further, the low dielectric nano injection molded thermoplastic polyester composite material further comprises boron nitride, and specifically comprises the following components in percentage by weight:

thermoplastic polyester 58.4%

Polysilsesquioxane 5%

0.1 percent of antioxidant

0.5 percent of release agent

3 percent of toughening agent

3% of polyolefin

Glass fiber 10%

And 20% of boron nitride.

The thermoplastic polyester is a mixture of polybutylene terephthalate (PBT) and other non-PBT thermoplastic polyesters, and the weight ratio of the PBT to the thermoplastic polyester is 5: 1 to 1: 1. the other non-PBT thermoplastic polyester is at least one of PET, PETG and PCTG.

The polysilsesquioxane is polyhedral oligomeric silsesquioxane with a cage-shaped structure, such as at least one of cage-shaped methyl polysilsesquioxane, cage-shaped methyl propenyl polysilsesquioxane and cage-shaped aniline propyl polysilsesquioxane; preferred are polysilsesquioxanes having a cage structure and containing amino groups, such as caged anilinopropyl polysilsesquioxane.

The antioxidant is at least one of hindered phenol, hindered amine and phosphite ester.

The release agent is at least one of pentaerythritol ester and oxidized polyethylene wax.

The toughening agent is a toughening agent containing a glycidyl ether structure or/and a maleic anhydride structure, wherein the proportion of the glycidyl ether in the toughening agent is more than 5%, and the toughening agent is preferably AX 8900.

The polyolefin is at least one of polyethylene, polypropylene and polycyclic olefin.

The glass fiber is low-dielectric glass fiber, and the dielectric constant of the glass fiber is less than 4.6.

A preparation method of the low-dielectric nano injection molding thermoplastic polyester composite material comprises the following steps: the components are uniformly mixed according to the proportion, and then are extruded and granulated by an extruder, wherein the granulation temperature is 240-270 ℃.

The low-dielectric nano injection-molded thermoplastic polyester composite material is applied to the manufacture of mobile phones.

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

the invention adopts the combined action of thermoplastic polyester, polysilsesquioxane, antioxidant, release agent, toughening agent, polyolefin and glass fiber, has very high aluminum alloy bonding force under the nano injection molding process, and simultaneously can have low dielectric constant and low dielectric loss. The preparation method is simple and feasible, and is suitable for large-scale production and application.

Drawings

FIG. 1 is a schematic structural diagram of a metal plastic test monolith in an embodiment, 1-metal sheet, 4-plastic part.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

PBT is blue star chemical PBT1084, PET is characterization chemical SB500, PP is Duyao petrochemical K9928, low dielectric glass fiber is CPIC ECS303N-3-K (HL), and cage-shaped methyl polysilsesquioxane is Guangzhou new technology

POSS104, a caged methyl propenyl polysilsesquioxane, is a new technology of Guangzhou

POSS102, caged aniline propenyl polysilsesquioxane is a new technology of Guangzhou

POSS1012，Boron nitride is BN20, a company of science and technology limited, honor, beijing.

The stainless steel adhesion test standard used in the present invention refers to the standard in the japanese patent of Dacheng chemistry (e.g., WO2007/040245), specifically as follows:

as shown in figure 1, the stainless steel plastic cement test integrated piece has a bonding surface area of 0.5 square centimeter.

In all comparative experiments, the same injection molding conditions were maintained, barrel temperatures of 260 ℃ to 280 ℃ and mold temperatures of 140 ℃. The cohesion test is a biaxial tension test.

The dielectric constant and dielectric loss test standard is IEC 60250.

Example 1

According to the weight percentage, all the components are granulated by a double-screw extruder according to the proportion in the table 1, and the granulation temperature is 240-260 ℃. The obtained particles are subjected to injection molding to test the binding force and dielectric property of 6061 aluminum alloy.

TABLE 1 polysilsesquioxane Performance comparison

The data in table 1 show that after the system is added with PP, the subsequent increase of the amount of PP gradually reduces the bonding force of the aluminum alloy, especially when the content of PP reaches 10%, the bonding force is greatly reduced, and the yield can be ensured only when the bonding force reaches more than 30MPa, which is required by the mobile phone NMT industry. When the common dimethyl siloxane is added, the performance of the material is not improved but further reduced compared with PP. When the silsesquioxane is added, the dielectric constant and the dielectric loss of the material are equivalent to or lower than PP, but the bonding force of the aluminum alloy can be well maintained, particularly, the aniline propyl polysiloxane has no influence on the bonding force of the aluminum alloy basically and is even improved. It is inferred from the data that complete replacement of PP with silsesquioxane should give better performance, but the present invention subsequently employs a combination of PP and silsesquioxane due to the high price of silsesquioxane.

Example 2

According to the weight percentage, all the components are granulated by a double-screw extruder according to the proportion in the table 2, and the granulation temperature is 240-260 ℃. The obtained particles are subjected to injection molding to test the binding force and dielectric property of 6061 aluminum alloy.

TABLE 2 comparison of boron nitride Properties

The 5G mobile phone industry generally requires that the dielectric constant of the material is less than 3 and the dielectric loss is less than or equal to 0.005. To further reduce the dielectric constant of the material, the glass fiber content may be reduced. However, as can be seen from the data in table 2, after the glass fiber is reduced to 10%, the bonding force of the material is also reduced to below 30MPa, and the dielectric loss is not changed significantly. When the glass fiber is replaced by partial boron nitride, the dielectric constant and the dielectric loss of the material are both reduced, and meanwhile, the metal bonding force is not greatly reduced and still kept above 30 MPa.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. A low dielectric nano injection molding thermoplastic polyester composite material is characterized by comprising the following components in percentage by weight:

15-90% of thermoplastic polyester

1-10% of polysilsesquioxane

0.05 to 0.5 percent of antioxidant

0.1-2% of release agent

1 to 10 percent of toughening agent

0 to 15 percent of polyolefin

5-50% of glass fiber.

2. The low dielectric nano-injection molded thermoplastic polyester composite of claim 1, comprising in weight percent:

25-80% of thermoplastic polyester

5-10% of polysilsesquioxane

0.05 to 0.5 percent of antioxidant

0.1-2% of release agent

1 to 5 percent of toughening agent

5-10% of polyolefin

5-50% of glass fiber.

3. The low dielectric nano-injection molded thermoplastic polyester composite of claim 1, further comprising boron nitride, in weight percent, specifically comprising:

4. the low dielectric nano-injection molded thermoplastic polyester composite of claim 1, further comprising boron nitride, in weight percent, specifically comprising:

5. the low dielectric nano-injection molded thermoplastic polyester composite of any of claims 1-4, wherein:

the thermoplastic polyester is a mixture of polybutylene terephthalate and other thermoplastic polyesters which are not polybutylene terephthalate, and the weight ratio of the thermoplastic polyester is 5: 1 to 1: 1;

the polysilsesquioxane is cage-structured polysilsesquioxane.

6. The low dielectric nano-injection molded thermoplastic polyester composite of claim 5, wherein:

the other thermoplastic polyester is at least one of PET, PETG and PCTG;

the polysilsesquioxane is at least one of cage-shaped methyl polysilsesquioxane, cage-shaped methyl propenyl polysilsesquioxane and cage-shaped aniline propyl polysilsesquioxane.

7. The low dielectric nano-injection molded thermoplastic polyester composite of claim 5, wherein:

the polysilsesquioxane is cage-shaped aniline propyl polysilsesquioxane.

8. The low dielectric nano-injection molded thermoplastic polyester composite of any of claims 1-4, wherein:

the antioxidant is at least one of hindered phenol, hindered amine and phosphite ester;

the release agent is at least one of pentaerythritol ester and oxidized polyethylene wax;

the toughening agent is a toughening agent containing a glycidyl ether structure or/and a maleic anhydride structure, and the proportion of the glycidyl ether in the toughening agent is more than 5 percent;

the polyolefin is at least one of polyethylene, polypropylene and polycyclic olefin;

9. A method of preparing a low dielectric nano injection molded thermoplastic polyester composite as in any of claims 1-8, comprising the steps of: the components are uniformly mixed according to the proportion, and then are extruded and granulated by an extruder, wherein the granulation temperature is 240-270 ℃.

10. Use of the low dielectric nano injection molded thermoplastic polyester composite of any of claims 1-8 in the manufacture of a cell phone.