the results. it can.

The resorcin-methyl ethyl ketone-formalin resin of the present invention is characterized by being produced by a two-stage reaction by a reaction between resorcin and methyl ethyl ketone and a condensation reaction with formaldehyde. In the reaction of methyl ethyl ketone, the increase in molecular weight is 72 of the molecular weight of methyl ethyl ketone, or 54 with a dehydration reaction. On the other hand, in the condensation reaction between resorcin and formaldehyde, the molecular weight of the product usually increases by 122. For this reason, the reaction design for keeping the molecular weight of the product within an appropriate range has an advantage that the methyl ethyl ketone reaction is easier. Resorcin-methyl ethyl ketone-formalin resin is considered to be improved in adhesion performance by containing methyl ethyl ketone in the resin.

  Among the resorcin-methylethylketone-formalin resin finally obtained, the molecular weight MW of the component in which methylethylketone is incorporated in the molecule is MW = 110 × k + 72 × l + 30 × m-18 × n (k, l, m, n represents an integer). Here, 110 is the molecular weight of resorcin, 72 is the molecular weight of methyl ethyl ketone, 30 is the molecular weight of formaldehyde, and 18 is the molecular weight of water. The relationship between these numerical values is k + l + m≈n + α, 2 ≦ k, 1 ≦ l, 0 ≦ m, and α = 1 or 2. The component in which this methyl ethyl ketone is incorporated into the molecule is obtained by liquid chromatography analysis as a peak having a longer retention time than the pentanuclear component that does not contain methyl ethyl ketone in the molecule. Can be grasped. In the present invention, the resorcin n-nucleus means both the n-nucleus of the resorcin formalin resin itself and the ketone-modified resorcin formalin resin having a molecular weight slightly higher than that of the resorcin formalin resin itself due to ketone modification. ing. In addition, the molecular weight of each n nucleus is determined based on the peak of the gel permeation chromatograph of the resorcin formalin resin itself.

In the first-stage ketone addition reaction and the second-stage condensation reaction, the reaction is controlled so that the number of components of five or more nuclei does not increase, so the final reaction product is a mixture with water. Despite being present, it has an appropriate fluidity when used in an adhesive. It is also advantageous that all the steps up to the final product are a production method performed in the same reaction vessel.

Examples of the organic acid or inorganic acid (C) used as a catalyst in the production process of resorcin-methyl ethyl ketone-formalin resin include hydrochloric acid, sulfuric acid, phosphoric acid, benzenesulfonic acid, toluenesulfonic acid and the like. Preference is given to p-toluenesulfonic acid and hydrochloric acid.

The resorcin-methylethylketone-formalin resin of the present invention can be carried out in the same reaction vessel without any extraction process, and the content of resorcin monomer and the content of ketone-modified resorcin formalin resin of resorcin pentanuclear or higher Both are reduced, and the molecular weight is within the proper range, so that it has moderate fluidity when made into an aqueous solution, and unreacted resorcin sublimates when using an adhesive, which may deteriorate the working environment. Less, it has excellent adhesion by containing reacted methyl ethyl ketone in the resin.

  As the reaction tank used for the production, an acid catalyst reaction is performed, so that an ordinary apparatus can be used as long as it is acid-resistant.

  The formaldehyde concentration in formalin (D) used for production is 1 to 40%, preferably 30 to 40%. Further, the amount of formalin used is such that the number of moles of formaldehyde in formalin is formaldehyde / resorcin = 0.3 to 0.8 mol ratio, preferably formaldehyde / resorcin = 0.5 to 0.8 mol ratio with respect to resorcin (A). The amount is such that

  When mixing resorcin (A), methyl ethyl ketone (B), catalyst organic acid or inorganic acid (C), water under stirring, resorcin (A), catalyst organic acid or inorganic acid (C), water Can be mixed and methyl ethyl ketone (B) can be added dropwise little by little. The dropping time of formalin (D) is 1 to 300 minutes, preferably 20 to 120 minutes, and more preferably 60 to 120 minutes.

  Hereinafter, the present invention will be described in detail with reference to examples.

After putting 50 g of water and 500.0 g of resorcin into a 2 liter glass Kolben and dissolving at 70 to 75 ° C., 2.0 g of paratoluenesulfonic acid was put into the reaction vessel. While maintaining this temperature, 80 g of methyl ethyl ketone was added and stirred and mixed, and then the temperature was raised to 80 to 85 ° C. and reacted at this temperature for 4 hours to obtain a resorcin-methyl ethyl ketone reaction product. After completion, while cooling and maintaining the liquid temperature at 50 to 55 ° C., 221.1 g of 37% formaldehyde (formaldehyde / resorcin = 0.60 mol ratio) was added dropwise over 240 minutes, and the mixture was further stirred for 60 minutes after completion of the addition. The reaction was allowed to proceed. After cooling the temperature of the reaction system to room temperature, 25% aqueous ammonia was added until pH 8-9. Next, water was added to adjust the solid content to 50% by weight to obtain 1226 g of a ketone-modified resorcin resin having a reduced resorcin formalin resin content of resorcin and resorcin pentanuclear (resorcin content is 8.5%, solids) Min 613g).

The obtained ketone-modified resorcin formalin resin was dissolved in tetrahydrofuran and subjected to gel permeation chromatography analysis, and the distribution of unreacted resorcin to resorcin pentanuclear or higher was measured. The obtained chromatogram is shown in FIG. The peak area ratio of the obtained chromatogram was as follows.
Resorcinol: 8.5%
Resorcin dinuclear ... 17.5%
Resorcin trinuclear body ... 11.3%
Resorcin tetranuclear ... 12.7%
More than resorcin 5 nucleus ... 50.0%

The gel permeation chromatography analysis conditions employed are shown below.
Measurement model: Tosoh HLC-8020
Column: manufactured by Tosoh (G-2500) + (G-2500) + (G-4000)
Column temperature: 40 ° C
Solvent: Tetrahydrofuran Flow rate: 1 ml / min

  The obtained resorcin-methyl ethyl ketone-formalin resin was subjected to liquid chromatography analysis. The obtained results are shown in FIG. In the case of a ketone-modified resorcin formalin resin, a new peak (methyl ethyl ketone adduct) appears after 30 minutes by reacting with methyl ethyl ketone, and these components may newly improve the adhesion performance and the like. is there.

The adopted liquid chromatography analysis conditions are shown below.
Measurement model: Shimadzu HPLC LC-10A
Column: Inertsil ODS-3
Column temperature: 40 ° C
Detector: UV (283 nm)
Solvent: methanol / water = 30/70 → 90/10 (80 minutes)
Flow rate: 1.0 ml / min

After putting 50 g of water and 500.0 g of resorcin into a 2 liter glass Kolben and dissolving at 70 to 75 ° C., 2.0 g of paratoluenesulfonic acid was put into the reaction vessel. While maintaining this temperature, 40 g of methyl ethyl ketone was added dropwise over 4 hours, and after completion of the addition, a resorcin-methyl ethyl ketone reaction product was stirred for an additional 4 hours to proceed the reaction. After completion of the reaction, while cooling and maintaining the liquid temperature at 50 to 55 ° C., 379.6 g of 37% formaldehyde (formaldehyde / resorcin = 0.65 mol ratio) was added dropwise over 240 minutes, and the mixture was further stirred for 60 minutes after completion of the addition. The reaction proceeded. After cooling the temperature of the reaction system to room temperature, 25% aqueous ammonia was added until pH 8-9. Next, water was added to adjust the solid content to 50% by weight to obtain 1152 g of resorcin-methylethylketone-formalin resin having a reduced resorcin-formal resin content of resorcin and resorcin pentanuclear (resorcin content is 8.6%). 576 g solids).

In the same manner as in Example 1, the obtained resorcin-methyl ethyl ketone-formalin resin was dissolved in tetrahydrofuran and subjected to gel permeation chromatography analysis, and the distribution of unreacted resorcin to resorcin pentanuclear or higher was measured. The peak area ratio of the obtained chromatogram was as follows.
Resorcinol 8.6%
Resorcin dinuclear body 16.7%
Resorcin trinuclear ... 10.7%
Resorcin tetranuclear ... 12.0%
More than resorcin 5 nucleus ... 52.0%

When a resorcin-methyl ethyl ketone reaction product was obtained, a very small amount was collected and subjected to gel permeation chromatography analysis in the same manner as in Example 1. The obtained chromatogram is shown in FIG. It can be seen that about 20% of the raw material resorcin is changed to a resorcin-methyl ethyl ketone reaction product.

After putting 50 g of water and 500.0 g of resorcin into a 2 liter glass Kolben and dissolving at 70 to 75 ° C., 2.0 g of paratoluenesulfonic acid was put into the reaction vessel. While maintaining this temperature, 160 g of methyl ethyl ketone was added and stirred and mixed, and then the temperature was raised to 80 to 85 ° C. and reacted at this temperature for 8 hours to obtain a resorcin-methyl ethyl ketone reaction product. After completion of the reaction, 184.3 g of 37% formaldehyde (formaldehyde / resorcin = 0.50 mol ratio) was added dropwise over 240 minutes while cooling and maintaining the liquid temperature at 50 to 55 ° C., followed by stirring for 60 minutes after completion of the addition. The reaction proceeded. After cooling the temperature of the reaction system to room temperature, 25% aqueous ammonia was added until pH 7 and methanol was distilled off. And after cooling to room temperature, 25% ammonia water was added until it became pH 8-9. Then, 1374 g of resorcin-methylethylketone-formalin resin having a reduced resorcin-formalin resin content of resorcin and resorcin pentanuclear was obtained by adding water to adjust the solid content to 50% by weight (resorcin content was 8.3%). , 687 g solids).

In the same manner as in Example 1, the obtained resorcin-methyl ethyl ketone-formalin resin was dissolved in tetrahydrofuran and subjected to gel permeation chromatography analysis, and the distribution of unreacted resorcin to resorcin pentanuclear or higher was measured. The peak area ratio of the obtained chromatogram was as follows.
Resorcinol: 8.3%
Resorcin dinuclear ... 18.8%
Resorcin trinuclear body ... 12.4%
Resorcin tetranuclear ... 14.2%
More than resorcin 5 nuclei ... 46.3%

[Comparative Example 1]
After putting 50 g of water and 500.0 g of resorcin into a 2 liter glass Kolben and dissolving at 70 to 75 ° C., 2.0 g of paratoluenesulfonic acid was put into the reaction vessel. While maintaining the temperature by lowering the reaction system to 50 to 55 ° C., 221.1 g of 37% formaldehyde (formaldehyde / resorcin = 0.60 mol ratio) was added dropwise over 240 minutes, and after completion of the addition, stirring was continued for another 60 minutes. Made progress. After cooling the temperature of the reaction system to room temperature, 25% aqueous ammonia was added until pH 8-9. Next, water was added to adjust the solid content to 50% by weight to obtain 1065 g of resorcin formalin resin (resorcin content 15.3%, solid content 533 g).

The obtained resorcin formalin resin was dissolved in tetrahydrofuran and subjected to gel permeation chromatography analysis to measure the distribution of unreacted resorcin to resorcin pentanuclear or higher. The analysis conditions were the same as in Example 1, and the obtained chromatogram is shown in FIG. The peak area ratio of the obtained chromatogram was as follows. Further, liquid chromatography analysis was performed under the same conditions as in Example 1. The obtained results are shown in FIG.
It can be seen that no clear peak exists after 30 minutes as compared with FIG.
Resorcinol ... 15.3%
Resorcin dinuclear body ... 18.3%
Resorcin trinuclear body ... 15.0%
Resorcin tetranuclear ... 12.0%
More than resorcin 5 nuclei ... 39.4%

LC / MS analysis was performed on the resorcin-methyl ethyl ketone-formalin resin obtained in Example 1 and the resorcin-formalin resin obtained in Comparative Example 1. The resulting chromatograms from the UV detector are shown in FIG. 6 and FIG. It was possible to confirm from resorcin formalin resin 2 nuclei to 7 nuclei. In FIG. 6, there are many peaks with a longer retention time than in the 7-core resorcin formalin resin, whereas in FIG. 7, it is recognized that they do not exist. The peak having a retention time of 25 minutes in FIG. 6 was confirmed to have a molecular weight of 328. This product with a molecular weight of 328 corresponds to that of k = 2, m = 0, n = 2 in the molecular weight calculation formula, and it is proved that MW = 110 × 2 + 72 × 2 + 0−18 × 2 = 328.

The LC / MS analysis conditions are as follows.
[LC conditions]
Measurement model:
Column: Inertsil ODS-3 2.1 x 250 mm
Column temperature: 40 ° C
Detector: UV (283 nm)
Solvent: methanol / 10 mM NH 4 OAc = 50/50 → 100 (60 minutes)
Flow rate: 0.2ml / min
Injection volume: 2.0 μl
Sample concentration: about 1000ppm
[MS conditions]
Measurement model: Waters 2695 Alliance / Quattro micro
API
Detector: ESI (-)
Cone voltage: 30 eV
MS: 100-1000 m / z
SCAN: 0.5sec
Injection volume: 2 μl

The resorcin-methylethylketone-formalin resin of the present invention can make the resorcin content 8% level without an extraction step, has an appropriate fluidity when made into an aqueous solution, and has a resorcin monomer content. And the resorcin-methylethylketone-formalin resin above the resorcin 5 nucleus and the resorcin formalin resin above the resorcin 5 nucleus are reduced, so that the unreacted resorcin sublimates when using the adhesive and the working environment is deteriorated. Since it has an excellent adhesive force, it is advantageous in terms of cost, and is useful as an adhesive for tires and an adhesive for rubber hoses.

1 is a gel permeation chromatograph of resorcin-methyl ethyl ketone-formalin resin obtained in Example 1. FIG. 1 is a liquid chromatograph of resorcin-methyl ethyl ketone-formalin resin obtained in Example 1. FIG. 3 is a gel permeation chromatograph of the resorcin-methyl ethyl ketone reaction product obtained in Example 2. FIG. 2 is a gel permeation chromatograph of the resin obtained in Comparative Example 1. FIG. 3 is a liquid chromatograph of the resin obtained in Comparative Example 1. FIG. 4 is a liquid chromatograph diagram in LC / MS analysis of resorcin-methyl ethyl ketone-formalin resin obtained in Example 2. FIG. 3 is a liquid chromatograph diagram in LC / MS analysis of the resin obtained in Comparative Example 1. FIG.

Claims (6)

100 parts by weight of resorcin (A), 2 to 50 parts by weight of methyl ethyl ketone (B), 0.01 to 2 parts by weight of organic acid or inorganic acid (C) of the catalyst, or 1 to 40 parts by weight of water are further mixed. The reaction mixture is heated to a boiling point or lower, and 1 to 25% of the charged resorcin (A) is converted to a resorcin-methyl ethyl ketone reaction product (f), and then 1 to 40% formalin (D) , Resorcin (A) is added to formaldehyde / resorcin = 0.3-0.8 mol ratio and reacted, and after cooling, 1-30% aqueous ammonia (E) is added to organic acid or inorganic acid (C) 1.0 to 2.0 times the molar amount of the resin, the resin (F) obtained without the liquid-liquid partitioning step, the entire peak obtained by gel permeation chromatography analysis of the resin (F). The peak area corresponding to the resorcin monomer is 3 to 9%, the peak area corresponding to the resorcin pentanuclear is 30 to 55%, and methyl ethyl ketone is incorporated into the molecule. the containing 1-25% by weight of the solid content of the resin (F), finally the solid concentration of the resin (F) is the 35 to 60% by weight, a viscosity of 50~10, 000mPa · s / 24 ℃ Resorcin-methyl ethyl ketone-formalin resin characterized by the above-mentioned. A methanol distillation step is added to the resin (F) obtained by adding 1.0 to 2.0 times mol of the above-described 1 to 30% aqueous ammonia (E) with respect to the organic acid or inorganic acid (C). The resorcin-methyl ethyl ketone-formalin resin according to claim 1. The resorcin-methyl ethyl ketone-formalin resin according to claim 1, wherein the organic acid or inorganic acid (C) is paratoluenesulfonic acid. The number of moles of formaldehyde in the above-mentioned formalin (D) is a ratio of formaldehyde / resorcin = 0.5 to 0.8 mol with respect to the number of moles of resorcin (A). 3. Resorcin-methyl ethyl ketone-formalin resin according to any one of the items. When mixing resorcin (A), methyl ethyl ketone (B), catalyst organic acid or inorganic acid (C), and water, resorcin (A), catalyst organic acid or inorganic acid (C), and water are mixed in advance. ; then, methyl ethyl ketone (B) characterized by mixing beat droplets claims 1 to 4 resorcinol according to any one of Items - methylethylketone - formalin resin. The molecular weight of the component in which methyl ethyl ketone is incorporated in the molecule is MW = 110 × k + 72 × l + 30 × m−18 × n (k, l, m, n represent integers, k + 1 + m≈n + α, and k ≧ 2 And l ≧ 1, m ≧ 0, and α = 1 or 2.) The resorcin-methyl ethyl ketone-formalin resin according to any one of claims 1 to 5.

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