Glass fiber reinforced polybutylene terephthalate and preparation method thereof

Abstract

The invention relates to the technical field of resin application, in particular to glass fiber reinforced polybutylene terephthalate and a preparation method thereof, and the glass fiber reinforced polybutylene terephthalate comprises the following components in parts by weight: 60-70 parts of polybutylene terephthalate, 25-35 parts of glass fiber and 3-10 parts of an inorganic rheological agent; coating the epoxy impregnating compound on the glass fiber; mixing the polybutylene terephthalate particles with glass fibers, then adding an inorganic rheological agent, carrying out mixing extrusion by a twin-screw extruder, and carrying out traction, cooling, drying, pelletizing and other processes to prepare glass fiber reinforced polybutylene terephthalate particles; and carrying out injection molding on the glass fiber reinforced polybutylene terephthalate particles to prepare a sample strip. The glass fiber treated by the impregnating compound has certain stiffness and bundling property, and the interfacial compatibility of the glass fiber and matrix resin can be effectively improved, so that the mechanical property of the composite material is improved, and the impregnating compound has the characteristics of high tensile strength and large binding power.

Description

Technical Field

[0001] The invention relates to the technical field of resin application, in particular to glass fiber reinforced polybutylene terephthalate and a preparation method thereof. Background Art

[0002] Polybutylene terephthalate (PBT) is a typical crystalline thermoplastic engineering plastic with excellent weather resistance, fatigue resistance, self-lubrication, electrical insulation and low hygroscopicity. However, the mechanical properties and heat resistance of pure PBT resin itself are relatively low, and the fast crystallization rate leads to poor molding stability, which limits its wide application. In order to solve the above problems, glass fiber (GF) is usually used to reinforce PBT. The mechanical properties and heat resistance of the prepared composite materials are significantly improved, and the dimensional stability of the products is greatly improved. This type of product is suitable for extrusion injection molding process, and the products have high mechanical properties and are widely used in the automotive industry, electronic appliances and other fields. In the prior art, for GF reinforced resin composite materials, the interface bonding between GF and resin directly affects the mechanical properties of the composite materials. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a glass fiber reinforced polybutylene terephthalate and a preparation method thereof to solve the above problems.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a glass fiber reinforced polybutylene terephthalate, comprising the following components in parts by weight:

[0005] Polybutylene terephthalate 60-70 parts

[0006] Glass fiber 25-35 parts

[0007] 3-10 parts of inorganic rheological agent.

[0008] As a further embodiment of the present invention, the viscosity coefficient of the polybutylene terephthalate is 0.6-1.3.

[0009] As a further solution of the present invention, the glass fiber is a short fiber with a diameter ranging from 9 to 13 μm.

[0010] As a further solution of the present invention, the inorganic rheological agent is a spherical inorganic powder, and the particle size of the spherical inorganic powder is in the range of 0.5-5 μm.

[0011] As a further solution of the present invention, the spherical inorganic powder comprises the following components in parts by weight: 85-90 parts of silicon dioxide and 10-15 parts of aluminum oxide.

[0012] As a further embodiment of the present invention, the particle size of the spherical inorganic powder is 1.5 μm.

[0013] A preparation method of glass fiber reinforced polybutylene terephthalate, the specific steps are as follows:

[0014] Step 1, applying epoxy sizing agent on glass fiber;

[0015] Step 2, after mixing polybutylene terephthalate pellets with glass fibers, adding an inorganic rheological agent, mixing and extruding the mixture through a twin-screw extruder, and obtaining glass fiber reinforced polybutylene terephthalate pellets through processes such as traction, cooling, drying, and pelletizing;

[0016] Step three, making the glass fiber reinforced polybutylene terephthalate pellets into strips by injection molding.

[0017] As a further solution of the present invention, the epoxy impregnation in step 1 is an amine-modified water-based epoxy emulsion.

[0018] As a further solution of the present invention, the extrusion temperature in step 2 is 240-250° C., and the frequency of the twin-screw extruder is 15.5-17 Hz.

[0019] As a further solution of the present invention, in step three, the injection temperature is 235-255°C, the injection pressure is 800-900 MPa, and the molding mold temperature in step three is 85-100°C.

[0020] Since the present invention adopts the above technical scheme, the present invention has the advantages and positive effects that the glass fiber treated with the impregnating agent not only has a certain stiffness and bundling property, but also can effectively improve the interface compatibility between the glass fiber and the matrix resin, thereby improving the mechanical properties of the composite material, and has the characteristics of high tensile strength and strong bonding force. DETAILED DESCRIPTION

[0021] raw material:

[0022] GF chopped strands: ECS13-03-534A, Jushi Group Co., Ltd.

[0023] PBT pellets: GX112, Sinopec Yizheng Chemical Fiber Co., Ltd.;

[0024] Inorganic rheological agent: WN-1212, Yangzhou Weiner Technology Co., Ltd.

[0025] Main equipment and instruments

[0026] Twin screw extruder: L / D=40, Coperion (Nanjing)

[0027] Injection molding machine: S-2000i100A, FANUC, Japan;

[0028] Universal material testing machine: Z050, Zwick, Germany;

[0029] Impact testing machine: Model 6956.000, CEAST, Italy;

[0030] Melt flow rate (MFR) instrument: RL-Z18, Shanghai Star Scientific Instrument Co., Ltd.

[0031] Example 1

[0032] The glass fiber reinforced polybutylene terephthalate of the present invention comprises the following components by weight: 60 parts of polybutylene terephthalate

[0033] Glass fiber 25 parts

[0034] 3 parts of inorganic rheological agent;

[0035] The viscosity coefficient of polybutylene terephthalate is 0.6; the diameter of the glass fiber is a short fiber of 9 μm; the inorganic rheological agent is a spherical inorganic powder, and the particle size of the spherical inorganic powder is 0.5 μm; the spherical inorganic powder includes the following components by weight: 85 parts of silicon dioxide and 10 parts of aluminum oxide.

[0036] A preparation method of glass fiber reinforced polybutylene terephthalate, the specific steps are as follows:

[0037] Step 1, coating the amine-modified waterborne epoxy emulsion on the glass fiber;

[0038] Step 2: After mixing polybutylene terephthalate pellets with glass fibers, an inorganic rheological agent is added, and the mixture is extruded at 240° C. by a twin-screw extruder with a main engine frequency of 15.5 Hz, and glass fiber reinforced polybutylene terephthalate pellets are obtained through processes such as traction, cooling, drying, and pelletizing;

[0039] Step three, the glass fiber reinforced polybutylene terephthalate pellets are molded into strips at an injection molding temperature of 235° C., an injection molding pressure of 800 MPa, and a molding mold temperature of 85° C.

[0040] Example 2

[0041] The glass fiber reinforced polybutylene terephthalate of the present invention comprises the following components by weight: 63 parts of polybutylene terephthalate

[0042] Glass fiber 28 parts

[0043] 5 parts of inorganic rheological agent;

[0044] The viscosity coefficient of polybutylene terephthalate is 0.8; the diameter of the glass fiber is a short fiber of 10 μm; the inorganic rheological agent is a spherical inorganic powder, and the particle size of the spherical inorganic powder is 1.5 μm; the spherical inorganic powder includes the following components by weight: 86 parts of silicon dioxide and 12 parts of aluminum oxide.

[0045] A preparation method of glass fiber reinforced polybutylene terephthalate, the specific steps are as follows:

[0046] Step 1, coating the amine-modified waterborne epoxy emulsion on the glass fiber;

[0047] Step 2: After mixing polybutylene terephthalate pellets with glass fibers, an inorganic rheological agent is added, and the mixture is extruded at 244° C. by a twin-screw extruder with a main engine frequency of 16 Hz, and the glass fiber reinforced polybutylene terephthalate pellets are obtained through processes such as traction, cooling, drying, and pelletizing;

[0048] Step three, the glass fiber reinforced polybutylene terephthalate pellets are molded into strips by injection molding at a temperature of 245° C., an injection molding pressure of 830 MPa, and a molding mold temperature of 92° C.

[0049] Example 3

[0050] The glass fiber reinforced polybutylene terephthalate of the present invention comprises the following components by weight: 68 parts of polybutylene terephthalate

[0051] Glass fiber 32 parts

[0052] 7 parts of inorganic rheological agent;

[0053] The viscosity coefficient of polybutylene terephthalate is 1.0; the diameter of the glass fiber is a short fiber of 12 μm; the inorganic rheological agent is a spherical inorganic powder, and the particle size of the spherical inorganic powder is 3.5 μm; the spherical inorganic powder includes the following components in parts by weight: 88 parts of silicon dioxide and 14 parts of aluminum oxide.

[0054] A preparation method of glass fiber reinforced polybutylene terephthalate, the specific steps are as follows:

[0055] Step 1, coating the amine-modified waterborne epoxy emulsion on the glass fiber;

[0056] Step 2: After mixing polybutylene terephthalate pellets with glass fiber, an inorganic rheological agent is added, and the mixture is extruded by a 16.5 Hz twin-screw extruder at 248° C., and glass fiber reinforced polybutylene terephthalate pellets are obtained through processes such as traction, cooling, drying, and pelletizing;

[0057] Step three, the glass fiber reinforced polybutylene terephthalate pellets are molded into strips by injection molding at a temperature of 250° C., an injection molding pressure of 870 MPa, and a molding mold temperature of 95° C.

[0058] Example 4

[0059] The glass fiber reinforced polybutylene terephthalate of the present invention comprises the following components by weight: 70 parts of polybutylene terephthalate

[0060] Glass fiber 35 parts

[0061] 10 parts of inorganic rheological agent;

[0062] The viscosity coefficient of polybutylene terephthalate is 1.3; the diameter of the glass fiber is a short fiber of 13 μm; the inorganic rheological agent is a spherical inorganic powder, and the particle size of the spherical inorganic powder is 5 μm; the spherical inorganic powder includes the following components by weight: 90 parts of silicon dioxide and 15 parts of aluminum oxide.

[0063] A method for preparing glass fiber reinforced polybutylene terephthalate, wherein the specific steps are as follows:

[0064] Step 1, coating the amine-modified waterborne epoxy emulsion on the glass fiber;

[0065] Step 2: After mixing polybutylene terephthalate pellets with glass fibers, an inorganic rheological agent is added, and the mixture is extruded at 250° C. by a twin-screw extruder with a main engine frequency of 17 Hz, and glass fiber reinforced polybutylene terephthalate pellets are obtained through processes such as traction, cooling, drying, and pelletizing;

[0066] Step three, the glass fiber reinforced polybutylene terephthalate pellets are molded into strips at an injection molding temperature of 255° C., an injection molding pressure of 900 MPa, and a molding mold temperature of 100° C.

[0067] Table 1 is the performance test of Examples 1-4

[0068] Example 1 Example 2 Example 3 Example 4 Tensile strength / MPa 133 135 135 136 Elastic modulus / MPa 8925.3 9000.5 9031.2 9075.8 Tensile elongation at break / % 2.4 2.5 2.5 2.6 Bending strength / MPa 228 236 241 243 Flexural modulus / MPa 9890.6 9927.9 9934.2 9940.1 <![CDATA[Notched impact strength / kJ / m 2 > 14.1 14.2 14.2 14.2

[0069] It can be seen from Table 1 that the present invention has the characteristics of high tensile strength and large bonding force, and can improve the mechanical properties of the composite material.

[0070] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. A glass fiber reinforced polybutylene terephthalate, characterized in that: It comprises the following components in parts by weight: Polybutylene terephthalate 60-70 parts Glass fiber 25-35 parts 3-10 parts of inorganic rheological agent.

2. The glass fiber reinforced polybutylene terephthalate according to claim 1, characterized in that: The viscosity coefficient of the polybutylene terephthalate is 0.6-1.

3.

3. The glass fiber reinforced polybutylene terephthalate according to claim 1, characterized in that: The glass fibers are short fibers with a diameter ranging from 9 to 13 μm.

4. The glass fiber reinforced polybutylene terephthalate according to claim 1, characterized in that: The inorganic rheological agent is spherical inorganic powder, and the particle size of the spherical inorganic powder ranges from 0.5 to 5 μm.

5. The glass fiber reinforced polybutylene terephthalate according to claim 4, characterized in that: The spherical inorganic powder comprises the following components by weight: 85-90 parts of silicon dioxide and 10-15 parts of aluminum oxide.

6. The glass fiber reinforced polybutylene terephthalate according to claim 4, characterized in that: The particle size of the spherical inorganic powder is 1.5 μm.

7. A method for preparing glass fiber reinforced polybutylene terephthalate according to any one of claims 1 to 6, characterized in that: Specific steps as follows: Step 1, applying epoxy sizing agent on glass fiber; Step 2, after mixing polybutylene terephthalate pellets with glass fibers, adding an inorganic rheological agent, mixing and extruding the mixture through a twin-screw extruder, and obtaining glass fiber reinforced polybutylene terephthalate pellets through processes such as traction, cooling, drying, and pelletizing; Step three, making the glass fiber reinforced polybutylene terephthalate pellets into strips by injection molding.

8. The method for preparing glass fiber reinforced polybutylene terephthalate according to claim 7, characterized in that: The epoxy impregnation in the step 1 is an amine-modified water-based epoxy emulsion.

9. The method for preparing glass fiber reinforced polybutylene terephthalate according to claim 7, characterized in that: In the step 2, the extrusion temperature is 240-250° C., and the frequency of the twin-screw extruder is 15.5-17 Hz.

10. The method for preparing glass fiber reinforced polybutylene terephthalate according to claim 7, characterized in that: In the step three, the injection temperature is 235-255°C, the injection pressure is 800-900MPa, and the molding mold temperature in the step three is 85-100°C.