JP5602000B2 - Copolymer for adhesive, method for producing the same, and composition for adhesive - Google Patents

Description

  The present invention relates to a copolymer for adhesives, a method for producing the same, and an adhesive composition.

In recent years, hot-melt adhesives have been widely used from the viewpoints of energy saving, resource saving, environmental load reduction, etc., and monovinyl aromatic as a base polymer for hot-melt adhesives. Block copolymers (SBS, SIS, etc.) comprising a compound and a conjugated diene compound are widely used.
However, with respect to the adhesive using the block copolymer as described above, that is, the adhesive composition, the balance of holding power, tack, adhesive strength, and low melt viscosity performance of the composition is still unsatisfactory. Sufficient and these improvements are desired.
For example, in Patent Document 1, as a composition comprising a block copolymer, a tackifier resin, and a softening agent, the diblock amount of the block copolymer is 50% by weight or more and 90% by weight or less, and in the block copolymer. An adhesive composition having a monovinyl aromatic compound content of more than 40% by weight and 50% by weight or less is disclosed.

JP 2004-238548 A

However, the above-mentioned conventionally proposed adhesive composition still has room for improvement from the viewpoint of sufficiently satisfying all the characteristics of holding power, tack, adhesive strength, and low melt viscosity. There is.
Therefore, in the present invention, in view of the problems of the prior art, an adhesive composition having an excellent balance of holding power, tack, and adhesive force, and having a low melt viscosity, and a copolymer for adhesives constituting the composition. The purpose is to provide.

As a result of intensive studies in order to solve the above-mentioned problems of the prior art, the present inventors have a vinyl aromatic monomer unit and a conjugated diene monomer unit, and are obtained by gel permeation chromatography (GPC). In the measured molecular weight measurement in terms of polystyrene (PS), it was found that the above problems can be solved by using a copolymer having a predetermined number of peaks and a molecular weight distribution of a predetermined value or more. It came to be completed.
That is, the present invention is as follows.

[1]
Mainly composed of vinyl aromatic monomer unit (a) and conjugated diene monomer unit (b),
One or more polymer blocks mainly composed of vinyl aromatic monomer units, mainly conjugated diene units
Containing one or more polymer blocks to form a body,
Copolymer for adhesives satisfying the following conditions (1) to (4).
(1) The content of the vinyl aromatic monomer unit is 20 to 60% by mass.
(2) The hydrogenation rate in the conjugated diene monomer unit is 10 to 50%.
(3) It has two or more peaks in polystyrene (PS) conversion molecular weight measurement measured by gel permeation chromatography (GPC).
(4) The molecular weight distribution (= weight average molecular weight (Mw) / number average molecular weight (Mn)) is 1.2 or more.
[2]
The copolymer for adhesives according to [1], wherein the molecular weight distribution is 1.4 or more.
[3]
The proportion of the component having a molecular weight of polystyrene equivalent of 100,000 or more is 5% to 40% [1] or [
[2] Copolymer for adhesives according to [2].
[4]
The proportion of components having a polystyrene-equivalent molecular weight of 50,000 or less is 20% to 80% [1] to [
[3] The adhesive adhesive copolymer according to any one of [3].
[5]
[1] to [1] containing one or more polymer blocks mainly composed of vinyl aromatic monomer units
4] The copolymer for adhesives according to any one of 4).
[6]
The method for producing a copolymer for adhesives according to any one of [1] to [5],
Adding organic lithium to the polyvinyl aromatic compound in a range of 0.01 to 1.0 in terms of polyvinyl aromatic compound amount (mol) / lithium amount (mol);
Adding a monomer constituting the adhesive adhesive copolymer and polymerizing;
A step of hydrogenation;
The manufacturing method of the copolymer for adhesive agents which performs these sequentially.
[7]
The method for producing a copolymer for adhesives according to any one of [1] to [5],
A polyvinyl aromatic compound;
The polyvinyl aromatic compound amount (mol) / lithium amount (mol) is 0.01 to 1.0.
An amount of organolithium in the range of
A polar compound;
Mixing in random order;
Adding a monomer constituting the adhesive adhesive copolymer and polymerizing;
A step of hydrogenation;
The manufacturing method of the copolymer for adhesive agents which performs these sequentially.
[8]
The method for producing a copolymer for adhesives according to any one of [1] to [5],
Adding organic lithium;
Polyvinyl aromatic compound is converted into polyvinyl aromatic compound amount (mol) / lithium amount (mo
adding 1) so that the amount corresponds to a range of 0.01 to 1.0;
Conjugated diene compound has a conjugated diene compound amount (mol) / lithium amount (mol) of 1-1.
Adding to an amount corresponding to a range of 00;
Adding a polar compound;
In random order,
Thereafter, a monomer constituting the adhesive adhesive copolymer is added and polymerized ;
A step of hydrogenation;
The manufacturing method of the copolymer for adhesive agents which performs these sequentially .
[9]
In the step of adding and polymerizing the monomer constituting the adhesive adhesive copolymer, after adding the monomer constituting the adhesive adhesive copolymer, the polyfunctional coupling agent is further added. The method for producing a copolymer for adhesives according to any one of [6] to [8] to be added.
[10]
[10] Copolymer for adhesives according to any one of [1] to [5] ,
10-80% by weight of tackifying resin,
0-70% by mass of softener,
Containing,
And the adhesive composition whose total amount of the said copolymer for adhesives, the said tackifying resin, and the said softener is 75 mass% or more.
[11]
[1] to [5] copolymer for adhesives according to any one of 10 to 100% by mass,
0-60 mass% of tackifying resin,
0-50 mass% of softener,
Containing,
And the adhesive agent composition for elastic members whose total amount of the said copolymer for adhesive agents, the said tackifying resin, and the said softener is 75 mass% or more.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in the performance balance of holding power, tack, and adhesive force, and melt viscosity is practically low enough for an adhesive composition and the adhesive which comprises the said viscosity adhesive composition. Copolymers can be provided.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail.
In addition, this invention is not restrict | limited to the following embodiment, A various deformation | transformation can be implemented within the range of the summary.

[Copolymer for adhesives]
The adhesive adhesive copolymer of this embodiment is
It is a copolymer for adhesives mainly composed of a vinyl aromatic monomer unit (a) and a conjugated diene monomer unit (b) and satisfying the following conditions (1) to (4).
(1) The content of the vinyl aromatic monomer unit is 20 to 60% by mass.
(2) The hydrogenation rate in the conjugated diene monomer unit is 10 to 50%.
(3) It has two or more peaks in polystyrene (PS) conversion molecular weight measurement measured by gel permeation chromatography (GPC).
(4) The molecular weight distribution (= weight average molecular weight (Mw) / number average molecular weight (Mn)) is 1.2 or more.

In addition, in this specification, the naming of each monomer unit constituting the copolymer for adhesives follows the naming of the monomer from which the monomer unit is derived.
For example, “vinyl aromatic monomer unit” means a structural unit of a polymer resulting from polymerization of a vinyl aromatic compound as a monomer, and the structure thereof is substituted ethylene derived from a substituted vinyl group. It is a molecular structure in which the two carbons of the group are binding sites.
The term “conjugated diene monomer unit” means a structural unit of a polymer produced as a result of polymerizing a monomer, conjugated diene, and its structure is the same as that of an olefin derived from a conjugated diene monomer. It is a molecular structure in which two carbons are binding sites.
In the present specification, “mainly” means that the content is 60% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and 95% by mass. More preferably, it is the above.

Examples of the vinyl aromatic monomer unit (a) constituting the copolymer for adhesives according to this embodiment include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, and 1,1-diphenyl. Examples thereof include vinyl aromatic compounds such as ethylene, N, N-dimethyl-p-aminoethylstyrene, and N, N-diethyl-p-aminoethylstyrene.
These may use only 1 type and may use 2 or more types together. Styrene is preferred from the economical viewpoint.

The following conjugated diene can be used as the conjugated diene monomer unit (b) constituting the adhesive / adhesive copolymer of the present embodiment.
Conjugated dienes are diolefins having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene. 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, etc., and 1,3-butadiene and isoprene are preferred.
These conjugated dienes may be used alone or in combination of two or more.
From the viewpoint of mechanical strength, it is more preferable that the main component is 1,3-butadiene.
Furthermore, the 1,3-butadiene content in the conjugated diene is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more.

The content of the vinyl aromatic monomer unit in the adhesive adhesive copolymer of the present embodiment is 20% by mass or more from the viewpoint of the holding power of the adhesive performance, and is 30% by mass or more. Is preferable, and 35 mass% or more is more preferable.
Further, from the viewpoint of tackiness of the adhesive performance and low melt viscosity of the adhesive composition, the content of the vinyl aromatic monomer unit is 60% by mass or less, and preferably 55% by mass or less.

In the adhesive adhesive copolymer of this embodiment, 10% or more of the total unsaturated groups derived from the conjugated diene monomer are hydrogenated from the viewpoint of the holding power of the adhesive performance. It shall be. The hydrogenation rate is preferably 15% or more.
Further, from the viewpoint of obtaining a low melt viscosity in the adhesive composition, the hydrogenation rate is 50% or less, and preferably 45% or less.
From the viewpoint of obtaining a low melt viscosity in the adhesive composition, the content of vinyl bond units in the total conjugated diene units before hydrogenation is preferably 60% or less, and more preferably 50% or less.

Further, from the viewpoint of tack, the content of vinyl bond units in the copolymer for adhesives of this embodiment is preferably 10% or more, and more preferably 15% or more.
In addition, “content of vinyl bond unit” refers to 1,2-bond, 3,4-bond, and 1,4-bond linkages of conjugated dienes before hydrogenation, It is the ratio of those incorporated by 2-bond and 3,4-bond.
About content of a vinyl bond unit, it can measure by the method shown in the Example mentioned later.

The copolymer for an adhesive of the present embodiment is a polymer block mainly composed of a vinyl aromatic monomer from the viewpoint of realizing high holding power and high adhesive strength and ensuring low viscosity of the composition. It is preferable to contain 1 or more.
The “polymer block mainly composed of a vinyl aromatic monomer” refers to a polymer block containing 60% by mass or more of a vinyl aromatic monomer unit.
The content of the polymer block mainly composed of a vinyl aromatic monomer unit in the adhesive adhesive copolymer of the present embodiment realizes a high holding power and a high adhesive strength, and an adhesive composition From the viewpoint of practically sufficiently reducing the melt viscosity, it is preferably 20% by mass or more, and from the viewpoint of obtaining a high tack, it is preferably 60% by mass or less. Moreover, the range of 30 to 55 mass% is more preferable, and the range of 35 to 55 mass% is more preferable.
The content of the polymer block mainly composed of vinyl aromatic monomer units in the adhesive adhesive copolymer of the present embodiment is determined by the method described in the examples described later.

The distribution of the vinyl aromatic monomer in the adhesive adhesive block of the present embodiment or the block in the adhesive adhesive copolymer is uniform, tapered, or stepwise. Also good.
Further, a plurality of portions where vinyl aromatics are uniformly distributed and / or a portion where they are distributed in a tapered shape may coexist. A plurality of segments having different vinyl aromatic contents may coexist.

From the viewpoint of ensuring a higher holding power and a low melt viscosity of the composition, the adhesive adhesive copolymer of the present embodiment has one or more polymer blocks mainly composed of vinyl aromatic monomer units, It is preferable to contain one or more polymer blocks mainly composed of conjugated diene monomer units.
The “polymer block mainly composed of conjugated diene monomer units” means a polymer block containing 60% by mass or more of conjugated diene monomer units. The content of the conjugated diene unit is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more.

In addition, in the adhesive adhesive copolymer of the present embodiment, when there are a plurality of polymer blocks, the structures such as molecular weight and composition may be the same or different. Good.
The distribution of the vinyl unit of the conjugated diene unit of the polymer block is not particularly limited.

The copolymer for adhesives of this embodiment is a gel permeation chromatography (GPC) from the viewpoint of realizing high holding power, high tack, high adhesive strength, and low melt viscosity in the adhesive composition. In the measured polystyrene (PS) conversion molecular weight measurement, it has two or more peaks, and the molecular weight distribution (= weight average molecular weight (Mw) / number average molecular weight (Mn)) is 1.2 or more. To do.
The molecular weight distribution (Mw / Mn) is more preferably 1.4 or more, and further preferably 1.6 or more.
Moreover, in the said measurement, it is more preferable to have three or more peaks.

In the copolymer for adhesives of this embodiment, from the viewpoint of obtaining high holding power and high adhesive strength, the ratio of components having a polystyrene (PS) equivalent molecular weight of 100,000 or more is preferably 5% or more, which will be described later. In view of obtaining a low melt viscosity in the adhesive composition of this embodiment, it is preferably 40% or less.
Moreover, the PS conversion molecular weight shall be the said range, and the (cramming) finish property after the superposition | polymerization process of the copolymer for adhesive agents will become favorable.
The proportion of the component having a PS converted molecular weight of 100,000 or more is more preferably 10% or more and 25% or less, and further preferably 12% or more and 20% or less.

Moreover, in the adhesive composition of this embodiment mentioned later, from the viewpoint of ensuring high tack and low melt viscosity, the copolymer for adhesive of this embodiment has a PS-converted molecular weight of 50,000 or less. The component ratio is preferably 20% or more, and preferably 80% or less from the viewpoint of the high holding power of the adhesive composition.
The proportion of the component having a PS-converted molecular weight of 50,000 or less in the copolymer for adhesives of this embodiment is more preferably from 30% to 70%, and even more preferably from 40% to 65%.

  The number average molecular weight (Mn), the weight average molecular weight (Mw), the molecular weight distribution (Mw / Mn), the ratio (%) where Mn is 50,000 or less, the ratio (%) where Mn is 100,000 or more, and the molecular weight distribution The number of peaks is obtained according to the measurement conditions of gel permeation chromatography (GPC) shown in the examples described later.

  In the copolymer for adhesives of this embodiment, the weight average molecular weight is preferably 60,000 or more from the viewpoint of obtaining practically high holding power and high adhesive strength, and has low melt viscosity and high tack. From the viewpoint of obtaining, it is preferably 1 million or less, more preferably 70,000 or more and 500,000 or less, and further preferably 80,000 or more and 300,000 or less.

  Although the copolymer for adhesives of this embodiment is not specifically limited about MFR (200 degreeC, 5 kg), From a viewpoint of obtaining a low melt viscosity and a high tack, it is 0.1 g / 10min or more. From the viewpoint of obtaining high holding power and high adhesive strength, it is preferably 150 g / 10 min or less, more preferably 0.5 g / 10 min to 80 g / 10 min, and more preferably 1 g / 10. More preferably, it is not less than 50 minutes and not more than 50 g / 10 minutes.

[Method for producing copolymer for adhesive]
(First manufacturing method)
As the 1st manufacturing method of the copolymer for adhesive agents of this embodiment, an organic lithium is added to a polyvinyl aromatic compound, Polyvinyl aromatic compound amount (mol) / lithium amount (mol) is 0.01-. A method of sequentially performing a step of adding so as to be in the range of 1.0 and a step of adding and polymerizing a monomer constituting the copolymer for adhesives can be mentioned.

(Second manufacturing method)
As a 2nd manufacturing method of the copolymer for adhesive agents of this embodiment, an organic lithium is added to a polyvinyl aromatic compound, Polyvinyl aromatic compound amount (mol) / lithium amount (mol) is 0.01-. The step of adding the monomer constituting the copolymer for adhesives after the step of adding to the range of 1.0 and the step of adding the polar compound are performed in random order, and then polymerizing The method of performing is mentioned.

(Third production method)
As a third production method of the adhesive adhesive copolymer of the present embodiment, the step of adding organolithium and the polyvinyl aromatic compound are as follows: polyvinyl aromatic compound amount (mol) / lithium amount (mol) A step of adding the conjugated diene compound to an amount corresponding to a range of 0.01 to 1.0 and an amount corresponding to a conjugated diene compound amount (mol) / lithium amount (mol) of 1 to 100 The method of performing the step of adding the polar compound and the step of adding the polar compound in random order, and then the step of adding and polymerizing the monomer constituting the copolymer for adhesives is given. It is done.

  From the viewpoint of realizing the manufacturability of the copolymer for adhesives, the high holding power of the adhesive composition using the copolymer for adhesives, the high tack, the high adhesive force, and the low melt viscosity, A step of adding organolithium to the polyvinyl aromatic compound, which is the first production method, so that the amount of polyvinyl aromatic compound (mol) / the amount of lithium (mol) is in the range of 0.01 to 1.0; A method of sequentially performing the steps of adding and polymerizing a monomer constituting the copolymer for adhesives is preferable.

  More preferably, after adding the polar compound to the polyvinyl aromatic compound, the organic lithium is added so that the polyvinyl aromatic compound amount (mol) / lithium amount (mol) is in the range of 0.01 to 1.0. Thereafter, a method of polymerizing by adding a monomer constituting the copolymer for adhesives is mentioned.

  More preferably, a polyvinyl aromatic compound, a conjugated diene compound, and a polar compound are added in random order, and then organic lithium is added in an amount of polyvinyl aromatic compound (mol) / lithium amount (mol) of 0.01 to 1. It is in the range of 0 and the amount of conjugated diene compound (mol) / lithium amount (mol) is in the range of 1 to 100, that is, the ratio to the amount of polyvinyl aromatic compound and the ratio to the amount of conjugated diene compound With respect to the above, there may be mentioned a method in which the above ranges are added in an amount satisfying all, and then a monomer constituting the adhesive adhesive copolymer is added for polymerization.

In the method for producing a copolymer for adhesives according to this embodiment, the amount of the conjugated diene compound is preferably such that the amount of conjugated diene compound (mol) / lithium amount (mol) is in the range of 5-30. From the viewpoint of mechanical strength, the conjugated diene is preferably butadiene.
Moreover, in the manufacturing method of the copolymer for adhesive agents of this embodiment, the range of the said polyvinyl aromatic compound amount (mol) / lithium amount (mol) shall be the range of 0.05-0.4. Is preferable, and the range of 0.1 to 0.3 is more preferable.

  As the organic lithium, a conventionally known material can be used as long as it is used for anionic polymerization. For example, monoorganolithium compounds such as n-butyllithium, sec-butyllithium, tert-butyllithium, n-propyllithium, iso-propyllithium, benzyllithium, 1,4-dilithiobutane, 1,5-dilithiopentane, 1,6-dilithiohexane, 1,10-dilithiodecane, 1,1-dilithiodiphenylene, dilithiopolybutadiene, dilithiopolyisoprene, 1,4-dilithiobenzene, 1,2-dilithio-1,2- Polyfunctional organolithium compounds such as diphenylethane, 1,4-dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-trilithio-2,4,6-triethylbenzene Preferably, mono-organolithiation of n-butyllithium and sec-butyllithium Object is used.

Polyvinyl aromatic compounds include, for example, o, m and p-divinylbenzene, o, m and p-diisopropenylbenzene, 1,2,4-trivinylbenzene, 1,2-vinyl-3,4-dimethylbenzene. 1,3-divinylnaphthalene, 1,3,5-trivinylnaphthalene, 2,4-divinylbiphenyl, 3,5,4′-trivinylbiphenyl, 1,2-divinyl-3,4-dimethylbenzene, , 5,6-trivinyl-3,7-diethylnaphthalene and the like. These may be used alone or in combination of two or more.
Among these, divinyl benzene and diisopropenyl benzene are particularly preferable, and a mixture of these o-, m-, and p-isomers may be used.
For industrial use, it is economically advantageous to use a mixture of these isomers.

In the second and third production methods of the adhesive adhesive copolymer of the present embodiment, the polar compound is an object of improving the copolymerizability of the vinyl aromatic monomer unit and the conjugated diene monomer unit. In addition, it is added as a vinylating agent for controlling the microstructure of the conjugated diene part, and for the purpose of improving the polymerization rate.
Examples of the polar compound include ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, and 2,2-bis (2-oxolanyl) propane; Tertiary amine compounds such as methylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; alkali metal alkoxides such as potassium tert-amylate, potassium tert-butylate, sodium tert-butylate, sodium amylate Compound: Examples include phosphine compounds such as triphenylphosphine.
These polar compounds may be used alone or in combination of two or more.

The conjugated diene compound used in the third method for producing the adhesive adhesive copolymer of the present embodiment is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene and 2-methyl. -1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, etc. 3-Butadiene and isoprene are preferred.
These conjugated diene compounds may be used alone or in combination of two or more.
From the viewpoint of mechanical strength, it is more preferable that the main component is 1,3-butadiene.
Furthermore, the 1,3-butadiene content in the conjugated diene compound is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more.

In the adhesive composition of the present embodiment to be described later, from the viewpoint of achieving a good balance of performance of high holding power, high tack, high adhesive force, and low melt viscosity, for the adhesive of the present embodiment. In the method for producing a copolymer, it is more preferable to add a polyfunctional coupling agent after the monomer is added.
At this time, the addition timing of the polyfunctional coupling agent is preferably after the addition of 90% by mass or more of the total amount of monomers, and more preferably after the addition of 99% by mass or more.
Multifunctional coupling agents include silicon tetrachloride, tin tetrachloride, epoxidized soybean oil, polyhalogenated hydrocarbon compounds, carboxylic acid ester compounds, polyvinyl compounds, bisphenol-type epoxy compounds, alkoxysilane compounds, halogenated silane compounds, Examples include ester compounds. These may be used alone or in combination with two or more.
From the viewpoints of the above performance and economy, the polyfunctional coupling agent is preferably a tetrafunctional compound.

  In the method for producing the adhesive adhesive copolymer of the present embodiment described above, addition of polyvinyl aromatic compound, addition of organic lithium, addition of polar compound, addition of monomer for polymer, multifunctional coupling Although the addition order of each agent is shown in the required order, other steps may be performed simultaneously or in between as long as the addition order is followed.

Further, in the above-described method for producing the adhesive adhesive copolymer of the present embodiment, the polymer monomer, the polyvinyl aromatic compound, the organic lithium, or the like may be diluted in a polymerization solvent and added. .
In this case, it is not necessary to first add a polymerization solvent to the polymerization vessel as necessary.
For example, when adding a polyvinyl aromatic compound, organolithium, and a polar compound (in no particular order), if necessary, a monomer (not the total amount of the monomer) constituting the copolymer for adhesives It may be added.
A hydrocarbon solvent is used as a solvent used in the polymerization reaction.
Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as butane, pentane, hexane, and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene, and xylene.

The polymerization method of the adhesive adhesive copolymer is not particularly limited, and examples thereof include coordination polymerization, anionic polymerization, and cationic polymerization.
From the viewpoint of easy control of the structure, anionic polymerization is preferred.
As a method for producing an anionic polymerization block copolymer, a known method can be applied. For example, Japanese Patent Publication No. 36-19286, Japanese Patent Publication No. 43-17879, Japanese Patent Publication No. 46-32415, Japanese Patent Publication No. 49-36957, Japanese Patent Publication No. 48-2423, Japanese Patent Publication No. 48-4106, Examples thereof include the methods described in JP-B-56-28925, JP-A-59-166518, JP-A-60-186777, and the like.

The adhesive copolymer of this embodiment may be a hydrogenated product. In such a case, it is preferable to hydrogenate the vinyl aromatic monomer and the conjugated diene monomer after polymerization.
Examples of the hydrogenation method include a method of supplying hydrogen in the presence of a hydrogenation catalyst and hydrogenating an unsaturated portion.
The hydrogenation catalyst is not particularly limited, and a conventionally known (1) supported heterogeneous system in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like. (2) so-called Ziegler-type hydrogenation catalysts using (2) organic acid salts such as Ni, Co, Fe, Cr, transition metal salts such as acetylacetone salts and reducing agents such as organic aluminum, and (3) Ti Homogeneous hydrogenation catalysts such as so-called organometallic complexes such as organometallic compounds such as Ru, Rh and Zr are used.
Specifically, JP-B-42-8704, JP-B-43-6636, JP-B-63-4841, JP-B-1-37970, JP-B-1-53851, JP-B-2-9041 And hydrogenation catalysts described in Japanese Patent Publication No.

Furthermore, although the manufacturing method of the copolymer for adhesive agents of this embodiment mentioned above can be implemented using a single polymerization pot, for example, it is not limited to this example, You may perform a part of process using another superposition | polymerization kettle.
Specifically, cyclohexane, conjugated diene (butadiene is preferable), and a polyvinyl aromatic compound are added as a solvent, and then n-butyllithium is added and reacted at 70 ° C. for 1 hour (Preparation A).
The divinylbenzene used for the preparation of the catalyst contains 56% by mass of an isomer mixture (m-divinylbenzene = 40% by mass, p-divinylbenzene = 16% by mass), with the remainder consisting of ethylvinylbenzene and diethylbenzene. Use.
In another polymerization kettle, add the reaction solvent, monomer and polar solvent, then add the required amount of the above preparation A, polymerize the monomer, and after the polymerization is complete, add the polyfunctional coupling agent. Then, the method of hydrogenating is mentioned.
From the economical point of view, it is preferable that the method for producing the adhesive adhesive copolymer of the present embodiment is carried out using a single polymerization kettle.
In the above, the polymerization kettle is not particularly limited as long as it has a volume having a capacity for accommodating a monomer or the like necessary for polymerization. Any of these can be used.

  The polymerization temperature of the anionic polymerization of the adhesive adhesive copolymer of this embodiment is preferably in the range of 10 ° C to 130 ° C, more preferably 35 ° C to 100 ° C.

The copolymer for adhesives of this embodiment obtained by the manufacturing method mentioned above may have a polar group containing atomic group.
Examples of polar groups include hydroxyl groups, carboxyl groups, carbonyl groups, thiocarbonyl groups, acid halide groups, acid anhydride groups, thiocarboxylic acid groups, aldehyde groups, thioaldehyde groups, carboxylic acid ester groups, amide groups, and sulfonic acids. Group, sulfonate group, phosphate group, phosphate group, amino group, imino group, nitrile group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, isothiocyanate group, silicon halide Group, alkoxysilicon group, tin halide group, boronic acid group, boron-containing group, boronate group, alkoxytin group, phenyltin group and the like.
The location of the compound having a polar group-containing atomic group in the copolymer for adhesives according to the present embodiment is not particularly limited, and is molecularly terminated in the molecular chain (polymerization initiation terminal or polymerization termination terminal) or grafted. May be.
In addition, the concentration distribution of the functional group in the adhesive adhesive copolymer of the present embodiment is not particularly limited.
Here, for details of the graft-modifying method, reference can be made to, for example, JP-A No. 62-79211.
You may make it react with the compound which has a polar group containing atomic group further in the polar group containing group and polyfunctional coupling agent residue of a polymerization termination terminal part.

[Adhesive composition]
Although the copolymer for an adhesive of the present embodiment can be used alone as an adhesive material, it can be used in combination with a tackifier resin and a softener from the viewpoint of economy, high tack, and low melt viscosity. An adhesive composition is preferred.
<Tackifying resin>
A variety of tackifying resins are selected depending on the application and required performance.
For example, coumarone resin, aromatic hydrocarbon resin, rosin resin, terpene resin, petroleum resin, phenol resin, terpene-phenol resin, alicyclic hydrocarbon resin, hydrogenated terpene resin, hydrogenated Known tackifying resins such as rosin resins can be used, and these tackifying resins may be used alone or in combination of two or more.
<Softener>
The kind of softener is not limited, and known paraffinic and naphthenic process oils and mixed oils thereof can be used.

The adhesive composition of this embodiment may use the tackifier resin and the softener in combination, or may contain only one of these.
The ratio of the adhesive copolymer, the tackifier resin, and the softening agent includes a high holding power, a high tack, a high adhesive strength, and a low melt viscosity so that the balance of all the performances is good. Adhesive copolymer 10 to 80% by mass, tackifier resin 10 to 80% by mass, softener 0 to 70% by mass, and coadhesive for adhesive in the adhesive composition The total content of coalesced, tackifying resin, and softener is preferably 75% by mass or more.
In addition, it is more preferable that they are 30-60 mass% of adhesive copolymers, 30-60 mass% of tackifying resin, and 20-50 mass% of softening agents.

Furthermore, in the case of an adhesive composition that also has an elastic member used for gathered parts of paper diapers, etc., high holding power, high tack, high adhesive strength, low melt viscosity, low tensile permanent strain, In order to achieve a good balance of all the performances, the adhesive polymer, the tackifier resin, and the softening ratio are 10 to 100% by mass of the adhesive adhesive copolymer, the tackifier resin 0 to 60 mass% and softener 0 to 50 mass%, and the total content of the adhesive adhesive copolymer, tackifying resin, and softener in the adhesive composition is 75 mass% or more. It is preferable that
In addition, it is more preferable that they are 20-90 mass% of adhesive copolymers, 10-50 mass% of tackifying resin, and 5-40 mass% of softening agents, 30-80 mass% of adhesive copolymers, and adhesion More preferably, it is 20-40 mass% of imparting resin and 10-30 mass% of softening agents.

  Moreover, in the adhesive composition for elastic members, the tensile permanent strain is preferably 30% or less, more preferably 20% or less, from the viewpoint of stretch performance.

<Antioxidant>
In the adhesive composition of this embodiment, an antioxidant can be added if necessary, and further improvement in thermal stability and improvement in heat discoloration can be achieved.
As the antioxidant, phosphorus compounds such as hindered phenol compound phosphites are preferable.
Only one type of antioxidant may be used alone, or two or more types may be mixed and used.
Although these addition amounts are arbitrary according to a use, 5 mass% or less of an adhesive composition is preferable.

<Light stabilizer>
In the adhesive composition of this embodiment, a light stabilizer can also be used.
As the light stabilizer, for example, benzotriazole compounds, hindered amine compounds, benzophenone compounds, and the like are preferable.
Light resistance can be further improved by including the benzotriazole compound, hindered amine compound, benzophenone compound, and the like in the adhesive composition.

<Other additives>
In addition to the stabilizer, the adhesive composition of the present embodiment includes, as other additives, pigments such as bengara and titanium dioxide; waxes such as paraffin wax, microcrystalline wax, and low molecular weight polyethylene wax; Polyolefin or low molecular weight vinyl aromatic thermoplastic resins such as regular polyolefin and ethylene-ethyl acrylate copolymer; natural rubber; polyisoprene rubber, polybutadiene rubber, styrene-butadiene rubber, ethylene-propylene rubber, chloroprene rubber, acrylic Rubber, isoprene-isobutylene rubber, polypentenamer rubber, styrene-butadiene block copolymer other than the copolymer for adhesives of this embodiment, styrene-isoprene block copolymer, hydrogenated styrene-butadiene system Block copolymer, Fluorinated styrene - may be added to synthetic rubber such as isoprene block copolymer.

[Method for producing adhesive composition]
The adhesive composition of the present embodiment can be produced by appropriately selecting and mixing the above-mentioned copolymer for adhesives, a tackifier resin, and a softener by a known method. it can.
For example, it can be produced by uniformly mixing a co-adhesive copolymer, a tackifier, and a softener under heating conditions using a mixer, a kneader, or the like.

[Use]
The co-adhesive copolymer and co-adhesive composition of the present embodiment are an adhesive, non-stretch sheet and co-adhesive composition having the stretch performance of various sanitary products such as disposable diapers and sanitary products. It can be used for stretchable sheets laminated with various materials, various adhesive tapes / labels, pressure-sensitive thin plates, pressure-sensitive sheets, back paste for fixing various lightweight plastic molded products, back paste for fixing carpets, back paste for fixing tiles, and the like.

  Hereinafter, the present invention will be described in detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples.

Evaluation methods and measurement methods used in Examples and Comparative Examples are shown below.
I. Composition of Adhesive Copolymer (A) and Structure Evaluation Method (I-1) Styrene Content, Vinyl Bond Amount of Conjugated Diene, Hydrogenation Rate of Double Bond Based on Conjugated Diene Specifically, Adhesion Each amount of styrene unit, 1,4-bond unit of butadiene, 1,2-bond unit, ethylene unit, or butylene unit in the copolymer for adhering was measured by nuclear magnetic resonance spectrum analysis (NMR) as follows. It measured on condition of this.
Measuring instrument: JNM-LA400 (manufactured by JEOL)
Solvent: Deuterated chloroform Measurement sample: Sample taken before and after hydrogenation of polymer Sample concentration: 50 mg / mL
Observation frequency: 400 MHz
Chemical shift criteria: TMS (tetramethylsilane)
Pulse delay: 2.904 seconds Number of scans: 64 times Pulse width: 45 °
Measurement temperature: 26 ° C

(I-2) Content of polymer block mainly composed of vinyl aromatic monomer unit M.M. Kolthoff, et al. , J. et al. Polym. Sci. , 1946, Vol. 1, p. 429, and measured by the osmium tetroxide method.
Measurement sample: A polymer obtained by polymerizing monomers and extracted in the previous stage of hydrogenation Polymer decomposition solution: A solution in which 0.1 g of osmium acid was dissolved in 125 mL of tertiary butanol

(I-3) Number average molecular weight (Mn), weight average molecular weight (Mw), molecular weight distribution (Mw / Mn), Mn is 50,000 or less (%), Mn is 300,000 or more (%), molecular weight Number of distribution peaks Measured by gel permeation chromatography (GPC) under the following conditions, the distribution curve obtained has a polystyrene (PS) equivalent molecular weight of 10,000 or more and a PS equivalent molecular weight of 10,000 or more. The range up to a molecular weight corresponding to 99% with respect to the total area value (mV) was calculated and obtained as a molecular weight in terms of polystyrene (PS).
Measuring device: GPC: HLC-8220 (manufactured by TOSOH, trade name)
Column: TSKgelGMHXL SuperH5000: 1 and SuperH4000: 2 (trade name, manufactured by TOSOH)
Solvent: Tetrahydrofuran Temperature: 40 ° C
Sample for calibration curve: commercially available standard polystyrene (manufactured by TOSOH), 10-point measurement. When the polymer was not dissolved due to high crystallinity or the like, the measurement was performed by changing the solvent or increasing the temperature.
The ratio (%) where Mn was 50,000 or less and the ratio (%) where Mn was 100,000 or more were determined from the area of the integral value of the area value (mV) of the distribution curve.
The number of peaks of the molecular weight distribution was obtained from the automatic measurement described above.

II. Preparation of hydrogenation catalyst III. The hydrogenation catalyst used for the hydrogenation reaction in the preparation of the adhesive adhesive copolymer described in 1 was prepared by the following method.
Charge 1 liter of dried and purified cyclohexane to a nitrogen-substituted reaction vessel, add 100 mmol of biscyclopentadienyl) titanium dichloride, and add an n-hexane solution containing 200 mmol of trimethylaluminum while stirring thoroughly. The mixture was reacted at room temperature for about 3 days.

III. (A) Preparation of copolymer for adhesive (polymer (polymer 1))
A hydrogenated block copolymer was prepared by the following method using a stirrer having an internal volume of 10 L and a jacketed tank reactor.
A predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 60 ° C., and then 0.35 mol of divinylbenzene was added to 1 mol of n-butyllithium.
Next, the amount of n-butyllithium was added from the bottom of the reactor so that it would be 0.166 parts by mass with respect to 100 parts by mass of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor). did.
After 5 minutes, a cyclohexane solution (monomer concentration: 22% by mass) containing 45 parts by mass of styrene in the first step was supplied as a monomer in about 15 minutes, and the temperature in the reactor was adjusted to 70 ° C.
After stopping the supply, the reaction was carried out for 10 minutes while adjusting the temperature in the reactor to 70 ° C.
Next, a cyclohexane solution containing 55 parts by mass of butadiene in the second step (monomer concentration: 22% by mass) is continuously supplied to the reactor at a constant rate over 60 minutes, and the temperature in the reactor during that period is 70 ° C. The reaction was carried out while adjusting the internal temperature of the reactor to 70 ° C. for 10 minutes after the supply was stopped.
Next, 0.5 mol of ethyl benzoate was added to 1 mol mol of n-butyllithium, and reacted for 5 minutes while adjusting to 70 ° C.
After completion of the polymerization, a cyclohexane solution of methanol was added so that the amount of methanol was 1 equivalent with respect to 1 mol of n-butyllithium to complete the polymerization reaction, thereby obtaining a block copolymer.
When the block copolymer obtained by polymerization was analyzed, the styrene content was 45% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%.
Next, 100 ppm of the above hydrogenation catalyst as titanium per 100 parts by mass of the polymer was added to the obtained block copolymer, a hydrogenation reaction was performed at a hydrogen pressure of 0.7 MPa and a temperature of 65 ° C., and the hydrogen consumption was 40%. The hydrogen supply was stopped.
Then, methanol was added, and then 0.25 part by mass of octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate was added as a stabilizer to 100 parts by mass of the polymer.
The resulting polymer (hydrogenated block copolymer) (Polymer 1) has a hydrogenation rate of 40%, a molecular weight distribution (Mw / Mn) of 1.70, and an area ratio of a number average molecular weight (Mn) of 50,000 or less. The area ratio of 50%, 100,000 or more was 15%, and the number of peaks in the molecular weight distribution was 3.

(Polymer (Polymer 2, Polymer 3))
A predetermined amount of cyclohexane was charged into a reactor and adjusted to a temperature of 70 ° C., and then N, N, N ′, N′-tetramethylethylenediamine was adjusted to 0.50 mol mol with respect to 1 mol mol of n-butyllithium. Of cyclohexane was added, and 0.33 mol of divinylbenzene was added to 1 mol of n-butyllithium.
Next, the amount of n-butyllithium was added from the bottom of the reactor so as to be 0.125 parts by mass with respect to 100 parts by mass of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor). did.
0.65 mol of 25 parts by mass of styrene in the first step and 75 parts by mass of butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium.
Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer prepared by polymerization was analyzed, the styrene content was 25% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 50 mol%. The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and the hydrogen supply was stopped at a hydrogen consumption of 15% (Polymer 3) and the hydrogen supply was stopped at a hydrogen consumption of 40% (Polymer 2). ) Two types of hydrogenated block copolymers were obtained.
The resulting hydrogenated block copolymer has a molecular weight distribution (Mw / Mn) of 1.59, a number average molecular weight (Mn) of 50,000 or less, an area ratio of 38%, an area ratio of 100,000 or more, 18%, and a molecular weight distribution. The peak number of was 3.
The hydrogenation rate of polymer 2 was 40%, and the hydrogenation rate of polymer 3 was 15%.

(Polymer (Polymer 4, Polymer 5))
A predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., and then 0.3 mol of divinylbenzene was added to 1 mol of n-butyllithium.
Next, the amount of n-butyllithium was added from the bottom of the reactor so as to be 0.159 parts by mass with respect to 100 parts by mass of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor). did.
0.47 mol of styrene 55 parts by mass in the first step and 45 parts by mass butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer produced by the polymerization was analyzed, the styrene content was 55% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%.
The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and the hydrogen supply was stopped at a hydrogen consumption of 20% (Polymer 5), and the hydrogen supply was stopped at a hydrogen consumption of 39% (Polymer). 4) Two types of hydrogenated block copolymers were obtained.
The obtained hydrogenated block copolymer has a molecular weight distribution (Mw / Mn) of 1.44, a number average molecular weight (Mn) of 50,000 or less, an area ratio of 55%, an area ratio of 100,000 or more, 13%, and a molecular weight distribution. The peak number of was 3.
The hydrogenation rate of polymer 4 was 39%, and the hydrogenation rate of polymer 5 was 20%.

(Polymer (Polymer 6, Polymer 7))
A predetermined amount of cyclohexane was charged into a reactor and adjusted to a temperature of 70 ° C., and then N, N, N ′, N′-tetramethylethylenediamine was adjusted to 0.50 mol mol with respect to 1 mol mol of n-butyllithium. Of cyclohexane was added, and 0.33 mol of divinylbenzene was added to 1 mol of n-butyllithium.
Next, the amount of n-butyllithium was added from the bottom of the reactor so as to be 0.132 parts by mass with respect to 100 parts by mass of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor). did.
0.65 mol of 18 parts by mass of styrene in the first step and 82 parts by mass of butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer prepared by polymerization was analyzed, the styrene content was 18% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 50 mol%. The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and the hydrogen supply was stopped at a hydrogen consumption of 5% (Polymer 7) and the hydrogen supply was stopped at a hydrogen consumption of 55% (Polymer 6). ) Two types of hydrogenated block copolymers were obtained.
The obtained hydrogenated block copolymer has a molecular weight distribution (Mw / Mn) of 1.57, a number average molecular weight (Mn) of 50,000 or less, an area ratio of 35%, an area ratio of 100,000 or more, 16%, and a molecular weight distribution. The peak number of was 3.
The hydrogenation rate of polymer 6 was 55%, and the hydrogenation rate of polymer 7 was 5%.

(Polymer (Polymer 8, Polymer 9))
A predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., and then 0.28 mol of divinylbenzene was added to 1 mol of n-butyllithium.
Next, the amount of n-butyllithium was added from the bottom of the reactor so as to be 0.13 parts by mass with respect to 100 parts by mass of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor). did.
0.40 mol of 65 parts by mass of styrene at the first step and 35 parts by mass of butadiene at the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer prepared by polymerization was analyzed, the styrene content was 65% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%. The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and the hydrogen supply was stopped when the hydrogen consumption was 5% (polymer 9) and the hydrogen supply was stopped when the hydrogen consumption was 55% (polymer 8). ) Two types of hydrogenated block copolymers were obtained.
The obtained hydrogenated block copolymer has a molecular weight distribution (Mw / Mn) of 1.42, a number average molecular weight (Mn) of 50,000 or less, an area ratio of 60%, and an area ratio of 100,000 or more, 10%, a molecular weight distribution. The peak number of was 3. The hydrogenation rate of polymer 8 was 55%, and the hydrogenation rate of polymer 9 was 5%.

(Polymer (Polymer 10))
After a predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., the amount of n-butyllithium was 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). It added from the bottom part of the reactor so that it might become 0.15 mass part.
0.30 mol of 45 parts by mass of styrene in the first step and 55 parts by mass of butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer produced by the polymerization was analyzed, the styrene content was 45% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%. The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and hydrogen supply was stopped at a hydrogen consumption of 40%. The resulting hydrogenated block copolymer (Polymer 10) has a hydrogenation rate of 40%, a molecular weight distribution (Mw / Mn) of 1.16, and an area ratio of a number average molecular weight (Mn) of 50,000 or less is 56%. The area ratio over 10,000 was 2%, and the number of peaks in the molecular weight distribution was 2.

(Polymer (Polymer 11))
After a predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., the amount of n-butyllithium was 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). It added from the bottom part of the reactor so that it might become 0.13 mass part.
15 parts by mass of styrene at the first step, 70 parts by mass of butadiene at the second step, and 15 parts by mass of styrene at the third step were added. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above. The hydrogenation reaction was not performed, and ethyl benzoate was not added.
When the copolymer produced by the polymerization was analyzed, the styrene content was 30% by mass, and the average vinyl bond content of the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%. The resulting block copolymer (Polymer 11) has a hydrogenation rate of 0%, a molecular weight distribution (Mw / Mn) of 1.09, a number average molecular weight (Mn) of 50,000 or less area ratio of 16%, 100,000 or more. The area ratio was 5%, and the number of peaks in the molecular weight distribution was 1.

(Polymer (Polymer 12))
A predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., and then N, N, N ′, N′-tetramethylethylenediamine was adjusted to 0.30 mol mol with respect to 1 mol mol of n-butyllithium. Of cyclohexane was added.
Next, the amount of n-butyllithium was added from the bottom of the reactor so as to be 0.16 parts by mass with respect to 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). did.
0.40 mol of 30 parts by mass of styrene in the first step and 70 parts by mass of butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer produced by the polymerization was analyzed, the styrene content was 30% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 35 mol%. The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and hydrogen supply was stopped at a hydrogen consumption of 45%. The resulting hydrogenated block copolymer (Polymer 12) had a hydrogenation rate of 45%, a polymer molecular weight distribution (Mw / Mn) of 1.18, and a number average molecular weight (Mn) of 50,000 or less area ratio of 74%. The area ratio of 100,000 or more was 2%, and the number of molecular weight distribution peaks was 2.

(Polymer (Polymer 13))
After a predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., the amount of n-butyllithium was 100 parts by mass of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor). It added from the bottom part of the reactor so that it might become 0.20 mass part.
0.50 mol of 45 parts by mass of styrene in the first step and 55 parts by mass of butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer produced by the polymerization was analyzed, the styrene content was 45% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%.
The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and hydrogen supply was stopped at a hydrogen consumption of 30%.
The resulting hydrogenated block copolymer (Polymer 13) has a hydrogenation rate of 30%, a molecular weight distribution (Mw / Mn) of 1.21, and an area ratio of a number average molecular weight (Mn) of 50,000 or less is 72%. The area ratio of 10,000 or more was 11%, and the number of molecular weight distribution peaks was 2.

(Polymer (Polymer 14))
A predetermined amount of cyclohexane was charged into the reactor and adjusted to a temperature of 70 ° C., and then 1.0 mol of divinylbenzene was added to 1 mol of n-butyllithium.
Next, the amount of n-butyllithium was added from the bottom of the reactor so as to be 0.13 parts by mass with respect to 100 parts by mass of all monomers (the total amount of butadiene monomer and styrene monomer charged into the reactor). did.
0.50 mol of 45 parts by mass of styrene in the first step and 55 parts by mass of butadiene in the second step and ethyl benzoate were added to 1 mol of n-butyllithium. Other conditions were produced by the same method as the production method of the polymer (polymer 1) described above.
When the copolymer produced by the polymerization was analyzed, the styrene content was 45% by mass, and the average vinyl bond content in the butadiene portion (corresponding to the average vinyl bond content in all conjugated diene units) was 13 mol%.
The obtained block copolymer was subjected to a hydrogenation reaction under the above conditions, and hydrogen supply was stopped at a hydrogen consumption of 30%. The resulting hydrogenated block copolymer (Polymer 14) has a hydrogenation rate of 30%, a molecular weight distribution (Mw / Mn) of 1.45, a number average molecular weight (Mn) of 50,000 or less, an area ratio of 28%, 10 The area ratio of 10,000 or more was 35%, and the number of peaks in the molecular weight distribution was 3.

IV. Production of adhesive composition [Examples 1-7], [Comparative Examples 1-7]
The polymer (polymer) obtained in III. Above, a tackifier resin, a softener, and an antioxidant are mixed in a proportion of 30 parts by mass, 50 parts by mass, 20 parts by mass, and 0.3 parts by mass, respectively. The adhesive composition of Examples 1-7 and Comparative Examples 1-7 was produced.
Tackifying resin: Alcon M100 (Arakawa Chemical)
Softener: Diana Process Oil PW-90 (made by Idemitsu Kosan)
Antioxidant: 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Ciba Japan)

V. Evaluation method of adhesive composition The characteristics of the adhesive composition were measured by the following method.
In addition, the following tack, adhesive force, and holding force are measured by dissolving the adhesive composition in toluene, and using a 30% by weight solution on a 50 μm thick polyester film with an applicator, the thickness of the adhesive layer is An adhesive tape coated so as to be 50 μm was used.

(1) Melt Viscosity The melt viscosity at 140 ° C. of the adhesive composition was measured using a Brookfield viscometer.
The melt viscosity was judged to be practically low if the melt viscosity at 160 ° C. was 1500 MPa · s or less.

(2) Softening point According to JIS-K2207, a specified ring is filled with a sample, supported horizontally in water, a 3.5 g ball is placed in the center of the sample, and the liquid temperature is increased at a rate of 5 ° C / min. Then, the temperature when the sample touched the bottom plate of the ring base with the weight of the sphere was measured.
The heat resistance and holding power of the adhesive composition were evaluated based on the height of the softening point.

(3) Tack 250 mm long × 15 mm wide loop-shaped sample was used, and a stainless steel plate was used as the adherend, and the contact area was 15 mm × 50 mm, the bonding time was 3 sec, and the bonding and peeling speed was 500 mm / min. .

(4) Adhesive force A sample having a width of 25 mm was attached to a stainless steel plate, and the force when the sample was folded 180 degrees parallel to the stainless steel plate surface and peeled off at a speed of 300 mm / min was measured.

(5) Holding force According to JIS Z-1524, the adhesive force is applied to the stainless steel plate so that an area of 25 mm x 25 mm is in contact, and a load of 1 kg is applied at 60 ° C until the adhesive tape slips off. Was measured.

  As shown in Tables 2 and 3 below, in each of Examples 1 to 7, the tack is 8 N / 15 mm or more, the adhesive strength is 8 N / 10 mm or more, the holding force is 3 minutes or more, and is sufficiently high in practical use. It was found that the balance of these properties was good and the melt viscosity was sufficiently low for practical use.

  In Table 2, the composition of the adhesive compositions of Examples 1 to 5 is as follows: copolymer for adhesive (polymer) / tackifying resin / softener + stabilizer = 30/50/20 (mass%) ) +0.3 (parts by mass).

  In Table 3, the composition of the adhesive compositions of Comparative Examples 1 to 7 and Examples 6 and 7 is as follows: copolymer for adhesive (polymer) / tackifying resin / softener + stabilizer = 30 / It shall be 50/20 (mass%) + 0.3 (mass part).

  Copolymers for adhesives and adhesive compositions according to the present invention are adhesives having non-stretchable sheets and adhesive compositions having the stretchability of various sanitary products such as disposable diapers and sanitary products. Can be used industrially as stretchable sheets laminated with various materials, various adhesive tapes / labels, pressure-sensitive thin plates, pressure-sensitive sheets, back paste for fixing various lightweight plastic molded products, back paste for fixing carpets, back paste for fixing tiles, etc. There is sex.

Claims (11)

Mainly composed of vinyl aromatic monomer unit (a) and conjugated diene monomer unit (b),
One or more polymer blocks mainly composed of vinyl aromatic monomer units, mainly conjugated diene units
Containing one or more polymer blocks to form a body,
Copolymer for adhesives satisfying the following conditions (1) to (4).
(1) The content of the vinyl aromatic monomer unit is 20 to 60% by mass.
(2) The hydrogenation rate in the conjugated diene monomer unit is 10 to 50%.
(3) Polystyrene (GPC) measured by gel permeation chromatography (GPC)
PS) has two or more peaks in conversion molecular weight measurement.
(4) The molecular weight distribution (= weight average molecular weight (Mw) / number average molecular weight (Mn)) is 1.2 or more.   The copolymer for adhesives according to claim 1, wherein the molecular weight distribution is 1.4 or more. The copolymer for adhesives according to claim 1 or 2, wherein the proportion of the component having a molecular weight in terms of polystyrene of 100,000 or more is 5% to 40%. The copolymer for adhesives according to any one of claims 1 to 3, wherein a proportion of a component having a polystyrene-equivalent molecular weight of 50,000 or less is 20% to 80%. The copolymer for adhesives according to any one of claims 1 to 4, comprising at least one polymer block mainly composed of vinyl aromatic monomer units. It is a manufacturing method of the copolymer for adhesives according to any one of claims 1 to 5,
Organolithium is added to the polyvinyl aromatic compound, and the polyvinyl aromatic compound amount (mol) /
Adding a lithium amount (mol) in the range of 0.01 to 1.0;
Adding a monomer constituting the adhesive adhesive copolymer and polymerizing;
A step of hydrogenation;
The manufacturing method of the copolymer for adhesive agents which performs these sequentially. It is a manufacturing method of the copolymer for adhesives according to any one of claims 1 to 5,
A polyvinyl aromatic compound;
The polyvinyl aromatic compound amount (mol) / lithium amount (mol) is 0.01 to 1.0.
An amount of organolithium equivalent to the range of
A polar compound;
Mixing in random order;
Adding a monomer constituting the adhesive adhesive copolymer and polymerizing;
A step of hydrogenation;
The manufacturing method of the copolymer for adhesive agents which performs these sequentially. It is a manufacturing method of the copolymer for adhesives according to any one of claims 1 to 5,
Adding organic lithium;
Polyvinyl aromatic compound is converted into polyvinyl aromatic compound amount (mol) / lithium amount (mo
adding 1) so that the amount corresponds to a range of 0.01 to 1.0;
Conjugated diene compound has a conjugated diene compound amount (mol) / lithium amount (mol) of 1-1.
Adding to an amount corresponding to a range of 00;
Adding a polar compound;
In random order,
Thereafter, a monomer constituting the adhesive adhesive copolymer is added and polymerized ;
A step of hydrogenation;
The manufacturing method of the copolymer for adhesive agents which performs these sequentially . In the step of adding and polymerizing the monomer constituting the adhesive adhesive copolymer, after adding the monomer constituting the adhesive adhesive copolymer, the polyfunctional coupling agent is further added. The manufacturing method of the copolymer for adhesives as described in any one of Claims 6 thru | or 8 added. Copolymer for adhesives according to any one of claims 1 to 5 , 10-80% by weight,
10-80% by weight of tackifying resin,
0-70% by mass of softener,
Containing,
And the adhesive composition whose total amount of the said copolymer for adhesives, the said tackifying resin, and the said softener is 75 mass% or more. Copolymer for adhesives as described in any one of Claims 1 thru | or 5 , 10-100 mass%,
0-60 mass% of tackifying resin,
0-50 mass% of softener,
Containing,
And the adhesive agent composition for elastic members whose total amount of the said copolymer for adhesive agents, the said tackifying resin, and the said softener is 75 mass% or more.