JP6294727B2 - Adhesive, double-sided adhesive tape or sheet to which the adhesive is applied - Google Patents

Description

  The present invention is a double-sided pressure-sensitive adhesive tape or sheet that can be disaggregated in a paper recycling process, has an excellent balance between tack and holding power, and can be prevented from peeling off from an adherend when a poster or the like is attached to a vertical surface; It is related with the adhesive used for these.

  Double-sided tape is used to seal envelopes and attach posters to walls. In recent years, for the purpose of effectively utilizing pulp resources, paper product waste to which a double-sided tape is attached has been recycled for pulp regeneration. At this time, when the pulp is recycled from the waste of the paper product to which the double-sided tape is attached, the adhesive used for the double-sided tape may inhibit the releasability of the recycled pulp.

  In order to solve this problem, Patent Document 1 proposes an adhesive that can be disaggregated. Specifically, the pressure-sensitive adhesive proposed in Patent Document 1 has a (meth) acrylic acid ester copolymer having a unit content based on (meth) acrylic acid of 5% by mass or more, and a softening point. It contains a tackifier at 140 ° C. or higher, and the self-adhesive strength between the pressure-sensitive adhesive layers is 5.0 N / 25 mm or more.

JP 2004-271667 A

  However, the pressure-sensitive adhesive according to Patent Document 1 is hardened and the tack is lowered, and the usability as a double-sided pressure-sensitive adhesive tape may be inferior (particularly, when a poster or the like is attached to a vertical surface, May peel off). Therefore, the present invention is a double-sided pressure-sensitive adhesive tape that can be disaggregated in a paper recycling process, has an excellent balance between tack and holding force, and can be prevented from peeling off from an adherend when a poster or the like is attached to a vertical surface. It is an object to provide a sheet and a pressure-sensitive adhesive used for these.

Means for Solving the Invention

The present invention relates to a pressure-sensitive adhesive composition comprising a copolymer obtained by emulsion polymerization of the following components (a), (b), (c) and (d) and having a theoretical glass transition temperature of −20 ° C. or lower. And an emulsion resin containing at least an emulsion resin having a softening point of 120 ° C. or higher.
(A) at least one (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms other than the (meth) acryloyl group, based on the total mass of the components (a) to (d), 65. 5-85.5% by mass
(B) At least one (meth) acrylic acid alkoxyalkyl ester having 2 to 30 carbon atoms other than the (meth) acryloyl group and 3 to 50 carbon atoms other than the (meth) acryloyl group ( (Meth) acrylic acid alkoxy (poly) alkylene glycol ester, containing a hydroxyl group, containing (meth) acrylic acid ester having 1 to 50 carbon atoms other than (meth) acryloyl group, and / or containing a carboxyl group The (meth) acrylic acid ester having 5 to 50 carbon atoms other than the (meth) acryloyl group is 3 to 8% by mass based on the total mass of the components (a) to (d).
(C) at least one (meth) acrylic acid and / or a carboxyl group-containing (meth) acrylic acid ester having 1 to 4 carbon atoms other than the (meth) acryloyl group, 3.5 to 6.5% by mass based on the total mass of a) to (d)
(D) 8-20% by weight of at least one vinyl ester monomer, based on the total weight of components (a)-(d)
Here, as for the monomer which concerns on the said component (a), T-30 of the polymer obtained by superposing | polymerizing this monomer may be -30 degrees C or less.
Further, the monomer according to the component (b) may have a Tg of 0 ° C. or less obtained by polymerizing the monomer.
In addition, the monomer according to the component (d) may have a polymer Tg of −40 ° C. or higher obtained by polymerizing the monomer.
Moreover, the said component (a) is 68-82.5 mass% on the basis of the total mass of components (a)-(d), and the said component (b) is component (a)-(d). Based on the total mass, it is 3.5 to 7.5% by mass, and the component (c) is 4 to 6.5% by mass based on the total mass of the components (a) to (d), The component (d) may be 10 to 18% by mass based on the total mass of the components (a) to (d).
Moreover, the said component (a) is 70-79.5 mass% on the basis of the total mass of components (a)-(d), and the said component (b) is component (a)-(d). 4-7 mass% based on the total mass, and the component (c) is 4.5-6 mass% based on the total mass of the components (a)-(d), and the component (d ) May be 12 to 16% by mass based on the total mass of the components (a) to (d).
Moreover, 3-30 mass parts of said emulsion resin (emulsion resin containing at least the emulsion resin with a softening point of 120 degreeC or more) may be mix | blended with respect to 100 mass parts of said adhesive compositions.
Moreover, the double-sided adhesive tape or sheet which has a base material and the said adhesive applied to both surfaces of the said base material may be sufficient.

  According to the present invention, a double-sided pressure-sensitive adhesive tape that can be disaggregated in a paper recycling process, has an excellent balance between tack and holding force, and can be prevented from peeling off from an adherend when a poster or the like is attached to a vertical surface, That is, it is possible to provide a double-sided pressure-sensitive adhesive tape or sheet having disaggregation properties and excellent practical properties such as poster display properties and a pressure-sensitive adhesive used in these.

The present invention relates to a pressure-sensitive adhesive composition comprising a copolymer obtained by emulsion polymerization of the following components (a), (b), (c) and (d) and having a theoretical glass transition temperature of −20 ° C. or lower. And an emulsion resin containing at least an emulsion resin having a softening point of 120 ° C. or higher.
(A) at least one (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms other than the (meth) acryloyl group, based on the total mass of the components (a) to (d), 65. 5-85.5% by mass
(B) At least one (meth) acrylic acid alkoxyalkyl ester having 2 to 30 carbon atoms other than the (meth) acryloyl group and 3 to 50 carbon atoms other than the (meth) acryloyl group ( (Meth) acrylic acid alkoxy (poly) alkylene glycol ester, containing a hydroxyl group, containing (meth) acrylic acid ester having 1 to 50 carbon atoms other than (meth) acryloyl group, and / or containing a carboxyl group The (meth) acrylic acid ester having 5 to 50 carbon atoms other than the (meth) acryloyl group is 3 to 8% by mass based on the total mass of the components (a) to (d).
(C) at least one (meth) acrylic acid and / or a carboxyl group-containing (meth) acrylic acid ester having 1 to 4 carbon atoms other than the (meth) acryloyl group, 3.5 to 6.5% by mass based on the total mass of a) to (d)
(D) 8-20% by weight of at least one vinyl ester monomer, based on the total weight of components (a)-(d)

  Hereinafter, the structural component, physical properties, production method and application of the pressure-sensitive adhesive according to the present invention will be described in detail.

≪Adhesive constituents≫
<Pressure-sensitive adhesive composition containing a copolymer obtained by emulsion polymerization>
The pressure-sensitive adhesive according to the present invention is a pressure-sensitive adhesive containing a copolymer having a theoretical glass transition temperature of −20 ° C. or lower, obtained by emulsion polymerization of the following components (a), (b), (c) and (d). Contains an agent composition. Hereinafter, each component (a)-(d) which is a raw material monomer, a compounding quantity, and a physical property are explained in full detail.

{component}
(Component (a))
The component (a) is at least one alkyl (meth) acrylate having 1 to 20 carbon atoms other than the (meth) acryloyl group. Here, the alkyl group of the (meth) acrylic acid alkyl ester (a) is not particularly limited, and those having 1 to 20 carbon atoms are used regardless of linear, branched or cyclic {preferably 2 carbon atoms To 18, more preferably 3 to 16 carbon atoms. For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-acrylate Octyl, isooctyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate, lauryl acrylate, isomyristyl acrylate, stearyl acrylate, isostearyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacrylic acid Isopropyl, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate Le, 2-ethylhexyl methacrylate, isononyl methacrylate, isodecyl methacrylate, decyl methacrylate, lauryl methacrylate, tridecyl methacrylate, and stearyl methacrylate. Among these, a particularly preferred monomer according to component (a) is a group consisting of n-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, n-nonyl acrylate and isononyl acrylate. At least one monomer selected from: From the viewpoint of physical properties, the monomer according to the preferred component (a) has a polymer Tg of −30 ° C. or lower (more preferably −40 ° C. or lower, more preferably −50) obtained by polymerizing the monomer. A monomer having a temperature of ℃ or less. Although a lower limit is not specifically limited, For example, it is -100 degreeC. Use of such a Tg component as component (a) is preferred because it can impart tack to the adhesive. Here, the glass transition temperature Tg in the present specification is a nominal value described in literatures (for example, polymer handbook, adhesive handbook, etc.), catalogs, and the like.

(Component (b))
Component (b) has at least one (meth) acrylic acid alkoxyalkyl ester having 2 to 30 carbon atoms other than the (meth) acryloyl group, and 3 to 50 carbon atoms other than the (meth) acryloyl group. (Meth) acrylic acid alkoxy (poly) alkylene glycol ester, (meth) acrylic acid ester having a hydroxyl group and having 1 to 50 carbon atoms other than (meth) acryloyl group, and / or carboxyl group (Meth) acrylic acid ester containing 5 to 50 carbon atoms other than the (meth) acryloyl group. Here, the alkyl part of “alkoxy” and the alkyl (alkylene) part of “ester” may be linear, branched or cyclic, as in component (a). Further, the number of carbon atoms of “alkoxy” and “alkyl” in the embodiment of “(meth) acrylic acid alkoxyalkyl ester” is not particularly limited, but is, for example, 1 to 29, respectively. Furthermore, the number of carbon atoms of “alkoxy” in the embodiment of “(meth) acrylic acid alkoxy (poly) alkylene glycol ester” is not particularly limited, but is, for example, 1 to 29, and the carbon of “(poly) alkylene glycol” The number of elements is not particularly limited, but is, for example, 2 to 49. Here, the reason for adding the component (b) is as follows. First, in order to express disaggregation which is the main effect of the present invention, it is necessary to add a large amount of component (c). However, when a large amount of component (c) is added, the tackiness of the pressure-sensitive adhesive decreases due to an increase in Tg, and the feeling of use as a pressure-sensitive adhesive tape is poor. Therefore, it is essential to include the component (b) as a monomer that does not affect the disaggregation and that has an effect of lowering (not increasing) the Tg of the whole polymer. Further, when the component (b) is used, the poster display property is remarkably increased. Here, specific examples of each component will be described. First, as the (meth) acrylic acid alkoxyalkyl ester having 2 to 30 carbon atoms other than the (meth) acryloyl group, 2-methoxyethyl acrylate (2- MTA) and 2-ethoxyethyl acrylate. Moreover, as (meth) acrylic acid alkoxy (poly) alkylene glycol ester having 3 to 50 carbon atoms other than the (meth) acryloyl group, an ethylene oxide adduct of (meth) acrylic acid, for example, methoxy acrylate- Examples thereof include triethylene glycol (MTGA) and methoxy-polyethylene glycol acrylate. Examples of the (meth) acrylic acid ester having 1 to 50 carbon atoms other than the (meth) acryloyl group containing a hydroxyl group include hydroxyethyl acrylate and 4-hydroxybutyl acrylate. Examples of the (meth) acrylic acid ester containing 5 to 50 carbon atoms other than the (meth) acryloyl group containing a carboxyl group include acrylic acid ω-carboxy-polycaprolactone and 2-acryloyloxyethyl succinic acid. Can be mentioned. From the viewpoint of physical properties, the monomer according to the preferred component (b) has a polymer Tg obtained by polymerizing the monomer of 0 ° C. or lower (more preferably −10 ° C. or lower, more preferably − 20 ° C. or lower). Although a lower limit is not specifically limited, For example, it is -100 degreeC. It is preferable to use a component having such a Tg as the component (b) because the tackiness of the pressure-sensitive adhesive is further increased.

(Component (c))
Component (c) is at least one (meth) acrylic acid ester containing (meth) acrylic acid and / or carboxyl group and having 1 to 4 carbon atoms other than (meth) acryloyl group. is there. Here, examples of the (meth) acrylic acid ester having 1 to 4 carbon atoms other than the (meth) acryloyl group containing a carboxyl group include 2-carboxyethyl acrylate. When component (c) is used, it works positively on disaggregation, which is the main effect of the present invention.

(Component (d))
Component (d) is at least one vinyl ester monomer. Component (d) is a monomer having a relatively high Tg, and has the effect of improving poster display properties. Here, examples of the vinyl ester monomer include vinyl acetate (VAc), vinyl propionate, and vinyl benzoate. From the viewpoint of physical properties, the monomer according to the preferred component (d) has a polymer Tg of −40 ° C. or higher (more preferably −20 ° C. or higher, more preferably, polymerized by polymerizing the monomer). 0 ° C. or higher). Although an upper limit is not specifically limited, For example, it is 100 degreeC. It is preferable to use a component having such a Tg as the component (d) because the poster display property is further improved.

{Blending amount}
(Component (a))
Component (a) is 65.5 to 85.5% by mass, preferably 68 to 82.5% by mass, more preferably, based on the total mass of components (a) to (d). It is 70-79.5 mass%. If the component (a) is too much, the cohesive strength of the pressure-sensitive adhesive will be insufficient, and the poster display will deteriorate. Moreover, when there are too few components (a), an adhesive will become hard too much and a tack will fall and the practical function as a double-sided tape will fall.

(Component (b))
Component (b) is 3 to 8% by mass, preferably 3.5 to 7.5% by mass, and more preferably 4 to 4% by mass, based on the total mass of components (a) to (d). 7% by mass. The reason why the amount is suitable is as follows. First, it is necessary to use a large amount of component (c) in order to express disaggregation. However, if the amount of component (c) is too large, Tg increases too much. When the amount of the component (b) is used, it can be realized that the disaggregation expression is not affected and the Tg of the whole polymer is lowered (not raised).

(Component (c))
Component (c) is 3.5 to 6.5% by mass, preferably 4 to 6.5% by mass, more preferably, based on the total mass of components (a) to (d). It is 4.5-6 mass%. When there are many components (c), it works positively on disintegration expression. On the other hand, when there are too many components (c), an adhesive will become hard and a tack will fall, the practical function as a double-sided tape will be inferior, and superposition | polymerization stability will fall.

(Component (d))
Component (d) is 8 to 20% by mass, preferably 10 to 18% by mass, more preferably 12 to 16% by mass, based on the total mass of components (a) to (d). is there. When the amount of the component (d) used is within this range, it becomes possible to appropriately increase the holding power of the pressure-sensitive adhesive (= improving poster display properties).

(Other monomer components)
As a raw material for the copolymer according to the present invention, as long as the above-mentioned components (a) to (d) are used in the aforementioned amounts, other monomer components may be used in combination {only components (a) to (d) It ’s okay}.

{Physical properties}
The theoretical glass transition temperature of the copolymer in the pressure-sensitive adhesive composition is −20 ° C. or lower, preferably −30 ° C. or lower, and more preferably −40 ° C. or lower. In addition, although a lower limit is not limited, For example, it is -100 degreeC. The use of such a Tg copolymer is preferable because an adhesive having an excellent balance between tack and cohesive force can be obtained. Here, the theoretical glass transition temperature (Tg) is calculated by the following formula using the glass transition temperature (° C.) (reference value) of the homopolymer of each component (weight fraction).
1 / Tg = W1 / Tg1 + W2 / Tg2 + ...
Tg: Glass transition temperature of copolymer Tg1: Glass transition temperature of homopolymer of monomer Tg1 constituting the copolymer (reference value)
W1: Weight fraction of monomer Tg1 constituting the copolymer Tg2: Glass transition temperature of homopolymer of monomer Tg2 constituting the copolymer (document values)
W2: The glass transition temperature of the weight fraction homopolymer of the monomer Tg2 constituting the copolymer is as follows (an example).
N-butyl acrylate -54 ° C
2-ethylhexyl acrylate -70 ° C
2-methoxyethyl acrylate -50 ° C
Vinyl acetate 32 ° C
Styrene 80 ℃
Acrylic acid 106 ℃

<Emulsion resin>
The emulsion resin according to the present invention is an emulsion resin containing at least an emulsion resin having a softening point of 120 ° C. or higher. Here, as an emulsion resin having a softening point of 120 ° C. or higher, rosin, polymerized rosin, polymerized rosin ester, rosin phenol, stabilized rosin ester, disproportionated rosin ester, terpene, terpene phenol, A petroleum resin system etc. can be illustrated. Of these, terpene phenol resins and rosin resins are preferred. Examples of the terpene phenol-based resin include Tamanol E-100 [manufactured by Arakawa Chemical Industry Co., Ltd.], Tamanol E-200 [manufactured by Arakawa Chemical Industry Co., Ltd.], Tamanol E-200NT [manufactured by Arakawa Chemical Industry Co., Ltd.], and the like. It is done. Examples of rosin resins include Harrier Star SK-508 [manufactured by Harima Kasei Co., Ltd.], Harrier Star SK-508H [manufactured by Harima Kasei Co., Ltd.], Harrier Star SK-816E [manufactured by Harima Kasei Co., Ltd.], Harrier Star SK-822E [Harima Kasei Co., Ltd.], Harrier Star SK-323NS [Harima Kasei Co., Ltd.], Super Ester E-650 [Arakawa Chemical Industries, Ltd.], Super Ester E-788 [Arakawa] Chemical Industry Co., Ltd.], Super Ester E-786-60 [Arakawa Chemical Industries, Ltd.], Super Ester E-865 [Arakawa Chemical Industries, Ltd.], Super Ester E-865NT [Arakawa Chemical Industries ( Etc.].
{component}

{Physical properties}
The softening point of the essential at least one emulsion resin used in the present invention is 120 ° C. or higher, preferably 130 ° C. or higher, and more preferably 140 ° C. or higher. Although an upper limit is not specifically limited, For example, it is 200 degreeC. By using an emulsion resin having such a softening point, it is possible to improve poster display performance. Here, the “softening point” is a value measured based on a softening point test method 320 (ring ball method) defined in JIS K 5902 and JIS K 2207.

≪Method for producing adhesive≫
The pressure-sensitive adhesive according to the present invention can be prepared, for example, by blending and kneading the emulsion resin in a pressure-sensitive adhesive composition containing the above-described copolymer. Here, with respect to the blending ratio of the emulsion resin to the pressure-sensitive adhesive composition, it is preferable to use 30% or more of at least one emulsion resin having a softening point of 120 ° C. or more in the total amount of the emulsion resin, and 40% It is more preferable to use the above, and it is more preferable to use 50% or more. Further, regarding the blending amount of the emulsion resin with respect to the pressure-sensitive adhesive composition, it is preferable to blend 3 to 30 parts by weight of the emulsion resin with respect to 100 parts by weight of the pressure-sensitive adhesive composition containing the copolymer. It is more preferable to mix 5 to 28 parts by mass, and it is more preferable to mix 7 to 26 parts by mass. When the emulsion resin is blended so as to fall within the range, poster display properties can be improved. The above-mentioned copolymer can be obtained by polymerizing a mixture containing the above-described monomer components by a usual emulsion polymerization method. Examples of the emulsifier used in emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate, and nonionic emulsifiers such as polyoxyethylene alkyl ether. These emulsifiers can be used alone or in combination of two or more. Examples of the polymerization initiator include a redox polymerization catalyst using an organic hydroperoxide, a redox polymerization catalyst in which a persulfate or a reducing agent such as sulfite or bisulfite is combined with this. The pressure-sensitive adhesive of the present invention contains known surfactants, fatty acid soaps, colorants, fillers, crosslinking agents, thickeners, antifoaming agents, leveling agents, etc. for the purpose of improving the performance and adjusting the properties. It can be added as appropriate.

≪Physical properties of adhesives≫
(Disaggregation)
The disaggregation property of the pressure-sensitive adhesive according to the present invention is preferably less than 50 mg, and more preferably less than 25 mg. In addition, the measuring method of disaggregation is described in the Example.
(Vs. SUS adhesive strength)
The pressure-sensitive adhesive strength of the pressure-sensitive adhesive according to the present invention is preferably 5.0 to 10.0 N / 15 mm, more preferably 5.5 to 9.5 N / 15 mm, and even more preferably 6. It is 0-9.0N / 15mm. In addition, the measuring method of SUS adhesive force is described in the Example.
(Probe tack)
The probe tack of the pressure-sensitive adhesive according to the present invention is preferably 6.0 to 12.0 N / 5 mmΦ, more preferably 6.5 to 11.5 N / 5 mmΦ, and even more preferably 7.0 to 7.0. 11.0 N / 5 mmΦ. In addition, the measuring method of probe tack is described in the Example.
(Ball tack)
The ball tack of the pressure-sensitive adhesive according to the present invention is preferably 18 to 32, more preferably 23 to 32, and further preferably 28 to 32. In addition, the measuring method of a ball tack is what was described in the Example.
(Resistance to glass plate)
The holding power (15 × 20 mm 1 kg 1 hr) of the pressure-sensitive adhesive according to the present invention is preferably 0.10 to 0.50 mm, more preferably 0,10 to 0.40 mm, and further preferably. Is 0.10 to 0.30 mm. In addition, the measuring method of glass plate retention strength is described in the Example.

≪Use of adhesives≫
The pressure-sensitive adhesive according to the present invention can be preferably used for a double-sided tape or sheet used for sealing an envelope or adhering a poster to a wall. Here, the base material is not particularly limited, and paper, synthetic paper, woven fabric, non-woven fabric, plastic film, metal foil, and the like can be used as appropriate. Among these, paper is preferable.

≪Method for manufacturing double-sided tape or sheet≫
It does not specifically limit as a manufacturing method of a double-sided tape (double-sided sheet), What is necessary is just to apply an adhesive on a base material using a well-known method. For example, a pressure-sensitive adhesive is applied and dried on release paper to form a pressure-sensitive adhesive layer, and this is transferred onto a substrate, or a pressure-sensitive adhesive is directly applied to the substrate and dried to form a pressure-sensitive adhesive layer. And the like.

≪Manufacturing method≫
A total of 100 parts by mass of the monomers and types shown in Table 1-1 to Table 2-2 are mixed and stirred with 3.0 parts by mass of an emulsifier and 50 parts by mass of distilled water to obtain 153.0 parts by mass of an emulsion. It was. In a reaction kettle equipped with a nitrogen introduction tube, 15 parts by mass of this emulsion and 50 parts by mass of distilled water were added, and the temperature was raised to 66 ° C. Further, 0.3 parts by weight of an initiator was added and the initial reaction was performed for 10 minutes, and then the remaining 138 parts by weight of the emulsion was added dropwise to the reaction kettle over 2.5 hours to perform polymerization. Further, an aging reaction was carried out for 3 hours to obtain a copolymer-containing pressure-sensitive adhesive composition. And in the prescription shown in the same table, the copolymer-containing pressure-sensitive adhesive composition obtained by emulsion polymerization and the emulsion resin were blended, and Examples 1 to 11 , Reference Examples 1 to 2 and Comparative Examples 1 to 13 were blended. The adhesive which concerns on was obtained. And these adhesive compositions were coated on both sides of a base material (manila paper manufactured with Manila hemp fibers, basis weight 14 g / m ² ) so that the thickness of the adhesive on one side after drying was 35 μm. The double-sided tape which has the adhesive of an Example , a reference example, and a comparative example was obtained. The results are also shown in the same table.

≪Evaluation method≫
(Polymerization stability)
The obtained emulsion was filtered with an 800 mesh filter cloth to confirm the presence or absence of aggregates. The case where the aggregate after drying was 5% or more was designated as C, the case of 1% or more to less than 5% was designated as B, and the case of less than 1% was designated as A.
(Disaggregation)
According to the “Provisional Industry Standards and Operation of Recyclable Stickers (All Separable Adhesive Papers)” established on October 17, 2018 by the Printing Adhesive Paper Manufacturers Association, the amount of residue in this test method If it is less than 50 mg, it can be regarded as a “recyclable sticker (adhesive paper that can be completely separated)”. Therefore, if the amount of the residue is less than 50 mg, A, and if it is 50 mg or more, C.
(Vs. SUS adhesive strength)
180 degree peeling adhesive strength to SUS304 steel plate was measured by the method described in JIS Z0237. Under the conditions of 23 ° C. and 50% RH, the tapes of Examples , Reference Examples and Comparative Examples (width: 15 mm) were used as test pieces, and the test pieces were attached to the surface of a mirror-finished SUS304 steel plate according to JIS Z0237. After pressure bonding with a 1 kg roller, the test piece was peeled off at 300 mm / min in the direction of 180 ° with respect to the test plate within 20 minutes to 40 minutes, and the peel force (N / 15 mm) obtained at that time was measured. .
(Probe tack)
It was measured by the method described in ASTM D2979. Under the conditions of 23 ° C. and 50% RH, the tapes of Examples , Reference Examples and Comparative Examples (width: 15 mm) were used as test pieces, and the test pieces were attached to the weight ring so as not to sag in accordance with ASTM D2979. A 5 mm cylindrical probe was brought into contact with an adhesive surface of a test piece with a load of 0.98 ± 0.001 N / cm ^{2 at} a contact speed of 10 ± 0.1 mm / sec for 1.0 ± 0.01 sec, and then contacted. The force (N / 5 mmφ) required to peel the probe from the adhesive surface in the vertical direction at the same speed as the speed was measured.
(Ball tack)
According to the method described in JIS Z0237, J.P. This was done by the DOW method.
(Resistance to glass plate)
It measured by the method of JISZ-0237. The measurement of the holding power against the glass plate is in accordance with JIS Z-0237, a sample having a width of 15 mm is attached to a glass plate in an atmosphere of 23 ° C. and 50% RH so as to have an area of 15 mm × 20 mm, and 300 mm / min with a 2 kg rubber roll. One reciprocating pressure was applied at a speed of After leaving for 20 minutes, the pressure-sensitive adhesive sheet was hung so as to hang vertically, a load of 1000 g was applied, and the shift length after 60 minutes was measured.
(Poster posting test)
A commercially available wallpaper (Asahi Pen Co., Ltd. repair paper HK-25) was attached to four corners of an A2 size poster (about 60 g) using a double-sided tape of 15 × 15 mm size. A month at 23 ° C. and 50% environment, if the falling sample is less than 25%, A, B if 25% or more and less than 50%, C if more than 50%.

Claims (8)

A pressure-sensitive adhesive composition containing a copolymer having a theoretical glass transition temperature of −20 ° C. or lower, obtained by emulsion polymerization of the following components (a), (b), (c) and (d); An adhesive formed by blending an emulsion resin containing at least an emulsion resin at a temperature of ° C or higher.
(A) at least one (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms other than the (meth) acryloyl group, based on the total mass of the components (a) to (d), 65. 5-85.5% by mass
(B) at least one (meth) acrylic acid alkoxyalkyl ester having 2 to 30 carbon atoms other than the (meth) acryloyl group, and / or 3 to 3 carbon atoms other than the (meth) acryloyl group; 50 a (meth) alkoxy acrylate (poly) alkylene glycol ester le, based on the total weight of components (a) ~ (d), 3 to 8 wt%
(C) at least one (meth) acrylic acid and / or a carboxyl group-containing (meth) acrylic acid ester having 1 to 4 carbon atoms other than the (meth) acryloyl group, 3.5 to 6.5% by mass based on the total mass of a) to (d)
(D) 8-20% by weight of at least one vinyl ester monomer, based on the total weight of components (a)-(d)   The pressure-sensitive adhesive according to claim 1, wherein the monomer according to component (a) has a polymer Tg of -30 ° C or lower obtained by polymerizing the monomer.   The pressure-sensitive adhesive according to claim 1 or 2, wherein the monomer according to component (b) has a polymer Tg of 0 ° C or lower obtained by polymerizing the monomer.   The pressure-sensitive adhesive according to any one of claims 1 to 3, wherein the monomer according to component (d) has a Tg of -40 ° C or higher obtained by polymerizing the monomer.   The component (a) is 68 to 82.5% by mass based on the total mass of the components (a) to (d), and the component (b) is the total mass of the components (a) to (d). The component (c) is 4 to 6.5% by mass based on the total mass of the components (a) to (d), and the component (c) is 3.5 to 7.5% by mass. The adhesive as described in any one of Claims 1-4 whose (d) is 10-18 mass% on the basis of the total mass of component (a)-(d).   The component (a) is 70 to 79.5% by mass based on the total mass of the components (a) to (d), and the component (b) is the total mass of the components (a) to (d). 4-7% by mass, the component (c) is 4.5-6% by mass based on the total mass of the components (a)-(d), and the component (d) is The pressure-sensitive adhesive according to any one of claims 1 to 5, which is 12 to 16% by mass based on the total mass of the components (a) to (d).   The pressure-sensitive adhesive according to any one of claims 1 to 6, wherein 3 to 30 parts by mass of the emulsion resin is blended with respect to 100 parts by mass of the pressure-sensitive adhesive composition.   The double-sided adhesive tape or sheet which has a base material and the adhesive as described in any one of Claims 1-7 applied to both surfaces of the said base material.