KR20160113159A - Acrylic pressure-sensitive-adhesive composition and pressure-sensitive-adhesive tape - Google Patents

Abstract

The present invention provides an acrylic pressure-sensitive adhesive composition capable of obtaining an adhesive tape excellent in fixing property. (A) an ABA type triblock copolymer (a) comprising a segment A mainly composed of a methacrylic ester and a segment B mainly composed of an acrylate ester, and a segment A composed mainly of a methacrylic ester and an acrylic ester (B) having a softening point of 110 ° C or more, which is compatible with the triblock copolymer (a) and the triblock copolymer (b), and the triblock copolymer (A) and the triblock copolymer (b) in the total amount of the triblock copolymer (a) and the triblock copolymer (b) as the constituent monomers of the segment B of the triblock copolymer (b) Wherein the compounding ratio of the triblock copolymer (b) to the pressure-sensitive adhesive composition is from 0.1% by mass to 50% by mass.

Description

TECHNICAL FIELD [0001] The present invention relates to an acrylic pressure-sensitive adhesive composition and a pressure-

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pressure-sensitive adhesive composition, and more particularly, to an adhesive tape comprising an acrylic pressure-sensitive adhesive composition and a pressure-sensitive adhesive composition applied to the substrate.

(Meth) acrylate monomer is excellent in weatherability, transparency, heat resistance, solvent resistance and the like, and has an advantage that the adhesive force can be easily controlled by changing the composition of the monomer to be constituted (See, for example, Patent Documents 1 to 3).

Japanese Patent Application Laid-Open No. 2005-307063 Japanese Patent Application Laid-Open No. 2009-102467 Japanese Patent Application Laid-Open No. 2006-206624

Typical practical properties required for an adhesive tape generally include three basic characteristics of adhesion (peeling strength), tack (tackiness) and holding force (cohesive force), but depending on the application of the adhesive tape, In addition to the basic characteristics, there is a case where characteristics such as stability are required. As an example of such fixation, there is an example of a stress or a stress caused by relaxation or warping of adherend, which occurs when adhering materials (for example, paper such as a poster) are adhered to a predetermined adhering surface (Hereinafter referred to as " shear fixation ") or an attachment (e.g., paper such as a thick paper) that can withstand a vertical shear force due to gravity (Hereinafter referred to as " rebound resisting property ") that can withstand the repulsive force to be restored to the original shape (which is not peeled off from each other) . That is, the fixability referred to herein is not a property of the self-adhesive but is a property of the adhesive itself which can withstand a predetermined external force such as stress, gravity and repulsive force as described above (even when a predetermined external force is applied, Which can be maintained.

In the acrylic pressure-sensitive adhesive composition described in the above Patent Documents 1 to 3, although the basic characteristics required as the above-mentioned pressure-sensitive adhesive tapes are at a practical level, the pressure-sensitive adhesive compositions of the above- Repellency). However, there is a problem in that the acrylic pressure-sensitive adhesive composition proposed so far can not obtain an adhesive tape excellent in fixing property.

The present invention has been made in view of the above problems, and an object thereof is to provide an acrylic pressure-sensitive adhesive composition capable of obtaining an adhesive tape excellent in fixing property.

DISCLOSURE OF THE INVENTION The present inventors have conducted intensive studies in order to solve the above problems. As a result, they have found that an acrylic ABA type triblock copolymer is used as a base polymer, and at least a part of the triblock copolymer is mixed with an acrylic acid- Ethylhexyl is used as a base polymer and a pressure sensitive adhesive composition containing a polymer blend containing a predetermined tackifier resin in the base polymer is used to obtain an adhesive tape excellent in fixing property, The present invention has been completed.

That is, the present invention relates to an ABA type triblock copolymer (a) comprising a segment A mainly composed of methacrylic acid ester and a segment B mainly composed of acrylate ester,

(B) an ABA-type triblock copolymer (b) comprising a segment A mainly composed of a methacrylic acid ester and a segment B mainly composed of an acrylate ester, and the triblock copolymer (a) and the triblock copolymer (C) having a softening point of 110 ° C or higher and compatibility with the triblock copolymer (b), wherein the constituent monomer of the segment B of the triblock copolymer (b) has 2-ethylhexyl acrylate, Wherein the compounding ratio of the triblock copolymer (b) to the total amount of the ternary copolymer (a) and the triblock copolymer (b) is 0.1% by mass or more and 50% by mass or less.

In the pressure-sensitive adhesive composition, it is preferable that the weight average molecular weight of the triblock polymer (a) is 60,000 or more and 400,000 or less.

The content of the tackifier resin (c) in the pressure-sensitive adhesive composition is preferably 15 parts by mass or more and 40 parts by mass or less, and more preferably 40 parts by mass or less, Or less.

In the above pressure-sensitive adhesive composition, it is preferable that the constituent monomers of the segment B of the triblock copolymer (b) are n-butyl acrylate and 2-ethylhexyl acrylate.

In this case, a blend ratio of BA: 2EHA = 75: 1 was obtained in a mass ratio of n-butyl acrylate (BA) to 2-ethylhexyl acrylate (2EHA) in segment B of the triblock copolymer (b) 25 to 5:95.

The pressure-sensitive adhesive composition may further contain a softening agent (d) compatible with the triblock copolymer (a) and the triblock copolymer (b).

In this case, it is preferable that the softening agent (d) is one kind selected from the group consisting of a diblock copolymer of AB type, an acrylic oligomer and a liquid rubber having segments same as the segment A and the segment B of the triblock copolymer (a) Or two or more compounds.

It is also preferable that the tackifier resin (c) is a rosin-based resin.

Further, the present invention is a pressure-sensitive adhesive tape comprising the above-described pressure-sensitive adhesive composition applied to at least one surface of a substrate.

According to the present invention, by using an acrylic triblock copolymer having a predetermined structure as a base polymer and using a pressure-sensitive adhesive composition containing a polymer blend containing a predetermined tackifier resin in the base polymer, An excellent adhesive tape can be obtained.

Hereinafter, a preferred embodiment of the present invention will be described in detail.

The pressure-sensitive adhesive composition according to the present invention will be described in the following order.

1 Composition of pressure-sensitive adhesive composition

  1-1 triblock copolymer (a)

  1-2 triblock copolymer (b)

  1-3 Adhesive resin (c)

  1-4 optional ingredients

2 Form of pressure-sensitive adhesive composition

3 Use of pressure-sensitive adhesive composition

&Quot; Composition of pressure-sensitive adhesive composition &

The pressure-sensitive adhesive composition according to the present invention is a composition containing two kinds of ABA type triblock copolymers (a) and (b) as a base polymer and further containing at least a tackifier resin (c) Tack, and holding force, the above-mentioned fixability is excellent. Hereinafter, each component in the pressure-sensitive adhesive composition according to the present invention will be described in order.

≪ Triblock copolymer (a) >

The triblock copolymer (a) is an ABA type triblock copolymer containing segment A mainly composed of methacrylic acid ester and segment B mainly composed of acrylic ester. Herein, the term " segment " in the present invention means a structural unit constituting each block in the triblock copolymer and includes, for example, a structural unit (polymer or oligomer) A containing monomer a and monomer b In the case of an ABA type triblock copolymer in which a structural unit (polymer or oligomer) B constituting the structural units A and B and a structural unit (polymer or oligomer) A containing the monomer a are bonded in this order, (The same applies to the triblock copolymer (b) to be described later).

(Segment A)

The segment A of the triblock copolymer (a) is not particularly limited as long as the methacrylate ester is mainly composed of the constituent monomers. Examples of such methacrylic acid esters include methyl methacrylate, ethyl methacrylate, Butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, 1-methylcyclohexyl methacrylate, methacrylic acid 2-methylcyclohexyl methacrylate, 4-methylcyclohexyl methacrylate, 2-phenoxyethyl methacrylate, 2-methoxyethyl methacrylate, 2- (N , N-dimethylamino) ethyl, methacrylic acid trifluoromethyl, n-pentyl methacrylate, n-hexyl methacrylate, 2-ethylhexyl methacrylate, undecyl methacrylate, tridecyl methacrylate Stearyl acrylate, 2-methoxypentyl methacrylate, 2- ( N, N-dimethylamino) pentyl, perfluoropentyl methacrylate, 2-trimethoxysilylpentyl methacrylate, and the like.

Among the above monomers, in order to improve the sticking properties (in particular, the holding power at high temperatures) of the adhesion promoter, the main constituent monomers of the segment A include methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, It is preferable to use monomers such as esters of methacrylic acid and an alcohol having 3 or less carbon atoms, such as isopropyl propyl acrylate and isopropyl acrylate.

Here, in order to be able to be referred to as "subject" in the present invention, it is preferable that the monomer is contained in an amount of 50% or more, more preferably 80% or more, more preferably 90% .

Examples of the monomers usable as the constituent monomers of the segment A of the triblock copolymer (a) other than the above methacrylic acid esters include methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, Methacrylamides such as N-isopropyl methacrylamide, N, N-dimethyl methacrylamide and N, N-diethyl methacrylamide, acrylamide, N-methylacrylamide, N-ethyl acrylamide, N Acrylamides such as isopropyl acrylamide, N, N-dimethylacrylamide and N, N-diethylacrylamide, and carboxyl groups such as methacrylic acid, acrylic acid, crotonic acid, maleic acid, maleic anhydride, , Aromatic vinyl monomers such as styrene,? -Methyl styrene and p-methyl styrene, conjugated diene monomers such as butadiene and isoprene, olefins such as ethylene and propylene,? -Caprolactone, It may be a lactone such as lactone.

(Segment B)

Subsequently, the segment B of the triblock copolymer (a) is not particularly limited as long as the acrylic ester is mainly composed of constituent monomers. Examples of such acrylic esters include methyl acrylate, ethyl acrylate, n-propyl acrylate, Butyl acrylate, n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, tridecyl acrylate, stearyl acrylate, cyclohexyl acrylate, acrylic acid Isobornyl, 2-methoxyethyl acrylate, 2- (N, N-dimethylamino) ethyl acrylate, trifluoromethyl acrylate, trimethoxysilylpropyl acrylate, lauryl acrylate, 2-methylbutyl acrylate, 4- Methyl-2-pentyl, n-octyl acrylate, isooctyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxypropyl acrylate.

Examples of monomers usable as the constituent monomers of the segment B of the triblock copolymer (a) other than the above-mentioned acrylic acid esters include alkyl methacrylates (e.g., methyl methacrylate, ethyl methacrylate, Methacrylic acid esters such as isopropyl methacrylate, sec-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, cyclohexyl methacrylate, and other constituent monomers of segment A described above) Methacrylamides such as methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, N-isopropylmethacrylamide, N, N-dimethylmethacrylamide and N, Acrylamides such as acrylamide, N-methylacrylamide, N-ethyl acrylamide, N-isopropyl acrylamide, N, N-dimethylacrylamide and N, N-diethylacrylamide, Acrylic acid, croton , Vinyl monomers having a carboxyl group such as maleic acid, maleic anhydride and fumaric acid, aromatic vinyl monomers such as styrene, o-methyl styrene and p-methyl styrene, conjugated diene monomers such as butadiene and isoprene, , Olefins such as propylene, and lactones such as? -Caprolactone and valerolactone.

(Weight average molecular weight)

The pressure-sensitive adhesive composition according to the present invention has excellent fixability, and the fixability is affected by the weight average molecular weight of the triblock copolymer (a). Specifically, the weight average molecular weight of the triblock copolymer (a) is preferably 60,000 or more and 400,000 or less. When the weight average molecular weight of the triblock copolymer (a) is less than 60,000, general properties such as adhesion, cohesion, and tack of the pressure-sensitive adhesive composition deteriorate and fixability also deteriorates. In order to further improve the above characteristics, the weight average molecular weight of the triblock copolymer (a) is more preferably 110,000 or more, more preferably 130,000 or more, and particularly preferably 150,000 or more. On the other hand, the triblock copolymer (a) preferably has a weight average molecular weight of 400,000 or less in view of the need to have a fluidity suitable for melt molding. In order to further improve the above effect, it is more preferable that the triblock copolymer (a) has a weight average molecular weight of 300,000 or less.

In addition, as the weight average molecular weight in the present invention, a value obtained from the polystyrene reduced molecular weight measured by gel permeation chromatography (GPC) is used.

(Hard segment content)

The content of the hard segment in the triblock copolymer (a) is preferably from 5 to 30 mass%, more preferably from 5 to 25 mass%, based on the total mass of the triblock copolymer (a) Particularly preferably 10 to 20% by mass.

(How to obtain)

As the triblock copolymer (a) according to the present invention, a raw material monomer may be synthesized by polymerization or a commercially available triblock copolymer (a) may be used. The polymerization method is not particularly limited, and for example, anionic polymerization, atom transfer radical polymerization (ATRP), or the like can be used. A detailed description of each polymerization method is omitted here, and examples of the anionic polymerization method include a method of performing anionic polymerization in the presence of an inorganic acid salt such as an alkali metal or an alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator, A known method such as a method in which a compound is used as a polymerization initiator and anion polymerization is carried out in the presence of an organoaluminum compound or a method in which an organic rare earth metal complex is used as a polymerization initiator and anion polymerization is carried out. Examples of the ATRP include organic halides A known method such as a method in which a halogenated sulfonyl compound is used as an initiator and polymerization is carried out in the presence of a transition metal compound or a nitrogen containing compound can be used. Commercially available products include, for example, "Clarity (registered trademark) series" of Kuraray Co., Ltd. and the like.

≪ Triblock copolymer (b) >

Like the triblock copolymer (a), the triblock copolymer (b) is a triblock copolymer of the ABA type including a segment A mainly composed of methacrylic acid ester and a segment B mainly composed of acrylic ester. However, the triblock copolymer (b) has a structure different from that of the triblock copolymer (a) in that it has 2-ethylhexyl acrylate as a constituent monomer of the segment B.

The pressure-sensitive adhesive composition according to the present invention is not limited to the above-mentioned triblock copolymer (a) but may further include, as a constituent monomer of the segment B of the ABA type triblock, a 2-ethylhexyl acrylate having a lower Tg than n-butyl acrylate (B), it is possible to remarkably improve the fixability in addition to the properties generally required as a pressure-sensitive adhesive such as an adhesive force, a tack, and a holding force. Particularly, as an effect of blending the triblock copolymer (b), it is possible to obtain a triblock copolymer (b) having an original shape which is generated when an adhered material (for example, paper such as thick paper) is fixed in a predetermined shape, It is possible to remarkably improve the property (rebound resilience) that can withstand the repulsive force to return (the attachment does not peel off). Hereinafter, the triblock copolymer (b) will be described in detail.

(Segment A)

The segment A of the triblock copolymer (b) is the same as the segment A of the above-mentioned triblock copolymer (a), and thus the detailed description thereof is omitted here. In the pressure-sensitive adhesive composition according to the present invention, the segment A of the triblock copolymer (a) and the segment A of the triblock copolymer (b) may be the same or different, but the triblock copolymer (a ) And the triblock copolymer (b), the segment A of the two is preferably the same.

(Segment B)

As described above, the segment B of the triblock copolymer (b) may have "other constituent monomers" as essential constituent monomers having 2-ethylhexyl acrylate. As the " other constituent monomer " in this case, those usable as the constituent monomers of the segment B of the triblock copolymer (a) can be used. Among them, from the viewpoint of compatibility with the triblock copolymer (a), it is preferable to use n-butyl acrylate as the "other constituent monomer". That is, it is preferable that the constituent monomers of the segment B of the triblock copolymer (b) are n-butyl acrylate and 2-ethylhexyl acrylate.

Further, n-butyl acrylate may be used as a constituent monomer of the segment B. (BA) and 2-ethylhexyl acrylate (2EHA) in the segment B of the triblock copolymer (b) are such that the mass ratio of BA: 2EHA = 95: 5 to 0: 100 Is suitable. When the compounding ratio is within this range, the effect of improving fixability of the pressure-sensitive adhesive composition is enhanced. In order to further improve the fixability, it is preferable that the compounding ratio of 2EHA is higher, more specifically, BA: 2EHA = 75:25 to 5:95, more preferably 60:40 to 5:95 Do.

In the pressure-sensitive adhesive composition according to the present invention, the constituent monomers of the "other constituent monomers" in the segment B of the triblock copolymer (b) and the segment B of the triblock copolymer (a) However, in consideration of the compatibility of the triblock copolymer (a) and the triblock copolymer (b), the constituent monomers of both are preferably the same.

(Weight average molecular weight)

The weight average molecular weight of the triblock copolymer (b) in the pressure-sensitive adhesive composition according to the present invention is preferably 30,000 or more and 200,000 or less, more preferably 150,000 or less, from the standpoint of practical and stable production. If the weight average molecular weight is less than 30,000, the adhesive strength is too low to cause practical problems. If the weight average molecular weight is more than 20,000, the viscosity is too high.

In addition, as the weight average molecular weight in the present invention, a value obtained from the polystyrene reduced molecular weight measured by gel permeation chromatography (GPC) is used.

(Hard segment content)

The content of the hard segment in the triblock copolymer (b) is preferably from 10 to 40 mass%, more preferably from 15 to 30 mass%, based on the total mass of the triblock copolymer (b) And particularly preferably 20 to 25% by mass.

(Purchase method)

As the triblock copolymer (b) according to the present invention, a raw material monomer may be synthesized by polymerization, or a commercially available triblock copolymer (b) may be used. The polymerization method is not particularly limited, but specific examples of the polymerization method are the same as those of the triblock copolymer (a). Commercially available products include, for example, "Clarity (registered trademark) series" of Kuraray Co., Ltd. and the like.

(Blending ratio of the triblock copolymer (a) and the triblock copolymer (b)

In the pressure-sensitive adhesive composition according to the present invention, in order to effectively exhibit fixability, the blend ratio of the triblock copolymer (a) and the triblock copolymer (b) (the triblock copolymer (a) and the triblock copolymer (b) Of the triblock copolymer (b) to the total amount of the triblock copolymer (b)) should be 0.1% by mass or more. As a result, the effect of improving fixability of the pressure-sensitive adhesive composition becomes remarkably high. On the other hand, if the blend ratio of the triblock copolymer (b) is too high, the performance as a base polymer is deteriorated, so that general characteristics such as adhesion, tack and holding force are lowered and the fixability of the pressure-sensitive adhesive composition is lowered . Therefore, it is preferable that the compounding ratio of the triblock copolymer (a) is increased. Specifically, the compounding ratio of the triblock copolymer (b) needs to be 50% by mass or less. The lower limit of the amount of the triblock copolymer (b) is preferably 1% by mass or more, more preferably 3% by mass or more, and more preferably 5% by mass or more in order to further improve the fixability And more preferably 10% by mass or more. On the other hand, the upper limit of the amount of the triblock copolymer (b) is preferably 40% by mass or less, more preferably 30% by mass or less, in order to further improve the fixability and suppress the deterioration of general properties And particularly preferably 20% by mass or less.

≪ Adhesion-imparting resin (c) >

The pressure-sensitive adhesive composition according to the present invention further contains, as an essential component, a tackifier resin (c) in addition to the base polymer described above. Although the above-mentioned triblock copolymer (a) and triblock copolymer (b) alone can have a function as a general pressure-sensitive adhesive composition, they have low adhesion and are not practical. Therefore, the pressure-sensitive adhesive composition according to the present invention contains the tackifier resin (c) so as to increase the tackiness to a practically sufficient level and to satisfy the general characteristics as a tackifier such as adhesive force, tack and holding force.

(Compatibility with triblock copolymer)

Here, the tackifier resin (c) is preferably used in combination with the triblock copolymer (a) and the triblock copolymer (b) so as to form a polymer blend with the triblock copolymer (a) and the triblock copolymer (b) . The resin having such compatibility is not particularly limited, and for example, a rosin-based resin, a terpene-based resin, or the like can be used. Examples of the rosin-based resin include rosin ester, hydrogenated rosin ester, disproportionated rosin ester, polymerized rosin ester, gum rosin, tall oil rosin, maleated rosin and maleic acid-modified rosin. For example, those mainly composed of terpene phenol resin, hydrogenated terpene phenol resin, aromatic modified terpene resin, aromatic modified hydrogenated terpene resin hydrogenated terpene resin,? -Pinene,? -Pinene, limonene and the like. Among them, from the viewpoint of improving the fixability, it is preferable to use a rosin-based resin as the tackifier resin according to the present invention.

(Softening point)

As the tackifier resin (c) according to the present invention, at least one tackifier resin having a softening point of 100 ° C or more is used. By compounding the tackifier resin (c) having such a high softening point, the fixability can be remarkably improved in addition to the properties generally required as a tackifier such as an adhesive force, a tack, and a holding force. Particularly, when a tackifier resin (c) having a high softening point (100 ° C or more) is blended to cause adhesion (for example, paper such as a poster) to adhere to a predetermined attachment surface (Shear fixation property) that can withstand the vertical direction shear force due to stress or gravity due to the relaxation or warping of the attachment (the attachment is not peeled off the attachment surface) can be remarkably improved. From the viewpoint of further improving this property, the softening point of the tackifier resin (c) is preferably 110 ° C or higher, more preferably 120 ° C or higher.

On the other hand, if the softening point of the tackifier resin (c) is too high, the resin becomes too hard and an appropriate viscosity as a tackifier can not be obtained. Therefore, the softening point of the tackifier resin (c) is preferably 200 占 폚 or lower, more preferably 170 占 폚 or lower, even more preferably 165 占 폚 or lower, and most preferably 160 占 폚 or lower. The above tackifier resin having a suitable softening point is preferably a main component (50 mass% or more based on the total mass of the total tackifier resin).

(Amount)

The blending amount of the tackifier resin (c) is preferably 15 parts by mass or more and 40 parts by mass or less when the total amount of the triblock copolymer (a) and the triblock copolymer (b) is 100 parts by mass. When the blending amount of the tackifier resin (c) is less than 15 parts by mass, there is a fear that the effect of the addition thereof (the effect of improving the adhesive strength and fixability) becomes insufficient. From the viewpoint of remarkably improving the adhesive strength and fixability of the pressure-sensitive adhesive composition, it is more preferable that the blending amount of the pressure-sensitive adhesive resin (c) is 25 parts by mass or more. On the other hand, when the blending amount of the tackifier resin (c) exceeds 40 parts by mass, the tack may be lowered.

<Optional Ingredients: Softener (d)>

The pressure-sensitive adhesive composition according to the present invention may further contain a softening agent (d) as an optional component in addition to the base polymer described above. Although the above-mentioned triblock copolymer (a) and triblock copolymer (b) alone can have the function as the pressure-sensitive adhesive composition according to the present invention, the tackbility is low and practically inadequate. Accordingly, the pressure-sensitive adhesive composition according to the present invention contains the softening agent (d) so that the pressure-sensitive adhesive force is increased to a practically sufficient level to satisfy general properties as a pressure-sensitive adhesive such as adhesive force, tack and holding force.

(Compatibility with triblock copolymer)

Herein, the softening agent (d) has compatibility with the triblock copolymer (a) and the triblock copolymer (b) so as to form a polymer blend with the triblock copolymer (a) and the triblock copolymer (b) . The compound having such compatibility is not particularly limited, and examples thereof include AB type diblock copolymers having segments same as segments A and B of the triblock copolymer (a), acrylic polymers, acrylic oligomers, (For example, polybutene, polyisobutylene, polyisoprene), process oil, phthalic acid esters, adipic acid esters, sebacic acid esters, aliphatic esters, and polyethers. These compounds may be used singly or in combination of two or more kinds. Among these compounds, it is preferable to use a diblock copolymer alone or a combination of a diblock copolymer and an acryl oligomer in view of good compatibility with the triblock copolymer (a) and the triblock copolymer (b) Particularly suitable.

The diblock copolymer is not particularly limited as long as it has the same segment as segment A and segment B of the above-mentioned triblock copolymer (a). Considering compatibility between the softener (d) and the triblock copolymer (a) and the triblock copolymer (b), the segments A and B of the diblock copolymer each contain a segment It is suitable to include the same constituent monomers as A and B. In this case, the constituent monomers of the segment A of the triblock copolymer (b) are the same as the segment A of the diblock copolymer and the triblock copolymer, and the constituent monomers of the segment B of the triblock copolymer (b) Monomer "is preferably the same as the segment B of the diblock copolymer and the triblock copolymer because the compatibility is the highest. The acrylic oligomer and the liquid rubber are preferable because they are highly compatible with the triblock copolymer (a) and the triblock copolymer (b).

(Amount)

From the viewpoint of improving the tackiness of the pressure-sensitive adhesive composition, the softening agent (d) may be blended. The blending amount of the softener (d) is preferably 250 parts by mass or less when the total amount of the triblock copolymer (a) and the triblock copolymer (b) is 100 parts by mass. If the blending amount of the softening agent (d) exceeds 250 parts by mass, there is a possibility that the holding force of the pressure-sensitive adhesive composition is lowered. Therefore, in order to improve the fixability, it is more preferably 200 parts by mass or less, and further preferably 150 parts by mass or less. The lower limit value is not particularly limited, and is, for example, 50 parts by mass.

<Optional ingredients: Other>

The pressure-sensitive adhesive composition according to the present invention may further contain additives such as fillers, antioxidants, heat stabilizers, ultraviolet absorbers, light stabilizers, antistatic agents, flame retardants, foaming agents, colorants, and dyes to the extent that the effects of the present invention are not impaired One or more of them may be added.

&Lt; Form of pressure-sensitive adhesive composition &

Although the composition of the pressure-sensitive adhesive composition according to the present invention has been described in detail in the foregoing, the pressure-sensitive adhesive composition of the present invention is not limited to the triblock copolymer (a), the triblock copolymer (b), the tackifier resin (c) And a pressure-sensitive adhesive composition in which an optional component (pressure-sensitive adhesive raw material) is dissolved in a predetermined solvent, or a hot-melt type pressure-sensitive adhesive composition obtained by melting and kneading the pressure-sensitive adhesive raw material. As the solvent used in the case of the solution type, for example, an organic solvent such as toluene or ethyl acetate may be used.

&Quot; Use of pressure-sensitive adhesive composition &

INDUSTRIAL APPLICABILITY The pressure-sensitive adhesive composition according to the present invention as described above can be used for applications such as an adhesive tape (one side or both sides). Hereinafter, as an example of the use of the pressure-sensitive adhesive composition according to the present invention, a double-sided pressure-sensitive adhesive tape formed by applying the pressure-sensitive adhesive composition described above to both sides of a substrate will be described. Also in the case of the single-sided pressure-sensitive adhesive tape, the pressure-sensitive adhesive is the same except that it is applied to one side of the substrate.

In the double-sided pressure-sensitive adhesive tape to which the pressure-sensitive adhesive composition according to the present invention is applied, the above-described pressure-sensitive adhesive composition is applied to both sides of the substrate, and a release paper is adhered to the surface of the pressure-

The base material is not particularly limited as long as it is in the form of a film or a sheet which can be applied to the pressure-sensitive adhesive composition. Examples of the base include rayon, cotton, acetate, polyethylene (PE (PE), stretched polypropylene (OPP), polyethylene terephthalate (PET), polytetrafluoroethylene, polyimide, polycarbonate (PC) A resin film such as polystyrene (PS), a resin foam such as polyurethane, PE, or butyl rubber, a metal foil such as aluminum or copper, or a rubber sheet such as natural rubber, SBR or butyl rubber.

The method of applying the pressure-sensitive adhesive composition onto the substrate is not particularly limited, but a method of dissolving the pressure-sensitive adhesive raw material in an organic solvent (coating method), a method of coating with a plurality of heating rolls (calendar method) (Hot melt method), or the like.

Example

EXAMPLES Next, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited by these examples.

<Description of raw materials>

The double-faced pressure-sensitive adhesive tapes of Examples 1 to 27 and Comparative Examples 1 to 7 were produced using the following raw materials.

[Triblock copolymer (a)]

Triblock copolymer (MMA), n-butyl acrylate (n-BA) copolymer (triblock copolymer, hard segment (segment A), soft segment (segment B) n-BA, hard segment content 16 mass%), molecular weight 140,000

Triblock copolymer, a hard segment (segment A) is MMA, a soft segment (segment B), and a triblock copolymer (a-2): methyl methacrylate (MMA) n-BA, hard segment content of 22 mass%), molecular weight of 115,000

Triblock copolymer, a hard segment (segment A) is MMA, a soft segment (segment B), and a triblock copolymer (a-3): methyl methacrylate (MMA) n-BA, hard segment content 23 mass%), molecular weight 75,000

Triblock copolymer, a hard segment (segment A) is MMA, a soft segment (segment B), and a triblock copolymer (a-4): methyl methacrylate (MMA) n-BA, a hard segment content of 12 mass%), a molecular weight of 180,000

[Triblock copolymer (b)]

Triblock copolymer (MMA, soft segment is n-BA and 2EHA) as a triblock copolymer (b-1): methyl methacrylate · n-butyl acrylate · 2-ethylhexyl acrylate n-BA: 2EHA = 50: 50 (mass ratio), hard segment content: 23 mass%) Molecular weight 100,000

Triblock copolymer, MMA hard segment, soft segment n-BA and 2EHA, respectively), and a triblock copolymer (b-2): methyl methacrylate · n-butyl acrylate · 2-ethylhexyl acrylate (2EHA) n-BA: 2EHA = 20: 80 (mass ratio), hard segment content: 23 mass%) Molecular weight 100,000

Triblock copolymer (MMA; soft segment: n-BA and 2EHA) as the triblock copolymer (b-3): methyl methacrylate · n-butyl acrylate · 2-ethylhexyl n-BA: 2EHA = 80: 20 (mass ratio), hard segment content: 23 mass%) Molecular weight 100,000

Triblock copolymer (MMA, soft segment: 2EHA, hard segment content: 23% by mass) Molecular weight 80,000 (tb &gt;

[Adhesion-imparting resin (c)]

PENCEL A: Rosin ester (softening point 100 캜)

PENCEL D-125: Polymerized rosin ester (softening point 125 캜)

PENCEL D-135: Polymerized rosin ester (softening point 135 캜)

PENCEL D-160: Polymerized rosin ester (softening point 160 캜)

YS Polystar G150: terpene phenol copolymer (softening point 150 캜)

[Softener (d)]

Clarity LA1114: methyl methacrylate-n-butyl acrylate copolymer (diblock copolymer, MMA hard segment, n-BA soft segment)

ARPON (registered trademark) UP-1000: non-functional type acrylic polymer

<Manufacturing Method>

A double-faced pressure-sensitive adhesive tape was prepared by a lyophilization method using the raw materials as shown in Table 1 (unit: parts by mass). Specifically, the raw materials were added to toluene in the amounts shown in Table 1 below and stirred to dissolve the raw materials, thereby preparing a solution type pressure-sensitive adhesive composition (solid content concentration: 50 mass%). Subsequently, the pressure-sensitive adhesive composition thus obtained was pasted to a release paper with an applicator. After drying in an oven at 100 캜 for 3 minutes, the nonwoven fabric (I) was bonded to the pressure-sensitive adhesive composition. Subsequently, the pressure-sensitive adhesive composition was pasted on the release paper in the same manner as described above, dried and then bonded to the nonwoven fabric side of (I) to prepare a double-sided pressure-sensitive adhesive tape. The application amount of the pressure-sensitive adhesive composition was 25 g / m &lt; 2 &gt; on both sides. Finally, in order to improve the anchoring of the pressure-sensitive adhesive and the nonwoven fabric, thermal lamination at 120 占 폚 was carried out to produce double-faced pressure-sensitive adhesive tapes of Examples 1 to 27 and Comparative Examples 1 to 7.

<Evaluation method>

The double-faced pressure-sensitive adhesive tapes of Examples 1 to 27 and Comparative Examples 1 to 7 prepared as described above were evaluated for their properties in the following manner.

(1) Basic properties (SUS adhesion, probe tack, ball tack, glass retention)

The basic characteristics were measured in accordance with JIS Z 0237. However, in the evaluation of the SUS adhesion, a method different from the method prescribed in JIS Z 0237 was used as a test plate and a pressing method. Specifically, in the evaluation of SUS adhesion, SUS304 steel sheet specified in JIS G 4305 was surface-polished and used as a test plate. At the time of pressing, 2000 g of rollers were reciprocated once at a speed of 300 mm / min, and after leaving for 20 to 40 minutes after the pressing, the adhesive force was measured (the others are the same as in JIS Z 0237).

(2) Shear fixation test

A 15 mm square double-sided adhesive tape was attached to the four corners of an A2 size, a 87 g / m2 basis weight, and a 125 占 퐉 thick Asukuru color coated paper (poster). Thereafter, the color coated paper was pressed firmly with a finger on the wall with Sanshitsu vinyl chloride wallpaper SP7204, and left for more than 12 hours under the environment of 40 DEG C and about 10% RH. At this time, after the attachment, the dropping time from the wall to the time when the poster fell down was measured and evaluated according to the following criteria.

A: Drop time is 4 days or more

B: Falling time is more than 24 hours and less than 4 days

C: Falling time is more than 5 hours and less than 24 hours

D: Drop time less than 5 hours

(3) Repulsive fixing test

A double-faced adhesive tape having a width of 15 mm was attached to the short side of an Imamura Shiko envelope (thick paper) having an A4 size and a basis weight of 500 g / m 2. A thick paper was rolled along a paper tube having a diameter of 78 mm to bond the short side of the other end To prepare a cylinder. At this time, the peeling time until the cylinder was spread (peeling of the bonded portion of the thick paper) after the attachment was measured, and evaluated according to the following criteria.

A: The peeling time is 6 days or more

B: Peeling time is 24 hours or more but less than 6 days

C: Peeling time is 5 hours or more and less than 24 hours

D: Peeling time less than 5 hours

&Lt; Evaluation result >

PMMA / Pn-BA / PMMA triblock copolymer, PMMA / Pn-BA-2EHA / PMMA is added to the paper to fix the paper in a cylindrical shape while maintaining the adhesive force, And the rebound resilience that can withstand the repulsive force of peeling can be remarkably improved. The SUS adhesive strength was 7.6 N / 15 mm, the probe tack was 9.3 N / 5 mm ?, the ball tack was No. 12, the glass holding force was 0.2 mm / · 1 kg · 1 h]. In the other Examples and Comparative Examples, almost the same results as in Example 1 were obtained.

Further, by adding a tackifier resin having a high softening point, it is found that in addition to the repulsion fixing property, the shearing fixation which can withstand the shearing force in the vertical direction due to stress and gravity, there was.

While the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. That is, it is understood that other forms or various modifications that a person skilled in the art can make within the scope of the invention described in the claims are also within the technical scope of the present invention.

Claims (8)

An ABA type triblock copolymer (a) comprising a segment A mainly composed of methacrylic acid ester and a segment B mainly composed of acrylate ester,
An ABA type triblock copolymer (b) comprising a segment A mainly composed of methacrylic acid ester and a segment B mainly composed of acrylic acid ester,
(C) having compatibility with the triblock copolymer (a) and the triblock copolymer (b) and having a softening point of 110 ° C or higher,
&Lt; / RTI &gt;
As the constituent monomers of the segment B of the triblock copolymer (b), it is preferable to use a monomer having 2-ethylhexyl acrylate,
Wherein the compounding ratio of the triblock copolymer (b) to the total amount of the triblock copolymer (a) and the triblock copolymer (b) is 0.1% by mass or more and 50% by mass or less. The pressure-sensitive adhesive composition according to claim 1, wherein the triblock polymer (a) has a weight average molecular weight of 60,000 or more and 400,000 or less. The thermoplastic resin composition according to any one of claims 1 to 3, wherein the blending amount of the tackifier resin (c) is 100 parts by mass as the total of the triblock copolymer (a) and the triblock copolymer (b) 15 parts by mass or more and 40 parts by mass or less. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the constituent monomers of the segment B of the triblock copolymer (b) are n-butyl acrylate and 2-ethylhexyl acrylate. 5. The polypropylene resin composition according to claim 4, wherein the compounding ratio of n-butyl acrylate (BA) to 2-ethylhexyl acrylate (2EHA) in segment B of the triblock copolymer (b) is BA: 2EHA = 75 : 25 to 5:95. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising a softening agent (d) compatible with the triblock copolymer (a) and the triblock copolymer (b). The method according to claim 6, wherein the softening agent (d) is selected from the group consisting of AB type diblock copolymers, acrylic oligomers and liquid rubbers having segments identical to segment A and segment B of the triblock copolymer (a) Wherein the pressure-sensitive adhesive composition is one or more compounds. A pressure-sensitive adhesive tape comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 7 applied on at least one side of a substrate.