JP2003165815A - Method for producing aqueous resin dispersion and pressure-sensitive adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aqueous resin dispersion, capable of stably conducting emulsion copolymerization to give the dispersion excellent in water resistance and adhesion, and to provide a pressure-sensitive adhesive composition containing the aqueous resin dispersion. <P>SOLUTION: This method for producing the aqueous resin dispersion comprises emulsifying and dispersing a macro monomer (A) and a vinyl monomer (B) in an aqueous medium in the presence of an emulsifier to prepare an aqueous emulsified dispersion having an average particle diameter of dispersoids of 1 μm, and then conducting emulsion polymerization of the macro monomer (A) and the vinyl monomer (B) by using the aqueous emulsified dispersion, wherein the macro monomer (A) is obtained by polymerizing a vinyl monomer mixture at a reaction temperature of 130-350°C, has an ethylenic unsaturated bond expressed by the formula: -CH<SB>2</SB>-C(X)=CH<SB>2</SB>(X is -COOR, -CONR<SB>2</SB>, -OR or the like; and R is an alkyl, a hydroxyalkyl or the like) at its end, and has a solubility in water of ≤10 wt.% at 25°C. The pressure-sensitive adhesive composition contains the aqueous resin dispersion obtained by the method. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aqueous resin dispersion and a pressure-sensitive adhesive composition. More specifically, it is capable of stably performing emulsion copolymerization, and has excellent water resistance and pressure-sensitive adhesiveness. The present invention relates to a method for producing an aqueous resin dispersion capable of obtaining a coalescence, and a pressure-sensitive adhesive composition containing the aqueous resin dispersion and having excellent water resistance and adhesiveness.

[0002]

2. Description of the Related Art Conventionally, a method of polymerizing a macromonomer and a vinyl monomer in an aqueous medium, and an aqueous pressure-sensitive adhesive composition containing a polymer obtained by such a method are known. For example, Japanese Patent No. 2897846 discloses an aqueous polymerization method in which a macromonomer produced in the presence of a cobalt chelate catalyst and a vinyl monomer are copolymerized.

However, this polymerization method has a problem in that the monomer that substantially constitutes the macromonomer is limited to methacrylate, and that the macromonomer unit consisting only of methacrylate causes a decrease in heat resistance. Further, since the macromonomer acts as a chain transfer agent during the polymerization reaction with the vinyl monomer, the macromonomer has a relatively low molecular weight, and the use of the macromonomer is limited. The function of the resin dispersion is also limited. Further, in this method, although a metal compound such as cobalt is used as a chain transfer agent, since such a metal compound is easily colored, there is a concern that the obtained polymer is colored or discolored, and in order to prevent it, A step of removing the metal compound from the obtained polymer is required.

Further, Japanese Unexamined Patent Publication No. 2000-80288 discloses an aqueous dispersion obtained by emulsion polymerization of a macromonomer obtained by thermal polymerization, using acrylic acid as an essential component, and International Publication WO01 / 041
No. 63 discloses that a macromonomer obtained by continuously polymerizing a mixture of a hydrophobic monomer and a monomer containing a carboxyl group in an amount of 10 to 75 mol% at high temperature is neutralized. Disclosed is a method for producing an aqueous resin dispersion, which comprises emulsion-polymerizing a vinyl monomer in an aqueous solvent, using as an emulsifier. However, the above-mentioned JP 2000-8
The macromonomer described in the method described in Japanese Patent No. 0288 is mainly composed of a monomer unit having a carboxyl group and may have insufficient water resistance. Also,
The macromonomer obtained by the method described in WO 01/04163 may have insufficient water resistance depending on the use conditions.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to stably perform emulsion copolymerization and obtain a polymer having excellent water resistance and tackiness. An object of the present invention is to provide a method for producing an aqueous resin dispersion, and an adhesive composition containing the aqueous resin dispersion and having excellent water resistance and adhesiveness.

[0006]

The method for producing an aqueous resin dispersion according to the present invention has an ethylenically unsaturated bond at the terminal, and
Method for producing an aqueous resin dispersion, which comprises emulsion-polymerizing a macromonomer (A) having a solubility in water at 5 ° C. of 10% by mass or less and a vinyl monomer (B) in an aqueous medium in the presence of an emulsifier. The macromonomer (A) is obtained by polymerizing a mixture of vinyl monomers at a reaction temperature of 130 to 350 ° C., and the ethylenically unsaturated bond has the following formula (1). It is characterized by the structure of. During _{-CH 2 -C (X) = CH} 2 (1) ( the equation (1), X is -COOR, -CONR _2, -
OR, -OCOR, -OCOOR, -NCOOR, halogen atom, -CN, or a phenyl group or an aryl group which may have a substituent, and R is an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or the like. Is an optionally substituted alkyl group, a phenyl group, a benzyl group, a polyalkylene glycol group, a dialkylaminoalkyl group, a trialkoxysilylalkyl group, or a hydrogen atom. )

The method for producing an aqueous resin dispersion of the present invention comprises emulsifying and dispersing a mixed solution of the macromonomer (A) and the vinyl monomer (B) in an aqueous medium in the presence of an emulsifier. By preparing an aqueous emulsion dispersion having an average particle size of dispersoid of 1 μm or less, and then polymerizing the macromonomer (A) and the vinyl monomer (B) using the aqueous emulsion dispersion. It can be carried out. Further, the method for producing an aqueous resin dispersion of the present invention comprises the step of adding the vinyl monomer in an aqueous emulsion dispersion of a macromonomer obtained by emulsifying and dispersing the macromonomer (A) in an aqueous medium in the presence of an emulsifier. It can be carried out by adding the body (B) and polymerizing.

The pressure-sensitive adhesive composition of the present invention is characterized by containing the aqueous resin dispersion obtained by the method for producing an aqueous resin dispersion of the present invention.

[0009]

According to the method for producing an aqueous resin dispersion of the present invention, a hydrophobic macromonomer having a predetermined structure, which is obtained by polymerizing at a predetermined reaction temperature as a macromonomer, is used, and an emulsifier is present. By emulsion polymerization under an aqueous medium, emulsion copolymerization with other vinyl monomers can be stably carried out. Further, according to the pressure-sensitive adhesive composition of the present invention, it is excellent in water resistance and adhesiveness,
It can be suitably used in various applications and ranges as compared with conventional pressure-sensitive adhesive compositions.

[0010]

The present invention will be described in more detail below. (1) Macromonomer (A) The macromonomer (A) in the method for producing an aqueous resin dispersion of the present invention has an ethylenically unsaturated bond represented by the following formula (1) at the terminal. In the following formula (1), X is -COO.
_{R, -CONR 2, -OR, -OCOR} , -OCOO
R, -NCOOR, halogen atom (fluoro, chloro,
Bromo or iodo), -CN, or a phenyl group which may have a substituent or an allyl group, wherein R may have an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group, or another substituent. A good alkyl group, phenyl group, benzyl group, polyalkylene glycol group, dialkylaminoalkyl group, trialkoxysilylalkyl group, or hydrogen atom. In addition, when the above R is plural,
Each R may be the same or different. Also,
Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an n-butyl group and an isobutyl group. _{-CH 2 -C (X) = CH} 2 (1)

Macromonomers having a methacryloyl group different from the structure represented by the above formula (1) at the end have been widely known, and the macromonomers and vinyl monomers are copolymerized in an aqueous medium. The resulting aqueous resin dispersion is also known. However, since this macromonomer is usually produced using a chain transfer agent having a sulfur atom, the resulting aqueous resin dispersion is likely to be colored or discolored, and weather resistance or heat resistance may be insufficient. Therefore, there is a problem that use is limited. On the other hand, the macromonomer (A) of the present invention is preferable because it has the ethylenically unsaturated bond represented by the above formula (1) at the terminal and thus the above problems can be avoided.

In the macromonomer (A), the ethylenically unsaturated bond may be contained at both ends of the macromonomer (A) or may be contained only at one end. Further, the macromonomer (A) is preferably one in which the ethylenically unsaturated bond is introduced into all macromonomers by polymerization, but a macromonomer in which the ethylenically unsaturated bond is not introduced is partially introduced. It may be a composition containing the same. The introduction ratio of the ethylenically unsaturated bond in the macromonomer composition is measured by gel permeation chromatography (hereinafter, referred to as “GPC”) using the tetrahydrofuran solvent of the macromonomer (A) of the present invention as polystyrene conversion. The number-average molecular weight and the weight-average molecular weight in ¹ and the terminal ethylenically unsaturated bond introduction ratio calculated from the concentration of the terminal ethylenically unsaturated bond measured by ¹ H-NMR (hereinafter referred to as “F value”).
It has the same meaning as the macromonomer concentration in the macromonomer composition. ). In the present invention, the F value of the macromonomer (A) is usually 50 or more, preferably 6
0 or more, more preferably 70 or more, more preferably 80
That is all. When the content is in such a range, the tackiness of the pressure-sensitive adhesive composition containing the aqueous resin dispersion obtained according to the present invention can be improved, which is preferable.

The number average molecular weight in terms of polystyrene measured by GPC using a tetrahydrofuran solvent of the above macromonomer (A) of the present invention is preferably 500 to 5.
0000, more preferably 700 to 25,000, still more preferably 1,000 to 10,000, and the weight average molecular weight is preferably 1,000 to 100,000, more preferably 1,500 to 50,000, further preferably 2,000 to 20.
It is 000.

The macromonomer (A) in the method for producing an aqueous resin dispersion of the present invention is hydrophobic, and specifically, the solubility in water at 25 ° C. is 10% by mass or less,
It is preferably 5% by mass or less, more preferably 2% by mass or less. The aqueous resin dispersion obtained by emulsion polymerization with a vinyl monomer using the hydrophilic macromonomer having a solubility of more than 10% by mass may have poor water resistance of the coating film obtained by coating. Not preferable.

The kind of the vinyl monomer used as the raw material of the macromonomer (A) is not particularly limited as long as the macromonomer (A) included in the scope of the present invention can be obtained, and if necessary. Various ones can be used. Examples of the vinyl monomer include (meth)
Methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate,
Isobutyl (meth) acrylate, (meth) acrylic acid 2
-Ethylhexyl, stearyl (meth) acrylate,
Lauryl (meth) acrylate, decyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate,
Examples thereof include (meth) acrylic acid esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, (meth) acrylic acid, styrene, α-methylstyrene, vinyl acetate, acrylonitrile and the like. Moreover, these 1 type (s) or 2 or more types can be used.

The above-mentioned macromonomer (A) can be obtained by polymerizing a mixture of the above-mentioned vinyl monomers, and the reaction temperature in this polymerization is 130 to 350 ° C.
Preferably from 150 to 320 ° C, more preferably from 200 to
It is 300 ° C. If the reaction temperature is lower than 130 ° C, the F value becomes small, that is, the concentration of macromonomer in the macromonomer composition becomes small, which is not preferable. It is not preferable because it may happen.

When the macromonomer (A) is obtained by polymerizing a mixture of the above-mentioned vinyl monomers, there are no particular restrictions on the conditions other than the above reaction temperature, the polymerization method and the conditions during the polymerization, and if necessary. Various methods and conditions can be used. Usually, a radical polymerization initiator may be used, or a radical polymerization initiator may not be used depending on the type of vinyl monomer to be polymerized. Although batch polymerization, continuous polymerization, and semi-continuous polymerization are all possible, continuous polymerization is preferable because a highly pure macromonomer can be obtained with good productivity. In addition, a solvent may or may not be used in the polymerization reaction. When a solvent is used, the concentration of the solvent is 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less, based on the amount of the polymerization reaction liquid in the production of the macromonomer. It is preferable because the productivity of the macromonomer can be improved.

(2) Vinyl Monomer (B) The vinyl monomer (B) used in the present invention is not particularly limited as long as it can be polymerized with the above macromonomer (A), and it is generally emulsified. The vinyl monomer used for polymerization can be used. Examples of such a vinyl monomer (B) include those exemplified as the vinyl monomer that can be used for the production of the above macromonomer.

(3) Emulsion Polymerization The method for producing the aqueous resin dispersion of the present invention is carried out by emulsion polymerizing the above macromonomer (A) and vinyl monomer (B) in the presence of an emulsifier in an aqueous medium. Be seen. In the method for producing an aqueous resin dispersion of the present invention, the macromonomer (A) and the vinyl monomer (B) may be used alone or in combination of two or more. Also,
In the method for producing an aqueous resin dispersion of the present invention, the ratio of the macromonomer (A) and the vinyl monomer (B) can be various if necessary, but usually,
When the total amount of the solid content of the macromonomer (A) and the vinyl monomer (B) is 100 parts by mass, the macromonomer (A) has a solid content of 5 to 70 parts by mass, preferably 10 to 60 parts by mass. Parts, more preferably 15 to 50 parts by mass,
It is more preferably 15 to 45 parts by mass. When the content is within such a range, the tackiness and water resistance of the pressure-sensitive adhesive composition containing the aqueous resin dispersion of the present invention can be improved, which is preferable.

In the method for producing the aqueous resin dispersion of the present invention,
The operating method is not particularly limited as long as the macromonomer (A) and the vinyl monomer (B) can be emulsion-polymerized in an aqueous medium in the presence of an emulsifier. For example, in the method for producing an aqueous resin dispersion of the present invention, the macromonomer (A) and the vinyl monomer (B) may be simply added in the reactor to carry out the polymerization. The mixed solution of the vinyl monomer (B) is emulsified and dispersed in an aqueous medium in the presence of an emulsifier, and the average particle diameter of the dispersoid is 1 μm.
It is possible to prepare an aqueous emulsion dispersion having a particle size of m or less, preferably 0.5 μm or less, and then perform emulsion polymerization. The average particle size of the dispersoid can be measured with a particle size measuring device, and when the average particle size of the dispersoid is 1 μm or less,
The hydrophobic macromonomer (A) and the vinyl monomer can be copolymerized more stably, which is preferable.

Further, in the method for producing an aqueous resin dispersion of the present invention, the above-mentioned macromonomer (A) is emulsified and dispersed in an aqueous medium in the presence of an emulsifier to obtain an aqueous emulsion dispersion of the macromonomer. The vinyl monomer (B) may be added for polymerization. On the contrary, the macromonomer (A) is added to an aqueous emulsion of the vinyl monomer (B) obtained by emulsifying and dispersing the vinyl monomer (B) in an aqueous medium in the presence of an emulsifier. You may add and polymerize.
In the method for producing an aqueous resin dispersion of the present invention, the macromonomer (A) and vinyl monomer (B) may be added as an aqueous emulsion dispersion. In this case, the method for preparing the aqueous emulsified dispersion is not particularly limited, but usually, the above macromonomer (A) or vinyl monomer (B) is added in the presence of an emulsifier and the emulsion is dispersed using a homogenizer or the like. It is prepared by

Examples of the emulsifier used in the method for producing the aqueous resin dispersion of the present invention include known anionic surfactants, nonionic surfactants, reactive anionic surfactants and reactive nonionic surfactants. Activators and the like can be used.

In the method for producing an aqueous resin dispersion of the present invention, the reaction conditions for emulsion polymerization are not particularly limited as long as the macromonomer (A) and vinyl monomer (B) can be emulsion polymerized. For example, a radical polymerization initiator can be used in the polymerization, and examples of such a radical polymerization initiator include hydrogen peroxide, alkyl hydroperoxide, dialkyl peroxide, persulfuric acid, peracid, and azo initiator. Known radical polymerization initiators such as the above can be used. When such a radical polymerization initiator is used, its blending amount is usually 0.05 to
It is 10% by mass. Also, regarding the temperature of the polymerization reaction,
It can be carried out in various ranges as required.

Applications of the aqueous resin dispersion obtained by the method for producing an aqueous resin dispersion of the present invention include paints, coating agents, adhesives and adhesives. The pressure-sensitive adhesive composition of the present invention contains the aqueous resin dispersion obtained by the method for producing an aqueous resin dispersion of the present invention as an essential component, and the aqueous resin dispersion contained in the pressure-sensitive adhesive composition. The content of the solid content of the aqueous resin dispersion is usually 50 to 100 parts by mass, preferably 70 to 99.9 parts by mass, based on 100 parts by mass of the solid content of the pressure-sensitive adhesive composition. Also,
The pressure-sensitive adhesive composition of the present invention is preferably added with a tackifier, which is usually added to the pressure-sensitive adhesive composition, because the adhesive property is particularly excellent. Further, the pressure-sensitive adhesive composition of the present invention, if necessary, a viscosity modifier such as a thickener, a cross-linking agent, a preservative, an anticorrosive, a pigment, a plasticizer, a wetting agent,
A filler, an antifreezing agent, a high boiling point solvent, an antifoaming agent, etc. may be added.

[0025]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, in the following description, "part" means a mass part and "%" means the mass%. (1) Synthesis of macromonomer composition A pressure stirring tank type reactor having a capacity of 500 ml equipped with a heating device using hot oil was filled with ethyl 3-ethoxypropionate, and the temperature inside the reactor was set to 250 ° C. The pressure was set above the expected vapor pressure using a pressure regulator. Next, 50 parts of butyl acrylate (hereinafter referred to as "BA"), methyl methacrylate (hereinafter referred to as "MM")
"A". ) 50 parts and 0.1 part of di-t-butyl peroxide (hereinafter referred to as "DTBP") were weighed to prepare a monomer mixture solution, which was stored in a raw material tank. Then, while keeping the pressure inside the reactor constant, the monomer mixture liquid was continuously supplied from the raw material tank to the reactor. At this time, the feed rate was set so that the residence time of the monomer mixed liquid in the reactor was 12 minutes. In addition, the temperature inside the reactor was 2 during continuous supply of the container monomer mixture.
Maintained at 30 ± 2 ° C. Then, the reaction liquid corresponding to the supply amount of the above-mentioned monomer mixed liquid is continuously extracted from the outlet of the reactor, and the extracted reaction liquid is introduced into the thin-film evaporator so that the unreacted monomers in the reaction liquid, etc. The macromonomer composition A1 was obtained by removing the volatile component. In this synthesis example, 90 minutes after the start of the supply of the above-mentioned monomer mixture, the sampling of the macromonomer composition A1 was started from the outlet of the thin film evaporator, and the sampling was carried out for 60 minutes.

The macromonomer composition A2 was prepared in the same manner as in the method for producing the macromonomer composition A1 except that the kind and amount of the monomer and the temperature inside the reactor were changed as shown in Table 1. Obtained. Further, by adding ammonia water containing ammonia in the same amount as the acid value measured by the neutralization titration method of the obtained macromonomer composition A2 to neutralize the carboxyl group, the macromonomer composition A2
N (aqueous solution having a solid content of 30%) was obtained. In addition, in Table 1,
“CHA” is cyclohexyl acrylate,
"A" is acrylic acid.

Then, for the macromonomer compositions A1 and A2, GP using a tetrahydrofuran solvent was used.
The number average molecular weight in terms of polystyrene by C (hereinafter,
Also referred to as "Mn". ) And weight average molecular weight (hereinafter referred to as “M
Also called w. ) Was measured. Further, the concentration of the terminal ethylenically unsaturated bond was measured by ¹ H-NMR, and the concentration of the terminal ethylenically unsaturated bond and the number average molecular weight were used to determine F.
The value was calculated. Further, the solubilities of the macromonomer compositions A1 and A2 were measured as follows. That is, 65 parts of water was added to 35 parts of the macromonomer composition, the mixture was stirred overnight at 25 ° C., and then the mixed solution was allowed to stand to precipitate insoluble matter. After filtering the supernatant with a 200-mesh filter cloth, the solubility of the macromonomer composition in water was measured by measuring the solid content of the filtrate. The results are shown in Table 1 below.

[0028]

[Table 1]

(2) Preparation of Aqueous Resin Dispersion The macromonomer composition prepared in (1) above and the monomers shown in Table 2 were used, and the composition shown in Table 2 was used to prepare an example according to the method described below. Aqueous resin dispersions of 1 to 3 and Comparative Examples 1 to 3 were prepared.

<Examples 1 and 2> The above macromonomer composition A1 and BA, which is a monomer, were mixed at a ratio shown in Table 2, and the resulting monomer mixture was mixed with azobis, which is a polymerization initiator. 0.3 part of isobutyronitrile (hereinafter referred to as "AIBN") was dissolved. This is "Aqualon HS
-1025 "(a reactive emulsifier manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added to 85 parts of dissolved deionized water, and the mixture was stirred with a homomixer, and then an average particle size of 0. A 35 μm monomer emulsion was prepared. The particle size was measured using a laser diffraction / scattering particle size distribution analyzer LA-910 manufactured by Horiba, Ltd., with a dispersion time of 1 minute, ultrasonic dispersion of 1 minute, and waiting time of 0 minutes after dispersion. I went. The relative refractive index of the dispersoid to water was 1.08, and the volume-based median diameter was used as the particle diameter. Then, in a flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer, 18 parts of water and "AQUARON HS
-1025 "(1.5 parts) was charged, the temperature was raised to 80 ° C with stirring under a nitrogen stream, and the monomer emulsion was added dropwise over 3 hours. After the dropping was completed, the polymerization temperature was raised to 85 ° C. and the reaction was continued for 1 hour to obtain the aqueous resin dispersions of Examples 1 and 2.

<Example 3> The same procedure as in Example 1 was repeated except that the macromonomer composition A1 used in Example 1 was changed to the macromonomer composition A2.
A water-based resin dispersion of was obtained.

Comparative Example 1 A flask equipped with a stirrer, a reflux condenser, a dropping funnel, and a thermometer was charged with 60 parts of water and 3 parts of "Aqualon HS-1025", and the mixture was stirred under a nitrogen stream until the temperature reached 80 ° C. After heating, ammonium persulfate 0.5
Added parts. Then, after 5 minutes, the monomer mixture obtained by mixing the monomers shown in Table 2 at the ratio shown in Table 2 was added dropwise over 3 hours. After the dropping was completed, the polymerization temperature was raised to 90 ° C., 0.5 part of ammonium persulfate was added, and the reaction was continued for 1 hour to obtain an aqueous resin dispersion of Comparative Example 1.

<Comparative Example 2> An aqueous resin dispersion of Comparative Example 2 was obtained by the same procedure as in Comparative Example 1 except that the monomer mixture used in Comparative Example 1 was changed to the composition shown in Table 2. It was

<Comparative Example 3> 0.3 part of AIBN as a polymerization initiator is dissolved in 80 parts of BA as a monomer, and the solubility in water at 25 ° C. is 30% by mass or more. (Solid content 67 parts). This was added to 20 parts of deionized water in which 3.0 parts of "Aqualon HS-1025" was dissolved, and after stirring with a homomixer,
A homogenizer was used to prepare a monomer emulsion having a particle size of 1 μm. And a stirrer, reflux condenser,
A flask equipped with a dropping funnel and a thermometer was charged with 20 parts of water and 1.5 parts of "Aqualon HS-1025", heated to 80 ° C under stirring under a nitrogen stream, and then the monomer emulsion was taken for 3 hours. Was dropped. After completion of the dropping, the polymerization temperature was raised to 85 ° C. and the reaction was continued for 1 hour to obtain an aqueous resin dispersion of Comparative Example 3.

(3) Performance Evaluation The following Examples 1 to 3 and Comparative Examples 1 to 3 were carried out by the following method.
The performance of each of the aqueous resin dispersions was evaluated. The results are shown in Table 2 below. Measurement of Adhesive Strength After coating each aqueous resin dispersion of Examples 1 to 3 and Comparative Examples 1 to 3 on a PET film, it was dried at 100 ° C. for 2 minutes to prepare an adhesive sheet having a coating thickness of 25 μm. . Then, this pressure-sensitive adhesive sheet was cut into a test piece having a width of 25 mm and a length of about 250 mm.
After leaving it in an atmosphere of ℃ and humidity of 65% for 24 hours,
The adhesive strength was measured according to the 180-degree peeling method specified in SZ0237. That is, temperature 23 ℃, humidity 65%
Under the conditions described above, the test piece was attached to a stainless steel plate or a polyethylene plate, and a 2 kg rubber roller was reciprocally pressed on the test piece. 300 mm after 30 minutes of crimping
The 180 ° C. peel adhesion strength to the test plate was measured at a pulling rate of 1 / min. Ball tack measurement Using the pressure-sensitive adhesive sheet obtained above, JIS Z
The ball tack was measured according to the ball rolling method specified in 0237. Water resistance Water resistance was evaluated by immersing the pressure-sensitive adhesive sheet obtained above in water at room temperature and measuring the time required for the coating film to whiten. The evaluation results are shown in the following three stages. ◯: No bleaching for one day or more. △: 30 minutes or more until whitening
×: whitening within 30 minutes

[0036]

[Table 2]

(4) Effects of Examples From Table 2, the pressure-sensitive adhesive compositions of Examples 1 to 3 using the macromonomer compositions A1 and A2 obtained by the production method of the present invention are all water resistant. Excellent, ball tack of 4 or more, SUS adhesion of 720 g / 2.
It is 5 cm or more, and the adhesiveness to PE is 50 or more, which shows that it has excellent adhesiveness. Further, in comparison with the pressure-sensitive adhesive composition of Comparative Example 3 using the macromonomer composition A2N obtained by neutralizing the macromonomer composition A2 with ammonia,
It can be seen that the pressure-sensitive adhesive composition of Example 3 has high water resistance and excellent adhesiveness.

On the other hand, as shown in Table 2, each of the pressure-sensitive adhesive compositions of Comparative Examples 1 and 2 containing no macromonomer obtained by the production method of the present invention was inferior to Examples 1 to 3 in water resistance. I know there is.

(5) Preparation of Other Aqueous Resin Dispersion A pressure type stirred tank reactor having a capacity of 300 ml equipped with an electric heater was filled with ethyl 3-ethoxy-propionate, and the temperature inside the reactor was set to 265 ° C. The reactor pressure was then set above the vapor pressure of ethyl 3-ethoxy-propionate using a pressure regulator. Next, 80 parts of BA, 20 parts of acrylic acid (AA), and 0.08 part of di-t-butyl peroxide were weighed to prepare a monomer mixture solution, which was stored in the raw material tank. Then, while keeping the pressure inside the reactor constant, the monomer mixture liquid was continuously supplied from the raw material tank to the reactor. At this time, the feed rate was set so that the residence time of the mixed monomer solution in the reactor was 12 minutes. Further, the temperature inside the reactor was maintained at 288 to 300 ° C. during the continuous supply of the monomer mixed liquid. Then, a reaction liquid corresponding to the supply amount of the above-mentioned monomer mixed liquid was continuously withdrawn from the outlet of the reactor. 90 minutes after the start of feeding, the collection of the reaction liquid was started from the outlet of the reactor. Then, the unreacted monomer in the reaction solution reaction solution collected by using a thin film evaporator was removed to obtain a macromonomer composition A3.

Regarding the above macromonomer composition A3,
The Mw, Mn, F value and the solubility in water at 25 ° C. were measured by the same method as in the above macromonomer compositions A1 and A2. As a result, Mw was 2620 and Mn was 139.
0, F value is 96%, solubility in water at 25 ° C is 1%
It was below. Moreover, when the ratio of the above-mentioned macromonomer composition A3 having a double bond at the terminal (the ratio of the terminal double bond) was measured using ¹ H-NMR, 80% of all the macromonomer molecules had a double bond. It was found that was introduced. Furthermore, the acid value of the macromonomer composition A3 was 2.3 meq / g.

Example 4 The above macromonomer composition A3 and sodium lauryl sulfate (SL) as an emulsifier were added to water.
S) Aqueous solution (30%) was added. The proportion of each component in the solution is 30% by mass of the macromonomer composition A3, and SLS (30%), when the total amount is 100% by mass.
Is 1% by mass. Then, by emulsifying and dispersing the macromonomer composition A3 in water using a homogenizer, a macromonomer composition A3 emulsion dispersion (concentration of the macromonomer composition A3; 30%, particle diameter; 6
67 nm) was prepared.

Next, 60 parts of water was charged into the polymerization flask,
1.9 parts of an SLS aqueous solution (30%) as an emulsifier was dissolved in this, 60 parts of the macromonomer composition A3 emulsion dispersion was further added, stirring was started, and the temperature was adjusted to 84 to 86 ° C. After adjusting the temperature, a solution prepared by dissolving 0.7 parts of ammonium persulfate (APS) in 4.7 parts of water as an initial catalyst was added. Next, 54 parts of styrene (ST), 18 parts of CHA, 8 parts of BA and 20 parts of methacrylic acid (MAA) were added to a solution prepared by dissolving 1.2 parts of an SLS aqueous solution (30%) as an emulsifier in 38 parts of water. The monomer emulsion was fed in 2 hours and 30 minutes.

The reaction solution after feeding was held for 30 minutes and then cooled to 75 ° C. After cooling, a solution of 0.1 part of tert-butyl hydroperoxide (TBHP) dissolved in 2.9 parts of water was added to the reaction solution as a touch 1 and subsequently 0.1 part of rongalit was dissolved in 6 parts of water. The solution was added. Then, 15 minutes later, the same operation as the touch 1 was performed as the touch 2. After 15 minutes from the completion of the addition of Touch 2, cooling was started to bring the reaction solution to 40 ° C. Once at 40 ° C, 15 parts water to 2.8 parts ammonium bicarbonate, 25 parts
% Zinc aqueous solution 4 parts and zinc oxide 2.3 parts were added to prepare a zinc cross-linking solution, which was added to the reaction solution over 15 minutes. This gives the aqueous resin dispersion (emulsion) of Example 4.
Got

The obtained aqueous resin dispersion (emulsion) of Example 4 had a solid content of 38.4%, a pH of 7.7 and a viscosity of 1.
The particle size was 1.7 mPas and the particle size was 82 nm. Moreover, when this emulsion was filtered through a 100-mesh sieve,
The gel content was 0 mg / L. Furthermore, in Example 4, a sample of the reaction system was taken with time to trace the particle shape, and the results shown in Table 3 below were obtained. Since the macromonomer composition A3 does not polymerize alone, the particle size (particle size; 667 nm) of the macromonomer composition A3 at the time of charging in the polymerization flask is consumed by the copolymerization reaction with the vinyl monomer. You can see that it is getting smaller.

[0045]

[Table 3]

Example 5 The above macromonomer composition A3 and an SLS aqueous solution (30%) as an emulsifier were added to water. The proportion of each component in the solution is 30% by mass when the total amount is 100% by mass and the macromonomer composition A3 is
And the SLS aqueous solution is 1.5% by mass. And
The macromonomer composition A3 was emulsified and dispersed in water using a homogenizer to prepare an emulsion dispersion of the macromonomer composition A3 (concentration of the macromonomer composition A3: 30%, particle diameter: 641 nm).

Next, 727 parts of water was charged into the polymerization flask, the temperature was adjusted to 85 to 87 ° C., and then 60 parts of the above macromonomer composition A3 emulsion dispersion was added. Then, 1 minute after the addition, sodium persulfate (S
A solution prepared by dissolving 1.2 parts of PS) in 17 parts of water was added. Then, a monomer emulsion prepared by adding 3.5 parts of BA and 96.5 parts of MMA to a solution prepared by dissolving 0.4 parts of an SLS aqueous solution (30%) as an emulsifier in 58 parts of water was fed in 2 hours.

The reaction solution after feeding was heated to 85 to 87 ° C. for 30 minutes.
After holding for a minute, it was cooled to 75 ° C. After cooling, as a touch 1 a solution of 1.3 parts of TBHP dissolved in 6.5 parts of water was added to the reaction solution, and subsequently a solution of 0.7 parts of Elbit N (sodium erythorbate) dissolved in 13 parts of water was added. did. Then, after 15 minutes, the same operation was performed. After 15 minutes from the end of the operation, the reaction solution was cooled to 40 ° C. As a result, an aqueous resin dispersion (emulsion) of Example 5 was obtained. The obtained aqueous resin dispersion (emulsion) of Example 5 had a solid content of 15.2%, a pH of 2.3, and a viscosity of 3.4 mP.
The particle size was as, and the particle size was 85 nm. Moreover, the produced gel was 0 mg / L. Furthermore, when a sample of the reaction system was taken over time to trace the particle shape in the same manner as in Example 4, the macromonomer composition A3 (particle diameter 641 nm) of the macromonomer composition A3 was obtained as in Example 4. The particle size became smaller as the polymerization with the vinyl monomer proceeded, and finally became a very small particle size.

Example 6 The above macromonomer composition A3 and an aqueous solution of sodium dodecylbenzenesulfonate (DBS) (20%) as an emulsifier were added to water. The proportion of each component in the solution is 100% by mass,
The macromonomer composition A3 is 30% by mass, and D
The BS aqueous solution (20%) is 1% by mass. Then, using a homogenizer, the above macromonomer composition A in water
3 was emulsified and dispersed to prepare a macromonomer composition A3 emulsion dispersion (concentration of the macromonomer composition A3: 30%, particle diameter: 1500 nm).

Next, the amount of water initially added to the polymerization flask was changed to 305 parts, the amount of the macromonomer composition A3 emulsion dispersion was changed to 33 parts, and the composition of the monomer emulsion was 54 parts of water and an emulsifier. DBS aqueous solution (20%) 0.6
Part, BA 3.3 parts, BMA 5.5 parts, MMA 90.1
Example 5, except that the MAA was changed to 1.1.
Polymerization was performed in the same manner as in. As a result, an aqueous resin dispersion (emulsion) of Example 6 was obtained. The resulting aqueous resin dispersion (emulsion) of Example 6 had a solid content of 20.
0%, pH 3.4, viscosity 4.5 mPas, particle size 299
was nm. Moreover, the produced gel was 0 mg / L. Further, when a sample of the reaction system was taken over time and its particle shape was traced in the same manner as in Example 4, the results shown in Table 4 below were obtained. From Table 4, it can be seen that the macromonomer composition A3 was almost absorbed by reaction when 80% of the monomer emulsion was fed.

[0051]

[Table 4]

Example 7 The above macromonomer composition A3 and an aqueous DBS solution (20%) as an emulsifier were added to water. The proportion of each component in the solution is 30% by mass when the total amount is 100% by mass and the macromonomer composition A3 is
And the DBS aqueous solution (20%) is 1% by mass. Then, by emulsifying and dispersing the macromonomer composition A3 in water using a homogenizer, an emulsion dispersion of the macromonomer composition A3 (concentration of the macromonomer composition A3; 30%, particle diameter; 745 nm) was prepared. .

Next, the amount of water initially added to the polymerization flask was changed to 654 parts, the amount of the macromonomer composition A3 emulsion dispersion was changed to 60 parts, and the composition of the monomer / emulsion was 58 parts of water and an emulsifier. DBS aqueous solution (20%) 1.8
Part, ALMA (allyl methacrylate) 0.8 part, ST
Polymerization was carried out in the same manner as in Example 5 except that the catalyst was changed to 99.2 parts, SPS 0.3 parts was dissolved in water to 13 parts, and cofeed was carried out together with the monomer emulsion (in this example, it was carried out). No initial catalyst was used.).
As a result, an aqueous resin dispersion (emulsion) of Example 7 was obtained. The obtained aqueous resin dispersion (emulsion) of Example 7 had a solid content of 11.4%, a pH of 2.5, and a viscosity of 2.
The particle size was 4 mPas and the particle size was 89 nm. In addition, the generated gel was as small as 83 mg / L. Furthermore, when a sample of the reaction system was taken over time and its particle shape was traced in the same manner as in Example 4, the results shown in Table 5 below were obtained.

[0054]

[Table 5]

Example 8 The above macromonomer composition A3 and an aqueous DBS solution (20%) as an emulsifier were added to water. The proportion of each component in the solution is 30% by mass when the total amount is 100% by mass and the macromonomer composition A3 is
And the DBS aqueous solution (20%) is 1% by mass. Then, the macromonomer composition A3 was emulsified and dispersed in water using a homogenizer to prepare an emulsion dispersion of the macromonomer composition A3 (concentration of the macromonomer composition A3: 30%, particle diameter: 850 nm). .

Next, 305 parts of water was charged into the polymerization flask, the temperature was raised to 85 ° C., and then 33 parts of the above macromonomer composition A3 emulsion dispersion was added. And addition 1
After a minute, a solution prepared by dissolving 1.2 parts of SPS in 17 parts of water was added as an initial catalyst. Thereafter, in 54 parts of water, 0.6 part of a DBS aqueous solution (20%) as an emulsifier, BA 8.8
Parts, 7.3 parts of the monomer emulsion prepared by adding 90.1 parts of MMA and 1.1 parts of MAA. Then, when the reaction started, the temperature rose, and became stable, the feed of the remaining monomer emulsion was immediately started. The feed time was 2 hours. Thereafter, the same operation as in Example 5 was performed to obtain an aqueous resin dispersion (emulsion) of Example 8. The obtained aqueous resin dispersion (emulsion) of Example 8 had a solid content of 20.5.
%, PH 2.1, viscosity 4.3 mPas, particle size 285 n
It was m. Moreover, the produced gel was 0 mg / L. Furthermore, in the same manner as in Example 4 above, when a sample of the reaction system was taken over time and its particle shape was traced, the results shown in Table 6 below were obtained. It should be noted from Table 6 that the particle size increases immediately after the start of feeding the monomer emulsion, which is considered to be because the macromonomer composition A3 temporarily swelled due to the added monomer emulsion.

[0057]

[Table 6]

Example 9 The macromonomer composition A3 and the DBS aqueous solution (20%) as an emulsifier were added to water. The proportion of each component in the solution is 30% by mass when the total amount is 100% by mass and the macromonomer composition A3 is
And the DBS aqueous solution is 1% by mass. Then, using a homogenizer, the above macromonomer composition A in water
3 was emulsified and dispersed to prepare an emulsified dispersion of the macromonomer composition A3 (concentration of the macromonomer composition A3; 30%, particle diameter; 761 nm).

Next, 360 parts of water was charged into the polymerization flask, the temperature was raised to 85 ° C., and then 33 parts of the above-mentioned macromonomer composition A3 emulsion dispersion was added. Then, a solution prepared by dissolving 1.2 parts of SPS in 17 parts of water was added as an initial catalyst. After that, instead of the monomer emulsion, the next monomer mix (BA 8.8 parts, MMA9
The feed of 0.1 part and a mixed solution of 1.1 parts of MAA) was started. Then, the subsequent operation was carried out in the same manner as in Example 5 above to obtain an aqueous resin dispersion of Example 9. The resulting aqueous resin dispersion (emulsion) of Example 9 had a solid content of 2
1.8%, pH 2.0, viscosity 3.8 mPas, particle size 3
It was 28 nm. In addition, the produced gel is 50 mg / L
And was very low. Further, when a sample of the reaction system was taken over time and its particle shape was traced in the same manner as in Example 4, the results shown in Table 7 below were obtained. From Table 7,
The aqueous resin dispersion of Example 9 had the same composition as that of Example 8, but the particle size was large due to the small amount of the emulsifier.

[0060]

[Table 7]

From the above, the above macromonomer composition A3
Is an anionic emulsifier DBS and S at a concentration of 10 to 40%.
LS is 0.5 to 0.5 with respect to the macromonomer composition A3.
Add 3.0%, homogenizer (pressure 35-55MP
By multiplying by a), it was possible to stably obtain an emulsion having a particle diameter of 500 to 1500 nm. In addition, by using this emulsion as a seed (using the emulsion by charging it into a reactor before the start of polymerization), an aqueous resin dispersion (copolymer emulsion) could be stably formed with ordinary monomers.

The present invention is not limited to the specific examples described above, and various modifications can be made according to the purpose and application.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Michihiro Kawai             1 Toagosei, 1 Funami-cho, Minato-ku, Nagoya-shi             Within the corporation (72) Inventor Toshiyoshi Watanabe             1 Toagosei, 1 Funami-cho, Minato-ku, Nagoya-shi             Within the corporation F-term (reference) 4J011 AA05 KA02 KA06 KA10 KA14                 4J027 AA08 BA05 BA07 CD09                 4J040 DN061 GA03 GA07 GA19                       JA03 LA06 LA07

Claims (4)

[Claims] 1. An ethylenically unsaturated bond at the terminal, 2
Method for producing an aqueous resin dispersion, which comprises emulsion-polymerizing a macromonomer (A) having a solubility in water at 5 ° C. of 10% by mass or less and a vinyl monomer (B) in an aqueous medium in the presence of an emulsifier. The macromonomer (A) is obtained by polymerizing a mixture of vinyl monomers at a reaction temperature of 130 to 350 ° C., and the ethylenically unsaturated bond has the following formula (1). 2. A method for producing an aqueous resin dispersion, which has the structure of During _{-CH 2 -C (X) = CH} 2 (1) ( the equation (1), X is -COOR, -CONR _2, -
OR, -OCOR, -OCOOR, -NCOOR, halogen atom, -CN, or a phenyl group or an aryl group which may have a substituent, and R is an alkyl group, a hydroxyalkyl group, an alkoxyalkyl group or the like. Is an optionally substituted alkyl group, a phenyl group, a benzyl group, a polyalkylene glycol group, a dialkylaminoalkyl group, a trialkoxysilylalkyl group, or a hydrogen atom. ) 2. An average particle diameter of the dispersoid is 1 μm or less by emulsifying and dispersing a mixed solution of the macromonomer (A) and the vinyl monomer (B) in an aqueous medium in the presence of an emulsifier. The method for producing an aqueous resin dispersion according to claim 1, wherein an aqueous emulsion dispersion is prepared, and then the macromonomer (A) and the vinyl monomer (B) are polymerized using the aqueous emulsion dispersion. 3. The vinyl monomer (B) is added to an aqueous emulsion of a macromonomer obtained by emulsifying and dispersing the macromonomer (A) in an aqueous medium in the presence of an emulsifier.
The method for producing an aqueous resin dispersion according to claim 1, wherein the polymerization is carried out by adding the compound. 4. A pressure-sensitive adhesive composition comprising the aqueous resin dispersion obtained by the method for producing an aqueous resin dispersion according to claim 1.