CN103821008A - Organosilicon synthetic leather adopting three-layer structure and preparation method thereof - Google Patents

Abstract

The invention discloses a three-layer organic silicon synthetic leather and a preparation method thereof. The organic silicon synthetic leather is sequentially bonded by base material, bottom glue and surface glue; the three-layer organic silicon synthetic leather of the present invention Synthetic leather through the rational design of the chemical composition of the bottom layer glue and the surface layer glue, the bottom layer glue provides firm interlayer adhesion for the two connecting surfaces under the joint action of various chemical reactions, and endows the silicone synthetic leather with soft and smooth characteristics ;The surface layer rubber endows the silicone synthetic leather with dry and wear-resistant characteristics, so that the silicone synthetic leather can reduce dust absorption, improve wear resistance, scratch resistance, scratch resistance and other characteristics.

Description

Organosilicon synthetic leather with three-layer structure and preparation method thereof

technical field

The invention belongs to the technical field of synthetic leather. More specifically, the invention relates to a three-layer organosilicon synthetic leather with soft, smooth, dry and wear-resistant properties and a preparation method thereof.

Background technique

Silicone synthetic leather is a composite material composed of textile (or synthetic leather) base material, primer glue, surface glue and surface coating layer bonded in sequence.

Compared with the very popular and best-selling polyurethane synthetic leather in the market, silicone synthetic leather has not achieved substantial promotion. The fundamental reason is the excellent cost performance of polyurethane synthetic leather. However, polyurethane synthetic leather always has defects in toxicity, environmental protection, weather resistance and water resistance, while silicone materials have environmental protection, weather resistance and hydrophobic properties, so silicone synthetic leather has always been regarded as a potential value. alternatives. Although silicone synthetic leather and polyurethane synthetic leather resin are basically similar in terms of production process, equipment and auxiliary materials, due to the obvious differences in the chemical structure and material properties of the two basic resins, it is actually difficult for silicone synthetic leather to simply replace polyurethane Synthetic Leather.

Silicone materials are inorganic main chains composed of -Si-O- basic units, and the side chains are connected to various other organic groups through silicon atoms, which has both the properties of inorganic materials and organic materials. Compared with polyurethane materials, the most prominent properties of silicone materials are high and low temperature resistance, weather resistance, electrical insulation, low surface tension, low cohesive energy and physiological inertness, which can endow silicone artificial leather with environmental protection, hydrophobicity, anti-fouling, It has the advantages of softness, wrinkle resistance, aging resistance and high and low temperature resistance, but it also causes a series of new problems such as high surface friction, easy to absorb dust, poor bonding strength, poor wear resistance and poor scratch resistance. One of the fundamental reasons restricting its development.

Silicone materials appeared about ten years later than polyurethane materials, and their total scale is much smaller than the latter. However, its development does not depend on the oil industry. Today, with the decreasing oil and the rising calls for environmental protection, silicone synthetic leather is facing great challenges. Good opportunity for development. In the process of existence and development compared with polyurethane leather, silicone leather must solve the above problems in order to reflect its advantages in environmental protection, hydrophobicity, anti-fouling, suppleness, wrinkle resistance, aging resistance and high and low temperature resistance.

As early as June 29, 1964, US3434875A applied for a patent for a silicone-coated textile with the invention name "Textilefabriccoatedwith a high molecular weight methylpolysiloxane elastomer polymer". The composite silicone rubber layer occupies the highest percentage of the dry textile itself. Up to 30% achieves some effect in breathability, washability, abrasion resistance and wrinkle resistance, but does not provide proof of dust resistance and slippery feel.

US4478895 shows that silicone resin/silicone rubber/textile three-layer structure silicone leather has been well known, and the leather with the resin layer is soft and bendable, and the surface has strong dust resistance. But the patent does not mention the contribution of the resin in terms of wear resistance and slippery feel.

CN1210170A has invented a textile fabric with at least two layers of silicone coating, the first layer directly coated on the fabric has an elongation at break of at least 400%, and the second layer has a tear strength of at least 30kN/m, It is suitable as a car inflatable airbag. The invention mentions that a low-friction material, such as an elastoplastic polyorganosiloxane resin, can be added on top of the second layer to provide a smooth and dry surface. However, it has not been emphasized and described that the resin has a very necessary effect on the final performance of the product.

CN1372610A has invented a textile fabric coated with silicone rubber, which is preferably used on textile fabrics coated with elastomer coatings to form a flexible coating with a weight of 15 grams per square meter on its surface and reduce friction. More suitable for automobile inflatable airbags. The smooth feeling of the coating on the fabric comes from the addition of soft layered fillers, but the flake fillers will obviously lose the mechanical strength of the material.

CN100400678C invented a fluorine-containing resin composition, which has good soft texture, stain resistance and wear resistance. The cost of this solution is relatively expensive, and the surface containing fluorine is more difficult to bond, and the application range is limited.

Patents such as CN1194280A, CN1292020A, CN100422279C, CN1702234A, CN1927973A, CN1927973A and CN101680162A apply for protection from different angles to improve the adhesion of silicone rubber to textiles. The disadvantage is that the wear resistance, smoothness and anti-dust absorption of the surface material are not described, and the practicability is not good.

CN201342821Y, CN1021174262A and CN202247476U etc. have invented the use of release film, embossing treatment and additional decorative adhesive layer to give silicone leather surface lines and patterns, but they have not stated that additional layers have effects on wear resistance, smoothness and anti-adsorption dust. any improvements.

To sum up, the previous work started from different application directions and proposed some solutions to the problems of silicone leather in terms of slippery feeling, dust absorption resistance, adhesive strength, wear resistance and scratch resistance, etc. Clearly and completely propose a technical solution that can comprehensively solve the problems of high surface friction, easy to absorb dust, poor bonding strength, poor wear resistance and poor scratch resistance in silicone synthetic leather composite materials.

Contents of the invention

Based on this, in order to overcome the defects of the above-mentioned prior art, the present invention provides a three-layer organic silicon synthetic leather with soft, smooth, dry and wear-resistant properties and a preparation method thereof.

In order to realize the above-mentioned purpose of the invention, the present invention adopts the following technical solutions:

A three-layer organic silicon synthetic leather, wherein the organic silicon synthetic leather is formed by sequentially bonding a base material, a bottom layer glue and a surface layer glue;

Described base glue comprises the component of following mass percentage:

Described surface glue comprises the component of following mass percentage:

Wherein: the vinyl-containing polydimethylsiloxane is a polydimethylsiloxane in which at least two vinyl groups are directly connected to Si, and the vinyl groups are located at chain ends and/or side chains;

The Si-H group-containing crosslinking agent is polydimethylsiloxane with at least 3 hydrogen atoms directly connected to Si, the hydrogen atoms are located at the chain ends and/or side chains, and the hydrogen atom content is 0.1 ~1.6%; the Si-H group-containing crosslinking agent is linear, branched, cyclic or a mixture thereof;

The block-type silicone resin is obtained by polycondensation reaction of a hydrolyzed prepolymer of a silicone monomer mixture with a structure of R _n SiX _4-n and a linear polysiloxane with a structure of X(R ₂ SiO) _m X A copolymer; wherein n=0,1,2,3; m=100~1000; the molar ratio of R ₃ SiX chain unit to SiX ₄ chain unit is 0.7~0.9, and the vinyl content is 1~10%;

The platinum catalyst is chloroplatinic acid isopropanol solution, chloroplatinic acid tetrahydrofuran solution, chloroplatinic acid-divinyltetramethyldisiloxane complex, or chloroplatinic acid-1, 3, 5, 7-tetra Vinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane complex, the content of Pt atoms in the platinum catalyst is 100-500000ppm;

The inhibitor is alkynyl alcohol compound such as methyl butynyl alcohol, ethynyl cyclohexanol, alkyne-containing maleic acid or its derivatives, alkyne-containing fumaleic acid or its derivatives; polyvinyl Polysiloxane; compounds containing N atoms such as pyridine, or unsaturated amides; compounds containing P atoms such as organic phosphines or phosphites;

The filler is hydrophobic or hydrophilic silica, fumed silica, hydrophobic fumed silica, titanium dioxide, calcium carbonate, aluminosilicate, aluminum oxide, aluminum hydroxide, magnesium hydroxide or a mixture thereof;

The tackifier is γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltriethoxysilane, 2-(3, 4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, or a combination thereof, or a compound or combination thereof Partial hydrolyzate;

The color paste is a pigment using vinyl polydimethylsiloxane as a dispersion medium;

The accelerator is a metal chelate, titanate, zirconate, or carboxylate of Zn, Ba, Ca, Mn, or a mixture of the above compounds;

The organic solvent is an organic solvent with low boiling point, good compatibility and volatility, which plays the role of diluting and reducing viscosity, and is C ₅ -C ₃₀ alkanes and/or aromatics, C ₅ -C ₃₀ ethers and/or Esters, or mixtures of the above compounds, or volatile siloxane oligomers, such as octamethylcyclotetrasiloxane. Solvent molecules containing heteroatoms such as N, P, and S will inhibit the hydrosilylation reaction. In principle, avoid the use of such solvents, but a small amount is not excluded.

In some of these embodiments, the base gum is mixed with fumed silicon dioxide and vinyl silicone oil in a kneader at a weight ratio of 20-40:60-80, during which hexamethylsilazane, water and 0.1 ～3% hydroxyl content 3～15% small molecule hydroxyl silicone oil is obtained by treating the silicon hydroxyl on the surface of fumed silica; the raw material, surface treatment process and machinery and equipment of the base rubber affect its reinforcement, transparency and fluidity Very large, this is familiar to the industry.

In some of these embodiments, the linear polysiloxane constituting the soft segment of the block type silicone resin has m=100-800, more preferably m=500-600; the silicone oil with m=100-1000 has a moderate viscosity , the size ratio of the soft and hard segments of silicone resin is relatively appropriate, and it is easy to control the softness and hardness. The vinyl content is 2.7-5.4%.

In some of the embodiments, the vinyl-containing polydimethylsiloxane is α,ω-vinyl polydimethylsiloxane with a viscosity of 2000-100000 mPa.s.

In some of the embodiments, the viscosity of the α,ω-vinyl polydimethylsiloxane is 10000-50000 mPa.s. After the viscosity is mixed with fillers, the viscosity is moderate, and the mechanical properties can meet the general requirements.

In some embodiments, the hydrogen atoms of the Si-H group-containing crosslinking agent are located in side chains, and the hydrogen atom content is 0.2-0.75%.

In some of these embodiments, the platinum catalyst is chloroplatinic acid-divinyltetramethyldisiloxane complex; the content of Pt atoms in the platinum catalyst is 2000-5000ppm; the inhibitor is methyl butynyl alcohol, ethynylcyclohexanol, or tetramethyltetravinylcyclotetrasiloxane;

In some of the embodiments, the filler is hydrophobic fumed silica, and the specific surface area of the filler is 150-400 m ² /g.

In some of the embodiments, the filler has a specific surface area of 250-300 m ² /g. The specific surface area is high and the reinforcing effect is good, but the viscosity of the bottom layer is high and the coating is difficult; the specific surface area is small and the reinforcing effect is poor, but the viscosity of the bottom layer is low and the coating is convenient, but the strength of the obtained synthetic leather is poor; It is preferably 150 to 400 m ² /g, more preferably 250 to 300 m ² /g.

In some of the embodiments, the color paste is a pigment using α,ω-vinyl polydimethylsiloxane as a dispersion medium. Color paste with α, ω-vinyl polydimethylsiloxane as the dispersion medium. This type of silicone oil contains vinyl, so it participates in the cross-linking reaction, which makes the mechanical properties of the rubber good and the color fastness of the leather is good.

In some of these embodiments, the accelerator is aluminum acetylacetonate, zirconium butoxide, zirconium isopropoxide, n-butyl titanate, isopropyl titanate, or t-butyl titanate. More preferably, it is tert-butyl titanate, which has moderate catalytic activity and good solubility, and can significantly improve the adhesion of the primer to the substrate.

In some of the embodiments, the organic solvent is C ₅ -C ₁₆ alkanes or aromatic hydrocarbons, or cyclosiloxane.

In some of the embodiments, the organic solvent is C ₆ -C ₉ mixed alkanes.

The present invention also provides the preparation method of the organic silicon synthetic leather of above-mentioned three-layer structure, adopts surface layer adhesive and bottom layer adhesive of the present invention to carry out coating, coating method can be by spraying method, scraper method, screen printing method, dip coating method , transfer coating and other known methods. Specifically include the following steps:

(1) Coat the surface layer glue on the release paper, the traveling speed is 3-30m/min, the baking temperature is 80-150℃, and the baking time is 1-10min;

(2) Coat the bottom layer glue on the surface layer glue that has been cured, and combine it with the base material under the action of the pressure roller; the speed of travel is 3-30m/min, the baking temperature is 80-150°C, and the baking The time is 5-10 minutes;

(3) peel off the release paper to obtain the organosilicon synthetic leather with the three-layer structure.

In some of these embodiments, the baking temperature in step (1) is 100-130°C, and the baking time is 3-5 minutes; the baking temperature in step (2) is 100-130°C, and the baking time is 5 to 8 minutes. In this step, under the condition that the solvent is volatilized thoroughly, the degree of vulcanization can be complete or incomplete, preferably an incomplete state of vulcanization, and this preferred baking temperature and baking time make the vulcanization in an incomplete state, thereby improving the The unreacted vinyl and Si-H groups in the surface glue and the corresponding groups in the bottom glue produce chemical reaction adhesion between the layers, which is beneficial to improve the wear resistance, scratch resistance and resistance of the silicone synthetic leather surface. Scratch performance, imparts a long-lasting slippery feel to the leather surface.

Liquid silicone rubber is known for its low surface energy, mold release properties, and poor adhesion to substrates, especially materials such as polyesters, polyamides, and polyolefins. Silicone rubber elastomer has a large surface friction coefficient and has anti-slip effect; low surface energy, easy to absorb dust; poor mechanical strength, so wear resistance, scratch resistance and scratch resistance are not good. However, silicone resin has high strength and smoothness, and has been used to coat silicone rubber elastomers for a long time. The main point is to use thinner thickness and different patterns while maintaining strong adhesion. It imparts a dry and smooth feeling to the surface of the product, as well as properties such as wear resistance, scratch resistance and scratch resistance.

Therefore, the realistic requirement is that the primer must be able to provide reliable adhesion for the two bonding surfaces between the three layers of materials. Based on the above theory, the present invention proposes a silicone synthetic leather with a three-layer structure of substrate (various textiles or non-woven fabrics), bottom glue and surface glue, wherein the bottom glue applied to the substrate is an adhesive liquid Silicone rubber, its cured product is a soft and smooth elastomer, the viscosity of the bottom glue is 50000-100000mPa.s, it is easy to use a scraper to coat, the coating has high flatness and less air bubbles; the surface glue applied on the bottom glue It is a block-type silicone resin coating, and its cured product is a dry and wear-resistant hard coating. The solid content of the surface layer adhesive is 20-50%. The low viscosity is good for leveling and easy to fill with release paper. Finely textured and forms a well-textured, wear-resistant coating.

The present invention improves interlayer adhesion by greatly increasing the ratio of the number of crosslinking agent Si-H groups in the primer to the ratio of Si-vinyl groups in vinyl silicone oil, and adding tackifiers and accelerators containing epoxy groups. relay. The chemical reactions that produce bonding include the following basic types:

1. Excessive Si-H groups of the crosslinking agent can undergo dehydrogenation reactions with the hydroxyl, carboxyl and amino groups on the surface of the substrate and produce chemical bonds.

2. Under the action of the accelerator, the epoxy group in the tackifier undergoes a ring-opening reaction with the hydroxyl, carboxyl and amino groups on the surface of the substrate, and the generated alkoxy anion can continue to react with the above groups, or trigger other rings. Oxygen ring-opening polymerization eventually forms a cross-linked network.

3. The siloxane group in the tackifier can react with the hydroxyl group on the surface of the substrate after hydrolysis.

4. Excessive crosslinking agent Si-H groups can also directly react with epoxy groups to promote the ring-opening reaction of epoxy to form a crosslinked network.

5. Excessive Si-H groups and vinyl groups in the resin-based surface layer adhesive undergo a hydrosilylation chemical reaction under the action of a platinum catalyst to form a good interlayer adhesion.

It is not excluded here, and it is preferred to use low-viscosity Si-H-based cross-linking agents and tackifiers to penetrate the substrate. After moderate penetration, a chemical reaction occurs to form an interpenetrating structure with the substrate to better provide layers. inter-adhesion.

The organosilicon synthetic leather of the present invention provides the abrasion resistance and smoothness of the synthetic leather surface through the surface layer adhesive. If there is too little organic solvent in the surface layer adhesive, it will cause the surface layer adhesive to be too thick and cause the surface layer to be relatively hard. The softness of silicone synthetic leather is reduced. Therefore, the present invention rationally designs the chemical composition of the surface glue, so that the synthetic leather has the characteristics of wear resistance and smoothness.

The primer adhesive and the surface adhesive of the present invention can be prepared by mixing each component in sequence, only need to arrange the platinum catalyst after the inhibitor is added and mixed evenly. In general, for the sake of storage stability and ease of use, a two-component package is used to store the platinum catalyst and the Si-H-based cross-linking agent separately from each other. When using, mix them uniformly in a certain proportion and use them up within a certain period of time. .

Compared with the prior art, it has the following beneficial effects:

The organic silicon synthetic leather with three-layer structure of the present invention rationally designs the chemical composition of the bottom glue and the surface glue. Silicone synthetic leather is soft and smooth; the surface layer rubber endows silicone synthetic leather with dry and wear-resistant characteristics, so that silicone synthetic leather can reduce dust absorption and improve wear resistance, scratch resistance, and scratch resistance.

Detailed ways

The present invention will be described in detail below in conjunction with specific embodiments. Parts and percentages used in the following examples are by weight unless otherwise specified.

In the following preparation process, if there is no special instruction, existing conventional technology is adopted.

The color pastes used in the following examples were purchased from Shenzhen Tyco Technology Co., Ltd. Other raw materials used were commercially available unless otherwise specified.

Examples 1 to 4 are organic silicon synthetic leather with a three-layer structure and its preparation method. The formulations and preparation methods of Examples 1 to 4 are the same, except that the m values of the block silicone resins are different, which are 100, 500, 800 and 1000 to investigate the effect of m value on the softness and abrasion resistance of silicone synthetic leather.

Example 1

The organosilicon synthetic leather of the three-layer structure of the present embodiment is formed by sequentially bonding the base material, the bottom layer glue and the surface layer glue; the bottom layer glue includes the following components in mass percentage:

Surface glue includes the following components in mass percentage:

In the above-mentioned bottom layer adhesive and surface layer adhesive, polydimethylsiloxane containing 3 hydrogen atoms of Si-H-based cross-linking agent directly connected to Si, the hydrogen atoms are located in the side chain, the content of hydrogen atoms is 0.5%, and the cross-linking The agent is linear;

In the above-mentioned primer and surface glue, the platinum catalyst is a chloroplatinic acid-divinyltetramethyldisiloxane complex, and the content of Pt atoms is 2000ppm;

In the above surface layer adhesive, the molar ratio of R ₃ SiX chain unit to SiX ₄ chain unit is 0.7, and the vinyl content is 2.7%; in the linear polysiloxane X(R ₂ SiO) _m X, m=100.

The preparation of bottom glue and surface glue described in the present embodiment are respectively as follows:

1. Bottom glue

Preparation of base gum:

1) Put 600kg of vinyl silicone oil with a viscosity of 40000mPa.s into the kneader and start stirring;

2) Add 300kg of fumed silica with a specific surface area of 300m ² /g, 90kg of hexamethylsilazane and 9kg of water in three batches, close the top cover of the kneader after the addition, and continue stirring for 2 hours;

3) Turn on the temperature rise switch, set the temperature at 150°C, and turn on the vacuum pump at the same time, and keep the vacuum at about -0.095MPa;

4) Start timing when the temperature reaches 150°C, and continue vacuuming for 2 hours;

5) Stop heating, turn off the vacuum pump, stop stirring, and start stirring when it is naturally cooled to 90°C, add small molecule hydroxyl silicone oil with a hydroxyl content of 8% accounting for 0.5% of the weight of fumed silica, and turn on the vacuum pump after mixing for 0.5 hours. Keep around -0.095MPa for 0.5 hours;

6) Stop heating, turn off the vacuum pump, stop stirring, and discharge when it is naturally cooled to 60°C;

7) Store the base rubber in an iron bucket, cover it and save it for later use.

Preparation of bottom glue:

Turn on the planetary mixer, put in the corresponding amount of α, ω-vinyl polydimethylsiloxane, base glue, Si-H-based crosslinking agent, inhibitor, color paste and tackifier, and stir for 0.5 hours. Continue to add accelerator and platinum catalyst and stir for 10 minutes. Turn on the vacuum pump, and keep the vacuum degree at about -0.095MPa for 5 minutes. Turn off the vacuum pump and discharge the material after returning to normal pressure.

2. Surface glue

Preparation of block type silicone resin:

The organosilicon monomer with the structure of R _n SiX _4-n (n=0,1,2,3) (the molar ratio of R ₃ SiX chain unit to SiX ₄ chain unit is 0.7, and the vinyl content is 2.7%), With linear polysiloxane with X(R ₂ SiO) _m X (m=100) structure, in the presence of aromatics, through alcoholysis (methanol, ethanol, isopropanol), hydrolysis, catalytic polycondensation, catalytic equilibrium and other processes , this process is to first carry out alcoholysis and hydrolysis of the mixed monomers of R _n SiX _4-n (n=0,1,2,3) to obtain a silicone resin prepolymer with a certain rigid structure, and then Polycondensation reaction with X(R ₂ SiO) _m X (m=100) in the presence of a catalyst to obtain a block copolymer composed of rigid silicone resin and flexible linear polysiloxane, hereinafter referred to as block type Silicone resin.

Preparation of surface glue:

Turn on the planetary mixer, put in the corresponding amount of organic solvent, block type silicone resin, base glue, Si-H-based crosslinking agent, inhibitor and color paste, and stir for 2 hours. Continue to drop in the platinum catalyst, and discharge after stirring for 10 minutes.

The preparation method of the organosilicon synthetic leather of the three-layer structure of the present embodiment comprises the following steps:

(1) Coat the surface layer glue on the release paper, the traveling speed is 3m/min, the baking temperature is 120°C, and the baking time is 2min;

(2) Coating the bottom glue on the cured surface glue, and compounding it with the base material (in this embodiment, the base material is a superfiber) under the action of a pressure roller; the speed of travel is 3m/min, The baking temperature is 120°C, and the baking time is 10 minutes;

(3) Peel off the release paper and roll it up to obtain a three-layer organosilicon synthetic leather with a certain pattern and decorative pattern.

The organosilicon synthetic leather of the three-layer structure prepared by embodiment 1-4 has been tested as follows:

1. Folding fastness

The folding fastness is tested according to the regulations of QB/T2714-2005. Cut two sets of samples along the width direction, each piece has 2 sets, the surface layer of the sample is folded inward, and the two sets of samples are respectively folded at (23±2)°C for 200,000 times and (-10±1)°C for 2.5 Ten thousand times, and then observe the changes of the surface and inner parts of the folded part, and observe whether there are cracks.

2. Wear resistance

The test is carried out according to the regulations of QB/T2726-2005, using CS-10 grinding wheel, the test condition load is 1000g, and the test rotation number is 1000 revolutions.

Evaluation Standards:

Level 1 is obvious

Level 2 is more obvious

Level 3 can distinguish

Grade 4 indistinguishable

Level 5 can't tell

3. Heat-resistant adhesion

According to QB/T1646-2007, the surface layers of the two samples are stacked together, sandwiched between two pieces of 60-60-3mm glass, and then pressed on the glass with a weight of 3kg. Place it in a blast oven at 100±2°C, take it out after 1 hour, remove the weight, and place it at room temperature for 1 hour, then gently uncover the paired sample by hand.

Result judgment:

Level 5 No change in the surface layer

Grade 4 gloss and slight change in surface shape

Level 3 gloss and surface shape change

Level 2 surface layer loss

Loss occurs below the level 1 surface layer

4. Softness

Referring to CN100400678 "Coating composition for leather, coating method and coating leather", the grades are as follows:

A very soft

Bsoft

C medium

Dhard

E very hard

5. Dust adsorption

A is not obvious

B general

C obviously

6. Slippery feeling

A dry and smooth

B smooth

C non-slip

7. 180° peeling damage

Refer to the provisions of 5.9 in GB/T8949-1995. The size of the sample is 100mm×25mm, the bonding length is 70mm, and the adhesive used is the primer of Example 1. After sizing, clamp it between two glass plates, apply a pressure of 5kg, bake at 120°C for 10min, take it out and let it cool. The speed of the stretching machine is 100-10mm/min until it breaks. Observe that failure occurs at the primer/surfacer interface (S1), the primer/substrate interface (S2) or the primer itself (B)

The specific formulations and performance test results of Examples 1-4 are listed in Table 1 below.

Table 1 embodiment 1～4 formula and test result

As can be seen from the results in Table 1, the different m values of the block silicone resin will have an impact on the softness and wear resistance of silicone synthetic leather. 4), the organosilicon synthetic leather is very soft, and when the m value is 500 (i.e. embodiment 2), the abrasion resistance of the organosilicon synthetic leather is the best. Therefore, the comprehensive performance of the organosilicon synthetic leather of embodiment 2 is the best.

Examples 5-8 are organic silicon synthetic leather with a three-layer structure and its preparation method. The formula and preparation method of the surface layer glue in Examples 5-8 are the same as those in Example 2, except that the bottom layer glue contains hydrogen. The proportion of cross-linking agent is different, respectively 3%, 5%, 7% and 9%, in order to investigate the effect of silicon hydrogen ratio on adhesion and wear resistance. The organic silicon synthetic leather of embodiment 5-8 has also been carried out performance test (testing method is identical with embodiment 1-4). The specific formulations and performance test results of Examples 5-8 are listed in Table 2.

The formula and test result of table 2 embodiment 5～8

The silicon-hydrogen ratio, that is, the ratio of the number of moles of hydrogen atoms in the hydrogen-containing crosslinking agent to the number of moles of vinyl groups in vinyl silicone oil, is an important factor affecting the vulcanization characteristics and bonding strength of silicone rubber. In the present invention, the Si-H group will also participate in other chemical reactions that promote adhesion, so even if the hydrogen-containing crosslinking agent of 3% (i.e. Example 5) (hydrogen content 0.5-0.7%), its silicon-hydrogen ratio is also low. It is already higher than the commonly used ratio of silicone rubber, such as 1.2:1, and the heat resistance and adhesion at this time are very good.

Examples 9 to 12 are organosilicon synthetic leathers with a three-layer structure and their preparation methods. The formulas and preparation methods of Examples 9 to 12 are the same as those in Example 2, the only difference being that the base rubber and vinyl-containing rubber in the bottom layer are the same as those in Example 2. The proportion of polydimethylsiloxane is different, but the formula of the top layer glue is the same, in order to investigate the effect of the ratio of base glue and vinyl-containing polydimethylsiloxane on the bottom glue. The organic silicon synthetic leather of embodiment 9-12 has also been carried out performance test (testing method is identical with embodiment 1-4). The specific formulations and performance test results of Examples 9-12 are listed in Table 3.

The formula and test result of table 3 embodiment 9～12

From the results in Table 3, it can be seen that the ratio of rubber base and vinyl-containing polydimethylsiloxane will significantly affect the abrasion resistance and 180° peeling damage of silicone synthetic leather. With the increase of vinyl-containing polydimethylsiloxane content and the decrease of base rubber content, the abrasion resistance of silicone synthetic leather decreases, and 180°peeling damage occurs more at the bottom rubber/substrate interface (S2) Or the primer itself (B).

The preparation methods of Comparative Examples 1-6 are the same as those of Example 2, and the formulations are slightly different from those of Example 2, in order to investigate the influence of minor adjustments of formulations on the properties of silicone synthetic leather. The performance test was also carried out on the silicone synthetic leather of Comparative Examples 1-6 (the test method was the same as that of Examples 1-4). The specific formulations and performance test results of Comparative Examples 1-6 are listed in Table 4.

Table 4 embodiment 2 and the proportioning parameter table and test result of comparative example _1-6

As can be seen from Table 4,

The bottom glue of comparative example 1 does not contain tackifier and accelerator, so that the adhesiveness of organic silicon synthetic leather is reduced, the peeling damage is large, and the abrasion resistance is not good;

The content of the Si-H-based crosslinking agent in the bottom glue of Comparative Example 2 is reduced, so that the adhesiveness of the organic silicon synthetic leather is reduced, the folding fastness, the abrasion resistance are poor, and the peeling damage is large;

The surface layer glue of Comparative Example 3 does not contain accelerator, which makes the surface layer material of organic silicon synthetic leather have poor mechanical strength and large peeling damage.

The organosilicon synthetic leather of comparative example 4 does not contain surface glue, so that its wear resistance, heat-resistant adhesion, dust absorption, and slippery feeling are all poor;

In comparative examples 5-6, the content of block-type silicone resin in the surface layer glue increased and the content of the base rubber decreased, which made the texture of the silicone synthetic leather worse;

The above results confirm the rationality and practical effect of the solution proposed by the present invention.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. a kind of organosilicon synthetic leather of three-layer structure, it is characterized in that, described organosilicon synthetic leather is bonded successively by base material, bottom glue and surface glue; Described base glue comprises the component of following mass percentage:

Described surface glue comprises the component of following mass percentage:

Wherein: the vinyl-containing polydimethylsiloxane is a polydimethylsiloxane in which at least two vinyl groups are directly connected to Si, and the vinyl groups are located at chain ends and/or side chains; The Si-H group-containing crosslinking agent is polydimethylsiloxane with at least 3 hydrogen atoms directly connected to Si, the hydrogen atoms are located at the chain ends and/or side chains, and the hydrogen atom content is 0.1 ~1.6%; the Si-H group-containing crosslinking agent is linear, branched, cyclic or a mixture thereof; The block-type silicone resin is obtained by polycondensation reaction of a hydrolyzed prepolymer of a silicone monomer mixture with a structure of R _n SiX _4-n and a linear polysiloxane with a structure of X(R ₂ SiO) _m X The copolymer; where n=0,1,2,3; m=100～1000; the molar ratio of R3SiX chain unit to SiX ₄ chain unit is 0.7～0.9, and the vinyl content is 1～10%; The platinum catalyst is chloroplatinic acid isopropanol solution, chloroplatinic acid tetrahydrofuran solution, chloroplatinic acid-divinyltetramethyldisiloxane complex, or chloroplatinic acid-1, 3, 5, 7-tetra Vinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane complex, the content of Pt atoms in the platinum catalyst is 100-500000ppm; The inhibitor is methyl butynyl alcohol, ethynyl cyclohexanol, alkyne-containing maleic acid or its derivatives, alkyne-containing fumaleic acid or its derivatives, polyvinylpolysiloxane, Pyridine, unsaturated amides, organic phosphines or phosphites; The filler is hydrophobic or hydrophilic silica, fumed silica, hydrophobic fumed silica, titanium dioxide, calcium carbonate, aluminosilicate, aluminum oxide, aluminum hydroxide, magnesium hydroxide or a mixture thereof; The tackifier is γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltriethoxysilane, 2-(3, 4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, or a combination thereof, or a compound or combination thereof Partial hydrolyzate; The accelerator is a metal chelate, titanate, zirconate, or carboxylate of Zn, Ba, Ca, Mn, or a mixture of the above compounds; The color paste is a pigment using vinyl polydimethylsiloxane as a dispersion medium; The organic solvent is C ₅ -C ₃₀ alkanes and/or aromatics, C ₅ -C ₃₀ ethers and/or esters, or a mixture of the above compounds, or octamethylcyclotetrasiloxane. 2. The organosilicon synthetic leather with three-layer structure according to claim 1, characterized in that, the component content in the bottom layer glue is: base glue 80%, vinyl-containing polydimethylsiloxane 5% , Containing 7% of Si-H-based cross-linking agent; the component content of the surface layer adhesive is: 30% of block-type silicone resin, 5% of Si-H-based cross-linking agent, and 50% of organic solvent. 3. The organosilicon synthetic leather with three-layer structure according to claim 1 or 2, characterized in that, the base rubber is fumed silica and vinyl silicone oil in a weight ratio of 20-40:60-80 It is obtained by mixing in a kneader, during which hexamethylsilazane, water and 0.1-3% small molecule hydroxyl silicone oil with a hydroxyl content of 3-15% are used to treat the silicon hydroxyl groups on the surface of fumed silica. 4. The organosilicon synthetic leather with three-layer structure according to claim 1 or 2, characterized in that, the hydrogen atoms of the Si-H-based crosslinking agent are located in the side chains, and the hydrogen atom content is 0.2 to 0.75 %. 5. the organosilicon synthetic leather of three-layer structure according to claim 1 or 2, is characterized in that, m=100 of linear polysiloxane X (R ₂ SiO) _m X in the block type organosilicon resin -800. 6. The organosilicon synthetic leather with three-layer structure according to claim 5, characterized in that, m=500-600 of linear polysiloxane X(R ₂ SiO) _m in the block type organosilicon resin . 7. The organosilicon synthetic leather with three-layer structure according to claim 1 or 2, characterized in that, the polydimethylsiloxane containing vinyl is α, ω-vinyl polydimethylsiloxane alkane with a viscosity of 2000-100000mPa.s; the platinum catalyst is a chloroplatinic acid-divinyltetramethyldisiloxane complex; the content of Pt atoms in the platinum catalyst is 2000-5000ppm; the inhibitor It is methyl butynol, ethynyl cyclohexanol, or tetramethyltetravinyl cyclotetrasiloxane; the accelerator is aluminum acetylacetonate, butoxy zirconium, isopropoxy zirconium, n-butyl titanate ester, isopropyl titanate, or tert-butyl titanate; the color paste is a pigment with α, ω-vinyl polydimethylsiloxane as a dispersion medium; the filler is hydrophobic fumed silica , the specific surface area of the filler is 150-400m ² /g. 8. The organosilicon synthetic leather with a three-layer structure according to claim 1 or 2, characterized in that the organic solvent is a C ₅ -C ₁₆ alkane or aromatic hydrocarbon, or cyclosiloxane. 9. The preparation method of the organosilicon synthetic leather of the three-layer structure described in any one of claims 1-8, is characterized in that, comprises the following steps: (1) Coat the surface layer glue on the release paper, the traveling speed is 3-30m/min, the baking temperature is 80-150℃, and the baking time is 1-10min; (2) Coat the bottom layer glue on the surface layer glue that has been cured, and combine it with the base material under the action of the pressure roller; the speed of travel is 3-30m/min, the baking temperature is 80-150°C, and the baking The time is 5-10 minutes; (3) peel off the release paper to obtain the organosilicon synthetic leather with the three-layer structure. 10. The preparation method of the organosilicon synthetic leather with three-layer structure according to claim 9, characterized in that, the baking temperature described in step (1) is 100 to 130° C., and the baking time is 3 to 5 minutes; The baking temperature in (2) is 100-130° C., and the baking time is 5-8 minutes.