A method for detecting gelation time of glue solution

Abstract

The present invention relates to the technical field of gelation time detection, and specifically to a method for detecting the gelation time of a glue solution. In the detection method of the present invention, firstly, the insoluble filler in the glue solution is removed by pre-treatment operation; secondly, a special detection accessory is introduced to create an inert gas atmosphere, which has a simple composition, is easy to clean, and has good compatibility; then, a specific test temperature is used, and the test temperature is adjusted according to different catalysts used in the glue solution to be tested; finally, an improved method for judging the end point of the gelation process is combined, so as to achieve the goal of obtaining accurate gelation time test results of non-epoxy resin system glue solution in a simple and low-cost manner.

Description

Technical Field

[0001] The invention relates to the technical field of gelation time detection, and in particular to a method for detecting the gelation time of a glue solution. Background Art

[0002] The gelation time refers to the time required for a liquid resin or glue to change from a flowing liquid to a solid state at a certain temperature. For thermosetting resins, gelation is an irreversible process and is highly related to the resin components, especially the content and type of the catalyst. The gelation process is the growth and cross-linking of the resin polymer chain segments. As the reaction proceeds, the increase in molecular chains leads to an increase in the overall viscosity of the system and eventually forms a resin cured product with greater mechanical strength. Therefore, the gelation time can characterize the reaction degree and activity of the liquid resin or glue.

[0003] Copper clad laminate is a plate-like material made by soaking electronic glass fiber cloth or other reinforcing materials in liquid resin glue to obtain a semi-cured sheet, then covering one or both sides with copper foil and hot pressing. It is referred to as copper clad laminate. It is widely used in many fields such as electronic devices, servers, satellite communications, and artificial intelligence. The processing process of copper clad laminate is the process of curing the resin in the raw material semi-cured sheet. Therefore, judging the conditions and time required for resin curing is of great significance to the copper clad laminate industry. If the resin cures too fast, the resin is not easy to level during the hot pressing process, which may lead to defects such as lack of glue in the product. On the contrary, if the resin cures too slowly, the glue flow during the pressing process is too large, and the product is prone to problems such as white edges and white corners. Therefore, by testing the gelation time of the glue solution for producing semi-cured sheets, its approximate composition and the conditions required for the reaction can be mastered, thereby effectively controlling product quality and guiding further processing technology, which is of great significance to actual production.

[0004] At present, the various existing gelation time test methods and national standards are mainly aimed at traditional epoxy resin system liquid resin glue (such as SJ / T 11197-2013 epoxy molding compound; IPC-TM-650 2.3.18 gelation time of prepreg; GB / T 33316-2016 determination of the reactivity of phenolic resin on the B-stage transformation test plate, etc.). At present, with the development of copper clad laminate industry technology, more different resin systems have been developed, such as BT resin, cyanate resin, polyimide resin and other resin systems commonly used in high-frequency and high-speed copper clad laminate products. For these resin systems, due to the large difference between the catalysts used (metal complexes, peroxides, etc.) and traditional epoxy resins (amines, phenols, etc.), the original test methods have many problems in the actual application process, which is usually manifested as when the test sample is stirred with a stirring rod to judge the gelation end point according to the resistance, the final viscosity of the system has no obvious change, and the judgment standard depends on the operator's manual feeling, and the test results have large errors and lack of reproducibility. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for detecting the gelation time of a glue solution.

[0006] One object of the present invention is achieved by the following technical solutions:

[0007] A method for detecting gelation time of glue liquid, the method comprising the following steps: (1) pre-treating the glue liquid; (2) adding the pre-treated glue liquid into a detection accessory; (3) adjusting the test temperature of a gelation time tester; (4) placing the detection accessory with the glue liquid into the gelation time tester and performing a test;

[0008] The detection accessory includes a chassis and a protective cover, and a heat insulating pad is used to seal between the chassis and the protective cover; a one-way exhaust valve and a sealing ring are arranged on the top of the protective cover; a stirring rod is arranged to pass through the sealing ring to stir the glue inside the detection accessory.

[0009] The detection accessory provided by the present invention has the advantages of being detachable and easy to clean; the one-way exhaust valve is used to remove the steam from the evaporated solvent to avoid excessive pressure in the device; and a stirring rod is provided to stir the glue to be tested so that it is heated evenly.

[0010] Preferably, the detection attachment is cylindrical, with a diameter of 10-30 mm and a total height of 1-10 cm.

[0011] Preferably, the height of the chassis is 1~6 cm, the height of the protective cover is 1~6 cm, the height difference between the chassis and the protective cover is 1~2 cm, and the height of the thermal insulation pad is 0.1~2 cm.

[0012] Further preferably, the detection accessory is cylindrical, with a diameter of 18~22mm and a total height of 3~5cm; the height of the chassis is 1~3cm, the height of the protective cover is 1~3cm, and the height of the thermal insulation pad is 0.1~1cm.

[0013] Conventional gelation time testing equipment only uses an open hot plate for heating, and the device is simple, so it is widely used. However, to detect the gelation time of non-epoxy resin system liquid resin glue, an inert gas environment must be provided. The conventional laboratory method is to use a vacuum pump for ventilation or nitrogen bubbling for degassing, and the device is complex and costly. The above-mentioned detection accessory for the gelation time of the glue is specially made by the present invention, which can be placed in the concave hot plate of a common commercially available gelation time tester. When detecting the gelation time of non-epoxy resin system liquid resin glue, there is no need to modify the existing experimental instruments, making the operation more convenient and further reducing the testing cost.

[0014] Preferably, the chassis is made of stainless steel, the protective cover is made of glass, the thermal insulation pad is made of rubber, and the sealing ring is made of rubber.

[0015] Preferably, in step (1), the glue is a non-epoxy resin system glue, that is, the glue does not include epoxy resin. The non-epoxy resin system glue includes reactive resins, and the reactive resins include but are not limited to one or more of BT resins, cyanate resins, polyimide resins, phenolic resins, polytetrafluoroethylene resins, and polyurethane resins.

[0016] Non-epoxy resin system glue is usually processed from non-epoxy system reactive resins, solvents, coupling agents, fillers, flame retardants, catalysts and other components, among which the component that reacts during the production process is the reactive resin.

[0017] Furthermore, in the step (1), the adhesive is an adhesive for high-frequency and high-speed copper-clad laminates.

[0018] Preferably, in step (1), the pretreatment of the glue solution comprises the following steps: removing the insoluble filler in the glue solution by one or more methods selected from the group consisting of centrifugation, decanting, and atmospheric filtration. The insoluble filler may be one or more selected from the group consisting of silicon dioxide, aluminum oxide, mica powder, barium titanate, calcium carbonate, ceramic particles, carbon nanotubes, and graphene.

[0019] The pretreatment step of the glue solution preferably further includes adding a solvent of 10 to 200% of the mass of the glue solution before removing the insoluble filler. The solvent can be one or more of acetone, ethanol, isopropanol, ethyl acetate, toluene, xylene, chloroform, and dichloromethane.

[0020] In the actual production process, a large amount of inert insoluble fillers are usually added to the glue in order to improve the mechanical properties and dielectric properties of the product. More fillers will make the resin have a greater viscosity before it is completely cured, thereby interfering with the judgment of the end point of the gelation time, and also causing trouble for the cleaning of the equipment after the detection is completed. The present invention removes these fillers during the pre-treatment process, which is conducive to judging the actual curing situation of the glue and is also convenient for cleaning the glue after curing.

[0021] Preferably, in step (2), the amount of the glue added to the detection accessory is 0.1-3.0 g, more preferably 0.2-1.0 g.

[0022] If the amount of glue is too little, the glue will easily disperse and adhere to the bottom and wall of the container, resulting in unclear agglomeration of the glue at the end of gelation; if the amount of glue is too much, too much solvent will be introduced, which will absorb too much heat after evaporation, reducing the temperature of the hot plate of the gelation time tester and interfering with the test results.

[0023] Preferably, in step (2), the protective cover of the detection accessory is opened, the pre-treated glue is added, and then the protective cover is closed.

[0024] Preferably, in step (3), the test temperature of the gelation time tester is adjusted to T-10°C to T+30°C, where T is the 0.1h half-life temperature of the catalyst used in the gel solution.

[0025] When conducting a gel time test, appropriately increasing the test temperature can promote rapid solidification of the glue and shorten the test time. However, too high a test temperature will also cause the glue to solidify too quickly, resulting in an increase in the error introduced when manually judging the endpoint.

[0026] Preferably, in step (4), the test accessory with the gel solution added thereto is placed on a hot plate of a gel time tester and preheated for 10 to 30 seconds before stirring the gel solution to be tested and timing.

[0027] In the step (4), the detection is performed under an inert gas atmosphere, wherein the inert gas is the steam generated by the preheating and volatilization of the solvent added during the pretreatment process in the step (1).

[0028] In the detection method of the present invention, the glue liquid is preheated to generate steam through the volatilization of the solvent in the glue liquid, so as to remove the oxygen in the device and form an inert gas atmosphere; if preheating is not performed, the stirring is started too early and the oxygen in the device is not completely removed; if the preheating time is too long, the stirring is started too late, which will cause the glue liquid to partially solidify. Both situations will cause the detection result to deviate from the actual value.

[0029] Preferably, in step (4), the method for determining the gelation endpoint is as follows: when the liquid gel to be tested turns into a solid block and completely adheres to the stirring rod of the detection accessory, the gelation endpoint is reached.

[0030] Different from the traditional method of judging the gelation time based on the stirring resistance or whether the glue block is completely separated from the hot plate, the present invention can eliminate the influence of the difference in mechanical strength of the solidified material after the glue is solidified by judging whether the block glue is completely agglomerated and adhered to the stirring rod. For glue with low mechanical strength of some solidified materials, even when the end point is reached, the stirring resistance of the glue system is still low and it is easy to form a wire drawing phenomenon with the hot plate, which interferes with the end point judgment of the traditional test method. For the end point judgment method of the present invention, since the main part of the glue is concentrated on the stirring rod, it is easier to separate from the bottom of the device, and the end point is easier to judge.

[0031] The second object of the present invention is achieved by the following technical solutions:

[0032] A method for detecting the gelation time of glue is used in detecting the gelation time of glue for high-frequency and high-speed copper-clad laminates.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. In a method for detecting the gelation time of a glue provided by the present invention, through pre-treatment operations, the introduction of special detection accessories to create an inert gas atmosphere, and the adjustment of the test temperature, combined with an improved method for determining the end point of the gelation process, the accurate gelation time test results of non-epoxy resin system glue can be obtained simply and at low cost.

[0035] 2. The present invention adopts a special detection accessory to detect the gelation time of the glue. The detection accessory is simple in composition and easy to clean. It can conveniently provide an inert gas atmosphere and continuous heating conditions, and has good compatibility with currently commercially available gelation experimental testers, which is easy to promote and compatible with traditional gelation time test methods.

[0036] 3. In a method for detecting the gelation time of a glue provided by the present invention, a pre-treatment method of removing insoluble fillers in the glue is adopted, which can avoid the situation where a large amount of fillers in the glue before treatment causes the resin to have a greater mechanical strength before it is completely cured, thereby interfering with the judgment of the end point of the gelation time. Therefore, an accurate result of the gelation time of the glue can be obtained, and it is also convenient for cleaning the equipment.

[0037] 4. In the method for detecting the gelation time of the glue provided by the present invention, the gelation time of the glue is tested under inert gas conditions, which can eliminate the influence of oxygen in the air on the glue catalyst, thereby obtaining accurate measurement results.

[0038] 5. In a method for detecting the gelation time of a glue provided by the present invention, a specific test temperature is adopted. The test temperature is adjusted according to the different catalysts used in the glue to be tested, which can promote the rapid solidification of the glue and shorten the test time. At the same time, it can also avoid the glue from solidifying too quickly, which leads to an increase in the error introduced when manually judging the end point, thereby improving the test efficiency and the accuracy of the results.

[0039] 6. The present invention provides a method for detecting the gelation time of glue, which is used to detect the gelation time of glue for high-frequency and high-speed copper-clad laminates of non-epoxy resin systems, thereby solving the problem that traditional detection methods will produce large errors when detecting glue for high-frequency and high-speed copper-clad laminates of non-epoxy resin systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The structure diagram of the detection accessory for detecting the gelation time of the glue in the embodiment of the present invention is shown in FIG. 1 is a protective cover; 2 is a heat insulation pad; 3 is a chassis; 4 is a one-way exhaust valve; 5 is a sealing ring; and 6 is a stirring rod. DETAILED DESCRIPTION

[0041] The technical solution of the present invention is further described below in conjunction with specific embodiments and drawings. It should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not used to limit the scope of the present invention. And the drawings used herein are only for better illustrating the disclosed content of the present invention and do not have a limiting effect on the scope of protection. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0042] The detection attachment structure used in the following embodiments is as follows Figure 1 shown.

[0043] It can be seen that the detection accessory includes a chassis 3 and a protective cover 1, and a thermal insulation pad 2 is used to seal between the chassis 3 and the protective cover 1; a one-way exhaust valve 4 and a sealing ring 5 are arranged at the top of the protective cover; the detection accessory is also provided with a stirring rod 6 passing through the rubber sealing ring 5, which is used to stir the glue to be tested inside the detection accessory; the detection accessory is cylindrical, with a diameter of 20 mm and a total height of 4 cm, the chassis 3 is 1.8 cm high, the protective cover 1 is 1.8 cm high, and the thermal insulation pad 2 is 0.4 cm high; the chassis 3 is a stainless steel chassis, the protective cover 1 is a transparent glass protective cover, the thermal insulation pad 2 is a rubber thermal insulation pad, the sealing ring 5 is a rubber sealing ring, and the stirring rod 6 is a disposable wooden stirring rod.

[0044] Example 1

[0045] The method for detecting the gelation time of the glue solution in this embodiment comprises the following steps:

[0046] (1) Take 5g of the adhesive solution for the high-frequency and high-speed copper-clad laminate to be tested (the adhesive solution composition raw materials: 30wt% acetone solvent, 40wt% BT resin, 0.5wt% coupling agent, 29wt% silica insoluble filler, 0.5wt% TBPO catalyst), add 5g of acetone, shake and stir thoroughly, let it stand for 5 minutes, decant and remove 90wt% of the insoluble filler, and then filter under normal pressure to remove the remaining 10wt% of the insoluble filler;

[0047] (2) Open the glass protective cover of the detection accessory, take 0.5g of filtrate and add it into it, cover it with the glass protective cover and set aside;

[0048] (3) Adjust the test temperature of the gelation time tester to 133°C (the gel catalyst used is TBPO, and the 0.1h half-life is 113°C);

[0049] (4) Place the test accessory with the glue added on the hot plate of the gelation time tester and preheat for 20 seconds to remove the oxygen in the test accessory. After forming an acetone vapor atmosphere, stir the glue from the inside to the outside in a circle at a speed of 120 circles per minute and start timing. Stop timing when the glue becomes a block and completely adheres to the stirring rod, and record the gelation time ST.

[0050] Comparative Example 1

[0051] The gelation time ST of the glue for the high-frequency and high-speed copper-clad laminate to be tested is tested using the IPC standard IPC-TM-650 2.3.18 method.

[0052] The above-mentioned embodiment and comparative example were tested repeatedly for 5 times, and the gelation time was recorded as ST1-5. The standard deviation and relative standard deviation were calculated. The specific result data are shown in Table 1.

[0053] Table 1 Test results of gelation time of examples and comparative examples

[0054]

[0055] As can be seen from Table 1, the detection method of the gelation time of the glue of the present invention is used to detect the glue for high-frequency and high-speed copper-clad laminates of non-epoxy resin systems. Compared with the conventional standard detection method, the error is smaller and the detection result is more accurate. Since the curing temperature used in the traditional gelation time test method (IPC standard IPC-TM-650 2.3.18) is a fixed value, and the catalyst (TBPO, catalytic temperature of 80-150°C) of the common non-epoxy resin system high-frequency and high-speed copper-clad laminate glue is too high, it will cause the polymerization reaction to proceed too quickly in an inert gas environment, causing the solidified material to be in a tofu dregs shape due to violent polymerization, affecting the judgment of the end point of the gelation time, and also causing a large error in the measured value.

[0056] The various aspects, embodiments, and features of the present invention should be considered to be illustrative in all aspects and not limiting of the present invention, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0057] In the preparation method of the present invention, the order of each step is not limited to the order listed. For those skilled in the art, without creative work, the order of each step is also within the protection scope of the present invention. In addition, two or more steps or actions can be performed simultaneously.

[0058] Finally, it should be noted that the specific embodiments described herein are merely examples of the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described, or replace them in a similar manner. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for detecting the gelation time of a glue solution, characterized in that: The detection method comprises the following steps: (1) pre-treating the glue solution; (2) adding the pre-treated glue solution into the detection accessory; (3) adjusting the test temperature of the gelation time tester; (4) placing the detection accessory with the glue solution into the gelation time tester and performing the test; The detection accessory comprises a chassis and a protective cover, and a heat-insulating pad is used to seal between the chassis and the protective cover; a one-way exhaust valve and a sealing ring are arranged at the top of the protective cover; a stirring rod is arranged to pass through the sealing ring to stir the glue liquid inside the detection accessory; the chassis is made of stainless steel, the protective cover is made of glass, the heat-insulating pad is made of rubber, and the sealing ring is made of rubber; The pretreatment of the glue solution comprises the following steps: removing the insoluble filler in the glue solution by one or more methods selected from the group consisting of centrifugation, decantation and normal pressure filtration; The pre-treatment step of the glue solution also includes adding 10 to 200% of the mass of the glue solution as solvent before removing the insoluble filler; In the step (3), the test temperature of the gelation time tester is adjusted to T-10°C to T+30°C, where T is the 0.1h half-life temperature of the catalyst used in the gel solution; In the step (4), the test accessory with the gel solution added is placed on the hot plate of the gel time tester for preheating for 10 to 30 seconds before stirring the gel solution to be tested and timing; In the step (4), the detection is performed under an inert gas atmosphere, wherein the inert gas is the steam generated by the preheating and volatilization of the solvent added during the pretreatment process in the step (1).

2. The method for detecting the gelation time of a glue solution according to claim 1, characterized in that: The detection attachment is cylindrical, with a diameter of 10-30 mm and a total height of 1-10 cm.

3. The method for detecting gelation time of a glue solution according to claim 1, characterized in that: The height of the chassis is 1-6 cm, the height of the protective cover is 1-6 cm, the height difference between the chassis and the protective cover is 1-2 cm, and the height of the thermal insulation pad is 0.1-2 cm.

4. The method for detecting gelation time of a glue solution according to claim 1, characterized in that: In the step (1), the glue is a non-epoxy resin system glue.

5. The method for detecting gelation time of a glue solution according to claim 1, characterized in that: In the step (2), the amount of glue added to the detection attachment is 0.1-3.0 g; In the step (2), the protective cover of the detection accessory is opened, the pre-treated glue is added, and then the protective cover is closed.

6. The method for detecting gelation time of a glue solution according to claim 1, characterized in that: In the step (4), the method for determining the gelation endpoint is as follows: when the liquid test gel solution turns into a solid block and completely adheres to the stirring rod of the detection accessory, the gelation endpoint is reached.

7. An application of the method for detecting the gelation time of glue as claimed in any one of claims 1 to 6 in detecting the gelation time of glue for high-frequency and high-speed copper-clad laminates.

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