Foamed sponge organic silicon synthetic leather and preparation method thereof

Abstract

The invention discloses foamed sponge organic silicon synthetic leather which is of a multi-layer composite structure and sequentially comprises a cloth base layer, a first bonding layer, a sponge layer, a second bonding layer, a surface layer and a surface treatment layer. Each functional layer takes vinyl-terminated polysiloxane, hydrogen-containing polysiloxane, resin, a catalyst and an inhibitor as base materials, and differential performance is realized by adjusting the ratio of the base materials and / or adding specific functional aids. The invention further provides a preparation method of the synthetic leather, the preparation method comprises the steps of burdening, mixing, texture transfer and calendering fitting, surface treatment and post-treatment, and the process is simple, green and environment-friendly. By introducing the foaming sponge layer structure, the synthetic leather has soft hand feeling and high rebound resilience which are close to those of natural leather while keeping the excellent characteristics of an organic silicon material, is stain-resistant, flame-retardant and wear-resistant, and is suitable for the fields of high-end soft veneers such as household interiors, automobile seats and the like.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of polymer composites, and particularly relates to a foamed sponge body organic silicon synthetic leather and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the automobile, home and other industries, the market has increasingly high requirements for the performance of synthetic leather. At present, the mainstream synthetic leather materials are still mainly polyvinyl chloride (PVC) and polyurethane (PU).

[0003] (1) Although the polyvinyl chloride synthetic leather has low cost and simple processing, it has defects such as poor air permeability, hardening at low temperature, decreased flexibility, easy cracking and insufficient slip resistance.

[0004] (2) Although the polyurethane synthetic leather has soft hand feeling, good air permeability and environmental protection performance, it is widely used in the manufacture of leather clothes, but it has poor water resistance and light resistance and is easy to age. In addition, a large amount of organic solvent is used in the production process of the polyvinyl chloride and polyurethane synthetic leather, which causes serious pollution to the environment.

[0005] (3) The organic silicon synthetic leather is a new type of polymer material with a silicon-oxygen bond (Si-O) as the main chain skeleton, and has excellent high and low temperature resistance, hydrophobicity, moisture resistance, weather resistance, non-toxicity, environmental friendliness and other characteristics. The colloidal stability of the organic silicon synthetic leather is good, the color of the product is bright, the color fastness is high, the hand feeling is soft and smooth, and the product also has excellent water resistance and stain resistance. However, the existing organic silicon synthetic leather products still have obvious differences in touch and resilience compared with natural leather.

[0006] In view of the above problems, it is urgent to develop a new type of foamed sponge body organic silicon synthetic leather. Therefore, the present application introduces a foamed sponge layer structure, which not only retains the advantages of organic silicon, but also significantly improves the resilience and softness of the product, so that the hand feeling is closer to natural leather, and the use comfort and comprehensive performance are considered. SUMMARY

[0007] In view of the deficiencies of the prior art, the first object of the present application is to provide a foamed sponge body organic silicon synthetic leather, which has excellent flame retardance, weather resistance and other properties, and has resilience and soft touch.

[0008] A foamed sponge body organic silicon synthetic leather has a multilayer composite structure, and sequentially comprises a cloth base layer, a first adhesive layer, a sponge layer, a second adhesive layer, a surface layer and a surface treatment layer. The first adhesive layer, the sponge layer, the second adhesive layer, the surface layer and the surface treatment layer all use vinyl-terminated polysiloxane, hydrogen-containing polysiloxane, resin, catalyst, inhibitor and filler as the base material, and the differentiated properties are realized by changing the proportions between the base materials and / or adding specific functional additives.

[0009] As a preferred technical scheme, the first adhesive layer and the second adhesive layer are of the same formula and include the following components in parts by mass: vinyl-terminated polysiloxane 100 parts, filler 10-40 parts, resin 1-10 parts, catalyst 0.1-2 parts, inhibitor 0.4-4 parts, hydrogen-containing polysiloxane 1-10 parts, color paste 0.5-2 parts, and the coating thickness of the first adhesive layer and the second adhesive layer is 0.05-0.2 mm.

[0010] As a preferred technical scheme, the sponge layer includes the following components in parts by mass: vinyl-terminated polysiloxane 100 parts, hydrogen-containing polysiloxane 1-10 parts, catalyst 0.1-2 parts, resin 10-50 parts, inhibitor 0.5-5 parts, filler 10-90 parts, color paste 0.5-2 parts, coupling agent 0.1-10 parts, hydroxyl-terminated polydimethylsiloxane 1-80 parts, foaming agent 1-50 parts, foaming aid 1-20 parts, and the thickness of the foamed sponge layer is 1.5-3 mm.

[0011] As a preferred technical scheme, the surface layer includes the following components in parts by mass: vinyl-terminated polysiloxane 100 parts, catalyst 0.1-2 parts, inhibitor 0.4-4 parts, filler 20-40 parts, hydrogen-containing polysiloxane 1-10 parts, resin 50-100 parts, color paste 0.5-2 parts, and the coating thickness of the surface layer is 0.1-0.2 mm.

[0012] As a preferred technical scheme, the surface treatment layer includes the following components in parts by mass: vinyl-terminated polysiloxane 100 parts, filler 10-30 parts, catalyst 0.1-2 parts, inhibitor 0.4-4 parts, resin 20-40 parts, hydrogen-containing polysiloxane 1-30 parts, color paste 0.5-2 parts, and the coating thickness of the surface treatment layer is 0.05-0.2 mm.

[0013] As a preferred technical scheme, the cloth base layer has a thickness of 0.8-1.5 mm.

[0014] As a preferred technical scheme, the vinyl-terminated polysiloxane has a viscosity of 1000-100000 mPa·s at 25℃ and a vinyl mass fraction of 0.1%-2%, and the resin is a branched organic polysiloxane containing at least one Q unit.

[0015] As a preferred technical scheme, the catalyst is platinum-vinylsiloxane complex, alcohol-modified chloroplatinic acid, or platinum-alkynyl complex.

[0016] As a preferred technical scheme, the inhibitor is an alkyne alcohol compound, a polyvinyl polysiloxane, an amide compound, or a maleate compound.

[0017] As a preferred technical solution, the filler comprises one or more of white carbon black, quartz powder, aluminum hydroxide, magnesium hydroxide, wollastonite, calcium carbonate, matt powder or nylon powder.

[0018] As a preferred technical solution, the hydrogen-containing polysiloxane is an organic polysiloxane containing at least one Si-H bond, including end-hydrogen, side-hydrogen or end-side-hydrogen structure, and the hydrogen mass fraction is 0.5% to 1.6%.

[0019] As a preferred technical solution, the coupling agent used in the sponge layer is one or more of KH-560, KH-570, A-171 and A-172; the hydroxyl mass fraction of the hydroxyl-terminated polydimethylsiloxane is 5% to 20%; the foaming agent is one or more of sodium bicarbonate, 1,3-benzenedisulfonohydrazide and p-toluenesulfonylhydrazide; and the foaming aid is one or more of water, methanol, ethanol, ethylene glycol, glycerol, benzyl alcohol or lauryl alcohol.

[0020] In view of the deficiencies of the prior art, a second object of the present application is to provide a preparation method of foamed sponge organic silicone synthetic leather, which is simple in process and suitable for large-scale industrial production and green in production process.

[0021] A preparation method of foamed sponge organic silicone synthetic leather comprises the following steps:

[0022] (1) batching: the required components of the first adhesive layer, the first adhesive layer, the sponge layer, the surface layer and the surface treatment layer are weighed according to the raw material ratio and mixed uniformly respectively;

[0023] (2) mixing: the mixed adhesive layer, sponge layer, surface layer and surface treatment layer raw materials are subjected to cold mixing and hot mixing treatment respectively, wherein the cold mixing temperature is 20-35℃, and the time is 2-5 hours; the hot mixing temperature is 100-120℃, and the time is 0.5-1 hour;

[0024] (3) texture transfer and calendering: the surface layer raw material is coated on the release paper printed with patterns in sequence, and is cured at 110-130℃ for 3-5 minutes to make the surface layer dimensionally stable and completely copy the patterns on the release paper; then the adhesive layer raw material is coated, and is cured at 90-120℃ for 2-3 minutes; then the sponge layer raw material is coated, and the release film is attached, and is subjected to 100-120℃ hot vulcanization treatment for 3-8 minutes; after cooling, the release film is peeled off, the adhesive layer raw material is coated again, and is cured at 90-120℃ for 3-8 minutes; finally, the cloth base layer is compounded on it by wet compounding process to obtain a semi-finished product;

[0025] (4) surface treatment: the surface treatment layer raw material is coated on the pattern surface of the surface layer, and is treated at 130-150℃ for 3-5 minutes.

[0026] (5) Post-processing: the semi-finished product after surface treatment is cooled and wound, and the foamed sponge organic silicone synthetic leather product is obtained.

[0027] As a preferred technical solution, the pattern of the surface layer is transferred by one-time hot pressing of the pattern on the release paper.

[0028] Compared with the prior art, the present application has the following advantages:

[0029] 1. The present application introduces a foamed sponge layer and a multi-layer composite structure design, which retains the inherent excellent properties of silicone materials, and at the same time makes the synthetic leather have high resilience and soft touch close to natural leather, and has excellent stain resistance, flame resistance and wear resistance. Based on the formation of a dense crosslinked network of Q units in organopolysiloxane resin, the tear resistance of the synthetic leather is effectively improved; at the same time, the adhesive layer has strong adhesion, which ensures the firm combination between the substrate and the functional layer and between the coating layers. The present application reasonably matches the components, and the foamed sponge layer has excellent resilience and flame resistance, so that the overall material of the synthetic leather has a full and high elastic touch, meeting the comprehensive needs of high-end soft synthetic leather for elasticity and deformation recovery. The synthetic leather of the present application can be widely used in the fields of soft decoration such as automotive interior, high-end home, yacht bulkhead, etc.

[0030] 2. The preparation method of the foamed sponge organic silicone synthetic leather is simple and efficient, does not use and produce formaldehyde and other harmful substances during production, is green and environmentally friendly, is suitable for large-scale industrial production, and has significant practicality and popularization value. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a micrograph of the cross section of the sponge layer of the foamed sponge organic silicone synthetic leather obtained in Example 1.

[0032] Figure 2 is a comparison chart of the UL94 vertical burning test of Example 1 before (left), during (middle) and after (right).

[0033] Figure 3 is a comparison chart of the Martin Dale wear resistance test of Example 1 before (left) and after (right). DETAILED DESCRIPTION

[0034] The features of the present application and other related features are further described in detail below through examples, so as to facilitate the understanding of the skilled in the art.

[0035] Example 1

[0036] The embodiment 1 of the present application provides a foamed sponge silicone synthetic leather, which comprises, in sequence, a cloth base layer (thickness 1.0 mm), a first adhesive layer (coating thickness 0.1 mm), a sponge layer (foaming thickness 1.6 mm), a second adhesive layer (coating thickness 0.1 mm), a surface layer (coating thickness 0.15 mm), and a surface treatment layer (coating thickness 0.1 mm).

[0037] The first / second adhesive layer comprises, by mass parts, 100 parts of vinyl-terminated polysiloxane, 5 parts of resin, 1 part of platinum-vinylsiloxane complex, 2 parts of acetylene cyclohexanol, 5 parts of hydrogen-containing polysiloxane, 30 parts of fumed white carbon black, and 0.8 parts of color paste.

[0038] The sponge layer comprises, by mass parts, 100 parts of vinyl-terminated polysiloxane, 20 parts of fumed white carbon black, 50 parts of calcium carbonate, 1 part of platinum-gold catalyst, 30 parts of resin, 2.5 parts of acetylene cyclohexanol, 1 part of color paste, 5 parts of hydrogen-containing polysiloxane, 5 parts of KH-560, 70 parts of hydroxyl-terminated polydimethylsiloxane, 40 parts of sodium bicarbonate, and 3 parts of water.

[0039] The surface layer comprises, by mass parts, 100 parts of vinyl-terminated polysiloxane, 20 parts of white carbon black, 20 parts of nylon powder, 0.5 parts of platinum-gold catalyst, 3 parts of acetylene cyclohexanol, 3 parts of hydrogen-containing polysiloxane, 0.8 parts of color paste, and 60 parts of resin.

[0040] The surface treatment layer comprises, by mass parts, 100 parts of vinyl-terminated polysiloxane, 20 parts of fumed white carbon black, 20 parts of matting powder, 1 part of platinum-gold catalyst, 2 parts of acetylene cyclohexanol, 15 parts of hydrogen-containing polysiloxane, 0.5 parts of color paste, and 25 parts of resin.

[0041] The foamed sponge silicone synthetic leather of the embodiment 1 comprises the following steps:

[0042] (1) Dosing: the components required for the adhesive layer, the sponge layer, the surface layer, and the surface treatment layer are respectively weighed according to the raw material ratio, and are respectively mixed uniformly.

[0043] (2) Mixing: the above mixed adhesive layer, sponge layer, surface layer, and surface treatment layer raw materials are respectively subjected to cold mixing and hot mixing treatment, wherein the cold mixing temperature is 30°C, and the time is 4 hours; the hot mixing temperature is 100°C, and the time is 1 hour.

[0044] (3) Texture transfer and calendering: coat the top layer raw material on the patterned release paper, cure at 110°C for 5 minutes to make the top layer set and completely copy the pattern on the release paper. Then coat the adhesive layer raw material, cure at 120°C for 2 minutes. Then coat the sponge layer raw material, cover the release film, and after heat vulcanization at 120°C for 5 minutes, cool down. After peeling off the release film, coat the adhesive layer raw material again, and cure at 120°C for 5 minutes. Finally, the base layer is compounded on it by wet lamination process to obtain the semi-finished product.

[0045] (4) Surface treatment: coat the surface treatment layer raw material on the patterned surface of the top layer, and treat at 150°C for 3 minutes.

[0046] (5) Post-treatment: cool down the semi-finished product after surface treatment, and roll up to obtain the foamed sponge organic silicone synthetic leather product of Example 1.

[0047] Example 2

[0048] Example 2 of the present application provides a foamed sponge organic silicone synthetic leather, which comprises in sequence: a base layer (thickness 1.0 mm), a first adhesive layer (coating thickness 0.1 mm), a sponge layer (foamed thickness 1.7 mm), a second adhesive layer (coating thickness 0.1 mm), a top layer (coating thickness 0.15 mm), and a surface treatment layer (coating thickness 0.1 mm).

[0049] The components of the first / second adhesive layer are the same as in Example 1.

[0050] The sponge layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, calcium carbonate 30 parts, platinum-gold catalyst 1.5 parts, resin 20 parts, acetylene cyclohexanol 1 part, color paste 0.8 part, hydrogen-containing polysiloxane 8 parts, KH-570 3 parts, hydroxyl-terminated polydimethylsiloxane 40 parts, 1,3-benzenedisulfonylhydrazide 40 parts, glycerol 3 parts.

[0051] The top layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, white carbon black 25 parts, platinum-gold catalyst 0.5 parts, acetylene cyclohexanol 3 parts, hydrogen-containing polysiloxane 3 parts, color paste 0.8 part, resin 60 parts.

[0052] The surface treatment layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, quartz powder 35 parts, platinum-gold catalyst 1.5 parts, polyvinyl polysiloxane 1 part, hydrogen-containing polysiloxane 7 parts, color paste 0.8 part, resin 40 parts.

[0053] The preparation steps of the foamed sponge organic silicone synthetic leather of Example 2 include:

[0054] (1) Dosing: weigh the required components of the adhesive layer, the sponge layer, the top layer, and the surface treatment layer, respectively, and mix them uniformly.

[0055] (2) Mixing: the mixed raw materials of the adhesive layer, the sponge layer, the surface layer and the surface treatment layer are respectively subjected to cold mixing and hot mixing treatment, wherein the cold mixing temperature is 30°C, and the time is 5 hours; the hot mixing temperature is 110°C, and the time is 0.5 hours.

[0056] (3) Texture transfer and calendering: the surface layer raw material is coated on the patterned release paper, and is cured at 120°C for 3 minutes to make the surface layer fixed and completely copy the pattern on the release paper. The adhesive layer is coated again, and is cured at 90°C for 5 minutes. Then the sponge layer raw material is coated, and the release film is attached. After being treated at 120°C for 5 minutes, it is cooled. After the release film is peeled off, the adhesive layer is coated again, and is cured at 110°C for 5 minutes. Finally, the cloth base layer is combined on it by wet bonding process to obtain the semi-finished product.

[0057] (4) Surface treatment: the surface treatment layer raw material is coated on the patterned surface of the surface layer, and is treated at 140°C for 5 minutes.

[0058] (5) Post-treatment: the semi-finished product after surface treatment is cooled and wound to obtain the foamed sponge organic silicone synthetic leather product of Example 2.

[0059] Example 3

[0060] Example 3 of the present application provides a foamed sponge organic silicone synthetic leather, which comprises in sequence: a cloth base layer (thickness 1.0 mm), a first adhesive layer (coating thickness 0.1 mm), a sponge layer (foaming thickness 1.8 mm), a second adhesive layer (coating thickness 0.1 mm), a surface layer (coating thickness 0.15 mm) and a surface treatment layer (coating thickness 0.1 mm).

[0061] The first / second adhesive layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, resin 8 parts, platinum gold catalyst 1 part, acetylene cyclohexanol 1 part, hydrogen-containing polysiloxane 8 parts, fumed white carbon black 40 parts, color paste 0.8 parts.

[0062] The sponge layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, wollastonite 70 parts, platinum gold catalyst 0.5 parts, resin 40 parts, dimethyl maleate 4 parts, color paste 0.8 parts, hydrogen-containing polysiloxane 3 parts, A-171 8 parts, hydroxyl-terminated polydimethylsiloxane 50 parts, 1,3-benzenedisulfonylhydrazide 20 parts, methanol 2 parts.

[0063] The surface layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, white carbon black 40 parts, platinum gold catalyst 1.5 parts, dimethyl maleate 1 part, hydrogen-containing polysiloxane 8 parts, color paste 0.8 parts, resin 90 parts.

[0064] The surface treatment layer comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, matting powder 20 parts, platinum gold catalyst 0.8 parts, multi-vinyl polysiloxane 3 parts, hydrogen-containing polysiloxane 12 parts, color paste 0.8 parts, and resin 28 parts.

[0065] The preparation steps of the foamed sponge organic silicone synthetic leather of Example 3 include:

[0066] (1) Preparation of ingredients: the components required for the adhesive layer, the sponge layer, the surface layer, and the surface treatment layer are weighed respectively according to the mass fraction, and are mixed uniformly.

[0067] (2) Mixing: the mixed adhesive layer, the sponge layer, the surface layer, and the surface treatment layer are subjected to cold mixing and hot mixing, respectively, wherein the cold mixing temperature is 30°C, and the time is 5 hours; the hot mixing temperature is 110°C, and the time is 0.5 hours.

[0068] (3) Texture transfer and calendering: the surface layer raw material is coated on the release paper printed with patterns, and is cured at 120°C for 3 minutes to make the surface layer dimensionally stable and completely copy the patterns on the release paper. The adhesive layer is then coated, and is cured at 100°C for 5 minutes. Then, the sponge layer raw material is coated, and the release film is attached. After being subjected to 120°C vulcanization treatment for 5 minutes, the release film is cooled. After the release film is peeled off, the adhesive layer is coated again, and is cured at 120°C for 5 minutes. Finally, the fabric base layer is combined thereon by a wet bonding process to obtain a semi-finished product.

[0069] (4) Surface treatment: the surface treatment layer raw material is coated on the patterned surface of the surface layer, and is treated at 150°C for 3 minutes.

[0070] (5) Post-treatment: the semi-finished product after surface treatment is cooled and wound, and a foamed sponge organic silicone synthetic leather product of Example 3 is obtained.

[0071] Example 4

[0072] The foamed sponge organic silicone synthetic leather provided in Example 4 is basically the same as in Example 1 except that the formula of the sponge layer is different. The sponge layer of Example 4 comprises, by mass fraction: vinyl-terminated polysiloxane 100 parts, aluminum hydroxide 80 parts, platinum gold catalyst 0.5 parts, resin 30 parts, acetylene cyclohexanol 2.5 parts, color paste 0.8 parts, hydrogen-containing polysiloxane 3 parts, A-172 5 parts, hydroxyl-terminated polydimethylsiloxane 45 parts, 1,3-benzenedisulfonylhydrazide 30 parts, and water 4 parts.

[0073] Example 5

[0074] The foamed sponge silicone synthetic leather provided in Example 5 is substantially the same as that of Example 1 except that the formulation of the surface layer is different. The surface layer of Example 5 includes, by mass parts, vinyl-terminated polysiloxane 100 parts, quartz powder 20 parts, platinum-gold catalyst 0.8 parts, polyvinyl polysiloxane 3 parts, hydrogen-containing polysiloxane 12 parts, color paste 0.8 parts, and resin 30 parts.

[0075] Example 6

[0076] The foamed sponge silicone synthetic leather provided in Example 6 is substantially the same as that of Example 1 except that the formulation of the surface treatment layer is different. The surface treatment layer of Example 6 includes, by mass parts, vinyl-terminated polysiloxane 100 parts, quartz powder 20 parts, platinum-gold catalyst 0.8 parts, polyvinyl polysiloxane 3 parts, hydrogen-containing polysiloxane 12 parts, color paste 0.8 parts, and resin 30 parts.

[0077] The resin of Examples 1 to 6 and Comparative Examples 1 to 6 is a branched organopolysiloxane containing at least one Q unit.

[0078] Comparative Example 1

[0079] The silicone synthetic leather provided in Comparative Example 1 is substantially the same as that of Example 1 except that sodium bicarbonate and water are not added to the sponge layer.

[0080] Comparative Example 2

[0081] The silicone synthetic leather provided in Comparative Example 2 is substantially the same as that of Example 1 except that the coating and curing steps of the adhesive layer are omitted in the calendering step.

[0082] Comparative Example 3

[0083] The silicone synthetic leather provided in Comparative Example 3 is substantially the same as that of Example 1 except that the quartz powder in the adhesive layer is replaced with an equal amount of vinyl-terminated polysiloxane.

[0084] Comparative Example 4

[0085] The silicone synthetic leather provided in Comparative Example 4 is substantially the same as that of Example 1 except that the hydroxyl-terminated polydimethylsiloxane is not added to the sponge layer.

[0086] Comparative Example 5

[0087] The silicone synthetic leather provided in Comparative Example 5 is substantially the same as that of Example 1 except that the resin is not added to the surface layer.

[0088] Comparative Example 6

[0089] Comparative Example 6 provides a silicone synthetic leather without matting powder in the surface treatment layer, and other specific embodiments are substantially the same as Example 1.

[0090] Performance Test

[0091] 1. Hand feeling test: In a standard environment of temperature (23±2) °C and humidity (50±5) %, the palm is placed on the surface of the foamed sponge body silicone synthetic leather sample, and reciprocating friction is performed with uniform force. The sample is graded according to the touch feeling as follows: qualified, dry and smooth; general, dry and slightly rough; unqualified, cold and rough.

[0092] 2. Stain resistance test: three samples of 100x200mm are cut, avoiding defects such as flaws, spots, stains, etc. After drawing with morning round ball pen No. 6546 and Dali marker pen No. 6824, a cleaning agent (20% ethanol solution) and a soft cloth are used for wiping. According to the Q / JLY J7110614B-2015 standard, the residual stain is rated according to the degree of obviousness, with 5 being the best and 1 being the worst, which cannot be wiped off.

[0093] 3. Hardness test: using a Shore hardness tester, according to GB / T531.1-2008 standard for testing. The sample is a complete foamed sponge body silicone synthetic leather and is tested on the cloth base layer side. At least 5 times are measured at different positions, and the average value is taken.

[0094] 4. Foaming ratio test: according to GB / T6343-2009 standard by measuring the apparent density of the sample. Foaming ratio = raw material density / sample apparent density.

[0095] 5. Foaming pore size: using a digital electronic microscope to observe the cross section of the sample, the magnification is 200 times, and the average pore size is measured by using a ruler.

[0096] 6. Flame retardancy test: using UL 94 standard to evaluate the flame retardant performance of synthetic leather, at least 3 sample bars are tested for each example.

[0097] 7. Tensile strength: the synthetic leather is cut into I-shaped dumbbell, according to GB / T 528-2009 standard for testing the tensile strength of each example.

[0098] 8. Tear strength: the synthetic leather is cut into a standard right-angle sample, and the tear strength is tested according to GB / T 529-2008.

[0099] 9. Abrasion resistance test: using Martindale method, according to GB / T13775 standard, using SM-25 type wool cloth, under the load of (12±0.2) kPa, friction 30000 times after surface treatment layer, appearance rating: 5 level, clear lines, no obvious wear; 4 level, light gloss change, clear lines; 3 level: surface lines can be seen but has been ground / fade, intermediate coating wear; 2 level, serious wear, the intermediate coating is obviously damaged; 1 level, coating wear, completely exposed to the base layer.

[0100] 10. Abrasion resistance test: using Taber method, according to ASTM-D3884 standard, using H-22 type grinding wheel, applying 1Kg load, friction 200 times, according to the appearance rating: 5 level: coating no visible wear, no change in haze; 4 level: coating lines are basically complete, light haze change; 3 level: coating lines can be seen but have wear, lines can still be seen; 2 level: coating serious wear, lines are basically ground; 1 level: coating is worn, exposing the base layer.

[0101] Table 1 is the performance test results of synthetic leather of examples and comparative examples

[0102]

[0103]

[0104] Table 2 is the performance test results of synthetic leather of examples and comparative examples

[0105] Tensile strength / MPa Tear strength / N / mm Martindale / class Taber abrasion / class Example 1 0.65 2.72 5 5 Example 2 0.53 2.64 4 4 Example 3 0.51 2.26 4 4 Example 4 0.53 2.47 5 3 Example 5 0.63 2.78 4 4 Example 6 0.72 3.4 5 5 Comparative Example 1 0.43 2.56 3 3 Comparative Example 2 0.42 2.16 4 2 Comparative Example 3 0.36 1.89 1 2 Comparative Example 4 0.54 1.63 2 1 Comparative Example 5 0.66 1.32 1 1 Comparative Example 6 0.72 1.02 1 1

[0106] From Tables 1-2, it can be seen that, compared with Example 1, Comparative Example 1 has a significantly lower foaming ratio, smaller pore size, higher hardness, and very poor Martindale abrasion resistance, indicating that a proper foaming ratio is a key factor for giving the synthetic leather a soft touch, suitable hardness, and excellent abrasion resistance.

[0107] Comparative Example 2 has a general touch, low foaming ratio, high hardness, and poor abrasion resistance, indicating that the lack of an adhesive layer has an impact on the foaming ratio of the foamed sponge layer, and is crucial to the performance of the foamed sponge layer. The lack of an adhesive layer not only reduces the interlayer bonding force, but more importantly, it cannot form an effective gas barrier layer, resulting in gas escaping during foaming, causing the foaming ratio to decrease, the pore size to be small and unevenly distributed.

[0108] Comparative Example 3 has the lowest tensile strength and lower tear strength among the samples, and also has poor abrasion resistance, indicating that white carbon black as a key reinforcing filler can significantly enhance the mechanical strength and durability of the synthetic leather. At the same time, its foaming ratio is significantly reduced, indicating that white carbon black also plays a role as a nucleating agent during foaming, which helps to form uniform pores and ensure the foaming ratio.

[0109] Comparative Example 4 is close to Example 1 in hardness and strength, but has low foaming ratio and general hand feeling, indicating that the hydroxyl-terminated polydimethylsiloxane has an effect on forming a uniform and stable cell structure of the sponge layer, and also affects the crosslinking degree of the sponge layer, resulting in a decrease in tear strength of the synthetic leather.

[0110] The tear strength of Comparative Example 5 is significantly decreased, the martindale abrasion resistance is decreased, and the flame retardant grade is also decreased, indicating that the resin in the surface layer not only helps to improve the mechanical properties and abrasion resistance of the coating, but also forms a dense three-dimensional crosslinked network based on the Q unit-containing organopolysiloxane resin, which can effectively improve the tear strength of the coating.

[0111] Comparative Example 6 has unqualified hand feeling, and the tear strength and abrasion resistance are significantly decreased. This indicates that the matting powder in the surface treatment layer not only provides an aesthetic effect, but also effectively improves the compactness and mechanical strength of the coating, and is a key component for giving the product good hand feeling, abrasion resistance and scratch resistance.

[0112] From Examples 1-6, it can be seen that the high-performance foamed sponge organic synthetic leather with soft hand feeling, excellent mechanical properties, excellent abrasion resistance and good flame retardant properties is successfully prepared by the synergistic design and preparation of the multi-functional layers such as the adhesive layer, the foamed sponge layer, the surface layer and the surface treatment layer. Each comparative example is verified on the contrary, and the absence of any key component or process will have a significant adverse effect on the comprehensive performance of the final product.

[0113] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A foamed sponge-like silicone synthetic leather, characterized in that, The synthetic leather has a multi-layer composite structure, comprising, in sequence, a base layer, a first adhesive layer, a sponge layer, a second adhesive layer, a top layer, and a surface treatment layer; the first adhesive layer, the sponge layer, the second adhesive layer, the top layer, and the surface treatment layer all use vinyl-terminated polysiloxane, hydrogen-containing polysiloxane, resin, catalyst, inhibitor, and filler as matrix materials, and differentiated properties are achieved by adjusting the ratio of matrix materials and / or adding specific functional additives.

2. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The first adhesive layer and the second adhesive layer are formulated with the same composition, comprising the following components by weight: 100 parts vinyl-terminated polysiloxane, 10-40 parts filler, 1-10 parts resin, 0.1-2 parts catalyst, 0.4-4 parts inhibitor, 1-10 parts hydrogen-containing polysiloxane, and 0.5-2 parts colorant; the coating thickness of both the first adhesive layer and the second adhesive layer is 0.05-0.2 mm.

3. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The sponge layer comprises the following components by weight: 100 parts vinyl-terminated polysiloxane, 1-10 parts hydrogen-containing polysiloxane, 0.1-2 parts catalyst, 10-50 parts resin, 0.5-5 parts inhibitor, 10-90 parts filler, 0.5-2 parts color paste, 0.1-10 parts coupling agent, 1-80 parts hydroxyl-terminated polydimethylsiloxane, 1-50 parts foaming agent, and 1-20 parts foaming aid; the thickness of the foamed sponge layer is 1.5-3 mm.

4. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The surface layer comprises the following components by weight: 100 parts vinyl-terminated polysiloxane, 0.1-2 parts catalyst, 0.4-4 parts inhibitor, 20-40 parts filler, 1-10 parts hydrogen-containing polysiloxane, 50-100 parts resin, and 0.5-2 parts color paste; the coating thickness of the surface layer is 0.1-0.2 mm.

5. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The surface treatment layer comprises the following components by weight: 100 parts vinyl-terminated polysiloxane, 10-30 parts filler, 0.1-2 parts catalyst, 0.4-4 parts inhibitor, 20-40 parts resin, 1-30 parts hydrogen-containing polysiloxane, and 0.5-2 parts color paste; the coating thickness of the surface treatment layer is 0.05-0.2 mm.

6. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The vinyl-terminated polysiloxane has a viscosity of 1000–100000 mPa·s at 25°C and a vinyl mass fraction of 0.1%–2%; the resin is a branched organopolysiloxane containing at least one Q unit.

7. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The catalyst is a platinum-vinylsiloxane complex, an alcohol-modified chloroplatinic acid, or a platinum-alkynyl complex; the inhibitor is an alkynyl alcohol compound, a polyvinyl polysiloxane, an amide compound, or a maleate compound; the filler includes one or more of the following: silica, quartz powder, aluminum hydroxide, magnesium hydroxide, wollastonite, calcium carbonate, matting agent, or nylon powder.

8. The foamed sponge-like silicone synthetic leather according to claim 1, characterized in that, The hydrogen-containing polysiloxane is an organopolysiloxane containing at least one Si-H bond, including end-hydrogen-containing, side-hydrogen-containing, or end-side-hydrogen-containing structures, with a hydrogen mass fraction of 0.5% to 1.6%.

9. The foamed sponge-like silicone synthetic leather according to claim 3, characterized in that, The coupling agent used in the sponge layer is one or more of KH-560, KH-570, A-171, and A-172; the hydroxyl mass fraction of the hydroxyl-terminated polydimethylsiloxane is 5% to 20%; the foaming agent is one or more of sodium bicarbonate, 1,3-benzenedisulfonyl hydrazine, and p-toluenesulfonyl hydrazine; and the foaming aid is one or more of water, methanol, ethanol, ethylene glycol, glycerol, benzyl alcohol, or lauryl alcohol.

10. A method for preparing silicone synthetic leather with foamed sponge structure as described in claims 1-9, characterized in that, Includes the following steps: (1) Ingredients: Weigh out the required components for the first adhesive layer, the second adhesive layer, the sponge layer, the top layer and the surface treatment layer according to the mass ratio, and mix them evenly. (2) Mixing: The mixed adhesive layer, sponge layer, surface layer and surface treatment layer raw materials are subjected to cold refining and hot refining respectively, wherein the cold refining temperature is 20-35℃ and the time is 2-5 hours; the hot refining temperature is 100-120℃ and the time is 0.5-1 hour. (3) Texture transfer and calendering lamination: The surface material is coated sequentially on the patterned release paper and cured at 110-130℃ for 3-5 minutes to set the surface and completely replicate the pattern on the release paper; then the adhesive layer material is coated and cured at 90-120℃ for 2-3 minutes; then the sponge layer material is coated, and the release film is covered and subjected to heat vulcanization treatment at 100-120℃ for 3-8 minutes; after cooling, the release film is peeled off, and the adhesive layer material is coated again and cured at 90-120℃ for 3-8 minutes; finally, the fabric base layer is laminated on it through a wet lamination process to obtain a semi-finished product; (4) Surface treatment: Coat the surface treatment layer material on the patterned surface of the surface layer and treat it at 130-150℃ for 3-5 minutes. (5) Post-processing: Cool the surface-treated semi-finished product to obtain the foamed sponge silicone synthetic leather finished product.

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