JPH0367112B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to transparent ABS resin plating products obtained by partially wet plating. Resin-plated products obtained by partially plating transparent ABS resin moldings have light transmittance in the unplated areas (non-plated areas), so the intensity of transmitted light and/or the color of transmitted light varies. For example, by symbolizing the shape of the non-plated part, it is possible to display the status of the function identified by the symbol. To give a concrete example, it is applied to switches and push buttons of light electrical parts, and by converting the shape of the non-metallic part into letters, the ON-OFF state of the switch or push button indicated by the letters can be determined. can be displayed. In this way, resin-plated products obtained by partially plating transparent ABS resin moldings have very few practical examples, although they are industrially useful. This is due to the difficulty in processing a wet plating layer. Resin-plated products have a large linear expansion coefficient difference between the metal phase and the resin phase, so the plating layer tends to peel off from the resin surface as the environmental temperature changes, and this is especially noticeable with transparent ABS resin. transparent
There are two main methods for producing ABS resin: one method is to match the refractive index of the rubber dispersed phase and the resin continuous phase, and the other method is based on the weight average particle diameter of the rubber dispersed phase (general formula Σnd ⁴ /Σnd ³ (directly calculated from the total number of particles, expressed as n: number of particles, d: particle diameter)) is a method of controlling the particle size to about 150 mμ or less, but according to the studies of the present inventors, the above-mentioned Regardless of which method the transparent ABS resin is produced, its plating adhesion is extremely poor compared to ordinary opaque ABS resin. As a result of intensive studies in view of the above findings, the inventors of the present application found that the amount of copolymerization of the diene rubber is 5 to 30% by weight, and the particles of the diene rubber are large with a weight average particle diameter of 150 mμ. It is a mixture of small particles and small particles, and the proportion is 80 to 99% by weight of small particles with a weight average particle diameter of 150 mμ or less.
and large particles with a weight average particle diameter of over 150 mμ
To 100 parts by weight of transparent ABS resin (20% by weight), aliphatic alcohol with 8 or more carbon atoms, polyhydric alcohol, polyvinyl alcohol, aromatic alcohol,
Phenol, cresol, catechol and 2,2
-Resin-plated products made by partially wet-plating a molded product of an ABS resin composition made by adding 0.1 to 10 parts by weight of a compound selected from bis(4'-hydroxyphenylpropane) The inventors have found that a resin-plated product with excellent plating adhesion can be obtained, and that the non-plated portions exhibit sufficient light transmittance, leading to the completion of the present invention.The resin-plated product of the present invention will be described in detail below. The ABS resin used in the present invention is a graft polymer obtained by adding a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer to a diene diameter rubber latex having a specified particle size and carrying out emulsion polymerization. It can be obtained by mixing the polymer A and the graft polymer B, or a copolymer of a monomer mixture containing a vinyl cyanide monomer and an aromatic vinyl monomer (AS resin for dilution), The diene rubbers mentioned here include poly(butadiene), poly(isoprene), poly(chloroprene), poly(butadiene-styrene), poly(butadiene-methyl methacrylate), poly(butadiene-acrylonitrile), etc. Vinyl monomer is
Acrylonitrile, methacrylonitrile, etc., and aromatic vinyl monomers include styrene, α-methylstyrene, t-butylstyrene, vinyltoluene, etc. In the presence of 100 parts by weight (as solid content) of a small diene diameter rubber latex having a weight average particle diameter of 150 mμ or less, the graft polymer A in the present invention is
It is obtained by emulsion polymerization of 60 parts by weight or more of the monomer mixture, but the weight average particle size of the rubber latex is
If it exceeds 150 mμ, the transparency of the ABS resin obtained by mixing graft polymer B will decrease, which is undesirable, and if the monomer mixture used for graft polymerization is less than 60 parts by weight, the obtained transparent ABS
Silver streaks occur on the surface of the resin molding, which is undesirable. Graft polymer B in the present invention is obtained by emulsion polymerization of the monomer mixture in the presence of a large-particle diene rubber latex with a weight average particle size of over 150 mμ, but the weight average particle size of the rubber latex is 150 mμ or less. If this is the case, the plating adhesion of the transparent ABS resin obtained by mixing the graft polymer A will be insufficient, which is not preferable. There are no particular restrictions on the method for producing graft polymer A and graft polymer B in the present invention,
Known techniques of emulsion graft polymerization can be applied. In the present invention, graft polymer A and graft polymer B are then mixed. However, there are no particular restrictions on the mixing method, and mixing can be accomplished in a latex state, powder state, pellet state, or molten state using appropriate known techniques. be able to. In the ABS resin used in the present invention, the total amount of both diene rubbers copolymerized in graft polymer A and graft polymer B is 5 to 30% by weight based on the total amount of both graft polymers, If the total amount of both diene rubbers is less than 5% by weight, plating adhesion will be poor, and if it exceeds 30% by weight, transparency will be poor, which is not preferred. Furthermore, the breakdown of the 5-30% by weight of the copolymerized diene rubber in both graft polymers is 80-99% by weight of the small-particle-diameter diene rubber copolymerized in the graft polymer A.
and large particle size 1 to copolymerized in graft polymer B.
20% by weight, but if the small particle diameter diene rubber is less than 80% by weight, or if the large particle diameter diene rubber exceeds 20% by weight.
The transparency of the ABS resin is poor, and if the small particle size diene rubber exceeds 99% by weight, or if the large particle size diene rubber accounts for less than 1% by weight, plating adhesion will be poor, which is undesirable. The transparent ABS resin used in the present invention is a copolymer of a monomer mixture containing vinyl cyanide monomer and aromatic vinyl monomer (AS resin for dilution), if necessary.
can be added. The vinyl cyanide monomers mentioned here include acrylonitrile, methacrylonitrile, etc., and the aromatic vinyl monomers include styrene, α-methylstyrene, t-butylstyrene, vinyltoluene, etc. There are no particular restrictions on the method for producing the AS resin for dilution, and known techniques such as emulsion polymerization, suspension polymerization, and bulk polymerization can be applied. To the transparent ABS resin used in the present invention, it is necessary to add 0.1 to 10 parts by weight, preferably 0.2 to 5 parts by weight, of a specified alcohol or phenol per 100 parts by weight of the resin. The alcohols mentioned here include aliphatic alcohols having 8 or more carbon atoms, polyhydric alcohols, polyalkylene glycols, polyvinyl alcohols, aromatic alcohols, and the like.
Examples of alcohol that can be used include:
Aliphatic alcohols with 8 or more carbon atoms include octyl alcohol, decyl alcohol, dodecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol, and oleic alcohol, and polyhydric alcohols include glycerin, pentaerythritol, sorbitan, and sorbitol. , glucose, etc. Polyalkylene glycols include polyethylene glycol, polypropylene glycol, polyoxyethylene polyoxypropylene block copolymer, polyethylene glycol monoalkyl ether, polypropylene glycol monoalkyl ether, etc. Polyvinyl alcohol includes partially saponified or There is fully saponified polyvinyl alcohol, aromatic alcohols include benzyl alcohol, cinnamyl alcohol, etc., and examples of phenols include phenol,
Examples include cresol, catechol, and 2,2-bis(4'-hydroxyphenyl)propane. As described above, the specified alcohol or phenol that is effective in the present invention can be arbitrarily selected from alcohols or phenols with a boiling point of around 200°C or higher, and has a carbonyl bond in the molecule. Compounds are not preferred because they reduce the plating adhesion strength of resin-plated products. In the present invention, 0.1 to 10 parts by weight of a specified alcohol or phenol is added to 100 parts by weight of ABS resin, preferably 0.5 to 8 parts by weight, but if the amount of alcohol or phenol added is less than 0.1 part by weight, the adhesion of the plating The improvement effect is insufficient, and if it exceeds 10 parts by weight, it is not preferable because it not only lowers the plating adhesion strength but also impairs the rigidity and heat resistance of the ABS resin. The resin-plated product of the present invention is manufactured by subjecting a transparent ABS resin molded product manufactured by the above-mentioned technique to partial wet plating, but the wet plating can be performed by applying a known technique used for ordinary ABS resin. . In addition, in order to partially treat wet plating, it is sufficient to cover the non-plated parts with a masking material.
The technology is disclosed in, for example, Japanese Patent No. -124432, but the present invention is not limited to these technologies. The present invention will be specifically explained with reference to the following examples, in which all parts and percentages in the examples and comparative examples are expressed on a weight basis. The weight average particle diameters of the diene rubbers used in Examples and Comparative Examples were determined by the general formula Σnd ⁴ /Σnd ³ (n: number of particles, d: particle diameter). Example 1 and Comparative Example 1 Production of graft polymer A ₁ 560 parts of pure water in an autoclave, weight average particle diameter
60mμ small particle size poly(butadiene) latex
100 parts (as solids - 35% solids), 1.0 part potassium stearate, 0.015 part ferrous sulfate, 0.03 part sodium ethylenediaminetetraacetate, 0.9 part sodium formaldehyde sulfoxylate;
The mixture was heated to 50° C. with stirring. acrylonitrile here
A mixed solution consisting of 75 parts of styrene, 225 parts of styrene, 1.8 parts of t-dodecylmercaptan, and 0.6 parts of diisopropylbenzene hydroperoxide was continuously added over 5 hours. After the addition was completed, 0.3 part of diisopropylbenzene hydroperoxide was further added,
The polymerization was completed by stirring at 70°C for 2 hours. The yield is
It was 98%. Production of graft polymer B ₁ 270 parts of pure water in an autoclave, weight average particle size
550mμ large particle size poly(butadiene-styrene)
100 parts latex (as solids - 25% styrene content, 50% solids), potassium stearate 2.0
1 part, 0.005 part of ferrous sulfate, 0.01 part of sodium ethylenediaminetetraacetate, and 0.3 part of sodium formaldehyde sulfoxylate, and heated to 50°C under stirring.
heated to. Here, 25 parts of acrylonitrile, 75 parts of styrene, 0.6 parts of t-dodecylmercaptan, and diisopropylbenzene hydropoxide
A mixture consisting of 0.2 parts was added continuously over a period of 3 hours. After the addition was completed, 0.1 part of diisopropylbenzene hydroperoxide was further added, and the mixture was stirred at 70°C for 2 hours to complete the polymerization. The yield was 96%. Mixing and pelletization After mixing 28 parts of graft polymer A ₁ latex (as a solid content) and 1 part of graft polymer B ₁ latex (as a solid content) in a latex state, an aqueous calcium chloride solution is added to form a polymer. was recovered. 58 parts of this mixed graft polymer, 42 parts of acrylonitrile-styrene suspension copolymer (AS resin-acrylonitrile content 25%), and 2.0 parts of the additives shown in Table 1 were mixed and fed to an extruder. Made into pellets. This pellet is processed into IS80 CN manufactured by Toshiba Machine Co., Ltd.
Injection molding was carried out using a -V injection molding machine at a molding temperature of 240°C to obtain a flat molded product measuring 80 x 50 x 3 mm. Table 1 shows the total light transmittance of this molded product. Note that the total light transmittance was measured in accordance with ASTMD-1003. The letters "PLAY" were screen-printed on one side of the center of the molded product using a vinyl chloride resin masking ink, and the vicinity of the corresponding area on the back side was widely covered with the same masking ink, followed by wet plating according to the following steps. On the obtained metallurgical product, the word "PLAY" was clearly legible under transmitted light. "Wet plating process" Degreasing (isopropyl alcohol) room temperature x 5 seconds Etching (chromic anhydride-sulfuric acid mixture) 70℃
-15 minutes Neutralization (hydrochloric acid) room temperature x 2 minutes Catalyzing (palladium chloride-stannic chloride-hydrochloric acid aqueous solution) room temperature x 2 minutes Acceleration (sulfuric acid aqueous solution) 55℃ x 2
Minutes Chemical plating (Nickel sulfate - Sodium citrate - Sodium hypophosphite - Sodium acetate - Ammonium chloride aqueous solution) 32℃ x 5 minutes Electrolytic copper plating (20μ thickness) Electric nickel plating (7μ thickness) Chrome plating (0.3μ thickness) A resin-plated plate obtained by wet-plating the flat molded product without masking was left in an 85°C environment for 2 hours, and then immediately placed in a -40°C atmosphere for 2 hours. A transparent plate with 5 mm grids drawn on it was placed on the resin plating board after the heating-cooling cycle, and the number of grids from which the plating layer had peeled off was counted. The front and back surfaces of the resin-plated board were measured, and the number of peeled grids was summed up and defined as the "number of peeled-off squares." Table 1 summarizes the number of plating peelings of the samples. Experiment No. 6 (Comparative Example 1) in Table 1 is unfavorable due to poor plating adhesion. Example 2 and Comparative Example 2 In Example 1, the mixed graft polymer, AS resin,
and polyethylene glycol (average degree of polymerization 800)
The composition was changed to the ratio shown in Table 2 to obtain pellets. A molded article was made from the obtained pellets and partially plated in the same manner as in Example 1, and the word "PLAY" was clearly legible under transmitted light. Table 2 summarizes the total light transmittance of the molded product and the number of peelings of the resin plated plate obtained from the molded product. Table 2 Experiment Nos. 14 and 15 (Comparative Example 2) were unfavorable due to poor plating adhesion. Example 3 and Comparative Example 3 ABS resins having the compositions shown in Table 3 were prepared by varying the blending ratios of the graft polymer A ₁ , the graft polymer B ₁ and the AS resin in Example 1. When the ABS resin was partially plated in the same manner as in Example 1, the word "PLAY" was clearly legible under transmitted light, except for Experiment No. 20. Table 3 also shows the total light transmittance of the ABS resin molded product and the number of peelings of the resin plated plate. Table 3 Experiment No. 19 had poor plating adhesion, and
No. 20 lacks transparency and is both unfavorable. Example 4 Graft polymer B ₂ was obtained by polymerizing in the same manner as in Example 1 except that the weight average particle diameter of graft polymer B ₁ was changed to 200 mμ. Graft polymer A ₁ latex and graft polymer B ₂ latex were separately precipitated, and the resins were collected. Graft polymer A ₁ 56 parts, graft polymer B ₂ 2
1 part, 42 parts of the AS resin used in Example 1, and 2.0 parts of octedecyl alcohol were mixed and fed to an extruder to form pellets. A molded article was made from the pellet in the same manner as in Example 1, and when it was partially plated, the word "PLAY" could be clearly read by transmitted light. The total light transmittance of the molded product was 62.8%, and the number of peeled platings of the resin-plated plate obtained from the molded product was 33. Example 5 Graft polymer A ₂ was obtained by polymerizing in the same manner as in Example 1 except that the weight average particle diameter of graft polymer A ₁ was changed to 120 mμ. _Two latexes of graft polymer A and _one latex of graft polymer B were separately deposited, and the resins were collected. Graft polymer A ₂ 56 parts, graft polymer B ₁ 2
1 part, 42 parts of the AS resin used in Example 1, and 2.0 parts of octadecyl alcohol were mixed and fed to an extruder to form pellets. A molded article was made from the pellet in the same manner as in Example 1, and when it was partially plated, the word "PLAY" could be clearly read by transmitted light. The total light transmittance of the molded product was 47.8%, and the number of peeled platings of the resin-plated plate obtained from the molded product was 0. Example 6 Production of graft polymer _A3 280 parts of pure water in an autoclave, weight average particle size
60mμ small particle size poly(butadiene) latex
Add 100 parts (as solids - 35% solids), 1.0 part of potassium stearate, 0.0075 parts of ferrous sulfate, 0.015 parts of sodium ethylenediaminetetraacetate, and 0.45 parts of sodium formaldehyde sulfoxylate and heat to 50°C with stirring. did. To this, 5 parts of a mixed solution consisting of 37.5 parts of acrylonitrile, 112.5 parts of styrene, 1.5 parts of t-dodecylmercaptan, and 0.3 parts of diisopropylbenzene hydroperoxide was added.
It was added continuously over time. After addition, add 0.15% diisopropylbenzene hydroperoxide
The polymerization was completed by stirring at 70°C for 2 hours. The yield was 98%. Mixing and pelletizing After mixing 17.5 parts of graft polymer A ₃ latex (as solid content) and 1 part of graft polymer B ₁ latex (as solid content) in a latex state, an aqueous calcium chloride solution was added to form the polymer. was recovered. Example 1 was added to 37 parts of this mixed graft polymer.
63 parts of AS resin and 2.0 parts of polyethylene glycol (average degree of polymerization 800) were mixed and fed to an extruder to form pellets. A molded article was made from the obtained pellets and partially plated in the same manner as in Example 1, and the word "PLAY" was clearly legible under transmitted light. The total light transmittance of the molded product was 59.8%, and the number of peeled platings of the resin-plated plate obtained from the molded product was 16. Comparative Example 4 Production of Graft Polymer A ₄ 100 parts of pure water in an autoclave, weight average particle diameter
60mμ small particle size poly(butadiene) latex
Add 100 parts (as solids - 35% solids), 1.0 part of potassium stearate, 0.0025 parts of ferrous sulfate, 0.005 parts of sodium ethylenediaminetetraacetate, and 0.15 parts of sodium formaldehyde sulfoxylate and heat to 50°C with stirring. did. A liquid mixture consisting of 12.5 parts of acrylonitrile, 37.5 parts of styrene, 0.5 part of t-dodecylmercaptan, and 0.1 part of diisopropylbenzene hydroperoxide was continuously added thereto over a period of 2 hours. After the addition was completed, 0.05 part of diisopropylbenzene hydroperoxide was further added, and the mixture was stirred at 70°C for 2 hours to complete the polymerization. The yield was 97%. Mixing and pelletization After mixing 10.5 parts of graft polymer A ₄ latex (as solid content) and 1 part of graft polymer B ₁ latex (as solid content) in a latex state, an aqueous calcium chloride solution was added to form the polymer. was recovered. To 23 parts of this mixed graft polymer, the method of Example 1 was added.
77 parts of AS resin and 2.0 parts of polyethylene glycol (average degree of polymerization 800) were mixed and fed to an extruder to form pellets. A molded product made from the obtained pellet according to Example 1 had many silver streaks on the surface and was not a material that could be used in practical use. Comparative Example 5 Graft polymer A ₅ was obtained by polymerizing in the same manner as in Example 1 except that the weight average particle diameter of graft polymer A ₁ was changed to 200 mμ. Graft polymer A ₅ latex and graft polymer B ₁ latex were separately deposited, and the resins were collected. Graft polymer A ₅ 56 parts, graft polymer B ₁ 2
1 part, 42 parts of the AS resin used in Example 1, and 2.0 parts of octadecyl alcohol were mixed and fed to an extruder to form pellets. A molded product made from this pellet according to Example 1 had a total light transmittance of 0%. Comparative Example 6 In Example 6, mixed graft polymer, AS resin,
and polyethylene glycol (average degree of polymerization 800)
The composition was changed to the ratio shown in Table 2 to obtain pellets. Table 4 shows the results of moldings made from the obtained pellets and evaluation of their physical properties.

【table】

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[Table] Example 7 In Example 1, 58 parts of the mixed graft polymer, 42 parts of AS resin, and 2.0 parts of the additives shown in Table 5 were mixed,
It was fed into an extruder and pelletized. Moldings were made from the obtained pellets, and were partially plated in the same manner as in Example 1 and evaluated. The evaluation results are summarized in Table 5.

【table】

Claims (1)

[Claims] 1. The copolymerization amount of the diene rubber is 5 to 30% by weight, and the diene rubber is a mixture of large particles and small particles with a weight average particle diameter of 150 mμ, and The proportion is 80 to 99% by weight of small particles with a weight average particle diameter of 150 mμ or less,
To 100 parts by weight of a transparent ABS resin containing 1 to 20% by weight of large particles with a weight average particle diameter of over 150 mμ, aliphatic alcohols with 8 or more carbon atoms, polyhydric alcohols, polyvinyl alcohols, aromatic alcohols, phenols, cresols, catechol, and A resin-plated product obtained by partially wet-plating a molded product of an ABS resin composition containing 0.1 to 10 parts by weight of a compound selected from 2,2-bis(4'-hydroxyphenyl)propane.