High-weather-resistance low-gloss rigid polyvinyl chloride film, and preparation method and application thereof

Abstract

This invention relates to the field of polymer materials technology, and discloses a high weather-resistant, low-gloss rigid polyvinyl chloride film, its preparation method, and its application. The film comprises, by weight, 100 parts of polyvinyl chloride resin, 10 parts of matte polyvinyl chloride resin, 1-2.5 parts of stabilizer, 1-5 parts of processing aid, 5-10 parts of polymer modifier, 0.2-1 part of internal lubricant, 0.2-0.7 parts of external lubricant, 0.2-0.7 parts of antioxidant, 0.8-3 parts of UV absorber A, 0.8-3 parts of UV absorber B, and 0.4-1.2 parts of UV absorber C. This invention is completely free of plasticizers and complies with RoHS, REACH and other environmental standards. Three UV absorbers synergistically cover the entire 250-405nm UV spectrum, significantly improving weather resistance. Utilizing planetary screw extrusion, two-roll open milling, and five-roll calendering processes, the film, after 300 hours of UV aging, exhibits a color difference value ΔE ≤ 0.15 and an outdoor service life of 15-20 years. This invention solves the problems of easy plasticizer migration and insufficient weather resistance in traditional low-gloss PVC films, making it suitable for home decoration materials or packaging materials.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high weather-resistant, low-gloss rigid polyvinyl chloride film, its preparation method, and its applications, particularly suitable for outdoor home decoration and packaging materials. Background Technology

[0002] Low-gloss polyvinyl chloride (PVC) film is widely used in decoration and packaging due to its attractive appearance and low processing cost. However, traditional PVC film has two major drawbacks that limit its application in high-end and outdoor scenarios:

[0003] 1. Poor environmental performance: To improve processing fluidity, traditional formulations require the addition of 15-40 parts of phthalate plasticizers (such as DEHP and DINP). These plasticizers are prone to migration and precipitation (migration rate >3% after accelerated aging, GB / T 21928-2008), which not only leads to film hardening and embrittlement but may also contaminate food or skin through contact, making it difficult to meet EU REACH Annex XVII (limit <0.1%) and RoHS (heavy metals Pb / Cd / Cr) requirements. 6+ Environmental standards such as <100ppm.

[0004] 2. Insufficient weather resistance: In outdoor applications, ultraviolet radiation in the 250–405 nm wavelength band is the main cause of PVC film aging—UV radiation breaks the C-Cl bonds in the PVC molecular chain, leading to degradation and yellowing (color difference ΔE ≥ 0.5, GB / T 250-2008), tensile strength reduction > 30% (GB / T 1040.3-2006), and an outdoor service life of only 3–5 years. Existing improvement solutions (such as patent CN101914252B) disclose plasticizer-free rigid PVC composites, but do not involve UV protection design; some solutions (such as CN118994727A) only add a single UV absorber, which can only cover the 280–350 nm wavelength band, leaving gaps in protection for the 250–280 nm (UVC) and 350–405 nm (UVA) wavelength bands.

[0005] Therefore, we propose a high weather-resistant, low-gloss rigid polyvinyl chloride film, its preparation method, and its application. Summary of the Invention

[0006] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a high weather-resistant, low-gloss rigid polyvinyl chloride film, its preparation method, and its application, thereby overcoming the technical defects of traditional plasticized PVC films, such as poor weather resistance, easy aging, and the presence of environmentally harmful substances.

[0007] This invention provides a high weather-resistant, low-gloss rigid polyvinyl chloride film, comprising the following components by weight:

[0008] 100 parts of polyvinyl chloride resin;

[0009] 10 parts of matte polyvinyl chloride resin;

[0010] Stabilizer 1-2.5 parts;

[0011] Processing aids: 1-5 parts;

[0012] 5-10 parts of polymer modifier;

[0013] Internal lubricant 0.2 to 1 part;

[0014] External lubricant: 0.2–0.7 parts;

[0015] Antioxidant 0.2–0.7 parts;

[0016] Ultraviolet absorber A: 0.8–3 parts;

[0017] Ultraviolet absorber B: 0.8–3 parts;

[0018] Ultraviolet absorber C: 0.4–1.2 parts;

[0019] in:

[0020] (a) None of the raw material components contain plasticizers;

[0021] (b) The raw material components contain 10 or more parts of matte polyvinyl chloride resin, which is a low-gloss film;

[0022] (c) The ultraviolet absorbers A, B, and C respectively cover the ultraviolet bands of 250–350 nm, 280–385 nm, and 390–405 nm.

[0023] (d) The ultraviolet absorber A is a phenol triazine compound, the ultraviolet absorber B is a benzotriazole phenol compound, and the ultraviolet absorber C is a hydroxyphenyl triazine compound.

[0024] Specifically, the polyvinyl chloride resin is selected from at least one of SG-7 and SG-5; the stabilizer is an organotin stabilizer or a calcium-zinc composite stabilizer.

[0025] Specifically, the processing aid is selected from acrylic resin or methacrylic acid processing aid; the antioxidant is selected from powdered phosphite or liquid phenyl phosphite.

[0026] Specifically, the polymer modifier is at least one of ACR, ABS, or MBS; the internal lubricant is butyl stearate or polyol complex ester; and the external lubricant is selected from calcium stearate, zinc stearate, oxidized polyethylene wax, or lignite ester wax.

[0027] Specifically, the mass ratio of ultraviolet absorber A, ultraviolet absorber B, and ultraviolet absorber C is 5:5:2.

[0028] This invention discloses a method for preparing a high-weather-resistant, low-gloss rigid polyvinyl chloride film, comprising the following steps:

[0029] Step 1: Weigh each ingredient according to the above proportions;

[0030] Step 2: Add the raw materials to a hot mixer and mix at 80-120°C for 6-10 minutes until homogeneous;

[0031] Step 3: The mixture is pre-plasticized and extruded using a planetary screw extruder at 160–185℃, wherein the shear rate of the planetary screw extruder is 200–405 s. -1 ;

[0032] Step 4: The extruded material is further plasticized in a two-roll mill at 140-170℃, with a roll speed ratio of 1.2:1.

[0033] Step 5: The plasticized material is calendered in a five-roll calender at 190-220℃, where the linear speed of the five-roll calender is 10-30 m / min;

[0034] Step 6: After stretching, cooling and shaping, trimming and winding, a film with a thickness of 0.1 to 0.15 mm is obtained.

[0035] The preparation method is further specified. In step 3, the temperature gradient of the planetary screw extruder is: 160-170°C in barrel zone 1, 170-180°C in barrel zone 2, and 180-185°C in the center screw. This gradient can avoid material coking or insufficient pre-plasticization.

[0036] In a further specific preparation method, the temperature distribution of the five-roll calender in step 5 is as follows: first roll 190-200℃, second roll 200-210℃, third roll 210-215℃, fourth roll 215-220℃, and fifth roll 210-215℃. This distribution can ensure that the film surface is free of crystal points and the flatness is ≤0.02mm / m.

[0037] The application of a high weather-resistant, low-gloss rigid polyvinyl chloride film in home decoration materials or food contact grade packaging materials. When applied, the film's weather resistance meets the following requirements: after 5 years of outdoor exposure in temperate climates, the color difference value ΔE ≤ 0.5, and there is no plasticizer migration.

[0038] The environmentally friendly, highly weather-resistant, plasticizer-free rigid polyvinyl chloride film and its preparation method provided by this invention have the following significant advantages:

[0039] I. Excellent environmental performance: Completely free of plasticizers, avoiding the leaching of harmful substances such as phthalates, and compliant with environmental standards such as RoHS and REACH; uses environmentally friendly ultraviolet absorbers (A / B / C), with no risk of heavy metal pollution, and can pass food contact grade testing.

[0040] II. Excellent weather resistance: The synergistic effect of triple UV absorbers significantly enhances resistance to UV aging; 300-hour UV aging (UVA 340nm, 0.76W / m) 2 The color difference value ΔE is ≤0.15 (gray card level 5), the tensile strength decay is ≤15%, and the outdoor service life is 15 to 20 years (3 to 4 times that of traditional PVC film).

[0041] III. High mechanical strength and processing adaptability: The plasticizer-free design maintains the rigidity of the material, while the combination of polymer modifiers ACR / ABS / MBS enhances the impact resistance; the optimized lubrication system and planetary screw extrusion process ensure stable flowability during high-temperature calendering and avoid surface defects.

[0042] IV. Simple process and controllable cost: The raw material formula is highly versatile (e.g., PVC can be selected from SG-5 / SG-7), and no special equipment is required; the planetary screw extrusion and five-roll calendering process are highly compatible, with low energy consumption, and are suitable for industrial mass production.

[0043] V. Outstanding Application Value: The film has a low gloss: the surface gloss is less than 35 degrees, making it suitable for home decoration materials (such as furniture veneers and decorative board coatings). It also has the characteristics of high weather resistance, no pollution, and low maintenance cost. The overall cost is lower than that of traditional plasticized PVC and fluorocarbon coating materials, resulting in significant economic benefits. Detailed Implementation

[0044] The embodiments of the present invention are described in detail below, and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0045] The following describes a high weather-resistant, low-gloss rigid polyvinyl chloride film according to an embodiment of the present invention, comprising the following components in parts by weight:

[0046] 100 parts of polyvinyl chloride resin;

[0047] 10 parts of matte polyvinyl chloride resin;

[0048] Stabilizer 1-2.5 parts;

[0049] Processing aids: 1-5 parts;

[0050] 5-10 parts of polymer modifier;

[0051] Internal lubricant 0.2 to 1 part;

[0052] External lubricant: 0.2–0.7 parts;

[0053] Antioxidant 0.2–0.7 parts;

[0054] Ultraviolet absorber A: 0.8–3 parts;

[0055] Ultraviolet absorber B: 0.8–3 parts;

[0056] Ultraviolet absorber C: 0.4–1.2 parts;

[0057] in:

[0058] (a) None of the raw material components contain plasticizers;

[0059] (b) The raw material components contain 10 or more parts of matte polyvinyl chloride resin, which is a low-gloss film;

[0060] (c) The ultraviolet absorbers A, B, and C respectively cover the ultraviolet bands of 250–350 nm, 280–385 nm, and 390–405 nm.

[0061] (d) The ultraviolet absorber A is a phenol triazine compound, the ultraviolet absorber B is a benzotriazole phenol compound, and the ultraviolet absorber C is a hydroxyphenyl triazine compound.

[0062] The polyvinyl chloride resin is selected from at least one of SG-7 and SG-5; the stabilizer is an organotin stabilizer or a calcium-zinc composite stabilizer.

[0063] The processing aid is selected from acrylic resin or methacrylic acid processing aid; the antioxidant is selected from powdered phosphite or liquid phenyl phosphite.

[0064] The polymer modifier is at least one of ACR, ABS, or MBS; the internal lubricant is butyl stearate or polyol complex ester; and the external lubricant is selected from calcium stearate, zinc stearate, oxidized polyethylene wax, or lignite ester wax.

[0065] The mass ratio of ultraviolet absorber A, ultraviolet absorber B, and ultraviolet absorber C is 5:5:2.

[0066] In this plan:

[0067] 1. Plasticizer-free system: Plasticizers are replaced by "polymer modifier (ACR / MBS) + composite lubrication system" - ACR can improve the melt flow of PVC, MBS can improve impact resistance; internal lubricant (butyl stearate) reduces intramolecular friction, and external lubricant (oxidized polyethylene wax) prevents material from sticking to the roller, ensuring stable processing even without plasticizers.

[0068] 2. Full-band UV protection system: Utilizing a blend of three UV absorbers to synergistically cover the entire 250–405nm wavelength band.

[0069] UV absorber A (UV-1577): preferentially absorbs the 250-350nm UVC-UVA band, avoiding the breakage of PVC molecular chains by short-wavelength ultraviolet rays;

[0070] UV absorber B (UV-928): Covers the 285-385nm UVB-UVA band, supplementing protection in the intermediate band;

[0071] UV absorber C (UV-405): Focuses on long-wave UVA at 390-405nm, reducing yellowing caused by long-term outdoor exposure.

[0072] 3. Stabilizing System: Thiol methyltin stabilizer can effectively inhibit thermal degradation during PVC processing (thermal stability time ≥30min at 160~185℃), and when combined with antioxidants (a mixture of 1010 and 168) to prevent oxidative aging, it can further extend the service life.

[0073] The present invention discloses a method for preparing a high weather-resistant, low-gloss rigid polyvinyl chloride film, comprising the following steps:

[0074] Step 1: Weigh each ingredient according to the above proportions;

[0075] Step 2: Add the raw materials to a hot mixer and mix at 80-120°C for 6-10 minutes until homogeneous;

[0076] Step 3: The mixture is pre-plasticized and extruded using a planetary screw extruder at 160–185℃, wherein the shear rate of the planetary screw extruder is 200–405 s. -1 The temperature gradient of the planetary screw extruder is: 160-170℃ in barrel zone 1, 170-180℃ in barrel zone 2, and 180-185℃ in the center screw. This gradient can prevent material from charring or insufficient pre-plasticization.

[0077] Step 4: The extruded material is further plasticized in a two-roll mill at 140-170℃, with a roll speed ratio of 1.2:1.

[0078] Step 5: The plasticized material is calendered in a five-roll calender at 190-220℃. The linear speed of the five-roll calender is 10-30 m / min. The temperature distribution of the five-roll calender is as follows: first roll 190-200℃, second roll 200-210℃, third roll 210-215℃, fourth roll 215-220℃, and fifth roll 210-215℃. This distribution ensures that the film surface is free of crystal points and the flatness is ≤0.02 mm / m.

[0079] Step 6: After stretching, cooling and shaping, trimming and winding, a film with a thickness of 0.1 to 0.15 mm is obtained.

[0080] In this plan:

[0081] 1. Planetary screw extrusion: 200-405s -1 The shear rate ensures thorough dispersion of PVC and additives, avoiding uneven plasticization caused by the absence of plasticizers; the temperature gradient design (barrel zone 160-170℃ → center screw 180-185℃) prevents material charring (shear rate > 405s). -1 (It is prone to charring).

[0082] 2. Five-roll calendering: The temperature gradient of the rolls (190~200℃ for the first roll → 210~215℃ for the fifth roll) is matched with a linear speed of 10~30m / min to ensure uniform film thickness (deviation ≤±5%) and no crystal points on the surface.

[0083] To fully illustrate the technical solution of the present invention, the following detailed description of the environmentally friendly, high weather-resistant, plasticizer-free rigid polyvinyl chloride film and its preparation method are provided in conjunction with specific embodiments. It should be noted that the raw material parts in the embodiments are all by weight and do not contain any plasticizers.

[0084] Example 1:

[0085] A high weather-resistant, low-gloss rigid polyvinyl chloride film comprises the following components by weight: 100 parts polyvinyl chloride resin (SG-7 type), 1.5 parts methyl tin mercaptan stabilizer, 4 parts acrylic processing aids, 10 parts ACR polymer modifier, 0.3 parts butyl stearate (internal lubricant), 0.25 parts oxidized polyethylene wax (external lubricant), 0.7 parts powdered phosphite (antioxidant), 3 parts UV absorber A, 3 parts UV absorber B, and 1.2 parts UV absorber C.

[0086] A method for preparing a high weather-resistant, low-gloss rigid polyvinyl chloride film includes the following steps:

[0087] Step 1: Weigh each ingredient according to the above proportions;

[0088] Step 2: Add the raw materials to a hot mixer and mix at 80-120°C for 8 minutes until homogeneous;

[0089] Step 3: The mixture is pre-plasticized and extruded through a planetary screw extruder at 160-185℃, wherein the shear rate of the planetary screw extruder is 300s. -1 The temperature gradient of the planetary screw extruder is as follows: Barrel Zone 1

[0090] 165℃, barrel zone 2 175℃, center screw 182℃;

[0091] Step 4: The extruded material is further plasticized in a 150°C two-roll mill with a roll speed ratio of 1.2:1;

[0092] Step 5: The plasticized material is calendered in a five-roll calender at 190-220℃, where the linear speed of the five-roll calender is 20m / min and the roll temperature distribution of the five-roll calender is: first roll 195℃, second roll 205℃, third roll 212℃, fourth roll 218℃, and fifth roll 215℃.

[0093] Step 6: Stretch to 1.2 times, cool water temperature 22℃, and wind up to obtain a 0.12mm thick film.

[0094] Example 2:

[0095] A high weather-resistant, low-gloss rigid polyvinyl chloride film comprises the following components by weight: 100 parts PVC powder (TL-1000 type), 1.8 parts methyl tin mercaptan stabilizer, 2 parts acrylic resin, 7.5 parts MBS polymer modifier, 0.3 parts butyl stearate (internal lubricant), 0.3 parts lignite ester wax (external lubricant), 0.4 parts powdered phosphite (antioxidant), 1.5 parts UV absorber A, 1.5 parts UV absorber B, and 0.6 parts UV absorber C.

[0096] A method for preparing a high weather-resistant, low-gloss rigid polyvinyl chloride film includes the following steps:

[0097] Step 1: Weigh each ingredient according to the above proportions;

[0098] Step 2: Add the raw materials to a hot mixer and mix at 80-120°C for 6 minutes until homogeneous;

[0099] Step 3: The mixture is pre-plasticized and extruded using a planetary screw extruder at 160–185°C, wherein the shear rate of the planetary screw extruder is 250 s. -1 The temperature gradient of the planetary screw extruder is as follows: Barrel Zone 1

[0100] 165℃, barrel zone 2 175℃, center screw 182℃;

[0101] Step 4: The extruded material is further plasticized in a 145°C two-roll mill with a roll speed ratio of 1.2:1;

[0102] Step 5: The plasticized material is calendered in a five-roll calender at 190-220℃, where the linear speed of the five-roll calender is 15m / min and the roll temperature distribution of the five-roll calender is: first roll 195℃, second roll 205℃, third roll 212℃, fourth roll 218℃, and fifth roll 215℃.

[0103] Step 6: Stretch to 1.2 times, cool water temperature 22℃, and wind up to obtain a 0.12mm thick film.

[0104] The following is a comparison table of the raw material ratios of the embodiments of the present invention and the traditional formula ratios:

[0105]

[0106]

[0107] The following is a comparison table of the performance tests of the embodiments of the present invention and traditional formulations:

[0108]

[0109]

[0110] In summary, the plasticizer-free environmental friendliness and full-band UV protection and weather resistance of Examples 1 and 2 of the present invention are significantly better than those of Comparative Example 1 (conventional plasticizer-containing film) and Comparative Example 2 (single UV absorber). Addressing the issues of plasticizer migration and insufficient weather resistance in traditional PVC films, the present invention provides an environmentally friendly, high-weather-resistant, plasticizer-free rigid PVC film and its preparation method. Through "plasticizer-free formulation design + full-band UV protection system + optimized processing technology," the environmental friendliness, weather resistance, and processability of low-gloss PVC films are synergistically improved.

[0111] The application of this invention is described as follows: This film is suitable for the field of home decoration materials (such as furniture veneers, surface coating of indoor and outdoor decorative panels), and has the characteristics of low gloss, high weather resistance, environmental protection (no plasticizer) and mechanical strength, with a service life of 15 to 20 years.

[0112] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A high-weather-resistant, low-gloss rigid polyvinyl chloride film, characterized in that: It comprises the following components in parts by weight: 100 parts of polyvinyl chloride resin; 10 parts of matte polyvinyl chloride resin Stabilizer 1-2.5 parts; Processing aids: 1-5 parts; 5-10 parts of polymer modifier; Internal lubricant 0.2~1 part; External lubricant: 0.2~0.7 parts; Antioxidant 0.2~0.7 parts; Ultraviolet absorber A: 0.8-3 parts; Ultraviolet absorber B: 0.8-3 parts; Ultraviolet absorber C: 0.4-1.2 parts; in: (a) None of the raw material components contain plasticizers; (b) The raw material components contain 10 or more parts of matte polyvinyl chloride resin, which is a low-gloss film; (c) The ultraviolet absorber A, ultraviolet absorber B, and ultraviolet absorber C respectively cover the ultraviolet bands of 250~355nm, 275~385nm, and 390~405nm; (d) The ultraviolet absorber A is a phenol triazine compound, the ultraviolet absorber B is a benzotriazole phenol compound, and the ultraviolet absorber C is a hydroxyphenyl triazine compound.

2. The high weather-resistant, low-gloss rigid polyvinyl chloride film according to claim 1, characterized in that: The polyvinyl chloride resin is selected from at least one of SG-7 and SG-5; the stabilizer is an organotin stabilizer or a calcium-zinc composite stabilizer.

3. The high weather-resistant, low-gloss rigid polyvinyl chloride film according to claim 2, characterized in that: The processing aid is selected from acrylic resin or methacrylic acid processing aid; the antioxidant is selected from powdered phosphite or liquid phenyl phosphite.

4. A high weather-resistant, low-gloss rigid polyvinyl chloride film according to any one of claims 1-3, characterized in that: The polymer modifier is at least one of ACR, ABS, or MBS; the internal lubricant is butyl stearate or polyol complex ester; and the external lubricant is selected from calcium stearate, zinc stearate, oxidized polyethylene wax, or lignite ester wax.

5. The high weather-resistant, low-gloss rigid polyvinyl chloride film according to claim 1, characterized in that: The mass ratio of ultraviolet absorber A, ultraviolet absorber B, and ultraviolet absorber C is 5:5:2, and the raw material components include 10 parts or more of matte polyvinyl chloride resin, resulting in a low-gloss film.

6. A method for preparing a high weather-resistant, low-gloss rigid polyvinyl chloride film as described in any one of claims 1-5, characterized in that: Including the following steps: Step 1: Weigh each ingredient according to the above proportions; Step 2: Add the raw materials to a hot mixer and mix at 80~120℃ for 6~10 minutes until homogeneous; Step 3: The mixture is pre-plasticized and extruded through a planetary screw extruder at 160~185℃, wherein the shear rate of the planetary screw extruder is 200~405s⁻¹; Step 4: The extruded material is further plasticized in a two-roll mill at 140~170℃, with a roll speed ratio of 1.2:

1. Step 5: The plasticized material is calendered in a five-roll calender at 190~220℃, where the linear speed of the five-roll calender is 10~30m / min; Step 6: After stretching, cooling and shaping, trimming, and winding, a film with a thickness of 0.1~0.15mm is obtained.

7. The preparation method according to claim 6, characterized in that: In step 3, the temperature gradient of the planetary screw extruder is: 170~180℃ in barrel zone 1, 150~160℃ in barrel zone 2, and 140~150℃ in the center screw. This gradient can prevent material from charring or insufficient pre-plasticization.

8. The preparation method according to claim 6, characterized in that: In step 5, the temperature distribution of the five-roll calender is as follows: first roll 190~200℃, second roll 200~210℃, third roll 210~215℃, fourth roll 215~220℃, and fifth roll 210~215℃. This distribution can ensure that the film surface is free of crystal points and the flatness is ≤0.02mm / m.

9. The application of a high weather-resistant, low-gloss rigid polyvinyl chloride film according to any one of claims 1-5 in home decoration materials or food contact grade packaging materials, characterized in that, When applied, the film's weather resistance meets the following requirements: after 5 years of outdoor exposure in temperate climates, the color difference value ΔE ≤ 0.5, and there is no plasticizer migration.

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