JP2566302B2 - Hue improvement method of alcohol for plasticizer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for improving the hue of a plasticizer alcohol.

[Conventional technology]

The alcohol used as a raw material for producing an ester plasticizer by the reaction with an acid such as carboxylic acid or phosphoric acid or a derivative thereof is not particularly limited as to its origin (production method), and Ziegler method, oxo method and paraffin method are used. Any of higher alcohols (alcohols having 5 or more carbon atoms) produced by an oxidation method or the like is used.

When the above higher alcohol is used as a plasticizer raw material, it is required that the sulfuric acid coloring test result is good, but trace impurities contained in the alcohol, such as aldehydes, ketones, esters, etc. Therefore, the sulfuric acid coloring test results are markedly deteriorated. Therefore, trace impurities contained in alcohol are removed by distillation purification, a combination of a physical treatment method with an adsorbent and the like, and a chemical treatment method.

[Problems to be Solved by the Invention]

The alcohol obtained by the above treatment method has a good result in the sulfuric acid coloring test immediately after the treatment.

However, there is a problem that even when these alcohols having a good sulfuric acid coloring test result, the sulfuric acid coloring test result gradually deteriorates when transported and stored in a storage tank (tank, tank, pipe, etc.).

[Means for solving the problem]

The inventors of the present invention have conducted extensive studies on the cause of the deterioration of the sulfuric acid coloring test results in the above-mentioned higher alcohols, and as a result, a small amount of iron components in the material were eluted from the steel storage tank containing the alcohol, and the iron components were It was found that the results of the sulfuric acid coloring test were deteriorated, and the present invention was completed.

That is, the gist of the present invention is characterized in that iron content reduction treatment is performed on a plasticizer alcohol whose hue in a sulfuric acid coloring test has decreased due to storage in a storage tank, and the iron content is 1 ppm or less. It exists in a method for improving the hue of an alcohol for a plasticizer for producing an ester plasticizer.

 Hereinafter, the present invention will be described in detail.

The higher alcohol (hereinafter referred to as raw material alcohol) to which the present invention is applied is an alcohol having 5 or more carbon atoms, preferably an alcohol having 6 to 30 carbon atoms, and more preferably an alcohol having 6 to 20 carbon atoms. The origin (production method) of the raw material alcohol is not particularly limited, and for example, any of the Ziegler method alcohol, the oxo method alcohol, the paraffin oxidation method alcohol, and the Guerbet method alcohol can be used. Practically, in particular, an α-olefin obtained by Ziegler method ethylene low polymerization, or an oxo method obtained by hydroformylation reaction and hydrogenation reaction of an α-olefin obtained by wax decomposition and an olefin obtained by thermal decomposition of naphtha As it is, or after doubling to quaternizing, hydroformylation reaction, optionally condensation reaction, then oxo method alcohol obtained by hydrogenation reaction, or primary alcohol in the presence of alkali or alkali and cocatalyst It is preferable to apply the method of the present invention to a Guerbet alcohol obtained by dehydration condensation reaction and washing the resulting branched double alcohol to remove the catalyst.

The higher alcohol obtained by the above method is a conventional purification method,
For example, by distillative purification (a chemical treatment may be performed before the distillative purification, if desired, to remove components that deteriorate the sulfuric acid coloring test results), the iron component content is 1 wt ppm or less, and the plasticizer performance, especially sulfuric acid It is considered to be a purified alcohol having good quality in the color test results.

However, since it is usually contained in a steel (carbon steel) storage tank (tank, tank, pipe, etc.) and transported or stored, the iron content is gradually mixed and the hue gradually decreases.

In the method of the present invention, such a storage tank (tank,
The iron content is reduced to 1 weight ppm or less by subjecting the alcohol, which has been reduced in hue in the sulfuric acid coloring test, which has been transported or stored in a tank, a pipe or the like) and preserved.

The method for the iron content reduction treatment is not particularly limited, but examples thereof include a separation method by distillation, an excess method with a fine filter, an ion exchange method, an extraction method with a chelating agent, etc. To be Further, the iron content can be reduced to fall within the above range by adding and mixing an alcohol having an iron content of more than 1 ppm with an alcohol having an iron content of less than 1 ppm.

By the above treatment, the iron content in the alcohol is 1% by weight.
It should be below ppm, preferably below 0.5 ppm by weight. If the iron content in the alcohol is more than 1 ppm, the results of the sulfuric acid coloring test will be deteriorated and the plasticizer performance will be deteriorated.

The alcohol that has been subjected to the iron content reduction treatment is promptly subjected to an esterification reaction with an acid such as carboxylic acid or phosphoric acid or a derivative thereof to form an ester plasticizer, but the esterification reaction is preferable. If it requires a storage period before being used for storage, store it in a container that does not substantially mix with iron, such as a stainless steel container, and adjust the iron content.
It can be maintained at 1 ppm or less.

The sulfuric acid coloring test method includes Monsanto method, Eastman method, Sekisui method, etc., but all of them differ only in fine conditions and the main operation is the same, and Monsanto method is generally widely used. The Monsanto method was also adopted in the examples described later, and the measuring method is shown below.

Sample 100 in a washed and dried 300 ml flat bottom flask with stopper
Add ml. 98wt at room temperature below 30 ℃ while stirring the sample
Add 8 ml of% agricultural sulfuric acid in a 25 ml buret at a rate of 2 ml / min. The flask is stoppered and immersed in a water bath at 98 ± 2 ° C for 2 hours. Then, after cooling to room temperature with water, the sample was transferred to a flat-bottom glass colorimetric tube having an inner diameter of 25 mm and a height of 270 mm (100 ml), and visually compared with the same amount of APHA color standard solution in the same colorimetric tube. The APHA value of the same color is used as the measured value.

The composition of the APHA stock solution is as follows.

Put potassium chloroplatinic acid (K ₂ PtCl ₆₎ 1.245g of cobalt chloride _{(CoCl 2 .6H 2 O) 1.000g} 98% or more concentrated sulfuric acid 100ml to 1000ml ml volumetric flask, and dissolved by adding distilled water, with distilled water Make exactly 1000 ml. This liquid is APHA
500, and then proportionally diluted with distilled water to obtain a low APHA color standard solution.

The smaller the APHA value is, the more preferable, but normally, when the APHA value is about 20 or less, it is industrially preferable as the alcohol for plasticizer.

〔Example〕

Next, specific embodiments of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples without departing from the gist thereof.

Reference Example-1 2-Ethylhexanol obtained by subjecting propylene to a hydroformylation reaction, an aldol condensation reaction, and a hydrogenation reaction, followed by distillation and purification was stored in a carbon steel container.
Table 1 shows the results of measuring the iron content of 2-ethylhexanol after storage and the APHA value of the sulfuric acid coloring test (by the Monsanto method described above).

Example-1 About the thing which passed through the membrane filter made from a polytetrafluoroethylene of 0.2 micrometer 2-ethylhexanol 60 days after storing in the reference example-1 Reference example-
When the iron content and APHA value were measured in the same manner as in 1, the iron content was 0.5 wt ppm APHA value 10.

Example-2 2-Ethylhexanol after 120 days of storage in Reference Example-1 was redistilled in a 20-stage glass Oldershaw distillation column at a reduced pressure of 30 mmHg and a reflux ratio of 1, and 95% was distilled. For the iron content and APHA as in Reference Example-1
When the value was measured, the iron content was 0.11 wt ppm APHA value of 10.

〔The invention's effect〕

According to the method of the present invention, as an alcohol for a plasticizer for producing an ester plasticizer, an alcohol having an improved hue in a sulfuric acid coloring test can be obtained.

Claims (1)

(57) [Claims] 1. An ester plasticizer characterized in that iron content is reduced to 1 ppm or less by subjecting a plasticizer alcohol whose hue has been reduced in a sulfuric acid coloring test by storage in a storage tank to an iron content reduction treatment. For improving the hue of alcohols for plasticizers for producing an agent.