JP2003096420A - Emulsive adhesive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an emulsive adhesive composition that has excellent polymerization stability, emulsion shelf stability and excellent adhesion (particularly, adhesion to a polyolefin), tenacity, resistant to water (particularly, whitening resistance to water). SOLUTION: The oil-soluble components including (A) ethylenically unsaturated monomers mainly comprising (meth)acrylic alkyl ester (a1) and (B) a tackifier is emulsified in an aqueous medium by using (C) an emulsifier so that the average particle size of the oil-soluble components may become <=1.0 μm. The monomer component in the emulsion [I] is polymerized in the presence of (D) a polymerization initiator and further (E) an ethylenically unsaturated monomers mainly comprising (meth)acrylic alkyl ester (e1) is polymerized in the presence of the resultant resin emulsion [II] to give the objective emulsion type adhesive composition.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an emulsion-type pressure-sensitive adhesive composition, and more specifically to adhesiveness (particularly adhesion to polyolefin), holding power, substrate adhesion, and water resistance (particularly water whitening resistance). The present invention relates to an excellent emulsion-type pressure-sensitive adhesive composition.

[0002]

2. Description of the Related Art Acrylic ester copolymer emulsions can be used as an adhesive or an adhesive because the balance of adhesiveness (or adhesiveness) and cohesive force can be changed by changing the composition. . And in this case, in order to improve adhesiveness (or tackiness), it is widely performed to add tackifying resin.

However, since the tackifying resin is insoluble in water, there are a method of dissolving it in a solvent and adding it and a method of emulsifying it in water and adding it as an emulsion. In the former case, the advantage as an aqueous system is lost, and in the latter case, the tackifying resin is used. Since the particles of and the particles of acrylic emulsion do not mix uniformly,
The resulting adhesives and pressure-sensitive adhesives often have problems that their adhesiveness is lowered and their water resistance is also lowered.

In order to solve such a problem, (1) Japanese Patent Application Laid-Open No. 54-23641 discloses an acrylic monomer,
A water-dispersible adhesive composition obtained by emulsion-polymerizing an emulsion containing a crosslinkable functional group-containing copolymerizable monomer, a polymer compound previously dissolved in at least one of the two components, and a surfactant is (2) ) JP-A-58-18566
No. 8 discloses a compound in which a tackifying resin is dissolved or dispersed in a mixture of a crosslinkable monomer and (meth) acrylate,
Or, an emulsion composition obtained by dispersing this composition in water containing an emulsifier, in a polymerization liquid containing water, an emulsifier and a polymerization catalyst,
Copolymer emulsion type adhesives obtained by conducting polymerization while continuously adding each have been proposed.

Further, (3) Japanese Patent Laid-Open No. 2000-313865
According to the publication, 50 to 99.5% by weight of an alkyl (meth) acrylate in which the alkyl group has 9 to 14 carbon atoms, a monomer having a carboxyl group, a hydroxyl group, or an amide group.
0.5 to 5 parts by weight of a tackifying resin and an oil-soluble polymerization initiator are dissolved in 100 parts by weight of a mixed monomer containing 5 to 2.5% by weight, and this is emulsified and dispersed in an emulsifier aqueous solution to obtain an average particle diameter. An emulsion-type pressure-sensitive adhesive obtained by polymerizing after forming monomer oil droplets of 1 μm or less has been proposed.

[0006]

However, the techniques disclosed in the above (1) and (2) have not examined the method of emulsifying and dispersing a mixed liquid in which a tackifying resin is dissolved or dispersed, and the present inventors However, as a result of a detailed examination, when the polymerization was carried out using an emulsion liquid which was emulsified and dispersed by a usual method, the polymerization became unstable when the amount of the tackifying resin used increased, and the stability of the resulting emulsion was lowered. Turned out to be a problem. In addition, the above (1)-
The disclosed technique of (3) is not yet satisfactory in terms of adhesiveness (particularly adhesion to polyolefin), substrate adhesion, and water resistance (particularly water whitening resistance), and further improvement is desired. .

Therefore, in the present invention, under such a background, the adhesiveness (particularly the adhesiveness to polyolefin),
It is an object of the present invention to provide an emulsion-type pressure-sensitive adhesive composition having excellent holding power, substrate adhesion, and water resistance (particularly water whitening resistance).

[0008]

However, the inventors of the present invention have conducted diligent research to solve the above-mentioned problems, and as a result, have found that ethylenically unsaturated monomer having (meth) acrylic acid alkyl ester (a1) as a main component is used. Body (A) and tackifier (B)
The emulsified liquid [I] obtained by emulsifying the oil-soluble component consisting of (1) with an emulsifier (C) in an aqueous medium so that the average particle diameter of the oil-soluble component is 1.0 μm or less is used as a polymerization initiator (D). In the presence of a resin emulsion [II] obtained by polymerization in the presence of a), (meth) acrylic acid alkyl ester (e)
The present invention has been completed by finding that an emulsion type pressure-sensitive adhesive composition obtained by polymerizing an ethylenically unsaturated monomer (E) containing 1) as a main component meets the above object.

In the present invention, the ethylenically unsaturated monomer (E) contains a carboxyl group-containing unsaturated monomer (e2), or a carboxyl group-containing unsaturated monomer (e2). And a crosslinkable group-containing unsaturated monomer (excluding the carboxyl group-containing unsaturated monomer (e2)) (e
It is preferable that 3) is contained in terms of substrate adhesion and water whitening resistance. Further, in the present invention, when the crosslinking agent (F) is further added, the effect of the present invention is remarkably exhibited.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. The ethylenically unsaturated monomer (A) used in the present invention contains a (meth) acrylic acid alkyl ester (a1) as a main component, and as the (meth) acrylic acid alkyl ester (a1), , For example,
Methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-hexyl (meth) acrylate, 2- (Meth) acrylic acid alkyl ester having 1 to 8 carbon atoms in the alkyl group such as ethylhexyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, isooctyl (meth) acrylate, and n-octyl (meth) acrylate. Or nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, isododecyl (meth) acrylate, lauryl (meth) acrylate Relate, tridecyl (meth) acrylate, isotridecyl (meth) acrylate, tetradecyl (meth) number of carbon atoms in the alkyl group of the acrylate 9 or more (meth) acrylic acid alkyl ester. Among them, the number of carbon atoms of the alkyl group is 1 to
8 (meth) acrylic acid alkyl ester is preferable,
Particularly, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl acrylate are preferably used.

The ethylenically unsaturated monomer (A) may contain a crosslinkable monomer (a2),
Examples of the crosslinkable monomer (a2) include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an epoxy group-containing monomer, an alkoxysilyl group-containing monomer, an amide group and a methylol group, Examples thereof include a monomer having a keto group and a polyfunctional monomer.

Examples of the carboxyl group-containing monomer include acrylic acid, acrylic acid dimer, methacrylic acid, crotonic acid, itaconic acid and maleic acid. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. As the epoxy group-containing monomer, glycidyl (meth)
Examples thereof include acrylate and allyl glycidyl ether.

As the alkoxysilyl group-containing monomer, γ- (meth) acryloxyethyltrimethoxysilane, γ- (meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ -(Meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyldimethylmethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (Meth) acryloxypropyldimethylethoxysilane, γ- (meth) acryloxypropyltrichlorosilane, γ- (meth) acryloxypropylmethyldichlorosilane, γ- (meth) acryloxypropyldimethylchlorosilane, γ- (meth) acryl Roxypropyl tryp Piokishishiran, γ
-(Meth) acryloxypropylmethyldipropoxysilane, γ- (meth) acryloxypropyltributoxysilane, γ- (meth) acryloxybutyltrimethoxysilane, γ- (meth) acryloxypentyltrimethoxysilane, γ -(Meth) acryloxyhexyltrimethoxysilane, γ- (meth) acryloxyhexyltriethoxysilane, γ- (meth) acryloxyoctyltrimethoxysilane, γ- (meth) acryloxydecyltrimethoxysilane, γ- ( (Meth) acryloxydodecyltrimethoxysilane, γ- (meth) acryloxyoctadecyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripolopoxysilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, vinyl Chill dipropoxy silane, and the like.

Examples of the monomer containing an amide group, a methylol group and a keto group include acrylamide, methacrylamide, N-methylol acrylamide, butoxy N-methylol acrylamide, diacetone acrylamide,
2- (acetoacetoxy) ethyl (meth) acrylate, allyl acetoacetate and the like can be mentioned.

As the polyfunctional monomer, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, Dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate,
1,6-hexanediol di (meth) acrylate,
1,9-Nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, glycerin methacrylate Examples thereof include acrylate, tris (meth) acryloyloxyphosphate, glycerin di (meth) acrylate, diallyl terephthalate, tetraallyloxyethane, divinylbenzene, and tri (meth) allyl isocyanurate. These crosslinkable monomers (a2) are used alone or in combination of two or more.

Among the above, acrylic acid, methacrylic acid, itaconic acid, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ -Methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, vinyltriethoxysilane, N-methylol acrylamide, diacetone acrylamide, 2- (acetoacetoxy) ethyl methacrylate, propylene glycol di (meth) acrylate, di Propylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) Acrylate, triethylene glycol di (meth) acrylate, diallyl terephthalate, divinylbenzene and the like are particularly preferably used.

In the present invention, it is also possible to use other copolymerizable monomer (a3), and as such copolymerizable monomer (a3), acrylonitrile, methacrylonitrile, styrene, α- Methylstyrene, vinyl acetate, vinyl propionate, vinyl chloride, alkyl vinyl ether, dimethylaminoethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, etc. Can be mentioned.

In the above ethylenically unsaturated monomer (A), a (meth) acrylic acid alkyl ester (a1), a crosslinkable monomer (a2) and a copolymerizable monomer (a3) are used. The content ratio of the (meth) acrylic acid alkyl ester (a1) is 50 to 100% by weight, the crosslinkable monomer (a2) is 0 to 20% by weight, and the copolymerizable monomer (a3) is 0. It is preferably ˜50 wt%, more preferably (meth) acrylic acid alkyl ester (a
70% to 100% by weight of 1) and a monomer (a
2) is 0 to 10% by weight, the copolymerizable monomer (a3) is 0 to 30% by weight, particularly preferably (meth) acrylic acid alkyl ester (a1) is 80 to 100% by weight,
The crosslinkable monomer (a2) is 0 to 5% by weight, and the copolymerizable monomer (a3) is 0 to 20% by weight.

(Meth) acrylic acid alkyl ester (a
If the content of 1) is less than 50% by weight, sufficient adhesive strength and tack may not be obtained, or the transparency of the coating film may decrease, which is not preferable. 20% by weight of crosslinkable monomer (a2)
If it exceeds the range, the transparency of the coating film may be deteriorated or the polymerization may become unstable, which is not preferable. Copolymerizable monomer (a
When the content of 3) exceeds 50% by weight, the adhesive strength and tack may be lowered, and the transparency of the coating film may be lowered, which is not preferable.

The tackifier (B) used in the present invention may be any one which can be dissolved or dispersed in the ethylenically unsaturated monomer (A). For example, "super ester A-"
75 "(manufactured by Arakawa Chemical Co., Ltd.)," Super Ester A-10 "
0 "(manufactured by Arakawa Chemical Co., Ltd.)," Super Ester A-12 "
5 "(Arakawa Chemical Co., Ltd.) and other rosin esters," Pencel D125 "(Arakawa Chemical Co., Ltd.)," Pencel D160 "
(Manufactured by Arakawa Chemical Co., Ltd.), polymerized rosin ester such as "Ritakac PCJ" (manufactured by Rika Finetech Co., Ltd.), "Nikanor HP-100" (manufactured by Mitsubishi Gas Chemical Co., Inc.), "Nikanor H"
P-150 "(manufactured by Mitsubishi Gas Chemical Co., Inc.)," Nicanol H-
Xylene resin such as “80”, “YS Polystar T-11
5 "(manufactured by Yasuhara Chemical Co., Ltd.)," Mytec G12
5 "(Yasuhara Chemical Co., Ltd.) and other terpene phenolic resins," FTR-6120 "(Mitsui Petrochemical Co., Ltd.),
Examples thereof include petroleum resins such as “FTR-6100” (manufactured by Mitsui Petrochemical Co., Ltd.), coumarone indene resin, terpene resin, styrene resin, ethylene / vinyl acetate resin, and the like.

Further, styrene-butadiene block polymer, styrene-isoprene block polymer, ethylene-isoprene-styrene block polymer, vinyl chloride / vinyl acetate polymer, acrylic rubber and the like, which are called elastomers, can also be used.

In the present invention, the above ethylenically unsaturated monomer (A) and the tackifier (B) are mixed to form an oil-soluble component. The mixing ratio is such that the ethylenically unsaturated monomer ( A) The tackifier (B) is 5 to 100 parts by weight.
It is preferably 400 parts by weight, more preferably 8 parts.
˜300 parts by weight, particularly preferably 10 to 200 parts by weight. If the tackifier (B) is less than 5 parts by weight, sufficient adhesiveness, particularly adhesiveness to polyolefin, cannot be obtained.
If it exceeds 100 parts by weight, the polymerization becomes unstable, and sufficient adhesiveness and tack cannot be obtained, which is not preferable.

An oil-soluble component containing an ethylenically unsaturated monomer (A) and a tackifier (B) is emulsified in an aqueous medium with an emulsifier (C) to obtain an emulsion [I]. The emulsifier (C) to be prepared is not particularly limited as long as it has a function of emulsifying each component in an aqueous medium, and examples thereof include a reactive (ionic or nonionic) surfactant. A non-reactive (ionic or non-ionic) surfactant or the like is used alone or in combination. Above all, in consideration of water resistance, it is preferable to use a reactive surfactant.

The reactive surfactant may be any ionic or nonionic surfactant having radical reactivity with the ethylenically unsaturated monomer (A), and as the reactive surfactant, For example, those having a structure represented by the following general formulas (1) to (7) can be mentioned.

[0025]

[Chemical 1]

[0026]

[Chemical 2]

[0027]

[Chemical 3]

[0028]

[Chemical 4]

[0029]

[Chemical 5]

[0030]

[Chemical 6]

[0031]

[Chemical 7]

[In the general formulas (1) to (7), R ₁ is an alkyl group, R ₂ is hydrogen or a methyl group, R ₃ is an alkylene group, n is an integer of 1 or more, and m and l are 1 The above integer (m + 1 = 3), X is hydrogen, SO ₃ NH ₄ , SO ₃ Na
Is one of. ]

Specific examples of the above-mentioned surfactant include "ADEKA REASOAP SE-20N" (anionic), "ADEKA REASOAP SE-10N" (anionic), and "ADEKA REASOAP NE-10" (nonionic). ), "Adeka rear soap NE-20" (nonionic), "Adeka rear soap NE-30" (nonionic), "Adeka rear soap NE"
-40 "(nonionic)," Adeka rear soap SDX-
730 "(anionic)," ADEKA REASOAP SDX- "
731 "(anionic) [above, manufactured by Asahi Denka Co., Ltd.],
"Eleminol JS-2" (anionic), "Eleminol RS-30" (anionic) [above, Sanyo Kasei Co., Ltd.], "Latemul S-180A" (anionic), "Latemul S-180" ( Anionic) [above,
Kao Corporation], "Aqualon BC-05" (anionic), "Aqualon BC-10" (anionic), "Aqualon BC-20" (anionic), "Aqualon H"
S-05 "(anionic)," Aqualon HS-10 "
(Anionic), "Aqualon HS-20" (anionic), "Aquaron RN-10" (nonionic), "Aquaron RN-20" (nonionic), "Aquaron R"
N-30 "(nonionic)," Aqualon RN-50 "
(Nonionic), "New Frontier S-510"
(Anions) [above, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.], "Phosphinol TX" (anionic) [manufactured by Toho Chemical Industry Co., Ltd.], and the like.

The amount of the emulsifier (C) blended is 0.5 to 10 parts by weight based on 100 parts by weight of the total of the ethylenically unsaturated monomer (A) and the tackifier (B). It is more preferably 0.8 to 7 parts by weight, and particularly preferably 1 to 5 parts by weight. If the emulsifier (C) is less than 0.5 parts by weight, it is difficult to make the particle diameter of the oil-soluble component less than 1 μm, and the polymerization becomes unstable. Is unfavorable because the water resistance of is decreased. The emulsifier (C) may be partially added to the polymerization vessel in advance, in addition to the emulsion [I].

Next, an ethylenically unsaturated monomer containing a (meth) acrylic acid alkyl ester (a1), a crosslinkable monomer (a2) and another copolymerizable monomer (a3). An emulsion obtained by emulsifying an oil-soluble component comprising (A) and a tackifier (B) with an emulsifier (C) in an aqueous medium so that the average particle diameter of the oil-soluble component is 1.0 μm or less. A method of obtaining [I] will be described.

As a method of charging each component, the tackifier (B) is dissolved in advance in the ethylenically unsaturated monomer (A),
It is preferable to charge other components. The amount of water used is
The total amount of the ethylenically unsaturated monomer (A) and the tackifier (B) is 100 parts by weight, preferably 70 to 500 parts by weight, more preferably 80 to 300 parts by weight,
It is particularly preferably 85 to 200 parts by weight. If the amount of water used is less than 70 parts by weight, the emulsion [I] has a high viscosity,
In addition, the polymerization stability is also lowered, and when it exceeds 500 parts by weight, the concentration of the emulsion [I] produced becomes low, and the concentration of the resulting emulsion-type pressure-sensitive adhesive composition becomes low, and It is not preferable because the drying property (when forming a film) is lowered.

The emulsion [I] is obtained by emulsifying an oil-soluble component comprising an ethylenically unsaturated monomer (A) and a tackifier (B) in an aqueous medium with an emulsifier. The average particle diameter of the oil-soluble component is 1.0 μm or less, preferably 0.05 to
It may be 0.7 μm, particularly preferably 0.1 to 0.5 μm. When the average particle diameter of the oil-soluble component in the emulsion [I] exceeds 1.0 μm, a large amount of aggregates are formed during polymerization, and the stability of the emulsion is left poor, resulting in poor adhesion of the coating film, particularly adhesion to polyolefin. Is not sufficient or the water resistance is lowered, and the effect of the present invention cannot be obtained.

The method of adjusting the average particle size of the oil-soluble component to 1.0 μm or less is not particularly limited, and the components are mixed,
The emulsification treatment may be carried out with any stirring device, emulsification device, etc., but particularly in the present invention, once the emulsion [I ′] having an average particle diameter of the oil-soluble component exceeds 1.0 μm, the oil-soluble component is then dissolved. It is preferable to use the emulsion [I] in which the average particle diameter of the components is 1.0 μm or less.

The emulsified liquid [I '] was prepared by mixing the respective components and preliminarily emulsifying the mixture using a stirring device equipped with a stirring blade such as a homodisper or a paddle blade.
An emulsion having a size of more than 0 μm is prepared.
Is further emulsified and the average particle size of the oil-soluble component is 1.0
It is preferable to use the emulsion [I] having a size of not more than μm.

The method of further dispersing the emulsion [I '] to obtain the emulsion [I] in which the average particle diameter of the oil-soluble component is 1.0 μm or less is not particularly limited, but it is not particularly limited, but it is a high-pressure homogenizer treatment or ultrasonic wave. And a method using an emulsifying device such as a hydroshear are preferable, and particularly, a high-pressure homogenizer treatment is preferable in that an emulsion having a narrow particle size distribution can be obtained efficiently. Pressure when using high pressure homogenizer is 10-15
Preferably to 00kg / cm ^2, more preferably 30~1000kg / cm ^2.

The temperature at the time of emulsification does not matter as long as the mixture does not react during the emulsification, and usually about 5 to 60 ° C. is suitable. The number of passages of the emulsion is 1
It is preferably about 5 times.

After the emulsion [I] is prepared, the emulsion [I] is polymerized in the presence of the polymerization initiator (D) to prepare the resin emulsion [II]. , The whole amount of the emulsion [I] is heated and polymerized as it is,
A part of the emulsion [I] is heated to start the polymerization, and the rest of the emulsion [I] (the polymerization initiator (D) is also dropped if necessary).
Is added dropwise or dividedly to continue the polymerization, and water (a part of the emulsifier (C) and the polymerization initiator (D) may be charged if necessary) is charged to the reaction vessel and the temperature is raised. After that, the whole amount of the emulsion [I] is added dropwise or dividedly added to perform polymerization, and the like. However, it is not limited to these.

The amount of the polymerization initiator (D) used is 0.05 to 100 parts by weight of the ethylenically unsaturated monomer (A).
It is preferably 5 parts by weight, and more preferably 0.1.
~ 3 parts by weight. If the amount of the polymerization initiator is less than 0.05 parts by weight, the polymerization rate will be slow, and if it exceeds 5 parts by weight, the molecular weight of the resin will be low and the holding power will be decreased, such being undesirable.

The polymerization initiator (D) is not particularly limited, and any of water-soluble and oil-soluble initiators can be used. Specific examples thereof include alkyl peroxide, t-butyl hydroperoxide and cumene. Hydroperoxide,
p-methane hydroperoxide, isobutyl peroxide, laurolyl peroxide, 3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, t-butylcumyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, Dicumyl peroxide, di-t-butyl peroxide, 1,1-bis (t-butylperoxy) -3,
3,5-trimethylcyclohexane, 3,3,5-trimethylcyclohexanone peroxide, methylcyclohexanone peroxide, di-isobutylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, t-butylperoxyisobutyrate, etc. Organic peroxides, azobisisobutyronitrile, dimethylazodiisobutyrate, 2,2-azobis (2,4-
Dimethylvaleronitrile), 2,2-azobis (2-methylbutyronitrile), potassium persulfate, sodium persulfate, ammonium persulfate, hydrogen peroxide, ammonium of 4,4′-azobis-4-cyanovaleric acid ( Amine) salt, 2,2'-azobis (2-methylamidooxime) dihydrochloride, 2,2'-azobis (2-methylbutanamidooxime) dihydrochloride tetrahydrate, 2,2'-azobis {2-methyl -N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] -propionamide}, 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) -propionamide], various redox System catalyst (in this case, the oxidizing agent is ammonium persulfate, potassium persulfate,
Hydrogen peroxide, t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide and the like are used, and reducing agents include sodium sulfite, sodium acid sulfite, rongalite and ascorbic acid. ) And the like.

The polymerization initiator (D) may be added in advance in the polymerization vessel, may be added immediately before the start of the polymerization, or may be additionally added during the polymerization, if necessary. Then
Further, it may be added in advance to the mixed liquid of the ethylenically unsaturated monomer (A) and the tackifier (B) before emulsification, or may be added to the emulsified liquid [I] after the emulsification. Further, if necessary, a pH buffering agent may be used together during the polymerization in order to adjust the pH during the polymerization. Upon addition, the polymerization initiator (D) may be separately dissolved in a solvent and added, or the dissolved polymerization initiator (D) may be further emulsified and added.

The polymerization conditions in the above polymerization method are:
Although not particularly limited, for example, in the method of, usually 40
A suitable temperature range is about -100 ° C, and the reaction is carried out for about 0.5-8 hours after the start of temperature increase. In the above method, after polymerizing 5 to 95% by weight of the emulsion [I] at 40 to 90 ° C. for 0.1 to 5 hours or while polymerizing, the remaining emulsion [I]
Is added dropwise or dividedly over about 0.1 to 5 hours, and then aged at the same temperature for about 1 to 3 hours. In the method of
Water was charged so as to be 5 to 300% by weight of the emulsion [I], the temperature was raised to 40 to 90 ° C., and the emulsion [I] was added to 0.5 to 5%.
Add dropwise or in portions over a period of about 1 hour at the same temperature.
Aging for about 3 hours.

Thus, the resin emulsion [II] is obtained, and the average particle size of the resin component of the resin emulsion [II] is 0.05 to 0.5 μm, further 0.1 to 0.3.
It is preferable that the particles are μm. The resin concentration of the resin emulsion [II] is preferably 10 to 65% by weight, and particularly preferably 20 to 55% by weight.

In the present invention, such a resin emulsion [I
I], the emulsion-type pressure-sensitive adhesive composition is obtained by further polymerizing the ethylenically unsaturated monomer (E) containing the (meth) acrylic acid alkyl ester (e1) as a main component. .

The ethylenically unsaturated monomer (E) used in the present invention contains a (meth) acrylic acid alkyl ester (e1) as a main component, and such (meth)
Examples of the acrylic acid alkyl ester (e1) include the same as the above-mentioned (meth) acrylic acid alkyl ester (a1). Among them, the number of carbon atoms of the alkyl group is 1 to
8 (meth) acrylic acid alkyl ester is preferable,
Particularly, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl acrylate are preferably used.

The ethylenically unsaturated monomer (E) preferably contains a carboxyl group-containing unsaturated monomer (e2), or a carboxyl group-containing unsaturated monomer (e2) and crosslinkability. Group-containing unsaturated monomer (excluding carboxyl group-containing unsaturated monomer (e2)) (e3)
It is preferable to contain

Carboxyl group-containing unsaturated monomer (e2)
Examples thereof include the same as the carboxyl group-containing monomer of the above-mentioned crosslinkable monomer (a2). The crosslinkable group-containing unsaturated monomer [provided that the carboxyl group-containing unsaturated monomer ( Excluding e2)] (e3) includes a hydroxyl group-containing monomer, an epoxy group-containing monomer, an alkoxysilyl group-containing monomer of the above-mentioned crosslinkable monomer (a2),
Amide group, methylol group, monomer containing keto group,
Examples thereof include polyfunctional monomers, and it is particularly preferable to use a monomer having a keto group and a polyfunctional monomer.

Further, other copolymerizable monomer (e4)
It is also possible to use a copolymerizable monomer (e
Examples of 4) include the same as the above-mentioned copolymerizable monomer (a3).

In the ethylenically unsaturated monomer (E), (meth) acrylic acid alkyl ester (e1),
Carboxyl group-containing unsaturated monomer (e2), crosslinkable group-containing unsaturated monomer [excluding carboxyl group-containing unsaturated monomer (e2)] (e3), and copolymerizable monomer The content ratio of (e4) is 50 to 99% by weight of the (meth) acrylic acid alkyl ester (e1), 1 to 10% by weight of the carboxyl group-containing unsaturated monomer (e2), and a crosslinkable group-containing unsaturated monomer. The body (e3) is preferably 0 to 5% by weight, and the copolymerizable monomer (e4) is preferably 0 to 49% by weight,
More preferably, the (meth) acrylic acid alkyl ester (e1) is 70 to 98.45% by weight, the carboxyl group-containing unsaturated monomer (e2) is 1.5 to 8% by weight, and the crosslinkable group-containing unsaturated monomer is The body (e3) is 0.05 to 3% by weight, the copolymerizable monomer (e4) is 0 to 28.45% by weight, and particularly preferably the (meth) acrylic acid alkyl ester (e1) is 80 to 97.9% by weight, the carboxyl group-containing unsaturated monomer (e2) is 2 to 6% by weight, the crosslinkable group-containing unsaturated monomer (e3) is 0.1 to 2% by weight, and is a copolymerizable monomer. The amount of the monomer (e4) is 0 to 17.9% by weight.

(Meth) acrylic acid alkyl ester (e
If 1) is less than 50% by weight, sufficient adhesive strength and tack cannot be obtained, and if it exceeds 99% by weight, holding power, substrate adhesion and water whitening resistance are deteriorated. When the carboxyl group-containing unsaturated monomer (e2) is less than 1% by weight, sufficient adhesive strength, substrate adhesion and water whitening resistance cannot be obtained, and when it exceeds 10% by weight, the adhesive strength to polyolefin is lowered, Polymerization may be unstable. When the amount of the crosslinkable group-containing unsaturated monomer (e3) exceeds 5% by weight, the adhesive strength and tack are lowered and the water whitening resistance is lowered, which is not preferable. When the amount of the copolymerizable monomer (e4) exceeds 49% by weight, the adhesive force and tack are lowered, which is not preferable.

The polymerization of the ethylenically unsaturated monomer (E) in the presence of the resin emulsion [II] obtained above is not particularly limited, but (e1) to (e1)
From the viewpoint of polymerization stability, it is possible to polymerize the emulsion [a] obtained by pre-emulsifying the ethylenically unsaturated monomer (E) of (e4) in an aqueous medium in the presence of the resin emulsion [II]. preferable.

When the preliminarily emulsified emulsion [a] is obtained, it is preferable to use an emulsifier. Examples of the emulsifier include the same as the above emulsifier (C), and one or more of them may be used in combination. Used.

Further, when the emulsion [a] obtained by pre-emulsifying the ethylenically unsaturated monomer (E) is polymerized, the same polymerization initiator (D) as described above is used. The polymerization initiator (D) may be added in advance in the polymerization vessel, may be added immediately before the start of polymerization, or may be additionally added during the polymerization, if necessary. It may be added in advance to the mixed solution of (E) before emulsification, or may be added to the emulsified solution [a] after the emulsification. Upon addition, the polymerization initiator (D) may be separately dissolved in a solvent and added, or the dissolved polymerization initiator (D) may be further emulsified and added.

The method of charging each of the above components is not particularly limited, but a method of dissolving the emulsifier (C) in water and then charging the other components, or a mixed liquid of the ethylenically unsaturated monomer (E) A method in which the emulsifier (C) is dissolved in and then other components are charged is preferable.

The amount of the emulsifier (C) blended is preferably 0.3 to 7 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the ethylenically unsaturated monomer (E). It is a department. If it is less than 0.3 parts by weight, sufficient emulsification performance cannot be maintained and the polymerization stability is lowered, and if it exceeds 7 parts by weight, the adhesive strength, the substrate adhesive strength and the water resistance are lowered, which is not preferable.

The amount of water used is preferably 25 to 200 parts by weight, more preferably 30 to 150 parts by weight, and less than 25 parts by weight, relative to 100 parts by weight of the ethylenically unsaturated monomer (E). Then, the emulsion [a] has a high viscosity,
Further, the polymerization stability is also lowered, and if it exceeds 200 parts by weight, the concentration of the obtained emulsion is lowered and the drying property at the time of coating is lowered, which is not preferable.

Next, the emulsion [a] is heated in the presence of the resin emulsion [II] to start the polymerization. The amount of the polymerization initiator (D) used is ethylenically unsaturated. 0.03 to 5 parts by weight based on 100 parts by weight of the monomer (E),
It is particularly preferably 0.05 to 3 parts by weight. If the amount used is less than the above range, the polymerization rate becomes slow, and if it exceeds the above range, the molecular weight of the resin becomes low and the holding power is lowered, which is not preferable.

In the polymerization, for example, a method of mixing the resin emulsion [II] and the emulsion [a] and then heating the mixture as it is to carry out polymerization, or mixing a part of the emulsion [a] into the resin emulsion [II] Then, the temperature is raised to start the polymerization, and the whole amount of the remaining emulsion [a] is dropped or divided and continuously dropped to continue the polymerization, and the emulsion [a] is dropped in the presence of the resin emulsion [II]. Alternatively, there may be mentioned a method in which the polymerization is carried out by division or continuous dropping, but the method is not limited to these. The polymerization conditions are not particularly limited, but are usually 40 to 90.
It is preferably carried out in the range of about ° C.

After completion of the polymerization, the pH is adjusted to 5 to 9, preferably 6 to 8 by adding an alkaline solution such as aqueous ammonia, various water-soluble amines, aqueous sodium hydroxide and aqueous potassium hydroxide. An emulsion useful as the emulsion-type pressure-sensitive adhesive composition of the invention is obtained.

The particle size of such emulsion is 100 to 2
Fine particles of 50 μm, particularly 130 to 200 μm are preferable. In the emulsion obtained above, the content of the resin emulsion [II] is preferably 10 to 80% by weight, more preferably 20 to 60% by weight, based on the total solid content in terms of solid content. And particularly preferably 25 to 50% by weight. If the content is less than 10% by weight, the adhesive strength to polyolefin will be insufficient and 80
When the content is more than 10% by weight, the holding power is lowered and the water whitening resistance is lowered, which is not preferable.

In the present invention, when the crosslinking agent (F) is further added, the effect of the present invention is remarkably exhibited.
The cross-linking agent (F) is not particularly limited, and examples thereof include carbodiimide compounds, oxazoline compounds, aziridine compounds, hydrazine compounds, isocyanate compounds, melamine compounds, epoxy compounds, metal salts and metal complex salts. Among them, at least one compound selected from a carbodiimide compound, an oxazoline compound, an aziridine compound, and a hydrazine compound is preferably used. Further, carbodiimide compounds and hydrazine compounds are particularly preferable.

The carbodiimide compound may be any compound containing at least two carbodiimide groups, and examples thereof include "carbodilite" (manufactured by Nisshinbo).

The oxazoline compound may be any compound containing at least two oxazoline groups, and examples thereof include "Epocros" (manufactured by Nippon Shokubai Co., Ltd.). The aziridine compound may be any compound containing at least two aziridine groups, and examples thereof include "chemitite" (manufactured by Nippon Shokubai). The hydrazine compound may be any compound containing at least two hydrazine groups, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid. Examples thereof include acid dihydrazide and itaconic acid dihydrazide.

Examples of the isocyanate compound include toluylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, metaxylylene diisocyanate, 1,5-naphthalene diisocyanate,
Isocyanate compounds such as hydrogenated diphenylmethane diisocyanate, hydrogenated toluylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, tetramethyl xylene diisocyanate, etc.,
Burette polyisocyanate compounds such as "Sumijour N" (manufactured by Sumitomo Bayer Urethane Co.), isocyanurates such as "Desmodur IL, HL" (manufactured by Bayer AG), "Coronate EH" (manufactured by Nippon Urethane Co.) Examples thereof include a polyisocyanate compound having a ring, an adduct polyisocyanate compound such as "Sumijour L" (manufactured by Sumitomo Bayer Urethane Co.), and an adduct polyisocyanate compound such as "Coronate HL" (manufactured by Nippon Polyurethane Co.). Also, blocked isocyanate may be used.

Examples of the melamine compound include (hexamethoxy) methylol melamine and methoxymethylol urea. Examples of the epoxy compound include "Deconal" (manufactured by Nagase Chemical Industry Co., Ltd.) and "Denacast" (manufactured by Nagase Chemical Industry Co., Ltd.).

Examples of the metal salts and metal complex salts include ethylenediaminetetraacetic acid (EDT), which is a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium.
Examples thereof include chelate salts of A), acetic acid-ammonium complex salts, ammonium-carbonate complex salts, and the like.

Regarding the compounding amount of the crosslinking agent (F),
Although it depends on the type, it is usually preferably 0.05 to 10 parts by weight, more preferably 0.08 to 5 parts by weight, and particularly preferably 0.1 to 100 parts by weight of the solid content in the emulsion. ~ 3 parts by weight. If the blending amount is less than 0.05 parts by weight, sufficient holding power and water whitening resistance cannot be obtained, and if it exceeds 10 parts by weight, the adhesive force and tack are lowered, which is not preferable.

Further, in the present invention, if necessary, a coatability improver, a thickener, an antiseptic / antifungal agent, an anticorrosive agent, a freeze-thaw stabilizer,
A plasticizer, a high boiling point solvent, a pigment, a filler and the like can be appropriately added to the obtained emulsion, or can be added before or during the polymerization.

The thus obtained emulsion-type pressure-sensitive adhesive composition of the present invention comprises an ethylenically unsaturated monomer (A) containing a (meth) acrylic acid alkyl ester (a1) as a main component.
And an oil-soluble component consisting of a tackifier (B) and an emulsifier (C) in an aqueous medium so that the average particle diameter of the oil-soluble component is 1.0.
In the presence of a resin emulsion [II] obtained by polymerizing an emulsion [I] emulsified to have a particle size of not more than μm in the presence of a polymerization initiator (D), a (meth) acrylic acid alkyl ester is further added. Since it is formed by polymerizing the ethylenically unsaturated monomer (E) containing (e1) as a main component, there is almost no formation of aggregates at the time of polymerization, excellent leaving stability, and adhesiveness (especially adhesion to polyolefin). Properties), holding power, substrate adhesion, and water resistance (particularly water whitening resistance).

[0074]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, "%" and "parts" mean weight basis unless otherwise specified.

Example 1 [Preparation of resin emulsion [II] (first stage polymerization)] 2-
55.8 parts of ethylhexyl acrylate (a1), n-
Butyl acrylate (a1) 30 parts, methyl methacrylate (a1) 10 parts, acrylic acid (a2) 4 parts, tripropylene glycol diacrylate (a2) 0.2 parts,
And "Super ester A-125" (rosin ester-based tackifier: manufactured by Arakawa Chemical Co., Ltd.) (B) (50 parts) in a mixed solution of 190 parts of water with 1.0 part of sodium diphosphate 12 hydrate,
Emulsifier (Asahi Denka, "SE-10N") (C) 4.5
Part was added to the dissolved aqueous solution, and the mixture was stirred and mixed using a homodisper to carry out preliminary emulsification. The average particle size of the oil-soluble component of the emulsion [I ′] was 5 μm. The average particle diameter was calculated from the scattering intensity distribution using a dynamic light scattering photometer "DLS-700" (manufactured by Otsuka Electronics Co., Ltd.) (hereinafter the same). Then, this emulsified liquid [I '] was subjected to a pressure of 50 kg / cm using a high pressure homogenizer (GAULIN).
After 1Pass treatment at ² , further pressure 300kg / cm ²
3Pass treatment with an oil-soluble component having an average particle diameter of 0.15
345.5 parts of an emulsion [I] having a size of μm was obtained.

As a polymerization initiator, 1.0 part of ammonium persulfate was dissolved in 19.0 parts of water to prepare an initiator solution.

Next, 50 parts of water and 172.8 parts of the above emulsion [I] were charged into a polymerization vessel, and when the internal temperature reached 80 ° C., 25% of the above initiator solution was added. , 80
After the polymerization was carried out at 30 ° C. for 30 minutes, the remaining emulsion [I] and 25% of the initiator solution were added dropwise at 80 ° C. over 30 minutes to carry out the polymerization. After that, the polymerization was further carried out at 80 ° C. for 1 hour to obtain a resin emulsion [II] (average particle diameter 0.14 μm).
m, resin content concentration 43.9%). The resin content concentration was calculated from the residue after drying 1 g of the resin emulsion at 110 ° C. for 3 hours (the same applies hereinafter).

[Preparation of emulsion-type pressure-sensitive adhesive composition of the present invention (second-stage polymerization)] Next, 130.2 parts of 2-ethylhexyl acrylate (e1), 70.0 parts of n-butyl acrylate (e1), methyl Methacrylate (e1) 2
A mixture of 3.3 parts, 9.3 parts of acrylic acid (e2) and 0.47 part of tripropylene glycol diacrylate (e3) was added to 110 parts of water with an emulsifier (manufactured by Asahi Denka Co., Ltd., “SE
-10N ") (C) (1.6 parts) was added to the dissolved aqueous solution,
Preliminary emulsification was carried out by stirring and mixing using a homodisper to obtain 344.9 parts of emulsion [a]. Then, this emulsion [a] was added dropwise together with 33% of the initiator solution into the resin emulsion [II] obtained above at 80 ° C. over 3 hours. % Was added. After that, the polymerization was further conducted at 80 ° C. for 2 hours. After the completion of the polymerization, the mixture was cooled and the pH was adjusted to 7.5 with 5% aqueous ammonia to obtain an emulsion having a nonvolatile content of 49%, a viscosity of 1500 mPa · s and a particle diameter of 0.17 μm. The viscosity was measured using a B type viscometer under the condition of 25 ° C (the same applies hereinafter). The following evaluation was performed on the obtained emulsion.

(Coarse Particle Amount) Obtained Emulsion 100
g was filtered through a 200 mesh screen, the filter component (aggregate: coarse particles) was dried at 100 ° C. for 3 hours, and the weight of the coarse particles (mg / Em100 g) was measured.

Furthermore, to 100 parts of the obtained emulsion,
Carbodiimide-based compound (manufactured by Nisshinbo Co., Ltd., "V-04") 1.0 part as a cross-linking agent (F), Fluorine-based coating agent (Neos Co., "FT-100") as a coatability improver 0.05
Parts and a thickener (“UH-541” manufactured by Asahi Denka Co., Ltd.) were added and mixed in an appropriate amount to adjust the viscosity to 10,000 mPa · s to obtain an emulsion-type pressure-sensitive adhesive composition. The following evaluation was performed about the obtained emulsion type adhesive composition.

(Stability upon leaving) The emulsion-type pressure-sensitive adhesive composition thus obtained was allowed to stand at 40 ° C. for 6 months, and the presence or absence of thickening and sediment or separation was observed and evaluated as follows. ○ ・ ・ ・ Thickening, sedimentation or no separation × ・ ・ ・ Thickening, sedimentation or separation

Further, the obtained emulsion-type pressure-sensitive adhesive composition had a thickness of 20 μm after drying the pressure-sensitive adhesive composition.
To a release paper and dried at 100 ° C. for 5 minutes, and then a PET film base material or aluminum vapor deposition base material having a thickness of 50 μm was adhered to produce an adhesive film, and the following adhesive properties were evaluated.

(Adhesion) After peeling off the release paper from the adhesive film (PET film base material), a stainless plate (SUS304), a polyethylene plate (Japan test panel standard test plate), 20 ° C., 65% RH 180 degree peeling strength (gf / 25 mm) was measured according to the measuring method of the adhesive force of JIS Z 0237.

(Holding power) In the above adhesive film (PET film base material), after the release paper was peeled off, the area of attachment to the test plate of the stainless steel plate (SUS304) was 25 mm.
Stick it so that it becomes × 25 mm, and 80 ° C × 50% RH
Under the conditions of 1 kg, JIS Z 02
According to the measuring method of the holding power of 37, the deviation (mm) of the film after 24 hours or the dropping time (min) of the film was measured.

(Ball tack) J. Using a dow type ball tack measuring machine, under the conditions of 20 ° C. and 65% RH, a test piece 25 mm × 100 mm, an angle of 30 °, and a ball No. with the maximum diameter that stops on the test piece (paste surface). Was measured.

(Substrate Adhesion) With the above-mentioned adhesive film (aluminum vapor deposition substrate), the same measurement as the adhesive force was performed on a stainless steel plate (SUS304), and the peel strength (g / 25 mm) and the peel state Evaluated more. The evaluation criteria are as follows. [Peeling state] A ... Peeling at interface of adherend or cohesive failure B ... Peeling at interface of base material [Comprehensive evaluation] O ... / 25 mm or more. Δ: The peeling state is the base material interface peeling, and the peeling strength is 1
It was 000 g / 25 mm or more. X: The peeling state is the peeling of the base material interface, and the peeling strength is 1
It was less than 000 g / 25 mm.

(Water Whitening Resistance) The adhesive film (PET)
The release paper (film base material: 25 mm width) was peeled off, and the glass sheet was attached to a glass plate, which was immersed in warm water at 60 ° C. for 3 days, then taken out from the water, and the transmittance (%) was immediately measured.
The transmittance is "SZ-Σ80 CO" manufactured by Nippon Denshoku Industries Co., Ltd.
LOR MEASURING SYSTEM ",
A test piece (adhesive film attached to a glass plate) that was not immersed in warm water was used as a blank during measurement.

Example 2 [Preparation of Resin Emulsion [II] (First Stage Polymerization)] 2-
Ethylhexyl acrylate (a1) 30.9 parts, n-
Butyl acrylate (a1) 60 parts, methyl methacrylate (a1) 5 parts, acrylic acid (a2) 4 parts, tripropylene glycol diacrylate (a2) 0.1 part, and "super ester A-125" (rosin ester-based adhesive Giving agent: Arakawa Chemical Co., Ltd.) (B) 50 parts of a mixed solution, 190 parts of water, 1.0 part of sodium diphosphate 12-hydrate, an emulsifier (Asahi Denka Co., Ltd., "SE-10N") (C ) 4.5 parts was added to the dissolved aqueous solution, and the mixture was stirred and mixed using a homodisper to carry out preliminary emulsification. The average particle size of the oil-soluble component of the emulsion [I ′] was 5 μm. Then, this emulsion [I '] was used as a high pressure homogenizer (manufactured by GAULIN).
Using, the pressure of 50kg / cm ² after 1Pass treatment, further pressure of 300kg / cm ² 3Pass treatment,
Emulsion [I] 3 in which the average particle diameter of the oil-soluble component is 0.15 μm
45.5 parts were obtained.

Further, 1.0 part of ammonium persulfate as a polymerization initiator was dissolved in 19.0 parts of water to prepare an initiator solution.

Next, 50 parts of water and 172.8 parts of the above emulsion [I] were charged into a polymerization vessel, and when the internal temperature reached 80 ° C., 25% of the above initiator solution was added. , 80
After the polymerization was carried out at 30 ° C. for 30 minutes, the remaining emulsion [I] and 25% of the initiator solution were added dropwise at 80 ° C. over 30 minutes to carry out the polymerization. After that, the polymerization was further carried out at 80 ° C. for 1 hour to obtain a resin emulsion [II] (average particle diameter 0.14 μm).
m, resin content concentration 43.9%).

[Preparation of emulsion-type pressure-sensitive adhesive composition of the present invention (second-stage polymerization)] Next, 72.1 parts of 2-ethylhexyl acrylate (e1), 140 parts of n-butyl acrylate (e1), and methyl methacrylate ( e1) 1
A mixture of 1.7 parts, 9.3 parts of acrylic acid (e2) and 0.23 part of tripropylene glycol diacrylate (e3) was added to 110 parts of water with an emulsifier (manufactured by Asahi Denka Co., Ltd., “SE
-10N ") (C) (1.6 parts) was added to the dissolved aqueous solution,
Preliminary emulsification was carried out by stirring and mixing using a homodisper to obtain 344.9 parts of emulsion [a]. Then, this emulsion [a] was added dropwise together with 33% of the initiator solution into the resin emulsion [II] obtained above at 80 ° C. over 3 hours. % Was added. After that, the polymerization was further conducted at 80 ° C. for 2 hours. After completion of the polymerization, the mixture was cooled and the pH was adjusted to 7.5 with 5% aqueous ammonia to obtain an emulsion having a nonvolatile content of 49%, a viscosity of 1800 mPa · s and a particle diameter of 0.17 μm. The same evaluation as in Example 1 was performed on the obtained emulsion.

Further, to 100 parts of the obtained emulsion,
2 parts of an oxazoline compound (manufactured by Nippon Shokubai Co., Ltd., "Epocros K-2010E") as a cross-linking agent (F), and a fluorine-based coating agent (manufactured by Neos, "FT-10" as a coatability improving agent.
0 ") 0.05 part, thickener (" UH-54 "manufactured by Asahi Denka Co., Ltd.
1 ”) is added and mixed to obtain a viscosity of 10000 mPa · s.
To obtain an emulsion-type pressure-sensitive adhesive composition. The emulsion-type pressure-sensitive adhesive composition thus obtained was evaluated for standing stability and pressure-sensitive adhesive properties in the same manner as in Example 1.

Example 3 In Example 1, as the cross-linking agent (F), 2,2-bishydroxymethylbutanol-tris (Nippon Shokubai Co., Ltd., “Chemite PZ-33”), which is an aziridine compound, 0.3
An emulsion type pressure-sensitive adhesive composition was obtained in the same manner except that the parts were changed. The emulsion-type pressure-sensitive adhesive composition thus obtained was evaluated for standing stability and pressure-sensitive adhesive properties in the same manner as in Example 1.

Example 4 In Example 1, 55.0 parts of 2-ethylhexyl acrylate (a1) and 0.2 parts of tripropylene glycol diacrylate (a2) were added to diacetone acrylamide (a2) 1 in the first stage polymerization. Changed to 0.0 part, and 2-ethylhexyl acrylate (a1) was added to 1 part in the second stage polymerization.
28.3 parts except that 0.47 part of tripropylene glycol diacrylate (e3) was changed to 2.3 parts of diacetone acrylamide (e3), non-volatile content 49%, viscosity 1600 mPa · s, particle size 0.17μ
m emulsion was obtained. The same evaluation as in Example 1 was performed on the obtained emulsion.

Further, to 100 parts of the obtained emulsion,
0.15 parts of adipic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd.), which is a hydrazine-based compound, as a cross-linking agent (F), a fluorine-based coating agent (manufactured by Neos, "FT-10" as a coatability improver.
0 ") 0.2 part, thickener (" UH-54 "manufactured by Asahi Denka Co., Ltd.
1 ”) is added and mixed to obtain a viscosity of 10000 mPa · s.
To obtain an emulsion-type pressure-sensitive adhesive composition. The emulsion-type pressure-sensitive adhesive composition thus obtained was evaluated for standing stability and pressure-sensitive adhesive properties in the same manner as in Example 1.

Example 5 In Example 1, "Super Ester A-125"
(Rosin ester-based tackifier: Arakawa Chemical Co., Ltd.) (B)
In the same manner except that "Bencel D-125" (polymerized rosin ester-based tackifier: manufactured by Arakawa Chemical Co., Ltd.) was used, and a non-volatile content of 49%, a viscosity of 1500 mPas, and a particle diameter of 0.17 µm. Got The same evaluation as in Example 1 was performed on the obtained emulsion. Further, an emulsion-type pressure-sensitive adhesive composition was obtained from the obtained emulsion in the same manner as in Example 1, and the emulsion-type pressure-sensitive adhesive composition thus obtained was evaluated for standing stability and pressure-sensitive adhesive property in the same manner as in Example 1. went.

Example 6 In Example 1, "super ester A-125"
(Rosin ester-based tackifier: Arakawa Chemical Co., Ltd.) (B)
In place of "YS-Polystar N-125" (terpene-phenolic resin tackifier: manufactured by Yasuhara Chemical Co., Ltd.), the same procedure was performed, with a nonvolatile content of 49%, a viscosity of 1400 mPa · s, and a particle diameter of 0.17 μm. An emulsion of The same evaluation as in Example 1 was performed on the obtained emulsion. Further, an emulsion type pressure-sensitive adhesive composition was obtained from the obtained emulsion in the same manner as in Example 1,
The emulsion-type pressure-sensitive adhesive composition thus obtained was evaluated for standing stability and pressure-sensitive adhesive properties in the same manner as in Example 1.

Example 7 The same procedure as in Example 1 was carried out except that the amount of acrylic acid was reduced to half and the amount of 2-ethylhexyl acrylate was increased by the amount reduced for both the first-stage polymerization and the second-stage polymerization. An emulsion having a nonvolatile content of 49.5%, a viscosity of 800 mPa · s and a particle diameter of 0.16 μm was obtained. The same evaluation as in Example 1 was performed on the obtained emulsion. Further, an emulsion type pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that the amount of the carbodiimide compound (“V-04” manufactured by Nisshinbo Co., Ltd.) as the crosslinking agent (F) was changed to 1.5 parts. Example 1 for the emulsion-type pressure-sensitive adhesive composition
In the same manner as above, the leaving stability evaluation and the adhesive property evaluation were performed.

Example 8 In Example 1, the amount of acrylic acid was increased by 1.5 times in both the first-stage polymerization and the second-stage polymerization, and the amount increased was 2-
The same procedure was performed except that the amount of ethylhexyl acrylate was reduced, and the non-volatile content was 47.5% and the viscosity was 2000 mPa.
An emulsion having a particle size of 0.18 μm was obtained. The same evaluation as in Example 1 was performed on the obtained emulsion. Further, an emulsion type pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that the carbodiimide compound (“V-04” manufactured by Nisshinbo Co., Ltd.) as the crosslinking agent (F) was changed to 0.75 part. The emulsion type pressure-sensitive adhesive composition thus obtained was evaluated for leaving stability and pressure-sensitive adhesive properties in the same manner as in Example 1.

Example 9 In Example 4, except that the amount of diacetone acrylamide was reduced to 1/3 in both the first-stage polymerization and the second-stage polymerization, and the amount of 2-ethylhexyl acrylate was increased by the reduced amount. The same procedure is applied, with a nonvolatile content of 49% and a viscosity of 120.
An emulsion having a particle size of 0 mPa · s and a particle diameter of 0.17 μm was obtained. The same evaluation as in Example 1 was performed on the obtained emulsion. Further, an emulsion type pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that 0.2 part of adipic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd.) was used as the cross-linking agent (F). The composition was evaluated for leaving stability and adhesive properties in the same manner as in Example 1.

Example 10 The same procedure as in Example 4 was carried out except that the amount of diacetone acrylamide was doubled and the amount of 2-ethylhexyl acrylate was reduced by the increased amount in both the first-stage polymerization and the second-stage polymerization. Done, nonvolatile content 49%, viscosity 1900m
An emulsion having Pa · s and a particle diameter of 0.17 μm was obtained.
The same evaluation as in Example 1 was performed on the obtained emulsion. Further, an emulsion-type pressure-sensitive adhesive composition was obtained in the same manner as in Example 1 except that 0.1 part of adipic acid dihydrazide (manufactured by Otsuka Chemical Co., Ltd.) was used as the crosslinking agent (F), and the obtained emulsion-type pressure-sensitive adhesive was obtained. For the composition, Example 1
In the same manner as above, the leaving stability evaluation and the adhesive property evaluation were performed.

Comparative Example 1 In Example 1, the emulsion [I ′] (average particle size of oil-soluble component: 5 μm) was polymerized as it was without treatment with a high-pressure homogenizer (GAULIN) (first-stage polymerization).
The resin emulsion (average particle size 0.12 μm,
A resin content concentration of 43.9%) was obtained, and a second stage polymerization was carried out using this resin emulsion in the same manner as in Example 1 to obtain a nonvolatile content of 48.5%, a viscosity of 2000 mPa · s, and a particle size of 0.15 μm. An emulsion was obtained, and further an emulsion type pressure-sensitive adhesive composition was obtained. The obtained emulsion and emulsion-type pressure-sensitive adhesive composition were evaluated in the same manner as in Example 1.

Comparative Example 2 55.8 parts of 2-ethylhexyl acrylate (a1),
30 parts of n-butyl acrylate (a1), 10 parts of methyl methacrylate (a1), 4 parts of acrylic acid (a2), 0.2 parts of tripropylene glycol diacrylate (a2).
And 50 parts of "Super Ester A-125" (rosin ester-based tackifier: manufactured by Arakawa Chemical Co., Ltd.) (B) in 190 parts of water, sodium diphosphate 12-hydrate 1.0
Part, emulsifier ("SE-10N" manufactured by Asahi Denka Co., Ltd.) (C)
4.5 parts was added to the dissolved aqueous solution, and the mixture was stirred and mixed using a homodisper to carry out preliminary emulsification. The average particle size of the oil-soluble component of the emulsion [I ′] was 5 μm. Then, this emulsion is treated with a high pressure homogenizer (GAULIN
Using company Ltd.), was 1Pass at a pressure 50 kg / cm ^2, further 3Pass at a pressure 300 kg / cm ^2, an emulsion having an average particle diameter of the oil soluble components is 0.15 [mu] m [I] 345.5 parts Got

Further, 0.5 part of ammonium persulfate as a polymerization initiator was dissolved in 9.5 parts of water to prepare an initiator solution.

Next, 50 parts of water and 172.8 parts of the above emulsion [I] were charged in a polymerization vessel, and when the internal temperature reached 80 ° C., 50% of the above initiator solution was added. , 80
After the polymerization was carried out at 30 ° C. for 30 minutes, the remaining emulsion [I] and the initiator solution were added dropwise at 80 ° C. over 30 minutes to carry out the polymerization, and further the polymerization was carried out at 80 ° C. for 1 hour. Then, the mixture was cooled and the pH was adjusted to 7.5 with 10% aqueous ammonia, the nonvolatile content was 43%, the viscosity was 80 mPa · s, and the particle size was 0.1.
A 14 μm emulsion was obtained. Further, using the obtained emulsion, an emulsion type pressure-sensitive adhesive composition was obtained in the same manner as in Example 1. The obtained emulsion and emulsion-type pressure-sensitive adhesive composition were evaluated in the same manner as in Example 1.

Comparative Example 3 In Comparative Example 2, "Super Ester A-125" was used.
(Rosin ester-based tackifier: Arakawa Chemical Co., Ltd.) (B)
15 parts, water 97.2 parts, dibasic sodium phosphate dodecahydrate 0.3 part, emulsifier (Asahi Denka Co., Ltd., "SE-10N")
The same procedure is repeated except that (C) is changed to 3.5 parts to obtain an emulsion [I] having an oil-soluble component having an average particle size of 0.20 μm. Polymerize to
An emulsion having a nonvolatile content of 48.5%, a viscosity of 150 mPa · s and a particle diameter of 0.20 μm was obtained. Further, using the obtained emulsion, an emulsion type pressure-sensitive adhesive composition was obtained in the same manner as in Example 1. The obtained emulsion and emulsion-type pressure-sensitive adhesive composition were evaluated in the same manner as in Example 1.

Comparative Example 4 In Example 1, "Super Ester A-125"
(Rosin ester-based tackifier: Arakawa Chemical Co., Ltd.) (B)
The first-stage polymerization and the second-stage polymerization were carried out in the same manner except that was omitted, to obtain an emulsion having a non-volatile content of 43%, a viscosity of 100 mPa · s, and a particle size of 0.15 μm, and then separately emulsified “Super Ester A- "125" is added in the same amount as in Example 1 to obtain an emulsion, and a crosslinking agent (F), a coatability improver, and a thickener are added in the same manner as in Example 1 to prepare an emulsion-type adhesive composition. Got The obtained emulsion and emulsion-type pressure-sensitive adhesive composition were evaluated in the same manner as in Example 1. The evaluation results of Examples and Comparative Examples are shown in Tables 1 to 3.

[0108]

[Table 2] Adhesive force Holding force Ball tack (gf / 25mm) (mm or min) (No.) Stainless steel plate Polyethylene plate 80 ° C x 50% RH Example 1 1800 850 No deviation 6 6 2 1600 750 Deviation None 4 〃 3 1500 700 No deviation 4 〃 4 1800 800 No deviation 6 〃 5 1800 850 No deviation 5 5 〃 6 5 700 700 No deviation 4 700 〃 7 7 500 850 None 4 deviation 7 1 800 s 6 〃 10 1600 750 No deviation 5 Comparative example 1 1300 250 No deviation 6 〃 2 1800 800 200min 2 or less 〃 3 1500 500 No deviation 6 6 〃 4 1300 500 No deviation 6

[Table 3] Adhesion to base material Water resistance to whitening Peel strength Peeling condition Comprehensive evaluation (%) (gf / 25 mm) Example 1 1600 A ○ 95 〃 2 1500 A ○ 93 〃 3 1450 A ○ 95 〃 4 1650 A ○ 93 〃 5 1600 A ○ 92 〃 6 1400 A ○ 92 〃 7 1300 A ○ 90 〃 8 1650 A ○ 95 〃 9 1500 A ○ 92 〃 10 1600 A ○ 93 Comparative Example 1 1 200 A 〃 200 A △ 75 〃 3 1100 B △ 45 〃 4 700 B × 30

[0111]

The emulsion type pressure-sensitive adhesive composition of the present invention comprises an ethylenically unsaturated monomer (A) containing a (meth) acrylic acid alkyl ester (a1) as a main component and a tackifier (B). The emulsion [I] obtained by emulsifying the oil-soluble component [I] with an emulsifier (C) in an aqueous medium so that the average particle diameter of the oil-soluble component is 1.0 μm or less is used as a polymerization initiator ( In the presence of a resin emulsion [II] obtained by polymerization in the presence of D), an ethylenically unsaturated monomer (E) containing (meth) acrylic acid alkyl ester (e1) as a main component is further polymerized. As a result, almost no aggregates are formed during polymerization, leaving stability is excellent, adhesiveness (especially adhesion to polyolefin), holding power, substrate adhesion,
It has an excellent effect on water resistance (particularly water whitening resistance).

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[Procedure amendment]

[Submission date] July 1, 2002 (2002.7.1)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction content]

The tackifier (B) used in the present invention may be any one which can be dissolved or dispersed in the ethylenically unsaturated monomer (A). For example, "super ester A-"
75 "(manufactured by Arakawa Chemical Co., Ltd.)," Super Ester A-10 "
0 "(manufactured by Arakawa Chemical Co., Ltd.)," Super Ester A-12 "
5 "(Arakawa Chemical Co., Ltd.) and other rosin esters," Pencel D125 "(Arakawa Chemical Co., Ltd.)," Pencel D160 "
(Manufactured by Arakawa Chemical Industries, Ltd.), "Rikatakku PCJ" (Rika Fine Tech Co., Ltd.) polymerized rosin ester, such as, "Nikanol H
P-100 "(manufactured by Mitsubishi Gas Chemical Company)," Nikanol HP
-150 "(manufactured by Mitsubishi Gas Chemical Co., Inc.)," Nikanol H-8 "
0 "and other xylene resins," YS Polystar T-115 "
(Made by Yasuhara Chemical Co., Ltd.), "Mytec G125"
(Yasuhara Chemical Co., Ltd.) and other terpene phenolic resins, “FTR-6120” (Mitsui Petrochemical Co., Ltd.), “F
TR-6100 "(Mitsui Petrochemical Co., Ltd.) and other petroleum resins,
Other examples include coumarone indene resin, terpene resin, styrene resin, ethylene / vinyl acetate resin and the like.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Correction content]

The polymerization initiator (D) may be added in advance in the polymerization vessel, may be added immediately before the start of the polymerization, or may be additionally added during the polymerization, if necessary. Then
Further, a mixed solution may be added in advance to the ethylenically unsaturated monomer prior to emulsification (A) and the tackifier (B), but it may also be added to the emulsion after the emulsification [I]. Upon addition, polymerization
The initiator (D) was separately dissolved in a solvent and added, or dissolved.
The polymerization initiator (D) may be further emulsified and added.
Also, if necessary, it is possible to adjust the pH during the polymerization.
Therefore, a pH buffer may be used together.

Continued front page    F term (reference) 4J040 DF041 DF042 DF051 DF052                       EC22 GA03 GA05 GA06 GA07                       GA11 GA22 GA31 HC15 HC16                       HC18 HC22 HC26 JA03 JB09                       KA16 KA26 LA06 LA07 QA01

Claims (8)

[Claims] 1. An ethylenically unsaturated monomer (A) containing a (meth) acrylic acid alkyl ester (a1) as a main component.
And an oil-soluble component consisting of a tackifier (B) and an emulsifier (C) in an aqueous medium so that the average particle diameter of the oil-soluble component is 1.0.
In the presence of a resin emulsion [II] obtained by polymerizing an emulsion [I] emulsified to have a particle size of not more than μm in the presence of a polymerization initiator (D), a (meth) acrylic acid alkyl ester is further added. An emulsion-type pressure-sensitive adhesive composition, which is obtained by polymerizing an ethylenically unsaturated monomer (E) containing (e1) as a main component. 2. The emulsion-type pressure-sensitive adhesive composition according to claim 1, wherein the ethylenically unsaturated monomer (E) contains a carboxyl group-containing unsaturated monomer (e2). 3. A carboxyl group-containing unsaturated monomer (e
Content of 2) is 1-10 weight% with respect to an ethylenically unsaturated monomer (E), The emulsion type adhesive composition of Claim 2 characterized by the above-mentioned. 4. The ethylenically unsaturated monomer (E) is a carboxyl group-containing unsaturated monomer (e2) and a crosslinkable group-containing unsaturated monomer (provided that the carboxyl group-containing unsaturated monomer ( Excluding e2)] (e3) is contained, The emulsion type adhesive composition of Claim 1 characterized by the above-mentioned. 5. A carboxyl group-containing unsaturated monomer (e
The content of 2) is 1 to 10% by weight with respect to the ethylenically unsaturated monomer (E), and the crosslinkable group-containing unsaturated monomer [however, the carboxyl group-containing unsaturated monomer (e2) except for〕
Content of (e3) is 0.05-5 weight% with respect to an ethylenically unsaturated monomer (E), The emulsion type adhesive composition of Claim 4 characterized by the above-mentioned. 6. A crosslinkable group-containing unsaturated monomer (excluding carboxyl group-containing unsaturated monomer (e2)) (e3)
Is a keto group-containing unsaturated monomer, and the emulsion type pressure-sensitive adhesive composition according to claim 4 or 5, wherein 7. The emulsion-type pressure-sensitive adhesive composition according to claim 1, further comprising a crosslinking agent (F). 8. The emulsion-type pressure-sensitive adhesive according to claim 7, wherein the crosslinking agent (F) is at least one compound selected from a carbodiimide compound, an oxazoline compound, an aziridine compound, and a hydrazine compound. Agent composition.