A terpene polymerization catalyst resistant to poisoning by papermaking black liquor impurities, and a preparation method and application thereof

Abstract

The application discloses a terpene polymerization catalyst resistant to papermaking black liquor impurity poisoning and a preparation method and application thereof, and belongs to the field of forest product chemical industry and catalysis technology. The catalyst comprises: a porous carbon carrier prepared from recovered lignin in papermaking black liquor by adjusting the pH of the lignin to 5.5-6.5 through acid, impregnating and activating the lignin in a phosphoric acid solution, and carbonizing the lignin at 350-450 DEG C for 4-6 h; an active component loaded on the porous carbon carrier; and an anti-poisoning modification layer coated on the surface of the catalyst, wherein the anti-poisoning modification layer is APTES. The application further provides a preparation method of the catalyst, a method for preparing terpene resin by using the catalyst, and application of the terpene resin in pressure-sensitive adhesive. The catalyst has excellent anti-poisoning capacity for lignin sulfonate and acetic acid complex impurities in recovered pinene in papermaking black liquor, and can stably polymerize in a wide range of mass ratios of alpha-pinene to beta-pinene of 60:40 to 90:10.

Description

Technical Field

[0001] This invention relates to the fields of forestry chemical industry and catalysis technology, specifically to an anti-poisoning catalyst for recovering pinene from black liquor of papermaking wastewater to prepare terpene resin, particularly suitable for α-pinene / β-pinene cationic polymerization reactions containing lignin sulfonate and acetic acid impurities; the catalyst is adaptable to a wide pinene ratio range of 60:40 to 90:10, and the resulting terpene resin exhibits excellent tackifying properties and substrate compatibility in SIS-based pressure-sensitive adhesives, EVA-based hot melt adhesives, and high-performance tire treads. Background Technology

[0002] The information disclosed in this background section is intended only to enhance some understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art.

[0003] Black liquor in the papermaking industry can be divided into sulfite black liquor and alkaline black liquor according to different pulping processes. Sulfite black liquor contains 10-20% impurities (65% organic matter and 35% inorganic matter). Besides lignin sulfonates, the organic matter also contains lower fatty acids such as acetic acid and formic acid. The crude turpentine oil recovered from this type of black liquor can be separated to obtain α-pinene and β-pinene monomers. However, even after preliminary purification, the recovered pinene monomers still retain small amounts of lignin sulfonates or acetic acid impurities. These residual lignin sulfonates and acetic acid impurities can severely poison the polymerization catalyst, and the pinene composition fluctuates greatly depending on the raw materials and pulping process (α-pinene 60%-90%, β-pinene 10%-40%). Current technology suffers from three core defects: (1) Severe poisoning by impurities: The carboxyl groups of organic acids form coordination bonds with the active sites of Lewis acid catalysts, and the sulfur element of lignin sulfonate poisons the active centers through electron transfer, leading to the conventional The activity of the catalyst decreases significantly under the action of complex impurities, making it difficult to maintain the degree of resin polymerization, and in severe cases, it may even be impossible to form an effective high molecular weight polymer. (2) Poor ratio adaptability: In the high α-pinene system (≥80%), the synergistic effect of impurities and low-activity monomers further significantly reduces the degree of polymerization, and the 180° peel strength of the resulting resin is usually lower than the industrial application standard; In the high β-pinene system (≥40%), although the polymerization rate is increased, impurities lead to a broad molecular weight distribution (PDI>3.0), and the holding power is greatly shortened, making it difficult to meet the basic requirements of the tape industry for holding power; (3) Insufficient application performance: commercial The resin prepared by the catalyst suffered a peel strength loss of over 50% after thermal aging at 80℃ for 72 hours, and had poor compatibility with the SIS substrate (phase separation temperature > 40℃), limiting its practical application scenarios.

[0004] On the other hand, alkaline black liquor contains abundant alkali lignin, which can serve as a carbon source for catalyst carriers, enabling the resource utilization of black liquor waste. This invention utilizes pinene containing impurities recovered from sulfite black liquor as a polymerization monomer and alkali lignin extracted from alkaline black liquor as a catalyst carrier, achieving multi-pathway resource utilization of papermaking black liquor.

[0005] Existing technologies (such as CN102188995B lignin-based support catalyst preparation and CN109942363A α-pinene hydrogenation catalyst anti-poisoning modification) have not solved the problems of complex impurity poisoning, wide ratio adaptation and application performance synergy in black liquor recovery of pinene. Developing anti-poisoning catalysts with adapted systems has become a key issue for the industry. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention aims to solve the problem of synergistic poisoning of acetate-lignin sulfonate complex impurities in pinene recovered from papermaking black liquor, achieve stable polymerization of a wide pinene ratio of 60:40 to 90:10, and improve the degree of polymerization, molecular weight uniformity, tackifying properties, aging resistance, and substrate compatibility of terpene resins in pressure-sensitive adhesives.

[0007] The technical solution adopted in this invention is as follows: In a first aspect, the present invention provides a terpene polymerization catalyst resistant to poisoning by impurities in papermaking black liquor, the catalyst comprising: The porous carbon support is prepared by recovering lignin from papermaking black liquor, adjusting the pH to 5.5-6.5 with acid, impregnating and activating with phosphoric acid solution, and carbonizing at 350-450℃ for 4-6 hours. Active components loaded on the porous carbon support ;as well as An anti-poisoning modification layer is coated on the surface of the catalyst, wherein the anti-poisoning modification layer is 3-aminopropyltriethoxysilane (APTES); the specific surface area of ​​the porous carbon support is ≥800 m² / g. 2 / g, pore volume ≥0.7cm 3 / g; the aforementioned The mass ratio of the porous carbon support to the porous carbon support is (2-4):10.

[0008] Preferably, the amount of APTES used is 10-20% of the mass of the porous carbon support.

[0009] A second aspect of the present invention provides a method for preparing the catalyst, comprising the following steps: (1) Lignin pretreatment: The black liquor from papermaking is purified to obtain refined lignin; (2) Carrier preparation: The refined lignin is activated with phosphoric acid solution and then carbonized under inert gas protection to prepare a porous carbon carrier; (3) Active loading: The porous carbon support is combined with... The mixture is mixed in an organic solvent, subjected to reflux loading reaction, separated, and then dried. (4) Anti-toxic modification: APTES is added to the product obtained in step (3) for reaction, and the catalyst is obtained after drying.

[0010] Preferably, the purification process in step (1) includes: adjusting the pH of the papermaking black liquor to 5.5-6.5 with acid, adding an alcohol solvent for precipitation, and drying after solid-liquid separation.

[0011] Preferably, the activation treatment in step (2) includes: immersing in a 4-6% phosphoric acid solution at 50-70°C for 100-140 min; the carbonization temperature is 350-450°C and the carbonization time is 4-6 h.

[0012] Preferably, the step (3) described The mass ratio of the reflux loading reaction to the porous carbon support is (2-4):10, and the temperature of the reflux loading reaction is 70-90℃, and the time is 3-5 h.

[0013] Preferably, the amount of APTES added in step (4) is 10-20% of the mass of the porous carbon support, the reaction temperature is 40-60℃, and the time is 1-3 h.

[0014] A third aspect of the present invention provides a method for preparing terpene resin using the catalyst, comprising the following steps: Under nitrogen protection at -10-0℃, a mixture of α-pinene and β-pinene monomers was added dropwise to a reaction system containing an organic solvent and the catalyst to carry out a polymerization reaction. After the reaction was completed, a terminator was added, the catalyst was separated and recovered, and the reaction solution was post-treated to obtain terpene resin.

[0015] Preferably, the mass ratio of α-pinene to β-pinene is 60:40 to 90:10; the purity of the mixed monomers is ≥85%, wherein the lignin sulfonate content is ≤0.5% and the acetic acid content is ≤0.5%.

[0016] Preferably, the mass ratio of the monomer to the catalyst is 100:(2-4); the polymerization reaction time is 4-8 h.

[0017] Preferably, the terminating agent is an alcohol solvent; the post-treatment includes vacuum distillation to remove the solvent and unreacted monomers.

[0018] Preferably, the softening point of the obtained terpene resin is ≥90℃ and the molecular weight distribution index (PDI) is ≤1.9; the catalyst can be recycled more than 5 times, and the catalyst deactivation rate is ≤30% when it is used for the 5th time.

[0019] In a fourth aspect, the present invention provides the application of the terpene resin prepared by the method in a pressure-sensitive adhesive, wherein the pressure-sensitive adhesive is a SIS-based pressure-sensitive adhesive, and the amount of terpene resin added is 25-30% of the total mass of the pressure-sensitive adhesive; the pressure-sensitive adhesive has a 180° peel strength ≥ 2.8 N / 25 mm, a holding power ≥ 1500 min, and a peel strength loss rate ≤ 18% after heat aging at 80°C for 72 h.

[0020] The preparation method of the pressure-sensitive adhesive includes: mixing terpene resin at a ratio of 25-30% of the total mass of adhesive with SIS elastomer (40-45%), softener (15-20%), and antioxidant (0.5-1%), and melting and stirring at 150-160℃ for 20-40 minutes to obtain the pressure-sensitive adhesive.

[0021] Compared with the related technologies known to the inventors, one of the technical solutions of the present invention has the following beneficial effects: (1) Excellent resistance to complex poisoning: The APTES modified layer blocks the binding of lignin sulfonate to the active site through the acid-base interaction between amino and acetic acid carboxyl groups and steric hindrance. In the coexistence system of 0.3% acetic acid + 0.3% lignin sulfonate, the catalyst deactivation rate is reduced to below 18% (the deactivation rate of the unmodified catalyst is >75%).

[0022] (2) Stable compatibility with a wide range of ratios: PDI ≤ 1.9 and softening point ≥ 90 °C in the range of α-pinene:β-pinene = 60:40 to 90:10. This solves the problem of ratio sensitivity of traditional catalysts.

[0023] (3) Excellent tackifying properties: After the resin is added to the SIS pressure-sensitive adhesive, the 180° peel strength reaches 2.8-4.2 N / 25mm (ASTM D1002 standard), the holding power is ≥1500 min (GB / T 4851 standard), and the strength loss rate after 72h of heat aging at 80℃ is ≤18%.

[0024] (4) Excellent compatibility with substrate: As can be seen from the pressure-sensitive adhesive performance data of Examples 2-8, after the resin of the present invention is blended with the SIS substrate, it achieves high peel strength (≥2.8 N / 25mm) and high holding power (≥1500 min) without any application defects caused by phase separation, indicating that it has good compatibility with the SIS substrate.

[0025] (5) High environmental protection and economic efficiency: The catalyst carrier is derived from black liquor waste and can be recycled more than 5 times (the deactivation rate is still <30% after the 5th time), realizing resource utilization and having good environmental protection and economic efficiency. Attached Figure Description

[0026] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0027] Figure 1 These are scanning electron microscope (SEM) images of the porous carbon support obtained after carrier pretreatment in Embodiment 1 of the present invention.

[0028] Figure 2 The porous carbon support and load obtained after carrier pretreatment according to the present invention A comparison of the infrared spectra of the composite material and the final catalyst modified with APTES.

[0029] Figure 3 This is an electron microscope image of the catalyst prepared in Example 1 of the present invention.

[0030] Figure 4 These are experimental photographs of the polymerization reaction of pinene recovered from actual black liquor in Example 9.

[0031] Figure 5 This is a comparison of the infrared spectra of the terpene resins obtained in Example 4 (simulated impurities) and Example 9 (actual black liquor). Detailed Implementation

[0032] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0034] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0035] Example 1: Preparation of a terpene polymerization catalyst resistant to poisoning by impurities in papermaking black liquor

[0036] (1) Carrier pretreatment: Take 400g of alkaline black liquor (solid content of about 15%, source of alkaline black liquor: papermaking alkaline pulping black liquor of Hunan Juntian Bio-based New Material Technology Co., Ltd.), adjust pH=6 with 4mol / L hydrochloric acid, add 1200mL of 95v / v% ethanol to precipitate, filter and dry at 80℃ to obtain 12.5g of lignin; soak the lignin in 125mL of 5v / v% phosphoric acid solution at 60℃ for 120min. A porous carbon support (specific surface area 862 m² / g, pore volume 0.78 cm³ / g) was prepared by carbonization at 400℃ for 5 h under protective conditions. The microstructure of the support was observed by scanning electron microscopy as follows: Figure 1 As shown.

[0037] (2) Active loading and modification: 20g of porous carbon support was mixed with 6g of [amount missing], 130mL of toluene was added, and the mixture was refluxed at 80℃ for 4h. After filtration, the mixture was dried under vacuum at 100℃. 3g of APTES was added, and the mixture was reacted at 50℃ for 2h. The mixture was then dried at 120℃ to obtain 24.8g of the target catalyst. The catalyst was observed under an electron microscope, and its microstructure is shown in the figure below. Figure 3 As shown.

[0038] Infrared spectroscopy analysis was performed on the samples during the preparation process, and the resulting spectra are shown below. Figure 2 As shown. From Figure 2 It can be seen that after APTES modification, at 1102.29cm -1 The presence of characteristic Si-O-Si absorption peaks at various locations indicates that APTES was successfully grafted onto the catalyst surface.

[0039] Example 2: Polymerization of a single lignin sulfonate system (α:β=80:20)

[0040] In a 250 mL four-necked flask reactor equipped with a stirrer, 100 g of toluene (equal in mass to the monomer) was added, followed by 3 g of the catalyst prepared in Example 1. The refrigerator and stirrer were turned on, and under nitrogen protection and at a controlled temperature of -5°C, a mixture of 80 g of α-pinene and 20 g of β-pinene (containing 0.3 g of lignin sulfonate) was slowly added dropwise to the four-necked flask reactor using a peristaltic pump. The addition of monomers was timed over 2.5 hours from the start of the addition. After the addition was complete, the reaction was stirred for 6 hours at -5°C under nitrogen protection.

[0041] After the reaction is complete, 5 times the volume of ethanol is added to terminate the reaction. The catalyst is recovered by filtration (it can be recycled). The filtrate is distilled under reduced pressure and slowly heated to 180℃ / 0.08MPa to remove the solvent and unreacted monomers, yielding terpene resin.

[0042] The obtained terpene resin was tested and found to have a softening point of 109 °C, a molecular weight distribution index (PDI) of 1.6, and a catalyst deactivation rate of 12%.

[0043] Application and performance testing of pressure-sensitive adhesive: The obtained terpene resin was mixed with SIS elastomer (42%), softener (17%), and antioxidant (0.8%) at a ratio of 28% of the total adhesive mass. The mixture was melt-stirred at 150-160℃ for 30 minutes to obtain the pressure-sensitive adhesive. According to ASTM D1002 standard testing, the 180° peel strength was 3.9 N / 25 mm, the holding power was 1720 min, and after heat aging at 80℃ for 72 hours, the peel strength loss rate was 14%.

[0044] Example 3: Polymerization of a single acetic acid system (α:β=80:20)

[0045] In a 250 mL four-necked flask reactor equipped with a stirrer, 100 g of toluene (equal in mass to the monomer) was added, followed by 3 g of the catalyst prepared in Example 1. The refrigerator and stirrer were turned on, and under nitrogen protection and at a controlled temperature of -5°C, a mixture of 80 g of α-pinene and 20 g of β-pinene (containing 0.3 g of acetic acid) was slowly added dropwise to the four-necked flask reactor using a peristaltic pump. The addition of monomers was timed over 2.5 hours from the start of the addition. After the addition was complete, the reaction was stirred for 6 hours at -5°C under nitrogen protection.

[0046] After the reaction is complete, 5 times the volume of ethanol is added to terminate the reaction. The catalyst is recovered by filtration (it can be recycled). The filtrate is distilled under reduced pressure and slowly heated to 180℃ / 0.08MPa to remove the solvent and unreacted monomers, yielding terpene resin.

[0047] The obtained terpene resin was tested and found to have a softening point of 112 °C, a molecular weight distribution index (PDI) of 1.7, and a catalyst deactivation rate of 15%.

[0048] Application and performance testing of pressure-sensitive adhesive: The pressure-sensitive adhesive was prepared and tested according to the same method as in Example 2. The results are as follows: the 180° peel strength was 3.6 N / 25 mm, the holding power was 1650 min, and the peel strength loss rate was 16% after heat aging at 80°C for 72 h.

[0049] Example 4: Polymerization of a complex impurity system (α:β=80:20)

[0050] In a 250 mL four-necked flask reactor equipped with a stirrer, 100 g of toluene (equal in mass to the monomer) was added, followed by 3 g of the catalyst prepared in Example 1. The refrigerator and stirrer were turned on, and under nitrogen protection and at a controlled temperature of -5°C, a mixture of 80 g α-pinene and 20 g β-pinene (containing 0.3 g lignin sulfonate and 0.3 g acetic acid) was slowly added dropwise to the four-necked flask reactor using a peristaltic pump. The addition of monomers was timed over 2.5 hours from the start of the addition. After the addition was complete, the reaction was stirred for 6 hours at -5°C under nitrogen protection.

[0051] After the reaction is complete, 5 times the volume of ethanol is added to terminate the reaction. The catalyst is recovered by filtration (it can be recycled). The filtrate is distilled under reduced pressure and slowly heated to 180℃ / 0.08MPa to remove the solvent and unreacted monomers, yielding terpene resin.

[0052] The obtained terpene resin was tested and found to have a softening point of 105 °C, a molecular weight distribution index (PDI) of 1.8, and a catalyst deactivation rate of 17%. The infrared spectrum of the obtained resin is shown below. Figure 5 As shown.

[0053] Application and performance testing of pressure-sensitive adhesive: The pressure-sensitive adhesive was prepared and tested according to the same method as in Example 2. The results are as follows: the 180° peel strength is 3.2 N / 25 mm, the holding power is 1580 min, and the peel strength loss rate is 17% after heat aging at 80°C for 72 h.

[0054] Example 5: Catalyst recycling (α:β=80:20) The catalyst from Example 4 was recovered by filtration, washed three times with toluene, dried at 100°C, and reused directly without adding any fresh components. The reaction was repeated five times under the conditions of Example 4 (80g α-pinene, 20g β-pinene, containing 0.3g lignin sulfonate and 0.3g acetic acid, 3g catalyst, reaction at -5°C for 6h). The performance results of the terpene resin obtained after each cycle are shown in Table 1.

[0055] Table 1 Catalyst Recycling Performance

[0056] As shown in Table 1, with the increase of the number of cycles, the catalyst deactivation rate slightly increased, the molecular weight distribution of the resin slightly widened, and the peel strength and holding power showed a slight decreasing trend. However, after 5 cycles, the peel strength of the obtained resin can still reach 2.8 N / 25 mm, and the holding power is still maintained above 1500 min, indicating that the catalyst of the present invention has good recycling performance.

[0057] Example 6: Polymerization of high α-pinene ratio (α:β=90:10) In a 250 mL four-necked flask reactor equipped with a stirrer, 100 g of toluene (equal in mass to the monomer) was added, followed by 3 g of the catalyst prepared in Example 1. The refrigerator and stirrer were turned on, and under nitrogen protection and at a controlled temperature of -5°C, a mixture of 90 g α-pinene and 10 g β-pinene (containing 0.3 g lignin sulfonate and 0.3 g acetic acid) was slowly added dropwise to the four-necked flask reactor using a peristaltic pump. The addition of monomers was timed over 2.5 hours from the start of the addition. After the addition was complete, the reaction was stirred for 6 hours at -5°C under nitrogen protection.

[0058] After the reaction is complete, 5 times the volume of ethanol is added to terminate the reaction. The catalyst is recovered by filtration (it can be recycled). The filtrate is distilled under reduced pressure and slowly heated to 180℃ / 0.08MPa to remove the solvent and unreacted monomers, yielding terpene resin.

[0059] The obtained terpene resin was tested and found to have a softening point of 102℃, a molecular weight distribution index (PDI) of 1.8, and a catalyst deactivation rate of 16%.

[0060] Application and performance testing of pressure-sensitive adhesive: The pressure-sensitive adhesive was prepared and tested according to the same method as in Example 2. The results are as follows: the 180° peel strength is 2.8 N / 25 mm, the holding power is 1520 min, and the peel strength loss rate is 17% after heat aging at 80°C for 72 h.

[0061] Note: The high α-pinene system has slightly lower polymerization degree and peel strength due to its low monomer activity, but its molecular chain structure is more stable and its aging resistance is good.

[0062] Example 7: Polymerization of pinene with balanced ratio (α:β=70:30) In a 250 mL four-necked flask reactor equipped with a stirrer, 100 g of toluene (equal in mass to the monomer) was added, followed by 3 g of the catalyst prepared in Example 1. The refrigerator and stirrer were turned on, and the temperature was controlled to -5 °C. Under nitrogen protection, a mixture of 70 g of α-pinene and 30 g of β-pinene (containing 0.3 g of lignin sulfonate and 0.3 g of acetic acid) was slowly added dropwise to the reactor using a peristaltic pump over approximately 2.5 h. After the addition was complete, the reaction was continued with stirring for 6 h at -5 °C under nitrogen protection.

[0063] After the reaction was completed, 5 times the volume of ethanol was added to terminate the reaction, and the catalyst was recovered by filtration. The filtrate was then distilled under reduced pressure and slowly heated to 180℃ / 0.08MPa to remove the solvent and unreacted monomers, yielding terpene resin.

[0064] The obtained terpene resin was tested and found to have a softening point of 118℃, a molecular weight distribution index (PDI) of 1.7, and a catalyst deactivation rate of 14%.

[0065] Application and performance testing of pressure-sensitive adhesive: The pressure-sensitive adhesive was prepared and tested according to the same method as in Example 2. The results are as follows: the peel strength at 180° is 4.2 N / 25 mm, the holding power is 1850 min, and the peel strength loss rate after heat aging at 80°C for 72 h is 12%.

[0066] Example 8: Polymerization of high β-pinene ratio (α:β=60:40) In a 250 mL four-necked flask reactor equipped with a stirrer, 100 g of toluene (equal in mass to the monomer) was added, followed by 3 g of the catalyst prepared in Example 1. The refrigerator and stirrer were turned on, and the temperature was controlled to -5 °C. Under nitrogen protection, a mixture of 60 g of α-pinene and 40 g of β-pinene (containing 0.3 g of lignin sulfonate and 0.3 g of acetic acid) was slowly added dropwise to the reactor using a peristaltic pump over approximately 2.5 h. After the addition was complete, the reaction was continued for 6 h at -5 °C under nitrogen protection.

[0067] After the reaction was completed, 5 times the volume of ethanol was added to terminate the reaction, and the catalyst was recovered by filtration. The filtrate was then distilled under reduced pressure and slowly heated to 180℃ / 0.08MPa to remove the solvent and unreacted monomers, yielding terpene resin.

[0068] The obtained terpene resin was tested and found to have a softening point of 122℃, a molecular weight distribution index (PDI) of 1.8, and a catalyst deactivation rate of 15%.

[0069] Application and performance testing of pressure-sensitive adhesive: The pressure-sensitive adhesive was prepared and tested according to the same method as in Example 2. The results are as follows: the peel strength at 180° is 3.6 N / 25 mm, the holding power is 1680 min, and the peel strength loss rate after heat aging at 80°C for 72 h is 15%.

[0070] Note: The APTES modification layer effectively suppresses chain transfer reactions caused by impurities, avoiding the common problem of broadened molecular weight distribution in high β-pinene systems, and the PDI is stabilized at no more than 1.8.

[0071] Example 9: Polymerization reaction of pinene recovered from actual black liquor Crude turpentine oil recovered from black liquor in the sulfite papermaking process was distilled to obtain a mixed monomer of α-pinene and β-pinene (analyzed as α:β = 78:22, lignin sulfonate content 0.28%, acetic acid content 0.35%, and sulfur-containing compounds 0.05%). The polymerization was carried out according to the polymerization conditions of Example 4: 100g of the above mixed monomer was added dropwise to a reaction system containing 100g of toluene and 3g of the catalyst from Example 1 at -5°C under nitrogen protection, and the reaction was allowed to proceed for 6 hours. A photograph of the resin synthesis is shown below. Figure 4 As shown.

[0072] The obtained terpene resin was tested and found to have a softening point of 104℃, a PDI of 1.9, and a catalyst deactivation rate of 19%.

[0073] Pressure-sensitive adhesive application performance: 180° peel strength 3.1 N / 25mm, holding power 1550 min, peel strength loss rate after aging at 80℃ for 72h is 18%.

[0074] The results show that the catalyst of the present invention also has excellent resistance to complex impurities in the actual black liquor recovery of pinene, and the performance of the obtained resin is basically the same as that of the simulation system (Example 4).

[0075] The infrared spectrum of the obtained resin is as follows Figure 5 As shown, the positions and relative intensities of the characteristic absorption peaks of the two systems are basically the same, indicating that the resin obtained from the actual black liquor recovery of pinene has a similar chemical structure to the simulated system.

[0076] Comparative Experiment 1: Unmodified catalyst (α:β=80:20) The catalyst was prepared using the same method as in Example 1, but the APTES modification in step (2) was omitted, i.e., only the catalyst was prepared. / Porous carbon-supported catalyst. Repeat the steps of Example 4 to obtain terpene resin.

[0077] The obtained terpene resin was tested and found to have a softening point of 55℃, a PDI of 3.1, and a catalyst deactivation rate of 76%. Application performance (with 28% SIS pressure-sensitive adhesive added): 180° peel strength was 1.8 N / 25 mm, holding power was 650 min, and the peel strength loss rate after aging at 80℃ for 72 h was 52%.

[0078] Comparative Experiment 2: Commercial Catalyst (α:β=80:20) Commercially available analytical grade The catalyst was used, and the polymerization reaction was repeated following the steps of Example 4. After the reaction, the resulting resin was a viscous liquid at room temperature (extremely low degree of polymerization). Testing showed a PDI of 3.5, and the catalyst deactivation rate was over 90%. Application performance (with 28% SIS pressure-sensitive adhesive added): 180° peel strength was 1.4 N / 25 mm, holding power was 510 min, and the peel strength loss rate after aging at 80°C for 72 h was 57%.

[0079] Comparing the data from comparative experiments 1-2 with those from examples 2-8, we can see that: Under the same impurity system (0.3% lignin sulfonate + 0.3% acetic acid) and the same monomer ratio (80:20): The catalyst of this invention (Example 4) has a deactivation rate of only 17%, a PDI of 1.8, a 180° peel strength of 3.2 N / 25 mm, a holding power of 1580 min, and an aging loss rate of 17% at 80°C. The unmodified catalyst (comparative experiment 1) had a deactivation rate as high as 76%, a PDI of 3.1, a 180° peel strength of only 1.8 N / 25 mm, a holding power of 650 min, and an aging loss rate of 52%. The commercial AlCl3 catalyst (comparative experiment 2) had a deactivation rate of over 90%, a PDI of 3.5, a 180° peel strength of only 1.4 N / 25 mm, a holding power of 510 min, and an aging loss rate of 57%.

[0080] Within the range of pinene ratios (90:10 to 60:40): The resins obtained from the catalysts of this invention (Examples 6-8) all have a PDI ≤ 1.9, a softening point ≥ 102℃, a peel strength ≥ 2.8 N / 25mm, and a holding power ≥ 1500 min. In contrast, the catalysts (comparative experiments 1-2) showed PDI > 3.0, peel strength ≤ 1.8 N / 25 mm, holding power ≤ 650 min, and aging loss rate of over 52% in a single ratio (80:20).

[0081] The above comparative results show that the catalyst of the present invention has excellent resistance to the complex impurities (lignin sulfonate and acetic acid) in pinene recovered from black liquor, and can stably catalyze the polymerization reaction under different pinene ratios. The overall performance of the resulting resin is significantly better than that of the prior art.

[0082] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A terpene polymerization catalyst resistant to poisoning by papermaking black liquor impurities, characterized in that, The catalyst includes: The porous carbon support is prepared by recovering lignin from papermaking black liquor, adjusting the pH to 5.5-6.5 with acid, impregnating and activating with phosphoric acid solution, and carbonizing at 350-450℃ for 4-6 hours. Active components loaded on the porous carbon support ;as well as An anti-poisoning modification layer is coated on the surface of the catalyst, wherein the anti-poisoning modification layer is 3-aminopropyltriethoxysilane (APTES). The porous carbon support has a specific surface area ≥ 800 m². 2 / g, pore volume ≥0.7 cm³ 3 / g; the aforementioned The mass ratio of the porous carbon support to the porous carbon support is (2-4):

10.

2. The catalyst according to claim 1, characterized in that, The amount of APTES used is 10-20% of the mass of the porous carbon support.

3. A method for preparing the catalyst according to claim 1 or 2, characterized in that, Includes the following steps: (1) Lignin pretreatment: The black liquor from papermaking is purified to obtain refined lignin; (2) Preparation of carrier: The refined lignin is activated with phosphoric acid solution and then carbonized under inert gas protection to prepare a porous carbon carrier; (3) Active loading: The porous carbon support is combined with... The mixture is mixed in an organic solvent, subjected to reflux loading reaction, separated, and then dried. (4) Anti-toxic modification: APTES is added to the product obtained in step (3) for reaction, and the catalyst is obtained after drying.

4. The method according to claim 3, characterized in that, The purification process described in step (1) includes: adjusting the pH of the papermaking black liquor to 5.5-6.5 with acid, adding an alcohol solvent for precipitation, and drying after solid-liquid separation; The activation treatment in step (2) includes: immersing in a 4-6% phosphoric acid solution at 50-70℃ for 100-140 min; the carbonization temperature is 350-450℃ and the carbonization time is 4-6 h.

5. The method according to claim 3, characterized in that, The steps described in step (3) The mass ratio of the reflux loading reaction to the porous carbon support is (2-4):10, and the temperature of the reflux loading reaction is 70-90℃, and the time is 3-5 h. In step (4), the amount of APTES added is 10-20% of the mass of the porous carbon support, the reaction temperature is 40-60℃, and the time is 1-3 h.

6. A method for preparing terpene resin using the catalyst according to claim 1 or 2, characterized in that, Includes the following steps: Under nitrogen protection at -10-0℃, a mixture of α-pinene and β-pinene monomers was added dropwise to a reaction system containing an organic solvent and the catalyst to carry out a polymerization reaction. After the reaction is complete, a terminator is added, the catalyst is separated and recovered, and the reaction solution is post-treated to obtain terpene resin.

7. The method according to claim 6, characterized in that, The mass ratio of α-pinene to β-pinene is 60:40 to 90:10; The mixed monomers contain lignin sulfonate content ≤0.5% and acetic acid content ≤0.5%; The mass ratio of the monomer to the catalyst is 100:(2-4); The polymerization reaction takes 4-8 hours.

8. The method according to claim 6, characterized in that, The terminating agent is an alcohol solvent; The post-processing includes vacuum distillation to remove solvent and unreacted monomers.

9. The method according to claim 6, characterized in that, The resulting terpene resin has a softening point ≥90℃ and a molecular weight distribution index (PDI) ≤1.

9. The catalyst can be recycled more than 5 times, and the catalyst deactivation rate is ≤30% when it is used for the 5th time.

10. The application of a terpene resin prepared by the method according to any one of claims 6-9 in pressure-sensitive adhesives, characterized in that, The pressure-sensitive adhesive is a SIS-based pressure-sensitive adhesive, wherein the amount of terpene resin added is 25-30% of the total mass of the pressure-sensitive adhesive; The pressure-sensitive adhesive has a 180° peel strength ≥ 2.8 N / 25 mm, a holding power ≥ 1500 min, and a peel strength loss rate ≤ 18% after heat aging at 80°C for 72 h.

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