Epoxy resin curing agent for insulating castable and preparation method of epoxy resin curing agent

Abstract

The invention discloses an epoxy resin curing agent for an insulating castable and a preparation method of the epoxy resin curing agent. The epoxy resin curing agent is prepared from 50-90% of sulfonyl chloride substances and 10-50% of polyamine substances. The HCl generated in the reaction process is removed through a water washing method by using triethylamine with equal molar weight as an acid-binding agent. Performance detection shows that the product is high in mechanical strength, good in heat and humidity resistance and acid and alkali resistance and suitable for epoxy resin insulation pouring materials, and a very good technical effect is achieved.

Description

Technical Field

[0001] The invention relates to an epoxy resin curing agent, in particular to an epoxy resin curing agent for insulating casting material which cures at medium temperature and has high mechanical strength, good moisture and heat resistance and acid and alkali resistance, and a preparation method thereof, and belongs to the technical field of polymer materials. Background Art

[0002] Epoxy insulation casting material is a mixture of resin, curing agent, filler, etc. At the pouring temperature, the casting material has good fluidity and less volatiles, and the shrinkage rate is small after curing. The epoxy resin formed after the casting material is cured is an insulation product that integrates multiple functions such as insulation, moisture-proof, mildew-proof, anti-corrosion, fixation and isolation. Epoxy insulation casting material is widely used in the packaging of electronic and electrical devices, making the devices completely enclosed, reducing the impact of mechanical, thermal energy, natural environment, etc. on the equipment during use, and greatly extending the service life.

[0003] The selection of epoxy curing agent is a key factor affecting the performance of epoxy insulation casting materials. Acid anhydride curing agents have become the most commonly used curing agents in the field of insulation casting due to their long operating time, small shrinkage of the cured product, high heat deformation temperature, and excellent mechanical and electrical properties. This type of curing agent has two shortcomings: 1. It requires high-temperature curing at about 150°C, which may have adverse effects on some precision devices during the high-temperature curing process; 2. The curing agent contains an ester structure, so the acid and alkali resistance of the cured product is slightly poor.

[0004] The present invention performs sulfonylation modification on polyamine to obtain sulfonamide substances. The product contains a benzene ring structure, which ensures hardness and heat resistance after curing. At the same time, the sulfonamide bond has strong stability and is not easy to hydrolyze under acidic and alkaline conditions. Therefore, the epoxy resin and the sulfonamide curing agent have good acid and alkali resistance and moisture and heat resistance after curing. After the electronic components are encapsulated with the system, the equipment has better reliability and can be applied to relatively harsh environments. Summary of the invention

[0005] Purpose of the invention: The purpose of the present invention is to provide an epoxy resin curing agent for insulating casting material that has medium-temperature curing, high mechanical strength, good moisture and heat resistance, and good acid and alkali resistance in order to meet the packaging needs of electronic components; another purpose of the present invention is to provide a method for preparing the epoxy resin curing agent.

[0006] Technical solution: To achieve the above purpose, the technical solution adopted by the present invention is:

[0007] An epoxy resin curing agent for insulating casting material is prepared from the following raw materials in percentage by mass: 50-90% of sulfonyl chloride substances and 10-50% of polyamine substances. HCl generated in the sulfonylation process is removed by water washing using an equimolar amount of triethylamine as an acid binding agent.

[0008] As a preferred embodiment, the epoxy resin curing agent for the insulating casting material described above, the sulfonyl chloride substance is one or a mixture of benzenesulfonyl chloride, p-toluenesulfonyl chloride, indane-5-sulfonyl chloride, pyrimidine-2-sulfonyl chloride, 2-phenyl-ethanesulfonyl chloride, 2-phenylmethylsulfonyl chloride, 1-ethylsulfonyl chloride, butanesulfonyl chloride, pentanesulfonyl chloride.

[0009] As a preferred embodiment, the epoxy resin curing agent for the insulating casting material described above, the polyamine substance is one or a mixture of several of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, pentamethylenediamine, hexamethylenediamine, 2-methylpentamethylenediamine, isophoronediamine, 1,3-cyclohexyldimethylamine, meta-xylylenediamine, cyclohexyldiamine, cyclopentamethylenediamine, diaminodicyclohexylmethane, and diaminodiphenylmethane.

[0010] As a preferred embodiment, the epoxy resin curing agent for the insulating casting material described above uses at least one of the sulfonyl chloride substance and the polyamine substance containing a benzene ring structure, and the molar ratio of the sulfonyl chloride substance to the polyamine substance is (1-2):1.

[0011] The method for preparing the epoxy resin curing agent for insulating casting material of the present invention comprises the following steps:

[0012] (1) Add the measured polyamines and triethylamine into a reactor, stir to mix the materials evenly, and maintain the material temperature at 25-30° C.;

[0013] (2) adding the measured sulfonyl chloride substances into the reactor in batches, during which the temperature is controlled at 25-30° C.;

[0014] (3) After the sulfonyl chloride is added, the temperature is maintained at 25-30°C for 2 hours;

[0015] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0016] (5) separating the liquids and removing the aqueous layer;

[0017] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0018] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0019] The present invention mainly improves the deficiencies of the prior art through the following solutions:

[0020] 1. The product of the present invention belongs to an amine curing agent. After being modified by sulfonylation to adjust the activity, it has a long operating time at room temperature, can be cured at medium temperature, and has a small heat release during the curing process.

[0021] 2. The present invention uses sulfonyl chloride with a benzene ring structure or a polyamine with a benzene ring structure as a raw material to ensure that the finished product contains a benzene ring structure and has good mechanical strength after curing.

[0022] 3. The present invention utilizes the strong bond energy of sulfonamide to make the product not easy to hydrolyze under acidic or alkaline conditions, and the solidified material has high stability.

[0023] 4. The present invention can achieve diversity in product molecular structure through raw material selection and feed ratio, thereby designing products suitable for different usage requirements.

[0024] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0025] The present invention designs a novel epoxy curing agent, which performs sulfonylation modification on polyamines and has the following advantages: 1. It has moderate activity, a long operating time at room temperature, and can be cured at medium temperature. Compared with the high-temperature curing of about 150°C of acid anhydrides, it saves energy and avoids high-temperature impact during component packaging, so it is suitable for precision device packaging; 2. The product of the present invention does not contain easily hydrolyzable groups, and utilizes the strong bond energy of sulfonamide. The product is not easy to hydrolyze under acidic or alkaline conditions, and the cured product has high stability. The encapsulated equipment is suitable for more stringent environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the reaction equation of the present invention. DETAILED DESCRIPTION

[0027] Example 1

[0028] 1. An epoxy resin curing agent for insulating casting material, which is made of the following raw materials in percentage by mass: 76% of p-toluenesulfonyl chloride and 24% of ethylenediamine (the molar ratio of p-toluenesulfonyl chloride to ethylenediamine is 1:1).

[0029] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0030] (1) Add 60 g of ethylenediamine and 101 g of triethylamine into a reactor, stir to mix the materials evenly, and maintain the material temperature at 25-30° C.;

[0031] (2) 190 g of p-toluenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0032] (3) After the addition of p-toluenesulfonyl chloride is completed, the temperature is maintained at 25-30° C. for 2 hours;

[0033] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0034] (5) separating the liquids and removing the aqueous layer;

[0035] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0036] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0037] Example 2

[0038] 1. An epoxy resin curing agent for insulating casting material is made of the following raw materials in percentage by mass: 83% of p-toluenesulfonyl chloride and 17% of ethylenediamine (the molar ratio of p-toluenesulfonyl chloride to ethylenediamine is 1.5:1).

[0039] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0040] (1) Add 60 g of ethylenediamine and 152 g of triethylamine into a reactor, stir to mix the materials evenly, and maintain the material temperature at 25-30° C.;

[0041] (2) 285 g of p-toluenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0042] (3) After the addition of p-toluenesulfonyl chloride is completed, the temperature is maintained at 25-30° C. for 2 hours;

[0043] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0044] (5) separating the liquids and removing the aqueous layer;

[0045] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0046] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0047] Example 3

[0048] 1. An epoxy resin curing agent for insulating casting material is made of the following raw materials in percentage by mass: 86% of p-toluenesulfonyl chloride and 14% of ethylenediamine (the molar ratio of p-toluenesulfonyl chloride to ethylenediamine is 2:1).

[0049] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0050] (1) Add 60 g of ethylenediamine and 202 g of triethylamine into a reactor, stir to mix the materials evenly, and maintain the material temperature at 25-30° C.;

[0051] (2) 380 g of p-toluenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0052] (3) After the addition of p-toluenesulfonyl chloride is completed, the temperature is maintained at 25-30° C. for 2 hours;

[0053] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0054] (5) separating the liquids and removing the aqueous layer;

[0055] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0056] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0057] Example 4

[0058] 1. An epoxy resin curing agent for insulating casting material, which is made of the following raw materials in percentage by mass: 66% of p-toluenesulfonyl chloride and 34% of diaminodiphenylmethane (the molar ratio of p-toluenesulfonyl chloride to diaminodiphenylmethane is 2:1).

[0059] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0060] (1) 198 g of diaminodiphenylmethane and 202 g of triethylamine were added to a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.;

[0061] (2) 380 g of p-toluenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0062] (3) After the addition of p-toluenesulfonyl chloride is completed, the temperature is maintained at 25-30° C. for 2 hours;

[0063] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0064] (5) separating the liquids and removing the aqueous layer;

[0065] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0066] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0067] Example 5

[0068] 1. An epoxy resin curing agent for insulating casting material, which is made of the following raw materials in percentage by mass: 61% of butanesulfonyl chloride and 39% of diaminodiphenylmethane (the molar ratio of butanesulfonyl chloride to diaminodiphenylmethane is 2:1).

[0069] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0070] (1) 198 g of diaminodiphenylmethane and 202 g of triethylamine were added to a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.;

[0071] (2) 312 g of butanesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0072] (3) After the butanesulfonyl chloride is added, the temperature is maintained at 25-30° C. for 2 hours;

[0073] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0074] (5) separating the liquids and removing the aqueous layer;

[0075] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0076] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0077] Example 6

[0078] 1. An epoxy resin curing agent for insulating casting material is made of the following raw materials in percentage by mass: 70% of butanesulfonyl chloride and 30% of m-phenylenediamine (the molar ratio of butanesulfonyl chloride to m-phenylenediamine is 2:1).

[0079] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0080] (1) 136 g of m-phenylenediamine and 202 g of triethylamine were added to a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.;

[0081] (2) 312 g of butanesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0082] (3) After the butanesulfonyl chloride is added, the temperature is maintained at 25-30° C. for 2 hours;

[0083] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0084] (5) separating the liquids and removing the aqueous layer;

[0085] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0086] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0087] Example 7

[0088] 1. An epoxy resin curing agent for insulating casting material is made of the following raw materials in percentage by mass: 71% of benzenesulfonyl chloride and 29% of triethylenetetramine (the molar ratio of benzenesulfonyl chloride to triethylenetetramine is 2:1).

[0089] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0090] (1) 146 g of triethylenetetramine and 202 g of triethylamine were added into a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.;

[0091] (2) 353 g of benzenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0092] (3) After the benzenesulfonyl chloride is added, the temperature is maintained at 25-30°C for 2 hours;

[0093] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0094] (5) separating the liquids and removing the aqueous layer;

[0095] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0096] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0097] Example 8

[0098] 1. An epoxy resin curing agent for insulating casting material is made of the following raw materials in percentage by mass: 63% of benzenesulfonyl chloride and 37% of diaminodicyclohexylmethane (the molar ratio of benzenesulfonyl chloride to diaminodicyclohexylmethane is 2:1).

[0099] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0100] (1) 210 g of diaminodicyclohexylmethane and 202 g of triethylamine were added to a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.;

[0101] (2) 353 g of benzenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0102] (3) After the benzenesulfonyl chloride is added, the temperature is maintained at 25-30°C for 2 hours;

[0103] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0104] (5) separating the liquids and removing the aqueous layer;

[0105] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0106] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0107] Example 9 Comparative Example

[0108] 1. A sulfonamide epoxy resin curing agent, which is made of the following raw materials in percentage by mass: 84% of butanesulfonyl chloride and 16% of ethylenediamine (the molar ratio of butanesulfonyl chloride to ethylenediamine is 2:1).

[0109] 2. A method for preparing an epoxy resin curing agent for insulating casting material, comprising the following steps:

[0110] (1) Add 60 g of ethylenediamine and 202 g of triethylamine into a reactor, stir to mix the materials evenly, and maintain the material temperature at 25-30° C.;

[0111] (2) 312 g of butanesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.;

[0112] (3) After the butanesulfonyl chloride is added, the temperature is maintained at 25-30° C. for 2 hours;

[0113] (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers;

[0114] (5) separating the liquids and removing the aqueous layer;

[0115] (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor;

[0116] (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

[0117] Example 10 Performance Test

[0118] Epoxy resin (828 produced by Jiangsu Sanmu Chemical Co., Ltd.) was mixed evenly with the epoxy resin curing agent prepared above, and evenly coated on the tinplate to form a film with a film thickness of 40 μm. The basic properties of the finished product after curing were measured as shown in the following table.

[0119]

[0120] The above performance test results show that, as can be seen from the above examples, different sulfonyl chloride and polyamine selection and feed ratio adjustment can be used to design curing agents with different performances. The test results of Examples 1-3 show that increasing the amount of sulfonyl chloride significantly prolongs the operable time, and the moisture and heat resistance and acid and alkali resistance are also significantly improved. The test results of Example 9 show that if the product does not contain benzene rings, the moisture and heat resistance and acid and alkali resistance are not greatly affected, but the hardness of the cured product is significantly reduced. For the insulation casting application field, the protection performance of electronic components is not enough.

[0121] In comparison, the epoxy resin curing agent prepared in Example 4 of the present invention has a long operating time, is not easily hydrolyzed under acidic or alkaline conditions, has high stability and hardness of the cured product, and the encapsulated equipment is suitable for more stringent environments, achieving good technical results.

[0122] In general, the epoxy resin curing agent product prepared by the present invention has high mechanical strength, good moisture and heat resistance and acid and alkali resistance, is suitable for epoxy resin insulating casting materials, and has achieved very good technical effects.

[0123] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An epoxy resin curing agent for insulating casting material, characterized in that: The invention is prepared from the following raw materials in the following mass percentages: 50-90% of sulfonyl chloride substances and 10-50% of polyamine substances.

2. The epoxy resin curing agent for insulating casting material according to claim 1, characterized in that: The sulfonyl chloride substance is one or a mixture of benzenesulfonyl chloride, p-toluenesulfonyl chloride, indane-5-sulfonyl chloride, pyrimidine-2-sulfonyl chloride, 2-phenyl-ethanesulfonyl chloride, 2-phenylmethylsulfonyl chloride, 1-ethylsulfonyl chloride, butanesulfonyl chloride, and pentanesulfonyl chloride.

3. The epoxy resin curing agent for insulating casting material according to claim 1, characterized in that: The polyamine substance is one or a mixture of ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, pentanediamine, hexanediamine, 2-methylpentanediamine, isophoronediamine, 1,3-cyclohexanedimethylamine, meta-xylylenediamine, cyclohexanediamine, cyclopentanediamine, diaminodicyclohexylmethane, and diaminodiphenylmethane.

4. The epoxy resin curing agent for insulating casting material according to claim 1, characterized in that: When sulfonyl chloride and polyamine are used in combination, at least one of the raw materials contains a benzene ring structure.

5. The epoxy resin curing agent for insulating casting material according to claim 1, characterized in that: The molar ratio of the sulfonyl chloride substance to the polyamine substance is (1-2):

1.

6. The method for preparing the epoxy resin curing agent for insulating casting material according to any one of claims 1 to 5, characterized in that: The following steps are involved: (1) Add the measured polyamines and triethylamine into a reactor, stir to mix the materials evenly, and maintain the material temperature at 25-30° C.; (2) adding the measured sulfonyl chloride substances into the reactor in batches, during which the temperature is controlled at 25-30° C.; (3) After the sulfonyl chloride is added, the temperature is maintained at 25 to 30° C. for 1 to 2 hours; (4) Add measured water, continue stirring for 10 to 30 minutes, and then let stand to separate into layers; (5) separating the liquids and removing the aqueous layer; (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor; (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

7. An epoxy resin curing agent for insulating casting material, characterized in that: It includes the following steps: (1) 198 g of diaminodiphenylmethane and 202 g of triethylamine were added to a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.; (2) 380 g of p-toluenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.; (3) After the addition of p-toluenesulfonyl chloride is completed, the temperature is maintained at 25-30° C. for 2 hours; (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers; (5) separating the liquids and removing the aqueous layer; (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor; (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

8. A method for preparing an epoxy resin curing agent for insulating casting material, characterized in that: It includes the following steps: (1) 198 g of diaminodiphenylmethane and 202 g of triethylamine were added to a reactor and stirred to mix the materials evenly while maintaining the material temperature at 25-30° C.; (2) 380 g of p-toluenesulfonyl chloride was added to the reactor in batches, and the temperature was controlled at 25-30° C.; (3) After the addition of p-toluenesulfonyl chloride is completed, the temperature is maintained at 25-30° C. for 2 hours; (4) Add measured water, continue stirring for 10 minutes and then let stand to separate into layers; (5) separating the liquids and removing the aqueous layer; (6) Turn on the vacuum and slowly raise the temperature to 60-70°C to remove a small amount of water in the reactor; (7) After the water is removed, the mixture is cooled to below 40°C, filtered and discharged to obtain the finished product.

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