A polyamide molding composition and its preparation method and application

Abstract

The invention discloses a polyamide molding composition, which comprises the following components by weight: 60 parts of polyamide; 0.05-3 parts of epoxy additives; and 0.01-2 parts of aniline black. The invention can significantly improve the weld mark strength and weld mark strength retention rate of the polyamide molding composition by compounding the epoxy additives and aniline black.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, in particular to a polyamide molding composition and a preparation method and application thereof. Background Art

[0002] Polyamide resin has high rigidity, good toughness and good heat deformation temperature, and its formability and chemical resistance are relatively good. Therefore, it has been widely used as internal load-bearing parts or external structural parts in rail transportation, consumer electronics, power tools and other fields.

[0003] With the continuous development and progress of society, the application scenarios of replacing steel with plastic are gradually increasing, and the structural design of many products is gradually developing in the direction of complexity and diversification. Some products are poured from multiple gates, and the structural design will cause the material flow process to have diversion and confluence, so higher requirements are also put forward for the strength of the weld mark of the material. If the material has high strength, but the weld mark strength is not good, it will also cause the product to crack during falling and long-term load.

[0004] In terms of material mechanical properties, there are many literatures or patents on the research of tensile strength; however, there are few reports focusing on the strength of material weld marks. Summary of the invention

[0005] The object of the present invention is to provide a polyamide molding composition having the advantage of high weld line strength.

[0006] Another object of the present invention is to provide a preparation method and application of the polyamide molding composition.

[0007] The present invention is achieved through the following technical solutions:

[0008] A polyamide molding composition, comprising the following components in parts by weight:

[0009] Polyamide 60 parts;

[0010] Epoxy additive 0.05-3 parts;

[0011] Aniline black 0.01-2 parts.

[0012] Preferably, the following components are included by weight:

[0013] Polyamide 60 parts;

[0014] Epoxy additive 0.2-1.7 parts;

[0015] Aniline black 0.15-0.9 parts.

[0016] More preferably, the following components are included by weight:

[0017] Polyamide 60 parts;

[0018] Epoxy additive 0.4-1.2 parts;

[0019] Aniline black 0.3-0.7 parts.

[0020] The epoxy auxiliary agent is selected from at least one of epoxy resin and a copolymer containing glycidyl methacrylate monomer; wherein the copolymer containing glycidyl methacrylate monomer is selected from at least one of ethylene-butyl acrylate-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, and ethylene-butyl acrylate-glycidyl methacrylate grafted polyolefin elastomer.

[0021] Preferably, the epoxy additive is selected from epoxy resin.

[0022] The aniline black is selected from at least one of oil-soluble aniline black, alcohol-soluble aniline black, and water-soluble aniline black, and oil-soluble aniline black is preferred. The CAS No. of the oil-soluble aniline black is 8005-02-5, the CAS No. of the alcohol-soluble aniline black is 11099-03-9, and the CAS No. of the water-soluble aniline black is 8005-03-6.

[0023] By weight, it also includes 0-100 parts of filler; the filler is selected from at least one of fibrous fillers and granular fillers; the fibrous filler is selected from at least one of glass fiber and carbon fiber; the granular filler is selected from at least one of alumina, carbon black, aluminosilicate clay, montmorillonite, zirconium phosphate, kaolin, calcium carbonate, diatomaceous earth, graphite, mica, silica, titanium dioxide, zeolite, talc, wollastonite, glass beads, and glass powder.

[0024] The polyamide is selected from at least one of aliphatic polyamides and semi-aromatic polyamides. The aliphatic polyamide is a polyamide formed by condensation of at least one aliphatic dicarboxylic acid and at least one aliphatic diamine and / or a polyamide formed by condensation of at least one amino acid or at least one lactam with itself, including at least one of PA46, PA56, PA510, PA66, PA610, PA612, PA1010, PA1012, PA1212, PA6, PA7, PA11, and PA12; the semi-aromatic polyamide is a polyamide formed by condensation of at least one aromatic dicarboxylic acid and at least one aliphatic diamine, and is selected from at least one of PA10T, PA10T1010, PA10T66, PA MXD6, PA MXD10, and PA66 / 6T; the polyamide is selected from aliphatic polyamides.

[0025] Whether to add 0-3 parts of antioxidants and lubricants can be determined based on actual needs.

[0026] The antioxidant may be a hindered phenol antioxidant, an alkali metal or alkaline earth metal hypophosphite, a phosphite antioxidant, etc.; the lubricant may be a higher fatty acid, a higher fatty acid metal salt, a higher fatty acid ester, or a higher fatty acid amide, etc.

[0027] The preparation method of the polyamide molding composition of the present invention comprises the following steps: uniformly mixing all components except filler, feeding the components into a twin-screw extruder through a main feeding port for extrusion granulation, wherein the screw aspect ratio is 36-52:1, the screw barrel temperature range is 180-320°C, the rotation speed is 200-700rpm, and the filler is fed from the side to obtain the polyamide molding composition.

[0028] This patent focuses on protecting a polyamide composition with high weld mark strength, which can be more widely used as internal force-bearing parts or external structural parts in the fields of rail transportation, consumer appliances, power tools, etc. The invention has the following beneficial effects:

[0029] The present invention can significantly improve the weld mark strength of the polyamide molding composition by compounding the epoxy additive and aniline black. The filled and reinforced polyamide molding composition should meet the requirements of weld mark strength ≥70MPa and weld mark strength retention rate ≥50%. The unfilled polyamide molding composition should meet the requirements of weld mark strength retention rate ≥80%. DETAILED DESCRIPTION

[0030] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0031] The sources of raw materials used in the embodiments and comparative examples are as follows:

[0032] PA66: PA66 U4800 NC01, INVISTA, USA;

[0033] PA6: PA6 M2800, Xinhui Meida;

[0034] PA610: PA610 F120, Shandong Guangyin;

[0035] PA1010: 3 RILSAN TMFO F, Arkema, France;

[0036] PAMXD6: INGOO-MXD6, Shanghai Yinggu;

[0037] PA66 / 6T: C1504T, Shandong Guangyin; Epoxy additive A: Epoxy resin, YD-019, Guodu Chemical;

[0038] Epoxy additive B: ethylene-butyl acrylate-glycidyl methacrylate copolymer, PTW, DuPont, USA;

[0039] Epoxy additive C: ethylene-methyl acrylate-glycidyl methacrylate copolymer: AX8900, Arkema, France;

[0040] Epoxy additive D: Ethylene-butyl acrylate-glycidyl methacrylate grafted polyolefin elastomer: SOG-03, Jiangsu Jiayirong.

[0041] Fiberglass: ECS10-03-568H, Jushi, China;

[0042] Wollastonite: HQ-1250, Dalian Global Minerals Co., Ltd.;

[0043] Oil-soluble aniline black: NUBIAN® BLACK TN-870, Oriental Chemical Co., Ltd., Japan;

[0044] Alcohol-soluble aniline black: Solvent Black 5, Hubei Jusheng Technology Co., Ltd.;

[0045] Water-soluble aniline black: Acid Black 2, Hubei Jusheng Technology Co., Ltd.;

[0046] The preparation method of the polyamide molding composition of the embodiments and comparative examples is as follows: the other components except the filler are mixed uniformly, and the components are fed into a twin-screw extruder through the main feeding port for extrusion granulation. The screw aspect ratio is 40:1, the barrel temperature segmentation is 270 / 270 / 260 / 250 / 240 / 240 / 240 / 250 / 260°C, and the screw speed is 350 rpm. If glass fiber or talcum powder is side fed, a polyamide molding composition is obtained.

[0047] Various test methods:

[0048] (1) Tensile strength: The polyamide composition was injected from one side and molded into ISO tensile test specimens. The test specimens were conditioned in a standard laboratory environment of 23°C and 50% RH for 24 hours and then the tensile strength was tested in accordance with ISO-527-2:2012.

[0049] (2) Weld mark strength: The polyamide composition is injected from both sides simultaneously and molded into ISO tensile test specimens. The weld line converges in the middle of the tensile test specimens. The test specimens are conditioned in a standard laboratory environment of 23°C and 50% RH for 24 hours and then the weld mark strength is tested in accordance with ISO-527-2:2012 standard.

[0050] (3) Weld strength retention rate = weld mark strength / tensile strength.

[0051] Table 1: Contents of components (parts by weight) and test results of polyamide molding compositions of Examples 1-7

[0052] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 PA66 60 60 60 60 PA6 60 PA610 60 PA1010 60 Fiberglass 30 30 30 30 30 30 30 Epoxy Additive A 0.6 0.6 0.6 0.6 0.05 0.2 0.4 Oil soluble aniline black 0.4 0.4 0.4 0.4 0.01 0.15 0.3 Tensile strength / MPa 193 188 179 170 190 192 192 Weld mark strength / MPa 121 117 105 101 96 101 105 Weld strength retention rate / % 62.7 62.2 58.7 59.4 51.5 52.6 54.7

[0053] It can be seen from Examples 1-4 that the weld mark strength and weld mark strength retention rate of PA66 and PA6 are higher.

[0054] Table 2: Content (parts by weight) of each component in the polyamide molding composition of Examples 8-15 and test results

[0055] Example 8 Example 9 Example 10 Embodiment 11 Example 12 Embodiment 13 Embodiment 14 Embodiment 15 PA66 60 60 60 60 60 60 60 60 Fiberglass 30 30 30 30 30 30 Wollastonite 30 Epoxy Additive A 1.2 1.7 3 0.8 0.8 Epoxy additive B 0.6 Epoxy Additive C 0.6 Epoxy additive D 0.6 Oil soluble aniline black 0.7 0.9 2 0.4 0.4 0.4 0.5 0.5 Tensile strength / MPa 189 186 184 185 183 186 97 86 Weld mark strength / MPa 108 99 92.5 110 109 106 89 85 Weld strength retention rate / % 57.1 53.2 51.3 59.5 59.6 57.0 91.8 98.8

[0056] It can be seen from Examples 1 / 5-10 that under the preferred ratio, the weld mark strength and weld mark strength retention rate are higher.

[0057] It can be seen from Examples 1 / 11-13 that the epoxy auxiliary agent is preferably epoxy resin, which has higher weld mark strength and weld mark strength retention rate.

[0058] It can be seen from Example 1 and Comparative Example 1 / 3 that the compounding of epoxy additive and aniline black can significantly improve the weld mark strength and weld mark strength retention rate.

[0059] Table 3: Content of each component (parts by weight) and test results of polyamide molding compositions of Examples 16-19

[0060] Example 16 Embodiment 17 Embodiment 18 Embodiment 19 PA66 60 60 PAMXD6 60 P PA66 / 6T 60 Fiberglass 30 30 30 30 Epoxy Additive A 0.6 0.6 0.6 0.6 Oil soluble aniline black 0.4 0.4 Alcohol soluble aniline black 0.4 Water soluble aniline black 0.4 Tensile strength / MPa 185 178 200 190 Weld mark strength / MPa 110 104.5 108 100 Weld strength retention rate / % 59.5 58.7 54.0 52.6

[0061] It can be seen from Examples 1 / 16-17 that oil-soluble aniline black is preferred.

[0062] Table 4: Content of each component (parts by weight) and test results of the comparative polyamide molding composition

[0063] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 PA66 60 60 60 60 60 60 60 60 Fiberglass 30 30 30 30 30 30 30 Epoxy Additive A 0.6 0.6 0.01 3.5 4 Oil soluble aniline black 2.5 0.4 0.4 0.4 3 Tensile strength / MPa 196 188 193 194 183 168 192 86 Weld mark strength / MPa 89 84 85 87 85 66 81 67 Weld strength retention rate / % 45.4 44.7 44.0 44.8 46.4 39.3 42.3 77.9

[0064] It can be seen from comparative examples 1 / 2 / 7 that the improvement of weld mark strength is not obvious without adding oil-soluble aniline black, and when the amount of oil-soluble aniline black added is too high, the weld mark strength will decrease.

[0065] It can be seen from Comparative Examples 3 / 4 / 5 that if the amount of epoxy additive added is insufficient, the weld mark strength will not be significantly improved; if the amount of epoxy additive added is too high, the weld mark strength will decrease instead.

[0066] It can be seen from Comparative Example 6 that if the amount of epoxy additive and oil-soluble aniline black added is too high, the weld mark strength decreases significantly.

[0067] It can be seen from Example 15 and Comparative Example 8 that when no filler is added and no epoxy additive and aniline black are added, the weld mark strength retention rate cannot reach more than 80%.

Claims

1. A polyamide molding composition, characterized in that By weight, it includes the following components: Polyamide 60 parts; Epoxy additive 0.05-3 parts; Aniline black 0.01-2 parts; The aniline black is selected from oil-soluble aniline black; The epoxy auxiliary agent is selected from at least one of epoxy resin and a copolymer containing glycidyl methacrylate monomer.

2. The polyamide molding composition according to claim 1, characterized in that By weight, it includes the following components: Polyamide 60 parts; Epoxy additive 0.2-1.7 parts; Aniline black 0.15-0.9 parts.

3. The polyamide molding composition according to claim 2, characterized in that By weight, it includes the following components: Polyamide 60 parts; Epoxy additive 0.4-1.2 parts; Aniline black 0.3-0.7 parts.

4. The polyamide molding composition according to any one of claims 1 to 3, characterized in that The copolymer containing glycidyl methacrylate monomer is selected from at least one of ethylene-butyl acrylate-glycidyl methacrylate copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, and ethylene-butyl acrylate-glycidyl methacrylate grafted polyolefin elastomer.

5. The polyamide molding composition according to any one of claims 1 to 3, characterized in that The epoxy auxiliary agent is selected from epoxy resin.

6. The polyamide molding composition according to any one of claims 1 to 3, characterized in that By weight, it also includes 0-30 parts of filler; the filler is selected from at least one of fibrous fillers and granular fillers; the fibrous filler is selected from at least one of glass fiber and carbon fiber; the granular filler is selected from at least one of alumina, carbon black, aluminosilicate clay, montmorillonite, zirconium phosphate, kaolin, calcium carbonate, diatomaceous earth, graphite, mica, silica, titanium dioxide, zeolite, talc, wollastonite, glass beads, and glass powder.

7. The polyamide molding composition according to any one of claims 1 to 3, characterized in that The polyamide is selected from at least one of aliphatic polyamide and semi-aromatic polyamide. The aliphatic polyamide is a polyamide formed by condensation of at least one aliphatic dicarboxylic acid and at least one aliphatic diamine and / or a polyamide formed by condensation of at least one amino acid or at least one lactam with itself, including at least one of PA46, PA56, PA510, PA66, PA610, PA612, PA1010, PA1012, PA1212, PA6, PA7, PA11, and PA12; the semi-aromatic polyamide is a polyamide formed by condensation of at least one aromatic dicarboxylic acid and at least one aliphatic diamine, and is selected from at least one of PA10T, PA10T1010, PA10T66, and PA66 / 6T.

8. The polyamide molding composition according to any one of claims 1 to 3, characterized in that The polyamide is selected from at least one of PA MXD6 and PA MXD10.

9. The polyamide molding composition according to any one of claims 1 to 3, characterized in that The polyamide is selected from aliphatic polyamide.

10. The polyamide molding composition according to any one of claims 1 to 3, characterized in that By weight, the invention also includes 0-3 parts of auxiliary agents, wherein the auxiliary agents are selected from antioxidants and lubricants.

11. The method for preparing the polyamide molding composition according to claim 6, characterized in that: The method comprises the following steps: uniformly mixing the components except the filler, feeding the components into a twin-screw extruder through a main feeding port for extrusion granulation, wherein the screw aspect ratio is 36-52:1, the screw barrel temperature range is 180-320°C, the rotation speed is 200-700rpm, and the filler is fed from the side to obtain a polyamide molding composition.

12. Use of the polyamide molding composition according to any one of claims 1 to 10, characterized in that Used for preparing internal stress-bearing parts or external structural parts of rail transit, internal stress-bearing parts or external structural parts of consumer electrical appliances, and internal stress-bearing parts or external structural parts of power tools.