CN112592565A

CN112592565A - Low-warpage glass fiber reinforced PBT (polybutylene terephthalate) material and preparation method thereof

Info

Publication number: CN112592565A
Application number: CN202011301077.4A
Authority: CN
Inventors: 冯亦奇; 朱勇; 芦扣祥
Original assignee: Jiangsu Bolin Plastics Co ltd
Current assignee: Jiangsu Bolin Plastics Co ltd
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-04-02

Abstract

The application discloses a low-warpage glass fiber reinforced PBT material and a preparation method thereof, and relates to the field of polymer composite materials. The glass fiber reinforced PBT material comprises the following components in percentage by mass: 40-85% of polybutylene terephthalate; 5-30% of a thermoplastic polyester elastomer; 5-30% of glass fiber; 0.3-0.8% of composite antioxidant; 0.3-0.8% of a lubricant; wherein the thermoplastic polyester elastomer has a hardness of 40 to 72D. According to the application, the thermoplastic polyester elastomer material (TPEE) with the hardness of 40-72D is added into the glass fiber reinforced PBT material, so that the material has excellent toughness, and the warping degree of the material is improved to a certain extent. By adjusting the amount of TPEE added, the problems such as shrinkage uniformity of the material can be improved.

Description

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

Technical Field

The application relates to the field of polymer composite materials, in particular to a low-warpage glass fiber reinforced PBT material and a preparation method thereof.

Background

The structure of polybutylene terephthalate (PBT) is shown in the following, and as can be seen from the molecular formula, the PBT main chain is composed of saturated linear molecules, and the repeating unit of the PBT main chain is composed of rigid benzene rings and flexible fatty alcohol

Because the molecular chain contains benzene rings and ester groups, the PBT has higher rigidity and better flexibility, and has the properties of lower water absorption rate and acid and alkali resistance due to the structural characteristics. Meanwhile, due to the regular structural characteristics, the PBT can be rapidly crystallized at low temperature, and has excellent forming and processing properties, so that the PBT has good corrosion resistance and weather resistance, and can still maintain excellent electrical insulation and mechanical properties in harsh environments such as humidity. In addition, the molecules of the PBT material have no side chains and have a symmetrical structure, so that the molecules can be tightly stacked, and the PBT has high crystallinity and a high melting point. Thus, PBT has an excellent balance of properties.

However, although the PBT has excellent comprehensive performance, the product has the defects of easy warpage and notch sensitivity, thereby the application of the PBT is influenced to a certain extent. Specifically, the PBT is a crystalline engineering plastic, has a large molding shrinkage rate and a poor dimensional stability, and easily causes an overlarge warping degree of a product in an injection molding process, particularly a glass fiber reinforced PBT material, so that the application range of the PBT product is limited. Therefore, the reasonable injection molding process, the improvement of the shrinkage uniformity of the PBT, and the improvement of the performance and the dimensional stability of the PBT plastic product become difficult problems which need to be solved urgently.

Disclosure of Invention

The application aims to provide a low-warpage glass fiber reinforced PBT material, and the problems that in the prior art, a glass fiber reinforced PBT material is large in shrinkage rate difference, serious in product warpage and deformation and the like are solved.

In order to achieve the above purpose, the embodiments of the present application adopt the following technical solutions: the low-warpage glass fiber reinforced PBT material comprises the following components in percentage by mass: 40-85% of polybutylene terephthalate; 5-30% of a thermoplastic polyester elastomer; 5-30% of glass fiber; 0.3-0.8% of composite antioxidant; 0.3-0.8% of a lubricant; wherein the thermoplastic polyester elastomer has a hardness of 40 to 72D.

In the technical scheme, the thermoplastic polyester elastomer material (TPEE) with the hardness of 40-72D is added into the glass fiber reinforced PBT material, so that the material has excellent toughness, and the warping degree of the material is improved to a certain extent. By adjusting the amount of TPEE added, the problems such as shrinkage uniformity of the material can be improved.

Further, according to the embodiment of the present application, wherein the glass fiber is an E-glass fiber.

Further, according to the embodiment of the present application, the composite antioxidant is any two selected from pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], phenyl tris (2, 4-di-tert-butyl) phosphite, antioxidant S9228, and n-octadecyl β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

Further, according to the embodiment of the application, the mass ratio of the two antioxidants in the composite antioxidant is 1: 1.

Further, according to an embodiment of the present application, wherein the lubricant is at least one selected from stearic acid, calcium stearate, ethylene bis stearate, and pentaerythritol stearate.

In addition, in order to achieve the above purpose, the embodiment of the present application also discloses a preparation method of the low-warpage glass fiber reinforced PBT material, which includes the following steps:

taking materials, namely taking the raw materials according to the components and the proportion thereof;

mixing materials, namely uniformly mixing the raw materials to obtain a mixture;

adding materials, namely adding the mixed mixture into an extruder through a main feeding port of the extruder;

and (3) melting, blending and extruding, extruding material strips by an extruder, cooling by water, drying by blowing, and granulating to obtain the product.

Further, according to the examples of the present application, in the compounding step, the antioxidant and the lubricant are mixed to prepare the premix, and then the premix is uniformly mixed with the polybutylene terephthalate and the thermoplastic polyester elastomer in a high-speed mixer.

Further, according to the embodiment of the application, in the step of melt blending and extruding, the length-diameter ratio of an extruder screw of the extruder is 1:30-1: 50.

Further, according to the present application example, wherein, in the melt blending extrusion step, the extrusion temperature is 230-280 ℃.

Further, according to the embodiment of the application, in the step of melt blending and extrusion, the screw rotating speed of the extruder is 300-450 r/min.

Compared with the prior art, the method has the following beneficial effects: according to the application, the thermoplastic polyester elastomer material (TPEE) with the hardness of 40-72D is added into the glass fiber reinforced PBT material, so that the material has excellent toughness, and the warping degree of the material is improved to a certain extent. By adjusting the amount of TPEE added, the problems such as shrinkage uniformity of the material can be improved.

Detailed Description

In order to make the objects and technical solutions of the present invention clear and fully described, and the advantages thereof more apparent, embodiments of the present invention are described in further detail below. It is to be understood that the specific embodiments described herein are merely illustrative of some embodiments of the invention and are not limiting of the invention, and that all other embodiments obtained by those of ordinary skill in the art without the exercise of inventive faculty are within the scope of the invention.

In the description of the present invention, it should be noted that the terms "center", "middle", "upper", "lower", "left", "right", "inner", "outer", "top", "bottom", "side", "vertical", "horizontal", and the like indicate orientations or positional relationships only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "a," "an," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

For the purposes of simplicity and explanation, the principles of the embodiments are described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent, however, to one skilled in the art that the embodiments may be practiced without these specific details. In some instances, well-known methods and structures have not been described in detail so as not to unnecessarily obscure the embodiments. In addition, all embodiments may be used in combination with each other.

The application discloses a low-warpage glass fiber reinforced PBT material, and the warpage degree of the glass fiber reinforced PBT material is improved by reducing the shrinkage rate difference of the glass fiber reinforced PBT material. Based on the above, the low-warpage glass fiber reinforced PBT material comprises the following components: 40-85 wt% of polybutylene terephthalate (PBT), 5-30 wt% of thermoplastic polyester elastomer (TPEE), 5-30 wt% of Glass Fiber (GF), 0.3-0.8 wt% of composite antioxidant and 0.3-0.8 wt% of lubricant. Wherein the hardness of the TPEE is 40-72D.

In the technical scheme, the TPEE with the hardness of 40-72D is added into the glass fiber reinforced PBT material, so that the material has excellent toughness, and the warping degree of the material is improved to a certain extent.

Specifically, the PBT is a matrix of the composite material, and the PBT serves as a material of a continuous phase in the composite material, and has a binding effect in order to balance loads, disperse loads, and protect TPEE and GF.

The TPEE material has a toughening effect and can improve the shrinkage uniformity of the material. The hardness and addition amount of the TPEE material have an influence on the shrinkage uniformity of the composite material, and the addition amount of 5-30 wt% and the hardness of 40-72D are optimal.

The GF material is made of E-glass fiber, so that the strength of the composite material is enhanced, the composite material plays a role of a skeleton, and the GF material is used for supporting the structure of a composite material matrix and is used as a support of the whole composite material.

The composite antioxidant is used for delaying or inhibiting the oxidation process of the polyester resin, thereby preventing the aging of the polymer and prolonging the service life of the polymer. Further, the composite antioxidant can be any two of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] (antioxidant 1010), tris (2, 4-di-tert-butyl) phenyl phosphite (antioxidant 168), antioxidant S9228 and n-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant 1076), and the mass ratio of the two antioxidants is 1: 1.

The lubricant is used for reducing the friction between materials and between the materials and the surface of processing equipment, thereby reducing the flow resistance of the solution, reducing the viscosity of the solution, improving the fluidity of the solution, avoiding the adhesion of the solution and the processing equipment and improving the smoothness of the surface of a product. Specifically, the lubricant may be selected from at least one of stearic acid, calcium stearate, Ethylene Bis Stearate (EBS), and pentaerythritol stearate (PETS).

In addition, the application also discloses a preparation method of the low-warpage glass fiber reinforced PBT material, which comprises the following steps:

taking materials, and taking the raw materials according to the components and the proportion thereof.

Mixing materials, namely mixing the composite antioxidant and the lubricant to prepare a premix, and then placing the premix, the polybutylene terephthalate and the thermoplastic polyester elastomer into a high-speed mixer to be uniformly mixed.

And (4) feeding, namely feeding the mixed mixture into an extruder through a main feeding port of the extruder.

And (3) melting, blending and extruding, extruding material strips by an extruder, cooling by water, drying by blowing, and granulating to obtain the product. Wherein the length-diameter ratio of the extruder screw of the extruder is 1:30-1:50, the extrusion temperature is 230-280 ℃, and the screw rotating speed of the extruder is 300-450r/min

The technical solutions of the present application are further illustrated by the following examples 1 to 13, but the present application is not limited to these examples.

The source of the raw materials in the following examples is shown in table 1.

TABLE 1

[ example 1 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically 69 percent of PBT, 15 percent of TPEE 72D, 15 percent of GF, 0.5 percent of compound antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

Mixing materials, namely mixing the composite antioxidant and the lubricant to prepare a premix, and then placing the premix, PBT and TPEE into a high-speed mixer to be uniformly mixed.

Adding materials, namely adding the mixed mixture into an extruder through a main feeding port of the extruder; and (3) melting, blending and extruding, extruding material strips by an extruder, cooling by water, drying by blowing, and granulating to obtain the product.

[ example 2 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically 69 percent of PBT, 15 percent of TPEE 68D, 15 percent of GF, 0.5 percent of compound antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 3 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically 69 percent of PBT, 15 percent of TPEE 55D, 15 percent of GF, 0.5 percent of compound antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 4 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically taking the raw materials comprising 69 percent of PBT, 15 percent of TPEE 40D, 15 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 5 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 64 percent of PBT, 15 percent of TPEE 72D, 20 percent of GF, 0.5 percent of compound antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 6 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 59 percent of PBT, 15 percent of TPEE 72D, 25 percent of GF, 0.5 percent of compound antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 7 ]

Taking materials, namely taking the raw materials according to the components and the proportion, wherein the raw materials comprise 54% of PBT, 15% of TPEE 72D, 30% of GF, 0.5% of compound antioxidant and 0.5% of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 8 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 64 percent of PBT, 5 percent of TPEE 72D, 30 percent of GF, 0.5 percent of compound antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 9 ]

Taking materials, namely taking the raw materials according to the components and the proportion, wherein the raw materials comprise 49% of PBT, 20% of TPEE 72D, 30% of GF, 0.5% of composite antioxidant and 0.5% of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 10 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 44% of PBT, 25% of TPEE 72D, 30% of GF, 0.5% of compound antioxidant and 0.5% of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 11 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 39% of PBT, 30% of TPEE 72D, 30% of GF, 0.5% of composite antioxidant and 0.5% of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 12 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 39% of PBT, 30% of TPEE 72D, 30% of GF, 0.5% of composite antioxidant and 0.5% of lubricant. Wherein the composite antioxidant is a mixture of 1076 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

[ example 13 ]

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 39% of PBT, 30% of TPEE 72D, 30% of GF, 0.5% of composite antioxidant and 0.5% of lubricant. Wherein the composite antioxidant is a mixture of 1076 and 168 in a mass ratio of 1:1, and the lubricant is EBS.

Comparative examples 1 to 6 are listed below for comparison in examples 1 to 13.

Comparative example 1

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 84 percent of PBT, 15 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

Comparative example 2

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 79 percent of PBT, 20 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

Comparative example 3

Taking materials, namely taking the raw materials according to the components and the proportion thereof, wherein the raw materials comprise 74 percent of PBT, 25 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

Comparative example 4

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically 69 percent of PBT, 30 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1010 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

Comparative example 5

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically 69 percent of PBT, 30 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1076 and 168 in a mass ratio of 1:1, and the lubricant is PETS.

Comparative example 6

Taking materials, namely taking the raw materials according to the components and the proportion thereof, specifically 69 percent of PBT, 30 percent of GF, 0.5 percent of composite antioxidant and 0.5 percent of lubricant. Wherein the composite antioxidant is a mixture of 1076 and 168 in a mass ratio of 1:1, and the lubricant is EBS.

The raw material ratios in examples 1 to 13 and comparative examples 1 to 6 are shown in Table 2.

TABLE 2

The materials provided in examples 1 to 13 and comparative examples 1 to 6 were subjected to shrinkage property testing, the shrinkage rate was measured according to ASTM D995, and the test specimens were square sheets with a side length of 60mm and a thickness of 2 mm.

During testing, firstly, a vernier caliper with the precision of 0.02mm is used for measuring the size of a mold cavity, 5 samples are taken after the samples are placed for 48 hours after being molded, the longitudinal and transverse sizes are respectively measured by the vernier caliper, the average value is obtained, and the shrinkage rates in different directions are respectively calculated according to the following formula.

Wherein S is_w: longitudinal shrinkage (%); w_m: the mold longitudinal dimension (mm); w_s: average longitudinal dimension (mm) after the specimen is left standing;

wherein S is_l: transverse shrinkage (%); l is_m: the transverse dimension of the mold (mm); l is_s: average transverse dimension (mm) after the specimen is left standing.

The test results are summarized in Table 3 below.

TABLE 3

As can be seen from the above table, by adding 40-72D of TPEE material, the PBT/GF material has small anisotropy of shrinkage and low material warpage.

Although the illustrative embodiments of the present application have been described above to enable those skilled in the art to understand the present application, the present application is not limited to the scope of the embodiments, and various modifications within the spirit and scope of the present application defined and determined by the appended claims will be apparent to those skilled in the art from this disclosure.

Claims

1. The low-warpage glass fiber reinforced PBT material is characterized by comprising the following components in percentage by mass:

wherein the thermoplastic polyester elastomer has a hardness of 40-72D.

2. The low-warpage glass fiber reinforced PBT material of claim 1, wherein the glass fiber is E-glass fiber.

3. The low-warpage glass fiber reinforced PBT material as claimed in claim 1, wherein the composite antioxidant is any two selected from pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], phenyl tris (2, 4-di-tert-butyl) phosphite, antioxidant S9228, and n-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate.

4. The low-warpage glass fiber reinforced PBT material as claimed in claim 3, wherein the mass ratio of the two antioxidants in the composite antioxidant is 1: 1.

5. The low-warpage glass fiber reinforced PBT material of claim 1, wherein the lubricant is at least one selected from stearic acid, calcium stearate, ethylene bis stearate and pentaerythritol stearate.

6. A method for preparing the low-warpage glass fiber reinforced PBT material of claim 1, comprising the steps of:

7. The preparation method of the low-warpage glass fiber reinforced PBT material as claimed in claim 6, wherein in the mixing step, the composite antioxidant and the lubricant are mixed to prepare a premix, and then the premix, the polybutylene terephthalate and the thermoplastic polyester elastomer are placed in a high-speed mixer to be uniformly mixed.

8. The preparation method of the low-warpage glass fiber reinforced PBT material according to claim 6, wherein in the step of melt blending and extruding, the length-diameter ratio of an extruder screw of the extruder is 1:30-1: 50.

9. The method for preparing the low-warpage glass fiber reinforced PBT material as claimed in claim 6, wherein in the step of melt blending and extruding, the extrusion temperature is 230-280 ℃.

10. The preparation method of the low-warpage glass fiber reinforced PBT material according to claim 6, wherein in the step of melt blending and extruding, the screw rotation speed of the extruder is 300-450 r/min.