JPH0233236Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] The present invention relates to a film cartridge container body that can be made thin and has good fitting and sealing properties. [Prior art] Conventionally, film cartridge containers have been made of high-density polyethylene, homopolypropylene, or other materials with a melt index (MI) of around 10 g/10 minutes in order to ensure rigidity and prevent burrs and strings during injection molding. Polystyrene was used. Furthermore, for various reasons such as ensuring compressive strength and drop strength, airtightness, and fluidity of molten resin during injection molding, the container body as well as the cap are made thick, which poses problems in the amount of resin used. There was also a problem with the incidence of defective products due to shots during injection molding. In addition, there was a problem with the strength of the fit between the cap and the container body. In addition, Japanese Utility Model Publication No. 58-46413 discloses a film cartridge container made of a thin metal sheet material, but metal containers are not only expensive to manufacture, but plastic containers are not suitable for mass production. It is not currently implemented. [Purpose of the invention] The present invention solves these problems and provides a film cartridge container body that is thin, easy to manufacture, and has high fitting and sealing properties, and is characterized by using a specific material of plastic. It is said that [Structure of the invention] That is, the invention consists of a polymer with a content of propylene units of 70% by weight or more, contains a light blocking substance of 0.1 to 3% by weight, has an MI of 16 to 80 g/10 minutes, and has a tensile yield rate of 16 to 80 g/10 minutes. Point stress is 250Kg/ ^cm2 or more, bending modulus is
The average thickness of the peripheral wall is 10000Kg/cm ² or more, and the notched Izo impact strength at 20℃ is 2.0Kg・cm/cm or more.
The present invention relates to a container body for a film cartridge of 0.4 to 1.2 mm. The test method is MI (ASTM D
1238), tensile yield point stress (ASTM D 638),
Based on flexural modulus (ASTM D 790) and 20°C notched Izot impact strength (ASTM D 256). The polymer that is the main component of the resin forming the container body may have a propylene unit content of 70% by weight or more, such as homopolypropylene, preferably 12% by mole or less of ethylene units, particularly preferably 5% by weight or less of ethylene units. Less than mol% ethylene. Propylene random copolymer and block copolymer, α of C ₄ to C ₁₀
- random and block copolymers with propylene containing less than 30% by weight of olefin units;
Furthermore, they include blend polymers with various polymers. The light-shielding substance is kneaded into the above polymer to impart light-shielding properties to the polymer, and includes carbon black, cadmium red, cadmium yellow, cadmium orange, iron oxide, cobalt blue, cobalt violet, and titanium oxide. , barium sulfate, barium carbonate, clay, kaolin, talc, calcium carbonate, inorganic pigments such as ultramarine, metal powders such as iron powder, aluminum powder, lead powder, magnesium powder, tin powder, zinc powder, copper powder, and phthalocyanine blue. , phthalocyanine pigments such as first sky blue and phthalocyanine green, and organic pigments such as quinacridone pigments. In addition, all known coloring pigments for the above-mentioned polymers can be used. From the viewpoint of film cartridge container strength and light-shielding properties, the amount added is 0.1 to 3% by weight.
A suitable amount is preferably about 0.2 to 1% by weight. In particular, barium compounds such as barium sulfate and barium carbonate, lead compounds such as lead powder and lead oxide, zinc compounds such as zinc powder and zinc oxide, tin powder and tin compounds such as tin oxide are used as light-shielding substances. It is particularly preferable for high-sensitivity negative films (ASA 200 or higher) because it can also exhibit an X-ray blocking effect. In this case, the amount added is preferably as large as possible without deteriorating the strength, preferably 0.1 to 40% by weight, particularly 10 to 20% by weight. Two or more light-shielding substances may be used in combination. The resin has an MI of 16-80 g/10 min, preferably 20-80 g/10 min.
60 g/10 minutes, particularly preferably 30 to 50 g/10 minutes, tensile yield point stress of 250 Kg/cm ² or more, preferably 300 Kg/cm ² or more, and flexural modulus of 10000 Kg/cm ² or more, preferably 15000 Kg/cm 2 or more. cm ² or more, and the notched Izo impact strength at 20°C is 2.0 Kg・cm/cm or more. A resin having such physical properties can be obtained, for example, by adding an appropriate amount of an organic or inorganic nucleating agent to the above-mentioned polymer. Organic nucleating agents include carboxylic acids, dicarboxylic acids, salts and anhydrides thereof, salts and esters of aromatic sulfonic acids, aromatic phosphinic acids, aromatic phosphonic acids, aromatic carboxylic acids, their aluminum salts, and aromatic phosphoric acids. Acid metal salts, alkyl alcohols having 8 to 30 carbon atoms, condensates of polyhydric alcohols and aldehydes,
and alkylamines, such as p-
Aluminum t-butylbenzoate, 1,3,2,
4-Dibenzylidene sorbitol, a di-substituted benzylidene sorbitol compound represented by the following formula (In the formula, R ₁ and R ₂ are alkyl having 1 to 8 carbon atoms,
It is alkoxy or halogen, m and n are both 0 to 3, and m+n≧1. ), metal salts of stearyl lactic acid such as calcium and magnesium, and compounds represented by the following formula such as N-(2-hydroxyethyl)-stearylamine. (In the formula, R ₃ is an alkyl group having 8 to 30 carbon atoms, k and l are both 0 to 10, and k+l
≧1. ), metal salts such as lithium salts, sodium salts, potassium salts, calcium salts, and magnesium salts of 1,2-hydroxystearic acid, alkyl alcohols such as stearyl alcohol and lauryl alcohol, sodium benzoate, benzoic acid, sebacic acid, etc. include. Inorganic nucleating agents include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide, alkali metal oxides such as sodium oxide, lithium carbonate, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. alkaline earth metal hydroxides such as calcium hydroxide, magnesium hydroxide, barium hydroxide, and alkaline earth metal oxides such as calcium carbonate and calcium oxide. The nucleating agent is not limited to these, and other known nucleating agents can also be used. Moreover, it goes without saying that the nucleating agent is not limited to being used alone, and that two or more types can be used in combination. The amount of nucleating agent added is 0.01 per 100 parts by weight of the polymer.
~2.0 parts by weight is appropriate. The nucleating agent may be added to the polymer by a general method of adding various additives to polypropylene or the like, and usually, the nucleating agent may be added to the polymer and kneaded uniformly. Various effects can be obtained by adding this nucleating agent. For example, 100 parts by weight of a random copolymer of propylene and ethylene as a polymer and P as a nucleating agent.
- By adding 0.1 part by weight of tert-butylbenzoic acid, the tensile yield stress can be increased from 380 Kg/ ^cm2 to 420 Kg/cm2.
It can be improved up to Kg/cm ² , but even if more is added, there will be little improvement after that. Also,
For example, when 0.1 part by weight is added, the bending elastic modulus is 500.
It can be improved by Kg/cm ² to 600 Kg/cm ² , but even if more than that is added, there will be little improvement after that. The shape of the container body of the present invention is not particularly limited as long as it can accommodate the film cartridge, but it is preferable that the shape of the container main body can sufficiently fit and seal with the cap and that the cap can be easily attached and detached. In this respect, for example, the example shown in FIG. 1 and the example shown in FIG. 2 are suitable. In particular, the one shown in FIG. 1 has the advantage of being easy to open with one hand. The wall thickness of the container body 1 can be made thinner than that of conventional products; for example, the wall thickness of the peripheral wall portion 2 is approximately 0.4 to 1.2 mm, preferably approximately 0.5 to 1.0 mm. The material of the cap 3 is preferably one that is more flexible than that of the container body 1 in order to fully exhibit these functions of the container body 1; for example, low-density polyethylene is suitable. The container body may normally be manufactured by injection molding. The injection molding method is not particularly limited, and for example, an in-mold vacuum method may be used. The mold is one that has multiple cavities rather than one mold, for example, one
It is more efficient to use a mold that can mold 12 or more container bodies at once. Further, it is more efficient to use a multistage mold such as a stack mold (double stacked mold, etc.). In the case of injection molding, as shown in FIGS. 1, 2, and 3, a resin protrusion 5 remains in the resin injection port 4, and the resin injection port 4 is 0.5 mm from the bottom surface 6. ~5mm or so, preferably 1~3mm
The inventor has found that pinholes are likely to form in this portion 4, especially when manufacturing the container body 1 of the present invention. In order to avoid this, it is preferable that the area around the resin injection port 4 be thicker than the average thickness of the bottom 7 as shown in the figure.
This means that the thickness of the container body 1 can be reduced, for example.
This is especially important when the thickness is 0.7 mm or less. When the thickness of the container body 1 is 0.9 mm or less, the thickness of the fitting part 8 is 5% or more than that of the peripheral wall part 2, as shown in Figs. 1 and 3, in order to improve compressive strength, degree of fitting, and moisture resistance. It is preferable to make it thick. Needless to say, the method for molding the container body is not limited to injection molding, and may be molded by injection blow molding, blow molding, or the like, if necessary. [Effects of the Invention] The container body of the present invention can be made thin due to the high strength of the material, and has good fitting and sealing properties with the cap. As a result, the amount of resin used can be reduced. Furthermore, since the resin has good fluidity, the molding speed can be increased and the occurrence of molded products can be reduced. Also compressive strength, degree of fit, moisture permeability,
MI (resin fluidity), drop strength, etc. have been improved, so compared to the conventional product, even if the wall is made more than 20% thinner by making the shape as shown in the representative examples in Figures 1 and 3, The quality is the same or better, and the test results for the structural product shown in Figure 3 show that a container body for film cartridges with no quality problems was obtained even if the wall thickness was reduced by more than 30%. [Example] Nestal (product name) manufactured by Sumitomo Heavy Industries was used as a molding machine
Using a mold squeezing force of 150 t, the number of molds being 24, and the runner type being a hot runner, a cartridge main body with a side wall thickness of 0.9 mm was molded in the shape shown in Figure 3. The comparative product is made of a polymer with a propylene unit content of 94 mol% and an ethylene content of 6 mol%, contains 0.5% by weight of carbon black, has a melt index of 12.3 g/10 minutes, and has a tensile stress at yield of 270.
A random type polypropylene resin containing no nucleating agent was used, which had a bending elastic modulus of 9800 Kg/cm ² , a notched Izot impact strength at 20° C. of 3.5 Kg/cm ² , and did not contain a nucleating agent. The content of propylene units is 96 as the product of this invention.
Consists of a polymer with a mol% ethylene content of 4 mol%, contains 0.5% by weight of carbon black, has a melt index of 40.0 g/10 minutes, and has a tensile stress at yield of 370.
Kg/cm ² , flexural modulus 14000Kg/cm ² , notched izot impact strength at 20℃ 5.0Kg・cm/cm
A random type polypropylene resin containing a nucleating agent was used. Table 1 was obtained by comparing the two.

【table】

【table】 [Brief explanation of the drawing]

The drawings all represent embodiments of the present invention, and FIGS. 1, 2, and 3 are cross-sectional views of the container body and the cap. DESCRIPTION OF SYMBOLS 1... Container body, 2... Surrounding wall part, 3... Cap, 4... Resin injection port part, 8... Cap fitting part.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of a polymer with a propylene unit content of 70% by weight or more, containing a light blocking substance of 0.1 to 3% by weight, and having a melt index of 16 to 80 g/10 minutes;
A peripheral wall formed using a resin having a tensile yield point stress of 250 Kg/cm ² or more, a flexural modulus of 10000 Kg/cm ² or more, and a notched Izo impact strength at 20°C of 2.0 Kg cm/cm or more. Film cartridge container body with an average thickness of 0.4 to 1.2 mm. (2) The film cassette container body according to claim 1, wherein the resin contains a nucleating agent. (3) The film cartridge container body according to claim 1, wherein the wall thickness near the resin injection port is thicker than the average wall thickness. (4) The scope of the utility model registration claim, Paragraph 1~, in which the cap fitting part is 5% or more thicker than the peripheral wall part.
The film cartridge container body according to item 3.