Composition for artificial leather and preparation method of artificial leather

Abstract

The invention discloses a composition for artificial leather and a preparation method of the artificial leather. The composition for artificial leather comprises a hydrogenated styrene-butadiene copolymer; the hydrogenated styrene-butadiene copolymer is prepared from high-fluidity SEBS (styrene-ethylene-butadiene-styrene) and high-strength SEBS. The composition has excellent processability, can effectively reduce the calendaring temperature, is subjected to calendaring, foaming and other processes to obtain the artificial leather, has excellent folding resistance, wear resistance and low-temperature performance, can be used for automobile sofa leather, instep leather, luggage leather and other occasions, also has the advantage of recycling, and is worthy of popularization and application. The material can be effectively recycled in the fields of shoemaking, asphalt modification, sports mats and the like.

Description

Technical Field

[0001] The invention relates to a composition for artificial leather and a method for preparing artificial leather, belonging to the technical field of artificial leather materials and processing thereof. Background Art

[0002] Existing seats of cars, trains, furniture, etc. are all made of soft PVC, polyurethane artificial leather or natural leather. The production process of existing soft PVC leather and polyurethane leather requires the use of plasticizers, dimethylformamide, isocyanate monomers, etc. The VOC release in the production process is relatively large, requiring huge VOC treatment and air purification equipment. Artificial leather will also release VOCs for a long time during use. Soft PVC leather will also precipitate plasticizers or cause artificial leather to crack easily due to the precipitation of plasticizers. Polyurethane leather has poor water resistance and will break in 3 to 5 years. Artificial leather will produce a large amount of harmful substances when incinerated, such as dioxins, NO X wait.

[0003] As people's living standards improve, they have higher requirements for production and furniture environment. They hope that the production, use and disposal of polymer materials will be environmentally friendly throughout their life cycle, release less VOC, be easy to handle or not produce harmful substances after disposal, and be easily decomposed by bacteria. Therefore, the artificial leather industry hopes that new materials can solve the above problems.

[0004] Chinese patent CN114426754A discloses the use of vulcanization cross-linking to improve the comprehensive performance of SEBS artificial leather products. The composition has poor processing fluidity, high calendering temperature, and is prone to over-cross-linking during cross-linking, resulting in the leather product becoming brittle, having a poor feel, and reduced wear resistance. Summary of the invention

[0005] In view of the defects of the prior art, the first object of the present invention is to provide a composition for artificial leather, which is environmentally friendly, recyclable, and has good processing performance, and the prepared artificial leather has excellent comprehensive properties, such as good bonding performance, good wear resistance and good folding resistance.

[0006] The second object of the present invention is to provide a method for preparing artificial leather, which is simple, has mild and controllable conditions, and is easy to realize industrial production.

[0007] In order to achieve the above technical objectives, a composition for artificial leather is characterized by comprising a hydrogenated styrene-butadiene copolymer;

[0008] The hydrogenated styrene-butadiene copolymer consists of high-fluidity SEBS and high-strength SEBS;

[0009] The high fluidity SEBS has the following structure:

[0010]

[0011] Among them, n1=42~52; n2=42~52; m1=166~285; m2=433~611;

[0012] The high-strength SEBS has the following structure:

[0013]

[0014] Among them, x=1~10; y+z=1~13; z / y≦0.3; n=500~2000.

[0015] The molecular weight of the high-fluidity SEBS in the hydrogenated styrene-butadiene copolymer of the present invention is relatively low, and the proportion of the side alkyl chain structural unit is more than 65%, which can be well compatible with other low-molecular-weight saturated resins, has excellent processing performance, and the hardness of the polymer is low. By adjusting its dosage, the final leather product has excellent softness. The high-strength SEBS basically belongs to the full random SEBS containing microblock structure. On the one hand, this structure gives it good compatibility with polar surface coating agents. On the other hand, the z / y in the polymer is less than 0.3, and a large amount of y exists in the polymer, so it embodies the characteristics of high mechanical strength similar to polyethylene.

[0016] The artificial leather composition of the present invention mainly adopts high-fluidity SEBS and high-strength SEBS in combination. The high-fluidity SEBS can improve the processability of the composition. Compared with the existing PVC artificial leather, the calendering temperature in the calendering molding process is reduced by about 20°C, and the high-strength SEBS can improve the melt strength of the composition. The composition still has good mechanical properties under high-ratio (0.25-0.35) foaming conditions. In particular, the combination of the two can give the artificial leather good comprehensive mechanical properties. The Martindale abrasion resistance number is greater than 100,000 times, the low-temperature (-20°C) folding resistance number is greater than 50,000 times, and the room-temperature folding resistance number is greater than 100,000 times.

[0017] As a preferred solution, the mass ratio of the high-flowability SEBS to the high-strength SEBS is 5:(1-3); the most preferred mass ratio of the high-flowability SEBS to the high-strength SEBS is 5:(1.5-2.5). When the ratio is much lower than 5:2, the hardness of the composition is high and the feel of the leather product is poor, while when it is much higher than 5:2, the mechanical strength of the composition is insufficient and good physical properties cannot be provided.

[0018] As a preferred solution, the composition for artificial leather comprises hydrogenated styrene-butadiene copolymer, polar resin, tackifier, flame retardant and wear-resisting agent. Polar resin, tackifier and wear-resisting agent are all introduced as auxiliary raw materials, tackifier resin can improve the adhesion between artificial leather and base cloth, polar resin can solve the compatibility between non-polar SEBS and polar surface coating agent, thereby obtaining a good surface coating effect, and wear-resisting agent can improve its wear resistance.

[0019] As a preferred solution, the composition for artificial leather comprises the following components in mass percentage: 70-80% hydrogenated styrene-butadiene copolymer; 5%-15% polar resin; 5%-10% tackifier; 1%-5% anti-wear agent. When the proportion of hydrogenated styrene-butadiene copolymer is too low, the leather product has a poor touch, and when the proportion of hydrogenated styrene-butadiene copolymer is too high, the content of other functional components is low, and good surface coating and bonding effect with the base fabric cannot be achieved.

[0020] As a more preferred solution, the artificial leather composition is most preferably composed of the following components in percentage by mass: 78% hydrogenated styrene-butadiene copolymer; 10% polar resin; 10% tackifier; and 2% anti-wear agent.

[0021] As a preferred solution, the polar resin includes at least one of polyacrylate and polyurethane.

[0022] As a preferred solution, the tackifier includes hydrogenated C5 resin.

[0023] As a preferred solution, the wear-resistant agent includes silicone resin.

[0024] The preferred polar resin, tackifier and anti-wear agent have good compatibility with the hydrogenated styrene-butadiene copolymer and can be fully blended and dispersed with the hydrogenated styrene-butadiene copolymer to exert their effects.

[0025] As a preferred solution, the artificial leather composition may further include conventional artificial leather additives such as flame retardants, which are added in appropriate amounts as required.

[0026] The invention also provides a method for preparing artificial leather, which comprises the steps of blending and extruding the composition for artificial leather to obtain granules; and calendering and foaming the granules to obtain the artificial leather.

[0027] As a preferred solution, the extrusion molding adopts a co-rotating twin-screw extruder, the screw speed is 120-240rpm, the extrusion cavity of the co-rotating twin-screw extruder is divided into 6 temperature zones from the feeding section to the die, and the temperatures of the feeding section, the temperature zones of the extrusion cavity and the die are: 95-105°C for the feeding section, 135-145°C for the first zone, 170-180°C for the second zone, 175-185°C for the third zone, 175-185°C for the fourth zone, 175-185°C for the fifth zone, and 155-165°C for the die. Extrusion is carried out under the preferred temperature conditions, and the surface of the obtained pellets is smooth and it is not easy to produce polymer aging and chain breaking due to excessive temperature.

[0028] As a preferred solution, during the calendering process, the temperature is 120-150°C.

[0029] As a preferred solution, azodicarbonamide is used as a foaming agent in the foaming process, and the foaming temperature is 170-180°C.

[0030] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0031] The artificial leather composition of the present invention adopts high-fluidity SEBS to improve the processability of the composition. The artificial leather is prepared by a calendering process, and the calendering temperature is about 20° C. lower than that of the existing PVC artificial leather, which is beneficial to energy saving and reducing production costs. At the same time, the high-strength SEBS can improve the melt strength of the composition, and still has good mechanical properties under high-ratio (0.25-0.35) foaming conditions; in addition, functional auxiliary materials can be further introduced, such as the introduction of tackifying resin to improve the adhesion between the artificial leather and the base cloth, the introduction of polar resin solves the compatibility of non-polar polymers such as SEBS and polar surface coating agents, thereby obtaining a good surface coating effect, and the wear-resistant agent can improve its wear resistance.

[0032] The artificial leather prepared by the artificial leather composition of the present invention has excellent comprehensive performance, and has better low-temperature performance than the existing PVC artificial leather, and the lowest use temperature can reach about -50°C. Since SEBS is a non-polar polymer, its hydrolysis resistance is greatly improved compared with PU leather. The artificial leather composition can be used for the middle foaming layer of the artificial leather, with a foaming ratio of about 0.3, and has an excellent bonding effect with the base fabric layer, and can also be used for the surface layer of the artificial leather, and has good compatibility with the surface coating agent. The prepared artificial leather has a Martindale wear resistance of more than 100,000 times, a low temperature (-20°C) folding resistance of more than 50,000 times, and a room temperature folding resistance of more than 100,000 times.

[0033] Each component of the artificial leather composition of the present invention is safe and environmentally friendly, with VOC lower than 10 ppm, and also has the advantage of recycling, and can be effectively recycled in the fields of shoemaking, asphalt modification, sports mats, etc.

[0034] The preparation method of the artificial leather of the invention is simple, the conditions are mild and controllable, and industrial production can be easily realized. DETAILED DESCRIPTION

[0035] The following specific examples are intended to further illustrate the present invention rather than to limit the scope of protection of the claims.

[0036] The raw materials involved in the following specific examples are all conventional commercially available products.

[0037] High-flow SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-505, number average molecular weight 47820, bound styrene mass content 20%, 1,2-structure mass content in butadiene units before hydrogenation 67.3%);

[0038] High-strength SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-520, number average molecular weight 72365, bound styrene mass content 20%, 1,2-structure mass content in butadiene units before hydrogenation 16.9%);

[0039] Acrylate resin (Japan Kuraray, model LA2250);

[0040] Hydrogenated C5 resin (Zhejiang Henghe Petrochemical Co., Ltd., H5-1000);

[0041] Silicone resin (Guangzhou Haochangyue, SA-400).

[0042] Example 1

[0043] 50 parts of high-flowability SEBS, 25 parts of high-strength SEBS, 10 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 5 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0044] The twin-screw extrusion process parameters are set as follows:

[0045] Feeding section Zone 1 Zone 2 Zone 3 District 4 District 5 District 6 Machine head 80℃ 130℃ 170℃ 170℃ 170℃ 170℃ 170℃ 160℃

[0046] The calendering temperature is 130°C;

[0047] The foaming temperature is 170°C and the foaming time is 15 minutes;

[0048] Martindale abrasion test standard: ASTM D 4966;

[0049] Folding resistance test standard: QB / T2714-2005.

[0050] Example 2

[0051] 50 parts of high-flowability SEBS, 25 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed to form leather, and the performance was tested. The process parameters and conditions are shown in Example 1.

[0052] Example 3

[0053] 45 parts of high-flowability SEBS, 30 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0054] See Example 1 for process parameter conditions.

[0055] Example 4

[0056] 40 parts of high-flowability SEBS, 35 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0057] See Example 1 for process parameter conditions.

[0058] Example 5

[0059] 55 parts of high-flowability SEBS, 20 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0060] See Example 1 for process parameter conditions.

[0061] Example 6

[0062] 60 parts of high-flowability SEBS, 15 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0063] See Example 1 for process parameter conditions.

[0064] Example 7

[0065] 50 parts of high-flowability SEBS, 25 parts of high-strength SEBS, 15 parts of acrylic resin, 5 parts of hydrogenated carbon pentane resin and 5 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0066] See Example 1 for process parameter conditions.

[0067] Example 8

[0068] 50 parts of high-flowability SEBS, 30 parts of high-strength SEBS, 10 parts of acrylic resin, 5 parts of hydrogenated carbon pentane resin and 5 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0069] See Example 1 for process parameter conditions.

[0070] Example 9

[0071] 50 parts of high-flowability SEBS, 25 parts of high-strength SEBS, 13 parts of polyurethane, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0072] See Example 1 for process parameter conditions.

[0073] Example 10

[0074] 50 parts of high-flowability SEBS, 25 parts of high-strength SEBS, 15 parts of polyurethane, 5 parts of hydrogenated carbon pentane resin and 5 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and the performance was tested.

[0075] See Example 1 for process parameter conditions.

[0076] Comparative Example 1

[0077] 30 parts of commercially available PVC (Inner Mongolia Junzheng, model SG-5), 35 parts of calcium powder and 35 parts of dioctyl phthalate were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and the performance was tested.

[0078] See Example 1 for process parameter conditions.

[0079] Comparative Example 2

[0080] 50 parts of commercially available SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-502), 25 parts of No. 26 white oil, 10 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 5 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and the performance was tested.

[0081] See Example 1 for process parameter conditions.

[0082] Comparative Example 3

[0083] 50 parts of commercially available SEBS (Sinopec Baling Petrochemical Co., Ltd., model YH-502), 25 parts of No. 26 white oil, 10 parts of polypropylene resin, 10 parts of hydrogenated carbon pentane resin and 5 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and the performance was tested.

[0084] See Example 1 for process parameter conditions.

[0085] Comparative Example 4

[0086] 70 parts of high-flowability SEBS, 5 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0087] See Example 1 for process parameter conditions.

[0088] Comparative Example 5

[0089] 35 parts of high-flowability SEBS, 40 parts of high-strength SEBS, 13 parts of acrylic resin, 10 parts of hydrogenated carbon pentane resin and 2 parts of silicone resin were mixed uniformly in a high-speed mixer by mass, and then extruded and granulated in a twin-screw extruder to obtain a composition, which was calendered and foamed into leather, and its performance was tested.

[0090] See Example 1 for process parameter conditions.

[0091] The main performance test results of the above embodiments and comparative examples are shown in the following table:

[0092]

[0093]

Claims

1. A composition for artificial leather, characterized in that: Contains hydrogenated styrene-butadiene copolymer; The hydrogenated styrene-butadiene copolymer consists of high-fluidity SEBS and high-strength SEBS; The high fluidity SEBS has the following structure: in, n1＝42～52； n2＝42～52； m1＝166～285； m2＝433～611； The high-strength SEBS has the following structure: in, x＝1～10； y+z=1-13; z / y≦0.3; n＝500～2000。 2. The composition for artificial leather according to claim 1, characterized in that: The mass ratio of the high-fluidity SEBS to the high-strength SEBS is 5:(1-3).

3. The composition for artificial leather according to claim 1 or 2, characterized in that: The composition for artificial leather comprises a hydrogenated styrene-butadiene copolymer, a polar resin, a tackifier and an anti-wear agent.

4. The composition for artificial leather according to claim 3, characterized in that: The composition for artificial leather comprises the following components in percentage by weight: Hydrogenated styrene-butadiene copolymer 70-80%; Polar resin 5% to 15%; Thickener 5% to 10%; Wear-resistant agent 1%~5%.

5. The composition for artificial leather according to claim 4, characterized in that: The polar resin includes at least one of polyacrylate and polyurethane.

6. The composition for artificial leather according to claim 4, characterized in that: The tackifier includes hydrogenated carbon pentane resin.

7. The composition for artificial leather according to claim 4, characterized in that: The wear-resistant agent includes silicone resin.

8. A method for preparing artificial leather, characterized in that: The composition for artificial leather according to any one of claims 1 to 7 is blended and extruded to obtain pellets; the pellets are calendered and foamed to obtain the obtained product.

9. The method for preparing artificial leather according to claim 8, characterized in that: The extrusion molding adopts a co-rotating twin-screw extruder with a screw speed of 120-240 rpm. The extrusion cavity of the co-rotating twin-screw extruder is divided into 6 temperature zones from the feeding section to the die. The temperatures of the feeding section, each temperature zone of the extrusion cavity and the die are: 95-105°C for the feeding section, 135-145°C for the first zone, 170-180°C for the second zone, 175-185°C for the third zone, 175-185°C for the fourth zone, 175-185°C for the fifth zone, and 155-165°C for the die.

10. The method for preparing artificial leather according to claim 8, characterized in that: During the calendering process, the temperature is 120-150°C.

11. The method for preparing artificial leather according to claim 8, characterized in that: In the foaming process, azodicarbonamide is used as a foaming agent, and the foaming temperature is 170-180°C.

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