JPH04145116A - Production of new modified phenolic resin - Google Patents

Abstract

PURPOSE:To obtain the subject resin excellent in strength, heat and oxidation resistance and electrical insulating properties by heating a petroleum-based heavy oil, etc., with a specific aromatic hydrocarbon fraction and hydrogen content in the aromatic ring, formaldehyde polymer and an acid catalyst and reacting phenols therewith. CONSTITUTION:Formaldehyde polymer is mixed with 1 mol petroleum-based heavy oils or pitches with 0.40-0.95 value of aromatic hydrocarbon fraction (fa) and 20-80% value of hydrogen content (Ha) in the aromatic ring so as to provide 1-10 number or mol expressed in terms of formaldehyde. Phenols are then added to the resultant mixture at an addition rate of 0.05-5wt.%/min based on the total weight of the aforementioned petroleum-based heavy oils or the pitches and formaldehyde polymer while being heated and stirred in the presence of an acid catalyst. In the process, polycondensation is carried out so as to afford 0.3-5 number of mol of the added phenols based on 1mol petroleum-based heavy oils or pitches. One or more treatments for removing acids such as neutralizing treatment, washing treatment with water and extraction treatment are then performed to provide the objective modified resin.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a novel modified phenolic resin, and more specifically, a novel method for producing a novel modified phenolic resin, which is produced by modifying it with petroleum heavy oils or pitches and further adjusting the pH. The present invention relates to a method for producing a modified phenolic resin.

[Prior art and problems to be solved by the invention] In general, phenolic resins have excellent mechanical properties and have been widely used, but they are somewhat inferior in light resistance, alkali resistance, etc., and they do not absorb moisture or alcohol. The dimensions and electrical resistance of these materials tend to change easily, and they also have problems such as low heat resistance, especially low oxidation resistance at high temperatures.

In order to solve these problems, various modifications to phenolic resins are being considered.

In particular, in order to impart resistance to changes caused by light, chemicals, oxidation, etc., modification using oils, fats, rosins, or neutral aromatic compounds is said to be effective, and various studies have been conducted.

For example, Huang Qingyun et al. studied the reaction of m-xylene-formaldehyde resin with novolak and showed that m-xylene-formaldehyde resin can be used as a curing agent for novolak.

Furthermore, even if low molecular weight phenols are added and reacted after m-xylene and formaldehyde are reacted,
It has also been revealed that phenols are not completely insolubilized and have limited ability as hardening agents [Industrial Chemistry Magazine,
Vol. 60, p. 1579 (1957)).

Furthermore, Japanese Patent Publication No. 53-5705 describes a drying oil-modified phenolic resin obtained by modifying a mesitylene resin obtained by reacting an alkylbenzene containing mesitylene as a main component with formaldehyde with a drying oil and phenols, and further forming a resol. or disclosed. In producing this resin, the catalyst used in the first half of the reaction is an acid.
On the other hand, the catalyst used in the latter half of the reaction is a base. Therefore, the catalyst in the first half of the reaction and the catalyst in the second half cannot essentially coexist, and as a result, it is always necessary to divide the reaction into two or more stages. There is also the problem that the basic catalyst is consumed for acid neutralization, which is disadvantageous in terms of cost.

Furthermore, in JP-A No. 61-235413, when producing a phenol-modified aromatic hydrocarbon resin by reacting an aromatic hydrocarbon-formaldehyde resin with phenol, diallyl is used as an aromatic hydrocarbon-formaldehyde resin. Methane content is 5% by weight or less, xylenol value is 1
It is disclosed that a thermosetting resin with excellent heat resistance can be obtained by using a highly reactive material of 5 mol/kg or more. Although this resin has a light inherent color and exhibits excellent properties, it has the drawback of slow curing and requiring long-term processing at high temperatures.

All of these methods involve multiple steps, including the first step of producing an aromatic hydrocarbon-formaldehyde resin, and the next step of reacting the aromatic hydrocarbon-formaldehyde resin with phenols. be. As a result, the manufacturing process, especially the control system, is complicated, leading to increased equipment costs and manufacturing costs, which poses various practical problems.

Furthermore, Japanese Patent Publication No. 60-36209 discloses that one or more polycyclic aromatic hydrocarbons selected from the group consisting of acenaphthene, acenaphthylene and derivatives thereof are mixed with phenols and formaldehyde,
A method is disclosed in which the reaction is carried out by heating in a two-step process in the presence of an acid catalyst.

This method selectively uses compounds highly reactive with formaldehyde among polycyclic aromatic hydrocarbons.
Although it has the advantage of being able to obtain modified phenolic resins with excellent properties, there are no thermal decomposition products of petroleum or coal that contain large amounts of these compounds, and it is necessary to synthesize them in order to produce them in large quantities. Yes, but the disadvantage is that it costs more.

The present inventors have identified the following two drawbacks of phenolic resins modified with oils, fats, rosins, or neutral aromatic hydrocarbons: (1) The manufacturing process is complex and requires multiple stages; In many cases, it is difficult to heat-cure unless special raw materials are used due to their small reactivity, so we have conducted intensive research to solve the problem of high raw material costs and high curing costs. In the process, the inventors' group used heavy petroleum oils or pitches with specific properties, and added formaldehyde polymers and phenolic resins under certain conditions in the presence of an acid catalyst to perform polycondensation. (Japanese Patent Application No. 1-95366). This method is
This method is industrially very advantageous because the process is relatively simple and the heavy petroleum oils or pitches used are easily available. In addition, the modified phenolic resin obtained by this method has mechanical strength, heat resistance, and electrical insulation properties.

It has excellent oxidation resistance and is expected to be used in a variety of fields.

However, when the present inventors conducted further research,
Although the modified phenolic resin produced by the above method has the above-mentioned properties, the acid catalyst used in the production process remains in the resin and causes corrosion of molds, etc. I found that there were some problems.

[Problem to be solved by the invention]

The present invention solves these problems, does not cause any trouble during molding, etc., and
The purpose of this study is to develop a method for efficiently producing modified phenolic resins with excellent physical properties.

That is, in the present invention, the aromatic hydrocarbon fraction fa value is 0.4.
0 to 0.95, aromatic ring hydrogen amount Ha value is 20 to 80% per mole of petroleum heavy oil or pitch, formaldehyde polymer is added to a formaldehyde equivalent mole number of 1 to 10. While heating and stirring in the presence of an acid catalyst, phenols were added at a rate of 0.05 to 5% by weight/min based on the total weight of the petroleum heavy oil or pitch and the formaldehyde polymer. Polycondensation is carried out by adding at an addition rate such that the number of moles of phenol added per mole of petroleum heavy oil or pitch is 0.3 to 5, and then neutralized. The present invention provides a method for producing a novel modified phenolic resin, which is characterized by carrying out at least one type of acid removal treatment selected from treatment, water washing treatment, and extraction treatment.

The petroleum heavy oil or pitch used in the method of the present invention must have an aromatic hydrocarbon fraction fa value of 0.40 to 0.95 and an aromatic ring hydrogen content Ha value of 20 to 80%.

Note that the aromatic hydrocarbon fraction fa value and the aromatic ring hydrogen amount Ha value are shown in the following formula.

This fa value can be determined by 13C-NMR. Further, the Ha value can be determined by 'H-NMR.

In the method of the present invention, as the fa value of petroleum heavy oils or pitches decreases, the aromatic content decreases, so the effect of improving the performance of the resulting modified phenolic resin tends to decrease. In particular, if the fa value is less than 0.4, this modification effect becomes extremely small, which is not preferable.

Further, in the case of petroleum heavy oils or pitches having an fa value of more than 0.95, the reactivity of aromatic ring hydrogen with formaldehyde is undesirable. Therefore, f
The a value is preferably 0.4 to 0.95, particularly preferably 0.
．． It is 5 to 0.8.

Additionally, when the Ha value of the raw petroleum heavy oils or pitches decreases, the amount of aromatic ring hydrogen that reacts with formaldehyde decreases, resulting in poor reactivity, resulting in poor performance modification effects of phenolic resins. Undesirable.

Regarding the Ha value, 20% or more is considered to be practical. On the other hand, as the Ha value increases, the reactivity of aromatic ring hydrogen tends to gradually decrease. Ha value is 80%
If larger petroleum-based heavy oils or pitches are used as raw materials, the strength of the modified phenol resin tends to decrease, which is not preferable. In the present invention, the Ha value is 20
-80% is desirable, particularly preferably 25-60%.

Although the number of condensed rings in the petroleum heavy oils or pitches used here is not particularly limited, it is preferably a condensed polycyclic aromatic hydrocarbon having mainly 2 to 4 rings. In the case of fused polycyclic aromatic hydrocarbons having five or more rings, the boiling point exceeds 450'C in most cases, so it is difficult to collect those with a narrow boiling point range, and there is a problem that the quality is unstable. In addition, when the hydrocarbon is mainly a monocyclic aromatic hydrocarbon, its reactivity with formaldehyde is low, so there is a problem that the effect of modifying the performance of the phenol resin is small.

The petroleum heavy oils or pitches that are the raw materials for the modified phenolic resin in the present invention include distillation residues of crude oil, hydrogen cracking residues, catalytic cracking residues, naphtha or LPG pyrolysis residues, and these residues. It is obtained as a vacuum distillate of oil, an extract by solvent extraction, or a heat-treated product, and from these, select one with an appropriate Fa value and Ha value. The polymer is paraformaldehyde.

linear polymers such as polyoxymethylene (especially oligomers) and cyclic polymers such as trioxane.

The mixing ratio of petroleum heavy oils or pitches and formaldehyde polymer is the number of moles of formaldehyde polymer in terms of formaldehyde per 1 mole of the average number of moles calculated from the average molecular weight of petroleum heavy oil or pitch. , 1 to 1o.

If this mixing ratio is less than 1, the resulting cured product of the modified phenol resin will have low strength, which is not preferred. on the other hand,
If it exceeds 1O, the performance and yield of the resulting cured product will hardly change, so it is considered wasteful to use more formaldehyde polymer. Here, the mixing ratio of petroleum heavy oil or pitch to formaldehyde polymer is preferably 2 to 7.

The acid catalyst used in producing the above-mentioned modified phenol resin may be a Brønsted acid or a Lewis acid, but a Brønsted acid is preferably used.

Bronsted acids include toluenesulfonic acid, xylenesulfonic acid, and hydrochloric acid.

Although sulfuric acid, formic acid, etc. can be used, p-1-luenesulfonic acid and hydrochloric acid are particularly excellent.

The amount of the acid catalyst used is 0.1 to 30% by weight, preferably 1 to 10% by weight, based on the total amount of petroleum heavy oil or pitch and formaldehyde polymer. If the amount of acid catalyst used is small, the reaction time tends to be longer.
In addition, unless the reaction temperature is raised, the reaction tends to be insufficient. On the other hand, even if the amount of acid catalyst used is increased, the reaction rate will not increase accordingly, which may be disadvantageous in terms of cost.

The phenols used in the present invention are preferably one or more phenolic compounds selected from the group of phenol, cresol, xylenol, and resorcinol.

In producing the above-mentioned modified phenolic resin, phenols are added little by little and mixed by a method such as dropping. The rate of addition is 0.0% relative to the total weight of the reaction mixture.
05 to 5% by weight/min, preferably 0.1 to 2% by weight/min. If the addition rate is less than 0.05% by weight/min, the time required for addition is too long and the cost increases, which is not preferable. On the other hand, the adding rate is 5% by weight.
If it exceeds 1/min, the added phenol reacts rapidly with free formaldehyde, making it difficult to form a homogeneous mixture or a collinear compound, which is not preferable.

The reason for this non-uniformity is that veraenols are significantly more reactive to formaldehyde than heavy petroleum oils or pitches, and the initial concentration of phenols must be kept low. It is speculated that this is because formaldehyde selectively reacts with phenols or a condensate of phenols and formaldehyde produced by the reaction, making them poorly soluble in the system. Alternatively, formaldehyde may be consumed first in the reaction between phenols or a condensate of phenols and formaldehyde produced by the reaction, resulting in heavy petroleum oils or pitch or heavy petroleum oils produced by the reaction. Alternatively, it is speculated that the condensate of pitches and formaldehyde cannot further react with formaldehyde and is separated from the reaction system.

In the above operation, the timing to start adding phenols is not particularly limited, but the phenols are added at a certain point when the reaction rate of formaldehyde estimated from the amount of remaining free formaldehyde is 70% or less, preferably 50% or less. . The addition may be started at a time when the reaction between heavy petroleum oils or pitches and formaldehyde has not substantially progressed. When the reaction rate with formaldehyde exceeds 70%, the amount of formaldehyde that reacts with phenols decreases, resulting in a marked decline in the performance of the resulting resin, and in extreme cases, a cured product may not be obtained unless a curing agent is added. I don't like it because it disappears.

The amount of phenols added is 0.3 to 5 as the number of moles of phenols per 1 mole of the average number of moles calculated from the average molecular weight of petroleum heavy oils or pitches. If the amount added is less than 0.3, the reactivity between heavy petroleum oils or pitches and formaldehyde is inferior to the reactivity between phenols and formaldehyde.
There is a problem that sufficient crosslinking density is not achieved and the strength of the cured product is lower than that of general phenolic resins. In particular, it has low impact resistance and is brittle. On the other hand, if the amount of phenol added exceeds 5, the modification effect due to modification of the phenol resin will be small, which is not preferable.

The amount of this phenol added is preferably 0.5 to 3.

The reaction time is 50-160°C, preferably 60-12°C.
It is 0°C. The reaction temperature is determined in consideration of the raw material composition, reaction time, properties of the resin to be produced, and the like.

The reaction time is 0.5 to 10 hours, preferably 1 to 5 hours. The reaction time is based on raw material composition and reaction temperature.

It is determined by considering the rate of addition of phenols, the properties of the resin to be produced, etc.

When the above reaction is carried out batchwise, it can be carried out in -steps, and is preferably carried out in -steps.

In addition, when performing in a continuous manner, there is no need to use difficult-to-control equipment that continuously mixes two or more reaction products in fixed amounts, which is used in conventional modified phenolic resins. A mixing type reaction vessel may be placed and the phenols to be added may be fed into the vessel in fixed amounts. Such devices are relatively inexpensive and easy to operate.

A solvent can be used during the above-mentioned reactions.

Although the reaction can be carried out with a combined solvent, the use of a solvent lowers the viscosity of the reaction system and improves the uniformity of the reaction.

However, it is necessary to remove the solvent before curing.
Except for special items, the cost will generally increase.

Examples of solvents include halogenated aromatic hydrocarbons such as chlorobenzene, nitrated aromatic hydrocarbons such as nitrobenzene, nitrated aliphatic hydrocarbons such as nitroethane and nitropropane, perchlorene, trichrene, and carbon tetrachloride. Halogenated aliphatic hydrocarbons and the like can be used.

The modified phenol resin obtained by the above operation generally has a low pH value of about 1 to 2 and is highly acidic because the acid catalyst used during production remains. Therefore, in the method of the present invention, at least one type of acid removal treatment selected from neutralization treatment, water washing treatment, and extraction treatment is further performed to adjust the pH value to about 3 to 7, preferably about 5 to 7. This prevents corrosion of molding equipment such as molds, etc.
Preferred from a practical point of view. Here, as the neutralization treatment,
Alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, ammonia, and organic compounds such as diethylenetriamine, triethylenetetramine, aniline, and phenylenediamine. Treatment may be performed using various basic substances such as amines. Further, the water washing treatment may be carried out according to a conventional method, and the conditions are not particularly limited, as long as the acid catalyst in the modified phenol resin can be removed. Therefore, in the water washing process, a neutralization process using the above-mentioned basic substance may be performed in parallel. Additionally, alcohol such as methanol or other water-soluble organic solvents may be used together with water.

Regarding the extraction process, the conditions should be selected so that the acid catalyst can be separated from the modified phenolic resin by extraction.
The operating procedure and operating conditions may be in accordance with conventional methods. Further, the above-mentioned neutralization treatment and water washing treatment may be performed in parallel.

Specifically, regarding the acid removal treatment, for example, a method may be considered in which the above-mentioned basic substance is added to the reaction mixture to neutralize it after the resin synthesis reaction is completed. Alternatively, there is a method in which the acid is removed by directly washing the powdered resin with water or hot water, and a method in which the resin is dissolved in a suitable solvent and then washed with water is also considered.

By performing such acid removal treatment, the acidity of the resulting modified phenol resin is weakened, and as a result, corrosion of various devices can be prevented.

Further, in the method of the present invention, a post-curing treatment may be performed after the acid removal treatment. This post-curing treatment is usually carried out by molding the modified phenol resin obtained by polycondensation using an appropriate molding method (compression molding, injection molding, etc.).

15 for the molded product obtained after molding by extrusion molding, etc.
Heat treatment may be carried out at 0 to 300°C for about 0.5 to 10 hours, and by performing a curing treatment after this, a molded article with excellent -layer heat resistance can be obtained.

〔Example〕

Next, the present invention will be explained in more detail and concretely using Examples. These do not limit the invention.

Example 1 85 g of raw material oil with the properties shown below, 70 g of paraformaldehyde, p-toluenesulfonic acid (l hydrate) IO,4
g and 200 g of 0-dichlorobenzene were charged into a glass reactor, and the temperature was raised to 98°C while stirring. 98°C
When the temperature reached 53 g, 53 g of phenol was added dropwise at a rate of lcc/min. After the dropwise addition was completed, stirring was continued for another 2 hours to react, and then triethylenetetramine (TETA) was added.
4.4 g was added and further stirred for 30 minutes.

After the reaction was completed, the reaction mixture was poured into 1000 g of n-hexane to precipitate the reaction product. After filtering and washing the precipitate, it was dried under reduced pressure at 25°C to obtain modified phenolic resin 17.
Obtained 0g.

Add 100 g of distilled water and a small amount of methanol to 10 g of this modified phenol resin, stir for 30 minutes, and adjust the pH of the aqueous phase.
When examined, the pH was 5.1. In addition, TET
Regarding the modified phenol resin that had not been treated with A, the pH of the aqueous phase was examined in the same manner as above, and the pH was 1.6.
Met.

Therefore, modified phenolic resin treated with TETA,
It can be seen that the acidity has been significantly improved.

This TETA-treated modified phenolic resin was placed in a mold, and the mold temperature was 240°C and the pressure was 300 kgf/cd.
When compression molding was carried out under conditions of a molding time of 20 minutes, a thermoset molded product was obtained.

Properties of raw material average molecular weight 271 Boiling point (normal pressure conversion 'C) 241.5-466, 5 Aromatic hydrocarbon fraction (FA) o, 65 Aromatic ring hydrogen content (
Ha) (%) 28 Example 2 135 g of the feedstock oil shown above, 1 paraformaldehyde
10g, p-toluenesulfonic acid (l hydrate) 16.5
g and 220 g of 0-dichlorobenzene were charged into a glass reactor, and the temperature was raised to 95° C. without stirring. 95°
When the temperature reached C, 84 g of phenol was added dropwise at a rate of lcc/min, and after the addition of phenol was completed, the mixture was stirred for an additional 15 minutes to react. After the reaction is complete, the reaction mixture is heated to 10
00 g of n-hexane to precipitate the reaction product.

The precipitate was filtered, washed, and dried under reduced pressure at 25°C to obtain 250 g of modified phenol resin.

Chloroform insoluble matter (approximately 15% based on the total amount of resin) was removed by filtration from 100 g of the obtained modified phenol resin. The obtained chloroform solution was washed with water to remove residual acid catalyst, and then a solvent removal operation was performed to remove chloroform. When the pH of the obtained modified phenol resin was examined in the same manner as in Example 1, it was found to be pH=6.0. -The pH of the modified phenolic resin that has not been subjected to power washing treatment is 1.5.The modified phenolic resin that has been subjected to the water washing treatment as described above is placed in a mold, and the mold temperature is 250°C and the pressure is 300kgf/c.
When compression molding was performed under the conditions of nf and molding time of 30 minutes, a thermoset molded product was obtained.

〔Effect of the invention〕

As described above, according to the method of the present invention, a new material with excellent mechanical strength, heat resistance, electrical insulation, oxidation resistance, etc. can be produced using easily and inexpensively available raw materials and with simple operation. Modified phenolic resin can be efficiently produced. Moreover, since the obtained modified phenolic resin has greatly improved acidity, there is no fear of corrosion of molding equipment such as a mold during molding, and it is extremely convenient from a practical standpoint. Furthermore, the modified phenol resin that has been subjected to post-curing treatment has further improved heat resistance.

Therefore, the novel modified phenolic resin obtained by the method of the present invention is expected to be effectively used as a material for molded articles in various fields.

Patent applicant: Kashima Oil Co., Ltd. Agent Patent Attorney Tamotsu Otani Voluntary writing of procedural amendments) November 6, 1990

Claims (6)

[Claims] (1) Aromatic hydrocarbon fraction fa value is 0.40 to 0.95
, a formaldehyde polymer is mixed with 1 mole of petroleum heavy oil or pitch having an aromatic ring hydrogen content Ha value of 20 to 80% so that the number of moles in terms of formaldehyde is 1 to 10, While heating and stirring in the presence of an acid catalyst, phenols are added in an amount of 0.05 to 0.05% based on the total weight of the petroleum heavy oil or pitch and the formaldehyde polymer.
Polycondensation is carried out by adding at an addition rate of 5% by weight/min, and at that time, the number of moles of phenol added per mole of the petroleum heavy oil or pitch is 0.3 to 5. 1. A method for producing a novel modified phenolic resin, which comprises the steps of: removing the acid, and then performing at least one type of acid removal treatment selected from neutralization treatment, water washing treatment, and extraction treatment. (2) The manufacturing method according to claim 1, wherein the pH of the novel modified phenol resin after acid removal treatment is 3 to 7. (3) Petroleum-based heavy oils or pitches are mainly
The method according to claim 1, wherein the hydrocarbon is a 4-ring condensed polycyclic aromatic hydrocarbon. (4) The production method according to claim 1, wherein the phenol is one or more phenolic compounds selected from the group consisting of phenol, cresol, xylenol, and resorcinol. (5) The production method according to claim 1, wherein the phenol is added at a time when the reaction rate of formaldehyde is 70% or less. (6) The manufacturing method according to claim 1, wherein after the acid removal treatment, the product is molded and further subjected to a post-curing treatment.