A soft multi-layer plastic hose and its preparation method and application

Abstract

The present invention provides a soft multi-layer plastic hose and a preparation method and application thereof, belonging to the technical field of plastic hoses. The present invention mixes thermoplastic polyolefin and high-density polyethylene in a mass ratio of 70:30, and extrude the mixture in a multi-layer co-extruder as the outer layer of the soft multi-layer plastic hose. The processing temperature of the outer layer is 180-200°C. Under a fixed ratio and temperature, the thermoplastic polyolefin and high-density polyethylene in the present invention have the best compatibility. The outer layer material prepared after blending has low gloss, low surface granularity, and is comfortable to touch, which is more suitable for the packaging requirements of high-end products.

Description

Technical Field

[0001] The invention relates to the technical field of plastic hoses, and in particular to a soft multi-layer plastic hose and a preparation method and application thereof. Background Art

[0002] Hose packaging is generally made of polyester (PET), polyethylene (PE), and polypropylene (PP) as raw materials. After adding the corresponding organic solvents, it is heated at high temperature and then blow molded, extruded, or injection molded through a plastic mold. Hose packaging is easy to carry, not easy to break, low cost, and easy to produce. It is also acid-resistant and alkali-resistant, meets the requirements of food packaging, and is easy to recycle after use. Therefore, hose packaging has a wide range of applications, including but not limited to the cosmetics industry, food industry, pharmaceutical industry, and chemical industry. In order to meet the requirements of different industries, plastic packaging bottles need to be modified or specially treated differently to meet their application scenarios.

[0003] When a single polyolefin material is used to prepare soft tube packaging, it usually cannot meet the various requirements of different industries. Generally, polyolefins are melt-mixed with related additives or multiple polyolefins to prepare packaging materials. For example, patent CN117801402A discloses a degradable cosmetic soft tube and its preparation method, including 5558 parts of high-density polyethylene, 912 parts of low-density polyethylene, 20-24 parts of metallocene polyethylene, 2528 parts of modified starch, 15-18 parts of modified silica, 1-3 parts of biodegradable agent TDPA™, 36 parts of plasticizer, and 2-3 parts of coupling agent. However, since the ingredients of most additives do not meet the standards of the food industry and the cost is high, they are very limited in industrial production.

[0004] The materials of plastic hoses are generally polyethylene and polypropylene, but the compatibility between polyethylene and polypropylene is poor, so it is necessary to add additives such as compatibilizers or cross-linking agents during the mixing process, which also increases the cost and makes the composition of the hose complicated, affecting its use in many fields. At the same time, although the addition of additives and fillers improves the impact resistance of the hose, it also makes the appearance and surface state of the hose rough and heavy.

[0005] At the same time, the application scenarios of plastic hoses are varied, and most of them require the hoses to have properties such as sealing and anti-oxidation. With the industry's increasing requirements for quality, the appearance and comfort of the hoses are gradually improving, and are not limited to the mechanical properties of the hoses.

[0006] Therefore, the compatibility of polyethylene and thermoplastic polyolefins in plastic hoses is poor, and the surface state of the hoses after preparation is rough, requiring additional printing treatment, and the sealing, pressure resistance and other properties do not meet the standards, which is still an urgent problem to be solved. Summary of the invention

[0007] In response to the above problems, the present invention provides a soft multi-layer plastic hose and a preparation method and application thereof. A soft and comfortable outer layer of the plastic hose is prepared by using specific thermoplastic polyolefin materials and polyethylene materials, and a suitable ratio of the two. At the same time, other layers such as the middle layer and the inner layer are prepared through specific processing technology and conditions, thereby preparing a multi-layer plastic hose with a smooth appearance and high strength.

[0008] The present invention provides a soft multi-layer plastic hose, which has a five-layer structure, and includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is a thermoplastic polyolefin and a high-density polyethylene in a mass ratio of 70:30; the multi-layer plastic hose is prepared by extrusion by a multi-layer co-extruder at different extrusion temperatures between different layers;

[0009] The thickness of the soft multi-layer plastic hose is (0.5-0.55) ± 0.03 mm, the outer diameter of the soft multi-layer plastic hose is 40-50 mm; the glossiness of the soft multi-layer plastic hose is 12.2-12.8; the water vapor barrier property of the soft multi-layer plastic hose is 0.20-0.25%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0631-0.0944 cm 3 / pkg·24h; under the tension of a tensile machine at 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 80-88nm; the soft multi-layer plastic hose will not break under the pressure of 2bars after sealing; the outer surface of the soft multi-layer plastic hose has a comfortable touch and has fragrance retention.

[0010] Furthermore, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is (0.28-0.32): 0.025: 0.025: 0.025: (0.15-0.16).

[0011] Furthermore, the polyethylene has a melt index of 0.2-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.92-0.97 g / cm 3 .

[0012] Furthermore, the adhesive is anhydride-modified linear low-density polyethylene, the melt index of the adhesive at 190°C / 2.16kg is 1.5-3g / 10min, and the density is 0.924g / cm 3 .

[0013] Furthermore, the barrier agent is ethylene-vinyl alcohol copolymer, the melt index of the barrier agent at 210°C / 2.16kg is 4-13g / 10min, and the density is 1.14-1.19g / cm 3 .

[0014] Furthermore, the thermoplastic polyolefin has a melt index of 0.8 g / 10 min at 230°C / 2.16 kg and a density of 0.89 g / cm 3 .

[0015] Furthermore, the high-density polyethylene has a melt index of 0.3-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.941-0.965 g / cm 3 .

[0016] Furthermore, the soft multi-layer plastic hose also includes a masterbatch, which is added into the multi-layer co-extrusion extruder as an inner layer, and the mass ratio of the masterbatch to the polyethylene in the inner layer is (2-8):100.

[0017] The present invention also provides a method for preparing a soft multi-layer plastic hose, comprising the following steps:

[0018] Step 1, adding polyethylene as an inner layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-inner layer into the multi-layer co-extruder, adding ethylene-vinyl alcohol copolymer as a sub-middle layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-outer layer into the multi-layer co-extruder, adding thermoplastic polyolefin and high-density polyethylene as outer layers into the multi-layer co-extruder, and extruding to obtain a round tube embryo;

[0019] Step 2: Add high-density polyethylene into the head injection machine, and transfer the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose.

[0020] Furthermore, the polyethylene in step 1 has a melt index of 0.2-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.92-0.97 g / cm 3 .

[0021] Furthermore, the ethylene-vinyl alcohol copolymer in step 1 has a melt index of 4-13 g / 10 min at 210°C / 2.16 kg and a density of 1.14-1.19 g / cm 3 .

[0022] Furthermore, the anhydride-modified linear low-density polyethylene in step 1 has a melt index of 1.5-3 g / 10 min at 190°C / 2.16 kg and a density of 0.924 g / cm 3 .

[0023] Furthermore, in the step 1, the mass ratio of the thermoplastic polyolefin to the high-density polyethylene is 70:30.

[0024] Furthermore, the thermoplastic polyolefin in step 1 has a melt index of 0.8 g / 10 min at 230°C / 2.16 kg and a density of 0.89 g / cm 3 .

[0025] Furthermore, the high-density polyethylene in step 1 has a melt index of 0.3-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.941-0.965 g / cm 3 .

[0026] Furthermore, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is (0.28-0.32): 0.025: 0.025: 0.025: (0.15-0.16).

[0027] Furthermore, the inner layer extrusion temperature of the multilayer co-extruder in step 1 is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C.

[0028] Furthermore, the sub-inner layer extrusion temperature of the multi-layer co-extruder in step 1 is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C.

[0029] Furthermore, the middle layer extrusion temperature of the multilayer co-extruder in step 1 is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C.

[0030] Furthermore, the extrusion temperature of the secondary outer layer of the multilayer co-extruder in step 1 is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C.

[0031] Furthermore, the outer layer extrusion temperature of the multilayer co-extruder in step 1 is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C.

[0032] Furthermore, the temperature of the die head of the multilayer co-extruder in step 1 is 190°C.

[0033] Furthermore, the high-density polyethylene in step 2 has a melt index of 0.3-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.941-0.965 g / cm 3 .

[0034] Furthermore, the temperature of the injection head of the injection machine in step 2 is 180-320°C, divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

[0035] A packaging hose is the soft multi-layer plastic hose or is prepared from the soft multi-layer plastic hose.

[0036] Beneficial effects of the present invention:

[0037] 1. The present invention mixes thermoplastic polyolefin and high-density polyethylene in a mass ratio of 70:30, and extrude the mixture as the outer layer of the soft multi-layer plastic hose in a multi-layer co-extruder. The processing temperature of the outer layer is 180-200° C. Under a fixed ratio and temperature, the thermoplastic polyolefin and high-density polyethylene in the present invention have the best compatibility. The outer layer material prepared after blending has high smoothness, low surface granularity, and comfortable touch, which is more suitable for the packaging requirements of high-end products.

[0038] 2. The present invention prepares a plastic hose with a five-layer structure by a multi-layer co-extrusion extruder, wherein the inner layer material is polyethylene. The wide applicability and food-grade material properties of polyethylene enable the soft multi-layer plastic hose to be used in the fields of food, medicine, and chemical industry, and are not limited to the above fields. At the same time, the present invention also uses ethylene-vinyl alcohol copolymer as the middle layer, giving the soft multi-layer plastic hose excellent air barrier and water barrier properties. When it is used as food packaging, the food inside it will not deliquescence, and when it is used as medicine or cosmetic packaging, the product inside it will not be denatured or oxidized;

[0039] 3. The present invention also uses anhydride-modified linear low-density polyethylene as the sub-inner layer and the sub-outer layer, and as an adhesive to connect the inner layer and the outer layer. The anhydride-modified linear low-density polyethylene has polarity and compatibility, so that it can effectively bond a variety of materials and show good performance during processing. In the process of melt mixing of the high-density polyethylene and thermoplastic polyolefin in the outer layer structure of the present invention, the high-density polyethylene is relatively stable. The stable high-density polyethylene may affect the crystallization behavior of the thermoplastic polyolefin, its crystallization kinetics and crystal morphology, thereby reducing the particle size of the outer surface of the outer layer and making it comfortable to touch. At the same time, the materials used in the present invention are all non-toxic and harmless green environmentally friendly materials, which are easy to degrade and recycle and will not cause pollution to the environment. The preparation process of the present invention is simple, low-cost, and easy to expand production. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a partial comparison diagram of the hoses in Examples 1 and 2. DETAILED DESCRIPTION

[0041] The invention is described in detail below with reference to the embodiments:

[0042] The present invention provides a soft multi-layer plastic hose and a preparation method and application thereof. The soft multi-layer plastic hose is prepared by a multi-layer co-extrusion process, which greatly improves its barrier properties and mechanical properties and improves the comfort of the soft multi-layer plastic hose.

[0043] Example 1

[0044] This embodiment provides a soft multi-layer plastic hose, which has a five-layer structure, and includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is a thermoplastic polyolefin and a high-density polyethylene in a mass ratio of 70:30; the multi-layer plastic hose is prepared by extrusion of a multi-layer co-extruder at different extrusion temperatures between different layers;

[0045] The thickness of the soft multi-layer plastic hose is 0.5±0.03mm, the outer diameter of the soft multi-layer plastic hose is 40mm; the glossiness of the soft multi-layer plastic hose is 12.6; the water vapor barrier property of the soft multi-layer plastic hose is 0.20%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0944cm 3 / pkg·24h; under the tension of a tensile machine at 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 88nm; after the end is sealed, the soft multi-layer plastic hose will not break under the pressure of 2bars; the outer surface of the soft multi-layer plastic hose has a comfortable touch and has fragrance retention.

[0046] In this embodiment, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is 0.28:0.025:0.025:0.025:0.15;

[0047] The polyethylene has a melt index of 0.2 g / 10 min at 190°C / 2.16 kg and a density of 0.92 g / cm 3 ;

[0048] The adhesive is anhydride-modified linear low-density polyethylene, and the melt index of the adhesive at 190°C / 2.16kg is 1.5g / 10min, and the density is 0.924g / cm 3 ;

[0049] The barrier agent is ethylene-vinyl alcohol copolymer, and the melt index of the barrier agent at 210°C / 2.16kg is 4g / 10min, and the density is 1.14g / cm 3 ;

[0050] The thermoplastic polyolefin has a melt index of 0.8 g / 10 min at 230° C. / 2.16 kg and a density of 0.89 g / cm 3 ;

[0051] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 .

[0052] This embodiment also provides a method for preparing a soft multi-layer plastic hose, comprising the following steps:

[0053] Step 1, adding polyethylene as an inner layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-inner layer into the multi-layer co-extruder, adding ethylene-vinyl alcohol copolymer as a sub-middle layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-outer layer into the multi-layer co-extruder, adding thermoplastic polyolefin and high-density polyethylene as outer layers into the multi-layer co-extruder, and extruding to obtain a round tube embryo;

[0054] Step 2: Add high-density polyethylene into the head injection machine, and transfer the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose.

[0055] In this embodiment, the inner layer extrusion temperature of the multilayer co-extruder is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C;

[0056] The sub-inner layer extrusion temperature of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0057] The middle layer extrusion temperature of the multi-layer co-extruder is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C;

[0058] The extrusion temperature of the secondary outer layer of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0059] The outer layer extrusion temperature of the multi-layer co-extruder is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C;

[0060] The temperature of the die head of the multilayer co-extrusion extruder is 190°C;

[0061] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 ;

[0062] The temperature of the injection head of the injection machine is 180-320°C, which is divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

[0063] Example 2

[0064] This embodiment provides a soft multi-layer plastic hose, which has a five-layer structure, and includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is a thermoplastic polyolefin and a high-density polyethylene in a mass ratio of 70:30; the multi-layer plastic hose is prepared by extrusion of a multi-layer co-extruder at different extrusion temperatures between different layers;

[0065] The thickness of the soft multi-layer plastic hose is 0.5±0.03mm, the outer diameter of the soft multi-layer plastic hose is 40mm; the glossiness of the soft multi-layer plastic hose is 12.2; the water vapor barrier property of the soft multi-layer plastic hose is 0.22%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0608cm 3 / pkg·24h; under the tension of a tensile machine at 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 82nm; after the end is sealed, the soft multi-layer plastic hose will not break under the pressure of 2bars; the outer surface of the soft multi-layer plastic hose has a comfortable touch and has fragrance retention.

[0066] In this embodiment, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is 0.28:0.025:0.025:0.025:0.15;

[0067] The polyethylene has a melt index of 0.5 g / 10 min at 190°C / 2.16 kg and a density of 0.97 g / cm 3 ;

[0068] The adhesive is anhydride-modified linear low-density polyethylene, and the melt index of the adhesive at 190°C / 2.16kg is 3g / 10min, and the density is 0.924g / cm 3 ;

[0069] The barrier agent is ethylene-vinyl alcohol copolymer, and the melt index of the barrier agent at 210°C / 2.16kg is 13g / 10min, and the density is 1.19g / cm 3 ;

[0070] The thermoplastic polyolefin has a melt index of 0.8 g / 10 min at 230° C. / 2.16 kg and a density of 0.89 g / cm 3 ;

[0071] The high-density polyethylene has a melt index of 0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.965 g / cm 3 ;

[0072] The soft multi-layer plastic hose also includes a masterbatch, which is added into the multi-layer co-extrusion extruder as an inner layer, and the mass ratio of the masterbatch to the polyethylene in the inner layer is 2:100.

[0073] This embodiment also provides a method for preparing a soft multi-layer plastic hose, comprising the following steps:

[0074] Step 1, adding masterbatch and polyethylene as inner layers into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a secondary inner layer into the multi-layer co-extruder, adding ethylene-vinyl alcohol copolymer as a secondary intermediate layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a secondary outer layer into the multi-layer co-extruder, adding thermoplastic polyolefin and high-density polyethylene as outer layers into the multi-layer co-extruder, and extruding to obtain a round tube embryo;

[0075] Step 2: Add high-density polyethylene into the head injection machine, and transfer the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose.

[0076] In this embodiment, the inner layer extrusion temperature of the multilayer co-extruder is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C;

[0077] The sub-inner layer extrusion temperature of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0078] The middle layer extrusion temperature of the multi-layer co-extruder is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C;

[0079] The extrusion temperature of the secondary outer layer of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0080] The outer layer extrusion temperature of the multi-layer co-extruder is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C;

[0081] The temperature of the die head of the multilayer co-extrusion extruder is 190°C;

[0082] The high-density polyethylene has a melt index of 0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.965 g / cm 3 ;

[0083] The temperature of the injection head of the injection machine is 180-320°C, which is divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

[0084] like Figure 1 This is a partial comparison diagram of the soft multi-layer plastic hoses described in Examples 1 and 2. In the figure, the hose on the left is the soft multi-layer plastic hose described in Example 1, the surface of the hose is matte, and the surface material is fine. The hose on the right is the soft multi-layer plastic hose described in Example 2. In this embodiment, masterbatch is added to the inner layer, the color is solid, the surface is also matte, and it feels comfortable.

[0085] Example 3

[0086] This embodiment provides a soft multi-layer plastic hose, which has a five-layer structure, and includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is a thermoplastic polyolefin and a high-density polyethylene in a mass ratio of 70:30; the multi-layer plastic hose is prepared by extrusion of a multi-layer co-extruder at different extrusion temperatures between different layers;

[0087] The thickness of the soft multi-layer plastic hose is 0.55±0.03mm, the outer diameter of the soft multi-layer plastic hose is 50mm; the glossiness of the soft multi-layer plastic hose is 12.8; the water vapor barrier property of the soft multi-layer plastic hose is 0.25%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0631cm 3 / pkg·24h; under the tension of a tensile machine at 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 80nm; after the end is sealed, the soft multi-layer plastic hose will not break under the pressure of 2bars; the outer surface of the soft multi-layer plastic hose has a comfortable touch and has fragrance retention.

[0088] In this embodiment, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is 0.32:0.025:0.025:0.025:0.16;

[0089] The polyethylene has a melt index of 0.2 g / 10 min at 190°C / 2.16 kg and a density of 0.92 g / cm 3 ;

[0090] The adhesive is anhydride-modified linear low-density polyethylene, and the melt index of the adhesive at 190°C / 2.16kg is 1.5g / 10min, and the density is 0.924g / cm 3 ;

[0091] The barrier agent is ethylene-vinyl alcohol copolymer, and the melt index of the barrier agent at 210°C / 2.16kg is 4g / 10min, and the density is 1.14g / cm 3 ;

[0092] The thermoplastic polyolefin has a melt index of 0.8 g / 10 min at 230° C. / 2.16 kg and a density of 0.89 g / cm 3 ;

[0093] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 ;

[0094] The soft multi-layer plastic hose also includes a masterbatch, which is added into the multi-layer co-extrusion extruder as an inner layer, and the mass ratio of the masterbatch to the polyethylene in the inner layer is 8:100.

[0095] This embodiment also provides a method for preparing a soft multi-layer plastic hose, comprising the following steps:

[0096] Step 1, adding masterbatch and polyethylene as inner layers into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a secondary inner layer into the multi-layer co-extruder, adding ethylene-vinyl alcohol copolymer as a secondary intermediate layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a secondary outer layer into the multi-layer co-extruder, adding thermoplastic polyolefin and high-density polyethylene as outer layers into the multi-layer co-extruder, and extruding to obtain a round tube embryo;

[0097] Step 2: Add high-density polyethylene into the head injection machine, and transfer the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose.

[0098] In this embodiment, the inner layer extrusion temperature of the multilayer co-extruder is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C;

[0099] The sub-inner layer extrusion temperature of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0100] The middle layer extrusion temperature of the multi-layer co-extruder is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C;

[0101] The extrusion temperature of the secondary outer layer of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0102] The outer layer extrusion temperature of the multi-layer co-extruder is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C;

[0103] The temperature of the die head of the multilayer co-extrusion extruder is 190°C;

[0104] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 ;

[0105] The temperature of the injection head of the injection machine is 180-320°C, which is divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

[0106] Comparative Example 1

[0107] The comparative example provides a soft multi-layer plastic hose, which has a five-layer structure, and includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is high-density polyethylene; the multi-layer plastic hose is prepared by extrusion of a multi-layer co-extruder at different extrusion temperatures between different layers;

[0108] The thickness of the soft multi-layer plastic hose is 0.5±0.03mm, the outer diameter of the soft multi-layer plastic hose is 40mm; the glossiness of the soft multi-layer plastic hose is 38.4; the water vapor barrier property of the soft multi-layer plastic hose is 0.22%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0958cm 3 / pkg·24h; under the tension of a tensile machine at 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 84nm; after the end is sealed, the soft multi-layer plastic hose will not break under the pressure of 2bars; the outer surface of the soft multi-layer plastic hose has a comfortable touch and has fragrance retention.

[0109] In this comparative example, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is 0.28:0.025:0.025:0.025:0.15;

[0110] The polyethylene has a melt index of 0.2 g / 10 min at 190°C / 2.16 kg and a density of 0.92 g / cm 3 ;

[0111] The adhesive is anhydride-modified linear low-density polyethylene, and the melt index of the adhesive at 190°C / 2.16kg is 1.5g / 10min, and the density is 0.924g / cm 3 ;

[0112] The barrier agent is ethylene-vinyl alcohol copolymer, and the melt index of the barrier agent at 210°C / 2.16kg is 4g / 10min, and the density is 1.14g / cm 3 ;

[0113] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 .

[0114] This comparative example also provides a method for preparing a soft multi-layer plastic hose, comprising the following steps:

[0115] Step 1, adding polyethylene as an inner layer into the multi-layer co-extrusion extruder, adding anhydride-modified linear low-density polyethylene as a sub-inner layer into the multi-layer co-extrusion extruder, adding ethylene-vinyl alcohol copolymer as a sub-middle layer into the multi-layer co-extrusion extruder, adding anhydride-modified linear low-density polyethylene as a sub-outer layer into the multi-layer co-extrusion extruder, adding high-density polyethylene as an outer layer into the multi-layer co-extrusion extruder, and extruding to obtain a round tube embryo;

[0116] Step 2: Add high-density polyethylene into the head injection machine, and transfer the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose.

[0117] In this comparative example, the inner layer extrusion temperature of the multilayer co-extruder is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C;

[0118] The sub-inner layer extrusion temperature of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0119] The middle layer extrusion temperature of the multi-layer co-extruder is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C;

[0120] The extrusion temperature of the secondary outer layer of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0121] The outer layer extrusion temperature of the multi-layer co-extruder is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C;

[0122] The temperature of the die head of the multilayer co-extrusion extruder is 190°C;

[0123] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 ;

[0124] The temperature of the injection head of the injection machine is 180-320°C, which is divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

[0125] Comparative Example 2

[0126] The comparative example provides a soft multi-layer plastic hose, which has a five-layer structure, and includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is a thermoplastic polyolefin and a high-density polyethylene in a mass ratio of 30:70; the multi-layer plastic hose is prepared by extrusion of a multi-layer co-extruder at different extrusion temperatures between different layers;

[0127] The thickness of the soft multi-layer plastic hose is 0.5±0.03mm, the outer diameter of the soft multi-layer plastic hose is 40mm; the glossiness of the soft multi-layer plastic hose is 26.2; the water vapor barrier property of the soft multi-layer plastic hose is 0.27%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0732cm 3 / pkg·24h; under the tension of a tensile machine at 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 82nm; after the end is sealed, the soft multi-layer plastic hose will not break under the pressure of 2bars; the outer surface of the soft multi-layer plastic hose has a comfortable touch and has fragrance retention.

[0128] In this comparative example, the thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is 0.28:0.025:0.025:0.025:0.15;

[0129] The polyethylene has a melt index of 0.2 g / 10 min at 190°C / 2.16 kg and a density of 0.92 g / cm 3 ;

[0130] The adhesive is anhydride-modified linear low-density polyethylene, and the melt index of the adhesive at 190°C / 2.16kg is 1.5g / 10min, and the density is 0.924g / cm 3 ;

[0131] The barrier agent is ethylene-vinyl alcohol copolymer, and the melt index of the barrier agent at 210°C / 2.16kg is 4-13g / 10min, and the density is 1.14-1.19g / cm 3 ;

[0132] The thermoplastic polyolefin has a melt index of 0.8 g / 10 min at 230° C. / 2.16 kg and a density of 0.89 g / cm 3 ;

[0133] The high-density polyethylene has a melt index of 0.3-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.941-0.965 g / cm 3 .

[0134] This comparative example also provides a method for preparing a soft multi-layer plastic hose, comprising the following steps:

[0135] Step 1, adding polyethylene as an inner layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-inner layer into the multi-layer co-extruder, adding ethylene-vinyl alcohol copolymer as a sub-middle layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-outer layer into the multi-layer co-extruder, adding thermoplastic polyolefin and high-density polyethylene as outer layers into the multi-layer co-extruder, and extruding to obtain a round tube embryo;

[0136] Step 2: Add high-density polyethylene into the head injection machine, and transfer the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose.

[0137] In this comparative example, the inner layer extrusion temperature of the multilayer co-extruder is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C;

[0138] The sub-inner layer extrusion temperature of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0139] The middle layer extrusion temperature of the multi-layer co-extruder is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C;

[0140] The extrusion temperature of the secondary outer layer of the multi-layer co-extruder is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C;

[0141] The outer layer extrusion temperature of the multi-layer co-extruder is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C;

[0142] The temperature of the die head of the multilayer co-extrusion extruder is 190°C;

[0143] The high-density polyethylene has a melt index of 0.3 g / 10 min at 190°C / 2.16 kg and a density of 0.941 g / cm 3 ;

[0144] The temperature of the injection head of the injection machine is 180-320°C, which is divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

[0145] Table 1 shows the properties of the materials in Examples 1-3 and Comparative Example 1

[0146]

[0147] As shown in Table 1, the soft multi-layer plastic hose in the present invention has low gloss and comfortable touch, while in Comparative Examples 1 and 2, no thermoplastic polyolefin material is added to the outer layer, or the ratio with the thermoplastic polyolefin is different, so the gloss is increased and the touch is different.

[0148] The gloss test conditions in the present invention are: using a gloss meter (WGG60) to randomly select 5 points on the surface of the hose to test the gloss, and calculate the average value to obtain the gloss of the hose;

[0149] The test conditions for water vapor barrier properties are as follows: the initial weight of the hose is W0, purified water is added to the soft multi-layer plastic hose after sealing to 3 / 4 of the full capacity, the lid is tightened, the torque is 30N·cm-90N·cm, the outer surface is wiped clean with silk cloth, and the weight of the hose at this time is W1, and then the soft multi-layer plastic hose is placed in a constant temperature and humidity chamber at a temperature of 40℃±2℃ and a relative humidity of 25%±5% for 14 days. After being taken out, it is placed at room temperature for 45 minutes and then weighed again, and the weight of the hose at this time is W2. The water vapor barrier property is expressed by (W1- W2) / (W1- W0)*100%;

[0150] The test standard for oxygen barrier properties is "ASTMF1307-02";

[0151] The test conditions for the deformation amount are as follows: take a 15 mm sample of the soft multi-layer plastic hose, clamp the two ends of the sample on the clamp of the tensile machine, set the stretching speed to 100 mm / min, the tension to 60 N, and measure the deformation of the sample at this time;

[0152] The conditions of the compression test are as follows: after sealing the end of the soft multi-layer plastic hose, cool it in a greenhouse for 10 minutes, squeeze the soft multi-layer plastic hose at 2 bars, and observe the state of the hose.

[0153] In the present invention, the materials and conditions for the tail seal are the same as those for the injection head and are not limited thereto.

[0154] From the above, it can be seen that the soft multi-layer plastic hose of the present invention has a wide range of applications, low cost and a very high market prospect.

[0155] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A soft multi-layer plastic hose, characterized in that: The soft multi-layer plastic hose has a five-layer structure, which includes an inner layer, a sub-inner layer, an intermediate layer, a sub-outer layer and an outer layer from the inside to the outside; the inner layer is polyethylene, the sub-inner layer is an adhesive, the intermediate layer is a barrier agent, the sub-outer layer is an adhesive, and the outer layer is a thermoplastic polyolefin and a high-density polyethylene in a mass ratio of 70:30; the multi-layer plastic hose is prepared by extrusion of a multi-layer co-extruder at different extrusion temperatures between different layers; The thickness of the soft multi-layer plastic hose is (0.5-0.55) ± 0.03 mm, the outer diameter of the soft multi-layer plastic hose is 40-50 mm; the glossiness of the soft multi-layer plastic hose is 12.2-12.8; the water vapor barrier property of the soft multi-layer plastic hose is 0.20-0.25%; the oxygen barrier property of the soft multi-layer plastic hose is 0.0631-0.0944 cm 3 / pkg•24h; under the tensile force of 100mm / min and 60N, the deformation of the soft multi-layer plastic hose is 80-88nm; after the end is sealed, the soft multi-layer plastic hose will not break under the pressure of 2bars; the outer surface of the soft multi-layer plastic hose is comfortable to touch and has fragrance retention; The thickness ratio of the inner layer, the sub-inner layer, the middle layer, the sub-outer layer and the outer layer is (0.28-0.32): 0.025: 0.025: 0.025: (0.15-0.16); The thermoplastic polyolefin has a melt index of 0.8 g / 10 min at 230° C. / 2.16 kg and a density of 0.89 g / cm 3 ; The high-density polyethylene has a melt index of 0.3-0.8 g / 10 min at 190°C / 2.16 kg and a density of 0.941-0.965 g / cm 3 ; The method for preparing the soft multi-layer plastic hose comprises the following steps: Step 1, adding polyethylene as an inner layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-inner layer into the multi-layer co-extruder, adding ethylene-vinyl alcohol copolymer as an intermediate layer into the multi-layer co-extruder, adding anhydride-modified linear low-density polyethylene as a sub-outer layer into the multi-layer co-extruder, adding thermoplastic polyolefin and high-density polyethylene as outer layers into the multi-layer co-extruder, and extruding to obtain a round tube embryo; Step 2, adding high-density polyethylene into a head injection machine, and transferring the circular tube blank to the head injection machine for head injection to obtain the soft multi-layer plastic hose; The inner layer extrusion temperature of the multilayer co-extruder in step 1 is 140-180°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 140°C, the temperature of the second temperature zone is 150°C, the temperature of the third temperature zone is 160°C, the temperature of the fourth temperature zone is 170°C and the temperature of the fifth temperature zone is 180°C; The extrusion temperature of the secondary inner layer of the multilayer co-extruder in step 1 is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C; The middle layer extrusion temperature of the multilayer co-extruder in step 1 is 200-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 200°C, the temperature of the second temperature zone is 210°C, the temperature of the third temperature zone is 215°C and the temperature of the fourth temperature zone is 220°C; The extrusion temperature of the secondary outer layer of the multilayer co-extruder in step 1 is 190-220°C, which is divided into 4 temperature zones, wherein the temperature of the first temperature zone is 190°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 210°C and the temperature of the fourth temperature zone is 220°C; The outer layer extrusion temperature of the multilayer co-extruder in step 1 is 180-200°C, which is divided into 5 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 190°C, the temperature of the third temperature zone is 200°C, the temperature of the fourth temperature zone is 200°C and the temperature of the fifth temperature zone is 200°C.

2. The flexible multi-layer plastic hose according to claim 1, characterized in that: The soft multi-layer plastic hose also includes a masterbatch, which is added into the multi-layer co-extrusion extruder as the inner layer raw material, and the mass ratio of the masterbatch to the polyethylene in the inner layer is (2-8):

100.

3. The flexible multi-layer plastic hose according to claim 1, characterized in that: The temperature of the die head of the multilayer co-extruder in step 1 is 190°C.

4. The flexible multi-layer plastic hose according to claim 1, characterized in that: The temperature of the injection head of the injection machine in step 2 is 180-320°C, which is divided into 7 temperature zones, wherein the temperature of the first temperature zone is 180°C, the temperature of the second temperature zone is 200°C, the temperature of the third temperature zone is 220°C, the temperature of the fourth temperature zone is 240°C, the temperature of the fifth temperature zone is 260°C, the temperature of the sixth temperature zone is 285°C and the temperature of the seventh temperature zone is 320°C.

5. A packaging hose, characterized in that: The packaging hose is the soft multi-layer plastic hose according to claim 1 or is prepared from the soft multi-layer plastic hose according to claim 1.

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