PVC film with improved light stability

Abstract

The invention relates to the field of PVC (polyvinyl chloride), and particularly discloses a PVC film with improved light stability, which is prepared from the following raw materials in parts by weight: 100 parts of PVC resin, 50-60 parts of plasticizer, 3-6 parts of epoxy heat-resistant plasticizer, 2-6 parts of heat stabilizer, 3-6 parts of flame retardant, 3-5 parts of chlorinated paraffin, 10-20 parts of filler, 0.1-0.5 part of ultraviolet light absorber UV-531 and 0.1-0.5 part of ultraviolet light absorber UV-326. 0.1-0.8 part of an antioxidant and 2-6 parts of rutile titanium white color paste. The PVC film provided by the invention has relatively high light stability.

Description

Technical Field

[0001] The present invention relates to the field of PVC, and more particularly, to PVC films with improved light stability. Background Art

[0002] At present, PVC artificial leather is widely used as automotive interior material, and is used to produce car seats, car door embedded panels, car roofs and sunshades. It is also used to prepare luggage, furniture leather, ball leather, etc.

[0003] PVC film products have been developed for many years and can be made into better agricultural films, raincoats, plastic shoes, soap boxes, etc. However, the problem of yellowing and aging of the products always exists, especially for light-colored products. Improving their light resistance has always been a major difficulty that has troubled researchers.

[0004] The yellowing of PVC film is affected by many factors. First, PVC resin is a heat-sensitive plastic with poor light stability. Under the action of heat and light, the side chain undergoes a dehydrochlorination reaction. For polyene structure molecules, when the number of conjugated double bonds in the main chain is not too large, a slight color difference will be produced. Hydrogen chloride will first react with the surrounding potential acid-active substances, and its conjugated double bonds will become new active positions in the PVC molecular chain. After being triggered by light to form macromolecular free radicals, PVC is easily oxidized and discolored. Secondly, there are a certain number of low molecular weight components in PVC resin, which reduces the thermal stability of the polymer. The decomposition mechanisms of PVC include free radical mechanism, ion mechanism, single molecule mechanism, etc. In addition to the stabilizer, the decomposition of PVC may also be affected by the quality of the PVC resin itself. For example, whether there are too many residual impurities in the PVC resin will reduce the stability of the polymer. The current solution to this problem is to add a certain amount of additives to the formula, but adding too much light shielding agent will reduce the toughness of the film, ultraviolet absorbers are prone to volatilization, blooming, and migration, and excited state quenchers and free radical scavengers are in conflict with some matrices, limiting the use scenarios. These additives can extend the use of PVC artificial leather to a certain extent, but the extension effect is limited and cannot meet people's current higher standards. Summary of the invention

[0005] In order to solve the problem that the PVC film has good light stability and is not prone to yellowing, the present application provides a PVC film with improved light stability.

[0006] A PVC film for improving light stability, characterized in that it comprises 100 parts of PVC resin, 50 - 60 parts of plasticizer, 3 - 6 parts of epoxy heat-resistant plasticizer, 2 - 6 parts of heat stabilizer, 3 - 6 parts of flame retardant, 3 - 5 parts of chlorinated paraffin, 10 - 20 parts of filler, 0.1 - 0.5 part of ultraviolet absorber UV-531, 0.1 - 0.5 part of ultraviolet absorber UV-326, 0.1 - 0.8 part of antioxidant, and 2 - 6 parts of rutile titanium white paste.

[0007] By adopting the above technical solution, adding a certain mass of plasticizer to form a complex with the chlorine atoms in the PVC molecules, reducing the intermolecular interaction force of the PVC molecules, thereby improving the flexibility and plasticity of the film. Adding a certain mass of epoxy heat-resistant plasticizer to improve the thermal stability of the plastic and inhibit the decomposition reaction of the film at high temperatures. The ultraviolet absorber UV-326 has relatively stable performance and strong ultraviolet absorption ability, which better improves the light stability of the prepared PVC film. The antioxidant 1010 is not easily volatile and is relatively stable in the PVC film. The antioxidants 2246, antioxidant 168, and antioxidant DCPDstyreneL are polyphenolic antioxidants with rich active groups, good anti-photoaging performance, and good compatibility with the PVC resin. Adding a certain mass of rutile titanium white paste with good fluidity to shield the film and improve the light stability. Adding a certain mass of chlorinated paraffin to improve the lubricity and adhesiveness of the film, making the prepared film more uniform and flat. Adding a certain mass of ultraviolet absorber UV-531 and ultraviolet absorber UV-326 and using them in combination to better absorb ultraviolet rays and improve the light stability of the film. Through adjusting the mass of each component in this application, it is found that the film has better light stability at this mass ratio.

[0008] In a specific feasible embodiment, the antioxidant includes one or more of antioxidant 1010, antioxidant 2246, antioxidant 168, and antioxidant DCPDstyreneL.

[0009] By adopting the above technical solution, it has a good antioxidant effect, is suitable for the film of this application, and still does not turn yellow significantly after being used for a period of time.

[0010] In a specific feasible embodiment, the antioxidant includes antioxidant DCPDstyreneL, and the mass ratio of the antioxidant DCPDstyreneL to the rutile titanium white paste is 1:(10 - 30).

[0011] The applicant found that by adopting the above technical solution, when the mass ratio of the antioxidant DCPDstyreneL to the rutile titanium white paste is 1:(10 - 30), the prepared film has better light stability and is not easily yellowed, probably because the antioxidant and shielding effects of the two on the film reach a better state at this time.

[0012] In a specific feasible embodiment, the filler includes intercalated hydrotalcite and vinylsilane-modified hollow glass microspheres.

[0013] By adopting the above technical solution, hydrotalcite has a layered structure, with high light stability and thermal stability, which provides a certain degree of shielding and protection for the film. It also has certain infrared absorption properties, further enhancing the light stability of the film. Through intercalation modification of hydrotalcite, functional guest substances are introduced into the interlayer pores and the layer distance is expanded, reducing the density of the added hydrotalcite, reducing the filling amount, improving the hydrophobicity of hydrotalcite, enhancing its dispersibility, and strengthening its compatibility and bonding force with the film matrix. The connection effect between the components inside the prepared film is better, and the internal shielding structure of the film is more excellent. By adding a certain mass of vinylsilane-modified hollow glass microspheres, the vinylsilane-modified hollow glass microspheres are more uniformly filled in the middle of the layered intercalated hydrotalcite, jointly providing shielding and heat insulation effects for the film, and further enhancing the light stability of the film.

[0014] PVC degrades by eliminating one molecule of HCl to form allyl chloride. The unstable and highly reactive allyl chloride combines with the hydrogen atom on the adjacent methylene group to form HCl and escape, forming a conjugated double bond structure. The chlorine atom adjacent to the conjugated double bond is more active, and further eliminates HCl to form a polyene structure with a larger conjugated system. The free HCl plays a catalytic acceleration role. The conjugated polyene sequence generated by the reaction is a chromophore, and the product begins to color. By modifying the hollow glass microspheres with vinylsilane, the dispersibility and compatibility of the hollow glass microspheres with the film are improved. The hollow glass microspheres are more uniformly dispersed, interspersed in the gaps shielded by hydrotalcite to isolate the entry of external heat, further reducing the degradation rate of the film and enhancing the light stability. At the same time, it may be that the prepared vinylsilane-modified hollow glass microspheres can provide addition sites to a certain extent during the degradation process, and a certain addition reaction occurs with the double bonds formed by the decomposition of PVC in the places where shielding is insufficient, terminating its further degradation. The applicant found that using vinylsilane-modified hollow glass microspheres as a heat insulation filler has a better yellowing resistance effect than other heat insulation materials.

[0015] In a specific feasible embodiment, the preparation steps of the intercalated hydrotalcite include: calcining the hydrotalcite at high temperature, then adding it to distilled water, and then adding a mixture of a certain mass of sodium dodecyl sulfate and ultraviolet absorber, stirring evenly, heating, condensing and refluxing, filtering, and drying to obtain the intercalated hydrotalcite.

[0016] By adopting the above technical solution, the intercalation step is relatively simple, the intercalation effect is good, the process requirements are low, and sodium dodecyl sulfate and the ultraviolet absorber can be inserted into the interlayer of hydrotalcite better. It not only improves the compatibility between hydrotalcite and the substrate, reduces the addition amount of hydrotalcite, but also plays a role in slowly releasing a certain mass of ultraviolet absorber, delaying the decline of light stability performance caused by the volatilization of the ultraviolet absorber.

[0017] In a specific feasible embodiment, the preparation steps of vinylsilane-modified hollow glass microspheres include: adding hollow glass microspheres into an ethanol aqueous solution, then adding vinylsilane, stirring evenly, heating, reacting, filtering by suction, washing, and drying to obtain vinylsilane-modified hollow glass microspheres.

[0018] By adopting the above technical solution, the preparation steps are relatively simple, there are more active groups connected to the surface of the hollow glass microspheres, and hydrogen bonds are formed between the modified fillers to further improve the tightness. The vinyl group can be better dispersed in the insufficient shielding part of the film along with the less dense hollow glass microspheres, blocking heat and delaying degradation, and terminating degradation.

[0019] In a specific feasible embodiment, the mass ratio of intercalated hydrotalcite to vinylsilane-modified hollow glass microspheres is (2 - 2.1):1.

[0020] By adopting the above technical solution, at this time, the protection effects such as shielding of the filler on the film are good, and the intercalated hydrotalcite and vinylsilane-modified hollow glass microspheres uniformly form a protection network in the film, and the prepared film has good light stability performance.

[0021] In a specific feasible embodiment, the average particle size of hydrotalcite is 0.4 - 0.6 μm, and the typical density of hollow glass microspheres is 0.125 g / cc.

[0022] By adopting the above technical solution, at this time, the particle size of hydrotalcite is not too large to result in poor compatibility with the film, nor too small to fail to provide good shielding and protection for the film. The hollow glass microspheres with this density are suitable for the viscosity of the film in this application, can be better dispersed and filled inside the film, and the prepared film has good light stability.

[0023] In a specific feasible embodiment, the preparation process of the PVC film includes: formulating PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, and filler according to the formula mass, then adding the remaining components, stirring evenly to obtain a mixture, and then preheating the mixture, extruding with a screw extruder, calendering, stretching, cooling, and winding to obtain the PVC film with improved light stability.

[0024] By adopting the above technical solution, the preparation method is relatively simple, the mixing is relatively uniform, the mass of the added fillers and additives is relatively small, and the prepared film has good light stability.

[0025] In a specific embodiment, the temperature of the first zone of the screw extruder is 180-185°C, the temperature of the second zone is 150-160°C, and the temperature of the third zone is 160-170°C.

[0026] By adopting the above technical scheme, the components of the film are relatively stable during the extrusion process, the obtained film is relatively uniform and smooth, without many tiny pores, and has a small surface area, which reduces the incidence of ultraviolet light. The components in the film are connected more tightly, and the internal filler provides better shielding and protection for the film, so that the obtained film has better light stability.

[0027] In summary, this application has the following beneficial effects: 1. This application can further improve the light resistance of PVC film, extend its service life, and improve the problem of yellowing of light-colored leather. The antioxidants, ultraviolet absorbers and other additives in the formula have low pollution, reduce damage to people, and improve the light resistance of PVC film.

[0028] 2. The present application adds a certain mass of sodium dodecyl sulfate and ultraviolet absorber intercalated hydrotalcite and vinyl silane modified hollow glass microspheres and limits the particle size, density and mass ratio of the two, and slowly releases the ultraviolet absorber to extend the light stability time, shield, insulate and terminate degradation. The two aspects work together to further improve the light stability of the film. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in conjunction with the examples. The rutile titanium white slurry is S209 from Shandong Wenqi New Materials Co., Ltd., the hydrotalcite is purchased from Japan Sakai Chemical HT-1, the hollow glass microspheres are purchased from 3M S15, the plasticizer is purchased from Sendi Chemical, the epoxy heat-resistant plasticizer is purchased from Shandong Wushuang Chemical, the heat stabilizer is dibenzoylmethane, the flame retardant is purchased from Guangdong Fantian Technology Co., Ltd. FT-707, and the antioxidant is DCPDstyreneL. The experimental reagents in the preparation examples and embodiments, unless otherwise specified, are all conventional commercial brands or obtained through conventional preparation processes.

[0030] Preparation Example Preparation Example 1: Intercalated hydrotalcite: The hydrotalcite was calcined at 600°C for 6 hours, then added to 120 ml of distilled water, and then a mixture of 1 g of sodium dodecyl sulfate and 2 g of ultraviolet absorber UV-531 was added, stirred evenly, heated to boiling, condensed and refluxed for 6 hours, filtered, and dried to obtain intercalated hydrotalcite.

[0031] Preparation Example 2: Intercalated hydrotalcite: The hydrotalcite was calcined at 600 °C for 6 hours, then added to 120 ml of distilled water, and 3 g of sodium dodecyl sulfate was further added. After stirring evenly, it was heated to boiling, condensed and refluxed for 6 hours, filtered, and dried to obtain the intercalated hydrotalcite.

[0032] Preparation Example 3: Vinylsilane-modified hollow glass microspheres: 30 g of hollow glass microspheres were added to 400 ml of an 80% wt ethanol aqueous solution, and 10 g of vinylsilane coupling agent A-151 was further added. Stirring was carried out at 300 revolutions per minute at 80 °C for 2 hours, followed by suction filtration, washing, and then drying at 80 °C to obtain the vinylsilane-modified hollow glass microspheres.

[0033] Preparation Example 4: Epoxysilane-modified hollow glass microspheres: 30 g of hollow glass microspheres were put into 400 ml of an 80% wt ethanol aqueous solution, and 10 g of epoxysilane coupling agent KH-560 was further added. Stirring was carried out at 300 revolutions per minute at 80 °C for 2 hours, followed by suction filtration, washing, and then drying at 80 °C to obtain the epoxysilane-modified hollow glass microspheres.

[0034] Preparation Example 5: Vinylsilane-modified glass fiber: 30 g of glass fiber was added to 400 ml of an 80% wt ethanol aqueous solution, and 10 g of vinylsilane coupling agent A-151 was further added. Stirring was carried out at 300 revolutions per minute at 80 °C for 2 hours, followed by suction filtration, washing, and then drying at 80 °C to obtain the vinylsilane-modified glass fiber. Examples

[0035] Example 1 This example contains the following raw materials by mass: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 100 g of hydrotalcite, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 8 g of antioxidant, and 60 g of rutile titanium white paste.

[0036] The preparation steps of this example are as follows: The PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, and filler were formulated according to the formula mass, and the remaining components were added, stirred evenly to obtain a mixture. Then the mixture was preheated, extruded by a screw extruder, calendered, stretched, cooled, and coiled to obtain the PVC film with improved light stability. The temperature of the first zone during extrusion by the screw extruder was 180 °C, the temperature of the second zone was 155 °C, and the temperature of the third zone was 165 °C.

[0037] Example 2 This example contains raw materials with the following masses: 1000 g of PVC resin, 600 g of plasticizer, 60 g of epoxy heat-resistant plasticizer, 60 g of heat stabilizer, 60 g of flame retardant, 30 g of chlorinated paraffin, 200 g of hydrotalcite, 1 g of ultraviolet absorber UV-531, 1 g of ultraviolet absorber UV-326, 1 g of antioxidant, and 20 g of rutile titanium white paste.

[0038] The preparation steps of this example are as follows: Weigh the PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, and filler according to the formula mass, then add the remaining components, stir evenly to obtain a mixture, then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. Among them, the temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0039] Example 3 This example contains raw materials with the following masses: 1000 g of PVC resin, 550 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 150 g of hydrotalcite, 5 g of ultraviolet absorber UV-531, 8 g of ultraviolet absorber UV-326, 8 g of antioxidant, and 60 g of rutile titanium white paste.

[0040] The preparation steps of this example are as follows: Weigh the PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, and filler according to the formula mass, then add the remaining components, stir evenly to obtain a mixture, then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. Among them, the temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0041] Example 4 This example contains raw materials with the following masses: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 100 g of hydrotalcite, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0042] The preparation steps of this example are as follows: Prepare PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler according to the formulated mass, then add the remaining components, stir evenly to obtain a mixture. Then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. The temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0043] Example 5 This example contains raw materials with the following masses: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 100 g of hydrotalcite, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 2.2 g of antioxidant, and 65.8 g of rutile titanium white paste.

[0044] The preparation steps of this example are as follows: Prepare PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler according to the formulated mass, then add the remaining components, stir evenly to obtain a mixture. Then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. The temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0045] Example 6 This example contains raw materials with the following masses: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 100 g of intercalated hydrotalcite prepared in Preparation Example 1, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0046] The preparation steps of this example are as follows: Prepare PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler according to the formulated mass, then add the remaining components, stir evenly to obtain a mixture. Then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. The temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0047] Example 7 This example contains raw materials with the following masses: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 100 g of intercalated hydrotalcite prepared in Preparation Example 2, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0048] The preparation steps of this example are as follows: Weigh the PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, and filler according to the formula mass, then add the remaining components, stir evenly to obtain a mixture. Then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. The temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0049] Example 8 This example contains raw materials with the following masses: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 50 g of intercalated hydrotalcite prepared in Preparation Example 1, 50 g of vinylsilane-modified hollow glass microspheres prepared in Preparation Example 3, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0050] The preparation steps of this example are as follows: Weigh the PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, and filler according to the formula mass, then add the remaining components, stir evenly to obtain a mixture. Then preheat the mixture, extrude it with a screw extruder, calender it, stretch it, cool it, and wind it up to obtain the PVC film with improved light stability. The temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0051] Example 9 This example contains raw materials with the following masses: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 50 g of intercalated hydrotalcite prepared in Preparation Example 1, 50 g of epoxy group-silane-modified hollow glass microspheres prepared in Preparation Example 4, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0052] The preparation steps of this example are as follows: The PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler are formulated according to the formula quality, and then the remaining components are added, stirred evenly to obtain a mixture. Then the mixture is preheated, extruded by a screw extruder, calendered, stretched, cooled, and coiled to obtain the PVC film with improved light stability. Among them, the temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0053] Example 10 This example contains the following raw materials by mass: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 50 g of the intercalated hydrotalcite prepared in Preparation Example 1, 50 g of the vinylsilane-modified glass fiber prepared in Preparation Example 5, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0054] The preparation steps of this example are as follows: The PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler are formulated according to the formula quality, and then the remaining components are added, stirred evenly to obtain a mixture. Then the mixture is preheated, extruded by a screw extruder, calendered, stretched, cooled, and coiled to obtain the PVC film with improved light stability. Among them, the temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0055] Example 11 This example contains the following raw materials by mass: 1000 g of PVC resin, 500 g of plasticizer, 30 g of epoxy heat-resistant plasticizer, 20 g of heat stabilizer, 30 g of flame retardant, 50 g of chlorinated paraffin, 66.7 g of the intercalated hydrotalcite prepared in Preparation Example 1, 33.3 g of the vinylsilane-modified hollow glass microspheres prepared in Preparation Example 3, 5 g of ultraviolet absorber UV-531, 5 g of ultraviolet absorber UV-326, 6.2 g of antioxidant, and 61.8 g of rutile titanium white paste.

[0056] The preparation steps of this example are as follows: The PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler are formulated according to the formula quality, and then the remaining components are added, stirred evenly to obtain a mixture. Then the mixture is preheated, extruded by a screw extruder, calendered, stretched, cooled, and coiled to obtain the PVC film with improved light stability. Among them, the temperature of the first zone during extrusion by the screw extruder is 180 °C, the temperature of the second zone is 155 °C, and the temperature of the third zone is 165 °C.

[0057] Comparative Example Comparative Example 1 This embodiment contains the following raw materials: 1200g of PVC resin, 500g of plasticizer, 30g of epoxy heat-resistant plasticizer, 20g of heat stabilizer, 30g of flame retardant, 50g of chlorinated paraffin, 80g of hydrotalcite, 3g of ultraviolet absorber UV-531, 3g of ultraviolet absorber UV-326, 8g of antioxidant, and 60g of rutile titanium white slurry.

[0058] The preparation steps of this embodiment are as follows: PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler are prepared according to the formula quality, and then the remaining components are added and stirred evenly to obtain a mixture, and then the mixture is preheated, extruded by a screw extruder, calendered, stretched, cooled, and coiled to obtain the PVC film with improved light stability. The temperature of the first zone of the screw extruder is 180°C, the temperature of the second zone is 155°C, and the temperature of the third zone is 165°C.

[0059] Performance test test 1: Referring to the standard GB2409, the three stimulus values ​​X, Y, and Z of different samples before and after aging for 20 days were tested using the YI-48A whiteness colorimeter. The yellowness index of the film samples before and after aging was calculated by the following formula: YI1 = [100 × (1.28X-1.06Z)] / Y, (ΔYIn = YIn-YI0, where ΔYIn is the change in the yellowness index of the sample after aging for n days; YI0 and YIn are the yellowness index values ​​of the film sample before aging and after aging for n days, respectively). The test n = 20 days. The calculated 20-day yellowing resistance results are shown in Table 1.

[0060] Test 2: Referring to the standard GB2409, the three stimulus values ​​X, Y, and Z of different samples before and after aging for 40 days were tested using the YI-48A whiteness colorimeter. The yellowness index of the film sample before and after aging was calculated by the following formula: YI2 = [100 × (1.28X-1.06Z)] / Y, (ΔYIn = YIn-YI0, where ΔYIn is the change in the yellowness index of the sample after aging for n days; YI0 and YIn are the yellowness index values ​​of the film sample before and after aging for n days, respectively). This test was conducted for n = 40 days. Then refer to the formula: conversion rate = (YI2-YI1) / YI1×100%, and the calculated 40-day yellowing resistance change rate is shown in Table 1.

[0061] Table 1 Combined with Examples 1-5, Comparative Example 1, and in combination with Table 1, the mass of each component of the present application is limited within a certain range. The antioxidant is further limited to DCPDstyreneL, and the mass ratio thereof to the rutile titanium white paste is further limited, and the prepared film has high light stability.

[0062] Combined with Example 4, Examples 6-11, and in combination with Table 1, when a certain mass of intercalated hydrotalcite and vinylsilane-modified hollow glass microspheres are added to the present application, the light stability is good, and it has both good shielding effect and high degradation termination effect. The sizes and mass ratios of the two are further limited to further improve the light stability performance of the film.

[0063] The use of this specific embodiment in the present application is only an interpretation of the present application, and it does not limit the present application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. A PVC film with improved light stability, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of PVC resin, 50-60 parts of plasticizer, 3-6 parts of epoxy heat-resistant plasticizer, 2-6 parts of heat stabilizer, 3-6 parts of flame retardant, 3-5 parts of chlorinated paraffin, 10-20 parts of filler, 0.1-0.5 parts of ultraviolet absorber UV-531, 0.1-0.5 parts of ultraviolet absorber UV-326, 0.1-0.8 parts of antioxidant and 2-6 parts of rutile titanium white slurry.

2. The PVC film with improved light stability according to claim 1, characterized in that: The antioxidant includes one or more of antioxidant 1010, antioxidant 2246, antioxidant 168, and antioxidant DCPDstyreneL.

3. The PVC film with improved light stability according to claim 2, characterized in that: The antioxidant includes the antioxidant DCPDstyreneL, and the mass ratio of the antioxidant DCPDstyreneL to the rutile titanium white slurry is 1:(10-30).

4. The PVC film with improved light stability according to claim 1, characterized in that: The filler comprises intercalated hydrotalcite and vinylsilane modified hollow glass microspheres.

5. The PVC film with improved light stability according to claim 4, characterized in that: The preparation steps of the intercalated hydrotalcite include: calcining the hydrotalcite at high temperature, then adding it into distilled water, then adding a certain mass of sodium dodecyl sulfate and a mixture of ultraviolet absorbers, stirring evenly, heating, condensing and refluxing, filtering, and drying to obtain the intercalated hydrotalcite.

6. The PVC film with improved light stability according to claim 4, characterized in that: The steps of preparing the vinyl silane modified hollow glass microspheres include: adding the hollow glass microspheres into an ethanol aqueous solution, then adding vinyl silane, stirring evenly, heating, reacting, filtering, washing, and drying to obtain the vinyl silane modified hollow glass microspheres.

7. The PVC film with improved light stability according to claim 4, characterized in that: The mass ratio of the intercalated hydrotalcite and the vinyl silane modified hollow glass microspheres is (2-2.1):

1.

8. The PVC film with improved light stability according to claim 4, characterized in that: The average particle size of the hydrotalcite is 0.4-0.6 μm, and the typical density of the hollow glass microspheres is 0.125 g / cc.

9. The PVC film with improved light stability according to claim 1, characterized in that: The preparation process of the PVC film comprises: preparing PVC resin, heat stabilizer, flame retardant, chlorinated paraffin, filler according to the formula quality, adding the remaining components, stirring evenly to obtain a mixture, and then preheating the mixture, extruding with a screw extruder, calendering, stretching, cooling, and winding to obtain the PVC film with improved light stability.

10. The PVC film with improved light stability according to claim 9, characterized in that: The temperature of the first zone of the screw extruder is 180-185°C, the temperature of the second zone is 150-160°C, and the temperature of the third zone is 160-170°C.

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