KR20190074143A - Adhesive composition for automobility - Google Patents

Abstract

The present invention relates to an adhesive composition for a vehicle, which has excellent shear strength, impact strength, and peel strength, and does not generate cracks. The adhesive composition for a vehicle of the present invention comprises: a main resin including first to third epoxy resins; and a curing agent.

Description

Adhesive composition for automobility [0001]

More particularly, the present invention relates to an adhesive composition for automobiles having low flowability, excellent in shear strength, impact strength and peel strength, free from cracks, and excellent in elongation and water resistance will be.

The automobile industry has recently been attempting to lighten its fuel consumption through a high fuel efficiency engine in order to drastically reduce fuel consumption by vehicle type in accordance with strengthened legal regulations. Today, the lightweight design of automobiles requires new bonding techniques with an increase in new materials or mixture of materials. Adhesive technology enables the use of new materials, bonding new materials, and provides structural benefits to bonded components.

The development direction of the structural adhesive is to improve the mechanical properties of the structural adhesive. In addition to improving the mechanical properties, one of the most important ones is the lowering of the price, the longer the pot life after mixing, It is the development of short glue.

On the other hand, adhesives that can be used in the automobile and aerospace industries can strengthen the bonding between the machine parts and increase the stiffness of the joints, so that the strength of the bonded parts can be increased. In addition to having high breaking elongation, do.

However, in the case of conventional adhesives, the strength is relatively low when stress is applied perpendicularly to the bonding surface. That is, the adhesive surface tends to have high strength and fall in a direction perpendicular to the adhesive surface. Accordingly, it is urgent to develop a structural adhesive composition which is less flowable, has excellent shear strength, impact strength and peel strength, is free from cracks, and has excellent elongation and water resistance.

KR 10-1991-0015676 A (Released date: September 30, 1991)

Disclosure of the Invention The present invention has been devised to solve the problems described above, and it is an object of the present invention to provide a bonding composition for automobiles having low flowability, excellent shear strength, impact strength and peel strength, There is a purpose.

In order to solve the above-mentioned problems, the present invention provides a resin composition comprising: a main resin comprising a first epoxy resin, a second epoxy resin and a third epoxy resin; And a curing agent, wherein the first epoxy resin, the second epoxy resin and the third epoxy resin satisfy the following conditions (1) and (2).

(One)

(2)

B is the viscosity (cps) of the second epoxy resin at 30 DEG C, and c is the viscosity (cps) of the third epoxy resin at 25 DEG C. The term " cps " .

According to one embodiment of the present invention, the first epoxy resin, the second epoxy resin and the third epoxy resin can satisfy the following conditions (1) and (2).

(One)

임.(2)

being.

The first epoxy resin may have a viscosity of 10,000 to 15,000 cps at 25 ° C, the second epoxy resin may have a viscosity of 65,000 to 150,000 cps at 30 ° C, and the third epoxy resin may have a viscosity May be 300 to 1000 cps.

The first epoxy resin may be a bisphenol A epoxy resin, and the second epoxy resin may be at least one resin selected from a urethane-modified epoxy resin and a CTBN (carboxyl terminated butadiene acrylonitrile) modified epoxy resin, 3 epoxy resin may be a dimeric acid-modified epoxy resin.

The main resin may include the first epoxy resin, the second epoxy resin and the third epoxy resin in a weight ratio of 1: 0.8 to 1.5: 0.05 to 0.3.

The second epoxy resin may contain a urethane-modified epoxy resin and a CTBN-modified epoxy resin in a weight ratio of 1: 0.05 to 0.3.

The curing agent may be included in an amount of 3 to 12 parts by weight based on 100 parts by weight of the main resin, and the curing accelerator may be further added in an amount of 0.3 to 3 parts by weight.

Also, it may further comprise 14 to 35 parts by weight of a calcium compound based on 100 parts by weight of the main resin.

Also, 0.3 to 3 parts by weight of the physical property enhancer may be added to 100 parts by weight of the main resin.

In addition, the viscosity reinforcing agent may be added in an amount of 1.5 to 10 parts by weight based on 100 parts by weight of the main resin.

INDUSTRIAL APPLICABILITY The automotive adhesive composition of the present invention has low flowability, excellent shear strength, impact strength and peel strength, and is free from cracks, and has an excellent elongation and water resistance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

An automotive adhesive composition according to an embodiment of the present invention comprises a main resin comprising a first epoxy resin, a second epoxy resin and a third epoxy resin; And a curing agent.

Before describing each constitution contained in the adhesive composition for automobile according to the present invention, the first epoxy resin, the second epoxy resin and the third epoxy resin provided in the main resin of the adhesive composition for automobile of the present invention satisfy the following conditions 1) and the condition (2) must be satisfied.

When the viscosity of the automotive adhesive composition is low, there is a problem that the flowability to the desired level is low and the effect of the shear strength, the impact strength and the peel strength are far superior to each other. Also, when the viscosity of the automotive adhesive composition is high, cracking can not be prevented to a desired level, the elongation may be lowered, and the durability may be lowered as the buffering effect against the external impact is lowered.

Accordingly, the first epoxy resin, the second epoxy resin and the third epoxy resin provided in the main resin of the adhesive composition for automobiles of the present invention satisfy the following conditions (1) and (2) do.

이고, 바람직하게는

일 수 있으며, 조건 (2)로써,

이고, 바람직하게는

일 수 있다.As the condition (1)

, And preferably

, And as condition (2)

, And preferably

Lt; / RTI >

B is the viscosity (cps) of the second epoxy resin at 30 DEG C, and c is the viscosity (cps) of the third epoxy resin at 25 DEG C. The term " cps " .

이 0.27 미만이면 목적하는 수준의 전단강도, 충격강도 및 신율을 발현할 수 없고, 자동차용 접착 조성물이 목적하는 점도 수준에 비하여 작은 점도를 나타내어 흐름성이 높아지는 문제가 발생할 수 있다. 또한, 만일 상기 조건 (2)에서

이 4.3 미만이면 목적하는 수준의 충격강도 및 신율을 발현할 수 없는 문제가 발생할 수 있다.If, in the above condition (1)

Is less than 0.27, the desired level of shear strength, impact strength and elongation can not be exhibited, and the viscosity of the automotive adhesive composition may be lower than the desired viscosity level, resulting in increased flowability. If the above condition (2) is satisfied

Is less than 4.3, problems may occur that the desired impact strength and elongation can not be exhibited.

Hereinafter, the respective constituents included in the adhesive composition for automobiles will be described in detail.

First, the main resin comprising the first epoxy resin, the second epoxy resin and the third epoxy resin contained in the adhesive composition for automobile according to the present invention will be described.

The first epoxy resin serves to improve the shear strength of automotive adhesive compositions. Any epoxy resin that can be used to improve the shear strength in the art can be used without limitation, and preferably bisphenol A type Epoxy resin.

The first epoxy resin may have a viscosity of preferably 10,000 to 15,000 cps at 25 캜 and more preferably 11,500 to 13,500 cps to satisfy the conditions (1) and (2) . If the viscosity of the first epoxy resin is less than 10,000 cps at 25 캜, there is a problem in that it is difficult to uniformly mix the calcium carbonate and the curing agent when the mixture is mixed with the calcium carbonate and the curing agent so that the desired level of shear strength can not be expressed If the viscosity exceeds 15,000 cps, the workability of the mixing process may be difficult, and there may be a problem that the uncured portion may remain after curing, so that the desired level of shear strength can not be expressed have.

The second epoxy resin serves to improve impact strength and elongation of an automotive adhesive composition. Any epoxy resin that can be used in the art to improve impact strength and elongation can be used without limitation, Preferably, it may be at least one kind selected from a urethane-modified epoxy resin and a CTBN (Carboxylated Terminated Butadiene Acrylonitrile) modified epoxy resin, more preferably a urethane-modified epoxy resin and a CTBN-modified epoxy resin.

When the urethane-modified epoxy resin and the CTBN-modified epoxy resin are used in combination as described above, the urethane-modified epoxy resin and the CTBN-modified epoxy resin in the second epoxy resin are used in a weight ratio of 1: 0.05 to 0.3, preferably 1: To 0.25 by weight. If the weight ratio of the urethane-modified epoxy resin and the CTBN-modified epoxy resin is less than 1: 0.05, toughness can not be imparted to the epoxy cured product, so that the impact resistance may be lowered and the cohesive failure ratio may be decreased. If it is more than 0.3, toughness may be given, but it may be vulnerable to exposure to the environment such as water and thus the water resistance may be deteriorated.

The second epoxy resin may have a viscosity of preferably 65,000 to 150,000 cps, more preferably 80,000 to 140,000 cps at 30 ° C so as to satisfy the conditions (1) and (2) . If the viscosity of the second epoxy resin is less than 65,000 cps at 30 ° C, there may be a problem that the flowability of the final adhesive composition increases. When the viscosity exceeds 150,000 cps, mixing heat is generated to deteriorate thermal stability, There is a possibility that the equipment dischargeability of the mixture is reduced, cracking can not be prevented after curing of the composition, and the elongation may be lowered.

The third epoxy resin serves to control the viscosity of an automotive adhesive composition to exhibit a desired level of viscosity. Any epoxy resin generally used in the art for controlling viscosity can be used without limitation, Preferably, it may be a dimer acid modified epoxy resin.

The third epoxy resin may have a viscosity of preferably 300 to 1,000 cps, more preferably 400 to 900 cps at 25 캜 so as to satisfy the above condition (1). If the viscosity of the third epoxy resin is less than 300 cps or more than 1,000 cps at 25 占 폚, it affects the dischargeability of the equipment and the wettability of the adherend material may deteriorate.

On the other hand, the main resin is prepared by mixing the first epoxy resin, the second epoxy resin and the third epoxy resin in a weight ratio of 1: 0.8-1.5: 0.05-0.3, preferably 1: 0.9-1.4: 0.1-0.25 . If the weight ratio of the first epoxy resin and the second epoxy resin is less than 1: 0.8, there may be a problem that the desired impact strength and elongation can not be exhibited. If the weight ratio exceeds 1: 1.5, There is a problem that the shear strength can not be expressed. If the weight ratio of the first epoxy resin and the third epoxy resin is less than 1: 0.05, cracking can not be prevented after the curing of the adhesive composition for automobiles, the elongation can be lowered, and the weight ratio is more than 1: 0.3 There is a problem that the desired level of shear strength can not be expressed.

Next, the curing agent contained in the adhesive composition for automobile according to the present invention will be described.

The curing agent is not particularly limited as long as it is a curing agent that can be used in the art for curing an epoxy resin, and may be preferably dicyandiamide.

The properties of the curing agent are not limited. For example, the curing agent may be solid or liquid. When the property of the curing agent is a solid phase, the curing agent may have an average particle diameter of 45 μm or less, preferably an average particle diameter of 40 μm or less, but the present invention is not limited thereto.

The adhesive composition for automobile according to the present invention may contain the curing agent in an amount of 3 to 12 parts by weight, preferably 4 to 10 parts by weight, based on 100 parts by weight of the main resin. If the amount of the curing agent is less than 3 parts by weight based on 100 parts by weight of the main resin, the flowability is increased and the automotive adhesive composition is not cured to the desired level. The shear strength, impact strength and peel strength may be lowered, Exceeds 12 parts by weight, cracks may occur, and the elongation may be lowered.

In addition, the automotive adhesive composition according to the present invention may further comprise a curing accelerator.

The curing accelerator may be any material that can be used as a curing accelerator in the art, and may be preferably phenyl dimethyl urea. In addition, there is no limitation on the properties of the curing accelerator. For example, the curing accelerator may be solid or liquid, and preferably, the curing accelerator may be solid.

The curing accelerator may be added in an amount of 0.3 to 3 parts by weight, preferably 0.5 to 2.5 parts by weight based on 100 parts by weight of the main resin. If the amount of the curing accelerator is less than 0.3 parts by weight based on 100 parts by weight of the main resin, curing to a desired level may not be achieved, and there may be a problem in exhibiting a desired strength. When the amount is more than 3 parts by weight, .

The automotive adhesive composition according to the present invention may further comprise a calcium compound.

The calcium compound is not limited as long as it can function to improve moisture absorption, viscosity, specific gravity control and peel strength. For example, the calcium compound may be calcium oxide for a hygroscopic agent, calcium carbonate for controlling viscosity and specific gravity, May be used singly or in combination.

The calcium compound may be added in an amount of 14 to 35 parts by weight, preferably 21 to 29 parts by weight based on 100 parts by weight of the main resin. If the calcium compound is out of the above content range, the shear strength, impact strength, peel strength and water resistance may be lowered.

The automotive adhesive composition according to the present invention may further include a physical property enhancing agent to improve the peel strength.

The physical property enhancer can be used without limitation as long as it is a physical property enhancer that can be generally used in the art to improve the peel strength. Preferably, the epoxy silane is used to improve the peel strength.

The physical property enhancer may be added in an amount of 0.3 to 3 parts by weight, preferably 0.5 to 2.5 parts by weight, based on 100 parts by weight of the main resin. If the physical property-enhancing agent is less than 0.3 part by weight with respect to 100 parts by weight of the main resin, the improvement in peel strength may be insignificant. If the amount is more than 3 parts by weight, the adhesive force may decrease due to the effect of the unreacted material.

In addition, the automotive adhesive composition according to the present invention may further comprise a viscosity reinforcing agent to improve the viscosity and prevent the composition from flowing due to reduced flowability.

The viscosity reinforcing agent may be used without limitation as long as it can improve the viscosity and reduce the flowability in the art. Fumed silica can be preferably used.

The shape and shape of the viscosity reinforcing agent are not limited. For example, the viscosity reinforcing agent may be solid. When the viscosity reinforcing agent is in a solid phase, the viscosity reinforcing agent may have an average particle diameter of 0.1 to 0.5 占 퐉, preferably 0.2 to 0.4 占 퐉, but is not limited thereto.

The viscosity reinforcing agent may be added in an amount of 1.5 to 10 parts by weight, preferably 3 to 9 parts by weight based on 100 parts by weight of the main resin. If the viscosity reinforcing agent is less than 1.5 parts by weight based on 100 parts by weight of the main resin, the flowability may be increased. If the viscosity improver is more than 10 parts by weight, the viscosity of the adhesive composition becomes very high, The problem may be degraded.

Meanwhile, the automotive adhesive composition according to the present invention may have a viscosity of 7,500 to 22,500 Pa · s, preferably 10,000 to 20,000 Pa · s at 20 ° C, a specific gravity of less than 1.3, and preferably a specific gravity of less than 1.25 .

INDUSTRIAL APPLICABILITY The automotive adhesive composition of the present invention has low flowability, excellent shear strength, impact strength and peel strength, and is free from cracks, and has an excellent elongation and water resistance.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

≪ Example 1 >

A bisphenol A type epoxy resin having a viscosity of 12,500 cps at 25 DEG C as a first epoxy resin, a urethane-modified epoxy resin and a CTBN-modified epoxy resin having a viscosity of 110,000 cps at 30 DEG C and having a viscosity of 110,000 cps and a third epoxy resin Dimeric acid-modified epoxy resins having a viscosity of 650 cps at 25 占 폚 were uniformly mixed at a weight ratio of 1: 1.15: 0.15 using a stirrer as a mixing equipment to prepare a main resin. At this time, the weight ratio of the urethane-modified epoxy resin and the CTBN-modified epoxy resin was 1: 0.15. 25 parts by weight of calcium carbonate, 1.5 parts by weight of epoxy silane as a physical property enhancer, and 6 parts by weight of fumed silica having an average particle diameter of 0.3 占 퐉 as a viscosity reinforcing agent were added to the prepared main resin in an amount of 100 parts by weight of the main resin And then mixed again using a stirrer. The mixed composition was stored in a low-temperature chamber (-10 ° C) and the temperature was lowered. To the composition with the lowered temperature, 6 parts by weight of dicyandiamide having an average particle diameter of 20 μm as a curing agent, , 1.5 parts by weight of phenyldimethylurea was added thereto and mixed using a stirrer, and then the microcapsules inside the sample were removed using a paste mixer to prepare an automotive adhesive composition .

≪ Examples 2 to 15 and Comparative Examples 1 to 9 >

The viscosity and weight ratio of each of the first epoxy resin, the second epoxy resin and the third epoxy resin, the content of the curing agent and the content of the viscosity reinforcing agent were changed as shown in Tables 1 to 4 below, Adhesive compositions for automobiles as shown in Tables 1 to 4 were prepared.

<Experimental Example 1: Properties before curing of automotive adhesive composition>

In order to evaluate the properties before curing of the automotive adhesive composition prepared in Examples and Comparative Examples, the following properties were evaluated and shown in Tables 1 to 4 below.

1. Viscosity Evaluation

200 ml of each of the adhesive compositions for automobiles according to Examples and Comparative Examples was placed in a container, and the mixture was allowed to stand in a chamber so that the temperature of the sample became 20 ± 1 ° C and stirred to keep the temperature of the sample uniform and prevent air bubbles from entering. Thereafter, the spindle (Spindle No. 7) of the viscometer (DV-I PRIME, BROOKFIELD, U.S.A.) was brought to the center of the sample container and immersed to the sink mark of the spindle. At this time, the number of revolutions of the spindle was set to 2 RPM, and the measured value was recorded after rotating for 1 minute and 30 seconds.

2. Specific gravity measurement

First, the weight of the specific gravity cup (1127399, BYK, GERMANY) was measured by using a balance (AJ-4200E-C, SHINKO DENSHI, JAPAN) and the temperature was maintained at 20 ± 1 ° C. Each 100 ml of the adhesive composition for filling was filled with a specific gravity cup so that bubbles would not enter, and the lid was closed. Then, the sample was wiped from the hole located at the center of the lid until the sample was not pushed out. The specific gravity cup was placed on the scale and the weight was measured. The specific gravity was calculated according to the following formula.

[Mathematical Expression]

3. Flow measurement

Each of the adhesive compositions for automobiles according to the examples and comparative examples was applied to a steel sheet having a thickness of 0.8 mm and a width of 75 mm × 150 mm in a shape of a letter "A" having a thickness of 3 mm and a width of 50 mm × 100 mm, Each test specimen was fixed at an angle of 70 ° and the flow was measured at room temperature for 30 minutes. When flowability was good at room temperature, the flowability of the cured adhesive composition was measured using a hot air oven (OVEN, ESPEC, JAPAN) at 180 ° C. for 28 minutes in the same manner.

&Lt; Experimental Example 2: Properties after curing of adhesive composition for automobile &

The following properties were evaluated and evaluated in the following Tables 1 to 4 to evaluate the properties after curing of the adhesive compositions for automobile manufactured in Examples and Comparative Examples.

1. Shear strength measurement

Each of the adhesive compositions for automobiles according to the examples and comparative examples was formed into a steel sheet having a thickness of 0.8 mm and a length of 25 mm x 150 mm and having a thickness of 0.2 mm and a width of 25 mm x 12.5 mm, And the joints were fixed with a clip, and then cured at 180 ° C for 28 minutes using a hot air oven, and then left at room temperature for 1 hour. Shear strength was measured in a universal test machine (ZWICK-Z50, GERMANY) at a speed of 5 mm / min and a tensile load in the direction of 180 °.

2. Water resistance (shear) measurement

Each of the adhesive compositions for automobiles according to the examples and comparative examples was formed into a steel sheet having a thickness of 0.8 mm and a length of 25 mm x 150 mm and having a thickness of 0.2 mm and a width of 25 mm x 12.5 mm, And the joints were fixed with a clip, and then cured at 180 ° C for 28 minutes using a hot air oven, and then left at room temperature for 1 hour. After exposure to water at 40 DEG C for 168 hours, the test piece was left at room temperature for 30 minutes and subjected to a tensile load at a speed of 5 mm / minute and a 180 DEG direction on a universal test machine (ZWICK-Z50, GERMANY) Water resistance (shear) was measured.

3. T peel strength measurement

On each of two steel sheets having a thickness of 0.8 mm and a length of 25 mm x 150 mm, each of the adhesive compositions for automobiles according to Examples and Comparative Examples was formed into a sheet having a thickness of 0.2 mm and a length of 25 mm x 100 mm, using a glass bead The joints were fixed with a clip, and then cured at 180 ° C for 28 minutes using a hot air oven, and then left at room temperature for 1 hour. The joints with no cured products were opened at 180 ° and fixed to the cramp part of a universal test machine (ZWICK-Z50, GERMANY). The tensile load was applied at a speed of 50 mm / min and 180 ° . At this time, the T peel strength value was obtained from a load-displacement curve in a tensile tester.

4. Impact strength measurement

Each of the adhesive compositions for automobiles according to Examples and Comparative Examples was formed into a thickness of 0.2 mm and a width of 20 mm × 30 mm on two bending specimens having a thickness of 1.6 mm and a width of 20 mm × 90 mm, and a glass bead After fixing the joints with a clip, they were cured at 180 ° C for 28 minutes using a hot air oven, and then allowed to stand at room temperature for 1 hour. Each specimen was impacted under the conditions of a weight of 45 kg, height of 0.2 m and speed of 2 m / s using an impact tester (CEAST9350, INSTRON, U.S.A.). At this time, the impact strength value was recorded as an impact strength value at an average load of 25% from the point where the peak starts (point of view) and 10% from the end point.

5. Failure mode Cohesive failure (CF) ratio measurement

Each of the adhesive compositions for automobiles according to the examples and comparative examples was formed into a steel sheet having a thickness of 0.8 mm and a length of 25 mm x 150 mm and having a thickness of 0.2 mm and a width of 25 mm x 12.5 mm, And the joints were fixed with a clip, and then cured at 180 ° C for 28 minutes using a hot air oven, and then left at room temperature for 1 hour. Shear strength was measured in a universal test machine (ZWICK-Z50, GERMANY) at a speed of 5 mm / min and a tensile load in the direction of 180 °. In addition, there are three types of failure phenomena: adhesion failure (AF or Interfacial Failure, IF), cohesive failure (CF), and substrate failure (SF) The ratio of cohesive failure (CF) in failure mode was measured.

6. Elongation measurement

Each of the adhesive compositions for automobiles according to Examples and Comparative Examples was applied to a dumbbell-shaped tensile specimen frame having a thickness of 3 mm and a width of 20 mm and a width of 160 mm, to which a releasing agent had been sufficiently applied, And then left at room temperature for 1 hour. Then, each tensile specimen was separated, and the gauge distance of the specimen was displayed in accordance with the standard and fixed to the cramp portion of the universal test machine (ZWICK-Z50, GERMANY) of the specimen. Thereafter, a load was applied at a tensile speed of 50 mm / min to measure the elongation at break.

division Example
One Example
2 Example
3 Example
4 Example
5 Example 6 The first epoxy
Suzy Viscosity
(cps, 25 &lt; 0 &gt; C) 12,500 11,500 13,500 12,500 12,500 12,500 The second epoxy
Suzy Viscosity
(cps, 30 &lt; 0 &gt; C) 110,000 110,000 110,000 80,000 140,000 200,000 The third epoxy
Suzy Viscosity
(cps, 25 &lt; 0 &gt; C) 650 650 650 650 650 650 Condition (1) (a + b) ^1/2 / c 0.54 0.54 0.54 0.47 0.6 0.71 Condition (2) b / a 8.8 9.6 8.1 6.4 8.8 16 The weight ratio of the first and second epoxy resins 1: 1.15 1: 1.15 1: 1.15 1: 1.15 1: 1.15 1: 1.15 The weight ratio of the first and third epoxy resins 1: 0.15 1: 0.15 1: 0.15 1: 0.15 1: 0.15 1: 0.15 Curing agent content (parts by weight) 6 6 6 6 6 6 Viscosity reinforcing agent content (parts by weight) 6 6 6 6 6 6 Properties before curing Viscosity (Pa 占 퐏, 20 占 폚) 15,000 14,700 15,300 10,500 19,500 24,500 importance 1.2 1.2 1.2 1.1 1.2 1.3 Flow (mm) 2.5 2.5 2.5 2.8 2.5 2.4 Properties after curing Shear strength (Mpa) 21 20 20 21 21 20 Water resistance (shear, Mpa) 21 20 20 21 21 20 T peel strength (N / 25 mm) 250 250 250 245 250 250 Impact strength (N / mm) 30 30 30 30 30 28 Failure mode (%, CF) 90 90 90 90 89 79 Elongation (%) 5.1 5.1 5.1 5.1 5 4.2

division Example
7 Example
8 Example
9 Example
10 Example
11 Example
12 The first epoxy
Suzy Viscosity (cps, 25 캜) 12,500 12,500 12,500 12,500 12,500 12,500 The second epoxy
Suzy Viscosity (cps, 30 ° C) 110,000 110,000 110,000 110,000 110,000 110,000 The third epoxy
Suzy Viscosity (cps, 25 캜) 150 400 900 650 650 650 Condition (1) (a + b) ^1/2 / c 2.33 0.88 0.39 0.54 0.54 0.54 Condition (2) b / a 8.8 8.8 8.8 8.8 8.8 8.8 The weight ratio of the first and second epoxy resins 1: 1.15 1: 1.15 1: 1.15 1: 0.5 1: 2 1: 1.15 The weight ratio of the first and third epoxy resins 1: 0.15 1: 0.15 1: 0.15 1: 0.15 1: 0.15 1: 0.01 Curing agent content (parts by weight) 6 6 6 6 6 6 Viscosity reinforcing agent content (parts by weight) 6 6 6 6 6 6 Properties before curing Viscosity (Pa 占 퐏, 20 占 폚) 13,500 14,200 15,700 9,500 21,000 24,000 importance 1.2 1.2 1.2 1.1 1.3 1.2 Flow (mm) 2.5 2.5 2.5 3.2 2.8 2.7 Properties after curing Shear strength (Mpa) 21 21 21 21 14 20 Water resistance (shear, Mpa) 18 20 21 21 14 20 T peel strength (N / 25 mm) 194 241 242 248 249 224 Impact strength (N / mm) 30 30 30 21 29 20 Failure mode (%, CF) 90 90 90 90 90 79 Elongation (%) 5.1 5.1 5.1 2.8 4.8 2.9

division Example
13 Example
14 Example
15 Example
16 Example
17 Comparative Example
One The first epoxy
Suzy Viscosity (cps, 25 캜) 12,500 12,500 12,500 12,500 12,500 3000 The second epoxy
Suzy Viscosity (cps, 30 ° C) 110,000 110,000 110,000 110,000 110,000 65,500 The third epoxy
Suzy Viscosity (cps, 25 캜) 650 650 650 650 650 980 Condition (1) (a + b) ^1/2 / c 0.54 0.54 0.54 0.54 0.54 0.267 Condition (2) b / a 8.8 8.8 8.8 8.8 8.8 21.8 The weight ratio of the first and second epoxy resins 1: 1.15 1: 1.15 1: 1.15 1: 1.15 1: 1.15 1: 1.15 The weight ratio of the first and third epoxy resins 1: 0.5 1: 0.15 1: 0.15 1: 0.15 1: 0.15 1: 0.15 Curing agent content (parts by weight) 6 One 15 6 6 6 Viscosity reinforcing agent content (parts by weight) 6 6 6 0.5 12 6 Properties before curing Viscosity (Pa 占 퐏, 20 占 폚) 6,500 14,500 16,000 9,000 26,000 13,200 importance 1.2 1.2 1.2 1.2 1.2 1.2 Flow (mm) 3.7 3.9 2.5 4.8 2.4 3.7 Properties after curing Shear strength (Mpa) 15 14 20 20 19 14 Water resistance (shear, Mpa) 14 14 20 19 19 14 T peel strength (N / 25 mm) 239 193 248 251 235 210 Impact strength (N / mm) 28 21 22 29 30 29 Failure mode (%, CF) 90 90 88 89 89 97 Elongation (%) 4.9 5.2 2.2 4.8 1.9 5.0

division Comparative Example
2 Comparative Example
3 Comparative Example
4 Comparative Example
5 Comparative Example
6 Comparative Example
7 The first epoxy
Suzy Viscosity (cps, 25 캜) 20,000 12,500 12,500 - 12,500 12,500 The second epoxy
Suzy Viscosity (cps, 30 ° C) 75,000 40,000 110,000 110,000 - 110,000 The third epoxy
Suzy Viscosity (cps, 25 캜) 650 950 1,500 650 650 - Condition (1) (a + b) ^1/2 / c 0.42 0.24 0.23 0.51 0.17 - Condition (2) b / a 3.75 3.2 8.8 - - 8.8 The weight ratio of the first and second epoxy resins 1: 1.15 1: 1.15 1: 1.15 - - 1: 1.15 The weight ratio of the first and third epoxy resins 1: 0.15 1: 0.15 1: 0.15 - 1: 0.15 - Curing agent content (parts by weight) 6 6 6 6 6 6 Viscosity reinforcing agent content (parts by weight) 6 6 6 6 6 6 Properties before curing Viscosity (Pa 占 퐏, 20 占 폚) 8,300 6,300 23,900 26,000 5,000 28,000 importance 1.2 1.2 1.2 1.2 1.1 1.2 Flow (mm) 3.1 6.1 2.7 2.6 6.6 2.5 Properties after curing Shear strength (Mpa) 13 19 19 10 20 20 Water resistance (shear, Mpa) 13 19 16 9 20 20 T peel strength (N / 25 mm) 233 239 186 243 244 249 Impact strength (N / mm) 18 19 27 30 14 19 Failure mode (%, CF) 88 89 88 90 90 77 Elongation (%) 2.7 2.9 4.3 5 2.1 1.6

As can be seen from Tables 1 to 4 above,

Examples 1 to 5, 8 and 9 satisfying both the viscosity and the weight ratio of each of the first epoxy resin, the second epoxy resin and the third epoxy resin according to the present invention, the content of the curing agent and the content of the viscosity reinforcing agent, The composition did not flow and the ratio of cohesive failure was high and the shear strength, water resistance, T peel strength, impact strength and elongation were lower than those of Examples 6, 7, 10 to 17 and Comparative Examples 1 to 7, Were all excellent at the same time.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

A main resin comprising a first epoxy resin, a second epoxy resin and a third epoxy resin; And
A curing agent,
Wherein the first epoxy resin, the second epoxy resin and the third epoxy resin satisfy the following conditions (1) and (2):
(One)

(2)

B is the viscosity (cps) of the second epoxy resin at 30 DEG C, and c is the viscosity (cps) of the third epoxy resin at 25 DEG C. The term &quot; cps &quot; . The method according to claim 1,
Wherein the first epoxy resin, the second epoxy resin and the third epoxy resin satisfy the following conditions (1) and (2):
(One)

(2)

being. The method according to claim 1,
The first epoxy resin has a viscosity of 10,000 to 15,000 cps at 25 DEG C,
The second epoxy resin has a viscosity of 65,000 to 150,000 cps at 30 DEG C,
Wherein the third epoxy resin has a viscosity of 300 to 1000 cps at 25 占 폚. The method according to claim 1,
Wherein the first epoxy resin is a bisphenol A epoxy resin,
Wherein the second epoxy resin is at least one resin selected from a urethane-modified epoxy resin and a CTBN (Carboxylated Terminated Butadiene Acrylonitrile) modified epoxy resin,
Wherein the third epoxy resin is a dimeric acid-modified epoxy resin. The method according to claim 1,
Wherein the first epoxy resin, the second epoxy resin and the third epoxy resin are contained in a weight ratio of 1: 0.8 to 1.5: 0.05 to 0.3. The method according to claim 1,
Wherein the second epoxy resin comprises a urethane-modified epoxy resin and a CTBN-modified epoxy resin in a weight ratio of 1: 0.05 to 0.3. The method according to claim 1,
Wherein the curing agent is contained in an amount of 3 to 12 parts by weight based on 100 parts by weight of the main resin, and the curing accelerator is further added in an amount of 0.3 to 3 parts by weight. The method according to claim 1,
Wherein the composition further comprises 14 to 35 parts by weight of a calcium compound per 100 parts by weight of the main resin. The method according to claim 1,
Wherein the resin composition further comprises 0.3 to 3 parts by weight of a physical property enhancer based on 100 parts by weight of the main resin. The method according to claim 1,
And a viscosity reinforcing agent in an amount of 1.5 to 10 parts by weight based on 100 parts by weight of the main resin.