JP2012071550A - Urethane foam for sticking gelled elastic body, gelled elastic body-stuck urethane foam, and method for producing the gelled elastic body-stuck urethane foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide urethane foam which enables a gelled elastic body that is prepared by adding a paraffinic oil to a styrene base polymer, to be firmly stuck to the urethane foam without using a solvent-based adhesive.SOLUTION: In the urethane foam for sticking the gelled elastic body, that is prepared by adding the paraffinic oil to the styrene base polymer, an EVA-based hot melt resin layer 2 is formed on the sticking surface of the urethane foam 3 and the gelled elastic body is stuck to the EVA-based hot melt resin layer 2.

Description

  The present invention relates to a technique for bonding a gel-like elastic body formed by adding oil to a styrenic base polymer to urethane foam.

  Conventionally, cushioning materials such as mattresses that are used in combination with a gel-like soft elastic body that is molded by adding paraffinic oil to a styrene base polymer and urethane foam are known. For example, a technique of joining a plurality of gel-like elastic bodies on a urethane foam with an adhesive in which a low-hardness elastomer resin is dissolved in a solvent so as to be spaced apart from each other (see, for example, Patent Document 1) .), And columnar gel elastic bodies are inserted into a plurality of through-holes provided in the main body made of urethane foam, and the surface elastic member and the back surface member are laminated on the upper and lower surfaces of the main body to prevent the gel elastic body from falling off. A technique (for example, refer to Patent Document 2) is known.

Japanese Patent No. 4221952 Japanese Unexamined Patent Publication No. 2006-223832

However, in the case of the technique of joining urethane foam and gel-like elastic body using a styrene solvent-soluble adhesive as in Patent Document 1, paraffinic oil is added to the styrene base polymer. When the gel-like elastic body and the urethane foam are bonded, there has been a problem that the adhesion failure easily occurs because the paraffinic oil of the gel-like elastic body bleeds with time. Further, when considering the working environment and the environment at the time of use, there has been a demand for using a solvent-free adhesive without using a solvent-based adhesive as a measure against VOC.
Further, in Patent Document 2, although it is not necessary to adhere the gel elastic body with an adhesive or the like, since the columnar gel elastic body is inserted into a plurality of through holes provided in the urethane foam, There has been a problem that the deformation of the elastic body is limited by the through hole, and it is difficult to obtain an appropriate cushioning property.

  Accordingly, the present invention provides a urethane foam that can be firmly bonded without using a solvent-based adhesive when a gel-like elastic body in which paraffinic oil is added to a styrene-based polymer is bonded to the urethane foam. The purpose is to do.

Therefore, the present inventors tried adhesion using a hot melt resin. About hot-melt resin, adhesiveness was evaluated about the thing of an olefin type, a urethane type, an ethylene-vinyl acetate copolymer (EVA) type, a polyamide type, and an ethylene-methacrylic acid copolymer (EMA), respectively.
As a result, the adhesiveness between the urethane foam and the hot melt resin in the heat laminating method was generally good in any kind of hot melt resin, but the adhesive property between the hot melt resin and the gel elastic body is EVA type. It has been found that only hot melt resins can provide good adhesion.
In addition, since the EVA resin is compatible with paraffinic oil, there is no problem of a decrease in adhesiveness due to bleeding.

  That is, in order to achieve the above object, the present invention provides an adhesive for urethane foam as a urethane foam for adhering a gel elastic body in which a paraffinic oil is added to a styrene base polymer. An EVA hot melt resin layer was formed on the surface portion.

Here, the means for forming the EVA-based hot melt resin layer on the adhesive surface portion of the urethane foam is arbitrary, and the hot melt resin is processed into a sheet shape such as a film, a non-woven fabric, or a thermal transfer film, and a heat laminating method or a frame. You may make it affix on urethane foam by the lamination method etc., and may apply hot-melt resin by a spray, a roll coater, etc.
However, in the coating method as described above, since the melted hot melt resin penetrates into the cells of the urethane foam, it is necessary to treat a large amount of the hot melt resin in order to ensure adhesion. This impairs the texture of the urethane foam and increases the cost. Therefore, it is preferable that the hot melt resin is processed into a sheet and bonded by a heat laminating method or a frame laminating method.
When an EVA hot melt resin layer is formed on a urethane foam by the frame laminating method, a two-layer sheet comprising an EVA hot melt resin layer and a resin layer that can be bonded to the urethane foam by the frame laminating method. If it is used, it becomes easy to carry out frame lamination on urethane foam.

  In addition, when the gel-like elastic body is bonded to the urethane foam via the EVA hot melt resin layer, if the adhesive surface of the gel-like elastic body is heated to 90 to 170 ° C. and bonded, the adhesiveness is improved. preferable.

  By forming an EVA-based hot-melt resin layer on the adhesive surface of the urethane foam and adhering the gel elastic body, the adhesive strength is equal to or higher than that when using a solvent-based adhesive. In addition, since no solvent-based adhesive is used, the working environment and the environment during use are improved.

It is sectional drawing which shows the basic composition of the urethane foam for gel-like elastic body adhesion | attachment which concerns on this invention. It is sectional drawing which shows the structure in the case of forming the hot-melt resin layer for gel-like elastic body adhesion | attachment in a urethane foam by interposing the resin layer which can be adhere | attached with a urethane foam by the frame lamination method.

  The urethane foam for adhering to a gel-like elastic body according to the present invention is a solvent for adhering a gel-like elastic body (hereinafter simply referred to as a gel-like elastic body) in which paraffinic oil is added to a styrene base polymer to a urethane foam. It is characterized by forming an EVA-based hot melt resin layer on the adhesive surface portion of the urethane foam without using an adhesive.

Here, as described above, in order to bond the gel-like elastic body and the urethane foam without using a solvent-based adhesive, bonding with a hot melt resin was tried. An olefin type, urethane type, EVA type, polyamide type, or EMA type hot melt resin was used, and an adhesive evaluation with a gel-like elastic body was performed in a laboratory.
As a result, it has been found that only the EVA hot melt resin can obtain good adhesion to the gel elastic body.

  In the present invention, the EVA hot melt resin having good adhesion to the gel-like elastic body may be an ordinary hot melt resin, specifically, Hirodine manufactured by Yashara Chemical Co., Ltd. 7514, 7560, 7571, 7573T, 7579, VE-300-2S manufactured by Tosero Co., Ltd. and the like.

The means for forming an EVA-based hot melt resin layer on the adhesive surface of the urethane foam is arbitrary, and the hot melt resin is processed into a sheet such as a film, non-woven fabric, thermal transfer film, etc. The hot melt resin may be applied with a coating hand gun, spray, roll coater or the like.
In the coating treatment method as described above, since the melted hot melt resin penetrates into the cells of the urethane foam, it is necessary to treat the hot melt resin in a large amount in order to ensure adhesion. As a result, the texture of the urethane foam is impaired and the cost is increased. Therefore, it is preferable that the EVA-based hot melt resin is processed into a sheet shape and bonded by a heat laminating method or a frame laminating method.
However, it has been found that some EVA hot melt resins having excellent adhesion to the gel elastic body cannot be bonded to the urethane foam by the frame laminating method.
In that case, as shown in FIG. 2, if a sheet made of two layers composed of an EVA hot melt resin layer 2b and a resin layer 2a that can be bonded to urethane foam by a frame laminating method is used, the frame laminate is formed on the urethane foam. It becomes possible to do.

Examples of the resin that can be bonded to the urethane foam by the frame laminating method include an olefin resin, an EVA resin to which an olefin resin wax (LLDPE) is added, a urethane resin, a polyamide resin, and the like.
In particular, EVA resins and olefin resins to which olefin resin wax (LLDPE) is added have excellent adhesion to urethane foam and adhesion to EVA hot melt resins that can adhere to gel-like elastic bodies. Therefore, the peel strength between the layers is sufficient, which is preferable.

  Here, as a method of forming a two-layered sheet composed of the resin layer 2a and the resin layer 2b, a coextrusion method (coextrusion by inflation, coextrusion by T-die) or a lamination method (extrusion lamination) Method, heat laminating method, adhesive laminating method) and the like.

  Then, the two-layered sheet composed of the resin layer 2a and the resin layer 2b is subjected to corona discharge treatment on the surface of the resin layer 2a facing the urethane foam 3 side as necessary, and is wet according to JIS K 6768. The index may be set to 46 dyn or more and bonded to the urethane foam 3 by a frame laminating method.

Such an EVA-based hot melt resin layer 2 preferably has a thickness of 30 to 150 μm. If it is less than 30 μm, sufficient adhesion strength between the gel elastic body and the urethane foam 3 is difficult to obtain, and if it exceeds 150 μm, it is difficult to follow the cushioning property of the urethane foam 3 and the cost tends to increase.
When a two-layered sheet comprising a hot melt resin layer 2b and a resin layer 2a that can be bonded to a urethane foam by a frame laminating method is used, the hot melt resin layer 2b is 10 to 100 μm, and a urethane by a frame laminating method. The resin layer 2a that can be bonded to the foam is preferably 20 to 100 μm, and the overall thickness is preferably 30 to 150 μm.

The urethane foam to which the gel-like elastic body is bonded is not particularly limited. However, if the hardness is 150 to 250 N (conforming to JIS K 6400-2 D method), it is most suitable for bedding and cushioning materials. is there.
Further, when the hot melt resin layer is formed by a frame laminating method, it is preferable to select a urethane foam having excellent frame laminating properties.

Here, as a method of adhering the gel elastic body to the urethane foam through the EVA hot melt resin layer of the present invention, for example, the gel elastic body is previously bonded with a hot plate, a far infrared heater, hot air, or the like. After the surface is heated, it is placed on the hot melt resin layer.
In this case, when the temperature of the adhesive surface is heated to 180 ° C. or higher, the gel-like elastic body is not preferable because the surface becomes sticky or the shape is difficult to maintain, resulting in poor productivity.
Therefore, in order to have good adhesiveness by heating the adhesive surface of the gel elastic body to about 90 to 170 ° C., if the softening temperature of the EVA hot melt resin is 40 to 70 ° C., The gel-like elastic body can be adhered while maintaining its shape, which is preferable.
In this case, if the surface temperature of the hot plate is 145 to 215 ° C. and the gel elastic body is placed there for 10 to 180 seconds, the temperature of the adhesive surface of the gel elastic body can be adjusted to a range of 90 to 170 ° C.

As the hot-melt resin, olefin-based, urethane-based, EVA-based, polyamide-based, and EMA-based resins shown in Table 1 were used, and adhesiveness evaluation with a gel-like elastic body was performed in a laboratory. The results are shown in Table 1.

In addition, as shown in FIG. 1, hot melt resins (1) to (8) are used in advance on a urethane foam 3 having a thickness of 25 mm, a length of 70 mm, and a width of 140 mm by thermal lamination or thermal transfer. Then, a hot melt resin layer 2 having a thickness of 100 μm was formed to obtain a laminate 1. A gel-like elastic body (not shown) heated for about 10 seconds was placed on the surface of each laminate 1 with a hot plate kept at a surface temperature of 185 ° C., and adhesion was confirmed after cooling. Similarly, the adhesiveness of the gel-like elastic body heated at a hot plate surface temperature of 155 ° C. for 30 seconds and 215 ° C. for 30 seconds and 180 seconds was also confirmed. The adhesive surface temperature of the heated gel-like elastic body was 83, 90, 130, and 162 ° C., respectively. A gel-like elastic body having a columnar shape with a height of 40 mm and a diameter of 50 mm was used.
When the gel-like elastic body was heated at a hot plate surface temperature of 215 ° C. for 300 seconds, the adhesive surface temperature of the gel-like elastic body was 173 ° C., and the surface was sticky.

In Table 1, the ◯ indicates that the adhesiveness is good, the Δ indicates that the gel-like elastic body is pulled to some extent, and the × indicates that it is easily peeled off.

〔Urethane foam〕
Hardness 190N (JIS K 6400-2 D method), density 25kg / m ³
[Gel elastic body]
Elastomer resin molded product in which paraffinic oil is added to styrene base polymer (type of hot melt resin)
Film type EVA hot melt resin (1): Yasuhara Chemical Co., Ltd., product name “Hirodyne 7514”
EVA hot melt resin (2): manufactured by Tosero Co., Ltd., product name “VE-300-2S”
Urethane hot melt resin (3): manufactured by Okura Kogyo Co., Ltd., product name “Silkron HM105”
Urethane hot melt resin (4): Okura Industry Co., Ltd., product name “Silkron ES85”
Olefin hot melt resin (5): manufactured by Tosero Co., Ltd., product name “QE-600”
・ Film type olefin hot melt resin for thermal transfer (6): Made by Matsumura Oil Co., Ltd., product name “morescoRAC-30”
EMA hot melt resin (7): Yashara Chemical Co., Ltd., product name “Hirodyne 7589R”
Nonwoven fabric type polyamide hot melt resin (8): manufactured by Daicel Chemical Industries, Ltd., product name “Daiamide Span 1000”

  As a result, in Table 1, the hot melt resin layer 2 was formed on the urethane foam 3 in the thermal laminating process in Experimental Examples 1 to 5 and 8 and in the thermal transfer in Experimental Examples 6 and 7, but the laminating properties with the urethane foam were respectively It was generally good (evaluation ○).

On the other hand, in the adhesiveness between the gel-like elastic body and the hot melt resin layer 2, it was confirmed that only the EVA hot melt resins (1) and (2) can provide good adhesiveness.
Moreover, adhesiveness was not obtained in the EMA type hot melt resin (7) having the same softening point as the EVA type hot melt resin (1).
Furthermore, even when the softening point of the hot melt resin was equal to or lower than the adhesive surface temperature of the gel-like elastic body, no adhesiveness was obtained with the hot melt resins (3) to (8).

  Even in the same EVA system, the EVA hot melt resin (2) to which an olefin resin wax having a high melting point is added is slightly inferior to the EVA hot melt resin (1) to which no EVA resin is added. It was a result. As a factor, the difference in wettability due to the resin affects the adhesion.

  In addition, it was confirmed that there is no problem with the EVA resin in terms of peeling by oil bleeding from the gel-like elastic body. Since the oil is paraffinic, if it is an olefin resin or EVA resin that is compatible with the oil, no interfacial peeling due to bleeding occurs.

  Next, as a result of examining the case of producing a laminate in which an EVA hot melt resin layer is formed on urethane foam by the frame laminating method, as a result of the EVA hot melt resin (2) subjected to corona discharge treatment. It was confirmed that the film made of EVA hot melt resin (1) not containing olefin resin wax (LLDPE) subjected to corona discharge treatment does not adhere to urethane foam.

Therefore, in order to enable mass production by a frame laminating method, as shown in FIG. 2, an EVA hot melt resin layer 2b that can be bonded to a gel-like elastic body and a resin layer 2a that can be bonded to urethane foam by a frame laminating method. A laminated body 1A was produced by laminating the two-layered films 2a and 2b made of the above to the urethane foam 3 by a frame laminating method. And the adhesiveness in the case where the adhesive surface temperature of a gel-like elastic body is 130 degreeC was evaluated by the method similar to the above-mentioned. The results are shown in Table 2.
In addition, the resin layers shown in Table 2 are used as the two-layered films 2a and 2b as the EVA hot melt resin (1) as the EVA hot melt resin and as a resin that can be bonded to the urethane foam by the frame laminating method. 2a (1)-(5) was used. At this time, except for Experimental Example 10, a thermal lamination method was used, and in Experimental Example 10, a two-layered film was formed by the extrusion lamination method with a layer thickness shown in Table 2.

At this time, the surface of the resin layer 2a facing the urethane foam 3 side is subjected to corona discharge treatment so that the wetting index according to JIS K 6768 is 46 dyn or more, and the double-layered film is laminated on the urethane foam 3 by the frame laminating method. .
And the adhesion evaluation of the gel-like elastic body with respect to EVA type hot-melt resin layer 2b of this laminated body 1A was performed.

  In Table 2, in the adhesion between the gel-like elastic body and the urethane foam, ◯ indicates that the adhesion is maintained even when the urethane foam material is damaged, and x indicates that the resin layer 2a and the EVA hot melt are maintained. It shows that it peels between the layers of the resin layer 2b.

[Resin layer 2a]
EVA system (1): manufactured by Tosero Co., Ltd., product name “VE-300-2S”
EVA system (2): Tatsuno Chemical Co., Ltd., product name “Midea”
Olefin (3): manufactured by Tosero Co., Ltd., product name “QE-600”
Olefin (4): Okamoto Co., Ltd., product name “Emasoft 3C”
Urethane (5): Okura Industrial Co., Ltd., product name “Silkron HM105”

  The results are as shown in Table 2. The frame laminating property was good in any of the experimental examples. Further, in Experimental Examples 9 and 11 in which the resin layer 2a is an EVA-based film and a bilayered film is formed by a thermal laminating method and in Experimental Example 10 that is formed by an extrusion laminating method, both are gel elastic bodies. It was confirmed that the adhesiveness was good and the adhesive could be adhered at a level equivalent to or higher than that using a solvent-based adhesive.

Moreover, in Experimental Examples 12 and 13 in which the resin layer 2a is an olefin type, good adhesion between the gel-like elastic body and the urethane foam was obtained.
In Experimental Example 14, peeling between the resin layer 2a and the EVA hot melt resin layer 2b was observed.

  From the above, the effectiveness of the present invention was confirmed.

  In addition, this invention is not limited to the above embodiments. What has substantially the same configuration as the matters described in the claims of the present invention and exhibits the same operational effects belongs to the technical scope of the present invention.

  Mattresses and cushions can be firmly bonded without the use of solvent-based adhesives and without oil bleed when adhering a gel-like elastic body to which a paraffinic oil is added to a styrene-based polymer and urethane foam. Widespread use of materials is expected.

DESCRIPTION OF SYMBOLS 1, 1A ... Laminated body, 2 ... Hot melt resin layer, 2a ... Resin layer which can adhere | attach with urethane foam by frame lamination method, 2b ... EVA type hot melt resin layer.

Claims (4)

A urethane foam for adhering a gel-like elastic body obtained by adding a paraffinic oil to a styrenic base polymer to a urethane foam. A urethane foam for adhering to a gel-like elastic body, wherein a coalescence (EVA) -based hot melt resin layer is formed. A resin layer that can be bonded to urethane foam by a frame laminating method is formed on the urethane foam side of the EVA hot melt resin layer, and the resin layer is bonded to urethane foam by a frame laminating method. Item 1. The urethane foam for bonding an elastic gel body according to Item 1. A gel-like elastic body in which oil is added to a styrene-based base polymer is heated and bonded to an adhesive surface portion of the urethane foam on which the EVA-based hot-melt resin layer according to claim 1 or 2 is formed. Urethane foam with a gel-like elastic body attached. The adhesive surface portion of the urethane foam on which the EVA hot melt resin layer according to claim 1 or 2 is formed by heating the adhesive surface of the gel elastic body to 90 to 170 ° C. A method for producing a urethane foam to which a gel-like elastic body is adhered, wherein the gel-like elastic body is adhered to the substrate.

Images