JP2003268339A - Adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for an automotive interior which is used when bonding a plastic sheet of PVC containing a large amount of a plasticizer to a glass fiber reinforced plastic (hereafter referred to as FRP). <P>SOLUTION: The adhesive composition comprises per 100 pts.wt. of a polyurethane resin, 100-250 pts.wt. of a rosin glycerin ester, 0.5-10 pts.wt. of an epoxy silane, and 10-100 pts.wt. of a polyisocyanate, the polyisocyanate being a derivative of its buret compound or its trimethylolpropane compound. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive composition for automobile interiors, which is used when a plastic sheet containing a large amount of a plasticizer such as PVC and a glass fiber reinforced plastic (FRP) are bonded.

[0002]

2. Description of the Related Art Interior parts of automobiles, particularly floor materials and luggage floors, are generally composed of a skin material and a molded product. In particular, when the FRP molded product and the PVC skin material are bonded to each other, it is often the case that a nitrile rubber-based adhesive that causes less plasticizer migration due to PVC is used and bonded by press bonding.

[0003]

However, the heat-resistant temperature of the portion exposed to direct sunlight in the interior of the automobile is 10
It is necessary to use 0 ° C. or higher, but the nitrile rubber adhesive cannot be used because it has low heat resistance and causes floating and peeling in the shape part. Further, as an adhesive having less plasticizer migration by PVC, a urethane resin adhesive may be mentioned. However, since the urethane resin adhesive has low adhesiveness to FRP, the adhesive is required to secure a desired adhesive strength. It is necessary to apply a primer to the FRP before applying. In that case, problems such as an increase in the number of steps occur.

[0004]

As a result of earnest research, the present inventors have found that polyurethane resin, rosin glycerin ester,
It has been found that by blending an epoxysilane and a polyisocyanate, it has heat resistance of 100 ° C., less plasticizer migration by PVC, and improved adhesion to FRP.

That is, the present invention provides an adhesive characterized by containing a polyurethane resin, rosin glycerin ester, epoxysilane and polyisocyanate,
100 parts by weight of polyurethane resin, 100 to 250 parts by weight of rosin glycerin, 0.5 to 10 parts by weight of epoxysilane, and 10 to 1 parts of polyisocyanate.
And 100 parts of the polyisocyanate is hexamethylene diisocyanate or a derivative thereof such as a buret body or a trimethylolpropane body, and relates to an adhesive composition for automobile interiors.

The polyurethane resin of the present invention is an elastomer having a urethane bond in the molecular chain and is usually a dihydric alcohol (1,4-butanediol, 1,6-hexanediol, diethylene glycol, ethylene glycol, propylene glycol, etc.). ) And a polybasic acid (adipic acid, terephthalic acid, isophthalic acid, phthalic acid, succinic acid, sebacic acid, etc.) are subjected to a condensation reaction to obtain a saturated polyester resin having a terminal hydroxyl group, and its active hydrogen group and diisocyanate are obtained. It is a polymer obtained by reacting a compound (diphenylmethane diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, etc.) with an isocyanate group in an approximately equivalent amount.

The rosin glycerin ester of the present invention is
It is an ester compound of glycerin and an ester compound of a derivative such as rosin or a polymer thereof (rosin, polymerized rosin, hydrogenated rosin and disproportionated rosin).

The epoxysilane of the present invention means γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, 3,4-epoxycyclohexylethyltrimethoxysilane and 3,4-epoxycyclohexylethylmethyl. Dimethoxysilane and the like can be mentioned, and at least one selected from these groups can be used.

The polyisocyanate of the present invention is hexamethylene diisocyanate or its derivative such as buret or trimethylolpropane. If necessary, diphenylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, etc.,
One or more other isocyanates may be included.

The mixing ratio of the urethane resin and the rosin glycerin ester is preferably such that the weight ratio of the urethane resin / rosin glycerin ester is 100/100 to 100/250. When the rosin glycerin ester is less than 100, the adhesiveness to FRP is low. When the value exceeds 250, the stress relaxation property of the adhesive is deteriorated, so that the adhesiveness is deteriorated particularly at low temperature.

The mixing ratio of urethane resin and epoxysilane is such that the weight ratio of urethane resin / epoxysilane is 100 /
It is preferably from 0.5 to 100/10. When the epoxysilane is less than 0.5, heat resistance and adhesion to FRP are deteriorated, and when it exceeds 10, storage stability of the adhesive is deteriorated. .

The blending ratio of the urethane resin and the polyisocyanate is preferably such that the weight ratio of the urethane resin / polyisocyanate is from 100/10 to 100/100, and when the polyisocyanate is less than 10, the crosslink density is lowered, resulting in heat resistance. When the properties deteriorate and exceed 100, the proportion of polyisocyanate, which is a low molecular weight component, increases as compared with other materials, and the cohesive force immediately after adhesion decreases, so molding with a particularly high expansion rate of PVC. In the adhesion of objects, floating occurs due to residual stress of PVC.

The present adhesive can be used after it is usually dissolved with an organic solvent. Examples of the organic solvent used for the adhesive include ester type (ethyl acetate, butyl acetate, etc.), ketone type (acetone, methyl ethyl ketone, etc.), aromatic type (toluene, xylene, etc.). In addition to these, it is possible to add a catalyst for accelerating the reaction, a stabilizer such as an anti-aging agent, a coloring agent, a filler and the like, if necessary.

The present invention can be used as a one-part or two-part adhesive. When used as one liquid, the isocyanate group (NCO) of the polyisocyanate compound is in excess of the hydroxyl group (OH) of the polyester polyol and rosin glycerin ester, preferably OH /
It is obtained by compounding so that NCO = 1 / 1.2 to 3 and terminally isocyanated. The reaction may be performed in a suitable organic solvent (toluene, methyl ethyl ketone, ethyl acetate, n-hexane, etc.) at room temperature to 80 ° C. for 2 to 50 hours, and the prepolymer obtained has an active isocyanate content of 0.5 to 20% (% by weight, the same applies below),
It is preferably adjusted to 1.0 to 5%. A catalyst such as dibutyltin dilaurylate may be used in the reaction. When used as a two-component adhesive, the main component (polyurethane resin, rosin glycerin ester,
It can be used by mixing a solution of epoxysilane or the like dissolved in a solvent) with a crosslinking agent component (polyisocyanate) before use.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present adhesive composition thus obtained is used for molding and bonding automobile interior materials, and PVC skin materials (sheets, films, foams, etc.) containing a large amount of plasticizer.
It is especially suitable for molding and bonding of FRP molded products. In addition to this, the present adhesive can be used for bonding wood and metal materials in addition to FRP molded products.

[0016]

EXAMPLES Next, the present invention will be described in more detail by way of examples and comparative examples, and the results of these specific examples are shown in Table 1, but the present invention is not limited to these examples. In the text, all parts are parts by weight.

(Example) Urethane resin (Pandex T
-5205; manufactured by Dainippon Ink and Chemicals, Inc.) 100 parts, rosin glycerin ester (vinzole ester gum; manufactured by Hercules Co., Ltd.) 200 parts, γ-glycidoxypropyltrimethoxysilane (A-187; manufactured by Nippon Unicar Co., Ltd.) 2
After heating and stirring at 60 ± 2 ° C. in a flask in which 500 parts of methyl ethyl ketone was replaced with nitrogen, polyisocyanate (Coronate HL; manufactured by Nippon Polyurethane Co.)
Was added to carry out a graft reaction. While maintaining the inside of the flask at 60 ± 2 ° C., the mixture was heated and stirred for 2 hours, then cooled to room temperature to stop the reaction, and thus an adhesive (I) was obtained.

[0018]

Comparative Example 1 Comparative Example 1 The adhesive obtained in Example 1 was replaced with 20 parts of rosin glycerin ester (vinsol ester gum) to obtain an adhesive (II).

(Comparative Example 2) The rosin glycerin ester (binzole ester gum) of the adhesive obtained in Example 1
The adhesive (III) was obtained by substituting 300 parts for the addition amount of.

Comparative Example 3 γ-glycidoxypropyltrimethoxysilane (A-1) of the adhesive obtained in Example 1
The adhesive (IV) was obtained by replacing the addition number of 87) with 0 part.

(Comparative Example 4) γ-glycidoxypropyltrimethoxysilane (A-1) of the adhesive obtained in Example 1
87) was replaced with 20 parts, and the adhesive (IV)
Got

(Comparative Example 5) The number of parts to be added of polyisocyanate (Coronate HL) in the adhesive obtained in Example 1 was 5
Parts to obtain an adhesive (V).

Comparative Example 6 The polyisocyanate (Coronate HL) added to the adhesive obtained in Example 1 was added to 1 part.
Substituting for 50 parts to obtain an adhesive (VI).

(Adhesion test) The obtained adhesive was applied on both sides of a FRP molded product and a PVC sheet by using a spray gun (application amount per one side; 150 g / m ² -wet).
Then, it was dried in a drying oven set at 80 ° C. for 2 minutes. Two
The FRP molded product and PVC left for 1 minute in 0 ° C atmosphere
Pressure of 49kP by press bonding with sheet (1mm thickness)
It was clamped at a for 30 seconds. Adhesives at 20 ℃ ・ 65% RH
After curing for 10 minutes or 24 hours in an atmosphere, 180 ° peeling adhesive strength was measured by a tensile tester in an atmosphere of 20 ° C. Also, the bonded product is aged in an atmosphere of 20 ° C. and 65% RH for 24 hours, and a 100 g / 25 mm load is applied vertically to one end of the skin material in an atmosphere of 100 ° C. for a 24-hour creep test to determine the peeling length. taking measurement. The test results are shown in Table 1.

[0025]

[Table 1]

[0026]

As described above, the present invention is an adhesive composition for automobile interiors, which is used for adhering FRP to a plastic sheet containing a large amount of plasticizer such as PVC.
It has almost the same peel adhesion strength as the nitrile rubber adhesives that are mainly used at present, and has high heat resistance. Further, according to the present invention, as compared with a urethane resin-based adhesive that requires FRP to be coated with a primer in advance, it is possible to obtain a desired adhesive strength in a small number of steps because the primer coating is unnecessary.

Claims (2)

[Claims] 1. To 100 parts by weight of a polyurethane resin,
An adhesive composition comprising 100 to 250 parts by weight of rosin glycerin ester, 0.5 to 10 parts by weight of epoxysilane, and 10 to 100 parts by weight of polyisocyanate. 2. The adhesive composition according to claim 1, wherein the polyisocyanate is hexamethylene diisocyanate or a derivative thereof such as a buret body or a trimethylolpropane body.