JPH11209710A - Double coated adhesive tape or sheet and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare the subject tape or sheet enabling the decrease of the thickness of the tape, and having good punching property and workability by placing a first adhesive-agent layer and a second adhesive-agent layer on each of the obverse and the reverse of a base material comprising a specific resin. SOLUTION: This tape or sheet is obtained by placing first adhesive-agent layer and a second adhesive-agent layer on each of the obverse and the reverse of a base material comprising a resin selected from natural rubbers, synthetic rubbers, acrylic resins, olefin resins, silicone resins and the like, and having a Young's modulus of preferably 0-300%, more preferably 0-120%, further preferably 0-80%. The ratio of the Young's modulus of the resin which forms the base material to the Young's modulus of the resin which forms the first and the second adhesive-agent layers is preferably (1:1) to (1:20), more preferably (1:1) to (1:10), further preferably (1:2) to (1:5). The first and the second adhesive- agent layers are formed by using a resin usually used for an adhesive agent, and optionally an adhesivity-imparting agent, a softener, a filler, a crosslinking agent or the like is compounded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a double-sided pressure-sensitive adhesive tape or sheet, particularly a double-sided pressure-sensitive adhesive tape or sheet without a substrate, and a method for producing the same.

[0002]

2. Description of the Related Art Heretofore, as a double-sided pressure-sensitive adhesive tape, a tape formed by forming a pressure-sensitive adhesive layer on both sides of a base material such as a polyethylene film or a nonwoven fabric has been known. It is used for various purposes such as fixing interior materials of vehicles. Such a double-sided pressure-sensitive adhesive tape has problems that the tape thickness cannot be reduced and the punching property is poor. In addition, since the mechanical properties of the base material and the pressure-sensitive adhesive layer are significantly different, it is difficult to uniformly stretch and adhere to the shape of the adherend, and only the pressure-sensitive adhesive layer is cut when the tape is cut. There was also a problem that the workability was poor, for example, the pressure-sensitive adhesive layer was distorted due to the burden. In order to solve such a problem, a double-sided pressure-sensitive adhesive tape without a base material, that is, including only a pressure-sensitive adhesive layer, has been proposed.

For example, JP-A-63-268784 discloses a photo-crosslinkable pressure-sensitive adhesive layer containing an acrylic copolymer as a component.
There is disclosed a base-less pressure-sensitive adhesive tape having a difference in adhesive strength based on a difference in the degree of crosslinking on the front and back surfaces of the pressure-sensitive adhesive layer.

[0004]

However, the above-mentioned substrate-less double-sided pressure-sensitive adhesive tape has the following problems.

(1) A double-sided pressure-sensitive adhesive tape without a base material is liable to cause blocking, so that the tackiness cannot be increased.

(2) If there is no base material, the pressure-sensitive adhesive may be insufficiently retained, and the pressure-sensitive adhesive layer may be dragged by the slitter during slitting. In addition, the adhesive layer may protrude during storage. If the pressure-sensitive adhesive sticks out in this way, blocking occurs when the pressure-sensitive adhesive tape is rewound, making the tape unusable. This burr is particularly problematic when precision is required, such as in the bonding of electronic parts. That is, the presence of the burrs causes the bonded electronic components to float, causing a problem that the product is defective.

(3) In the case of a pressure-sensitive adhesive tape comprising only a pressure-sensitive adhesive layer, it is difficult to change the adhesiveness between the front and back surfaces of the tape. In the double-sided pressure-sensitive adhesive tape disclosed in JP-A-63-268784, an attempt has been made to change the adhesiveness between the front and back surfaces. Therefore, a sufficient difference in adhesiveness is not always obtained, and problems such as blocking and protrusion of the adhesive remain as described above.

(4) Double-sided adhesive tapes are made of metal, glass,
It is widely used to fix two kinds of materials with different properties such as plastic resin and rubber. However, the conventional baseless double-sided pressure-sensitive adhesive tape has only one adhesive layer, so the type of material that can be fixed is There is the problem of being limited.

Accordingly, the present invention can reduce the thickness of the tape, has good punching properties and workability, and does not cause problems such as blocking or sticking out of the pressure-sensitive adhesive. It is an object of the present invention to provide a double-sided pressure-sensitive adhesive tape or sheet capable of easily changing the pressure-sensitive adhesiveness of the same and a method for producing the same.

[0010]

In order to achieve the above object, the present invention provides a natural or synthetic rubber, an acrylic resin,
A substrate formed of a resin selected from an olefin resin, a silicone resin and a urethane resin, and both surfaces comprising a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer provided on the front and back surfaces of the substrate, respectively. Provide an adhesive tape or sheet.

Further, the present invention provides a method wherein the Young's modulus is 0 to 300%.
And a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer provided on the front and back surfaces of the substrate, respectively.

Further, the present invention provides a method of forming a first pressure-sensitive adhesive layer on a release material, and forming a first pressure-sensitive adhesive layer on the first pressure-sensitive adhesive layer from natural or synthetic rubber, acrylic resin, olefin resin, silicone resin and urethane resin. Provided is a method for producing a double-sided pressure-sensitive adhesive tape or sheet, comprising laminating a base film formed of a selected resin and forming a second pressure-sensitive adhesive layer on the base film.

Further, according to the present invention, a first pressure-sensitive adhesive layer is formed on a release material, and a Young's modulus of 0 to 3 is formed on the first pressure-sensitive adhesive layer.
The present invention provides a method for producing a double-sided pressure-sensitive adhesive tape or sheet, comprising laminating a base film formed of a resin of 100% and forming a second pressure-sensitive adhesive layer on the base film.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION (Substrate) The substrate may be formed by film-forming a resin usually used as an adhesive to a desired thickness. For example, formed by the following resins: natural rubber; styrene-butadiene-based, polyisobutylene-based, isoprene-based synthetic rubber; acrylic resin, for example, polymer of 2-ethylhexyl acrylate, butyl acrylate, ethyl acrylate; olefin resin For example, polystyrene-ethylene / butylene copolymer, polyethylene, polystyrene-ethylene-propylene copolymer; silicone resin, for example, vinyl polydimethylsiloxane copolymer, vinyl trichlorosilane-alkoxysilane copolymer; urethane resin For example,
What is obtained by the reaction of polyisocyanate with the following polyols: polyester resins, saturated polyesters, unsaturated polyesters such as polyester polyols, polyester polyols and polylactone polyols.

[0015] The substrate is preferably formed of an acrylic resin. Acrylic resins can be obtained, for example, by polymerizing one or more of the following monomers by solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, etc .: acrylic acid, methacrylic acid, alkyl groups Unsubstituted or substituted alkyl acrylate or alkyl methacrylate having 1 to 20 carbon atoms (e.g., methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, Isononyl acrylate, methyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, dimethylaminoethyl methacrylate), vinyl acetate, acrylonitrile, acrylamide, styrene,
Vinylidene chloride, itaconic acid, acrylamide, methylolacrylamide, glycidyl methacrylate, maleic anhydride, and the like.

Preferably, the substrate is formed of an aqueous acrylic emulsion resin.

The Young's modulus of the substrate is preferably from 0 to 300.
%, More preferably 0 to 120%, particularly 0 to 80%. In the present specification, “Young's modulus” refers to JIS Z
[0237] This is "growth" described in 1991-.

The Young's modulus of the resin forming the base material is similar to the Young's modulus of the resin forming the pressure-sensitive adhesive layer. For example, the Young's modulus of the resin forming the base material and the first and second adhesives The ratio of the resin forming the agent layer to the Young's modulus is 1: 1 to 1: 2.
0, preferably 1: 1 to 1:10, especially 1: 2 to 1: 5
It is preferred that

Preferably, the resin forming the substrate is formed of a monomer having the same composition as the resin forming the first pressure-sensitive adhesive layer and / or the resin forming the second pressure-sensitive adhesive layer. More preferably, the base material has the same composition as the resin forming the first pressure-sensitive adhesive layer and / or the resin forming the second pressure-sensitive adhesive layer, and has a larger molecular weight than the resin forming the pressure-sensitive adhesive. Consists of The molecular weight of the substrate is, for example, 2,000 to 1,500,000, preferably 5,000 to 300,000.
Especially 200,000 to 500,000.

Preferably, the resin forming the substrate is formed of a monomer having the same composition as the resin forming the first pressure-sensitive adhesive layer and / or the resin forming the second pressure-sensitive adhesive layer. It is a resin with a higher degree of crosslinking than the resin forming the adhesive. Crosslinking of the base resin is performed by blending an appropriate crosslinking agent during polymerization. As crosslinking agents, for example, the following can be used: epoxy resins, isocyanates, melamine resins, urea resins, etherified amino resins, metal chelates.

Further, it is preferable that the base material is formed of a resin having a Tg value close to the Tg (glass transition point) of the resin forming the first and / or second pressure-sensitive adhesive. For example, the Tg of the resin forming the first and / or second adhesive
The difference between Tg of the resin forming the base material is 1 to 30, preferably 1 to 10, particularly 1 to 5.

The thickness of the base material varies depending on the use and the base material and adhesive material used, but is preferably from 1 to 15
0 μm, more preferably 10 to 50 μm.

The base material is obtained by mixing one or more kinds of raw material monomers, and additives such as a crosslinking agent, if desired, and polymerizing them by solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, or the like. It can be used as a raw material and can be formed by an extrusion method such as a T-die method, an inflation method, or a casting method.

An example of the composition of the base material is shown below:

[0025]

[Table 1]

Film formation by the T-die method is carried out by putting a raw material into an extruder, heating and melting, extruding from a T-die, stretching and cooling.

The film formation by the inflation method is carried out by extruding a raw material heated and melted in an extruder from an inflation die, expanding the material by air pressure, and cooling the air.

Film formation by casting is carried out by dissolving the raw materials in a solvent, filtering, casting, and drying.

The base material may contain additives such as an antioxidant and a conductive material described later.

(Pressure-sensitive adhesive layer) The first and second pressure-sensitive adhesive layers are formed of a resin usually used for a pressure-sensitive adhesive, and if desired, a tackifier, a softener, a filler, an antioxidant, and a crosslinking agent. And the like.

The resin may be, for example, a natural rubber; a synthetic rubber such as a styrene-butadiene-based, polyisobutylene-based or isoprene-based resin; an acrylic resin such as methyl (meth) acrylate, ethyl (methyl) acrylate; Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; olefin resin, for example, polyethylene, polypropylene; silicone resin,
For example, siloxane trichlorosilane, alkoxysilane; urethane resin, for example, polyester polyol,
Polycarbonate, polyester polyol, polyalkylene polyol and the like.

Preferably, the first and / or second pressure-sensitive adhesive layers are formed of an acrylic resin. The acrylic resin may be obtained by polymerizing one or more of the monomers listed above for the base material by solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization, or the like.

Preferably, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are formed of resins having different adhesive strengths. For example, the first pressure-sensitive adhesive layer is formed of an acrylic resin, and the second pressure-sensitive adhesive layer is formed of a synthetic rubber.

The thickness of the pressure-sensitive adhesive layer is preferably 5 to 5 on one side.
It is 100 μm, more preferably 10 to 50 μm.

Tackifiers can be, for example: rosins (eg rosin, gum rosin, modified rosins, rosin esters); terpene phenolic resins; terpene resins; synthetic petroleum resins (eg isoprene, cyclopentadiene, 1, 3-pentadiene, 1-pentene copolymer, 2-pentene, dicyclopentadiene copolymer, 1,3-pentadiene-based resin, indene,
A copolymer of styrene, methylindene and α-methylstyrene); a phenol resin; a xylene resin; an alicyclic petroleum resin; a coumarone indene resin; a styrene resin;

The crosslinking agent may be selected from those listed above for the substrate.

When conductivity is required, zinc oxide,
A conductive material such as tin oxide can be dispersed in the pressure-sensitive adhesive layer and the substrate. The particle size of the conductive material is preferably 0.01 to 30 μm.
m, more preferably 0.01 to 0.02 μm. The amount of the conductive material is 20 to each of the amount of the base material and the amount of the adhesive.
Preferably it is 40% by weight.

(Method for producing double-sided pressure-sensitive adhesive tape) The double-sided pressure-sensitive adhesive tape of the present invention is produced, for example, by the following method.

An adhesive or a solution thereof is coated on a release paper by a kiss roll coater, a gravure coater, a knife coater, a reverse roll coater, or the like to have a dry thickness of 10 to 10.
It is applied to a thickness of 100 μm and dried at a temperature of 60 to 120 ° C.

The base material is laminated thereon, dried at a temperature of 60 to 120 ° C., and rolled up.

Further, while rewinding the adhesive, the pressure-sensitive adhesive or a solution thereof is coated on the substrate by a kiss roll coater, gravure coater, knife coater, reverse roll coater or the like so that the thickness when dried becomes 10 to 100 μm. Apply, dry at a temperature of 60-120 ° C and roll up.
The total thickness of the double-sided pressure-sensitive adhesive tape or sheet of the present invention (substrate + first pressure-sensitive adhesive layer + second pressure-sensitive adhesive layer) is preferably 1
It is from 0 to 200 μm, especially from 40 to 160 μm.

The double-sided pressure-sensitive adhesive tape or sheet of the present invention may be in the form of a rolled-up tape or sheet with one or both sides covered with a release material. In this case, there is a step of slitting to a desired tape or sheet width following the winding step.

The double-sided pressure-sensitive adhesive tape or sheet of the present invention may be in the form of a sheet having both sides covered with a release material. In this case, following the above-described winding step, cutting into an arbitrary and appropriate shape or size is performed. The formed sheet can be further cut or punched into a desired shape before use.

As the release material, use is made of a material obtained by anchor-coating a paper with a resin, a resin sheet having a high releasability made of polyethylene, polypropylene or the like, and a release agent such as a silicone-based material applied to the surface as desired. Is done.

[0045]

EXAMPLES Example 1: (Production of base material) Acrylic emulsion resin (methacrylic acid ester; molecular weight: 600,000, manufactured by DM772 Hoechst Synthesis Co., Ltd.), casting apparatus (OP using a comma coater)
P film (25 μm) and dried at 100 ° C. to form a substrate having a thickness of 10 μm.

The Young's modulus of the obtained substrate was 180.
%, Tg was 180 ° C.

[Preparation of Pressure-Sensitive Adhesive Solution A] Acrylic resin: pressure-sensitive adhesive solution A was prepared by using an acrylic acid acrylate-vinyl acetate copolymer pressure-sensitive adhesive, for example, SK Dyne 1717 manufactured by Soken Chemicals.

[0048]

[Table 2]

Were mixed to prepare a pressure-sensitive adhesive solution B.

(Production of double-sided adhesive tape or sheet)
The pressure-sensitive adhesive solution A prepared as described above was applied to a release paper by a gravure coater in an amount such that the thickness when dried was 30 μm, dried at 100 ° C., and wound up.

While unwinding, the substrate produced as described above was laminated on the pressure-sensitive adhesive layer, dried at 100 ° C., and wound up.

While rewinding, the adhesive solution B was dried on the substrate formed as described above to a thickness of 30 μm.
m with a gravure coater in an amount such that
Dried at 00 ° C and rolled up.

The obtained double-sided pressure-sensitive adhesive tape was slit to a width of 25 mm by a slitter. No protrusion of the adhesive was observed at the time of slitting.

The pressure-sensitive adhesive layers (A) and (B) formed as described above each have a Young's modulus of 270%,
240%.

When the sticking operation was performed using the double-sided pressure-sensitive adhesive tape or sheet produced as described above, the positioning could be easily performed and the sticking could be performed without blocking.

When the double-sided pressure-sensitive adhesive tape or sheet produced as described above was stored for 7 days in an environment of 80 ° C. and 80% humidity, no defect such as protrusion of the pressure-sensitive adhesive was observed.

[0057]

According to the double-sided pressure-sensitive adhesive tape or sheet of the present invention, the base material is formed of a resin having the same properties as the resin of the pressure-sensitive adhesive layer. The workability is good, for example, it can be stuck easily regardless of the shape, and there is no skew when cutting. Further, it is easy to disperse a functional material such as a conductive material into the base material. For this reason, the thickness and material can be freely designed according to the application such as industrial or medical use, and the applicable range of the double-sided pressure-sensitive adhesive tape or sheet can be expanded.
In addition, there is no problem such as blocking or sticking out of the pressure-sensitive adhesive which is observed in a double-sided pressure-sensitive adhesive tape or sheet without a base material. Furthermore, since the pressure-sensitive adhesive layers having different tackiness can be formed on the front and back surfaces of the tape or the sheet, the surface on the side having a weak adhesive force is stuck to or adhered to the adherend when sticking. Thereby, alignment can be easily performed.

Claims (11)

[Claims] 1. A substrate formed of a resin selected from natural or synthetic rubber, acrylic resin, olefin resin, silicone resin and urethane resin, and first adhesives provided on the front and back surfaces of the substrate, respectively. A double-sided pressure-sensitive adhesive tape or sheet comprising a pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer. 2. A base material formed of a resin having a Young's modulus of 0 to 300%, and a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer provided on the front and back surfaces of the base material, respectively. Double-sided adhesive tape or sheet. 3. A base material formed of a resin having a Young's modulus of 0 to 120%, and a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer provided on the front and back surfaces of the base material, respectively. Double-sided adhesive tape or sheet. 4. A base material formed of a resin having a Young's modulus of 0 to 80%, and a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer provided on the front and back surfaces of the base material, respectively. Double-sided adhesive tape or sheet. 5. The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are each independently formed of a resin selected from natural or synthetic rubber, acrylic resin, olefin resin, silicone resin and urethane resin. The double-sided pressure-sensitive adhesive tape or sheet according to any one of claims 1 to 4, characterized in that: 6. The method according to claim 1, wherein the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are formed of resins having different adhesive strengths. The double-sided adhesive tape or sheet as described. 7. The ratio of the Young's modulus of the resin forming the base material to the resin forming the first and / or second pressure-sensitive adhesive layers is from 1: 1 to 1:20. The double-sided pressure-sensitive adhesive tape or sheet according to any one of claims 1 to 6, characterized in that: 8. The double-sided pressure-sensitive adhesive tape or sheet according to claim 1, wherein the substrate is formed of an acrylic resin. 9. The double-sided pressure-sensitive adhesive tape or sheet according to claim 1, wherein the substrate has a thickness of 1 to 150 μm. 10. A first pressure-sensitive adhesive layer is formed on a release material, and a resin selected from natural or synthetic rubber, acrylic resin, olefin resin, silicone resin and urethane resin is formed on the first pressure-sensitive adhesive layer. A method for producing a double-sided pressure-sensitive adhesive tape or sheet, comprising: laminating a base film formed by the method described above, and forming a second pressure-sensitive adhesive layer on the base film. 11. A first pressure-sensitive adhesive layer is formed on a release material, and a base film formed of a resin having a Young's modulus of 0 to 300% is laminated on the first pressure-sensitive adhesive layer, A method for producing a double-sided pressure-sensitive adhesive tape or sheet, comprising forming a second pressure-sensitive adhesive layer on the substrate film.