JPH07179544A - Production of solid benzylic ether type phenolic resin - Google Patents

Abstract

PURPOSE:To obtain a resin useful as a binder for molding material, preventing clouding of molds, having a high melting point by using methanol as a separating solvent and separating a low molecular weight component from a condensation product of a monophenol and an aldehyde. CONSTITUTION:1.0mol of a monophenol (i) (e.g. phenol or cresol) is reacted with 1.0-2.0mols, preferably 1.3-1.8mols of an aldehyde (ii) (e.g. formalin or glyoxal) in the presence of a bivalent metal ion (preferably a bivalent metal salt such as zinc borate or manganese borate) to give a condensation product. 40-60 pts.wt. of methanol based on 100 pts.wt. of the component (i) is added the condensation product while being hot. Further cold methanol or a cold mixed solution of methanol and water is added to the condensation product. The resulting material is cooled and subjected to phase separation to separate an upper layer solution. Preferably a protective colloid is added to a lower layer solution and the condensation product is granulated and separated to give the objective resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for producing a solid benzylic ether type phenol resin. More specifically, the present invention relates to a method for efficiently producing a solid benzylic ether type phenolic resin having a high melting point that does not hinder handling.

[0002]

2. Description of the Related Art Conventionally, a benzylic ether type phenol resin (hereinafter abbreviated as BE type phenol resin) is
Widely used as a binder for organic and inorganic substances. This BE-type phenol resin is a curable phenol resin having a crosslinkable functional group such as a dimethylene ether group or a methylol group in the molecule, and generally monophenols and excess aldehydes are divalent. It is produced by condensing a metal ion as a catalyst, heating and concentrating the obtained reaction mixture, and recovering it in a liquid or solid form.

However, the solid BE-type phenol resin thus obtained contains a large amount of mononuclear components such as free phenol and methylolphenol, and generally has a low melting point, which makes it difficult to handle and, for example, a molding material. When it is used as a binder in (1), it has a drawback that it contaminates the molding die and loses the surface gloss of the molded product, so-called clouding of the die.

[0004]

DISCLOSURE OF THE INVENTION The present invention removes the mononuclear component in such a conventional BE type phenol resin to prevent clouding of the mold and to the extent that it does not hinder the handling. The purpose of the present invention is to provide a method for efficiently producing a BE-type phenol resin having a high melting point.

[0005]

Means for Solving the Problems As a result of intensive studies on the method for reducing the mononuclear component in the BE resin, the present inventors have found that methanol, which has a specific dissolving action for the BE type phenol resin, By using it as a separation solvent,
It was found that the mononuclear component in the BE type phenol resin can be selectively and easily reduced, and the present invention has been completed based on this finding.

That is, in the present invention, (A) a step of reacting 1.0 mol of monophenols with 1.0 to 2.0 mol of aldehydes in the presence of a divalent metal ion to obtain a condensation product, (B) A step of adding and dissolving a required amount of methanol when the condensation product is heated, (C) Adding cold methanol or a cold mixed solution of methanol and water to the methanol solution obtained in the previous step, and cooling to cause phase separation. And a step of removing the formed upper layer liquid and (D) separating the high molecular weight condensation product in the lower layer liquid, which provides a method for producing a solid benzylic ether type phenol resin. Is.

The step (A) of the present invention is a step of reacting a monophenol with an aldehyde in the presence of a divalent metal ion to form a condensate.

Examples of the starting monophenols used in the step (A) include phenol, cresol, xylenol, pt-butylphenol, resorcinol, catechol and purified residues of monophenols. It is not limited to. These monophenols may be used alone or in combination of two or more.
Further, if necessary, a purified residue of bisphenol F or bisphenol A may be used in combination.
On the other hand, examples of the aldehydes include formaldehydes such as formalin, paraformaldehyde, and polyoxymethylene, glyoxal, furfural,
Examples thereof include, but are not limited to, benzaldehyde and the like. These aldehydes may be used alone or in combination of two or more. Regarding the use ratio of the monophenols and the aldehydes, the excess amount of the aldehydes is 1.0 to 2.0 mol, preferably 1.3 to 1.8 mol with respect to 1.0 mol of the monophenols. Used in. If the proportion of the aldehydes used is less than 1.0 mol, practical curability cannot be obtained, and if it exceeds 2.0 mol, the amount of gas generated increases and the operation becomes difficult.

The source of the divalent metal ion acting as a catalyst for this condensation reaction is, for example, a divalent metal salt,
In addition to the combination of a divalent metal oxide or hydroxide or both with an acidic compound, a divalent metal oxide or hydroxide or a combination thereof can be used. Metal salts are preferred. The amount of its use varies depending on its type and cannot be determined unconditionally, but it is generally 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of monophenols. Selected in a range. Examples of the divalent metal salt described above include zinc borate, manganese borate, magnesium borate, zinc acetate, manganese acetate, lead acetate, zinc naphthenate, lead naphthenate, copper naphthenate, calcium neodecanoate, zinc lactate, Examples thereof include manganese lactate, zinc chloride, manganese chloride and the like, but are not limited thereto. These divalent metal salts may be used alone or in combination of two or more. Examples of oxides and hydroxides of divalent metal salts include zinc oxide, magnesium oxide, manganese oxide, zinc hydroxide, magnesium hydroxide, manganese hydroxide, nickel hydroxide, etc. It is not limited. These divalent metal oxides and hydroxides may be used alone or in combination of two or more. Examples of the acidic compound include boric acid, acetic acid,
Examples thereof include hydrochloric acid.

In the step (A), first, the mixture of the above-mentioned monophenols, aldehydes and catalyst is reacted while stirring, or further concentrated under reduced pressure at a temperature not exceeding 130 ° C. to obtain a condensation product. At this time, since the reaction is usually performed by heating to the reflux temperature, the condensation product is
The temperature is high. Next, in step (B), methanol is added to this condensation product. The high molecular weight BE-type phenolic resin in the condensation product is hardly soluble in methanol, but due to the synergistic effect that the mononuclear component is easily soluble in methanol and dissolves when heated, it almost dissolves when an appropriate amount of methanol is added. , Can be in a solution state. On the other hand, the mononuclear body component is easily dissolved in methanol and completely dissolved.

The amount of methanol added in this step (B) is 40 to 100 parts by weight of the charged monophenols.
About 60 parts by weight is sufficient.

Next, in the step (C), cold methanol or a cold mixed solution of methanol and water is added to the solution obtained in the previous step with stirring until it becomes cloudy, and the temperature of the solution is adjusted to around 30 to 50 ° C. Cooling. When the cooling solution thus obtained is left standing with stirring stopped, it is phase-separated into an upper layer liquid rich in mononuclear component and a lower layer liquid rich in BE-type phenol resin component. When a mixture of methanol and water is used for this phase separation, the mixing ratio of methanol and water is selected within the range of 10:90 to 90:10 by weight.

The amount of methanol added in step (C) is preferably 180 parts by weight or less, more preferably 180 parts by weight or less, based on 100 parts by weight of the charged amount of monophenols, as the total amount of methanol added in step (B). Is selected in the range of 100 parts by weight or less. The upper layer liquid thus phase-separated is removed by, for example, decantation.

The lower layer liquid, on the other hand, is washed with cold water or hot water to remove residual methanol, if desired, and then (D).
In the step, the high molecular weight condensation product contained therein is separated and collected. As the separating means, a vacuum concentration method, a spray drying method, an underwater precipitation method, an underwater pulverization method, an aqueous granulation method, or the like can be used. From the viewpoint of properties and the like, the water-based granulation method is preferable. In the water-based granulation method, the lower layer liquid is agitated while stirring the lower layer liquid in an amount of 10 to 300.
About 10% by weight of water and about 1-10% by weight of protective colloid (eg gum arabic, hydroxyethyl cellulose,
After forming resin particles by adding carboxymethyl cellulose, partially saponified polyvinyl alcohol, polyethylene glycol, etc., the resin particles can be filtered and dried to obtain a particulate resin.

[0015]

EFFECTS OF THE INVENTION According to the production method of the present invention, a phase separation operation using methanol, which acts as a poor solvent for the high molecular weight component of the BE type phenol resin and as a good solvent for the low molecular weight component, is carried out. By applying the above, the low molecular weight component in the BE type phenol resin can be selectively and easily reduced. As a result, the obtained BE type phenol resin has a high melting point, and it is possible to solve the problem at the time of handling work based on the conventional low melting point resin. Moreover, when the BE-type phenol resin obtained is used as a binder for a molding material, the occurrence of mold clouding can be greatly improved as compared with the conventional low melting point resin. The BE-type phenol resin obtained by the production method of the present invention is used in various industries as a binder for epoxy resin, a binder for building materials, refractories, felts, shell molds, etc. It can be used in the field.

[0016]

The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Regarding the obtained BE resin, the content of mononuclear component and the melting point were measured according to the following methods. (1) Mononuclear component content (free phenol and methylolphenol) HLC8010 type gel filtration chromatography manufactured by Tosoh Corporation (column: GXL1000 + 2000, carrier: tetrahydrofuran 1 cc / min, detector: UV)
The total area was calculated by the area percentage method. (2) The melting point was measured according to JIS K 6911.

Example 1 A reaction vessel equipped with a reflux condenser, a thermometer and a stirrer was charged with 2000 g of phenol, 1196 g of 80% by weight paraformaldehyde and 6 g of zinc acetate, and the mixture was reacted for 4 hours at the reflux temperature while stirring, Vacuum degree 20T
It was heated and concentrated at orr and cooled to 80 ° C. to obtain a condensation product. Thereafter, 1100 g of methanol (55% by weight / weight of charged phenol) was gradually added to dissolve the condensation product in methanol. Next, while stirring this methanol solution, 900 g of methanol (45% by weight /
After adding the amount of charged phenol), the mixture was cooled to 30 ° C. to stop stirring, and the mixture was allowed to stand still to cause phase separation, and then the upper layer liquid was removed. Then, 2000 g of hot water at 70 ° C. was added to the obtained lower layer liquid, and the mixture was stirred at 70 ° C. for 30 minutes, cooled to 40 ° C., and allowed to stand to remove the upper layer liquid. Then, while stirring the obtained lower layer liquid, 3000 g of water and 2
Granulation of the condensation product was carried out by adding 200 g of 0% by weight aqueous solution of gum arabic, and the mixture was stirred at 80 ° C. for 30 minutes.
It was aged for minutes, cooled to 30 ° C., and filtered to obtain water-containing resin particles. Then, the water-containing resin particles were fluidized and dried at a temperature of 68 ° C. to obtain particulate BE type phenol resin 1. The mononuclear component content and melting point of the obtained BE type phenol resin 1 were measured. The results are shown in Table 1.

Example 2 A condensation product was prepared at 80 ° C. in the same manner as in Example 1, and then 1100 g of methanol (55% by weight / amount of phenol charged) was gradually added to dissolve the condensation product in methanol. It was Then, while stirring this methanol solution, a mixture of 600 g of water and 300 g of methanol (water / methanol mixture weight ratio = 2/1, methanol used amount 15% by weight / charged phenol amount) was added, and then cooled to 30 ° C. Then, the stirring was stopped, and the mixture was allowed to stand still for phase separation, and then the upper layer liquid was removed. Then, 2000 g of warm water at 70 ° C. was added to the obtained lower layer liquid, and the mixture was stirred at 70 ° C. for 3 hours.
After stirring for 0 minutes, the mixture was cooled to 40 ° C. and left standing to remove the upper layer liquid. Then, 3000 g of water and 220% by weight aqueous solution of gum arabic 220 are stirred into the obtained lower layer liquid.
After adding g to granulate the condensation product, it was aged at 80 ° C. for 30 minutes under stirring, cooled to 30 ° C., and filtered to obtain water-containing resin particles. Then, the water-containing resin particles were fluidized and dried at a temperature of 65 ° C. to obtain particulate BE type phenol resin II. The mononuclear component content and melting point of the obtained BE type phenol resin II were measured. The results are shown in Table 1.

Example 3 In a reaction vessel similar to that of Example 1, 2000 g of phenol, 8
1356 g of 0% by weight paraformaldehyde and 6 g of zinc acetate were charged, the mixture was reacted for 6 hours at the reflux temperature while stirring, and then cooled to 80 ° C. to obtain a condensation product. Thereafter, 1200 g of methanol (60% by weight / amount of phenol charged) was gradually added to dissolve the condensation product in methanol. Next, while stirring this methanol solution, 2400 g (120% by weight / phenol) of methanol was added, cooled to 30 ° C. to stop stirring, and allowed to stand still for phase separation, and then the upper layer liquid was removed. . After that, stir the obtained lower layer liquid and add water 300
Granulation of the condensation product was carried out by adding 0 g and 200 g of a 20% by weight aqueous solution of gum arabic, and the mixture was stirred and stirred at 80
Aging was carried out at 30 ° C. for 30 minutes, cooled to 30 ° C., and filtered to obtain water-containing resin particles. Then, the water-containing resin particles are
It was fluidized and dried at a temperature of ° C to obtain a particulate BE type phenol resin III. The mononuclear component content and melting point of the obtained BE type phenol resin III were measured. The results are shown in Table 1.

Comparative Example A particulate BE type phenol resin IV was obtained in the same manner as in Example 1 except that the phase separation operation using methanol was omitted. The mononuclear component content and melting point of the obtained BE type phenol resin IV were measured. The results are shown in Table 1.

Application Example BE-type phenolic resin I obtained in the above Examples and Comparative Examples
45 parts by weight of each of IV to IV and glass fiber 5
5 parts by weight, 1.5 parts by weight of MgO and 2.5 parts by weight of zinc stearate were mixed, and the mixture was kneaded with a heating roll, cooled, and pulverized to prepare a molding material.
This molding material was continuously molded by an injection molding machine, and the number of moldings in which clouding of the mold was generated on the surface of the molded product was measured. The results are shown in Table 1.

[0023]

[Table 1]

Claims (2)

[Claims] 1. A step of (A) reacting monophenols (1.0 mol) with aldehydes (1.0 to 2.0 mol) in the presence of a divalent metal ion to obtain a condensation product, (B) Formed by adding a required amount of methanol to the condensation product when it is heated to dissolve it, and (C) adding cold methanol or a cold mixture of methanol and water to the methanol solution obtained in the previous step to cool and cause phase separation. Removing upper layer liquid and (D)
A method for producing a solid benzylic ether type phenolic resin, which comprises a step of separating a high molecular weight condensation product in a lower layer liquid. 2. The production method according to claim 1, wherein in step (D), a protective colloid is added to the lower layer liquid to granulate and separate the condensation product.