JP7354617B2 - electrical insulation tape - Google Patents

Description

The present invention relates to an electrical insulating tape, and more particularly to an electrical insulating tape that has low odor, suppresses changes in adhesive strength over time, and has excellent holding power.

Hot-melt adhesives solidify in a short time, making it possible to efficiently bond various products together.Furthermore, since they do not require solvents, they are highly safe for the human body. Since it is an adhesive, it is used in various fields. For example, adhesives are used to seal paper, cardboard, and film packaging for food, clothing, electronic devices, and cosmetics, and when manufacturing sanitary products such as disposable diapers and sanitary products, adhesives are used to bond the components that make up these products. Hot-melt pressure-sensitive adhesives are used as adhesives for the adhesive layer of adhesive tapes and labels.

As a hot melt adhesive, for example, Patent Document 1 describes a block copolymer A represented by the following general formula (A) and a block copolymer B represented by the following general formula (B). A hot melt adhesive composition comprising a block copolymer composition and a tackifying resin, the weight of block copolymer A and block copolymer B in the block copolymer composition. A hot melt adhesive composition has been proposed in which the ratio (A/B) is 10/90 to 90/10 and the aromatic monomer unit content of the tackifier resin is 1 to 70% by weight. There is.
Ar1 ^a -D ^a -Ar2 ^a (A)
(Ar ^b −D ^b )n−X (B)
(In general formulas (A) and (B), Ar1 ^a and Ar ^b are aromatic vinyl polymer blocks with a weight average molecular weight of 6,000 to 20,000, respectively, and Ar2 ^a is an aromatic vinyl polymer block with a weight average molecular weight of 22,000 to 400,000. is an aromatic vinyl polymer block, D ^a and D ^b are each a conjugated diene polymer block with a vinyl bond content of 1 to 20 mol%, and X is a single bond or a residue of a coupling agent; , n is an integer greater than or equal to 2.)

On the other hand, when hot-melt adhesive compositions are used as adhesives for electrical insulating tapes, odor may be a problem. There was a need to reduce this.

Japanese Patent Application Publication No. 2010-254983

The present invention has been made in view of these circumstances, and its purpose is to provide an electrical insulating tape that has low odor, suppresses changes in adhesive strength over time, and has excellent holding power.

The present inventors conducted studies to achieve the above object, and found that in an electrical insulating tape comprising a hot melt adhesive composition and a base material, aromatic A hot melt adhesive composition containing a vinyl block copolymer and a hydrogenated hydrocarbon resin, the toluene volatile content and the total volatile component content being suppressed to a predetermined amount or less, and the stainless steel sheet The inventors have discovered that the above object can be achieved by using a material whose peel adhesive strength is within a specific range, and have completed the present invention.

That is, according to the present invention, there is provided an electrical insulating tape comprising a hot melt adhesive composition and a base material, wherein the hot melt adhesive composition comprises an aromatic vinyl block copolymer, Hydrogenated hydrocarbon resin, the toluene volatile content of the hot melt adhesive composition when heated at 65°C for 2 hours is 260 μg/m ³ or less, the total volatile content is 15, 000 μg/m ³ or less, and the peel adhesion force of the hot melt adhesive composition to the stainless steel plate is 400 N/m, measured at a temperature of 23° C., a peel angle of 180°, and a tensile speed of 300 mm/min. The above electrical insulating tape is provided.

In the hot melt adhesive composition for the electrical insulating tape of the present invention, as the aromatic vinyl block copolymer, a block copolymer A represented by the following general formula (I) and a block copolymer A represented by the following general formula (II) are used. It is preferable to contain the block copolymer B shown below.
Ar1-D1-Ar2 (I)
Ar3-D2 (II)
(In the above general formulas (I) and (II), Ar1, Ar2 and Ar3 are each an aromatic vinyl polymer block, and D1 and D2 are each a conjugated diene polymer block.)
In the hot melt adhesive composition for the electrical insulating tape of the present invention, the aromatic vinyl monomer unit content of the block copolymer A is higher than the aromatic vinyl monomer unit content of the block copolymer B. More than quantity;
The weight average molecular weight (Mw (Ar1)) of the aromatic vinyl polymer block Ar1 of the block copolymer A and the weight average molecular weight (Mw (Ar3)) of the aromatic vinyl polymer block Ar3 of the block copolymer B. It is preferable that these are substantially the same.
In the electrical insulating tape of the present invention, the weight average molecular weight (Mw(Ar2)) of the aromatic vinyl polymer block Ar2 of the block copolymer A is greater than the weight average molecular weight (Mw(Ar2)) of the aromatic vinyl polymer block Ar1. )) (Mw(Ar2)/Mw(Ar1)) is preferably in the range of 1 to 7.
In the electrical insulating tape of the present invention, it is preferable that the block copolymer B is prepared together with the block copolymer A when the block copolymer A is prepared.

Further, in the hot melt adhesive composition for the electrical insulating tape of the present invention, the hydrogenated hydrocarbon resin is
1,3-pentadiene monomer unit 30% by mass to 75% by mass,
20% by mass to 50% by mass of alicyclic monoolefin monomer units having 4 to 6 carbon atoms,
5% to 25% by mass of acyclic monoolefin monomer units having 4 to 8 carbon atoms,
It is obtained by hydrogenating a hydrocarbon resin containing 0% to 10% by mass of alicyclic diolefin monomer units and 0% to 30% by mass of aromatic monoolefin monomer units. It is preferable.
In the electrical insulating tape of the present invention, the hydrogenated hydrocarbon resin is a hydrocarbon resin in which the content of monomer units consisting of dicyclopentadiene is 10% by mass or less as the hydrocarbon resin before hydrogenation. , is preferably obtained by hydrogenation.
In the hot melt adhesive composition for the electrical insulation tape of the present invention,
The hydrogenated hydrocarbon resin is
The hydrogenation rate of the olefin is 10% to 80%,
In the case of containing an aromatic monomer unit, the hydrogenation rate of the aromatic ring is 1% to 30%,
The weight average molecular weight (Mw) is 1,000 to 3,500,
Z average molecular weight (Mz) is 2,000 to 7,000,
The ratio of Z average molecular weight to weight average molecular weight (Mz/Mw) is 1.5 to 2.5,
The softening point is 50°C or higher,
It is preferable that the Gardner color number of the 50% by mass toluene solution is 3 or less.

Moreover, in the electrical insulating tape of the present invention, it is preferable that the hot melt adhesive composition further contains a softener.
In the electrical insulating tape of the present invention, the content of the aromatic vinyl block copolymer is 10% by mass to 70% by mass, the content of the hydrogenated hydrocarbon resin is 20% by mass to 80% by mass, and the content of the softener is 10% to 70% by mass. The content is preferably 0.1% by mass to 30% by mass.

According to the present invention, it is possible to provide an electrical insulating tape that has low odor, suppresses changes in adhesive strength over time, and has excellent holding power.

The electrical insulating tape of the present invention comprises a hot melt adhesive composition and a base material.

(Hot melt adhesive composition)
The hot melt adhesive composition used in the present invention contains an aromatic vinyl block copolymer and a hydrogenated hydrocarbon resin, and when heated at 65°C for 2 hours, toluene volatilization occurs. Peeling on a stainless steel plate with a quantity of 260 μg/m ³ or less, a total volatile component amount of 15,000 μg/m ³ or less, and measured at a temperature of 23°C, a peeling angle of 180°, and a tensile speed of 300 mm/min. The adhesive force is controlled to be 400 N/m or more.

(Aromatic vinyl block copolymer)
The aromatic vinyl block copolymer used in the present invention is preferably a block copolymer comprising a specific aromatic vinyl polymer block and a conjugated diene polymer block.

In the present invention, as a block copolymer comprising such an aromatic vinyl polymer block and a conjugated diene polymer block, a block copolymer A represented by the following general formula (I) and a block copolymer A represented by the following general formula (II) are used. ) A block copolymer composition containing block copolymer B represented by:
Ar1-D1-Ar2 (I)
Ar3-D2 (II)
(In the above general formulas (I) and (II), Ar1, Ar2 and Ar3 are each an aromatic vinyl polymer block, and D1 and D2 are each a conjugated diene polymer block.)

Block copolymer A is a triblock copolymer having two aromatic vinyl polymer blocks represented by the following general formula (I) and one conjugated diene polymer block.
Ar1-D1-Ar2 (I)
(In the above general formula (I), Ar1 and Ar2 are each an aromatic vinyl polymer block, and D1 is a conjugated diene polymer block.)

The aromatic vinyl polymer block Ar1 constituting the block copolymer A is a polymer block whose main structural unit is an aromatic vinyl monomer unit. The aromatic vinyl monomers used to constitute the aromatic vinyl monomer unit of the aromatic vinyl polymer block Ar1 include styrene; α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene; Alkyl-substituted styrenes such as methylstyrene, 2,4-dimethylstyrene, ethylstyrene, p-tert-butylstyrene; halogen-substituted styrenes such as 4-chlorostyrene, 2-bromostyrene, 3,5-difluorostyrene; 4 Examples include alkoxy-substituted styrenes such as -methoxystyrene and 3,5-dimethoxystyrene. Among these, halogen-free aromatic vinyl monomers are preferred, from the viewpoint of being able to further increase the adhesive strength as an adhesive and from the standpoint of being able to further increase the holding power of electrical insulating tapes. Styrene and alkyl-substituted styrene are more preferred, and styrene is particularly preferred. These aromatic vinyl monomers can be used alone or in combination of two or more.

The aromatic vinyl polymer block Ar1 may contain monomer units other than aromatic vinyl monomer units. Monomers constituting monomer units other than aromatic vinyl monomer units that may be included in the aromatic vinyl polymer block Ar1 include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3 Examples include conjugated diene monomers such as -butadiene and 1,3-pentadiene. The content of monomer units other than aromatic vinyl monomer units in the aromatic vinyl polymer block Ar1 is preferably 20% by mass or less, more preferably 10% by mass or less, and substantially Particularly preferred is 0% by mass. That is, the content of aromatic vinyl monomer units in the aromatic vinyl polymer block Ar1 is preferably 80% by mass or more, more preferably 90% by mass or more, and substantially 100% by mass. It is particularly preferable that there be.

The weight average molecular weight (Mw(Ar1)) of the aromatic vinyl polymer block Ar1 is not particularly limited, but can usually be within the range of 5,000 to 100,000, and may be within the range of 6,000 to 50,000. It is preferably within the range, more preferably within the range of 7,000 to 30,000, and even more preferably within the range of 10,000 to 16,000. By setting Mw (Ar1) within the above range, it is possible to further increase the adhesive strength as an adhesive while suppressing an increase in melt viscosity, and it is also possible to further increase the holding power of the electrical insulating tape. .

Furthermore, the molecular weight distribution (Mw(Ar1)/Mn(Ar1)), which is the ratio of the weight average molecular weight (Mw(Ar1) to the number average molecular weight (Mn(Ar1)), of the aromatic vinyl polymer block Ar1 changes over time. From the viewpoint of being able to further reduce changes in adhesive strength, it is preferably 1.5 or less, more preferably 1.2 or less.

In the present invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of each polymer block, block copolymer, and block copolymer composition are expressed as polystyrene equivalent values measured by high performance liquid chromatography. You can ask for it. More specifically, the weight average molecular weight and number average molecular weight can be determined as polystyrene equivalent molecular weight by high performance liquid chromatography using tetrahydrofuran as a carrier.

The conjugated diene polymer block D1 constituting the block copolymer A is a polymer block whose main structural unit is a conjugated diene monomer unit. The conjugated diene monomer used to constitute the conjugated diene monomer unit of the conjugated diene polymer block D1 is not particularly limited as long as it is a conjugated diene compound, but for example, 1,3-butadiene, isoprene, 2 , 3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene and the like. Among these, as the conjugated diene monomer, a halogen-free conjugated diene monomer is preferable, from the viewpoint of being able to further increase the adhesive strength as an adhesive and to further increase the holding power of electrical insulating tape. From the viewpoint that 1,3-butadiene and/or isoprene are more preferred, and isoprene is particularly preferred. These conjugated diene monomers can be used alone or in combination of two or more. Note that the conjugated diene polymer block D1 constituting the block copolymer A may be one in which a portion of the carbon-carbon unsaturated bonds is subjected to a hydrogenation reaction.

The conjugated diene polymer block D1 may contain monomer units other than conjugated diene monomer units. Examples of monomers constituting monomer units other than the conjugated diene monomer unit that may be contained in the conjugated diene polymer block D1 include aromatic vinyl monomers such as styrene and α-methylstyrene, α,β- Examples include unsaturated nitrile monomers, unsaturated carboxylic acid or acid anhydride monomers, unsaturated carboxylic acid ester monomers, and non-conjugated diene monomers. The content of monomer units other than conjugated diene monomer units in the conjugated diene polymer block D1 is preferably 20% by mass or less, more preferably 10% by mass or less, and substantially 0 mass%. % is particularly preferred. That is, the content of conjugated diene monomer units in the conjugated diene polymer block D1 is preferably 80% by mass or more, more preferably 90% by mass or more, and substantially 100% by mass. is particularly preferred.

The content of monomer units having a vinyl bond in the monomer units constituting the conjugated diene polymer block D1 is not particularly limited, but is usually 50% by mass or less and 20% by mass or less. is preferable, and particularly preferably within the range of 5% by mass to 10% by mass. By setting the content of the monomer unit having a vinyl bond within the above range, the adhesive strength at low temperatures can be further enhanced.

The weight average molecular weight (Mw(D1)) of the conjugated diene polymer block D1 is not particularly limited, but can usually be within the range of 70,000 to 190,000, and may be within the range of 80,000 to 160,000. It is preferably within the range of 85,000 to 140,000, more preferably within the range of 110,000 to 130,000. By setting Mw (D1) within the above range, it is possible to further increase the adhesive strength as an adhesive while suppressing an increase in melt viscosity, and it is also possible to further increase the holding power of the electrical insulating tape. .

In addition, the molecular weight distribution (Mw(D1)/Mn(D1)), which is the ratio between the weight average molecular weight (Mw(D1) and the number average molecular weight (Mn(D1)), of the conjugated diene polymer block D1 is determined by the adhesion over time. From the viewpoint of being able to further reduce the change in force, it is preferably 1.5 or less, more preferably 1.2 or less.

The aromatic vinyl polymer block Ar2 constituting the block copolymer A is a polymer block whose main structural unit is an aromatic vinyl monomer unit. Examples of the aromatic vinyl monomer used to constitute the aromatic vinyl monomer unit of the aromatic vinyl polymer block Ar2 include those similar to those of the aromatic vinyl polymer block Ar1.

Further, the aromatic vinyl polymer block Ar2 may contain monomer units other than the aromatic vinyl monomer units, and the aromatic vinyl polymer block Ar2 may contain monomer units other than the aromatic vinyl monomer units that may be included in the aromatic vinyl polymer block Ar2. Examples of the monomer constituting the monomer unit include those similar to those of the aromatic vinyl polymer block Ar1, and the content thereof can also be the same.

The weight average molecular weight (Mw (Ar2)) of the aromatic vinyl polymer block Ar2 may be larger than the weight average molecular weight (Mw (Ar1)) of the aromatic vinyl polymer block Ar1 constituting the block copolymer A, It may be approximately the same as Mw(Ar1). In the present invention, the ratio (Mw(Ar2)/Mw( Ar1))) is preferably within the range of 1 to 7, more preferably within the range of 1 to 5, even more preferably within the range of 1.2 to 4, particularly 1. A range of 5 to 3 is particularly preferred. By setting the weight average molecular weight ratio within the above range, the adhesive force as an adhesive can be further increased, and the holding power of the electrical insulating tape can be further increased.

The weight average molecular weight (Mw(Ar2)) of the aromatic vinyl polymer block Ar2 is not particularly limited, but can usually be within the range of 5,000 to 120,000, and may be within the range of 9,000 to 100,000. It is preferably within the range, and more preferably within the range of 4,000 to 90,000. By setting Mw (Ar2) within the above range, it is possible to further increase the adhesive force as an adhesive while suppressing the decrease in productivity due to high molecular weight, and also to improve the holding power of electrical insulating tape. It can be increased further.

The molecular weight distribution (Mw(Ar2)/Mn(Ar2)), which is the ratio between the weight average molecular weight (Mw(Ar2) and the number average molecular weight (Mn(Ar2))) of the aromatic vinyl polymer block Ar2, determines the adhesive strength over time. From the viewpoint of being able to further reduce the change in , it is preferably 1.5 or less, and more preferably 1.2 or less.

Block copolymer A is a triblock copolymer consisting of the above-mentioned aromatic vinyl polymer block Ar1, conjugated diene polymer block D1, and aromatic vinyl polymer block Ar2, and its weight average molecular weight (MwA), i.e. The weight average molecular weight of the block copolymer A as a whole can usually be within the range of 80,000 to 400,000, preferably within the range of 90,000 to 300,000, and preferably 100,000. 250,000, more preferably 110,000 to 220,000, particularly preferably 150,000 to 190,000. By setting the weight average molecular weight (MwA) of block copolymer A within the above range, it is possible to further increase the adhesive strength as an adhesive while suppressing an increase in melt viscosity. Holding power can be further increased.

The molecular weight distribution (Mw/Mn) of block copolymer A, that is, the molecular weight distribution of the entire block copolymer A, is 1.5 or less from the viewpoint of making it possible to further reduce changes in adhesive strength over time. It is preferably 1.2 or less, and more preferably 1.2 or less.

The aromatic vinyl monomer unit content of block copolymer A (the ratio of aromatic vinyl monomer units to all monomer units constituting block copolymer A) is usually 15% by mass to Within the range of 75% by mass, preferably within the range of 17% by mass to 60% by mass, more preferably within the range of 18% by mass to 50% by mass, and 20% by mass to 35% by mass. More preferably, it is within the range. By setting the aromatic vinyl monomer unit content within the above range, the adhesive strength as an adhesive can be further increased, and the holding power of the electrical insulating tape can be further increased.

Further, in the present invention, it is preferable that the aromatic vinyl monomer unit content of block copolymer A is greater than the aromatic vinyl monomer unit content of block copolymer B, which will be described later. Specifically, the ratio of the aromatic vinyl monomer unit content of block copolymer A to the aromatic vinyl monomer unit content of block copolymer B (aromatic vinyl monomer unit content of block copolymer A) mer unit content/aromatic vinyl monomer unit content of block copolymer B) is preferably within the range of 1.1 to 5, and preferably within the range of 1.5 to 4. More preferably, it is within the range of 1.75 to 3.5. By setting the above ratio within the above range, the adhesive force as an adhesive can be further increased, and the holding power of the electrical insulating tape can be further increased.

In addition, the content of block copolymer A in the block copolymer composition (the content of block copolymer A in the block copolymer composition containing block copolymer A and block copolymer B) The amount) can usually be within the range of 10% by mass to 90% by mass, preferably within the range of 15% by mass to 60% by mass, and preferably within the range of 20% by mass to 50% by mass. The content is more preferably 35% by mass to 45% by mass. By setting the content of block copolymer A in the block copolymer composition within the above range, the adhesive strength as an adhesive can be further increased, and the holding power of electrical insulating tape can be further increased. be able to.

In addition, in the present invention, the block copolymer A constituting the block copolymer composition may consist of only one type of block copolymer A having a substantially single configuration. However, it may be composed of two or more types of block copolymers A having substantially different structures.

Block copolymer B is a diblock copolymer having one aromatic vinyl polymer block and one conjugated diene polymer block, represented by the following general formula (II).
Ar3-D2 (II)
(In the above general formula (II), Ar3 is an aromatic vinyl polymer block, and D2 is a conjugated diene polymer block.)

The aromatic vinyl polymer block Ar3 constituting the block copolymer B is a polymer block whose main structural unit is an aromatic vinyl monomer unit. The aromatic vinyl monomer used to constitute the aromatic vinyl monomer unit of the aromatic vinyl polymer block Ar3 is the same as that of the aromatic vinyl polymer block Ar1 constituting the block copolymer A. Things can be mentioned.

Further, the aromatic vinyl polymer block Ar3 may contain monomer units other than the aromatic vinyl monomer units, and the aromatic vinyl polymer block Ar3 may contain monomer units other than the aromatic vinyl monomer units that may be included in the aromatic vinyl polymer block Ar3. Examples of the monomer constituting the monomer unit include those similar to those of the aromatic vinyl polymer block Ar1 constituting the block copolymer A, and the content thereof can also be the same.

In the present invention, the type of monomer used to form the monomer unit constituting the aromatic vinyl polymer block Ar3 is the same as that of the aromatic vinyl polymer block Ar1 of the block copolymer A. It is preferable that the type of monomer used to form the monomer unit is the same, and the content ratio of each monomer unit forming the aromatic vinyl polymer block Ar3 is the same as that of the monomer used for forming the monomer unit. It is preferable that the content ratio of each monomer unit constituting the aromatic vinyl polymer block Ar1 of the aggregate A is substantially the same. Since the monomer units constituting the aromatic vinyl polymer block Ar3 and the monomer units constituting the aromatic vinyl polymer block Ar1 of the block copolymer A are substantially the same, the block copolymer It is possible to increase the compatibility between the polymer A and the block copolymer B, thereby further increasing the adhesive strength as an adhesive, and further increasing the holding power of electrical insulating tape. can.

In addition, in the present invention, the aromatic vinyl polymer block Ar3 constituting the block copolymer B has a weight average molecular weight (Mw(Ar3)) equal to that of the aromatic vinyl polymer block constituting the block copolymer A. It is preferable that the weight average molecular weight (Mw(Ar1)) is substantially the same as that of Ar1. In this case, it is sufficient that Mw (Ar3) and Mw (Ar1) are in a relationship that can be determined to be substantially the same, but the ratio of their weight average molecular weights (Mw (Ar3)/Mw (Ar1)) is preferably within the range of 0.95 to 1.05, more preferably within the range of 0.98 to 1.02, and particularly preferably 1.00. Since Mw (Ar3) and Mw (Ar1) are substantially the same, the compatibility between block copolymer A and block copolymer B can be increased, and thereby, the adhesive The adhesive strength of the electrical insulating tape can be further increased, and the holding power of the electrical insulating tape can be further increased.

Furthermore, the molecular weight distribution (Mw(Ar3)/Mn(Ar3)), which is the ratio of the weight average molecular weight (Mw(Ar3) to the number average molecular weight (Mn(Ar3)), of the aromatic vinyl polymer block Ar3 is also From the viewpoint of increasing the compatibility between polymer A and block copolymer B, thereby further increasing the adhesive strength as an adhesive, the aromatic vinyl polymer constituting block copolymer A It is preferable to make the molecular weight distribution substantially the same as the molecular weight distribution (Mw(Ar1)/Mn(Ar1)) of the combined block Ar1. That is, [Mw(Ar3)/Mn(Ar3)]/[Mw(Ar1)/Mn( Ar1)] is preferably within the range of 0.95 to 1.05, more preferably within the range of 0.98 to 1.02, and particularly preferably 1.00.

The conjugated diene polymer block D2 constituting the block copolymer B is a polymer block whose main structural unit is a conjugated diene monomer unit. Examples of the conjugated diene monomer used to constitute the conjugated diene monomer unit of the conjugated diene polymer block D2 include those similar to the conjugated diene polymer block D1 constituting the block copolymer A above. .

Further, the conjugated diene polymer block D2 may contain monomer units other than the conjugated diene monomer units, and the conjugated diene polymer block D2 may contain monomer units other than the conjugated diene monomer units. Examples of the monomers constituting the unit include those similar to the conjugated diene polymer block D1 constituting the block copolymer A, and the content thereof can also be the same.

In the present invention, the type of monomer used to form the monomer unit constituting the conjugated diene polymer block D2 is the same as that of the monomer constituting the conjugated diene polymer block D1 of the block copolymer A. It is preferable that the type of monomer used to form the polymer block D2 is the same as that of the monomer used to form the block copolymer block D2, and the content ratio of each monomer unit forming the conjugated diene polymer block D2 is the same as that of the block copolymer A. It is preferable that the content ratio of each monomer unit constituting the conjugated diene polymer block D1 is substantially the same. Since the monomer units constituting the conjugated diene polymer block D2 and the monomer units constituting the conjugated diene polymer block D1 of the block copolymer A are substantially the same, the block copolymer A The compatibility with the block copolymer B can be improved, and thereby the adhesive force as an adhesive can be further increased, and the holding power of the electrical insulating tape can be further increased.

Further, in the present invention, the conjugated diene polymer block D2 constituting the block copolymer B has a weight average molecular weight (Mw(D2)) that is lower than that of the conjugated diene polymer block D1 constituting the block copolymer A. The weight average molecular weight (Mw(D1)) is preferably substantially the same. In this case, it is sufficient that Mw (D2) and Mw (D1) are in a relationship such that it can be determined that they are substantially the same, but the ratio of their weight average molecular weights (Mw (D2)/Mw (D1)) is preferably within the range of 0.95 to 1.05, more preferably within the range of 0.98 to 1.02, and particularly preferably 1.00. By having Mw (D2) and Mw (D1) substantially the same, the compatibility between block copolymer A and block copolymer B can be increased, and thereby, the adhesive The adhesive strength of the electrical insulating tape can be further increased, and the holding power of the electrical insulating tape can be further increased.

In addition, the molecular weight distribution (Mw(D2)/Mn(D2)), which is the ratio between the weight average molecular weight (Mw(D2) and the number average molecular weight (Mn(D2))) of the conjugated diene polymer block D2, is also From the viewpoint of increasing the compatibility between the coalescing A and the block copolymer B, thereby further increasing the adhesive strength as an adhesive, and further increasing the holding power of electrical insulating tape, the block copolymer It is preferable that the molecular weight distribution (Mw(D1)/Mn(D1)) is substantially the same as the molecular weight distribution (Mw(D1)/Mn(D1)) of the conjugated diene polymer block D1 constituting the copolymer A. That is, [Mw(D2)/Mn(D2) ]/[Mw(D1)/Mn(D1)] is preferably within the range of 0.95 to 1.05, more preferably within the range of 0.98 to 1.02, and 1. 00 is particularly preferred.

Block copolymer B is a diblock copolymer consisting of the above-mentioned aromatic vinyl polymer block Ar3 and conjugated diene polymer block D2, and its weight average molecular weight (MwB), that is, the entire block copolymer B The weight average molecular weight of usually can be within the range of 80,000 to 300,000, preferably within the range of 85,000 to 250,000, and preferably within the range of 90,000 to 230,000. It is more preferably within the range of 95,000 to 200,000, and particularly preferably within the range of 120,000 to 150,000. By setting the weight average molecular weight (MwB) of block copolymer B within the above range, it is possible to further increase the adhesive force as an adhesive while suppressing an increase in melt viscosity. Holding power can be further increased.

The molecular weight distribution (Mw/Mn) of block copolymer B, that is, the molecular weight distribution of the entire block copolymer B, is 1.5 or less from the viewpoint of making it possible to further reduce changes in adhesive strength over time. It is preferably 1.2 or less, and more preferably 1.2 or less.

The aromatic vinyl monomer unit content of block copolymer B (the ratio of aromatic vinyl monomer units to all monomer units constituting block copolymer B) is usually 8% by mass to Within the range of 50% by mass, preferably within the range of 10% by mass to 40% by mass, more preferably within the range of 12% by mass to 30% by mass, and within the range of 12% by mass to 17% by mass. It is even more preferable that there be. By setting the aromatic vinyl monomer unit content within the above range, the adhesive strength as an adhesive can be further increased, and the holding power of the electrical insulating tape can be further increased.

In addition, in the present invention, the block copolymer B constituting the block copolymer composition may consist of only one type of block copolymer B having a substantially single configuration. However, it may be composed of two or more types of block copolymers B having substantially different structures.

Moreover, in the present invention, it is preferable that block copolymer B is prepared together with block copolymer A when preparing block copolymer A. Specifically, as will be described in detail in the manufacturing method described below, first, block copolymer B is obtained, and then a portion of the obtained block copolymer B is further treated with aromatic vinyl polymer block Ar2. It is preferable that block copolymer B and block copolymer A be prepared simultaneously by a method in which block copolymer A is obtained by combining .

In the present invention, it is preferable to use a block copolymer composition containing the above-mentioned block copolymer A and block copolymer B as the aromatic vinyl block copolymer, but in this case, , may consist only of block copolymer A and block copolymer B, but may also contain a block copolymer other than block copolymer A and block copolymer B. Examples of such block copolymers include aromatic vinyl-conjugated diene-aromatic vinyl triblock copolymers and radial aromatic vinyl-conjugated diene block copolymers having a structure different from block copolymer A. These include, but are not limited to. In the block copolymer component, the amount occupied by block copolymers other than block copolymer A and block copolymer B is preferably 20% by mass or less, more preferably 10% by mass or less.

In a block copolymer component consisting of a block copolymer A, a block copolymer B, and a block copolymer other than the block copolymer A and the block copolymer B that may be contained in the block copolymer component, the block copolymer component The ratio of aromatic vinyl monomer units to the total (in the following description, it may be referred to as "total aromatic vinyl monomer unit content") increases the adhesive strength of the adhesive. In addition, from the viewpoint of further increasing the holding power of the electrical insulating tape, it is preferably within the range of 10% by mass to 50% by mass, and preferably within the range of 13% by mass to 40% by mass. It is more preferably within the range of 15% by mass to 37% by mass, and particularly preferably within the range of 17% by mass to 35% by mass.

This total aromatic vinyl monomer unit content is determined by taking into account the aromatic vinyl monomer unit content of each block copolymer constituting the block copolymer composition, and determining the blending amount of each block copolymer. It can be easily adjusted by adjusting . In addition, if all the polymer components constituting the block copolymer composition are composed only of aromatic vinyl monomer units and conjugated diene monomer units, Rubber Chem. Technol. , 45, 1295 (1972), the block copolymer is ozonolyzed and then reduced with lithium aluminum hydride to decompose the conjugated diene monomer units and produce aromatic vinyl monomers. Since only the unit portion can be taken out, the total aromatic vinyl monomer unit content can be easily measured.

The weight average molecular weight (Mw) of the aromatic vinyl block copolymer as a whole used in the present invention, that is, the block copolymer composition containing the above-mentioned block copolymer A and block copolymer B is used. In the case, the weight average of the entire block copolymer component consisting of block copolymer A, block copolymer B, and block copolymers other than block copolymer A and block copolymer B that may be contained as the case may be. The molecular weight is preferably within the range of 80,000 to 400,000, more preferably within the range of 85,000 to 280,000, and preferably within the range of 90,000 to 250,000. More preferred.

The method for producing the block copolymer composition containing the above-described block copolymer A and block copolymer B is not particularly limited. For example, it can be manufactured by separately manufacturing each block copolymer according to a conventional polymerization method, and then mixing them according to a conventional method such as kneading or solution mixing.

In the present invention, the compatibility between block copolymer A and block copolymer B is further increased, thereby further increasing the adhesive strength as an adhesive and the holding power of electrical insulating tape. From the viewpoint that it is possible to obtain the following production method, specifically, first, block copolymer B is obtained, and then a part of the obtained block copolymer B is further processed with aromatic vinyl. A preferred method is to obtain block copolymer A by combining polymer blocks Ar2.

More specifically, it is preferable to manufacture using a manufacturing method consisting of the following steps (1) to (5).
(1): Step of polymerizing an aromatic vinyl monomer using a polymerization initiator in a solvent (2): Solution containing an aromatic vinyl polymer having an active end obtained in step (1) above Step (3) of adding a conjugated diene monomer: Adding a polymerization terminator to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained in step (2) above. Step (4) of adding less than 1 molar equivalent to the active end of the aromatic vinyl-conjugated diene block copolymer having an end to form block copolymer B: in the step (3) above. Step (5) of adding an aromatic vinyl monomer to the resulting solution to form block copolymer A: Step of recovering the polymer component from the solution obtained in step (4) above.

In the above manufacturing method, first, an aromatic vinyl monomer is polymerized using a polymerization initiator in a solvent (step (1)). As the polymerization initiator used, organic alkali metal compounds, organic alkaline earth metal compounds, which are generally known to have anionic polymerization activity toward aromatic vinyl monomers and conjugated diene monomers, Organic lanthanide series rare earth metal compounds and the like can be used. As the organic alkali metal compound, an organic lithium compound having one or more lithium atoms in the molecule is particularly preferably used, and specific examples thereof include ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, Organic monolithium compounds such as sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium, stilbene lithium, dialkylaminolithium, diphenylaminolithium, ditrimethylsilylaminolithium, methylene dilithium, tetramethylene dilithium, hexamethylene Examples include organic dilithium compounds such as dilithium, isoprenyldilithium, and 1,4-dilithio-ethylcyclohexane, and organic trilithium compounds such as 1,3,5-trilithiobenzene. Among these, organic monolithium compounds are particularly preferably used.

Examples of the organic alkaline earth metal compound used as a polymerization initiator include n-butylmagnesium bromide, n-hexylmagnesium bromide, ethoxycalcium, calcium stearate, t-butoxystrontium, ethoxybarium, isopropoxybarium, ethylmercaptobarium, Examples include t-butoxybarium, phenoxybarium, diethylaminobarium, barium stearate, and ethylbarium. Specific examples of other polymerization initiators include composite catalysts consisting of lanthanoid rare earth metal compounds containing neodymium, samarinium, gadolinium, etc./alkyl aluminum/alkyl aluminum halide/alkyl aluminum hydride, titanium, vanadium, samarinium, gadolinium, etc. Examples include those that form a homogeneous system in an organic solvent and have living polymerizability, such as metallocene-type catalysts containing the following. In addition, these polymerization initiators may be used individually, and may be used as a mixture of 2 or more types.

The amount of the polymerization initiator used may be determined depending on the molecular weight of each target block copolymer, and is not particularly limited, but is usually 0.01 mmol to 20 mmol per 100 g of the total monomers used. Preferably, the amount is from 0.05 mmol to 15 mmol, more preferably from 0.1 mmol to 10 mmol.

The solvent used for polymerization is not particularly limited as long as it is inert to the polymerization initiator, and for example, a chain hydrocarbon solvent, a cyclic hydrocarbon solvent, or a mixed solvent thereof is used. Chain hydrocarbon solvents include n-butane, isobutane, 1-butene, isobutylene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene, n-pentane. Examples include linear alkanes and alkenes having 4 to 6 carbon atoms, such as , isopentane, neo-pentane, and n-hexane. Specific examples of the cyclic hydrocarbon solvent include aromatic compounds such as benzene, toluene, and xylene; and alicyclic hydrocarbon compounds such as cyclopentane and cyclohexane. These solvents may be used alone or in combination of two or more.

The amount of the solvent used in the polymerization is not particularly limited, but the concentration of the total block copolymer in the solution after the polymerization reaction is usually 5% by mass to 60% by mass, preferably 10% by mass to 55% by mass, more preferably is set to be 20% by mass to 50% by mass.

In order to control the structure of each polymer block of each block copolymer, a Lewis base compound may be added to the reactor used for polymerization. Examples of the Lewis base compound include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; Examples include tertiary amines; alkali metal alkoxides such as potassium-t-amyl oxide and potassium-t-butyl oxide; and phosphines such as triphenylphosphine. These Lewis base compounds may be used alone or in combination of two or more, and are appropriately selected within a range that does not impair the object of the present invention.

Further, the timing of adding the Lewis base compound during the polymerization reaction is not particularly limited, and may be appropriately determined depending on the structure of each intended block copolymer. For example, it may be added in advance before starting polymerization, it may be added after some polymer blocks have been polymerized, or it may be added in advance before starting polymerization and then some of the polymer blocks may be added before starting polymerization. Further additions may be made after the polymer block has been polymerized.

The polymerization reaction temperature is usually 10°C to 150°C, preferably 30°C to 130°C, more preferably 40°C to 90°C. The time required for polymerization varies depending on the conditions, but is usually within 48 hours, preferably 0.5 to 10 hours. The polymerization pressure is not particularly limited as long as it is within a pressure range sufficient to maintain the monomer and solvent in a liquid phase within the above polymerization temperature range.

By polymerizing an aromatic vinyl monomer using a polymerization initiator in a solvent under the above conditions, a solution containing an aromatic vinyl polymer having an active end can be obtained. This aromatic vinyl polymer having an active terminal constitutes the aromatic vinyl polymer block Ar1 of the block copolymer A and the aromatic vinyl polymer block Ar3 of the block copolymer B. Therefore, the amount of aromatic vinyl monomer used in this case is determined depending on the desired weight average molecular weight of these polymer blocks.

The next step is a step of adding a conjugated diene monomer to the solution containing the aromatic vinyl polymer having an active end obtained as described above (step (2)). By adding this conjugated diene monomer, a conjugated diene polymer chain is formed from the active end, and a solution containing an aromatic vinyl-conjugated diene block copolymer having an active end is obtained. The amount of the conjugated diene monomer used in this case is determined so that the obtained conjugated diene polymer chain has the conjugated diene polymer block D1 of the target block copolymer A and the conjugated diene polymer block D2 of the block copolymer B. It is determined to have a weight average molecular weight.

In the next step, a polymerization terminator is added to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end obtained as described above. It is added in an amount of less than 1 molar equivalent to the active end of the conjugate (step (3)). When a polymerization terminator is added to a solution containing an aromatic vinyl-conjugated diene block copolymer having an active end, the active end of the aromatic vinyl-conjugated diene block copolymer having an active end is deactivated. , block copolymer B, which is an aromatic vinyl-conjugated diene diblock copolymer, is formed.

The polymerization terminator added in this step is not particularly limited, and conventionally known polymerization terminators can be used without particular limitations. Particularly preferably used polymerization terminators include alcohols such as methanol, ethanol, propanol, butanol, and isopropanol.

The amount of the polymerization terminator added in this step is an amount that is less than 1 molar equivalent with respect to the active end of the aromatic vinyl-conjugated diene block copolymer having an active end. In order to perform the next step of forming block copolymer A, the aromatic vinyl-conjugated diene block copolymer having an active end can remain in the solution. The amount of the polymerization terminator is preferably from 0.10 molar equivalent to 0.90 molar equivalent, more preferably from 0.15 molar equivalent to 0.70 molar equivalent, relative to the active end of the polymer. The amount of polymerization terminator added in this step determines the amount of block copolymer B, so the amount of polymerization terminator added depends on the composition of the target block copolymer component. All you have to do is decide.

The reaction conditions for the polymerization termination reaction are not particularly limited, and may generally be set within the same range as the above-mentioned polymerization reaction conditions.

In the next step, an aromatic vinyl monomer is added to the solution obtained as described above (step (4)). When an aromatic vinyl monomer is added to the solution, an aromatic vinyl polymer chain is formed from the end of the aromatic vinyl-conjugated diene block copolymer with the active end remaining without reacting with the polymerization terminator. . This aromatic vinyl polymer chain constitutes the aromatic vinyl polymer block Ar2 of the block copolymer A. Therefore, the amount of the aromatic vinyl monomer used at this time is determined depending on the target weight average molecular weight of the aromatic vinyl polymer block Ar2. Through this step of adding the aromatic vinyl monomer, an aromatic vinyl-conjugated diene-aromatic vinyl triblock copolymer that will constitute block copolymer A is formed, and as a result, the block copolymer A solution containing polymer A and block copolymer B is obtained. Note that before this step of adding the aromatic vinyl monomer, the conjugated diene monomer was added to the solution containing the aromatic vinyl-conjugated diene block copolymer having an active end that did not react with the polymerization terminator. May be added. When the conjugated diene monomer is added in this manner, the weight average molecular weight of the conjugated diene polymer block D1 of the block copolymer A can be increased compared to the case where the conjugated diene monomer is not added.

In the next step, the desired polymer component is recovered from the solution obtained as described above (step (5)). The method of recovery may be any conventional method and is not particularly limited. For example, after the completion of the reaction, a polymerization terminator such as water, methanol, ethanol, propanol, hydrochloric acid, citric acid, etc. may be added as necessary, and further additives such as an antioxidant may be added as necessary. , can be recovered by applying known methods such as direct drying or steam stripping to the solution. When the polymer component is recovered as a slurry by applying steam stripping or the like, it is dehydrated using any dehydrator such as an extruder type squeezer to form a crumb having a moisture content below a predetermined value, and then The crumb may be dried using any dryer such as a band dryer or an expansion extrusion dryer.

In the manner described above, a block copolymer composition containing the above-described block copolymer A and block copolymer B can be obtained.

Further, in the present invention, the aromatic vinyl block copolymer contains a block copolymer B represented by the above general formula (II) and a block copolymer C represented by the following general formula (III). Block copolymer compositions may also be used.
(Ar4-D3) _n -X (III)
(In the above general formula (III), Ar4 is an aromatic vinyl polymer block, D3 is a conjugated diene polymer block, X is a single bond or a residue of a coupling agent, and n is 2 or more ).

The aromatic vinyl polymer block Ar4 constituting the block copolymer C is a polymer block whose main structural unit is an aromatic vinyl monomer unit. The aromatic vinyl monomer used to constitute the aromatic vinyl monomer unit of the aromatic vinyl polymer block Ar4 is the same as that of the aromatic vinyl polymer block Ar1 constituting the block copolymer A. Things can be mentioned.

Further, the aromatic vinyl polymer block Ar4 may contain monomer units other than the aromatic vinyl monomer units, and the aromatic vinyl polymer block Ar4 may contain monomer units other than the aromatic vinyl monomer units that may be included in the aromatic vinyl polymer block Ar4. Examples of the monomer constituting the monomer unit include those similar to those of the aromatic vinyl polymer block Ar1 constituting the block copolymer A, and the content thereof can also be the same.

Although the weight average molecular weight (Mw(Ar4)) of the aromatic vinyl polymer block Ar4 constituting the block copolymer C is not particularly limited, the aromatic vinyl polymer block Ar1 constituting the block copolymer A It can be adjusted as appropriate within the same range as the weight average molecular weight (Mw(Ar1)).

The conjugated diene polymer block D3 constituting the block copolymer C is a polymer block whose main structural unit is a conjugated diene monomer unit. Examples of the conjugated diene monomer used to constitute the conjugated diene monomer unit of the conjugated diene polymer block D3 include those similar to the conjugated diene polymer block D1 constituting the block copolymer A above. .

Moreover, the conjugated diene polymer block D3 may contain monomer units other than the conjugated diene monomer units, and the conjugated diene polymer block D3 may contain monomer units other than the conjugated diene monomer units. Examples of the monomers constituting the unit include those similar to the conjugated diene polymer block D1 constituting the block copolymer A, and the content thereof can also be the same.

The weight average molecular weight (Mw(D3)) of the conjugated diene polymer block D3 constituting the block copolymer C is not particularly limited, but is the weight of the conjugated diene polymer block D1 constituting the block copolymer A. It can be adjusted as appropriate within the same range as the average molecular weight (Mw(D1)).

Although the method for producing a block copolymer composition containing block copolymer B and block copolymer C is not particularly limited, for example, a method containing the above-mentioned block copolymer A and block copolymer B may be used. In the method for producing a block copolymer composition, in step (3), a coupling agent may be used in place of a part of the polymerization terminator.

The coupling agent is not particularly limited, and any coupling agent having two or more functionalities can be used. Examples of the bifunctional coupling agent include bifunctional halogenated silanes such as dichlorosilane, monomethyldichlorosilane, and dimethyldichlorosilane; bifunctional alkoxysilanes such as diphenyldimethoxysilane and diphenyldiethoxysilane; dichloroethane and dibromoethane. , methylene chloride, dibromomethane; difunctional tin halides such as dichlorotin, monomethyldichlorotin, dimethyldichlorotin, monoethyldichlorotin, diethyldichlorotin, monobutyldichlorotin, dibutyldichlorotin; ; dibromobenzene, benzoic acid, CO, 2-chloropropene and the like. Examples of trifunctional coupling agents include trifunctional halogenated alkanes such as trichloroethane and trichloropropane; trifunctional halogenated silanes such as methyltrichlorosilane and ethyltrichlorosilane; methyltrimethoxysilane, phenyltrimethoxysilane, Examples include trifunctional alkoxysilanes such as phenyltriethoxysilane. Examples of the tetrafunctional coupling agent include tetrafunctional halogenated alkanes such as carbon tetrachloride, carbon tetrabromide, and tetrachloroethane; tetrafunctional halogenated silanes such as tetrachlorosilane and tetrabromosilane; tetramethoxysilane; Examples include tetrafunctional alkoxysilanes such as tetraethoxysilane; tetrafunctional tin halides such as tetrachlorotin and tetrabromostin; and the like. Examples of the coupling agent having five or more functional groups include 1,1,1,2,2-pentachloroethane, perchloroethane, pentachlorobenzene, perchlorobenzene, octabromodiphenyl ether, decabromodiphenyl ether, and the like. These coupling agents may be used alone or in combination of two or more.

In addition, in step (3), in addition to block copolymer B and block copolymer C, the block represented by the above general formula (I) is added by using a polymerization terminator together with a coupling agent. It may further contain copolymer A. Alternatively, the block copolymer A may be further contained by mixing it with a block copolymer composition containing the block copolymer A represented by the above general formula (I).

(Hydrogenated hydrocarbon resin)
The hot melt adhesive composition used in the present invention contains the above-mentioned aromatic vinyl block copolymer and a hydrogenated hydrocarbon resin.

The hydrogenated hydrocarbon resin used in the present invention includes 30% to 75% by mass of 1,3-pentadiene monomer units and an alicyclic monoolefin monomer having 4 to 6 carbon atoms as a hydrocarbon resin before hydrogenation. body units 20% to 50% by mass, acyclic monoolefin monomer units having 4 to 8 carbon atoms 5% to 25% by mass, alicyclic diolefin monomer units 0% to 10% by mass, It is preferable to use one containing 0 to 30 mass % of aromatic monoolefin monomer units and hydrogenate it.

The content of 1,3-pentadiene monomer units in the hydrocarbon resin before hydrogenation is within the range of 30% by mass to 75% by mass, and within the range of 25% by mass to 65% by mass. is preferably within the range of 30% by mass to 60% by mass, even more preferably within the range of 35% by mass to 55% by mass, and even more preferably within the range of 43% by mass to 53% by mass. is particularly preferred. By setting the content of the 1,3-pentadiene monomer unit within the above range, it is possible to further reduce odor while keeping the holding power of the electrical insulating tape high and effectively suppressing changes in adhesive strength over time. I can do it.

A cycloaliphatic monoolefin having 4 to 6 carbon atoms is a hydrocarbon compound having 4 to 6 carbon atoms and having one ethylenically unsaturated bond and a non-aromatic ring structure in its molecular structure. Specific examples of alicyclic monoolefins having 4 to 6 carbon atoms include cyclobutene, cyclopentene, cyclohexene, methylcyclobutene, and methylcyclopentene.

The content of alicyclic monoolefin monomer units having 4 to 6 carbon atoms in the hydrocarbon resin before hydrogenation is within the range of 20% to 50% by mass, and 20% to 45% by mass. It is preferably within the range of , and more preferably within the range of 25% by mass to 40% by mass. By setting the content of the alicyclic monoolefin monomer unit having 4 to 6 carbon atoms within the above range, the electrical insulating tape can maintain a high holding power while effectively suppressing changes in adhesive strength over time. Odor can be further reduced.

In addition, the alicyclic monoolefin having 4 to 6 carbon atoms can be used alone or in combination of two or more types, and when using two or more types in combination, the proportion of each compound can be any proportion. Although not particularly limited, it is preferable that at least cyclopentene is included, and it is more preferable that the proportion of cyclopentene in the alicyclic monoolefin having 4 to 6 carbon atoms is 50% by mass or more.

Acyclic monoolefins having 4 to 8 carbon atoms are chain hydrocarbon compounds having 4 to 8 carbon atoms that have one ethylenically unsaturated bond in their molecular structure and have no ring structure. Specific examples of acyclic monoolefins having 4 to 8 carbon atoms include butenes such as 1-butene, 2-butene, and isobutylene (2-methylpropene); 1-pentene, 2-pentene, and 2-methyl-1; - Pentenes such as butene, 3-methyl-1-butene, 2-methyl-2-butene; Hexenes such as 1-hexene, 2-hexene, 2-methyl-1-pentene; 1-heptene, 2-heptene , 2-methyl-1-hexene; 1-octene, 2-octene, 2-methyl-1-heptene, diisobutylene (2,4,4-trimethyl-1-pentene, 2,4,4- and octenes such as trimethyl-1-pentene).

The content of acyclic monoolefin monomer units having 4 to 8 carbon atoms in the hydrocarbon resin before hydrogenation is within the range of 5% to 25% by mass, and 6% to 25% by mass. It is preferably within the range of , more preferably within the range of 7% by mass to 25% by mass, and even more preferably within the range of 7% by mass to 12% by mass. By setting the content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms within the above range, the electrical insulating tape can maintain a high holding power while effectively suppressing changes in adhesive strength over time. Odor can be further reduced.

In addition, the acyclic monoolefin having 4 to 8 carbon atoms can be used alone or in combination of two or more types, and when using two or more types in combination, the proportion of each compound can be any proportion. Although not particularly limited, it is preferable that at least one member selected from the group consisting of 2-methyl-2-butene, isobutylene, and diisobutylene is contained in the acyclic monoolefin having 4 to 8 carbon atoms. More preferably, the total amount of 2-methyl-2-butene, isobutylene and diisobutylene is 50% by mass or more.

Moreover, the hydrocarbon resin before hydrogenation used in the present invention may contain an alicyclic diolefin. Alicyclic diolefins are hydrocarbon compounds having two or more ethylenically unsaturated bonds and a non-aromatic ring structure in their molecular structure. Specific examples of alicyclic diolefins include cyclopentadiene, cyclopentadiene multimers such as dicyclopentadiene, methylcyclopentadiene, methylcyclopentadiene multimers, and the like.

The content of alicyclic diolefin monomer units in the hydrocarbon resin before hydrogenation is within the range of 0% by mass to 10% by mass, and within the range of 0.5% by mass to 4% by mass. It is preferably within the range of 0.7% by mass to 3% by mass, and even more preferably within the range of 0.8% by mass to 2.6% by mass. By setting the content of the alicyclic diolefin monomer unit within the above range, odor can be further reduced while maintaining a high holding power of the electrical insulating tape and effectively suppressing changes in adhesive strength over time. I can do it.

Furthermore, the hydrocarbon resin before hydrogenation used in the present invention may contain an aromatic monoolefin. Aromatic monoolefins are aromatic compounds that have one ethylenically unsaturated bond in their molecular structure. Specific examples of aromatic monoolefins include styrene, α-methylstyrene, vinyltoluene, indene, and coumaron.

The content of aromatic monoolefin monomer units in the hydrocarbon resin before hydrogenation is within the range of 0% by mass to 30% by mass, and preferably within the range of 0% by mass to 28% by mass. It is preferably within the range of 0% by mass to 26% by mass, and even more preferably within the range of 0% by mass to 18% by mass. By setting the content of the aromatic monoolefin monomer unit within the above range, it is possible to maintain a high holding power of the electrical insulating tape, effectively suppress changes in adhesive strength over time, and further reduce odor. can.

In addition, the hydrocarbon resin before hydrogenation includes 1,3-pentadiene monomer units, alicyclic monoolefin monomer units having 4 to 6 carbon atoms, and acyclic monoolefin monomer units having 4 to 8 carbon atoms. In addition to the mer units, the alicyclic diolefin monomer units, and the aromatic monoolefin monomer units, other monomer units may be included within the range that does not impair the effects of the present invention.

Other monomers used to constitute such other monomer units are not particularly limited as long as they are compounds having addition polymerizability that can be addition-copolymerized with 1,3-pentadiene and the like. Examples of such other monomers include monomers with 4 carbon atoms other than 1,3-pentadiene, such as 1,3-butadiene, 1,2-butadiene, isoprene, 1,3-hexadiene, and 1,4-pentadiene. -6 unsaturated hydrocarbons; alicyclic monoolefins having 7 or more carbon atoms such as cycloheptene; acyclic monoolefins having 4 to 8 carbon atoms such as ethylene, propylene, nonene, etc.

The content of other monomer units in the hydrocarbon resin before hydrogenation is usually in the range of 0% to 30% by mass, and may be in the range of 0% to 25% by mass. It is preferably in the range of 0% by mass to 20% by mass.

The method for producing the hydrocarbon resin before hydrogenation is not particularly limited, but includes, for example, a method of addition polymerizing a monomer mixture containing the monomers forming the monomer units described above. , addition polymerization using a Friedel-Crafts type cationic polymerization catalyst is preferred.

A method of addition polymerization using a Friedel-Crafts type cationic polymerization catalyst includes, for example, aluminum halide (A) and a halogenated hydrocarbon (B1) in which a halogen atom is bonded to a tertiary carbon atom, as described below. and a halogenated hydrocarbon (B) selected from the group consisting of a halogenated hydrocarbon (B2) in which a halogen atom is bonded to a carbon atom adjacent to a carbon-carbon unsaturated bond, and a monomer mixture is added. Examples include a method of polymerization.

Specific examples of aluminum halide (A) include aluminum chloride (AlCl ₃ ), aluminum bromide (AlBr ₃ ), and the like. Among these, aluminum chloride is preferably used from the viewpoint of versatility. The amount of aluminum halide (A) used is not particularly limited, but is preferably 0.05 parts by mass to 10 parts by mass, more preferably 0.1 parts by mass to 5 parts by mass, based on 100 parts by mass of the monomer mixture. It is.

A halogenated hydrocarbon selected from the group consisting of a halogenated hydrocarbon (B1) in which a halogen atom is bonded to a tertiary carbon atom and a halogenated hydrocarbon (B2) in which a halogen atom is bonded to a carbon atom adjacent to a carbon-carbon unsaturated bond. The hydrocarbon (B) has the effect of further increasing the activity of the polymerization catalyst when used together with the aluminum halide (A).

Specific examples of the halogenated hydrocarbon (B1) in which a halogen atom is bonded to a tertiary carbon atom include t-butyl chloride, t-butyl bromide, 2-chloro-2-methylbutane, triphenylmethyl chloride, and the like. Among these, t-butyl chloride is preferred because it has an excellent balance between activity and ease of handling.

Examples of unsaturated bonds in halogenated hydrocarbons (B2) in which a halogen atom is bonded to a carbon atom adjacent to a carbon-carbon unsaturated bond include a carbon-carbon double bond and a carbon-carbon triple bond. This also includes carbon-carbon conjugated double bonds in, for example, carbon-carbon conjugated double bonds. Specific examples of such compounds include benzyl chloride, benzyl bromide, (1-chloroethyl)benzene, allyl chloride, 3-chloro-1-propyne, 3-chloro-1-butene, 3-chloro-1-butyne, Examples include cinnabar chloride. Among these, benzyl chloride is preferred because it has an excellent balance between activity and ease of handling.

The halogenated hydrocarbon (B) may be used alone or in combination of two or more. The amount of halogenated hydrocarbon (B) to be used is preferably in the range of 0.05 to 50, more preferably in the range of 0.1 to 10, in terms of molar ratio to aluminum halide (A).

When performing a polymerization reaction, the order in which the monomer mixture and the polymerization catalyst are added to the polymerization reactor is not particularly limited, and may be added in any order, but from the viewpoint of well controlling the polymerization reaction. A part of the monomer components constituting the monomer mixture and aluminum halide (A) are added to a polymerization reactor in advance, and a part of the monomer components constituting the monomer mixture, After contacting the aluminum halide (A) in advance, it is preferable to add the remainder of the monomer components constituting the monomer mixture to the polymerization reactor to start the polymerization reaction. In this case, at least an alicyclic monoolefin having 4 to 6 carbon atoms is used as a part of the monomer components constituting the monomer mixture, and it is added in advance to the polymerization reactor together with aluminum halide (A). After the alicyclic monoolefin having 4 to 6 carbon atoms and aluminum halide (A) are brought into contact with each other in advance to obtain a mixture thereof, the remainder of the monomer components constituting the monomer mixture is removed. More preferably, it is added to a polymerization reactor to start the polymerization reaction.

The amount of the alicyclic monoolefin having 4 to 6 carbon atoms to be brought into contact with the aluminum halide (A) in advance is preferably at least 5 times (mass ratio) the amount of the aluminum halide (A), 6 alicyclic monoolefin:aluminum halide (A)", preferably in the range of 5:1 to 120:1, more preferably in the range of 10:1 to 100:1, even more preferably 15: It ranges from 1 to 80:1. By setting the mass ratio within the above range, the catalytic activity can be further enhanced.

When the aluminum halide (A) and the alicyclic monoolefin having 4 to 6 carbon atoms are brought into contact with each other in advance, the order in which they are added is not particularly limited, and the halogenated alicyclic monoolefin having 4 to 6 carbon atoms is Aluminum (A) may be added, or conversely, an alicyclic monoolefin having 4 to 6 carbon atoms may be added to aluminum halide (A). Since mixing is usually accompanied by heat generation, a suitable diluent may also be used. As the diluent, the solvent described below can be used.

After preparing a mixture by bringing aluminum halide (A) into contact with an alicyclic monoolefin having 4 to 6 carbon atoms in advance as described above, the remainder of the monomer components constituting the monomer mixture is removed. Added. Further, it is preferable to further mix the halogenated hydrocarbon (B) with the remainder of the monomer components constituting the monomer mixture, and the order in which these are added is not particularly limited.

From the viewpoint of better controlling the polymerization reaction, it is preferable to add a solvent to the polymerization reaction system and perform the polymerization reaction. The type of solvent is not particularly limited as long as it does not inhibit the polymerization reaction, but saturated aliphatic hydrocarbons or aromatic hydrocarbons are preferred. Examples of the saturated aliphatic hydrocarbon used as a solvent include n-pentane, n-hexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, 3-methylhexane, 3-ethylpentane. , 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 2,2,3-trimethylbutane, 2,2,4-trimethylpentane, etc. Chain saturated aliphatic hydrocarbons having 5 to 10 carbon atoms; cyclic saturated aliphatic hydrocarbons having 5 to 10 carbon atoms such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane. Examples of the aromatic hydrocarbon used as a solvent include aromatic hydrocarbons having 6 to 10 carbon atoms such as benzene, toluene, and xylene. One kind of solvent may be used alone, or two or more kinds of solvents may be used as a mixed solvent. The amount of the solvent used is not particularly limited, but it is preferably within the range of 10 parts by mass to 1,000 parts by mass, and within the range of 50 parts by mass to 500 parts by mass, based on 100 parts by mass of the monomer mixture. It is more preferable that Note that, for example, by adding a mixture of an addition polymerizable component and a non-addition polymerizable component, such as a mixture of cyclopentane and cyclopentene derived from a C5 fraction, to the polymerization reaction system, the addition polymerizable component has a monomer content. The non-addition polymerizable component may be used as a solvent.

The polymerization temperature during the polymerization reaction is not particularly limited, but is preferably within the range of -20°C to 100°C, and preferably within the range of 10°C to 70°C. If the polymerization temperature is too low, the polymerization activity may decrease and productivity may be poor, and if the polymerization temperature is too high, the obtained pre-modified resin may have a poor hue. The pressure during the polymerization reaction may be either atmospheric pressure or increased pressure. The polymerization reaction time can be selected as appropriate, but is usually selected in the range of 10 minutes to 12 hours, preferably 30 minutes to 6 hours.

The polymerization reaction can be stopped by adding a polymerization terminator such as methanol, aqueous sodium hydroxide solution, or aqueous ammonia solution to the polymerization reaction system when the desired polymerization conversion rate is obtained.

Moreover, in the method for producing a hydrocarbon resin before hydrogenation, in addition to the above polymerization step, other steps may be included as necessary. Other processes include, for example, catalyst residue removal in which solvent-insoluble catalyst residues, which are generated when the polymerization catalyst is inactivated by adding a polymerization terminator in the polymerization process, are removed by filtration or the like after the polymerization process. After stopping the polymerization reaction in the polymerization process, unreacted monomers and solvents are removed, low molecular weight oligomer components are removed by steam distillation, etc., and the hydrocarbon resin before hydrogenation is removed by cooling. Examples include a recovery step in which the solid state is obtained.

In addition, as another step, after the catalyst residue removal step and before the recovery step, the catalyst residue removal mixture after removing the catalyst residue insoluble in the solvent is brought into contact with an adsorbent to obtain an adsorbent-treated mixture. Processing steps may also be employed. By including the contact treatment step, odor can be further reduced when an electrical insulating tape is produced.

The adsorbent used in the contact treatment step is not particularly limited, and may be a chemical adsorbent or a physical adsorbent. Chemical adsorbents include zinc-based adsorbents such as basic zinc carbonate, zinc oxide, zinc sulfate, zinc laurate, zinc stearate, and zinc myristate, and zirconium-based adsorbents such as zirconium oxide, zirconium hydroxide, and zirconium phosphate. Examples include manganese-based adsorbents such as manganese dioxide, cobalt-based adsorbents such as cobalt chloride, copper-based adsorbents such as copper chloride and copper oxide, and amine-based adsorbents such as polyamine compounds.

Examples of physical adsorbents include zeolite-based adsorbents that are collectively referred to as a group of hydrous aluminosilicate minerals such as sodium aluminum silicate, silicon dioxide, magnesium oxide, silica gel, silica/alumina, aluminum silicate, activated alumina, acid clay, and activated clay. , dawsonite compounds, hydrotalcite compounds, and the like.

One type of adsorbent may be used alone, or two or more types may be used in combination. In addition, when using two or more types of adsorbents together, two or more types of chemical adsorbents may be used together, two or more types of physical adsorbents may be used together, or one or more types of chemical adsorbents may be used together. The agent and one or more types of physical adsorbents may be used in combination, for example, a chemical adsorbent may be supported on the physical adsorbent. From the viewpoint of further reducing odor when used as an electrical insulating tape, it is preferable to use a chemical adsorbent, more preferably a zinc-based adsorbent, and particularly preferably to use basic zinc carbonate.

The method of bringing the catalyst residue removal mixture into contact with the adsorbent in the contact treatment step is not particularly limited. For example, there is a batch processing method in which a catalyst residue removal mixture and an adsorbent are made to coexist in an appropriately selected container and brought into contact with each other with stirring as necessary, or a method in which the adsorbent is filled in a packed column in advance and Another example is a continuous treatment method in which the catalyst residue removal mixture is brought into contact with the catalyst by flowing it through the flow.

The amount of adsorbent used when the catalyst residue removal mixture and adsorbent are brought into contact with each other in a batch treatment method is not particularly limited, but is based on 100 parts by mass of the hydrocarbon resin before hydrogenation contained in the catalyst residue removal mixture. The amount is preferably 0.01 parts by mass to 5.0 parts by mass, more preferably 0.03 parts by mass to 3.0 parts by mass, and still more preferably 0.05 parts by mass to 2.0 parts by mass.

The temperature at which the catalyst residue removal mixture is brought into contact with the adsorbent is not particularly limited, but is usually selected within the range of 10°C to 70°C, and the treatment time is also not particularly limited, but is usually 0.1 hour to 70°C. Selected within 2 hours.

When the catalyst residue removal mixture and the adsorbent are contacted in a batch process, the adsorbent may be removed from the catalyst residue removal mixture by filtration or the like, or the adsorbent may be removed from the catalyst residue removal mixture, if necessary. may be subjected to the next step without being removed.

The hydrogenated hydrocarbon resin used in the present invention is obtained by hydrogenating the above-mentioned hydrocarbon resin before hydrogenation.

The hydrogenated hydrocarbon resin has an olefin hydrogenation rate (hereinafter sometimes simply referred to as hydrogenation rate) of preferably 10% to 80%, more preferably 30% to 80%, and still more preferably 30% to 70%, particularly preferably 40% to 60%. The hydrogenation rate of olefin means the proportion of hydrogenated non-aromatic carbon-carbon double bonds among all non-aromatic carbon-carbon double bonds in the hydrocarbon resin before hydrogenation. By setting the hydrogenation rate within the above range, odor can be further reduced while maintaining a high holding force of the electrical insulating tape and effectively suppressing changes in adhesive strength over time.

Further, when the hydrogenated hydrocarbon resin contains an aromatic monomer unit, the hydrogenation rate of the aromatic ring is preferably 1% to 30%, more preferably 6% to 18%, even more preferably is 7% to 15%. The hydrogenation rate of aromatic rings means the proportion of hydrogenated aromatic rings among all the aromatic rings of the hydrocarbon resin before hydrogenation.

The hydrogenation rate of the olefin or aromatic ring mentioned above can be determined from the difference in the amount of olefin or aromatic ring contained in the hydrocarbon resin before hydrogenation and the hydrogenated hydrocarbon resin after hydrogenation. These can be determined by ¹ H-NMR spectrum measurement.

The weight average molecular weight (Mw) of the hydrogenated hydrocarbon resin is preferably 1,000 to 3,500, more preferably 1,500 to 3,400, even more preferably 1,800 to 3,300, and particularly preferably is 2,100 to 2,800. By setting the weight average molecular weight (Mw) within the above range, the compatibility with the aromatic vinyl block copolymer can be further increased, thereby further increasing the adhesive strength as an adhesive, and , it is possible to further increase the holding power of the electrical insulating tape.

Further, the Z average molecular weight (Mz) of the hydrogenated hydrocarbon resin is preferably 2,000 to 7,000, more preferably 3,200 to 6,800, even more preferably 3,900 to 6,600. 4,300 to 5,700 is particularly preferable. By setting the Z average molecular weight (Mz) within the above range, the compatibility with the aromatic vinyl block copolymer can be further improved, and thereby the adhesive strength of the electrical insulating tape can be further improved.

In the present invention, the weight average molecular weight (Mw) and Z average molecular weight (Mz) of the hydrogenated hydrocarbon resin can be determined as polystyrene equivalent values by measurement using high performance liquid chromatography. More specifically, the weight average molecular weight and Z average molecular weight can be determined as polystyrene equivalent molecular weight by high performance liquid chromatography using tetrahydrofuran as a carrier.

The ratio of the Z average molecular weight to the weight average molecular weight (Mz/Mw) of the hydrogenated hydrocarbon resin is preferably 1.5 to 2.5, more preferably 1.6 to 2.4, even more preferably 1.65 to It is 2.35. By setting the ratio of the Z average molecular weight to the weight average molecular weight within the above range, the compatibility with the aromatic vinyl block copolymer can be further increased, and thereby the adhesive strength as an adhesive can be further increased. In addition, the holding power of the electrical insulating tape can be further increased.

The Gardner color number of the 50% by mass toluene solution of the hydrogenated hydrocarbon resin is preferably 3 or less, more preferably 2 or less. When the Gardner color number is within this range, the hot melt adhesive composition can have excellent hue. A method for measuring the Gardner color number includes a method of preparing a 50% by mass toluene solution of a hydrogenated hydrocarbon resin as a sample, and measuring the Gardner color number of the prepared toluene solution in accordance with JIS K 0071-2.

Further, the softening point of the hydrogenated hydrocarbon resin is not particularly limited, but is preferably 50°C or higher, more preferably 50°C or higher, from the viewpoint of further increasing the compatibility with the aromatic vinyl block copolymer. The temperature range is from 125°C to 125°C, more preferably from 60°C to 115°C, particularly preferably from 80°C to 110°C. The softening point of hydrogenated hydrocarbon resin can be measured according to JIS K 6863.

The difference in the mixed aniline point (MMAP) of the hydrogenated hydrocarbon resin before and after hydrogenation, that is, obtained by subtracting the mixed aniline point of the hydrocarbon resin before hydrogenation from the mixed aniline point of the hydrogenated hydrocarbon resin, The difference in the mixed aniline points is preferably 5°C or less, more preferably 4°C or less, even more preferably 3.5°C or less. By setting the difference in the mixed aniline point within the above range, the compatibility with the aromatic vinyl block copolymer can be further increased, thereby further increasing the adhesive strength as an adhesive, and The holding power of electrical insulating tape can be further increased.

The lower limit of the difference in the mixed aniline point is preferably as low as possible from the viewpoint of further increasing the adhesive force as an adhesive; however, it can be set to 0° C. or higher, for example. Here, the mixed aniline point is the lowest temperature at which a mixture of aniline, measurement sample, and methylcyclohexane (volume ratio 2:1:1) exists as a homogeneous solution. The mixed aniline point can be measured according to JIS K 2256 using methylcyclohexane instead of heptane.

The mixed aniline point of the hydrogenated hydrocarbon resin is preferably 40°C to 120°C, more preferably 45°C to 110°C, even more preferably 50°C to 100°C. By setting the mixed aniline point within the above range, the compatibility with the aromatic vinyl block copolymer can be further increased, which can further increase the adhesive strength as an adhesive, and also improve electrical insulation. The holding power of the tape can be further increased.

Methods for producing hydrogenated hydrocarbon resins include, but are not particularly limited to, methods of hydrogenating hydrocarbon resins before hydrogenation. Hydrogenation of the hydrocarbon resin before hydrogenation can be performed by bringing the hydrocarbon resin before hydrogenation into contact with hydrogen in the presence of a hydrogenation catalyst.

As a hydrogenation catalyst, JP-A-58-43412, JP-A-60-26024, JP-A-64-24826, JP-A-1-138257, JP-A-7-41550, etc. It is possible to use what has been described, both homogeneous and heterogeneous catalysts.

Examples of homogeneous catalysts include combinations of cobalt acetate/triethylaluminum, nickel acetylacetonate/triisobutylaluminum, titanocene dichloride/n-butyllithium, zirconocene dichloride/sec-butyllithium, tetrabutoxytitanate/dimethylmagnesium, etc. Catalyst systems consisting of a combination of a transition metal compound and an alkali metal compound; noble metal complex catalysts such as dichlorobis(triphenylphosphine)palladium, chlorohydridocarbonyltris(triphenylphosphine)ruthenium, and chlorotris(triphenylphosphine)rhodium; etc. .

Examples of the heterogeneous catalyst include those in which a hydrogenation catalyst metal such as Ni and Pd is supported on a carrier. Examples of the carrier include silica, alumina, silica-alumina, diatomaceous earth, and the like. Among these, a Ni catalyst supported on silica is preferred.

The hydrogenation reaction may be carried out directly on the hydrocarbon resin before hydrogenation, or may be carried out in an organic solvent by dissolving the hydrocarbon resin before hydrogenation. From the viewpoint of ease of operation, a method in which the hydrocarbon resin is directly subjected to hydrogenation is preferred. The organic solvent used to dissolve the hydrocarbon resin before hydrogenation is not particularly limited as long as it is inert to the catalyst, but carbonization Hydrogen solvents are preferably used.

Examples of the hydrocarbon solvent include aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as n-pentane and hexane; alicyclic hydrocarbons such as cyclohexane and decalin; Among these, cyclic aromatic hydrocarbons and alicyclic hydrocarbons are preferred. These organic solvents can be used alone or in combination of two or more. In addition, as the organic solvent, the solvent used in the polymerization of the hydrocarbon resin before hydrogenation may be used as it is.

The method of bringing the hydrocarbon resin before hydrogenation into contact with hydrogen in the presence of a hydrogenation catalyst is not particularly limited, but for example, the hydrocarbon resin before hydrogenation and the hydrogenation catalyst may coexist in an appropriately selected container. There is a batch treatment method in which the resin is brought into contact with hydrogen, with stirring as necessary, or a hydrogenation catalyst is filled in a packed column in advance, and the hydrocarbon resin before hydrogenation is passed through the column and hydrogen and hydrogen are added. A continuous treatment method involving contact may be mentioned.

The hydrogenation reaction can be carried out according to a conventional method, and the hydrogenation rate of the hydrocarbon resin before hydrogenation can be adjusted by appropriately adjusting the reaction conditions such as the type of hydrogenation catalyst and reaction temperature. . For example, by using a homogeneous catalyst as a hydrogenation catalyst, the hydrogenation rate of the obtained hydrogenated hydrocarbon resin can be made relatively high.In this case, a ruthenium homogeneous catalyst is used as a homogeneous catalyst. Suitably used. The reaction temperature is preferably 100°C to 200°C, more preferably 130°C to 195°C.

In addition, by using a heterogeneous catalyst as a hydrogenation catalyst, the proportion of hydrogenated hydrocarbon resin obtained can be made relatively low, and in this case, a nickel heterogeneous catalyst is used as the heterogeneous catalyst. Suitably used. The reaction temperature is preferably 150°C to 300°C, more preferably 180°C to 260°C.

The hydrogen pressure in the hydrogenation reaction is usually in the range of 0.01 MPa to 10 MPa, preferably in the range of 0.05 MPa to 6 MPa, and more preferably in the range of 0.1 MPa to 5 MPa, in terms of absolute pressure.

After the hydrogenation reaction is completed, the hydrogenation catalyst is removed from the reaction solution by centrifugation, filtration, or the like, if necessary. The centrifugation method and filtration method are not particularly limited as long as the conditions allow removal of the catalyst used. When filtering, pressure filtration or suction filtration may be used, and from the viewpoint of efficiency, it is preferable to use a filter aid such as diatomaceous earth or perlite. Further, if necessary, a catalyst deactivator such as water or alcohol may be used, or an adsorbent such as activated clay or alumina may be added.

In addition, the hydrogenation rate of the olefin of the hydrogenated hydrocarbon resin, the hydrogenation rate of the aromatic ring, the weight average molecular weight (Mw), the Z average molecular weight (Mz), the ratio of the Z average molecular weight to the weight average molecular weight (Mz/Mw), The softening point, Gardner color number, the difference in mixed aniline point (MMAP) before and after hydrogenation, etc. can be adjusted by appropriately adjusting the manufacturing conditions, etc. in the formulation and manufacturing method as described above.

(Hot melt adhesive composition)
The hot melt adhesive composition used in the present invention contains the above-mentioned aromatic vinyl block copolymer and the above-mentioned hydrogenated hydrocarbon resin.

Furthermore, the hot melt adhesive composition used in the present invention has a toluene volatile content of 260 μg/m ³ or less and a total volatile component content of 15,000 μg/m 3 or less when heated at 65° C. for 2 hours. m ³ or less. The amount of toluene volatile matter when heated at 65° C. for 2 hours is preferably 240 μg/m ³ or less, more preferably 200 μg/m ³ or less, more preferably 180 μg/m ³ or less, and the lower limit thereof Although not particularly limited, it is usually 1 μg/m ³ or more. Further, the total amount of volatile components when heated at 65°C for 2 hours is preferably 15,000 μg/m ³ or less, more preferably 14,000 μg/m ³ or less, and the lower limit is not particularly limited. is usually 1,000 μg/m ³ or more. The amount of volatile components of toluene and the amount of total volatile components when heated at 65°C for 2 hours are determined by, for example, JASO (Japan Automobile Engineers Society Standard) M902 (2007) "Automotive Parts - Interior Materials - Volatile Organic Compounds". It can be measured in accordance with the "radiometry method".

Furthermore, the hot melt adhesive composition used in the present invention has a peel adhesion force of 400 N/m or more to a stainless steel plate, measured at a temperature of 23°C, a peel angle of 180°, and a tensile speed of 300 mm/min. It is what was done. The peel adhesion force to a stainless steel plate measured at a temperature of 23°C, a peel angle of 180°, and a tensile speed of 300 mm/min is, for example, according to PSTC-101 (180° peel adhesion test by the United States Adhesive Tape Committee). can be measured. The peel adhesive force to the stainless steel plate, measured at a temperature of 23° C., a peel angle of 180°, and a tensile speed of 300 mm/min, is preferably 450 N/m or more, more preferably 500 N/m or more, and even more preferably is 530 N/m or more, and although the upper limit is not particularly limited, it is usually 700 N/m or less.

According to the present invention, the amount of volatile components of toluene and the amount of total volatile components when heated at 65° C. for 2 hours are controlled within the above range, and the temperature is 23° C., the peeling angle is 180°, and the amount of volatile components is controlled within the above range. By using a hot melt adhesive composition whose peel adhesion to a stainless steel plate is controlled to be 400 N/m or more when measured at a tensile speed of 300 mm/min, electrical insulating tape can be made with low odor and high It has adhesive strength and can suppress changes in adhesive strength over time. In addition, as a method for keeping the toluene volatile content and total volatile component content within the above range when heated at 65 ° C. for 2 hours, as a hydrogenated hydrocarbon resin to suppress volatile components due to thermal deterioration, A method of adjusting the hydrogenation rate of olefin in the hydrogenated hydrocarbon resin to the above-mentioned preferred range using a hydrocarbon resin obtained by hydrogenating a pre-hydrogenated hydrocarbon resin having the above-mentioned specific composition range, and hot melt A method of using a block copolymer composition containing the above-mentioned block copolymer A and block copolymer B as an aromatic vinyl block copolymer in order to obtain excellent adhesive properties that can be produced by the method This is achieved by using

The content ratio of the aromatic vinyl block copolymer and hydrogenated hydrocarbon resin in the hot melt adhesive composition used in the present invention is not particularly limited, but is based on 100 parts by mass of the aromatic vinyl block copolymer. The content of the hydrogenated hydrocarbon resin is preferably 50 parts by mass to 500 parts by mass, more preferably 80 parts by mass to 400 parts by mass, and still more preferably 100 parts by mass to 300 parts by mass. By setting the content ratio of the hydrogenated hydrocarbon resin to the aromatic vinyl block copolymer within the above range, the adhesive strength of the hot melt adhesive composition as an adhesive can be further increased, and The holding power of the electrical insulating tape can be further increased, and changes in adhesive strength over time can be more effectively suppressed.

Further, it is preferable that the hot melt adhesive composition used in the present invention further contains a softening agent. agent can be used. Specifically, aromatic, paraffinic or naphthenic process oils; liquid polymers such as polybutene and polyisobutylene; and the like. One type of softener may be used alone, or two or more types may be used in combination. The content ratio of the softener in the hot melt adhesive composition used in the present invention is 500 parts by mass or less, preferably 10 parts by mass to 350 parts by mass, based on 100 parts by mass of the aromatic vinyl block copolymer. Parts by weight, more preferably 30 parts by weight to 250 parts by weight. By containing the softener in the above content ratio, the hot melt adhesive composition can be easily applied at relatively low temperatures, making it easier to manufacture electrical insulating tapes. can be taken as a thing.

In addition, when the hot melt adhesive composition used in the present invention further contains a softener in addition to the aromatic vinyl block copolymer and the hydrogenated hydrocarbon resin, the content ratio of these is preferably as follows. That is, the content of the aromatic vinyl block copolymer is preferably 10% by mass to 60% by mass, more preferably 20% by mass to 57.5% by mass, even more preferably 30% by mass to 55% by mass. be. Further, the content of the hydrogenated hydrocarbon resin is preferably 20% by mass to 80% by mass, more preferably 20% by mass to 65% by mass, and even more preferably 30% by mass to 60% by mass. The content of the softener is preferably 0.1% by mass to 30% by mass, more preferably 0.1% by mass to 25% by mass, still more preferably 5% by mass to 20% by mass. By setting the content ratio of the aromatic vinyl block copolymer, the content ratio of the hydrogenated hydrocarbon resin, and the content ratio of the softener within the above-mentioned ranges, the hot melt adhesive composition can be improved in adhesive strength as an adhesive. In addition, it is possible to further increase the holding power of the electrical insulating tape, and it is also possible to more effectively suppress changes in adhesive strength over time.

Further, other compounding agents such as wax, antioxidant, heat stabilizer, ultraviolet absorber, filler, etc. can be added to the hot melt adhesive composition used in the present invention. Note that the hot melt adhesive composition used in the present invention is preferably a solvent-free composition that does not contain a solvent.

The wax that can be blended into the hot melt adhesive composition used in the present invention is not particularly limited, and examples thereof include polyethylene wax, ethylene vinyl acetate copolymer wax, oxidized polyethylene wax, paraffin wax, microcrystalline wax, and Fischer wax. Tropsh wax, oxidized Fischer-Tropsh wax, hydrogenated castor oil wax, polypropylene wax, by-product polyethylene wax, hydroxylated stearamide wax, and the like can be used. One type of wax may be used alone, or two or more types may be used in combination. The content of wax in the hot melt adhesive composition is not particularly limited, but is preferably 10 to 200 parts by mass, more preferably 20 to 150 parts by mass, based on 100 parts by mass of the aromatic vinyl block copolymer. Department. When the wax content is within this range, the resulting hot-melt adhesive composition has particularly excellent ease of application, making it easier to manufacture an electrical insulating tape.

The antioxidant that can be blended into the hot melt adhesive composition used in the present invention is not particularly limited, and examples thereof include pentaerythritol tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)] propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,6-di-t-butyl-p-cresol, di-t-butyl-4-methylphenol, etc. Examples include hindered phenol compounds; thiodicarboxylate esters such as dilaurylthiopropionate; phosphites such as tris(nonylphenyl) phosphite; and the like. The amount of antioxidant used is not particularly limited, but is usually 10 parts by weight or less, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the aromatic vinyl block copolymer. In addition, one type of antioxidant may be used alone, or two or more types may be used in combination.

In preparing the hot melt adhesive composition used in the present invention, in addition to the aromatic vinyl block copolymer and hydrogenated hydrocarbon resin, a softener and other components added as necessary are added. The mixing method is not particularly limited, but from the viewpoint of performing the mixing more efficiently and controlling the toluene volatile content and the total volatile content within the above ranges, each component may be mixed using a kneader or the like without using a solvent. A method of melt-mixing is preferred. The temperature at which melt mixing is performed is not particularly limited, but it is preferable to perform melt mixing at 220 ° C. or lower, more preferably 200 ° C. or lower, and even more preferably 180 ° C. or lower. By performing melt mixing in the above range, the amount of toluene volatile components and the total amount of volatile components can be appropriately controlled within the above ranges. In addition, as for the mixing method, from the viewpoint of controlling the toluene volatile content and the total volatile component content more appropriately, the aromatic vinyl block copolymer and the hydrogenated hydrocarbon resin were mixed with the aromatic vinyl block copolymer 100% After melt-mixing the hydrogenated hydrocarbon resin at a ratio of 50 to 100 parts by mass to parts by mass, the remaining components containing the hydrogenated hydrocarbon resin (excluding components containing relatively large amounts of volatile components such as softeners, A preferred method is to add the remaining components) and melt-mix them, and finally add and melt-mix a component containing a relatively large amount of volatile components (for example, a softener). Further, in the melt mixing, from the viewpoint of more appropriately controlling the amount of toluene volatile components and the total amount of volatile components, melt mixing using a twin-screw extruder is preferable. In melt mixing using a twin-screw extruder, the aromatic vinyl block copolymer and the hydrogenated hydrocarbon resin are added to 100 parts by mass of the aromatic vinyl block copolymer in the first half of the twin-screw extruder. , hydrogenated hydrocarbon resin at a ratio of 50 to 100 parts by mass, these are melt-mixed, and the remaining components including the hydrogenated hydrocarbon resin (volatile components such as softeners) are added in the middle part of a twin-screw extruder. The remaining components (excluding the components that contain relatively large amounts) are added and melt-mixed, and in the latter half of the twin-screw extruder, components that contain relatively large amounts of volatile components (e.g., softeners) are added and melt-mixed. The method of doing so is preferable.

(Base material)
The base material used in the present invention is not particularly limited, but includes, for example, fiber fabrics such as organic fiber fabrics, inorganic fiber fabrics, and organic/inorganic fiber fabrics; organic fiber nonwoven fabrics, and inorganic fiber fabrics. Examples include nonwoven fabrics such as nonwoven fabrics made of nonwoven fabrics and nonwoven fabrics made of organic and inorganic fibers; films made of plastics such as PVC, polyester, and polypropylene. The thickness of the base material is not particularly limited and may be appropriately determined depending on the use of the electrical insulating tape, but is usually about 1 μm to 1000 μm.

(electrical insulation tape)
The electrical insulating tape of the present invention includes a hot melt adhesive composition and a base material.
The electrical insulating tape of the present invention may be any tape as long as it includes a hot melt adhesive composition and a base material, and is not particularly limited. Examples include those in which a pressure-sensitive adhesive layer made of a melt pressure-sensitive adhesive composition is formed. In addition, when using fiber cloth, nonwoven fabric, etc. as the base material, it is sufficient that the adhesive layer made of the hot melt adhesive composition is formed on the surface of the base material, and it is not necessarily necessary to The adhesive layer made of the melt adhesive composition does not need to be formed by impregnating the hot melt adhesive composition into such a base material. Alternatively, the hot melt adhesive composition is impregnated into fiber cloth or nonwoven fabric, but no adhesive layer made of the hot melt adhesive composition is formed on the surface. It may be.

The method for producing the electrical insulating tape of the present invention is not particularly limited, and examples thereof include a method of applying a molten hot melt adhesive composition to at least a portion of the surface of the base material, a method of applying the molten hot melt adhesive composition to at least a portion of the surface of the base material, and a method of applying the melted hot melt adhesive composition to at least a portion of the surface of the base material, Examples of the method include applying a hot melt adhesive composition to at least a portion of the surface of the base material, and then removing the solvent by heating or the like. Alternatively, when using fiber cloth, nonwoven fabric, etc. as the base material, a method of impregnating at least a part of the base material with a molten hot melt adhesive composition, or a method of impregnating at least a part of the base material with a molten hot melt adhesive composition, or The electrical insulating tape of the present invention can also be produced by a method in which at least a portion of the base material is impregnated with the melt adhesive composition and then the solvent is removed by heating or the like.

The electrical insulating tape of the present invention has low odor, suppresses changes in adhesive strength over time, and has excellent holding power.Using these properties, it can be used in various parts that require electrical insulation. For example, it can be suitably used in wire harnesses, transformers, electric/electronic equipment, automobile drive motors, industrial motors, batteries, and the like.

The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Note that "parts" and "%" are based on mass unless otherwise specified.
Various measurements were performed according to the following methods.

[Block copolymer composition and weight average molecular weight of each block copolymer in the block copolymer composition]
The molecular weight was determined in terms of polystyrene by high performance liquid chromatography using tetrahydrofuran as a carrier at a flow rate of 0.35 mL/min. The device used was HLC8220 manufactured by Tosoh Corporation, the column used was a combination of three Shodex (registered trademark) KF-404HQ manufactured by Showa Denko Co., Ltd. (column temperature 40 ° C.), and the detector used was a differential refractometer and an ultraviolet detector. Calibration of molecular weight was performed using 12 points of standard polystyrene (500 to 3 million) manufactured by Polymer Laboratory.

[Content of each block copolymer in the block copolymer composition]
It was determined from the area ratio of the peaks corresponding to each block copolymer in the chart obtained by the above-mentioned high performance liquid chromatography.

[Weight average molecular weight of styrene polymer block of block copolymer]
Rubber Chem. Technol. The isoprene polymer blocks of the block copolymer were decomposed by reacting the block copolymer with ozone and reducing it with lithium aluminum hydride according to the method described in J.D., 45, 1295 (1972). Specifically, the following steps were performed. That is, 300 mg of the sample was dissolved in a reaction vessel containing 100 mL of dichloromethane treated with molecular sieve. The reaction vessel was placed in a cooling tank and cooled to −25° C., and then ozone generated by an ozone generator was introduced while oxygen was flowing into the reaction vessel at a flow rate of 170 mL/min. After 30 minutes from the start of the reaction, completion of the reaction was confirmed by introducing the gas flowing out from the reaction vessel into the aqueous potassium iodide solution. Next, 50 mL of diethyl ether and 470 mg of lithium aluminum hydride were placed in another reaction vessel purged with nitrogen, and the solution reacted with ozone was slowly dropped into the reaction vessel while cooling the reaction vessel with ice water. Then, the reaction container was placed in a water bath, and the temperature was gradually raised to reflux at 40° C. for 30 minutes. Thereafter, while stirring the solution, dilute hydrochloric acid was added dropwise little by little into the reaction vessel, and the dropwise addition was continued until almost no hydrogen generation was observed. After this reaction, the solid product formed in the solution was filtered off, and the solid product was extracted with 100 mL of diethyl ether for 10 minutes. This extract and the filtrate obtained by filtration were combined, and the solvent was distilled off to obtain a solid sample. The weight average molecular weight of the sample thus obtained was measured according to the method for measuring weight average molecular weight described above, and the value was taken as the weight average molecular weight of the styrene polymer block.

[Weight average molecular weight of isoprene polymer block of block copolymer]
Subtract the weight average molecular weight of the corresponding styrene polymer block from the weight average molecular weight of the block copolymer determined as above, and then calculate the weight average molecular weight of the isoprene polymer block based on the calculated value. Ta.

[Styrene unit content of block copolymer]
It was determined based on the detection intensity ratio between the differential refractometer and the ultraviolet detector in the above-mentioned high performance liquid chromatography measurement. Note that copolymers having different styrene unit contents were prepared in advance, and a calibration curve was created using them.

[Styrene unit content of block copolymer composition (whole)]
It was determined based on proton NMR measurements.

[Weight average molecular weight, Z average molecular weight and molecular weight distribution (Mz/Mw) of hydrogenated hydrocarbon resin]
The hydrogenated hydrocarbon resin was analyzed by gel permeation chromatography to determine the weight average molecular weight (Mw) and Z average molecular weight (Mz) in terms of standard polystyrene, and the molecular weight distribution was expressed as the ratio of Mz/Mw. For gel permeation chromatography analysis, "HLC-8320GPC" manufactured by Tosoh Corporation was used as a measuring device, and a column consisting of three "TSKgel SuperMultiporeHZ" manufactured by Tosoh Corporation was used, and tetrahydrofuran was used as a solvent. , 40° C., and a flow rate of 1.0 mL/min.

[Gardner color number of 50% by mass toluene solution of hydrogenated hydrocarbon resin]
A 50% by mass toluene solution of the hydrogenated hydrocarbon resin was prepared, and the Gardner color number of the solution was measured according to JIS K 0071-2. The smaller the value, the better the hue.

[Softening point of hydrogenated hydrocarbon resin (℃)]
The hydrogenated hydrocarbon resin was measured according to JIS K 6863.

[Olefin hydrogenation rate (%) of hydrogenated hydrocarbon resin]
For the hydrocarbon resin before hydrogenation and the hydrogenated hydrocarbon resin after hydrogenation, the amount of each olefin is determined by ¹ H-NMR spectrum measurement, and the olefin hydrogenation rate (%) is determined based on the difference in the amount of olefin before and after hydrogenation. ) was calculated. In the ¹ H-NMR spectrum measurement, deuterated chloroform was used as the solvent, and JMN-AL series AL400 (manufactured by JEOL) was used as the NMR measuring device.

[Toluene volatile component amount and total volatile component amount of hot melt adhesive composition]
A hot melt adhesive composition of approximately 100 mm x 100 mm x 0.04 mm was heated at 65°C for 2 hours in accordance with JASO M902 (2007) "Automotive parts - Interior materials - Volatile organic compound emission measurement method". The amount of toluene volatile components and the total amount of volatile components when heated under the following conditions were measured.

[Odor evaluation test of hot melt adhesive composition]
A sensory test on the hot melt adhesive composition was conducted according to the odor intensity display method in the odor olfactory measurement method published by the Odor Control Research Association. Specifically, first, 10 g of a hot-melt adhesive composition each having a size of approximately 10 mm x 5 mm x 5 mm was placed in a 120 mL heat-resistant container, and the container was covered with aluminum foil. Then, the heat-resistant container containing this hot-melt adhesive composition was placed in an oven and heated at a temperature of 150° C. for 30 minutes, and the odor after heating was checked.
The odor was checked by a panel of 6 people who were not accustomed to the odor of petroleum resins (that is, those who do not come into contact with the odor of petroleum resins in their daily lives). In this test, in order to prevent olfactory fatigue, a panel of six people was divided into two groups of three people each, and each group sniffed the odor. Additionally, the order of the samples to be sniffed was randomized.
1: Odor that can barely be recognized (detection threshold concentration)
2: Weak odor that allows you to identify what it is (recognition threshold concentration)
3: Easily perceivable odor 4: Strong odor 5: Strong odor The results of the sensory test are based on the judgment values of the 6 panelists, excluding the maximum and minimum values, and comparing the judgment values of the remaining 4 panelists. It was determined by averaging. The smaller the value in the sensory test, the better.

[Peel adhesion strength of hot melt adhesive composition (initial stage)]
The resulting hot-melt adhesive composition is melted at 180°C and applied to a 50-μm-thick polyester film to a thickness of 30 μm, thereby forming an adhesive made of the hot-melt adhesive composition. A sample with an adhesive layer formed thereon was prepared. This was measured at 23°C and a tensile speed of 300 mm/min using a stainless steel plate as the adherend in accordance with PSTC-101 (180° peel adhesion test by the United States Adhesive Tape Committee). Adhesive strength (N/m) was evaluated. The larger the value, the better the adhesive force.

[Peel adhesion strength of hot melt adhesive composition after aging]
The sample with the adhesive layer prepared above was aged at 65°C for 2 weeks, and the aged sample was aged at 23°C at a tensile speed of 300 mm/min using a stainless steel plate as an adherend. The peel adhesion strength (N/m) after aging at 65° C. for 2 weeks was evaluated by measuring according to PSTC-101 (180° peel adhesion test by the United States Adhesive Tape Committee). The smaller the change in value from the peel adhesive force (initial), the more suppressed the change in adhesive force over time, which is desirable.

[Holding power of hot melt adhesive composition]
Using a stainless steel plate as an adherend, the sample with the adhesive layer prepared above was prepared according to PSTC-107 Procedure A (retention force test method by the United States Adhesive Tape Committee), with an adhesive area of 10 x 25 mm, The holding power was evaluated by the time (minutes) until peeling at a load of 3.92×10 ⁴ Pa and a temperature of 50° C. The larger the value, the better the holding power.

[Manufacture example 1]
23.3 kg of cyclohexane, 2.57 mmol of N,N,N',N'-tetramethylethylenediamine (hereinafter referred to as TMEDA) and 1.10 kg of styrene were added to a pressure-resistant reactor, and the mixture was stirred at 40°C. Then, 85.7 mmol of n-butyllithium was added, and polymerization was carried out for 1 hour while raising the temperature to 50°C. The polymerization conversion rate of styrene was 100%. Subsequently, 7.00 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain the temperature at 50-60°C. After the addition of isoprene was completed, the polymerization was further carried out for 1 hour, and then 60.0 mmol of methanol was added to the reactor as a polymerization terminator, and the polymerization was terminated for 1 hour to form a styrene-isoprene block copolymer with active terminals. A styrene-isoprene diblock copolymer, which will become block copolymer B, was formed by deactivating some of the active terminals of the polymer. Thereafter, 1.90 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain the temperature at 50 to 60°C. After completing the addition of styrene, polymerization was further carried out for 1 hour to form a styrene-isoprene-styrene block copolymer that would become block copolymer A. The polymerization conversion rate of styrene was 100%. Thereafter, 171.4 mmol of methanol was added as a polymerization terminator, and the mixture was thoroughly mixed to terminate the reaction.

To 100 parts of the reaction solution obtained as above (containing 30 parts of polymer component), 0.3 part of 2,6-di-tert-butyl-p-cresol was added as an antioxidant and mixed. Production Example 1 A block copolymer composition (α1) was recovered. In addition, a part of the obtained reaction solution was taken out, and the weight average molecular weight of each polymer contained, the weight ratio of each polymer in the polymer component, and the weight average molecular weight of the styrene polymer block of each block copolymer were determined. , the weight average molecular weight of the isoprene polymer block of each block copolymer, the styrene unit content of each block copolymer, the styrene unit content of the polymer component (total), and the isoprene polymer block of each block copolymer. The vinyl bond content was determined. The results are shown in Table 1.

[Production example 2]
23.3 kg of cyclohexane, 2.36 mmol of TMEDA, and 2.40 kg of styrene were added to a pressure-resistant reactor, and while stirring at 40°C, 154.1 mmol of n-butyllithium was added and the temperature was raised to 50°C. Polymerization was carried out for 1 hour. The polymerization conversion rate of styrene was 100% by weight. Subsequently, 7.60 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain the temperature at 50-60°C. After the addition of isoprene was completed, polymerization was continued for an additional hour. The polymerization conversion rate of isoprene was 100%. Next, 25.4 mmol of dimethyldichlorosilane was added as a coupling agent and a coupling reaction was carried out for 2 hours to form a styrene-isoprene-styrene block copolymer that would become block copolymer C. Thereafter, 308.2 mmol of methanol was added as a polymerization terminator, and the reaction was stopped by thorough mixing to form a styrene-isoprene diblock copolymer that would become block copolymer B.

To 100 parts of the reaction solution obtained as above (containing 30 parts of polymer component), 0.3 part of 2,6-di-tert-butyl-p-cresol was added as an antioxidant and mixed. Production Example 2 A block copolymer composition (α2) was recovered. In addition, a portion of the obtained reaction solution was taken out and each measurement was performed in the same manner as in Production Example 1. The results are shown in Table 1.

[Manufacture example 3]
23.3 kg of cyclohexane, 1.27 mmol of TMEDA, and 0.90 kg of styrene were added to a pressure-resistant reactor, and while stirring at 40°C, 84.5 mmol of n-butyllithium was added and the temperature was raised to 50°C. Polymerization was carried out for 1 hour. The polymerization conversion rate of styrene was 100%. Subsequently, 8.20 kg of isoprene was continuously added to the reactor over 1 hour while controlling the temperature to maintain the temperature at 50-60°C. After the addition of isoprene was completed, polymerization was continued for an additional hour. Thereafter, 0.90 kg of styrene was continuously added over 1 hour while controlling the temperature to maintain the temperature at 50 to 60°C. After the addition of styrene was completed, polymerization was further carried out for 1 hour to obtain a styrene-isoprene-styrene block copolymer. The polymerization conversion rate of styrene was 100%. Thereafter, 169.0 mmol of methanol was added as a polymerization terminator, and the mixture was thoroughly mixed to terminate the reaction.

To 100 parts of the reaction solution obtained as above (containing 30 parts of polymer component), 0.3 part of 2,6-di-tert-butyl-p-cresol was added as an antioxidant and mixed. Production example 3 A styrene-isoprene-styrene block copolymer (α3) was recovered. In addition, a portion of the obtained reaction solution was taken out and each measurement was performed in the same manner as in Production Example 1. The results are shown in Table 1. In Table 1, the styrene-isoprene-styrene block copolymer (α3) according to Production Example 3 is described as block copolymer A.

[Manufacture example 4]
A mixture of 50.3 parts of cyclopentane and 37.2 parts of cyclopentene was charged into a polymerization reactor, and the temperature was raised to 60° C., and then 1.0 part of aluminum chloride was added to obtain a mixture M1. Subsequently, 49.5 parts of 1,3-pentadiene, 9.2 parts of isobutylene, 0.6 parts of C4-C6 unsaturated hydrocarbon, 2.1 parts of dicyclopentadiene, 0.1 part of cyclopentadiene, and C4-C6 saturated Mixture M2 consisting of 12.0 parts of hydrocarbon and 0.2 part of benzylbutyl chloride were each passed through separate lines and the temperature (60°C) was maintained for 60 minutes to obtain the mixture obtained above. Polymerization was carried out while continuously adding M1 to the polymerization reactor containing M1. Thereafter, an aqueous sodium hydroxide solution was added to the polymerization reactor to stop the polymerization reaction. The types and amounts of components in the polymerization reactor during the polymerization reaction are summarized in Table 2. A precipitate generated by termination of polymerization was removed by filtration to obtain a polymer solution containing unmodified resin, unreacted monomers, and the like.
In addition, a portion of the obtained polymer solution is taken out, charged into a distillation pot, and heated in a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers, thereby converting the hydrocarbon resin before hydrogenation. sampled.

Then, the polymer solution obtained above is supplied as a raw material to a multi-tubular heat exchange type hydrogenation reactor, and the hydrocarbon resin before hydrogenation is hydrogenated to produce a hydrogenated hydrocarbon resin. Manufactured. The hydrogenation reaction was carried out using a nickel-silica catalyst (manufactured by JGC Catalysts & Chemicals Co., Ltd., N108F) as a hydrogenation catalyst, at a hydrogen pressure of 1.5 MPa, a reaction temperature of 220°C, and an amount of hydrogen of 2 parts (100% of the hydrocarbon resin before hydrogenation). The reaction time was 30 minutes in the reaction tube. Next, the resulting polymer solution containing the hydrogenated hydrocarbon resin was charged into a distillation pot and heated under a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers. Subsequently, low molecular weight oligomer components were distilled off at 200°C or higher while blowing saturated steam, the molten resin was taken out from the distillation pot, and the hydrogenated hydrocarbon of Production Example 4 was left to cool to room temperature. A resin (β1) was obtained.

Regarding the obtained hydrogenated hydrocarbon resin (β1) of Production Example 4, the weight average molecular weight, Z average molecular weight, Mz/Mw, Gardner color number, softening point, and olefin hydrogenation rate were determined. The measurement results are shown in Table 2.

[Manufacture example 5]
A mixture of 34.5 parts of cyclopentane and 28.8 parts of cyclopentene was charged into a polymerization reactor and heated to 60° C., and then 0.7 parts of aluminum chloride was added to obtain mixture M3. Subsequently, 46.1 parts of 1,3-pentadiene, 7.3 parts of isobutylene, 0.6 parts of C4-C6 unsaturated hydrocarbon, 1.1 parts of dicyclopentadiene, 0.1 part of cyclopentadiene, and 14.0 parts of styrene. , and 8.5 parts of a C4-C6 saturated hydrocarbon, and 0.5 part of t-butyl chloride were passed through separate lines, maintaining the temperature (80° C.) for 60 minutes, Polymerization was carried out while continuously adding the mixture M3 obtained above to the polymerization reactor. Thereafter, an aqueous sodium hydroxide solution was added to the polymerization reactor to stop the polymerization reaction. The types and amounts of components in the polymerization reactor during the polymerization reaction are summarized in Table 2. A precipitate generated by termination of polymerization was removed by filtration to obtain a polymer solution containing unmodified resin, unreacted monomers, and the like.
In addition, a portion of the obtained polymer solution is taken out, charged into a distillation pot, and heated in a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers, thereby converting the hydrocarbon resin before hydrogenation. sampled.

Then, the polymer solution obtained above is supplied as a raw material to a multi-tubular heat exchange type hydrogenation reactor, and the hydrocarbon resin before hydrogenation is hydrogenated to produce a hydrogenated hydrocarbon resin. Manufactured. The hydrogenation reaction was carried out using a nickel-silica catalyst (manufactured by JGC Catalysts & Chemicals Co., Ltd., N108F) as a hydrogenation catalyst, at a hydrogen pressure of 0.5 MPa, a reaction temperature of 180°C, and an amount of hydrogen of 1 part (hydrocarbon resin 100% before hydrogenation). The reaction time was 30 minutes in the reaction tube. Next, the resulting polymer solution containing the hydrogenated hydrocarbon resin was charged into a distillation pot and heated under a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers. Subsequently, low molecular weight oligomer components were distilled off at 200°C or higher while blowing saturated steam, the molten resin was taken out from the distillation pot, and the hydrogenated hydrocarbon of Production Example 5 was left to cool to room temperature. Resin (β2) was obtained.

Regarding the obtained hydrogenated hydrocarbon resin (β2) of Production Example 5, the weight average molecular weight, Z average molecular weight, Mz/Mw, Gardner color number, softening point, and olefin hydrogenation rate were determined. The measurement results are shown in Table 2.

[Example 1]
100 parts of the block copolymer composition (α1) obtained in Production Example 1 was charged into a stirring blade kneader, and 100 parts of the hydrogenated hydrocarbon resin (β1) obtained in Production Example 4 and naphthene-based 10 parts of process oil (trade name "Diana Process Oil NS-90S", manufactured by Idemitsu Kosan Co., Ltd.) and an antioxidant (trade name "Irganox 1010", pentaerythritol tetrakis [3-(3,5-di-tert- Butyl-4-hydroxyphenyl)propionate] (manufactured by BASF) was added and the system was replaced with nitrogen gas, and then kneaded at 160 to 180°C for 1 hour to form the hot melt adhesive of Example 1. An adhesive composition was prepared. During kneading, first, the block copolymer composition (α1), the hydrogenated hydrocarbon resin (β1), and the antioxidant are melt-mixed at 160 to 180°C, and finally, in the latter stage of the melt-mixing, The hot melt adhesive composition of Example 1 was prepared by adding naphthenic process oil and continuing melt mixing at 160 to 180°C (the same applies to each of the Examples and Comparative Examples described later). ). The resulting hot melt adhesive composition was subjected to measurements of toluene volatile component amount and total volatile component amount, odor evaluation test, peel adhesive strength (initial), and peel adhesive strength and holding power after time. went. The results are shown in Table 3.

[Example 2]
Example 1 except that the amount of hydrogenated hydrocarbon resin (β1) obtained in Production Example 4 was changed from 100 parts to 150 parts, and the amount of naphthenic process oil was changed from 10 parts to 20 parts. In the same manner as above, the hot melt adhesive composition of Example 2 was prepared and evaluated in the same manner. The results are shown in Table 3.

[Example 3]
The hot melt adhesive composition of Example 3 was prepared in the same manner as in Example 1, except that the amount of hydrogenated hydrocarbon resin (β1) obtained in Production Example 4 was changed from 100 parts to 90 parts. was prepared and evaluated in the same manner. The results are shown in Table 3.

[Example 4]
Example 1 except that 100 parts of the block copolymer composition (α2) obtained in Production Example 2 was used instead of 100 parts of the block copolymer composition (α1) obtained in Production Example 1. In the same manner, the hot melt adhesive composition of Example 4 was prepared and evaluated in the same manner. The results are shown in Table 3.

[Example 5]
The amount of the block copolymer composition (α1) obtained in Production Example 1 was changed from 100 parts to 50 parts, and 50 parts of the block copolymer composition (α2) obtained in Production Example 2 was changed. A hot melt adhesive composition of Example 5 was prepared in the same manner as in Example 1 except that it was further used, and evaluated in the same manner. The results are shown in Table 3.

[Example 6]
The procedure was the same as in Example 1, except that 120 parts of the hydrogenated hydrocarbon resin (β2) obtained in Production Example 5 was used instead of 100 parts of the hydrogenated hydrocarbon resin (β1) obtained in Production Example 4. The hot melt adhesive composition of Example 6 was prepared and evaluated in the same manner. The results are shown in Table 3.

[Comparative example 1]
Instead of 100 parts of the hydrogenated hydrocarbon resin (β1) obtained in Production Example 4, 100 parts of a non-hydrogenated hydrocarbon resin (trade name "Quinton R100", manufactured by Nippon Zeon Co., Ltd.) was used, and naphthene-based A hot melt adhesive composition of Comparative Example 1 was prepared in the same manner as in Example 1, except that no process oil was blended, and evaluated in the same manner. The results are shown in Table 3.

[Comparative example 2]
Comparison except that 100 parts of the block copolymer composition (α1) obtained in Production Example 1 was replaced with 100 parts of the styrene-isoprene-styrene block copolymer (α3) obtained in Production Example 3. A hot melt adhesive composition of Comparative Example 2 was prepared in the same manner as in Example 1, and evaluated in the same manner. The results are shown in Table 3.

[Comparative example 3]
100 parts of the styrene-isoprene-styrene block copolymer (α3) obtained in Production Example 3 was charged into a stirring blade kneader, and 100 parts of the hydrogenated hydrocarbon resin (β1) obtained in Production Example 4 was added thereto. , 10 parts of naphthenic process oil (trade name "Diana Process Oil NS-90S", manufactured by Idemitsu Kosan Co., Ltd.), antioxidant (trade name "Irganox 1010", pentaerythritol tetrakis [3-(3,5-di- After adding 1 part of tert-butyl-4-hydroxyphenyl) propionate (manufactured by BASF) and 316.5 parts of toluene as a solvent and purging the system with nitrogen gas, the system was stirred for 1 hour, and then dried. A hot melt adhesive composition of Comparative Example 3 was prepared by removing toluene. Then, the obtained hot melt adhesive composition was evaluated in the same manner as in Example 1. The results are shown in Table 3.

[Comparative example 4]
Instead of 100 parts of the hydrogenated hydrocarbon resin (β1) obtained in Production Example 4, 100 parts of a hydrogenated resin derived from cyclopentadiene (trade name "Imarv P100", manufactured by Idemitsu Kosan Co., Ltd.) was used, and A hot-melt adhesive composition of Comparative Example 4 was prepared in the same manner as in Example 1, except that naphthenic process oil was not blended, and evaluated in the same manner. The results are shown in Table 3.

[Comparative example 5]
Except that instead of 100 parts of the hydrogenated hydrocarbon resin (β1) obtained in Production Example 4, 100 parts of a hydrogenated resin derived from cyclopentadiene (trade name "Escolettes 5300", manufactured by ExxonMobil Chemical) was used. A hot melt adhesive composition of Comparative Example 5 was prepared in the same manner as in Example 1, and evaluated in the same manner. The results are shown in Table 3.

From Table 3, when containing an aromatic vinyl block copolymer and a hydrogenated hydrocarbon resin and heated at 65°C for 2 hours, the toluene volatile content was 260 μg/m3 or less, and the total volatile content was 260 μg/ ^m3 or less. A hot melt adhesive having a component content of 15,000 μg/m ³ or less and a peel adhesion force of 400 N/m or more to a stainless steel plate, measured at a temperature of 23°C, a peel angle of 180°, and a tensile speed of 300 mm/min. The adhesive compositions had low odor, high adhesive strength, and changes in adhesive strength over time were suppressed (Examples 1 to 6).
According to such a hot melt adhesive composition, when combined with a base material, an electrical insulating tape with low odor, high adhesive strength, and suppressed changes in adhesive strength over time can be provided. It can be said that it is possible.
On the other hand, when the amount of toluene volatile components exceeds 260 μg/m ³ or when the total amount of volatile components exceeds 15,000 μg/m ³ , the odor is strong, and the adhesive strength changes greatly over time, making it stable. The properties were poor (Comparative Examples 1 to 4).
Moreover, when the peel adhesion force was less than 400 N/m, the holding force was poor (Comparative Example 5).

Claims (10)

An electrical insulating tape comprising a hot melt adhesive composition and a base material,
The hot melt adhesive composition contains a block copolymer composition and a hydrogenated hydrocarbon resin,
The block copolymer composition includes a block copolymer A represented by the following general formula (I) and a block copolymer B represented by the following general formula (II),
The aromatic vinyl monomer unit content of the block copolymer A is greater than the aromatic vinyl monomer unit content of the block copolymer B,
The content of the block copolymer A in the block copolymer composition is 35 to 90% by mass,
When heated at 65° C. for 2 hours, the toluene volatile content of the hot melt adhesive composition is 260 μg/m ³ or less, and the total volatile component amount is 15,000 μg/m ³ or less,
An electrical insulating tape having a peel adhesion force of the hot melt adhesive composition to a stainless steel plate of 400 N/m or more, measured at a temperature of 23° C., a peel angle of 180°, and a tensile speed of 300 mm/min.
Ar1-D1-Ar2 (I)
Ar3-D2 (II)
(In the above general formulas (I) and (II), Ar1, Ar2 and Ar3 are each an aromatic vinyl polymer block, and D1 and D2 are each a conjugated diene polymer block.) The weight average molecular weight (Mw (Ar1)) of the aromatic vinyl polymer block Ar1 of the block copolymer A and the weight average molecular weight (Mw (Ar3)) of the aromatic vinyl polymer block Ar3 of the block copolymer B. The electrically insulating tape according to claim 1, wherein the electrically insulating tape is substantially the same as the electrically insulating tape. The ratio of the weight average molecular weight (Mw (D1)) of the conjugated diene polymer block D1 of the block copolymer A to the weight average molecular weight (Mw (D2)) of the conjugated diene polymer block D2 of the block copolymer B. The electrical insulating tape according to claim 1 or 2, wherein (Mw (D2)/Mw (D1)) is 0.95 to 1.05. The ratio (Mw(Ar2)) of the weight average molecular weight (Mw(Ar2)) of the aromatic vinyl polymer block Ar2 of the block copolymer A to the weight average molecular weight (Mw(Ar1)) of the aromatic vinyl polymer block Ar1. )/Mw(Ar1)) is in the range of 1 to 7, the electrical insulating tape according to claim 2 or 3. The electrical insulating tape according to any one of claims 2 to 4, wherein the block copolymer B is prepared together with the block copolymer A when the block copolymer A is prepared. The hydrogenated hydrocarbon resin is
1,3-pentadiene monomer unit 30% by mass to 75% by mass,
20% by mass to 50% by mass of alicyclic monoolefin monomer units having 4 to 6 carbon atoms,
5% to 25% by mass of acyclic monoolefin monomer units having 4 to 8 carbon atoms,
It is obtained by hydrogenating a hydrocarbon resin containing 0% to 10% by mass of alicyclic diolefin monomer units and 0% to 30% by mass of aromatic monoolefin monomer units. The electrical insulating tape according to any one of claims 1 to 5. The hydrogenated hydrocarbon resin is
The hydrogenation rate of the olefin is 10% to 80%,
In the case of containing an aromatic monomer unit, the hydrogenation rate of the aromatic ring is 1% to 30%,
The weight average molecular weight (Mw) is 1,000 to 3,500,
Z average molecular weight (Mz) is 2,000 to 7,000,
The ratio of Z average molecular weight to weight average molecular weight (Mz/Mw) is 1.5 to 2.5,
The softening point is 50°C or higher,
The electrical insulating tape according to claim 6, wherein the Gardner color number of the 50% by mass toluene solution is 3 or less. The electrical insulating tape according to any one of claims 1 to 7, further comprising a softener. The content rate of the block copolymer composition is 10% by mass to 70% by mass, the content rate of the hydrogenated hydrocarbon resin is 20% by mass to 80% by mass, and the content rate of the softener is 0.1% by mass to The electrical insulating tape according to claim 8, which has a content of 30% by mass. The electrical insulating tape according to any one of claims 1 to 9, wherein the proportion of aromatic vinyl monomer units in the entire block copolymer composition is 10% by mass to 50% by mass.