Antifouling silicon-based polyurethane synthetic leather as well as preparation method and application thereof

Abstract

The invention discloses antifouling silicon-based polyurethane synthetic leather as well as a preparation method and application thereof. The antifouling silicon-based polyurethane synthetic leather sequentially comprises an organic silicon skin feeling layer, an organic silicon middle layer, an organic silicon bonding layer and a base cloth layer from top to bottom. According to the invention, the contents of the double-terminated monohydroxy silicone oil with the molecular weight of 4500 and the double-terminated monohydroxy silicone oil with the molecular weight of 1500 are ingeniously designed in the skin feeling layer, the organic silicon middle layer and the organic silicon bonding layer, so that the prepared synthetic leather product has excellent antifouling property and ductility (elongation at break) while good bonding performance among the layers is ensured. The prepared antifouling silicon-based polyurethane synthetic leather can be applied to processing of products such as consumer electronics all-in-one machines or protective jackets, and has wide market prospects, economic benefits, social benefits and ecological benefits.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane synthetic leather, and in particular relates to antifouling silicon-based polyurethane synthetic leather and a preparation method and application thereof. Background Art

[0002] With the advancement of science and technology and the improvement of people's living standards, consumer electronic products have entered thousands of households, and even everyone owns multiple consumer electronic products, such as smart phones, smart wearable products, tablet computers, laptops, etc. Consumer electronic products have become indispensable tools and entertainment products in people's daily lives. Due to the high frequency of daily use and high value, there is a strong demand for protective cases and covers for consumer electronic products. At present, the materials of protective cases and covers are mainly polyurethane synthetic leather, TPU, and PC. These materials often have problems such as poor yellowing performance, average hydrolysis performance, anti-fouling or stiff touch.

[0003] With the continuous improvement of social and economic levels, people have put forward higher and higher requirements for daily consumption such as food, clothing, housing and transportation, which has increased the requirements for the comfort, safety and environmental protection performance of materials, and silicone rubber products have come into being. Silicone rubber is a new type of environmentally friendly material, odorless and non-toxic. In addition to the physical properties of general polyurethane materials, silicone rubber has special touch and self-decontamination properties. It is very suitable for the application scenarios of consumer electronics. However, the surface tension and free energy of silicone rubber materials themselves are low, and the bonding performance with other substrates is poor; in addition, the main chain structure of the raw material silicone resin is mainly silicon-oxygen bonds, which makes it difficult to take into account both wear resistance and ductility; at the same time, the surface friction coefficient of silicone rubber materials is large and the wear resistance is average. These factors have affected the promotion and application of silicone rubber materials in the field of consumer electronic products and their protective covers. Summary of the invention

[0004] In view of this, the present invention uses a double-terminal monohydroxy silicone oil with a specific molecular weight, which contains a CC bond. By introducing the CC bond, the bond energy is reduced, the elongation of the silicone resin is improved, and the surface energy is improved, so that the newly synthesized resin has the delicate touch of the silicone material and excellent anti-fouling performance. At the same time, the ductility (elongation at break) is the same as or even higher than that of conventional polyurethane synthetic leather. Silicone-based composite materials meet customer needs and have broad market prospects, economic benefits, social benefits and ecological benefits.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a method for preparing antifouling silicon-based polyurethane synthetic leather, comprising the following steps:

[0007] Applying the silicone skin-feeling layer slurry on the release paper with zero gap, and drying at 120-140° C. for 3-5 minutes to form the silicone skin-feeling layer;

[0008] Coating an organic silicone intermediate layer slurry on the surface of the organic silicone skin-feeling layer with a coating gap of 0.10-0.20 mm, and drying at 120-140° C. for 5-10 minutes to form an intermediate layer;

[0009] A silicone adhesive layer is coated on the surface of the intermediate layer and bonded to the base fabric with a coating gap of 0.10-0.20 mm. The layer is dried and cooled at 120-140° C. for 5-10 minutes and then peeled off to obtain a finished product, i.e., an antifouling silicon-based consumer electronic composite material.

[0010] In a further embodiment, the skin-feeling layer slurry comprises the following proportions by weight: 60-70 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 1-5 parts of a slip agent, 1-3 parts of an isocyanate cross-linking agent, and 1-3 parts of a colorant.

[0011] In a further embodiment, the silicone intermediate layer slurry is formulated in the following proportions by weight: 30-40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 30-40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 30-40 parts of polyether polyurethane resin, 2-5 parts of isocyanate crosslinking agent, and 4-8 parts of colorant.

[0012] In a further embodiment, the silicone adhesive layer slurry is formulated in the following proportions by weight: 20-30 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 30-40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 40-50 parts of polyether polyurethane resin, and 2-5 parts of isocyanate crosslinking agent.

[0013] In a further embodiment, the base fabric is a stretch fabric or a spandex four-stretch fabric with a thickness of 0.20-0.60 mm.

[0014] In a further embodiment, the slip agent is a silicone dispersion.

[0015] In a further embodiment, the pre-baked isocyanate cross-linking agent may be an open type or a closed type.

[0016] The present invention provides an antifouling silicon-based polyurethane synthetic leather, which has a delicate touch and excellent antifouling performance. At the same time, the ductility (elongation at break) is the same as or even higher than that of conventional polyurethane synthetic leather, and can be applied to the processing of products such as all-in-one consumer electronic products or protective covers.

[0017] Compared with the existing organosilicon synthetic leather technology, the present invention has the following beneficial effects:

[0018] The double-ended monohydroxy silicone oil used in the present invention has two molecular weights, namely, double-ended monohydroxy silicone oil with a molecular weight of 1500 and double-ended monohydroxy silicone oil with a molecular weight of 4500. The siloxy groups in the double-ended monohydroxy silicone oil are present at both ends of the molecular chain. The larger the molecular weight, the lower the siloxy content, and the closer its performance is to polyurethane; conversely, the smaller the molecular weight, the higher the siloxy content, and the closer its performance is to silicone rubber. The present invention ingeniously designs the content of double-ended monohydroxy silicone oil with a molecular weight of 4500 and double-ended monohydroxy silicone oil with a molecular weight of 1500 in the skin-feeling layer, the silicone intermediate layer, and the silicone adhesive layer, while ensuring that each layer has good bonding performance, the prepared synthetic leather product has excellent anti-fouling performance and ductility (elongation at break).

[0019] Conventional silicone rubber processes in the prior art all require post-processing processes such as surface treatment to improve the touch. This patent eliminates post-processing processes such as surface treatment by adding a skin-feeling layer. It is a one-step process, which reduces post-processing processes and improves production efficiency.

[0020] The present invention adopts a cross-linking process instead of a conventional addition reaction and does not use a precious metal catalyst, which significantly reduces the production cost and also avoids the risk of the precious metal being easily deactivated. DETAILED DESCRIPTION

[0021] The present invention is described below by means of specific examples. It should be noted that the following specific examples are only for illustrative purposes and do not limit the scope of the present invention in any way. In addition, unless otherwise specified, methods without specific conditions or steps are conventional methods, and the reagents and materials used can be obtained from commercial channels.

[0022] The raw material information used in the embodiments and comparative examples is as follows:

[0023] The double-terminated monohydroxy silicone oil with a molecular weight of 4500 is Silok@8865H produced by Guangzhou Silok Polymer Co., Ltd.

[0024] The double-terminated monohydroxy silicone oil with a molecular weight of 1500 is Silok@8812F2 produced by Guangzhou Silok Polymer Co., Ltd.;

[0025] The polyether polyurethane resin is LT-50 produced by Hefei Anli New Materials Co., Ltd.

[0026] Silicone colorants were purchased from Dongguan Liangzhan Silicone Technology Co., Ltd.;

[0027] Isocyanate crosslinker XR92-200 was purchased from Stahl Fine Coatings Co., Ltd.

[0028] The slip agent is a silicone dispersion.

[0029] Example 1

[0030] The organic silicone skin-feeling layer slurry is coated on the release paper with zero gap, the drying temperature is set to a step program of 120° C., and the drying time is 5 min to obtain the organic silicone skin-feeling layer, wherein the organic silicone skin-feeling layer slurry is formulated in the following proportions by weight: 60 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 5 parts of a slip agent, 1 part of an isocyanate cross-linking agent, and 1 part of a colorant;

[0031] A 0.1 mm thick organic silicon intermediate layer slurry is coated on the surface of the organic silicon skin-feeling layer, the drying temperature is set to 120° C., and the drying time is 10 min to obtain an organic silicon intermediate layer, wherein the organic silicon intermediate layer slurry is formulated in the following proportions by weight: 30 parts of a double-terminal monohydroxy silicone oil with a molecular weight of 4500, 40 parts of a double-terminal monohydroxy silicone oil with a molecular weight of 1500, 30 parts of a polyether polyurethane resin, 5 parts of an isocyanate cross-linking agent, and 4 parts of a colorant;

[0032] A 0.1 mm thick silicone adhesive layer slurry is coated on the surface of the silicone intermediate layer, and a 0.20 mm stretch fabric is laminated to the silicone adhesive layer and then put into an oven for aging at a temperature of 120° C. for 10 min. After cooling, the leather is peeled off to obtain antifouling silicone-based polyurethane synthetic leather; wherein the silicone adhesive layer slurry is formulated in the following proportions by weight: 20 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 30 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 40 parts of polyether polyurethane resin, and 2 parts of isocyanate crosslinking agent.

[0033] Example 2

[0034] The organic silicone skin-feeling layer slurry is coated on the release paper with zero gap, the drying temperature is set to a step program of 130° C., and the drying time is 4 min to obtain the organic silicone skin-feeling layer, wherein the organic silicone skin-feeling layer slurry is formulated in the following proportions by weight: 65 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 3 parts of a slip agent, 1.5 parts of an isocyanate cross-linking agent, and 2 parts of a colorant;

[0035] A 0.15 mm thick organic silicon intermediate layer slurry is coated on the surface of the organic silicon skin-feeling layer, the drying temperature is set to 130° C., and the drying time is 8 min to obtain an organic silicon intermediate layer, wherein the organic silicon intermediate layer slurry is formulated in the following proportions by weight: 35 parts of a double-terminal monohydroxy silicone oil with a molecular weight of 4500, 35 parts of a double-terminal monohydroxy silicone oil with a molecular weight of 1500, 35 parts of a polyether polyurethane resin, 4 parts of an isocyanate cross-linking agent, and 6 parts of a colorant;

[0036] A 0.15 mm thick silicone adhesive layer slurry is coated on the surface of the silicone intermediate layer, and a 0.30 mm stretch fabric is laminated to the silicone adhesive layer and then put into an oven for aging at a temperature of 130° C. for 8 min. After cooling, the leather is peeled off to obtain antifouling silicone-based polyurethane synthetic leather; wherein the silicone adhesive layer slurry is formulated in the following proportions by weight: 25 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 35 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 45 parts of polyether polyurethane resin, and 4 parts of isocyanate crosslinking agent.

[0037] Example 3

[0038] The organic silicone skin-feeling layer slurry is coated on the release paper with zero gap, the drying temperature is set to a step program of 140° C., and the drying time is 3 min to obtain the organic silicone skin-feeling layer, wherein the organic silicone skin-feeling layer slurry is formulated in the following proportions by weight: 70 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 2 parts of a slip agent, 3 parts of an isocyanate cross-linking agent, and 3 parts of a colorant;

[0039] A 0.2 mm thick organic silicon intermediate layer slurry is coated on the surface of the organic silicon skin-feeling layer, the drying temperature is set to 140° C., and the drying time is 5 min to obtain an organic silicon intermediate layer, wherein the organic silicon intermediate layer slurry is formulated in the following proportions by weight: 40 parts of a double-terminal monohydroxy silicone oil with a molecular weight of 4500, 30 parts of a double-terminal monohydroxy silicone oil with a molecular weight of 1500, 40 parts of a polyether polyurethane resin, 3 parts of an isocyanate cross-linking agent, and 8 parts of a colorant;

[0040] A 0.1 mm thick silicone adhesive layer slurry is coated on the surface of the silicone intermediate layer, and a 0.60 mm stretch fabric is laminated to the silicone adhesive layer and then put into an oven for aging at a temperature of 140° C. for 5 min. After cooling, the leather is peeled off to obtain antifouling silicone-based polyurethane synthetic leather; wherein the silicone adhesive layer slurry is formulated in the following proportions by weight: 30 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 50 parts of polyether polyurethane resin, and 5 parts of isocyanate crosslinking agent.

[0041] Performance Test Results

[0042] Compared with silicone rubber synthetic leather prepared by conventional processes, the synthetic leather prepared by the present invention is easier to operate and has various physical properties that reach or even exceed those of conventional silicone rubber synthetic leather, especially excellent elongation and wear resistance. The physical properties of the products prepared in each embodiment and conventional silicone rubber synthetic leather are summarized in Table 1 below:

[0043] Table 1

[0044]

[0045] From the comparison of physical properties in Table 1 above, it can be seen that the anti-fouling silicon-based synthetic leather prepared by the present invention is basically similar to the physical properties of conventional silicone rubber synthetic leather, and the elongation at break is significantly better than that of conventional silicone rubber products. In addition, the production and processing of the patented product is simpler than that of conventional silicone rubber synthetic leather, does not require special equipment, does not have the problem of precious metal poisoning, and has strong operability.

[0046] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An antifouling silicon-based polyurethane synthetic leather, characterized in that: The antifouling silicon-based polyurethane synthetic leather comprises, from top to bottom, a silicone skin-feeling layer, a silicone middle layer, a silicone adhesive layer and a base fabric layer; the silicone skin-feeling layer is prepared from a silicone skin-feeling layer slurry composed of the following components in parts by weight: 60-70 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 1-5 parts of a slip agent, 1-3 parts of an isocyanate cross-linking agent, and 1-3 parts of a colorant.

2. The antifouling silicon-based polyurethane synthetic leather according to claim 1, characterized in that: The organic silicon intermediate layer is prepared from an organic silicon intermediate layer slurry composed of the following components in parts by weight: 30-40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 30-40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 30-40 parts of polyether polyurethane resin, 2-5 parts of isocyanate crosslinking agent, and 4-8 parts of colorant.

3. The antifouling silicon-based polyurethane synthetic leather according to claim 1, characterized in that: The organic silicone adhesive layer is prepared from an organic silicone adhesive layer slurry composed of the following components in parts by weight: 20-30 parts of double-terminal monohydroxy silicone oil with a molecular weight of 4500, 30-40 parts of double-terminal monohydroxy silicone oil with a molecular weight of 1500, 40-50 parts of polyether polyurethane resin, and 2-5 parts of isocyanate crosslinking agent.

4. The antifouling silicon-based polyurethane synthetic leather according to claim 1, characterized in that: The slip agent is a silicone dispersion.

5. The antifouling silicon-based polyurethane synthetic leather according to claim 1, characterized in that: The base fabric layer is basically made of stretch fabric or spandex four-stretch fabric with a thickness of 0.20-0.60 mm.

6. The antifouling silicon-based polyurethane synthetic leather according to any one of claims 1 to 5, characterized in that: The isocyanate cross-linking agent is of open type or blocked type.

7. The method for preparing the antifouling silicon-based polyurethane synthetic leather according to any one of claims 1 to 5, characterized in that: The following steps are involved: Applying the silicone skin-feeling layer slurry on the release paper with zero gap, and drying at 120-140° C. for 3-5 minutes to form the silicone skin-feeling layer; Coating an organic silicone intermediate layer slurry on the surface of the organic silicone skin-feeling layer with a coating gap of 0.10-0.20 mm, and drying at 120-140° C. for 5-10 minutes to form an intermediate layer; The surface of the intermediate layer is coated with an organic silicon adhesive layer and laminated to the base fabric with a coating gap of 0.10-0.20 mm. The layer is dried and cooled at 120-140° C. for 5-10 minutes and then peeled off to obtain a finished product.

8. Use of the antifouling silicon-based polyurethane synthetic leather according to any one of claims 1 to 5 in consumer electronic products.

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