JP2019193993A - Polyurethane laminated sheet and adhesive sheet - Google Patents

Abstract

To provide a polyurethane laminated sheet that has both moisture permeability and non-water swellability, and to provide an adhesive sheet.SOLUTION: According to the present invention, there is provided a polyurethane laminated sheet including a first polyurethane layer made of a first polyurethane material and a second polyurethane layer made of a second polyurethane material. Here, the polyurethane laminated sheet is characterized in that the first polyurethane material has water swellability and the second polyurethane material does not have water swellability.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a polyurethane laminated sheet. The present invention also relates to an adhesive sheet using a polyurethane laminate sheet as a base material.

  Adhesive sheets having a function of permeating moisture that evaporates are routinely used in various fields as highly functional members. For example, adhesive sheets for medical or hygiene materials such as surgical dressing materials and wound protection tape used for application to human skin have high moisture permeability so that moisture generated by sweating from the skin can be evaporated to the outside. Required.

  In addition, such adhesive sheets for medical and hygiene materials can prevent the entry of water, bacteria, viruses, etc. from the outside, and are flexible and capable of following the curved surface and movement of the skin. Strength. In order to satisfy such properties, an elastomer film having high rubber elasticity such as polyurethane having excellent moisture permeability is used for the base material (support) of the adhesive sheet for medical or sanitary materials of this type. May be. Patent document 1 is mentioned as a prior art document regarding this kind of technique.

Japanese Patent Laid-Open No. 2002-361813

  However, polyurethane may have a property of swelling with water (water swellability). When polyurethane having water swellability is used as the base material of the pressure-sensitive adhesive sheet, when water comes into contact with the pressure-sensitive adhesive sheet, the base material swells with water, and the appearance of the pressure-sensitive adhesive sheet is impaired. There may be a disadvantage that the pressure-sensitive adhesive sheet is likely to peel off due to change. For this reason, the base material of the pressure-sensitive adhesive sheet is required to have a property that hardly causes water swelling. However, polyurethane that hardly swells in water generally tends to have poor moisture permeability, and it has been difficult to achieve both moisture permeability and suppression of water swelling in a polyurethane sheet.

  This invention is made | formed in view of this point, and it aims at providing the polyurethane laminated sheet which was excellent in moisture permeability and suppression of water swelling. Another object of the present invention is to provide a pressure-sensitive adhesive sheet having both excellent moisture permeability and suppression of water swelling.

According to the present invention, there is provided a polyurethane laminated sheet including a first polyurethane layer made of a first polyurethane material and a second polyurethane layer made of a second polyurethane material. Here, the first polyurethane material has water swellability, and the second polyurethane material does not have water swellability. According to such a configuration, the second polyurethane layer functions as a barrier layer against moisture. For this reason, the water | moisture content which penetrate | invaded from the outside by the side of the 2nd polyurethane layer cannot reach the 1st polyurethane layer easily. Moreover, since the second polyurethane layer itself is made of a polyurethane material that does not swell with water, it does not swell with water. For this reason, according to this structure, the polyurethane laminated sheet which cannot be swollen with water as a whole can be realized.
In general, a polyurethane sheet having water swellability tends to exhibit excellent moisture permeability. For this reason, the polyurethane laminated sheet including the first polyurethane layer made of a material having water swellability tends to exhibit high moisture permeability.
Therefore, the polyurethane laminate sheet including the first polyurethane layer and the second polyurethane layer can be hardly swelled with water while having excellent moisture permeability.

According to the polyurethane laminated sheet according to a preferred embodiment disclosed herein, the first polyurethane material has a moisture permeability of 3000 g / (m ² · 24 hours) or more at a thickness of 20 μm. When a material having high moisture permeability is used as the first polyurethane material, the moisture permeability of the first polyurethane layer is improved and the moisture permeability of the entire polyurethane laminated sheet tends to be improved.

According to the polyurethane laminated sheet according to another preferred embodiment disclosed herein, the moisture permeability of the second polyurethane material at a thickness of 20 μm is 2500 g / (m ² · 24 hours) or less. In general, a polyurethane sheet having low moisture permeability tends not to swell with water. Therefore, according to the configuration including the second polyurethane layer made of the second polyurethane material having such moisture permeability, a polyurethane laminated sheet with improved non-water swellability (that is, suppression of water swellability) is easily obtained.

According to the polyurethane laminated sheet according to another preferred aspect disclosed herein, the thickness D ₂ of the second polyurethane layer is 8μm or less. Since the second polyurethane layer is made of the second polyurethane material that does not have water swellability, the second polyurethane layer tends to be relatively inferior in moisture permeability to the first polyurethane layer. Therefore, according to the configuration including the second polyurethane layer having the thickness D _2, excessive reduction of the moisture permeability of the entire polyurethane laminate sheet can be suppressed.

According to the polyurethane laminated sheet according to another preferred aspect disclosed herein, the thickness D ₁ of the said first polyurethane layer is 10μm or more. According to the configuration including a first polyurethane layer having such thickness D _1, the mechanical strength is handling property polyurethane laminate sheet is easily obtained with improved and enhanced.

According to the polyurethane laminate sheet according to another preferred embodiment disclosed herein, D ₁ / D ₂ which is a ratio of the thickness D ₁ of the first polyurethane layer to the thickness D ₂ of the second polyurethane layer is 3 to 20 It is. According to the polyurethane laminated sheet having such a configuration, both moisture permeability and non-water swellability can be easily achieved.

  According to the present invention, a pressure-sensitive adhesive sheet comprising any of the polyurethane laminate sheets disclosed herein is provided. In a preferred embodiment, the pressure-sensitive adhesive sheet includes any polyurethane laminated sheet disclosed herein and a pressure-sensitive adhesive layer provided on the surface of the polyurethane laminated sheet on the first polyurethane layer side. According to the pressure-sensitive adhesive sheet having such a configuration, the second polyurethane layer made of the second polyurethane material having no water swellability is disposed at a position away from the pressure-sensitive adhesive layer, so that the pressure-sensitive adhesive sheet is attached to the adherend and used. In this embodiment, the second polyurethane layer functions as a barrier layer against contact with moisture from the outside, and can be a pressure-sensitive adhesive sheet that hardly swells with water. Moreover, since the adhesive sheet of this structure contains the polyurethane laminated sheet excellent in moisture permeability as a base material, it becomes easy to become the thing excellent in moisture permeability as a whole. Therefore, according to this configuration, an adhesive sheet that is excellent in moisture permeability and hardly swells in water can be realized.

  According to the pressure-sensitive adhesive sheet according to a preferred embodiment disclosed herein, the pressure-sensitive adhesive layer contains a hot-melt pressure-sensitive adhesive. The use of such an adhesive is preferable from the viewpoint of productivity and environmental load reduction. In addition, a pressure-sensitive adhesive sheet containing such a pressure-sensitive adhesive typically tends to be less irritating to the adherend in applications such as sticking to human skin as the adherend.

It is a typical sectional view showing the composition of the polyurethane lamination sheet concerning one embodiment. It is a typical sectional view showing the composition of the polyurethane lamination sheet concerning other one embodiment. It is typical sectional drawing which shows the structure of the adhesive sheet which concerns on one Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention are based on the teachings on the implementation of the invention described in the present specification and common general technical knowledge at the time of filing. Can be understood by those skilled in the art. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field. Further, in the following drawings, members / parts having the same action may be described with the same reference numerals, and overlapping descriptions may be omitted or simplified. In addition, the embodiments described in the drawings are schematically illustrated in order to clearly explain the present invention, and do not necessarily accurately represent the size and scale of a product actually provided.

<Configuration of polyurethane laminate sheet>
FIG. 1 is a cross-sectional view of a polyurethane laminated sheet 10 (hereinafter sometimes simply referred to as “laminated sheet 10”) according to a preferred embodiment of the present invention. As shown in FIG. 1, the laminated sheet 10 of the present embodiment is configured by laminating a first polyurethane layer 20 and a second polyurethane layer 30. The first polyurethane layer 20 constitutes one surface 12 of the laminated sheet 10, and the second polyurethane layer 30 constitutes the other surface 14 of the laminated sheet 10.

  Although not shown, the laminated sheet 10 disclosed herein has one or more other polyurethane layers in addition to the first polyurethane layer 20 and the second polyurethane layer 30 as long as the effects of the present invention are not significantly impaired. May be provided. In the aspect in which the other polyurethane layer is included, the position where the other polyurethane layer is disposed may be between the first polyurethane layer 20 and the second polyurethane layer 30 or in the second polyurethane layer 30. The first polyurethane layer 20 may be on the opposite side, the first polyurethane layer 20 may be on the opposite side of the second polyurethane layer 30, or two or more selected from any of the above positions. It may be a position. Such a laminated sheet including other polyurethane layers can be grasped as a polyurethane laminated sheet 10 having a multilayer structure of three or more layers.

  The first polyurethane layer and the second polyurethane layer included in the laminated sheet disclosed herein are both made of a polyurethane material. Further, when the laminated sheet disclosed herein includes the other polyurethane layer, the other polyurethane layer is also made of a polyurethane material. Hereinafter, a polyurethane that can be suitably used as a polyurethane material constituting the first polyurethane layer, the second polyurethane layer, or another polyurethane layer will be briefly described.

  As the polyurethane contained in the polyurethane layer disclosed herein, those having excellent water vapor permeability (hereinafter also referred to as “moisture permeability”) can be preferably employed. As such polyurethane, polyester polyurethane, polyether polyurethane and the like are preferably used. Of these, polyether polyurethane is preferably used from the viewpoint of moisture permeability and flexibility.

  Generally, a polyether polyurethane is obtained by reacting a polyol component and a polyisocyanate component. The polyol component constituting the polyether polyurethane disclosed herein preferably contains at least one polyether polyol having a polyoxyalkylene skeleton.

The polyether polyol having a polyoxyalkylene skeleton can be obtained by polymerizing at least one alkylene oxide such as ethylene oxide, propylene oxide, and butylene oxide. As the polyether polyol having a polyoxyalkylene skeleton, those having a molecular weight of 500 to 3000 are preferably used.
In the polyether polyurethane disclosed herein, as a polyol component, a polyether polyol having a polyoxyalkylene skeleton is added to another polyol such as polyoxytetramethylene glycol, butanediol, heptanediol, hexanediol, cyclohexanediethyl. A part of polyol such as methanol can be used.

  Conventionally known materials can be used as the polyisocyanate component constituting the polyether polyurethane. Examples thereof include aromatic, aliphatic and alicyclic diisocyanates, dimers and trimers of these diisocyanates. Aromatic, aliphatic, and alicyclic diisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate. 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4 -Diisocyanate, dicyclohexylmethane-4,4-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methyl Cyclohexane diisocyanate, m- tetramethylxylylene diisocyanate. Moreover, these dimers, trimers, and polyphenylmethane polyisocyanate are used. Examples of the trimer include isocyanurate type, burette type, and allophanate type, and can be used as appropriate. These polyisocyanates may be used alone or in combination of two or more.

  A chain extender can be further used in the polyether polyurethane disclosed herein. As the chain extender, conventionally known materials can be used, and examples thereof include diols such as ethylene glycol, propylene glycol, and butanediol, and diamines such as ethylenediamine, tolylenediamine, and isophoronediamine.

  For the polyether polyurethane disclosed herein, additives that are usually used in a film, for example, an ultraviolet absorber, an anti-aging agent, a filler, a pigment, a colorant, a flame retardant, an antistatic agent, etc., if necessary. Can be added. These additives are used in normal amounts depending on the type.

  The polyether polyurethane can be polymerized using, for example, a one-shot method or a prepolymer method. Moreover, even if it is bulk polymerization which does not use a solvent, you may superpose | polymerize in a solution for viscosity reduction. Hereinafter, the bulk polymerization will be specifically described. Polyol is added to the reaction vessel, and polyisocyanate is added to cause urethanization while adjusting the temperature to 50 to 80 ° C. and stirring. After adding a chain extender and reacting, the reaction product is transferred to a tray and held at 100 to 150 ° C. for 4 hours or longer to complete the reaction, whereby a bulky polyether polyurethane can be obtained. it can.

<First polyurethane layer>
Regarding the first polyurethane layer included in the laminated sheet disclosed herein, the polyurethane material constituting the first polyurethane layer is hereinafter referred to as a first polyurethane material. The 1st polyurethane layer indicated here consists of the 1st polyurethane material which has water swelling nature. Since the polyurethane material having water swellability tends to have excellent moisture permeability, the use of the first polyurethane material improves the moisture permeability of the first polyurethane layer, and thus improves the moisture permeability of the entire laminated sheet. Can be made.

  As used herein, “water swellability” refers to the property of swelling with water. In this specification, the presence or absence of water swellability is determined based on the results of the water swellability test shown below.

[Water swelling test]
A test piece (size 50 × 50 mm, thickness 44 μm) having a surface made of a material to be tested is prepared. In an environment of a temperature of 23 ° C. and a humidity of 50% RH, 3 drops of deionized water at a temperature of 23 ° C. are dropped on the surface of the above test piece using a Komagome pipette, and after 5 minutes, the moisture on the test piece is waste. Wipe off and observe visually from the side whether there is any change in the shape of the specimen immediately. As a result, when a change is observed in the shape of the test piece, it is determined that there is water swellability, and when no change is observed, it is determined that there is no water swellability. Note that the size and thickness of the test piece may not be exactly the same as those described above. For example, the length may be appropriately changed within the range of about 20 mm to 100 mm, the width of about 20 mm to 100 mm, and the thickness of about 10 μm to 1 mm. In the examples described later, test pieces having a size of 50 × 50 mm and a thickness of 44 μm were used.

  The water swelling property of the first polyurethane material can be controlled by controlling the water swelling property of the polyurethane contained in the first polyurethane material. Alternatively, when the first polyurethane material is a mixture containing two or more polyurethanes, the water swelling property of the first polyurethane material can be controlled by adjusting the mixing ratio of polyurethanes having different water swelling properties. The water swellability of the polyurethane can be controlled by adjusting the type and blending ratio of the monomer components. For example, control of water swellability in polyether polyurethane can be performed by adjusting the type and blending ratio of the polyol component.

  From the viewpoint of improving the moisture permeability (property that allows water vapor to permeate) of the entire polyurethane laminated sheet, it is preferable that the moisture permeability of the first polyurethane layer contained in the polyurethane laminated sheet is higher. In particular, as will be described later, in the case where the laminated sheet is used in the form of an adhesive sheet configured by providing an adhesive layer on the first polyurethane layer side of the laminated sheet, the first polyurethane layer is attached to the adherend. Since the first polyurethane layer is disposed at a relatively close position, the first polyurethane layer is required to have a property of suitably transmitting water vapor generated from an adherend such as human skin.

  In this specification, “moisture permeability” is a value measured under conditions of a temperature of 40 ° C., a relative humidity of 90% RH, and a measurement time of 24 hours in accordance with a moisture permeability test (cup method) of JIS Z0208. Point to. Specifically, it can measure by the method as described in the Example mentioned later.

The moisture permeability at a thickness of 20 μm of the first polyurethane material is usually suitably larger than 2000 g / (m ² · 24 hours), preferably 3000 g / (m ² · 24 hours) or more, more preferably 3500 g / (M ² · 24 hours) or more, more preferably 4000 g / (m ² · 24 hours) or more (for example, 4500 g / (m ² · 24 hours) or more). When the moisture permeability of the first polyurethane material is too smaller than the lower limit described above, the moisture permeability of the first polyurethane layer is lowered, and as a result, the moisture permeability of the entire laminated sheet tends to be low. The upper limit of the moisture permeability of the first polyurethane material is not particularly limited. From the viewpoint of improving both moisture permeability and mechanical strength of the laminated sheet, it is appropriate that the moisture permeability at a thickness of 20 μm of the first polyurethane material is usually less than 7000 g / (m ² · 24 hours). Yes, 6500g / ^(m 2 · 24 hours) may be less, 6000g / ^(m 2 · 24 hours) may be less, 5500g / ^(m 2 · 24 hours) may be less, 5200g / ^(m 2 · 24 hours) It may be the following.

The thickness D ₁ of the first polyurethane layer is not particularly limited. To improve the mechanical strength of the laminated sheet, from the viewpoint of improving the handling property, it is preferable that the thickness D ₁ is 10μm or more, more preferably 20μm or more, even more preferably at least 30 [mu] m (e.g., 35μm or more) . The upper limit of the thickness D ₁ is not particularly limited, but from the viewpoint of not excessively reducing the moisture permeability of the laminated sheet, the thickness D ₁ is usually suitably 100 μm or less, preferably 50 μm or less, more preferably 45 μm or less.

Total first rate thickness D ₁ of the polyurethane layer to the thickness of the laminated sheet, in order to ensure the moisture permeability of the entire laminate sheet is preferably 50% or more, more preferably 60% or more, more preferably 70% or more. In the embodiment laminated sheet formed of only the first polyurethane layer and the second polyurethane layer, the ratio of the thickness D ₁ of the first polyurethane layer to the total thickness of the laminated sheet is preferably 80% or more, more preferably 85% or more (for example, 88% or more). Further, from the viewpoint of improving the non-water-swellable layered sheet, a first percentage thickness D ₁ of the polyurethane layer to the total thickness of the laminated sheet is preferably 98% or less, more preferably 95% or less, More preferably, it is 92% or less.

  The first polyurethane layer may be a porous polyurethane layer or a non-porous polyurethane layer. From the viewpoint of improving mechanical strength, the first polyurethane layer is preferably a non-porous polyurethane layer. On the other hand, from the viewpoint of improving moisture permeability, the first polyurethane layer may be a porous polyurethane layer.

  In the case where a porous polyurethane layer is employed as the first polyurethane layer, the porous polyurethane layer preferably contains open cells. The size of the bubbles is not particularly limited, but is preferably 20 μm or more and 300 μm or less. The porous polyurethane layer can be produced by a wet film forming method.

<Second polyurethane layer>
Regarding the second polyurethane layer contained in the laminated sheet disclosed herein, the polyurethane material constituting the second polyurethane layer is hereinafter referred to as a second polyurethane material. The 2nd polyurethane layer indicated here consists of the 2nd polyurethane material which does not have water swellability. By using the second polyurethane material that does not have water swellability, the second polyurethane layer can function as a barrier layer against entry of water from the outside.

  The water swellability of the second polyurethane material can be controlled by controlling the water swellability of the polyurethane contained in the second polyurethane material, similarly to the first polyurethane material. Alternatively, when the second polyurethane material is a mixture containing two or more polyurethanes, the water swelling property of the second polyurethane material can be controlled by adjusting the mixing ratio of polyurethanes having different water swelling properties. The water swellability of the polyurethane can be controlled by adjusting the type and blending ratio of the monomer components. For example, control of water swellability in polyether polyurethane can be performed by adjusting the type and blending ratio of the polyol component. For example, a polyether polyurethane obtained using polyoxytetramethylene glycol, butanediol, polyethylene glycol, polypropylene glycol, or the like as the diol component and methanediphenylene diisocyanate as the isocyanate component can be appropriately selected in terms of blending type and blending amount. Depending on the selection, a polyurethane having low water swellability can be obtained. Alternatively, a polyester polyurethane obtained by further blending a dicarboxylic acid component such as adipic acid can have a low water swellability.

The moisture permeability of the second polyurethane material is not particularly limited as long as it does not have water swellability. The moisture permeability at a thickness of 20 μm of the second polyurethane material is usually suitably less than 3000 g / (m ² · 24 hours), preferably 2500 g / (m ² · 24 hours) or less, more preferably 2300 g. / (M ² · 24 hours) or less, more preferably 2100 g / (m ² · 24 hours) or less. When the moisture permeability of the second polyurethane material is too larger than the upper limit described above, the non-water swellability of the second polyurethane layer tends to be reduced. From the viewpoint of more suitably realizing the non-swelling property to water, the moisture permeability at a thickness of 20 μm of the second polyurethane material may be 2000 g / (m ² · 24 hours) or less, or 1500 g / (m ² · 24 hours) or less, 1000 g / (m ² · 24 hours) or less, 600 g / (m ² · 24 hours) or less, or 500 g / (m ² · 24 hours). ) It may be the following.

The lower limit of the moisture permeability of the second polyurethane material is not particularly limited. From the viewpoint of not excessively reducing the moisture permeability of the entire laminated sheet, it is appropriate that the moisture permeability at a thickness of 20 μm of the second polyurethane material is usually larger than 0 g / (m ² · 24 hours), preferably 100 g. / (M ² · 24 hours) or more, more preferably 300 g / (m ² · 24 hours) or more, and still more preferably 400 g / (m ² · 24 hours) or more. From the viewpoint of further improving the moisture permeability of the entire laminated sheet, the moisture permeability at a thickness of 20 μm of the second polyurethane material may be 700 g / (m ² · 24 hours) or more, or 1100 g / (m ² · 24 hours). ), 1600 g / (m ² · 24 hours) or more, or 1900 g / (m ² · 24 hours) or more.

The thickness D ₂ of the second polyurethane layer is not particularly limited. From the viewpoint of suppressing deterioration of moisture permeability of the entire laminate sheet, it is preferable that the thickness D ₂ is less than 10 [mu] m, more preferably 8μm or less, still more preferably 6μm or less (e.g., 5μm or less). The function as a barrier layer from the viewpoint of suitably work to water, it is preferable that the thickness D ₂ is 1μm or more, more preferably 2μm or more, more preferably 3μm or more.

The second fraction of the thickness D ₂ of the polyurethane layer to the total thickness of the laminated sheet, in order to ensure the moisture permeability of the entire laminate sheet is preferably 20% or less, more preferably 15% or less, more preferably 10% or less. Further, from the viewpoint of improving the non-water-swellable layered sheet, a second ratio of the thickness D ₂ of the polyurethane layer to the total thickness of the laminated sheet is preferably at least 2%, more preferably 5% or more, More preferably, it is 8% or more.

D ₁ / D ₂ , which is a ratio of the thickness D ₁ of the first polyurethane layer to the thickness D ₂ of the second polyurethane layer, is not particularly limited, but is usually suitably 2 or more, and the moisture permeability of the laminated sheet From the standpoint of ensuring, it is preferably 3 or more, more preferably 6 or more, and still more preferably 8 or more (for example, 9 or more). From the viewpoint of ensuring non-swelling property to water, D ₁ / D ₂ is preferably 20 or less, more preferably 15 or less, and even more preferably 12 or less (eg 11 or less).

  The second polyurethane layer may be a porous polyurethane layer or a non-porous polyurethane layer. From the viewpoint of improving mechanical strength, the second polyurethane layer is preferably a non-porous polyurethane layer. On the other hand, from the viewpoint of improving moisture permeability, the second polyurethane layer may be a porous polyurethane layer.

  When a porous polyurethane layer is employed as the second polyurethane layer, the porous polyurethane layer preferably contains open cells. The size of the bubbles is not particularly limited, but is preferably 20 μm or more and 300 μm or less.

<Polyurethane laminated sheet>
The polyurethane laminated sheet disclosed herein is, for example, a two-layer extrusion using a T-die extruder or an inflation die extruder after melting the polyurethane material constituting each of the first polyurethane layer and the second polyurethane layer. By doing so, it can be formed into a sheet shape. Alternatively, when a polyurethane laminated sheet having a multilayer structure of three or more layers including the first polyurethane layer, the second polyurethane layer, and another polyurethane layer is formed, after the polyurethane material constituting each layer is melted, the T die It can be formed into a sheet by extruding three or more layers using an extruder or the like.

  Alternatively, the polyurethane laminated sheet disclosed herein can be produced, for example, by laminating these using a polyurethane sheet made of a first polyurethane material and a polyurethane sheet made of a second polyurethane material. .

  The thickness of the laminated sheet (hereinafter also referred to as “total thickness”) is not particularly limited, but is preferably larger than 10 μm, more preferably 25 μm or more, and even more preferably 35 μm or more (from the viewpoint of mechanical strength and handleability). For example, 40 μm or more). The upper limit of the thickness of the laminated sheet is not particularly limited. From the viewpoint of ensuring that the moisture permeability is not excessively reduced and ensuring flexibility, the thickness of the laminated sheet is usually suitably 150 μm or less, preferably 100 μm or less, more preferably 60 μm or less (for example, 50 μm or less). In addition, the thickness (total thickness) of a lamination sheet here does not include the thickness of the support sheet mentioned later.

The moisture permeability of the laminated sheet is not particularly limited. For example, when the laminated sheet is used as a base material for a medical or sanitary material pressure-sensitive adhesive sheet, the moisture permeability of the laminated sheet is usually 1000 g / (m ² · 24 hours) or more. There is preferably at 2200g / ^(m 2 · 24 hours) or more, more preferably 2500g / ^(m 2 · 24 hours) or more, more preferably 3000g / ^(m 2 · 24 hours) or more (e.g., 4000g / (M ² · 24 hours) or more). Further, the moisture permeability of the laminated sheet is usually 7000 g / (m ² · 24 hours) or less, and 6500 g / (m ² · 24 hours) or less from the viewpoint of balancing with other properties such as non-water swellability. And more preferably 6000 g / (m ² · 24 hours) or less.

  The laminated sheet is preferably transparent or translucent. According to such a laminated sheet, in the pressure-sensitive adhesive sheet containing the laminated sheet as a base material, when the pressure-sensitive adhesive sheet is stuck to the adherend, the attachment site of the adherend can be visually confirmed from above the pressure-sensitive adhesive sheet. .

<Supporting sheet>
A supporting sheet can be provided on the surface of the laminated sheet for the purpose of supporting the laminated sheet. By using the carrier sheet, it is possible to improve the workability at the time of production of the pressure-sensitive adhesive sheet including the laminated sheet as a base material and the operability at the time of sticking. The carrier sheet is typically peeled off after the pressure-sensitive adhesive sheet has been attached to the adherend.

  FIG. 2 schematically shows the configuration of the polyurethane laminate sheet 10 provided with a carrier sheet. FIG. 3 schematically shows the configuration of the pressure-sensitive adhesive sheet 50 provided with a carrier sheet. In the embodiment shown in FIG. 2, the carrying sheet 40 is provided on the surface of the laminated sheet 10 on the second polyurethane layer 30 side. According to such a configuration, as shown in FIG. 3, in the pressure-sensitive adhesive sheet 50 configured by providing the pressure-sensitive adhesive layer 60 on the surface of the laminated sheet 10 on the first polyurethane layer 20 side, the pressure-sensitive adhesive sheet 50 is attached to the adherend. Then, the carrier sheet 40 can be peeled off from the pressure-sensitive adhesive sheet 50.

The carrier sheet is preferably one that can impart a high elastic modulus to the laminated sheet. For example, the modulus of 50% when stretched by a tensile test at normal temperature and normal humidity for carrying sheet may be preferably 2N / mm ² or more 200 N / mm ² or less, it is 8N / mm ² or more 50 N / mm ² or less Further preferred.

  The support sheet is preferably transparent or translucent. According to such a support sheet, when the pressure-sensitive adhesive sheet is affixed to the adherend, it is easy to visually confirm the attachment site of the adherend from above the pressure-sensitive adhesive sheet.

  The material which comprises a support sheet is not specifically limited. For example, a polyolefin-based resin can be preferably used as a material constituting the carrier sheet. As the polyolefin resin, various known or commonly used polyolefin resins can be used without particular limitation. For example, polyethylene such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), metallocene catalyst type linear low density polyethylene, polypropylene, ethylene-propylene copolymer, ethylene- A vinyl acetate copolymer etc. are mentioned. Among these, LDPE can be preferably used. Such polyolefin resin can be used individually by 1 type or in combination of 2 or more types as appropriate.

  The thickness of the carrier sheet is not particularly limited. The thickness of the support sheet is preferably 20 μm or more, more preferably 30 μm or more, and further preferably 40 μm or more from the viewpoint of suitably supporting the laminated sheet. From the viewpoint of ensuring the flexibility of the laminated sheet in the embodiment provided with the support sheet, the thickness of the support sheet is preferably 100 μm or less, more preferably 75 μm or less, and further preferably 60 μm or less.

<Adhesive layer>
The pressure-sensitive adhesive sheet 50 according to the embodiment shown in FIG. 3 includes a polyurethane laminate sheet 10, a support sheet 40, and a pressure-sensitive adhesive layer 60. The carrier sheet 40 is provided on the surface of the polyurethane laminate sheet 10 on the second polyurethane layer 30 side. The pressure-sensitive adhesive layer 60 is provided on the surface of the polyurethane laminated sheet 10 on the first polyurethane layer 20 side.

  In the pressure-sensitive adhesive sheet disclosed herein, the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is not particularly limited. Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesive, rubber-based pressure-sensitive adhesive, polyester-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, polyether-based pressure-sensitive adhesive, and silicone-based pressure-sensitive adhesive. Here, the rubber-based pressure-sensitive adhesive refers to a pressure-sensitive adhesive containing a rubber-based polymer as a base polymer. The same applies to other adhesives. In addition, in this specification, a base polymer refers to the main component (component with the highest compounding ratio) in a polymer component. The proportion of the base polymer in the polymer component contained in the pressure-sensitive adhesive disclosed herein is typically about 50% by weight or more on a solid content basis, and usually about 70% by weight or more is appropriate. It may be 90% by weight or more. The upper limit of the proportion of the base polymer is 100% by weight, and may be about 99% by weight or less, for example.

  In some embodiments, from the viewpoint of adhesive performance and cost, a rubber adhesive or an acrylic adhesive can be preferably employed as the adhesive.

(Rubber adhesive)
Examples of rubber adhesives include natural rubber polymers such as natural rubber and modified products thereof, isoprene rubber, chloroprene rubber, styrene-isoprene-styrene block copolymer (SIS), and styrene-butadiene-styrene block copolymer ( SBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), crystalline polyolefin-ethylene / butylene-crystalline polyolefin block copolymer (CEBC), and styrene-ethylene / butylene-crystalline polyolefin block copolymer Examples thereof include a pressure-sensitive adhesive containing one or more rubber-based polymers such as coalescence (SEBC) as a base polymer. As a suitable example of the rubber-based pressure-sensitive adhesive, a pressure-sensitive adhesive (SIS-based pressure-sensitive adhesive) having SIS as a base polymer is exemplified.

In addition to the rubber-based polymer as the base polymer, the rubber-based pressure-sensitive adhesive may contain, for example, a tackifier and a process oil as main components.
Examples of the tackifier include various rosin-based, terpene-based, hydrocarbon-based, epoxy-based, polyamide-based, elastomer-based, phenol-based, and ketone-based tackifier resins, one type alone or two types. The above can be used in appropriate combination. Although not particularly limited, the amount of tackifier added to 100 parts by weight of the base polymer may be, for example, about 50 to 200 parts by weight, and usually about 80 to 150 parts by weight is appropriate.
As the process oil, for example, general paraffinic, naphthenic, and aromatic process oils can be used singly or in appropriate combination of two or more. Although not particularly limited, the blend amount of the process oil with respect to 100 parts by weight of the base polymer may be, for example, about 50 to 200 parts by weight, and usually about 90 to 150 parts by weight is appropriate.

(Acrylic adhesive)
The acrylic pressure-sensitive adhesive is a pressure-sensitive adhesive containing an acrylic polymer as a base polymer. Here, the acrylic polymer refers to a polymer having as a main constituent monomer component a monomer having at least one (meth) acryloyl group in one molecule (hereinafter sometimes referred to as “acrylic monomer”). The main constituent monomer component refers to a component occupying 50% by weight or more of the total amount of monomer components constituting the acrylic polymer. 70% by weight or more (for example, 90% by weight or more) of the monomer component may be an acrylic monomer. In the present specification, the term “(meth) acryloyl group” means an acryloyl group and a methacryloyl group. Similarly, in the present specification, (meth) acrylate is meant to generically refer to acrylate and methacrylate.

  The acrylic polymer may be a random copolymer, a block copolymer, a graft copolymer, or the like when the monomer component constituting the polymer includes two or more monomers. Random copolymers and block copolymers are mentioned as preferred acrylic polymers from the viewpoint of ease of production and handleability. An acrylic polymer can be used individually by 1 type or in combination of 2 or more types.

In a preferred embodiment, the acrylic polymer includes an acrylic random copolymer synthesized from a monomer raw material containing an alkyl (meth) acrylate having an alkyl group as a main monomer. As the alkyl (meth) acrylate, an alkyl (meth) acrylate having a chain alkyl group having 1 to 20 carbon atoms at the ester terminal, that is, a C _1-20 alkyl (meth) acrylate can be preferably used. From the viewpoint of the storage elastic modulus of the pressure-sensitive adhesive, C _1-12 (eg, C _2-10 , typically C _4-8 ) alkyl (meth) acrylate is preferable. These can be used alone or in combination of two or more. Preferred alkyl (meth) acrylates include n-butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, and the like. Among these, it is preferable to use one or both of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA).

  The ratio of the main monomer in the total monomer components constituting the acrylic random copolymer is preferably about 60% by weight or more, more preferably about 80% by weight or more, and about 90% by weight or more. More preferably. The upper limit of the ratio of the main monomer in the total monomer components is not particularly limited, but is usually about 99% by weight or less (for example, about 98% by weight) from the viewpoint of facilitating adjustment of the adhesive properties (adhesive strength, cohesive strength, etc.). % Or less, typically about 95% by weight or less). The acrylic random copolymer may be obtained by polymerizing only the main monomer.

  The monomer raw material used for polymerizing the acrylic random copolymer may further contain a submonomer copolymerizable with the main monomer in addition to the main monomer for the purpose of adjusting the properties of the pressure-sensitive adhesive. A suitable example of such a submonomer is a monomer having a functional group (hereinafter also referred to as a functional group-containing monomer). The functional group-containing monomer can be added for the purpose of introducing a crosslinking point into the acrylic polymer and easily adjusting the properties (adhesive strength, cohesive strength, etc.) of the adhesive. Examples of the functional group-containing monomers include carboxy group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, amino group-containing monomers, epoxy group (glycidyl group) -containing monomers, alkoxy group-containing monomers, Examples include alkoxysilyl group-containing monomers. These can be used alone or in combination of two or more. A functional group-containing monomer having at least one of a carboxy group, a hydroxyl group and an epoxy group can be preferably employed because it is easy to introduce a crosslinking point into the acrylic polymer and to easily adjust the crosslinking density. Among these, preferred functional group-containing monomers include carboxy group-containing monomers and hydroxy group-containing monomers. Preferable examples of the carboxy group-containing monomer include acrylic acid and methacrylic acid. Preferable examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate.

  When the functional group-containing monomer as described above is used, the functional group-containing monomer (preferably a carboxy group-containing monomer) is approximately 1 to 10% by weight (for example, approximately 2%) in all monomer components for polymerizing the acrylic polymer. -8 wt%, typically about 3-7 wt%).

  The monomer raw material may contain a monomer other than the functional group-containing monomer as a secondary monomer, for example, for the purpose of increasing the cohesive strength of the acrylic polymer. Examples of such monomers include vinyl ester monomers such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene, substituted styrene (α-methylstyrene, and the like), vinyltoluene; cyclohexyl (meth) acrylate, and isobornyl. Cycloalkyl (meth) acrylates such as (meth) acrylate; aryl (meth) acrylate (eg phenyl (meth) acrylate), aryloxyalkyl (meth) acrylate (eg phenoxyethyl (meth) acrylate), arylalkyl (meth) acrylate Aromatic ring-containing (meth) acrylates such as benzyl (meth) acrylate; olefinic monomers such as ethylene, propylene, isoprene, butadiene and isobutylene; vinyl chloride, vinyl chloride Chlorine-containing monomers such as Den; methyl vinyl ether, vinyl ether monomers such as ethyl vinyl ether; and the like. These can be used alone or in combination of two or more. The amount of the sub-monomer other than the functional group-containing monomer is not particularly limited as long as it is appropriately selected depending on the purpose and application. For example, in the total monomer components for polymerizing the acrylic polymer, about 20% by weight or less ( For example, it is preferably about 2 to 20% by weight, typically about 3 to 10% by weight.

The method for synthesizing the acrylic polymer is not particularly limited, and conventionally known general polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, suspension polymerization and the like can be appropriately employed. The mode of polymerization is not particularly limited, and a conventionally known monomer supply method, polymerization conditions (temperature, time, pressure, etc.), and use components other than the monomer (polymerization initiator, surfactant, etc.) can be appropriately selected and carried out. it can. The weight average molecular weight of the acrylic random copolymer (Mw) of not particularly limited, can be, for example, 30 × ¹⁰ 4 ~100 × ¹⁰ about ^4.

  In another preferred embodiment, the acrylic polymer includes an acrylic block copolymer. The acrylic block copolymer may exhibit the properties of a thermoplastic polymer (typically a thermoplastic elastomer). Such a pressure-sensitive adhesive containing an acrylic block copolymer as a base polymer can be suitable for application in a hot melt format. It is preferable to use a hot melt pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer from the viewpoint of productivity and reduction of environmental load. From the viewpoint of reducing the melt viscosity and the like, an acrylic block copolymer having a linear structure is more advantageous than a star structure or a branched structure.

  Examples of the acrylic block copolymer include at least one acrylate block (hereinafter also referred to as Ac block) and at least one methacrylate block (hereinafter also referred to as MAc block) in one molecule. Can be preferably employed. The Ac block is a monomer unit derived from an alkyl acrylate with about 50% by weight or more, preferably about 75% by weight or more, of all monomer units constituting the Ac block. The MAc block is a monomer unit in which about 50% by weight or more, preferably about 75% by weight or more of all monomer units constituting the MAc block is derived from alkyl methacrylate.

Examples of the alkyl acrylate constituting the Ac block include alkyl acrylates having an alkyl group having 1 to 20 carbon atoms at the ester terminal (that is, C _1-20 alkyl acrylate). An Ac block containing C _4-14 alkyl acrylate as a constituent monomer unit is preferred, and an Ac block containing C _4-9 alkyl acrylate is more preferred. Preferable examples of the C _4-9 alkyl acrylate include BA, 2EHA, n-hexyl acrylate, n-octyl acrylate, isooctyl acrylate (IOA), n-nonyl acrylate and isononyl acrylate (INA). For example, an Ac block containing at least one of BA and 2EHA is preferable.

In a preferred embodiment, the proportion of the C _4-14 alkyl acrylate in the monomer units constituting the Ac block is, for example, 50% by weight or more, may be 75% by weight or more, and is substantially 100% by weight (for example, 99% by weight). % To 100% by weight or less). For example, a constitution in which the monomer unit constituting the Ac block is substantially BA alone, a constitution in which 2EHA is alone, a constitution comprising two types of BA and 2EHA, and the like can be preferably employed. In the embodiment in which the monomer unit constituting the Ac block contains both BA and 2EHA, the weight ratio of BA to 2EHA is not particularly limited. The weight ratio of BA / 2EHA is, for example, 10/90 to 90/10, preferably 80/20 to 20/80, more preferably 30/70 to 70/30, and 60/40 to 40/60. Also good.

Examples of the alkyl methacrylate constituting the MAc block include C _1-20 (preferably C _1-14 ) alkyl methacrylate. The proportion of the C _1-4 (preferably C _1-3 ) alkyl methacrylate in the monomer constituting the MAc block may be, for example, about 50% by weight or more, about 75% by weight or more, and substantially 100% by weight. % (For example, more than 99% by weight and 100% by weight or less). Among these, preferred alkyl methacrylates include methyl methacrylate (MMA) and ethyl methacrylate (EMA). For example, a configuration in which the monomer unit is substantially MMA alone, a configuration in which the monomer unit is EMA alone, a configuration composed of two types of MMA and EMA, and the like can be preferably employed.

In one embodiment, the C _6-12 alkyl acrylate and the C _2-5 alkyl acrylate are 20/80 to 80/20 (more preferably 30/70 to 70/30, still more preferably 40/60 to 60/40, such as An acrylic block copolymer having an Ac block composed of monomer units contained in a weight ratio of 45/55 to 55/45) can be used. Such an acrylic block copolymer can be excellent in a balance between low-temperature performance and cohesion. For example, an acrylic block copolymer having an Ac block composed of monomer units containing 2EHA and BA in the above weight ratio can be preferably used. The Ac block may be composed only of 2EHA and BA.

  The weight ratio of Ac block / MAc block in the acrylic block copolymer is not particularly limited, and may be, for example, 4/96 to 90/10, 7/93 to 70/30, or 10/90 to 50/90. / 50, 15/85 to 40/60, or 15/85 to 25/75. In an acrylic block copolymer containing two or more MAc blocks, the weight ratio of the total weight of the MAc blocks to the Ac block is preferably in the above range. The same applies to an acrylic block copolymer containing two or more Ac blocks.

In addition, the composition of the monomer unit which comprises an acrylic block copolymer can be grasped | ascertained based on the result of NMR measurement. Specifically, the NMR measurement can be performed under the following conditions using, for example, “AVAVCEIII-600 (with Cryo Probe)” manufactured by Bruker Biospin as an NMR apparatus. For example, the weight ratio of 2EHA and MMA contained in the monomer raw material can be calculated based on the peak integrated intensity ratio of 4.0 ppm (2EHA1) and 3.6 ppm (MMA1) in the ¹ H NMR spectrum.
[NMR measurement conditions]
Observation frequency: ¹ H; 600 MHz
Flip angle: 30 °
Measuring solvent: CDCl ₃
Measurement temperature: 300K
Chemical shift standard: Measurement solvent (CDCl ₃ , ¹ H: 7.25 ppm)

The Mw of the acrylic block copolymer is not particularly limited, and may be about 3 × 10 ⁴ to 30 × 10 ⁴ . The Mw is usually preferably in the range of about 3.5 × 10 ^{4 to} 25 × 10 ⁴ , and more preferably in the range of 4 × 10 ^{4 to} 20 × 10 ⁴ (for example, 4.5 × 10 ⁴ to 15 × 10 ⁴ ). preferable.
In addition, Mw of an acrylic block copolymer here says the value of polystyrene conversion calculated | required by performing a gel permeation chromatography (GPC) about the sample prepared by melt | dissolving the said copolymer in tetrahydrofuran (THF). . Specifically, the GPC measurement can be performed under the following conditions using, for example, “HLC-8120GPC” manufactured by Tosoh Corporation as a GPC measurement apparatus. The Mw of other polymers and oligomers described below can be measured in the same manner.
[GPC measurement conditions]
Column: manufactured by Tosoh Corporation, TSKgel SuperHZM-H / HZ4000 / HZ3000 / HZ2000
Column size: 6.0 mmI. D. × 150mm
・ Eluent: THF
・ Flow rate: 0.6mL / min
・ Detector: Differential refractometer (RI)
Column temperature (measurement temperature): 40 ° C
Sample concentration: about 2.0 g / L (THF solution)
Sample injection volume: 20 μL

  Monomers (other monomers) other than alkyl (meth) acrylate may be copolymerized in the acrylic block copolymer in the technology disclosed herein. Examples of the other monomers include vinyl compounds having functional groups such as alkoxy groups, epoxy groups, hydroxyl groups, amino groups, amide groups, cyano groups, carboxy groups, and acid anhydride groups, vinyl esters such as vinyl acetate, and styrene. Examples thereof include aromatic vinyl compounds and vinyl group-containing heterocyclic compounds such as N-vinylpyrrolidone. The content of the other monomers may be about 20% by weight or less, about 10% by weight or less, or about 5% by weight or less of all monomer components constituting the acrylic block copolymer. In a preferred embodiment, the acrylic block copolymer contains substantially no other monomer. For example, an acrylic block copolymer in which the content of the above-mentioned other monomers is less than 1% by weight (typically 0 to 0.5% by weight) of the total monomer components or below the detection limit is preferable.

  Such an acrylic block copolymer can be easily synthesized by a known method (for example, see JP-A Nos. 2001-234146 and 11-323072), or a commercially available product can be easily obtained. It can be obtained. Examples of the above-mentioned commercially available products include Kuraray's product name “Clarity” series (for example, products having product numbers such as LA2140e and LA2250), Kaneka's product name “NABSTAR”, and the like.

The acrylic block copolymer can be used alone or in combination of two or more. For example, an acrylic block copolymer B _H having a relatively high Mw and an acrylic block copolymer _BL having a Mw lower than that of the acrylic block copolymer B _H are used in an appropriate weight ratio. it can. For example, a _{B H} where Mw is in the range of ^{5 × 10 4 ~20 × 10 4} ( e.g., ^{7 × 10 4 ~20 × 10 4} ), cutlet in a range of Mw of 3 × ^{10 4} ~8 × ¹⁰ 4 A combination with _BL lower than the Mw of _BH is preferred. The weight ratio (B _H / B _L ) between B _H and B _L is not particularly limited, and can be, for example, in the range of 5/95 to 95/5, and may be 10/90 to 90/10. 40/60 to 90/10, or 55/45 to 90/10. The inclusion of two or more kinds of acrylic block copolymers having different Mw, and the Mw and weight ratio of each acrylic block copolymer can be grasped through, for example, the GPC measurement described above.

  The acrylic pressure-sensitive adhesive layer can contain a tackifier as necessary. Examples of the tackifier include various rosin-based, terpene-based, hydrocarbon-based, epoxy-based, polyamide-based, elastomer-based, phenol-based, and ketone-based tackifier resins, one type alone or two types. The above can be used in appropriate combination. The compounding amount of the tackifier resin with respect to 100 parts by weight of the base polymer may be, for example, about 1 part by weight or more, about 5 parts by weight or more, or about 10 parts by weight or more. Further, from the viewpoint of avoiding deterioration of low temperature characteristics, the amount of tackifier used with respect to 100 parts by weight of the base polymer is usually appropriately about 50 parts by weight or less, may be about 30 parts by weight or less, and is about 20 parts by weight or less. But you can. The pressure-sensitive adhesive layer may not substantially contain a tackifier.

(Plasticizer)
The pressure-sensitive adhesive layer can contain a plasticizer as necessary. The plasticizer can be useful for lowering melt viscosity, suppressing adhesive strength, improving low temperature characteristics, and the like. Examples of plasticizers include: phthalates such as dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, dibutyl phthalate; adipates such as dioctyl adipate and diisononyl adipate; trimellitic acids such as trioctyl trimellitic acid Esters; sebacic acid esters; epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil; epoxidized fatty acid alkyl esters such as epoxidized fatty acid octyl ester; sorbitan monolaurate, sorbitan monostearate, sorbitan monooleate, sorbitan And cyclic fatty acid esters and derivatives thereof such as trioleate and their ethylene oxide adducts. Softeners such as process oil are also included in the plasticizer. A plasticizer can be used individually by 1 type or in combination of 2 or more types.

  The amount used in the case of using a plasticizer is not particularly limited. In one embodiment, the amount of tackifier used relative to 100 parts by weight of the base polymer may be about 1 part by weight or more, about 5 parts by weight or more, or about 10 parts by weight or more. From the viewpoint of preventing the migration of the plasticizer to the adherend, the amount of the plasticizer used is usually about 100 parts by weight or less with respect to 100 parts by weight of the base polymer, and may be about 50 parts by weight or less. It may be 30 parts by weight or less. The pressure-sensitive adhesive layer may not contain a plasticizer substantially.

  The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer may contain a polymer or an oligomer other than the base polymer as an optional component for the purpose of adjusting the viscosity and controlling the pressure-sensitive adhesive property (for example, reducing the pressure-sensitive adhesive force). As such a polymer or oligomer (hereinafter also referred to as an optional polymer), for example, an acrylic random copolymer having an Mw of about 500 to 10,000 (typically about 800 to 5000) can be used.

  The amount used in the case of using such an arbitrary polymer is not particularly limited. In one embodiment, the amount of the optional polymer used with respect to 100 parts by weight of the base polymer is, for example, 1 part by weight or more, 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, 25 It may be greater than or equal to parts by weight. In some embodiments, the amount of the optional polymer used relative to 100 parts by weight of the base polymer may be, for example, 70 parts by weight or less, 50 parts by weight or less, 40 parts by weight or less, or 35 parts by weight or less. . In some other embodiments, the amount of the optional polymer used relative to 100 parts by weight of the base polymer may be, for example, less than 5 parts by weight, less than 3 parts by weight, or less than 1 part by weight. The technology disclosed herein is an embodiment in which the pressure-sensitive adhesive does not substantially contain a polymer other than the base polymer, for example, an embodiment in which the amount of the optional polymer used is 0 to 0.5 parts by weight with respect to 100 parts by weight of the base polymer. It can be suitably implemented.

(Crosslinking agent)
The adhesive which comprises an adhesive layer may be bridge | crosslinked as needed. For crosslinking, organic metal salts such as zinc stearate and barium stearate, epoxy crosslinking agents, isocyanate crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, metal chelate crosslinking agents, melamine crosslinking agents, etc. A known crosslinking agent can be used. A crosslinking agent can be used individually by 1 type or in combination of 2 or more types. The amount of the crosslinking agent used is not particularly limited. In one embodiment, the amount of the crosslinking agent used relative to 100 parts by weight of the base polymer is about 0.01 parts by weight or more (typically about 0.02 parts by weight or more, for example, about 0.05 parts by weight or more). In addition, it can be about 10 parts by weight or less (for example, about 5 parts by weight or less). The pressure-sensitive adhesive layer may be non-crosslinked. This is preferable from the viewpoint of convenience and the like.

(Other ingredients)
In addition, various additions known in the field of pressure-sensitive adhesives such as fillers, anti-aging agents, antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, and dyes are added to the pressure-sensitive adhesive layer in the technology disclosed herein. Ingredients can be blended as needed. The types and blending amounts of these additional components that are not essential components may be the same as the usual types and blending amounts of this type of material.

  The pressure-sensitive adhesive as described above can be used for forming a pressure-sensitive adhesive layer in the form of an aqueous dispersion, an organic solvent solution or the like. In addition, an adhesive such as an active energy ray curable type or a hot melt type may be preferably used. Among these, a hot melt adhesive is preferable from the viewpoint of improving productivity and reducing environmental burden. The method of providing the pressure-sensitive adhesive layer on the surface of the laminated sheet is not particularly limited. For example, a method of directly applying a pressure-sensitive adhesive to the surface of the laminated sheet to form a pressure-sensitive adhesive layer (direct method), on an appropriate release surface A method of transferring the formed pressure-sensitive adhesive layer to a substrate (transfer method) or the like can be used. Conventionally known coating means such as a die coater and a gravure coater can be used for coating the adhesive. In the case of using a hot-melt pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer, the hot-melt pressure-sensitive adhesive can be applied in the form of a heated melt that does not substantially contain an organic solvent.

  Arbitrary appropriate thickness can be employ | adopted for the thickness of an adhesive layer in the range which does not impair the effect of this invention remarkably. The thickness is preferably 5 μm to 150 μm, more preferably 10 μm to 100 μm, still more preferably 20 μm to 80 μm, and particularly preferably 20 μm to 60 μm. When the thickness of the pressure-sensitive adhesive layer is in such a range, the effect of the present invention can be more manifested.

<Application>

  The polyurethane laminated sheet of the present invention can be used for any appropriate application that can effectively utilize the effects of the present invention. As an example of such a use, the base material (support body) of an adhesive sheet is mentioned. For example, it can be preferably used as a base material for a pressure-sensitive adhesive sheet for medical use or hygiene material.

  The pressure-sensitive adhesive sheet of the present invention can be used for any appropriate application that can effectively use the effects of the present invention. Examples of such applications include pressure-sensitive adhesive sheets for medical or sanitary materials. In particular, it can be suitably used as a pressure-sensitive adhesive sheet for medical or hygiene materials and for skin application. Typical examples of the adhesive sheet for skin application include surgical dressing tape, wound protection tape, and adhesive bandage.

  Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in the examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.

The polyurethane raw materials used in the following examples are as follows.
TPU1: Thermoplastic ether polyurethane (Product name: PANDEX EX-6880N, manufactured by DIC Covestro Polymer Co., Ltd.)
TPU2: Thermoplastic ether polyurethane (Product name: PANDEX T-8180N, manufactured by DIC Covestro Polymer Co., Ltd.)
TPU3: Thermoplastic ether polyurethane (Product name: Resamine PM2081, manufactured by Dainichi Seika Kogyo Co., Ltd.)

In addition, about the polyurethane raw material used in the following examples, about the polyurethane sheet produced using 100% of each, the result of having performed the water-swellability test mentioned later and a water vapor transmission rate measurement was as follows.
TPU1: Water swellable, moisture permeability at 20 μm thickness: 5000 g / (m ² · 24 hours)
TPU2: No water swellability, moisture permeability at a thickness of 20 μm: 450 g / (m ² · 24 hours)
TPU3: No water swellability, moisture permeability at a thickness of 20 μm: 2000 g / (m ² · 24 hours)

<Example 1>
By using a polyurethane raw material shown in Table 1 and low density polyethylene (product name: Sumikasen G-701, manufactured by Sumitomo Chemical Co., Ltd.) as a raw material for the carrier sheet, the first polyurethane is extruded by three layers with a T-die extruder. A polyurethane laminated sheet with a carrier sheet according to Example 1 having a configuration in which a layer, a second polyurethane layer, and a carrier sheet were laminated in this order was produced. The thicknesses of the first polyurethane layer and the second polyurethane layer at this time were as shown in Table 1. The thickness of the carrier sheet was 50 μm.

A pressure-sensitive adhesive composition was prepared by mixing 100 parts of an acrylic polymer, 30 parts of an acrylic oligomer, and 30 parts of a plasticizer in a heated and melted state. As the acrylic oligomer, “Alfon UP1021” (non-functional group type, Mw about 1600) manufactured by Toagosei Co., Ltd. was used. As the plasticizer, a trade name “Monocizer W-242” (diisononyl adipate) manufactured by DIC Corporation was used. Examples of the acrylic polymer include polymethyl methacrylate (MMA) block-poly 2-ethylhexyl acrylate (2EHA) / n-butyl acrylate (BA) block-polymethyl methacrylate (MMA) block (hereinafter referred to as "MMA-2EHA / BA-"). MMA ”) and a weight ratio of 2EHA to BA in the poly-2EHA / BA block (that is, a copolymerization ratio based on weight) of 50/50, and poly-2EHA An acrylic block copolymer having a ratio (MMA / (2EHA + BA)) of the weight of the polyMMA block to the weight of the / BA block (total weight of the two polyMMA blocks) (18/82) was used. This acrylic block copolymer was synthesized by a known living anion polymerization method, and Mw was 10 × 10 ⁴ and Mn was 8.4 × 10 ⁴ .

  The pressure-sensitive adhesive composition was applied to the surface on the first polyurethane layer side of the polyurethane laminated sheet with a carrier sheet according to Example 1 in a molten state by gravure coating to prepare a pressure-sensitive adhesive sheet. The pressure-sensitive adhesive sheet thus obtained was used as a pressure-sensitive adhesive sheet with a carrier sheet according to Example 1. The thickness of the adhesive layer was 40 μm.

<Examples 2-3 and Comparative Examples 1-3>
Except that the composition and thickness of the first polyurethane layer and the second polyurethane layer were as shown in Table 1, Examples 2-3 and Comparative Examples were produced by the same production method as the pressure-sensitive adhesive sheet with a carrier sheet according to Example 1. The adhesive sheet with a carrying sheet according to 1 to 3 was produced.

[Measurement of moisture permeability (cup method)]
The moisture permeability of the polyurethane laminate sheet according to each example was measured according to a moisture permeability test (cup method) of JIS Z0208. Specifically, the carrier sheet is peeled and removed from the polyurethane laminated sheet with the carrier sheet according to each example, and the diameter is adjusted according to the diameter of the test cup (aluminum, diameter 30 mm, cup used in the cup method of JIS Z0208). What was cut into a 30 mm circular shape was used as a test sample. And the mouth of the cup was sealed with the test sample produced above in a state where a predetermined amount of calcium chloride was put inside the cup. By measuring the weight change of calcium chloride before and after leaving the cup covered with the test sample in a constant temperature and high humidity chamber at 40 ° C. and 90% RH for 24 hours, moisture permeability [g / (m ² -24 hours)].

[Non-softening test]
About the adhesive sheet which concerns on each example, it was evaluated based on the following test results about the difficulty (no maceration property) of the maceration phenomenon when this adhesive sheet was affixed on human skin. First, the pressure-sensitive adhesive sheet with a carrier sheet according to each example was cut into a rectangular shape of 80 mm × 20 mm, wrapped around a human index finger and pasted, and then the carrier sheet was quickly peeled and removed from the pressure-sensitive adhesive sheet. The adhesive sheet was peeled from the finger 24 hours after applying the adhesive sheet, and the skin condition at that time was visually observed. As a result, the non-softening property of the pressure-sensitive adhesive sheet was evaluated in the following two stages.
When the skin is in a normal state (that is, a state where the skin is not white): Good non-softening property (◯)
When the skin is white and soft: Non-immobility defect (×)

[Water swelling test]
About the adhesive sheet which concerns on each example, the water swelling property was measured as follows. First, the carrier sheet is peeled off from the adhesive sheet with the carrier sheet according to each example, and 3 drops of deionized water at a temperature of 23 ° C. are dropped on the surface of the adhesive sheet on the second polyurethane layer side using a Komagome pipette. After the elapse of minutes, the moisture on the evaluation target sheet was wiped off with a waste cloth, and whether or not the water droplet dropping portion of the evaluation target sheet was swollen was visually observed from the side. As a result, when no swelling was observed, water swellability was not observed (good non-water swellability: ◯), and when swelling was observed, water swellable (non-water swellability was poor: x). The results are shown in the column of “Non-water swellability” in Table 1.

  In addition, all the 1st polyurethane layers which concern on Examples 1-3 were water-swellable, and none of the 2nd polyurethane layer which concerns on Examples 1-3 was water-swellable. Further, as is apparent from the results shown in Table 1, the pressure-sensitive adhesive sheet containing a laminated sheet having a high moisture permeability as a base material tended to show a good non-softening result.

  As is apparent from the results shown in Table 1, Example 1 including a polyurethane laminated sheet formed by laminating a first polyurethane layer having water swellability and a second polyurethane layer having no water swellability as a base material. According to the pressure-sensitive adhesive sheet according to -3, it was found that the non-softening result was good and the non-water swellability was good.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

10 Polyurethane laminated sheet (Laminated sheet)
12 one surface 14 other surface 20 first polyurethane layer 30 second polyurethane layer 40 carrying sheet 50 adhesive sheet 60 adhesive layer

Claims (7)

A polyurethane laminate sheet comprising a first polyurethane layer made of a first polyurethane material and a second polyurethane layer made of a second polyurethane material,
The first polyurethane material has water swellability,
The second polyurethane material has no water swellability;
Polyurethane laminated sheet characterized by The first polyurethane material has a moisture permeability of 3000 g / (m ² · 24 hours) or more at a thickness of 20 μm,
The polyurethane laminate sheet according to claim 1, wherein the second polyurethane material has a moisture permeability of not more than 2500 g / (m ² · 24 hours) at a thickness of 20 µm. The thickness D ₂ of the second polyurethane layer is 8μm or less, the polyurethane laminated sheet according to claim 1 or 2. The thickness D ₁ of the first polyurethane layer is 10μm or more, the polyurethane laminated sheet according to any one of claims 1 to 3. The polyurethane laminate according to claim 1, wherein D ₁ / D _2, which is a ratio of the thickness D ₁ of the first polyurethane layer to the thickness D ₂ of the second polyurethane layer, is 3 to 20. 5. Sheet. The polyurethane laminate sheet according to any one of claims 1 to 5,
An adhesive layer provided on the surface of the polyurethane laminate sheet on the first polyurethane layer side;
Adhesive sheet containing.   The pressure-sensitive adhesive sheet according to claim 6, wherein the pressure-sensitive adhesive layer contains a hot-melt pressure-sensitive adhesive.

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