Color-adjustable artificial leather and preparation method thereof

Abstract

The present application relates to the technical field of artificial leather, and specifically discloses a color-adjustable artificial leather and a preparation method thereof. A color-adjustable artificial leather comprises a surface layer, a bottom layer and a foaming layer, wherein the surface layer comprises the following raw materials in parts by weight: 90-110 parts of polyvinyl chloride, 60-100 parts of plasticizer, 1-5 parts of heat stabilizer, 3-5 parts of surface masterbatch, and the light transmittance of the polyvinyl chloride is>85%; the bottom layer comprises the following raw materials in parts by weight: 5-10 parts of bottom masterbatch; the surface masterbatch and the bottom masterbatch belong to masterbatch of different hues or the surface masterbatch and the bottom masterbatch belong to masterbatch of different chromatograms of the same hue. A color-adjustable artificial leather of the present application, the prepared surface layer has a certain light transmission effect, and the color of the bottom layer can be shown through the surface layer, thereby prompting the artificial leather to be compounded with the bottom layer and the surface layer, showing a special and rich color effect, meeting the different visual needs of consumers for the appearance of artificial leather.

Description

Technical Field

[0001] The present application relates to the technical field of artificial leather, and more specifically, to an artificial leather with adjustable color and a preparation method thereof. Background Art

[0002] Existing artificial leather is generally made by coating a resin layer on the surface of a substrate through an adhesive agent and then processing it. It has the characteristics of being soft and wear-resistant. The color of common artificial leather is mainly added to the surface layer of artificial leather with different color masterbatches to meet people's color requirements.

[0003] However, the colors of existing artificial leathers seen by people are generally single, which cannot meet the visual needs of consumers for the appearance of artificial leather. Summary of the invention

[0004] In order to meet consumers' visual needs for the appearance of artificial leather and to make the color of artificial leather richer, the present application provides a color-adjustable artificial leather and a preparation method thereof.

[0005] The present application provides a color-adjustable artificial leather and a preparation method thereof, which adopts the following technical scheme:

[0006] In a first aspect, the present application provides a color-adjustable artificial leather, which adopts the following technical solution:

[0007] A color-adjustable artificial leather comprises a surface layer, a bottom layer and a foaming layer. The surface layer comprises the following raw materials in parts by weight: 90-110 parts of polyvinyl chloride, 60-100 parts of a plasticizer, 1-5 parts of a heat stabilizer, and 3-5 parts of a surface layer masterbatch, wherein the light transmittance of the polyvinyl chloride is greater than 85%; the bottom layer comprises the following raw materials in parts by weight: 5-10 parts of a bottom layer masterbatch; the surface layer masterbatch and the bottom layer masterbatch are masterbatch of different hues or the surface layer masterbatch and the bottom layer masterbatch are masterbatch of the same hue but different color spectra.

[0008] By adopting the above technical solution, the surface layer prepared by the high-transmittance raw material has a certain light transmittance, and at the same time, the artificial leather made by compounding the surface layer and the bottom layer can be visually observed by people after the color of the surface layer and the bottom layer are compounded, showing a special effect that cannot be achieved by adjusting the color of the surface layer alone. In addition, the surface layer and the bottom layer are compounded using surface masterbatches with different hues or with the same hue but different color spectra, which will produce the phenomenon of isochromatic heterochromaticity. The composite color of the artificial leather seen by people presents different visual perceptions under different light sources, thereby improving the richness of the color of the artificial leather. At the same time, only by adjusting the different surface layer colors and the bottom layer composites, different colors of artificial leather can be adjusted, which meets the visual needs of consumers for the appearance of artificial leather.

[0009] Preferably, the surface layer masterbatch is an organic pigment masterbatch with a particle size of 50nm-100nm.

[0010] By adopting the above technical scheme, the use of organic pigment masterbatches is beneficial to improving the light transmittance of the surface layer. At the same time, controlling the masterbatch particle size will also increase the light transmittance of the surface layer, reduce the masterbatch's obstruction to light, and further promote the underlying color to be displayed through the surface layer, thereby achieving the composite of the surface layer color and the underlying color, and improving the color richness of the artificial leather appearance.

[0011] Preferably, the foaming layer comprises the following raw materials in parts by weight: 90-110 parts of polyvinyl chloride, 60-80 parts of plasticizer, 2-3 parts of stabilizer, and 3-4 parts of foaming agent.

[0012] By adopting the above technical solution, the artificial leather is foamed to improve the softness and resilience of the artificial leather, thereby increasing people's demand for the softness of the artificial leather.

[0013] Preferably, the raw materials of the foaming layer further include 2-3 parts of nano-alumina and 1-3 parts of talcum powder.

[0014] By adopting the above technical scheme, nano-alumina in the foaming layer can improve the hardness and dimensional stability of the foaming layer, and promote the foaming layer to have a certain strength under the premise of maintaining a certain softness, reduce the volume shrinkage of the foaming layer during heating and foaming, thereby improving the dimensional stability of the artificial leather. On the other hand, nano-alumina has a certain porous structure, which can improve the air permeability of the foaming layer, thereby improving the air permeability of the artificial leather. Talcum powder added to the foaming layer can promote the foaming layer to have a certain water resistance, strength and chemical resistance, and at the same time, the magnesium oxide contained in the talcum powder structure can reduce the decomposition temperature of the foaming agent, promote the foaming effect, and increase the foaming ratio of the foaming agent, thereby improving the softness and resilience of the artificial leather.

[0015] Preferably, the foaming agent is azodicarbonamide, sodium bicarbonate and zinc stearate in a mass ratio of 1:(0.1-0.2):(0.2-0.3).

[0016] By adopting the above technical scheme, azodicarbonamide is the main foaming agent of the foaming layer, and sodium bicarbonate is an endothermic inorganic foaming agent. It balances the reaction heat in the foaming system dominated by azodicarbonamide, and balances with the large amount of heat released by the foaming of azodicarbonamide, thereby reducing the phenomenon of resin decomposition caused by excessive heat in the foaming layer. At the same time, sodium bicarbonate and azodicarbonamide are compounded to mitigate the foaming amount of azodicarbonamide, making it easier to control the foaming gas volume. Zinc stearate can improve the decomposition efficiency of azodicarbonamide, reduce the decomposition temperature of azodicarbonamide, improve the foaming efficiency of the foaming agent, reduce the degradation of the resin in the artificial leather system caused by the excessive decomposition temperature of the foaming agent, and thus improve the stability of the artificial leather.

[0017] Preferably, the sodium bicarbonate is pre-treated with salicylic acid, and the mass ratio of the sodium bicarbonate to salicylic acid is 10:(0.2-0.3).

[0018] By adopting the above technical scheme, adding an appropriate amount of weakly acidic salicylic acid to sodium bicarbonate can increase the decomposition temperature of sodium bicarbonate, promote the concentration of the decomposition temperature of sodium bicarbonate, increase the foaming ratio of sodium bicarbonate, and reduce the excessive absorption of excessive heat due to the wide decomposition temperature of sodium bicarbonate.

[0019] The carboxyl polar groups on the salicylic acid molecule can combine with alumina to form an organic film on the surface of alumina, which prevents collisions between alumina particles through steric hindrance, thereby reducing the agglomeration of alumina particles. On the other hand, salicylic acid can also modify the surface of talc powder, chemically bond the polar groups of salicylic acid to the surface of talc powder, improve the compatibility of talc powder in the foaming layer, and promote the uniform adsorption of talc powder on the surface of the foaming layer resin, thereby further improving the water resistance of artificial leather.

[0020] Preferably, the bottom layer raw material also includes 90-110 parts of polyvinyl chloride, 60-100 parts of plasticizer, and 1-5 parts of heat stabilizer.

[0021] By adopting the above technical scheme, a resin layer with a different color from the surface layer is made from the polyvinyl chloride, plasticizer and stabilizer in the bottom raw material, so that the artificial leather shows a special composite color to meet people's demand for the appearance of artificial leather.

[0022] In a second aspect, the present application provides a color-adjustable artificial leather and a preparation method thereof, which adopts the following technical solution:

[0023] A color-adjustable artificial leather and a preparation method thereof, comprising the following specific steps:

[0024] S1: Mixing polyvinyl chloride, plasticizer, heat stabilizer and surface masterbatch in the surface layer raw materials to form a surface layer slurry, coating the surface layer slurry on release paper, heating and drying to form a surface layer;

[0025] S2: Mixing polyvinyl chloride, plasticizer, heat stabilizer and base color masterbatch in the base material to form base slurry, coating the base slurry on the side of the surface layer formed in step S1 away from the release paper, heating and drying to form a base layer;

[0026] S3: mixing polyvinyl chloride, plasticizer, stabilizer and foaming agent in the foaming layer raw material to form a foaming layer slurry, coating the foaming layer slurry on the side of the bottom layer formed in step S2 away from the surface layer, heating and foaming to form a foaming layer;

[0027] S4: bonding the side of the foamed layer obtained in step S3 away from the bottom layer to the base fabric, heating and drying, and then removing the release paper to obtain color-adjustable artificial leather.

[0028] Preferably, the drying temperature in step S1 is 130°C-160°C, the drying temperature in step S2 is 150°C-170°C, the foaming temperature in step S3 is 170°C-180°C, and the drying temperature in step S4 is 120°C-160°C.

[0029] By adopting the above technical solution, the color of the surface layer of the artificial leather is compounded with the color of the bottom layer to form a special composite color. In addition, the surface layer masterbatch and the bottom layer masterbatch are respectively in different resin layers. Through the surface layer with high light transmittance, the composite color finally presented by the artificial leather presents different visual perceptions under different light sources.

[0030] Preferably, azodicarbonamide, sodium bicarbonate and zinc stearate are mixed in advance, ground for 20-30 minutes, and then sealed and stored to obtain the foaming agent.

[0031] By adopting the above technical scheme, grinding is used to promote the uniform attachment of sodium bicarbonate and zinc stearate to the surface of azodicarbonamide particles, so that azodicarbonamide, sodium bicarbonate and zinc stearate are combined with each other and uniformly dispersed in the foaming layer system.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. Since the present application has a surface layer and a bottom layer compounded with different color masterbatches, and the surface layer has a high light transmittance, the composite color of the surface layer and the bottom layer can be seen on the surface of the artificial leather, reflecting a special color that cannot be reflected by adjusting the color of the surface layer alone, and this composite color can enable the artificial leather to present different visual color differences under different light sources, meeting people's visual needs for the appearance of artificial leather.

[0034] 2. The present application further adds sodium bicarbonate and zinc stearate to the foaming agent with azodicarbonamide as the main raw material. Sodium bicarbonate can be used as an endothermic foaming agent to balance the large amount of heat released by the foaming of azodicarbonamide and reduce the degradation of the artificial leather resin layer caused by excessive temperature. Zinc stearate can reduce the decomposition temperature of azodicarbonamide and improve the foaming efficiency of azodicarbonamide. Azodicarbonamide, sodium bicarbonate and zinc stearate are synergistically compounded to reduce the decomposition temperature of azodicarbonamide and control the foaming gas volume of the foaming agent, thereby improving the toughening effect of the foaming agent on the artificial leather and promoting the artificial leather to have a certain softness and resilience. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with embodiments.

[0036] Example 1

[0037] A color-adjustable artificial leather comprises a surface layer, a bottom layer and a foaming layer. The surface layer comprises the following raw materials in parts by weight: 100 kg of polyvinyl chloride, 80 kg of plasticizer, 3 kg of stabilizer, and 4 kg of surface masterbatch; wherein the polyvinyl chloride is transparent PVC particles from Haoyuan Plastic Industry with a light transmittance of more than 90%, the plasticizer is dioctyl phthalate, and the heat stabilizer is a barium zinc stabilizer.

[0038] The bottom layer includes the following raw materials in parts by weight: 100 kg of polyvinyl chloride, 80 kg of plasticizer, 3 kg of stabilizer, and 8 kg of bottom layer masterbatch, wherein the polyvinyl chloride is polyvinyl chloride SG5 produced by Inner Mongolia Yili Chemical Industry Co., Ltd., the plasticizer is dioctyl phthalate, and the heat stabilizer is barium zinc stabilizer;

[0039] The foaming layer comprises the following raw materials in parts by weight: 100 kg of polyvinyl chloride, 70 kg of plasticizer, 2.5 kg of stabilizer and 4 kg of foaming agent, wherein the plasticizer is dioctyl phthalate, the stabilizer is potassium zinc stabilizer and the foaming agent is azodicarbonamide.

[0040] The surface masterbatch and the bottom masterbatch are of different hues. The surface masterbatch is BASF K2070, with a reddish yellow hue and a particle size of 50nm-60nm; the bottom masterbatch is BASF K8695, with a bright green hue and a particle size of 50nm-60nm.

[0041] A method for preparing color-adjustable artificial leather comprises the following specific steps:

[0042] S1: Mix the polyvinyl chloride, plasticizer, heat stabilizer and surface layer masterbatch in the surface layer raw materials, stir at a speed of 500r / min for 30min to form a surface layer slurry, apply the surface layer slurry on the release paper, heat and dry at 150°C for 55s to form a surface layer with a thickness of 0.2±0.1mm.

[0043] S2: Mix the polyvinyl chloride, plasticizer, heat stabilizer and base color masterbatch in the base raw materials, stir at a speed of 500 r / min for 30 min to form a base slurry, apply the base slurry on the side of the surface layer made in step S1 away from the release paper, heat at 160°C for 65s and dry to form a base layer, and the base layer thickness is 0.4±0.1 mm.

[0044] S3: Mix the polyvinyl chloride, plasticizer, stabilizer and foaming agent in the foaming layer raw materials, stir at a speed of 500r / min for 30min to form a foaming layer slurry, apply the foaming layer slurry on the side of the bottom layer formed in step S2 away from the surface layer, heat at 170°C for 80s to foam, and form a foaming layer.

[0045] S4: coating the foamed layer obtained in step S3 with a polyurethane adhesive on the side facing away from the bottom layer, bonding the foamed layer to the base fabric by a roller, heating at 140° C. for 80 seconds to dry, and then removing the release paper to obtain color-adjustable artificial leather.

[0046] Example 2-3

[0047] The difference between Example 2-3 and Example 1 is that the contents of the components in the artificial leather raw material are different, as shown in Table 1.

[0048] Table 1: Content of each component in artificial leather raw materials

[0049]

[0050] Example 4

[0051] The difference between Example 4 and Example 1 is that the diameter of the surface masterbatch in the artificial leather raw material is 90nm-100nm.

[0052] Example 5

[0053] The difference between Example 5 and Example 1 is that the surface masterbatch and the bottom masterbatch in the artificial leather raw material are masterbatch with the same hue but different color spectra, the surface masterbatch is pigment yellow PY128-diazo yellow, and the bottom masterbatch is pigment yellow PY154-benzimidazolone yellow.

[0054] Example 6

[0055] The difference between Example 6 and Example 1 is that the surface masterbatch in the artificial leather raw material is Runba I4920L inorganic pigment masterbatch, and the hue is reddish yellow.

[0056] Example 7

[0057] The difference between Example 7 and Example 1 is that the diameter of the surface masterbatch in the leather making raw material is 120-130 nm.

[0058] Example 8

[0059] The difference between Example 8 and Example 1 is that the raw material of the artificial leather foaming layer also includes 2.5 kg of nano-alumina and 2 kg of talcum powder, which are directly mixed and added to the raw material of the foaming layer, wherein the particle size of the nano-alumina is 20 nm, and the particle size of the talcum powder is 45 μm.

[0060] Example 9

[0061] The difference between Example 9 and Example 8 is that the amount of nano-alumina used in the raw material of the artificial leather foaming layer is 2 kg, and the amount of talcum powder used is 3 kg.

[0062] Example 10

[0063] The difference between Example 10 and Example 8 is that the amount of nano-alumina used in the raw material of the artificial leather foaming layer is 3 kg, and the amount of talcum powder used is 1 kg.

[0064] Embodiment 11

[0065] The difference between Example 11 and Example 8 is that the raw material of the foaming agent in the artificial leather foaming layer is a mixture of azodicarbonamide, sodium bicarbonate and zinc stearate, wherein the mass ratio of azodicarbonamide, sodium bicarbonate and zinc stearate is 1:0.2:0.3.

[0066] A method for preparing color-adjustable artificial leather comprises the following specific steps:

[0067] S1: Mix the polyvinyl chloride, plasticizer, heat stabilizer and surface layer masterbatch in the surface layer raw materials, stir at a speed of 500r / min for 30min to form a surface layer slurry, apply the surface layer slurry on the release paper, heat and dry at 150°C for 55s to form a surface layer with a thickness of 0.2±0.1mm.

[0068] S2: Mix the polyvinyl chloride, plasticizer, heat stabilizer and base color masterbatch in the base raw materials, stir at a speed of 500 r / min for 30 min to form a base slurry, apply the base slurry on the side of the surface layer made in step S1 away from the release paper, heat at 160°C for 65s and dry to form a base layer, and the base layer thickness is 0.4±0.1 mm.

[0069] S3: Azodicarbonamide, sodium bicarbonate and zinc stearate are mixed, and then ground for 20 minutes to obtain a foaming agent. Then, polyvinyl chloride, plasticizer, stabilizer and foaming agent in the foaming layer raw materials are mixed, and stirred at a speed of 500 r / min for 30 minutes to form a foaming layer slurry. Then, the foaming layer slurry is coated on the side of the bottom layer formed in step S2 away from the surface layer, and heated at 170°C for 80 seconds to foam to form a foaming layer.

[0070] S4: Coat the side of the foamed layer obtained in step S3 away from the bottom layer with polyurethane adhesive, bond the foamed layer to the base fabric by a roller, heat and dry at 140° C. for 80 seconds, and then remove the release paper to obtain color-adjustable artificial leather.

[0071] Example 12

[0072] The difference between Example 12 and Example 11 is that the mass ratio of azodicarbonamide, sodium bicarbonate and zinc stearate in the foaming agent raw materials in the artificial leather foaming layer is 1:0.1:0.2.

[0073] Example 13

[0074] The difference between Example 13 and Example 11 is that the mass ratio of azodicarbonamide, sodium bicarbonate and zinc stearate in the foaming agent raw materials in the artificial leather foaming layer is 1:0:0.3.

[0075] Embodiment 14

[0076] The difference between Example 14 and Example 11 is that the mass ratio of azodicarbonamide, sodium bicarbonate and zinc stearate in the foaming agent raw materials in the artificial leather foaming layer is 1:0.2:0.

[0077] Embodiment 15

[0078] The difference between Example 15 and Example 11 is that the sodium bicarbonate in the foaming agent raw material in the artificial leather foaming layer is pre-neutralized with salicylic acid, wherein the mass ratio of sodium bicarbonate to salicylic acid is 10:0.2.

[0079] A method for preparing color-adjustable artificial leather comprises the following specific steps:

[0080] S1: Mix the polyvinyl chloride, plasticizer, heat stabilizer and surface layer masterbatch in the surface layer raw materials, stir at a speed of 500r / min for 30min to form a surface layer slurry, apply the surface layer slurry on the release paper, heat and dry at 150°C for 55s to form a surface layer with a thickness of 0.2±0.1mm.

[0081] S2: Mix the polyvinyl chloride, plasticizer, heat stabilizer and base color masterbatch in the base raw materials, stir at a speed of 500 r / min for 30 min to form a base slurry, apply the base slurry on the side of the surface layer made in step S1 away from the release paper, heat at 160°C for 65s and dry to form a base layer, and the base layer thickness is 0.4±0.1 mm.

[0082] S3: salicylic acid is added to sodium bicarbonate to form a sodium bicarbonate neutralization solution, azodicarbonamide, sodium bicarbonate neutralization solution and zinc stearate are mixed, and then ground for 20 minutes to obtain a foaming agent, and then the polyvinyl chloride, plasticizer, stabilizer and foaming agent in the foaming layer raw materials are mixed, and stirred at a speed of 500r / min for 30 minutes to form a foaming layer slurry, and then the foaming layer slurry is coated on the side of the bottom layer formed in step S2 away from the surface layer, and heated at 170°C for 80s to foam to form a foaming layer.

[0083] S4: Coat the side of the foamed layer obtained in step S3 away from the bottom layer with polyurethane adhesive, bond the foamed layer to the base fabric by a roller, heat and dry at 140° C. for 80 seconds, and then remove the release paper to obtain color-adjustable artificial leather.

[0084] Example 16

[0085] The difference between Example 16 and Example 15 is that the mass ratio of sodium bicarbonate to salicylic acid in the foaming agent raw material in the artificial leather foaming layer is 10:0.1.

[0086] Comparative Example

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 1 is that the artificial leather raw material only includes a surface layer and a foaming layer.

[0089] The preparation method of artificial leather comprises the following specific steps:

[0090] S1: Mix the polyvinyl chloride, plasticizer, heat stabilizer and surface masterbatch in the surface layer raw materials, stir at a speed of 500r / min for 30min to form a surface layer slurry, wherein the plasticizer is dioctyl phthalate, and the heat stabilizer is barium zinc stabilizer. Coat the surface layer slurry on release paper, heat at 150°C for 55s and dry to form a surface layer with a thickness of 0.2±0.1mm;

[0091] S2: Mix the polyvinyl chloride, plasticizer, stabilizer and foaming agent in the foaming layer raw material, stir at a speed of 500 r / min for 30 minutes to form a foaming layer slurry, wherein the plasticizer is dioctyl phthalate, the stabilizer is potassium zinc stabilizer, and the foaming agent is azodicarbonamide, and apply the foaming layer slurry on the side of the surface layer formed in step S1 away from the release paper, heat at 170° C. for 80 seconds to foam, and form a foaming layer, and the thickness of the foaming layer is 0.4±0.1 mm;

[0092] S3: Coat the side of the foamed layer obtained in step S3 that is away from the bottom layer with polyurethane adhesive, bond the foamed layer to the base fabric by a roller, heat and dry at 140° C. for 80 seconds, and then remove the release paper to obtain color-adjustable artificial leather.

[0093] Comparative Example 2

[0094] The difference between Comparative Example 2 and Example 1 is that the surface masterbatch and the bottom masterbatch in the artificial leather raw material are masterbatch of the same color and the same color spectrum, and both the surface masterbatch and the bottom masterbatch are BASF K2070 with a reddish yellow hue.

[0095] Comparative Example 3

[0096] The difference between Comparative Example 3 and Example 1 is that the polyvinyl chloride in the surface layer of the artificial leather raw material is polyvinyl chloride SG5 produced by Inner Mongolia Yili Chemical Industry Co., Ltd.

[0097] Comparative Example 4

[0098] The difference between Comparative Example 4 and Example 1 is that the amount of the surface color masterbatch used in the surface layer of the artificial leather raw material is 10 kg.

[0099] Performance testing

[0100] After the surface layers provided in Examples 1-7 of the present application were separated from the release paper, the transmittance of the individual surface layers was tested with reference to GB / T2410-2008 "Determination of light transmittance and haze of transparent plastics". The test results showed that the transmittance of the surface layers was greater than 65%.

[0101] The following performance tests were performed on the artificial leathers provided in Examples 1-16 and Comparative Examples 1-4 of the present application. The specific test results are shown in Table 2.

[0102] Detection Methods

[0103] 1. Chromatic Aberration

[0104] Refer to QB / T 5160-2017 "Test methods for artificial leather and synthetic leather - Color measurement - Photoelectric integral colorimetry" to detect the color difference of artificial leather.

[0105] 2. Foaming ratio

[0106] The thickness of the artificial leather before and after foaming is measured, and the thickness after foaming divided by the thickness before foaming is the foaming ratio of the artificial leather.

[0107] 3. Tensile strength

[0108] The artificial leather prepared in the examples and comparative examples of the present application was subjected to performance testing in accordance with ISO 527 / 2-2012 “Determination of tensile properties of plastics”, with a tensile rate of 500 mm / min.

[0109] Table 2: Performance test data table

[0110]

[0111] As can be seen from Examples 1-5, the artificial leather prepared by the present application embodiment is compounded with the surface layer and the bottom layer, presenting a special composite color, and the color difference of the surface layer of the prepared artificial leather is small, and has good color uniformity. By controlling the transmittance of the main raw material and the usage of the surface layer masterbatch, the transmittance of the surface layer is improved, so that the bottom layer color can be displayed through the surface layer, the surface layer masterbatch and the bottom layer masterbatch belong to masterbatch of different hues or different color spectra of the same hue, and the surface of the final artificial leather presents a special composite color under different light sources, showing different visual color differences, meeting people's requirements for the appearance of artificial leather. And select organic pigment masterbatch with smaller particle size in the surface layer, further improve the transmittance of the surface layer, and promote the bottom layer color to be better displayed through the surface layer with a certain light transmission effect. In Example 6, the particle size of the surface layer masterbatch is increased, and in Example 7, the inorganic pigment masterbatch is selected in the surface layer. Although it still has a certain light transmission effect, the color effect of the prepared artificial leather is slightly worse than that of Example 1, because the tinting power of the organic pigment is good, the intensity of the reflected light is better than that of the inorganic pigment, and the transmittance of the organic pigment is higher than that of the inorganic pigment. Moreover, if the masterbatch particle size is too large, it will have a certain influence on the light transmittance of the surface layer and a certain attenuation effect on the light passing through the surface layer, thus affecting the display effect of the composite color of the artificial leather.

[0112] By comparing Comparative Example 1 with Example 1, only the surface layer is used in Comparative Example 1, and the color of the surface layer of the artificial leather finally prepared is relatively single, and it is unable to present the effect of the composite color produced in Example 1, which further illustrates that the composite color formed by the surface layer and the bottom layer is difficult to present with a single color. In Comparative Example 2, the surface layer masterbatch and the bottom layer masterbatch use the same type of masterbatch. From the test results of Comparative Example 2, it can be seen that although the color presented on the surface of the artificial leather prepared in Comparative Example 2 has a slight composite color effect, the difference between the composite color and the single surface layer color is not obvious. This may be because the hue and color spectrum of the surface layer masterbatch and the bottom layer masterbatch are exactly the same, which reduces the richness of the color presented in the end, and it may be difficult to show different visual color difference effects under different light sources.

[0113] In embodiments 8-10, nano-alumina and talcum powder are added to the raw materials of the foaming layer. Alumina and talcum powder can play a reinforcing role in the foaming layer, improve the dimensional stability of the artificial leather, and ensure that the foaming layer has a certain strength under the premise of having a certain softness. At the same time, the magnesium oxide molecules in the talcum powder structure can also reduce the decomposition temperature of the foaming agent, improve the foaming ratio, thereby improving the softness and resilience of the artificial leather. In embodiments 8-10, it can be seen from the test results that the usage of nano-alumina and talcum powder in embodiment 8 is the most suitable, because the excessive use of talcum powder and nano-alumina is prone to cause the problem of particle agglomeration, so it is also very important to control the usage of talcum powder and nano-alumina.

[0114] In Examples 11-12, sodium bicarbonate and zinc stearate are added to the foaming layer and the distribution of azodicarbonamide is strengthened as a foaming agent and added to the foaming layer. The exothermic foaming of azodicarbonamide and the endothermic foaming of sodium bicarbonate balance the heat in the foaming layer, reducing the phenomenon of excessive heat in the foaming layer causing degradation of polyvinyl chloride resin. At the same time, sodium bicarbonate can also control the foaming gas volume of azodicarbonamide, reduce the excessive foaming gas volume of azodicarbonamide affecting the forming of the foaming layer, thereby improving the better foaming forming of artificial leather, and prompting the artificial leather to maintain a certain softness and resilience. However, sodium bicarbonate is not used in Example 13. As can be seen from the test results, the foaming ratio of the foaming layer decreases, and the foaming gas volume of the foaming process of the foaming layer is also inconvenient to control, which further illustrates the promoting effect of sodium bicarbonate on the foaming layer.

[0115] Adding zinc stearate in Examples 11-12 can reduce the decomposition temperature of azodicarbonamide, improve the foaming efficiency of the foaming agent, and further improve the foaming effect of the foaming layer. Comparing the test results of Example 14 with those of Example 11, it can be seen that the foaming ratio of the foaming agent in Example 14 is worse than that in Example 11. This is because only sodium bicarbonate is added to the foaming agent to compound with azodicarbonamide, which has limited effect on reducing the decomposition temperature of azodicarbonamide, so zinc stearate is needed to further improve the foaming efficiency of azodicarbonamide.

[0116] In Examples 15-16, sodium bicarbonate is neutralized in advance with salicylic acid, which can increase the decomposition temperature of sodium bicarbonate, promote sodium bicarbonate foaming concentration, reduce sodium bicarbonate absorbing too much heat during the foaming process, and cause the phenomenon that the foaming heat of the foaming agent is not enough. At the same time, the active group of salicylic acid can be combined with the alkaline of nano-alumina to form an organic film on the surface of alumina, thereby having a steric hindrance on the surface of alumina, reducing the excessive proximity of nano-alumina particles, reducing the agglomeration of nano-alumina particles, promoting nano-alumina to be evenly distributed in the foaming layer, and further improving the strength of the foaming layer. On the other hand, salicylic acid can also produce chemical bonding with talcum powder, promote the compatibility of talcum powder with polyvinyl chloride, and promote talcum powder to be evenly adsorbed on the surface of polyvinyl chloride resin, thereby being evenly distributed in the foaming layer, and further improving the strength of the foaming layer. The addition amount of salicylic acid in Example 15 is more suitable.

[0117] In Comparative Example 1, only a single bottom layer is used, and the prepared artificial leather has a single color in appearance, and there is no difference in color under different light sources.

[0118] In Comparative Example 2, the surface masterbatch and the bottom masterbatch use the same type of masterbatch, and the appearance color of the prepared artificial leather still has a certain composite deepened color effect, but the color is relatively single, the composite effect is poor, and the color difference is not much under different light sources.

[0119] In Comparative Examples 3 and 4, the light transmittance of the polyvinyl chloride used in Comparative Example 3 is too low, and the surface masterbatch used in Comparative Example 4 is excessive. The light transmittance of the surface layers of the artificial leathers prepared in Comparative Examples 3 and 4 is tested separately. The light transmittance of the surface layers of the artificial leathers prepared in Comparative Examples 3 and 4 is less than 60%, indicating that the light transmittance of the surface layers of the artificial leathers prepared in Comparative Examples 3 and 4 is low. At the same time, in terms of the appearance of the artificial leathers prepared in Comparative Examples 3 and 4, the results of the color composite of the surface layer and the bottom layer are also significantly worse than those in Example 1, further indicating that the amount of masterbatch used and the light transmittance of the polyvinyl chloride resin will have a significant effect on the light transmittance of the surface layer, further affecting the effect of the composite color of the surface layer and the bottom layer of the artificial leather.

[0120] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A color-adjustable artificial leather, characterized in that: It comprises a surface layer, a bottom layer and a foaming layer, wherein the bottom layer is located between the surface layer and the foaming layer, and the surface layer comprises the following raw materials in parts by weight: 90-110 parts of polyvinyl chloride, 60-100 parts of plasticizer, 1-5 parts of heat stabilizer, and 3-5 parts of surface layer masterbatch, and the light transmittance of the polyvinyl chloride is greater than 85%; the bottom layer comprises the following raw materials in parts by weight: 5-10 parts of bottom layer masterbatch; the surface layer masterbatch and the bottom layer masterbatch are masterbatch of different hues or the surface layer masterbatch and the bottom layer masterbatch are masterbatch of the same hue but different color spectrum, and the surface layer masterbatch is an organic pigment masterbatch with a particle size of 50nm-100nm; The foaming layer comprises the following raw materials in parts by weight: 90-110 parts of polyvinyl chloride, 60-80 parts of plasticizer, 2-3 parts of stabilizer, 3-5 parts of foaming agent, 1-4 parts of nano-alumina, and 1-3 parts of talcum powder; the foaming agent is azodicarbonamide, sodium bicarbonate, and zinc stearate in a mass ratio of 1: (0.1-0.2): (0.2-0.3), the sodium bicarbonate is pre-treated with salicylic acid, and the mass ratio of sodium bicarbonate to salicylic acid is 10: (0.1-0.2).

2. The color-adjustable artificial leather according to claim 1, characterized in that: The bottom layer raw material also includes 90-110 parts of polyvinyl chloride, 60-100 parts of plasticizer and 1-5 parts of heat stabilizer.

3. A method for preparing the color-adjustable artificial leather according to any one of claims 1 to 2, characterized in that: The specific steps include: S1: Mixing polyvinyl chloride, plasticizer, heat stabilizer and surface masterbatch in the surface layer raw materials to form a surface layer slurry, coating the surface layer slurry on release paper, heating and drying to form a surface layer; S2: Mixing polyvinyl chloride, plasticizer, heat stabilizer and base masterbatch in the base raw material to form base slurry, coating the base slurry on the side of the surface layer formed in step S1 away from the release paper, heating and drying to form a base layer; S3: mixing polyvinyl chloride, plasticizer, stabilizer and foaming agent in the foaming layer raw material to form a foaming layer slurry, coating the foaming layer slurry on the side of the bottom layer formed in step S2 away from the surface layer, heating and foaming to form a foaming layer; S4: bonding the side of the foamed layer obtained in step S3 away from the bottom layer to the base fabric, heating and drying, and then removing the release paper to obtain color-adjustable artificial leather.

4. The method for preparing a color-adjustable artificial leather according to claim 3, characterized in that: The drying temperature in step S1 is 130°C-160°C, the drying temperature in step S2 is 150°C-170°C, the foaming temperature in step S3 is 170°C-180°C, and the drying temperature in step S4 is 120°C-160°C.

5. The method for preparing a color-adjustable artificial leather according to claim 3, characterized in that: Azodicarbonamide, sodium bicarbonate and zinc stearate are mixed in advance, ground for 20-30 minutes, and then sealed and stored to obtain a foaming agent.

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