JP4885104B2 - Method for producing ketone-modified resorcin formalin resin - Google Patents

Description

The present invention relates to a method for producing a resorcin formalin resin in which the resorcin formalin resin content and the resorcin formalin resin content of resorcin pentanuclear or more are reduced by adjusting the molecular weight of the resorcin formalin resin.

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

  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. If the reaction conditions are set so as to reduce the composition ratio above the nucleus, the molecular weight distribution of the product is simply shifted to the low molecular weight side. Normally, unreacted resorcin (resorcin mononuclear) The concentration becomes high. 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 when 0.8 mol of formaldehyde is reacted, about 20 wt% In order to reduce the unreacted resorcin content, sublimate resorcin at a reduced pressure of 0.05 mmHg and 130 ° C. to reduce the unreacted resorcin content. It has been reported that it has been removed (see, for example, Patent Document 6). 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 7). 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 8). 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 resorcin, resorcin 2 nuclei As a result, even the body and resorcin trinuclear body are incorporated into the gum-like substance, resulting in a decrease in the reaction rate and a longer reaction time. 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 production method in which a series of steps including one-step reaction and liquid-liquid distribution are performed in the same reactor, and does not contain an inorganic salt and has an appropriate fluidity when made into an aqueous solution. An object of the present invention is to provide a production method capable of producing a ketone-modified resorcin formalin resin in which both the resorcin monomer content and the resorcin formalin resin content of resorcin pentanuclear or higher are reduced.

  Resorcin formalin resin is water-soluble and soluble in some organic solvents, and its ability to dissolve is not biased to either water or organic solvents. It is difficult to connect to. However, the present inventors have studied the reaction between resorcin and formalin from various angles. As a result, by adopting a liquid-liquid heterogeneous reaction using a specific organic solvent, the resorcin monomer content and resorcin pentanuclear are obtained. It has been found that both the resorcin formalin resin content of the body and above can be simultaneously reduced, and the present invention has been completed.

［式中、Ｒ_１、Ｒ_２は同一でも異なっていてもよく、メチル基、エチル基、ｎ−プロピル
基、２−プロピル基、ｎ−ブチル基、セカンダリーブチル基、イソブチル基またはターシ
ャリーブチル基を表す。］ That is, in the present invention, 20 to 150 parts by weight of resorcin (A) is added to 100 parts by weight of water and 20 to 80 parts by weight of inorganic salt (B) is added to 100 parts by weight of water in an aqueous solvent. The organic solvent (C) represented by the following general formula [1], in which the resorcin formalin resin is dissolved and the solubility parameter is 7.5 to 11.0, is 10 to 200 weights per 100 weight parts of resorcin (A). Partly added, stirred at a liquid temperature below the boiling point of the organic solvent (C) to form a two-phase system in which no solid content remains, a catalytic amount of an organic acid or an inorganic acid (D) is added, and the reaction system is changed to 0- While maintaining at 60 ° C., 1-40% formalin (E) with respect to resorcinol (A) as a formaldehyde / resorcinol = 0.3-0.8 mol ratio is added dropwise with stirring. The organic solvent (C) represented by [1] A reaction solvent to form a liquid-liquid heterogeneous, and is used for modification of the resorcinol-formalin resin, a method for producing a ketone-modified resorcinol-formalin resin. The inorganic salt (B) includes one or more cations selected from alkali metals and alkaline earth metals, sulfate ions, nitrate ions, chlorine ions, bromine ions, iodine ions, or thiocyanic acid. It is a salt composed of one or more anions selected from ions and dissolved in 20 to 80 parts by weight with respect to 100 parts by weight of water.

[Wherein R ₁ and R ₂ may be the same or different, and are methyl group, ethyl group, n-propyl group, 2-propyl group, n-butyl group, secondary butyl group, isobutyl group or tertiary butyl group. Represents. ]

20 to 150 parts by weight of resorcin (A) is added to 100 parts by weight of water in an aqueous solvent, 20 to 80 parts by weight of inorganic salt (B) is added to 100 parts by weight of water, and the resorcin formalin resin is dissolved. and, an organic solvent (C) represented by the solubility parameter 7.5 to 11.0 der Ru one general formula [1], 10 to 200 parts by weight was added with respect to resorcinol (a) 100 parts by weight of an organic Stir at a liquid temperature not higher than the boiling point of the solvent (C) to form a two-phase system in which solid content does not remain, add a catalytic amount of organic acid or inorganic acid (D), and maintain the reaction system at 0 to 60 ° C. While, 1 to 40% formalin (E) was added dropwise over 1 to 300 minutes with stirring at a ratio of formaldehyde / resorcin = 0.3 to 0.8 mol with respect to resorcin (A). Stir for 10 to 60 minutes to promote liquid-liquid heterogeneous reaction The reaction system is kept at the reaction temperature and allowed to stand to separate into two layers, the aqueous layer is removed, and the organic solvent (C) is added to the reaction product layer, which is an organic solvent layer. Equivalent to 5 times the amount and diluted, add half the amount of water of this organic solvent, stir the reaction system while maintaining the temperature below the boiling point, let stand and separate into two layers and water According to the production method in which a series of steps including a one-step reaction and liquid-liquid distribution are performed in the same reactor, which is characterized by removing the layer, the gel permeation of the resorcin formalin resin does not contain an inorganic salt. The peak area corresponding to the resorcin monomer is 3% to 9%, and the peak area corresponding to the resorcin pentanuclear is 30% to 55% with respect to the total peak area obtained by the analysis by the chromatography chromatography. A certain ketone-modified resorcin formalin tree It is obtained.

In the present invention, 1-40% formalin (E) is added in a formaldehyde / resorcin = 0.3-0.8 mol ratio with respect to resorcin (A) over 20 minutes to 300 minutes with stirring. There is also a method of adding by dropping intermittently. The dropping time of formalin (E) may be 20 to 120 minutes.

In the present invention, 1 to 10 times the amount of water per weight of the reaction product is added to the organic solvent solution of the ketone-modified resorcin formalin resin, and the organic solvent (C) represented by the general formula [1] is added. After removal by distillation, a ketone-modified resorcin formalin aqueous solution having moderate fluidity with a reaction product concentration of 30 to 80% can be finally obtained .

Further, in the present invention, the organic solvent (C) represented by the general formula [1] with respect to the organic solvent solution of resorcin formalin resin after the second standing and separation into two layers and removing the aqueous layer was diluted by adding the reaction product per weight 2-10 times, by azeotropic temperature of water and an organic solvent distillation carried dehydrated, then be removed by filtration solids was cooled to room temperature I can . To the organic solvent solution obtained here, 1 to 10 times the amount of water per weight of the reaction product is added, and the organic solvent (C) represented by the general formula [1] is removed by distillation to be finally obtained. In addition, a ketone-modified resorcin formalin resin aqueous solution having an appropriate fluidity with a reaction product concentration of 30 to 80% can also be obtained.

  The ketone-modified resorcin formalin resin of the present invention is characterized by adopting a liquid-liquid heterogeneous reaction in its production method, and the advantages obtained by employing the liquid-liquid heterogeneous reaction are as follows. (1) Since the reaction is faster in the aqueous phase and the resorcin abundance ratio depends on the aqueous phase, the amount of unreacted resorcin can be reduced. (2) As the reaction proceeds, the solubility of the resorcinol polynuclear body (especially the four-nuclear body having a three-dimensional structure or more) in the aqueous phase suddenly decreases and shifts to the organic phase. Therefore, the production of resorcin polynuclear body having 5 or more nuclei is suppressed. (3) Since the reaction proceeds in both the aqueous phase and the organic phase, the reaction time can be shortened. (4) The reaction is completed in a one-step reaction between resorcin and formalin, and a process for removing the resorcin polynuclear body after the reaction is not required. (5) For the above reasons, the production amount of both unreacted resorcin and resorcin polynuclear body can be reduced, the reaction time can be shortened, and furthermore, the reaction can be completed in one step, which is costly. Very advantageous.

In addition, the peak area corresponding to the resorcin monomer is 3% to 9% of the total peak area obtained by gel permeation chromatography analysis of the ketone-modified resorcin formalin resin, and corresponds to resorcin pentanuclear or more. A ketone-modified resorcin formalin resin having a peak area of 30% to 55% can be obtained.

  The solubility parameters that define the physical properties of the organic solvent (C) used in the production of the ketone-modified resorcin formalin resin are specifically described in “Solubility Parameters For Film Forms” (Official Digest, October, 1955). Among organic solvents (C), an organic solvent having a solubility parameter of 7.5 to 11.0, preferably 9.0 to 11.0, dissolves resorcin polynuclear bodies, and forms water and a liquid-liquid heterogeneous system. As it is used in the present invention. An organic solvent having a solubility parameter of less than 7.5 has a low solubility of the resorcin polynuclear substance, so that the resorcin multinuclear substance is precipitated as a solid and cannot be used in the production method of the present invention. Moreover, since the organic solvent exceeding 11.0 mixes well with water, it becomes difficult to perform the liquid-liquid heterogeneous reaction which is one of the characteristics of this manufacturing method.

  The organic solvent (C) is an organic solvent that dissolves 1 g or more of the ketone-modified resorcin formalin resin per 100 g of the organic solvent. Moreover, you may use as a 1 type, or 2 or more types of mixture selected from these organic solvents (C).

Specific examples of the organic solvent (C) represented by the general formula [1] include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Among them, methyl ethyl ketone in which R ₁ is a methyl group and R ₂ is an ethyl group is preferable. In the present invention, the organic solvent (C) represented by the general formula [1] is used as a reaction solvent that forms a liquid-liquid heterogeneous system with water, but a part thereof contributes to the modification of the resorcin formalin resin. Yes. This means that the solid weight of the resin obtained through the entire manufacturing process is larger than the theoretical resin solid weight calculated from the amount of resorcin (A) and formalin (E) charged. I understand. Ke ton modified resorcinol-formalin resin, by which is ketone-modified, is considered an improvement is made in the adhesive performance and the like. Ke ton modified resorcinol-formalin resin, a series of steps, but is characterized in that it is manufactured by the manufacturing method carried out in the same reactor, one stage also further ketones denaturing step comprising the reaction and liquid-liquid distribution in one step It is not necessary to provide a new ketone modification step.

  Examples of the inorganic salt (B) used in the production process of the ketone-modified resorcin formalin resin include one or more cations selected from alkali metals and alkaline earth metals, sulfate ions, nitrate ions, Examples thereof include salts composed of one or more anions selected from chlorine ions, bromine ions, iodine ions, and thiocyanate ions. Preference is given to calcium chloride.

  The inorganic salt (B) described above can be used alone or in admixture of two or more. These inorganic salts are used in an amount of 20 to 80 parts by weight, preferably 30 to 50 parts by weight per 100 parts by weight of water. In any case, these inorganic salts are used within the range of solubility in water.

  Examples of the organic acid or inorganic acid (D) used as a catalyst in the production process of the ketone-modified resorcin formalin resin include hydrochloric acid, sulfuric acid, phosphoric acid, benzenesulfonic acid, toluenesulfonic acid and the like. A preferred acid is hydrochloric acid.

To the organic solvent solution of the ketone-modified resorcin formalin resin after completely removing the inorganic salt, 1 to 10 times by weight of water is added to the resorcin formalin resin and distilled to remove the organic solvent, finally the reaction product concentration 30% to 80%, step preferably to obtain a resorcinol-formalin resin aqueous solution having a reaction product concentration 40% to 60% of appropriate fluidity is liable to sol Shin formalin resin is used in the next step It is a form. Moreover, although 1-10 times amount of water is added by weight with respect to resorcin formalin resin, it is the amount of water sufficient to finally make the residual amount of organic solvent 1% or less by azeotropic distillation. It means, and it is safe to deviate from 1 to 10 times the amount. In the next step, the following method described in Japanese Patent Publication No. 48-12185 is adopted. The adhesive stock solution is preferably diluted with water before treating the fiber material or film. This is because when an appropriate amount of a basic substance is added to the dilution water, the adhesive is easily dissolved.

The ketone-modified resorcin formalin resin obtained by the present invention does not contain an inorganic salt, and both the resorcin monomer content and the resorcin formalin resin content of resorcin pentanuclear or more are reduced. Therefore, the unreacted resorcin is not sublimated when the adhesive is used, and the working environment is not deteriorated. In addition, since a series of processes including one-step reaction, liquid-liquid distribution, and ketone modification is performed in the same reactor, it is advantageous in terms of cost.

  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. As reaction temperature, it is desirable that it is below the boiling point of the organic solvent to be used. Further, since it is necessary to dissolve the salt in water at a high concentration, it is necessary to make the temperature somewhat higher than room temperature in order to ensure solubility. The reaction temperature is 0 to 60 ° C., preferably 30 to 50 ° C.

  The organic solvent used in the production can be recovered by distillation after being distilled again after being separated by distillation. The salt used in the present invention can be recovered after separation and reused.

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

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

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.
[Example 1]

  266 g of water, 171 g of calcium chloride, and 73.8 g of resorcin were placed in a 1 liter glass Kolben, dissolved at 50 ° C., and then 30 g of methyl ethyl ketone and 0.9 g of 35% hydrochloric acid were placed in the reaction vessel. While maintaining the reaction system at 50 ° C., 38.1 g of 37% formalin was added dropwise over 30 minutes, and after completion of the addition, the mixture was further stirred for 60 minutes to promote a liquid-liquid heterogeneous reaction. While maintaining the temperature of the reaction system at the reaction temperature, the reaction system was allowed to stand to separate into two layers, and the lower aqueous phase was extracted. The organic phase is diluted with 200 g of methyl ethyl ketone, 100 g of water is added, and the reaction system is further stirred for 30 minutes while maintaining the same temperature as during the reaction. A methyl ethyl ketone solution of resorcin formalin resin was obtained. The resulting methyl ethyl ketone solution of the ketone-modified resorcin formalin resin was diluted with 400 g of methyl ethyl ketone and dehydrated by distillation at an azeotropic temperature of water and methyl ethyl ketone. Next, the solution was cooled to room temperature and filtered to obtain a methyl ethyl ketone solution of a ketone-modified resorcin formalin resin. The resulting methyl ethyl ketone solution of the ketone-modified resorcin formalin resin is put into the reaction vessel again, 200 g of water is added and distilled at an azeotropic temperature, methyl ethyl ketone is removed, the amount of water is reduced, and the target solid content is reduced. 138 g of a ketone-modified resorcin formalin resin aqueous solution having an appropriate fluidity of 60% was obtained. This ketone-modified resorcin formalin resin aqueous solution having a solid content of 60% is a ketone-modified resorcin formalin resin containing no inorganic salt and having a reduced resorcin formalin resin content of resorcin monomer and resorcin pentanuclear or higher.

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 3.4%
Resorcin dinuclear ... 15.3%
Resorcin trinuclear ... 16.3%
Resorcin tetranuclear ... 13.8%
More than resorcin 5 nucleus ... 51.2%

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

[Example 2]
266 g of water, 266 g of calcium chloride and 73.8 g of resorcin were placed in a 1 liter glass Kolben, dissolved at 50 ° C., and then 30 g of methyl ethyl ketone and 0.9 g of 35% hydrochloric acid were placed in the reaction vessel. While maintaining the reaction system at 50 ° C., 33.0 g of 37% formalin was added dropwise over 30 minutes, and after completion of the addition, the mixture was further stirred for 60 minutes to promote a liquid-liquid heterogeneous reaction. While maintaining the temperature of the reaction system at the reaction temperature, the reaction system was allowed to stand to separate into two layers, and the lower aqueous phase was extracted. The organic phase is diluted with 200 g of methyl ethyl ketone, 100 g of water is added, and the reaction system is further stirred for 30 minutes while maintaining the same temperature as during the reaction. A methyl ethyl ketone solution of resorcin formalin resin was obtained. The resulting methyl ethyl ketone solution of the ketone-modified resorcin formalin resin was diluted with 400 g of methyl ethyl ketone and dehydrated by distillation at an azeotropic temperature of water and methyl ethyl ketone. Next, the solution was cooled to room temperature and filtered to obtain a methyl ethyl ketone solution of a ketone-modified resorcin formalin resin. The resulting methyl ethyl ketone solution of the ketone-modified resorcin formalin resin is put into the reaction vessel again, 200 g of water is added and distilled at an azeotropic temperature, methyl ethyl ketone is removed, the amount of water is reduced, and the target solid content is reduced. 136 g of an aqueous ketone-modified resorcin formalin resin solution having an appropriate fluidity of 60% was obtained. This ketone-modified resorcin formalin aqueous solution having a solid content of 60% is a ketone-modified resorcin formalin resin containing no inorganic salt and having a reduced resorcin formalin resin content of resorcin monomers and resorcin pentanuclear or more.

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 analysis conditions were the same as those in Example 1, and the obtained chromatogram is shown in FIG. The peak area ratio of the obtained chromatogram was as follows.
Resorcinol: 5.8%
Resorcin dinuclear ... 16.8%
Resorcin trinuclear ... 13.9%
Resorcin tetranuclear ... 12.6%
More than resorcin 5 nucleus ... 50.9%

[Example 3]
In 500 ml glass Kolben, 133 g of water, 85 g of calcium chloride, and 111 g of resorcin were added and dissolved at 50 ° C., and then 45 g of methyl ethyl ketone and 0.45 g of 35% hydrochloric acid were placed in the reaction vessel. While maintaining the reaction system at 50 ° C., 53 g of 37% formalin was added dropwise over 30 minutes, and after completion of the addition, the mixture was further stirred for 30 minutes to proceed a liquid-liquid heterogeneous reaction. While maintaining the temperature of the reaction system at the reaction temperature, the reaction system was allowed to stand to separate into two layers, and the lower aqueous phase was extracted. The organic phase is diluted with 200 g of methyl ethyl ketone, 100 g of water is added, and the reaction system is further stirred for 30 minutes while maintaining the same temperature. After standing, it is separated into two layers, the aqueous phase is extracted, and a ketone-modified resorcin formalin resin is obtained. A methyl ethyl ketone solution was obtained.
200 g of water was added to the methyl ethyl ketone solution of the resulting ketone-modified resorcin formalin resin and distilled at an azeotropic temperature to remove methyl ethyl ketone and reduce the amount of water, so that the target solid content was about 50%. 260 g of a ketone-modified resorcin formalin aqueous solution having fluidity was obtained. This aqueous solution of ketone-modified resorcin formalin having a solid content of about 50% does not contain an inorganic salt, and is a ketone-modified resorcin formalin resin with a reduced content of resorcin formalin resin of resorcin monomer and resorcin pentanuclear.

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 analysis conditions were the same as those in Example 1, and the obtained chromatogram is shown in FIG. The peak area ratio of the obtained chromatogram was as follows.
Resorcinol 7.9%
Resorcin dinuclear ... 19.7%
Resorcin trinuclear ... 18.6%
Resorcin 4 nucleus ... 14.4%
More than resorcin 5 nucleus ... 39.4%

[Comparative Example 1]
In a 2-liter three-necked flask, 265 g of water, 170 g of calcium chloride, and 63 g of resorcin were dissolved at 50 ° C., and then 0.8 g of 35% hydrochloric acid was placed in the reaction vessel. While maintaining the reaction system at 50 ° C., 26 g of 37% formalin was added dropwise over 5 hours, and after completion of the addition, the mixture was further stirred for 1 hour to promote a solid-liquid heterogeneous reaction. The produced resorcinol polynuclear product became a gum and entangled with a stirring bar, and the post-treatment was very troublesome. After discarding the aqueous phase, the gum-like substance was washed with 400 g of 39% calcium chloride aqueous solution. After removing the washing liquid, the gum-like substance was dried under reduced pressure, dissolved with 240 g of methyl ethyl ketone, insolubles were filtered off, and dried again under reduced pressure. Compared to the reaction of the example, a much longer reaction time was required. From the above, it was judged difficult to expand this reaction to an industrial scale.

[Comparative Example 2]
In a 1-liter three-necked flask, 150 g of water and 63 g of resorcin were added and dissolved at 50 ° C., and then 0.8 g of 35% hydrochloric acid was placed in the reaction vessel. While maintaining the reaction system at 50 ° C., 26 g of 37% formalin was added dropwise over 5 hours, and after completion of the addition, the reaction was further stirred for 1 hour. After discarding the aqueous phase, it was washed with 400 g of water. After removing the washing solution, it was dried under reduced pressure, dissolved with 240 g of methyl ethyl ketone, filtered to remove insoluble matter, and dried again under reduced pressure. Although an attempt was made to dissolve water by adding water to the reaction product, it could not be made into an aqueous solution. This is presumably because the content of resorcin formalin resin having five or more nuclei is high.

The ketone-modified resorcin formalin resin obtained in the present invention does not contain an inorganic salt, and both the resorcin monomer content and the resorcin formalin resin content of the resorcin pentanuclear or more are reduced. It has good fluidity, and does not sublime unreacted resorcin when using an adhesive and does not deteriorate the working environment. It is useful as an adhesive for rubber and hose.

2 is a gel permeation chromatograph of the resin obtained in Example 1. FIG. 3 is a gel permeation chromatograph of the resin obtained in Example 2. FIG. 4 is a gel permeation chromatograph of the resin obtained in Example 3. FIG.

Claims (8)

20 to 150 parts by weight of resorcin (A) is added to 100 parts by weight of water in an aqueous solvent, and 20 to 80 parts by weight of inorganic salt (B) is added to 100 parts by weight of water,
10 to 200 parts by weight of an organic solvent (C) represented by the following general formula [1], which dissolves resorcin formalin resin and has a solubility parameter of 7.5 to 11.0, relative to 100 parts by weight of resorcin (A) Add,
Stir at a liquid temperature below the boiling point of the organic solvent (C) to give a two-phase system with no solids remaining,
While adding a catalytic amount of an organic acid or inorganic acid (D) and maintaining the reaction system at 0 to 60 ° C., 1 to 40% formalin (E) is converted to formaldehyde / resorcin = 0 with respect to resorcin (A). as .3~0.8mol ratio, viewing including the step of dropping under stirring,
The inorganic salt (B) is one or more cations selected from alkali metals and alkaline earth metals, sulfate ions, nitrate ions, chlorine ions, bromine ions, iodine ions or thiocyanic acid. A salt composed of one or more anions selected from ions, dissolved in 20 to 80 parts by weight with respect to 100 parts by weight of the water,
A method for producing a ketone-modified resorcin formalin resin, wherein the organic solvent (C) represented by the general formula [1] is used for modifying a reaction solvent that forms a liquid-liquid heterogeneous system with water and a resorcin formalin resin.

[Wherein R ₁ and R ₂ may be the same or different, and are methyl group, ethyl group, n-propyl group, 2-propyl group, n-butyl group, secondary butyl group, isobutyl group or tertiary butyl group. Represents. ]   The manufacturing method according to claim 1, wherein the organic solvent (C) represented by the general formula [1] has a solubility parameter of 9.0 to 11.0. The production according to claim 1 or ₂ , wherein the group R ₁ in the general formula [1] of the organic solvent (C) represented by the general formula [1] is a methyl group and R ₂ is an ethyl group. Method.   The manufacturing method according to any one of claims 1 to 3, wherein the organic solvent (C) represented by the general formula [1] is an organic solvent that dissolves 1 g or more of the resorcin formalin resin per 100 g.   5. The production method according to claim 1, wherein the organic solvent (C) represented by the general formula [1] is used as a mixture of two or more kinds. The manufacturing method according to any one of claims 1 to 5 , wherein the inorganic salt (B) is calcium chloride. The manufacturing method according to any one of claims 1 to 6 , wherein the organic acid or inorganic acid (D) is hydrochloric acid. Formaldehyde number of moles of the the formalin (E) is, with respect to the number of moles of resorcinol (A), formaldehyde / resorcinol = 0.5～0.8Mol ratio claims 1 to 7 either claim The manufacturing method as described in.

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