Ultrathin electronic packaging leather and preparation method thereof

Abstract

The invention belongs to the technical field of packaging leather materials, and relates to ultrathin electronic packaging leather and a preparation method thereof. According to the invention, the dry PU veneering is performed on the ultrathin woven fabric, and the polyurethane resin is combined with an adaptive solvent-free manner, so that the requirement of the mobile phone rear cover with high physical property is met, meanwhile, the body structure is light, and the protection performance of the whole machine is improved. And the organic silicon antifouling layer is printed, so that the touch feeling is smooth, and meanwhile, most dirt cleaning, chemical substance corrosion resistance and the like of mobile phone application scenes in daily life are met.

Description

Technical Field

[0001] The invention belongs to the technical field of packaging leather materials and relates to an ultra-thin electronic packaging leather and a preparation method thereof. Background Art

[0002] With the rapid development of the electronics industry, the demand for packaging leather for electronic products such as mobile phone cases, tablet computers, and keyboard cases is growing. At present, mainstream terminal brands such as Huawei, Xiaomi, Honor, OPPO, and vivo have launched models with plain leather back covers. Such products have the advantages of soft texture, low weight, and no signal impact. However, the electronic packaging leather in the existing technology is usually relatively thick, which is difficult to meet the development trend of thinner and lighter electronic products.

[0003] The electronic packaging leather in the existing technology mainly has the following problems: 1. The product thickness is relatively large and cannot meet the requirements of lightweight electronic products; 2. Organic solvents such as N,N-dimethylformamide (DMF) and catalysts such as organic tin are usually used in the preparation process, which are harmful to the human body and the environment; 3. The anti-fouling performance is not ideal and it is difficult to meet the cleaning needs in daily use. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing ultra-thin electronic packaging leather, so as to solve the problems in the prior art of excessive thickness of the electronic packaging leather, environmentally unfriendly preparation process and unsatisfactory antifouling performance.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A method for preparing an ultra-thin electronic packaging leather, the method comprising the following steps:

[0007] S1. Base fabric preparation:

[0008] The base fabric layer is an ultra-thin woven fabric with polyester and spandex blended and encrypted plain weave four-way stretch, of which the polyester content accounts for 75%-90% by weight and the spandex content accounts for 10%-25% by weight;

[0009] S2, coating the surface layer slurry on the surface of the release paper, heating and drying, to obtain the packaging leather surface layer; coating the middle layer slurry on the surface layer, heating and drying, to obtain the packaging leather middle layer;

[0010] S3, the base fabric layer is compounded with the middle layer through the adhesive layer:

[0011] Apply the adhesive layer slurry to the middle layer of the packaging leather and semi-dry laminate the bottom fabric layer;

[0012] S4, putting the laminated base fabric layer with release paper into a 135°C oven for aging for 10-20 minutes, taking it out and peeling it off to obtain a PU / ultra-thin woven fabric composite packaging leather;

[0013] S5. Apply antifouling coating on the surface of PU / ultra-thin woven fabric composite packaging leather by gravure printing, with a coating amount of 20-30g / m 2 , and dried and matured at a temperature of 170℃±10℃ to form an anti-fouling layer to obtain an ultra-thin electronic packaging leather product.

[0014] The present invention uses dry PU veneer on ultra-thin woven fabric, and meets the requirements of high physical properties of mobile phone back cover by combining polycarbonate resin with solvent-free, while making the body structure lightweight and improving the protection performance of the whole machine. Printing a layer of organic silicon antifouling layer, while having a smooth touch, meets the requirements of most of the dirty cleaning and chemical corrosion resistance of mobile phone application scenarios in daily life. In terms of environmental protection, it is forbidden to use organic solvents such as N,N-dimethylformamide (DMF) and catalysts such as organic tin that are toxic and harmful to the human body.

[0015] Preferably, the ultra-thin woven fabric is polyester and spandex (30D+20D*30D+20D) or (20D+15D*20D+15D), with a gram weight of 40-60gsm and a thickness of 0.08-0.1mm; the thickness of the finished ultra-thin electronic packaging leather is 0.15-0.25mm. Due to the use of a special ultra-thin base fabric, the packaging leather obtained by the process of the present invention can meet the ultra-thin thickness requirements of electronic products.

[0016] The specifications of polyester and spandex (30D+20D*30D+20D) or (20D+15D*20D+15D) mean: the fineness of 30D filament is 30 denier polyester stretch yarn, and the fineness of 20D filament is 20 denier spandex stretch yarn; 30D+20D*30D+20D: the warp yarn raw material is 30D polyester + 20D spandex, and the weft yarn is the same as the warp; the same applies to (20D+15D*20D+15D).

[0017] Preferably, the surface slurry comprises the following components by weight: 100 parts of anionic aliphatic waterborne hydroxyl polyurethane dispersion, 0.01-0.2 parts of defoaming agent, 0.1-3 parts of crosslinking agent, 0.1-3 parts of thickener, 0.1-2 parts of leveling agent, 0.1-3 parts of silicone wear-resistant feel agent, 1-15 parts of color paste, wherein the solid content of the anionic aliphatic waterborne hydroxyl polyurethane dispersion is 35-45%, the viscosity of the surface slurry is 1000-10000cps / 25℃, and the coating amount is 100-300g / m 2 ;

[0018] Preparation of surface slurry: Add silicone wear-resistant feel agent, leveling agent and water-based color paste to anionic aliphatic water-based hydroxyl polyurethane dispersion, add defoamer while stirring, add thickener to adjust the appropriate viscosity, stir and disperse evenly, add cross-linking agent before production, stir lightly, filter, and vacuum degas.

[0019] Preferably, the intermediate layer slurry comprises the following components by weight: 100 parts of anionic aliphatic waterborne polyurethane dispersion, 0.01-0.2 parts of defoamer, 0.1-2 parts of leveling agent, 0.1-3 parts of thickener, 10-30 parts of color paste, wherein the solid content of the anionic aliphatic waterborne polyurethane dispersion is 30-60%, the viscosity of the intermediate layer slurry is 1000-10000cps / 25°C, and the coating amount is 100-300g / m 2 ;

[0020] Preparation of the middle layer slurry: Add leveling agent and water-based color paste to anionic aliphatic water-based polyurethane dispersion, add defoamer while stirring, disperse completely, add thickener to adjust the appropriate viscosity, filter, and vacuum degas.

[0021] Preferably, the adhesive layer slurry comprises the following components by weight: 100 parts of polyether polyurethane, 0.1-1 parts of dibutyltin dilaurate, 0.1-1 parts of bismuth isooctanoate, 100-140 parts of isocyanate-terminated polyurethane prepolymer, 5-30 parts of filler, a viscosity of 2000-10000cps / 25°C, and a coating amount of 100-300g / m 2 The filler is selected from one or a mixture of two or more of matting powder, aluminum hydroxide, aluminum oxide, magnesium hydroxide, zinc borate, aluminum silicate, magnesium carbonate, glass microbeads, white carbon black, silicone resin powder, silicon dioxide, calcium carbonate or magnesium oxide;

[0022] Preparation of bonding layer slurry: Take 100 parts of polyether polyurethane, add filler, dibutyltin dilaurate and bismuth isooctanoate, stir evenly to obtain solvent-free bonding layer resin; mix polyether polyurethane (polyol A component) with isocyanate-terminated polyurethane prepolymer (isocyanate B component), stir quickly to obtain bonding layer slurry.

[0023] Preferably, the antifouling layer coating comprises the following components in parts by weight: 100 parts of silicone modified polyurethane resin, 5-30 parts of high silicon modified waterborne polyurethane resin, 0.1-10 parts of acid catalyst, and 0.1-5 parts of isocyanate crosslinking agent; the viscosity of the antifouling layer coating is 600-800cps / 23°C.

[0024] Preferably, in the antifouling layer coating, the platinum catalyst is selected from one or more of chloroplatinic acid-divinyltetramethyldisiloxane complex, chloroplatinic acid-1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane or chloroplatinic acid-divinyltetramethyldisiloxane, and the Pt atom content in the platinum catalyst is 300-100000 ppm.

[0025] Preferably, S5, two layers of antifouling coating are applied on the surface of PU / ultra-thin woven fabric composite packaging leather by gravure printing, the first layer of antifouling coating comprises the following components in parts by weight: 100 parts of silicone modified polyurethane resin, 5-30 parts of high silicon modified waterborne polyurethane resin, 0.1-10 parts of acid catalyst, 0.1-5 parts of isocyanate crosslinking agent; the viscosity of the antifouling coating is 600-800cps / 23°C; the second layer of antifouling coating comprises the following components in parts by weight: 100 parts of epoxy modified silicone resin, 0.1-2 parts of platinum catalyst, 0.1-5 parts of accelerator; the viscosity of the antifouling coating is 600-800cps / 23°C.

[0026] Preferably, the first antifouling coating comprises the following components by weight: 100 parts of organosilicon-modified polyurethane resin (solid content 30%), 15 parts of high-silicon-modified waterborne polyurethane resin, 2 parts of acid catalyst, 2 parts of isocyanate crosslinking agent, the viscosity is adjusted to 700cps / 23°C, and the coating amount is 25g / m 2 The second antifouling coating includes the following components by weight: 100 parts of epoxy modified silicone resin, 0.5 parts of platinum catalyst, 2 parts of accelerator, 20 parts of propylene glycol, the viscosity is adjusted to 700cps / 23℃, and the coating amount is 25g / m 2 .

[0027] The additives described in the present invention include leveling agents, thickeners, defoamers, crosslinking agents, platinum catalysts, silicone wear-resistant feel agents, etc., which are all conventionally selected and can be selected by those skilled in the art according to specific circumstances. For example, the leveling agent is preferably a silicone-modified polyether water-based leveling agent such as BYK-346 and BYK-348, and the defoamer is preferably a silicone-modified bubble suppressing additive such as BYK-024 and BYK-054.

[0028] An ultra-thin electronic packaging leather prepared according to the method of the present invention comprises, from bottom to top, a base fabric layer, an adhesive layer, an intermediate layer, a surface layer and an anti-fouling layer.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. The ultra-thin electronic packaging leather of the present invention uses ultra-thin woven fabric as the base material, and the thickness of the finished product can be controlled within the range of 0.15-0.25 mm, which can meet the requirements of electronic products, especially mobile phone back covers, for lightness and thinness;

[0031] 2. The present invention adopts water-based polyurethane resin and solvent-free system, completely avoiding the use of harmful organic solvents such as DMF, and the preparation process is more environmentally friendly;

[0032] 3. The present invention forms an antifouling layer on the product surface through the gravure printing process, which improves the antifouling performance and wear resistance of the product, and makes the product have excellent cleanliness and durability;

[0033] 4. The ultra-thin electronic packaging leather prepared by the present invention has excellent physical properties, including high tensile load, moderate elongation at break, good tear strength and peel strength, and outstanding wear resistance, stain resistance and aging resistance. DETAILED DESCRIPTION

[0034] The technical solution of the present invention is further described in detail below through specific embodiments. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the protection scope of the present invention.

[0035] In the present invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used can be purchased from the market or are commonly used in the art. The methods in the following embodiments are all conventional methods in the art unless otherwise specified.

[0036] Unless otherwise specified, the reagents used in the following examples can be purchased from conventional biochemical reagent stores.

[0037] Waterborne polyurethane surface resin, anionic aliphatic waterborne hydroxyl polyurethane dispersion, Wanhua Chemical 6512;

[0038] Waterborne polyurethane intermediate layer resin, anionic aliphatic waterborne polyurethane dispersion, Wanhua Chemical 6110;

[0039] Adhesive layer resin, polyether polyurethane, model XCNS-3015A, Asahikawa Chemical (Suzhou) Co., Ltd.;

[0040] Isocyanate-terminated polyurethane prepolymer, solid content 100%, model 3015B, Asahikawa Chemical (Suzhou) Co., Ltd.;

[0041] Epoxy modified silicone resin, model SH-023, Hubei Longsheng Sihai New Materials Co., Ltd.;

[0042] Defoamer, BYK-024; Crosslinker, Wanhua Chemical 161; Thickener, Wanhua Chemical U605A; Leveling agent, BYK-346; Silicone wear-resistant feel agent, Siluoke 51; Filler, calcium carbonate, Merrill;

[0043] Silicone modified polyurethane resin, Silok Dolphin 1090R2 silicone PUD resin;

[0044] High silicon modified waterborne polyurethane resin, Silok Dolphin 1089R3 resin;

[0045] Acid catalyst, bismuth neodecanoate, Deyin Chemical DY-20;

[0046] Platinum catalyst, chloroplatinic acid-1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane;

[0047] Accelerator, water-based blocked isocyanate, Siloke WinWin BL-6640.

[0048] The core of the present invention is to protect an ultra-thin electronic packaging leather, which includes a base fabric layer, an adhesive layer, an intermediate layer, a surface layer and an anti-fouling layer from bottom to top. The preparation method of the ultra-thin electronic packaging leather specifically includes the following steps:

[0049] S1. Base fabric preparation:

[0050] The ultra-thin woven fabric with polyester and spandex blended and encrypted plain weave four-way stretch is used, in which the polyester content accounts for 75%-90% and the spandex content accounts for 10%-25%; the primary color yarn is subjected to pre-treatment processes such as dyeing, rinsing, and drying, and then woven on a loom, and subjected to post-finishing processes such as shaping and ironing to obtain the base fabric layer;

[0051] S2, coating the surface layer slurry on the surface of the release paper, heating and drying, to obtain the packaging leather surface layer; coating the middle layer slurry on the surface layer, heating and drying, to obtain the packaging leather middle layer;

[0052] S3, the base fabric layer is compounded with the middle layer through the adhesive layer:

[0053] Apply the adhesive layer slurry to the middle layer of the packaging leather and semi-dry laminate the bottom fabric layer;

[0054] S4, putting the laminated base fabric layer with release paper into a 135°C oven for aging for 10-20 minutes, taking it out and peeling it off to obtain a PU / ultra-thin woven fabric composite packaging leather;

[0055] S5. Apply antifouling coating on the surface of PU / ultra-thin woven fabric composite packaging leather by gravure printing, with a coating amount of 20-30g / m 2 , and dried and matured at a temperature of 170℃±10℃ to form an anti-fouling layer to obtain an ultra-thin electronic packaging leather product.

[0056] The slurry formula of each layer is as follows (parts by weight):

[0057]

[0058]

[0059] The antifouling coating formula is as follows (parts by weight):

[0060]

[0061] The ultra-thin electronic packaging leather prepared by the present invention was subjected to various tests, and the test data are as follows:

[0062]

[0063]

[0064] Example 1

[0065] A method for preparing an ultra-thin electronic packaging leather, comprising the following specific steps:

[0066] S1. Base fabric preparation:

[0067] The ultra-thin woven fabric is made of polyester and spandex blended plain weave four-way stretch, of which the polyester content accounts for 75% and the spandex content accounts for 25%. The original color yarn is subjected to pre-treatment processes such as dyeing, rinsing, and drying, and then woven on a loom, and subjected to post-finishing processes such as shaping and ironing to obtain the base fabric layer.

[0068] S2, coating the surface layer slurry on the surface of the release paper, heating and drying, to obtain the packaging leather surface layer; coating the middle layer slurry on the surface layer, heating and drying, to obtain the packaging leather middle layer;

[0069] S3, the base fabric layer is compounded with the middle layer through the adhesive layer:

[0070] Apply the adhesive layer slurry to the middle layer of the packaging leather and semi-dry laminate the bottom fabric layer;

[0071] S4, putting the laminated base fabric layer with release paper into a 135°C oven for aging for 10-20 minutes, taking it out and peeling it off to obtain a PU / ultra-thin woven fabric composite packaging leather;

[0072] S5. Apply antifouling coating on the surface of PU / ultra-thin woven fabric composite packaging leather by gravure printing, with a coating amount of 20-30g / m 2 , and dried and matured at a temperature of 170℃±10℃ to form an anti-fouling layer to obtain an ultra-thin electronic packaging leather product.

[0073] The base fabric is made of polyester + spandex (30D+20D*30D+20D), with 85% polyester and 15% spandex. The base fabric weighs 45gsm and has a thickness of 0.09mm.

[0074] Surface slurry formula: 100 parts of anionic aliphatic water-based hydroxyl polyurethane dispersion (solid content 40%), 0.1 parts of defoamer, 1 part of cross-linking agent, 1 part of thickener, 0.5 parts of leveling agent, 1 part of silicone wear-resistant feel agent, 5 parts of black water-based color paste, adjust the viscosity to 5000cps / 25℃, and apply 200g / m 2 .

[0075] Middle layer slurry formula: 100 parts of anionic aliphatic waterborne polyurethane dispersion (solid content 45%), 0.1 parts of defoamer, 0.5 parts of leveling agent, 1 part of thickener, 15 parts of black waterborne color paste, adjust the viscosity to 5000cps / 25℃, and apply 200g / m 2 .

[0076] Adhesive layer slurry formula: 100 parts of polyether polyurethane, 0.5 parts of dibutyltin dilaurate, 0.5 parts of bismuth isooctanoate, 10 parts of matting powder, 120 parts of isocyanate-terminated polyurethane prepolymer, adjust the viscosity to 5000cps / 25℃, and the coating amount is 200g / m 2 .

[0077] Antifouling coating formula (gravure printing): 100 parts of silicone modified polyurethane resin (solid content 30%), 15 parts of high silicon modified waterborne polyurethane resin, 2 parts of acid catalyst, 2 parts of isocyanate crosslinking agent, adjust the viscosity to 700cps / 23℃, coating amount 25g / m 2 .

[0078] Example 2

[0079] A method for preparing an ultra-thin electronic packaging leather, the specific steps are the same as those in Example 1, except that:

[0080] The base fabric is made of polyester + spandex (20D+15D*20D+15D), with 80% polyester and 20% spandex. The base fabric weighs 50gsm and has a thickness of 0.085mm.

[0081] Surface slurry formula: 100 parts of anionic aliphatic water-based hydroxyl polyurethane dispersion (solid content 40%), 0.15 parts of defoamer, 2 parts of environmentally friendly water-based crosslinking agent, 2 parts of thickener, 1 part of leveling agent, 2 parts of silicone wear-resistant feel agent, 10 parts of white water-based color paste, adjust the viscosity to 6000cps / 25℃, and the coating amount is 250g / m 2 .

[0082] Middle layer slurry formula: 100 parts of anionic aliphatic waterborne polyurethane dispersion (solid content 45%), 0.15 parts of defoamer, 1 part of leveling agent, 2 parts of thickener, 20 parts of white waterborne color paste, adjust the viscosity to 6000cps / 25℃, coating amount 250g / m 2 .

[0083] Adhesive layer slurry formula: 100 parts of polyether polyurethane, 0.8 parts of dibutyltin dilaurate, 0.8 parts of bismuth isooctanoate, 15 parts of aluminum hydroxide, 130 parts of isocyanate-terminated polyurethane prepolymer, adjust the viscosity to 6000cps / 25℃, and the coating amount is 250g / m 2 .

[0084] Example 3

[0085] A method for preparing an ultra-thin electronic packaging leather, the specific steps are the same as those in Example 1, except that:

[0086] The base fabric is made of polyester + spandex (30D+20D*30D+20D), with 90% polyester and 10% spandex. The base fabric weighs 55gsm and has a thickness of 0.095mm.

[0087] Surface slurry formula: 100 parts of anionic aliphatic water-based hydroxyl polyurethane dispersion (solid content 40%), 0.2 parts of defoamer, 3 parts of environmentally friendly water-based crosslinking agent, 3 parts of thickener, 2 parts of leveling agent, 3 parts of silicone wear-resistant feel agent, 15 parts of blue water-based color paste, adjust the viscosity to 8000cps / 25℃, and the coating amount is 300g / m 2 .

[0088] Middle layer slurry formula: 100 parts of anionic aliphatic waterborne polyurethane dispersion (solid content 45%), 0.2 parts of defoamer, 2 parts of leveling agent, 3 parts of thickener, 30 parts of blue waterborne color paste, adjust the viscosity to 8000cps / 25℃, coating amount 300g / m 2 .

[0089] Adhesive layer slurry formula: 100 parts of polyether polyurethane, 1 part of dibutyltin dilaurate, 1 part of bismuth isooctanoate, 20 parts of glass microspheres, 140 parts of isocyanate-terminated polyurethane prepolymer, adjust the viscosity to 8000cps / 25℃, and the coating amount is 300g / m 2 .

[0090] Example 4

[0091] The solution of Example 3 is adopted, but the antifouling layer is coated with two layers, and the specific differences are:

[0092] S5, the first antifouling coating is applied by gravure printing on the surface of PU / ultra-thin woven fabric composite packaging leather, with a coating amount of 25g / m 2 , dry and mature at 170℃±10℃ to form the first antifouling layer, and then continue to gravure print the second antifouling layer on the surface of the first antifouling layer, with a coating amount of 20-30g / m 2, and dried and matured at a temperature of 170℃±10℃ to form a second anti-fouling layer to obtain an ultra-thin electronic packaging leather product.

[0093] The first antifouling coating formula (gravure printing) is: 100 parts of organosilicon-modified polyurethane resin (solid content 30%), 15 parts of high-silicon-modified waterborne polyurethane resin, 2 parts of acid catalyst, 2 parts of isocyanate crosslinking agent, viscosity adjusted to 700cps / 23℃, coating amount 25g / m 2 .

[0094] The second antifouling coating formula (gravure printing) is: 100 parts of epoxy modified silicone resin, 0.5 parts of platinum catalyst, 2 parts of accelerator, 20 parts of propylene glycol, viscosity adjusted to 700cps / 23℃, coating amount 25g / m 2 .

[0095] Comparative Example 1

[0096] The solution of Example 1 is adopted, but no antifouling layer is added.

[0097] Comparative Example 2

[0098] The solution of Example 2 is adopted, but the surface layer and the middle layer use traditional solvent-based polyurethane resin instead of the water-based polyurethane resin selected in the present invention.

[0099] Comparative Example 3

[0100] The solution of Example 3 is adopted, but the base fabric is a woven fabric of ordinary thickness (0.3mm).

[0101] Performance Testing

[0102] The performance comparison of the embodiment and the comparative example is shown in Table 1. The peel strength is measured before the antifouling coating is applied, and the surface of the packaging leather product is smooth and cannot be adhered.

[0103] Table 1 Performance comparison data of each embodiment and comparative example

[0104]

[0105]

[0106] From the above experimental results, we can see that:

[0107] 1. All three embodiments of the present invention obtain ideal ultra-thin electronic packaging leather, with the product thickness controlled below 0.25 mm while maintaining good physical properties. In contrast, Comparative Example 3 uses a base fabric of ordinary thickness, and the final product thickness reaches 0.45 mm, which is not suitable for use as ultra-thin electronic packaging leather.

[0108] 2. Examples 1-3 all have excellent anti-fouling performance (level 5), while the anti-fouling performance of Comparative Example 1 is significantly reduced (level 2) due to the lack of an anti-fouling layer. This shows that the anti-fouling layer design in the present invention plays an important role in improving the anti-fouling performance of the product.

[0109] 3. The VOC emissions of Examples 1-3 are all lower than 50 mg / m 2 However, in Comparative Example 2, due to the use of traditional solvent-based polyurethane resin, the VOC emission exceeds 500 mg / m 2 , which does not meet environmental protection requirements. This shows that the waterborne polyurethane system used in the present invention has significant environmental advantages.

[0110] 4. In terms of wear resistance and aging resistance, the three embodiments of the present invention all achieve good levels, among which embodiment 3 has the best performance, which is related to the higher amount of cross-linking agent in its formula.

[0111] 5. Comprehensively considering various performance indicators, Examples 3 and 4 performed the best. Since Example 4 has two antifouling layers, it has better antifouling performance. This is mainly due to its optimized formula design, including higher coating amounts of the surface layer and the middle layer, and a more complete antifouling layer formula.

[0112] The above experimental results fully prove that the preparation method of ultra-thin electronic packaging leather provided by the present invention not only realizes the ultra-thin characteristics of the product, but also has outstanding environmental protection and stain resistance while maintaining excellent physical properties, which fully meets the requirements of modern electronic products for packaging materials.

[0113] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0114] The above is a detailed introduction to an ultra-thin electronic packaging leather and a preparation method thereof provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing ultra-thin electronic packaging leather, characterized in that The method comprises the following steps: S1. Base fabric preparation: The base fabric layer is an ultra-thin woven fabric with polyester and spandex blended and encrypted plain weave four-way stretch, of which the polyester content accounts for 75%-90% by weight and the spandex content accounts for 10%-25% by weight; S2, coating the surface layer slurry on the surface of the release paper, heating and drying, to obtain the packaging leather surface layer; coating the middle layer slurry on the surface layer, heating and drying, to obtain the packaging leather middle layer; S3, the base fabric layer is compounded with the middle layer through the adhesive layer: Apply the adhesive layer slurry to the middle layer of the packaging leather and semi-dry laminate the bottom fabric layer; S4, putting the laminated base fabric layer with release paper into a 135°C oven for aging for 10-20 minutes, taking it out and peeling it off to obtain a PU / ultra-thin woven fabric composite packaging leather; S5. Apply antifouling coating on the surface of PU / ultra-thin woven fabric composite packaging leather by gravure printing, with a coating amount of 20-30g / m 2 , and dried and matured at a temperature of 170℃±10℃ to form an anti-fouling layer to obtain an ultra-thin electronic packaging leather product.

2. The preparation method according to claim 1, characterized in that: The ultra-thin woven fabric is made of polyester and spandex (30D+20D*30D+20D) or (20D+15D*20D+15D), with a gram weight of 40-60gsm and a thickness of 0.08-0.1mm; the thickness of the finished ultra-thin electronic packaging leather is 0.15-0.25mm.

3. The preparation method according to claim 1, characterized in that: The surface slurry comprises the following components by weight: 100 parts of anionic aliphatic waterborne hydroxyl polyurethane dispersion, 0.01-0.2 parts of defoaming agent, 0.1-3 parts of crosslinking agent, 0.1-3 parts of thickener, 0.1-2 parts of leveling agent, 0.1-3 parts of silicone wear-resistant feel agent, 1-15 parts of color paste, wherein the solid content of the anionic aliphatic waterborne hydroxyl polyurethane dispersion is 35-45%, the viscosity of the surface slurry is 1000-10000cps / 25℃, and the coating amount is 100-300g / m 2 ; Preparation of surface slurry: Add silicone wear-resistant feel agent, leveling agent and water-based color paste to anionic aliphatic water-based hydroxyl polyurethane dispersion, add defoamer while stirring, add thickener to adjust the appropriate viscosity, stir and disperse evenly, add cross-linking agent before production, stir lightly, filter, and vacuum degas.

4. The preparation method according to claim 1, characterized in that: The intermediate layer slurry includes the following components by weight: 100 parts of anionic aliphatic waterborne polyurethane dispersion, 0.01-0.2 parts of defoamer, 0.1-2 parts of leveling agent, 0.1-3 parts of thickener, 10-30 parts of color paste, wherein the solid content of the anionic aliphatic waterborne polyurethane dispersion is 30-60%, the viscosity of the intermediate layer slurry is 1000-10000cps / 25℃, and the coating amount is 100-300g / m 2 ; Preparation of the middle layer slurry: Add leveling agent and water-based color paste to anionic aliphatic water-based polyurethane dispersion, add defoamer while stirring, disperse completely, add thickener to adjust the appropriate viscosity, filter, and vacuum degas.

5. The preparation method according to claim 1, characterized in that: The adhesive layer slurry includes the following components by weight: 100 parts of polyether polyurethane, 0.1-1 parts of dibutyltin dilaurate, 0.1-1 parts of bismuth isooctanoate, 100-140 parts of isocyanate-terminated polyurethane prepolymer, 5-30 parts of filler, with a viscosity of 2000-10000cps / 25°C and a coating amount of 100-300g / m 2 The filler is selected from one or a mixture of two or more of matting powder, aluminum hydroxide, aluminum oxide, magnesium hydroxide, zinc borate, aluminum silicate, magnesium carbonate, glass microbeads, white carbon black, silicone resin powder, silicon dioxide, calcium carbonate or magnesium oxide; Preparation of adhesive layer slurry: Take 100 parts of polyether polyurethane, add filler, dibutyltin dilaurate and bismuth isooctanoate, stir evenly to obtain solvent-free adhesive layer resin; mix polyether polyurethane with isocyanate-terminated polyurethane prepolymer, stir quickly to obtain adhesive layer slurry.

6. The preparation method according to claim 1, characterized in that: The antifouling coating comprises the following components by weight: 100 parts of organosilicon-modified polyurethane resin, 5-30 parts of high-silicon-modified waterborne polyurethane resin, 0.1-10 parts of acid catalyst, and 0.1-5 parts of isocyanate crosslinking agent; the viscosity of the antifouling coating is 600-800cps / 23°C.

7. The preparation method according to claim 1, characterized in that: In antifouling coatings, The platinum catalyst is selected from one or more of chloroplatinic acid-divinyltetramethyldisiloxane complex, chloroplatinic acid-1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane or chloroplatinic acid-divinyltetramethyldisiloxane, and the Pt atom content in the platinum catalyst is 300-100000 ppm.

8. The preparation method according to claim 1, characterized in that: S5, two layers of antifouling coating are printed on the surface of PU / ultra-thin woven fabric composite packaging leather by gravure printing. The first antifouling coating comprises the following components by weight: 100 parts of organosilicon-modified polyurethane resin, 5-30 parts of high-silicon-modified waterborne polyurethane resin, 0.1-10 parts of acid catalyst, and 0.1-5 parts of isocyanate crosslinking agent; The viscosity of the antifouling coating is 600-800cps / 23°C; The second antifouling coating comprises the following components by weight: 100 parts of epoxy modified silicone resin, 0.1-2 parts of platinum catalyst, and 0.1-5 parts of accelerator; The viscosity of the antifouling coating is 600-800cps / 23°C.

9. The preparation method according to claim 8, characterized in that: The first antifouling coating includes the following components by weight: 100 parts of organosilicon-modified polyurethane resin (solid content 30%), 15 parts of high-silicon-modified waterborne polyurethane resin, 2 parts of acid catalyst, 2 parts of isocyanate crosslinking agent, the viscosity is adjusted to 700cps / 23°C, and the coating amount is 25g / m 2 ; The second antifouling coating includes the following components by weight: 100 parts of epoxy modified silicone resin, 0.5 parts of platinum catalyst, 2 parts of accelerator, 20 parts of propylene glycol, the viscosity is adjusted to 700cps / 23℃, and the coating amount is 25g / m 2 .

10. An ultra-thin electronic packaging leather prepared according to the method of claim 1, the ultra-thin electronic packaging leather comprising, from bottom to top, a base fabric layer, an adhesive layer, an intermediate layer, a surface layer and an anti-fouling layer.

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