JP2003268331A - Hot melt adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot melt adhesive composition excellent in creep resistance. <P>SOLUTION: The hot melt adhesive composition consists of (a) 5-94 wt.% of an ethylenic copolymer, (b) 5-90 wt.% of an adhesiveness-imparting resin, and (c) 1-40 wt.% of a polyolefin wax which has a number-average molecular weight (Mn) of 400-2,500 as determined by gel permeation chromatography (GPC) and a melting point of 90-130°C as determined by differential scanning calorimetory (DSC). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a hot melt adhesive composition having excellent heat resistance and creep resistance.

[0002]

BACKGROUND OF THE INVENTION Conventional hot melt adhesives can be used without a solvent, and since they have an economic advantage in terms of process such as instant bonding and high speed bonding, they can be used for bookbinding. It is used in large quantities mainly in fields such as packaging and woodworking. The hot melt adhesive composition has flexibility,
From the viewpoint of heat stability and price, ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer (EEA) and other ethylene-based copolymers, and styrene block copolymers are widely used as base polymers. There is. As the tackifying resin blended with these base polymers, rosin-based and terpene-based natural resins and various petroleum resins are used.

For example, Japanese Patent Laid-Open No. 2-55783 discloses a hot-melt adhesive excellent in heat stability, high temperature adhesive strength and room temperature adhesive strength by using a specific rosin phenol resin as a tackifying resin. Compositions are disclosed. In addition, in the market, heat resistant adhesiveness,
There was a strong demand for hot melt adhesives with excellent resistance to heat creep. As a result of studying under such conventional techniques, the present inventors have found that a composition comprising an ethylene copolymer, a tackifying resin and a polyolefin wax is excellent in heat resistant adhesiveness and heat resistant creep.

[0004]

OBJECT OF THE INVENTION It is an object of the present invention to provide a hot melt adhesive composition having excellent heat creep resistance.

[0005]

SUMMARY OF THE INVENTION The hot melt adhesive composition according to the present invention comprises (a) an ethylene copolymer of 5 to 94% by weight and (b).
Tackifying resin 5 to 90% by weight, and (c) the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is in the range of 400 to 2500, and measured by a differential scanning calorimeter (DSC). Melting point 90 ~
Polyolefin wax in the range of 130 ° C 1-4
It is characterized by comprising 0% by weight.

It is preferable that the polyolefin wax is produced by a metallocene catalyst.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The hot melt adhesive composition according to the present invention will be specifically described below. The hot melt adhesive composition according to the present invention comprises (a) an ethylene copolymer, (b) a tackifying resin, and (c) a polyolefin wax. [(A) Ethylene Copolymer] The ethylene copolymer (a) used in the present invention is not particularly limited as long as it has been conventionally used as a base polymer of a hot melt adhesive composition. , A monocarboxylic acid vinyl ester and an acrylic acid ester 1
One or a copolymer of two or more polar monomers can be preferably used.

The ethylene copolymer (a) preferably contains 10 to 60% by weight, particularly 15 to 45% by weight, of a polar monomer unit such as monocarboxylic acid vinyl ester and acrylic acid ester. The melt flow rate of the ethylene copolymer (a) is usually 0.1 to 1000.
g / 10 minutes, preferably 1 to 500 g / 10 minutes. The melt flow rate is ASTMD-123.
8 is measured under the conditions of 190 ° C. and a load of 2160 g.

[(B) Tackifying Resin] Specific examples of the tackifying resin (b) used in the present invention include alicyclic hydrogenated tackifiers, rosins, modified rosins, esterified products thereof, and aliphatic resins. Petroleum resin, alicyclic petroleum resin,
Aromatic petroleum resin, copolymerized petroleum resin of aliphatic and aromatic components, low molecular weight styrene resin, isoprene resin,
Alkyl, phenol resin, terpene resin, coumarone
Examples thereof include indene resin, and rosin, rosin ester, petroleum resin, terpene resin and the like are preferably used.
In the present invention, these tackifying resins may be used alone or in combination of two or more.

[Polyolefin Wax (c)] In the conventional hot melt adhesive composition, as wax, for example, synthetic wax such as polyethylene wax, polypropylene wax, atactic polypropylene wax; petroleum wax such as paraffin wax and micro wax. Natural waxes such as wood wax, carnauba wax, and beeswax are generally used. However,
The synthetic wax and the petroleum wax have poor compatibility with the ethylene copolymer and the tackifying resin. In addition, the above petroleum wax generally has a low melting point and has a problem of poor heat resistance and adhesion. The above-mentioned natural wax has a large variation in physical properties, and when stored for a long period of time, there is a problem that it is oxidized and deteriorated by oxygen in the air.
Therefore, in the present invention, the following polyolefin wax is used as the wax.

The polyolefin wax used in the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. The α-olefin is preferably an α-olefin having 3 to 10 carbon atoms, and more preferably propene having 3 carbon atoms, 1-butene having 4 carbon atoms, 1-pentene having 5 carbon atoms, and carbon. Examples thereof include 1-hexene having 6 atoms, 4-methyl-1-pentene, 1-octene having 8 carbon atoms, and the like, preferably propene, 1-butene, 1-hexene, and 4-methyl-1-pentene. .

The polyolefin wax (c) has a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 400 to 2500, preferably 500 to 1500, more preferably 500 to 1000.
Is in the range. When the number average molecular weight of the polyolefin wax (c) is within the above range, the viscosity of the hot melt adhesive composition is appropriate and the heat resistant adhesiveness is excellent.

The polyolefin wax (c) has a melting point of 90 to 130 ° C. measured by a differential scanning calorimeter (DSC),
It is preferably in the range of 100 to 130 ° C. When the melting point of the polyolefin wax (c) is within the above range, a hot melt adhesive composition having excellent heat resistant adhesiveness can be obtained. The polyolefin wax (c) has an acetone extraction content of 0 to 20% by weight, preferably 0 to 15% by weight.

When the amount of acetone extracted in the polyolefin wax (c) is within the above range, the heat-resistant adhesion tends to be excellent, and when it exceeds 20% by weight, the amorphous component which becomes a sticky component at room temperature increases in the polyolefin wax. Therefore, the heat resistant adhesiveness tends to decrease. The amount of acetone extracted is measured as follows.

A Soxhlet extractor (made of glass) using a filter (No. 84, made by ADVANCE),
Acetone 200m in the lower round bottom flask (300ml)
1 is charged and extraction is performed in a hot water bath at 70 ° C. for 5 hours. 10 g of the first wax is set on the filter. The polyolefin wax (c) has an Mw / Mn of 3 or less, preferably 2.9 or less, and more preferably 2.8 or less.

When Mw / Mn is within the above range, it is possible to obtain a hot melt adhesive composition having a small amount of low molecular weight components and excellent heat resistance adhesiveness. The polyolefin wax (c) has a crystallization temperature measured by a differential scanning calorimeter (DSC) (Tc (° C.), a temperature decreasing rate of 2 ° C./min.).
And the density measured by the density gradient tube method (D (kg / m ³ ))
The following formula (I) 0.501 × D-366 ≧ Tc (Ia) is preferable, and the following formula (Ia) 0.501 × D-366.5 ≧ Tc (Ia) is more preferable. It is desirable to satisfy the formula (Ib) 0.501 × D-367 ≧ Tc (Ib).

When the relationship between the crystallization temperature (Tc) and the density (D) of the polyolefin wax (c) satisfies the above equation, the comonomer composition of the polyolefin wax (c) becomes more uniform, resulting in the polyolefin wax (c). The sticky component of) tends to decrease. The polyolefin wax (c) is preferably an ethylene / α-olefin copolymer obtained from ethylene and propene and / or 1-butene, and has a density of 850 to 9
80 kg / m ³ , preferably 890-970 kg / m ³ ,
More preferably, it is desirable to be in the range of 900 to 950 kg / m ³ .

The polyolefin wax (c) is a solid at room temperature and becomes a low viscosity liquid at 80 to 120 ° C. or higher. The polyolefin wax (c) as described above is
For example, it can be produced using the following metallocene-based catalyst comprising a metallocene compound of a transition metal selected from Group 4 of the periodic table and an organoaluminumoxy compound and / or an ionizable ionic compound.

(Metallocene Compound) The metallocene compound forming the metallocene catalyst is a metallocene compound of a transition metal selected from Group 4 of the periodic table, and a specific example is a compound represented by the following general formula (1). Is mentioned. M ¹ Lx (1) where M ¹ is a transition metal selected from Group 4 of the periodic table, x
Is the valence of the transition metal M ² , and L is a ligand.

Examples of the transition metal represented by M ¹ include zirconium, titanium and hafnium. L is a ligand that coordinates to the transition metal M ^1, and at least one of the ligands L is a ligand having a cyclopentadienyl skeleton, and a ligand having this cyclopentadienyl skeleton. The ligand may have a substituent. Examples of the ligand L having a cyclopentadienyl skeleton include, for example, a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, n- or i-propylcyclopentadienyl group, n-, i-, sec- or t
-Alkyl- or cycloalkyl-substituted cyclopentadienyl group such as butylcyclopentadienyl group, dimethylcyclopentadienyl group, methylpropylcyclopentadienyl group, methylbutylcyclopentadienyl group, methylbenzylcyclopentadienyl group And further examples include an indenyl group, a 4,5,6,7-tetrahydroindenyl group, and a fluorenyl group. Hydrogen of the ligand having the cyclopentadienyl skeleton may be substituted with a halogen atom or a trialkylsilyl group.

When the metallocene compound has two or more ligands having a cyclopentadienyl skeleton as the ligand L, the two ligands having a cyclopentadienyl skeleton among them are It may be bonded via an alkylene group such as ethylene and propylene; a substituted alkylene group such as isopropylidene and diphenylmethylene; a silylene group or a substituted silylene group such as a dimethylsilylene group, a diphenylsilylene group and a methylphenylsilylene group.

Ligands other than those having a cyclopentadienyl skeleton (ligands having no cyclopentadienyl skeleton) L are hydrocarbon groups having 1 to 12 carbon atoms,
Alkoxy group, aryloxy group, sulfonic acid-containing group (-
SO ₃ R ¹ ), a halogen atom or a hydrogen atom (where R is
¹ is an alkyl group, an alkyl group substituted with a halogen atom, an aryl group, an aryl group substituted with a halogen atom, or an aryl group substituted with an alkyl group. ) And the like.

(Example-1 of metallocene compound) When the metallocene compound represented by the above general formula (1) has, for example, a transition metal having a valence of 4, more specifically, it is represented by the following general formula (2). To be done. R ² _k R ³ _l R ⁴ _m R ⁵ _n M ¹ (2) Here, M ¹ is a transition metal selected from Group 4 of the periodic table, R ²
Is a group (ligand) having a cyclopentadienyl skeleton, R
³ , R ⁴ and R ⁵ are each independently a group (ligand) having or not having a cyclopentadienyl skeleton.
k is an integer of 1 or more, and k + l + m + n = 4.

Examples of the metallocene compound in which M ¹ is zirconium and at least two ligands having a cyclopentadienyl skeleton are included are shown below. Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium dichloride, bis (1-methyl-3-butylcyclopentadienyl) zirconium bis (trifluoromethanesulfonate), bis (1, 3-dimethylcyclopentadienyl)
Zirconium dichloride, bis (n-butylcyclopentadienyl) zirconium dichloride and the like.

Among the above compounds, a compound in which the 1,3-position-substituted cyclopentadienyl group is replaced with a 1,2-position-substituted cyclopentadienyl group can also be used. Further, as another example of the metallocene compound, the above general formula (2)
In, at least two of R ² , R ³ , R ⁴ and R ⁵ ,
For example, R ² and R ³ are groups (ligands) having a cyclopentadienyl skeleton, and these at least two groups are bound to each other via an alkylene group, a substituted alkylene group, a silylene group or a substituted silylene group. It is also possible to use a bridge type metallocene compound. At this time R
⁴ and R ⁵ are independently the same as the ligand L other than the above-mentioned ligand having a cyclopentadienyl skeleton.

Examples of such bridge-type metallocene compounds are ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium. Dichloride,
Methyl phenyl silylene bis (indenyl) zirconium dichloride etc. are mentioned.

(Example-2 of metallocene compound) As another example of the metallocene compound, a metallocene compound represented by the following general formula (3) and described in JP-A-4-268307 can be mentioned.

[0028]

[Chemical 1]

Here, M ¹ is a transition metal of Group 4 of the periodic table, and specific examples thereof include titanium, zirconium and hafnium. R ¹¹ and R ¹² may be the same or different and each is a hydrogen atom; an alkyl group having 1 to 10 carbon atoms; an alkoxy group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms; a carbon atom. An aryloxy group having 6 to 10 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; an arylalkyl group having 7 to 40 carbon atoms; 7 to 40 carbon atoms
Or an arylalkenyl group having 8 to 40 carbon atoms; or a halogen atom, and R ¹¹ and R ¹² are preferably chlorine atoms.

R ¹³ and R ¹⁴ may be the same or different and each is a hydrogen atom; a halogen atom; an optionally halogenated alkyl group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms. _{^{; -N (R 20) 2,}} -SR 20,
-OSi (R ²⁰⁾ _3, a -Si (R ^{2 0)} ₃ or -P (R ²⁰⁾ ₂ group. Here, R ²⁰ is a halogen atom, preferably a chlorine atom; an alkyl group having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms; or an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms. R ¹³ and R ¹⁴ are particularly preferably hydrogen atoms.

R ¹⁵ and R ¹⁶ are the same as R ¹³ and R ¹⁴ except that they do not contain a hydrogen atom, and they may be the same or different from each other, preferably the same. R ¹⁵
And R ¹⁶ is preferably an optionally halogenated alkyl group having 1 to 4 carbon atoms, specifically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
Examples thereof include trifluoromethyl and the like, with methyl being particularly preferred.

In the above general formula (3), R ¹⁷ is selected from the following group.

[0033]

[Chemical 2]

= BR^{twenty one}, = AlR^{twenty one}, -Ge-, -Sn
-, -O-, -S-, = SO, = SO ₂, = NR^{twenty one}, =
CO, = PR^{twenty one}, = P (O) R^{twenty one}Such. M²Is silicon,
Germanium or tin, preferably silicon or germanium
It is Ni. Where R^{twenty one}, R^{twenty two}And R^{twenty three}Are each other
May be the same or different, hydrogen atom; halogen source
Child; alkyl group having 1 to 10 carbon atoms; 1 to carbon atom
10 fluoroalkyl groups; ants having 6 to 10 carbon atoms
Group; fluoroaryl group having 6 to 10 carbon atoms; charcoal
Alkoxy group having 1 to 10 elementary atoms; 2 to 10 carbon atoms
Alkenyl group of 7 to 40 carbon atoms arylalkyl
Group; arylalkenyl group having 8 to 40 carbon atoms;
Is an alkylaryl group having 7 to 40 carbon atoms.
"R^{twenty one}And R^{twenty two}Or "R^{twenty one}And R^{twenty three}Is each
May form a ring with the atoms to which they bind
Yes.

Further, R ^{17 is, = CR 21 R 22, =} SiR 21
^{R 22, = GeR 21 R 22} , -O -, - S -, = SO, = P
R ²¹ or = P (O) R ²¹ is preferred. R ¹⁸
And R ¹⁹ may be the same or different from each other, and R ²¹
The same thing as is mentioned. m and n may be the same or different from each other and are 0, 1 or 2, preferably 0 or 1, and m + n is 0, 1 or 2, preferably 0 or 1.

Examples of the metallocene compound represented by the above general formula (3) include the following compounds. rac-
Ethylene (2-methyl-1-indenyl) ² -zirconium dichloride, rac-dimethylsilylene (2-
Methyl-1-indenyl) ² -zirconium-dichloride and the like. These metallocene compounds can be produced, for example, by the method described in JP-A-4-268307.

(Example-3 of Metallocene Compound) As the metallocene compound, a metallocene compound represented by the following general formula (4) can be used.

[0038]

[Chemical 3]

In the formula, M ³ represents a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium, hafnium or the like. R ²⁴ and R ²⁵ may be the same or different from each other, and are a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, oxygen. A containing group, a sulfur containing group, a nitrogen containing group or a phosphorus containing group is shown.

R ²⁴ is preferably a hydrocarbon group,
Especially methyl, ethyl or propyl having 1 to 3 carbon atoms
Is preferably an alkyl group of R ²⁵ is preferably a hydrogen atom or a hydrocarbon group, and particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl or propyl.

R ²⁶ , R ²⁷ , R ²⁸ and R ^{29, which} may be the same or different, are each a hydrogen atom, a halogen atom,
Hydrocarbon group having 1 to 20 carbon atoms, 1 to 20 carbon atoms
The halogenated hydrocarbon group of is shown. Of these, a hydrogen atom, a hydrocarbon group or a halogenated hydrocarbon group is preferable. Even if at least one set of R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , R ²⁸ and R ²⁹ is combined with the carbon atom to which they are bonded to form a monocyclic aromatic ring. Good.
When there are two or more hydrocarbon groups or halogenated hydrocarbon groups in addition to the group forming an aromatic ring, they may be bonded to each other to form a ring. When R ²⁹ is a substituent other than an aromatic group, it is preferably a hydrogen atom.

X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, or a carbon number of 1 to 2.
A hydrocarbon group of 0, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group or a sulfur-containing group is shown. Y is
Divalent hydrocarbon group having 1 to 20 carbon atoms, 1 carbon atom
20 divalent halogenated hydrocarbon groups, divalent silicon-containing groups, divalent germanium-containing groups, divalent tin-containing groups,
-O -, - CO -, - S -, - SO -, - SO 2 -, -
^{NR 30 -, - P (R} 30) -, - P (O) (R 30) -, - BR 30
- or -AlR ³⁰ - (provided that, R ³⁰ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms) shows a.

In the formula (4), R ²⁶ and R ²⁷ , R ²⁷ and R
²⁸ , R ²⁸ and R ²⁹ include a monocyclic aromatic ring formed by bonding at least one pair to each other, and examples of the ligand coordinated to M ³ include those represented by the following formulae. To be

[0044]

[Chemical 4]

(In the formula, Y is the same as that shown in the above formula.) (Example-4 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (5) is used. You can also

[0046]

[Chemical 5]

In the formula, M ³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R
²⁸ and R ²⁹ are the same as those in the above general formula (4).
Of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ , two groups including R ²⁶ are preferably alkyl groups, and R ²⁶ and R ²⁸ , or R ²⁸ and R ²⁹ are alkyl groups. preferable. This alkyl group is preferably a secondary or tertiary alkyl group. Further, this alkyl group may be substituted with a halogen atom or a silicon-containing group, and examples of the halogen atom and the silicon-containing group include the substituents exemplified for R ²⁴ and R ²⁵ .

Of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ , the groups other than the alkyl group are preferably hydrogen atoms. Two groups selected from R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ may be bonded to each other to form a monocyclic or polycyclic ring other than an aromatic ring. Examples of the halogen atom include those similar to the above R ²⁴ and R ²⁵ .

Examples of X ¹ , X ² and Y include the same ones as described above. Specific examples of the metallocene compound represented by the above general formula (5) are shown below. rac-dimethylsilylene-bis (4,7-dimethyl-1-indenyl)
Zirconium dichloride, rac-dimethylsilylene-
Bis (2,4,7-trimethyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2,4,6-trimethyl-1-indenyl) zirconium dichloride and the like.

In these compounds, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can be used. The transition metal compound is
Usually used as a racemate, but R type or S type can also be used. (Example-5 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (6) can also be used.

[0051]

[Chemical 6]

In the formula, M ³ , R ²⁴ , X ¹ , X ² and Y are
It is the same as the general formula (4). R ²⁴ is preferably a hydrocarbon group, and particularly preferably an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl or butyl. R ²⁵ represents an aryl group having 6 to 16 carbon atoms. R ²⁵ is preferably phenyl or naphthyl. The aryl group is a halogen atom or has 1 to 20 carbon atoms.
Or a halogenated hydrocarbon group having 1 to 20 carbon atoms may be substituted.

X ¹ and X ² are preferably a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms.
Specific examples of the metallocene compound represented by the above general formula (6) are shown below. rac-dimethylsilylene-bis (4
-Phenyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4)
-Phenyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4)
-(Α-naphthyl) -1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4- (β-naphthyl) -1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2
-Methyl-4- (1-anthryl) -1-indenyl)
Zirconium dichloride, etc. Further, in these compounds, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can also be used.

(Example-6 of Metallocene Compound) As the metallocene compound, a metallocene compound represented by the following general formula (7) can also be used. LaM ⁴ X ³ ₂ (7) Here, M ⁴ is a metal of Group ⁴ of the periodic table or a lanthanide series. La is a derivative of the delocalized π-bonding group, and is a group that imparts a constrained geometry to the metal M ⁴ active site. X ³ may be the same or different from each other, and are a hydrogen atom, a halogen atom, a hydrocarbon group having 20 or less carbon atoms,
It is a silyl group containing 20 or less silicon or a germanyl group containing 20 or less germanium.

Among these compounds, the compound represented by the following formula (8) is preferable.

[0056]

[Chemical 7]

M ⁴ is titanium, zirconium or hafnium. X ³ is the same as that described in the general formula (7). Cp is a substituted cyclopentadienyl group which is π-bonded to M ⁴ and has a substituent Z. Z is oxygen, sulfur, boron or an element of Group 4 of the periodic table (eg silicon, germanium or tin).

Y is a ligand containing nitrogen, phosphorus, oxygen or sulfur, and Z and Y may form a condensed ring. Specific examples of the metallocene compound represented by the formula (8) are shown below. (Dimethyl (t-butylamide)
(Tetramethyl-η ⁵ -cyclopentadienyl) silane)
Titanium dichloride, ((t-butylamido) (tetramethyl- [eta] ⁵ -cyclopentadienyl) -1,2-ethanediyl) titanium dichloride and the like. In addition, in this metallocene compound, a compound in which titanium is replaced with zirconium or hafnium can be given.

(Example 7 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (9) can be used.

[0060]

[Chemical 8]

M ³ is a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably zirconium. R ³¹ may be the same as or different from each other, and at least one of them is an aryl group having 11 to 20 carbon atoms, an arylalkyl group having 12 to 40 carbon atoms, or 13 to 30 carbon atoms.
40 arylalkenyl groups, alkylaryl groups having 12 to 40 carbon atoms or silicon-containing groups, or at least two adjacent groups of the groups represented by R ³¹ together with the carbon atoms to which they are bonded, It forms one or more aromatic or aliphatic rings. In this case, the ring formed by R ^31, it is 4 to 20 carbon atoms in all including carbon atoms to which R ³¹ is bonded.

Aryl group, arylalkyl group, arylalkenyl group, alkylaryl group and aromatic ring,
R ³¹ other than R ³¹ that forms an aliphatic ring is a hydrogen atom,
It is a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a silicon-containing group. R ^{32 s} may be the same as or different from each other, and each is a hydrogen atom, a halogen atom, or a carbon number of 1 to 1.
0 alkyl group, C 6-20 aryl group, C 2-10 alkenyl group, C 7-40
Is an arylalkyl group, an arylalkenyl group having 8 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group.

In addition, at least two adjacent groups among the groups represented by R ³² may form a single or plural aromatic ring or aliphatic ring together with the carbon atom to which they are bonded. In this case, the ring formed by R ³² is
Carbon atoms in all including carbon atoms to which R ³² is bonded is from 4 to 20, aromatic ring, R ³² other than R ³² that forms an aliphatic ring is a hydrogen atom, a halogen atom, a carbon atom It is an alkyl group or a silicon-containing group of the numbers 1 to 10.

In the group formed by the two groups represented by R ³² forming one or more aromatic rings or aliphatic rings, a fluorenyl group has a structure represented by the following formula. included.

[0065]

[Chemical 9]

R ³² is preferably a hydrogen atom or an alkyl group, particularly a hydrogen atom or methyl, ethyl,
It is preferably a hydrocarbon group having 1 to 3 carbon atoms of propyl. A preferable example of the fluorenyl group having R ³² as the substituent is a 2,7-dialkyl-fluorenyl group. In this case, the alkyl group of 2,7-dialkyl has 1 to 1 carbon atoms. And the alkyl group of 5. R ³¹ and R ³² may be the same or different from each other.

R ³³ and R ³⁴ may be the same as or different from each other, and are the same as the above hydrogen atom, halogen atom, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 20 carbon atoms, and carbon atom. Alkenyl group having 2 to 10 carbon atoms, arylalkyl group having 7 to 40 carbon atoms, and 8 carbon atoms
40 arylalkenyl groups, C 7-40 alkylaryl groups, silicon-containing groups, oxygen-containing groups, sulfur-containing groups, nitrogen-containing groups or phosphorus-containing groups. At least one of R ³³ and R ³⁴ is preferably an alkyl group having 1 to 3 carbon atoms.

X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, and a carbon number of 1 to 2.
It is a hydrocarbon group of 0, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group or a nitrogen-containing group, or a conjugated diene residue formed from X ¹ and X ² . The conjugated diene residue formed from X ¹ and X ² is preferably a residue of 1,3-butadiene, 2,4-hexadiene, 1-phenyl-1,3-pentadiene or 1,4-diphenylbutadiene. , These residues may be further substituted with a hydrocarbon group having 1 to 10 carbon atoms.

X ¹ and X ² are preferably a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a sulfur-containing group. Y is a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group, a divalent Tin-containing group, -O-, -CO-, -S-,
_{-SO -, - SO 2 -,} - NR 35 -, - P (R 35) -, -
^{P (O) (R 35)} -, - BR 35 - or -AlR ³⁵ - (provided that, R ³⁵ is a hydrogen atom, a halogen atom, carbon atom 1-2
A hydrocarbon group of 0 and a halogenated hydrocarbon group of 1 to 20 carbon atoms).

Among these divalent groups, those in which the shortest linking part of -Y- is composed of 1 or 2 atoms are preferable. R ³⁵ is a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. Y is preferably a divalent hydrocarbon group having 1 to 5 carbon atoms, a divalent silicon-containing group or a divalent germanium-containing group, more preferably a divalent silicon-containing group, and an alkyl group. Particularly preferred is silylene, alkylarylsilylene or arylsilylene.

(Example-8 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (10) can also be used.

[0072]

[Chemical 10]

In the formula, M ³ is a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably zirconium. R ³⁶
May be the same or different from each other, and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a silicon-containing group, It is an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group. The alkyl group and alkenyl group may be substituted with a halogen atom.

Of these, R ³⁶ is preferably an alkyl group, an aryl group or a hydrogen atom, and particularly, a methyl, ethyl, n-propyl, i-propyl hydrocarbon group having 1 to 3 carbon atoms, phenyl, It is preferably an aryl group such as α-naphthyl or β-naphthyl, or a hydrogen atom. R ^{37 s} may be the same or different from each other, and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 2 to 2 carbon atoms.
An alkenyl group having 10 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, an arylalkenyl group having 8 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, A nitrogen-containing group or a phosphorus-containing group. The alkyl group, aryl group, alkenyl group, arylalkyl group, arylalkenyl group and alkylaryl group may be substituted with halogen.

Of these, R ³⁷ is preferably a hydrogen atom or an alkyl group, and particularly preferably a hydrogen atom or 1 to 10 carbon atoms of methyl, ethyl, n-propyl, i-propyl, n-butyl or tert-butyl. It is preferably a hydrocarbon group of 4. Further, R ³⁶ and R ³⁷ may be the same as or different from each other. One of R ³⁸ and R ³⁹ is an alkyl group having 1 to 5 carbon atoms, and the other is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. , A silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group.

Of these, one of R ³⁸ and R ³⁹ has 1 carbon atom such as methyl, ethyl or propyl.
It is preferable that it is an alkyl group of ~ 3 and the other is a hydrogen atom. X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, or a carbon atom number of 1 to 20.
Hydrocarbon group, halogenated hydrocarbon group having 1 to 20 carbon atoms, oxygen-containing group, sulfur-containing group or nitrogen-containing group,
Alternatively, it is a conjugated diene residue formed from X ¹ and X ² . Of these, halogen atoms or carbon atoms of 1 to
It is preferably 20 hydrocarbon groups.

Y is a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group,
Divalent tin-containing group, -O-, -CO-, -S-, -SO
_{-, - SO 2 -, -} NR 40 -, - P (R 40) -, - P (O)
^{(R 40) -, - BR} 40 - or -AlR ⁴⁰ - (wherein, R
⁴⁰ represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms).

Of these, Y is 2 having 1 to 5 carbon atoms.
It is preferably a divalent hydrocarbon group, a divalent silicon-containing group or a divalent germanium-containing group, more preferably a divalent silicon-containing group, and an alkylsilylene, an alkylarylsilylene or an arylsilylene. Is particularly preferable. The metallocene compounds described above may be used alone or in combination of two or more. The metallocene compound may be diluted with a hydrocarbon or a halogenated hydrocarbon before use.

(Organoaluminum Oxy Compound) The organoaluminum oxy compound may be a known aluminoxane or a benzene-insoluble organoaluminum oxy compound. Such known aluminoxane is specifically represented by the following formula.

[0080]

[Chemical 11]

Here, R is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group or a butyl group, preferably a methyl group or an ethyl group, particularly preferably a methyl group, and m
Is an integer of 2 or more, preferably 5 to 40. Aluminoxane is an alkyloxyaluminum unit represented by the formula (OAl (R ′)) and an alkyloxyaluminum unit represented by the formula (OAl (R ″)) (here, R ′).
And R ″ can exemplify the same hydrocarbon group as R, and R ′ and R ″ represent different groups. ) May be formed from a mixed alkyloxyaluminum unit. The organoaluminum oxy compound may contain a small amount of an organic compound component of a metal other than aluminum.

(Ionized Ionic Compound) Examples of the ionized ionic compound (which may be referred to as an ionic ionized compound or an ionic compound) include Lewis acids, ionic compounds, borane compounds and carborane compounds. it can. Examples of the Lewis acid include compounds represented by BR ₃ (R is fluorine, a phenyl group which may have a substituent such as a methyl group or a trifluoromethyl group, or fluorine.). Specific examples of the Lewis acid include trifluoroboron, triphenylboron,
Tris (4-fluorophenyl) boron, Tris (3,
5-difluorophenyl) boron, tris (4-fluoromethylphenyl) boron, tris (pentafluorophenyl) boron, tris (p-tolyl) boron, tris (o-tolyl) boron, tris (3,5-dimethylphenyl) Examples include boron.

Examples of the ionic compounds include trialkyl-substituted ammonium salts, N, N-dialkylanilinium salts, dialkylammonium salts and triarylphosphonium salts. Examples of the trialkyl-substituted ammonium salt as the ionic compound include triethylammonium tetra (phenyl) boron, tripropylammonium tetra (phenyl) boron, tri (n-butyl) ammonium tetra (phenyl) boron and the like. Examples of the dialkyl ammonium salt as the ionic compound include di (1-propyl) ammonium tetra (pentafluorophenyl) boron and dicyclohexylammonium tetra (phenyl) boron.

As the ionic compound, triphenylcarbenium tetrakis (pentafluorophenyl) is used.
Examples thereof include borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, and ferrocenium tetra (pentafluorophenyl) borate. As the borane compound, decaborane (9); bis [tri (n-butyl) ammonium] nonaborate, bis [tri (n-butyl) ammonium]
Examples thereof include salts of metal borane anions such as decaborate and bis [tri (n-butyl) ammonium] bis (dodecahydride dodecaborate) nickelate (III).

Examples of the carborane compound include 4-carbanonaborane (9), 1,3-dicarbanonaborane (8), bis [tri (n-butyl) ammonium] bis (undecahydride-7-carbaundecaborate). ) Salts of metal carborane anions such as nickelate (IV). Such ionized ionic compounds may be used alone or in combination of two or more. The organoaluminum oxy compound and the ionized ionic compound can also be used by supporting them on the carrier compound.

When forming the metallocene catalyst, the following organoaluminum compounds may be used together with the organoaluminum oxy compound and / or the ionizable ionic compound. (Organoaluminum compound) The organoaluminum compound used as necessary has at least 1 in the molecule.
Compounds can be used with a number of Al- carbon bond Such compounds, for example an organoaluminum compound represented by the following general formula ^{(11), (R 6)} m Al (OR 7) n H p X 4 _q ... (11) (In the formula, R ⁶ and R ⁷ may be the same as or different from each other, and are a hydrocarbon group containing usually 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. X ⁴ is halogen. It is an atom.m
Is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is a number satisfying 0 ≦ q <3, and m + n + p + q
= 3. ) Examples thereof include complex alkylated products of a Group 1 metal represented by the following general formula (12) and aluminum.

(M ⁵ ) Al (R ⁶ ) ... (12) (In the formula, M ⁵ is Li, Na or K, and R ⁶ is the same as R ^{6 in the} general formula (11).) Polymerization) The polyolefin wax used in the present invention can be obtained by homopolymerizing ethylene in a normal liquid phase or by copolymerizing ethylene and α-olefin in the presence of the above metallocene catalyst. At this time, a hydrocarbon solvent is generally used, but an α-olefin may be used as a solvent. The respective monomers used here are as described above.

Polymerization methods are as follows: suspension polymerization in which a polyolefin wax is polymerized in the state of being present as particles in a solvent such as hexane, gas phase polymerization in which a solvent is not used, and polyolefin wax at a polymerization temperature of 140 ° C. or higher. It is possible to perform solution polymerization in which is polymerized in the state of coexisting with a solvent or alone, and among them, solution polymerization is preferable in terms of economy and quality.

The polymerization reaction may be carried out by either a batch method or a continuous method. When carrying out the polymerization batchwise, the catalyst components are used in the concentrations described below. The concentration of the metallocene compound in the polymerization system is usually 0.00005 to 0.1 mmol / liter (polymerization volume), preferably 0.0001 to 0.05 mmol / liter.

The organoaluminum oxy compound has a molar ratio of aluminum atom to transition metal in the metallocene compound in the polymerization system (Al / transition metal) of 1 to 1000.
It is supplied in an amount of 0, preferably 10-5000. The ionized ionic compound is 0.5 to 2 in terms of the molar ratio of the ionized ionic compound to the metallocene compound in the polymerization system (ionized ionic compound / metallocene compound).
It is supplied in an amount of 0, preferably 1-10.

When an organoaluminum compound is used, it is usually used in an amount of about 0 to 5 mmol / liter (polymerization volume), preferably about 0 to 2 mmol / liter. The polymerization reaction usually has a temperature of −20 to −20.
+ 200 ° C., preferably 50 to 180 ° C., more preferably 70 to 180 ° C. and pressure exceeding 0 and 7.8 MPa
(80 kgf / cm ² , gauge pressure) or less, preferably 0
Over 4.9 MPa (50 kgf / cm ² , gauge pressure) or less.

At the time of polymerization, ethylene and optionally an α-olefin are supplied to the polymerization system in such an amount ratio that a polyolefin wax having the above-mentioned specific composition can be obtained. A molecular weight modifier such as hydrogen may be added during the polymerization. When the polymerization is carried out in this manner, the produced polymer is usually obtained as a polymerization liquid containing the polymer, and thus the polyolefin wax according to the present invention can be obtained by treating the polymer in a usual manner.

For the polymerization reaction, it is particularly preferable to use a catalyst containing a metallocene compound shown in (Example-6 of metallocene compound). Furthermore, in the present invention, it is preferable to produce an ethylene / α-olefin copolymer. [Composition] The hot melt adhesive composition according to the present invention,
The ethylene copolymer (a) as described above, the tackifying resin (b), and the polyolefin wax (c) are used, and the ethylene copolymer (a) is 5 to 94% by weight, preferably 10 to 70% by weight. , Tackifying resin (b) 5 to 90
% By weight, preferably 10-70% by weight, 1-40% by weight of the polyolefin wax (c), preferably 15-
It is contained in a proportion of 30% by weight (however, (a),
The total amount of (b) and (c) is 100% by weight. ).

When the content ratio of the ethylene copolymer (a) is in the above range, the compatibility, the adhesive strength, the melt viscosity, the open time, the solidification rate and the like tend to be excellent. If the content of the ethylene copolymer (a) is less than 5% by weight, cold-adhesion resistance may decrease, and if it exceeds 94% by weight, melt viscosity becomes too high and workability deteriorates. is there.

When the content ratio of the tackifying resin (b) is within the above range, the compatibility, adhesive strength, melt viscosity, open time, solidification rate and the like tend to be excellent.
If the content of the ethylene copolymer (a) is less than 5% by weight, the effect of improving the physical properties may not be obtained, and if it exceeds 90% by weight, either the heat-resistant adhesiveness or the cold-resistant adhesiveness may decrease. There is.

When the content ratio of the above-mentioned polyolefin wax (c) is within the above range, the compatibility, the adhesive strength, the melt viscosity, the open time, the solidification rate and the like tend to be excellent. Content of polyolefin wax (c) is 1
If it is less than wt%, the effect of improving the physical properties may not be obtained, and if it exceeds 40 wt%, the melt viscosity may become too low and the workability may deteriorate.

The hot melt adhesive composition of the present invention comprises
Antioxidants, weathering stabilizers, fillers, plasticizers, oils and the like can be added depending on the purpose of use. To the hot melt adhesive composition of the present invention, a (co) polymer similar to the polyolefin wax (c) and having a number average molecular weight in the range of 2500 to 5000 should be added. You can This (co) polymer has a viscosity of 1 at 180 ° C. measured by a Brookfield viscometer.
000 to 7000 cPs, and the density measured by the density gradient tube method is preferably in the range of 880 to 920 g / cm ³ .

Addition of such a (co) polymer can improve the adhesion to a nonpolar surface. The hot melt adhesive composition of the present invention comprises (a) an ethylene copolymer, (b) a tackifying resin, and (c) a polyolefin wax, and if necessary, the above-mentioned various additives in a predetermined mixing ratio. It is supplied to a mixer such as a Brabender, heated and melt-mixed, and then it is formed into a desired shape, for example, granular,
It can be prepared by molding into flakes, rods, or the like.

The hot-melt adhesive composition of the present invention is heated and melted to be applied to an object to be coated such as cloth, kraft paper, aluminum foil and polyester film by a usual method to form an adhesive layer. And then used. The hot melt adhesive composition of the present invention can be used for assembling and sealing paper containers such as cardboard and cartons; manufacturing automobile parts, electric / electronic parts, sanitary goods, books, magazines and the like.

[0100]

The hot melt adhesive composition according to the present invention is excellent in heat-resistant adhesiveness and heat-resistant creep resistance.

[0101]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples.

[0102]

[Synthesis Example 1] (Synthesis of polyolefin wax (I))
A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 950 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been sufficiently replaced with nitrogen.
ml was charged, and hydrogen was introduced until the pressure reached 0.7 MPa (gauge pressure). Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.004 mmol, (t-butylamido) dimethyl (tetramethyl- Polymerization was started by press-fitting 0.02 mmol of η ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. Then, the total pressure was kept at 2.9 MPa (gauge pressure) by continuously supplying only ethylene, and polymerization was carried out at 150 ° C. for 20 minutes. After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, Mn was 510 and density was 9
20 g of an ethylene polymer (polyolefin wax (I)) having a melt viscosity of 50 kg / cm ³ and a melt viscosity of 101 ° C. measured by DSC was obtained.

[0104]

[Synthesis example 2] (Synthesis of polyolefin wax (II))
A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 950 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been sufficiently replaced with nitrogen.
ml and propylene 50 ml, hydrogen was added to 0.1
It was introduced until it reached 5 MPa (gauge pressure). Next, after raising the temperature in the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.00
Polymerization was initiated by press-fitting 4 mmol and 0.02 mmol of (t-butylamido) dimethyl (tetramethyl-η ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. Then, the total pressure was kept at 2.9 MPa (gauge pressure) by continuously supplying only ethylene, and polymerization was carried out at 150 ° C. for 20 minutes. After stopping the polymerization by adding a small amount of ethanol into the system, unreacted ethylene and propylene were purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, 33 g of an ethylene / propylene copolymer (polyolefin wax (II)) having a Mn of 2050, a density of 927 kg / cm ³ and a melt viscosity of 105 ° C. measured by DSC was obtained.

[0106]

EXAMPLES AND COMPARATIVE EXAMPLES The components shown in Table 1 were used in the proportions shown in the table and melt mixed at 180 ° C. to prepare hot melt adhesive compositions. The hot melt adhesive composition thus obtained was tested as follows. The results are shown in Table 1.

(Adhesion test piece preparation method) The hot melt adhesive was applied using a hot melt open time tester (manufactured by Asahi Kasei Corp.) at a coating temperature of 180 ° C. and a coating amount of 0.0.
The lamination was performed under the conditions of 3 g / cm ² , coating speed of 7.5 m / min, open time of 2 seconds, and press load of 2 kg. (Size: 50 mm × 100 mm) (Adhesion test adherend) As the adherend, a general-purpose cardboard (K ″ liner) was used. Adhesive force measurement method The test piece prepared by the adhesion test piece preparation method is 25 mm x 100 m
After cutting into m size, T-peel strength (adhesive strength) was measured by a tensile tester at a crosshead speed of 100 mm / min. The measurement was performed at 20 ° C.

(Heat-resistant adhesiveness measuring method (peeling adhesion breaking time)) The test piece prepared by the adhesion test piece preparing method was used as a base material in a T-type peeling state, and a load of 300 g / 25 mm was hung to 65 ° C. In the set oven, the time during which the adhesive of the base material failed to withstand the weight and the adhesion failed (the weight dropped) was evaluated as the peel adhesion failure time. (Melt viscosity) Measured with a Brookfield viscometer.

[0109]

[Table 1]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Toyoda             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc.             Inside the company F term (reference) 4J040 BA182 BA202 CA092 DA022                       DA031 DA102 DB022 DK012                       DN032 EB032 JB01

Claims (2)

[Claims] 1. An ethylene copolymer (a) 5 to 94% by weight, a tackifying resin (b) 5 to 90% by weight, and
(C) Gel permeation chromatography (GP
The number average molecular weight (Mn) measured in C) is 400 to 250.
A hot melt adhesive composition comprising 1 to 40% by weight of a polyolefin wax having a melting point of 90 to 130 ° C. as measured by a differential scanning calorimeter (DSC). 2. The hot melt adhesive composition according to claim 1, wherein the polyolefin wax is produced with a metallocene catalyst.