JPH0660280B2 - Camera parts - Google Patents

Description

The present invention relates to a camera part made of polycarbonate, which is excellent in dimensional accuracy and rigidity, and particularly excellent in appearance.

[Prior Art] Camera assembly parts are required to have precision, dimensional stability, and appropriate rigidity. Black-colored glass fiber reinforced aromatic polycarbonate resin has been used as a molding material that satisfies this requirement, but in recent years, cameras have come to be required to have not only functions but also decorativeness as accessories, and therefore, for assembly thereof. Precision, dimensional stability, appropriate rigidity, and aesthetic appeal have come to be required for parts.

Camera parts molded from black colored aromatic polycarbonate resin have excellent precision and appearance, but have insufficient dimensional stability and are molded from black colored glass fiber reinforced aromatic polycarbonate resin. Camera parts are excellent in precision, dimensional stability, and rigidity, but they have problems in appearance.
In order to solve this, the camera's milled fiber was used alone or in combination with chopped strands, and the camera part was molded with glass fiber reinforced aromatic polycarbonate resin colored in black. Is not enough for.

[Object of the Invention] An object of the present invention is to provide a camera part made of aromatic polycarbonate, which is excellent in dimensional accuracy and rigidity, and particularly excellent in appearance.

The camera parts in the present invention are usually resin parts, and typical examples thereof include a body, a front cover, a back cover, and a bottom cover.

[Structure of the Invention] The present invention comprises 99.5 to 95.0% by weight of an aromatic polycarbonate and an acrylic acid ester as main components, and copolymerizes butadiene in a weight less than the acrylic acid ester, and further, if necessary, a methacrylic acid ester. Acrylic ester type two-stage obtained by graft-polymerizing two or more kinds of monomers selected from the group consisting of methacrylic acid ester, styrene and acrylonitrile in two stages with a copolymerized acrylic acid ester type rubber as a trunk component. Grafted elastic polymer 0.5
100 parts by weight of a mixture of ~ 5.0% by weight and 5 glass fibers
It is a camera part obtained by molding a composition containing about 50 parts by weight and 1 to 3 parts by weight of carbon black.

The aromatic polycarbonate used in the present invention is 2
Average molecular weight derived from polyhydric phenol 10,000 to 100,00
The polycarbonate is 0, preferably 15,000 to 60,000, and is usually produced by a solution method or a melting method of a dihydric phenol and a carbonate precursor. A typical example of the dihydric phenol is bisphenol A [2,2-bis (4-
Hydroxyphenyl) propane], bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxy-3-methylphenol) propane and the like. A preferred dihydric phenol is a bis (4-hydroxyphenyl) alkane compound, especially bisphenol A. The dihydric phenols can be used alone or in combination of two or more. Examples of the carbonate precursor include carbonyl halide, carbonate, haloformate and the like.

Representative examples include phosgene, diphenyl carbonate, dihaloformates of dihydric phenols and mixtures thereof.

Appropriate molecular weight modifiers, branching agents, catalysts, etc. can be used in the production of aromatic polycarbonate.

The acrylic elastic polymer used in the present invention comprises an acrylic acid ester as a main component, which is copolymerized with a smaller amount of butadiene than the acrylic acid ester, and optionally with a methacrylic acid ester. An acrylic acid ester-based two-stage graft elastic polymer obtained by graft-polymerizing two or more kinds of monomers selected from the group consisting of methacrylic acid ester, styrene and acrylonitrile in two stages with an ester rubber as a trunk component. There are, for example, alkyl acrylates having 2 to 12 carbon atoms in the alkyl group (eg, 2-ethylhexyl acrylate,
-Butyl acrylate, etc.) 40-95 wt% and butadiene 5
-40% by weight and methylmethacrylate 0-30% by weight and 0.
A crosslinked rubber copolymer having an average particle size of 0.1 to 0.3μ obtained by emulsion-polymerizing a mixed monomer consisting of 01 to 3% by weight of a crosslinking agent (for example, ethylene dimethacrylate etc.) and adding a coagulant thereto. Add styrene 20 to latex containing ~ 80 parts by weight.
Polymerization by addition of 10 to 40 parts by weight of mixed monomer of -80% by weight, methyl methacrylate 20 to 50% by weight, acrylonitrile 0 to 60% by weight, and crosslinking agent (eg ethylene dimethacrylate, divinylbenzene etc.) 0.1 to 2% by weight After that, the alkyl group containing 0.1 to 4% by weight of a cross-linking agent (eg, ethylene dimethacrylate, divinylbenzene, etc.) has a carbon number of 1 to 1
It is a multi-component resin obtained by further adding and polymerizing 5 to 25 parts by weight of alkyl methacrylate (for example, methyl methacrylate) of 4. Specific examples of such an acrylic elastic polymer include those commercially available under the product name HIA-15 from Kureha Chemical Industry Co., Ltd.

The glass fiber used in the present invention may be any glass fiber that is usually used for polycarbonate. A preferable glass fiber has a diameter of 6 to 20 μm, and the length of the glass fiber in the molded product is 0.05 to 0.5 mm. Further, the glass fiber may be subjected to a surface treatment with a silane coupling agent or the like for the purpose of improving the affinity with the resin, and a focusing treatment with an acrylic resin, a urethane resin or the like for the purpose of improving the handleability.

The carbon black used in the present invention may be any carbon black that is usually used for polycarbonate. As a specific example, carbon black M from Mitsubishi Kasei Co., Ltd.
A-100, MA-600, MA-950, etc. can be mentioned.

The camera component of the present invention can be obtained by molding a mixture of the above four components. The mixing ratio is 99.5-95.0% by weight of aromatic polycarbonate, more preferably 99.0%.
~ 97.0% by weight and acrylic elastic polymer 0.5 to 5.0% by weight,
More preferably, it is in the range of 5 to 50 parts by weight of glass fiber and 1 to 3 parts by weight of carbon black with respect to 100 parts by weight of the mixture composed of 1.0 to 3.0% by weight.

If the amount of the acrylic elastic polymer exceeds 5.0% by weight, the rigidity of the molded article becomes insufficient, and if it is less than 0.5% by weight, the appearance is insufficient.

If the amount of glass fiber exceeds 50 parts by weight, molding becomes difficult and the appearance becomes poor, and if it is less than 5 parts by weight, rigidity and dimensional stability are insufficient.

If the amount of carbon black is less than 1.0 part by weight, light leakage is likely to occur, and an amount exceeding 3 parts by weight is not necessary.

Known methods can be applied to mixing and molding. For example, the above-mentioned four kinds of components are mixed with a tumbler, a V-type blender, a Nauter mixer or the like, and pelletized as it is or through an extruder, and then mainly molded by injection molding.

Further, a stabilizer and a release agent may be added in an effective amount during mixing or molding within a range that does not impair the object of the present invention.

[Effects of the Invention] Since the camera component of the present invention thus obtained is excellent in dimensional accuracy and rigidity, and particularly excellent in appearance, the camera assembled using this can give the customer sufficient satisfaction. .

[Examples] The present invention will be described in detail below with reference to Reference Examples and Examples.

Reference Examples 1 to 5 Aromatic Polycarbonate (Teijin Kasei Co., Ltd .: Panlite L-1250) (indicated by PC in the table), acrylic elastic polymer (Kureha Chemical Industry Co., Ltd .: HIA-15), glass fiber ( Nippon Spinning Co., Ltd.) and carbon black MA-100 (Mitsubishi Kasei Co., Ltd.) were mixed in a blender in the proportions shown in Table 1 and then a 30 mmφ vent type extruder (Nakatani Co., Ltd.)
(Manufactured by: VSK-30), and extruded at a cylinder temperature of 300 ° C to form pellets. After drying the pellets at 120 ° C for 8 hours, an injection molding machine (Sumitomo Cycap S480 / 15
0) was used to mold a 6.4 mm × 12.7 mm × 127 mm bending test piece under the conditions of a cylinder temperature of 320 ° C. and a mold temperature of 110 ° C., and the bending elastic modulus was measured. Further, a molded article described in the evaluation method was obtained under the same conditions, and the appearance was evaluated by the evaluation method described below.

The results are shown in Table-1.

Evaluation method Also the flow of glass fiber: A sample plate with a hole was formed near the gate to make the flow of resin turbulent, and the degree of inconspicuousness of the flow of glass fiber was visually evaluated in three levels.

◯ (Difficult to stand out) Δ (Slightly noticeable) × (Conspicuous) Floating of glass fiber: A 90 mm × 50 mm × 2 mm square plate was formed, and the floating of the glass fiber was visually evaluated on the basis of three levels.

Good (not noticeable) (somewhat noticeable) x (noticeable) Reference Example 4 A similar molded product was obtained and measured by the same method as in Reference Example 1 except that the acrylic elastic polymer was omitted. Shown in.

Reference Example 5 A similar molded product was obtained and measured by the same method as in Reference Example 1 except that glass fiber was omitted. The results are shown in Table-1.

Examples 1 to 3 Using the molding die for the front cover of the camera shown in FIG. 1, molding was carried out in the same manner as in the reference example, and evaluated by the evaluation methods described below. The results are shown in Table-2.

Evaluation method Floating of glass: The floating of the glass was evaluated in three levels by visually observing the surface.

◯ (Difficult to stand out) Δ (Slightly stand out) × (Conspicuous) Molding shrinkage ratio: The dimensions were measured by a three-dimensional measuring machine (FJ-604 manufactured by Mitoyo Co., Ltd.) and evaluated.

Comparative Example 1 A similar molded product was obtained and measured by the same method as in Example 1 except that the acrylic elastic polymer was omitted. The results are shown in Table-2.

Comparative Example 2 A similar molded product was obtained and measured by the same method as in Example 1 except that glass fiber was omitted. The results are shown in Table-2.
Although this has a good appearance, it is not suitable as a camera part because of insufficient rigidity.

[Brief description of drawings]

FIG. 1 is an example of a camera component of the present invention. Part A is embossed (Japan Etching HN-21) and B
The part is diamond cut. 125m for each of i, ro, and ha
m, 10mm, 75mm.

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Claims (1)

[Claims] 1. Aromatic polycarbonate 99.5-95.
0% by weight, acrylic acid ester as a main component, butadiene in a smaller amount than the acrylic acid ester was copolymerized therewith, and further acrylic acid ester-based rubber obtained by copolymerizing methacrylic acid ester as a main component was used as a trunk component. Acrylic ester-based two-stage graft elastic polymer 0.5-5.0 weight by which two or more kinds of monomers selected from the group consisting of methacrylic acid ester, styrene and acrylonitrile are graft-polymerized in two stages. % Mixture 100
A camera part obtained by molding a composition in which 5 parts by weight of glass fiber, 5 to 50 parts by weight of glass fiber, and 1 to 3 parts by weight of carbon black are mixed.