JPH08157794A - Tackifier for styrene-conjugated diene block copolymer and pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE: To obtain a pressure-sensitive adhesive compsn. improved in tack, adhesion, holding power, color tone and smell by incorporating thereinto a specific arom. hydrocarbon resin and a hydrogenation product of a nonarom. hydrocarbon resin. CONSTITUTION: A nonarom. hydrocarbon resin having a softening point of 70 to 110 deg.C is hydrogenated in the presence of 0.1-3wt.% hydrogenation catalyst under a hydrogenation pressure of 30 to 300kg/cm<2> for 1 to 7 hours to obtain a hydrogenation product (B) of the nonarom. hydrocarbon resin, where the hydrogenation product (B) has a no.-average mol.wt. of 300 to 2,000. 10 pts.wt. arom. hydrocarbon resin (A) having a softening point of 140 to 180 deg.C is blended with 5-200 pts.wt. component (B) to obtain a tackifier having a softening point of 80 to 150 deg.C for a styrene-conjugated diene block copolymer. 15-210 pts.wt. tackifier obtd. is blended with 4-20 pts.wt. styrene-conjugated diene block copolymer having a styrene unit/conjugated diene unit wt. ratio of 10/90 to 50/50, and 4-200 pts.wt. oil to obtain the objective a pressure-sensitive adhesive compsn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tackifier and a tackifier composition for styrene-conjugated diene block copolymers.

[0002]

BACKGROUND OF THE INVENTION Conventionally, a styrene-conjugated diene block copolymer has been used as a base polymer, and an aliphatic petroleum resin, an aromatic petroleum resin, a terpene resin, a rosin resin or the like has been used as a tackifier for the base polymer. A pressure-sensitive adhesive composition containing a hydrocarbon resin is known. Generally, such a pressure-sensitive adhesive composition is required to have tack, adhesive strength and holding power as three adhesive characteristics. In order to satisfy these three adhesive properties,
Although the type of tackifier is changed or the blending ratio of the base polymer, tackifier or oil is adjusted, tack and holding power are generally contradictory properties,
There is no known adhesive composition that satisfies all three adhesive properties.

Also, some tackifiers are not preferable in terms of color tone and odor. To improve such color tone and odor, a hydride of a hydrocarbon resin is usually used as a tackifier. However, these hydrogenated resins can only improve the color tone and odor and do not satisfy the three adhesive properties.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a tackifier and a pressure-sensitive adhesive for a styrene-conjugated diene block copolymer which are excellent in tack, adhesive strength and holding power, and also excellent in color tone and odor. It is intended to provide a composition.

[0005]

Means for Solving the Problems In order to solve the above problems, the present inventors have made extensive studies on a tackifier used in a styrene-conjugated diene block copolymer. As a result, an aromatic hydrocarbon resin having a relatively high softening point and a hydride of a non-aromatic hydrocarbon resin having a relatively low softening point or a high hydride of an aromatic hydrocarbon resin should be used in a specific ratio. It was found that the above-mentioned object can be achieved. The present invention has been completed based on this new finding.

More specifically, the present invention relates to a hydrocarbon resin used as a tackifier, wherein an aromatic hydrocarbon resin has a high polarity due to its aromaticity, and is a styrene-conjugated diene block copolymer styrene. The non-aromatic hydrocarbon resin or the high hydride of the aromatic hydrocarbon resin has low polarity because of its non-aromatic nature, and is compatible with the rubber phase (conjugated diene component) of the block copolymer. Since they are compatible with each other, the focus is on the combined use of these hydrocarbon resins. Then, by using a high softening point material as the aromatic hydrocarbon resin to reinforce the styrene phase to maintain the holding force, and to reduce the amount of non-aromatic hydrocarbon resin or aromatic hydrocarbon resin as a high hydride. The problem of color tone and odor is improved by making a hydrocarbon resin having a low softening point a hydride while developing tack by using a softening point object.

That is, the present invention is (1) (a) softening point 1
Styrene-conjugated diene containing 10 parts by weight of an aromatic hydrocarbon resin having a temperature of 40 to 180 ° C. and (b) 5 to 200 parts by weight of a hydride of a non-aromatic hydrocarbon resin having a softening point of 70 to 110 ° C. Tackifier for block copolymer
(2) (a) 10 parts by weight of an aromatic hydrocarbon resin having a softening point of 140 to 180 ° C., and (b) an aromatic carbonization having a softening point of 70 to 110 ° C. in which 80% or more of aromatic rings are hydrogenated. A styrene-conjugated diene block copolymer tackifier comprising 5 to 200 parts by weight of a hydrogen resin, and (3) 15 to 210 parts by weight of the above tackifier, styrene-
The present invention relates to an adhesive composition containing 4 to 200 parts by weight of a conjugated diene block copolymer and 4 to 200 parts by weight of oil.

In the present invention, (a) a softening point of 140 is used as a tackifier for a styrene-conjugated diene block copolymer.
To 180 ° C. aromatic hydrocarbon resin (hereinafter referred to as resin (a)
And (b) a hydride of a non-aromatic hydrocarbon resin having a softening point of 70 to 110 ° C. or an aromatic hydrocarbon resin in which 80% or more of aromatic rings are hydrogenated (hereinafter referred to as resin (b)). Is required to be used.

Examples of the resin (a) include C9 hydrocarbon resin, coumarone-indene resin, styrene polymer and the like.

The C9 hydrocarbon resin means a petroleum resin obtained by cationically polymerizing a C9 fraction (for example, styrene, vinyltoluene, α-methylstyrene, indenes, etc.) obtained by cracking naphtha.

The coumarone-indene resin is generally prepared by copolymerizing coumarone, indene, styrene and the like contained in solvent naphtha (boiling point 150 to 200 ° C.), which is a light fraction in coke oven gas, as a raw material oil. A thermoplastic resin to be obtained, which contains indenes such as indene and methylindene as constituent monomers in an amount of 50% by weight or more, and preferably contains indones and coumarones such as coumarone and methylcoumarone in an amount of 60% by weight or more. Say. Further, if necessary, those modified or adjusted in polymerization degree with styrenes such as styrene and methylstyrene, phenols such as phenol and alkylphenol may be used.

The styrene polymer is styrene,
It is a so-called pure monomer resin obtained by polymerizing a pure monomer such as vinyltoluene, α-methylstyrene, dimethylstyrene by cationic polymerization or the like.

Among the resins (a), C9 type hydrocarbon resins, coumarone-indene resins and the like contain sulfur compounds and the like in a high concentration, so that the sulfur compounds and the like are reduced as much as possible. You may use the existing one. The removal of such sulfur compounds and the like may be carried out at the stage of the feed oil or after the polymerization. Examples of the removal method include an extraction (washing) method with an acid or an alkali, an adsorption method with an adsorbent, a decomposition method with hydrogenation and the like.

The resin (a) has a softening point of 140 to 180 ° C.
And use a relatively expensive one. The softening point of resin (a) is 1
When the temperature is lower than 40 ° C, the reinforcing effect of the styrene phase decreases,
Holding power decreases. If it exceeds 180 ° C., the compatibility with the styrene phase decreases, the glass transition point of the pressure-sensitive adhesive composition rises, and the tack becomes worse. The number average molecular weight of the resin (a) is usually 800 to 3000, preferably 900.
˜1600.

Examples of the non-aromatic hydrocarbon resin which is one of the raw materials of the resin (b) include aliphatic or alicyclic non-aromatic resins such as C5 hydrocarbon resins and terpene resins. Hydrocarbon resins are mentioned.

The C5 hydrocarbon resin is a C4 to C5 fraction obtained by cracking naphtha (for example, pentene, methylbutene, piperelin, cyclopentadiene,
Petroleum resin obtained by cationic polymerization of dicyclopentadiene and the like.

The terpene resin means a resin obtained by polymerizing terpenes such as α-pinene, β-pinene, dipentene and limonene.

For the non-aromatic hydrocarbon resin, an aromatic monomer such as styrene is copolymerized with the C5 hydrocarbon resin or terpene resin at a ratio of less than about 20% by weight of the total amount of the resin. Things are also included.

The production of a hydride of a non-aromatic hydrocarbon resin, which is one of the resins (b), is carried out by appropriately controlling the conditions of the non-aromatic hydrocarbon resin as a raw material in the presence of a hydrogenation catalyst. Adjust the hydrogenation reaction. If the non-aromatic hydrocarbon resin remains unhydrogenated, olefinic double bonds remain and the problems of color tone and odor cannot be improved.

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
It is about 0.1 to 3% by weight, preferably 0.1 to 1% by weight, of the aromatic hydrocarbon resin fat as the raw material resin. 0.1
If it is less than wt%, hydrogenation is difficult to proceed. If it exceeds 3% by weight, it is economically disadvantageous.

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 performed in a state where the 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 catalyst used and the reaction time, the batch type was used as the reaction type, but a flow type (fixed bed type, fluidized bed type, etc.) may be used as the reaction type. it can.

The resin (b) includes 80 aromatic rings of the aromatic hydrocarbon resin (for example, C9 hydrocarbon resin, coumarone-indene resin or styrene copolymer).
It is also possible to use a hydrogenated product of at least%. When the hydrogenation rate of the aromatic ring is less than 80%, it can no longer be said to be a non-aromatic hydrocarbon resin and is compatible with the styrene phase of the styrene-conjugated diene block copolymer to plasticize the styrene phase. And the holding power deteriorates. The aromatic hydrocarbon resin may be hydrogenated under the same conditions as the resin (a) production conditions so that the hydrogenation rate of the aromatic ring is 80% or more. The hydrogenation of the olefinic double bond in the aromatic hydrocarbon resin is easier than the hydrogenation of the aromatic nucleus,
When the hydrogenation rate of the aromatic nucleus is 80% or more, the olefinic double bond is completely hydrogenated, the sulfur compound and the like are hydrolyzed and most of the odorous components are removed.

As the resin (b), one having a relatively low softening point of 70 to 110 ° C. is used. The softening point of resin (b) is 70
If the temperature is less than ℃, the adhesive strength and the holding power are deteriorated. 1
If it exceeds 10 ° C, sufficient tack cannot be obtained. Since the number average molecular weight of the resin (b) varies depending on the composition, it may be appropriately prepared, but is usually 300 to 2000, preferably 350 to 1500. The raw material of the resin (b) also has the same softening point and number average molecular weight as those of the hydride.

The tackifier for styrene-conjugated diene block copolymer of the present invention is 10 parts by weight of the resin (a) and 5 to 200 parts by weight of the resin (b), preferably 10 to 10 parts.
It can be easily prepared by mixing 0 parts by weight. When the amount of the resin (b) used is less than 5 parts by weight, tack is not sufficient, which is not preferable. When the amount of the resin (b) used exceeds 200 parts by weight, the holding power is hardly improved, which is not preferable.

The softening point of the obtained tackifier for a styrene-conjugated diene block copolymer of the present invention containing the resin (a) and the resin (b) is usually 80 to 150 ° C.
The degree is preferably 90 to 130 ° C.

The pressure-sensitive adhesive composition of the present invention comprises the resin (a)
15-210 parts by weight of a tackifier for styrene-conjugated diene block copolymer of the present invention, containing styrene-conjugated diene block copolymer 4-20
It contains 0 parts by weight and 4 to 200 parts by weight of oil.

When the amount of the styrene-conjugated diene block copolymer is less than 4 parts by weight, the coercive force is insufficient and 2
If it exceeds 100 parts by weight, the melt viscosity of the obtained pressure-sensitive adhesive composition becomes high, which is not preferable. Further, when the amount of oil is less than 4 parts by weight, the melt viscosity of the pressure-sensitive adhesive composition becomes high, and when it exceeds 200 parts by weight, the holding power is insufficient, which is not preferable.

The styrene-conjugated diene-based block copolymer of the present invention is a copolymer of styrenes such as styrene and methylstyrene, and conjugated dienes such as butadiene and isoprene, which are appropriately selected according to the purpose of use. It is a polymerized block copolymer. Usually, the weight ratio of styrenes / conjugated dienes is from 10/90 to 50/50. As a preferred specific example of such a block copolymer, for example, the weight ratio of styrenes (S) / budadiene (B) is 10
SBS type block copolymer in the range of 90/50 to 50/50, SIS type block copolymer in which the weight ratio of styrene (S) / isoprene (I) is in the range of 10/90 to 30/70, etc. Can be given. Further, the styrene-conjugated diene-based block copolymer of the present invention also includes the block copolymer obtained by hydrogenating the conjugated diene component.

Examples of the oil include naphthenic oils, paraffinic oils, and plasticizing oils such as aromatic oils. Naphthenic oils and paraffinic oils are preferable from the viewpoint of less reduction in cohesive force. Specific examples thereof include naphthene-based process oil, paraffin-based process oil, liquid polybutene, and the like.

If necessary, the pressure-sensitive adhesive composition of the present invention may further contain additives such as antifoaming agent, thickening agent, filler, antioxidant, waterproofing agent and film-forming aid. be able to.

[0032]

According to the present invention, it is possible to provide a tackifier for a styrene-conjugated diene block copolymer, which is excellent in tackiness, adhesiveness and holding power, and is excellent in color tone and odor. By using the tackifier of the present invention thus obtained, it is possible to provide a pressure-sensitive adhesive composition using the styrene-conjugated diene block copolymer having the above properties. The pressure-sensitive adhesive composition of the present invention can be used in various applications such as various adhesive tapes, labels, automobiles, temporary fixing agents for light electric components, and various assembly applications.

[0033]

The present invention will be specifically described below 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 Resin (b) 100 parts of C5 hydrocarbon resin (“Marukalets T100A”, manufactured by Maruzen Petroleum Co., Ltd.) having a softening point of 100 ° C. and nickel-diatomaceous earth catalyst (JGC Chemical ( Co., Ltd., "N-11
3 ") 2 parts and 1 part of magnesium oxide were charged into an autoclave, hydrogen pressure was 200 kg / cm ² , reaction temperature was 22.
The hydrogenation reaction was carried out under stirring at 5 ° C. for a reaction time of 5 hours. After the reaction was completed, the obtained resin was mixed with cyclohexane 3
It was dissolved in 00 parts and the catalyst was removed by filtration. afterwards,
The filtrate was put in 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 removed by gradually raising the temperature to 200 ° C. and reducing the pressure to 20 torr. , Number average molecular weight 12
63, softening point 98.5 ° C, olefin hydrogenation rate 100
98% of hydrogenated C5-based hydrocarbon resin was obtained.

The hydrogenation rate was calculated from the following formula based on the H-spectral area of the aromatic ring appearing in the vicinity of 7 ppm of 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 tackifier 50 parts of hydrogenated C5 hydrocarbon resin (resin (b)) obtained in the above (1) and C9 hydrocarbon having a softening point of 150 ° C. as resin (a) A tackifier having a softening point of 124 ° C. was prepared by melt mixing 50 parts of a resin (“Neopolymer 150”, manufactured by Nippon Oil Co., Ltd.).

(3) Preparation of adhesive composition SIS type block copolymer ("Califlex TR11
07 ", Shell Chemical Co., Ltd.) and paraffin oil (" DI Process PW90 ", Idemitsu Kosan Co., Ltd.) are melt mixed (the weight ratio of the former to the latter is 30:18) to prepare a rubber-like material. did. 92 parts of this rubber-like material was gradually added to 100 parts of the tackifier prepared in (2) with heating to 180 ° C. with stirring to prepare a pressure-sensitive adhesive composition.

Example 2 The same as (2) of Example 1 except that the melting and mixing amount of the resin (a) and the resin (b) was changed as shown in Table 1 in (2) of Example 1. To prepare a tackifier. Table 1 shows the softening points of the prepared tackifiers. A pressure-sensitive adhesive composition was prepared in the same manner as in (3) of Example 1 using the obtained tackifier.

Example 3 (2) of Example 1 except that the types of resin (a) and resin (b) in Example 2 (2) were changed as shown in Table 1.
A tackifier was prepared in the same manner as in. Table 1 shows the softening points of the prepared tackifiers. A pressure-sensitive adhesive composition was prepared in the same manner as in (3) of Example 1 using the obtained tackifier.

[0040]

[Table 1]

In Table 1, * 1 of the resin (a) is a C9 hydrocarbon resin ("Neopolymer 150", manufactured by Nippon Oil Co., Ltd.).
* 2 of the resin (b) represents a hydride of a C5-based hydrocarbon resin (“Marukalets T100A”, manufactured by Maruzen Petroleum Co., Ltd.), and * 3 represents a C9-based hydrocarbon resin (“Alcon P100”, The hydrogenation rate of the aromatic ring is 90% and the hydride of Arakawa Chemical Industry Co., Ltd. is used.

Comparative Example 1 As a tackifier, a C9 hydrocarbon resin having a softening point of 125 ° C. (“Arcon P125”, aromatic ring hydrogenation rate of 90%,
A pressure-sensitive adhesive composition was prepared in the same manner as in (3) of Example 1 except that Arakawa Chemical Industry Co., Ltd. was used.

Comparative Example 2 As a tackifier, a C5 hydrocarbon resin having a softening point of 100 ° C. (“Marukalets T100A”, manufactured by Maruzen Petroleum Co., Ltd.)
A pressure-sensitive adhesive composition was prepared in the same manner as in (3) of Example 1 except that was used.

Comparative Example 3 As a tackifier, a C9 hydrocarbon resin having a softening point of 150 ° C. (“Neopolymer 150”, aromatic ring hydrogenation rate of 0%,
A pressure-sensitive adhesive composition was prepared in the same manner as in (3) of Example 1 except that Nippon Oil Co., Ltd. was used.

Comparative Examples 4 to 10 In Example 1 (2), two kinds of hydrocarbon resins having different aromaticity or softening point shown in Table 2 are used in place of the resin (a) and the resin (b). A tackifier was prepared in the same manner as in (2) of Example 1 except that it was used. Table 2 shows the softening points of the prepared tackifiers. A pressure-sensitive adhesive composition was prepared in the same manner as in (3) of Example 1 using the obtained tackifier. The hydrocarbon resin was used as the raw material as it was, or the aromatic hydrocarbon resin was used after being hydrogenated as shown in Table 2 in which the aromatic ring hydrogenation rate was as shown in Table 2.

[0046]

[Table 2]

In Table 2, * 1 represents a C9 hydrocarbon resin (“Neopolymer 150”, manufactured by Nippon Oil Co., Ltd.), and * 4.
Is a C5 hydrocarbon resin ("Marukalets T100A",
Maruzen Petroleum Co., Ltd.), * 5 C9 hydrocarbon resin (“Neopolymer 100”, Nippon Oil Co., Ltd.), * 6 C9 hydrocarbon resin (“High Resin RS-
9 ", manufactured by Nippon Oil Co., Ltd., and * 7 represents indene resin (" Uniresin 780 ", manufactured by Nippon Oil Co., Ltd.).

The pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples were evaluated by the following tests. The evaluation results are shown in Table 3.

(Tack) In accordance with JIS Z 0237 method, from the slope having an angle of 30 degrees, No. The steel ball No. 14 was rolled, and the pressure-sensitive adhesive surface placed on a horizontal surface (the pressure-sensitive adhesive composition was applied onto a polyethylene terephthalate film and the coating thickness was 77 μm).
The rolling distance (cm) of the steel ball was measured on the one (hereinafter referred to as PET film) melt-coated so as to have m. The shorter the distance (cm), the better the tack. The measurement atmosphere temperature is 20 ° C.

(Adhesive strength) According to JIS Z 0237 method, the above PET film was adhered to a stainless steel plate as an adherend with an adhesion area of 25 mm using a 2 kg rubber roller.
After pressure-bonding at × 125 mm, it was left at 20 ° C. for 24 hours. After that, a 180 degree peel test was performed with Tensilon to obtain the adhesive strength (kg
/ 25 mm) was measured.

(Holding power) According to JIS Z 0237 method, the PET film and the stainless steel plate were pressure-bonded with a 2 kg rubber roller with an adhesion area of 25 mm × 25 mm, and then left at 20 ° C. for 24 hours. After that, the displacement (mm) between the PET film and the stainless steel plate when a load was applied under the condition of 60 ° C., 2 kg, and 1 hour was measured with a creep tester. The shorter the deviation (mm), the better the holding power.

(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 color tone when the tackifier was melted at 200 ° C. was visually judged by a Gardner standard car.

[0054]

[Table 3]

Claims (5)

[Claims] 1. (a) 10 parts by weight of an aromatic hydrocarbon resin having a softening point of 140 to 180 ° C., and (b) a softening point of 70 to
Non-aromatic hydrocarbon resin hydride at 110 ° C 5 to 20
A tackifier for a styrene-conjugated diene-based block copolymer, containing 0 part by weight. 2. (a) 10 parts by weight of an aromatic hydrocarbon resin having a softening point of 140 to 180 ° C., and (b) 80 aromatic rings.
% Or more hydrogenated, a tackifier for a styrene-conjugated diene block copolymer, containing 5 to 200 parts by weight of an aromatic hydrocarbon resin having a softening point of 70 to 110 ° C. 3. The aromatic hydrocarbon resin is at least one selected from a C9 hydrocarbon resin, a coumarone-indene resin and a styrene polymer.
The tackifier described. 4. The tackifier according to claim 1, wherein the non-aromatic hydrocarbon resin is at least one selected from C5 hydrocarbon resins and terpene resins. 5. 15 to 210 parts by weight of the tackifier according to claim 1, 4 to 200 parts by weight of a styrene-conjugated diene block copolymer, and 4 to 200 of oil.
An adhesive composition containing parts by weight.