WO2023174284A1

WO2023174284A1 - Pbt composition, preparation method therefor and use thereof

Info

Publication number: WO2023174284A1
Application number: PCT/CN2023/081368
Authority: WO
Inventors: 姚华侠; 陈平绪; 叶南飚; 卢立波; 付学俊
Original assignee: 江苏金发科技新材料有限公司; 上海金发科技发展有限公司
Priority date: 2022-03-17
Filing date: 2023-03-14
Publication date: 2023-09-21
Also published as: CN114591607B; CN114591607A

Abstract

Disclosed in the present invention are a PBT composition, a preparation method therefor and the use thereof. The PBT composition of the present invention comprises the following components in parts by weight: 35-45 parts of PBT resin, 10-20 parts of PC resin, 25-40 parts of brominated PC, 5-15 parts of a toughening agent and 0.1-0.3 part of an ester exchange inhibitor, wherein the brominated PC is a random copolymer of triphosgene, tetrabromobisphenol A and bisphenol A, the intrinsic viscosity of the PBT resin is 0.8-1.2 dl/g, and the melt index of the PC resin ≤ 10 g/10min, the melt index being tested under the condition of 300 ℃/1.2kg according to the ASTM D1238 standard. The PBT composition of the present invention has a notched cantilever beam impact resistance (type A) of 500 J/m or above, a molding shrinkage rate of 1% or above and a maximum covered bolt torque value of 27 N·m or above, and therefore is suitable for manufacturing an embedded bolt insert.

Description

A PBT composition and its preparation method and application

Technical field

The invention belongs to the field of plastics and relates to a PBT composition and its preparation method and application.

Background technique

In fields such as industrial control and agricultural machinery, many components require pre-embedded screw posts during production, and it is expected that the screw posts and plastic parts can withstand high torque during assembly or use. This demand not only requires the material to have better rigidity, but also requires the material to have better toughness. Due to its good crystallization ability, PBT resin has a notched impact strength of only 50-100J/m. At present, the notched impact strength of PBT resin is mainly improved by adding tougheners, glass fibers or PC (polycarbonate) resin. However, adding only a toughening agent will significantly reduce the flexural modulus of PBT, resulting in a serious reduction in the torsion force of the coated screw column. Although adding only glass fiber can achieve the purpose of simultaneously improving rigidity and notched impact strength, the glass fiber reinforced PBT There will be problems of floating fibers and warping, and it cannot meet the size and appearance requirements of embedded screw column inserts; if only PC resin is added, it will undergo a transesterification reaction with PBT, causing the molding shrinkage of the material to decrease, eventually leading to The torque of the covered screw column is reduced.

Therefore, how to improve the notched impact strength of PBT while obtaining better appearance, higher molding shrinkage and torsion of coated screw columns has become an urgent technical problem to be solved.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a PBT composition and its preparation method and application, aiming to make the PBT material have high notch impact strength, molding shrinkage and coated screw column torque at the same time, and You can choose not to add fiberglass to avoid problems with floating fibers and warping in appearance.

In order to achieve the above object, the first aspect of the present invention provides a PBT composition, including the following components by weight: 35 to 45 parts by weight of PBT resin, 10 to 20 parts of PC resin, 25 to 40 parts of brominated PC, and toughened. 5 to 15 parts of agent, 0.1 to 0.3 parts of transesterification inhibitor, wherein the brominated PC is a random copolymer of triphosgene, tetrabromobisphenol A and bisphenol A, and the intrinsic viscosity of the PBT resin is 0.8 ~1.2dl/g, the PC tree The melt index of the grease is ≤10g/10min. The melt index is measured in accordance with ASTM D1238-2010 standard at 300℃/1.2kg.

The PBT composition improves its notched impact strength by adding a toughening agent and PC resin with a specific melt index; by adding a transesterification inhibitor to suppress the transesterification reaction between PC and PBT, it can effectively avoid molding shrinkage caused by the introduction of PC. The molding shrinkage rate and the torque of the coated screw column are reduced; at the same time, the molding shrinkage rate and the torque of the coated screw column are further increased by adding specific brominated PC. The Izod notch impact strength (type A) of the PBT composition is above 500J/m, the molding shrinkage is above 1%, and the maximum torque value of the coated screw column is above 25N·m. The PBT composition does not need to add glass fibers to avoid the problems of floating fibers and warping in appearance.

In this article, the "intrinsic viscosity of PBT resin" is measured according to the capillary viscometer method in the GB/T 14190-2008 standard. If the intrinsic viscosity of the PBT resin is too high or too low, the maximum torque value of the coated screw column of the PBT composition will be low. Therefore, the intrinsic viscosity of the PBT resin is selected to be in the range of 0.8 to 1.2 dl/g.

If the melt index of the PC resin is too high, the maximum torque value of the coated screw column of the PBT composition will be low. Therefore, the melt index of the PC resin is selected to be below 10g/10min.

Preferably, the structural formula of the brominated PC is as follows:

Among them, x:y=1:1.5～1:6.5, x+y≥10.

The brominated PC can be synthesized by a method including the following steps: In a 500mL four-necked flask, add bisphenol A, tetrabromobisphenol A, and an inorganic alkali solution sufficient to dissolve bisphenol A and tetrabromobisphenol A in proportion ( Such as sodium hydroxide, potassium hydroxide and other inorganic base solutions) and the catalyst tetrabutylammonium bromide accounting for 0.1 to 5% of the total amount), dropwise add organic triphosgene to the stirred mixed solution at 25 to 30°C. solution (such as 1,2-dichloroethane solution of triphosgene, etc.), continue to stir the reaction for 1 to 3 hours after the dripping is completed. After the reaction is completed, let the solution stand, separate the organic phase, and wash the organic phase repeatedly with deionized water. Then the organic phase is added dropwise into methanol, and the precipitated polymer is collected as the brominated PC, and its reaction formula is as follows:

When x and y of the brominated PC satisfy x:y=1:1.5~1:6.5, x+y≥10, higher coating can be obtained than brominated PC with x and y outside this range. Maximum torque value of screw column.

Preferably, x+y≤90. Usually the sum of x and y is below 90.

More preferably, x:y=1:2.5-1:4.5, x+y=40-80, so that the maximum torque value of the screw column coated with the PBT composition is greater.

Preferably, the transesterification inhibitor is zinc dihydrogen phosphate.

The maximum torque value of coated screw columns is a very critical performance parameter of plastic parts with embedded screw columns. It is related to both the molding shrinkage rate and the cantilever notched impact strength. Either one of the molding shrinkage rate and the cantilever notched impact strength is taken. If the value is too low, the maximum torque value of the covered screw column will be low. During the research process, the inventor found that compared with other types of transesterification inhibitors (such as disodium hydrogen pyrophosphate DHPP), using zinc dihydrogen phosphate as the transesterification inhibitor can make the coated screw column of the PBT composition The maximum torque value is higher.

Preferably, the toughening agent is ethylene-acrylate-glycidyl methacrylate copolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate copolymer, methacrylate-styrene-organic silicon copolymer. , at least one of methacrylate-styrene-butadiene copolymers.

Preferably, the PBT composition also contains the following components by weight: 2 to 6 parts by weight of antimony-based flame retardant, and 0.3 to 1 part by weight of other additives. "Other additives" in this article refer to additives other than brominated PC, tougheners and transesterification inhibitors. The brominated PC in the PBT composition also has a flame retardant effect, and the flame retardant effect can be further improved by adding an antimony-based flame retardant; other additives can also be added according to actual needs.

Preferably, the antimony-based flame retardant is antimony trioxide.

Preferably, the other auxiliary agents include at least one of an antioxidant, a release agent, and an anti-drip agent. The antioxidant may be selected from at least one of hindered phenolic antioxidants or phosphite antioxidants, but is not limited thereto; the release agent may be selected from stearic acid metal salts, hardened At least one of fatty acid alkyl esters, pentaerythritol stearate, paraffin wax, and montan wax, but is not limited thereto; the anti-drip agent may be a polytetrafluoroethylene anti-drip agent, But it is not limited to this.

In a second aspect, the present invention provides a method for preparing the PBT composition, which includes the following steps: after uniformly mixing each raw material, melting, extruding, cooling, and granulating, the PBT composition is obtained. The preparation method of the PBT composition is simple and convenient for industrial production. In some examples, the melt extrusion temperature is 170-260°C.

In a third aspect, the present invention provides the use of the PBT composition in preparing embedded screw column inserts.

Compared with the prior art, the beneficial effects of the present invention are: the PBT composition of the present invention improves its Izod notched impact strength (A Type) is above 500J/m, the molding shrinkage is above 1%, and the maximum torque value of the coated screw column is above 27N·m. It is suitable for preparing embedded screw column inserts.

Description of the drawings

Figure 1 is a structural diagram of the injection molding of the PBT composition during the maximum torque value test.

Detailed ways

In order to better explain the purpose, technical solutions and advantages of the present invention, the present invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

The reagents, methods and equipment used in the present invention are all conventional reagents, methods and equipment in this technical field unless otherwise specified.

The raw materials used in each embodiment and comparative example are as follows:

PBT resin 1: intrinsic viscosity 0.72dl/g, PBT GX111, purchased from Yizheng Chemical Fiber Co., Ltd. manage;

PBT resin 2: intrinsic viscosity 0.80dl/g, PBT GX112, purchased from Yizheng Chemical Fiber Co., Ltd.;

PBT resin 3: intrinsic viscosity 1.0dl/g, PBT GX121, purchased from Yizheng Chemical Fiber Co., Ltd.;

PBT resin 4: intrinsic viscosity 1.16dl/g, PBT GX122J, purchased from Yizheng Chemical Fiber Co., Ltd.;

PBT resin 5: intrinsic viscosity 1.37dl/g, PBT GL236, purchased from Yizheng Chemical Fiber Co., Ltd.;

PC resin 1: melt index 3g/10min, PC 1300-03NP, purchased from LG Chem, South Korea;

PC resin 2: melt index 10g/10min, PC 1300-10NP, purchased from LG Chem, South Korea;

PC resin 3: melt index 22g/10min, PC 1300-22NP, purchased from LG Chem, South Korea;

Brominated PC 1: homemade, x+y=20, x:y=1:1.5;

Brominated PC 2: homemade, x+y=40, x:y=1:-2.5;

Brominated PC 3: homemade, x+y=60, x:y=1:3;

Brominated PC 4: homemade, x+y=80, x:y=1:4.5;

Brominated PC 5: homemade, x+y=90, x:y=1:6.5;

Brominated PC 6: BC-58, purchased from Lanxess Chemical (China) Co., Ltd.;

Brominated epoxy: F-2100, Israel Chemical;

Toughening agent 1: methacrylate-styrene-butadiene copolymer, M-521, Nakabuchi Chemical Industry Co., Ltd., Japan;

Toughening agent 2: ethylene-acrylate-glycidyl methacrylate copolymer, PTW, DuPont China Group Co., Ltd.;

Toughening agent 3: ethylene-acrylate copolymer, AC 1125, DuPont China Group Co., Ltd.;

Toughening agent 4: Ethylene-vinyl acetate copolymer, EVATANE 28-25, Arkema Shanghai Chemical Co., Ltd.;

Toughening agent 5: methacrylate-styrene-silicone copolymer, model S-2501, Mitsubishi Rayon Co., Ltd.;

Antimony trioxide: commercially available, the same substance is used in each example and comparative example;

Zinc dihydrogen phosphate: commercially available, the same substance is used in each example and comparative example;

DHPP: commercially available, the same substance is used in each example and comparative example;

Other additives: a mixture of antioxidant, release agent and anti-drip agent (the mass ratio of the three is 1:1:1), in which the antioxidant is IRGANOX 1010, the release agent is PETS-AP, and the anti-drip agent It is X-010, and the antioxidant, release agent and anti-drip agent used in each example and comparative example are all the same substances.

The structural formulas of brominated PC 1 to 5 are as follows:

Their preparation method includes the following steps: In a 500mL four-necked flask, put bisphenol A, tetrabromobisphenol A, sodium hydroxide solution sufficient to dissolve bisphenol A and tetrabromobisphenol A in proportion and a total amount of 0.1~ 5% catalyst tetrabutylammonium bromide is added dropwise to the 1,2-dichloroethane solution of triphosgene into the stirred mixed solution at 25-30°C. After the dripping is completed, the stirring reaction is continued for 2 hours. After the reaction is completed Let the solution stand, separate the organic phase, wash the organic phase repeatedly with deionized water, then drop the organic phase into methanol, and collect the precipitated polymer to obtain the target brominated PC, which is used in the above preparation of brominated PC 1 to 5 Reagents are all commercially available.

Each embodiment and comparative example respectively provides a PBT composition. Except for the formula, these PBT compositions have the same preparation process steps and other process parameters, specifically: after mixing all the raw materials evenly, at 170-260°C The PBT composition is obtained by melting and extruding through an extruder (length-to-diameter ratio: 42:1, rotation speed: 400 rpm), cooling, and granulating.

The following test methods were used to perform performance tests on the PBT compositions of each example and comparative examples:

Molding shrinkage: After the PBT composition particles are fully dried, pour them into the injection molding machine. Set the mold temperature to 80°C, the molding temperature to 260°C, the molding cycle to 30s, and injection mold a square plate of 2.0*50*200mm. Use a vernier caliper to measure the length of the square plate 5 times and calculate the average value. Then calculate the molding shrinkage according to the following formula:

Molding shrinkage = (200-average length of square plate)/200*100%,

The unit of the average length value of the square plate in the formula is mm;

The evaluation method of the maximum torque value is as follows: After the PBT composition particles are fully dried, pour them into the injection molding machine. Set the mold temperature to 80°C, the molding temperature to 260°C, and the molding cycle to 30 seconds. Injection mold it into the product as shown in Figure 1 (where the screw column is It is an M6 type screw column, K=4.0mm, S=10.0mm, H=10mm, L=30mm, W=16mm). After screwing on the nut, use a torque wrench to test the maximum torque value;

Izod notched impact strength: tested according to ASTM D256-2010 standard, type A notch.

Examples 1 to 12 and Comparative Examples 1 to 8

The formulas and performance results of the PBT compositions of Examples 1 to 12 and Comparative Examples 1 to 8 are shown in Tables 1 to 2 (units of each component are parts by weight).

Table 1

Table 2

It can be seen from Tables 1 to 2 that the PBT composition of the present invention has a high maximum torsion value of the coated screw column, which is above 27N·m, and the notched Izod impact strength (Type A) is above 500J/m, and the molding shrinkage rate Above 1%, it is suitable for preparing embedded screw column inserts. Without the addition of transesterification inhibitors, such as Comparative Example 3, the maximum torque value of the coated screw column will be significantly reduced; only adding PC resin or brominated PC, such as Comparative Examples 4 to 5, will result in the maximum torque value of the coated screw column being significantly reduced. Decrease; Adding brominated epoxy or conventional brominated polycarbonate flame retardant, such as Comparative Examples 1 to 2, will also cause the maximum torque value of the coated screw column to significantly decrease; Characteristics of PBT If the viscosity is too high or too low, and the melt index of the PC resin is too high, such as Comparative Examples 6 to 8, the maximum torque value of the coated screw column will be significantly reduced. Comparing Example 4 and Example 6, it can be seen that compared with ester exchange inhibitors such as DHPP, using zinc dihydrogen phosphate as an ester exchange inhibitor can obtain a higher maximum torque value of the coated screw column; Example 3 and Example 7 ~12 It can be seen that ethylene-acrylate-glycidyl methacrylate copolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate copolymer, methacrylate-styrene-organic silicon copolymer, methacrylic acid When at least one of the ester-styrene-butadiene copolymers is used as a toughening agent, the maximum torque values obtained for the coated screw columns are similar.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and do not limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that The technical solution of the present invention may be modified or equivalently substituted without departing from the essence and scope of the technical solution of the present invention.

Claims

A PBT composition, characterized in that it contains the following components by weight: 35 to 45 parts of PBT resin, 10 to 20 parts of PC resin, 25 to 40 parts of brominated PC, 5 to 15 parts of toughening agent, transesterification 0.1 to 0.3 parts of inhibitor, wherein the brominated PC is a random copolymer of triphosgene, tetrabromobisphenol A and bisphenol A, and the intrinsic viscosity of the PBT resin is 0.8 to 1.2 dl/g. The melt index of PC resin is ≤10g/10min. The melt index is measured in accordance with ASTM D1238-2010 standard at 300℃/1.2kg.
The PBT composition according to claim 1, wherein the structural formula of the brominated PC is as follows:

Among them, x:y=1:1.5-~1:6.5, x+y≥10.
The PBT composition of claim 2, wherein x+y≤90.
The PBT composition according to claim 3, wherein x:y=1:2.5～1:4.5, x+y=40～80.
The PBT composition of claim 1, wherein the transesterification inhibitor is zinc dihydrogen phosphate.
The PBT composition according to claim 1, wherein the toughening agent is ethylene-acrylate-glycidyl methacrylate copolymer, ethylene-acrylate copolymer, ethylene-vinyl acetate copolymer, At least one of methacrylate-styrene-silicone copolymer and methacrylate-styrene-butadiene copolymer.
The PBT composition according to claim 1, further comprising the following components by weight: 2 to 6 parts by weight of antimony-based flame retardants.
The PBT composition according to claim 1, further comprising the following components by weight: 0.3-1 parts by weight of other auxiliaries.
The preparation method of the PBT composition according to any one of claims 1 to 8, characterized in that: It includes the following steps: after mixing each raw material evenly, melting and extruding, cooling and granulating, the PBT composition is obtained.
Application of the PBT composition according to any one of claims 1 to 8 in the preparation of embedded screw column inserts.