Rapid detection method for operable time of dynamic viscosity of epoxy resin

Abstract

The invention discloses a method for rapidly detecting the operable time of the dynamic viscosity of epoxy resin, and belongs to the technical field of epoxy resin, and the method comprises the following steps: preparing an epoxy resin adhesive, adding 100 parts of epoxy resin, 30-80 parts of a curing agent and 0-10 parts of an accelerant into 100 parts of a solvent, and stirring until the epoxy resin, the curing agent and the accelerant are completely dissolved; turning on a gelation time tester, setting the temperature to be 171 DEG C, and stabilizing for 10 minutes; 3 drops of the prepared glue solution are dropwise added in the middle of a hot plate, a toothpick is used for clockwise stirring at the speed of 2 circles per second, a solvent in the glue solution volatilizes along with time, the viscosity is gradually increased, the toothpick is slightly picked up during the period, the time when the glue solution can be picked up by 1-2 cm without breakage is recorded as t1, the time when the glue solution is gathered into a cluster at the center is recorded as t2, and t3 is recorded as t2; recording the time when the glue solution is completely cured and picked up, and recording the time as t3; judging the gelation time and the dynamic viscosity operable time of the sample according to the recorded time; the method has the advantages of low cost, simple operation and short time consumption in the detection process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of epoxy resin, and particularly relates to a rapid detection method for dynamic viscosity and operable time of epoxy resin. BACKGROUND

[0002] Epoxy resin refers to a kind of high molecular compound containing two or more than two epoxy groups in the molecule, which can be used with various curing agents such as amine, acid anhydride and phenolic resin to form a three-dimensional network curing product. It is a thermosetting polymer synthetic material with good bonding, corrosion resistance, electrical insulation, high strength and other properties.

[0003] Viscosity and gel time are very important performance indicators of epoxy resin. Viscosity directly affects the flowability, curing time and curing effect of the resin, and the epoxy resin curing process needs to go through gelation, operability, surface drying and hardening stages, and the length of gel time directly affects the performance of the cured epoxy resin, such as hardness and toughness.

[0004] In actual application, the viscosity change of epoxy resin before curing is usually considered to make it have operability in a lower viscosity range, and the length of operable time determines the application range and processing mode of the epoxy resin. At present, the complex viscosity of epoxy resin is mainly tested by using a rheometer, however, this method has the problem of high instrument testing cost, and the testing is generally to observe the viscosity change of the sample from low temperature to high temperature, and in actual application, part of the products need to be processed at a constant temperature. Therefore, an innovative, low-cost and simple epoxy resin dynamic viscosity operable time rapid detection method is urgently needed. SUMMARY

[0005] In order to overcome the above problems, the application provides a rapid detection method for dynamic viscosity and operable time of epoxy resin, which can observe the viscosity change of the epoxy resin in the testing process to represent its dynamic viscosity and operable time while testing the gel time of the epoxy resin.

[0006] The technical scheme adopted by the application is: A rapid detection method for dynamic viscosity and operable time of epoxy resin, comprising the following steps: Step 1: preparing epoxy resin adhesive, adding 100 parts of epoxy resin, 30-80 parts of curing agent and 0-10 parts of accelerator into 100 parts of solvent, and stirring until completely dissolved; Step 2: turning on the gel time tester, setting the temperature to 171 DEG C, and stabilizing for 10 minutes; Step three: drop 3 drops of prepared glue liquid in the middle of the hot plate, stir clockwise with toothpick at a speed of 2 circles per second, the solvent in the glue liquid volatilizes over time, the viscosity gradually increases, during which the toothpick is gently lifted, the time when the glue liquid can be lifted to 1cm-2cm without breaking is recorded as t1, the time when the glue liquid gathers into a ball in the center is recorded as t2, and the time when the glue liquid completely solidifies and is lifted is recorded as t3; Step four: according to the recorded time, the gel time and dynamic viscosity operable time of the sample are judged.

[0007] In step one, the epoxy resin is one or more mixtures of bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, and aliphatic epoxy resin.

[0008] In step one, the curing agent is one or more mixtures of polyamide, 4,4'-diamino diphenyl methane (MDA), diamino diphenyl methane (DDM), diethylene triamine (DETA), methyl hexahydrophthalic anhydride (HHPA), dicyanamide (Dicy), and 2-ethyl-4-methyl imidazole.

[0009] In step one, the accelerator is one or more mixtures of m-2,4,6-tris (dimethylaminomethyl) phenol, hydroquinone, o-cresol, N,N-dimethyl ethanolamine, benzyl dimethyl amine, acetyl acetone metal salt, and imidazole derivatives.

[0010] In step one, the solvent is one or more mixtures of toluene, cyclohexane, ethanol, acetone, butanone, tetrahydrofuran, N,N-dimethyl formamide, diethyl ether, and propylene glycol methyl ether.

[0011] In step three, the time difference of the recorded time t2-t1 is the operable time of the epoxy resin at low viscosity, and t3 is the gel time of the product.

[0012] The advantages of the present application are as follows: During the detection process, it has the advantages of low cost, simple operation and short time consumption, without the need to purchase rheometer and other equipment, or send the dynamic viscosity of the tested product to a third party organization for testing, thereby reducing the research and development cost of the enterprise. DETAILED DESCRIPTION

[0013] Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0014] Embodiment 1 A rapid detection method for dynamic viscosity operable time of epoxy resin, comprising the following steps: Step one: prepare epoxy resin adhesive, add 100 parts of bisphenol A type epoxy resin A, 80 parts of methyl hexahydrophthalic anhydride and 8 parts of hydroquinone into 100 parts of butanone, stir until completely dissolved; Step two: open the gel time tester, set the temperature to 171℃, and stabilize for 10 minutes; Step three: add 3 drops of prepared glue liquid in the middle of the hot plate, stir clockwise with toothpick at a speed of 2 circles per second, the solvent in the glue liquid volatilizes with time, the viscosity gradually increases, gently lift the toothpick during the period, record the time when the glue liquid can be lifted and pulled 1cm-2cm without breaking, record as 142s (t1), record the time when the glue liquid gathers into a ball in the center, record as 255s (t2), record the time when the glue liquid completely solidifies and is lifted, record as 348s (t3); Step four: judge the gel time and dynamic viscosity operable time of the sample according to the recorded time, as shown in Table 1 below.

[0015] Example 2 A rapid detection method for the dynamic viscosity operable time of epoxy resin, comprising the following steps: Step one: prepare epoxy resin adhesive, add 100 parts of bisphenol A type epoxy resin B, 80 parts of methyl hexahydrophthalic anhydride and 8 parts of hydroquinone into 100 parts of butanone, stir until completely dissolved; Step two: open the gel time tester, set the temperature to 171℃, and stabilize for 10 minutes; Step three: add 3 drops of prepared glue liquid in the middle of the hot plate, stir clockwise with toothpick at a speed of 2 circles per second, the solvent in the glue liquid volatilizes with time, the viscosity gradually increases, gently lift the toothpick during the period, record the time when the glue liquid can be lifted and pulled 1cm-2cm without breaking, record as 136s (t1), record the time when the glue liquid gathers into a ball in the center, record as 263s (t2), record the time when the glue liquid completely solidifies and is lifted, record as 351s (t3); Step four: judge the gel time and dynamic viscosity operable time of the sample according to the recorded time, as shown in Table 1 below.

[0016] Example 3 A rapid detection method for the dynamic viscosity operable time of epoxy resin, comprising the following steps: Step one: prepare epoxy resin adhesive, add 70 parts of bisphenol A type epoxy resin A and 30 parts of bisphenol F type epoxy resin C, 30 parts of diamino diphenyl methane and 5 parts of dimethyl imidazole into 100 parts of propylene glycol methyl ether, stir until completely dissolved; Step two: open the gel time tester, set the temperature to 171℃, and stabilize for 10 minutes; Step three: drop 3 drops of prepared glue in the middle of the hot plate, stir clockwise with toothpick at a speed of 2 circles per second, the solvent in the glue volatilizes over time, the viscosity gradually increases, gently pick up the toothpick during the period, record the time when the glue can be picked up and pulled 1-2 cm without breaking, record as 161 s (t1), record the time when the glue gathers into a ball in the center, record as 314 s (t2), record the time when the glue completely solidifies and is picked up, record as 421 s (t3); Step four: judge the gel time and dynamic viscosity operable time of the sample according to the recorded time, as shown in Table 1 below.

[0017] Example 4 A rapid detection method for the dynamic viscosity operable time of an epoxy resin, the specific steps of which are as follows: Step one: prepare an epoxy resin adhesive, add 30 parts of bisphenol A type epoxy resin A and 70 parts of bisphenol F type epoxy resin C, 30 parts of diamino diphenyl methane and 5 parts of dimethyl imidazole into 100 parts of propylene glycol methyl ether, and stir until completely dissolved; Step two: turn on the gel time tester, set the temperature to 171℃, and stabilize for 10 minutes; Step three: drop 3 drops of prepared glue in the middle of the hot plate, stir clockwise with toothpick at a speed of 2 circles per second, the solvent in the glue volatilizes over time, the viscosity gradually increases, gently pick up the toothpick during the period, record the time when the glue can be picked up and pulled 1-2 cm without breaking, record as 167 s (t1), record the time when the glue gathers into a ball in the center, record as 331 s (t2), record the time when the glue completely solidifies and is picked up, record as 432 s (t3); Step four: judge the gel time and dynamic viscosity operable time of the sample according to the recorded time, as shown in Table 1 below.

[0018] Table 1 Test results of samples in Example 1-Example 4 Sample [t1(s)] [t2(s)] [t3 (s)] [t2 - t1 (s)] Example 1 142 255 348 113 Example 2 136 263 351 127 Example 3 161 314 412 153 Example 4 167 331 432 164 As can be seen from Table 1: according to the comparison between Example 1 and Example 2, under the condition that the amount of curing agent and accelerator is the same and the gel time is similar, the operable time of bisphenol A type epoxy resin B (127 s) is longer than that of bisphenol A type epoxy resin A (113 s), and bisphenol A type epoxy resin B can be preferred when selecting epoxy resin products. In Example 3 and Example 4, the addition ratio of different epoxy resins can be changed to compare the length of gel time and operable time of the samples, and the addition amount of different epoxy resins can be better adjusted according to the test results to meet the needs.

[0019] The embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for rapid detection of the operable time of the dynamic viscosity of an epoxy resin, characterized in that: It comprises the following steps: Step one: preparation of epoxy resin adhesive, 100 parts of epoxy resin, 30-80 parts of curing agent and 0-10 parts of accelerator are added into 100 parts of solvent, stirring until completely dissolved; Step two: open the gel time tester, set the temperature to 171℃, and stabilize for 10 minutes; Step three: add 3 drops of prepared glue liquid in the middle of hot plate, stir clockwise with toothpick at a speed of 2 circles per second, the viscosity of glue liquid increases gradually with time, during which the toothpick is gently lifted, record the time when the glue liquid can be lifted and pulled 1cm-2cm without breaking, record as t1, record the time when the glue liquid gathers into a ball in the center, record as t2, record the time when the glue liquid completely solidifies and is lifted, record as t3; Step four: according to the recorded time, judge the gel time and dynamic viscosity of the sample.

2. The method for rapid detection of the time of epoxy resin dynamic viscosity operability according to claim 1, characterized in that: The epoxy resin in step one is bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin and aliphatic epoxy resin.

3. The method for rapid detection of the operable time of the dynamic viscosity of an epoxy resin according to claim 1, characterized in that: The curing agent in step one is one or more mixtures of polyamide, 4,4'-diamino diphenyl methane, diamino diphenyl methane, diethylene triamine, methyl hexahydrophthalic anhydride, dicyandiamide, 2-ethyl-4-methyl imidazole.

4. The method for rapid detection of the operable time of the dynamic viscosity of an epoxy resin according to claim 1, characterized in that: The accelerator in step one is one or more mixtures of m-2,4,6-tris (dimethylaminomethyl) phenol, hydroquinone, o-cresol, N, N-dimethyl ethanolamine, benzyl dimethyl amine, acetyl acetone metal salt and imidazole derivatives.

5. The method of claim 1, wherein the method is characterized by: The solvent in step one is one or more mixtures of toluene, cyclohexane, ethanol, acetone, butanone, tetrahydrofuran, N, N-dimethyl formamide, diethyl ether and propylene glycol methyl ether.

6. The method of claim 1, wherein the method is characterized by: The time difference t2-t1 recorded in step three is the operable time of epoxy resin at low viscosity, and t3 is the gel time of the product.