JP2001019932A - Pressure sensitive adhesive sheets for damping material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject pressure sensitive adhesive sheets for damping material improving damping performance while retaining a high adhesive strength, etc., of a pressure sensitive adhesive layer containing a specific polyester, useful for the field precision instrument, etc., by laminating a pressure sensitive adhesive layer having a high peak temperature of loss tangent [tan δ]to the pressure sensitive adhesive layer containing the polyester. SOLUTION: The objective sheets are obtained by laminating (A) a pressure sensitive adhesive layer containing a polyester having a polycarbonate structure and weight average molecular weight >=20,000 and (B) a pressure sensitive adhesive layer having peak temperature of loss tangent [tan δ] >=-20 deg.C and adjusting the thickness of the layer A <= the thickness of the layer B. The preferable thickness of the layer A is 0.5-50% of the sum of the thickness the layer A and the layer B, especially in the range of 1-10%. The preferable polyester in the layer A is a polyester having a polycarbonate structure having a repeating unit of formula (R is a 2-20C linear or a branched hydrocarbon).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to pressure-sensitive adhesive sheets (sheets, tapes, etc.) for vibration damping materials used in the fields of automobile parts, various home appliances, precision instruments, and the like. is there.

[0002]

2. Description of the Related Art Adhesive sheets for vibration damping materials include automobile parts,
It is used as a means for reducing vibration and noise of various home appliances and precision equipment. Acrylic adhesives and rubber-based adhesives have been used as adhesives, but recently adhesives containing polyesters with a polycarbonate structure have been developed and used. Attempts have been made to use such adhesive sheets for vibration damping materials.

[0003]

However, pressure-sensitive adhesive sheets using a pressure-sensitive adhesive containing a polyester having a polycarbonate structure have a peak temperature of the loss tangent [tan δ] of the polyester itself. , Acrylic polymer
Even if it is a viscoelastic body, it is considerably lower than
The vibration damping performance is limited to a low temperature region, and the vibration damping performance cannot be sufficiently exhibited in a room temperature region where normal use can be considered.

The present invention has been made in view of the above situation, and
It is an object of the present invention to provide pressure-sensitive adhesive sheets for vibration-damping materials having improved vibration-damping performance while maintaining the original properties such as high adhesive strength of a pressure-sensitive adhesive containing a polyester having a bone structure.

[0005]

Means for Solving the Problems The present inventors have developed a polycarbonate
A loss tangent [t] of an acrylic or rubber-based adhesive is applied to the adhesive layer containing a polyester having a bone structure.
An δ] was found to improve the vibration damping performance while maintaining the characteristics of the former pressure-sensitive adhesive layer by laminating the pressure-sensitive adhesive layer having a high peak temperature, thereby completing the present invention.

[0006] That is, the present invention relates to A) polycarbonate
B) a pressure-sensitive adhesive layer containing a polyester having a weight-average molecular weight of 20,000 or more and a peak tangent [tan δ].
A pressure-sensitive adhesive layer having a temperature of -20 ° C. or higher and a layer A having a thickness smaller than a thickness of the layer B. Claim 1
This is related to 4). Further, the present invention has a substrate as a constraining layer, and the above-mentioned A is provided on one or both sides of the substrate.
The pressure-sensitive adhesive sheets for vibration damping material having the above-mentioned structure in which the layer and the B layer are laminated with the A layer on the outside and the B layer on the inside.
6) An adhesive sheet for vibration damping material having the above-mentioned structure, in which a release liner made of polyolefin is attached to the surface of the outer layer A (claims 7 and 8).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The layer A in the present invention comprises a polycarbonate.
A pressure-sensitive adhesive layer containing a polyester having a bone structure, wherein the polyester has the following formula: (Wherein, R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms) having a polycarbonate structure having a repeating unit represented by the following formula: 10,000 or more, usually 20,000 to 200,000, preferably 3
Those having 10,000 to 150,000, more preferably 40,000 to 120,000 are used. When the weight average molecular weight is smaller than 20,000, it becomes difficult to balance the cohesive force and the adhesiveness. On the other hand, if the molecular weight is too large, the coating properties will be poor, which is not preferable.

[0008] Such a polyester can be synthesized by a condensation reaction using a diol and / or dicarboxylic acid having a polycarbonate structure. A diol having a polycarbonate structure is preferably used because it is easily available as a commercial product. The above condensation reaction may be carried out by subjecting such a diol component and a dicarboxylic acid component to an esterification reaction according to a conventional method using no catalyst or an appropriate catalyst.

[0009] Diols having a polycarbonate structure include hexamethylene carbonate diole, 3-methylpentene carbonate diole, and propylene carbonate.
These include mixtures and copolymers of todiol and the like. This diol has a number average molecular weight of usually 500 or more,
Preferably, it is 800 or more (usually up to 10,000). As a commercially available product, "P" manufactured by Daicel Chemical Industries, Ltd.
LACCEL CD208PL "," CD210P
L "," CD220PL "," CD208 "," CD210 "," CD220 "," CD208H "
L "," CD210HL "and" CD220HL ".

As the diol component, if necessary, ethylene glycol, propylene glycol, butanediol
Linear diols such as diol, hexanediol, octanediol, decandiol, octadecandiol,
In addition, various branched diols may be appropriately mixed and reacted. In order to increase the molecular weight of the polymer, 3
A small amount of a functional or higher polyol component may be added.

The dicarboxylic acid component is a dicarboxylic acid having a molecular skeleton of an aliphatic or alicyclic hydrocarbon group having 2 to 20 carbon atoms, even if the above-mentioned hydrocarbon group is linear. Or it may be branched. Specifically, succinic acid, methyl succinic acid, adipic acid, pimelicic acid, azelaic acid, sebacic acid, 1,12-dodecandioic acid, 1,14-tetradecandioic acid, tetrahydrophthalic acid, etc. And lower alkyl esters.

The layer B in the present invention has a loss tangent [tan].
δ] is a pressure-sensitive adhesive layer having a peak temperature of −20 ° C. or higher, and particularly, a peak temperature of a loss tangent [tan δ] of −10 ° C.
It is preferable that the pressure-sensitive adhesive layer has a loss tangent [tan δ] of 0.7 ° C. or higher (usually 50 ° C. or lower) at the peak temperature of 0.7 or higher. By laminating such a pressure-sensitive adhesive layer on the pressure-sensitive adhesive layer of the layer A, the temperature range in which the vibration-damping effect is exhibited is higher than that of the layer A alone, and the vibration-damping effect near room temperature is sufficiently improved. Will be obtained.

In this specification, the loss tangent [ta
nδ] refers to the ratio of the loss elastic modulus to the storage elastic modulus [G '], which means the phase from the stress applied to the material (adhesive layer) to the occurrence of distortion, More specifically, it means the tangent of the phase angle (loss angle δ) between the stress and strain generated in the material when the material is subjected to steady sinusoidal strain. The loss tangent [tan δ] varies depending on the temperature, and in this specification, the temperature at which the above value becomes the maximum is referred to as the peak temperature. Needless to say, this peak temperature and its loss tangent [tan δ] differ depending on the type of material.

As the layer B in the present invention, any pressure-sensitive adhesive layer may be used as long as the above properties are satisfied.
Representative examples include an acrylic adhesive containing an acrylic polymer and a rubber adhesive containing a rubbery polymer such as natural rubber or synthetic rubber. In the acrylic adhesive, the acrylic polymer has 4 to 4 carbon atoms.
A polymer of a monomer comprising 50 to 100% by weight of a (meth) acrylic acid alkyl ester having 14 alkyl groups and 50 to 0% by weight of a modifying monomer copolymerizable therewith is used. Examples of the alkyl group in the alkyl (meth) acrylate include a butyl group, a 2-ethylhexyl group, an octyl group, an isononyl group, a hexyl group, an isoamyl, a lauryl group, and an isomiristyl group. Examples of the modifying monomer include various known monomers such as (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, vinyl chloride, vinyl acetate, (meth) acrylonitrile, styrene, and (meth) acrylamide. Can be used.

In the present invention, the pressure-sensitive adhesive layers of the above-mentioned A layer and B layer can be made to have excellent adhesiveness and heat resistance by forming a crosslinked structure using an appropriate crosslinking method. . As the crosslinking method, a method in which a polyfunctional compound such as a polyisocyanate compound, an epoxy compound, or an aziridine compound is added as a crosslinking agent, and the resultant is reacted with a hydroxyl group or a carboxyl group contained in the adhesive polymer is preferably used. . Among the crosslinking agents, polyisocyanate compounds are particularly preferred.

Examples of the polyisocyanate compound include lower aliphatic polyisocyanates such as ethylene diisocyanate, butylene diisocyanate and hexamethylene diisocyanate, cyclopentylene diisocyanate,
Alicyclic isocyanates such as cyclohexylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylyl There are aromatic diisocyanates such as range isocyanate and isocyanate adducts such as tolylene diisocyanate adduct of hexamethyldipropane and hexamethylene diisocyanate adduct of trimethylolpropane. , One or more of them are used. The amount to be used is appropriately selected depending on the balance with the adhesive polymer to be crosslinked and the application field of the adhesive sheet. Usually, the amount is 1 part by weight or more based on 100 parts by weight of the polymer. The solvent-insoluble content after crosslinking is preferably at least 20% by weight, more preferably at least 25% by weight.

If necessary, the pressure-sensitive adhesive layers of the layers A and B may contain various conventionally known tackifiers, antioxidants, etc., so that the adhesiveness and heat resistance can be improved. In some cases, it becomes easier to balance vibration control and the like. Further, the pressure-sensitive adhesive layers of the A layer and the B layer may optionally contain various known additives such as inorganic or organic fillers, powders such as metal powders and pigments, particles, and foils. be able to.

The pressure-sensitive adhesive sheets for vibration damping materials of the present invention are preferably those having the above-mentioned A
It is characterized in that the pressure-sensitive adhesive layer of the layer and the pressure-sensitive adhesive layer of the layer B are laminated, but the thickness of the layer A needs to be smaller than the thickness of the layer B. Preferably, the thickness of the layer A is in the range of 0.5% or more and less than 50% of the total thickness of the layer A and the layer B, particularly in the range of 1 to 10%. When the thickness of the layer A is larger than that of the layer B, the temperature range in which the vibration damping effect can be exhibited cannot be sufficiently increased, and the vibration damping effect near room temperature becomes insufficient. On the other hand, if the thickness of the layer A is too small, it is not preferable because the production of the layer A itself becomes difficult or the characteristics of the layer A are lost. The pressure-sensitive adhesive layer of the layer A and the pressure-sensitive adhesive layer of the layer B may be each used in two or more layers to form a laminated structure of three or more layers as a whole.

The pressure-sensitive adhesive sheet for vibration damping material of the present invention may be composed of only a pressure-sensitive adhesive layer having such a laminated structure, but usually has a thickness of about 10 to 1,000 μm as a constraining layer. By using a base material made of metal foil or plastic film of this type and providing an adhesive layer with the above-mentioned laminated structure on one or both sides of this base material, an adhesive sheet such as a sheet or tape is formed. Can be similar. At this time, the polyester-based pressure-sensitive adhesive layer A is laminated by laminating the pressure-sensitive adhesive layer of layer A on the outside and the pressure-sensitive adhesive layer of layer B on the inside of the pressure-sensitive adhesive layers of both layers A and B. The properties such as high adhesive strength of the agent can be utilized. The total thickness of the pressure-sensitive adhesive layer composed of both the A and B layers varies depending on the field of application as a vibration damping material, but is usually preferably 10 to 2,000 μm.

Such an adhesive sheet for vibration damping material has an adhesive force of 1,000 g / 20 with respect to the adherend (stainless steel plate).
It shows a high adhesive strength of not less than mm width, and no breakage occurs between the layer A and the layer B under this adhesive force. Therefore, excellent adhesive performance can be exhibited as a vibration damping material for reducing vibration and noise in various fields such as automobile parts, various home appliances, and precision equipment.

In the pressure-sensitive adhesive sheets for vibration damping material having the above-described structure, a release liner is attached to the pressure-sensitive adhesive surface in order to protect the pressure-sensitive adhesive surface before use and to improve handleability. As the release liner, a release liner made of polyolefin as a release liner not subjected to a silicon treatment can be used. This is because the outer pressure-sensitive adhesive layer of layer A is composed of a polyester-based pressure-sensitive adhesive, that is, a pressure-sensitive adhesive layer containing a polyester having a polycarbonate structure. Even when a release liner made of the following is bonded, the release force of this release liner is 200 g / 50 mm width or less, preferably 100 g / 50 mm.
This is because the width can be set to be equal to or smaller than the width.

On the other hand, if the outer layer is made up of an adhesive layer made of an acrylic adhesive or the like, the above-mentioned adhesive line is adhered to the silicone-treated release liner unless it is bonded. Cannot be set to peel force. However, the use of the silicon-treated release liner results in the generation of siloxane gas inside the electronic device due to the silicon migrating to the adhesive surface, which results in corrosion and malfunction of the electronic device. The adhesive sheet for vibration damping material of the present invention can use a release liner made of polyolefin, and therefore does not have such a problem, and can be effectively used inside electronic equipment.

Examples of the release liner made of polyolefin include polyethylene, polypropylene, ethylene-
There is a polyolefin-based film or the like made of a propylene copolymer or a mixture thereof, and a laminated film whose surface is processed with the same polyolefin as described above, that is, a release layer is made of the above-described polyolefin, and another plastic film is laminated thereon. Film is used.

In the pressure-sensitive adhesive sheets for vibration damping material of the present invention, when a substrate as a constraining layer is used, the pressure-sensitive adhesive of layer B and the pressure-sensitive adhesive of layer A are simultaneously coated on the substrate. Then, a pressure-sensitive adhesive layer having a laminated structure is formed, and a release liner made of polyolefin is bonded to the pressure-sensitive adhesive layer. Further, after forming a pressure-sensitive adhesive layer of layer B on the base material, a pressure-sensitive adhesive layer of layer A is formed thereon, and a release liner made of polyolefin is attached to the pressure-sensitive adhesive layer.
It may be produced. Furthermore, after forming the B layer pressure-sensitive adhesive layer on the base material, and bonding the A layer pressure-sensitive adhesive layer formed on the release liner made of polyolefin to this,
It may be produced. The pressure-sensitive adhesive layer having a laminated structure may be formed on one side or both sides of the substrate.

[0025]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the scope of the present invention is not limited by the following examples. The polyester solution A and the acrylic polymer solution B used in Examples were respectively obtained by the methods of Reference Examples 1 and 2 below.
It was prepared.

Reference Example 1 A four-neck separable flask equipped with a stirrer, a thermometer and a water separation tube was charged with polycarbonate [DIALCEL Co., Ltd. "PLACCEL CD".
220PL ", hydroxyl value: 56.1 KOHmg / g] 25
0 g, sebacic acid 26 g, titanium tetraisopropoxide (hereinafter referred to as TPT) 70 mg as a catalyst, and in the presence of a small amount of toluene as a solvent for discharging reaction water,
While stirring was started, the temperature was raised to 180 ° C. and maintained at this temperature. After a while, effluent separation of water was observed, and the reaction began to proceed. The reaction was continued for about 27 hours to obtain a polyester having a weight average molecular weight of 41,000. The polyester solution A was prepared by diluting the polyester with toluene to a solid concentration of 50% by weight.

Reference Example 2 A monomer mixture of 88 parts of isononyl acrylate and 12 parts of acrylic acid was used, and 150 parts of toluene and 0.1 part of azobisisobutyronitrile were added to the monomer mixture. The mixed solution is placed in a nitrogen atmosphere at 60
Acrylic polymer solution B after solution polymerization for about 7 hours
Was prepared. The peak temperature of the loss tangent [tan δ] of the acrylic polymer itself measured by the method described later is +2.
° C.

Example 1 A polyester solution A prepared in Reference Example 1 was mixed with 100 parts of polyester (solid content) per 100 parts of polyester (solid content) as a crosslinking agent with hexamethylene diisocyanate adduct of trimethylolpropane ("Corone" manufactured by Nippon Polyurethane Co.). To HL ") to prepare a pressure-sensitive adhesive composition A. This pressure-sensitive adhesive composition A was applied to an applicator to a thickness of 38 μm.
m on a 50 μm thick polyethylene (PE) film lined with a polyethylene terephthalate (PET) film, and dried at 100 ° C. for 5 minutes to form an adhesive layer A having a thickness of 5 μm. did.

To the acrylic polymer solution B prepared in Reference Example 2, per 100 parts (solid content) of the acrylic polymer, a tolylene dipropane adduct of trimethylolpropane (manufactured by Nippon Polyurethane Co., Ltd.) was used as a crosslinking agent. "Coronate L") 2 parts (solid content) and pressure-sensitive adhesive composition B
Was prepared. This pressure-sensitive adhesive composition B was applied on an aluminum foil having a thickness of 50 μm using an applicator, and 13
Drying at 0 ° C. for 3 minutes, adhesive layer B having a thickness of 100 μm
Was formed. Similarly, a sample for loss tangent [tan δ] measurement was also applied to a silicone-treated PET film, dried at 130 ° C. for 3 minutes, and dried to a thickness of 100 μm.
An adhesive layer B having a thickness of μm was formed.

Next, on the pressure-sensitive adhesive layer B having a thickness of 100 μm formed on the aluminum foil, a thickness of 5 μm was formed on a PE film lined with a PET film.
Of the pressure-sensitive adhesive layer A was laminated to prepare a pressure-sensitive adhesive sheet for a vibration damping material. Here, the aluminum foil constitutes a substrate (constraining layer), and the PE film lined with the PET film constitutes a release liner.

With respect to the pressure-sensitive adhesive sheet thus produced, the loss tangent [tan δ] of the pressure-sensitive adhesive layer having a laminated structure composed of the pressure-sensitive adhesive layers A and B was measured by the following method.
As a result, the peak temperature of the loss tangent on the side of the first peak (derived from the adhesive layer A) was −43 ° C., and the loss tangent [tan δ] at the same peak temperature was 0.91; The peak temperature of the loss tangent on the side of the second peak (derived from the adhesive layer B) is 0 ° C., and the loss tangent [tan δ] at the peak temperature is 1.1.
It was.

<Measurement of loss tangent [tan δ]> A test sample having a thickness of about 1.0 mm was prepared by laminating the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B together as a single layer, and then laminating a plurality of layers. Is prepared. Using this test sample, using a parallel plate jig with a diameter of 7.9 mm, using a "dynamic viscoelasticity measuring device ARES" manufactured by Rheometrics Co., Ltd.
Under the condition of a frequency of 1 Hz, loss tangents [tan δ] in various temperature ranges were measured.

Example 2 The pressure-sensitive adhesive layer A had a thickness of 45 μm, and the pressure-sensitive adhesive layer B had a thickness of 55 μm.
An adhesive sheet for a vibration damping material was produced in the same manner as in Example 1 except that the thickness was changed to μm.

Example 3 The thickness of the pressure-sensitive adhesive layer A was 25 μm, and the thickness of the pressure-sensitive adhesive layer B was 65 μm.
An adhesive sheet for a vibration damping material was produced in the same manner as in Example 1 except that the thickness was changed to μm.

Comparative Example 1 The pressure-sensitive adhesive composition A prepared in Example 1 was applied on an aluminum foil having a thickness of 50 μm using an applicator.
Dry at 00 ° C. for 5 minutes to obtain an adhesive layer A having a thickness of 50 μm.
Was formed. The pressure-sensitive adhesive layer A has a thickness of 50 μm lined with a 38 μm-thick PET film as a release liner.
Then, an adhesive sheet for a vibration damping material was prepared by laminating the m-type PE films.

Also, separately from this, the loss tangent [tan
δ] As a measurement sample, the above-mentioned pressure-sensitive adhesive composition A was applied on a 50 μm-thick PE film lined with a 38 μm-thick PET film, dried at 100 ° C. for 5 minutes, and dried to a thickness of 50 μm. Pressure-sensitive adhesive layer A was formed. Using this pressure-sensitive adhesive layer A, the loss tangent [tan δ] of the pressure-sensitive adhesive layer A alone was measured in the same manner as in Example 1. As a result, the peak temperature of the loss tangent was -44 ° C., and the loss tangent [tan δ] at the same peak temperature was 1.9.

Next, the pressure-sensitive adhesive sheets for vibration damping materials of Examples 1 to 3 and Comparative Example 1 were subjected to a peeling force test, an adhesive force test and a vibration damping test of a release liner by the following methods. I went. The results were as shown in Table 1.

<Peeling Force Test of Release Liner> The substrate side of the adhesive sheet was adhered to a metal plate, and the 180 ° peeling force of the release liner was measured under the conditions of an atmosphere temperature of 23 ° C. and a peeling speed of 300 mm / min. .

<Adhesion Test> The peeling liner of the adhesive sheet was peeled off and a stainless steel plate [SUS304
(Mirror finish)], at an ambient temperature of 23 ° C., a sticking time of 30 minutes, and a peeling speed of 300 mm / min.
The 0 ° peel adhesion was measured. Further, under the measurement of the peel adhesion, the presence or absence of breakage between the pressure-sensitive adhesive layers A and B was examined.

<Vibration Suppression Test> Measured by the mechanical impedance method in the center vibration. Measurement is 1KHz
For the nearby resonance points, the loss coefficient at room temperature was determined by the half-width method from the transfer function. The shape of the test piece was such that an adhesive sheet was sandwiched between a spcc steel plate having a thickness of 0.5 mm as a base layer and SUS304 having a thickness of 0.05 mm as a constraining layer. 250mm, width 1
0 mm.

[0041]

As is clear from the results in Table 1 above, the adhesive sheets for vibration damping materials of Examples 1 to 3 of the present invention show a large adhesive force to the stainless steel plate, No destruction between the pressure-sensitive adhesive layers A and B was observed below,
It shows that the original excellent adhesive performance is exhibited, the vibration damping performance in the room temperature region is also excellent, and the releasability of the release liner is also satisfactory. On the other hand, the pressure-sensitive adhesive sheet for vibration damping material of Comparative Example 1 is clearly inferior in vibration damping performance in a room temperature range, even though the adhesive force and the peelability of the release liner can be satisfied.

[0043]

As described above, in the present invention, the loss tangent [ta] of an acrylic or rubber-based adhesive is applied to the adhesive layer containing a polyester having a polycarbonate structure.
By laminating the pressure-sensitive adhesive layer having a high peak temperature of [nδ], it is possible to provide pressure-sensitive adhesive sheets for vibration damping materials having improved vibration-damping performance while maintaining the characteristics of the former pressure-sensitive adhesive layer. Also,
By providing the pressure-sensitive adhesive layer having the above-mentioned laminated structure such that the former pressure-sensitive adhesive layer is provided on the base material as a constraining layer on the outside and the latter pressure-sensitive adhesive layer is provided on the inside, It is possible to attach a release liner made of polyolefin, which eliminates the need for a silicone release treated release liner and is particularly suitable for applications such as electronic devices that dislike silicon. Sheets can be provided.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Waka Hikosaka 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Hiroshi Yamamoto 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Naoyuki Nishiyama 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (72) Inventor Yasunori Sugihara 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko (72) Inventor Hideyuki Kitai 1-2-1 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation F-term (reference) 4F100 AB10 AB33 AK04 AK42 AK45A AK45E AR00B AR00D AR00E AT00C BA03 BA05 BA06 BA07 BA10A BA10C BA10E BA13 CA02 EH46 EJ91 GB32 GB48 GB51 JA20A JA20B JA20D JA20E JH02 JK06 JK06A JK06B JK06D JK06E JL13 JL13A JL13B JL13D JL13E JL14E YY00A YY00B YY00D YY00E 4J0 04 AA04 AA05 AA10 AA15 AB01 CA08 CC02 CC03 CE01 DA02 DB02 DB04 EA05 4J040 EL021 JA09 JB09 LA01 MA02 NA16 NA19 5D061 GG01

Claims (8)

[Claims] 1. A) an adhesive layer containing a polyester having a polycarbonate structure and having a weight average molecular weight of 20,000 or more; and B) a peak temperature of a loss tangent [tan δ] of -20 ° C.
A pressure-sensitive adhesive sheet for vibration damping material, wherein the pressure-sensitive adhesive layer described above is laminated, and the thickness of the layer A is smaller than the thickness of the layer B. 2. The polyester in the layer A has the following formula: 2. A polyester having a polycarbonate structure having a repeating unit represented by the formula: wherein R is a linear or branched hydrocarbon group having 2 to 20 carbon atoms. Adhesive sheets for vibration damping materials. 3. The layer B according to claim 1, wherein the peak temperature of the loss tangent [tan δ] is -10 ° C. or more, and the loss tangent [tan δ] at the peak temperature is 0.7 or more. Adhesive sheets for vibration damping materials. 4. The adhesive sheet for vibration damping material according to claim 1, wherein the thickness of the layer A is in the range of 0.5% or more and less than 50% of the total thickness of the layer A and the layer B. . 5. A base material serving as a constraining layer, wherein one or both sides of the base material have an A layer and a B layer,
The pressure-sensitive adhesive sheet for vibration damping material according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive sheet is laminated with the layer inside. 6. The adhesive strength is 1,000 g / 20 mm width or more with respect to an adherend (stainless steel plate).
The adhesive sheet for vibration damping material according to claim 5, wherein no destruction is observed between the layer and the B layer. 7. The adhesive sheet for vibration damping material according to claim 5, wherein a release liner made of polyolefin is bonded to a surface of the outer layer A. 8. The release force of the release liner is 200 g / 50 mm.
The vibration-damping adhesive sheet according to claim 7, which is not more than a width.