JP2002265582A - Resin and resin composition for laser marking, and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin or resin composition for laser marking, which can exhibit a vivid white marking by irradiation with laser beams and which is excellent in capability of being recycled, and a molded article made therefrom. SOLUTION: The resin for laser marking comprises an aromatic polycarbonate copolymer containing 0.1-10 mass% of polyorganosiloxane structural units. The resin composition for laser marking is obtained by blending (A) the aromatic polycarbonate copolymer and (B) an aromatic polycarbonate resin, and it contains 0.1-10 mass% of polyorganosiloxane structural units. The molded article is made by molding the resin or the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin and a resin composition for laser marking and a molded product thereof. More specifically, the present invention relates to a resin and a resin composition for laser marking capable of performing clear marking by irradiation with a laser beam, and molded articles thereof.

[0002]

2. Description of the Related Art Conventionally, as a method of marking a thermoplastic resin product, printing using an ink such as an ink jet method, screen printing, and an ink writing method has been mainly performed. However, in recent years, attention has been paid to a marking method using a laser beam that can be performed easily and efficiently. The laser marking method is a method of irradiating a surface of a metal, ceramics, polymer organic material, or the like with a laser beam to mark a mark, a bar code, an image, or the like.

[0003] As this laser marking method, (1)
There is a method of marking using a change in surface state (roughening, concave formation) due to etching of a laser beam irradiation part. However, in this method, there is a disadvantage that the boundary between irradiation and non-irradiation of the laser beam is not clear. Further, as an improved method of this method, a method has been proposed in which the laser beam irradiation section is formed into a multilayer structure made of different kinds of resins, and only the surface resin layer is scraped off.
There is a drawback that the manufacturing process of the molded article and the control of the irradiation conditions of the laser beam are complicated.

[0004] Further, (2) a method of marking by utilizing decolorization, discoloration, and alteration of pigments and dyes in a laser beam irradiation part [for example, JP-A-3-10884, JP-A-5-295274] is proposed. Have been. However, in this case, there are restrictions on the types of pigments and dyes that can be added to the laser beam irradiation part, and since these pigments and dyes are easily decolorized and colored by heat,
There is a drawback that the discoloration area is widened and the outline of characters and the like becomes unclear.

[0005] Further, (3) a method of marking using a change in surface state (convex) due to foaming of the material resin due to laser beam irradiation [Japanese Patent Publication No. 2-47314].
Has been proposed. However, in this case, it is necessary to select the optimum laser beam irradiation conditions for each material resin to be used, and it is rare to use one kind of resin alone as the material resin. When marking the surface of an object, there is a problem that a great deal of labor and time are required for setting the optimum laser beam irradiation conditions.

[0006]

According to the present invention, clear marking can be performed by irradiation of a laser beam,
An object of the present invention is to provide a resin and a resin composition for laser marking which are excellent in recyclability and a molded product thereof.

[0007]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a laser marking made of an aromatic polycarbonate copolymer containing a polyorganosiloxane structural unit in a specific ratio. Resin, or a resin composition for laser marking comprising the aromatic polycarbonate copolymer and the aromatic polycarbonate, found that the above object could be achieved, and based on these findings, completed the present invention. .

That is, the gist of the present invention is as follows. [1] 0.1 to 1 polyorganosiloxane structural unit
Laser marking resin comprising an aromatic polycarbonate copolymer containing 0% by mass. [2] The aromatic polycarbonate copolymer contains 0.1 to 10% by mass of a polyorganosiloxane structural unit,
The resin for laser marking according to the above [1], which is an aromatic polycarbonate copolymer having an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group. [3] The above-mentioned [1] or [2], wherein the polyorganosiloxane structural unit is a polydimethylsiloxane structural unit.
The resin for laser marking described in 1. [4] (A) The content of the polyorganosiloxane structural unit is 0.1%.
0.2 to 99.9% by mass of an aromatic polycarbonate copolymer containing 1 to 50% by mass and (B) 0.1 to 99.8% by mass of an aromatic polycarbonate resin are blended to form a polyorganosiloxane structural unit. A resin composition for laser marking having a content of 0.1 to 10% by mass. [5] Alkylphenoxy in which the aromatic polycarbonate copolymer as the component (A) contains 0.1 to 50% by mass of a polyorganosiloxane structural unit and is substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group. The resin composition for laser marking according to the above [4], which is an aromatic polycarbonate copolymer having a group. [6] The aromatic polycarbonate resin of the component (B) is
The resin composition for laser marking according to the above [4] or [5], which is an aromatic polycarbonate resin having an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group. [7] Further, the above-mentioned [4] to [4], in which polytetrafluoroethylene is added as a component (C) in an amount of 0.01 to 2 parts by mass based on 100 parts by mass in total of both components (A) and (B).
The resin composition for laser marking according to any one of [6]. [8] A molded article obtained by molding the resin for laser marking or the resin composition for laser marking according to any one of [1] to [7].

[9] The molded article according to the above [8], wherein the molded article is an electric / electronic device part, a mechanical part, or an automobile part.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The present invention is a laser marking resin comprising an aromatic polycarbonate copolymer containing 0.1 to 10% by mass of a polyorganosiloxane structural unit. As the aromatic polycarbonate copolymer containing the polyorganosiloxane structural unit, copolymers having various structures are known. For example, JP
0-29695, JP-A-3-292359, JP-A-4-202465, JP-A-8-816
No. 20, JP-A-8-302178, JP-A-1
There are those described in JP-A-0-7897.

[0010] The chemical structure of the aromatic polycarbonate copolymer is represented by the following general formula (1):
It has a polyorganosiloxane structural unit represented by

[0011]

Embedded image

[Wherein, R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms or a phenyl group; Z is a single bond, an alkylene group having 1 to 20 carbon atoms;
0 alkylidene group, C 5-20 cycloalkylene group, C 5-20 cycloalkylidene group, —SO
_{It represents a 2-} , -SO-, -S-, -O- or -CO- bond. A and b are integers from 0 to 4. ]

[0013]

Embedded image

[0014] wherein, R ³ to R ⁶ represents an alkyl group or a phenyl group having 1 to 6 carbon atoms each independently, R ⁷ is
Shows an organic residue containing aliphatic or aromatic. Also, n
Is an integer of 1 to 500. Here, in the above general formulas (1) and (2), R ¹
The alkyl group having 1 to 6 carbon atoms to R ⁶ represents a methyl group, an ethyl group, n- propyl group, i- propyl group,
n-butyl group, i-butyl group, sec-butyl group, te
Examples thereof include an rt-butyl group, an n-pentyl group, and an n-hexyl group, and among these, a methyl group is preferred. Examples of the alkylene group having 1 to 20 carbon atoms represented by Z in the general formula (1) include a methylene group, an ethylene group, a trimethylene group, and a tetramethylene group. As the alkylidene group having 2 to 20 carbon atoms, Examples include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, and a pentylidene group. Examples of the cycloalkylene group having 5 to 20 carbon atoms include a cyclopentylene group and a cyclohexylene group, and examples of the cycloalkylidene group having 5 to 20 carbon atoms include a cyclopentylidene group and a cyclohexylidene group. No. Further, examples of the organic residue represented by R ⁷ in the general formula (2) include an o-allylphenol residue, a p-hydroxystyrene residue, and an eugenol residue.
Is more preferably 5 to 100.

The resin for laser marking comprising an aromatic polycarbonate copolymer in the present invention comprises an aromatic polycarbonate structural unit represented by the above general formula (1) and a polyorganosiloxane represented by the general formula (2) An aromatic polycarbonate copolymer comprising structural units and having a polyorganosiloxane structural unit content of 0.1 to 10% by mass is used as a resin for laser marking. When the content of the polyorganosiloxane structural unit in the aromatic polycarbonate copolymer is in such a range as the resin for laser marking, the content of the polyorganosiloxane structural unit is less than 0.1% by mass. Aromatic polycarbonate copolymers have insufficient marking properties with a laser beam, and aromatic polycarbonate copolymers having a polyorganosiloxane structural unit content of more than 10% by mass reduce heat resistance and flame retardancy. This is because the performance as a molding material becomes insufficient.

The polyorganosiloxane structural unit contained in the aromatic polycarbonate copolymer includes, for example, a polydimethylsiloxane structural unit, a polymethylphenylsiloxane structural unit, a polydiphenylsiloxane structural unit, and the like. However, as the resin for laser marking of the present invention, a resin having a polydimethylsiloxane structural unit is preferably used. further,
A more preferable content ratio of the polyorganosiloxane structural unit is 0.3 to 3% by mass.

The aromatic polycarbonate copolymer used in the resin for laser marking of the present invention contains a polyorganosiloxane structural unit in an amount of 0.1 to 10% by mass and has an alkyl group having 10 to 35 carbon atoms as a terminal group. Aromatic polycarbonate copolymers having an alkylphenoxy group substituted with are preferred. Generally, an aromatic polycarbonate resin having a p-tert-butylphenoxy group as a terminal group of the polymer is used. The aromatic polycarbonate copolymer having such a terminal group has a low flowability of the molten resin at the time of molding, and tends to cause poor molding especially at the time of injection molding. According to the aromatic polycarbonate copolymer having an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group of the polymer, the molten resin has excellent fluidity and good moldability. Therefore, the productivity of the molded article is improved. Examples of the alkyl group having 10 to 35 carbon atoms include a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group,
Hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group, tricosyl group, tetracosyl group, pentacosyl group, hexacosyl group, heptacosyl group, octacosyl group, nonacosyl group, triacontyl group, hentriacontyl group, Dotriacontyl group, tritriacontyl group,
Examples thereof include a tetratriacontyl group and a pentatriacontyl group.

The aromatic polycarbonate copolymer used in the resin for laser marking of the present invention has a viscosity average molecular weight of 10,000 to 40,000, preferably 12,000 to 30,000. . If the viscosity average molecular weight of the aromatic polycarbonate copolymer is less than 10,000, the mechanical properties and heat resistance of the molded product may be insufficient, and the viscosity average molecular weight may be 40,000. If it exceeds 000, there is a possibility that molding failure due to a decrease in melt fluidity may be caused.

Next, a method for producing the aromatic polycarbonate copolymer is described, for example, in that an aromatic polycarbonate oligomer for constituting the aromatic polycarbonate portion of the copolymer and a polyorganosiloxane portion for constituting the polyorganosiloxane portion. And a polyorganosiloxane having a reactive group such as an o-allylphenol group, a p-hydroxystyrene group, or an eugenol residue at the molecular terminal of a dihydric phenol with a solvent such as methylene chloride, chlorobenzene, or chloroform. Add an aqueous alkaline solution, use a tertiary amine such as triethylamine or a quaternary ammonium salt such as trimethylbenzylammonium chloride as a catalyst, and perform an interfacial polycondensation reaction in the presence of a phenol as a terminal stopper. Can be manufactured by That.

In order to produce the aromatic polycarbonate oligomer, for example, a method of reacting a dihydric phenol with a carbonate precursor such as phosgene or a carbonate compound in a solvent such as methylene chloride may be employed. it can. Further, a method of producing by a transesterification reaction between a dihydric phenol and a carbonate precursor such as diphenyl carbonate may be adopted.

The dihydric phenol used here includes:
4,4′-dihydroxydiphenyl; 1,1-bis (4
-Hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3-methyl-
4-hydroxyphenyl) propane, 2,2-bis (3
-Phenyl-4-hydroxyphenyl) propane, 2,
Bis (4-hydroxyphenyl) alkanes such as 2-bis (3,5-dimethyl-4-hydroxyphenyl) propane; bis (4-hydroxyphenyl) cyclo such as 1,1-bis (4-hydroxyphenyl) cyclohexane Alkanes; bis (4-hydroxyphenyl) sulfide; bis (4-hydroxyphenyl) sulfone; bis (4-hydroxyphenyl) sulfoxide; bis (4
-Hydroxyphenyl) ether; and 4,4'-dihydroxybenzophenone. Among these, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is particularly preferred. These dihydric phenols may be used alone or in combination of two or more. Examples of the carbonate compound include diaryl carbonates such as diphenyl carbonate and dialkyl carbonates such as dimethyl carbonate and diethyl carbonate.

The aromatic polycarbonate oligomer may have a molecular chain of a straight-chain structure or may have a branched structure. When producing an aromatic polycarbonate oligomer having a branched structure,
As a branching agent, for example, 1,1,1-tris (4-hydroxyphenyl) ethane, α, α ′, α ″ -tris (4
-Hydroxyphenyl) -1,3,5-triisopropylbenzene, 1- [α-methyl-α- (4′-hydroxyphenyl) ethyl] -4- [α ′, α′-bis (4 ″
[Hydroxylphenyl) ethyl] benzene, phloroglucin, trimellitic acid, polyfunctional aromatic compounds such as isatin bis (o-cresol) can be used.

Examples of the terminal stopper include phenol, p-cresol, p-tert-butylphenol, p-tert-octylphenol, p-cumylphenol, p-nonylphenol, p-tert-
Amylphenol, bromophenol, tribromophenol, pentabromophenol, and the like can be used, and among them, phenols containing no halogen atom are preferable because they have little effect on the environment.

The resin for laser marking of the present invention is an aromatic resin containing a polyorganosiloxane structural unit at a predetermined ratio and having an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group. When a polycarbonate copolymer is produced, examples of the terminal stopper include docosylphenol, tetracosylphenol, hexacosylphenol, octacosylphenol, triacontylphenol, dotriacontylphenol, tetracosylphenol and tetracosylphenol. Triacontyl phenol or the like may be used.

Next, with respect to the resin composition for laser marking in the present invention, the aromatic polycarbonate copolymer containing 0.1 to 50% by mass of the polyorganosiloxane structural unit of the component (A) is 0.2 to 99. 9% by mass
And an aromatic polycarbonate resin of component (B) 0.1 to
99.8% by mass is used, and a resin composition having a polyorganosiloxane structural unit content of 0.1 to 10% by mass is used. In preparing the resin composition for laser marking, when an aromatic polycarbonate copolymer having a high content of polyorganosiloxane structural units is used as the component (A), the blending ratio is reduced and the polyorganosiloxane is used. When using an aromatic polycarbonate copolymer having a low content of the siloxane structural unit, the content of the polyorganosiloxane structural unit in the obtained resin composition is increased to 0.1 to
What is necessary is just to make it fall within the range of 10 mass%.

Further, the component (A) contains 0.1 to 50% by mass of a polyorganosiloxane structural unit and has, as a terminal group, an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms. An aromatic polycarbonate copolymer may be used. Then, a mixture of an aromatic polycarbonate copolymer having such a long-chain alkylphenoxy group as a terminal group and an aromatic polycarbonate copolymer having no long-chain alkylphenoxy group as a terminal group at an arbitrary mixing ratio. May be used as the component (A).

Next, as the aromatic polycarbonate resin of the component (B), an aromatic polycarbonate resin used for a general molding material can be used. That is, an aromatic polycarbonate resin having an aromatic polycarbonate structural unit represented by the general formula (1) can be used. In addition, at the molecular chain terminal, the carbon number 10
An aromatic polycarbonate resin having an alkylphenoxy group substituted with an alkyl group of 35 may be used as the component (B). Further, a mixture of an aromatic polycarbonate resin having such a long-chain alkylphenoxy group as a terminal group and an aromatic polycarbonate resin having no long-chain alkylphenoxy group and having no terminal group is mixed at an arbitrary mixing ratio. B) may be used as a component. The aromatic polycarbonate resin of component (B) having a viscosity average molecular weight of 10,000 to 40,000, preferably 12,000 to 30,000 can be suitably used.

Next, as the resin composition for laser marking of the present invention, 0.01 to 2 parts by mass of polytetrafluoroethylene is added to the total of 100 parts by mass of the above components (A) and (B). What was compounded as (C) component can be used. When the mixing ratio of the component (C) is 0.
When the amount is less than 01 parts by mass, the effect of preventing the obtained resin composition from dropping by melting becomes insufficient. Even when the compounding ratio of the component (C) is less than 2 parts by mass, a sufficient effect of preventing melting and dripping can be obtained, and when the amount exceeds 2 parts by mass, the impact resistance of the obtained resin composition is reduced. It starts to decrease.
A more preferable mixing ratio of the component (C) is 0.1 to 1
Parts by weight.

The polytetrafluoroethylene of the component (C) used herein has an average molecular weight of 50
10,000 or more, preferably 500,000 to 10,000
00,000, more preferably 1,000,000 to 1
0,000,000. Furthermore, this (C)
As a component, polytetrafluoroethylene having a fibril-forming ability is preferred because it has an excellent effect of preventing dripping of the melt and can impart high flame retardancy. Polytetrafluoroethylene having such a fibril-forming ability is, for example, tetrafluoroethylene in an aqueous solvent,
Those obtained by polymerization at a pressure of 7 to 700 kPa and a temperature of 0 to 200 ° C, preferably 20 to 100 ° C in the presence of sodium, potassium or ammonium peroxydisulfide are suitably used. Commercial products include Teflon 6-J manufactured by DuPont Fluorochemicals, Mitsui and Polyflon D-1, Polyflon F-103, Polyflon MPA and Polyflon FA-100 manufactured by Daikin Industries, and Algoflon manufactured by Montefluos. F5
Etc. can be used.

The resin or resin composition for laser marking of the present invention may further contain, if necessary, an antioxidant, a plasticizer, a stabilizer, an antistatic agent, a slip agent, an antiblocking agent, an antifogging agent, etc. Can be added. As these additives, generally used additives for aromatic polycarbonate resins may be used in a usual addition ratio.

When producing the resin composition for laser marking, equipment used for mixing or melt-kneading the aromatic polycarbonate resin, for example, a Banbury mixer, a roll, a single-screw extruder or a multi-screw extruder. A method of mixing or melt-kneading the components with a machine or the like can be adopted. When molding various molded articles using the resin or resin composition for laser marking, molding may be performed in the same manner as a known aromatic polycarbonate resin injection molding method, extrusion molding method, blow molding method, or the like. it can.

The laser marking device used for marking the molded article obtained as described above includes:
A marking device using a laser beam such as an excimer laser, a nitrogen laser, a Nd: YAG laser, a crystal laser, and a carbon dioxide laser can be used. Since the resin or resin composition for laser marking of the present invention does not use a coloring material such as carbon black, a clear white marking can be applied to a molded article made of a transparent material or a translucent material. Accordingly, the molded article is suitably used particularly for various electric and electronic equipment parts, mechanical parts, automobile parts, such as housings and optical disks of office automation equipment made of transparent or translucent materials.

The molded article obtained by molding the resin or resin composition for laser marking of the present invention is made of a transparent or translucent material that does not use a coloring material. Low contamination of impurities. Therefore, the physical properties and appearance of the recycled product are good, and the recycled product is excellent in recyclability. In addition, the transparent or translucent material may be colored by using a desired coloring material other than white.

[0034]

[Example 1]

(1) Production of Polycarbonate Oligomer 400 liters of an aqueous solution of sodium hydroxide having a concentration of 5% by mass was mixed with raw material 2,2-bis (4-hydroxyphenyl).
60 kg of propane were dissolved.

Next, a tube type reactor having an inner diameter of 10 mm, a pipe length of 10 m, and a double pipe structure, whose temperature can be controlled by passing water through a jacket portion thereof, is used. Liter / hour, the solvent methylene chloride was fed through the orifice plate at a flow rate of 69 liter / hour. Subsequently, phosgene was blown into this reactor at a flow rate of 10.7 kg / hour in parallel with the flow of the raw material solution, and the temperature of the reactor was maintained at 25 ° C., and the reaction was continuously performed for 3 hours. During the reaction period, the pH of the effluent was adjusted to be 10 to 11.

After completion of the reaction, the obtained reaction solution is allowed to stand,
The aqueous phase was separated and removed to obtain 220 l of a methylene chloride phase. The degree of polymerization of the polycarbonate oligomer dissolved in the methylene chloride phase was 2 to 4, and the concentration of the chloroformate group was 0.7 normal. The concentration of the polycarbonate oligomer in the methylene chloride phase was 317 g / liter.

(2) Production of reactive polydimethylsiloxane Raw material octamethylcyclotetrasiloxane 1,483
g, 1,1,3,3-tetramethyldisiloxane 96
g was mixed with 35 g of sulfuric acid having a concentration of 86% by mass and stirred at room temperature for 17 hours. Thereafter, the oil phase was separated, and 25 g of sodium hydrogen carbonate was added thereto, followed by stirring for 1 hour. Then, after removing sodium hydrogencarbonate by filtration, distillation was performed under reduced pressure at 150 ° C. and 400 Pa to remove low-boiling compounds to obtain an oil.

Next, 60 g of 2-allylphenol and 0.04 g of platinum chloride alcoholate complex were added to 294 g of this oil.
014 g of the mixture was added, and the mixture was stirred and reacted for 3 hours while maintaining the temperature range of 90 to 115 ° C. After completion of the reaction, the obtained product was extracted with methylene chloride, and further washed three times with 80% by mass of aqueous methanol to remove excess 2-allylphenol. This product is
Further, it is dried over anhydrous sodium sulfate, and dried under reduced pressure.
At 5 ° C. the solvent was distilled off. As a result of ¹ H-NMR measurement, the reactive polydimethylsiloxane thus obtained had a dimethylsilanooxy structural unit repeat number of 30.

(3) Production of Aromatic Polycarbonate Copolymer 10 l of a methylene chloride solution of the polycarbonate oligomer obtained in the above (1) and 182 g of the reactive polydimethylsiloxane obtained in the above (2) were mixed with methylene chloride 2 The solution dissolved in liter was mixed. To this mixed solution, a solution prepared by dissolving 26 g of sodium hydroxide in 1 liter of water, 8 liters of methylene chloride and 96 g of pt-butylphenol were added.
The reaction was carried out for 2 hours while stirring at pm.

After completion of the reaction, methylene chloride 5 was added to the reaction product.
One liter was added to dissolve, and this was washed with 5 liters of water. Then, this was washed with 5 liters of an aqueous solution of sodium hydroxide having a concentration of 0.03 N, washed with 5 liters of an aqueous solution of hydrochloric acid having a concentration of 0.2 N, and further washed twice with 5 liters of water. Then, methylene chloride was distilled off from the methylene chloride solution of the reaction product under reduced pressure to obtain a flake-like aromatic polycarbonate copolymer. The copolymer flakes were further vacuum dried at 120 ° C. for 24 hours.

The aromatic polycarbonate copolymer thus obtained has a viscosity average molecular weight of 17,000.
And the content of the polydimethylsiloxane structural unit was 4.0% by mass. The viscosity average molecular weight is
Using an Ubbelohde viscometer, the viscosity of the methylene chloride solution of the copolymer at 20 ° C. was measured, and the intrinsic viscosity [η] was measured.
Was determined and then converted to a viscosity average molecular weight. Also,
The content ratio of the polydimethylsiloxane structural unit is ¹ H-
From the measurement results by NMR, it was found that the 2,2-
The absorption peak at 1.7 ppm derived from the isopropyl group of the bis (4-hydroxyphenyl) propane residue and the absorption peak at 0.2 ppm derived from the methyl group in the dimethylsiloxane structural unit.
It calculated based on the intensity ratio with the absorption peak of ppm.

(4) Laser Marking on Molded Article and Its Evaluation 0.3% by mass of an antioxidant [Chiba] was added to the aromatic polycarbonate copolymer obtained in the above (3) per 100 parts by mass of the copolymer. After adding Specialty Chemicals: Irganox 1076 (0.2 parts by mass) and Irgafoss 168 (0.1 parts by mass)], the mixture was supplied to an extruder [Toshiba Machine Co., Ltd .: TEM-35]. ~ 2
The mixture was melt-kneaded at 80 ° C. and pelletized. After drying the pellets at 120 ° C. for 4 hours, the pellets are supplied to an injection molding machine [100-EN manufactured by Toshiba Machine Co., Ltd.
Under a condition of 280 ° C. and a mold temperature of 80 ° C., the test piece was formed into a square plate-like test piece having a thickness of 2 mm and a side length of 15 cm. This test piece is colorless and transparent, and conforms to JIS K71.
The haze measured according to No. 05 was 2%.

Next, the test piece was marked with "Idemitsu Petrochemical 2001" using a carbon dioxide laser marking apparatus (manufactured by TDK: CLM-03).
In this case, the operating conditions of the carbon dioxide laser marking apparatus are as follows: laser beam wavelength: 10.6 μm, scan speed: 200 mm / sec, output: 1 to 8 W (step;
0.2 W). As a result, a white marking was obtained.

The markings were evaluated by (a) the minimum laser output [w] capable of performing identifiable marking when a fluorescent lamp was placed on the base, and (b) gray paper on the base. The minimum laser power [w] at which identifiable marking was possible was measured to evaluate the visibility of the marking. Further, the conspicuousness of the marking is visually judged by three judges, and from the average value, ◎ = contrast between the base color and the marking character color is excellent; ○ = contrast between the base color and the marking character color Good: Δ: The contrast between the base color and the marking character color was slightly good; × = The contrast between the base color and the marking character color was poor, and evaluated on a 4-point scale.

(5) Evaluation of Physical Properties of Aromatic Polycarbonate Copolymer In addition to laser marking properties, the aromatic polycarbonate copolymer obtained in (3) above was evaluated for fluidity and flame retardancy of the copolymer. evaluated. Regarding the fluidity of this copolymer, a flow value under the conditions of a temperature of 280 ° C. and a load of 1568 N was measured in accordance with JIS K 7201. Regarding the flame retardancy, the thickness was 1.5 mm according to the underwriter laboratory subject 94.
A vertical combustion test was performed on the test pieces of Example 1. Table 1 shows the results of the various evaluations described above.

Example 2 (1) Production of Aromatic Polycarbonate Copolymer 10 L of a methylene chloride solution of a polycarbonate oligomer obtained in the same manner as (1) of Example 1 and (2) of Example 1 A solution obtained by dissolving 182 g of the reactive polydimethylsiloxane obtained in 2 above in 2 liters of methylene chloride was mixed. To this mixture was added a solution prepared by dissolving 26 g of sodium hydroxide in 1 liter of water, 8 liters of methylene chloride, and 168 g of p-dodecylphenol (including a branched dodecyl group) as a terminal stopper, The reaction was carried out at room temperature for 2 hours while stirring at 500 rpm. The reaction product was purified in the same manner as in Example 1, (3) to obtain an aromatic polycarbonate copolymer having a p-dodecylphenoxy group at a molecular chain terminal. The viscosity average molecular weight of this copolymer was 17,000, and the content of polydimethylsiloxane structural units was 4.0% by mass.

(2) Laser marking on molded article and its evaluation Except for using the aromatic polycarbonate copolymer obtained in (1) above, a test piece was prepared in the same manner as in (4) of Example 1. The test piece was molded, laser-marked, and evaluated. (3) Evaluation of physical properties of aromatic polycarbonate copolymer The aromatic polycarbonate copolymer obtained in the above (1) was evaluated for fluidity and flame retardancy of the copolymer in addition to the laser marking property. These results are
It is shown in the table.

Example 3 (1) Production of Aromatic Polycarbonate Resin Composition As the component (A) as the raw material, 30 parts by mass of the aromatic polycarbonate copolymer obtained in (3) of Example 1 B)
As a component, the viscosity average molecular weight is 17,000 and the melt flow rate (temperature: 300 ° C .; load: 11.77)
(N) 70 parts by mass of an aromatic polycarbonate resin (manufactured by Idemitsu Petrochemical Co., Ltd .: Toughlon A1900) having a weight ratio of 19 g / 10 minutes, and 0.3 parts by mass of polytetrafluoroethylene (manufactured by Asahi Glass Company: CD076) as the component (C). Was used. Then, each of these components and the same antioxidant as that used in (3) of Example 1 were mixed and supplied to a vented twin-screw extruder [TEM-35 manufactured by Toshiba Machine Co., Ltd.]
The mixture was melt-kneaded at 280 ° C., extruded as strands of the aromatic polycarbonate resin composition, cooled, and cut to obtain pellets.

(2) Laser marking on molded article and its evaluation Except for using the aromatic polycarbonate resin composition obtained in the above (1), a test piece was prepared in the same manner as in (1) of Example 1. Molding, laser marking the test piece,
I did that evaluation. (3) Evaluation of Physical Properties of Aromatic Polycarbonate Resin Composition The aromatic polycarbonate resin composition obtained in the above (1) was evaluated for fluidity and flame retardancy of this resin composition in addition to laser marking characteristics. The results are shown in Table 1.

Example 4 (1) Production of Aromatic Polycarbonate Resin 10 L of a methylene chloride solution of a polycarbonate oligomer obtained in the same manner as in (1) of Example 1 was placed in a reactor having an internal volume of 50 L with a stirrer. Then, 162 g of p-dodecylphenol (including a branched dodecyl group) was added and dissolved as a terminal stopper.
Next, 53 g of sodium hydroxide was added to this reactor with 1 part of water.
After adding 5.8 ml of the catalyst dissolved in liter and triethylamine as a catalyst, the mixture was reacted for 1 hour with stirring at 300 rpm.

Then, a solution in which 412 g of sodium hydroxide was dissolved in 5.5 liters of water and 720 g of 2,2-bis (4-hydroxyphenyl) propane were dissolved in a reactor containing the reaction product. , And 8 liters of methylene chloride as a solvent were added, and the mixture was reacted for 1 hour under stirring at 500 rpm. After completion of the reaction, 7 liters of methylene chloride and 5 liters of water were added to the reactor, and 50
The mixture was stirred at 0 rpm for 10 minutes, allowed to stand after the stirring was stopped, and the organic phase and the aqueous phase were separated.

Next, this organic phase was washed with 5 liters of an aqueous solution of sodium hydroxide having a concentration of 0.03 N, and then with 5 liters of an aqueous solution of hydrochloric acid having a concentration of 0.2 N. Further, the resultant was washed twice with 5 l of water, and methylene chloride was distilled off under reduced pressure to obtain a flake-like aromatic polycarbonate resin. The thus obtained aromatic polycarbonate resin having a p-dodecylphenoxy group at a molecular chain terminal had a viscosity average molecular weight of 17,500.

(2) Production of aromatic polycarbonate resin composition Except for using the aromatic polycarbonate resin obtained in the above (1) as the component (B), An aromatic polycarbonate resin composition was prepared. (3) Laser marking on molded article and its evaluation Except for using the aromatic polycarbonate resin composition obtained in (2) above, a test piece was molded in the same manner as (2) of Example 3, and the The test piece was laser-marked and evaluated. (4) Evaluation of Physical Properties of Aromatic Polycarbonate Resin Composition The aromatic polycarbonate resin composition obtained in the above (2) was evaluated for fluidity and flame retardancy of the resin composition in addition to laser marking characteristics. The results are shown in Table 1.

Example 5 (1) Production of Aromatic Polycarbonate Resin Composition As the component (A), the aromatic polycarbonate copolymer obtained in (1) of Example 2 was used, and as the component (B) ,
Using the aromatic polycarbonate resin obtained in (1) of Example 4, these were melt-kneaded to produce an aromatic polycarbonate resin composition.

(2) Laser marking on molded article and evaluation thereof A test piece was molded in the same manner as in (2) of Example 3 except that the aromatic polycarbonate resin composition obtained in the above (1) was used. Then, the test piece was laser-marked and evaluated. (3) Evaluation of Physical Properties of Aromatic Polycarbonate Resin Composition The aromatic polycarbonate resin composition obtained in the above (1) was evaluated for fluidity and flame retardancy of this resin composition in addition to laser marking characteristics. The results are shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated except that the aromatic polycarbonate resin used as the component (B) in Example 3 was used as the aromatic polycarbonate resin. Table 1 shows the results. Comparative Example 2 The procedure of Example 1 was repeated except that the aromatic polycarbonate resin produced in (1) of Example 4 was used as the aromatic polycarbonate resin. Table 1 shows the results.

Comparative Example 3 An aromatic polycarbonate resin composition was produced using the same aromatic polycarbonate resin as the component (B) in Example 3 and the same component (C) as in Example 3, except that It was the same as Example 3. Table 1 shows the results. [Comparative Example 4] An aromatic polycarbonate resin composition using the same aromatic polycarbonate resin as the component (B) of Example 3 and dimethyl silicone [manufactured by Toray Dow Silicone Co., Ltd .; SH200] instead of the component (C). Was manufactured in the same manner as in Example 3 except that was manufactured. Table 1 shows the results.

[0058]

[Table 1]

[0059]

[Table 2]

[0060]

According to the present invention, a molded article formed using the resin for laser marking or the resin composition for laser marking of the present invention can perform clear marking by irradiation with a laser beam. In addition, since no coloring material is used, it is possible to mark a transparent molded product, and it is excellent in recyclability.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme coat ゛ (Reference) C08L 27:18) B41M 5/26 SF term (Reference) 2H111 HA14 HA23 HA32 4F071 AA27 AA50 AA67 AA75 AF53 AH07 AH12 AH17 AH19 BC07 BC09 4J002 BD153 CG01X CG02W CG02X CP17W GM00 GN00 GQ00 GS02 4J029 AA09 AB02 AC03 AE01 AE05 AE18 BB09A BB09B BB12A BB12B BD09A BD09B BE05A BE05B BF14A BF14B BH02 DB07 DB11 DB13 FA07 HA01 JE222

Claims (9)

[Claims] 1. The method according to claim 1, wherein the polyorganosiloxane structural unit is contained in an amount of 0.
A resin for laser marking comprising an aromatic polycarbonate copolymer containing 1 to 10% by mass. 2. The aromatic polycarbonate copolymer contains 0.1 to 10% by mass of a polyorganosiloxane structural unit and has an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group. The resin for laser marking according to claim 1, which is an aromatic polycarbonate copolymer. 3. The polyorganosiloxane structural unit is a polydimethylsiloxane structural unit.
The resin for laser marking described in 1. 4. An aromatic polycarbonate copolymer containing 0.1 to 50% by mass of (A) a polyorganosiloxane structural unit and 0.2 to 99.9% by mass of an aromatic polycarbonate resin (B). -99.9% by mass, and the content ratio of the polyorganosiloxane structural unit is 0.1-1.
A resin composition for laser marking comprising 0% by mass. 5. The aromatic polycarbonate copolymer of the component (A) has a polyorganosiloxane structural unit of 0.1 to 0.1.
50% by mass and having 10 to 35 carbon atoms as a terminal group
The resin composition for laser marking according to claim 4, which is an aromatic polycarbonate copolymer having an alkylphenoxy group substituted with an alkyl group. 6. The aromatic polycarbonate resin according to claim 4, wherein the aromatic polycarbonate resin as the component (B) is an aromatic polycarbonate resin having an alkylphenoxy group substituted with an alkyl group having 10 to 35 carbon atoms as a terminal group. Resin composition for laser marking. 7. The composition according to claim 4, further comprising 0.01 to 2 parts by mass of polytetrafluoroethylene as component (C) based on 100 parts by mass of the total of both components (A) and (B).
7. The resin composition for laser marking according to any one of items 1 to 6. 8. A molded product obtained by molding the resin for laser marking or the resin composition for laser marking according to claim 1. 9. The molded article according to claim 8, wherein the molded article is an electric / electronic device part, a mechanical part, or an automobile part.