JP2019172845A - (meth)acrylic resin emulsion for primer layer formation - Google Patents

Abstract

To provide a (meth)acrylic resin emulsion for primer layer formation, that has an excellent miscibility with additives, and the primer layer formed has an excellent solvent resistance.SOLUTION: Provided is a resin emulsion comprising: a resin particle having a unit A derived from a (meth)acrylic monomer having a carboxy group and/or a hydroxyl group, a unit B derived from a methylol group-containing monomer, a unit C derived from an ethylenically unsaturated double bond and oxyethylene group-containing anionic type reactive surfactant, and a unit D derived from formula (1) oxyethylene group-containing nonionic type reactive surfactant, and having an average particle diameter of 10 nm to 100 nm; and an aqueous medium. [Y: a substituent represented by formula (2), m: an integer of 1 to 3, n: an integer of 8 to 100].SELECTED DRAWING: None

Description

  The present disclosure relates to a (meth) acrylic resin emulsion for forming a primer layer.

  A laminated body in which a plurality of optical films having different functions is laminated is used for an optical component such as a liquid crystal display or a touch panel. In general, an optical film has a configuration in which various functional layers are provided on a film substrate. For example, a primer layer may be provided to improve adhesion between the film substrate and various functional layers. is there. The primer layer is formed on at least one of the front surface and the back surface of the film substrate. A composition containing a (meth) acrylic resin emulsion is widely used for forming the primer layer.

As the (meth) acrylic resin emulsion used to form the primer layer, for example, the content of the structural unit derived from the carboxy group-containing monomer relative to the total structural unit, and the hydroxyl group-containing monomer relative to the total structural unit The total content A of the derived structural units is 8 mol% to 30 mol%, and the content B of the structural units derived from the methylol group-containing monomer with respect to all the structural units is 0.5 mol. A water-dispersed resin composition containing particles of (meth) acrylic polymer in an amount of from 5 to 5 mol%, a crosslinking agent, and an aqueous medium is known (for example, see Patent Document 1).
Further, core-shell type vinyl polymer particles (A) having a minimum film-forming temperature of 20 ° C. or lower are dispersed in an aqueous medium, and the vinyl polymer particles (A) have a glass transition temperature in the core portion. Optical film having an aromatic cyclic structure-containing vinyl polymer (AI) at 50 ° C to 150 ° C and a vinyl polymer (A-II) having a glass transition temperature of -20 ° C to 20 ° C in the shell portion 2. Description of the Related Art Surface coating agents for plastic films are known (see, for example, Patent Document 2).

JP-T-2017-179227 JP 2009-8902 A

  By the way, in recent years, attempts have been made to further improve the adhesion between the film substrate and the functional layer in accordance with changes in the composition, shape, and the like of the functional layer due to the higher functionality of the optical film. As a method for improving the adhesion between the film substrate and the functional layer, for example, when preparing a composition for forming a primer layer, various additives represented by metal salts, amine salts and the like are added. Can be considered. However, when an additive such as a metal salt or an amine salt is added to a composition containing a (meth) acrylic resin emulsion, the resin emulsion particles (hereinafter simply referred to as “resin particles”) and the additive aggregate. The transparency of the primer layer may be impaired due to the generated aggregates. If the transparency of the primer layer is impaired, the various functional layers cannot fully perform their functions. Therefore, the (meth) acrylic resin emulsion is required to have miscibility with additives such as metal salts and amine salts.

  Further, the transparency of the primer layer may be impaired by the action of an organic solvent used when various functional layers are provided on the film substrate. Therefore, solvent resistance is also required for the (meth) acrylic resin emulsion.

  The problem to be solved by the present invention is that a primer layer excellent in miscibility with various additives (for example, metal salts and amine salts) and excellent in transparency can be formed, and the formed primer layer is solvent resistant. It is to provide a (meth) acrylic resin emulsion for forming a primer layer which is excellent in.

Specific means for solving the above problems include the following modes.
<1> Structural unit (A) derived from a (meth) acrylic monomer having at least one functional group selected from a carboxy group and a hydroxyl group, a structural unit (B) derived from a monomer having a methylol group, The structural unit (C) derived from an anionic reactive surfactant having an ethylenically unsaturated double bond and an oxyethylene group, and the average added mole number of the oxyethylene group represented by the following formula (1): The anionic reactive surfactant has a structural unit (D) derived from a nonionic reactive surfactant that is larger than the average number of moles of oxyethylene groups added and has an average particle size of 10 nm to 100 nm. (Meth) acrylic resin emulsion for primer layer formation containing the resin particle | grains which are these, and an aqueous medium.

  In formula (1), Y represents a substituent represented by the following formula (2). m represents an integer of 1 to 3. n represents the average added mole number of an oxyethylene group and represents an integer of 8 to 100.

<2> The primer layer-forming (meth) acrylic resin emulsion according to <1>, wherein the anionic reactive surfactant is an anionic reactive surfactant represented by the following formula (3).

In formula (3), X represents —SO ₃ M, —COOM, or —PO ₃ M, and M represents an alkali metal atom, an alkaline earth metal atom, or an ammonium group. p represents an integer of 1 to 3. q represents the average addition mole number of an oxyethylene group, and represents the integer of 5-40.

<3> The primer layer-forming (meth) acrylic resin emulsion according to <1> or <2>, wherein the glass transition temperature of the resin is 0 ° C. or higher.
<4> The content of the structural unit derived from the monomer having an aromatic ring in the resin is a structural unit of the resin (provided that the reactive surface activity includes the structural unit (C) and the structural unit (D)). (Mex) acrylic resin emulsion for forming a primer layer according to any one of <1> to <3>, which is 20.0% by mass or less with respect to the total mass of the structural unit derived from the agent. .

  According to the present invention, a primer layer which is excellent in miscibility with various additives (for example, metal salts and amine salts), can form a primer layer having excellent transparency, and the formed primer layer has excellent solvent resistance. A forming (meth) acrylic resin emulsion is provided.

  Hereinafter, specific embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

In the present specification, a numerical range indicated using “to” means a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the numerical ranges described stepwise in the present specification, the upper limit value or lower limit value described in a numerical range may be replaced with the upper limit value or lower limit value of the numerical range described in another stepwise manner. . Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the values shown in the examples.
In the present specification, a combination of two or more preferred embodiments is a more preferred embodiment.
In the present specification, the amount of each component means the total amount of the plurality of types of substances unless there is a specific notice when there are a plurality of types of substances corresponding to each component.

  In the present specification, “(meth) acryl” is a term including both acrylic and methacrylic, “(meth) acrylate” is a term including both acrylate and methacrylate, and “(meth) acryloyl group” "Is a term that encompasses both acryloyl and methacryloyl groups.

In the present specification, the term “(meth) acrylic resin” means that the content of a structural unit derived from a monomer having a (meth) acryloyl group is a structural unit of a resin (provided that it is derived from a reactive surfactant). The resin is 50% by mass or more based on the total mass of the unit.
The “monomer” in the present specification does not include a reactive surfactant.

  In this specification, the term “process” is not limited to an independent process, and is included in this term if the intended purpose of the process is achieved even when it cannot be clearly distinguished from other processes. It is.

[(Meth) acrylic resin emulsion for primer layer formation]
The primer layer-forming (meth) acrylic resin emulsion of the present invention (hereinafter also simply referred to as “(meth) acrylic resin emulsion”) has (meth) acrylic having at least one functional group selected from a carboxy group and a hydroxyl group. A structural unit (A) derived from a monomer (hereinafter also referred to as “specific (meth) acrylic monomer”), a structural unit (B) derived from a monomer having a methylol group, an ethylenically unsaturated dimer; The structural unit (C) derived from an anionic reactive surfactant having a heavy bond and an oxyethylene group (hereinafter also referred to as “specific anionic reactive surfactant”), and represented by the formula (1) A nonionic reactive surfactant (hereinafter referred to as “nonionic reactive surfactant”) in which the average added mole number of oxyethylene group is larger than the average added mole number of oxyethylene group possessed by the anionic reactive surfactant. And resin particles having a structural unit (D) derived from “a specific nonionic reactive surfactant” and having an average particle diameter of 10 nm or more and 100 nm or less, and an aqueous medium. .
The (meth) acrylic resin emulsion of the present invention is used for forming a primer layer. In the (meth) acrylic resin emulsion of the present invention, the structural unit (A) derived from a specific (meth) acrylic monomer, the structural unit (B) derived from a monomer having a methylol group, a specific anionic reactive interface Resin particles having a structural unit (C) derived from an activator and a structural unit (D) derived from a specific nonionic reactive surfactant and having an average particle size of 10 nm to 100 nm are aqueous. It exists in a dispersed state in the medium.
The (meth) acrylic resin emulsion of the present invention can be suitably used as it is as a primer layer-forming coating solution or as a raw material for a primer layer-forming coating solution.

  In recent years, the need for further improving the adhesion between the film substrate and the functional layer has increased with the enhancement of the functionality of optical films. In order to improve the adhesion between the film substrate and the functional layer, for example, when preparing a composition for forming a primer layer, various additives typified by metal salts, amine salts and the like are added. Can be considered. However, when an additive such as a metal salt or an amine salt is added to the composition containing the (meth) acrylic resin emulsion, an agglomeration reaction may occur between the resin particles and the additive, and an aggregate may be generated. . When aggregates are generated, the transparency of the formed primer layer is impaired. Moreover, the transparency of the primer layer may be impaired by the action of an organic solvent used when various functional layers are provided on the film substrate. If the transparency of the primer layer is impaired, the various functional layers cannot sufficiently perform their functions.

In contrast, the (meth) acrylic resin emulsion of the present invention is excellent in miscibility with various additives (for example, metal salts and amine salts) and can form a primer layer excellent in transparency. Moreover, the primer layer formed using the (meth) acrylic resin emulsion of the present invention is excellent in solvent resistance.
The reason why the (meth) acrylic resin emulsion of the present invention can exhibit such an effect is not clear, but the present inventors presume as follows.

Since the (meth) acrylic resin emulsion of the present invention contains fine resin particles having an average particle size of 10 nm or more and 100 nm or less, the formed primer layer becomes a film in which resin particles are densely packed and is transparent. Excellent in properties.
In general, fine resin particles tend to aggregate in an aqueous medium. On the other hand, since the resin particles contained in the (meth) acrylic resin emulsion of the present invention have the structural unit (A) derived from the specific (meth) acrylic monomer, the specific (meth) acrylic simple substance is present in the aqueous medium. At least one of the carboxy group and hydroxyl group of the monomer is ionized, and the surface is negatively charged. When the surface of the resin particle is negatively charged, electrostatic repulsion occurs. Therefore, the resin particle contained in the (meth) acrylic resin emulsion of the present invention is fine but hardly aggregates.
The fine resin particles in the (meth) acrylic resin emulsion of the present invention can be realized by having a structural unit (C) derived from a specific anionic reactive surfactant. However, resin particles having a constitutional unit derived from an anionic reactive surfactant, an anionic reactive surfactant when a (meth) acrylic resin emulsion is used in combination with various additives (metal salt and amine salt) Are easily attracted to amine salts and the like, so that aggregates are easily formed. When aggregates are formed, a primer layer having excellent transparency cannot be formed. In contrast, in the (meth) acrylic resin emulsion of the present invention, the resin constituting the resin particles has a specific nonionic reactivity having an oxyethylene chain longer than the oxyethylene chain of the specific anionic reactive surfactant. Since it has the structural unit (D) derived from the surfactant, the agglutination reaction between the specific anionic reactive surfactant and an amine salt is caused by a physical obstacle due to the oxyethylene chain of the specific nonionic reactive surfactant. Is disturbed. Therefore, the (meth) acrylic resin emulsion of the present invention can realize the formation of a primer layer having excellent transparency even when used in combination with various additives (metal salts and amine salts). In addition, the specific nonionic reactive surfactant contains a highly reactive 1-propenyl group and is strongly chemically bonded to a monomer having a specific (meth) acrylic monomer and a methylol group. Can function stably and effectively.

  When forming a primer layer on a film base material, the (meth) acrylic resin emulsion coated on the film base material is preliminarily dried before the main drying. In the (meth) acrylic resin emulsion of the present invention, since the resin constituting the resin particles has a structural unit (B) derived from a monomer having a methylol group, condensation between the methylol groups during preliminary drying. By the reaction (so-called self-crosslinking reaction), the structural units (B) can form a crosslinked structure. When the structural units (B) form a crosslinked structure, the finally obtained primer layer becomes a dense film, and thus the solvent resistance is improved. When the solvent resistance of the primer layer is improved, the transparency of the primer layer is less likely to be impaired when various functional layers are provided on the film substrate.

For the (meth) acrylic resin emulsion of the present invention, the water-dispersed resin composition described in Patent Document 1 (Japanese Patent Publication No. 2017-179227) and the optical technique described in Patent Document 2 (Japanese Patent Application Laid-Open No. 2009-8902). The surface coating agent for plastic films for film does not pay attention to the problem of miscibility with various additives (metal salts and amine salts) and the solvent resistance of the formed film.
Further, in the water-dispersed resin composition described in Patent Document 1, since a non-reactive surfactant is included as a surfactant, the surfactant exists in a free state without forming resin particles in an aqueous medium. Will increase. When the non-surfactant is liberated in the aqueous medium, it becomes easy to form an aggregate with various additives (metal salt and amine salt)). Therefore, in the water-dispersed resin composition described in Patent Document 1, It is difficult to form a primer layer having excellent transparency.

  In addition, said guess does not limit the effect of the (meth) acrylic resin emulsion of this invention, and explains as an example.

  Hereinafter, each component of the (meth) acrylic resin emulsion of the present invention will be described.

[Resin particles]
The resin particles contained in the (meth) acrylic resin emulsion of the present invention are a structural unit (A) derived from a (meth) acrylic monomer having at least one functional group selected from a carboxy group and a hydroxyl group, and a methylol group. In the structural unit (B) derived from a monomer having a structural unit (C) derived from an anionic reactive surfactant having an ethylenically unsaturated double bond and an oxyethylene group, and in the formula (1) A structural unit (D) derived from a nonionic reactive surfactant, wherein the average added mole number of the oxyethylene group is greater than the average added mole number of the oxyethylene group of the anionic reactive surfactant. The average particle diameter is 10 nm or more and 100 nm or less.
First, the structural units of the resin constituting the resin particles will be described.

<Structural unit (A)>
The resin has a structural unit (A) derived from a (meth) acrylic monomer having at least one functional group selected from a carboxy group and a hydroxyl group (that is, a specific (meth) acrylic monomer).
In this specification, “a structural unit derived from a (meth) acrylic monomer having at least one functional group selected from a carboxy group and a hydroxyl group” means at least one functional group selected from a carboxy group and a hydroxyl group. It means a structural unit formed by addition polymerization of a (meth) acrylic monomer.

The structural unit (A) contributes to suppression of aggregation of resin particles in the aqueous medium.
When the resin has the structural unit (A), at least one of the carboxy group and the hydroxyl group is ionized in the aqueous medium, and the surface of the resin particle is negatively charged. When the surface of the resin particles is negatively charged, electrostatic repulsion occurs, and it is considered that aggregation of the resin particles is suppressed. Therefore, the (meth) acrylic resin emulsion of the present invention can form a primer layer having excellent transparency.

There is no restriction | limiting in particular as a kind of (meth) acryl monomer which has a carboxy group.
Specific examples of the (meth) acrylic monomer having a carboxy group include (meth) acrylic acid, ω-carboxy-polycaprolactone mono (meth) acrylate, 2- (meth) acryloyloxyethyl succinic acid, and the like.
Among these, as the (meth) acrylic monomer having a carboxy group, for example, from the viewpoint of excellent polymerization reactivity, methacrylic acid (MAA), acrylic acid (AA), and ω-carboxy-polycaprolactone mono At least one selected from the group consisting of acrylates is preferred.

There is no restriction | limiting in particular as a kind of (meth) acryl monomer which has a hydroxyl group.
Specific examples of the (meth) acrylic monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth). Acrylate, 6-hydroxyhexyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, 3-methyl-3-hydroxybutyl (meth) acrylate, 1,1-dimethyl-3- Hydroxybutyl (meth) acrylate, 1,3-dimethyl-3-hydroxybutyl (meth) acrylate, 2,2,4-trimethyl-3-hydroxypentyl (meth) acrylate, 2-ethyl-3-hydroxyhexyl (meth) Acrylate, glycerin Mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, polyethylene glycol mono (meth) acrylate, poly (ethylene glycol - propylene glycol) mono (meth) acrylate.
Among these, as the (meth) acrylic monomer having a hydroxyl group, 2-hydroxyethyl methacrylate (2HEMA) is preferable from the viewpoint of excellent polymerization reactivity, for example.

  The resin may have only one type of structural unit (A) or may have two or more types. The resin may have, for example, only a structural unit derived from a (meth) acrylic monomer having a carboxy group, or only a structural unit derived from a (meth) acrylic monomer having a hydroxyl group. It may have, and may have both the structural unit derived from the (meth) acryl monomer which has a carboxy group, and the structural unit derived from the (meth) acryl monomer which has a hydroxyl group.

The proportion of the structural unit (A) in the resin (that is, the content) is not particularly limited. For example, the reactive surfactant containing the structural unit of the resin (however, the structural unit (C) and the structural unit (D)) may be used. 0.1 mass% or more is preferable, 0.5 mass% or more is more preferable, and 1.0 mass% or more is still more preferable with respect to the total mass of derived structural units.
The content of the structural unit (A) in the resin is based on the total mass of the structural unit of the resin (excluding the structural unit derived from the reactive surfactant containing the structural unit (C) and the structural unit (D)). On the other hand, when the content is 0.1% by mass or more, aggregation of resin particles hardly occurs, and thus the production stability and storage stability of the (meth) acrylic resin emulsion tend to be further improved.
Moreover, the content rate of the structural unit (A) in resin is the structural unit of resin (However, the structural unit derived from the reactive surfactant containing a structural unit (C) and a structural unit (D) is remove | excluded.). Is preferably 20.0 mass% or less, more preferably 15.0 mass% or less, and still more preferably 10.0 mass% or less.
The content of the structural unit (A) in the resin is based on the total mass of the structural unit of the resin (excluding the structural unit derived from the reactive surfactant containing the structural unit (C) and the structural unit (D)). On the other hand, when the content is 20.0% by mass or less, since the polymerization reaction proceeds more uniformly in the aqueous medium, it is difficult to generate a lump insoluble matter, and the production stability of the (meth) acrylic resin emulsion is further improved. Tend.

<Structural unit (B)>
The resin has a structural unit (B) derived from a monomer having a methylol group.
In the present specification, the “structural unit derived from a monomer having a methylol group” means a structural unit formed by addition polymerization of a monomer having a methylol group.

A structural unit (B) contributes to the improvement of the solvent resistance of the primer layer formed.
Generally, when a primer layer is formed on a film substrate, the (meth) acrylic resin emulsion coated on the film substrate is pre-dried (also referred to as “pre-drying”) before the main drying. When the resin has the structural unit (B), the structural units (B) may form a crosslinked structure by condensation reaction between methylol groups (so-called self-crosslinking reaction) during preliminary drying. Since the primer layer finally obtained becomes a dense film by forming a crosslinked structure between the structural units (B), it is considered that the solvent resistance is improved.

There is no restriction | limiting in particular as a kind of monomer which has a methylol group.
Specific examples of the monomer having a methylol group include N-methylol acrylamide (NMAM), N-methylol methacrylamide, dimethylol acrylamide, dimethylol methacrylamide and the like.
Among these, as a monomer having a methylol group, for example, N-methylolacrylamide (NMAM) is preferable from the viewpoint of production stability in emulsion polymerization.

  The resin may have only one type of structural unit (B), or may have two or more types.

The proportion of the structural unit (B) in the resin (that is, the content) is not particularly limited. For example, the reactive surfactant containing the structural unit of the resin (however, the structural unit (C) and the structural unit (D)) 0.2 mass% or more is preferable, 0.5 mass% or more is more preferable, and 1.0 mass% or more is still more preferable with respect to the total mass of derived structural units.
The content of the structural unit (B) in the resin is based on the total mass of the structural unit of the resin (excluding the structural unit derived from the reactive surfactant containing the structural unit (C) and the structural unit (D)). On the other hand, when the content is 0.2% by mass or more, the primer layer to be formed becomes a denser film and tends to exhibit better solvent resistance.
Moreover, the content rate of the structural unit (B) in resin is a structural unit of resin (however, except the structural unit derived from the reactive surfactant containing a structural unit (C) and a structural unit (D)). Is preferably 10.0% by mass or less, more preferably 7.0% by mass or less, and still more preferably 5.0% by mass or less.
The content of the structural unit (B) in the resin is based on the total mass of the structural unit of the resin (excluding the structural unit derived from the reactive surfactant containing the structural unit (C) and the structural unit (D)). On the other hand, when the content is 10.0% by mass or less, enlargement of resin particles due to a decrease in production stability is favorably suppressed, and the formed primer layer tends to exhibit more excellent transparency.

<Constitutional unit derived from (meth) acrylic acid alkyl ester monomer>
The resin preferably has a structural unit derived from a (meth) acrylic acid alkyl ester monomer.
In the present specification, the “structural unit derived from a (meth) acrylic acid alkyl ester monomer” means a structural unit formed by addition polymerization of a (meth) acrylic acid alkyl ester monomer.
The structural unit derived from the (meth) acrylic acid alkyl ester monomer contributes to the adjustment of the glass transition temperature of the resin. Also, if the resin has a structural unit derived from a (meth) acrylic acid alkyl ester monomer, the occurrence of tack is better suppressed when the primer layer is formed, so that the blocking resistance of the primer layer, and The adhesion between the primer layer and the film tends to be further improved.

As a (meth) acrylic-acid alkylester monomer, an unsubstituted (meth) acrylic-acid alkylester monomer is preferable and the kind in particular is not restrict | limited.
The alkyl group of the (meth) acrylic acid alkyl ester monomer may be linear, branched or cyclic.
The number of carbon atoms of the alkyl group of the (meth) acrylic acid alkyl ester monomer is, for example, preferably in the range of 1-18, more preferably in the range of 1-15, from the viewpoint of adjusting the glass transition temperature of the resin. A range of 12 is more preferred.

Specific examples of the (meth) acrylic acid alkyl ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, and s-butyl (meth). Acrylate, t-butyl (meth) acrylate, n-octyl (meth) acrylate, i-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, i-nonyl (meth) acrylate, Examples include n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate.
Among these, (meth) acrylic acid alkyl ester monomers include, for example, n-butyl acrylate (n-BA), methyl methacrylate (MMA), ethyl acrylate (EA) from the viewpoint of adjusting the glass transition temperature of the resin. And at least one selected from the group consisting of 2-ethylhexyl acrylate (2EHA), a combination of n-butyl acrylate (n-BA) and methyl methacrylate (MMA), ethyl acrylate (EA) and methyl methacrylate ( A combination of MMA) or 2-ethylhexyl acrylate (2EHA) and methyl methacrylate (MMA) is more preferable, and a combination of n-butyl acrylate (n-BA) and methyl methacrylate (MMA) is more preferable.

  When the resin includes a structural unit derived from a (meth) acrylic acid alkyl ester monomer, the resin may have only one structural unit derived from a (meth) acrylic acid alkyl ester monomer. You may have more.

When the resin includes a structural unit derived from a (meth) acrylic acid alkyl ester monomer, the proportion of the structural unit derived from the (meth) acrylic acid alkyl ester monomer in the resin (that is, the content) is, for example, From the viewpoint of adjusting the glass transition temperature of the resin, the structural unit of the resin (excluding the structural unit derived from a reactive surfactant including an anionic reactive surfactant and a nonionic reactive surfactant). 70.0 mass% or more is preferable with respect to the total mass, 80.0 mass% or more is more preferable, and 85.0 mass% or more is still more preferable.
Further, the content of the structural unit derived from the (meth) acrylic acid alkyl ester monomer in the resin is, for example, from the viewpoint of adjusting the glass transition temperature of the resin, the resin structural unit (however, anionic reactive surface activity 99.9% by mass or less is preferable, and 99.0% by mass or less is more preferable, based on the total mass of the surfactant and the nonionic reactive surfactant. 98.0 mass% or less is still more preferable.

<Constitutional unit derived from monomer having aromatic ring>
The proportion of the structural unit derived from the monomer having an aromatic ring in the resin (that is, the content) is, for example, from the viewpoint of stretch resistance of the primer layer to be formed (however, the structural unit (C ) And a structural unit derived from a reactive surfactant containing the structural unit (D).) Is preferably 20.0% by mass or less, more preferably 10.0% by mass or less, and more preferably 5% by mass. 0.0 mass% or less is further preferable, and it is particularly preferable that the resin does not have a structural unit derived from a monomer having an aromatic ring.
For example, a film in which a primer layer is formed after a primer layer is formed by applying a (meth) acrylic resin emulsion containing resin particles having a structural unit derived from a monomer having an aromatic ring on the film When the is stretched, the primer layer may be whitened due to disorder of the orientation of the aromatic ring. The content of the structural unit derived from the monomer having an aromatic ring in the resin is derived from the structural unit of the resin (however, derived from a reactive surfactant including an anionic reactive surfactant and a nonionic reactive surfactant) When the content is 20.0% by mass or less with respect to the total mass of the primer layer, whitening of the primer layer due to disorder of the orientation of the aromatic ring is suppressed, so that the primer layer has excellent transparency. Hard to be damaged.
In addition, according to the aromatic ring contained in a structural unit (C) and a structural unit (D), the problem of whitening of a primer layer does not arise. The reason for this is considered to be that the presence of the oxyethylene group contained in the structural unit (C) and the structural unit (D) suppresses disturbance in the orientation of the aromatic ring due to stretching of the film.

The kind of aromatic ring is not particularly limited.
As an aromatic ring, a benzene ring is mentioned, for example.
Specific examples of the monomer having an aromatic ring include aromatic monovinyl (styrene, α-methylstyrene, t-butylstyrene, p-chlorostyrene, chloromethylstyrene, vinyltoluene, etc.), and various types of these monomers. Derivatives and the like.

<Constituent units derived from other monomers>
The resin is a structural unit derived from a monomer other than a specific (meth) acrylic monomer, a monomer having a methylol group, and a (meth) acrylic acid alkyl ester monomer (so-called “other monomer”). It may also be referred to as “a structural unit derived from”.
In the present specification, the “structural unit derived from other monomer” means a structural unit formed by addition polymerization of another monomer.

There is no restriction | limiting in particular as a kind of other monomer.
Specific examples of other monomers include vinyl esters (vinyl formate, vinyl acetate, vinyl propionate, vinyl versatate, etc.), various derivatives of these monomers, and the like.

  When the resin has a structural unit derived from another monomer, the resin may have only one type of structural unit derived from the other monomer, or may have two or more types.

<Structural unit (C)>
The resin has a structural unit (C) derived from an anionic reactive surfactant having an ethylenically unsaturated double bond and an oxyethylene group (that is, a specific anionic reactive surfactant).
In the present specification, the “structural unit derived from an anionic reactive surfactant” means a structural unit formed by addition polymerization of an anionic reactive surfactant.
The structural unit (C) contributes to control of the particle diameter of the resin particles.
When the resin has the structural unit (C), the resin particles are fine (specifically, the average particle diameter is 10 nm or more and 100 nm or less). It becomes a clogged film and is considered to be excellent in transparency.

The specific anionic reactive surfactant is not particularly limited as long as it has an ethylenically unsaturated double bond and an oxyethylene group.
Since the specific anionic reactive surfactant has an oxyethylene group, it has excellent copolymerizability with the monomer. Moreover, since an oxyethylene group has higher hydrophilicity than an oxypropylene group or an oxybutylene group, for example, a dense hydrated layer can be formed on the surface of resin particles. Therefore, when the resin contains a structural unit derived from a reactive surfactant having an oxyethylene group, the dispersibility of the resin particles in the aqueous medium tends to be further increased.

The average number of added moles of oxyethylene groups is not particularly limited, but is preferably 5 or more from the viewpoint of dispersibility of resin particles in an aqueous medium, for example.
In addition, the average added mole number of oxyethylene groups is preferably 50 or less from the viewpoint that the viscosity is not excessively increased and the productivity is improved when a (meth) acrylic resin emulsion is produced.

An ethylenically unsaturated double bond can be included by providing a group having an ethylenically unsaturated double bond.
Specific examples of the group having an ethylenically unsaturated double bond include (meth) acryloyl group, vinyl group, allyl group, isopropenyl group, 1-propenyl group, allyloxy group, styryl group and the like.
Among these, as a group having an ethylenically unsaturated double bond, a 1-propenyl group is preferable.
The 1-propenyl group has high reactivity, and is sufficient as a structural unit derived from a monomer such as a specific (meth) acrylic monomer, a monomer having a methylol group, or a (meth) acrylic acid alkyl ester monomer. Therefore, it is difficult for unreacted surfactant to remain. Therefore, according to the (meth) acrylic resin emulsion containing resin particles having a structural unit (C) derived from a specific anionic reactive surfactant having a 1-propenyl group, a primer layer that is superior in foam resistance is formed. There is a tendency to be able to.

  As the specific anionic reactive surfactant, for example, an anionic reactive surfactant represented by the following formula (3) is preferable.

In the formula (3), X represents —SO ₃ M, —COOM, or —PO ₃ M.
M represents an alkali metal atom, an alkaline earth metal atom, or an ammonium group.
Specific examples of the alkali metal atom include a sodium atom and a potassium atom.
Specific examples of the alkaline earth metal atom include a calcium atom and a barium atom.
As X, for example, —SO ₃ NH ₄ is preferable from the viewpoint that the formed primer layer has excellent water resistance.

In Formula (3), p represents an integer of 1 to 3, and for example, 2 is preferable from the viewpoint of surface activity.
q represents the average number of moles of oxyethylene groups added (also referred to as “average number of repeating oxyethylene units”). q represents an integer of 5 to 40. For example, from the viewpoint of dispersibility of resin particles in an aqueous medium, an integer of 5 to 20 is preferable, and an integer of 8 to 15 is more preferable.

  Examples of commercially available products of specific anionic reactive surfactants include Aqualon (registered trademark) KH-05 [active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium [average of oxyethylene groups] Addition mole number: 5], active ingredient amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon (registered trademark) KH-10 [active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate Ester ammonium [average added mole number of oxyethylene group: 10], active ingredient amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd., Aqualon (registered trademark) AR-10 [active ingredient: polyoxyethylene styrenated propenyl Ammonium phenyl ether sulfate [average added mole number of oxyethylene group: 10], amount of active ingredient 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon (registered trademark) AR-20 [active ingredient: ammonium polyoxyethylene styrenated propenyl phenyl ether sulfate [average added mole number of oxyethylene group: 20], effective Component amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon (registered trademark) HS-10 [active ingredient: ammonium polyoxyethylene nonylpropenyl phenyl ether sulfate [average number of moles of oxyethylene group added: 10] , Active ingredient amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.], Aqualon (registered trademark) BC-10 [active ingredient: ammonium polyoxyethylene nonylpropenyl phenyl ether sulfate [average added mole number of oxyethylene group: 10], active ingredient amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.] Aron (registered trademark) BC-20 [active ingredient: polyoxyethylene nonylpropenyl phenyl ether ammonium sulfate [average added mole number of oxyethylene group: 20], active ingredient amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd. ], ADEKA rear soap (registered trademark) SR-10 [active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether ammonium sulfate [average added mole number of oxyethylene group: 10], active ingredient amount: 100 % By mass, ADEKA Co., Ltd., ADEKA rear soap (registered trademark) SR-20 [active ingredient: ammonium polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate [average added mole number of oxyethylene group: 20] ], Active ingredient amount: 100% by mass, ADEKA Corporation], Adekaria Soap (registered trademark) SR-3025 [active ingredient: ammonium polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate [average added mole number of oxyethylene group: 30], active ingredient amount: 25% by mass, ( ADEKA Co., Ltd.].

  The resin may have only one type of structural unit (C) or may have two or more types.

The proportion (that is, content) of the structural unit (C) in the resin is the structural unit derived from the reactive surfactant including the structural unit of the resin (however, an anionic reactive surfactant and a nonionic reactive surfactant). 0.3 parts by mass or more is preferable, 0.5 parts by mass or more is more preferable, and 1.0 part by mass or more is more preferable.
The content of the structural unit (C) in the resin is the structural unit of the resin (however, excluding the structural unit derived from the reactive surfactant including an anionic reactive surfactant and a nonionic reactive surfactant). There exists a tendency which is easy to control the particle diameter of the particle | grains of resin as it is 0.3 mass part or more with respect to a total of 100 mass parts.
Moreover, the content rate of the structural unit (C) in resin is the structural unit of resin (however, the structural unit derived from the reactive surfactant containing an anionic reactive surfactant and a nonionic reactive surfactant is remove | excluded. .) Is preferably 20.0 parts by mass or less, more preferably 15.0 parts by mass or less, and still more preferably 10.0 parts by mass or less.
The content of the structural unit (C) in the resin is the structural unit of the resin (however, excluding the structural unit derived from the reactive surfactant including an anionic reactive surfactant and a nonionic reactive surfactant). There exists a tendency which can form the primer layer which is more excellent in foaming resistance as it is 20.0 mass parts or less with respect to a total of 100 mass parts. Moreover, there exists a tendency for the water resistance of the primer layer formed to improve.

<Structural unit (D)>
The resin is represented by the following formula (1), and the nonionic reactive surfactant has an average added mole number of oxyethylene groups larger than the average added mole number of oxyethylene groups possessed by the specific anionic reactive surfactant. It has a structural unit (D) derived from (specific nonionic surfactant).
In the present specification, the “structural unit derived from a nonionic reactive surfactant” means a structural unit formed by addition polymerization of a nonionic reactive surfactant.
The structural unit (D) contributes to the improvement of miscibility with various additives (for example, metal salts and amine salts).

In the formula (1), Y represents a substituent represented by the following formula (2).
m represents an integer of 1 to 3, and for example, 2 is preferable from the viewpoint of surface activity.
n represents the average number of added moles of oxyethylene groups (also referred to as the average number of repeating oxyethylene units). n represents an integer of 8 to 100. For example, from the viewpoint of dispersibility of resin particles in an aqueous medium, 8 to 50 is preferable, 8 to 40 is more preferable, and 10 to 30 is still more preferable.

The average addition mole number of the oxyethylene group that the specific nonionic reactive surfactant has is larger than the average addition mole number of the oxyethylene group that the specific anionic reactive surfactant has.
Resin particles having a structural unit derived from an anionic reactive surfactant tend to form an aggregate when the anionic reactive surfactant is attracted to an amine salt or the like.
In contrast, the (meth) acrylic resin emulsion of the present invention contains resin particles having a structural unit derived from an anionic reactive surfactant, but is excellent in miscibility with amine salts and the like and produces aggregates. hard. About the reason, the present inventors presume as follows.
In the resin particles contained in the (meth) acrylic resin emulsion of the present invention, the oxyethylene chain of the specific nonionic reactive surfactant is longer than the oxyethylene chain of the specific anionic reactive surfactant. Therefore, it is considered that the physical failure due to the oxyethylene chain of the specific nonionic reactive surfactant prevents the aggregation reaction between the specific anionic reactive surfactant and the amine salt.
As described above, in the (meth) acrylic resin emulsion of the present invention, since the generation of aggregates is suppressed, even if various additives (metal salt and amine salt) are used in combination, a primer layer having excellent transparency can be formed. It can be realized. In addition, the specific nonionic reactive surfactant contains a highly reactive 1-propenyl group and is strongly chemically bonded to a monomer having a specific (meth) acrylic monomer and a methylol group. Can function stably and effectively.

  As the specific nonionic reactive surfactant, a compound represented by the following formula (I) can be used.

  In formula (I), X represents a hydrogen atom. m1 represents an integer of 1 to 3, and n1 represents an integer of 8 to 100.

  The resin may have only one type of structural unit (D) or may have two or more types.

The proportion (that is, content) of the structural unit (D) in the resin is the structural unit derived from the reactive surfactant including the structural unit of the resin (however, an anionic reactive surfactant and a nonionic reactive surfactant). 0.1 parts by mass or more is preferable, 1.0 parts by mass or more is more preferable, and 5.0 parts by mass or more is still more preferable.
The content of the structural unit (D) in the resin is the structural unit of the resin (however, excluding the structural unit derived from the reactive surfactant containing an anionic reactive surfactant and a nonionic reactive surfactant). When the content is 0.1 parts by mass or more with respect to 100 parts by mass in total, the dispersion stability of the resin particles becomes better, and the particles tend not to aggregate more easily.
Moreover, the content rate of the structural unit (D) in resin is the structural unit of resin (however, the structural unit derived from the reactive surfactant containing an anionic reactive surfactant and a nonionic reactive surfactant is remove | excluded. 3) is preferably 30.0 parts by mass or less, more preferably 25.0 parts by mass or less, and still more preferably 20.0 parts by mass or less.
The content of the structural unit (D) in the resin is the structural unit of the resin (however, excluding the structural unit derived from the reactive surfactant containing an anionic reactive surfactant and a nonionic reactive surfactant). There exists a tendency which can form the primer layer which is more excellent in foaming resistance as it is 30.0 mass parts or less with respect to a total of 100 mass parts. Moreover, there exists a tendency for the water resistance of the primer layer formed to improve.

-Average particle diameter of resin particles-
The average particle size of the resin particles is 10 nm to 100 nm, preferably 15 nm to 80 nm, and more preferably 20 nm to 60 nm.
When the average particle diameter of the resin particles is 10 nm or more, the production suitability is excellent.
When the average particle diameter of the resin particles is 100 nm or less, a primer layer having excellent transparency can be formed. When the particle diameter of the resin particles is large, voids are generated in the formed film. In the present invention, since the resin particles have an average particle diameter of 100 nm or less and a film in which resin particles are densely packed (that is, a primer layer) can be formed, the transparency of the primer layer is excellent.

In the present specification, “average particle diameter of resin particles” means “New Experimental Chemistry Lecture 4 Basic Technology 3 Hikari (II)” pages 725 to 741 edited by the Chemical Society of Japan (July 20, 1977 Maruzen) It is the value measured by the dynamic light scattering method described in (Issuance Co., Ltd.). The specific method is as follows.
The (meth) acrylic resin emulsion was diluted with deionized water and sufficiently stirred and mixed, and then 5 mL was collected in a 10 mm square glass cell using a Pasteur pipette, and this was taken as a dynamic light scattering photometer [ For example, it is set to Zetasizer 1000HS (trade name) of Sysmex Corporation. The set value of the attenuation rate (Attenuator) is set to x16 (16 times), and the concentration of the (meth) acrylic resin emulsion is adjusted so that the decay rate count rate is 150 kCps to 200 kCps, and then the measurement temperature is 25 ° C. ± The average particle diameter of the resin particles in the (meth) acrylic resin emulsion is determined by computer processing the results measured under conditions of 1 ° C. and a light scattering angle of 90 °. Moreover, the value of an average particle diameter uses the value of Z average.

-Glass transition temperature of resin-
The glass transition temperature (Tg) of the resin is not particularly limited, but is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, and still more preferably 15 ° C. or higher, from the viewpoint of blocking resistance.
The upper limit of the glass transition temperature (Tg) of the resin is preferably 80 ° C. or lower, for example.
The glass transition temperature (Tg) of the resin is a value measured by the following method using a differential scanning calorimeter (DSC).
After weighing 1 g of the (meth) acrylic resin emulsion in an aluminum dish, it is heated at 105 ° C. for 3 hours to obtain a dried resin product. The obtained dried resin is ground in a mortar to make a resin powder. This resin powder is used as a measurement sample. Next, 10 mg of resin powder as a measurement sample was packed in an aluminum sample pan [trade name: Tzero Pan, TA Instrument Co., Ltd.], and an aluminum lid [trade name: Tzero Hermetic Lid, TA Instrument Co., Ltd.] ] And then using a differential scanning calorimeter, measurement is performed under the following measurement conditions. The measurement is performed twice for the same measurement sample, and the value obtained by the second measurement is adopted as the glass transition temperature of the resin.
As the differential scanning calorimeter, for example, a differential scanning calorimeter (trade name: DSC2500) of TA Instrument Co., Ltd. can be used.

-Measurement conditions-
Atmospheric conditions: Under air Measurement range: -50 ° C to 100 ° C
Temperature rising rate: 10 ° C / min Standard material: Empty sample pan

-Content of resin particles-
The ratio of the resin particles in the (meth) acrylic resin emulsion of the present invention (that is, the content) is not particularly limited. For example, from the viewpoint of production stability, with respect to the total mass of the (meth) acrylic resin emulsion, 15.0 mass% or more and 50.0 mass% or less are preferable, 20.0 mass% or more and 45.0 mass% or less are more preferable, and 25.0 mass% or more and 40.0 mass% or less are still more preferable.

[Aqueous medium]
The (meth) acrylic resin emulsion of the present invention contains an aqueous medium.
The aqueous medium contained in the (meth) acrylic resin emulsion of the present invention can function as a dispersion medium for resin particles.
The aqueous medium is not particularly limited and can be appropriately selected according to the purpose.
Examples of the aqueous medium include water, a mixed solution of water and an alcohol solvent, and the like.
As the aqueous medium, for example, water is preferable from the viewpoint of dispersibility of resin particles.
The content rate of the aqueous medium in the (meth) acrylic resin emulsion of the present invention is not particularly limited. For example, from the viewpoint of production stability, 50.0% by mass or more with respect to the total mass of the (meth) acrylic resin emulsion. 85.0 mass% or less is preferable, 55.0 mass% or more and 80.0 mass% or less are more preferable, and 60.0 mass% or more and 75.0 mass% or less are still more preferable.

[Other ingredients]
The (meth) acrylic resin emulsion of the present invention may contain components other than those already described (so-called other components) as long as the effects of the present invention are not impaired.
Examples of other components include a crosslinking agent, an antioxidant, an antistatic agent, a pH adjuster, and an antifoaming agent.

-PH of (meth) acrylic resin emulsion-
The pH of the (meth) acrylic resin emulsion of the present invention is preferably 5.0 to 9.0, for example, from the viewpoint of dispersibility of resin particles in an aqueous medium.
The method for measuring the pH of the (meth) acrylic resin emulsion of the present invention is not particularly limited.
The pH of the (meth) acrylic resin emulsion of the present invention can be measured using, for example, LAQUA (trade name) manufactured by Horiba, Ltd., and a value measured at 25 ° C. is employed.

[Method for producing (meth) acrylic resin emulsion]
The manufacturing method of the (meth) acrylic resin emulsion of the present invention is not particularly limited as long as the (meth) acrylic resin emulsion described above can be manufactured.
As a method for producing the (meth) acrylic resin emulsion of the present invention, for example, from the viewpoint that it is easy to produce the (meth) acrylic resin emulsion described above, the (meth) acrylic resin of the present embodiment described below will be described. An emulsion production method is preferred.

  The production method of the (meth) acrylic resin emulsion of the present embodiment (hereinafter also referred to as “production method of the present embodiment”) includes a specific anionic reactive surfactant, a specific nonionic reactive surfactant, and an aqueous solution. In the presence of the medium, at least a specific (meth) acrylic monomer and a monomer having a methylol group are polymerized to obtain resin particles having an average particle size of 10 nm or more and 100 nm or less (hereinafter, Also referred to as “emulsion polymerization step”).

  Hereinafter, although each process in the manufacturing method of this embodiment is demonstrated, description is abbreviate | omitted about the detail which is common in the (meth) acrylic resin emulsion as stated above, for example, the detail of the component contained in a (meth) acrylic resin emulsion. To do.

<Emulsion polymerization process>
The emulsion polymerization step comprises at least a specific (meth) acrylic monomer and a monomer having a methylol group in the presence of a specific anionic reactive surfactant, a specific nonionic reactive surfactant, and an aqueous medium. Is a step of obtaining resin particles having an average particle diameter of 10 nm or more and 100 nm or less.
In the emulsion polymerization step, at least a specific (meth) acrylic monomer, a monomer having a methylol group, a specific anionic reactive surfactant, and a specific nonionic reactive surfactant are copolymerized. Thus, resin particles having an average particle diameter of 10 nm or more and 100 nm or less having a hydrated layer formed on the surface by the specific anionic reactive surfactant and the specific nonionic reactive surfactant are obtained.

It does not restrict | limit especially as a polymerization method, For example, the method of (1)-(3) shown below is mentioned.
(1) In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, a dropping funnel, etc., at least a specific (meth) acrylic monomer, a monomer having a methylol group, and a specific anionic reactivity A surfactant, a specific nonionic reactive surfactant, and an aqueous medium are charged, the temperature in the reaction vessel is raised, and a polymerization initiator, a reducing agent, etc. are added as appropriate to advance the emulsion polymerization reaction. Method (so-called batch preparation method),
(2) In a reaction vessel equipped with a thermometer, a stirring bar, a reflux condenser, a dropping funnel, etc., at least a specific anionic reactive surfactant, a specific nonionic reactive surfactant, an aqueous medium, And the temperature inside the reaction vessel is raised, and then a monomer component [at least, a monomer having a specific (meth) acrylic monomer and a methylol group] is dropped, and a polymerization initiator, a reducing agent, etc., as appropriate. In order to advance the emulsion polymerization reaction (so-called monomer dropping method),
(3) A monomer component [at least a specific (meth) acrylic monomer and a monomer having a methylol group] is preliminarily at least a specific anionic reactive surfactant and a specific nonionic reactive surfactant. And an aqueous medium to obtain a pre-emulsion, and the obtained pre-emulsion is dropped into a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, a dropping funnel, etc. And a method of adding a polymerization initiator, a reducing agent, and the like to advance the emulsion polymerization reaction (so-called emulsion monomer dropping method).
Among these, as the polymerization method, for example, the emulsion monomer dropping method (3) is preferable from the viewpoint of production stability.

The polymerization temperature is, for example, 50 ° C to 80 ° C, preferably 60 ° C to 80 ° C.
The polymerization time is, for example, 4 hours to 6 hours, preferably 4 hours to 5 hours.

The amount of the specific (meth) acrylic monomer used is preferably 0.1 parts by mass or more and 0.5 parts by mass or more with respect to 100 parts by mass of the total amount of monomers from the viewpoint of production stability. More preferred is 1.0 part by mass or more.
Moreover, the usage-amount of a specific (meth) acryl monomer is 20.0 mass parts or less with respect to 100 mass parts of total amounts of a monomer from a viewpoint of manufacturing stability, for example, 15.0 mass parts The following is more preferable, and 10.0 parts by mass or less is still more preferable.

The amount of the monomer having a methylol group is, for example, preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, and 1.0 parts by mass with respect to 100 parts by mass of the total amount of monomers. The above is more preferable.
When the amount of the monomer having a methylol group is 0.2 parts by mass or more with respect to 100 parts by mass of the total amount of the monomers, the primer layer formed becomes a denser film and is more excellent. There is a tendency to exhibit solvent resistance.
The amount of the monomer having a methylol group is preferably 10.0 parts by mass or less, more preferably 7.0 parts by mass or less, and more preferably 5.0 parts by mass with respect to 100 parts by mass of the total amount of monomers. More preferred is less than or equal to parts by weight.
When the amount of the monomer having a methylol group is 10.0 parts by mass or less with respect to 100 parts by mass of the total amount of monomers, enlargement of resin particles due to a decrease in production stability is satisfactorily suppressed. , The primer layer formed tends to exhibit better transparency.

The amount of the specific anionic reactive surfactant used is, for example, preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, and 1.0 mass with respect to 100 parts by mass of the total amount of monomers. Part or more is more preferable.
When the amount of the specific anionic reactive surfactant used is 0.3 parts by mass or more with respect to 100 parts by mass of the total amount of monomers, the particle diameter of the resin particles tends to be more easily controlled.
The amount of the specific anionic reactive surfactant used is preferably 20.0 parts by mass or less, more preferably 15.0 parts by mass or less, with respect to 100 parts by mass of the total amount of monomers. 0 parts by mass or less is more preferable.
When the amount of the specific anionic reactive surfactant used is 20.0 parts by mass or less with respect to 100 parts by mass of the total amount of monomers, there is a tendency that a primer layer that is more excellent in foaming resistance can be formed. Moreover, there exists a tendency for the water resistance of the primer layer formed to improve.

The amount of the specific nonionic reactive surfactant used is, for example, preferably 0.1 parts by mass or more, more preferably 1.0 parts by mass or more, and 5.0 parts by mass with respect to 100 parts by mass of the total amount of monomers. Part or more is more preferable.
When the amount of the specific nonionic reactive surfactant used is 0.1 parts by mass or more with respect to 100 parts by mass of the total amount of the monomers, the dispersion stability of the resin particles becomes better, and the particles are aggregated. Tend to be less likely to occur.
Moreover, the usage-amount of a specific nonionic type reactive surfactant is 30.0 mass parts or less with respect to 100 mass parts of total amounts of a monomer, for example, 25.0 mass parts or less are more preferable, 20. 0 parts by mass or less is more preferable.
When the amount of the specific nonionic reactive surfactant used is 30.0 parts by mass or less with respect to 100 parts by mass of the total amount of monomers, there is a tendency that a primer layer having superior foam resistance can be formed. Moreover, there exists a tendency for the water resistance of the primer layer formed to improve.

In the emulsion polymerization step, when the (meth) acrylic acid alkyl ester monomer is used, the amount of the (meth) acrylic acid alkyl ester monomer used is, for example, from the viewpoint of adjusting the glass transition temperature of the resin. 70.0 parts by mass or more is preferable, 80.0 parts by mass or more is more preferable, and 85.0 parts by mass or more is more preferable with respect to 100 parts by mass of the total body.
The amount of the (meth) acrylic acid alkyl ester monomer used is preferably 99.9 parts by mass or less with respect to 100 parts by mass of the total amount of monomers, from the viewpoint of adjusting the glass transition temperature of the resin. The amount is more preferably 0.0 part by mass or less, and still more preferably 98.0 parts by mass or less.

  In the emulsion polymerization step, various additives such as a polymerization initiator, a reducing agent, a chain transfer agent, and a pH adjuster may be used.

(Polymerization initiator)
Any polymerization initiator can be used without particular limitation as long as it can be used for ordinary emulsion polymerization.
Examples of the polymerization initiator include persulfates represented by ammonium persulfate, sodium persulfate, and potassium persulfate, organic peroxides represented by t-butyl hydroperoxide and cumene hydroperoxide, and hydrogen peroxide. Can be mentioned.
When a polymerization initiator is used in the emulsion polymerization step, only one polymerization initiator may be used, or two or more polymerization initiators may be used.

The polymerization initiator is used in an amount usually used.
The usage-amount of a polymerization initiator is 0.1 mass part-2 mass parts with respect to a total of 100 mass parts of the monomer which is a raw material, Preferably 0.3 mass part-1.5 mass parts It is.

(Reducing agent)
In the emulsion polymerization step, a reducing agent may be used together with the above-described polymerization initiator.
Examples of reducing agents include sodium metabisulfite, sodium sulfite, sodium bisulfite, sodium pyrosulfite (also referred to as “sodium disulfite”), sodium hydroxymethanesulfinate, sodium pyrophosphate, thioglycolic acid, sodium thiosulfate, ascorbine Examples include acid, tartaric acid, citric acid, and glucose.
When a reducing agent is used in the emulsion polymerization step, only one reducing agent may be used, or two or more reducing agents may be used.

The reducing agent is used in an amount usually used.
The amount of the reducing agent used is, for example, 0.1 parts by weight to 2 parts by weight, preferably 0.2 parts by weight to 1.5 parts by weight with respect to 100 parts by weight of the total amount of monomers as raw materials. is there.

<Other processes>
The manufacturing method of this embodiment may have processes other than an emulsion polymerization process as needed.

  In the manufacturing method of the present embodiment described above, emulsion polymerization is exemplified as a method for obtaining resin particles. However, the method for obtaining resin particles in the present invention is not limited to the above emulsion polymerization. For example, methods such as suspension polymerization and seed polymerization can also be used.

Hereinafter, the present invention will be described more specifically with reference to examples. The present invention is not limited to the following examples as long as the gist thereof is not exceeded.
The pH of the (meth) acrylic resin emulsion produced in this example was measured by the measurement method described above. Moreover, the thing similar to what was described as an example was used for the measuring apparatus.

[Production of (meth) acrylic resin emulsion]
[Example 1]
In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and “AQUALON (registered trademark) AR-10” which is an anionic reactive surfactant [Daiichi Kogyo Seiyaku Co., Ltd.] was charged with 2.0 parts by mass, and the temperature inside the reaction vessel was raised to 60 ° C. while purging with nitrogen.
Meanwhile, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) AR-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [a compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 Parts by mass, 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65 0.0 part by mass By 拌 were prepared pre-emulsion.
Next, while maintaining the internal temperature of the reaction vessel at 57 ° C., 3.5 mass% perbutyl (registered trademark) H aqueous solution [chemical name: t-butyl hydroperoxide, active ingredient amount: 70 mass%, NOF Corporation )] [Polymerization initiator] 5.8 parts by mass and 10.0 parts by mass of an aqueous solution of 10.0% by mass sodium hydroxymethanesulfinate dihydrate [reducing agent] were added to initiate the emulsion polymerization reaction.
While maintaining the internal temperature of the reaction vessel at 57 ° C., 5 minutes after the addition of the above polymerization initiator and reducing agent, the pre-emulsion prepared above and a 3.5 mass% perbutyl (registered trademark) H aqueous solution [polymerization start Agent] 5.8 parts by mass and 2.0 mass% sodium hydroxymethanesulfinate dihydrate aqueous solution [reducing agent] 7.4 parts by mass were sequentially added uniformly over 3 hours to effect emulsion polymerization. After completion of the sequential addition, the obtained emulsion polymer was aged at 57 ° C. for 2 hours and then cooled to room temperature, and pH was adjusted with an appropriate amount of aqueous ammonia solution to obtain a (meth) acrylic resin emulsion having a pH of 8.8. It was. The solid content of the obtained (meth) acrylic resin emulsion was 34.4% by mass.

[Example 2]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 35.2 mass%.
“55.9 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 5.0 parts by mass, and after stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], n- 31.5 parts by mass of butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], 65.0 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer], And stir The emulsion was prepared. "

Example 3
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.9 mass%.
“82.0 parts by mass of deionized water, 3.0 part by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity 20.0 parts by mass of “(I) -20” [compound represented by the above-described formula (I), m1≈2, n1≈20], which is a surfactant, was stirred, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], n- 31.5 parts by mass of butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], 65.0 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer], And stir Les emulsion was prepared. "

Example 4
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 35.1 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity “(I) -10” which is a surfactant [compound represented by the above-mentioned formula (I), m1≈2, n1≈10] 2.5 parts by mass, and a nonionic reactive surfactant “(I) -30” [a compound represented by the above-mentioned formula (I), m1≈2, n1≈30], 2.5 parts by mass, and after stirring, methacrylic acid (MAA) [(Meth) acrylic monomer having a carboxy group] 1.5 parts by mass, N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass, and n-butyl acrylate (n- BA) [(meth) acrylic acid alkyl ester monomer] 31.5 parts by mass And methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65.0 parts by mass, by stirred into to prepare a pre-emulsion. "

Example 5
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.8 mass%.
“70.0 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity “(I) -10” which is a surfactant [a compound represented by the above-described formula (I), m1≈2, n1≈10] 10.0 parts by mass, and a nonionic reactive surfactant After adding 10.0 parts by mass of “(I) -30” [compound represented by the above-described formula (I), m1≈2, n1≈30], and then stirring, methacrylic acid (MAA) [(Meth) acrylic monomer having a carboxy group] 1.5 parts by mass, N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass, and n-butyl acrylate (n- BA) [(meth) acrylic acid alkyl ester monomer] 31.5 mass When, by stirred into a methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65.0 parts by mass, to prepare a pre-emulsion. "

Example 6
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 33.6% by mass.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], and ethyl acrylate (EA) [(meth) acrylic acid alkyl ester monomer] 37.0 parts by mass and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 59.5 parts by mass were stirred. By doing Preema Deployment was prepared. "

Example 7
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.1 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], 2- 33.6 parts by mass of ethylhexyl acrylate (2EHA) [(meth) acrylic acid alkyl ester monomer] and 62.9 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] Stir And in, to prepare a pre-emulsion. "

Example 8
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 32.9 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], n- 51.1 parts by mass of butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], 45.4 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer], And stir Les emulsion was prepared. "

Example 9
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 32.9 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [the compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], n- Butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 6.6 parts by mass, methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 89.9 parts by mass, And stir The emulsion was prepared. "

Example 10
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.9 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [the compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 0.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], n- 31.5 parts by mass of butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 66.0 parts by mass, And stir Les emulsion was prepared. "

Example 11
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 33.6% by mass.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [the compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, Methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] 5.0 parts by mass, N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass, n- Butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 33.1 parts by mass, methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 59.9 parts by mass, And stir Les emulsion was prepared. "

Example 12
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 35.0 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [the compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 0.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and 1.0 part by mass of 2-hydroxyethyl methacrylate (2HEMA) [(meth) acrylic monomer having a hydroxyl group] N-methylol acrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass, n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 30.9 mass Part and methyl methacrylate Rate (MMA) [(meth) acrylic acid alkyl ester monomer] 65.6 parts by mass, by stirred into to prepare a pre-emulsion. "

Example 13
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.8 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [the compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 0.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and 10.0 parts by mass of 2-hydroxyethyl methacrylate (2HEMA) [(meth) acrylic monomer having a hydroxyl group] N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass; n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 28.6 masses Part and methyl meta Relate (MMA) [(meth) acrylic acid alkyl ester monomer] and 58.9 parts by mass, by stirred into to prepare a pre-emulsion. "

Example 14
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 34.4% by mass.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, 1.5 parts by mass of acrylic acid (AA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], n- 31.5 parts by mass of butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], 65.0 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer], And stir the The Marushon was prepared. "

Example 15
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 35.0 mass%.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, Aronix (registered trademark) M-5300 [ω-carboxy-polycaprolactone (n≈2) monoacrylate, Toagosei Co., Ltd.] [(meth) acrylic monomer having a carboxy group] -2.0 parts by mass of methylol acrylamide (NMAM) [monomer having a methylol group], 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], Methyl methacrylate ( MA) By stirred into [(meth) acrylic acid alkyl ester monomer] and 65.0 parts by mass, to prepare a pre-emulsion. "

Example 16
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 34.7% by mass.
“In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic reactive surfactant“ AQUALON (registered trademark) KH-10 "Daiichi Kogyo Seiyaku Co., Ltd."
On the other hand, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) KH-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [a compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 Parts by mass, 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65 0.0 part by mass By 拌 were prepared pre-emulsion. "

Example 17
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 35.0 mass%.
“In a reaction vessel equipped with a thermometer, a stirring bar, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic reactive surfactant“ AQUALON (registered trademark) BC-10 "Daiichi Kogyo Seiyaku Co., Ltd."
On the other hand, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) BC-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [a compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 Parts by mass, 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65 0.0 part by mass By 拌 were prepared pre-emulsion. "

[Comparative Example 1]
In a reaction vessel equipped with a thermometer, a stirring bar, a reflux condenser, and a dropping funnel, 100 parts by mass of deionized water was charged, and the temperature in the reaction vessel was raised to 57 ° C. while purging with nitrogen.
Meanwhile, in a separate container, 43.8 parts by mass of deionized water and 2.0 parts by mass of “AQUALON (registered trademark) AR-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 5.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 Parts by mass, 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65 0.0 part by mass Doing, to prepare a pre-emulsion.
Further, in another container, 20.0 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) AR-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 5.0 parts by mass, which is a nonionic reactive surfactant. The aqueous emulsifier solution was prepared by stirring.
Next, while maintaining the internal temperature of the reaction vessel at 57 ° C., 3.5 mass% perbutyl (registered trademark) H aqueous solution [chemical name: t-butyl hydroperoxide, active ingredient amount: 70 mass%, NOF Corporation )] [Polymerization initiator] 5.8 parts by mass and 10.0 parts by mass of an aqueous solution of 10.0% by mass sodium hydroxymethanesulfinate dihydrate [reducing agent] were added to initiate the emulsion polymerization reaction.
While maintaining the internal temperature of the reaction vessel at 57 ° C., 5 minutes after the addition of the above polymerization initiator and reducing agent, the pre-emulsion prepared above and a 3.5 mass% perbutyl (registered trademark) H aqueous solution [polymerization start Agent] 5.8 parts by mass and 2.0 mass% sodium hydroxymethanesulfinate dihydrate aqueous solution [reducing agent] 7.4 parts by mass were sequentially added uniformly over 3 hours to effect emulsion polymerization. Subsequently, the emulsifier aqueous solution prepared above was added 1 hour after the start of sequential dropping. After completion of the sequential addition, the obtained emulsion polymer was aged at 57 ° C. for 2 hours and then cooled to room temperature, and pH was adjusted with an appropriate amount of aqueous ammonia solution to obtain a (meth) acrylic resin emulsion having a pH of 8.8. It was. Solid content of the obtained (meth) acrylic resin emulsion was 31.2 mass%.

[Comparative Example 2]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 35.1 mass%.
“In a reaction vessel equipped with a thermometer, a stir bar, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic non-reactive surfactant” Haitenol (registered trademark) NF -08 "[Daiichi Kogyo Seiyaku Co., Ltd.] 2.0 parts by mass, and the temperature inside the reaction vessel was raised to 60 ° C while purging with nitrogen.
On the other hand, in another container, 63.8 parts by mass of deionized water and “Hytenol (registered trademark) NF-08” [Daiichi Kogyo Seiyaku Co., Ltd.] 3.0, which is an anionic non-reactive surfactant. After adding 1 part by mass and 10.0 parts by mass of “Neugen (registered trademark) EA-177” [Daiichi Kogyo Seiyaku Co., Ltd.] which is a nonionic non-reactive surfactant, 1.5 parts by mass of acid (MAA) [(meth) acrylic monomer having a carboxy group], 2.0 parts by mass of N-methylolacrylamide (NMAM) [monomer having a methylol group], and n-butyl 31.5 parts by mass of acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] and 65.0 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] Put and stir And in, to prepare a pre-emulsion. "

[Comparative Example 3]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.2 mass%.
“In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic reactive surfactant“ AQUALON (registered trademark) KH-10 "Daiichi Kogyo Seiyaku Co., Ltd."
Meanwhile, in another container, 61.3 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) KH-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And 10.0 parts by mass of “ADEKA rear soap (registered trademark) ER-20” (ADEKA), which is a nonionic reactive surfactant, and then stirred, and then methacrylic acid (MAA) [(Meth) acrylic monomer having a carboxy group] 1.5 parts by mass, N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass, and n-butyl acrylate (n- BA) [(meth) acrylic acid alkyl ester monomer] 31.5 parts by mass and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65.0 parts by mass and stirred. This In, to prepare a pre-emulsion. "

[Comparative Example 4]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 33.6% by mass.
“63.8 parts by mass of deionized water and 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant are added and stirred. Then, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 mass Part, n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 31.5 parts by mass, methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65. A pre-emulsion was prepared by adding and stirring 0 parts by mass. "

[Comparative Example 5]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 34.7% by mass.
“In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic reactive surfactant“ AQUALON (registered trademark) KH-10 "Daiichi Kogyo Seiyaku Co., Ltd."
On the other hand, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) KH-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And 10.0 parts by weight of “Neugen (registered trademark) EA-177” which is a nonionic non-reactive surfactant, and after stirring, methacrylic acid (MAA) [having a carboxy group (meta ) Acrylic monomer] 1.5 parts by mass, N-methylol acrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass, n-butyl acrylate (n-BA) [(meth) acrylic Acid alkyl ester monomer] 31.5 parts by mass and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65.0 parts by mass, and the pre-emulsion is stirred. It was manufactured. "

[Comparative Example 6]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 32.8 mass%.
“In a reaction vessel equipped with a thermometer, a stir bar, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic non-reactive surfactant” Haitenol (registered trademark) NF -08 "[Daiichi Kogyo Seiyaku Co., Ltd.] 2.0 parts by mass, and the temperature inside the reaction vessel was raised to 60 ° C while purging with nitrogen.
On the other hand, in another container, 63.8 parts by mass of deionized water and “Hytenol (registered trademark) NF-08” [Daiichi Kogyo Seiyaku Co., Ltd.] 3.0, which is an anionic non-reactive surfactant. And, after stirring, 1.5 parts by weight of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [having a methylol group Monomer] 2.0 parts by mass, n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 31.5 parts by mass, methyl methacrylate (MMA) [(meth) acrylic acid Alkyl ester monomer] 65.0 parts by mass was added and stirred to prepare a pre-emulsion. "

[Comparative Example 7]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. The solid content of the obtained (meth) acrylic resin emulsion was 33.9% by mass.
“In a reaction vessel equipped with a thermometer, a stirring bar, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic reactive surfactant“ AQUALON AR-20 ” "Daiichi Kogyo Seiyaku Co., Ltd."
Meanwhile, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) AR-20” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [a compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 Parts by mass, 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65 0.0 part by mass By 拌 were prepared pre-emulsion. "

[Comparative Example 8]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the operation until preparation of the pre-emulsion was changed as follows. Solid content of the obtained (meth) acrylic resin emulsion was 34.5 mass%.
“In a reaction vessel equipped with a thermometer, a stirring bar, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and an anionic reactive surfactant“ AQUALON AR-20 ” "Daiichi Kogyo Seiyaku Co., Ltd."
Meanwhile, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) AR-20” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -10” [the compound represented by the above-described formula (I), m1≈2, n1≈10] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 1.5 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and N-methylolacrylamide (NMAM) [monomer having a methylol group] 2.0 Parts by mass, 31.5 parts by mass of n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer], and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 65 0.0 part by mass By 拌 were prepared pre-emulsion. "

[Comparative Example 9]
In Example 1, a (meth) acrylic resin emulsion having a pH of 8.8 was obtained in the same manner as in Example 1 except that the preparation method of the pre-emulsion was changed as follows. The obtained (meth) acrylic resin emulsion had a solid content of 34.0% by mass.
“63.8 parts by mass of deionized water, 3.0 parts by mass of“ AQUALON (registered trademark) AR-10 ”[Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant, and nonionic reactivity Surfactant “(I) -20” [compound represented by the above-mentioned formula (I), m1≈2, n1≈20] 10.0 parts by mass, and after stirring, Methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] 1.5 parts by mass and n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] 31.5 parts by mass Part and methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 67.0 parts by mass were added and stirred to prepare a pre-emulsion. "

[Comparative Example 10]
In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water and “AQUALON (registered trademark) AR-10” which is an anionic reactive surfactant [Daiichi Kogyo Seiyaku Co., Ltd.] was charged in an amount of 2.0 parts by mass, and the temperature was raised to 57 ° C. while replacing the inside of the reaction vessel with nitrogen.
Meanwhile, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) AR-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [a compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, N-methylol acrylamide (NMAM) [monomer having a methylol group] 2.0 parts by mass and n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester monomer] A pre-emulsion was prepared by putting 33.0 parts by mass and 65.0 parts by mass of methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] and stirring.
Next, while maintaining the internal temperature of the reaction vessel at 57 ° C., 3.5 mass% perbutyl (registered trademark) H aqueous solution [chemical name: t-butyl hydroperoxide, active ingredient amount: 70 mass%, NOF Corporation )] [Polymerization initiator] 5.8 parts by mass and 10.0 parts by mass of an aqueous solution of 10.0% by mass sodium hydroxymethanesulfinate dihydrate [reducing agent] were added to initiate the emulsion polymerization reaction.
While maintaining the internal temperature of the reaction vessel at 57 ° C., 5 minutes after the addition of the above polymerization initiator and reducing agent, the pre-emulsion prepared above and a 3.5 mass% perbutyl (registered trademark) H aqueous solution [polymerization start Agent] 5.8 parts by mass and 2.0 mass% sodium hydroxymethanesulfinate dihydrate aqueous solution [reducing agent] 7.4 parts by mass were sequentially added uniformly over 3 hours to effect emulsion polymerization. After completion of the sequential addition, the obtained emulsion polymer was aged at 57 ° C. for 2 hours and then cooled to room temperature, and pH was adjusted with an appropriate amount of aqueous ammonia solution to obtain a (meth) acrylic resin emulsion having a pH of 8.8. It was. The solid content of the obtained (meth) acrylic resin emulsion was 31.4% by mass.

[Comparative Example 11]
In a reaction vessel equipped with a thermometer, a stirring bar, a reflux condenser, and a dropping funnel, 100.0 parts by mass of deionized water was charged, and the temperature was raised to 57 ° C. while replacing the inside of the reaction vessel with nitrogen.
On the other hand, in another container, 55.0 parts by mass of deionized water and “(I) -20” which is a nonionic reactive surfactant [a compound represented by the above-described formula (I), m1≈2 , N1≈20] 10.0 parts by mass, and after stirring, further 2.0 parts by mass of methacrylic acid (MAA) [(meth) acrylic monomer having a carboxy group] and n-butyl acrylate (N-BA) [(meth) acrylic acid alkyl ester monomer] 38.0 parts by mass, methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 30.0 parts by mass, styrene ( St) [monomer having an aromatic ring] and 30.0 parts by mass were added and stirred to prepare a pre-emulsion.
Next, while maintaining the internal temperature of the reaction vessel at 57 ° C., 3.5 mass% perbutyl (registered trademark) H aqueous solution [chemical name: t-butyl hydroperoxide, active ingredient amount: 70 mass%, NOF Corporation )] [Polymerization initiator] 5.8 parts by mass and 10.0 parts by mass of an aqueous solution of 10.0% by mass sodium hydroxymethanesulfinate dihydrate [reducing agent] were added to initiate the emulsion polymerization reaction.
While maintaining the internal temperature of the reaction vessel at 57 ° C., 5 minutes after the addition of the above polymerization initiator and reducing agent, the pre-emulsion prepared above and a 3.5 mass% perbutyl (registered trademark) H aqueous solution [polymerization start Agent] 5.8 parts by mass and 2.0 mass% sodium hydroxymethanesulfinate dihydrate aqueous solution [reducing agent] 7.4 parts by mass were sequentially added uniformly over 3 hours to effect emulsion polymerization. After completion of the sequential addition, the obtained emulsion polymer was aged at 57 ° C. for 2 hours and then cooled to room temperature, and pH was adjusted with an appropriate amount of aqueous ammonia solution to obtain a (meth) acrylic resin emulsion having a pH of 8.8. It was. The solid content of the obtained (meth) acrylic resin emulsion was 32.6% by mass.

[Comparative Example 12]
In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 63.8 parts by mass of deionized water and “AQUALON (registered trademark) AR-10” which is an anionic reactive surfactant are used. [Daiichi Kogyo Seiyaku Co., Ltd.] was charged with 2.0 parts by mass, and the temperature in the reaction vessel was raised to 57 ° C. while purging with nitrogen.
Meanwhile, in another container, 63.8 parts by mass of deionized water and 3.0 parts by mass of “AQUALON (registered trademark) AR-10” [Daiichi Kogyo Seiyaku Co., Ltd.] which is an anionic reactive surfactant. And “(I) -20” [a compound represented by the above-described formula (I), m1≈2, n1≈20] 10.0 parts by mass, which is a nonionic reactive surfactant. After stirring, 5.0 parts by mass of 2-hydroxyethyl methacrylate (2HEMA) [(meth) acrylic monomer having a hydroxyl group] and n-butyl acrylate (n-BA) [(meth) acrylic acid alkyl ester Monomer] 35.0 parts by mass, methyl methacrylate (MMA) [(meth) acrylic acid alkyl ester monomer] 30.0 parts by mass, and styrene (St) [monomer having an aromatic ring] Add 0 parts by mass and stir And in, to prepare a pre-emulsion.
Next, while maintaining the internal temperature of the reaction vessel at 57 ° C., 3.5 mass% perbutyl (registered trademark) H aqueous solution [chemical name: t-butyl hydroperoxide, active ingredient amount: 70 mass%, NOF Corporation )] [Polymerization initiator] 5.8 parts by mass and 10.0 parts by mass of an aqueous solution of 10.0% by mass sodium hydroxymethanesulfinate dihydrate [reducing agent] were added to initiate the emulsion polymerization reaction.
While maintaining the internal temperature of the reaction vessel at 57 ° C., 5 minutes after the addition of the above polymerization initiator and reducing agent, the pre-emulsion prepared above and a 3.5 mass% perbutyl (registered trademark) H aqueous solution [polymerization start Agent] 5.8 parts by mass and 2.0 mass% sodium hydroxymethanesulfinate dihydrate aqueous solution [reducing agent] 7.4 parts by mass were sequentially added uniformly over 3 hours to effect emulsion polymerization. After completion of the sequential addition, the obtained emulsion polymer was aged at 57 ° C. for 2 hours and then cooled to room temperature, and pH was adjusted with an appropriate amount of aqueous ammonia solution to obtain a (meth) acrylic resin emulsion having a pH of 8.8. It was. Solid content of the obtained (meth) acrylic resin emulsion was 33.3 mass%.

[Measurement]
The following measurements were performed using the (meth) acrylic resin emulsions of Examples 1 to 17 and Comparative Examples 1 to 12 obtained above. The results are shown in Tables 1 and 2.

1. Glass transition temperature (Tg) of resin
The glass transition temperature (Tg) of the resin was measured by the following method using a differential scanning calorimeter (DSC).
1 g of the (meth) acrylic resin emulsion was weighed on an aluminum dish and then heated at 105 ° C. for 3 hours to obtain a dried resin product. The obtained dried resin product was ground in a mortar to obtain resin powder. This resin powder is used as a measurement sample. Next, 10 mg of resin powder as a measurement sample is packed in an aluminum sample pan [trade name: Tzero Pan, TA Instrument Co., Ltd.], and an aluminum lid [trade name: Tzero Hermetic Lid, TA Instrument Co., Ltd.] ] And then using a differential scanning calorimeter [trade name: DSC2500, TA Instrument Co., Ltd.] under the following measurement conditions. The measurement was performed twice for the same measurement sample, and the value obtained by the second measurement was adopted as the glass transition temperature of the resin.

-Measurement conditions-
Atmospheric conditions: Under air Measurement range: -50 ° C to 100 ° C
Temperature rising rate: 10 ° C / min Standard material: Empty sample pan

2. Average particle size of resin particles (Meth) acrylic resin emulsion was diluted 15 times with deionized water, mixed well with stirring, and 5 mL was collected using a Pasteur pipette in a 10 mm square glass cell. This was set in a dynamic light scattering photometer [trade name: Zetasizer 1000HS, Sysmex Corporation]. The set value of the attenuation rate (Attenuator) is set to x16 (16 times), and the concentration of the (meth) acrylic resin emulsion is adjusted so that the decay rate count rate is 150 kCps to 200 kCps, and then the measurement temperature is 25 ° C. ± The average particle diameter of the resin particles in the (meth) acrylic resin emulsion was determined by computer processing the results measured under conditions of 1 ° C. and a light scattering angle of 90 °. In addition, the value of average particle diameter used the value of Z average.

In Tables 1 and 2, “-” means that the corresponding component is not blended.
The compounding quantity of surfactant shown in Table 1 is an active ingredient conversion value.

  “Partial structure represented by Formula (A)” and “Partial structure represented by Formula (B)” described in Tables 1 and 2 are as follows. In formula (B), b represents an integer of 1 to 3.

Details of each component described in Table 1 and Table 2 are as follows.
<(Meth) acrylic monomer having carboxy group>
“MAA”: methacrylic acid “AA”: acrylic acid “M-5300”: Aronix® M-5300 [ω-carboxy-polycaprolactone (n≈2) monoacrylate, Toagosei Co., Ltd.]
<(Meth) acrylic monomer having a hydroxyl group>
“2HEMA”: 2-hydroxyethyl methacrylate <monomer having a methylol group>
“NMAM”: N-methylolacrylamide <(meth) acrylic acid alkyl ester monomer>
“N-BA”: n-butyl acrylate “EA”: ethyl acrylate “2EHA”: 2-ethylhexyl acrylate “MMA”: methyl methacrylate <monomer having an aromatic ring>
“St”: Styrene

<Anionic reactive surfactant>
“AR-10”: Aqualon (registered trademark) AR-10 [active ingredient: ammonium polyoxyethylene styrenated propenyl phenyl ether sulfate [average added mole number of oxyethylene group: 10], amount of active ingredient: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.] [Anionic Reactive Surfactant Represented by Formula (3)]
“AR-20”: AQUALON (registered trademark) AR-20 [active ingredient: ammonium polyoxyethylene styrenated propenyl phenyl ether sulfate [average added mole number of oxyethylene group: 20], active ingredient amount: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.] [Anionic Reactive Surfactant Represented by Formula (3)]
“KH-10”: AQUALON (registered trademark) KH-10 [active ingredient: ammonium polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate [average number of moles of oxyethylene group added: 10], amount of active ingredient : 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.]
“BC-10”: Aqualon (registered trademark) BC-10 [active ingredient: polyoxyethylene nonylpropenyl phenyl ether sulfate ammonium (average number of moles of oxyethylene group added: 10), active ingredient amount: 99 mass%, Ichi Kogyo Seiyaku Co., Ltd.]
<Anionic non-reactive surfactant>
“NF-08”: Haitenol (registered trademark) NF-08 [active ingredient: polyoxyethylene styrenated phenyl ether ammonium sulfate [average added mole number of oxyethylene group: 8], active ingredient amount: 95% by mass, first Industrial Pharmaceutical Co., Ltd.]

<Nonionic reactive surfactant>
“(I) -10”: Compound represented by the above-described formula (I) [m1≈2, n1≈10]
“(I) -20”: Compound represented by the above-described formula (I) [m1≈2, n1≈20]
“(I) -30”: Compound represented by the above-described formula (I) [m1≈2, n1≈30]
“ER-20”: ADEKA rear soap (registered trademark) ER-20 [active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether [average number of moles of oxyethylene group added: 20], amount of active ingredient: 75% by mass, ADEKA Corporation]
<Nonionic non-reactive surfactant>
“EA-177”: Neugen (registered trademark) EA-177 [active ingredient: polyoxyethylene styrenated phenyl ether [average added mole number of oxyethylene group: 20], active ingredient amount: 100% by mass, Daiichi Kogyo Seiyaku (stock)]

[Evaluation]
The following evaluation was performed about the (meth) acrylic resin emulsion of Examples 1 to 17 and Comparative Examples 1 to 12 obtained above. The results are shown in Tables 3 and 4.

1. Transparency PET film [trade name: Lumirror (registered trademark) 125T60, biaxially stretched PET film, Toray Industries, Inc.] was cut into A4 size to prepare a PET film piece. The haze of the prepared PET film piece was measured using a haze meter [trade name: NDH-5000SP, Nippon Denshoku Industries Co., Ltd.]. As a result, the haze value of the PET film piece was 2.9.
Next, the (meth) acrylic resin emulsion was diluted with deionized water so that the solid content concentration was 2.2% by mass. The obtained diluted solution was applied onto the PET film piece whose haze value was measured in advance using No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a test piece. The haze of the obtained test piece was measured using a haze meter.
The haze value of the film was determined by subtracting the haze value of the PET film piece from the haze value of the test piece. If the haze value of the obtained film was less than 0.5, it was judged that the film was a (meth) acrylic resin emulsion capable of forming a film having excellent transparency.

2. Miscibility (1) Miscibility with aluminum phosphate PET film [trade name: Lumirror (registered trademark) 125T60, biaxially stretched PET film, Toray Industries, Inc.] was cut into A4 size, and a PET film piece (haze value: 2.9) was prepared.
Next, the (meth) acrylic resin emulsion was diluted with deionized water so that the solid content concentration was 2.2% by mass. The obtained diluted solution was applied onto the PET film piece prepared above using a No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a reference test piece.
Next, 5 parts by mass of a (meth) acrylic resin emulsion, 10 parts by mass of an aluminum phosphate 50% by mass aqueous solution, and 1 part by mass of glycerin were weighed into a reagent bottle, and the reagent bottle was shaken up and down 10 times. 150 parts by mass of deionized water was added to the liquid mixture obtained by shaking and mixed. The obtained liquid mixture was coated on the PET film piece prepared above using No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a test piece.
Subsequently, the haze of the reference test piece and the test piece was measured using a haze meter [trade name: NDH-5000SP, Nippon Denshoku Industries Co., Ltd.]. If the increase in the haze value from the reference test piece to the test piece is less than 1.0, it was judged to be a (meth) acrylic resin emulsion that can form a film having excellent miscibility with aluminum phosphate and excellent transparency. .

(2) Miscibility with calcium acetate The same operation as the operation in “(1) Miscibility with aluminum phosphate” was performed to obtain a reference test piece.
Next, 5 parts by mass of a (meth) acrylic resin emulsion, 10 parts by mass of 50% by mass calcium acetate, and 1 part by mass of glycerin were weighed into a reagent bottle, and the reagent bottle was shaken up and down 10 times. 150 parts by mass of deionized water was added to the liquid mixture obtained by shaking and mixed. The obtained liquid mixture was coated on the PET film piece prepared above using No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a test piece.
Subsequently, the haze of the reference test piece and the test piece was measured using a haze meter [trade name: NDH-5000SP, Nippon Denshoku Industries Co., Ltd.]. If the increase in the haze value from the reference test piece to the test piece was less than 1.0, it was judged to be a (meth) acrylic resin emulsion capable of forming a film having excellent miscibility with calcium acetate and excellent transparency.

(3) Miscibility with amine salt The same operation as in the above "(1) Miscibility with aluminum phosphate" was performed to obtain a reference test piece.
Next, 5 parts by mass of (meth) acrylic resin emulsion, 10 parts by mass of Sunstat 2012A [trade name, Sanyo Chemical Industries, Ltd., amine salt] 50% by mass aqueous solution, and 1 part by mass of glycerin were weighed in a reagent bottle. The reagent bottle was shaken up and down 10 times. 150 parts by mass of deionized water was added to the liquid mixture obtained by shaking and mixed. The obtained liquid mixture was coated on the PET film piece prepared above using No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a test piece.
Subsequently, the haze of the reference test piece and the test piece was measured using a haze meter [trade name: NDH-5000SP, Nippon Denshoku Industries Co., Ltd.]. If the increase in the haze value from the reference test piece to the test piece was less than 1.0, it was judged that the emulsion was a (meth) acrylic resin emulsion that was excellent in miscibility with amine salts and could form a film with excellent transparency.

3. Solvent resistance A PET film [trade name: Lumirror (registered trademark) 125T60, biaxially stretched PET film, Toray Industries, Inc.] was cut into A4 size to prepare a PET film piece. The haze of the prepared PET film piece was measured using a haze meter [trade name: NDH-5000SP, Nippon Denshoku Industries Co., Ltd.]. As a result, the haze value of the PET film piece was 2.9.
Next, the (meth) acrylic resin emulsion was diluted with deionized water so that the solid content concentration was 2.2% by mass. The obtained diluted solution was applied onto the PET film piece whose haze value was measured in advance using No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a test piece. One drop of ethyl acetate was dropped on the film surface of the obtained test piece, and after 1 second, the dripped ethyl acetate was stretched on the film surface while gently rubbing with a waste cloth.
Next, the portion of the film surface of the test piece on which the ethyl acetate was dropped and the stretched portion (hereinafter collectively referred to as “test portion”) were visually observed, and the solvent resistance of the film was evaluated according to the following evaluation criteria. did.
The (meth) acrylic resin emulsion capable of forming a film having excellent solvent resistance is classified as “A”. In addition, when the film | membrane formed is excellent in solvent resistance, it is thought that the transparency of a film | membrane is hard to be impaired.

-Evaluation criteria-
A: No change is observed in the test part.
B: In the test portion, at least one of exposure of the PET film and scratches are observed.

4). Evaluation with Foam Resistance (1) (Meth) Acrylic Resin Emulsion The (meth) acrylic resin emulsion was diluted with deionized water to a solid content concentration of 10.0% by mass. 30 mL of the obtained diluted solution was weighed out into a 200 mL measuring cylinder [Shibada Chemical Co., Ltd.]. The opening of the graduated cylinder was sealed with a wrap film so that the diluent did not leak, and then the graduated cylinder was vigorously shaken for 15 seconds. The total volume of the liquid and foam immediately after shaking was measured by reading the scale of the graduated cylinder, and the foam resistance of the (meth) acrylic resin emulsion was evaluated according to the following evaluation criteria.
In the following evaluation criteria, the most excellent one is “A”.

-Evaluation criteria-
A: The total volume of liquid and foam is 100 mL or less.
B: The total volume of liquid and foam is more than 100 mL and less than 200 mL.
C: The total volume of liquid and foam is 200 mL or more.

(2) Evaluation by membrane A PET film [trade name: Lumirror (registered trademark) 125T60, biaxially stretched PET film, Toray Industries, Inc.] was cut into A4 size to prepare a PET film piece.
The (meth) acrylic resin emulsion was then diluted 3 times with deionized water. 30 mL of the obtained diluted solution was weighed out into a 200 mL measuring cylinder [Shibada Chemical Co., Ltd.]. The opening of the graduated cylinder was sealed with a wrap film so that the diluent did not leak, and then the graduated cylinder was vigorously shaken for 15 seconds.
Next, the diluted solution one minute after shaking was applied onto the PET film piece prepared above using a No. 2 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. . The formed coating film was heated at 100 ° C. for 60 seconds and dried to obtain a test piece. The test piece was visually observed, and the foam resistance of the formed film was evaluated according to the following evaluation criteria.
In the following evaluation criteria, the most excellent one is “A”.

-Evaluation criteria-
A: No defects are observed on the test piece.
B: 1 or more and 19 or less defects are seen in the test piece.
C: 20 or more defects are observed in the test piece.

5. Stretch resistance A PET film [trade name: PT700M, unstretched PET film, RP Topura Co., Ltd.] was cut into a size of 5 cm × 10 cm to prepare a PET film piece (haze value: 0.3).
Next, the (meth) acrylic resin emulsion was diluted with deionized water so that the solid content concentration was 5.0% by mass. The obtained diluted solution was applied onto the PET film piece prepared above using a No. 3 bar coater [Daiichi Rika Co., Ltd.] to form a coating film. The formed coating film was heated at 90 ° C. for 30 seconds and dried to obtain a test piece A. The haze (namely, haze before extending | stretching) of the center part of the test piece A was measured using the haze meter [Brand name: NDH-5000SP, Nippon Denshoku Industries Co., Ltd.].
Next, the test piece A was heated at 95 ° C. for 10 seconds (so-called preheating) and then stretched three times at a speed of 1000 mm / min under the condition of 95 ° C. to obtain a test piece B. The haze (namely, haze after extending | stretching) of the extending | stretching part of the test piece B was measured using the haze meter.
It was judged that it was a (meth) acrylic resin emulsion capable of forming a film having excellent stretch resistance as the increase in haze value of the test piece before and after stretching was small.

As shown in Table 3, each of the (meth) acrylic resin emulsions of Examples 1 to 17 could form a film having excellent transparency. The (meth) acrylic resin emulsions of Examples 1 to 17 are all excellent in miscibility with additives (aluminum phosphate, calcium acetate, and amine salt), and are transparent even when mixed with additives. It was possible to form an excellent film. Furthermore, the film | membrane formed with the (meth) acrylic resin emulsion of Example 1- Example 17 was excellent in solvent resistance.
Moreover, since the (meth) acrylic resin emulsions of Examples 1 to 17 were excellent in foaming resistance, it was found that the formed film hardly caused defects due to foaming and the transparency was not easily impaired. . Furthermore, the film | membrane formed with the (meth) acrylic resin emulsion of Example 1- Example 17 was excellent in stretch resistance.

On the other hand, as shown in Table 4, the film formed of the (meth) acrylic resin emulsion of Comparative Example 1 in which the average particle diameter of the resin particles exceeds 100 nm is an example in which the average particle diameter of the resin particles is 100 nm or less. It was inferior to transparency compared with the film | membrane formed with the (meth) acrylic resin emulsion (for example, Example 1).
Instead of the structural unit (C) derived from the anionic reactive surfactant and the structural unit (D) derived from the nonionic reactive surfactant, the structural unit and nonion derived from the anionic nonreactive surfactant The (meth) acrylic resin emulsion of Comparative Example 2 containing resin particles having a structural unit derived from a type non-reactive surfactant is miscible with any additive of aluminum phosphate, calcium acetate, and amine salt It was bad and a film excellent in transparency could not be formed. Moreover, the (meth) acrylic resin emulsion of Comparative Example 2 was inferior in foam resistance.
Instead of the structural unit (D) derived from the nonionic reactive surfactant, the resin of Comparative Example 3 containing particles of a resin having a structural unit derived from a nonionic reactive surfactant other than the structural unit (D) ( The (meth) acrylic resin emulsion has poor miscibility with any of the additives of aluminum phosphate, calcium acetate, and amine salt, and could not form a film with excellent transparency.

The (meth) acrylic resin emulsion of Comparative Example 4 containing resin particles not having the structural unit (D) derived from the nonionic reactive surfactant is poorly miscible with calcium acetate and miscible with amine salts. A film excellent in transparency could not be formed.
The (meth) acrylic resin emulsion of Comparative Example 5 containing resin particles having a structural unit derived from a nonionic non-reactive surfactant instead of the structural unit derived from a nonionic reactive surfactant (D) is , Aluminum phosphate, calcium acetate, and amine salts were not miscible with the additives, and a film having excellent transparency could not be formed.
A structural unit derived from a nonionic reactive surfactant and having a structural unit derived from an anionic non-reactive surfactant instead of the structural unit (C) derived from an anionic reactive surfactant The (meth) acrylic resin emulsion of Comparative Example 6 containing resin particles not having (D) is poorly miscible with any additive of aluminum phosphate, calcium acetate, and amine salt, and has excellent transparency Could not be formed. Moreover, the (meth) acrylic resin emulsion of Comparative Example 6 was inferior in foam resistance.

The (meth) acrylic of Comparative Example 7 in which the average addition mole number of the oxyethylene group possessed by the nonionic reactive surfactant is the same as the average addition mole number of the oxyethylene group possessed by the anionic reactive surfactant The resin emulsion was poorly miscible with calcium acetate and with the amine salt, and could not form a film with excellent transparency.
The (meth) acrylic resin emulsion of Comparative Example 8 has an average addition mole number of oxyethylene groups that the nonionic reactive surfactant has is smaller than an average addition mole number of oxyethylene groups that the anionic reactive surfactant has. , Aluminum phosphate, calcium acetate, and amine salts were not miscible with the additives, and a film having excellent transparency could not be formed.

The film | membrane formed with the (meth) acrylic resin emulsion of the comparative example 9 which does not have the structural unit (B) derived from the monomer which has a methylol group in the particle | grains of resin is the structure derived from the monomer which has a methylol group Compared with the example (for example, Example 1) which has a unit (B), it was inferior to solvent resistance.
From the result of Comparative Example 10, in the resin particles not having the structural unit (A) derived from the (meth) acrylic monomer having at least one functional group selected from a carboxy group and a hydroxyl group, the average particle diameter is 100 nm. It turned out to be difficult to: The film formed of the (meth) acrylic resin emulsion of Comparative Example 10 in which the average particle diameter of the resin particles exceeds 100 nm is (Example 1 (for example 1)) in which the average particle diameter of the resin particles is 100 nm or less. Compared with the film | membrane formed with the (meth) acrylic resin emulsion, it was inferior to transparency.
From the comparison between Comparative Example 9 and Comparative Example 11 and Comparative Example 12, when the (meth) acrylic resin emulsion contains particles of a resin having a structural unit derived from a monomer having an aromatic ring, the resistance of the formed film It was found that stretchability was lowered.

Claims (4)

A structural unit (A) derived from a (meth) acrylic monomer having at least one functional group selected from a carboxy group and a hydroxyl group; a structural unit (B) derived from a monomer having a methylol group; The structural unit (C) derived from the anionic reactive surfactant having a saturated double bond and an oxyethylene group, and the average added mole number of the oxyethylene group represented by the following formula (1) Resin having a structural unit (D) derived from a nonionic reactive surfactant having an average number of moles of oxyethylene groups added to the reactive surfactant, and having an average particle size of 10 nm to 100 nm Particles of
An aqueous medium;
(Meth) acrylic resin emulsion for forming primer layer.

[In Formula (1), Y represents the substituent represented by following formula (2). m represents an integer of 1 to 3. n represents the average addition mole number of an oxyethylene group, and represents an integer of 8 to 100. ]
The (meth) acrylic resin emulsion for forming a primer layer according to claim 1, wherein the anionic reactive surfactant is an anionic reactive surfactant represented by the following formula (3).

Wherein (3), X _is -SO 3 represents M, -COOM, or a -PO ₃ M, M represents an alkali metal atom, an alkaline earth metal atom, or an ammonium group. p represents an integer of 1 to 3. q represents the average addition mole number of an oxyethylene group, and represents the integer of 5-40. ]   The primer layer-forming (meth) acrylic resin emulsion according to claim 1 or 2, wherein the resin has a glass transition temperature of 0 ° C or higher.   The content of the structural unit derived from the monomer having an aromatic ring in the resin is derived from a reactive surfactant containing the structural unit of the resin (however, the structural unit (C) and the structural unit (D)). The (meth) acrylic resin emulsion for forming a primer layer according to any one of claims 1 to 3, wherein the content is 20.0% by mass or less based on the total mass of the structural unit.