JP2015048451A - Adhesive tape roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive tape roll without collapse of coil, unwinding and base material damage when the cushioning adhesive tape is wound into a roll.SOLUTION: Adhesive tape that first and second polyethylene film laminates 31 and 32 are laminated on both sides of a base material 21 consisting of a polyethylene foam sheet, and adhesive 4 which is composed primarily of (meth)acrylate and added crosslinking agent in modacrylic copolymer copolymerized monomer component having an appointed functional group is put on a second film laminate 32, is wound and shaped into a roll.

Description

  The present invention relates to a pressure-sensitive adhesive tape roll obtained by winding a pressure-sensitive adhesive tape formed by applying a pressure-sensitive adhesive on one surface of a base material made of a foam sheet into a roll shape. The present invention relates to a technique for controlling the balance between the strength of a base material and the adhesive force of an adhesive, which prevents wrinkling and makes the force to rewind the tape constant (prevents rise due to aging or heating).

  As a heat insulating sheet for the purpose of dew condensation in winter and heat insulation in summer, for example, a heat insulating sheet of Patent Document 1 is provided. This heat insulating sheet is an adhesive tape in which an adhesive is applied to almost one surface of a base material made of a foam sheet. For example, the heat insulating sheet is attached along an aluminum sash frame to conduct heat conduction therefrom. Intended to suppress. In addition, this type of adhesive tape is also used as a cushion tape to prevent damage to the wall surface during moving.

  On the other hand, an adhesive tape for cleaning using an adhesive tape based on the same type of foamed sheet is also provided. For example, as described in Patent Document 2, this cleaning adhesive tape is wound in a roll shape so that the adhesive surface faces the front side, and makes use of the cushioning properties of the base material on the surface to be cleaned. By rolling so as to press the adhesive surface, even relatively coarse dust can be captured.

  However, both have the following problems. That is, this adhesive tape is usually shipped in the state of being wound in a roll, and when used as a heat insulating sheet, the user draws out (rewinds) a necessary length, and cuts and uses it. Moreover, when using as a sheet | seat for cleaning, it peels and uses the adhesive tape of the outermost layer.

  Although it is necessary to increase the thickness of the base material in order to improve the heat insulating property and cushioning property, if the thickness of the foam sheet is increased, the rigidity is inevitably increased. Therefore, if the rigidity of the base material is greater than the adhesive strength, a phenomenon may occur in which the winding is loosened after being wound into a roll shape and the tape tip is naturally swollen.

  Conversely, in order to prevent the phenomenon described above from occurring, if the adhesive strength is increased too much so that the rigidity of the substrate <the adhesive strength of the adhesive, the adhesive will stick too tightly between adjacent substrates. When peeled off, the adhesive may transfer, or the tape may not be rewound and the substrate may be destroyed.

JP 2001-55871 A JP 2003-153846 A

  Therefore, the object of the present invention is to prevent the roll-up and unwinding of the adhesive tape having cushioning properties, and to prevent the adhesive from sticking and the base material from being destroyed. Another object of the present invention is to provide an adhesive tape roll in which the balance between the rigidity of the substrate and the adhesive force of the adhesive is controlled.

  In order to solve the above-described problems, the present invention has several features described below. That is, in the pressure-sensitive adhesive tape roll formed by winding a pressure-sensitive adhesive tape in which the first laminate film is bonded to one surface of the foam sheet and the pressure-sensitive adhesive is applied to the other surface, the foam sheet and the above Both the first laminate films are made of polyethylene, and the above-mentioned pressure-sensitive adhesive is obtained by adding a crosslinking agent to an acrylic copolymer having (meth) acrylate as a main component and copolymerizing a monomer component having a predetermined functional group. It is characterized by consisting of. In the present specification, “(meth) acrylate” is a generic term for acrylate and methacrylate.

  Further, the other surface of the foam sheet is characterized in that a second laminate film is bonded and the pressure-sensitive adhesive is applied to the surface of the second laminate film.

  Further, the surface of the second laminate film is subjected to a corona discharge treatment for improving the anchoring property of the adhesive.

  As a preferred embodiment, the pressure-sensitive adhesive polymer has a weight average molecular weight of 1,000,000 or less, more preferably a weight average molecular weight of 500,000 to 800,000.

  According to the present invention, a first laminated film made of polyethylene is integrally bonded to one surface of a foam sheet made of polyethylene, and an adhesive tape is applied with an acrylic pressure-sensitive adhesive applied to the other surface. By winding in a roll shape, the acrylic pressure-sensitive adhesive and the first laminated film made of polyethylene have good affinity when wound in a roll shape, and therefore do not collapse or unwind.

  Furthermore, the other surface of the foam sheet is bonded to the second laminate film, and an adhesive is applied to the surface of the second laminate film, whereby the foam sheet can be strengthened and the base material is destroyed. Can be prevented.

  By applying corona discharge treatment to the surface of the second laminate film, the polymer surface of the surface of the second laminate film is modified, and the modified functional group and the functional group of the adhesive are chemically bonded. By this, the wettability and anchoring property of the adhesive are further improved.

  As a preferred embodiment, the pressure-sensitive adhesive can be adjusted to have a weight average molecular weight of 1,000,000 or less, more preferably about 500,000 to 800,000, whereby a pressure-sensitive adhesive having low polymer condensability and low fluidity can be constituted. That is, the fact that the condensability is small and the fluidity is low means that the adhesive force is prevented from increasing after being attached to the adherend, and that the adhesive does not break when peeled off from the adherend. Contamination can be prevented.

The perspective view which shows the adhesive tape roll which concerns on one Embodiment of this invention. The principal part sectional drawing of the adhesive tape of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

  As shown in FIG. 1, the pressure-sensitive adhesive tape roll 1 is formed by winding a belt-shaped pressure-sensitive adhesive tape 2 coated with a pressure-sensitive adhesive on one surface along a core 3 in a roll shape. In this embodiment, the pressure-sensitive adhesive tape roll 2 is wound so that the pressure-sensitive adhesive surface 22 (see FIG. 2) faces inward for the heat insulating sheet. When used as a cleaning sheet, the adhesive surface 22 is wound so that the outer side faces. The winding direction may be arbitrarily changed according to the application of the adhesive tape 2.

  Referring also to FIG. 2, the adhesive tape 2 has a base material 21 made of a foam sheet, and the first laminate film 31 is integrated with one surface 21 a (upper surface in FIG. 2) of the base material 21. The second laminated film 32 is integrally bonded to the other surface 21b (the lower surface in FIG. 2). The pressure-sensitive adhesive 4 is applied to the surface of the second laminate film 32.

  The base material 21 is made of a closed cell foam sheet made of polyethylene, and in this embodiment, a thickness of 2.0 mm is used. As the polyethylene used for the substrate 21, any of low density polyethylene (LDPE), medium density polyethylene (MDPE), and high density polyethylene (HDPE) may be selected.

  Both the first laminate film 31 and the second laminate film 32 are made of polyethylene. In this embodiment, each of the laminate films 31 and 32 has a thickness of 30 μm.

As polyethylene used for the substrate 21, the first laminate film 31, and the second laminate film 32, low density polyethylene (LDPE: 0.91 to 0.93 g / cm ³ ), medium density polyethylene (MDPE: 0.93). 0.942 g / cm ³ ) or high-density polyethylene (HDPE: 0.942 g / cm ³ or more) may be arbitrarily selected according to specifications.

  The base material 21 and the laminated films 31 and 32 may be integrally bonded by heat sealing, or may be bonded integrally by an adhesive or an adhesive.

  One surface 321 (the lower surface in FIG. 2) of the second laminate film 32 is provided with a corona discharge treatment surface for improving the wettability and anchoring property of the adhesive 4.

  By subjecting the surface of the second laminate film 32 to corona discharge treatment, the main chain and side chain of the polymer on the surface of the second laminate film 32 are cut off, and the polymer surface is in a chemically radical state. There, oxygen radicals in the gas phase and the ozone layer recombine, whereby polar functional groups such as hydroxyl groups and carbonyl groups are introduced to impart hydrophilicity. By applying the hydrophobic adhesive 4 there, the wettability and anchoring property of the adhesive are improved. The treatment conditions for the corona discharge treatment can be arbitrarily changed according to the specifications.

  The pressure-sensitive adhesive 4 is applied over the entire surface (the lower surface side in FIG. 2) of the second laminate film 32, so that the pressure-sensitive adhesive surface 22 has adhesiveness on the other surface 21 b of the pressure-sensitive adhesive tape 2. It is formed.

  In the present invention, the pressure-sensitive adhesive 4 is an acrylic pressure-sensitive adhesive in which a cross-linking agent is added to an acrylic copolymer (acrylic polymer) having a (meth) acrylate as a main component and a monomer component having a predetermined functional group. Become.

  Examples of the pressure sensitive adhesive include rubber pressure sensitive adhesive, acrylic pressure sensitive adhesive, urethane pressure sensitive adhesive, and silicone pressure sensitive adhesive. From the viewpoint of adhesive performance and cost, rubber adhesives or acrylic adhesives can be preferably employed. Among these, an acrylic pressure-sensitive adhesive is particularly preferable.

  As the acrylic pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive containing an acrylic polymer is preferably used as the base polymer. The acrylic polymer can be synthesized from a monomer raw material containing an alkyl (meth) acrylate having an alkyl group as a main monomer. Here, the main monomer refers to a monomer component occupying 50% by mass or more of the total monomer components. In the present specification, “(meth) acrylate” means acrylate and methacrylate comprehensively.

  As the alkyl (meth) acrylate, for example, a compound represented by the formula: CH2 = CR1COOR2; can be preferably used. Here, R1 in the above formula is a hydrogen atom or a methyl group. R2 is an alkyl group having 1 to 20 carbon atoms (hereinafter, such a range of the number of carbon atoms may be represented as “C1-20”).

  From the viewpoint of the storage elastic modulus of the pressure-sensitive adhesive, an alkyl (meth) acrylate having a C1-14 (for example, C1-10) alkyl group is preferable, and an alkyl (meth) acrylate having a C4-9 alkyl group is preferable. The alkyl group may be linear or branched.

  Examples of the alkyl (meth) acrylate having a C1-20 alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, Isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) Acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate , Isodecyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, Examples include hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, and eicosyl (meth) acrylate. These alkyl (meth) acrylates can be used alone or in combination of two or more.

  A functional group-containing monomer such as a carboxyl group, a hydroxyl group, and an epoxy group is preferable because a crosslinking point can be suitably introduced into the acrylic polymer and the cohesive force of the acrylic polymer can be further increased. A carboxyl group-containing monomer or a hydroxyl group-containing monomer is more preferable. Examples of the carboxyl group-containing monomer include ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and citracone. Examples thereof include ethylenically unsaturated dicarboxylic acids such as acids. Of these, acrylic acid and / or methacrylic acid are preferable, and acrylic acid is particularly preferable.

  The acrylic copolymer preferably has a weight average molecular weight of 1,000,000 or less, more preferably adjusted to about 500,000 to 800,000. That is, if it is 1,000,000 or less (500,000 to 800,000), the influence of the adherend from the cohesiveness and fluidity, the increase in the adhesive strength after sticking, and the breakage of the adhesive when peeled off from the adherend There is no stickiness and tackiness that can prevent contamination is obtained. On the contrary, when it becomes 1 million or more, the cohesiveness and fluidity are further reduced, and the adhesive becomes hard. As a result, the adhesive strength tends to be low, and a phenomenon occurs in which the initial adhesive strength is reduced and the adhesiveness at low temperatures in winter is hindered and the tape does not adhere.

  It is preferable to mix a crosslinking agent in the pressure-sensitive adhesive composition. For example, preferable examples of the crosslinking agent include organic metal salts such as zinc stearate and barium stearate, epoxy crosslinking agents, isocyanate crosslinking agents and the like. You may use an oxazoline type crosslinking agent, an aziridine type crosslinking agent, a metal chelate type crosslinking agent, and a melamine type crosslinking agent. These crosslinking agents may be used alone or in combination of two or more. Of these, epoxy crosslinking agents and isocyanate crosslinking agents can be suitably cross-linked with carboxyl groups, have good operability (typically light release properties), and are excellent in acid resistance. Is preferred, and an isocyanate-based crosslinking agent is particularly preferred. The amount of the crosslinking agent is not particularly limited, but 0.01 to 10 parts by mass (for example, 0) with respect to 100 parts by mass of the base polymer (for example, acrylic polymer) in order to achieve the above-mentioned preferable numerical range of adhesive strength. 0.05 to 5 parts by mass, typically 0.1 to 5 parts by mass).

  The adhesive 4 further contains 0.15 to 0.35 parts by weight of a fatty acid amide (such as ethylene bis stearic acid amide) in order to suppress an increase in adhesive force (adhesive force) and unwinding force to the adherend. Preferably it is. In this embodiment, the adherend is blended under the conditions set with the stainless steel plate (SUS304), but the blending ratio is arbitrarily selected depending on the condition of the adherend, such as a flooring floor, a carpet, and a stainless sash frame. good.

  The pressure-sensitive adhesive 4 is applied to the surface of the second laminate film 32 so as to have a uniform thickness. About the application method of the adhesive 4, since it is arbitrary matters in this invention, the description is abbreviate | omitted.

  Next, specific examples of the present invention will be examined together with comparative examples.

[Production of tape substrate]
Prepare a base material made of polyethylene foam (length 2m x width 25mm x thickness 2mm), and a polyethylene film (thickness 30μm) is integrally bonded to one surface by thermal lamination to produce a tape base material. did.

  At that time, as a polyethylene film, a low density type (“Novatec LF128” manufactured by Nippon Polyethylene Co., Ltd.), a medium density type (“Novatech HF560” manufactured by Nippon Polyethylene Co., Ltd.) and a high density type (“NEO-ZEX3510F manufactured by Prime Polymer Co., Ltd.). )) Were prepared, and a tape base material was prepared for each type.

[Production of pressure-sensitive adhesive of Example 1]
First, as an acrylic copolymer, 100 parts by weight of butyl (meth) acrylate, 2 parts by weight of acrylic acid as a functional group-containing monomer, 0.2 parts by weight of BPO (benzoyl peroxide) as a polymerization initiator, and as a solvent 80 parts by weight of toluene was blended. To 100 parts by weight of this acrylic copolymer, 2 parts by weight of an isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) was added as a cross-linking agent to prepare the pressure-sensitive adhesive of Example 1.

[Production of pressure-sensitive adhesive of Example 2]
As an acrylic copolymer, 92 parts by weight of 2-ethylhexyl acrylate, 8 parts by weight of acrylic acid as a functional group-containing monomer, 0.3 parts by weight of acrylic acid as a polymerization initiator, and 80 parts by weight of toluene as a solvent were blended. . Next, 2 parts by weight of an isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent was added to 100 parts by weight of this acrylic copolymer to prepare a pressure-sensitive adhesive of Example 2.

[Production of pressure-sensitive adhesive of Comparative Example 1]
Furthermore, as Comparative Example 1, 2 parts by weight of an isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent was added as a crosslinking agent to 100 parts by weight of the copolymer of Embodiment 1 described above, and an adhesive. As an imparting resin, 10 parts by weight of terpene phenol resin (“YS Polystar T115” manufactured by Yasuhara Chemical Co., Ltd.) was blended to obtain an adhesive.

[Production of pressure-sensitive adhesive of Comparative Example 2]
Further, as Comparative Examples 1 and 2, 2 parts by weight of an isocyanate compound (“Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd.) as a crosslinking agent was added as a crosslinking agent to 100 parts by weight of the copolymer of Embodiment 2 above. A terpene phenol resin (“YS Polystar T115” manufactured by Yasuhara Chemical Co., Ltd.) as an adhesive-applying resin was blended in an amount of 10 parts by weight to obtain an adhesive.

Thereafter, the pressure-sensitive adhesives of Examples 1 and 2 and Comparative Examples 1 and 2 were uniformly applied to the other surface of the substrate (the surface on which the laminate film was not provided) so as to have a thickness of 40 μm. After that, this adhesive tape was wound in a roll shape along a core (diameter: 30 mm).
10 samples prepared in this way for each of three types of polyethylene density (30 in total) were prepared, 5 out of 10 were used as a room temperature test to be described later, and the remaining 5 were used as a 40 ° C. constant temperature test. Using.

〔Evaluation test〕
This adhesive tape is left for 0 (immediately after production), 5, 10, 15, and 30 days at room temperature (in this example, temperature 23 ° C., humidity 64%) and 40 ° C., taken out after a predetermined number of days and wound. At that time, the adhesive was transferred to the back surface (laminate film surface) of the adhesive tape, the presence or absence of substrate destruction, and the leading edge and unwinding of the adhesive tape were confirmed.

  In the rewinding method, one end of the adhesive tape roll was held, and high-speed rewinding was performed at 30 m / min. As a result, there are three stages, with ◯ indicating that there is no unwinding or twisting, and no breakage or twisting of the base material, △ when unwinding or twisting occurs, and x when the base material breakage or twisting occurs. It was evaluated with. The results are shown below.

Example 1
〔At normal temperature〕
LDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material or shifting of the substrate.
MDPE: There is no unwinding or twisting under all conditions, and there is no breakage of the base material and no slack transfer.
HDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material and no transfer of the substrate.
[40 ° C]
LDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material or shifting of the substrate.
MDPE: Unwinding and twisting occur after 30 days.
HDPE: Unwinding and drowning after 5 days.

Example 2
〔At normal temperature〕
LDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material or shifting of the substrate.
MDPE: There is no unwinding or twisting under all conditions, and there is no breakage of the base material and no slack transfer.
HDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material and no transfer of the substrate.
[40 ° C]
LDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material or shifting of the substrate.
MDPE: Unwinding and twisting occur after 30 days.
HDPE: Unwinding and drowning after 5 days.

<< Comparative Example 1 >>
〔At normal temperature〕
LDPE: There is no unwinding or twisting under all conditions, and there is no destruction of the base material or shifting of the substrate.
MDPE: Unwinding and twisting occur after 7 days.
HDPE: Unwinding and twisting occurred after 7 days, and substrate destruction occurred after 15 days.
[40 ° C]
LDPE: Unwinding and twisting occur after 30 days.
MDPE: Unwinding and twisting occurred after 5 days, and substrate destruction occurred after 30 days.
HDPE: Substrate destruction occurred after 5 days.

<< Comparative Example 2 >>
〔At normal temperature〕
LDPE: Unwinding and twisting occur after 30 days.
MDPE: Unwinding and twisting occur after 7 days.
HDPE: Unwinding and twisting occurred after 7 days, and substrate destruction occurred after 15 days.
[40 ° C]
LDPE: Unwinding and twisting occur after 30 days.
MDPE: Unwinding and twisting occur after 7 days.
HDPE: Substrate destruction occurred after 5 days.

  The summary of Examples 1 and 2 and Comparative Examples 1 and 2 is shown in Table 1 below.

According to the above, the following knowledge was obtained.
(1) Examples 1 and 2 were almost good under all conditions regardless of the density of the polyethylene laminate film.
(2) In Comparative Examples 1 and 2, the low-density polyethylene was relatively good in the initial stage, but gradually deteriorates over time. On the other hand, high-density polyethylene causes substrate destruction from an early stage.

DESCRIPTION OF SYMBOLS 1 Adhesive tape roll 2 Adhesive tape 21 Base material 31 1st laminate film 32 2nd laminate film

Claims (4)

In the pressure-sensitive adhesive tape roll formed by winding a pressure-sensitive adhesive tape in which the first laminate film is bonded to one surface of the foam sheet and the pressure-sensitive adhesive is applied to the other surface,
The foam sheet and the first laminate film are both made of polyethylene, and the pressure-sensitive adhesive is an acrylic copolymer obtained by copolymerizing a monomer component having (meth) acrylate as a main component and having a predetermined functional group. A pressure-sensitive adhesive tape roll comprising: a cross-linking agent added thereto.   The other surface of the foam sheet is bonded with a second laminated film made of the same polyethylene as the first laminated film, and the pressure-sensitive adhesive is applied to the surface of the second laminated film. The pressure-sensitive adhesive tape roll according to claim 1.   The pressure-sensitive adhesive tape roll according to claim 2, wherein the surface of the second laminate film is subjected to a corona discharge treatment for improving the anchoring property of the pressure-sensitive adhesive.   The pressure-sensitive adhesive tape roll according to claim 1, 2 or 3, wherein the pressure-sensitive adhesive has a weight average molecular weight of 1,000,000 or less.

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