JP5728782B2 - Resin net containing silk component and its manufacturing method - Google Patents

Description

  The present invention relates to a resin net to be extruded, and particularly relates to a resin net containing a silk component and a method for producing the same.

Silk has a good touch and has a moist feel, and is used in various products that directly touch the skin.
For example, there are many products having a form in which silk yarn is knitted and a form in which silk powder is applied and adhered to the product surface. On the other hand, there are not many examples of products in which silk is directly mixed into a synthetic resin. If such products can be easily manufactured, it is considered that the use of silk can be further expanded.

As a technique for directly mixing silk with a synthetic resin, for example, a method of forming a composite material by melting and kneading a protein component such as silk into a synthetic resin is disclosed (for example, Patent Documents 1 and 2).
However, the obstacle to producing such a composite material is the heat resistance temperature of the protein component, and although this heat resistance temperature is around 100 ° C., the molding temperature of the synthetic resin reaches 200 ° C. or more. However, there is a problem that the protein is thermally decomposed during molding, resulting in a decrease in protein components, discoloration due to heat burn, and a decrease in strength.

In order to solve such a problem, Patent Document 1 adds an additive such as an antioxidant or a light stabilizer to a silk fibroin raw material pulverized into a fine powder to improve the heat resistance of the silk component. Proposals have been made.
Patent Document 2 proposes an invention in which a hydrolyzed sericin powder and a pellet-shaped resin are uniformly kneaded and melt-kneaded at a predetermined temperature to obtain a molded product.

Japanese Patent Laid-Open No. 8-113714 Japanese Patent Laid-Open No. 2005-234201

However, even when powdered silk and pellet-shaped resin are mixed, they cannot be uniformly kneaded due to the difference in specific gravity and particle size, respectively, thereby forming a mass of silk components in the resulting molded product, There was a problem that sufficient strength could not be obtained.
Naturally derived silk components (for example, sericin, fibroin, hereinafter referred to as silk components) and synthetic resins have no affinity in the first place. The mutual bond strength could not be further increased. As a result, it was thought that this low bonding strength would promote the thermal decomposition of silk, leading to a decrease in the silk component in the molded product, discoloration due to heat burn, and a decrease in strength.

  Furthermore, a general molded product is allowed to stand at room temperature or the like immediately after molding and is naturally cooled. This is a process necessary for removing the strain and stress generated in the molded product, but has a disadvantage that the thermal decomposition of the silk component proceeds in this process.

  The present invention has been proposed to solve such a conventional problem. In the stage before melting the synthetic resin, the aqueous solution in which the silk component is dissolved is uniformly attached to the resin. By performing cationization treatment, the adhesion amount of the silk component and the binding force between the silk component and the synthetic resin are increased, and then melted, extruded, and further cooled immediately after molding. An object is to provide a resin net and a manufacturing method thereof.

In order to achieve the above object, a resin net containing a silk component according to the present invention and a method for producing the same are a resin net and a method for producing the same which melt a pellet-like synthetic resin and are extruded from a die into a net shape. Then, an adhesion process in which a predetermined silk component extracted from silk is adhered to the pellet-shaped synthetic resin, a drying process in which the pellet-shaped synthetic resin to which the aqueous solution is adhered is dried, and extruded from the die. A cooling step of immersing the immediately following resin net in cooling water, and a resin net manufactured by this manufacturing method.
By having each of these steps, the present invention exhibits the following effects.

First, in the present invention, an adhesion process is provided in which an aqueous solution in which a predetermined silk component extracted from silk is adhered to a pellet-shaped synthetic resin.
In this way, the silk component of the aqueous solution is attached to the pellet-shaped synthetic resin because the adsorption of water is more effective when the liquefied silk component is attached than when it is attached as a powder. This is because the components are easily attached. Further, since the silk component is uniformly dissolved in the aqueous solution, the liquefied one can uniformly adhere the silk component to the pellet-shaped synthetic resin.

Next, the present invention includes a drying step of drying the pellet-shaped synthetic resin to which an aqueous solution is attached.
This is because by having the drying step in this manner, moisture in the aqueous solution is removed, and only the silk component can be attached to the pellet-shaped synthetic resin.

Furthermore, in this invention, it shall have the cooling process which immerses the resin net immediately after extruded from die | dye in cooling water.
This is because by having the cooling step in this way, thermal decomposition of the silk component can be suppressed rather than leaving at room temperature immediately after molding.

By such an action of each step according to the present invention, it is possible not only to attach the silk component evenly but also to increase the amount of the silk component attached, as compared with the case where the silk component is attached in powder form. Moreover, thermal decomposition can be suppressed by cooling immediately after molding.
In this way, by increasing the adhesion amount, equalizing the adhesion, and suppressing thermal decomposition, the thermal decomposition of the silk component by melt extrusion is inevitable, but the content of the silk component in the resin net is reliably increased. It can be made.

Furthermore, the adhesion process according to the present invention includes a cationization process for cationizing either a pellet-shaped resin or an aqueous solution, and an immersion process for immersing the pellet-shaped resin in the aqueous solution after the cationization process. It is as.
Thereby, this invention exhibits the following effects.

The adhesion process of the present invention includes a cationization process for cationizing either the pellet-shaped resin or the aqueous solution.
By having the cationization step in this way, the resin component and the silk component are bonded at the molecular level, so that it is possible to further increase the amount of adhesion and equalize the adhesion.

Furthermore, the adhesion process of the present invention includes an immersion process in which a pellet-shaped resin is immersed in the aqueous solution after the cationization process.
As a result, the contact area between the silk component and the pellet-shaped resin can be reliably increased, so that the silk component can be evenly adhered to the pellet-shaped resin, as well as the resin component after the cationization step. Since the binding reaction between the silk component and the silk component can be promoted, it is possible to further increase the amount of adhesion and equalize the adhesion.

  The resin net containing silk component produced through each of these processes contains a silk component more than conventional resin products, and is used especially in direct contact with the skin. Or it is most suitable as a net place for body washing nets, foaming nets for face washing, and the like, and it is made of a synthetic resin and can sufficiently exhibit silk characteristics such as smooth touch and moist feeling.

  According to the resin net containing a silk component of the present invention and the method for producing the same, the silk component is evenly and sufficiently adhered to the synthetic resin, and the bonding strength thereof is sufficiently increased and then melt-extruded. It is possible to provide a resin net that sufficiently suppresses the decrease in components, discoloration due to heat burn, and the decrease in strength, and sufficiently exhibits the characteristics of silk.

It is a flowchart which shows the manufacturing process of the resin net which concerns on this embodiment. It is the schematic of the molding machine which manufactures the resin net which concerns on this embodiment.

Hereinafter, preferred embodiments of a resin net containing a silk component and a method for producing the same according to the present invention will be described with reference to the drawings.
The resin net containing a silk component according to the present embodiment is a resin net that directly touches the skin, for example, a face washing or body washing net, a foaming net for face washing, and the like, compared to other synthetic resins. And a synthetic resin having a relatively low melting point (90 ° C. to 130 ° C.).
As shown in FIG. 1, this silk component-containing resin net has an adhesion step S1 in which an aqueous solution in which a silk component is dissolved is adhered to a pellet-shaped (granular solid) resin, and the pellet-shaped resin to which the aqueous solution is adhered is sufficiently dried. A drying step S2 for forming, a molding step S3 for forming a resin net by extruding from a die while melting the dried pellet-shaped resin, and a cooling step S4 for immersing the resin net immediately after being extruded in cooling water. It is a resin net molded by the manufacturing method. Hereinafter, each process is explained in full detail.

[Adhesion step S1]
The attaching step S1 is performed before the extrusion molding (melting), for uniformly attaching the silk component to a pellet-like resin (for example, a pellet blended with low density polyethylene and ethylene / vinyl acetate copolymer). In detail, in the preceding step, in detail, a process of attaching an aqueous solution in which a predetermined silk component extracted from silk by a predetermined heat treatment is adhered to a pellet-shaped resin is performed.
The aqueous solution attached to the pellet-like resin contains sericin and / or fibroin, which are silk components extracted from silk by a predetermined heat treatment.
This aqueous solution is prepared by, for example, putting naturally-derived silk such as silkworms and raw silk together with water into a high-pressure container such as a pressure cooker at a predetermined bath ratio (for example, silkworm: water = 1: 5 to 1: 100). Is obtained by heating at a predetermined temperature (for example, 100 ° C. to 130 ° C.) for about 1 to 2 hours, and is an aqueous solution containing a silk component according to the bath ratio.

In the attaching step S1, the aqueous solution thus obtained is directly attached to the pellet-shaped resin by spraying, coating, or the like. The pellet-shaped resin is added to the container filled with the aqueous solution. It is more preferable to throw in the bath ratio (aqueous solution: resin = 10 to 100: 1) and soak for a predetermined time (for example, 5 minutes to 2 hours) while stirring. This is because the silk component can be evenly attached to the pellet-shaped resin.
In particular, the silk component (for example, sericin) has high hydrophilicity and is uniformly dissolved in water. Therefore, by sufficiently immersing the pellet-shaped resin in such an aqueous solution, the pellet-shaped resin is obtained. On the other hand, the silk component is evenly attached.
In this dipping step, the container filled with the aqueous solution may be dipped while being heated at a predetermined temperature.

Furthermore, it is preferable to introduce a step of increasing the binding force between the silk component and the resin before the silk component is attached to the pellet-shaped resin.
Therefore, in this embodiment, in order to increase these bonding forces, there is a step of charging and bonding the pellet-shaped resin and the silk component to different charges.
Specifically, before the silk component is attached to the pellet-shaped resin, a cationization step of imparting cationicity to either the pellet-shaped resin or the aqueous solution is performed. Hereinafter, the cationization step will be described.

[Cationization step]
In the cationization step of the present embodiment, the pellet resin is imparted with a cationic property, and the pellet resin and a predetermined cationizing agent are reacted. For this reaction, it is sufficient to carry out a normal reaction in cationization such as immersion reaction, continuous reaction by pad / dry / cure, and cold batch reaction.
For example, in the case of cationization by an immersion reaction, a pellet-shaped resin is immersed in a treatment solution containing a cationizing agent at a concentration of 2 to 100 g / liter at a bath ratio of 1:10 to 200, and 40 to The reaction is carried out at a temperature in the range of 100 ° C. for 10-100 minutes. At this time, a catalyst such as an alkali can be used in combination depending on the type of the functional group. After the reaction, the pelletized resin is neutralized and washed.

By such a cationization step, the pellet-shaped resin has a cationic property. As a result, the anionic molecule of the silk component and the molecule of the cationic resin are bonded by ionic bonds, and as a result, the silk component can be uniformly and strongly attached to the pellet-shaped resin. . That is, by adding such a cationization step, not only the mutual binding force between the pellet-shaped resin and the silk component, but also the amount of the silk component attached is increased.
Various cationizing agents such as amine-based polymers and monomers having cationic properties can be used. For example, a quaternary ammonium salt compound can be used.

Moreover, in said embodiment, although cationic property was provided to pellet-shaped resin, cationic property can also be provided to the aqueous solution containing a silk component. For example, in order to cationize the aqueous solution by the immersion reaction, the aqueous solution can also be cationized by performing the same treatment as when the pellet-shaped resin is cationized.
Originally, polyethylene, which is a pellet-like resin of this embodiment, has the property of being easily charged negatively (anion), so that the cationized silk component is uniformly and strongly attached to the anionic pellet-like resin. Will do.

[Drying step S2]
The drying step S2 is a step of drying the pellet-shaped resin to which the aqueous solution (silk component) is attached. For example, the drying step S2 is dried at room temperature (25 ° C.) to 80 ° C. for 3 to 8 hours to remove moisture.
Thereby, only the condensed silk component adheres to the resin.

[Adding additives, etc.]
Following such drying process, before extrusion molding (melting), to improve the properties of the resin net into a dry pellet resin, heat stabilizer, plasticizer, lubricant, flame retardant, slip agent Etc. are blended with known additives.
For example, 50 kg of low density polyethylene and 50 kg of ethylene / vinyl acetate copolymer are blended with 3 kg of slip agent. At this time, 3 kg of high density polyethylene is also blended. These are uniformly mixed with the pellet-shaped resin by a stirrer.
The pelletized resin blended with the additive is subsequently melt extruded and cooled in the molding step S3 and the cooling step S4.
In the present embodiment, the molding step S3 and the cooling step S4 are performed by the resin net molding machine 1. Hereinafter, the resin net molding machine 1 that performs the molding step S3 and the cooling step S4 will be described with reference to FIG.

  As shown in FIG. 2, the resin net molding machine 1 includes a popper 10 that stores pellet-shaped resin, an extrusion unit 20 that extrudes the molded resin 20 toward the molding unit 20 while melting the pellet-shaped resin, and a die 31. The molding unit 30, the water tank 40 filled with the cooling water 41, and the roller 50 that winds up the resin net 100 are provided, and are stored in the hopper 10 by rotating the screw provided in the extrusion unit 20. The pelletized resin is supplied into the extrusion unit 20 and melted there, and is continuously extruded from the die 31 in the molding unit 30 by the extrusion pressure generated by the rotation of the screw, so that the cylindrical resin net 100 is obtained. It is comprised so that it may manufacture continuously. Molding process S3 of this embodiment is implemented by the extrusion part 20 and the shaping | molding part 30 of such a resin net molding machine 1. FIG.

[Molding step S3]
A cylinder surrounded by a heater and a screw are provided in the inside of the extrusion unit 20 and a pellet-shaped resin charged into the popper 10 is supplied to the cylinder by rotation of the screw, and the heater is stepwise. When heated by (for example, 180 ° C. to 250 ° C.), it is in a molten state and is pressed toward the forming portion 30 by an extrusion pressure due to rotation of the screw.
The molding part 30 is provided with a die 31 in which a groove part for discharging resin is formed and a motor 32 for rotationally driving the die 30, and the molten resin is extruded from the groove part by the extrusion pressure by the rotation of the screw. A net 100 is formed.
The die 31 is composed of a concentric cylindrical outer die and an inner die that are rotated in different directions by the motor 32, and the grooves formed on the sliding contact surfaces of each die are periodically overlapped and separated, A cylindrical resin net 100 having a rhombus mesh is continuously extruded from the groove.
This resin net 100 is exposed to room temperature immediately after extrusion. Since the resin net 100 of the present embodiment has a wire diameter of about 0.5 mm and has a net shape, it has good air permeability. Thus, exposure to room temperature immediately after extrusion in this way promotes cooling. The thermal decomposition of the silk component is suppressed.

[Cooling step S4]
The cooling step S <b> 4 is a step of cooling the resin net 100 immediately after being extruded from the die 31 by immersing it in the cooling water 41, and is performed in the water tank 40 installed at the lower part of the die 31.
The water tank 40 is filled with cooling water 41 having a predetermined temperature (for example, about 10 ° C. to 25 ° C.), and the resin net 100 immediately after being pushed out of the die 31 is passed through a roller installed at the bottom of the water tank 40. It is drawn into the water tank 40 and immersed in the cooling water 41.
Thereby, the resin net 100 is rapidly cooled and the thermal decomposition of the silk component is also stopped.
Thereafter, the resin net 100 is wound around the roller 50 and is commercialized through a process including a predetermined shearing process. The resin net 100 can be stretched at a predetermined stretch ratio by adjusting the extrusion speed of the resin net 100 and the winding speed of the roller 50 and the like.

As described above, the manufacturing method of the present embodiment allows the silk component to be uniformly attached to the pellet-shaped resin in the previous stage of melting the synthetic resin, and further, the cationization treatment is performed at the time of the attachment, thereby the silk component. Since the adhesion amount and the bonding force between the silk component and the synthetic resin are increased and then melted and extruded, the decrease in the silk component in the resin net 100, discoloration due to heat burn, and the decrease in strength can be suppressed.
Further, by immersing the resin net 100 immediately after being extruded from the die 31 in the cooling water 41 and cooling, the thermal decomposition of the silk component is suppressed, and the remaining amount of the silk component can be increased.

The resin net 100 according to the present invention manufactured by such a manufacturing method is commercialized as, for example, a face-washing or body-washing net, a face-washing foaming net, or the like that directly touches the skin.
In such a product, a continuous cylindrical resin net 100 sheared at a predetermined length is folded back in the longitudinal direction while maintaining the cylindrical shape, and the end is fixed (heat fusion) , Which is a product having a touch and moist feeling peculiar to silk.

  In addition, the conventional resin net when the silk component of the powder (silk powder) is directly mixed with the resin in the pellet form and extruded is heat-baked due to uneven adhesion between the resin and the silk component and insufficient bonding force. However, the resin net produced by the production method of the present invention no longer has such problems.

The presence or absence of the silk component in the resin net can be visually confirmed with a fluorescence microscope.
Since the silk component has the property of emitting fluorescence when irradiated with ultraviolet rays, when the resin net produced by the production method of the present invention is irradiated with ultraviolet rays, the silk component emitting fluorescence was confirmed.
Moreover, it has been confirmed that the content of the silk component can be adjusted by increasing or decreasing the extraction concentration of sericin and / or fibroin, which are silk components in the aqueous solution.

  The preferred embodiment of the silk component-containing resin net and the production method thereof according to the present invention has been described above, but the silk component-containing resin net and the production method thereof according to the present invention are not limited only to the above-described embodiment, It goes without saying that various modifications can be made within the scope of the present invention.

For example, in the present embodiment, the pellet-shaped resin is immersed in the aqueous solution in the attaching step, but the aqueous solution may be sprayed from above while stirring the pellet-shaped resin.
Further, before attaching the silk component to the pellet-shaped resin, as a step of increasing the binding force between the silk component and the resin, together with the cationization step or instead of the cationization step, a predetermined binder (for example, water-solubilized) is added to the aqueous solution. Acrylic acid ester, phenol resin, epoxy resin, urethane resin, etc.) can be mixed, and the pellet-shaped resin can be immersed therein.

Moreover, a silk component can also be added to the pellet-shaped resin after drying.
For example, when it is desired to increase (adjust) the silk component after attaching the silk component in the attaching step and removing moisture in the drying step, silk powder can be mixed into the pellet-shaped resin.
In this case, in order to achieve uniform adhesion of the silk powder to the pellet-shaped resin, instead of simply adding the silk powder to the pellet-shaped resin and stirring, a thickening polysaccharide (for example, alginic acid, It is preferable to add silk powder together with konjac paste or liquid paraffin and stir.
Since these are fluids having a predetermined viscosity, they are entangled with the pellet-shaped resin while the silk powder is taken into the inside, so that uniform adhesion is achieved.

  The present invention can be widely used when a silk component is melt-kneaded in a resin net.

DESCRIPTION OF SYMBOLS 1 Resin net molding machine 10 Popper 20 Extrusion part 30 Molding part 31 Die 40 Water tank 41 Cooling water 50 Roller S1 Adhesion process S2 Drying process S3 Molding process S4 Cooling process

Claims (2)

A method of manufacturing a resin net that melts pellet-shaped resin and extrudes from a die to form a net,
An adhesion step of attaching an aqueous solution in which a predetermined silk component extracted from silk is adhered to the pellet-shaped resin;
A drying step of drying the pellet-shaped resin to which the aqueous solution is attached;
And a cooling step of immersing the resin net immediately after being extruded from the die in cooling water. The attaching step includes
A cationization step of cationizing either the pellet-shaped resin or the aqueous solution;
The method for producing a resin net containing a silk component according to claim 1, further comprising an immersion step of immersing the pellet-shaped resin in the aqueous solution after the cationization step.

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