JPH0689304B2 - Method for manufacturing foam-based adhesive member - Google Patents

Description

TECHNICAL FIELD The present invention relates to a foamed substrate-based pressure-sensitive adhesive member having a non-woven fabric-like porous structure made of a fibrous pressure-sensitive adhesive and having a breathable pressure-sensitive adhesive layer. Manufacturing method.

2. Description of the Related Art Conventionally, as a method for producing a foam substrate-based pressure-sensitive adhesive member, a method has been known in which a solution of a pressure sensitive adhesive is applied to a foam substrate and dried to form a pressure sensitive adhesive layer.

However, this method has a problem that it is difficult to form a breathable pressure-sensitive adhesive layer. The air-permeable pressure-sensitive adhesive layer is useful because its air passage can also function as a liquid flow passage. In particular, when the foamed base material is air permeable, air permeability is ensured even in the pressure-sensitive adhesive layer, which is extremely useful. However, in order to form a breathable pressure-sensitive adhesive layer by the above-mentioned conventional method, it is necessary to adopt a pattern coating method such as a dotted method, and it is difficult to repeatedly use the pattern mask due to the pressure-sensitive adhesive being attached. In addition, there was a problem that smooth ventilation was not obtained due to a large degree of deviation of the formed ventilation passages, and a problem of easy peeling due to a large degree of deviation of the bonded portion.

Means for Solving the Problems The present invention overcomes the above problems by using a fibrous pressure-sensitive adhesive body formed by molding a pressure-sensitive adhesive into a fibrous shape.

That is, the present invention is characterized in that a fibrous pressure-sensitive adhesive obtained by molding a pressure-sensitive adhesive into a fibrous form is spread on the surface of a foam substrate to form a pressure-sensitive adhesive having a non-woven fabric-like porous structure. The present invention provides a method for producing a foam substrate-based pressure-sensitive adhesive member.

Action By forming a pressure-sensitive adhesive into a fibrous form and spreading it on the surface of a foam substrate, a porous pressure-sensitive adhesive layer with a fibrous pressure-sensitive adhesive consisting of the formed product can be easily formed. To be done. The formed pressure-sensitive adhesive layer having a porous structure is excellent in adhesive force due to good ubiquity of adhesive contribution points based on the fibrous pressure-sensitive adhesive body. Further, it has good air permeability based on the voids. In particular, the pressure-sensitive adhesive layer formed in a non-woven fabric-like porous structure is excellent in the adhesive contribution point based on the fibrous pressure-sensitive adhesive on the surface, the even distribution of voids including the inside of the layer, and the void ratio. Large, there is little bias in the adhesive force of the foam substrate or its adhesive member to the adherend, and there is little bias in air permeability due to voids, and it is good not only in the thickness direction but also in the layer development direction and diagonal direction. It has breathability and is superior in adhesive strength and breathability.

In addition, if the surface of the foamed base material on which the fibrous pressure-sensitive adhesive is developed is porous, for example, if the foamed base material is air-permeable, the fibrous pressure-sensitive adhesive body enters the pores. As a result, the anchoring effect is increased and the pressure-sensitive adhesive layer is firmly held on the foam base material, and when the adhesive member is attached to the adherend and peeled off, adhesive residue remains on the adherend. It is difficult to use, and is suitable as a surface protection member such as a metal plate.

Examples of constituent elements of the invention As shown in FIG. 1, the production method of the present invention comprises developing a fibrous pressure-sensitive adhesive 21 on a foamed substrate 1 to form a nonwoven fabric-like porous structure pressure-sensitive adhesive 2. It is for obtaining a foam substrate-based pressure-sensitive adhesive member having

The foam substrate 1 may be, for example, a continuous foam having air permeability, an independent foam having no air permeability, a foam layer-attached body such as a laminate of foam, and the like. There is no particular limitation regarding the form, foamed structure, material and the like. The portion where the pressure sensitive adhesive 2 is provided may be on both sides or one side of the foam substrate 1 or a part thereof. When the pressure-sensitive adhesive layers 2 are provided on both sides of the foam substrate 1, the fibrous pressure-sensitive adhesive body 21 may be spread from both sides of the foam substrate 1, or may be spread on each side. The foamed base material 1 may be supplied and developed from one location or two or more locations while being rotated, and the development method is arbitrary. On the other hand, in the case where the pressure-sensitive adhesive layer 2 is partially provided on the foamed substrate 1, it is preferable that the fibrous pressure-sensitive adhesive body 21 is developed by masking unnecessary portions with an appropriate member. Of course, the fibrous pressure-sensitive adhesive body 21 may be partially developed without a mask, and any method may be adopted.

The fibrous pressure-sensitive adhesive 21 is formed, for example, by heating and melting the pressure-sensitive adhesive, and adding a solvent as necessary to form a liquid or fluid, which is one or more discharge holes. It can be performed by a method such as extrusion molding through a nozzle having a. The fibrous pressure-sensitive adhesive body 21 formed by this method is a single-layer structure having a cross-sectional shape corresponding to a nozzle shape. An example having a circular cross section is shown in FIG.

As illustrated in FIG. 3, in the present invention, the fibrous pressure-sensitive adhesive body is used.
The form of 21 may have a low adhesive strength or non-adhesive coating layer 23 on the outer side of the pressure-sensitive adhesive layer 22 corresponding to the fibrous pressure-sensitive adhesive having the single-layer structure. The coating layer 23 is formed of a pressure-sensitive adhesive having a low adhesive force, paraffin, plastic, or the like so as to be easily broken. Coating layer
The fibrous pressure-sensitive adhesive body 21 having 23 has a high adhesiveness or non-adhesiveness due to its low adhesive strength or non-adhesiveness. And the like can destroy the coating layer 23 and develop a sufficient adhesive force, and therefore are preferably used for forming the surface layer of the pressure-sensitive adhesive layer 2. Depending on the forming material, the thickness is preferably 0.01 to 30 μm, and more preferably 0.05 to 10 μm, rather than the coating layer 23 that can be easily broken by pressing by hand. A fibrous pressure-sensitive adhesive body having a coating layer 23
The formation of 21 is, for example, through a nozzle having double ejection holes, a method of extrusion molding while supplying a pressure-sensitive adhesive to the inner ejection holes and a coating layer forming agent to the outer ejection holes. It can be done by

The diameter and cross-sectional shape of the fibrous pressure-sensitive adhesive body 21 may be appropriately determined. Generally, it is 0.5 to 500 μm based on the outer diameter. As the fibrous pressure-sensitive adhesive body 21 used for forming the nonwoven fabric-like porous structure, an outer diameter of 0.5 to 100 μm is usually suitable.

The pressure-sensitive adhesive used to form the fibrous pressure-sensitive adhesive body 21 is not particularly limited. Any pressure sensitive adhesive such as acrylic pressure sensitive adhesive, rubber pressure sensitive adhesive, styrene / isoprene / styrene pressure sensitive adhesive, and silicone pressure sensitive adhesive may be used. A system in which additives such as a crosslinking agent and other fillers are mixed may be used.

The fibrous pressure-sensitive adhesive body 21 thus formed can be spread on the foamed base material 1 through, for example, a high-speed air stream from an air nozzle or the like. Alternatively, a method of extruding the fibrous pressure-sensitive adhesive as it is, or the like may be used, and other appropriate methods may be adopted. At the time of deployment, the deployment area may be expanded by, for example, rocking the discharge nozzle of the fibrous pressure-sensitive adhesive. In addition, when the pressure-sensitive adhesive layer of one kind of pressure-sensitive adhesive does not exhibit good adhesive strength to both the foam base material and the adherend, since it is adhered to a different adherend from the foam base material. The pressure-sensitive adhesive layer 2 is formed of two or more kinds of fibrous pressure-sensitive adhesive bodies 21 according to the purpose of use, and they are mixed, or a multi-layer structure of two or more layers is taken. Good.

The fibrous pressure-sensitive adhesive body 21 naturally develops into a porous structure by developing through a high-speed air flow with an air nozzle or the like, and if necessary, by forming a multi-layered structure with two or more layers as described above, a nonwoven fabric-like porous structure is obtained. The pressure sensitive adhesive layer 2 is formed. At that time, the fibrous pressure-sensitive adhesive body can be changed by changing the nozzle direction or the air velocity.
The unfolded state of 21 may be appropriately controlled to control the nonwoven fabric-like porous structure having a desired unfolded pattern.

The development pattern to the non-woven porous structure may be appropriately determined according to the purpose of use. The form, thickness, etc. of the nonwoven fabric-like porous structure in the pressure-sensitive adhesive layer 2 can also be controlled by repeating the expansion operation or combining appropriate expansion methods to laminate and expand the fibrous pressure-sensitive adhesive body 21. You can The laminated development method is advantageous when the pressure-sensitive adhesive layer 2 having a nonwoven fabric-like porous structure with a large porosity is formed using a thin fibrous pressure-sensitive adhesive body. It is also useful as a means for adjusting the thickness of the pressure sensitive adhesive layer 2.

The pressure-sensitive adhesive layer 2 having a non-woven fabric-like porous structure is particularly excellent in the adhesive contribution points based on the fibrous pressure-sensitive adhesive body 21 on the surface and the even distribution of void points including the inside of the layer, and the foamed substrate 1 Or, the adhesive force to the adherend is less biased, and the voids are also less biased, and the adhesive force and the air permeability are excellent. Furthermore, in addition to the thickness direction of the pressure-sensitive adhesive layer 2, the air permeability in the developing direction or the oblique direction is also excellent.

The thickness of the pressure sensitive adhesive layer 2 having a porous structure may be appropriately determined.
Generally, from the viewpoint of suppressing deformation when adhering to an adherend, the apparent thickness is 1 to 1000 μm, and especially 5 to 500 μm.
μm. The thickness of the pressure-sensitive adhesive layer 2 may be adjusted by forming a thicker spreading layer in advance and pressing it to make it thinner. In addition to adjusting the thickness, the pressing method uses a pressure-sensitive adhesive layer 2
It can also be used to adjust the porosity, the size of the void, the point of adhesion to the foam substrate 1 or the adherend, the adhesive force, and the like.

The porosity in the pressure-sensitive adhesive layer having a nonwoven fabric-like porous structure is 5 to
95% is general, 10-80% is especially preferable, and 30% or more is particularly preferable. The pressure-sensitive adhesive layer 2 having such a non-woven porous structure usually has a thickness of 5 to 200 μm at a rate of 5 to 400 g / m ² based on the weight of the fibrous pressure sensitive adhesive body 21 having a thickness of 0.5 to 100 μm. Can be formed by unfolding.

The foaming substrate-based pressure-sensitive adhesive member obtained by the method of the present invention, depending on the characteristics of the foaming substrate or the pressure-sensitive adhesive layer, for example, a packaging material,
It can be used for various purposes such as a masking material, a cushioning material, a heat insulating material, a surface protection member, a fixture, and a hook material, and the usage is not particularly limited. The exposed surface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive member is usually provided with a separator or the like for storage and distribution.

EFFECTS OF THE INVENTION According to the present invention, a fibrous pressure-sensitive adhesive is spread on the surface of a foam substrate to form a pressure-sensitive adhesive layer, so that a pressure-sensitive adhesive layer composed of a nonwoven fabric-like porous structure having an appropriate pattern can be easily formed. The pressure-sensitive adhesive layer can be formed and is excellent in uniform distribution of voids, has a large porosity, has little deviation in air permeability, and has air permeability also in the developing direction of the pressure-sensitive adhesive layer. In addition, the adhesive area consisting of a fibrous pressure-sensitive adhesive is excellent in uniform distribution and the bonding area is large, and the deviation of the adhesive force with respect to the foam base material or the adherend is small,
Excellent adhesion and breathability. In particular, when the foam base material is breathable, it maintains the breathability as a whole and is excellent in the adhesive force between the foam base material and the pressure-sensitive adhesive layer based on the anchoring effect.

Further, the present invention has an advantage that such a foamed substrate-based pressure-sensitive adhesive member can be efficiently obtained.

Example Example 1 A heated molten liquid of styrene / isoprene / styrene-based pressure-sensitive adhesive was provided on one side of a urethane-based foam base material having air permeability through an air nozzle having a discharge hole of 50 μm in diameter, and the nozzle was left and right. A fibrous pressure-sensitive adhesive body with an outer diameter of about 50 μm extruded while rocking 10 mm was sprayed and developed through a high-speed air flow to form a nonwoven fabric with an apparent thickness of about 80 μm and a basis weight of 32 g / m ² . A spreading layer is formed, and the spreading layer is pressed at a pressure of 1 kg / cm ² to attach a pressure-sensitive adhesive layer having a porosity of 65%, which is made of a nonwoven fabric-like porous structure having an apparent thickness of 70 μm, and is provided with breathability and A foam substrate-based pressure-sensitive adhesive member having good adhesive strength was obtained.

Example 2 A heating melt of an acrylic pressure-sensitive adhesive made of a butyl acrylate / acrylic acid copolymer and containing a polyisocyanate cross-linking agent on one side of a urethane-based foaming substrate having air permeability was prepared in accordance with the above. The fibrous pressure-sensitive adhesive body with an outer diameter of about 50 μm extruded by spraying is developed by high-speed air flow to form a non-woven development layer with an apparent thickness of about 70 μm and a basis weight of 24 g / m ^2. The expansion layer is pressed at a pressure of 1 kg / cm ^{2 and} a pressure sensitive adhesive layer with a porosity of 30% consisting of a non-woven porous structure with an apparent thickness of 40 μm is attached, and a foamed substrate with good breathability and adhesive strength is attached. A material-based adhesive member was obtained.

Example 3 A core made of the same acrylic pressure-sensitive adhesive as described above, extruded through a nozzle having double discharge holes onto the pressure-sensitive adhesive layer of the foam substrate-based pressure-sensitive adhesive member obtained in Example 2. A fibrous pressure-sensitive adhesive having an outer diameter of 50 μm having a coating layer of 5 μm in thickness made of a methyl methacrylate / ethyl acrylate copolymer was randomly spread on the outer periphery of the body, and the pressure-sensitive adhesive layer was laminated.

When the obtained foamed base material-based adhesive member was directly adhered to a stainless steel plate (SUS 304 BA finish) by a method of reciprocating a roller of 500 g, the adhesive force (180 peel,
The tensile speed was 300 mm / min,) was 16 g / 20 mm, and it showed good low tackiness. Next, the pressure-sensitive adhesive layer was pressed with a pressure of 5 kg / cm ² to break the coating layer in the fibrous pressure-sensitive adhesive body, and the adhesive force measured according to the above was 255 g / 20 mm.

The pressure-sensitive adhesive layer of the foamed substrate-based pressure-sensitive adhesive member of Example 2 was directly adhered to a stainless steel plate by a method of reciprocating a roller of 500 g, which was 300 g / 20 mm, 5 kg / cm. Adhesive force after pressing with a pressure of ² is 312 g / 20
It was mm.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a structural example of a foam substrate-based adhesive member, FIG. 2 is a perspective view of a structural example of a fibrous pressure-sensitive adhesive, and FIG. 3 is another fibrous feeling. It is a partial cross-sectional perspective view of the structural example of a pressure-bonded body. 1: Foamed substrate, 2: Pressure-sensitive adhesive layer, 21: Fibrous pressure-sensitive adhesive body, 22:
Pressure-sensitive adhesive layer, 23: coating layer

Claims (2)

[Claims] 1. A fibrous pressure-sensitive adhesive body obtained by molding a pressure-sensitive adhesive into a fibrous shape is spread on the surface of a foamed base material to form a pressure-sensitive adhesive layer having a non-woven fabric-like porous structure. A method for producing a foam substrate-based adhesive member. 2. The manufacturing method according to claim 1, wherein the foaming base material is permeable.