A toughening modifier for polyester and its preparation method

Abstract

This invention relates to a toughening modifier for polyester and its preparation method. The toughening modifier comprises 85.0-97.2 parts by weight of chlorinated polyethylene, 0.8-5.0 parts by weight of a compatibilizer, 0.01-0.2 parts by weight of an initiator, 0.5-6.0 parts by weight of a filler, and a stabilizer; wherein the chlorinated polyethylene has a chlorine content of 8-25%, a glass transition temperature < -20°C, and 0 ≤ residual crystallinity < 15%; the thermal decomposition temperature of the toughening modifier is > 200°C. Modified polyester modified with the toughening modifier and its modification method are also provided. This toughening modifier exhibits good thermal stability and can improve the processing and molding effect and impact toughness of polyester resin.

Description

Technical Field

[0001] This invention relates to the field of toughening agent technology, specifically to a toughening modifier for polyester and its preparation method. Background Technology

[0002] Polyester materials are thermoplastic engineering plastics, including polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene terephthalate-1,4-cyclohexanediol (PETG). Polyester materials possess good mechanical properties, weather resistance, abrasion resistance, electrical insulation, and chemical stability, and are widely used in fibers, films, beverage bottles, and packaging.

[0003] Due to the excellent properties and reasonable price of polyester materials, after years of development, China has formed a polyester material production capacity of over 70 million tons. Its main application area is the fiber industry, commonly known as polyester fiber, followed by bottle flakes and packaging. The continuous expansion of polyester material production capacity, along with the waste from clothing, beverage bottles, and packaging materials, has resulted in significant idle capacity and pollution from waste plastics. Developing new application areas for polyester materials has become an urgent issue that the polyester industry and environmental protection efforts need to address.

[0004] The domestic SPC flooring and carbon crystal board market is currently developing rapidly. These products are mainly made by extruding and shaping polyvinyl chloride (PVC) and calcium powder to create stone-plastic flooring, replacing laminate flooring and artificial decorative panels. They offer advantages such as low cost, no formaldehyde, no odor, and easy maintenance, and are widely used in interior decoration, with large quantities exported to Europe and America. However, these products also have disadvantages such as short replacement cycles, low recycling value, and long degradation periods, making them subject to environmental protection requirements. Polyester materials, on the other hand, are easily hydrolyzed, have short degradation cycles, high strength, and are widely available, making them an ideal alternative to SPC flooring. They not only improve the performance of flooring and wall panels but also enable efficient utilization of polyester production capacity.

[0005] Flooring and wall covering materials require high dimensional stability. To achieve excellent dimensional stability, a large amount of inorganic filler needs to be added, which exacerbates the difficulties in processing and molding polyester materials and their high brittleness. The problem of high brittleness in PET and PETG materials can be solved by developing toughening modifiers with good compatibility with polyester materials, good thermal stability, and high impact toughness. Compared to POE, EBA, and maleic anhydride graft polymers, chlorinated polyethylene has a significant price advantage. However, traditional chlorinated polyethylene products have a thermal decomposition temperature of around 165℃, while polyester material processing temperatures need to be above 200℃. Under these processing conditions, chlorinated polyethylene decomposes upon heating, releasing hydrogen chloride gas, which reduces performance and causes equipment corrosion. Therefore, traditional chlorinated polyethylene products cannot be used in the toughening of polyester materials. Summary of the Invention

[0006] The purpose of this application is to provide a toughening modifier for polyester that can adapt to the high processing temperature requirements of polyester materials, can be well dispersed in polyester materials and provide excellent toughening effect, thereby solving the problem of high brittleness of existing polyester materials.

[0007] To achieve one aspect of the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] A toughening modifier for polyester is prepared from a raw material comprising the following components in parts by weight:

[0009]

[0010] The chlorinated polyethylene has a chlorine content of 8-25 wt%, a glass transition temperature of <-20℃, and a residual crystallinity of 0 ≤ <15%.

[0011] The residual crystallinity was determined by the heat of fusion using the differential scanning calorimetry method according to national standard GB / T 19466.3-2004, and calculated by the following formula:

[0012] Residual crystallinity = Heat of melt of chlorinated polyethylene / Theoretical heat of melt of HDPE with 100% crystallinity;

[0013] The thermal decomposition temperature of the toughening modifier is >200℃;

[0014] Preferably, the chlorine content of the chlorinated polyethylene is 8-18 wt%, and the thermal decomposition temperature of the toughening modifier is >245℃.

[0015] In a preferred embodiment, the compatibilizer is glycidyl methacrylate (GMA).

[0016] To achieve another aspect of the above-mentioned objective, the present invention also provides a method for preparing the toughening modifier, comprising the following steps:

[0017] Step 1): Add 0.05-0.5 parts by weight of dispersant and 0.005-0.06 parts by weight of emulsifier to the reactor, then add water to make the total weight of the dispersant, emulsifier and water 150 parts by weight. Then add 20-30 parts by weight of high-density polyethylene. Inert gas is introduced from the bottom of the reactor to remove oxygen from the reaction liquid and the gas phase at the top of the reactor. The reaction material is heated to 80-105°C with stirring. 3.5-20 parts by weight of chlorine gas is introduced at the same time and the temperature is raised to 120-140°C. After the chlorine gas is introduced, the mixture is cooled to below 100°C, deacidified, neutralized, washed with water, centrifuged and dried to obtain chlorinated polyethylene with a chlorine content of 8-25 wt%, a glass transition temperature of <-20°C and 0 ≤ residual crystallinity <15%.

[0018] Step 2): Weigh 85.0-97.2 parts by weight of chlorinated polyethylene, 0.8-5.0 parts by weight of compatibilizer, 0.01-0.2 parts by weight of initiator, 0.5-6.0 parts by weight of filler, and 0.5-4.0 parts by weight of stabilizer, put them into a mixer and stir for 2-5 minutes, then discharge the material for later use.

[0019] Step 3): The mixed material is extruded and granulated by a twin-screw extruder to obtain the toughening modifier.

[0020] In another aspect of achieving the above-mentioned objective, the present invention also provides a modified polyester, wherein the modified polyester is a polyester modified using the above-mentioned toughening modifier.

[0021] In another aspect of achieving the above-mentioned objective, the present invention further provides a method for preparing the modified polyester.

[0022] Compared with the prior art, this application has the following beneficial effects:

[0023] (1) The toughening modifier of this application has high thermal stability. It is prepared by combining chlorinated polyethylene material with glass transition temperature < -20℃, 0≤ residual crystallinity <15%, and chlorine content of 8~25wt% with other components. The resulting modifier has a good toughening effect on polyester and can improve the processing and molding effect and impact toughness of polyester resin.

[0024] (2) Preferably, this application further improves the compatibility between the toughening modifier and the polyester material without affecting the heat resistance stability of the toughening modifier by grafting glycidyl methacrylate onto the chlorinated polyethylene material, thereby promoting the dispersion of the toughening modifier in the polyester material and giving full play to its toughening modification effect.

[0025] (3) Preferably, in the preparation process of chlorinated polyethylene, before chlorine is introduced, an inert gas is injected into the reactor to continuously replace the oxygen in the reaction liquid and the gas phase on the surface of the reactor liquid, thereby reducing the oxygen content in the system and reducing the oxidation of high-density polyethylene during the chlorination process. This can effectively improve the heat resistance stability of chlorinated polyethylene products and meet the high-temperature processing requirements of polyester materials. Detailed Implementation

[0026] Typical embodiments embodying the features and advantages of the technical solutions of this application will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments, all of which do not depart from the scope of this application, and the description herein is for illustrative purposes only and not intended to limit the present invention.

[0027] In this application, the terms "parts" and "%" used to indicate content are by weight, unless otherwise specified. It is particularly important to understand that the invention is not limited to these examples.

[0028] In a first aspect, this application provides a toughening modifier for polyester, prepared from a raw material comprising the following components in parts by weight:

[0029]

[0030] The chlorinated polyethylene has a chlorine content of 8-25 wt%, a glass transition temperature of <-20℃, and a residual crystallinity of 0 ≤ <15%.

[0031] The residual crystallinity was determined by the heat of fusion using the differential scanning calorimetry method according to national standard GB / T 19466.3-2004, and calculated by the following formula:

[0032] Residual crystallinity = Heat of melting of chlorinated polyethylene / Theoretical heat of melting of high-density polyethylene (HDPE) with 100% crystallinity;

[0033] The thermal decomposition temperature of the toughening modifier is >200℃.

[0034] Polyester materials are crystalline engineering plastics with high melting points, resulting in high processing temperatures. Common toughening modifiers cannot meet the requirements of these temperatures. While toughening modifiers, such as chlorinated polyethylene (CPE), offer significant cost advantages, traditional CPE products have a thermal decomposition temperature of only around 165°C, leading to easy decomposition at high temperatures, poor toughening effects, and even equipment corrosion. Clearly, traditional CPE products cannot meet the high processing temperature requirements of polyester materials; for example, PETG typically requires processing temperatures above 200°C. The inventors discovered that as the chlorine content in CPE products decreases, the product's heat resistance and stability improve, while the glass transition temperature decreases. A lower glass transition temperature provides better toughness, but as the chlorine content of CPE decreases, the residual crystallinity increases, leading to decreased compatibility with polyester materials and thus reduced modification effects. This application utilizes CPE materials with a good balance of glass transition temperature and residual crystallinity to obtain a toughening modifier with good toughening effects and high thermal stability, which can improve the processing and molding effects and impact toughness of polyester resins.

[0035] In a preferred embodiment, the thermal decomposition temperature of the toughening modifier is >245°C, at which point the chlorine content of the chlorinated polyethylene is 8-18 wt%.

[0036] In one embodiment, the compatibilizer is glycidyl methacrylate (GMA). By grafting GMA onto chlorinated polyethylene, the compatibility between the toughening modifier and the polyester material can be improved, achieving uniform dispersion in the polyester material. This enhances the compatibility between the toughening modifier and the polyester material without affecting the heat resistance stability of the toughening modifier, promotes the dispersion of the toughening modifier in the polyester material, and fully utilizes its toughening modification effect.

[0037] In one embodiment, the initiator is selected from one or more of dicumyl peroxide (DCP), bis-tert-butyl peroxide (BIBP), benzoyl peroxide (BPO), and dicumyl hydroperoxide (DIP). By selecting a preferred initiator, the grafting rate can be appropriately improved.

[0038] In one embodiment, the filler is selected from one or more of calcium carbonate, talc, titanium dioxide, calcium oxide, and silicon dioxide. Adding a filler, preferably an inorganic filler, can prevent the toughening modifier from sticking together, facilitating the subsequent mixing and processing of the toughening modifier and polyester material, and improving the uniformity of the mixture.

[0039] In one embodiment, the stabilizer is one or more selected from organotin stabilizers, calcium-zinc composite stabilizers, lead salt composite stabilizers, hydrotalcite, and zeolite. This application, by adding a stabilizer component to the toughening modifier, can further improve the thermal stability of the toughening modifier, meeting the higher processing temperature requirements of polyester materials.

[0040] In a second aspect, the present invention also provides a method for preparing the above-mentioned toughening modifier, comprising the following steps:

[0041] Step 1): Add 0.05-0.5 parts by weight of dispersant and 0.005-0.06 parts by weight of emulsifier to the reactor, then add water to make the total weight of the dispersant, emulsifier and water 150 parts by weight. Then add 20-30 parts by weight of high-density polyethylene. Inert gas is introduced from the bottom of the reactor to remove oxygen from the reaction liquid and the gas phase at the top of the reactor. The reaction material is heated to 80-105°C with stirring. 3.5-20 parts by weight of chlorine gas is introduced at the beginning, while the temperature is slowly increased to 120-140°C. After the chlorine gas is introduced, the mixture is cooled to below 100°C, deacidified, neutralized, washed with water, centrifuged and dried to obtain chlorinated polyethylene with a chlorine content of 8-25 wt%, a glass transition temperature of <-20°C and 0 ≤ residual crystallinity <15%.

[0042] Step 2): Weigh 85.0-97.2 parts by weight of chlorinated polyethylene, 0.8-5.0 parts by weight of compatibilizer, 0.01-0.2 parts by weight of initiator, 0.5-6.0 parts by weight of filler, and 0.5-4.0 parts by weight of stabilizer, put them into a mixer and stir for 2-5 minutes, then discharge them for later use.

[0043] Step 3): The mixed material is extruded and granulated by a twin-screw extruder to obtain the toughening modifier.

[0044] In the preparation process of chlorinated polyethylene, this application improves the uniformity of chlorination by increasing the initial chlorination temperature, reduces the glass transition temperature of the material, and decreases residual crystallinity, thereby enhancing the toughening effect of the toughening modifier. The inventors also discovered that during the preparation of chlorinated polyethylene, when the chlorination reaction temperature is above 100°C, oxygen in the reactor oxidizes the chlorinated polyethylene material, reducing its heat resistance. As the oxygen content in the reactor decreases, the heat resistance of the chlorinated polyethylene material increases. This application reduces the oxygen content in the system by injecting inert gas into the reactor, continuously replacing the oxygen in the reaction liquid and the upper gas phase on the surface of the liquid, thereby reducing the oxidation of high-density polyethylene during the chlorination process, improving the heat resistance of chlorinated polyethylene products, and meeting the high-temperature processing requirements of polyester materials.

[0045] In one embodiment, the inert gas is nitrogen or an inert gas, preferably nitrogen.

[0046] In this application, the dispersants and emulsifiers mentioned can all be conventional reagents in the art, without any particular limitation. For example, the dispersants used may include water-soluble alkyl acrylate polymeric dispersants, alkyl maleate (ester) polymeric dispersants, etc., wherein the alkyl group is preferably C1-C. 12 Alkyl groups, C1-C5 alkyl groups, and C1-C3 alkyl groups. Examples include sodium (meth)acrylate-methyl methacrylate copolymer and sodium maleate-methyl methacrylate copolymer. The emulsifier used is, for example, a nonionic emulsifier, including, for example, polyol esters or alkylphenol polyoxyethylene ethers. For example, the emulsifier used may include polyoxyethylene dodecyl ether, fatty alcohol polyoxyethylene ether, nonylphenol polyoxyethylene ether, etc.

[0047] In this invention, there is no particular limitation on the lower limit of the glass transition temperature of the chlorinated polyethylene. In some embodiments, for example, the glass transition temperature of the chlorinated polyethylene may be greater than -200°C, or greater than -100°C, or greater than -60°C, etc.

[0048] In a preferred embodiment, in step 3), the temperatures of each section of the twin-screw extruder are set as follows: barrel temperature 85–130°C, spool temperature 80–100°C, and die temperature 85–110°C.

[0049] In a third aspect, the present invention also provides a modified polyester, which is a polyester modified by the toughening modifier described above.

[0050] In one embodiment, the modified polyester is prepared from a raw material comprising the following components in parts by weight: 100 parts by weight of the polyester, 5 to 12 parts by weight of the toughening modifier, and 75 to 150 parts by weight of filler. In this invention, the toughening modifier is as described above.

[0051] In one embodiment, the filler is selected from one or more of calcium carbonate, talc, titanium dioxide, calcium oxide, and silicon dioxide. In some embodiments, the filler and the filler material may be the same or different.

[0052] In this invention, there are no particular limitations on the polyester used; any commonly used polyester may be used. For example, the polyester used may include polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene terephthalate-1,4-cyclohexanediol (PETG), polyethylene 2,6-naphthalate (PEN), polypropylene terephthalate (PTT), and other materials.

[0053] In a fourth aspect, the present invention also provides a method for preparing the modified polyester, the method comprising the following steps: weighing 100 parts by weight of the polyester, 5 to 12 parts by weight of the toughening modifier, and 75 to 150 parts by weight of the inorganic filler, stirring and mixing them evenly, and extruding them through a twin-screw extruder.

[0054] In one embodiment, the barrel temperature of the twin-screw extruder is 180–265°C, and the die temperature is 195–260°C.

[0055] In this application, to prevent the toughening modifier used for toughening modification during polyester material processing from undergoing thermal decomposition, the thermal decomposition temperature of the toughening modifier is higher than the processing temperature of the polyester. For example, when the polyester material is processed in a twin-screw extruder, the processing temperature covers the extrusion temperature of the polyester, and in this case, the thermal decomposition temperature of the toughening modifier must be higher than the extrusion temperature.

[0056] Furthermore, since different polyesters may have the same or different processing temperatures, a suitable toughening modifier can be selected based on the polyester to prevent thermal decomposition of the toughening modifier during polyester material processing. For example, when the polyester is PETG, the thermal decomposition temperature of the toughening modifier is preferably >200°C; when the polyester is PET, the thermal decomposition temperature of the toughening modifier is preferably >245°C.

[0057] The present application will be further described below with reference to the embodiments.

[0058] <Source of Raw Materials>

[0059] PET: China Resources Chemical Materials Technology Co., Ltd. (CR8816)

[0060] PETG: China Resources Chemical Materials Technology Co., Ltd. (CR5511)

[0061] High-density polyethylene: Nanjing Yangzi Petrochemical Co., Ltd. (2080)

[0062] DCP: Anhui Hengqi New Materials Co., Ltd.

[0063] BIBP: Wuhan Kangqiong Biomedical Technology Co., Ltd.

[0064] Glycidyl methacrylate: Guangzhou Sanwang Chemical Materials Co., Ltd.

[0065] Calcium carbonate: Qingzhou Yuxin Calcium Industry Co., Ltd. (Light calcium carbonate, 1250 mesh)

[0066] Calcium-zinc stabilizer: Jiangsu Lianmeng Chemical Co., Ltd. (IF-S8003-4)

[0067] Organotin stabilizer: Suzhou Branch of Yunnan Tin Industry Tin Chemical Materials Co., Ltd. (TY-181)

[0068] Hydrotalcite: Tianjin Jinheng Blue Ocean Technology Co., Ltd.

[0069] methyl methacrylate / acrylic acid copolymer: Shandong Rike Chemical Co., Ltd. (HL-FS)

[0070] Polyethylene dodecyl ether: Sanjiang Chemical Co., Ltd.

[0071] <Testing Methods>

[0072] Glass transition temperature: Differential scanning calorimetry according to national standard GB / T 19466.2-2004.

[0073] Residual crystallinity: The heat of fusion was determined by differential scanning calorimetry according to national standard GB / T 19466.3-2004, and the residual crystallinity was calculated according to the following formula:

[0074] Residual crystallinity = heat of fusion of chlorinated polyethylene / theoretical heat of fusion of HDPE with 100% crystallinity; the unit of heat of fusion is kJ / kg.

[0075] Impact strength: Refer to national standard GB / T 1043.1-2008.

[0076] Chlorine content: Refer to Method B of the national standard GB / T 7139-2002, the combustion flask method.

[0077] Thermal decomposition temperature: Turn on the constant temperature oil bath and stirrer, and heat to 80℃ and maintain the temperature. Fill the glass test tube to the 10ml mark with the sample. Roll up the Congo red test paper and place it into the glass test tube, along with the rubber stopper, into a cuvette. Place the cuvette into the constant temperature oil bath. Increase the temperature at a rate of 2℃ per minute and record the temperature at which the Congo red test paper changes color.

[0078] The reaction conversion rate is calculated as (weight of generated chlorinated polyethylene powder / weight of feed reactant) × 100%; when chlorine is a reactant, the amount of chlorine is calculated as half of the actual amount added.

[0079] Extruder specifications: Parallel twin screw: screw diameter = 114mm, length-to-diameter ratio (L / D) = 28, main machine speed = 50 rpm.

[0080] Example 1

[0081] Add 0.05 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant and 0.005 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier to a reactor equipped with a stirrer. Then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Add 20 parts by weight of high-density polyethylene. Start stirring and heating. Purge nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 105°C with stirring, start purging 3.5 parts by weight of chlorine gas at a rate of 0.05 parts by weight / min. Then heat to 120°C while purging chlorine gas, with heating and chlorine purging occurring simultaneously. After chlorine purging is complete, cool to 95°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (denoted as chlorinated polyethylene powder 1) with a chlorine content of 8.0 wt%, a glass transition temperature of -44.6℃, a residual crystallinity of 13.8%, and a thermal decomposition temperature of 274℃ was obtained.

[0082] Preparation of toughening modifier:

[0083] A toughening modifier was prepared using chlorinated polyethylene powder 1, with the following specific proportions: chlorinated polyethylene powder 1: 93.8 parts by weight; glycidyl methacrylate: 5.0 parts by weight; dicumyl peroxide: 0.2 parts by weight; light calcium carbonate: 0.5 parts by weight; organotin stabilizer: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0084] Add the weighed materials to the mixing equipment in the following order: chlorinated polyethylene powder, glycidyl methacrylate, dicumyl peroxide, stabilizer, and light calcium carbonate. Start the mixer and mix at room temperature for 3 minutes. Discharge the material and set aside.

[0085] The mixed materials are extruded and granulated in a parallel twin-screw extruder. The specific extrusion granulation process conditions are shown in Table 1.

[0086] Table 1: Extrusion Granulation Process Conditions

[0087]

[0088]

[0089] The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 1, and the thermal decomposition temperature was measured to be 286℃.

[0090] Example 2

[0091] Add 0.45 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant and 0.05 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier to a reactor equipped with a stirrer. Then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Add 30 parts by weight of high-density polyethylene, start stirring and heating, and introduce nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 90°C with stirring, start introducing 20 parts by weight of chlorine gas at a rate of 0.1 parts by weight / min. Then heat to 136°C while introducing chlorine gas, with heating and chlorine introduction occurring simultaneously. After chlorine introduction is complete, cool to 98°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 2) with a chlorine content of 25.0 wt%, a glass transition temperature of -21.2℃, a residual crystallinity of 2.2%, and a thermal decomposition temperature of 198℃ was obtained.

[0092] Preparation of toughening modifier:

[0093] A toughening modifier was prepared using chlorinated polyethylene powder 2, with the following specific proportions: chlorinated polyethylene powder 2: 93.488 parts by weight; glycidyl methacrylate: 1.0 part by weight; di-tert-butyl peroxide: 0.012 parts by weight; silica: 5.0 parts by weight; and hydrotalcite: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0094] The extrusion process is followed as described in Example 1.

[0095] The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 2, and the thermal decomposition temperature was measured to be 204℃.

[0096] Example 3

[0097] Add 0.26 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant to a reactor equipped with a stirrer, add 0.03 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier, and then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Then add 24 parts by weight of high-density polyethylene, start stirring and heating, and introduce nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 96°C with stirring, start introducing 10 parts by weight of chlorine gas at a rate of 0.08 parts by weight / min. Then heat to 132°C while introducing chlorine gas, and heat introduction and chlorine introduction are carried out simultaneously. After the chlorine introduction is completed, cool to 95°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 3) with a chlorine content of 17.2 wt%, a glass transition temperature of -33.9℃, a residual crystallinity of 7.4%, and a thermal decomposition temperature of 257℃ was obtained.

[0098] Preparation of toughening modifier:

[0099] A toughening modifier was prepared using chlorinated polyethylene powder 3, with the following specific proportions: chlorinated polyethylene powder 3: 93.48 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.02 parts by weight; light calcium carbonate: 3.0 parts by weight; and hydrotalcite: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0100] The extrusion process is followed as described in Example 1.

[0101] The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 3, and the thermal decomposition temperature was measured to be 264℃.

[0102] Comparative Example 1

[0103] Add 0.28 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant to a reactor equipped with a stirrer, add 0.062 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier, and then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Then add 30 parts by weight of high-density polyethylene, start stirring and heating, and introduce nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 80°C with stirring, start introducing 32.3 parts by weight of chlorine gas at a rate of 0.2 parts by weight / min. Then heat to 132°C while introducing chlorine gas, and the heating and chlorine introduction are carried out simultaneously. After the chlorine introduction is completed, cool to 100°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 4) with a chlorine content of 35.0 wt%, a glass transition temperature of -9.4℃, a residual crystallinity of 0.2%, and a thermal decomposition temperature of 170℃ was obtained.

[0104] Preparation of toughening modifier:

[0105] A toughening modifier was prepared using chlorinated polyethylene powder 4, with the following specific proportions: chlorinated polyethylene powder 4: 93.48 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.02 parts by weight; light calcium carbonate: 3.0 parts by weight; and hydrotalcite: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0106] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 4, and the thermal decomposition temperature was measured to be 174°C.

[0107] Comparative Example 2

[0108] Add 0.45 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant and 0.05 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier to a reactor equipped with a stirrer. Then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Add 30 parts by weight of high-density polyethylene. Start stirring and heating. After heating to 90°C with stirring, start introducing 20 parts by weight of chlorine gas at a rate of 0.1 parts by weight / min. Then heat to 136°C while introducing chlorine gas, and heat introduction and chlorine introduction are carried out simultaneously. After chlorine introduction is completed, cool to 98°C. Filter the acidic water of the obtained reaction product through a filter bag to remove acid, neutralize, wash with water, centrifuge, and dry to obtain chlorinated polyethylene powder (chlorinated polyethylene powder 5) with a chlorine content of 25.0 wt%, a glass transition temperature of -21.0°C, a residual crystallinity of 2.1%, and a thermal decomposition temperature of 187°C.

[0109] Preparation of toughening modifier:

[0110] A toughening modifier was prepared using chlorinated polyethylene powder 5, with the following specific proportions: chlorinated polyethylene powder 5: 93.488 parts by weight; glycidyl methacrylate: 1.0 part by weight; dicumyl peroxide: 0.012 parts by weight; light calcium carbonate: 5.0 parts by weight; and hydrotalcite: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0111] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 5, and the thermal decomposition temperature was measured to be 193°C.

[0112] The thermal decomposition temperatures of the toughening modifiers prepared in Examples 1-3 and Comparative Examples 1-2 were compared. It was found that the thermal decomposition temperature of the product increased with decreasing chlorine content. Furthermore, in the preparation process of chlorinated polyethylene, replacing the oxygen in the reaction vessel with nitrogen gas improved thermal stability. As shown in the examples and comparative examples, during the preparation of the toughening modifier, the thermal decomposition temperature of the chlorinated polyethylene powder increased under the action of the stabilizer, indicating a certain degree of improvement in stability.

[0113] The toughening modifiers prepared in Examples 1-3 and Comparative Examples 1-2 were applied to specific polyester materials, and their toughening and modification effects on the polyester materials were compared in Table 2.

[0114] Table 2: Performance Tests of Toughening Modifier Samples 1-5

[0115]

[0116]

[0117] The comparison revealed that, compared with polyester materials without any toughening modifiers, the addition of toughening modifiers affected the impact performance of polyester materials. Toughening modifiers with a thermal decomposition temperature above 200℃ significantly improved the impact performance of polyester materials, with an improvement of over 100%. However, toughening modifiers with a thermal decomposition temperature below the processing temperature of polyester materials did not improve the impact performance of polyester materials and may even have reduced it.

[0118] According to the comparison of the thermal decomposition temperature data of toughening modifiers, the thermal decomposition temperature of toughening modifiers gradually decreases with the increase of chlorine content. In addition, reducing the oxygen content in the reactor and using stabilizer materials for modification can also help improve thermal stability.

[0119] Example 4

[0120] Add 0.08 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant to a reactor equipped with a stirrer, add 0.01 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier, and then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Then add 22 parts by weight of high-density polyethylene, start stirring and heating, and introduce nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 102°C with stirring, start introducing 6 parts by weight of chlorine gas at a rate of 0.06 parts by weight / min. Then heat to 130°C while introducing chlorine gas, and heat introduction and chlorine introduction are carried out simultaneously. After the chlorine introduction is completed, cool to 98°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 6) with a chlorine content of 12.0 wt%, a glass transition temperature of -40.8℃, a residual crystallinity of 12.3%, and a thermal decomposition temperature of 268℃ was obtained.

[0121] Preparation of toughening modifier:

[0122] A toughening modifier was prepared using chlorinated polyethylene powder 6, with the following specific proportions: chlorinated polyethylene powder 6: 94.49 parts by weight; glycidyl methacrylate: 1.5 parts by weight; dicumyl peroxide: 0.01 parts by weight; talc: 3.0 parts by weight; and hydrotalcite: 1.0 parts by weight. The proportions were weighed according to the above ratio.

[0123] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 6, and the thermal decomposition temperature was measured to be 273°C.

[0124] Example 5

[0125] Using the chlorinated polyethylene powder 6 obtained in Example 4, a toughening modifier was prepared with the following specific proportions: chlorinated polyethylene powder 6: 92.98 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.02 parts by weight; talc: 3.0 parts by weight; hydrotalcite: 1.0 parts by weight. The proportions were weighed according to the above ratio.

[0126] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 7, and the thermal decomposition temperature was measured to be 275°C.

[0127] Example 6

[0128] Using the chlorinated polyethylene powder 6 obtained in Example 4, a toughening modifier was prepared with the following specific proportions: chlorinated polyethylene powder 6: 91.47 parts by weight; glycidyl methacrylate: 4.5 parts by weight; dicumyl peroxide: 0.03 parts by weight; talc: 3.0 parts by weight; and hydrotalcite: 1.0 parts by weight. The proportions were weighed according to the above ratio.

[0129] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 8, which was found to have a thermal decomposition temperature of 274°C.

[0130] Example 7

[0131] Add 0.1 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant and 0.015 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier to a reactor equipped with a stirrer. Then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Add 27.5 parts by weight of high-density polyethylene. Start stirring and heating. Purge nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 90°C with stirring, start purging 9.7 parts by weight of chlorine gas at a rate of 0.075 parts by weight / min. Then heat to 134°C while purging chlorine gas, with heating and chlorine purging occurring simultaneously. After chlorine purging is complete, cool to 95°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 7) with a chlorine content of 15.0 wt%, a glass transition temperature of -35.0℃, a residual crystallinity of 9.7%, and a thermal decomposition temperature of 264℃ was obtained.

[0132] Preparation of toughening modifier:

[0133] A toughening modifier was prepared using chlorinated polyethylene powder 7, with the following specific proportions: chlorinated polyethylene powder 7: 91.576 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.024 parts by weight; calcium oxide: 1.5 parts by weight; and calcium-zinc stabilizer: 4.0 parts by weight. The proportions were weighed according to the above ratio.

[0134] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 9, and the thermal decomposition temperature was measured to be 272°C.

[0135] Comparative Example 3

[0136] Add 0.05 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant and 0.005 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier to a reactor equipped with a stirrer. Then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Add 20 parts by weight of high-density polyethylene. Start stirring and heating. Purge nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 80°C with stirring, start purging 3.5 parts by weight of chlorine gas at a rate of 0.05 parts by weight / min. Then heat to 115°C while purging chlorine gas, with heating and chlorine purging occurring simultaneously. After chlorine purging is complete, cool to 98°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 8) with a chlorine content of 8.0 wt%, a glass transition temperature of -46.6℃, a residual crystallinity of 22.4%, and a thermal decomposition temperature of 271℃ was obtained.

[0137] Preparation of toughening modifier:

[0138] A toughening modifier was prepared using chlorinated polyethylene powder 8, with the following specific proportions: chlorinated polyethylene powder 8: 93.8 parts by weight; glycidyl methacrylate: 5.0 parts by weight; dicumyl peroxide: 0.2 parts by weight; light calcium carbonate: 0.5 parts by weight; organotin stabilizer: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0139] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 10, and the thermal decomposition temperature was measured to be 273°C.

[0140] Comparative Example 4

[0141] Preparation of toughening modifier:

[0142] A toughening modifier was prepared using chlorinated polyethylene powder 1, with the following specific proportions: chlorinated polyethylene powder 1: 99.0 parts by weight; light calcium carbonate: 0.5 parts by weight; organotin stabilizer: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0143] The material was processed according to the extrusion process of Example 1. The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 11, and the thermal decomposition temperature was measured to be 284°C.

[0144] Comparative Example 5

[0145] Add 0.045 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant to a reactor equipped with a stirrer, add 0.005 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier, and then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Then add 20 parts by weight of high-density polyethylene, start stirring and heating, and introduce nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 108°C with stirring, start introducing 3 parts by weight of chlorine gas at a rate of 0.05 parts by weight / min. Then heat to 130°C while introducing chlorine gas, and heat introduction and chlorine introduction are carried out simultaneously. After the chlorine introduction is completed, cool to 98°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 9) with a chlorine content of 7.0 wt%, a glass transition temperature of -48.6℃, a residual crystallinity of 30.4%, and a thermal decomposition temperature of 279℃ was obtained.

[0146] Preparation of toughening modifier:

[0147] A toughening modifier was prepared using chlorinated polyethylene powder 9, with the following specific proportions: chlorinated polyethylene powder 9: 93.8 parts by weight; glycidyl methacrylate: 5.0 parts by weight; dicumyl peroxide: 0.2 parts by weight; light calcium carbonate: 0.5 parts by weight; organotin stabilizer: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0148] The material was processed using the extrusion process described in Example 1. The extruded material was pelletized using a pelletizer to obtain toughening modifier sample 12, and the thermal decomposition temperature was measured to be 292°C.

[0149] The toughening modifiers prepared in Examples 1 and 4-7 and the toughening modifiers prepared in Comparative Examples 3-5 were applied to specific polyester materials, and their toughening modification effects on polyester materials were compared in Table 3.

[0150] Table 3: Performance Tests of Toughening Modifier Samples No. 1, 6-12

[0151]

[0152]

[0153] Analysis of the test data revealed that, comparing samples 2-1#, 2-6#, and 2-8#, the impact strength of the toughening modifier-modified polyester material gradually decreased with increasing residual crystallinity. However, comparing the test results of samples 2-2#, 2-3#, and 2-4#, as well as 2-1# and 2-7#, showed that the impact strength of the toughening modifier-modified polyester material gradually increased with increasing grafted glycidyl methacrylate content. Based on these data, it can be inferred that polyethylene, being a non-polar material, has poor compatibility with polyester materials. Chlorination or grafting with glycidyl methacrylate can improve the compatibility of chlorinated polyethylene with polyester resin, thereby enhancing its toughening effect.

[0154] Example 8

[0155] Add 0.3 parts by weight of water-soluble methyl methacrylate / acrylic acid copolymer as a dispersant and 0.036 parts by weight of polyvinyl oxide dodecyl ether as an emulsifier to a reactor equipped with a stirrer. Then add an appropriate amount of water to make the total amount of dispersant, emulsifier, and water 150 parts by weight. Add 27.5 parts by weight of high-density polyethylene. Start stirring and heating. Purge nitrogen gas from the bottom of the reactor for 20 minutes. After heating to 94°C with stirring, start purging 13.75 parts by weight of chlorine gas at a rate of 0.08 parts by weight / min. Then heat to 135°C while purging chlorine gas, with heating and chlorine purging occurring simultaneously. After chlorine purging is complete, cool to 96°C. The acidic water from the resulting reactants was filtered out using a filter bag for deacidification. After neutralization, washing, centrifugation, and drying, chlorinated polyethylene powder (chlorinated polyethylene powder 10) with a chlorine content of 20.0 wt%, a glass transition temperature of -28.0℃, a residual crystallinity of 4.6%, and a thermal decomposition temperature of 230℃ was obtained.

[0156] Preparation of toughening modifier:

[0157] A toughening modifier was prepared using chlorinated polyethylene powder 10, with the following specific proportions: chlorinated polyethylene powder 10: 93.48 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.02 parts by weight; light calcium carbonate: 3.0 parts by weight; zeolite: 0.5 parts by weight. The quantities were weighed according to the above proportions.

[0158] The material was processed according to the extrusion process of Example 1. The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 13, and the thermal decomposition temperature was measured to be 241°C.

[0159] Example 9

[0160] A toughening modifier was prepared using chlorinated polyethylene powder 1, with the following specific proportions: chlorinated polyethylene powder 1: 93.48 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.02 parts by weight; talc: 3.0 parts by weight; hydrotalcite: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0161] The material was processed according to the extrusion process of Example 1. The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 14, and the thermal decomposition temperature was measured to be 284°C.

[0162] Example 10

[0163] A toughening modifier was prepared using chlorinated polyethylene powder 3, with the following specific proportions: chlorinated polyethylene powder 1: 93.48 parts by weight; glycidyl methacrylate: 3.0 parts by weight; dicumyl peroxide: 0.02 parts by weight; talc: 3.0 parts by weight; hydrotalcite: 0.5 parts by weight. The proportions were weighed according to the above ratio.

[0164] The material was processed according to the extrusion process of Example 1. The extruded material was pelletized by a pelletizer to obtain toughening modifier sample 15, and the thermal decomposition temperature was measured to be 205°C.

[0165] The relationship between the chlorine content of different chlorinated polyethylene powders and their glass transition temperature is shown in Table 4.

[0166] Table 4: Relationship between chlorine content and glass transition temperature of different chlorinated polyethylene powders

[0167]

[0168]

[0169] The above toughening modifiers were added to polyester materials, and the differences in impact performance were compared. See Table 5 for details.

[0170] Table 5: Performance Tests of Toughening Modifier Samples with Different Chlorine Content

[0171]

[0172]

[0173] Analysis of the data in Tables 4 and 5 shows that as the chlorine content increases, the residual crystallinity of chlorinated polyethylene gradually decreases, while the glass transition temperature gradually increases. Analysis of the data in Table 3 indicates that, at the same chlorine content, a decrease in residual crystallinity is beneficial for improving impact performance. In Table 5, the impact strength of the polyester material modified with the toughening modifier shows a trend of first increasing and then decreasing, presumably a result of the combined effect of the residual crystallinity and glass transition temperature of the toughening modifier. That is, a lower glass transition temperature is beneficial for the toughening modifier to impart good impact performance to the polyester material, but a lower residual crystallinity is also beneficial. The toughening modifier needs to simultaneously control both the residual crystallinity and the glass transition temperature parameters.

Claims

1. A toughening modifier for polyester, characterized in that, It is prepared from raw materials comprising the following components in parts by weight: The chlorinated polyethylene has a chlorine content of 8-25 wt%, a glass transition temperature of <-20℃, and a residual crystallinity of 0 ≤ <15%. The residual crystallinity was determined by the heat of fusion using the differential scanning calorimetry method according to national standard GB / T 19466.3-2004, and calculated by the following formula: Residual crystallinity = Heat of melt of chlorinated polyethylene / Theoretical heat of melt of HDPE with 100% crystallinity; The thermal decomposition temperature of the toughening modifier is >200℃; The compatibilizer is glycidyl methacrylate; In the preparation of chlorinated polyethylene, after adding high-density polyethylene and before introducing chlorine gas, an inert gas is introduced from the bottom of the reactor to remove oxygen from the reaction liquid and the gas phase at the top of the reactor.

2. The toughening modifier according to claim 1, characterized in that, The chlorine content of the chlorinated polyethylene is 8-18 wt%, and the thermal decomposition temperature of the toughening modifier is >245℃.

3. The toughening modifier according to claim 1 or 2, characterized in that, The initiator is selected from one or more of dicumyl peroxide, bis-tert-butyl peroxide, benzoyl peroxide, and dicumyl hydroperoxide.

4. The toughening modifier according to claim 1 or 2, characterized in that, The filler is selected from one or more of calcium carbonate, talc, titanium dioxide, calcium oxide, and silicon dioxide.

5. The toughening modifier according to claim 1 or 2, characterized in that, The stabilizer is one or more of the following: organotin stabilizer, calcium-zinc composite stabilizer, lead salt composite stabilizer, hydrotalcite, and zeolite.

6. A method for preparing a toughening modifier according to any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1): Add 0.05-0.5 parts by weight of dispersant and 0.005-0.06 parts by weight of emulsifier to the reactor, then add water to make the total weight of the dispersant, emulsifier and water 150 parts by weight. Then add 20-30 parts by weight of high-density polyethylene. Inert gas is introduced from the bottom of the reactor to remove oxygen from the reaction liquid and the gas phase at the top of the reactor. The reaction material is heated to 80-105°C with stirring. 3.5-20 parts by weight of chlorine gas is introduced at the same time and the temperature is raised to 120-140°C. After the chlorine gas is introduced, the mixture is cooled to below 100°C, deacidified, neutralized, washed with water, centrifuged and dried to obtain chlorinated polyethylene with a chlorine content of 8-25 wt%, a glass transition temperature of <-20°C and 0 ≤ residual crystallinity <15%. Step 2): Weigh 85.0-97.2 parts by weight of the chlorinated polyethylene, 0.8-5.0 parts by weight of the compatibilizer, 0.01-0.2 parts by weight of the initiator, 0.5-6.0 parts by weight of the filler, and 0.5-4.0 parts by weight of the stabilizer, put them into a mixer and stir for 2-5 minutes, then discharge them for later use. Step 3): The mixed material is extruded and granulated by a twin-screw extruder to obtain the toughening modifier.

7. The method according to claim 6, characterized in that, The inert gas is nitrogen or an inert gas.

8. The method according to claim 7, characterized in that, The inert gas is nitrogen.

9. The method according to claim 6, characterized in that, In step 3), the temperatures of each section of the twin-screw extruder are set as follows: barrel temperature 85-130℃, confluence core temperature 80-100℃, and die temperature 85-110℃.

10. A modified polyester, characterized in that, The modified polyester is a polyester modified with a toughening modifier prepared using any one of the toughening modifiers as described in claims 1 to 5 or the method described in any one of claims 6 to 9.

11. The modified polyester according to claim 10, characterized in that, The modified polyester is obtained from a raw material comprising the following components in parts by weight: 100 parts by weight of polyester; The toughening modifier is 5-12 parts by weight; 75-150 parts by weight of filler; The filler is selected from one or more of calcium carbonate, talc, titanium dioxide, calcium oxide, and silicon dioxide.

12. The modified polyester according to claim 11, characterized in that, The polyester is selected from one or more of polyethylene terephthalate, polybutylene terephthalate, polyethylene terephthalate-1,4-cyclohexanediol ester, polyethylene 2,6-naphthalate, and polypropylene terephthalate.

13. A method for preparing the modified polyester according to any one of claims 10 to 12, characterized in that, The method includes the following steps: weighing 100 parts by weight of the polyester, 5 to 12 parts by weight of the toughening modifier, and 75 to 150 parts by weight of the filler, stirring and mixing them evenly, and then extruding them through a twin-screw extruder; The thermal decomposition temperature of the toughening modifier is higher than the extrusion temperature of the polyester.

14. The method according to claim 13, characterized in that, The thermal decomposition temperature of the toughening modifier is >200℃.

15. The method according to claim 13, characterized in that, The thermal decomposition temperature of the toughening modifier is >245℃.

16. The method according to any one of claims 13 to 15, characterized in that, The barrel temperature of the twin-screw extruder is 180–265°C, and the die temperature is 195–260°C.

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