Multilayer polyolefin elastomer artificial leather with high softness and high peeling force

Abstract

The invention belongs to the technical field of polyolefin artificial leather, and particularly relates to a multilayer polyolefin elastomer artificial leather with high softness and high peeling force, comprising: a base fabric layer, an adhesive modification layer, a graphene modification layer and a coating layer which are sequentially stacked; the graphene modification layer comprises a polyolefin elastomer, a rubber elastomer and a graphene microsheet; the adhesive modification layer comprises a polyolefin elastomer, a modified polyolefin elastomer and a tackifying resin; wherein the graphene modification layer and the adhesive modification layer are radiation cross-linked foaming layers, and the cross-linking degree is 10%-90%; the invention forms a network cross-linked structure after radiation foaming by adding epoxy-group graphene oxide modified polyolefin elastomer, and since the epoxy group increases the C-C bond length and weakens the C-C bond, the graphene nanosheet can achieve interlayer slippage and longitudinal compression rebound on the network molecular chain, thereby significantly improving the toughness and resilience of the artificial leather, and the softness is high.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer compound compositions, and specifically relates to polyolefin artificial leather, in particular to a multi-layer polyolefin elastomer artificial leather with high softness and high peeling force. Background Art

[0002] With the development of industrialization, artificial leather, as a plastic material that imitates animal leather, not only has the same touch and function as leather, but also has a series of advantages such as better wear resistance, easy maintenance, and low price. It is widely used in clothing, shoes, bags, car interiors and other fields, and has become an indispensable material in people's daily life. The traditional artificial leather material polyvinyl chloride (PVC) relies heavily on the use of plasticizers in the process of making artificial leather. Since plasticizers are small molecules with high degrees of freedom, this will cause the surface of PVC to become brittle, and low temperature will aggravate this phenomenon; polyolefin elastomer (TPO) has the advantages of extremely low odor, no reliance on organic solvents during the synthesis process, and aging resistance, but as a non-polar molecule, it has poor viscosity, which leads to many difficulties in the patching process, and it lacks a soft feel.

[0003] Therefore, how to overcome the insufficient softness of artificial leather made from polyolefins is a technical problem that needs to be solved urgently in this field.

[0004] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Summary of the invention

[0005] The embodiments of the present disclosure at least provide a multi-layer polyolefin elastomer artificial leather with high softness and high peeling force.

[0006] The disclosed embodiment provides a multilayer polyolefin elastomer artificial leather with high softness and high peeling force, comprising: a base fabric layer, an adhesive modification layer, a graphene modification layer and a coating layer stacked in sequence; the graphene modification layer comprises a polyolefin elastomer, a rubber elastomer and graphene microsheets; the adhesive modification layer comprises a polyolefin elastomer, a modified polyolefin elastomer and a tackifying resin; wherein the graphene modified layer is a radiation cross-linked foaming layer with a cross-linking degree of 10%-90%; the modified polyolefin elastomer is a polyolefin elastomer grafted with at least one of maleic anhydride, methyl methacrylate, butyl methacrylate, ethyl acrylate, acrylonitrile, styrene and vinyl acetate; the graphene microsheets are epoxy graphene oxide.

[0007] In an optional embodiment, the graphene modified layer comprises the following components in parts by weight: 50-70 parts of polyolefin elastomer; 30-50 parts of rubber elastomer; 1-5 parts of graphene microsheets; 1-10 parts of a cross-linking agent; 0.5-5 parts of an antioxidant; and 0.1-2 parts of an ultraviolet absorber.

[0008] In an optional embodiment, the bonding modification layer includes 60-95 parts of polyolefin elastomer; 10-40 parts of modified polyolefin elastomer; 10-30 parts of tackifying resin; 1-10 parts of co-crosslinking agent; 0.1-1 parts of antioxidant; and 0.1-2 parts of ultraviolet absorber.

[0009] In an optional embodiment, the polyolefin elastomer includes any one or more combinations of polyethylene, ethylene and α-olefin copolymer, polypropylene, propylene and α-olefin copolymer; and the melting point of the polyolefin elastomer is ≤120°C and the Shore A hardness is ≤91.

[0010] In an optional embodiment, the rubber elastomer includes any one or more combinations of silicone rubber, nitrile rubber, natural rubber, EPDM rubber, EPDM rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, cis-butadiene-butadiene rubber, hydrogenated styrene-butadiene-styrene block copolymer, and hydrogenated styrene-isoprene-styrene block copolymer.

[0011] In an optional embodiment, the tackifying resin comprises any one or more combinations of C4 / C8 hydrocarbon resin, synthetic polyterpenes, rosin, rosin esters and natural terpenes; and the softening point of the tackifying resin is ≤120°C.

[0012] In an optional embodiment, the auxiliary cross-linking agent includes any one or more combinations of monofunctional acrylate, difunctional acrylate, trifunctional acrylate and multifunctional acrylate.

[0013] In an optional embodiment, the antioxidant includes any one of a hindered phenol antioxidant, a thioether antioxidant and a phosphite antioxidant.

[0014] In an optional embodiment, the ultraviolet absorber includes any one of salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, and triazines.

[0015] In an optional embodiment, the irradiation uses any one of high-energy electron beams, α rays, β rays, γ rays and X-rays, and the total radiation dose is 50-200 kGy.

[0016] In an optional embodiment, the base fabric layer includes any one or more combinations of wool fabric, plain fabric, polyester fabric, nylon fabric, microfiber base fabric, stretch fabric and non-woven fabric.

[0017] In an optional embodiment, the sum of the thicknesses of the base fabric layer, the bonding modified layer and the graphene modified layer is 0.1-2 mm; the thickness of the coating layer is 0.01-1 mm; wherein the coating of the coating layer comprises any one or more combinations of polyurethane, silicone and polyacrylate.

[0018] The beneficial effect of the present invention is that the multilayer polyolefin elastomer artificial leather with high softness and high peeling force forms a network cross-linked structure after irradiation foaming by adding epoxy-group graphene oxide modified polyolefin elastomer, and the epoxy group increases the CC bond length and weakens the CC bond, so that the graphene nanosheets can achieve interlayer slip and longitudinal compression rebound on the network molecular chain, thereby significantly improving the toughness and resilience of the artificial leather and having high softness.

[0019] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic structural diagram of a multi-layer polyolefin elastomer artificial leather with high softness and high peel strength provided in an embodiment of the present disclosure.

[0023] In the figure:

[0024] 1. Base fabric layer; 2. Adhesive modification layer; 3. Graphene modification layer; 4. Coating layer. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Therefore, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, so that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or superior to other implementations, aspects, or designs. On the contrary, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0027] Herein, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as "at least one of..." modify the entire list of elements when following a list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0028] The terms used herein are only used to describe specific exemplary configurations and are not intended to be limited. As used herein, the singular articles "one", "an" and "the" may also be intended to include plural forms, unless it is clearly indicated above that this is not the case. The terms "comprise", "include" and "have" are inclusive, and therefore specify the presence of features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or combinations thereof. The method steps, processes and operations described herein should not be interpreted as necessarily requiring them to be performed in the specific order discussed or shown, unless specifically identified as an execution order. Additional or alternative steps may be adopted.

[0029] The disclosed embodiment provides a multilayer polyolefin elastomer artificial leather with high softness and high peeling force, comprising: a base fabric layer, an adhesive modification layer, a graphene modification layer and a coating layer stacked in sequence; the graphene modification layer comprises a polyolefin elastomer, a rubber elastomer and graphene microsheets; the adhesive modification layer comprises a polyolefin elastomer, a modified polyolefin elastomer and a tackifying resin; wherein the graphene modified layer is a radiation cross-linked foaming layer with a cross-linking degree of 10%-90%; the modified polyolefin elastomer is a polyolefin elastomer grafted with at least one of maleic anhydride, methyl methacrylate, butyl methacrylate, ethyl acrylate, acrylonitrile, styrene and vinyl acetate; the graphene microsheets are epoxy graphene oxide.

[0030] In some embodiments, specifically, the graphene modified layer includes the following components in parts by weight: 50-70 parts of polyolefin elastomer; 30-50 parts of rubber elastomer; 1-5 parts of graphene microsheets; 1-10 parts of a cross-linking agent; 0.5-5 parts of an antioxidant; and 0.1-2 parts of an ultraviolet absorber.

[0031] In some embodiments, specifically, the graphene microsheets are graphene oxide, preferably epoxy graphene oxide.

[0032] In some embodiments, specifically, the bonding modification layer includes 60-95 parts of polyolefin elastomer; 10-40 parts of modified polyolefin elastomer; 10-30 parts of tackifying resin; 1-10 parts of co-crosslinking agent; 0.1-1 parts of antioxidant; and 0.1-2 parts of ultraviolet absorber.

[0033] In some embodiments, specifically, the polyolefin elastomer includes any one or more combinations of polyethylene, ethylene and α-olefin copolymer, polypropylene, propylene and α-olefin copolymer; and the melting point of the polyolefin elastomer is ≤120°C, and the Shore A hardness is ≤91.

[0034] In some embodiments, specifically, the rubber elastomer includes any one or more combinations of silicone rubber, nitrile rubber, natural rubber, EPDM rubber, EPDM rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, cis-butadiene-butadiene rubber, hydrogenated styrene-butadiene-styrene block copolymer, and hydrogenated styrene-isoprene-styrene block copolymer.

[0035] In some embodiments, specifically, the tackifying resin includes any one or more combinations of C4 / C8 hydrocarbon resin, synthetic polyterpene, rosin, rosin ester and natural terpene; and the softening point of the tackifying resin is ≤120°C.

[0036] In some embodiments, specifically, the auxiliary cross-linking agent includes any one or more combinations of monofunctional acrylates, difunctional acrylates, trifunctional acrylates and multifunctional acrylates, preferably pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate and trimethylolpropane triacrylate.

[0037] In some embodiments, specifically, the antioxidant includes any one of a hindered phenol antioxidant, a thioether antioxidant, and a phosphite antioxidant.

[0038] In some embodiments, specifically, the ultraviolet absorber includes any one of salicylates, benzophenones, benzotriazoles, substituted acrylonitriles, and triazines.

[0039] In some embodiments, specifically, the irradiation uses any one of high-energy electron beams, α rays, β rays, γ rays and X-rays, and the total radiation dose is 50-200 kGy.

[0040] In some embodiments, specifically, the base fabric layer includes any one or more combinations of wool fabric, plain fabric, polyester fabric, nylon fabric, microfiber base fabric, stretch fabric and non-woven fabric.

[0041] In some embodiments, specifically, the sum of the thicknesses of the base fabric layer, the bonding modification layer and the graphene modification layer is 0.1-2 mm; the thickness of the coating layer is 0.01-1 mm; wherein the coating of the coating layer includes any one or more combinations of polyurethane, silicone and polyacrylate.

[0042] Some embodiments of the present invention will be described in detail below. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0043] In some embodiments, specifically, the polyurethane resin solution layer in the artificial leather is a conventional solvent-free polyurethane resin solution slurry formula with a thickness of 0.01 mm, and the polyolefin elastomer composite layer is a two-layer composite structure consisting of a bonding modified layer and a graphene modified layer. The raw materials of the graphene modified layer are shown in Table 1, wherein the polyolefin elastomer is Dow 8678, the rubber elastomer is nitrile rubber, the co-crosslinking agent is triallyl isocyanurate, and the antioxidant is tetra[β-(3.5-di-tert-butyl, 4-hydroxyphenyl) propionic acid ], the ultraviolet absorber is 2-hydroxy-4-octyloxybenzophenone, and the thickness is 0.1mm; the raw materials of the bonding modified layer are shown in Table 2, wherein the polyolefin elastomer is Dow 8678, the modified polyolefin elastomer is grafted with maleic anhydride, the tackifying resin is C4 petroleum resin, the auxiliary cross-linking agent is triallyl isocyanurate, the antioxidant is tetrakis[β-(3.5-di-tert-butyl, 4-hydroxyphenyl) propionic acid], and the ultraviolet absorber is 2-hydroxy-4-octyloxybenzophenone, and the thickness is 0.1mm.

[0044] In some embodiments, specifically, the method for preparing the high-softness and high-peelability artificial leather comprises the following steps:

[0045] S1. The polyolefin elastomer, rubber elastomer, cross-linking agent, antioxidant, UV absorber, tackifying resin, graphene microsheets and modified polyolefin elastomer were stirred at 50° C. for 4 h to mix;

[0046] S2. The mixture is extruded through a twin-screw extruder and thermally bonded to the base fabric, and the surface of the modified layer is radiation cross-linked to obtain a multilayer polyolefin elastomer substrate;

[0047] S3. Coating a polyurethane resin solution on the surface of a multi-layer polyolefin elastomer substrate, and performing embossing treatment after curing to obtain a multi-layer polyolefin elastomer artificial leather.

[0048] In some embodiments, specifically, each raw material in Table 1 and Table 2 is measured by weight, wherein Table 1 is the weight percentage of the raw materials of the graphene modified layer, and Table 2 is the weight percentage of the raw materials of the bonding modified layer.

[0049] Table 1 Weight percentage of raw materials for graphene modified layer

[0050]

[0051] Table 2 Weight percentage of raw materials for bonding modified layer

[0052]

[0053] In some embodiments, specifically, the crosslinking degree of the graphene modified layer and the bonding modified layer in the polyolefin elastomer artificial leather prepared in Examples 1 to 4 and Comparative Examples 1 to 3, the Shore hardness of the graphene modified layer, and the interlayer peeling strength data between the bonding modified layer and the base fabric layer are shown in Table 3 below: The crosslinking degree is tested according to the xylene extraction method in GB / T 29848-2018-5.5.3, the Shore hardness is tested according to GB / T 2411-2008, and the interlayer adhesion is tested according to GB / T 14905-2009.

[0054] Table 3 Performance parameters of artificial leather of Examples 1-4 and Comparative Examples 1-3

[0055]

[0056] Specifically, the addition of graphene microsheets is reduced in the graphene modified layer of Comparative Example 1 compared with Example 1, and the addition of graphene microsheets is reduced in Comparative Example 2 compared with Example 4. At the same time, the components of the bonding modified layer of Comparative Example 1 are the same as those of Example 1, and the components of the bonding modified layer of Comparative Example 2 are the same as those of Example 4. It can be seen that after the addition of graphene microsheets for modification, the epoxy group increases the CC bond length and weakens the CC bond, so that the graphene nanosheets can achieve interlayer slip and longitudinal compression rebound on the network molecular chain, thereby significantly improving the toughness and resilience of the artificial leather. Therefore, the hardness of Comparative Example 1 is much higher than that of Example 1 in terms of Shore hardness, and the hardness of Comparative Example 2 is also much higher than that of Example 4.

[0057] Specifically, compared with Example 1, Example 2 and Example 3 further adjusted the proportion of graphene microsheets. It can be seen that as the proportion of graphene microsheets increases within a certain range, the softness shows a synchronous upward trend. However, the softness of artificial leather is also related to the ratio of the proportions of polyolefin elastomer and rubber elastomer. When too much rubber elastomer is added and too little graphene microsheets are added, the softness is insufficient.

[0058] Specifically, in the bonding modified layer, Comparative Example 3 reduces the amount of modified polyolefin elastomer added compared to Example 1. In the absence of the modified polyolefin elastomer, the peel strength of the bonding modified layer is greatly reduced. This is because the grafted polyolefin elastomer chain segments contain multiple functional groups, which bond with the polyester fibers of the base fabric, thereby enhancing the peel strength between the leather and the base fabric. The remaining embodiments also refer to this mechanism.

[0059] In summary, the multilayer polyolefin elastomer artificial leather with high softness and high peeling force forms a network cross-linked structure after irradiation foaming by adding epoxy graphene oxide modified polyolefin elastomer. Since the epoxy group increases the CC bond length and weakens the CC bond, the graphene nanosheets can achieve interlayer slip and longitudinal compression rebound on the network molecular chain, thereby significantly improving the toughness and resilience of the artificial leather and having high softness.

[0060] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A multi-layer polyolefin elastomer artificial leather with high softness and high peeling force, characterized in that: include: A base fabric layer, an adhesive modification layer, a graphene modification layer and a coating layer are sequentially stacked; The graphene modified layer comprises a polyolefin elastomer, a rubber elastomer and graphene microsheets; The bonding modification layer comprises a polyolefin elastomer, a modified polyolefin elastomer and a tackifying resin; The graphene modified layer is a radiation cross-linked foaming layer with a cross-linking degree of 10%-90%; The modified polyolefin elastomer is a polyolefin elastomer grafted with at least one of maleic anhydride, methyl methacrylate, butyl methacrylate, ethyl acrylate, acrylonitrile, styrene and vinyl acetate; The graphene microsheet is epoxy-based graphene oxide; The graphene modified layer comprises the following components in parts by weight: 50-70 parts of polyolefin elastomer; 30-50 parts of rubber elastomer; 1-5 parts of graphene microsheets; 1-10 parts of a cross-linking agent; 0.5-5 parts of an antioxidant; and 0.1-2 parts of an ultraviolet absorber.

2. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The bonding modification layer comprises 60-95 parts of polyolefin elastomer, 10-40 parts of modified polyolefin elastomer, 10-30 parts of tackifying resin, 1-10 parts of auxiliary cross-linking agent, 0.1-1 parts of antioxidant and 0.1-2 parts of ultraviolet absorber.

3. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The polyolefin elastomer comprises any one or more combinations of polyethylene, ethylene and α-olefin copolymers, polypropylene, and propylene and α-olefin copolymers; and The polyolefin elastomer has a melting point of ≤120° C. and a Shore A hardness of ≤91.

4. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The rubber elastomer includes any one or more combinations of silicone rubber, nitrile rubber, natural rubber, EPDM rubber, EPDM rubber, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, cis-butadiene-butadiene rubber, hydrogenated styrene-butadiene-styrene block copolymer, and hydrogenated styrene-isoprene-styrene block copolymer.

5. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The tackifying resin comprises any one or more combinations of C4 / C8 hydrocarbon resins, synthetic polyterpenes, rosin, rosin esters and natural terpenes; and The softening point of the tackifying resin is ≤120°C.

6. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The auxiliary cross-linking agent includes any one or more combinations of monofunctional acrylate, difunctional acrylate, trifunctional acrylate and multifunctional acrylate; The antioxidant includes any one of a hindered phenol antioxidant, a thioether antioxidant and a phosphite antioxidant; The ultraviolet absorber includes any one of salicylates, benzophenones, benzotriazoles, substituted acrylonitriles and triazines.

7. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The irradiation uses any one of high-energy electron beams, α rays, β rays, γ rays and X rays, and the total radiation dose is 50-200 kGy.

8. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The base fabric layer comprises any one or more combinations of wool fabric, plain fabric, polyester fabric, nylon fabric, microfiber base fabric, stretch fabric and non-woven fabric.

9. The multi-layer polyolefin elastomer artificial leather with high softness and high peeling force as claimed in claim 1, characterized in that: The sum of the thickness of the base fabric layer, the bonding modified layer and the graphene modified layer is 0.1-2 mm; The thickness of the coating layer is 0.01-1 mm; in The coating of the coating layer includes any one or more combinations of polyurethane, silicone and polyacrylate.

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