Environment-friendly hose for toothpaste packaging and preparation method thereof

Abstract

The invention discloses an environment-friendly hose for toothpaste packaging and a preparation method of the environment-friendly hose, and belongs to the technical field of packaging materials.The environment-friendly hose is characterized in that the environment-friendly hose comprises a base body and a PVA layer coating the base body, and the base body is prepared from, by weight, 60-80 parts of polyhydroxyalkanoate, 10-20 parts of plasticizer and 5-10 parts of filler; the effects that the toothpaste hose can be effectively degraded, pollution of the toothpaste hose to the environment is reduced, and it can be guaranteed that the toothpaste hose has enough mechanical strength and sealing performance in the using process can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of packaging materials, in particular to an environmentally friendly hose for toothpaste packaging and a preparation method thereof. Background Art

[0002] The packaging material widely used in the toothpaste industry is plastic hose. Although this type of material has good sealing and formability, it faces the problem of being difficult to recycle, and its non-degradable nature leads to the generation of a large amount of waste, causing serious environmental pollution. With the increase of global environmental awareness, seeking more environmentally friendly alternatives has become a top priority.

[0003] In recent years, research on biodegradable materials has gradually increased. Some studies have attempted to improve the degradability of plastics by adding natural ingredients such as starch, but this method reduces the durability and sealing of toothpaste tubes. Other studies have used biodegradable polymers such as polylactic acid to improve the degradability of toothpaste, but due to processing technology and formulation reasons, the toothpaste tubes produced often do not achieve ideal physical properties. It can be seen that the existing biodegradable materials still face problems such as insufficient strength and poor sealing performance in the application of toothpaste tubes. Summary of the invention

[0004] In order to solve the technical problems in the prior art, the present invention provides an environmentally friendly hose for toothpaste packaging and a preparation method thereof, which can ensure that the toothpaste hose is effectively degraded to reduce its pollution to the environment, and can also ensure that it has sufficient mechanical strength and sealing during use.

[0005] The first aspect of the present invention is to provide an environmentally friendly hose for toothpaste packaging, which adopts the following technical solution: An environmentally friendly hose for toothpaste packaging, comprising a substrate and a PVA layer coated on the substrate, wherein the substrate comprises the following raw materials in parts by weight: 60-80 parts of polyhydroxyalkanoate, 10-20 parts of plasticizer, and 5-10 parts of filler, wherein the filler is modified bamboo charcoal fiber, and the modification method thereof is as follows: S1. Prepare a polyvinyl alcohol solution with a concentration of 5-10 wt%, stir at 80-90° C. for 1-2 h until the polyvinyl alcohol powder is completely dissolved, and then cool to room temperature to obtain a polyvinyl alcohol solution; S2, immersing the bamboo charcoal fiber in the polyvinyl alcohol solution obtained in step S1 for 25-30 minutes; S3, putting the soaked material into an oven for drying to obtain modified bamboo charcoal fiber.

[0006] By adopting the above technical solution, after the polyhydroxyalkanoic acid ester is used in combination with a plasticizer and a filler, the filler can form a supporting structure in the polyhydroxyalkanoic acid ester matrix, which helps to disperse external forces and prevent the toothpaste hose from breaking or breaking when subjected to force. The addition of plasticizers effectively improves the mechanical strength of polyhydroxyalkanoic acid esters, and the use of polyhydroxyalkanoic acid esters also allows the toothpaste hose to be effectively degraded after use, thereby reducing pollution to the environment. Therefore, after the polyhydroxyalkanoic acid ester is used in combination with a plasticizer and a filler, the toothpaste hose obtained has good impact strength and degradation performance. The PVA layer coated on the hose substrate effectively improves the waterproof and moisture-proof performance of the toothpaste hose, avoiding the toothpaste in the hose from being affected, and the PVA layer can also be degraded in the natural environment, thereby not affecting the overall degradation performance of the toothpaste hose and reducing pollution to the environment. In addition, when the filler is made of modified bamboo charcoal fiber, the mechanical strength of the toothpaste hose can be effectively guaranteed, and at the same time, controlling the amount of bamboo charcoal fiber added can ensure that the toothpaste hose has good degradation performance.

[0007] In a preferred embodiment, the polyhydroxyalkanoate is 70-75 parts by weight.

[0008] In a preferred embodiment, the polyhydroxyalkanoate is poly 3-hydroxybutyrate-co-4-hydroxybutyrate.

[0009] In a preferred embodiment, the content of 4-hydroxybutyrate in the poly 3-hydroxybutyrate-co-4-hydroxybutyrate is 21 wt %, the Mn of the poly 3-hydroxybutyrate-co-4-hydroxybutyrate is 130,000, and the Mw / Mn is 1.23.

[0010] By adopting the above technical scheme, the polyhydroxyalkanoic acid ester adopts poly 3-hydroxybutyric acid-co-4-hydroxybutyrate and the content of 4-hydroxybutyrate is 21wt%, the Mn of poly 3-hydroxybutyric acid-co-4-hydroxybutyrate is 130000, and the Mw / Mn is 1.23. The mechanical properties and degradation properties of the toothpaste tube can be effectively balanced, so that the toothpaste tube can be degraded in a composting environment after use, and at the same time, it can also ensure that the toothpaste tube can withstand daily squeezing and stretching during use.

[0011] In a preferred embodiment, the plasticizer is a citrate plasticizer.

[0012] By adopting the above technical scheme, when a citrate plasticizer is selected as the plasticizer in the present application, it can effectively reduce the glass transition temperature of poly 3-hydroxybutyric acid-co-4-hydroxybutyrate, so that it can also show good flexibility and ductility at a lower temperature. At the same time, the citrate plasticizer has good compatibility with poly 3-hydroxybutyric acid-co-4-hydroxybutyrate and can be evenly dispersed in poly 3-hydroxybutyric acid-co-4-hydroxybutyrate to ensure the uniformity of the plasticizing effect. At the same time, the citrate plasticizer can also improve the fluidity of poly 3-hydroxybutyric acid-co-4-hydroxybutyrate during processing, thereby improving production efficiency and reducing energy consumption during processing.

[0013] In a preferred embodiment, the average particle size of the bamboo charcoal fibers is 5-10 μm.

[0014] By adopting the above-mentioned technical scheme, the present application controls the average particle size of the bamboo charcoal fiber to be between 5-10 μm and after the bamboo charcoal fiber is modified with polyvinyl alcohol, it can effectively ensure that the bamboo charcoal fiber is evenly dispersed in poly 3-hydroxybutyric acid-co-4-hydroxybutyrate, thereby effectively ensuring the uniformity of the mechanical properties of the toothpaste tube.

[0015] In a preferred embodiment, the thickness of the PVA layer is 10-15 μm.

[0016] By adopting the above technical solution, when the thickness of the PVA layer is controlled between 10-15μm, the flexibility of the toothpaste can be guaranteed while the good waterproof performance of the toothpaste hose can be guaranteed. If the thickness of the PVA layer is too thick, it will affect the softness of the toothpaste hose, while if it is too thin, it will not be enough to provide sufficient waterproof and moisture-proof protection.

[0017] The second aspect of the present invention is to provide a method for preparing the above-mentioned environmentally friendly hose for toothpaste packaging, comprising the following preparation steps: (1) Mix polyhydroxyalkanoate and plasticizer evenly and add them into a twin-screw extruder for later use; (2) The filler is placed at the side feed port of the twin-screw extruder and mixed with the mixture obtained in step (1), melt-extruded and formed, and then cooled and shaped to obtain a preliminary finished product. A PVA layer is coated on the surface of the preliminary finished product, and then cut and sealed to obtain a hose.

[0018] In summary, the present invention has the following beneficial effects: 1. In the present application, the use of polyhydroxyalkanoates in combination with plasticizers and fillers effectively improves the flexibility and mechanical strength of polyhydroxyalkanoates. At the same time, the use of polyhydroxyalkanoates also allows the toothpaste hose to be degraded in a composting environment after use, thereby reducing environmental pollution. The PVA layer coated on the hose substrate effectively improves the waterproof and moisture-proof properties of the hose, preventing the toothpaste in the hose from being affected, and the PVA layer can also be degraded in the natural environment, thereby not affecting the overall degradation performance of the toothpaste hose and reducing pollution to the environment.

[0019] 2. The selection of polyhydroxyalkanoate type balances the degradation performance and mechanical properties of the toothpaste tube, ensuring the use effect of the tube. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below with reference to the examples. All reagents without manufacturer indicated are conventional reagent products that can be obtained commercially.

[0021] Preparation Example 1 The modification method of bamboo charcoal fiber comprises the following steps: S1, preparing a polyvinyl alcohol aqueous solution with a concentration of 5 wt%, stirring at 80° C. for 2 h until the polyvinyl alcohol powder is completely dissolved, and then cooling to room temperature to obtain a polyvinyl alcohol solution; S2, completely immersing the bamboo charcoal fibers with an average particle size of 5-10 μm in the polyvinyl alcohol solution obtained in step S1 for 25-30 minutes; S3, putting the soaked material into an oven and drying it at 60° C. for 4 h to obtain modified bamboo charcoal fiber.

[0022] Preparation Example 2 The modification method of bamboo charcoal fiber comprises the following steps: S1, preparing a polyvinyl alcohol aqueous solution with a concentration of 10 wt%, stirring at 90° C. for 1 h until the polyvinyl alcohol powder is completely dissolved, and then cooling to room temperature to obtain a polyvinyl alcohol solution; S2, completely immersing the bamboo charcoal fibers with an average particle size of 5-10 μm in the polyvinyl alcohol solution obtained in step S1 for 25-30 minutes; S3, putting the soaked material into an oven and drying it at 80°C for 2h to obtain modified bamboo charcoal fiber.

[0023] Example 1

[0024] A method for preparing an environmentally friendly hose for toothpaste packaging, comprising the following preparation steps: (1) 6 kg of polyhydroxyalkanoate and 1 kg of tributyl citrate plasticizer were mixed evenly and added into a twin-screw extruder for standby use; wherein the polyhydroxyalkanoate was poly-3-hydroxybutyric acid-co-4-hydroxybutyrate, with an Mn of 130,000 and an Mw / Mn of 1.23, and the content of 4-hydroxybutyrate in the poly-3-hydroxybutyric acid-co-4-hydroxybutyrate was 21 wt%; (2) 0.5 kg of the modified bamboo charcoal fiber obtained in Preparation Example 1 is placed in the side feed port of a twin-screw extruder and mixed with the mixture obtained in step (1), and melt-extruded to form the fiber. The barrel temperatures of the extruder are 160° C., 165° C., 170° C., 170° C., 165° C., and 165° C., respectively. The fiber is cooled and shaped to obtain a pre-finished product. A PVA layer with a thickness of 10 μm is coated on the surface of the pre-finished product, and the pre-finished product is cut and sealed to obtain a hose.

[0025] Example 2

[0026] A method for preparing an environmentally friendly hose for toothpaste packaging, comprising the following preparation steps: (1) 7 kg of polyhydroxyalkanoate and 1.2 kg of tributyl citrate plasticizer were mixed evenly and added into a twin-screw extruder for standby use; wherein the polyhydroxyalkanoate was poly-3-hydroxybutyric acid-co-4-hydroxybutyrate, with an Mn of 130,000 and an Mw / Mn of 1.23, and the content of 4-hydroxybutyrate in the poly-3-hydroxybutyric acid-co-4-hydroxybutyrate was 21 wt%; (2) 0.7 kg of modified bamboo charcoal fiber obtained in Preparation Example 1 is placed in the side feed port of a twin-screw extruder and mixed with the mixture obtained in step (1), and melt-extruded to form the fiber. The barrel temperatures of the extruder are 160° C., 165° C., 170° C., 170° C., 165° C., and 165° C., respectively. The fiber is cooled and shaped to obtain a pre-finished product. A PVA layer with a thickness of 10 μm is coated on the surface of the pre-finished product, and the pre-finished product is cut and sealed to obtain a hose.

[0027] Example 3

[0028] A method for preparing an environmentally friendly hose for toothpaste packaging, comprising the following preparation steps: (1) 7.5 kg of polyhydroxyalkanoate and 1.5 kg of tributyl citrate plasticizer were mixed evenly and added into a twin-screw extruder for standby use; wherein the polyhydroxyalkanoate was poly-3-hydroxybutyric acid-co-4-hydroxybutyrate, with Mn of 130,000 and Mw / Mn of 1.23, and the content of 4-hydroxybutyrate in the poly-3-hydroxybutyric acid-co-4-hydroxybutyrate was 21 wt%; (2) 1.0 kg of modified bamboo charcoal fiber obtained in Preparation Example 1 is placed in the side feed port of a twin-screw extruder and mixed with the mixture obtained in step (1), and melt-extruded to form the fiber. The barrel temperatures of the extruder are 160° C., 165° C., 170° C., 170° C., 165° C., and 165° C., respectively. The fiber is cooled and shaped to obtain a pre-finished product. A PVA layer with a thickness of 10 μm is coated on the surface of the pre-finished product, and the pre-finished product is cut and sealed to obtain a hose.

[0029] Example 4

[0030] A method for preparing an environmentally friendly hose for toothpaste packaging, comprising the following preparation steps: (1) 8.0 kg of polyhydroxyalkanoate and 2.0 kg of tributyl citrate plasticizer were mixed evenly and added into a twin-screw extruder for standby use; wherein the polyhydroxyalkanoate was poly-3-hydroxybutyric acid-co-4-hydroxybutyrate, with Mn of 130,000 and Mw / Mn of 1.23, and the content of 4-hydroxybutyrate in the poly-3-hydroxybutyric acid-co-4-hydroxybutyrate was 21 wt%; (2) 1.0 kg of modified bamboo charcoal fiber obtained in Preparation Example 1 is placed in the side feed port of a twin-screw extruder and mixed with the mixture obtained in step (1), and melt-extruded to form the fiber. The barrel temperatures of the extruder are 160° C., 165° C., 170° C., 170° C., 165° C., and 165° C., respectively. The fiber is cooled and shaped to obtain a pre-finished product. A PVA layer with a thickness of 10 μm is coated on the surface of the pre-finished product, and the pre-finished product is cut and sealed to obtain a hose.

[0031] Example 5

[0032] A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the modified bamboo charcoal fiber adopts the modified bamboo charcoal fiber obtained in Preparation Example 2, and the rest is the same as Example 3.

[0033] Example 6

[0034] A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the thickness of the PVA coating is 15 microns, and the rest is the same as Example 3.

[0035] Example 7

[0036] A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the polyhydroxyalkanoic acid ester uses poly 3-hydroxybutyric acid-co-4-hydroxybutyrate, Mn is 130,000, Mw / Mn is 1.23, and the content of 4-hydroxybutyrate in poly 3-hydroxybutyric acid-co-4-hydroxybutyrate is 5wt%, and the rest is the same as Example 3.

[0037] Example 8

[0038] A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the polyhydroxyalkanoate uses poly 3-hydroxybutyrate, Mn is 330000, Mw / Mn is 2.5, and the extruder barrel temperature during melt extrusion is 175°C, 185°C, 185°C, 180°C, 180°C, and 180°C, respectively, and the rest is the same as Example 3.

[0039] Example 9

[0040] A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the bamboo charcoal fiber uses unmodified bamboo charcoal fiber, and the rest is the same as Example 3.

[0041] Comparative Example 1 A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the polyhydroxyalkanoate is 8.5 kg, the plasticizer is 2 kg, and the modified bamboo charcoal fiber obtained in Preparation Example 1 is 1 kg, and the rest is the same as Example 3.

[0042] Comparative Example 2 A method for preparing an environmentally friendly hose for toothpaste packaging, which is different from Example 3 in that the polyhydroxyalkanoate is 7.5 kg, the plasticizer is 2 kg, and the modified bamboo charcoal fiber obtained in Preparation Example 1 is 1.5 kg, and the rest is the same as Example 3.

[0043] Performance Testing The toothpaste tubes obtained in the above examples and comparative examples were tested for flexibility, impact performance, sealing performance, water vapor barrier performance and degradation performance. The test results are shown in Table 1.

[0044] For the sealing performance, the toothpaste tube is stored at room temperature for one year and then checked for leakage under a pressure of 0.1MPa; for the degradation performance, refer to GB / T19277.1-2011, and carry out composting degradation test on the material. The sample material is mixed with the compost inoculum and placed in a composting container. A full composting test is carried out in an oxygenated environment, at a temperature of 58±2℃ and a humidity of 50-55%, and the biodegradation rate within 6 months is calculated; the water vapor barrier property is tested by using a water vapor permeability tester in accordance with GB / T1037-2021 standard to test the water vapor barrier property of the toothpaste tube, and the ability of the toothpaste tube to block water vapor is determined by measuring the amount of water vapor passing through the tube within 48 hours.

[0045] Table 1 Toothpaste tube performance test results project Elongation at break % <![CDATA[Impact strength KJ / m 2 > Airtightness <![CDATA[Water vapor transmission rate g / m 2 ·24h]]> Degradation rate% Example 1 124 7.2 no 0.05 78.5 Example 2 130 7.3 no 0.05 78.6 Example 3 134 7.8 no 0.04 78.4 Example 4 135 8.0 no 0.05 78.5 Example 5 133 7.9 no 0.04 78.6 Example 6 132 8.0 no 0.02 77.9 Example 7 86 4.6 no 0.05 69.8 Example 8 78 3.7 no 0.08 68.2 Example 9 115 6.8 no 0.10 78.7 Comparative Example 1 102 6.6 no 0.12 79.1 Comparative Example 2 95 5.7 no 0.11 78.8 From Table 1 we can see that: The elongation at break of the toothpaste tubes obtained in Examples 1-6 of the present application is all above 120%, and the impact strength is 7KJ / m2 Above, water vapor transmission rate is ≤0.05g / m 2 ·24h, the degradation rate is above 78%, and the toothpaste hose is placed indoors for one year and still does not leak under a pressure of 0.1MPa, indicating that the toothpaste hoses obtained in Examples 1-6 of the present application have good sealing performance and flexibility, while maintaining a good degradation rate, meeting environmental protection requirements.

[0046] Compared with Example 3, the difference between Example 7-8 is that the content of 4-hydroxybutyrate in poly 3-hydroxybutyrate-co-4-hydroxybutyrate is only 5% or after the polyhydroxyalkanoate adopts poly 3-hydroxybutyrate, the elongation at break and impact strength of the toothpaste tube obtained in Example 7-8 are significantly reduced, indicating that the material obtained in Example 7-8 has high brittleness and poor flexibility. In addition, the degradation rate of the toothpaste tube obtained in Example 7-8 is also significantly reduced compared with that in Example 3. It can be seen that the choice of polyhydroxyalkanoate will not only affect the flexibility of the toothpaste tube, but also affect the degradation rate of the toothpaste tube.

[0047] Compared with Example 3, after the bamboo charcoal fiber uses unmodified bamboo charcoal fiber, the dispersion performance of the bamboo charcoal fiber in polyhydroxyalkanoate is relatively poor, resulting in further reduction of the elongation at break and impact strength of the toothpaste tube obtained in Example 9. This shows that after the bamboo charcoal fiber is modified with polyvinyl alcohol in the present application, the compatibility of the bamboo charcoal fiber and polyhydroxyalkanoate is improved, which helps to improve the flexibility of the toothpaste tube without affecting the degradation performance of the toothpaste tube.

[0048] Compared with Example 3, when the content of polyhydroxyalkanoic acid ester or the content of modified bamboo charcoal fiber exceeds the limit of the present application, the elongation at break and the impact strength of the toothpaste hose obtained in Comparative Example 1-2 are lower than those in Example 3. The reason may be that the addition of excessive polyhydroxyalkanoic acid ester or bamboo charcoal fiber does not further improve the flexibility of the toothpaste hose. On the contrary, the hardness of the toothpaste hose increases due to the addition of excessive polyhydroxyalkanoic acid ester or bamboo charcoal fiber, making the toothpaste hose more brittle and more prone to cracking. Therefore, when the addition amount of polyhydroxyalkanoic acid ester and bamboo charcoal fiber is controlled within the scope of the present application, not only the degradation performance of the toothpaste hose can be guaranteed, but also the toothpaste hose can have good flexibility, thereby ensuring the service life of the toothpaste hose.

[0049] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An environmentally friendly hose for toothpaste packaging, characterized by: The environmentally friendly hose comprises a substrate and a PVA layer coated on the substrate, wherein the substrate comprises the following raw materials in parts by weight: 60-80 parts of polyhydroxyalkanoate, 10-20 parts of plasticizer, and 5-10 parts of filler; the filler is modified bamboo charcoal fiber, and the modification method thereof is as follows: S1. Prepare a polyvinyl alcohol solution with a concentration of 5-10 wt%, stir at 80-90° C. for 1-2 h until the polyvinyl alcohol powder is completely dissolved, and then cool to room temperature to obtain a polyvinyl alcohol solution; S2, immersing the bamboo charcoal fiber in the polyvinyl alcohol solution obtained in step S1 for 25-30 minutes; S3, putting the soaked material into an oven for drying to obtain modified bamboo charcoal fiber.

2. The environmentally friendly hose for toothpaste packaging according to claim 1, characterized in that: The polyhydroxyalkanoate is 70-75 parts by weight.

3. The environmentally friendly hose for toothpaste packaging according to claim 1, characterized in that: The polyhydroxyalkanoate is poly-3-hydroxybutyric acid-co-4-hydroxybutyrate.

4. The environmentally friendly hose for toothpaste packaging according to claim 3, characterized in that: The content of 4-hydroxybutyrate in the poly 3-hydroxybutyrate-co-4-hydroxybutyrate is 21 wt %, the Mn of the poly 3-hydroxybutyrate-co-4-hydroxybutyrate is 130,000, and the Mw / Mn is 1.

23.

5. The environmentally friendly hose for toothpaste packaging according to claim 1, characterized in that: The plasticizer is a citrate plasticizer.

6. The environmentally friendly hose for toothpaste packaging according to claim 1, characterized in that: The average particle size of the bamboo charcoal fiber is 5-10 μm.

7. The environmentally friendly hose for toothpaste packaging according to claim 1, characterized in that: The thickness of the PVA layer is 10-15 μm.

8. A method for preparing an environmentally friendly hose for toothpaste packaging according to any one of claims 1 to 7, characterized in that: The method comprises the following preparation steps: The polyhydroxyalkanoate and the plasticizer are mixed evenly and added into a twin-screw extruder for later use; The filler is then placed at the side feed port of the twin-screw extruder and mixed with the mixture obtained in step (1), melt-extruded and formed, and then cooled and shaped to obtain a preliminary finished product. A PVA layer is coated on the surface of the preliminary finished product, and then cut and sealed to obtain a hose.