JPH0662922B2 - Hot melt adhesive composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is suitable for applications such as packaging, bookbinding, sanitary materials (paper diapers, sanitary napkins), woodworking, furniture edging, carpet lining, etc. The present invention relates to a hot-melt adhesive composition having excellent adhesive strength in a wide temperature range up to.

[Conventional technology]

Using ethylene-vinyl acetate copolymer as a base polymer,
As a hot melt adhesive using a hydrogenated hydrocarbon resin as a tackifier, a method of using a partially hydrogenated aromatic petroleum resin as a tackifier has been conventionally known (Japanese Patent Publication No. 52-
31899). This method improves the compatibility with an ethylene-vinyl acetate copolymer by limiting the hydrogenation rate in the nucleus of the aromatic component in the petroleum resin to 5 to 80% and enhances the adhesive force imparting effect. Is intended.

However, the compatibility is not yet sufficient, and the adhesive force imparting effect is also particularly low temperature region around -20 to 0 ° C and +50.
In the high temperature region around ˜ + 70 ° C., it does not reach a satisfactory level.

[Problems to be Solved by the Invention]

In view of such drawbacks of the prior art, the present invention is a novel hydrogenated hydrocarbon resin that has good compatibility with an ethylene-vinyl acetate copolymer, and has excellent adhesiveness in low and high temperature regions. And the development of a novel hot melt adhesive having excellent adhesive strength using this hydrogenated hydrocarbon resin as a tackifier.

[Means for Solving the Problems]

The present inventors have conducted research to solve the above problems, and as a result, ethylene-vinyl acetate copolymer, hydrogenated coumarone-indene resin which is a novel hydrogenated hydrocarbon resin, and wax as main components. The hot melt adhesive composition to be used is from −20 to 0 ° C. in the low temperature region to +50 to + 70 ° C.
It has been found that the adhesiveness is extremely excellent in a wide temperature range up to the high temperature range, and the present invention has been completed.

The mixing ratio of the ethylene-vinyl acetate copolymer, the hydrogenated coumarone-indene resin and the wax can be appropriately selected according to the purpose of use, but generally 40 to 80 parts by weight of the ethylene-vinyl acetate copolymer, Hydrogenated coumarone
A range of 20 to 80 parts by weight of indene resin and 5 to 40 parts by weight of wax is used.

The type of the ethylene-vinyl acetate copolymer can be appropriately selected according to the purpose of use, but in general, the vinyl acetate content is 19 to 28% by weight and the melt flow rate is 2.5 to 4
A value of 00 dg / min. Is used.

Similarly, the type of wax can be appropriately selected according to the purpose of use, but in general, paraffin wax, microcrystalline wax, carnauba wax, etc. having a melting point of about 53 to 90 ° C. Or 2
A mixture of two or more species is used.

In contrast, the hydrogenated coumarone-indene resin used in the present invention is a raw material coumarone-indene resin containing (a) coumarone, (b) indene or alkylindene and (c) phenol or alkylphenol as an essential constituent monomer. It was done. As the monomer of the raw material coumarone-indene resin, (a) coumarone, (b) indene or alkylindene and (c) phenol or alkylphenol are contained, but these preferably account for 70% by weight or more of the whole, and (b) The indene or alkyl indene preferably accounts for 50% by weight or more of the whole. Other monomers may include styrene, alkyl styrene and the like. Examples of the raw material mixture containing such a monomer include those obtained by desulfurizing and refining a 130 to 200 ° C. fraction obtained by distillation of gas gas oil or coal tar produced during coal carbonization. The desulfurization refining here is preferably carried out to a level of 50 ppm or less of total sulfur concentration, which is less poisoning to the catalyst used during hydrogenation. For example, the method described in JP-A-63-308092 results in no monomer loss. It is preferable because it is few. This is a desulfurization method in which a raw oil is subjected to a distillation treatment and an intermediate catalyst obtained by this distillation treatment is added with an acid catalyst to carry out a light polymerization treatment. The raw material coumarone-indene resin can be produced by directly adding the production conditions of ordinary coumarone-indene resin to the raw material oil obtained by adding styrene or alkylstyrene to the desulfurized refined oil. . That is, as the polymerization catalyst, Bronsted acid such as sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid, boron trifluoride and its complex, Lewis acid such as aluminum chloride, acid clay, activated clay, solid acid such as acidic ion exchange resin. The polymerization conditions vary depending on the type of acid catalyst used, the type and concentration of monomers, the target average molecular weight and softening point, but the amount of catalyst used for the desulfurized feedstock with adjusted components is It is 0.8 to 2% by weight, 1 to 10% by weight in the case of Bronsted acid, and 5 to 50% by weight in the case of solid acid. Reaction temperature is 50-150 ° C, reaction time is 0.5
~ 7 hours is preferred. The polymerized oil is decatalyzed by water washing or alkali washing by a usual method, and the solvent is evaporated by a distillation treatment to obtain a raw material coumarone-indene resin. The raw material coumarone-indene resin thus obtained is hydrogenated to obtain a hydrogenated coumarone-indene resin. Hydrogenation can be carried out by directly removing the decatalyst polymerized oil produced by the above-mentioned raw material coumarone-indene resin by omitting the evaporation treatment, or by using the raw material coumarone-
The indene resin is dissolved again in a solvent such as cyclohexane, methylcyclohexane, ethylcyclohexane or the like, or the resin is dissolved as it is, nickel, palladium,
Hydrogenation is carried out by a conventional method under the conditions of normal temperature to 300 ° C. and normal pressure to 350 kg / cm ² G in the presence of a catalyst containing a metal such as platinum, cobalt, ruthenium, rhodium or the metal oxide. The hydrogenation rate is preferably 90% or more. After the completion of hydrogenation, decomposition products such as hydrogen sulfide are separated and washed, and then the solvent is removed by evaporation or the like to obtain hydrogenated coumarone-indene resin.

A composition prepared by blending ethylene-vinyl acetate copolymer and a wax with this hydrogenated coumarone-indene resin has excellent adhesive strength in a wide temperature range from low temperature to high temperature, and therefore, packaging, bookbinding, sanitary materials. It becomes an excellent hot-melt adhesive composition for use.

[Action]

The hydrogenated coumarone-indene resin used in the hot-melt adhesive composition of the present invention contains coumarone, a phenol or an alkylphenol as a strongly polar oxygen-containing compound in the essential constituent monomer of the raw material coumarone-indene resin,
Further, since it contains indene which is a cyclic aromatic olefin, hydrogenated aromatic petroleum resin mainly containing methylstyrenes as a constituent monomer of the raw material resin and mainly 1,3-pentadiene as a constituent monomer of the raw material resin Hydrogenated aliphatic petroleum resin, mainly hydrogenated dicyclopentadiene resin using dicyclopentadiene as a raw material resin constituent monomer, mainly α-
Compared to conventional hydrogenated hydrocarbon resins such as hydrogenated terpene resins that use terpene-based compounds such as pinene and β-pinene as raw material resin constituent monomers, the compatibility with ethylene-vinyl acetate copolymer is good and the adhesive strength is good. Also excellent in impartability. That is, the ethylene-vinyl acetate copolymer forms a microphase-separated structure having glass transition points of both polyethylene and polyvinyl acetate independently, but a blend containing the hydrogenated coumarone-indene resin of the present invention. The body will have a sharp and well-defined glass transition point in only one place. That is, the hydrogenated coumarone-indene resin of the present invention exerts an excellent compatibilizing agent effect, which is manifested as good adhesiveness of the hot melt adhesive composition of the present invention.

Further, when the hydrogenated coumarone-indene resin of the present invention is hydrogenated so that the nuclear hydrogenation rate of the aromatic component is 90% or more, the thermal stability is also improved. Therefore, this was used as a tackifier resin. The hot melt adhesive composition of the present invention is also imparted with excellent heat resistance such that hue deterioration and skin burr generation in the heated and melted state are small.

〔Example〕

Examples of the present invention will be described below. The characteristics in each example were measured according to the following methods.

1. Adhesion test method (1) Peel test method: According to JIS K 6854 T-type peel test.

(2) Substrate: 0.5 × 25 × 150 mm aluminum plate (Examples 1-4 and Comparative Examples 1-7) 0.05 × 25 × 150 mm aluminum foil (Examples 5-8, Comparative Examples 8-11) ( 3) Measuring atmosphere temperature: 25 ° C. (Examples 1 to 4, Comparative Example 1)
-7) -20 to + 70 ° C (Examples 5-8, Comparative Examples 8-11) (4) Tensile speed: 50 mm / min. (Examples 1-4, Comparative Examples 1- 1)
7) 200 mm / min. (Examples 1 to 4, Comparative Examples 8 to 11) 2. Compatibility Temperature-dynamic viscoelastic properties of a sample prepared by impregnating a blend of ethylene-vinyl acetate copolymer A and hydrogenated hydrocarbon resin into a spring as a support were measured, and the temperature-loss tangent ( Hereinafter referred to as tan δ.) Compatibility was determined from the shape of the curve. The closer the peak of the tan δ curve was to one sharp peak, the better the compatibility was judged to be.

3. Heat stability The hot melt adhesive composition is heated in a hot air oven at 180 ° C.
The thermal stability was evaluated by visually observing the change in hue and the occurrence of skin burr after heating for 10 hours.

Examples 1 to 4 40 parts by weight of ethylene-vinyl acetate copolymer A (manufactured by Mitsui DuPont Polychemical Co., Ltd .: Evaflex 220), 40 parts by weight of hydrogenated coumarone-indene resin, wax (manufactured by Nippon Oil Co., Ltd.) Paraffin wax 145 ° F)
20 parts by weight of each was melt mixed at about 160 ° C. to prepare a hot melt adhesive.

Hydrogenated coumarone-indene resins A, B, C, D used
Table 1 shows the characteristics of each. The properties of this adhesive are shown in Table 2. All had excellent adhesive strength, as well as A, B and C.
The system used was also excellent in thermal stability.

In Figures 1 and 2, the ethylene-
The measurement results of the temperature-tan δ relationship of the vinyl acetate copolymer A homogenous system and the hydrogenated coumarone-indene resin A mixed system were illustrated. The tan δ peak in Fig. 2 becomes one sharp peak, and hydrogenated coumarone-indene resin and ethylene-
Blends of vinyl acetate copolymers have demonstrated very good compatibility.

Comparative Examples 1 to 7 Aromatic petroleum resins A and B obtained by partially hydrogenating a raw material resin containing a methylstyrene derivative as a main component, which does not contain coumarone or phenol as a constituent monomer, and a fully hydrogenated aromatic petroleum resin, similarly. In addition, coumarone and indene are not contained in the constituent monomers, and hydrogenated aliphatic petroleum resin, hydrogen, which is the main component of each raw material resin of 1,3-pentadiene, dicyclopentadiene, α-pinene or β-pinene, In addition to using one kind of hydrogenated hydrocarbon resin as a tackifier resin from among dihydrocyclopentadiene resin, partially hydrogenated aromatic modified terpene resin and fully hydrogenated aromatic modified terpene resin,
A hot melt adhesive was obtained by the same preparation method as in the example.

The adhesive properties are shown in Table 2. All the adhesive strengths were inferior to the adhesives shown in the examples.

Further, FIG. 3 shows a temperature-tan δ curve used for judging compatibility of each hydrogenated hydrocarbon resin, ethylene-vinyl acetate copolymer and partially hydrogenated aromatic petroleum resin B. Compared to the hydrogenated coumarone-indene resin A blend of the present invention shown in FIG. 2, the tan δ peak was broad and the compatibility was poor.

Examples 5 to 8 40 parts by weight of one of ethylene-vinyl acetate copolymers A, B and C, and 1 of hydrogenated coumarone-indene resins A, E and F whose properties are shown in Table 1 40 parts by weight, 10 or 20 parts by weight of wax, about 160 each
A hot melt adhesive was prepared by melt mixing at ℃.

The characteristics of the hydrogenated coumarone-indene resins A, E and F used are shown in Table 1. Adhesive strength, compatibility, and thermal stability were measured according to the methods described above, and the results are shown in Table 3. The compatibility of all the systems was good, showing excellent adhesive strength. Among them, the adhesive strengths of Examples 7 and 8 in the low temperature and high temperature regions were particularly excellent. Moreover, all examples were excellent in thermal stability.

Further, in FIGS. 4, 5, and 6, ethylene-vinyl acetate copolymer C homopolymer, ethylene-vinyl acetate copolymer C / hydrogenated coumarone-indene resin E / wax =
Under temperature dispersion of 40/40/10 blending system (Example 7), ethylene-vinyl acetate copolymer C / partially hydrogenated aromatic petroleum resin C / wax = 40/40/10 blending system (Comparative Example 10). The tan δ characteristics are shown. In Figure 4, PE phase, P
Ta due to each Tg of VAc phase and PE-PVAc compatibility
The nδ peaks were independently observed, and the phase separation structure was confirmed. On the other hand, the tan δ curve in FIG. 5 is a single sharp curve, showing excellent compatibility. On the other hand, in FIG.
The tan δ peak was broad and inferior in compatibility.

Here, each composition system of Examples having excellent compatibility had excellent adhesive force in a wide temperature range from a low temperature to a high temperature centering around Tg (tan δ peak temperature).

Comparative Examples 8 to 11 Hot melt adhesion similar to Examples 5 to 8 except that commercially available partially hydrogenated aromatic petroleum resins A, B and C were used in place of the hydrogenated coumarone-indene resins A, E and F. Prepare the agent,
The characteristics were evaluated.

The results are shown in Table 3. Both systems have compatibility, adhesive strength,
Both were inferior in thermal stability.

[Advantages of the Invention] The hot-melt adhesive composition of the present invention is particularly excellent in adhesiveness in low and high temperature regions as compared with the conventional one using a partially hydrogenated aromatic petroleum resin or the like as a tackifier. It is extremely excellent and becomes a very useful material as a high performance new hot melt adhesive in the fields of packaging, bookbinding, sanitary materials and the like.

[Brief description of drawings]

FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. 6 are graphs showing the relationship between temperature and tan δ.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office internal reference number FI technical display location D06M 15/333 (56) References JP-A-60-51768 (JP, A) JP-A-57- 158276 (JP, A) JP 57-67678 (JP, A) JP 64-51487 (JP, A) JP 52-829 (JP, A) JP 49-99730 (JP, A)

Claims (1)

[Claims] 1. A hot melt adhesive comprising an ethylene-vinyl acetate copolymer, a hydrogenated coumarone-indene resin and a wax as main components, wherein the hydrogenated coumarone-indene resin is (a) coumarone, (b) ) A hot melt adhesive composition characterized by being a hydrogenated coumarone-indene resin obtained by hydrogenating a raw material coumarone-indene resin containing indene or alkylindene and (c) phenol or each constituent monomer of alkylphenol as an essential component. .