JP4150784B2 - Foamed sheets, foamed adhesive sheets and methods for producing them - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to foamed sheets that can be used as foamed pressure-sensitive adhesive sheets and the like, and more particularly to a method for producing the foamed sheets, and more particularly, because it has air bubbles in the pressure-sensitive adhesive composition layer, it is easy to adhere to a non-smooth surface. The present invention relates to foamed sheets that do not cause a volume reduction that causes “rolling” and the like, and a method for manufacturing the same.
[0002]
[Prior art]
A component that forms air bubbles in the pressure-sensitive adhesive layer of pressure-sensitive adhesive sheets such as pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets, for example, hollow glass, for the purpose of obtaining sufficient adhesion even when adhered to a non-smooth surface It is known to incorporate microspheres.
[0003]
The hollow glass microspheres blended in this pressure-sensitive adhesive layer are broken by the pressure at the time of bonding, and are more broken at the portion where the pressure is strongly applied (the convex portion as the bonding surface). As a result of not being destroyed so much in a portion that does not take much (a concave portion as an adhesive surface), it adheres to an adhesive surface having irregularities on average and exhibits an excellent adhesive force.
[0004]
However, since hollow glass microspheres are extremely fragile, it is difficult to mix with other constituents of the pressure-sensitive adhesive layer, and development of means for forming hollow spheres in the pressure-sensitive adhesive layer by simpler means is required. It was.
[0005]
On the other hand, a microcapsule-type spherical polymer (hereinafter referred to as “foaming agent”) is known that contains a volatile hydrocarbon liquid inside and expands and foams by volatilizing the hydrocarbon. This foaming agent is commercially available in the unexpanded or foamed state under trade names such as EXPANSEL and Micropearl.
[0006]
The use of such a foaming agent in place of hollow glass microspheres to obtain the above-mentioned pressure-sensitive adhesive having air bubbles is easily conceived by those skilled in the art. No. 8-32435 is disclosed.
[0007]
However, it has been extremely difficult to produce pressure-sensitive adhesive sheets such as pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets that are actually accepted as products using a pressure-sensitive adhesive composition containing a foaming agent. That is, using the above-mentioned pressure-sensitive adhesive composition containing a foaming agent, after applying to a general film, if a general release paper is attached to this and heated and foamed, pressure-sensitive adhesive sheets having air bubbles are obtained. Since the volume of the pressure-sensitive adhesive layer decreased with time from immediately after foaming, defects called so-called “skinning” and “winding” occurred, and there was a problem that the value as a product was lost.
[0008]
“Wrinkle” refers to ripples on the surface of the pressure-sensitive adhesive, and the phenomenon that the central portion is recessed compared to both ends. “Wound” refers to the pressure-sensitive adhesive layer and covering (release paper) generated in the pressure-sensitive adhesive tape. However, when these occur, not only the appearance is deteriorated but also the actual adhesion ability is lowered, and these phenomena are serious problems.
[0009]
Therefore, although the above-mentioned patent discloses a pressure-sensitive adhesive using a foaming agent, as far as the applicant knows, no product using this technology has been provided so far.
[0010]
[Problems to be solved by the invention]
Accordingly, there has been a demand for the development of foamed adhesive sheets that suppress the volume reduction that causes “loss” and “winding” while using the foaming agent.
In addition, a foamed sheet prepared by adding a foaming agent to a resin having low or no adhesiveness can also be used as a foamed adhesive sheet similar to the above by providing an adhesive layer on one or both sides. Development of not only the pressure-sensitive adhesive sheet but also a general foamed sheet with suppressed volume reduction has been demanded.
[0011]
[Means for Solving the Problems]
The present inventor has been diligently researching to solve the above problems, and surprisingly, by selecting the release paper and the resin composition to be used, the volume decrease with time in the foamed sheet is suppressed, and “skin” and “ The present inventors have found that the problem of “winding” can be solved and completed the present invention.
[0012]
That is, the first object of the present invention is to contain a hollow sphere obtained by expanding and foaming the thermally expandable resin particles, and the storage elastic modulus and loss elastic modulus at 120 ° C. are 10 ⁹ dyne / cm ² or less . the resin composition layer is a thickness of 0.2 to 3 mm, after bonding as peelable release paper using an inorganic powder coated paper, inhibited the reduction in volume that is obtained by aging the foam sheet It provides a kind.
The second object of the present invention is to use inorganic powder-coated paper with a resin composition containing thermally expandable resin particles and having a storage elastic modulus and loss elastic modulus at 120 ° C. of 10 ⁹ dyne / cm ² or less. By providing a method for producing foamed sheets that suppresses volume reduction, which is characterized by applying a foamed release paper to a thickness of 0.2 to 3 mm and drying it, followed by heat foaming treatment. is there.
Furthermore, a third object of the present invention is to provide a resin composition having a storage elastic modulus and loss elastic modulus at 120 ° C. of 10 ⁹ dyne / cm ² or less of a hollow sphere obtained by expanding and foaming thermally expandable resin particles. It is mixed in and applied to release paper using inorganic powder-coated paper so that the resin composition has a thickness of 0.2 to 3 mm. It is providing the manufacturing method of expanded foam sheet.
Furthermore, the fourth object of the present invention is to provide a foamed pressure-sensitive adhesive sheet or a method for producing the same using the above foamed sheet or the method for producing the same.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The foam sheet of the present invention is a resin composition having a storage elastic modulus at 120 ° C. and a loss elastic modulus of 10 ⁹ dyne / cm ² or less, in which hollow spheres obtained by expanding and foaming a foaming agent are held inside. It is prepared by adhering to a release paper using inorganic powder-coated paper so that it can be peeled off.
[0014]
In the present invention, the elastic modulus refers to an elastic modulus obtained by dynamic viscoelasticity measurement of a polymer substance, the storage elastic modulus indicates the elastic characteristic of the sample, and the loss elastic modulus reflects the viscous characteristic of the sample. To do. And the elasticity modulus about a resin composition can be measured using viscoelasticity measuring machines, such as VES-F-III by Iwamoto Seisakusho Co., Ltd., for example.
[0015]
The resin composition used in the present invention is required to have a storage elastic modulus and a loss elastic modulus measured as described above of 120 ° C. or lower and 10 ⁹ dyne / cm ² or lower, more preferably 10 ^{It is 4} dyne / cm ² or more and 10 ⁹ dyne / cm ² or less.
[0016]
When these elastic moduli are 10 ⁹ dyne / cm ² or more, the deformability of the resin layer is small, the foamed particles are not sufficiently foamed, and a foamed sheet may not be obtained. Moreover, when these elastic moduli are 10 ⁴ dyne / cm ² or less, since the deformability of the resin layer is too large, a foam sheet that can be used as an adhesive sheet or the like may be obtained.
[0017]
The resin composition of the present invention is not particularly limited as long as the storage elastic modulus and loss elastic modulus satisfy the above conditions and have good affinity with the hollow particles described later. Examples of the resin composition include a resin such as a (meth) acrylate ester-based resin, a styrene- (meth) acrylate ester copolymer-based resin, or a vinyl acetate-based resin.
[0018]
In particular, it is preferable to use a resin composition containing a (meth) acrylic acid ester-based adhesive resin as a main component as the resin composition because a foamed adhesive sheet can be easily obtained.
[0019]
Further, in the present invention, the hollow spheres to be blended in the resin composition are commodities such as EXPANSEL DU-551, DU-461 (manufactured by EXPANSEL), and Micropearl F-30 (manufactured by Matsumoto Yushi Seiyaku Co., Ltd.). It is obtained by mixing an unfoamed foaming agent sold under the name into a resin composition, making it uniform and heating it to foam the foaming agent. Further, a foamed foaming agent that is already marketed as a foamed product, for example, Expandel 551DE, 461DE (Expancel) may be used.
[0020]
Among the above, it is preferable to use an unfoamed foaming agent having an expansion temperature of about 80 to 160 ° C. and an average particle diameter after expansion of about 0.02 to 0.3 mm.
[0021]
The amount of the hollow particles to be blended in the resin composition is not particularly limited, but in order to obtain a product having excellent properties as foamed sheets, the volume ratio of the hollow spheres to the resin composition is 1: It is desirable to be about 0.2 to 1: 5.
[0022]
On the other hand, as the release paper to which the resin composition containing the hollow sphere is applied, a release paper using paper coated with inorganic powder such as clay (hereinafter referred to as “inorganic powder coated release paper”) is used. Is essential. In general, release paper used for adhesive sheets, adhesive tapes, etc. is made of silicone on paper that has been sealed so that silicone as a peeling component does not penetrate, or glassine paper, plastic film, etc. that have a sealing effect from the beginning. It is prepared by applying. Examples of the sealing treatment for paper in this case include a method of extrusion-coating polyethylene, a method of coating inorganic powder such as clay, a method of supercalendering, and a method of applying a water-soluble paint. In Japan, it is common to use a paper obtained by extrusion-coating polyethylene and applying silicone as a release paper.
[0023]
In the present invention, even if a release film or release paper other than the inorganic powder-coated release paper is used, the volume reduction with time cannot be prevented, and as a result, “loss” and “winding” occur. For example, if the resin composition containing the above foaming agent is applied to a general release film or paper and then foamed by heating to produce foamed sheets, foaming can be performed, but the volume of the foam decreases over time immediately after foaming. After 24 hours, the volume is reduced by several tens of percent. When stored in a roll-like material, the surface of the roll becomes uneven and many “rolls” occur, resulting in a loss of commercial value. Therefore, in the foamed sheets of the present invention, the inorganic powder-coated release paper must be used as the release paper.
[0024]
Specific examples of the method for preparing the foamed sheets of the present invention include the following examples. That is, first, a resin, an unfoamed foaming agent, and a solvent are sufficiently mixed to obtain a resin composition, which is defoamed under reduced pressure with a defoamer if necessary, and then applied to an inorganic powder-coated release paper. Next, after drying at a temperature of about 80 ° C. and removing the solvent in the resin composition, the mixture is further heated to a temperature of about 100 to 120 ° C. to foam the foaming agent to form hollow spheres in the resin composition. After foaming, the resin layer is cured for a certain period of time, and if necessary, the volume is reduced or the separator is replaced with foamed sheets. In the above process, a winding process may be added between the drying process and the heating process, or between the heating process and the curing process.
[0025]
In the said method, if an adhesive thing is used as resin, a foaming adhesive sheet can be obtained directly.
[0026]
In addition, as another example of the method for producing the foamed sheets of the present invention, hollow spheres already obtained by foaming are added to the resin and mixed, and this composition is applied to an inorganic powder-coated release paper according to a conventional method. The method of drying after application | coating and making it into foam sheets is mentioned. Also in this method, if an adhesive is used as the resin, directly foamed adhesive sheets can be obtained.
[0027]
Furthermore, in both the above methods, when foamed sheets having low or no tackiness are obtained, foamed pressure-sensitive adhesive sheets are prepared by further providing a pressure-sensitive adhesive layer on one or both sides of the sheets. Can do. In order to provide the pressure-sensitive adhesive layer on the foamed sheets, a known method may be used.
[0028]
[Action]
The foamed sheets of the present invention are suppressed in volume reduction, and the reason why neither “lean” nor “winding” occurs is yet clear, but the inorganic powder used as a sealing agent for the inorganic powder-coated release paper It is thought that the adsorption power of is related.
[0029]
That is, a solvent is used in the resin composition, and a drying step is provided to remove it, but a trace amount of the solvent remains in the resin layer. The solvent gradually evaporates, is trapped by the release paper, and collects between the release paper and the resin layer. In ordinary resin sheets, this is not a problem, but in foam sheets, this solvent acts on the hollow sphere near the surface and destroys it, resulting in a loss of the thickness of the resin layer, resulting in a volume increase. Decrease.
[0030]
In contrast, when the inorganic powder-coated release paper is used, it is presumed that the solvent that gradually volatilized is adsorbed to the inorganic powder, so that the hollow sphere is not destroyed and the volume change is suppressed. .
[0031]
【The invention's effect】
The foamed sheets of the present invention thus obtained, when used as a pressure-sensitive adhesive sheet, are averagely adhered to a non-smooth adhesive surface having irregularities, exhibiting excellent adhesive strength, and suppressing volume reduction. "Or" winding "is not generated, and it is advantageously used as an adhesive sheet for structures for vehicles or building materials, an adhesive tape for hook hangers, furniture, or the like.
[0032]
【Example】
EXAMPLES Next, although an Example and a test example are given and this invention is demonstrated in more detail, this invention is not restrict | limited at all by these Examples.
[0033]
Example 1
Adhesive resin composition was prepared by thoroughly mixing the following composition, and the surface of clay-coated release paper (125Y-832 (IR / B); thickness 125 μ; manufactured by Fujimori Kogyo Co., Ltd./release paper 1) Coating was carried out using a doctor blade. This was dried in an air dryer at 80 ° C. for 5 minutes to obtain a sheet-like material having a thickness of 0.25 mm. When the dynamic viscoelasticity of the obtained sheet-like material was measured using a viscoelasticity measuring machine (VES-F-III) manufactured by Iwamoto Seisakusho, the storage elastic modulus at a frequency of 10 Hz was 4.5 × 10 ⁵ dyne / cm ^2. The loss elastic modulus was 2.4 × 10 ⁵ dyne / cm ² (both at 120 ° C.).
The light side of release paper 1 is laminated on the sheet, and left in a 120 ° C. blast dryer for 3 minutes to foam, to obtain a sheet in which both sides of a 1.00 mm thick foam sheet are sandwiched with release paper 1 It was. When this sheet was aged at 40 ° C. for 24 hours, there was no volume reduction and a foamed adhesive sheet having a sheet thickness of 1.00 mm was obtained.
[0034]
(Adhesive composition)
SK Dyne 1578 ^{* 1} 333 parts Expandance DU-551 ^{* 2} 10 parts E-AX ^{* 3} 2 parts Note) * 1: Acrylic adhesive (acrylic resin 30%; manufactured by Soken Chemical Co., Ltd.)
* 2: Foaming agent (unfoamed; manufactured by Expancel)
* 3: Tetrafunctional epoxy crosslinking agent (manufactured by Soken Chemical Co., Ltd.)
[0035]
Example 2
A foamed pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the release paper was changed to another clay coat release paper (WBF90F-D; thickness 120 μ; manufactured by Lintec Corporation / release paper 2). The thickness of the sheet immediately after foaming was 1.00 mm, there was no volume reduction after aging for 24 hours, and the thickness was 1.00 mm.
[0036]
Comparative Example 1
A foamed adhesive sheet was prepared in the same manner as in Example 1 except that the release paper was MDPE-coated release paper (WEW80KB-BX; thickness 125 μ; manufactured by Lintec Corporation / release paper 3). The thickness of the sheet immediately after foaming was 1.00 mm, and the thickness after aging for 24 hours was 0.74 mm.
[0037]
Comparative Example 2
A foamed pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the release paper was changed to a supercalender treated release paper (S80 # SB SCK6E / 6H; thickness 130 μ; manufactured by Legzam Release / release paper 4). The thickness of the sheet immediately after foaming was 1.00 mm, and the thickness after aging for 24 hours was 0.90 mm.
[0038]
Comparative Example 3
A foamed adhesive sheet was prepared in the same manner as in Example 1 except that the release paper was glassine release paper (GW-702A; thickness 65 μ; manufactured by Lintec Corporation / release paper 5). The thickness of the sheet immediately after foaming was 1.00 mm, and the thickness after aging for 24 hours was 0.92 mm.
[0039]
Comparative Example 4
A foamed adhesive sheet was prepared in the same manner as in Example 1 except that the release paper was changed to another glassine release paper (110XT-832 (IR / B); thickness 110 μ; manufactured by Fujimori Kogyo Co., Ltd./release paper 6). . The thickness of the sheet immediately after foaming was 1.00 mm, and the thickness after aging for 24 hours was 0.89 mm.
[0040]
Example 3
Using a coating apparatus with a drying apparatus capable of continuous coating with a width of 500 mm, using a release paper (release paper 1) clay-coated under the same conditions as in Example 1, a sheet having a width of 500 mm and a length of 100 m A roll-shaped product was prepared. At this time, foaming was performed in a sandwich with the release paper 1, and the release paper on one side was peeled off after foaming and wound on the back surface. The thickness of the sheet immediately after foaming was 1.00 mm, and the sheet aged at 40 ° C. for 24 hours had no volume reduction and the thickness was 1.00 mm. Also, the roll appearance was not changed at all, and it was a beautiful roll.
[0041]
Comparative Example 5
A sheet roll was produced in the same manner as in Example 3 except that the release paper was MDPE coated release paper (release paper 3). The sheet thickness immediately after foaming was 1.00 mm, and there were no defects in the appearance of the roll, but after aging at 40 ° C. for 24 hours, volume shrinkage occurred to a sheet thickness of 0.70 mm. When the roll was aged, a large number of windings were observed, and a tanned thinning and unevenness of the roll due to the winding were observed.
[0042]
Comparative Example 6
A roll of sheet was prepared in the same manner as in Example 3 except that the release paper was changed to a supercalender treated release paper (release paper 4). The sheet thickness immediately after foaming was 1.00 mm and there were no defects in the appearance of the roll, but after aging at 40 ° C. for 24 hours, volume shrinkage occurred to a sheet thickness of 0.85 mm. When the roll was aged, a large number of windings were observed, and a tanned thinning and unevenness of the roll due to the winding were observed.
[0043]
Comparative Example 7
A roll of sheet was prepared in the same manner as in Example 3 except that the release paper was glassine release paper (release paper 5). The sheet thickness immediately after foaming was 1.00 mm and there were no defects in the appearance of the roll, but after aging at 40 ° C. for 24 hours, volume shrinkage occurred to a sheet thickness of 0.68 mm. Although a large number of windings did not occur in the roll after ripening, remarkable pinching-like thinning and unevenness of the roll due to it were observed.
[0044]
Example 4
While stirring with stirring, 95 g of 2-ethylhexyl acrylate, 5 g of acrylic acid and 0.3 g of normal dodecyl mercaptan were put into a 0.2-liter four-necked flask equipped with a stirrer, a thermometer, a nitrogen introduction tube and a cooling tube. The temperature was raised to 60 ° C. in a nitrogen stream. Subsequently, 0.1 g of azobisisobutyronitrile (AIBN) was added, and the reaction was performed for 30 minutes while maintaining 60 ° C. The obtained partial polymer was a viscous resin liquid having a polymer content of 70% and a viscosity of 100 parts.
[0045]
After cooling 90 g of this resin solution to room temperature, 0.5 g of V-70 (manufactured by Wako Pure Chemical Industries, Ltd.) as an initiator and 10 g of a foaming agent (Expancel DU551) are added and mixed, and a 0.1 mm peeling treatment is performed. The coated PET film was coated using a doctor blade, sandwiched between the same PET films, and then polymerized and cured in a blow dryer at 70 ° C. for 5 minutes to obtain a sheet having a thickness of 0.25 mm (storage) Elastic modulus = 6.2 × 10 ⁵ dyne / cm ² ; Loss modulus = 3.8 × 10 ⁵ dyne / cm ² (both at 120 ° C.)).
[0046]
Place both sides of this sheet on clay-coated release paper (release paper 1), leave it in a 120 ° C. air-drying machine for 3 minutes to foam, and release both sides of the 1.00 mm thick foam sheet with release paper 1. A sandwiched sheet was obtained. When this sheet was aged at 40 ° C. for 24 hours, a foamed adhesive sheet having a thickness of 1.00 mm was obtained.
[0047]
Comparative Example 8
A foamed adhesive sheet was obtained in the same manner as in Example 4 except that the release paper 1 was not replaced. The thickness of the sheet immediately after foaming was 1.00 mm, but the thickness after aging for 24 hours was 0.68 mm.
[0048]
Example 5
To 25 g of syrup composed of 95 parts of 2-ethylhexyl acrylate, 5 parts of acrylic acid, 0.1 part of AIBN and 0.3 part of normal dodecyl mercaptan, 0.2 g of V-70 (manufactured by Wako Pure Chemical Industries, Ltd.) Then, a foamed microballoon (Expancel 551DE) was added as a foaming agent to a volume of 100 ml. This was coated on a 0.1 mm-exfoliated PET film using a doctor blade, sandwiched between the same PET films, and then polymerized and cured in a 70 ° C. blower dryer for 5 minutes to obtain a thickness of 0. An 80 mm sheet was obtained.
When both surfaces of this sheet were applied to release paper 1 and aged at 40 ° C. for 24 hours, a foamed adhesive sheet having a thickness of 0.80 mm was obtained.
[0049]
Comparative Example 9
A foamed adhesive sheet was obtained in the same manner as in Example 5 except that the release paper 1 was not replaced. The thickness of the sheet immediately after curing was 0.80 mm, but the thickness after aging for 24 hours was 0.63 mm.
[0050]
Example 6
Coated with a doctor blade on the heavy release surface of release paper (125Y-832 (IR / B); thickness 125μ; manufactured by Fujimori Kogyo Co., Ltd./release paper 1) with sufficient mixing of the following composition and clay coating did. It dried for 5 minutes in the 80 degreeC ventilation drying machine, and obtained the sheet-like thing of thickness 0.20mm. The obtained sheet-like product had a storage elastic modulus of 3.8 × 10 ⁵ dyne / cm ² and a loss elastic modulus of 2.2 × 10 ⁵ dyne / cm ² (both at 120 ° C.). The light release surface of release paper 1 is laminated on this sheet and left to stand in a blow dryer at 120 ° C. for 3 minutes for foaming. It was. When this sheet was aged at 40 ° C. for 24 hours, a foam sheet having a sheet thickness of 0.40 mm was obtained.
[0051]
( Composition )
SK Dyne 1578 ^{* 1} 333 parts Expander DU-551 ^{* 2} 5 parts E-AX ^{* 3} 2 parts Note) * 1, * 2 and * 3 are the same as in Example 1.
[0052]
Example 7
The following composition was mixed thoroughly and applied on the surface of clay-coated release paper (WBF 90K-D; thickness 120μ; manufactured by Lintec Co., Ltd./Release paper 2) using a doctor blade and blown at 80 ° C. It was dried in a drier for 5 minutes to obtain a sheet-like material having a thickness of 0.50 mm. The sheet-like material obtained had a storage elastic modulus of 5.2 × 10 ⁵ dyne / cm ² and a loss elastic modulus of 2.8 × 10 ⁵ dyne / cm ² (both at 120 ° C.). The light release surface of release paper 1 is laminated on this sheet and left to stand in a blow dryer at 120 ° C. for 3 minutes for foaming to obtain a sheet in which both sides of a 2.55-mm thick foam sheet are sandwiched with release paper 1 It was. When this sheet was aged at 40 ° C. for 24 hours, a foam sheet having a sheet thickness of 2.55 mm was obtained.
[0053]
( Composition )
SK Dyne 1578 ^{* 1} 333 parts Expander DU-551 ^{* 2} 15 parts E-AX ^{* 3} 2 parts Note) * 1, * 2 and * 3 are the same as in Example 1.
[0054]
Comparative Example 10
A foamed pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the release paper of Example 6 was changed to MDPE-coated release paper (WEW80KB-BX; thickness 125 μ; manufactured by Lintec Corporation / Release paper 3). The thickness of the sheet immediately after foaming was 0.40 mm, but the thickness after 24 hours was 0.33 mm.
[0055]
Comparative Example 11
A foamed adhesive sheet was obtained in the same manner as in Example 1 except that the release paper of Example 7 was changed to glassine release paper (GW-702A; thickness 65 μ; manufactured by Lintec Co., Ltd./Release paper 4). The thickness of the sheet immediately after foaming was 2.50 mm, but the thickness after 24 hours was 1.89 mm.
[0056]
Example 8
SK Dyne 1604S (manufactured by Soken Chemical Co., Ltd.), which is an acrylic adhesive, was transferred to both sides of the foamed sheet prepared in Example 3 so that the adhesive layer had a thickness of 30 μm, and a double-sided adhesive sheet was produced. did. The appearance and adhesive performance of this product were good.
[0057]
Comparative Example 12
SK Dyne 1604S (manufactured by Soken Chemical Co., Ltd.), which is an acrylic adhesive, was transferred to both surfaces of the foamed sheet prepared in Comparative Example 7 so that the adhesive layer had a thickness of 30 μm, and a double-sided adhesive sheet was prepared. did. This product had a poor adhesion between the foamed sheet and the pressure-sensitive adhesive layer due to the unevenness of the sheet due to the thinness of the roll, and had a large variation in adhesive performance.
more than

Claims (8)

A resin having a storage elastic modulus and a loss elastic modulus at 120 ° C. of 10 ⁹ dyne / cm ² or less and a thickness of 0.2 to 3 mm, including hollow spheres obtained by expanding and foaming thermally expandable resin particles Foamed sheets in which volume reduction obtained by aging after bonding the composition layer to release paper using inorganic powder-coated paper and aging is suppressed.   The foamed sheet with suppressed volume reduction according to claim 1, wherein the resin composition layer is mainly composed of a (meth) acrylic ester resin. The foamed sheet with suppressed volume reduction according to claim 1 or 2, wherein the resin composition layer has a storage elastic modulus and a loss elastic modulus at 120 ° C of 10 ⁴ dyne / cm ² or more.   The foamed sheet with suppressed volume reduction according to any one of claims 1 to 3, wherein the resin composition layer is an adhesive resin composition layer.   The foaming adhesive sheet which suppressed the volume reduction | decrease which provides an adhesive layer in the at least single side | surface of the foaming sheet in any one of Claim 1 thru | or 4.   The foamed sheet with suppressed volume reduction according to any one of claims 1 to 5, wherein the volume is not substantially reduced by aging at 40 ° C for 24 hours. A resin composition containing a thermally expandable resin particle and having a storage elastic modulus at 120 ° C. and a loss elastic modulus of 10 ⁹ dyne / cm ² or less is applied to a release paper using inorganic powder-coated paper to a thickness of 0.2 to 3 mm. after coated, drying it so as to be, have row heat foaming treatment, the method of manufacturing a sparkling sheets which suppresses volume reduction, characterized in that aged them. Hollow spheres obtained by expanding and foaming thermally expandable resin particles are mixed in a resin composition having a storage elastic modulus and a loss elastic modulus at 120 ° C. of 10 ⁹ dyne / cm ² or less, and this is coated with an inorganic powder coating The manufacturing method of the foam sheet which suppressed volume reduction characterized by apply | coating to the release paper using paper so that the thickness of a resin composition may be 0.2-3 mm, and ripening this.