JP5087231B2 - Method for producing ketone-modified resorcin formalin resin - Google Patents

Description

The present invention reduces both the resorcin monomer content and the resorcin formalin resin content of resorcin pentanuclear and higher by the resorcin formalin resin after synthesis of the ketone adduct by reaction of resorcin and liquid ketone, The present invention relates to a method for producing a ketone-modified resorcin formalin resin that has excellent adhesiveness and is less likely to sublime unreacted resorcin when using an adhesive.

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). In a method for producing an aldehyde resin to be used as an adhesive for water-repellent paper products such as corrugated cardboard, in the examples, the first stage reaction is performed with formaldehyde and methyl ethyl ketone, and the second stage reaction is performed with the product and resorcin, 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 production method in which all steps are carried out in the same reaction vessel, and has an appropriate fluidity when it is made into an aqueous solution, and the resorcin monomer content and resorcin pentanuclear body are not required without an extraction step. It aims at providing the manufacturing method of the ketone modified resorcin formalin resin which reduced both content of the above-mentioned ketone modified resorcin formalin resin and resorcin formalin resin more than a resorcin pentanuclear body.

In the present invention, the peak area corresponding to the resorcin monomer is 3 to 9% with respect to the entire peak area obtained by gel permeation chromatography analysis of the resin (F), which corresponds to a resorcin pentanuclear or more. Is a method for producing a ketone-modified resorcin formalin resin having a peak area of 30% to 55%, wherein 10 to 40 parts by weight of water is added to 100 parts by weight of resorcin (A) and dissolved. The organic acid or inorganic acid (B) of the catalyst is dissolved by adding 0.01 to 2 parts by weight with respect to 100 parts by weight of resorcin (A), and the general formula [1] with respect to 100 parts by weight of resorcin (A). 3 to 45 parts by weight of a liquid ketone (C) represented by the formula is added dropwise over 1 to 480 minutes with stirring, the temperature is raised to 50 to 100 ° C., and the reaction is continued for 4 to 24 hours while maintaining this temperature. After the end, ~ 40% formalin (D) is 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). minutes stirring by reacting, after cooling, 1% to 30% aqueous ammonia (E) 1.0 to 2.0-fold molar added to an organic or inorganic acid (B) was neutralized, or the said This is a method for producing a ketone-modified resorcin formalin resin, which is a resin (F) obtained by further distilling off methanol contained in formalin after neutralization.

［式中、Ｒ１、Ｒ２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。］

[Wherein R1 and R2 may be the same or different and each represents a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, a secondary butyl group, an isobutyl group or a tertiary butyl group. . ]

  In this invention, when 1-40% formalin (D) is dripped with respect to resorcinol (A), it can also drop intermittently over 20-300 minutes under stirring.

In the present invention, with respect to 100 parts by weight of resorcin (A), 10 to 40 parts by weight of water is added and dissolved, and 0.01 to 2 parts by weight of organic acid or inorganic acid (B) as a catalyst is added and dissolved. Then, 3 to 45 parts by weight of the liquid ketone (C) represented by the general formula [1] is added dropwise with stirring for 1 to 480 minutes with respect to 100 parts by weight of resorcin (A), and water and the liquid ketone (C). The reaction is conducted for 4 to 24 hours at an azeotropic temperature of 1 to 40%, and after completion of the reaction, 1 to 40% formalin (D) is stirred at a formaldehyde / resorcin = 0.3 to 0.8 mol ratio with respect to resorcin (A). The solution was added dropwise over 1 to 300 minutes, and after completion of the addition, the mixture was further stirred for 20 to 90 minutes to react. After cooling, 1 to 30% aqueous ammonia (E) was added to the organic acid or inorganic acid (B). Resin obtained by adding 0.0 to 2.0 moles and neutralizing F) or a resin (F) obtained by further distilling off methanol contained in formalin after neutralization, and the final reaction product concentration is 30 to 80% by weight, and is used for an adhesive. In particular, the present invention is a method for producing a ketone-modified resorcin formalin resin, which has an appropriate fluidity.

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

Specific examples of the liquid ketone (C) represented by the general formula [1] include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Of these, methyl ethyl ketone in which R1 is a methyl group and R2 is an ethyl group is preferable. In the present invention, the liquid ketone (C) represented by the general formula [1] contributes to the modification of the resorcin formalin resin. The ketone-modified resorcin formalin resin produced by the production method of the present invention is considered to be improved in adhesion performance due to the ketone modification.

The method for producing a ketone-modified resorcin formalin resin of the present invention is characterized in that it is produced by a two-stage reaction by an addition reaction between resorcin and a ketone and a condensation reaction with formaldehyde. In the modification with a ketone, for example, in the case of methyl ethyl ketone, the molecular weight increase is 72 of the molecular weight of methyl ethyl ketone, or the molecular weight increase is 54 with 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 the advantage that ketone modification is easier to do. 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 (B) 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. Preference is given to p-toluenesulfonic acid and hydrochloric acid.

The method for producing a ketone-modified resorcin formalin resin of the present invention can perform all the steps in the same reaction vessel without including an extraction step, and the produced ketone-modified resorcin formalin resin has a resorcin monomer content and Both the content of ketone-modified resorcin formalin resin of resorcin pentanuclear and higher are reduced and the molecular weight is within the proper range, so it has appropriate fluidity when made into an aqueous solution and is not used when an adhesive is used. The reaction resorcin is not sublimated and the working environment is hardly deteriorated, and it has excellent adhesive force due to being modified with ketone.

  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

  The dropping time of formalin (D) performed under stirring 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 over 1 minute and stirred and mixed, and then the temperature was raised to 80 to 85 ° C. and reacted at this temperature for 8 hours. After completion of the reaction, 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 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 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 ketone-modified resorcin 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 (ketone adduct) appears after 30 minutes due to the ketone modification, and these components may newly improve the adhesion performance and the like.
(Compare with [Fig. 4].)

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, the reaction was further stirred for 4 hours. 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 a ketone-modified resorcin resin having a reduced resorcin formalin resin content of resorcin and resorcin pentanuclear (resorcin content is 8.6%, solids) 576 g).

In the same manner as in Example 1, 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 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%

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 mixed by stirring, and then the temperature was raised to 80 to 85 ° C. and the reaction was carried out at this temperature for 8 hours. 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. Next, water was added to adjust to a solid content of 50% by weight to obtain 1374 g of a ketone-modified resorcin resin having a reduced resorcin formalin resin content of resorcin and resorcin pentanuclear (resorcin content was 8.3%, solid Min 687 g).

In the same manner as in Example 1, 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 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, 1065 g of resorcin resin was obtained by adding water to adjust the solid content to 50% by weight (resorcin content is 15.3%, solid content is 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 those in Example 1, and the obtained chromatogram is shown in FIG. The peak area ratio of the obtained chromatogram was as follows.
Resorcinol ... 15.3%
Resorcin dinuclear body ... 18.3%
Resorcin trinuclear body ... 15.0%
Resorcin tetranuclear ... 12.0%
More than resorcin 5 nuclei ... 39.4%

The obtained resorcin formalin resin was subjected to liquid chromatography analysis. The obtained results are shown in FIG.

The method for producing a ketone-modified resorcin formalin resin of the present invention enables the resorcin content to be in the 8% range without an extraction step. Further, the produced ketone-modified resorcin formalin resin has an appropriate fluidity when it is made into an aqueous solution, and has a resorcin monomer content and a resorcinol resorcin formalin resin having a resorcin pentanuclear or higher and a resorcinol having a resorcin pentanuclear or higher. Since both the contents of the formalin resin are reduced, it is unlikely that unreacted resorcin will sublime when the adhesive is used, thereby deteriorating the working environment. 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.

2 is a gel permeation chromatograph of the ketone-modified resorcin formalin resin obtained in Example 1. FIG. 2 is a liquid chromatograph of the ketone-modified resorcin formalin resin obtained in Example 1. 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.

Claims (9)

The peak area corresponding to the resorcin monomer is 3 to 9% with respect to the entire peak area obtained by gel permeation chromatography analysis of the resin (F), and the peak area corresponding to the resorcin pentanuclear or more is A method for producing a ketone-modified resorcin formalin resin of 30% to 55%, in which 10 to 40 parts by weight of water is added to 100 parts by weight of resorcin (A) and dissolved to form an organic catalyst. The acid or inorganic acid (B) is dissolved by adding 0.01 to 2 parts by weight to 100 parts by weight of resorcin (A), and is represented by the general formula [1] with respect to 100 parts by weight of resorcin (A). 3 to 45 parts by weight of liquid ketone (C) was added dropwise with stirring over 1 to 480 minutes, the temperature was raised to 50 to 100 ° C., and the reaction was continued for 4 to 24 hours while maintaining this temperature. ~ 40% Lumarin (D) is added dropwise to resorcin (A) at a ratio of formaldehyde / resorcin = 0.3 to 0.8 mol over 1 to 300 minutes with stirring, and further stirred for 20 to 90 minutes after completion of the addition. reacted Te, after cooling, 1% to 30% aqueous ammonia (E) 1.0 to 2.0-fold molar added to an organic or inorganic acid (B) was neutralized, or after the neutralization further characterized and evaporated to a resin (F) der obtained by Turkey methanol contained in formalin, method for producing a ketone-modified resorcinol-formalin resin.

[Wherein R1 and R2 may be the same or different and each represents a methyl group, an ethyl group, an n-propyl group, a 2-propyl group, an n-butyl group, a secondary butyl group, an isobutyl group or a tertiary butyl group. . ] The aforementioned 1-40% formalin (D) is added dropwise intermittently over 20-300 minutes with stirring at a ratio of formaldehyde / resorcin = 0.3-0.8 mol to resorcin (A). The method for producing a ketone-modified resorcin formalin resin according to claim 1, wherein: With respect to 100 parts by weight of the aforementioned resorcin (A), 10 to 40 parts by weight of water is added and dissolved, and 0.01 to 2 parts by weight of organic acid or inorganic acid (B) as a catalyst is added and dissolved. A) 3 to 45 parts by weight of the liquid ketone (C) represented by the general formula [1] is added dropwise over 100 to 100 parts by weight over 1 to 480 minutes with stirring to azeotrope water and the liquid ketone (C). The reaction is carried out at a temperature below 4 to 24 hours, and after completion of the reaction, 1 to 40% formalin (D) is added to resorcin (A) at a ratio of formaldehyde / resorcin = 0.3 to 0.8 mol under stirring. -It is dripped over 300 minutes, and after completion | finish of dripping, it is made to react for 20-90 minutes, and after cooling, 1-30% aqueous ammonia (E) is 1.0-1.0 with respect to an organic acid or an inorganic acid (B) after cooling. It is a resin (F) obtained by adding 2.0 times mole and neutralizing Or a resin (F) obtained by further distilling off methanol contained in formalin after neutralization. The final reaction product concentration is 30 to 80% by weight, and it is suitable for use in an adhesive. The method for producing a ketone-modified resorcin formalin resin according to claim 1 or 2, characterized by having properties. In the liquid ketone (C) represented by the general formula [1], the group R1 in the general formula [1] is a methyl group, and R2 is an ethyl group. A method for producing a ketone-modified resorcin formalin resin according to any one of the above items. The liquid ketone (C) represented by the general formula [1] has an ability to dissolve 1 g or more of resorcin formalin resin in 100 g, according to any one of claims 1 to 4. A method for producing a ketone-modified resorcin formalin resin described in 1. 6. The liquid ketone (C) represented by the general formula [1] is used as a mixture of two or more liquid ketones represented by the general formula [1]. A method for producing a ketone-modified resorcin formalin resin according to any one of the above items. The method for producing a ketone-modified resorcin formalin resin according to any one of claims 1 to 6, wherein the organic acid or inorganic acid (B) 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). 7. A method for producing a ketone-modified resorcin formalin resin according to any one of 7 items. The method for producing a ketone-modified resorcin formalin resin according to any one of claims 1 to 8, wherein the dropping time of the formalin (D) is 20 to 120 minutes.

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