Molded article

A molded article, useful as an interior part of a motor vehicle, is described. The molded article is formed by injecting a synthetic resin material as a base layer into a mold wherein a synthetic resin film has been placed in close contact with a wall of the mold. The base layer is composed of acrylonitrile butadiene-styrene copolymer or denatured acrylonitrile butadiene-styrene copolymer which is obtained by dispersing butadiene rubber particles within a matrix of acrylonitrile-styrene copolymer or denatured acrylonitrile-styrene copolymer. The acrylonitrile-styrene copolymer or denatured acrylonitrile-styrene copolymer matrix has a molecular weight distribution which is greater than 2.18 and less than 3.05.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to a molded article for use as an interior 
part of a motor vehicle, such as a console upper panel, or a cover for a 
radio, for instrument panels or other covered areas. 
2. Description of the Related Art 
A molded article has been used as an interior part of a motor vehicle, such 
as a console upper panel. Generally, the molded article is formed by 
injecting a synthetic resin material into a mold wherein a synthetic resin 
film has been placed, such that the synthetic resin material as a base 
layer is joined to the film and an integrated molded article is formed. 
The film can include a protective layer, a decorative layer formed on the 
surface of the protective layer in a variety of ways including printing, 
painting or vacuum metalizing, and an adhesive layer formed on the surface 
of the decorative layer. The decorative layer can have a wood grain-like 
appearance. The film thus prepared is joined or bonded to a base layer via 
the adhesive layer on the surface of the decorative layer. 
The above-described molded article has the disadvantage that adhesion 
between the film and the base layer is not always sufficient. Because of 
this insufficient adhesion, the molded article can become unattractive 
over time as the film peels away from the base layer. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a molded article having 
improved adhesion between the film and the base layer, and excellent 
resistance to the film peeling from the base layer. This durability 
maintains the appearance of the molded article over a long period of time. 
The molded article of the present invention includes a film comprised of a 
synthetic resin material and a base layer comprised of a synthetic resin 
material formed integrally with the film. The film includes at least a 
protective layer and an adhesive layer. To form the molded article of the 
present invention, the synthetic resin material comprising the base layer 
is pressed into contact with the adhesive layer of the film within a mold 
while melting the contact face of the base layer. In a preferred 
embodiment, the film will have been previously placed within the mold and 
the synthetic resin material, comprising the base layer, is thereafter 
injected into the mold. The base layer is composed of 
acrylonitrile-butadiene-styrene copolymer or denatured 
acrylonitrile-butadiene-styrene copolymer, which is obtained by dispersing 
butadiene rubber particles within a matrix of acrylonitrile-styrene 
copolymer or denatured acrylonitrile-styrene copolymer. The 
acrylonitrile-styrene copolymer or denatured acrylonitrile-styrene 
copolymer, which is adapted to compose the matrix, has a molecular weight 
distribution which is greater than 2.18 and less than 3.05. The preferred 
materials as the matrix include acrylonitrile-styrene copolymer, 
acrylonitrile-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-N-phenylmaleimide copolymer, and a blend of 
acrylonitrile-styrene copolymer and at least one of 
acrylonitrile-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-N-phenylmaleimide copolymer and polycarbonate. 
With the present invention, the adhesion between the base layer and film is 
greatly improved. The reason for this improvement in adhesion has not been 
thoroughly investigated. But upon examining a conventional molded article 
where the film has peeled from a base layer composed of 
acrylonitrile-butadiene-styrene copolymer, it was shown that destruction 
occurred within the base layer. This destruction is believed to be caused 
by the low strength of the acrylonitrile-styrene copolymer matrix. Within 
the weak acrylonitrile-styrene copolymer matrix, butadiene rubber 
particles deform due to the pressure used to inject synthetic resin into 
the mold and orient themselves in a particular direction, which causes 
destruction of the base layer along interfaces between the oriented 
butadiene rubber particles and the matrix. In contrast, with the molded 
article of the present invention, by limiting the molecular weight 
distribution of the matrix to the above-described specific range, the 
matrix is strengthened by preventing the deformation and orientation of 
the butadiene rubber particles, thus achieving excellent adhesion to film. 
A large molecular weight distribution means that the molecular weights of 
the matrix copolymers have a wide scatter, and various molecular weights 
from a low molecular weight to a high molecular weight are included. When 
the number of low molecular weight components is relatively large, the 
fluidity of the matrix of the base layer is enhanced and contact between 
the base layer and the film is facilitated. 
Other objects, features, and characteristics of the present invention will 
become apparent upon consideration of the following description in the 
appended claims with reference to the accompanying drawings, all of which 
form a part of the specification, and wherein like reference numerals 
designate corresponding parts in the various figures.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EXEMPLARY EMBODIMENTS 
Hereinafter, the molded article of the present invention will be explained 
with reference to the accompanying drawings based on the examples wherein 
the present invention is applied to a console upper panel of a motor 
vehicle. 
FIG. 1 is a front view of a console upper panel P and FIG. 2 is an 
enlarged, partial cross-sectional view thereof. As shown, the console 
upper panel P has a base layer 10 which is molded into a predetermined 
configuration and supports a multi-layer synthetic resin film 12 covering 
the entire upper surface of base layer 10. In preparing the multi-layer 
synthetic resin film 12, a decorative layer 14, comprised of polyvinyl 
chloride or a similar material, is formed and is then covered on one side, 
for example, the outer side, by a protective layer 16. The decorative 
layer 14 can be provided with a desired pattern and color, such as, for 
example, a wood grain-like pattern in a variety of shades and/or other 
patterns in various colors. The film thus prepared is bonded or joined to 
the upper surface of the base layer 10 via an adhesive layer 18, comprised 
of vinyl acetate or a similar material, that has been applied to the inner 
side of the decorative layer 14. 
The base layer 10 is composed of acrylonitrile-butadiene-styrene copolymer 
or denatured acrylonitrile-butadiene-styrene copolymer (hereinafter called 
ABS resin). The ABS resin has butadiene rubber particles dispersed within 
a resin matrix. The resins adapted to compose the matrix include 
acrylonitrile-styrene copolymer or denatured acrylonitrile-styrene 
copolymer (hereinafter called AS resin) as a copolymer alone or a blend 
with another monomer or polymer, which enables improvement of the physical 
properties of the matrix. Examples of the above described denatured 
acrylonitrile-styrene copolymer include 
acrylonitrile-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-.alpha.-methyl-styrene copolymer and 
acrylonitrile-styrene-N-phenylmaleimide-copolymer, which enable 
improvement of the heat resistance of the matrix. In addition, a blend of 
acrylonitrile-styrene copolymer and at least one of 
acrylonitrile-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-.alpha.-methyl-styrene copolymer, 
acrylonitrile-styrene-N-phenylmaleimide copolymer and polycarbonate, which 
enables improvement of the heat resistance and fluidity of the matrix is 
also included. 
Alternatively, the matrix may be composed of a derivative of an 
acrylonitrile-styrene copolymer. 
With the present invention, the molecular weight distribution d of the AS 
resin which composes the matrix satisfies the following inequality (1): 
EQU 2.18&lt;d&lt;3.05 (1) 
The molecular weight distribution d is expressed by the following equation 
(2): 
##EQU1## 
A large molecular weight distribution means that the molecular weights of 
the matrix copolymers are widely distributed, namely, components having 
various molecular weights from low molecular weight to high molecular 
weight are included. With the present invention, by limiting the molecular 
weight distribution to the above-described specific range, the adhesion of 
the base layer 10 to the film 12 can be greatly improved. When the 
molecular weight distribution is not greater than 2.18, the content of low 
molecular weight components is low to prevent melting at the interface 
between the base layer 10 and film 12, and adhesion at that interface is 
poor. When the molecular weight distribution is not less than 3.05, the 
strength of the matrix is decreased. 
To produce a console upper panel having the above described arrangement, 
first, a decorative layer 14 having a pattern, such as a grain-like 
pattern, is formed and provided with a protective layer 16 by any of 
several known methods, and the opposite surface of the decorative layer 14 
is coated with an adhesive material 18. After drying the adhesive layer 
18, the resulting multi-layer film 12 is placed within a mold such that 
the adhesive layer 18 faces upwards and the film 12 is heated so that film 
12 can be brought into close contact with a mold wall, for example, by 
evacuation. Next, the ABS resin composing the base layer 10 is melted and 
injected into the mold wherein the film 12 has been placed in close 
contact with the mold wall, thus integrating the base layer 10 with the 
film 12. The preferred temperature of the molten ABS resin is 240.degree. 
C. or more. To prevent orientation of the butadiene rubber particles, it 
is preferred to make the temperature of the molten ABS resin as high as 
possible. 
The molded article thus formed is taken out of the mold, and extraneous 
materials are removed from an outer periphery of the molded article and 
recesses thereof. Thus, a console upper panel as shown in FIG. 1 is 
obtained. 
The molded article of the present invention has been disclosed in Japanese 
Pat. Appl. No. Hei 7-227292, filed on Aug. 10, 1995, the entire contents 
of which are hereby incorporated by reference and relied upon. 
Embodiments 1 to 4 
Console upper panels as shown in FIG. 1 and FIG. 2 were formed by using 
various ABS resins obtained by dispersing butadiene rubber particles into 
various matrices composed of acrylonitrile-.alpha.-methyl-styrene 
copolymer (.alpha.MSt), acrylonitrile-styrene-N-phenylmaleimide copolymer 
(maleimide), and a blend of acrylonitrile-styrene copolymer and 
polycarbonate (PC blend). The composition AN/St, St % and Bd % of each ABS 
resin and the molecular weight distribution d of each AS resin composing 
the matrix are listed in TABLE 1. The molecular weight distribution d of 
each AS resin was measured by a gel permeation chromatography (GPC) device 
(CCPM type, produced by Toso Co., Ltd.) with a Shodex column 
(KF80M.times.2+KF802, produced by Showa Denko, Co., Ltd.) and a photodiode 
array detector (991J type, produced by Waters), and developed with a 
tetrahydrofuran solvent. In TABLE 1, for the case of a blend of 
acrylonitrile-styrene copolymer and polycarbonate (PC blend), the 
molecular weight distribution and the composition of the AS resin or ABS 
resin exclusive of polycarbonate are shown. 
TABLE 1 
______________________________________ 
d AN/St St % Bd % denaturation 
______________________________________ 
Embodiment 1 
2.485 30/70* 59.0 8.0 .alpha. MSt 
Embodiment 2 
2.310 22/78 65.3 16.3 maleimide 
Embodiment 3 
2.530 23/77 71.6 7.0 .alpha. MSt 
Embodiment 4 
2.820 24/76 58.0 24.0 PC blend 
Comparative Ex. 1 
2.033 29/71 58.0 7.0 maleimide 
Comparative Ex. 2 
1.994 30/70 54.0 8.0 " 
Comparative Ex. 3 
1.817 29/71 -- -- " 
Comparative Ex. 4 
2.180 28/72 -- -- " 
Comparative Ex. 5 
3.050 21/79 71.0 11.0 PC blend 
______________________________________ 
*AN/.alpha.MSt 
An acrylic film (110 .mu.m film thickness) was used as the protective layer 
16 of each console upper panel, and a wood grain-like decorative layer 14 
(2 .mu.m film thickness) composed of vinyl chloride was formed on a 
surface of the protective layer 16. A vinyl acetate adhesive was applied 
on an upper surface of the decorative layer 14 and dried to obtain an 
adhesive layer 18. The properties of the acrylic film were as follows: 
______________________________________ 
Pencil hardness 2H 
Transmissivity 92.6% 
Elongation percentage 
500% at 120.degree. C. 
Light resistance fade meter (83.degree. C.) 1000 H 
no abnormality 
______________________________________ 
Then, the film 12 was placed within a mold such that the adhesive layer 18 
faced upwards, heated by a heater for several seconds, and brought into 
close contact with a mold wall by evacuation. Each ABS resin listed in 
TABLE 1 was injected into the mold with the film in close contact with the 
mold wall, thus forming the base layer 10 with the film 12 into a integral 
molded article. The temperature of each ABS resin was adjusted to 
243.degree. C. or 280.degree. C. in Embodiment 1, or 270.degree. C. in 
Embodiments 2-4. The thus prepared molded articles were taken out of the 
mold, and an outer periphery of the molded article and recesses thereof 
was trimmed. 
COMATIVE EXAMPLES 1 to 5 
For comparison, molded articles were prepared using ABS resins having 
various compositions and molecular weight distributions as shown in TABLE 
1, in a process similar to Embodiments 1-4. 
The thus prepared molded articles were subjected to a cross-cut test (ASTM 
D-236), and the adhesion between the base layer 10 and the film 12 was 
examined. The test results are shown in TABLE 2, wherein +++ means that no 
peeling occurred in 100 samples, ++ means that peeling occurred in less 
than 10 out of 100 samples, and + means that peeling occurred in not less 
than 10 out of 100 samples. 
Furthermore, the peeling resistance of film ends and the IZOD impact value 
were examined. The results thereof are also shown in TABLE 2. The peeling 
resistance measured for each sample was evaluated with the following three 
ranks: 
______________________________________ 
+++ no peeling 
++ peeling near film ends 
+ peeling from film ends to about center of film 
______________________________________ 
TABLE 2 
______________________________________ 
Embodi- Embodi- Embodi- Embodi- 
ment 1 ment 2 ment 3 diment 4 
______________________________________ 
Resin set value 
280 243 270 270 270 
tempera- 
measured 288 274 -- -- -- 
ture .degree.C. 
value 
difference 
+8 +29 -- -- -- 
Cross-cut test 
+++ +++ +++ +++ +++ 
(adhesion) 
peeling resistance 
+++ +++ +++ +++ 
Izod impact value J/m 
156.8 147.7 155.5 462.4 
______________________________________ 
Comparative 
Comparative 
Comparative 
Ex. 1 Ex. 2 Ex. 3 
______________________________________ 
Resin set value 
280 243 280 243 280 243 
tempera- 
measured 284 253 273 250 283 260 
ture .degree.C. 
value 
difference 
+4 +10 -5 +7 +3 +17 
Cross-cut test 
+++ ++ ++ + +++ + 
(adhesion) 
peeling resistance 
++ ++ ++ 
Izod impact value J/m 
107.08 108 176.4 
______________________________________ 
Comparative Ex. 4 
Comparative Ex. 5 
______________________________________ 
Resin set value 280 270 
tempera- 
measured 272 -- 
ture .degree.C. 
value 
difference 
-8 -- 
Cross-cut test 
+ +++ 
(adhesion) 
peeling resistance 
+ ++ 
Izod impact value J/m 
117.7 455.9 
______________________________________ 
As is apparent from TABLE 2, in the molded articles of Embodiments 1 
through 4 of the present invention, no peeling occurred after the 
cross-cut test. Particularly, in the molded article of Embodiment 1, no 
peeling occurred even when the difference in the resin temperatures was 
large. In addition, the peeling resistance of film ends and the IZOD 
impact value were both good. These test results show that the molded 
articles of the present invention are excellent in adhesion and impact 
resistance, as compared to the comparative examples. 
FIGS. 3 and 4 show TEM (transmission electron microscope) photographs 
(10,000.times. magnification) of cross sections of molded articles of 
Embodiment 1 and Comparative Example 1. As shown, the protective layer 16, 
the decorative layer 14, the adhesive layer 18 and the base layer 10 are 
arranged in descending order. In the lowermost base layer 10, butadiene 
rubber particles are dispersed within the matrix of AS resin. As is 
apparent from these photographs, in the molded article of Embodiment 1 
(FIG. 3), the butadiene rubber particles dispersed within the matrix of AS 
resin are spherical while in the molded article of Comparative Example 1 
(FIG. 4), the butadiene rubber particles deform into ellipsoids and are 
oriented horizontally due to the injection pressure. 
FIGS. 5 and 6 show TEM photographs (10,000.times. magnification) of joined 
parts of molded articles of Embodiment 1 and Comparative Example 1, 
respectively, after the cross-cut test. As is apparent from these 
photographs, in the molded article of Embodiment 1 (FIG. 5), no peeling 
occurred while in the molded article of Comparative Example 1 (FIG. 6), 
destruction occurred within the lowermost base layer 10. This is believed 
to be caused by the butadiene rubber particles within the matrix of 
Comparative Example 1 being oriented horizontally, as shown in FIG. 3. 
This allows destruction of the base layer along interfaces between the 
butadiene rubber particles and the matrix, thus generating peeling. 
As described above, the molded article of the present invention has 
excellent adhesion between the film and the base layer, and no peeling of 
the film would occur even after long use of the molded article of the 
present invention. Therefore, the molded article of the present invention 
is preferably used as an interior part of a motor vehicle, such as, for 
example, a console upper panel, and is capable of maintaining good 
durability and an attractive appearance over a long period of time. 
While the invention has been described in connection with what are 
considered presently to be the most practical and preferred embodiments, 
it is to be understood that the invention is not limited to the disclosed 
embodiments, but, on the contrary, is intended to cover various 
modifications and equivalent arrangements included within the spirit and 
scope of the appended claims.