Anti-aging color master batch for thin film and preparation method of anti-aging color master batch

Abstract

The invention relates to an anti-aging color master batch for a film and a preparation method of the anti-aging color master batch, and belongs to the technical field of polyester color master batches. The color master batch is prepared from the following components: 25 to 32 weight percent of pigment, 0.35 to 0.48 weight percent of modified anti-aging agent, 1.2 to 1.6 weight percent of dispersing agent, 0.1 to 0.12 weight percent of heat stabilizer, 2.8 to 3.6 weight percent of lubricating agent and the balance of PET (Polyethylene Terephthalate) resin, according to the modified anti-aging agent, 3-bromopropanol and tetramethyl piperidylamine are substituted to form an intermediate, then oxalyl chloride monoethyl ester and active alcoholic hydroxyl groups introduced into intermediate molecules are esterified to form a double-chain diester structure, the modified anti-aging agent has high compatibility with a PET matrix and is easy to disperse, the double-chain diester structure containing tertiary amine forms a chelation effect, and the modified anti-aging agent is chelated with a metal-based pigment during blending, so that the anti-aging effect is good. Interface free radicals are efficiently cleared in situ, interface aging is effectively retarded, and a long-acting anti-aging effect is formed.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyester masterbatch, and particularly relates to an anti-aging masterbatch for films and a preparation method thereof. Background Art

[0002] Polyethylene terephthalate (PET) films are widely used in fields such as food packaging, electro-optical films, and outdoor materials due to their excellent mechanical properties, transparency, and chemical resistance. However, PET is prone to photo-oxidative aging and hydrolysis reactions during long-term exposure to ultraviolet light, humid and hot environments, or high-temperature processing, resulting in problems such as deterioration of mechanical properties, yellowing, and interfacial delamination. To improve the anti-aging performance, the prior art mostly uses hindered amine light stabilizers, such as the commonly used light stabilizer 770 and light stabilizer HA-18, which delay photo-degradation by capturing free radicals, but they have the following defects:

[0003] The compatibility of traditional hindered amine light stabilizers with the PET matrix is insufficient, and they are prone to agglomeration during the blending process, resulting in local stress concentration in the film and deterioration of the mechanical properties of the film material; the metal-based inorganic pigments commonly used in masterbatches have poor interfacial binding with PET, there are a large number of defects at the interface, which are prone to cause interfacial oxidation, and rapid aging occurs under a certain aging period, seriously restricting the long-term weather resistance of PET films. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, the purpose of the present invention is to provide an anti-aging masterbatch for films and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] An anti-aging masterbatch for films, the components of which are: 25-32 wt% of pigment, 0.35-0.48 wt% of modified anti-aging agent, 1.2-1.6 wt% of dispersant, 0.1-0.12 wt% of heat stabilizer, and 2.8-3.6 wt% of lubricant, and the balance is PET resin.

[0007] The modified anti-aging agent is prepared by the following method:

[0008] Step A1: Charge and mix tetramethylpiperidineamine, 3-bromopropanol, and dioxane, introduce dry nitrogen for protection, add potassium hydroxide, heat to 85-100 °C, stir and react for 3-4 h, cool and filter to remove potassium hydroxide, and then distill off dioxane under reduced pressure to obtain an intermediate;

[0009] Further, the feeding ratio of tetramethylpiperidinamine, 3-bromopropanol, potassium hydroxide, and dioxane is 0.1 mol: 0.2 mol: 10 - 13 g: 150 - 200 mL. Potassium hydroxide is used as a basic absorbent to promote the substitution of the active amino group of 3-bromopropanol by tetramethylpiperidinamine. The specific reaction route is as follows:

[0010]

[0011] Step A2: Mix the intermediate, triethylamine, and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, control the temperature not higher than 10°C in an ice-water bath, slowly add ethyl oxalyl chloride and stir for 1 - 1.5 h, then raise the temperature to 40 - 50°C and continue stirring and reacting for 2 - 3 h. After the reaction is completed, rotary evaporate to remove tetrahydrofuran to obtain the modified anti-aging agent;

[0012] Further, the feeding ratio of the intermediate, ethyl oxalyl chloride, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 20 - 30 mL: 200 - 280 mL. Triethylamine is used as an acid-binding agent to promote the esterification of the active alcohol hydroxyl group introduced into the intermediate molecule by ethyl oxalyl chloride to form a double-chain double-ester structure. The specific reaction route is as follows:

[0013]

[0014] Further, the dispersant is polyester wax, which has a good lubricating and dispersing effect on inorganic pigments in the PET matrix.

[0015] Further, the heat stabilizer is a phosphite antioxidant, which can effectively prevent the oxidative degradation of the PET matrix during high-temperature processing.

[0016] Further, the lubricant is oleic acid amide, which has a good lubricating effect on the PET matrix and is beneficial to pelletizing.

[0017] A preparation method of an anti-aging masterbatch for films includes the following steps:

[0018] Step S1: Premix the PET resin, pigment, and modified anti-aging agent, and then add the dispersant, heat stabilizer, and lubricant and mix evenly to obtain a compound;

[0019] Step S2: Feed the compound into a twin-screw extruder, plasticize and extrude it, cut it into pellets with water, and dry it to obtain the anti-aging masterbatch.

[0020] Further, during the plasticizing and extrusion process, the temperature settings of the twin-screw extruder are as follows: zone 1: 260 - 270°C, zone 2: 270 - 280°C, zone 3: 280 - 290°C, die head: 285 - 295°C.

[0021] The beneficial effects of the present invention:

[0022] The present invention introduces a modified anti-aging agent into a PET-based masterbatch. The modified anti-aging agent is formed by substituting 3-bromopropanol with tetramethylpiperidineamine to form an intermediate, and then esterifying the active alcohol hydroxyl group introduced into the intermediate molecule with ethyl oxalyl chloride to form a double-chain double-ester structure. Compared with the existing hindered amine antioxidants, the double-chain double-ester structure has excellent compatibility with PET and is easy to disperse during the blending process. Especially in thin film materials, it has little impact on the mechanical properties of the film. The double-chain double-ester structure containing tertiary amine forms a chelating effect, chelates with metal-based pigments during blending, and efficiently scavenges interfacial free radicals in situ, effectively slowing down interfacial aging and forming a long-term anti-aging effect. In addition, due to the chelating complexation, the surface of the metal-based pigments is modified, improving the dispersibility of the pigments and making the dyeing of the masterbatch on the film material more uniform. Detailed implementation mode

[0023] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0024] Example 1, preparation of an anti-aging masterbatch for thin films, specifically as follows:

[0025] (1) Preparation of the modified anti-aging agent

[0026] Step A1: Charge tetramethylpiperidineamine, 3-bromopropanol, and dioxane and mix them. Introduce dry nitrogen for protection, add potassium hydroxide, heat to 85°C, and stir and react for 4 h. Among them, the feeding ratio of tetramethylpiperidineamine, 3-bromopropanol, potassium hydroxide, and dioxane is 0.1 mol: 0.2 mol: 10 g: 150 mL. Cool and filter to remove potassium hydroxide, and then distill off dioxane under reduced pressure to obtain the intermediate.

[0027] Step A2: Charge the intermediate, triethylamine, and anhydrous tetrahydrofuran and mix them. Introduce dry nitrogen for protection, control the temperature not higher than 10°C in an ice-water bath, slowly add ethyl oxalyl chloride and stir for 1.5 h, and then heat to 40°C and continue to stir and react for 3 h. Among them, the feeding ratio of the intermediate, ethyl oxalyl chloride, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 20 mL: 200 mL. After the reaction is completed, rotary evaporate to remove tetrahydrofuran to obtain the modified anti-aging agent.

[0028] (2) Preparation of the masterbatch

[0029] Step S1: Charge materials according to the formulation. The pigment is 25 wt%, and cobalt blue is selected; the modified anti-aging agent is 0.35 wt%, which is self-made in this example; the dispersant is 1.2 wt%, and Licowax OP type polyester wax is selected; the heat stabilizer is 0.12 wt%, and phosphite antioxidant 168 is selected; the lubricant is 2.8 wt%, and oleic acid amide is selected; the balance is PET resin, and the resin raw material of type TRN-8580FC5 is selected. First, add the PET resin, pigment, and modified anti-aging agent to a high-speed mixer for premixing, and then add the dispersant, heat stabilizer, and lubricant and mix them evenly to obtain the compounding material.

[0030] Step S2: Feed the compounding material into a twin-screw extruder. The temperature parameters are set as follows: zone 1 is 260 °C, zone 2 is 270 °C, zone 3 is 280 °C, and the die head is 285 °C. Plasticize and extrude the compounding material, and then pelletize it by water ring cutting and dry it to obtain the aging-resistant masterbatch.

[0031] Example 2. The preparation of the aging-resistant masterbatch for film is as follows:

[0032] (1) Preparation of the modified anti-aging agent

[0033] Step A1: Take tetramethylpiperidineamine, 3-bromopropanol, and dioxane and feed them into a reactor for mixing. Introduce dry nitrogen for protection, add potassium hydroxide, and raise the temperature to 100 °C. Stir and react for 3 h. Among them, the feeding ratio of tetramethylpiperidineamine, 3-bromopropanol, potassium hydroxide, and dioxane is 0.1 mol: 0.2 mol: 13 g: 200 mL. Cool and filter to remove potassium hydroxide, and then distill off dioxane under reduced pressure to obtain the intermediate.

[0034] Step A2: Take the intermediate, triethylamine, and anhydrous tetrahydrofuran and feed them into a reactor for mixing. Introduce dry nitrogen for protection, control the temperature not higher than 10 °C in an ice-water bath, slowly add ethyl oxalyl chloride and stir for 1 h, and then raise the temperature to 50 °C and continue stirring and reacting for 2 h. Among them, the feeding ratio of the intermediate, ethyl oxalyl chloride, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 30 mL: 280 mL. After the reaction is completed, rotary evaporate to remove tetrahydrofuran to obtain the modified anti-aging agent.

[0035] (2) Preparation of the masterbatch

[0036] Step S1: Charge materials according to the formulation. The pigment is 32 wt%, and cobalt blue is selected; the modified anti-aging agent is 0.48 wt%, which is self-made in this example; the dispersant is 1.6 wt%, and Licowax OP type polyester wax is selected; the heat stabilizer is 0.1 wt%, and phosphite antioxidant 168 is selected; the lubricant is 3.6 wt%, and oleic acid amide is selected; the balance is PET resin, and the resin raw material of type TRN-8580FC5 is selected. First, add the PET resin, pigment, and modified anti-aging agent to a high-speed mixer for premixing, and then add the dispersant, heat stabilizer, and lubricant and mix them evenly to obtain the compounding material.

[0037] Step S2: feeding the compound into a twin-screw extruder, setting the temperature parameters to: 270°C for zone 1, 280°C for zone 2, 290°C for zone 3, and 295°C for die head, plasticizing and extruding the compound, pelletizing and drying through a water ring, and obtaining an aging-resistant masterbatch.

[0038] Example 3, preparation of anti-aging masterbatch for film, as follows:

[0039] (1) Preparation of modified antioxidant

[0040] Step A1: Take tetramethylpiperidinamine, 3-bromopropanol and dioxane and mix them, pass dry nitrogen protection, add potassium hydroxide, raise the temperature to 90°C, and stir to react for 3.8 hours, wherein the feed ratio of tetramethylpiperidinamine, 3-bromopropanol, potassium hydroxide and dioxane is 0.1 mol: 0.2 mol: 12 g: 180 mL, cool and filter to remove potassium hydroxide, and then evaporate dioxane under reduced pressure to obtain an intermediate.

[0041] Step A2: Take the intermediate, triethylamine and anhydrous tetrahydrofuran, mix them, pass dry nitrogen for protection, control the temperature in an ice-water bath to be no higher than 10°C, slowly add ethyl oxalyl chloride and stir for 1.2h, then raise the temperature to 45°C and continue stirring to react for 2.6h, wherein the feed ratio of the intermediate, ethyl oxalyl chloride, triethylamine and anhydrous tetrahydrofuran is 0.1mol:0.2mol:25mL:240mL. After the reaction is completed, remove tetrahydrofuran by rotary evaporation to obtain a modified antioxidant.

[0042] (2) Masterbatch preparation

[0043] Step S1: preparing materials according to the components, 30wt% of pigment, cobalt blue is selected; 0.4wt% of modified anti-aging agent is homemade in this embodiment; 1.5wt% of dispersant, Licowax OP type polyester wax is selected; 0.1wt% of heat stabilizer, phosphite antioxidant 168 is selected; 3.2wt% of lubricant, oleic acid amide is selected; the balance is PET resin, TRN-8580FC5 type resin raw material is selected; first add PET resin, pigment and modified anti-aging agent into a high mixer for premixing, then add dispersant, heat stabilizer and lubricant and mix well to obtain a batch.

[0044] Step S2: feeding the compound into a twin-screw extruder, setting the temperature parameters to: 260°C for zone 1, 270°C for zone 2, 280°C for zone 3, and 285°C for die head, plasticizing and extruding the compound, pelletizing and drying through a water ring, and obtaining an aging-resistant masterbatch.

[0045] Example 4, preparation of anti-aging masterbatch for film, as follows:

[0046] (1) Preparation of modified antioxidant

[0047] Step A1: Charge and mix tetramethylpiperidinamine, 3-bromopropanol and dioxane, introduce dry nitrogen for protection, add potassium hydroxide, heat up to 95 °C, and stir for reaction for 3.5 h. Among them, the feeding ratio of tetramethylpiperidinamine, 3-bromopropanol, potassium hydroxide and dioxane is 0.1 mol: 0.2 mol: 12 g: 170 mL. Cool and filter to remove potassium hydroxide, and then distill off dioxane under reduced pressure to obtain an intermediate.

[0048] Step A2: Charge and mix the intermediate, triethylamine and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, control the temperature not higher than 10 °C in an ice-water bath, slowly add ethyl oxalyl chloride and stir for 1.5 h, and then heat up to 405 °C and continue to stir for reaction for 2.2 h. Among them, the feeding ratio of the intermediate, ethyl oxalyl chloride, triethylamine and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 30 mL: 260 mL. After the reaction is completed, distill off tetrahydrofuran by rotary evaporation to obtain a modified anti-aging agent.

[0049] (2) Preparation of masterbatch

[0050] Step S1: Weigh the components as follows: 30 wt% of pigment, cobalt blue is selected; 0.43 wt% of modified anti-aging agent, self-made in this example; 1.4 wt% of dispersant, Licowax OP type polyester wax is selected; 0.11 wt% of heat stabilizer, phosphite antioxidant 168 is selected; 3.2 wt% of lubricant, oleic acid amide is selected; the balance is PET resin, and TRN-8580FC5 type resin raw material is selected. First, add the PET resin, pigment and modified anti-aging agent to a high-speed mixer for premixing, and then add the dispersant, heat stabilizer and lubricant and mix evenly to obtain a compound.

[0051] Step S2: Feed the compound into a twin-screw extruder, and set the temperature parameters as follows: zone 1 at 270 °C, zone 2 at 280 °C, zone 3 at 290 °C, and die head at 295 °C. Plasticize and extrude the compound, cut it into pellets by water ring cutting and dry it to obtain an aging-resistant masterbatch.

[0052] Comparative Example 1: Referring to Example 4, the modified anti-aging agent was replaced with light stabilizer HA-18 in equal amount, and the rest of the implementation process was exactly the same.

[0053] Comparative Example 2: Referring to Example 4, the modified anti-aging agent was replaced with light stabilizer 770 in equal amount, and the rest of the implementation process was exactly the same.

[0054] The masterbatch prepared above was hot-pressed into a sheet specimen, and the aging test was carried out with reference to the standard of GB / T 14522-2008, the test temperature was 55 °C, and the ultraviolet irradiation intensity was 5000 μW / cm 2 , and the color difference ΔE was detected with reference to the standard of ISO 11664-4:2019, as shown in Table 1 specifically:

[0055] Table 1

[0056] ΔE(168h) ΔE(336h) ΔE(504h) ΔE(672h) Example 1 0.16 0.47 0.85 1.36 Example 2 0.11 0.43 0.71 1.02 Example 3 0.15 0.51 0.92 1.21 Example 4 0.13 0.48 0.77 1.10 Comparative Example 1 0.26 0.94 1.73 2.54 Comparative Example 2 0.18 1.05 1.42 1.95

[0057] As can be seen from the test data in Table 1, the color difference change of the masterbatch prepared in the examples during aging is uniform. After 4 weeks of accelerated aging, the color difference is significantly lower than that of the comparative examples, showing a stable long-term anti-aging effect.

[0058] To detect the film-forming performance of the masterbatch, Examples 4, Comparative Example 1, and Comparative Example 2 above were melt-blended and extruded with PET resin at a masterbatch dosage of 10 wt%, and then calendered into films. Tensile tests were carried out with reference to the standard of GB / T 13022-1991, and the maximum color difference ΔEmax was detected at 5 points on the film with reference to ISO 11664-4:2019. The specific results are shown in Table 2:

[0059] Table 2

[0060] Tensile strength / MPa Elongation at break / % ΔEmax Example 4 69.42 112.9 0.073 Comparative Example 1 66.19 107.4 0.105 Comparative Example 2 64.37 102.6 0.147

[0061] As can be seen from the test results in Table 2, when the masterbatch of Example 4 is applied to the film material, it has little influence on the mechanical properties of the film, with an extremely low maximum color difference and more uniform coloring.

[0062] In the description of the specification, the descriptions referring to terms such as "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0063] The above content is only an example and illustration of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the specific embodiments described or use similar methods for substitution, as long as they do not deviate from the invention or exceed the scope defined by the claims of the present invention, they should fall within the protection scope of the present invention.

Claims

1. An anti-aging masterbatch for thin films, characterized in that, The specific components are as follows: 25-32 wt% of pigment, 0.35-0.48 wt% of modified anti-aging agent, 1.2-1.6 wt% of dispersant, 0.1-0.12 wt% of heat stabilizer, and 2.8-3.6 wt% of lubricant, with the balance being PET resin; The modified anti-aging agent is prepared by the following method: Step A1: Charge and mix tetramethylpiperidineamine, 3-bromopropanol, and dioxane, introduce dry nitrogen for protection, add potassium hydroxide, heat to 85-100 °C, stir and react for 3-4 h, cool and filter to remove potassium hydroxide, and then distill off dioxane under reduced pressure to obtain an intermediate; Step A2: Charge and mix the intermediate, triethylamine, and anhydrous tetrahydrofuran, introduce dry nitrogen for protection, control the temperature not higher than 10 °C in an ice-water bath, slowly add ethyl oxalyl chloride and stir for 1-1.5 h, then heat to 40-50 °C and continue to stir and react for 2-3 h. After the reaction, rotary evaporate to remove tetrahydrofuran to obtain the modified anti-aging agent.

2. The anti-aging color masterbatch for thin films according to claim 1, wherein The feeding ratio of tetramethylpiperidineamine, 3-bromopropanol, potassium hydroxide, and dioxane is 0.1 mol: 0.2 mol: 10-13 g: 150-200 mL.

3. The anti-aging color masterbatch for a film according to claim 2, characterized in that, The feeding ratio of the intermediate, ethyl oxalyl chloride, triethylamine, and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 20-30 mL: 200-280 mL.

4. The anti-aging color masterbatch for film according to claim 1, wherein The dispersant is polyester wax.

5. A weather-resistant masterbatch for thin films according to claim 1, characterized in that, The heat stabilizer is phosphite antioxidant.

6. The anti-aging color masterbatch for thin films according to claim 1, wherein The lubricant is oleic acid amide.

7. A preparation method of an anti-aging color masterbatch for a thin film according to any one of claims 1-6, characterized in that, It includes the following steps: Step S1: Premix PET resin, pigment, and modified anti-aging agent, and then add dispersant, heat stabilizer, and lubricant and mix evenly to obtain a compound; Step S2: Feed the compound into a twin-screw extruder, plasticize and extrude, cut into pellets with water, and dry to obtain the anti-aging masterbatch.

8. The preparation method of an anti-aging color masterbatch for a film according to claim 7, characterized in that, During the plasticizing and extruding process, the temperature settings of the twin-screw extruder are as follows: zone 1 is 260-270 °C, zone 2 is 270-280 °C, zone 3 is 280-290 °C, and the die head is 285-295 °C.

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