Polyester transparent injection molding demolding master batch and preparation method and application thereof

Abstract

The application relates to the technical field of injection molding demolding master batches, in particular to a polyester transparent injection molding demolding master batch and a preparation method and application thereof. According to mass proportions, 85% to 97% of a carrier and 3% to 15% of a lubricant are included; the lubricant includes zinc bungarotoxin, zinc cinnamate and octadecyl octadecanoate with a mass ratio of (2 to 6):(2 to 6):(1 to 4). The lubricant with the specific component ratio improves the fluidity and demolding property of the polyester product and reduces the haze.

Description

Technical Field

[0001] This invention relates to the field of injection molding release masterbatch technology, and more specifically, to a polyester transparent injection molding release masterbatch, its preparation method, and its application. Background Technology

[0002] Polyethylene terephthalate (PET) and polyethylene terephthalate-1,4-cyclohexanedimethyl terephthalate (PETG) are important polyester materials, widely used in cosmetic bottles, beverage bottles, and plastic vacuum blood collection tubes due to their advantages such as high transparency, high strength, and lightweight. When injection molding small, thin-walled products with a high flow-to-length ratio, polyester materials are required to have good flow properties, easy demolding, good appearance quality, and dimensional stability. However, ordinary polyester chips are difficult to meet these ideal processing requirements.

[0003] Currently, the main method to improve fluidity and achieve easy demolding is to add stearates, lignite acid, polyethylene glycol, polyester polyols, silicone resins, and polyethylene waxes to the polyester carrier. However, these lubricants have problems such as small molecular weight, unstable properties, poor high temperature resistance, and easy to increase the haze of polyester materials. Moreover, the raw material ratio is complicated, the production process is cumbersome, and the operation procedures are complicated.

[0004] Therefore, traditional techniques need to be improved. Summary of the Invention

[0005] In view of this, the present invention aims to at least partially solve one of the technical problems in the above-mentioned related technologies. To this end, the present invention provides a transparent polyester injection molding release masterbatch, its preparation method and application, which improves the flowability and release properties of polyester products and reduces haze by using a lubricant with a specific composition ratio.

[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0007] In a first aspect, the present invention provides a transparent polyester injection molding release masterbatch, comprising, by mass percentage: 85% to 97% carrier and 3% to 15% lubricant;

[0008] The lubricant comprises zinc crotonate, zinc cinnamate, and stearyl octadecyl ester in a mass ratio of (2~6):(2~6):(1~4).

[0009] Compared with existing technologies, this claim constructs a synergistic lubrication system of metal salts and fatty acid esters by specifying a precise ratio of (2~6):(2~6):(1~4), solving the core problem of existing single mixed lubricants that are difficult to balance in terms of "flowability, mold release properties, and transparency". Specifically, the unsaturated double bonds of zinc crotonate can disrupt the regularity of the PET / PETG molecular chain, reducing melt viscosity; the aromatic ring structure of zinc cinnamate can enhance the lubrication and isolation effect with the mold surface; and the long-chain alkyl group of octadecyl stearate can further reduce the coefficient of friction. The synergistic effect of these three components increases the melt index of the polyester material and reduces the mold release force. Furthermore, the molecular structures of the three lubricants in this invention have better compatibility with the polyester carrier, and the optimized ratio allows for uniform dispersion in the carrier, greatly improving the transparency of the product.

[0010] Furthermore, the carrier is PETG.

[0011] Furthermore, the viscosity of the PETG is 0.6 dL / g to 0.85 dL / g.

[0012] Furthermore, it also includes a transparent compatibility accelerator; the mass percentages of each component are: 85%~96% carrier, 3%~14% lubricant and 0.1%~1% transparent compatibility accelerator.

[0013] Compared with existing technologies, this invention introduces a transparent compatibility promoter, which further solves the interfacial tension problem between the lubricant and the carrier, achieving simultaneous improvement in "dispersion uniformity, transparency, and storage stability". The transparent compatibility promoter can act as a "bridge", forming hydrogen bonds with the ester bonds of PET / PETG on one end and being compatible with the hydrophobic groups of the lubricant on the other end, thereby reducing the particle size of the lubricant dispersion and further improving the transparency of the product.

[0014] Furthermore, the transparency compatibility promoter includes polyethylene glycol monomethyl ether methacrylate (PEGMA).

[0015] Secondly, the present invention provides a method for preparing a transparent polyester injection molding masterbatch, which is applied to the aforementioned transparent polyester injection molding masterbatch, comprising the following processes:

[0016] Weigh each component according to the specified ratio of the polyester transparent injection molding masterbatch;

[0017] After vacuum drying of the carrier, the lubricant is added, and the mixture is granulated to obtain the target polyester transparent injection molding masterbatch.

[0018] Compared with existing technologies, the above preparation method is simple and controllable, solving the problems of cumbersome production process and complicated operation in existing technologies, while ensuring the uniformity and performance stability of the masterbatch.

[0019] Furthermore, after adding the lubricant and before granulation, the transparent compatibility promoter is also added.

[0020] Compared with existing technologies, this invention adds a transparent compatibility accelerator before granulation, which allows the accelerator to fully contact the carrier and lubricant during the melt blending stage, forming a uniform mixture system. This avoids problems such as excessively high local concentrations or uneven dispersion caused by subsequent additions.

[0021] Furthermore, the vacuum drying is carried out at -0.08~-0.10MPa and 70℃~80℃ for 3h~6h.

[0022] Compared with existing technologies, vacuum drying using the above-mentioned conditions avoids the problems of insufficient or excessive drying, ensuring the drying quality of the carrier and the performance stability of the masterbatch.

[0023] Furthermore, during the granulation process, the screw temperatures for each section are set as follows: T1 is 160℃~185℃, T2 is 190℃~210℃, and T3-T14 is 215℃~230℃; the screw load is 20kg / h~40kg / h, and the screw speed is 200rpm~500rpm.

[0024] Compared with existing technologies, the gradient temperature control of T1 (160℃~185℃), T2 (190℃~210℃), and T3-T14 (215℃~230℃), combined with the screw load of 20kg / h~40kg / h and the speed of 200rpm~500rpm, can fully melt and mix the carrier, lubricant, and compatibility promoter, avoiding local overheating or uneven mixing.

[0025] Thirdly, the present invention provides the application of the aforementioned transparent polyester injection molding release masterbatch in the preparation of polyester products.

[0026] In summary, the technical effects achieved by this invention are as follows:

[0027] Synergistic optimization of lubrication and flow properties: Compared with the single / simple mixed lubricants in the prior art, the present invention achieves simultaneous improvement of flowability and demolding performance through a composite lubricant system of "zinc crotonate + zinc cinnamate + octadecyl alcohol ester" with a specific ratio. The melt index is greatly improved and demolding is easier, which is fully adapted to the injection molding requirements of thin-walled products with a large flow length ratio. It solves the pain point of the prior art that it is difficult to balance flowability and demolding performance.

[0028] Significantly improved transparency: The composite lubricant has excellent compatibility with PET / PETG carriers, and with the use of a transparency compatibility promoter, the haze of the product is significantly reduced, breaking through the industry bottleneck of the contradiction between lubrication and demolding and transparency, and meeting the requirements of optical-grade applications.

[0029] Outstanding high temperature resistance and stability: The thermal decomposition temperature of each component in the composite lubricant is ≥280℃. With precise preparation process, there is no decomposition during extrusion and injection molding at 200~250℃. The product still has no reduction in demolding performance after 1000 high temperature sterilization cycles. The masterbatch does not separate after 6 months of storage at room temperature.

[0030] Strong carrier adaptability and versatility: The use of PET and PETG composite carrier takes into account the high strength of PET and the excellent processing fluidity of PETG, and can be flexibly adapted to different scenarios such as cosmetic bottles and vacuum blood collection tubes.

[0031] The preparation process is simple and environmentally friendly: the preparation process does not require complicated pretreatment steps. Through precise vacuum drying (-0.08~-0.10MPa, 70℃~80℃, 3h~6h) and segmented temperature control granulation parameters, the bubble defect rate of the product is significantly reduced. The components do not contain organic solvents, and there is no wastewater or waste gas emission during the production process, which meets the environmental compliance requirements for medical and food contact materials. Detailed Implementation

[0032] The present application will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present application.

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges or individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] Unless otherwise specified, the term "comprising" as used in this invention can be either open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0035] Unless otherwise specified, all technical features and optional technical features of this invention can be combined to form new technical solutions.

[0036] Unless otherwise specified, all steps of the present invention may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0037] Example 1

[0038] This embodiment provides a transparent polyester injection molding release masterbatch, which, by mass percentage, comprises: 85% carrier and 15% lubricant; the lubricant comprises zinc crotonate, zinc cinnamate, and octadecyl stearate in a mass ratio of 2:2:1; the carrier is PETG; the viscosity of PETG is 0.85 dL / g.

[0039] The preparation process of the above injection molding release masterbatch is as follows:

[0040] Weigh each component according to the above-mentioned proportions of the polyester transparent injection molding masterbatch;

[0041] PETG was dried at -0.08 MPa and 70℃ for 3 hours, then placed in a Nanjing Keerke KTE-36 co-rotating twin-screw extruder for compounding. Zinc crotonate, zinc cinnamate, and stearyl octadecyl ester were added. The screw temperatures for each section were set as follows: T1 160℃, T2 190℃, and T3-T14 215℃. The screw load was 20 kg / h, and the screw speed was 200 rpm. The product was extruded into strips through a 4-hole die, cooled in a water bath, and then granulated by a pelletizer to finally obtain polyester masterbatch chips.

[0042] Example 2

[0043] This embodiment provides a transparent polyester injection molding release masterbatch, which, by mass percentage, comprises: 97% carrier and 3% lubricant; the lubricant includes zinc crotonate, zinc cinnamate, and octadecyl stearate in a mass ratio of 6:6:4; the carrier is PETG; the viscosity of PETG is 0.6 dL / g.

[0044] The preparation process of the above injection molding release masterbatch is as follows:

[0045] Weigh each component according to the above-mentioned proportions of the polyester transparent injection molding masterbatch;

[0046] PETG was dried at -0.10 MPa and 80℃ for 6 hours, and then placed in a Nanjing Keerke KTE-36 co-rotating twin-screw extruder for compounding. Zinc crotonate, zinc cinnamate, and stearyl octadecyl ester were added. The screw temperatures for each section were set as follows: T1 185℃, T2 210℃, and T3-T14 230℃. The screw load was 40 kg / h, the screw speed was 500 rpm, and the product was extruded into strips through a 4-hole die. After cooling in a water bath, the strips were granulated by a pelletizer to finally obtain polyester masterbatch chips.

[0047] Example 3

[0048] This embodiment provides a transparent polyester injection molding release masterbatch, which, by mass percentage, comprises: 92% carrier and 8% lubricant; the lubricant comprises zinc crotonate, zinc cinnamate, and octadecyl stearate in a mass ratio of 3:4:3; the carrier is PETG; the viscosity of PETG is 0.75 dL / g.

[0049] The preparation process of the above injection molding release masterbatch is as follows:

[0050] Weigh each component according to the above-mentioned proportions of the polyester transparent injection molding masterbatch;

[0051] PETG was dried at -0.09 MPa and 75℃ for 4 hours, then placed in a Nanjing Keerke KTE-36 co-rotating twin-screw extruder for compounding. Zinc crotonate, zinc cinnamate, and stearyl octadecyl ester were added. The screw temperatures for each section were set as follows: T1 180℃, T2 200℃, and T3-T14 220℃. The screw load was 25 kg / h, and the screw speed was 300 rpm. The product was extruded into strips through a 4-hole die, cooled in a water bath, and then granulated by a pelletizer to finally obtain polyester masterbatch chips.

[0052] Example 4

[0053] This embodiment provides a transparent polyester injection molding release masterbatch, which, by weight percentage, comprises: 85% carrier, 14% lubricant, and 1% transparent compatibility accelerator; the lubricant includes zinc crotonate, zinc cinnamate, and octadecyl stearate in a weight ratio of 4:3:3; the carrier is PETG; the viscosity of PETG is 0.72 dL / g; and the transparent compatibility accelerator includes polyethylene glycol monomethyl ether methacrylate (PEGMA).

[0054] The preparation process of the above injection molding release masterbatch is as follows:

[0055] Weigh each component according to the above-mentioned proportions of the polyester transparent injection molding masterbatch;

[0056] PETG was dried at -0.0 MPa and 70℃ for 3 hours, then placed in a Nanjing Keerke KTE-36 co-rotating twin-screw extruder for compounding. Zinc crotonate, zinc cinnamate, octadecyl ester, and polyethylene glycol monomethyl ether methacrylate (PEGMA) were added. The screw temperatures for each section were set as follows: T1 160℃, T2 190℃, and T3-T14 215℃. The screw load was 20 kg / h, and the screw speed was 200 rpm. The product was extruded into strips through a 4-hole die, cooled in a water bath, and then granulated by a pelletizer to finally obtain polyester masterbatch chips.

[0057] Example 5

[0058] This embodiment provides a transparent polyester injection molding release masterbatch, which, by mass percentage, comprises: 96% carrier, 3.99% lubricant, and 0.01% transparent compatibility accelerator; the lubricant comprises zinc crotonate, zinc cinnamate, and octadecyl stearate in a mass ratio of (2~6):(2~6):(1~4); the carrier is PETG; the viscosity of PETG is 0.6 dL / g; and the transparent compatibility accelerator comprises polyethylene glycol monomethyl ether methacrylate (PEGMA).

[0059] The preparation process of the above injection molding release masterbatch is as follows:

[0060] Weigh each component according to the above-mentioned proportions of the polyester transparent injection molding masterbatch;

[0061] PETG was dried at -0.10 MPa and 80℃ for 6 hours, and then placed in a Nanjing Keerke KTE-36 co-rotating twin-screw extruder. Zinc crotonate, zinc cinnamate, stearyl octadecyl ester, and polyethylene glycol monomethyl ether methacrylate (PEGMA) were added. The screw temperatures for each section were set as follows: T1 185℃, T2 210℃, and T3-T14 230℃. The screw load was 40 kg / h, and the screw speed was 500 rpm. The product was extruded into strips through a 4-hole die, cooled in a water bath, and then granulated by a pelletizer to finally obtain polyester masterbatch chips.

[0062] Example 6

[0063] This embodiment provides a transparent polyester injection molding release masterbatch, which, by weight percentage, comprises: 90% carrier, 9.5% lubricant, and 0.5% transparent compatibility accelerator; the lubricant includes zinc crotonate, zinc cinnamate, and octadecyl stearate in a weight ratio of 4:5:3; the carrier is PETG; the viscosity of PETG is 0.80 dL / g; and the transparent compatibility accelerator includes polyethylene glycol monomethyl ether methacrylate (PEGMA).

[0064] The preparation process of the above injection molding release masterbatch is as follows:

[0065] Weigh each component according to the above-mentioned proportions of the polyester transparent injection molding masterbatch;

[0066] PETG was dried at -0.09 MPa and 75℃ for 4 hours, then placed in a Nanjing Keerke KTE-36 co-rotating twin-screw extruder for compounding. Zinc crotonate, zinc cinnamate, stearyl octadecyl ester, and polyethylene glycol monomethyl ether methacrylate (PEGMA) were added. The screw temperatures for each section were set as follows: T1 180℃, T2 200℃, and T3-T14 220℃. The screw load was 25 kg / h, and the screw speed was 300 rpm. The product was extruded into strips through a 4-hole die, cooled in a water bath, and then granulated by a pelletizer to finally obtain polyester masterbatch chips.

[0067] Comparative Example 1

[0068] In Comparative Example 1, the difference from Example 6 is that zinc cinnamate was replaced with an equal amount of zinc crotonate, while the other components and preparation methods remained unchanged.

[0069] Comparative Example 2

[0070] In Comparative Example 2, the difference from Example 6 is that zinc cinnamate is replaced with an equal amount of zinc crotonate, while the other components and preparation methods remain unchanged.

[0071] Comparative Example 3

[0072] In Comparative Example 3, the difference from Example 6 is that an equal amount of zinc cinnamate was used to replace octadecyl cinnamate, while the other components and preparation methods remained unchanged.

[0073] Comparative Example 4

[0074] In Comparative Example 4, the difference from Example 6 is that an equal amount of octadecyl ester of stearate was used to replace zinc cinnamate, while the other components and preparation methods remained unchanged.

[0075] Comparative Example 5

[0076] In Comparative Example 5, the difference from Example 6 is that an equal amount of octadecyl ester was used to replace zinc crotonate, while the other components and preparation methods remained unchanged.

[0077] Comparative Example 6

[0078] In Comparative Example 6, the difference from Example 6 is that zinc stearate is replaced with an equal amount of zinc cinnamate, while the other components and preparation methods remain unchanged.

[0079] The masterbatches of Examples 1 to 6 and Comparative Examples 1 to 6 were added to the polyester base material at an addition ratio of 5% wt to obtain the final polyester product. The haze and melt index of each group of polyester products were measured, as shown in Table 1 below.

[0080] Table 1

[0081]

[0082] The results above show that the polyester base materials prepared from the masterbatches of Examples 1-6 of this invention have lower haze values, higher transparency, better flowability, and smoother demolding. In contrast, the masterbatches of Comparative Examples 1-6 have higher haze values ​​and poorer flowability. This indicates that zinc crotonate, zinc cinnamate, and octadecyl stearate work synergistically and are indispensable. Only when all three are used together as lubricants can the melt index of the polyester material be increased, the demolding force be reduced, and the transparency of the product be greatly improved.

[0083] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0084] The basic principles of the present invention have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in the present invention are merely examples and not limitations, and should not be considered as essential features of each embodiment of the present invention. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the present invention to the necessity of employing the aforementioned specific details.

[0085] In the foregoing description of this specification, references to terms such as "one embodiment," "another embodiment," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples, without contradiction. Additionally, it should be noted that in this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A transparent polyester injection molding release masterbatch, characterized in that, Based on mass percentage, it includes: 85%~97% carrier and 3%~15% lubricant; The lubricant comprises zinc crotonate, zinc cinnamate, and stearyl octadecyl ester in a mass ratio of (2~6):(2~6):(1~4); The carrier is PETG.

2. The polyester transparent injection molding release masterbatch according to claim 1, characterized in that, The viscosity of the PETG is 0.6 dL / g to 0.85 dL / g.

3. The polyester transparent injection molding release masterbatch according to claim 1, characterized in that, It also includes a transparent compatibility accelerator; in the polyester transparent injection molding release masterbatch, the mass percentage of each component is: 85%~96% carrier, 3%~14% lubricant and 0.1%~1% transparent compatibility accelerator; the lubricant includes zinc crotonate, zinc cinnamate and octadecyl stearate in a mass ratio of (2~6):(2~6):(1~4); the carrier is PETG.

4. The polyester transparent injection molding release masterbatch according to claim 3, characterized in that, The transparent compatibility promoter includes polyethylene glycol monomethyl ether methacrylate (PEGMA).

5. A method for preparing a transparent polyester injection molding masterbatch, applied to the transparent polyester injection molding masterbatch according to any one of claims 1 to 4, characterized in that, The process includes the following: Weigh each component according to the proportion of the polyester transparent injection molding masterbatch according to any one of claims 1 to 4; After vacuum drying of the carrier, the lubricant is added, and the mixture is granulated to obtain the target polyester transparent injection molding masterbatch.

6. The method for preparing a transparent polyester injection molding release masterbatch according to claim 5, characterized in that, After adding the lubricant, the transparent compatibility promoter is also added before granulation.

7. A method for preparing a transparent polyester injection molding release masterbatch according to any one of claims 5 to 6, characterized in that, The vacuum drying is carried out at -0.08 to -0.10 MPa and 70 to 80°C for 3 to 6 hours.

8. A method for preparing a transparent polyester injection molding release masterbatch according to any one of claims 5 to 6, characterized in that, During the granulation process, the screw temperatures for each section are set as follows: T1 is 160℃~185℃, T2 is 190℃~210℃, and T3-T14 is 215℃~230℃; the screw load is 20kg / h~40kg / h, and the screw speed is 200rpm~500rpm.

9. The use of the polyester transparent injection molding release masterbatch according to any one of claims 1 to 4 in the preparation of polyester products.

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