JPH0514738B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to an ABS resin composition that is particularly excellent in plating film strength and heat cycle resistance. <Conventional technology> Conventionally, ABS resin has been the mainstream resin used for plating, and its plating film is beautiful, the plating film has high peel strength, and it also has excellent heat cycle resistance. Since then, it has established a solid position in the application of plastic plating. However, recently, the demand for improved heat cycle resistance has become more severe, especially for automotive applications, and the reality is that existing plating grades cannot meet the requirements. For example, specifically, it is required that the appearance of a plated product does not change even if it is subjected to heat cycles of -40°C to 85°C 3 to 10 times. To increase the adhesion strength of the plating film
Publication No. 6222 proposes a method of adding a styrene-butadiene block copolymer to ABS resin, but although this method increases the adhesion strength of the plating film, the smoothness of the molded product surface is lost. Or,
There were many problems such as the molded product being easily damaged, and it was not practical. A heat-resistant ABS composition that can be plated by adding an organosilicon compound to heat-resistant ABS or a heat-resistant ABS alloy has been proposed in JP-A-56-81355 and other publications. <Problems to be Solved by the Invention> This heat-resistant ABS containing organosilicon compounds exhibits extremely excellent heat-resistant cycling properties, but since the matrix resin layer of the heat-resistant resin is difficult to be etched,
This method has problems such as a narrow range of etching conditions and the addition of an organosilicon compound, which leads to a decrease in the rigidity of the molded product. <Means for Solving the Problems> In view of this situation, the present inventors have found that the plating film has excellent heat cycle resistance and peeling strength, and that the plating condition width that allows plating is lower than that for conventional plating.
As a result of intensive research with the aim of providing a composition that has desirable characteristics as a plating composition, such as being wider than ABS and having fewer bleeds during molding, we found that ABS alloy, styrene-butadiene copolymer and fluorine-based We discovered that by using a surfactant in combination with the addition of a small amount of fluorine-based surfactant, it is possible to obtain an excellent ABS composition for plating that has no practical problems in both heat-resistant and general applications. This has led to the present invention. That is, the present invention provides: (1) a graft copolymer (A) 5 in which an aromatic monovinyl monomer and a vinyl cyanide monomer are partially graft-polymerized to 15 to 75 parts by weight of prebutadiene latex; ~95 parts by weight and (2) styrene containing 5 to 45 parts by weight of styrene.
(3) 95 to 5 parts by weight of a graft copolymer (B) obtained by partially graft-polymerizing an aromatic monovinyl monomer and a vinyl cyanide monomer to 15 to 75 parts by weight of a butadiene copolymer latex; A mixture of 0 to 85 parts by weight of a copolymer (C) obtained by copolymerizing 50 to 85 parts by weight of an aromatic monovinyl monomer and 50 to 15 parts by weight of a vinyl cyanide monomer ((A)
+ (B) + (C) (total of 100 parts by weight)) (4) A resin composition for plating having excellent heat cycle resistance and containing 0.01 to 3.0 parts by weight of a fluorine-containing surfactant. It is. The present invention will now be described in detail. The resin used in the present invention can be obtained as follows. The aromatic monovinyl monomers used in the present invention include aromatic monovinyl monomers such as styrene, α-methylstyrene, vinyltoluene, O-ethylstyrene, O,P-chlorostyrene, and vinyl cyanide monomers. As the monomer, acrylonitrile, methacrylonitrile, ethacrylonitrile, etc. are used. The composition ratio of monomers in emulsion graft polymerization is
The aromatic monovinyl monomer and the vinyl cyanide monomer can be mixed in any ratio, but the ratio is preferably that of the aromatic monovinyl monomer and the vinyl cyanide monomer.
60 to 80% by weight, vinyl cyanide monomer 40 to 20% by weight. The graft copolymer (A) used in the present invention is prepared by first charging 15 to 755 parts by weight, preferably 30 to 70 parts by weight, of polybutadiene latex into a polymerization tank, and then continuously removing unreacted monomers. Obtained by supplying. The polymerization initiator is oil-soluble,
Either water-soluble one may be used, or they may be used in combination. The graft copolymer (B) used in the present invention can be produced in the same manner as the graft copolymer (A). Further, although the polybutadiene latex and the styrene-butadiene copolymer latex may be individually graft-polymerized, it is also possible to blend them in advance and then subject them to graft polymerization. According to this method, the graft polymers (A) and (B)
can be manufactured at the same time. Any method can be used to obtain the resin from the polymer latex. For example, the polymer latex may be coagulated with mineral acid, electrolyte, etc., and the polymer may be recovered by filtering, washing, dehydration, and drying. . In the resin powder thus obtained, the proportion of rubbery polymer in the final resin component is preferably 5 to 30% by weight.
Styrene-acrylonitrile copolymer, α-
A mixture of graft polymer (A), (B) and copolymer (C) can be obtained by blending methylstyrene-acrylonitrile copolymer etc. and kneading with a Banbury mixer, rolls, extruder, etc. . Graft copolymer (A) and graft copolymer (B) are
They can be blended at any weight ratio within the range of 5/95 to 95/5, but for example, when the styrene content of the styrene-butadiene copolymer latex of the graft copolymer (B) is 25%, 40~/60~90/
10 is preferred. If the content of the graft copolymer (A) is too low, it is difficult to develop impact resistance, while if the content of the graft copolymer (B) is too low, the effect of improving heat cycle resistance becomes small. Preferred fluorosurfactants used in the present invention include perfluoroalkyl carboxylates,
perfluoroalkylethylene oxide adduct,
Examples include surfactants that have perfluoroalkyl groups, such as oligomers containing perfluoroalkyl groups, hydrophilic groups, and lipophilic groups, and fluorine-based surfactants that partially contain fluorine. They may be used alone or in combination of two or more. Among the fluorine-based compounds, those effective in the present invention are:
Anything that can be used as a surfactant,
Surfactants having a large ability to lower the surface tension of water or solvents, such as perfluorinated compounds, are particularly effective. The amount of fluorine-based surfactant to be added is 0.01 to 3.0
part, preferably 0.03 to 2.0 parts.
If it is less than 0.01 part, the effect of improving heat cycle resistance will be small, and if it is more than 3.0 parts, it will bleed onto the surface of the molded product, causing mold stains or weakening the adhesion strength of the plating film. The thermoplastic resin composition for plating of the present invention can be prepared by blending a fluorine-containing surfactant with a granular thermoplastic resin or a blend of intermediate raw materials, or by using a Banbury mixer, a roll,
It can be obtained by kneading with an extruder or the like. It is preferable to add the fluorosurfactant when blending the intermediate raw materials of the thermoplastic resin, but if it is unavoidable, it can also be blended into the thermoplastic resin particles. In that case, in order to improve kneading in the extruder, the thermoplastic resin particles may be crushed in advance before use. During blending, in addition to the fluorine-containing surfactant, commonly used stabilizers, plasticizers, pigments, etc. can be added as necessary. The finally obtained resin composition can be molded by injection molding, extrusion molding, or other molding methods, and then plated using conventional plating equipment suitable for each resin. <Examples> The method of the present invention will be explained in detail below using examples. Note that the heat cycle resistance, peeling strength, and impact strength used in the examples were measured according to the following methods. Parts in the examples are parts by weight. Heat cycling resistance: After leaving the plated product (175 mm x 35 mm x 90 cm, 2 mm thick, 4-point gate box) at room temperature for 24 hours,
Place in the oven at 85℃ and leave for 1 hour. Take out,
Leave at room temperature for 15 minutes, then immediately place in -40°C freezer for 1 hour. This process is carried out for a total of 3 cycles (15 minutes at room temperature → 85℃, 1 hour → 15 minutes at room temperature → -40℃, 1 hour), and there is no change in the appearance of the plating film or the shape of the molded product before and after the test. Examined. Peeling strength: Peel off the plating film from a square plate (126 x 75, 3 mm thick) plated with matte copper to a thickness of 25 to 40 μ over a length of 80 mm with a width of 25 mm, and calculate the average Peel strength was measured. Since the peeling load varies depending on the thickness of the plating film, the peeling strength when the plating film thickness is 30 μm was determined from the following formula. P=Pt (30/t) ^3/4 W Kg/cm) P: Peeling strength (Kg/cm) Pt: Average peeling load (Kg) t: Plating film thickness (μ) W: Peeling width (cm) Physical properties : Physical property values such as impact strength were determined in accordance with ASTM test methods. (1/2″ IZOD: ASTM D-256) <Example> Examples 1 to 8 Polybutadiene latex “BR-1” (Toray
Co., Ltd., average particle size 0.36μ), sodium pyrophosphate,
Glucose and ferrous sulfate were charged into 20 reaction vessels with the composition shown in Table 1. The temperature was raised to 60°C, a chain transfer agent, a monomer, and an emulsified oil-soluble initiator were continuously added, and polymerization was completed in 7 hours. After adding an antioxidant, the polymerized latex was coagulated with sulfuric acid, neutralized with caustic soda, filtered, washed, dehydrated, and dried to recover a uniform powder (hereinafter referred to as PB-1). Styrene-butadiene latex is SBR-
1 (stainless steel content 25%, average particle size 0.60μ) was used. Polymerization was carried out under the same graft polymerization conditions as in the case of using BR-1, and a uniform powder was obtained by post-treatment in the same manner (hereinafter referred to as SB-1). Hereinafter, SB-2 to SB-5 were obtained by changing the charging composition as shown in Table 1 under the same graft polymerization conditions. The diluting resin composition was bulk polymerized styrene-acrylonitrile copolymer SAN-1 (AN/manufactured by Toray Industries, Inc.).
S=28/72) was used. As a fluorine-based surfactant, perfluoroalkyl carboxylate (Dainippon Ink & Chemicals Co., Ltd.)
A resin composition was obtained containing 0.05 part of "Megafac F-120", manufactured by Kogyo Corporation. The method for adding F-120 was to add it simultaneously with a lubricant and an antioxidant at the time of blending intermediate raw materials, ie, high-rubber-containing ABS and AS resins, and to stir and mix with a mixer. The mixture is
The mixture was pelletized using a vented extruder to obtain a uniform resin composition. The obtained resin composition was molded and then plated. The etching solution used was a sulfuric acid/chromic acid mixture normally used for ABS resin. The process order of Metsuki is chemical for heat cycle resistance evaluation.
Ni plating → electric Ni plating was used, and for peeling strength evaluation, chemical Ni plating → electrolytic copper plating was used. The results are shown in Table 1. The heat cycle resistance of this plating film was outstanding, and the peeling strength was equivalent to that of a general plating grade of ABS. SBR as styrene-butadiene latex
Resin composition when using -2 (Examples 3 to 4)
The heat cycle resistance of the plating film was outstanding. As styrene-butadiene latex,
Resin composition when using SBR-3 (Example 5
The heat cycle resistance of the plating film of items 6) to 6) was excellent. In addition, styrene-butadiene latex SBR
-2, SBR-3, SBR-4, and SBR-5 were as follows. SBR-2: Styrene content 25%, average particle size 0.37μ SBR-3: 〃 12%, 〃 0.56μ SBR-4: 〃 40%, 〃 0.68μ SBR-5: 〃 55%, 〃 0.28μ Styrene-butadiene As rubber latex,
When SBR-4 (styrene content: 40%, average particle size: 0.68 μm) was used, the heat cycle resistance of the plating film of the resin compositions (Examples 7 to 8) was excellent. Examples 9 to 10 As a fluorine-based surfactant, a perfluoroalkyl ethylene oxide adduct (“Megafauc F-142” manufactured by Dainippon Ink and Chemicals) or an oligomer containing a perfluoroalkyl group, a hydrophilic group, and a lipophilic group (large Nippon Ink Kagaku Kogyo “Mefuatsu F-”
A resin composition was obtained in the same manner as in Example 1, except that F-177") was used. The heat cycle resistance of the plating film of this product was greatly improved compared to the case where F-142 or F-177 was not added. Evaluation The results are summarized in Table 3. Comparative Example 1 Butadiene copolymer alone (PB-1) was evaluated without adding a fluorine-based surfactant. However, after the heat-resistant cycle, the plating film caused large blisters.
The smoothness of the plating film surface was impaired. Comparative examples are summarized in Table 4. Comparative example 2 Styrene-butadiene copolymer alone (SB-1)
Evaluation was made by adding 0.05 part of F-120 to 100 parts. The surface of the plating film on this product was cloudy and the impact resistance was low. Comparative example 3 Styrene-butadiene copolymer alone (SB-2)
Evaluation was made by adding 0.05 part of F-120 to 100 parts. This material had excellent plating properties, but poor impact resistance. Comparative Example 4 Polybutadiene graft copolymer (PB-1),
Styrene-butadiene graft copolymer (SB-
1) Added 0.005 parts to 100 parts of the combination system. The plating film heat cycle resistance of this product was poor. Comparative Example 5 F-120 was added to 100 parts of PB-1 and SB-1 combination system.
-120 was added in an amount of 5.0 parts. The plating film surface of this product is partially uneven;
The adhesion strength of the plating film was also low. Comparative Example 6 F-120 was added to 100 parts of styrene-butadiene graft copolymer alone (SB-3) with a styrene content of 12%.
0.05 part of was added. The surface of the plating film was cloudy. Comparative Example 7 0.05 part of F-120 was added to 100 parts of a graft copolymer (SB-4) produced using a styrene-butadiene copolymer with a styrene content of 40%. The surface of the plating film on this product was cloudy, and the impact resistance was extremely low. Comparative Example 8 As styrene-butadiene rubber latex
SBR-5 (styrene content 55%, average particle size 0.28μ) was used. Further, 0.05 part of F-120 was added to 100 parts of a blend of PB-1 and SB-5 at a ratio of 70/30. Although this material had excellent plating properties, its impact resistance was low. Comparative Example 9 Instead of the fluorosurfactant, 0.05 part of polytetrafluoroethylene resin was added for evaluation. The heat cycle resistance of this product was poor, and no effect of the addition of fluororesin was observed.

【table】

【table】

[Table] Appearance No gloss Slightly no gloss
Glossy except near the gate Glossy

【table】

【table】

[Table] <Effects of the Invention> The plating resin composition of the present invention has excellent plating film strength, heat cycle resistance, and peel strength, as well as good physical properties, particularly impact strength. Therefore, it is possible to obtain an excellent plated product that has no practical problems in both heat-resistant applications and general applications.

Claims (1)

[Scope of Claims] 1 (a) A graft copolymer (A) obtained by partially graft-polymerizing an aromatic monovinyl monomer and a vinyl cyanide monomer to 15 to 75 parts by weight of polybutadiene latex. Styrene containing 5 to 95 parts by weight and (b) 5 to 45 parts by weight of styrene.
95 to 5 parts by weight of a graft copolymer (B) prepared by partially graft polymerizing an aromatic monovinyl monomer and a vinyl cyanide monomer to 15 to 75 parts by weight of a butadiene copolymer latex; c) A mixture of 0 to 85 parts by weight of a copolymer (C) obtained by copolymerizing 50 to 85 parts by weight of an aromatic monovinyl monomer and 50 to 15 parts by weight of a vinyl cyanide monomer ((A) )
A resin composition for plating having excellent heat cycle resistance for plating film, which contains (d) 0.01 to 0.3 parts by weight of a fluorine-containing surfactant per 100 parts by weight of +(B)+(C).