Low-friction scratch-resistant master batch, polyester film and preparation method of low-friction scratch-resistant master batch

Abstract

The invention relates to the technical field of high polymer materials, and particularly provides a low-friction scratch-resistant master batch, a polyester film and a preparation method of the low-friction scratch-resistant master batch. The low-friction and scratch-resistant master batch is prepared from the following raw materials in parts by weight: 0.5 to 1.5 parts of double-end amide polysiloxane, 1 to 3 parts of an amide lubricant and 95.5 to 98.5 parts of polyethylene glycol terephthalate. According to the invention, a hydrogen bond network and a surface lubricating layer are constructed in a PET matrix through the synergistic effect of the double-end acylamino polysiloxane and the amide lubricant, so that the film has low friction coefficient, scratch resistance and excellent optical performance, and the problem that common smooth master batch is easy to bond under a high-temperature condition is solved; and the use requirements of the automotive trim on durability, aesthetic property and environmental protection property are met.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a low-friction and scratch-resistant masterbatch, a polyester film and a preparation method thereof. Background Art

[0002] With the development of the automotive industry, the performance requirements for automotive interior materials are becoming increasingly stringent. Polyethylene terephthalate (BOPET) film, due to its excellent mechanical properties, heat resistance, and dimensional stability, is widely used in applications such as dashboard coverings, door panel protective films, and seat trim. However, the dynamic coefficient of friction (μk) of traditional BOPET film is generally higher than 0.5, resulting in significant surface wear after long-term use. It also has poor scratch resistance and is prone to surface fogging. Furthermore, in high summer temperatures, traditional lubricant masterbatches easily migrate to the film surface, causing adhesion failure and friction coefficient fluctuations exceeding 30%, severely restricting its application in high-end automotive interiors.

[0003] To address these issues, existing approaches employ methods such as plasma treatment and surface coating to improve the wear and corrosion resistance of polyester film materials. However, these methods suffer from short lifespans, complex processes, high costs, and certain pollution risks. Other approaches include adding traditional lubricants (paraffin wax, polyethylene wax, stearate) and PTFE powder to reduce the friction coefficient of BOPET film. However, traditional lubricants can affect film transparency and gloss, and their acid and alkali resistance and scratch resistance still need to be improved. PTFE powder, however, offers less than ideal results due to its large particle size and poor compatibility. For example, CN103865182A utilizes a polypropylene copolymer and lubricant masterbatch. While this masterbatch reduces the friction coefficient of BOPP film to μs = 0.25, the lubricant and anti-blocking agent in the PET substrate readily separate at high temperatures, resulting in "white spots" on the film surface. The non-migrating polysiloxane masterbatch proposed in CN112980097A still faces challenges in improving its lubricity and high-temperature resistance. Therefore, developing a BOPET film with low friction coefficient and scratch resistance, and solving the problem of easy adhesion of ordinary slippery masterbatch at high temperature, is of great significance to meet the needs of automotive interior parts. Summary of the Invention

[0004] In response to the above problems, the present invention provides a low-friction and scratch-resistant masterbatch, a polyester film and a preparation method thereof. Through the synergistic effect of double-ended amide polysiloxane and amide lubricant, the film has low friction coefficient, scratch resistance and excellent optical properties.

[0005] To solve the above technical problems, the first aspect of the present application provides a low-friction scratch-resistant master batch, which comprises the following raw materials in parts by weight: 0.5-1.5 parts of double-end amide-based polysiloxane, 1-3 parts of amide lubricant, and 95.5-98.5 parts of polyethylene terephthalate; The double-end amide-based polysiloxane is prepared by acylation reaction of double-end active group polysiloxane and acryloyl chloride, has a molecular weight of 10,000-100,000 Da, and has a chemical formula of CH2CHCONH(CH2) n [Si(CH3)2O] m (CH2) n NHCOCH=CH2, wherein n=1-50 and m=50-200.

[0006] The double-end acrylamide-based polysiloxane and the amide lubricant are used as low-friction agents in the present application, the polysiloxane backbone provides a flexible molecular skeleton, the amide groups at both ends form a strong hydrogen bond network with the ester groups of the PET matrix, which ensures firm anchoring of the molecular chain, reduces phase separation, and avoids light scattering; meanwhile, the dipole interaction between the C=O double bond and the amino group of the amide lubricant forms a uniform lubricating layer on the material surface, reduces the surface roughness, and thus improves the light transmittance and reduces the haze. The synergistic effect makes the static friction coefficient of the film as low as 0.10-0.18 at room temperature, and the film still maintains stable performance at a high temperature environment of 150℃, effectively solving the problem of friction performance degradation caused by high-temperature migration of traditional lubricants. The film maintains excellent optical properties while greatly improving the wear life, and does not contain heavy metal components, which is green and environmentally friendly.

[0007] Further, the double-end amide-based polysiloxane is double-end acrylamide-based propyl polysiloxane.

[0008] Further, the preparation method of the double-end acrylamide-based propyl polysiloxane comprises the following steps: mixing a dichloromethane solution of double-end aminopropyl polysiloxane and acryloyl chloride, reacting at 25-40℃ for 3-5h, and then washing, drying, and rotary evaporation to obtain the double-end acrylamide-based propyl polysiloxane.

[0009] Further, the molar ratio of the double-end aminopropyl polysiloxane and acryloyl chloride is 1:2-2.5.

[0010] Further, the amide lubricant is at least one selected from ethylene bis-stearamide and oleic acid amide, and is preferably ethylene bis-stearamide.

[0011] In a second aspect, the present application provides a preparation method of the low-friction scratch-resistant masterbatch, comprising the following steps: adding the double-end amide-based polysiloxane, the amide-based lubricant and the polyethylene terephthalate into an extruder for blending and extrusion to obtain the low-friction scratch-resistant masterbatch.

[0012] Further, the screw rotation speed is 180-200 rpm, and the extrusion temperature is 270-280 DEG C.

[0013] In a third aspect, the present application provides a low-friction scratch-resistant polyester film, comprising the following components in percentage by mass: 10-15% of the low-friction scratch-resistant masterbatch, 80-87% of film-grade polyester chips and 3-5% of temperature-resistant masterbatch.

[0014] Further, the film-grade polyester chips have a characteristic viscosity of 0.65 dl / g, and are prepared by esterification of terephthalic acid (PTA) and ethylene glycol (EG) to generate polyester monomer polyethylene terephthalate (abbreviated as BHET), and then the BHET is subjected to polycondensation to form PET; the molten PET resin after polycondensation is filtered, cast into strips and cut into chips to form the polyester chips.

[0015] Further, the temperature-resistant masterbatch is of BZD-99 type and is purchased from Shenzhen Baizhide Plastic Technology Co., Ltd.

[0016] In a fourth aspect, the present application provides a preparation method of the low-friction scratch-resistant polyester film, comprising the following steps: The low-friction scratch-resistant masterbatch, the film-grade polyester chips and the temperature-resistant masterbatch are mixed according to the designed formula, and then are added into an extruder for melt extrusion; the melt is subjected to flow casting, two-way stretching and winding to obtain the low-friction scratch-resistant polyester film.

[0017] Further, the melt extrusion temperature is 270-280 DEG C, and the die temperature is 275-285 DEG C.

[0018] Further, in the flow casting process, the temperature of the cooling roller is 25-30 DEG C.

[0019] Further, in the two-way stretching process, the stretching ratio of the horizontal stretching is 3.0-3.6 times, the stretching ratio of the vertical stretching is 3.0-3.4 times, the temperature of the setting section is 180-223 DEG C, and the temperature of the cooling section is 40-50 DEG C.

[0020] Compared with the prior art, the present application has the following beneficial effects: The present invention constructs a hydrogen bond network and a surface lubricating layer in the PET matrix through the synergistic effect of double-ended amide polysiloxane and amide lubricant, so that the film has a low friction coefficient, scratch resistance and excellent optical properties, solves the problem that ordinary slippery masterbatch is easy to stick under high temperature conditions, and meets the durability, aesthetics and environmental protection requirements of automotive interiors. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the specific implementation methods will be briefly introduced below. Obviously, the embodiments described below are some implementation methods of the present invention. For ordinary technicians in this field, other implementation methods can be obtained based on these embodiments without paying creative work.

[0022] If specific experimental steps or conditions are not specified in the examples, the procedures or conditions of conventional experimental steps described in the literature in the field can be followed. All raw materials and instruments used are commercially available, including but not limited to those used in the examples of this application.

[0023] Example 1 This embodiment provides a low-friction and scratch-resistant masterbatch, which includes the following raw materials in parts by weight: 1 part of double-ended amide-based polysiloxane, 2 parts of amide lubricant, and 97 parts of polyethylene terephthalate.

[0024] The amide lubricant is ethylene bisstearamide, and the double-ended amide polysiloxane is double-ended acrylamidopropyl polysiloxane (n=3, m=150, molecular weight of about 48,000 Da). The preparation method comprises the following steps: A dichloromethane solution of biaminopropyl polysiloxane (35 wt% dichloromethane) and anhydrous potassium carbonate were added to a container. Acryloyl chloride (molar ratio of biaminopropyl polysiloxane to acryloyl chloride: 1:2.3) was then added at 0°C. The temperature was then raised to 35°C and incubated for 3 hours. After the reaction, the mixture was washed twice with a 5% aqueous sodium bicarbonate solution, deionized water, and saturated brine, followed by drying over anhydrous magnesium sulfate. Finally, the dichloromethane solvent was removed by rotary evaporation to obtain biacrylamidopropyl polysiloxane.

[0025] This embodiment provides a method for preparing a low-friction, scratch-resistant masterbatch, comprising the following steps: 1 part of double-ended amide-based polysiloxane, 2 parts of amide lubricant and 97 parts of polyethylene terephthalate were weighed and blended through a twin-screw extruder at a screw speed of 180 rpm and an extrusion temperature of 275° C. The mixture was granulated to obtain a low-friction and scratch-resistant masterbatch.

[0026] This embodiment provides a low-friction and scratch-resistant polyester film, which includes the following components by mass percentage: 12% low-friction and scratch-resistant masterbatch, 85% film-grade polyester chips, and 3% heat-resistant masterbatch.

[0027] The film-grade polyester chips have an intrinsic viscosity of 0.65 dl / g. They are produced by an esterification reaction between terephthalic acid (PTA) and ethylene glycol (EG) to produce the polyester monomer ethylene terephthalate (BHET). BHET is then polycondensed to produce PET. The molten PET resin after polycondensation is filtered, cast into strands, and pelletized to form polyester chips.

[0028] The heat-resistant masterbatch model is BZD-99, purchased from Shenzhen Baizhide Plastic Technology Co., Ltd.

[0029] This embodiment provides a method for preparing a low-friction, scratch-resistant polyester film, comprising the following steps: The low-friction and scratch-resistant masterbatch, film-grade polyester chips, and heat-resistant masterbatch (the mass ratio of the low-friction and scratch-resistant masterbatch, the polyester chips, and the heat-resistant masterbatch is 12:85:3) are dried and extruded through a single-screw extruder at an extrusion temperature of 280°C. The film is then cast through a die head at a die head temperature of 285°C, a cooling roller temperature of 25°C, a longitudinal stretching ratio of 3.4 times, a transverse stretching ratio of 3.6 times, a setting section temperature of 180-223°C, and a cooling section temperature of 40-50°C to obtain a low-friction and scratch-resistant polyester film with a thickness of 150 μm.

[0030] Example 2 This embodiment provides a low-friction and scratch-resistant masterbatch, which includes the following raw materials in parts by weight: 0.8 parts of double-ended amide-based polysiloxane, 1.5 parts of amide lubricant, and 97.7 parts of polyethylene terephthalate.

[0031] The amide lubricant is oleic acid amide, and the double-ended amide polysiloxane is double-ended acrylamidopropyl polysiloxane (n=3, m=120, molecular weight of about 50,000 Da). The preparation method comprises the following steps: A dichloromethane solution of biaminopropyl polysiloxane (30 wt% dichloromethane) and anhydrous potassium carbonate were added to a container. Acryloyl chloride was slowly added dropwise at 0°C (the molar ratio of biaminopropyl polysiloxane to acryloyl chloride was 1:2.1). The temperature was raised to 30°C and the reaction was maintained for 4 hours. After the reaction, the mixture was washed twice with a 5% aqueous sodium bicarbonate solution, deionized water, and saturated brine, followed by drying over anhydrous magnesium sulfate. Finally, the dichloromethane solvent was removed by rotary evaporation to obtain biacrylamidopropyl polysiloxane.

[0032] This embodiment provides a method for preparing a low-friction, scratch-resistant masterbatch, comprising the following steps: 0.8 parts of double-ended amide polysiloxane, 1.5 parts of oleamide and 97.7 parts of polyethylene terephthalate were premixed and then blended through a twin-screw extruder at a screw speed of 190 rpm, an extrusion temperature of 272° C., and a die head temperature of 278° C. to obtain a low-friction and scratch-resistant masterbatch.

[0033] This embodiment provides a low-friction, scratch-resistant polyester film comprising the following components, by mass percentage: 10% low-friction, scratch-resistant masterbatch, 87% film-grade polyester chips, and 3% heat-resistant masterbatch. The film-grade polyester chips have an intrinsic viscosity of 0.65 dl / g, and the heat-resistant masterbatch is model BZD-99.

[0034] This embodiment provides a method for preparing a low-friction, scratch-resistant polyester film, comprising the following steps: The low-friction and scratch-resistant masterbatch, film-grade polyester chips and heat-resistant masterbatch (the mass ratio of the low-friction and scratch-resistant masterbatch, the polyester chips and the heat-resistant masterbatch is 10:87:3) are dried and melt-extruded through a single-screw extruder at an extrusion temperature of 280°C. The film is then cast through a die head at a die head temperature of 282°C, a cooling roller temperature of 28°C, a longitudinal stretching ratio of 3.2 times, a transverse stretching ratio of 3.4 times, a setting section temperature of 180-223°C, and a cooling section temperature of 40-50°C to obtain a low-friction and scratch-resistant polyester film with a thickness of 150 μm.

[0035] Example 3 This embodiment provides a low-friction and scratch-resistant masterbatch, which includes the following raw materials in parts by weight: 1.2 parts of double-ended amide-based polysiloxane, 2.5 parts of amide lubricant, and 96.3 parts of polyethylene terephthalate.

[0036] The amide lubricant is ethylene bisstearamide, and the double-ended amide polysiloxane is double-ended acrylamidopropyl polysiloxane (n=5, m=150, molecular weight of about 80,000 Da). The preparation method comprises the following steps: A dichloromethane solution of double-terminal aminopropyl polysiloxane (dichloromethane dosage is 35wt%) and anhydrous potassium carbonate are added to the container, and acryloyl chloride is added at 0°C (the molar ratio of double-terminal aminopropyl polysiloxane to acryloyl chloride is 1:2.3), then the temperature is raised to 35°C and kept warm for 3 hours. After the reaction is completed, the reaction is washed twice with 5% sodium bicarbonate aqueous solution, deionized water, and saturated salt water, then dried with anhydrous magnesium sulfate, and finally the solvent dichloromethane is removed by rotary evaporation to obtain double-terminal acrylamidopropyl polysiloxane.

[0037] This embodiment provides a method for preparing a low-friction, scratch-resistant masterbatch, comprising the following steps: 1.2 parts of double-ended amide polysiloxane, 2.5 parts of ethylene bisstearamide and 96.3 parts of polyethylene terephthalate were mixed and blended through a twin-screw extruder at a screw speed of 200 rpm and an extrusion temperature of 278° C. to obtain a low-friction and scratch-resistant masterbatch.

[0038] This embodiment provides a low-friction, scratch-resistant polyester film comprising the following components, by mass percentage: 15% low-friction, scratch-resistant masterbatch, 80% film-grade polyester chips, and 5% heat-resistant masterbatch. The film-grade polyester chips have an intrinsic viscosity of 0.65 dl / g, and the heat-resistant masterbatch is model BZD-99.

[0039] This embodiment provides a method for preparing a low-friction, scratch-resistant polyester film, comprising the following steps: The low-friction and scratch-resistant masterbatch, film-grade polyester chips, and heat-resistant masterbatch (the mass ratio of the low-friction and scratch-resistant masterbatch, film-grade polyester chips, and heat-resistant masterbatch is 15:80:5) are dried and extruded through a single-screw extruder at an extrusion temperature of 275°C. The film is then cast through a die head at a die head temperature of 278°C, a cooling roller temperature of 30°C, a longitudinal stretching ratio of 3.0 times, a transverse stretching ratio of 3.6 times, a setting section temperature of 180-223°C, and a cooling section temperature of 40-50°C to obtain a low-friction and scratch-resistant polyester film with a thickness of 150 μm.

[0040] Comparative Example 1 The difference between this comparative example and Example 1 is that the polyester film comprises the following components by mass percentage: 12% polybutylene terephthalate (PBT), 85% film-grade polyester chips, and 3% heat-resistant masterbatch. Other parameters and methods are the same as those in Example 1.

[0041] Comparative Example 2 The difference between this comparative example and Example 1 is that no double-ended amide polysiloxane is added, and the low-friction and scratch-resistant masterbatch includes the following raw materials in parts by weight: 3 parts of amide lubricant and 97 parts of polyethylene terephthalate. Other parameters and methods are the same as in Example 1.

[0042] Comparative Example 3 The difference between this comparative example and Example 1 is that no amide lubricant is added, and the low-friction and scratch-resistant masterbatch comprises the following raw materials in parts by weight: 3 parts of double-ended amide polysiloxane and 97 parts of polyethylene terephthalate. Other parameters and methods are the same as in Example 1.

[0043] Comparative Example 4 The difference between this comparative example and Example 1 is that no heat-resistant masterbatch is added, and the low-friction and scratch-resistant polyester film comprises the following components by mass percentage: 15% low-friction and scratch-resistant masterbatch and 85% film-grade polyester chips. Other parameters and methods are the same as in Example 1.

[0044] Comparative Example 5 The difference between this comparative example and Example 1 is that an equal amount of molybdenum disulfide is used instead of the double-ended amide polysiloxane, and the low-friction and scratch-resistant masterbatch includes the following raw materials in parts by weight: 1 part of molybdenum disulfide, 2 parts of amide lubricant and 97 parts of polyethylene terephthalate. Other parameters and methods are the same as in Example 1.

[0045] Performance Testing 1. Friction coefficient test Experimental Method: The BOPET films prepared in Experimental Examples 1-3 and Comparative Examples 1-5 were tested according to ASTM D-1894, Standard Test Method for Coefficient of Friction of Plastic Film and Sheeting. A film-to-film method was used, with the upper film measuring 65 mm × 90 mm and the bottom film measuring 200 mm × 300 mm. The bottom film was placed on the slide and secured with a clamp. The upper film was then placed on the slider and secured with tape. The slider pin was inserted into the center of the hole in the force sensor's test arm. When placing the slider, no pre-load was applied to the sensor (the initial force was zero as indicated on the instrument display). The films were then exposed to high temperature (150°C) for a period of time, then removed from the slide and tested at room temperature using the same method. Three tests were performed using the same method, and the dynamic and static friction coefficients (μk / μs) were recorded. The results are shown in Tables 1 and 2 below.

[0046] Table 1 Dynamic / static friction coefficient data of experimental examples and comparative examples (at room temperature) Table 2 Dynamic / static friction coefficient data of experimental examples and comparative examples (at high temperature) 2. Wear resistance test Experimental Method: The polyester films prepared in the experimental and comparative examples were tested according to the standard HG-T 4303-2012, Determination of Abrasion Resistance of Polyester Film. Steel wool was secured to the 10mm diameter end of a friction hammer using a self-locking cable tie. A metering block was placed at the 12mm diameter end of the hammer to achieve the agreed-upon total weight. The hammer and steel wool were placed perpendicularly to the surface of a horizontally fixed polyester film. The hammer was moved horizontally and linearly back and forth across the same area of ​​the film surface at a speed of approximately 30mm / s, with a distance of 50mm per direction. One reciprocating stroke constituted one stroke. This was repeated three times, and the friction results on the polyester film surface were observed. The results are shown in Table 3.

[0047] Table 3 Surface friction phenomena of experimental examples and comparative examples 3. Other performance Haze: Tested in accordance with GB / T2410-2008 standard.

[0048] Gloss: According to ASTM D2457, the test was carried out at an incident angle of 60°.

[0049] The test results are shown in Table 4.

[0050] Table 4 Haze and glossiness of experimental examples and comparative examples The above data demonstrates that the embodiments of the present invention, through the synergistic effect of the dual-end amide polysiloxane and amide lubricant, achieve an ultra-low coefficient of friction (μs / μk ≤ 0.11) while maintaining low haze (≤ 3.2%) and moderate gloss (88-92 GU), and exhibit stable high-temperature performance. The environmentally friendly materials used are of great significance for meeting the demands of automotive interior components.

[0051] The present invention starts from the raw materials, imparts wear resistance to PET by changing its composition and structure, and imparts good scratch resistance to the BOPET film by redesigning the composition and structure of the base film and adopting a biaxial stretching preparation process, thereby reducing the production cost of the base film, facilitating industrial production, and having good application prospects and high economic value.

[0052] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A low friction and scratch resistant masterbatch, characterized in that: The raw materials include the following by weight: 0.5-1.5 parts of double-ended amide polysiloxane, 1-3 parts of amide lubricant and 95.5-98.5 parts of polyethylene terephthalate; The double-ended amide-based polysiloxane is prepared by acylation reaction of double-ended reactive polysiloxane and acryloyl chloride as raw materials, and has a chemical formula of CH2CHCONH(CH2)n[Si(CH3)2O]m(CH2)nNHCOCH=CH2, wherein n=1-50, m=50-200, and the molecular weight is 10,000-100,000 Da.

2. The low-friction and scratch-resistant masterbatch according to claim 1, characterized in that: The double-terminal amide polysiloxane is a double-terminal acrylamidopropyl polysiloxane.

3. The low-friction and scratch-resistant masterbatch according to claim 2, characterized in that: The preparation method of the double-ended acrylamidopropyl polysiloxane comprises the following steps: A dichloromethane solution of double-terminal aminopropyl polysiloxane and acryloyl chloride are mixed and reacted at 25-40° C. for 3-5 hours to prepare double-terminal acrylamidopropyl polysiloxane.

4. The low-friction and scratch-resistant masterbatch according to claim 3, characterized in that: The molar ratio of the double-terminated aminopropyl polysiloxane to acryloyl chloride is 1:2-2.

5.

5. The low-friction and scratch-resistant masterbatch according to claim 1, wherein: The amide lubricant is selected from at least one of ethylene bisstearamide and oleamide.

6. A method for preparing a low-friction and scratch-resistant masterbatch, characterized in that: The method comprises the following steps: adding double-ended amide-based polysiloxane, amide lubricant and polyethylene terephthalate into an extruder, blending and extruding the mixture to obtain the low-friction and scratch-resistant masterbatch.

7. A low-friction, scratch-resistant polyester film, characterized in that: The composition includes the following components by mass percentage: 10%-15% of low-friction and scratch-resistant masterbatch, 80%-87% of film-grade polyester chips and 3%-5% of heat-resistant masterbatch.

8. The low-friction, scratch-resistant polyester film according to claim 7, wherein: The heat-resistant masterbatch model is BZD-99.

9. A method for preparing the low-friction, scratch-resistant polyester film according to claim 7 or 8, characterized in that: The steps include: The low-friction and scratch-resistant masterbatch, film-grade polyester chips and heat-resistant masterbatch are mixed, added into an extruder for melt extrusion, and the melt is cast and biaxially stretched before being wound to obtain the low-friction and scratch-resistant polyester film.

10. The method for preparing a low-friction, scratch-resistant polyester film according to claim 9, wherein: The melt extrusion temperature is 270-280°C, and the die temperature is 275-285°C; and / or During the tape casting process, the temperature of the cooling roller is 25-30°C; and / or During the biaxial stretching process, the stretching ratio of the transverse stretching is 3.0-3.6 times, the stretching ratio of the longitudinal stretching is 3.0-3.4 times, the temperature of the setting section is 180-223°C, and the temperature of the cooling section is 40-50°C.

Images