阅读说明：本技术 石蜡的制造方法 (Method for producing paraffin wax ) 是由 原田耕佑 木户口聪 吉村悠 岩崎俊之 于 2020-11-06 设计创作，主要内容包括：一种石蜡的制造方法,其具备如下工序：将包含正链烷烃的未纯化蜡与汉森溶解度参数中的极性力分量(δp)为4～8且氢键力分量(δh)为3～10的溶剂进行混合而得到混合液的工序；和,从混合液分离固体物而得到正链烷烃浓度更高的石蜡的工序。(A method for producing paraffin wax, comprising the steps of: a step of mixing an unpurified wax containing n-paraffins with a solvent having a polar force component (δ p) of 4 to 8 and a hydrogen bonding force component (δ h) of 3 to 10 in the hansen solubility parameter to obtain a mixed solution; and a step of separating the solid from the mixed liquid to obtain paraffin having a higher normal paraffin concentration.)

1. A method for producing paraffin wax, comprising the steps of:

a step of mixing an unpurified wax containing n-paraffins with a solvent having a polar force component (δ p) of 4 to 8 and a hydrogen bonding force component (δ h) of 3 to 10 in the hansen solubility parameter to obtain a mixed solution; and the combination of (a) and (b),

and a step of separating a solid from the mixed liquid to obtain paraffin having a higher normal paraffin concentration.

2. The manufacturing method according to claim 1, wherein the solvent does not contain a toxic substance and a toxic substance or a hazardous substance specified in a hazardous substance control method.

3. The production method according to claim 1 or 2, wherein the heat of evaporation of the solvent is 500kJ/L or less.

4. The production method according to any one of claims 1 to 3, wherein the unpurified wax and the solvent are mixed so that a mass ratio of the solvent to the unpurified wax, that is, a mass of solvent/a mass of unpurified wax, is 5/1 to 1/2.

5. The production method according to any one of claims 1 to 4, wherein the separation coefficient calculated by the following formula is 5 or more,

(Cw/(1-Cw))/(C0/(1-C0))

where Cw and C0 represent the n-paraffin concentration in the paraffin wax and the n-paraffin concentration in the unpurified wax, respectively.

6. The production method according to any one of claims 1 to 5, further comprising: selecting a solvent with a polar force component (delta p) of 4-8 and a hydrogen bond force component (delta h) of 3-10 in the Hansen solubility parameter.

Technical Field

The present invention relates to a method for producing paraffin wax.

Background

A method of dewaxing a feedstock oil of a lubricating oil using a solvent such as MEK (methyl ethyl ketone) or toluene is known.

Patent document 1: japanese laid-open patent publication No. 55-123687

Disclosure of Invention

The solid precipitated by the above method is filtered and recovered to obtain paraffin. However, the above method is not preferable in terms of productivity because a large amount of solvent is used and the wax must be precipitated at a low temperature. Further, this method is also environmentally undesirable because MEK or toluene is used.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel method for producing paraffin.

The present invention relates to a method for producing paraffin, which comprises the following steps: mixing an unpurified wax containing n-paraffins with a solvent having Hansen Solubility Parameters (HSP) in which the polar force component (δ p) is 4 to 8 and the hydrogen bonding force component (δ h) is 3 to 10 to obtain a mixed solution; and a step of separating the solid from the mixed liquid to obtain paraffin having a higher normal paraffin concentration. According to the present invention, oil and the like can be removed from wax with good efficiency and selectivity.

In one embodiment, the solvent may not contain a toxic substance and the toxic substance or the hazardous substance specified in the hazardous substance control method. In the present invention, the paraffin can be washed with only a highly safe solvent.

In one embodiment, the heat of vaporization of the solvent may be 500kJ/L or less.

In one embodiment, the unpurified wax and the solvent may be mixed so that the mass ratio of the solvent to the unpurified wax (mass of solvent/mass of unpurified wax) is 5/1 to 1/2.

In one embodiment, the separation coefficient calculated by the following formula may be 5 or more.

(Cw/(1-Cw))/(C0/(1-C0))

(wherein Cw and C0 represent the normal paraffin concentration in paraffin wax (purified wax) and the normal paraffin concentration in unpurified wax, respectively.)

In one aspect, the manufacturing method may further include: a solvent having a polar force component (δ p) of 4 to 8 and a hydrogen bonding force component (δ h) of 3 to 10 in HSP is selected.

According to the present invention, a novel method for producing paraffin can be provided. The manufacturing method of the present invention has the following 3 features.

Excellent cleaning properties: the normal paraffin concentration in the wax increases by the washing operation. For example, the separation coefficient described later may be 5 or more.

Excellent selectivity: the dissolution of the normal paraffin in the unpurified wax into the solvent can be sufficiently suppressed. For example, the normal paraffin recovery rate described later can be 85% or more.

Low toxicity: the HSP is focused on, so that it is possible to design a solvent without using toxic substances and toxic and harmful substances specified in the method of controlling harmful substances.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described.

The method for producing paraffin wax according to the present embodiment includes the steps of: a step (mixing step) of mixing an unpurified wax containing normal paraffin with a predetermined solvent to obtain a mixed solution; and a step (separation step) of separating the solid from the mixed liquid to obtain paraffin having a higher n-paraffin concentration. The predetermined solvent is a solvent having a polar force component (δ p) of 4 to 8 and a hydrogen bonding force component (δ h) of 3 to 10 in HSP. Here, the unpurified wax means a wax that is not subjected to the cleaning operation (the mixing step and the separation step) in the present application. The paraffin wax is a wax which is solid at ordinary temperature and contains a straight chain paraffin hydrocarbon (normal paraffin) as a main component.

In the method for producing paraffin, it is important to prepare a solvent having a specific HSP in advance. Therefore, the method for producing paraffin wax may further include the following steps (solvent selection step): a solvent having a polar force component (δ p) of 4 to 8 and a hydrogen bonding force component (δ h) of 3 to 10 in HSP is selected.

The method for producing paraffin wax may be referred to as a method for purifying paraffin wax, from the viewpoint of cleaning and purifying an unpurified wax containing normal paraffin wax with a predetermined solvent. The washing is to separate a solid substance precipitated by mixing an object with a solvent and selectively remove the object except the object. The purification means that the object, which is a crude product, is processed and finished into a product having further good quality.

(mixing Process)

The unpurified wax contains normal paraffins. Here, the normal paraffin refers to a straight-chain saturated hydrocarbon. The content of the n-paraffin in the unpurified wax is not particularly limited, and may be, for example, 10 vol% or more, preferably 30 vol% or more, and more preferably 50 vol% or more, from the viewpoint of purification efficiency. The content may be, for example, 95% by volume or less, preferably 90% by volume or less, and more preferably 85% by volume or less. The n-paraffin content can be quantified by gas chromatography equipped with a nonpolar column and FID (flame ionization detector) operating under a prescribed temperature program. Gas chromatography is an analytical technique for separating and quantitatively analyzing each composition by using the physical properties (boiling point, polarity, etc.) of each composition in a sample.

In the unpurified wax, the average carbon number of the n-paraffins may be 10 or more, preferably 15 or more, and more preferably 20 or more. The average carbon number of the n-paraffins may be 50 or less, preferably 40 or less. The average carbon number is calculated by a weighted average of the n-paraffin concentrations (mass%) of the respective carbon numbers obtained by the gas chromatograph apparatus.

The content ratio of the n-paraffins having 20 or more carbon atoms in the unpurified wax is not particularly limited, and may be, for example, 10 vol% or more, preferably 30 vol% or more, and more preferably 50 vol% or more. The content ratio of n-paraffins having 25 or more carbon atoms in the unpurified wax may be, for example, 5% by volume or more, preferably 15% by volume or more, and more preferably 25% by volume or more.

The unpurified wax also contains other hydrocarbon compounds than normal paraffins. Examples of the other hydrocarbon compounds include isoparaffins, cycloparaffins, and aromatic components. Unpurified wax is purified to remove these compounds, and thus, for example, paraffin wax that can be suitably used for lubricating oil production applications and the like can be produced.

The method for obtaining the unpurified wax is not particularly limited, and examples thereof include the following methods: a method of pressure-filtering mineral oil by means of a filter press; a method of filtering after mixing mineral oil with a solvent; and the like.

As unpurified waxes, it is also possible to use: a solid substance precipitated by adding a low-temperature fluidity improver to a hydrocarbon oil and then leaving the mixture at a low temperature. This method will be briefly described below.

The method for producing an unpurified wax includes, for example, the following steps: a precipitation step in which a low-temperature fluidity improver is added to a hydrocarbon oil having a 10 vol% distillation temperature of 300 ℃ or higher, and a solid is precipitated at a temperature of 5 to 40 ℃; and a separation step of recovering the solid as a non-permeated component by a solid-liquid separation method.

In the precipitation step, a low-temperature fluidity improver is added to a hydrocarbon oil to prepare a mixed oil, and the solid is precipitated at a temperature of 5 to 40 ℃. The 10 vol% distillation temperature of the hydrocarbon oil is 300 ℃ or higher, preferably 320 ℃ or higher. The 90 vol% distillation temperature of the hydrocarbon oil is preferably 480 ℃ or lower, more preferably 460 ℃ or lower. The distillation temperature of a hydrocarbon oil can be determined by JIS (japanese industrial standards) K2254 (petroleum product-distillation test method). The hydrocarbon oil may be derived from heavy light oil, for example. By using such a hydrocarbon oil, a desired amount of wax can be secured at low cost. The deposition step is carried out in the absence of a solvent from the viewpoint of reducing energy required for cooling by increasing the deposition temperature and from the viewpoint of simplifying the step by omitting a separation step with the solvent after mixing.

Hydrocarbon oils contain normal paraffins. The content ratio of the normal paraffins in the hydrocarbon oil is not particularly limited, and may be, for example, 5 vol% or more, preferably 7 vol% or more, and more preferably 10 vol% or more. The content ratio of the normal paraffins in the hydrocarbon oil may be, for example, 20 vol% or less, preferably 17 vol% or less, and more preferably 15 vol% or less.

In the hydrocarbon oil, the average carbon number of the n-paraffins is preferably 23 or more, more preferably 25 or more. In the hydrocarbon oil, the average carbon number of the n-paraffins is preferably 28 or less, more preferably 27 or less.

The content ratio of the n-paraffins having 20 or more carbon atoms in the hydrocarbon oil is not particularly limited, and may be, for example, 7% by volume or more, preferably 8% by volume or more, and more preferably 9% by volume or more. The content ratio of n-paraffins having 25 or more carbon atoms in the hydrocarbon oil may be, for example, 3 vol% or more, preferably 4 vol% or more, and more preferably 5 vol% or more.

The hydrocarbon oil may further contain hydrocarbon compounds other than normal paraffins. Examples of the other hydrocarbon compounds include isoparaffins, cycloparaffins, and aromatic components.

Examples of the low-temperature fluidity improver include ethylene-vinyl acetate copolymers, polyalkylmethacrylates, alkenyl succinimides, polyalkylene oxide fatty acid esters, polyalkylacrylates, alkylnaphthalenes, olefin copolymers, styrene-diene copolymers, and dendrimers. Among them, from the viewpoint of precipitating a wax component having a small oil content and improving the yield in the separation step, an ethylene-vinyl acetate copolymer, a polyalkylmethacrylate, and a polyalkylene oxide fatty acid ester (all of which are low-temperature fluidity improvers for gas oil) are preferable, and an ethylene-vinyl acetate copolymer is more preferable. These may be used alone or in combination of two or more.

When an ethylene-vinyl acetate copolymer is used, the number average molecular weight (Mn) is preferably 6000 or less, more preferably 1000 to 5000, and further preferably 2000 to 4000, from the viewpoint of precipitation temperature. From the viewpoint of inhibiting wax growth, the vinyl acetate content (VA) in the ethylene-vinyl acetate copolymer is preferably 20 mass% or more, more preferably 25 to 60 mass%, and still more preferably 30 to 45 mass%.

The number average molecular weight (Mn) can be determined by JIS (Japanese Industrial standards) K7252 (method for determining the average molecular weight and molecular weight distribution of a polymer by plastic-size exclusion chromatography). The vinyl acetate content (VA) can be determined by JIS (japanese industrial standards) K7192 (plastic-ethylene/vinyl acetate resin (EVAC) -method for measuring vinyl acetate content).

The amount of the low-temperature fluidity improver added to the hydrocarbon oil is preferably 0.01 part by mass or more, more preferably 0.025 part by mass or more, per 100 parts by mass of the hydrocarbon oil, from the viewpoints of the recovery rate of wax and the improvement in fluidity of the hydrocarbon oil. From the viewpoint of reducing the concentration of impurities other than normal paraffins in the obtained wax, the amount is preferably 0.06 parts by mass or less, more preferably 0.05 parts by mass or less, per 100 parts by mass of the hydrocarbon oil.

The pour point of the mixed oil (before the solid is precipitated) obtained by adding the low-temperature fluidity improver to the hydrocarbon oil is preferably 20 ℃ or lower, more preferably 15 ℃ or lower, from the viewpoint of filterability. The lower limit of the pour point is not particularly limited, and may be set to-5 ℃. The pour point can be determined by JIS (japanese industrial standards) K2269 (pour point of crude oil and petroleum product and cloud point test method of petroleum product).

After the low-temperature fluidity improver is added to the hydrocarbon oil, the mixture is placed at a temperature of 5-40 ℃, so that the solid matters are separated from the mixed oil. When the solid is precipitated, stirring by a mixer, a glass rod or the like may be carried out as necessary. The temperature condition is more preferably 15 to 25 ℃ from the viewpoint of maintaining the fluidity of the hydrocarbon oil and reducing the fluctuation in the particle size distribution of the precipitated solid. The particle size distribution can be determined by JIS (japanese industrial standards) Z8825 (particle size analysis-laser diffraction/scattering method) or the like.

The solid precipitated in the hydrocarbon oil in the precipitation step is recovered as a non-permeated component by a solid-liquid separation method. Examples of the solid-liquid separation method include filtration using a solid-liquid separation membrane having a pore size of 2 μm or more at a temperature exceeding 0 ℃ and centrifugation. In the former case, as the filter medium, cloth, net, packed layer, porous material, or the like can be used, and the solid matter can be separated by a filter press, gravity filtration, pressure filtration, vacuum filtration, centrifugal filtration, or the like. As a material constituting the cloth, synthetic fibers, natural fibers, glass fibers, and the like can be used, and specific examples thereof include polypropylene, polyester, polyamide, cotton cloth, and the like. As the mesh, a metal mesh can be used, and as the constituent material, specifically, carbon steel, stainless steel, a mondsia alloy, nickel, aluminum, and the like can be given. As a material constituting the filling layer, sand, clay, activated carbon, or the like can be used. As the porous substance, sintered metal, porous graphite, a separation membrane including an inorganic membrane (a membrane formed of an inorganic material) or the like can be used, and specific examples thereof include a separation membrane including a stainless steel sintered body, a silica membrane, an alumina membrane, a zeolite membrane or the like, a glass filter, and the like. The pore diameter may be measured by a physical measurement method such as an optical microscope, or may be measured by using a retained particle diameter (a particle diameter which is 90% or more when 7 kinds of powder dispersion water defined in JIS (japanese industrial standards) Z8901 are naturally filtered). In the latter case, the solid matter can be separated by a separator such as a separator plate type, a cylinder type, or a decanter type.

The content of the low-temperature fluidity improver contained in the wax varies gradually depending on the initial amount of addition and the production process, and is not particularly limited, and may be 0.01 to 5% by mass, 0.03 to 3% by mass, or 0.05 to 1% by mass.

The content of the low-temperature fluidity improver contained in the wax can be measured by a two-shot method using Fourier transform infrared spectroscopy (FT-IR), Thermal Desorption (TD) -GC/MS in the first stage, and transient thermal decomposition (Py) -GC/MS in the second stage.

The above shows an example of a method for producing unpurified wax.

Next, the solvent used in the method for producing paraffin of the present embodiment has a specific HSP. HSP is a substance whose physical property value is represented by a dispersion force component (δ d) which is energy based on intermolecular dispersion force, a polar force component (δ p) which is energy based on intermolecular polar force interaction, and a hydrogen bond force component (δ h) which is energy based on intermolecular hydrogen bond. Substances having similar HSPs are known to exhibit similar physical properties to each other. According to the findings of the inventors, the polar force component (δ p) and the hydrogen bonding force component (δ h) among these three parameters are important in the present step.

The polar force component (δ p) in the solvent is 4 to 8 and the hydrogen bonding force component (δ h) is 3 to 10, from the viewpoint of obtaining a high cleaning effect (effect of improving the n-paraffin concentration in the wax) with a small amount of the solvent. The polar force component (δ p) is preferably 6 to 8, more preferably 7 to 8. The hydrogen bonding force component (. delta.h) is preferably 5 to 9, more preferably 5 to 7. The dispersion force component (δ d) is not particularly limited, and may be 3 to 18.

The solvent having the HSP as described above can be obtained by appropriately combining known solvents. Among the known solvents, there are, for example, ethanol, acetone, n-hexane, methylcyclopentane and the like as suitable solvents, because the solvents are not toxic substances or harmful substances specified in the method for controlling toxic substances or harmful substances, and because the heat of vaporization of the solvents can be suppressed to a low level. The solvent obtained by combining these solvents does not contain toxic substances such as methyl ethyl ketone and toluene and the toxic substances or the harmful substances specified in the method for controlling a harmful substance. "not containing a toxic substance or a hazardous substance" means that the concentrations of the toxic substance and the hazardous substance are not more than the detection limit concentration (not more than 1 ppm) in the analysis by the gas chromatography apparatus equipped with the FID detector.

As the solvent having the above HSP, a mixed solvent containing acetone is preferably used in view of suppressing the heat of evaporation to a low level. Specifically, acetone, n-hexane, methylcyclopentane, a solvent obtained by mixing any of these, and the like are preferable. The content of acetone in the mixed solvent may be 50% by volume or more, preferably more than 50% by volume, more preferably 60% by volume or more, and still more preferably 75% by volume or more, from the viewpoint of the separation coefficient and the recovery rate of n-paraffin, which will be described later.

From the viewpoint of cost and environmental load, it is realistic to reuse the solvent. For example, the solvent may be recovered by distillation from the solvent in which impurities (for example, hydrocarbon compounds other than normal paraffins) are dissolved after the separation step. In this recovery step, evaporation/condensation of the solvent is repeated, and therefore the heat of evaporation of the solvent is preferably small. From this viewpoint, the heat of vaporization of the solvent may be 500kJ/L or less, preferably 450kJ/L or less, and more preferably 400kJ/L or less. The lower limit of the heat of vaporization is not particularly limited, and may be, for example, 100 kJ/L. The heat of vaporization of the solvent can be measured using a differential scanning calorimeter.

The mixing ratio of the unpurified wax to the solvent is not particularly limited, and the mixing may be performed so that the mass ratio of the solvent to the unpurified wax (mass of the solvent/mass of the unpurified wax) is 5/1 to 1/2. Thus, the amount of solvent used is suppressed, and a high cleaning effect on unpurified wax is easily maintained. The amount of the solvent used is small, so that the loss of the wax component dissolved in the solvent can be reduced. From this viewpoint, the mass ratio is preferably 3/1 to 1/2, more preferably 2/1 to 1/2, and still more preferably 1/1 to 1/2.

(separation Process)

As a method for separating a solid from a mixed liquid of an unpurified wax and a solvent, for example, a solid-liquid separation method can be cited. Specific examples of the solid-liquid separation method include filtration using a solid-liquid separation membrane and centrifugal separation, and the details thereof are as described in the section of the method for producing unpurified wax. The temperature of the mixed solution in the separation step may be set to-10 to 20 ℃.

By the present production method, paraffin wax in which at least 80% by volume of components other than normal paraffin contained in unpurified wax is removed can be obtained.

In the present production method, the separation coefficient calculated by the following formula may be 5 or more, preferably 5.5 or more, and more preferably 6 or more. The upper limit of the separation coefficient is not particularly limited, and may be, for example, 10.

(Cw/(1-Cw))/(C0/(1-C0))

(wherein Cw and C0 represent the normal paraffin concentration in paraffin wax (purified wax) and the normal paraffin concentration in unpurified wax, respectively.)

The content of the normal paraffin in the solid (i.e., the purified wax) depends also on the normal paraffin concentration in the unpurified wax as the raw material, and therefore, is not particularly limited, and may be, for example, 50 vol% or more, preferably 60 vol% or more, and more preferably 80 vol% or more. The upper limit of the content is not particularly limited, and may be, for example, 95 vol% or less.

(solvent selection step)

This step may be performed prior to the mixing step. As described above, a solvent having a desired HSP can be obtained by appropriately combining known solvents. HSP as a solvent can be calculated using computer software or the like, and any known value can be used. In this step, by focusing attention on HSP as a solvent, a highly safe solvent suitable for washing of unpurified wax can be freely prepared.

Examples

The present invention will be described more specifically with reference to examples, but the present invention is not limited to the examples.

< production of Paraffin >

(example 1)

300g of a hydrocarbon oil having a 10 vol% distillation temperature of 324.9%, a 90 vol% distillation temperature of 432.0 ℃ and a pour point of 22.5 ℃ was transferred to a 500mL borosilicate glass beaker (manufactured by Corning Inc.). On the other hand, 0.09g of a low-temperature fluidity improver for light oil of ethylene-vinyl acetate copolymer MD336K (manufactured by Sanyo chemical Co., Ltd.: Mn4000, VA 38% by mass) was placed in a 200mL screw tube (manufactured by Maruemu Corporation), and the mixture was heated in a water bath (manufactured by AS ONE Corporation) at 60 ℃ for 1 hour. The thus prepared low-temperature fluidity improver for gas oil was added to a hydrocarbon oil, and the mixture was stirred and mixed with a glass rod to obtain a mixed oil. The pour point of the mixed oil was 4 ℃.

Subsequently, 45g of the mixed oil was put into a 100mL screw tube (manufactured by Maruemu Corporation), which was allowed to stand in a low-temperature constant-temperature water tank (manufactured by AS ONE Corporation) set at 15 ℃ for 10 minutes. The mixed oil after standing was subjected to vacuum filtration using a vacuum filter KGS-47 equipped with glass filter grade GF/D paraffin (manufactured by Whatman, particle size: 2.7 μm) and a filter flask VT-500 (both manufactured by ADVANTEC). The filtration conditions were as follows: the pressure of the decompression side is-0.95 MPa, the filtration temperature is 15 ℃, and the filtration time is 20 minutes. The filtrate (hydrocarbon oil) was filtered under reduced pressure to obtain 3g of a solid (unpurified wax) and a pour point of 5 ℃ on a glass filter. The normal paraffin concentration in the solid was 45 vol%.

Next, as a solvent, a solvent prepared by mixing 3: 1 (volume ratio) solvent of acetone and n-hexane. HSP and heat of vaporization of the solvent are shown in table 1. HSP of the solvent was obtained using HSPiP software developed by Hansen et al (Windows (registered trademark) software for efficiently operating Hansen Solubility Parameters in Practice: HSP). The software HSPiP can be obtained by the method that the software is shown in the specification of 1 day in 10 months in 2019, http: com/available from/www.hansen-solubility. In the case of a mixed solvent in which a plurality of solvents are mixed, HSP (δ d, δ p, δ h) can be calculated.

The unpurified wax obtained as described above and the solvent were weighed so that the mass ratio thereof was 1: 1, placing the mixture into a 50mL threaded pipe, and fully oscillating to obtain slurry.

The slurry was left to stand in a cryostat (manufactured by AS ONE Corporation) set at 10 ℃ for 10 minutes. The slurry after standing was subjected to reduced pressure filtration using a vacuum filter KGS-47 equipped with Kikusan filter paper No.5A and a filter flask VT-500. The filtration conditions were as follows: the pressure of the pressure reducing side is-0.95 MPa, the filtering temperature is 10 ℃, and the filtering time is 2 minutes. The solid (purified wax) and filtrate were obtained on a tung mountain filter paper by filtration under reduced pressure. The normal paraffin concentration in the solid (purified wax) was 83 vol%. The normal paraffin concentration in the dissolved components other than the solvent in the filtrate separated from the purified wax was 8 vol%.

(other examples and comparative examples)

A solid (purified wax) was obtained in the same manner as in example 1, except that the solvent was changed to the solvent shown in table 1.

[ Table 1]

< evaluation >

(coefficient of separation)

The separation coefficient was calculated according to the following formula. The results are shown in Table 2.

(Cw/(1-Cw))/(C0/(1-C0))

Where Cw and C0 represent the n-paraffin concentrations in the wax after washing (purified wax) and the wax before washing (unpurified wax), respectively.

(recovery of normal paraffin)

The normal paraffin recovery rate was calculated from the following formula. The results are shown in Table 2.

(amount of normal paraffin contained in purified wax/amount of normal paraffin contained in unpurified wax). times.100 (%)

[ Table 2]

In the examples, excellent separation factor and normal paraffin recovery rate were achieved. As a result, the resin was excellent at all compared with the case of using methyl ethyl ketone or toluene (comparative example 6) specified as hazardous substances.