Fluorine-free polymer processing aid and preparation method thereof

Abstract

The invention discloses a fluorine-free polymer processing aid and a preparation method thereof, and relates to the technical field of polymer processing aids, the fluorine-free polymer processing aid comprises the following components: polyethylene glycol or modified polyethylene glycol, silicone oil or modified silicone oil, and an antioxidant; the modification mode of the modified polyethylene glycol comprises the step of introducing alkyl, alkoxy, aromatic ring or unsaturated functional groups on the main chain of the polyethylene glycol through free radical polymerization; the modified silicone oil comprises hydroxylated modified silicone oil, amino modified silicone oil or polyether modified silicone oil. The fluorine-containing polymer processing aid solves the problem that a C-F bond in an existing fluorine-containing polymer processing aid is difficult to degrade in the environment and can cause long-term influence on human health and the environment, and meanwhile, the polymer processing aid can also effectively eliminate the phenomena of melt fracture and sharkskin, reduce material accumulation at a die orifice, improve the thickness uniformity of a film and improve the production efficiency of the film. And meanwhile, no negative influence is generated on physical and mechanical properties and other optical properties of products such as films, the production efficiency is improved, waste is reduced, and energy is saved.

Description

Technical Field

[0001] The invention relates to the technical field of polymer processing aids, and in particular to a fluorine-free polymer processing aid and a preparation method thereof. Background Art

[0002] Fluorinated processing aid PPA is widely used in the terminal granulation stage of polymer synthesis and in polymer molding processing to improve die buildup and melt fracture to improve production efficiency and product quality. PFAS, which has a similar structure to this fluorinated additive, is used in non-stick pans, firefighting foam, aerospace, electronic products, construction, food packaging, stain-resistant clothing / furniture and many other applications.

[0003] PFAS (Per-and Polyfluoroalkyl substrate) is a series of artificially synthesized compounds. The abnormal stability and strength of the CF bond also bring some disadvantages, namely, it is difficult to degrade in the environment, causing long-term impacts on human health and the environment. They have multiple toxicities such as genotoxicity, neurotoxicity, and thyroid toxicity, and accumulate in organisms, which also have adverse effects on wildlife in the ecosystem. In view of this, countries around the world have successively announced regulations to restrict or prohibit the use of PFAS, so the use of non-fluorinated processing aids PPA will definitely become an industry trend.

[0004] In the processing of various plastic products, such as film blowing, pipe extrusion, plastic particle granulation, etc., die buildup and melt fracture often occur due to the continuous friction between the plastic melt and the die head, thus affecting product quality and production efficiency. The currently widely used fluorinated PPA, also known as polymer processing aid, can improve die buildup, eliminate melt fracture and shark skin phenomenon, but due to the presence of CF bonds that are difficult to degrade in the environment, it will cause long-term impacts on human health and the environment. At the same time, due to the influence of relevant regulations, it will inevitably be gradually replaced. Summary of the invention

[0005] Based on the problem that the CF bonds existing in the current fluorine-containing polymer processing aids are difficult to degrade in the environment, which will cause long-term impacts on human health and the environment, the purpose of the present invention is to provide a fluorine-free polymer processing aid and a preparation method thereof. The polymer processing aid does not contain fluorine, which solves the problem that the CF bonds existing in the current fluorine-containing polymer processing aids are difficult to degrade in the environment, which will cause long-term impacts on human health and the environment. At the same time, the polymer processing aid can also effectively eliminate melt fracture and "shark skin" phenomenon, reduce die accumulation, and improve film thickness uniformity. At the same time, it has no negative impact on the physical and mechanical properties and other optical properties of products such as films, thereby improving production efficiency, reducing waste and saving energy.

[0006] The present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a fluorine-free polymer processing aid, comprising the following components: polyethylene glycol or modified polyethylene glycol, silicone oil or modified silicone oil, and an antioxidant;

[0008] The modification method of the modified polyethylene glycol includes introducing an alkyl group, an alkoxy group, an aromatic ring or an unsaturated functional group into the main chain of the polyethylene glycol by free radical polymerization;

[0009] The modified silicone oil includes hydroxylated modified silicone oil, amino modified silicone oil or polyether modified silicone oil.

[0010] The invention introduces alkyl, alkoxy, aromatic ring or unsaturated functional group into the main chain of polyethylene glycol, so that the prepared processing aid has certain flexibility, plays a role of plasticization, and reduces the viscosity of plastic melt, so that plastic is easier to flow and fill the mold during the molding process, and improves the molding quality and production efficiency of plastic products. Silicone oil helps defoaming and demoulding, and can also improve the high temperature resistance and oxidation resistance of the processing aid. After the modified polyethylene glycol is mixed with silicone oil or modified silicone oil, it can be quickly dispersed to the melt and metal surface while lubricating, and is resistant to continuous high temperature and oxidation, and continuously improves the stable lubrication effect. The polymer processing aid prepared by mixing the modified polyethylene glycol with silicone oil in the present application can effectively eliminate melt fracture, "shark skin" phenomenon, reduce die mouth material accumulation, and improve film thickness uniformity. The added antioxidant can prevent the processing aid from thermal oxidation degradation during use, so that its molding process can be carried out smoothly, maintain the excellent performance of the material, and extend the service life.

[0011] The hydroxylated modified silicone oil, amino modified silicone oil and polyether modified silicone oil in the present invention have low surface tension, which can effectively reduce the surface tension of the system, so that the prepared polymer processing aid has good wettability and fluidity, so that it can be better distributed on the surface of the substrate, and can also effectively control the generation of foam, prevent production problems caused by excessive foam, and also have the effect of improving lubricity. After effective experimental verification, the polymer processing aid prepared by combining it with polyethylene glycol or modified polyethylene glycol can also effectively eliminate melt fracture, "shark skin" phenomenon, reduce die buildup, and improve film thickness uniformity.

[0012] Among them, when preparing modified polyethylene glycol, the polyethylene glycol is first put into a reaction kettle and heated to 100°C to 120°C for vacuum dehydration until the water content is less than 0.05%. After cooling, an initiator (tert-butyl peroxyvalerate) is added, and after stirring evenly, a grafting monomer is gradually added dropwise through a high-level tank, and then reacted to obtain the modified polyethylene glycol.

[0013] The antioxidants include phenolic stabilizer (Clariant O3), organophosphorus complex (phosphite), antioxidant 1010, antioxidant 168, and antioxidant 1076.

[0014] Furthermore, when preparing the liquid fluorine-free polymer processing agent, a defoaming agent and a dispersant are also included.

[0015] The liquid fluorine-free polymer processing agent comprises, by weight: 10 to 90 parts of polyethylene glycol or modified polyethylene glycol, 10 to 90 parts of silicone oil or modified silicone oil, 1 to 3 parts of antioxidant, 0.05 to 1 part of defoaming agent, and 0.1 to 5 parts of dispersant.

[0016] Furthermore, the defoaming agent includes fatty acid (tetradecanoic acid), fatty alcohol (n-heptanol, n-octanol, n-nonanol, n-decanol) or fatty acid ester (propylene glycol fatty acid ester).

[0017] Furthermore, the dispersant includes fatty acids (lauric acid), fatty amides (stearamide, vinyl bisstearamide), ester compounds (monoglycerol stearate, glycerol tristearate), low molecular wax compounds (polyethylene wax) or metal soap compounds (zinc stearate, calcium stearate).

[0018] Furthermore, when preparing the solid fluorine-free polymer processing agent, linear low-density polyethylene and polyethylene wax are also included.

[0019] The solid fluorine-free polymer processing agent comprises, by weight: 0.6 to 10 parts of polyethylene glycol or modified polyethylene glycol, 0.6 to 10 parts of silicone oil or modified silicone oil, 1 to 3 parts of antioxidant, 86.4 to 88.4 parts of linear low-density polyethylene, and 1 to 3 parts of polyethylene wax.

[0020] Furthermore, the alkyl group includes methyl, ethyl, propyl or isopropyl.

[0021] Furthermore, the alkoxy group includes methoxy, ethoxy or propoxy.

[0022] Furthermore, the unsaturated functional groups include -CH2CH=CHCH3, -CH2OCH2C=CH2, -(CH2CH3)CH2OCH2C=CH2 or -(CH2CH3)(CH2OCH2C=CH2)2.

[0023] In a second aspect, the present application provides a method for preparing a fluorine-free polymer processing aid, comprising the following steps:

[0024] When preparing the liquid fluorine-free polymer processing aid, the raw materials are weighed according to the weight fraction, and the liquid fluorine-free polymer processing aid is obtained after stirring and mixing;

[0025] When preparing a solid fluorine-free polymer processing aid, raw materials are weighed according to weight fractions, stirred and mixed, and then put into a twin-screw extruder for melt blending. The melt-plasticized materials are cooled and pelletized to obtain a solid fluorine-free polymer processing aid.

[0026] Furthermore, when preparing a solid fluorine-free polymer processing aid, the temperatures of each zone of the twin-screw extruder are controlled as follows: zone 1 130°C ~ 140°C, zone 2 140°C ~ 180°C, zone 3 150°C ~ 180°C, zone 4 150°C ~ 180°C, zone 5 160°C ~ 190°C, zone 6 160°C ~ 190°C, zone 7 150°C ~ 180°C, and the head temperature is controlled at 150°C ~ 180°C.

[0027] Among them, the rotation speed of the feeding screw is 400rpm~600rpm, and the rotation speed of the main engine screw is 180rpm~350rpm.

[0028] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0029] (1) The polymer processing aid of the present invention does not contain fluorine, which solves the problem that the CF bonds in the current processing aids are difficult to degrade in the environment and will cause long-term impacts on human health and the environment.

[0030] (2) The polymer processing aid in the present invention can also effectively eliminate melt fracture and the "shark skin" phenomenon, reduce die buildup, and improve film thickness uniformity. At the same time, it has no negative impact on the physical and mechanical properties and other optical properties of the film and other products, thereby improving production efficiency, reducing waste and saving energy.

[0031] (3) After being added into the extruder, the liquid fluorine-free polymer processing aid of the present invention can quickly migrate to the metal surface and be adsorbed, thereby exerting its effect quickly and continuously. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. The illustrative embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0033] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is apparent to one of ordinary skill in the art that these specific details need not be employed to practice the present invention. In other embodiments, in order to avoid confusing the present invention, well-known materials or methods are not specifically described.

[0034] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment," "an embodiment," "an example," or "an example" that appear in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any appropriate combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. In addition, those skilled in the art will be able to combine and combine different embodiments or examples described in this specification and features of different embodiments or examples, without contradicting each other.

[0035] The "range" disclosed in the present application is defined in the form of a lower limit and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The range defined in this way can be inclusive or exclusive of the end values, and can be arbitrarily combined, that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0036] Example 1

[0037] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid, wherein the raw material formula is: 0.6 g of modified polyethylene glycol, 4 g of silicone oil, 1.2 g of antioxidant (phosphite), 87 g of linear low-density polyethylene, and 1.2 g of polyethylene wax. The specific preparation method is:

[0038] S1. Preparation of modified polyethylene glycol

[0039] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0040] S2. Preparation of fluorine-free polymer processing aids using modified polyethylene glycol

[0041] 0.6 g of modified polyethylene glycol, 4 g of silicone oil, 1.2 g of phosphite, 87 g of linear low-density polyethylene and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0042] Example 2

[0043] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that the modified polyethylene glycol in this embodiment is a modified polyethylene glycol containing an alkyl (ethyl) group. The other processes are the same as those in Example 1. The raw material formula is: 0.6g of modified polyethylene glycol, 4g of silicone oil, 1.2g of antioxidant (phosphite), 87g of linear low-density polyethylene, and 1.2g of polyethylene wax. The specific preparation method is:

[0044] S1. Preparation of modified polyethylene glycol

[0045] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethane) is gradually added dropwise through a high-level tank. After the reaction, modified polyethylene glycol containing ethyl groups is obtained.

[0046] S2. Preparation of fluorine-free polymer processing aids using modified polyethylene glycol

[0047] 0.6 g of modified polyethylene glycol, 4 g of silicone oil, 1.2 g of phosphite, 87 g of linear low-density polyethylene and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0048] Example 3

[0049] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that the modified polyethylene glycol in this embodiment is a modified polyethylene glycol containing an unsaturated functional group (-CH2CH=CHCH3). The other processes are the same as those in Example 1. The raw material formula is: 0.6g of modified polyethylene glycol, 4g of silicone oil, 1.2g of antioxidant (phosphite), 87g of linear low-density polyethylene, and 1.2g of polyethylene wax. The specific preparation method is:

[0050] S1. Preparation of modified polyethylene glycol

[0051] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (butene) is gradually added dropwise through a high-level tank. After the reaction, modified polyethylene glycol containing unsaturated functional groups (-CH2CH=CHCH3) is obtained.

[0052] S2. Preparation of fluorine-free polymer processing aids using modified polyethylene glycol

[0053] 0.6 g of modified polyethylene glycol, 4 g of silicone oil, 1.2 g of phosphite, 87 g of linear low-density polyethylene and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0054] Example 4

[0055] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that amino-modified silicone oil is used to replace silicone oil in this embodiment. The other processes are the same as those in Example 1. The raw material formula is: 0.6g of modified polyethylene glycol, 4g of amino-modified silicone oil, 1.2g of antioxidant (phosphite), 87g of linear low-density polyethylene, and 1.2g of polyethylene wax. The specific preparation method is:

[0056] S1. Preparation of modified polyethylene glycol

[0057] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0058] S2. Preparation of amino-modified silicone oil

[0059] Take 300g of dimethylsiloxane as the starting material, add 0.2g of tetramethylammonium hydroxide and 10g of aminosilane coupling agent (γ-aminopropyltriethoxysilane), mix evenly, heat to 60°C and keep warm for 100min, then perform vacuum degassing, then heat to 110°C, react for 3h, neutralize the catalyst, and finally perform vacuum degassing to obtain amino-modified silicone oil.

[0060] S3. Preparation of fluorine-free polymer processing aid using modified polyethylene glycol and amino-modified silicone oil

[0061] 0.6 g of modified polyethylene glycol, 4 g of amino-modified silicone oil, 1.2 g of phosphite, 87 g of linear low-density polyethylene and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0062] Example 5

[0063] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 4 is that polyethylene glycol is used to replace modified polyethylene glycol in this embodiment. The other processes are the same as those in Example 4. The raw material formula is: 0.6g polyethylene glycol, 4g amino-modified silicone oil, 1.2g antioxidant (phosphite), 87g linear low-density polyethylene, and 1.2g polyethylene wax. The specific preparation method is:

[0064] S1. Preparation of amino-modified silicone oil

[0065] Take 300g of dimethylsiloxane as the starting material, add 0.2g of tetramethylammonium hydroxide and 10g of aminosilane coupling agent (γ-aminopropyltriethoxysilane), mix evenly, heat to 60°C and keep warm for 100min, then perform vacuum degassing, then heat to 110°C, react for 3h, and finally perform vacuum degassing to obtain amino-modified silicone oil.

[0066] S2. Preparation of fluorine-free polymer processing aid using amino-modified silicone oil

[0067] 0.6 g of modified polyethylene glycol, 4 g of amino-modified silicone oil, 1.2 g of phosphite, 87 g of linear low-density polyethylene and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0068] Example 6

[0069] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that polyethylene glycol is used to replace modified polyethylene glycol in this embodiment. The raw material formula is: 0.6g polyethylene glycol, 4g silicone oil, 1.2g antioxidant (phosphite), 87g linear low-density polyethylene, and 1.2g polyethylene wax. The specific preparation method is:

[0070] 0.6 g of polyethylene glycol, 4 g of silicone oil, 1.2 g of phosphite, 87 g of linear low-density polyethylene and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: 130-140° C. for zone one, 140-180° C. for zone two, 150-180° C. for zone three, 150-180° C. for zone four, 160-190° C. for zone five, 160-190° C. for zone six, 150-180° C. for zone seven, a die head temperature of 150-180° C., a feeding screw speed of 400-600 rpm, a main engine screw speed of 180-350 rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0071] Example 7

[0072] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that the amount of raw materials used in this embodiment is different. The raw material formula is: 10g of modified polyethylene glycol, 0.6g of silicone oil, 1g of antioxidant (phosphite), 86.4g of linear low-density polyethylene, and 1g of polyethylene wax. The specific preparation method is:

[0073] S1. Preparation of modified polyethylene glycol

[0074] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0075] S2. Preparation of fluorine-free polymer processing aids using modified polyethylene glycol

[0076] 10g of modified polyethylene glycol, 0.6g of silicone oil, 1g of phosphite, 86.4g of linear low-density polyethylene and 1g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: 130-140°C for zone one, 140-180°C for zone two, 150-180°C for zone three, 150-180°C for zone four, 160-190°C for zone five, 160-190°C for zone six, 150-180°C for zone seven, the head temperature is 150-180°C, the feed screw speed is 400-600rpm, the main engine screw speed is 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0077] Example 8

[0078] This embodiment provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that the amount of raw materials used in this embodiment is different. The raw material formula is: 5g of modified polyethylene glycol, 10g of silicone oil, 3g of antioxidant (phosphite), 88.4g of linear low-density polyethylene, and 3g of polyethylene wax. The specific preparation method is:

[0079] S1. Preparation of modified polyethylene glycol

[0080] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0081] S2. Preparation of fluorine-free polymer processing aids using modified polyethylene glycol

[0082] 5 g of modified polyethylene glycol, 10 g of silicone oil, 3 g of phosphite, 88.4 g of linear low-density polyethylene and 3 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-free polymer processing aid PPA.

[0083] Example 9

[0084] This embodiment provides a method for preparing a liquid fluorine-free polymer processing aid PPA, the raw material formula of which is: 90g modified polyethylene glycol, 8g amino-modified silicone oil, 1.7g antioxidant (phosphite), 0.1g defoamer (tetradecanoic acid), 0.2g dispersant (lauric acid). The specific preparation method is:

[0085] S1. Preparation of modified polyethylene glycol

[0086] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0087] S2. Preparation of amino-modified silicone oil

[0088] Take 300g of dimethylsiloxane as the starting material, add 0.2g of tetramethylammonium hydroxide and 10g of aminosilane coupling agent (γ-aminopropyltriethoxysilane), mix evenly, heat to 60°C and keep warm for 100min, then perform vacuum degassing, then heat to 110°C, react for 3h, and finally perform vacuum degassing to obtain amino-modified silicone oil.

[0089] S3. Preparation of fluorine-free polymer processing aid using modified polyethylene glycol and amino-modified silicone oil

[0090] The mixture obtained by mixing 90 g of modified polyethylene glycol, 8 g of amino-modified silicone oil, 1.7 g of antioxidant (phosphite), 0.1 g of defoaming agent (tetradecanoic acid), and 0.2 g of dispersant (lauric acid) is the liquid fluorine-free polymer processing aid PPA.

[0091] Example 10

[0092] This embodiment provides a method for preparing a liquid fluorine-free polymer processing aid PPA. The difference from Example 9 is that polyethylene glycol is used to replace modified polyethylene glycol in this embodiment, and the raw material formula is: 90g polyethylene glycol, 8g modified silicone oil, 1.7g antioxidant (phosphite), 0.1g defoamer (tetradecanoic acid), 0.2g dispersant (lauric acid). The specific preparation method is:

[0093] S1. Preparation of amino-modified silicone oil

[0094] Take 300g of dimethylsiloxane as the starting material, add 0.2g of tetramethylammonium hydroxide and 10g of aminosilane coupling agent (γ-aminopropyltriethoxysilane), mix evenly, heat to 60°C and keep warm for 100min, then perform vacuum degassing, then heat to 110°C, react for 3h, and finally perform vacuum degassing to obtain amino-modified silicone oil.

[0095] S2. Preparation of fluorine-free polymer processing aid using amino-modified silicone oil

[0096] The mixture obtained by mixing 90 g of polyethylene glycol, 8 g of modified silicone oil, 1.7 g of antioxidant (phosphite), 0.1 g of defoaming agent (tetradecanoic acid), and 0.2 g of dispersant (lauric acid) is the liquid fluorine-free polymer processing aid PPA.

[0097] Embodiment 11

[0098] This embodiment provides a method for preparing a liquid fluorine-free polymer processing aid PPA. Different from Example 9, silicone oil is used in this embodiment to replace modified silicone oil. The raw material formula is: 90g modified polyethylene glycol, 8g silicone oil, 1.7g antioxidant (phosphite), 0.1g defoamer (tetradecanoic acid), 0.2g dispersant (lauric acid). The specific preparation method is:

[0099] S1. Preparation of modified polyethylene glycol

[0100] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0101] S2. Preparation of fluorine-free polymer processing aid using modified polyethylene glycol and amino-modified silicone oil

[0102] The mixture obtained by mixing 90 g of modified polyethylene glycol, 8 g of silicone oil, 1.7 g of antioxidant (phosphite), 0.1 g of defoaming agent (tetradecanoic acid), and 0.2 g of dispersant (lauric acid) is the liquid fluorine-free polymer processing aid PPA.

[0103] Example 12

[0104] This embodiment provides a method for preparing a liquid fluorine-free polymer processing aid PPA. Unlike Example 9, the polyethylene glycol and silicone oil in this embodiment are not modified. The specific preparation method is:

[0105] The mixture obtained by mixing 90 g of polyethylene glycol, 8 g of silicone oil, 1.7 g of antioxidant (phosphite), 0.1 g of defoaming agent (tetradecanoic acid), and 0.2 g of dispersant (lauric acid) is the liquid fluorine-free polymer processing aid PPA.

[0106] Embodiment 13

[0107] This embodiment provides a method for preparing a liquid fluorine-free polymer processing aid PPA. The difference from Example 9 is that the amount of raw materials used in this embodiment is different. The raw material formula is: 10g modified polyethylene glycol, 90g amino-modified silicone oil, 1g antioxidant (phosphite), 0.05g defoamer (tetradecanoic acid), 0.1g dispersant (lauric acid). The specific preparation method is:

[0108] S1. Preparation of modified polyethylene glycol

[0109] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0110] S2. Preparation of amino-modified silicone oil

[0111] Take 300g of dimethylsiloxane as the starting material, add 0.2g of tetramethylammonium hydroxide and 10g of aminosilane coupling agent (γ-aminopropyltriethoxysilane), mix evenly, heat to 60°C and keep warm for 100min, then perform vacuum degassing, then heat to 110°C, react for 3h, and finally perform vacuum degassing to obtain amino-modified silicone oil.

[0112] S3. Preparation of fluorine-free polymer processing aid using modified polyethylene glycol and amino-modified silicone oil

[0113] The mixture obtained by mixing 10 g of modified polyethylene glycol, 90 g of amino-modified silicone oil, 1 g of antioxidant (phosphite), 0.05 g of defoaming agent (tetradecanoic acid), and 0.1 g of dispersant (lauric acid) is the liquid fluorine-free polymer processing aid PPA.

[0114] Embodiment 14

[0115] This embodiment provides a method for preparing a liquid fluorine-free polymer processing aid PPA. The difference from Example 9 is that the amount of raw materials used in this embodiment is different. The raw material formula is: 50g modified polyethylene glycol, 60g amino-modified silicone oil, 3g antioxidant (phosphite), 1g defoamer (tetradecanoic acid), 5g dispersant (lauric acid). The specific preparation method is:

[0116] S1. Preparation of modified polyethylene glycol

[0117] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0118] S2. Preparation of amino-modified silicone oil

[0119] Take 300g of dimethylsiloxane as the starting material, add 0.2g of tetramethylammonium hydroxide and 10g of aminosilane coupling agent (γ-aminopropyltriethoxysilane), mix evenly, heat to 60°C and keep warm for 100min, then perform vacuum degassing, then heat to 110°C, react for 3h, and finally perform vacuum degassing to obtain amino-modified silicone oil.

[0120] S3. Preparation of fluorine-free polymer processing aid using modified polyethylene glycol and amino-modified silicone oil

[0121] The mixture obtained by mixing 50g of modified polyethylene glycol, 60g of amino-modified silicone oil, 3g of antioxidant (phosphite), 1g of defoaming agent (tetradecanoic acid), and 5g of dispersant (lauric acid) is the liquid fluorine-free polymer processing aid PPA.

[0122] Comparative Example 1

[0123] This comparative example provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that in this comparative example, a vinylidene fluoride and hexafluoropropylene copolymer is used to replace modified polyethylene glycol, silicone oil and antioxidant. The raw material formula is: 93.8g of linear low-density polyethylene, 5g of vinylidene fluoride and hexafluoropropylene copolymer, and 1.2g of polyethylene wax. The specific preparation method is:

[0124] 93.8 g of linear low-density polyethylene, 5 g of vinylidene fluoride and hexafluoropropylene copolymer, and 1.2 g of polyethylene wax are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: zone 1 130-140°C, zone 2 140-180°C, zone 3 150-180°C, zone 4 150-180°C, zone 5 160-190°C, zone 6 160-190°C, zone 7 150-180°C, die head temperature 150-180°C, feeding screw speed 400-600rpm, main engine screw speed 180-350rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-containing polymer processing aid PPA.

[0125] Comparative Example 2

[0126] This comparative example provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that this comparative example uses vinylidene fluoride and hexafluoropropylene copolymer to replace silicone oil and antioxidant. The raw material formula is: 93.8g of linear low-density polyethylene, 5g of vinylidene fluoride and hexafluoropropylene copolymer, 1.2g of polyethylene wax, and 0.6g of modified polyethylene glycol. The specific preparation method is:

[0127] S1. Preparation of modified polyethylene glycol

[0128] Polyethylene glycol is placed in a reaction kettle and heated to 100°C for vacuum dehydration until the water content is less than 0.05%. Then the temperature is lowered and the initiator (tert-butyl peroxyvalerate) is added. After stirring evenly, the grafting monomer (ethanol) is gradually added dropwise through a high-level tank. After the reaction, a modified polyethylene glycol containing an ethoxy-OCH2CH3 group is obtained.

[0129] S2. Preparation of fluoropolymer processing aid PPA

[0130] 93.8 g of linear low-density polyethylene, 5 g of vinylidene fluoride and hexafluoropropylene copolymer, 1.2 g of polyethylene wax and 0.6 g of modified polyethylene glycol are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of various zones of the twin-screw extruder are controlled as follows: 130-140° C. for zone one, 140-180° C. for zone two, 150-180° C. for zone three, 150-180° C. for zone four, 160-190° C. for zone five, 160-190° C. for zone six, 150-180° C. for zone seven, the head temperature is 150-180° C., the feed screw speed is 400-600 rpm, the main engine screw speed is 180-350 rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-containing polymer processing aid PPA.

[0131] Comparative Example 3

[0132] This comparative example provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that this comparative example uses vinylidene fluoride and hexafluoropropylene copolymer to replace modified polyethylene glycol and antioxidant. The raw material formula is: 93.8g of linear low-density polyethylene, 5g of vinylidene fluoride and hexafluoropropylene copolymer, 1.2g of polyethylene wax, and 4g of silicone oil. The specific preparation method is:

[0133] 93.8 g of linear low-density polyethylene, 5 g of vinylidene fluoride and hexafluoropropylene copolymer, 1.2 g of polyethylene wax and 4 g of silicone oil are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending, and the temperatures of each zone of the twin-screw extruder are controlled as follows: 130-140° C. for zone one, 140-180° C. for zone two, 150-180° C. for zone three, 150-180° C. for zone four, 160-190° C. for zone five, 160-190° C. for zone six, 150-180° C. for zone seven, the head temperature is 150-180° C., the feeding screw speed is 400-600 rpm, the main engine screw speed is 180-350 rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-containing polymer processing aid PPA.

[0134] Comparative Example 4

[0135] This comparative example provides a method for preparing a solid fluorine-free polymer processing aid. The difference from Example 1 is that this comparative example uses vinylidene fluoride and hexafluoropropylene copolymer to replace modified polyethylene glycol and modified silicone oil. The raw material formula is: 93.8g of linear low-density polyethylene, 5g of vinylidene fluoride and hexafluoropropylene copolymer, 1.2g of polyethylene wax, and 1.2g of antioxidant (phosphite). The specific preparation method is:

[0136] 93.8 g of linear low-density polyethylene, 5 g of vinylidene fluoride and hexafluoropropylene copolymer, 1.2 g of polyethylene wax, and 1.2 g of antioxidant (phosphite) are stirred to obtain a mixture, and then the mixture is put into a twin-screw extruder for melt blending. The temperatures of each zone of the twin-screw extruder are controlled as follows: 130-140° C. for zone one, 140-180° C. for zone two, 150-180° C. for zone three, 150-180° C. for zone four, 160-190° C. for zone five, 160-190° C. for zone six, and 150-180° C. for zone seven, the head temperature is 150-180° C., the feed screw speed is 400-600 rpm, the main engine screw speed is 180-350 rpm, and the melt-plasticized material is cooled and pelletized to obtain a solid fluorine-containing polymer processing aid PPA.

[0137] The performance of the polymer processing aid PPA prepared by the methods of Examples 1 to 14 and Comparative Examples 1 to 4 was tested. The specific testing method was: the prepared polymer processing aid PPA was mixed with polyethylene and then added to a single screw extruder to examine its performance, wherein the added amount of the polymer processing aid PPA was 1% of the total amount of the polymer processing aid PPA and polyethylene.

[0138] During the process of melt extrusion of the material through the single screw extruder, the time to reach stability, torque and torque fluctuation, melt pressure and pressure fluctuation were recorded. The experimental time of each sample exceeded 1 hour so that there was enough time to observe the trend change of the data. The test results are shown in Table 1.

[0139] Table 1

[0140]

[0141]

[0142] It can be seen from the data in the table that the time for the fluorine-free polymer processing aid prepared in the examples of the present application to reach stability is shorter than that of the comparative examples, so that the melt fracture can be eliminated faster during the film blowing process, so that the film bubble is stable and becomes transparent. The torque and torque fluctuation of Examples 1 to 14, as well as the melt pressure and pressure fluctuation are also smaller than those of Comparative Examples 1 to 4, indicating that the samples prepared by the fluorine-free polymer processing aid prepared in the examples of the present application can quickly form a lubricating layer on the die surface, thereby reducing the friction between the plastic melt and the die, and then reducing the die mouth material accumulation. Through the above experiments, it is verified that the fluorine-free polymer processing aid prepared by the method of the present application can effectively eliminate melt fracture and "shark skin" phenomenon, reduce die mouth material accumulation, and improve the uniformity of film thickness. At the same time, the physical and mechanical properties and other optical properties of products such as films have no negative impact, which can improve production efficiency, reduce waste and save energy. Moreover, the polymer processing aid prepared by the method of the present invention does not contain fluorine, which solves the problem that the CF bond existing in the current processing aid is difficult to degrade in the environment and has a long-term impact on human health and the environment.

[0143] Finally, it should be noted that the specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present application is limited by the attached claims rather than the above description, and it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the present application.

Claims

1. A fluorine-free polymer processing aid, characterized in that: The invention comprises the following components: polyethylene glycol or modified polyethylene glycol, silicone oil or modified silicone oil, and an antioxidant; The modification method of the modified polyethylene glycol includes introducing an alkyl group, an alkoxy group, an aromatic ring or an unsaturated functional group into the main chain of the polyethylene glycol by free radical polymerization; The modified silicone oil includes hydroxylated modified silicone oil, amino modified silicone oil or polyether modified silicone oil.

2. A fluorine-free polymer processing aid according to claim 1, characterized in that: When preparing the liquid fluoropolymer-free processing agent, a defoamer and a dispersant are also included.

3. A fluorine-free polymer processing aid according to claim 2, characterized in that: The defoaming agent includes fatty acid, fatty alcohol or fatty acid ester.

4. A fluorine-free polymer processing aid according to claim 2, characterized in that: The dispersant includes fatty acids, fatty amides, ester compounds, low molecular weight wax compounds or metal soap compounds.

5. The fluorine-free polymer processing aid according to claim 1, characterized in that: When preparing the solid fluorine-free polymer processing agent, linear low-density polyethylene and polyethylene wax are also included.

6. A fluorine-free polymer processing aid according to claim 1, characterized in that: The alkyl group includes a methyl group, an ethyl group, a propyl group or an isopropyl group.

7. A fluorine-free polymer processing aid according to claim 1, characterized in that: The alkoxy group includes a methoxy group, an ethoxy group or a propoxy group.

8. The fluorine-free polymer processing aid according to claim 1, characterized in that: The unsaturated functional groups include -CH2CH=CHCH3, -CH2OCH2C=CH2, -(CH2CH3)CH2OCH2C=CH2 or -(CH2CH3)(CH2OCH2C=CH2)2.

9. A method for preparing a fluorine-free polymer processing aid, characterized in that: The following steps are involved: When preparing the liquid fluorine-free polymer processing aid, the raw materials are stirred and mixed to obtain the liquid fluorine-free polymer processing aid; When preparing the solid fluorine-free polymer processing aid, the raw materials are stirred and mixed and then put into a twin-screw extruder for melt blending. The melt-plasticized materials are cooled and pelletized to obtain the solid fluorine-free polymer processing aid.

10. The method for preparing a fluorine-free polymer processing aid according to claim 9, characterized in that: When preparing a solid fluorine-free polymer processing aid, the temperatures of each zone of the twin-screw extruder are controlled as follows: zone 1 130°C-140°C, zone 2 140°C-180°C, zone 3 150°C-180°C, zone 4 150°C-180°C, zone 5 160°C-190°C, zone 6 160°C-190°C, zone 7 150°C-180°C, and the die head temperature is controlled at 150°C-180°C.

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