KR20210041214A - Block copolymer composition - Google Patents

Abstract

Provided is a block copolymer composition, comprising: a diblock copolymer comprising a unit derived from a styrene-based monomer and a unit derived from a conjugated diene-based monomer; and a triblock copolymer which is a coupling polymer of the diblock copolymer, wherein the conjugated diene-based monomer includes an isoprene-derived unit and a functionalized isoprene-derived unit.

Description

Block copolymer composition {BLOCK COPOLYMER COMPOSITION}

The present invention relates to a block copolymer composition applied to the pressure-sensitive adhesive composition and a pressure-sensitive adhesive composition comprising the same.

Hot melt adhesive is an adhesive that melts by heat using a thermoplastic resin, thereby forming an adhesive surface. Unlike conventional UV-curable adhesives, it does not use volatile solvents, so it is a hazardous substance during curing. Because of its low emission, it is preferred as an environmentally friendly high-functional adhesive.

Hot melt adhesives are not only relatively cheaper than UV curable adhesives, but also because they exist in a liquid state at high temperatures, they are easy to apply and compress on a substrate or adherend, and then cool and solidify at room temperature within a few seconds to exhibit adhesion. Because it is, it is easy to use.

These hot melt adhesives are applied to the adherend in a molten state and then cooled to form a hard phase having cohesiveness, creep resistance, etc., so diapers, feminine hygiene products, industrial tapes, packaging tapes It is widely used in various industrial fields, such as pressure sensitive adhesive manufacturing electronic products, structural materials, etc.

Since the hot melt adhesive contains a base resin and an additive, for reasons such as compatibility, phase separation and bleeding may occur, resulting in a problem of decreasing adhesion, and high viscosity, during melt processing for adhesion, Relatively high temperature conditions are required, and in particular, problems such as viscosity change, odor generation, and discoloration may occur under such processing temperature conditions, so that the demand for low-viscosity products with relatively lowered melting temperatures is increasing.

Accordingly, there is a need to develop a hot melt adhesive that maintains low viscosity properties and improves processing processability, has excellent adhesion and heat resistance, and has excellent mechanical properties after curing.

KR 2002-0061654 A (2004.04.17.)

The present invention was conceived to solve the problem of the technology behind the present invention, and when applied to a hot melt adhesive, it is intended to provide a block copolymer composition that can be applied at high temperatures and has improved adhesion due to its high softening point. do.

According to an embodiment of the present invention for solving the above problems, the present invention is a diblock copolymer comprising a styrene-based monomer-derived unit and a conjugated diene-based monomer-derived unit, and a coupling polymer of the diblock copolymer. Including a triblock copolymer, the conjugated diene-based monomer-derived unit provides a block copolymer composition comprising an isoprene-derived unit and a functionalized isoprene-derived unit represented by the following formula (1).

[Formula 1]

In Formula 1, R may be an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or may be connected to each other to form one or more aliphatic rings or aromatic rings.

The block copolymer composition comprising the diblock copolymer and the triblock copolymer according to the present invention uses isoprene and isoprene into which a hydrophilic functional group is introduced as a conjugated diene monomer, and a unit derived from a conjugated diene monomer in the copolymer By controlling the content ratio of, when used in a hot melt adhesive composition, it is possible to improve adhesion with an adherend while maintaining a high softening point. At the same time, it is possible to implement a hot melt adhesive with improved processability due to a low viscosity change rate at high temperature.

Hereinafter, the present invention will be described in more detail to aid understanding of the present invention.

The present invention is not intended to limit the present invention to a specific disclosed form, which may be subjected to various changes and may have various forms, and all changes, equivalents, or substitutes included in the spirit and scope of the present invention It should be understood to include.

On the other hand, terms or words used in the description and claims of the present invention should not be construed as being limited to their usual or dictionary meanings, and the inventors will use the concept of terms to explain their own invention in the best way. Based on the principle that it can be defined appropriately, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

In addition, the terms and measurement methods used in the present invention may be interpreted as defined below unless otherwise noted.

On the other hand, in the present invention, the term'monomer-derived repeating unit' or'monomer-derived unit' may refer to a component, structure or substance itself derived from a monomer. It may mean a unit formed in a polymer. Furthermore, in some cases, the monomer-derived unit is not only a unit in which two or more repeating units are repeated, but also one monomer-derived unit is expressed as a monomer-derived repeating unit.

In the present invention, the term'block' refers to a form of a polymer chain formed by block polymerization of monomers, and may refer to a form in which a plurality of monomer-derived units are continuously connected. For example, the styrene-based monomer block may mean a polymer chain formed by block polymerization of a styrene-based monomer or an aggregate of units derived from a plurality of styrene-based monomers. In the present invention, the term'polymer block' may refer to a group of polymer chains formed by block polymerization of a monomer.

The block copolymer composition according to an embodiment of the present invention comprises a diblock copolymer comprising a styrene-based monomer-derived unit and a conjugated diene-based monomer-derived unit, and a triblock copolymer, which is a coupling polymer of the diblock copolymer. Can include.

First, the diblock copolymer is a diblock copolymer comprising a styrene-based monomer-derived unit and a conjugated diene-based monomer-derived unit, and more specifically, a styrene-based monomer block (S) including a styrene-based monomer-derived unit, and a conjugated It may be a diblock copolymer in SI form including a conjugated diene-based monomer block (I) containing a unit derived from a diene-based monomer.

The triblock copolymer is a coupling polymer prepared by a coupling reaction of two or more diblock copolymers, and may be typically an S-I-S type triblock copolymer. Meanwhile, the triblock copolymer may further include a unit derived from a coupling agent between the conjugated diene-based monomer block (I) and the styrene-based monomer block (S) according to a coupling agent or a coupling method.

The styrene-based monomer may be styrene, alpha-methylstyrene, para-methylstyrene, vinyl toluene, vinyl naphthalene, para-butyl styrene, or a combination thereof, and specifically styrene.

The styrene-based monomer-derived unit may be produced by polymerization of the styrene-based monomer, and the styrene-based monomer-derived unit included in the block copolymer is 10 to about 100 parts by weight of the diblock copolymer and the triblock copolymer. It may be 25 parts by weight, specifically 13 to 20 parts by weight, more specifically 15 to 16 parts by weight.

Since the styrene-based monomer has a glass transition temperature (Tg) value higher than room temperature, a hard segment unit having a relatively hard property is formed in the copolymer. Therefore, when the content of the unit derived from the styrene-based monomer is 10 parts by weight or more, it is possible to improve mechanical properties such as hardness of the hot melt adhesive (or composition) containing the block copolymer composition including the same, and at the same time maintain heat resistance. I can. In addition, when the content of the unit derived from the styrene-based monomer is 20 parts by weight or less, it is possible to increase processability by suppressing an excessive increase in viscosity of the hot melt adhesive (or composition), and at the same time, it is possible to prevent the problem of lowering the adhesive strength .

Meanwhile, the conjugated diene-based monomer may be 1,3-butadiene, isoprene, or a derivative thereof, or a mixture thereof. Specifically, the unit derived from the conjugated diene-based monomer may include isoprene and a functionalized isoprene represented by Formula 1 below.

[Formula 1]

In Formula 1, R may be an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or may be connected to each other to form one or more aliphatic rings or aromatic rings.

That is, in the case where the conjugated diene-based monomer contains isoprene in the unit derived from the conjugated diene-based monomer, it is possible to impart a higher adhesive strength as an adhesive formulation than when the conjugated diene-based monomer contains isoprene. Is advantageous in

Meanwhile, the conjugated diene-based monomer may further include a functionalized isoprene represented by Formula 1 in addition to isoprene. Accordingly, the unit derived from a conjugated diene-based monomer included in the block copolymer according to an embodiment of the present invention may include an isoprene-derived unit and a functionalized isoprene-derived unit represented by Formula 1 at the same time.

When the block copolymer containing the functionalized isoprene-derived unit is included in the hot melt pressure-sensitive adhesive composition, there is an advantage that high adhesiveness and peel strength can be realized. Specifically, when the molecular weight of the triblock copolymer is increased for high thermal stability required for hot melt adhesives, although the thermal stability is improved, the adhesive strength tends to decrease.However, when the functionalized isoprene-derived unit is introduced, a trade-off is made. It is possible to coexist with high thermal stability and good adhesiveness of the hot melt adhesive, which is a trade-off relationship. This is thought to be due to a chemical interaction with the adhesive surface due to the hydrophilic functional group contained in the functionalized isoprene-derived unit.

Meanwhile, the functionalized isoprene-derived unit included in the block copolymer may be 10 to 50 parts by weight based on 100 parts by weight of the total 100 parts by weight of the isoprene-derived unit and the functionalized isoprene-derived unit. In the case of the above range, adhesion and peel strength may be improved while maintaining a high softening point. That is, when the content of the functionalized isoprene-derived unit is less than 10 parts by weight, the softening point is lowered and thermal stability is lowered, and when the content of the functionalized isoprene-derived unit is less than 10 parts by weight, the polarity contained in the block copolymer increases and the overall electrostatic attraction becomes stronger This makes it difficult to uniformly disperse the block copolymer composition particles due to aggregation between the particles of the block copolymer composition.

More specifically, the functionalized isoprene represented by Formula 1 may be represented by Formulas 2 to 4 below.

[Formula 2]

[Formula 3]

[Formula 4]

When the block copolymer containing the functionalized isoprene-derived unit represented by Formulas 2 to 4 is used as a hot melt pressure-sensitive adhesive (or composition), due to the high thermal stability of the phosphorus-based (phosphorous) functional group, during the manufacturing process of the high-temperature pressure-sensitive adhesive composition , As there is little damage to functional groups due to heat, it is excellent in usability with other ingredients even at high temperature.

Meanwhile, the diblock copolymer may be 15 to 65 parts by weight, specifically 18 to 35 parts by weight, based on 100 parts by weight of the diblock copolymer and the triblock copolymer. According to an embodiment of the present invention, the triblock copolymer may be prepared by carrying out a coupling reaction with respect to the diblock copolymer including the unit derived from the styrene-based monomer and the unit derived from the conjugated diene-based monomer. In this process, a diblock copolymer that does not participate in the coupling reaction remains and may be included in the block copolymer composition. That is, the block copolymer composition of the present invention may include a triblock copolymer and a diblock copolymer remaining without participating in the coupling reaction.

On the other hand, when the content of the diblock copolymer is 15 parts by weight or more, adhesion may be improved due to an appropriate increase in viscosity. On the other hand, the increase in adhesive strength according to the increase in the content of the diblock copolymer increases the adhesive strength up to 65 parts by weight, and when the content exceeds 65 parts by weight, the adhesive strength is rather reduced due to the too low viscosity. On the other hand, since the heat resistance property tends to decrease depending on the content of the diblock copolymer, it is important to control the content range of the diblock copolymer suitable for the use of the pressure-sensitive adhesive.

On the other hand, the weight average molecular weight (Mw) of the triblock copolymer according to an embodiment of the present invention may be 50,000 to 250,000, and appropriate adhesive strength and heat resistance of the pressure-sensitive adhesive composition may be secured within this range. The weight average molecular weight (Mw) was measured by liquid chromatography (HPLC) by dissolving a sample in a THF solvent.

Meanwhile, the coupling agent may include silane derivatives such as dimethyldichlorosilane, tetrachlorosilane, dimethyldiethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, and tetramethoxysilane.

The hot melt adhesive composition according to an embodiment of the present invention may include the above-described block copolymer composition, tackifier, plastic oil, and antioxidant.

The block copolymer composition may be included in a total of 100 parts by weight and 10 to 40 parts by weight of the hot melt adhesive composition.

The tackifier included in the hot melt pressure-sensitive adhesive composition may include at least one of a hydrogenated rosin ester-based compound and at least a partially hydrogenated dicyclopentadiene-based polymerized petroleum resin. Here, the term rosin refers to abietic acid, dehydroabietic acid from which hydrogen has been removed from abietic acid, and dihydro to which two or four hydrogens have been added, or tetrahydroabiet. As a concept including both acids (Dihydro- and Tetrahydro-), abietic acid and dihydroabietic acid to which two hydrogens are added are used as a concept that contains all of the various isomers depending on the position of the double bond.

Rosin ester-based compounds are esterified by reacting the carboxyl group of abietic acid with the OH group of alcohol or polyol based on the above-described abietic acid or hydrogenated abietic acid structure, which is also natural rosin or Includes all esterified products of modified rosin. The alcohol or polyol is, for example, an aliphatic alcohol having 1 to 20 carbon atoms, and may be in the form of a mono alcohol, diol, triol, tetraol, pentaol, and more specifically, for example, methanol, ethanol, Glycerol, ethylene glycol, diethylene glycol, or pentaerythritol. When a polyol is used, abietic acid may cause an esterification reaction with all or part of the hydroxyl groups of the polyol, and thus, polyhydric esters, such as monoesters, diesters, ternary esters, or quaternary esters, are Can be formed.

On the other hand, the dicyclopentadiene-based polymerized petroleum resin is produced as a by-product in the naphtha cracking process, which decomposes Naphtha obtained by refining crude oil at high temperature, that is, C9-dish produced from cyclopentadiene fraction. It means a petroleum resin containing clopentadiene.

Cyclopentadiene generated in the naphtha cracking process, in most cases, is dimerized and exists in a dicyclopentadiene structure. By reaction, mutual conversion is possible, and in particular, cyclopentadiene can be polymerized to dicyclopentadiene by thermal polymerization or catalytic polymerization. Therefore, that the tackifier used in the present invention includes at least a partially hydrogenated dicyclopentadiene-based polymer petroleum resin, at least among the dicyclopentadiene-based compounds contained in the above-described dicyclopentadiene-based polymerized petroleum resin. Hydrogen is added to some of the dicyclopentadiene, which may mean that both dicyclopentane and dicyclopentadiene are included.

According to an embodiment of the present invention, the tackifier may be included in an amount of about 200 to about 400 parts by weight or about 250 to about 350 parts by weight based on 100 parts by weight of the block copolymer composition. When too little tackifier is included, the tackifier effect is insignificant, and in the hot melt adhesive composition, a problem may occur in that physical properties related to dots and adhesion are not sufficiently exhibited. When too much tackifier is included, the adhesive component The cohesive force is lowered, and again, there may be a problem in that the adhesion-related physical properties are deteriorated.

Furthermore, the plastic oil included in the hot melt adhesive composition may include a petroleum mineral oil. Petroleum mineral oil is a liquid by-product generated in the process of refining crude oil into petroleum, and is also called liquid paraffin, and is typically based on paraffinic oil and cycloalkanes based on n-alkanes. There is a naphthenic oil and an aromatic oil based on an aromatic hydrocarbon, and in the present invention, the petroleum mineral oil is a concept including all of the above-described oil and oil modified therefrom. According to an example of the present invention, the petroleum mineral oil is preferably a paraffinic oil, and a white oil modified by hydrotreated and/or dewaxed in the presence of a catalyst, etc. It may be more desirable.

Meanwhile, the plastic oil may be included in an amount of about 50 to about 150 parts by weight, preferably about 70 to about 130 parts by weight, or about 90 to about 110 parts by weight, based on 100 parts by weight of the block copolymer composition. When the content of the plastic oil is too small, there may be a problem that fluidity and low-temperature workability are deteriorated, and when the content of the plastic oil is too large, the viscosity increases too much and the adhesive performance is rather deteriorated.

In addition, the hot melt adhesive composition according to an embodiment of the present invention may further include additives such as known light stabilizers, fillers, antioxidants, and ultraviolet absorbers, if necessary. These additions may be included in an amount of about 0.1 to about 10% by weight of the total composition in terms of preventing a decrease in adhesive properties, processability, and mechanical properties after adhesion.

Meanwhile, according to an embodiment of the present invention, there is provided an adhesive member comprising a substrate and an adhesive layer formed on at least one side of the substrate and formed by a hot melt adhesive composition according to an embodiment of the present invention. .

The adhesive member may be in the form of a film or tape, and the substrate may be a film having a single layer or a laminated structure of two or more layers.

A method of preparing a block copolymer composition according to an embodiment of the present invention will be described.

Styrene-based monomers and conjugated diphosphorus monomers used in the preparation method are as described above.

The manufacturing method may include preparing a styrene-based monomer block by polymerizing a styrene-based monomer in the presence of a polymerization initiator in a hydrocarbon solvent.

The hydrocarbon solvent is not particularly limited as long as it does not react with a polymerization initiator and is usually used in a polymerization reaction, and examples thereof include linear or branched hydrocarbon compounds such as butane, n-pentane, n-hexane, n-heptane or isooctane; Alkyl substituted or unsubstituted cyclic hydrocarbon compounds such as cyclopentane, cyclohexane, cycloheptane, methyl cyclohexane, and methyl cycloheptane; And it may be one or more selected from the group consisting of alkyl substituted or unsubstituted aromatic hydrocarbon compounds such as benzene, toluene, xylene, and naphthalene.

In addition, the hydrocarbon solvent may contain a polar additive to control the vinyl content and improve the polymerization rate, and the polar additive is, for example, at least one selected from the group consisting of tetrahydrofuran, ethyl ether, tetramethyl ethylene diamine, and benzofuran. I can.

In addition, the polymerization initiator is not particularly limited as long as it is usually used for anionic polymerization, but, for example, n-butyllithium, sec-butyllithium, tert-butyllithium, methyllithium, ethyllithium, isopropyllithium, cyclohexyllithium, allyl It may be one or more selected from the group consisting of lithium, vinyl lithium, phenyl lithium, and benzyl lithium.

Next, the step of polymerizing the styrene-based monomer block and the conjugated diene-based monomer to prepare a diblock copolymer including a styrene-based monomer-derived unit and a conjugated diene-based monomer-derived unit may be performed. In this step, the styrene-based monomer block and the conjugated diene-based monomer may be polymerized in the presence of a hydrocarbon solvent and a polymerization initiator, wherein the hydrocarbon solvent and the polymerization initiator are as described above.

Hereinafter, the present invention will be described in more detail by examples. However, the following examples are intended to illustrate the present invention, and that various changes and modifications can be made within the scope of the present invention and the scope of the technical idea are obvious to those skilled in the art, and the scope of the present invention is not limited thereto.

Example

<Preparation of block copolymer composition>

Example 1

A 10 L reactor substituted with argon (Ar) was set to a temperature of 50° C. and a pressure of 1.0 bar, and cyclohexane (5000 g), styrene (110 g), and tetrahydrofuran (50 g) were added and stirred. After stirring for 10 minutes, n-butyl lithium (25 g) was added to initiate polymerization. 15 minutes after the polymerization temperature of the styrene monomer reaches the maximum temperature, isoprene monomer (558 g) was added, and the functionalized isoprene represented by Chemical Formula 2 ((2-methylenebut-3-en-1-yl) diphenylphosphane, 229.4 g) was immediately added to perform polymerization. Dimethyldichlorosilane (1.0 g) as a coupling agent was added 10 minutes after the isoprene polymerization temperature reached the maximum temperature. After 10 minutes of the addition of the coupling agent, the polymerization was terminated by adding methanol, which is a polymerization terminator, and after stirring for 10 minutes, an antioxidant was added. Finally, distilled water was added to a glass reactor equipped with a stirrer, and the temperature was maintained at 90°C by a circulator. At the same time, while stirring, the prepared polymer was slowly added using a dropping funnel to remove cyclohexane. The resulting crumb was dried at low temperature to prepare a block copolymer composition.

Example 2

In place of the functionalized isoprene represented by Chemical Formula 2, a functionalized isoprene represented by Chemical Formula 3 (1-(2-methylenebut-3-en-1-yl)-2,5-diphenyl-phosphole, 272.8 g) was added. Except, a block copolymer composition was prepared in the same manner as in Example 1.

Example 3

The same as in Example 1, except that functionalized isoprene (Diphenyl(2-methylenebut-3-en-1-yl)phosphonite, 260.4 g) represented by Chemical Formula 4 was added instead of the functionalized isoprene represented by Chemical Formula 2 A block copolymer composition was prepared by the method.

Example 4

A block copolymer composition was prepared in the same manner as in Example 1, except that 458.8 g of functionalized isoprene represented by Formula 2 and 496 g of isoprene were added.

Example 5

A block copolymer composition was prepared in the same manner as in Example 1, except that 688.2 g of functionalized isoprene represented by Formula 2 and 434 g of isoprene were added.

Example 6

A block copolymer composition was prepared in the same manner as in Example 1, except that 917.6 g of functionalized isoprene represented by Formula 2 and 372 g of isoprene were added.

Example 7

A 10 L reactor substituted with argon (Ar) was set to a temperature of 50° C. and a pressure of 1.0 bar, and cyclohexane (5000 g), styrene (110 g), and tetrahydrofuran (50 g) were added and stirred. After stirring for 10 minutes, n-butyl lithium (12.5 g) was added to initiate polymerization. 15 minutes after the polymerization temperature of the styrene monomer reaches the maximum temperature, isoprene monomer (558 g) was added, and the functionalized isoprene represented by Chemical Formula 2 ((2-methylenebut-3-en-1-yl) diphenylphosphane, 229.4 g) is added immediately to perform polymerization. Dimethyldichlorosilane (0.5 g) as a coupling agent was added 10 minutes after the isoprene polymerization temperature reached the maximum temperature. After 10 minutes of the addition of the coupling agent, the polymerization was terminated by adding methanol, which is a polymerization terminator, and after stirring for 10 minutes, an antioxidant was added. Finally, distilled water is added to a glass reactor equipped with a stirrer, and the temperature is maintained at 90°C by a circulator. At the same time, while stirring, the prepared polymer is slowly added using a dropping funnel to remove cyclohexane. The resulting crumb was dried at low temperature to prepare a block copolymer composition.

Comparative Example 1

A block copolymer composition was prepared in the same manner as in Example 1, except that 620 g of isoprene was added and functionalized isoprene was not added.

Comparative Example 2

A 10 L reactor substituted with argon (Ar) was set to a temperature of 50° C. and a pressure of 1.0 bar, and cyclohexane (5000 g), styrene (110 g), and tetrahydrofuran (50 g) were added and stirred. After stirring for 10 minutes, n-butyl lithium (12.5 g) was added to initiate polymerization. Isoprene monomer (620 g) is added 15 minutes after the polymerization temperature of the styrene monomer reaches the maximum temperature, and dimethyldichlorosilane (0.5 g) is a coupling agent 10 minutes after the polymerization temperature of the styrene monomer reaches the maximum temperature. ) Was added. After 10 minutes of the addition of the coupling agent, the polymerization was terminated by adding methanol, which is a polymerization terminator, and after stirring for 10 minutes, an antioxidant was added. Finally, distilled water is added to a glass reactor equipped with a stirrer, and the temperature is maintained at 90°C by a circulator. At the same time, while stirring, the prepared polymer is slowly added using a dropping funnel to remove cyclohexane. The resulting crumb was dried at low temperature to prepare a block copolymer composition.

Comparative Example 3

A block copolymer composition was prepared in the same manner as in Example 1, except that 1147 g of functionalized isoprene represented by Formula 2 and 310 g of isoprene were added.

Comparative Example 4

A block copolymer composition was prepared in the same manner as in Example 1, except that 1376.4 g of functionalized isoprene represented by Formula 2 and 248 g of isoprene were added.

Experimental Example 1

The properties of the block copolymer composition prepared according to the above Examples and Comparative Examples are shown in Tables 1 and 2.

1) Measurement of molecular weight (g/mol) of triblock copolymer

The molecular weight of the triblock copolymer in the block copolymer composition including the triblock copolymer and the diblock copolymer was measured. Specifically, the molecular weight of the triblock copolymer was specified by GPC, and for GPC, an instrument consisting of a Waters 2707 autosampler, a Waters 2414 Refractive index detector, and a Waters 1515 Isocratic HPLC pump was used. Tetrahydrofuran (Fisher T425-4) was used as a developing solvent for GPC, and a sample (4 mg of triblock copolymer was dissolved in 4 ml of THF) was prepared by completely dissolving with a shaker. The prepared sample was introduced using an autosampler, and the isocratic flow was 1 ml/min. The column temperature was set to 40°C both inside and outside. The total running time per sample was 45 minutes, and the taken data was obtained by using a dedicated Waters analysis program to obtain molecular weight (Mw information). The molecular weight of the triblock copolymer was measured by analyzing a portion with a large molecular weight among the two peaks on the GPC.

2) Content of diblock copolymer (parts by weight)

The content of the diblock copolymer was measured with respect to 100 parts by weight of the block copolymer composition including the triblock copolymer and the diblock copolymer. The GPC analyzer as described above was used, and the small molecular weight portion of the two peaks on the GPC was analyzed and measured.

3) Total styrene content (parts by weight)

The total content of units derived from styrene monomers was measured with respect to 100 parts by weight of the block copolymer composition including the triblock copolymer and the diblock copolymer. Analysis was performed using Varian VNMRS 500 Mhz NMR, and 1,1,2,2-tetrachloroethane D2 from Cambridge Isotope was used as a solvent. The styrene content was determined by the value of the area measured by integrating the peak between NMR 7.4 ~ 6.0 ppm.

4) Functionalized isoprene content (parts by weight)

The content of the functionalized isoprene-derived unit relative to the total 100 parts by weight of the isoprene-derived unit and the functionalized isoprene-derived unit included in the block copolymer was measured. Analysis was performed using Varian VNMRS 500 Mhz NMR, and 1,1,2,2-tetrachloroethane D2 from Cambridge Isotope was used as a solvent. The content of functionalized isoprene was determined as the value of the area measured by integrating the peak near 2.0 ppm.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 (One) 111,000 110,900 112,000 112,500 110,500 112,200 223,500 (2) 19 19 19 20 19 19 20 (3) 15.1 15.0 15.2 15.1 15.0 15.1 15.2 (4) 9.8 9.7 9.6 19.5 29.6 39.5 9.7 (1) Molecular weight of triblock copolymer (g/mol)
(2) Content of diblock copolymer (parts by weight)
(3) Total styrene content (parts by weight)
(4) Functionalized isoprene content (parts by weight)

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 (One) 110,090 223,000 110,900 111,000 (2) 19 20 19 19 (3) 15.0 15.1 15.1 15.0 (4) 0 0 49.8 60.1 (1) Molecular weight of triblock copolymer (g/mol)
(2) Content of diblock copolymer (parts by weight)
(3) Total styrene content (parts by weight)
(4) Functionalized isoprene content (parts by weight)

<Preparation of hot melt adhesive composition>

In an lL glass beaker, white mineral oil Kaydol (Sonneborn) is a plastic oil, Escorez 5600 (ExxonMobil), a hydrogenated dicyclopentadiene polymerized petroleum resin as a tackifier, Irganox 1010 as an antioxidant, Irgafos 168 as a stabilizer, and Tinuvin as a UV absorber. P (above, BASF) was added and heated in a convection oven at 150° C. for about 30 minutes. Subsequently, the glass beaker was fixed to a 150°C heating mantle and stirred at 100 rpm, and after the temperature inside the beaker reached 150°C, the speed was increased to 150 rpm and further stirred.

Here, the block copolymer composition prepared in Examples and Comparative Examples was slowly added dropwise and stirred at a speed of 200 rpm for 4 hours to completely dissolve the block copolymer composition, thereby preparing a hot melt pressure-sensitive adhesive composition.

<Production of adhesive member>

The hot melt adhesive composition containing the block copolymer composition prepared in the above Examples and Comparative Examples was heated at 180° C. for about 5 minutes to confirm melting, and this was applied on the PET substrate on the applicator at 180° C., and then the blade was applied. By using the coating so that the thickness of the adhesive layer was 50 μm, the same PET substrate was bonded together as a cover film to prepare an adhesive member.

Experimental Example 2

For each hot melt adhesive composition containing the block copolymer composition prepared in Examples and Comparative Examples, the softening point, tackiness, peel strength, and viscosity change rate were measured in the following manner, and the results are shown in Tables 3 and 4. I got it.

.

1) softening point

Using the Automatic Softening Point Analyzer RB 365G Model, the hot melt adhesive composition was sufficiently put in a ring, left for 1 hour, and then a ball (diameter: 9.525mm, weight: 3.5g) was placed. The sample was heated while raising the temperature at a rate of 5° C., and the temperature when the ball was sagging 1 inch was measured. (Related standard: ASTM D36).

2) adhesiveness

The adhesiveness of the adhesive member prepared above was measured using an LT-1000 Loop Tack Tester. The adhesive member sample was cut to a width of 1 inch and a length of 100 mm, and after fixing it by folding it in half on a measuring instrument holder at room temperature, the adhesive force when it was adhered to a metal plate and dropped off was measured (Related Regulation ASTM: D 6195B)

3) Peel strength

The adhesive member prepared above was measured for adhesive force in a T-peel method using a Texture Analyzer (TA). The adhesive member sample was cut to a width of 1 inch and a length of 100 mm, and was measured at room temperature at a speed of 0.3 m/min. (Related standard: ASTM D1876,

4) Viscosity change rate

About 10 g of the hot melt pressure-sensitive adhesive composition was put into a sample chamber, and viscosity at 140° C. and 160° C. was measured for 30 minutes using a Brookfield viscometer (DV2+ Model, Spindle Number 27). Thereafter, the hot melt pressure-sensitive adhesive composition was allowed to stand for 24 hours under the same conditions, and then the viscosity was measured in the same manner to calculate the viscosity reduction rate at 140°C and 160°C. (Related standard: ASTM D4402)

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Softening point (℃) 82.3 82.5 82.2 83.8 85.6 87.7 91.5 Adhesiveness (g) (loop tack) 2,000 1,980 1,950 2,150 2,300 2,430 1,730 Peel strength(Kg)(180°peel strength) 1.05 1.03 1.04 1.13 1.22 1.31 0.85 Viscosity change rate (%) (180℃, 24h) 25 24 26 20 16 13 30

Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Softening point (℃) 80.2 89.6 88.2 89.5 Adhesiveness (g) (loop tack) 1,710 1,520 2,110 1,830 Peel strength(Kg)(180°peel strength) 0.84 0.76 1.08 0.92 Viscosity change rate (%) (180℃, 24h) 35 40 20 30

As can be seen in Tables 1 to 4, the conjugated diene-based monomer constituting the triblock copolymer and the diblock copolymer of the block copolymer composition is used in a specific content range of isoprene and a specific functionalized isoprene, and this is used in an adhesive composition. In this case, it can be seen that the adhesive properties (adhesion and peel strength) are simultaneously improved while maintaining a high softening point. Furthermore, it can be seen that the viscosity change rate is also low, so that it is suitable for use as an adhesive (Examples 1 to 7).

On the other hand, when the functionalized isoprene is not used (Comparative Examples 1 and 2), it can be seen that the adhesive properties (adhesiveness and peel strength) and the viscosity change rate are lowered, and even when the functionalized isoprene is used, it is used in excessive amounts. In the case of (Comparative Examples 3 and 4), it can be seen that the adhesive properties (adhesiveness and peel strength) are rather lowered.

Claims (10)

A diblock copolymer comprising a styrene-based monomer-derived unit and a conjugated diene-based monomer-derived unit, and a triblock copolymer, which is a coupling polymer of the diblock copolymer,
The conjugated diene-based monomer-derived unit includes an isoprene-derived unit and a functionalized isoprene-derived unit represented by the following formula (1):

[Formula 1]

In Formula 1, R may be an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, or may be connected to each other to form one or more aliphatic rings or aromatic rings.
The method of claim 1,
The functionalized isoprene-derived unit contained in the block copolymer is 10 to 50 parts by weight based on 100 parts by weight of the total 100 parts by weight of the isoprene-derived unit and the functionalized isoprene-derived unit.
The method of claim 1,
The block copolymer composition in which the unit derived from the styrene-based monomer contained in the block copolymer is 10 to 25 parts by weight based on 100 parts by weight of the diblock copolymer and the triblock copolymer.
The method of claim 1,
The diblock copolymer is a block copolymer composition of 15 to 65 parts by weight based on 100 parts by weight of the diblock copolymer and the triblock copolymer.
The method of claim 1,
The weight average molecular weight (Mw) of the triblock copolymer is 50,000 to 250,000 block copolymer composition.

The method of claim 1,
The functionalized isoprene is a block copolymer composition of any one of the following Formulas 2 to 4.

[Formula 2]

[Formula 3]

[Formula 4]

The method of claim 1,
The styrene-based monomer is styrene, alpha-methylstyrene, para-methylstyrene, vinyl toluene, vinyl naphthalene, para-butyl styrene, or a combination thereof.
A hot melt adhesive composition comprising the block copolymer composition of claim 1, a tackifier, a plastic oil, and an antioxidant.
The method of claim 8,
The block copolymer composition is a hot melt adhesive composition comprising a total of 100 parts by weight 100 to 40 parts by weight of the hot melt adhesive composition.
materials; And
An adhesive member formed on at least one surface of the substrate and comprising an adhesive layer formed by the hot melt adhesive composition of claim 8.