JP2006224617A - Polyurethane foam product and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyurethane foam product in which the surface part of a polyurethane foam core or its coating is covered with a film and is protected, the surface discontinuity of the coating hardly generates, the core surface part or the coating cannot separate easily at the time of demolding, and the surface of the product cannot be smudged and damaged easily after manufacturing. <P>SOLUTION: The manufacturing method comprises a skin formation process in which transparent films F1 and F2 made from TPU are made to be adsorbed by a molding surface 13 of a form block 10, a coating formation process in which a coloring coating material P of a polyurethane base is made to be applied inside of the film F2 and a coating 22 is formed, and a core formation process in which a polyurethane foaming raw material U is fed into to the cavity formed by the molding surface 13 and foamed to mold polyurethane foam core 21. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyurethane foam product having a polyurethane foam as a core and a method for producing the same.

As a method for producing a polyurethane foam product, a so-called mold coat molding method is known, in which a release material is sprayed on a molding surface of a mold, a colored paint is applied, and a polyurethane foam raw material is poured into the foam to foam. Patent Document 1).
JP 2004-323863 A

  However, in this mold coating method, there are cases where the surface of the coating film has uneven or uneven defects. This is presumably because the release agent does not necessarily adhere uniformly, and the colored paint comes into contact with the insufficient or excessive release agent. Also, the surface part or coating film of the polyurethane foam core adheres to the molding surface and is peeled off from the product at the time of mold release, or the core surface part or coating film is exposed to scratches after production, and the core or coating film absorbs water. There was also a problem that the surface of the product was easily soiled depending on the nature. In addition, there may be a problem that the coating film is peeled off during use of the product and the clothes are stained.

  Therefore, the present invention is a polyurethane foam core surface portion or its coating film is covered and protected by a film, surface defects of the coating film is difficult to occur, the core surface portion and the coating film are difficult to peel off at the time of mold release, It is an object of the present invention to provide a polyurethane foam product in which the product surface is hardly damaged and is not easily soiled.

In order to achieve the above object, the present invention adopts the following means.
(1) A skin forming step for adsorbing a transparent film on the molding surface of the mold, a coating film forming step for applying a colored paint to the inner surface of the film and drying to form a coating film, and the molding surface. And a core forming step of forming a polyurethane foam core by pouring a polyurethane foam raw material into the cavity to form a polyurethane foam core.

(2) The main part of the first heat-fusible film is adsorbed on the molding surface of the first mold and the peripheral part is brought into contact with the mating surface of the first mold, and the main part of the second heat-fusible film. The skin forming process in which the part is adsorbed on the molding surface of the second mold and the peripheral part is applied to the mating surface of the second mold, the first mold and the second mold are closed, and both films are placed between the mating surfaces of both molds. A core forming step of forming a polyurethane foam core by pouring a polyurethane foam raw material into a cavity formed between the molding surfaces of both molds and molding a polyurethane foam core, and at least one of the first mold and the second mold A skin fusion process in which the peripheral part of both films is heat-sealed at least at the peripheral part of the main part by a heating device provided in the vicinity of the mating surface, and the first mold and the second mold are opened, and the periphery of both films And a cutting process for cutting off the surplus part of the part Method for producing a single foam products. In the core forming step, either the closing of the first mold and the second mold or the pouring of the polyurethane foam raw material into the cavity may be performed first (hereinafter the same).

(3) The main part of the first heat-fusible film is adsorbed on the molding surface of the first mold and the peripheral part is brought into contact with the mating surface of the first mold, and the main part of the second heat-fusible film. A surface coating step of adsorbing the part to the molding surface of the second mold and applying the peripheral part to the mating surface of the second mold, and applying a colored paint to the inner surface of at least one of the first mold and the second mold The first and second molds are closed, and the periphery of both films is sandwiched between the mating surfaces of both molds, and between the molding surfaces of both molds. A core forming step for forming a polyurethane foam core by pouring a polyurethane foam raw material into the cavity to be formed, and a heating device provided in the vicinity of the mating surface of at least one of the first mold and the second mold, and the periphery of both films Heat at least at the peripheral part of the main part And a skin fusion step to wearing, and the first mold and the second mold and the mold is opened, producing a polyurethane foam product including the ablation process of excising the excess portion of the peripheral portions of the film. However, in the coating film forming step, a transparent film is used as the film to which the colored paint is applied.

  In the core forming step (1), an insert part is set in the mold in advance, and a polyurethane foam raw material is poured into a cavity formed between the insert part and the molding surface to form a polyurethane foam core. The polyurethane foam core and the insert part may be bonded together.

  The mold in each means includes a vacuum suction device for adsorbing the film to the molding surface, and the means (2) and (3) include the heating device. It is preferable to include a temperature control device for cutting out, a cutting-off device for the peripheral part of the heat fusion of the film, and the like.

(4) A polyurethane foam core, a colored coating film formed on a part or all of the surface of the polyurethane foam core, and a film provided so as to surround and cover the polyurethane foam core and the coating film all around. Polyurethane foam products consisting of an outer skin.

  In each of the above means, the material of the heat-fusible film is not particularly limited as long as it is heated and fused, and examples thereof include soft thermoplastic resins and thermoplastic elastomers. TPU (polyurethane thermoplastic elastomer) is preferable from the viewpoints of bondability, durability, elongation, and touch. The transparent film means not only a colorless and transparent film but also a colored transparent or translucent film, and any film can be used as long as the tip can be visually recognized through the watermark (the same applies hereinafter). Although the thickness of a film is not specifically limited, 30-100 micrometers is preferable. The film preferably has an elongation of 300 to 600% when preheated and vacuum formed.

  The colored paint is not particularly limited, and may be water-soluble or organic solvent-based, but is preferably a polyurethane-based paint (which may be two-component or one-component) from the viewpoint of bonding properties of other layers. Moreover, although the thickness of a coating film is not specifically limited, 5-50 micrometers is preferable and 5-10 micrometers is more preferable. The surface temperature of the film to which the colored paint is applied is preferably 40 to 50 ° C.

  The polyurethane foam foam raw material is not particularly limited, but is preferably a flexible foam or semi-rigid foam polyurethane raw material.

The use (specific product) of the polyurethane foam product of the present invention is not particularly limited, but it is preferably attached to equipment, devices and articles used in places where waterproofness is required or where dirt is easily attached. Some of them are listed below.
(1) Products with medical equipment: Cushion mats for operating tables, pillows for operating tables, arm pillows for injection tables, arm pillows for blood pressure / pulse measurement, backs, waist pads and special cushions for surgery (2 ) Barber equipment accessories: Barber chair cushions, hair wash pillows, etc. (3) Care products: bedding cushion mats, fracture contact pads, etc. (4) Toilet accessories products: toilet seat pads, etc. (5 ) Molded parts attached to furniture, chairs, tables, etc. for places where water and dirt are likely to be attached (kitchen, bathroom, around industrial machinery, etc.) (6) Products (7) Molded parts attached to farming tools (8) Molded parts attached to equipment used in cold regions (9) Protective products for sports: leggers, shoulder pads, knee pads, etc.

  According to the present invention, the surface portion of the polyurethane foam core or the coating film thereof is covered and protected by the film, surface defects are less likely to occur, the surface portion and the coating film are less likely to be peeled at the time of release, and after production An excellent effect is obtained that the surface of the product is less likely to be scratched and dirty.

  First, (1) in the skin forming step, the main part of the first TPU film F1 is adsorbed to the molding surface 43a of the first mold 41 and the peripheral part is brought into contact with the mating surface 44a of the first mold. The main part of the TPU film F2 is adsorbed on the molding surface 43b of the second mold, and the peripheral part is applied to the mating surface 44b of the second mold 42. Next, (2) in the coating film forming step, a polyurethane-based colored paint P is applied to the inner surface of at least one of the first mold 41 and the second mold 42 and dried to form the coating film 52. Next, (3) in the core forming step, the first mold 41 and the second mold 42 are closed, and the peripheral portions of the films F1 and F2 are sandwiched between the mating surfaces of both molds, A polyurethane foam core 51 is molded by pouring a polyurethane foam material into cavities formed between the 12 molding surfaces. Next, in the (4) skin fusion process, at least the peripheral portions of the films F1 and F2 are removed by the heating device 47 provided in the vicinity of at least one of the mating surfaces 44 of the first mold 41 and the second mold 42. Heat fusion is performed at the peripheral part of the main part. Finally, in the (5) excision step, the first mold 41 and the second mold 42 are opened, and surplus portions in the peripheral portions of both films F1 and F2 are excised.

  The mold 10 shown in FIG. 1a used in this embodiment is a mold having a split structure, and includes a first mold 11 serving as an upper mold and a second mold 12 serving as a lower mold. Both molds 11, 12 are provided with a molding surface 13 that forms the surface shape of the polyurethane foam product 20, and a cavity is formed by the molding surface 13 when the mold is closed. The first mold 11 has a flat plate shape and includes a flat molding surface 13a. On the other hand, the second mold 12 has a box shape with an open top surface, and includes a molding surface 13b that is recessed downward from the top surface. And the peripheral part of the molding surfaces 13a and 13b in both the molds 11 and 12 is the mating surfaces 14a and 14b, respectively.

  The mold 10 includes a vacuum suction device 15, a temperature control device 16, and a heating device 17. The vacuum suction device 15 is for vacuum-sucking and sucking the films F1 and F2 serving as the skin of the polyurethane foam product 20 to be molded on the molding surface 13, and has a large number of minute suction holes (opened in the molding surface 13). (Not shown) and a decompression pump (not shown) outside the mold communicated with this via a communication hole in the mold. The temperature control device 16 is for adjusting the mold temperature and also for adjusting the temperature of the adsorbed films F1 and F2. A temperature control pipe type or electric heater type for flowing a medium such as hot water or oil is used. It can be illustrated. The heating device 17 is for heat-sealing the peripheral portions of the films F1 and F2 at least at the peripheral portion of the main portion, and is provided in the vicinity of the mating surfaces of both the first mold 11 and the second mold 12. Yes.

  The molding method of the present invention for molding the polyurethane foam product 20 using the molding die 10 will be described below. The molding method includes a skin forming process in which transparent films F1 and F2 are attached to the mold 10, a coating film forming process in which a colored paint P is applied to the film F2, and a polyurethane foam raw material U is poured into the mold 10 and foamed. It includes a core forming step, a skin fusion step in which these films F1 and F2 are heat-sealed, and a cutting step in which the mold 10 is opened to cut off excess portions of the films F1 and F2. Details thereof will be sequentially described below.

(Skin formation process)
Here, an ultra-thin and transparent TPU film (manufactured by Okura Kogyo Co., Ltd .: trade name “Silkron / ES-85”) having heat fusion properties is used. As shown in FIG. 1 b, the first mold 11 is opened from the second mold 12, and the film F <b> 1 is placed along the molding surface 13 a of the first mold 11. Further, the film F2 is preheated by a preheating device (not shown) to increase the elongation rate, and then the main part of the film F2 is positioned so as to cover the concave molding surface 13b of the second mold 12, The peripheral portion is brought into contact with the mating surface 14 b of the second mold 12. Then, by vacuuming with the vacuum suction device 15, the main part of the film F2 is adsorbed to the molding surface 13b as shown in FIG. 1c to form a skin. At this time, the temperature of the molding surfaces 13 a and 13 b is kept at 40 to 50 ° C. by the temperature control device 16.

(Coating film formation process)
As shown in FIG. 2d, a polyurethane-based acrylic paint (mold coat) is sprayed onto the surface of the film F2 that has been vacuum-pressed and pressed on the second mold 12 as shown in FIG. A coating film 22 is formed and colored in an arbitrary color. The coloring may be applied to both sides, but in this embodiment, it is applied only to the film F2 which is the front side of the polyurethane foam product 20 to be molded.

(Core formation process)
After the coloring paint P is dried, as shown in FIG. 2e, after the polyurethane foam raw material U is poured into the cavity formed between the molding surfaces 13a and 13b of both the molds 11 and 12, the first mold 11 and the second mold 12 are used. The molds are closed, and the peripheral portions of both films F1 and F2 are sandwiched between the mating surfaces 14a and 14b of both molds 11 and 12, and the upper and lower surfaces are clamped and held. And the polyurethane foam core 21 used as the core of a product is shape | molded by foaming the polyurethane foam raw material U in the cavity of the shaping | molding die 10. FIG.

(Skin fusion process)
After completion of the reaction of the polyurethane foam raw material U in the mold 10, the heat fusion adhered to the molding surfaces 13a and 13b using the heating device 17 provided in the second mold 12 as shown in FIG. 2f. The films F1 and F2 are fused (weld setting). That is, the peripheral portions of the films F1 and F2 are heat-sealed by the heating device 17 provided in the vicinity of the mating surfaces 14a and 14b of the first mold 11 and the second mold 12 to thereby form the polyurethane foam core 21 and the coating. The membrane 22 is completely enclosed by both films F1, F2. In this way, a transparent skin 23 made of the films F1 and F2 is formed around the polyurethane foam core 21.

(Resection process)
After the molded product is extracted from the mold 10, the excess portions of both the films F1 and F2 are cut off. After the above steps, the polyurethane foam product 20 of the present invention shown in FIG. 2g is completed. The finished product shown in FIG. 2g is an upside down version from the state of FIG. 2f, and the upper side in FIG. 2g where the coating film 22 for coloring is present is the front side of the product.

  In the polyurethane foam product 20 of the example manufactured by the above method, the surface portion of the polyurethane foam core 21 and the coating film 22 thereof are completely enclosed by the films F1 and F2 (entirely in a cross-sectional view) and covered. It is an integrated product that is protected and protected. Therefore, since the coating film does not come into contact with the release agent as in the conventional mold coating method, the surface of the core 21 or the coating film 23 is peeled off at the time of mold release. It is difficult to obtain an effect that the surface of the product is difficult to be damaged and dirty after manufacture. The main effects including this effect are listed below.

[Ease of manufacturing]
(A) Facilitating uniform coating of molded products (b) Improving the degree of freedom of arbitrary colors and design of molded products (c) Facilitating the high-mix low-volume production of molded products by color [surface protection]
(D) Protection of colored coatings on molded products (prevents peeling, clothes stains, etc.)
(E) Increased surface strength of molded products (f) Protection of molded products for waterproofing (g) Prevention of surface contamination of molded products (h) Prevention of adsorption of molded product solutions (i) Maintaining cold resistance of colored coatings on molded products ( Prevention of low temperature cracking)

  In Example 1, the films F1 and F2 were attached to both sides of the polyurethane foam core 21. However, when the back side is not exposed, the film (that is, the film F2) is formed only on the front side of the product. And the film (that is, the film F1) may be omitted on the back surface. In this case, the above-described skin fusion process is not necessary.

  In this second embodiment, the same mold 10 as in the first embodiment is used, and the molding method is substantially the same as in the first embodiment, but the insert part I is set on the molding surface 13a of the first mold instead of the film F1. It is different in point. Therefore, the molding method of Example 2 includes the skin forming process, the coating film forming process, the core forming process, the skin fusion process, and the excision process, as in Example 1. . Details thereof will be described below with a focus on differences from the first embodiment.

(Skin formation process, coating film formation process)
The skin forming process and the coating film forming process are substantially the same as in Example 1, but as shown in FIG. 3A, the film F1 is not attached to the molding surface 13a of the first mold 11, and this example is used instead. The insert part I which becomes a part of the polyurethane foam product 30 to be molded in 2 is set. Therefore, the film F2 is attached to the second mold 12 in the same manner as in Example 1, and the colored paint P is applied thereon to form the coating film 32.

(Core formation process)
After the coloring paint P is dried, as shown in FIG. 3b, after the polyurethane foam raw material U is poured into the cavity formed between the insert part I and the molding surface, the first mold 11 and the second mold 12 Are closed, and the peripheral portion of the film F2 is sandwiched between the mating surfaces 14a and 14b of both molds 11 and 12. Thereafter, the polyurethane foam core 31 is formed by foaming the polyurethane foam foam raw material U. At the same time, the polyurethane foam core 31 and the insert part I are bonded together.

(Skin fusion process)
After completion of the reaction of the polyurethane foam raw material U in the mold 10, as shown in FIG. 3 c, using the heating device 17 provided in the second mold 12, the peripheral portion of the film F 2 in the vicinity of the mating surfaces 14 a and b Is fused to the insert part I, so that the polyurethane foam core 31 and the coating film 32 are entirely surrounded by the insert part I and the film F2. In this way, a transparent skin 33 made of the film F2 is formed.

(Resection process)
After the molded product is extracted from the mold 10, the surplus portion of the film F2 is cut off. After the above steps, the polyurethane foam product 30 of Example 2 including the insert part portion 34 shown in FIG. 3D is completed. The finished product shown in FIG. 3d is an upside down version from the state shown in FIG. 3c. The upper side in FIG. 3d with the coating film 22 is the front side of the product and the lower side with the insert part I is the back side. ing.

  Thus, by including an insert part or the like in the cavity in the molding process, a wide variety of polyurethane foam products including the insert part or the like can be molded. Further, when the insert part is included in the polyurethane foam product, it is not necessary to protect the portion covered with the insert part with the skin made of a film, so that it is possible to save the labor and material for that part. .

  The mold 40 shown in FIG. 4 used in the third embodiment is a split structure mold, and includes a first mold 41 serving as an upper mold and a second mold 42 serving as a lower mold. Both molds 41 and 42 are provided with a molding surface 43 to be a mold of the polyurethane foam product 50 of the third embodiment, and a cavity is formed by the molding surface 43 when the mold is closed. The first mold 41 and the second mold 42 are substantially the same as the second mold 12 of the first embodiment. Accordingly, each of the first mold 41 and the second mold 42 has a box shape in which the lower surface and the upper surface are opened, and includes molding surfaces 43a and 43b that are recessed upward from the lower surface and downward from the upper surface, respectively. . In addition, both molds 41 and 42 are provided with mating surfaces 44a and 44b, a vacuum suction device 45, a temperature control device 46, and a heating device 47 as in the second mold 12 of the first embodiment. .

  A molding method for molding the polyurethane foam product 50 using the molding die 40 will be described below. The molding method is substantially the same as the operation performed on the second mold of Example 1. Therefore, like Example 1, it is comprised including a skin formation process, a coating-film formation process, a core formation process, a skin fusion | fusion process, and a cutting process. Details thereof will be described below with a focus on differences from the first embodiment.

(Skin formation process, coating film formation process)
As shown in FIG. 4a, the first mold 41 of the mold 40 is opened from the second mold 42, and the films F1 and F2 are placed along the molding surfaces 43a and 43b of both the first mold 41 and the second mold 42, respectively. . Then, by vacuuming using the vacuum suction device 45, the films F1 and F2 are pressed against the molding surfaces 43a and b, respectively, and the peripheral portions are brought into contact with the mating surfaces 44a and b of the molding die 40. Then, the coating film 52 is formed by spraying the colored paint P on the inner surface of both films F1 and F2, and it colors in arbitrary colors.

(Core formation process)
After the coloring paint P is dried, as shown in FIG. 4B, after the polyurethane foam raw material U is poured into the cavity formed between the molding surfaces 43a and 42b of both molds 41 and 42, the first mold 41 and the second mold 42 are obtained. Are closed, and the peripheral portions of both films F1, F2 are sandwiched between the mating surfaces 44a, b of both molds 41, 42. Thereafter, the polyurethane foam foam raw material U is foamed to form the polyurethane foam core 51.

(Skin fusion process)
After the reaction of the polyurethane foam raw material U in the mold 40, as shown in FIG. 4c, the peripheral portions of the two films F1 and F2 are heat-sealed using a heating device 47 provided in the mold 40. Thus, the polyurethane foam core 51 and the coating film 52 are completely surrounded by both the films F1 and F2. In this way, a transparent skin 53 composed of the films F1 and F2 is formed.

(Resection process)
After the molded product is extracted from the mold 10, the excess portions of both the films F1 and F2 are cut off. After the above steps, the polyurethane foam product 50 of the present invention shown in FIG. 4d is completed.

  If the method as described above is used, both the first mold 41 and the second mold 42 are implemented even when the molding die 40 of the third embodiment having the concave molding surfaces 43a and 43b is used. A polyurethane foam product can be molded in substantially the same manner as the molding method of Example 1.

  In addition, this invention is not limited to the said Example, In the range which does not deviate from the meaning of invention, it can change suitably and can be actualized. For example, in Example 1, a double-sided polyurethane foam product may be formed by applying a mold coat to both the films F1 and F2. In Examples 1 to 3, a colored paint P is applied when coloring is not required. It does not have to be.

It is sectional drawing which shows the manufacturing method of the polyurethane foam product of Example 1 of this invention. It is sectional drawing which shows the process of the continuation of the molding method. It is sectional drawing which shows the manufacturing method of the polyurethane foam product of Example 2 of this invention. It is sectional drawing which shows the manufacturing method of the polyurethane foam product of Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mold 13 Molding surface 20 Polyurethane foam product 21 Polyurethane foam core 22 Coating film 23 Skin 41 First type 42 Second type 43 Molding surface U Polyurethane foam raw material P Colored paint F1 (First) Film F2 (Second) Film I Insert parts

Claims (5)

A skin forming process for adsorbing a transparent film on the molding surface of the mold,
A coating film forming step of forming a coating film by applying a colored paint on the inner surface of the film and drying;
And a core forming step of forming a polyurethane foam core by pouring and foaming a polyurethane foam raw material into a cavity formed on the molding surface. The main part of the first heat-fusible film is adsorbed on the molding surface of the first mold and the peripheral part is applied to the mating surface of the first mold, and the main part of the second heat-fusible film is A skin forming step of adsorbing to the molding surface of the two molds and applying the peripheral part to the mating surface of the second mold
The first mold and the second mold are closed, the peripheral portions of both films are sandwiched between the mating surfaces of both molds, and a polyurethane foam raw material is poured into a cavity formed between the molding surfaces of both molds to foam the polyurethane. A core forming step for forming a foam core;
A skin fusion process in which at least a peripheral part of both films is heat-sealed at a peripheral part of at least a main part by a heating device provided in the vicinity of at least one of the first mold and the second mold;
A method for producing a polyurethane foam product, comprising: opening a first mold and a second mold, and cutting a peripheral portion of both films. The main part of the first heat-fusible film is adsorbed on the molding surface of the first mold and the peripheral part is applied to the mating surface of the first mold, and the main part of the second heat-fusible film is A skin forming step of adsorbing to the molding surface of the two molds and applying the peripheral part to the mating surface of the second mold;
A coating film forming step of forming a coating film by applying a colored paint to the inner surface of at least one of the first mold and the second mold and drying;
The first mold and the second mold are closed, the peripheral portions of both films are sandwiched between the mating surfaces of both molds, and a polyurethane foam raw material is poured into a cavity formed between the molding surfaces of both molds to foam the polyurethane. A core forming step for forming a foam core;
A skin fusion process in which at least a peripheral part of both films is heat-sealed at a peripheral part of at least a main part by a heating device provided in the vicinity of at least one of the first mold and the second mold;
A method for producing a polyurethane foam product, comprising: opening a first mold and a second mold, and cutting a peripheral portion of both films.   In the core forming step, an insert part is set in the mold in advance, a polyurethane foam raw material is poured into a cavity formed between the insert part and the molding surface to form a polyurethane foam core, and at the same time, the polyurethane foam The method for producing a polyurethane foam product according to claim 1, wherein the core and the insert part are bonded.   A skin comprising a polyurethane foam core, a colored coating film formed on a part or all of the surface of the polyurethane foam core, and a film provided so as to surround and cover the entire polyurethane foam core and coating film Polyurethane foam products consisting of

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