JP2005206779A - Aqueous dispersion of composite resin composition for adhesive and adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous dispersion of a composite resin composition for an adhesive, capable of forming an adhesive composition having excellent cohesive force, high bonding force to a polyolefin material to be bonded and a good waterproof property. <P>SOLUTION: This aqueous dispersion of the composite resin composition for the adhesive is obtained by polymerizing (A) a radically polymerizable ethylenically unsaturated monomer in an aqueous medium consisting of (B) an aqueous dispersion of a polyolefin, a surfactant, a polymerization initiator and water as essential components. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives. More specifically, the present invention relates to an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives that can form a pressure-sensitive adhesive composition having excellent cohesive strength, high adhesion to polyolefin adherends, and good water resistance. More specifically, both components can be combined by polymerizing an ethylenically unsaturated monomer capable of radical polymerization in the presence of an aqueous dispersion of polyolefins. It is related with the composite resin composition aqueous dispersion for adhesives which can form an agent composition.
Furthermore, this invention relates to the aqueous adhesive composition containing the said composite resin composition aqueous dispersion for adhesives.
Moreover, this invention relates to the manufacturing method of the said composite resin composition aqueous dispersion for adhesives.

  In recent years, solvent removal has progressed in consideration of safety and health and environmental problems, and the shift from solvent type to aqueous type is also progressing in adhesives. However, in water-based pressure-sensitive adhesives, emulsion particles are fused to form a dry film in the drying process after coating. There was a disadvantage that the adhesive strength to the polyolefin adherend was poor.

By adjusting the glass transition temperature of the resin produced by selecting the ethylenically unsaturated monomer, which is the main component of the water-based adhesive resin, or by changing the amount of polymerization initiator used, Attempts have been made to overcome these drawbacks by adjusting the molecular weight.
However, when the glass transition temperature is set high or the molecular weight is increased, the cohesive force is improved, but the adhesive force tends to decrease. Conversely, when the glass transition temperature is set low or the molecular weight is decreased. Although the adhesive force was improved, the cohesive force tended to decrease contrary, and it was difficult to make these two physical properties compatible with each other before practical use.

On the other hand, attempts have been made to add an aqueous dispersion of an olefin polymer as an additive to the main component of the aqueous pressure-sensitive adhesive in order to improve the adhesion to the polyolefin adherend.
However, when an aqueous dispersion of an olefin polymer is simply added and blended, unless a large amount of the olefin aqueous dispersion is added, not only the effect of improving the adhesive strength is exhibited, but no improvement is seen in the cohesive strength. And as the adhesion to polyolefin adherend improves, adding and blending a large amount of the olefin polymer aqueous dispersion causes the pressure sensitive adhesive to be affected by the surfactant contained in the olefin polymer aqueous dispersion. There is an adverse effect that the water resistance of the dried coating film deteriorates.

Further, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 11-12329) discloses an attempt to obtain a composite resin by dissolving a solid or semi-solid polyolefin resin in an ethylenically unsaturated monomer so as to coexist in the reaction system. Publication). However, for the purpose of controlling the physical properties of the polymer, the ethylenically unsaturated monomer is generally used in combination with a plurality of types, and depending on the content of the composition, the polyolefin resin may be an ethylenically unsaturated monomer. Since it becomes difficult to dissolve in the mixture or becomes insoluble, there arises a problem that the process load at the time of producing the polymer becomes large or it cannot be substantially dissolved.
Japanese Patent Laid-Open No. 11-12329

  An object of the present invention is to provide an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives that can form a pressure-sensitive adhesive composition having excellent cohesive strength, high adhesion to polyolefin adherends, and good water resistance. is there.

In the first invention, the radically polymerizable ethylenically unsaturated monomer (A) is mixed with an aqueous dispersion of a polyolefin (B), a surfactant, a polymerization initiator and water as essential components. Regarding the composite resin composition aqueous dispersion for pressure-sensitive adhesive obtained by polymerization,
The second invention is characterized in that the radically polymerizable ethylenically unsaturated monomer (A) / polyolefins (B) = 99.95 / 0.05 to 90/10 (weight ratio). It is related with the composite resin composition aqueous dispersion for adhesives as described in invention.

  A third invention relates to an aqueous pressure-sensitive adhesive composition comprising the composite resin composition aqueous dispersion described in any one of the above inventions.

Moreover, 4th invention is the aqueous medium which uses the radically polymerizable ethylenically unsaturated monomer (A) as an essential component for the aqueous dispersion of polyolefin (B), surfactant, a polymerization initiator, and water. A method for producing an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives, characterized by polymerization in
The fifth invention is characterized in that the radically polymerizable ethylenically unsaturated monomer (A) / polyolefins (B) = 99.95 / 0.05 to 90/10 (weight ratio). The present invention relates to a method for producing an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives described in the invention.

  The aqueous dispersion of the composite resin composition for pressure-sensitive adhesives of the present invention is a pressure-sensitive adhesive composition that can satisfy all the conflicting requirements of high cohesion and good adhesion to polyolefin adherends without impairing water resistance. Can be provided. In addition, the pressure-sensitive adhesive product formed from the pressure-sensitive adhesive composition containing the aqueous dispersion of the composite resin composition for pressure-sensitive adhesives of the present invention adheres even when exposed to high temperatures in a state of being stuck to an adherend. The degree of power decrease is small and heat resistance is excellent.

  Examples of the ethylenically unsaturated monomer (A) used in the present invention include (a) alkyl acrylate and alkyl methacrylate having 1 to 14 carbon atoms in the alkyl group. (A) As alkyl acrylate and alkyl methacrylate having 1 to 14 carbon atoms in the alkyl group, methyl (meth) acrylate, [methyl methacrylate and methyl methacrylate are collectively referred to as methyl (meth) acrylate. The same applies below. ], Ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate or the like Examples include acrylic esters of branched aliphatic alcohols and corresponding methacrylic esters. Among them, (meth) acrylic acid alkyl esters having 4 to 12 carbon atoms in the alkyl group are preferably used. These are contained in an amount of 70 to 99.5% by weight in 100% by weight of the ethylenically unsaturated monomer (A), and can be used alone or in combination of two or more.

The monomer (a) is preferably copolymerized with (b) an ethylenically unsaturated monomer having a carboxyl group.
(B) Examples of the ethylenically unsaturated monomer having a carboxyl group include (meth) acrylic acid, maleic acid, fumaric acid, and itaconic acid. These are contained in an amount of 0.5 to 5% by weight in 100% by weight of the ethylenically unsaturated monomer (A), and can be used alone or in combination of two or more.

As the monomer other than (a) and (b), (c) a copolymerizable (meth) acrylic monomer having an alcoholic hydroxyl group or ( d) A copolymerizable (meth) acrylic monomer having a carbonyl group is used.
(C) Examples of the copolymerizable acrylic monomer having an alcoholic hydroxyl group include 2-hydroxylethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxylbutyl (meth) acrylate and the like. These are contained in an amount of 0.5 to 5% by weight in 100% by weight of the ethylenically unsaturated monomer (A), and can be used alone or in combination of two or more.
(C) When using a copolymerizable acrylic monomer having an alcoholic hydroxyl group, as a crosslinking agent that can be blended when obtaining a pressure-sensitive adhesive composition, isocyanate compounds, metal alkoxide compounds such as titanium and zirconium Etc.

(D) As a copolymerizable acrylic monomer having a carbonyl group, acrolein, diacetone (meth) acrylamide, formylstyrene, preferably a vinyl alkyl ketone having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl Ethyl ketone, vinyl isobutyl ketone, etc.), diacetone (meth) acrylate, acetonyl (meth) acrylate, acetoacetoxyethyl (meth) acrylate, diacetone (meth) acrylate, 2-hydroxypropyl (meth) acrylate-acetyl acetate, butanediol- Examples thereof include 1,4- (meth) acrylate-acetyl acetate.
These are contained in an amount of 0.5 to 5% by weight in 100% by weight of the ethylenically unsaturated monomer (A), and can be used alone or in combination of two or more.
(D) When a copolymerizable acrylic monomer having a carbonyl group is used, examples of the crosslinking agent that can be blended in obtaining the pressure-sensitive adhesive composition include amines and hydrazide compounds.

  Other monomers include polyethylene glycol (meth) acrylate, glycidyl (meth) acrylate, mono- (2-hydroxylethyl-α-chloro (meth) acrylate) acid phosphate, vinyl blocked isocyanate, N-methylol (meta ) Acrylamide, N-methylaminoethyl (meth) acrylate, N-tributylaminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-diethylaminoethyl (meth) acrylate, (meth) acrylamide , Vinyl pyrrolidone, vinyl ester, vinyl pyridine, vinyl acetate, vinyl propionate, styrene, (meth) acrylonitrile, butadiene, chloroprene and the like. These can be contained at 30% by weight or less, if necessary, and can be used alone or in combination of two or more.

Furthermore, the dispersed particles in the aqueous dispersion of the composite resin composition for pressure-sensitive adhesives of the present invention may have an intraparticle crosslinked structure.
As the intraparticle crosslinking agent, various polyfunctional monomers such as diallyl ester of phthalic acid and polyfunctional acrylic monomers can be used.
Examples of phthalic acid diallyl esters include orthophthalic acid, isophthalic acid, and terephthalic acid diallyl esters.
The polyfunctional acrylic monomers include methylene bis (meth) acrylamide, 1,6-hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipenta An example is erythritol hexa (meth) acrylate. These are contained in 0.1 to 3% by weight in 100% by weight of the ethylenically unsaturated monomer (A), and can be used alone or in combination of two or more.

Examples of the aqueous dispersion of polyolefins (B) used in the present invention include those obtained by dispersing polyolefins (B) in water by various methods. For example,
(1) After synthesizing the polyolefin (B) in the absence of a solvent, a surfactant and water are added, and an aqueous dispersion is obtained by a method such as forced stirring,
(2) After synthesizing the polyolefin (B) in an organic solvent, after removing the solvent after completion of the synthesis reaction, a surfactant and water are added to form an aqueous dispersion by a method such as forced stirring, or the synthesis reaction is completed. A surfactant and water can be added later, followed by removal of the solvent to obtain an aqueous dispersion.
Moreover, when polyolefin (B) is synthesize | combined in water, it can use for this invention as it is, without performing a post-process in particular.
Examples of such aqueous dispersions of polyolefins (B) include polyolefin aqueous dispersions “S-6008” and “S-6007” (both solid content 30%) manufactured by Nippon Paper Chemicals Co., Ltd. it can.
Examples of the surfactant used for obtaining the aqueous dispersion of polyolefins (B) include the same surfactants used when obtaining the aqueous dispersion of the composite resin composition for pressure-sensitive adhesive described later. .

Examples of the polyolefin (B) include a homopolymer of ethylene or propylene, a copolymer of ethylene and propylene, and a copolymer of ethylene and / or propylene and other copolymerizable monomers. Other copolymerizable monomers include, for example, α-olefin monomers having 2 or more carbon atoms, preferably 2-6, such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene. Is mentioned.
In addition, for the purpose of improving the dispersibility of polyolefins (B) in water, one or more of the ethylenically unsaturated monomers (A) already exemplified are copolymerized with ethylene, propylene or the like (random copolymerization). Those obtained by combining, block copolymer or graft polymer) can also be used as polyolefins (B).
Further, in the presence of polypropylene, polyethylene, or acid-grafted polyolefin obtained by graft polymerization of an acid anhydride or carboxylic acid having an ethylenically unsaturated double bond capable of radical polymerization on a copolymer of propylene, ethylene and α-olefin. In addition, composite resins obtained by polymerizing acrylic or methacrylic monomers exemplified as the ethylenically unsaturated monomer (A) can also be used as the polyolefins (B) in the present invention. When the acrylic or methacrylic monomer is polymerized in the presence of the acid-grafted polyolefin, it is preferable to use an organic peroxide as a polymerization initiator.

The aqueous dispersion of the composite resin composition for pressure-sensitive adhesives of the present invention is obtained by polymerizing a radically polymerizable ethylenically unsaturated monomer (A) in the presence of an aqueous dispersion of polyolefins (B). Yes, aqueous dispersion of polyolefins (B) such that the polyolefins (B) are 0.05 to 10 parts with respect to 99.95 to 90 parts of the ethylenically unsaturated monomer (A) capable of radical polymerization It is preferable to use a polymer such that the polyolefin (B) is 0.1 to 5 parts relative to 99.9 to 95 parts of the radically polymerizable ethylenically unsaturated monomer (A). More preferably, the aqueous dispersion B) is used.
If the amount of the polyolefin (B) is small, the effect of improving the adhesive strength to the polyolefin adherend tends to be insufficient. Further, when the amount of the aqueous dispersion of the polyolefin (B) is increased in order to increase the polyolefin (B), a large amount of the surfactant in the aqueous dispersion is also used, and as a result, the resulting adhesive The water resistance of the dried coating film of the pressure-sensitive adhesive containing the aqueous composite resin composition for an agent tends to be lowered. Therefore, as described above, with respect to 99.95 to 90 parts of radically polymerizable ethylenically unsaturated monomer (A), polyolefins (B) are in a state of 0.05 to 10 parts, It is preferable to polymerize the radically polymerizable ethylenically unsaturated monomer (A) in the presence of an aqueous dispersion of polyolefins (B).

As the surfactant used when obtaining the aqueous dispersion of the composite resin composition for pressure-sensitive adhesives of the present invention, a reactive surfactant, a non-reactive surfactant, etc. may be used alone or in combination of two or more. However, in consideration of water resistance, it is preferable to use a reactive surfactant.
The following compounds can be illustrated as a reactive surfactant. As anionic surfactants, long chain alkyl skeletons such as “Adekaria Soap SE-10N” manufactured by Asahi Denka Kogyo Co., Ltd. and “Aqualon HS-10, HS-20” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. Examples include “AQUALON KH-05, KH-10” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Adekaria Soap SR-10N” manufactured by Asahi Denka Kogyo Co., Ltd., “KAYARAD” manufactured by Nippon Kayaku Co., Ltd. with a phosphate ester skeleton, etc. it can.
Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene phenyl ethers, sorbitan higher fatty acid esters, and glycerin higher fatty acid esters having an unsaturated double bond at the molecular end or in the middle. Limited to those copolymerized with the monomer. "Adekaria soap NE-10" manufactured by Asahi Denka Kogyo Co., Ltd., "Aqualon RN-10, RN-20, RN-50" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., "Antox NA-16" manufactured by Nippon Emulsifier Co., Ltd. Can be illustrated.

  As the polymerization initiator used in the present invention, a persulfate such as potassium persulfate or ammonium persulfate, a water-soluble thermal decomposition type superpolymerization catalyst such as an azobis cation salt or a hydroxyl group addition substance, or a redox polymerization catalyst is used. be able to. The redox polymerization catalyst includes a combination of an organic peroxide such as t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide and a reducing agent such as Rongalite, sodium metabisulfite, or potassium persulfate or ammonium persulfate. And combinations of Rongalite and sodium thiosulfate, and combinations of hydrogen peroxide and ascorbic acid.

  The aqueous dispersion of the composite resin composition for pressure-sensitive adhesives of the present invention is a mercaptan-based, thioglycol as a chain transfer agent for controlling the molecular weight and molecular weight distribution when the ethylenically unsaturated monomer (A) is polymerized. And thiol compounds such as β-mercaptopropionic acid, rosin compounds and terpene compounds having allyl hydrogen, and the like can be used. The addition amount is preferably 0.01 to 10.0 parts by weight with respect to 100 parts by weight of the total amount of the ethylenically unsaturated monomer (A) and the polyolefins (B), preferably 0.1 to 5 parts by weight. It is more preferable that

Next, the pressure-sensitive adhesive composition of the present invention will be described.
The pressure-sensitive adhesive composition of the present invention is mainly composed of the above-mentioned aqueous composite resin composition dispersion for pressure-sensitive adhesives, and the adhesive resin composite aqueous dispersion for pressure-sensitive adhesives is used for adjusting the adhesive strength as necessary. In addition, an appropriate amount of an appropriate tackifier such as rosin resin, phenol resin, polyterpene, acetylene resin, petroleum hydrocarbon resin, ethylene vinyl acetate copolymer, synthetic rubber, natural rubber and the like can be added. Further, a crosslinking agent, a viscosity modifier, an antifoaming agent, a leveling agent, a plasticizer, a filler, a neutralizing agent, a coloring agent, a silane coupling agent, an antiseptic, and the like may be added.

The pressure-sensitive adhesive composition of the present invention is applied onto a paper or film substrate or a peelable sheet by various coating apparatuses such as a comma coater, a reverse coater, a slot die coater, a lip coater, a gravure chamber coater, and a curtain coater. By drying, various pressure-sensitive adhesive coated products such as pressure-sensitive adhesive sheets and pressure-sensitive adhesive labels can be obtained. It is preferable to dry at 80 ° C. to 120 ° C. after applying the pressure-sensitive adhesive composition to paper or the like. When the drying temperature is 80 ° C. or lower, it is difficult to dry, and it takes a long time to dry. On the other hand, drying at a temperature higher than 120 ° C. is not preferable because it causes thermal deterioration of the substrate or the peelable sheet.
When the pressure-sensitive adhesive composition is applied on a paper or film substrate, it is bonded to the peelable sheet after drying. When the pressure-sensitive adhesive composition is applied to the peelable sheet, the paper or film base is dried. By adhering to the material, various adhesive coated products can be obtained by either method.
The peelable sheet is also called a separator, and is formed by peeling off at least one surface of paper or a plastic film. A conventionally known release treatment agent can be used.

The present invention will be described below with reference to examples, but is not limited thereto. In the examples, “part” means “part by weight” and “%” means “% by weight”.
(Production Example-1)
The inside of a four-necked flask equipped with a stirrer, a condenser, a thermometer and a dropping funnel was replaced with nitrogen gas, and an ethylene-propylene-α-olefin copolymer (propylene component 75 mol%, ethylene component 20 mol%, 1-butene component 5 mol%) 300 parts of toluene was heated and dissolved in 700 parts of toluene, and then the system temperature was maintained at 115 ° C. while stirring, 50 parts of maleic anhydride and di-tert-butyl peroxide as a radical generator. 12 parts of each were dropped over 2 hours, followed by aging for 3 hours. After the reaction, the reaction product was cooled to room temperature and then purified by putting it into 20 L of acetone to obtain a maleic anhydride graft copolymer.
Next, 200 parts of the above maleic anhydride graft copolymer was charged into a 4 L flask equipped with a stirrer having a volume of 2 L, and further 790 parts of 2-ethylhexyl methacrylate, 10 parts of methacrylic acid, 12 parts of benzoyl peroxide, and 12 parts of dodecyl mercaptan. Added and stirred to obtain a homogeneous solution.
To this solution, 900 parts of deionized water added with 150 parts of polyethylene oxide nonylphenyl ether (NS-230; manufactured by Nippon Oil & Fats, nonionic surfactant) was added and emulsified using a homogenizer at 14,000 rpm for 30 minutes. Next, 950 parts of deionized water was charged into a 3 L four-necked flask and the temperature was raised to 60 ° C. with stirring, and then the emulsion was added at a constant rate over 3 hours, and further reacted for 3 hours. The obtained emulsion was filtered through a # 400 SUS wire mesh to obtain a polyolefin aqueous dispersion (I) having a solid content of 30%.

(Example-1)
93.8 parts of 2-ethylhexyl acrylate, 5 parts of methyl methacrylate, 1 part of acrylic acid, 0.2 part of diacetone acrylamide, and 100 parts of these ethylenically unsaturated monomers are reactive ammonia neutralized anionic interface What was obtained by dissolving 2 parts of “AQUALON KH-10” manufactured by Daiichi Kogyo Seiyaku Co., Ltd. as an activator in 30.2 parts of deionized water was stirred and emulsified. Further, 3.33 parts of the polyolefin aqueous dispersion (I) was added and mixed to obtain an emulsion, which was placed in a dropping funnel.
A four-necked flask equipped with a stirrer, a condenser, a thermometer and the above dropping funnel was charged with 43.9 parts of deionized water and 0.1 part of Aqualon KH-10, and the inside of the flask was replaced with nitrogen gas. While stirring, the internal temperature was raised to 80 ° C., and 0.15 part of 3% potassium persulfate aqueous solution was added as a solid content. After 5 minutes, dropping of the emulsion was started from the dropping funnel, and in parallel with this, 0.45 part of 3% potassium persulfate aqueous solution was added dropwise from another dropping port over 3 hours.
While maintaining the internal temperature at 80 ° C., 30 minutes after the completion of dropwise addition of the above emulsion and 3% aqueous potassium persulfate solution, 0.06 parts were divided into two portions each containing 30% aqueous 3% potassium persulfate solution every 30 minutes. Added.
The mixture was further aged at 80 ° C. for 2 hours with stirring, then cooled and neutralized with aqueous ammonia to obtain an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives having a solid content of 51%.
An antifoaming agent, a leveling agent, and a preservative are added to the obtained aqueous composite resin composition for pressure-sensitive adhesive, and further adjusted to pH = 7.5 to 8 with aqueous ammonia, and Arakawa Chemical is used as a rosin-based tackifying resin. "Superester E-720" (solid content 50%) manufactured by Co., Ltd. was added as 20 parts as a solid content and 0.1 part of a 6% adipic acid dihydrazide aqueous solution as a solid content was added as a solid content. Adjusted to s (BL type viscometer, using # 4 rotor, measured at 60 rpm) to obtain an aqueous pressure-sensitive adhesive composition. This was coated on a release paper with a comma coater so that the dry coating amount was 20 g / m ² , dried in a drying oven at 100 ° C. for 40 seconds, laminated with a PET film having a thickness of 50 μm, wound up, and adhered. An agent coating was obtained.

(Example-2)
Except for using 3.33 parts of polyolefin aqueous dispersion “S-6008” (solid content 30%) manufactured by Nippon Paper Chemicals Co., Ltd. instead of the aqueous polyolefin (I) used in Example 1. Were the same as in Example 1 to obtain a composite resin composition aqueous dispersion for pressure-sensitive adhesive and a pressure-sensitive adhesive coated product.

(Example-3)
Implemented except that 6.67 parts of an aqueous polyolefin dispersion “S-6007” (solid content 30%) manufactured by Nippon Paper Chemicals Co., Ltd. was used in place of “S-6008” used in Example-2. In the same manner as in Example 2, an aqueous composite resin composition dispersion for pressure-sensitive adhesive and a pressure-sensitive adhesive coated product were obtained.

(Example-4)
9 parts of 2-ethylhexyl acrylate, 5 parts of methyl methacrylate, 1 part of acrylic acid, 0.2 part of diacetone acrylamide, 2 parts of "Aqualon KH-10" with respect to 100 parts of these all ethylenically unsaturated monomers What was melt | dissolved in 30.2 parts of deionized water was added and stirred and emulsified, the emulsion was obtained, and it put into the dropping funnel.
Four-necked flask equipped with a stirrer, a condenser, a thermometer, and the above dropping funnel, 43.9 parts deionized water, 0.1 part Aqualon KH-10, polyolefin aqueous solution obtained in Production Example-1 Dispersing 3.33 parts of Dispersion (I), replacing the inside of the flask with nitrogen gas, raising the internal temperature to 80 ° C. with stirring, and adding 0.15 part of a 3% aqueous potassium persulfate solution as a solid content. . After 5 minutes, dropping of the emulsion was started from the dropping funnel, and in parallel with this, 0.45 part of 3% potassium persulfate aqueous solution was added dropwise over 3 hours. Thereafter, a composite resin composition aqueous dispersion for pressure-sensitive adhesive having a solid content of 51% was obtained in the same manner as in Example 1, and a pressure-sensitive adhesive coated product was obtained in the same manner as in Example 1.

(Example-5)
94.8 parts butyl acrylate, 4 parts methyl methacrylate, 1 part acrylic acid, 0.2 part diacetone acrylamide, 2 parts "Aqualon KH-10" deionized to 100 parts of these all ethylenically unsaturated monomers What was dissolved in 30.2 parts of water was added and stirred to emulsify, and 6.67 parts of the polyolefin aqueous dispersion (I) obtained in Production Example-1 was further added and mixed to obtain an emulsion. It was. Thereafter, a composite resin composition aqueous dispersion for pressure-sensitive adhesive having a solid content of 51% was obtained in the same manner as in Example 1, and a pressure-sensitive adhesive coated product was obtained in the same manner as in Example 1.

(Example-6)
Instead of the aqueous polyophine dispersion (I) used in Example-5, 3.33 parts of an aqueous polyolefin dispersion “S-6008” (solid content 30%) manufactured by Nippon Paper Chemicals Co., Ltd. was used. A composite resin composition aqueous dispersion for pressure-sensitive adhesive and a pressure-sensitive adhesive coated material were obtained in the same manner as in Example-5.

(Comparative Example-1)
Resin composition for pressure-sensitive adhesives in the same manner as in Example 1 except that 3.33 parts of the polyolefin aqueous dispersion (I) obtained in Production Example-1 was not added when obtaining the emulsion to be put into the dropping funnel. An aqueous dispersion and a coated adhesive were obtained.

(Comparative Example-2)
To the aqueous resin composition dispersion for pressure-sensitive adhesive obtained in Comparative Example-1, 3.33 parts of the polyolefin aqueous dispersion (I) obtained in Production Example-1 was added and mixed, and the antifoaming agent and leveling were further mixed. An adhesive and an antiseptic were added, and thereafter a pressure-sensitive adhesive coated product was obtained in the same manner as in Comparative Example-1.

(Comparative Example-3)
66.7 parts of the polyolefin aqueous dispersion (I) obtained in Production Example-1 is added to and mixed with the aqueous resin composition for pressure-sensitive adhesive obtained in Comparative Example-1, and the antifoaming agent and leveling are further mixed. An adhesive and an antiseptic were added, and thereafter a pressure-sensitive adhesive coated product was obtained in the same manner as in Comparative Example-1.

(Comparative Example-4)
93.8 parts of 2-ethylhexyl acrylate, 5 parts of methyl methacrylate, 1 part of acrylic acid, and 0.2 part of diacetone acrylamide were mixed and dissolved, and further modified polyolefin resin “Auroren 150S” manufactured by Nippon Paper Chemicals Co., Ltd. When 1 part of (solid pellet resin having a solid content of 100%) was added and mixed and dissolved, it was swollen and could not be dissolved.

[Test method]
1) Adhesive strength measurement The pressure-sensitive adhesive coated product was cut into a 25 mm wide strip, the release paper was peeled off, and the adhesive was applied to a 2 mm thick polyethylene plate and a polypropylene plate. The adhesive strength was measured after being left under three conditions of 24 hours under, 10 days under a 23 ° C. atmosphere, and 10 days under a 90 ° C. atmosphere. In addition, about the sample left to stand in 90 degreeC atmosphere, it used for the measurement, after standing to cool to 23 degreeC after progress for a predetermined period. In addition, the adhesive strength was measured when peeled in the direction of 180 ° at a speed of 300 mm / min in an atmosphere of 23 ° C.

2) Cohesive force measurement The cohesive force was evaluated by the following holding force test, which is commonly used for performance evaluation of pressure-sensitive adhesives.
In the holding power test, the adhesive-coated product was cut into a strip of 25 mm width, the release paper was peeled off, and applied to the end in the longitudinal direction of a 3 cm x 11 cm polished stainless steel plate with an area of 25 mm x 25 mm. After one reciprocation with a roll, a 1 kg load is applied to the coated material in an atmosphere of 40 ° C. to generate a shear stress on the adhesive surface, left for a maximum of 70,000 seconds, and a time until dropping or a pasting position after 70,000 seconds have elapsed The distance of the deviation was measured.

3) Measurement of water whitening resistance The release paper of the pressure-sensitive adhesive coated product was peeled off, laminated with a PET film on which both sides were vapor-deposited with aluminum, immersed in water, and left in a 60 ° C. atmosphere for 72 hours. After the elapse of a predetermined time, the whiteness of the film was evaluated by wiping off water and using a spectrocolorimeter and measuring the L value of the surface on the side where the pressure-sensitive adhesive layer exists by a reflection method.

Table 1 shows the test results of adhesive strength, holding power, and water whitening resistance using each pressure-sensitive adhesive coated product.

As shown in Comparative Example 1, if no aqueous dispersion of polyolefins (B) is used, the adhesion to the polyolefin adherend is insufficient and the holding power is also insufficient. As shown in Comparative Example 2, when a small amount of the aqueous dispersion of polyolefins (B) was added in a small amount, the adhesive force to the polyolefin adherend was somewhat improved as compared with Comparative Example 1, but the holding power was still It is insufficient. Furthermore, as shown in Comparative Example 3, when the amount of the polyolefin (B) aqueous dispersion added is 20 times that in Comparative Example 2, the adhesion to the polyolefin adherend is improved to Example 1 level. Not only does the water resistance deteriorate significantly, but the holding power is still equivalent to Comparative Example 1 and is insufficient.
On the other hand, as shown in Example 1, the composite resin of the present invention obtained by polymerizing an ethylenically unsaturated monomer (A) in the presence of a very small amount of an aqueous dispersion of polyolefins (B). In the case of the composition, the adhesive strength to the polyolefin adherend is remarkably improved and the cohesive strength is also improved without lowering the water resistance. Also from this, unlike the case where the aqueous dispersion of polyolefins (B) as in Comparative Examples 2 and 3 is simply added and mixed, in the present invention, the heavy oil derived from the ethylenically unsaturated monomer (A) is used. It is considered that the coalesced portion and the aqueous dispersion (B) of polyolefins are combined.

Claims (5)

Adhesive obtained by polymerizing an ethylenically unsaturated monomer (A) capable of radical polymerization in an aqueous medium containing polyolefin (B) as an aqueous dispersion, a surfactant, a polymerization initiator and water as essential components Composite resin composition aqueous dispersion for use. The pressure-sensitive adhesive according to claim 1, wherein the radically polymerizable ethylenically unsaturated monomer (A) / polyolefins (B) = 99.95 / 0.05 to 90/10 (weight ratio). Composite resin composition aqueous dispersion for use. An aqueous pressure-sensitive adhesive composition comprising the aqueous dispersion of the composite resin composition according to claim 1. It is characterized by polymerizing an ethylenically unsaturated monomer (A) capable of radical polymerization in an aqueous medium containing an aqueous dispersion of polyolefins (B), a surfactant, a polymerization initiator and water as essential components. A method for producing an aqueous dispersion of a composite resin composition for pressure-sensitive adhesives. The pressure-sensitive adhesive according to claim 4, wherein the radically polymerizable ethylenically unsaturated monomer (A) / polyolefins (B) = 99.95 / 0.05 to 90/10 (weight ratio). For producing a composite resin composition aqueous dispersion for use.