JP3173841B2 - Hydrogenated petroleum resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel hydrogenated petroleum resin, and more particularly to a novel hot-melt pressure-sensitive adhesive composition having good hue and heat stability and particularly as a tackifier. It relates to useful hydrogenated petroleum resins.

[0002]

2. Description of the Related Art In recent years, thermoplastic elastomers used as a base material of a white (light color) hot melt pressure-sensitive adhesive include styrene block copolymer elastomers such as SBS, SIS and SEBS and white synthetic rubbers such as EVA. It is mainly used in terms of quality, heat resistance and weather resistance.
There is a need to develop useful tackifiers for these elastomers.

[0003] The physical properties required as a tackifier for such a white (light color) hot-melt pressure-sensitive adhesive are hue, heat resistance, weather resistance, compatibility with a base elastomer, and further, when a hot-melt pressure-sensitive adhesive is used. Adhesive properties such as initial adhesive strength (tack), adhesive strength, and holding power.

As the tackifier, naturally occurring resins such as terpene resins and rosin resins have been widely used because of their excellent tackifying effect. However, since it is a natural product, it is unstable in terms of price and supply. In recent years, petroleum resins have tended to be used in place of natural resins,
In particular, hydrogenated petroleum resins are used in terms of hue and heat stability.

[0005] Hydrogenated petroleum resins currently used are hydrogenated products of cyclopentadiene resins and aromatic petroleum resins, but these have insufficient compatibility or adhesion properties with base elastomers. Also, a novel hydrogenated petroleum resin by copolymerization has been known for the purpose of improving these disadvantages.
For example, JP-B-61-1442 discloses a hydrogenated hydrocarbon resin derived from a hydrogenated cyclopentadiene-based component at 20 to 80% by weight and a hydrogenated monovinyl-substituted aromatic component at 20 to 50% by weight. Is disclosed. It is said that other components may coexist, but there is no specific description.

JP-B-61-8849 discloses a partially hydrogenated resin obtained by copolymerizing 70 to 95 parts by weight of a cyclopentadiene compound and 30 to 5 parts by weight of an indene compound. . It is stated that as an indene-based compound, a fraction obtained by fractionation of an aromatic C ₉ fraction by-produced in naphtha decomposition (inden content: 35% or more) can be used. The fraction may contain up to 20% of styrenic monomers in addition to indene, so that the styrene / indene ratio is up to 0.57. In the example, this ratio is 0.38. That is, the amount of styrene relative to indene is small.

However, such a hydrogenated resin could not satisfy all the physical properties required for the tackifier described above.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has been made in view of the above problems. Provided is a hydrogenated petroleum resin having excellent stability and compatibility with a base elastomer and having excellent adhesive properties such as initial adhesive strength (tack), adhesive strength and holding power when used as a hot melt adhesive.

[0009]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the cyclopentadiene-based component (A) is 50 to 90% by weight, the vinyl-substituted aromatic component (B) and Indene aromatic component (C)
A resin obtained by ternary copolymerization of a raw material consisting of 50% by weight and having a weight ratio (B / C) of component (B) to component (C) of 0.6 to 4.0, was hydrogenated; The present invention comprising a hydrogenated petroleum resin having a residual aromatic nucleus content of 2 to 25% by weight, an iodine value of 15 cg / g or less and a softening point of 80 to 150 ° C. has been completed.

That is, the present inventors have studied the resin design of a petroleum resin as a tackifier for a hot-melt pressure-sensitive adhesive. As a result, when the relationship between the structure and the physical properties of the resin is as follows, an excellent effect is exhibited. This led to the completion of the hydrogenated petroleum resin of the present invention.

The compatibility is as follows: 10% by weight or more of an aromatic monomer is copolymerized, and the weight average molecular weight (Mw) of the resin is 50%.
By increasing the number of the polymer regions of at least 00 to 2% by weight or less, preferably 1% by weight or less, the adhesive strength is such that the ratio (Mw / Mn) of the resin between the weight average molecular weight and the number average molecular weight is 2.
When the weight average molecular weight (Mw) is 3000 or more and less than 5,000, the holding power is preferably 1% by weight or more, preferably 2% by weight or more. .

The cyclopentadiene-based component (A) used as a raw material in the present invention includes cyclopentadiene, lower alkyl-substituted cyclopentadiene such as methyl-substituted and ethyl-substituted dimers, trimers and co-dimers thereof. And lower Diels-Alder adducts.

The vinyl-substituted aromatic component (B) also used as a raw material includes styrene, vinyltoluene, divinylbenzene, α-methylstyrene, β-methylstyrene and the like.

Similarly, the indene aromatic component (C) includes indene, lower alkyl-substituted indene such as methyl-substituted and ethyl-substituted.

Next, a method for producing a hydrogenated petroleum resin useful as a tackifier for the white (light color) hot melt pressure-sensitive adhesive of the present invention will be described.

First, the cyclopentadiene component (A) 5
0 to 90% by weight, a total of 10 to 50% by weight of the vinyl-substituted aromatic component (B) and the indene-based aromatic component (C), and a weight ratio (B / C) of the component (B) and the component (C). )
Are prepared in the presence of a solvent at a reaction temperature of 240 to 300 ° C. for a reaction time of 30 to 300
After thermal polymerization in minutes, the solvent and unreacted or low-polymerized components are removed to obtain a resin (I) having a softening point of 60 to 130 ° C. Examples of the solvent used here include pentane, hexane, heptane, benzene, toluene, xylene and the like.

In addition, the resin (I) may be used in addition to the above-mentioned thermal polymerization.
It can also be obtained by a polymerization reaction using a Friedel-Craft type catalyst such as boron trifluoride or aluminum chloride at a temperature of １００100 ° C.

Further, the resin (I) is prepared by a known method, for example, using a catalyst such as nickel, palladium, cobalt, platinum, rhodium or the like in the presence of a diluent in the presence of a diluent at 100-400.
Hydrogenate according to the method of hydrogenation at a temperature of ° C. In the hydrogenation, the hydrogenation ratio of the unsaturated double bond in the resin must be almost completely hydrogenated, that is, the hydrogenation rate of the ethylenically unsaturated group must be 95% or more. Yes, it is necessary to partially hydrogenate the aromatic nucleus, that is, to keep the hydrogenation rate at 25 to 75%.

After hydrogenation, the diluent and low molecular weight substances are removed to obtain a resin having a softening point of 80 to 150 ° C., an iodine value of 15 cg / g or less, and a residual aromatic content of 2 as measured by C ¹³ -NMR. ~ 25% by weight of hydrogenated petroleum resin is obtained. Gardner hue is 1 or less.

In the present invention, in carrying out the above thermal polymerization reaction, the raw material composition must satisfy the conditions of the present invention. That is, the component (A) is 50 to 90% by weight, preferably 50 to 70% by weight, the total of the component (B) and the component (C) is 10 to 50% by weight, preferably 30 to 50% by weight, and The weight ratio of component (B) to component (C) (B /
C) needs to be in the range of 0.6 to 4.0, preferably 1.0 to 3.0.

If the content of the component (A) is less than 50% by weight, the softening point of the resin (I) is insufficient, and if it is more than 90% by weight, that is, the total of the components (B) and (C) is less than 10% by weight. And the base elastomer have poor compatibility.

When the ratio (B / C) is larger than 4.0, the proportion of the high polymer in the resin (I) increases, the compatibility with the base elastomer deteriorates, and the molecular weight distribution Mw / Mn is reduced. When it is widened and hydrogenated and used as a hot melt adhesive, the adhesive strength is not sufficient.

If the ratio (B / C) is smaller than 0.6, the yield during polymerization of the resin (I) decreases, which is uneconomical. Holding power is not enough.

It is considered that these phenomena relating to the molecular weight are caused by a difference in reactivity between the component (B) and the component (C). That is, compared with the indene-based aromatic component (C),
This is because the vinyl-substituted aromatic component (B) has high reactivity and easily produces a high polymer.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. The percentages in Examples and Comparative Examples are based on weight unless otherwise specified.

[0026]

Examples 1 to 3 A 1-liter autoclave was charged with dicyclopentadiene as the component (A), styrene as the component (B) and indene as the component (C) in the proportions shown in Table 1, and toluene as a solvent. Under a nitrogen atmosphere, thermal polymerization was performed at a reaction temperature of 275 ° C. for a reaction time of 100 minutes. After completion of the reaction, the solvent and unreacted or low-polymerized components were removed by distillation to obtain a resin (I) having the properties shown in Table 1.

Subsequently, 80 g of the resin (I), 80 g of cyclohexane as a diluent, and 2.0 g of a nickel-based catalyst (N-113, manufactured by JGC) as a catalyst were charged into a 0.2 liter autoclave. Hydrogen pressure 15
A hydrogenation reaction was performed at 0 kg / cm ² G and 300 ° C.
After completion of the reaction, the diluent was removed by distillation to obtain a hydrogenated petroleum resin. The properties of the hydrogenated petroleum resin are shown in Table 1.

As is clear from Table 1, the hydrogenated petroleum resin obtained by the present invention is excellent in compatibility, and is also excellent in initial tackiness (tack), tackiness, holding power, and economical efficiency. You can see that. Further, the hydrogenated petroleum resin of the example produced under particularly preferable conditions of the ratio (B / C) was very excellent in all the above properties.

[0029]

Comparative Examples 1 to 5 Under the same conditions as in the above examples, except that
Hydrogenated petroleum resins were produced using the raw material compositions shown in Table 1.
The properties of the obtained hydrogenated petroleum resin were as shown in Table 1.

As described above, the hydrogenated petroleum resin obtained in the comparative example could not sufficiently satisfy all the above-mentioned adhesive properties.

[0031]

[Table 1] In Table 1, the hydrogenation rate of the ethylenically unsaturated group, the hydrogenation rate of the aromatic nucleus, the compatibility, the adhesive strength, and the holding power are as follows.

The ethylenic hydrogenation rate (%) of the unsaturated groups = (1-hydrogenated petroleum resin I ₂ divalent / unhydrogenated petroleum resin I
_Divalent) × 100 aromatic nuclei hydrogenation ratio (%) = (1-aromatic content of the aromatic content / unhydrogenated petroleum resins hydrogenated petroleum resin) × 100 compatible: 40 EVA / petroleum resin / wax / 40/2
0 (weight ratio), and observe the transparency of the mixed solution that was sufficiently dissolved and mixed. Adhesive force: 0.1 mm of the molten sample on an aluminum sheet
, And adhered to each other at 160 ° C using a heat sealer. Measured with a tensile tester at a pulling speed of 30 cm / min. Retention: Apply the molten sample to the cardboard adherend and immediately Adhere to the other cardboard adherend. Time until the weight falls under a load of 200 g in a 45 ° C. oven

[0033]

As described above, the present invention has excellent compatibility,
Also provides a hydrogenated petroleum resin particularly useful as a tackifier for a white (light color) hot-melt pressure-sensitive adhesive composition, which is excellent in initial tackiness (tack), tackiness, holding power, and economy. I do.

Continuation of the front page (72) Inventor Kimoge Matsuzaki 8-7-29 Konandai, Konan-ku, Yokohama-shi, Kanagawa (56) References JP-A-2-127409 (JP, A) (58) Fields investigated (Int. Cl ^7, DB name) C08F 8/04 C08F 32/00 -. 32/08 C08F 232/00 - 232/08

Claims (1)

(57) [Claims] 1. A cyclopentadiene-based component (A) 50 to
90% by weight, a total of 10 to 50% by weight of the vinyl-substituted aromatic component (B) and the indene-based aromatic component (C),
And the weight ratio (B / C) of component (B) to component (C) is 0.
Weight obtained by terpolymerizing raw materials having a weight of 6 to 4.0
The ratio of the region where the average molecular weight (Mw) is 5000 or more is doubled
% Or less, the ratio of the region of 3000 or more and less than 5000 is 1
Weight% or more, and the ratio of weight average molecular weight to number average molecular weight
(Mw / Mn) 2.5 or less, hydrogenated resin, residual aromatic content 2 to 25% by weight, iodine value 15c
A hydrogenated petroleum resin having a g / g or less and a softening point of 80 to 150 ° C.