JP2013173729A - Trisphenol methanes, method of producing the same and use of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide low color trisphenol methanes, a method of producing the same and use of the same.SOLUTION: When phenols and aromatic hydroxy aldehydes are reacted with each other by using acid catalyst under heat, the reaction is performed at a temperature of 100°C or less from the start of the reaction until a reaction rate reaches 90%, subsequently, the temperature is raised and the reaction is performed at a temperature more than 100°C and 130°C or less in order to produce trisphenol methanes. Thereby, the trisphenol methanes having a Gardner color scale of 9 or less (as a 0.5 mass% THF solution) and further a low color epoxy resin can be obtained.

Description

  The present invention relates to trisphenolmethanes with little coloring, a method for producing the same, and uses thereof.

  Trisphenol methane has been used for paints and printed wiring board materials, particularly as a raw material for producing a heat-resistant epoxy resin or a curing agent thereof. Trisphenol methanes are heating reaction products of phenols and aromatic hydroxy aldehydes under an acid catalyst. Usually, phenols and aromatic hydroxy aldehydes are reacted with an acid catalyst such as p-toluenesulfonic acid. It is obtained by heating at a predetermined temperature (for example, 105 ° C.) under a nitrogen stream (see Patent Document 1).

  In the process of the heating reaction, trisphenolmethanes colored in red (having a large Gardner color number) may be obtained due to side reactions such as heating or oxidation reaction by contact with air. The coloring of trisphenolmethanes has a problem that the color tone of the epoxy resin using the trisphenolmethanes is deepened and the use thereof is limited.

JP 2008-184417 A

  An object of the present invention is to provide a production method capable of obtaining trisphenolmethanes with little coloration after heating reaction of phenols and aromatic hydroxyaldehydes, the trisphenolmethanes, and uses thereof. is there.

The reaction under the acid catalyst between phenols and aromatic hydroxy aldehydes is difficult to proceed at a heating temperature of 100 ° C. or less even if the heating time is prolonged, and a sufficient reaction rate cannot be obtained. Usually, it is necessary to heat at a predetermined temperature of 100 ° C. or higher (typically, 105 ° C.). The present inventor examined such a heating reaction, and in the reaction system, firstly obtained knowledge that an easily oxidizable unstable reaction intermediate was generated in the initial stage of the reaction. Based on this, if the reaction is allowed to proceed while suppressing the oxidation of the unstable reaction intermediate by controlling the heating at the initial reaction to a low temperature of 100 ° C. or lower, It has been found that the proportion of the reaction intermediate is reduced and the proportion of the stable reaction product which is relatively difficult to oxidize is increased. Therefore, after reaching such a reaction rate, it is possible to increase the heating temperature to advance the reaction, and to obtain trisphenolmethanes with little coloration at a desired reaction rate with less risk of by-product formation of oxides. I found.
In the reactor, the contact surface with the reaction system is made of a material that does not contain a transition metal or has no possibility of elution. It has also been found that it is suitable for avoiding coloring. Based on these findings, the following invention is provided.

In the present invention, when phenols and aromatic hydroxyaldehydes are reacted under heating under an acid catalyst to produce trisphenolmethanes,
A process for producing trisphenolmethanes, which is carried out at a temperature of 100 ° C. or lower from the beginning of the reaction until the reaction rate reaches 90%, and then heated to a temperature of more than 100 ° C. and 130 ° C. or lower. I will provide a.
In the above, the final reaction rate is desirably 98% or more.
The reactor used in the above method preferably has at least one material selected from the group consisting of glass, hastelloy and titanium as the contact surface with the reaction system.

Moreover, this invention can provide the trisphenol methane whose Gardner color number measured as a 0.5 mass% tetrahydrofuran solution is 9 or less.
Such trisphenolmethanes with little coloration can be obtained by the above method.
In the present invention, the trisphenolmethanes preferably have a transition metal content of 300 mass ppm or less.

Furthermore, the present invention can provide an epoxy resin obtained from the above trisphenolmethanes and having a Gardner color number of 7 or less measured as a 0.5 mass% tetrahydrofuran solution.
The above trisphenolmethanes can also be used as a curing agent for epoxy resins.

  In the present invention, trisphenolmethanes with less coloring during the production process can be easily obtained by controlling the heating temperature, more preferably by selecting the reactor material. From such trisphenolmethanes, it is possible to obtain an epoxy resin with little coloration, which is useful as a raw material or curing agent for heat-resistant epoxy resins, and for paint and printed wiring board materials without any restrictions based on coloration. Can be used.

Hereinafter, the present invention will be described in detail according to a method for producing trisphenolmethanes.
The reaction raw material phenols and aromatic hydroxy aldehydes can select the position of the hydroxy group with respect to methine according to the structure of the target trisphenol methane, and have various substituents without any particular limitation. Can do.
Examples of phenols include phenol, m-cresol, o-cresol, p-cresol, β-naphthol, α-naphthol, dihydroxynaphthol and the like. Among these, phenol is available at a low cost.
Examples of the aromatic hydroxyaldehydes include salicylaldehyde (o-hydroxybenzaldehyde) and p-hydroxybenzaldehyde.

  When methane-type trisphenol is produced by reaction of phenols with aromatic hydroxy aldehydes, phenols are usually used twice or more (molar ratio) with respect to aromatic hydroxy aldehydes. The charging ratio (molar ratio) of the phenols / aromatic hydroxyaldehydes can be changed to some extent according to the desired trisphenolmethanes, but if the charging ratio is small, the softening point of the trisphenolmethanes is high. When the charging ratio is large, the softening point tends to be low. If the softening point is too high, it is difficult to take out the product from the reaction apparatus. On the other hand, if the softening point is too low, it is difficult to use the epoxy resin as a raw material. 2 to 30 are preferable, and 2.5 to 20 are more preferable. Within this range, trisphenolmethanes having a desired softening point can be produced by varying the charging ratio.

  More specifically, for example, when phenol and salicylaldehyde are used as reaction raw materials, trisphenol methanes having a softening point of 100 ° C. to 110 ° C. are selected when the charging ratio is selected in the range of 10 to 16. When the charge ratio is in the range of 4 to 6, trisphenolmethanes having a softening point of 120 ° C to 135 ° C are obtained. Moreover, when the phenol / aromatic hydroxyaldehyde feed ratio is in the range of 2 to 3, trisphenolmethanes having a softening point of 135 ° C to 150 ° C can be obtained.

Examples of the acid catalyst usually include p-toluenesulfonic acid, oxalic acid, sulfuric acid, hydrochloric acid, acetic acid and the like. Among these, p-toluenesulfonic acid is preferable because of its excellent reactivity.
The catalyst amount is in the range of 0.05 to 20% by mass, preferably 0.2 to 5% by mass, based on the charged amount of aromatic hydroxyaldehydes. If the amount of catalyst is less than this range, the progress of the reaction will be slow. On the other hand, if the amount of catalyst is more than this range, elution of Fe, Cr, Ni, etc. will be large when a stainless steel reaction vessel or pipe is used. It is not preferable.

In the present invention, the temperature of the reaction is controlled based on the reaction rate. Here, the reaction rate is usually the reaction rate of aromatic hydroxyaldehydes as a reaction raw material, and the residual amount of aromatic hydroxyaldehydes in the reaction system is measured using a gel permeation chromatograph (GPC). Thus, it can be obtained from the area%.
The reaction is carried out at a temperature of 100 ° C. or lower, preferably 70-100 ° C., until the reaction rate is 90% or lower. After the reaction rate exceeds 90%, the reaction is carried out at a temperature exceeding 100 ° C. and 130 ° C. or less, preferably 105 to 125 ° C., more preferably 110 to 125 ° C. When the reaction is carried out at a low temperature of 100 ° C. or less up to a reaction rate of 90% in this way, the oxidation of the easily oxidizable unstable reaction intermediate produced at the beginning of the reaction is suppressed. When the reaction rate exceeds 90%, the proportion of unstable reaction intermediates decreases, and the proportion of stable high molecular weight substances that are relatively difficult to oxidize increases. Therefore, the reaction temperature is increased and the reaction rate is increased. It is preferable from the viewpoint of productivity. When carried out under such reaction conditions, trisphenolmethanes having good color tone and good reaction rate can be obtained.

  The heating time for the former stage is usually 3 to 15 hours, and the heating time for the latter stage is usually 1 to 10 hours. Under such heating conditions, a reaction rate of 98% or more can finally be achieved by subsequent heating.

In addition, in the above reaction, when a metal reactor having little corrosion resistance is used, the content of transition metals such as Fe, Cr, Ni and the like increases due to acid corrosion caused by an acid catalyst such as p-toluenesulfonic acid. Phenolmethanes are easily colored. In the present invention, the content of the transition metal of trisphenolmethanes is preferably 300 ppm by mass or less, more preferably 250 ppm by mass or less. The content of the transition metal can be analyzed by inductively coupled plasma mass spectrometry.
Therefore, in the present invention, it is preferable that the inner surface of the reaction apparatus such as a reactor or piping, that is, the contact surface with the reaction system is a material having high corrosion resistance. Specifically, glass, hastelloy, titanium, or glass lining is applied. It is preferable to use a reactor that has been prepared. By using such a reactor, a low value of the transition metal content can be achieved.

After reaching a predetermined reaction rate by the latter heating, a catalyst neutralizing agent is added to deactivate the catalyst and stop the reaction. In the present invention, the catalyst neutralizing agent is not particularly limited as long as it is an alkaline compound, and preferred examples include sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, calcium carbonate, lithium hydroxide and the like.
The addition amount of the catalyst neutralizing agent is not particularly limited, but is usually 0.9 to 1.1 equivalents, preferably 1.0 equivalents, relative to the catalyst.
Although it is possible to add the catalyst neutralizing agent at the reaction temperature of the latter stage, it is usually desirable that the catalyst neutralizing agent is once cooled to 70 ° C to 90 ° C, preferably 75 ° C to 85 ° C. By adding at such a temperature, heat generation due to the neutralization reaction can be suppressed, and the reaction can be performed safely.

After the reaction is completed, it is desirable to remove phenols as much as possible among unreacted raw materials. If there is a large amount of residual phenols, the phenol is dissolved in the epoxidation reaction solvent such as dimethyl sulfoxide in the process of producing an epoxy resin from trisphenol methane, and the phenol is in the solvent in the process of recycling the solvent. In other words, it is difficult to recycle the solvent, the number of times the solvent is recycled is reduced, and the cost is increased.
For this reason, it refine | purifies so that the residual amount of phenols in trisphenol methane may become 1 mass% or less normally, Preferably it is 0.5 mass% or less.

This purification can be performed by vacuum distillation or steam distillation. Specifically, in the case of vacuum distillation, usually, the temperature was raised to about 120 to 170 ° C. in advance, and the reaction product was subjected to atmospheric distillation, and phenol removal possible by atmospheric distillation was sufficiently performed. Thereafter, the pressure is gradually reduced to about 20 torr (2.7 kPa), and this degree of pressure reduction is maintained for 10 minutes to 3 hours, preferably 20 minutes to 2 hours.
In the case of steam distillation, the reaction temperature is raised to about 105 ° C. to 150 ° C., steam is introduced into the reaction vessel, and phenol is azeotropically distilled. When performing steam distillation, the inside of the reaction vessel may be decompressed.
Among these, a preferable distillation method is steam distillation, and since azeotropic distillation of phenols and steam occurs, phenol can be removed at a low temperature. Thereby, trisphenol methanes with little residual phenol, little coloring, and especially few thermal decomposition by-products can be obtained.

  After the distillation is complete, the purified trisphenolmethanes can be recovered in a molten state, cooled and solidified, and then pulverized to an appropriate size.

  According to the present invention, trisphenol methanes having a Gardner color number of 9 or less can be provided. In addition, an epoxy resin having a Gardner color number of 7 or less can be produced from such trisphenols. The Gardner color number is measured according to JISK0071-2 (1998). The Gardner color number in the present invention is a value as a 0.5% by mass THF solution of an object (trisphenolmethanes or epoxy resin).

  In the present invention, as described above, trisphenolmethanes are a reaction product obtained by heating phenols and aromatic hydroxyaldehydes under an acid catalyst. Therefore, although the trisphenolmethanes provided in the present invention differ depending on the respective conditions in the above reaction, usually, mainly two phenol skeletons (a) derived from phenols and phenol skeletons derived from aromatic hydroxyaldehydes ( b) A mixture containing tris (hydroxyphenyl) methane (methane type trisphenol monomer) having a structure in which one is bonded to methine and a high molecular weight compound. The high molecular weight product is, for example, a dimer containing 2 phenol skeletons (b) and 3 phenol skeletons (a), or 3 containing 3 phenol skeletons (b) and 4 phenol skeletons (a). Such as a mass.

Trisphenol methanes have different softening points depending on the content of monomers, dimers, trimers and the like. Trisphenol methane having a relatively low softening point of about 100 ° C. to 130 ° C. is used, for example, as a raw material for epoxy resin for semiconductor encapsulants, and has a relatively high softening point of about 140 ° C. to 155 ° C. The kind is used as a raw material of an epoxy resin for solder resist, which is a heat-resistant coating agent for printed circuit boards, for example.
In addition, the softening point used by this invention is when it measures at a temperature increase rate of 5 degree-C / min using the ring and ball type softening point measuring apparatus (25D5-ASP-MG type | mold made by Meitec Co., Ltd.) described in JISK2425. Softening point.

Examples of the present invention will be shown below. However, these examples are examples for explaining the present invention more specifically, and should be understood not to limit the scope of the present invention.
Example 1
<Production of Tristrisphenolmethanes>
In a 1 liter glass reaction vessel (separable flask) equipped with a stirrer, thermometer, reflux device, inert gas inlet tube, oil bath, phenol 659 g (7 mol), salicylaldehyde 61 g (0.5 mol), p -Charged 1.425 g of toluenesulfonic acid (1.5 mol% with respect to salicylaldehyde).
While bubbling nitrogen from the inert gas introduction tube, the reaction temperature was raised to 95 ° C. and reacted for 4 hours. The reaction rate at that time was 90% from the measurement result of salicylaldehyde by GPC.
Thereafter, the reaction temperature was raised to 105 ° C. and reacted for 2 hours. The reaction rate was 98%.
After completion of the reaction, the temperature was lowered to 80 ° C., and 0.315 g of lithium hydroxide hydrate (1 equivalent to the catalyst) was added to neutralize the catalyst. The contents were then transferred to a 1 liter stainless steel reactor, a distillation apparatus was attached, the reaction temperature was raised to 170 ° C., unreacted phenol was removed, and the pressure was reduced to 20 torr with a vacuum pump. Distilled under reduced pressure for 1 hour. After completion of the distillation, the reaction temperature was lowered to 150 ° C., the reaction product was taken out in a molten state, cooled and solidified, and then pulverized.
The metal content of the trisphenolmethanes was measured by inductively coupled plasma mass spectrometry. The results are shown in Table 1. This trisphenolmethane was dissolved in tetrahydrofuran (THF) to prepare a 0.5 mass% THF solution, and the color tone was examined. The Gardner color number of this solution was 5.

<Manufacture of epoxy resin>
Dissolve 92.5 g of the trisphenolmethanes obtained above and 27.5 g of epichlorohydrin in dimethyl sulfoxide, add 10.0 g of sodium hydroxide, and react at 40 ° C. for 2 hours and at 70 ° C. for 1 hour. did. Thereafter, dimethyl sulfoxide was removed by distillation under reduced pressure, methyl isobutyl ketone and sodium hydroxide were added and reacted at 70 ° C. for 1 hour. Then, it washed with water, NaCl produced | generated in the water layer was removed, the oil layer was collect | recovered, and methyl isobutyl ketone was distilled under reduced pressure at 70 degreeC.
The obtained epoxy resin had a Gardner color number of 3.

(Example 2)
In Example 1, the reaction temperature was raised to 85 ° C. and reacted for 7 hours (reaction rate: 93%). Thereafter, the reaction temperature was raised to 120 ° C. and reacted for 5 hours (reaction rate: 99.3). %), Trisphenol methanes and epoxy resin were obtained in the same manner as in Example 1.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

(Example 3)
In Example 1, trisphenolmethanes and an epoxy resin were obtained in the same manner as in Example 1 except that the reaction vessel was replaced with a stainless steel reaction vessel.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

(Comparative Example 1)
In Example 1, trisphenolmethanes and an epoxy resin were obtained in the same manner as in Example 1 except that “the reaction was performed at 105 ° C. for 6 hours”. That is, in Comparative Example 1, only the first stage reaction was performed, and the second stage reaction was not performed.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

Example 4
In Example 1, trisphenolmethanes and an epoxy resin were obtained in the same manner as in Example 1 except that the reaction conditions in the first and second stages were changed as shown in Table 1.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

(Example 5)
In Example 1, trisphenolmethanes and an epoxy resin were obtained in the same manner as in Example 1 except that the reaction vessel was replaced with a Hastelloy reaction vessel.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

(Example 6)
In Example 1, trisphenolmethanes and an epoxy resin were obtained in the same manner as in Example 1 except that the reaction vessel was replaced with a titanium reaction vessel.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

(Comparative Example 2)
In Example 1, trisphenolmethanes and an epoxy resin were obtained in the same manner as in Example 1 except that the reaction conditions in the first stage were changed as shown in Table 1.
Table 1 shows the metal content and the Gardner color number of the trisphenolmethanes and the Gardner color number of the epoxy resin.

  As shown above, the trisphenol methanes of the examples had a smaller Gardner color number and less coloring than the trisphenol methanes of the comparative examples. Moreover, the epoxy resin using the trisphenols of the present invention was also less colored. Therefore, when the trisphenol methane of the present invention is used as a raw material for an epoxy resin, an epoxy resin useful as a raw material for electronic members and paints can be obtained.

Claims (6)

When producing trisphenolmethanes by reacting phenols and aromatic hydroxyaldehydes with heating under an acid catalyst,
A process for producing trisphenolmethanes, which is carried out at a temperature of 100 ° C. or lower from the beginning of the reaction until the reaction rate reaches 90%, and then heated to a temperature of more than 100 ° C. and 130 ° C. or lower. .   The method according to claim 1, wherein a reaction device made of at least one material selected from glass, hastelloy, and titanium is used as a contact surface with the reaction system.   The method according to claim 1 or 2, wherein the final reaction rate is 98% or more.   Trisphenol methanes having a Gardner color number of 9 or less measured as a 0.5 mass% tetrahydrofuran solution.   The trisphenol methane according to claim 4, wherein the content of the transition metal is 300 mass ppm or less.   An epoxy resin obtained from the trisphenolmethanes according to claim 4 or 5 and having a Gardner color number of 7 or less measured as a 0.5 mass% tetrahydrofuran solution.