阅读说明：本技术 一种降低聚碳酸酯及其改性产品内应力的方法 (Method for reducing internal stress of polycarbonate and modified product thereof ) 是由 陈晶斌 张振威 李万庆 高卫强 于 2019-11-25 设计创作，主要内容包括：本发明提供了一种降低聚碳酸酯及其改性产品内应力的方法,包括以下步骤：将聚碳酸酯或其改性产品制件在醇溶液中浸泡处理,处理时间为0.1～2h,温度为0～50℃。本发明研究发现,低浓度的小分子醇溶液可以促进聚碳酸酯及其改性产品应力集中点的分子链重排,进而降低聚碳酸酯及其改性产品的内应力,有利于在不影响制件尺寸稳定性的情况下改善产品内应力,防止因内应力较大导致的产品翘曲变形、银纹、抗冲性不强等现象。(The invention provides a method for reducing internal stress of polycarbonate and a modified product thereof, which comprises the following steps: soaking the polycarbonate or the modified product workpiece thereof in an alcohol solution for 0.1-2 h at 0-50 ℃. The research of the invention finds that the low-concentration micromolecular alcohol solution can promote the molecular chain rearrangement of the stress concentration point of the polycarbonate and the modified product thereof, further reduce the internal stress of the polycarbonate and the modified product thereof, be beneficial to improving the internal stress of the product under the condition of not influencing the dimensional stability of the finished piece, and prevent the phenomena of warping deformation, silver streaks, weak impact resistance and the like of the product caused by large internal stress.)

1. A method for reducing the internal stress of polycarbonate and modified products thereof, which is characterized by comprising the following steps: soaking the polycarbonate or the modified product workpiece thereof in an alcohol solution for 0.1-2 h at 0-50 ℃.

2. The method for reducing the internal stress of polycarbonate and modified products thereof according to claim 1, wherein the alcohol solution is an aqueous solution with an alcohol content of 0.5-10 wt%, preferably an aqueous solution with an alcohol content of 0.8-5 wt%.

3. The method for reducing the internal stress of the polycarbonate and the modified product thereof according to claim 1 or 2, wherein the alcohol in the alcohol solution is a C1-3 small molecule monohydric alcohol and/or polyhydric alcohol.

4. The method for reducing the internal stress of polycarbonate and modified products thereof as claimed in claim 3, wherein the alcohol in the alcohol solution is monohydric alcohol and/or polyhydric alcohol with hydroxyl number less than or equal to 3.

5. The method for reducing the internal stress of polycarbonate and modified products thereof as claimed in claim 4, wherein the alcohol in the alcohol solution is one or more of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, 1, 2-propanediol, 1, 3-propanediol and glycerol.

6. The method for reducing the internal stress of the polycarbonate and the modified product thereof according to any one of claims 1 to 5, wherein the soaking treatment time of the alcoholic solution is 0.3 to 1.5 hours.

7. The method for reducing the internal stress of the polycarbonate and the modified product thereof according to any one of claims 1 to 6, wherein the temperature of the alcoholic solution soaking treatment is 10 to 45 ℃.

8. The method for reducing the internal stress of polycarbonate and modified products thereof according to any one of claims 1 to 7, wherein the polycarbonate is pure polycarbonate with a melt flow index of 3 to 65g/10min, preferably 5 to 50g/10min, more preferably 7 to 35g/10min at 300 ℃ and 1.2 kg.

9. The method for reducing the internal stress of the polycarbonate and the modified product thereof as claimed in any one of claims 1 to 8, wherein the polycarbonate modified product comprises polycarbonate/ABS alloy, polycarbonate/PBT alloy, polycarbonate/PET alloy, polycarbonate/ASA alloy and polycarbonate toughening product.

10. The method of reducing the internal stress of polycarbonates and their modified products as claimed in claim 9, wherein said polycarbonate/ABS alloy comprises wanhua chemical CA1356, CA1450, CA1510PG, CA1560, CA1630, CA1660, CA1730, blonde MAC301, MAC451, MAC501, MAC601, MAC701, MAC751, platformized AC2000, AC2300, AC2500, AC3100, qimei PC-330, PC-345, PC-365, PC-385, kesikogaku T45PG, T50XF, T1014 65XF, T65PG, T85XF, T90XF, priatecb 1230, 234cb 0, lentian GW-1011, HA-1011, HP-1000H, HP-1000P, sabick C1200HF, SCY620S, SCY630, MC 1300; LG chemical HR5007A, GP5006B, GP5008A, HG5000S, HI5002A, HR5007AT, NS 5000;

preferably, the polycarbonate/PBT alloy comprises wanhua chemical CB1221, CB1321, CB3250, CB, koshiwa UT5205, UT4045G, UT6007, S7916, sabik 5720U, X5600WX, X4820, X4830, X4850, 1670E, 6370, V3900W, jinhu rili HCB9230, HCB9240, HCB9310G, LG chemical TE5011, TE5011M, jinfa Lonoy 1200, Lonoy 1600.

Preferably, the polycarbonate/PET alloy comprises warfarin CE1631, CE1820, CE6820, corcesin DP7645, DP7665, UT203, UT305, UT403, UT408, EL700, EL703, sabick X2300UV, X2500UV, XL1339, X5630Q, brocade lake helio HTC6060, KCA9360, KCA9362, KCA9341, blonoy 2100 LT.

Preferably, the polycarbonate/ASA alloy comprises wanhua chemistry CS1530, CS1730, sabik HRA222, XP4025, XP4034, XP7550, XP7560, jinhu rai HSC7045, HSC7060, HSC 7079Z.

Preferably, the polycarbonate toughened product comprises Wanhua chemical CR1821, CR1840, Letian CF-1070, LG chemical SC 1004A.

Technical Field

The invention relates to an internal stress treatment method, in particular to a method for reducing the internal stress of polycarbonate and a modified product thereof, belonging to the technical field of polycarbonate materials.

Background

Polycarbonate and a modified product thereof mean a composition containing polycarbonate as a main component, and are very common materials in daily life. Because of good mechanical property, heat resistance, appearance property and excellent processing property, the polycarbonate and the modified products thereof are widely applied to the fields of automobiles, electronic and electrical equipment, illumination, medical appliances, national defense industry and the like.

However, because the polycarbonate molecular chain has high rigidity, the products of the polycarbonate and the modified products thereof are easy to have relatively large internal stress. These internal stresses can cause undesirable phenomena such as warping, deformation, crazing and the like in the use process of the polycarbonate and the modified product thereof in the future. Especially, under the impact of external force, the polycarbonate and the modified products thereof are easy to crack, break and other failure behaviors.

The main method for eliminating the internal stress of polycarbonate plastic products is annealing, in particular, polycarbonate and modified products thereof are placed in a higher temperature environment for a period of time and then are controlled to cool at a proper speed. Publication CN106832377A describes a method for preparing a polycarbonate optical spherical cap, which reduces the internal stress of the product by heat treatment. The patent publication CN108016023A describes a preparation method of polylactic acid and a copolymer stent thereof, and the internal stress of a tube can be effectively released by placing the tube after inflation at an annealing temperature for annealing for 5-30 minutes, so that the shelf life of the stent can be prolonged.

Although the annealing process can reduce the internal stress of polycarbonate and modified products thereof at present, the heat treatment of workpieces can cause the defect of changing the size of products, which cannot meet the application requirements in the field with higher requirements on the size of the products.

Disclosure of Invention

The invention aims to provide a method for reducing internal stress of polycarbonate and a modified product thereof, and the internal stress of the product can be obviously reduced under the condition of no size change of the polycarbonate and the modified product thereof treated by the method, thereby being beneficial to prolonging the service life and the application range of the product.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for reducing the internal stress of polycarbonate and modified products thereof, comprising the steps of: soaking the polycarbonate or the modified product workpiece thereof in an alcohol solution for 0.1-2 h at 0-50 ℃.

Further, the alcohol solution is an aqueous solution with the alcohol content of 0.5-10 wt%, and preferably an aqueous solution with the alcohol content of 0.8-5 wt%.

Further, the alcohol in the alcohol solution is C1-3 small molecular monohydric alcohol and/or polyhydric alcohol.

Further, the alcohol in the alcohol solution is monohydric alcohol and/or polyhydric alcohol with the hydroxyl number less than or equal to 3.

Further, the alcohol in the alcohol solution is one or more of methanol, ethanol, ethylene glycol, n-propanol, isopropanol, 1, 2-propanediol, 1, 3-propanediol and glycerol.

Further, the alcoholic solution soaking treatment time is 0.3-1.5 h.

Further, the temperature of the alcoholic solution soaking treatment is 10-45 ℃.

Further, the polycarbonate is pure polycarbonate with a melt flow index of 3-65 g/10min, preferably 5-50 g/10min, and more preferably 7-35 g/10min at 300 ℃ and 1.2 kg.

Further, the polycarbonate modified product comprises polycarbonate/ABS alloy, polycarbonate/PBT alloy, polycarbonate/PET alloy, polycarbonate/ASA alloy and polycarbonate toughening product.

Further, the polycarbonate/ABS alloy comprises a product with the following information of product sale brand: vanhua chemical CA1356, CA1450, CA1510PG, CA1560, CA1630, CA1660, CA1730, golden hair MAC301, MAC451, MAC501, MAC601, MAC701, MAC751, Taiwan chemical AC2000, AC2300, AC2500, AC3100, Qimei PC-330, PC-345, PC-365, PC-385, Corsaikosa T45PG, T50XF, T65XF, T65PG, T85XF, T90XF, Pridel CB1230, CB2340, Letian GW-1014, HA-1011, HP-1000H, HP-1000P, Sabike C1200HF, SCY620S, SCY630, MC 1300; LG chemical HR5007A, GP5006B, GP5008A, HG5000S, HI5002A, HR5007AT, NS 5000;

preferably, the polycarbonate/PBT alloy comprises a product having a product sales designation of: wanhua chemical CB1221, CB1321, CB3250, CB, Corsichu UT5205, UT4045G, UT6007, S7916, Saebik 5720U, X5600WX, X4820, X4830, X4850, 1670E, 6370, V3900W, Jinhui Nieli HCB9230, HCB9240, HCB9310G, LG chemical TE5011, 5011M, Jinfa Lonoy 1200 and Lonoy 1600.

Preferably, the polycarbonate/PET alloy comprises a product sold under the following information: wanhua chemical CE1631, CE1820, CE6820, Corsaikoku DP7645, DP7665, UT203, UT305, UT403, UT408, EL700, EL703, sabick X2300UV, X2500UV, XL1339, X5630Q, Jinhuilanli HTC6060, KCA9360, KCA9362, KCA9341, and Jinfa lonoy 2100 LT.

Preferably, the polycarbonate/ASA alloy comprises the following information on the product sale: wanhua chemical CS1530, CS1730, Saebick HRA222, XP4025, XP4034, XP7550, XP7560, Jinhuili HSC7045, HSC7060, HSC7079 and HSC 7079Z.

Preferably, the polycarbonate toughened product comprises a product having a product sales designation of: wanhua chemical CR1821, CR1840, Letian CF-1070, LG chemical SC 1004A.

The forming method of the polycarbonate and the modified product thereof comprises but is not limited to injection molding, extrusion, blow molding, casting, pressing, 3D printing and the like.

The research of the invention finds that the low-concentration micromolecular alcohol solution can promote the molecular chain rearrangement of the stress concentration point of the polycarbonate and the modified product thereof, further reduce the internal stress of the polycarbonate and the modified product thereof, be beneficial to improving the internal stress of the product under the condition of not influencing the dimensional stability of the finished piece, and prevent the phenomena of warping deformation, silver streaks, weak impact resistance and the like of the product caused by large internal stress.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to be illustrative of the invention and are not to be construed as limiting the scope of the invention.

The raw materials and sources of the product are as follows:

a1105, pure polycarbonate product, melt flow index 10g/10min (test conditions 300 ℃, 1.2kg), Vanhua chemical group GmbH;

CA1560, polycarbonate/ABS products, Vanhua chemical group, Inc.;

CB1221, polycarbonate/PBT products, Vanhua chemical group, Inc.;

CE1631, polycarbonate/PET products, Vanhua chemical group, Inc.;

CS1530, polycarbonate/ASA products, Vanhua chemical group, Inc.;

CR1840, polycarbonate toughened products, Vanhua chemical group, Inc.

The polycarbonate and the modified product thereof are used for preparing tensile sample strips and square plate sample strips by injection molding. Wherein tensile bars are used to test internal stresses and have dimensions in accordance with ASTM D638; the square plate bars were used to test the dimensional stability and had dimensions of 365mm by 100mm by 3 mm.

(1) The concrete operation steps of soaking the sample strips by the alcohol solution are as follows:

and (3) pouring the alcohol solution with the specific solubility into a beaker, placing the beaker into a water bath kettle, and regulating the temperature of the alcohol solution through the water bath kettle. The stretched and square plate bars were placed in an alcohol solution to completely submerge all bars. After a specified time of soaking, all the strips were removed from the alcohol solution and rinsed in running water for 2 minutes and then wiped dry with a paper towel.

(2) The specific operation steps for processing the sample strip by annealing are as follows:

and putting the stretched sample strips and the square plate sample strips into an oven, heating at a specific temperature for a specific time, taking all the sample strips out of the oven, and naturally cooling for later use.

(3) Internal stress testing method

And bending the treated tensile sample strip along the arc curved surface, so that the whole sample strip is tightly attached to the arc curved surface and fixed. And selecting a proper arc surface to ensure that the bending deformation of the tensile sample strip reaches 1.5 percent. The middle part of the tensile sample strip was wiped with absorbent cotton stained with carbon tetrachloride, and the time at which the tensile sample strip cracked was observed and recorded. Longer times represent less internal stress.

(4) Dimensional stability test method

The dimensions of the long side of the square plate bar before and after the treatment were recorded, and the amount of change was calculated.

Examples 1 to 12 were set up according to method (1) except that the polycarbonate samples shown in Table 1 were immersed in an alcohol solution, and the difference in treatment temperature and time was observed;

comparative examples 1 to 6 were set according to the method (2) except for differences in heat treatment temperature, time of the polycarbonate samples shown in Table 1;

the samples without any treatment were designated as comparative examples 7 to 12, respectively, differing only in the polycarbonate samples shown in Table 1.

TABLE 1 Distinguishing parameters in the examples and comparative examples

The samples of the examples and comparative examples were tested for internal stress and dimensional stability according to the methods of (3) and (4), and the test results are shown in table 2:

table 2 results of performance testing

Note: the size change value is a positive number, which indicates that the size becomes larger; the dimensional change value is negative, indicating a decrease in size.

By comparing examples 1-12 with comparative examples 7-12, it can be seen that, after the treatment of soaking in an alcohol solution, whether pure polycarbonate or various polycarbonate-modified products, the time for cracks to appear in the tensile bar stress test is obviously increased, which indicates that the internal stress of the products is obviously reduced, and proves that the treatment of an alcohol aqueous solution is an effective method for reducing the internal stress of the polycarbonate and the modified products thereof.

As can be seen from the comparison of examples 1 to 12 with comparative examples 1 to 6, the polycarbonate and the modified product thereof underwent annealing treatment, and although the time for occurrence of cracks became long, the square plate bars correspondingly underwent a large change in size, indicating that the heat treatment deteriorated the dimensional stability of the polycarbonate and the modified product thereof. After the polycarbonate and the modified product thereof are soaked in the alcohol solution, not only the internal stress is reduced, but also the size of the sample strip is almost unchanged, which shows that compared with the traditional annealing treatment method, the solution soaking method has the advantage of not influencing the dimensional stability of the polycarbonate and the modified product thereof, and is suitable for large-scale popularization and application.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and additions can be made without departing from the method of the present invention, and these modifications and additions should also be regarded as the protection scope of the present invention.