JP2003238924A - Delayed tack type sticking agent composition and sticking label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the delayed tack type sticking agent composition being able to heat and dry at a comparatively high temperature on manufacturing a heat sensitive sticking label by applying it on a substrate, also being excellent in anti-blocking property on storing and able to exhibit the sticking property at a temperature not higher than a heat deformation temperature of the substrate to be applied, and to provide the sticking label made by using the composition. <P>SOLUTION: A first composition is a water dispersion type delayed tack type sticking agent composition and comprises a thermoplastic resin, a tackifiering resin and a solid plasticizer, and the thermoplastic resin is characterized by containing a core-shell type polymer. A second constitution is the delayed tack type sticking label being characterized by forming a layer of the delayed tack type sticking agent composition on the substrate for the label. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat-sensitive delayed tack type adhesive which is non-adhesive at room temperature but develops adhesiveness by heating, and after the adhesiveness develops, the adhesiveness continues even if the heating source is removed. The present invention relates to an agent composition and a heat-sensitive adhesive label.

[0002]

2. Description of the Related Art Conventional heat-sensitive delayed tack type adhesives include thermoplastic resins and tackifying resins as described in "Adhesion Handbook" (12th Edition, 1980, published by Kobunshi Shuppankai). And a solid plasticizer as a basic skeleton. The thermoplastic resin is the basis of the pressure-sensitive adhesive and is disclosed in JP-A 2000-
As described in Japanese Patent No. 53874, a thermoplastic resin that does not have tackiness at room temperature having a glass transition temperature of about 0 to 30 ° C. is usually used. Further, the solid plasticizer is solid at room temperature and does not impart plasticity to the resin, and melts by heating to melt into the resin to swell or soften the resin, thereby sticking to the non-adhesive pressure-sensitive adhesive composition at room temperature. Acts to develop sex. As the solid plasticizer, there is disclosed in JP-A-61-9.
For example, dicyclohexyl phthalate is well known, as described in JP-A-479, JP-A-7-278521, JP-A-8-333565.

Recently, the delayed tack type pressure-sensitive adhesive label as described above is often manufactured by applying an aqueous dispersion type heat-sensitive pressure-sensitive adhesive to the back surface of a substrate and then performing a heating step for drying. . In that case, the heating temperature is set such that the coating surface temperature is 45 ° C. or less so that the pressure-sensitive adhesive composition containing the solid plasticizer such as dicyclohexyl phthalate does not melt and develop the tackiness in the step of forming the pressure-sensitive adhesive layer. It is required to be low temperature. However, heating at such a low temperature requires a long time for the heating and drying process, and thus there is a problem in that the productivity of the delayed tack adhesive label is reduced. In addition, since the release tack type adhesive label does not use release paper, if it is stored for a long time in a stacked state, for example, under high temperature in summer, plasticization of an adhesive composition containing a solid plasticizer such as dicyclohexyl phthalate may occur. Gradually, so-called blocking occurs in which the labels adhere to each other. Therefore, there is a problem that a cold storage facility for preventing such blocking of the label is required.

On the other hand, the temperature and time for developing the adhesiveness by heating the coated product are low from the viewpoint of energy saving, and it is desirable that the temperature and time are short. Further, there is an upper limit of the heating temperature in order to prevent the heat deformation deterioration of the base material of the coating material. For example, in the case of plastic films such as polypropylene and polyethylene phthalate used for food packaging labels, 90 to 13
Deformation begins at 0 ° C. or higher, so it is necessary to develop tackiness at that temperature or lower.

[0005]

The object of the present invention is to enable heat-drying at a higher temperature when coating a base material to produce a heat-sensitive adhesive label, and at the same time, to improve storage resistance during storage. It is an object of the present invention to provide a delayed tack type pressure-sensitive adhesive composition which is excellent in blocking property and can exhibit pressure-sensitive adhesiveness at a temperature not higher than the heat distortion temperature of a coating substrate, and a pressure-sensitive adhesive label using the same.

[0006]

The inventors of the present invention have been able to achieve the object of the present invention by adopting the following constitutions as a result of various researches for solving the above-mentioned problems. And completed the present invention.

That is, the present invention is an aqueous dispersion type delayed tack adhesive composition comprising a thermoplastic resin, a tackifying resin and a solid plasticizer, which contains a core-shell type polymer as the thermoplastic resin. There is provided a delayed tack type pressure-sensitive adhesive composition. Further, the present invention provides a delayed tack type adhesive label characterized by comprising the above-mentioned aqueous dispersion type delayed tack type pressure sensitive adhesive composition layer on a label substrate.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The thermoplastic resin, tackifying resin and solid plasticizer, which are the constituent features of the present invention, will be described in detail below.

The core-shell type polymer contained as the thermoplastic resin used in the delayed tack type pressure-sensitive adhesive composition of the present invention has a different polymer composition between the core portion (core portion B) and the shell side (shell portion A) of the particles. It means a resin consisting of particles. In terms of manufacturing methods, for example, an emulsion polymer obtained by emulsion-polymerizing a more hydrophobic monomer in the presence of a hydrophilic shell component resin can be mentioned.

The hydrophilic shell part (A) which constitutes the core-shell type polymer is, for example, an unsaturated monomer (a) having a carboxyl group, a hydrophobic monomer (b) and other monomers (c). ) Can be obtained by copolymerization.

Examples of the unsaturated monomer (a) having a carboxyl group include acrylic acid (105 ° C.), methacrylic acid (130 ° C.) and itaconic acid (160 ° C.). The value in parentheses is the glass transition temperature of the homopolymer.

In the present specification, the "glass transition temperature" (hereinafter referred to as "Tg") of the polymer means a value obtained from the following calculation formula. In addition, only Tg used in this calculation formula is represented by an absolute temperature (K), and Tg used in other parts of the specification is represented by a temperature in Celsius (° C.).

1 / Tg = {W (a) / Tg (a)} + {W (b) / Tg (b)} + ... In the above formula; Tg = Tg (K) W (a of the polymer ) = Mass fraction W (b) of structural unit composed of monomer (a) in polymer = mass fraction Tg (a) of structural unit composed of monomer (b) in polymer = monomer ( Tg (K) of homopolymer of a) Tg (b) = Tg (K) of homopolymer of monomer (b)

The content of the unsaturated monomer (a) having a carboxyl group in the resin constituting the shell portion (A) of the core-shell type polymer as the thermoplastic resin used in the present invention is 3 to 60% by mass. Are preferably used to occupy That is, in order to sufficiently solubilize the obtained resin in water and maintain miscibility with the acrylic resin constituting the core (B) component, 3% by mass or more is preferable, and at the same time, the water resistance of the core-shell type polymer is high. 60 mass% or less is preferable in order to maintain the property. More preferably, it is in the range of 5 to 50 mass%.

As the hydrophobic monomer (b), for example, methyl methacrylate (105 ° C), ethyl acrylate (-22 ° C), butyl acrylate (-54 ° C), 2
-Ethylhexyl acrylate (-85 ° C), carboxy-polycaprolactone acrylate (-41 ° C), monohydroxyethyl acrylate succinate (-40
℃), styrene (100 ℃) and other vinyl aromatic compounds,
Vinyl halides such as vinyl chloride (80 ° C) and vinylidene chloride (-20 ° C), vinyl acetate (30 ° C), vinyl esters such as vinyl propionate (10 ° C), ethylene (-125 ° C), butadiene (-109). ℃) etc. and other acrylonitrile (130 ℃)
Etc.

The term "hydrophobic" as used herein means that the solubility in water at 20 ° C. is 8 g / 100 ml or less.

In the resin constituting the shell part (A) of the core-shell type polymer as the thermoplastic resin used in the present invention, the content of the hydrophobic monomer (b) component is 40 to 97% by mass. Is preferably used for. That is, the miscibility of the resin forming the shell part (A) and the acrylic resin forming the core part (B) is ensured, thickening during storage is suppressed, and sufficient adhesive properties after heating are obtained. In order to obtain the expression, the content is preferably 40% by mass or more, and is preferably 97% by mass or less in order to suppress aggregation and precipitation of the resin constituting the shell part (A). More preferably, it is in the range of 50 to 95 mass%.

Specific examples of the other monomer (c) include acrylamide (153 ° C.), 2-hydroxyethyl acrylate (-15 ° C.) and diacetone acrylamide (65 ° C.).

The component (c) can be used for ensuring the water solubility of the resin or adjusting the Tg described later.
In the resin constituting the shell part (A) of the core-shell type polymer as the thermoplastic resin used in the present invention, the content of the other monomer (c) component is used so as to account for 0 to 50% by weight. Preferably. That is, 50% by mass or less is preferable in order to maintain the miscibility with the acrylic resin forming the core component (B) and at the same time, to easily keep the viscosity of the aqueous emulsion of the core-shell polymer constant. The range is more preferably 40% by mass or less.

The resin which constitutes the shell portion (A) of the core-shell type polymer exhibits adhesiveness when the pressure-sensitive adhesive composition is applied / dried and when the coated sheet is stored in a roll form. It is a component for suppressing, and therefore, the Tg of the resin is preferably 30 ° C. or higher so as not to exhibit tackiness at room temperature. It is preferably 30 ° C. or higher in order to prevent the adhesiveness from already developing at the time of coating / drying of the adhesive composition, and also enables the heating temperature for expressing the adhesiveness to be set low, resulting in energy consumption. Reduction,
Further, it is preferably 130 ° C. or lower in order to prevent thermal deformation deterioration of the base material of the coated product. More preferably 50 ° C to 130
℃.

The resin constituting the shell portion (A) of the core-shell type polymer preferably contains 5% by mass or more of the solubilized resin in the resin. More preferably, it is 10 mass% or more.

In the present specification, solubilization refers to the degree of water solubility of the resin, and the solubilization rate as a numerical value is defined below. That is, the solubilization rate is obtained by diluting a resin-containing solution obtained by polymerization by a polymerization method described later with water so that the nonvolatile content becomes 15% by mass, and then diluting the diluted solution with a centrifugal acceleration of 1.8 × 105 g. Centrifuging for 60 minutes, the non-volatile content in the resulting supernatant was measured to be w parts by mass, and the non-volatile content in the diluent used for centrifugation was measured to be W parts by mass. The solubilization rate represented by the formula.

[0023] Solubilization rate = (w / W) x 100 (mass%)

Therefore, for example, when the copolymerization is carried out by adding an alkali and / or an organic solvent to the polymerization system before or during the polymerization for producing the resin-containing solution of the shell part (A). If the solubilization rate of the polymerization product containing the copolymer resin obtained by the polymerization is already 5% by mass or more, the alkali and / or the solubilization treatment is performed again. It is not necessary to add an organic solvent.

The alkali used for the solubilization treatment is an inorganic water-soluble alkali such as sodium hydroxide or potassium hydroxide; or an inorganic salt which shows alkalinity when dissolved in water, such as sodium hydrogen carbonate or pyrophosphate. Sodium and the like; ammonia water, organic amines and the like can be mentioned. As described above, the addition of the alkali does not necessarily have to be performed after the polymerization of the resin-containing solution, and in some cases, the alkali may be added to the monomer before the polymerization to neutralize it, and then the copolymerization may be performed. Good. The amount of alkali used may be an amount that completely neutralizes the carboxyl groups in the copolymer resin or an amount that partially neutralizes the carboxyl groups.

Since the resin constituting the core part (B) of the core-shell type polymer has a function of expressing tackiness in the pressure-sensitive adhesive composition, Tg is preferably -10 ° C or lower, more preferably Is −30 ° C. or lower.

The resin component constituting the core portion (B) includes the unsaturated monomer (a) having a carboxyl group exemplified in the shell portion (A), the hydrophobic monomer (b) and other mono-components. It can be obtained by copolymerizing a more hydrophobic monomer as a mixture from the body (c). For example, butyl acrylate (-54 ° C), 2-ethylhexyl acrylate (-8
5 ° C.), lauryl acrylate (−65 ° C.) and the like, which are mainly composed of monomers having a low glass transition temperature of a homopolymer. It is also possible to copolymerize ethylene (-125 ° C) or butadiene (-109 ° C) in order to adjust the glass transition temperature. It is obtained by emulsion-polymerizing a more hydrophobic monomer in the presence of a hydrophilic shell component resin.

In the delayed tack type adhesive label obtained by coating the delayed tack type adhesive composition of the present invention on a paper substrate, the resin constituting the core portion (B) of the core-shell type polymer has an adhesive property after heating. At the same time as contributing to expression, the resin constituting the shell part (A) of the core-shell type polymer contributes to suppressing blocking during storage before use. In order to optimize the balance between the two, the mass ratio of the resin (nonvolatile matter) that constitutes the shell portion (A) of the core-shell type polymer and the resin (nonvolatile matter) that constitutes the core portion (B) is (A ) / (B) is 10/90 to 50/50
Is preferred, and 20/80 to 50/50 is more preferred.

As the method for producing the shell part (A), for example, in a conventional manner, a mixture of the constituent monomers is polymerized with an initiator such as benzoyl peroxide and t-butyl hydroperoxide. And solution polymerization using an azo-based initiator such as azobisisobutyronitrile. At this time, it is also possible to use a chain transfer agent such as an organic halide or an alkyl mercaptan as a molecular weight regulator. It can be obtained by distilling off the solvent from the resin solution thus obtained under reduced pressure, then adding water and, if necessary, further adding an alkali and / or a solvent.

As another method for producing the resin-containing solution which is the component of the shell part (A), according to a conventional emulsion polymerization, that is, the monomer mixture constituting the copolymerization is emulsion-copolymerized by using an emulsifier, There is also a method of adding an alkali to solubilize water, but in this method, it is essential to use a chain transfer agent for controlling the molecular weight. The alkali used herein may be ammonia, an organic amine such as triethylamine or ethanolamine, or an inorganic alkali such as sodium hydroxide, but it is most preferable to use ammonia.

As a method for producing the resin emulsion of the core part (B), the shell part (A) of the present invention is used as a polymeric emulsifier to copolymerize a monomer mixture constituting a resin according to a conventional method of emulsion polymerization. There is a method.

As the thermoplastic resin, a core-shell polymer may be used in combination with another thermoplastic resin. Other thermoplastic resins such as acrylic acid ester, styrene-acrylic acid ester, styrene-butadiene, vinyl acetate, ethylene-vinyl acetate, vinyl acetate-acrylic acid ester, ethylene-acrylic acid ester, ethylene-acrylic acid, butadiene copolymer, Examples of the thermoplastic resin include urethane and styrene-isoprene block polymer.

The tackifier used in the delayed tack adhesive composition of the present invention includes, for example, terpene resin, aliphatic petroleum resin, aromatic petroleum resin, coumarone-indene resin, styrene resin, phenol resin, Softening temperature of terpene-phenol resin, rosin derivative (rosin, polymerized rosin, hydrogenated rosin and their esters with glycerin, pentaerythritol, etc., resin acid dimer, etc.) is 100 to 170 ° C. An aqueous dispersion of tackifier is mentioned.

The solid plasticizer used in the delayed tack pressure-sensitive adhesive composition of the present invention includes thermoplastic resins such as those described in "Adhesive Handbook" such as dicyclohexyl phthalate (12th edition, 1980, published by Kobunshi Kogyokai). There are crystalline ester compounds that are compatible with the resin. The solid plasticizer has a melting point of 60 ° C. or higher so as not to exhibit adhesiveness when the adhesive composition is applied / dried and when the applied sheet is stored in a roll form. preferable. More preferably 7
It is 0 ° C to 130 ° C. If the melting point is less than 60 ° C, the tackiness may already be developed during coating and drying of the pressure-sensitive adhesive composition, and if the melting point is too high, the heating temperature for causing the tackiness to develop. May result in high energy consumption, high energy consumption, and thermal deformation of the base material of the coating product.

Benzoic acid ester compounds, hindered phenol ester compounds and the like are preferably used as preferable solid plasticizers. Examples of the benzoic acid ester compound include sucrose benzoate, diethylene glycol benzoate, glyceride benzoate, pentaerythritol benzoate, trimethylolethane benzoate, trimethylolpropane benzoate, and trimethylolpropane benzoate. Esters are particularly preferably used.

Other preferred solid plasticizers are hindered phenol ester compounds. For example, triethylene glycol bis [3- (3-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5)
-Methylphenyl) propionate], triethylene glycol bis [3- (3,5-di-t-butyl-4-hydroxy-phenyl) propionate], 1,6-hexanediol bis [3- (3-t-butyl) -4-Hydroxyphenyl) propionate], 1,6-hexanediol bis [3- (3-t-butyl-4-hydroxy-
5-Methylphenyl) propionate], 1,6-hexanediol bis [3- (3,5-di-t-butyl-4]
-Hydroxyphenyl) propionate], thiobis [ethylene 3- (3-t-butyl-4-hydroxyphenyl) propionate], thiobis [ethylene 3- (3
-T-butyl-4-hydroxy-5-methylphenyl)
Propionate], thiobis [ethylene 3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate]. Particularly preferred solid plasticizers include triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] and 1,6-hexanediol bis [3- (3,5
-Di-t-butyl-4-hydroxyphenyl) propionate], thiobis [ethylene 3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate].

These solid plasticizers can be used as a mixture of two or more kinds. Aqueous dispersions of solid plasticizers need to maintain a dispersed particle size below a certain level in order to prevent sedimentation and to maintain the smoothness of the coating, and therefore, they are pulverized and dispersed by a ball mill, a handy mill, etc., if necessary. It

To obtain the delayed tack adhesive composition for the purpose of the present application, a thermoplastic resin containing the above core-shell polymer, an aqueous dispersion of a solid plasticizer and an aqueous dispersion of a tackifier such as a rosin ester are used. Further, the mass ratio of the solid content is preferably 20 to 40:50 to 70:10 to 20.

Further, a surfactant, an antifoaming agent, a lubricant, a coloring agent, and a filler may be added to the resin composition within the range not impairing the object of the present invention. If the coating amount of the delayed tack type adhesive to the paper-based substrate is small, the initial adhesion to the adherend will be insufficient, and if it is too large, it will be difficult to obtain a smooth coated surface and the drying property will also decrease. 5 to 25 g / m2, depending on paper quality
Is preferable, and 8 to 18 g / m 2 is particularly preferable. For coating, a general-purpose coating machine such as a gravure coater, a roll coater, a lip coater and a bar coater can be used.

Another structure of the present invention is characterized in that it is a label in which the above-mentioned pressure-sensitive adhesive composition is provided on a label base material. The label substrate includes plastic film and paper, and paper is preferably used.

[0041]

EXAMPLES The present invention will be specifically described with reference to the following examples. However, the scope of the present invention is not limited to the following examples. In the examples, "part" means "mass part", "%"
Represents mass% respectively.

[Production Example 1] 150 parts of methyl cellosolve was charged into a reactor equipped with a temperature controller, a stirrer, a reflux condenser, a supply container and a nitrogen introducing tube, and the atmosphere was replaced with nitrogen. After heating the reactor to 80 ° C., 100 parts of a monomer mixed solution consisting of 65 parts of methyl methacrylate, 15 parts of butyl acrylate and 20 parts of acrylic acid and 0.1 part of t-dodecyl mercaptan.
Part of the mixture was added uniformly from a supply container I, and 2 parts of azobisisobutyronitrile dissolved in 50 parts of methyl cellosolve were uniformly added from the supply container II over 4 hours.

After completion of the addition, the reactor was kept at 80 ° C. and aged for 2 hours to obtain a uniform polymer solution. Then, by using a rotary evaporator under reduced pressure, methyl cellosolve was almost completely distilled off, and then deionized water was added,
Ammonia is further added to neutralize the solution, and the pH is 8 and the nonvolatile content is 25.
% Of the shell part (A) resin-containing solution was obtained. Got,
The Tg (calculated value) of the resin forming the shell part (A) is 68.
It was ℃. The solubilization rate of the resin in this resin-containing solution was 100%, and the weight average molecular weight was about 5 when measured by gel permeation chromatography (GPC).
It was 000.

Then, 100 parts of the resin-containing solution prepared above was charged into the reactor using the same apparatus as above. Separately, as the supply (i), 90 parts of butyl acrylate, 9.5 parts of methyl methacrylate, and 0.5 parts of methacrylic acid were prepared. Separately, as a feed (ii), an initiator solution was prepared by dissolving 0.6 part of sodium persulfate and 0.15 part of sodium hydroxide in 20 parts of water.

After replacing the inside of the reaction vessel with nitrogen gas,
1 of each of the above feeds (i) and (ii) in the same reaction vessel
0% was added and the mixture was heated to 90 ° C. Then
The rest of the feeds (i) and (ii) were uniformly fed into the same reaction vessel over 3 hours. After the end of the supply, emulsion polymerization was carried out at 90 ° C. for 1.5 hours to obtain an aqueous emulsion of core-shell type polymer. The nonvolatile content of this aqueous emulsion was about 52%, and the Tg (calculated value) of the core part (B) resin was -44 ° C.

[Production Example 2] In Synthesis Example 1, when synthesizing the core portion (B), 140 parts of the shell portion (A) resin-containing solution prepared in Production Example 1 was charged instead of 140 parts. Reactions were carried out in the same manner as in Production Example 1 except for the above, to obtain an aqueous emulsion of the core-shell type polymer. The nonvolatile content of this aqueous emulsion was about 48%, and the Tg (calculated value) of the core part (B) resin was -44 ° C.

[Production Example 3] Using the same apparatus as in Production Example 1, 40 parts of water and 0.06 part of sodium persulfate were charged into the reactor. Separately butyl acrylate 95 as feed (i)
Parts, 24.5 parts of methyl methacrylate, 5 parts of acrylic acid,
Methacrylic acid 0.5 part, t-dodecyl mercaptan 0.
A mixture of 025 parts, 50 parts of water, and 8 parts of 30% aqueous solution of sulfuric acid ester sodium salt of nonylphenol ethylene oxide 20 mol adduct was prepared. Separately, the supply (i
As i), an initiator solution was prepared by dissolving 0.8 part of sodium persulfate in 12 parts of water.

After the inside of the reactor charged with the above-mentioned initiator solution was replaced with nitrogen gas, the above-mentioned feed (i) was fed into the same reactor.
Was added and the mixture was heated to 90 ° C. Then, 10% of the feed (ii) was charged into the same reactor, and the remainder of the feed (i) and the feed (ii) was 3 to 3.5.
It was uniformly fed to the reactor over time. After the end of the supply, the mixture was kept at 90 ° C. for 1.5 hours for emulsion polymerization to obtain a resin aqueous emulsion. The nonvolatile content of this aqueous emulsion is about 52%, and the Tg (calculated value) of the resin is -28 ° C.
Met.

[Production Example 4] Using the same apparatus as in Production Example 1, 40 parts of water and 0.06 part of sodium persulfate were charged into the reactor. Separately ethyl acrylate 50 as feed (i)
Parts, 24.5 parts of methyl methacrylate, 6 parts of acrylic acid,
Styrene 15 parts, t-dodecyl mercaptan 0.025
Parts, water 40 parts, nonylphenol ethylene oxide 20
A mixture of 6.5 parts of a 30% aqueous solution of sulfuric acid ester sodium salt of a mole addition product was prepared. Separately, the supply (i
As i), an initiator solution was prepared by dissolving 0.7 part of sodium persulfate in 10 parts of water.

After the inside of the reactor charged with the above initiator solution was replaced with nitrogen gas, the above-mentioned feed (i) was fed into the same reactor.
Was added and the mixture was heated to 90 ° C. Then, 10% of the feed (ii) was charged into the same reactor, and the remainder of the feed (i) and the feed (ii) was 3 to 3.5.
It was uniformly fed to the reactor over time. After the end of the supply, the mixture was kept at 90 ° C. for 1.5 hours for emulsion polymerization to obtain a resin aqueous emulsion. The nonvolatile content of this aqueous emulsion was about 50%, and the Tg (calculated value) of the resin was 25 ° C.

Example 1 Powder and granular benzoyl trimethylolpropane ester (melting point: 85 ° C.) 55 parts, ion-exchanged water 40 parts, powder and granular acrylic ester-acrylic acid copolymer resin (methyl methacrylate / butyl acrylate acrylic acid = 70) / 20/20, molecular weight 15000) 4 parts and 28% ammonia water 0.2 parts were put into a ball mill and kneaded for a predetermined time until dispersed particles became 2 μ or less. To 60 parts of the obtained aqueous dispersion, 30 parts of the core-shell type acrylic emulsion obtained in Production Example 1 and further rosin emulsion (Super Ester E-730: manufactured by Arakawa Chemical Co., Ltd.)
An aqueous pressure-sensitive adhesive dispersion liquid (solid content: 55%) containing 10 parts was prepared. The obtained aqueous pressure-sensitive adhesive dispersion was directly applied onto single-sided art paper so that the application amount was 20 g / m 2, and dried at 45 ° C. for 2 minutes. In this state, tackiness could not be confirmed. Table 1 shows the results of evaluation of the adhesiveness and blocking property of the coated article. Further, after heating the coated product at 120 ° C. for 1 minute to develop tackiness,
Table 1 shows the results of measuring the adhesive strength by bonding to a glass plate.
Shown in.

[Example 2] [0052] Example 2 except that the core-shell type acrylic emulsion obtained in Production Example 1 was replaced with 30 parts of the core-shell type acrylic emulsion obtained in Production Example 2 in the same amount. A pressure-sensitive adhesive was prepared in the same manner as in No. 1, and the obtained pressure-sensitive adhesive was directly applied on single-sided art paper, dried, and the coated product was evaluated.

[Example 3] Powdered and granular benzoic acid trimethylolpropane ester (melting point 85 ° C) 5 in Example 1
Instead of 5 parts, powdered granular triethylene glycol bis [3
-(3-t-Butyl-4-hydroxy-5-methylphenyl) propionate (melting point 77 ° C)] was mixed in the same amount as in Example 1 except that the resulting pressure-sensitive adhesive was prepared. Table 1 shows the results of the evaluation of the coated product after direct coating on one-sided art paper and drying.

Comparative Example 1 The same as Example 1 except that the core-shell acrylic emulsion obtained in Production Example 1 was replaced with the acrylic copolymer emulsion obtained in Production Example 3 in the same amount. Prepare the adhesive,
Apply the obtained adhesive directly on one sided art paper, 45 ℃
After drying for 2 minutes, the coated surface was already tacky, so the following test was unavoidably stopped.

Comparative Example 2 The same as Example 1 except that the core-shell acrylic emulsion obtained in Production Example 1 was replaced with the acrylic copolymer emulsion obtained in Production Example 4 in the same amount. Prepare the adhesive,
Directly apply the obtained adhesive to single-sided art paper, and after drying,
The results of evaluation of the coated product are shown in Table 1.

In order to evaluate the adhesive strength for evaluating the adhesiveness for evaluating the coating properties of the delayed tack type pressure-sensitive adhesive aqueous dispersions in Examples and Comparative Examples, and the storage stability for the coated products. The blocking property was evaluated by the following method.

(Adhesive Strength Test) After the adhesiveness was developed by heating, the adhesive coating was quickly applied to a float glass plate, and the adhesive strength immediately after and 1 day after 180 ° peeling was measured according to JISK-6848. The measurement was performed, and the strength after one day was judged according to the following criteria. However, the glued portion was 100 mm. ○: Adhesive strength is 4N / 15mm or more or paper is broken and adheres well to the bottle △: Adhesive strength is 2N / 15mm or more, less than 4N / 15mm, it can be peeled by hand without breaking the substrate × : Adhesive strength is less than 2N / 15mm and can be easily peeled off by hand

(Blocking property) The pressure-sensitive adhesive layer of the pressure-sensitive adhesive coating and the printing layer on the back surface were overlapped with each other, a load of 0.1 mPa was applied, and the mixture was stored at a predetermined temperature (shown in the table) for 5 hours and then peeled off. Judgment was carried out based on the criteria, and at 60 ° C., 4 or more was ◯, 3 was Δ, and 2 or less was X. 5: Peeling without resistance when peeling 4: Some noise when peeling. 3: Ink marks remain on the printed surface during peeling 2: Part of the paper on the printed surface peels off during peeling 1: The paper on the printed surface breaks during peeling

[0059]

[Table 1]

However, P in Table 1 indicates paper destruction.

[0061]

The effect of the present invention is that by using a thermoplastic resin containing a core-shell type polymer for a heat-sensitive delayed tack type pressure-sensitive adhesive, its coating can be performed without raising the temperature conditions for expressing the tackiness. Dryability during work and
The delayed tack adhesive composition has excellent blocking resistance during storage of the coated material and excellent adhesiveness. The heat-sensitive delayed tack type adhesive and label of the present invention can provide a label that is environmentally friendly and does not require release paper, and can pursue safety and economic benefits. The significance is extremely large.

Continued front page    F-term (reference) 4J004 AA01 AA10 AA17 AB01 CB02                       CC02 FA01 FA08                 4J040 BA202 DB042 DK012 DL121                       DN032 DN072 EB032 GA01                       GA03 GA07 GA13 HB32 HB33                       JA03 JA09 KA26 KA31 LA02                       NA21

Claims (8)

[Claims] 1. An aqueous dispersion type delayed tack type pressure-sensitive adhesive composition comprising a thermoplastic resin, a tackifying resin and a solid plasticizer, wherein the delayed resin contains a core-shell type polymer as the thermoplastic resin. Tack type adhesive composition. 2. The glass transition temperature (Tg) of the shell portion of the core-shell type polymer is 30 ° C. or higher, and the T of the core portion is T.
The delayed tack type | mold adhesive composition of Claim 1 whose g is -10 degreeC or less. 3. The mass ratio (shell part) / (core part) of the non-volatile components of each component of the core-shell type polymer is from 10/90.
The delayed tack type pressure-sensitive adhesive composition according to claim 1, which is 50/50. 4. The T of the shell portion of the core-shell type polymer
g is 50 to 130 ° C., Tg of the core part is −30 ° C. or less, and the mass ratio (shell part) / (core part) of the non-volatile components is 20/80 to 50/50. The delayed tack type pressure-sensitive adhesive composition according to claim 1. 5. The solid plasticizer has a melting point of 70 to 130 ° C.
The delayed tack type pressure-sensitive adhesive composition according to claim 1, which is an ester compound of 6. The delayed tack type pressure-sensitive adhesive composition according to claim 1, wherein the solid plasticizer is a benzoic acid ester compound. 7. The delayed tack type pressure-sensitive adhesive composition according to claim 1, wherein the solid plasticizer is a hindered phenol ester compound. 8. A delayed tack type pressure-sensitive adhesive label, comprising the delayed tack type pressure-sensitive adhesive composition layer according to claim 1 provided on a label substrate.