KR20200027716A - Adhesive composition for automobility - Google Patents

Abstract

The present invention relates to an adhesive composition for a vehicle and, more specifically, to an adhesive composition for a vehicle, which has less flowability, and has excellent shear strength, impact strength and peel strength, and has excellent elongation and water resistance while not generating cracks. The adhesive composition for a vehicle comprises: a main agent resin; a toughening agent; a moisture absorbent; and a filler.

Description

Adhesive composition for automobiles {Adhesive composition for automobility}

The present invention relates to an adhesive composition for automobiles, and more specifically, an adhesive composition for automobiles having low flowability, superior shear strength, impact strength, and peel strength, and no cracking, and excellent elongation, water resistance, and storage. It is about.

The automobile industry has recently attempted to reduce the fuel consumption by vehicle type through a high fuel economy engine in accordance with strengthening legal regulations. Today's automotive lightweight designs require new bonding techniques with the increase in new materials or material mixtures, which allow the use of new materials, new material bonding, and provide structural advantages to bonded components.

The technical development direction of structural adhesives is to improve the shortcomings of structural adhesives, which not only improves mechanical properties, but also lowers the price of one of the most important ones and increases the pot life after mixing and the curing time after bonding. It is the development of a short adhesive.

On the other hand, with adhesives that can be used throughout the automobile and aerospace industries, it should be possible to increase the strength of the bonded area by hardening the bonds between mechanical parts and increasing the stiffness of the bonds, as well as having a high elongation at break. do.

However, in the case of the conventional adhesive, the strength is relatively low when stress is applied perpendicularly to the adhesive surface. That is, the adhesive surface is high in strength, but is likely to fall in a direction perpendicular to the adhesive surface. Accordingly, there is an urgent need to develop an adhesive composition having low flowability, excellent shear strength, impact strength, and peel strength, and no cracking, and excellent elongation, water resistance, and storage.

KR 10-1991-0015676 A (Public date: 1991.09.30)

The present invention was devised to solve the above-mentioned problems, and has low flow, excellent shear strength, impact strength, and peel strength, and does not generate cracks, and at the same time, has excellent elongation, water resistance, and storage properties. Purpose to provide.

In order to solve the above problems, the present invention, the first resin having a viscosity different from each other, a second resin and a third resin having an epoxy resin; A toughening agent comprising core-shell particles and a fourth epoxy resin, and comprising 8 to 25 parts by weight based on 100 parts by weight of the main resin; Absorbent; And filler; provides an automotive adhesive composition comprising a.

According to an embodiment of the present invention, the core may include at least one selected from the group consisting of polybutadiene (PBd), styrene butadiene rubber (SBR) and polydimethylsiloxane (PDMS), and the shell is an acrylic polymer It may include.

In addition, the core-shell particles may be provided in an amount of 20 to 80 parts by weight based on 100 parts by weight of the fourth epoxy resin.

In addition, 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 of 25 ° C. May be 300 to 1000 cps.

In addition, the toughening agent may have a viscosity of 15,000 to 22,000 cps at 50 ° C.

In addition, the first epoxy resin may be a bisphenol A-type epoxy resin, the second epoxy resin may be one or more resins selected from urethane-modified epoxy resins and CTBN (Carboxyl Terminated Butadiene Acrylonitrile) -modified epoxy resins. The 3 epoxy resin may be a dimer acid-modified epoxy resin, and the 4 epoxy resin may be a bisphenol A type epoxy resin.

Further, the main resin may include the first epoxy resin, the second epoxy resin, and the third epoxy resin in a weight ratio of 1: 1.4 to 2.1: 0.1 to 0.4.

In addition, the second epoxy resin may include urethane-modified epoxy resin and CTBN-modified epoxy resin in a weight ratio of 1: 0.05 to 0.3.

Further, it may further include 4 to 13 parts by weight of the curing agent and 0.5 to 3 parts by weight of the curing accelerator relative to 100 parts by weight of the main resin.

In addition, the moisture absorbent containing calcium oxide with respect to 100 parts by weight of the main resin may include 4 to 13 parts by weight.

In addition, the filler may have two or more types selected from the group consisting of a first filler, a second filler, and a third filler having different shapes.

In addition, the first filler may be a needle-shaped filler having an average particle diameter of 7 to 15㎛, the second filler may be a spherical filler having an average particle diameter of 6 to 14㎛, and the third filler has an average particle diameter It may be a plate-shaped filler of 10 ~ 18㎛.

In addition, the filler may include the first filler, the second filler, and the third filler in a weight ratio of 1: 0.5 to 1.5: 0.5 to 1.5.

In addition, the filler may be included in 10 to 20 parts by weight based on 100 parts by weight of the main resin.

In addition, it may further include 0.5 to 3 parts by weight of a strength improving agent and 1.5 to 11 parts by weight of a viscosity modifier based on 100 parts by weight of the main resin.

The adhesive composition for automobiles of the present invention has low flowability, excellent shear strength, impact strength, and peel strength, and does not cause cracks, but also has excellent elongation, water resistance, and storage properties.

Hereinafter, exemplary embodiments of the present invention will be described in detail so that those skilled in the art may easily implement the present invention. The present invention can be implemented in many different forms and is not limited to the embodiments described herein.

The adhesive composition for automobiles according to an embodiment of the present invention includes a main resin having a first epoxy resin, a second epoxy resin, and a third epoxy resin having different viscosity from each other; Toughening agents comprising core-shell particles and a fourth epoxy resin; Absorbent; And fillers.

Hereinafter, each component included in the adhesive composition for automobiles will be described in detail.

First, a main resin having a first epoxy resin, a second epoxy resin, and a third epoxy resin included in the automotive adhesive composition according to the present invention will be described.

The first epoxy resin serves to improve the shear strength of the adhesive composition for automobiles, and can be used without limitation as long as it is an epoxy resin that can be commonly used in the art to improve shear strength, preferably bisphenol A type It may be an epoxy resin.

In addition, the first epoxy resin may preferably have a viscosity of 10,000 to 15,000 cps at 25 ° C, and more preferably a viscosity of 11,500 to 13,500 cps. If the viscosity of the first epoxy resin is less than 10,000 cps at 25 ° C, it may be difficult to uniformly mix the mixture due to lack of dispersibility when mixing with calcium carbonate and a curing agent, and there may be a problem that a desired level of shear strength cannot be expressed. When the viscosity exceeds 15,000 cps, there may be a problem in that it is difficult to express a desired level of shear strength because an uncured portion may remain after curing, as there may be difficulties in the workability of the mixing process. have.

In addition, the second epoxy resin serves to improve the impact strength and elongation of the adhesive composition for automobiles, and any epoxy resin that can be used to improve the impact strength and elongation in the art can be used without limitation. Preferably, it may be one or more selected from urethane-modified epoxy resins and CTBN (Carboxyl Terminated Butadiene Acrylonitrile) -modified epoxy resins, and more preferably, a urethane-modified epoxy resin and CTBN-modified epoxy resins may be mixed and used.

When using a mixture of urethane-modified epoxy resin and CTBN-modified epoxy resin as described above, the second epoxy resin is urethane-modified epoxy resin and CTBN-modified epoxy resin in a weight ratio of 1: 0.05 to 0.3, preferably 1: 0.1 It can be included in a weight ratio of ~ 0.25. If the weight ratio of the urethane-modified epoxy resin and CTBN-modified epoxy resin is less than 1: 0.05, toughness cannot be imparted to the epoxy cured product, impact resistance is lowered, and agglomeration and destruction ratio may be lowered, and the weight ratio is 1: When it exceeds 0.3, toughness may be imparted, but water resistance may be deteriorated due to vulnerability to environmental exposure such as moisture.

In addition, the second epoxy resin may preferably have a viscosity of 65,000 to 150,000 cps at 30 ° C, and more preferably a viscosity of 80,000 to 140,000 cps. If the viscosity of the second epoxy resin at 30 ° C. is less than 65,000 cps, there may be a problem that the flowability of the final adhesive composition increases, and when the viscosity exceeds 150,000 cps, mixing heat is generated to deteriorate thermal stability. It can reduce the equipment ejection property of the mixture, it is not possible to prevent the occurrence of cracks after curing the composition, there may be a problem that the elongation may be lowered.

In addition, the third epoxy resin serves to exhibit a desired level of viscosity by controlling the viscosity of the adhesive composition for automobiles. Any epoxy resin that can be used to control the viscosity in the art can be used without limitation. It may be preferably a dimer acid modified epoxy resin.

In addition, the third epoxy resin may preferably have a viscosity of 300 to 1,000 cps at 25 ° C, and more preferably a viscosity of 400 to 900 cps. If the viscosity at 25 ° C. of the third epoxy resin is less than 300 cps or exceeds 1,000 cps, it affects the equipment ejection property, and the peel strength may be lowered due to poor wettability of the adherend.

On the other hand, the main resin is the first epoxy resin, the second epoxy resin and the third epoxy resin in a weight ratio of 1: 1.4 ~ 2.1: 0.1 ~ 0.4, preferably 1: 1.5 ~ 2.0: 0.15 ~ 0.35 in a weight ratio It can contain. If the weight ratio of the first epoxy resin and the second epoxy resin is less than 1: 1.4, there may be a problem that the desired level of impact strength and elongation cannot be expressed, and if the weight ratio exceeds 1: 2.1, the desired level There may be a problem that shear strength cannot be expressed. In addition, if the weight ratio of the first epoxy resin and the third epoxy resin is less than 1: 0.1, crack generation after curing of the adhesive composition for automobiles cannot be prevented, elongation may be lowered, and the weight ratio exceeds 1: 0.4. If there is, there may be a problem that the desired level of shear strength cannot be expressed.

Next, the toughening agent included in the adhesive composition for automobiles according to the present invention will be described.

The toughening agent functions to improve impact strength, and includes core-shell particles and a fourth epoxy resin.

The fourth epoxy resin may be used without limitation as long as it is an epoxy resin that can be used in the art, and preferably may be a bisphenol A-type epoxy resin.

On the other hand, the core-shell particles can be used without limitation, as long as it is a material capable of performing a function that can generally improve the impact strength, preferably the core is polybutadiene (PBd), styrene butadiene rubber (SBR), and It may include one or more selected from the group consisting of polydimethylsiloxane (PDMS), the shell may include an acrylic polymer. Accordingly, the impact strength can exhibit a remarkably excellent effect.

In addition, the core-shell particles may be provided in an amount of 20 to 80 parts by weight, preferably 25 to 75 parts by weight based on 100 parts by weight of the fourth epoxy resin. If the core-shell particles are less than 20 parts by weight or more than 80 parts by weight with respect to 100 parts by weight of the fourth epoxy resin, impact strength may not be improved to a desired level. Moreover, when it exceeds 80 weight part, storage property falls.

Meanwhile, the adhesive composition for automobiles according to the present invention may include a toughening agent in an amount of 8 to 25 parts by weight, and preferably a toughening agent in an amount of 10 to 23 parts by weight based on 100 parts by weight of the main resin. If the toughening agent is less than 8 parts by weight with respect to 100 parts by weight of the main resin, the impact strength may not be improved to a desired level, and if it exceeds 25 parts by weight, cracks may occur in the cured composition after curing, but rather impact strength May be deteriorated, and a problem of deterioration in storage may occur.

In addition, the toughening agent may have a viscosity of 15,000 to 22,000 cps at 50 ° C, preferably a viscosity of 16,000 to 21,000 cps at 50 ° C. If the viscosity of the toughening agent at 50 ° C is less than 15,000 cps, a problem may arise where the desired level of impact strength improvement is not expressed as the dispersibility of the core-shell particles is insufficient, and the viscosity at 50 ° C is 22,000. If cps is exceeded, uniform mechanical properties may not be exhibited as the workability of the mixing process may not be good, and thus impact strength may be deteriorated.

Next, the moisture absorbent contained in the adhesive composition for automobiles of the present invention will be described. The hygroscopic agent can be used without limitation as long as it is a material that can be used to absorb moisture in the art, and preferably calcium oxide.

The moisture absorbent may be included in 4 to 13 parts by weight, preferably 5 to 11 parts by weight based on 100 parts by weight of the main resin. If the hygroscopic agent is less than 4 parts by weight based on 100 parts by weight of the main resin, there may be a problem that water resistance cannot be expressed at a desired level, and if it exceeds 13 parts by weight, the viscosity increases, adversely affecting the equipment ejectability of the final mixture. Depending on the workability may be a problem, shear strength and elongation may be reduced.

Next, the filler included in the adhesive composition for automobiles according to the present invention will be described.

The filler may have two or more types selected from the group consisting of a first filler, a second filler, and a third filler having different shapes, and preferably, the first filler, the second filler, and the third filler having different shapes. All can be provided.

The first filler is to function to adjust the viscosity and specific gravity, and in the art, any filler having a shape that can be used to adjust the viscosity and specific gravity can be used without limitation, and preferably, the first filler is a needle bed. It can be a mold filler.

In addition, the first filler may have an average particle diameter of 7 to 15 μm, preferably an average particle diameter of 8 to 14 μm. If the average particle diameter of the first filler is less than 7 μm, viscosity may increase, which may cause problems in ejection of equipment, water resistance and impact strength may decrease, and when the average particle diameter exceeds 15 μm, viscosity decreases to flow. There may be a problem.

The second filler is to function to adjust the viscosity and specific gravity, and in the art, any filler having a shape that can be used to adjust the viscosity and specific gravity can be used without limitation, and preferably, the second filler is envisioned. It can be a mold filler.

In addition, the second filler may have an average particle diameter of 6 to 14 μm, preferably an average particle diameter of 7 to 13 μm. If the average particle diameter of the second filler is less than 6 μm, the brittleness increases and becomes hard, so there may be a problem that the impact strength decreases. When the average particle diameter exceeds 14 μm, the brittleness decreases and becomes flexible, so that the shear strength is high. There may be a problem of decreasing.

The third filler has a function of improving peel strength, and any filler having a shape that can be generally used in the art to improve peel strength can be used without limitation, and preferably, the third filler is a plate-shaped filler. You can.

In addition, the third filler may have an average particle diameter of 10 to 18 μm, preferably an average particle diameter of 11 to 17 μm. If the average particle diameter of the third filler is less than 10 μm, there may be a problem that the peeling state is poor during the T-peel test, and if the average particle diameter exceeds 18 μm, there may be a problem of reducing the impact strength.

The first filler, the second filler, and the third filler can be used without limitation as long as they are fillers that can be generally used in the art to adjust viscosity and specific gravity and improve peel strength, and preferably, the first filler and the second filler. The filler and the third filler may be calcium carbonate.

On the other hand, the filler, the first filler, the second filler and the third filler in a weight ratio of 1: 0.5 to 1.5: 0.5 to 1.5, preferably the first filler, the second filler and the third filler 1: 0.7 ~ 1.4: may be included in a weight ratio of 0.7 to 1.4. If the weight ratio of the first filler and the second filler is outside the above range, there may be a problem that the desired level of viscosity and specific gravity of the adhesive composition for automobiles cannot be adjusted. In addition, if the weight ratio of the first filler and the third filler is less than 1: 0.5, the improvement in peel strength may be negligible, and when the weight ratio exceeds 1: 1.5, the desired level of viscosity and specific gravity of the adhesive composition for automobiles can be adjusted. There may be a problem that cannot be.

In addition, the adhesive composition for automobiles of the present invention may include 10 to 20 parts by weight of the filler, preferably 12 to 18 parts by weight, with respect to 100 parts by weight of the main resin to be described later. If the filler is less than 10 parts by weight with respect to 100 parts by weight of the main resin, the adhesive composition for automobiles may not exhibit the desired viscosity and specific gravity, and peel strength may deteriorate. If the filler exceeds 20 parts by weight, the viscosity and As the specific gravity becomes excessive, problems such as shear strength and impact strength may decrease.

Meanwhile, the adhesive composition for automobiles according to the present invention may further include a curing agent. The curing agent may be used without limitation as long as it is a curing agent that can be used to cure epoxy resins in the art, and may be preferably dicyandiamide.

The properties of the curing agent are not limited, and 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 is not limited thereto.

In addition, the adhesive composition for automobiles according to the present invention may further include 4 to 13 parts by weight of the curing agent, preferably 5 to 11 parts by weight based on 100 parts by weight of the main resin. If the curing agent is less than 4 parts by weight based on 100 parts by weight of the main resin, the flowability increases and the shear strength, impact strength, and peel strength may deteriorate as the adhesive composition for automobiles is not cured to the desired level. If it exceeds 13 parts by weight, cracks may occur, and a problem that the elongation decreases may occur.

In addition, the adhesive composition for automobiles according to the present invention may further include a curing accelerator.

The curing accelerator may be used without limitation as long as it can be used as a curing accelerator in the art, preferably phenyl dimethyl urea (Phenyl Dimethyl Urea). In addition, the properties of the curing accelerator are not limited, for example, the curing accelerator may be solid or liquid, and preferably, the curing accelerator may be solid.

The curing accelerator may be further included in 0.5 to 3 parts by weight, preferably 1 to 2.5 parts by weight based on 100 parts by weight of the main resin. If the curing accelerator is less than 0.5 part by weight based on 100 parts by weight of the main resin, it may not be cured to a desired level, and there may be a problem in expressing the desired strength. .

Meanwhile, the adhesive composition for automobiles according to the present invention may further include a strength improving agent to improve peel strength.

The strength improving agent may be used without limitation as long as it is a strength improving agent conventionally used in the art, and preferably, it is easier to improve peel strength by using an epoxy silane.

The strength improving agent may be further included in 0.5 to 3 parts by weight, preferably 1 to 2.5 parts by weight based on 100 parts by weight of the main resin. If the strength improving agent is less than 0.5 part by weight based on 100 parts by weight of the main resin, the degree of peel strength improvement may be insignificant, and if it exceeds 3 parts by weight, there may be a problem that adhesive strength decreases due to the influence of the unreacted composite.

In addition, the adhesive composition for automobiles according to the present invention may further include a viscosity modifier in order to improve viscosity and lower flowability so that the composition does not flow.

The viscosity modifier may be used without limitation as long as it can improve viscosity and lower flowability in the art, and preferably, fumed silica.

The properties and shape of the viscosity modifier are not limited, and for example, the viscosity modifier may be solid. When the viscosity modifier is in the solid phase, the viscosity modifier may have an average particle diameter of 0.1 to 0.5 μm, preferably 0.2 to 0.4 μm, but is not limited thereto.

The viscosity modifier may be further included in 2.5 to 11 parts by weight, preferably 4 to 10 parts by weight based on 100 parts by weight of the main resin. If the viscosity modifier is less than 2.5 parts by weight with respect to 100 parts by weight of the main resin, a problem of increasing flowability may occur, and if it exceeds 11 parts by weight, the viscosity of the adhesive composition becomes very high, resulting in poor workability and elongation after curing. The problem of deterioration may occur.

The adhesive composition for automobiles of the present invention has low flowability, excellent shear strength, impact strength, and peel strength, and does not cause cracks, but also has excellent elongation, water resistance, and storage properties.

The present invention will be described in more detail through the following examples, but the following examples are not intended to limit the scope of the present invention, which should be interpreted to help understand the present invention.

<Example 1>

Bisphenol A type epoxy resin having a viscosity of 12,500 cps at 25 ° C as the first epoxy resin, and urethane-modified epoxy resin and CTBN-modified epoxy resin having a viscosity of 110,000 cps at 30 ° C respectively as the second epoxy resin, as the third epoxy resin A dimeric acid-modified epoxy resin having a viscosity of 650 cps at 25 ° C was uniformly mixed using a mixing equipment, a stirrer, in a weight ratio of 1: 1.75: 0.25 to prepare a main resin. At this time, the weight ratio of the urethane-modified epoxy resin and CTBN-modified epoxy resin was 1: 0.15. To the prepared main resin, 100 parts by weight of the main resin, a bisphenol A-type epoxy resin as a fourth epoxy resin, and a core having a polybutadiene (PBd) and a shell as an acrylic polymer with respect to 100 parts by weight of the fourth epoxy resin- 17 parts by weight of a toughening agent (MX-153, KANEKA) having a viscosity of 18,500 cps at 50 ° C containing 50 parts by weight of shell particles, 8 parts by weight of calcium oxide as a hygroscopic agent, and needle-like carbonate having an average particle diameter of 11 μm as a first filler 5 parts by weight of a calcium filler, 5 parts by weight of a spherical calcium carbonate filler having an average particle diameter of 10 μm as a second filler, 5 parts by weight of a plate-like calcium carbonate filler having an average particle diameter of 14 μm as a third filler, and 1.5 parts of epoxy silane as a strength improving agent. 6 parts by weight of fumed silica having an average particle size of 0.3 µm was added as a weight part and a viscosity modifier, and then mixed again using a stirrer. The mixed composition is stored in a low-temperature chamber (-10 ° C.) to lower the temperature, and to a composition having a lower temperature, 8 parts by weight of dicyandiamide having an average particle diameter of 20 μm as a curing agent relative to 100 parts by weight of the main resin, and a curing accelerator After adding phenyl dimethyl urea to 1.5 parts by weight, the mixture was mixed using a stirrer, and then the mixed composition was used to remove the micro bubbles inside the sample using a paste mixer to prepare an adhesive composition for automobiles. .

<Examples 2 to 21 and Comparative Examples 1 to 3>

Prepared in the same manner as in Example 1, but changed the content of the toughening agent, the content of the core-shell particles, the viscosity of the toughening agent, the viscosity of the first epoxy resin, the second epoxy resin, and the third epoxy resin, etc. Thus, the adhesive compositions for automobiles as shown in Tables 1 to 4 were prepared.

<Experimental Example 1: Pre-curing properties of the adhesive composition for automobiles>

To evaluate the properties of the adhesive composition for automobiles prepared in Examples and Comparative Examples before curing, the following physical properties were evaluated and are shown in Tables 1 to 4.

1. Viscosity evaluation

Each of the adhesive composition for automobiles according to Examples and Comparative Examples was put in a container and left in a chamber such that the temperature of the sample was 20 ± 1 ° C, and the temperature of the sample was kept uniform and stirred to prevent 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 then immersed to the immersion 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 30 seconds.

2. Specific gravity measurement

First, the specific gravity cup (1127399, BYK, GERMANY) is weighed using a balance (AJ-4200E-C, SHINKO DENSHI, JAPAN), and the vehicle according to Examples and Comparative Examples maintaining a temperature of 20 ± 1 ℃ 100 ml each of the adhesive composition for the solvent was carefully filled with a specific gravity cup to prevent air bubbles from entering, and the lid was closed. Then, after the sample was wiped out from the hole located in the center of the lid, the specific gravity cup was placed on the scale to measure the weight, and the specific gravity was calculated according to the following equation.

[Mathematics]

3. Flow measurement

Each of the adhesive composition for automobiles according to Examples and Comparative Examples was applied to a steel plate having a thickness of 0.8 mm and a width × height of 75 × 150 mm in an inverted 'A' shape with a thickness of 3 mm and a width × length of 50 × 100 mm to measure flowability. In order to fix each test piece at an angle of 70 °, the flow after 30 minutes at room temperature was measured. Then, when the flowability was good at room temperature, the flowability of the cured adhesive composition was measured after leaving at 180 ° C for 28 minutes using a hot air oven (OVEN, ESPEC, JAPAN) in the same manner.

4. Evaluation of storage

The adhesive composition for automobiles according to Examples and Comparative Examples was placed in a sealed container for 200 ml each, and left in a chamber maintaining a temperature of 40 ± 1 ° C and a humidity of 95 ± 1% for 7 days, and compared with the viscosity before leaving, the viscosity increase rate The storage was evaluated through a calculation method.

<Experimental Example 2: Properties after curing of the adhesive composition for automobiles>

To evaluate the properties after curing of the adhesive composition for automobiles prepared in Examples and Comparative Examples, the following physical properties were evaluated and are shown in Tables 1 to 4 below.

1. Shear strength measurement

Each of the adhesive composition for automobiles according to Examples and Comparative Examples on a steel plate having a thickness of 0.8 mm and a width and a height of 25 × 150 mm is 0.2 mm in thickness and 25 × 12.5 mm in width and width, respectively, and a thickness is applied using a glass bead. After aligning, and fixing the joint with a clip, it was cured at 180 ° C. for 28 minutes using a hot air oven and left at room temperature for 1 hour. Then, the shear strength was measured by applying a tensile load at a speed of 5 mm / min and 180 ° in a universal test machine (ZWICK-Z50, GERMANY).

2. Water resistance (shear) measurement

Each of the adhesive composition for automobiles according to Examples and Comparative Examples on a steel plate having a thickness of 0.8 mm and a width and a height of 25 × 150 mm is 0.2 mm in thickness and 25 × 12.5 mm in width and width, respectively, and a thickness is applied using a glass bead. After aligning, and fixing the joint with a clip, it was cured at 180 ° C. for 28 minutes using a hot air oven and left at room temperature for 1 hour. Then, after exposure to water at 40 ° C. for 168 hours, it was left at room temperature for 30 minutes, and a tensile load was applied at a speed of 5 mm / min at a universal test machine (ZWICK-Z50, GERMANY) at 180 °. Water resistance (shear) was measured.

3. Measurement of T peel strength

Each of the adhesive compositions for automobiles according to Examples and Comparative Examples on two steel plates having a thickness of 0.8 mm and a width and a height of 25 × 150 mm is 0.2 mm in thickness and 25 × 100 mm in width and width, and glass beads are used. After fixing the thickness and fixing the joint with a clip, it was cured at 180 ° C for 28 minutes using a hot air oven and left at room temperature for 1 hour. Then, open the joints without hardened material at 180 ° and fix each to the clamp part of the universal test machine (ZWICK-Z50, GERMANY), and apply a tensile load in the direction of 180 ° at a speed of 50 mm / min. Added. At this time, the T peel strength value was averaged from the load-displacement curve in the tensile tester.

4. Impact strength measurement

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

5. Fracture mode Coagulation failure (CF) ratio measurement

Each of the adhesive composition for automobiles according to Examples and Comparative Examples on a steel plate having a thickness of 0.8 mm and a width and a height of 25 × 150 mm is 0.2 mm in thickness and 25 × 12.5 mm in width and width, respectively, and a thickness is applied using a glass bead. After aligning, and fixing the joint with a clip, it was cured at 180 ° C. for 28 minutes using a hot air oven and left at room temperature for 1 hour. Then, the shear strength was measured by applying a tensile load at a speed of 5 mm / min and 180 ° in a universal test machine (ZWICK-Z50, GERMANY). And, there are three types of interface failure (Adhesion Failure, AF or Interfacial Failure, IF) of adhesive and adherend, cohesive failure (CF) where adhesive itself is destroyed, and substrate failure (SF). The ratio of cohesive failure (CF) in the failure mode was measured.

6. Elongation measurement

Each of the adhesive composition for automobiles according to Examples and Comparative Examples was applied to a dumbbell-shaped tensile specimen frame having a thickness of 3 mm, a width × length of 20 × 160 mm, and a curing agent was cured at 180 ° C. for 28 minutes using a hot air oven. After standing at room temperature for 1 hour. Then, each tensile specimen was separated to mark the specimen's mark distance according to the specifications, and fixed to the clamp portions of both universal test machines (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 1st epoxy
Suzy Viscosity (cps, 25 ℃) 12,500 12,500 12,500 12,500 12,500 12,500 2nd epoxy resin Viscosity (cps, 30 ℃) 110,000 110,000 110,000 110,000 110,000 110,000 3rd epoxy resin Viscosity (cps, 25 ℃) 650 650 650 650 650 650 Toughening agent Core-shell particle content (parts by weight) 50 50 50 15 25 75 Content (parts by weight) 17 10 23 17 17 17 Viscosity (cps, 50 ℃) 18,500 18,500 18,500 18,500 18,500 18,500 Filler content (parts by weight) 15 15 15 15 15 15 Properties before curing Viscosity (Pa · s, 20 ℃) 14,500 14,400 14,600 14,500 14,500 14,500 importance 1.18 1.18 1.18 1.18 1.18 1.18 Flowability 2.5 2.5 2.5 2.5 2.5 2.5 Storage (viscosity increase rate,%) 11 10 14 10 10 16 Properties after curing Shear strength (Mpa) 23 22.4 22.7 21.9 22.6 22.8 Water resistance (shear, Mpa) 22 21.6 21.6 21.4 21.7 21.6 T Peel strength (N / 25mm) 260 261 258 258 260 261 Impact strength (N / mm) 35.5 33.8 34.1 30.6 34.4 34.2 Destruction mode (%, CF) 90 90 90 90 90 90 % Elongation 8.1 7.7 8.2 7.7 8.0 7.9

division Example
7 Example
8 Example
9 Example
10 Example
11 Example
12 1st epoxy
Suzy Viscosity (cps, 25 ℃) 12,500 8,000 18,000 12,500 12,500 12,500 2nd epoxy
Suzy Viscosity (cps, 30 ℃) 110,000 110,000 110,000 50,000 170,000 110,000 Third Epoxy
Suzy Viscosity (cps, 25 ℃) 650 650 650 650 650 150 Toughening agent Core-shell particle content (parts by weight) 85 50 50 50 50 50 Content (parts by weight) 17 17 17 17 17 17 Viscosity (cps, 50 ℃) 18,500 18,500 18,500 18,500 18,500 18,500 Filler content (parts by weight) 15 15 15 15 15 15 Properties before curing Viscosity (Pa · s, 20 ℃) 14,500 14,300 14,700 13,200 16,800 14,400 importance 1.18 1.18 1.18 1.16 1.2 1.18 Flowability 2.5 2.5 2.5 2.8 2.4 2.5 Storage (viscosity increase rate,%) 33 11 11 11 11 11 Properties after curing Shear strength (Mpa) 21.8 16 15 21 23 23 Water resistance (shear, Mpa) 21.5 15 14 20 22 17 T Peel strength (N / 25mm) 261 220 246 247 260 199 Impact strength (N / mm) 30.7 34 35.5 23.5 35.5 35.5 Destruction mode (%, CF) 90 97 88 89 79 90 % Elongation 7.8 7.9 4.5 4.6 6.3 4.3

division Example
13 Example
14 Example
15 Example
16 Example
17 Example
18 1st epoxy
Suzy Viscosity (cps, 25 ℃) 12,500 12,500 12,500 12,500 12,500 12,500 2nd epoxy resin Viscosity (cps, 30 ℃) 110,000 110,000 110,000 110,000 110,000 110,000 Third Epoxy
Suzy Viscosity (cps, 25 ℃) 1,200 650 650 650 650 650 Toughening agent Core-shell particle content (parts by weight) 50 50 50 50 50 50 Content (parts by weight) 17 17 17 17 17 17 Viscosity (cps, 50 ℃) 18,500 12,000 16,000 21,000 25,000 18,500 Filler content (parts by weight) 15 15 15 15 15 5 Properties before curing Viscosity (Pa · s, 20 ℃) 14,600 13,650 14,250 14,750 15,350 14,200 importance 1.18 1.17 1.18 1.18 1.19 1.18 Flowability 2.7 2.8 2.6 2.5 2.4 2.5 Storage (viscosity increase rate,%) 11 11 11 11 11 11 Properties after curing Shear strength (Mpa) 20 22 23 23 23 16 Water resistance (shear, Mpa) 16 21 22 22 22 15 T Peel strength (N / 25mm) 193 258 258 261 262 186 Impact strength (N / mm) 31 30.8 35.3 35.4 31 28.5 Destruction mode (%, CF) 88 90 90 90 90 78 % Elongation 6.7 7.9 8.1 8.0 7.8 8.0

division Example
19 Example
20 Example
21 Comparative example
One Comparative example
2 Comparative example
3 1st epoxy
Suzy Viscosity (cps, 25 ℃) 12,500 12,500 12,500 12,500 12,500 12,500 2nd epoxy resin Viscosity (cps, 30 ℃) 110,000 110,000 110,000 110,000 110,000 110,000 3rd epoxy resin Viscosity (cps, 25 ℃) 650 650 650 650 650 650 Toughening agent Core-shell particle content (parts by weight) 50 50 50 50 50 - Content (parts by weight) 17 17 17 5 30 - Viscosity (cps, 50 ℃) 18,500 18,500 18,500 18,500 18,500 - Filler content (parts by weight) 12 18 25 15 15 15 Properties before curing Viscosity (Pa · s, 20 ℃) 14,400 14,600 14,700 14,300 14,700 14,000 importance 1.18 1.18 1.18 1.18 1.18 1.17 Flowability 2.5 2.5 2.5 2.5 3.5 2.5 Storage (viscosity increase rate,%) 11 11 11 10 31 10 Properties after curing Shear strength (Mpa) 22.5 22.4 16 21.6 22.5 20 Water resistance (shear, Mpa) 21.5 21.5 15 21.3 22 20 T Peel strength (N / 25mm) 250 254 233 257 248 251 Impact strength (N / mm) 34.2 34.6 27.5 30.4 30.3 30 Destruction mode (%, CF) 90 90 89 90 75 90 % Elongation 8.1 8.1 8.0 6.0 8.5 5.2

As can be seen from Tables 1 to 4 above,

Examples 1 to 3 satisfying the toughener content, core-shell particle content, toughener viscosity, first epoxy resin, second epoxy resin, and third epoxy resin viscosity and filler content according to the present invention , 5, 6, 15, 16, 19 and 20, compared to Examples 4, 7 to 14, 16 to 18, 21 and Comparative Examples 1 to 3 in which any one of them is missing, has excellent storage and low flow. The composition did not flow, the ratio of cohesive failure was high, and the shear strength, water resistance, T peel strength, impact strength, and elongation were all excellent at the same time.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments set forth herein, and those skilled in the art who understand the spirit of the present invention may add components within the scope of the same idea. Other embodiments may be easily proposed by changing, deleting, adding, etc., but this will also fall within the spirit of the present invention.

Claims (15)

A main resin having a first epoxy resin, a second epoxy resin and a third epoxy resin having different viscosity;
A toughening agent comprising core-shell particles and a fourth epoxy resin, and comprising 8 to 25 parts by weight based on 100 parts by weight of the main resin;
Absorbent; And
Filler; automotive adhesive composition comprising a. According to claim 1,
The core comprises at least one selected from the group consisting of polybutadiene (PBd), styrene butadiene rubber (SBR) and polydimethylsiloxane (PDMS),
The shell is an automotive adhesive composition comprising an acrylic polymer. According to claim 1,
The core-shell particles are automotive adhesive compositions provided with 20 to 80 parts by weight based on 100 parts by weight of the fourth epoxy resin. According to claim 1,
The first epoxy resin has a viscosity of 10,000 ~ 15,000 cps at 25 ℃,
The second epoxy resin has a viscosity of 65,000 ~ 150,000 cps at 30 ℃,
The third epoxy resin is a car adhesive composition having a viscosity of 300 ~ 1000 cps at 25 ℃. According to claim 1,
The toughening agent is a car adhesive composition having a viscosity of 15,000 ~ 22,000 cps at 50 ℃. According to claim 1,
The first epoxy resin is a bisphenol A type epoxy resin,
The second epoxy resin is at least one resin selected from urethane-modified epoxy resins and CTBN (Carboxyl Terminated Butadiene Acrylonitrile) -modified epoxy resins,
The third epoxy resin is a dimer acid-modified epoxy resin,
The fourth epoxy resin is a bisphenol A type epoxy resin automotive adhesive composition. The method of claim 1, wherein the subject balance
The adhesive composition for automobiles comprising the first epoxy resin, the second epoxy resin, and the third epoxy resin in a weight ratio of 1: 1.4 to 2.1: 0.1 to 0.4. According to claim 1,
The second epoxy resin is urethane-modified epoxy resin and CTBN-modified epoxy resin automotive adhesive composition comprising a weight ratio of 1: 0.05 to 0.3. According to claim 1,
The adhesive composition for automobiles further comprising 4 to 13 parts by weight of a curing agent and 0.5 to 3 parts by weight of a curing accelerator based on 100 parts by weight of the main resin. According to claim 1,
The adhesive composition for automobiles comprising 4 to 13 parts by weight of the hygroscopic agent containing calcium oxide with respect to 100 parts by weight of the main resin. According to claim 1,
The filler is an adhesive composition for a vehicle having two or more types selected from the group consisting of a first filler, a second filler, and a third filler having different shapes. The method of claim 11,
The first filler is a needle-shaped filler having an average particle diameter of 7 ~ 15㎛,
The second filler is a spherical filler having an average particle diameter of 6 ~ 14㎛,
The third filler is an adhesive composition for automobiles, which is a plate-shaped filler having an average particle diameter of 10 to 18㎛. The method of claim 11,
The filler is an automotive adhesive composition comprising the first filler, the second filler and the third filler in a weight ratio of 1: 0.5 to 1.5: 0.5 to 1.5. According to claim 1,
An adhesive composition for automobiles comprising 10 to 20 parts by weight of the filler with respect to 100 parts by weight of the main resin. According to claim 1,
The adhesive composition for automobiles further comprising 0.5 to 3 parts by weight of a strength improving agent and 2.5 to 11 parts by weight of a viscosity modifier based on 100 parts by weight of the main resin.