JP6289319B2 - Hot melt adhesive composition - Google Patents

Description

  The present invention relates to an adhesive composition suitable for a hot melt adhesive.

A pressure-sensitive adhesive composition containing a styrenic block copolymer has been conventionally used for various applications in the form of pressure-sensitive adhesive articles such as pressure-sensitive adhesive tapes and pressure-sensitive adhesive tapes. However, when used for adherends with low polarity, such as adherends made of polyolefins such as polyethylene and polypropylene, their adhesive strength may be insufficient. Moreover, when it was set as the mixing | blending which raises adhesive force, when re-peeling an adhesive from a to-be-adhered body, what is called an adhesive residue generate | occur | produced and the to-be-adhered body might be contaminated.
As a means for solving the problem of the pressure-sensitive adhesive composition containing these styrenic block copolymers, a pressure-sensitive adhesive composition containing more acrylic block copolymers than styrenic block copolymers has been proposed (for example, Patent Document 1).
In addition, for the purpose of improving adhesion to olefin polymers, it is mainly used for composite molded products and molded products, but elastomers containing styrene block copolymers, acrylic block copolymers, and modified olefin polymers. A composition (for example, Patent Document 2), a composition containing an acrylic block copolymer and an olefin polymer (for example, Patent Document 3), and the like have been studied.
However, by any of the conventional methods, it has excellent adhesion to not only highly polar adherends but also adherends having low polarity such as adherends made of polyolefin such as polyethylene and polypropylene, and at the time of re-peeling Thus, it is difficult to reduce the contamination of the adherend.

JP 2012-102172 A WO2007 / 023932 JP 2005-54065 A Japanese Patent Laid-Open No. 06-93060 Japanese National Patent Publication No. 05-507737 JP-A-11-335432

Macromolecular Chemistry and Physics, 2000, 201, p. 1108 to 1114

  Thus, the object of the present invention is to express sufficient adhesive force to adherends having low polarity, such as adherends made of polyolefins such as polyethylene and polypropylene, which have been difficult to adhere conventionally. In addition, a hot-melt pressure-sensitive adhesive composition that expresses an appropriate adhesive force to other adherends such as glass, stainless steel, acrylic, and can be peeled smoothly without contaminating the adherend during peeling, And providing an adhesive tape and an adhesive film using the hot melt adhesive composition.

According to the invention, the object is
[1] At least one polymer block (P) comprising an aromatic vinyl compound unit and at least one conjugated diene compound unit in which at least a part of the carbon-carbon unsaturated double bond may be hydrogenated An aromatic vinyl-conjugated diene block copolymer (I) having a number average molecular weight of 20,000 to 500,000,
Hot containing an acrylic block copolymer (II) having at least one polymer block (A) composed of methacrylate units and at least one polymer block (B) composed of acrylate units A melt adhesive composition comprising:
A hot melt pressure-sensitive adhesive composition having a mass ratio of aromatic vinyl-conjugated diene block copolymer (I): acrylic block copolymer (II) of 99: 1 to 41:59;
[2] The hot melt pressure-sensitive adhesive composition according to [1], wherein the content of the polymer block (A) in the acrylic block copolymer (II) is 5 to 50% by mass;
[3] The acrylic block copolymer (II) is a diblock copolymer represented by the formula: (A)-(B), represented by the formula: (A)-(B)-(B ′). And a triblock copolymer represented by the formula: (A)-(B)-(A) [wherein (A) is a polymer block composed of methacrylate units. (A), (B) is a polymer block (B) comprising an acrylate ester unit, (B ′) is a polymer block (B) comprising an acrylate ester unit having a structure different from (B), − Indicates a bond of each polymer block. ] The hot-melt pressure-sensitive adhesive composition according to [1] or [2], which is at least one acrylic block copolymer selected from
[4] The acrylic ester unit constituting the polymer block (B)
Formula ^{_{CH 2 = CH-COOR 1 (}} 1)
(Wherein R ¹ represents an organic group having 1 to 5 carbon atoms) and an acrylic ester (b-1) represented by:
Formula ^{_{CH 2 = CH-COOR 2 (}} 2)
(Wherein R ² represents an organic group having 6 to 12 carbon atoms) and is a structural unit derived from an acrylate ester (b-2), and the acrylate ester (b-1) and The hot melt according to any one of [1] to [3], wherein a mass ratio [(b-1) / (b-2)] of the acrylic ester (b-2) is 70/30 to 0/100. An adhesive composition;
[5] The number average molecular weight of the polymer block (P) in the aromatic vinyl-conjugated diene block copolymer (I) is 2,500 to 100,000, and the number average molecular weight of the polymer block (Q) Is a hot melt pressure-sensitive adhesive composition according to any one of [1] to [4], which has a viscosity of 10,000 to 400,000;
[6] The hot melt pressure-sensitive adhesive according to any one of [1] to [5], wherein the aromatic vinyl compound constituting the polymer block (P) is at least one selected from styrene and α-methylstyrene. Composition;
[7] Any of [1] to [6], wherein the mass ratio of aromatic vinyl-conjugated diene block copolymer (I): acrylic block copolymer (II) is 90:10 to 51:49. A hot melt pressure-sensitive adhesive composition according to claim 1;
[8] The hot melt pressure-sensitive adhesive composition according to any one of [1] to [7], further comprising a tackifying resin;
[9] The tackifier resin is a polymer block (Q) of the aromatic vinyl-conjugated diene block copolymer (I) and a polymer block (B) of the acrylic block copolymer (II). The hot melt pressure-sensitive adhesive composition according to [8], which is compatible;
[10] The hot melt pressure-sensitive adhesive composition according to [8] or [9], wherein the tackifying resin is a rosin resin;
[11] A laminate having an adhesive layer comprising the hot melt adhesive composition according to any one of [1] to [10];
[12] An adhesive tape having an adhesive layer made of the hot melt adhesive composition according to any one of [1] to [10]; and [13] [1] to [10] An adhesive film having an adhesive layer made of an adhesive composition;
Is achieved by providing

  According to the present invention, sufficient adhesive strength is exhibited with respect to adherends having low polarity such as adherends made of polyolefins such as polyethylene and polypropylene, which have been difficult to adhere, and glass. , A hot-melt pressure-sensitive adhesive composition that exhibits an appropriate adhesive force to other adherends such as stainless steel and acrylic, and can be peeled off smoothly without contaminating the adherend, and the hot An adhesive tape and an adhesive film using the melt adhesive composition can be provided.

  Hereinafter, the present invention will be described in detail. In this specification, “(meth) acrylic acid ester” is a general term for “methacrylic acid ester” and “acrylic acid ester”, and “(meth) acrylic” means “methacrylic” and “acrylic”. It is a generic name.

[Aromatic vinyl-conjugated diene block copolymer (I)]
The aromatic vinyl-conjugated diene block copolymer (I) used in the present invention comprises at least one polymer block (P) comprising an aromatic vinyl compound unit and a conjugated diene compound unit, and is carbon-carbon unsaturated. And at least one polymer block (Q) in which at least a part of the double bond may be hydrogenated. The total number average molecular weight of the aromatic vinyl-conjugated diene block copolymer (I) is 20,000 to 500,000.

  Examples of the aromatic vinyl compound that is a constituent unit of the polymer block (P) include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2, 4 -Aromatic vinyl compounds having no functional group such as dimethylstyrene, tert-butylstyrene, 4- (1-adamantyl) styrene, divinylbenzene, 1,1-diphenylethylene, vinylnaphthalene, vinylanthracene; N, N- Examples thereof include aromatic vinyl compounds having a functional group such as diethyl-p-aminoethylstyrene and vinylpyridine.

  Among these, from the viewpoint of improving heat resistance and durability without impairing hot melt coating properties of the obtained hot melt pressure-sensitive adhesive composition, aromatic vinyl compounds having no functional group are preferable, and styrene and α- More preferred is methylstyrene. The polymer block (P) may be composed of one of these aromatic vinyl compounds or may be composed of two or more. In addition, the aromatic vinyl-conjugated diene block copolymer (I) preferably has two or more polymer blocks (P) from the viewpoint of enhancing durability. In that case, these polymer blocks (P) may be the same or different.

  The number average molecular weight (Mn) of the polymer block (P) is not particularly limited, but is preferably in the range of 2,500 to 100,000, and more preferably in the range of 3,000 to 50,000. When the number average molecular weight (Mn) of the polymer block (P) is smaller than this range, the resulting aromatic vinyl-conjugated diene block copolymer (I) may have insufficient cohesive strength. Further, when the number average molecular weight (Mn) of the polymer block (P) is larger than this range, the resulting aromatic vinyl-conjugated diene block copolymer (I) has a high melt viscosity, and hot melt adhesion The productivity when producing the agent composition may be inferior. In addition, the number average molecular weight (Mn) in this specification is the weight average molecular weight of standard polystyrene conversion calculated | required by the gel permeation chromatography (GPC) measurement. The proportion of the aromatic vinyl compound unit contained in the polymer block (P) is preferably 60% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more in the polymer block (P).

  The glass transition temperature (Tg) of the polymer block (P) is preferably 70 to 180 ° C, more preferably 80 to 150 ° C, and further preferably 90 to 120 ° C. When the glass transition temperature is in this range, the polymer block (P) acts as a physical pseudo-crosslinking point at the normal use temperature of the pressure-sensitive adhesive, and the cohesive force of the hot melt pressure-sensitive adhesive is expressed. Excellent adhesive properties, adhesive durability and heat resistance. The glass transition temperature is an extrapolation start temperature of a curve obtained by DSC measurement.

  Examples of the conjugated diene compound that is a constituent unit of the polymer block (Q) include butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 2-methyl-1,3-octadiene. 1,3-hexadiene, 1,3-cyclohexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, myrcene and chloroprene.

  Among these, isoprene, butadiene, or a mixture thereof is preferable from the viewpoint that the adhesive property of the obtained hot melt adhesive composition is enhanced. The polymer block (Q) may be composed of one of these conjugated diene compounds or may be composed of two or more. When the polymer block (Q) is composed of two or more kinds of conjugated dienes (for example, butadiene and isoprene), their bonding form is completely alternate, random, tapered, partially blocky, or those 2 It may be a combination of more than one species.

  The microstructure of the conjugated diene compound unit contained in the polymer block (Q) is not particularly limited. For example, when the conjugated diene compound unit is an isoprene unit, the 1,4-bond amount is 70 mol% or more. Desirably. When the conjugated diene compound unit is a butadiene unit, the 1,4-bond amount is desirably 40 to 80 mol%.

The ratio of the conjugated diene compound unit contained in the polymer block (Q) is preferably 60% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more in the polymer block (Q).
Moreover, it is also one preferable aspect that the polymer block (Q) contains an aromatic vinyl compound unit in addition to the conjugated diene compound unit. When the aromatic vinyl compound unit is contained in the polymer block (Q), the proportion of the aromatic vinyl compound unit in the polymer block (Q) is preferably 40% by mass or less, and more preferably 35% by mass or less. Preferably, 30 mass% or less is more preferable. In the case where an aromatic vinyl compound unit is included in addition to the conjugated diene compound unit, the bonding form thereof is not particularly limited, and for example, completely alternating, random, tapered, partially blocky, or two of them A combination of the above may be used.

  At least a part of the carbon-carbon unsaturated double bond contained in the conjugated diene compound unit in the polymer block (Q) may be hydrogenated. The method for hydrogenation is not particularly limited, and can be performed by producing a non-hydrogenated block copolymer and then hydrogenating it by a known method. For example, in the presence of a hydrogenation catalyst, hydrogen is reacted in a state where an unhydrogenated block copolymer is dissolved in an inert organic solvent such as n-hexane or cyclohexane that is inert to the reaction and the hydrogenation catalyst. Is preferably used. Examples of hydrogenation catalysts include Raney nickel; heterogeneous catalysts in which metals such as Pt, Pd, Ru, Rh, Ni are supported on carbon, alumina, diatomaceous earth, etc .; transition metal compounds, alkylaluminum compounds, alkyllithium compounds, etc. A Ziegler catalyst made of a combination is used. The reaction is usually carried out at a hydrogen pressure of 0.1 to 20 MPa, a reaction temperature of 20 ° C. to 250 ° C., and a reaction time of 0.1 to 100 hours. An unhydrogenated aromatic vinyl-conjugated diene block copolymer (I) in which the polymer block (Q) is not hydrogenated can also be preferably used in the present invention.

  The glass transition temperature (Tg) of the polymer block (Q) is preferably −100 to 30 ° C., more preferably −90 to 20 ° C., still more preferably −85 to 10 ° C., Most preferably, it is −80 to 0 ° C. When the glass transition temperature is in this range, it can have adhesiveness at room temperature when used as a hot melt adhesive.

  The polymer block (P) and the polymer block (Q) may contain mutual structural units as long as the effects of the present invention are not impaired. Moreover, you may contain another structural unit as needed. Examples of such other structural unit monomers include olefinic monomers such as ethylene, propylene, 1-butene, isobutene, pentene, hexene; (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride Vinyl monomers having a carboxyl group such as acid and fumaric acid; vinyl monomers having a functional group such as (meth) acrylamide, (meth) acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride; methyl methacrylate, Examples thereof include methacrylic acid esters such as ethyl methacrylate; acrylic acid esters such as methyl acrylate, n-butyl acrylate and 2-ethylhexyl acrylate; and lactone monomers such as ε-caprolactone and valerolactone. When these monomers are used, the amount is preferably 40% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less, based on the total mass of the monomers used for each polymer block. Used in.

  The aromatic vinyl-conjugated diene block copolymer (I) used in the present invention has other polymer blocks as necessary in addition to the polymer block (P) and the polymer block (Q). It may be. Examples of such other polymer blocks include methyl methacrylate, ethyl methacrylate, methyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, acrylonitrile, methacrylonitrile, ethylene, propylene, isobutene, octene, and acetic acid. Examples include a polymer block or copolymer block composed of monomers such as vinyl, maleic anhydride, vinyl chloride, vinylidene chloride; a polymer block composed of polyethylene terephthalate, polylactic acid, polyurethane, polydimethylsiloxane, and the like.

The aromatic vinyl-conjugated diene block copolymer (I) has a general formula: when the polymer block (P) is “(P)”; and the polymer block (Q) is “(Q)”.
[(P)-(Q)] n
[(P)-(Q)] n- (P)
(Q)-[(P)-(Q)] n
[(P)-(Q)] n-Z
[(Q)-(P)] n-Z
(In the formula, n is an integer of 1 to 30, Z is a coupling site (a coupling site after a coupling agent reacts with a polymer terminal to form a chemical bond,-represents a bond of each polymer block) In addition, when a plurality of polymer blocks (P) and polymer blocks (Q) are included in the formula, they may be polymer blocks having the same structure or different structures having different structures. It may be a combined block). Here, the “different structure” means the monomer unit constituting the polymer block, the molecular weight, the molecular weight distribution, the stereoregularity, and the ratio of each monomer unit and the form of copolymerization (random , Gradient, block) means a different structure. The value of n is preferably 1 to 15, more preferably 1 to 8, and further preferably 1 to 4. Among the above structures, [(P)-(Q)] n, [(P)-(Q)] n- (P), (Q)-[(P)-(Q)] n are represented. A linear block copolymer and a star-shaped block copolymer represented by [(P)-(Q)] nZ are preferred, and a diblock copolymer represented by (P)-(Q) A polymer, a triblock copolymer represented by (P)-(Q)-(P), and a star-shaped block copolymer represented by [(P)-(Q)] nZ, When it is set as a hot-melt adhesive composition, it is more preferable from a viewpoint which is excellent in adhesion durability. A mixture of at least two block copolymers among the diblock copolymer, triblock copolymer, and star-shaped block copolymer is also preferable from the viewpoint of excellent hot melt coating properties and adhesiveness.

  The total number average molecular weight (Mn) of the aromatic vinyl-conjugated diene block copolymer (I) used in the present invention is 20,000 to 500,000. Among them, from the viewpoint of productivity when the hot melt pressure-sensitive adhesive composition of the present invention is formed into a film by heating and melting, such as a hot melt coating method, a T-die method, an inflation method, a calender molding method, a lamination method, The Mn is preferably 30,000 to 400,000, more preferably 35,000 to 300,000, and more preferably 40,000 to 250,000 from the viewpoint of enabling hot melt coating at a higher speed. preferable.

  The ratio (Mw / Mn) of the overall weight average molecular weight (Mw) and number average molecular weight (Mn) of the aromatic vinyl-conjugated diene block copolymer (I) is 1.0 to 1.8. Is preferred. When it is set as a hot-melt adhesive composition, it is more preferable that it is 1.0-1.5 from the point which is excellent in adhesion durability, and it is further more preferable that it is 1.0-1.3.

The content of the polymer block (P) in the aromatic vinyl-conjugated diene block copolymer (I) is not particularly limited, but the adhesive strength and wettability of the resulting hot melt pressure-sensitive adhesive composition From such points, it is preferably in the range of 5 to 70% by mass, more preferably in the range of 8 to 50% by mass, and still more preferably in the range of 10 to 40% by mass. Moreover, content of the polymer block (Q) in the said block copolymer (I) exists in the range of 30-95 mass% from points, such as adhesive force and wettability of the hot-melt adhesive composition obtained. It is preferable that it is in the range of 50 to 92 mass%, more preferably in the range of 60 to 90 mass%. The contents of the polymer block (P) and the polymer block (Q) in the aromatic vinyl-conjugated diene block copolymer (I) can be determined from a ¹ H-NMR spectrum.

  The aromatic vinyl-conjugated diene block copolymer (I) may have a carboxyl group, a hydroxyl group, an acid anhydride group, an amino group in the molecular chain and / or at the molecular end as long as the gist of the present invention is not impaired. 1 type (s) or 2 or more types of functional groups, such as a group and an epoxy group, may be included.

  The method for producing the aromatic vinyl-conjugated diene block copolymer (I) is not particularly limited. For example, in an organic solvent inert to a polymerization reaction such as n-hexane or cyclohexane using an alkyl lithium compound as an initiator. Then, an aromatic vinyl compound and a conjugated diene can be sequentially anionically polymerized to form each polymer block, and a coupling reaction or the like can be performed as necessary.

  Moreover, you may use the product marketed as said aromatic vinyl-conjugated diene type block copolymer (I). Specific examples of the products include KRATON D1161, D1101, and G1651 (all manufactured by KRATON Polymers); JSR SIS5200, SIS5250, TR2827 (all manufactured by JSR), and the like.

[Acrylic block copolymer (II)]
The acrylic block copolymer (II) used in the present invention comprises at least one polymer block (A) composed of methacrylic ester units and at least one polymer block (B) composed of acrylate units. Have

  Examples of the methacrylic acid ester constituting the structural unit of the polymer block (A) include, for example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid. sec-butyl, tert-butyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, isobornyl methacrylate, methacrylic acid Methacrylic acid ester having no functional group such as phenyl and benzyl methacrylate; methoxyethyl methacrylate, ethoxyethyl methacrylate, diethylaminoethyl methacrylate, methacrylate Le 2-hydroxyethyl methacrylate, 2-aminoethyl methacrylate, glycidyl methacrylate, and methacrylic acid esters having a functional group such as tetrahydrofurfuryl methacrylate.

  Among these, from the viewpoint of improving the heat resistance and adhesion durability of the obtained hot-melt pressure-sensitive adhesive composition, a methacrylic acid ester having no functional group is preferable, such as methyl methacrylate, ethyl methacrylate, tert-butyl methacrylate. Cyclohexyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, phenyl methacrylate, and benzyl methacrylate are more preferable, and the phase separation between the polymer block (A) and the polymer block (B) becomes clearer, and the hot melt Methyl methacrylate is more preferable from the viewpoint of increasing the cohesive strength of the pressure-sensitive adhesive composition. The polymer block (A) may be composed of one of these methacrylic acid esters or may be composed of two or more. In addition, the acrylic block copolymer (II) preferably has two or more polymer blocks (A) from the viewpoint of improving adhesion durability. In that case, these polymer blocks (A) may be the same or different.

  The number average molecular weight (Mn) of the polymer block (A) is not particularly limited, but is preferably in the range of 1,000 to 50,000, and more preferably in the range of 2,000 to 30,000. When the number average molecular weight (Mn) of the polymer block (A) is smaller than this range, the resulting acrylic block copolymer (II) may have insufficient cohesive strength. Further, when the number average molecular weight (Mn) of the polymer block (A) is larger than this range, the resulting acrylic block copolymer (II) has a high melt viscosity, and a hot melt pressure-sensitive adhesive composition is produced. In some cases, the productivity is poor. The proportion of the methacrylic acid ester unit contained in the polymer block (A) is preferably 60% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more in the polymer block (A).

  The glass transition temperature (Tg) of the polymer block (A) is preferably 80 to 140 ° C, more preferably 90 to 130 ° C, and further preferably 100 to 120 ° C. When the glass transition temperature is within this range, the polymer block (A) acts as a physical pseudo-crosslinking point at the normal use temperature of the pressure-sensitive adhesive, and the cohesive force of the hot-melt pressure-sensitive adhesive is expressed. Excellent adhesive properties, adhesive durability, and heat resistance.

The acrylic ester that is a constituent unit of the polymer block (B) is represented by the general formula CH ₂ = CH-COOR ¹ (1) (in the formula (1), R ¹ represents an organic group having 1 to 5 carbon atoms). An acrylate ester (hereinafter referred to as an acrylate ester (b-1)), a general formula CH ₂ ═CH—COOR ² (2) (in the formula (2), R ² is an organic compound having 6 to 12 carbon atoms) Acrylic acid ester (hereinafter referred to as acrylic acid ester (b-2)) represented by a group and an acrylic acid ester other than these.

Examples of the organic group having 1 to 5 carbon atoms represented by R ¹ include an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, and an amyl group (pentyl group); a methoxyethyl group, Examples thereof include an alkyl group having a functional group such as ethoxyethyl group, hydroxyethyl group and aminoethyl group and having a total carbon number of 1 to 5; glycidyl group, tetrahydrofurfuryl group and the like. Examples of the acrylic ester (b-1) include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, and acrylic. Acrylic acid ester having no functional group such as tert-butyl acid, amyl acrylate, isoamyl acrylate; methoxyethyl acrylate, ethoxyethyl acrylate, 2-hydroxyethyl acrylate, 2-aminoethyl acrylate, acrylic acid Examples thereof include acrylic acid esters having a functional group such as glycidyl and tetrahydrofurfuryl acrylate.

Examples of the organic group having 6 to 12 carbon atoms represented by R ² include an alkyl group having 6 to 12 carbon atoms such as a hexyl group, an ethylhexyl group, an octyl group, a decyl group, an isobornyl group, a lauryl group, and a cyclohexyl group; And an alkyl group having a functional group such as an aromatic ring group having 6 to 12 carbon atoms such as a benzyl group, a diethylaminoester group, and a phenoxyethyl group, and having a total carbon number of 6 to 12. Examples of the acrylic ester (b-2) include n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, isobornyl acrylate, lauryl acrylate, and acrylic. Examples include acrylic acid esters having no functional group such as cyclohexyl acid, phenyl acrylate, and benzyl acrylate; acrylic acid esters having a functional group such as diethylaminoethyl acrylate and phenoxyethyl acrylate.

  Examples of the acrylic ester other than the acrylic ester (b-1) and the acrylic ester (b-2) include octadecyl acrylate.

  Among the acrylic acid esters (b-1), from the viewpoint of strengthening the initial tack of the pressure-sensitive adhesive comprising the obtained hot melt pressure-sensitive adhesive composition, an acrylic acid ester having no functional group is preferable, and ethyl acrylate, acrylic acid n-Butyl is more preferable, and n-butyl acrylate is particularly preferable.

Among the acrylic ester (b-2), the phase separation between the polymer block (A) and the polymer block (B) becomes clearer, so that a high cohesive force is exhibited when a hot melt pressure-sensitive adhesive composition is used. In view of the above, an acrylate ester having no functional group is preferable, and 2-ethylhexyl acrylate, n-octyl acrylate, isooctyl acrylate, and benzyl acrylate are more preferable. Moreover, 2-ethylhexyl acrylate is more preferable from the point that the obtained hot-melt pressure-sensitive adhesive composition exhibits stable adhesion durability in a wide temperature range.
The above acrylic esters may be used alone or in combination of two or more. Moreover, 60 mass% or more in a polymer block (B) is preferable, as for the ratio of the acrylic ester unit contained in a polymer block (B), 80 mass% or more is more preferable, and 90 mass% or more is further more preferable.

  The acrylic acid ester unit constituting the polymer block (B) is from the acrylic acid ester (b-1) and the acrylic acid ester (b-2) in terms of expressing appropriate tackiness that can be removed again at room temperature. It is preferably at least one selected.

When the acrylate unit constituting the polymer block (B) is a unit composed of at least one selected from the acrylate ester (b-1) and the acrylate ester (b-2), the mass ratio [ (B-1) :( b-2)] is preferably 70:30 to 0: 100, more preferably 60:40 to 0: 100, and 55:45 to 0: 100. More preferably. Within the above range, compatibility between the acrylic block copolymer (II) and the aromatic vinyl-conjugated diene block copolymer (I) is increased, and stable hot melt adhesiveness can be expressed. it can. In addition, the mass ratio of acrylic ester (b-1) and acrylic ester (b-2) can be determined by ¹ H-NMR measurement.

Examples of the combination of the acrylic ester (b-1) and the acrylic ester (b-2) used for the polymer block (B) include, for example, methyl acrylate / 2-ethylhexyl acrylate, ethyl acrylate / acrylic acid 2 -Ethylhexyl, n-butyl acrylate / 2-ethylhexyl acrylate, and the like. At this time, as the acrylic ester (b-1) and acrylic ester (b-2) to be used, the difference in solubility parameter between the acrylic ester (b-1) and the acrylic ester (b-2) is 0.3. More preferably, it is -2.5 (MPa) ^1/2 . Such solubility parameters are described in “POLYMER HANDBOOK Forth Edition”, VII pages 675-714 (Wiley Interscience, published in 1999) and “Polymer Engineering and Science”, 1974, pages 14-15. It can be calculated by the method described. Further, when the acrylic block copolymer (II) contains two or more polymer blocks (B), the combination of the acrylate units constituting the polymer blocks (B) is the same. It may or may not be.

  When the polymer block (B) is a copolymer containing both an acrylate (b-1) unit and an acrylate (b-2) unit, the acrylate (b-1) and It may be composed of a random copolymer of acrylic ester (b-2), may be composed of a block copolymer, or may be composed of a gradient copolymer. When the acrylic block copolymer (II) contains two or more polymer blocks (B), the structures of the polymer blocks (B) may be the same or different. Further, the proportion of the total units of the acrylic acid esters (b-1) and (b-2) contained in the polymer block (B) is preferably 60% by mass or more, and 80% by mass in the polymer block (B). The above is more preferable, and 90% by mass or more is more preferable.

  The glass transition temperature (Tg) of the polymer block (B) is preferably -100 to 30 ° C, more preferably -80 to 10 ° C, further preferably -70 to 0 ° C, Most preferably, it is −60 to −10 ° C. When the glass transition temperature is within this range, the hot melt pressure-sensitive adhesive composition of the present invention can have excellent adhesiveness at room temperature.

  The polymer block (A) and the polymer block (B) may contain respective structural units as long as the effects of the present invention are not impaired. Moreover, you may contain another structural unit as needed. Examples of such other structural unit monomers include vinyl monomers having a carboxyl group such as (meth) acrylic acid, crotonic acid, maleic acid, maleic anhydride, and fumaric acid; (meth) acrylamide, ( Vinyl monomers having a functional group such as (meth) acrylonitrile, vinyl acetate, vinyl chloride, vinylidene chloride; aromatic vinyl monomers such as styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene; Examples thereof include conjugated diene monomers such as butadiene and isoprene; olefin monomers such as ethylene, propylene, isobutene and octene; and lactone monomers such as ε-caprolactone and valerolactone. When these monomers are used, the amount is preferably 40% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less, based on the total mass of the monomers used for each polymer block. Used in.

  The acrylic block copolymer (II) used in the present invention may have other polymer blocks as needed in addition to the polymer block (A) and the polymer block (B). . Examples of such other polymer blocks include styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, acrylonitrile, methacrylonitrile, ethylene, propylene, isobutene, butadiene, isoprene, octene, vinyl acetate, anhydrous Examples thereof include a polymer block or copolymer block composed of monomers such as maleic acid, vinyl chloride and vinylidene chloride; a polymer block composed of polyethylene terephthalate, polylactic acid, polyurethane and polydimethylsiloxane. The polymer block also includes hydrogenated polymer blocks composed of conjugated diene compounds such as butadiene and isoprene.

The acrylic block copolymer (II) has a structure different from that of the polymer block (A): “(A)”; the polymer block (B): “(B)”; When the polymer block (B) is “(B ′)”, the general formula:
[(A)-(B)] n
[(A)-(B)] n-A
(B)-[(A)-(B)] n
[(A)-(B)] n- (B ′)
[(A)-(B)] n-Z
[(B)-(A)] n-Z
(In the formula, n is an integer of 1 to 30, Z is a coupling site (a coupling site after a coupling agent reacts with a polymer terminal to form a chemical bond,-represents a bond of each polymer block) In addition, when a plurality of A and B are included in the formula, they may be polymer blocks having the same structure or may be polymer blocks having different structures. It is preferable that it is represented. Here, the “different structure” means the monomer unit constituting the polymer block, the molecular weight, the molecular weight distribution, the stereoregularity, and the ratio of each monomer unit and the form of copolymerization (random , Gradient, block) means a different structure. The value of n is preferably 1 to 15, more preferably 1 to 8, and further preferably 1 to 4. Among the above structures, [(A)-(B)] n, [(A)-(B)] n- (A), (B)-[(A)-(B)] n, [(A )-(B)] A linear block copolymer represented by n- (B ′) is preferred, and a diblock copolymer represented by (A)-(B), a formula: (A) — The triblock copolymer represented by (B)-(B ′) and the triblock copolymer represented by the formula: (A)-(B)-(A) are the hot melt pressure-sensitive adhesive composition. More preferable from the viewpoint of excellent adhesion durability.

  The acrylic block copolymer (II) preferably has a total number average molecular weight (Mn) of 10,000 to 300,000. Among them, from the viewpoint of productivity when the hot melt pressure-sensitive adhesive composition of the present invention is formed into a film by heating and melting, such as a hot melt coating method, a T-die method, an inflation method, a calender molding method, a lamination method, The Mn is more preferably 10,000 to 200,000. Furthermore, when used as a pressure-sensitive adhesive tape or pressure-sensitive adhesive film using the hot melt pressure-sensitive adhesive composition of the present invention, contamination of the adherend during re-peeling is reduced. From the point which can be performed, 20,000-150,000 are more preferable, and 50,000-90,000 are especially preferable.

  The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the entire acrylic block copolymer (II) is preferably 1.0 to 1.5. It is more preferable that it is 1.0-1.4 from the point which is excellent in adhesion durability when it is set as a hot-melt adhesive composition, It is more preferable that it is 1.0-1.3, 1.0-1 .25 is particularly preferred.

The content of the polymer block (A) in the acrylic block copolymer (II) is preferably 5 to 50% by mass, and when used as a hot melt pressure-sensitive adhesive composition, the tackiness and aggregation at room temperature. From the viewpoint of force, the content of the polymer block (A) is preferably 10 to 50% by mass, more preferably 10 to 40% by mass, further preferably 10 to 35% by mass, It is particularly preferably 10 to 25% by mass.
Moreover, it is preferable that content of the polymer block (B) in the said acrylic block copolymer (II) used for this invention is 95-50 mass%, and 90-50 mass% from the same viewpoint as the above. It is more preferable that it is 90-60 mass%, it is still more preferable that it is 90-65 mass%, and it is especially preferable that it is 90-75 mass%.

  The method for producing the acrylic block copolymer (II) used in the present invention is not particularly limited as long as a polymer satisfying the conditions of the present invention is obtained, and a method according to a known method is adopted. be able to. In general, as a method of obtaining a block copolymer having a narrow molecular weight distribution, a method of living polymerizing a monomer as a constituent unit is used. Examples of such living polymerization methods include a method of living polymerization using an organic rare earth metal complex as a polymerization initiator (see Patent Document 4), and an alkali metal or alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator. A method of living anion polymerization in the presence of a mineral salt such as (see Patent Document 5), a method of living anion polymerization using an organic alkali metal compound as a polymerization initiator in the presence of an organoaluminum compound (see Patent Document 6), An atom transfer radical polymerization method (ATRP) (see Non-Patent Document 1) and the like can be mentioned.

  Among the above production methods, the method of living anion polymerization using an organoalkali metal compound as a polymerization initiator in the presence of an organoaluminum compound makes the resulting block copolymer highly transparent, has little residual monomer and has an odor. When it is used as a hot-melt pressure-sensitive adhesive composition, the generation of bubbles after bonding can be suppressed, which is preferable. Moreover, the molecular structure of the methacrylic acid ester polymer block is highly syndiotactic, which is preferable from the viewpoint of improving the heat resistance of the hot-melt pressure-sensitive adhesive composition.

As the organoaluminum compound, for example, the following general formula (3)
AlR ³ R ⁴ R ⁵ (3)
Wherein R ³ , R ⁴ and R ⁵ are each independently an alkyl group which may have a substituent, an cycloalkyl group which may have a substituent, or an aryl which may have a substituent. A group, an aralkyl group which may have a substituent, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent or an N, N-disubstituted amino group, or R ³ is any of the groups described above, and R ⁴ and R ⁵ together form an aryleneoxy group which may have a substituent.)
The organoaluminum compound represented by these is mentioned.

  As the organoaluminum compound represented by the general formula (3), isobutylbis (2,6-ditert-butyl-4-methylphenoxy) aluminum is used from the viewpoint of high living property of polymerization and easy handling. And isobutylbis (2,6-ditert-butylphenoxy) aluminum, isobutyl [2,2′-methylenebis (4-methyl-6-tert-butylphenoxy)] aluminum and the like are preferable.

  Examples of the organic alkali metal compounds include alkyl lithium and alkyl dilithium such as n-butyl lithium, sec-butyl lithium, isobutyl lithium, tert-butyl lithium, n-pentyl lithium, and tetramethylene dilithium; phenyl lithium, p -Aryllithium and aryldilithium such as tolyllithium and lithium naphthalene; aralkyllithium and aralkyldilithium such as dilithium produced by the reaction of benzyllithium, diphenylmethyllithium, diisopropenylbenzene and butyllithium; lithium such as lithium dimethylamide Amides; lithium alkoxides such as methoxylithium and ethoxylithium are listed. These may be used alone or in combination of two or more. Among these, alkyl lithium is preferable because of high polymerization initiation efficiency, among which tert-butyl lithium and sec-butyl lithium are more preferable, and sec-butyl lithium is more preferable.

  The living anionic polymerization is usually performed in the presence of a solvent inert to the polymerization reaction. Examples of the solvent include aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated hydrocarbons such as chloroform, methylene chloride, and carbon tetrachloride; ethers such as tetrahydrofuran and diethyl ether.

  The acrylic block copolymer (II) has, for example, a desired polymer block (polymer block (A), polymer block (B), etc.) at a desired living polymer terminal obtained by polymerizing monomers. After repeating the process of forming a desired number of times, it can be produced by stopping the polymerization reaction. Specifically, for example, in the presence of an organoaluminum compound, a first step of polymerizing a monomer that forms the first polymer block with a polymerization initiator composed of an organic alkali metal compound, the second polymer block The polymer obtained through a plurality of polymerization steps including a second step of polymerizing the monomer to be formed and a third step of polymerizing the monomer for forming the third polymer block as necessary. Acrylic block copolymer (II) can be produced by reacting the active terminal with alcohol or the like to stop the polymerization reaction. According to the above method, a binary block (diblock) copolymer comprising a polymer block (A) -polymer block (B); a polymer block (A) -polymer block (B) -heavy Polymer block (A), ternary block (triblock) copolymer comprising polymer block (A) -polymer block (B) -polymer block (B '); polymer block (A) -polymer A quaternary block copolymer comprising block (B) -polymer block (A) -polymer block (B) can be produced.

  As polymerization temperature, when forming a polymer block (A), 0-100 degreeC is preferable, and when forming a polymer block (B), -50-50 degreeC is preferable. When the polymerization temperature is lower than the above range, the progress of the reaction is slow, and it takes a long time to complete the reaction. On the other hand, when the polymerization temperature is higher than the above range, the deactivation of the living polymer ends increases, the molecular weight distribution becomes wide, and the desired block copolymer cannot be obtained. The polymer block (A) and the polymer block (B) can be polymerized in the range of 1 second to 20 hours, respectively.

[Hot melt adhesive composition]
In the hot melt pressure-sensitive adhesive composition of the present invention, the mass ratio of aromatic vinyl-conjugated diene block copolymer (I): acrylic block copolymer (II) is in the range of 99: 1 to 41:59. . By including the aromatic vinyl-conjugated diene block copolymer (I) and the acrylic block copolymer (II) at such a mass ratio, a uniform and stable hot-melt coating becomes possible. In addition to being excellent in the adhesive strength to an adherend having a low thickness, contamination of the adherend due to the adhesive during re-peeling is reduced. Aromatic vinyl-conjugated diene block copolymer (I): Acrylic block copolymer (I) because it has excellent adhesion to the adherend and is less susceptible to contamination of the adherend during re-peeling, etc. The mass ratio of II) is preferably in the range of 90:10 to 51:49, and more preferably in the range of 90:10 to 60:40.

  The hot melt pressure-sensitive adhesive composition of the present invention is within the range not impairing the effects of the present invention, other polymers, tackifying resins, softeners, waxes, plasticizers, antioxidants, heat stabilizers, light stabilizers, Additives such as an antistatic agent, a flame retardant, a foaming agent, a coloring agent, a dyeing agent, a refractive index adjusting agent, a filler, and a curing agent may be contained. These other polymers and additives may be included in one kind or in two or more kinds.

  Examples of the other polymer include acrylic resins excluding the acrylic block copolymer (II) in the present specification, such as polymethyl methacrylate and (meth) acrylic acid ester copolymers; polyethylene, polypropylene, Polybutene-1, poly-4-methylpentene-1, polynorbornene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid copolymer, etc. Olefin resin: polystyrene, styrene-maleic anhydride copolymer, high impact polystyrene, styrene-methyl methacrylate copolymer, AS resin, ABS resin, AES resin, AAS resin, ACS resin, MBS resin and other styrene resins ; Polyethylene terephthalate, polybutylene terf Polyester resins such as rate and polylactic acid; polyamides such as nylon 6, nylon 66 and polyamide elastomer; polycarbonate; polyvinyl chloride; polyvinylidene chloride; polyvinyl alcohol; ethylene-vinyl alcohol copolymer; polyacetal; Modified polyphenylene ether; polyphenylene sulfide; silicone rubber modified resin; acrylic rubber; silicone rubber; olefin rubber such as IR, EPR and EPDM.

  When the hot-melt pressure-sensitive adhesive composition of the present invention contains a tackifying resin, it is preferable because adjustment of tack, adhesive force and holding force is facilitated. Moreover, it may contribute also to the compatibility improvement of aromatic vinyl-conjugated diene type block copolymer (I) and acrylic type block copolymer (II). Examples of the tackifying resin include natural resins such as rosin resins and terpene resins; petroleum resins, hydrogenated (hereinafter sometimes referred to as “hydrogenated”) petroleum resins, styrene resins, and coumarone-indene resins. And synthetic resins such as phenol resins and xylene resins. When the tackifier resin is contained, the content thereof is aromatic vinyl-conjugated diene block copolymer (I) and acrylic block copolymer (II) from the viewpoint of adhesive strength and adhesion durability. It is preferable that it is 1-500 mass parts with respect to a total of 100 mass parts, It is more preferable that it is 5-400 mass parts, It is more preferable that it is 10-300 mass parts, It is 20-200 mass parts Is particularly preferable, and is most preferably 30 to 150 parts by mass.

  Examples of the rosin resin include rosins such as gum rosin, tall oil rosin and wood rosin; modified rosins such as hydrogenated rosin, disproportionated rosin and polymerized rosin; rosin, glycerin ester of modified rosin, pentaerythritol ester, etc. Examples thereof include rosin ester resins. Specific examples of the rosin resin include Pine Crystal KE-100, Pine Crystal KE-311, Pine Crystal KE-359, Pine Crystal KE-604, Pine Crystal D-6250 (all manufactured by Arakawa Chemical Industries, Ltd.); Foral 85, Foral 105, Staybelite Ester 5 (all are manufactured by Pinova), and the like.

  Examples of the terpene resin include terpene resins mainly composed of α-pinene, β-pinene, dipentene, etc., aromatic modified terpene resins, hydrogenated terpene resins, terpene phenol resins, and the like. Specific examples of the terpene resin include Tamanol 901 (Arakawa Chemical Industries, Ltd.); Clearon series, YS Polyster series, YS resin series (all manufactured by Yasuhara Chemical Co., Ltd.) and the like.

Examples such as the (hydrogenated) petroleum resin, for example, (hydrogenated) aliphatic (C ₅ series) petroleum resin, (hydrogenated) aromatic (C ₉ series) petroleum resin, (hydrogenated) copolymeric (C ₅ / C ₉ series) petroleum resin, (hydrogenated) dicyclopentadiene series petroleum resin, alicyclic saturated hydrocarbon resin and the like. Specific examples of the above (hydrogenated) petroleum resin include Alcon M series, Alcon P series (manufactured by Arakawa Chemical Industries, Ltd.) and the like.

  Examples of the styrene resin include poly α-methylstyrene, α-methylstyrene / styrene copolymer, styrene monomer / aliphatic monomer copolymer, and styrene monomer / α-methyl. Examples thereof include styrene / aliphatic monomer copolymers, styrene monomer copolymers, and styrene monomer / aromatic monomer copolymers. Specific examples of the styrenic resin include FTR6000 series and FTR7000 series (manufactured by Mitsui Chemicals, Inc.).

  Among the above tackifying resins, compatibility with the polymer block (Q) of the aromatic vinyl-conjugated diene block copolymer (I) and the polymer block (B) of the acrylic block copolymer (II) It is desirable to use a tackifier resin that excels in resistance. By using such a tackifier resin, the adherence dependency of the adhesive force is reduced, and from a low polarity adherend such as polyolefin to a highly polar adherend such as glass, stainless steel, acrylic, Appropriate adhesive force is expressed with respect to adherends of various polarities, and at the time of peeling, the adherend can be peeled smoothly without being contaminated. Furthermore, the morphology at the time of melting of the hot melt pressure-sensitive adhesive composition is stabilized, and a more uniform and stable hot melt coating is possible.

  As a method for determining whether the tackifier resin is compatible or incompatible with the polymer block (Q) of the aromatic vinyl-conjugated diene block copolymer (I), a method based on dynamic viscoelasticity measurement is used. is there. That is, the tackifying resin and the aromatic vinyl-conjugated diene block copolymer (I) were mixed at 20:80 (mass ratio), and the temperature dispersion measurement of dynamic viscoelasticity was performed on this mixture to obtain a polymer block ( The peak temperature of the loss tangent (tan δ) derived from the glass transition of Q) is closer to the glass transition temperature of the tackifying resin than the aromatic vinyl-conjugated diene block copolymer (I) alone before mixing. The case where it shifted can be determined as compatible, and the case where it is equivalent without shifting can be determined as incompatible.

  Similarly, as a method for determining whether the tackifying resin is compatible or incompatible with the polymer block (B) of the acrylic block copolymer (II), the tackifying resin and the acrylic block are used. Copolymer (II) was mixed at a ratio of 20:80 (mass ratio), the temperature dispersion measurement of dynamic viscoelasticity was performed on this mixture, and the loss tangent (tan δ) derived from the glass transition of the polymer block (B) was measured. When the peak temperature is shifted toward the glass transition temperature of the tackifier resin compared to the acrylic block copolymer (II) alone before mixing, it is judged as compatible, and when it is equivalent without shifting Can be determined as incompatible.

  Among the above tackifying resins, rosin resins, terpene resins, and aromatic petroleum resins are preferable from the viewpoint of excellent compatibility. Among them, rosin resins and aromatic petroleum resins are preferable from the viewpoint of increasing tackiness, and rosin A rosin ester resin is more preferable. In the case of rosin-based resins, disproportionated or hydrogenated rosins that have been purified by operations such as distillation, recrystallization, and extraction are more preferable from the viewpoint of suppressing light deterioration, coloring, and generation of bubbles due to impurities. These may be used alone or in combination of two or more. Moreover, about the softening point of the said tackifying resin, the thing of 50-150 degreeC is preferable from the point which expresses high adhesive force.

  Further, a tackifying resin that is liquid at room temperature can also be used. Suppressing separation of the aromatic vinyl-conjugated diene block copolymer (I) and the acrylic block copolymer (II) in the hot melt pressure-sensitive adhesive composition at the time of melting, uniform and stable hot melt coating From the viewpoint of being able to work, the liquid tackifier resin is preferably a rosin resin, a xylene resin, or a terpene resin, and more preferably a rosin resin or a xylene resin. Examples of the liquid rosin resin include SYVALITE RE10L (manufactured by Arizona CHEMICAL), Superester L (manufactured by Arakawa Chemical Industries), and ester gum AT (manufactured by Arakawa Chemical Industries). Examples of the liquid xylene-based resin include NICANOL Y-1000 (manufactured by Fudo), NIKANOLL LLL (manufactured by Fudou), NIKANOL L (manufactured by Fudou), and the like. These may be used alone or in combination of two or more. In addition, the liquid tackifying resin may be used in combination with a tackifying resin having a softening point of 50 to 150 ° C. In this case, both high adhesive force and stable hot melt coating can be achieved.

  Examples of the plasticizer include phthalates such as dibutyl phthalate, di-n-octyl phthalate, bis-2-ethylhexyl phthalate, di-n-decyl phthalate, diisodecyl phthalate, bis-2-ethylhexyl sebacate, di Fatty acid esters such as sebacic acid esters such as n-butyl sebacate, azelaic acid esters such as bis-2-ethylhexyl azelate, adipic acid esters such as bis-2-ethylhexyl adipate and di-n-octyl adipate; Paraffins such as chlorinated paraffins; Glycols such as polypropylene glycol; Epoxy polymer plasticizers such as epoxidized soybean oil and epoxidized linseed oil; Phosphate esters such as trioctyl phosphate and triphenyl phosphate Phosphites such as triphenyl phosphite; acrylic oligomers such as n-butyl poly (meth) acrylate and 2-ethylhexyl poly (meth) acrylate; liquid polybutene; liquid polyisobutylene; liquid polyisoprene; process Examples include oil. Among these, process oil is preferable from the viewpoint of excellent adhesive strength. Specific examples of the process oil include naphthenic oils such as SUNPURE N90 and NX90, SUNTHENE series (Nihon Sun Oil Co., Ltd.); Diana Process Oil PW series (Idemitsu Kosan Co., Ltd.), SUNPURE LW70 and P series. Paraffinic oils such as (manufactured by Japan Sun Oil Co., Ltd.); aroma oils such as JSO AROMA 790 (manufactured by Japan Sun Oil Co., Ltd.), Vivatec 500 (manufactured by H & R), and the like. These may be used alone or in combination of two or more.

  Examples of the filler include inorganic fibers such as glass fibers and carbon fibers and organic fibers; inorganic fillers such as calcium carbonate, talc, carbon black, titanium oxide, silica, clay, barium sulfate, and magnesium carbonate. When inorganic fibers and organic fibers are contained, durability is imparted to the obtained hot-melt pressure-sensitive adhesive composition. When the inorganic filler is contained, heat resistance and weather resistance are imparted to the obtained hot melt pressure-sensitive adhesive composition.

  When the hot-melt pressure-sensitive adhesive composition of the present invention is used together with a curing agent, it can be suitably used as a UV-curable hot-melt pressure-sensitive adhesive. Examples of the curing agent include photocuring agents such as UV curing agents, thermosetting agents, and the like, and examples include benzoins, benzoin ethers, benzophenones, anthraquinones, benzyls, acetophenones, and diacetyls. . Specifically, benzoin, α-methylol benzoin, α-t-butyl benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, α-methylol benzoin methyl ether, α -Methoxybenzoin methyl ether, benzoin phenyl ether, benzophenone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, benzyl, 2,2-dimethoxy-1,2-diphenylethane-1-one (2,2 -Dimethoxy-2-phenylacetophenone), diacetyl and the like. A hardening | curing agent may be used individually by 1 type, and may be used in combination of 2 or more type. In order to enhance the effect of these curing agents, monomers such as (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamide, (meth) acrylamide derivative, vinyl ester, vinyl ether, styrene derivative; An oligomer containing a monomer as a constituent component may be further added. In addition to these monomers, a cross-linking agent composed of a bifunctional or higher functional monomer or oligomer may be added.

  The production method of the hot melt pressure-sensitive adhesive composition of the present invention is not particularly limited, and for example, each component is 100 to 250 by using a known mixing or kneading apparatus such as a kneader ruder, an extruder, a mixing roll, or a Banbury mixer. It can be produced by mixing at a temperature in the range of ° C. Moreover, after dissolving each component in an organic solvent and mixing, you may manufacture by distilling off this organic solvent. The obtained composition can be heated and melted and used as a hot melt adhesive. When the hot melt pressure-sensitive adhesive composition of the present invention is used after being melted by heating, the melt viscosity is preferably low from the viewpoint of processability and handleability. For example, in the case of performing hot melt processing, 190 ° C. The melt viscosity before and after is preferably 200,000 mPa · s or less, more preferably 100,000 mPa · s or less, further preferably 50,000 mPa · s or less, and 30,000 mPa · s or less. It is particularly preferred that

  Moreover, the hot-melt pressure-sensitive adhesive composition of the present invention can be provided in a form excellent in handleability when performing hot-melt coating such as blocks, pellets, and sticks. For example, in the case of pellet form, the hot melt pressure-sensitive adhesive composition of the present invention is melt-kneaded with a roll kneader, then supplied to the extruder and extruded into strands from the pores of the die. According to the hot melt pressure-sensitive adhesive composition of the present invention, the anti-sticking agent is solidified through a cooling water bath dispersed therein and then cut into pellets, and if necessary, the anti-sticking agent is added to the pellets. Pellets can be obtained. Instead of the roll kneader, melt kneading and extrusion can be simultaneously performed using a twin screw extruder. In addition, immediately after extrusion, it is cut with a rotary blade on the die surface to form a pellet, and if necessary, it is solidified by immersion in cooling water in which an anti-sticking agent is dispersed, and then dehydrated, and if necessary, the pellet The pellets of the hot-melt pressure-sensitive adhesive composition of the present invention can also be obtained by adding an anti-sticking agent to.

  The anti-sticking agent is used for preventing the pellets of the hot melt pressure-sensitive adhesive composition of the present invention from sticking. Specific examples of the anti-sticking agent include fatty acids such as stearic acid and palmitic acid; fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate and sodium palmitate; polyethylene wax, polypropylene wax, montan Waxes such as acid wax; low molecular weight polyolefin such as low molecular weight polyethylene and low molecular weight polypropylene; acrylic resin powder; polyorganosiloxane such as dimethylpolysiloxane; octadecylamine, alkyl phosphate, fatty acid ester, ethylenebisstearylamide, etc. Amide resin powders or aqueous dispersions, fluororesin powders such as tetrafluoroethylene resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, silica and the like.

[Adhesive tape and adhesive film]
The hot-melt pressure-sensitive adhesive composition of the present invention is suitably used for pressure-sensitive adhesive products (for example, pressure-sensitive adhesive tapes or pressure-sensitive adhesive films) in the form of a laminate including a pressure-sensitive adhesive layer made of the hot-melt pressure-sensitive adhesive composition.

In order to form the pressure-sensitive adhesive layer, when the hot-melt pressure-sensitive adhesive composition of the present invention is used by heating and melting, for example, a hot-melt coating method, a T-die method, an inflation method, a calendering method, a lamination method, etc. are used. Can be formed into a sheet shape or a film shape. For example, an adhesive tape or an adhesive film can be produced by hot-melt coating the hot melt adhesive composition of the present invention on a tape or film substrate. The application amount of the hot melt pressure-sensitive adhesive composition can be set to, for example, 5 to 200 g / m ² .

  The laminate is obtained by laminating a layer (adhesive layer) comprising the hot melt pressure-sensitive adhesive composition of the present invention and various base materials such as paper, cellophane, plastic material, glass, cloth, wood and metal. It is done. Examples of the plastic material include polyethylene terephthalate, triacetyl cellulose, polyvinyl alcohol, cycloolefin resin, styrene-methyl methacrylate copolymer, polypropylene, polyethylene, polyvinyl chloride, ethylene-vinyl acetate copolymer, polycarbonate, polymethacrylic acid. Examples include, but are not limited to, a base material layer made of a polymer such as methyl acid, polyethylene, or polypropylene, or a mixture of two or more of these polymers. The polymer may be a copolymer obtained by copolymerizing various monomers.

  As a structure of the said laminated body, for example, from the two-layer structure of the adhesive layer and base material layer which consist of a hot-melt adhesive composition of this invention, from two base material layers and the hot-melt adhesive composition of this invention A three-layer structure (base material layer / pressure-sensitive adhesive layer / base material layer), two different pressure-sensitive adhesive layers (a) comprising the base material layer and the hot melt pressure-sensitive adhesive composition of the present invention, and pressure-sensitive adhesive 4 layer constitution of base material layer (b) and base material layer (base material layer / adhesive layer (a) / adhesive layer (b) / base material layer), base material layer and hot melt adhesive composition of the present invention Four-layer structure of a pressure-sensitive adhesive layer (a) made of a product, a pressure-sensitive adhesive layer (c) made of another material, and a base material layer (base material layer / pressure-sensitive adhesive layer (a) / pressure-sensitive adhesive layer (c) / group Material layer), 3 layers of substrate layer and 2 layers of adhesive layer made of the hot-melt adhesive composition of the present invention (substrate layer / adhesive layer / base material layer / adhesive layer / base material) Layer) etc. But it is lower, but the invention is not limited thereto.

  Although it does not restrict | limit especially as thickness ratio of the said laminated body, It is preferable that it is the range of base material layer / adhesive layer = 1 / 1000-1000 / 1 from the adhesiveness of the adhesive product obtained, durability, and handleability. The range of 1/200 to 200/1 is more preferable.

  When producing the laminate, after forming the pressure-sensitive adhesive layer and the base material layer, they may be bonded together by a lamination method or the like, or the pressure-sensitive adhesive layer may be formed directly on the base material layer. The layer structure may be formed at a time by co-extrusion of the pressure-sensitive adhesive layer and the base material layer.

  In the laminated body of this invention, in order to improve the adhesive force of a base material layer and an adhesive layer, you may give surface treatments, such as a corona discharge process and a plasma discharge process, to the surface of a base material layer previously. Moreover, you may form an anchor layer in the surface of at least one of the said adhesive layer and a base material layer using resin etc. which have adhesiveness.

  Examples of the resin used for the anchor layer include an ethylene-vinyl acetate copolymer, an ethylene-methyl methacrylate copolymer, an ionomer, a block copolymer (for example, a styrene triblock copolymer such as SIS and SBS, and Diblock copolymer), ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, and the like. The anchor layer may be a single layer or two or more layers.

  When forming the anchor layer, the method is not particularly limited. For example, a method of forming the anchor layer by applying a solution containing the resin to the base material layer, a composition containing the resin to be the anchor layer, and the like. And a method of forming an anchor layer on the surface of the base material layer by T-die or the like after heating and melting.

When forming the anchor layer, the anchor layer and the pressure-sensitive adhesive layer may be integrally laminated on the surface of the base material layer by co-extrusion of the resin serving as the anchor layer and the hot melt pressure-sensitive adhesive composition of the present invention, A resin serving as an anchor layer and a hot melt pressure-sensitive adhesive composition may be sequentially laminated on the surface of the base material layer. Furthermore, when the base material layer is a plastic material, the plastic material to be the base material layer, the resin to be the anchor layer, and the hot melt pressure-sensitive adhesive composition may be coextruded at the same time.
In addition, in the pressure-sensitive adhesive tape or film for surface protection or masking, the hot melt pressure-sensitive adhesive composition of the present invention is applied to the anchor layer between the base material and the pressure-sensitive adhesive in order to increase the adhesion between the base material and the pressure-sensitive adhesive. Can also be used. In that case, the layer structure may be formed at a time by co-extrusion of the base material layer, the anchor layer, and the pressure-sensitive adhesive layer.

  The pressure-sensitive adhesive comprising the hot melt pressure-sensitive adhesive composition of the present invention can be used for various applications. The heat-sensitive adhesive film comprising the hot-melt pressure-sensitive adhesive composition can be used alone for various applications as a pressure-sensitive adhesive or a pressure-sensitive adhesive layer, and a laminate comprising a pressure-sensitive adhesive layer comprising the hot-melt pressure-sensitive adhesive composition is also available. It can be applied to various uses. For example, for surface protection, masking, shoes, binding, packaging / packaging, office, labeling, decoration / display, bookbinding, bonding, dicing tape, sealing, anticorrosion / waterproof, medical・ Adhesives for hygiene, glass scattering prevention, electrical insulation, electronic equipment holding and fixing, semiconductor manufacturing, optical display films, adhesive optical films, electromagnetic shielding, or sealing materials for electrical and electronic parts An adhesive tape, an adhesive film, etc. are mentioned. Specific examples are given below.

  Surface protective adhesives, adhesive tapes or films can be used for various materials such as metal, plastic, rubber, and wood. Specifically, for paint surfaces, metal plastic processing and deep drawing, automotive parts, optical Can be used for surface protection of members. Examples of the automobile member include a painted outer plate, a wheel, a mirror, a window, a light, and a light cover. Examples of the optical member include various image display devices such as a liquid crystal display, an organic EL display, a plasma display, and a field emission display; a polarizing film, a polarizing plate, a retardation plate, a light guide plate, a diffusion plate, an optical disc constituting film such as a DVD;・ Precise fine coated face plate for optical applications.

  Masking adhesives, tapes, films, etc. include: masking when manufacturing printed circuit boards and flexible printed circuit boards; masking when plating and soldering on electronic equipment; manufacturing of vehicles such as automobiles, vehicles and buildings These include masking when painting, printing, and civil engineering work.

  Examples of the pressure-sensitive adhesive for shoes include a pressure-sensitive adhesive used for adhesion between a shoe main body (upper) and a shoe sole (sole), a heel, an insole, a decoration portion, and the like, and adhesion between an outer sole and a midsole.

  Examples of binding applications include binding of wire harnesses, electric wires, cables, fibers, pipes, coils, windings, steel materials, ducts, plastic bags, foods, vegetables, and grooms. Packaging applications include heavy goods packaging, export packaging, cardboard box sealing, can seals, and the like. Office applications include general office work, sealing, book repair, drafting, and memos. Examples of label usage include price, product display, tag, POP, sticker, stripe, name plate, decoration, and advertisement.

  The labels include paper, processed paper (paper subjected to aluminum vapor deposition, aluminum lamination, varnishing, resin processing, etc.), paper such as synthetic paper; cellophane, plastic material, cloth, wood and metal The label which uses a film etc. as a base material is mentioned. Examples of the base material include high-quality paper, art paper, cast paper, thermal paper, foil paper; polyethylene terephthalate film, polyvinyl chloride film, OPP film, polylactic acid film, synthetic paper, synthetic paper thermal, and laminate film. Can be mentioned.

  Examples of the adherend of the label include plastic products such as plastic bottles and foamed plastic cases; paper and cardboard products such as cardboard boxes; glass products such as glass bottles; metal products; and other inorganic material products such as ceramics. It is done.

  Examples of decoration / display applications include danger display stickers, line tapes, wiring markings, phosphorescent tapes, and reflective sheets.

  Examples of adhesive optical film applications include polarizing films, polarizing plates, retardation films, viewing angle widening films, brightness enhancement films, antireflection films, antiglare films, color filters, light guide plates, diffusion films, prism sheets, electromagnetic wave shielding films , Near-infrared absorbing films, functional composite optical films, ITO bonding films, impact resistance imparting films, optical films having a pressure-sensitive adhesive layer formed on at least a part or all of one or both sides thereof, etc. Can be mentioned. Such an adhesive optical film includes a film in which an adhesive layer made of the hot melt adhesive composition of the present invention is formed on a protective film used for protecting the surface of the optical film. The adhesive optical film is suitably used for various image display devices such as liquid crystal display devices, PDPs, organic EL display devices, electronic paper, game machines, and mobile terminals.

  Examples of electrical insulation applications include protective coating or insulation of coils, interlayer insulation such as motors and transformers, and the like. Electronic device holding and fixing applications include carrier tape, packaging, CRT fixing, splicing, rib reinforcement, and the like. Examples of semiconductor manufacturing include protection of silicone wafers. Examples of bonding applications include various adhesive fields, automobiles, trains, electrical equipment, printing plate fixation, construction, nameplate fixation, general household use, rough surfaces, uneven surfaces, and adhesion to curved surfaces. Sealing applications include heat insulation, vibration proofing, waterproofing, moisture proofing, soundproofing or dustproof sealing. Examples of anticorrosion / waterproofing include gas, water pipe corrosion prevention, large-diameter pipe corrosion prevention, and civil engineering building corrosion prevention.

  For medical and hygiene applications, analgesic / anti-inflammatory agents (plasters, papps), cold patches, antipruritic patches, dermal softeners, and other transdermal absorption medicines; emergency adhesive plasters (with bactericides), surgical dressing / surgical tape, adhesive plasters, Various tape applications such as hemostatic bond, tape for human excrement disposal equipment (artificial anal fixation tape), suture tape, antibacterial tape, fixation taping, self-adhesive bandage, oral mucosa adhesive tape, sports tape, hair removal tape Cosmetic applications such as face packs, moisturizing sheets, and exfoliating packs; bonding applications of sanitary materials such as diapers and pet sheets; cooling sheets, thermal warmers, dustproofing, waterproofing, and pest capturing.

  As a sealing material application for electronic / electrical parts, a liquid crystal display, an organic EL display, an organic EL illumination, a solar cell, and the like can be given.

  Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to the following examples.

Aromatic vinyl-conjugated diene block copolymers (I-1) and acrylic block copolymers (II-1) to (II-4) used in Examples and Comparative Examples are the following synthesis examples. Synthesized by methods 1-5.

<< Synthesis Example 1 >> [Synthesis of Aromatic Vinyl-Conjugated Diene Block Copolymer (I-1)]
(1) After replacing the inside of a pressure vessel equipped with a stirrer having a volume of 1.5 liters with nitrogen, 680 g of cyclohexane and 0.54 g of a cyclohexane solution of sec-butyllithium containing 0.89 mmol of sec-butyllithium were added.
(2) Subsequently, 9.1 g of styrene was added thereto and stirred at 60 ° C. for 1 hour.
(3) Subsequently, 102 g of isoprene was added dropwise over 1 hour, followed by stirring at 60 ° C. for 1 hour.
(4) Furthermore, 9.1 g of styrene was added to this, and it stirred at 60 degreeC for 1 hour.
(5) After adding 1 g of methanol to stop the polymerization reaction, the obtained reaction solution was poured into 10 kg of a methanol / acetone mixed solution (methanol: acetone = 1: 1 (mass ratio)), and a precipitate was formed. Was precipitated. Thereafter, the precipitate was collected and dried to obtain 119 g of an aromatic vinyl-conjugated diene block copolymer (I-1).

<< Synthesis Example 2 >> [Synthesis of Acrylic Block Copolymer (II-1)]
(1) After replacing the inside of the 2 L three-necked flask with nitrogen, 870 g of toluene and 40 g of 1,2-dimethoxyethane were added while stirring at room temperature, followed by isobutylbis (2,6-di-t- 80 g of a toluene solution containing 40 mmol of (butyl-4-methylphenoxy) aluminum was added, and 3.5 g of a cyclohexane solution of sec-butyllithium containing 5.7 mmol of sec-butyllithium was further added.
(2) Subsequently, 22 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., 290 g of n-butyl acrylate was added dropwise over 2 hours, and the mixture was stirred at −30 ° C. for 5 minutes after the completion of the addition.
(4) After adding 4 g of methanol to stop the polymerization reaction, the resulting reaction solution was poured into 15 kg of methanol to precipitate a liquid precipitate. Thereafter, the liquid precipitate was collected and dried to obtain 311 g of an acrylic block copolymer (II-1).

<< Synthesis Example 3 >> [Synthesis of Acrylic Block Copolymer (II-2)]
(1) After replacing the inside of the 2 L three-necked flask with nitrogen, 870 g of toluene and 40 g of 1,2-dimethoxyethane were added while stirring at room temperature, followed by isobutylbis (2,6-di-t- 80 g of toluene solution containing 40 mmol of (butyl-4-methylphenoxy) aluminum was added, and 2.0 g of cyclohexane solution of sec-butyllithium containing 3.3 mmol of sec-butyllithium was further added.
(2) Subsequently, 34 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization solution was cooled to −30 ° C., 240 g of n-butyl acrylate was added dropwise over 2 hours, and the mixture was stirred at −30 ° C. for 5 minutes after the completion of the addition.
(4) Furthermore, 34 g of methyl methacrylate was added thereto and stirred overnight at room temperature.
(5) After adding 4 g of methanol to stop the polymerization reaction, the obtained reaction solution was poured into 15 kg of methanol to deposit a precipitate. Thereafter, the precipitate was collected and dried to obtain 307 g of an acrylic block copolymer (II-2).

<< Synthesis Example 4 >> [Synthesis of Acrylic Block Copolymer (II-3)]
(1) After replacing the inside of the 2 L three-necked flask with nitrogen, 870 g of toluene and 40 g of 1,2-dimethoxyethane were added while stirring at room temperature, followed by isobutylbis (2,6-di-t- 80 g of a toluene solution containing 40 mmol of (butyl-4-methylphenoxy) aluminum was added, and 2.5 g of a cyclohexane solution of sec-butyllithium containing 4.1 mmol of sec-butyllithium was further added.
(2) Subsequently, 33 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization liquid was cooled to −30 ° C., and a mixture of 120 g of n-butyl acrylate and 120 g of 2-ethylhexyl acrylate was added dropwise over 2 hours. Stir for minutes.
(4) Furthermore, 33 g of methyl methacrylate was added thereto and stirred overnight at room temperature.
(5) After adding 4 g of methanol to stop the polymerization reaction, the obtained reaction solution was poured into 15 kg of methanol to deposit a precipitate. Thereafter, the precipitate was collected and dried to obtain 305 g of an acrylic block copolymer (II-3).

<< Synthesis Example 5 >> [Synthesis of Acrylic Block Copolymer (II-4)]
(1) After replacing the inside of the 2 L three-necked flask with nitrogen, 870 g of toluene and 40 g of 1,2-dimethoxyethane were added while stirring at room temperature, followed by isobutylbis (2,6-di-t- 80 g of a toluene solution containing 40 mmol of (butyl-4-methylphenoxy) aluminum was added, and 2.7 g of a cyclohexane solution of sec-butyllithium containing 4.4 mmol of sec-butyllithium was further added.
(2) Subsequently, 36 g of methyl methacrylate was added thereto. The reaction solution was initially colored yellow, but became colorless after stirring for 60 minutes at room temperature.
(3) Subsequently, the internal temperature of the polymerization liquid was cooled to −30 ° C., 240 g of 2-ethylhexyl acrylate was added dropwise over 2 hours, and the mixture was stirred at −30 ° C. for 5 minutes after the completion of the addition.
(4) Further, 36 g of methyl methacrylate was added thereto, and the mixture was stirred overnight at room temperature.
(5) After adding 4 g of methanol to stop the polymerization reaction, the obtained reaction solution was poured into 15 kg of methanol to deposit a precipitate. Then, 311 g of acrylic block copolymer (II-4) was obtained by collecting the precipitate and drying it.

Structure of aromatic vinyl-conjugated diene block copolymer (I-1) obtained in Synthesis Example 1, content of each polymer block, number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight The distribution (Mw / Mn) is shown in Table 1.
Further, the structures of the acrylic block copolymers (II-1) to (II-4) obtained in Synthesis Examples 2 to 5, the content of each polymer block, the number average molecular weight (Mn), the weight average molecular weight ( Mw) and molecular weight distribution (Mw / Mn) are shown in Table 2.
Mw, Mn, Mw / Mn, and each polymer block of aromatic vinyl-conjugated diene block copolymer (I-1) and acrylic block copolymers (II-1) to (II-4) The content of was measured by the following method.

(1) Measurement of number average molecular weight (Mn), weight average molecular weight (Mw), molecular weight distribution (Mw / Mn) The molecular weight in terms of standard polystyrene was determined by gel permeation chromatography (hereinafter abbreviated as GPC).
・ Equipment: GPC equipment “HLC-8020” manufactured by Tosoh Corporation
・ Separation column: “TSKgel GMHXL”, “G4000HXL” and “G5000HXL” manufactured by Tosoh Corporation are connected in series. ・ Eluent: Tetrahydrofuran ・ Eluent flow rate: 1.0 ml / min ・ Column temperature: 40 ° C.
・ Detection method: Differential refractive index (RI)

(2) Measurement of content of each polymer block The content was determined by proton nuclear magnetic resonance spectroscopy ( ¹ H-NMR).
・ Apparatus: JEOL nuclear magnetic resonance apparatus “JNM-ECX400”
Solvent: deuterated chloroform In the ¹ H-NMR spectrum of the aromatic vinyl-conjugated diene block copolymer, signals of 4.6 to 4.8 ppm and 5.0 to 5.2 ppm are respectively 3 and 4 - is attributed to the isoprene units olefinic protons (C = CH ₂₎ and 1,4-isoprene units of olefinic protons (-CH = C), also signals 6.3~7.3ppm the styrene units Assigned to the benzene ring proton. The molar ratio of each monomer was determined from the ratio of these integral values, and this was converted into a mass ratio based on the molecular weight of the monomer unit to determine the content of each polymer block.
Further, in the ¹ H-NMR spectrum of the acrylic block copolymer, signals of 3.5 to 3.7 ppm and 3.8 to 4.1 ppm respectively represent ester groups (—O—CH ₃ ) of methyl methacrylate units. ) And an ester group of an n-butyl acrylate unit and an ester group (—O—CH ₂ —) of a ₂ -ethylhexyl acrylate unit. The molar ratio of each monomer was determined from the ratio of these integral values, and this was converted into a mass ratio based on the molecular weight of the monomer unit to determine the content of each polymer block.

In the examples and comparative examples, the following were used as the tackifier resin and the plasticizer.
Tackifying resin: trade name “Foral 85”, manufactured by Pinova, hydrogenated rosin ester resin, softening point 85 ° C., glass transition temperature about 38 ° C.
・ Plasticizer: Trade name “NX-90”, manufactured by Nippon San Oil Co., Ltd., naphthenic process oil

<< Examples 1 to 5, Comparative Example 1 >>
Aromatic vinyl-conjugated diene block copolymer (I-1) obtained in Synthesis Example 1 and acrylic block copolymers (II-1) to (II-4) obtained in Synthesis Examples 2-5 The above-mentioned tackifying resin and plasticizer were melt-mixed (temperature 180 ° C.) in the proportions of the composition shown in Table 3 to obtain a hot melt pressure-sensitive adhesive composition.
Next, the obtained hot melt adhesive composition was hot melt coated (coating temperature 180 ° C.) to a thickness of 25 μm on a polyethylene terephthalate (PET) film (Ester film E5000 manufactured by Toyobo Co., Ltd., thickness 50 μm). A pressure-sensitive adhesive film having a structure of PET film layer / pressure-sensitive adhesive layer was obtained. The obtained pressure-sensitive adhesive film was cut into a width of 25 mm and a length of 150 mm to form a pressure-sensitive adhesive tape, and the pressure-sensitive adhesive properties were evaluated by the following methods.

[Testing method for adhesive strength]
The pressure-sensitive adhesive tape is pressure-bonded to an adherend (glass plate, stainless steel plate (SUS304), acrylic plate (PMMA), polyethylene plate) at 23 ° C. using a 2 kg rubber roller, and then 24 ° C. under conditions of 23 ° C. and 50% RH. It was stored for a period of time, and the adhesive strength was measured by peeling 180 ° at a speed of 300 mm / min. Measurements were made in accordance with JIS Z0237 except for the above conditions.

[Evaluation of contamination on adherend]
After measuring the adhesive strength by the above-mentioned method, the mark on which the adhesive tape on the surface of the adherend was applied was visually observed, and the contamination on the adherend was evaluated according to the following criteria.
○: No trace of adhesive tape applied to the adherend surface. (No contamination)
(Triangle | delta): The trace which stuck the adhesive tape on the to-be-adhered body surface is seen weakly. (Slightly contaminated)
X: The mark which stuck the adhesive tape on the adherend surface is seen strongly. (Contaminated)

<< Comparative Example 2 >>
Aromatic vinyl-conjugated diene block copolymer (I-1) obtained in Synthesis Example 1, acrylic block copolymer (II-2) obtained in Synthesis Example 3, the tackifying resin and the plasticizer Were melt-mixed (temperature: 180 ° C.) at the composition ratio shown in Table 3 to obtain a hot-melt pressure-sensitive adhesive composition.
Subsequently, when the obtained hot-melt pressure-sensitive adhesive composition was subjected to hot-melt coating (coating temperature 180 ° C.) on a polyethylene terephthalate (PET) film (Ester film E5000 manufactured by Toyobo Co., Ltd., thickness 50 μm), Since the agent composition was separated in the melting tank and the composition became non-uniform, it was not possible to uniformly apply hot melt coating.

  From the results in Table 3, it can be seen that the hot-melt pressure-sensitive adhesive composition satisfying the provisions of the present invention in Examples 1 to 5 has higher adhesive strength to the polyethylene plate than Comparative Example 1. In addition, it can be seen that sufficient adhesion is exhibited with respect to any of a glass plate, a stainless steel plate, and an acrylic plate, and at the time of peeling, the adherend can be smoothly peeled without being contaminated. Therefore, the hot-melt pressure-sensitive adhesive composition that satisfies the provisions of the present invention adheres sufficiently strongly to various adherends during use, and can be easily peeled off after use without contaminating the adherends. It can be suitably used as an adhesive layer for adhesive tapes and adhesive films.

  The hot-melt pressure-sensitive adhesive composition of the present invention exhibits sufficient adhesive strength to adherends with low polarity such as adherends made of polyolefins such as polyethylene and polypropylene, which have been difficult to stick in the past. In addition, it exhibits an appropriate adhesive force to other adherends such as glass, stainless steel, and acrylic, and can be peeled smoothly without contaminating the adherend during peeling. Therefore, the hot melt pressure-sensitive adhesive composition of the present invention is useful as various pressure-sensitive adhesive products such as pressure-sensitive adhesive tapes and pressure-sensitive adhesive films.

Claims (13)

At least one polymer block (P) comprising an aromatic vinyl compound unit and at least one polymer comprising a conjugated diene compound unit in which at least a part of the carbon-carbon unsaturated double bond may be hydrogenated An aromatic vinyl-conjugated diene block copolymer (I) having a block (Q) and a number average molecular weight of 20,000 to 500,000;
Hot containing an acrylic block copolymer (II) having at least one polymer block (A) composed of methacrylate units and at least one polymer block (B) composed of acrylate units A melt adhesive composition comprising:
A hot-melt pressure-sensitive adhesive composition having a mass ratio of aromatic vinyl-conjugated diene block copolymer (I): acrylic block copolymer (II) of 99: 1 to 41:59.   The hot-melt pressure-sensitive adhesive composition according to claim 1, wherein the content of the polymer block (A) in the acrylic block copolymer (II) is 5 to 50% by mass.   The acrylic block copolymer (II) is a diblock copolymer represented by the formula: (A)-(B), a triblock represented by the formula: (A)-(B)-(B ′). A block copolymer and a triblock copolymer represented by the formula: (A)-(B)-(A) [wherein (A) is a polymer block (A) comprising methacrylic acid ester units] , (B) represents a polymer block (B) composed of an acrylate ester unit, (B ′) represents a polymer block (B) composed of an acrylate ester unit having a structure different from (B), and − represents each weight Shows the combined hand of the combined block. The hot melt pressure-sensitive adhesive composition according to claim 1 or 2, which is at least one acrylic block copolymer selected from the group consisting of: Acrylic acid ester units constituting the polymer block (B)
Formula ^{_{CH 2 = CH-COOR 1 (}} 1)
(Wherein R ¹ represents an organic group having 1 to 5 carbon atoms) and an acrylic ester (b-1) represented by:
Formula ^{_{CH 2 = CH-COOR 2 (}} 2)
(Wherein R ² represents an organic group having 6 to 12 carbon atoms) and is a structural unit derived from an acrylate ester (b-2), and the acrylate ester (b-1) and The mass ratio [(b-1) / (b-2)] of the acrylate ester (b-2) is 70/30 to 0/100, The hot melt according to any one of claims 1 to 3. Adhesive composition.   The number average molecular weight of the polymer block (P) in the aromatic vinyl-conjugated diene block copolymer (I) is 2,500 to 100,000, and the number average molecular weight of the polymer block (Q) is 10, It is 000-400,000, The hot-melt adhesive composition of any one of Claims 1-4.   The hot-melt pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein the aromatic vinyl compound constituting the polymer block (P) is at least one selected from styrene and α-methylstyrene.   7. The mass ratio of aromatic vinyl-conjugated diene block copolymer (I): acrylic block copolymer (II) is 90:10 to 51:49, according to claim 1. Hot melt pressure-sensitive adhesive composition.   Furthermore, the hot-melt adhesive composition of any one of Claims 1-7 containing tackifying resin.   The tackifying resin is compatible with the polymer block (Q) of the aromatic vinyl-conjugated diene block copolymer (I) and the polymer block (B) of the acrylic block copolymer (II). The hot-melt pressure-sensitive adhesive composition according to claim 8.   The hot melt pressure-sensitive adhesive composition according to claim 8 or 9, wherein the tackifying resin is a rosin resin.   The laminated body which has an adhesion layer which consists of a hot-melt-adhesive composition of any one of Claims 1-10.   The adhesive tape which has an adhesion layer which consists of a hot-melt-adhesive composition of any one of Claims 1-10.   The adhesive film which has the adhesion layer which consists of a hot-melt adhesive composition of any one of Claims 1-10.