JPH08183941A - Tackifier for ethylene-based copolymer and hot melt adhesive composition - Google Patents

Abstract

PURPOSE: To obtain the composition having high adhesive force at a low temperature and good-balanced adhesive force in wide range from a low temperature to room temperature, and excellent color tone, smell and heating stability. CONSTITUTION: This hot melt adhesive composition is a tackifier for an ethylene-based copolymer containing 100 pts.wt. of ethylene-based copolymer and a hydride of a hydroxyl group-containing aromatic-based hydrocarbon resin, and a hydroxyl value of the hydrogenated substance is 220, a hydrogenated content of an aromatic ring is 10-90%, a softening point is 70-115 deg.C, and the aromatic-based hydrocarbon resin contains 50-150 pts.wt. of a tackifier for ethylene-based copolymer containing <=60wt.% indene and 10-100 pts.wt. of wax.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a tackifier for ethylene copolymers and a hot melt adhesive composition.

[0002]

2. Description of the Related Art Hot melt adhesives are widely used in fields such as bookbinding and corrugated cardboard packaging, and since there are few environmental problems, the demand is increasing year by year. In recent years, with the diversification of frozen food applications and the like, hot melt adhesives have been used in such fields as well, but the adhesive strength at low temperatures cannot be said to be sufficient. Also, stable adhesive strength in a wide temperature range from low temperature to room temperature is required. Further, in order to give a feeling of cleanliness, it is required to be close to colorless and odorless also in the field where a hot melt adhesive is used, and heat stability is also a necessary condition from the method of hot melt adhesion.

Conventionally, as hot melt adhesives,
An ethylene-based copolymer is often used as a base polymer and a tackifier is added to the base polymer. As the tackifier, for example, petroleum resin and its hydride are widely used. However, petroleum resin has a bad color tone and odor. Further, petroleum resins generally have good adhesiveness, but they cannot satisfy the adhesiveness at low temperatures. On the other hand, the hydrogenated petroleum resin has good color tone and odor, but its adhesiveness is insufficient.

Further, as the tackifier, a phenol compound-containing hydrocarbon resin is known as having improved adhesiveness. However, the phenol compound-containing hydrocarbon resin is also unsatisfactory in terms of color tone and odor. Further, hydrides of the phenol compound-containing hydrocarbon resin are known. The hydride of the phenolic compound-containing hydrocarbon resin satisfies the color tone and odor, but the adhesive strength at low temperature is not sufficient.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have found that a tackifier for ethylene copolymers, which has high adhesive strength at low temperature and is excellent in color tone, odor and heat stability, or from low temperature to room temperature. Has stable adhesive strength over a wide temperature range,
An object of the present invention is to provide a tackifier for ethylene copolymers which is excellent in color tone, odor and heat stability, and hot melt adhesive compositions thereof.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made extensive studies on tackifiers used for ethylene copolymers. As a result, they have found that the object can be achieved by using a hydride of a hydroxyl group-containing aromatic hydrocarbon resin having a specific softening point or indene content as the tackifier. The present invention has been completed based on this new finding.

That is, the present invention is a tackifier for ethylene copolymers containing a hydride of a hydroxyl group-containing aromatic hydrocarbon resin, wherein the hydroxyl value of the hydride is 20.
It is above, the hydrogenation rate of the aromatic ring is 10 to 90%,
And a tackifier for ethylene-based copolymers having a softening point of 70 to 115 ° C., and a tackifier for ethylene-based copolymers containing a hydride of a hydroxyl group-containing aromatic hydrocarbon resin. The hydroxyl value of the hydride is 20 or more, the hydrogenation rate of the aromatic ring is 10 to 90%, and the aromatic hydrocarbon resin contains indene in an amount of 60% by weight or less. A tackifier for ethylene copolymers, wherein the tackifier for ethylene copolymers comprises a hydride of a hydroxyl group-containing aromatic hydrocarbon resin,
The hydride has a hydroxyl value of 20 or more, an aromatic ring hydrogenation rate of 10 to 90%, a softening point of 70 to 115 ° C., and the aromatic hydrocarbon resin contains indene of 60% by weight. The tackifier for ethylene-based copolymer, which is characterized by containing the following, and 100 parts by weight of the ethylene-based copolymer, and the tackifier 50 according to any one of claims 1 to 3.
The present invention relates to a hot melt adhesive composition containing 150 parts by weight and 10 to 100 parts by weight of wax.

The tackifier for ethylene-based copolymers of the present invention comprises a hydroxyl group-containing aromatic hydrocarbon resin having a specific softening point or a specific indene content and a hydrogenation rate of its aromatic ring of 10%. It is produced by hydrogenation so that the content becomes less than 90%.

The hydroxyl group-containing aromatic hydrocarbon resin is not particularly limited, but generally, a C9 fraction (for example, styrene, vinyltoluene, α-methylstyrene, indene, etc.) obtained by cracking naphtha is used as a phenol compound. The product obtained by cationic polymerization in the presence of can be used.

As the phenols, phenol or alkylphenols such as cresol, xylenol, pt-butylphenol, p-octylphenol and p-nonylphenol can be used. Of these, phenol is preferable in terms of adhesiveness. These phenols may be used alone or in combination of two or more. The amount of phenols used is usually C9
It is about 3 to 35 parts by weight, preferably 3 to 20 parts by weight, relative to 100 parts by weight of the distillate. Incidentally, the hydroxyl value of the obtained hydroxyl group-containing aromatic hydrocarbon resin, during hydrogenation,
It is necessary to decide it in consideration that it may decrease depending on the hydrogenation conditions.

The hydrogenation of the above-mentioned hydroxyl group-containing aromatic hydrocarbon resin is carried out when the hydrogenation rate of the hydroxyl group-containing aromatic hydrocarbon resin is in the above range (the hydrogenation rate of the aromatic ring is 10 to 90%, The olefinic double bond is naturally hydrogenated if the aromatic ring is hydrogenated) so that the raw material hydroxyl group-containing aromatic hydrocarbon resin is used under appropriate conditions in the presence of a hydrogenation catalyst. The hydrogenation reaction is performed by adjusting to.

When the hydrogenation rate of the aromatic ring exceeds 90%, the ratio of the aromatic ring decreases, so that the polarity becomes too small and the compatibility with the ethylene-based copolymer becomes remarkably poor.
The desired adhesive strength cannot be obtained. Further, if it is less than 10%, the heating stability becomes poor. Further, if the olefinic double bond remains, deodorization becomes insufficient. The hydrogenation of the olefinic double bond in the hydroxyl group-containing aromatic hydrocarbon resin is easier than the hydrogenation of the aromatic nucleus, and if the aromatic ring is at least 10% hydrogenated, the olefinic double bond is hydrogenated. The bond is completely hydrogenated, and the sulfur compounds are hydrolyzed and most of the odorous components are removed.

As the hydrogenation catalyst, various ones such as metals such as nickel, palladium, platinum, cobalt, rhodium, ruthenium, molybdenum or metal compounds such as oxides or sulfides thereof can be used. Such a hydrogenation catalyst may be used by supporting it on a carrier such as alumina, silica (diatomaceous earth), carbon or titania, which is porous and has a large surface area. In the present invention, among these catalysts, it is preferable to use the nickel-diatomaceous earth catalyst because it is easy to adjust the hydrogenation ratio within the above range and from the viewpoint of cost. The amount of catalyst used is
Hydroxyl group-containing aromatic hydrocarbon resin, which is a raw material resin, of 0.
It is about 1 to 3% by weight, preferably 0.1 to 1% by weight. If less than 0.1% by weight, hydrogenation is difficult to proceed,
If it exceeds 3% by weight, hydrogenation tends to proceed too much.

The hydrogenation reaction is usually carried out at a hydrogenation pressure of 3
The reaction temperature is usually 1 in the range of 0 to 300 kg / cm ^2.
It is performed in the range of about 50 to 300 ° C. Preferably the hydrogenation pressure is 100-200 Kg / cm ² and the reaction temperature is 2
It is 00-280 degreeC. Hydrogenation pressure is 30 Kg / cm ²
If the reaction temperature is less than 150 ° C or the reaction temperature is less than 150 ° C, hydrogenation is difficult to proceed and the hydrogenation pressure is 300 Kg / c.
If it exceeds m ² or if the reaction temperature exceeds 300 ° C., decomposition occurs and the softening point tends to decrease. The reaction time is usually about 1 to 7 hours, preferably 2 to 7 hours. The hydrogenation reaction is carried out in a state where the raw material hydroxyl group-containing aromatic hydrocarbon resin is melted or dissolved in a solvent. As the solvent, cyclohexane, n-hexane, n-heptane, decalin or the like can be used.

Regarding the amount of the catalyst used and the reaction time, the batch type was used as the reaction type, but the flow type (fixed bed type, fluidized bed type, etc.) may be used as the reaction type. it can.

The hydroxyl value of the obtained hydride of the hydroxyl group-containing aromatic hydrocarbon resin is 20 or more, preferably 20 to 20.
100, more preferably 50 to 100. When the hydroxyl value is less than 20, the effect of improving adhesiveness due to the hydroxyl group is difficult to appear. Since the hydroxyl group-containing aromatic hydrocarbon resin usually has a hydroxyl value of about 100 or less, the hydride has a hydroxyl value of about 100 or less. However, even if the hydroxyl value exceeds 100, there is a particular problem in performance. There is no.

The tackifier for ethylene-based copolymers of the present invention is a hydride of the above specific hydroxyl group-containing aromatic hydrocarbon resin, particularly when low temperature adhesive strength is important.
Moreover, the softening point is 70 ° C to 115 ° C, preferably 70 ° C to
Use the one of 100 ℃. That is, the present invention improves the low temperature adhesive strength by selecting and using a hydride of the specific hydroxyl group-containing aromatic hydrocarbon resin having a relatively low softening point. . When the softening point of the hydride is less than 70 ° C., the holding power becomes poor, and 11
If the temperature exceeds 5 ° C, the adhesive strength at low temperature will be insufficient.

The ethylene-based copolymer tackifier of the present invention, when the importance is attached to the adhesive strength in a wide temperature range from low temperature to room temperature, the specific hydroxyl group-containing aromatic hydrocarbon resin A hydride is used in which the raw material hydroxyl group-containing aromatic hydrocarbon resin contains 60% by weight or less of indene. The indene content in the raw material resin is 6
If it exceeds 0% by weight, the low temperature adhesive strength will be insufficient. The indene content in the aromatic hydrocarbon resin is preferably 5 to 60% by weight, more preferably 20 to 60% by weight, in consideration of the adhesive strength in a wide temperature range from low temperature to room temperature.
Is. In particular, it is preferable to use the aromatic hydrocarbon resin having an indene content of 20 to 45% by weight. That is, the present invention, by selecting and using a hydroxyl group-containing aromatic hydrocarbon resin containing a specific amount of indene as a raw material among hydrides of the specific hydroxyl group-containing aromatic hydrocarbon resin It provides a well-balanced adhesive force in a wide temperature range from low temperature to room temperature. The C9 fraction exemplified above can be used as a component other than indene in the raw material resin.

In the present invention, a hydride of the above specific hydroxyl group-containing aromatic hydrocarbon resin having a softening point of 7
It is particularly preferable that the aromatic hydrocarbon resin has an indene content of 0 to 115 ° C, preferably 70 to 100 ° C, and an indene content of 60% by weight or less, preferably 5 to 60% by weight, from low temperature to room temperature. Has a well-balanced adhesive force over a wide temperature range of up to and including excellent low-temperature adhesive force.

The tackifier for ethylene copolymers of the present invention is a hydride of a hydroxyl group-containing aromatic hydrocarbon resin having the above-mentioned specific softening point, or a hydroxyl group-containing aromatic system containing a specific indene content. Any hydride of a hydrocarbon resin may be used. That is, when specifying the softening point, one kind or two or more kinds of the C9 fraction exemplified above can be used without particular limitation, while when specifying the indene content, the softening point is not limited, and A material having a temperature of 70 ° C to 120 ° C can be used. The number average molecular weight of the hydride of the hydroxyl group-containing aromatic hydrocarbon resin of the present invention is usually 500 to 160.
It is 0, preferably 500 to 900. The raw material (unhydrogenated material) also has a softening point and a number average molecular weight similar to those of hydrides.

The hot melt adhesive composition of the present invention comprises 100 parts by weight of an ethylene copolymer, 50 to 150 parts by weight of the tackifier for the ethylene copolymer, and wax 1.
It contains 0 to 100 parts by weight.

If the tackifier is less than 50 parts by weight,
Sufficient adhesive force cannot be obtained, and if it exceeds 150 parts by weight, sufficient holding force cannot be obtained, which is not preferable. Further, when the amount of wax is less than 10 parts by weight, the melt viscosity of the obtained adhesive composition becomes too high, and when it exceeds 100 parts by weight, sufficient holding power cannot be obtained, which is not preferable.

The ethylene-based copolymer is a copolymer of ethylene and a monomer copolymerizable with ethylene, and those conventionally used in hot melt adhesives can be used. Examples of the monomer copolymerizable with ethylene include vinyl acetate and the like. Vinyl acetate content is usually 20
It is about 45% by weight. The molecular weight is 1 for the melt index (190 ° C., load 2160 g, 10 minutes).
It is preferably about 0 to 400 g / 10 minutes.

The wax used in the hot-melt adhesive can be used in the same manner. For example, paraffin wax, petroleum wax such as microcrystalline wax, Fischer-Tropsch wax, low molecular weight polyethylene and the like can be synthesized. There is wax.

If necessary, additives such as antifoaming agent, thickening agent, filler, antioxidant, waterproofing agent, film-forming aid and the like are added to the adhesive composition of the present invention. be able to.

[0026]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a tackifier for ethylene copolymers, which has a high adhesive strength at low temperature and is excellent in color tone, odor and heating stability. Further, it is possible to provide a tackifier for ethylene copolymers, which has a well-balanced adhesive force in a wide range from low temperature to room temperature and is excellent in color tone, odor and heating stability. By using the tackifier thus obtained, it is possible to provide a hot melt adhesive composition having the above properties. The adhesive composition of the present invention can be used for various applications such as bookbinding, packaging and frozen foods.

[0027]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In each example, parts are based on weight.

Example 1 (1) Production of tackifier Phenol-modified C9 hydrocarbon resin (“Neopolymer E”
-100 (29.8% indene amount) ", manufactured by Nippon Petrochemical Co., Ltd., 150 parts, and nickel diatomaceous earth catalyst (" N-113 ", manufactured by JGC Chemical Co., Ltd.) 1.0 part were charged into the autoclave. The hydrogenation reaction was carried out under the conditions of hydrogen pressure of 200 kg / cm ² , reaction temperature of 250 ° C. and reaction time of 5 hours. After the reaction was completed, the obtained resin was dissolved in 300 parts of cyclohexane and the catalyst was removed by filtration. After that, the filtrate was put into a 1-liter separable flask equipped with a stirring blade, a reflux condenser, a thermometer, a temperature controller and a pressure indicator, and the solvent was gradually heated and depressurized to 200 ° C. and 20 torr. After removal, 98 parts of a hydrogenated phenol-modified C9-based hydrocarbon resin (tackifier) having a number average molecular weight of 600, a softening point of 97.5 ° C. and an aromatic ring hydrogenation rate of 58% was obtained. Table 1 shows the physical properties of the obtained adhesion-imparting agent.

The hydrogenation rate was calculated based on the following formula from the H-spectral area of the aromatic ring appearing at around 7 ppm in ¹ H-NMR of the raw material resin and the obtained hydrogenated resin. Hydrogenation rate = {1- (spectrum area of hydrogenated resin /
Spectral area of raw material resin)} × 100 (%). Also,
The softening point is according to the ring and ball method of JIS K 2531.

(2) Preparation of adhesive composition 40 parts of the tackifier obtained in (1) and a wax (“Hi”
-Mic-1080 ", manufactured by Nippon Seiro Co., Ltd., 20 parts by 1
Melt mixed at 60 ° C. Then, 40 parts of ethylene-vinyl acetate copolymer (“Evaflex EV220”, manufactured by Mitsui DuPont Polychemical Co., Ltd.) was gradually added to prepare an adhesive composition.

Example 2 In (1) of Example 1, as a phenol-modified C9 hydrocarbon resin (“Neopolymer E-120 (inden content 37.5%)”, manufactured by Nippon Petrochemical Co., Ltd.) was used. A tackifier was produced in the same manner as in (1) of Example 1 except that it was used. The physical properties of the obtained tackifier are shown in Table 1. Using this tackifier, an adhesive composition was prepared in the same manner as in (2) of Example 1.

Example 3 In (1) of Example 1, as the phenol-modified C9-based hydrocarbon resin, (“Uniresin 700 (indene amount 6
1.9%) ", manufactured by Nippon Petrochemical Co., Ltd.) was used to produce a tackifier in the same manner as in Example 1 (1). The physical properties of the obtained tackifier are shown in Table 1. Using this tackifier, an adhesive composition was prepared in the same manner as in (2) of Example 1.

Comparative Example 1 In (1) of Example 1, as the phenol-modified C9 hydrocarbon resin, "Uniresin-720 (62.3% indene amount)" manufactured by Nippon Petrochemical Co., Ltd. was used. A tackifier was manufactured in the same manner as in (1) of Example 1 except for the above. The physical properties of the obtained tackifier are shown in Table 1. An adhesive composition was prepared in the same manner as in (2) of Example 1 using the obtained tackifier.

Comparative Example 2 As a tackifier, an unhydrogenated phenol-modified C9 hydrocarbon resin (“neopolymer E-100 (inden content 2
9.8%) ", manufactured by Nippon Petrochemical Co., Ltd.) was used to prepare an adhesive composition in the same manner as in (2) of Example 1.

Comparative Example 3 The procedure of Example 1 was repeated except that a C9 hydrogenated hydrocarbon resin (“ALCON M-100 (inden content: 27.5%)”, manufactured by Arakawa Chemical Industry Co., Ltd.) was used as a tackifier. An adhesive composition was prepared in the same manner as (2).

The adhesive compositions obtained in Examples and Comparative Examples were evaluated by the following tests. Table 2 shows the evaluation results.

(Adhesive Strength) The adhesive composition heated and melted at 180 ° C. was hot-melt coated on aluminum with a bar coder. Adhesive area of this aluminum on the corrugated cardboard 2
After sticking with a 5 mm × 125 mm iron heated to 150 ° C., it was left at 20 ° C. for 24 hours. Then 5
A 180 degree peel test was performed by Tensilon under each temperature of 20 ° C. and 20 ° C. to measure the adhesive strength of the corrugated board.

(Odor) The odor when the adhesive composition was prepared by melting was evaluated according to the following criteria. ○: Almost odorless. Δ: There is a slight odor. X: The odor is severe.

(Color tone) The adhesion-imparting agent was visually evaluated by Gardner standard color.

(Heat stability) 50 g of the adhesive composition was added to 14
The mixture was placed in a 0 cc mayonnaise bottle and allowed to stand in a 180 ° C. normal-air dryer to measure skin-occurrence time.

[0041]

[Table 1]

[0042]

[Table 2]

"Material breakage" in Table 2 means material breakage,
“Member” means partial material destruction. The "members" of Examples 1 and 2 had a high rate of material destruction,
The "member" of Example 3 had a low rate of material destruction.

Claims (4)

[Claims] 1. A tackifier for ethylene-based copolymers, comprising a hydride of a hydroxyl group-containing aromatic hydrocarbon resin, wherein the hydride has a hydroxyl value of 20 or more and hydrogenation of an aromatic ring. The ratio is 10 to 90%, and the softening point is 70 to
115 ° C. A tackifier for ethylene copolymers, which is characterized in that the temperature is 115 ° C. 2. A tackifier for ethylene copolymers, comprising a hydride of a hydroxyl group-containing aromatic hydrocarbon resin, wherein the hydride has a hydroxyl value of 20 or more and hydrogenation of an aromatic ring. Ratio is 10 to 90%, and the aromatic hydrocarbon resin contains indene in an amount of 60% by weight or less, a tackifier for an ethylene copolymer. 3. A tackifier for ethylene copolymers, comprising a hydride of a hydroxyl group-containing aromatic hydrocarbon resin, wherein the hydride has a hydroxyl value of 20 or more and hydrogenation of an aromatic ring. The rate is 10 to 90%, and the softening point is 70 to 11
A tackifier for an ethylene-based copolymer, which is at 5 ° C. and the aromatic hydrocarbon resin contains 60% by weight or less of indene. 4. A hot melt adhesive composition comprising 100 parts by weight of an ethylene-based copolymer, 50 to 150 parts by weight of the tackifier according to claim 1, and 10 to 100 parts by weight of a wax. Stuff.