JPH0237955B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a hot melt adhesive composition,
More specifically, the present invention relates to a hot melt adhesive composition that exhibits stable foamability, adheres uneven surfaces, and exhibits an effective sealing function. Many techniques for foaming and utilizing resins have been known in the past. For example, techniques for using expanded polystyrene as a packaging material and foaming urethane for use as molded products are widely practiced. The use of these foams is based on the properties of the resin constituting the foam or the attributes resulting from the foaming method, and therefore, in many cases, the manner in which the foam is used depends on the type of resin used. It's almost fixed. Therefore, in the development of uses for foams, resins with properties suitable for the intended use are selected, and efforts are being made to foam them. In the invention disclosed in JP-A-54-15967, polyethylene, polypropylene, ethylene-
A surfactant is added to vinyl acetate copolymer, polyester, and polyamide to form foam in the molten state.
Efforts have been made to use it in hot melt adhesives. In this publication, the stability of the foam of molten resin is improved by using a hydrocarbon surfactant consisting of a lipophilic group and a hydrophilic group, but this alone is not necessarily sufficient to stabilize the foam, and inorganic fine powder A method has been adopted to extend the life of the foam by adding . However, since finely powdered inorganic substances have the disadvantage of inhibiting abrasion of hot melt foam coating equipment, the amount added is limited to a very small amount, and if possible, it is preferable not to use inorganic substances. As a result of various studies on surfactants that improve the stability (life span) of molten resin foam without using undesirable inorganic substances in hot melt foam coating equipment, the present inventor found that fluorine-based surfactants and/or We have completed the present invention by discovering that organosilicon surfactants are very effective. That is, the present invention is solid at room temperature and at 70 to 250°C.
A foamed hot melt adhesive comprising a thermoplastic resin selected from the group consisting of addition polymers and ester condensation polymers that melt and exhibit fluidity at a temperature of The present invention provides a pharmaceutical composition. The thermoplastic resin used in the present invention is a polymer produced by a known method, and is heated at a temperature of 70 to 250°C.
It melts and exhibits fluidity at a temperature of . Preferably, the melt viscosity measured by a B-type viscometer at a temperature of 70 to 250° C. is 500,000 cps or less, more preferably 100,000 cps or less. Monomers used in the production of such addition polymers include olefins such as ethylene and propylene, acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl. Acrylic monomers such as methacrylate, lauryl acrylate, 2-ethylhexyl acrylate, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide,
Styrene, O-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, α
-Alkenyl aromatic monomers such as vinylxylene, α-chlorostyrene, α-bromostyrene, vinyl monomers such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl acetate, vinylpyrrolidone, vinyl stearate, butadiene, isoprene, chloroprene, etc. Examples include diene monomers.
These monomers may be copolymerized with each other,
Further, if necessary, it may be copolymerized with crotonic acid, itaconic acid, maleic acid, methylmaleic acid, fumaric acid, vinylbenzoic acid, or the like. Preferred addition polymers include polyethylene, atactic polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl alcohol copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, and maleic acid. Modified ethylene-vinyl acetate copolymer, acrylic acid modified ethylene-vinyl acetate copolymer, polyisobutylene modified ethylene-vinyl acetate copolymer,
Ethylene-ethyl acrylate copolymer, ethylene-isobutyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid-
Acrylamide-acrylic ester copolymer,
Ethylene-propylene-acrylic acid copolymer, ethylene-propylene-styrene block copolymer, polyisobutylene, polyvinyl butyral,
Polyvinyl ether, poly-α-methylstyrene, polyvinyl alcohol, vinyl acetate-crotonic acid copolymer, vinyl acetate phthalic anhydride copolymer, vinyl acetate-vinyl pyrrolidone copolymer, polyacrylic ester, acrylic ester-acrylonitrile Copolymer, methacrylic acid ester-acrylic acid copolymer, vinylidene chloride-methacrylic acid ester copolymer, vinylidene chloride-acrylonitrile copolymer, polybutadiene, polyisoprene, polychloroprene, styrene-butadiene copolymer, styrene-isoprene -Styrene block copolymer, styrene-butadiene-styrene block copolymer, etc. Further, the dicarboxylic acid component used in the production of the ester type condensation polymer of the present invention is an aliphatic, alicyclic or aromatic one, such as oxalic acid, malonic acid, dimethylmalonic acid, succinic acid, glutaric acid, Adipic acid, trimethyladipic acid, pimelic acid, 2,2-dimethylglutaric acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid ,1,
3-Cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, phthalic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6
- Naphthalene dicarboxylic acid, biphenyl dicarboxylic acid, and their ester-forming derivatives are used. Examples of diol components include ethylene glycol, 1,2-propanediol, 1,
3-propanediol, 1,4-butanediol, 2,4-dimethyl-2-ethylhexane-
1,3-diol, neopentyl glycol, 2
-Ethyl-2-butyl-1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10
-Decanediol, 2,2,2-trimethyl-
1,6-hexanediol, 1,4-cyclohexanedimethanol, p-xylylene glycol,
Examples include diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Polyesters having various features can be obtained by appropriately combining the above-mentioned dicaribonic acid or its ester-forming derivative with a diol. In the present invention, the ester type condensation polymer preferably used is one or more components such as isophthalic acid, adipic acid, sebacic acid, etc. added to the terephthalic acid component, and ethylene glycol, diethylene glycol, 1,
It is a polyester that is polymerized by adding one or more diols such as 4-butanediol and neopentyl glycol. Additives such as tackifier resins, plasticizers, softeners, waxes, oils, antioxidants, and other fillers can also be added to the above thermoplastic resin (base polymer) as required. Tackifier resins are used to improve the wettability and workability of hot melt adhesives, and include rosin and rosin derivatives, terpene resins, terpene phenol resins,
Compatibility with the base polymer from aliphatic petroleum resins, aromatic petroleum resins, hydrogenated and copolymerized petroleum resins, dicyclopentadiene petroleum resins, coumaron-indene resins, styrene resins, isoprene resins, etc. , are selected and used in consideration of softening point, thermal stability, and adhesion. Plasticizers and softeners are added to improve wettability to adherends, low-temperature flexibility, impact resistance, etc., and dioctyl phthalate, dibutyl phthalate, polybutene, liquid polyisoprene, polyisobutylene, etc. are used. Wax and oil are added to reduce melt viscosity, prevent blocking, adjust open time, etc., and paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, and other modified waxes are used. As the antioxidant, hindered phenols, triazine derivatives, dialkylphenol sulfides, etc. are used. The types and proportions of these additives are appropriately selected depending on the intended use of the adhesive. The fluorine compound used in the present invention has surfactant ability. In the present invention, surface-active ability refers to the ability to lower the surface tension of the above-mentioned thermoplastic resin in a molten state. Since the fluorine compound according to the present invention must have surface-active ability, its chemical structure has a perfluoroalkyl group and a lipophilic group portion and/or a hydrophilic group portion. The fluorine compound may be one in which hydrogen in an organic group is replaced with fluorine by an electrolytic fluorination method, or an ethylenically unsaturated compound fluorinated by a telomerization method or an oligomerization method. It may be a low-polymerized compound. For example, generally known fluorinated surfactants and fluorinated oligomeric surfactants represented by the following general formula are often used in the present invention. (In the formula, R _f is C _o F _2o+1 , n is an integer of 6 to 18, R is H or an alkyl group having 1 to 5 carbon atoms, and X is (-
CH ₂ CH ₂ O) - _n H, - (CH ₂ ) - _l OPO ₃ M ₂ , -
CH ₂ CH ₂ OSO ₃ M, (-CH ₂ )- _l COOM or (-
CH ₂ )― _l ⁽⁺⁾ _N (R) ₃ L, m is an integer from 1 to 50, l is 1
an integer of ~5, M is hydrogen or a cation, and L is an anion. ) R _f SO ₃ M ……(2) (In the formula, R _f and M are the same as in formula (1)) R _f CO―Y …(3) (In the formula, R _f is the same as in formula (1), Y teeth

【formula】

【formula】

[Formula] or OM, R, l, M are the same as formula (1)) (In the formula, R' _f is C _o F _2o-1 , n is an integer from 6 to 18, and Z is

【formula】

[Formula]-X,- Y,

【formula】 【formula】

【formula】

[Formula] -OM, -NR ₃ ,

【formula】

【formula】

【formula】

or

[Formula], R, X, _m , l, M, L are the same as formula (1), Y is the same as _{formula ( 3} )) ...(5) (In the formula, R _f and m are the same as in formula (1), W is R, R _f ,

[Formula] or - ⁽⁺⁾ _N R ₃ L, m' is an integer from 1 to 50, R and L are formula (1)
) R _f ―CH ₂ CH ₂ ―Y ……(6) (In the formula, R _f is the same as in formula (1), and V is -O(-CH ₂ CH ₂ O(- _n SO ₃ M, -
SCH ₂ CH ₂ CONH ₂ CH ₂ CH ₂ SO ₃ M or -
SCH ₂ COOC ₂ H ₄ ⁽⁺⁾ _N (CH ₃ ) ₃ L, m, M, L
is the same as formula (1)) Among these, those having a nonionic or anionic hydrophilic group are preferred from the viewpoint of thermal stability. The organosilicon compound used in the present invention is a compound that necessarily has an Si-O-Si bond in the molecule,
In addition to this bond, those having an anionic, cationic, or nonionic hydrophilic group are preferred.
As anionic hydrophilic groups, sulfonic acid groups, sulfate groups, carboxylic acid groups, phosphoric acid groups, etc. are used as counter ions with alkali metal ions and ammonium ions, and as nonionic hydrophilic groups, hydroxyl groups, amino groups, polyester groups, etc. are used. An oxyalkyl group or an amine oxide group is used, and a group having quaternary nitrogen is used as the cationic hydrophilic group. When the molecular core is polysiloxane, a polysiloxane having a viscosity of 20,000 cps or less at 25° C. and into which various hydrophilic groups have been appropriately introduced may also be used. For example, commonly known dimethylpolysiloxane, alkylpolysiloxane such as methylhydrodienepolysiloxane, amino-modified polysiloxane,
Alcohol-modified polysiloxane, carboxyl-modified polysiloxane, fluorine-modified polysiloxane,
Polyether-modified polysiloxanes, polysiloxane sulfonates, polysiloxane carboxylates, polysiloxane aminosulfonates, and the like are used. In addition, when the core of the molecule is a carbon chain, it has Si-O-Si bonds in the molecule, a hydrophilic group is bonded to the chain, and nitrogen, oxygen, silicon, nitrogen, oxygen, silicon, etc. are added to the chain constituent elements as appropriate. A generally known material containing sulfur or the like is used. The amount of the fluorine compound or organosilicon compound added to the thermoplastic resin is 0.001 to 5 PHR (parts by weight/100 parts by weight of resin), preferably 0.005 to 1 PHR.
It is. If the amount added is less than 0.001 PHR, the foam stability during foaming will be poor, and if it is more than 5 PHR, it will adversely affect the physical properties of the resin, such as causing a decrease in resin strength. The fluorine compound or organosilicon compound according to the present invention is added and mixed by heating and melting the thermoplastic resin. Mixing is carried out using a generally known heated stirring tank, high-speed mixer, mixing roll, extruder, or the like. In this way, the composition according to the present invention can be produced. The composition after production may be used as it is, or may be cooled and stored, or cooled and pulverized and stored, and used as needed and in the required amount. The use of the composition according to the invention is most effectively carried out by introducing foam in the molten state and applying, pouring or molding in the foamed state. The gas constituting the bubbles may be nitrogen, carbon dioxide, or air. Other inert gases can also be used. The introduction of bubbles may be carried out by melting the composition according to the invention, blowing gas and, if necessary, applying pressure. or,
Alternatively, foam may be introduced by using a blowing agent and mixing it into the composition of the invention at a temperature below the blowing agent's gas release temperature, and at the time of use at a temperature above the blowing agent's gas release temperature. It is possible. In this case, commonly known blowing agents are used, such as nitroso blowing agents such as dinitrosopentamethylenetetramine, azo blowing agents such as diazocarboxylic acid amide, p,p'-oxybisbenzenesulfonylhydrazide, , 3-disulfonyl hydrazide, and aromatic hydrazide foaming agents such as diphenyl sulfon. The blowing agent is selected to have a decomposition temperature higher than the softening point of the thermoplastic resin mentioned above, and is
Used in a range of 0.5 to 15 parts by weight. The composition for foaming hot melt adhesives according to the present invention may be foamed using a device. A heating and pressurizing hot melt applicator disclosed in Publication No. 17645/1983 is preferred. Using this applicator, an inert gas such as nitrogen gas, carbon dioxide gas, or air can be dissolved or dispersed in the melt of the composition of the present invention under high pressure, and foamed by discharging it into normal pressure. If a foaming machine is not used, the foaming agent is melted and mixed with the composition of the present invention at a temperature below the decomposition temperature, formed into a thread, string, film, web, powder, etc., and placed on a substrate. It can also be used for hot melt applications by heating and foaming. The foamed hot melt adhesive composition of the present invention exhibits various useful functions because the foam after foaming is extremely stable, and depending on the type of thermoplastic resin, it forms a soft or hard foam. For example, it can be used as a sealant, by foaming the composition according to the invention,
When filled into a gap, it adheres and hardens within the gap, forming a foam structure consisting of closed cells and sealing the gap. When a hard resin such as terephthalic acid polyester is used as a sealant, it will not collapse even under considerable force, making it possible to use a lightweight, heat-insulating sealant with excellent sealing properties as a sealant for buildings. enable. When a soft resin such as a rubber-based polymer is used as a sealing material, it has excellent vibration and shock absorbing power, and can be used as a sealing material that can follow large deformations. Since the foam formed by foaming the foamed hot melt adhesive composition according to the present invention has high thixotropic properties, it does not sag when applied to a vertical surface. Therefore, even if the adherend had to be applied horizontally on its side, it can be applied while the adherend is in a vertical position, simplifying the work process. Further, by applying the composition for a foamed hot melt adhesive according to the present invention by pressure bonding after foaming, it is possible to fully exhibit its excellent function as a hot melt adhesive having extremely high adhesive ability. That is,
If the composition is foamed and applied to one adherend, the other adherend is overlapped, and the foam is pressed before it cools down, the composition will spread widely when the foam collapses, increasing the actual bonding area. . As a result, the adhesive strength is also greater than that of conventional non-foamed hot melt adhesives. On the other hand, if you want to keep the adhesive area constant, foamed hot melt adhesives spread more easily, so
The amount of adhesive used can be reduced, and
The adhesive layer can be made thinner. A thin adhesive layer is suitable for bonding parts that require dimensional accuracy and flexibility. Furthermore, the adhesion is strong due to the good filling properties for porous materials and uneven surfaces and the good permeability when pressed, making it suitable for substrates with complex surface morphology such as wood, building materials, leather, honeycomb structures, etc. Effective for bonding corrugated structures, etc. Another feature of the foamed hot melt adhesive composition of the present invention is that the foam's heat insulating effect allows for a longer open time and enables bonding over a wide area, which was previously thought to be impossible. Hereinafter, the present invention will be explained in further detail with reference to Examples. Example 1 40 parts by weight of ethylene-vinyl acetate copolymer (Evaflex #220 manufactured by Mitsui Polychemical Co., Ltd.), 60 parts by weight of hydrogenated rosin glycerin ester (Ester Gum H manufactured by Arakawa Chemical Co., Ltd.), antioxidant (Irganox 1010 manufactured by Ciba Geigy) 1 part by weight, perfluoroalkyl ethylene oxide adduct (Megafac F-142D manufactured by Dainippon Ink & Chemicals Co., Ltd.)
0.3 parts by weight was charged into a separable flask and stirred at 200° C. for 30 minutes in a nitrogen atmosphere to melt and mix.
After defoaming under reduced pressure of about 100 mmHg, the pressure was returned to normal, and the mixture was taken out into a flat bucket and cooled. The hot melt adhesive composition thus obtained had a softening point (ring and ball method) of 78°C, and a melt viscosity at 180°C measured by a B-type viscometer of 7000 cps. The composition was discharged and foamed using a hot melt adhesive applicator (Foam Melt Model FM-101, manufactured by Nordson Corp.) under the following conditions to examine the stability of the foam and to examine its adhesive properties. Temperature: 180°C Molten gas: Nitrogen (only for foaming type) Discharge pressure: 80 to 85 kg/cm ² The foam stability of the hot melt adhesive melt produced by foaming was measured by the following method. i.e. 180℃
A 100 ml graduated cylinder was fixed in an oil bath maintained at a constant temperature, and a fixed volume of hot melt adhesive was discharged into the cylinder under the above foaming conditions, and the bubbles were observed to disappear over time. The volumes immediately after discharge, after t minutes, and after the bubbles have completely disappeared are respectively V _i , V _t , and V _e ,
The volume of foam is expressed as a percentage as shown in the following equation. %Foam=V _t −V _e /V _i −V _e ×100 The time when the value of %Foam becomes 50 is defined as the half-life of the foam. The half life of the foam at 180°C for the hot melt adhesive composition of this example is
It took 135 minutes. Aluminum plates degreased with acetone were overlapped so that the area was 2.5 cm x 2.5 cm, and 0.15 g of the hot melt adhesive was foamed and applied to the center. Then, after a predetermined time (open time) had elapsed, another aluminum plate was placed on top of the other and immediately crimped for 10 seconds at a pressure of 10 kg/cm ² . In the same way, without introducing nitrogen gas, the hot melt adhesive was applied without foaming in the same manner as when applying conventional hot melt adhesives, and the aluminum plates were bonded together, and the difference in adhesive strength between foaming and non-foaming application was investigated. compared. 23℃, 20mm/min according to JIS K6850
Table 1 shows the results of measuring the shear adhesive strength at a tensile speed of
Shown below.

[Table] Looking at the adhesive surface after shear adhesive strength measurement, it was observed that the adhesive spread more with foam coating than with non-foaming coating. Comparing the adhesive strength at the same open time, the foam coating system is greater. Furthermore, if we look at the open time for the same adhesive strength, it is clear that the foam coating system has a longer open time. Comparative Examples 1 and 2 The same formulation as in Example 1, but containing no surfactant at all (Comparative Example 1), and 1.0 part by weight of polyoxyethylene octyl phenol ether and fine powder instead of the perfluoroalkyl ethylene oxide adduct. A foam containing 0.1 part by weight of silica (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) (Comparative Example 2) was foamed in the same manner as in Example 1, and the half-life of the foam was measured. The results are shown in Table 2.

[Table] Compared to the half-life of the foam of Comparative Examples 1 and 2, the half-life of the foam of the composition using the fluorine-containing surfactant of Example 1 is much longer, and the stability of the foam is significantly longer. I can see that it is improving. Example 2 Atactic polypropylene (Sun Attack manufactured by Chiba Fine Chemical Co., Ltd.) 90 parts by weight, polyisobutylene (Vistanetx LM manufactured by Exxon Chemical Co., Ltd.)
MS) 10 parts by weight, Tinuvin P 0.5 parts by weight as a stabilizer, Irganox 1010 1 part by weight (all manufactured by Ciba Geigy), dimethylpolysiloxane-polyethylene oxide copolymer (Toshiba Silicone)
Co., Ltd., silicone XFA4200) 0.3 parts by weight from 60 to 60
A foamed hot melt adhesive composition was obtained by roll kneading at a temperature of 120°C. The softening point of the composition is 115°C,
The melt viscosity at 160°C was 5100 cps. In the same manner as in Example 1, nitrogen gas was introduced into the composition at 160° C., and foaming was performed at a pressure of 65 kg/cm ² to examine the stability of the foam. The bubble's half-life was 118 minutes. Next, the ethanol-degreased ABS resin plates were bonded to each other in the same manner as in Example 1 by foam coating and non-foam coating so that the coating amount was the same, and the shear adhesive strength was measured. The results are shown in Table 3.

[Table] It can be seen that, as in Example 1, the adhesive strength is greater and the open time is longer when the foam coating is applied. Example 3 Dimethyl terephthalate, dimethyl isophthalate, dimethyl adipate, and 1,4-butadiol were charged in a separable flask at molar ratios of 55, 25, 20, and 150, and 400 ppm of titanium isopropinate was added as a catalyst and nitrogen was added. Atmosphere 150~
Transesterification reaction was carried out at 220°C for 1 hour and then at 220°C for 2 hours, and methanol was distilled off. moreover
The temperature was raised from 220°C to 240°C over 1 hour, and at the same time the pressure was gradually reduced to 0.1 mmHg. Polycondensation reaction was then carried out at 240°C and 0.1 mmHg for 2 hours to obtain polyester. 100 parts by weight of this polyester, 1 part by weight of antioxidant (Irganox 1010 manufactured by Ciba Geigy),
0.5 parts by weight of an organosilicon surfactant (Silicone F-230 manufactured by Shin-Etsu Chemical Co., Ltd.) was charged into a separable flask, and the mixture was melt-mixed by stirring at 220° C. for 30 minutes in a nitrogen atmosphere. Then, defoaming was performed in the same manner as in Example 1 to obtain a foamed hot melt adhesive composition.
The softening point of the composition is 155℃, and the melt viscosity at 215℃ is
It was 16000cps. The composition was discharged and foamed in the same manner as in Example 1 by introducing nitrogen gas and under the conditions of 215° C. and 70 kg/cm ² .
The half life of the foam measured at 215° C. in the same manner as in Example 1 was 316 minutes. Next, the composition was filled into a 60 c.c. aluminum cup while foaming, and a test piece was immediately inserted into the cup to cool and solidify. After leaving it at 23℃ for 2 days,
The test piece was pulled out from the aluminum cup at a pulling speed of 20 mm/min. Table 4 shows the pull-out strength for various test pieces.

[Table] The polyester foam layer was found in all the broken lump locations. Since the strength of polyester resin is high, the pull-out strength is also high. The foaming ratio is approximately 3 times. Therefore, compared to the case of filling and sealing with a conventional non-foaming hot melt adhesive, the amount of adhesive used can be reduced to about 1/3, which is economically advantageous. Since polyester has a high softening point, it is suitable for use as a filler or sealant in areas that require heat resistance of about 80 to 120°C. Example 4 35 parts by weight of styrene-butadiene-styrene block copolymer (Sorprene T-414 manufactured by Asahi Kasei Corporation), terpene resin (Picolite manufactured by Etsuo Chemical Co., Ltd.)
A115) 28 parts by weight, 35 parts by weight of paraffin wax (Paraffin 135 manufactured by Nippon Oil Co., Ltd.), 2 parts by weight of antioxidant (Nokrac TNP manufactured by Ouchi Shinko Chemical Co., Ltd.),
A hot melt adhesive composition having rubber elasticity was obtained by kneading 0.5 parts by weight of perfluoroalkyl phosphate ester (Megafac F-191 manufactured by Dainippon Ink and Chemicals Co., Ltd.) in a Banbury mixer at 100 to 180°C. This composition had a softening point of 117°C and a melt viscosity of 11,000 cps at 180°C. The hot melt adhesive was treated in the same manner as in Example 1 at 180°C and 75 kg/cm ²
The half-life of the foam measured by discharging the foam is
It took 215 minutes. Next, the mixture was filled into an aluminum cup in the same manner as in Example 3, and a test piece was immediately inserted therein to cool and solidify. The pull-out strengths of various test beads were measured under the same conditions as in Example 3, and the results shown in Table 5 were obtained. Note that the foaming ratio was 4.5 times.

[Table] Failure occurred in the hot melt adhesive foam layer, but the rubbery foam layer showed extremely large elongation before failure. Therefore, it is promising as a sealing material for parts that are subject to large deformations. Example 5 40 parts by weight of ethylene-ethyl acrylate copolymer (DPDA2304 manufactured by Union Carbide Co., Ltd.), aliphatic petroleum resin (Quinton A manufactured by Nippon Zeon Co., Ltd.)
100) 40 parts by weight, microcrystalline wax with a melting point of 90°C (micro wax manufactured by Mobil Oil Co., Ltd.)
190Y) 20 parts by weight, antioxidant (Irganox 1010 manufactured by Ciba Geigy) 1 part by weight, fluorine-based surfactant (Megafux F- manufactured by Dainippon Ink Industries, Ltd.)
177) 0.1 part by weight was charged into a separable flask and melted and mixed in the same manner as in Example 1. The softening point of the composition is 87℃, and the melt viscosity at 180℃ is 19000cps.
It was hot. At 180°C in the same manner as in Example 1.
The half life of the foam discharged at a discharge pressure of 80 kg/cm ² was 151 minutes. Next, the thickness under the same conditions
The composition was foamed and applied in a linear manner on 100μ aluminum foil at a rate of 4 g/m, and then left for a predetermined time (open time).
After this time, another piece of aluminum foil was placed on top of the other and immediately crimped. Aluminum foils were bonded together in the same manner using a non-foaming system in which nitrogen gas was not introduced. Table 6 shows the peel strength when T-peel was performed in the application direction of the hot melt adhesive at 23° C. and a tensile speed of 50 mm/min according to JIS K6854.

[Table] When the open time is 1 second, there is no difference between the foamed coating system and the non-foamed coating system, but as the open time becomes longer, the T-peel strength of the foamed coating system becomes greater. The spread width of the adhesive after peeling is larger in the foam coating system, and this is thought to be the reason why the strength is greater than that in the non-foaming system.

Claims (1)

[Claims] 1. Polyethylene, modified polyethylene, atactic polypropylene, styrene-isoprene-styrene block copolymer, styrene-butadiene-styrene block copolymer, and terephthalene, which are solid at room temperature and melt and flow at temperatures of 70 to 250°C. A thermoplastic resin selected from the group consisting of a thermoplastic copolyester consisting of acid/isophthalic acid/C ₆ - C ₂₀ aliphatic dicarboxylic acid / C ₂ - C ₁₀ aliphatic diol and a perfluoroalkyl group in the molecule. Foaming consisting of a fluorine-based surfactant having an oil base and/or a hydrophilic group and/or a silicon-based surfactant having a polysiloxane bond and an anionic, cationic, or nonionic hydrophilic group in the molecule. Composition for hot melt adhesives.