KR101267734B1 - Phenol-formaldehyde resin and method of manufacturing phenol-formaldehyde resin - Google Patents

Abstract

The phenol resin which can have transparency after hardening, and its manufacturing method are disclosed.
Method for producing a phenol resin according to the present invention comprises the steps of (a) dissolving phenol in aqueous formaldehyde solution; (b) adding phenol and formaldehyde in the presence of a catalyst to form a phenol resin intermediate; (c) removing the water contained in the result of step (b); (d) condensing the phenol resin intermediate to form a phenol resin at a temperature lower than the phenol resin curing temperature, wherein the phenol and formaldehyde are used in a molar ratio of 1: 1.4 to 1: 1.8. Characterized in that.

Description

Phenolic resin and its manufacturing method {PHENOL-FORMALDEHYDE RESIN AND METHOD OF MANUFACTURING PHENOL-FORMALDEHYDE RESIN}

The present invention relates to a phenol resin (phenol-formaldehyde resin) manufacturing technology, and more particularly to a phenol resin manufacturing method and apparatus for producing a phenol resin that can be suppressed discoloration so that it can be used for the purpose of coating, such as top coating of abrasive paper. .

Phenolic resin is a thermosetting resin with high mechanical strength, excellent heat resistance, and excellent electrical insulation, chemical resistance and adhesion. Due to these characteristics, phenol resins are used in various applications such as molding materials, adhesives, and laminate materials.

In addition, the phenol resin is also used as a coating material of abrasive paper due to its excellent heat resistance and wear resistance.

An object of the present invention is to provide a method for producing a phenol resin that can suppress discoloration in the curing process.

Another object of the present invention is to provide a phenol resin for forming a polishing paper top coating layer capable of maintaining transparency after curing.

Method for producing a phenol resin according to an embodiment of the present invention for achieving the above object (a) dissolving phenol in aqueous formaldehyde solution; (b) adding phenol and formaldehyde in the presence of a catalyst to form a phenol resin intermediate; (c) removing the water contained in the result of step (b); (d) condensation reaction of the phenol resin intermediate to form a phenol resin at a temperature lower than the phenol resin curing temperature, wherein the phenol and formaldehyde are used in a molar ratio of 1: 1.4 to 1: 1.8. It is characterized by.

At this time, the catalyst is preferably added at 1.5 to 3.0% by weight based on 100% by weight of the phenol.

In addition, the step (b) is preferably carried out at 85 ~ 90 ℃.

The phenol resin according to the embodiment of the present invention for achieving the above object is a phenol resin for forming a top coating layer of abrasive paper, characterized in that the residual phenol is contained in 0.7% by weight or less.

Figure 1 schematically shows a method for producing a phenol resin according to an embodiment of the present invention.
Figure 2 schematically shows the apparatus used in the embodiment of the present invention in phenol dissolution and phenol resin intermediate formation tablets.
Figure 3 shows the content of phenol and formaldehyde remaining in the phenol resin intermediate layer according to the amount of phenol and formaldehyde used in the embodiment of the present invention.
Figure 4 shows the reaction time according to the amount of catalyst in the embodiment of the present invention.
5 shows the reaction time according to the reaction temperature in the embodiment of the present invention.
Figure 6 shows the results of the FT-IR analysis of the phenol resin prepared according to the embodiment of the present invention.
Figure 7 shows the abrasive paper formed with the top coating layer from the phenol resin prepared according to the embodiment of the present invention.

The features of the present invention and the method for achieving the same will be apparent from the accompanying drawings and the embodiments described below. However, the present invention is not limited to the embodiments described below, but may be embodied in various forms. The present embodiments are provided so that the disclosure of the present invention is complete and that those skilled in the art will fully understand the scope of the present invention. The invention is only defined by the description of the claims.

Hereinafter, a phenol resin and a method for manufacturing the same according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 schematically shows a method for producing a phenol resin according to an embodiment of the present invention.

1, the phenol resin manufacturing method according to an embodiment of the present invention is a phenol dissolving step (S110), phenol resin intermediate formation step (S120) by the addition reaction, water removal step (S130) and phenol by the condensation reaction It includes a resin forming step (S140).

Phenolic Soluble

In the phenol dissolving step (S110), phenol is dissolved in an aqueous solution of formaldehyde.

Formaldehyde aqueous solution may be used that contains about 30 to 60% by weight of formaldehyde, formaldehyde may be used as an aqueous solution containing 37% by weight of formaldehyde as widely used.

At this time, it is preferable to use the usage-amount of a phenol and formaldehyde in the ratio of 1: 1.4-1: 1.8 by phenol: formaldehyde molar ratio.

If the amount of formaldehyde per mole of phenol is less than 1.4 moles, the amount of unreacted phenol increases in the phenol resin intermediate forming step described later. If the amount of such unreacted phenol is large, there is a problem in that it acts as a factor of discoloration in the phenol resin curing process, it can not secure transparency.

Conversely, when the amount of formaldehyde used per mole of phenol exceeds 1.8 moles, the amount of unreacted toxic formaldehyde increases without increasing the effect of reducing unreacted phenol in the phenol resin intermediate formation step.

Phenolic Resin Intermediates Formation

Next, in the phenol resin intermediate forming step (S120), the phenol and formaldehyde are added to form an phenol resin intermediate.

At this time, this step is carried out in the presence of a catalyst. Triethylamine may be used as the catalyst. Such triethylamine contributes to shortening of reaction time.

The catalyst is preferably added at 1.5 to 3.0% by weight based on 100% by weight of phenol. When the amount of the catalyst used is less than 1.5% by weight based on 100% by weight of phenol, it did not contribute to shortening the reaction time. On the contrary, when the amount of the catalyst exceeds 3.0% by weight based on 100% by weight of phenol, it was difficult to obtain a further reaction time shortening effect.

In addition, this step (S120) is preferably carried out at a reaction temperature of 85 ~ 90 ℃. As a result of the experiment, when the reaction temperature was lower than 85 ° C., the reaction time took more than 10 hours and as much as 20 hours. On the other hand, when the reaction temperature exceeds 90 ℃ solution stability may be a problem.

On the other hand, when the reaction temperature is 85 ~ 90 ℃, the reaction time was shortened to several hours and solution stability was also maintained. In particular, when the reaction temperature is 90 ℃, the reaction time was shortened to approximately 4 to 5 hours.

This step (S120) corresponds to an addition reaction in which three methyl groups are added to phenol, and the phenol resin intermediate formed as a result of the addition reaction was trimethylolphenol represented by Chemical Formula 1 below.

[Formula 1]

The result of this step (S120) includes the phenol resin intermediate trimethylolphenol, water, unreacted phenol and formaldehyde.

Water removal

Next, in the water removal step (S130) to remove the water contained in the product of the above-described phenol resin intermediate forming step (S120).

More specifically, in order to remove the water, the resultant of the phenol resin intermediate forming step (S120) at room temperature of about 10 ~ 30 ℃ is left for about one day. As a result, the phenol resin intermediate and water are separated into layers, a phenol resin intermediate layer is formed at the lower portion, and a water layer is formed at the upper portion. Water is removed from the resulting layered product.

Then, with respect to the phenol resin intermediate layer, the amount of unreacted phenol was measured, it was found to be 7.5 to 8.5% by weight of the total weight of the intermediate layer. This corresponds to the result of using the amount of phenol and formaldehyde in a molar ratio of 1: 1.4 to 1: 1.8 in the present invention.

Phenolic Resin Formation

Next, in the phenol resin forming step (S140), at a temperature lower than the phenol resin curing temperature, the phenol resin intermediate is condensed to form a phenol resin.

In this step, the phenol resin represented by the formula (2) is formed.

[Formula 2]

In addition, in this step, residual phenol, residual formaldehyde, residual water and water produced by the condensation reaction are removed by evaporation or the like.

To this end, this step (S140) is preferably carried out at a reaction temperature of 100 ~ 120 ℃. When the reaction temperature of this step is less than 100 degreeC, the removal effect, such as a residue, is low. On the contrary, when the reaction temperature of this step exceeds 120 ° C, the phenol resin to be formed is not preferable because curing can proceed.

The phenol resin produced through the above process was 0.6 ~ 0.69% by weight of the residual phenol, 0.7 wt% or less appeared.

After curing the prepared phenol resin, the color was observed, the color was almost transparent.

Therefore, the phenol resin according to the present invention can maintain transparency during curing together with the heat resistance and abrasion resistance of the phenol resin itself, and can be utilized for applications such as forming a top coating layer of abrasive paper.

Example

Hereinafter, the configuration and operation of the present invention through the preferred embodiment of the present invention will be described in more detail. It is to be understood, however, that the same is by way of illustration and example only and is not to be construed in a limiting sense.

Details that are not described herein will be omitted since those skilled in the art can sufficiently infer technically.

1. Reagent and Experiment Device

(1) reagent

As the reagents, the followings were used.

Phenol (99%; Samchun Pure Chemical Co.) and Formaldehyde (37%; Kanto Chemical Co.) were used as synthetic main raw materials and Triethylamine (99%; Daejung Chemical Co.) was used as a catalyst. Methanol (99%; Duksan Pure Chemical Co.) was used as an addition solvent of the phenol resin. All reagents used in the reaction were used without further purification.

(2) device

To the phenol dissolution and phenol resin intermediate formation, as shown in FIG. 2, the sand dune flask 210, the heater 220, the temperature controller 230, the temperature sensor 240, the stirrer 250, and the condenser 260. A device was used. In FIG. 2 280 means coolant and the apparatus is connected to a vacuum pump. Vacuum ovens and traps were used for phenol resin formation and removal of residual phenol.

The content of each component contained in the phenol resin intermediate layer and phenol resin was analyzed by GC (model: Shimadzu GC-14B, TCD DET / Porapak Q Column). In addition, FT-IR analysis (Bio-Rad, FTS 165) was used to confirm the synthesis of phenol resin.

2. Preparation of Phenolic Resin

After quantifying phenol and formaldehyde, respectively, phenol was sufficiently dissolved at an initial reaction temperature of 30 ° C. After phenol dissolution, a catalyst was added and the inside of the reactor was purged with nitrogen gas.

In order to form a phenolic resin intermediate, the temperature was gradually raised over 1 hour after the addition of the catalyst, and the reactions were further reacted. After the reaction was completed, the reactants were transferred to a 1L beaker and left at room temperature for one day to separate the layers, and the water of the upper layer was removed.

The rest was put in a vacuum oven and condensation reaction was performed at 120 ° C. for 3 hours to remove residual phenol.

3. Experimental Results

3 and Table 1, in the embodiment of the present invention, shows the content of phenol and formaldehyde remaining in the phenol resin intermediate layer according to the amount of phenol and formaldehyde used.

[Table 1] (unit:% by weight)

For evaluation, the amount of formaldehyde (F) to phenol (P) was reacted for 4 hours at 1.0, 1.25, 1.5, and 1.8 in molar ratios (F / P), respectively, and then phenol remaining in the phenol resin intermediate layer. And the content of formaldehyde was measured. At this time, the catalyst was used 1.5% by weight based on 100% by weight of phenol. The reaction temperature was maintained at 90 ° C.

As a result, as the F / P molar ratio was increased, the residual phenol concentration tended to decrease from 9.19 wt% to 7.58 wt%. In addition, residual formaldehyde and water showed concentrations of 0 to 1.08 wt% and 15.5 to 16 wt%, respectively. In addition, the residual amounts of phenol and formaldehyde tended to be opposite to each other, and in order to reduce the amount of unreacted phenol having a great influence on the color of the phenol resin, the molar ratio of F / P was preferably 1.4 to 1.8.

Table 2 shows the resultant content after forming the phenol resin in the vacuum oven according to the amount of phenol and formaldehyde used.

Referring to Table 2, residual phenol, formaldehyde, and water which were seen in the phenol resin intermediate layer were removed. And the amount of phenol resins produced was about 98% by weight. This appears to be due to the fact that most of the residual material evaporated during the formation of the phenolic resin in the vacuum oven.

[Table 2] (unit:% by weight)

Figure 4 shows the reaction time according to the amount of catalyst in the embodiment of the present invention.

For evaluation, the molar ratio (F / P) of formaldehyde to phenol was set to 1.8, and the experiment was carried out by changing only the catalyst concentration while maintaining the reaction temperature at 90 ° C.

As a result, the reaction time tended to decrease as the concentration of the triethylamine catalyst increased. In particular, the reaction time of about 10 hours was required when the amount of the catalyst added was 0.8% by weight to 100% by weight of the phenol resin. It tends to decrease.

5 shows the reaction time according to the reaction temperature in the embodiment of the present invention.

For evaluation, the molar ratio (F / P) of formaldehyde to phenol was fixed at 1.8, and the amount of triethylamine, which is a catalyst, was kept constant at 1.5% by weight relative to 100% by weight of phenol.

As a result, the reaction time tends to be shortened as the reaction temperature increases at a constant reaction molar ratio and catalyst concentration. The reaction time at 70 ℃ is 20 ~ 23 hours, the reaction time was reduced to several hours at 85 ~ 90 ℃, in particular it was confirmed that reduced to 4 to 5 hours at 90 ℃.

Figure 6 shows the results of the FT-IR analysis of the phenol resin prepared according to the embodiment of the present invention.

Referring to Figure 6, F / P: 1.8, addition reaction temperature: 90 ℃, catalyst usage: 1.5% by weight relative to 100 parts by weight of phenol, condensation reaction temperature: 120 ℃ phenol resin prepared under conditions, the main peak- The OH peak appeared well in the wavelength range of 3500 to 3300 cm −1 and the -CH 2-peak appeared in the wavelength range of 3000 to 2900 cm −1, which was almost identical to that of commercial phenol resin Bakelite. The remaining peaks were similar to bakelite.

Figure 7 shows the abrasive paper formed with the top coating layer from the phenol resin prepared according to the embodiment of the present invention.

In general, phenolic resins have a problem of discoloration in reddish brown color upon curing. However, in the case of the phenol resin prepared according to the embodiment of the present invention, it is possible to maintain a color close to transparent after curing as shown in the example shown in FIG.

Therefore, the phenolic resin prepared according to the embodiment of the present invention may be easily colored according to high transparency and may exhibit excellent color retention. This excellent property is due to the amount of phenol remaining in the resin of 0.7% by weight or less in the case of the phenol resin produced according to the present invention.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Such changes and modifications are intended to fall within the scope of the present invention unless they depart from the scope of the present invention. Accordingly, the scope of the present invention should be determined by the following claims.

S110: phenol dissolution step S120: phenol resin intermediate formation step
S130: water removal step S140: phenol resin forming step
210: flask 220: heater
230: temperature controller 240: temperature sensor
250: stirrer 260: condenser
280: coolant

Claims (10)

(a) dissolving phenol in an aqueous formaldehyde solution;
(b) adding phenol and formaldehyde in the presence of triethylamine as a catalyst to form a phenol resin intermediate;
(c) removing the water contained in the result of step (b);
(d) condensing the phenol resin intermediate at a temperature lower than the phenol resin curing temperature to form a phenol resin;
Method for producing a phenol resin, characterized in that the phenol and formaldehyde in a molar ratio of 1: 1.4 to 1: 1.8.
delete The method of claim 1,
The step (b)
As said phenol resin intermediate, trimethylol phenol represented by following formula (1) is formed, The phenol resin manufacturing method characterized by the above-mentioned.
[Formula 1]

The method of claim 1,
The catalyst is
The phenol resin production method, characterized in that added to 1.5 to 3.0% by weight based on 100% by weight of the phenol.
The method of claim 1,
The step (b)
Method for producing a phenol resin, characterized in that carried out at 85 ~ 90 ℃.
The method of claim 1,
The step (c)
Maintaining the resultant of the step (b) at a temperature of 15 ~ 30 ℃ to separate the phenol resin intermediate layer and the water layer, and then removing the water layer phenol resin production method.
The method according to claim 6,
The phenol resin intermediate layer
Method for producing a phenol resin, characterized in that the phenol unreacted in the step (b) comprises 7.5 to 8.5% by weight.
The method of claim 1,
The step (d)
Method for producing a phenol resin, characterized in that carried out at 100 ~ 120 ℃.
9. The method of claim 8,
In the step (d), a phenol resin represented by the following formula (2) is formed, residual phenol, residual formaldehyde, residual water and the phenol resin production method characterized in that the water produced by the condensation reaction is removed.
(2)

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