JPH0735501B2 - Hot melt adhesive / adhesive composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a hot-melt adhesive composition having excellent adhesive strength in a wide temperature range from low temperature to high temperature and a hot-melt adhesive composition having excellent holding power. .

[Prior Art] A hot-melt adhesive / adhesive composition containing a block polymer of styrene and a conjugated diene as a base polymer and a hydrocarbon resin as a tackifier resin is commercially available as an aliphatic petroleum oil as a hydrocarbon resin. Resins, aromatic petroleum resins, terpene resins, rosin resins and the like are already known, for example, JP-A-58-52379 and JP-A-58-896.
No. 72, etc.

[Problems to be Solved by the Invention] However, in the case of adhesives, these conventional hot melt viscous / adhesive compositions have reached a satisfactory level of adhesive strength in a wide temperature range from low temperature to high temperature. In addition, in the case of adhesives, there was a problem that the holding power did not reach a satisfactory level.

An object of the present invention is to provide a novel hot melt adhesive / adhesive composition which solves the above problems.

[Means for Solving the Problems] The present inventor has conducted research in order to solve the above-mentioned problems, and mainly uses block polymers of styrenes and conjugated dienes and phenol-modified aromatic hydrocarbon resins. As a component, and the phenol-modified aromatic hydrocarbon resin contains indenes consisting of indene or alkylindene and phenols consisting of phenol or alkylphenol as essential constituent monomer components, and the content of indene relative to all constituent monomers is Of 50-98% by weight and 2-15% by weight of phenols
It has been found that when an adhesive composition is prepared, it becomes a hot melt adhesive having excellent adhesive strength in a wide temperature range from low temperature to high temperature, and also a hot melt adhesive having a satisfactory level of holding power. The present invention has been completed.

Hereinafter, the present invention will be described in detail. The types of block polymers of styrenes and conjugated dienes used in the present invention are
It can be appropriately selected according to the purpose of use, but generally, the ratio of styrene, styrene such as methylstyrene / butadiene, conjugated dienes such as isoprene is 10/90 to 50/50.
Block polymers are used. As a preferred specific example of such a block polymer, for example, an SBS type block polymer of styrene and butadiene having a styrene / butadiene ratio in the range of 10/90 to 50/50 (hereinafter referred to as SB
Abbreviated as S) and the styrene / isoprene ratio is 10/90
~ S / I of styrene and isoprene in the range of 30/70
Examples thereof include thermoplastic rubber such as S-type block polymer (hereinafter abbreviated as SIS).

The phenol-modified aromatic hydrocarbon resin used in the present invention contains indenes consisting of indene or alkylindene and phenols consisting of alkylphenol as an essential constituent monomer component, and the content ratio is based on all constituent monomers. Indenes are 50 to 98% by weight and phenols are 2 to 15% by weight. Further, coumarone and styrene or an alkylstyrene derivative may be optionally contained as other constituent monomer components. The number average molecular weight is
The softening point is preferably in the range of 400 to 2000 and in the range of 30 to 150 ° C. The blending ratio of the phenol-modified aromatic hydrocarbon resin to the block polymer of styrenes and conjugated dienes is 1 with respect to 100 parts by weight of the block polymer.
The range is 0 to 200 parts by weight, preferably 50 to 150 parts by weight.

In the present invention, an aliphatic or alicyclic hydrocarbon resin can be blended, if necessary, for the purpose of imparting tack. For example, terpene-based resin, C ₅ -based petroleum resin, dicyclopentadiene-based petroleum resin, hydrogenated petroleum resin, hydrogenated coumarone-indene resin and the like, the mixing ratio can be appropriately selected according to the purpose, but generally Range of 0 to 200 parts by weight, preferably 0 to 1 with respect to 100 parts by weight of the block polymer
It is recommended to add 50 parts by weight.

In the present invention, a plasticizing oil can be appropriately blended if necessary. The type thereof can be appropriately selected according to the purpose, but it is preferable to use a naphthene-based oil or a paraffin-based oil because the reduction in cohesive force is small, and an aromatic-based oil is not preferable. Examples of such oils include naphthenic process oils, paraffinic process oils, and liquid polybutene. The amount of plasticizing oil blended is 0 with respect to 100 parts by weight of the block polymer.
It is recommended to mix it in the range of up to 200 parts by weight.

The phenol-modified aromatic hydrocarbon resin used in the present invention is a hydrocarbon resin containing indenes and phenols as essential constituent monomer components, which can be produced using the following raw materials. . The indene source may be one containing an alkylindene such as indene or methylindene, for example, a coal-based indene obtained by distillation of gas diesel oil or coal tar produced during coal carbonization, or by cracking petroleum naphtha. Examples include petroleum-based indene obtained by distilling the produced aromatic oil. Further, the phenol source may be any one containing phenol or cresol, an alkylphenol such as xylenol, and for example, coal-based fractionated phenol obtained by distilling coal tar and extracting with alkali, or synthesized by the cumene method or the like. A synthetic phenol etc. can be mentioned.

The phenol-modified aromatic hydrocarbon resin used in the present invention is obtained by adding a styrene or alkylstyrene derivative and a non-olefinic hydrocarbon such as xylene as a solvent to the above-mentioned raw material monomer as a raw material for polymerization. It can be produced by directly applying the usual production conditions of coumarone-indene resin and petroleum resin. 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, solid acid such as acid clay, activated clay, acid ion exchange resin, etc. Can be mentioned.
The polymerization conditions may vary depending on the type and concentration of the acid catalyst used, the target average molecular weight, the softening point, etc., but the amount of the catalyst used relative to the component-adjusted polymerization feedstock is 0.5 to 2% by weight in the case of Lewis acid. , In case of Bronsted acid 1
-10% by weight, preferably 5-50% by weight for solid acids,
The reaction temperature is preferably 50 to 150 ° C, and the reaction time is preferably 0.5 to 7 hours.

The obtained polymerized oil is decatalyzed by water washing or alkali washing by a usual method, and the solvent is evaporated by distillation treatment to obtain a phenol-modified aromatic hydrocarbon resin.

The phenol-modified aromatic hydrocarbon resin thus obtained is blended with a block polymer of styrenes and conjugated dienes and, if necessary, an aliphatic or alicyclic hydrocarbon resin or a plasticizing oil. The prepared composition is a hot-melt adhesive composition exhibiting excellent adhesion in a wide temperature range from low temperature to high temperature, and also a hot-melt pressure-sensitive adhesive composition exhibiting excellent holding power.

[Function] The phenol-modified aromatic hydrocarbon resin used in the hot melt adhesive / adhesive composition of the present invention is compatible with the polystyrene block of the block polymer of styrenes and conjugated dienes, and in the high temperature region of the block. Loss tangent (below
tanδ) and loss elastic modulus (hereinafter referred to as E ″)
To form a third microphase-separated structure having a glass transition temperature near room temperature, which is incompatible with both polystyrene block and polyconjugated diene block, and improves tan δ and E ″ near room temperature. In addition, it does not impair the property of the polyconjugated diene block that tan δ and E ″ are high in the low temperature region.

Therefore, the hot melt adhesive / adhesive composition of the present invention has high tan δ value and E ″ value over a wide temperature range from low temperature to high temperature.

Generally, it is considered that the adhesive force of the adhesive has a positive correlation with the tan δ value, and the holding force of the adhesive has a positive correlation with the E ″ value which is a viscosity term.

Therefore, when the hot-melt viscous / adhesive composition of the present invention is used as an adhesive, it is presumed that excellent adhesive force is exhibited in a wide temperature range from low temperature to high temperature because of the above reason, and the pressure-sensitive adhesive is also used. When used as, it is presumed to exhibit excellent holding power for the above reason.

[Examples] The present invention will be specifically described below based on Examples and Comparative Examples. In each of the examples and comparative examples, the characteristics of the prepared adhesive or pressure-sensitive adhesive were evaluated by the following methods.

(1) Adhesive strength The adhesive strength was estimated according to JIS K 6854 (T-type peeling method).
That is, two pieces of alumina foil (hereinafter, abbreviated as a test piece), which is a test piece on which an adhesive is melt-coated, are superposed on each other on the surfaces coated with the adhesive, and then heated on a hot plate to melt the adhesive layer. After that, using a 2 kg rubber roller, the adhesion area is 25 x 1
A test piece for measurement was prepared by pressure bonding with 25 mm. Then 20-40
During one minute, bend one end of the test piece into a T-shape, attach it to the grip of the tensile tester, draw a curve of the tensile load when peeling at a tensile speed of 200 mm / min on the graph, and draw the curve The average value of each item point was determined and used as the adhesive strength. The measurement atmosphere temperature was set to 7 levels between -20 and + 90 ° C.

(2) Adhesive strength The adhesive strength was measured according to JIS Z 0237 method. That is, a polyester film (hereinafter, abbreviated as a test piece), which is a test piece obtained by melt-coating an adhesive, is bonded to a stainless steel plate (hereinafter, abbreviated as an adherend) which is an adherend by using a 2 kg rubber roller. After crimping with × 125 mm, fold back the play part of the test piece 180 degrees in 20 to 40 minutes, peel off about 25 mm, pull the test piece to the upper chuck of the tester and the adherend to the lower chuck respectively. The scissors were peeled off at a speed of 300 mm / min.
After starting the recording of the recorded chart, draw a line perpendicularly to the 15% part and the 85% part, divide both sections into four equal parts, draw a vertical line, and read the five intersection points with the recording line. Was the adhesive strength. The test was conducted on three test pieces and measured.
The average value of 12 pieces was obtained, and this was proportionally converted per 10 mm width to obtain the adhesive strength.

The measurement atmosphere temperature was set at 5 levels between −10 and + 55 ° C.

(3) Holding power Similarly, the holding power was measured according to JIS Z-0237 method. That is,
The test piece was attached to one end of the adherend so that the area of 25 × 25 mm of the test piece was in contact, and pressure-bonded with a 2 kg rubber roller. After 20 minutes or more, one end of the adherend was hung with a wire, and a 1 kg weight was attached to the one end with a clip so that the test piece hung vertically. The time required for the test piece to fall from the adherend was measured and used as the holding force. All measurement ambient temperatures
It was set to 25 ° C.

(4) Tack Similarly, the tack was measured in accordance with JIS Z-0237 method. That is, when a 10 cm long sticky surface is placed on a slope having an angle of 30 degrees, and the steel ball rolled from the end of the non-sticky runway of 10 cm stops on the sticky surface, the number of the largest steel ball is used. It was a tack. The measurement was performed 4 times, and the average value was taken.
The measurement atmosphere temperature was 25 ° C. in all.

[Examples 1 to 3] 100 parts by weight of SBS (manufactured by Shell Chemical Co., Ltd., trade name: Califlex TR-KX65S, S / B ratio = 28/72) as a base polymer and a phenol-modified aroma as a tackifier resin. 100 parts by weight of group hydrocarbon resin A, B, or C,
Compositions were prepared by melt mixing each at 180 ° C. The properties of the phenol-modified aromatic hydrocarbon resins A, B and C used are as shown in Table 1.

The adhesive strength of the adhesive composition thus prepared was measured according to the method described above. The results are shown in Table 2. The compositions of these examples all had excellent adhesive strength in a wide temperature range from low temperature to high temperature.

[Examples 4 to 6] 100 parts by weight of SIS (manufactured by Shell Chemical Co., Ltd., trade name Califlex TR1107, S / I ratio = 14/86) as a base polymer, and an aliphatic petroleum resin ( 75 parts by weight of Nippon Zeon Co., Ltd., trade name Quinton M-100,
50 parts by weight of one of phenol-modified aromatic hydrocarbon resins F, G, and H, and 50 naphthene-based process oils (Shell Chemical Co., Ltd., trade name Shelf Rex 371N) as plasticizing oil Each part was melt mixed at 180 ° C. to prepare a composition. The properties of the resin used are shown in Table 1.

The pressure-sensitive adhesive strength, holding power, and tack of the pressure-sensitive adhesive composition thus prepared were measured according to the methods described above. The results are shown in Table 3. The compositions of these examples all showed very good holding power. Moreover, the tack and the adhesive strength were not reduced.

Further, FIGS. 1, 2, and 3 show SIS independent system and SIS system, respectively.
The tan δ and loss elastic modulus E ″ characteristics of the / phenol-modified aromatic hydrocarbon resin H = 50/50 blended system and SIS / commercial aromatic petroleum resin C = 50/50 blended system under temperature dispersion were shown.
In Fig. 1, tan δ due to each glass transition temperature (Tg) of polyisoprene phase (PI phase) and polystyrene phase (PS phase),
E ″ peaks were independently observed and a phase-separated structure was confirmed. On the other hand, in FIG.
It was confirmed that a third microphase-separated structure having Tg was formed near room temperature. In addition, the Tg of the PS phase shifted to the high temperature side, and the Tg of the PI phase shifted to the low temperature side. In contrast, the third
The peaks in the figure were different from those in Fig. 2 because the PS phase shifted to the low temperature side and the PI phase shifted to the high temperature side.

The compositions of Examples 4 to 6 showed excellent holding power, but these were compositions using a phenol-modified hydrocarbon resin forming a phase separation system as shown in FIG. Loss modulus E ″ and tan, which are viscous terms in a wide temperature range from low temperature to high temperature
It was considered that the large value of δ contributed to the increase in the holding force.

[Comparative Examples 1 to 6] The tackifier resins were phenol-modified aromatic hydrocarbon resins D and E, aromatic hydrocarbon resins A and B, and commercially available aromatic petroleum resin A (Nippon Petrochemical Co., Ltd.). Manufactured by NEOPOLYMER L-90), the same B (the same name NEOPOLYMER 12)
Compositions were prepared in the same manner as in Examples 1 to 3 except that 0) was used, and the adhesive strength was evaluated.

The results are shown in Table 2. In all cases, the adhesive strength was inferior in a wide temperature range as compared with Examples 1 to 3.

[Comparative Examples 7 to 9] As the tackifier resin, aromatic hydrocarbon resin A, commercially available aromatic petroleum resin B (manufactured by Nippon Petrochemical Co., Ltd., trade name Neopolymer 120), and C (the same, Neopolymer) are used. One of 100)
Compositions were prepared in the same manner as in Examples 4 to 6 except that the adhesive strength, the holding power, and the tack were evaluated.

The results are shown in Table 3. In each case, the holding power was inferior to that of the example.

[Advantages of the Invention] The hot-melt adhesive / adhesive composition of the present invention has an adhesive strength larger than that of a conventional one in the case of an adhesive in a wide temperature range from low temperature to high temperature. Further, in the case of an adhesive, the holding power is extremely large. For this reason, packaging, assembly, tape,
It is an extremely useful material as a high-performance hot melt adhesive / adhesive in the field of labels and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1, FIG. 2 and FIG. 3 are graphs showing the relationship between temperature and tan δ and loss elastic modulus E ″.

Claims (1)

[Claims] 1. A hot-melt adhesive / adhesive composition mainly comprising a block polymer of styrenes and conjugated dienes and a phenol-modified aromatic hydrocarbon resin, wherein the phenol-modified aromatic hydrocarbon is used. The resin contains indenes consisting of indene or alkylindene as an essential constituent monomer and phenols consisting of phenol or an alkylphenol, and the content of indenes is 50 to 92% by weight based on all the constituent monomers.
And 2 to 15% by weight of phenols, a hot melt adhesive / adhesive composition.