KR100548922B1 - Bisphenol-s epoxy resin and preparation thereof - Google Patents

Abstract

The present invention relates to a bisphenol-S epoxy resin of Formula 1 and a method for preparing the same, wherein bisphenol-S type epoxy resin obtained by reacting bisphenol-S and epichlorohydrin in the presence of a base catalyst according to the present invention has excellent physical properties. It is possible to replace the existing bisphenol-A and bisphenol-F type epoxy resin to implement a matrix with excellent performance.

Description

Bisphenol-S epoxy resin and its manufacturing method {BISPHENOL-S EPOXY RESIN AND PREPARATION THEREOF}             

1 is a graph showing a curing exotherm curve when the bisphenol-S epoxy resin according to the present invention is cured using diaminodiphenylmethane (DDM),

2 is a graph showing a curing exotherm curve when the bisphenol-S epoxy resin according to the present invention is cured using phthalic anhydride (PA) or terephthalic anhydride (THPA).

The present invention relates to a bisphenol-S type epoxy resin and a method for preparing the same, and more particularly, to an epoxy resin having excellent physical properties prepared by using bisphenol-S having a sulfone group and epichlorohydrin as a starting material and its It relates to a manufacturing method.

Existing bisphenol-type epoxy resins are mainly bisphenol-A epoxy resins (DGEBA) and bisphenol-F epoxy resins (diglycidyl ether of bisphenol-F, DGEBF) Two types of) are commercially manufactured and widely used in a wide range of applications.

However, these two resins, DGEBA and DGEBF, have been limited in their use as high-performance structural materials due to their low thermal stability at high temperatures. Therefore, in recent years, the development of a resin having a new physical property that improves these disadvantages is urgently needed, and attention is being drawn to improving the physical properties of the resin by introducing other functional groups in the main chain.

Accordingly, an object of the present invention is to provide a new epoxy resin having better physical properties than existing bisphenol-A and bisphenol-F type epoxy resins.

In order to achieve the above object, the present invention provides a bisphenol-S type epoxy resin of the following general formula (1):

Formula 1

The present invention also provides a process for preparing a bisphenol-S type epoxy resin of formula (1) comprising reacting bisphenol-S of formula (4) with epichlorohydrin of formula (5) in the presence of a base catalyst:

Hereinafter, the present invention will be described in more detail.

According to the present invention, bisphenol-S of formula (4) and epichlorohydrin of formula (5) are reacted in the presence of a base catalyst as shown in Scheme 1 below to form a semi-solid resin containing a sulfone group in the main chain, S type epoxy resin is prepared.

In the method according to the present invention, the use of bisphenol-S having a purity of 98% or more is effective in increasing the production yield and finally in achieving the purity and expected physical properties of the produced resin.

Bisphenol-S and epichlorohydrin used as starting materials, and a catalyst are suitably used in a molar ratio in the range of 1 mol: 3-5 mol: 0.5-1 mol.

In this method, the temperature is in the range of 90 to 140 ° C., which is suitable for minimizing by-product generation, minimizing epichlorohydrin loss, and molecular weight control. NaOH may be preferably used as the catalyst, and the NaOH used as the catalyst may have a concentration of 30 to 45%, which is suitable for discoloration of production resin, minimization of by-product formation, and reaction rate. When the manufacturing process temperature is lower than 90 ° C or the NaOH concentration is 30% or less, the reaction is slow and the water removal and stirring are difficult to obtain the desired resin, and when the manufacturing process temperature is 140 ° C or higher or the NaOH concentration is 45% or higher The reaction can be obtained in a short time to obtain a high molecular weight product, but the degree of crosslinking is rapidly increased to produce a resin close to a solid phase, which is very disadvantageous for molding.

The reaction time of the process may be performed in the range of 6 to 10 hours.

The bisphenol-S type epoxy resin prepared according to the method of the present invention has a molecular weight in the range of about 1,000 to 3,000, and a matrix resin having a glass transition temperature of 75 to 100 ° C. by curing it with a conventional curing agent such as an amine or an acid anhydride curing agent. Can be implemented.

The bisphenol-S epoxy resin according to the present invention is excellent in flame retardancy and comparable to or superior to conventional bisphenol A or bisphenol F resins in other physical properties.

Hereinafter, the present invention will be described in more detail based on the following examples. However, the following examples are not intended to limit the invention only.

Synthesis Example 1

200.2 g of bisphenol-S (0.8 mol, purity 99.8%, Korea Fine Chemicals Co., Ltd., melting point 245 ° C), 370.1 g of epichlorohydrin (4 mol, Aldrich Chem Co.), and 80 g (0.8 mol of 40% NaOH aqueous solution) ) Was added to a reactor equipped with a stirrer, a thermometer, and a condenser, and reacted for 7 hours while maintaining the temperature at 100 ° C to prepare a bisphenol-S type epoxy resin.

In order to remove excess epichlorohydrin and water present in the resin prepared after the reaction, it was dried in a vacuum oven at 110 ° C. and 80 kPa for 2 hours, and isobutyl methyl ketone (MIBK) was used for the purpose of removing reaction byproducts and impurities. It was dissolved in) and stirred for 30 minutes and then filtered. The filtered bisphenol-S type epoxy resin was vacuum distilled at 100 ° C. to remove MIBK to obtain a bisphenol-S type epoxy resin having a yield of 80% or more and a molecular weight of 2093.

Synthesis Example 2

In the same manner as in Synthesis Example 1, the reaction was carried out for 8 hours while maintaining the reaction temperature at 120 ° C to finally obtain a bisphenol-S type epoxy resin having a yield of 80% or more and a molecular weight of 2472.

Test Example 1

Diaminodiphenylmethane (DDM) was added to a bisphenol-S type epoxy resin obtained in Synthesis Example 1 in a weight ratio of 100: 30, and the resulting mixture was cured to prepare a specimen. The curing conditions were 1 hour at 80 ° C, 3 hours at 120 ° C, and 2 hours at 150 ° C. Exothermic curve at the time of curing is shown in FIG.

For this specimen, the cross-head speed was 1 mm / min using the Universal Test Machine # 1125, and the span-to-depth ratio between the support and the thickness of the specimen was 4: 1. The fracture toughness of each composition was measured as a critical stress intensity factor (K _IC ), and the tensile strength was measured by fixing the cross-head speed at 5 mm / min. The critical stress factor value was 2.5 MPa. M ^1/2 and tensile strength were obtained to 37 MPa.

Test Example 2

A phthalic anhydride (PA) as an acid anhydride curing agent was added to a bisphenol-S type epoxy resin obtained in Synthesis Example 1 at a weight ratio of 100: 30, and cured at 150 ° C. for 2 hours at 180 ° C. for 6 hours to prepare a specimen. The glass transition temperature (T _g ) of the specimen thus prepared was 75 ° C. Exothermic curve at the time of curing is shown in FIG.

Test Example 3

Terephthalic anhydride (THPA), an acid anhydride curing agent, was added to the bisphenol-S type epoxy resin obtained in Synthesis Example 1 at a weight ratio of 100: 30 to prepare a specimen under the same curing conditions as in Example 2. The glass transition temperature (T _g ) of the specimen thus prepared was 80 ° C.

Exothermic curve at the time of curing is shown in FIG.

Test Example 4

To the bisphenol-S type epoxy resin obtained in Synthesis Example 2, diaminodiphenylmethane (DDM) was added as a curing agent in a 1: 1 equivalent ratio to prepare a specimen.

The fracture toughness of each composition was determined by fixing the cross-head speed at 1 mm / min and the span to depth at 4: 1 using the Universal Test Machine # 1125 on the specimens thus fabricated. Measured as stress intensity factor (K _IC ), and tensile strength was measured by fixing cross-head speed at 5mm / min.The critical stress intensity factor value was 3.8MPa · m ^1/2 , and tensile strength was 34.5 MPa was obtained.

Test Example 5

The bisphenol-S type epoxy resin obtained in Synthesis Example 2 was prepared under the same curing conditions as in Example 2 to obtain a cured product having a glass transition temperature (T _g ) of 78 ° C.

Test Example 6

A bisphenol-S type epoxy resin obtained in Synthesis Example 2 was prepared under the same curing conditions as in Example 3 to obtain a cured product having a glass transition temperature (T _g ) of 86 ° C.

Comparative test example

Existing bisphenol A and F resins were cured under the same conditions as in Test Example 1, and then the specimens were prepared, and then the critical stress intensity factor (K _IC ) and tensile strength were evaluated.

TABLE 1

division K _IC (MPam ^1/2 ) Tensile Strength (MPa) Bisphenol A 2.6 32 Bisphenol F 2.1 29 Bisphenol S (Synthesis Example 1) 3.2 39 Bisphenol S (Synthesis Example 2) 3.8 35

The bisphenol-S type epoxy resin prepared according to the present invention is semi-solid with a glass transition temperature of about 75 to 100 ° C. and has superior or equivalent physical properties to conventional bisphenol-A or bisphenol-F type epoxy resins. It can be used as a substitute.

Claims (9)

Bisphenol-S type epoxy resin of formula (I): Formula 1

1: Temperature of the bisphenol-S of the following formula (4) and epichlorohydrin of the following formula (5) in a molar ratio of 1: 3 to 5 in the presence of 0.5 to 1 molar base catalyst relative to the moles of bisphenol-S A process for preparing a bisphenol-S type epoxy resin of formula 1 according to claim 1 comprising reacting for 6 to 10 hours in Formula 4

Formula 5

delete delete The method of claim 2, Wherein the catalyst is NaOH at a concentration of 30 to 45%. delete delete A matrix resin composition comprising the epoxy resin according to claim 1. The method of claim 8, A product characterized in that the glass transition temperature of the epoxy resin is 75 to 100 ℃.

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