Construction strategy and preparation method of epoxy resin with high phosphorus content

Abstract

The invention relates to a construction strategy and a preparation method of epoxy resin with high phosphorus content, and belongs to the technical field of preparation of halogen-free flame-retardant high polymer materials. According to the material, basic epoxy resin and a reaction type phosphorus-containing flame retardant diphenylphosphine oxide (DPO) and derivatives thereof are used as basic raw materials, and the high-phosphorus-content epoxy resin is obtained through a one-step reaction. According to the preparation method, the phosphorus content and molecular weight of the product are effectively controlled through formula design, the phosphorus-containing epoxy resin with high phosphorus content and high flame retardance can be prepared through a simple one-step method, and the phosphorus-containing epoxy resin can be applied to the fields of pipe coiling, winding and the like and has good flame retardance, heat stability and processability.

Description

Technical Field

[0001] The present application relates to the technical field of preparation of halogen-free flame-retardant polymer materials, and in particular to a construction strategy and preparation method of a high-phosphorus content epoxy resin. Background Art

[0002] As a general-purpose thermosetting resin, epoxy resin has good heat resistance, chemical resistance and excellent mechanical properties. It is widely used in the electronic industry such as semiconductor packaging and electrical insulation materials. However, the limiting oxygen index (LOI) of epoxy resin material is only about 20%, which is easy to burn and cause fire, which limits its application to a certain extent. Traditional halogen-based flame-retardant epoxy resins produce a large number of toxic and corrosive products during use, which can no longer meet the society's growing environmental protection requirements. The research and application development of halogen-free flame-retardant epoxy resins has become a new research direction, among which low-smoke and low-toxic phosphorus-based flame retardant systems have become a research hotspot due to their high flame retardant efficiency. At present, phosphorus-containing flame-retardant epoxy resins are mostly prepared by reacting 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and its derivatives with basic epoxy resins. The phosphorus content of the resin is low, and a large amount of addition is often required to achieve the required flame retardant grade, which in turn affects other properties of the resin and limits its application. The reactive flame retardant diphenylphosphine oxide (DPO) and its derivatives can provide a higher phosphorus content with a smaller addition amount, which is of great significance for constructing flame-retardant epoxy resins with high phosphorus content. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a construction strategy and a preparation method of a high-phosphorus content epoxy resin.

[0004] In order to solve the above technical problems, the technical solution of the present invention is: a high-phosphorus epoxy resin, the innovation of which is to use a basic epoxy resin and a reactive phosphorus-containing flame retardant diphenylphosphine oxide (DPO) and its derivatives as basic raw materials, and obtain the high-phosphorus epoxy resin through a one-step reaction. The method achieves effective control of the phosphorus content and molecular weight of the product through formula design, and can produce a phosphorus-containing epoxy resin with a high phosphorus content and high flame retardancy through a simple one-step method.

[0005] Furthermore, the high phosphorus content epoxy resin has a softening point of 50±20° C., an epoxy equivalent of 350±70 g / eq, a phosphorus content of 4.5±1%, and has the following structure:

[0006]

[0007] In the formula, R1 is any one of —CH2— and —C(CH3)2—.

[0008] Where R2 is Any of .

[0009]

[0010] Where R3 is Any of .

[0011] A method for preparing a high-phosphorus content epoxy resin, the innovation of which is that it comprises the following steps:

[0012] S1: 60-80 parts by weight of base epoxy resin and 20-40 parts by weight of reactive phosphorus-containing flame retardant are placed in a reactor and heated to 90°C to dissolve and become transparent;

[0013] S2: Raise the temperature to 120-140°C and continue adding 0.02 parts by mass of catalyst into the reactor;

[0014] S3: Continue to raise the temperature to 160-180°C and react for 4-6 hours to obtain a high-phosphorus epoxy resin with a softening point of 50±20°C, an epoxy equivalent of 350±70g / eq, and a phosphorus content of 4.5±1%.

[0015] Furthermore, the basic epoxy resin in S1 is one or two of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol A novolac epoxy resin, phenol novolac epoxy resin, and o-cresol novolac epoxy resin.

[0016] Furthermore, the reactive phosphorus-containing flame retardant in S1 is one or both of diphenylphosphine oxide (DPO) and 2,5-dihydroxyphenyl (diphenyl)phosphine oxide (DPOHQ).

[0017] Furthermore, the catalyst in S2 is one or two of triphenylphosphine, ethyltriphenylphosphine bromide, ethyltriphenylphosphine acetate, triethylbenzylammonium chloride, and tetrabutylammonium bromide.

[0018] The advantages of the present invention are that the high-phosphorus-content epoxy resin of the present invention can effectively control the phosphorus content and molecular weight of the product through formula design, and can prepare the phosphorus-containing epoxy resin with high phosphorus content, good flame retardancy, thermal stability and processability through a simple one-step method.

[0019] After being cured with cyanate ester, the high-phosphorus epoxy resin prepared by the product of the present invention has flame retardancy that passes UL94-V0 grade and reaches a limiting oxygen index of 42.3%, meeting performance requirements in the fields of tube winding and winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Flow chart for the preparation of high phosphorus content epoxy resin. DETAILED DESCRIPTION

[0021] The high-phosphorus epoxy resin of the invention uses a basic epoxy resin and a reactive phosphorus-containing flame retardant diphenylphosphine oxide (DPO) and its derivatives as basic raw materials, and is obtained by a one-step reaction under the action of a catalyst.

[0022] The preparation method of the above-mentioned high phosphorus content epoxy resin comprises the following steps:

[0023] S1: 60-80 parts by weight of base epoxy resin and 20-40 parts by weight of reactive phosphorus-containing flame retardant are placed in a reactor and heated to 90°C to dissolve and become transparent;

[0024] S2: Raise the temperature to 120-140°C and continue adding 0.02 parts by mass of catalyst into the reactor;

[0025] S3: Continue to raise the temperature to 160-180°C and react for 4-6 hours to obtain a high-phosphorus epoxy resin with a softening point of 40±10°C, an epoxy equivalent of 350±70g / eq, and a phosphorus content of 4.5±1%.

[0026] Furthermore, the basic epoxy resin in S1 is one or two of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol A novolac epoxy resin, phenol novolac epoxy resin, and o-cresol novolac epoxy resin.

[0027] Furthermore, the reactive phosphorus-containing flame retardant in S1 is one or both of diphenylphosphine oxide (DPO) and 2,5-dihydroxyphenyl (diphenyl)phosphine oxide (DPOHQ).

[0028] Furthermore, the catalyst in S2 is one or two of triphenylphosphine, ethyltriphenylphosphine bromide, ethyltriphenylphosphine acetate, triethylbenzylammonium chloride, and tetrabutylammonium bromide.

[0029] The prepared high-phosphorus content epoxy resin has a softening point of 50±20° C., an epoxy equivalent of 350±70 g / eq, a phosphorus content of 4.5±1%, and is a yellow-brown transparent solid.

[0030] Example 1

[0031] 74 parts by mass of bisphenol F diglycidyl ether (Shandong Aimonte EMTE170) and 26 parts by mass of diphenylphosphine oxide (DPO) were added into a reactor, heated to 90°C to dissolve, then heated to 120°C, 0.02 parts by mass of ethyl triphenylphosphine acetate was added, and then heated to 180°C and kept warm for 4 hours. The obtained low-softening-point phosphorus-containing epoxy resin had a softening point of 38.3°C, an epoxy equivalent of 302.5 g / eq, a phosphorus content of 4.0%, and was a yellow-brown transparent solid.

[0032] Example 2

[0033] 56.6 parts by mass of bisphenol F diglycidyl ether (Shandong Aimonte EMTE160), 10.8 parts by mass of bisphenol A diglycidyl ether (Shandong Aimonte EMTE128), and 32.6 parts by mass of diphenylphosphine oxide (DPO) were added into a reactor, heated to 90°C to dissolve, then heated to 140°C, 0.02 parts by mass of ethyl triphenylphosphine acetate was added, and then heated to 160°C, and kept warm for 5 hours to react; the obtained low-softening-point phosphorus-containing epoxy resin had a softening point of 48.4°C, an epoxy equivalent of 405.9 g / eq, a phosphorus content of 5.0%, and was a yellow-brown transparent solid.

[0034] Example 3

[0035] 42.3 parts by mass of bisphenol F diglycidyl ether (Shandong Aimonte EMTE170), 28.2 parts by mass of bisphenol A diglycidyl ether (Shandong Aimonte EMTE128), 20 parts by mass of diphenylphosphine oxide (DPO), and 9.5 parts by mass of 2,5-dihydroxyphenyl (diphenyl)phosphine oxide (DPOHQ) were added into a reactor, heated to 90°C to dissolve, then heated to 120°C, 0.02 parts by mass of ethyl triphenylphosphine acetate was added, and then heated to 170°C and kept warm for reaction for 5 hours; the obtained low softening point phosphorus-containing epoxy resin had a softening point of 50.3°C, an epoxy equivalent of 390.6 g / eq, a phosphorus content of 4.0%, and was a yellow-brown transparent solid.

[0036] Example 4

[0037] 14.7 parts by mass of bisphenol F diglycidyl ether (Shandong Aimonte EMTE170), 55.8 parts by mass of phenol novolac epoxy resin (Shandong Aimonte EMTE638), 20 parts by mass of diphenylphosphine oxide (DPO), and 9.5 parts by mass of 2,5-dihydroxyphenyl (diphenyl) phosphine oxide (DPOHQ) were added into a reactor, the temperature was raised to 90°C to dissolve, the temperature was continued to be raised to 120°C, 0.01 parts by mass of triethylbenzylammonium chloride was added, the temperature was raised to 140°C, 0.01 parts by mass of tetrabutylammonium bromide was continued to be added, the temperature was raised to 168°C, and the reaction was kept warm for 5 hours; the obtained low softening point phosphorus-containing epoxy resin had a softening point of 68.5°C, an epoxy equivalent of 392.8 g / eq, a phosphorus content of 4.0%, and was a yellow-brown transparent solid.

[0038] Finally, it should be noted that the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and improvements, and these changes and improvements shall all fall within the scope of the present invention claimed for protection.

Claims

1. A high phosphorus content epoxy resin, characterized in that The phosphorus-containing epoxy resin is based on a basic epoxy resin, a reactive phosphorus-containing flame retardant diphenylphosphine oxide and its derivatives as raw materials, and a high-phosphorus-containing epoxy resin is obtained by a one-step reaction. The phosphorus-containing epoxy resin has the following structure: In the formula, R1 is any one of —CH2— and —C(CH3)2—. Where R2 is Any of . Where R3 is Any of .

2. The high phosphorus content epoxy resin according to claim 1, characterized in that: The phosphorus-containing epoxy resin has a softening point of 50±20° C., an epoxy equivalent of 350±70 g / eq, and a phosphorus content of 4.5±1%.

3. A method for preparing a high phosphorus content epoxy resin, characterized in that: The following steps are involved: S1: 60-80 parts by weight of base epoxy resin and 20-40 parts by weight of reactive phosphorus-containing flame retardant are placed in a reactor and heated to 90°C to dissolve and become transparent; S2: Raise the temperature to 120-140°C and continue adding 0.02 parts by mass of catalyst into the reactor; S3: Continue to raise the temperature to 160-180°C and react for 4-6 hours to obtain a high-phosphorus epoxy resin with a softening point of 40±10°C, an epoxy equivalent of 350±70g / eq, and a phosphorus content of 4.5±1%.

4. The method for preparing a high phosphorus content epoxy resin according to claim 3, characterized in that: The basic epoxy resin in S1 is one or two of bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol A novolac epoxy resin, phenol novolac epoxy resin, and o-cresol novolac epoxy resin.

5. The method for preparing a high phosphorus content epoxy resin according to claim 3, characterized in that: The reactive phosphorus-containing flame retardant in S1 is one or both of diphenylphosphine oxide (DPO) and 2,5-dihydroxyphenyl (diphenyl)phosphine oxide (DPOHQ).

6. The method for preparing a high phosphorus content epoxy resin according to claim 3, characterized in that: The catalyst in S2 is one or two of triphenylphosphine, ethyltriphenylphosphine bromide, ethyltriphenylphosphine acetate, triethylbenzylammonium chloride, and tetrabutylammonium bromide.

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