JPS6281470A - Hot-melt adhesive composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent adhesion durability and heat stability, by mixing a specified copolymer, a tackifier, and a crystalline PP. CONSTITUTION:5-70wt% copolymer (A) which contains 35wt% or less styrene units and is obtained by the hydrogenation of a styrene-isoprene-styrene block copolymer or a styrene-butadiene-styrene block copolymer, is mixed with 10-70wt% tackifier (B) (e.g., a terpene phenol resin) having a softening point of 60-150 deg.C, 10-75wt% crystalline PP (C) (e.g., a powdery PP prepared by polymerizing propylene or by decomposing an isotactic PP) having a number- average molecular weight of 20,000 or less, and if necessary, another polymer (e.g., an ethylene-propylene copolymer), a wax (e.g. a paraffin wax), an extender oil (e.g., a liquid rosin), an aggregate (e.g., talc), etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Purpose of the invention "Field of industrial application" The present invention is directed to polyolefin resins, metals, etc. that are widely used in various fields of industry.

This product relates to hot melt adhesive compositions that have excellent adhesive strength, adhesive durability such as adhesive heat resistance and heat creep resistance, and thermal stability during heat melting, and are used for various purposes including adhesion of electrical parts. It can be widely used in various industrial fields.

[Conventional technology - 1 Conventional technology has been used for adhesion of electrical parts such as fixing TV yokes, adhesion of seals for industrial filters, adhesion of automobile parts, etc.It has excellent heat resistance and is mainly used for adhesion of metal materials. Dimer acid-based polyamide adhesives are widely used as hot melt adhesives.

However, these polyamides have problems such as thermal deterioration due to the amide group during melt heating, the need to preheat the adhesive, and poor cold resistance. Furthermore, it has the fatal drawback of not having adhesive strength to plastics such as polyolefin resins that have recently been widely used for such purposes.

Adhesives using ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, atactic polypropylene, etc. as the paste resin are also being considered as other hot-melt adhesives, but none of them have good adhesion heat resistance or durability. There is no material that fully satisfies the properties such as special properties and adhesion to polyolefin resins.

``Problem to be Solved by the Invention-1 The present invention solves the above-mentioned problem of conventional hot melt adhesives, and solves the above-mentioned problem of conventional hot melt adhesives. Provides hot melt adhesives that have excellent adhesion, heat resistance, and cold resistance to plastics such as plastics, and have excellent workability with melt coating equipment and stability when melting and heating. It is.

(o) Structure of the Invention ``Means for Solving the Problems'' The present inventors have conducted extensive studies on compositions that provide excellent hot melt adhesives free from the above-mentioned problems, namely, that the present invention contains the following six components. The present invention relates to a characteristic hot melt adhesive composition.

(A) A copolymer obtained by hydrogenating a styrene-isoprene-styrene block copolymer or a styrene-butadiene-styrene block copolymer (B) Tackifier (q Number average molecule [crystals of 20,000 or less) The true melt adhesive obtained from the composition containing polypropylene has excellent adhesion heat resistance and heat creep resistance against polyolefin resins, especially polypropylene, and even metals, and has excellent workability with melt coating equipment and heat resistance. It has excellent performance in terms of thermal stability during melting.

0(A) Copolymer obtained by hydrogenating styrene-isoprene-styrene block copolymer or styrene-butadiene-styrene block copolymer The copolymer used in the present invention is commonly called S E Fj S system. It is called a thermoplastic nidistomer, and there are products such as '1-1657J.

The copolymer used in the present invention is preferably a copolymer containing 35% by weight or less of styrene units.

The blending ratio of such a copolymer in the composition of the present invention is desirably 5 to 70% by weight in the composition, and if it is less than 5 to 70% by weight, the adhesion to polyolefin resins, especially polypropylene, and metals will be reduced. If the amount exceeds 70% by weight, the adhesive force may decrease and the fluidity during heating and melting may be impaired, so it is desirable to avoid this. More preferably 1
It is 0% by weight or more and 50% by weight or less, and depending on the proportion used, a composition with extremely strong adhesive properties can be obtained.

0 (■3) Tackifier Tackifiers include rosin-based ones such as natural rosin, polymerized rosin, and derivatives thereof such as EVA, pentaerythate ester rosin, RiIJ serine ester rosin, and hydrogenated resins thereof. Specifically, commercially available products include gum rosin, wood rosin, ester gum A, ester gum H, Bencel A, Bencel C (Arayo Kagaku Kogyo ■
), Pentaline A17 Oral AX, Foral 85
, Forgil 105. Examples include Pentaline C (referred to as Rika Percules). Terpene-based resins include polyterpene resins, terpene phenol resins, and their hydrogenated resins.Specifically, commercially available products include Picolite S, Picolite A (Pico Co., Ltd.), YS Resin, YS Polyster T, and Clearon ( There are cheap crude oil and fat■).

In addition, petroleum resins include aliphatic petroleum resins, aromatic petroleum resins, copolymer petroleum resins, and hydrogenated petroleum resins.Specifically, commercially available products include Escoresot (Toho Oil Resin■), Hilets (Mikata Petrochemical ■), Finton (Nippon Zeon ■), Wingtac (Gutsdoyer ■), Statanok (Reichhold ■), Toho Betrozin (Toho Oil Resin ■), Nisseki Neopolymer (Japan Petrochemical ■) , Vetrozin, Tac Ace (Mikata Petrochemical ■), Escolenots (Esso Chemical ■), Tobo...
Iresin (Toho Oil Resin ■), Super Star Tank (
Reichhold (■), Alcon P and M (Arayo Kagaku Kogyo ■), and Picovert (Bicone 1■). Furthermore, coumaron-indene resin, thermoplastic phenol resin, etc. can also be used. In the present invention, these tackifiers can be used depending on the purpose, but hydrogenated resins are preferred for the present invention. These tackifiers are used to increase adhesive properties to the adherend.

The proportion of such a tackifier in the composition of the present invention is desirably 1% or more and 70 mm or less, and more preferably 20 mm or more and 60 mm or less in terms of suboxide. If the ratio is less than 10% by weight, the adhesion to the adherend material, especially polypropylene or metal, will decrease, while if it exceeds 70% by weight, the cohesive force of the adhesive will decrease, and the adhesive strength, especially Adhesion heat resistance may also be reduced. A tackifier having a softening point of 60° C. or higher and 150° C. or lower is preferred for the present invention.

○(Cj Crystalline polypropylene with a number average molecular weight of 20,000 or less Crystalline polypropylene with a number average molecular weight of 20,000 or less is a powdered polypropylene obtained by polymerizing propylene or decomposing isotactic polypropylene, etc., and is commercially available. For example, Viscol 33o
P (a average molecular zisooo, R&B softening point 152°C)
, Viscole 550P (number average molecular weight 4000, ft&
B softening point 150℃), Viscoel 660P (number average molecule 1i3000, R&B softening point 145℃), Viscole T
S-200 (number average molecular weight 3500, R&B softening point 14
5℃) (all manufactured by Sanyo Chemical).

By using such polypropylene, it is possible to obtain a composition with little tack, which has excellent adhesion properties depending on the month of application, particularly excellent adhesion heat resistance, and excellent fluidity when melted by heating. In addition, its characteristics are molecule-
is 1. [If a crystalline polypropylene with a molecular weight of 100 to 5,000 is used, the effect will be even more noticeable, so it is preferable to use such a polypropylene in the present invention.

The blending ratio of such polypropylene in the composition of the present invention is desirably 10 to 75% by weight, more preferably 20 to 60% by weight. If the weight ratio is less than 10 wt. Adhesion and adhesive heat resistance become insufficient.

In the present invention, a part of the -F crystalline polypropylene,
Non-grade atactic polypropylene, which is mainly separated as a by-product of isotactic polypropylene, such as Vistalon (R&B softening point 125'C ~ 155℃ Chiba Fine Chemical ■) Vistak L (R&B softening softening point 5~60 1&B softening 140 to 160° C.).

In addition, the substitution rate is 7074 of crystalline polypropylene:
If it is more than 4, the properties of crystalline polypropylene will be lost, so it is necessary to avoid making it more than 70% by weight.

Note that it is also possible to use polypropylene copolymerized with other monomers as long as the crystallinity is not impaired as the crystalline polypropylene of the present invention.

0 Other additives The composition of the present invention has excellent compatibility during heating and melting due to the combination of the above-mentioned hydrogenated block copolymer, tackifier, and polypropylene. 1 e.g.
When using A, EEA, 'y7 BVA, ethylene-propylene comonomer, styrene-isoprene-styrene, or styrene-butadiene-styrene block copolymer, the compatibility during melting is insufficient and hot Although they are not suitable as melt adhesive compositions, it is of course possible to add them to the composition of the present invention within a range that does not impair its characteristics1.Also, waxes such as Paraffin wax, micro wax, low molecular weight 1 polyethylene, or low molecular weight liquid rubber such as polybutene, polyisoprene, polyisobutylene, polybutadiene, or extender oil such as paraffinic, naphthenic, or aromatic hydrocarbon-based petroleum high boiling fractions It is also possible to add liquid rosin, liquid terpene, or aggregates such as talc, silica, calcium carbonate, and lead oxide within a range that does not impair the characteristics of the present invention. Furthermore, for the composition of the present invention, an antioxidant is preferably added. < may be added within the range of 3% to the total composition.

The hot melt adhesive composition of the present invention can be obtained with such a composition, but if the coatability during melting is taken into consideration, the melt viscosity of the composition of the present invention should not exceed 100,000 cps/200°C. preferably L<, more preferably 1000
cps7200℃ or higher 21'1llOOcps/20
0℃ or less, and considering the required adhesive heat resistance, R
&B The softening point is preferably 1[]0°C or more and 160°C or less, more preferably 120°C or more and 160°C or less.

Such compositions are referred to as hot melt applicators.
Although it can be an excellent adhesive suitable for melt coating equipment, it goes without saying that the adhesive obtained from the composition of the present invention may be formed into a sheet or applied to an adherend in advance and then heat-bonded again. It is also possible.

O Adhesive manufacturing method The adhesive made from the composition of the present invention is placed in a bath melting tank called a heated bath melting stirring tank, preferably at a temperature of 150°C or more and 250°C or less under a nitrogen stream. A method of dissolving each component simultaneously or sequentially by rotating a stirring blade in a kneader, a method of mixing by applying shear under heating with a water-like rotating blade called a kneader, and a method of mixing by applying shear under heating using an extruder, that is, a single-screw or twin-screw 17
It can be produced by any method normally used in the production of hot melt adhesives, such as a method of melting and mixing under heating.

"Function" The hot melt adhesive composition containing three components of the present invention is suitable for use with polyolefin thread resins, especially polypropylene, which are difficult to bond due to the coexistence of the three components.
It has the effect of providing an adhesive with excellent heat resistance for adhesion to metal manuscripts.Moreover, the adhesive has excellent workability in melt coating equipment, has excellent heat stability during melting, and has little resin tack in the adhesive layer. It can be used extremely effectively even in applications where the adhesive is exposed, and this excellent effect of the present invention was achieved only by using the three components together.

"Examples and Comparative Examples" () Evaluation method R&B softening point: Measured according to JIS-2207.

Melt viscosity: 1 according to JAI-7-1980
The mixture was heated to 90° C. and measured using a B-type rotational viscosity needle.

Melt stability: Melt with a hot melt applicator Nordson M type (Nordon ■) at a measured temperature of 190° C. After 5 hours, the presence or absence of separation in the cypress was confirmed.

Rating: 0...no separation observed at all, X...
The test was carried out on the assumption that it was unusable due to separation.

At the same time, the presence or absence of adhesion due to heating was checked and evaluated as 0: No change from the initial stage, ×: Significant change from the initial stage.

Adhesive strength: The adhesive composition was put into the above applicator, and after 2 hours, it was applied to a 101 square polypropylene film (300μ) Kr) with a coating amount of 517H. Polypropylene film (
600μ) was adhered by hand pressure. The adhesive piece was cut to a width of 25 mm and the T-shaped peeling strength was measured. The measurement temperature is room temperature (23℃
) at 80°C.

Similarly, the tensile shear strength was determined by overlapping the adhesive part in a width of 10°C.
It was cut into wide pieces and its strength was measured.

Adhesive samples were prepared for all (aluminum sheets) (100μ) and the strength was measured. T type・
- The chestnut strength was measured at a tensile rate of 200 w/-, and the obtained strength was expressed in units of kyf/25 tm. The tensile shear strength was measured at a tensile rate of 10 strokes/-, and the obtained strength was expressed in units of f/10×25 m.

Creep temperature: According to JIS-6844 adhesive softening temperature measurement method, using an adhesive sample equivalent to that used for the tensile shear strength above, 10 laps x 25
A load of 200 g was applied per width of the bonded portion, and the sample was kept in a constant temperature chamber at 38° C. for 15 minutes, then the temperature was increased at a rate of 2° C. per 5 minutes, and the temperature at which the bonded portion broke was displayed.

Examples 1 to 6, Comparative Examples 1 to 5 Biscol 660 in a 107fi stirring cypress heated to 200°C
P (Sanyo Kasei ■) 1゜12kL Bistacks Chiba Fine Chemicals ■) 112kL Antioxidant Irg): Ni x
-1010 (polymer hindered polyhydric phenol; Teva Geigy ■) 40y was melted and stirred 7, and the dissolved layer and tackifier YS Polystacy-145 (terpene phenol resin; softening point 145°C; cheap crude oil ■) t12kl were gradually added. After the liquid temperature rose to 200° C., the copolymer Kraton G-1 (557α<Sk) was added and stirred for 2 hours. After confirming dissolution, the mixture was taken out from the tank to obtain an adhesive. The results of evaluation using the above evaluation method are shown in the table as Example 1.

Similarly, the tackifier of Example 1 was added to Finton G-
1oo (Cff-based petroleum resin, softening point 95°C; Nippon Seon ■), Alcon P-115 (hydrogenated petroleum resin, softening point 11
Examples 2 and 3 were obtained by changing the temperature at 5°C; Arayo Kagaku ■), Example 4 was obtained by changing the component ratio of Example 1, copolymer, YS Polystacy-145 as a tackifier, and crystals. Example 5 is an adhesive obtained from Viscol 660P as polypropylene, which is also shown in Table 1.

As a comparative example, compared to Example 1, a copolymer was not used, and a copolymer was replaced with Cauliflex TR-1107 (
Styrene blade soprek hatyrene copolymer; Shell Chemical ■),
1shi V-420 (EvA; Sankata Polychemical @) > A-
Comparative Examples 1 to 5I show an example in which y 04 (EEA; three-piece polychemical ■) was used, and an example in which only non-quality Bistack L was used as the polypropylene. The manufacturing method was the same as in Example 1. The component ratios are shown in the table.

The evaluation results of the polyamide hot melt adhesive DPX-850 (Henkel Hakusui ■) as Comparative Example 6 are shown in the table.

(c) Effects of the Invention The adhesive composition of the present invention has excellent adhesion and heat resistance to not only metals but also olefin resins, especially polypropylene resins, which were conventionally considered difficult to bond, and is also suitable for product assembly. The melt coating adhesive method using a hot melt applicator can provide hot melt adhesives with excellent melt stability, and is suitable for various industrial fields including adhesives and sealing adhesives for electrical parts, automobile parts, industrial filter parts, etc. It has an excellent effect that it can be used effectively.

Claims (1)

[Scope of Claims] 1. A hot melt adhesive composition characterized by containing the following three components. (A) Copolymer obtained by hydrogenating styrene-isoprene-styrene block copolymer or styrene-butadiene-styrene block copolymer (B) Tackifier (C) Crystallinity with number average molecular weight of 20,000 or less polypropylene