A terpene resin with controllable molecular weight and preparation method thereof

Abstract

The present application relates to a terpene resin with controllable molecular weight and a preparation method thereof. A preparation method of a terpene resin with controllable molecular weight comprises: mixing β-pinene with ethylene glycol to obtain a mixture; mixing toluene and a catalyst at ‑5 to 5°C until uniform; dropping the mixture and keeping it warm at 5‑10°C for 1‑3h; removing the catalyst; desolventizing toluene and discharging the material, wherein the mass ratio of toluene to β-pinene is (1‑1.15): 1, the amount of the catalyst is 3.5‑5% of the mass of β-pinene, and the amount of ethylene glycol is 0.04‑0.07% of the mass of β-pinene. The present application can achieve precise control of the molecular weight of the terpene resin, prepare a terpene resin product with stable performance, and meet the high standard requirements of sanitary tape for viscosity, anti-aging and aviation electronic tape to enable it to perform accurately and stably in avionic electronic instruments, and broaden its application range in high-end applications such as medical, food, and aviation.

Description

Technical Field

[0001] The present invention relates to the field of terpene resins, and more specifically, to a terpene resin with controllable molecular weight and a preparation method thereof. Background Art

[0002] In the field of modern medical care and food safety, sanitary tape is a key auxiliary material, and its performance stability is directly related to the safety and reliability of the product. These applications place extremely high demands on the adhesiveness, anti-aging, and non-toxicity of the tape, and terpene resin, as an important component of the tape, is particularly critical in terms of its performance.

[0003] Sanitary tapes need to maintain long-term stable viscosity to ensure that they can reliably adhere to the skin or packaging materials in a variety of usage environments (such as different temperature and humidity conditions) to avoid falling off or leakage caused by insufficient or changing viscosity.

[0004] During long-term use, sanitary tapes will be affected by environmental factors such as light and oxidation, and are prone to aging and degradation. Tapes with strong anti-aging properties can resist the erosion of these factors, maintain stable performance, extend service life, reduce replacement frequency, and reduce costs.

[0005] In the medical field, the non-toxicity of the product is crucial. Stable performance can ensure that the tape does not release harmful substances during the manufacturing and use process, thus protecting human health and safety.

[0006] As data transmission in the aviation field, due to the precise control of product molecular weight, the electronic data transmitted in the avionics field is accurate and reliable.

[0007] Currently, terpene resins with a softening point of T-135℃ are mostly prepared using β-pinene in turpentine as raw material. However, β-pinene exhibits high cationic polymerization activity and fast reaction rate during the polymerization process, which makes it extremely difficult to control the polymerization process, resulting in a wide molecular weight distribution range of the final product, generally between 3600-5000.

[0008] Although the resin within this molecular weight range can meet the softening point requirement of T135, the terpene resins produced show great differences in performance due to the instability of the molecular weight. For example, a molecular weight that is too high may result in poor fluidity of the resin during processing and difficulty in evenly dispersing it in the substrate; while a molecular weight that is too low may reduce the cohesive strength and aging resistance of the resin, affecting the durability and safety of the product. This instability in performance limits the application of existing terpene resins in high-end applications such as sanitary tapes. Summary of the invention

[0009] In order to solve the above problems, the present application provides a terpene resin with controllable molecular weight and a preparation method thereof. The present application can achieve precise control of the molecular weight of the terpene resin, prepare a terpene resin product with stable performance, meet the high standard requirements of sanitary adhesive tape for adhesion, anti-aging and other properties, and broaden its application range in high-end applications such as medical and food.

[0010] In a first aspect, the present application provides a method for preparing a terpene resin with controllable molecular weight, using the following technical solution:

[0011] A method for preparing a terpene resin with controllable molecular weight comprises the following steps:

[0012] Step 1: mixing β-pinene and ethylene glycol until uniform to obtain a mixture;

[0013] Step 2: Mix toluene and the catalyst at -5 to 5°C until uniform;

[0014] Step 3: Add the mixture dropwise and keep warm at 5-10°C for 1-3h;

[0015] Step 4: Clean and remove the residual catalyst;

[0016] Step 5: desolventizing toluene at a distillation temperature of 230-240° C. and a vacuum degree of -0.085 to -0.099 MPa to obtain a terpene resin with controllable molecular weight;

[0017] The mass ratio of toluene to beta-pinene is (1-1.15):1, the amount of the catalyst used is 3.5-5% of the mass of the beta-pinene, and the amount of ethylene glycol used is 0.04-0.07% of the mass of the beta-pinene.

[0018] β-pinene is very easy to polymerize with catalysts, and the degree of polymerization is very high, so the reaction speed is fast. This also leads to the uncontrollable molecular weight of the generated terpene resin, and the molecular weight of terpene resins on the market ranges from 3,000 to 8,000. Most of the existing conventional ideas are how to improve the yield and purity of terpene resins, thereby improving product quality. However, there are few research and development of high-quality products with specific molecular weight and stability that can control molecular weight or meet the specific needs of downstream products.

[0019] By adopting the above technical solution, ethylene glycol is introduced to break the carbon-hydrogen bond on the outside of β-pinene, and the polymerization chain is controlled to be shorter, thereby effectively slowing down the polymerization reaction rate between β-pinene and the catalyst. The introduction of ethylene glycol not only makes the polymerization process smoother and more controllable, but also realizes the precise regulation of the molecular weight of the final product. Compared with the traditional method, it avoids the problem of uneven molecular weight distribution caused by too fast polymerization reaction, and ensures that the prepared terpene resin achieves a molecular weight within a specific range, which is crucial to improving product quality and consistency. In addition, the reaction process has good stability and repeatability.

[0020] Thanks to the inhibition effect of ethylene glycol, the terpene resin with controllable molecular weight obtained in this application has very stable performance and is particularly suitable for use in sanitary tapes with extremely high material performance requirements. The sanitary tape using the terpene resin with controllable molecular weight can show excellent initial adhesion, adhere quickly and firmly to the target surface, and improve the use effect of the tape. In addition to the initial adhesion, the sanitary tape can also be given excellent anti-aging properties. During long-term use, it can effectively resist the erosion of environmental factors such as light and oxidation, and maintain the stability of its physical and chemical properties. This feature is of great significance for extending the service life of the tape and improving the durability and reliability of the product.

[0021] Preferably, the mass ratio of toluene to β-pinene is 1.1:1, the amount of the catalyst is 3.5% of the mass of β-pinene, and the amount of ethylene glycol is 0.05% of the mass of β-pinene.

[0022] By adopting the above technical scheme, the dosage relationship of toluene, β-pinene, catalyst and ethylene glycol is further limited, so that ethylene glycol can more accurately slow down the polymerization reaction rate of β-pinene and catalyst, improve the quality of the generated terpene resin with controllable molecular weight, and further improve the viscosity and anti-aging effect of downstream products.

[0023] Preferably, in step 3, the mixture is added dropwise after the material in step 2 has no obvious temperature rise.

[0024] Preferably, in step 3, when the mixture is added dropwise to the material in step 2 for the first time, the temperature is controlled to rise by 3-5°C, and then the temperature is dropped to 0-2°C, and then the mixture is continued to be added dropwise, and the dropping temperature is controlled at 1-3°C.

[0025] Preferably, in step 3, after the mixture is added dropwise, the mixture is kept warm at 5-6° C. for 1-3 hours.

[0026] By adopting the above technical solution, the temperature of the dropwise added mixture is further limited, the progress of the reaction process is controlled in a physical way, and the reaction speed is assisted to be slowed down.

[0027] Preferably, the water content of the β-pinene is below 250 ppm.

[0028] Preferably, before the mixture is added dropwise, the β-pinene is stirred for 30 minutes and then allowed to stand for 30 minutes to separate the water; and then mixed with ethylene glycol until uniform to obtain a mixture.

[0029] By adopting the above technical solution, since ethylene glycol can be mixed with water in any proportion, if β-pinene contains water, the balance of the entire system will be disrupted, making it impossible for the subsequent terpene resin to grow and react in the expected direction, thereby failing to achieve precise control of the molecular weight.

[0030] Therefore, it is necessary to strictly control the water content of β-pinene to reduce the subsequent reaction and heat release caused by the presence of water, affect the reaction temperature, and thus speed up the reaction.

[0031] Preferably, the catalyst comprises at least one of anhydrous aluminum trichloride, anhydrous antimony trichloride and anhydrous titanium tetrachloride.

[0032] Preferably, in step 4, the residual catalyst is washed away by washing with water for multiple times.

[0033] In a second aspect, the present application provides a terpene resin with controllable molecular weight.

[0034] By adopting the above technical solution, the terpene resin with controllable molecular weight provided by this application significantly improves the overall performance of sanitary tape with its excellent stability. Its application in tape not only strengthens the initial adhesion of the tape, enabling it to adhere quickly and firmly to various surfaces; it also gives the tape excellent anti-aging properties, effectively resists long-term erosion by environmental factors such as light and oxidation, and maintains the stability of the tape's physical and chemical properties. It not only meets the strict requirements of sanitary tape for material properties, but also brings more durable and reliable product options to related industries, promoting technological progress and the expansion of applications.

[0035] In summary, this application has the following beneficial effects:

[0036] 1. The present application uses ethylene glycol to destroy the strength of the polymerization reaction, and controls the length of the polymerization chain while ensuring sufficient activity of the polymerization reaction, thereby controlling the fluctuation of the reaction temperature to be very small (1-2 degrees), and obtaining a terpene resin with a controllable molecular weight in the range of 4100-4200.

[0037] 2. The application introduces ethylene glycol, which successfully solves the problem of uncontrollable molecular weight caused by the overly fast polymerization reaction of β-pinene. The addition of ethylene glycol not only slows down the polymerization reaction speed, but also makes the polymerization process more stable, realizes the precise control of the molecular weight of the terpene resin, ensures that the prepared terpene resin with controllable molecular weight has a stable molecular weight within a specific range, and significantly improves the product quality.

[0038] 3. The terpene resin with controllable molecular weight prepared in this application has stable performance and is particularly suitable for the high-demand sanitary tape field. Its excellent initial adhesion ensures that the tape can quickly and firmly adhere to the target surface, improving the use effect. At the same time, the resin also gives the tape excellent anti-aging properties, which can effectively resist the erosion of environmental factors such as light and oxidation during long-term use, and maintain the stability of physical and chemical properties. This feature is of great significance for extending the service life of the tape and improving product durability and reliability, and provides a more high-quality and reliable solution for the sanitary tape industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a screenshot of the molecular weight test report of the terpene resin with controllable molecular weight in Example 1.

[0040] Figure 2 This is a screenshot of the molecular weight test report of the terpene resin with controllable molecular weight in Example 2.

[0041] Figure 3 This is a screenshot of the molecular weight test report of the terpene resin with controllable molecular weight in Example 3.

[0042] Figure 4 This is a screenshot of the molecular weight test report of the terpene resin with controllable molecular weight in Example 1.

[0043] Figure 5 This is a screenshot of the molecular weight test report of the terpene resin with controllable molecular weight of Example 2.

[0044] Figure 6 This is a test chart for the adhesion performance of sanitary tape. DETAILED DESCRIPTION

[0045] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0046] The raw materials used in the following examples and comparative examples are all commercially available products.

[0047] Example

[0048] Example 1

[0049] A method for preparing a terpene resin with controllable molecular weight comprises the following steps:

[0050] Step 1: Prepare raw materials according to the ratio of 2200kg of toluene (gas chromatography content 99.8%), 2000kg of β-pinene (gas chromatography content 98%), 1kg of ethylene glycol, and 80kg of catalyst (anhydrous aluminum chloride).

[0051] Step 2: Stir β-pinene for 30 minutes and then let it stand for 30 minutes to separate the water before reuse. Control the water content of β-pinene at 250ppm. Add 1kg of ethylene glycol into β-pinene and mix and stir evenly to obtain a mixture for use.

[0052] Step 3: Check whether the bottom valve of the polymerization kettle is in the closed state, check whether the bottom valves of the mixture and toluene metering tanks are closed, check whether the exhaust gas venting system is unobstructed, pump the mixture and 2200kg of toluene into the high-level tank metering tank respectively, let it stand for 30 minutes, and confirm again that the water is clean.

[0053] Step 4: Open the bottom valve of the toluene metering tank and pour the prepared anhydrous toluene directly into the polymerization reactor, making sure to pour it all in to avoid affecting the reaction.

[0054] Start the polymerization kettle and stir. (In summer) open the chilled water inlet valve and the cold brine pump. When the toluene in the kettle drops to 5°C, turn off the brine pump. The temperature will continue to drop (no cooling is required if the outdoor temperature is as low as -5°C).

[0055] When the kettle temperature drops to 0°C, 80 kg of catalyst is put into the reactor.

[0056] Step 5: When there is no obvious temperature rise in the reactor, the mixture can be added dropwise. The first addition is initiated by controlling the dropwise addition amount at 2000 L / h to raise the temperature to 3-5°C.

[0057] Turn on the brine pump again and continue to cool down to 1°C. Add the mixture again for reaction, and control the temperature between 1-3°C. Do not cool down until 0kg is left in the measuring tank, and keep it at 5°C.

[0058] Start to observe the temperature rise in the reactor. If there is no obvious temperature rise, there is no need to turn on the refrigeration.

[0059] Step 6: Keep warm at 5℃ for 2 hours and then discharge the material.

[0060] Step 7: Wash with water 5 times to clean the remaining catalyst.

[0061] Step 8: Desolventize toluene at a distillation temperature of 235° C., maintain the vacuum degree at -0.095 MPa, and discharge the material after 10 minutes to obtain a terpene resin with controllable molecular weight.

[0062] Example 2

[0063] A method for preparing a terpene resin with controllable molecular weight, which is different from that of Example 1 in that it comprises the following steps:

[0064] Step 1: Prepare raw materials according to the ratio of 2000kg of toluene (gas chromatographic analysis content 99.8%), 2000kg of β-pinene (gas chromatographic analysis content 98%), 0.8kg of ethylene glycol, and 70kg of catalyst (anhydrous antimony trichloride).

[0065] Step 2: Stir β-pinene for 30 minutes and then let it stand for 30 minutes to separate the water before reuse. Control the water content of β-pinene at 250ppm. Add ethylene glycol into β-pinene and stir evenly to obtain a mixture for standby use.

[0066] Step 3: Check whether the bottom valve of the polymerization kettle is in the closed state, check whether the bottom valves of the mixture and toluene metering tanks are closed, check whether the exhaust gas venting system is unobstructed, pump the mixture and toluene into the high-level tank metering tank respectively, let it stand for 30 minutes, and confirm again that the water is drained cleanly.

[0067] Step 4: Open the bottom valve of the toluene metering tank and pour the prepared anhydrous toluene directly into the polymerization reactor, making sure to pour it all in to avoid affecting the reaction.

[0068] Start the polymerization kettle and stir. (In summer) open the chilled water inlet valve and the cold brine pump. When the toluene in the kettle drops to 5°C, turn off the brine pump. The temperature will continue to drop (no cooling is required if the outdoor temperature is as low as -5°C).

[0069] When the kettle temperature drops to 5°C, put the catalyst into the reactor.

[0070] Step 5: When there is no obvious temperature rise in the reactor, the mixture can be added dropwise. The first addition will cause the temperature to rise to 3-5°C.

[0071] Turn on the brine pump again and continue to cool down to 1°C. Add the mixture again for reaction, and control the temperature between 1-3°C. Do not cool down until there is 0kg left in the measuring tank.

[0072] Start to observe the temperature rise in the reactor. If there is no obvious temperature rise, there is no need to turn on the refrigeration.

[0073] Step 6: Keep warm at 10℃ for 1 hour and then discharge the material.

[0074] Step 7: Wash with water 5 times to clean the remaining catalyst.

[0075] Step 8: Desolventize toluene at a distillation temperature of 230° C., maintain the vacuum degree at -0.085 MPa, and discharge the material after 10 minutes to obtain a terpene resin with controllable molecular weight.

[0076] Example 3

[0077] A method for preparing a terpene resin with controllable molecular weight, which is different from that of Example 1 in that it comprises the following steps:

[0078] Step 1: Prepare raw materials in the proportion of 2300 kg of toluene (gas chromatography content 99.8%), 2000 kg of β-pinene (gas chromatography content 98%), 1.4 kg of ethylene glycol, and 100 kg of catalyst (anhydrous titanium tetrachloride).

[0079] Step 2: Stir β-pinene for 30 minutes and then let it stand for 30 minutes to separate the water before reuse. Control the water content of β-pinene at 250ppm. Add ethylene glycol into β-pinene and stir evenly to obtain a mixture for standby use.

[0080] Step 3: Check whether the bottom valve of the polymerization kettle is in the closed state, check whether the bottom valves of the mixture and toluene metering tanks are closed, check whether the exhaust gas venting system is unobstructed, pump the mixture and toluene into the high-level tank metering tank respectively, let it stand for 30 minutes, and confirm again that the water is drained cleanly.

[0081] Step 4: Open the bottom valve of the toluene metering tank and pour the prepared anhydrous toluene directly into the polymerization reactor, making sure to pour it all in to avoid affecting the reaction.

[0082] Start stirring the polymerization kettle, open the chilled water inlet valve (in summer), start the cold brine pump, and close the brine pump when the toluene in the kettle drops to 5°C.

[0083] When the kettle temperature drops to -5°C, put the catalyst into the reactor.

[0084] Step 5: When there is no obvious temperature rise in the reactor, the mixture can be added dropwise. The first addition will cause the temperature to rise to 3-5°C.

[0085] Turn on the brine pump again and let the temperature reach 1°C. Add the mixture again for reaction, and control the temperature between 1-3°C. Do not lower the temperature until 0 kg is left in the measuring tank, and keep it at 6°C.

[0086] Start to observe the temperature rise in the reactor. If there is no obvious temperature rise, there is no need to turn on the refrigeration.

[0087] Step 6: Keep warm at 6℃ for 3 hours and then discharge the material.

[0088] Step 7: Wash with water 5 times to clean the remaining catalyst.

[0089] Step 8: Desolventize toluene at a distillation temperature of 240° C., maintain the vacuum degree at -0.099 MPa, and discharge the material after 10 minutes to obtain a terpene resin with controllable molecular weight.

[0090] Comparative Example

[0091] Comparative Example 1

[0092] A method for preparing a terpene resin with controllable molecular weight, which is different from Example 1 in that ethylene glycol is omitted.

[0093] Comparative Example 2

[0094] A method for preparing a terpene resin with controllable molecular weight, which is different from Example 1 in that ethylene glycol is replaced by propylene glycol.

[0095] Performance testing

[0096] 1. Softening point: The terpene resins with controlled molecular weight of Examples 1-3 and Comparative Examples 1-2 were tested with reference to GB 12007.6-89 "Measurement method for softening point of epoxy resin - Ring and ball method".

[0097] After testing, the softening points of the terpene resins with controllable molecular weight in Examples 1-3 and Comparative Examples 1-2 all meet the standard of T-135°C.

[0098] 2. Number average molecular weight: The molecular weight distribution of the terpene resins with controlled molecular weight of Examples 1-3 and Comparative Examples 1-2 was measured, and the number average molecular weight was recorded in Table 1.

[0099] Molecular weight test report reference Figure 1-5 .

[0100] 3. Sanitary tape performance test:

[0101] Preparation of sanitary tape: 40 g of the terpene resin with controlled molecular weight of Examples 1-3 and Comparative Examples 1-2, 40 g of natural resin, and 20 g of cyclohexane oil were added to 100 g of ethyl acetate and mixed evenly, reacted at room temperature for 12 h, and then coated on a substrate (Singa release film), and the ethyl acetate was vacuum dried at 120° C. to obtain a sanitary tape.

[0102] The coating thickness is 150 μm.

[0103] Test items:

[0104] (1) Ring tack test: Test according to GB / T 31125-2014 “Test method for initial tack of adhesive tapes: Ring method” and record the tensile force in Table 1.

[0105] (2) 24h peel test: The test was conducted in accordance with GB / T 2792-2014 “Test method for peel strength of adhesive tapes”. The average peel force and peel strength were recorded in Table 1.

[0106] (3) Adhesion performance: The test was conducted in accordance with method A of GB / T 4851-2014 “Test method for adhesion performance of adhesive tapes”.

[0107] The control conditions are 1kg, 25mm*25mm, and 40℃, that is, one end of the tape is adhered to the 25mm*25mm area of ​​the stainless steel sample, a weight of 1KG is suspended at the lower end, and the experimental temperature is 40℃.

[0108] Test chart reference Figure 6 .

[0109] The sticking time is recorded in Table 1.

[0110] Table 1

[0111]

[0112] According to the test data in Table 1, although the softening points of the terpene resins with controllable molecular weights of Examples 1-3 and Comparative Examples 1-2 all meet the standard of T-135°C, due to the different molecular weights, the sanitary tapes prepared using the terpene resins of Examples 1-3 and Comparative Examples 1-2 have very large differences in performance.

[0113] The sanitary tape prepared from the terpene resin with a molecular weight controlled at 4100-4200 showed excellent performance in the tests of initial adhesion, sustained adhesion, peelability, etc., which were far better than those of comparative examples 1-2.

[0114] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing a terpene resin with controllable molecular weight, characterized in that: The following steps are involved: Step 1: mixing β-pinene and ethylene glycol until uniform to obtain a mixture; the water content of the β-pinene is below 250 ppm; Step 2: Mix toluene and catalyst evenly at -5~5°C; Step 3: Add the mixture dropwise and keep warm at 5-10°C for 1-3h; Step 4: Clean and remove the residual catalyst; Step 5: desolventizing toluene at a distillation temperature of 230-240° C. and a vacuum degree of -0.085 to -0.099 MPa to obtain a terpene resin with controllable molecular weight; The mass ratio of toluene to β-pinene is (1-1.15):1, the amount of the catalyst used is 3.5-5% of the mass of β-pinene, and the amount of ethylene glycol used is 0.04-0.07% of the mass of β-pinene.

2. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: The mass ratio of toluene to β-pinene is 1.1:1, the amount of the catalyst used is 3.5% of the mass of the β-pinene, and the amount of ethylene glycol used is 0.05% of the mass of the β-pinene.

3. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: In the step 3, after the material in step 2 has no obvious temperature rise, the mixture is added dropwise.

4. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: In step 3, when the mixture is added dropwise to the material in step 2 for the first time, the temperature is controlled to rise by 3-5°C, and then the temperature is dropped to 0-2°C, and then the mixture is continued to be added dropwise, and the dropping temperature is controlled at 1-3°C.

5. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: In the step 3, after the mixture is added dropwise, the mixture is kept warm at 5-6° C. for 1-3 hours.

6. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: Before the mixture is added dropwise, the β-pinene is stirred for 30 minutes and then allowed to stand for 30 minutes to separate the water; and then mixed with ethylene glycol until uniform to obtain a mixture.

7. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: The catalyst comprises at least one of anhydrous aluminum trichloride, anhydrous antimony trichloride and anhydrous titanium tetrachloride.

8. The method for preparing a terpene resin with controllable molecular weight according to claim 1, characterized in that: In step 4, the residual catalyst is washed away by washing with water for multiple times.

9. A terpene resin with controllable molecular weight obtained by the method for preparing a terpene resin with controllable molecular weight according to any one of claims 1 to 8.

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