Preparation method of AES resin

Abstract

The invention relates to the field of plastics, and particularly discloses a preparation method of AES (acrylonitrile-ethylene-propylene-diene monomer styrene) resin, which comprises the following steps: dissolving an initiator in acetone to prepare an initiator solution; and uniformly mixing the initiator solution, the AS resin and the POE, putting the mixture into an extruder, and carrying out extrusion granulation to obtain the AES resin. According to the present invention, the AS resin and the POE are adopted as the raw materials, the appropriate initiator is selected for compounding, and the reasonable temperature interval setting is adopted so as to easily achieve the industrial synthesis of the AES resin;

Description

Technical Field

[0001] The present invention relates to the field of plastics, and more specifically, to a method for preparing an AES resin. Background Art

[0002] ABS resin refers to acrylonitrile-butadiene-styrene copolymer, which is a thermoplastic polymer material with high rigidity, high toughness and easy processing. Since butadiene rubber contains double bonds, ABS has the defect of weather resistance and is not suitable for outdoor use. Based on this, there are two alternative resins, one is to use A (acrylic rubber) instead of B (butadiene rubber), that is, ASA resin; the other is to use E (POE or EPDM) instead of B (butadiene rubber), that is, AES resin.

[0003] AES resin, acrylonitrile-polyolefin elastomer-styrene copolymer, is a new type of engineering plastic developed to address the poor weather resistance of ABS. It is widely used in the fields of electronics, automotive parts, outdoor building materials, etc. AES resin has excellent aging resistance and can maintain its performance even under long-term outdoor ultraviolet irradiation. Its low-temperature impact resistance is also better than that of ABS and ASA.

[0004] At present, the core technology of AES resin production is basically mastered by foreign companies, with few documents and patents disclosed, and this part of technology is almost blank in China. Therefore, how to develop an industrialized synthesis route for preparing AES resin is of great significance. Summary of the invention

[0005] In order to solve the above problems, the present application provides a method for preparing an AES resin.

[0006] The present application provides a method for preparing an AES resin, which adopts the following technical scheme:

[0007] A method for preparing an AES resin comprises the following steps:

[0008] dissolving the initiator in acetone to prepare an initiator solution;

[0009] The initiator solution, AS resin and POE are mixed evenly, put into an extruder, and extruded into granules to obtain AES resin.

[0010] By adopting the above technical scheme, AS resin, i.e. acrylonitrile-styrene copolymer, is a thermoplastic resin obtained by copolymerization of acrylonitrile and styrene monomers, and is a transparent solid with yellow to amber color and a density of 1.06 g / cm 3 .

[0011] POE is a polyolefin elastomer, a thermoplastic elastomer formed by the polymerization of ethylene and α-olefin. POE combines the properties of plastic and rubber, has high elasticity and toughness of rubber at room temperature, and can be plasticized and molded at high temperature. The content of α-olefin in the POE comonomer is high, the density is low, and it has excellent weather resistance and aging resistance.

[0012] The present invention uses AS resin and POE as raw materials, selects a suitable initiator for compounding, and adopts a reasonable temperature range setting to facilitate the depolymerization of AS resin and achieve block copolymerization to obtain AES resin. The synthetic route is simple and has a high yield, which is of great significance for the industrial production of AES resin.

[0013] Optionally, the added amount of the initiator solution accounts for 0.1-0.2 wt % of the mass of the AS resin, and the initiator includes n-dodecyl mercaptan, 1,1-di-tert-butyl cyclohexyl peroxide and an initiator aid mixed in equal weight ratios.

[0014] By adopting the above technical solution, the initiator plays a vital role in the synthesis of block copolymers. Based on the difficulty of polymerizing AS resin and POE, this application uses three initiators for compounding in order to improve the yield of AES resin.

[0015] n-Dodecyl mercaptan plays a major role in chain transfer in free radical polymerization reactions. It reacts with active free radicals to form SR bonds, and generates new free radicals and chain transfer products, which then re-enter the polymerization reaction to initiate the growth of new polymer chains, thereby prolonging the polymerization reaction time and controlling the degree of polymerization and molecular weight distribution.

[0016] 1,1-di-tert-butyl cyclohexyl peroxide decomposes under heating conditions to generate tert-butyl peroxy radicals and tert-butyl radicals. These radicals are highly reactive and can initiate the polymerization reaction of monomers. In addition, 1,1-di-tert-butyl cyclohexyl peroxide and the initiator co-agent can synergistically break the AS resin chain segments to facilitate block copolymerization.

[0017] Optionally, the preparation process of the initiator aid is as follows:

[0018] In parts by weight, 10-15 parts of 3,5-dichlorosalicylic acid, 50-60 parts of ether and 1-2 parts of p-toluenesulfonic acid are first mixed, the temperature is raised to 130-140° C., and the mixture is stirred for reaction for 3-5 hours. After the reaction is completed, the ether is removed by vacuum distillation, and then 5-8 parts of a saturated sodium bicarbonate solution are added. After standing and stratification, the organic layer is extracted with toluene, washed with water for 1-3 times, and then evaporated and recrystallized to obtain a first product;

[0019] First, 4-5 parts of triethylamine and 6-8 parts of toluene are mixed, and then 12-15 parts of the first product and 50-60 parts of toluene are added. After mixing evenly, nitrogen is introduced for protection. Then, 4-5 parts of oxalyl chloride are added under ice-water bath conditions, and the reaction is stirred continuously for 2-3 hours. After the reaction is completed, the filtrate is filtered to obtain the filtrate, the toluene is evaporated and the initiator is obtained by recrystallization with petroleum ether.

[0020] By adopting the above technical solution, the initiator auxiliary has high reaction activity, is suitable for the polymerization process of AS resin and POE, and can significantly improve the yield.

[0021] Optionally, the initiator solution is added in multiple times.

[0022] By adopting the above technical scheme, firstly, adding the initiator in batches can avoid excessive local concentration, thereby preventing the occurrence of implosion, which will cause the reaction to be too violent and difficult to control, which may increase costs and affect product quality; secondly, the reaction conversion rate can be improved; thirdly, adding the initiator in batches can better control the molecular weight and molecular weight distribution of the polymer, maintain the linear rate of the polymerization reaction, and keep the polymer molecular weight at a high level; fourthly, slowly adding the initiator is conducive to forming a uniform polymer structure and improving the performance of the product; fifthly, adding the initiator in batches can better control the reaction temperature and reaction rate, so that the polymerization reaction can proceed more smoothly, especially for the polymerization process of AS resin and POE with higher reaction requirements.

[0023] Optionally, the mass ratio of the AS resin to POE is (8-10):1.

[0024] Optionally, the molecular weight of the AS resin is less than 200,000 and the acrylonitrile content is 20-30 wt%.

[0025] Optionally, the melt index of the POE is 2-10 g / 10 min.

[0026] By adopting the above technical solution, the ratio of acrylonitrile to styrene is the main factor affecting the performance of AS resin. The higher the acrylonitrile content, the higher the hardness and strength of the resin, the better the heat resistance and chemical resistance, but the toughness and processing performance will be reduced.

[0027] The molecular weight of AS resin also has a significant impact on its performance. High molecular weight AS resin usually requires higher processing temperature to ensure that the polymer chain can flow fully. Based on this, the use of low molecular weight AS resin is conducive to extrusion processing, and the entanglement and interaction between chains are weak, and it is easy to depolymerize.

[0028] The melt index is a key parameter to measure the fluidity of plastics during processing. It can reflect the molecular weight of the polymer. The larger the molecular weight, the smaller the melt index and the worse the fluidity of the material. Conversely, the smaller the molecular weight, the larger the melt index and the better the fluidity of the material.

[0029] Based on the production requirements of extrusion granulation, the mass ratio of AS resin and POE and the performance parameters of AS resin and POE are preferably selected to facilitate the smooth reaction and thus improve the yield.

[0030] Optionally, the extruder is a twin-screw extruder with a length-to-diameter ratio of (48-64):1.

[0031] By adopting the above technical solution, the aspect ratio (L / D) of the twin-screw extruder refers to the ratio of the effective length of the screw to the screw diameter. This parameter has an important influence on the performance and applicability of the extruder. In general polymer processing operations, the aspect ratio is usually between 24-48.

[0032] The present application adopts a larger aspect ratio, which can improve the shearing, dispersion, mixing and conveying capabilities of the twin-screw extruder, and has advantages in polymer chain disentanglement in particular, and is suitable for the synthesis route of the present application.

[0033] Optionally, based on the mass percentage of the AS resin, 2-3 wt% cashew nut shell oil is further added.

[0034] By adopting the above technical solution, the addition of cashew nut shell oil can, firstly, act as a compatibilizer, which can reduce steric hindrance and thus more effectively enhance the interfacial reaction; secondly, it can act as a toughening agent. Cashew nut shell oil molecules contain a long carbon chain structure, which utilizes the flexibility of the long carbon chain to form a flexible network to absorb impact energy, thereby improving the toughness and impact strength of the material.

[0035] Optionally, the processing temperature of the extruder is set in four sections along the extrusion direction, namely 160-180°C, 190-200°C, 230-240°C, and 250-260°C.

[0036] By adopting the above technical solution, the temperature range is optimized to improve the yield.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. This application uses AS resin and POE as raw materials, selects a suitable initiator for compounding, and adopts a reasonable temperature range setting to facilitate the depolymerization of the AS resin and achieve block copolymerization to obtain an AES resin with excellent aging performance. The synthetic route is simple and has a high yield, which is of great significance for the industrial production of AES resin.

[0039] 2. In the present application, n-dodecyl mercaptan, 1,1-di-tert-butyl cyclohexyl peroxide and an initiator aid are preferably used as the initiator, which is suitable for the synthesis route of the present application and can improve the yield.

[0040] 3. Based on the production requirements of extrusion granulation, the present application preferably selects the mass ratio of AS resin and POE, and the performance parameters of AS resin and POE, so as to facilitate the smooth reaction and thus improve the yield.

[0041] 4. The present application preferably adds cashew nut shell oil, firstly, it acts as a compatibilizer, which can reduce steric hindrance and thus more effectively enhance the interfacial reaction; secondly, it acts as a toughening agent. The cashew nut shell oil molecules contain a long carbon chain structure, which takes advantage of the flexibility of the long carbon chain to form a flexible network, absorb impact energy, and thus improve the toughness and impact strength of the material. DETAILED DESCRIPTION

[0042] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0043] Preparation Example 1:

[0044] The preparation process of the initiator is as follows:

[0045] In parts by weight, 10 parts of 3,5-dichlorosalicylic acid, 50 parts of ether and 1 part of p-toluenesulfonic acid were first mixed, the temperature was raised to 130° C., and the mixture was stirred for reaction for 3 hours. After the reaction was completed, the ether was removed by distillation under reduced pressure, and then 5 parts of a saturated sodium bicarbonate solution were added. After standing and stratification, the organic layer was extracted with toluene, washed with water once, and then evaporated and recrystallized to obtain the first product;

[0046] First, 4 parts of triethylamine and 6 parts of toluene were mixed, and then 12 parts of the first product and 50 parts of toluene were added. After mixing evenly, nitrogen was introduced for protection. Then, 4 parts of oxalyl chloride were added under ice-water bath conditions, and the reaction was stirred continuously for 2 hours. After the reaction was completed, the filtrate was filtered to obtain the filtrate, the toluene was evaporated and recrystallized with petroleum ether to obtain the initiator aid.

[0047] Preparation Example 2:

[0048] The preparation process of the initiator is as follows:

[0049] By weight, 15 parts of 3,5-dichlorosalicylic acid, 60 parts of ether and 2 parts of p-toluenesulfonic acid were mixed, the temperature was raised to 140°C, and the mixture was stirred for reaction for 5 hours. After the reaction was completed, the ether was removed by vacuum distillation, and then 8 parts of a saturated sodium bicarbonate solution were added. After standing for stratification, the organic layer was extracted with toluene, washed with water 3 times, evaporated and recrystallized to obtain the first product;

[0050] First, 5 parts of triethylamine and 8 parts of toluene were mixed, and then 15 parts of the first product and 60 parts of toluene were added. After mixing evenly, nitrogen was introduced for protection. Then, 5 parts of oxalyl chloride were added under ice-water bath conditions, and the reaction was stirred continuously for 3 hours. After the reaction was completed, the filtrate was filtered to obtain the filtrate, the toluene was evaporated, and the initiator was recrystallized with petroleum ether to obtain the initiator aid.

[0051] Preparation Example 3:

[0052] The preparation process of the initiator is as follows:

[0053] By weight, 12 parts of 3,5-dichlorosalicylic acid, 55 parts of ether and 1.5 parts of p-toluenesulfonic acid were mixed, the temperature was raised to 135°C, and the mixture was stirred for reaction for 4 hours. After the reaction was completed, the ether was removed by vacuum distillation, and then 6 parts of a saturated sodium bicarbonate solution were added. After standing for stratification, the organic layer was extracted with toluene, washed with water twice, evaporated and recrystallized to obtain the first product;

[0054] First, 4.5 parts of triethylamine and 7 parts of toluene were mixed, and then 13 parts of the first product and 55 parts of toluene were added. After mixing evenly, nitrogen was introduced for protection. Then, 4.5 parts of oxalyl chloride were added under ice-water bath conditions, and the reaction was stirred continuously for 2.5 hours. After the reaction was completed, the filtrate was filtered to obtain the filtrate, the toluene was evaporated and the initiator was recrystallized with petroleum ether to obtain the initiator aid.

[0055] Preparation Example 4:

[0056] Preparation method of cashew nut shell liquid:

[0057] Select fresh cashew nut shell as raw material, ensure that it is dry and free of impurities, crush it, mix it with acetone, perform primary leaching, stir at a speed of 100 r / min, stir at a temperature of 30° C., filter to obtain a filtrate, evaporate the filtrate at 100° C. for 20 minutes, and obtain crude cashew nut shell oil;

[0058] The crude cashew nut shell liquid was refined, heated to 80°C at a heating rate of 5°C / min, and maintained for 20 minutes; further heated to 110°C at a heating rate of 5°C / min, maintained for 60 minutes, and then heated to 165°C at a heating rate of 1°C / min, and maintained for 20 minutes to obtain cashew nut shell liquid.

[0059] Embodiment 1:

[0060] A method for preparing an AES resin comprises the following steps:

[0061] In the first step, n-dodecyl mercaptan, 1,1-di-tert-butyl cyclohexyl peroxide and the initiator aid prepared in Preparation Example 1 are mixed in equal mass ratios as an initiator; the initiator is dissolved in acetone in a mass ratio of 1:10 to prepare an initiator solution;

[0062] In the second step, the initiator solution, AS resin and POE are mixed evenly and put into a twin-screw extruder for extrusion granulation to obtain AES resin; the mass ratio of AS resin to POE is 8:1, the addition amount of the initiator solution accounts for 0.1wt% of the mass of the AS resin, the initiator solution is added in 3 times, the aspect ratio of the extruder is 40:1, and the processing temperature of the extruder is set in four sections along the extrusion direction, which are 160°C, 190°C, 230°C, and 250°C respectively.

[0063] The brand of AS resin is SAN DN59, purchased from INEOS, with a molecular weight of less than 200,000 and an acrylonitrile content of 20-30 wt%. The brand of POE is 8200, purchased from Dow Chemical, USA, with a melt index of 5 g / 10 min.

[0064] Embodiment 2:

[0065] A method for preparing an AES resin comprises the following steps:

[0066] In the first step, n-dodecyl mercaptan, 1,1-di-tert-butyl cyclohexyl peroxide and the initiator aid prepared in Preparation Example 2 are mixed in equal mass ratios as an initiator; the initiator is dissolved in acetone in a mass ratio of 1:10 to prepare an initiator solution;

[0067] In the second step, the initiator solution, AS resin and POE are mixed evenly and put into a twin-screw extruder for extrusion granulation to obtain AES resin; the mass ratio of AS resin to POE is 10:1, the addition amount of the initiator solution accounts for 0.2wt% of the mass of the AS resin, the initiator solution is added in 3 times, the aspect ratio of the extruder is 40:1, and the processing temperature of the extruder is set in four sections along the extrusion direction, which are 180°C, 200°C, 240°C, and 260°C respectively.

[0068] The brand of AS resin is SAN DN59, purchased from INEOS, with a molecular weight of less than 200,000 and an acrylonitrile content of 20-30 wt%. The brand of POE is 8200, purchased from Dow Chemical, USA, with a melt index of 5 g / 10 min.

[0069] Embodiment 3:

[0070] A method for preparing an AES resin comprises the following steps:

[0071] In the first step, n-dodecyl mercaptan, 1,1-di-tert-butyl cyclohexyl peroxide and the initiator aid prepared in Preparation Example 3 are mixed in equal mass ratios as an initiator; the initiator is dissolved in acetone in a mass ratio of 1:10 to prepare an initiator solution;

[0072] In the second step, the initiator solution, AS resin and POE are mixed evenly and put into a twin-screw extruder for extrusion granulation to obtain AES resin; the mass ratio of AS resin to POE is 9:1, the addition amount of the initiator solution accounts for 0.15wt% of the mass of the AS resin, the initiator solution is added in 3 times, the aspect ratio of the extruder is 40:1, and the processing temperature of the extruder is set in four sections along the extrusion direction, which are 170°C, 195°C, 235°C, and 255°C respectively.

[0073] The brand of AS resin is SAN DN59, purchased from INEOS, with a molecular weight of less than 200,000 and an acrylonitrile content of 20-30 wt%. The brand of POE is 8200, purchased from Dow Chemical, USA, with a melt index of 5 g / 10 min.

[0074] Embodiment 4:

[0075] The difference from Example 3 is that the aspect ratio of the extruder is 48:1.

[0076] Embodiment 5:

[0077] The difference from Example 3 is that the aspect ratio of the extruder is 56:1.

[0078] Embodiment 6:

[0079] The difference from Example 3 is that the aspect ratio of the extruder is 64:1.

[0080] Embodiment 7:

[0081] The difference from Example 6 is that the initiator solution is added in 5 portions.

[0082] Embodiment 8:

[0083] The difference from Example 6 is that the initiator solution is added in two portions.

[0084] Embodiment 9:

[0085] The difference from Example 6 is that the initiator solution is not added in portions.

[0086] Embodiment 10:

[0087] The difference from Example 6 is that, based on the mass percentage of AS resin, 2 wt % of cashew nut shell liquid prepared in Preparation Example 4 is further added.

[0088] Embodiment 11:

[0089] The difference from Example 6 is that, based on the mass percentage of AS resin, 3 wt % of cashew nut shell liquid prepared in Preparation Example 4 is further added.

[0090] Embodiment 12:

[0091] The difference from Example 6 is that the initiator is only n-dodecyl mercaptan.

[0092] Embodiment 13:

[0093] The difference from Example 6 is that the initiator is only 1,1-di-tert-butyl cyclohexylperoxide.

[0094] Comparative Example 1:

[0095] Commercially available ABS was used.

[0096] Comparative Example 2:

[0097] Commercially available ASA was used.

[0098] Table 1 AES resin yield results of Examples 1-13

[0099]

[0100]

[0101] From Table 1, we can get:

[0102] The present application preferably uses a compound of n-dodecyl mercaptan, 1,1-di-tert-butyl cyclohexyl peroxide and an initiator aid as an initiator, which is suitable for the synthesis route of the present application and can improve the yield; in addition, cashew nut shell oil is preferably added and the aspect ratio is preferably selected, which is also helpful for the polymerization reaction.

[0103] Performance Test:

[0104] Impact strength, tensile strength and aging performance tests were performed on Examples 1-3, Example 10, Example 11 and Comparative Example 1 and Comparative Example 2. The impact strength test standard was based on ASTM D256, and the tensile strength test standard was based on ASTM D638. The results are shown in Table 2.

[0105] Table 2 Performance test result record

[0106]

[0107]

[0108] It can be seen from Table 2 that the AES resin prepared in the present application has not only good aging performance, but also excellent mechanical strength and can be used to replace ABS resin and ASA resin.

[0109] 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 an AES resin, characterized in that: The steps include: dissolving the initiator in acetone to prepare an initiator solution; The initiator solution, AS resin and POE are mixed evenly, put into an extruder, and extruded into granules to obtain AES resin.

2. The method for preparing the AES resin according to claim 1, wherein: The added amount of the initiator solution accounts for 0.1-0.2wt% of the mass of the AS resin, and the initiator comprises n-dodecyl mercaptan, 1,1-di-tert-butyl peroxide cyclohexane and an initiator auxiliary mixed in equal mass ratio.

3. The method for preparing the AES resin according to claim 2, characterized in that: The preparation process of the initiator aid is as follows: In parts by weight, 10-15 parts of 3,5-dichlorosalicylic acid, 50-60 parts of ether and 1-2 parts of p-toluenesulfonic acid are first mixed, the temperature is raised to 130-140° C., and the mixture is stirred for reaction for 3-5 hours. After the reaction is completed, the ether is removed by vacuum distillation, and then 5-8 parts of a saturated sodium bicarbonate solution are added. After standing and stratification, the organic layer is extracted with toluene, washed with water for 1-3 times, and then evaporated and recrystallized to obtain a first product; First, 4-5 parts of triethylamine and 6-8 parts of toluene are mixed, and then 12-15 parts of the first product and 50-60 parts of toluene are added. After mixing evenly, nitrogen is introduced for protection. Then, 4-5 parts of oxalyl chloride are added under ice-water bath conditions, and the reaction is stirred continuously for 2-3 hours. After the reaction is completed, the filtrate is filtered to obtain the filtrate, the toluene is evaporated and the initiator is obtained by recrystallization with petroleum ether.

4. The method for preparing the AES resin according to claim 2, characterized in that: The initiator solution is added in multiple times.

5. The method for preparing the AES resin according to claim 1, characterized in that: The mass ratio of the AS resin to POE is (8-10):

1.

6. The method for preparing the AES resin according to claim 5, characterized in that: The molecular weight of the AS resin is less than 200,000, and the acrylonitrile content is 20-30 wt%.

7. The method for preparing the AES resin according to claim 5, characterized in that: The melt index of the POE is 2-10 g / 10 min.

8. The method for preparing the AES resin according to claim 1, characterized in that: The extruder is a twin-screw extruder with a length-to-diameter ratio of (48-64):

1.

9. The method for preparing the AES resin according to claim 1, characterized in that: Based on the mass percentage of the AS resin, 2-3 wt% cashew nut shell oil is also added.

10. The method for preparing the AES resin according to claim 1, characterized in that: The processing temperature of the extruder is set in four stages along the extrusion direction, which are 160-180°C, 190-200°C, 230-240°C, and 250-260°C.

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