Light-transmitting TPO composition and light-transmitting TPO leather

Abstract

The invention relates to a light-transmitting TPO (thermoplastic polyolefin) composition which comprises 15-40 parts by weight of allyl elastomer, 10-40 parts by weight of polyolefin elastomer, 25-45 parts by weight of thermoplastic vulcanized rubber and 1-10 parts by weight of polypropylene random copolymer, totaling 100 parts by weight. The invention further relates to light-transmitting TPO leather which comprises a TPO skin made of the light-transmitting TPO composition. According to the TPO leather, the light transmittance can be improved, and the soft hand feeling can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a light-transmitting TPO composition and a corresponding light-transmitting TPO leather, especially applied to automotive interior. BACKGROUND

[0002] With the development of intelligent and electric vehicles, intelligent light systems are increasingly applied to automotive interiors. Consumers have dual requirements of decorative effect and soft touch for automotive interiors.

[0003] The existing automotive interior products on the market usually use light-transmitting hard plastic, polyvinyl chloride (PVC), and thermoplastic polyolefin elastomer (TPO) to achieve light effects. These products have different advantages and disadvantages. Among them, light-transmitting hard plastic is low in cost, but too hard in texture and not soft, which is not suitable for large-area use in automotive interiors; PVC is soft in hand feeling, but poor in light resistance, heat resistance, and weather resistance, and low in light transmission rate, resulting in unclear displayed patterns; TPO is good in light resistance, heat resistance, and weather resistance, but hard in hand feeling.

[0004] Therefore, the present application aims to develop a light-transmitting TPO material to solve at least one of the above technical problems. SUMMARY

[0005] The present application aims to provide a light-transmitting TPO composition and a corresponding light-transmitting TPO leather, which can improve light transmission and hand feeling.

[0006] To achieve the above technical purposes, the present application provides a light-transmitting TPO composition, which comprises 15 to 40 parts by weight of propylene-based elastomer (PBE), 10 to 40 parts by weight of polyolefin elastomer (POE), 25 to 45 parts by weight of thermoplastic vulcanized rubber (TPV), and 1 to 10 parts by weight of random copolymerized polypropylene (r-PP), totaling 100 parts by weight.

[0007] The propylene-based elastomer (PBE) is a propylene-ethylene random copolymer mainly composed of propylene and supplemented by ethylene. In principle, it can also contain other alpha olefins, such as butene, 4-methylpentene, nonene, octene, hexene, etc. Compared with traditional TPO formulations, the addition of PBE improves the softness, toughness, transparency, processability, and hand feeling of the material. When the content of PBE is too low, below 15 parts by weight, the light transmission and mechanical processability will decrease; when the content of PBE is too high, above 40 parts by weight, on the one hand, the flowability is too large, which will flow out of the extruder, which is not conducive to processing; on the other hand, as the PBE content increases, the POE and TPV contents will decrease accordingly, resulting in a decrease in low-temperature and high-temperature performance.

[0008] Preferably, the ethylene content in the propylene-based elastomer is 9 to 16 wt%. The content of ethylene monomer has a key influence on the performance. When the ethylene content is too high, higher than 16 wt%, it will cause too much flowability, and the extrusion is not easy to shape; when the ethylene content is too low, lower than 9 wt%, it will cause the material to be too hard, and the softness is poor. The ethylene content of 9 to 16 wt% defined in the present application can cause high light transmittance and density suitable for the skin, while ensuring proper processability and hardness.

[0009] Preferably, the density of the propylene-based elastomer is 0.80-0.95 g / cm 3 . The density in this range can be consistent with the density of the TPO skin to meet better compatibility. If the density is too low, it will affect the performance of the TPO skin; if the density is too high, it does not meet the lightweight, and also affects the performance of the TPO skin.

[0010] The polyolefin elastomer (POE) is a copolymer of ethylene and alpha olefin, preferably ethylene-octene copolymer or ethylene-butene copolymer. POE helps to improve flexibility.

[0011] Thermoplastic vulcanizate (TPV) also helps to improve flexibility.

[0012] Preferably, the hardness of the polyolefin elastomer is 60-80A, and the hardness of the thermoplastic vulcanizate is 55-85A, measured according to ISO 868 under the condition of 10s. The lower hardness in this range is beneficial to the softness of the overall material.

[0013] It is also preferable that the melt flow rate (MFR) of the polyolefin elastomer is 0.5-15 g / 10 min, and the melt flow rate (MFR) of the thermoplastic vulcanizate is 0.5-10 g / 10 min, measured according to ASTM D1238 under the condition of 230℃, 2.16 kg.

[0014] The addition of r-PP improves the compatibility of each component relative to the traditional TPO formula, so that the mechanical properties and transparency of the material are improved. When the content of r-PP is too high or too low, it will cause the light transmittance to decrease, and when the content of r-PP is too high, the softness of the material will also be poor.

[0015] Preferably, the composition contains 2 to 6 parts by weight of random copolymerized polypropylene.

[0016] Based on 100 parts by weight of the total amount of propylene-based elastomer, polyolefin elastomer, thermoplastic vulcanizate and random copolymerized polypropylene, the light transmittance TPO composition according to the present application can additionally contain 1 to 5 parts by weight of an auxiliary. The auxiliary includes stabilizers and nucleating agents.

[0017] Preferably, based on 100 parts by weight of the total amount of the propylene-based elastomer, the polyolefin elastomer, the thermoplastic vulcanizate and the random copolymer polypropylene, the composition further comprises 0.1 to 1 parts by weight of a nucleating agent. The addition of the nucleating agent helps to adjust the crystallinity, thereby improving the light transmittance. If the content of the nucleating agent is too low or too high, the light transmittance will be poor.

[0018] Preferably, the nucleating agent is an alpha crystal nucleating agent, more preferably an alpha crystal organic nucleating agent.

[0019] In addition, based on 100 parts by weight of the total amount of the propylene-based elastomer, the polyolefin elastomer, the thermoplastic vulcanizate and the random copolymer polypropylene, the composition further preferably comprises 0.5 to 3 parts by weight of a stabilizer, preferably a light stabilizer, more preferably a hindered amine light stabilizer.

[0020] Based on 100 parts by weight of the total amount of the propylene-based elastomer, the polyolefin elastomer, the thermoplastic vulcanizate and the random copolymer polypropylene, the light-transmitting TPO composition according to the present application can additionally comprise 0 to 3 parts by weight of a color master. The color master can be selected from one or several of organic pigment color masters (such as phthalocyanine blue, phthalocyanine green, PY110 yellow, PY138 yellow, PR170 red, PR122 red, PV19 violet) and inorganic pigment color masters (such as carbon black, titanium white, iron red, titanium chromium yellow, titanium nickel yellow, zinc iron yellow, ultramarine blue).

[0021] To achieve the above technical purposes, the present application further provides a light-transmitting TPO leather comprising a TPO skin made of the light-transmitting TPO composition according to the present application.

[0022] According to the present application, the TPO skin is preferably extruded from the light-transmitting TPO composition of the present application using a twin-screw extruder. For this purpose, conventional extrusion processes known to those skilled in the art can be used.

[0023] Preferably, a transparent paint layer is applied on the front and back surfaces of the TPO skin, respectively. Thereby, a top paint layer and a back paint layer are formed. The paint layer can be applied on the surface by using conventional paints known to those skilled in the art, preferably using a transparent water-based polyurethane resin. By printing the paint layer on the surface of the TPO skin, the gloss, the hand feeling and the light resistance, heat resistance, dirt resistance, wear resistance and scratch resistance of the surface of the TPO leather can be advantageously improved.

[0024] It is also preferable to emboss patterns on the TPO skin, so that the final TPO skin has the same appearance patterns and hand feeling as the real leather.

[0025] The TPO leather obtained according to the present application can be applied to automobile seats, armrests, door panels, instrument panels, floors and other parts by processes such as vacuum forming.

[0026] The aforementioned technical features and related technical effects of the light-transmitting TPO composition also apply to the light-transmitting TPO leather, which will not be described again here.

[0027] The advantages of the present application are:

[0028] By adding PBE, r-PP and nucleating agent in the TPO composition, and limiting the hardness of POE and TPV, the light transmission and hand feeling of the generated TPO skin are simultaneously improved. For example, in the case of a 0.5mm skin thickness, the light transmission rate measured according to GB / T 2410-2008 is

[0029] ≥9.5%, and the Shore hardness measured according to ISO 868 at 10s reading is ≤80A. The TPO leather obtained according to the present application, when covered on a patterned light source and irradiated, can clearly show the pattern due to the improved light transmission compared to conventional TPO leather. The TPO leather obtained according to the present application also has good mechanical properties. DETAILED DESCRIPTION

[0030] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the present application will be described in detail below in conjunction with examples. Obviously, the described examples are part of the examples of the present application, rather than all examples. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] Production steps of light-transmitting TPO automotive interior leather:

[0032] Step 1: extruding the skin: the TPO raw materials are added into a double screw extruder according to the formula (extrusion temperature 200℃, screw rotation speed 220rpm), and the TPO skin is extruded and calendered, with a thickness of 0.5mm.

[0033] Step 2: printing the topcoat: transparent water-based polyurethane paint is applied on the front side of the TPO skin to achieve the desired surface performance.

[0034] Step 3: printing the backcoat: transparent water-based polyurethane paint is applied on the back side of the TPO skin for easy processing by the customer.

[0035] Step 4: embossing: the front side of the TPO skin is embossed at high temperature to make the final TPO skin have the same appearance pattern and hand feeling as real leather.

[0036] Step 5: cutting: the finished product is cut according to the customer's requirements.

[0037] Next, according to the above production steps, TPO leather samples of Examples 1-9 are manufactured according to the TPO formula in Table 1.

[0038] Table 1 (content of each component in TPO in parts by weight)

[0039] Ethylene content in PBE PBE POE TPV r-PP Stabilizer Nucleating agent Color masterbatch Example 1 9 wt% 15 40 44 1 2 0.1 1 Example 2 9 wt% 15 40 43 2 2 0.3 1 Example 3 9 wt% 15 35 40 10 2 1 1 Example 4 11 wt% 30 39 30 1 2 0.1 1 Example 5 11 wt% 30 30 35 5 2 0.3 1 Example 6 11 wt% 30 35 25 10 2 1 1 Example 7 16 wt% 40 34 25 1 2 0.1 1 Example 8 16 wt% 40 24 30 6 2 0.3 1 Example 9 16 wt% 40 10 40 10 2 1 1

[0040] In addition, TPO leather samples of Comparative Examples 1-8 were produced according to the above production steps according to the TPO formulations in Table 2.

[0041] Table 2 (content of each component in TPO in parts by weight)

[0042] Ethylene content in PBE PBE POE TPV rPP Stabilizer Nucleating agent Color masterbatch Comparative Example 1 4 wt% 30 30 35 5 2 0.3 1 Comparative Example 2 11 wt% 30 30 35 5 2 0 1 Comparative Example 3 11 wt% 30 30 35 5 2 1.5 1 Comparative Example 4 11 wt% 10 40 45 5 2 0.3 1 Comparative Example 5 11 wt% 60 20 15 5 2 0.3 1 Comparative Example 6 11 wt% 30 25 30 15 2 0.3 1 Comparative Example 7 11 wt% 30 30 35 5 2 0.3 1 Comparative Example 8 11 wt% 30 30 35 5 2 0.3 1

[0043] wherein,

[0044] - The PBE used in Examples 1-9 and Comparative Examples 1-8 were all random copolymers of propylene and ethylene, without other alpha olefins.

[0045] - The POE in Examples 1-9 had a hardness of 70A and a MFR of 0.5 g / 10 min; the TPV had a hardness of 59A and a MFR of 7 g / 10 min. Hardness was measured according to ISO 868 at 10 s, and melt flow rate MFR was measured according to ASTM D1238 at 230°C, 2.16 kg.

[0046] - The POE and TPV in Comparative Examples 1-6 were selected to be the same as in Examples 1-9.

[0047] - The POE in Comparative Example 7 had a hardness of 46A and a MFR of 3.6 g / 10 min; the TPV had a hardness of 50A and a MFR of 5 g / 10 min. Hardness was measured according to ISO 868 at 10 s, and melt flow rate MFR was measured according to ASTM D1238 at 230°C, 2.16 kg.

[0048] - The POE in Comparative Example 8 had a hardness of 89A and a MFR of 2.5 g / 10 min; the TPV had a hardness of 90A and a MFR of 15 g / 10 min. Hardness was measured according to ISO 868 at 10 s, and melt flow rate MFR was measured according to ASTM D1238 at 230°C, 2.16 kg.

[0049] - The nucleating agent used in Examples 1-9 and Comparative Examples 1-8 was all an alpha crystalline organic nucleating agent.

[0050] - The r-PP, stabilizers, and color masterbatch used in Examples 1-9 and Comparative Examples 1-8 were the same.

[0051] The TPO leather samples obtained in Examples 1-9 and Comparative Examples 1-8 were tested for light transmittance (GB / T 2410-2008), hardness (ISO 868, 10s), tensile strength in warp direction (ISO 527-3 Type 5), tensile strength in weft direction (ISO 527-3 Type 5), elongation at break in warp direction (ISO 527-3 Type 5) and elongation at break in weft direction (ISO 527-3 Type 5), respectively, and the extrusion state of the skin during extrusion was observed visually. The test and observation results are listed in Table 3.

[0052] Table 3: Test and observation results

[0053]

[0054] In order to more clearly show the comparison of the results, the performance values that do not meet the standard range are underlined in Table 3.

[0055] According to the results in Table 3, it can be seen that the leathers of Examples 1-9 obtained from the TPO formulations according to the present application have high light transmittance and low hardness, and both the light transmittance and the hand feel are satisfactory, while having good mechanical properties. In Comparative Example 1, the low ethylene content in the PBE leads to poor light transmittance and hard hand feel of the leather. In Comparative Example 2, the absence of nucleating agent leads to poor light transmittance of the leather. In Comparative Example 3, the excessive content of nucleating agent leads to poor light transmittance and mechanical strength of the leather. In Comparative Example 4, the low content of PBE leads to poor light transmittance and mechanical strength of the leather. In Comparative Example 5, the excessive content of PBE leads to excessive flowability, and the leather cannot be extruded normally. In Comparative Example 6, the excessive content of r-PP leads to poor light transmittance and mechanical strength of the leather, and the hand feel is hard. In Comparative Example 7, the low hardness of POE and TPV leads to excessive flowability, and the leather cannot be extruded normally. In Comparative Example 8, the high hardness of POE and TPV leads to large hardness and poor hand feel.

[0056] It can be understood that the above embodiments are only exemplary embodiments adopted for illustrating the principles of the present application, and the present application is not limited thereto. Various modifications and improvements can be made by those of ordinary skill in the art without departing from the spirit and essence of the present application, and these modifications and improvements are also considered to be within the protection scope of the present application.

Claims

1. A light-transmitting TPO composition, characterized in that, comprising 15 to 40 parts by weight of a propylene-based elastomer, 10 to 40 parts by weight of a polyolefin elastomer, 25 to 45 parts by weight of a thermoplastic vulcanizate, and 1 to 10 parts by weight of a random copolypropylene, the total being 100 parts by weight.

2. The light-transmitting TPO composition of claim 1, wherein, The propylene-based elastomer is a propylene-ethylene random copolymer having an ethylene content of 9 to 16% by weight.

3. The light-transmitting TPO composition according to claim 1 or 2, characterized in that, The propylene-based elastomer has a density of 0.80 to 0.95 g / cm 3 .

4. The light-transmitting TPO composition of claim 1 or 2, wherein, The polyolefin elastomer has a hardness of 60-80A and the thermoplastic vulcanizate has a hardness of 55-85A, measured according to ISO 868 at 10 s.

5. The light-transmitting TPO composition of claim 1 or 2, wherein, The polyolefin elastomer has a melt flow rate of 0.5-15 g / 10 min and the thermoplastic vulcanizate has a melt flow rate of 0.5-10 g / 10 min, measured according to ASTM D1238 at 230°C, 2.16 kg.

6. The light-transmitting TPO composition of claim 1 or 2, wherein, The composition comprises 2 to 6 parts by weight of a random copolypropylene.

7. The light-transmitting TPO composition of claim 1 or 2, wherein, The composition further comprises 0.1 to 1 parts by weight of a nucleating agent, based on 100 parts by weight of the total of the propylene-based elastomer, the polyolefin elastomer, the thermoplastic vulcanizate, and the random copolypropylene.

8. The light-transmitting TPO composition of claim 7, wherein, The nucleating agent is an alpha crystalline organic nucleating agent.

9. A light-transmitting TPO leather, characterized by A TPO skin made of the light-transmitting TPO composition according to any one of claims 1 to 8.

10. The light-transmitting TPO leather according to claim 9, characterized in that, The TPO skin is coated with a transparent paint layer on both the front side and the back side, respectively.

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