Frosted master batch for polyester products as well as preparation method and application of frosted master batch

Abstract

The invention discloses a frosted master batch for a polyester product as well as a preparation method and application of the frosted master batch, and belongs to the technical field of high polymer material processing. The frosted master batch is prepared by compounding carrier resin, a light scattering agent, a filling agent and an auxiliary agent according to a specific proportion. During preparation, the frosted master batch with uniform particle size is obtained through the processes of high-speed mixing, melt extrusion, pelletizing and the like; after the frosted master batch is blended with PET slices, a biaxially oriented polyester film can be prepared through a casting-biaxially oriented process or a polyester bottle can be prepared through a two-step bottle blowing process. The polyester product (film / bottle) prepared by the invention is uniform in frosted effect, excellent in comprehensive performance, reasonable in formula, simple in preparation process and low in application cost, and can be widely applied to production of biaxially oriented polyester films and plastic bottle products in the fields of packaging and the like.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials and processing technology, specifically relating to a frosted masterbatch for preparing polyester products with a frosted appearance, and also relating to the preparation method of the frosted masterbatch and its application in the production of biaxially oriented polyester films and polyester bottles. Background Technology

[0002] Polyester materials, with their excellent mechanical properties, chemical resistance, and recyclability, are widely used in food packaging, daily chemical packaging, and electronic packaging. Polyester products with a frosted glass-like appearance are experiencing continued market demand growth due to their advantages such as anti-glare and high-end appearance.

[0003] Currently, the main methods for preparing frosted polyester products include spraying, mold blasting, and masterbatch blending. Spraying requires secondary processing, is complex, costly, and poses environmental pollution issues. Mold blasting requires mold modification, and further modification is needed to restore a smooth finish, resulting in poor flexibility. While masterbatch blending is simple and environmentally friendly, current technologies require a significant amount of fillers such as mica powder to achieve the desired frosted effect, potentially leading to rough surfaces, decreased mechanical properties, and a risk of bottle breakage in blown products. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a frosted masterbatch for polyester products. This frosted masterbatch is suitable for biaxial stretching and blow molding processes. The frosted masterbatch is obtained by co-extrusion granulation of the combined components. Through synergistic effects and ratio optimization of the components, the masterbatch can achieve a soft frosted appearance on the surface of the product after being added to PET in proportion, while maintaining both high light transmittance and moderate haze.

[0005] The second objective of this invention is to provide a method for preparing the above-mentioned abrasive masterbatch for polyester products, which can stably prepare the material.

[0006] The third objective of this invention is to provide the application of the aforementioned frosted masterbatch for polyester products in PET blow molding and PET biaxial stretching molding. By utilizing the blow-blowing / stretching process after heating PET to above its glass transition temperature and below its melting point during the molding process, the micro-phase separation structure of the material is triggered, thereby enabling the product to obtain an ideal frosted optical effect.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a sanding masterbatch for polyester products, comprising the following components in parts by weight: Carrier resin 60-90 parts, light scattering agent 2-8 parts, filler 0-30 parts, additives 1.2-5 parts; The carrier resin is at least one of polyethylene terephthalate-1,4-cyclohexanediethanol ester (PCTG) and polyethylene naphthalate (PEN).

[0008] The principle behind the frosted appearance imparted to PET products by the frosted masterbatch of the present invention is as follows: The selected carrier resin is thermodynamically incompatible with the PET substrate but has good process compatibility. In blow molding or biaxial stretching processes, when the preform undergoes thermal softening and blow-up / stretching, stress-induced phase separation occurs between the amorphous or slowly crystallizing carrier resin and the oriented crystallizing PET, forming a large number of microphase regions. The refractive index difference between these microphase regions and the PET phase regions works together to produce light scattering. Combined with a small amount of light scattering agent in the composition, this gives the product surface a high-quality frosted appearance.

[0009] Preferably, the abrasive masterbatch comprises the following components by weight: 65-90 parts carrier resin, 2-8 parts light scattering agent, 0-30 parts filler, and 1.8-4 parts additives.

[0010] Preferably, the abrasive masterbatch comprises the following components in parts by weight: 70-85 parts carrier resin, 3-6 parts light scattering agent, 5-15 parts filler, and 1.5-4 parts additives.

[0011] Preferably, the carrier resin is polyethylene terephthalate-1,4-cyclohexanediethanol ester (PCTG).

[0012] Preferably, the intrinsic viscosity of the carrier resin is 0.7-0.85 dl / g. This viscosity range ensures that the carrier resin has good processing fluidity and matches the viscosity of PET, which is beneficial for forming uniformly sized microphase regions during phase separation.

[0013] Preferably, the light scattering agent is a mica-based pearlescent pigment with a layered structure.

[0014] More preferably, the mica-based pearlescent pigment has a particle size of less than 40 μm.

[0015] More preferably, the particle size of the mica-based pearlescent pigment is less than 15 μm; more preferably, it is 12-15 μm.

[0016] More preferably, the mica-based pearlescent pigment is mica titanium pearlescent powder coated with titanium dioxide.

[0017] Preferably, the filler is at least one selected from calcium carbonate, talc, barium sulfate, and silica fume.

[0018] More preferably, the filler has a particle size of less than 20 μm.

[0019] More preferably, the filler is at least one of calcium carbonate, talc, barium sulfate, and silica powder that has been surface-treated with a silane coupling agent.

[0020] Preferably, the additives include at least one of dispersants, compatibilizers, antioxidants, and ultraviolet absorbers.

[0021] More preferably, by weight, the additives include 1-5 parts of dispersant, 0-2 parts of compatibilizer, 0.1-0.5 parts of antioxidant and 0.1-0.5 parts of ultraviolet absorber.

[0022] More preferably, the dispersant is at least one selected from ethylene bis-stearamide, pentaerythritol tetrastearate, and stearate.

[0023] More preferably, the compatibilizer is at least one of ethylene-acrylate copolymer, ethylene-vinyl acetate, and copolymer maleic anhydride-grafted polyethylene wax.

[0024] More preferably, the antioxidant is a composite antioxidant system composed of hindered phenolic antioxidants and phosphite antioxidants.

[0025] Most preferably, the antioxidant is a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 2:1.

[0026] More preferably, the ultraviolet absorber is a mixture of UV-531 and UV-9 in a mass ratio of 2:1.

[0027] Secondly, the present invention provides a method for preparing a frosting masterbatch for polyester products, wherein the components of the frosting masterbatch are as described above, and the preparation method includes the following steps: All raw materials were dried at 70±10℃ for 2±0.5h for later use. All raw materials are mixed evenly, melt-extruded, dried, cooled, and pelletized.

[0028] Preferably, the mixing speed is 400-800 r / min and the mixing time is 3-5 min.

[0029] Preferably, the temperature of the melt extrusion is 190-250℃, the main machine speed is controlled at 250-450 rpm, and the screw speed is 300-350 rpm.

[0030] Thirdly, the present invention provides the application of the above-mentioned frosted masterbatch for polyester products in PET blow molding and biaxial stretching molding of cast film.

[0031] Preferably, the amount of the abrasive masterbatch added is 2-4% of the PET mass.

[0032] Preferably, the blow molding process is as follows: the frosted masterbatch and PET chips are dried and mixed, injection molded into a preform, and blow molded to obtain a PET bottle with a frosted appearance.

[0033] More preferably, the drying temperature is 100-130℃, and the material is dried until the residual moisture content is <0.05%; the barrel temperature for injection molding into preforms is 230-280℃ with segmented temperature control, and the injection pressure is 70-120MPa; in the blow molding process, the bottle body is preheated to 90-110℃, the mold temperature is 15-30℃, the pre-blowing pressure is 0.8-1.5MPa for 0.2-0.5s, the main blowing pressure is 3-6MPa for 0.5-1.5s, and the holding pressure is 2-3MPa for 3-8s.

[0034] Preferably, the process of biaxial stretching of the cast film is as follows: the frosted masterbatch and PET chips are dried, mixed, cast or calendered into sheets, and then biaxially stretched to obtain a BOPET film with a frosted appearance.

[0035] More preferably, the drying temperature is 110-130℃, and the material is dried until the residual moisture content is <0.05%; the casting process involves controlling the barrel temperature at 260-270℃, the screw speed at 80-100rpm, and the cooling roller temperature at 15-25℃; the biaxially stretched sheet is preheated to 115-125℃, held for 20-30s, with a stretching ratio of 2-4 and a stretching speed of 140-160mm / s.

[0036] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. Based on the synergistic effect of stress-induced phase separation, light scattering agents, and fillers, the product has a soft and delicate frosted appearance, excellent and uniform effect, and high-grade appearance; 2. The frosted masterbatch has a low addition amount in PET products, resulting in a good frosted appearance; 3. Good applicability: The carrier resin has excellent process compatibility with PET. The frosted masterbatch can be used for both PET blow molding and BOPET biaxial stretching processes, making it highly adaptable. 4. It replaces spraying and mold modification technologies, simplifies production processes, reduces costs, and is easy to promote on a large scale in industrial applications. Attached Figure Description

[0037] Figure 1 From top to bottom, these are bottle pieces cut from polyester bottles prepared according to Comparative Example 1, Example 1, and Example 2.

[0038] Figure 1 The perspective of the three bottle fragments compared to the scenery outside the window is visible under the same lighting conditions. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0040] Unless otherwise specified in the embodiments of this invention, the conditions shall be performed according to conventional conditions or conditions recommended by the manufacturer. All raw materials and reagents used, unless otherwise specified, are commercially available conventional products.

[0041] Examples 1-8 Examples 1-8 provide different formulations of abrasive masterbatch, each of which includes the following components by weight, as shown in Table 1 below.

[0042] Among them, polyethylene terephthalate-1,4-cyclohexanediol ester (PCTG) is Eastman's TX2001; The mica titanium pearl powder is OOK 2111 silver-white pearl powder with a particle size of 800-1000 mesh; Calcium carbonate, talc, barium sulfate, and silica fume are Omyacarb 1T-JI, HS-1000, and Sabari 15B, respectively. The dispersant is ethylene bis-stearamide; The compatibilizer is maleic anhydride-grafted polyethylene wax, with a maleic anhydride grafting rate of 2%. The antioxidant is a compound of antioxidant 1010 and antioxidant 168 in a mass ratio of 2:1. The ultraviolet absorber is a mixture of UV-531 and UV-9 in a mass ratio of 2:1.

[0043] Table 1

[0044] The preparation method of the grinding masterbatch includes the following steps: All raw materials were dried in an 80°C forced-air drying oven for 2 hours and cooled to room temperature for later use. The weighed raw materials were stirred at 400 r / min in a high-speed mixer for 4 minutes to mix evenly. The mixture was then melt-extruded through a twin-screw extruder, cooled, dried, and pelletized to obtain the pellets of this invention. The screw diameter of the co-rotating twin-screw extruder was 30 mm, the length-to-diameter ratio was 48, and the barrel temperature control settings were as follows: Zone 1 190°C, Zone 2 230°C, Zones 3-4 240°C, Zone 5 245°C, the die temperature was 250°C, the main engine speed was controlled at 250 rpm, and the screw speed was 300 rpm.

[0045] Comparative Example 1 This comparative example provides a masterbatch, which differs from Example 1 only in that PET is used as the carrier resin in the masterbatch, while the content of other components and the preparation method are exactly the same as in Example 1, and the PET is YS-Y01.

[0046] Comparative Example 2 This comparative example provides a masterbatch, which differs from Example 2 only in that PET is used as the carrier resin in the masterbatch, while the content of other components and the preparation method are exactly the same as in Example 1, and the PET is YS-Y01.

[0047] Comparative Example 3 This comparative example provides a masterbatch, which differs from Example 1 only in that the light scattering agent is not used in the masterbatch, the carrier resin content is increased to 84 parts, and the content of other components and the preparation method are exactly the same as in Example 1.

[0048] The frosted masterbatch provided in Examples 1-8 and the masterbatch provided in Comparative Examples 1-3 can be blended with PET chips and then used in a two-step blow molding process to produce polyester (PET) bottles. The bottle bodies are then cut into test samples of appropriate size and weight. The abrasive masterbatch accounts for 2% of the mass of PET, and the PET is YS-Y01.

[0049] The blow molding process is a two-step method, specifically including: a) Drying and mixing: using a dehumidifying dryer, drying temperature 100℃, drying time 2 hours, ensuring that the residual moisture content of the material is <0.05%; b) Injection molding of preform: segmented temperature control of the barrel at 260℃, injection pressure 100MPa, holding pressure 60MPa, cooling for 20s, mold temperature 25℃; c) Preform blow molding: preheating of the bottle body to 95℃, mold temperature 25℃, pre-blowing 0.9MPa / 0.3s, main blow 5.0MPa / 1.0s, holding pressure 2.0MPa / 5s.

[0050] Comparative Example 4 This comparative example provides an application method in which the abrasive masterbatch provided in Example 1 is blended with PCTG (Eastman's TX2001), and then PCTG bottles are prepared by a two-step blow molding process. The prepared bottle body is cut into test samples of appropriate size and weight.

[0051] The blow molding process is a two-step method, specifically including: a) Drying and mixing: using a dehumidifying dryer, drying temperature 65℃, drying time 4 hours, ensuring that the residual moisture content of the material is <0.05%; b) Injection molding of preform: segmented temperature control of the barrel at 200℃, injection pressure 80MPa, holding pressure 40MPa, cooling for 15s, mold temperature 15℃; c) Preform blow molding: preheating of the bottle body to 110℃, mold temperature 20℃, pre-blowing 0.8MPa / 0.2s, main blow 3.0MPa / 0.5s, holding pressure 2.0MPa / 3s.

[0052] The following are application examples of the above embodiments and comparative examples, including transmittance and haze tests: The test results are shown in Table 2. Table 2

[0053] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A matte masterbatch for polyester articles, characterized in that, The components include the following components by weight fraction: The carrier resin 60-90 parts, light scattering agent 2-8 parts, filler 0-30 parts, auxiliary agent 1.2-5 parts; The carrier resin is at least one of polyethylene terephthalate-1, 4-cyclohexane dimethyl ester and polyethylene naphthalate.

2. The abrasive master granules according to claim 1, characterized in that, The components include the following components by weight fraction: carrier resin 65-90 parts, light scattering agent 2-8 parts, filler 0-30 parts, auxiliary agent 1.8-4 parts; Or, the components include the following components by weight fraction: carrier resin 70-85 parts, light scattering agent 3-6 parts, filler 5-15 parts, auxiliary agent 1.5-4 parts.

3. The abrasive master granules according to claim 1, characterized in that, The intrinsic viscosity of the carrier resin is 0.7-0.85 dl / g; And / or, the carrier resin is polyethylene terephthalate-1, 4-cyclohexane dimethyl ester.

4. The abrasive master granules according to claim 1, characterized in that, The light scattering agent is a mica-based pearl pigment with a lamellar structure; more preferably, it is a titanium dioxide coated mica titanium pearl powder; And / or, the particle size of the light scattering agent is less than 40 μm, more preferably less than 15 μm.

5. The abrasive master granules according to claim 1, wherein The filler is at least one of calcium carbonate, talc, barium sulfate and silicon powder; more preferably, it is at least one of silane coupling agent surface treated calcium carbonate, silane coupling agent surface treated talc, silane coupling agent surface treated barium sulfate and silane coupling agent surface treated silicon powder; And / or, the particle size of the filler is less than 20 μm.

6. The abrasive master granules according to claim 1, wherein The auxiliary agent includes at least one of dispersant, compatibilizer, antioxidant and ultraviolet absorber; more preferably, by weight fraction, the auxiliary agent includes 1-5 parts of dispersant, 0-2 parts of compatibilizer, 0.1-0.5 parts of antioxidant and 0.1-0.5 parts of ultraviolet absorber.

7. The abrasive master granules according to claim 1, wherein The dispersant is at least one of ethylene bis-stearamide, pentaerythritol tetra-stearate and stearate; And / or, the compatibilizer is at least one of ethylene-acrylate copolymer, ethylene-vinyl acetate and polyethylene wax grafted with maleic anhydride copolymer; And / or, the antioxidant is a composite antioxidant system composed of hindered phenolic antioxidant and phosphite antioxidant; more preferably, it is a composite of antioxidant 1010 and antioxidant 168 in a mass ratio of 2:1; And / or, the ultraviolet absorber is a composite of UV-531 and UV-9 in a mass ratio of 2:

1.

8. Process for the preparation of the matte masterbatch for polyester articles according to any one of claims 1 to 7, characterized in that, The steps include: After drying the raw materials, mix them evenly, melt extrude, dry, cool, and granulate to form.

9. The application of the matte masterbatch for polyester products in PET bottle blowing molding and biaxial stretching of cast film according to any one of claims 1-7.

10. Use according to claim 9, characterized in that, The addition amount of the matte masterbatch is 2-4% of the mass of PET; And / or, the bottle blowing molding process is: the matte masterbatch and PET chips are dried and mixed, injection molded into bottle embryos, and blown to obtain PET bottles with a matte appearance; And / or, the biaxial stretching of cast film process is: the matte masterbatch and PET chips are dried and mixed, cast or calendered into sheets, and then biaxially stretched to obtain BOPET film with a matte appearance; The heating temperature of the bottle blowing forming process and the cast film biaxial stretching forming process are both higher than the glass transition temperature of PET and lower than the melting point of PET.

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