JP2014009318A - Pressure-sensitive adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive tape excellent both in rewinding property and in overlap adhesion property on a self back surface.SOLUTION: A pressure-sensitive adhesive tape 10 comprises: a support 1; a release agent layer 2; and a pressure-sensitive adhesive layer 3. The support 1 is formed by laminating an aluminum foil layer 13 on one surface of a glass fiber woven fabric layer 11 through an adhesive layer 12. The release agent layer 2 is laminated on the surface on the aluminum foil layer 13 side of the support, and the pressure-sensitive adhesive layer 3 is laminated on the surface on the glass fiber woven fabric layer 11 side thereof. The release agent layer 2 contains a release agent comprising a long-chain alkyl group-containing compound having a hydroxyl group, and trifluoroacetic anhydride is brought into contact with the surface of the release agent layer 2 in a gas phase to thereby chemically modify a hydroxyl group existing on the surface. The F content rate in element analysis by ESCA is 0.5 atomic% or more and 6.0 atomic% or less.

Description

  The present invention relates to an adhesive tape.

  In interior construction of houses, buildings, etc., heat insulating materials are attached to ceilings, walls, and pipes passing through them to prevent heat dissipation and heat absorption. The joint (joint) of the heat insulating material is usually fixed with an adhesive tape. In such applications, the adhesive tape is mainly an adhesive tape (aluminum glass cloth tape) that uses an aluminum glass cloth bonded to a glass fiber woven fabric (glass cloth) and aluminum foil as it has excellent heat insulation properties. It is used. In the aluminum glass cloth tape, the pressure-sensitive adhesive layer is usually provided on the glass cloth side of the support.

When fixing a joint of a heat insulating material wound around a pipe such as a duct, the end of the aluminum glass cloth tape is often overlaid on the back surface of the tape. There are cases where floating and peeling occur over time at the overlapped portion. In order to suppress this floating and peeling as much as possible, the aluminum glass cloth tape is required to have a large adhesive force to the back surface (against the back surface adhesive force) as well as an adhesive force to the heat insulating material.
Therefore, the conventional aluminum glass cloth tape does not perform any treatment on the aluminum foil surface that is the back surface, and the adhesive layer is protected with a release paper so that the adhesive layer does not contact the back surface before use. It was. Such aluminum glass cloth tape is usually wound in a tape shape with the release paper side inside, and when used, the necessary length is rewound and cut, and the release paper is peeled off to remove the heat insulating material. Affixed to the seam.

In recent years, from the viewpoint of reducing dust associated with environmental problems, a product form that does not use release paper has been required.
In that case, it is proposed to provide a release agent layer on the aluminum foil surface of the aluminum glass cloth instead of protecting the adhesive layer with release paper (for example, Patent Documents 1 and 2).

JP 2003-301150 A JP 2004-210810 A

However, when the release agent layer is provided on the aluminum foil surface, the overlayability becomes insufficient, such as floating or peeling when the laminate is applied to the back surface of the aluminum foil.
If the adhesive force of the pressure-sensitive adhesive layer is increased from the viewpoint of layering, the unwinding force increases and workability deteriorates. Furthermore, there arises a problem that the release agent layer adheres firmly to the surface of the pressure-sensitive adhesive layer and peels off from the aluminum foil surface during rewinding and moves to the pressure-sensitive adhesive layer side. When the release agent layer moves to the surface of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer to the back surface or the surface to be fixed (such as a heat insulating material) decreases.
Therefore, an aluminum glass cloth tape that can achieve both rewinding properties that are contradictory properties and lap pastability to the back surface, that is, the rewinding force is light, and the release agent layer is difficult to move to the adhesive layer during rewinding, There is a need for an aluminum glass cloth tape that does not easily float or peel off when it is laminated on its back.
In addition, in patent documents 1 and 2, in order to suppress the adhesive force change with respect to environmental changes and suppress the floating and peeling of the adhesive tape, the application amount and type of the adhesive, the weight of the glass fiber woven fabric, and the like are specified. As described above, there is no disclosure regarding reconciliation between the rewinding property, which is a conflicting characteristic, and the ability to overlap the self-back surface.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing both the rewinding property and the overlaying property to a self-back surface with favorable.

  As a result of intensive studies, the present inventors have, as a release agent constituting the release agent layer, a long-chain alkyl group-containing compound-type release agent containing a hydroxyl group within a predetermined range on the surface of the formed release agent layer. The present invention has been completed by finding that the above-mentioned problems can be solved by using the hydroxyl group so as to exist.

The present invention has the following aspects.
[1] A support, a release agent layer, and an adhesive layer are provided.
The support is formed by laminating an aluminum foil layer via an adhesive layer on one side of a glass fiber woven fabric layer,
The release agent layer is laminated on the surface of the support on the aluminum foil layer side, the pressure-sensitive adhesive layer is laminated on the surface of the glass fiber woven fabric layer side,
The release agent layer contains a release agent comprising a long-chain alkyl group-containing compound having a hydroxyl group,
When the surface of the release agent layer is brought into contact with trifluoroacetic anhydride in the gas phase to chemically modify the hydroxyl group present on the surface and the elemental analysis by ESCA is performed, the F content is 0.5 atomic% or more 6. Adhesive tape that is 6.0 atomic% or less.
[2] The pressure-sensitive adhesive tape according to [1], wherein the long-chain alkyl group-containing compound having a hydroxyl group has a melting point of 88 ° C or higher and 105 ° C or lower.
[3] The back surface peeling force (a) at a tensile speed of 3 m / min is 8 N / 10 mm or less, and the self back surface peeling force (a) and the self back surface peeling force (b) at a pulling speed of 30 m / min. The adhesive tape according to [1] or [2], wherein and have a relationship of (a) / (b) ≧ 1.0.
[4] The adhesive tape according to any one of [1] to [3], wherein the adhesive constituting the adhesive layer is a hot-melt adhesive.
[5] The pressure-sensitive adhesive tape according to any one of [1] to [4], wherein a coating amount of the pressure-sensitive adhesive layer is 60 g / m ² or more and 180 g / m ² or less.

  ADVANTAGE OF THE INVENTION According to this invention, both the rewinding property and the overlap sticking property to the self back surface can provide a favorable adhesive tape.

It is a schematic sectional drawing explaining the laminated constitution of the adhesive tape 10 which concerns on one Embodiment of this invention.

  Hereinafter, the pressure-sensitive adhesive tape of the present invention will be described with reference to the accompanying drawings by showing embodiments.

<First embodiment>
FIG. 1 is a schematic cross-sectional view illustrating the layer configuration of the pressure-sensitive adhesive tape 10 according to the first embodiment of the present invention.
The pressure-sensitive adhesive tape 10 includes a support 1, a release agent layer 2, and a pressure-sensitive adhesive layer 3.
The support 1 is formed by laminating an aluminum foil layer 13 on one side of a glass fiber woven fabric layer 11 with an adhesive layer 12 interposed therebetween.
In the pressure-sensitive adhesive tape 10, the release agent layer 2 is laminated on the surface of the support 1 on the aluminum foil layer 13 side, and the pressure-sensitive adhesive layer 3 is laminated on the surface of the support 1 on the glass fiber woven fabric layer 11 side.

{Support 1}
It does not specifically limit as a glass fiber woven fabric which comprises the glass fiber woven fabric layer 11 in the support body 1, It can select suitably from what is known as a glass fiber woven fabric used for an aluminum glass cloth tape. For example, various glass cloths defined in JIS R3414 (2007), such as EP11E, EP11D, EP12E, etc. can be used.
As the glass fiber woven fabric, EP11E and EP11D are preferable.

The adhesive constituting the adhesive layer 12 in the support 1 is not particularly limited as long as it can adhere the glass fiber woven fabric and the aluminum foil, and can be appropriately selected from known adhesives.
Specific examples of the adhesive include acrylic adhesives, polyester adhesives, ethylene-vinyl acetate copolymer adhesives, vinyl chloride-vinyl acetate copolymer adhesives, urethane adhesives, and the like.
Other adjuvants may be added to the adhesive as necessary. Examples of the other auxiliary agent include pigments.
The thickness of the adhesive layer 12 is preferably in the range of 0.05 to 20 μm, and more preferably in the range of 0.5 to 10 μm.

It does not specifically limit as aluminum foil which comprises the aluminum foil layer 13 in the support body 1, A well-known thing can be used as aluminum foil used for an aluminum glass cloth tape.
The thickness of the aluminum foil is preferably in the range of 5 to 50 μm, and more preferably in the range of 15 to 30 μm.

The support 1 can be produced by bonding an aluminum foil to a glass fiber woven fabric with an adhesive. Bonding can be performed by a known method.
As the support 1, one prepared as described above may be used, or a commercially available one may be used.

{Release agent layer 2}
The release agent layer 2 contains a release agent composed of a long-chain alkyl group-containing compound having a hydroxyl group.
The “long-chain alkyl group-containing compound” is a kind of non-silicone release agent, and the long-chain alkyl group reduces the surface tension of the release agent layer 2. As the long-chain alkyl group-containing compound, a polymer having a long-chain alkyl group in the side chain is generally used. For example, a long-chain alkyl acrylate polymer, a long-chain alkyl-modified polymer, and the like are known. 8-30 are preferable and, as for carbon number of a long-chain alkyl group, 12-25 are more preferable.

The long-chain alkyl group-containing compound used as a release agent in this embodiment has a hydroxyl group in addition to the long-chain alkyl group.
Examples of the long-chain alkyl group-containing compound having a hydroxyl group include compounds in which a long-chain alkyl group is introduced into part of the hydroxyl group of a polymer having a hydroxyl group.
Examples of the polymer having a hydroxyl group include polyvinyl alcohol polymers, saponified ethylene vinyl acetate copolymers, cellulose, cellulose derivatives obtained by chemically modifying a part of the hydroxyl groups of cellulose, and the like.
The average degree of polymerization of these polymers is preferably in the range of 100 to 5000, and preferably in the range of 1000 to 3000.
The saponification degree of the polyvinyl alcohol or ethylene vinyl acetate copolymer is preferably 80 to 100%, and more preferably 90 to 100%.

The long-chain alkyl group-containing compound having a hydroxyl group preferably has a melting point of 88 ° C. or higher and 105 ° C. or lower, and more preferably 94 ° C. or higher and 100 ° C. or lower.
When the melting point is 88 ° C. or higher, the release agent layer 2 is difficult to soften, for example, in the summer. When the release agent layer 2 is softened, the components of the release agent layer 2 may be transferred to the adhesive layer 3 in contact with the release agent layer 2 and the adhesive strength of the adhesive layer 3 may be reduced. There is a possibility that the release agent layer 2 and the pressure-sensitive adhesive layer 3 adhere to each other and the pressure-sensitive adhesive tape 10 is difficult to rewind.
When the melting point is 105 ° C. or lower, the adhesion of the release agent layer 2 to the aluminum foil layer 13 is good.
The melting point of the long-chain alkyl group-containing compound is not particularly limited, but is measured by a differential scanning calorimetry (DSC) method.

A long-chain alkyl group-containing compound having a hydroxyl group can be produced, for example, by introducing a long-chain alkyl group into a polymer having a hydroxyl group (alkyl modification). Introduction of a long chain alkyl group into a polymer having a hydroxyl group can be carried out by a known method. For example, a method of reacting a chloride of a fatty acid having a long chain alkyl group (stearoyl chloride, etc.), a long chain alkyl isocyanate (stearyl isocyanate, Octadecyl isocyanate etc.) can be reacted.
The melting point of the obtained long-chain alkyl group-containing compound can be adjusted by adjusting the introduction rate of the long-chain alkyl group at this time. Usually, the higher the introduction rate of the long-chain alkyl group (the lower the hydroxyl ratio), the higher the melting point.

The thickness of the release agent layer 2 is, as the mass per unit area of the release agent layer 2 (dry coating amount), 0.02 g / ^{m 2} or more 1 g / ^{m 2} or less is preferable, 0.20 g / ^{m 2} or more 0. 60 g / m ² or less is more preferable.
When the mass is 0.02 g / m ² or more, a uniform film is formed on the surface of the uneven support 1, and the release agent layer 2 is partially pulled out and the unwinding force is significantly increased. Can be suppressed.
If the mass exceeds 1 g / m ² , the release agent layer 2 may cause interlaminar cracking during rewinding, and may partially move to the adhesive layer 3 to reduce the adhesive strength.

The release agent layer 2 chemically modifies the hydroxyl groups present on the surface of the release agent layer 2 by bringing trifluoroacetic anhydride into contact with the surface of the release agent layer 2 (the surface opposite to the aluminum foil layer 13 side) in the gas phase. When the elemental analysis is performed by ESCA (Electron spectroscopy for chemical analysis), the F content is 0.5 atomic% or more and 6.0 atomic% or less.
The F content is preferably 0.8 atomic% or more and 5.5 atomic% or less, and more preferably 1.0 atomic% or more and 5.0 atomic% or less.

When trifluoroacetic anhydride (gaseous trifluoroacetic anhydride) is brought into contact with the surface of the release agent layer 2 in the gas phase, the hydroxyl group on the surface reacts with trifluoroacetic anhydride and is chemically modified (acetylated). The
The reaction at this time is specifically as follows.
R—OH + (CF ₃ CO) ₂ O → R—OCOCF ₃ + CF ₃ COOH

The long-chain alkyl group-containing compound used as the release agent does not have a fluorine atom, and the surface of the release agent layer 2 containing this does not have a fluorine atom before contacting with trifluoroacetic anhydride. . In addition to the hydroxyl group derived from the long-chain alkyl group-containing compound, there is no group that can react with trifluoroacetic anhydride. Therefore, the elemental analysis by ESCA of the surface is performed to measure the elemental composition on the surface, and the F content obtained thereby is derived from the long-chain alkyl group-containing compound existing on the surface in contact with trifluoroacetic anhydride. This corresponds to the amount of hydroxyl groups.
When the F content is within the above range, that is, when a predetermined amount of hydroxyl groups derived from the long-chain alkyl group-containing compound is present on the surface of the release agent layer 2, the rewinding property and the self-propagating property are reduced. It is possible to achieve both stackability on the back side.

The reason why the above effect is obtained is not clear, but the following can be considered.
First, by using a long-chain alkyl group-containing compound as a release agent, it is possible to increase the peel force at a low tensile speed (for example, 3 m / min) and lighten the peel force at a high tensile speed (for example, 30 m / min). it can. The heavier the peeling force at a low tensile speed, the less likely the floating or peeling will occur after being stuck on the back surface. In addition, the lighter the peeling force at a high tensile speed, the easier it is to peel from the back surface during rewinding, and the rewinding force becomes lighter.
In the case of a general silicone release agent as the release agent, the release force tends to increase as the tensile speed increases. Therefore, if the peeling force at a low tensile speed is increased, the peeling force at a high tensile speed, and thus the unwinding force, is considerably increased. Further, if the peeling force at a high tensile speed is lightened, the peeling force at a low tensile speed is considerably lightened, and it tends to float or peel off after being laminated on the back surface.
Moreover, a hydroxyl group exists in the surface by the side of the aluminum foil layer 13 of the releasing agent layer 2 formed by using what has a hydroxyl group as a long-chain alkyl group containing compound. This hydroxyl group improves the interlayer adhesion between the aluminum foil layer 13 and the release agent layer 2. If the F content is within the above range, a sufficient amount of hydroxyl groups for improving interlayer adhesion is present on the surface of the release agent layer 2 on the aluminum foil layer 13 side. When the interlayer adhesion between the aluminum foil layer 13 and the release agent layer 2 is sufficiently increased, the release agent layer 2 is less likely to move to the pressure-sensitive adhesive layer 3 during rewinding. The decrease is suppressed, and it is considered that floating and peeling are less likely to occur when the adhesive tape 10 is laminated on the back surface.

  The F content can be adjusted by the hydroxyl group content of the long-chain alkyl group-containing compound used as the release agent. For example, as the hydroxyl group content of the long-chain alkyl group-containing compound increases, the F content tends to increase.

More specifically, the chemical modification of the hydroxyl group on the surface of the release agent layer 2 with trifluoroacetic anhydride can be performed by the following procedure.
Chemical modification is performed at room temperature (23 ° C.) in a glass desiccator, and the exposure time (reaction time) of the sample to trifluoroacetic anhydride is 2 hours.
After chemical modification, in order to remove trifluoroacetic anhydride physically adsorbed on the sample surface, the sample is transferred to a plastic vacuum desiccator and left in a vacuum for 2 hours or longer.

In this specification, elemental analysis by ESCA is performed under the following conditions.
The X-ray source may be either Al or Mg.
The measurement area is in the range of 0.4 to 8 mm in diameter.

The release agent layer 2 can be formed by a known method.
For example, the release agent layer 2 can be formed by applying a coating liquid containing the release agent to the surface of the support 1 on the aluminum foil layer 13 side and drying.
The coating solution can be prepared, for example, by dissolving the long-chain alkyl group-containing compound in an organic solvent.
The coating liquid can be applied using a known coating apparatus, and examples of the coating apparatus include a gravure coater, a bar coater, and a roll coater.
As a drying method, a known drying method such as hot air drying, infrared drying, vacuum drying, or the like can be applied.

{Adhesive layer 3}
As an adhesive which comprises the adhesive layer 3, it can select suitably from well-known things as an adhesive used for adhesive tapes, such as an aluminum glass cloth tape.
For example, the type of pressure-sensitive adhesive includes natural rubber-based pressure-sensitive adhesives, synthetic rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, etc., depending on the type of main component resin. Can be used.
Examples of the dosage form of the pressure-sensitive adhesive include a solvent type, an emulsion type, a solventless type, and a hot melt type, and any dosage form may be used. Among these, a hot-melt pressure-sensitive adhesive is particularly preferable from the viewpoints that it is not necessary to remove the solvent or the dispersion medium and the environmental load is low.
If necessary, other auxiliary agents may be added to the pressure-sensitive adhesive. Examples of the other auxiliaries include antioxidants, UVA, light stabilizers, pigments, colorants, and tackifiers.

The pressure-sensitive adhesive layer 3 preferably has an adhesive strength to a stainless steel plate measured by the following measurement method of 5 to 15 N / 10 mm, and more preferably 7 to 13 N / 10 mm.
(Measurement method for adhesion to stainless steel plate)
In an environment of 23 ° C. and 50% RH, one piece of adhesive tape 10 wound in a roll shape was sampled with a size of 25 mm width × 100 mm length, and this was applied to a stainless steel plate polished with # 280 abrasive paper. The pressure-sensitive adhesive layer 3 side is bonded to the stainless steel plate side, reciprocated once with a 2 kg roller, left to stand for 30 minutes, and then in a 180 ° direction at a speed of 300 mm / min with a tensile tester. The peel strength when peeled by pulling is measured, and the measured value is defined as the adhesive strength against a stainless steel plate.

When the adhesive strength is 5 N / 10 mm or more, the joint (joint) of the heat insulating material can be sufficiently fixed. Moreover, it is excellent in adhesive strength against the back surface, and does not easily float or peel over time when it is laminated on the back surface.
When the adhesive strength is 15 N / 10 mm or less, the rewinding force is sufficiently light and the workability is excellent. Further, it is difficult to cause a problem that the release agent layer 2 is peeled off during rewinding and transferred to the surface of the pressure-sensitive adhesive layer 3.
The pressure-sensitive adhesive force can be adjusted by the type of pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3, the amount of pressure-sensitive adhesive applied, the amount of an auxiliary agent (tackifier, etc.) to be blended in the pressure-sensitive adhesive.

The thickness of the adhesive layer 3, as the mass per unit area of the adhesive layer 3 (dry coating amount) is preferably from 60 g / ^{m 2} or more 180 g / ^{m 2} or less, 80 g / ^{m 2} or more 150 g / ^{m 2} or less More preferred.
Adhesive force sufficient for fixing the joint (joint) of the heat insulating material is obtained when the mass is 60 g / m ² or more. In addition, the adhesive strength of the adhesive tape to the back surface is improved, and it is difficult for floating and peeling with time to occur when the adhesive tape is laminated on the back surface.
When the mass exceeds 180 g / m ² , the adhesive strength reaches a peak, which is not preferable in terms of cost. Further, the pressure-sensitive adhesive layer becomes fragile to stress applied in the shear direction, and cohesive failure is likely to occur.

The pressure-sensitive adhesive layer 3 can be formed by a known method.
For example, the pressure-sensitive adhesive layer 3 can be formed by applying a pressure-sensitive adhesive to the surface of the support 1 on the side of the glass fiber woven fabric 11 and drying it as necessary.
The pressure-sensitive adhesive can be applied using a known coating apparatus, and examples of the coating apparatus include a gravure coater, a bar coater, a roll coater, a comma coater, a lip coater, and a hot melt coater.
As a drying method, a known drying method such as hot air drying, infrared drying, vacuum drying, or the like can be applied.

  The pressure-sensitive adhesive tape 10 is usually a laminate in which the release agent layer 2 is laminated on one side of the support 1 and the pressure-sensitive adhesive layer 3 is laminated on the other side. It is in a state of being wound up in a tape shape so as to be in contact with the back surface (release agent layer 2), and at the time of use, a necessary length is rewound and cut off.

The pressure-sensitive adhesive tape 10 has a back surface peeling force (a) of 8 N / 10 mm or less at a tensile speed of 3 m / min.
When the back surface peeling force (a) is 8 N / 10 mm or less, the resistance at the start of rewinding is small and the workability is excellent. The smaller the value of the self-back surface peeling force (b), the lighter the rewinding force is sufficiently light and the better the workability.
When the self-back surface peeling force (a) is 1 N / 10 mm or more, when the self-back surface is overlaid, the tape does not easily lift or peel off at the overlapped portion, and the tape does not peel off by its own weight.

In the pressure-sensitive adhesive tape 10, the self-back surface peeling force (a) is 8 N / 10 mm or less, and the self-back surface peeling force (a) and the self-back surface peeling force (b) at a tensile speed of 30 m / min are (a ) / (B) ≧ 1.0.
When (a) / (b) is 1.0 or more, that is, the self-back surface peeling force at a tensile speed of 30 m / min is equal to or lower than the self-back surface peeling force at a tensile speed of 3 m / min, Unwinding force is light enough and workability is excellent.

The back surface peeling force (b) is preferably 1 to 8 N / 10 mm.
When the self-back surface peeling force (b) is 8 N / 10 mm or less, the rewinding force is sufficiently light and the workability is excellent.
When the back surface peeling force (b) is 1 N / 10 mm or more, there is an appropriate peeling force, and workability is not impaired.

The self-rear peeling force of the adhesive tape 10 is a value measured by the following measuring method.
(Measurement method of self-peeling force)
Two sheets overlapped from the pressure-sensitive adhesive tape 10 wound in a roll shape at 23 ° C. and 50% RH are sampled to a size of 25 mm wide × 100 mm long, and one sheet overlapping the two surfaces of the release agent layer is subjected to a peeling test. The peel strength when peeled by pulling in a 180 degree direction at a predetermined tensile speed (3 m / min or 30 m / min) with a machine is measured, and the measured value is taken as the self-rear peeling force.

As mentioned above, although the example of embodiment was shown and demonstrated about the adhesive tape of this invention, this invention is not limited to the said embodiment. Each configuration in the above embodiment, a combination thereof, and the like are examples, and the addition, omission, replacement, and other modifications of the configuration can be made without departing from the spirit of the present invention.
For example, you may provide a printing layer arbitrarily.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited thereto.
The melting point of the release agent obtained in the following synthesis example was measured by DSC method. The analysis and measurement of the adhesive tapes obtained in the examples and comparative examples (elemental analysis by ESCA, self-back surface peeling force (tensile speed 3 m / min, 30 m / min), stainless steel plate adhesive force, self-back surface holding force) are respectively The following procedure was used.

(Elemental analysis by ESCA)
The measurement method by ESCA method of fluorine existing on the surface of the release agent layer was measured using a photoelectron spectroscopic analyzer (ESCALAB-250, manufactured by VG Scientific), and the proportion of fluorine was measured. .

(Self-removal force)
In an environment of 23 ° C. and 50% RH, two sheets that are overlapped from the adhesive tape wound in a roll shape are sampled to a size of 25 mm width × 100 mm length, and one sheet that overlaps the release agent layer surface is used as a peeling tester. Then, the peel strength when the film was peeled by pulling in the direction of 180 degrees at a predetermined tensile speed (3 m / min or 30 m / min) was measured, and the measured value was taken as the self-rear peeling force.

(Adhesive strength to stainless steel plate)
In an environment of 23 ° C. and 50% RH, one piece of adhesive tape wound in a roll was sampled with dimensions of 25 mm width × 100 mm length, and this was adhered to a stainless steel plate polished with # 280 abrasive paper. The surface on the side of the agent layer is bonded to the stainless steel plate side, reciprocated once with a 2 kg roller, and left for 30 minutes, and then pulled in a 180 ° direction at a speed of 300 mm / min with a tensile tester. The peel strength when peeled was measured. The measured value was defined as the adhesion to stainless steel plate.

(Self-retaining force)
In an environment of 23 ° C. and 50% RH, one piece of adhesive tape wound in a roll is sampled with dimensions of 25 mm width × 100 mm length, and this is a release agent for aluminum glass cloth tape bonded to a stainless steel plate. The film was bonded to the surface, reciprocated once with a 2 kg roller, allowed to stand for 30 minutes, and then allowed to stand for 24 hours under a load of 1 kg. After 24 hours, the length shifted in the vertical direction from the position before applying the load was measured, and the length (mm) was defined as the self-rear surface holding force. When the sample dropped before 24 hours passed, the time until dropping was described.

(Own back edge lift)
A heat insulating material (trade name: thermal insulation tube ALGC, product symbol GWPALGC, inner diameter 34 mm, thickness 25 mm, manufactured by Asahi Fiber Glass Co., Ltd.) wrapped around a stainless steel pipe with an outer diameter of 36 mm is wound on the surface to a joint (joint). Wrap the test piece (one piece of adhesive tape wound in a roll shape, sampled at a size of 50 mm x 50 mm) so that the end of the test piece overlaps the back surface (overlap width 20 mm), and overlap After the part was pressure-bonded once in a circumferential direction with a 500 g roll, it was allowed to stand in a test room at −10 ° C., 23 ° C., 50% RH, or 40 ° C., 65% RH, and the floating state after 24 hours was evaluated. .
(Double-circle): It does not float to an overlap part, and the opening of a joint (joint) is not seen.
○: Although there is a slight detachment in the overlap portion, the seam (joint) is not opened.
(Triangle | delta): The opening of a joint (joint) is seen by the peeling of an overlap part or the shift | offset | difference of a test piece position.
X: The test piece was peeled off and the joint (joint) was completely opened.

<Synthesis Examples 1 to 5: Synthesis of release agent>
In a reaction vessel equipped with a stirrer, a cooler and a dropping funnel, 100 parts by mass of xylene was added to 10 parts by mass of polyvinyl alcohol (saponification degree 96%, average polymerization degree 1200), and the mixture was refluxed to remove moisture. Thereto was added octadecyl isocyanate, which had been preheated to 50 ° C., little by little, and the mixture was reacted at 140 ° C. with stirring for 3 hours. After the reaction, the reaction product was cooled to 80 ° C. and filtered to obtain a xylene solution of the desired release agent (reaction product of polyvinyl alcohol and octadecyl isocyanate).
At this time, five kinds of release agents 1 to 5 having different melting points were obtained by appropriately changing the addition amount of octadecyl isocyanate.
The melting points of the release agents 1 to 5 were measured. The results are shown in Table 1.
The higher the amount of octadecyl isocyanate added (the lower the hydroxyl group remaining after the reaction), the higher the melting point.

<Example 1>
As a support, use is made of a plain woven fabric using a filament diameter of 13 μm and 200 filaments as defined in JIS R3413, and an aluminum foil having a thickness of 20 μm laminated through an acrylic adhesive layer having a thickness of 3 μm. It was.
The xylene solution of the release agent 3 was prepared with toluene to an active ingredient concentration of 0.5% by mass, and this was used as the release agent coating solution. The release agent coating solution was applied to the surface of the support on the aluminum foil side with a bar coater so that the dry mass was 0.3 g / m ^2, and dried to form a release agent layer.
Next, the surface of the flat woven fabric side of the support, a synthetic rubber-based hot-melt adhesive, and 125 g / m ² coated to form an adhesive layer by a hot melt coater, the resulting laminate Was wound with a winder with the pressure-sensitive adhesive layer side inside, to obtain a pressure-sensitive adhesive tape.

<Example 2>
An adhesive tape was prepared in the same manner as in Example 1 except that the release agent 3 was changed to the release agent 2.

<Example 3>
An adhesive tape was prepared in the same manner as in Example 1 except that the release agent 3 was changed to the release agent 4.

<Example 4>
An adhesive tape was produced in the same manner as in Example 1 except that the coating amount of the synthetic rubber-based hot melt adhesive was changed from 125 g / m ² to 70 g / m ² .

<Example 5>
An adhesive tape was produced in the same manner as in Example 1 except that the coating amount of the synthetic rubber-based hot melt adhesive was changed from 125 g / m ² to 170 g / m ² .

<Example 6>
An adhesive tape was prepared in the same manner as in Example 1 except that the coating amount (dry mass) of the release agent coating solution was changed from 0.3 g / m ² to 0.12 g / m ² .

<Example 7>
An adhesive tape was prepared in the same manner as in Example 1 except that the coating amount (dry mass) of the release agent coating solution was changed from 0.3 g / m ² to 0.95 g / m ² .

<Comparative Example 1>
An adhesive tape was prepared in the same manner as in Example 1 except that the release agent 3 was changed to the release agent 1.

<Comparative example 2>
An adhesive tape was prepared in the same manner as in Example 1 except that the release agent 3 was changed to the release agent 5.

About each adhesive tape obtained in Examples 1-7 and Comparative Examples 1-2, the chemical modification by trifluoroacetic anhydride is performed in the above procedure, and the elemental composition on the surface of the release agent layer after the chemical modification is measured by ESCA. And F content rate was calculated | required. The results are shown in Table 2.
Separately, for each adhesive tape, its own back peel force (a) (tensile speed 3 m / min), its own back peel force (b) (tensile speed 30 m / min), stainless steel plate (SUS) adhesive force, its own back surface Holding power was measured. Moreover, the value of (a) / (b) was computed from the measurement result. The results are shown in Table 2.
Further, the self-back edge lift was measured for each adhesive tape. The results are shown in Table 3.

As shown in the above results, the pressure-sensitive adhesive tapes of Examples 1 to 7 each had a sufficient self-back surface peeling force (a) at a low tensile speed of 2.0 N / 10 mm or more. In addition, the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer due to the transfer of the release agent layer or the like was 6.5 N / 10 mm or more after pressure-bonding in an environment of 23 ° C. and 50% RH and left for 30 minutes. It is thought that the decrease of the is also suppressed. From these things, it is thought that the adhesive tapes of Examples 1 to 7 are unlikely to float or peel off when attached to an adherend such as a heat insulating material or the back surface of the adhesive tape. Actually, the self-retaining force was 0 mm in all cases. Moreover, even in the self-back edge lift for evaluation of practicality, Examples 1 to 7 were not lifted off and the seam was not opened, and good results were obtained.
In addition, these adhesive tapes had a back surface peeling force (a) of 8 N / 10 mm or less and (a) / (b) of 1.0 or more. That is, the back surface peeling force (b) at a high tensile speed was sufficiently low. From this, it was confirmed that these pressure-sensitive adhesive tapes had a light rewinding force and excellent workability.
Thus, although the adhesive tape of Examples 1-7 has high adhesive force, the own back surface peeling force (a) at a low speed is suppressed to 8 N / 10 mm or less, and (a) / (b) Since it was ≧ 1.0, it was possible to easily rewind and excellent workability at the time of actual use (pulling speed of 30 m / min.).
On the other hand, the pressure-sensitive adhesive tape of Comparative Example 1 having an F content of 6.7 atomic% had a self-rear surface peeling force (a) exceeding 8 N / 10 mm at a low tensile speed. Such an adhesive tape is too heavy when starting to rewind the tape and is difficult to peel off, and further, it is heavy even at high-speed peeling, so workability is poor.
The adhesive tape of Comparative Example 2 having an F content of 0.4 atomic% was subjected to pressure bonding in an environment of 23 ° C. and 50% RH, and the adhesive strength against SUS after standing for 30 minutes similarly formed an adhesive layer. It is lower than Examples 1-3 and 6-7, and it is thought that the adhesive force of the pressure-sensitive adhesive layer was reduced due to the transfer of the release agent layer or the like. Such an adhesive tape tends to float or peel off when it is applied to a heat insulating material, its back surface, or an adherend. In fact, in the evaluation of the self-retaining force, it dropped from the release agent surface after 49 minutes. Furthermore, in Comparative Example 2, since the release agent was poorly adhered, the transfer of the release agent to the pressure-sensitive adhesive layer occurred. In particular, the test pieces were peeled off at 23 ° C. and 40 ° C., resulting in practical problems.

  DESCRIPTION OF SYMBOLS 1 Support body, 2 Release agent layer, 3 Adhesive layer, 10 Adhesive tape, 11 Glass fiber woven fabric layer, 12 Adhesive layer, 13 Aluminum foil layer

Claims (5)

A support, a release agent layer, and an adhesive layer;
The support is formed by laminating an aluminum foil layer via an adhesive layer on one side of a glass fiber woven fabric layer,
The release agent layer is laminated on the surface of the support on the aluminum foil layer side, the pressure-sensitive adhesive layer is laminated on the surface of the glass fiber woven fabric layer side,
The release agent layer contains a release agent comprising a long-chain alkyl group-containing compound having a hydroxyl group,
When the surface of the release agent layer is brought into contact with trifluoroacetic anhydride in the gas phase to chemically modify the hydroxyl group present on the surface and the elemental analysis by ESCA is performed, the F content is 0.5 atomic% or more 6. Adhesive tape that is 6.0 atomic% or less.   The pressure-sensitive adhesive tape according to claim 1, wherein the long-chain alkyl group-containing compound having a hydroxyl group has a melting point of 88 ° C or higher and 105 ° C or lower.   The self-back surface peeling force (a) at a tensile speed of 3 m / min is 8 N / 10 mm or less, and the self-back surface peeling force (a) and the self-back surface peeling force (b) at a tensile speed of 30 m / min are ( The pressure-sensitive adhesive tape according to claim 1 or 2, wherein a) / (b) ≥1.0.   The adhesive tape as described in any one of Claims 1-3 whose adhesive which comprises the said adhesive layer is a hot-melt-type adhesive. The pressure-sensitive adhesive tape according to claim 1, wherein a mass per unit area of the pressure-sensitive adhesive layer is 60 g / m ² or more and 180 g / m ² or less.

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