JP2002131874A - Method for manufacturing recycling of injection-molded article for photographic sensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deterioration of photographic properties of recycle parts for photographic sensitive materials. SOLUTION: Resin parts such as front and rear covers and a main body base part or the like of a film unit with a lens are crushed once, regenerated by injection molding by using regenerated resin pellets in which crushed crushing materials are re-pelletized as a part of raw materials, and used as the recycle parts. When the crushing materials are heated and melted at the time of injection molding, performance and quality of the recycle parts are deteriorated compared with new parts due to the heat deterioration or the transmutation of a thermoplastic resin. Also, in the case of the heat deterioration of the thermoplastic resin, more harmful gas that exerts an adverse influence on the photographic properties is generated by the chemical reaction with the photographic sensitive materials. To prevent this heat deterioration, by using an injection molding machine 50 in which a bent port 66 is provided on a heating cylinder 53, the injection molding is carried out by exhausting the harmful gas generated from a molten resin through the bent port 66.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a production method for recycling injection molded articles for photographic photosensitive materials, and more particularly, to a method for recycling used injection molded articles for photographic photosensitive materials. The present invention relates to a recycle production method for pulverizing the powder into a material, and then using the material for injection molding to recycle the material.

[0002]

2. Description of the Related Art A film unit with a lens is well known as a packaging unit containing a photographic material. The lens-fitted photo film unit is composed of an unexposed photo film cartridge and a unit main body containing the photo film cartridge and having a simple photographing mechanism.

[0003] Since the photographic photosensitive material must be housed in a light-tight manner as a component constituting the unit body, a thermoplastic resin composition having a light-shielding property has conventionally been used as a main constituent material thereof. And formed by injection molding. Hereinafter, these plastic molded parts are referred to as injection molded articles for photographic photosensitive materials.

[0004] The quality and performance required of the injection molded article for photographic light-sensitive materials are described in A.A. B. Completely ensuring light-shielding properties; C. Excellent heat resistance and weather resistance, no dimensional change or shape change due to temperature change or aging change, D. having sufficient fracture resistance; E. high flame retardancy; F. good moldability and few molding defects;
Inexpensive, G. It does not adversely affect the human body.

[0005] When the quality and performance of A to E are low, photographic properties are adversely affected. That is, the adverse effects on the photographic properties include fog, abnormal sensitivity, abnormal gradation, abnormal coloring, uneven density, etc., which occur in the photographic film.

The factors include, for example, deformation of an injection molded product and molding defects such as the occurrence of bumps such as resin on the surface of the molded product. Fog and film flaws occur. In addition, when the injection molded product is charged, static electricity is generated, and this static electricity generates a static mark (dendritic or blurred circular fog). In addition to these physical factors,
There are chemical factors such as a chemical reaction between a decomposition product such as gas generated from a resin molded product and a photographic film.

In order to satisfy the above-mentioned quality and performance, a resin serving as a base of an injection molded product for a photographic photosensitive material is selected,
Various additives are added to this resin. First, as the resin, for example, a polystyrene resin is generally used. Polystyrene resins are produced in large quantities because molded products have good dimensional stability and are inexpensive. Further, as the light-shielding substance, carbon black or the like is used.

[0008] However, ordinary polystyrene resins have insufficient physical strength such as erosion to a part of oils and organic solvents, weather resistance, heat resistance, and breaking strength, and are liable to be charged. There are disadvantages. Among these disadvantages, a rubber-containing polystyrene resin (an impact-resistant polystyrene resin or a high-impact polystyrene resin) obtained by graft copolymerizing a synthetic rubber such as butadiene rubber as an impact-resistant substance with a styrene monomer in order to improve the fracture resistance Etc.) are commonly used.

As additives to compensate for other disadvantages, there are lubricants for increasing the fluidity of the thermoplastic resin to improve moldability, antioxidants for preventing the thermoplastic resin and other additives from being thermally degraded, UV absorber to prevent photo-deterioration of thermoplastic resin, nucleating agent that plays a role in improving surface hardness, rigidity, Izod impact strength, and abrasion resistance, and prevents deterioration of physical strength of thermoplastic resin due to aging For example, an antioxidant, an antistatic agent, and a dispersant of a light-shielding substance for improving the light-shielding property by dispersing the light-shielding substance in a resin are mixed. These additives are added when new resin pellets are produced.

A new injection molded article for a photographic photosensitive material is injection molded using the new resin pellet as a raw material. Since the new resin pellets are heated and melted during injection molding, some of the additives mixed with the new resin pellets are dissipated and may be reduced or denatured. For this reason,
Additives are added to the new resin pellets in an amount that takes into account the decrease. By doing so, a new injection-molded product for a photographic light-sensitive material exhibits predetermined performance and quality.

By the way, in order to protect the environment and reduce industrial waste, the recycling of industrial products is being carried out. Regarding the photographic photosensitive material injection molded product, the collected molded product is crushed, the crushed crushed material is melted and stretched in a strand shape by an extruder, and this is cut back into pellets of a certain size. Recycling is carried out by re-injecting recycled resin pellets as a part of raw materials into a production line and injection molding recycled parts.

[0012]

However, when a performance test was conducted, it was found that the recycled product was inferior in photographic properties as compared with a new product. In particular, it has been found that in the case of a recycled product, the inconvenience that the photographic film suffers from fogging is higher than that of a new product. This deterioration in photographic properties is more likely to become apparent as the photographic film becomes more sensitive, and high-sensitivity photographic films have come to be used as photographic films stored in photographic film cartridges and film units with lenses. In recent years, this is a particular problem.

In the recycling step, the resin composition comprises:
Once heated and melted, it is returned to the raw material. Due to this heating and melting, thermal deterioration of the thermoplastic resin proceeds. It is considered that some of additives such as antioxidants for preventing thermal deterioration undergo some modification, resulting in deterioration of performance as compared with new products.

[0014] It was also found that compared with a new product, the recycled product generates a larger amount of harmful gas that adversely affects photographic properties. This is the recycling process
It is considered that the resin composition is heated to cause deterioration and deterioration.

In order to solve the above-mentioned problems, there is provided a method for recycling an injection molded article for a photographic light-sensitive material, which is devised so as to prevent deterioration of photographic properties of the stored photographic light-sensitive material as compared with a new one. With the goal.

[0016]

In order to achieve the above object, the present invention provides a method for recycling an injection molded article for a photographic photosensitive material, which comprises the steps of: Injection molding is performed by exhausting decomposition products generated from the molten resin and adversely affecting the photographic properties of the photographic material. The crushed material, that is, the recycled resin has been previously heat-melted many times by a molding machine or the like. In such a recycled resin, additives, especially antioxidants, are reduced as compared with a new resin, and the resin of the injection molded product contains a large amount of a rubber component. Product is generated. Therefore, the decomposition products are exhausted during injection molding. As a method of evacuating, it is preferable to attach a vacuum pump to the vent port and reduce the pressure in the vent port.

According to the second aspect of the present invention, a used resin part formed by injection molding of a thermoplastic resin is crushed,
2. An injection molding method for photographic photosensitive materials, wherein recycled resin pellets obtained by re-pulverizing crushed crushed materials into resin pellets by extrusion molding are used as at least a part of raw materials and injection molding is performed again by the molding machine according to claim 1 to produce recycled parts. This is a method for manufacturing recycled articles.

According to the third aspect of the present invention, the pressure in the vent port is reduced to a degree of vacuum of 130 Pa for injection molding. In this way, by reducing the pressure of the vent port to a degree of vacuum of 130 Pa, while preventing the hydrolysis due to the residual water in the resin and inconveniences such as vent-up, the decomposition products in the resin are plasticized and kneaded during the kneading. Can be forcibly excluded. According to a fourth aspect of the present invention, at least carbon black and an antioxidant are added as additives before injection molding to perform injection molding. The addition of these additives can suppress the generation of decomposition products.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A resource recycling type product will be described as a lens-fitted film unit shown in FIG. The film unit with lens 11 is composed of a unit main body 12 and a label 13 that partially covers the outer periphery of the unit main body 12, and the unit main body 12 is loaded with a photographic film in advance. Film unit 11 with lens
In front of the camera, a photographing aperture 16, which exposes the photographing lens 14,
In addition to the opening 17 for exposing the finder lens, a strobe opening for exposing the strobe light emitting portion 18 is formed. Below the strobe light emitting portion 18, a charging operation member 19 for strobe is provided. A shutter button 21, a film counter window 22, and the like, which are partially cut away and made elastic, are formed on the upper surface, and a winding knob 23 is exposed on the back side.

As shown in FIG. 2, the unit body 12
Main body base 26, strobe unit 27, exposure unit 2
8, a front cover 29 and a rear cover 31. The main body base 26, the front cover 29 and the rear cover 31
An outer cover of the unit body 12 is formed. These covers are plastic parts and are recycled at the resource recycling production plant to return to the raw materials once and reuse them again for hygiene and quality reasons (hereinafter referred to as "recycling").
).

An exposure frame 26a is formed in the center of the main body 26, and a cartridge chamber 26b in which a cartridge 32 is loaded on both sides thereof, and a film roll formed by rolling a photographic film 33 drawn from the cartridge 32. The film roll chamber 26c in which the film 34 is loaded is formed integrally. A winding knob 23 is rotatably mounted above the cartridge chamber. A drive shaft is formed on the winding knob 23. The drive shaft enters the cartridge chamber 26 b and engages with the spool of the cartridge 32.

The exposure frame 26a defines an exposure range for one frame on the front surface of the photographic film 33 sent to the photographing position. In front of the exposure frame 26a, a dark box base 26d protruding in a rectangular cylindrical shape is integrally formed. The dark box base 26d constitutes a dark box in which the space from the taking lens 14 to the exposure frame 26a is kept in a dark room in cooperation with the dark box section 28a on the exposure unit 28 side by assembling the exposure unit 28 to the main body base 26.

A rear cover 33 is detachably attached to the back of the main body base 26. Thus, a film feeding path is formed between the cartridge chamber 26b and the film roll chamber 26c. The photo film 33 is moved into the cartridge 32 by the film winding operation of the winding knob 23.
Is wound up. At this time, the photo film 33
From the film roll chamber 26c to the cartridge chamber 26b.
Sent toward At this time, the photographic film 33 comes into sliding contact with the rear cover 31 and the main body base 26.

The lower surfaces of the cartridge chamber 26b and the film roll chamber 26c are open, and these openings are closed by pull-top type bottom lids 31b, 31c formed by making a part of the rear cover 31 thin and openable. . Bottom lid 31b
Is a lid of the cartridge 32 in which the photographed photo film 33 is stored.

The strobe unit 27 includes a printed circuit board 3
Reference numeral 6 is a unit component to which a circuit element including a strobe charging circuit and the like, a strobe light emitting section 18, a synchro switch, a pair of battery contact pieces, and a main capacitor are mounted together. The strobe unit 27 is disposed between the exposure unit 28 and the film storage chamber 26c, and is detachably attached to the main body base 26 by claw engagement. The strobe circuit is
Power is supplied from the power supply battery 37.

The charging operation member 19 for turning on and off the charging of the flash circuit is mounted on the front surface of the printed circuit board 36. On the back of the charging operation member 19, a metal switch piece 3 is provided.
When the charging operation member 19 is pressed and operated, the switch piece 38 conducts the contact of the printed circuit board 36 to activate the strobe circuit.

The exposure unit 28 is based on a dark box 28a, and has a finder lens 41, a film counter mechanism, a shutter mechanism and a film unwinding mechanism on its upper part, and a shutter blade (not shown) and a shutter cover 42 on its front face. It is a unit part that incorporates and integrates these. The photographing lens 14 is detached and inspected independently.
It is detachably attached to the shutter cover 42 so that cleaning can be performed.

The film box stopping mechanism, shutter charging mechanism, film counter mechanism, finder optical system and the like are integrally incorporated in the upper part of the dark box section 28a. These parts are all made of plastic except for the spring.

The exposure unit 28, the photographing lens 14, and the strobe unit 27 are reused. In reuse, after cleaning and inspection, reuse is performed again. Those that fail the inspection are repaired and used again. For items that cannot be repaired,
It is sent to a plastic parts recycling line at a recycling production plant for recycling.

The above-mentioned plastic parts are provided on the rear cover 3.
1, and plastic parts directly contacting the photographic film 33 such as the main body base 26, and components constituting mechanisms such as the lenses 14, 41 and the winding knob 23, and the photographic film 33 such as the front cover 29 and the dark box 28a. Not divided into plastic parts. Of these, Photo Film 33
Naturally, the present invention is preferably applied to plastic parts that do not come into contact. This is because the gas generated from the resin component causes fogging and abnormal sensitivity in the photographic film. These plastic parts are molded by injection molding using a thermoplastic resin, and constitute the injection molded article for photographic photosensitive materials of the present invention.

Next, a case where an injection molded article for a photographic photosensitive material is newly manufactured will be described. First, a thermoplastic resin composition obtained by adding an additive to a thermoplastic resin is pelletized by a strand cut method. In the strand cut method,
The thermoplastic resin composition was melted, extruded in a string form with a porous die provided in an extruder, continuously cooled in a cooling water tank, and then drained with an air wiper, and then formed into a cylindrical shape with a strand cutter. It is cut into a pellet shape to produce a new resin pellet. The strand cutter sandwiches a string-like thermoplastic resin composition cooled by two rotating rubber rolls and takes it, and cuts the taken-out composition by a predetermined length by a rotary blade. New resin pellets are put into a production line as raw materials. In the production line, injection molded products for photographic photosensitive materials are produced by injection molding.

As additives, there are carbon black and antioxidants. The antioxidant has an action of suppressing generation of these harmful gases by preventing deterioration of the thermoplastic resin. Carbon black secures light-shielding properties.

At the time of injection molding, the new resin pellets are melted by heating, so that the additives dissipate and decrease. For this reason, when producing new resin pellets, an additive is added in an amount obtained by adding a decrease in the additive during injection molding. As a result, a predetermined amount of additive is contained in the new injection-molded photographic light-sensitive material, and the necessary performance and quality are secured.

Each new injection molded article for a photographic photosensitive material is supplied to a production line. Thus, a new lens-fitted film unit 11 is assembled. The assembled film unit with lens 11 is provided on the market. The used film unit with lens 11 is collected at the developing laboratory.

Next, the procedure of resource recycling production of the film unit with lens 11 will be described. The used film unit 11 with a lens can be transferred to a photographic film 33 at a photo lab.
And the cartridge 32 is taken out. The removed film unit with lens 11 is collected at a resource recycling production factory. Collected film unit 1 with lens
1 are sorted by product type and sent to a resource recycling production line prepared for each product type, as shown in FIG. The resource recycling production line includes a product disassembly line, a plastic parts recycling line, and a production line.

In the product disassembly line, the product is disassembled and separated for each material. First, after peeling off the cosmetic label 13, the front cover 29, the charging operation member 19, the winding knob 23, and the like are sequentially removed. These parts are sent to a plastic parts recycling line. After removing the front cover 29, the metal switch piece 38, the strobe unit 27,
The exposure units 28 are sequentially removed. The metal material such as the switch piece 38 is collected by a metal collection company and recycled. The exposure unit 28, the lenses 14, 41, and the strobe unit 27 are reused. The power battery 37 is
Collected by a battery collector. Finally, the remaining body base 2
6 and the rear cover 31 are separated and sent to a plastic parts recycling line. Here, the front cover 29, the charging operation member 19, the winding knob 23, the main body base 26, and the rear cover 3
1 and the lenses 14 and 41 that cannot be reused are made of thermoplastic resin parts of the same material, and therefore are sent to a plastic parts recycling line. In a plastic parts recycling line, carbon black and an antioxidant are added to recycle plastic parts.

As described above, in the product disassembly line, reuse parts such as metal parts and electric parts are removed from the product, and the remaining parts including plastic are sent to the plastic part recycling line. The plastic component recycling line is supplied with components including plastic such as the rear cover 31, the front cover 29, and the main body base 26 to which a light-shielding substance such as carbon black has already been added.

As shown in FIG. 4, the plastic part recycling line includes a raw material recycling line and a part molding line. In the raw material recycling line, thermoplastic resin parts of the same material are crushed by a crusher, and the crushed crushed material is re-pelletized to generate recycled resin pellets.

The raw material recycling line includes a rough crushing step, a dissimilar material separating step, a washing step, a drying step, a fine crushing step, a melt extrusion step, and a cutting step. In the coarse crushing step, the thermoplastic resin component is crushed into a relatively large shape by a crusher machine. After the coarse crushing, the coarsely crushed material is sent to a different material separation step, where metal pieces and plastic materials having different specific gravities are separated by the different material separator. Then, in the washing process, the coarsely crushed material is washed, and in the drying process,
After drying, it is finely crushed in a fine crushing step. By washing the crushed material, substances harmful to the photographic film, for example, sand, iron powder, general dust, oil, adhesive of adhesive tape, aqueous magic ink, etc. are washed away.

The crushed material is melted by an extruder, and the melted thermoplastic resin composition is extruded into a strand. This strand resin is cooled and solidified by cooling water. The solidified strand-shaped resin is cut into a predetermined size and pelletized, thereby producing recycled resin pellets. As the extruder, a vent type extruder is used.
The vent type extruder extrudes while removing monomers, water, solvents and entrained air contained in the material,
It has a structure in which the molten material is temporarily brought into a reduced pressure state to discharge gaseous volatile components.

When the thermoplastic resin is heated and melted by extrusion molding or injection molding, it is thermally decomposed and deteriorates or deteriorates.
Performance and quality are reduced. Further, when the crushed material is heated and melted, additives such as an antioxidant and a release agent added at the time of producing a new resin pellet undergo some deformation, for example, molding failure occurs, light shielding ability and the like are reduced. Sometimes. Further, when the thermoplastic resin is thermally decomposed, decomposition products are generated which adversely affect the photographic properties of the photographic light-sensitive material.
Decomposition products are harmful gases such as ketones, sulfur compounds and cyanide compounds.

The antioxidant has an action of preventing the deterioration of the thermoplastic resin. Due to the heating and melting of the crushed material, the antioxidant added during the production of the new resin pellets may disappear and decrease. Recycled products will generate more decomposition products than new products. In order to prevent the performance and quality of the recycled parts from being deteriorated due to the heating and melting, carbon black and an antioxidant are added when the recycled resin pellets are formed.

Carbon black secures light-shielding properties of plastic parts. Further, the carbon black has a function of adsorbing or capturing a decomposition product generated during holding during molding. In order to improve the ability to adsorb or capture this decomposition product, for example, carbon black having a small particle size is used. Small particle size means that
It is preferable to increase the surface area for adsorption, and the adsorption or trapping ability is improved. The average particle size of the carbon black is not particularly limited, but is preferably from 10 to 80 nm, particularly preferably from 16 to 24 nm.

The types of carbon black include:
There are various types as described above. The carbon black to be added at the time of recycling is appropriately selected from among these various carbon blacks and those having different physical properties such as the particle size and specific gravity, and a mixture of these carbon blacks is used.

As described above, the antioxidant has a function of preventing the thermal deterioration of the thermoplastic resin and additives, maintaining the performance and quality thereof, and preventing the generation of decomposition products caused by the heat deterioration and deterioration. Have. It is also known that the effect of preventing thermal degradation is further improved by using an antioxidant and carbon black in combination.

As described above, there are various antioxidants. As the antioxidant to be added at the time of recycling, similarly to carbon black, an antioxidant is appropriately selected from various antioxidants, and a mixture of a plurality of types of antioxidants is used.

Further, the type of carbon black and antioxidant added to the new resin pellets may be different depending on the production time of the product and the type of the product. Plastic parts used in used products are usually crushed by mixing those with different manufacturing times and product types.Therefore, carbon black and antioxidants contained in the crushed crushed materials are also various. Are mixed. Carbon black and antioxidants added at the time of recycling are required to have properties peculiar to recycled products, such as suppression of the generation of decomposition products. Therefore, carbon black and antioxidants already contained in crushed materials are required. May be used, or the same type may be used as long as the carbon black or antioxidant already contained in the crushed material satisfies the property. .

The recycled resin pellets thus recycled are supplied to a component molding line as raw materials. In the component molding line, recycled components are made by mixing injection molding with recycled resin pellets and new resin pellets or using 100% recycled resin pellets as raw materials, and using these as raw materials by injection molding.

In the injection molding, as shown in FIG. 5, an in-line screw molding machine is used to mold a photographic photosensitive material injection molded part. The molding machine 50 includes an injection unit 51 and a mold clamping unit 52. Injection unit 5
1 includes a heating cylinder 53, a band heater 54, a screw 55, a hopper 56, a nozzle 57, a screw driving mechanism 58, an injection cylinder 59, and control units 60 and 61. The hopper 56 is loaded with recycled resin pellets and new resin pellets. These thermoplastic resins are supplied to the heating cylinder 53 by the hopper 56. The heating cylinder 53 incorporates a screw 55, and melts the resin by heating the band heater 54 wound around the outer periphery and shearing heat generated when the screw 55 rotates, and injects the resin by the advance of the screw 55 itself.

The nozzle 57 is located at the end of the heating cylinder 53 and contacts the sprue bush 64 of the mold 63 to form a flow path for the molten resin to the mold 63. Screw drive mechanism 5
Reference numeral 8 denotes a mechanism for applying a rotational force to the screw 55, and includes a hydraulic motor and a speed reduction mechanism. The injection cylinder 59 is a hydraulic cylinder for moving the screw 55 forward or backward, and gives the screw 55 an injection pressure, a back pressure, and an injection speed. The control unit includes a hydraulic control unit 61 and an electric control unit 60.
Consists of The hydraulic control unit 61 supplies drive to a hydraulic cylinder and a hydraulic motor, and includes a power source such as an electric motor and a pump, hydraulic control components such as a pressure control valve, a direction switching valve, and a flow control valve, a strainer, a cooler, and a hydraulic control unit. It consists of piping, an oil tank, and the like. The electric control unit 60 includes a heater circuit for controlling the temperature of the heating cylinder 53 and the nozzle 57, an operation control circuit, a power control circuit (motor circuit), a changeover switch, a limit switch, a timer, a relay, and the like. And the like are controlled solely or continuously. Further, the time and amount of each operation are determined, and the hydraulic control unit 61 is determined.
Rotation direction of the screw 55 through the solenoid of the
Control force and speed.

In the first stage corresponding to the range of the first screw, the resin is melted. The molten resin is
It is injected at the second stage corresponding to the range of the screw. A vent port 66 is provided in a vent portion indicating a range where the resin changes from a softened state to a molten state. A vacuum pump 68 is connected to the vent port 66 via a filter 67. From the vent port 66, volatile components such as air, gas, and moisture in the molten resin are discharged to the outside of the heating cylinder 53 via the filter 67 by continuous suction of the vacuum pump 68. The recycled resin pellets of the present embodiment are repeatedly heated and melted many times by recycling. In such a recycled resin pellet, a decomposition product such as a gas and a gaseous substance harmful to the photographic film 33 is generated from the resin containing the rubber component due to a decrease in the antioxidant. According to the molding machine of the present embodiment, the decomposition product is supplied to the vent 6
6 can be eliminated (degassed).

The recycled product molded by the molding machine, that is, the injection molded product for photographic light-sensitive material, is supplied to a production line to assemble the product. Recycled injection-molded products for photographic light-sensitive materials contain carbon black and antioxidants, so even when compared to new ones,
The performance and quality are not inferior, and the generation of decomposition products is suppressed, so that the photographic properties are not inferior.

In the above example, the carbon black and the antioxidant are added at the time of forming the recycled resin pellets. However, the carbon black and the antioxidant may be added at the time of injection molding, not at the time of forming the recycled resin pellet. Further, carbon black and an antioxidant may be added in two stages, that is, during the production of the recycled resin pellets and during the injection molding.

In the plastic parts recycling line described with reference to FIG. 4, the crushed material is again extruded into a cylindrical pellet by extrusion. However, the pellet is not limited to the cylindrical shape. It may be in the form of a tablet, a convex lens, or the like that can be obtained by using a cutting method. Also,
A non-pelletized plastic parts recycling line may be used. For example, in the line shown in FIG. 6, the crushed material is not pelletized, and the regenerated crushed material that has been finely crushed, then washed and dried is supplied to the part forming line as a part of the raw material. The recycled crushed material is used by being mixed with other raw materials (recycled resin pellets or new resin pellets). When the recycled crushed material is used as a raw material, the carbon black and the antioxidant are added at the time of injection molding. According to this,
The use of recycled crushed material as a raw material has the advantage of reducing the recycling cost by omitting the pelletizing step.

As described with reference to FIG. 5, the molding machine is an in-line screw type in which the steps of plasticization and injection are performed by a single screw in a rotating operation and a forward / backward moving operation. The present invention is not limited to this, and a pre-plunger plunger method in which well-known plasticization and injection are performed in separate steps may be used. In this pre-plunger method, a nozzle with a valve is attached to the tip of a cylinder containing an injection plunger. A branch pipe with a valve is connected to the cylinder by branching from the tip of the cylinder.
A heating cylinder is attached to the branch pipe. The heating cylinder contains a screw, and a hopper, a screw drive mechanism, and an injection cylinder are attached. In this case, by providing a vent port in the heating cylinder, photographic harmful gas can be degassed.

Further, in the above-described embodiment, the film-with-lens unit 11 has been described as a resource-recycling type product. However, the present invention is not limited to the film-with-lens unit, but may be used for photographic film cartridges, instant film units, and various roll films. The present invention can also be applied to packaging units for photographic photosensitive materials such as spools and cartridges, various sheet film packs, sheet film pack holders, sheet film units, and light-shielding magazines for loading sheet or roll photographic photosensitive materials into bright rooms.

It is not necessary to mold the original parts using recycled resin. For example, a photographic photosensitive material different from a lens-fitted film unit using a recycled resin obtained from a used lens-fitted film unit. Parts.

[0058]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Injection molded articles of the photographic light-sensitive material of the present invention are made into pulverized materials at the time of recycling, decomposed products are degassed when pelletized by an extruder, and carbon black is added to the pelletized recycled resin. And an antioxidant,
This is injected into a molding machine, and after decomposed products are degassed during melting of the resin in the molding machine, the resin is injected. Therefore, an experiment was conducted below to examine the effect of degassing the gas component in the extruder and the effect of degassing the gas component in the molding machine. [Experiment 1] In order to examine the effect of degassing of gas components in the extruder, sample 1 was a regenerated resin pellet produced by reducing the degree of vacuum at the vent port of the extruder to 130 Pa, and a regenerated resin pellet was produced without decompression. The resin pellet was used as Sample 2. In each case, the film unit with the lens collected from the market is disassembled, and the plastic parts taken out are washed and pulverized to produce a pulverized material, and an additive is added to the pulverized material and then input into an extruder. The extruder has a screw diameter (D)
= 100 mm, L / D = 28 (L = effective screw length). The extrusion temperature in the extruder was 230 degrees. The carbon black as an additive has an average particle size of 24 nm, P
H = 8.0 and nitrogen adsorption specific surface area = 110 m ² / g were used. For evaluation, the sample and the color photographic film were individually placed in a special container capable of maintaining a temperature of 50 ° C. and a humidity of 60%, and after being left for one week, the photographic film was subjected to a developing process to measure a change in a fogging density by color of the film. did. In addition, as a color photograph film, JIS135 type, I
A negative color film having an SO sensitivity of 800 and taking 27 images was used.

[Table 1] The fog density index is better as the value is smaller, and has no effect when the value is “0”. From the above experimental results, it was found that the use of recycled resin pellets depressurized by the extruder gave higher evaluation of photographic properties. [Experiment 2] Two kinds of molded articles were prepared by using a molding machine according to the presence or absence of the reduced pressure using the sample 1 prepared by reducing the pressure of the regenerated resin pellets with an extruder, and photographic properties were obtained in the same manner as described above. An evaluation was performed. As a molding machine, a molding machine manufactured by Sumitomo Heavy Industries (manufacturer name) having a mold clamping force of 50 t was used. A vacuum plasticizer (Alfin system manufactured by Sumitomo Heavy Industries) (trade name) is attached below the hopper of the molding machine. The molded product has dimensions of 3 × 3 × 3t (mm). The special container contained a plurality of 500 g of molded articles and a photographic film. The mold used was a cold mold. Decompression was performed at a degree of vacuum of 130 Pa. A molded article molded under reduced pressure is designated as Sample 3, and a molded article molded without pressure reduction is designated as Sample 4.

[Table 2] From the experimental results, although no large difference was obtained, it was found that the molded product molded under reduced pressure in the B phase had higher evaluation of photographic properties. It is considered that the reason why a large difference did not appear in the fogging density index was that the resin was not melted under the hopper, and the pressure was reduced to degas the gas here.

[Experiment 3] Using the recycled resin pellet of Sample 1 above, a front cover of a film unit with a lens,
The body base and the rear cover are each molded into two types according to the presence or absence of decompression and deaeration, and a negative color film is built in with these molded parts to assemble two types of lens-equipped film units. The evaluation was made on the photographic fogging by the method. The molding machine is Toshiba Machine 1S13
Type 0F (trade name) was used. Vacuum deaeration was performed at a vent port provided in a vent portion. The degree of vacuum is 130 Pa
And The molded product molded by degassing under reduced pressure is designated as Sample 5, and the molded product molded without decompression is designated as Sample 6.

[Table 3] As a result of the above experiment, in the case of the sample 5, there was a slight occurrence of an object, which was at a practically acceptable level. On the other hand, the sample 6 has a practically marginal level in the B phase, but has a problem in the G phase and the R phase, and is therefore totally rejected. From the results of these experiments, it was found that it is desirable to mold a molded article by reducing the pressure of the vent port with a molding machine using regenerated resin pellets produced by reducing the pressure with an extruder.

Next, specific examples of the thermoplastic resin composition obtained by adding an additive to a crushed material are shown below. As the thermoplastic resin composition, a light-shielding substance for imparting light-shielding properties is preferably added and used.

If necessary, thermoplastic elastomers, lubricants, antistatic agents, drip-proofing agents, flame retardants, ultraviolet absorbers, metal deterioration inhibitors, compatibilizers, inorganic or organic pigments, processing aids, fillers Additives such as antioxidants, modifiers, antioxidants, fragrances, desiccants, desiccants, chelating agents, inorganic or organic nucleating agents, plasticizers, etc. The types and addition amounts which do not adversely affect the photographic properties may be selected in accordance with the photographic light-sensitive material to be applied, and may be contained alone or in combination of two or more types in the resin pellet.

The thermoplastic resin used for the resin material of the injection molded product for photographic photosensitive materials is preferably
Polyethylene (PE), polypropylene (PP), various homopolyethylene resins, various ethylene copolymer resins, homopolypropylene resins, propylene / α-olefin copolymer resins produced by polymerization using a multisite polymerization catalyst by a conventionally known method. , Homopolystyrene resin, synthetic rubber-containing polystyrene resin, ABS resin, acrylonitrile
Styrene resin, AAS (ASA) resin, AES resin (weather-resistant, impact-resistant resin), syndiotactic polystyrene resin, various polyethylene resins polymerized and produced using single-site catalyst, polyolefin-based thermoplastic elastomer, and single-site Homopolypropylene resin, propylene / α-olefin copolymer resin (random type or block type) polymerized and produced using a catalyst, homopolyethylene resin of various densities, ethylene / α-olefin copolymer resin of various densities, polystyrene resin, etc. Is mentioned.

Examples of the styrene resin include general-purpose polystyrene resin, impact-resistant polystyrene resin (also referred to as synthetic rubber graft-polymerized polystyrene resin or high-impact polystyrene resin and abbreviated as HI polystyrene resin), styrene-acrylonitrile Resins, styrene-acrylonitrile-butadiene resin, AES resin, styrene-methyl methacrylate-acrylonitrile resin, acrylonitrile-acrylic rubber-styrene resin, styrene-butadiene block copolymer resin, styrene-maleic anhydride copolymer resin, and the like. Can be

The high-impact polystyrene resin, which is particularly preferred among the thermoplastic resins described above, is inexpensive and has excellent injection moldability. Such a styrenic resin contains 0.01 to 5% by weight of a lubricant, 1 to 10% by weight of a synthetic rubber having an average particle size of 1.5 to 5 μm, and 0.001 to 1.0% by weight of an antioxidant. % And a light-shielding substance in the range of 0.1 to 10% by weight, respectively.

The styrenic resin used in the present invention may contain other monomers such as propylene, butene-1, pentene and 4-methylpentene as long as their performance is not impaired.
Α-olefins such as 1, hexene, octene and decene, dienes such as butadiene and isoprene, cycloolefins such as cyclopentene, cyclohexene and cyclopentadiene, and acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate are copolymerized. May be.

In addition to those described above, the thermoplastic resins particularly preferred in the present invention are excellent in various properties (physical strength, rigidity, heat resistance, abrasion resistance, etc.), and are particularly stable at high temperatures. If it is, any type may be used and is not limited. For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN),
Aromatic polyester resin composed of aromatic dicarboxylic acid such as polybutylene naphthalate (PBN) and diol or oxycarboxylic acid, nylon 6, nylon 6
6, polyamide 6-10, nylon 12, polyamide resin such as nylon 46, ethylene, propylene, olefin resin containing butene as a main component, homopolystyrene,
Styrene-butadiene copolymer, styrene-acrylonitrile copolymer, styrene resins such as ABS, polycarbonate resin, polyphenylene oxide resin, polyalkyl acrylate resin, polyacetal resin, polysulfone resin, polyether sulfone resin, polyphenylene sulfide resin, Examples thereof include a polyetherimide resin, a polyetherketone resin, and a fluorine resin. Further, these thermoplastic resins may be used by mixing two or more kinds of arbitrary resins. Especially good compatibility 2
A polymer alloy obtained by melt-kneading at least one kind of thermoplastic resin is particularly preferable because of its excellent physical properties and good appearance.

In the present invention, each of the above-mentioned homopolymer resins, two or more copolymer resins, or
A blend of two or more of these homopolymers and copolymer resins may be used, or a polymer alloy may be used, but the invention is not limited thereto. Polymer blending methods are classified into physical Brent, chemical Brent, and polymer complex, and may be a blend blended by any method.

As the processing aid, a metal salt of a fatty acid such as zinc stearate or the like, or a metal mold releasing agent such as stearic acid amide is preferable. As the filler, calcium carbonate, mica, titanium oxide and the like are preferable. As the modifier, silicone is preferable for its effects such as lowering of surface friction and antistatic effect.

It is desirable that the thermoplastic resin used in the present invention is mixed with a thermoplastic elastomer as an impact-resistant substance for increasing the physical strength of the molded article. The thermoplastic elastomer also has a function of improving the dispersibility of the light-shielding substance of the additive. As the dispersibility of the light-shielding substance is improved, a sufficient light-shielding property can be obtained without increasing the content of the light-shielding substance, which is effective in increasing the physical strength. As the thermoplastic elastomer, various types such as styrene, ester, olefin, vinyl chloride, amide, crystalline 1,2 polybutadiene, ionomer, fluorine, urethane, isoprene, etc. are appropriately used. Can be.

Next, a light-shielding substance which imparts a light-shielding property to a thermoplastic resin may adversely affect the photographic properties depending on the type of the photographic light-sensitive material, the ISO sensitivity, etc. The molding conditions require careful selection of sugar. Specifically, light-absorbing carbon black, titanium titanium, graphite, and iron black, which are less likely to adversely affect photographic properties and are thermally stable, are preferable as the light-shielding substance. In particular, carbon black is 20
It is thermally sufficient even at about 0 degrees, is harmless to the human body, can be incinerated, has a thermal stabilizing effect on thermoplastic resin, and has a discoloration and surface when injection molded. It is most preferable because there is no change and no deterioration in physical strength.

Carbon black is classified into furnace black, acetylene black, gas black, channel black, anthra black, Ketjen black, thermal black, lamp black, oil smoke, pine smoke, animal black, vegetable black and the like according to the raw material. . Among these carbon blacks, furnace carbon black is preferable for the purpose of ensuring light-shielding properties, reducing costs, improving physical properties, etc., and is an acetylene carbon black or a modified auxiliary carbon black in that it is expensive but has an antistatic effect. Ketjen carbon black and conductive furnace carbon black (Vulcan X
C-72 etc.) are also preferred. It is also preferable to use the former and the latter in combination as needed.

As the light-shielding substance used in the resin material composition constituting the injection-molded article for a photographic light-sensitive material, fog does not occur in the photographic light-sensitive material, the change in the photosensitivity is small, and the light-shielding ability is large. From the viewpoint that buttocks (lumps of light-shielding substance) are not easily generated when added to a thermoplastic resin,
H (measured by JIS K 6221) is 6.0 to 9.0, average particle diameter (measured by an electron microscope) is 10 to 120 nm, particularly 10 to 10 nm.
80 nm carbon black is preferred. Furthermore, among carbon blacks, volatile components (measured by JIS K 6221)
Is 2.0% or less, DBP oil absorption (oil absorption A of JIS K 6221)
Furnace carbon black (measured by a method) of 50 ml / 100 g or more is preferable in that it has good photographic properties, improves light-shielding properties, improves dispersibility, improves antistatic properties, and has little decrease in physical properties.

In order to suppress the adverse effect on the photographic properties of the photographic light-sensitive material, it is preferable that the content of the sulfur compound or the cyan compound in the injection molded product is as small as possible. The sulfur content of the carbon black (according to ASTM D 1619-60 measurement method) is 0.9% or less, preferably 0.6% or less, particularly preferably 0.4% or less, most preferably 0.2% or less. Good to do.

Next to carbon black, preferred light-shielding substances are inorganic pigments having a refractive index of 1.50 or more as measured by Larsen's oil immersion method and various metal powders, metal flakes, metal pastes, metal fibers and carbon fibers. Preferred refractive index is 1.
Representative examples of 50 or more inorganic pigments and metal powders are shown below,
The present invention is not limited to these. ()
The numbers in the parentheses indicate the refractive index.

Further, due to the recent boom in overseas travel, when a high-sensitivity photographic film having an ISO sensitivity of 400 or more is passed through an inspection machine using X-rays in baggage inspection at an airport, fog is easily generated by X-rays. In order to prevent this, it is preferable to use a light-shielding substance having a specific gravity of 3.1 or more, preferably 3.4 or more. Specific gravity of 3.1 or more, preferably 3.
The form of the light-shielding substance having an X-ray shielding property other than the light-shielding property of 4 or more, particularly preferably 4.0 or more, is not limited to those exemplified below as typical examples, and any form, for example, pigment, powder, flake, whisker, It may be a fiber or the like.

From the viewpoints of improving injection moldability, ensuring the quality of the injection molded product, securing light-shielding properties, securing physical strength, securing photographic performance of the photographic photosensitive material, economical efficiency, etc., the light-shielding substance in the injection molded product is The preferred total content is 0.05 to 40% by weight. However, this content varies as appropriate depending on the light-shielding ability of the light-shielding substance and the thickness of the injection-molded article. Therefore, the total content of the light-shielding substance may be appropriately adjusted according to the light-shielding ability of the light-shielding substance to be used. In the case of carbon black, titanium oxide, and aluminum powder having excellent light-shielding ability, light-shielding properties and economical efficiency are required. The total content is preferably 0.05 to 20% by weight, more preferably 0.1 to 15% by weight, and particularly preferably 0.15 to 10% by weight, from the viewpoint of the balance of physical strength, injection moldability and the like. %, Most preferably 0.2-5% by weight.

If the total content is less than 0.05% by weight, unless the thickness of the injection-molded product is made very large, the light-shielding ability becomes insufficient and light fog occurs. In addition, if the thickness of the injection molded product for a photographic photosensitive material is increased in order to obtain a sufficient light-shielding property with this content, the injection molding cycle of the injection molded product for a photographic photosensitive material becomes longer (because the cooling time becomes longer). ), Sink mark (sink mark), warpage and torsion are likely to occur, and the amount of resin used is large and expensive, so that practical use is difficult.

On the other hand, if the content exceeds 40% by weight, the dispersibility deteriorates, the generation of microgrids (agglomerated impurities) increases, and pressure fog and scratches are generated on the photographic material. The amount of water in the material injection molded product increases due to the increase in the amount of water adsorbed on the carbon black,
The photographic properties of the photographic material are adversely affected (fog generation, abnormal sensitivity, abnormal coloring, etc.). Further, the injection moldability of the injection molded product for photographic photosensitive materials is deteriorated (molding failure such as foaming, silver stripes, burning, pinholes, short shots, etc. is caused) and the physical strength is reduced, and practical use is difficult.

The resin composition containing a light-shielding substance contains 0.05% by weight of volatile components (mostly water) in the resin composition.
It is preferable to use the photographic material after drying as described below in order to suppress the adverse effect on the photographic properties of the photographic light-sensitive material and to suppress the occurrence of foaming and silver stripes to prevent the deterioration of the injection moldability. It is more preferably at most 0.04% by weight, particularly preferably at most 0.03% by weight, most preferably at most 0.02% by weight. The resin composition may be dried by heating, vacuuming, or heating / vacuum (eg, drying at 70 ° C. for 3 hours).

Further, the thermoplastic resin composition of the present invention includes:
Various additives can be added. Additives can be divided into a first category (classification according to performance for needs) and a second category (classification according to attributes of compounding agents). The first category includes processing aids, modifying compounds, performance modifiers (physical property control agents), function modifiers (function imparting agents), and decomposition accelerators. Processing aids include processing stabilizers (antioxidants, heat stabilizers, PVC stabilizers), flow control agents (plasticizers, lubricants), and shape-retaining assistants (mold release agents, anti-shrinkage agents). is there.
The modifying compounding agent is classified into a stabilizer (life controlling agent), a performance modifying agent (physical property controlling agent), a function modifying agent (function imparting agent), and a decomposition accelerator. Stabilizers include antioxidants, light stabilizers, flame retardants, biostabilizers, and degradation repair agents. Performance modifiers include impact modifiers (elastomer, rubber, L-LDPE resin, etc.), fillers and reinforcing materials, coloring agents, plasticizers, foaming agents, cross-linking agents (organic oxides), and molding agents. There is a nucleating agent. As a function modifier,
There are conductive and magnetic agents, antistatic agents (also called antistatic agents), and fluorescent whitening agents. Examples of the decomposition accelerator include decomposition methods such as biodegradation, photodecomposition, and thermal decomposition.

The second category includes powder modifiers, reaction modifiers,
There are interface modifiers and polymer modifiers. Powder modifiers include reinforcements / fillers, nucleating agents, processing aids, and powder / powder special structures. Reaction modifiers include crosslinkers, macromonomers, stabilizers (heat, light, radiation, organisms), and degradation promoters (biology, light, heat). Interface modifiers include coupling agents, compatibilizers, and plasticizers and solvents, or plasticizers or solvents. Examples of the polymer modifier include a processability improver and a performance modifier, a polymer alloy, and a blend (performance modification).

Details of these additives can be found in the revised and supplemented “Latest Pigment Handbook” (January 10, 1977, published by Seibundo Shinkosha Co., Ltd.) and the 1994 edition of “New Chemical Index” (July 1993). 23, published by The Chemical Daily), 12394 Chemical Products (January 26, 1994, published by The Chemical Daily) and the Plastic Data Handbook (April 5, 1984,
Satisfies the required properties from formulation examples (additives) described in various documents such as "Industrial Research Council") and "Practical Plastics Glossary 3rd Edition" (published by Plastic Age). In addition, use detoxification reactions, etc., in combination with types, additives and other compounding agents, and study the resin composition so as not to adversely affect the photographic light-sensitive material (physical failure such as photographic properties and blocking). By doing so, most of the compounding agents can be used for the injection molded article for photographic light-sensitive materials of the present invention. Note that the present invention is not limited to the representative examples described above.

In the present invention, a colored regenerated resin other than colored carbon black or a non-colored regenerated resin may be used. Further, the molding of the molding machine is not limited to injection molding, and vacuum molding, blow molding, extrusion molding, and the like can be used.

[0084]

As described in detail above, the present invention provides
A used resin part formed by injection molding of a thermoplastic resin is crushed, and the crushed crushed material or the crushed material is used for injection molding of a molded article again by an injection molding machine using the crushed material. Decomposition products generated from the gas are exhausted from the vent port and injection-molded, so that deterioration in photographic properties can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a film unit with a lens.

FIG. 2 is an exploded perspective view of a unit main body.

FIG. 3 is a flowchart showing the steps of a resource recycling production factory for a film unit with a lens.

FIG. 4 is a flowchart showing a procedure of recycling plastic parts.

FIG. 5 is an explanatory view schematically showing an injection molding machine.

FIG. 6 is a flowchart showing another embodiment of a procedure for recycling plastic parts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Film unit with a lens 19 Charging operation member 27 Strobe unit 28 Exposure unit 29 Front cover 31 Rear cover 33 Photo film 50 Injection molding machine 66 Vent port 67 Filter 68 Vacuum pump

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) B29C 45/63 B29C 45/63 // B29K 105: 26 B29K 105: 26 F term (reference) 4F206 AA50 AB06 AB18 AH73 JA07 JD03 JL02 JM01 JN05 JQ05 4F301 AA07 AA15 AB01 AD01 BC02 BC13 BF11 BF15 BF32

Claims (4)

[Claims] 1. A photographic photosensitive material for crushing a used resin part made of an injection molded article of a thermoplastic resin and injecting the crushed material at least as a part of a raw material and again performing injection molding to produce a recycled part. In a recycling manufacturing method for injection molded products, a molding machine equipped with a vent port in a heating cylinder is used to exhaust decomposition products, which are generated from the molten resin during injection molding and adversely affect the photographic properties of photographic photosensitive materials, and are used for injection molding. A method for recycling an injection-molded article for a photographic photosensitive material. 2. The injection molding for a photographic photosensitive material according to claim 1, wherein the crushed material is formed into resin pellets by extrusion molding, and the pelletized recycled resin pellets are used as injection molding at least as a part of raw materials. How to recycle products. 3. The method for recycling an injection molded article for a photographic photosensitive material according to claim 1, wherein the vent port is reduced in pressure to 130 Pa and injection molded. 4. The recycling of an injection molded article for a photographic photosensitive material according to claim 1, wherein at least carbon black and an antioxidant are added as additives before said injection molding. Production method.