Silicone synthetic leather and preparation process thereof

Abstract

The application discloses a kind of organic silicon synthetic leather and its preparation process, belong to the field of organic silicon synthetic leather.The synthetic leather includes base cloth, which is provided with bottom glue layer, and the bottom glue layer is provided with surface glue layer;Wherein surface glue layer and bottom glue layer are all obtained by vacuum mixing of vinyl silicone oil, modified hydrophobic white carbon black, phenyl vinyl silicone resin, hydrogen-containing silicone oil, inhibitor and catalyst.Specific preparation is first coated to surface glue layer on release paper, heated and cured, then the bottom glue layer is coated on the surface of surface glue layer, the base cloth is laminated with bottom glue layer, heated and cured, and the release paper is removed, to obtain organic silicon leather.The organic silicon synthetic leather has the advantages of wear resistance, folding resistance, tear resistance and the like.

Description

Technical Field

[0001] This invention belongs to the field of organosilicon synthetic leather technology, specifically relating to a high-efficiency, environmentally friendly, wear-resistant, and fold-resistant organosilicon synthetic leather and its preparation process. Background Technology

[0002] Silicone leather is a new type of environmentally friendly leather. It is made by combining silicone as raw material with microfiber, non-woven fabric and other substrates, and is suitable for a variety of industry applications.

[0003] CN115595800A discloses an anti-adsorption, wear-resistant, and scratch-resistant silicone leather, but its process is complex, requires numerous raw materials, and does not disclose its basic indicators such as viscosity, hardness, and elongation at break. CN114058276A discloses a solvent-free method for preparing silicone leather with high folding resistance and high wear resistance, which involves reinforcing it with methacryloyloxy MQ resin. Although the prepared silicone leather has good performance, its resin synthesis steps are complicated, making it impossible to achieve large-scale industrial production, which hinders its industrialization. Summary of the Invention

[0004] This invention provides an organosilicon synthetic leather and its preparation process. The prepared organosilicon synthetic leather has the characteristics of wear resistance, fold resistance, and tear resistance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an organosilicon synthetic leather, comprising a base fabric, on which a base adhesive layer is provided, and a top adhesive layer is provided on the base adhesive layer; by weight, the top adhesive layer comprises the following raw materials: 150-300 parts vinyl silicone oil, 10-40 parts modified hydrophobic silica, 50-200 parts phenyl vinyl silicone resin, 5-30 parts hydrogen-containing silicone oil, 0.3-1.5 parts inhibitor, and 1-10 parts catalyst; the silica-to-hydrogen ratio of the top adhesive layer is 2.5-4.5; the base adhesive layer comprises the following raw materials: 100-200 parts vinyl silicone oil, 5-30 parts modified hydrophobic silica, 10-100 parts phenyl vinyl silicone resin, 2-15 parts hydrogen-containing silicone oil, 0.2-1 parts inhibitor, and 0.5-10 parts catalyst; the silica-to-hydrogen ratio of the base adhesive layer is 6-8.

[0006] Furthermore, the vinyl silicone oil has a vinyl content of 0.1-1.5 wt% and a viscosity of 500-15000 mPa•s.

[0007] Furthermore, the hydrogen-containing silicone oil has a hydrogen content of 0.3-1 wt% and a viscosity of 30-200 mPa•s.

[0008] Furthermore, the phenyl vinyl silicone resin has a vinyl content of 0.5-2 wt% and a viscosity of 2000-80000 mPa•s.

[0009] Furthermore, the inhibitor is a vinylcycloalcohol or an ethynylcycloalcohol compound.

[0010] Furthermore, the catalyst is a platinum catalyst, a platinum-vinyl complex, or a platinum-alkynyl complex.

[0011] Furthermore, 1 to 5 parts of color paste may be added to the base adhesive layer as needed.

[0012] This invention also relates to a method for preparing the aforementioned organosilicon synthetic leather, comprising the following steps:

[0013] S1. Mix the top adhesive layer raw materials and the base adhesive layer raw materials separately to prepare the top adhesive layer slurry and the base adhesive layer slurry;

[0014] S2. Apply the adhesive layer paste to the release paper and heat to cure;

[0015] S3. Apply the base adhesive layer slurry evenly to the surface of the top adhesive layer obtained in S2, and then bond the base fabric to the base adhesive layer and heat to cure; thus, silicone synthetic leather is obtained.

[0016] Furthermore, in the preparation of the S1 topcoat slurry or bottomcoat slurry, the vinyl silicone oil, modified hydrophobic silica, phenyl vinyl silicone resin and hydrogen-containing silicone oil in the raw materials are mixed under vacuum conditions; then an inhibitor is added, and color paste is added as needed, and the mixture is mixed under vacuum; finally, a catalyst is added and mixed under vacuum to obtain the final product.

[0017] Furthermore, the heating and curing temperature is 100-130℃, and the time is 3-10 minutes.

[0018] The present invention has the following beneficial effects:

[0019] This invention uses vinyl silicone oil and phenyl vinyl silicone resin as the main raw materials. Phenyl vinyl silicone resin has good compatibility with silicone rubber and has little effect on the viscosity of liquid silicone rubber. Compared with traditional vinyl MQ resin, phenyl vinyl silicone resin has a large steric hindrance on its molecular chain, which greatly reduces the competition for reactive sites with hydrogen-containing silicone oil, thus reducing the occurrence of side reactions and competitive reactions. By combining phenyl vinyl silicone resin with silica, the vinyl groups in phenyl vinyl silicone resin undergo cross-linking reactions with silicon-hydrogen bonds, increasing the cross-linking reaction sites and improving the cross-linking density of the reaction system. When combined with silica added to the system, the silanol groups on the silica nanoparticles that are not completely shielded undergo dehydrogenation reactions with silicon-hydrogen bonds, and the extremely small particle size of fumed silica enters the reaction system chain for secondary filling and reinforcement. At this time, it works synergistically with phenyl vinyl silicone resin to reinforce the entire reaction system, thereby significantly improving the mechanical properties and stability of silicone rubber and preparing a topcoat layer and a basecoat layer with excellent performance.

[0020] The core of the entire liquid silicone rubber reaction process is the hydrosilylation reaction, which refers to the addition reaction between a silane compound and an unsaturated compound to generate an organosilicon compound. In this reaction, the silane-hydrogen bonds of the silane compound react with the double or triple bonds of the unsaturated compound. In this invention, this is the hydrosilylation reaction between hydrogen-containing silicone oil, vinyl silicone oil, and phenyl vinyl silicone resin, producing a cross-linked network, thereby significantly improving the physicochemical properties of the liquid adhesive. Therefore, the reactant ratio in this reaction system is the most crucial factor, greatly affecting the physicochemical properties of the final organosilicon leather product. This invention regulates the silane-hydrogen ratio by controlling the amount of hydrogen-containing silicone oil added, the vinyl content in the vinyl silicone oil and phenyl vinyl silicone resin, thereby controlling the silane-hydrogen ratio to obtain the most perfect cross-linked network and achieve a higher level of physicochemical properties. Since the topcoat layer needs to have good strength as a wear-resistant surface and has high transparency requirements, phenyl vinyl silicone resin with better compatibility is mainly used for reinforcement, while the basecoat layer... To connect the top adhesive layer and the base fabric, relatively inexpensive silica is used for reinforcement. This results in a difference in the crosslinking density of the hydrosilylation reaction in the top adhesive layer and the base adhesive layer formulations. The top adhesive layer has a higher vinyl content than the base adhesive layer, thus its silica-to-hydrogen ratio is lower. Extensive experimental research has shown that the silica-to-hydrogen ratio of the top adhesive layer is controlled between 2.5 and 4.5, while that of the base adhesive layer is controlled between 6 and 8. The resulting silicone leather products exhibit excellent physicochemical properties and achieve a maximum crosslinking network, thereby significantly improving product competitiveness. Detailed Implementation

[0021] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are only for illustrating the present invention and should not be regarded as limiting the scope of the present invention.

[0022] The present invention provides an organosilicon synthetic leather, comprising a base fabric (including but not limited to non-woven fabric, polyester fabric, spandex, woven fabric, knitted fabric, etc.), on which a base adhesive layer is provided, and a top adhesive layer is provided on the base adhesive layer.

[0023] By weight, the topcoat layer comprises the following raw materials: 150-300 parts vinyl silicone oil, 10-40 parts modified hydrophobic silica, 50-200 parts phenyl vinyl silicone resin, 5-30 parts hydrogen-containing silicone oil, 0.3-1.5 parts inhibitor and 1-10 parts catalyst; the silica-hydrogen ratio of the topcoat layer is 2.5-4.5, including but not limited to 2.6, 2.7, 2.8, 2.9, 3.0, 3.3, 3.5, 3.8, 4.0, 4.2 or 4.5.

[0024] The base layer comprises the following raw materials: 100-200 parts vinyl silicone oil, 5-30 parts modified hydrophobic silica, 20-100 parts phenyl vinyl silicone resin, 2-15 parts hydrogen-containing silicone oil, 0.2-1 parts inhibitor, and 0.5-10 parts catalyst. The silica-hydrogen ratio of the top layer is 6-8, including but not limited to 6.2, 6.3, 6.5, 6.7, 6.9, 7.1, 7.3, 7.4, 7.7, 7.9, or 8.0.

[0025] The modified hydrophobic silica mentioned above is a commercially available product.

[0026] The vinyl silicone oil has a vinyl content of 0.1-1.5 wt%, preferably 0.2 wt%, and a viscosity of 500-15000 mPa•s, preferably 10000 mPa.

[0027] The hydrogen-containing silicone oil has a hydrogen content of 0.3-1 wt%, preferably 0.9 wt%, and a viscosity of 30-200 mPa•s, preferably 100 mPa•s.

[0028] The phenyl vinyl silicone resin has a vinyl content of 0.5-2 wt%, preferably 1 wt%, and a viscosity of 2000-80000 mPa•s, preferably 15000 mPa•s.

[0029] Inhibitors: Vinylcycloalcohols or ethynylcycloalcohols. Catalysts: Platinum catalysts, platinum-vinyl complexes, or platinum-alkynyl complexes. 1-5 parts of color paste are added to the base coat and top coat as needed.

[0030] The specific preparation process includes the following steps:

[0031] S1. Prepare the top layer slurry and the bottom layer slurry by mixing the raw materials of the top layer and the bottom layer respectively. Specifically, the vinyl silicone oil, modified hydrophobic silica, phenyl vinyl silicone resin and hydrogen-containing silicone oil in the raw materials are mixed under vacuum conditions. Then, the inhibitor is added and the color paste is added as needed, and the mixture is mixed under vacuum. Finally, the catalyst is added and the mixture is mixed under vacuum to obtain the slurry.

[0032] S2. Apply the adhesive layer paste onto the release paper and heat at 100-130℃ for 3 minutes to cure.

[0033] S3. Apply the base adhesive layer slurry evenly to the surface of the top adhesive layer obtained in S2, and then bond the base fabric to the base adhesive layer. Heat and cure at 100-130℃ for 5 minutes to obtain the silicone synthetic leather.

[0034] The following are specific embodiments and comparative examples, and their detailed formulations are shown in Table 1.

[0035] Table 1

[0036]

[0037] The products obtained in the above embodiments and comparative examples were subjected to flexural endurance test according to QB / T 2714-2018, abrasion resistance test according to QB / T2726-2005, and elongation at break test according to HG / T 3849-2008. The results are shown in Table 2 below.

[0038] Table 2

[0039]

[0040] The silicone leathers prepared in the above examples exhibit excellent performance in terms of folding resistance, abrasion resistance, hardness, viscosity, and elongation at break. In Comparative Example 1, after replacing the phenyl vinyl silicone resin with traditional vinyl silicone resin, the competitive reaction and side reactions between the vinyl MQ resin and the hydrogen-containing silicone oil resulted in poor crosslinking and chain extension effects during high-temperature vulcanization, leading to a brittle liquid adhesive and low elongation at break, which was reflected in the damaged folding resistance and abrasion resistance test results. However, the use of phenyl vinyl silicone resin effectively solved this problem. In Comparative Example 2, the silica-hydrogen ratio of the adhesive layer in Example 1 was reduced to 1. At this time, the silica-hydrogen ratio of the adhesive layer in Example 1 was reduced to 1, which improved the crosslinking and chain extension effects of the hydroaddition reaction. Poor cross-linking effect and poor cross-linking network formation result in poor physical and chemical properties of the prepared leather, with a significant decrease in abrasion resistance and folding resistance. In Comparative Example 3, the silica-hydrogen ratio of the base adhesive layer in Example 1 was reduced to 3. At this time, the liquid adhesive of the base adhesive layer became noticeably sticky, with poor physical and chemical properties and poor cross-linking degree. Compared with Comparative Example 2, the decrease in abrasion resistance and folding resistance was even greater, which also shows that the top adhesive layer needs to have higher strength to provide physical and chemical properties such as abrasion resistance and folding resistance. In Comparative Example 4, the silica-hydrogen ratio of the top adhesive layer and the base adhesive layer in Example 1 was reduced to 1 and 3, respectively. The prepared silicone leather sample had a sticky, soft, and elastic surface with no strength or elasticity, and extremely poor abrasion resistance and folding resistance.

[0041] The comparative results above show that the silica-hydrogen ratio plays a crucial role in the reaction system of liquid adhesive for silicone leather. It can significantly affect the construction performance and physicochemical properties of the prepared silicone leather. By controlling the silica-hydrogen ratio, the optimal crosslinking network of the hydrosilylation reaction can be achieved, and the crosslinking density can be greatly improved, thereby greatly affecting the physicochemical properties of silicone leather and giving it core product competitiveness such as high wear resistance and high folding resistance.

[0042] The above embodiments describe preferred embodiments of the present invention, but the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other way. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. An organosilicon synthetic leather, characterized in that: The product includes a base fabric with a base adhesive layer and a top adhesive layer. By weight, the top adhesive layer comprises the following raw materials: 150-300 parts vinyl silicone oil, 10-40 parts modified hydrophobic silica, 50-200 parts phenyl vinyl silicone resin, 5-30 parts hydrogen-containing silicone oil, 0.3-1.5 parts inhibitor, and 1-10 parts catalyst; the silica-to-hydrogen ratio of the top adhesive layer is 2.5-4.

5. The base adhesive layer comprises the following raw materials: 100-200 parts vinyl silicone oil, 5-30 parts modified hydrophobic silica, 10-100 parts phenyl vinyl silicone resin, 2-15 parts hydrogen-containing silicone oil, 0.2-1 part inhibitor, and 0.5-10 parts catalyst; the silica-to-hydrogen ratio of the base adhesive layer is 6-8.

2. The organosilicon synthetic leather according to claim 1, characterized in that: The vinyl silicone oil has a vinyl content of 0.1-1.5 wt% and a viscosity of 500-15000 mPa•s.

3. The organosilicon synthetic leather according to claim 1, characterized in that: The hydrogen-containing silicone oil has a hydrogen content of 0.3-1 wt% and a viscosity of 30-200 mPa•s.

4. The organosilicon synthetic leather according to claim 1, characterized in that: The phenyl vinyl silicone resin has a vinyl content of 0.5-2 wt% and a viscosity of 2000-80000 mPa•s.

5. The organosilicon synthetic leather according to claim 1, characterized in that: The inhibitor is a vinylcyclool or ethynylcyclool compound.

6. The organosilicon synthetic leather according to claim 1, characterized in that: The catalyst is a platinum catalyst, a platinum-vinyl complex, or a platinum-alkynyl complex.

7. The organosilicon synthetic leather according to any one of claims 1 to 6, characterized in that: 1 to 5 parts of color paste are added to the base layer and top layer as needed.

8. The preparation process of the organosilicon synthetic leather according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Mix the top adhesive layer raw materials and the base adhesive layer raw materials separately to prepare the top adhesive layer slurry and the base adhesive layer slurry; S2. Apply the adhesive layer paste to the release paper and heat to cure; S3. Apply the base adhesive layer slurry evenly to the surface of the top adhesive layer obtained in S2, and then bond the base fabric to the base adhesive layer and heat to cure; thus, silicone synthetic leather is obtained.

9. The preparation process according to claim 8, characterized in that: When preparing the S1 topcoat layer slurry or bottomcoat layer slurry, the vinyl silicone oil, modified hydrophobic silica, phenyl vinyl silicone resin and hydrogen-containing silicone oil in the raw materials are mixed under vacuum conditions; then an inhibitor is added, and color paste is added as needed, and the mixture is mixed under vacuum; finally, a catalyst is added and mixed under vacuum to obtain the final product.

10. The preparation process according to claim 8 or 9, characterized in that: The curing temperature is 100-130℃, and the time is 3-10 minutes.

Images