JP2001011326A - Resin composition for color marking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition capable of carrying out excellent color marking by irradiation of laser beams. SOLUTION: This resin compositon comprises a thermoplastic resin, (a) a dye or a pigment having high absorptivity for laser energy and (b) a dye or a pigment having a color different from that of the component (a) and low absorptivity for the above laser energy and (c) a fatty acid metal salt. For example, (a1) a black pigment having >=0.8 absorbance and (a2) a nonblack pigment having >=0.8 absorbance can be used as the component (a). For example, an organic dye or an organic pigment having <=0.6 absorbance can be used as the component (b). A resin composition, etc., comprising (A) an acrylic resin and (B) a styrene-based resin in (20/80) to (80/20) weight ratio (A)/(B) of the components (A) to (B) can be used as the thermoplastic resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for color marking capable of forming a chromatic (color) marking by irradiating a laser beam, and particularly to a resin composition having extremely excellent color marking properties and being recyclable and capable of being molded. The present invention relates to an inexpensive resin composition for color marking which is excellent in processability and impact resistance.

[0002]

2. Description of the Related Art After molding a resin, printing of characters, designs, figures and the like on the surface of the molded article is widely and generally performed. It has been known. For example, there are various methods from those using paint such as tampo printing and impregnated printing to printing by laser beam irradiation (hereinafter referred to as laser marking). The former method, which uses a paint, is the most common, but has the disadvantage that processing costs are high, environmental pollution by solvents is a concern, and recycling is difficult.

[0003] On the other hand, laser marking is inexpensive and efficient because the process is simpler than the method using paint.
Since it has advantages such as excellent durability of the printing section, it has extremely high industrial value. Therefore, in recent years, various techniques regarding laser marking have been proposed. In recent years, the price of the laser marker itself, which is a processing machine, has decreased, and the initial cost has also decreased. For this reason, in recent years, various proposals have been made regarding laser marking. For example, there has been disclosed a technique of marking a resin molded product surface by mixing a resin with a filler capable of being changed in color by laser irradiation (Japanese Patent Application Laid-Open No. 56-59926).
No.).

[0004] In addition, resins such as poly (methyl methacrylate) and polyacetal, which quantitatively become monomer components by thermal decomposition, can be easily white-marked or light-colored by heat caused by laser irradiation. (Japanese Patent Publication No. 2-47314).

On the other hand, in the case of a styrene resin such as polystyrene, high-impact polystyrene, ABS resin, MBS resin, and AS resin, heat generated by a laser causes decomposition into monomers, The decomposition is not quantitative, but instead is carbonized.
Whitening or light-colored marking is difficult because the first occurrence occurs.

In order to obtain chromatic color markings, Japanese Patent Application Laid-Open Nos. 7-165979 and 7-27
JP-A-8446 and JP-A-8-127175 propose the use of pigments and dyes as additives, but the clarity of color marking is insufficient.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin composition for color marking capable of performing extremely excellent color marking by irradiating a laser beam, and a molded article composed of the resin composition. Is to do.

Another object of the present invention is to provide a resin composition for color marking, which is recyclable, has excellent moldability and impact resistance, and is inexpensive, and a molded article composed of this resin composition. Is to do.

It is still another object of the present invention to provide a laser marking method capable of performing extremely excellent color marking by irradiating a laser.

[0010]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, when a molded article obtained from a resin composition containing a specific dye / pigment and a fatty acid metal salt is irradiated with a laser beam, The present inventors have found that extremely excellent color marking is possible, and have completed the present invention.

That is, the resin composition for color marking of the present invention comprises a thermoplastic resin, (a) a dye / pigment having a high absorption for laser energy, (b) a color different from that of the component (a), and It contains a dye / pigment having low absorption for laser energy and (c) a fatty acid metal salt, and is capable of color marking by irradiation with a laser beam. As the component (a), for example, (a1) an absorbance of 0.
8 or more black pigments, (a2) non-black pigments having an absorbance of 0.8 or more can be used, and as the component (a1), carbon black, graphite, titanium black, black iron oxide and the like can be used, and the component (a2) For example, a cobalt-based blue pigment, a chromium-based green pigment, or the like can be used. As the component (b), an organic dye or pigment having an absorbance of 0.6 or less can be used. The thermoplastic resin can be composed of (A) an acrylic resin and (B) a styrene resin, and the ratio of (A) and (B) is (A) / (B) = 20/80 to 80 / 20
(Weight ratio) of a resin composition or the like can be used.

[0012] The present invention also includes a molded article composed of the resin composition and a method of performing color marking on the molded article.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Since the resin composition of the present invention contains specific dyes and pigments and a fatty acid metal salt in a thermoplastic resin, extremely excellent color marking can be obtained.

[Thermoplastic resin] As the thermoplastic resin,
When irradiated with a laser, it is not particularly limited as long as it is a thermoplastic resin capable of marking with higher brightness than the background color,
Various thermoplastic resins can be used. As the thermoplastic resin, for example, acrylic resin, styrene resin, olefin resin (polyethylene, polypropylene, etc.), vinyl resin (vinyl chloride resin, vinylidene chloride resin,
Fluororesin, vinyl acetate resin, ethylene-vinyl acetate copolymer, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinyl acetal, etc., polyamide resin (nylon 6, nylon 66, nylon 61)
0, nylon 11, nylon 12, nylon 612, nylon 6/66, nylon 6/11), polyester resin (poly C _2-4 alkylene terephthalate, poly C)
_2-4 alkylene naphthalate, liquid crystalline polyester, etc.), polyacetal resins, thermoplastic polyurethane resins, polyether resins, polyketone resins, polyphenylene oxide resins, and the like. Further, the thermoplastic resin of the present invention also includes a phenoxy or epoxy resin or an imide resin. In the resin composition of the present invention, the content of these thermoplastic resins is at least 10% by weight.
It is. These resins may be used alone or in combination, alone or in combination of two or more.

(A) Acrylic resin (A) The acrylic resin contains at least one monomer selected from acrylic monomers, for example, (meth) acrylic acid and (meth) acrylate. Homopolymers or copolymers included as a body are included. Acrylic resin is a laser beam (for example, wavelength 1064n).
When irradiated with m), it has a function of foaming and exhibiting color marking on the surface of the molded article.

(Meth) acrylic acid esters include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, t-butyl acrylate,
Hexyl acrylate, 2-ethylhexyl acrylate,
And alkyl (meth) acrylates such as methacrylates corresponding thereto [eg, C _1-10 alkyl (meth) acrylate], 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate And the like, hydroxyalkyl (meth) acrylate, glycidyl (meth) acrylate, and the like. Among these monomers, C _1-6 alkyl (meth) acrylate [particularly, C _1-4 alkyl (meth) acrylate such as methyl methacrylate and butyl acrylate], particularly methyl methacrylate, can be preferably used. . These (meth) acrylates can be used alone or in combination of two or more.

The copolymer may contain a monomer other than the acrylic monomer as a constituent monomer. Such a monomer may be any monomer that can be copolymerized with an acrylic monomer, and examples thereof include a vinyl ester monomer such as vinyl acetate, a styrene monomer, and a vinyl cyanide monomer. Monomers, maleic anhydride and imide monomers.

The acrylic resin may contain a rubber component as a constituent. Examples of the rubber component include diene rubber components (polybutadiene, butadiene-styrene copolymer, polyisoprene, butadiene-acrylonitrile copolymer, isobutylene-isoprene copolymer, etc.), ethylene-propylene rubber, acrylic rubber (polybutyl acrylate, etc.) ), Urethane rubber, silicone rubber, butyl rubber and the like can be used. The rubber component can be contained in the acrylic resin by a blending method, copolymerization (graft polymerization, block polymerization, or the like).

Preferred acrylic resins include polymethyl methacrylate; methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate-C _1-4 alkyl ester copolymer, and methyl methacrylate-styrene copolymer. Examples include polymers containing methyl methacrylate as a constituent monomer, such as polymers and methyl methacrylate-butadiene-styrene copolymer (MBS resin). Among these, polymethyl methacrylate and a methyl methacrylate-methyl acrylate copolymer are particularly desirable in terms of balance between color marking properties, mechanical strength, cost, and compatibility with a styrene resin. Acrylic resins can be used alone or in combination of two or more.

The number average molecular weight of the acrylic resin is, for example, about 50,000 to 150,000, preferably 6
It is about 0000 to 120,000. If the number average molecular weight is less than 50,000, the impact resistance tends to decrease,
Further, since the compatibility with the styrene-based resin is insufficient, the resin composition is liable to cause a reduction in strength and an appearance defect such as a flow mark. On the other hand, when the number average molecular weight exceeds 150,000, the melt viscosity of the resin composition becomes too high, and the moldability tends to decrease.

The acrylic resin can be produced by polymerizing the above monomers by various polymerization methods, for example, emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like.

(B) Styrene resin The (B) styrene resin may contain at least one styrene monomer as a constituent monomer, and may be a homopolymer or a copolymer. You may. Styrene-based resin does not exhibit color marking properties by itself, but when combined with acrylic resin, the color marking properties of acrylic resin can be expressed with a lower energy laser beam compared to acrylic resin alone. And has a marked marking-promoting effect. Further, the styrene resin has excellent compatibility with the acrylic resin, and also has a function of imparting high impact properties and excellent moldability.

The styrene monomers include styrene, alkyl-substituted styrene (eg, o-methylstyrene, m-methylstyrene, p-methylstyrene, etc.), and halogen-substituted styrene (eg, o-chlorostyrene, p-chlorostyrene). Styrene, o-bromostyrene, etc.), α-alkyl-substituted styrenes substituted with an alkyl group at the α-position (eg, α-methylstyrene, α-ethylstyrene, etc.). Of these, styrene, vinyl toluene, α-methylstyrene and the like are usually used.

The styrenic resin may be a copolymer of the styrenic monomer and a copolymerizable monomer. Examples of the copolymerizable monomer include a vinyl cyanide monomer, maleic anhydride, an imide monomer, and the acrylic monomer. Vinyl cyanide-based monomers include acrylonitrile, methacrylonitrile, and the like. The imide-based monomers include N-alkylmaleimides (eg, N-methylmaleimide, N-ethylmaleimide, etc.), N-cycloalkylmaleimides (eg, N-
Cyclohexylmaleimide), N-arylmaleimide [eg, N-phenylmaleimide, N- (2-methylphenyl) maleimide, etc.]. Of these, acrylonitrile, maleic anhydride, and imide monomers (especially acrylonitrile) are usually used. The amount of the copolymerizable monomer (such as acrylonitrile) in all the monomers is 1 to 50% by weight, preferably 5 to 40% by weight.
%, More preferably in the range of about 8 to 30% by weight.

The styrenic resin may contain a rubber component. The rubber component can be contained in the styrene-based resin by a blending method, copolymerization (graft polymerization, block polymerization, or the like). As the rubber component, diene rubbers (polybutadiene, butadiene-styrene copolymer, polyisoprene, butadiene-acrylonitrile copolymer, isobutylene-isoprene copolymer, etc.), ethylene-propylene rubber, acrylic rubber (polybutyl acrylate, etc.) , Ethylene-vinyl acetate copolymer, urethane rubber, silicone rubber, butyl rubber and the like. The content of the rubber component in the rubber-modified styrenic resin is
For example, 5 to 70% by weight, preferably 10 to 50% by weight,
More preferably, it is about 20 to 40% by weight.

Preferred styrene resins include polystyrene (GPPS); poly (α-methylstyrene); styrene-acrylonitrile copolymer (AS resin); impact-resistant polystyrene (HIPS), styrene-butadiene copolymer, and styrene. -Acrylonitrile-butadiene copolymer (ABS resin), rubber-modified styrene resin such as α-methylstyrene-modified ABS resin, imide-modified ABS resin; styrene-maleic anhydride copolymer (SMA resin)
Etc. are included. Among these, from the viewpoint of the balance between the sharpness of color marking and impact resistance, a polymer containing styrene as a constituent monomer, in particular, a rubber-modified styrene resin containing styrene as a constituent monomer and containing a rubber component ( ABS resin, modified ABS resin, etc.) are desirable.

Particularly, as the styrene resin, an acrylonitrile-butadiene-styrene copolymer (ABS resin) or a mixture of an acrylonitrile-butadiene-styrene copolymer and an acrylonitrile-styrene copolymer (a mixture of ABS resin and AS resin) Mixtures) are preferred.
In this case, the constituent ratio of the acrylonitrile monomer unit and the styrene monomer unit in the entire monomer (excluding the rubber component) for forming the styrene resin is, for example, the former / the latter (weight ratio) = 15/85 to 28/72, preferably about 17/83 to 26/74. The composition ratio is often the former / the latter (weight ratio) = about 15/85 to 25/75 (for example, about 18/82 to 24/76). For applications requiring heat resistance, heat-resistant ABS resins such as an α-methylstyrene-modified ABS resin obtained by copolymerizing α-methylstyrene and an imide-modified ABS resin obtained by copolymerizing an imide monomer can be suitably used. The styrene resins can be used alone or in combination of two or more.

In the styrene resin, (1) when the polymer constituting the styrene resin is a homogenous resin, the number average molecular weight of the polymer, and (2) the polymer constituting the styrene resin forms a continuous phase. In the case of a heterogeneous resin composed of a dispersed phase, the number average molecular weight of the matrix component constituting the continuous phase is, for example, 20,000 to 10
0000 (for example, 30,000 to 100,000)
It is preferably about 30,000 to 80,000, especially about 30,000 to 50,000.
For example, when (i) ABS resin or (ii) a mixture of ABS resin and AS resin is used as the styrene resin, (1) when the ABS resin is a homogeneous resin,
BS resin [In the case of the above (ii), ABS resin or A
S resin (preferably, ABS resin and AS resin)] preferably has a number average molecular weight within the above range, and (2)
When the ABS resin is a heterogeneous (two-phase) resin in which a rubber component (polybutadiene) is dispersed in a matrix component (acrylonitrile-styrene copolymer), the matrix component [in the case of (ii) above, The number average molecular weight of the matrix component or the AS resin (preferably, the matrix component and the AS resin)] is desirably within the above range.

If the number average molecular weight is less than 30,000, the impact resistance of the resin composition tends to decrease, and
If it exceeds 00, the melt viscosity of the resin composition becomes too high, and the moldability tends to decrease, and the compatibility with the acrylic resin is insufficient, resulting in poor strength and poor appearance such as flow marks. Cheap.

Further, by reducing the difference between the number average molecular weight of (A) the acrylic resin and the number average molecular weight of (B) the styrene resin, the compatibility between the acrylic resin and the styrene resin is significantly increased, The strength of the resin composition can be improved, and occurrence of appearance defects such as flow marks can be suppressed. The difference ΔMn (= Mn (=) between the number average molecular weight Mn (A) of the acrylic resin and the number average molecular weight Mn (B) of the styrene resin B
| Mn (A) -Mn (B) |) is, for example, 80,000
Or less, preferably 70,000 or less, more preferably 6,8000 or less (especially 6,5000 or less).

The ratio of (A) acrylic resin and (B) styrene resin can be selected from the range of about 1/99 to 80/20 in order to obtain color marking with higher brightness and saturation. (A) / (B) (weight ratio) = 10 /
90-80 / 20, preferably 20 / 80-80 / 20
(For example, 30/70 to 70/30), and particularly 25/75 to 75/25 (for example, 40/60 to 60/30).
40) in many cases. It should be noted that a copolymer of a rubber component, a styrene monomer and a vinyl cyanide monomer, for example, an ABS resin as a component (B) is added to an acrylic monomer as a component (A) (particularly, methacrylic acid). Commercially available transparent ABS resin obtained by copolymerizing (methyl acid) has the same effect as the mixture of the component (A) and the component (B).

Further, in view of the balance between the sharpness of the color marking, the mechanical strength characteristics (particularly, impact resistance) and the moldability, the monomers constituting (A) the acrylic resin and (B) the styrene resin are used. Of the acrylic monomers, in particular, (meth) acrylic acid and (meth) acrylic acid ester account for 20 to 80% by weight in total (for example, 25 to 75% by weight).
% By weight), especially 10 to 90% by weight (for example, 30 to 70% by weight).
% By weight).

[Dye / Pigment] As the dye / pigment, (a) a dye / pigment having a high absorption to laser energy;
A dye or pigment having a color different from that of the component (a) and having low absorption for the laser energy is used. By blending such a two-component dye / pigment, a component having low absorbance to laser energy remains in the portion that has absorbed the laser, and the remaining dye / pigment combination
Enables color marking.

In the present invention, the term "dye / pigment" means a dye or a pigment, and there is a case where both cannot be strictly classified.

(A) Dye / Pigment The (a) dye / pigment is a dye / pigment having a high absorption to laser energy, and usually (a1) an absorbance of 0.8 or more (for example, 0.8 to 2.0, preferably 0.8-1.
6) a black pigment, (a2) an absorbance of 0.8 or more (for example,
Non-black pigments of 0.8 to 2.0, preferably 0.8 to 1.6) are used. These dyes and pigments can be used alone or differently, alone or in combination of two or more.

Here, the absorbance (OD) is the logarithm of the reciprocal of the reflectance R measured by a spectrophotometer or a near-infrared absorbance measuring device, that is, OD = log (1 / R).

As the component (a1), for example, carbon black (for example, acetylene black, lamp black, thermal black, furnace black, channel black, Ketjen black, etc.), graphite,
Examples include black pigments such as titanium black and black iron oxide. Among these, carbon black is particularly desirable from the viewpoints of dispersibility, coloring property and cost. In addition, carbon black is classified into acetylene black, oil black, gas black and the like according to the difference in raw materials, and any carbon black can be used.

The average particle size of the black pigment is, for example, 10 nm to
It can be selected from a wide range of about 3 μm (preferably 10 nm to 1 μm). When the black pigment is carbon black, the average particle size is, for example, 10
To 90 nm, preferably 14 to 90 nm (for example, 16 to 90 nm).
To 80 nm), more preferably about 17 to 50 nm (particularly, 17 to 40 nm), for example, 15 to 20 nm.
It may be about nm. If the particle size of the black pigment is too small, a large amount of energy is required for marking, while if too large, physical properties such as mechanical strength are likely to be reduced.

Although the type of the component (a2) is not limited, it is usually an inorganic pigment. As the component (a2), for example,
White pigments, yellow pigments [eg, cadmium yellow (cadmium yellow), graphite (chrome yellow), zinc chromate, ocher (ocher), yellow iron oxide (Mars yellow), etc.], red pigments [eg, red mouth pigment, amber, Red iron oxide (red petal, rust powder), cadmium red (fire red), lead red (iron trioxide,
Komyotan), blue pigments (for example, navy blue, ultramarine, cobalt blue (tenal blue), etc.), green pigments (for example, chrome green, cobalt green, viridian, etc.) and the like. A blue pigment (for example, a blue fired pigment such as cobalt blue), a chromium green pigment (for example, a green fired pigment such as chrome green), or the like is used. These components may be used alone or in combination of two or more.

The average particle size of the non-black pigment is, for example, 0.01
To 3 μm, preferably about 0.01 to 1 μm.

The component (a) absorbs laser energy and converts it into thermal energy to melt-foam or craze the thermoplastic resin, and at the same time, color marking is possible by abrasion or scattering of the pigment itself. I do. Further, the component (a2) scatters a laser beam (for example, a wavelength of 1064 nm) and remarkably enhances the absorption efficiency of the laser beam by the component (a1) and the conversion efficiency to heat, or the component (a1) and the component (a2). When used in combination, very excellent color marking can be performed. In addition, the irradiation energy intensity of the laser beam can be reduced.

(A) The amount of the dye / pigment used is as follows.
The amount can be selected from the range of 0.005 to 5 parts by weight, preferably 0.05 to 3 parts by weight, more preferably about 0.1 to 1 part by weight with respect to 00 parts by weight.

The amount of the component (a1) used is as follows.
0.005 to 0.5 parts by weight (e.g., 0.005 to 0.3 parts by weight), preferably 0.01 to 0.5 parts by weight with respect to 00 parts by weight.
To 0.3 parts by weight (for example, 0.01 to 0.2 parts by weight).

The amount of component (a2) used is
2 parts by weight or less (for example, 0.01 parts by weight)
To 2 parts by weight), preferably 1 part by weight or less (e.g.
0.05 to 1 part by weight), and more preferably 0.05 to 0.5 part by weight.
It can be selected from the range of about parts by weight (for example, 0.1 to 0.5 parts by weight).

(B) Dye / Pigment The (b) dye / pigment is a dye / pigment having a color different from that of the component (a) and having low absorption for laser energy, and usually having an absorbance of 0.6 or less (for example, Dyes and pigments of from 0 to 0.5, preferably 0 to 0.2), in particular organic dyes and pigments, are used. The difference between the absorbance of the component (a) and the component is preferably 0.5 or more (for example, 0.6 to 1.5), more preferably about 0.8 or more (for example, 0.8 to 1.5). . These dyes / pigments can be used alone or differently, alone or in combination of two or more.

(B) Examples of the dyes and pigments include phthalocyanine dyes, anthraquinone dyes, azo dyes, quinophthalone dyes, perylene dyes, triphenylmethane dyes, xanthene dyes, and nitro dyes. Dyes and pigments,
Nitroso dyes, quinone imine dyes, methine dyes, benzoquinone dyes, naphthalimide dyes,
Perinone dyes and pigments can be exemplified. These dyes and pigments
They may be used alone or in combination of two or more. Of these, phthalocyanine dyes and pigments are usually
Anthraquinone dyes, azo dyes and the like are used.

(B) The amount of the dye / pigment used is the thermoplastic resin 1
0.001 to 5 parts by weight (e.g.,
0.01 to 5 parts by weight), preferably from 0.01 to 3 parts by weight, more preferably from about 0.05 to 1 part by weight.

The ratio (weight ratio) of component (a) to component (b) is (a) / (b) = 10 / 90-90 / 10, preferably 20 / 80-80 / 20, and more preferably. 3
It can be selected from a range of about 0/70 to 70/30.

(D) Dyes and pigments Further, white pigments [for example, calcium carbonate, titanium oxide (titanium white), zinc oxide, zinc sulfide, lithopone, etc.],
A titanium-based yellow pigment or the like may be used. Of these, titanium-based white pigments (for example, white fired pigments such as titanium oxide) and titanium-based yellow pigments (for example, yellow fired pigments such as titanium yellow) are used. The titanium-based white pigment scatters a laser beam and has a function of significantly increasing the efficiency of absorption of the laser beam and conversion efficiency into heat by the (a1) black pigment (for example, carbon black). Shows similar behavior to the components. Further, both can be added for the purpose of toning.

The amount of the white pigment used was 100 thermoplastic resin.
2 parts by weight or less (e.g., 0.01 to 2 parts by weight)
Parts by weight), preferably 1.8 parts by weight or less (for example, 0.1 parts by weight).
05 to 1.5 parts by weight), more preferably 0.05 to 1.5 parts by weight.
It can be selected from a range of about 0.5 parts by weight (for example, 0.1 to 0.3 parts by weight).

The amount of the titanium-based yellow pigment used is 2 parts by weight or less (for example, 0.1 part by weight) per 100 parts by weight of the thermoplastic resin.
01 to 2 parts by weight), preferably 1 part by weight or less (for example,
0.05 to 1 part by weight), more preferably 0.05 to 1 part by weight.
It can be selected from a range of about 0.5 parts by weight (for example, 0.1 to 0.5 parts by weight).

[Aliphatic metal salt] Further, by blending (c) a fatty acid metal salt, the color contrast in laser marking is greatly improved, and clear and sharp marking is possible.

The fatty acid in the fatty acid metal salt may be either saturated or unsaturated, and usually higher fatty acids, especially saturated higher fatty acids, are used. As fatty acids, for example, octylic acid, lauric acid, myristic acid, palmitic acid,
Stearic acid, behenic acid and the like have 8 to 30 (for example, 10 to 30) carbon atoms, preferably 12 to 30 (for example, 1 to 30).
2-28), more preferably 14-24 (e.g., 1
About 6 to 22) saturated aliphatic monocarboxylic acids, oleic acid, linoleic acid, linolenic acid, _C8-30 unsaturated higher monocarboxylic acids such as _elaostearic acid (preferably _C14-30)
Unsaturated monocarboxylic acids, more preferably C _16-22 unsaturated monocarboxylic acids), aliphatic saturated or unsaturated hydroxy acids such as ricinoleic acid and savinic acid, and fats having a cyclic group (such as a cycloalkyl group) such as naphthenic acid Examples thereof include branched aliphatic saturated or unsaturated monocarboxylic acids such as aliphatic saturated or unsaturated monocarboxylic acids and 2-ethylhexenoic acid.
These fatty acids can be used alone or in combination of two or more. Among them, stearic acid, behenic acid and the like have 12 to 28 carbon atoms, preferably 14 to 24 carbon atoms, particularly 16 to 24 carbon atoms.
About 22 saturated aliphatic monocarboxylic acids (eg, stearic acid, behenic acid) are preferred.

Examples of the kind of the metal salt in the fatty acid metal salt include various metal salts, for example, Group Ia of the periodic table (for example,
Sodium, potassium, rubidium, cesium), II
Group a (eg, beryllium, magnesium, calcium, strontium, barium), Group VIII (eg, iron, nickel, cobalt), Group Ib (eg, copper,
Silver, gold), group IIb (eg, zinc, cadmium), I
Examples thereof include metal salts of Group IIb (eg, aluminum, gallium, indium) and Group IVb (eg, germanium, tin, lead). Among them, polyvalent metal salts (for example, II such as magnesium, calcium, barium, etc.)
a, Group Ib such as copper, Group IIb such as zinc, Group IIIb such as aluminum, and Group IVb such as lead).

Preferred fatty acid metal salts include saturated aliphatic monocarboxylic acids having 12 to 28 (particularly 16 to 22) carbon atoms, such as stearic acid, and polyvalent metals (eg, alkaline earth metals such as magnesium, calcium, and barium). Copper, zinc,
Salts with metals such as aluminum and lead).

The amount of the aliphatic metal salt to be used is as follows.
0.001 to 2 parts by weight, preferably 0.01 to 1 part by weight, more preferably 0.05 to 1 part by weight with respect to 00 parts by weight.
It can be selected from a range of about 0.5 parts by weight.

The resin composition of the present invention may contain, if necessary, a compatibilizer, another dye / pigment, a flame retardant, a filler (glass fiber, carbon fiber, metal filler, etc.), a stabilizer (antioxidant, ultraviolet ray). Absorbent), a lubricant, a dispersant, a foaming agent, an antibacterial agent, and the like. For example, by adding a flame retardant or a filler to the resin composition, high functionality (fire retardancy, glass reinforcement, etc.)
Can be achieved.

The resin composition can be prepared by mixing (for example, melt-kneading) the respective components by a conventional mixing method using, for example, an extruder, a kneader, a mixer, a roll and the like.

Various molded articles can be produced by subjecting the resin composition of the present invention to a conventional molding method such as extrusion molding, injection molding and compression molding. Then, by irradiating these molded articles with a laser beam, color marking can be performed on the surface. As a device for irradiating a laser beam, for example, a conventional laser such as a YAG laser (for example, a wavelength of 354 nm, 532 nm, or 1064 nm), a CO ₂ laser, an Ar laser, an excimer laser or the like can be used, but a YAG laser is often used.

Since the resin composition of the present invention contains a specific dye and pigment and an aliphatic metal salt, the color marking property can be greatly improved. In addition, since characters and the like can be easily formed by a laser beam without using a paint or ink, recycling is possible and the cost is low. Therefore, OA equipment such as keyboards for computers and word processors, automobile parts (button parts, etc.), household goods,
It is useful in obtaining a wide range of molded products used by printing characters and designs on the surface, such as building materials.

[0061]

According to the resin composition for color marking of the present invention, extremely clear color marking can be performed by irradiation with a laser beam.

[0062]

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited at all by these examples. In the following example,
Parts and percentages are by weight.

[Laser Marking Conditions and Evaluation Method] Each sample was dried and mixed, and then blended at 200 to 230 ° C. in a twin-screw extruder to prepare pellets.
From the prepared pellets, a plate having a thickness of 3 mm was prepared by injection molding, and the surface was irradiated with a laser beam to check the marking properties. Wavelength 1064 as laser beam
An Nd: YAG laser emitting a laser beam of nm nm was used. As the irradiation conditions, the aperture was fixed at 2 mm, the light source current value (LC), the QS frequency (QS) and the speed (SP) were changed in the following ranges, and a pattern was drawn.
The part marked with the best contrast was evaluated.

Light source current value (LC): 8 to 20 A QS frequency (QS): 1 to 10 kHz Speed (SP): 100 to 1500 mm / sec

[Measurement of Absorbance of Dye / Pigment]
Since a laser beam having a wavelength of 064 nm was used, the near-infrared absorbance was evaluated. Place the pigment powder in the sample holder and use the white ceramic plate as a control.
The reflectance was measured using Ebbe InfraLyzer500, and the absorbance OD was calculated from the value.

[Components used in Examples and Comparative Examples] (A) Acrylic resin • Polymethyl methacrylate (PMMA): Acrypet VH, manufactured by Mitsubishi Rayon Co., Ltd.

(B) Styrene resin ABS resin: ABS resin manufactured by emulsion polymerization method and having a butadiene content of 30% AS resin: AS resin manufactured by bulk polymerization method and having an acrylonitrile content of 23% Transparent ABS resin: acrylonitrile component content 10
%, Styrene content 22%, butadiene rubber content 10%, methyl methacrylate content 58%

(A) Dyes and pigments ・ Carbon black: VULCAN, manufactured by CABOT
P, average particle diameter 20 nm, OD 1.51-Black inorganic fired pigment: 42-3, manufactured by Nippon Fellow Co., Ltd.
03A, OD 1.41-Blue inorganic pigment: Cobalt-based fired pigment (42-250A, manufactured by Nippon Fellow Co., Ltd.), OD 0.80-Green inorganic pigment: 42-633, manufactured by Nippon Fellow Co., Ltd.
A, OD 0.59

(B) Dye / Pigment Green organic pigment: Copper phthalocyanine organic pigment (manufactured by Sumika Color Co., Ltd., SHPA404), OD 0.56 Red organic pigment: anthraquinone organic pigment (manufactured by Arimoto Chemical Co., Ltd.) , PR-8320), OD 0.14. Orange organic pigment: bisazo organic pigment (Arimoto Chemical Co., Ltd.)
AO-501), OD0.12 Blue organic pigment: phthalocyanine-based organic pigment (manufactured by Sumika Color Co., Ltd., SHPA522), OD0.22 Yellow dye: quinophthalone-based organic dye (Mitsubishi Chemical Corporation)
Manufactured by DiaresinYellow DY-H2G)
OD 0.14 Blue organic dye: Anthraquinone organic dye (Diaresin Blue N, manufactured by Mitsubishi Kasei Co., Ltd.), OD
0.26 ・ Green organic dye: Anthraquinone organic dye (Diaresin Green C, manufactured by Mitsubishi Chemical Corporation), OD
0.17 ・ Orange organic dye: Perylene organic dye (Mitsubishi Chemical Corporation)
Diaresin Orange HS), OD0.
13 Red organic dye: anthraquinone-based organic dye (Diaresin Red H, manufactured by Mitsubishi Kasei Corporation), OD0.
13

(D) Dyes and pigments-Titanium oxide: RFC-9, manufactured by Tyoxide Corporation
0, OD 0.15

Example 1 As shown in Table 1, (A) P
50 parts of MMA, (B) 20 parts of ABS resin, (B) 30 parts of AS resin, (a) 0.15 part of carbon black, (a)
0.1 part of titanium oxide, (b) 0.25 part of a green organic pigment,
And (c) for a formulation of 0.1 part zinc stearate, LC = 12.5 A, QS = 4 kHz, SP = 400
When Nd: YAG laser marking at 1064 nm was performed at a rate of mm / sec, very good green marking could be applied to a black background.

Example 2 As shown in Table 1, (A) P
40 parts of MMA, (B) 20 parts of ABS resin, (B) 40 parts of AS resin, (a) 0.15 part of carbon black, (b)
For a blend of 0.25 parts of a green organic pigment and 0.1 part of (c) zinc stearate, LC = 12.5A, QS =
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When YAG laser marking was performed, very good green marking was able to be applied to a black background.

Example 3 As shown in Table 1, (A) P
50 parts of MMA, (B) 25 parts of ABS resin, (B) 25 parts of AS resin, (a) 0.15 part of carbon black, (b)
LC = 12.5A, QS =, for a blend of 0.25 part of red organic pigment and 0.1 part of zinc stearate (c).
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When YAG laser marking was performed, very good red marking could be applied to a black background.

Example 4 As shown in Table 1, transparent AB
100 parts of S resin, (a) 0.15 part of carbon black,
(A) 0.1 part of titanium oxide, (b) red organic pigment 0.2
LC = 12.5A, QS = 4kHz, SP = 4 for a formulation of 5 parts and (c) 0.1 part of zinc stearate.
When the Nd: YAG laser marking of 1064 nm was performed at 00 mm / sec, a very good red marking could be applied to a black background.

(Example 5) As shown in Table 1, (A) P
50 parts of MMA, (B) 20 parts of ABS resin, (B) 30 parts of AS resin, (a) 0.15 part of carbon black, (b)
For a blend of 0.25 parts of an orange organic pigment and 0.1 part of (c) zinc stearate, LC = 12.5A, QS =
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When the YAG laser marking was performed, a very good orange marking could be applied to a black background.

[0076]

[Table 1]

Example 6 As shown in Table 2, (A) P
50 parts of MMA, (B) 20 parts of ABS resin, (B) 30 parts of AS resin, (a) 0.15 part of carbon black, (b)
For a blend of 0.25 parts of a green organic pigment and 0.1 part of (c) zinc stearate, LC = 12.5A, QS =
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When YAG laser marking was performed, very good green marking was able to be applied to a black background.

Example 7 As shown in Table 2, (A) P
40 parts of MMA, (B) 20 parts of ABS resin, (B) 40 parts of AS resin, (a) 0.15 part of carbon black, (b)
For a blend of 0.25 parts of a green organic pigment and 0.1 part of (c) zinc stearate, LC = 12.5A, QS =
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When YAG laser marking was performed, very good green marking was able to be applied to a black background.

(Embodiment 8) As shown in Table 2, (A) P
50 parts of MMA, (B) 25 parts of ABS resin, (B) 25 parts of AS resin, (a) 0.15 part of carbon black, (b)
LC = 12.5A, QS =, for a blend of 0.25 part of red organic pigment and 0.1 part of zinc stearate (c).
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When YAG laser marking was performed, very good red marking could be applied to a black background.

(Embodiment 9) As shown in Table 2, (A) P
40 parts of MMA, (B) 60 parts of ABS resin, (a) 0.15 part of carbon black, (b) 0.25 of red organic pigment
LC = 12.5 A, QS = 4 kHz, SP = 40 for a formulation of 0.1 part of (c) zinc stearate.
When Nd: YAG laser marking of 1064 nm was performed at 0 mm / sec, very good red marking could be applied to a black background.

Example 10 As shown in Table 2, (A)
50 parts of PMMA, (B) 20 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.15 part of carbon black,
For a blend of (b) 0.25 part of an orange organic pigment and (c) 0.1 part of zinc stearate, LC = 12.5A,
QS = 4kHz, SP = 400mm / sec, 1064n
When mNd: YAG laser marking was performed, very good orange marking could be applied to a black background.

(Comparative Example 1) As shown in Table 2, (A) P
50 parts of MMA, (B) 20 parts of ABS resin, (B) 30 parts of AS resin, (a) 0.15 part of carbon black, (a)
For a blend of 0.25 parts of a blue inorganic pigment and 0.1 part of (c) zinc stearate, LC = 12.5A, QS =
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When YAG laser marking was performed, both pigment components were scattered and only white marking was obtained on a black background.

[0083]

[Table 2]

Example 11 As shown in Table 3, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.2 parts of blue inorganic pigment, (b) 0.2 parts of red organic pigment, and (c) 0.1 part of zinc stearate
LC = 12.5 A, QS = 4 kHz for parts of formulation
z, SP = 400 mm / sec, Nd: Y of 1064 nm
When the AG laser marking was performed, very good red marking was able to be applied to the purple background.

(Example 12) As shown in Table 3, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.2 part of black inorganic pigment, (b) 0.2 part of orange organic pigment, and (c) 0.1 part of zinc stearate
LC = 12.5 A, QS = 4 kHz for parts of formulation
z, SP = 400 mm / sec, Nd: Y of 1064 nm
When the AG laser marking was performed, a very good orange marking could be applied to a black background.

(Example 13) As shown in Table 3, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.2 parts of green inorganic pigment, (b) 0.2 parts of red organic pigment, and (c) zinc stearate 0.1
LC = 12.5 A, QS = 4 kHz for parts of formulation
z, SP = 400 mm / sec, Nd: Y of 1064 nm
When the AG laser marking was performed, very good red marking could be applied to mustard colored ground.

[0087]

[Table 3]

Example 14 As shown in Table 4, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.15 part of carbon black,
For a blend of (b) 0.25 part of a red organic dye and (c) 0.1 part of zinc stearate, LC = 12.5A,
QS = 4kHz, SP = 400mm / sec, 1064n
When mNd: YAG laser marking was performed, very good red marking could be applied to a black background.

Example 15 As shown in Table 4, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.15 part of carbon black,
For a blend of (b) 0.25 part of a yellow organic dye and (c) 0.1 part of zinc stearate, LC = 12.5A,
QS = 4kHz, SP = 400mm / sec, 1064n
When mNd: YAG laser marking was performed, a very good yellow marking could be applied to a black background.

Example 16 As shown in Table 4, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.15 part of carbon black,
For a blend of (b) 0.25 part of a blue organic dye and (c) 0.1 part of zinc stearate, LC = 12.5A,
QS = 4kHz, SP = 400mm / sec, 1064n
When mNd: YAG laser marking was performed, very good blue marking could be applied to a black background.

(Example 17) As shown in Table 4, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.15 part of carbon black,
For a blend of (b) 0.25 parts of a green organic dye and (c) 0.1 part of zinc stearate, LC = 12.5A,
QS = 4kHz, SP = 400mm / sec, 1064n
When mNd: YAG laser marking was performed, very good blue marking could be applied to a black background.

Example 18 As shown in Table 4, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
LC = 12.5A, QS = 30 parts of resin, 0.25 part of (a) black inorganic pigment, 0.25 part of (b) orange organic dye, and (c) 0.1 part of zinc stearate.
4 kHz, SP = 400 mm / sec, N of 1064 nm
d: When the YAG laser marking was performed, a very good orange marking could be applied to a black background.

Example 19 As shown in Table 4, (A)
40 parts of PMMA, (B) 30 parts of ABS resin, (B) AS
30 parts of resin, (a) 0.25 part of blue inorganic pigment, (b) 0.2 part of red organic dye, and (c) zinc stearate 0.1 part.
LC = 12.5A, QS = 4k for 1 part of formulation
Hz, SP = 400 mm / sec, Nd at 1064 nm:
When YAG laser marking was performed, very good red marking could be applied to the purple background.

[0094]

[Table 4]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 3/22 C08K 5/098 5/098 C08L 25/00 C08L 25/00 25/12 25/12 33 / 00 33/00 33/10 33/10 B41M 5/26 SF term (reference) 2H111 HA14 HA21 HA32 4F071 AA02 AA12X AA22 AA22X AA31 AA33 AA34X AA77 AB03 AB18 AC09 AE09 AG15 AH19 BA01 BB05 BC03 4J002 BB00 BB00 BB00BB BB12X BC00W BC00X BD03W BD03X BD10W BD10X BD12W BD12X BE02W BE02X BE03W BE03X BE06W BE06X BF02W BF02X BG00W BG00X CB00W CB00X CD00W CD00X CF05W CF05X CF16W CF16X CH00W CH00X CH07W CH07X CH08W CH08X CJ00W CJ00X CK02W CK02X CL01W CL01X CL03W CL03X CL05W CL05X CM04W CM04X DA026 DA036 DE116 DE136 EG018 FD096 FD097 FD208 GT00

Claims (13)

[Claims] 1. A thermoplastic resin and the following (a) to (c):
A resin composition for color marking, comprising a component and capable of performing color marking by irradiation with a laser beam. (A) a dye / pigment having a high absorption for laser energy (b) a dye / pigment having a color different from that of the component (a) and having a low absorption for the laser energy (c) a fatty acid metal salt 2. The color marking device according to claim 1, wherein the component (a) is at least one selected from (a1) a black pigment having an absorbance of 0.8 or more and (a2) a non-black pigment having an absorbance of 0.8 or more. Resin composition. 3. The resin composition for color marking according to claim 2, wherein the component (a1) is at least one selected from carbon black, graphite, titanium black, and black iron oxide. 4. The color marking resin composition according to claim 2, wherein the component (a2) is at least one selected from a cobalt-based blue pigment and a chromium-based green pigment. 5. The resin composition for color marking according to claim 1, wherein the component (b) is a dye or pigment having an absorbance of 0.6 or less. 6. The color marking resin composition according to claim 5, wherein the dye or pigment is an organic dye or pigment. 7. The resin composition for color marking according to claim 1, further comprising (d) at least one selected from a titanium-based white pigment and a titanium-based yellow pigment. 8. The resin composition for color marking according to claim 1, wherein the thermoplastic resin comprises (A) an acrylic resin and (B) a styrene resin. 9. The ratio of (A) an acrylic resin and (B) a styrene resin is (A) / (B) = 20/80 to 80.
The resin composition for color marking according to claim 8, wherein the ratio is / 20 (weight ratio). 10. The (A) acrylic resin is a methyl methacrylate resin having at least a methyl methacrylate unit, and (B) the styrene resin is a rubber component, a styrene monomer, and a vinyl cyanide. 9. The resin composition for color marking according to claim 8, comprising a copolymer with a system monomer. 11. With respect to 100 parts by weight of the thermoplastic resin,
0.005 to 5 parts by weight of component (a), component 0.00
The resin composition for color marking according to claim 1, wherein the proportion is 1 to 5 parts by weight and 0.001 to 2 parts by weight of the component (c). 12. A molded article comprising the resin composition according to claim 1 and capable of performing color laser marking. 13. The molded article according to claim 12, wherein the wavelength is 10
A method of performing chromatic color marking by irradiating a YAG laser having a wavelength of 64, 532 or 354 nm.