WO2022110674A1 - Glass fiber reinforced pbt/pc alloy with high strength, low warpage and high thermal deformation temperature, preparation method therefor and use thereof - Google Patents

Abstract

Provided is a glass fiber reinforced PBT/PC alloy with a high strength, a low warpage and a high thermal deformation temperature, a preparation method therefor and the use thereof. The PBT/PC alloy comprises the following components in parts by weight: 37.3%-64.6% of a PBT resin; 0-37.3% of a PC resin, 25%-40% of glass fibers, 0.2%-1.5% of a transesterification inhibitor and 0.2%-0.5% of an antioxidant; the PBT resin is a PBT resin with a terminal carboxyl group content of less than 10 mmol/kg, and the terminal carboxyl group content is tested based on GB/T 14190-2017; and the PC resin is a PC resin with a terminal hydroxyl content of less than 10 ppm. By selecting the content of a terminal carboxyl group in PBT and the content of terminal hydroxyl group in PC, the alloy has a better tensile strength, thermal deformation temperature and warping degree, and can be applied to household electrical appliances requiring high thermal deformation temperature and low warpage.

Description

A glass fiber reinforced PBT/PC alloy with high strength, low warpage and high heat distortion temperature and its preparation method and application technical field

The invention relates to the technical field of polymer materials, and more particularly to a glass fiber reinforced PBT/PC alloy with high strength, low warpage and high thermal deformation temperature, and a preparation method and application thereof.

Background technique

PBT resin is a crystalline thermoplastic with fast crystallization speed, chemical resistance and good heat resistance, but it also has disadvantages such as large molding shrinkage and low notched impact strength. As an amorphous engineering plastic, PC has excellent comprehensive properties, especially high impact strength and good dimensional stability, but PC has poor fluidity, poor solvent resistance, easy wear and high price. Blending PBT and PC can complement each other's strengths to obtain alloy materials with excellent comprehensive properties. In the home appliance and fan industry, in order to solve the problem of warpage of glass fiber reinforced PBT, PC is often added to PBT. However, when PBT and PC are blended, due to the residual titanate catalyst, the transesterification reaction will occur during the extrusion process, which reduces the crystallization temperature of the alloy, prolongs the molding time, reduces the heat distortion temperature, and reduces the heat resistance. At present, the transesterification reaction of the two is mainly inhibited by adding transesterification inhibitors.

In the prior art, as disclosed in CN106336640A, polycarbodiimide, anhydrous sodium dihydrogen phosphate (AMSP), triphenyl phosphate (TPP), etc. are used as transesterification inhibitors to quench residual catalysts in PBT to inhibit transesterification. The reaction makes PC/PBT better heat resistance. However, the improvement of performance is still limited only by means of ester inhibitors, and further improvement is necessary.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a glass fiber reinforced PBT/PC alloy with high strength, low warpage and high heat distortion temperature.

Another object of the present invention is to provide a preparation method of the PBT/PC alloy.

Another object of the present invention is to provide applications of the PBT/PC alloy.

The above-mentioned purpose of the present invention is achieved through the following technical solutions:

A glass fiber reinforced PBT/PC alloy with high strength and high heat distortion temperature, calculated in parts by weight, comprising the following components:

PBT resin 37.3～64.6%;

PC resin 10～37.3%;

Glass fiber 25～40%;

Transesterification inhibitor 0.2～1.5%;

Antioxidant 0.2～0.5%;

Described PBT resin is the PBT resin that terminal carboxyl group content is not higher than 10mmol/kg, and the test method of terminal carboxyl group content is according to GB/T 14190-2017;

Described PC resin is PC resin with terminal hydroxyl content not higher than 10ppm;

The transesterification inhibitor is polycarbodiimide.

The test method of terminal hydroxyl group content is as follows: use Bruker AVANCE III HD 600MHz nuclear magnetic resonance instrument to test the 31P nuclear magnetic resonance spectrum of PC resin. Cyclohexanol at a concentration of 4.0 mg/mL was used as the internal standard, chromium acetylacetonate at a concentration of 5 mg/mL was used as a relaxant, and 2-chloro-4,4,5,5-tetramethyl-1,3 , 2-dioxaphospholane as a phosphating reagent. 25 mg PC resin was dissolved in 400 μL deuterated pyridine/deuterated chloroform (volume ratio 1.6:1), 150 μL relaxation agent, 150 μL internal standard and 75 μL phosphating reagent were added as test samples. Test conditions: room temperature, 90° pulse angle, 25s pulse interval, 250s signal acquisition time, 61.9ppm scan width. The hydroxyl terminal content is calculated as follows:

where A (ppm) is the content of terminal hydroxyl groups of PC resin; c is the concentration of the internal standard; 150 (μL) is the volume of the internal standard; 100.16 (mmg/mmol) is the molar mass of cyclohexanol; m (mg) is the mass of the PC resin; B ₁ is the terminal hydroxyl peak area of the PC resin, and B ₂ is the hydroxyl peak area of cyclohexanol.

The inventor unexpectedly found that controlling the content of terminal carboxyl groups of PBT resin and the content of terminal hydroxyl groups of PC resin within the above ranges can further improve the tensile strength, heat distortion temperature and warpage of PBT/PC alloys. In the production process of PBT/PC alloy, the transesterification reaction will occur, which will reduce the mechanical properties and thermal deformation temperature of the material, and the terminal carboxyl group of PBT and the terminal hydroxyl group of PC will aggravate the transesterification reaction. PC with low-end hydroxyl content and polycarbodiimide, a transesterification inhibitor, can inhibit the transesterification reaction, thereby improving the performance of the material.

More preferably, the PBT resin is a PBT resin with a terminal carboxyl group content of 1-10 mmol/Kg.

More preferably, the PC resin is a PC resin with a terminal hydroxyl group content of 1-10 ppm.

The PBT and PC of the present invention can be purchased in the market.

Preferably, the glass fibers are glass fibers with an average diameter of 7-17 μm and an average length of 3-5 mm.

The types of glass fibers described in the present invention are not limited, and are preferably alkali-free glass fibers.

The antioxidant of the present invention can be selected from commonly used antioxidants. Preferably, the antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants.

The preparation method of the PBT/PC alloy comprises the following steps:

S1. PBT resin and PC resin are dried;

S2. Mix the dried PBT resin and PC resin of S1. with polycarbodiimide and antioxidant, and feed the materials from the main feeding port of the twin-screw extruder. The glass fiber is fed from the side of the twin-screw extruder. feeding port feeding;

S3. Set the temperature of each zone of the twin-screw extruder to 220-250°C, and extrude;

S4. Perform post-processing after extrusion to obtain the PBT/PC alloy.

Preferably, in S1., the drying conditions are drying at 120-140° C. for 4-6 hours.

Preferably, in S3., the rotational speed of the twin-screw extruder is 300-400 rpm.

Preferably, in S4., the post-processing includes cooling, air drying, dicing, packaging and other steps.

The application of the PBT/PC alloy in the preparation of products with high strength, high heat distortion temperature and low warpage properties. More specifically, the product is a home appliance product.

Compared with the prior art, the present invention has the following beneficial effects:

The PBT/PC alloy of the present invention has better tensile strength, heat distortion temperature, and warpage through the selection of the content of terminal carboxyl groups in PBT and the content of terminal hydroxyl groups in PC, and the tensile strength of the alloy is improved. >130MPa, heat distortion temperature >120℃, warpage <3mm, it can be applied to household appliances requiring high heat distortion temperature and low warpage.

Detailed ways

The present invention will be further described in detail below in conjunction with specific examples and comparative examples, but the present invention is not limited to the following examples.

In the examples, the raw materials without special instructions are all conventional commercial products.

PBT resin 1: Yizheng GX121J is selected, and the content of terminal carboxyl groups is 8mmol/kg;

PBT resin 2: Yizheng GX122J is selected, and the content of terminal carboxyl groups is 4mmol/kg;

PBT resin 3: choose Yizheng GX110, the content of terminal carboxyl group is 24mmol/kg;

PC resin 1: South Korea's Samyang 3030PJ is selected, and the content of terminal hydroxyl groups is 3ppm;

PC resin 2: LG, 1300 03 NP are selected, and the content of terminal hydroxyl groups is 8ppm;

PC resin 3: Idemitsu FN2200 is selected from Japan, and the content of terminal hydroxyl groups is 150ppm;

Glass fiber, choose ECS13-3.0-T436W (alkali-free glass fiber, glass fiber average diameter 13μm, average length 3.0mm, Taishan Glass Fiber Co., Ltd.)

Transesterification inhibitor: use Stabilizer 9000 polycarbodiimide (Kunshan Dingfa Chemical);

Antioxidant: RIANOX 1010 and RIANOX 168 (Rianlong) were selected respectively.

testing method:

In PBT resin, the test method of terminal carboxyl group content is according to GB/T 14190-2017;

In the PC resin, the test method for the content of terminal hydroxyl groups is as follows: The 31P nuclear magnetic resonance spectrum of the PC resin is tested with a Bruker AVANCE III HD 600MHz nuclear magnetic resonance instrument. Cyclohexanol at a concentration of 4.0 mg/mL was used as the internal standard, chromium acetylacetonate at a concentration of 5 mg/mL was used as a relaxant, and 2-chloro-4,4,5,5-tetramethyl-1,3 , 2-dioxaphospholane as a phosphating reagent. 25 mg PC resin was dissolved in 400 μL deuterated pyridine/deuterated chloroform (volume ratio 1.6:1), 150 μL relaxation agent, 150 μL internal standard and 75 μL phosphating reagent were added as test samples. Test conditions: room temperature, 90° pulse angle, 25s pulse interval, 250s signal acquisition time, 61.9ppm scan width. The hydroxyl terminal content is calculated as follows:

where A (ppm) is the content of terminal hydroxyl groups of PC resin; c is the concentration of the internal standard; 150 (μL) is the volume of the internal standard; 100.16 (mmg/mmol) is the molar mass of cyclohexanol; m (mg) is the mass of the PC resin; B ₁ is the terminal hydroxyl peak area of the PC resin, and B ₂ is the hydroxyl peak area of cyclohexanol.

The PBT/PC alloy samples to be tested were dried in a dehumidifying drying oven at 120 °C for 4 h, and then related performance tests were carried out.

Tensile strength test: According to the standard ISO 527-2:2016 injection molding tensile splines, test the tensile strength S, the unit is MPa;

Heat deformation temperature test: According to the standard ISO 75-2:2013 injection molding heat deformation spline, measure the heat deformation temperature T of 1.80Mpa, the unit is °C;

Warpage test: inject the PBT/PC alloy into a 100*100*1.5mm square plate, press one corner with a 1kg weight, and measure the height h from the diagonal to the horizontal plane with a vernier caliper, in mm. Examples 1-18 and Comparative Examples 1-6

According to the formulas in Tables 1 to 3, Examples 1 to 18 and Comparative Examples 1 to 6 were prepared, and the specific preparation steps were as follows:

S1. PBT resin and PC resin are dried at 120～140℃ for 4～6h;

S2. Mix the dried PBT resin and PC resin of S1. with polycarbodiimide and antioxidant, and feed the materials from the main feeding port of the twin-screw extruder. The glass fiber is fed from the side of the twin-screw extruder. feeding port feeding;

S3. Set the temperature of each zone of the twin-screw extruder to be 220-250° C. to perform extrusion, and the rotational speed of the twin-screw extruder is 300-400 rpm. ;

S4. Perform post-processing after extrusion to obtain the PBT/PC alloy.

The performance test of the embodiment and the comparative example is shown in Table 4.

Table 1

Table 2

table 3

	Comparative Example 1	Comparative Example 2	Comparative Example 3	Comparative Example 4
PBT resin 1	49.4	/	29.3	64.3
PBT resin 3	/	49.4	/	/
PC resin 1	/	20	40	5
PC resin 3	20	/	/	/
Fiberglass 1	30	30	30	30
Polycarbodiimide	0.5	0.5	0.5	0.5
Antioxidant 1010	0.2	0.2	0.2	0.2

Table 4

	Tensile strength S/MPa	Thermal deformation temperature T/℃	Warpage h/mm
Example 1	142	150	2.34
Example 2	144	132	1.24
Example 3	140	128	0.64
Example 4	143	125	0.26
Example 5	130	125	1.02
Example 6	144	132	1.24
Example 7	145	143	1.86
Example 8	148	150	2.44
Example 9	134	122	1.26
Example 10	144	132	1.24
Example 11	144	140	1.24
Example 12	142	143	1.26
Example 13	143	131	1.24
Example 14	143	133	1.26
Example 15	141	130	1.28
Comparative Example 1	122	117	1.26
Comparative Example 2	120	115	1.22
Comparative Example 3	124	110	0.18

Comparative Example 4

142

178

3.46

From the comparison of Example 2 with Comparative Example 1 and Comparative Example 2, it can be seen that when either the terminal carboxyl group content of PBT or the phenolic hydroxyl group content of PC exceeds the stated range, the tensile strength and heat distortion temperature of the product are significantly decreased.

It can be seen from Comparative Example 3 that when the amount of PC added is too high, although the warpage performance becomes better, the tensile strength and thermal deformation temperature drop rapidly. It can be seen from Comparative Example 4 that when the amount of PBT added is too high, the warpage performance of the composition decreases rapidly.

Claims (10)

1. A glass fiber reinforced PBT/PC alloy with high strength and high heat distortion temperature, characterized in that, calculated in parts by weight, it comprises the following components:

   PBT resin 37.3～64.6%;

   PC resin 10～37.3%;

   Glass fiber 25～40%;

   Transesterification inhibitor 0.2～1.5%;

   Antioxidant 0.2～0.5%;

   Described PBT resin is the PBT resin that terminal carboxyl group content is not higher than 10mmol/kg, and the test method of terminal carboxyl group content is according to GB/T 14190-2017;

   Described PC resin is PC resin with terminal hydroxyl content not higher than 10ppm;

   The transesterification inhibitor is polycarbodiimide.
2. The PBT/PC alloy according to claim 1, wherein the PBT resin has a terminal carboxyl group content of 1-10 mmol/kg.
3. The PBT/PC alloy according to claim 1, wherein the PC resin has a terminal hydroxyl group content of 1-10 ppm.
4. The PBT/PC alloy according to claim 1, wherein the glass fibers are glass fibers with an average diameter of 7-17 μm and an average length of 3-5 mm.
5. The PBT/PC alloy according to claim 1 or 4, wherein the glass fiber is an alkali-free glass fiber.
6. The PBT/PC alloy according to claim 1, wherein the antioxidant is one or more of hindered phenol antioxidants, phosphite antioxidants, and thioester antioxidants .
7. The preparation method of the PBT/PC alloy according to any one of claims 1 to 6, characterized in that it comprises the following steps:

   S1. PBT resin and PC resin are dried;

   S2. Mix the dried PBT resin and PC resin of S1. with polycarbodiimide and antioxidant, and feed the materials from the main feeding port of the twin-screw extruder. The glass fiber is fed from the side of the twin-screw extruder. feeding port feeding;

   S3. Set the temperature of each zone of the twin-screw extruder to 220-250°C, and extrude;

   S4. Perform post-processing after extrusion to obtain the PBT/PC alloy.
8. preparation method according to claim 7, is characterized in that, in S3., the rotating speed of twin-screw extruder is 300-400rpm.
9. Application of the PBT/PC alloy described in any one of claims 1 to 6 in preparing a product with high strength, high heat distortion temperature and low warpage performance.
10. The application according to claim 9, wherein the product is a home appliance product.