A foamed sponge silicone synthetic leather and a preparation method thereof

Abstract

The application discloses a foamed sponge organic silicone synthetic leather, and belongs to the field of synthetic leather technology.The synthetic leather is 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; each functional layer is prepared by taking vinyl-terminated polysiloxane, hydrogen-containing polysiloxane, resin, catalyst and inhibitor as a base material, and by adjusting the proportion of the base material and / or adding specific functional additives to realize differentiated performance; and the application also provides a preparation method of the synthetic leather, which comprises the steps of compounding, mixing, texture transfer and calendering, surface treatment and post-treatment, and is simple in process and green in environment protection; and the application introduces a foamed sponge layer structure, so that the synthetic leather not only retains the excellent characteristics of the organic silicone material, but also has a soft hand feeling and high resilience close to natural leather, is resistant to dirt, flame-retardant and wear-resistant, and is suitable for high-end soft surface fields such as home interior and automobile seats.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite materials technology, and specifically relates to a foamed sponge-based silicone synthetic leather and its preparation method. Background Technology

[0002] With the rapid development of industries such as automobiles and home furnishings, the market demands increasingly higher performance from synthetic leather. Currently, the mainstream synthetic leather materials are still polyvinyl chloride (PVC) and polyurethane (PU).

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

[0004] (2) Although polyurethane synthetic leather is soft to the touch, breathable, and environmentally friendly, and is widely used in leather garment manufacturing, it has poor water resistance and light resistance and is prone to aging. In addition, the production process of polyvinyl chloride and polyurethane synthetic leather requires a large amount of organic solvents, which causes serious environmental pollution.

[0005] (3) Organosilicon synthetic leather is a novel polymer material with silicon-oxygen bonds (Si-O) as the main chain backbone. It has excellent high and low temperature resistance, water repellency and moisture resistance, weather aging resistance, non-toxicity, and environmental friendliness. Its colloidal stability is good, and the products have bright colors, high color fastness, and a smooth and silky feel. It also has excellent waterproof and stain-resistant properties. However, existing organosilicon synthetic leather products still have a significant gap with natural leather in terms of touch and resilience.

[0006] To address the aforementioned issues, there is an urgent need to develop a novel foamed sponge-based silicone synthetic leather. Therefore, this invention introduces a foamed sponge layer structure, which, while retaining the advantages of silicone, significantly improves the product's resilience and softness, making its feel closer to natural leather, thus balancing user comfort and overall performance. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the first objective of the present invention is to provide a foamed sponge silicone synthetic leather with excellent flame retardant and weather-resistant properties, as well as resilience and soft touch.

[0008] A foamed sponge silicone synthetic leather has a multi-layer composite structure, comprising 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 changing the ratio between matrix materials and / or adding specific functional additives.

[0009] As a preferred technical solution, the first adhesive layer and the second adhesive layer are of the same formulation, comprising the following components by weight: 100 parts of vinyl-terminated polysiloxane, 10-40 parts of filler, 1-10 parts of resin, 0.1-2 parts of catalyst, 0.4-4 parts of inhibitor, 1-10 parts of hydrogen-containing polysiloxane, and 0.5-2 parts of colorant. The coating thickness of both the first adhesive layer and the second adhesive layer is 0.05-0.2 mm.

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

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

[0012] As a preferred technical solution, 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.

[0013] As a preferred technical solution, the thickness of the fabric base layer is 0.8 to 1.5 mm.

[0014] As a preferred technical solution, 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.

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

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

[0017] As a preferred technical solution, the filler includes one or more of the following: silica, quartz powder, aluminum hydroxide, magnesium hydroxide, wollastonite, calcium carbonate, matting agent, or nylon powder.

[0018] As a preferred technical solution, the hydrogen-containing polysiloxane is an organopolysiloxane containing at least one Si-H bond, including end-containing hydrogen, side-containing hydrogen, or end-side-containing hydrogen structures, and its 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-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.

[0020] In view of the shortcomings of the prior art, the second objective of this invention is to provide a method for preparing silicone synthetic leather with foamed sponge, which is simple, suitable for large-scale industrial production, and environmentally friendly in the production process.

[0021] A method for preparing foamed sponge-based silicone synthetic leather includes the following steps:

[0022] (1) Ingredients: Weigh the required components of the first adhesive layer, the first adhesive layer, the sponge layer, the surface layer and the surface treatment layer according to the raw material ratio, and mix them evenly.

[0023] (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.

[0024] (3) Texture transfer and calendering: The surface material is coated onto the patterned release paper in sequence 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, the release film is covered, and the release film is heat-cured at 100-120℃ for 3-8 minutes; after cooling, the release film is peeled off, the adhesive layer material is coated again, and the release film is cured at 90-120℃ for 3-8 minutes; finally, the fabric base layer is laminated onto it through a wet lamination process to obtain a semi-finished product;

[0025] (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.

[0026] (5) Post-processing: Cool and roll up the surface-treated semi-finished product to obtain the foamed sponge silicone synthetic leather finished product.

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

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. This invention, through the introduction of a foamed sponge layer and a multi-layered composite structure design, enables synthetic leather to possess both high resilience and a soft touch similar to natural leather, while retaining the inherent excellent properties of organosilicon materials. It also exhibits excellent stain resistance, flame retardancy, and abrasion resistance. The dense cross-linked network formed by the Q units in the organopolysiloxane resin effectively improves the tear strength of the synthetic leather; simultaneously, the adhesive layer has strong adhesion, ensuring a firm bond between the substrate and functional layers, as well as between the various coatings. Through the rational proportioning of each component, the foamed sponge layer of this invention exhibits excellent resilience and flame retardancy, giving the overall synthetic leather material a full and highly elastic feel, meeting the comprehensive requirements of high-end soft synthetic leather for elasticity and deformation recovery. The synthetic leather of this invention can be widely used in soft-surface applications such as automotive interiors, high-end furniture, and yacht cabin walls.

[0030] 2. The preparation method of foamed sponge silicone synthetic leather is simple and efficient. It does not use or produce formaldehyde or other harmful substances during the production process, making it green and environmentally friendly. It is suitable for large-scale industrial production and has significant practical and promotional value. Attached Figure Description

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

[0032] Figure 2 These are before (left), middle (middle), and after (right) comparison images of the UL94 vertical burning test in Example 1.

[0033] Figure 3 This is a comparison of the Martindale abrasion resistance test results before (left) and after (right) in Example 1. Detailed Implementation

[0034] The following examples further illustrate the features of the present invention and other related features in detail, so as to facilitate understanding by those skilled in the art.

[0035] Example 1

[0036] Embodiment 1 of the present invention provides a foamed sponge silicone synthetic leather, which comprises, in sequence: a base layer (1.0 mm thick), 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 top layer (coating thickness 0.15 mm), and a surface treatment layer (coating thickness 0.1 mm).

[0037] The first / second adhesive layer comprises, by weight, 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 silica, and 0.8 parts of color paste.

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

[0039] The surface layer, by weight, comprises: 100 parts vinyl-terminated polysiloxane, 20 parts silica, 20 parts nylon powder, 0.5 parts platinum catalyst, 3 parts acetylene cyclohexanol, 3 parts hydrogen-containing polysiloxane, 0.8 parts color paste, and 60 parts resin.

[0040] The surface treatment layer comprises, by weight, 100 parts vinyl-terminated polysiloxane, 20 parts fumed silica, 20 parts matting agent, 1 part platinum catalyst, 2 parts acetylene cyclohexanol, 15 parts hydrogen-containing polysiloxane, 0.5 parts color paste, and 25 parts resin.

[0041] The preparation steps of the foamed sponge silicone synthetic leather in Example 1 include:

[0042] (1) Ingredients: Weigh out the required components for the adhesive layer, sponge layer, surface layer and surface treatment layer according to the raw material ratio, and mix them evenly.

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

[0044] (3) Texture transfer and calendering lamination: A surface layer material is coated onto the patterned release paper and cured at 110°C for 5 minutes to set the surface layer and completely replicate the pattern on the release paper. An adhesive layer material is then coated and cured at 120°C for 2 minutes. Subsequently, a sponge layer material is coated, and a release film is applied. The mixture is then heat-cured at 120°C for 5 minutes and cooled. After peeling off the release film, an adhesive layer material is coated again and cured at 120°C for 5 minutes. Finally, a fabric base layer is laminated onto the release paper using a wet lamination process to obtain a semi-finished product.

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

[0046] (5) Post-processing: Cool the surface-treated semi-finished product and roll it up to obtain the foamed sponge silicone synthetic leather product of Example 1.

[0047] Example 2

[0048] Embodiment 2 of the present invention provides a foamed sponge silicone synthetic leather, which comprises, in sequence: a base layer (1.0 mm thick), a first adhesive layer (coating thickness 0.1 mm), a sponge layer (foaming 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 composition of the first / second adhesive layer is the same as in Example 1.

[0050] The sponge layer comprises, by weight, 100 parts vinyl-terminated polysiloxane, 30 parts calcium carbonate, 1.5 parts platinum catalyst, 20 parts resin, 1 part acetylenecyclohexanol, 0.8 parts color paste, 8 parts hydrogen-containing polysiloxane, 3 parts KH-570, 40 parts hydroxyl-terminated polydimethylsiloxane, 40 parts 1,3-benzene disulfonyl hydrazine, and 3 parts glycerol.

[0051] The surface layer, by weight, comprises: 100 parts vinyl-terminated polysiloxane, 25 parts silica, 0.5 parts platinum catalyst, 3 parts acetylene cyclohexanol, 3 parts hydrogen-containing polysiloxane, 0.8 parts color paste, and 60 parts resin.

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

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

[0054] (1) Ingredients: Weigh out the required components for the adhesive layer, sponge layer, surface layer and surface treatment layer according to the mass parts, and mix them evenly.

[0055] (2) Mixing: The above-mixed adhesive layer, sponge layer, surface layer and surface treatment layer raw materials are subjected to cold refining and hot refining respectively. The cold refining temperature is 30℃ and the time is 5 hours; the hot refining temperature is 110℃ and the time is 0.5 hours.

[0056] (3) Texture transfer and calendering lamination: A surface layer material is coated onto the patterned release paper and cured at 120°C for 3 minutes to set the surface layer and completely replicate the pattern on the release paper. An adhesive layer is then coated and cured at 90°C for 5 minutes. Subsequently, a sponge layer material is coated, and a release film is applied. The mixture is then heat-cured at 120°C for 5 minutes and cooled. After peeling off the release film, an adhesive layer is applied again and cured at 110°C for 5 minutes. Finally, a fabric base layer is laminated onto the release paper using a wet lamination process to obtain the semi-finished product.

[0057] (4) Surface treatment: Coat the surface treatment layer material on the patterned surface of the surface layer and treat it at 140°C for 5 minutes.

[0058] (5) Post-processing: Cool the surface-treated semi-finished product and roll it up to obtain the foamed sponge silicone synthetic leather product of Example 2.

[0059] Example 3

[0060] Embodiment 3 of the present invention provides a foamed sponge silicone synthetic leather, which comprises, in sequence: a base layer (1.0 mm thick), 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 top layer (coating thickness 0.15 mm), and a surface treatment layer (coating thickness 0.1 mm).

[0061] The first / second adhesive layer comprises, by weight, 100 parts vinyl-terminated polysiloxane, 8 parts resin, 1 part platinum catalyst, 1 part acetylene cyclohexanol, 8 parts hydrogen-containing polysiloxane, 40 parts fumed silica, and 0.8 parts color paste.

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

[0063] The surface layer, by weight, comprises: 100 parts vinyl-terminated polysiloxane, 40 parts silica, 1.5 parts platinum catalyst, 1 part dimethyl maleate, 8 parts hydrogen-containing polysiloxane, 0.8 parts color paste, and 90 parts resin.

[0064] The surface treatment layer comprises, by weight, 100 parts vinyl-terminated polysiloxane, 20 parts matting agent, 0.8 parts platinum catalyst, 3 parts polyvinyl polysiloxane, 12 parts hydrogen-containing polysiloxane, 0.8 parts color paste, and 28 parts resin.

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

[0066] (1) Ingredients: Weigh out the required components for the adhesive layer, sponge layer, surface layer and surface treatment layer according to the mass parts, and mix them evenly.

[0067] (2) Mixing: The above-mixed adhesive layer, sponge layer, surface layer and surface treatment layer raw materials are subjected to cold refining and hot refining respectively. The cold refining temperature is 30℃ and the time is 5 hours; the hot refining temperature is 110℃ and the time is 0.5 hours.

[0068] (3) Texture transfer and calendering lamination: A surface layer material is coated onto the patterned release paper and cured at 120°C for 3 minutes to set the surface layer and completely replicate the pattern on the release paper. An adhesive layer is then coated and cured at 100°C for 5 minutes. Subsequently, a sponge layer material is coated, and a release film is applied. The mixture is then heat-cured at 120°C for 5 minutes and cooled. After peeling off the release film, an adhesive layer is applied again and cured at 120°C for 5 minutes. Finally, a fabric base layer is laminated onto the release paper using a wet lamination process to obtain the semi-finished product.

[0069] (4) Surface treatment: Coat the surface treatment layer material on the patterned surface of the surface layer and treat it at 150°C for 3 minutes.

[0070] (5) Post-processing: Cool the surface-treated semi-finished product and roll it up to obtain the foamed sponge silicone synthetic leather product of Example 3.

[0071] Example 4

[0072] The foamed sponge silicone synthetic leather provided in Example 4 is basically the same as that in Example 1, except that the sponge layer formulation is different. The sponge layer of Example 4 includes, by weight, 100 parts vinyl-terminated polysiloxane, 80 parts aluminum hydroxide, 0.5 parts platinum catalyst, 30 parts resin, 2.5 parts acetylenecyclohexanol, 0.8 parts color paste, 3 parts hydrogen-containing polysiloxane, 5 parts A-172, 45 parts hydroxyl-terminated polydimethylsiloxane, 30 parts 1,3-benzenedisulfonyl hydrazine, and 4 parts water.

[0073] Example 5

[0074] The foamed sponge silicone synthetic leather provided in Example 5 is basically the same as that in Example 1, except that the formulation of the surface layer is different. The surface layer of Example 5 includes, by weight, 100 parts of vinyl-terminated polysiloxane, 25 parts of silica, 0.5 parts of platinum catalyst, 3 parts of hydrogen-containing polysiloxane, 0.8 parts of colorant, and 40 parts of resin.

[0075] Example 6

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

[0077] The resins in Examples 1-6 and Comparative Examples 1-6 are branched organopolysiloxanes containing at least one Q unit.

[0078] Comparative Example 1

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

[0080] Comparative Example 2

[0081] The silicone synthetic leather provided in Comparative Example 2 omits the coating and curing steps of the adhesive layer in the calendering and bonding process, and other specific implementation methods are basically the same as those in Example 1.

[0082] Comparative Example 3

[0083] The silicone synthetic leather provided in Comparative Example 3 replaces the silica in the adhesive layer with an equal amount of vinyl-terminated polysiloxane. Other specific implementation methods are basically the same as in Example 1.

[0084] Comparative Example 4

[0085] The silicone synthetic leather provided in Comparative Example 4 does not contain hydroxyl-terminated polydimethylsiloxane in the sponge layer, and other specific implementation methods are basically the same as those in Example 1.

[0086] Comparative Example 5

[0087] The silicone synthetic leather provided in Comparative Example 5 does not contain resin in the surface layer, and other specific implementation methods are basically the same as those in Example 1.

[0088] Comparative Example 6

[0089] The silicone synthetic leather provided in Comparative Example 6 does not contain matting powder in the surface treatment layer, and other specific implementation methods are basically the same as those in Example 1.

[0090] Performance testing

[0091] 1. Hand feel test: Under the standard environment of temperature (23±2)℃ and humidity (50±5)%, place the palm flat on the surface of the foamed sponge silicone synthetic leather sample and rub it back and forth with uniform force. According to the touch, the sample is graded as follows: qualified, dry and smooth; average, dry and slightly rough; unqualified, cold and rough.

[0092] 2. Stain Resistance Test: Cut three 100×200mm samples, avoiding defects such as blemishes, spots, and stains. Use a Chenguang ballpoint pen No. 6546 and a Deli marker No. 6824 to draw on the samples, then wipe them with a cleaning agent (20% ethanol solution) and a soft cloth. According to the Q / JLY J7110614B-2015 standard, rate the degree of residual stains, with level 5 being the best (no residue) and level 1 being the worst (cannot be wiped off).

[0093] 3. Hardness Test: A Shore hardness tester was used, and the test was conducted according to GB / T531.1-2008 standard. The sample was an intact foamed silicone synthetic leather, and the test was performed on the backing side. At least 5 measurements were taken at different locations, and the average value was recorded.

[0094] 4. Expansion Ratio Test: The apparent density of the sample is measured according to GB / T6343-2009 standard. Expansion ratio = Raw material density / Apparent density of sample.

[0095] 5. Foaming pore size: The cross-section of the sample was observed using a digital electron microscope at a magnification of 200x, and the average pore size was measured using a ruler.

[0096] 6. Flame retardancy test: The flame retardancy of synthetic leather is evaluated using the UL 94 standard, with at least 3 specimens tested for each instance.

[0097] 7. Tensile strength: The synthetic leather was cut into I-shaped dumbbells, and the tensile strength of each sample was tested according to GB / T 528-2009 standard.

[0098] 8. Tear strength: Cut the synthetic leather into standard right-angled specimens and test the tear strength according to GB / T 529-2008.

[0099] 9. Abrasion resistance test: The Martindale method was adopted according to GB / T13775 standard. SM-25 wool fabric was used, and the surface treatment layer was rubbed 30,000 times under a load of (12±0.2) kPa. The appearance rating was as follows: Grade 5: Clear texture, no obvious wear; Grade 4: Slight change in gloss, clear texture; Grade 3: Surface texture is visible but has been worn smooth / faded, and the intermediate coating shows wear; Grade 2: Severe wear of the texture, and obvious damage to the intermediate coating; Grade 1: Coating worn through, completely exposing the fabric base layer.

[0100] 10. Abrasion resistance test: The Taber method was adopted according to the ASTM-D3884 standard. An H-22 type grinding wheel was selected, a load of 1 kg was applied, and after 200 rubs, the appearance was rated as follows: Grade 5: No visible wear on the coating, no change in gloss and haze; Grade 4: The coating texture is basically intact, and the gloss and haze are slightly changed; Grade 3: The coating texture is visible but worn, and the texture is still clear; Grade 2: The coating is severely worn, and the texture is basically worn flat; Grade 1: The coating is worn through, exposing the fabric base layer.

[0101] Table 1 shows the performance test results of the synthetic leather in the examples and comparative examples.

[0102]

[0103]

[0104] Table 2 shows the performance test results of the synthetic leather in the examples and comparative examples.

[0105] 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] As shown in Tables 1 and 2, compared with Example 1, Comparative Example 1 has a significantly lower foaming ratio, smaller pore size, higher hardness, and extremely poor abrasion resistance. This indicates that an appropriate foaming ratio is a key factor in giving synthetic leather a soft feel, suitable hardness, and excellent abrasion resistance.

[0107] Comparative Example 2 showed that the foam had a poor feel, low expansion ratio, high hardness, and poor wear resistance. This indicates that the lack of an adhesive layer affects the expansion ratio of the foamed sponge layer and is crucial to its performance. The lack of an adhesive layer not only reduces the interlayer bonding force, but more importantly, it cannot form an effective gas barrier layer, causing gas to escape during the foaming process, resulting in the collapse of the cell structure and ultimately a reduced expansion ratio, smaller and unevenly distributed cells.

[0108] Comparative Example 3 exhibited the lowest tensile strength, low tear strength, and poor abrasion resistance among the samples, indicating that silica, as a key reinforcing filler, can significantly enhance the mechanical strength and durability of synthetic leather. Simultaneously, its foaming ratio was significantly reduced, suggesting that silica also acts as a nucleating agent during the foaming process, contributing to the formation of uniform cells and ensuring the foaming ratio.

[0109] Comparative Example 4 is similar to Example 1 in terms of hardness and strength, but has a lower foaming ratio and a less desirable feel. This indicates that the hydroxyl-terminated polydimethylsiloxane has an effect on the formation of a uniform and stable cell structure in the sponge layer, and also affects the degree of cross-linking of the sponge layer, resulting in a decrease in the tear strength of the synthetic leather.

[0110] The tear strength of Comparative Example 5 was significantly reduced, the abrasion resistance of Martindale decreased, and the flame retardant rating also decreased. This indicates that the resin in the top layer not only helps to improve the mechanical properties and abrasion resistance of the coating, but also the organic polysiloxane resin containing Q units can form a dense three-dimensional cross-linked network, which can effectively improve the tear strength of the coating.

[0111] Comparative Example 6 had an unsatisfactory feel, and its tear strength and abrasion resistance were significantly reduced. This indicates that the matte powder in the surface treatment layer not only provides an aesthetic effect, but also effectively improves the density and mechanical strength of the coating, making it a key component that gives the product a good feel, abrasion resistance, and scratch resistance.

[0112] As demonstrated in Examples 1-6, this invention successfully produces high-performance foamed sponge silicone synthetic leather with a soft feel, excellent mechanical properties, outstanding abrasion resistance, and good flame retardancy through the synergistic design and preparation of multifunctional layers such as adhesive layers, foamed sponge layers, surface layers, and surface treatment layers. The comparative examples, on the other hand, verify from the opposite perspective that the absence of any key component or process will have a significant adverse impact on the overall performance of the final product.

[0113] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

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; 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; the foaming agent is one or more of sodium bicarbonate, 1,3-benzenedisulfonyl hydrazine, and p-toluenesulfonyl hydrazine; the foaming aid is one or more of water, methanol, ethanol, ethylene glycol, glycerol, benzyl alcohol, or lauryl alcohol; the resin is a branched organopolysiloxane containing at least one Q unit. The method for preparing the foamed sponge-based silicone synthetic leather is characterized by comprising the following steps: (1) Ingredients: Weigh out the required components of 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: The surface material is coated onto the patterned release paper in sequence and cured at 110~130℃ for 3~5 minutes to fix 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, the release film is covered, and the release film is heat-cured at 100~120℃ for 3~8 minutes; after cooling, the release film is peeled off, the adhesive layer material is coated again and cured at 90~120℃ for 3~8 minutes; finally, the fabric base layer is laminated onto it through a wet composite process to obtain a semi-finished product; (4) Surface treatment: Apply surface treatment material to 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.

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 resin is a branched organopolysiloxane containing at least one Q unit; 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 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 colorant; the resin is a branched organopolysiloxane containing at least one Q unit; the surface layer coating thickness is 0.1-0.2 mm.

4. 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 colorant; the resin is a branched organopolysiloxane containing at least one Q unit; the coating thickness of the surface treatment layer is 0.05-0.2 mm.

5. 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%.

6. 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.

7. 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%.

8. The foamed sponge-like silicone synthetic leather according to claim 1, 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%.

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