U.S. patent application number 10/508876 was filed with the patent office on 2005-07-28 for polybutylene terephthalate resin composition for fusion bonding with laser and molded article.
Invention is credited to Matsushima, Mitsunori, Sakata, Kouichi, Takayama, Katsunori.
Application Number | 20050165176 10/508876 |
Document ID | / |
Family ID | 28786392 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050165176 |
Kind Code |
A1 |
Matsushima, Mitsunori ; et
al. |
July 28, 2005 |
Polybutylene terephthalate resin composition for fusion bonding
with laser and molded article
Abstract
A laser weldable PBT-series resin composition comprises a
polybutylene terephthalate (PBT)-series resin (A), and at least one
resin (B) selected from the group consisting of a
polycarbonate-series resin (b1), a styrenic resin (b2), a
polyethylene terephthalate-series resin (b3) and an acrylic resin
(b4). The PBT-series resin (A) may be a PBT homopolyester, or a
PBT-series copolymer modified with not more than 30 mol % of a
copolymerizable monomer (e.g., a bisphenol compound or an adduct
thereof with an alkylene oxide, and an asymmetrical aromatic
dicarboxylic acid). The ratio (weight ratio) of the resin (B)
relative to the PBT-series resin (A) [the former/the latter] is
about 0.1/1 to 1.5/1. The resin composition may comprise a glass
fiber. The resin composition is excellent in laser weldability, and
can improve in welding strength of a shaped article formed from the
resin composition.
Inventors: |
Matsushima, Mitsunori;
(Fuji-shi, JP) ; Sakata, Kouichi; (Fuji-shi,
JP) ; Takayama, Katsunori; (Fuji-shi, JP) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Family ID: |
28786392 |
Appl. No.: |
10/508876 |
Filed: |
September 23, 2004 |
PCT Filed: |
April 8, 2003 |
PCT NO: |
PCT/JP03/04455 |
Current U.S.
Class: |
525/437 |
Current CPC
Class: |
B29C 66/72143 20130101;
B29C 66/7212 20130101; B29C 66/43 20130101; C08L 69/00 20130101;
B29C 66/81267 20130101; B29K 2995/0027 20130101; B29C 65/8215
20130101; B29C 65/1606 20130101; B29C 66/73941 20130101; C08L
2205/02 20130101; B29C 65/1638 20130101; B29C 65/1677 20130101;
B29C 65/1654 20130101; B29C 66/73921 20130101; C08L 25/04 20130101;
C08L 67/02 20130101; B29C 66/8122 20130101; B29C 65/1635 20130101;
B29C 66/71 20130101; C08L 25/12 20130101; B29C 65/1616 20130101;
B29C 66/1122 20130101; C08L 67/02 20130101; C08L 2666/04 20130101;
C08L 67/02 20130101; C08L 2666/02 20130101; C08L 67/02 20130101;
C08L 2666/18 20130101; C08L 67/02 20130101; C08L 2666/06 20130101;
C08L 69/00 20130101; C08L 2666/18 20130101; B29C 66/71 20130101;
B29C 65/00 20130101; B29C 66/71 20130101; B29K 2067/006 20130101;
B29C 66/7212 20130101; B29K 2309/08 20130101; B29C 66/71 20130101;
B29K 2069/00 20130101; B29C 66/71 20130101; B29K 2067/003 20130101;
B29C 66/71 20130101; B29K 2025/08 20130101; B29C 66/71 20130101;
B29K 2025/04 20130101; B29C 66/8122 20130101; B29K 2833/12
20130101; B29C 66/8122 20130101; B29K 2909/14 20130101 |
Class at
Publication: |
525/437 |
International
Class: |
C08L 067/02 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 8, 2002 |
JP |
2002-105649 |
Claims
1. A laser weldable polybutylene terephthalate-series resin
composition which comprises a polybutylene terephthalate-series
resin (A) and at least one resin (B) selected from the group
consisting of a polycarbonate-series resin (b1), a styrenic resin
(b2), a polyethylene terephthalate-series resin (b3) and an acrylic
resin (b4).
2. A resin composition according to claim 1, wherein the
polybutylene terephthalate-series resin (A) comprises a
polybutylene terephthalate or a polybutylene terephthalate-series
copolymer modified with a copolymerizable monomer.
3. A resin composition according to claim 2, wherein the
copolymerizable monomer comprises at least one member selected from
the group consisting of a bisphenol compound or an adduct thereof
with an alkylene oxide, and an asymmetrical aromatic dicarboxylic
acid or a derivative thereof capable of forming an ester.
4. A resin composition according to claim 2, wherein the
copolymerizable monomer comprises at least one member selected from
the group constituting of phthalic acid, isophthalic acid, and an
adduct of bisphenol A with an alkylene oxide, and a reactive
derivative thereof.
5. A resin composition according to claim 1, wherein the ratio of
the resin (B) relative to the polybutylene terephthalate-series
resin (A) [the former (B)/the latter (A)] is 0.1/1 to 1.5/1 (weight
ratio).
6. A resin composition according to claim 1, which has a light
transmittance of not less than 15% for a wavelength of 800 to 1100
nm at a thickness of 3 mm in a shaped article formed from the resin
composition by an injection molding.
7. A resin composition according to claim 1, which further
comprises a reinforcer capable of transmitting a laser beam.
8. A resin composition according to claim 1, which further
comprises a glass fiber.
9. A laser weldable polybutylene terephthalate-series resin
composition which comprises at least one polybutylene
terephthalate-series resin (A) selected from the group consisting
of a polybutylene terephthalate and a polybutylene
terephthalate-series copolymer modified with 0.01 to 30 mol % of a
copolymerizable monomer, and at least one resin (B) selected from
the group consisting of a polycarbonate-series resin (b1), a
styrenic resin (b2), a polyethylene terephthalate-series resin (b3)
and an acrylic resin (b4), wherein the ratio of the resin (B)
relative to the polybutylene terephthalate-series resin (A) [the
former (B)/the latter (A)] is 0.1/1 to 1.5/1 (weight ratio), and
the copolymerizable monomer comprises at least one member selected
from the group consisting of phthalic acid, isophthalic acid, an
adduct of bisphenol A with an alkylene oxide, and a reactive
derivative thereof.
10. A shaped article formed from a resin composition recited in
claim 1.
11. A shaped composite article comprising a shaped article formed
from a resin composition recited in claim 1, and a counterpart
shaped article formed from a resin, wherein the shaped article is
bonded to the counterpart shaped article through a welding by a
laser.
Description
TECHNICAL FIELD
[0001] The present invention relates to a polybutylene
terephthalate-series resin composition having a high laser
weldability and being excellent in shaping processability (or
moldability), and a shaped article using the same.
BACKGROUND ART
[0002] A polybutylene terephthalate (PBT)-series resin is excellent
in various properties such as heat resistance, chemical resistance,
electric properties, mechanical properties and shaping
processability (or moldability), and is used for a number of
applications. Specific examples of the applications include a
variety of automotive electrical components or parts (e.g., various
control units, various sensors, and ignition coils), connectors,
switch parts, relay parts, and coil parts. For producing these
components, a plurality of shaped components or parts are bonded
(or joined) to each other with the use of a bonding (or joining)
means such as an adhesive, a screw cramp, a snap fit, a hot plate
welding, and an ultrasonic welding. Regarding these bonding means,
however, some problems have been pointed out. For example, in the
case of using an adhesive, the waste of time up to curing of the
adhesive, or the burden on the environment becomes an issue.
Moreover, in a means using a screw cramp, the labor or the cost
required for fastening increases, and in a hot plate welding or an
ultrasonic welding, there is fear that a product receives a damage
due to heat, vibration, and others.
[0003] On the other hand, a bonding (or joining) method by a laser
welding has no damage of a product due to heat or vibration
involved in the welding, and the welding process is also very
simple. Thus, recently the laser welding method has been widely
utilized, and has come to attract attention as a welding manner for
various resin components or parts.
[0004] However, it is pointed out that, in the case of bonding a
PBT-series resin with a laser welding, the resin cannot be
substantially welded because of carbonization or others due to a
low transmittance of a laser beam. Japanese Patent Application
Laid-Open No. 26656/2001 (JP-2001-26656A) discloses that a shaped
article formed from a polyester-series copolymer having a melting
point within a specific range is bonded to other shaped article by
welding processing to form a united shaped article. This document
describes that a homopolyalkylene arylate resin (a polybutylene
terephthalate, a polyethylene terephthalate, and a polyethylene
naphthalate) has a low laser welding strength.
[0005] Japanese Patent Application Laid-Open No. 245481/1998
(JP-10-245481A) discloses a thermoplastic resin composition which
comprises a composition composed of a thermoplastic polycarbonate
resin and a thermoplastic polyester resin (such as a polyethylene
terephthalate) and a methacrylic ester-series resin (graft resin)
blended therewith in a proportion of 1 to 10% by weight, in which
the methacrylic ester-series resin is obtained by
graft-polymerizing a monomer containing a methacrylic ester as a
main component in the presence of a crosslinked acrylic
ester-series elastic body. This document mentions an embodiment in
which a bisphenol A-based polycarbonate resin and a polyethylene
terephthalate resin are used in a proportion of 1.5/1 to 4/1
(weight ratio) in the resin composition. Further, as a heat-welding
method of the resin composition, a hot plate welding, a vibration
welding or an ultrasonic welding is also described. In this
composition, however, it is necessary to use the graft resin in
order to improve welding strength of the composition, and the use
of the graft resin tends to deteriorate mechanical strength, heat
resistance or others of the composition.
[0006] It is therefore an object of the present invention to
provide a laser weldable PBT-series resin composition having an
excellent laser weldability and a high welding strength even in the
case of using a PBT-series resin as a base, and a shaped article
formed from the same.
[0007] It is another object of the present invention to provide a
shaped article of a PBT-series resin, which is high in light
transmittance and welding strength.
DISCLOSURE OF THE INVENTION
[0008] The inventors of the present invention made intensive
studies to achieve the above objects and finally found that a
combination use of a PBT-series resin and a specific resin
dramatically improves laser weldability of a PBT-series resin
composition and realizes to maintain a high weld strength. The
present invention was accomplished based on the above finding.
[0009] That is, the laser weldable polybutylene
terephthalate-series resin composition of the present invention
comprises a polybutylene terephthalate-series resin (A) and at
least one resin (B) selected from the group consisting of a
polycarbonate-series resin (b1), a styrenic resin (b2), a
polyethylene terephthalate-series resin (b3) and an acrylic resin
(b4). The polybutylene terephthalate-series resin (A) may be a
polybutylene terephthalate or a polybutylene terephthalate-series
copolymer modified with a copolymerizable monomer (e.g., a monomer
of 0.01 to 30 mol %). The melting point of the polybutylene
terephthalate-series resin (A) may for example be not lower than
190.degree. C. The copolymerizable monomer may be at least one
member selected from the group consisting of a bisphenol compound
or an adduct thereof with an alkylene oxide, and an asymmetrical
aromatic dicarboxylic acid or a derivative thereof capable of
forming an ester (for example, phthalic acid, isophthalic acid, an
adduct of bisphenol A with an alkylene oxide, and a reactive
derivative thereof). The ratio of the resin (B) relative to the
polybutylene terephthalate-series resin (A) [the former (B)/the
latter (A)] may be about 0.10/1 to 1.5/1 (weight ratio). The resin
composition may further comprise a reinforcer capable of
transmitting a laser beam (for example, a glass fiber). The resin
composition may have a light transmittance of not less than 15% for
a wavelength of 800 to 1100 nm at a thickness of 3 mm in a shaped
article formed from the resin composition by an injection
molding.
[0010] The laser weldable polybutylene terephthalate-series resin
composition of the present invention comprises at least one
polybutylene terephthalate-series resin (A) selected from the group
consisting of a polybutylene terephthalate and a polybutylene
terephthalate-series copolymer modified with 0.01 to 30 mol %
(e.g., 1 to 20 mol %) of a copolymerizable monomer, and at least
one resin (B) selected from the group consisting of a
polycarbonate-series resin (b1), a styrenic resin (b2), a
polyethylene terephthalate-series resin (b3) and an acrylic resin
(b4); wherein the ratio of the resin (B) relative to the
polybutylene terephthalate-series resin (A) [the former (B)/the
latter (A)] is 0.10/1 to 1.5/1, and the copolymerizable monomer
comprises at least one member selected from the group consisting of
phthalic acid, isophthalic acid, an adduct of bisphenol A with an
alkylene oxide, and a reactive derivative thereof.
[0011] The present invention includes a shaped article formed from
the resin composition, and also includes a shaped composite article
comprising the shaped article and a counterpart shaped article
formed from a resin, wherein the shaped article is bonded to the
counterpart shaped article through a welding by a laser.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 shows a schematic side elevational view for
illustrating a laser welding in Examples.
[0013] FIG. 2 shows a plan view for illustrating a laser welding in
Examples.
DETAILED DESCRIPTION OF THE INVENTION
[0014] [Polybutylene Terephthalate-Series Resin Composition]
[0015] (A) Polybutylene Terephthalate-Series Resin
[0016] The polybutylene terephthalate (PBT)-series resin as a base
resin includes a homopolyester or copolyester (a polybutylene
terephthalate, a polybutylene terephthalate copolyester) containing
a butylene terephthalate as a main component (e.g., about 50 to
100% by weight, preferably about 60 to 100% by weight, and more
preferably about 75 to 100% by weight). In particular, a
copolyester is preferred.
[0017] As the copolymerizable monomer (or comonomer) in the
copolyester (a butylene terephthalate-series copolymer or a
modified PBT resin) (hereinafter, sometimes simply refers to a
copolymerizable monomer), there may be mentioned a dicarboxylic
acid other than terephthalic acid, a diol other than
1,4-butanediol, a hydroxycarboxylic acid, a lactone, and others.
The copolymerizable monomer may be used singly or in
combination.
[0018] The dicarboxylic acid component includes, for example, an
aliphatic dicarboxylic acid (e.g., a dicarboxylic acid having about
4 to 40 carbon atoms such as succinic acid, glutaric acid, adipic
acid, pimelic acid, suberic acid, azelaic acid, sebacic acid,
undecanedicarboxylic acid, dodecanedicarboxylic acid,
hexadecanedicarboxylic acid and dimeric acid, preferably a
dicarboxylic acid having about 4 to 14 carbon atoms), an alicyclic
dicarboxylic acid (e.g., a dicarboxylic acid having about 8 to 12
carbon atoms such as hexahydrophthalic acid, hexahydroisophthalic
acid, hexahydroterephthalic acid, and himic acid), an aromatic
dicarboxylic acid other than terephthalic acid [e.g., a
dicarboxylic acid having about 8 to 16 carbon atoms such as
phthalic acid, isophthalic acid; a naphthalenedicarboxylic acid
(such as 2,6-naphthalenedicarboxylic acid);
4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic
acid, 4,4'-diphenylmethanedicarboxylic acid, and
4.4'-diphenylketonedicar- boxylic acid], or a reactive derivative
thereof [e.g., a derivative, capable of forming an ester, such as a
lower alkyl ester (e.g., a C.sub.1-4alkyl ester of phthalic acid or
isophthalic acid, such as dimethyl phthalate and dimethyl
isophthalate (DMI)), an acid chloride, and an acid anhydride].
Further, if necessary, the dicarboxylic acid component may be used
in combination with a polyfunctional carboxylic acid such as
trimellitic acid and pyromellitic acid.
[0019] As the diol, for example, there are mentioned an aliphatic
alkylene glycol other than 1,4-butanediol (e.g., an aliphatic
glycol having about 2 to 12 carbon atoms such as ethylene glycol,
trimethylene glycol, propylene glycol, neopentyl glycol,
hexanediol, octanediol and decanediol, preferably an aliphatic
glycol having about 2 to 10 carbon atoms), a polyoxyalkylene glycol
[e.g., a glycol having a plurality of oxyalkylene units of which
the alkylene group has about 2 to 4 carbon atoms, for example,
diethylene glycol, dipropylene glycol, ditetramethylene glycol,
triethylene glycol, tripropylene glycol, a polytetramethylene
glycol], an alicyclic diol (e.g., 1,4-cyclohexanediol,
1,4-cyclohexanedimethanol, hydrogenated bisphenol A), an aromatic
diol [e.g., a C.sub.6-14 aromatic diol such as hydroquinone,
resorcinol and naphthalenediol; biphenol; a bisphenol compound; and
xylylene glycol], and others. Further, if necessary, the diol may
be used in combination with a polyol such as glycerin,
trimethylolpropane, trimethylolethane and pentaerythritol.
[0020] The bisphenol compound includes a
bis(hydroxyaryl)C.sub.1-6alkane such as bis(4-hydroxyphenyl)methane
(bisphenol F), 1,1-bis(4-hydroxyphenyl)ethane (bisphenol AD),
1,1-bis(4-hydroxyphenyl)pr- opane, 2,2-bis(4-hydroxyphenyl)propane
(bisphenolA), 2,2-bis(4-hydroxy-3-methylphenyl)propane,
2,2-bis(4-hydroxyphenyl)butane,
2,2-bis(4-hydroxyphenyl)-3-methylbutane,
2,2-bis(4-hydroxyphenyl)hexane, and
2,2-bis(4-hydroxyphenyl)-4-methylpentane; a
bis(hydroxyaryl)C.sub.4-1- 0cycloalkane such as
1,1-bis(4-hydroxyphenyl)cyclopentane and
1,1-bis(4-hydroxyphenyl)cyclohexane; 4,4'-bis(4-hydroxyphenyl)
ether; 4,4'-dihydroxydiphenyl sulfone; 4,4'-dihydroxydiphenyl
sulfide; 4,4'-dihydroxydiphenyl ketone, and an adduct thereof with
an alkylene oxide. The adduct with an alkylene oxide includes an
adduct of a bisphenol compound (e.g., bisphenol A, bisphenol AD and
bisphenol F) with a C.sub.2-3alkylene oxide, e.g.,
2,2-bis-[4-(2-hydroxyethoxy)phenyl]propa- ne, diethoxylated
bisphenol A (bisphenol A ethoxylate, EBPA),
2,2-bis[4-(2-hydroxypropoxy)phenyl]propane, dipropoxylated
bisphenol A, and others. In the adduct with an alkylene oxide, the
mole number of the added alkylene oxide (a C.sub.2-3alkylene oxide
such as ethylene oxide and propylene oxide) is about 1 to 10 mol,
and preferably about 1 to 5 mol relative to each hydroxyl
group.
[0021] The hydroxycarboxylic acid includes, for example, a
hydroxycarboxylic acid such as hydroxybenzoic acid,
hydroxynaphthoic acid, hydroxyphenylacetic acid, glycolic acid and
hydroxycaproic acid, or a derivative thereof. Exemplified as the
lactone is a C.sub.3-12lactone such as propiolactone,
butyrolactone, valerolactone, and caprolactone (e.g.,
.epsilon.-caprolactone), and others.
[0022] Examples of the preferred copolymerizable monomer includes a
diol compound [e.g., a C.sub.2-6alkylene glycol (e.g., a linear
alkylene glycol such as ethylene glycol, trimethylene glycol,
propylene glycol and hexanediol), a polyoxyC.sub.2-4alkylene glycol
which has a repeating oxyalkylene unit of about 2 to 4 (e.g.,
diethylene glycol), and a bisphenol compound (e.g., a bisphenol
compound, or an alkylene oxide adduct thereof)], and a dicarboxylic
acid compound [e.g., C.sub.6-12aliphatic dicarboxylic acid (such as
adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic
acid), an asymmetrical aromatic dicarboxylic acid having carboxyl
groups as a substituent at asymmetric positions of the arene ring,
and 1,4-cyclohexanedimethanol]. Among these compounds, the
preferred one includes an aromatic compound, e.g., the alkylene
oxide adduct of a bisphenol compound (particularly bisphenol A),
and an asymmetrical aromatic dicarboxylic acid [e.g., phthalic
acid, isophthalic acid, and a reactive derivative thereof (e.g., a
lower alkyl ester such as dimethyl isophthalate (DMI)].
[0023] The proportion (modifying amount) of the copolymerizable
monomer is usually not more than 30 mol % (0 to 30 mol %). In the
copolymer, the proportion of the copolymerizable monomer may for
example be selected from a range of about 0.01 to 30 mol %, usually
about 1 to 30 mol % (e.g., about 1 to 20 mol %), preferably about 3
to 25 mol %, and more preferably about 5 to 20 mol % (e.g., about 5
to 15 mol %).
[0024] From the viewpoint of laser weldability, the melting point
of the PBT-series resin is not lower than 190.degree. C. (e.g.,
about 190 to 270.degree. C.), preferably about 200 to 260.degree.
C., and more preferably about 210 to 250.degree. C.
[0025] The PBT-series resin may be produced from a
co-polymerization of terephthalic acid or a reactive derivative
thereof, 1,4-butanediol, and if necessary a copolymerizable monomer
by a conventional manner, for example, transesterification and
direct esterification.
[0026] (B) Resin (Second Resin)
[0027] The resin (B) for improving laser weldability of the
PBT-series resin in combination with the PBT-series resin includes
a polycarbonate (PC)-series resin (b1), a styrenic resin (b2), a
polyethylene terephthalate (PET)-series resin (b3), and an acrylic
resin (b4). These second resins (B) may be used singly or in
combination. Incidentally, in combination with the polybutylene
terephthalate-series resin (A) and the resin (B), the resin
composition may form a polymer alloy.
[0028] (b1) Polycarbonate (PC)-Series Resin
[0029] The polycarbonate-series resin includes a polymer obtainable
through the reaction of a dihydroxy compound with phosgene or a
carbonic ester such as diphenyl carbonate. The dihydroxy compound
may be an alicyclic compound, and is preferably an aromatic
compound (in particular, a bisphenol compound). The dihydroxy
compound may be used singly or in combination.
[0030] The bisphenol compound includes a bisphenol compound
exemplified in the paragraph of the PBT-series resin (e.g., a
bis(hydroxyaryl)C.sub.1-6a- lkane; a
bis(hydroxyaryl)C.sub.4-10cycloalkane; 4,4'-dihydroxydiphenyl
ether; 4,4'-dihydroxydiphenyl sulfone; 4,4'-dihydroxydiphenyl
sulfide; and 4,4'-dihydroxydiphenyl ketone). The preferred
polycarbonate-series resin includes a bisphenol A-based
polycarbonate. The polycarbonate-series resin may be used singly or
in combination.
[0031] (b2) Styrenic Resin
[0032] As the styrenic resin, for example, there may be mentioned a
homo- or copolymer of a styrenic monomer (e.g., styrene,
vinyltoluene, .alpha.-methylstyrene); a copolymer of the styrenic
monomer and a vinyl monomer (e.g., an unsaturated nitrile (such as
(meth)acrylonitrile), an .alpha.,.beta.-monoolefinic unsaturated
carboxylic acid or acid anhydride or an ester thereof (such as a
(meth)acrylic acid ester, (meth)acrylic acid, and maleic
anhydride), a maleimide-series monomer (such as maleimide, an
N-alkylmaleimide, and N-phenylmaleimide)); a styrenic graft
copolymer; and a styrenic block copolymer. Examples of the
polystyrenic graft copolymer includes a resin in which styrene, and
acrylonitrile and/or methyl methacrylate are graft-polymerized to a
rubber component such as a polybutadiene, an acrylic rubber, a
chlorinated polyethylene, an ethylene-vinyl acetate copolymer, an
ethylene-propylene rubber, an ethylene-propylene-diene rubber and a
styrene-butadiene copolymer rubber (e.g., an ABS resin, and a MBS
resin). As the block copolymer, there maybe mentioned, for example,
a styrene-butadiene-styrene (SBS) block copolymer, a
styrene-isoprene block copolymer, a styrene-isoprene-styrene (SIS)
block copolymer, a hydrogenated styrene-butadiene-styrene (SEBS)
block copolymer, and a hydrogenated styrene-isoprene-styrene (SEPS)
block copolymer. These styrenic resins may be used singly or in
combination.
[0033] The preferred styrenic resin includes a polystyrene (GPPS)
and a styrene-(meth)acrylic ester copolymer (such as a
styrene-methyl methacrylate copolymer), a styrene-(meth)acrylic
acid copolymer, a styrene-maleic anhydride copolymer, a
styrene-acrylonitrile copolymer (AS resin), a graft copolymer in
which at least a styrenic monomer is graft-polymerized to a rubber
component [for example, a high impact polystyrene (HIPS), an ABS
resin, and a MBS resin] or a block copolymer (e.g., a SBS block
copolymer, a SIS block copolymer, a SEBS block copolymer, and a
SEPS block copolymer), and others.
[0034] (b3) Polyethylene Terephthalate (PET)-Series Resin
[0035] The polyethylene terephthalate-series resin includes a
homopolyester or a copolyester (a polyethylene terephthalate, a
polyethylene terephthalate copolyester) containing ethylene
terephthalate as a main unit (e.g., about 50 to 100% by weight,
preferably about 60 to 100% by weight, and more preferably about 75
to 100% by weight), and others.
[0036] As the copolymerizable monomer for the copolyester (an
ethylene terephthalate-series copolymer or a modified PET resin),
there may be mentioned a dicarboxylic acid other than terephthalic
acid, a diol other than ethylene glycol, a hydroxycarboxylic acid,
a lactone, and others. As these copolymerizable monomers,
copolymerizable monomers as exemplified in the paragraph of the
PBT-series resin may be used, respectively, in addition to
butanediol. The copolymerizable monomer may be used singly or in
combination.
[0037] The preferred copolymerizable monomer includes a monomer
exemplified in the paragraph of the PBT-series resin, for example,
a diol compound [e.g., a C.sub.3-6alkylene glycol (e.g., a linear
or branched alkylene glycol such as trimethylene glycol, propylene
glycol and butanediol), a polyoxyalkylene glycol, a bisphenol
compound or an alkylene oxide adduct thereof], a dicarboxylic acid
compound (e.g., a C.sub.6-12aliphatic dicarboxylic acid, an
asymmetrical aromatic dicarboxylic acid, and 1,4-cyclohexane
dimethanol).
[0038] In the copolymer, the proportion (modifying ratio) of the
copolymerizable monomer is about 1 to 30 mol %, preferably about 3
to 25 mol %, and more preferably about 5 to 20 mol %.
[0039] The PET-series resin may be produced by a copolymerization
of terephthalic acid, ethylene glycol, and if necessary a
copolymerizable monomer with a conventional manner, for example,
transesterification and direct esterification.
[0040] (b4) Acrylic Resin
[0041] The acrylic resin includes, for example, a homo- or
copolymer of (meth)acrylic monomer(s) (e.g., (meth)acrylic acid or
an ester thereof), a copolymer of (meth)acrylic monomer(s) and
other copolymerizable monomer(s), and others.
[0042] The (meth)acrylic monomer includes (meth)acrylic acid, a
(meth)acrylic ester [e.g., a C.sub.1-18alkyl ester of (meth)acrylic
acid such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl
(meth)acrylate and 2-ethylhexyl (meth)acrylate, a hydroxyalkyl
(meth)acrylate such as 2-hydroxyethyl (meth)acrylate and
2-hydroxyethyl (meth)acrylate, glycidyl (meth)acrylate],
(meth)acrylamide, (meth)acrylonitrile, and others.
[0043] Examples of other copolymerizable monomer include a styrenic
monomer (e.g., styrene, vinyltoluene, .alpha.-methylstyrene,
chlorostyrene, vinylnaphthalene, and vinylcyclohexane), a
polymerizable polycarboxylic acid (e.g., fumaric acid, and maleic
acid), a maleimide-series monomer (e.g., maleimide, an
N-alkylmaleimide, and N-phenylmaleimide), a diene-series monomer
(e.g., isoprene, 1,3-butadiene, 1,4-hexadiene, and
dicyclopentadiene), a vinyl-series monomer (e.g., a vinyl ester
such as vinyl acetate and vinyl propionate; a vinyl ketone such as
methyl vinyl ketone and methyl isopropenyl ketone; a vinyl ether
such as a vinyl isobutyl ether and vinyl methyl ether; a
nitrogen-containing vinyl monomer such as N-vinylcarbazole,
N-vinylpyrrolidone and N-vinylimidazole), and others. These
copolymerizable monomers may be used singly or in combination.
[0044] The preferred acrylic resin includes, for example,
apoly(meth)acrylic acid, apoly(meth)acrylic ester (e.g., a
poly(methyl methacrylate) (PMMA)), a methyl methacrylate-acrylate
copolymer, a methyl methacrylate-acrylic acid copolymer, and a
methyl methacrylate-styrene copolymer (MS resin).
[0045] Among these resins (B), the polycarbonate-series resin (b1)
and the polyethylene terephthalate-series resin (b3) are preferred,
and in particular, the polycarbonate-series resin (b1) is
preferred.
[0046] The proportion of the resin (B) relative to the polybutylene
terephthalate-series resin (A) may be suitably selected as far as
the resin composition does not deteriorate in laser weldability,
and for example, the former/the latter (weight ratio) is about
0.1/1 to 1.5/1, preferably about 0.20/1 to 1.2/1, and more
preferably about 0.25/1 to 1.2/1 (e.g., about 0.3/1 to 1.1/1). Such
a resin composition has a high transparency (or penetrability)
relative to a laser beam, and can be effectively fused to a shaped
article of a counterpart.
[0047] The resin composition may comprise a reinforcer (C). Such a
reinforcer (C) includes a fibrous reinforcer [for example, an
inorganic fiber (e.g., a glass fiber, an asbestos fiber, a carbon
fiber, a silica fiber, an alumina fiber, a silica-alumina fiber, a
zirconia fiber, a potassium titanate fiber, a silicon carbide
fiber, a whisker (e.g., a whisker of a silicon carbide, a whisker
of an alumina and a whisker of a silicon nitride)), and an organic
fiber (for example, a fiber formed from an aliphatic or aromatic
polyamide, an aromatic polyester, a fluorine-containing resin, an
acrylic resin such as a polyacrylonitrile, a rayon or the like)], a
plate-like reinforcer (for example, a talc, a mica, a glass flake,
and a graphite), a particulate reinforcer [for example, a glass
bead, a glass powder, a milled fiber (e.g., a milled glass fiber),
and a wollastonite]. Incidentally, the wollastonite may be any form
such as a plate-like, a columnar, and a fibrous form. The average
diameter of the fibrous reinforcer may for example be about 1 to 50
.mu.m (preferably about 3 to 30 .mu.m), and the average length
thereof may for example be about 100 .mu.m to 3 mm (preferably
about 500 .mu.m to 1 mm). Moreover, the average particle size of
the plate-like or particulate reinforcer may for example be about
0.1 to 100 .mu.m, and preferably about 0.1 to 50 .mu.m. These
reinforcers may be used singly or in combination.
[0048] Among these reinforcers, a reinforcer capable of
transmitting (or penetrating) a laser beam is preferred. Such a
reinforcer may be selected depending on the wavelength of the laser
beam. Examples of such a reinforcer include a glass-series or
vitreous reinforcer (e.g., a glass fiber, a glass flake, a glass
bead, and a glass powder). In particular, a glass fiber, for
example, a glass fiber having a high strength and rigidity (e.g.,
chopped strand), and others are preferred.
[0049] The proportion of the reinforcer (C) in the resin
composition is, for example, about 1 to 60% by weight, preferably
about 5 to 50% by weight, and more preferably about 10 to 45% by
weight.
[0050] To the resin composition may be added various additives, for
example, a stabilizer (e.g., an antioxidant, an ultraviolet ray
absorbing agent, and a heat stabilizer), a flame retardant, a
lubricant, a mold-release agent (or releasing agent), an antistatic
agent, a filler (e.g., an inorganic filler), a coloring agent such
as a colorant, a dispersing agent, and a plasticizer. Moreover, if
necessary, the resin composition may be used in combination with
other resin (e.g., a thermoplastic resin, and a thermosetting
resin).
[0051] The PBT-series resin composition of the present invention
may be a particulate mixture or a molten mixture (e.g., a pellet).
The resin composition of the present invention has a high
moldability, and ensures to produce a shaped article or shaped form
having a high mechanical strength and a high heat resistance. In
particular, the shaped article formed from the resin composition of
the present invention, in spite of being formed from a PBT-series
resin composition, is high in light transmittance (particularly
light transmittance relative to a laser beam) and suitable for
laser welding. For example, in a shaped article, having a thickness
of 3 mm, formed by injection-molding a PBT-series resin composition
containing a glass fiber (at a mold temperature of 400.degree. C.),
for a wavelength of 800 to 1100 nm the light transmittance is about
not less than 15% (e.g., about 17 to 70%), preferably about not
less than 18% (e.g., about 20 to 60%), and more preferably about
not less than 22% (e.g., about 25 to 50%). Further, since the resin
composition of the present invention is high in laser weldability,
the resin composition is useful for producing a shaped article to
weld through the use of a laser beam.
[0052] [Shaped Article]
[0053] The shaped article may be produced by subjecting the resin
composition comprising the PBT-series resin (A), the resin (B), and
preferably the reinforcer (C) to a conventional method, for
example, (1) a method comprising mixing each component, kneading
and extruding the resulting mixture into pellets with a uniaxial or
biaxial extruder, and molding the pellets, (2) a method comprising
once making pellets (master batch) different in formulation, mixing
(diluting) the pellets in a certain proportion, and molding the
resulting pellets to give a shaped article having a predetermined
formulation, or (3) a method comprising directly charging one or
not less than 2 of each component to give the composition, and
molding the composition with a molding machine. Incidentally, the
pellet may for example be prepared by melt-mixing components except
for a brittle or fragile component (such as a glass-series
reinforcer), and then mixing the brittle or fragile component with
the mixture.
[0054] The shaped article may be formed by melt-kneading the
PBT-series resin composition and molding with the use of a
conventional manner such as an extrusion molding, an injection
molding, a compression molding, a blow molding, a vacuum molding, a
rotational molding and a gas injection molding, usually with an
injection molding. Incidentally, the mold temperature on the
injection molding is about 23 to 90.degree. C., preferably about 23
to 60.degree. C., and more preferably about 30 to 50.degree. C.
[0055] The shape (or configuration) of the shaped article is not
particularly limited to a specific one. Since the shaped article is
bonded to a counterpart material (other shaped article formed from
a resin) through a welding by a laser, the shaped article is
usually formed of a shape having at least a contact surface (e.g.,
a flat surface), for example, a plate-like form. Moreover, the
shaped article of the present invention is high in transmittance
(or penetrability) relative to a laser beam, and the thickness of
the laser beam-transmitting site in the shaped article (the
thickness of the laser beam-transmitting direction) may be selected
from a wide range, for example, may be about 0.1 to 5 mm,
preferably about 0.1 to 3 mm (e.g., about 0.5 to 2 mm).
[0056] The light source of the laser beam is not particularly
limited to a specific one, and includes, for example, a dye laser,
a gas laser, (e.g., an excimer laser, an argon laser, a krypton
laser, and a helium-neon laser), a solid-state laser (e.g., a YAG
laser), a semiconductor laser, and others. As the laser beam, a
pulsed laser is usually employed.
[0057] Incidentally, the laser-scanning rate (or moving speed of a
laser-irradiation position on a sample) may be arbitrarily
selected. However, in the case where enough welding is required,
the laser-scanning rate is about 0 to 150 mm/second, preferably
about 0 to 100 mm/second, and more preferably about 0 to 50
mm/second, because there is a possibility that fast scanning rate
induces incomplete welding.
[0058] The shaped article is excellent in laser weldability, and
usually, the shaped article is preferably welded to a resin shaped
article as a counterpart by a laser beam. If necessary, the shaped
article may be also welded to other resin shaped article by other
heat-welding method, for example, a vibration welding, an
ultrasonic welding, and a hot plate welding.
[0059] In the shaped composite article of the present invention, a
shaped article (first shaped article) formed from the PBT-series
resin composition and a resin shaped article as a counterpart
(second shaped article, adherend) are welded and united by a laser
welding. For example, the shaped composite article may be obtained
as a united shaped form by the following manner: the first shaped
article and the second shaped article (particularly, at least
joining parts of both articles) are brought into contact with each
other (particularly, at faces of each joining parts), closely
contacted at each joining faces through partly fusing the interface
of the articles by a laser irradiation to be bonded or joined each
other with cooling, and finally united or connected to be the sole
shaped form. Use of the shaped article of the present invention for
such a shaped composite article ensures a high bonded strength by a
welding and such a bonded strength is as high as that of a
non-welded shaped article. Therefore, the present invention can
provide a shaped composite article firmly bonded without
substantial deterioration of the bonded strength due to a laser
welding. For example, assuming that the strength of the non-welded
member is taken as 100, a shaped composite article welded in a
welding strength of about 80 to 100 can be obtained.
[0060] The resin constituting the resin shaped article as the
counterpart is not particularly limited to a specific one, and
includes various thermoplastic resin, for example, an olefinic
resin, a vinylic resin, a styrenic resin, an acrylic resin, a
polyester-series resin, a polyamide-series resin, a
polycarbonate-series resin, and others. Among these resins, the
counterpart may comprise the same kind or type of resin as the
resin constituting the PBT-series resin composition (e.g., a
polyester-series resin such as a PBT-series resin and a PET-series
resin, a polycarbonate-series resin, a styrenic resin, and an
acrylicresin), or a composition thereof. For example, the first
shaped article and the second shaped article may be formed from the
PBT-series resin composition of the present invention,
respectively.
[0061] The adherend may contain an absorbent for a laser beam or a
coloring agent. The coloring agent may be selected depending on the
wavelength of the laser beam, and includes an inorganic pigment
[for example, a black pigment such as a carbon black (e.g., an
acetylene black, a lampblack, a thermal black, a furnace black, a
channel black, and Ketjen black), a red pigment (such as an iron
oxide), an orange pigment (such as a molybdate orange), and a white
pigment (such as a titanium oxide)], an organic pigment (e.g., a
yellow pigment, an orange pigment, a red pigment, a blue pigment,
and a green pigment), and others. These absorbents may be used
singly or in combination. As the absorbent, a black pigment or dye,
particularly a carbon black, may be usually employed. The average
particle size of the carbon black may be usually about 10 to 1000
nm, and preferably about 10 to 100 nm. The proportion of the
coloring agent is about 0.1 to 10% by weight, and preferably 0.3 to
5% by weight (e.g., about 0.3 to 3% by weight), relative to the
total amount of the adherend.
[0062] The irradiation (or impingement) of the laser beam is
usually conducted in the direction toward the second shaped article
from the first shaped article, and the first and the second shaped
articles are welded to each other by generation of heat in the
interface of the second shaped article containing the absorbent or
the coloring agent. Incidentally, if necessary, through the use of
a lens system, the contact surface between the first and the second
shaped articles may be welded by focusing the laser beam on the
interface.
[0063] The preferred embodiment of the present invention includes a
laser weldable PBT-series resin composition comprising a PBT-series
resin (A) and a polycarbonate (PC)-series resin (B) (and if
necessary, a reinforcer (C) capable of transmitting a laser beam).
The ratio (weight ratio) of the PC-series resin (B) relative to the
PBT-series resin (A) may be about 0.1/1 to 1.5/1. The PBT-series
resin (A) includes a PBT or a PBT-series copolymer modified with
(or containing) about not more than 30 mol % of a copolymerizable
monomer (e.g., a bisphenol compound or an adduct thereof with an
alkylene oxide, an asymmetrical aromatic dicarboxylic acid, and a
derivative thereof capable of forming an ester). The resin
composition may have a light transmittance of not less than 15% for
a wavelength of 800 to 1100 nm at a thickness of 3 mm in a shaped
article formed from the resin composition by an injecting
molding.
[0064] The further preferred embodiment of the present invention
includes a laser weldable PBT-series resin composition which
comprises at least one PBT-series resin (A) selected from the group
consisting of a PBT and a PBT-series copolymer modified with (or
containing) 1 to 20 mol % of a copolymerizable monomer, and a
PC-series resin (B) (and if necessary, a glass fiber (C)); wherein
the ratio (weight ratio) of the resin (B) relative to the
PBT-series resin (A) is 0.1/1 to 1.5/1, and the copolymerizable
monomer is at least one member selected from the group consisting
of phthalic acid, isophthalic acid, an adduct of bisphenol A with
an alkylene oxide, and a reactive derivative thereof.
[0065] The preferred embodiment of the present invention also
includes a shaped article formed from the resin composition; and a
shaped composite article comprising the shaped article, and a
counterpart shaped article formed from a resin, wherein the shaped
article is bonded to the counterpart shaped article through a
welding by a laser.
[0066] According to the present invention, the combination use of
the PBT-series resin and the specific resin ensures to provide a
composition and a shaped article which are excellent in laser
weldability even containing the PBT-series resin as a base, and to
obtain a shaped composite article having a high welding strength by
welding. Moreover, according to the present invention, the light
transmittance and welding strength of the PBT-series resin shaped
article can be increased.
INDUSTRIAL APPLICABILITY
[0067] The resin composition of the present invention has a high
laser weldability, and therefore the resin composition is useful
for producing a shaped article to be welded with the use of a laser
beam. Moreover, the shaped article of the present invention is
excellent in laser weldability, and is valuable for being subjected
to welding to a resin shaped article as a counterpart by a laser
beam welding. Since the obtained shaped composite article has a
high welding strength and less damages the PBT-series resin due to
the laser irradiation, the shaped composite article can be applied
for various applications, for example, an electric or electronic
device part, an office automation (OA) device part, a household
electrical appliance part, a mechanical device part, an automotive
part, and others. In particular, the shaped composite article can
be preferably utilized for an automotive electrical component or
part (e.g., various control units, and an ignition coil part), a
motor part, various sensor parts, a connector part, a switch part,
a relay part, a coil part, a transformer part, a lamp part, and
others.
EXAMPLES
[0068] The following examples are intended to describe this
invention in further detail and should by no means be interpreted
as defining the scope of the invention.
[0069] In Examples and Comparative Examples, the following
PBT-series resin (A), resin (B) and glass fiber (C) were used.
[0070] PBT-Series Resin (A)
[0071] (A-1) Polybutylene Terephthalate (Manufactured by Win Tech
Polymer Ltd., "DX2000")
[0072] (A-2) PBT Resin Modified with Dimethyl Isophthalate
(DMI)
[0073] In a reaction of terephthalic acid with 1,4-butanediol, 12.5
mol % of DMI was used as a copolymerizable component in place of
part of terephthalic acid (12.5 mol %), and a modified polybutylene
terephthalate was prepared.
[0074] (A-3) PBT Resin Modified with Diethoxybisphenol A (EBPA)
[0075] In a reaction of terephthalic acid with 1,4-butanediol, 10.0
mol % of EBPA was used as a copolymerizable component in place of
part of 1,4-butanediol (10.0 mol %), and a modified polybutylene
terephthalate was prepared.
[0076] Resin (B)
[0077] (B-1) Polycarbonate (PC) Resin (Manufactured by Teijin
Chemicals Ltd., "PANLITE L1225")
[0078] (B-2) Acrylonitrile-Styrene (AS) Resin (Manufactured by
Daicel Chemical Industries, Ltd., "CEVIAN N AP-20")
[0079] (B-3) Polyethylene Terephthalate (PET) Resin (Manufactured
by Teijin Ltd., "TR8580HP")
[0080] Glass Fiber (C)
[0081] A glass fiber having an average fiber diameter of 11 .mu.m
and an average fiber length of 3 mm was used.
Examples 1 to 24 and Comparative Examples 1 to 13
[0082] The PBT-series resin (A), the resin (B) and the glass fiber
(C) were kneaded by using a biaxial extruder (manufactured by Japan
Steel Works, Ltd., 30 mm.phi.) at 250.degree. C. in a proportion
shown in Tables 1 to 4 to prepare a pellet. Thus obtained pellet
was molded into a test piece "A" (7 cm in length, 1 cm in width and
3 mm in thickness) by an injection molding machine (manufactured by
Toshiba Corporation) at a cylinder temperature of 250.degree. C.
under a condition of a mold temperature shown in Tables.
[0083] Moreover, a test piece "B" to be welded to the test piece
"A" was produced in the same manner as the test piece "A" except
that 3 part by weight of a carbon master batch for coloring
(manufactured by Win Tech Polymer Ltd., trade name "2020B") was
used relative to 100 parts by weight of the pellet to color the
pellet. Incidentally, the test piece "B" acts as a heating element
in which heat is generated by a laser beam.
[0084] As shown in FIG. 1 and FIG. 2, the test piece "A" (3) and
the test piece "B" (4) were interposed and fixed between an acrylic
plate (5) and a metal plate (6) with a state where the test piece
"A" was partly superposed and put on the test piece "B". A laser
beam (2) from a light source (1) was focused and condensed on the
contact surface between the test pieces "A" and "B" in a line width
W (2 mm), and irradiated from the side of the test piece "A" (3) to
weld the test pieces with the use of a laser welding machine (FLS
iron) (manufactured by Japan Laser Corporation) under laser output
and scanning rate conditions shown in Tables.
[0085] Incidentally, in Examples and Comparative Examples shown in
Table 1, the irradiation was conducted by a laser beam of a
wavelength 810 nm.
[0086] Moreover, in Examples and Comparative Examples shown in
Tables 2 to 4, the irradiation was conducted by a laser beam of a
wavelength 940 nm with the use of a laser welding machine
manufactured by Leister Process Technologies ("MODULAS welding
system C type"), and a quarts glass plate instead of the acrylic
plate.
[0087] (1) Measurement of Welding Strength
[0088] The laser-welded test pieces "A" and "B" were pulled and
sheared by using a tensile tester (manufactured by Toyo Boldwin
Co., Ltd., "UTM-2.5T") at a rate of 5 mm/minute, and the welding
strength was determined.
[0089] (2) Light Transmittance
[0090] The light transmittance of the test piece "A" for a
wavelength of 940 nm was measured by using a spectrophotometer
(manufactured by JASCO Corporation, "V570").
[0091] The results of Examples and Comparative Examples are shown
in Tables 1 to 4.
1 TABLE 1 Comparative Examples Examples 1 2 3 4 5 6 7 8 9 1 2 3 (A)
PBT-series resin (parts by weight) (A-1) PBT resin 45 65 70 100
(A-2) PBT resin modified 45 40 40 35 45 65 70 with DMI (A-3) PBT
resin modified 45 with EBPA (B) Resin (parts by weight) (B-1) PC
resin 25 25 25 25 35 35 (B-2) AS resin 30 (B-3) PET resin 30 35 (C)
Glass fiber 30 30 30 30 30 30 30 0 0 30 30 0 (parts by weight)
(B)/(A) (weight ratio) 0.56/1 0.56/1 0.56/1 0.75/1 0.75/1 1.00/1
0.56/1 0.54/1 0.54/1 0/1 0/1 0/1 Mold temperature (.degree. C.) 40
40 40 40 40 40 40 40 40 40 40 40 Laser output (W) 34 34 34 34 34 34
34 34 34 34 34 34 Scanning rate (mm/sec.) 3 3 3 3 3 3 3 3 3 3 3 3
Light transmittance 25 30 30 22 23 25 31 30 35 12 13 14 (940 nm)
(%) Laser welding strength 27 31 30 31 31 32 30 11 12 0 0 0
(MPa)
[0092]
2 TABLE 2 Comparative Examples Examples 10 11 12 13 14 4 5 (A)
PBT-series resin (parts by weight) (A-1) PBT resin 49 45 70 (A-2)
PBT resin 45 35 45 70 modified with DMI (B) Resin (parts by weight)
(B-1) PC resin 21 25 25 (B-2) AS resin 25 (B-3) PET resin 35 (C)
Glass fiber 30 30 30 30 30 30 30 (parts by weight) (B)/(A) (weight
ratio) 0.43/1 0.56/1 0.56/1 1.0/1 0.56/1 0/1 0/1 Mold temperature
(.degree. C.) 40 40 40 40 40 40 40 Laser output (W) 24 24 24 24 24
24 24 Scanning rate (mm/sec.) 3 3 3 3 3 3 3 Light transmittance 23
25 30 25 17 12 13 (940 nm) (%) Laser welding strength 20 31 32 30
15 0 0 (MPa)
[0093]
3 TABLE 3 Comparative Examples Examples 15 16 17 18 19 6 7 8 9 (A)
PBT-series resin (parts by weight) (A-1) PBT resin 49 70 70 (A-2)
PBT resin modified 49 63 56 49 70 70 with DMI (B) Resin (parts by
weight) (B-1) PC resin 21 21 7 14 21 (C) Glass fiber 30 30 30 30 30
30 30 30 30 (parts by weight) (B)/(A) (weight ratio) 0.43/1 0.43/1
0.11/1 0.25/1 0.43/1 0/1 0/1 0/1 0/1 Mold temperature (.degree. C.)
80 80 80 80 80 80 80 80 80 Laser output (W) 23 23 27 27 27 23 23 27
27 Scanning rate (mm/sec.) 2 2 3 3 3 2 2 3 3 Light transmittance 18
22 17 20 22 11 13 11 13 (940 nm) (%) Laser welding strength 15 35
11 20 33 0 4 0 0 (MPa)
[0094]
4 TABLE 4 Comparative Examples Examples 20 21 22 23 24 10 11 12 13
(A) PET-series resin (parts by weight) (A-1) PBT resin 70 70 (A-2)
PBT resin modified 56 45 45 45 45 70 70 with DMI (B) Resin (parts
by weight) (B-1) PC resin 14 25 25 25 25 (C) Glass fiber 30 30 30
30 30 30 30 30 30 (parts by weight) (B)/(A) (weight ratio) 0.25/1
0.56/1 0.56/1 0.56/1 0.56/1 0/1 0/1 0/1 0/1 Mold temperature
(.degree. C.) 80 80 80 80 80 80 80 80 80 Laser output (W) 60 60 60
60 60 60 60 60 60 Scanning rate (mm/sec.) 20 20 50 100 150 20 20 50
50 Light transmittance 20 24 24 24 24 11 13 11 13 (940 nm) (%)
Laser welding strength 25 28 23 15 14 0 0 0 0 (MPa)
[0095] In Examples, the transmittance relative to the laser beam
and welding strength were high, and the welding strength was
improved. On the other hand, in Comparative Examples, any samples
failed to be laser-welded, or showed remarkably low laser
weldability.
* * * * *