JPH0334786B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aqueous emulsion type adhesive composition. In particular, it relates to an aqueous emulsion type adhesive composition that exhibits good adhesion to polyolefins. Furthermore, the present invention provides an adhesive composition that exhibits useful performance as a water-based contact adhesive. The most useful contact adhesive has traditionally been chloroprene rubber dissolved in an organic solvent, which has excellent physical properties such as adhesive strength, heat resistance, and water resistance, and is used in woodworking, footwear, automobile rubber, vehicles, etc.
It is used in large quantities in various fields such as electrical equipment and household use. However, this solvent-based contact adhesive has major problems. Since it contains a large amount of a highly flammable volatile solvent, there are problems such as contamination of the working environment due to solvent volatilization, adverse effects on the human body of workers due to inhalation of the solvent, and the risk of fire during work. Water-based contact adhesives have recently been developed as a way to solve the problems of solvent-based contact adhesives. However, while water-based contact adhesives have alleviated environmental health hazards and fire hazards, they lack the characteristics of solvent-based contact adhesives, such as initial adhesion, adhesive strength, heat resistance, and water resistance. It is still insufficient and we have not yet reached the point where we can switch to solvent-based contact adhesives. on the other hand,
2. Description of the Related Art Polyolefins, which are inexpensive and have good moldability and printability, and have low polarity are widely used in the market in the form of containers, sheets, films, foams, and the like. However, these polyolefins inherently have poor adhesive properties, and various surface treatment methods have been proposed to improve this. For example, the surface is oxidized by corona discharge, chromic acid treatment, ozone oxidation, ultraviolet irradiation, etc.
A method of creating carbonyl and carboxyl groups on the surface and chemically activating the surface to increase adhesion. A method of making the surface uneven using methods such as sandblasting to increase the surface area and improve adhesion. For example, a method in which polypropylene is treated at high temperature using a solvent such as toluene or trichlorethylene to elute amorphous and low molecular weight parts, making the surface uneven and improving adhesiveness. By irradiating the surface with radiation, acrylic acid,
Examples include grafting butadiene or the like to modify the surface and improve adhesion. However, even with such surface-treated materials, there is no commercially available adhesive that can firmly bond them. The current method of bonding polyethylene and polypropylene is to melt the surface with heat and weld it.
This method uses a pressure-sensitive adhesive with strong adhesive force to attach the adhesive. Although the former is an effective method in terms of adhesive strength, it is unsuitable for materials that cannot be heated, and the latter has a low level of adhesive strength. This is why there is a strong demand for adhesives that can firmly bond polyolefins at around room temperature. As a result of intensive studies by the present inventors regarding the above-mentioned problems, namely, the removal of solvent from solvent-based chloroprene rubber adhesives and the improvement of adhesiveness of polyolefin materials,
It has been found that an aqueous emulsion type adhesive composition comprising a combination of a specific acrylic copolymer and a specific rosin ester is particularly suitable for adhering polyolefins. Furthermore, we have also found that adding an aziridine compound to the aqueous emulsion type adhesive composition is effective in imparting heat resistance to the composition. That is, the present invention consists of an aqueous medium and a resin, the resin component being 50 to 95% by weight of an acrylic copolymer shown in [] below and 50 to 5% by weight of a disproportionated rosin ester shown in [] below. This is an aqueous emulsion type adhesive composition for polyolefin. [] Copolymerized with an alkyl acrylate having an alkyl group having 4 to 8 carbon atoms and an ethylenically unsaturated monomer containing a carboxyl group, or these and other vinyl monomers copolymerizable with these, resulting in glass transition Acrylic copolymer with a temperature range of -30 to -60℃. [] Disproportionated rosin ester with a softening point in the range of 70 to 130°C. Next, the composition of the present invention will be specifically described. [] Alkyl acrylate having an alkyl group having 4 to 8 carbon atoms includes, for example, n-butyl acrylate, isobutyl acrylate, hexyl acrylate, n-octyl acrylate, 2-
Ethylhexyl acrylate, etc., and these are essential components to keep the glass transition point (hereinafter referred to as "Tg point") of the polymer in the range of -30 to -60℃, and even if a single component contains two or more types. May be combined. Carboxyl group-containing ethylenically unsaturated monomers are essential components for improving adhesive strength to various materials, such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, monomethyl itaconate, monobutyl maleate, etc. This includes monoalkyl esters of unsaturated polyhydric carboxylic acids. The content of the carboxyl group-containing ethylenically unsaturated monomer is preferably 1 to 10% by weight in the monomer mixture for producing the acrylic copolymer of the present invention. If it is less than 1% by weight, the effect of improving adhesive strength is weak;
If it exceeds 10% by weight, the water resistance of the adhesive composition tends to decrease. The Tg point of the acrylic copolymer, which is one component of the present invention, is in the range of -30 to -60°C, and -35
A range of -55°C is preferred. When the Tg point exceeds -30°C, the resin is slightly hard, and when the disproportionated rosin ester [] is used in combination with this, the adhesive becomes even harder, resulting in lower peel bond strength and poor room-temperature adhesion. On the other hand, if the Tg point is less than -60°C, it is too soft and the shear adhesive strength and tensile adhesive strength are extremely reduced. The composition for setting the Tg point of the copolymer in the range of -30 to -60°C can be achieved by combining only an alkyl acrylate having an alkyl group with 4 to 8 carbon atoms and an ethylenically unsaturated monomer containing a carboxyl group. However, it is also possible to use them together with other vinyl monomers that can be copolymerized. Other monomers generally applicable to this include, for example, methyl acrylate, ethyl acrylate, methyl methacrylate, vinyl acetate, styrene, acrylonitrile, cyclohexyl acrylate, glycidyl acrylate, glycidyl methacrylate, N-methylol acrylamide, acrylamide, lauryl methacrylate, etc. be. The amount of these monomers used is such that the Tg point of the copolymer produced is -30 to -60.
Any amount within the range of °C can be used, and it is difficult to make a general decision. In addition, known chain transfer agents, plasticizers, etc. can be added during polymerization as necessary to adjust the hardness of the resin within the scope of the present invention. The Tg point is the temperature at which various properties of an amorphous polymer suddenly change, and it is said that below this temperature, the motion of the molecular segments of the amorphous portion of the polymer is frozen. To actually measure the Tg point of the copolymer of the present invention, for example, the thermal expansion at various temperatures is measured and the Tg point is determined as the intersection of two straight lines with different slopes of the specific volume-temperature curve. Desired. However, for convenience, since the Tg point value of the homopolymer of each monomer constituting the copolymer is known, the Tg point of the copolymer can be calculated using the following formula. I can do it. 1/Tg=C _A /Tg _A +C _B /Tg _B ...(1) C _A : Weight fraction of component A C _B : Weight fraction of component B Tg _A : Glass transition temperature of component A homopolymer ( 〓) Tg _B : Glass transition temperature of component B homopolymer (〓) Tg: Glass transition temperature of component A, B copolymer (〓) Here, C _A +C _B =1. Tg point of acrylic copolymer in the present invention
The range from 30℃ to -60℃ is for each individual homopolymer listed above.
This range is based on calculations from the Tg point. The Tg points of typical homopolymers of monomers are as follows. Homopolymer Tg point polymethyl acrylate 8℃ Polymethyl methacrylate 105℃ Polyethyl acrylate -23℃ Poly n-butyl acrylate -54℃ Poly i-butyl acrylate -24℃ Polycyclohexyl acrylate 16℃ Poly 2-ethylhexyl acrylate - 85℃ Polymethacrylic acid 144℃ Polystyrene 100℃ Polyvinyl acetate 30℃ Polyacrylonitrile 96℃ [] Disproportionated rosin ester with a softening point in the range of 70 to 130℃ Rosin compounds include rubber, ethylene vinyl acetate copolymer, etc. Although it is a useful compound as a tackifier, it has problems with compatibility with acrylic polymers.
When used in combination with an acrylic polymer, the dried film becomes opaque and cloudy, making it difficult to obtain a homogeneous film. The present inventors have conducted extensive searches for rosin compounds that are highly compatible with acrylic polymers and do not yellow or deteriorate due to heating, etc., and have found that disproportionated rosin esters are extremely compatible with the acrylic copolymers of the present invention. It was found that it has good solubility and no deterioration such as yellowing. Moreover, it has a particularly high softening point among disproportionated rosins.
The disproportionated rosin ester compound in the range of 70 to 130°C is mixed with the acrylic copolymer of the present invention in the range of acrylic copolymer/disproportioned rosin ester = 50 to 95/50 to 5 (weight ratio). It has been found that when used in combination, it exhibits excellent adhesion to various materials, especially polyolefins. This can be obtained for the first time by combining the acrylic copolymer of the present invention and the disproportionated rosin ester of the present invention. Disproportionated rosin ester is also called disproportionated rosin ester, and is produced by performing disproportionation treatment at high temperature to remove radical-unstable double bonds from the rosin compound, and then esterifying it. Esterified products with polyhydric alcohols such as , glycol ester, and pentaerythritol ester are known. The disproportionated rosin ester used in the present invention is limited to those whose softening point is in the range of 70 to 130°C,
A temperature range of 90 to 125°C is preferred. The acrylic copolymer in the present invention has a Tg point of −30 to
Since it is soft at -60°C, if the softening point is less than 70°C, the resulting adhesive will be too soft and its heat resistance will decrease, which is not preferable. Furthermore, if the softening point exceeds 130°C, the adhesive becomes hard, resulting in poor room temperature adhesion and peel strength. The softening point of the disproportionated rosin ester in the present invention is a value measured by the ring and ball method. In addition, the blending ratio of the acrylic copolymer and rosin ester in the present invention is acrylic copolymer/rosin ester.
Disproportionated rosin ester = 50-95/50-5 (weight ratio)
It is. Disproportionated rosin ester usage amount is 5% by weight
If it is less than 50% by weight, the adhesion to polyolefin and heat resistance will be poor, and if it exceeds 50% by weight, the dried film will become cloudy and the peeling adhesive strength will be significantly reduced. The tendency is to use disproportionated rosin esters with softening points close to 130℃ for acrylic copolymers with Tg points close to -60℃, and vice versa for acrylic copolymers with Tg points close to -30℃. It is preferable to use a disproportionated rosin ester with a softening point close to 70°C, and the blending ratio is preferably acrylic copolymer/disproportioned rosin ester = 60-90/40-10 (weight ratio). Things become a balanced glue. Furthermore, considering the combination ratio of both the Tg point of the acrylic copolymer and the softening point of the disproportionated rosin ester, the most preferable ratio is -35 to -50.
100-120° C. Acrylic copolymer/disproportioned rosin ester = 60-80/40-20 (weight ratio). In particular, if heat resistance is required, use the above [] + []
Up to 3% by weight of the aziridine compound can be added to the total amount of aziridine. If it is added in an amount exceeding 3% by weight, the adhesive becomes extremely hard and does not exhibit good adhesion, and the stability of the adhesive deteriorates, causing breakage or thickening of the emulsion during storage, which is not preferable. A more preferable addition amount is 0.01 to 1% by weight. What is the aziridine compound mentioned here?

A polyfunctional aziridine compound having two or more [formula], and the corresponding compound is (diphenylmethane-bis-4,4'-N,N'-
diethylene urea), (2,2-bishydroxymethylbutanol-
Tris[3-(1-aziridine)propionate] (1,6-hexamethylene diethylene urea)

[Formula] [Tris(1-aziridinyl)phosphine oxide]

[Formula] [2,4,6-(triethyleneimino)-syn-
triazine]

[Formula] (2,4-diethyleneuryatoluene) and the like. These aziridine compounds very easily react with the carboxyl groups in the acrylic copolymer of the present invention, resulting in crosslinking. Therefore, when an appropriate amount of the aziridine compound is used, appropriate crosslinking occurs and heat resistance is improved without reducing peel adhesion. To produce the adhesive composition of the present invention, a monomer mixture containing an alkyl acrylate according to the present invention and a carboxyl group-containing ethylenically unsaturated monomer is prepared by a known method, for example, in water. The mixture is emulsified with an anionic emulsifier such as sodium lauryl sulfate, and a persulfate such as ammonium persulfate,
Emulsion polymerization is carried out using a known polymerization initiator such as t-butyl hydroperoxide. Then, a separately known method, for example, a method of dissolving the disproportionated rosin ester in a solvent such as toluene or xylene, emulsifying it with an anionic emulsifier or a strong nonionic emulsifier, and then removing the solvent, or a method of removing the solvent, or using a small amount of the above-mentioned The disproportionated rosin ester of the present invention is emulsified by a method such as adding an anionic emulsifier to the solvent and the disproportionated rosin ester under high pressure (making the boiling point of water higher than the softening point) and forcibly emulsifying the solvent. After mixing the ingredients in a predetermined ratio, adding an aziridine compound as necessary to produce, or dissolving or dispersing the disproportionated rosin ester of the present invention in the corresponding monomer mixture, and then producing in the same manner. Emulsify with an emulsifier and emulsion polymerize. A method of manufacturing by adding a predetermined amount of an aziridine compound to the emulsion thus obtained can also be adopted. The particle size of the emulsified disproportionated rosin ester in the present invention is preferably 1 μm or less. Further, as the aqueous medium in the present invention, water and other known aqueous media used in aqueous emulsions can be used. In addition, when the adhesive composition of the present invention is actually used for bonding, especially when mechanical stability is required, such as when applying it to an adherend material using a roll coater, spray, etc., a suitable neutralizing agent such as ammonia may be added. water,
The PH of the system can be adjusted with NaOH water, etc., or if foaming, repelling, etc. during application is undesirable, an appropriate antifoaming agent, leveling agent, thickening agent, etc. can be added. It is also possible to add a melting point lowering agent that is effective in a small amount to provide freeze stability, and a low boiling point volatile solvent that is effective in a small amount to improve drying properties during use. The adhesive composition of the present invention is a water-based emulsion type, but when used as a contact adhesive, it has an adhesive strength equal to or greater than that of a solvent-based contact adhesive prepared by dissolving chloroprene rubber in a solvent. It is water resistant and heat resistant, and can provide strong adhesion to polyolefin that cannot be obtained with solvent-based contact adhesives. Moreover, since it does not contain volatile solvents, it does not contaminate the working environment, have an adverse effect on the human body, or cause fires. The danger of this is also prevented. The adhesive composition of the present invention is used for adhering polyolefins such as polyethylene and polypropylene, and can be used for adhering polyolefins to other materials such as wood, plywood, paper, cotton cloth, boards, iron, etc. , metals such as aluminum and stainless steel, hard PVC, ABS,
Plastics such as polystyrene, polycarbonate, polymethyl methacrylate, and phenolic resin, synthetic rubber, leather such as natural leather, mortar,
It can also be applied to bonding with slate, concrete, etc. Furthermore, the adhesive composition of the present invention to which an aziridine compound is added has even better heat resistance. Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, unless otherwise specified, parts and percentages are expressed on a weight basis, and viscosity, T-peel adhesive strength,
The 180° peel adhesive strength and tensile shear adhesive strength were measured by the following method. <Viscosity> Conforms to JIS K6833. However, the rotation time is 90 seconds. Measurement conditions Viscometer: B type viscometer (BM type) Rotor number: #4 Rotation speed: 60r.pm Measurement temperature: 20℃ (unless otherwise specified) <T peel adhesive strength / 180℃ peel adhesive strength> Conforms to JIS K6854. However, the tensile speed using the testing machine shall be 300 mm/min. The method of making the test piece and the bonding conditions are as follows unless otherwise specified. An adhesive composition is applied to the surface to be bonded of each of the two types of test pieces, and after drying at room temperature for 60 minutes, the coated surfaces of both pieces are pasted together, cut into a 25 mm width, and compressed with a 5 kg roller. Unless otherwise specified, measurements are performed after being left at room temperature for one day. <Tensile shear adhesive strength> Conforms to JIS K6851. However, the tensile speed by the testing machine shall be 50 mm/min. The method of making the test piece and the bonding conditions are as follows. 25mm
The adhesive composition was applied to a test piece of 300 mL in width, and after drying at room temperature for 60 minutes, the two coated surfaces were pasted together, compressed with a 5 kg roller, and left at room temperature for 1 day before measurement. Example 1 50 parts of 2-ethylhexyl acrylate (hereinafter referred to as "HA"), 25 parts of butyl acrylate (hereinafter referred to as "BA"), 25 parts of styrene (hereinafter referred to as "St"), methacrylic acid (hereinafter referred to as "MAA") 3 parts of glycidyl methacrylate (hereinafter referred to as "GMA"), 0.5 parts of glycidyl methacrylate (hereinafter referred to as "GMA") and 0.2 parts of dodecyl mercaptan (hereinafter referred to as "DM")
4 parts of polyoxyethylene nonyl phenyl ether sodium sulfate and 25 parts of water were added to the mixture consisting of 1 part of polyoxyethylene nonyl phenyl ether,
I made a pre-emulsion. Separately reflux condenser,
Add 38 parts of water to a reaction vessel equipped with a thermometer and stirrer.
After purging the inside of the reaction vessel with nitrogen, the temperature was raised to 80℃, and
% ammonium persulfate water (hereinafter referred to as "APS water") was added, and then 2% of the total amount of the pre-emulsion was added to initiate polymerization. followed by the remainder of the pre-emulsion (98% of the total amount) and
8 parts of APS water was continuously added dropwise at a temperature of 80±1°C for 3 hours, and after completion of the addition, the same temperature was further maintained for 1 hour to complete polymerization, and the mixture was cooled to room temperature to obtain an aqueous emulsion of the polymer. . The solid content of this product is 57.8%.
The pH was 2.1, the viscosity was 280 cps, and the Tg point of the polymer was -46°C. Example 2 80 parts of BA, methyl acrylate (hereinafter "MA")
(hereinafter referred to as "N-MAM") 20 parts, MAA 3 parts, N-methylolacrylamide (hereinafter referred to as "N-MAM")
A polymer emulsion was obtained in the same manner as in Example 1 except that a mixture of 0.1 part of DM and 0.09 part of DM was used. The solid content of this product is 57.1%, the PH is 1.9, and the viscosity is 520 cps.
The Tg point of the polymer is -41°C. Example 3 80 parts of BA, 20 parts of MA, 5 parts of cyclohexyl acrylate (hereinafter referred to as "CHA"), 5 parts of vinyl acetate (hereinafter referred to as "VAc"), and 3 parts of MAA,
A polymer emulsion was obtained in the same manner as in Example 1 using a mixture consisting of 0.1 part of N-MAM. The solid content of this product is 60.3%, PH = 2.1, viscosity 380cps/25
℃, the Tg point of the polymer was -36℃. Example 4 95 parts of BA, acrylic acid (hereinafter referred to as "AA")
A mixture consisting of 5 parts (of the resulting polymer)
Example 1: 30 parts of glycerin ester of disproportionated rosin (trade name: Super Ester A-100, manufactured by Arakawa Chemical Co., Ltd.) having a softening point of 100°C was dissolved in a solution (Tg point is -49°C).
Emulsion polymerization was carried out in the same manner. The solid content of this thing is 50.3
%, PH was 2.2, and viscosity was 620 cps. This is 10
The pH was adjusted to 6.8 with % ammonia water. Example 5 BA50 part, MA30 part, St20 part, MAA3 part,
A mixture consisting of 0.15 parts of DM was emulsion polymerized in the same manner as in Example 1. The solid content of this product is 55.1%, and the pH is
1.7, viscosity 210 cps, and Tg point of the polymer is -13°C. 60 parts of the polymer emulsion obtained in Example 2 were mixed with 40 parts of this polymer emulsion. The solid content of this product is 56.2%, the pH is 1.8, the viscosity is 330cps,
The Tg point of the polymer is -30°C. Examples 6 to 10 Emulsions of glycerin esters of disproportionated rosin with a softening point of 100°C (Arakawa), which were pre-emulsified with 80 parts of the polymer emulsions obtained in Examples 1, 2, 3, and 5 with an anionic emulsifier (Arakawa). Kagaku Co., Ltd. product name
KE-707) (solid content 45%, PH=4.5, viscosity 46cps/
25℃) were mixed to form an adhesive. The following tests were conducted using these adhesives and the adhesive composition obtained in Example 4. The adhesive composition was applied at a coating weight of 50 g/m ² (dry).
It was applied to both a 0.5 mm thick polyethylene sheet (hereinafter referred to as "PE sheet") and a 0.3 mm thick aluminum sheet (hereinafter referred to as "Al sheet"), and the T-peel adhesive strength was measured under the conditions described above. 1 result was obtained.

[Table] Examples 11 to 14 80 parts of the polymer emulsion obtained in Example 2 were mixed with 20 parts of disproportionated rosin ester emulsions having various softening points that had been emulsified in advance with an emulsifier, and the mixture was mixed with Example 6. Similarly, T of PE sheet/Al sheet
The peel adhesive strength was measured and the results shown in Table 2 were obtained.

[Table] Example 15 to Example 17, Comparative Example 1 to Comparative Example 2 Example 1 to the polymer emulsion obtained in Example 1
By changing the mixing ratio of the disproportionated rosin ester emulsion used in step 13, we tested the 180° peeling bond strength of PE sheet/1 mm thick hard PVC (hereinafter referred to as "PVC") and the tensile shear bond between 3 mm thick veneers. The strength was measured at room temperature (normal state) and after heating at 60°C for 30 minutes (heat resistant) and is shown in Table 3.

【table】

【table】

[Table] Examples 18 to 22, Comparative Example 3 To 100 parts of the adhesive composition obtained in Example 7, diphenylmethane-bis-4,
Using a system containing 0 to 1.8 parts of 4'-N,N'-diethylene urea, 50g/ ^m2 (dry) of the adhesive composition was applied to both a 50μ thick OPP film (stretched polypropylene film) and an Al sheet. After adhesion was performed, the normal state and heat resistance (60°C x 30 minutes, heated) were measured, and the results shown in Table 4 were obtained.

[Table] Example 23 The adhesive composition obtained in Example 19 was used to adhere various polyolefins/mortars, and the normal adhesive strength after 7 days of adhesion, the heat-resistant adhesive strength under heating after heating at 60°C for 30 minutes, and the saturation It was immersed in calcium hydroxide water (PH=11.2) for 5 days and the water resistant adhesive strength in the wet state was measured.
A result of 5 was obtained.

[Table] Example 24 To 75 parts of the polymer emulsion obtained in Example 3, an emulsion of glycerin ester of disproportionated rosin with a softening point of 100°C (solid content 45% PH 5.8, viscosity 15 cps/
25℃) and mix 25 parts as an aziridine compound.
2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate]
Added 0.05 parts and further adjusted the pH to 7.3 with 10% ammonium water and adjusted the viscosity to 5800 cps/25°C with a polyacrylic acid thickener (trade name Aron B-300, manufactured by Toagosei Kagaku Kogyo Co., Ltd.). as a drug. Apply this adhesive only to the polyolefin side at a coating amount of 50 g/m ² (dry).
It was dried at 100℃ for 5 minutes, pasted on various adherends, peeled off at 180℃ after one day, and measured the adhesive strength.
6 results were obtained.

[Table] Comparative Example 4 A monomer mixture consisting of 80 parts of HA, 20 parts of MA, and 3 parts of MAA was emulsion polymerized in the same manner as in Example 1, and the solid content was
55.0%, PH=1.9, viscosity 350cps, Tg point of polymer -
A polymer emulsion at 69°C was obtained. To 70 parts of this emulsion was added 30 parts of the disproportionated rosin ester used in Example 12, and to this was added 0.5 parts of the aziridine compound used in Example 18.
Sheet/mortar, normal condition, heat resistance, water resistance (example
Table 7 shows the results of measurements under the same conditions as No. 23. Coating amount, PE sheet side 50g/m ² (dry) Mortar side 100g/m ² (dry)

[Table] Comparative Example 5 Using the same adhesive as Comparative Example 4 (coating amount, 100 g/m ²
The dry) veneers were bonded together, and the tensile shear adhesion strength under normal conditions, heat resistance, and water resistance was measured as in Comparative Example 4, and the results are shown in Table 8.

[Table] Comparative example 6 50 parts of BA, 30 parts of MA, 20 parts of methyl methacrylate
A mixture of 3 parts of MAA and 3 parts of MAA was emulsion polymerized in the same manner as in Example 1 to obtain a solid content of 52.3%, pH of 1.6, and viscosity of
A polymer emulsion of 620 cps and a Tg point of the polymer of -12°C was obtained. Example 13: 70 parts of this emulsion
A 0.3 mm thick PE sheet and an Al sheet were bonded using a mixture of 30 parts of the rosin ester emulsion used in 1. Further 60℃
Heating it for 30 minutes and checking the T-peel strength under heating.
The adhesive strength improved to 2.2Kg/25mm, but when this product was cooled to room temperature and measured, it was 1.4Kg/25mm.

Claims (1)

[Claims] 1 Consists of an aqueous medium and a resin, the resin component being 50 to 95% by weight of an acrylic copolymer shown in [] below and 50 to 5% by weight of a disproportionated rosin ester shown in [] below. % aqueous emulsion type adhesive composition for polyolefin. [] Copolymerized with an alkyl acrylate having an alkyl group having 4 to 8 carbon atoms and an ethylenically unsaturated monomer containing a carboxyl group, or these and other vinyl monomers copolymerizable with these, resulting in glass transition Acrylic copolymer with a temperature range of -30 to -60℃. [] Disproportionated rosin ester with a softening point in the range of 70 to 130°C.