CN114806098A

CN114806098A - Low-warpage reinforced PBT (polybutylene terephthalate) material and preparation method thereof

Info

Publication number: CN114806098A
Application number: CN202110088224.2A
Authority: CN
Inventors: 晏伟; 王昕�; 周志峰; 何辉; 宗荣锋
Original assignee: Wuhan Shunwei Saite Engineering Plastics Co ltd
Current assignee: Wuhan Shunwei Saite Engineering Plastics Co ltd
Priority date: 2021-01-22
Filing date: 2021-01-22
Publication date: 2022-07-29

Abstract

The invention relates to a low-warpage reinforced PBT (polybutylene terephthalate) material which is prepared from the following raw materials in percentage by weight: 50-71% of PBT resin, 0-10% of a compatilizer, 0-3% of a toughening agent, 28-35% of reinforcing fiber and 1-2% of an auxiliary agent. The preparation method of the low-warpage reinforced PBT material is simple: the PBT resin is dried and mixed with the compatilizer, then the rest components are added and mixed uniformly, and finally the mixture is extruded with the chopped glass fibers in a melting extruder. Compared with the prior art, the low-warpage reinforced PBT material has the advantages of good dimensional thermal stability, low warpage and high impact, and is applied to bases of household appliances and automobile parts.

Description

Low-warpage reinforced PBT (polybutylene terephthalate) material and preparation method thereof

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a low-warpage reinforced PBT material and a preparation method thereof.

Background

Although the PBT resin is engineering plastic, the price is cheaper than general plastic, the comprehensive mechanical property is excellent, the PBT resin is high-temperature resistant and easy to flame retardant, the defects that nylon has unstable water absorption size and poor water absorption electrical property are particularly overcome, and the PBT resin is high-temperature resistant, good in size stability and very wide in application after being modified by glass fiber reinforcement.

The reinforced PBT has two defects, namely 1 that the surface of a product is easy to float fibers and the appearance is poor, and 2 that the product is easy to warp and not flat.

Aiming at the warping problem, a national invention patent [ CN201810799080.X ] submitted by Guangdong cis-distressed cis-inflammatory new material company Limited gives a scheme, ASA resin and a toughening agent styrene-methyl acrylate-glycidyl methacrylate copolymer are added to toughen the PBT/ASA resin, and the PBT/ASA resin can be compatibilized at the same time, and in addition, glass fiber is adopted, other fillers are not added, and the mechanical property is kept. Other fillers mainly include whisker, wollastonite, barium sulfate, mica, hollow and solid glass beads, talc and other spherical acicular platy fillers.

The market has reinforced flame-retardant PBT/ASA of domestic and foreign manufacturers, has low warpage, adopts PC AS flame-retardant reinforced PBT, and adopts AS or ABS or ASA (including AS and high rubber powder) AS non-flame-retardant reinforced PBT to reduce warpage. At the same time, a PTW or AX8900 toughening agent is added.

Disclosure of Invention

The invention provides a low-warpage reinforced PBT material and a preparation method thereof, aiming at solving the compatibility problem caused by adding amorphous resin into the existing low-warpage reinforced PBT.

The technical scheme for solving the technical problems is as follows: the low-warpage reinforced PBT material is characterized by comprising the following raw materials in percentage by weight: PBT resin

50-71%, 0-10% of compatilizer, 0-3% of flexibilizer, 28-35% of reinforcing fiber and 1-2% of auxiliary agent.

On the basis of the technical scheme, the invention can be further improved as follows.

Preferably, the PBT resin is 0.72 viscous.

Preferably, the compatibilizer is a bulk random copolymer of styrene, acrylonitrile, glycidyl methacrylate and a small amount of a fourth monomer, having an epoxy weight equivalent of 2%.

Preferably, the glass fiber is chopped alkali-free glass fiber, and the diameter of the glass fiber is 10um and 3mm long.

Preferably, the auxiliary agent is any one or a mixture of any more of hyperbranched resin, PE wax, pentaerythritol stearate, silicone, an antioxidant and a nucleating agent.

The invention also provides a method for preparing the low-warpage reinforced PBT material, which comprises the following steps: firstly, drying the PBT resin at the temperature of 115-125 ℃ for more than 4h, then taking the dried PBT resin and the compatilizer according to the corresponding weight percentage, uniformly stirring, adding the auxiliary agent according to the corresponding weight percentage, uniformly stirring again, extruding the uniformly mixed raw materials by using double screws, simultaneously adding the chopped glass fibers through a feeding port at the side of the fifth area of the double screws, and melting and extruding the materials together.

Specifically, the melt extrusion temperature is 180-.

Compared with the prior art, the invention has the beneficial effects that:

1) the amorphous compatilizer can reduce warpage caused by crystallization of the PBT on one hand because of no crystallization, and on the other hand, the compatilizer is provided with an epoxy polar group and can react and be compatible with terminal carboxyl of the PBT, and a small amount of fourth monomer can also increase compatibility with the PBT without adding the compatilizer.

2) The amorphous resin has epoxy polar groups, and can also be used as a coupling agent of glass fiber and PBT to toughen and reinforce the PBT composite material.

Detailed Description

The technical solutions of the present invention are further described in detail with reference to the following specific embodiments, which are only used for explaining the present invention and are not used for limiting the scope of the present invention.

The methods adopted by the invention are all conventional methods without special description, and the raw materials used by the invention are all commercial products without special description. Specifically, the PBT resin is a starter 1072 produced by Nantong star company by PTA method; the compatilizer is RAS-302 produced by Jiaxing Wen; the chopped glass fiber is Taishan company T436H; the toughening agent is energetic E515, the auxiliary agent comprises hyperbranched resin which is Waishaichen CYD-C600 and silicone master batch which is Dow Corning MB 50-002.

The invention provides a preparation method of a low-warpage reinforced PBT material, which comprises the following steps: firstly, drying the PBT resin for 4 hours at 120 ℃, then taking the dried PBT resin and the compatilizer according to the corresponding weight percentage, stirring and mixing uniformly, then adding the auxiliary agent according to the corresponding weight percentage, stirring and mixing uniformly again, then putting the uniformly mixed raw materials into an extrusion device for extrusion, simultaneously adding the chopped glass fibers through a side feeding port, and melting and extruding together to obtain the PBT resin. The temperature is 180 plus 260 ℃, and the screw rotating speed is 330 plus 360 revolutions per minute. The details are shown in the following table:

performance testing

The reinforced PBT materials prepared in examples 1 to 4 and comparative examples 1 and 3 were tested for notched Izod impact strength, tensile strength and shrinkage using the corresponding national standards, and the appearance was visually observed from a circular plate, with the results shown in the following table:

as can be seen from the examples and the comparative examples, the low-warpage reinforced PBT material provided by the invention has high tensile strength and impact strength, and in addition, the warpage is obviously reduced because the difference between the addition flow of the amorphous resin and the vertical direction shrinkage is 0.12-0.19% which is less than that of the comparative example 0.27-0.30%. In addition, the amorphous resin toughening material.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The low-warpage reinforced PBT material is characterized by comprising the following raw materials in percentage by weight: 50-71% of PBT resin, 0-10% of a compatilizer, 0-3% of a toughening agent, 28-35% of reinforcing fiber and 1-2% of an auxiliary agent.

2. The low warpage reinforced PBT material of claim 1, wherein the PBT resin is a blend of any one or both of viscosities 0.7-1.0.

3. The low warpage reinforced PBT material of claim 1, wherein the compatibilizer is a styrene, acrylonitrile, glycidyl methacrylate ternary random copolymer or a random copolymer of a small amount of a fourth monomer.

4. The PBT material of claim 1, wherein the toughening agent is POE-g-GMA or EMA-g-GMA or a mixture thereof.

5. The PBT material with low warpage and reinforcement according to claim 1, wherein the reinforcement fiber is any one or a mixture of any more of glass fiber, four-high-end fiber basalt, aramid, ultra-high molecular weight polyethylene and carbon fiber, preferably chopped glass fiber, with a length of 3-4.5mm and a diameter of 9-17 μm, and is a suitable polyester resin treated with a specific wetting agent (containing aminosilane or epoxy silane coupling agent).

6. The low-warpage reinforced PBT material as claimed in claim 1, wherein the auxiliary agent is any one or a mixture of any more of hyperbranched resin, PE wax, pentaerythritol stearate, silicone, antioxidant and nucleating agent.

7. A process for the preparation of a low warpage reinforced PBT material according to any one of claims 1 to 5, comprising the steps of: firstly, drying the PBT resin at the temperature of 115-125 ℃ for more than 4h, then taking the dried PBT resin and the compatilizer according to the corresponding weight percentage, stirring and mixing uniformly, then adding the auxiliary agent according to the corresponding weight percentage, stirring and mixing uniformly again, then putting the uniformly mixed raw materials into an extrusion device for extrusion, simultaneously adding the chopped glass fibers through a side feeding port, and melting and extruding together to obtain the PBT resin.

8. The preparation method of the low-warpage reinforced PBT material as claimed in claim 6, wherein the extrusion device is a twin-screw extruder, and the temperature of melt extrusion in the twin-screw extruder is 180-.