JP5290874B2 - Acrylic laser marking resin composition and laser marking method - Google Patents

Description

  The present invention provides an acrylic laser marking resin composition having a high contrast between a dark fabric color and a laser beam irradiated portion, and capable of marking clear, white letters, symbols, figures, etc. In more detail, the laser marking method using, more specifically, the plastic used for in-vehicle parts, electrical / electronic parts, etc., the contrast between the fabric color and the printed part is high, yellow, reddish, clear white characters, symbols, etc. The present invention relates to an acrylic laser marking resin composition excellent in heat resistance, impact resistance, surface hardness, and surface gloss and a laser marking method using the same.

  Today, in almost every field of industry, product labels and marks are essential. For example, as a method for marking characters, symbols and the like on the surface of resin molded products such as electric products and electronic parts, tampo printing using ink, silk printing, and the like are used. However, the marking methods using these inks have the problem that the ink is scattered, the marking takes time and the productivity is poor, and the durability is inferior due to insufficient adhesion of the ink. Therefore, in order to solve these problems, a laser marking method in which letters, symbols, and the like are printed on the surface of a plastic molded article by irradiating a laser beam, and a resin composition for use in the method are disclosed (for example, Patent Document 1). To 3).

  Such a conventional laser marking method is a method of printing on the surface of a plastic molded product. Specifically, a ground color formed by kneading an additive such as carbon black or low-order titanium oxide with a thermoplastic resin. Is a method of irradiating a black plastic molded product with a laser beam to develop white characters, white symbols, white designs, etc. on the surface.

JP-A-8-120133 JP-A-8-127175 JP-A-8-127670

  However, even with such conventional laser marking methods and resin compositions, laser marking that still has high visibility, clear and sufficient contrast has not been obtained, and clearer and sufficient contrast can be obtained. Resin compositions and laser marking methods are required.

  In recent years, with the widespread use of personal computers, printing methods using ink have the problem that the characters and symbols on the keyboard are rubbed and become blurred as they are used. Being started. However, laptop computers may be used in various environments such as in trains, cars, and outdoors, and may be left for a long time. Especially in cars, the temperature inside the car is quite high in summer. Therefore, the heat resistance of the resin material used for the keyboard has been required.

  The present invention is to provide such a resin composition for laser marking that has both heat resistance and clear laser marking properties, and the problem is that it is transparent and vivid coloring is possible. Yes, it can mark on-vehicle components, electrical / electronic parts, etc., with clear white letters and symbols with little yellowness and redness by laser light irradiation, for heat resistance, impact resistance, surface hardness, and surface gloss The object is to provide an excellent acrylic laser marking resin composition.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors include a mixed resin containing a predetermined acrylic resin and a predetermined transparent acrylonitrile-butadiene-styrene resin, and a laser light energy absorber, thereby providing the above-mentioned problem. The present inventors have found that it is possible to achieve the problem and have completed the present invention.

  That is, according to the present invention, the following acrylic laser marking resin composition and laser marking method are provided.

[1] A mixed resin containing 30 to 70% by mass of an acrylic resin (A) and 30 to 70% by mass of a transparent acrylonitrile / butadiene / styrene resin (B) (provided that (A) + (B) = 100% by mass) And 0.0005 to 5 parts by mass of a laser beam energy absorber with respect to 100 parts by mass of the mixed resin, and the content ratio of the acrylic resin (A) is 100% by mass of the mixed resin. 30 to 70% by mass, and the content ratio of the transparent acrylonitrile / butadiene / styrene resin (B) is 30 to 70% by mass with respect to 100% by mass of the mixed resin, and the acrylic resin (A). The deflection temperature under load measured by applying a load of 1.82 MPa in accordance with ISO-75 is 95 ° C. or more, and a notched Charpy impact measured in accordance with ISO-179. Strength is at 1 kJ / ^{m 2} or more, of the transparent acrylonitrile butadiene styrene resin (B), the total light transmittance of the molded article thickness 3mm 85% or more, a load of 1.82MPa in accordance with ISO-75 Rockwell measured with load deflection temperature measured at 70 ° C or higher, notched Charpy impact strength measured according to ISO-179 of 5 kJ / m ² or higher, and ISO-2039.2 An acrylic laser marking resin composition having a hardness (R scale) of 110 or more.

[2] The deflection temperature under load measured by applying a load of 1.82 MPa according to ISO-75 is 86 ° C. or more, and the Charpy impact strength with notch measured according to ISO-179 is 5 kJ. / ^{m 2} or more, and ISO-2039.2 Rockwell hardness (R scale) measured in compliance with acrylic laser marking resin composition according to [1] is 115 or more.

  [3] The acrylic laser marking resin composition according to [1] or [2], further including 0.001 to 10 parts by mass of a colorant with respect to 100 parts by mass of the mixed resin.

  [4] The laser light energy absorbent according to any one of [1] to [3], wherein the laser light energy absorber is at least one selected from the group consisting of carbon black, metal oxide, metal nitride, and metal sulfide. Acrylic laser marking resin composition.

  [5] On the surface of the molded body comprising the acrylic laser marking resin composition according to any one of [1] to [4], the laser medium is neodymium-modified yttrium-aluminum-garnet or yttrium-vanadium tetroxide. A laser marking method for printing by irradiating a solid laser beam.

  The acrylic laser marking resin composition of the present invention is transparent, can be vividly colored, and displays clear white letters, symbols, etc. that are yellowish and less reddish when irradiated with laser light. It can mark parts and the like, and has the effect of being excellent in heat resistance, impact resistance, surface hardness, and surface gloss.

  In addition, according to the laser marking method of the present invention, there is a sense of transparency, vivid coloring is possible, and clear white characters, symbols, etc. that are yellowish and less reddish by laser light irradiation are displayed on the vehicle-mounted member, electric / electronic There is an effect that parts can be marked.

  Hereinafter, embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments, and based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that modifications, improvements, and the like appropriately added to the embodiments described above fall within the scope of the present invention.

I Acrylic Laser Marking Resin Composition The acrylic laser marking resin composition of the present invention comprises an acrylic resin (A) and a transparent acrylonitrile / butadiene / styrene resin (B) (hereinafter also referred to as “ABS resin (B)”). Containing a mixed resin and a laser light energy absorber. Moreover, it is preferable that it further contains a coloring agent.

1 Mixed resin Mixed resin contains acrylic resin (A) 30-70 mass% and transparent ABS resin (B) 30-70 mass% (however, (A) + (B) = 100 mass%). When the content of the acrylic resin (A) is less than 30% by mass and the content of the transparent ABS resin (B) is more than 70% by mass, the heat resistance and the surface hardness are inferior, and the laser coloring property and the color sharpness are inferior. There is. On the other hand, when the content ratio of the acrylic resin (A) is more than 70% by mass and the content ratio of the transparent ABS resin (B) is less than 30% by mass, the impact resistance may be insufficient.

The mixed resin has a deflection temperature under load of 86 ° C. or more measured by applying a load of 1.82 MPa according to ISO-75, and a Charpy impact strength with notch measured according to ISO-179 of 5 kJ / m. It is preferable that the Rockwell hardness (R scale) measured based on ² or more and ISO-2039.2 is 115 or more. By containing such a mixed resin, it has a clear feeling and can be colored vividly, and when it is irradiated with laser light, it becomes clear yellow characters with less redness, symbols, etc. An acrylic laser marking resin composition excellent in heat resistance, impact resistance, surface hardness, and surface gloss can be produced.

  It is preferable that the deflection temperature under load measured by applying a load of 1.82 MPa according to ISO-75 of the mixed resin is 86 ° C. or higher. When the deflection temperature under load is less than 86 ° C, for example, when used as a key top of a notebook computer, the heat resistance is inferior, such as being unable to withstand the high temperatures of the summertime in a car and causing the key top to deform. May cause problems.

Moreover, it is preferable that the Charpy impact strength with a notch measured according to ISO-179 of a mixed resin is 5 kJ / m < ² > or more. If the Charpy impact strength with notch is less than 5 kJ / m ² , for example, when it is used as a key top of a notebook computer, it will fall into the key top due to a drop during molding or storage or a collision with another object. Problems such as cracks may occur. The upper limit of the notched Charpy impact strength is not particularly limited, but is preferably ²⁰ kJ / m ² or less.

  Furthermore, it is preferable that the Rockwell hardness (R scale) of the mixed resin measured in accordance with ISO-2039.2 is 115 or more. When the Rockwell hardness (R scale) is less than 115, for example, when used for a key top of a notebook computer or a game machine, the surface is easily damaged, in other words, the scratch resistance is not sufficient. May occur. The upper limit of Rockwell hardness (R scale) is not particularly limited, but is preferably 125 or less.

(1) Acrylic resin (A)
Acrylic resin (A) has a deflection temperature under load measured by applying a load of 1.82 MPa according to ISO-75 at 95 ° C. or more and a Charpy impact strength with notch measured according to ISO-179 of 1 kJ. / M ² or more is not particularly limited as long as it is an acrylic resin. As such acrylic resin, specifically, trade name “Parapet HR-L” (manufactured by Kuraray), trade name “Acripet VH” (manufactured by Mitsubishi Rayon Co., Ltd.), trade name “Delpet 80N”, trade name “Delpet 980N” (manufactured by Asahi Kasei Chemicals Corporation) and the like.

  The deflection temperature under load of the acrylic resin (A) measured by applying a load of 1.82 MPa according to ISO-75 is 95 ° C. or higher. When the deflection temperature under load is less than 95 ° C., the heat resistance of the mixed resin may be inferior. In addition, although it does not specifically limit about the upper limit of load deflection temperature, It is preferable that it is 120 degrees C or less.

Moreover, the Charpy impact strength with a notch measured according to ISO-179 of an acrylic resin (A) is 1 kJ / m < ² > or more. If the Charpy impact strength with notch is less than 1 kJ / m ² , the impact resistance of the mixed resin may be inferior. In addition, although it does not specifically limit about the upper limit of the Charpy impact strength with a notch, It is preferable that it is 10 kJ / m < ² > or less.

  The content rate of an acrylic resin (A) is 30-70 mass% with respect to 100 mass% of mixed resin, and it is preferable that it is 30-50 mass%. When the content ratio of the acrylic resin (A) is less than 30% by mass, the surface hardness and the heat resistance may be inferior, and the laser coloring property and the color sharpness may be inferior. On the other hand, if it exceeds 70% by mass, the impact resistance may be insufficient.

(2) Transparent acrylonitrile / butadiene / styrene resin (B)
The transparent ABS resin (B) has a total light transmittance of 85% or more of a molded product having a thickness of 3 mm, a deflection temperature under load measured by applying a load of 1.82 MPa according to ISO-75, and an ISO. A transparent ABS resin having a notched Charpy impact strength measured according to -179 of 5 kJ / m ² or more and a Rockwell hardness (R scale) measured according to ISO-2039.2 of 110 or more. There is no particular limitation. Specific examples of such a transparent ABS resin include trade name “Techno ABS H814” (manufactured by Techno Polymer Co., Ltd.), trade name “Novaloy E80” (manufactured by Daicel Polymer Co., Ltd.), and the like. In the present specification, “transparent” means that the total light transmittance of a molded product having a thickness of 3 mm is 85% or more.

  The total light transmittance of the molded product having a thickness of 3 mm of the transparent ABS resin (B) is 85% or more. If the total light transmittance is less than 85%, the coloration lacks sharpness, and the whiteness of the white marking portion is reduced due to laser light irradiation, resulting in insufficient black / white contrast in the marking portion. There may be a problem that the marking property cannot be secured or a problem in the visibility of the marking. The upper limit of the total light transmittance is not particularly limited, but is preferably 90% or less.

  Further, the deflection temperature under load of the transparent ABS resin (B) measured by applying a load of 1.82 MPa according to ISO-75 is 70 ° C. or higher, and preferably 80 ° C. or higher. When the deflection temperature under load is less than 70 ° C., the heat resistance of the mixed resin may be inferior. In addition, although it does not specifically limit about the upper limit of load deflection temperature, It is preferable that it is 100 degrees C or less.

Furthermore, the notched Charpy impact strength of the transparent ABS resin (B) measured according to ISO-179 is 5 kJ / m ² or more. If the Charpy impact strength with notch is less than 5 kJ / m ² , the impact resistance of the mixed resin may be inferior. The upper limit of the notched Charpy impact strength is not particularly limited, but is preferably ²⁰ kJ / m ² or less.

  Moreover, the Rockwell hardness (R scale) measured based on ISO-2039.2 of the transparent ABS resin (B) is 110 or more. If the Rockwell hardness (R scale) is less than 110, the surface hardness of the mixed resin may decrease, the scratch resistance and wear resistance may decrease, and the heat resistance of the mixed resin may deteriorate. The upper limit of Rockwell hardness (R scale) is not particularly limited, but is preferably 120 or less.

  The content rate of transparent ABS resin (B) is 30-70 mass% with respect to 100 mass% of mixed resin, and it is preferable that it is 50-70 mass%. If the content of the transparent ABS resin (B) is less than 30% by mass, the impact resistance may be insufficient. On the other hand, if it exceeds 70% by mass, the heat resistance and surface hardness may be inferior, and the laser colorability and coloring clarity may be inferior.

2 Laser Light Energy Absorber A laser light energy absorber is a compound that absorbs laser light, converts the light into heat energy, and carbonizes the surface of the mixed resin with the generated heat for printing. There is no particular limitation as long as it is a substance that absorbs laser light of 1064 nm which is the fundamental wavelength of solid laser such as YAG laser and YVO ₄ laser and / or 532 nm which is its half wavelength, but carbon black, metal oxide, It is preferably at least one selected from the group consisting of metal nitrides and metal sulfides.

Carbon black is classified into furnace black, channel black, thermal black, etc. depending on its production method, and acetylene black, ketjen black, oil black, gas black, etc. depending on the raw material. Can also be used. Specific examples of the metal oxide include tin oxide, bismuth oxide, iron oxide, antimony oxide, calcium oxide, ITO (indium tin oxide), and ATO (antimony-doped tin oxide). It is not limited to. In addition, an oxide generally expressed as Ti _n O _2n-1 (n = 1, 2, 3), such as titanium monoxide, titanium trioxide, titanium trioxide, or the like, which is called low-order titanium oxide. Mention may also be made of titanium and titanium oxide generally represented by TiO _m (m = 1 to 1.99). Titanium oxide called titanium black is TiO _n (n = 0.1 to 1.9). These low-order titanium oxides have the action of oxidizing the low-order titanium oxides by the energy of laser light and forming white TiO ₂ , resulting in a whiter color.

  Examples of the metal nitride and metal sulfide include titanium nitride and zinc sulfide.

  Content of a laser beam energy absorber is 0.0005-5 mass parts with respect to 100 mass parts of mixed resin, and it is preferable that it is 0.001-1 mass part. If the content is less than 0.0005 parts by mass, the color developability may be inferior because the generation of heat by laser irradiation is small. On the other hand, if it exceeds 5 parts by mass, too much heat is generated by laser irradiation, so that the colored portion becomes burnt and the color developability may be inferior.

3 Colorant Examples of the colorant include inorganic pigments, organic pigments, and dyes. Specific examples of the inorganic pigment include a white pigment, a yellow pigment, a red pigment, and a blue pigment. Examples of white pigments include titanium oxide, barium sulfate, zinc sulfide, and zinc oxide. Examples of yellow pigments include iron oxide and titanium yellow. Further, examples of the red pigment include iron oxide. Examples of blue pigments include cobalt blue and ultramarine blue. Specific examples of the organic pigment include monoazo, condensed azo, disazo, heterocyclic ring, quinacridone, perylene, and phthalocyanine. Furthermore, specific examples of the dye include monoazo, anthraquinone, disazo, heterocycle, perinone, thioindigo and the like.

  When these colorants are used to color the fabric color black and dark colors, and when white color is developed by laser light irradiation, redness due to resin burns may occur due to heat generated by laser light irradiation. . In such a case, at least one colorant selected from the group consisting of blue organic pigments, inorganic pigments, and dyes may be used as a complementary colorant.

  The content of the colorant is preferably 0.001 to 10 parts by mass, more preferably 0.01 to 5 parts by mass, and 0.1 to 3 parts by mass with respect to 100 parts by mass of the mixed resin. It is particularly preferred that If the content of the colorant is less than 0.001 part by mass, the coloring power may not be sufficient. On the other hand, if it exceeds 10 parts by mass, the function of the mixed resin may not be sufficiently exhibited (that is, the advantage obtained by containing the mixed resin cannot be obtained).

4 Other Additives In addition, the acrylic laser marking resin composition may have other additives such as a lubricant, a stabilizer, an antioxidant, an ultraviolet absorber, as long as it does not impair its properties, if necessary. A light stabilizer or the like can be added.

  The acrylic laser marking resin composition of the present invention can be obtained by kneading each component using various extruders, Banbury mixers, kneaders, rolls, feeder ruders, and the like. When kneading each component, they may be kneaded all at once or may be added and kneaded in several times.

II Laser Marking Method The laser marking method of the present invention is a method in which the laser medium is a neodymium-modified yttrium-aluminum on the surface of a molded body comprising the acrylic laser marking resin composition described in “I Acrylic Laser Marking Resin Composition”. A method of printing by irradiating a solid laser beam of garnet (hereinafter also referred to as “YAG”) or yttrium-vanadium tetroxide (hereinafter also referred to as “YVO ₄ ”). In such marking by laser irradiation, the laser beam energy absorber present in the molded body generates heat by the laser beam, and a desired portion of the molded body is colored by this heat. Therefore, there is an advantage that even a portion such as a curved surface can be easily printed, and the printed portion does not peel off.

  The method for preparing the molded body from the acrylic laser marking resin composition is not particularly limited, and is performed by injection molding, sheet extrusion, vacuum molding, profile extrusion, foam molding, ink jet press, press molding, blow molding, or the like. It can be used for in-vehicle members, electrical / electronic components, and the like.

As the laser beam, a solid laser such as a YAG laser or a YVO ₄ laser is used. The laser beam may be single mode or multimode. In addition to a laser beam narrowed to a beam diameter of 20 to 40 μm, a wide laser beam such as a beam diameter of 80 to 100 μm can be used, but a laser beam having a beam diameter of 20 to 40 μm in a single mode has a contrast. This is preferable in terms of obtaining good print quality.

Examples of the laser beam include a gas laser such as a He—Ne laser, an Ar laser, a CO ₂ laser, and an excimer laser, a semiconductor laser, and a dye laser in addition to the solid laser.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method of various physical-property values and the evaluation method of various characteristics are shown below.

[Evaluation of Laser Colorability]: Using a Nd / YAG laser (Rosin Basel, RSM30D), laser colorability was evaluated at a laser irradiation rate of 400 mm / sec. In the evaluation, the quality of the contrast between the portion colored by laser irradiation and the fabric portion was visually evaluated according to the following criteria.
A: White color development visibility is good, and there is almost no yellowing.
○: White color visibility is good and slightly yellowish.
(Triangle | delta): Although white color development visibility is favorable, yellowishness and redness are strong.
×: Inferior in white color visibility.

[Evaluation of contrast (lightness difference ΔL)]: The lightness difference between the surface of the molded product and the colored surface portion by laser light was measured using “Color Analyzer TC-1900MK-II” manufactured by Tokyo Denshoku Co., Ltd. It was evaluated as follows.
A: ΔL ≧ 40
○: ΔL = 30 to 39
Δ: ΔL = 15-29
×: ΔL <15

[Notched Charpy Impact Strength (kJ / m ² )]: Notched Charpy impact strength was measured according to ISO-179.

  [Load deflection temperature (° C.)]: The thermal deformation temperature was measured in accordance with ISO-75 using an edgewise method and a load = 1.82 MPa.

  [Rockwell hardness (R scale)]: Rockwell hardness (R scale) was measured according to ISO-2039.2. For Comparative Example 1, the Rockwell hardness (M scale) was measured according to ISO-2039.2.

  [Total light transmittance]: In accordance with JIS K7105, using Nippon Denshoku Industries Co., Ltd. haze meter (trade name “NDH 2000”) and spectrophotometer (trade name “EYE7000”, manufactured by Macbeth Co.). It was measured.

  [Surface gloss]: 60 ° gloss was measured according to JIS Z8741.

[Evaluation of color clarity]: The color clarity of a colored molded product was evaluated according to the following criteria.
A: Excellent in sharpness.
○: Good sharpness.
Δ: The sharpness is inferior.
X: Coloring is dull.

Example 1
As an acrylic resin (A-1), 50 parts of “Parapet HR-L” manufactured by Kuraray Co., Ltd. and 50 parts of “Techno ABS H814” manufactured by Technopolymer Co., Ltd. as a transparent ABS resin (B-1) were extruded at 240 ° C. Thus, a pellet of mixed resin was obtained. This was pre-dried at 100 ° C. for 2 hours, then injection molded at 240 ° C., and various evaluation tests were performed. The notched Charpy impact strength was 6 kJ / m ² , the deflection temperature under load was 90 ° C., the surface gloss was 89, and the Rockwell hardness was 121 (R scale).

Moreover, mixed resin 100 containing 50 parts of "Parapet HR-L" manufactured by Kuraray Co., Ltd. as the acrylic resin (A-1) and 50 parts of "Techno ABS H814" manufactured by Technopolymer Co., Ltd. as the transparent ABS resin (B-1). Carbon black (Mitsubishi Chemical Corporation, # 2300, average particle size = 15 nm, dibutyl phthalate oil supply = 320 mL / 100 gr) 0.09 parts, titanium oxide (Ishihara Sangyo Co., Ltd., CR-60-2) 1 part, 0.1 parts of stearamide as a dispersant, 0.03 part of anthraquinone dye (Mitsubishi Chemical Corporation, Daita Resin Blue K) as a blue colorant is blended and extruded at 240 ° C. As a result, pellets of an acrylic laser marking resin composition were obtained. This was pre-dried at 100 ° C. for 2 hours, then injection molded at 240 ° C., and various evaluation tests were performed. The evaluation of laser colorability is “◎”, the evaluation of contrast is “◎”, the notched Charpy impact strength is 6 kJ / m ² , the deflection temperature under load is 90 ° C., and the surface gloss is 89. Yes, the Rockwell hardness was 121 (R scale), and the evaluation of color sharpness was “「 ”.

In addition, the deflection temperature under load of acrylic resin (A-1) was 102 degreeC, and the Charpy impact strength with a notch was 1.4 kJ / m < ² >. Moreover, the deflection temperature under load of the transparent ABS resin (B-1) is 85 ° C., the notched Charpy impact strength is 8 kJ / m ² , the Rockwell hardness (R scale) is 114, and the molded product has a thickness of 3 mm. The total light transmittance was 88%.

(Example 2)
Mixed resin and acrylic laser marking resin composition in the same manner as in Example 1 except that “Acrypet VH” manufactured by Mitsubishi Rayon Co., Ltd. was used as the acrylic resin (A-2) instead of the acrylic resin (A-1). I got a thing. Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 6 kJ / m ² , the deflection temperature under load was 89 ° C., the surface gloss was 88, and the Rockwell hardness was 121 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “「 ”, the evaluation of contrast is“ ◎ ”, the notched Charpy impact strength is 6 kJ / m ² , and the deflection temperature under load is It was 89 ° C., the surface gloss was 88, the Rockwell hardness was 121 (R scale), and the evaluation of color sharpness was “◎”.

The deflection temperature under load of the acrylic resin (A-2) was 102 ° C., and the Charpy impact strength with notch was 1.4 kJ / m ² .

(Example 3)
A mixed resin and an acrylic laser marking resin composition were obtained in the same manner as in Example 1 except that a mixed resin containing 30 parts of an acrylic resin (A-1) and 70 parts of a transparent ABS resin (B-1) was used. . Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 8 kJ / m ² , the deflection temperature under load was 89 ° C., the surface gloss was 86, and the Rockwell hardness was 120 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “◎”, the evaluation of contrast is “◎”, the Charpy impact strength with notch is 8 kJ / m ² , and the deflection temperature under load is The surface gloss was 86, the Rockwell hardness was 120 (R scale), and the evaluation of color sharpness was “◎”.

Example 4
A mixed resin and an acrylic laser marking resin composition were obtained in the same manner as in Example 1 except that a mixed resin containing 70 parts of the acrylic resin (A-1) and 30 parts of the transparent ABS resin (B-1) was used. . Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 5 kJ / m ² , the deflection temperature under load was 92 ° C., the surface gloss was 90, and the Rockwell hardness was 121 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “「 ”, the evaluation of contrast is“ ◎ ”, the Charpy impact strength with notch is 5 kJ / m ² , and the deflection temperature under load is It was 92 ° C., the surface gloss was 90, the Rockwell hardness was 121 (R scale), and the evaluation of color sharpness was “◎”.

  As shown in Table 1, the acrylic laser marking resin compositions of Examples 1 to 4 obtained clear and clear coloring, almost no yellowing due to laser light irradiation, heat resistance, impact resistance, It was excellent in surface hardness, surface gloss, laser colorability, and contrast.

(Comparative Example 1)
A mixed resin and an acrylic laser marking resin composition were obtained in the same manner as in Example 1 except that the acrylic resin (A-1) was used alone. Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 1.2 kJ / m ² , the deflection temperature under load was 102 ° C., the surface gloss was 91, and the Rockwell hardness was 102 (M scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “「 ”, the evaluation of contrast is“ ◎ ”, the Charpy impact strength with notch is 1.2 kJ / m ² , and the deflection of the load The temperature was 102 ° C., the surface gloss was 91, the Rockwell hardness was 102 (M scale), and the evaluation of color sharpness was “◎”.

(Comparative Example 2)
A mixed resin and an acrylic laser marking resin composition were obtained in the same manner as in Example 1 except that the transparent ABS resin (B-1) was used alone. Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 9 kJ / m ² , the deflection temperature under load was 85 ° C., the surface gloss was 82, and the Rockwell hardness was 114 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “Δ”, the evaluation of contrast is “◯”, the Charpy impact strength with notch is 9 kJ / m ² , and the deflection temperature under load is It was 85 ° C., the surface gloss was 82, the Rockwell hardness was 114 (R scale), and the evaluation of color sharpness was “Δ”.

(Comparative Example 3)
In the same manner as in Example 1 except that 50 parts of acrylic resin (A-1) and 50 parts of “VRL-40” manufactured by Mitsubishi Rayon Co., Ltd. were used as acrylic resin (A-3). An acrylic laser marking resin composition was obtained. Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 4 kJ / m ² , the deflection temperature under load was 83 ° C., the surface gloss was 89, and the Rockwell hardness was 115 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “「 ”, the evaluation of contrast is“ ◎ ”, the notched Charpy impact strength is 4 kJ / m ² , and the deflection temperature under load is It was 83 ° C., the surface gloss was 89, the Rockwell hardness was 115 (R scale), and the evaluation of color sharpness was “◎”.

The deflection temperature under load of the acrylic resin (A-3) was 94 ° C., and the Charpy impact strength with notch was 7 kJ / m ² .

(Comparative Example 4)
A mixed resin and an acrylic laser marking resin composition were obtained in the same manner as in Example 1 except that a mixed resin containing 20 parts of the acrylic resin (A-1) and 80 parts of the transparent ABS resin (B-1) was used. . Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 9 kJ / m ² , the deflection temperature under load was 82 ° C., the surface gloss was 81, and the Rockwell hardness was 116 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “◯”, the evaluation of contrast is “◯”, the notched Charpy impact strength is 9 kJ / m ² , and the deflection temperature under load is The surface gloss was 81, the Rockwell hardness was 116 (R scale), and the evaluation of color sharpness was “Δ”.

(Comparative Example 5)
A mixed resin and an acrylic laser marking resin composition were obtained in the same manner as in Example 1 except that a mixed resin containing 80 parts of the acrylic resin (A-1) and 20 parts of the transparent ABS resin (B-1) was used. . Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was ² kJ / m ² , the deflection temperature under load was 92 ° C., the surface gloss was 90, and the Rockwell hardness was 121 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “「 ”, the evaluation of contrast is“ ◎ ”, the Charpy impact strength with notch is ² kJ / m ² , and the deflection temperature under load is It was 92 ° C., the surface gloss was 90, the Rockwell hardness was 121 (R scale), and the evaluation of color sharpness was “◎”.

(Comparative Example 6)
The same procedure as in Example 1 was performed except that 50 parts of the trade name “DENKA ABS TE20S” (manufactured by Denki Kagaku Kogyo Co., Ltd.) was used as the transparent ABS resin (B-2) instead of the transparent ABS resin (B-1). A mixed resin and an acrylic laser marking resin composition were obtained. Various evaluation was performed using these. The notched Charpy impact strength of the mixed resin was 8 kJ / m ² , the deflection temperature under load was 82 ° C., the surface gloss was 87, and the Rockwell hardness was 118 (R scale). In addition, the evaluation of laser colorability of the acrylic laser marking resin composition is “◎”, the evaluation of contrast is “◎”, the Charpy impact strength with notch is 8 kJ / m ² , and the deflection temperature under load is It was 82 ° C., the surface gloss was 87, the Rockwell hardness was 118 (R scale), and the evaluation of color sharpness was “◎”.

In addition, the deflection temperature under load of the transparent ABS resin (B-2) is 73 ° C., the notched Charpy impact strength is 10 kJ / m ² , the Rockwell hardness (R scale) is 103, and the molded product has a thickness of 3 mm. The total light transmittance was 86%.

  As shown in Table 2, the acrylic laser marking resin composition of Comparative Example 1 is inferior in impact resistance, and the acrylic laser marking resin composition of Comparative Example 2 is heat resistant, colored sharpness, laser colorability, The surface gloss was inferior. Further, the acrylic laser marking resin composition of Comparative Example 3 was excellent in color sharpness and laser colorability, but was insufficient in heat resistance and impact resistance. Furthermore, the acrylic laser marking resin composition of Comparative Example 4 was inferior in heat resistance, color sharpness, and surface gloss. Moreover, the acrylic laser marking resin composition of Comparative Example 5 was inferior in impact resistance, and the acrylic laser marking resin composition in Comparative Example 6 was inferior in heat resistance.

  The acrylic laser marking resin composition of the present invention forms a molded body (for example, a button of a game machine, a medical part, a keyboard of a personal computer, etc.) on which characters, symbols, figures, etc. are printed by laser beam irradiation. It can be suitably used as the material.

Claims (5)

A mixed resin containing 30 to 70% by mass of an acrylic resin (A) and 30 to 70% by mass of a transparent acrylonitrile / butadiene / styrene resin (B) (provided that (A) + (B) = 100% by mass);
0.0005 to 5 parts by mass of a laser beam energy absorber with respect to 100 parts by mass of the mixed resin,
The content ratio of the acrylic resin (A) is 30 to 70% by mass with respect to 100% by mass of the mixed resin,
The content ratio of the transparent acrylonitrile / butadiene / styrene resin (B) is 30 to 70% by mass with respect to 100% by mass of the mixed resin,
The acrylic resin (A) has a deflection temperature under load measured by applying a load of 1.82 MPa according to ISO-75 of 95 ° C. or more, and a notched Charpy impact strength measured according to ISO-179. 1 kJ / m ² or more,
The transparent acrylonitrile / butadiene / styrene resin (B) has a total deflection of 85% or more of a molded product having a thickness of 3 mm, and a deflection temperature measured by applying a load of 1.82 MPa according to ISO-75. 70 ° C. or higher, Notched Charpy impact strength measured according to ISO-179 is 5 kJ / m ² or higher, and Rockwell hardness (R scale) measured according to ISO-2039.2 is 110 or higher. Acrylic laser marking resin composition. The mixed resin has a deflection temperature under load measured by applying a load of 1.82 MPa according to ISO-75 at 86 ° C. or more, and a Charpy impact strength with notch measured according to ISO-179 is 5 kJ / m ^2. The acrylic laser marking resin composition according to claim 1, wherein the Rockwell hardness (R scale) measured in accordance with the above and ISO-2039.2 is 115 or more.   The acrylic laser marking resin composition according to claim 1 or 2, further comprising 0.001 to 10 parts by mass of a colorant with respect to 100 parts by mass of the mixed resin.   The acrylic laser according to any one of claims 1 to 3, wherein the laser light energy absorber is at least one selected from the group consisting of carbon black, metal oxide, metal nitride, and metal sulfide. Marking resin composition. On the surface of the molded body comprising the acrylic laser marking resin composition according to any one of claims 1 to 4,
A laser marking method for printing by irradiating a solid laser beam whose laser medium is neodymium-modified yttrium-aluminum-garnet or yttrium-vanadium tetroxide.