Patent Grant
7053140
The instant invention pertains to thermoplastic resin compositions containing black colorants and suitable for laser welding. More particularly the invention relates to such compositions having as colorants mixtures of amine salts of anthraquinone and monoazo complex dyes.
It is known in the art to join together two articles made of resins (and respectively opaque and transparent) by positioning them in contact with each other, transmitting a predetermined amount of laser beam focused on the junction of them and causing the junction portion to be melted and joined together (“laser welding”). Several advantages flow from laser welding versus conventional methods of joining plastic parts. For example, laser welding is widely known for its simple operation, labor savings, improvement of productivity, clear joints, and reduction of production cost. It is useful in various applications including the preparation of molded articles, including hollow shapes, in automobile industries and electric and electronic industries. Recently, work has intensified in the area of blends of thermoplastic resin and a colorant containing an organic dye or pigment. Better control of the conversion of laser energy to heat is achieved by the addition of such colorants to the resins. Laser beams penetrate through transparent articles positioned closer to the laser beam source, and are largely absorbed in the opaque article, which has a relatively higher absorption coefficient in comparison with the aforementioned transparent article. Careful attention to the amount of the colorants therein results in the junction portion being melted and the articles joined together.
See for example Japanese Published (Koukoku) Patent No.62-49850 and Japanese Published (Koukoku) Patent No.5 (93)-42336. Other resin compositions associated with the laser welding are described in U.S. Pat. No. 5,893,959 which discloses transparent and opaque workpiece parts welded together by a laser beam along a joining zone. Both parts contain black dye pigments such as carbon black to cause them to offer a substantially homogenous visual impression even after welding.
Other illustrations of the laser welding of compositions are found in U.S. Pat. No. 5,893,959. For example, the color of the thermoplastic components may be black (carbon black or nigrosine) which is commonly and widely used in the automobile industry among other applications. However, carbon black and nigrosine cannot transmit a laser beam with a main wavelength in the infra-red region (1200 nm to 800 nm), such as Nd:YAG laser and a diode laser, both of which are of wide use in industries.
Surprisingly, it has now been found that thermoplastic resin compositions both black in appearance can be used for laser-welded molded articles for both the transparent and opaque parts subjected to the laser beam. A significantly improved transmission to near-infrared light of the laser beam, with excellent and balanced heat-resistance and mechanical properties as required in automobile applications, is achieved by including a specific weight percentage of black dyes comprising a mixture of amine salts of anthraquinone dyes formed by reacting anthraquinone acid dyes.
Using these components, thermoplastic resin compositions can be utilized for laser welding and exhibiting improvements in moldability, solubility in the thermoplastic resin, bleeding- and blooming-resistance as well as transparency to the wavelength of a laser beam and resistance to chemicals.
This invention relates to thermoplastic compositions for laser welding comprising 1) thermoplastic resin and, 2) laser-transmitting black colorant comprising amine salts of anthraquinone dye and monoazo complex dye.
This invention relates to improved thermoplastic resin compositions for laser welding comprising thermoplastic resin, and at least one black dye comprising a mixture of (i) amine salts of anthraquinone dyes of formula [I] or formula [II] and (ii) monoazo complex dye of formula [III]. Formula [I] is as follows:
wherein X is O or NH, and R9 to R13, which may be the same or different, are independently selected from the group consisting of H, alkyl, aryl, alkenyl, alkoxy, amino, N-alkylamide, N-arylamide, hydroxy, halogen atom, acyl, acyloxy, acylamide, acyl-N-alkylamide, carboxyl, alkoxycarbonyl, or sulfonyl, and at least one of R1 to R8 and R9 to R13 is sulfonyl group.
wherein R47 to R52, which may be the same or different, are independently selected from the group consisting of H, alkyl, aryl, alkenyl, alkoxy, amino, N-alkylamide, N-arylamide, hydroxy, halogen atom, acyl, acyloxy, acylamide, acyl-N-alkylaminde, carboxyl, alkoxycarbonyl, or sulfonyl, and at least one of R47 to R52 is of sulfonyl; and formula J in formula [II] is selected from formula [II-a] or formula [II-b] and binds two anthraquinone.
or
wherein R53 to R54, which may be the same or different, are independently selected from the group consisting of alkyl (having 1 to 8 carbon atoms) or hydrogen,
and wherein (F)h+ represents ammonium ion or a cation derived from an organic amino compounds or a basic dye wherein h is 1 or 2, m4 is an integer from 1 to 4 and K4 is the ratio of m4/h. The monoazo complex dye of formula [III] is as follows:
By using these components, thermoplastic resin compositions are obtained for laser welding having improved moldability, solubility in the thermoplastic resin, bleeding- and blooming-resistance, and resistance to chemicals. Improvements in transparency to wavelength of a laser beam are also discussed, particularly at wavelengths exceeding 800 nm by mixing the dye salts mentioned of the formula [I] or formula [II] with monoazo complex dyes of the formula [III] at predetermined weight ratios. Particularly, the mixture serves to significantly improve transmittance at diode laser beam wavelength than that by monoazo complex dyes of formula [III] alone. These mixtures improve at the diode laser beam wavelength much more than that observed with the monoazo dye alone. See generally, WO01/58997 A1, for a discussion of thermoplastic resins and monoazo complex dyes. Therefore they are of interest in industrial diode laser welding.
The amine salts of anthraquinone dyes used as one of components comprised in colorant in the invention exhibits colors of blue, violet or green and the monoazo complex dyes comprised in the colorants used in the invention are black dyes
The invention will be better understood upon having reference to the drawings herein.
The aforementioned dye salts of the desired structure represented by formula [I] or formula [II] used in the invention are prepared by commonly known methods, conveniently by reacting anthraquinone dyestuff with organic amine in a solvent. Mixtures of amine salts of anthraquinone dyes are formed by reacting anthraquinone acid dyes with organic amine, particularly sulfonyl group contained the dye reacting with ammonium salts from organic amine.
Suitable amines for use in producing the above-mentioned anthraquinone dyes in dyestuffs include aliphatic amine, alicyclic amine, alkoxyalkyl amine, amine having alkanol, diamine, amine of guanidine derivatives, and aromatic amine.
Basic dyes listed in the color index and useful in the instant invention include,
Examples of anthraquinone acid dyes which are useful in preparation of the dye salts of formula [I] used as colorant comprised in the compositions of the invention are given below in Tables 1-1 and 1-2. Descriptions in the left hand column (such as “I-2” and “I-13”) will assist the reader in understanding discussions about specific dye salts later in the description.
Examples of anthraquinone acid dyes which are useful in preparation of the dye salts of formula [II] used as colorants in the compositions of the invention are given below in Table 2.
Representative momoazo complex dyes represented by the formula [III] have a number of characteristics associated with them. For example, suitable cations for use in the monoazo complex dyes are H+; cations of alkali metal, ammonium ion, cations of organic amine including aliphatic primary, secondary and tertiary amines, and quaternary ammonium ion.
Suitable amines for use in producing the above-mentioned monoazo complex dyes and common in dyestuffs include aliphatic amine, alicyclic amine, alkoxyalkyl amine, amine having alkanol, diamine, amine of guanidine derivatives, and aromatic amine.
Suitable metals for producing the above-mentioned monoazo complex dyes include metals having ionic valency from 2 to 4, more preferably trivalent metal such as Cr, Fe, or bivalent metal such as Cu.
Examples of the metal azo complex dyes of formula [III] are identified below in Tables 3 and 4. These are classified as formulas [II-a] and [III-b] respectively.
Pro. Ex. No.=Product Example Number
Examples of the black dyes containing a mixture of the dye salts of formula [I] or formula [II] and the metal azo complex dyes of formula [III] are below:
The anthraquinone dye salt of formula [I-21]: the monoazo complex dye of the following formula [III-1] in a weight ratio of 1:1.
The anthraquinone dye salt of formula [I-21]: the monoazo complex dye of the following formula [III-1] in a weight ratio of 3:1.
The anthraquinone dye salt of formula [I-6]: the monoazo complex dye of the following formula [III-1] in a weight ratio of 2:1.
The anthraquinone dye salt of formula [I-23]: the monoazo complex dye of the following formula [III-5] in a weight ratio of 2:1.
The anthraquinone dye salt of formula [II-8]: the monoazo complex dye of the following formula [III-1] in a weight ratio of 3:1.
The anthraquinone dye salt of formula [I-5]: the monoazo complex dye of the following formula [III-1]: anthraquinone yellow dye of the following formula [a] in a weight ratio of 4:3:1.
The anthraquinone dye salt of formula [I-21]: the monoazo complex dye of the following formula [III-1]: perinone red dye of the following formula [b] in a weight ratio of 6:3:1.
The anthraquinone dye salt of formula [I-21]: the anthraquinone dye salt of formula [II-5]: the monoazo complex dye of the following formula [III-14] in a weight ratio of 2:2:1.
The thermoplastic resins for use in the inventive compositions include polyamides, polyesters, and the like as are commonly used in making a molded product. As the examples of the polyamide resins utilized in the present invention, condensation products of dicarboxylic acids and diamines, condensation products of aminocarboxylic acids and ring-opening polymerization products of cyclic lactams can be cited. As examples of dicarboxylic acids, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, isophthalic acid and terephthalic acid can be cited. As examples of diamines, tetramethylene diamine, hexamethylene diamine, octamethylene diamine, nonamethylene diamine, dodecamethylene diamine, 2-methylpentamethylene diamine, 2-methyloctamethylene diamine, trimethylhexamethylene diamine, bis(p-aminocyclohexyl)methane, m-xylene diamine and p-xylene diamine may be cited. As the example of aminocarboxylic acid, 11-aminododecanoic acid can be cited. As the examples of cyclic lactam, caprolactam and laurolactam can be cited. As the specific examples of condensation products and ring-opening polymerization products, aliphatic polyamides such as nylon 6, nylon 66, nylon 46, nylon 610, nylon 612, nylon 11, nylon 12, semi-aromatic polyamides such as polymetaxylene adipamide (nylon MXD6), polyhexamethylene terephthalamide (nylon 6T), polyhexamethylene isophthalamide (nylon 6I) and polynonamethylene terephthalamide (nylon 9T), and copolymers and mixtures of these polymers can be cited. As the examples of the copolymers, nylon 6/66, nylon 66/6I, nylon 6I/6T and nylon 66/6T can be cited.
A wide range of common polyester molding compositions useful for blending with colorants in the practice of the present invention are know in the art. These include polymers which are, in general, condensation products of dicarboxylic acids and diols. Dicarboxylic acids can be selected from the group consisting of adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and diphenyl dicarboxylic acid, and diols can be selected from the group consisting of ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, cyclohexanediol, and bisphenol. A. Preferred polyesters include polyethylene terephthalate (PET), polypropylene terephthalate (3GT), polybutylene terephthalate (PBT), polyethylene 2,6-naphthalate (PEN), polycyclohexane dimethylene terephthalate (PCT) and copolymers and mixtures thereof. As the examples of the copolymers, some of dicarboxylic acids or some of diols can be added to the condensation products. Polyester polymers may be copolymerized a little amount of components like trimesic acid, trimellitic acid, pyromellitic acid, glycerol, and pentaerythritol which have more than 3 functional groups.
Additional other polymers such as polycarbonate can also be presented, provided that the essential characteristics of the composition of the present invention are not substantially altered.
The mixture of the amine salts of anthraquinone dyes of formula [I] or formula [II] with the monoazo complex dyes of the formula [III] is present in amount of from 0.01 to 1% by weight when the composition comprises polyamide 6 as at least the major component of the polyamide resin composition.
The ratio of amount of the amine salts of anthraquinone dyes of formula [I] or formula [II] to that of monoazo complex dyes of the formula [III] may be specialized for applications requiring different properties associated with the laser welding. Particularly, the preferable ratio of amount of them is from 5:1 to 1:1. If the ratio of amount of them is more than 5:1 (in other words if the amount of the amine salts of anthraquinone dyes is too much), there cannot obtain black colorant as colored resin compositions. On the other hand, if the ratio of amount of them is less than 1:1 (in other words if the amount of the monoazo complex dyes is too much), transmittance in diode laser beam wavelength (808 nm) is deteriorate.
The composition of the present invention may contain an inorganic filler or reinforcing agent that includes, for example, fibrous reinforcement such as glass fiber and carbon fiber, glass flakes, glass beads, talc, kaolin, wollastonite, silica, calcium carbonate, potassium titanate and mica. Glass fiber and glass flakes are a preferred selection. Glass fibers suitable for use in the present invention are those generally used as reinforcing agents for thermoplastic resins and thermosetting resins. The preferred amount of glass fiber in the resin composition of the present invention is from about 5 to about 120 parts by weight, with respect to 100 parts by weight of the thermoplastic resin. If it is under 5 weight percent, it would be difficult to give sufficient reinforcement from the glass fiber, and if it is over 120 weight percent, it would have poor processibility and poor transparency to laser. It is preferable to use about 5 to about 100 weight percent, and particularly preferable at about 15 to about 85 weight percent.
One or more optional compounds selected from a wide variety of compounds tailored for different applications of the resin compositions can be contained in the composition according to the present invention, as is understood among those having skill in the art.
Typically, additive compounds can include flame retardants, impact modifiers, viscosity modifiers, heat resistance improvers, lubricants, antioxidants and UV-and other stabilizers. The thermoplastic resin compositions of the present invention may have such additive compounds in suitable amounts so as not to harm characteristic properties of the composition.
In the present invention, thermoplastic resin compositions are provided that are suitable for laser welding, including transparent articles for laser beam transmission to achieve welding together with the opaque article for laser beam absorption. Suitable opaque articles and its compositions are described for example in DE-A-4432081.
The present invention is illustrated by the following examples and comparative examples.
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTELS® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of amine salt of anthraquinone dye of formula [I-21] (0.40 g) with monoazo complex black dye represented by the following formula [III-1] (0.40 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 250° C. Mold temperature was 60° C. Good and uniformly black appearance and surface gloss without color shading of the specimens were observed.
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTELS® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of amine salt of anthraquinone dye of formula [I-21] (0.40 g) with monoazo complex black dye of the following formula [III-2] (0.40 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 250° C. Mold temperature was 60° C. Good and uniformly black appearance and surface gloss without color shading of the specimens were observed.
400 grams of (unreinforced) Nylon 66 ZYTEL101 pellets (available from E.I. DuPont de Nemours and Co.) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of amine salt of anthraquinone dye of formula [II-8] (0.40 g) with monoazo complex black dye represented by the following formula [III-1] (0.40 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 290° C. Mold temperature was 60° C. Good and uniformly black appearance and surface gloss without color shading of the specimens were observed.
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTELS® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of anthraquinone green dye of the following formula [c] (0.40 g) with monoazo complex black dye of the formula [III-1] (0.40 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 250° C. Mold temperature was 60° C. Black appearance of the specimens were observed.
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTEL® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of anthraquinone violet dye of the following formula [d] (0.40 g) with monoazo complex black dye (C.I. Acid Black 52 diphenylguanidine salts) (0.40 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 250° C. Mold temperature was 60° C. Good and uniformly black appearance and surface gloss without color shading of the specimens were observed.
Transmittance (T) in the range of 400 nm to 1200 nm of the test plates with laser beams having respective wavelengths of 940 nm (Semiconductor laser) and 1064 nm (YAG laser) was measured using a U-3410 spectrometer producted by Hitachi with 60 φ sphere photometer for wavelength from ultraviolet to near-infrared. The ratio (TA) of transmission with 940 nm:transmission with 1064 nm, the ratio (TB) of transmission with 940 nm:tarnsmission of natural resin are determined and compared between the examples and the ratio (TC) of transmission with 1064 nm:tarnsmission of natural resin are determined and compared between the examples.
Appearance of the test plates were evaluated by measuring Reflection Density (OD) of the test plates by Refelection Density meter TR-927 produced by Macbeth. Test plates having higher OD values are judged to have better surface smoothness and rich in gloss.
Each test plate was exposed to Xenon Weather Meter (produced by Toyo Seiki K.K., trade name: AtlasCI-4000) for 150 hours according to the following condictions, the amount of color fading and discoloration ΔE between “before” and “after” light irradiation was determined and measured using a colorimeter (produced by Juki, trade name: JP 7000).
Conditions of Light Resistance Test Procedure
The test plate having greater ΔE are judged to have greater discoloring and fading.
The amount of color fading and discoloration ΔE between before and after each test plate being placed and kept in an oven at 160° C. for 15 days was determined and measured using a colorimeter (produced by Juki, trade name: JP 7000).
The amount of color fading and discoloration ΔE between before and after each test plate being placed and kept in a thermoregulator at 80° C. (a humidity was 95%) for one week was determined and measured using a colorimeter (produced by Juki, trade name: JP 7000).
The amount of color fading and discoloration ΔE between before and after each test plate being immersed in ethyleneglycol and made airtight, then kept in thermoregulator at 40° C. for 48 hours was determined and measured using a colorimeter (produced by Juki, trade name: JP 7000).
The test plate having greater ΔE are judged to have greater discoloring and fading.
The results are set forth in the following Table 5.
This testing demonstrates that Examples A, B and C showed as high transmittance as a natural resin at a main wavelength in infra-red region (800 nm to 1200 nm). In Examples A, B and C, thermal, solubility and moisture resistances were good, compared with Comparative Examples D and E. Because Comparative Examples D and E including a neutral anthraquinone have property to dissolve from the test piece in ethylenglycol and have high possibility to discolor in rich humid atmosphere.
In Example F, G and Comparative Example H, we inspected the influence of the transmittance is inspected against the ratio of amine salt of anthraquinone dye to monoazo complex black dye.
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTEL® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of amine salt of anthraquinone dye of formula [I-21] (0.53 g) with monoazo complex black dye represented by the following formula [III-1] (0.27 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 250° C. Mold temperature was 60° C. Good and uniformly black appearance and surface gloss without color shading of the specimens were observed.
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTEL® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with a mixture of amine salt of anthraquinone dye of formula [I-21] (0.60 g) with monoazo complex black dye represented by the following formula [III-1] (0.20 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C the product name ZYTEL® 7301) and dyes were dry-blended with the amount described on the table 7. The blended material was molded into test pieces for laser welding, with dimension illustrated as
Laser welding was conducted using two pieces of the test pieces described above, combined as illustrated in
In
400 grams of (unreinforced) Nylon 6 ZYTEL pellets (available from E.I. DuPont de Nemours and Co., under the product name ZYTEL® 7301) were dried under vacuum at 120° C., for more than 8 hours, then mixed with monoazo complex black dye represented by the following formula [III-1] (0.80 g) in a stainless tumble mixer with stirring for one hour. The mixture was then injection molded to form the injection molded test specimens (whose sizes are 48 mm×86 mm×3 mm) using K50-C produced by Kawaguchi Steel K.K. and the cylinder temperature was set to 250° C. Mold temperature was 60° C. Good and uniformly black appearance and surface gloss without color shading of the specimens were observed.
Table 6 provides a comparison of Examples F, G and Comparative Example H.
Laser Welding Test
Pellets of unreinforced nylon 6 (available from E.I. DuPont de Nemours and Co., under
This application claims the benefit of U.S. Provisional Application No. 60/247,948, filed Nov. 13, 2000, and is a continuation of U.S. patent aplication Ser. No. 10/066,906, filed Nov. 13, 2001 now abandoned.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4944768 | Balliello et al. | Jul 1990 | A |
| 5893959 | Muellich | Apr 1999 | A |
| Number | Date | Country |
|---|---|---|
| WO 0158997 | Aug 2001 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20040067378 A1 | Apr 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60247948 | Nov 2000 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10066906 | Nov 2001 | US |
| Child | 10673012 | US |
