JPH02228386A - Self-adhesive composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which cures at room temperature and is excellent in both initial adhesion and bonding strength after curing by mixing an epoxy compound, an amine and/or thiol curing agent, and a tackifier. CONSTITUTION:The title composition consists of an epoxy compound (e.g. bisphenol A epoxy compound), an amine and/or thiol curing agent (e.g. Adeka Hardener EH220), and a tackifier (e.g. a styrene/isoprene/styrene block copolymer).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an adhesive composition that can be cured at room temperature and has excellent initial adhesive strength and adhesive strength after curing.

[Prior Art] Epoxy resin adhesives are generally used in a wide range of fields such as the automobile industry because they exhibit good adhesion to various adherends. However, since the epoxy adhesive alone does not have sufficient adhesion before it hardens, it is necessary to hold the bonded area in place (i.e., use a clamp) until the adhesive hardens. In the automobile industry, etc., preheating is performed to shorten this clamping time, which requires equipment and energy.

[Problems to be solved by the invention] The present invention has excellent initial adhesive strength during adhesion, does not require clamping, and exhibits excellent adhesion after curing, which solves the problems of epoxy resin adhesives. The object of the present invention is to provide a pressure-sensitive adhesive composition that can be cured at room temperature and is used to bond metals, plastics, etc., and has simultaneously improved peel strength and impact strength.

[Means for Solving the Problems] That is, the present invention provides an adhesive composition comprising (1) an epoxy compound, (2) an amine-based and/or thiol-based curing agent, and (2) an adhesive.

Various epoxy compounds can be used in the present invention. Examples of such epoxy compounds include condensation products of epichlorohydrin and polyhydric alcohols or polyhydric phenols, condensation products of epichlorohydrin and novolacs such as phenol novolacs and cresol novolacs, cycloaliphatic epoxy compounds, and glycidyl ester-based epoxy compounds. , glycidylamine-based epoxy compounds, heterocyclic epoxy compounds, epoxy compounds derived from polyolefin polymers or copolymers, epoxy compounds obtained by (co)polymerization of glycidyl methacrylate, and glycerides of highly unsaturated fatty acids. Examples include compounds having an epoxy equivalent of about 6,000 or less, such as epoxy compounds, polyalkylene ether type epoxy compounds, and carbon-containing or fluorine-containing epoxy compounds.

The epoxy compound used in the present invention is selected depending on the intended use, but from the viewpoint of general adhesion workability, it is preferable to use one that is liquid at room temperature.

The amine-based and/or thiol-based curing agent used in the present invention is a curing agent that can cure an epoxy compound at room temperature.

As the amine curing agent, various compounds containing at least one primary and/or secondary amino group in the molecule can be used. Such amine curing agents include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine, diethylaminopropylamine, hexamethylenediamine, menthenediamine, isophoronediamine, bis(4-amino-3-methyldicyclohexyl) ) Methane, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, N-aminoethylpiperazine, 3.9-bis(3-aminopropyl)2,4.8
．． 10-tetraoxaspiro(5,5)undecane, m
Examples include aliphatic polyamines such as xylene diamine, and various modified polyamines and polyamide amines that can be obtained manually as commercially available products.

Further, as the thiol curing agent, various compounds containing at least one thiol group in the molecule can be used. Examples of such curing agents include polythiols such as pentaerythritol tetrathioglycolate, trimethylolpropane trithioglycolate, dipentaerythritol hexathioglycolate, and various modified thiols available commercially.

The amount of the amine type and/or thiol type curing agent added is usually 1 to 1 to 100 parts by weight of the epoxy compound.
The amount is 300 parts by weight, and is appropriately selected depending on the combination with the epoxy compound.

Furthermore, a curing accelerator such as tertiary amines may be added to these amine-based and/or thiol-based curing agents.

The adhesive used in the present invention is one that increases initial adhesive strength and imparts impact resistance and peel strength after curing of the adhesive, and may be in the form of rubber or liquid.

Such adhesives include elastomer polymers such as styrene-isoprene-styrene block copolymers and styrene-butadiene-styrene block copolymers (in this case, the elastomer polymers may contain functional groups such as carboxyl groups). ) and rosins, polyterpenes, phenolic resins, petroleum-based hydrocarbon resins, etc., acrylic adhesives made of acrylic esters such as ethyl acrylate, butyl acrylate, etc. Alternatively, vinyl adhesives, silicone adhesives, etc. can be used. The amount of these adhesives used is usually 10 to 100 parts by weight per 100 parts by weight of the epoxy compound and curing agent.
200 parts by weight, preferably 20 to 150 parts by weight,
Particularly preferably 30 to 100 parts by weight. Here, if the amount of the adhesive is less than 10 parts by weight, sufficient initial adhesive strength will not be obtained, and if it is more than 200 parts by weight, the adhesive strength after curing will decrease.

The composition of the present invention can be obtained by, for example, mixing an epoxy compound and an adhesive without using a solvent at 0 to 120°C using, for example, a triple roll, and then mixing a curing agent in a conventional manner. Examples include a method in which the epoxy compound and the adhesive are each made into a solution in toluene or the like, the two are stirred and mixed to remove the solvent, and then the curing agent is mixed in a usual manner.

The composition of the present invention may also contain additives, such as silica, clay, gypsum, calcium carbonate, quartz powder, kaolin, mica, sodium silicate, talc, calcium silicate, titanium compounds, alumina, etc., as necessary. It is possible to incorporate fillers, pigments, surfactants, dispersants and anti-aging agents.

The hardness of the compositions of the invention is achieved under normal conditions at temperatures of 5 to 90°C.

[Example] Examples of the present invention will be described below, but the present invention is not limited thereto. In addition, in the description in the examples, "parts" represent parts by weight.

(1) Example 1.2 ■ Adhesive preparation No. 1: Styrene-isobrene-styrene block copolymer (SIS #5000 manufactured by Honsei Rubber ■)
100 parts and aliphatic hydrocarbon resin (Alcon P-100
(manufactured by Arayo Kagaku Kogyo ■) and 470 parts of toluene were stirred and mixed in a flask to obtain a toluene solution of a rubber adhesive.

99 parts of butyl No. 2 diacrylate and 1 part of acrylic acid were mixed in a flask to obtain an acrylic adhesive.

■ Epoxy compounds and
The toluene solution of the adhesive was mixed with stirring in a flask, and desolubization was performed under reduced pressure while stirring to obtain a mixture of the adhesive and the epoxy compound. In addition, the curing agent and additives were added using Homo Disper (manufactured by Tokushu Kika Kogyo ■) in the proportions shown in Table 1.
Mixed for 0 minutes to obtain a mixture of curing agent and additive.

Next, a mixture of an adhesive and an epoxy compound, and a mixture of a curing agent and an additive were mixed in a flask in the proportions shown in Table 1 to obtain an adhesive composition, and the following tests were conducted. The results are shown in Table-1.

(3) Test method ■ Initial adhesive strength After applying the adhesive composition from one end of a polyvinyl chloride film with an area of 25 x 100 mm and a thickness of 0.2 mm to a 25 x 80 mm area, films of the same shape were bonded together.

Then, it was crimped at 23℃ for 5 minutes at 20kg/cJ.
Immediately use Autograph AG-5000B (manufactured by Shimabara Seisakusho Co., Ltd.) at a tensile speed of 50 n+m/! at 23°C! lin
A 180°C peel test was conducted.

■ Tensile shear strength The material to be bonded is #240 cold rolled steel plate with a thickness of 1.6 mm.
The adhesive composition was polished with sandpaper, washed and degreased with trichlorethylene, and the adhesive composition was cured at 23°C.
It was carried out over 3 days at ℃. The test method is JIS K
According to the method of 6850, the tensile speed was 5 mm/lll1n.
And so.

■ T-type peel strength A cold-rolled steel plate with a thickness of 0.8 mm+ was used for the adherend, and the conditions for surface treatment of the adherend and curing of the adhesive composition were as follows:
It is similar to the tensile shear test. Test method is JIS K6
According to the method of 854, the tensile speed is 50 mad/ak
It was set as in.

■Using impact strength adhesive composition, vertical 100+11! OX horizontal 2
A 5mm x 3.2mm thick cold rolled steel plate was polished with #240 sandpaper! - Using a material that had been washed and degreased with chlorethylene as the adhesive material, it was adhered and cured in the same manner as in (2) with an adhesion area of 25 mg + x 25 an. The obtained adhesive test piece was tested at 23°C using a DuPont impact tester at 100g:
A weight was dropped from a height of 80 cm, and the number of times it took for the bond to break was measured.

Comparative Example 1 An adhesive composition was obtained in the same manner as in Example 1, except that the epoxy compound and the curing agent were not mixed with the adhesive in the proportions shown in Table 1. Next, a test was conducted in the same manner as in Example 1. The results are shown in Table-1.

Example 3.4 Using the homodisper used in Example 1, the epoxy compound and adhesive agent 2 were prepared in the proportions shown in Table 1.
The mixture was mixed and stirred for a minute, and then a curing agent was added to obtain an adhesive composition. Next, a test was conducted in the same manner as in Example 1. The results are shown in Table-1.

Example 5 100 parts of the epoxy compound used in Example 1 and Example 1
40 parts of the styrene-isoprene-styrene block copolymer used in Example 1 and 4 parts of the aliphatic hydrocarbon resin used in Example 1.
0 parts were mixed at 80°C using a triple roll. Further, the curing agents shown in Table 1 were mixed in a flask to obtain an adhesive composition.

Next, a test was conducted in the same manner as in Example 1.

The results are shown in Table-1.

Margins below [Effects of the Invention] The adhesive composition according to the present invention exhibits excellent initial adhesive strength and excellent adhesive strength after curing, and can be used in bonding operations that previously required a clamping process. This allows for simplification.

Patent applicant: Japan Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] An adhesive composition comprising (1) an epoxy compound, (2) an amine-based and/or thiol-based curing agent, and (3) an adhesive.