KR940010828B1 - Pressure-sensitive adhesive tape and producing method thereof - Google Patents

Abstract

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Description

Pressure-sensitive adhesive tape and method for manufacturing same

The present invention relates to a pressure-sensitive adhesive tape containing a microbubble in an adhesive layer and a method for manufacturing the same, as taught in US Pat. No. 4,223,067.

Pressure-sensitive adhesive tapes with foamed backs are often used to adhere articles to substrates. The foamed back of these tapes are often dyed with carbon black to mask their presence.

U.S. Patent No. 4,223,067 discloses pressure sensitive adhesive tapes that, although not foams, have similar appearance and properties to foams and are useful for applications where a foamed pressure sensitive adhesive tape has previously been foamed. The foam-like tape of the patent, which is currently commercially available, is prepared by polymerizing an adhesive-forming mixture layer comprising colorless glass microbubbles by ultraviolet light, wherein the microbubbles block sunlight or form a molding on the vehicle side. It provides a white color which makes the tape undesirably visible in applications such as attaching or attaching decorative gratings to glass windows. However, the foam-like tapes of this patent are often preferred for back-foamable tapes for this purpose because of their good performance, and will be more useful when the adhesive layer of the tape is dark enough to conceal the tape. When carbon black or other dye is added to the photopolymerizable adhesive-forming mixture, preferably in an amount sufficient to provide a dark appearance, the mixture is prevented from polymerizing into a pressure-sensitive adhesive by ultraviolet light. When using less than about 0.1 or 0.15% by weight of carbon black, the polymerization of the 1 mm thick layer was hardly hindered, but this would result in a pastel gray colour, which is visually undesirable for most applications such as those mentioned above.

As glass microbubbles are also used as fillers for other polymeric articles, they have the advantage of providing a lighter weight in addition to the advantages provided by other inert fillers (eg, high deformation temperatures). Light weight is particularly important for automotive parts. The vehicle parts must be colored internally and effectively masked so that the structure covered by the microbubbles is not visible.

The present invention relates, among other things, to pressure-sensitive adhesive tapes that are equivalent in performance to the tapes of US Pat. No. 4,223,067 (hereinafter referred to as "'067 tapes") and have a sufficiently dark appearance to meet the above-mentioned requirements. Like the 067 tape, the pressure-sensitive adhesive tape of the present invention preferably has a thickness of more than 0.2 mm and an average density whose main component does not exceed 1.0 g / cm ³ with the polymer pressure-sensitive adhesive matrix (ASTM D-2840-69). It includes a pressure-sensitive adhesive layer which is a glass microbubble having a microbubble is completely dispersed and constitutes at least 5% by volume of the adhesive layer. Also, as in the '067 tape, the adhesive is preferably polymerized by ultraviolet light.

The tape of the present invention differs from the '067 tape in the following respects:

(1) glass colored with microbubbles (that is, glass colored with a metal oxide), wherein the glass preferably has an ultraviolet window and a dark color; (2) The dark dye or pigment is completely dispersed throughout the adhesive matrix. Dark colored glass microbubbles in an amount sufficient to effect ultraviolet polymerization cannot by themselves provide a '067 tape' appearance that is sufficiently dark for most applications. Dark colored pigments or dyes, by themselves, cannot provide UV-polymerized '067 tapes that are dark enough for most applications. However, mixing dark pigmented-glass microbubbles with dark pigments or dyes provides a considerably darker appearance without disturbing the polymerization of the adhesive matrix, even under self-righteous exposures used in the preferred examples of tapes reported in US Pat. No. 4,223,067. can do.

More broadly, the invention relates to an adhesive article comprising a matrix filled with colored-glass microbubbles, wherein the glass microbubbles comprise at least 5% by volume of the article. This article of the invention differs from conventional articles such that the pressure sensitive adhesive tapes of the invention differ from '067 tapes.

In addition, the colored-glass microbubbles themselves are novel, especially when the glass has an ultraviolet window capable of inserting microbubbles into the matrix to be photopolymerized. In the absence of any pigments or dyes, colored-glass microbubbles provide a fairly effective opacity.

Glass microbubbles can be prepared according to US Pat. No. 3,365,315 or 4,391,646, but all metal oxides used in the preparation of the above patents produce colorless microbubbles. In order to obtain colored-glass microbubbles, it is necessary to use colored metal oxides. In order to insert colored-glass microbubbles into the matrix to be photopolymerized, it is desirable for the metal oxide to provide an ultraviolet window, such as cobalt or nickel oxide.

The average diameter of the colored-glass microbubbles of the present invention should be 5 to 200 μm. Colored-glass microbubbles with an average diameter of 5 μm or less tend to be very expensive. In producing the tape of the present invention, it is difficult to coat with a photopolymerizable mixture containing micro bubbles having an average diameter of 200 µm or more. For economical manufacturing, the average diameter of the colored-glass microbubbles is preferably 20 to 80 µm.

The colored-glass microbubbles may comprise 5 to 65% by volume of the pressure sensitive adhesive layer or other article of the invention. If the glass microbubble is 65 vol% or more, it is very difficult to produce an adhesive uniform article, while if it is less than 5 vol%, the advantages of using colored glass microbubbles are hardly realized. It is preferable that 10 to 55% by volume of the pressure-sensitive adhesive layer or other article is made of colored glass microbubbles.

The thickness of the pressure-sensitive adhesive layer or other article of the present invention should be at least three times the average diameter of the microbubbles and more than twice the diameter of almost all the microbubbles. Such flexible articles, such as the pressure-sensitive adhesive microbubbles of the present invention, are not broken under pressure and the colored-glass microbubbles are well inserted into the matrix. The tape of the present invention retains foam properties while allowing the adhesive to be in full contact with a surface that is not rough or flat. Optimum performance in this respect is obtained when the thickness of the pressure-sensitive adhesive layer or other article exceeds 7 times the average diameter of the colored-glass microbubbles.

As taught in the aforementioned '067 patent, the microbubble-filled adhesive layers of the tapes of the present invention can be economically produced in thicknesses as thin as 0.1 mm and as thick as 2.5 mm or more. When the thickness of the adhesive layer exceeds 1.0 mm, it is preferable to coat the microbubble-filled photopolymerizable monomer on a carrier through which ultraviolet rays pass so that both coating surfaces are irradiated with ultraviolet rays. These tapes are most useful when the adhesive thickness is 0.4 to 1.0 mm.

The '067 patent teaches that the walls of glass microbubbles should be very thin, but at present it is difficult to produce colored-glass microbubbles with an average density of about 0.2 g / cm ³ or less. However, in terms of economics as well as easily disperse the micro bubbles in the adhesive production monomer, the average density is preferably less than 0.4g / cm ³ , preferably less than 0.3g / cm ³ .

The teachings of US Pat. No. 4,415,615, in which the tape of the '067 patent may have a foamy pressure-sensitive adhesive matrix, are also applicable in the manufacture of the tape of the present invention (see column 5, paragraphs 32-47 and Example 25). The tape of the present invention, wherein the adhesive layer comprises colored-glass microbubbles in the foam adhesive matrix, has almost the same darkness as the same tape except that it has a dense adhesive matrix.

Preferred pigments are carbon blacks, amounts of from about 0.04 to 0.15% by weight of the matrix excluding colored-glass microbubbles are useful. Preferred dyes are crystal violets, which have ultraviolet windows of 340-420 nm. An amount thereof is also useful in the range of about 0.04 to 0.15% by weight of the matrix. Preferably the amount of pigment or dye does not exceed 0.12% by weight of the matrix.

The matrix of the pressure-sensitive adhesive tape of the present invention preferably comprises an acrylic polymer of an acrylic ester of a non-tertiary alcohol whose molecules have 1 to 14 carbon atoms. Most of these molecules have C ₄ -C ₁₂ carbon-carbon chains which terminate at hydroxyl oxygen atoms. The chain contains at least about 1/2 carbon atoms of the total number of carbon atoms in the molecule. The acrylic esters can themselves polymerize into adhesive, stretchable, elastic adhesive polymeric materials.

To enhance the internal strength of the adhesive matrix, the acrylic polymer may be acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, N-substituted acrylamide, acrylonitrile, methacrylonitrile, hydroxyalkylacrylate. And cyanoethyl acrylate, N-vinylpyrrolidone, and copolymers of acrylic esters with one or more copolymerizable monoethylenically unsaturated monomers having significant polar groups such as those present in maleic anhydride. Generally, the copolymerizable monomer should be used in an amount of less than 20% by weight of the adhesive matrix so that the adhesive is tacky at room temperature, provided that the adhesion can be maintained when the N-vinylpyrrolidone content is 50% by weight or less. . When the amount of such copolymerizable monomer is large, it is necessary to heat in order to give adhesiveness and pressure-sensitive property to the adhesive matrix of the new tape. The adhesive matrix may also contain small amounts of other useful copolymerizable mono ethylenically unsaturated monomers such as alkyl vinyl ethers, vinylidene chloride, styrene, and vinyltoluene.

To further improve the adhesive strength, crosslinking agents, such as 1,6-hexanediol diacrylate, photoactive crosslinking agents such as those taught in US Pat. Nos. 4,330,590 and 4,329,384, or C _{1-4 in} the preparation of the adhesive matrix Lower-alkoxylated amino formaldehyde condensates with alkyl groups, for example hexamethoxymethyl melamine (commercially available as "Cymel" 303 from American Cyanamide Company) or detramethoxymethyl urea (from American Cyanamide Company) Heat-active crosslinkers such as Beetle "65) or tetrabutoxymethyl urea (" Beetle "85) may be added.

When tempering the tape of the invention via photopolymerization as taught in the above-mentioned '067 patent, it is possible to add partially colored glass microbubbles after partially polymerizing the photopolymerizable monomer to a coatable viscosity of about 1 to 40 Pa · s cps. Can be. Moreover, it can also partially polymerize with heat. In order to be easy to handle, the viscosity within 5-15 Pa.s is preferable. The monomer may be mixed with a thixotropic agent, such as fumed silica, instead of partial polymerization, followed by coating and photopolymerization. Regardless of the technique used to form coatable viscosities, it is desirable to uniformly disperse the microbubbles by stirring and immediately coating the mixture after storage.

The microbubble-comprising matrix can be coated and polymerized onto a flexible back sheet having a low-adhesive surface that is readily removable and almost permanently self-supporting. If the non-notched side of the back sheet has a low-adhesive surface, the back sheet with the polymerized layer may be rolled up in a roll to facilitate storage and shipping.

In the state of the art, it is preferable to carry out the photopolymerization reaction under an inert atmosphere such as nitrogen. The inert atmosphere can be achieved by temporarily covering the photopolymerizable coating with a plastic film through which ultraviolet light passes and irradiating the film in air. If the polymerizable gout is not covered during the photopolymerization reaction, the oxidizable tin compound may be mixed with the photopolymerizable composition to increase the permeable oxygen content in the inert atmosphere as described in US Pat. No. 4,303,485. The patent also teaches that, in doing so, thick coatings can be polymerized in the atmosphere.

When the tape of the present invention is attached to a surface on which the pressure-sensitive adhesive layer does not form a strong bond, one or both sides of the microbubble-layer preadhesive layer, that is, a non-filled pressure-sensitive adhesive layer specially selected to adhere to the surface May be desirable.

The following test is for evaluating the tape of the present invention.

Shear value

The piece of tape is attached to the hard stainless steel sheet with exactly 1.27 cm ^{2 of} tape in contact with the panel by its own adhesive. Before testing, 1000 g of weight is hung on the coupling site for 15 minutes. The panel with the adhesive tape is then placed in an oven preheated to 70 ° C. and after 15 minutes a 500 g weight is attached to the free end of the tape, which is tilted 2 ° from the vertical to protect it from all peel force. The additional falling time is the shear value. If not failed, the test continues for nearly 10,000 minutes. Only sticky defects are recorded.

[T-peel value]

T-peel was measured according to ASTM D-1876-72, but the test tape was 1.27 cm wide and adhered to the back of aluminum foil and tested after exactly 2 hours. The measurement results are reported in Newtons (N / dm) per decimeter. Only sticky defects are recorded.

[Darkness]

The darkness of the pressure-sensitive adhesive layer has a reflectance of 10 °, an illumination of F and a CIE wrap scale (L ^* a ^* b ^* , where L ^* is 0 means black and L ^* 100 means white). It is measured using a Hunter LabScan Spectrocolorimeter. a ^* and b ^* are usually -5 to +5, so these values are not recorded if one of them is outside the above range.

[Production of Colored-Glass Microbubbles]

Many glasses were prepared by mixing the components specified in Table 1 below. Each mixture was dissolved in the furnace's refractory vessel at the temperatures and times specified in Table II below. The molten mixture was quenched in water to give a frit that was collected from water and dried. 500 g of frit samples were ground with 6,000 g of alumina abrasive media for 1 hour 30 minutes. This milled material was sorted to produce "feed" particles with a typical size distribution of 90% (per weight) up to 65 μm, 50% up to 30 μm, and 10% up to 10 μm. Particle size was measured using a Leads and Northrup Microtrac particle size analyzer, model 2991-01.

The "feed" particles were made into microbubbles by passing the particles through an air / gas flame (stoichiometry of about 10: 1) at the rate specified in Table 2 below. Product yields and densities are also reported in Table 2 below.

TABLE 1

* Also contains 0.86NaNO3

TABLE 2

Color-Glass L was treated the same as A-K, but only solid microspheres were formed.

The average density of the colored-glass microbubbles A was 0.38 g / cm ^3, but 76 wt% of the particles had a density of less than 1.0 g / cm ³ , and the remaining 24 wt% was 1.0 g / cm ³ or more. Although not measured, the density distribution of each of the colored-glass microbubbles B-1 and K was almost the same as that of the colored-glass microbubbles A. The density distributions of the two batches of uncolored microbubbles used to prepare the colored-glass microbubbles A, J, and the comparative tape are shown in Table III below.

TABLE 3

In the following examples, only the floating part of the colored-glass microbubbles J was used, and the density of the part was 0.61.

The light transmittance of the glass of colored-glass microbubbles C and G was measured with broken pieces of large glass bubbles having an average thickness of about 0.2 mm. The measurement results are shown in Table IV below.

TABLE 4

In the examples below, all parts are values by weight.

Example 1

Coatable by partially polymerizing a mixture of 87.5 parts isooctyl acrylate, 12.5 parts acrylic acid and 0.04 parts 2,2-dimethoxy-2-phenylacetphenone ("Irgacure" 651) as taught in US Pat. No. 4,330,590 A syrup of viscosity was prepared. To the syrup was added 0.1 parts of '' Irgacure '' 651 and 0.05 parts of hexanediol diacrylate, together with free microbubbles and carbon black pigments, carbon black which was sprayed on isobonyl acrylate (available from Pencolor). The carbon black solids are shown in Table IV as a percentage of the weight of the adhesive matrix The resulting mixture was slowly and thoroughly mixed with an air-stirrer and then carefully degassed in the desiccator using a vacuum pump. .

To prepare each tape of Example 1, the mixture is injected into a knife coater nip between a pair of transparent bi-oriented polyethylene terephthalate films, the interface having a low-adhesive coating: the knife coater is a coating The thickness is adjusted to be about 0.10 to 0.12 mm. The resulting composite from the roll coater is exposed to the lampbank, where 90% of the lamp radiation is between 300 and 400 mm and the maximum is at 351 nm. The dosage was measured by International Light's "Light Bug", which is in the spectrally reactive 250-430 nm range with a maximum of 350 nm. Air was blown into both films during the irradiation to cool the composite, thereby keeping the film temperature below 85 ° C. to prevent shrinkage of the film.

The resulting tape was tested as described in Table V, with the percentage of microbubbles expressed in weight percent and volume percent.

The T-peel value of the tape 12 is greater than the T-peel value of the tape 5, which is presumably because the carbon black content hardens as it interferes with ultraviolet irradiation.

TABLE 5

a total exposure (exposure dose on one side)

b Survey the amount reported on each side

c a * =-0.3: b * =-10

d a * = 0.0: b * = -10.5

e a * =-0.3b: b * =-14

f a * = 0.6: b * =-11

g a * =-0.4: b * =-10

h a * = 0.0: b * =-14

i a * = 3.2: b * =-26

j a * =-3.3: b * = 13

k a * = 9.4: b * =-40

m a * =-1.8: b * =-12

n a * = 5.1: b * =-10

p a * = 7.2: b * =-13

AF adhesion defect

[Tape 27]

A pressure-sensitive adhesive tape was prepared using the same uncolored microbubbles as in tape 2, except that the amount of bubbles was 7.0% by weight and red pigment instead of carbon black, i.e. PDI red # 3593 (polyester having an average molecular weight of 250) Added as 15% solids in water).

[Tape 28]

Tape 28 was prepared identically to tape 27 except that colored-glass microbubbles 1 were used instead of non-colored microbubbles.

[Tape 29-30]

The tape 29-30 used floating portions of colored-glass microbubbles J (density = 0.61 g / cm ³ ), which differ from the tapes in that the ratio of isooctyl acrylate to acrylic acid is 90:10.

[Tape 31]

Tape 31 was prepared the same as Tape 1 except that 0.1% of the crystal violet dye was contained in the adhesive matrix.

[Tape 32]

Tape 32 was prepared in the same manner as in tape 10 except that it contained 0.1% of crystal violet dye instead of carbon black.

[Tape 33]

Tape 33 uses 8.0% by weight colored-glass microbubbles C, 0.091% carbon black, and 0.75% surfactant C and 1.0% surfactant B (see bottom of column 7 of US Pat. No. 4,415,615). Except that was prepared in the same manner as the tape 9. The unpolymerized adhesive mixture was polymerized after foaming according to the "general tape making process" described in column 6 of the patent. The resulting tape includes an adhesive layer comprising colored glass microbubbles dispersed in a foamy pressure-sensitive adhesive tape. The foam adhesive layer has the expected foaming properties and has a density of 560kg / cm 酎.

[Tape 34]

After exposing one of the transparent films of tape 33 to expose the foam adhesive layer, a non-bubble pressure-sensitive adhesive transfer tape was laminated to the foam layer using a hard rubber roller. The adhesive transfer tape was a pressure sensitive acrylate copolymer adhesive of the kind specified in US Pat. No. 24,906. The thickness was 0.05 mm. This two layer adhesive tape product was tested for a degree of peeling at 180 ° ^* as follows: 141 N / dm for non-aerated surface; 103 N / dm.

week

*: Peeling degree from stainless steel sheet at 180 ° measured by attaching the free end of the tape to the balance and pulling the stainless steel sheet from the balance at about 3.8 cm / sec.

Tape 35

70 parts of isooctyl acrylite, 30 parts of N-vinyl-pyrrolidone, and 0.04 parts of 2,2-dimethoxy-2-phenyl acetofe ("Irgacure" 651) were prepared by partially polymerizing a mixture of Syrup was prepared. To this syrup was added 0.1 part "Irgacure" 651,0.05 parts hexanediol diacrylate, 7.25 parts colored-glass microbubbles B, and 0.043 parts carbon black pigment. This syrup was coated and polymerized as described on tape 1.

Test results for tapes 27-33 and 35 are described in Table VI below.

Table VI

q a * = 43: b * = 19

r a * = 31: b * = 15

s a * = -4: b * = 17

t a * = 22: b * =-53

u a * = 15: b * =-42

v a * =-0.4: b * =-11

Colored-glass microbubbles useful as pigments

The adhesive layers of tapes 21-25 and 27-29 do not have a dense appearance and therefore do not hide the presence of the tape in most of the applications described above. However, the color of the tapes gives aesthetic satisfaction, and each of these tapes can hide its presence as possible when attached to a surface that is elegant and of the same color or complementary color.

U.S. Patent No. 4,391,646 mentioned above describes that glass microbubbles can be easily dispersed uniformly in plastic by extraction or injection molding (see column 8, lines 19-31). The patent also demonstrates that glass microbubbles made of colored glass can easily be uniformly dispersed in the adhesive layer of the pressure-sensitive adhesive tape, and tapes 21-25 and 27-29, when used, are colored-glass micro Bubbles have been shown to have an aesthetic effect. Colored-glass microbubbles can be dispersed as pigments in many additives such as rubbers and other thermoplastics such as polyurethane, polyfluoroprene, polyethylene, alkyds and other paint media, epoxy resins and other thermosetting materials. The comparative test below shows that colored-glass microbubbles provide significantly better opacity or hiding power when dispersed as pigments throughout an article of normal transparency made of a material as mentioned in the paragraph above. For example, colored-glass microbubbles not only provide aesthetic color and good opacity to plastic vehicle body parts (such as shock absorbers and doors) but also significantly reduce the weight of the car body. Colored-glass microbubbles can reduce costs because they are much cheaper on a volume basis than many widely used materials on which they can be dispersed.

Currently, compared to many pigments on the market, colored-glass microbubbles have the advantage of being completely inert and can therefore be used in significant acidic or basic pigment materials. Articles and coatings colored with colored-glass microbubbles will retain their original color even with prolonged weathering as long as the quality of the article or coating material itself is not degraded.

The metal oxides used to make the glass capable of forming colored-glass microbubbles have the colors indicated below:

Cobalt blue

Nickel tan

Manganese pink

Chrome green

Vanadium tan

Copper green

Cadmium yellow

Selenium-cadmium orange

Reference: D.C. Void and D.A. Thompson's chemical technology book, Glass, (vol. 11, 3rd edition, published by Kirk Otmer, John Wally and Sond, p.845).

[Comparison Test]

The colored-glass microbubbles K were screened through a 200-mesh screen (holes with a diameter of 74-μm) so that the average diameter was similar to the diameter of the solid glass microspheres L as follows:

These were each used to make a tape as in Example 1, but were treated several times with a manual homogenizer before coding the filled syrup to eliminate the tendency of solid glass microspheres L to agglomerate. The properties of the adhesive layer of the resulting tape were as follows:

When the four tapes were placed on a typed sheet (covered on both sides of the polyester film), the typed letters could be read through a tape containing solid microspheres, but almost unreadable through tape 38. The tape 37 showed only the outlines of the letters, demonstrating that the colored-glass microbubbles have a good hiding power. When viewed through tape 36, the letters appeared somewhat clearer than when viewed through a tape made of solid glass microspheres L.

Example 2

Colored-glass microbubbles A (5.8 g) were dry-mixed with low viscosity linear polyethylene (58 g: Union Carbide 7047) with a melt index of 1. The mixture was extruded through a hole of 6.35 mm diameter at a pressure of 10341 kPa and a temperature of 193 ° C. (inlet) and 221 ° C. (outlet). This resulted in an opaque flexible rod with a density of 0.845 g / cm ³ and uniform cobalt blue.

Example 3

To 10 g of isocyanate prepolymer (“HypoI 3000” of WR Grace) was added 10 g of tap water containing 1 g of colored-glass microbubbles C. It was stirred by hand at room temperature until bubbles formed, during which the microbubbles were completely dispersed, evidenced by a uniform blue-blue color.

Example 4

A mixture of 70 parts isooctyl acrylate, 30 parts acrylic acid and 0.04 parts 2,2-dimethoxy-2-phenyl acetophenone ("Irgacure" 651) was partially polymerized to prepare a syrup of coatable viscosity. To the syrup was added 0.1 parts '' Irgacure '' 651, 0.05 parts hexanedioldiacrylate, and 7 parts colored-glass microbubbles B. This syrup was subjected to the same method as in the adhesive layer of the tape of Example 1 above. As the transparent film was peeled off, the brittle, inviscid viscosity of light blue (L ^* = 37, a ^* = 13, b ^* =-36) with a thickness of 1.1 mm and a density of 0.084 g / cm ³ Plastic film was produced.

Example 5

A syrup was prepared according to the method of Example 4, except that 0.072 parts of carbon black was included. The syrup was polymerized to yield a black (L ^* = 26) brittle, non-viscous plastic film with a thickness of 1 mm and a density of 0.085 g / cm ³ .

Example 6

10 g of hydroxy-functional polyol (“Lexorez 3500-140” of Innotek) was mixed with 1.5 g of colored-glass microbubbles B, followed by 5 g of isocyanate prepolymer (MoBuy Chemical Co., Ltd. “Desmodur N- 100 ") and 0.005 parts of dibutyl corner dilaurylate were mixed. This was poured into a Petri dish, degassed and cured in an oven at 170 ° C. for 15 minutes to give a light blue color of about 3 mm thick and 0.61 g / cm ³ density (L ^* = 35, a ^* = 12, b ^* =- A tough rubber sheet of 34) was obtained.

Example 7

1 part colored-glass microbubble B was mixed with 20 parts lacquer (20% solids: "Floquill" crystal coating) which dried on its own smooth finish. The mixture was painted on aluminum surface and then dried to give an opaque blue-blue color.

Claims (6)

The matrix comprises a pressure-sensitive adhesive layer whose main component is a pressure-sensitive adhesive comprising an acrylic polymer of acrylic acid of a non-tertiary alcohol, wherein the molecules of the polymer have 1 to] 4 carbon atoms, and most of the molecules are at least Has a C ₄ -C ₁₂ carbon-to-carbon chain terminated at a hydroxyl oxygen atom, the chain comprising at least half carbon atoms of the total number of carbon atoms in the molecule, the acrylic esters being self-adhesive, extensible A pressure-sensitive adhesive that can be polymerized with an elastic adhesive polymer material, the average density of the glass microbubbles is 1.0 g / cc or less, microbubbles are dispersed throughout the adhesive layer, and constitute 5 vol% or more of the adhesive layer. In the tape, the microbubbles are colored glass having an average diameter of 5 to 200 m, and the dyes or pigments constituting 0.04 to 0.12% of the adhesive matrix Pressure-sensitive adhesive tape, characterized in that dispersed throughout the adhesive matrix The pressure sensitive adhesive tape of claim 1, wherein the pressure sensitive adhesive tape has a flexible backsheet with a low adhesive surface that can be easily removed. The pressure-sensitive adhesive tape of claim 2, wherein the pressure-sensitive adhesive layer has a foamy pressure-sensitive adhesive matrix. 3. The pressure-sensitive adhesive tape of claim 2, wherein the uncoated side of the backsheet has a low-adhesive surface and the tape itself is wound in a roll. The pressure-sensitive adhesive tape of claim 2, comprising a pressure-sensitive adhesive layer unfilled on at least one side of the microbubble-filled adhesive layer. (1) mixing the glass microbubbles with an average density of 1.0 g / cc or less and the photopolymerizable monomer together, wherein the microbubbles constitute 5 vol% or more of the mixture; (2) coating the mixture onto a backsheet; And (3) photopolymerizing the monomer in a pressure-sensitive adhesive state by irradiating the coating with ultraviolet light, the method of producing the pressure-sensitive adhesive tape of any one of claims 1 to 5, wherein the minute A bubble is colored glass, and the pigment or dye is disperse | distributed to the whole photopolymerizable monomer, The method characterized by the above-mentioned.