A method for preparing liquid coumarone petroleum resin

Abstract

The present invention relates to the technical field of resin preparation, and specifically, to a liquid coumarone petroleum resin and a preparation method thereof. The method comprises the following steps: uniformly mixing an indene fraction A obtained by cracking carbon nine, an indene fraction B obtained by dephenolizing phenol oil, and an indene fraction C obtained by tar separation to obtain a mixture D; and subjecting the mixture D to a first-stage thermal polymerization crosslinking and a second-stage thermal polymerization crosslinking to obtain a liquid coumarone petroleum resin. The method provided by the present invention can effectively prepare a liquid coumarone petroleum resin, and has a high yield, a suitable softening point, and excellent compatibility with rubber.

Description

Technical Field

[0001] The invention relates to the technical field of resin preparation, and in particular to a liquid coumarone petroleum resin and a preparation method thereof. Background Art

[0002] Indene-coumarone resin (coumarone resin for short) has excellent acid resistance, alkali resistance, adhesion, plasticization and reinforcement properties, and is mainly used in related fields such as coatings, adhesives, rubber, and inks. In terms of coating applications, coumarone resin can be made into various coatings, showing excellent acid resistance, alkali resistance, and adhesion. In terms of adhesive applications, the adhesive made of coumarone resin has significantly enhanced adhesion, and can be mixed with paraffin and vinyl resin to manufacture hot-melt adhesives or adhesives with high bonding properties. In terms of ink applications, it can be used in news printing inks, offset printing inks, writing inks, mimeograph inks, etc. At present, the country mainly produces solid coumarone resins, such as rubber, paint, ink, etc. When used by downstream customers, it needs to be heated and dissolved and added to the formula, which increases energy consumption and an unpleasant odor escapes during the heating process, which does not conform to the current trend of energy conservation and environmental protection; at the same time, most of the conventional raw materials of coumarone resins come from the coking industry, where heavy benzene and carbon nine are used as raw materials and obtained through catalytic polymerization. Among them, carbon nine raw material is a by-product of petroleum cracking to produce ethylene, and is a high-quality raw material for producing fine product petroleum resin. Directly using carbon nine as raw material to manufacture heavier coumarone resin causes resource imbalance and waste.

[0003] Chinese invention patent CN105566569B discloses a method for preparing a hydroxy coumarone resin, in which a mixture containing indene is mixed with monomers such as 4-hydroxystyrene or methyl 4-hydroxycinnamate or ethyl 4-hydroxycinnamate in a certain proportion, and copolymerized to form a solid coumarone resin containing hydroxyl groups. The solid form limits its application range. Summary of the invention

[0004] The invention provides a method for preparing a liquid coumarone petroleum resin, comprising the following steps: uniformly mixing an indene fraction A obtained by cracking carbon nine, an indene fraction B obtained by dephenolizing phenol oil, and an indene fraction C obtained by tar separation to obtain a mixture D; performing a first-stage thermal polymerization and crosslinking on the mixture D to obtain an oligomer and coumarone petroleum resin; and performing a second-stage thermal polymerization and crosslinking on the oligomer to obtain the coumarone petroleum resin.

[0005] The one-stage heat polymerization cross-linking has a pressure of 0.6-2 MPa, a temperature of 120-180° C., and a time of 4-10 h.

[0006] The applicant has found that a one-stage heat crosslinking process with a pressure of 0.6-2 MPa, a temperature of 120-180°C, and a time of 4-10 hours can improve the compatibility of the resin with rubber and reduce the odor of the resin. It may be that the specific reaction conditions improve the compatibility between the three indene fractions, increase the chain length and uniformity, and avoid the problem of excessive oligomers caused by phase separation.

[0007] Preferably, the one-stage thermal cross-linking has a pressure of 0.6-1.2 MPa, a temperature of 130-160° C., and a time of 6-8 h.

[0008] More preferably, the one-stage thermal cross-linking has a pressure of 1 MPa, a temperature of 130-160° C., and a time of 6-8 h.

[0009] The pressure of the second-stage thermal cross-linking is 1.2-3 MPa, the temperature is 180-220° C., and the time is 1-3 h.

[0010] Preferably, the pressure of the second-stage thermal polymerization cross-linking is 1.5-2.5 MPa, the temperature is 180-210° C., and the time is 1-2 h.

[0011] Preferably, the pressure of the second-stage thermal polymerization cross-linking is 2 MPa, the temperature is 200° C., and the time is 2 h.

[0012] The weight ratio of the indene fraction A, the indene fraction B and the indene fraction C is (0.6-0.9):1:(0.3-0.8).

[0013] Preferably, the weight ratio of the indene fraction A, indene fraction B and indene fraction C is (0.7-0.9):1:(0.3-0.6).

[0014] Preferably, the weight ratio of the indene fraction A, indene fraction B and indene fraction C is 0.8:1:0.5.

[0015] The mixed material D includes at least one of methyl styrene, dicyclopentadiene, C10 polycyclic olefin, indene, C11 polycyclic olefin, and methyl indene.

[0016] The mixed material D comprises methyl styrene, dicyclopentadiene, C10 polycyclic olefin, indene, C11 polycyclic olefin and methyl indene.

[0017] An antioxidant is added before the second-stage thermal polymerization cross-linking, and the antioxidant includes one of hindered phenols or aromatic amines.

[0018] The added weight of the antioxidant is 0.01-0.1 wt % of the oligomer.

[0019] Preferably, the added amount of the antioxidant is 0.01-0.03 wt % of the oligomer.

[0020] The dephenolized phenol oil is a by-product of the crude benzene refining process, and the tar includes ethylene tar.

[0021] Beneficial Effects

[0022] 1. The raw material indene fraction prepared in this application is derived from petroleum cracking, crude benzene refining, and low-value by-products of ethylene production, which effectively avoids resource waste while reducing production costs.

[0023] 2. This application can effectively improve the resin yield and resource utilization through one-stage thermal polymerization cross-linking and two-stage thermal polymerization cross-linking.

[0024] 3. Adding antioxidant before the second stage thermal polymerization crosslinking, and the added mass of antioxidant is 0.01-0.1wt% of the oligomer, which can match a higher thermal polymerization temperature and improve the weather resistance of liquid coumarone petroleum resin.

[0025] 4. The weight ratio of the indene fraction A, indene fraction B and indene fraction C is (0.6-0.9):1:(0.3-0.8), which improves the molecular structure stability of the coumarone resin and controls the softening point of the resin at 40-55°C.

[0026] 5. The pressure of one-stage thermal cross-linking is 0.6-2MPa, the temperature is 120-180℃, and the time is 4-10h, which can improve the compatibility of resin and rubber and reduce the odor of resin. DETAILED DESCRIPTION

[0027] Embodiment 1:

[0028] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0029] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0030] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 130°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0031] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 2 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0032] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 230g.

[0033] The cracked carbon nine and ethylene tar are both from Maoming Petrochemical, and the dephenolized phenol oil is from Shanxi Yongdong Chemical.

[0034] Embodiment 2:

[0035] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0036] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0037] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 160°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0038] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 2 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0039] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 236g.

[0040] Embodiment 3:

[0041] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0042] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0043] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then raise the temperature to 160°C and react for 8 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0044] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 2 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0045] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 225g.

[0046] Comparative Example 1

[0047] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0048] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating phenol oil from the by-product of crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.5:1:0.5 to obtain a mixture D, weighing 300g.

[0049] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 0.5 MPa, then heat it to 130°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0050] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0051] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 195g.

[0052] Comparative Example 2

[0053] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0054] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0055] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 0.5 MPa, then heat it to 130°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0056] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0057] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 209g.

[0058] Comparative Example 3:

[0059] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0060] Step 1, indene fraction A obtained by separation of carbon nine from petroleum cracking, indene fraction B obtained by separation of phenol oil by-product dephenolization in a crude benzene refining process, and indene fraction C obtained by separation of ethylene tar are mixed in a weight ratio of 1:1:0.5 to obtain a mixture D, weighing 300g.

[0061] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 0.5 MPa, then heat it to 130°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0062] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0063] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 210g.

[0064] Comparative Example 4:

[0065] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0066] Step 1, the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating phenol oil from the by-product of crude benzene refining process, and the indene fraction C obtained by separating ethylene tar are mixed in a weight ratio of 0.8:1:0.2 to obtain a mixture D, weighing 300g.

[0067] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 0.5 MPa, then heat it to 130°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0068] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0069] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 205g.

[0070] Comparative Example 5:

[0071] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0072] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0073] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 130°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0074] Step 3, the resin liquid E is put into the second-stage thermal polymerization cross-linking reactor, filled with nitrogen and pressurized to 2MPa, and then heated to 230°C. The reaction time is 2h. After the reaction is completed, nitrogen is slowly introduced to replace the gas phase in the reactor from the outlet of the reactor cover, and the volatile components and oligomers are recovered through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0075] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 228g.

[0076] Comparative Example 6:

[0077] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0078] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0079] Step 2: Put the mixed material D into a thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then raise the temperature to 160°C and react for 3 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0080] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 2 MPa, then heat it to 200°C and react for 2 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0081] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 209g.

[0082] Comparative Example 7:

[0083] A method for preparing liquid coumarone petroleum resin comprises the following steps:

[0084] Step 1: Mix the indene fraction A obtained by separating carbon nine from petroleum cracking, the indene fraction B obtained by separating the by-product phenol oil from the crude benzene refining process, and the indene fraction C obtained by separating ethylene tar in a weight ratio of 0.8:1:0.5 to obtain a mixture D, weighing 300g.

[0085] Step 2: Put the mixed material D into a thermal polymerization cross-linking reactor, fill it with nitrogen and pressurize it to 1 MPa, then heat it to 160°C and react for 6 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the unreacted and less active components through an external condenser. The remaining material in the reactor is the resin liquid E in the primary stage.

[0086] Step 3: Put the resin liquid E into a two-stage thermal polymerization and cross-linking reactor, fill it with nitrogen and pressurize it to 2MPa, then heat it to 200°C and react for 4 hours. After the reaction, slowly introduce nitrogen to displace the gas phase in the reactor from the outlet of the reactor cover, and recover the volatile components and oligomers through an external condenser. The remaining material in the reactor is liquid coumarone resin liquid.

[0087] Step 4: Cool the second-stage thermal polymerization and cross-linking reactor to 80°C, add liquid antioxidant from the reactor feed port, stir to fully mix the antioxidant and liquid coumarone resin, turn off heating and stirring, cool to room temperature using the inner coil, open the reactor and take out the resin, which weighs 213g.

[0088] Performance Testing Methods and Data

[0089] The performance of the liquid coumarone resin prepared in the examples and comparative examples was tested, and the test data are listed in Table 1.

[0090] Among them, the odor testing method is: smell the experimental products at different temperatures such as room temperature, 60℃, 100℃, etc., and classify them according to the odor size based on the unique aroma of aromatic hydrocarbons.

[0091] Test method for compatibility with rubber: Use wax mist point test method ASTM D938, mix the obtained experimental products with rubbers such as EVA and SBC, and then conduct wax mist point test. The lower the wax mist point, the better the compatibility (wax mist point between 30-60℃ is good, 60-100℃ is average).

[0092] Resin yield: Resin yield = weight of liquid coumarone resin obtained in the experiment / weight of mixed material D

[0093] Softening point: GB T 4507-2014

[0094] Table 1

[0095]

[0096] From the analysis of Table 1, it can be seen that the influence of raw material ratio on product indicators is that the softening point increases and the resin yield increases with the increase of the proportion of indene fraction of cracked carbon nine, and the softening point increases and the resin yield increases with the increase of the proportion of light components of ethylene tar; the influence of thermal polymerization cross-linking pressure on product indicators is that when other conditions remain unchanged, the thermal polymerization cross-linking pressure increases, the softening point increases, and the compatibility of resin and rubber is significantly improved; the influence of thermal polymerization cross-linking temperature on product indicators is that when other conditions remain unchanged, the thermal polymerization cross-linking temperature increases, the resin yield increases, the softening point increases, and the resin odor decreases; the influence of thermal polymerization cross-linking time on product indicators is that when other conditions remain unchanged, the thermal polymerization cross-linking time increases, the softening point increases, and the odor and compatibility of the resin are improved.

Claims

1. A method for preparing a liquid coumarone petroleum resin, characterized in that: The method comprises the following steps: uniformly mixing an indene fraction A obtained by cracking carbon nine, an indene fraction B obtained by dephenolizing phenol oil, and an indene fraction C obtained by tar separation to obtain a mixture D; subjecting the mixture D to a first-stage thermal polymerization and crosslinking to obtain oligomers and coumarone petroleum resin; and subjecting the oligomers to a second-stage thermal polymerization and crosslinking to obtain coumarone petroleum resin.

2. The method for preparing liquid coumarone petroleum resin according to claim 1, characterized in that: The one-stage heat polymerization cross-linking has a pressure of 0.6-2 MPa, a temperature of 120-180° C., and a time of 4-10 h.

3. The method for preparing liquid coumarone petroleum resin according to claim 2, characterized in that: The one-stage heat polymerization cross-linking has a pressure of 0.6-1.2 MPa, a temperature of 130-160° C., and a time of 6-8 hours.

4. The method for preparing liquid coumarone petroleum resin according to claim 3, characterized in that: The pressure of the second-stage thermal cross-linking is 1.2-3 MPa, the temperature is 180-220° C., and the time is 1-3 h.

5. The method for preparing liquid coumarone petroleum resin according to claim 4, characterized in that: The pressure of the second-stage thermal cross-linking is 1.5-2.5 MPa, the temperature is 180-210° C., and the time is 1-2 h.

6. The method for preparing the liquid coumarone petroleum resin according to claim 1 or 5, characterized in that: The weight ratio of the indene fraction A, the indene fraction B and the indene fraction C is (0.6-0.9):1:(0.3-0.8).

7. The method for preparing liquid coumarone petroleum resin according to claim 6, characterized in that: The mixed material D includes at least one of methyl styrene, dicyclopentadiene, C10 polycyclic olefin, indene, C11 polycyclic olefin, and methyl indene.

8. The method for preparing the liquid coumarone petroleum resin according to claim 1 or 7, characterized in that: An antioxidant is added before the second-stage thermal polymerization cross-linking, and the antioxidant includes one of hindered phenols or aromatic amines.

9. The method for preparing liquid coumarone petroleum resin according to claim 8, characterized in that: The antioxidant is added in an amount of 0.01-0.1 wt % of the oligomer.

10. The method for preparing liquid coumarone petroleum resin according to claim 9, characterized in that: The dephenolized phenol oil is a by-product of the crude benzene refining process, and the tar includes ethylene tar.

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