JP6969791B2 - Manufacturing method of urethane molded products for medical and cosmetology - Google Patents

Description

The present invention relates to a method for producing a urethane molded product, which is used for medical treatment and cosmetology and is suitable for a place where there is a risk of touching a human part.

Conventionally, many urethane molded products have been used as medical instruments, but some of them are used in places where there is a risk of touching human parts.
For example, there are CT scans and MRI pillows that come into contact with the neck, handle parts of various instruments that are held by hand, and chest pads for ultrasonic waves that come into contact with the skin.
Normally, the surface of these urethane molded products is covered with a film of sprayed urethane paint, which serves as a surface protective film for the inside of foamed urethane.
However, when the surface is examined, although the fiber layers are overlapped to form a certain thickness, there are insignificant fine pores, and it cannot be said that the water-stopping property is surely maintained.
Therefore, if water invades through the micropores, the urethane inside is formed of communicative bubbles, so that it permeates in a communicative manner, and the inside may have wettability. This wettability has a risk of infectious diseases due to the propagation of bacteria in medical applications, and has a risk of causing more serious adverse effects in blood infiltration and the like.
On the other hand, when this water-stopping property is required, if the molded product is formed of a closed-cell foam such as polyethylene, the water-stopping property can be ensured by the isolated bubbles. In many cases, the properties after curing are hard, lack flexibility, and tend to be unsuitable in places where contact with the above-mentioned human parts is unavoidable.
Medical urethane molded products used in places where there is a risk of contact with human parts have such problems.

Patent Document 1 describes a method for producing a composite molded product by joining a synthetic resin sheet to a foamed molded product, but the present invention is mainly for a closed cell type molded product that promotes foaming by steam heating. Therefore, it cannot be used where it comes into contact with human parts, and it has no purpose of stopping water.

Japanese Unexamined Patent Publication No. 3-27925

The present invention has been made in view of the above problems, and is premised on the use of flexible foamable urethane, and seeks a water-stopping property that can prevent water from entering the inside thereof. It is intended to be provided for use and beauty treatment.

The method for producing a urethane molded product for medical treatment and beauty treatment of the present invention is a main agent having open cells formed after curing, comfortable elasticity in contact with a person, and rigidity capable of supporting the posture of a person's part. After preparing a urethane stock solution consisting of two liquid components of the curing agent and a mold consisting of a cavity and a core in which the target molded product is molded into a female mold, a) prevent water from entering the inside. A urethane film having water-stopping properties, flexibility extending from the edge of the mold to the bottom of the mold, and unevenness forming the surface on the anti-slip surface is applied so as to cover the upper surface of the cavity and the core of the mold. The step of fixing the mold to the upholstered state, b) the step of preheating the mold in the range of 40 ° C to 80 ° C and sucking it with a vacuum suction machine to bring the urethane film into close contact with the bottom of the mold, and c). The steps of pouring the above two undiluted urethane solutions into the mold, promoting the foaming reaction of the urethane under heating, and then taking out the molded product after curing and curing, and d) the urethane film of the taken out molded product. It is characterized by performing a step of cutting and shaping the end of the joint surface.

In the method for manufacturing a urethane molded product for medical / cosmetic use according to claim 2, the urethane film is made into a transparent or translucent film between the steps a) and b) according to claim 1 and is placed on the back side. It is characterized by having undergone a step of forming a coating layer by using a coloring agent on a urethane stock solution.

The molded product obtained by the production method of the present invention is an open-cell foamed urethane, which cannot have water-stopping properties like closed cells, and its surface is formed of a film having a dense molecular structure based on urethane bonds. The homogeneous film body does not allow the ingress of moisture and has a water-stopping property superior to that of closed cells.
During molding, the inside of the mold is in a pressurized state in the process of foaming the urethane stock solution, the foam body in the foamed state and the film body are in a close contact state, and the flexibility is increased by preheating, further joining the two. Make it strong.
Such water-stopping eliminates concerns about bacterial growth and the like.

The urethane liquid used in the present invention has open cells formed after foaming and has appropriate elasticity, does not cause discomfort due to contact, gives a soft and comfortable feel, and at the same time ensures safety.

At the same time, since the urethane film has been subjected to processing such as grain processing and satin finish, it has anti-slip properties with fine irregularities engraved on it, and even when used for pillows, handles, etc., it does not slip. No deviation is caused.

If the urethane film is fixed in a stretched state so as to cover the cavity of the mold and the upper surface of the core, and the mold is preheated in the range of 40 ° C to 80 ° C and sucked by a vacuum suction machine, the film is originally flat. The body can be brought into close contact with the bottom of the curved mold without wrinkles, and the surface of the molded product can be uniformly stretched on the film without wrinkles.

According to the aspect of claim 2, the resistance of the transparent or translucent urethane film to ultraviolet rays is enhanced, and at the same time, separation, peeling, etc. between the paint layer and the urethane foam, and between the paint layer and the urethane film, etc. Does not cause.
If characters, marks, etc. are displayed on the inside of the film body, there is no wear even after long-term use, and reliable display for medical use is possible.

It is a schematic diagram of the urethane foam injection machine used in this invention. It is a schematic side view of the mold used in this invention. Schematic aspects showing each step of the present invention, (a) is a step of applying a primer, (b) is a step of placing a urethane film, (c) a step of vacuum suction, and (d) forming a paint layer. The process is shown. Schematic aspects showing each step of the present invention show (e) a step of injecting a urethane stock solution, (f) a urethane foaming step, and (g) a step of demolding. It is a schematic cross-sectional view which shows an example of the molded article obtained by the manufacturing method of this invention.

First, the urethane foam injection machine 10 which is a premise of the manufacturing method will be described. As shown in FIG. 1, the device is provided with two tanks, an A tank containing a urethane main agent and a B tank containing a curing agent, and liquid feeding pies 11 and 12 with valves are connected from both tanks. A mixing 13 that mixes both liquids is arranged ahead of the mixing head 14, and the mixing head 14 can be sent out to the molding die 20 described later by mixing with forced stirring.

Regarding the effervescent urethane stock solution G composed of the main agent and the curing agent, first, the urethane solution was made into effervescent urethane forming open cells, and the molded body 30 after the effervescent curing touched a human part. It shall have cushioning properties that do not sometimes give a feeling of resistance, while it shall have supportability of hardness that can withstand use as a pillow, handle, or the like.
Further, it is assumed that the generated gas has a softness so that it becomes an open cell instead of a closed cell during the foaming reaction by the two-component reaction.
The foaming ratio and the like of the urethane stock solution G are determined so as to have such a characteristic, and those cultivated 5 to 20 can be used.
There are two types of urethane stock solution G, a polyether type and a polyester type. A polyether type that suppresses the decomposition of water is desirable in order to improve the water blocking property, but polyester is preferably used in combination with a urethane film described later. The system can also be used.

As for the mold 20, as shown in FIG. 2, the cavity 21 and the core 22 are opened and closed via a hinge 27 to form concave grooves 23 and 24, and one of the molded products is molded and the concave groove 23 is formed in the cavity. And the same applies to the core on the opposite side. This combination of irregularities is arbitrary, and in pillows and the like, a convex shape may be formed on the core side.
A vacuum suction machine for vacuum suction is arranged at one end of both molds of the cavity 21 and the core 22, and suction holes 25 and 26 connected to the suction machine by a pipe are provided on the back surface of the cavity 21 and the core 22. Form each.
At this time, since the suction has a portion having a large dent or the like according to the curved surface of the bottom wall of the mold, if the location of the suction hole is set according to the portion, the suction can be performed without waste.

In the present invention, urethane films 31 and 32 are used, and the characteristics required for the urethane films 31 and 32 will be described.
The urethane films 31 and 32 used in the present invention have water-stopping properties as a film body that prevents water from entering the inside, flexibility that can extend from the peripheral edge to the bottom of the mold, and the surface is formed on a non-slip surface such as a satin finish. Unevenness is required.
Water-stopping means that this component is molded when water or body fluid, blood, etc. adheres in medical treatment, inspection, etc., or when moisture adheres to the surface of the molded product due to condensation of moisture under high humidity conditions. Performance that can prevent intrusion into the inside of the product. This is provided by the dense molecular structure of the urethane molecule and the water-stopping ability of the membrane having a uniform and constant thickness, for example, about 10 to 50 μm.

In terms of flexibility, in mold molding described later, the urethane films 31 and 32 of the film body are placed on the surface of the mold, the peripheral edge is fixed by a frame or the like, and then the bottom of the mold is sucked by vacuum. Since it is placed in close contact with the film, it shall have the flexibility to follow the stretching by vacuum suction. At the same time, when it comes into close contact with the bottom of the mold preheated to 40 to 80 ° C., it is plasticized by the heat, and the flat film is soft enough to be uniformly adapted along the curved surface.
A film having this condition is a product after molding, and the surface thereof, which will be described later, becomes a wrinkle-free and taut film body, and like the foam layer 35 inside, it causes discomfort when it touches a human part. It has the characteristics that do not allow it.

In the case of unevenness, for example, when used for pillows, handles, etc., when the neck of a person touches or is grasped by hand, if the surface is slippery, slippage or slippage may occur and danger may occur. It refers to the performance to prevent this slippage.
For example, it refers to a product in which a wrinkle pattern called wrinkle processing is carved, a product in which an uneven groove called a satin finish is squeezed, and a product in which fine unevenness is carved.

Once the foam injection machine 10 and the mold 20 are prepared, the primer solution can be applied to the peripheral edges of the concave grooves 23 and 24 of the mold 20 (see FIG. 3A). In the present invention, this primer liquid is for improving the adhesion and water stopping property of the mold joint portion of the molded product described later, and a liquid having high adhesiveness to the films 31 and 32 is selected. For example, a chloroprene rubber-based adhesive or the like can be mentioned. The primer solution is sprayed toward the peripheral edge of the mold groove (hatched portion in FIG. 2) with a gun, or is brushed to apply a coating layer to the peripheral edge of the groove to a width of about 3 to 10 mm. Form.

Next, as shown in FIG. 3B, the urethane film 31 covers the concave groove 23 of the cavity 21 to have a size with a certain width, and is placed on the joining plane, and the same applies to the core side. And. Then, in order to secure the tension of the film, the peripheral edge is fixed by the frame bodies 21a, 22a, etc. fitted in the groove.
At this time, since the urethane films 31 and 32 have irregularities such as satin finish on one side as described above, the urethane films 31 and 32 are placed so that the uneven surface is on the front side (the side in contact with the wall surface of the mold groove).
After fixing the film in a stretched shape with the frames 21a, 22a'and the like, the cavity 21 and the core are closed via the hinge 27 and fixed with a clamp.
At this time, both the cavities 21 and the core 22 molds are preheated in the temperature range of 40 to 80 ° C. The preheating is for increasing the softness of the urethane films 31 and 32 by utilizing the thermoplasticity of the urethane films 31 and 32.

After setting the urethane films 31 and 32 on the mold, suction from the vacuum suction machine is started as shown in FIG. 3 (c). Then, the air in the gap between the molding groove and the urethane films 31 and 32 was removed, and the urethane films 31 and 32 were gradually extended to the bottom of the molding groove and eventually adhered to the bottom of the concave grooves 23 and 24. It becomes a state.
Then, since the urethane films 31 and 32 are originally flat, wrinkles may occur in the film body due to the difference between the flat surface and the curved surface when the urethane films 31 and 32 are originally flat, but they are fixed to the frame bodies 21a and 22a as described above. The urethane films 31 and 32 stretched are stretched to the bottom side of the mold by a negative pressure by a vacuum suction machine. Then, when the mold is in close contact with the bottom, the mold is heated to 40 to 80 ° C., so that the film is plasticized by heat and the flat film is uniformly blended along the curved surface. The surface of 32 has a wrinkle-free finish along a curved surface.

At this time, when the urethane films 31 and 32 are used, the urethane film is vulnerable to ultraviolet rays and may lack weather resistance as it is. As a countermeasure against this, a combination of a transparent or translucent urethane film and a paint called a colorant (undiluting agent) for a urethane stock solution, which will be described later, can be adopted.
That is, a transparent or translucent film is selected as the urethane films 31 and 32, and the paint layers 33 and 34 are formed therein by using a colorant (depositant) for the two-component urethane stock solution. Since various colors can be selected for the dyeing agent, a favorite color is prepared, and for example, two kinds, three kinds or more of paints and pigments are mixed to prepare a desired color. As a result, since the colorant (undidding agent) for the two-component urethane stock solution has excellent weather resistance, the entire paint layer has weather resistance.
As shown in FIG. 3D, the prepared paint is sprayed on the surface of the transparent urethane film with a spray such as a gun to form the paint layers 33 and 34.
By using a moisturizer, it is possible to prepare a favorite color, and sometimes it is possible to express a designed pattern. Moreover, the adhesive has good compatibility with the foam layer 35 and does not cause deterioration such as separation and peeling.

Next, as shown in FIG. 4 (e), the urethane stock solution G in which the main agent and the curing agent are mixed is transferred from the foam injection machine 10 through the mixing head 14 to the mold recesses 23 and 24. It is thrown into the space S formed by.
Then, when the mold 20 is heated while maintaining the preheating of 40 to 80 ° C. and 15 to 30 minutes have passed, urethane foaming reaction occurs inside, and isocyanate and polyester or polyether react with each other. Since the foaming phenomenon accompanied by the generation of carbon dioxide is induced and the urethane stock solution G has sufficient softness, the foam does not become a closed cell but forms an open cell (see FIG. 4 (f)). At this time, the foam layer 35 formed with the increase in gas pressure gradually pushes the urethane films 31 and 32 covering the peripheral edge to the mold wall surface.

When the foaming reaction of the urethane is completed, as shown in FIG. 4 (g), the clamp 28 is released, the cavity 21 and the core 22 are opened, and the cured molded product 30 is taken out from the inside. After that, it promotes natural curing that is left as it is for about 24 hours, and then puts it in a heating furnace at 30 to 80 ° C. and allows it to stand for about 8 hours for heat curing to promote complete curing.

When the fully cured molded product 30 is obtained, the end portion 36, which is the boundary surface sandwiched between the cavity 21 and the core 22, has two urethane films arranged in the cavity 21 and the core 22 extending in a protruding state. , It is cut and shaped along the peripheral edge of the molded body 30 with a cutting machine or scissors.
Thus, as shown in FIG. 5, a urethane molded product for medical treatment and cosmetology, which is used in a place where a person's part is touched, which is the object of the present invention, can be obtained.

Next, the action and effect of the urethane molded product obtained by the production method of the present invention will be described.
The urethane stock solution used in the present invention is effervescent of open cells and cannot have water stopping property like closed cells.
However, the surface of the molded product of the present invention is formed of urethane films 31, 32, and the urethane film has a dense molecular structure based on a urethane bond as a chemical component thereof, which is a film having a certain thickness. Since it becomes a body, it is extremely water-stopping and does not allow the ingress of water.
In the urethane films 31 and 32, the inside of the mold is in a pressurized state in the process of foaming the urethane stock solution G at the time of molding, and the foam body and the film body in the foamed state are in a close contact state. Moreover, the film is stretched by stretching by vacuum suction, but it has some elasticity after the urethane is cured, and the foam layer 35 as the foam body and the urethane films 31, 32 as the film body are provided. Make the joint even stronger.
Further, at the boundary surface between the cavity 21 and the core 22, the two urethane films 31 and 32 arranged on both sides are bonded to each other, but when the mold is set, the peripheral portion of the groove between the cavity 21 and the core 22 is formed. By applying a primer solution having high adhesiveness to the urethane film, the adhesiveness of the urethane films 31 and 32 at the joint portion is enhanced.

The urethane stock solution G composed of the main agent and the curing agent used in the present invention reacts with the urethane having isocyanate as described above with the polyether-based and polyester-based components, and after foaming and curing, open cells are formed to provide appropriate elasticity. It will be prepared.
As a result, if it is a hard molded body, it is rugged and uncomfortable and dangerous when it comes into contact with a human part such as a pillow or a handle, but in the present invention, the sensation associated with this contact is unpleasant. It does not give a pleasant sensation, gives a soft and comfortable feel, and ensures safety.

At the same time, when it comes into contact with a human part, if it is slippery, it will slip or slip, which is dangerous.
However, in the present invention, the urethane films 31 and 32 are engraved with a leather grain pattern or a satin pattern called wrinkle processing, a film squeezed into an uneven groove called a satin finish, and fine irregularities are engraved. It has anti-slip properties.
As a result, even if it is used for a pillow, a handle, or the like, slippage or misalignment is not caused when a person's neck is touched or grasped by hand.
Moreover, in forming the uneven grooves 23 and 24, a considerable processing cost is required to perform the embossing on the mold 20, but if a ready-made urethane film having been subjected to a satin finish or the like is selected, The cost can be reduced, and the size of the unevenness can be freely selected each time.

Further, in the manufacturing method of the present invention, the flexibility of the urethane films 31 and 32 is increased by the preheating of the mold, and the urethane film is sucked by vacuum to make the urethane film the bottom of the concave grooves 23 and 24 of the mold 20. It is in close contact with the film, and then it is heated and foamed and cured by curing.
At that time, the urethane films 31 and 32 fixed and stretched on the frames 21a and 22a are stretched toward the bottom of the mold by negative pressure by the vacuum suction machine, and when they are in close contact with the bottom, they are heated to 40 to 80 ° C. It is plasticized by the heat of the mold, and the film fits along the curved surface of the bottom. Then, if the flat film is formed along a curved surface, the film body may be wrinkled, but the surface thereof can be finished without wrinkles.
Then, the foam-like foam layer 35 and the film-like urethanes 31 and 32 are in close contact with each other due to the pressure applied by the foaming of the urethane stock solution G, and the film-like urethanes 31 and 32 are in close contact with each other. The surface becomes taut and the finished product is beautiful.

Further, if the urethane films 31 and 32 are made of a transparent or translucent urethane film and a layer of a paint as a coating agent is formed therein, the resistance to ultraviolet rays is enhanced and the weather resistance is excellent. Become.
At the same time, since the adhesive has high compatibility with the foam layer 35, separation, peeling, etc. do not occur between the paint layers 33, 34 and the foam layer 35, and similarly, the paint layers 33, 34 and the urethane film do not occur. Even if it is between 31 and 32, it does not separate or peel off.
Since the color can be freely adjusted, it is possible to freely select the desired color or the color required for medical safety, and to freely insert designed patterns and characters.
Here, safety is prioritized in medical molded products, and there are cases where it is required to insert characters corresponding to cautionary notes. In this case, when the characters are displayed on the surface as in the past, they disappear due to wear or the like. However, according to the above aspect, characters, marks, etc. can be displayed on the inside of the film body, and even if it is used for a long period of time, there is no wear and reliable display is possible.

The molded product produced by the present invention is mainly intended for medical use, for example, as a breastplate member, but can also be applied to barber and cosmetology for the same purpose.

10 Urethane foam injection machine 11 Liquid feed pipe 12 Liquid feed pipe 13 Mixing 14 Mixing head 20 Mold 21 Cavity 21a Frame 22 Core 22a Frame 23 Concave groove 24 Concave groove 25 Suction hole 26 Suction hole 27 Hinge 28 Clamp 30 Molded body 31 Urethane film 32 Urethane film 33 Paint layer 34 Paint layer 35 Foam layer 36 End G Urethane stock solution

Claims (2)

A urethane stock solution consisting of a two-component component of a main agent and a curing agent, which forms open cells after curing and has firmness that can support comfortable elasticity and posture of a human part when in contact with a person, is prepared. After forming a mold consisting of a cavity and a core obtained by molding the target molded product into a female mold,
a) Urethane film with water-stopping properties that can prevent water from entering the inside, flexibility with extensibility that extends from the edge of the mold to the bottom of the mold, and unevenness that forms the surface on an anti-slip surface. In the step of fixing the peripheral edge in a stretched state with a frame so as to cover the cavity of the mold and the upper surface of the core.
b) The process of preheating the mold in the range of 40 ° C to 80 ° C and sucking it with a vacuum suction machine to bring the urethane film into close contact with the bottom of the mold.
c) The steps of putting the above two liquid urethane stock solutions into the mold, promoting the urethane foaming reaction under heating, and then taking out the molded product after curing and curing.
d) The process of cutting and shaping the end of the joint surface of the urethane film of the molded product taken out,
A method for manufacturing urethane molded products for medical and cosmetology, which is characterized by applying. Between the steps a) and b) according to claim 1, a step of making the urethane film a transparent or translucent film and forming a coating layer on the back side by using a coloring agent for a urethane stock solution was performed. A method for manufacturing urethane molded products for medical and beauty treatments, which is characterized by the above.

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