JP2022115582A - Hydrocarbon resin and hot melt adhesive composition - Google Patents

Abstract

To provide a hydrocarbon resin which can provide a hot melt adhesive composition having excellent holding power and tackiness with a good balance therebetween.SOLUTION: A hydrocarbon resin comprises an aliphatic monomer unit, or an aliphatic monomer unit and an aromatic monomer unit. The hydrocarbon resin has a weight average molecular weight (Mw) in the range of 500 to 6500, has a softening temperature of 50°C or higher and, in a GPC chart obtained by gel permeation chromatography (GPC) measurement, a peak height index, calculated from a peak top height (mV) and a peak area (mV×seconds) according to the following formula (1), is 0.5 or less: peak height index=(peak top height (mV)/peak area (mV)×100 (1).SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a hydrocarbon resin capable of providing a hot-melt pressure-sensitive adhesive composition having well-balanced holding power and tackiness, and a hot-melt pressure-sensitive adhesive composition using the same.

Hydrocarbon resins obtained by copolymerizing aliphatic monomers such as monoolefinic unsaturated hydrocarbons and chain conjugated diolefins and, if necessary, with aliphatic monomers are known. Such hydrocarbon resins are used, for example, as tackifying resins for forming hot-melt adhesive compositions.

As such a hydrocarbon resin, for example, in Patent Document 1, the glass transition temperature (Tg) is -50 ° C. to 160 ° C., the number average molecular weight is 3000 or less, the Z average molecular weight is 9000 or less, gel permeation A hydrocarbon resin is disclosed having an oligomer content of 55% by weight or less as determined by chromatography (GPC) and an oligomer content of 38% by weight or less as determined by high resolution thermogravimetric analysis (TGA). .

WO2018/187243

On the other hand, when a hydrocarbon resin is used as a tackifying resin for forming a hot-melt pressure-sensitive adhesive composition, for example, it is required that the holding power and tackiness are highly balanced and excellent. However, the technology disclosed in Patent Document 1 does not necessarily have sufficient properties.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a hydrocarbon resin capable of providing a hot-melt pressure-sensitive adhesive composition having an excellent balance between holding power and tackiness. do. Another object of the present invention is to provide a hot-melt adhesive composition using such a hydrocarbon resin.

The present inventors have conducted studies to achieve the above object, and found that the weight average molecular weight (Mw) and softening point temperature are within a specific range, and gel permeation chromatography (GPC) measurement The above object can be achieved by the hydrocarbon resin in which the peak height index obtained from the peak height [mV] of the peak top and the peak area [mV×sec] in the GPC chart is controlled within a specific range. and completed the present invention.

That is, according to the present invention, a hydrocarbon resin comprising an aliphatic monomer unit, or an aliphatic monomer unit and an aromatic monomer unit,
The weight average molecular weight (Mw) is in the range of 500 to 6500,
softening point temperature is 50 ° C. or higher,
A peak calculated according to the following formula (1) from the peak height [mV] of the peak top and the peak area [mV × second] in the GPC chart obtained by gel permeation chromatography (GPC) measurement A hydrocarbon resin is provided having a height index of 0.5 or less.
Peak height index = (Peak top height [mV]/Peak area [mV x sec]) x 100 (1)

The hydrocarbon resin of the present invention contains 20 to 70% by mass of 1,3-pentadiene monomer units,
1 to 50% by mass of alicyclic monoolefin monomer units having 4 to 6 carbon atoms,
0 to 50% by mass of acyclic monoolefin monomer units having 4 to 8 carbon atoms,
It preferably contains 0 to 1% by mass of alicyclic diolefin monomer units and 0 to 40% by mass of aromatic monoolefin monomer units.

Further, according to the present invention, there is provided a hot-melt pressure-sensitive adhesive composition containing the hydrocarbon resin.

According to the present invention, there is provided a hydrocarbon resin capable of providing a hot-melt pressure-sensitive adhesive composition having well-balanced holding power and tackiness, and a hot-melt pressure-sensitive adhesive using such a hydrocarbon resin. A composition can be provided.

1 is a GPC chart of a hydrocarbon resin according to Example 1. FIG.

The hydrocarbon resin of the present invention is a hydrocarbon resin comprising an aliphatic monomer unit, or an aliphatic monomer unit and an aromatic monomer unit,
The weight average molecular weight (Mw) is in the range of 500 to 6500,
softening point temperature is 50 ° C. or higher,
A peak calculated according to the following formula (1) from the peak height [mV] of the peak top and the peak area [mV × second] in the GPC chart obtained by gel permeation chromatography (GPC) measurement The height index is 0.5 or less.
Peak height index = (Peak top height [mV]/Peak area [mV x sec]) x 100 (1)

The hydrocarbon resin of the present invention may contain at least aliphatic monomer units, and may contain aromatic monomer units in addition to aliphatic monomer units.

(Aliphatic monomer unit)
First, the aliphatic monomer unit contained in the hydrocarbon resin of the present invention will be explained.
Aliphatic monomers for forming the aliphatic monomer units may be those containing no aromatic ring and containing at least unsaturated hydrocarbons. Examples of such aliphatic monomers include , 1,3-pentadiene, alicyclic monoolefin monomers having 4 to 6 carbon atoms, acyclic monoolefin monomers having 4 to 8 carbon atoms, alicyclic diolefin monomers, etc. can. Further, in the present invention, a mixture containing these aliphatic monomers may be added to the polymerization reaction system when producing the hydrocarbon resin. At this time, the aliphatic monomer contained in the mixture is used as a monomer unit component constituting the hydrocarbon resin. The addition-polymerizable components other than the aliphatic monomer contained in the mixture may also be used as constituent components of the monomer units of the hydrocarbon resin, and the non-addition-polymerizable component may be used as a solvent during polymerization. . As a mixture containing such an aliphatic monomer, for example, a C5 fraction containing 1,3-pentadiene, cyclopentene, isobutylene, etc. as an aliphatic monomer can be preferably used.

The hydrocarbon resin preferably contains, as aliphatic monomer units, 1,3-pentadiene units and alicyclic monoolefin monomer units having 4 to 6 carbon atoms. It may further contain 8 acyclic monoolefin monomer units and 8 cycloaliphatic diolefin monomer units.

The content of the 1,3-pentadiene monomer unit in the hydrocarbon resin is not particularly limited, but is preferably 20 to 70% by mass, more preferably 28 to 62% by mass, and still more preferably 32 to 58% by mass. % by weight, particularly preferably 37 to 53% by weight. By setting the content of the 1,3-pentadiene monomer unit within the above range, the hot-melt pressure-sensitive adhesive composition can be made more excellent in holding power and tackiness. The cis/trans isomer ratio in 1,3-pentadiene may be any ratio and is not particularly limited.

An alicyclic monoolefin having 4 to 6 carbon atoms forming an alicyclic monoolefin monomer unit having 4 to 6 carbon atoms has one ethylenically unsaturated bond and a non-aromatic ring in its molecular structure. It is a hydrocarbon compound having 4 to 6 carbon atoms and having the structure Specific examples of alicyclic monoolefins having 4 to 6 carbon atoms include cyclobutene, cyclopentene, cyclohexene, methylcyclobutene, methylcyclopentene and the like.

The content of the alicyclic monoolefin monomer unit having 4 to 6 carbon atoms in the hydrocarbon resin is not particularly limited, but is preferably 1 to 50% by mass, more preferably 10 to 42% by mass, More preferably 14 to 38 mass %, still more preferably 18 to 34 mass %. By setting the content of the alicyclic monoolefin monomer unit having 4 to 6 carbon atoms in the above range, the hot-melt pressure-sensitive adhesive composition has excellent holding power and tackiness. be able to.

As for the alicyclic monoolefin having 4 to 6 carbon atoms, the ratio of each compound corresponding to this may be any ratio and is not particularly limited, but it is preferable that at least cyclopentene is included, and 4 carbon atoms The proportion of cyclopentene in the alicyclic monoolefin of 1 to 6 is more preferably 50% by mass or more, still more preferably 80% by mass or more, and particularly preferably 100% by mass.

An acyclic monoolefin having 4 to 8 carbon atoms forming an acyclic monoolefin monomer unit having 4 to 8 carbon atoms has one ethylenically unsaturated bond in its molecular structure and has a ring structure. It is a chain hydrocarbon compound having 4 to 8 free carbon atoms. Specific examples of acyclic monoolefins having 4 to 8 carbon atoms include butenes such as 1-butene, 2-butene and isobutylene (2-methylpropene); 1-pentene, 2-pentene, 2-methyl-1 -pentenes such as butene, 3-methyl-1-butene and 2-methyl-2-butene; hexenes such as 1-hexene, 2-hexene and 2-methyl-1-pentene; 1-heptene and 2-heptene , 2-methyl-1-hexene and other heptenes; 1-octene, 2-octene, 2-methyl-1-heptene, diisobutylene (2,4,4-trimethyl-1-pentene and 2,4,4- octenes such as trimethyl-1-pentene);

The content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms in the hydrocarbon resin is not particularly limited, but is preferably 0 to 50% by mass, more preferably 8 to 40% by mass, More preferably 10 to 35% by mass, particularly preferably 12 to 33% by mass. By setting the content of the acyclic monoolefin monomer unit having 4 to 8 carbon atoms in the above range, the hot-melt pressure-sensitive adhesive composition has excellent holding power and tackiness. be able to.

As for the acyclic monoolefin having 4 to 8 carbon atoms, the ratio of each corresponding compound (including isomers) may be any ratio and is not particularly limited, but at least 2-methyl-2-butene , isobutylene, and diisobutylene, and 1-butene. In this case, from the viewpoint of keeping the peak height index in a GPC chart, which will be described later, within a predetermined range, these ratios are preferably set as follows.

That is, the ratio of the total amount of 2-methyl-2-butene, isobutylene, and diisobutylene in the acyclic monoolefin having 4 to 8 carbon atoms (that is, "2-methyl-2-butene, isobutylene , and the total amount of diisobutylene"/"the total amount of the acyclic monoolefin having 4 to 8 carbon atoms" × 100 (mass%)) is preferably 60 to 85 mass%, and 65 to 83 mass%. More preferably, when the weight average molecular weight (Mw) of the hydrocarbon resin is relatively low (for example, when the weight average molecular weight (Mw) is less than 2200), 65 to 75% by mass is further used. Preferably, it is particularly preferably 67 to 72% by mass, and when the weight average molecular weight (Mw) of the hydrocarbon resin is relatively high (for example, when the weight average molecular weight (Mw) is 2200 or more), More preferably 70 to 83% by mass, particularly preferably 75 to 83% by mass.

In addition, the ratio of 1-butene in the acyclic monoolefin having 4 to 8 carbon atoms (that is, "amount of 1-butene" / "amount of total acyclic monoolefin having 4 to 8 carbon atoms" × 100 (% by mass)) is preferably 13 to 32% by mass, more preferably 15 to 30% by mass, and when the weight average molecular weight (Mw) of the hydrocarbon resin is relatively low (for example, weight average When the molecular weight (Mw) is less than 2200), it is more preferably 23 to 30% by mass, particularly preferably 25 to 29% by mass, and the weight average molecular weight (Mw) of the hydrocarbon resin is relatively high (for example, when the weight average molecular weight (Mw) is 2200 or more), it is more preferably 15 to 27 mass %, particularly preferably 16 to 24 mass %. Furthermore, the amount of 1-butene in the hydrocarbon resin is preferably 1.5 to 11% by mass, more preferably 2 to 10% by mass, and the weight average molecular weight (Mw) of the hydrocarbon resin is relatively low (for example, when the weight average molecular weight (Mw) is less than 2200), it is more preferably 6 to 10% by mass, particularly preferably 7 to 9.5% by mass, Further, when the weight average molecular weight (Mw) of the hydrocarbon resin is relatively high (for example, when the weight average molecular weight (Mw) is 2200 or more), it is more preferably 2 to 9% by mass. It is particularly preferable to make it 5 to 7.5% by mass.

An alicyclic diolefin forming an alicyclic diolefin monomer unit is a hydrocarbon compound having two or more ethylenically unsaturated bonds and a non-aromatic ring structure in its molecular structure. . Specific examples of alicyclic diolefins include cyclopentadiene polymers such as cyclopentadiene and dicyclopentadiene, methylcyclopentadiene polymers, and methylcyclopentadiene polymers.

The content of the alicyclic diolefin monomer units in the hydrocarbon resin is not particularly limited, but is preferably 0 to 1% by mass, more preferably 0.05 to 0.8% by mass, still more preferably is 0.1 to 0.7% by weight, particularly preferably 0.15 to 0.6% by weight. By setting the content of the alicyclic diolefin monomer unit within the above range, the hot-melt pressure-sensitive adhesive composition can be made more excellent in holding power and tackiness.

Further, the hydrocarbon resin of the present invention includes 1,3-pentadiene monomer units, alicyclic monoolefin monomer units having 4 to 6 carbon atoms, aromatic monoolefin monomer units, and 4 to 4 carbon atoms. It may contain monomer units other than 8 acyclic monoolefin monomer units and alicyclic diolefin monomer units.

Other monomers forming such other monomer units are not particularly limited as long as they are addition-polymerizable compounds capable of being addition-copolymerized with 1,3-pentadiene or the like. Such other monomers include, for example, 1,3-butadiene, 1,2-butadiene, isoprene, 1,3-hexadiene, 1,4-pentadiene, and other monomers having 4 carbon atoms other than 1,3-pentadiene. alicyclic monoolefins having 7 or more carbon atoms such as cycloheptene; acyclic monoolefins having carbon atoms other than 4 to 8 such as ethylene, propylene and nonene;

The content of other monomer units in the hydrocarbon resin is usually in the range of 0-30% by mass, preferably 0-25% by mass, more preferably 0-20% by mass.

The content of the aliphatic monomer units in the hydrocarbon resin is not particularly limited, but is preferably 50% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass. 80% by mass or more, and particularly preferably 80% by mass or more.

(aromatic monomer unit)
The hydrocarbon resin of the present invention may contain aromatic monomer units in addition to aliphatic monomer units. The aromatic monomer for forming the aromatic monomer unit may have an aromatic ring and can be copolymerized with an aliphatic monomer. mers. In addition, in the present invention, a mixture containing aromatic monomers such as aromatic monoolefin monomers may be added to the polymerization reaction system during the production of the hydrocarbon resin. At this time, the aromatic monomer contained in the mixture is used as a component of the monomer units constituting the hydrocarbon resin. The addition-polymerizable components other than the aromatic monomer contained in the mixture may also be used as constituent components of the monomer units of the hydrocarbon resin, and the non-addition-polymerizable component may be used as a solvent during polymerization. . As a mixture containing such an aromatic monomer, for example, a C9 fraction containing a styrene compound, an indene compound, etc. as the aromatic monomer can be preferably used.

An aromatic monoolefin monomer is an aromatic compound having one ethylenically unsaturated bond in its molecular structure. Specific examples of aromatic monoolefins include styrene compounds such as styrene, α-methylstyrene, β-methylstyrene and vinyltoluene; indene compounds such as indene and 1-methylindene; and coumarone.

The content of aromatic monoolefin monomer units in the hydrocarbon resin is not particularly limited, but is preferably 0 to 40% by mass, more preferably 3 to 35% by mass, and still more preferably 8 to 25% by mass. %, particularly preferably 11 to 19% by weight. By setting the content of the aromatic monoolefin monomer unit within the above range, the hot-melt pressure-sensitive adhesive composition can have excellent holding power.

The weight average molecular weight (Mw) of the hydrocarbon resin of the present invention is in the range of 500 to 6500, preferably in the range of 1000 to 4500, more preferably in the range of 1300 to 4200, still more preferably in the range of 1500 to 3700. . The weight-average molecular weight (Mw) of the hydrocarbon resin can be determined as a polystyrene-equivalent value by gel permeation chromatography (GPC) measurement using tetrahydrofuran as a developing solvent.

Further, in the present invention, in addition to setting the weight average molecular weight (Mw) of the hydrocarbon resin to the above range, the peak top peak in the GPC chart obtained by gel permeation chromatography (GPC) measurement The peak height index, which is calculated according to the following formula (1) from the height [mV] and the peak area [mV × sec], is controlled to 0.5 or less, thereby holding the hydrocarbon resin It can be excellent in balance between strength and tackiness.
Peak height index = (Peak top height [mV]/Peak area [mV x sec]) x 100 (1)

Incidentally, when obtaining the peak height index, gel permeation chromatography (GPC) measurement can be performed using tetrahydrofuran as a developing solvent in the same manner as the measurement of the weight average molecular weight (Mw). In addition, the weight average molecular weight (Mw) can also be measured at the same time as a polystyrene-equivalent value.

Here, a GPC chart of the hydrocarbon resin according to Example 1 is shown in FIG. As shown in FIG. 1, in the GPC measurement, the RI (Refractive Index) intensity (unit: mV) at each elution time is detected by a refractometer (RI detector). Amount is detected, and a standard sample (polystyrene) is used to measure the molecular weight of the polymer contained in the measurement sample. Then, in the present invention, when the RI intensity in the developing solvent alone is 0 mV (when set as the baseline), the peak height [mV] of the peak top and the peak area [mV × sec] are used to determine the above The peak height index obtained according to the formula (1) shall be 0.5 or less. The peak height index may be 0.5 or less, preferably in the range of 0.28 to 0.5, more preferably in the range of 0.3 to 0.5, still more preferably 0.32 to It is in the range of 0.49.

In addition, as a gel permeation chromatography measurement when measuring the peak height index, for example, as a measuring device, Tosoh Corporation "HLC-8320GPC" is used, and as a column, Tosoh Corporation "TSKgel SuperMultiporeHZ ", using tetrahydrofuran as a solvent (hydrocarbon resin dissolved in tetrahydrofuran at 1.4% by mass), sample inflow amount 100 μL, 40 ° C., flow rate of 1.0 mL / min It can be carried out. The peak height [mV] of the peak top and the peak area [mV×sec] may be calculated using an analysis program or the like provided in the measuring device.

Further, when obtaining the peak height index, if two or more peaks derived from a hydrocarbon resin are observed in the GPC chart, the height of the peak with the highest peak height is the peak height of the peak top. and the peak area may be the sum of the areas of all the peaks.

In addition, in the present invention, the weight average molecular weight (Mw) and peak height index of the hydrocarbon resin can be adjusted by the type and amount of the monomer used for polymerization and the polymerization conditions. Among them, the peak height index is the ratio of the total amount of 2-methyl-2-butene, isobutylene, and diisobutylene in the acyclic monoolefin having 4 to 8 carbon atoms, and the content of 1-butene. A method of adjusting the proportion occupied, a method of adjusting the amount of the polymerization catalyst used, a method of adjusting the polymerization temperature, and a method of adjusting the mixing temperature and mixing time when the polymerization catalyst is previously mixed in the volatile solvent. It can be controlled by a suitable combination method.

The number average molecular weight (Mn) of the hydrocarbon resin of the present invention is not particularly limited, but is preferably in the range of 350 to 1900, more preferably in the range of 700 to 1700, and the Z average molecular weight (Mz) is Although not particularly limited, it is preferably in the range of 1,000 to 23,000, more preferably in the range of 2,100 to 12,500.

The ratio of weight average molecular weight to number average molecular weight (Mw/Mn) of the hydrocarbon resin of the present invention is not particularly limited, but is preferably in the range of 1.3 to 3.7, more preferably 1.5. Although the ratio of the Z-average molecular weight to the weight-average molecular weight (Mz/Mw) is not particularly limited, it is preferably in the range of 1.3 to 3.7, more preferably 1.5. ~3.7.

The number average molecular weight (Mn), the Z average molecular weight (Mz), the ratio of the weight average molecular weight to the number average molecular weight (Mw/Mn) and the ratio of the Z average molecular weight to the weight average molecular weight (Mz/Mw) of the hydrocarbon resin also Similarly to the average molecular weight (Mw), tetrahydrofuran is used as a developing solvent, and it can be obtained as a polystyrene-equivalent value by gel permeation chromatography measurement.

Further, the softening point temperature of the hydrocarbon resin of the present invention is 50° C. or higher, preferably in the range of 80 to 150° C., more preferably in the range of 85 to 145° C., and further in the range of 90° C. to 140° C. A temperature range of 90 to 105° C. is particularly preferred. By setting the softening point within the above range, the resin can be easily melted during hot-melt kneading and the compatibility with the base polymer can be enhanced when used in a hot-melt pressure-sensitive adhesive composition. , which can increase holding power and tackiness. The softening point of the hydrocarbon resin can be measured according to JIS K6863.

<Method for producing hydrocarbon resin>
The method for producing the hydrocarbon resin of the present invention is not particularly limited, but includes a method of addition polymerization of a monomer mixture for constituting the hydrocarbon resin. A method by addition polymerization using is preferably exemplified.

The Friedel-Crafts-type cationic polymerization catalyst is not particularly limited, but may include halides such as aluminum, iron, tantalum, zirconium, tin, beryllium, boron, antimony, gallium, bismuth and molybdenum. Among them, aluminum halides such as aluminum chloride (AlCl ₃ ) and aluminum bromide (AlBr ₃ ) are suitable. The amount of the Friedel-Crafts-type cationic polymerization catalyst used is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, with respect to 100 parts by mass of the monomer mixture used for polymerization. It is preferably 0.4 to 2.0 parts by mass, particularly preferably 0.5 to 1.7 parts by mass.

Further, in the polymerization, a halogenated hydrocarbon may be used in combination with the Friedel-Crafts-type cationic polymerization catalyst from the viewpoint that the catalytic activity can be further enhanced.

Specific examples of halogenated hydrocarbons include halogenated hydrocarbons in which a halogen atom is bonded to a tertiary carbon atom such as t-butyl chloride, t-butyl bromide, 2-chloro-2-methylbutane, triphenylmethyl chloride; benzyl Carbon-carbon unsaturated bonds such as chloride, benzyl bromide, (1-chloroethyl)benzene, allyl chloride, 3-chloro-1-propyne, 3-chloro-1-butene, 3-chloro-1-butyne, cinnamon chloride, etc. halogenated hydrocarbon in which a halogen atom is bonded to the carbon atom adjacent to; Among these, t-butyl chloride and benzyl chloride are preferred from the viewpoint of excellent balance between catalytic activity and handleability. Halogenated hydrocarbons may be used singly or in combination of two or more. The amount of halogenated hydrocarbon used is preferably in the range of 0.05 to 50, more preferably in the range of 0.1 to 10, in terms of molar ratio to the Friedel-Crafts-type cationic polymerization catalyst.

Moreover, from the viewpoint of better control of the polymerization reaction, it is preferable to add a volatile solvent to the polymerization reaction system and carry out the polymerization reaction. The type of volatile solvent is not particularly limited as long as it does not interfere with the polymerization reaction, but saturated aliphatic hydrocarbons or aromatic hydrocarbons are suitable. Examples of saturated aliphatic hydrocarbons include n-pentane, n-hexane, 2-methylpentane, 3-methylpentane, n-heptane, 2-methylhexane, 3-methylhexane, 3-ethylpentane, 2,2 - C5-C10 compounds such as dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 2,2,3-trimethylbutane and 2,2,4-trimethylpentane chain saturated aliphatic hydrocarbons; cyclic saturated aliphatic hydrocarbons having 5 to 10 carbon atoms such as cyclopentane, cyclohexane, cycloheptane and cyclooctane; Examples of aromatic hydrocarbons include aromatic hydrocarbons having 6 to 10 carbon atoms such as benzene, toluene and xylene. Volatile solvents may be used singly or in combination of two or more. The amount of the volatile solvent used is not particularly limited, but is preferably 10 to 1,000 parts by mass, more preferably 50 to 500 parts by mass, based on 100 parts by mass of the monomer mixture used for polymerization.

In carrying out the polymerization reaction, the order of adding the respective components of the monomer mixture and the polymerization catalyst to the polymerization reactor is not particularly limited, and may be added in any order, from the viewpoint of good control of the polymerization reaction. Alternatively, from the viewpoint of controlling the peak height index, the polymerization catalyst is added in advance to the volatile solvent and mixed to make the polymerization catalyst dispersed in the volatile solvent. A preferred method is to add the body mixture to the polymerization reactor to initiate the polymerization reaction.

When the polymerization catalyst is added in advance to the volatile solvent and mixed, while a part of the polymerization catalyst is uniformly dispersed in the volatile solvent, the aggregation of the polymerization catalyst, etc., partially remains. The mixing temperature is preferably 20 to 100° C., more preferably 50 to 85° C., and the mixing time is preferably 10 seconds to 4 minutes, more preferably 30 seconds to 3 minutes.

The polymerization temperature for the polymerization reaction is not particularly limited, but is preferably 30 to 100°C, more preferably 40 to 90°C, still more preferably 50 to 85°C. In addition, the polymerization reaction time may be appropriately selected, but it is usually 10 minutes to 12 hours, preferably 30 minutes to 6 hours.

The polymerization reaction is stopped by adding a polymerization terminator such as methanol, an aqueous sodium hydroxide solution, or an aqueous ammonia solution to the polymerization reaction system when a desired polymerization conversion rate is obtained, thereby obtaining a polymer containing a hydrocarbon resin. A combined solution can be obtained.

After the polymerization, a polymerization terminator may be added to remove the solvent-insoluble catalyst residue generated when the polymerization catalyst is deactivated by filtration or the like.

After the polymerization, it is preferable to remove volatile organic compound components such as solvent, unreacted monomers, and low-molecular-weight oligomer components from the polymer solution containing the hydrocarbon resin by steam distillation or the like.

The obtained hydrocarbon resin may be converted into a hydride by subjecting the obtained hydrocarbon resin to a hydrogenation reaction for hydrogenating carbon-carbon double bonds in the hydrocarbon resin, if necessary.
Hydrogenation of the hydrocarbon resin can be carried out by contacting the hydrocarbon resin with hydrogen in the presence of a hydrogenation catalyst.

Although the hydrogenation catalyst is not particularly limited, a nickel catalyst is preferable. In particular, from the viewpoint of high reactivity, a catalyst containing, as a main component, a compound in which nickel as a metal is supported on an inorganic compound supported as a carrier is preferred. Specific examples of supported inorganic compounds as carriers include silica, alumina, boria, silica-alumina, diatomaceous earth, clay, clay, magnesia, magnesia-silica (silica-magnesium oxide), titania, and zirconia. Among them, magnesia-silica is preferable from the viewpoint of reactivity.

<Hot-melt adhesive composition>
The hot-melt pressure-sensitive adhesive composition of the present invention contains the above-described hydrocarbon resin of the present invention.

The hot-melt pressure-sensitive adhesive composition of the present invention can usually be obtained by blending the hydrocarbon resin of the present invention with a thermoplastic elastomer.

The thermoplastic elastomer is not particularly limited, but any thermoplastic elastomer used as a base polymer for hot-melt pressure-sensitive adhesives can be used without limitation. At least one selected from ethylene-vinyl acetate copolymers, styrene thermoplastic elastomers, and polyolefin thermoplastic elastomers is preferred.

The ethylene-vinyl acetate copolymer is not particularly limited, but the vinyl acetate monomer unit content is preferably in the range of 10 to 50% by mass, more preferably in the range of 15 to 40% by mass. Preferably, the range of 15 to 35% by mass is more preferable. As the ethylene-vinyl acetate copolymer, those having a melt flow rate of 1 to 500 g/10 min are preferably used.

The ethylene-vinyl acetate copolymer is available as a commercial product. ” and the like can be suitably used.

In addition, the styrene-based thermoplastic elastomer is not particularly limited, and copolymers such as random, block, and graft copolymers of styrene-based monomers and other monomers that can be copolymerized with styrene-based monomers, and such copolymers. Coalesced hydrogenates and the like include block copolymers comprising at least one aromatic vinyl polymer block and at least one conjugated diene polymer block. Specific examples of such block copolymers include styrene-isoprene diblock copolymers, styrene-isoprene-styrene triblock copolymers, isoprene-styrene-isoprene triblock copolymers, styrene-isoprene-styrene- Isoprene tetrablock copolymers, and mixtures thereof can be suitably used.

The polyolefin-based thermoplastic elastomer is not particularly limited, but includes, for example, an ethylene/α-olefin copolymer. The α-olefin to be copolymerized with ethylene to obtain the ethylene/α-olefin copolymer is not particularly limited. α-olefins having 3 to 20 carbon atoms such as -1-pentene and 1-octene are preferred, α-olefins having 6 to 8 carbon atoms are more preferred, and 1-octene is even more preferred. The α-olefins may be used singly or in combination of two or more.

The content ratio of the α-olefin units in the ethylene/α-olefin copolymer is not particularly limited, but the ratio of the α-olefin units to the total monomer units is preferably 20 to 40 mol%. . As the ethylene/α-olefin copolymer, those having a melt flow rate of 200 to 1500 g/10 min are preferably used.

The blending ratio of the thermoplastic elastomer and the hydrocarbon resin of the present invention in the hot melt adhesive composition of the present invention is not particularly limited, but the hydrocarbon resin is blended with respect to 100 parts by mass of the thermoplastic elastomer. The proportion is preferably 50 to 500 parts by mass, more preferably 80 to 400 parts by mass. When the blending ratio of the hydrocarbon resin is within this range, the adhesive performance of the hot-melt pressure-sensitive adhesive composition will be particularly good.

The hot-melt pressure-sensitive adhesive composition of the present invention may consist solely of the hydrocarbon resin and thermoplastic elastomer of the present invention, but may further contain other components. Other components that can be contained in the hot-melt adhesive composition include waxes, softeners, antioxidants, tackifying resins other than the hydrocarbon resin of the present invention, polymers other than those mentioned above, and heat stabilizers. , UV absorbers, fillers, etc., can be added. It should be noted that the hot-melt pressure-sensitive adhesive composition is preferably a solvent-free composition that does not contain a solvent.

In obtaining the hot-melt pressure-sensitive adhesive composition of the present invention, the method of mixing the above-described hydrocarbon resin, thermoplastic elastomer, and other optional components is not particularly limited. (1) are dissolved in a solvent and uniformly mixed, and then the solvent is removed by heating or the like; Among these methods, melt mixing is preferable from the viewpoint of more efficient mixing. The temperature for melt-mixing is not particularly limited, but is usually in the range of 100 to 200°C.

Since the hot-melt pressure-sensitive adhesive composition of the present invention contains the hydrocarbon resin of the present invention as a tackifying resin, it has excellent holding power and tackiness in a well-balanced manner. Therefore, the hot-melt pressure-sensitive adhesive composition of the present invention can be applied to adhesion of various members by taking advantage of such properties, and is energy-saving, highly productive, and has high holding power. can be performed. The hot-melt pressure-sensitive adhesive composition of the present invention is suitably used, for example, as a pressure-sensitive adhesive for various pressure-sensitive adhesive tapes and labels. Specifically, by forming a pressure-sensitive adhesive layer composed of the hot-melt pressure-sensitive adhesive composition of the present invention on a sheet-like base material that constitutes an adhesive tape or label, the base material and the hot melt of the present invention are formed. It is suitably used as a pressure-sensitive adhesive tape or label comprising a pressure-sensitive adhesive layer comprising a melt pressure-sensitive adhesive composition.

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited only to these Examples. "Parts" and "%" are based on mass unless otherwise specified.
The test methods performed in the present examples and comparative examples are as follows.

[Weight average molecular weight (Mw) of hydrocarbon resin, peak height index]
The hydrocarbon resin is analyzed by gel permeation chromatography to determine the weight average molecular weight (Mw) in terms of standard polystyrene, the peak height [mV] at the peak top, and the peak area [mV × seconds], and A peak height index was calculated according to the following formula (1). In addition, the gel permeation chromatography analysis uses "HLC-8320GPC" manufactured by Tosoh Corporation as a measuring device, uses a column made by connecting three "TSKgel SuperMultiporeHZ" manufactured by Tosoh Corporation, and uses tetrahydrofuran as a solvent. (Hydrocarbon resin dissolved in tetrahydrofuran at a concentration of 1.4% by mass) was measured at a sample flow rate of 100 μL, 40° C., and a flow rate of 1.0 mL/min.
Peak height index = (Peak top height [mV]/Peak area [mV x sec]) x 100 (1)

[Softening point of hydrocarbon resin]
Hydrocarbon resin was measured according to JIS K6863.

[Peeling Adhesive Strength of Hot Melt PSA Composition]
The resulting hot-melt adhesive composition was melt-coated on a 25 μm PET film to a thickness of 20 to 30 μm to obtain a coated sheet. Then, this coated sheet was cut to obtain a test piece. Using the test piece thus obtained, according to PSTC-101 (180° peel adhesion test by the US Adhesive Tape Committee), using a stainless steel plate as the adherend, tensile speed 300 mm / min, The peel adhesion strength (N/10 mm) at room temperature was evaluated by measuring at a temperature of 23°C. The larger the value, the better the peel adhesive strength.

[Loop tack (23°C) of hot-melt adhesive composition]
Using a test piece obtained in the same manner as above, a stainless steel plate was used as the adherend according to PSTC-16 (loop tack test by the US Adhesive Tape Committee), and the test speed was 300 mm / min. Loop tack (N/25 mm) at room temperature (23°C) was evaluated by measuring at a part of 25 x 25 mm at a temperature of 23°C. The larger the value, the better the loop tack strength (initial adhesive strength).

[Holding power of hot-melt adhesive composition]
Using a test piece obtained in the same manner as described above, according to PSTC-107 Procedure A (test method for holding power by the Adhesive Tape Committee of the United States), using a stainless steel plate as an adherend, the adhesive part is 10 × 25 mm. , a load of 1000±5 g, and a temperature of 40° C., the holding power was evaluated by measuring the time (minutes) until peeling. The larger the value, the better the holding power.

[Example 1]
(Manufacture of hydrocarbon resin)
A polymerization reactor was charged with 38.8 parts of cyclopentane as a hydrocarbon solvent, heated to 65° C., then 1.0 part of aluminum chloride as a polymerization catalyst was added, and the temperature (65° C.) was maintained. The aluminum chloride was dispersed in the cyclopentane in such a way that some agglomerates remained by mixing for 2 minutes. Next, after finishing mixing for 2 minutes, 45.0 parts of 1,3-pentadiene, 24.7 parts of cyclopentene, 23.2 parts of isobutylene, 6.0 parts of 1-butene, 2-methyl-2- 0.5 parts butene, 0.3 parts C4-C6 unsaturated hydrocarbons (excluding isobutylene, diisobutylene, 1-butene, and 2-methyl-2-butene), 0.2 parts dicyclopentadiene, 0 cyclopentadiene .1 part and 8.9 parts C4-C6 saturated hydrocarbons and 0.5 parts t-butyl chloride were each passed through separate lines and maintained at temperature (65° C.) for 60 minutes. Polymerization was carried out while continuously adding to the polymerization reactor. After that, an aqueous sodium hydroxide solution was added to the polymerization reactor to stop the polymerization reaction. Table 1 summarizes the types and amounts of the components in the polymerization reactor during the polymerization reaction. Then, a polymer solution containing the hydrocarbon resin, unreacted monomers, etc. was obtained by removing the precipitate formed by the termination of the polymerization by filtration. Then, the polymer solution was placed in a still and heated under a nitrogen atmosphere to remove the polymerization solvent and unreacted monomers to obtain a hydrocarbon resin. Since the amount of unreacted monomer was very small, it can be determined that the monomer composition constituting the obtained hydrocarbon resin is almost the same as the monomer composition used for polymerization (described later. The same applies to Examples 2 to 4 and Comparative Examples 1 to 3.). Then, the weight average molecular weight (Mw), peak height index, and softening point of the obtained hydrocarbon resin were measured according to the methods described above. Table 1 shows the results.

(Preparation of hot-melt adhesive composition)
100 parts of a styrene-isoprene-styrene block copolymer (trade name “Quintac (registered trademark) 3620”, manufactured by Nippon Zeon Co., Ltd.) was put into a stirring blade kneader, and 100 parts of the hydrocarbon resin obtained above was added thereto. Part, softener (trade name "Sunpure N100", naphthenic process oil, manufactured by Nippon Sun Oil Co., Ltd.) 20 parts and antioxidant (trade name "Irganox 1010", manufactured by BASF) 1.5 parts After purging the inside of the system with nitrogen gas, the mixture was kneaded at 160 to 180° C. for 1 hour to prepare a hot-melt adhesive composition. Then, the obtained hot-melt pressure-sensitive adhesive composition was measured for peel adhesive strength, loop tack, and holding power. Table 2 shows the results.

[Examples 2 and 3]
Same as Example 1 except that the types and amounts of components added to the polymerization reactor, the mixing temperature when mixing aluminum chloride as a polymerization catalyst, and the polymerization temperature were changed as shown in Table 1 below. to obtain the hydrocarbon resins of Examples 2 and 3, respectively. Incidentally, styrene not described in Example 1 was mixed with 1,3-pentadiene or the like and subjected to polymerization. Then, the obtained hydrocarbon resin was tested and evaluated in the same manner as in Example 1. Table 1 shows the results.

In addition, a hot-melt pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the hydrocarbon resins of Examples 2 and 3 obtained above were used. Tested and evaluated. Table 2 shows the results.

[Comparative Examples 1 and 2]
Examples except that the types and amounts of components added to the polymerization reactor, the mixing temperature and mixing time when mixing aluminum chloride as a polymerization catalyst, and the polymerization temperature were changed as shown in Table 1 below. Hydrocarbon resins of Comparative Examples 1 and 2 were obtained in the same manner as in Example 1. Diisobutylene and styrene, which are not described in Example 1, were mixed with 1,3-pentadiene and the like and subjected to polymerization. Then, the obtained hydrocarbon resin was tested and evaluated in the same manner as in Example 1. Table 1 shows the results.

Further, a hot-melt adhesive composition was prepared in the same manner as in Example 1 except that the hydrocarbon resins of Comparative Examples 1 and 2 obtained above were used, and each Tested and evaluated. Table 2 shows the results.

[Example 4]
Same as Example 1 except that the types and amounts of components added to the polymerization reactor, the mixing temperature when mixing aluminum chloride as a polymerization catalyst, and the polymerization temperature were changed as shown in Table 3 below. to obtain the hydrocarbon resins of Example 4, respectively. Diisobutylene, which is not described in Example 1, was mixed with 1,3-pentadiene or the like and subjected to polymerization. Then, the obtained hydrocarbon resin was tested and evaluated in the same manner as in Example 1. Table 3 shows the results.

Further, a hot-melt adhesive composition was prepared in the same manner as in Example 1 except that the hydrocarbon resin of Example 4 obtained above was used, and each test and adhesive composition was prepared in the same manner as in Example 1. made an evaluation. Table 4 shows the results.

[Comparative Example 3]
Examples except that the types and amounts of components added to the polymerization reactor, the mixing temperature and mixing time when mixing aluminum chloride as a polymerization catalyst, and the polymerization temperature were changed as shown in Table 3 below. Hydrocarbon resins of Comparative Example 3 were obtained in the same manner as in Example 1. Styrene, which is not described in Example 1, was mixed with 1,3-pentadiene or the like and subjected to polymerization. Then, the obtained hydrocarbon resin was tested and evaluated in the same manner as in Example 1. Table 3 shows the results.

Further, a hot-melt adhesive composition was prepared in the same manner as in Example 1 except that the hydrocarbon resin of Comparative Example 3 obtained above was used, and each test and adhesive composition was prepared in the same manner as in Example 1. made an evaluation. Table 4 shows the results.

From the results of Examples 1 to 3 and Comparative Examples 1 and 2 shown in Tables 1 and 2, and the results of Example 4 and Comparative Example 3 shown in Tables 3 and 4, the weight average molecular weight (Mw) is 500 to 6500 range, a softening point temperature of 50° C. or higher, and a peak height index of 0.5 or lower. The holding power and tackiness were well balanced and excellent.
The holding power and low-temperature performance are also affected by the softening point and the weight average molecular weight (Mw). Contrast examples.

Claims (3)

A hydrocarbon resin comprising an aliphatic monomeric unit or an aliphatic monomeric unit and an aromatic monomeric unit,
The weight average molecular weight (Mw) is in the range of 500 to 6500,
softening point temperature is 50 ° C. or higher,
A peak calculated according to the following formula (1) from the peak height [mV] of the peak top and the peak area [mV × second] in the GPC chart obtained by gel permeation chromatography (GPC) measurement A hydrocarbon resin having a height index of 0.5 or less.
Peak height index = (Peak top height [mV]/Peak area [mV x sec]) x 100 (1) 1,3-pentadiene monomer unit 20 to 70 mass%,
1 to 50% by mass of alicyclic monoolefin monomer units having 4 to 6 carbon atoms,
0 to 50% by mass of acyclic monoolefin monomer units having 4 to 8 carbon atoms,
2. The hydrocarbon resin according to claim 1, comprising 0 to 1% by mass of alicyclic diolefin monomer units and 0 to 40% by mass of aromatic monoolefin monomer units. A hot-melt adhesive composition containing the hydrocarbon resin according to claim 1 or 2.

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