Green flame-retardant thermoplastic polyurethane foam material and preparation method thereof

Abstract

The invention discloses a green flame-retardant thermoplastic polyurethane foam material and a preparation method thereof. The green flame-retardant thermoplastic polyurethane foam material is prepared from the following raw materials in parts by weight: 60 to 75 parts of thermoplastic polyurethane (TPU), 25 to 30 parts of an intumescent flame retardant (IFR), 5 to 10 parts of aluminum hydroxide (ATH), 0.1 to 0.8 part of a catalyst, 0.8 to 1.5 parts of a lubricant, 0.1 to 1.2 parts of a deodorant and 0.3 to 1.2 parts of an antioxidant. The preparation method of the green flame-retardant thermoplastic polyurethane foaming material comprises the following steps: sequentially adding the components into a high-speed mixer according to the proportion, uniformly mixing, then adding into a hopper of a double-screw extruder, carrying out melting reaction extrusion, and pelletizing to obtain the green flame-retardant thermoplastic polyurethane foaming material. After CO2 supercritical foaming, cooling and sizing are performed to prepare the green flame-retardant thermoplastic polyurethane foaming material. The green flame-retardant thermoplastic polyurethane foaming material prepared by the invention has the characteristics of efficient flame retardance, light weight, no halogen, environment friendliness, easiness in recovery and recyclability, has very excellent comprehensive performance, and is an ideal flame-retardant environment-friendly foaming composite material.

Description

Technical Field

[0001] The present invention relates to a flame-retardant foaming material and a preparation method thereof, and particularly to a green flame-retardant thermoplastic polyurethane foaming material and a preparation method thereof, belonging to the field of polymer material modification. Background Art

[0002] Traditional flame-retardant foaming materials are mainly halogen-based flame-retarded EVA and PU foams. Although they have good flame retardancy, the combustion substances pose a carcinogenic risk, rely on bromides or chlorides, release toxic gases (dioxins, HBr) during combustion, violate EU regulations such as RoHS and REACH, have a relatively complex production process, high energy consumption, and are not easily recyclable. Therefore, developing a more green and environmentally friendly flame-retardant foaming composite material has become a hot issue in the industry. Summary of the Invention

[0003] The purpose of the present invention is to provide a green and environmentally friendly flame-retardant foaming composite material and a preparation method thereof for the above problems. The present invention uses thermoplastic polyurethane as the basic material and combines inorganic flame retardant aluminum hydroxide and intumescent flame retardant IFR to prepare a green flame-retardant thermoplastic polyurethane foaming material with characteristics such as high-efficiency flame retardancy, lightweight, halogen-free environmental protection, easy recycling, and recyclability, and its comprehensive performance is very excellent.

[0004] In order to achieve the above invention purpose, the present invention adopts the following technical solutions:

[0005] A green flame-retardant thermoplastic polyurethane foaming material is prepared from the following raw materials in parts by weight: 60 - 75 parts of thermoplastic polyurethane (TPU), 25 - 30 parts of intumescent flame retardant (IFR), 5 - 10 parts of aluminum hydroxide (ATH), 0.1 - 0.8 part of catalyst, 0.8 - 1.5 parts of lubricant, 0.1 - 1.2 parts of deodorant, and 0.3 - 1.2 parts of antioxidant. The preparation method of this green flame-retardant thermoplastic polyurethane foaming material is as follows: The above-mentioned components are added to a high-speed mixer in sequence according to the ratio, mixed evenly, then added to the hopper of a twin-screw extruder for melt reaction extrusion, pelletized, and then subjected to CO2 supercritical foaming and cooled and shaped to obtain a green flame-retardant thermoplastic polyurethane foaming material. The beneficial effects of the present invention are: The green flame-retardant thermoplastic polyurethane foaming material prepared by the present invention has characteristics such as high-efficiency flame retardancy, lightweight, halogen-free environmental protection, easy recycling, and recyclability, and its comprehensive performance is very excellent, and it is an ideal green and high-efficiency flame-retardant foaming composite material.

[0006] As a further optimized scheme of the green flame-retardant thermoplastic polyurethane foaming material provided by the present invention, the thermoplastic polyurethane (TPU) is polyester type and has a hardness of 90A.

[0007] As a further optimized solution for the green flame-retardant thermoplastic polyurethane foaming material provided by the present invention, the flame retardant is an intumescent flame retardant and an inorganic flame retardant (aluminum hydroxide). The intumescent flame retardant (IFR) is composed of an acid source (APP), a carbon source (pentaerythritol), and a gas source (melamine), which is efficient and low-smoke.

[0008] As a further optimized solution for the green flame-retardant thermoplastic polyurethane foaming material provided by the present invention, the catalyst is an organotin catalyst.

[0009] Preferably, the organotin compound is tin dimethyldithiocarbamate.

[0010] As a further optimized solution for the green flame-retardant thermoplastic polyurethane foaming material provided by the present invention, the lubricant is a silicone lubricant

[0011] As a further optimized solution for the green flame-retardant thermoplastic polyurethane foaming material provided by the present invention, the deodorant is a porous silicon-aluminum inorganic substance, which appears as a white powder.

[0012] As a further optimized solution for the green flame-retardant thermoplastic polyurethane foaming material provided by the present invention, the antioxidant is antioxidant 300.

[0013] To better achieve the above-mentioned invention purpose, the present invention also provides a preparation method for a green flame-retardant thermoplastic polyurethane foaming material, which is characterized in that the specific content of the preparation method is as follows:

[0014] The above-mentioned components are added to a high-speed mixer in sequence according to the ratio, mixed evenly, then added to the hopper of a twin-screw extruder for melt reaction extrusion, pelletized, and then subjected to CO2 supercritical foaming and cooled and shaped to obtain a green flame-retardant thermoplastic polyurethane foaming material. The beneficial effects of the present invention are as follows: The green flame-retardant thermoplastic polyurethane foaming material prepared by the present invention has the characteristics of high-efficiency flame retardancy, lightweight, halogen-free environmental protection, easy recycling, and recyclability, and its comprehensive performance is very excellent. It is an ideal green and high-efficiency flame-retardant foaming composite material.

[0015] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0016] (1) Compared with traditional flame-retardant foaming materials, halogen-free flame retardants are used to improve environmental protection and recyclability;

[0017] (2) Green flame-retardant TPU is used, which greatly leads in flame retardancy performance compared with the flame-retardant foaming materials on the market, and at the same time achieves lightweight and enhanced mechanical properties;

[0018] (3) The production cost is greatly reduced through one-step forming foaming and compatible flame-retardant injection molding methods. DETAILED DESCRIPTION

[0019] The invention provides a green flame retardant thermoplastic polyurethane foam material, which is prepared from the following raw materials in parts by weight: 60-75 parts of thermoplastic polyurethane (TPU), 25-30 parts of intumescent flame retardant (IFR), 5-10 parts of aluminum hydroxide (ATH), 0.1-0.8 parts of catalyst, 0.8-1.5 parts of lubricant, 0.1-1.2 parts of deodorant, and 0.3-1.2 parts of antioxidant. The preparation method of the green flame retardant thermoplastic polyurethane foam material is as follows: the above-mentioned components are added to a high-speed mixer in sequence according to proportion and mixed evenly, and then added to the hopper of a twin-screw extruder, melt-reacted and extruded, pelletized, and then CO2 supercritical foamed and cooled to obtain a green flame retardant thermoplastic polyurethane foam material.

[0020] The main polyurethane material used in the present invention is thermoplastic polyurethane, and its hardness is 90A.

[0021] Specifically, the polyester TPU is provided by Meirui New Materials, and its density is 0.88g / cm 3 Its density is 1.18-1.22g / cm3, tensile strength is 25-35MPa, and elongation at break is 400-600%.

[0022] The flame retardants used in the present invention are intumescent flame retardants and inorganic flame retardants (aluminum hydroxide). The intumescent flame retardant (IFR) is composed of an acid source (APP), a carbon source (pentaerythritol), and a gas source (melamine), and is highly efficient and low in smoke.

[0023] Specifically, the IFR has a decomposition temperature of 250-300°C, a phosphorus content of 18-25%, a flame retardant efficiency LOI>30% (after compounding with TPU), and the amount of aluminum hydroxide used can be reduced to 5-15% when compounding IFR.

[0024] The catalyst used in the present invention is an organic tin compound.

[0025] Specifically, the organic tin compound is dimethyl dithiocarbamate, which has a flash point of 200° C. and has the appearance of a solid powder.

[0026] The lubricant used in the present invention is methyl silicone oil.

[0027] Specifically, the methyl silicone oil has a flash point of ≥250° C., an oily liquid appearance, and a viscosity of 100-1000 mPa·s. The deodorant used in the present invention is a porous silicon-aluminum inorganic substance.

[0028] Specifically, the porous silicon-aluminum inorganic material is in the form of white powder with a purity of ≥99%.

[0029] The antioxidant used in the present invention is antioxidant 300.

[0030] Specifically, the antioxidant 300 is a hindered phenol antioxidant with a molecular weight of 358, a thermal decomposition temperature ≥ 300 °C, and an appearance of white powder.

[0031] In order to better achieve the above-mentioned invention object, the present invention also provides a preparation method of a green flame-retardant thermoplastic polyurethane foam material, which is characterized in that the specific content of the preparation method is as follows: The above-mentioned parts by weight of thermoplastic polyurethane (TPU), intumescent flame retardant (IFR), aluminum hydroxide (ATH), catalyst, lubricant, deodorant, and antioxidant are added to a high-speed mixer and mixed evenly, and then added to a twin-screw extruder for melt extrusion and pelletization, and after CO2 supercritical foaming, it is cooled and shaped to prepare a green flame-retardant thermoplastic polyurethane foam material.

[0032] The following examples further illustrate the content of the present invention, but should not be construed as a limitation of the present invention. Without departing from the spirit and essence of the present invention, partial modifications or substitutions made to the methods, steps or processes of the present invention all fall within the protection scope of the present invention.

[0033] Examples 1 to 4: A green flame-retardant thermoplastic polyurethane foam material, and its components and parts by weight are as shown in Table 1 below:

[0034] Table 1:

[0035]

[0036]

[0037] Table 2, the test results of various performances of Examples 1 to 4:

[0038] Table 2:

[0039]

[0040] The above examples show that a green flame-retardant thermoplastic polyurethane foam material prepared by the present invention has the characteristics of high-efficiency flame retardancy, light weight, halogen-free environmental protection, easy recycling, and recyclability, etc. Its comprehensive performance is very excellent, and it is an ideal green and highly efficient flame-retardant foaming composite material.

[0041] The above is only the preferred embodiments of the present invention and is not intended to limit the present invention. Any partial changes to the formula and process on this basis should be within the protection scope of the present invention.

Claims

1. A green flame retardant thermoplastic polyurethane foam material and a preparation method, characterized in that: The invention is prepared from the following raw materials in parts by weight: 60-75 parts of thermoplastic polyurethane (TPU), 25-30 parts of intumescent flame retardant (IFR), 5-10 parts of aluminum hydroxide (ATH), 0.1-0.8 parts of catalyst, 0.8-1.5 parts of lubricant, 0.1-1.2 parts of deodorant and 0.3-1.2 parts of antioxidant.

2. The green flame-retardant thermoplastic polyurethane foam material according to claim 1, characterized in that: The thermoplastic polyurethane (TPU) is polyester-type and has a hardness of 90A.

3. The green flame retardant thermoplastic polyurethane foam material according to claim 1, characterized in that: The flame retardant is an intumescent flame retardant and an inorganic flame retardant.

4. The green flame retardant thermoplastic polyurethane foam material according to claim 1, characterized in that: The catalyst is an organic tin catalyst.

5. The green flame-retardant thermoplastic polyurethane foam material according to claim 1, characterized in that: The lubricant is a silicone lubricant.

6. The green flame retardant thermoplastic polyurethane foam material according to claim 1, characterized in that: The deodorant is a porous silicon-aluminum inorganic substance and is in the form of white powder.

7. The green flame retardant thermoplastic polyurethane foam material according to claim 1, characterized in that: The antioxidant is antioxidant 300.

8. A method for preparing a green flame retardant thermoplastic polyurethane foam material according to any one of claims 1 to 7, characterized in that: The specific content of the preparation method is as follows: the thermoplastic polyurethane (TPU), intumescent flame retardant (IFR), aluminum hydroxide (ATH), catalyst, lubricant, deodorant and antioxidant in the above-mentioned weight proportions are added to a high-speed mixer according to a proportion and mixed evenly, and then added to a twin-screw extruder for melt extrusion and pelletizing, and then cooled and shaped after CO2 supercritical foaming to prepare a green flame-retardant thermoplastic polyurethane foam material.

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