KR100901854B1 - Low Temperature curable Thermosetting Epoxy Resin Composition and Manufacturing method thereof - Google Patents

Abstract

In the thermosetting epoxy resin composition according to the present invention, a polythiol resin is added to a mixture of (a) a bisphenol F type epoxy resin and a bisphenol A type epoxy resin in an amount of 5 to 20% by weight based on the total weight of the mixture. Preparing a modified epoxy resin; (b) 2 to 5% by weight of adhesion promoter, 20 to 50% by weight of filler, 10 to 30% by weight of curing agent, and 1 to 3% by weight of latent curing catalyst are dispersed in the modified epoxy resin. It is prepared through; step.

Modified epoxy resin, moisture resistance, crack resistance, impact resistance

Description

Low Temperature Curable Thermosetting Epoxy Resin Composition and Manufacturing Method Thereof {Low Temperature curable Thermosetting Epoxy Resin Composition and Manufacturing method}

The present invention relates to a thermosetting epoxy resin composition and a method for producing the same. More specifically, the present invention is made by adding a curing agent, an adhesion promoter, a latent curing accelerator, and a filler by using a new modified epoxy resin as a base resin, and properties such as moisture resistance, impact resistance, and adhesiveness, even when cured at low temperature A superior low temperature curing thermosetting epoxy resin composition suitable for use in electronic materials for heat sensitive electronic components.

In general, bisphenol-type epoxy resins are widely used as resins for electric and electronic component materials because they have excellent dimensional stability of the cured product itself, contain aromatic rings, and have excellent chemical resistance and heat resistance. Since the bisphenol-type epoxy resin is mainly applied to electrical and electronic components, physical properties such as adhesion, moisture resistance, crack resistance, and impact resistance should be good.

As a conventional technique for improving the physical properties of such a bisphenol-type epoxy resin, a method of mixing a phenol novolac resin or an acid anhydride resin with a bisphenol-type epoxy resin as a curing agent is known.

However, when the phenol novolak resin is applied, the heat resistance and the moisture resistance of the cured product may be improved, but the control of the ionic impurity content of the cured resin itself may be difficult, resulting in deterioration of electrical characteristics. In addition, when the acid anhydride resin is used as a curing agent, the elasticity coefficient of the cured product is low, and thus a problem of poor crack resistance occurs during the cold and accelerated test. Therefore, there is a limit in making reliable electric and electronic materials.

In addition, the conventional epoxy resin is a curing temperature is determined according to the type of the curing agent, high temperature curing of about 140 ~ 170 ℃ for the novolak or acid anhydride curing agent, about 90 ~ 130 ℃ for the modified amine / amide or imidazole curing agent There is a limit to the application of heat sensitive electronic components due to the conditions required.

In order to solve the above-mentioned problems, the present inventors prepare a new type of modified epoxy resin, and add another component as a base resin to prepare a new composition, thereby curing at low temperature (about 60 to 80 ° C.). It is to develop a low-temperature curing thermosetting epoxy resin composition excellent in physical properties such as adhesion, moisture resistance, impact resistance, crack resistance.

It is an object of the present invention to provide a new type of modified epoxy resin.

In addition, another object of the present invention is to provide a thermosetting epoxy resin composition having excellent low-temperature curability, excellent adhesion, moisture resistance, impact resistance and crack resistance, etc. as a base resin of a new type of modified epoxy resin.

The above and other objects of the present invention can be achieved by the present invention described below.

The thermosetting epoxy resin composition of the present invention for achieving the above object is (a) 5 to 20% by weight of a polythiol resin relative to the total weight of the mixture in a mixture of a bisphenol F type epoxy resin and a bisphenol A type epoxy resin Preparing a modified epoxy resin by an addition reaction by adding thereto; (b) 2 to 5% by weight of adhesion promoter, 20 to 50% by weight of filler, 10 to 30% by weight of curing agent, and 1 to 3% by weight of latent curing catalyst are dispersed in the modified epoxy resin. It is prepared through; step.
In the step (a), it is preferable that the bisphenol A epoxy resin has 30 to 60% by weight relative to the total weight of the modified epoxy, and after the polythiol resin is added, it is preferably aged at 60 ° C to 70 ° C and then cooled. Do.
In the step (b), it is preferable to further disperse by adding and dispersing the adhesion promoter and the filler at 30 ~ 50 ℃ after the addition of the curing agent and the latent curing catalyst.
In addition, the curing agent is a liquid, a polythiol resin containing three or more thiol groups in the molecule, the adhesion promoter is a silane compound having an epoxy group at the terminal, the latent curing accelerator is a modified aliphatic polyamine compound, the filler It is preferred to use at least one selected from the group consisting of crystalline silica, amorphous silica, aluminum hydroxide and calcium carbonate.

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According to the present invention, a new type of modified epoxy resin can be provided, and the thermosetting epoxy resin composition prepared using the modified epoxy resin as a base resin is excellent in adhesive strength, moisture resistance, impact resistance and crack resistance even under low temperature curing conditions. Effect.

Simple modifications and variations of the present invention can be readily used by those skilled in the art, and all such variations or modifications can be considered to be included within the scope of the present invention.

The thermosetting epoxy resin composition according to the present invention comprises a modified epoxy resin (A), a curing agent (B), an adhesion promoter (C), a latent curing accelerator (D) and a filler (E).

The modified epoxy resin (A) of the present invention is a base resin of the whole composition. This modified epoxy resin (A) is used in 20 to 50 weight% with respect to the whole composition.

The modified epoxy resin (A) is produced by adding a polythiol resin to a bisphenol type epoxy resin.

It is preferable that bisphenol type epoxy resin has 2 or more epoxy groups in a molecule | numerator, and epoxy equivalent is 150-300 g / eq.

In the present invention, the bisphenol-type epoxy resin can be used alone and selected from bisphenol F-type epoxy resin and bisphenol-A epoxy resin, but it is preferable to use a mixture for higher reliability.

At this time, the bisphenol A resin is preferably 30 to 60% by weight based on the total weight of the bisphenol-type epoxy resin, and should not exceed 60% by weight. If the weight ratio of the bisphenol A epoxy resin exceeds 60%, the viscosity of the composition is increased to affect workability, and the modulus of the cured product is increased to cause cracking resistance.

On the other hand, when the weight ratio of the bisphenol A-type epoxy resin is less than 30%, the durability of the composition is lowered, resulting in a problem that the adhesive strength is lowered.

A polythiol resin is added to the bisphenol-type epoxy resin to prepare a modified epoxy resin (A). The polychiol resin has two thiol groups at its ends and is present in a liquid phase having an acid value of up to 5 mgKOH / g.

In the present invention, the polythiol resin is 5 to 20% by weight based on the total weight of the epoxy resin mixture, by addition reaction to produce a modified epoxy resin. Preferably, about 10% by weight is used, and when used in more than 20% by weight, it is difficult to prepare the epoxy resin composition due to the increase in the viscosity of the modified epoxy resin, and the workability of the composition is also lowered.

The modified epoxy resin produced through such a manufacturing process is a high reliability resin having excellent curability and adhesiveness at low temperatures and a flexible molecular structure with improved impact resistance and crack resistance. In addition, the modified epoxy resin in the present invention preferably has an epoxy equivalent of 200 ~ 350 g / eq, the viscosity of 15,000 ~ 35,000 cps (25 ℃) range.

In the thermosetting epoxy resin composition of the present invention, an adhesion promoter (C) and a filler (E) are added to the above-described modified epoxy resin (A) to disperse the mixture, and then a curing agent (B) and a latent curing catalyst (D) are added. It is prepared through the process of further dispersion.

The curing agent (B) used in the composition according to the present invention preferably uses a one-part hardening agent in order to improve workability and to prevent a decrease in reliability due to a difference in the ratio of the base resin and the curing agent. Do. Furthermore, in order to increase storage stability and pot life at room temperature, and to lower the flowability and modulus of the cured composition, a polythiol resin containing three or more thiol groups in a molecule is used. In the present invention, the curing agent (B) is preferably used 10 to 30% by weight based on the total weight of the composition.

Adhesion promoters (C) used in the present invention is a silane-based compound is used to increase the adhesion to the industrial plastic (Engineering Plastic), Printed Circuit Board (Silicone die) and the interface bonded to the composition Preferably the epoxy silane compound which has an epoxy group at the terminal is used. The content of the adhesion promoter (C) used in the present invention is 2 to 5% by weight based on the total weight of the composition.

The latent curing accelerator (D) used in the present invention serves to improve the continuous workability when using the composition by extending the life time of the composition. These latent curing accelerators are modified aliphatic polyamine compounds and are preferably stable at room temperature and activated at high temperatures. In the present invention, the latent curing accelerator (E) is used in an amount of 1 to 3% by weight based on the total weight of the composition.

Filler (E) of the present invention is to lower the coefficient of thermal expansion of the composition, crystalline or amorphous silica, aluminum hydroxide, calcium carbonate and the like can be used alone or in combination. Among these, it is preferable to use spherical silica whose average particle size is 0.5-10 micrometers. Further, in order to impart thixotropic properties of the composition in accordance with the characteristics of the electrical and electronic components to be applied, fused silica may be used. Filler (E) in the present invention uses 20 to 50% by weight based on the total composition.

The epoxy resin composition according to the present invention can be produced by a method for producing a conventional resin composition using the above-described components. Through the epoxy resin composition thus prepared, it is possible to manufacture various types of adhesives, molded articles, reinforcing materials and the like.

The epoxy resin composition according to the present invention ensures high reliability of electrical and electronic components even under harsh external environments. In particular, since it has excellent low temperature curing characteristics, it is sensitive to external heat and uses a sensor component or an industrial plastic to work at low temperatures. It can be applied to applications such as structural adhesives for electrical and electronic components, liquid encapsulants, die attach adhesives, and the like.

< Example  >

Preparation of Modified Epoxy Resin (A)

1. Bisphenol F type epoxy resin (Kukdo Chemical, product name: YDF-720) with epoxy equivalent of 170 g / eq in a 2 L reactor equipped with a nitrogen tube, air condenser, stirrer, thermometer, and heater, and epoxy equivalent 190 g / eq. Phosphorous bisphenol A epoxy resin (Kukdo Chemical, product name: YD-128) was added to the contents shown in Table 1, followed by mixing with agitation while gradually injecting nitrogen gas.

0.1 parts by weight of a tertiary amine Tri (Dimethylamine) Phenol was added as a reaction catalyst, and then a polythiol resin (Bruno Buck, product name: GDMP) having two thiol groups at the end was used for the exothermic reaction. Add dropwise slowly over time. After all of the polythiol resin was added, the temperature was maintained at 60 to 70 ° C. for 3 hours, followed by cooling to prepare modified epoxy resins of (a ₁ ) to (a ₅ ) in Table 1 below. g).

(a ₁ ) (a ₂ ) (a ₃ ) (a ₄ ) (a ₅ ) Bisphenol F type epoxy resin 500 700 400 500 500 Bisphenol A type epoxy resin 500 300 600 500 500 Polythiol resin 100 100 100 50 200 Epoxy equivalent weight (g / eq) 232 227 236 199 339 Viscosity (cps, 25 ℃) 21,000 18,000 31,000 15,000 34,000

Example  1-3 and Comparative Example  1 ~ 4

Using the modified epoxy resin ((a ₁ ) to (a ₅ )) prepared by the above-described method was prepared according to the content of Table 2, respectively.

Specifically, a modified epoxy resin (A), adhesion promoter (C) and filler (E) are added to a 5 L container equipped with a disperser and a thermometer, and the maximum particle size is 15 μm for 2 hours at 30 to 50 ° C. at 1,000 to 3,000 RPM. It disperse | distributed to the following. After the addition of the curing agent (B) and the latent curing catalyst (D) was further dispersed for 30 minutes at 500 ~ 1,000 RPM. At this time, temperature was adjusted using cooling water so that the temperature of a composition might not be heated up above 50 degreeC. Then, the packaging was cooled using a 400 mesh filter when the target particle size range was reached.

The specifications of the components used in this example are as follows, and the components and contents of the prepared composition are shown in Table 2 (each content unit is weight percent).

(1) Modified epoxy resin: (a ₁ ) to (a ₅ ) in Table 1 above

(2) bisphenol A epoxy resin:

    Epoxy equivalent 190 g / eq, Kukdo Chemical, product name: YD-128

(3) Hardener: Bruno Buck, Product Name: TMPMP

(4) latent curing catalyst: Fujikasei, product name: FXR-1020

Example Comparative Example One 2 3 One 2 3 Modified Epoxy Resin (A) (a ₁ ) 40 - - - - - (a ₂ ) - 40 - - - - (a ₃ ) - - 40 - - - (a ₄ ) - - - 40 - - (a ₅ ) - - - - 40 - Bisphenol A type epoxy resin - - - - - 40 Curing agent (B) 25 25 25 30 15 30 Adhesion Promoter (C) 4 4 4 4 4 4 Latent Curing Catalyst (D) One One One One One One (E) Filling 25 25 25 25 25 25 Chixotropic 5 5 5 5 5 5 Viscosity (cps, 25 ℃) 40,000 35,000 52,000 32,000 60,000 30,000 Thixotropic Index 3 3 3 3 3 3

Reliability evaluation

Using each composition prepared in the above Examples and Comparative Examples, 50 evaluation specimens were prepared for each composition, and the reliability evaluation was performed, and the results are summarized in Table 3 below.

The reliability evaluation is an industrial plastic product used for electrical and electronic parts. The items required for the image sensor protection housing adhesive for camera modules, which are particularly sensitive to heat and require low temperature curing properties, are applied as follows.

First, the printed circuit board was dried in an oven at 125 ° C. for 1 hour to prepare a specimen, and then each composition manufactured in the Examples and Comparative Examples using a dispenser device of Protech Co. Was applied.

The housing material adhesive was linearly applied to the printed circuit board supplied to the dispenser in a □ shape, and then the housing material was bonded onto the printed circuit board to which the adhesive was applied in the housing attach section. Thereafter, the printed circuit board discharged from the dispenser was put in an oven, heated to 70 ° C. for 10 minutes, and then cured while maintaining at 70 ° C. for 30 minutes.

Evaluation method for each item of reliability evaluation was performed as follows.

(1) Adhesiveness: The adhesive strength with the housing material was measured using a shear strength tester.

(2) Moisture Resistance: According to IPC / JEDEC J-STD-020C, the adhesive strength with the housing material was measured using a shear strength tester after moisture absorption for 120 hours at 85 ° C./85%RH.

(3) Crack resistance: According to ASTM D-1647, after the thermal shock test for 30 minutes at -40 ° C to 85 ° C for 100 minutes each, it was confirmed by an optical microscope whether cracks of the adhesive occurred. The evaluation results are expressed as (number of defective specimens) / (total number of specimens).

(4) Impact resistance: The assembled module was confirmed by an optical microscope for crack generation at the corners of the cured adhesive after 100 drop reliability tests at a height of 1.52 m. The evaluation results are expressed as (number of defective specimens) / (total number of specimens).

Housing material Example Comparative Example One 2 3 One 2 3 Adhesiveness (kgf) PA6T 22 20 20 18 21 15 PA9T 20 20 18 17 18 15 PC 18 16 20 16 16 12 PA46 20 20 20 18 17 14 LCP 17 17 18 15 16 12 Moisture Resistance (kgf) PA6T 17 15 17 16 12 12 Crack resistance PA6T 0/50 0/50 0/50 7/50 2/50 10/50 Impact resistance PA6T 0/50 0/50 0/50 5/50 1/50 8/50

As described above, the optimum embodiment has been disclosed in the drawings and the specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The thermosetting epoxy resin composition of the present invention may be mainly used for electronic materials of heat-sensitive electronic components, and may also be used in fields requiring low temperature curing properties.

Claims (15)

(a) adding a polythiol resin to a mixture of bisphenol F type epoxy resin and bisphenol A type epoxy resin in an amount of 5 to 20% by weight based on the total weight of the mixture to prepare a modified epoxy resin by an addition reaction; (b) 2 to 5% by weight of adhesion promoter, 20 to 50% by weight of filler, 10 to 30% by weight of curing agent, and 1 to 3% by weight of latent curing catalyst are dispersed in the modified epoxy resin. Making a step; Method for producing a thermosetting epoxy resin composition comprising a. The method of claim 1, wherein step (a) comprises: Bisphenol A epoxy resin has a 30 to 60% by weight relative to the total weight of the modified epoxy, the method of producing a thermosetting epoxy resin composition. The method of claim 1, wherein step (a) comprises: A method of producing a thermosetting epoxy resin composition, wherein the polythiol resin is added and then aged at 60 ° C to 70 ° C and cooled. According to claim 1, wherein step (b), A method of producing a thermosetting epoxy resin composition, wherein the adhesion promoter and the filler are added and dispersed at 30 to 50 ° C., and then the curing agent and the latent curing catalyst are added and dispersed. The method of claim 1, wherein the curing agent, A method for producing a thermosetting epoxy resin composition, which is a liquid and a polythiol resin containing three or more thiol groups in a molecule. According to claim 1, wherein the adhesion promoter, It is a silane type compound which has an epoxy group at the terminal, The manufacturing method of the thermosetting epoxy resin composition characterized by the above-mentioned. The method of claim 1, wherein the latent curing accelerator, It is a modified aliphatic polyamine compound, The manufacturing method of the thermosetting epoxy resin composition characterized by the above-mentioned. The method of claim 1, wherein the filler At least one selected from the group consisting of crystalline silica, amorphous silica, aluminum hydroxide and calcium carbonate. A thermosetting epoxy resin composition prepared by the method of any one of claims 1 to 8. delete delete delete delete delete delete