JPH08109271A - Method for bonding surface material - Google Patents

Abstract

PURPOSE: To obtain a method for bonding a surface material having a foam layer pretreated with a primer to an ABS substrate while overcoming the peeling stress caused by the complicated shape of the substrate by coating either the surface material or the substrate with a specific two-component water-base adhesive, drying the adhesive, placing the surface material in a heated state on the substrate, and bonding and forming the surface material in a vacuum. CONSTITUTION: A surface material is bonded to a substrate by a vacuum- forming method using a two-component water-base adhesive. The adhesive comprises the main component comprising a polycarbonate-urethane emulsion, a water-base ethylene-vinyl acetate copolymer emulsion, and a water-base tackifying resin emulsion and the curative comprising a polyurethane prepolymer obtd. by reacting an excess amt. of an aliph. polyisocyanate with a polyether polyol. The polycarbonate-urethane emulsion is obtd. by reacting a carbonate diol. a chain extender of the formula (wherein R is H or 1-3C alkyl), and a polyisocyanate compd. and subjecting the resulting carboxyl-contg. hydroxyl- terminated polyurethane to self-emulsification in water in the presence of a tert. amine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adhering a skin material, and more specifically, to an acrylonitrile / butadiene / styrene copolymer (hereinafter referred to as ABS) used for automobile interior parts.
In the method of bonding the base material and the skin material by a vacuum forming method, by using a two-component water-based adhesive that is active at a low temperature and is crosslinkable, the peeling stress of the skin material due to the complicated shape of the base material The present invention relates to an adhesion method capable of imparting a so-called high durability, high initial cohesive force type molded article having sufficient durability and high durability (heat resistance, moisture resistance) required for automobile interior parts.

[0002]

2. Description of the Related Art Conventionally, ABS has been used as a base material for automobile interior parts panels.
Then, for example, a polyolefin foam having a foam layer is used as a skin material, and a vacuum forming method is generally widely used as a method for adhering the ABS substrate and the skin material.
Such a vacuum forming method is performed by, for example, applying an adhesive to an ABS base material and then drawing a skin material (having an adhesive surface subjected to a primer treatment in advance) heated to a moldable temperature to the ABS base material side in a vacuum state. It is a construction method in which molding and adhesion are performed simultaneously.

In this method, however, a two-component solvent type polyester urethane-based or chloroprene-based adhesive having a polyisocyanate compound as a curing agent is used as an adhesive, but this is a problem of environmental pollution due to the use of an organic solvent. However, switching to an aqueous adhesive containing the organic solvent at all or only in a small amount is under study. Under these circumstances, it has been attempted to use a two-component aqueous adhesive in which a polyester polyurethane-based aqueous emulsion as a main component is combined with a curing agent of a polyisocyanate compound.
Automotive interior parts, especially low-temperature activation in the instrument panel requirements (especially the appearance quality after molding can suppress luster and squeezing, which is also advantageous in terms of energy saving and work safety) and high initial heat resistance , High durability can not be satisfied.

[0004]

Means for Solving the Problems Accordingly, the present inventors have:
In the method of adhering a skin material on such an ABS substrate panel, as a result of intensive research to provide a method for satisfying the performance as an automobile interior part, it is known as a component of a coating agent or a fiber treatment agent. Polycarbonate / urethane emulsions, which have poor properties and are self-emulsified in water in the presence of a tertiary amine, by introducing a polycarbonate diol and a chain extender containing a carboxyl group, and ethylene-vinyl acetate copolymer aqueous emulsion and tackifier resin aqueous solution. If you use a two-component water-based adhesive that uses a mixture of emulsion as the main agent and a specific polyurethane prepolymer as the curing agent,
Based on the low-temperature activity and cross-linking curability, the inventors have found that the intended purpose can be achieved, and have completed the present invention.

That is, the present invention relates to an ABS substrate,
In adhering the skin material having the foam layer by the vacuum forming method,
A two-component water-based adhesive is applied to either one of the ABS base material or the skin material whose adhesive surface has been treated with a primer, and after drying, the heated skin material is overlaid on the ABS base material and adhesively molded in a vacuum state. In the method, the two-component water-based adhesive has the formula (a) carbonate diol and the formula:

Embedded image A terminal hydroxyl group-containing polyurethane having a carboxyl group obtained by reacting a carboxyl group-containing chain extender (wherein R is hydrogen or a linear or branched alkyl group having 1 to 3 carbon atoms) with a polyisocyanate compound Polymer, self-emulsifying in water in the presence of a tertiary amine, a polycarbonate-urethane emulsion, (b) an ethylene-vinyl acetate copolymer aqueous emulsion and (c) a tackifier resin aqueous emulsion as a main component, and an excess amount of fat. A method for adhering a skin material having a foamed layer to an ABS substrate by a vacuum forming method, which comprises a curing agent composed of a polyurethane prepolymer which is a reaction product of a group-based polyisocyanate and a polyether polyol Is.

The above polycarbonate / urethane emulsion (a) used in the present invention can be produced by the following procedure. That is, carbonate diol (usually
A number average molecular weight of 500 to 3000), a carboxyl group-containing chain extender of the above formula [I] (for example, dimethylolpropionic acid (DMPA), dimethylolbutanoic acid, dimethylolpentanoic acid, etc.) and a polyisocyanate compound (for example, hexamethylene diisocyanate). Aliphatic polyisocyanates such as 2,2,4-trimethylhexamethylene diisocyanate; Isophorone diisocyanate, hydrogenated xylylene diisocyanate, alicyclic polyisocyanates such as 4,4-cyclohexylmethane diisocyanate; xylylene diisocyanate, tetramethyl Aromatic aliphatic polyisocyanate such as xylylene diisocyanate; toluene diisocyanate, aromatic polyisocyanate such as diphenylmethane diisocyanate), if necessary, a suitable organic solvent ( For example, methyl ethyl ketone, ethyl acetate, toluene, dimethylformamide, N-methylpyrrolidone, methyl isobutyl ketone,
Or a mixture thereof or the like) at 60 to 120 ° C. for 2 to 8 hours to obtain a terminal hydroxyl group-containing polyurethane polymer having a carboxyl group. In the reaction, the ratio of the carboxyl group-containing chain extender [I] may be selected in a ratio of 1.0 to 3.0 mol with respect to 1 mol of the carbonate diol. Further, the ratio of the polyisocyanate compound may be selected in such a ratio that it is 0.5 mol or more and less than 1 mol per 1 mol of the total of the carbonate diol and the carboxyl group-containing chain extender. As other chain extenders, for example, diols such as 1,2-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, ethylbutylpropanediol and the like are used in an amount of 2. You may add in the range of 5 mol or less. However, in this case, it is also necessary to appropriately add a polyisocyanate compound.

Next, the terminal hydroxyl group-containing polyurethane polymer having a carboxyl group (as it is when it is obtained in a solution state) is neutralized with a tertiary amine and then self-emulsified in water. By removing the organic solvent by a conventional method, a polycarbonate / urethane emulsion having a solid content of 25 to 50% is obtained. The tertiary amine has the formula:

Embedded image (In the formula, R ₁ , R ₂ and R ₃ are the same or different and are linear or branched alkyl having 1 to 4 carbon atoms, — (CH ₂ ) n
_{-OH, - (CH 2 O)} m-H, - (CH 2 CH 2 O) m-H,

[Chemical 4] _{, - ((CH 2) l} -O) m-H, n is 1 to 4, m is 2 to 5, l is indicated by a 2 to 5), such as triethylamine,
Triethanolamine, dimethylethanolamine, diethylethanolamine, dibutylethanolamine,
Aminoethoxyethanolamine, methylethanolamine, ethylethanolamine, N-ethylmorpholine, dimethylaminoethoxyethanol and the like can be mentioned. The degree of neutralization is 0.5 to 2.5 with respect to COOH of the terminal hydroxyl group-containing polyurethane polymer having a carboxyl group.
It may be selected so as to be equivalent.

The ethylene-vinyl acetate copolymer aqueous emulsion (b) used in the present invention includes ethylene and vinyl acetate, or ethylene and vinyl acetate and other copolymerizable monomers (eg acrylic acid and its derivatives, methacrylic acid). Acid and its derivatives, various vinyl compounds, maleic anhydride, etc.) are emulsion-polymerized in water, and usually have a solid content of 30 to 55% and a glass transition point (Tg) of 20 to 20.
It is sufficient to use the one at + 20 ° C. The ethylene copolymerization content is preferably 5 to 40 mol%, and when other copolymerizable monomers are included, the content is preferably set to 0.1 to 10 mol%.
The amount used (in terms of solid content) is usually the above-mentioned polycarbonate
Solid content of urethane emulsion (a) 100 parts (parts by weight,
The same shall apply hereinafter) may be selected in the range of 5 to 1000 parts. If it is less than 5 parts, the initial creep property will not be exhibited, and if it exceeds 1000 parts, the heat resistance and durability tend to be lowered.

The tackifying resin aqueous emulsion (c) used in the present invention means various tackifying resins (for example, rosin acid, rosin acid ester, C ₅ petroleum resin, C ₉ petroleum resin, coumarone indene resin and waters thereof). (Addition, imbalance, partially hydrogenated modified product, etc.) in an organic solvent solution in the presence of an anionic or nonionic emulsifier, and self-emulsified, and then the solvent is removed. % May be used. The amount used (in terms of solid content) is usually
It may be selected in the range of 1 to 50 parts based on 100 parts of the solid content of the polycarbonate / urethane emulsion (a). If it is less than 1 part, the initial low temperature adhesion cannot be obtained, and if it exceeds 50 parts, the heat resistance and durability tend to be lowered.

The above-mentioned polyurethane prepolymer used as a curing agent in the present invention is an excess amount of an aliphatic polyisocyanate (eg hexamethylene diisocyanate, 2,
Designates the reaction product of 2,4- or 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, etc.) and polyether polyol (eg polyoxyalkylene polyol, modified polyether polyol, polytetramethylene ether glycol, etc.) Then
Usually, those having an NCO group content of 10 to 30% may be used.

The two-component water-based adhesive used in the present invention is a polycarbonate / urethane emulsion in the above-mentioned predetermined ratio.
(a), a main component consisting of an ethylene-vinyl acetate copolymer aqueous emulsion (b) and a tackifying resin aqueous emulsion (c), and a two-component type of a polyurethane prepolymer curing agent. Meter in the hardener. If necessary, other base emulsions (eg acrylic, styrene-butadiene rubber (SBR))
System, acrylonitrile-butadiene rubber (NBR) system,
Chlorinated polypropylene type, chlorinated rubber type, polyester type anionic or nonionic aqueous emulsion), thickener (eg acrylic type, urethane type, polyvinyl alcohol type), latent crosslinking agent (eg epoxy type, oxazoline type, carbodiimide type) , Melamine-based, blocked polyisocyanate-based), emulsifiers, protective colloids, preservatives, other antiaging agents, film-forming aids, antifreezing agents, dyes and pigments, etc. may be blended in appropriate amounts. The pH of the base compound can be adjusted within the range of usually 4 to 10 with the tertiary amine or aqueous ammonia used for neutralization in the production of the urethane emulsion (a). The amount of the curing agent used is usually selected in the range of 3 to 10% by weight based on the total amount of the main component.

The method for adhering the skin material according to the present invention is characterized by using the above-mentioned two-component water-based adhesive, and can be carried out in accordance with the conventional vacuum forming method. First, ABS
An adhesive surface of a skin material (for example, polyethylene foam or polypropylene foam) having a foamed layer, which is adhered to a base material, is previously subjected to a primer treatment with, for example, a urethane-based primer (polyester resin / polyisocyanate solvent solution). Next, the two-component water-based adhesive is usually applied in an amount of ^{20 to} 150 g / m ² on either the surface of the ABS substrate or the primer-bonded surface of the skin material, and then 40 to 80 ° C. After drying for 5 to 30 minutes at
The adhesive molding is completed by superimposing a skin material heated to a moldable temperature (usually 100 to 180 ° C.) on the BS base material and drawing it into the ABS base material side in a vacuum state.

[0013]

According to the bonding method of the present invention having the above-mentioned constitution, by using the two-component aqueous adhesive which is active at low temperature and is crosslinkable and curable, the low temperature bonding and the initial heat resistance corresponding to the vacuum molding method, In addition, it can exhibit the durability of automobile interior parts, particularly instrument panel requirements, and at the same time contributes to environmental improvement.

[0014]

[Examples] Next, reference examples, examples and comparative examples will be given.
The present invention will be described more specifically. Reference Example 1 Production of two-component water-based adhesive :-( 1) Polycarbonate / urethane emulsion Polycarbonate diol having a number average molecular weight of 2000 (Toagosei Co., Ltd., D-2000, OH value = 57.4) 20
Dissolve 0 g in 400 g of methyl ethyl ketone, and add DMPA2
After adding 0.1 g and stirring at 60 ° C., 35 g of hexamethylene diisocyanate was added and the temperature was raised to 80 ° C.
React at 24 hours for 24 hours. The reaction solution of the obtained terminal hydroxyl group-containing polyurethane polymer having a carboxyl group is cooled to 60 ° C., 12.1 g of triethylamine is added for neutralization, and 300 g of distilled water is added to self-emulsify the mixture for water dispersion. The dispersion was desolvated using an evaporator to obtain a polycarbonate with a solid content of 45%.
Obtain a urethane emulsion.

(2) Main agent The polycarbonate / urethane emulsion of (1) above was used, and the following parts were added to each of the ingredients.
The pH is adjusted to 7.5 with aqueous ammonia and used as the main agent. Component portion polycarbonate urethane emulsion (solid content 45%) --- 100 Ethylene - vinyl acetate copolymer aqueous emulsion (manufactured by Kuraray Co., Ltd., OM-6 000, solid content 50%, Tg6 ℃) --- 50 SBR latex (Nippon Synthetic Rubber Co., Ltd., 0700, solid content 57%) --- 0.7 rosin ester aqueous emulsion (Arakawa Chemical Co., E-650, solid content 50%) --- 5 Petroleum resin aqueous emulsion ( Nippon Oil Co., Ltd., 700E, solid content 50%) --- 5 Melamine-based latent cross-linking agent (Dainippon Ink and Chemicals Co., Ltd., Super Beckamine L-127-60) --- 5 Film formation Auxiliary agent (Kuraray Co., Ltd., PMG) ---- 1

(3) Hardener Polyether diol (PR-1007, manufactured by ADEKA CORPORATION) 1
After degassing 00 g under reduced pressure at 100 ° C., hexamethylene diisocyanate (Sumijour H-, manufactured by Sumitomo Bayer Co., Ltd.)
S) (65 g) is added and the mixture is reacted at 90 ° C. for 8 hours to obtain a polyurethane prepolymer having an NCO group content of 13%. (4) Two-component water-based adhesive The above-mentioned main agent (2) and the curing agent (3) are stirred and mixed at a weight ratio of 100/5 to obtain a two-component water-based adhesive.

Example 1 ABS substrate (Sumitomo Dow, ABS K-2938FS)
The coating amount of the two-component water-based adhesive produced in Reference Example 1 was 50
Apply with a bar coater to g / m ² and 50 ℃ ×
After drying for 7.5 minutes, polypropylene foam with a primer (urethane type) (PPX manufactured by Toray Industries, Inc.), which had been heated to a surface temperature of 140 ° C. in advance, was pressure bonded for 30 seconds at a pressure of 0.5 kg / cm ^2. To prepare a test piece. Then, the following test items were used, and the results are shown in Table 1.

Immediately after the initial creep bonding, 200 g load, 40 ° C x 30 minutes + 80 ° C x 3
After bonding 90 ° angle creep heat resistant creep after 0 minutes, leave at 20 ° C, 65% RH for 24 hours,
100g load in 100 ℃ atmosphere, 90 after 24 hours
° After heat-peeling after corner creep endurance, aged at 20 ° C and 65% RH for 24 hours,
Then, after leaving it under the following conditions, 180 ° angle hot peel strength in 100 ° C atmosphere Heat aging: 110 ° C × 1500 hours left Moisture heat aging: 50 ° C, 95% RH × 500 hours left

Comparative Example 1 100 g of a polyester polyurethane aqueous emulsion (R-9621 manufactured by Zeneca, solid content 30%) was added to an ethylene-vinyl acetate copolymer aqueous emulsion (EVA Tex 63 manufactured by Denki Kagaku, solid content 60%). 80 g and terpene phenol emulsion (Arakawa Chemical Co., E-
101) After mixing 10 g, a thickener (San Nopco Ltd.)
Manufactured by San Nopco A-814) (2 g) and added as the main ingredient. A water-dispersible polyisocyanate compound (0772, manufactured by Sumitomo Bayer Co., Ltd.) as a curing agent was mixed with this base resin at a weight ratio of 100/5 to obtain a two-component water-based adhesive, which was subjected to the same adhesion test as in Example 1. The results are also shown in Table 1.

[0020]

[Table 1]

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location C09J 175/04 JFB (72) Inventor Keiichi Honjo 1-4-1 Chuo Wako, Saitama Prefecture Stock Association (72) Inventor Masaki Ukai 7-1 Akita-cho, Takatsuki-shi, Osaka Prefecture Sunstar Giken Co., Ltd. (72) Inventor Kiyoshi Nakayama 7-1 Akita-cho, Takatsuki-shi, Osaka Sunstar Giken Co., Ltd. (72) Inventor Masahito Mori 7-1 Akita-cho, Takatsuki-shi, Osaka Sunstar Giken Co., Ltd.

Claims (1)

[Claims] 1. An ABS material having a foamed layer is adhered to an acrylonitrile / butadiene / styrene copolymer (ABS) base material by a vacuum forming method. In a method of applying a two-component aqueous adhesive to either one of the above and drying, then overlaying a heated skin material on an ABS substrate and adhesively molding in a vacuum state, the two-component aqueous adhesive is a) Carbonate diol and formula: A terminal hydroxyl group-containing polyurethane having a carboxyl group obtained by reacting a carboxyl group-containing chain extender (wherein R is hydrogen or a linear or branched alkyl group having 1 to 3 carbon atoms) with a polyisocyanate compound Polycarbonate-urethane emulsion self-emulsifying polymer in water in the presence of tertiary amine, (b) ethylene-vinyl acetate copolymer aqueous emulsion and (c) tackifying resin aqueous emulsion as the main component, and excess fat A method for adhering a skin material having a foam layer to an ABS substrate by a vacuum forming method, which comprises a curing agent composed of a polyurethane prepolymer which is a reaction product of a group-based polyisocyanate and a polyether polyol.