JPH058955B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Purpose of the invention [Field of industrial application] The present invention has excellent adhesion to difficult-to-adhesive polyolefin plastics such as polypropylene, polyethylene, and ethylene-propylene copolymers, which are widely used in various industrial fields. The present invention also relates to a hot melt adhesive that has excellent thermal stability during heating and melting, and can be used in a wide variety of industrial fields. [Prior Art] Conventionally, polyolefin plastics such as polypropylene and polyethylene have been known to be difficult to adhere to due to their non-polar and crystalline surfaces, and various methods of bonding these materials have been studied. . These methods include (1) a method of thermally adhering the same materials to each other using heat sealing, ultrasonic bonding, etc.; (2) A method of increasing adhesive strength by treating the surface of the material. For example, oxidizing the surface with acid solution treatment, electric discharge, ultraviolet irradiation, or radiation irradiation to introduce polar groups, or exposing it to chlorine-based solvents for a short time. Immersion to roughen the surface and increase adhesive flow;
There are methods such as primer coating the surface with chlorinated polypropylene, silane coupling agents, etc., but method (1) is not only suitable only for bonding similar materials, but also has the disadvantage of damaging the material itself due to thermal deformation. In method (2), the number of adhesion steps increases, and no method has been found that has satisfactory adhesion performance itself. Furthermore, a method of bonding such difficult-to-bond materials using pressure-sensitive adhesives, that is, tackiness, is being considered, but when using pressure-sensitive adhesive sheets, the number of steps in the bonding process increases, and it is not suitable for bonding molded objects. However, the processing cost of adhesive sheets has become a problem. Apart from these, pressure-sensitive adhesives using styrene-isoprene-styrene block copolymers are available in Japanese Patent Publication No. 17037-17037, Special Publication No. 21720 No. 47-2010, No. 9932 No. 48-9932.
et al., it has been proposed that a specific adhesive resin be added to a styrene-butadiene-styrene block copolymer or a styrene-isoprene-styrene block copolymer, or that the adhesive resin and a process oil called an extender oil, that is, a paraffin-based Pressure-sensitive adhesives containing high-boiling petroleum fractions such as hydrocarbons, naphthenic hydrocarbons, and aromatic hydrocarbons, liquid rosin, and liquid terpene have been proposed, but these have poor adhesion to difficult-to-adhere materials. is insufficient,
Even if adhesive properties are obtained, when melt-applying the adhesive as a hot-melt adhesive, a decrease in melt viscosity in a heated melting tank and an accompanying decrease in adhesive strength may occur due to the block copolymer or extender oil. There is a problem with volatilized vapor during melting, which is thought to be caused by oil and filler oil, that is, there is a problem with thermal stability during heating and melting. [Problems to be Solved by the Invention] The present invention has excellent adhesion performance to the above-mentioned polyolefin base material, which is said to be extremely difficult to adhere to, and also has excellent adhesive properties when used as a hot melt adhesive. The purpose is to provide a hot melt adhesive composition that has excellent workability in equipment and heat stability during melting, and is free from performance changes due to vapor volatilization during heating and no contamination of the adhesive material, and has tackiness at room temperature. The aim is to provide a composition that can be applied to everything from adhesives to non-stick adhesives. (B) Structure of the Invention [Means for Solving the Problems] The present inventors have continued to conduct intensive studies on compositions that provide excellent hot melt adhesives that do not have the above-mentioned problems, and have found that compositions containing four specific components are The inventors have discovered that these requirements can be satisfied and have completed the present invention. That is, the present invention contains the following four components, and the ratio of both components based on the total amount of components (A) and (B) is:
This invention relates to a hot melt adhesive composition characterized in that component (A) is 30 to 90% by weight and component (B) is 70 to 10% by weight. (A) Styrene-isoprene-styrene block copolymer (B) Copolymer obtained by hydrogenating styrene-isoprene-styrene block copolymer or styrene-butadiene-styrene block copolymer (C) Adhesive resin (D) Wax or hydrocarbon synthetic rubber having a number average molecular weight of 300 or more and a pour point of 120°C or less. Hot melt adhesives obtained from such compositions have excellent adhesion to polyolefin plastics and are thermally stable when melted by heating. It has excellent performance in terms of properties. Γ (A) Styrene-isoprene-styrene block copolymer Styrene as component (A) used in the present invention
Isoprene-styrene block copolymer is commonly known as
It is called an SIS thermoplastic elastomer, and for example, commercial products such as "Califlex TR-1107" and "Califlex TR-1107" manufactured by Ciel Chemical Co., Ltd.
TR-1111,” “Califlex TR-1112,” and “Califlex TR-1117.” Γ (B) Copolymer obtained by hydrogenating styrene-isoprene-styrene block copolymer or styrene-butadiene-styrene block copolymer (B) Styrene-isoprene-styrene or styrene-butadiene-styrene as component The copolymer obtained by hydrogenating a block copolymer is commonly called
SEBS i.e. styrene-ethylene-butylene-
It is said to be a styrene copolymer, etc., and for example, as a commercially available product, "Krayton G-
1650” “Clayton G-1651” “Clayton G-
1652" and "Clayton G-1657." In the present invention, a copolymer containing components (A) and (B) containing 35% by weight or less of styrene units is desirable. The ratio of the above-mentioned (A) component and (B) component in the present invention, that is, the ratio of both components based on the total amount of the (A) component and (B) component, is 30 to 90% by weight of the (A) component, (B) Ingredient 70~
It is 10% by weight. If the ratio of component (A) exceeds 90% by weight, the thermal stability of the composition during heating and melting will decrease. If the content is less than 30%, the adhesive strength to polyolefin materials, especially polypropylene materials, will decrease. More preferably, the weight ratio of each is in the range of 80:20 to 50:50. Γ (C) Adhesive resin Examples of adhesive resins include rosin-based natural rosin, polymerized rosin, and derivatives thereof, such as:
There are pentaerythrite ester rosin, glycerin ester rosin, and their hydrogenated resins, and specifically, commercially available products include gum rosin, udzurosin, ester gum A, ester gum H,
Hensel A, Pensel C (Arakawa Chemical Industry Co., Ltd.),
Pentaline A, Fuoral AX, Fuoral 85,
Examples include Fuoral 105 and Pentaline C (all manufactured by Rika Hercules Co., Ltd.). In addition, terpene-based resins include polyterpene resins, terpene phenol resins, and hydrogenated resins thereof.Specifically, commercially available products include Picolite S, Picolite A (Pico Co., Ltd.),
These include YS Resin (cheap crude oil), YS Polyster T (cheap crude oil), and Clearon (cheap crude oil). In addition, petroleum resins include aliphatic petroleum resins,
There are aromatic petroleum resins, copolymer petroleum resins, hydrogenated petroleum resins, etc. Commercially available products include Escorets (Tonen Petrochemicals Co., Ltd.), Hiretsus (Mitsui Petrochemicals Co., Ltd.), and Quinton (Mitsui Petrochemicals Co., Ltd.). Nippon Zeon Co., Ltd.), Wingtac (GutsDoyer Co., Ltd.), Statac (Reichhold Co., Ltd.), Toho Petrosin (Tonen Petroleum Resins Co., Ltd.), Nisseki Neopolymer (Nippon Petrochemical Co., Ltd.)
), Petrozin (Mitsui Petrochemical Co., Ltd.), Tatsuku Ace (Mitsui Petrochemical Co., Ltd.), Escorets (Etsuo Chemical Co., Ltd.), Toho Hi Resin (Toho Petroleum Resin Co., Ltd.),
Examples include Super Star Tactic (Reichhold Co., Ltd.), Alcon P and M (Arakawa Chemical Industries Co., Ltd.), and Pico Pale (Pico Co., Ltd.). In the present invention, these adhesive resins can be used depending on the purpose, but hydrogenated resins are preferred for the present invention. These adhesive resins are used to increase the adhesion properties to the adherend material, and the blending amount is (A)
For 100 parts by weight of the total amount of copolymer of component and (B) component,
The range is preferably 30 parts by weight or more and 300 parts by weight or less, more preferably 50 parts by weight or more and 150 parts by weight or less, and when the amount is less than 30 parts, the adhesive according to the present invention has a negative effect on the polyolefin material. It becomes difficult to obtain sufficient adhesive force, and on the contrary,
If the amount exceeds 30%, the cohesive force of the adhesive decreases, and the adhesive force decreases. Also, its softening point is 60℃ or higher,
Adhesive resins having a temperature of 150°C or less are preferred for the present invention. Γ (D) Wax or hydrocarbon synthetic rubber with a number average molecular weight of 300 or less and a pour point of 120°C or less. The waxes used in the present invention include paraffin wax, micro wax, low molecular weight polyethylene, and low molecular weight polypropylene. These are used to increase the fluidity and non-stickiness of the adhesive composition when it is melted. Parafine wax is generally a solid hydrocarbon separated from the high-boiling fraction of crude oil, and is commercially available from Nippon Oil Co., Ltd., Nippon Seiro Co., Ltd., and the like. Microwaxes are generally high-melting waxes refined from high-boiling fractions of crude oil, and commercially available products include Nisseki Microwaxes (Nippon Oil Co., Ltd.) and Heimitsuku (Nippon Seiro Co., Ltd.). .
Low molecular weight polyethylene is generally obtained by polymerizing ethylene alone or by copolymerizing other α-olefins, and usually has a softening point of 80°C or higher and 140°C or lower.For example, AC polyethylene (allied chemical)
), Hoechst Wax PE (Hoechst Co., Ltd.), Mitsui Hiwax (Mitsui Petrochemical Co., Ltd.), Neowax (Yasu Oil Co., Ltd.), Sunwax (Sanyo Chemical Industries, Ltd.)
and so on. Low molecular weight polypropylene is generally obtained from a low polymerization degree of propylene or by oxidative decomposition of polypropylene, such as Viscole (Sanyo Chemical Industries, Ltd.), Hoechst Wax PP (Hoechst Co., Ltd.),
These include Vistac L Co., Ltd.) and Tac833 (Sumitomo Chemical Co., Ltd.). The hydrocarbon synthetic rubbers used in the present invention having a number average molecular weight of 300 or more and a pour point of 120°C or less include polybutene, polyisobutylene, polyisoprene, polybutadiene, and hydrogenated products thereof. It is preferable to have no functional groups other than unsaturated groups in the molecule, and further preferable are polybutene, 1,4-polyisoprene, polyisobutylene, and 1,4-polybutadiene, which have no unsaturated bonds in the side chain. Furthermore, polybutene, polyisobutylene, and hydrogenated synthetic rubber, which have no unsaturated groups other than at least the terminal end, are preferred. Specific examples include Kuraprene LIR, hydrogenated LIR (Clare Isoprene Chemical), Idemitsu Polybutene (Idemitsu Petrochemical), Nisseki Polybutene (Nippon Petrochemical), and Tetrax (Nippon Petrochemical). Such synthetic rubber not only significantly improves adhesion and cold resistance to polyolefin materials, but also provides a composition with excellent fluidity when melted. However, if the number average molecular weight of the synthetic rubber is less than 300, volatilized vapor during heating and melting may occur. If the pour point exceeds 120°C, the compatibility of the adhesive composition will be insufficient, and the cold resistance of the adhesive will be significantly impaired. The blending ratio of wax and synthetic rubber can be freely selected depending on the application without sacrificing the characteristics of the present invention, such as adhesion to polyolefin materials and thermal stability during heat melting. The non-adhesiveness of
It improves heat resistance, especially creep strength, and conversely, increasing the amount of synthetic rubber improves the cold resistance of the adhesive and increases tackiness, making it possible to use it as a heat-sensitive and pressure-sensitive adhesive. is a copolymer
The amount is preferably 10 parts by weight or more and 300 parts by weight or less per 100 parts by weight; if it is less than 10 parts by weight, the fluidity during melting will be insufficient and there is a risk that adhesive coating properties will be impaired. On the other hand, if it exceeds 300 parts by weight, the adhesion to the polyolefin material itself will be impaired. More preferably for the present invention,
50 to 200 parts by weight. It is also preferable to use both in combination because the characteristics of both can be exhibited. Γ Other additives As mentioned above, A-B-A used in the present invention
A composition containing high-boiling petroleum distillates such as paraffinic, naphthenic, and aromatic hydrocarbons, liquid rosin, liquid terpene, etc., called bulking oil or process oil, for the purpose of imparting tackiness to the block copolymer. Although it has already been reported that these bulking oils reduce the cohesive force of the composition, significantly impair adhesive heat resistance, especially creep resistance, and impair the heat stability during melting, which is a feature of the composition of the present invention. damage,
Furthermore, since the problem of contamination of the adhesive material by volatilized vapor during melting occurs, it is not suitable for achieving the purpose of the present invention, but it is possible to use them in the present invention to the extent that the characteristics of the present invention are not impaired. It is. In addition, other thermoplastic resins such as EVA, EEA, saponified EVA, ethylene-propylene copolymer, etc., and aggregates such as talc, silica, calcium carbonate, zinc white, etc., may be added to the composition of the present invention to achieve the characteristics of the present invention. It is also possible to add within a range that causes no damage. Furthermore, an antioxidant may be added to the composition of the present invention, preferably within a range of 3% based on the total composition. With such a composition, the hot melt adhesive composition of the present invention can be obtained, but considering the coatability when melted, the melt viscosity of the composition of the present invention is 100,000 cps/200°C.
The R&B softening point is preferably 60°C or more and 150°C or less. Γ Adhesive manufacturing method The adhesive made from the composition of the present invention is prepared by rotating a stirring blade in a melting tank called a heated melt stirring tank, preferably at a temperature of 150°C or more and 250°C or more, preferably in a nitrogen stream. A method in which hot melt adhesives are melted simultaneously or sequentially, a method in which they are mixed by heating and shearing using twin rotating blades called a kneader, and a method in which melting and mixing under heating in an extruder, that is, a single or twin screw. Manufacture is possible by any method used in manufacturing. [Function] The hot melt adhesive composition containing the four components of the present invention has the effect of providing an adhesive with excellent adhesion performance to polyolefin resins, which are difficult to adhere to, due to the coexistence of the four components. Moreover, the adhesive has excellent workability in melt coating equipment and heat stability during melting.
It is excellent in that there is no change in performance due to vapor volatilization during heating and there is no contamination of the adhesive material, and this excellent effect of the present invention was achieved for the first time by using four components in combination. [Examples and Comparative Examples] Γ Evaluation method R&B softening point...Measured according to JIS-K-2207. Melt viscosity: Measured using a B-type rotational viscometer after heating to 190°C according to JAI-7-1980. Melt stability: Melt with a hot melt applicator Nordson Model XI (Nordson Corporation) at a bath temperature of 190°C, and after 10 hours, measure the viscosity of the adhesive discharged from the gun using the method described above, and determine the viscosity decrease. I looked into it. Vapor volatilization: The fuming of the resin discharged in the above method was visually observed. Adhesive strength: 10cm square polypropylene film (300μ) after 2 hours of pouring the melted adhesive into the hot melt applicator.
It was applied in the form of a string at a coating weight of 5 g/m, and after 10 seconds, another polypropylene film (300μ) was adhered by hand pressure bonding. The adhesive piece was cut to a width of 25 m/m and the T-peel strength was measured. Measurement temperature is room temperature (below 23℃), below 0℃,
It was carried out at 50°C. The tensile speed was measured at 200 m/m/min. In the same manner, the adhesive performance after 10 hours was also measured. Examples 1 to 8, Comparative Examples 1 to 3 Microwax #155 (softening point 155: Nippon Petrochemical Co., Ltd.) was placed in a melting stirring tank heated to 200°C.
1Kg, 30g of Irganox-1010 (polymer hindered polyhydric phenol: Ciba Geigy) as an antioxidant
After melting, add the tackifier Alcon P
-115 (Hydrogenated petroleum resin: Softening point 115℃: Arakawa Chemical)
1Kg was gradually added, and after the liquid temperature rose to 200℃, the viscosity of the 25% by weight toluene solution of the copolymer at 25℃
Kraton G-1657, manufactured by Ciel Chemical Co., Ltd., whose viscosity at 25°C of a 20% by weight toluene solution containing 900 g of Cauliflex TR-1107 (styrene-isoprene-styrene block copolymer) manufactured by Ciel Chemical Co., Ltd., which has a viscosity of 1600 cps, is 1100 cps. (Styrene-ethylene-butylene-styrene block copolymer)
100 g was added, stirred for 2 hours, and after confirming dissolution, the adhesive was extracted from the tank. The results of the above evaluation are shown in the table as Example 1. Similarly, Example 1
Examples 2 to 4 were prepared using base resins in which the weight ratios of TR-1107 and G-1657 were 70 parts/30 parts, 50 parts/50 parts, and 30 parts/70 parts. Also, for the same weight ratio of TR-1107 and G-1657 as in Example 3 of 50 parts/50 parts, Quinton C-100 (aliphatic petroleum resin softening point 95°C Nippon Zeon) and polybutene 2000H (Nippon Zeon) were added as tackifiers. (see below), Ester Gum H (hydrogenated rosin glycerin ester softening point
Polybutene 2000H (pour point 20℃: molecular weight 2400: Example 8 used a hydrogenated polybutene system (Idemitsu Petrochemical). As a comparative example, TR-1107 and G were used as copolymers.
-1657 was used alone in Comparative Examples 1 and 2, and as an extender oil in place of wax and liquid synthetic rubber.
Cielflex 371J (expanded oil naphthenic oil:
Comparative Example 3 is shown in the table using Comparative Example 3. The manufacturing method was the same as in [Example 1]. The adhesives obtained in Examples 1 to 7 and Comparative Examples 1 to 2 belong to hot melt adhesives that do not have tackiness at room temperature.
The adhesive obtained in 1 was a pressure-sensitive hot melt adhesive. Example 9 Tetrax 6T (with a viscosity average molecular weight of
The following composition was prepared using polyisobutylene with a pour point of 112.5°C and its physical properties were measured. (Parts by weight) Cauliflex TR-1107 50 Kraton G-1657 50 Alcon p-115 100 Microwax 155 100 Tetrax 6T 50 Irganox 1010 3 The evaluation results are as follows, and it has excellent physical properties as a hot melt adhesive. I know that there is. R&B softening point 105℃ 190℃ Melt viscosity 8700cps T-peel strength when applied to polypropylene sheet After melting applicator for 2 hours (Kg/25mm) At 23℃ 9.8 At 0℃ 5.6 At 50℃ 4.3 After melting applicator for 8 hours (Kg/25mm ) At 23℃ 10.0 At 0℃ 5.7 At 50℃ 3.9

【table】

[Table] (C) Effects of the Invention The adhesive composition of the present invention has excellent adhesion to olefin plastic materials, which has been difficult to achieve with conventional hot melt adhesives, and is also capable of melt application adhesion using a hot melt applicator called product assembly. It is possible to provide a hot melt adhesive having excellent heating and melting stability, which has the excellent effect of being effectively used in various industrial fields including packaging and assembly.

Claims (1)

[Scope of Claims] 1 Contains the following four components, the ratio of both components (A) and (B) based on the total amount is 30 to 90% by weight, and the (B) component Hot melt adhesive composition characterized in that it is 70-10% by weight. (A) Styrene-isoprene-styrene block copolymer (B) Copolymer obtained by hydrogenating styrene-isoprene-styrene block copolymer or styrene-butadiene-styrene block copolymer (C) Adhesive resin (D) Wax or hydrocarbon synthetic rubber with a number average molecular weight of 300 or more and a pour point of 120°C or less.