JP3470302B2 - Polyurethane film for covering foam and laminated sheet using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention, for example as in the mats of the seat and bedding of automobiles, synthetic resin films foam Suitable skin material to produce the foamed molded product obtained by coating with a surface material and It relates to a laminated sheet using the same.

[0002]

2. Description of the Related Art In order to cover the surface of a foamed molded product such as a synthetic resin used as a cushioning material for seats or bedding, conventionally, a foamed product having a predetermined shape is molded in a molding die. Separately, it was covered with a cut and sewn skin material, or after vacuum forming a skin material such as cloth into a predetermined shape, the foam material was foamed in the same mold.

However, according to the former method, the production of the skin material is complicated, and when the shape is complicated, the production is difficult and impractical. Although the latter method can manufacture a product having a complicated shape, defects are likely to occur depending on the manufacturing conditions, and once the defect occurs, the material cannot be regenerated, and the material including the expensive tension material is wasted. There is a drawback that

[0004] In this way, in the latter method, how to eliminate the poor, have I Do not the key to stabilize the production cost.
In the latter method, when using some of breathable fabric such as a skin material, and for vacuum forming a skin material into a predetermined shape in the mold, in the same mold, by foaming foam material In order to prevent the foamed material from being more stained than the skin material , the synthetic resin film is laminated on the skin material such as cloth , or the foamed synthetic resin laminated on the skin material to form a sheet.

For this synthetic resin film, since the foaming material to be foamed in the mold is usually polyurethane, a polyurethane film is generally used in consideration of adhesiveness.

[0006] As the polyurethane film, rich in flexible and resilient, yet in weak films with stiffness, the sliding property especially is wound up during the time of film production, or secondary processing, rewinding operations such as Greatly affects sex. Its <br/> for a method of mixing a lubricant wax component such as to improve slipperiness of the film during the film production in the material is used.

[0007]

However, the lubricant in the film stabilizes the foaming of the foaming material that foams in the mold .
Sei inhibit the action of foaming agent, at a portion close to the film surface, bubbles are not to uniform foaming takes place foam breaking, induces abnormal foaming so-called cell rough.

[0008] This tendency is remarkable as the percentage of lubricant contained in the film is high, also, if the proportion of lubricant is the same, the higher the heat applied to the film, also, the time from the manufactured The longer the time, the more prominent. This lubricant is considered to come exuded to the surface along with heating or aging.

The present invention can be applied to a film containing a lubricant,
An object of the present invention is to provide a synthetic resin film for covering a foam, which is improved so as not to cause cell roughness in a foam material formed by contacting it , and a laminated sheet using the same.

[0010]

In order to achieve the above-mentioned object, the present invention provides a polyurethane film for covering a foam, wherein the foamed polyurethane is brought into close contact with at least one surface thereof when the foamed urethane is foamed. To a lubricant containing a wax content of 0.15% by weight, and
It is characterized in that the surface in close contact with the polyurethane foam is subjected to corona discharge treatment with a weak electric power of 5 to 20 W per minute per square meter.

The present invention also relates to the above-mentioned foam-coated polyurethane.
A laminated sheet for foam coating , which is made by laminating a cloth on the surface of the retin film opposite to the surface that has been subjected to corona discharge treatment.
Also related to

[0012]

In polyurethane films and laminate sheets using the same the present invention, since the surface in intimate contact with the urethane foam is corona discharge treatment, lubricant contained within the film, to stabilize the Naruawa urethane foam The function of the foam stabilizer is not hindered, and it is possible to prevent the occurrence of cell roughness in the portion of the foamed urethane which is close to the film.

At present, how the inner surface of a polyurethane film containing a lubricant is subjected to corona discharge treatment to change the surface of the film, and why the effect of the lubricant is suppressed by doing so is at present. It has not been clearly elucidated, but is considered to be as follows.

(1) When corona discharge is applied to a weak layer on the film surface, electrons collide with each other, and the electron energy partially destroys the bond between elements to form an unstable molecule.

The unstable molecules are combined with oxygen decomposed by highly reducing ozone generated during corona discharge to complicate the molecular structure of the film surface, which causes the lubricant to be raised to the surface. It is held down.

(2) The film surface is electrically ionized by the collision of a large amount of electrons with the film surface.
Te, it assumed the bonding between the urethane foam and the film firm
Therefore, the effect of the lubricant is less likely to occur.

[0017] (3) by performing corona discharge, dissolved collision portion by the energy when the electron on the film surface has collided can minute depressions on the film surface, the physical change, and urethane foam Strengthens the bond with the film and makes it less likely to be affected by the lubricant.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5 show a manufacturing procedure of a seat portion (or backrest) of a chair using the first embodiment of the polyurethane film of the present invention in the order of steps.

In FIG. 1, (1) is a polyurethane film which is a thermoplastic synthetic resin film containing a lubricant.
It is a roll obtained by winding (2). As the lubricant, in order to facilitate handling of the post-stamping and molding the fine small amount 0.15
Weight percent wax is used. Too little wax
If, Tsu a poor slip properties of the polyurethane film (2)
Therefore , the handling becomes inconvenient, and if the amount is too large , the cell roughness increases.

[0020] The polyurethane film (2), discussed later be issued
Good adhesion with foamed polyurethane (13) .

[0021] (3) is electrically grounded dielectric roller, (4), in close proximity to the dielectric roller (3), and Ru electrode der disposed Te insulated <br/> . This electrode (4) and dielectric roller
A high frequency and high voltage are applied between (3) and the high frequency oscillator (5), and the air between them is dielectrically broken down and ionized to generate corona discharge. During the corona discharge, the roll
(1) by passing the feeding polyurethane film (2) from, it <br/> is processing one surface of the polyurethane film (2).

In the case of such a film treatment by corona discharge, the biggest factor that determines the treatment effect is the unit area of the raw material and the processing power (active power) per time, but the polyurethane film (2) is processed. 5 to 20 W / m
It should be relatively low at ² / min . As will be described later, when the processing effect required here is expressed by a wetting index conventionally used as a value representing this type of processing effect, it may be a relatively small value of about 34 dyn / cm. This is because.

In this embodiment, the corona discharge treatment device (6) comprises a dielectric roller (3), an electrode (4) and a high frequency oscillator (5).
However, a known commercially available device may be used. In particular, it is preferable to use a thyristor type.

Applied voltage and frequency, polyurethane foil
Fine conditions and specific work procedures, such as feed rate of Irumu (2) is determined based on the material and the feed amount of the polyurethane film (2), for which, various information such as Experimental Example Since it is already known, detailed description thereof will be omitted.

Next, a polyurethane film (2) having a corona discharge treatment of appropriate strength on one surface thereof is thus formed.
As a skin material, as shown in FIG. 2, a corona discharge treated surface faces upward on a mold (7) for vacuum heat molding having a recess (8) of a desired shape formed on the upper surface. And cover
And crown, and further presses pressing frame (10) from its upper, die
The peripheral edge of (7) and the polyurethane film (2) are airtightly adhered.

In this state, the polyurethane film (2)
The hot air, while heating by the electric heater (not shown) other heating means, if the exhaust from the recess so as to communicate with the (8) mold drilled exhaust hole (7) (9), polyurethane The film (2) is, as shown in FIG. 3, a recess (8) of the mold (7).
It is formed shaped to closely the inner surface. The polyurethane film (2) may be molded only by a vacuum suction action or by pressing or other molding means without using heating means.

Next, removal presser frame (10), as shown in FIG. 3, in the molded polyurethane film (2) to the concave, soy-based foam unfoamed stock solution (11) a predetermined amount injected, When the upper lid (12) is used to close the opening surface and then foam is formed, as shown in FIG. 4, a foamed polyurethane (13) is formed in the recess of the polyurethane film (2).

[0028] at the time of molding of the foam, in the conventional method, due to the influence of lubricant wax component like contained in the synthetic resin film arm, rough cell occurs in a portion close to the synthetic resin film arm, foam and a skin Not only the adhesiveness with the synthetic resin film, which is a material, is deteriorated, but also the properties of the foam are deteriorated .

However, according to the present invention, on the surface of the polyurethane film (2) which is in contact with the foamed polyurethane (13) ,
Since the corona discharge treatment is performed in advance, the occurrence of cell roughness is suppressed, as is clear from the reason as described above as the action of the present invention and the experimental examples described later, and
The adhesiveness between the foam film (2) and the polyurethane foam (13) is improved, and a homogeneous product having good properties can be obtained.

Next, the upper lid (12) is removed and the foamed polyuret is used.
Mold (7) the polyurethane film (2) with the tongue (13)
And more release, as shown in FIG. 4, a surface other than the upper surface port
A foam molded article (14) covered with a skin material made of only the urethane film (2) is formed. In addition, polyure
The more lubricant contained in the tank film (2), the release is facilitated.

Then, as shown in FIG. 5, the periphery of the polyurethane film (2) is folded back inward to form a foamed molded product (1).
If the seat plate (15) is attached to the back surface (upper surface in FIG. 5) of 4) , the seat portion (or backrest) of the chair is formed.

6 and 7 show a second embodiment of the present invention. In the second embodiment, as shown in FIG. 6, the same polyurethane film (2) as in the first embodiment on the side not subjected to the corona discharge treatment has a highly stretchable cloth (21). The laminated sheet (22) obtained by laminating is used as a skin material, and the foamed polyurethane (13) is covered therewith.

To produce the laminated sheet (22), a polyuret is used.
On one surface of a tan film (2), was subjected to corona discharge treatment in the same manner as described above, it is preferable to laminate the fabric (21) on the other surface, after stacking the fabric (21) above, polyurethane film
Corona discharge treatment may be applied to the surface of (2) opposite to the cloth (21).

Laminated sheet (22) manufactured in this way
2 with the surface treated by the corona discharge facing upward.
7 and by carrying out the same work as described in the first embodiment below, as shown in FIG. 7, a skin material whose outer surface is a cloth (21) ( Laminated sheet (22))
To form a foamed molded article (23) covered with the. In this case, the inner surface of the laminated sheet (22) molded in a concave shape, when the foaming by injecting unfoamed stock solution of synthetic resin foam, by beforehand to corona discharge treatment an inner surface of the laminated sheet (22) As in the case of the first embodiment, the occurrence of cell roughness can be suppressed.

[0035] In the first embodiment Experimental Example, the amount of slip agent contained in the polyurethane film (2), 0.1%, 0.15% and 0.2%
(These are all weight ratios. The same applies to the following.) The strength of corona discharge treatment was changed for each, and the degree of cell roughness was compared .

Here, as a method for judging the strength of the corona discharge treatment, the wetting index according to JISK6768 "Wetness test method for polyethylene and polypropylene film" on the treated surface after treatment was used.

As a criterion for cell roughness, the cell roughness evaluation table shown in Table 1 which was originally created was used.

[Table 1]

The results are shown in FIG. From FIG. 8, when the amount of the lubricant is 0.15% or less, the wetting index is 34 dyn /
By performing the cm or more of the corona discharge treatment, it can be seen that the cell rough there is no cause sons.

The wetting index of 34 dyn / cm is
Wetting index for polyethylene printing is about 38 dy
Compared with n / cm and a wetting index of 37 to 38 dyn / cm for printing on a polypropylene film, it is clear that the corona discharge treatment is a relatively weak treatment. It is significant that such a weak treatment can effectively prevent cell roughness.

[0040]

According to the present invention, the polyurethane film surface of the skin material in intimate contact with the polyurethane foam, by a previously corona discharge treatment, a lubricant contained in the polyurethane film, the Naruawa at foaming of the blowing agent it is not possible to inhibit the action of integer foams stabilizing, it is possible to prevent or suppress the occurrence of roughness cell at a portion near the film surface, good optimal ones as a synthetic resin film for the foam coating To be

Further, since it contains a lubricant, it has good self-lubricating property, and the film can be formed independently, and the carrier sheet is peeled off at the time of use as in the case of sticking the carrier sheet on one side. It is possible to save time and labor and to manufacture at low cost.

A cloth is laminated on the surface of the polyurethane film opposite to the surface on which the corona discharge treatment is applied to form a laminated sheet, whereby the polyurethane foam is covered. The cloth can be exposed on the outer surface to give a high-class feeling (claim 2 ).

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a situation of corona discharge treatment of a polyurethane film in a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional front view showing a state before vacuum heat molding when a foam molded article for a seat portion of a chair is manufactured using the film of the first embodiment.

[3] Also, after the vacuum heating completion of molding is a longitudinal front view showing a situation when the foaming by injecting unfoamed stock.

FIG. 4 is likewise a vertical cross-sectional front view of a foamed molded product that is released after the completion of foaming.

FIG. 5 is likewise a vertical cross-sectional front view of a state in which the seat is completed as a seat portion.

FIG. 6 is an enlarged vertical sectional front view of a part of a laminated sheet used as a skin material in the second embodiment of the present invention.

FIG. 7 is a vertical cross-sectional front view of a foamed molded body completed using the laminated sheet of the second embodiment.

FIG. 8 is a diagram showing the relationship between the wetting index and the degree of cell roughness in the experimental results.

[Explanation of symbols]

(1) Roll (2) Polyurethane film (skin material) (3) Dielectric roller (4) Electrode (5) High frequency oscillator (6) Corona discharge treatment device (7) Mold (8) Recess (9) Exhaust hole (10) Holding frame (11) Unfoamed stock solution (12) Upper lid (13) Foamed polyurethane (14) Foamed molded body (15) Seat plate (21) Cloth (22) Laminated sheet (23) Foamed molded body

Front page continuation (51) Int.Cl. ⁷ identification code FI C08J 5/18 CFF C08J 5/18 CFF C08K 5/01 C08K 5/01 C08L 75/04 C08L 75/04 (72) Inventor Katsumi Kashihara Nagoya City 5-32 Sakae Naka-ku, Ozaki Light Chemical Co., Ltd. (72) Inventor, Masateru Iida 5-1-2, Sakae Naka-ku, Nagoya City, Ozaki Light Chemical Co., Ltd. (56) Reference JP-A-4-152113 (JP, A) JP-A-1-131227 (JP, A) JP-A-6-31748 (JP, A) JP-A-61-89146 (JP, A) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) C08J 3/00-5/24 B32B 1/00-35/00 C08L 1/00-101/16 B29C 39/00-39/44

Claims (2)

(57) [Claims] 1. A polyurethane film for covering a foam, wherein the foamed polyurethane is brought into close contact with at least one surface of the foamed urethane when the foamed urethane contains a lubricant containing a minute amount to 0.15% by weight of a wax component. A polyurethane film for foam covering, characterized in that the surface in close contact with the polyurethane foam is subjected to corona discharge treatment with a weak electric power of 5 to 20 W per minute per square meter. 2. A foam-covering laminated sheet obtained by laminating cloth on the surface of the polyurethane film for foam-covering according to claim 1 opposite to the surface on which the corona discharge treatment has been performed.