WO2023088239A1 - Flame-retardant high-toughness pla alloy material, and preparation method therefor and use thereof - Google Patents

Abstract

A flame-retardant high-toughness PLA alloy material, and a preparation method therefor and the use thereof. The flame-retardant high-toughness PLA alloy material comprises a PLA resin, an ACS resin, an inorganic filler, a compatibilizer, a nucleating agent and other processing aids. In the flame-retardant high-toughness PLA alloy material, by means of collaborative cooperation among the specific PLA resin, ACS resin and inorganic filler, the flame retardancy and toughness of the PLA material are significantly improved, and the resulting PLA alloy material has relatively high toughness and a flame retardant grade of UL94V-2; moreover, the material achieves good appearance quality during 3D printing, and can be widely used in the field of 3D printing.

Description

A kind of flame-retardant high-toughness PLA alloy material and its preparation method and application technical field

The invention belongs to the technical field of 3D printing materials, and in particular relates to a flame-retardant high-toughness PLA alloy material and its preparation method and application.

Background technique

Compared with traditional injection molding, compression molding and other processes, 3D printing (3DP) technology has the advantages of rapid prototyping, high precision and high material utilization, and has become a research hotspot and key field at home and abroad.

At present, there are many types of 3D printing technologies, and the mainstream methods include SLA (stereolithography), LOM (layered solid manufacturing), SLS (selective laser sintering) and FDM (melting extrusion deposition molding) and other methods. . Among them, the FDM method has lower requirements on 3D printing equipment, and the printing operation is simple and convenient. It is a 3D printing method widely used in the market.

At present, the materials suitable for the FDM method mainly include acrylonitrile-butadiene-styrene terpolymer (ABS), polylactic acid (PLA), nylon (PA) and polycarbonate (PC), among which PLA is the most commonly used. As a new type of excellent biopolymer material, PLA has the advantages of non-toxicity, non-irritation, good biocompatibility, high strength, biodegradability and absorption, etc., but it also has the disadvantages of low impact strength and brittle physical properties. The material is not fireproof and burns easily, which greatly limits its application.

Existing patents disclose a flame-retardant polylactic acid additive and its preparation method. In this method, an initiator is added to generate active sites on the main chain of polylactic acid, so that it can further react with a reactive flame retardant to obtain a reactive flame retardant. Flame-retardant polylactic acid, while adding phosphorus and nitrogen synergistic flame retardants and tougheners such as nitrile rubber, prepared a polylactic acid material with flame retardancy and high melt flow rate; there are also patents that disclose a method for 3D The printed flame-retardant and antibacterial PLA biodegradable composite material can reach UL94V-0 level by adding 5-10 parts of DOPO derivative flame retardant. Both of these two schemes achieve the flame retardant effect by adding a flame retardant, which is costly and the overall toughness of the material is not good.

In addition, there is also a patent disclosing an ABS/PLA alloy resin composition for 3D printing and its preparation method, using peroxide as a crosslinking agent, and adopting a reactive extrusion blending method to make ABS resin and PLA resin The reaction takes place to prepare an ABS/PLA alloy resin with high strength, high toughness, high dimensional stability, low carbon and environmental protection. This solution uses ABS as a toughening agent, which has general toughness and is not flame retardant.

Therefore, it is of great research significance and application value to develop a PLA material with excellent flame retardancy and toughness.

Contents of the invention

The purpose of the present invention is to overcome the defects or deficiencies of the prior art, and provide a flame-retardant high-toughness PLA alloy material. The flame-retardant high-toughness PLA alloy material provided by the present invention significantly improves the flame-retardant performance and toughness of the PLA material through the synergistic cooperation of specific PLA resin, ACS resin and inorganic fillers, and the obtained PLA alloy material has higher toughness and toughness. UL94V-2 flame retardant grade, and the appearance quality of 3D printing is good, which can be widely used in the field of 3D printing.

Another object of the present invention is to provide a method for preparing the above-mentioned flame-retardant high-toughness PLA alloy material.

Another object of the present invention is to provide the application of the above-mentioned flame-retardant high-toughness PLA alloy material in the preparation of 3D printed products.

In order to realize the above-mentioned purpose of the invention, the present invention adopts following technical scheme:

A flame-retardant high-toughness PLA alloy material, comprising the following components in parts by weight:

The PLA resin (polylactic acid resin) has a melt index (MI) of 8-15g/10min at 190°C/2.16kg according to ISO 1133-2012;

The ACS resin (acrylonitrile-chlorinated polyethylene-styrene terpolymer resin) has a melt index of 20 to 50 g/10 min at 220° C./10 kg according to ISO1133-2012;

The aspect ratio of the inorganic filler is (10-50):1.

After research, it is found that the PLA alloy material obtained by compounding low-viscosity PLA resin and high-fluidity ACS resin and adding inorganic fillers with a large aspect ratio has a higher flame retardancy level and better toughness. And the appearance quality is excellent, the reason may be:

(1) ACS has excellent comprehensive mechanical properties, especially good toughness, and because it does not contain C=C double bonds, it has excellent weather resistance; in addition, because ACS itself contains halogen, it can be used without using or adding a small amount of flame retardants. The flame retardant effect can be achieved. But its compatibility with PLA is poor. When low-viscosity PLA resin and high-flow ACS resin are selected as the resin system, the compatibility between PLA resin and ACS resin can be improved, and the flame retardancy and toughness of PLA alloy materials can be improved; but the melt of ACS Compared with PLA, the bonding performance is quite different, and its shrinkage rate is relatively large. The introduction of ACS into PLA will lead to uneven discharge of the material melt, and subsequent cracking is very easy, which will deteriorate the appearance quality of PLA alloy materials during 3D printing.

(2) Inorganic fillers with high aspect ratio can be distributed along the flow direction inside the material. Since its shrinkage rate is an order of magnitude lower than that of resin, it plays a supporting role when the material shrinks or expands, reducing material deformation, thus making 3D printing The appearance of the part is uniform, delicate and free of cracks, which can improve the appearance quality; if the aspect ratio of the inorganic filler is too small, it will not be able to reduce the shrinkage of the material, and there will be no significant improvement in the appearance of the 3D printed part .

That is to say, the present invention significantly improves the flame retardant performance and toughness, and effectively improves the appearance quality by selecting specific PLA resin, ACS resin and inorganic filler for compounding.

Conventional low-viscosity PLA resins and high-fluidity ACS resins in the field can be used in the present invention.

Preferably, the PLA resin is one or more of L-polylactic acid PLLA, D-polylactic acid PDLA or racemic polylactic acid PDLLA.

Preferably, the melt index of the ACS resin is 30-40 g/10 min.

Preferably, the inorganic filler is at least one of inorganic salt whiskers, talc powder, marble powder, mica powder, calcium metasilicate, kaolin and montmorillonite.

More preferably, the inorganic salt whiskers are one of SiC whiskers, potassium titanate whiskers, aluminum borate whiskers, calcium sulfate whiskers, calcium carbonate whiskers, aluminum oxide whiskers or zinc oxide whiskers or several.

Preferably, the aspect ratio of the inorganic filler is (14-22):1.

Common compatibilizers and nucleating agents in the field can be used in the present invention.

Preferably, the compatibilizer is methyl methacrylate, styrene-acrylonitrile copolymer grafted maleic anhydride, styrene-butadiene-acrylonitrile copolymer grafted maleic anhydride, styrene-acrylonitrile - Glycidyl methacrylate, styrene-butadiene-acrylonitrile-glycidyl methacrylate, styrene-maleic anhydride copolymer, ethylene-acrylate-glycidyl ester copolymer, ethylene-glycidyl ester Or one or more of ethylene-n-butyl acrylate-glycidyl ester copolymers.

Preferably, the nucleating agent is layered silicates, layered phosphates, rare earths, ZnO, carbon nanotubes, calcium carbonate-loaded polylactic acid, calcium carbonate-loaded hydrazides, calcium carbonate-loaded amides, One or more of calcium carbonate-loaded esters or supramolecular organic nucleating agents.

Preferably, the other processing aids are one or more of antioxidants, lubricants, weather resistance agents or colorants.

More preferably, the antioxidant is one or more of phenolic antioxidants, phosphate antioxidants or thioester antioxidants. The parts by weight of the antioxidant are 0-0.5 parts.

Further preferably, the phenolic antioxidant is β-(3,5-di-tert-butyl-4-hydroxyphenyl) n-octadecyl propionate, tetrakis[methyl-β-(3,5 -Di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol ester, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate ], 4,4'-thiobis(6-tert-butyl-3-methylphenol) or one or more of 2,6-di-tert-butylphenol.

Further preferably, the phosphate antioxidant is tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite or bis One or more of (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate.

Further preferably, the thioester antioxidant is one of pentaerythritol tetrakis (3-lauryl thiopropionate), dioctadecyl thiodipropionate or dilauryl thiodipropionate or several.

More preferably, the lubricant is one or more of ethylene bis stearic acid amide, stearic acid esters, metal soaps or silicone. The parts by weight of the lubricant are 0-1 part.

Further preferably, the stearic acid esters are one or more of n-butyl stearate, pentaerythritol stearate, monoglyceryl stearate or glyceryl tristearate.

Further preferably, the metal soaps are one or more of calcium stearate, zinc stearate or magnesium stearate.

More preferably, the weather resistance agent is one or more of benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers or hindered amine light stabilizers.

More preferably, the colorant is one or more of titanium dioxide, cadmium-based pigments, iron red, ultramarine blue, carbon black, phthalocyanine-based organic pigments or quinacridone-based organic pigments. The parts by weight of the colorant are 0-2 parts.

The preparation method of the above-mentioned flame-retardant high-toughness PLA alloy material includes the following steps: uniformly mixing PLA resin, ACS resin, inorganic filler, compatibilizer, nucleating agent and other processing aids to obtain a mixture, and then melting the mixture Extrude and granulate to obtain the flame-retardant high-toughness PLA alloy material.

Preferably, the preparation method of the flame-retardant high-toughness PLA alloy material includes the following steps: adding PLA resin, ACS resin, inorganic filler, compatibilizer, nucleating agent and other processing aids to a high-speed mixer and fully mixing 5 ~10 minutes to obtain the compound material, then put the compound material into a twin-screw extruder to melt and extrude, and granulate to obtain the flame-retardant high-toughness PLA alloy material.

More preferably, the screw temperature of each stage of the twin-screw extruder is 160-200° C., the aspect ratio is (30-45):1, and the screw speed is 200-500 rpm.

Preferably, the PLA further includes a drying step before mixing, more preferably drying in a vacuum oven at 80°C for 4-8 hours.

The application of the above-mentioned flame-retardant high-toughness PLA alloy material in the preparation of 3D printing consumables is also within the protection scope of the present invention.

Compared with the prior art, the present invention has the following beneficial effects:

The flame-retardant high-toughness PLA alloy material provided by the present invention significantly improves the flame-retardant performance and toughness of the PLA material through the synergistic cooperation of specific PLA resin, ACS resin and inorganic fillers, and the obtained PLA alloy material has higher toughness and toughness. UL94V-2 flame retardant grade, and the appearance quality of 3D printing is good, which can be widely used in the field of 3D printing.

Description of drawings

Figure 1 is a representative schematic diagram of the "excellent" 3D printing appearance;

Figure 2 is a representative schematic diagram of a "good" 3D printing appearance;

Figure 3 is a representative schematic diagram of the "general" visual inspection of the appearance of 3D printing;

Figure 4 is a representative schematic diagram of the "poor" visual appearance of 3D printing.

Detailed ways

The present invention is further set forth below in conjunction with embodiment. These examples are only for illustrating the present invention and are not intended to limit the scope of the present invention. The experimental method that does not indicate specific conditions in the following example embodiment, usually according to the conventional conditions in this field or according to the conditions suggested by the manufacturer; used raw materials, reagents, etc., if no special instructions, are available from commercial channels such as conventional markets Raw materials and reagents obtained. Any insubstantial changes and substitutions made by those skilled in the art on the basis of the present invention fall within the scope of the present invention.

The partial reagents that each embodiment of the present invention and comparative examples select are described as follows:

PLA resin 1#: PLA 3001D, MI 10g/10min (190℃/2.16kg, ISO 1133-2012), Zhuhai Wantong Chemical Co., Ltd.;

PLA resin 2#: PLA 3001A, MI 8g/10min (190℃/2.16kg, ISO 1133-2012), Zhuhai Wantong Chemical Co., Ltd.;

PLA resin 3#: PLA 3002D, MI 14g/10min (190℃/2.16kg, ISO 1133-2012), Zhuhai Wantong Chemical Co., Ltd.;

PLA resin 4#: PLA 2003D: MI is 3.5g/10min (190℃/2.16kg, ISO 1133-2012), Zhuhai Wantong Chemical Co., Ltd.;

ACS resin 1#: ACS-C40, MI 34g/10min (220℃/10kg, ISO 1133-2012), Kingfa Science & Technology Co., Ltd.;

ACS resin 2#: ACS-C20, MI is 22g/10min (220℃/10kg, ISO 1133-2012), Kingfa Science & Technology Co., Ltd.;

ACS resin 3#: ACS-C50, MI 50g/10min (220℃/10kg, ISO 1133-2012), Kingfa Science & Technology Co., Ltd.;

ACS resin 4#: ACS-C10, MI is 9g/10min (220℃/10kg, ISO 1133-2012), Kingfa Science & Technology Co., Ltd.

Inorganic filler 1#: DL-10, activated anhydrous calcium sulfate whisker, the aspect ratio is about 17:1, Changzhou Guangwei New Material Technology Co., Ltd.;

Inorganic filler 2#: HJMF-BAKF, inorganic silicate, aspect ratio about 11:1, Jiangxi Huajietai Mineral Fiber Technology Co., Ltd.;

Inorganic filler 3#: CSW-45H, activated anhydrous calcium sulfate whisker, the aspect ratio is about 46:1, Changzhou Guangwei New Material Technology Co., Ltd.;

Inorganic filler 4#: AB-3000N1: barium sulfate, the aspect ratio is about 1:1, Guangzhou Huangpu Tiantai Chemical Light Co., Ltd.;

Compatibilizer: methyl methacrylate, commercially available;

Nucleating agent: layered silicate nucleating agent, commercially available;

Antioxidant: Antioxidant 1010 and Antioxidant 168 are compounded at a weight ratio of 1:2; Antioxidant 1010 is commercially available; Antioxidant 168 is commercially available;

Lubricant: ethylene bis stearic acid amide lubricant, commercially available;

Weather resistance agent: benzotriazole ultraviolet light absorber, commercially available.

It should be understood that, unless otherwise specified, a certain component (such as a compatibilizer, a nucleating agent, an antioxidant, a lubricant, and a weather-resistant agent) in each of the examples and comparative examples is the same commercially available product.

The preparation method of the PLA alloy material of each embodiment and comparative example of the present invention is as follows: first put the PLA resin in a vacuum drying oven at 80°C and dry it for 6 hours, then add each raw material into a high-speed mixer according to the proportion and mix them uniformly, and then mix the above-mentioned The mixture is sent into the twin-screw extruder for kneading, extruding, stranding, water cooling, and pelletizing; wherein, the aspect ratio of the twin-screw extruder is 40:1; the temperature of the screw barrel is set as: the temperature in the first zone is 160 ℃, the temperature in the second zone is 160 ℃, the temperature in the third zone is 200 ℃, the temperature in the fourth zone is 200 ℃, the temperature in the fifth zone is 200 ℃, the temperature in the sixth zone is 200 ℃, the temperature in the seventh zone is 200 ℃, the temperature in the eighth zone is 200 ℃, the temperature in the ninth zone is 200 ℃, The temperature in the tenth zone is 200°C, the temperature of the machine head is 220°C, and the screw speed is 300 rpm.

The PLA alloy materials of the various embodiments and comparative examples of the present invention were tested according to the performance indicators in Table 1.

Table 1 Performance test method

Performance	Test Conditions	Test Methods
Flame retardant test	Thickness: 1.75mm	UL94-2018
Izod notched impact strength	23°C	ISO 180-2000, notch type is type A
3D printing appearance	-	visual inspection

Among them, the visual inspection method of 3D printing appearance: 3D printing under the same conditions as shown in Fig. 1 to 4 parts (7cm high, external area about 30cm ² ), visual inspection, according to whether the appearance of the entire part is cracked/uniform/delicate, from excellent to Inferior is divided into ● (excellent, no cracks/uniform/very delicate, as shown in Figure 1), 〇(good, no large cracks and only 1-3 small cracks/relatively uniform/delicate, as shown in Figure 2), △( Generally, 1-2 large cracks/a small amount of unevenness/general fineness, as shown in Figure 3), ╳(poor, 3 or more large cracks/unevenness/roughness, as shown in Figure 4).

Embodiment 1～10 and comparative example 1～5

The present embodiment and comparative example provide a series of PLA alloy materials, the formulations of which are shown in Table 2.

The formula (part) of table 2 embodiment 1～10 and comparative example 1～5

The test results are shown in Table 3.

The performance test result of the PLA alloy material that table 3 embodiment and comparative example provide

From the above test results, it can be seen that the PLA alloy materials provided in each example have toughness, the notched impact of the Izod beam can reach more than 15kJ/m2, the flame retardancy level can reach UL94V- ² , and the appearance quality of 3D printing is excellent. The overall performance is the best. The PLA resin used in Comparative Example 1 has too high viscosity and poor compatibility with ACS resin. The notched Izod impact strength of the material is low, the flame retardant grade cannot reach UL94V-2, and the appearance quality is also poor; Comparative Example 2 The selected ACS resin has too high viscosity, poor fluidity, and poor compatibility with PLA resin, which cannot effectively improve the toughness and flame retardancy level, and the appearance quality is poor. In Comparative Example 3, no ACS resin was added, although the appearance quality was excellent, but the toughness was poor and the flame retardancy level was low. The aspect ratio of the inorganic filler added in Comparative Example 4 is close to 1:1, the supporting effect is very small, and the purpose of reducing the shrinkage of the material cannot be achieved. The melt discharge is not uniform during the 3D printing process and the size of the material changes greatly during subsequent cooling. , leading to poor appearance uniformity, not delicate, and easy to crack, which cannot effectively improve the appearance quality, and also has a certain deterioration effect on toughness. In Comparative Example 5, no inorganic filler was added. Due to the introduction of ACS, the melt bonding performance of the material was low, and the shrinkage rate was large. Although the toughness and flame retardancy level were effectively improved, the appearance quality was poor.

Those skilled in the art will appreciate that the embodiments herein are to help readers understand the principles of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical revelations disclosed in the present invention without departing from the essence of the present invention, and these modifications and combinations are still within the protection scope of the present invention.

Claims (10)

1. A flame-retardant high-toughness PLA alloy material is characterized in that it includes the following components in parts by weight:

   

   According to ISO 1133-2012, the PLA resin has a melt index of 8-15g/10min at 190°C/2.16kg;

   According to ISO 1133-2012, the ACS resin has a melt index of 20-50g/10min at 220°C/10kg;

   The aspect ratio of the inorganic filler is (10-50):1.
2. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the PLA resin is one or more of L-polylactic acid PLLA, D-polylactic acid PDLA or racemic polylactic acid PDLLA.
3. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the melt index of the ACS resin is 30-40g/10min.
4. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the inorganic filler is inorganic salt whisker, talcum powder, marble powder, mica powder, calcium metasilicate, kaolin or montmorillonite one or several.
5. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the aspect ratio of the inorganic filler is (14-22):1.
6. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the compatibilizer is methyl methacrylate, styrene-acrylonitrile copolymer grafted maleic anhydride, styrene-butadiene- Acrylonitrile copolymer grafted maleic anhydride, styrene-acrylonitrile-glycidyl methacrylate, styrene-butadiene-acrylonitrile-glycidyl methacrylate, styrene-maleic anhydride copolymer, ethylene - One or more of acrylate-glycidyl ester copolymer, ethylene-glycidyl ester or ethylene-n-butyl acrylate-glycidyl ester copolymer.
7. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the nucleating agent is layered silicates, layered phosphates, rare earths, ZnO, carbon nanotubes, calcium carbonate loaded poly One or more of lactic acid, calcium carbonate-supported hydrazides, calcium carbonate-supported amides, calcium carbonate-supported esters or supramolecular organic nucleating agents.
8. The flame-retardant high-toughness PLA alloy material according to claim 1, wherein the other processing aids are one or more of antioxidants, lubricants, weather-resistant agents or colorants.
9. The preparation method of the flame-retardant high-toughness PLA alloy material described in any one of claims 1 to 8 is characterized in that it comprises the following steps: adding PLA resin, ACS resin, inorganic filler, compatibilizer, nucleating agent and other processing aids The mixture is uniformly mixed to obtain a mixture, and then the mixture is melt-extruded and granulated to obtain the flame-retardant high-toughness PLA alloy material.
10. The application of the flame-retardant high-toughness PLA alloy material in any one of claims 1 to 8 in the preparation of 3D printed products.

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