A PBT composite material, its preparation method and application

Abstract

The present invention discloses a PBT composite material, which comprises, by weight parts, PBT resin, glass fiber, azine coloring agent, and epoxy resin. By adopting the compounding of azine molecules and epoxy resin, the present invention can effectively improve the defect of floating fiber, and can also improve the surface glossiness and mechanical properties.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly relates to a PBT composite material, a preparation method thereof, and an application thereof. Background Art

[0002] PBT is an engineering plastic with excellent properties, having many advantages such as high mechanical strength, good fatigue resistance, good dimensional stability, and good solvent resistance, and is widely used in industries such as electronic appliances, household appliances, automobiles, and textiles.

[0003] PBT is a semi-crystalline polymer with a relatively fast crystallization rate and good crystallization properties, and thus has good performance in molding processing. Usually, higher material performance requirements are imposed in product applications, so various modifying additives, fillers, etc. are blended to improve the properties of PBT materials and broaden the application fields. Among them, in order to improve the properties of PBT materials, blending glass fiber to improve its mechanical properties is a common modification formula in PBT materials. However, in the actual processing process, since glass fiber is a shaped inorganic substance with poor compatibility with polymer resin, inconsistent fluidity, and poor binding ability between resin and glass fiber, the situation of glass fiber precipitation and leakage often occurs. The white glass fiber floats on the surface during the filling and flowing process of the polymer resin melt, and after condensation and molding, it will form radial white marks on the surface of the plastic part, and cause the surface of the part to be rough and uneven, affecting the surface gloss.

[0004] In order to solve the above problems and obtain a glass fiber-reinforced PBT material with better appearance, other resins with higher fluidity (such as PC, PET, etc.) are usually blended to improve fluidity and thus improve the phenomenon of glass fiber exposure. For example, the prior art (CN113845760B) improves the appearance by adding low-crystalline resin PET to glass fiber-reinforced PBT. However, after blending high-flow resin, the mechanical properties of the material will generally be reduced as a whole. Summary of the Invention

[0005] The purpose of the present invention is to provide a PBT composite material with less floating fibers, high surface gloss, and good mechanical properties, which is suitable for preparing parts related to new energy vehicle batteries.

[0006] The present invention is achieved by the following technical solutions:

[0007] A PBT composite material, by weight, comprises the following components:

[0008] 80 parts of PBT resin;

[0009] 5 - 80 parts of glass fiber;

[0010] 0.5 - 10 parts of azine molecules and epoxy resin;

[0011] Among them, the weight ratio range of the azine molecule to the epoxy resin is 1:(1 - 10).

[0012] In the technical solution of the present invention, the addition amount of glass fiber can be 5 parts, 10 parts, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, etc.

[0013] Preferably, the weight ratio range of the azine molecule to the epoxy resin is 1:(4 - 8).

[0014] The azine molecule mainly refers to an unsaturated heterocyclic compound containing one or several nitrogen atoms. For example, the azine compound can be a pyridine or azobenzene molecule containing one nitrogen atom; or a pyridazine, pyrimidine, pyrazine or diazine or dibenzodiazine molecule containing two nitrogen atoms; or a triazine or tribenzotriazine molecule containing three nitrogen atoms, a tetrazine or tetrabenzotriazine molecule containing four nitrogen atoms, a pentazine or pentabenzotriazine molecule containing five nitrogen atoms; or an oxazine or oxazoline molecule containing one nitrogen atom and one oxygen atom; or a thiazine or thiazole molecule containing one sulfur atom and one nitrogen atom.

[0015] The azine molecule is commonly used as a dyeing agent for composite materials. It contains (hetero)aniline functional groups. The epoxy groups in the epoxy resin have good reactivity and affinity with the nitrogen-containing functional groups in the PBT resin and the azine molecule, which can reduce the crystallization temperature of the material and improve the surface fiber floating of the product. However, due to the relatively high molecular weight of the epoxy resin and the relatively small azine molecule, small molecule agglomeration may occur in the system. By adjusting the epoxy equivalent of the epoxy resin, the ratio of the azine molecule and the molecular weight of the dyeing agent molecule in the PBT composite material, this compounding scheme can improve the mixing uniformity among the three, effectively avoid the agglomeration of color powder, and obtain materials with better surface gloss and excellent mechanical properties.

[0016] The present invention does not particularly limit the azine molecule. In a specific embodiment provided by the present invention, the azine molecule is selected from at least one of 3,7-diamino-5-phenylphenazinium chloride, [4-[(4-dimethylaminophenyl)-(4-methylaminophenyl)methylene]-1-cyclohexane-2,5-diene]-dimethyl azo, Solvent Black 1, Solvent Black 3, Solvent Black 5, Solvent Black 7, Solvent Black 17, Solvent Black 27. Preferably, the azine molecule is selected from 3,7-diamino-5-phenylphenazinium chloride.

[0017] For the purpose of improving the tensile strength and reducing the surface fiber floating, preferably, the epoxy equivalent of the epoxy resin ranges from 180 to 820 g / eq, more preferably from 220 to 500 g / eq. The epoxy equivalent is tested in accordance with Standard GB / T 4612-2008.

[0018] The present invention has no particular limitation on the intrinsic viscosity of the PBT resin. The intrinsic viscosity of the PBT resin commonly used in the art ranges between 0.8 and 1.0 dl / g. The intrinsic viscosity is tested in accordance with Standard GB / T 14190-2017.

[0019] The present invention may also optionally incorporate other additives such as antioxidants, lubricants, fillers, etc. The antioxidants may be: 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 2,5-di-tert-butyl-4-hydroxybenzyl dimethylamine; diethyl 3,5-di-tert-butyl-4-hydroxybenzyl phosphate; stearyl 3,5-di-tert-butyl-4-hydroxybenzyl phosphate; 3,5-di-tert-butyl-4-hydroxyphenyl-3,5-distearyl-thiotriazolylamine; 2,6-di-tert-butyl-4-hydroxymethylphenol; 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylglycidyl allyl ether)-1,3,5-triazine; N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamide); N,N'-bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine; octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; pentaerythrityl-tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; triethylene glycol bis[3-(3,5-dimethyl-4-hydroxyphenyl)propionate]; diethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]; 2,2'-thiobisethyl-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], etc.

[0020] The lubricants may be at least one of stearate lubricants, fatty acid lubricants, and stearic acid ester lubricants; the stearate lubricants are selected from at least one of calcium stearate, magnesium stearate, and zinc stearate; the fatty acid lubricants are selected from at least one of fatty acids, fatty acid derivatives, and fatty acid esters; the stearic acid ester lubricants are selected from at least one of pentaerythritol stearate.

[0021] The fillers may be talc, mica, calcium carbonate, etc.

[0022] The preparation method of the PBT composite material of the present invention comprises the following steps: adding each component into a twin-screw extruder, the temperature range of the twin-screw extruder is 200 - 250 °C, the rotation speed is 250 - 400 revolutions per minute, and granulating to obtain the PBT composite material.

[0023] The application of the PBT composite material of the present invention is used for preparing new energy vehicle battery parts, such as battery bases, etc.

[0024] The present invention has the following beneficial effects

[0025] By adding epoxy resin and azine molecules to the PBT composite material and optimizing the ratio of the compounded epoxy resin and azine molecules, the present invention can improve the appearance of the PBT composite material (improve fiber floating and increase surface glossiness) while having relatively high mechanical properties. Embodiment

[0026] The present invention will be 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 do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made. These all belong to the protection scope of the present invention.

[0027] The sources of the raw materials used in the present invention are as follows:

[0028] PBT resin A: intrinsic viscosity 0.82 dl / g, PBT GX112, Sinopec Yizheng Chemical Fiber Co., Ltd.;

[0029] PBT resin B: intrinsic viscosity 0.67 dl / g, PBT GX110, Sinopec Yizheng Chemical Fiber Co., Ltd.;

[0030] PBT resin C: intrinsic viscosity 1.15 dl / g, PBT BM433, Sinopec Yizheng Chemical Fiber Co., Ltd.;

[0031] Azine molecule A: 3,7-diamino-5-phenylphenazinium chloride, CAS No. 81-93-6, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0032] Azine molecule B: [4-[(4-dimethylaminophenyl)-(4-methylaminophenyl)methylene]-1-cyclohexane-2,5-diene]-dimethyl azo, CAS 8004-87-3, Taizhou Dongbang Fine Chemical Co., Ltd.;

[0033] Azine molecule C: Solvent Black 7, CAS 8005-02-5, Shanghai Merck Chemical Technology Co., Ltd.;

[0034] Azine molecule D: Solvent Black 1, CAS 13007-86-8, Hubei Wande Chemical Industry Co., Ltd.;

[0035] Azine molecule E: Solvent Black 3, CAS 4197-25-5, Shanghai Merck Chemical Technology Co., Ltd.;

[0036] Epoxy resin A: Epoxy equivalent 230-280 g / eq, CYD-E42;

[0037] Epoxy resin B: Epoxy equivalent 450-500 g / eq, CYD-011;

[0038] Epoxy resin C: Epoxy equivalent 184-194 g / eq, CYD-128;

[0039] Epoxy resin D: Epoxy equivalent 710-815 g / eq, CYD-014U;

[0040] Glass fiber: ECS11-4.5-534A, Jushi Co., Ltd.

[0041] Preparation method of PBT composites in examples and comparative examples: Add each component to a twin-screw extruder. The temperature of the twin-screw extruder is set as follows: the temperature of zone 1 is 220-240 °C, the temperature of zone 2 is 230-245 °C, the temperature of zone 3 is 235-245 °C, the temperature of zone 4 is 235-250 °C, the temperature of zone 5 is 220-240 °C, the temperature of zone 6 is 220-240 °C, the temperature of zone 7 is 210-230 °C, the temperature of zone 8 is 200-220 °C, the temperature of zone 9 is 200-220 °C, the temperature of zone 10 is 220-240 °C, and the rotation speed is 250-400 revolutions per minute. Granulate to obtain PBT composites.

[0042] Testing methods for each item:

[0043] (1) Surface fiber floating: Select the same position on the injection molded square plate, use a two-dimensional image measuring instrument to magnify 100 times, and count the number of visible surface fiber floating within the same area of the field of view.

[0044] (2) Surface glossiness: Test according to standard GB / T 8807-1988, 60° using a surface glossiness tester.

[0045] (3) Tensile strength: Test according to standard ISO 527-2-2012, with a rate of 10 mm / min.

[0046] Table 1: Component contents (parts by weight) and test results of PBT composites in Examples 1-7

[0047] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 PBT-A 80 80 80 80 80 PBT-B 80 PBT-C 80 Glass fiber 30 5 80 30 30 30 30 Azine molecule A 2.5 0.25 5 1 0.72 0.56 0.45 Epoxy resin A 2.5 0.25 5 4 4.28 4.44 4.5 Surface floating fiber, root 10 5 21 5 3 7 12 Surface gloss, % 65.6 75.5 51.9 77.6 86.2 72.3 61.8 Tensile strength, MPa 110 65 145 115 129 120 115

[0048] As can be seen from Examples 1 / 4 - 7, when the weight ratio range of the preferred azine molecules to the epoxy resin is used, the surface floating fibers are the least, and the gloss and tensile strength are higher.

[0049] Table 2: Component contents (parts by weight) and test results of PBT composites in Examples 8 - 12

[0050] Example 8 Example 9 Example 10 Example 11 PBT-A 80 80 80 80 Glass fiber 30 30 30 30 Azine molecule B 2.5 Azine molecule C 2.5 Azine molecule D 2.5 Azine molecule E 2.5 Epoxy resin A 2.5 2.5 2.5 2.5 Surface floating fiber, root 13 15 12 18 Surface gloss, % 61.9 58.7 57.9 63.1 Tensile strength, MPa 108 103 101 97

[0051] As can be seen from Examples 1 / 8 - 11, 3,7 - diamino - 5 - phenylphenazinium chloride is preferred.

[0052] Table 3: Component contents (parts by weight) and test results of PBT composites in Examples 12 - 14

[0053] Example 12 Example 13 Example 14 PBT-A 80 80 80 Glass fiber 30 30 30 Azine molecule A 2.5 2.5 2.5 Epoxy resin B 2.5 Epoxy resin C 2.5 Epoxy resin D 2.5 Surface floating fiber, root 11 13 22 Surface gloss, % 57.5 67.3 54.5 Tensile strength, MPa 105 95 100

[0054] As can be seen from Examples 1 / 12 - 14, when the epoxy equivalent of the preferred epoxy resin is used, the tensile strength is higher and the surface floating fibers are fewer.

[0055] Table 4: Component contents (parts by weight) and test results of PBT composites in comparative examples

[0056] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 PBT-A 80 80 80 80 80 Glass fiber 30 30 30 30 30 Azine molecule A 2.5 0.3 4.7 0.1 Epoxy resin A 2.5 4.7 0.3 0.1 Surface floating fiber, root 43 51 22 38 40 Surface gloss, % 35.6 12.8 50.6 40.0 38.9 Tensile strength, MPa 76 93 95 65 88

[0057] As can be seen from Comparative Examples 1 - 5, the compounding of azine molecules and epoxy resin is a key factor in this patent. When the two are not within the scope of the present invention, the number of surface floating fibers is large, and the gloss and tensile strength are low.

[0058] As can be seen from the above examples and comparative examples, the PBT composite material of this application has the advantages of having less than 25 surface floating fibers (according to the test method of this application), a surface gloss greater than 50%, and a tensile strength greater than 60 MPa, and is suitable for the requirements between new energy vehicle batteries.

Claims

1. A PBT composite material, characterized in that, by weight, it comprises the following components: 80 parts of PBT resin; 5 - 80 parts of glass fiber; 0.5 - 10 parts of azine molecule and epoxy resin; wherein, the weight ratio range of the azine molecule to the epoxy resin is 1:(1 - 10); the said azine molecule is selected from at least one of 3,7 - diamino - 5 - phenylphenazinium chloride, [4 - [(4 - dimethylaminophenyl)-(4 - methylaminophenyl)methylene]-1 - cyclohexane - 2,5 - diene]-dimethyl azo, Solvent Black 1, Solvent Black 3, Solvent Black 5, Solvent Black 7, Solvent Black 17, Solvent Black 27; the epoxy equivalent range of the said epoxy resin is 180 - 820 g / eq.

2. The PBT composite material according to claim 1, characterized in that, the weight ratio range of the azine molecule to the epoxy resin is 1:(4 - 8).

3. The PBT composite material according to claim 1, characterized in that, the said azine molecule is selected from 3,7 - diamino - 5 - phenylphenazinium chloride.

4. The PBT composite material according to claim 1, characterized in that, the epoxy equivalent range of the said epoxy resin is 220 - 500 g / eq.

5. The PBT composite material according to claim 1, characterized in that, the intrinsic viscosity range of the PBT resin is 0.8 - 1.0 dl / g, and the intrinsic viscosity is tested according to standard GB / T14190 - 2017.

6. The preparation method of the PBT composite material according to any one of claims 1 - 5, characterized in that, it comprises the following steps: Adding each component into a twin - screw extruder, the temperature range of the twin - screw extruder is 200 - 250 °C, the rotation speed is 250 - 400 revolutions per minute, and granulating to obtain the PBT composite material.

7. The application of the PBT composite material according to any one of claims 1 - 5, characterized in that, it is used for preparing new energy vehicle battery parts.