Method for preparing coumarone resin by using ionic liquid catalyst

Abstract

The invention relates to a method for preparing coumarone resin by using an ionic liquid catalyst, which adopts one or more of disubstituted imidazole-aluminum trichloride ionic liquid, tertiary amine hydrochloride-aluminum trichloride ionic liquid and pyridine-aluminum trichloride ionic liquid as a catalyst to produce the coumarone resin. The coumarone resin (the softening point is 90-130 DEG C) with large market demand can be obtained. The ionic liquid catalyst can be recycled for multiple times, subsequent separation is convenient, washing is not needed, wastewater discharge is reduced, the production cost is reduced, and the method is more environmentally friendly and economical.

Description

Technical Field

[0001] The invention belongs to the field of material preparation, and in particular relates to a method for preparing coumarone resin by using an ionic liquid catalyst. Background Art

[0002] Coumarone-indene resin (abbreviated as: coumarone resin) has excellent acid resistance, alkali resistance, adhesion, plasticization and reinforcement properties. It is soluble in chlorinated hydrocarbons, esters, ketones, ethers and other solvents, and has good compatibility with various resins such as natural rubber and epoxy resin. It has long been widely used as a modifier for various resins, mainly used in coatings, electronic materials, adhesives, sealants, rubber, inks and other fields.

[0003] The typical production process of coumarone resin in the prior art includes the steps of distillation and cutting fractions, acid washing and pyridine removal, polymerization, washing, curing and the like, and finally a solid coumarone resin product is obtained.

[0004] Chinese patent CN201510348066.4 discloses a method for preparing coumarone resin, which uses ethylene "butter" as raw material, adds a stabilizer, and uses concentrated sulfuric acid to catalyze the synthesis of coumarone resin. The reaction pressure of the method is 0.2MPa, the reaction temperature is 160°C, and the reaction is carried out for 1 hour under low-speed stirring to obtain coumarone resin. This method has high reaction conditions, the obtained coumarone resin has a low softening point, and the product yield is low.

[0005] Chinese patent CN201610039005.4 discloses "a method for producing modified coumarone resin", using C9 fraction as raw material, 2-cyanoethyl-5-norbornene-2-aldehyde as modifier, cracking the modifier, mixing the C9 fraction with the modifier, prepolymerizing with concentrated sulfuric acid as catalyst, secondary polymerization with boron trifluoride as catalyst, and finally distilling under reduced pressure to obtain coumarone resin with a softening point of 90°C. This method has a long production process, and the synthesized coumarone has a low softening point, and the catalyst used has a large environmental pollution.

[0006] Chinese patent CN201110076405.X discloses a "method for producing coumarone resin", which uses coal tar as raw material, and simultaneously produces solid coumarone resin and liquid coumarone through steps such as de-weighting, hydrogenation reaction, primary separation, dephenolization, depyridineization, and polymerization. The catalyst used in this method is alumina, which has a low yield, and the molecular weight distribution of the coumarone resin synthesized by this method is too wide, resulting in a large softening point distribution.

[0007] Ionic liquids are salts composed entirely of ions that are liquid at low temperatures, also known as low-temperature molten salts. They are generally composed of larger organic cations and smaller inorganic anions, and are used to replace traditional organic solvents and catalysts as green chemical reaction media.

[0008] Among the many liquid phase reactions in which ionic liquids participate, the effects of ionic liquids can be roughly divided into two categories:

[0009] 1. As a green reaction solvent. By utilizing its special solubility for reaction substrates and organic metal catalysts, the reaction is carried out in the ionic liquid phase. At the same time, by utilizing its immiscible characteristics with certain organic solvents, the product enters the organic solvent phase. This can not only achieve good separation of products, but also realize the recovery and reuse of catalysts in the ionic liquid phase simply through physical phase separation.

[0010] Second, functionalized ionic liquids, that is, ionic liquids are used as catalysts in addition to being green reaction media, such as utilizing the inherent Lewis acidity of ionic liquids to catalyze esterification reactions and Friedel-Crafts alkylation reactions.

[0011] The catalysts currently used in the polymerization process of coumarone-indene resin are mainly sulfuric acid, boron trifluoride-ether complex and aluminum chloride, etc. These catalysts are difficult to separate from the product in the subsequent process, which will affect the product yield and quality. In the subsequent catalyst treatment process, water washing is required, which will produce a large amount of wastewater and bring about wastewater problems. In order to solve this problem, it is necessary to develop green and recyclable catalysts to produce coumarone resin products.

[0012] The use of ionic liquids as catalysts not only has high reaction activity and can produce resins of different molecular weights, but also is easy to separate after the reaction. For example, Luo Guohua used coking carbon nine fractions as raw materials and [Et3NH]Cl-AlCl3 ionic liquid to catalyze the polymerization of coking heavy oil in "Preparation of benzofuran-indene resin by chloroaluminate ionic liquid catalyzed coking carbon nine", and investigated the optimal initial temperature of the polymerization reaction and the optimal amount of catalyst added. A coumarone resin with a softening point above 130°C and a conversion rate close to 100% was synthesized. However, the softening point of the synthesized coumarone resin is high and the market demand is small. Summary of the invention

[0013] The present invention aims to provide a method for preparing coumarone resin using an ionic liquid catalyst, which can prepare coumarone resin (softening point 90-130° C.) with a large market demand, and the used ionic liquid catalyst can be recycled. The overall preparation process is more economical and environmentally friendly, and is suitable for industrial production.

[0014] In order to achieve the above object, the present invention provides the following technical solutions:

[0015] A method for preparing coumarone resin using ionic liquid catalysis comprises the following steps:

[0016] 1) mixing the coumarone-indene fraction with a solvent to prepare a raw material oil having an indene content of 1 to 55 wt %;

[0017] 2) washing the obtained crude oil with acid and alkali, and further neutralizing to obtain a crude coumarone fraction;

[0018] 3) decolorizing the crude coumarone fraction to obtain decolorized coumarone fraction oil;

[0019] 4) The decolorized coumarone fraction oil obtained is uniformly mixed with toluene to form a mixed material, and then a catalyst is added to the mixed material, and the reaction is carried out at a temperature of 50 to 80° C. for 1 to 5 hours to obtain a polymerized oil; the catalyst is one or more of disubstituted imidazole-aluminum trichloride ionic liquid, tertiary amine hydrochloride-aluminum trichloride ionic liquid, and pyridine-aluminum trichloride ionic liquid;

[0020] 5) The polymerized oil is washed with water and then distilled to remove the unpolymerized monomers and solvent to obtain a coumarone resin product.

[0021] Preferably, the solvent is one or more of toluene, xylene, p-toluene and flash oil.

[0022] Preferably, in step 4), the mass fraction of the decolorized coumarone distillate in the mixed material is 30-50%.

[0023] Preferably, in step 4), the amount of the catalyst added is 1 to 3 wt %, preferably 1.5 to 2.5 wt % of the mixed material.

[0024] Preferably, in step 4), the catalyst is added at a rate of 0.1 to 0.3 mL / min.

[0025] Preferably, in step 4), the reaction temperature is 60-70°C.

[0026] Preferably, in step 4), the reaction solution is stirred continuously during the reaction.

[0027] Preferably, in step 4), the catalyst is a mixture of one or more of disubstituted imidazolium chloride ionic liquid, disubstituted imidazolium bromide ionic liquid, tertiary amine hydrochloride ionic liquid, pyridinium bromide ionic liquid and anhydrous aluminum chloride.

[0028] Preferably, the molar ratio of one or more of disubstituted imidazolium chloride ionic liquid, disubstituted imidazolium bromide ionic liquid, tertiary amine hydrochloride ionic liquid, pyridinium bromide ionic liquid to anhydrous aluminum chloride is 1:1 to 2.5, preferably, the molar ratio is 1:2.

[0029] Preferably, in step 5), the distillation conditions are an absolute pressure of 8 to 10 kPa and a distillation stop temperature of 190 to 210°C.

[0030] The present invention adopts one or more of disubstituted imidazole-aluminum trichloride ionic liquid, tertiary amine hydrochloride-aluminum trichloride ionic liquid and pyridine-aluminum trichloride ionic liquid as catalyst to produce coumarone resin, and can obtain coumarone resin (softening point 90-130° C.) with large market demand.

[0031] When the reaction temperature is controlled at 50-80°C, if the temperature is too low, the reaction will be incomplete, the time will be long and the yield will be low. If the temperature is too high, the softening point of the product will be too low and the color of the resin will darken.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention adopts one or more of disubstituted imidazole-aluminum trichloride ionic liquid, tertiary amine hydrochloride-aluminum trichloride ionic liquid and pyridine-aluminum trichloride ionic liquid as catalysts to produce coumarone resin. The obtained coumarone resin has a low softening point and the obtained product index can reach the same level as the coumarone resin product finally obtained by a typical production process (the process includes the steps of distillation and cutting fractions, acid washing and pyridine removal, polymerization, washing, curing and the like).

[0034] The ionic liquid catalyst of the present invention can be recycled for multiple times, is easy to separate later, does not need water washing, reduces wastewater discharge, reduces production costs, and is more environmentally friendly and economical.

[0035] The coumarone resin obtained by the invention has a softening point of 90-130 DEG C and a product yield of ≥99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with embodiments and drawings.

[0038] The process parameters of the embodiments of the present invention are shown in Table 1.

[0039] In the embodiment, the ionic liquid is prepared as follows: 3.2 g (0.0183 mol) of 1-butyl-3-methylimidazole chloride is placed in a 150 mL three-necked flask, the temperature is kept constant at 80° C. in a thermostatic bath, 5 g (0.0375 mol) of anhydrous aluminum chloride is gradually added, the mixture is stirred at the constant temperature for 5 hours, and nitrogen is introduced for protection. After the reaction is completed, 1-butyl 3-methylimidazole-aluminum chloride ionic liquid is obtained. The ionic liquid is liquid at room temperature and has a low viscosity. The ionic liquid is sealed and placed in a desiccator for storage.

[0040] Example 1

[0041] See also Figure 1 The method for preparing coumarone resin using an ionic liquid catalyst of the present invention comprises:

[0042] The crude coumarone-indene fraction is subjected to acid washing, alkali washing and decolorization to obtain a decolorized oil CSN, which is then mixed with toluene to obtain a raw material oil with a polymerizable component content of 50%;

[0043] Take 100g of raw oil, add it into a three-necked jacketed reactor and preheat it to 65°C, add 1-butyl-3-methylimidazole-aluminum trichloride ionic liquid, and react for 2 hours. Then, the reaction liquid is centrifuged to recover the bottom ionic liquid, and the upper polymer oil is washed. The polymer oil after acid and alkali washing is distilled at an absolute pressure of 8kPa. After the temperature rises to 190°C, the remaining components in the reactor are the coumarone resin product.

[0044] After weighing, the calculated yield was 99.21% and the measured softening point was 130.0°C.

[0045] Example 2

[0046] A method for preparing coumarone resin using an ionic liquid catalyst comprises:

[0047] The crude coumarone-indene fraction is acid-washed, alkali-washed and decolorized to obtain decolorized oil CSN, which is then mixed with toluene to obtain a raw material oil with a polymerizable component content of 40%;

[0048] 100 g of raw oil was added into a three-necked jacketed reactor and preheated to 80°C. Triethylamine hydrochloride-aluminum chloride ionic liquid was added. After reacting for 2.5 hours, the reaction solution was centrifuged to recover the bottom ionic liquid, and the upper polymer oil was washed. The polymer oil after acid washing and alkali washing was distilled at an absolute pressure of 9 kPa. After the temperature was raised to 200°C, the remaining components in the reactor were the coumarone resin product. The yield was calculated to be 99.41%, and the softening point was measured to be 117.0°C.

[0049] Example 3

[0050] A method for preparing coumarone resin using an ionic liquid catalyst comprises:

[0051] The crude coumarone-indene fraction is acid-washed, alkali-washed and decolorized to obtain decolorized oil CSN, which is then mixed with toluene to obtain a raw material oil with a polymerizable component content of 30%;

[0052] Take 100g of raw oil, add it into a three-necked jacketed reactor and preheat it to 60°C, add triethylamine hydrochloride-aluminum chloride ionic liquid, and react for 3 hours. Then, the reaction solution is centrifuged to recover the bottom ionic liquid, and the upper polymer oil is washed. The polymer oil after acid and alkali washing is distilled at an absolute pressure of 8.5kPa. After the temperature rises to 210°C, the remaining components in the reactor are the coumarone resin product. The yield is calculated to be 99.24%, and the softening point is measured to be 93.7°C.

[0053] Example 4

[0054] A method for preparing coumarone resin using an ionic liquid catalyst comprises:

[0055] The crude coumarone-indene fraction is acid-washed, alkali-washed and decolorized to obtain decolorized oil CSN, which is then mixed with toluene to obtain a raw material oil with a polymerizable component content of 20%;

[0056] 100 g of the raw oil was added to a three-necked jacketed reactor and preheated to 50°C. 1-ethyl-3-methylimidazole-aluminum chloride ionic liquid was added. After reacting for 5 hours, the reaction solution was centrifuged to recover the bottom ionic liquid, and the upper polymer oil was washed. The polymer oil after acid and alkali washing was distilled at an absolute pressure of 10 kPa. After the temperature was raised to 205°C, the remaining components in the reactor were the coumarone resin product. The yield was calculated to be 99.58%, and the softening point was measured to be 124.3°C.

[0057] Example 5

[0058] A method for preparing coumarone resin using an ionic liquid catalyst comprises:

[0059] The crude coumarone-indene fraction is acid-washed, alkali-washed and decolorized to obtain decolorized oil CSN, which is then mixed with toluene to obtain a raw material oil with a polymerizable component content of 10%;

[0060] 100 g of raw oil was added into a three-necked jacketed reactor and preheated to 70°C. 1-ethylpyridinium bromide-aluminum chloride ionic liquid was added. After reacting for 4 hours, the reaction solution was centrifuged to recover the bottom ionic liquid, and the upper polymer oil was washed. The polymer oil after acid and alkali washing was distilled at an absolute pressure of 9.5 kPa. After the temperature was raised to 195°C, the remaining components in the reactor were the coumarone resin product. The yield was calculated to be 99.56%, and the softening point was measured to be 110.4°C.

[0061] Example 6

[0062] A method for preparing coumarone resin using an ionic liquid catalyst comprises:

[0063] The crude coumarone-indene fraction is acid-washed, alkali-washed and decolorized to obtain decolorized oil CSN, which is then mixed with toluene to obtain a raw material oil with a polymerizable component content of 5%;

[0064] 100 g of the raw oil was added to a three-necked jacketed reactor and preheated to 80°C. 1-ethyl-3-methylimidazole-aluminum chloride ionic liquid was added. After reacting for 1 hour, the reaction solution was centrifuged to recover the bottom ionic liquid, and the upper polymer oil was washed. The polymer oil after acid washing and alkali washing was distilled at an absolute pressure of 8 kPa. After the temperature was raised to 200°C, the remaining components in the reactor were the coumarone resin product. The yield was calculated to be 99.67%, and the softening point was measured to be 106.8°C.

[0065] The yield and softening point of the coumarone resin obtained in Examples 3 to 6 were measured. The results are shown in Table 1.

[0066] As can be seen from Table 1, the softening point of the coumarone resin obtained by the present invention is between 90 and 130° C., and the yield is more than 99%.

[0067] Table 1

[0068]

Claims

1. A method for preparing coumarone resin using an ionic liquid catalyst, characterized in that: The following steps are involved: 1) mixing the coumarone-indene fraction with a solvent to prepare a raw material oil having an indene content of 1 to 55 wt %; 2) washing the obtained crude oil with acid and alkali, and further neutralizing to obtain a crude coumarone fraction; 3) decolorizing the crude coumarone fraction to obtain decolorized coumarone fraction oil; 4) The decolorized coumarone fraction oil obtained is uniformly mixed with toluene to form a mixed material, and then a catalyst is added to the mixed material, and the reaction is carried out at a temperature of 50 to 80° C. for 1 to 5 hours to obtain a polymerized oil; the catalyst is one or more of disubstituted imidazole-aluminum trichloride ionic liquid, tertiary amine hydrochloride-aluminum trichloride ionic liquid, and pyridine-aluminum trichloride ionic liquid; 5) The polymerized oil is washed with water and then distilled to remove the unpolymerized monomers and solvent to obtain a coumarone resin product.

2. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1, characterized in that: The solvent is one or more of toluene, xylene, p-toluene and flash oil.

3. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1, characterized in that: In step 4), the mass fraction of the decolorized coumarone distillate oil in the mixed material is 30-50%.

4. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1 or 3, characterized in that: In step 4), the amount of the catalyst added is 1 to 3 wt % of the mixed material, preferably 1.5 to 2.5 wt %.

5. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1, 3 or 4, characterized in that: In step 4), the catalyst is added at a rate of 0.1 to 0.3 mL / min.

6. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1, 3, 4 or 5, characterized in that: In step 4), the reaction temperature is 60-70°C.

7. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1, 3, 4, 5 or 6, characterized in that: In step 4), the reaction solution is stirred continuously during the reaction.

8. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1 or 3 or 4 or 5 or 6 or 7, characterized in that: In step 4), the catalyst is prepared by mixing one or more of disubstituted imidazolium chloride ionic liquid, disubstituted imidazolium bromide ionic liquid, tertiary amine hydrochloride ionic liquid, pyridinium bromide ionic liquid and anhydrous aluminum chloride.

9. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 8, characterized in that: The molar ratio of one or more of disubstituted imidazolium chloride ionic liquid, disubstituted imidazolium bromide ionic liquid, tertiary amine hydrochloride ionic liquid, pyridinium bromide ionic liquid to anhydrous aluminum chloride is 1:1 to 2.5, and the preferred molar ratio is 1:

2.

10. The method for preparing coumarone resin using an ionic liquid catalyst according to claim 1, characterized in that: In step 5), the distillation conditions are an absolute pressure of 8 to 10 kPa and a distillation stop temperature of 190 to 210°C.

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