Water-reversible color-changing PVC material and preparation method thereof

Abstract

The application discloses a kind of water-reversible color-changing PVC materials and preparation method thereof, comprising the following weight components: PVC resin 100 parts, plasticizer 50-70 parts, calcium-zinc composite stabilizer 2-4 parts, basic metal hydroxide or basic metal oxide 2-4 parts, polyol 1-2 parts, antioxidant 1-2 parts, water-induced color change agent 2-4 parts, titanium white 2-4 parts, calcium powder 10-30 parts;Water-induced color change agent is benzotriazole compound or benzotriazole compound.Under the interaction of water-induced color change agent and basic metal hydroxide or basic metal oxide, polyol, antioxidant, the PVC material of the application can change from initial white to yellow-green in water environment, and after drying, it changes from yellow-green to white again, which expands a new idea for the study of PVC material color change.The preparation method of the application is simple in operation steps, and no toxic and harmful substances are generated in the preparation process, which meets the requirements of green processing process and energy saving and emission reduction.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a water-induced reversible color-changing PVC material and its preparation method. Background Technology

[0002] PVC, or polyvinyl chloride, is one of the world's three major general-purpose plastics with a wide range of applications. PVC products can exhibit different physical and mechanical properties depending on the additives used for their intended purpose. PVC products come in both rigid and flexible forms. Rigid PVC is primarily used for building pipes, doors, and windows. Adding plasticizers to PVC product formulations makes them softer and more elastic. Flexible PVC products can be used for pipes, cable insulation, flooring, signage, phonograph records, inflatable products, and rubber substitutes.

[0003] In recent years, organic and inorganic color-changing plastic materials have increasingly appeared on the market. These materials change color by altering their physical or chemical properties under stimuli such as temperature and light. For example, thermochromic materials change color due to electron transfer at specific temperatures, causing a change in the molecular structure of the organic compound. Existing technologies for PVC material color change often involve adding large amounts of color-changing agents to the formulation, achieving color change under specific temperature or light conditions. However, there are currently no reports on water-induced color change or water-induced reversible color change in PVC products. Therefore, this invention proposes a water-induced reversible color-changing PVC material and its preparation method, aiming to broaden the research direction for color change in PVC products. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a water-induced reversible color-changing PVC material and its preparation method. This water-induced reversible color-changing PVC material does not require specific temperature or light conditions to achieve color change. Instead, it utilizes the material's own chemical properties. Under the interaction of a water-induced color-changing agent with alkaline metal hydroxides or oxides, polyols, and antioxidants, the PVC material changes from an initial white to a yellowish-green color in an aqueous environment, and then returns to white after drying. In other words, the PVC material reacts with water to generate color-changing chemical substances, resulting in significant color change. This expands new avenues for research on PVC material color change. The preparation method of this water-induced reversible color-changing PVC material is simple to operate, requires minimal operator skill, and produces no toxic or harmful substances, meeting the requirements of green processing and energy conservation and emission reduction.

[0005] One objective of this invention is to design a water-induced reversible color-changing PVC material, comprising the following weight components: 100 parts PVC resin, 50-70 parts plasticizer, 2-4 parts calcium-zinc composite stabilizer, 2-4 parts alkaline metal hydroxide or alkaline metal oxide, 1-2 parts polyol, 1-2 parts antioxidant, 2-4 parts water-induced color-changing agent, 2-4 parts titanium dioxide, and 10-30 parts calcium powder; wherein the water-induced color-changing agent is a benzotriazole compound or a benzotriazole compound.

[0006] The preferred technical solution is that the alkaline metal hydroxide is one of calcium hydroxide, sodium hydroxide, and magnesium hydroxide, and the alkaline metal oxide is one of calcium oxide and magnesium oxide.

[0007] Another preferred technical solution is that the polyol is one of pentaerythritol, dipentaerythritol, and sorbitol.

[0008] Another preferred technical solution is that the antioxidant is one of antioxidant 1010 and antioxidant 1076.

[0009] A preferred technical solution is that the benzotriazole compound is 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol), and the benzotriazole compound is one of 2-(2-hydroxy-5-methylphenyl)benzotriazole, 3-benzotriazole-5-tert-butyl-4-hydroxyphenyl propionate, and 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole.

[0010] The second objective of this invention is to design a method for preparing a water-induced reversible color-changing PVC material. The method for preparing the above-mentioned water-induced reversible color-changing PVC material includes the following steps:

[0011] S1: According to the above weight ratio, place PVC resin, plasticizer, calcium-zinc composite stabilizer, alkaline metal hydroxide or alkaline metal oxide, polyol, antioxidant, water-induced color changer, titanium dioxide, and calcium powder in a high-speed mixer, stir and heat to 105°C, then cool and mix to 40°C to obtain a mixture.

[0012] S2: Transfer the mixture prepared in step S1 to an extruder and granulate it at 150-165℃ and 30-50 r / min to obtain water-induced reversible color-changing mixture masterbatch.

[0013] S3: Process the water-induced reversible color-changing masterbatch prepared in step S2 into water-induced reversible color-changing PVC materials of a specific shape.

[0014] The preferred technical solution is that, in step S2, the extruder temperature settings are: 150℃ in zone 1, 160℃ in zone 2, 165℃ in zone 3, 160℃ in zone 4, and 160℃ in the die.

[0015] The advantages and beneficial effects of this invention are as follows:

[0016] 1. The present invention relates to a water-induced reversible color-changing PVC material that does not require specific temperature, light, or other stimuli to achieve color change. Instead, it utilizes the material's own chemical properties. Under the interaction of a water-induced color-changing agent with alkaline metal hydroxides or oxides, polyols, and antioxidants, the PVC material can change from its initial white color to yellowish-green in an aqueous environment. After drying, it changes back from yellowish-green to white. In other words, the PVC material is colored by a chemical reaction that generates color-changing chemical substances when it comes into contact with water, and the color-changing effect is obvious, thus expanding new ideas for the research of PVC material color change.

[0017] 2. The present invention provides a water-induced reversible color-changing PVC material, wherein the water-induced color-changing agent reacts with the cations of alkaline metal hydroxides or alkaline metal oxides in water to generate a yellow-green compound, which colors the PVC material. After water loss, the color-changing chemical substance is reduced back to the original substance, and the PVC material itself changes from yellow-green to white, thus realizing the repeatability and reversibility of color change.

[0018] 3. The present invention provides a water-induced reversible color-changing PVC material, wherein the polyol can give the material better thermal stability, the antioxidant can ensure the long-term color stability and durability of the PVC material, the water-induced color-changing agent can also improve the optical stability of the material, and at the same time give the PVC material good chemical corrosion resistance.

[0019] 4. The present invention provides a method for preparing water-induced reversible color-changing PVC material. The operation steps are simple, the requirements for operators are low, and no toxic or harmful substances are generated during the preparation process, which meets the requirements of green processing and energy conservation and emission reduction. Detailed Implementation

[0020] The specific embodiments of the present invention will be further described below with reference to examples. These examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0021] A water-induced reversible color-changing PVC material, characterized in that it comprises the following weight components: 100 parts PVC resin, 50-70 parts plasticizer, 2-4 parts calcium-zinc composite stabilizer, 2-4 parts alkaline metal hydroxide or alkaline metal oxide, 1-2 parts polyol, 1-2 parts antioxidant, 2-4 parts water-induced color-changing agent, 2-4 parts titanium dioxide, and 10-30 parts calcium powder; wherein the water-induced color-changing agent is a benzotriazole compound or a benzotriazole compound.

[0022] The preferred technical solution is that the alkaline metal hydroxide is one of calcium hydroxide, sodium hydroxide, and magnesium hydroxide, and the alkaline metal oxide is one of calcium oxide and magnesium oxide.

[0023] Another preferred technical solution is that the polyol is one of pentaerythritol, dipentaerythritol, and sorbitol.

[0024] Another preferred technical solution is that the antioxidant is one of antioxidant 1010 and antioxidant 1076.

[0025] A preferred technical solution is that the benzotriazole compound is 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol), and the benzotriazole compound is one of 2-(2-hydroxy-5-methylphenyl)benzotriazole, 3-benzotriazole-5-tert-butyl-4-hydroxyphenyl propionate, and 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole.

[0026] A method for preparing a water-induced reversible color-changing PVC material, comprising the following steps:

[0027] S1: According to the above weight ratio, place PVC resin, plasticizer, calcium-zinc composite stabilizer, alkaline metal hydroxide or alkaline metal oxide, polyol, antioxidant, water-induced color changer, titanium dioxide, and calcium powder in a high-speed mixer, stir and heat to 105°C, then cool and mix to 40°C to obtain a mixture.

[0028] S2: Transfer the mixture prepared in step S1 to an extruder and granulate it at 150-165℃ and 30-50 r / min to obtain water-induced reversible color-changing mixture masterbatch.

[0029] S3: Process the water-induced reversible color-changing masterbatch prepared in step S2 into water-induced reversible color-changing PVC materials of a specific shape.

[0030] The preferred technical solution is that, in step S2, the extruder temperature settings are: 150℃ in zone 1, 160℃ in zone 2, 165℃ in zone 3, 160℃ in zone 4, and 160℃ in the die.

[0031] Example 1

[0032] A water-induced reversible color-changing PVC material, the weight composition of which is: 100g PVC resin powder, 50g plasticizer DOTP, 2g calcium-zinc composite stabilizer, 2g calcium hydroxide, 1g pentaerythritol, 1g antioxidant 1010, 2g 2,2'-methylenebis(4-tert-octyl-6-benzotriazole phenol), 2g titanium dioxide, and 10g calcium powder.

[0033] Its preparation method includes the following steps:

[0034] S1: Place 100g of PVC resin powder, 60g of plasticizer DOTP, 3g of calcium-zinc composite stabilizer, 2g of calcium hydroxide, 1g of pentaerythritol, 1g of antioxidant 1010, 2g of 2,2'-methylenebis(4-tert-octyl-6-benzotriazole phenol), 3g of titanium dioxide, and 20g of calcium powder in a high-speed mixer, stir and heat to 105℃, then cool and mix to 40℃ to obtain a mixture;

[0035] S2: Transfer the mixture prepared in step S1 to an extruder. The extruder temperature settings are: 150℃ in zone 1, 160℃ in zone 2, 165℃ in zone 3, 160℃ in zone 4, and 160℃ in the die. Extrude and granulate at 160℃ and 30r / min to obtain water-induced reversible color-changing mixture masterbatch.

[0036] S3: Place the water-induced reversible color-changing masterbatch prepared in step S2 into a flat vulcanizing machine and press it into a 1mm thick PVC sample sheet at 190℃.

[0037] Example 2

[0038] A water-induced reversible color-changing PVC material, the weight composition of which is: 100g PVC resin powder, 60g plasticizer DOTP, 3g calcium-zinc composite stabilizer, 2g calcium oxide, 1.5g dipentaerythritol, 1.5g antioxidant 1076, 3g 2-(2-hydroxy-5-methylphenyl)benzotriazole, 3g titanium dioxide, and 20g calcium powder.

[0039] Its preparation method is the same as that of the water-induced reversible color-changing PVC material in Example 1.

[0040] Example 3

[0041] A water-induced reversible color-changing PVC material, the weight composition of which is: 100g PVC resin powder, 70g plasticizer DOTP, 4g calcium-zinc composite stabilizer, 4g magnesium hydroxide, 2g sorbitol, 2g antioxidant 1010, 4g 3-benzotriazole-5-tert-butyl-4-hydroxyphenylpropionate, 4g titanium dioxide, and 30g calcium powder.

[0042] Its preparation method is the same as that of the water-induced reversible color-changing PVC material in Example 1.

[0043] Comparative Example 1

[0044] A water-induced reversible color-changing PVC material, the weight composition of which is: 100g PVC resin powder, 60g plasticizer DOTP, 3g calcium zinc composite stabilizer, 1.5g dipentaerythritol, 1.5g antioxidant 1076, 3g 2-(2-hydroxy-5-methylphenyl)benzotriazole, 3g titanium dioxide, and 20g calcium powder.

[0045] Its preparation method is the same as that of the water-induced reversible color-changing PVC material in Example 1.

[0046] Comparative Example 2

[0047] A water-induced reversible color-changing PVC material, the weight composition of which is: 100g PVC resin powder, 60g plasticizer DOTP, 3g calcium-zinc composite stabilizer, 2g calcium oxide, 1.5g dipentaerythritol, 1.5g antioxidant 1076, 3g titanium dioxide, and 20g calcium powder.

[0048] Its preparation method is the same as that of the water-induced reversible color-changing PVC material in Example 1.

[0049] Comparative Example 3

[0050] A water-induced reversible color-changing PVC material, the weight composition of which is: 100g PVC resin powder, 60g plasticizer DOTP, 3g calcium zinc composite stabilizer, 1.5g dipentaerythritol, 1.5g antioxidant 1076, 3g titanium dioxide, and 20g calcium powder.

[0051] The PVC samples prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to water-induced color change tests. The test steps were as follows:

[0052] H1: Use a colorimeter to test the initial color value of the PVC sample and record the corresponding L, a, and b values;

[0053] H2: Immerse the PVC sample in room temperature water for 8 hours, then take out the PVC sample, wipe it dry, use a colorimeter to test the color value of the PVC sample, and record the corresponding L, a, b values;

[0054] H3: After the H2 test, the PVC sample was placed in a desiccator and dried at room temperature for 4 hours. The color value of the dried PVC sample was measured with a colorimeter, and the corresponding L, a, and b values ​​were recorded.

[0055] H4: Substitute the L, a, and b values ​​tested in steps H1, H2, and H3 into Formula 1 to calculate the ΔE corresponding to the experimental PVC sample, and analyze the water-induced discoloration results of the corresponding PVC sample. The data are shown in Tables 1 to 7.

[0056]

[0057] Where: L is the lightness index, a and b are the chromaticity indices, a≥0 indicates red, a<0 ​​indicates green, b≥0 indicates yellow, and b<0 indicates blue; △L is the difference in lightness index between the experimental PVC sample and the blank control PVC sample (initial PVC sample); △a is the difference in red-green chromaticity index between the experimental PVC sample and the blank control PVC sample; △b is the difference in yellow-blue chromaticity index between the experimental PVC sample and the blank control PVC sample; ΔE is the color contrast change value between the experimental PVC sample and the blank control PVC sample. The larger ΔE is, the more obvious the color change of the PVC experimental sample compared to the blank control PVC sample. Conversely, the smaller ΔE is, the less significant the color change of the PVC experimental sample compared to the blank control PVC sample.

[0058] Table 1. Color change values ​​of the PVC samples prepared in Example 1

[0059] initial color 94.75 -0.66 1.64 -- Color after soaking for 8 hours 82.14 -11.47 36.87 38.95 Color after drying 93.75 -0.89 1.78 1.04

[0060] Table 2. Color change values ​​of the PVC samples prepared in Example 2

[0061] initial color 93.98 -0.49 1.54 -- Color after soaking for 8 hours 84.14 -10.72 33.98 35.41 Color after drying 93.11 -0.79 1.69 0.93

[0062] Table 3. Color change values ​​of the PVC samples prepared in Example 3.

[0063] initial color 93.98 -0.65 1.61 -- Color after soaking for 8 hours 85.56 -10.02 31.87 32.78 Color after drying 93.02 -0.70 1.69 0.96

[0064] Table 4 shows the color change values ​​of the PVC samples prepared in Comparative Example 1.

[0065] initial color 93.87 -0.62 1.66 -- Color after soaking for 8 hours 93.57 -0.65 1.69 0.30 Color after drying 93.81 -0.64 1.65 0.06

[0066] Table 5 shows the color change values ​​of the PVC samples prepared in Comparative Example 2.

[0067]

[0068]

[0069] Table 6 shows the color change values ​​of the PVC samples prepared in Comparative Example 3.

[0070] initial color 94.43 -0.53 1.42 -- Color after soaking for 8 hours 93.98 -0.58 1.41 0.45 Color after drying 94.40 -0.54 1.45 0.04

[0071] Table 7. Color change ΔE values ​​of PVC samples prepared in Examples 1-3 and Comparative Examples 1-3.

[0072]

[0073] As shown in Table 7, the PVC samples prepared in Examples 1-3 exhibited color changes (ΔE) of 38.95, 35.41, and 32.78 after immersion in water for 8 hours, respectively, indicating significant color changes. After drying, the color changes (ΔE) decreased to 1.04, 0.93, and 0.96, essentially restoring the initial color and demonstrating reversible color change. In contrast, the PVC samples prepared in Comparative Examples 1-3 showed color changes (ΔE) of 0.30, 0.12, and 0.45 after immersion in water for 8 hours, with almost no change in appearance. After drying, the color remained essentially consistent with the initial state. These results indicate that PVC materials only change color when exposed to water if both a water-induced color changer and an alkaline metal hydroxide (or alkaline metal oxide) are present in the formulation. Without either the water-induced color changer or the alkaline metal hydroxide (or alkaline metal oxide), the PVC material will not change color upon contact with water.

[0074] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water-induced reversible color-changing PVC material, characterized in that, The product comprises the following components by weight: 100 parts PVC resin, 50-70 parts plasticizer, 2-4 parts calcium-zinc composite stabilizer, 2-4 parts alkaline metal hydroxide or alkaline metal oxide, 1-2 parts polyol, 1-2 parts antioxidant, 2-4 parts water-induced color changer, 2-4 parts titanium dioxide, and 10-30 parts calcium powder; wherein the water-induced color changer is a benzotriazole compound or a benzotriazole compound; the alkaline metal hydroxide is one of calcium hydroxide, sodium hydroxide, and magnesium hydroxide; and the alkaline metal oxide is one of calcium oxide and magnesium oxide. One type; the polyol is one of pentaerythritol, dipentaerythritol, and sorbitol; the antioxidant is one of antioxidant 1010 and antioxidant 1076; the benzotriazole compound is 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol), and the benzotriazole compound is one of 2-(2-hydroxy-5-methylphenyl)benzotriazole, 3-benzotriazole-5-tert-butyl-4-hydroxyphenyl propionate, and 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole.

2. A method for preparing a water-induced reversible color-changing PVC material, characterized in that, The preparation of the water-induced reversible color-changing PVC material as described in claim 1 includes the following steps: S1: According to the weight ratio described in claim 1, PVC resin, plasticizer, calcium-zinc composite stabilizer, alkaline metal hydroxide or alkaline metal oxide, polyol, antioxidant, water-induced color changer, titanium dioxide, and calcium powder are placed in a high-speed mixer, stirred and heated to 105°C, and then cooled to 40°C to obtain a mixture. S2: Transfer the mixture prepared in step S1 to an extruder and granulate it at 150~165℃ and 30~50r / min to obtain water-induced reversible color-changing mixture masterbatch. S3: Process the water-induced reversible color-changing masterbatch prepared in step S2 into water-induced reversible color-changing PVC materials of a specific shape.

3. The method for preparing water-induced reversible color-changing PVC material as described in claim 2, characterized in that, In step S2, the extruder temperature settings are: Zone 1 150℃, Zone 2 160℃, Zone 3 165℃, Zone 4 160℃, and Die 160℃.

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