KR20130048878A - Composition for tape type collisional structural adhesives - Google Patents

Abstract

PURPOSE: A tape type collisional structure adhesive composition is provided to have improved rigidity and impact strength, high durability, and low viscosity; to be used for a laser-welded part; and to be environmentally friendly. CONSTITUTION: A tape type collisional structure adhesive composition comprises 40-84 weight% of an epoxy resin, 9-40 weight% of a filler, 3-10 weight% of an epoxy hardener, 3-8 weight% of an anti-foaming agent, and 0.5-5 weight% of a low temperature curing accelerator. The epoxy resin comprises a mixed resin of bisphenol A type epoxy resin, CTBN-modified epoxy resin, polyurethane-modified epoxy resin, and polyether-modified epoxy resin; and additionally comprises other epoxy resins.

Description

Composition for Tape Type Collisional Structural Adhesives

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an adhesive, which is a structural adhesive mainly composed of an epoxy resin, in particular in the form of a tape, which can be used for laser welding.

Structural adhesives are materials used to bond other high strength materials such as wood, composites or metals. Structural adhesives have been used to replace or reinforce conventional fastening techniques, such as screws, bolts, nails, staples and metal fusion methods such as brazing and brazing, with general use industrial applications. This may further improve the force distribution than joining using alternative techniques such as tightening or welding with rivets. The use of adhesives has the advantage of making the work faster and providing better insulation from external components such as dust or moisture than mechanical techniques. Structural adhesives may be one method for the light weight of mechanical fasteners, particularly in the transportation industry, such as automobiles, aircraft or ships. To be suitable as a structural adhesive, it must have high mechanical strength and impact resistance.

Structural adhesives can be roughly divided into two types: paste adhesives and tape adhesives.

In the bonding of various types of materials, especially metals or metals and composites, for example, welding of automobiles, bonding together with laser welding may have a higher bonding effect. However, in the case of the paste of the structural adhesives, there is a drawback that it is impossible to use the laser welding at the time of welding welding.

Although WO 2008/125521 (October 23, 2008) and WO 2010/011710 (October 28, 2010) refer to the invention for structural adhesives, none of them suggests a collision structural adhesive.

In addition, in order to produce a paste-type adhesive, there is a problem in that it requires a very high cost in terms of economics because of the initial investment in equipment, which is not economical.

Accordingly, the inventors of the present invention have invented a tape-type crash-type structural adhesive that can be used even at a laser welding site and a site that cannot be applied by a robot, in particular, while having a low initial capital investment cost.

Accordingly, the present invention provides an impact-type structural tape adhesive composition comprising an epoxy polymer, a filler, carbon black, a coupling agent, a curing accelerator, and other additives that can be used in a laser welding site.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention, claims and drawings.

According to one aspect of the present invention, the present invention provides a tape-like structural adhesive composition comprising an epoxy resin, a filler, an epoxy curing agent, an anti-foaming agent and a low temperature curing accelerator.

According to another aspect of the present invention, the present invention provides a tape-type impingement structural adhesive comprising the adhesive composition.

Advantages of the present invention are as follows.

(i) In the case of using the adhesive using the tape-type collision type structural adhesive composition of the present invention, the rigidity is increased by improving the vehicle body rigidity and impact resistance, high durability, and low weight of the vehicle body.

(ii) The present invention is characterized by a tape shape, which can be used for laser welding, and is environmentally friendly.

(iii) The tape-like composition of the present invention is very economical in production since the user does not need equipment investment to apply this product.

Hereinafter, the present invention will be described in detail.

According to one aspect of the present invention, the present invention provides a tape-like structural adhesive composition comprising an epoxy resin, a filler, an epoxy curing agent, an anti-foaming agent and a low temperature curing accelerator.

The structural adhesive of this invention contains at least 4 types or more of epoxy resins. The epoxy resin may be a monomeric, dimeric, oligomeric or polymeric epoxy material comprising at least one epoxy functional group. The backbone of the resin can be of any type, and the substituents thereon are any substituents that do not have a nucleophilic group or an electrophilic group to react with the oxirane ring. The molecular weight of the epoxy resin may range from 100 g / mol to 50,000 g / mol or more. Suitable epoxy resins are typically liquid at room temperature, but soluble solid epoxy resins may also be used. The epoxy component includes a mixture of four or more epoxy resins to modify and modify the mechanical properties of the crosslinked structural adhesives for specific requirements.

Epoxy resins usable in the tape-type impingement structural adhesive compositions presented in the present invention include bisphenol A (A) type epoxy resins, butadiene rubber (CTBN) modified epoxy resins substituted with carboxylic acids at the ends, polyurethane modified epoxy resins, and It is characterized in that a mixed resin made of a polyether-modified epoxy resin or an additional epoxy resin is added thereto, and the additionally added epoxy resin is not particularly limited.

The epoxy resin is 40 to 84% by weight of the tape-like structural adhesive composition.

More preferably, the content of the bisphenol A (A) type epoxy resin, the Citibiene (CTBN) modified epoxy resin, the polyurethane modified epoxy resin, and the polyether modified epoxy resin is 3-30% by weight, respectively.

The epoxy curing agent in the structural adhesive of the present invention includes at least one curing agent capable of crosslinking the epoxy resin. Amine curing agents can be used to crosslink the liquid modifier. These are typically primary or secondary amines. The amines may be aliphatic, aromatic or aromatic structures with one or more amino moieties.

Exemplary amine curing agents include ethylene diamine, diethylene diamine, diethylene triamine, triethylenetetramine, propylene diamine, tetraethylene pentamine, hexaethylene hetamine, hexamethylene diamine, 2-methyl-1, 5-pentamethylene-diamine, 4,7,10-trioxatridecane-1,13-diamine, aminoethylpiperazine and the like. And a special latent dicyandiamide as a special curing agent.

The amount of the epoxy curing agent comprises 3-10% by weight of the tape-like structural adhesive composition.

The tape-like structural adhesive composition of the present invention each has a content of 40-84% by weight epoxy resin, 9-40% by weight filler, 3-10% by weight epoxy curing agent, 3-8% by weight anti-forming agent and 0.5 -5% by weight of low temperature curing accelerator.

The filler of the present invention is alone or a mixture thereof from the group consisting of coated calcium carbonate, acicular calcium carbonate, fume silica and calcium carbonate.

Fillers are fillers used to reinforce the properties of materials, to lower costs and to improve processability. Usually, it is divided into two kinds of carbon filler and inorganic filler, and it is added for the purpose of anti-aging, reinforcement and increase. Fillers used in the present invention are coated calcium carbonate, acicular calcium carbonate, fume silica and calcium carbonate, but are not necessarily limited thereto.

Preferred content of the filler comprises 2-10% by weight of coated calcium carbonate, 2-10% by weight of acicular calcium carbonate, 1-6% by weight of fume silica and 4-14% by weight of calcium carbonate.

The present invention further comprises 0.1-0.3 wt% carbon black and 0.1-0.3 wt% coupling agent in the tape-like structural adhesive composition.

Carbon black can be classified according to manufacturing methods as contact black, furnace black, thermal black, and lamp black, and include gas black, oil furnace black, naphthalene black, anthracene black, acetylene black, smoke, leaded black, animal black and vegetable black. Contains raw materials. Small amounts of carbon black may be included in the components of the adhesive and preferably comprise 0.1-0.3% by weight. Carbon black has the purpose of realizing color, weather resistance, and water resistance, as well as improving durability, impact resistance, and adhesion.

The coupling agent is added in small amounts for the purpose of improving the durability of the adhesive and improving the adhesive strength. Preferably 0.1-0.3% by weight.

The anti-forming agent is added for the purpose of removing moisture in the product and applies a wet anti-forming agent, and preferably contains 3.0-8.0% by weight.

The low temperature hardening accelerator is added for the purpose of promoting hardening at low temperature, and applies imidazole and is preferably included in an amount of 0.5-5.0 wt%.

According to another aspect of the present invention, the present invention provides a tape-type impingement structural adhesive comprising the adhesive composition.

By applying the adhesive composition between the two parts to be fastened and curing the adhesive to form a bonded joint, the adhesive composition of the present invention can be used to supplement or completely remove a weld or mechanical fastener. The adhesive composition of the present invention can be used to supplement or completely remove welds or mechanical fasteners. Substrates to which the adhesive of the present invention can be applied include metals such as steel, iron, copper, aluminum and alloys thereof, and include carbon fiber, glass fiber, glass, epoxy fiber composites, wood, and mixtures thereof.

The composition according to the invention can be used as a structural adhesive. In particular, it can be used as a structural adhesive in assembling vehicles such as ships, aircraft or automobiles, motorbikes, and bicycles.

Below. The present invention will be described in detail by examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

Example  1: Components and Contents of Impinging Structural Adhesives

20% of bisphenol A (A) type epoxy resin, 16% of CitiBene (CTBN) modified epoxy resin, 18% of polyurethane modified epoxy resin and 18% of polyether modified epoxy resin were placed in an electric oven and fixed at 110 ° C for 1 hour. After melting, the mixture was stirred for 5 hours and completely melt mixed. The melt was added to the blender and stirred, followed by adding and dispersing carbon black 0.2%, coupling agent 0.1%, coated calcium carbonate 4%, acicular calcium carbonate 4%, fume silica 3%, and calcium carbonate 9% in order for 40 minutes. . Subsequently, 3% of a wet anti-forming agent, 3% of an epoxy curing agent dicyanamide, and 1.7% of a low-temperature curing accelerator imidazole were added thereto, followed by stirring for 10 minutes and vacuuming for 20 minutes. 50 g of this mixture was removed on release paper and cooled at 25 ° C for at least 2 hours. A thin epoxy coated release paper was overlaid on the mixture and pressed with a heating press to create a tape (TAPE) shape. It was then cut to a suitable size.

Example  2 to 5

Prepared in the same manner as in Example 1 and described in Table 1 in the composition content.

The adhesive was produced according to the composition components constituting the tape-type collision type structural adhesive of the present invention in Table 1 below.

Composition component Composition content (%) Example 1 Example 2 Example 3 Example 4 Example 5 Bisphenol A (A) type epoxy resin 20 25 15 10 20 Citibiene (CTBN) modified epoxy resin 16 10 20 22 15 Polyurethane Modified Epoxy Resin 18 25 20 15 16 Polyether Modified Epoxy Resin 18 12 17 25 16 Naphthalene Epoxy Resin - - - - 5 Carbon black 0.2 0.2 0.2 0.2 0.2 Coupling agent 0.1 0.1 0.1 0.1 0.1 Coated calcium carbonate 4 4 4 4 4 Acicular calcium carbonate 4 5 4 4 4 Fume silica 3 2 3 2.6 3 Calcium carbonate 9 11 9 9 9 Anti-forming agents 3 3 3 3 3 Epoxy hardener 3 3 4 3 3 Low temperature curing accelerator 1.7 1.7 2.7 1.3 1.7

Comparative example  1 to 4

Table 2 below describes the components and contents of the compositions of Comparative Examples for comparison with the Examples. In the epoxy polymer, Comparative Example 1 did not add a polyurethane-modified epoxy resin, Comparative Example 2 was a polyether-modified epoxy resin, Comparative Example 3 was a citibiene (CTBN) modified epoxy resin, and Comparative Example 4 was a bisphenol A (A The adhesive which consists of a component which does not add each type of epoxy resin was produced.

Composition component Composition content (%) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Bisphenol A (A) type epoxy resin 24 26 24 - Citibiene (CTBN) modified epoxy resin 24 22 - 22 Polyurethane Modified Epoxy Resin - 24 22 26 Polyether Modified Epoxy Resin 24 - 26 24 Carbon black 0.2 Coupling agent 0.1 Coated calcium carbonate 4 Acicular calcium carbonate 4 Fume silica 3 Calcium carbonate 9 Anti-forming agents 3 Epoxy hardener 3 Low temperature curing accelerator 1.7

Experiment result: Example  1 to 5 and Comparative example  Measuring strength from 1 to 4

Measurement experiments of Examples 1 to 5 and Comparative Examples 1 to 4 were measured by dividing into three items, namely, shear strength, impact strength, and T-Peel strength.

① Shear Strength (Mpa) Test Method

Degrease the 100 × 25 × 1.6 mm steel plate with ISOPROPYL ALCOHOL or toluene, remove the residual solvent with a clean rag after drying and apply this adhesive to one side of the CR and GA steel sheets. And bonded at OVERLAP 12.5 mm. After the bonding part was fixed with a clip (CLIP) (about 0.3 kg of compressive force), it was left to stand at 155 占 폚 for 23 minutes in a standard state of 22 占 폚 and 65% relative humidity after curing. The test pieces were subjected to a tensile load in a 180 degree direction at a tensile speed of 5 mm / min in a tensile tester (Zwick / Roell Z050). Shear strength was determined from the load-displacement curve of the automatic recorder attached to the tensile tester and the average value of three tests was entered.

② Impact Strength (N / m) Test Method

Degreasing a 90 × 20 × 1.6 mm steel sheet with isopropyl alcohol or toluene, drying, removing residual solvent with a clean cloth, and then applying this adhesive to one side of the CR and GA sheet. The other steel plate was joined after apply | coating * 30 mm. The joints were fixed with a clip (CLIP) (about 0.3 kg of compression force), and then left for 1 hour in a standard state of 22 ° C and 65% relative humidity after curing at 155 ° C x 23 minutes. The test piece was subjected to the following conditions using an impact strength tester (INSTRON 9250HV); Impact was by drop weight (45 kg), drop height (0.2 m) and drop speed (2 m / sec). The impact strength value recorded the average value tested three times.

③ T-Peel Strength (N / 25mm) Test Method

Degreasing the 150 × 300 × 0.8 mm steel sheet with ISOPROPYL ALCOHOL or toluene, drying and removing the residual solvent with a clean cloth, and then applying this adhesive to the side of the sheet of CR and GA steel sheets. After application of 220 mm, the other steel sheet was bonded. The joints were fixed with a clip (CLIP) (about 0.3 kg of compression force), and then left for 1 hour in a standard state of 22 ° C and 65% relative humidity after curing at 155 ° C x 23 minutes. The test piece was a tensile tester (Zwick / Roell Z050) was subjected to a tensile load in the direction of 180 mm 50 mm / min tensile speed. T-Peel Strength (N / 25mm) is the average value of 50 mm length after the initial maximum value from the load-displacement curve of the automatic recorder attached to the tensile tester, and the average value tested three times was entered.

Table 3 below describes the values for the three metrics.

Metric Example Comparative example One 2 3 4 5 One 2 3 4 Shear strength (Mpa) CR steel plate 28 27 30 27 28 30 27 23 22 GA grater 25 24 28 23 22 26 22 18 17 Impact strength (N / m) CR steel plate 27 26 30 27 26 19 17 15 23 GA grater 25 24 28 22 20 15 13 12 19 T-peel strength
(T-Peel Strength)
(N / 25mm) CR steel plate 210 208 220 206 200 195 185 170 165 GA grater 160 157 171 156 155 178 136 115 95

Table 4 below describes the physical property ranges, test methods, and specifications for the measurement items.

Test Items Property range Test method and standard Shear strength (Mpa) CR steel plate > 25 Mpa MS 715-60, section 4.2 GA grater > 20 Mpa Impact strength (N / m) CR steel plate > 22 N / m MS 715-60, section 4.3 GA grater > 18 N / m T-peel strength
(T-Peel Strength)
(N / 25mm) CR steel plate > 180 (N / 25mm) MS 715-60, paragraph 4.5 GA grater > 100 (N / 25mm)

In the measurement experiments of Examples 1 to 5 and Comparative Examples 1 to 4, the adhesives of the examples exhibited values above all reference properties for shear strength, impact strength and T-Peel strength, thereby obtaining excellent test measurement results. Could.

However, Comparative Examples 1 and 2 showed values below the physical properties in the impact strength test, and Comparative Examples 3 and 4 were used in all test items for shear strength, impact strength, and T-Peel strength. Measurement results below the physical property range showed very weak results, especially at impact strength.

Claims (10)

Tape-type impingement structural adhesive composition comprising an epoxy resin, a filler, an epoxy curing agent, an anti-foaming agent and a low temperature curing accelerator.
The method of claim 1, wherein the tape-like structural adhesive composition each of the content is 40-84% by weight epoxy resin, 9-40% by weight filler, 3-10% by weight epoxy curing agent, 3-8% by weight anti-forming agent and Adhesive composition, characterized in that 0.5-5% by weight low temperature curing accelerator.
The method of claim 1, wherein the epoxy resin comprises a bisphenol A (A) type epoxy resin, a cithiene (CTBN) modified epoxy resin, a polyurethane modified epoxy resin and a mixed resin consisting of a polyether modified epoxy resin or in addition to other epoxy resins Adhesive composition, characterized in that.
The content of the bisphenol A (A) type epoxy resin, the CitiBene (CTBN) modified epoxy resin, the polyurethane modified epoxy resin, and the polyether modified epoxy resin, which are components of the mixed resin, are 5-30% by weight, respectively. Adhesive composition, characterized in that.
The adhesive composition according to claim 1, wherein the filler is alone or a mixture thereof from the group consisting of calcium carbonate and silica.
The adhesive composition of claim 1, wherein the epoxy curing agent is dicyandiamide.
The adhesive composition of claim 1, wherein the anti-forming agent is a wet anti-forming agent.
The adhesive composition of claim 1, wherein the low temperature curing accelerator is imidazole.
The adhesive composition according to claim 2, further comprising 0.1-0.3 wt% carbon black and 0.1-0.3 wt% coupling agent in the tape-like structural adhesive composition.
Tape-type impingemental structural adhesive comprising the adhesive composition of any one of claims 1 to 8.