JPH07157742A - Aqueous adhesive composition and its production - Google Patents

Abstract

PURPOSE:To provide the two pack type composition comprising a specific composition, useful for members for the interiors of automobiles, excellent in safety on working, free from dangers such as the generation of explosions and fires, and excellent in initial adhesion performance and durability. CONSTITUTION:This composition comprises (A) an anionic ionomer type urethane resin emulsion (e.g. a polyesterpolyol-aromatic diisocyanate copolymer emulsion), (B) an ethylene-vinyl acetate copolymer emulsion containing PVA as a protecting colloid, (C) an adhesivity-imparting agent having a softening point of I260 deg.C (preferably a rosin-modified terpene phenolic resin), (D) a carboxylated styrene-butadiene rubber latex having a glass transition point of <=0 deg.C, and (E) a water-dispersible aliphatic polyisocyanate compound in a compounding ratio (solid content weight ratio) of equations. The composition is obtained by emulsifying the components A-C in water, adding the component D to the emulsion product, and subsequently adding the component E to the obtained main agent emulsion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous adhesive composition used for adhering automobile interior components and a method for producing the same. Specifically, for example, in the adhesion of a polyolefin foam member such as polyethylene foam (PEF) used for a door trim, an instrument panel, etc. to a plastic member or a wood member, excellent initial adhesion performance and durability performance are expressed. 2 The present invention relates to a liquid type aqueous adhesive composition and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, when a skin material such as a polyolefin foam member used for manufacturing the above-mentioned automobile interior member such as a door trim or an instrument panel is adhered to a base material such as plastic or a wood member, it is generally used. A solvent-based adhesive such as a polyester polyurethane rubber solvent-based adhesive is used. That is, an adhesive work is generally performed in which this solvent-type adhesive is applied to the base material side, dried, and then a preheated skin material is laminated and pressed.

[0003]

However, when this solvent-based adhesive is used, a large amount of the solvent is volatilized during the coating work or the drying process, which may cause problems for workers' occupational safety and health, or may cause explosion or fire. There is a problem that the risk of such a disaster is high. Therefore, recently, application of a water-based adhesive instead of the solvent-based adhesive has been studied. As such a water-based adhesive, JP-A-56-80451 is known.
Japanese Patent Laid-Open Publication No. 63-126981, Japanese Patent Laid-Open Publication No. Hei 4-
An aqueous adhesive composition as disclosed in 293986 can be mentioned. However, these water-based adhesive compositions have characteristics of both initial adhesion performance (material destruction rate, heat creep resistance) and durability performance (moisture heat aging resistance, heat aging resistance) as compared with solvent-type adhesives. Have the problem of not being satisfied at the same time. Therefore, the above-mentioned water-based adhesive composition has not been put into practical use because of lack of practicality.

The present invention has been made in view of the above circumstances, and is excellent in safety during work, has no risk of accident such as explosion and fire, and has the same or better initial stage than solvent-based adhesives. An object is to provide an aqueous adhesive composition having adhesiveness and durability and a method for producing the same.

In order to achieve the above object, the first aspect of the present invention is an aqueous adhesive composition containing the following components (A) to (E). (A) Anionic ionomer type urethane resin emulsion. (B) An ethylene-vinyl acetate copolymer resin emulsion using polyvinyl alcohol as a protective colloid. (C) A tackifier having a softening point of 60 ° C. or higher. (D) Carboxylated styrene-butadiene rubber latex having a glass transition point of 0 ° C. or lower. (E) Water-dispersible aliphatic polyisocyanate compound. However, the blending ratio (solid content weight ratio) of the components (A) to (E) is as follows: A / B = 80/20 to 30/70, C / (A + B) = 10/100 to 50/100, D / (A + B) = 10/100 to 50/100, E / (A + B + C + D) = 2/100 to 20/100. And (A)-
The component (C) is emulsified in water to prepare a tackifying emulsion, and the following component (D) is added to this to prepare a main agent emulsion.
A second gist is a method for producing an aqueous adhesive composition containing the components. (A) Anionic ionomer type urethane resin emulsion. (B) An ethylene-vinyl acetate copolymer resin emulsion using polyvinyl alcohol as a protective colloid. (C) A tackifier having a softening point of 60 ° C. or higher. (D) Carboxylated styrene-butadiene rubber latex having a glass transition point of 0 ° C. or lower. (E) Water-dispersible aliphatic polyisocyanate compound. However, the blending ratio (solid content weight ratio) of the components (A) to (E) is as follows: A / B = 80/20 to 30/70, C / (A + B) = 10/100 to 50/100, D / (A + B) = 10/100 to 50/100, E / (A + B + C + D) = 2/100 to 20/100.

[0006]

In other words, in order to solve the above-mentioned problems, the present inventors have made extensive studies on each component of the adhesive composition and its mixing ratio. As a result, when an aqueous adhesive composition is prepared with the above components and blending ratio, the properties of each component can be brought out well, and the resulting aqueous adhesive composition may have excellent initial adhesion performance and durability performance. The inventors have reached the present invention. According to the present invention, it is possible to provide a water-based adhesive composition that is excellent in safety and has no risk of disaster occurrence and that has performance equivalent to or higher than that of a solvent-based adhesive.

Next, the present invention will be described in detail.

The aqueous adhesive composition of the present invention comprises an anionic ionomer type urethane resin emulsion (component A),
Ethylene-vinyl acetate copolymer resin emulsion (component B) using a specific protective colloid, tackifier (component C) having a softening point of 60 ° C or higher, carboxylated styrene-butadiene having a glass transition point of 0 ° C or less. A rubber latex (component D) and a water-dispersible aliphatic polyisocyanate compound (component E) can be used to prepare the following.

That is, first, a tackifying emulsion is prepared using the components A to C.

The anionic ionomer type urethane resin emulsion (hereinafter abbreviated as "urethane resin emulsion") which is the component A is triethylamine in a urethane resin having a functional group such as a sulfone group or a carboxyl group introduced into its main chain or side chain. It can be obtained by adding a basic substance such as and emulsifying in water. This is a so-called soap-free type resin emulsion. Specific examples thereof include urethane resin emulsions such as polyester polyol-aromatic diisocyanate copolymer emulsion (Highland HW301, manufactured by Dainippon Ink and Chemicals, Inc.).

Further, the ethylene-vinyl acetate copolymer resin emulsion as the component B uses polyvinyl alcohol as a protective colloid. This copolymer resin emulsion can be prepared by emulsion-polymerizing ethylene and a vinyl acetate monomer in the presence of polyvinyl alcohol. For the above emulsion polymerization, a conventional emulsion polymerization method can be applied. As such an ethylene-vinyl acetate copolymer resin emulsion using polyvinyl alcohol as a protective colloid, an ethylene-vinyl acetate copolymer resin emulsion (Sumika Flex 4
00, manufactured by Sumitomo Chemical Co., Ltd.) and the like. Further, it is preferable to use one having an ethylene content in the range of 10 to 40% by weight. The vinyl acetate-based monomer to be copolymerized with ethylene includes vinyl acetate which is usually used, and a part of vinyl acetate is (f) and (g) shown below in an amount of 10% based on the whole vinyl acetate. It is also possible to use a substitute in the range of ˜50% by weight. (F) Copolymerizable monomers such as acrylic acid ester, methacrylic acid ester and vinyl chloride. (G) A functional group-containing vinyl monomer having a carboxyl group, an epoxy group, a sulfone group, a hydroxyl group, a methylol group, an alkoxyl group, an acid group or the like.

The urethane resin emulsion (component A)
And ethylene-vinyl acetate copolymer resin emulsion (B
The mixing ratio (solid content weight ratio) of the component) is A / B = 80 /
20 to 30/70, preferably 65/35 to 4
The ratio is set to 5/55. That is, when the proportion of the urethane resin emulsion (A component) exceeds 80 [B component is less than 20], the wet heat aging resistance tends to decrease in the durability performance. It is considered that this is due to hydrolysis of the urethane resin. On the contrary, when the ratio of the ethylene-vinyl acetate copolymer resin emulsion (component B) exceeds 70 [A component is less than 30], the initial tackiness tends to be low and the adhesion to the skin material tends to be poor. This is because the initial adhesion performance is not expressed.

As the tackifier as the C component, rosin such as rosin, rosin ester, polymerized rosin and disproportionated rosin, C ₅ resin, C ₉ resin, C ₅ · C ₉
A resin such as a petroleum resin based resin, a terpene resin, a terpene phenolic resin, or a terpene phenolic resin such as a rosin-modified terpene phenolic resin having a softening point of 60 ° C. or higher is used. Among these, terpene phenol resin,
Preference is given to using rosin-modified terpene phenolic resins. Particularly preferred is rosin-modified terpene phenol resin (Tamanol 803, manufactured by Arakawa Chemical Industry Co., Ltd.). Further, the softening point is limited to 60 ° C. or higher because it cannot be used if the softening point is lower than 60 ° C. because it has poor heat-resistant creep resistance. Then, when the tackifying emulsion is prepared, the one obtained by emulsifying the tackifying agent by a usual method is used. Examples of the emulsified product include the emulsified product of the rosin-modified terpene phenol resin (Tamanol E100, manufactured by Arakawa Chemical Industry Co., Ltd.).

The tackifying agent (C component) is mixed in a solid content weight ratio of the above A component and B component in a total of 1%.
1 to 100 parts by weight [abbreviated as “part” below] (A + B)
It is set in the range of 0 to 50 parts, preferably in the range of 20 to 40 parts. That is, when the amount is out of the above range of 10 to 50 parts, the heat-resistant creep property of the obtained adhesive composition tends to decrease, and both the heat aging resistance and the wet heat aging resistance tend to decrease. .

A tackifying emulsion can be prepared by emulsifying the components A to C in water. The emulsification method at this time is not particularly limited, and a usual method such as an inversion emulsification method is applied. Further, the mixing ratio of water is 100 in total of the A component and the B component.
It is in the range of 10 to 50 parts, preferably in the range of 20 to 40 parts, relative to parts (weight of solid content).

Next, the tackifying emulsion (A
By blending + B + C) with carboxylated styrene-butadiene rubber latex [hereinafter referred to as “carboxylated SBR latex”] (component D), an emulsion which is the main component of the adhesive composition can be prepared. This carboxylated SBR latex is obtained by emulsion polymerization of styrene, butadiene, and a carboxyl group-containing monomer by a known method. The carboxylated SBR latex has a glass transition point (T
It is necessary to use those whose g) is 0 ° C. or lower. Examples of such a material include styrene-butadiene-methacrylic acid copolymer emulsion (Nipol LX472, manufactured by Zeon Corporation) and the like.

The carboxylated SBR latex (D
The mixing ratio (solid content weight ratio) of the component) is 10 to 5 with respect to the total 100 parts (A + B) of the component A and the component B.
The range is 0 part, preferably 20 to 40 parts. That is, if the amount is less than 10 parts, the initial adhesion performance tends not to be exhibited, and conversely, if it exceeds 50 parts, the heat aging resistance of the durability performance tends to decrease.

Then, the main agent emulsion (A + B +
By mixing C + D) with a water-dispersible aliphatic polyisocyanate compound (E component) as a curing agent, the desired aqueous adhesive composition can be obtained. This water-dispersible aliphatic polyisocyanate is, for example, one obtained by modifying a trimer of an aliphatic isocyanate by a method such as addition reaction of polyethylene oxide having a hydroxyl group at one end to make it water-dispersible (JP-A-61-161). No. 291613). Specifically, a modified product of hexamethylene diisocyanate oligomer (SBU isocyanate 077
2, Sumitomo Bayer Urethane Co.). By blending this curing agent, the heat resistance and durability of the resulting water-based adhesive composition will be improved, and it will be practical.

The mixing ratio of the water-dispersible aliphatic polyisocyanate (component E) is such that the base emulsion (A +
(B + C + D) 100 parts, the range is 2 to 20 parts, preferably 5 to 15 parts. That is, if the blending amount is less than 2 parts, it tends to be impossible to sufficiently obtain the characteristics of heat creep resistance and durability.
On the other hand, if it exceeds 20 parts, the pot life at the time of blending and mixing with the main agent emulsion is shortened, and the adhesion work tends to be disturbed.

In this way, the aqueous adhesive composition of the present invention can be prepared. In addition to the above A to E components, other additives generally used in water-based adhesives and the like, such as thickeners, solvents, plasticizers, wetting agents, and fillers, may be added as necessary. It is possible.

[0021]

As described above, in the water-based adhesive composition of the present invention, the specific components A to E are blended in the specific proportions so that the characteristics of each component can be brought out well. . By doing so, it becomes possible to simultaneously satisfy two properties, which cannot be achieved by the conventional water-based adhesive composition, that is, the initial adhesion performance and the durability performance. Therefore, the water-based adhesive composition of the present invention has the same or higher performance as the solvent-type adhesive, and can be used for adhesion of automobile interior members instead of the conventional solvent-type adhesive. become able to. Further, since the adhesive composition of the present invention is aqueous, there is no problem of solvent volatilization. Therefore, in the work of adhering the automobile interior member, there is no influence on the safety to the human body of an operator or the like, and there is no problem of explosion or ignition. And, conventionally, it was necessary to provide various equipment for the safety and health of workers and the prevention of disasters, but by applying the present invention, it is not necessary to provide such equipment, so that the equipment cost can be kept low. Become. The method for producing the water-based adhesive composition of the present invention can be carried out by an ordinary emulsification method or the like, and is a simple method, so that it can be easily carried out.

Next, examples will be described together with comparative examples.

Prior to the examples and comparative examples, the raw materials A to E shown in Table 1 below were prepared.

[0024]

[Table 1]

[0025]

Examples 1 to 15 and Comparative Examples 1 to 8 The above raw materials were mixed in the proportions shown in Tables 2 to 6 below, and water-based adhesive compositions were prepared by the above method.

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

[0030]

[Table 6]

Example products 1 to 1 thus obtained
5, the initial adhesive performance, durability performance and pot life of the water-based adhesive compositions of Comparative Example products 1 to 8 were evaluated. The results are shown in Tables 7 to 11 below. The above characteristics were evaluated by the following methods.

[Initial Adhesion Performance] The initial adhesion performance was evaluated by conducting two tests of material fracture rate and heat resistant creep. That is, first, an adhesive composition was applied on an acrylonitrile-butadiene-styrene copolymer (ABS) base material (manufactured by Sumitomo Nogatac Co., Ltd.) at a rate of 80 g / m ² and kept in a constant temperature bath at 50 ° C. for 7 minutes. Dried. This is adhered to a skin material (polyolefin foam, manufactured by Tatsuta Co., Ltd.) that has been heated to 150 ° C. in advance, and a press machine is used to 40
° C., and pressing for 30 seconds at a pressure of 0.5 kg / cm ^2. Immediately after pressing, the skin material was forcibly peeled off. The ratio of the fracture area of the skin material to the peeled area at this time was defined as the material destruction rate (%). On the other hand, a heat-resistant creep test was carried out after curing the above-mentioned ABS base material and skin material bonded in a constant temperature bath at 40 ° C. for 30 minutes. This creep test is 25m
A load of 200 g is applied to a test piece molded into a width of m, and the temperature is 80 ° C.
Peeling length [creep length] after leaving for 30 minutes in a constant temperature bath (m
m) was measured.

[Durability] A test sample (adhesive) was prepared in the same manner as in the above measurement of the initial adhesion performance. Then, one set of two test samples is set at room temperature.
I was cured. Then, one of the test samples was left to stand in a thermo-hygrostat at 50 ° C. and 95% RH for 1000 hours. The other one was left in a constant temperature bath at 110 ° C. for 1500 hours. After standing, the skin material was forcibly peeled off in a 100 ° C. thermostat, and the durability performance was evaluated by the ratio of the fracture area of the skin material to the peeled area at this time. That is, 10
The one that was left for 00 hours was subjected to a moisture heat aging test, and the one that was left for 1500 hours was referred to as a heat aging test.
%: ○, 70% or more but less than 100%: △, 7
Those less than 0% were represented by x.

[Pot life] In the preparation of the aqueous adhesive composition, the main agent emulsion was mixed with the curing agent (component E) and then left at 30 ° C. for 4 hours. Then, using this adhesive composition, the same creep resistance test as in the above-mentioned initial adhesive performance evaluation method was conducted. At that time, the peeling length (creep length) of 10 mm or less is represented by O, and the peeling length of 11 mm or more is represented by X.

[0035]

[Table 7]

[0036]

[Table 8]

[0037]

[Table 9]

[0038]

[Table 10]

[0039]

[Table 11]

From Tables 7 to 9 described above, it can be seen that the water-based adhesive compositions of Examples are excellent in all properties such as initial adhesion performance, durability performance and pot life. On the other hand, from Tables 10 and 11, the water-based adhesive compositions of Comparative Examples have the compounding ratios of the respective components deviating from the appropriate values,
None of them satisfied all the characteristics of initial adhesion performance, durability performance and pot life.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuya Oda 1-4-1 Chuo, Wako-shi, Saitama, Ltd. Honda R & D Co., Ltd. No. 6-9 No. 405 (72) Inventor Hideki Tawada 3-7-46, Senba Nishi, Minoh City, Osaka Prefecture

Claims (2)

[Claims] 1. A water-based adhesive composition comprising the following components (A) to (E). (A) Anionic ionomer type urethane resin emulsion. (B) An ethylene-vinyl acetate copolymer resin emulsion using polyvinyl alcohol as a protective colloid. (C) A tackifier having a softening point of 60 ° C. or higher. (D) Carboxylated styrene-butadiene rubber latex having a glass transition point of 0 ° C. or lower. (E) Water-dispersible aliphatic polyisocyanate compound. However, the blending ratio (solid content weight ratio) of the components (A) to (E) is as follows: A / B = 80/20 to 30/70, C / (A + B) = 10/100 to 50/100, D / (A + B) = 10/100 to 50/100, E / (A + B + C + D) = 2/100 to 20/100. 2. The following components (A) to (C) are emulsified in water to prepare a tackifying emulsion, and the following component (D) is added to this to prepare a main agent emulsion. A method for producing an aqueous adhesive composition, characterized in that the following component (E) is added. (A) Anionic ionomer type urethane resin emulsion. (B) An ethylene-vinyl acetate copolymer resin emulsion using polyvinyl alcohol as a protective colloid. (C) A tackifier having a softening point of 60 ° C. or higher. (D) Carboxylated styrene-butadiene rubber latex having a glass transition point of 0 ° C. or lower. (E) Water-dispersible aliphatic polyisocyanate compound. However, the blending ratio (solid content weight ratio) of the components (A) to (E) is as follows: A / B = 80/20 to 30/70, C / (A + B) = 10/100 to 50/100, D / (A + B) = 10/100 to 50/100, E / (A + B + C + D) = 2/100 to 20/100.