JP5930168B2 - Tackifying resin emulsion, emulsion-type pressure-sensitive adhesive composition, and pressure-sensitive adhesive composition for film label - Google Patents

Description

  The present invention relates to a tackifying resin emulsion, an emulsion-type pressure-sensitive adhesive composition using the same, and a pressure-sensitive adhesive composition for a film label using the pressure-sensitive adhesive composition.

  In the production of tapes, sheets, labels, etc., as a pressure-sensitive adhesive composition to be applied to paper or plastic film as a base material, conventionally, a tackifying resin for imparting adhesive strength and (meth) acrylic type A solution type solution in which a base polymer such as a polymer is dissolved in an organic solvent has been common, but in recent years, an emulsion-type pressure-sensitive adhesive composition has been mainstream in consideration of the environment, safety and health, and resource saving. It is becoming.

  As an emulsion-type pressure-sensitive adhesive composition, conventionally, a mixture obtained by emulsifying and mixing the base polymer and the tackifying resin separately in the presence of various anionic emulsifiers has been used. However, there are problems in terms of water resistance, such as whitening of the adhesive film under reduced conditions of moisture and moisture, and a decrease in adhesive strength against various substrates (metals, plastics, etc.). In some cases, it is not suitable for applications requiring designability.

  As means for improving water resistance, a method using a nonionic emulsifier having an oxyalkylene group in the molecule such as polyoxyethylene distyryl phenyl ether has been proposed as an emulsifier for a tackifier resin emulsion (Patent Document 1). The emulsifiability is insufficient, and there is room for improvement in terms of water resistance.

JP-A-11-61087

  The main object of the present invention is to provide a novel tackifying resin emulsion that has excellent emulsifiability and can impart good water resistance to an emulsion-type pressure-sensitive adhesive composition.

  As a result of intensive studies, the present inventors have found that the above problem can be solved by using a predetermined polymer salt as a tackifier resin emulsion emulsifier.

That is, the present invention provides a glass transition obtained by reacting an anionic monomer (a1), a (meth) acrylic acid alkyl ester monomer (a2) and a compound (a3) represented by the following general formula (1). A polymer (A ′) having a temperature of −50 to 110 ° C. (however, a (meth) acrylamide monomer and a reactive emulsifier are excluded as monomers constituting the component (A ′)) is represented by the following general formula (2 A tackiness obtained by emulsifying the tackifier resin (B) in the presence of a polymer salt (A) neutralized with a nitrogen-containing compound (α) having a boiling point of −33.3 to 110 ° C. An emulsion-type pressure-sensitive adhesive composition containing the tackifier-resin emulsion and a base polymer emulsion; and a film label pressure-sensitive adhesive using the emulsion-type pressure-sensitive adhesive composition.

(In formula (2), X ¹ , X ² and X ³ each represent hydrogen or an alkyl group having 1 to 5 carbon atoms.)

  The tackifying resin emulsion of the present invention is excellent in emulsifying property (stability) such as a fine particle size and insoluble matter, and is well compatible with the base polymer emulsion. In addition, an emulsion-type pressure-sensitive adhesive composition using the tackifying resin emulsion is excellent in water resistance. For example, the whitening resistance (hereinafter referred to as water whitening resistance) of a pressure-sensitive adhesive film under conditions with a lot of moisture and moisture. And good adhesion to various substrates under similar conditions, such as metal substrates and plastic substrates, particularly polyolefin substrates which are considered to be difficult to adhere (hereinafter, sometimes referred to as water-resistant adhesion). It is.

  Therefore, the tackifying resin emulsion of the present invention is important for various pressure-sensitive adhesive compositions, for example, pressure-sensitive adhesives for building materials that require water resistance and adhesion to polyolefin substrates, pressure-sensitive adhesives for automobile interior parts, and design properties. It is suitable for an adhesive for film labels and the like.

The tackifying resin emulsion of the present invention comprises an anionic monomer (a1) (hereinafter referred to as component (a1)), a (meth) acrylic acid alkyl ester monomer (a2) (hereinafter referred to as component (a2)). , A glass obtained by reacting a compound (a3) represented by the predetermined general formula (1) (hereinafter referred to as component (a3)) and, if necessary, styrenes (a4) (hereinafter referred to as component (a4)) Polymer (A ′) having a transition temperature of −50 to 110 ° C. (hereinafter referred to as (A ′) component) (However, (meth) acrylamide monomer and reactivity as the monomer constituting (A ′) component) boiling represented excluding emulsifier.) at a predetermined equation (2) -33. Tackifying resin (B) in the presence of polymer salt (A) (hereinafter referred to as (A) component) neutralized with nitrogen-containing compound (α) (hereinafter referred to as (α) component) at 3 to 110 ° C. ) (Hereinafter referred to as component (B)).

  As the component (a1), various known compounds can be used without particular limitation. For example, α, β-unsaturated monocarboxylic acid such as (meth) acrylic acid, crotonic acid, and isocrotonic acid, fumaric acid, (anhydrous ) Α, β-unsaturated dicarboxylic acid such as maleic acid, itaconic acid, muconic acid, α, β-unsaturated dicarboxylic acid obtained by reacting the α, β-unsaturated dicarboxylic acid with a monoalcohol having 1 to 18 carbon atoms in the alkyl group. (beta) -unsaturated dicarboxylic acid half ester etc. are mentioned, Among these, (meth) acrylic acid is preferable mainly from the point of emulsifiability and water resistance. In addition, although the usage-amount of the (a1) component in (A ') component is not specifically limited, Especially it is about 18 to 40 weight% from an emulsifiable viewpoint, Preferably it is 19 to 38 weight%.

  As the component (a2), various known compounds can be used without particular limitation. For example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, normal butyl (meth) acrylate, (Meth) acrylic acid lauryl, (meth) acrylic acid stearyl, (meth) acrylic acid isobutyl, (meth) acrylic acid tertiary butyl, (meth) acrylic acid-2-ethylhexyl, (meth) acrylic acid cyclohexyl, (meth) Examples include cyclopentyl acrylate and isobornyl (meth) acrylate. Among these, the number of carbon atoms of the alkyl group is usually about 1 to 8, preferably from the viewpoints of emulsifying properties, compatibility with the base polymer, water resistance, etc. 1-4. In addition, although the usage-amount of (a2) component in (A ') component is not specifically limited, it is about 45-79.9 weight% normally from points, such as emulsification property and water resistance especially, Preferably it is 47-73 weight%. .

  The component (a3) is a compound represented by the following general formula (1), and emulsification and water resistance are particularly improved by using the component as an essential component. The amount of the component (a3) used in the component (A ′) is not particularly limited, but is usually about 0.1 to 10% by weight, preferably 4 to 10% by weight from the viewpoint of emulsification and water resistance.

  Examples of the component (a4) include styrene, α-methyl styrene, t-butyl styrene, dimethyl styrene and the like, and styrene is preferred mainly from the viewpoint of emulsification and water resistance. In addition, the usage-amount of (a4) component in (A ') component is not specifically limited, Usually, it is about 0-30 weight%, However, when water resistance is considered especially, it is preferable that it is 4-20 weight%. .

  In addition, (meth) acrylamide monomers such as acrylamide, methacrylamide, N, N′-dimethylacrylamide, N, N′-dimethylmethacrylamide, and so-called reactive emulsifiers are used as monomers constituting the component (A ′). When is used, the water resistance tends to be insufficient. Here, the “reactive emulsifier” refers to an oxyalkylene group having about 5 to 50 (preferably 10 to 30) repeating units in one molecule, a hydrophilic functional group such as an anionic functional group or a hydroxyl group, At least one hydrocarbon group having about 5 to 20 carbon atoms (which may be linear, branched or cyclic) and a radically polymerizable functional group such as a (meth) acryloyl group or a propenyl group. Emulsifier (see, for example, JP-A-9-324394).

  Examples of the method of reacting the components (a1) to (a3) (and the component (a4) as necessary) include various known polymerization methods such as solution polymerization and emulsion polymerization. Examples of the solvent used for the solution polymerization include benzene, toluene, xylene, hexane, cyclohexane, methanol, ethanol, isopropyl alcohol, ethyl acetate, acetone, methyl isobutyl ketone, dioxane, dimethylformamide, and dimethyl sulfoxide. In the case of emulsion polymerization, various known non-reactive low molecular weight emulsifiers include, for example, dialkyl sulfosuccinic acid ester salts, alkane sulfonic acid salts, α-olefin sulfonic acid salts, polyoxyethylene alkyl ether sulfosuccinic acid ester salts, Anionic emulsifiers such as oxyethylene styryl phenyl ether sulfosuccinate ester salt, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl ether sulfate ester salt, and polyoxyethylene alkyl phenyl ether sulfate ester salt, polyoxyethylene alkyl ether Nonionic emulsifiers such as oxyethylene styryl phenyl ether and polyoxyethylene sorbitan fatty acid ester can be appropriately used. The amount of the low molecular weight emulsifier used is not particularly limited, but it is usually 5% by weight or less, preferably 0.1 to 2% by weight based on the total weight of the components (a1) to (a4), particularly from the viewpoint of water resistance. %.

  In the polymerization reaction, benzoyl peroxide, tert-butyl peroxide, lauroyl peroxide, cumyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, azobisisobutyronitrile, 2,2- Azobis- (2,4-dimethylvaleronitrile), hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, 2,2′-azobis- (2-amidinopropan) -hydrochloride, redox initiator (peroxide Persulfates such as hydrogen oxide-ferrous chloride, ammonium persulfate-acidic sodium sulfite, etc.) and initiators such as peroxides, azo compounds, redoxes, etc. are added to the total weight of components (a1) to (a4). On the other hand, it can be used in the range of usually about 0.1 to 10% by weight.

  In the polymerization reaction, methanethiol, ethanethiol, propanethiol, butanethiol, octanethiol, dodecanethiol, benzenethiol, toluenethiol, α-naphthalenethiol, β-naphthalenethiol, mercaptomethanol, mercaptoethanol, mercapto Chain transfer agents such as propanol and mercaptobutanol can be used usually in the range of about 0.1 to 5% by weight based on the total weight of the components (a1) to (a4).

  The component (A ′) has a glass transition temperature of usually about −50 to 110 ° C., preferably 0 to 90 ° C., more preferably 40 to 80 ° C., particularly from the viewpoints of emulsifying properties and water resistance.

  Other physical properties of the component (A ′) are not particularly limited, but particularly from the viewpoint of emulsifying properties and water resistance, for example, the acid value is usually about 100 to 400 mgKOH / g, preferably 110 to 250 mgKOH / g. In addition, the said acid value can be calculated | required by the neutralization titration method defined by JIS-K2501. Also, the weight average molecular weight is not particularly limited, but it is usually about 5000 to 30000, preferably 8000 to 28000, from the viewpoint of emulsifying properties and water resistance.

  By neutralizing the component (A ′) with the component (α) represented by the following general formula (2), the component (A) which is a polymer emulsifier is obtained.

(In formula (2), X ¹ , X ² and X ³ each represent hydrogen or an alkyl group having 1 to 5 carbon atoms.)

The component (α) has a boiling point of −33 . Since it is 3 to 110 ° C., the component (A ′) is easily separated from the pressure-sensitive adhesive film into the atmosphere in combination with the glass transition temperature, and as a result, the hydrophobicity of the film increases, resulting in increased water resistance. It is thought to improve. From this viewpoint, the boiling point of the component (α) is preferably −33 . About 3 to 90 ° C., more preferably −33 . 3 to 20 ° C. Specific examples of the component (α) include, for example, ammonia; methylamine, ethylamine, propylamine, isopropylamine, butylamine, s-butylamine, t-butylamine, isobutylamine, pentylamine, t-pentylamine, isopentylamine and the like. Monoamines; diamines such as dimethylamine, diethylamine, dipropylamine and diisopropylamine; and triamines such as trimethylamine and triethylamine. Among these, ammonia is particularly preferred from the viewpoint of water resistance. The amount of component (α) used is not particularly limited, but is usually in the range of about 50 to 150 mol% with respect to the total moles of carboxyl groups of component (A ′). In place of the component (α), metal hydroxides such as sodium hydroxide and potassium hydroxide, alkanolamines such as diethanolamine, and amines represented by the general formula (1) but having no boiling point When an amine (such as dibutylamine) or an amine not represented by the general formula (1) (a diamine such as ethylenediamine) is used, the water resistance tends to be insufficient.

As described above, in the present invention, the glass transition temperature of the component (A ′) is specified, and the water resistance of the pressure-sensitive adhesive film is improved by using the volatile component (α). From such a viewpoint, the difference (AV _a −AV _b ) between the acid value AV _a of the dry film of component (A ′) itself and the acid value AV _b of the dry film of component (A) itself is usually 0 to 1. About 0.0 mgKOH / g, preferably 0 to 0.2 mgKOH / g. Each dry film can be obtained by applying a solution of the component (A) or the component (A ′) to, for example, a glass plate and then drying.

  As the component (B), various known tackifying resins can be used. The physical properties thereof are not particularly limited, but those having a softening point of about 70 to 180 ° C., particularly 100 to 180 ° C. are preferred mainly from the viewpoint of water whitening resistance and water-resistant adhesive strength.

  Specific examples of the component (B) include various known tackifying resins such as rosins, rosin derivatives, petroleum resins, phenol resins, terpene resins, and ketone resins.

  Examples of the rosins include raw rosins such as gum rosin, tall oil rosin, and wood rosin; stabilized rosins obtained by disproportionating or hydrogenating raw rosins; polymerized rosins obtained from raw rosins; raw rosins and stable rosins And acid-modified rosin obtained from the above-mentioned component (a1) (acrylic acid, methacrylic acid, (anhydrous) maleic acid, fumaric acid, etc.).

  Examples of the rosin derivative include rosin esters obtained by esterifying the rosins and polyhydric alcohols, rosin-phenol resins obtained by reacting the rosins and phenols, the rosins, phenols, and Examples thereof include rosin ester-phenol resin obtained by reacting the polyhydric alcohol. The polyhydric alcohol includes dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol and neopentyl glycol, trihydric alcohols such as glycerin, trimethylolethane and trimethylolpropane, and tetravalents such as pentaerythritol and diglycerin. Examples include alcohols and hexavalent alcohols such as dipentaerythritol. Among these, a polymerized rosin ester is particularly preferable from the viewpoint of water-resistant adhesion to a polyolefin substrate.

  Examples of the petroleum resin include C5 petroleum resins obtained from pentene, pentadiene, isoprene, and C9 petroleum resins obtained from indene, methylindene, vinyltoluene, styrene, α-methylstyrene, β-methylstyrene, and the like. C5-C9 copolymer petroleum resins obtained from monomers, DCPD petroleum resins obtained from cyclopentadiene, dicyclopentadiene (DCPD), petroleum resins in which polar groups such as hydroxyl groups are bonded to these petroleum resins, hydrogen of these petroleum resins And the like.

  As the phenol resin, specifically, a resol phenol resin obtained by reacting various known phenols with formaldehyde in the presence of an alkali catalyst, a novolac phenol resin obtained by reacting in the presence of an acid catalyst, Examples thereof include a rosin-modified phenol resin obtained by reacting the resol phenol resin or novolac phenol resin with the raw material rosin. Examples of the phenols include phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcin and the like.

  Examples of the terpene resin include α-pinene resin, β-pinene resin, aromatic modified terpene resins obtained by copolymerizing terpenes such as α-pinene and β-pinene, and aromatic monomers such as styrene and phenol. And hydrides of the aromatic modified terpene resins.

  Examples of the ketone resin include condensates of ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexanone, and methylcyclohexanone with formaldehyde.

  The tackifying resin emulsion of the present invention is obtained by emulsifying the component (B) in the presence of the component (A) which is a polymer emulsifier. The emulsification method is not particularly limited, and various known methods can be employed. For example, the following methods are mentioned.

  [1] Dissolve component (B) in an organic solvent such as toluene, xylene, cyclohexane, methylcyclohexane, pentane, etc., add soft water, component (A) and, if necessary, the low molecular weight emulsifier, A method of emulsifying and removing an organic solvent under reduced pressure.

  [2] Mix component (B) with a small amount of organic solvent, component (A) and the low molecular weight emulsifier as necessary, gradually add hot water, phase inversion emulsify to make an emulsion, Accordingly, the solvent is removed under reduced pressure.

  [3] Under pressure or normal pressure, the component (A) and, if necessary, the low molecular weight emulsifier are mixed at a temperature equal to or higher than the softening point of the component (B), and hot water is gradually added, followed by phase inversion. Emulsification method.

  Although the usage-amount of (A) component and (B) component is not specifically limited, the usage-amount of (A) component with respect to 100 weight part (solid content conversion) of (B) component mainly from the point of emulsification property or water resistance. Usually, it is about 2 to 10 parts by weight (in terms of solid content), preferably 2 to 6 parts by weight.

  The physical properties of the tackifier resin emulsion thus obtained are not particularly limited. For example, the average particle size is usually about 0.1 to 1.5 μm, the pH is about 2 to 10, and the nonvolatile content is about 20 to 70% by weight.

  The emulsion-type pressure-sensitive adhesive composition of the present invention contains the tackifying resin emulsion of the present invention and various known base polymer emulsions. The type of the base polymer emulsion is not particularly limited, and examples thereof include (meth) acrylic polymer emulsions, rubber latexes, and synthetic resin emulsions (excluding the (meth) acrylic polymer emulsions). In addition, a (meth) acrylic polymer emulsion is preferred from the viewpoint of the adhesive strength of the adhesive film to various adherends. In addition, the amount of the tackifying resin emulsion used in the pressure-sensitive adhesive composition is not particularly limited, but particularly 100 parts by weight of the base polymer emulsion (in terms of solid content) from the viewpoint of water resistance and adhesive strength to various adherends. Usually about 2 to 40 parts by weight (in terms of solid content).

  Specific examples of the monomer used for producing the (meth) acrylic polymer emulsion include the same components as the component (a1) and the component (a2). ) Component, (a4) component, and other monomers can also be used. Specifically, (meth) acrylic acid is preferable as the component (a1), -2-ethylhexyl acrylate or butyl acrylate is preferable as the component (a2), and styrene is preferable as the component (a4). Moreover, the manufacturing method of the said emulsion is not specifically limited, either batch polymerization, sequential polymerization, seed polymerization, emulsion polymerization, etc. are employable. In this case, the non-reactive low molecular weight emulsifier described above can be used.

  Examples of the rubber latex include natural rubber latex, styrene-butadiene copolymer latex, and chloroprene latex.

  Examples of the synthetic resin emulsion include synthetic resin emulsions such as vinyl acetate emulsion, ethylene-vinyl acetate copolymer emulsion, and urethane emulsion.

  Examples of the substrate on which the pressure-sensitive adhesive composition of the present invention is applied include plastic substrates such as polyolefin (polyethylene, polypropylene, etc.), polyester, polycarbonate, vinyl chloride, and various label papers. This is preferable. Moreover, as a base material which is a to-be-adhered body, the said plastic base material and metals, such as aluminum and stainless steel, are mentioned, The adhesive composition of this invention is especially excellent in water-resistant adhesive force with polyolefin.

  The pressure-sensitive adhesive composition of the present invention is, for example, a product that is particularly required to have water resistance and adhesive strength to a polyolefin substrate, for example, a building material pressure-sensitive adhesive or a car interior member pressure-sensitive adhesive, and also has an emphasis on design. Suitable as an adhesive for film labels. Moreover, when using as the said adhesive composition for film labels, as an above-mentioned to-be-adhered body, a polyolefin base material is preferable.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail through an Example and a comparative example, the technical scope of this invention is not necessarily limited to these. In each example, parts and% are based on weight unless otherwise specified.

<Manufacture of (A) component>
Production Example 1
A five-necked flask equipped with a nitrogen gas inlet tube, a thermometer, a reflux condenser, a dropping funnel and a stirrer was added to a non-reactive anionic emulsifier (trade name “Hitenol NF-08”, Daiichi Kogyo Seiyaku Co. )) 1.0 part and 268 parts of water were charged, and the inside of the system was made into a uniform aqueous solution. Subsequently, the temperature was raised to 85 ° C. under a nitrogen stream, a solution comprising 20 parts of methacrylic acid, 80 parts of normal butyl methacrylate and 5 parts of the compound represented by the general formula (1), 4 parts of ammonium persulfate and 80 of water. The aqueous solution consisting of parts was gradually dropped from separate dropping funnels and reacted for 3 hours. Furthermore, the aqueous solution which consists of 1 part of ammonium persulfate and 10 parts of water was dripped, and it was made to react for 2 hours, and the aqueous solution of polymer (A'-1) was obtained. The acid value (AVa) of the component (A′-1) was 124.3 mgKOH / g, the glass transition temperature was 47 ° C., and the weight average molecular weight was 11,000.

  Next, ammonia water (25%, 15.8 parts) in an amount such that the neutralization rate of the carboxyl group of the component (A′-1) is 100 mol% is added to the flask and stirred well. To obtain an aqueous solution of polymer salt (A-1) having a nonvolatile content of 23%.

<Formation of polymer emulsifier film>
An aqueous solution of component (A′-1) was added to bar coater No. 20 was applied to a glass plate and dried at 110 ° C. for 2 hours to obtain a film. Moreover, the film-like thing was similarly obtained about the aqueous solution of (A-1) component.

<Measurement of glass transition temperature (Tg)>
Using a commercially available thermal stress strain measuring device (TMA: Seiko Instruments Inc., product name “TMA-120”), a load of 5 g was applied to the film-like product of component (A′-1) via a needle probe. In addition, the temperature inside the apparatus was increased from −100 ° C. at a constant rate (10 ° C./min), and the glass transition temperature (° C.) was determined from the obtained transition curve. The results are shown in Table 1.

<Measurement of acid value>
Using each film-like product of component (A′-1) and component (A-1), JIS K
Acid values (AVa, AVb) were measured by a neutralization titration method based on 2501, respectively. The results are shown in Table 1.

<Measurement of weight average molecular weight (Mw)>
About each aqueous solution of (A'-1) component and (A-1) component, gel permeation chromatography (the Tosoh Co., Ltd. make, brand name "HLC-8320", column: Tosoh Corporation make, brand name " By using “TSKgel GMPWXL” and “TSKgel G2500PWXL”), the weight average molecular weights as polyethylene oxide equivalent values were determined. The results are shown in Table 1.

Production Examples 2 to 12, Comparative Production Examples 1 to 15
An aqueous solution of each polymer salt was obtained in the same manner as in Production Example 1 except that the types and parts of raw materials shown in Table 1 were used. Moreover, each ((alpha)) component was used by the number of parts used as the neutralization rate same as the neutralization rate of the carboxyl group in manufacture example 1. Moreover, the glass transition temperature, the acid value, and the weight average molecular weight were determined by the same method as described above. The results are shown in Table 1.

MAA: methacrylic acid IA: itaconic acid BMA: normal butyl acrylate MMA: methyl methacrylate SMA: stearyl methacrylate St: styrene MST: α-methylstyrene AM: acrylamide RN: polyoxyethylene phenyl ether reactive emulsifier (trade name) "AQUALON RN-10" (Daiichi Kogyo Seiyaku Co., Ltd.)
MET: 2-mercaptoethanol NH ₃ : 25% ammonia water (boiling point: about −33.3 ° C.)
TEA: Triethylamine (boiling point about 89.7 ° C.)
EEA: Diethylamine (boiling point about 55.5 ° C.)
DEA: Diethanolamine (boiling point about 217 ° C)
DBA: Dibutylamine (boiling point: about 159 ° C.)
EDA: ethylenediamine (boiling point: about 117 ° C.)
Na: 48% aqueous sodium hydroxide solution K: 48% aqueous potassium hydroxide solution

<Manufacture of tackifying resin emulsion>
Example 1
100 parts of commercially available polymerized rosin-pentaerythritol ester (trade name “Pencel D-160”, manufactured by Arakawa Chemical Industries, Ltd., softening point 160 ° C.) was dissolved in 60 parts of toluene at 100 ° C. As the emulsifier, 3 parts of the component (A-1) in terms of solid content and 160 parts of water were added, and the mixture was stirred at 75 ° C. for about 1 hour and pre-emulsified. Subsequently, the obtained preliminary emulsion was high-pressure emulsified with a high-pressure emulsifier (mantongaurin) under a pressure of 30 MPa. Next, 200 parts of the obtained emulsion was charged in a vacuum distillation apparatus and distilled under reduced pressure for 8 hours under conditions of 50 ° C. and 13.3 kPa, and an emulsion of a tackifier resin having a nonvolatile content of 50% by weight. Got.

Examples 2-12
A tackifier resin emulsion (both non-volatile content is 50% by weight) is the same as in Example 1 except that each of the solutions of the components (A-1) to (A-12) is used as the polymer emulsifier. Obtained.

Example 13
Emulsion of tackifier resin in the same manner as in Example 1 except that a commercially available rosin-phenol resin (trade name “Tamanol 803L”, manufactured by Arakawa Chemical Industries, Ltd., softening point 150 ° C.) was used as the tackifier resin. (The nonvolatile content was 50% by weight).

Example 14
A tackifier was obtained in the same manner as in Example 1 except that a commercially available rosin-pentaerythritol ester (trade name “Pencel GA-100”, manufactured by Arakawa Chemical Industries, Ltd., softening point 100 ° C.) was used as the tackifier resin. A resin emulsion (non-volatile content: 50% by weight) was obtained.

Example 15
In the same manner as in Example 1, except that a commercially available petroleum resin (trade name “Nisseki Neopolymer L-90”, manufactured by JX Nippon Oil & Energy Corporation, softening point 95 ° C.) was used as the tackifying resin. An emulsion of an imparting agent resin (non-volatile content: 50% by weight) was obtained.

Comparative Examples 1-15
A tackifier resin emulsion (50% by weight of the non-volatile content) was obtained in the same manner as in Example 1 except that the solutions of the components (A) to (SO) were used as the polymer emulsifier.

Comparative Example 16
In Example 1, in place of the component (A-1), except that 5 parts of polyoxyethylene styrenated phenyl ether (trade name “Neugen EA-167” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was used, An emulsion of a tackifier resin having a nonvolatile content of 50% was obtained.

<Emulsification evaluation>

  The particle diameter of each tackifying resin emulsion of Examples and Comparative Examples was measured using a laser diffraction particle size measuring device (manufactured by Shimadzu Corporation, trade name “SALD-2000”), with a refractive index of 1.70-0.20i. The absorbance was measured under the condition of 0.06. The smaller the value, the better the storage stability.

  Moreover, the tackifying resin emulsion obtained in Example 1 was filtered through a 200-mesh wire mesh, and the weight% of the obtained residue with respect to the resin to be emulsified (polymerized rosin ester) was weighed. It means that emulsifiability is so good that a numerical value is small.

<Manufacture of base polymer emulsion>
In a five-necked flask similar to that in Example 1, 86.80 parts of water and an anionic emulsifier (polyoxyethylene styrenated phenyl ether ammonium sulfate salt, trade name “Hitenol NF-08”, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) ) 0.92 part was charged and the temperature was raised to 70 ° C. to obtain a solution. Next, a solution comprising 90.20 parts of butyl acrylate, 2.80 parts of acrylic acid, and an aqueous solution comprising 0.48 parts of potassium persulfate, 0.22 parts of sodium bicarbonate and 17.66 parts of water were respectively added from separate dropping funnels. It was added dropwise over time. After completion of dropping, a radical polymerization reaction was carried out at 70 ° C. for 1 hour. The resulting emulsion was then cooled to room temperature and filtered using a 100 mesh wire mesh to obtain an acrylic polymer emulsion having a solid content of 45.7%.

<Manufacture of emulsion type pressure-sensitive adhesive composition>
80 parts of the acrylic polymer emulsion and 20 parts of the tackifying resin emulsion of Example 1 were mixed well to obtain a pressure-sensitive adhesive composition. The pressure-sensitive adhesive compositions were similarly obtained for the tackifying resin emulsions of Examples 2 to 8 and Comparative Examples 1 to 10.

  Moreover, what used the said acrylic polymer emulsion as an adhesive composition as it was was made into the reference example.

<Evaluation of water resistance>
After the pressure-sensitive adhesive composition according to Example 1 was applied to a PET film having a thickness of 38 μm, it was dried in a circulating dryer at 110 ° C. for 5 minutes to obtain a test film provided with a pressure-sensitive adhesive film having a thickness of 70 μm. The film was then subjected to the following test. It evaluated similarly about each adhesive composition of Examples 2-15, Comparative Examples 1-16, and a reference example.

(1) Water-resistant adhesive strength Each test film was cut to a width of 25 mm and bonded to an adherend (stainless steel plate (SS) and polyethylene plate (PE)) by reciprocating a 2 kg roller and immersed in water at 23 ° C. for 72 hours. did. After taking out the laminate from the water, a 180-degree peel test was immediately performed under the conditions of a tensile speed of 300 mm / min and a measurement temperature of 23 ° C., and the adhesive strength (kg / 25 mm) was measured.

(2) Water whitening resistance Each test film was cut into an appropriate size and immersed in water at 23 ° C. for 72 hours, and then the degree of whitening of the adhesive film was visually evaluated according to the following criteria.
3: No change (transparent)
2: Slightly cloudy 1: Strongly cloudy

Claims (15)

The glass transition temperature obtained by reacting the anionic monomer (a1), the (meth) acrylic acid alkyl ester monomer (a2) and the compound (a3) represented by the following general formula (1) is -50 to 110. The boiling point represented by the following general formula (2): a polymer (A ′) at 0 ° C. (excluding (meth) acrylamide monomers and reactive emulsifiers as monomers constituting the component (A ′)) A tackifier resin emulsion obtained by emulsifying the tackifier resin (B) in the presence of a polymer salt (A) neutralized with a nitrogen-containing compound (α) at 33.3 to 110 ° C.
(In formula (2), X ¹ , X ² and X ³ each represent hydrogen or an alkyl group having 1 to 5 carbon atoms.) The tackifier resin emulsion according to claim 1, wherein the polymer (A ') further contains styrenes (a4) as a reaction component. The tackifying resin emulsion according to claim 1 or 2, wherein the component (a1) is (meth) acrylic acid. The tackifier resin emulsion according to claim 1, wherein the alkyl group of component (a2) has 1 to 8 carbon atoms. (A4) The tackifying resin emulsion according to any one of claims 1 to 4, wherein the component is styrene. The amount of components (a1) to (a4) used is 18 to 40% by weight, 45 to 79.9% by weight, 0.1 to 10% by weight, and 0 to 30% by weight, respectively. Any tackifying resin emulsion. The tackifier resin emulsion according to any one of claims 1 to 6, wherein the acid value of the component (A ') is from 100 to 400 mgKOH / g. The tackifying resin emulsion according to any one of claims 1 to 7, wherein the component (A ') has a weight average molecular weight of 5,000 to 30,000. The softening point of (B) component is 120-180 degreeC, The tackifying resin emulsion in any one of Claims 1-8. (B) The tackifying resin emulsion according to any one of claims 1 to 9, wherein the component is a polymerized rosin ester. The tackifying resin emulsion according to any one of claims 1 to 10, wherein the amount of the component (A) used is 2 to 10 parts by weight (in terms of solid content) relative to 100 parts by weight (in terms of solid content) of the component (B). An emulsion-type pressure-sensitive adhesive composition containing the tackifier resin emulsion according to claim 1 and a base polymer emulsion. The emulsion-type pressure-sensitive adhesive composition according to claim 12, wherein the base polymer emulsion is a (meth) acrylic copolymer emulsion. A pressure-sensitive adhesive composition for a film label using the emulsion-type pressure-sensitive adhesive composition according to claim 12 or 13. The pressure-sensitive adhesive composition for a film label according to claim 14, wherein the adherend is a polyolefin substrate.