Nylon-overmolded TPE composite material, preparation method therefor and use thereof

Abstract

Disclosed are a nylon-overmolded TPE composite material, a preparation method therefor and a use thereof. The nylon-overmolded TPE composite material of the present invention comprises: a hydrogenated styrene elastomer, mineral oil, polypropylene, polycaprolactam, a thermoplastic polyamide elastomer, maleic anhydride grafted polypropylene, a maleic anhydride grafted olefin copolymer elastomer, a maleic anhydride grafted hydrogenated styrene elastomer, a filler, and an additive. The nylon-overmolded TPE composite material combines polycaprolactam and a thermoplastic polyamide elastomer, along with other components; the use of the polycaprolactam enhances the strength of the composite material and improves the overmolding performance; moreover, the thermoplastic polyamide elastomer not only increases the elastomer content to improve the appearance of the composite material, but also can improve the overall compatibility of the polycaprolactam with the composite material; thus, a nylon-overmolded TPE composite material having high binding force, excellent mechanical properties and good appearance is obtained.

Description

A nylon-coated TPE composite material and its preparation method and application Technical Field

[0001] The present invention relates to the technical field of polymer compound compositions, and more specifically, to a nylon-encapsulated TPE composite material, a preparation method thereof, and applications thereof. Background Art

[0002] Thermoplastic elastomer (TPE) is a polymer composite material that has both the processing properties of thermoplastics and the physical properties of vulcanized rubber. It is widely used in the fields of electronics, communications, daily necessities, and automobiles. Among them, an important application of TPE is as a coating material (encapsulation), which is to encapsulate TPE soft rubber material on the surface of other materials, and use its good anti-slip properties and good elastic touch to improve the touch feel of the product and enhance the grip. At present, the coated materials mainly include general plastics (PP, GPPS, HIPS, ABS) and engineering plastics (PC, PC / ABS, PA, POM). Among them, nylon (PA) is a highly polar polymer material, while conventional TPE is mainly composed of SEBS, white oil, PP, POE and other components. It is a non-polar material, resulting in poor adhesion between it and nylon.

[0003] To solve the above problems, the prior art discloses a new TPE nylon encapsulation material and a preparation method thereof. The TPE nylon encapsulation material includes: styrene elastomer, white oil, maleic anhydride grafted polystyrene elastomer, maleic anhydride grafted polyethylene, polypropylene, calcium carbonate and a stabilizer. Maleic anhydride grafted polystyrene elastomer is used to improve the bonding strength between the TPE encapsulation and nylon, thereby improving the bonding performance between TPE and nylon. However, styrene polymers (PS, HIPS, AS, ABS) are prone to cause cohesive failure of the material, thereby reducing the tensile properties of the TPE nylon encapsulation material.

[0004] For example, the prior art also discloses a TPE nylon encapsulated pellet with high fluidity and high adhesion, which includes styrene elastomer, white oil, maleic anhydride grafted polystyrene elastomer, maleic anhydride grafted polyethylene, maleic anhydride grafted POE, polypropylene and calcium carbonate. By introducing maleic anhydride grafted POE, the adhesion and compatibility between polar materials and non-polar materials are improved, thereby increasing the bonding strength between TPE and nylon; however, maleic anhydride grafted POE or maleic anhydride grafted polyethylene has low compatibility with polypropylene and maleic acid styrene elastomer, resulting in poor mechanical properties and appearance properties of the PE nylon encapsulated material. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects and shortcomings of existing TPE nylon encapsulated materials that are difficult to have high adhesion, excellent mechanical properties and good appearance, and to provide a nylon encapsulated TPE composite material.

[0006] Another object of the present invention is to provide a method for preparing a nylon-encapsulated TPE composite material.

[0007] Another object of the present invention is to provide an application of the above-mentioned dragon-coated TPE composite material in the coating of power tool handles, game controllers and automotive parts.

[0008] Another object of the present invention is to provide a rubber-coated nylon product.

[0009] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0010] The present invention protects a nylon-coated TPE composite material, which comprises the following components in parts by weight:

[0011] 10-30 parts of hydrogenated styrene elastomer, 20-60 parts of mineral oil, 5-20 parts of polypropylene, 5-15 parts of polycaprolactam, 5-15 parts of thermoplastic polyamide elastomer, 1-20 parts of maleic anhydride grafted polypropylene, 1-20 parts of maleic anhydride grafted olefin copolymer elastomer, 1-20 parts of maleic anhydride grafted hydrogenated styrene elastomer, 0-50 parts of filler, and 0-2 parts of additives.

[0012] The nylon encapsulated TPE composite material of the present invention combines polypropylene, maleic anhydride grafted polypropylene and polycaprolactam, and is used in combination with thermoplastic polyamide elastomer, hydrogenated styrene elastomer and maleic anhydride grafted hydrogenated styrene elastomer, which can not only effectively improve the strength and toughness of the composite material, but also significantly improve its encapsulation performance.

[0013] The addition of thermoplastic polyamide elastomers increases the elastomer content, improving the feel and appearance of the composite. Furthermore, the amide groups in the polyamide elastomer are compatible with polycaprolactam, while the polyester or polyether groups promote compatibility with hydrogenated styrene elastomers, further enhancing the overall compatibility of polycaprolactam with the composite, thus compensating for the poor compatibility, appearance, and plasticization inherent in the addition of polycaprolactam. The addition of maleic anhydride-grafted hydrogenated styrene elastomers increases the graft content to compensate for the insufficient adhesion associated with the addition of polypropylene. Furthermore, it increases the content of hydrogenated styrene elastomer in the composite, further improving the tensile strength of the composite.

[0014] It should also be noted that the total mass fraction of polycaprolactam and thermoplastic polyamide elastomer in the nylon-encapsulated TPE composite material is 4% to 38%; the mass ratio of polycaprolactam to thermoplastic polyamide elastomer is (0.6-1.5):1, preferably (0.8-1.2):1, and specifically can be 0.7:1, 0.9:1, 1:1, 1.1:1, 1.3:1, or 1.4:1. In addition, compared to styrene elastomers or maleic anhydride-grafted styrene elastomers, hydrogenated styrene elastomers or maleic anhydride-grafted hydrogenated styrene elastomers have better strength and weather resistance, making them more suitable for the application requirements of encapsulated materials.

[0015] Specifically, the mineral oil is at least one of silicone oil, paraffin oil, cycloalkane oil or aromatic hydrocarbon oil; the polypropylene is at least one of homopolypropylene, block copolymer polypropylene or random copolymer polypropylene, wherein the block copolymer polypropylene is obtained by polymerizing ethylene and propylene, and the random copolymer polypropylene is obtained by polymerizing ethylene and propylene; the maleic anhydride grafted polypropylene is at least one of maleic anhydride grafted homopolypropylene, maleic anhydride grafted copolymer polypropylene or maleic anhydride grafted random copolymer polypropylene.

[0016] Preferably, the nylon encapsulated TPE composite material comprises the following components in parts by weight:

[0017] 15-25 parts of hydrogenated styrene elastomer, 30-50 parts of mineral oil, 10-15 parts of polypropylene, 8-12 parts of polycaprolactam, 8-12 parts of thermoplastic polyamide elastomer, 10-15 parts of maleic anhydride grafted polypropylene, 10-15 parts of maleic anhydride grafted olefin copolymer elastomer, 10-15 parts of maleic anhydride grafted hydrogenated styrene elastomer, 10-15 parts of filler, and 0.1-1.5 parts of additives.

[0018] Optionally, the melting point of the polycaprolactam is less than 240° C., preferably 200-220° C. TPE elastomers cannot withstand high-temperature extrusion. Therefore, considering the current TPE molding process, the melting point of the polycaprolactam is selected to be less than 240° C., preferably 200-220° C. Too high a melting point will result in processing and extrusion failure.

[0019] Optionally, the hydrogenated styrene elastomer is at least one of a hydrogenated styrene-butadiene block copolymer or a hydrogenated styrene-isoprene block copolymer; the maleic anhydride grafted hydrogenated styrene elastomer is at least one of a maleic anhydride grafted hydrogenated styrene-butadiene block copolymer or a maleic anhydride grafted hydrogenated styrene-isoprene block copolymer.

[0020] Specifically, the thermoplastic polyamide elastomer is at least one of a polyether block amide block copolymer, a polyether ester amide block copolymer or a polyester amide block copolymer.

[0021] Optionally, the maleic anhydride grafted olefin copolymer elastomer is at least one of a maleic anhydride grafted ethylene-propylene copolymer elastomer or a maleic anhydride grafted ethylene-octene copolymer elastomer.

[0022] Specifically, the filler is at least one of white carbon black, wollastonite, calcium carbonate, glass beads, talc, kaolin, diatomaceous earth, barium sulfate or mica; and the auxiliary agent is at least one of an antioxidant, a light stabilizer or a lubricant.

[0023] Optionally, the antioxidant may be one or more of 2,6-di-tert-butyl-4-methylphenol, antioxidant 1010, antioxidant 1076, antioxidant 1790, antioxidant 168, or antioxidant 626;

[0024] The above-mentioned light stabilizer can be a compound mixture of a hindered amine light stabilizer and a triazine light stabilizer, for example, the mass ratio of the hindered amine light stabilizer to the triazine light stabilizer is 2:(0.5-1.5); the hindered amine light stabilizer can be one or more of light stabilizer 622, light stabilizer 770, light stabilizer 944, light stabilizer 783, light stabilizer 791, light stabilizer 3853, light stabilizer 292 or light stabilizer 123; the triazine light stabilizer is one or more of UV-234, UV-236 or UV-2373.

[0025] The lubricant is one or more of vinyl bisstearamide, hydroxy fatty acid lubricant, erucamide, zinc stearate, magnesium stearate or polyethylene wax.

[0026] The present invention also protects a method for preparing a nylon-encapsulated TPE composite material, comprising the following steps:

[0027] S1. The hydrogenated styrene elastomer is mixed with mineral oil to form a solid step material;

[0028] S2. The solid first-stage material in S1 is mixed with polypropylene, polycaprolactam, thermoplastic polyamide elastomer, maleic anhydride grafted polypropylene, maleic anhydride grafted olefin copolymer elastomer, maleic anhydride grafted hydrogenated styrene elastomer, fillers, and additives, and melt-extruded to obtain a nylon-encapsulated TPE composite material.

[0029] Optionally, step S1 specifically comprises: adding hydrogenated styrene elastomer into a high-speed stirring device, and then spraying and mixing mineral oil according to a required proportion to form a solid one-step material;

[0030] In step S2, a twin-screw extruder can be used for melt extrusion, the aspect ratio of the twin-screw extruder is ≥42:1, and the temperature of the melt extrusion is 170-250°C.

[0031] The application of the above-mentioned nylon encapsulated TPE composite material in the encapsulation of power tool handles, game controllers and automotive parts is also within the scope of protection of the present invention.

[0032] The present invention also protects a rubber-coated nylon product, comprising a nylon matrix and a coating agent coated on the surface of the nylon matrix, wherein the coating agent is the above-mentioned nylon rubber-coated TPE composite material.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The nylon-encapsulated TPE composite material of the present invention combines polypropylene, maleic anhydride-grafted polypropylene and polycaprolactam, and is used in combination with a thermoplastic polyamide elastomer, a hydrogenated styrene elastomer and a maleic anhydride-grafted hydrogenated styrene elastomer. The large number of amide groups in the polycaprolactam are utilized, and after the amide groups work together with the polypropylene and the maleic anhydride-grafted polypropylene, not only the strength and toughness of the composite material can be effectively improved, but also its encapsulation performance can be significantly improved. The addition of the thermoplastic polyamide elastomer not only increases the elastomer content to improve the feel and appearance of the composite material, but also improves the compatibility of the polycaprolactam with the overall composite material, thereby compensating for the defects of poor compatibility, poor appearance and poor plasticization caused by the addition of polycaprolactam, and obtaining a nylon-encapsulated TPE composite material with high adhesion, excellent mechanical properties and good appearance. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with specific embodiments, but the examples do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the examples of the present invention are conventionally purchased raw materials and reagents.

[0036] 1. Raw materials and reagents

[0037] (1) Hydrogenated styrene elastomer

[0038] A: Hydrogenated styrene-butadiene block copolymer, brand SEBS 7551, manufactured by Lee Chang-jung of Taiwan, China;

[0039] (2) Mineral oil

[0040] B: cycloparaffin oil, grade 500N, commercially available;

[0041] (3) Polypropylene

[0042] C1: random copolymer polypropylene, brand PP RJ766MO, manufactured by Borouge Chemicals;

[0043] C2: block copolymer polypropylene, brand PP K7100, manufactured by China Yanshan Petrochemical;

[0044] C3: Homopolymer polypropylene, brand PP HP-500N, manufacturer Basel.

[0045] (4) Polyamide

[0046] D1: Polycaprolactam-1 (PA6), melting point 214, brand MAZMID-B-153, manufacturer Mazzaferro, Brazil;

[0047] D2: polycaprolactam-2 (PA6), melting point 203 ° C, brand 126, manufacturer Austria SAX;

[0048] D3: Polylaurolactam (PA612), melting point 218°C, brand Zytel 151L, manufacturer DuPont, USA.

[0049] (5) Thermoplastic polyamide elastomer

[0050] E1: segmented polyetheramide elastomer, brand name Pebax 5533SA 01, manufactured by Arkema, France;

[0051] E2: Polyether TPU, brand 750U, manufacturer Covestro;

[0052] (6) Maleic anhydride grafted polypropylene

[0053] F: Maleic anhydride graft copolymer polypropylene, brand AD-105, manufacturer: Bochen Polymer, Nanhai, China;

[0054] (7) Maleic anhydride grafted olefin copolymer elastomer

[0055] G: maleic anhydride grafted ethylene-octene copolymer elastomer, brand W1A, manufacturer China Coase;

[0056] (8) Maleic anhydride grafted hydrogenated styrene elastomer

[0057] H: maleic anhydride grafted hydrogenated styrene-butadiene block copolymer, brand SEBS KRATON FG1901, manufacturer Kraton, USA;

[0058] (9) The filler is heavy calcium carbonate, brand CC903, manufactured by China Kelong Powder;

[0059] (10) The auxiliary agent is prepared by compounding an antioxidant and a light stabilizer in a mass ratio of 6:5. Any antioxidant and light stabilizer can be applied to the present invention. There is no limitation on the types of the antioxidant and light stabilizer. The antioxidant can be a single antioxidant or a combination of multiple antioxidants. To better illustrate the effect of the present invention, the antioxidants in the examples and comparative examples are prepared by compounding Irganox 1010 and Irganox 1076 in a mass ratio of 1:5. The light stabilizer is specifically Cyasorb UV-3808pps.

[0060] 2. The nylon-coated TPE composite materials of the embodiments and comparative examples of the present invention were prepared by the following preparation method:

[0061] S1. The hydrogenated styrene elastomer is mixed with mineral oil to form a solid one-step material;

[0062] S2. The solid first-stage material in S1 is mixed with polypropylene, polycaprolactam, thermoplastic polyamide elastomer, maleic anhydride grafted polypropylene, maleic anhydride grafted olefin copolymer elastomer, maleic anhydride grafted hydrogenated styrene elastomer, fillers and additives, and then added to a twin-screw extruder for melt extrusion to obtain a nylon-encapsulated TPE composite material; wherein the aspect ratio of the twin-screw extruder is 42:1, and the melt extrusion temperature is 200-240°C.

[0063] 3. Performance testing

[0064] (1) Adhesion Strength Test Method: According to GB / T 7760-2003, the nylon-coated TPE composite materials of each embodiment and comparative example were injection molded onto a nylon substrate strip composed of PA6 + 30% (mass fraction relative to PA6) glass fiber using an injection molding machine in a specific mold. The injection molding temperature was 235°C. After being placed at room temperature for 24 hours, the strip was stretched using a high-end stretching machine and subjected to a 90° peel test to measure the adhesion between the nylon-coated TPE composite material and the nylon substrate strip. The adhesion strength grades are classified as follows:

[0065] A: It can be peeled off easily, and the peeling surface is smooth and without residue;

[0066] B: The peeling force is large, and the residue on the peeling surface is as high as 50%;

[0067] C: Difficult to peel off corners, residue is 50%-99%, and the peeling force is large;

[0068] D: Difficult to peel off corners, TPE is broken, and the peeling force is very high.

[0069] (2) Tensile Strength Test Method: According to ISO 527-2012, the nylon-coated TPE composite materials in each example and comparative example were injection molded into a standard 2*100*100 mm square plate. The plates were then cut into two types of strips using a cutter. The strips were allowed to stand at room temperature for 24 hours before being tested using a tensile machine. The molding cycle was based on the cycle of the injection-molded tensile strips.

[0070] (3) Appearance test method: After the nylon-coated TPE composite materials in each embodiment and comparative example are injection-molded into a 2*100*100 mm standard square plate, the plate is placed at room temperature for 24 hours and then the appearance is observed with the naked eye to see if there is any cloud pattern. The appearance grade is divided into the following categories:

[0071] A: The surface is not shiny and has severe moiré;

[0072] B: The surface is not shiny and has slight moiré;

[0073] C: No moiré, but other patterns appear;

[0074] D: The surface is bright and has no wrinkles.

[0075] Examples 1 to 10 and Comparative Examples 1 to 4

[0076] The weight percentages of the components in the nylon-coated TPE composite materials in Examples 1 to 10 and Comparative Examples 1 to 4 are shown in Table 1.

[0077] Table 1 Weight percentage of each component of the nylon encapsulated TPE composite material in Examples 1 to 10 and Examples 1 to 4

[0078] The performance test results of the nylon encapsulated TPE composite materials in each embodiment and comparative example according to the above-mentioned method are shown in Table 2.

[0079] Table 2 Test results of various embodiments and comparative examples

[0080] According to the data in Table 1, the nylon encapsulated TPE composite materials in Examples 1 to 10 not only have excellent bonding strength, with the bonding grade reaching Class B or above and the bonding force reaching 2.3 N / mm or above; they also have good appearance performance, with the appearance grade reaching Class C or above; they also have good tensile properties, with the tensile strength reaching 2.4 MPa or above, indicating that the nylon encapsulated TPE composite materials of the present invention have high bonding strength, excellent mechanical properties and good appearance.

[0081] At the same time, as can be seen from Examples 1 to 3, the type of polypropylene has little effect on the appearance of the nylon-encapsulated TPE composite material, but mainly affects the adhesion and bonding grade of the nylon-encapsulated TPE composite material. Compared with homopolypropylene, random copolymer polypropylene and copolymer polypropylene have better adhesion properties, and random copolymer polypropylene is superior to copolymer polypropylene. In addition, according to Example 1 and Comparative Examples 2 and 3, it can be seen that only when polycaprolactam and thermoplastic polyamide elastomer work together can the adhesion and appearance properties of the nylon-encapsulated TPE composite material be significantly improved.

[0082] The above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the claims of the present invention.

Claims

1. A nylon-coated TPE composite material, characterized in that, By weight parts, it comprises the following components: 10 - 30 parts of hydrogenated styrenic elastomer, 20 - 60 parts of mineral oil, 5 - 20 parts of polypropylene, 5 - 15 parts of polycaprolactam, 5 - 15 parts of thermoplastic polyamide elastomer, 5 - 20 parts of maleic anhydride grafted polypropylene, 5 - 20 parts of maleic anhydride grafted olefin copolymer elastomer, 5 - 20 parts of maleic anhydride grafted hydrogenated styrenic elastomer, 0 - 50 parts of filler, 0 - 2 parts of auxiliary agent.

2. The nylon-coated TPE composite material according to claim 1, wherein By weight parts, it comprises the following components: 15 - 25 parts of hydrogenated styrenic elastomer, 30 - 50 parts of mineral oil, 10 - 15 parts of polypropylene, 8 - 12 parts of polycaprolactam, 8 - 12 parts of thermoplastic polyamide elastomer, 10 - 15 parts of maleic anhydride grafted polypropylene, 10 - 15 parts of maleic anhydride grafted olefin copolymer elastomer, 10 - 15 parts of maleic anhydride grafted hydrogenated styrenic elastomer, 10 - 15 parts of filler, 0.1 - 1.5 parts of auxiliary agent.

3. The nylon-coated TPE composite material according to claim 1, wherein The melting point of the polycaprolactam < 240 °C.

4. The nylon-coated TPE composite material according to claim 3, wherein The melting point of the polycaprolactam is 200 - 220 °C.

5. The nylon-coated TPE composite material according to claim 1, wherein The hydrogenated styrenic elastomer is at least one of hydrogenated styrene - butadiene block copolymer or hydrogenated styrene - isoprene block copolymer; The maleic anhydride grafted hydrogenated styrenic elastomer is at least one of maleic anhydride grafted hydrogenated styrene - butadiene block copolymer or maleic anhydride grafted hydrogenated styrene - isoprene block copolymer.

6. The nylon-coated TPE composite material according to claim 1, wherein The thermoplastic polyamide elastomer is at least one of polyetheramide block copolymer, polyetheresteramide block copolymer or polyesteramide block copolymer.

7. The nylon-coated TPE composite material according to claim 1, characterized in that, The maleic anhydride grafted olefin copolymer elastomer is at least one of maleic anhydride grafted ethylene - propylene copolymer elastomer or maleic anhydride grafted ethylene - octene copolymer elastomer.

8. A method for preparing the nylon-coated TPE composite material according to any one of claims 1 to 7, characterized in that, It comprises the following steps: S1. Mix the hydrogenated styrenic elastomer and the mineral oil to form a solid one - step material; S2. Mix the solid one - step material in S1 with polypropylene, polycaprolactam, thermoplastic polyamide elastomer, maleic anhydride grafted polypropylene, maleic anhydride grafted olefin copolymer elastomer, maleic anhydride grafted hydrogenated styrenic elastomer, filler and auxiliary agent, and then carry out melt extrusion at a temperature of 170 - 250 °C to obtain the nylon - coated TPE composite material.

9. Application of the nylon - coated TPE composite material according to any one of claims 1 - 7 in the coating of electric tool handles, game handle coatings and vehicle part coatings.

10. A rubber-coated nylon product, comprising a nylon matrix and a coating agent coated on the surface of the nylon matrix, characterized in that, The coating agent is the nylon - coated TPE composite material according to any one of claims 1 - 7.

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