Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Composite having voids in a component
Reexamination Certificate
2002-11-26
2004-08-03
Lipman, Bernard (Department: 1713)
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Composite having voids in a component
C428S317300, C428S317700
Reexamination Certificate
active
06770357
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a precoated skin material for an automobile interior part. In particular, the present invention relates to a precoated skin material for an automobile interior part comprising a skin material and a one-pack type thermally crosslinkable polymer composition comprising a specific thermoplastic polymer, a polyamine compound as a latent curing agent and a solvent.
2. Prior Art
As interior parts of automobiles, laminates comprising substrate layers and skin materials laminated on the substrate layers have been used to improve quality. Such a laminate is produced by a vacuum molding or press molding method in which an adhesive is applied to either one or both of the substrate layer and the skin material, and the molding and adhering are performed at the same time.
In such a molding method to adhere the skin material to the surface of the substrate layer by vacuum molding or press molding, a solvent-base adhesive is generally used, which comprises a polyesterpolyurethane containing a polyester as a polyol component dissolved in a solvent. However, this type of an adhesive has insufficient heat resistance required for the use in automobile interior applications, and a two-pack type adhesive containing a polyisocyanate as a curing agent is practically used. Such a two-pack type adhesive has some drawbacks such that it causes the environmental pollution since the adhesive is spray coated in a parts-molding line, and that the working time for mixing, coating and molding/adhering is restricted since two liquid components are reacted on mixing and cured.
SUMMARY OF THE INVENTION
One object of the present invention is to provide a one-pack type thermally crosslinkable polymer composition which can solve the above drawbacks of the conventional adhesives, and which is useful, for example, as an adhesive that is beforehand coated on a back surface of a skin material to provide a precoated skin material in the production of an interior part of an automobile.
Another object of the present invention is to provide a precoated skin material for an automobile interior part, which provides an automobile interior part comprising a substrate layer and a skin material adhered to the surface of the substrate layer, and which has initial heat resistant adhesion properties.
Accordingly, the present invention provides a precoated skin material for an automobile interior part comprising (a) a skin material for an automobile interior part and (b) a one-pack type thermally crosslinkable polymer composition comprising (i) a thermoplastic olefinic polymer having a carboxylic acid group or an acid anhydride group, (ii) a latent curing agent, (iii) a carbonyl compound as a solvent and (iv) a tackifier, which composition is coated on the back surface of said skin material, wherein said latent curing agent is at least one compound selected from the group consisting of solid polyamines having a melting point of 80 to 200° C. which form hydrolyzable reaction products by a condensation reaction with said carbonyl compound used as the solvent, and hydrolyzable reaction products of diamines with carbonyl compounds.
The one-pack type adhesive used in the present invention can be stored at room temperature without the occurrence of a reaction, and crosslinked at a temperature of 60° C. or higher to exert good adhesion strength with good heat resistance.
DETAILED DESCRIPTION OF THE INVENTION
The thermoplastic polymers having a carboxylic acid group or an acid anhydride group may be olefinic polymers, butadiene polymers, ester polymers, carbonate polymers, urethane polymers, amide polymers, etc., all of which have a carboxylic acid group or an acid anhydride group. In particular, olefinic polymers having a carboxylic acid group or an acid anhydride group is preferable from the viewpoint of adhesion properties to polyolefins.
Typical examples of such thermoplastic polymers include polypropylene (PP), styrene-ethylene/butene-styrene copolymers (SEBS), ethylene-vinyl acetate copolymers (EVA), ethylene-acrylate copolymers (EEA), and the like, each of which is modified by the introduction of a dibasic unsaturated acid (e.g. maleic acid, fumaric acid, citraconic acid, mesaconic acid, etc.) or its anhydride. Such modified polymers are known and commercially available.
Hereinafter, thermoplastic polymers having a carboxylic acid group or an acid anhydride group will be referred to as “COOH-modified polymers”.
Polyamine compounds used as latent curing agents are divided into the following two classes (I) and (II):
(I) Solid polyamine compounds having a melting point of 60° C. or higher, preferably 80 to 200° C., for example, aromatic polyamines such as 4,4′-diaminodiphenylmethane, 2,4′-diaminodiphenylmethane, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 2,2′-diaminobiphenyl, 2,4′-diaminobiphenyl, 3,3′-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o-phenylenediamine, m-phenylenediamine, 2,3-tolylenediamine, 2,4-tolylenediamine, 2,5-tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine, etc.; aliphatic polyamines such as 1,12-dodecanediamine, 1,10-decanediamine, 1,8-octanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, etc.; hydrazide base polyamine such as 1,3-bis(hydrazinocarboethyl)-5-isopropylhydantoin of the formula:
(melting point: 121-123° C.), the compound of the formula: NH
2
NHCO—(CH
2
)
18
—CONHNH
2
(melting point: 174-181° C.), the compound of the formula: NH
2
NHCO—(CH
2
)
6
—CH═CH—(CH
2
)
2
—CH═CH—(CH
2
)
6
—CONHNH
2
(melting point: 147-155° C.), the compound of the formula: NH
2
NHCO—(CH
2
)
4
—CONHNH
2
(melting point: 177-183° C.), the compound of the formula: NH
2
NHCO—(CH
2
)
8
—CONHNH
2
(melting point: 186-188° C.), the compound of the formula: NH
2
NHCO—(CH
2
)
10
—CONHNH
2
(melting point: 189-191° C.), isophthalic dihydrazide (melting point: 215-225° C.); and the like. These polyamines may be used singly or in admixture of two or more.
An amount of the polyamine compound to be used is at least an equivalent amount to the carboxyl groups of the COOH-modified polymer. When the amount of the polyamine compound is less than the equivalent amount, the crosslinking of the polymer is insufficient, and the heat resistance of the cured material deteriorates. When the amount of the polyamine compound is too large, the curing agent is liberated, so that adherents may be insufficiently adhered. Accordingly, a preferred amount of the polyamine compound to be used is one to 10 times the equivalent amount.
(II) Hydrolyzable reaction products obtained by the reaction of diamines having two amino or imino groups in a molecule, and carbonyl compounds (aldehydes or ketones)
Examples of such diamines include aliphatic diamines (e.g. dimethylaminopropylamine, diethylaminopropylamine, monomethylaminopropylamine, methyliminobispropylamine, hexamethylenediamine, 1,10-diaminododecane, ethylenediamine, propylenediamine, butylenediamine, diethylenetriamine, di-&bgr;-aminoethylsulfide, di-&bgr;-aminoethyldisulfide, di-&bgr;-aminoethylether, di-&ggr;-amino-n-propylether, triglycoldiamine, N,N-dibutyltrimethylhexamethylenediamine, etc.); alicyclic diamines (e.g. 1,8-p-menhanediamine, isophoronediamine, diaminocyclohexane, 4,4′-methylenebis(cyclohexylamine), 1,3-bisaminomethylcyclohexane, 3-aminomethyl-3,3,5-trimethylcyclohexylamine, N,N′-butylisophoronediamine, N-aminoethylpiperazine, 3-(3-aminopropyl)-3,2-dimethylpiperazine, etc.); aromatic or aromatic aliphatic diamines (e.g. xylylenediamine, diaminodiphenylether, phenylenediamine, triamionxylene, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenylether, etc.); and the like. In particular, aliphatic diamines having 8 or more carbon atoms are preferred.
Furthermore, hydrolyzable reaction products can be prepared by reacting the solid polyamines (I) described above with carbonyl compounds.
The above carbonyl compound is generally represented by the formula:
R
1
Mori Masahito
Okamoto Hirokazu
Jacobson & Holman PLLC
Lipman Bernard
Sunstar Giken Kabushiki Kaisha
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