A low molecular weight, high softening point c9 petroleum resin and a method for making the same

Abstract

The application discloses a low-molecular-weight C9 petroleum resin with high softening point and a preparation method thereof, and aims to provide the low-molecular-weight C9 petroleum resin with high softening point by controlling the content of dicyclopentadiene component and increasing the content of dimethylcyclopentadiene component; the method is prepared through the following steps in sequence: S1, weighing C9 fraction, dimethylcyclopentadiene, a catalyst and a dilution solvent, pouring the weighed C9 fraction, dimethylcyclopentadiene and dilution solvent into a reaction kettle, and then introducing inert gas protection, keeping the pressure in the kettle at 0.01-0.02 MPa, and stirring and mixing; S3, adding the catalyst dropwise into the reaction kettle of S2, gradually heating to 30-50 DEG C, and increasing the pressure to 0.1-0.5 MPa, after the catalyst is added dropwise, the polymerization liquid is obtained after reaction for 2-4 hours; S4, the polymerization liquid obtained in S3 is transported into a neutralization kettle, and a terminating agent is added until the pH value of the polymerization liquid reaches 8-10, and the polymerization reaction is terminated; S5, in the neutralization kettle of S4, 12-24 parts by weight of acid clay is added for decolorization, after uniform stirring, the temperature is kept at 80 DEG C for 2 hours, and the polymerization liquid with a pH value of 7 is obtained through pressure filtration; and S6, the polymerization liquid after pressure filtration is subjected to vacuum and rectification to remove the solvent and oligomers, and the low-molecular-weight C9 petroleum resin with high softening point is prepared.

Description

Technical Field

[0001] This invention discloses a petroleum resin, specifically a low molecular weight C9 petroleum resin with a high softening point. This invention also discloses a method for preparing the low molecular weight C9 petroleum resin with a high softening point, belonging to the field of petroleum technology. Background Technology

[0002] C9 petroleum resin is generally polymerized from styrene, methyl-styrene, dicyclopentadiene, indene, etc. The synthesized resin molecules have a molecular weight of 5000-8000, a softening point of 100-120℃, a relatively large molecular weight, a high wax mist point, a darker color, and poor thermal stability. It cannot be used in hot melt adhesives, glues, inks, etc., and is limited to industries such as paints and tires, thus narrowing its application range. Optimizing the properties of petroleum resins to improve their performance and expand their application scope is a very important research area. Petroleum resins are generally not used alone, but rather as accelerators, regulators, modifiers, and other resins in combination.

[0003] Existing C9 petroleum resins are generally dark in color and have a large molecular weight. They have poor compatibility with synthetic resins such as EVA (ethylene-vinyl acetate copolymer), SIS (styrene-isoprene-styrene copolymer), and SBS (styrene-butadiene-styrene copolymer), as well as synthetic rubbers such as butyl rubber and styrene-butadiene rubber. They are prone to insoluble precipitation, resulting in poor overall applicability and severely limiting the application of C9 petroleum resins in adhesives, rubber, coatings and other fields.

[0004] Therefore, the modification of C9 petroleum resin has always been a research focus. CN202011111858.7 A method to improve the comprehensive utilization rate of C9 fraction from ethylene cracking. The method is as follows: (1) The raw material ethylene cracking C9 fraction is passed through a depolymerization distillation column. Under atmospheric pressure, dicyclopentadiene and dimethylcyclopentadiene undergo a depolymerization reaction. Cyclopentadiene fraction is obtained at the top of the column, and methylcyclopentadiene-rich fraction is obtained on the side stream. The bottom material of the column enters the next processing unit. The depolymerization reaction temperature is 170-210℃, the top temperature is 39-43℃, the side stream temperature is 70-75℃, and the reflux ratio is 1-10. (2) The side stream material obtained in step (1) is fed into an atmospheric pressure distillation column for distillation separation. The top of the column is obtained Cyclopentadiene fraction, methylcyclopentadiene fraction is obtained from the bottom of the column, the bottom temperature is 75-85℃, the top temperature is 39-43℃, and the reflux ratio is 3-12; at the same time, the bottom material obtained in step (1) is fed into the pre-hydrogenation reactor for selective hydrogenation reaction to remove trace amounts of dienes and convert light sulfur into heavy sulfur, the reaction temperature is 80-180℃, the reaction pressure is 1.0-5.0 MPa, and the liquid hourly space velocity is 1.0-10.0 h-1; (3) the material obtained after the hydrogenation reaction in step (2) is fed into the flash distillation column for cutting and separation, the top of the column is a saturated fraction rich in styrene and indene, and the bottom of the column is a mixed fraction of oligomers and polycyclic aromatic hydrocarbons, the bottom temperature is 200-230℃, and the D / F ratio is 0.6. ~0.8, tower top pressure 1~10KPaG; (4) The tower top material obtained in step (3) is fed into the polymerization reactor, and catalytic polymerization reaction is carried out under normal pressure using boron trifluoride ether as catalyst. After neutralization and water washing to remove the catalyst, petroleum resin is generated; wherein, the mass ratio of catalyst to material is 1:(40~100), the reaction temperature is 40~100℃, and the reaction time is 180~360min; at the same time, the tower bottom material obtained in step (3) is fed into the desulfurization reactor, and adsorption desulfurization is carried out using activated clay (commercially available, such as HT-1 from Anji Guangyuan Bentonite Plant), the reaction temperature is 60~120℃, the reaction pressure is 0.5~3.0Mpa, and the liquid hourly space velocity is 0.5. ~3.0h-1; (5) The petroleum resin obtained in step (4) is fed into a hydrogenation reactor and hydrogenated under the action of a skeletal nickel catalyst to obtain high-quality hydrogenated petroleum resin; wherein, the molar ratio of petroleum resin to hydrogen is 1:(2~5), the amount of catalyst is 0.5~3.0wt% of petroleum resin, the reaction time is 120~300min, the reaction pressure is 4.0~10.0MPa, and the reaction temperature is 170~250℃. In this method, the obtained styrene- and indene-rich fractions are directly polymerized under the action of boron trifluoride catalyst. The resulting resin has a larger molecular weight, which can reach more than 5000. The resin has poor compatibility with substrates such as EVA, SIS, and SBS. Summary of the Invention

[0005] To address the aforementioned shortcomings, the present invention aims to obtain a lower molecular weight resin by increasing the content of dimethylcyclopentadiene and utilizing the steric hindrance of dimethylcyclopentadiene under the action of a new catalyst. Furthermore, due to the cyclic structure of dimethylcyclopentadiene, the softening point is also relatively high, ultimately resulting in a low molecular weight C9 petroleum resin with a high softening point. This significantly improves the problem of poor compatibility between the resin and substrates such as EVA, SIS, and SBS.

[0006] A second objective of this invention is to provide a method for preparing C9 petroleum resin.

[0007] Therefore, the first technical solution proposed by this invention is as follows:

[0008] A method for preparing a low molecular weight C9 petroleum resin with a high softening point, comprising the following steps:

[0009] S1. Weigh 600-1100 parts by weight of C9 fraction, 100-500 parts by weight of dimethylcyclopentadiene, 3-8 parts by weight of catalyst, and 300-600 parts by weight of diluent.

[0010] S2. Pour the C9 fraction, dimethylcyclopentadiene, and diluent weighed in S1 into the reaction vessel, and introduce inert gas for protection, maintaining the pressure inside the vessel at 0.01-0.02 MPa, and stir to mix;

[0011] S3. Add 3-8 parts by weight of catalyst dropwise to the reaction vessel of S2, gradually raise the temperature to 30-50℃, and raise the pressure to 0.1-0.5MPa. After the catalyst is completely added, react for 2-4 hours to obtain the polymerization liquid.

[0012] S4. Transfer the polymerization solution obtained in S3 to the neutralization vessel and add a terminator until the pH value of the polymerization solution reaches 8-10 to terminate the polymerization reaction.

[0013] S5. In the neutralization vessel of S4, add 12-24 parts by weight of acidic clay for decolorization, stir evenly, keep the temperature at 80℃ for 2 hours, and obtain a polymerization liquid with a pH value of 7 by pressure filtration.

[0014] S6. The polymer solution after pressure filtration is subjected to reduced pressure and distillation to remove solvent and oligomers, thereby obtaining C9 petroleum resin with low molecular weight and high softening point.

[0015] Furthermore, in the above-mentioned method for preparing low molecular weight, high softening point C9 petroleum resin, the C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained at the top of the column, and methylcyclopentadiene is obtained from the side stream. The heavy fraction is collected at 120-190℃ from the bottom of the column.

[0016] Furthermore, in the above-mentioned method for preparing low molecular weight, high softening point C9 petroleum resin, the C9 fraction mainly consists of: methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%, and the mass ratio of methylstyrene, indene, and dimethylcyclopentadiene is 30-60∶5-18∶10-50.

[0017] Furthermore, in the above-mentioned method for preparing low molecular weight, high softening point C9 petroleum resin, the diluent is one of inert C9 raffinate oil, toluene, xylene, and cyclohexane.

[0018] Furthermore, in the above-mentioned method for preparing low molecular weight, high softening point C9 petroleum resin, the catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid.

[0019] Furthermore, in the above-mentioned method for preparing low molecular weight, high softening point C9 petroleum resin, the method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 60-70°C for 1-3 hours to obtain dimethylcyclopentadiene.

[0020] Furthermore, in the above-mentioned method for preparing low molecular weight C9 petroleum resin with a high softening point, the heating time in step S3 is 0.1h-0.3h, the pressurization time is 0.1h-0.3h, and the catalyst dropping time is 0.5h-1h.

[0021] Furthermore, in the above-mentioned method for preparing low molecular weight C9 petroleum resin with a high softening point, the vacuum distillation conditions described in S3 are ultimate vacuum and 220℃-230℃.

[0022] Furthermore, in the above-mentioned method for preparing low molecular weight, high softening point C9 petroleum resin, the inert gas in S2 is nitrogen, helium, or argon; the terminating agent in S4 is one or more of sodium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, sodium bicarbonate, and sodium carbonate.

[0023] The second technical solution provided by the present invention is a low molecular weight C9 petroleum resin with a high softening point, which is prepared by the method described in the first technical solution.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention uses a mixture of molybdenum pentachloride and chlorosulfonic acid as a catalyst. Compared with the traditional boron trifluoride catalyst, molybdenum pentachloride has relatively weaker activity and will shorten the molecular chain in terms of molecular chain growth. The addition of the superacid chlorosulfonic acid plays a chain termination role to a certain extent. Together, they effectively control the chain growth and molecular weight distribution of the resin, resulting in a resin with a lower molecular weight.

[0026] 2. The technical solution provided by the present invention controls the content of dicyclopentadiene component and increases the content of dimethylcyclopentadiene component to obtain C9 petroleum resin with low molecular weight and high softening point. This effectively solves the problem that traditional resins contain a large number of conjugated double bonds due to the presence of dicyclopentadiene, resulting in petroleum resins with more residual double bonds, severe resin cross-linking, and poor resin stability.

[0027] 3. The technical solution provided by this invention increases the content of dimethylcyclopentadiene. Since dimethylcyclopentadiene has two methyl groups on its ring, it effectively increases steric hindrance, causing the polymerization process to automatically terminate after a certain point and making it less prone to cross-linking. In addition, the two rings of dimethylcyclopentadiene in the resin structure allow for a higher softening point resin with a smaller molecular weight. The final synthesized C9 petroleum resin has the characteristics of light color, low molecular weight, and high softening point. It has good compatibility with other synthetic resins and various rubbers and can be widely used in hot melt adhesives, adhesives, inks, road marking paints, paints, etc. Detailed Implementation

[0028] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0029] Example 1

[0030] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0031] Step 1: Weigh 1080g of C9 fraction, 120g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain a pressure of 0.01-0.02MPa inside the vessel. Stir and mix.

[0032] The second step is to add the catalyst to the reactor from the first step using a metered dripping method with a dripping time of 0.5 hours to initiate the catalytic reaction of the mixture. The temperature in the reactor is gradually increased to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, the pressure is increased to 0.2 MPa and the mixture is stirred at a constant temperature of 50°C for 4 hours.

[0033] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add sodium hydroxide, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0034] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0035] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0036] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0037] The C9 fraction is cracked at 290°C under xylene protection. The cracking products are condensed to 90°C and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120°C as the heavy fraction. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0038] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 60°C for 3 hours to obtain dimethylcyclopentadiene.

[0039] The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid, and the diluent is xylene.

[0040] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0041]

[0042]

[0043] Example 2

[0044] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0045] Step 1: Weigh 960g of C9 fraction, 240g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain a pressure of 0.01-0.02MPa inside the vessel. Stir and mix.

[0046] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0047] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add calcium hydroxide, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0048] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0049] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0050] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0051] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0052] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 65°C for 2 hours to obtain dimethylcyclopentadiene.

[0053] The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid, and the diluent is xylene.

[0054] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0055] Methylstyrene 36.7 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 20

[0056] Example 3

[0057] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0058] Step 1: Weigh 840g of C9 fraction, 360g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain the pressure inside the vessel at 0.01-0.02MPa. Stir and mix the mixture.

[0059] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0060] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add potassium hydroxide, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0061] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0062] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0063] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0064] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0065] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 68°C for 3 hours to obtain dimethylcyclopentadiene.

[0066] The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid, and the diluent is xylene.

[0067] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0068] Methylstyrene 29.7 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 30

[0069] Example 4

[0070] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0071] Step 1: Weigh 720g of C9 fraction, 480g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen to maintain a pressure of 0.01-0.02MPa inside the vessel, while stirring and mixing.

[0072] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0073] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add sodium carbonate, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0074] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0075] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0076] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0077] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0078] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 70°C for 1 hour to obtain dimethylcyclopentadiene.

[0079] The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid, and the diluent is xylene.

[0080] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0081] Methylstyrene 17.7 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 40

[0082] Comparative Example 1

[0083] The C9 petroleum resin with a low molecular weight and a high softening point provided in this comparative example is prepared by the following steps:

[0084] Step 1: Weigh 1176g of C9 fraction, 24g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain the pressure inside the vessel at 0.01-0.02MPa. Stir and mix the mixture.

[0085] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0086] The third step is to transfer the polymerization liquid from the reactor in the second step to the neutralization vessel, add solid alkali, and terminate the polymerization reaction until the pH value of the polymerization liquid is greater than 7.

[0087] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0088] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0089] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0090] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0091] The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid, and the diluent is xylene.

[0092] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0093] Methylstyrene 59 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 2

[0094] Comparative Example 2

[0095] The C9 petroleum resin with a low molecular weight and a high softening point provided in this comparative example is prepared by the following steps:

[0096] Step 1: Weigh 1080g of C9 fraction, 120g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain the pressure inside the vessel at 0.01-0.02MPa. Stir and mix the mixture.

[0097] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0098] The third step is to transfer the polymerization liquid from the reactor in the second step to the neutralization vessel, add solid alkali, and terminate the polymerization reaction until the pH value of the polymerization liquid is greater than 7.

[0099] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0100] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0101] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0102] The C9 fraction is obtained by depolymerizing dicyclopentadiene and methyldicyclopentadiene in the ethylene cracking C9 fraction under xylene protection at 290-360℃. A cyclopentadiene fraction is obtained from the top of the column, a methyldicyclopentadiene fraction from the side stream, and the bottom product is mixed with an ethylene cracking C9 fraction containing 30% dicyclopentadiene. The fraction is collected at 120-190℃ by rectification. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the dicyclopentadiene content reaches 21.6 wt%.

[0103] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 65°C for 2 hours. The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid, and the diluent is xylene.

[0104] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0105] Methylstyrene 28.7 Dicyclopentadiene 21.6 Indene content 10 dimethylcyclopentadiene 10

[0106] Comparative Example 3

[0107] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0108] Step 1: Weigh 1080g of C9 fraction, 120g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen to maintain a pressure of 0.01-0.02MPa inside the vessel. Increase the pressure to 0.2MPa and stir to mix.

[0109] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, stir at a constant temperature of 50°C for 4 hours.

[0110] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add sodium hydroxide, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0111] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0112] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0113] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0114] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0115] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 65°C for 2 hours. The catalyst is molybdenum pentachloride, and the diluent is xylene.

[0116] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0117] Methylstyrene 48.7 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 10

[0118] Comparative Example 4

[0119] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0120] Step 1: Weigh 1080g of C9 fraction, 120g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain a pressure of 0.01-0.02MPa inside the vessel. Stir and mix.

[0121] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0122] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add sodium hydroxide, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0123] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0124] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0125] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0126] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0127] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 65°C for 2 hours. The catalyst is chlorosulfonic acid, and the diluent is xylene.

[0128] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0129] Methylstyrene 48.7 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 10

[0130] Comparative Example 5

[0131] This embodiment provides a low molecular weight, high softening point C9 petroleum resin, which is prepared through the following steps:

[0132] Step 1: Weigh 1080g of C9 fraction, 120g of dimethylcyclopentadiene, 6g of catalyst, and 600g of diluent. Pour the weighed C9 fraction, dimethylcyclopentadiene, and diluent into a reaction vessel, and purge with nitrogen gas to maintain a pressure of 0.01-0.02MPa inside the vessel. Stir and mix.

[0133] The second step is to add the catalyst to the reactor from the first step using a metered dripping method, with a dripping time of 0.5 hours, so that the mixture can start the catalytic reaction. Gradually increase the temperature in the reactor to 50°C to accelerate the catalytic reaction time and the polymerization depth of the mixture. After the catalyst is added, increase the pressure to 0.2 MPa and stir at 50°C for 4 hours.

[0134] The third step is to transfer the polymerization solution from the reactor in the second step to the neutralization vessel, add sodium hydroxide, and terminate the polymerization reaction until the pH value of the polymerization solution is greater than 7.

[0135] Step 4: Add 2wt% white clay to the neutralization vessel from step 3 for decolorization, stir evenly, heat to 80℃ and maintain the temperature for 2 hours, then filter under pressure to obtain the reaction solution.

[0136] Filtration conditions: The filter press is equipped with high-speed filter paper and pressurized with nitrogen at 0.1-0.5 MPa to separate the polymerization liquid from the bleaching clay residue.

[0137] Step 5: After the polymer solution is filtered, a vacuum oil pump is used to evacuate it, and the vacuum degree is controlled at 100-300 Pa for decompression. The solution is then distilled at a temperature of 220-230℃ to remove the solvent and oligomers, thus obtaining C9 petroleum resin with low molecular weight and high softening point.

[0138] The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained from the top of the column, and methylcyclopentadiene is obtained from the side stream. The bottom product is collected at 120-190℃ as the heavy component. The main components of the C9 fraction are a mixture of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%.

[0139] The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 65°C for 2 hours. The catalyst is boron trifluoride, and the diluent is xylene.

[0140] The gas phase composition of the C9 fraction mixed with dimethylcyclopentadiene is as follows (not listed, but inert aromatics):

[0141] Methylstyrene 48.7 Dicyclopentadiene 1.6 Indene content 10 dimethylcyclopentadiene 10

[0142] The testing methods for the various technical indicators of this invention are as follows:

[0143] 1. Determination of softening point: The softening point shall be determined according to the ring and ball method of the asphalt softening point determination method (National Standard GB / T 4507-1999).

[0144] 2. Color determination: The color was determined according to the Gardner colorimetric method (GB / T 222295-2008) for epoxy resin color determination.

[0145] 3. Compatibility Testing: Petroleum resin is primarily tested by blending it with EVA and 80# microcrystalline wax in a specific ratio, heating the mixture in a test tube until clear, and then stirring and cooling it until a misty state appears. The temperature at which the mixture reaches this point is taken as the wax mist point. The higher the wax mist point, the worse the compatibility of the mixture. Therefore, this invention uses 50 wt% low molecular weight, high softening point C9 petroleum resin, 30 wt% EVA, and 20 wt% 80# microcrystalline wax, blended at 180-200℃ for 0.5 h, and then tests the wax mist point of the mixture. The compatibility of the modified petroleum resin with the corresponding blend is evaluated by comparing the change in wax mist point value with that of general C9 petroleum resin.

[0146] 4. Thermal stability test: Weigh 5g of resin into a small glass bottle, put them together in a forced-air drying oven and heat to 180℃, keep at a constant temperature for 4 hours, and measure the difference in color before and after to compare thermal stability.

[0147] 5. Molecular weight distribution determination: The molecular weight distribution was determined by Malvern GPC analysis. The mobile phase was tetrahydrofuran, the flow rate was 1 ml / min, and the injection volume was 100 μl.

[0148] The performance test results of petroleum resins in Examples 1-4 and Comparative Examples 1-5 are shown in Table 1:

[0149] Table 1

[0150]

[0151]

[0152] As can be seen from the test results in Table 1, the low molecular weight, high softening point C9 petroleum resin prepared using the technical solution of this invention has a higher softening point and lower molecular weight compared to conventional C9 petroleum resin. It also exhibits less color change at high temperatures and good thermal stability. Furthermore, the compatibility of the low molecular weight, high softening point C9 petroleum resin with EVA is significantly improved, and the wax mist point is lower, enabling the C9 petroleum resin to be stably used in hot melt adhesives or adhesives, thus demonstrating greater adaptability in downstream application formulations. Therefore, this invention, by controlling the molecular weight of C9 petroleum resin, solves the problems of its deep color, poor thermal stability, and poor compatibility, and has good industrial application value.

Claims

1. A method for preparing a low molecular weight C9 petroleum resin with a high softening point, characterized in that, It is obtained through the following steps: S1. Weigh 600-1100 parts by weight of C9 fraction, 100-500 parts by weight of dimethylcyclopentadiene, 3-8 parts by weight of catalyst, and 300-600 parts by weight of diluent. S2. Pour the C9 fraction, dimethylcyclopentadiene, and diluent weighed in S1 into the reaction vessel, and introduce inert gas for protection, maintain the pressure inside the vessel at 0.01-0.02 MPa, and stir to mix. S3. Add 3-8 parts by weight of catalyst dropwise to the reaction vessel of S2, gradually raise the temperature to 30-50℃, and raise the pressure to 0.1-0.5MPa. After the catalyst is completely added, react for 2-4 hours to obtain the polymerization liquid. S4. Transfer the polymerization solution obtained in S3 to the neutralization vessel and add a terminator until the pH value of the polymerization solution reaches 8-10 to terminate the polymerization reaction. S5. Add 12-24 parts by weight of acidic clay to the neutralization vessel of S4 for decolorization. After stirring evenly, keep the temperature at 75-85℃ for 1-3 hours. After pressure filtration, obtain a polymerization solution with a pH value of 7. S6. The polymer solution after pressure filtration is subjected to reduced pressure and distillation to remove solvent and oligomers, in order to obtain low molecular weight C9 petroleum resin with high softening point. The C9 fraction mainly consists of methylstyrene, dicyclopentadiene, and indene; and the content of dicyclopentadiene is less than 2 wt%, and the mass ratio of methylstyrene, indene, and dimethylcyclopentadiene is 30-60: 5-18: 10-50. The catalyst is a mixture of molybdenum pentachloride and chlorosulfonic acid.

2. The method for preparing low molecular weight, high softening point C9 petroleum resin according to claim 1, characterized in that, The C9 fraction is cracked at 290-360℃ under xylene protection. The cracking products are condensed to 80-90℃ and then separated in a distillation column. Dicyclopentadiene is obtained at the top of the column, and methylcyclopentadiene is obtained from the side stream. The heavy fraction is collected at 120-190℃ from the bottom of the column.

3. The method for preparing low molecular weight, high softening point C9 petroleum resin according to claim 1, characterized in that, The diluent is one of inert C9 raffinate oil, toluene, xylene, and cyclohexane.

4. The method for preparing low molecular weight, high softening point C9 petroleum resin according to claim 1, characterized in that, The method for preparing dimethylcyclopentadiene is to polymerize methylcyclopentadiene at 60-70℃ for 1-3 hours to obtain dimethylcyclopentadiene.

5. The method for preparing low molecular weight, high softening point C9 petroleum resin according to claim 1, characterized in that, The heating time in S3 is 0.1h-0.3h, the pressurization time is 0.1h-0.3h, and the catalyst dropping time is 0.5h-1h.

6. The method for preparing low molecular weight, high softening point C9 petroleum resin according to claim 1, characterized in that, The inert gas mentioned in S2 is nitrogen, helium, or argon; the terminating agent mentioned in S4 is one or more of sodium hydroxide, calcium hydroxide, potassium hydroxide, barium hydroxide, sodium bicarbonate, and sodium carbonate.

7. A low molecular weight C9 petroleum resin with a high softening point, characterized in that, Prepared using the method described in any one of claims 1-6.

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