Glass fiber reinforced polyester alloy as well as preparation method and application thereof

Abstract

The invention discloses a glass fiber reinforced polyester alloy which comprises the following components in parts by weight: 10-90 parts of PBT (polybutylene terephthalate) resin; 10 to 40 parts of PET resin; 1 to 50 parts of glass fiber; 0.1-1 part of a warping improver; the warping improver is a compound of a chemical foaming agent and a lubricant in a weight ratio of (3-5): 1. By means of the warping improving agent, the defect that glass fiber reinforced polyester alloy in the prior art is prone to warping can be remarkably overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly to a glass fiber reinforced polyester alloy and its preparation method and application. Background Art

[0002] In the field of modified plastics, the warpage problem of glass fiber reinforced materials has always been a technical bottleneck restricting the application of materials. The warpage deformation of glass fiber reinforced materials is mainly attributed to the uneven dispersion of glass fibers in the flow and vertical directions of the product. Therefore, how to fundamentally achieve the uniform dispersion of glass fibers is an important way to improve the warpage deformation of glass fiber reinforced materials. As is well known, glass fiber reinforced polymer materials can greatly improve the rigidity and dimensional stability of materials and are widely used in the modified plastics industry. However, due to the certain aspect ratio of glass fibers, which shows a typical uneven distribution in the flow and vertical directions of the product, the polymer forms epitaxial crystallization on the surface of the glass fiber, and the whole part also shows inconsistent shrinkage in the transverse, longitudinal, and thickness directions, ultimately resulting in warpage deformation of the part. And the internal stress generated therefrom also affects the structure of the product. This problem is the most common problem of glass fiber reinforced polymer materials, which greatly restricts the use of glass fibers and the popularization of modified materials. Summary of the Invention The purpose of the present invention is to overcome the above technical defects and provide a glass fiber reinforced polyester alloy with low warpage.

[0003] The present invention is achieved by the following technical solutions: A glass fiber reinforced polyester alloy, by weight, comprises the following components: 10 - 90 parts of PBT resin; 10 - 40 parts of PET resin; 1 - 50 parts of glass fiber; 0.1 - 1 part of warpage improver; The warpage improver is a compound of a chemical foaming agent and a lubricant with a weight ratio of (3 - 5):1.

[0004] The chemical foaming agent is selected from at least one of sodium bicarbonate, azodicarbonamide, and N,N'-dinitrosopentamethylenetetramine.

[0005] Preferably, the chemical foaming agent is selected from N,N'-dinitrosopentamethylenetetramine.

[0006] Optionally, the lubricant is selected from at least one of zinc stearate, calcium stearate, and pentaerythritol stearate.

[0007] The glass fiber can be short cut fiber or continuous glass fiber. The present invention has no limitation on the average diameter and average length of the glass fiber. The average diameter range of commercially available glass fibers is 7 - 13 microns, which can achieve the purpose of the present invention.

[0008] The present invention has no special requirements for the parameters of PBT resin and PET resin. Through experiments, it is found that the relative viscosity of PBT resin is 0.7 - 1.3, and the relative viscosity of the PET resin is 0.7 - 1.3. The test standard is ISO 1628.5.

[0009] In the glass fiber reinforced polyester alloy of the present invention, the percentage by weight of PBT resin in the alloy ranges from 10 - 89wt%, the percentage by weight of PET resin in the alloy ranges from 6.7 - 78wt%, and the percentage by weight of the warpage improver in the alloy ranges from 0.06 - 0.7wt%.

[0010] By weight, it further includes 0 - 1 part of heat stabilizer, and the heat stabilizer is selected from phenolic heat stabilizers and thiosulfate stabilizers.

[0011] By weight, it further includes 0 - 1 part of light stabilizer, and the light stabilizer is selected from hindered amine light stabilizers.

[0012] The preparation method of the glass fiber reinforced polyester alloy of the present invention includes the following steps: according to the ratio, mix the components except glass fiber evenly, enter through the main feeding port into a twin - screw extruder for extrusion granulation, and glass fiber enters through the side feeding port to obtain the glass fiber reinforced polyester alloy. The rotation speed range of the screw is 400 - 600 revolutions per minute, and the barrel temperature range is 170 - 280 °C.

[0013] The application of the glass fiber reinforced polyester alloy of the present invention is used for preparing parts with high flatness.

[0014] The present invention has the following beneficial effects: The present invention can minimize the internal stress of the material to the greatest extent through the lubricant and achieve uniformity in all directions. By utilizing the combined action of the foaming agent and the lubricant in the material, the problem of different flow and vertical direction shrinkage rates caused by the orientation distribution of glass fiber in the material is reduced to the greatest extent, and the internal stress of the material is reduced. The micro - bubbles brought about by the slight foaming of the foaming agent can effectively play a role in structural support and achieve uniformity in different directions. The glass fiber reinforced polyester alloy of the present invention significantly reduces the warpage deformation of the material and achieves low warpage. Specific Embodiments

[0015] The following will explain the present invention in detail 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 deformations and improvements can be made. These all belong to the protection scope of the present invention.

[0016] The sources of the raw materials used in the present invention are as follows: PBT resin A: relative viscosity 0.82, produced by Yangzi Petrochemical, typical grade GX112; PBT resin B: relative viscosity 0.98, produced by Yangzi Petrochemical, typical grade GX121; PET resin A: relative viscosity 0.68, produced by Yangzi Petrochemical, typical grade FG600; PET resin B: relative viscosity 0.68, produced by China Resources Chemicals (Zhuhai), typical grade CR-7702; Glass fiber: produced by Chongqing Composites Co., Ltd., grade ECS301HP-03-H; Sodium bicarbonate: supplied by Sinopharm Group, NaHCO3; Azodicarbonamide: CAS: 123-77-3, molecular formula: C2H4N4O2, supplied by Shanghai Macklin Biochemical Co., Ltd.; N,N’-Dinitrosopentamethylenetetramine: CAS: 101-25-7, molecular formula: C5H 10 N6O2, supplied by Shanghai Merck Chemical Technology Co., Ltd.; Zinc stearate: ZnSt, CAS: 557-05-1, supplied by Jiangxi Hongyuan Chemical Co., Ltd.; Calcium stearate CaSt, CAS: 1592-23-0, supplied by Anhui Ruihua New Materials Co., Ltd.; Pentaerythritol stearate: PETS-AP, supplied by Faji Co., Ltd.; Heat stabilizer: antioxidant 1010, supplied by Yingkou Fengguang Co., Ltd.

[0017] Preparation method of glass fiber reinforced polyester alloy in examples and comparative examples: According to the ratio, mix the components except glass fiber evenly, and feed them into a twin-screw extruder through the main feed port for extrusion granulation. Glass fiber enters through the side feed port to obtain the glass fiber reinforced polyester alloy. The rotation speed of the screw is 500 revolutions per minute, and the barrel temperature is set as follows: zone 1: 170 °C, zone 2: 190 °C, zone 3: 230 °C, zone 4: 260 °C, zone 5: 280 °C, zone 6: 280 °C, zone 7: 280 °C, zone 8: 260 °C, zone 9: 260 °C.

[0018] Test methods for each item: (1) Warpage amount: Inject the material through the center single-point gate for injection molding. The size of the rectangular sample is 275 mm × 200 mm × 2 mm. Fix the center position of the sample horizontally using a tooling fixture, and measure the horizontal positions of the four corners of the sample using a laser rangefinder. Then place the tooling fixture and the sample in an environmental chamber at 80 °C for 48 hours, and then take them out to measure the horizontal positions of the four corners, and record the sum of the displacement amounts at each position, with the unit of cm. The smaller the value, the smaller the warpage amount, and the more obvious the low warpage characteristics of the material.

[0019] Table 1: Component contents (parts by weight) and test results of glass fiber reinforced polyester alloys in Examples 1-7 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 PBT Resin A 10 50 89 50 50 50 PBT Resin B 30 PET Resin A 40 20 10 20 20 20 PET Resin B 30 Glass Fiber 10 20 50 20 20 20 30 N,N’-Dinitrosopentamethylenetetramine 0.075 0.3 0.25 Azodicarbonamide 0.3 0.45 Sodium Bicarbonate 0.75 0.3 Zinc Stearate 0.025 0.15 Calcium Stearate 0.1 0.1 0.1 0.05 Pentaerythritol Stearate 0.25 Heat Stabilizer 0.2 Warpage (cm) 0.40 0.32 0.30 0.20 0.25 0.25 0.27 It can be seen from Examples 2 / 4 / 5 that the chemical blowing agent is preferably N,N'-dinitrosopentamethylenetetramine.

[0020] Table 2: Component contents (parts by weight) and test results of glass fiber reinforced polyester alloys in Comparative Examples Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 PBT 70 50 50 PET 70 20 20 Glass Fiber 20 20 20 20 Azodicarbonamide 0.3 0.3 0.2 0.35 Calcium Stearate 0.1 0.1 0.2 0.05 Warpage (cm) 1.30 1.08 1.12 1.34 It can be seen from Comparative Examples 1 / 2 that when PBT or PET is selected alone, the warpage is high and the actual use requirements cannot be met.

[0021] It can be seen from Comparative Examples 3 / 4 that if the weight ratio of the chemical blowing agent to the lubricant is not within the scope of the present invention, the warpage resistance is poor and the actual use requirements cannot be met.

Claims

1. A glass fiber reinforced polyester alloy, characterized in that, By weight, it includes the following components: PBT resin 10-90 parts; PET resin 10-40 parts; Glass fiber 1-50 parts; Warpage improver 0.1-1 part; The warpage improving agent is a compound of a chemical foaming agent and a lubricant in a weight ratio of (3-5):

1.

2. The glass fiber reinforced polyester alloy according to claim 1, characterized in that, The chemical foaming agent is selected from at least one of sodium bicarbonate, azodicarbonamide and N,N'-dinitrosopentamethylenetetramine.

3. The glass fiber reinforced polyester alloy according to claim 2, wherein, The chemical foaming agent is selected from N,N'-dinitrosopentamethylenetetramine.

4. The glass fiber-reinforced polyester alloy according to claim 1, wherein The lubricant is selected from at least one of zinc stearate, calcium stearate and pentaerythritol stearate.

5. The glass fiber reinforced polyester alloy according to claim 1, characterized in that, The relative viscosity of the PBT resin is 0.7-1.3, the relative viscosity of the PET resin is 0.7-1.3, and the test standard is ISO 1628.

5.

6. The glass fiber reinforced polyester alloy according to claim 1, characterized in that, By weight, the invention further comprises 0-1 part of a heat stabilizer and / or 0-1 part of a light stabilizer, wherein the heat stabilizer is selected from at least one of a phenolic heat stabilizer and a thiosulfate stabilizer.

7. The glass fiber reinforced polyester alloy according to claim 6, characterized in that, The light stabilizer is selected from hindered amine light stabilizers.

8. The preparation method of the glass fiber reinforced polyester alloy according to any one of claims 1-7, characterized in that, The method comprises the following steps: according to the proportion, each component except glass fiber is uniformly mixed, and the components are fed into a twin-screw extruder through a main feeding port for extrusion granulation, and the glass fiber is fed through a side feeding port to obtain a glass fiber reinforced polyester alloy.

9. Use of the glass fiber reinforced polyester alloy according to any one of claims 1-7, characterized in that, Used to prepare high-flatness parts.