JP2000063849A - Method for producing non-carcinogenic aromatic hydrocarbon oil - Google Patents

Abstract

(57) [Summary] [PROBLEMS] Non-carcinogenic, safe and environmentally-friendly, which has the same performance as conventionally used rubber process oils and contains almost no carcinogenic polycyclic aromatic compounds. Provided is a method for producing a petroleum-based aromatic hydrocarbon oil that does not pollute oil. SOLUTION: A carcinogenic polycyclic aromatic compound is selectively extracted and removed by an extraction operation using dimethyl sulfoxide as a solvent from a petroleum aromatic hydrocarbon oil as a raw material, thereby obtaining an aromatic carbon content of 26%. % Or less and a polycyclic aromatic compound content of less than 3.0% is obtained as an extraction residue. [Effect] The aromatic hydrocarbon oil thus obtained has the same performance as that of a conventionally used rubber process oil, and has non-carcinogenic safety. Suitable for product manufacturing.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a carcinogenic polycyclic aromatic compound (hereinafter referred to as PCA (Pol
The present invention relates to a process for producing a substantially non-carcinogenic aromatic hydrocarbon oil containing almost no (ycyclic Aromatics) or DMSO extract). In particular, the present invention relates to a method for producing a petroleum-based aromatic hydrocarbon oil used in the production of rubber, ink products, etc., and is a substantially non-carcinogenic aromatic hydrocarbon oil containing almost no polycyclic aromatic compound. Regarding the manufacturing method of.

[0002]

2. Description of the Related Art Generally, petroleum-based aromatic hydrocarbon oils have a boiling point range of 240 to 240 obtained by vacuum distillation in refining crude oil.
In the solvent extraction refining method of the lubricating oil production fraction at 650 ° C,
It is well known to those skilled in the art that it is produced as a fraction rich in aromatic hydrocarbon compounds. Therefore, although petroleum-based aromatic hydrocarbon oils differ in their properties and chemical compositions depending on the type of crude oil and the conditions of the extraction and refining method, they are basically characterized by containing a considerable amount of aromatic hydrocarbon compounds as components. And

It is well known to those skilled in the art that this petroleum-based aromatic hydrocarbon oil is usefully used as a processing oil for natural rubber used in tires and the like, a rubber processing oil such as SBR, and an extending oil for a raw material SBR. ing. That is, these petroleum-based aromatic hydrocarbon oils utilize the compatibility with the rubber to improve a series of workability in processing the rubber and improve the physical properties of the final rubber product after vulcanization. Has been added for.

In order to develop compatibility with this rubber, these petroleum aromatic hydrocarbon oils are typically ASTM D 2140.
According to the compositional analysis method defined in paragraph 1, the carbon content (hereinafter sometimes referred to as aromatic carbon content, Ca%) forming an aromatic ring, which substantially means the aromatic hydrocarbon compound content, is 27 to
Contains 55%.

[0005]

However, these petroleum-based aromatic hydrocarbon oils contain 10 to 50% of a polycyclic aromatic compound as a component in the aromatic hydrocarbon compound contained as a component. There is. In recent years, according to the EU directive, petroleum products containing 3% or more of this polycyclic aromatic compound are recommended to be carcinogenic, so efforts are being made worldwide to reduce polycyclic aromatic compounds in petroleum products.

Process oils for rubber and extender oils are no exception, and many proposals have been made.
-50524 (GB 2252978, US550413)
5, EP 575400), the viscosity is 32 to 50 cS.
t. The aromatic component by the clay-gel method specified in ASTM D 2007 is 30 to 55% by weight, the saturated hydrocarbon component is 40 to 65% by weight, and the polycyclic aromatic compound or PCA measured by the IP346 method is Although petroleum hydrocarbon oils of less than 3% have been proposed, the aromatic carbon content (Ca%) specified in ASTM D 2140 should reach 26% or more in the range of aromatic components by this clay-gel method. However, it is not suitable as a substitute for the petroleum-based aromatic hydrocarbon oil that has been conventionally used because it cannot exhibit compatibility and affinity with rubber, and especially for SBR and natural rubber. However, it could not be used at all.

Further, in EP 04179801, the aromatic content by the clay-gel method is 50% by weight or more, IP3
As with the present invention, a petroleum-based lubricating fraction obtained by vacuum distillation of a process oil for rubber having a polycyclic aromatic compound content of less than 3% according to the No. 46 test method is further typified by furfural, phenol or n-methylpyrrolidone. A low-temperature extraction treatment with furfural using a countercurrent contact type extraction column using a fraction rich in aromatic hydrocarbon compounds obtained by extraction treatment with a polar solvent (hereinafter also referred to as extract) (column top: 50 ˜90 ° C., tower temperature: 20 to 60 ° C.) to extract and remove polycyclic aromatic compounds to obtain an extraction residual oil. This method is similar to the present invention, but is fundamentally different in the following points.

First, the extraction solvent used is completely different. In the present invention, dimethyl sulfoxide (hereinafter D
(Also referred to as MSO) is used as an extraction solvent because of its high solubility selectivity for polycyclic aromatic compounds.
The solubility selectivity is basically different from that of furfural, which is used in No. 4179801, not only for polycyclic aromatic compounds but also for non-carcinogenic useful aromatic compounds, whose solubility is considerably high.

This difference in dissolution selectivity simultaneously affects the operating conditions for extraction, and in the case of a solvent having a high dissolving power for aromatic hydrocarbon compounds such as furfural, the column top is inevitably 50: 9.
It is necessary to perform a low temperature extraction treatment at 0 ° C., bottom of the column: 20 to 60 ° C., and in the high temperature extraction treatment as in the present invention, useful non-carcinogenic aromatic compounds are also dissolved, and Ca 26% or more Aromatic hydrocarbon oil cannot be obtained in high yield.

On the other hand, in the low temperature extraction treatment, since the extract used as a raw material is a fraction rich in aromatic compounds, it becomes difficult to handle because the aromatic compounds become highly viscous due to molecular aggregation or molecular association at low temperature. However, depending on the temperature, it cannot be practically used for the process.

In the present invention, since dimethylsulfoxide, which has a high solubility selectivity for polycyclic aromatic compounds and low solubility for useful non-carcinogenic aromatic compounds, is used as the extraction solvent, the top of the column: 90-135 C., tower bottom: high temperature extraction treatment of 60 to 115.degree. C. can be applied, and the problem of raw material extract handling does not occur at all.

[0012] In addition, in Japanese Patent Publication No. 7-501346,
Establishing a unique functional relationship between mutagenicity index and physical properties, the process conditions based on which a non-carcinogenic bright stock extract or deasphalted oil was extracted from a hydrocarbon atmospheric distillation bottoms feedstock. Although a manufacturing method has been proposed, in the present invention, the EU of substantially less than 3% PCA is obtained.
It is hard to say that the order has been reached.

In addition, DE4038458 proposes a method by a critical extraction method, and WO9528458 proposes a method by an air oxidation action. However, all of them have low aromatic content and lack affinity with rubber. A petroleum-based aromatic hydrocarbon oil that is not suitable as a substitute for a process oil for rubber, is too costly in terms of technology and process, and simultaneously satisfies the performance and the carcinogenicity recommendation by the EU Directive, that is, PCA of less than 3%. No technically or cost-effective manufacturing method has been proposed. Thus, there is a strong demand for simple and economical production of non-carcinogenic petroleum-based aromatic hydrocarbon oils.

[0014]

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to provide a carcinogenic polycyclic aromatic compound (PCA) as a process oil for rubber.
It is to satisfy this requirement by providing a novel method for producing a non-carcinogenic petroleum-based aromatic hydrocarbon oil having a performance equivalent to that of the current petroleum-based aromatic hydrocarbon oil including.

In particular, an object of the present invention is to selectively extract polycyclic aromatic compounds from currently used petroleum-based aromatic hydrocarbon oils by removing them, and to provide a simple and economically advantageous non-carcinogenic non-carcinogenic agent. It is to provide a novel method for producing a petroleum-based aromatic hydrocarbon oil.

[0016]

[Means for Solving the Problems] A polycyclic aromatic compound according to the IP346 test method having performance equivalent to that of petroleum-based aromatic hydrocarbon oil conventionally used as a process oil for rubber and having carcinogenicity. A novel petroleum-based aromatic hydrocarbon oil containing less than 3% of compounds, which is safe and does not pollute the environment, uses dimethyl sulfoxide, which is excellent in selective solubility of polycyclic aromatic compounds, as a solvent, and is a countercurrent contact type. It is manufactured through an extraction process in which it is mixed and contacted under the most effective operating conditions in an extraction tower.

The dimethyl sulfoxide used in the present invention is a solvent used in the IP346 test method, which is a method for measuring polycyclic aromatic compounds, and is basically excellent in the solubility selectivity of polycyclic aromatic compounds. It is a solvent.

It is well known that dimethyl sulfoxide is also used as an aromatic compound extraction solvent in the lubricating oil refining step, as is the furfural, phenol or n-methylpyrrolidone used in the lubricating oil refining step. (IFP process). However, dimethyl sulfoxide differs slightly in polarity from other solvents,
While other solvents have a high dissolving power to dissolve not only polycyclic aromatic compounds but also useful non-carcinogenic aromatic compounds, dimethyl sulfoxide is a polycyclic aromatic compound with higher polarity than aromatic compounds. It has a feature that it has a high selective solubility for a compound and its dissolving power itself is lower than that of other solvents. Thus, the present invention is realized by preferentially utilizing this feature.

Further, according to the IP346 test method, room temperature (23
(° C) to improve the extraction selectivity of polycyclic aromatic compounds, and to dilute the sample with 10 times or more of cyclohexane and to carry out with a solvent ratio of 25 to improve the contact efficiency and extraction speed of the extraction operation. Has been done. The application of the operating conditions of the IP346 test method is impossible because the room temperature extraction is difficult to handle due to the high viscosity of the raw material extract, and then the dilution of the raw material and the application of the solvent ratio of 25 are as large as the solvent amount. The cost is too high for recovery, and it is not practical in terms of economy and industrialization, and it is necessary to apply appropriate operating conditions as in the present invention.

The inventors of the present invention have earnestly studied, and have succeeded in developing the operating conditions for sufficiently exhibiting the performance of dimethyl sulfoxide, and have completed the present invention. The details of the feedstock to which the details of the present invention are applied and the operating conditions will be described below.

The feed oil used in the present invention has a boiling point range of 240 to 65 obtained by fractional distillation of crude oil (particularly vacuum distillation).
An extracted oil rich in aromatic hydrocarbon compounds, which is obtained by further extracting a lubricating oil fraction at 0 ° C. with a polar solvent represented by furfural, phenol or n-methylpyrrolidone in a lubricating oil refining process, is applied. It Further, aromatic hydrocarbons obtained by extracting the deasphalted oil from which asphalt substances have been removed with a light hydrocarbon such as propane from the vacuum distillation residue with a polar solvent represented by furfural, phenol or n-methylpyrrolidone. Extracted oil rich in hydrogen compounds can also be suitably used as the feedstock of the present invention.

According to the present invention, these raw oils are used for extraction under the operating conditions in which dimethyl sulfoxide, which is excellent in the solubility selectivity of polycyclic aromatic compounds, is used as a solvent, and the performance of the solvent is sufficiently exhibited. This is achieved by obtaining a non-carcinogenic novel petroleum-based aromatic hydrocarbon oil as an extraction residual oil, which is obtained by extracting and removing less than 3% of a polycyclic aromatic compound having an oncogenic property by the IP346 test method.

The extraction equipment used in the present invention is an RDC (Rotating D) having a rotating disk if it is a countercurrent contact type extraction tower.
isc Contactor) and packed tower. Although there are some differences depending on the structure of the extraction tower, in the countercurrent contact type extraction tower, the solvent is fed from the top of the tower and the feedstock oil is fed from the bottom of the tower. The extraction operation is carried out while making countercurrent contact. At this time, the smaller the oil droplet particle size, the larger the contact area with the solvent and the better the extraction efficiency. Therefore, in order to further increase the contact efficiency and the solubility selectivity of the polycyclic aromatic compound, the RDC type that can increase the oil droplet dispersion efficiency in the tower is more preferable.

In the extraction operation, the ratio of the solvent flow rate to the raw material flow rate is called the solvent ratio, which is an important factor that determines the extraction dissolution amount together with the extraction temperature. That is, when the solvent ratio is large, not only the polycyclic aromatic compound but also the useful aromatic compound is dissolved, and conversely, when the solvent ratio is too small, the target polycyclic aromatic compound cannot be sufficiently extracted and removed. .

The solvent ratio is operated in the range of 0.8 to 4.7, and more preferably 1.0 to 4.5 is applied.
When it exceeds 4.7, not only polycyclic aromatic compounds but also useful aromatic compounds are dissolved, and the carbon content of the aromatic hydrocarbons in the extraction residual oil is 26% by the composition analysis method specified in ASTM D 2140. It is less than the range, and an aromatic hydrocarbon oil useful as a process oil for rubber cannot be obtained. 0.8
If it is less than, the polycyclic aromatic compound is not sufficiently removed by extraction,
The polycyclic aromatic compound content of the extraction residual oil exceeds 3.0%, and a non-carcinogenic aromatic hydrocarbon oil cannot be obtained.

What is more important here is that the solvent ratio is in the range of 0.8 to 4.7 in correlation with the polycyclic aromatic compound content of the feedstock and the extraction operation temperature, that is, the feedstock. If the content of polycyclic aromatic compound is high, the column top temperature is increased and the solvent ratio is increased up to 4.7. On the contrary, when supplying a feedstock oil with a low polycyclic aromatic compound content, the operating conditions are changed in a correlative manner so that the extraction temperature and the solvent ratio are both reduced, and the polycyclic aromatic compound content of the obtained extraction residual oil is increased. Is less than 3.0% and the aromatic carbon content is 26% or more, so that the solvent ratio and the extraction temperature are correlated.

The column top temperature is in the range of 90 to 135 ° C, more preferably 95 to 125 ° C. The column top temperature is an important factor that determines the amount of dissolution in the extraction operation and the polarity of the fraction to be dissolved, that is, the solubility in a solvent. The dissolved amount of the above is extremely reduced, and it becomes difficult to reduce the PCA value of the extraction residual oil by the IP346 test method to less than 3.0% by weight. Further, when the temperature exceeds 135 ° C, not only the polycyclic aromatic compound but also the amount of the aromatic compound dissolved increases, and the IP34 of the extraction residual oil is increased.
Although the PCA value by the 6-test method is significantly reduced from 3.0% by weight, the amount of aromatic compounds contained in the PCA value is greatly reduced,
The aromatic carbon content is less than 26%, which makes it difficult to produce an aromatic hydrocarbon oil useful as a process oil for rubber in good yield. Therefore, the column top temperature is preferably 90 to 135 ° C, more preferably 95 to 125 ° C.

The bottom temperature is preferably in the range of 60 to 115 ° C. and should be lower than the top temperature. The temperature at the bottom of the tower utilizes the difference between the temperature at the top of the tower and the internal reflux of the solute, that is, what is dissolved in the solvent at the top of the solute elutes at a lower temperature at the bottom of the tower and is circulated inside the tower to dissolve the extraction operation. It is an important factor for selectivity.

In this sense, it is advantageous to use a lower temperature for the bottom of the column and to set a large temperature gradient with the top of the column. However, if the temperature gradient is too large, the internal reflux becomes too large and flooding, etc. occurs. This is a problem because it causes the phenomenon of and the extraction operation cannot be performed.

Although there is a difference depending on the structure of the extraction tower used, in a countercurrent contact type extraction tower, the feed oil is fed into the tower from the bottom, so the feed temperature of the feed oil is the bottom temperature. However, when the feed temperature of the feedstock of the present invention is less than 60 ° C., the fluid viscosity of the feedstock increases, which requires a large amount of power for pumping up and the contact efficiency in the extraction column. The stirring power for dispersing the raw material oil to raise the temperature is also increased, which raises the process cost, which is a problem. On the other hand, when the temperature exceeds 115 ° C, the temperature gradient with the top of the column becomes small, the dissolution selectivity is lowered, and it becomes difficult to obtain a useful aromatic hydrocarbon oil having an aromatic hydrocarbon compound content of Ca of 26% or more in good yield. Therefore, the bottom temperature is 60
The range of ~ 115 ° C is desirable and should be below the overhead temperature.

For the extraction operation of the present invention, the temperature gradient between the top and the bottom of the tower is not an essential requirement, but the temperature difference is 20 to 4
The most stable extraction operation was achieved when taken at 0 ° C.
Therefore, the column bottom temperature is preferably correlated with the column top temperature, that is, the column top temperature and the column bottom temperature are applied so that the temperature gradient is 20 to 40 ° C.

The extraction residual oil and the extracted oil thus obtained are
It becomes a product through a normal solvent recovery system. The recovered solvent is recycled and used in the extraction tower.

The petroleum-based aromatic hydrocarbon oil of the present invention having an aromatic carbon content of 26% or more and a PCA content of less than 3%, which is obtained from the extraction residual oil, is a conventionally used rubber process oil or ink. It is a non-carcinogenic petroleum-based aromatic hydrocarbon oil that has the same performance as compounded oils and is safe and does not pollute the environment.

Particularly, when the aromatic carbon content is 26% or more,
If it is less than%, the affinity and solubility with rubber will be insufficient, causing the physical properties of the rubber product using it, especially the decrease in tensile strength and elongation, and bleeding if the addition amount is increased. It is an essential requirement for the aromatic hydrocarbon oil of the present invention.

Examples of the present invention will be shown below. The invention will be explained in more detail by the following examples of data obtained from operating conditions exhibiting more prominent features and data given as comparative examples. However, the present invention is in no way limited to these examples.

[0036]

【Example】

[Table 1] Table 1 shows the properties of the feedstock oil used in the present invention. Lubricating oil fractions and deasphalted oil extracts used as feedstock vary depending on the type of crude oil, the conditions of distillation refining method and deasphalting operation, and the severity of solvent extraction method. It is generally, but not exclusively, representative of them. Here, the light lubricating oil fraction means a boiling point range of 260 to 48.
Represents a 0 ° C. lubricating oil fraction, similarly a medium lubricating oil fraction has a boiling point range of 360 to 550 ° C. and a heavy lubricating oil fraction is 370.
Represents a lubricating oil fraction of ˜680 ° C. These raw material oils are used as commercially available process oils for rubber after adjusting physical properties such as viscosity and flash point. The property value of the feedstock oil was measured by the following test method. Density: JIS K 2249 (Crude oil and petroleum products-Density test method and density-mass-volume conversion table) Vibration type density test method Viscosity: JIS K 2283 (Crude oil and petroleum products-Kinematic viscosity test method and viscosity index calculation method) Refractive index: JIS C 2101 (Electrical insulating oil test method) 14.4
By Abbe refractometer Aniline point: JIS K 2256 (Aniline point of petroleum products and mixed aniline point test method) Aromatic carbon content: ASTM D 2140 DMSO extractables: IP346 test

[0037]

[Table 2] Table 2 shows the result of the extraction process according to the present invention. Example 1
Is an extract of light lubricating oil fraction as feedstock, and is subjected to extraction treatment at a column top temperature of 90 ° C., a column bottom temperature of 60 ° C., and a solvent ratio of 3.2 to obtain an aromatic carbon content (Ca) of 28 0.0%
And the extraction oil of DMSO extraction amount (PCA content) 2.6% was obtained with the yield of 51%. Example 2 uses the extract A of the light lubricating oil fraction as the feed oil, and uses the overhead temperature of 115
℃, the bottom temperature of 80 ℃, solvent ratio 1.3 extraction process,
An extracted oil having an aromatic carbon content (Ca) of 27.5% and a DMSO extraction amount of 1.2% was obtained in a yield of 46%. Example 3
Using the extract B of the medium-grade lubricating oil fraction as the feed oil, the tower top temperature is 105 ° C., the tower bottom temperature is 75 ° C., and the solvent ratio is 3.8.
Aromatic carbon content (Ca) 32.5
% And a DMSO extraction of 2.9% was obtained with a yield of 67%. In Example 4, using the extract B of the medium-quality lubricating oil fraction as the feed oil, a tower top temperature of 125 ° C. and a tower bottom temperature of 9
Extraction treatment was performed at 5 ° C. and a solvent ratio of 1.8 to obtain an extracted oil having an aromatic carbon content (Ca) of 29.5% and a DMSO extraction amount of 2.5% in a yield of 59%. Example 5 uses a heavy lubricating oil fraction extract C as a feed oil and uses a column top temperature of 1
Extraction treatment was performed at 15 ° C, a bottom temperature of 90 ° C and a solvent ratio of 3.2, and the aromatic carbon content (Ca) was 33.0% and the DMS was DMS.
Extracted oil with an O extraction amount of 2.7% was obtained in a yield of 69%. In Example 6, the extract C of the heavy lubricating oil fraction was used as the feedstock, and the extraction was carried out at a column top temperature of 130 ° C., a column bottom temperature of 110 ° C., and a solvent ratio of 1.4 to obtain an aromatic carbon content. (Ca) 3
61% of extracted oil with 1.0% and DMSO extraction amount of 2.2%
Obtained in% yield. In Example 7, extraction was carried out at a column top temperature of 110 ° C., a column bottom temperature of 95 ° C., and a solvent ratio of 4.5, using a heavy lubricating oil fraction extract C as a feedstock to obtain an aromatic carbon content. (Ca) 30.5% and DMSO extraction amount 2.
6% extracted oil was obtained with a yield of 72%. In Example 8, using the extract D of the deasphalted oil as the raw material oil under reduced pressure distillation residue, the tower top temperature was 135 ° C., the tower bottom temperature was 115 ° C., and the solvent ratio was 4.
2. The extraction treatment is performed at 2, and the aromatic carbon content (Ca) 26.
Extracted oil of 5% and DMSO extraction of 1.8% was obtained in a yield of 64%. As shown above, the novel petroleum-based aromatic hydrocarbon oil produced by the present invention has a carcinogenic polycyclic aromatic compound content of 3 as defined by the IP346 test method.
%, Which is substantially non-carcinogenic and has an aromatic content Ca of 26% or more specified by ASTM D 2140.

[0038]

[Table 3] Table 3 shows the result of the extraction process not according to the present invention. Comparative Examples 1 to 6 are extraction conditions according to the present invention, that is, a solvent ratio of 0.8 to
5.2, tower top temperature 90-135 ° C, tower bottom temperature 60-11
If any of the conditions in the range of 5 ° C is deviated, the aromatic carbon content is 26% or more and the aromatic carbon content is 26% or more and the PCA content is less than 3.0%. A useful aromatic hydrocarbon oil having a PCA content of less than 3.0% cannot be obtained.

[0039]

[Table 4] Table 4 shows the results of the extraction operation using a solvent not according to the invention. Basically, furfural and phenols have a higher dissolving power for aromatic hydrocarbons than dimethyl sulfoxide, and unless a temperature condition much lower than the extraction temperature condition of the present invention is applied, an aromatic residue useful as an extraction residual oil is obtained. Hydrocarbon oil cannot be collected in good yield. Comparative Examples 6-12
Has applied the extraction temperature condition in consideration of the circumstances, but the yield of the aromatic hydrocarbon oil obtained as the extraction residual oil is still lower than that of the present invention. Also, since the dissolved amount is large, the DMSO extractable content, that is, the PCA content is 3.0
%, But since useful aromatic hydrocarbon compounds are dissolved and extracted, useful aromatic hydrocarbon oil having an aromatic hydrocarbon compound content of Ca 26% or more cannot be obtained as an extraction residual oil. It is specified.

[0040]

[Table 5] Table 5 shows the rubber formulations for evaluating the aromatic hydrocarbon oils obtained according to the invention and the hydrocarbon oils according to the comparative examples as process oils for rubber. The rubber compound used in the study is JIS K 6383 (Synthetic rubber SBR test method) standard compounding table No. used for studying compounded materials such as raw rubber, carbon black and process oil. The compounding system according to the compounding for non-oil-added rubber of 1 was used, and the kneading method by the roll of rubber compounding was also performed by the method described in the same test method.

[0041]

[Table 6]

[Table 7]

[Table 8] Tables 6 to 8 show the aromatic hydrocarbon oil obtained according to the present invention and the present invention based on the results of the examination of the rubber physical properties by the blending of Table 5 of the conventionally used process oil for aromatic rubber. The results of comparative examination of the hydrocarbon oils obtained in Comparative Examples 3, 5, 7, 8 and 10 which are not shown are shown.
The rubber compounding physical properties differ in the reference physical properties depending on the viscosity grade of the applied process oil, so the oils obtained in the examples and comparative examples of the present invention were compared according to the viscosity grade of the raw material oil. . That is, the raw material extract A group is shown in Table 6, the raw material extract B group is shown in Table 7, and the raw material extract C group is shown in Table 8. Since the deasphalted oil extract has no corresponding commercially available process oil, it was added to the group in Table 8. The vulcanization conditions were determined from the results measured by the Japan Synthetic Rubber Curastometer, and were set as constant conditions for all oils. Vulcanization was performed by a press vulcanizer. The physical properties of the product are measured in JIS K 6301 (vulcanized rubber physical test method), tensile strength and 300% tensile stress and elongation in JIS K 6251 (vulcanized rubber tensile test method), and tear strength in JIS K 6252. (Tear test method of vulcanized rubber) and oil bleeding property were evaluated by visual inspection after standing for 48 hours at room temperature.

Example 9 in Table 6 is the result of the examination of the aromatic hydrocarbon oil according to the present invention, and it was confirmed that the compounding properties were comparable to those of the commercially available process oil A of Comparative Example 13. Was done. Comparative Example 14 is a result of studying a hydrocarbon oil not according to the present invention. Particularly, compared with the result of the commercially available process oil of Comparative Example 13, the tensile strength and the elongation are extremely deteriorated, and further, 20 parts of the process oil are mixed. It was confirmed that the oil bleed was unusable.

Examples 10 and 11 in Table 7 are the results of the examination of the aromatic hydrocarbon oil according to the present invention, and show that the compounding properties of the aromatic hydrocarbon oil according to the present invention are comparable to those of the commercially available process oil B of Comparative Example 15. Was confirmed. Comparative Examples 16 and 17 are the results of the study of hydrocarbon oils not according to the present invention. Compared with the results of the commercially available process oil of Comparative Example 15, especially the tensile strength and elongation were extremely poor, and the number of process oil blended parts was further increased. 20
Oil bleeding was observed on the part, and it was confirmed that it was not usable.

Examples 12, 13 and 14 in Table 8 are the results of the examination of the aromatic hydrocarbon oil according to the present invention, and show the compounding properties which are not inferior to those of the commercially available process oil C of Comparative Example 18. It was confirmed to show. Comparative Examples 19 and 20 are the results of the study of hydrocarbon oils not according to the present invention. Compared with the results of the commercially available process oil of Comparative Example 18, especially the tensile strength and elongation were extremely poor, and the process oil blending number Oil bleeding was observed in 20 parts, and it was confirmed that it was not usable.

[0045]

Since the present invention is constructed as described above, it exhibits the effects described below. The present invention is a non-carcinogenic petroleum-based aromatic hydrocarbon having performance equivalent to that of a petroleum-based aromatic hydrocarbon oil containing a carcinogenic polycyclic aromatic compound that has been conventionally used as a process oil for rubber. Hydrogen oil from conventional petroleum aromatic hydrocarbon water oil,
By the solvent extraction method using dimethyl sulfoxide,
A simple and economically advantageous manufacturing method is provided.

Claims (4)

[Claims] 1. A dimethylsulfoxide is used as a solvent, which is brought into mixed contact with a petroleum-based aromatic hydrocarbon oil to selectively extract and remove a polycyclic aromatic compound from the hydrocarbon oil.
Carcinogenic polycyclic aromatic compound content of less than 3% specified in P346 test method and carbon content of forming aromatic compound by composition analysis method specified in ASTM D 2140 26
% Or more of a non-carcinogenic aromatic hydrocarbon oil as a residual oil for production. 2. The extraction treatment with dimethyl sulfoxide is carried out by using a countercurrent contact type extraction tower and a solvent ratio of 0.8 to 4.
7, tower top temperature 90-135 ℃, tower bottom temperature 60-115 ℃
The method according to claim 1, wherein the temperature is lower than the column top temperature. 3. A petroleum-based aromatic hydrocarbon oil used as a raw material is a fraction used for producing a lubricating oil having a boiling point range of 260 to 680 ° C., and furfural, phenol, n-methylpyrrolidone, etc. in the lubricating oil refining step. Claim 1. The extraction oil rich in aromatic hydrocarbon compounds obtained by the extraction treatment with the polar solvent according to claim 1.
Alternatively, the method according to item 2. 4. A petroleum-based aromatic hydrocarbon oil used as a raw material, which is obtained by subjecting deasphalted oil from a vacuum distillation residue to extraction treatment with a polar solvent such as furfural, phenol or n-methylpyrrolidone. Claims 1, characterized in that it is an extracted oil rich in hydrogen compounds.
The method according to any one of items 2 and 3.