An air-cushion film, barrier paper air-cushion, and methods of making the same

Abstract

The present application relates to air cushion film technical field, especially in kind of air cushion film, barrier paper air cushion and their preparation method, the air cushion film includes outer layer, middle layer and inner layer, the component of outer layer includes modified plastic particle that surface is wrapped with talcum powder, the component of modified plastic particle includes PPC, PBAT and molecular entanglement agent, the component of middle layer and inner layer all contains PBAT, the air cushion film that the present application provides, not only has biodegradable function has the barrier gas preservation effect that is no less than nylon, in the compound with paper adapts new production process, greatly improves production efficiency, reduces material and paper coating or the process of showering film, reduces production cost and carbon emission.

Description

Technical Field

[0001] This invention relates to the field of air cushion film technology, and particularly to an air cushion film, a barrier paper air cushion, and a method for preparing them. Background Technology

[0002] Currently, barrier paper air cushion products mainly use PE (polyethylene) / PA (polyamide) materials, which are bonded to kraft paper with adhesive. This structure gives the product good gas barrier and puncture resistance, ensuring the stability and protective effect of the air cushion during packaging and transportation. However, the large differences in compatibility and processing temperature between PE and PA materials make them difficult to recycle after disposal and they are not biodegradable, thus causing serious environmental pollution problems.

[0003] Most of the biodegradable materials on the market are modifications of PBAT (polyethylene terephthalate-co-caprolactone). Although they achieve biodegradability, their barrier properties are far inferior to those of PE / PA materials, and they cannot meet the requirements for barrier and gas retention. Summary of the Invention

[0004] To address the challenge of simultaneously achieving biodegradability and air-retaining properties in existing barrier paper air cushion products, this invention provides an air cushion film, a barrier paper air cushion, and a method for preparing them.

[0005] To address the aforementioned technical problems, one of the technical solutions provided by this invention is as follows:

[0006] An air cushion film, the air cushion film comprising an outer layer, a middle layer and an inner layer;

[0007] The outer layer comprises modified plastic particles coated with talc, and the modified plastic particles comprise PPC, PBAT and a molecular winding agent.

[0008] Both the middle and inner layers contain PBAT.

[0009] In one embodiment, the components of the modified plastic particles with talc-coated surfaces include:

[0010] 50.0% to 80.0% by weight of PPC;

[0011] 15.0% to 50.0% by weight of PBAT;

[0012] 2.0% to 5.0% by weight of molecular winding agent;

[0013] 1.0% to 2.0% by weight of talc.

[0014] In one embodiment, the talc powder has a particle size of 2500 mesh or larger.

[0015] In one embodiment, the components of the middle layer include PBAT, PLA, activated calcium carbonate, molecular winding agent, and calcium stearate.

[0016] In one embodiment, the components of the middle layer include:

[0017] 50.0% to 65.0% by weight of PBAT;

[0018] PLA from 8.0% to 15.0% by weight;

[0019] 25.0% to 35.0% by weight of activated calcium carbonate;

[0020] 2.0% to 5.0% by weight of molecular winding agent;

[0021] 0.3% to 0.5% by weight of calcium stearate.

[0022] In one embodiment, the components of the inner layer include PBAT, PBST, and a slip agent.

[0023] In one embodiment, the components of the inner layer include:

[0024] 49.95% to 65.0% by weight of PBAT;

[0025] 34.8% to 50.0% PBST;

[0026] 0.05% to 0.2% by weight of a slip agent.

[0027] The PBAT used in the inner layer has a melt index of less than 5 g / 10 min, wherein the test method for the melt index is GB / T3682, and the test conditions are 190℃ and 2.16 kg.

[0028] The PBST used in the inner layer has a melt index of less than 5 g / 10 min. The melt index is tested according to GB / T3682, and the test conditions are 190℃ and 2.16 kg.

[0029] The second technical solution provided by this invention is as follows:

[0030] A method for preparing an air cushion film includes the following steps:

[0031] The system provides an outer layer component, a middle layer component, and an inner layer component. The outer layer component includes modified plastic particles coated with talc powder. The modified plastic particles are composed of PPC, PBAT, and a molecular winding agent.

[0032] The outer layer component, middle layer component and inner layer component are co-extruded and blown into a film to form a thin film.

[0033] The third technical solution provided by this invention is as follows:

[0034] A barrier paper air cushion, the barrier paper air cushion comprising an upper protective layer, an air cushion layer and a lower protective layer;

[0035] The air cushion layer uses the air cushion film described above;

[0036] The upper and lower protective layers are made of kraft paper.

[0037] The fourth technical solution provided by this invention is as follows:

[0038] The method for preparing the barrier paper air cushion as described above includes the following steps:

[0039] The upper protective layer, air cushion layer, and lower protective layer are stacked in a top-to-bottom order and pressed together using heated rollers.

[0040] Based on the above, compared with the prior art, the air cushion film provided by the present invention not only has biodegradability but also has a barrier and air retention effect that is no less than that of nylon.

[0041] Other features and beneficial effects of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other beneficial effects of the invention can be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0043] Figure 1 A schematic diagram illustrating the bag-making process of upper and lower kraft paper and tubular film provided by the present invention;

[0044] Figure 2 This is a schematic diagram of the paper air cushion being rolled before winding, as provided by the present invention.

[0045] Figure 3 A photograph of the finished barrier paper air cushion provided in an embodiment of the present invention;

[0046] Figure 4Photograph of the finished barrier paper air cushion provided in another embodiment of the present invention. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] In the description of this invention, it should be noted that all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and should not be construed as limiting the invention; it should be further understood that the terms used in this invention should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this invention.

[0049] The air cushion film provided by this invention not only possesses excellent biodegradability but also rivals nylon materials in its air-barrier and retention performance. Furthermore, when laminated with paper, this air cushion film can be used in a novel hot-pressing production process, significantly improving production efficiency and greatly reducing the number of processes involved in laminating or coating the material with paper. This effectively lowers production costs and carbon emissions, achieving a win-win situation for both environmental protection and economic efficiency.

[0050] This invention provides an air cushion film, which includes an outer layer, a middle layer, and an inner layer;

[0051] The outer layer comprises modified plastic particles coated with talc, and the modified plastic particles comprise PPC, PBAT and a molecular winding agent.

[0052] Both the middle and inner layers contain PBAT.

[0053] Specifically, the use of the above components and structure as the outer layer of the air cushion film in this invention has at least the following three functions:

[0054] Firstly, the oxygen permeability of PBAT material is approximately 1500 cm⁻¹. 3 / m 2 The pressure of 0.1 MPa over 24 hours does not provide good barrier properties. Therefore, this invention introduces PPC material, whose oxygen permeability is approximately 20-30 cm³. 3 / m 2 A pressure of 0.1 MPa for 24 hours gives the outer layer material significant gas barrier properties. However, in existing technologies, to improve the compatibility of PPC and PBAT and minimize the impact of PBAT on the oxygen barrier properties of PPC, compatibilizers or chain extenders are generally added. Commercially available compatibilizers are mostly grafted with maleic anhydride using PBAT as a base material, resulting in generally poor compatibility and requiring large amounts, which further affects the barrier properties of the PPC material. While chain extenders require small amounts and can increase the molecular weight of the material, meeting design requirements, their presence can easily lead to excessive local polymerization, resulting in crystal particles and micropore leakage. Therefore, based on the above, the inventors discovered that using a molecular winding agent can effectively solve these problems.

[0055] The main component of the molecular winding agent used in this invention is a high-molecular-weight acrylate copolymer. Through physical winding, the molecular chains of different materials are bound together like yarn, achieving both compatibility and solving the problem of crystal point leakage caused by localized over-polymerization during the polymerization reaction. To ensure good dispersion of the long chains of the high-molecular-weight acrylate copolymer, a core-shell structure is formed on the surface of the copolymer, allowing it to be uniformly dispersed throughout the material during modification. Specifically, this can be achieved by using materials such as PVDC, SAN, and PAN to disperse the oil phase mixture into tiny oil droplets through mechanical stirring or ultrasonic methods, forming stable water-in-oil (W / O) or oil-in-water (O / W) emulsions. Under certain conditions (such as heating, light, or radiation), an initiator initiates the polymerization reaction of the monomers in the oil droplets, forming high-molecular-weight chains. As the polymerization reaction proceeds, the high-molecular-weight chains gradually deposit on the surface of the oil droplets, forming a dense shell layer.

[0056] Secondly, the PPC material used in this invention has a softening temperature of around 30°C and has a certain degree of stickiness at room temperature. In conventional film production, this characteristic would seriously affect its use and is a major drawback of the material. Based on this drawback, the inventors discovered that when the material is used for the outer layer, it can be used to bond kraft paper, thus creatively proposing a brand-new paper air cushion production process.

[0057] Specifically, the steps of this production process are as follows:

[0058] Step 1: Referring to Figure 1, place the kraft paper on the upper and lower material racks, and place the biodegradable tubular film (made from the air cushion film provided by this invention) between the upper and lower kraft papers. The color and whether the kraft paper is glossy are not limited, and the weight is between 12-80g. If the thickness is too thin, the strength of the kraft paper will be poor, and it will be easy to wrinkle during bag making. If the thickness is too thick, the heat conduction during bag making will be poor, and the heat sealing effect of the film will be worse.

[0059] Step 2: The thickness of the biodegradable tubular film should be 1C-7C. If the thickness is too thin, the film strength will be inaccurate and it will be easy to wrinkle during bag making. If the thickness is too thick, the heat sealing effect between the film and the bottom kraft paper will be poor during bag making.

[0060] Step 3: After starting the machine, guide the three layers of material through the guide rollers and draw them under the bag-making mold. The surface of the bag-making mold has raised patterns printed with structures such as gourd balls, squares, and rows. Heat the mold to 120-260℃ and hot-press the three-layer structure.

[0061] Step 4: The mold temperature is conducted from top to bottom, sequentially through the upper kraft paper to the biodegradable membrane and then the lower kraft paper. Under the influence of temperature, the upper kraft paper and the biodegradable membrane, and the biodegradable membrane and the lower kraft paper, bond together, making the three-layer structure a whole.

[0062] Step 5: Using a toothed knife, imprint intermittent tooth marks on the surface of the heat-sealed three-layer structure. This makes it easier to tear it apart into individual pieces for later use.

[0063] Step 6: Finally, roll it up into a roll. When using it, inflate and heat-seal it through the reserved air channel to expand it for use.

[0064] Under the heat-sealing mold, the three-layer structure bonds the upper and lower kraft paper together with the biodegradable film along the heat seal line, eliminating the need for laminating paper and adhesive, and offering better strength than the coating process. However, a drawback of this process is that the film and kraft paper separate at the heat-sealing line. To address this, this invention utilizes the low softening point of PPC, adjusting the ratio of PPC to PBAT materials to control the softening point of the outer layer at 60-80℃. This prevents film sticking during blown film production and, on the other hand, [further details needed]. Figure 2 As shown, before the bag is rolled up, upper and lower heating steel wheels are added, with a heating temperature of 120-140℃. By rolling and heating the finished product, the surface material of the film softens and becomes sticky, thus adhering to the surface kraft paper.

[0065] Traditional paper air cushion products are manufactured in two ways: one is to coat kraft paper with a biodegradable material, then use the coated material to make bags; the other is to bond kraft paper and a biodegradable film together with adhesive, then use this coated paper to make bags. The coating process typically involves temperatures above 260℃, which can easily cause the biodegradable material to degrade, and the film lacks lateral stretching, resulting in poor orientation properties. While the performance of the coated material can meet the requirements, it requires high film flatness, has a complex manufacturing process, a high scrap rate, and the adhesive used is non-biodegradable.

[0066] Third, although pure PPC material has better barrier properties, it is prone to delamination from the middle layer material. Therefore, adding an appropriate proportion of PBAT to the outer layer can not only control the softening point of the outer layer, but the presence of PBAT can also make it easier for the outer layer and the middle layer material to form a tight bond, thus avoiding delamination.

[0067] Furthermore, in preparing the outer layer, this invention specifically adds talc powder after granulation, allowing it to coat the surface of the modified plastic granules. This is because talc powder, due to its unique lamellar structure, provides a slippery effect. Modified PPC, due to its high temperature during granulation, is prone to clumping. Therefore, adding a small amount of talc powder to the granule surface after granulation prevents the material from agglomerating. Simultaneously, testing revealed that the lamellar structure of talc powder does not affect the barrier properties of PPC material, while materials such as calcium carbonate and sodium sulfate do affect the barrier properties and are prone to producing crystalline particles.

[0068] In some preferred embodiments, the modified plastic particles with talc coating comprise: 50.0% to 80.0% by weight of PPC; 15.0% to 50.0% by weight of PBAT; 2.0% to 5.0% by weight of molecular winding agent; and 1.0% to 2.0% by weight of talc.

[0069] In a preferred embodiment, the PBAT used in the outer layer has a melt index of less than 5 g / 10 min, wherein the melt index is tested according to GB / T3682, and the test conditions are 190°C and 2.16 kg; the PBAT used in the outer layer has a melting point of 115-123°C and a heat distortion temperature of more than 55°C.

[0070] In a preferred embodiment, the PPC used in the outer layer has a melt flow index of less than 3 g / 10 min, wherein the melt flow index is tested according to GB / T3682, and the test conditions are 170°C and 2.16 kg; the PPC used in the outer layer has a thermal decomposition temperature of more than 200°C and a glass transition temperature of more than 23°C.

[0071] In some preferred embodiments, the talc powder has a particle size of 2500 mesh or larger. Preferably, the talc powder may be activated with a silane coupling agent.

[0072] This invention provides a method for preparing the modified outer layer component, comprising the following steps:

[0073] Step 1: Add PPC, PBAT, and molecular winding agent into a high-speed mixer in a certain proportion. The stirring frequency is 20-25Hz and the stirring time is 3-5 minutes.

[0074] It should be noted that the high-speed mixer should not be heated in this step. Preferably, circulating cooling water can be used to keep the temperature below 35°C.

[0075] Step 2: After the mixture is well stirred, pour it into the hopper of the twin-screw modifier.

[0076] The temperature settings for the modification machine are shown in the table below:

[0077] Table 1

[0078]

[0079]

[0080] The modified tie rods are air-cooled to prevent the material from absorbing water.

[0081] Step 3: After pelleting, the pellets are fed into a mixing hopper. It is preferable to preheat a certain proportion of talc powder in the mixing hopper and stir while pelleting to coat the surface of the pellets with talc powder, so as to prevent the pellets from sticking together.

[0082] Step 4: After mixing and stirring, pack into bags.

[0083] In some preferred embodiments, the middle layer comprises PBAT, PLA, activated calcium carbonate, molecular winding agent, and calcium stearate.

[0084] The main function of this middle layer is to provide stiffness to the air cushion film and to provide heat resistance for heat sealing during bag making. In order to ensure that the film has good flatness during bag making, the film needs a certain degree of stiffness. PLA material is added to this middle layer mainly to improve the hardness of the material, so that the film is not easy to wrinkle or deform during tensile traction.

[0085] Adding activated calcium carbonate effectively improves the heat resistance of the material, creating a temperature difference between the middle and inner layers to ensure the middle layer does not crack due to heat during heat sealing when the inner layer softens. Simultaneously, adding calcium stearate not only promotes the dispersion of calcium carbonate materials and reduces thermal degradation of biodegradable materials during blown film heating, but also increases the crystallinity of PLA and PBAT materials during cooling, thereby improving the material's hardness. Utilizing the principle of physical entanglement, PBAT molecular chains are wound together using a molecular entanglement agent.

[0086] In some preferred embodiments, the components of the middle layer include:

[0087] 50.0% to 65.0% by weight of PBAT; 8.0% to 15.0% by weight of PLA; 25.0% to 35.0% by weight of activated calcium carbonate; 2.0% to 5.0% by weight of molecular winding agent; 0.3% to 0.5% by weight of calcium stearate.

[0088] In a preferred embodiment, the PBAT used in the middle layer has a melt index of less than 5 g / 10 min, wherein the melt index is tested using GB / T3682 and the test conditions are 190°C and 2.16 kg.

[0089] In a preferred embodiment, the PLA used in the middle layer has a melt index of less than 5 g / 10 min, wherein the melt index is tested according to GB / T3682, and the test conditions are 90°C and 2.16 kg.

[0090] This invention provides a method for preparing the modified middle layer component, comprising the following steps:

[0091] Step 1: Add PLA, PBAT, molecular winding agent, calcium carbonate, and calcium stearate into a high-speed mixer in a certain proportion. Set the temperature to 80-85℃, the stirring frequency to 20-25Hz, and the stirring time to 5-10min.

[0092] Step 2: After the mixture is stirred, pour it into the hopper of the twin-screw modifier.

[0093] The temperature settings for the modification machine are shown in the table below:

[0094] Table 2

[0095] Feeding section Heating section 1 Heating section 2 Heating section 3 Compression segment 4 100℃ 120-130℃ 130-140℃ 130-140℃ 130-140℃ Heating section 5 Heating section 6 Extrusion section mold head Heating section 5 130-140℃ 130-140℃ 130-140℃ 130-140℃ 130-140℃

[0096] Among them, the modified tie rod is air-cooled to prevent the material from absorbing water;

[0097] Step 3: After cutting into pellets, pack them into bags.

[0098] In some preferred embodiments, the components of the inner layer include PBAT, PBST, and a slip agent.

[0099] Compared to the middle layer, the inner layer requires a lower softening point and better heat-sealing performance; therefore, no fillers are added to the components of this inner layer. Furthermore, at the production winding point, to ensure adhesion between the kraft paper and the film surface, the material needs to be rolled by steel wheels at 120-140℃. To ensure the surface layer softens while the inner layer remains unaffected, the inner layer needs a higher softening temperature. Since PLA easily affects the final heat-sealing properties of the material, it is generally considered to add PLA. However, PLA and PBAT have poor compatibility and require modification to improve compatibility and dispersibility. Based on this, this invention provides a new approach: a blown film method that mixes PBAT and PBST together. This not only eliminates the material modification operation and associated costs but also improves the heat-sealing and heat-resistant performance of the inner layer. This is because PBAT and PBST have good compatibility, and PBST has higher rigidity and melting point temperature than PBAT, providing the inner layer with better heat-sealing strength and heat resistance.

[0100] In some preferred embodiments, the components of the inner layer include:

[0101] 49.95% to 65.0% by weight of PBAT; 34.8% to 50.0% by weight of PBST; 0.05% to 0.2% by weight of slip agent.

[0102] In a preferred embodiment, the PBAT used in the inner layer has a melt index of less than 5 g / 10 min, wherein the melt index is tested using GB / T3682 and the test conditions are 190°C and 2.16 kg.

[0103] In a preferred embodiment, the PBST used in the inner layer has a melt index of less than 5 g / 10 min, wherein the melt index is tested according to GB / T3682, and the test conditions are 190°C and 2.16 kg.

[0104] In a preferred embodiment, the slip agent is a mesoamide.

[0105] This invention provides a method for preparing the modified inner layer component, comprising the following steps:

[0106] Step 1: Add PBST, PBAT, and slip agent to a high-speed mixer in a certain proportion. No heating is required. The stirring frequency is 20-25Hz and the stirring time is 5-10 minutes.

[0107] Step 2: After mixing the ingredients, pack them into bags.

[0108] An embodiment of the present invention provides a method for preparing an air cushion film, comprising the following steps:

[0109] The system provides an outer layer component, a middle layer component, and an inner layer component. The outer layer component includes modified plastic particles coated with talc powder. The modified plastic particles are composed of PPC, PBAT, and a molecular winding agent.

[0110] The outer layer component, middle layer component and inner layer component are co-extruded and blown into a film to form a thin film.

[0111] Specifically, materials for the outer, middle, and inner layers are provided and added sequentially to the hopper of a three-layer co-extrusion blown film extruder. The interlayer ratio and blowing temperature are set, and the film is blown after holding at the temperature for 2 hours. The specific temperature settings are shown in the table below:

[0112] Table 3

[0113]

[0114]

[0115] The present invention provides a barrier paper air cushion, which includes an upper protective layer, an air cushion layer and a lower protective layer; the air cushion layer is an air cushion film as described above;

[0116] The upper and lower protective layers are made of kraft paper.

[0117] This invention provides a method for preparing the barrier paper air cushion as described above, comprising the following steps:

[0118] The upper protective layer, air cushion layer, and lower protective layer are stacked in a top-to-bottom order and pressed together using heated rollers.

[0119] Specifically, the blown film is placed on the middle rack, and kraft paper is placed on the upper and lower racks. A special mold is used to heat-seal patterns such as gourd shapes, streamlined shapes, and rectangles onto the film surface. The film is then pressed together using heated rollers and finally rolled up into a finished product. (See attached image for appearance reference.) Figure 3 and Figure 4 .

[0120] The following examples are provided to illustrate the present invention in more detail, but are not intended to limit the invention in any way.

[0121] The raw materials used in the embodiments of this invention are sourced from the following, but not limited to, the following: PPC is selected from the brand Zhongke Jinlong, grade T4; PBAT is selected from the brand Xinjiang Tunhe, grade th801; molecular winding agent is selected from the brand Mitsui Chemicals; PLA is selected from the brand Fengyuan, grade 804; silane coupling agent for activation is selected from the brand Jiangxi Guangyuan; calcium stearate is selected from the brand Huamingtai; PBST is selected from the brand Sinopec; and mesoamide is selected from the brand Jiangxi Weike.

[0122] In addition, unless otherwise specified, the raw materials used may be commercially available products in the field or prepared by conventional methods in the field.

[0123] Example 1

[0124] This embodiment describes an air cushion film, comprising an outer layer, a middle layer, and an inner layer;

[0125] (1) A method for modifying the outer layer component, comprising the following steps:

[0126] Step 1: Add 65 parts by weight of PPC granules, 32 parts by weight of PBAT, and 3 parts by weight of molecular winding agent to a high-speed mixer, keep the temperature below 35°C, the stirring frequency at 20Hz, and the stirring time at 3min.

[0127] Step 2: After the mixture is well stirred, pour it into the hopper of the twin-screw modifier.

[0128] The temperature settings for the modification machine are shown in the table below:

[0129] Table 4

[0130] Feeding section Heating section 1 Heating section 2 Heating section 3 Compression segment 4 80℃ 110℃ 125℃ 125℃ 125℃ Heating section 5 Heating section 6 Extrusion section mold head 125℃ 125℃ 125℃ 125℃

[0131] Among them, the modified tie rod adopts air cooling with a 10m cooling line to prevent the material from absorbing water;

[0132] Step 3: After pelleting, put the pellets into a mixing hopper. Preheat 2 parts by weight of talcum powder in the mixing hopper, and stir while pelleting to coat the surface of the pellets with talcum powder to prevent the pellets from sticking together.

[0133] Step 4: After mixing and stirring, pack into bags for later use.

[0134] (2) A method for modifying the middle layer component, comprising the following steps:

[0135] Step 1: Add 12 parts by weight of PLA, 59.7 parts by weight of PBAT, 3 parts by weight of molecular winding agent, 25 parts by weight of calcium carbonate, and 0.3 parts by weight of calcium stearate to a high-speed mixer. Set the temperature to 80℃, the stirring frequency to 20Hz, and the stirring time to 5min.

[0136] Step 2: After the mixture is stirred, pour it into the hopper of the twin-screw modifier.

[0137] The temperature settings for the modification machine are shown in the table below:

[0138] Table 5

[0139] Feeding section Heating section 1 Heating section 2 Heating section 3 Compression segment 4 100℃ 125℃ 135℃ 135℃ 135℃ Heating section 5 Heating section 6 Extrusion section mold head 135℃ 135℃ 135℃ 135℃

[0140] Among them, the modified tie rod adopts air cooling with a 10m cooling line to prevent the material from absorbing water;

[0141] Step 3: After cutting into small pieces, pack them into bags for later use.

[0142] (3) A method for modifying the inner layer components, comprising the following steps:

[0143] Step 1: Add 50 parts by weight of PBST, 48.8 parts by weight of PBAT, and 0.2 parts by weight of mesoamide to a high-speed mixer. No heating is required. The stirring frequency is 20 Hz and the stirring time is 5 min.

[0144] Step 2: After the mixture is stirred, pack it into bags for later use.

[0145] (4) Add the materials obtained from the outer, middle and inner layers to the hopper of the three-layer co-extrusion blown film extruder in sequence, set the interlayer ratio, set the blowing temperature, and hold for 2 hours before blowing film. The specific temperature settings are shown in the table below:

[0146] Table 6

[0147] Serial Number Heating section 1 Heating section 2 Heating section 3 Compression segment 4 Heating section 5 mold head A floor 100℃ 145℃ 145℃ 145℃ 145℃ 145℃ Floor B 120℃ 160℃ 160℃ 160℃ 160℃ 160℃ C layer 120℃ 145℃ 145℃ 145℃ 145℃ 145℃

[0148] (5) Place the blown film on the middle material rack, place kraft paper on the upper and lower material racks, use a special mold to heat seal patterns such as gourd balls, streamlined shapes, rectangles, etc. on the surface of the film, and press it with a heating roller at a temperature of 120°C. Finally, roll it up into a finished product.

[0149] Example 2

[0150] This embodiment is similar to Embodiment 1, except that the molecular winding agent is replaced with 0.2 parts by weight of chain extender BASF 4468.

[0151] Example 3

[0152] This embodiment is similar to Embodiment 1, except that the molecular winding agent is replaced with 10 parts by weight of maleic anhydride-grafted PBAT compatibilizer.

[0153] Example 4

[0154] This embodiment is similar to Embodiment 1, except that no polymer winding agent was added.

[0155] The products obtained in Examples 1-4 were subjected to surface observation, longitudinal tensile strength, longitudinal tensile strength after aging at 80°C for 72 hours, and oxygen permeability tests, respectively.

[0156] Among them, surface observation (abbreviated as: appearance) refers to the number of particles larger than 0.5mm contained in a unit area (50*50cm) by visual inspection; longitudinal tensile strength (MPa) is tested according to the test standard GB / T1040.3-2006; longitudinal tensile strength (MPa) after aging at 80℃ for 72 hours is tested according to the test standard GB / T1040.3-2006; oxygen permeability (cm 3 / (m 2 *24H*0.1MPa)) means: tested according to the test standard of ASTM D1434-82.

[0157] The performance test results are shown in the table below:

[0158] Table 7

[0159] project Apparent Longitudinal tensile strength Longitudinal tensile strength after aging at 80℃ for 72 hours oxygen permeability Example 1 0 36 34 86 Example 2 17 28 26 — Example 3 8 26 22 204 Example 4 0 18 11 382

[0160] As can be seen from the table above, neither Example 1 with the addition of a molecular winding agent nor Example 4 without the addition of a compatibilizer showed crystal point problems. However, Example 4 without the addition of a compatibilizer had poor performance and poor compatibility between materials.

[0161] While both Examples 2 and 3 improved material compatibility, they both exhibited varying degrees of crystal point formation, with the reaction being particularly vigorous with the chain extender 4468 used in Example 2. The addition of a molecular entanglement agent showed the best compatibility with chain extender 4468 and resulted in superior performance. This was particularly evident in the performance after aging. However, in Example 2, the chain extender caused perforation due to crystal point issues, leading to barrier failure.

[0162] Therefore, it can be seen that the molecular winding agent used in this invention can provide material compatibility without forming crystal points.

[0163] Example 5

[0164] This embodiment is similar to Embodiment 1, except that the talc in the outer layer component is replaced with 2000-mesh activated calcium carbonate.

[0165] Example 6

[0166] This embodiment is similar to Embodiment 1, except that talc is not added to the outer layer components.

[0167] Example 7

[0168] This embodiment is similar to Embodiment 1, except that the talc in the outer layer component is replaced with 0.4 parts by weight of mesoamide.

[0169] The products obtained in Examples 1 and 5-7 were subjected to surface observation, longitudinal tensile strength, longitudinal tensile strength after aging at 80°C for 72 hours, and oxygen permeability tests, respectively.

[0170] Among them, surface observation (abbreviated as: appearance) refers to the number of particles larger than 0.5mm contained in a unit area (50*50cm) by visual inspection; longitudinal tensile strength (MPa) is tested according to the test standard GB / T1040.3-2006; longitudinal tensile strength (MPa) after aging at 80℃ for 72 hours is tested according to the test standard GB / T1040.3-2006; oxygen permeability (cm 3 / (m 2 *24H*0.1MPa)) means: tested according to the test standard of ASTM D1434-82.

[0171] The performance test results are shown in the table below:

[0172] Table 8

[0173] project Apparent Longitudinal tensile strength Longitudinal tensile strength after aging at 80℃ for 72 hours oxygen permeability Example 1 0 36 34 86 Example 5 5 32 33 152 Example 6 - - - - Example 7 - - - -

[0174] As can be seen from the table above, although calcium carbonate was used instead of talc in Example 5 to prevent particle sticking, it could not be evenly dispersed in the material under single-screw plasticizing blown film conditions because calcium carbonate itself does not have a slippery effect, resulting in the appearance of local crystal points and small particles. Furthermore, its granular structure can also affect the barrier properties of the material to some extent.

[0175] Example 6 shows that without the addition of talc, the particles would stick together and become unusable.

[0176] In Example 7, using mesoamide to replace talc powder provided some anti-sticking effect, but due to its small dosage, the uniformity of particle coating was poor, making it difficult to completely solve the problem of particle adhesion. Furthermore, increasing the amount of mesoamide would not only result in higher costs, but more importantly, the mesoamide would subsequently precipitate, affecting the film's performance and leading to film adhesion problems and the inability to heat-seal with kraft paper.

[0177] Example 8

[0178] This embodiment is similar to Embodiment 1, except that calcium stearate was not added to the middle layer component.

[0179] Example 9

[0180] This embodiment is similar to Embodiment 1, except that activated calcium carbonate was not added to the middle layer component.

[0181] Example 10

[0182] This embodiment is similar to Embodiment 1, except that PLA is not added to the middle layer components.

[0183] The products obtained in Examples 1 and 8-10 were tested for heat-sealing burst temperature, surface observation, and longitudinal tensile strength, respectively.

[0184] Among them, the heat seal burst temperature is the temperature at which the film breaks under a horizontal tensile force of 10N and a vertical heat seal pressure of 10kg; surface observation (abbreviated as: appearance) is the number of particles larger than 0.5mm contained in a unit area (50*50cm) by visual inspection; longitudinal tensile strength (MPa) is tested according to the test standard of GB / T1040.3-2006.

[0185] The performance test results are shown in the table below:

[0186] Table 9

[0187] project Heat sealing and burn temperature Apparent Longitudinal tensile strength Example 1 125 0 36 Example 8 120 10 35 Example 9 118 0 38 Example 10 123 0 28

[0188] As can be seen from the table above, in Example 8, the hot melt temperature decreased by 5°C after the addition of calcium stearate, and the dispersion of calcium carbonate deteriorated, resulting in crystal point problems. This shows that calcium stearate not only improves the thermal stability of the material, but also improves the dispersion of powder.

[0189] In Example 9, although the longitudinal tensile strength was slightly improved without the addition of calcium carbonate, the heat-sealing bursting temperature decreased to some extent.

[0190] Example 10 shows a significant decrease in performance due to the lack of PLA, including reduced strength and softening of the material.

[0191] Example 11

[0192] This embodiment is similar to Embodiment 1, except that the amount of PPC added to the outer layer component is reduced to 30% by weight.

[0193] Example 12

[0194] This embodiment is similar to Embodiment 1, except that the amount of PPC added to the outer layer component is reduced to 40% by weight.

[0195] Example 13

[0196] This embodiment is similar to Embodiment 1, except that the amount of PPC added to the outer layer component is reduced to 50% by weight.

[0197] Example 14

[0198] This embodiment is similar to Embodiment 1, except that the amount of PPC added to the outer layer component is increased to 80% by weight.

[0199] Example 15

[0200] This embodiment is similar to Embodiment 1, except that the amount of PPC added to the outer layer component is increased to 90% by weight.

[0201] The products obtained in Examples 1 and 11-15 were subjected to tests on the bonding strength between the non-heat-sealable area of ​​kraft paper and the film; the performance test results are shown in the table below:

[0202] Table 10

[0203]

[0204] As can be seen from the table above, when the amount of PPC added in Example 11 was reduced to 30% by weight, the film did not adhere well to the kraft paper after being hot-pressed by the rollers.

[0205] In Example 12, as the amount of PPC added increased, the adhesion between the film and kraft paper improved after hot pressing with rollers, but it was still difficult to meet the requirements.

[0206] Example 13: When the amount of PPC added is increased to 50% by weight, the adhesion between the film and kraft paper after hot pressing with rollers increases significantly, thus meeting the usage requirements.

[0207] In Example 14, when the amount of PPC added was further increased to 80% by weight, the adhesion between the film and kraft paper began to show a downward trend after hot pressing with rollers, but it could still meet the usage standards.

[0208] In Example 15, when the amount of PPC added was increased to 90% by weight, the adhesion between the film and kraft paper after hot pressing with rollers began to decrease significantly because it was too sticky and had lost its strength, thus failing to meet the requirements.

[0209] Therefore, for the technical solution of the outer layer of this invention, the PPC content is optimal at 50%-80% by weight.

[0210] Example 16

[0211] This embodiment is similar to Embodiment 1, except that PBST in the inner layer component is replaced with PBAT.

[0212] Example 17

[0213] This embodiment is similar to Embodiment 1, except that PBST in the inner layer component is replaced with PLA.

[0214] The products obtained in Examples 1 and 16-17 were subjected to inner layer adhesion tests, inner layer heat seal strength tests, and longitudinal tensile strength tests, respectively; the performance test results are shown in the table below:

[0215] Table 11

[0216]

[0217] As can be seen from the table above, in Example 16, the inner layer component was replaced with PBAT by PBST. After the film was pressed by rollers at 130°C, the inner layer of the film showed a sticky film phenomenon, and the product could not be inflated.

[0218] In Example 17, the inner layer component was replaced with PLA instead of PBST. After the film was pressed by rollers at 130°C, although no film sticking occurred in the inner layer of the film, the heat sealing strength decreased significantly, which seriously affected the performance of the air cushion product.

[0219] Therefore, PBST can increase the softening temperature of the inner layer, prevent the inner layer from sticking to the film during hot pressing by the rollers, and does not affect the heat sealing performance of the material itself.

[0220] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cushion film, characterized in that, The air cushion film includes an outer layer, a middle layer, and an inner layer; The outer layer comprises modified plastic particles coated with talc, wherein the modified plastic particles comprise PPC, PBAT, and a molecular winding agent; the main component of the molecular winding agent is a high molecular weight acrylate copolymer. Both the middle and inner layers contain PBAT. The components of the modified plastic particles coated with talc powder include: 50.0% to 80.0% by weight of PPC; 15.0% to 50.0% by weight of PBAT; 2.0% to 5.0% by weight of molecular winding agent; 1.0% to 2.0% by weight of talc; The components of the middle layer include: 50.0% to 65.0% by weight of PBAT; PLA, ranging from 8.0% to 15.0% by weight; 25.0% to 35.0% by weight of activated calcium carbonate; 2.0% to 5.0% by weight of molecular winding agent; 0.3% to 0.5% by weight of calcium stearate; The components of the inner layer include: 49.95% to 65.0% by weight of PBAT; 34.8% to 50.0% PBST; 0.05% to 0.2% by weight of a slip agent.

2. The air cushion film according to claim 1, characterized in that, The talc powder has a particle size of 2500 mesh or larger.

3. A method for preparing an air cushion film as described in claim 1 or 2, characterized in that, Includes the following steps: The system provides an outer layer component, a middle layer component, and an inner layer component. The outer layer component includes modified plastic particles coated with talc powder. The modified plastic particles are composed of PPC, PBAT, and a molecular winding agent. The outer layer component, middle layer component and inner layer component are co-extruded and blown into a film to form a thin film.

4. A barrier paper air cushion, characterized in that, The barrier paper air cushion includes an upper protective layer, an air cushion layer, and a lower protective layer; The air cushion layer is an air cushion film as described in any one of claims 1-2; The upper and lower protective layers are made of kraft paper.

5. The method for preparing the barrier paper air cushion as described in claim 4, characterized in that, Includes the following steps: The upper protective layer, air cushion layer, and lower protective layer are stacked in a top-to-bottom order and pressed together using heated rollers.

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