JPH05320295A - Method for producing aromatic liquid resin - Google Patents

Abstract

PURPOSE:To provide a process for producing in a higher yield a liq. arom. resin excellent in heat resistance, free of any smell and favorable for the handling thereof. CONSTITUTION:A process for producing a liq. arom. resin, which comprises feeding an arom. compd. or a feedstock oil containing the arom. compd. as the main component and an acid catalyst and then adding thereto a given amt. of formaldehyde. In the process, an alcohol having 3 or 4 carbon atoms, if added to the reaction system, can further improve the yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aromatic liquid resin which can be used as a modifier, a softener and the like in a wide range of industrial fields such as tackiness / adhesives, paints and plastics processing.

More specifically, an aromatic liquid resin having excellent heat resistance, low volatility and low odor is formed from an aromatic compound or a fraction containing an aromatic compound as a main component (hereinafter referred to as "raw material oil") and formaldehyde. At the time of production, a method for producing an aromatic liquid resin capable of improving the yield of the liquid resin by charging a feed oil and an acid catalyst into a reaction vessel in advance and finally adding a predetermined amount of formaldehyde into the reaction system. It is about.

[0003]

2. Description of the Related Art Conventionally, aromatic liquid resins have generally been used in the boiling range of 140 to 280 obtained by thermal decomposition of olefins having a double bond in the side chain such as styrene and α-methylstyrene derivatives, and petroleum. It is manufactured by polymerizing cracked oil fractions at about ℃.

Since this cracked oil fraction also contains olefins as a main component, double bonds are completely removed from the obtained aromatic liquid resin as in the case of using styrene or an α-methylstyrene derivative as a raw material. Is difficult to do. Therefore, aromatic liquid resins made from olefins generally have the drawback of being inferior in heat resistance and odor.

A method of secondarily hydrogenating an aromatic liquid resin for the purpose of reducing double bonds is known, but an increase in manufacturing cost is inevitable and the aromatic liquid resin is inexpensive. It is hard to say that it is a method that can lead to such a great feature.

Further, other aromatic liquid resins include xylene resin and liquid coumarone resin. However, the xylene resin does not contain a double bond, but since it contains an ether bond, a methylol bond or the like which is an oxygen-containing functional group, it is generally insufficient in heat resistance and has a large volatile content.

Since the liquid coumarone resin uses a coal dry distillation fraction containing coumarone which is an oxygen-containing compound, it generally has a bad odor and is not preferable in handling.

The inventors of the present invention have studied synthesizing an aromatic liquid resin containing neither a double bond nor an oxygen atom from the above consideration of conventional aromatic liquid resins. By reacting raw oil containing no formaldehyde with formaldehyde in the presence of an acid catalyst, the obtained solid resin component of aromatic resin containing neither double bond nor oxygen atom is separated by distillation.
It was found that an aromatic liquid resin containing neither a heavy bond nor an oxygen atom can be obtained, and a patent has been applied (JP-A-3-29238).
No. 0).

Since this aromatic liquid resin does not contain a double bond or oxygen atom, it exhibits excellent properties in terms of heat resistance, volatile matter and odor, but it is obtained as a by-product of solid resin production There is a problem that the rate is low.

The liquid resin selectivity in the aromatic resin can be improved by lowering the molar ratio of formaldehyde to the feed oil in order to increase the liquid fraction in the aromatic resin. However, it is difficult to say that this is an industrially advantageous measure because the yield of the entire aromatic resin including solids decreases.

Therefore, the present inventors have studied a method of improving the selectivity of the liquid resin without lowering the overall resin yield, and as a result, by adding alcohol to the reaction system, the yield of the entire aromatic resin is increased. It has been found that the liquid resin selectivity in the aromatic resin can be improved without lowering, and a patent application (Application No. 4-024290) was filed.

However, even if this method is used, the selectivity of the liquid resin cannot fully satisfy the industrial requirement of manufacturing only the liquid resin, and further improvement of the selectivity of the liquid resin is desired. It is rare.

The liquid resin referred to in the present invention means, for convenience, a fraction whose boiling point in the aromatic resin is 340 ° C. to 470 ° C. at atmospheric pressure, and the solid resin means a fraction having a boiling point of 470 ° C. or higher. Distinguish solids. In general, the liquid resin means a resin having fluidity at room temperature and is not restricted to this boiling range.

[0014]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a method for producing an aromatic liquid resin which is excellent in heat resistance, has a low volatile content, and has a low odor and which is favorable in handling work in a high yield.

[0015]

The present inventors have completed the present invention as a result of intensive research on a method for improving the liquid resin selectivity without lowering the overall resin yield.
A first aspect of the present invention is to reduce the overall resin yield by post-adding formaldehyde to a reaction system in which a raw material oil and an acid catalyst are preliminarily prepared when reacting the raw material oil and formaldehyde in the presence of an acid catalyst. Instead, it improves the selectivity of the liquid resin.

The second aspect of the present invention is to further improve the selectivity of the liquid resin by making the feed oil and alcohol coexist in the reaction system.

The feedstock oil used in the production method according to the present invention includes toluene, xylene, ethylbenzene, methylethylbenzene, trimethylbenzene, durene,
Benzene derivatives and indane derivatives in which the benzene ring has 1 to 4 substituents having a relatively small number of carbon atoms such as methyl group or ethyl group, such as isodurene, derivatives of various condensed polycyclic aromatic compounds such as naphthalene and anthracene, and There is no particular limitation as long as it is a mixture or a fraction containing a part thereof.

Even if an aromatic compound having a substituent having a relatively large number of carbon atoms such as a propyl group or a butyl group or a non-aromatic compound such as paraffin or naphthene is contained, these compounds are treated with formaldehyde. Since it has low reactivity or does not have reactivity at all, it simply acts as a solvent, and the yield of the liquid resin apparently decreases, but especially when the above-mentioned reactive aromatic compound is contained in the feed oil. No problem.

However, it is necessary to consider the content of the reactive aromatic compound in the feedstock when determining the molar ratio of formaldehyde to the feedstock described later.

In general, toluene, a reformed or cracked mixed xylene fraction, a C ₉ or C ₁₀ aromatic fraction obtained from a bottom oil of xylene production or isomerization, etc. are practically preferable feedstocks. Become.

The formaldehyde used in the present invention is
Any form of starting material may be used as long as it produces monomeric formaldehyde in the reaction system, and for example, commercially available various concentrations of formalin or trioxane, polymers such as paraformaldehyde, etc. are used as they are. However, paraformaldehyde, which is easily available at a low price, is the most suitable.

It is also possible to dissolve gaseous formaldehyde separately generated by some method in a raw material oil, a solvent or the like and charge it in the reaction system.

The catalyst used in the present invention is not particularly limited as long as it is an acid catalyst, and sulfuric acid, phosphoric acid, pyrophosphoric acid, perchloric acid, paratoluenesulfonic acid, boron trifluoride, hydrogen fluoride,
Aluminum chloride, various solid acid catalysts and the like can also be used. Sulfuric acid is advantageous because it is cheap and easy to reuse.
Various concentrations of sulfuric acid can be used.

In the present invention, since excess feed oil or unreacted compound in the feed acts as a solvent, a solvent is not always necessary, but if necessary, a solvent not involved in the reaction (eg, isoparaffin) may be added in an appropriate amount. You can

When alcohol is added, the alcohol used in the present invention is not particularly limited as long as it does not adversely affect this reaction. Therefore, normal alcohols and isoalcohols such as methanol, ethanol, n
-Propyl alcohol, isopropyl alcohol, n-
Butyl alcohol, isobutyl alcohol, isoamyl alcohol, 2-ethylhexyl alcohol, n-nonyl alcohol, n-decyl alcohol, etc., or a mixture thereof can be used.

Preferably, the alcohol having 1 to 8 carbon atoms is used alone or in a mixture thereof. When an alcohol having 9 or more carbon atoms is used, a trace amount of alcohol may remain in the alcohol removal operation after the reaction. In such a case,
May have a slight alcohol odor.

Since the alcohol having 1 to 2 carbon atoms has a low boiling point, it is necessary to devise it so that the alcohol does not evaporate and lose from the reaction apparatus during the resinification reaction. Consideration should be given to equipment, operating cost and safety. Will be needed. More preferably, n-
Propyl alcohol, i-propyl alcohol and n-butyl alcohol are preferred.

The reaction apparatus according to the present invention may be of ordinary batch type, semi-flow type, flow type or the like regardless of the shape, but the batch type is the most practical.

When alcohol is added, the molar ratio of the alcohol to the reactive aromatic compound in the feed oil is 0.1 to 0.5, more preferably 0.2 to 0.3.
Is appropriate. The addition time may be any time before addition of formaldehyde.

The amount of the catalyst used in this reaction cannot be specified unconditionally because it is closely related to the reaction conditions. For example, when sulfuric acid is used as the catalyst, the molar ratio of sulfuric acid to reactive aromatic compound is 0.5 or less. , Preferably a molar ratio of 0.2-0.
3 is appropriate.

On the other hand, the molar ratio of formaldehyde to the reactive aromatic compound is not particularly limited. Generally, when the molar ratio is high, the overall resin yield increases, but the selectivity of the liquid resin decreases and the molar ratio decreases. When is low, the overall resin yield is low, but the liquid resin selectivity is high.

Therefore, an optimum molar ratio naturally exists depending on the type of raw material oil and reaction conditions, and the optimum molar ratio is generally about 0.2 to 0.6.

The first feature of the present invention resides in the method of adding formaldehyde, which is to add formaldehyde afterwards to a reaction system in which a feed oil, an alcohol (when alcohol is used) and a catalyst are previously charged. Formaldehyde is preferably added until the temperature in the reaction system reaches from the room temperature to the reaction temperature described below. When formaldehyde is added, the resinification reaction begins and heat is generated at a reaction rate according to the temperature in the system at that time. Therefore, if formaldehyde is added rapidly, there is a risk of exceeding the reaction temperature. The means for suppressing the heat generation below the reaction temperature is not particularly limited, but generally a method of adding little by little may be adopted.

The reaction temperature of this reaction cannot be specified unconditionally because it depends on the type and amount of the feed oil and catalyst, but it is generally 60 to 180 ° C, preferably 80 to 120 ° C.

The reaction time of this reaction cannot be specified unconditionally because it depends on the type and amount of the feed oil and catalyst, but it is generally 0.5 to 10 hours, preferably 1 to 3 hours. The reaction time and reaction temperature in this reaction refer to the reaction in which a resin that does not contain oxygen atoms is generated after charging all of the feed oil, alcohol (when used), catalyst, and formaldehyde, and the reaction temperature is reached. It does not include the pre-reaction step before the treatment.

In order to obtain the target aromatic liquid resin from the reaction product, catalyst removal, washing (removal of a trace amount of acidic substance), unreacted oil, solvent (when used) and heavy product removal are required. Although necessary, these can be implemented by the methods described below.

The catalyst separation can be carried out as it is, or by adding an appropriate diluting solvent and carrying out an ordinary oil-water separation operation. The recovered catalyst is diluted with water generated during the reaction, but it can be reused as it is or by adding a high-concentration acid to adjust the concentration.

The washing step is a step for preventing the quality deterioration of the product due to the mixing of a trace amount of the acidic substance. Usually, a method of repeating neutralization treatment with alkaline water and washing with water or warm water is adopted.

The washed oil layer contains alcohol (when used), unreacted oil, and resin. Therefore, in order to isolate the aromatic liquid resin of the product, it is necessary to remove the alcohol, unreacted oil, and heavy products of the produced resin. It can be carried out or can be carried out in multiple stages.

That is, it is possible to employ a multi-step operation in which alcohol and unreacted oil are removed simultaneously or separately by ordinary atmospheric distillation or an operation such as an evaporator, and then the aromatic liquid resin of the product is recovered by vacuum distillation. Alternatively, it is possible to adopt a one-step operation of recovering the aromatic liquid resin having a boiling point range according to the required properties while gradually increasing the degree of pressure reduction using an ordinary vacuum distillation apparatus.

The distillation temperature range cannot be unconditionally specified because it depends on the type of the feedstock oil and the required properties of the target aromatic liquid resin, but it is usually under a reduced pressure of 5 mmHg or less, preferably under a reduced pressure of 2 mmHg or less and converted to atmospheric pressure 340 The desired aromatic liquid resin is obtained from the fraction at 470 ° C.

[0042]

EXAMPLES Examples will be shown below for clarifying the contents of the present invention, but this is an example.
It is not limited to this.

In the practice, the odor of the produced aromatic liquid resin was subjected to a sensory test at room temperature, and the volatilization loss was measured according to JIS K.
According to 2540, it was measured as volatile matter after 3 hours at 105 ° C.

The heat resistance of the liquid resin is the appearance (hue) after 30 g of a sample is placed in a glass container (30 mmφ × 100 mm) and aged in a gear oven at 105 ° C. for 72 hours.
The change was observed.

[0045]

Example 1 A C ₉ aromatic having a boiling point range of 150 to 180 ° C. of a bottom oil of a reforming type xylene having a composition shown in Table 1 as a feed oil in a four-necked flask equipped with a stirrer and a reflux condenser. A fraction of 720 g was charged, and 203 g of 85% diluted sulfuric acid (JIS K 8951 was diluted) and 89 g of n-butyl alcohol (reagent) were added with gentle stirring.

After that, the temperature rise was started with vigorous stirring,
78.5 g of commercial industrial 92% paraformaldehyde (Sumitomo Chemical Co., Ltd.) was added little by little over about 100 minutes. The system temperature at the start of addition is 35 ° C, and at the end 60 ° C
Met. After that, the temperature is raised by heating, and the reaction temperature is 100 to 105.
Reacted at ℃ for 1 hour.

After completion of the reaction, the mixture was cooled to room temperature, and the contents were transferred to a separating funnel and allowed to stand, so that a sulfuric acid layer was separated into a lower layer, which was removed. Subsequently, washing with water was repeated 2-3 times until the pH of the washing water showed 7.

The obtained oil layer was transferred to a distillation flask, and unreacted oil and the like were first removed by vacuum distillation at 10 mmHg to obtain 555 g as the total amount of aromatic resin.

Next, the degree of reduced pressure was raised to 1 mmHg to obtain 538 g of the target aromatic liquid resin in the fraction up to 340 to 470 ° C. at atmospheric pressure. Table 2 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0050]

[Example 2] Using the same apparatus as in Example 1, the amount of n-butyl alcohol was reduced to 45 g, the same raw material oil as in Example 1 was used, and the reaction and catalyst removal / water washing were performed under the same conditions.
When the vacuum distillation was carried out under the same conditions, the aromatic resin 5
33 g of the target aromatic liquid resin 482 g was obtained.

Table 2 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0052]

Example 3 Using the same apparatus as in Example 1, using 72 g of isopropyl alcohol (reagent) in place of n-butyl alcohol (reagent) as alcohol, the same raw oil as in Example 1 was used, and the reaction was performed under the same conditions. After removing the catalyst and washing with water,
When the vacuum distillation was carried out under the same conditions, the aromatic resin 5
53 g and 506 g of the target aromatic liquid resin were obtained.

Table 2 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0054]

[Example 4] Using the same equipment as in Example 1, the same feed oil as in Example 1 was used except that paraformaldehyde was charged between an internal temperature of 20 ° C and 42 ° C, reaction under the same conditions and catalyst removal / washing with water. After that, vacuum distillation was carried out under the same conditions to obtain 486 g of an aromatic resin and 381 g of a desired aromatic liquid resin.

Table 2 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0056]

[Example 5] The same apparatus as in Example 1 was used, except that paraformaldehyde was charged between the system temperature of 35 ° C to 100 ° C, the same feed oil as in Example 1, reaction under the same conditions and catalyst removal / washing with water. After that, vacuum distillation was carried out under the same conditions to obtain 553 g of an aromatic resin and 532 g of a desired aromatic liquid resin.

Table 2 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0058]

[Example 6] Using the same equipment as in Example 1, except that no alcohol was used, the same feed oil as in Example 1 was used, the reaction and catalyst removal / water washing were performed under the same conditions, and then vacuum distillation was performed under the same conditions. As a result, 585 g of an aromatic resin and 390 g of a desired aromatic liquid resin were obtained.

Table 2 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0060]

Comparative Example 1 720 g of the same stock oil as in Example 1 and 78.5 g of commercially available industrial 92% paraformaldehyde were added to the same apparatus as in Example 1, and 85% sulfuric acid was slowly stirred (JIS K 8951 was diluted). 203 g about 1
The solution was added dropwise little by little over 00 minutes, heated to 100 to 105 ° C., and reacted for 1 hour with vigorous stirring. After the completion of the reaction, the same treatment as in Example 1 was carried out to obtain 562 g of an aromatic resin and 246 g of a desired aromatic liquid resin.

Table 3 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0062]

Comparative Example 2 Using the same apparatus as in Example 1, 89 g of n-
When the reaction was carried out under the same raw material oil and under the same conditions as in Comparative Example 1 except that butyl alcohol was used, 585 g of an aromatic resin and 274 g of a desired aromatic liquid resin were obtained.

Table 3 shows the yields of the obtained aromatic resin and aromatic liquid resin, and the odor, volatile matter and heat resistance of the liquid resin.

[0064]

[Comparative Examples 3 to 5] As conventional liquid resins, C ₉ series liquid resins (Neopolymer L manufactured by Nisseki Chemical Co.
0 ”), xylene resin (“ Nicanol L ”manufactured by Mitsubishi Gas Chemical Co., Ltd.
L ”) and coumarone liquid resin (“ ESCLON L-20 ”manufactured by Nippon Steel Chemical Co., Ltd.). Table 3 shows the results of odor, volatile matter, and heat resistance.

[0065]

[Table 1]

[0066]

[Table 2]

[0067]

[Table 3]

[0068]

From the results shown in Table 2, it can be seen that the present invention can improve only the selectivity of the liquid resin without lowering the overall resin yield and is extremely useful industrially.
When alcohol is added, the selectivity of the liquid resin is significantly improved.

The aromatic liquid resin obtained by the present invention has excellent properties such as high heat resistance and low volatile content and odor. Therefore, it can be used in a wide variety of industries such as tackiness / adhesives, paints and plastic processing. It can be used very suitably for applications such as modifiers and softeners in the field.

Claims (7)

[Claims] 1. An aromatic compound or a distillate containing an aromatic compound as a main component is reacted with formaldehyde in the presence of an acid catalyst to prepare an aromatic liquid resin. A process for producing an aromatic liquid resin, which comprises charging a fraction containing a main component and an acid catalyst and subsequently adding a predetermined amount of formaldehyde. 2. The aromatic liquid according to claim 1, wherein a predetermined amount of alcohol is added when the aromatic compound or the fraction containing the aromatic compound as a main component and the acid catalyst are charged in the reaction vessel in advance. Resin manufacturing method. 3. An aromatic compound or a fraction containing an aromatic compound as a main component, toluene, reforming-type or cracking-type mixed xylene, or carbon number 9 to 10 obtained from bottom oil of xylene production or isomerization. 3. The method for producing an aromatic liquid resin according to claim 1, wherein one aromatic distillate is used. 4. The method for producing an aromatic liquid resin according to claim 1, wherein paraformaldehyde is used as formaldehyde and sulfuric acid is used as a catalyst. 5. The method for producing an aromatic liquid resin according to claim 1, wherein formaldehyde is added at a temperature within the reaction system at a temperature not higher than the reaction temperature. 6. The method for producing an aromatic liquid resin according to claim 1, wherein an alcohol having 1 to 8 carbon atoms or a mixture thereof is used as the alcohol. 7. The method for producing an aromatic liquid resin according to claim 6, wherein an alcohol having 3 or 4 carbon atoms or a mixture thereof is used as the alcohol.