WO2021166602A1

WO2021166602A1 - Resin composition for coating polyolefin substrate

Info

Publication number: WO2021166602A1
Application number: PCT/JP2021/003349
Authority: WO
Inventors: 広晃小川; 彰啓坂口; 樹福田
Original assignee: 日本カーバイド工業株式会社
Priority date: 2020-02-18
Filing date: 2021-01-29
Publication date: 2021-08-26
Also published as: KR20220139990A; CN115052942A; JP2021130753A; JP7372170B2; CN115052942B; TW202138496A

Abstract

This resin composition for coating a polyolefin substrate contains: an isocyanate-based crosslinking agent; water; and particles of a resin which contains constituent units (A) derived from a (meth)acrylic monomer having a group that contains at least one of a branched structure and an alicyclic structure, constituent units (B) derived from a monomer having at least one of a carboxyl group and a hydroxyl group, and constituent units (C) derived from a non-ionic reactive surfactant having a hydroxyl group, an oxyalkylene group and an ethylenically unsaturated double bond. The particles of a resin are configured so that the content of the constituent unit (A) is 65 mass% or more relative to the total amount of constituent units other than constituent units derived from the reactive surfactant. The ratio of the number of moles of isocyanate groups in the isocyanate-based crosslinking agent relative to the total number of moles of carboxyl groups and hydroxyl groups in the resin is 0.30 or more.

Description

Resin composition for polyolefin substrate coating

The present disclosure relates to a resin composition for coating a polyolefin base material.

Polyolefins typified by polypropylene have high transparency and color development, light specific gravity, strength, and excellent processability, so that they can be used in everyday products (for example, stationery, home appliances, and various packaging materials). It is often used. Further, a polyolefin film (hereinafter, also referred to as "polyolefin base material") is widely used after being laminated with various functional layers such as a protective coating layer and a printing layer on the surface thereof, and further molded. However, since the polyolefin base material is generally inferior in adhesion to the functional layer, the polyolefin base material is generally subjected to surface treatment such as corona treatment, or a primer layer or the like is coated between the polyolefin base material and the functional layer. By providing a layer, the adhesion between the polyolefin substrate and various functional layers is improved.

The coating layer provided between the polyolefin base material and the functional layer is required to have both adhesion to the polyolefin base material and adhesion to various functional layers (hereinafter, also referred to as "easy adhesion"). Be done. Various methods for improving the adhesion to the polyolefin substrate and the method for improving the easy adhesion to various functional layers have been reported so far.

For example, as a coating agent capable of improving the adhesion to a polyolefin substrate, a solvent-based coating composition containing a hydroxyl group-containing acrylic resin (I) and a polyisocyanate compound (II) showing an SP value in a specific range has been reported. (For example, refer to JP-A-2015-052078).
Further, for example, a coating composition containing an oxazoline group-modified resin has been reported as a coating agent capable of improving easy adhesion to a functional layer (see, for example, Japanese Patent Application Laid-Open No. 2001-150612).

Conventionally, solvent-based coating agents have been widely used for polyolefin substrates from the viewpoints of easy drying even at low temperatures and for a short time, and easy smoothing of the film thickness after drying. However, in recent years, with the regulation of VOC (Volatile Organic Compounds) and the enforcement of the recycling law, consideration for the environment has been required, and the use of an aqueous coating agent containing no organic solvent is recommended.

On the other hand, a water-based coating agent containing an emulsion resin (for example, an acrylic emulsion resin) is widely used as a polyethylene terephthalate (PET) base material. The emulsion resin is generally produced by an emulsion polymerization method, and a surfactant is used in the production process. This surfactant may bleed out to the surface of the coating layer over time after the formation of the coating layer, which may cause deterioration of adhesion to the PET substrate and easy adhesion to the functional layer. The bleed-out of the surfactant can be suppressed, for example, by forming a strong crosslinked structure in the coating layer. However, when an aqueous coating agent containing an emulsion resin is applied to the polyolefin base material, unlike the PET base material, the polyolefin base material exhibits thermoplasticity in a low temperature region, so that sufficient heat cannot be applied. Therefore, it is difficult to provide a coating layer having a strong crosslinked structure formed by a thermosetting reaction on the surface of the polyolefin base material, and it is considered that bleed-out of the surfactant cannot be suppressed.

An object to be solved by one embodiment of the present disclosure is to provide a resin composition for coating a polyolefin base material, which can form a film having excellent adhesion to a polyolefin base material and easy adhesion to a functional layer.

Specific means for solving the above problems include the following aspects.
<1> Derived from a structural unit (A) derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and a monomer having at least one of a carboxy group and a hydroxyl group. The above-mentioned structural unit (A) includes a structural unit (B) to be formed, a hydroxyl group, an oxyalkylene group, and a structural unit (C) derived from a nonionic reactive surfactant having an ethylenically unsaturated double bond. The content of is the total structural unit [however, the structural unit derived from the reactive surfactant is excluded. ] With respect to 65% by mass or more of the resin particles,
Isocyanate cross-linking agent and
Contains water,
The ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin (that is, the number of moles of isocyanate groups in the isocyanate-based cross-linking agent / carboxy groups in the resin. And the total number of moles of hydroxyl groups) is 0.30 or more, which is a resin composition for coating a polyolefin base material.
<2> The above-mentioned isocyanate-based cross-linking agent is at least one selected from the group consisting of an water-dispersed isocyanate-based cross-linking agent and a blocked isocyanate-based cross-linking agent having a dissociation temperature of 100 ° C. or lower. Resin composition for coating a polyolefin substrate.
<3> The resin composition for coating a polyolefin base material according to <1> or <2>, wherein the average number of moles of the oxyalkylene group added in the nonionic reactive surfactant is in the range of 5 or more and 40 or less.
<4> The polyolefin according to any one of <1> to <3>, wherein the (meth) acrylic monomer having a group containing the branched structure is at least one of i-butyl methacrylate and t-butyl acrylate. Resin composition for substrate coating.
<5> The resin composition for coating a polyolefin base material according to any one of <1> to <4>, wherein the (meth) acrylic monomer having a group containing the alicyclic structure is cyclohexyl methacrylate.
<6> The resin composition for coating a polyolefin base material according to any one of <1> to <5>, wherein the structural unit (B) contains a structural unit derived from N-methylolacrylamide.
<7> The nonionic reactive surfactant having the hydroxyl group, the oxyalkylene group, and the ethylenically unsaturated double bond is the nonionic reactive surfactant represented by the following formula (1) <1>. The resin composition for coating a polyolefin base material according to any one of <6>.

In the formula (1), R ^1b represents an aliphatic alkyl group having 6 to 24 carbon atoms, and X ^1b represents a hydrogen atom. n3 represents the average number of moles of oxyethylene groups added and represents an integer of 5 to 50.

<8> The content of the structural unit (B) in the resin is the total structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], The resin composition for coating a polyolefin base material according to any one of <1> to <7>, which is in the range of 1% by mass or more and 10% by mass or less.
<9> The content of the structural unit (C) in the resin is the structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], The resin composition for coating a polyolefin base material according to any one of <1> to <8>, which is in the range of 4.9 parts by mass or more and 27.5 parts by mass or less with respect to a total of 100 parts by mass.

According to one embodiment of the present disclosure, there is provided a resin composition for coating a polyolefin base material, which can form a film having excellent adhesion to a polyolefin base material and easy adhesion to a functional layer.

Hereinafter, specific embodiments of the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the purpose of the present disclosure.

The numerical range indicated by using "-" in the present disclosure means a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.
In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.
In the present disclosure, the amount of each component means the total amount of a plurality of kinds of substances when a plurality of kinds of substances corresponding to each component are present, unless otherwise specified.

In the present disclosure, "(meth) acrylic" is a term that includes both "acrylic" and "methacrylic", and "(meth) acrylate" is a term that includes both "acrylate" and "methacrylate". "(Meta) acryloyl" is a term that includes both "acryloyl" and "methacrylic".

In the present disclosure, the "(meth) acrylic monomer" means a monomer having a (meth) acryloyl group.
The "monomer" in the present disclosure does not include a reactive surfactant.

In the present disclosure, "n-" means normal, "i-" means iso, "s-" means secondary, and "t-" means tertiary.

In the present disclosure, the term "process" is included in this term not only as an independent process but also as long as the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. ..

[Resin composition for coating a polyolefin base material]
The resin composition for coating a polyolefin base material of the present disclosure (hereinafter, also simply referred to as “resin composition”) is a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure. Nonionic reaction having a derived structural unit (A), a structural unit (B) derived from a monomer having at least one of a carboxy group and a hydroxyl group, a hydroxyl group, an oxyalkylene group, and an ethylenically unsaturated double bond. A structural unit (C) derived from a sex surfactant (hereinafter, also referred to as “specific nonionic reactive surfactant”) is included, and the content of the structural unit (A) is the total structural unit [however. , Excludes structural units derived from reactive surfactants. ] With respect to 65% by mass or more of the resin particles,
Isocyanate cross-linking agent and
Contains water,
The ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin is 0.30 or more.

The resin composition of the present disclosure is used for coating a polyolefin substrate. The resin composition of the present disclosure has a structural unit (A) derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and at least one of a carboxy group and a hydroxyl group. It contains a structural unit (B) derived from a monomer and a structural unit (C) derived from a specific nonionic reactive surfactant, and the content of the structural unit (A) is the total structural unit [however, Excludes structural units derived from reactive surfactants. ], The resin particles in an amount of 65% by mass or more are dispersed in a medium containing an isocyanate-based cross-linking agent and water.
In the present disclosure, "all structural units [excluding structural units derived from reactive surfactants]" means all structural units of the resin other than those derived from reactive surfactants. It means a structural unit, and the structural unit derived from this reactive surfactant includes a structural unit derived from all reactive surfactants, that is, a structural unit derived from a specific nonionic reactive surfactant (C). ), And a structural unit derived from a reactive surfactant other than the specific nonionic reactive surfactant.

According to the resin composition of the present disclosure, it is possible to form a film having excellent adhesion to a polyolefin substrate and easy adhesion to a functional layer.
The reason why the resin composition of the present disclosure can exert such an effect is not clear, but the present inventors speculate as follows. However, the following speculation does not limit the interpretation of the resin composition of the present disclosure, but is described as an example.

The resin composition of the present disclosure contains resin particles containing a structural unit (C) derived from a specific nonionic reactive surfactant, and the resin constituting the resin particles includes a specific nonionic reactive surfactant. Is strongly chemically bonded to a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and a monomer having at least one of a carboxy group and a hydroxyl group. Therefore, the bleed-out of the surfactant to the film surface is suppressed. Therefore, in the film formed by the resin composition of the present disclosure, it is unlikely that the adhesion to the polyolefin substrate and the easy adhesion to the functional layer are lowered due to the bleed-out of the surfactant to the film surface. Conceivable.
Further, the resin composition of the present disclosure contains a resin particle and an isocyanate-based cross-linking agent, and the resin constituting the resin particle has a group containing at least one of a branched structure and an alicyclic structure. Derived from a structural unit (A) derived from a (meth) acrylic monomer, a structural unit (B) derived from a monomer having at least one of a carboxy group and a hydroxyl group, and a specific nonionic reactive surfactant. Includes the structural unit (C).
Therefore, in the film formed by the resin composition of the present disclosure, the isocyanate group of the isocyanate-based cross-linking agent is at least one of the carboxy group and the hydroxyl group in the structural unit (B), and the hydroxyl group in the structural unit (C). Then, a cross-linking reaction is carried out to form a strong cross-linked structure. Further, although the detailed mechanism is unknown, a group containing at least one of the branched structure and the alicyclic structure in the structural unit (A) acts on the formation of the membrane. Therefore, it is considered that the film formed by the resin composition of the present disclosure has excellent adhesion to the polyolefin substrate.
Further, in the film formed by the resin composition of the present disclosure, a crosslinked structure containing a specific ratio or more of the constituent unit (A), the constituent unit (B), and the constituent unit (C) is formed, and the crosslinked structure is formed. By cross-linking the isocyanate group of the isocyanate-based cross-linking agent with the hydroxyl group in the structural unit (C), the affinity with the functional layer such as the UV (ultraviolet) ink layer and the hard coat layer is improved. Therefore, it is considered that the film formed by the resin composition of the present disclosure is excellent in easy adhesion to the functional layer.
From the above, it is presumed that the film formed by the resin composition of the present disclosure is excellent in adhesion to a polyolefin substrate and easy adhesion to a functional layer.

Hereinafter, each component of the resin composition of the present disclosure will be described.

[Resin particles]
The resin composition of the present disclosure has a structural unit (A) derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and at least one of a carboxy group and a hydroxyl group. Derived from the monomer-derived structural unit (B) and a nonionic reactive surfactant having a hydroxyl group, an oxyalkylene group, and an ethylenically unsaturated double bond (that is, a specific nonionic reactive surfactant). The constituent unit (C) is included, and the content of the constituent unit (A) is the total constituent unit [however, the constituent unit derived from the reactive surfactant is excluded. ], The resin particles are contained in an amount of 65% by mass or more.
First, the constituent units of the resin constituting the resin particles will be described.

<Structural unit (A)>
The resin contains a structural unit (A) derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure.
The structural unit (A) contributes to the improvement of the adhesion of the film formed by the resin composition of the present disclosure to the polyolefin base material and the improvement of the easy adhesion to the functional layer (particularly, the UV ink layer).

In the present disclosure, "a structural unit derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure" includes at least one of the branched structure and the alicyclic structure. It means a structural unit formed by addition polymerization of a (meth) acrylic monomer having a group.
The "(meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure" in the present disclosure includes a monomer having at least one of a carboxy group and a hydroxyl group, which will be described later. I can't.

The structural unit (A) may be a structural unit derived from a (meth) acrylic monomer having a group containing only a branched structure among the branched structure and the alicyclic structure, and a group containing only the alicyclic structure may be used. It may be a structural unit derived from a (meth) acrylic monomer having a group, or may be a structural unit derived from a (meth) acrylic monomer having a group containing both a branched structure and an alicyclic structure.

The type of (meth) acrylic monomer having a group containing a branched structure is not particularly limited.
As the (meth) acrylic monomer having a group containing a branched structure, a (meth) acrylic acid alkyl ester monomer in which the group containing a branched structure is a branched-chain alkyl group is preferable.
Specific examples of the (meth) acrylic monomer having a group containing a branched structure include i-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, and i-octyl (meth). Examples thereof include acrylate, 2-ethylhexyl (meth) acrylate, and i-nonyl (meth) acrylate.
Among these, as the (meth) acrylic monomer having a group containing a branched structure, at least one of i-butyl methacrylate and t-butyl acrylate is preferable, i-butyl methacrylate or t-butyl acrylate is more preferable, and t-butyl acrylate is more preferable. -Butyl acrylate is more preferred.

The type of (meth) acrylic monomer having a group containing an alicyclic structure is not particularly limited.
As the (meth) acrylic monomer having a group containing an alicyclic structure, a (meth) acrylic acid alkyl ester monomer is preferable.
Specific examples of the (meth) acrylic monomer having a group containing an alicyclic structure include cyclohexyl (meth) acrylate and isobornyl (meth) acrylate.
Among these, cyclohexyl methacrylate is preferable as the (meth) acrylic monomer having a group containing an alicyclic structure.

The resin may contain only one type of the structural unit (A), or may contain two or more types of the resin.
Further, the resin may contain, for example, only the structural unit derived from the (meth) acrylic monomer having a group containing a branched structure as the structural unit (A), and has a group containing an alicyclic structure (). It may contain only a structural unit derived from a (meth) acrylic monomer, and has a (meth) structural unit derived from a branched structure and a group containing an alicyclic structure (meth). It may contain both structural units derived from the acrylic monomer.

The content of the structural unit (A) in the resin is the total structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], It is preferably in the range of 65% by mass or more, 65% by mass or more and 98.5% by mass or less, more preferably 67% by mass or more and 98.5% by mass or less, 69. It is more preferably in the range of mass% or more and 98.5 mass% or less.
The content of the structural unit (A) in the resin is the total structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], The resin composition of the present disclosure tends to be able to form a film having excellent adhesiveness to a functional layer (particularly, a UV ink layer).

<Structural unit (B)>
The resin contains a structural unit (B) derived from a monomer having at least one of a carboxy group and a hydroxyl group.
The carboxy group and the hydroxyl group in the structural unit (B) can undergo a cross-linking reaction with the isocyanate group of the isocyanate-based cross-linking agent described later to form a cross-linked structure.

In the present disclosure, "a structural unit derived from a monomer having at least one of a carboxy group and a hydroxyl group" means a structural unit formed by addition polymerization of a monomer having at least one of a carboxy group and a hydroxyl group. do.

The structural unit (B) may be a structural unit derived from a monomer having only a carboxy group among carboxy groups and hydroxyl groups, or may be a structural unit derived from a monomer having only a hydroxyl group. , A structural unit derived from a monomer having both a carboxy group and a hydroxyl group.
For example, from the viewpoint of improving the easy adhesion to the functional layer, the structural unit (B) is preferably a structural unit derived from a monomer having at least a hydroxyl group.

The type of monomer having a carboxy group is not particularly limited.
Specific examples of the monomer having a carboxy group include acrylic acid, methacrylic acid, succinic acid, maleic anhydride, fumaric acid, itaconic acid, glutaconic acid, citraconic acid, and ω-carboxy-polycaprolactone mono (meth) acrylate [ For example, ω-carboxy-polycaprolactone (n≈2) monoacrylate], succinic acid ester (for example, 2-acryloyloxyethyl-succinic acid) and the like can be mentioned.
As the monomer having a carboxy group, a (meth) acrylic monomer is preferable, and at least one selected from acrylic acid and methacrylic acid is more preferable.

The type of monomer having a hydroxyl group is not particularly limited.
Specific examples of the monomer having a hydroxyl group include 2-hydroxymethyl (meth) acrylate, 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- Examples thereof include hydroxyhexyl (meth) acrylate, N- (hydroxymethyl) acrylamide [that is, N-methylol acrylamide (N-MAM)] and the like.
As the monomer having a hydroxyl group, N-methylolacrylamide is preferable.
When the resin contains a structural unit derived from N-methylolacrylamide as the structural unit (B), the resin composition of the present disclosure tends to be able to form a film having better adhesiveness to the functional layer.

The resin may have only one type of constituent unit (B), or may have two or more types of resin.
Further, for example, the resin may contain only the structural unit derived from the monomer having a carboxy group as the structural unit (B), or may contain only the structural unit derived from the monomer having a hydroxyl group. It may contain both a structural unit derived from a monomer having a carboxy group and a structural unit derived from a monomer having a hydroxyl group.

The content of the structural unit (B) in the resin is not particularly limited, but for example, all the structural units of the resin [however, the structural units derived from the reactive surfactant are excluded. ], It is preferably in the range of 1% by mass or more and 10% by mass or less, more preferably in the range of 1% by mass or more and 8% by mass or less, and in the range of 1.5% by mass or more and 7% by mass or less. Is more preferable.
The content of the structural unit (B) in the resin is the total structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ] On the other hand, when it is within the above range, the resin composition of the present disclosure tends to be able to form a film having better adhesiveness to the functional layer.

<Constituent units derived from other monomers>
The resin may contain a structural unit other than the structural unit derived from the above-mentioned monomer (so-called structural unit derived from other monomers) within the range in which the effects of the present disclosure are exhibited.

Examples of the structural unit derived from the other monomer include a (meth) acrylic acid alkyl ester monomer having none of a group containing a branched structure, a group containing an alicyclic structure, a carboxy group, and a hydroxyl group [hereinafter, , Also referred to as "specific (meth) acrylic acid alkyl ester monomer". )] Can be mentioned.

The number of carbon atoms of the alkyl group of the specific (meth) acrylic acid alkyl ester monomer is, for example, preferably in the range of 1 or more and 18 or less, more preferably in the range of 1 or more and 15 or less, and 1 or more and 12 or less. It is more preferable that the range is.

Specific examples of the specific (meth) acrylic acid alkyl ester monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, n-octyl (meth) acrylate, and n-nonyl (meth). ) Acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, stearyl (meth) acrylate, lauryl (meth) acrylate and the like.

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

When the resin contains structural units derived from other monomers, the content of the structural units derived from other monomers in the resin is not particularly limited and can be appropriately set according to the purpose.

<Structural unit (C)>
The resin contains a structural unit (C) derived from a nonionic reactive surfactant having a hydroxyl group, an oxyalkylene group, and an ethylenically unsaturated double bond (that is, a specific nonionic reactive surfactant).
The structural unit (C) contributes to the improvement of the adhesion of the film formed by the resin composition of the present disclosure to the polyolefin base material and the improvement of the easy adhesion to the functional layer.

In the present disclosure, the "constituent unit derived from the specific nonionic reactive surfactant" means a structural unit formed by addition polymerization of the specific nonionic reactive surfactant.

The specific nonionic reactive surfactant has a hydroxyl group.
The hydroxyl group in the structural unit (C) can undergo a cross-linking reaction with the isocyanate group of the isocyanate-based cross-linking agent described later to form a cross-linked structure.

The specific nonionic reactive surfactant has an oxyalkylene group.
Examples of the oxyalkylene group include an oxyethylene group, an oxypropylene group and an oxybutylene group.
As the oxyalkylene group, for example, an oxyethylene group is preferable from the viewpoint of high reactivity with a monomer. Further, since the oxyethylene group is more hydrophilic than, for example, an oxypropylene group or an oxybutylene group, a hydrated layer having a high density can be formed on the surface of the resin particles. The resin composition of the present disclosure is more homogeneous because the dispersibility of the resin particles in an aqueous medium such as water is further improved when the resin contains a structural unit derived from a reactive surfactant having an oxyethylene group. Shows a tendency to form a plastic film.

The average number of moles of the oxyalkylene group added is not particularly limited, but is preferably in the range of 5 or more and 50 or less, more preferably in the range of 5 or more and 40 or less, and in the range of 10 or more and 30 or less. Is even more preferable.
When the average number of moles of the oxyalkylene group added is 5 or more, the dispersibility of the resin particles in an aqueous medium such as water tends to be more excellent.
When the average number of moles of oxyalkylene groups added is 50 or less, the viscosity does not become excessively high when the resin composition of the present disclosure is produced, and the productivity tends to be improved.

The specific nonionic reactive surfactant has an ethylenically unsaturated double bond.
A nonionic reactive surfactant having an ethylenically unsaturated double bond can be obtained by imparting a group having an ethylenically unsaturated double bond to the nonionic reactive surfactant.
Specific examples of the group having an ethylenically unsaturated double bond include a (meth) acryloyl group, a vinyl group, an allyl group, an isopropenyl group, a 1-propenyl group, an allyloxy group, a styryl group and the like.
As the group having an ethylenically unsaturated double bond, for example, a 1-propenyl group is preferable from the viewpoint of high reactivity with a monomer.

The type of the specific nonionic reactive surfactant is not particularly limited as long as it has a hydroxyl group, an oxyalkylene group, and an ethylenically unsaturated double bond, but is represented by, for example, the following formula (1). It is preferably a nonionic reactive surfactant.

In the formula (1), R ^1b represents an aliphatic alkyl group having 6 to 24 carbon atoms, and X ^1b represents a hydrogen atom.
Further, in the formula (1), n3 represents the average number of moles of oxyethylene groups added (also referred to as "average number of repetitions of oxyethylene units"). n3 is an integer of 5 to 50, preferably an integer of 5 to 40, and more preferably an integer of 10 to 30.

As an example of a commercially available nonionic reactive surfactant represented by the formula (1), Adecaria Soap (registered trademark) ER-10 [active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether [Average number of moles added of oxyethylene group: 10], concentration of active ingredient: 100% by mass, ADEKA Corporation], ADEKA RIA SORP (registered trademark) ER-30 [active ingredient: polyoxyethylene-1- (allyloxy) Methyl) alkyl ether [average number of moles of oxyethylene group added: 30], active ingredient concentration: 65% by mass, ADEKA Corporation], ADEKA REASORP (registered trademark) ER-40 [active ingredient: polyoxyethylene-1 -(Allyloxymethyl) alkyl ether [average number of moles of oxyethylene group added: 40], active ingredient concentration: 60% by mass, ADEKA Corporation, and the like.

As specific nonionic reactive surfactants, Aqualon (registered trademark) AN-10 [average number of moles of oxyethylene group added: 10, Dai-ichi Kogyo Seiyaku Co., Ltd.], Aqualon (registered trademark) AN-30. Commercial products such as [Average number of moles of oxyethylene group added: 30, Dai-ichi Kogyo Seiyaku Co., Ltd.] are also mentioned as suitable examples.

The resin may contain only one type of constituent unit (C), or may contain two or more types of resin.

The content of the structural unit (C) in the resin is not particularly limited, but for example, the structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], The range is preferably 4.9 parts by mass or more and 27.5 parts by mass or less, and more preferably 8.0 parts by mass or more and 24.0 parts by mass or less. It is more preferably in the range of 11.4 parts by mass or more and 21.6 parts by mass or less, and particularly preferably in the range of 11.4 parts by mass or more and 15.0 parts by mass or less.
The content of the constituent unit (C) in the resin is the constituent unit of the resin [however, the constituent unit derived from the reactive surfactant is excluded. ], When the total amount is 4.9 parts by mass or more, the resin composition of the present disclosure tends to be able to form a film having better adhesiveness to the functional layer.
The content of the constituent unit (C) in the resin is the constituent unit of the resin [however, the constituent unit derived from the reactive surfactant is excluded. ], When it is 27.5 parts by mass or less with respect to 100 parts by mass in total, the resin composition of the present disclosure tends to have better coatability on a polyolefin base material.

-Average particle size of resin particles-
The average particle size of the resin particles is not particularly limited, but is preferably in the range of 20 nm or more and 400 nm or less, more preferably in the range of 30 nm or more and 200 nm or less, and in the range of 40 nm or more and 150 nm or less. Is more preferable.
When the average particle size of the resin particles is 20 nm or more, the resin composition of the present disclosure tends to be more excellent in production suitability.
When the average particle size of the resin particles is 400 nm or less, the resin composition of the present disclosure tends to be more excellent in film-forming property.

In this disclosure, "average particle size of resin particles" is referred to as "New Experimental Chemistry Course 4 Basic Technology 3 Light (II)" edited by the Chemical Society of Japan, pp. 725-741 (July 20, 1976, Maruzen (July 20, 1976). It is a value measured by the dynamic light scattering method described in (Issued by Co., Ltd.). The specific method is as follows.
The resin composition was diluted with distilled water, thoroughly stirred and mixed, and then 5 mL was collected in a 10 mm square glass cell using a Pasteur pipette, and this was collected by a dynamic light scattering photometer [for example, MALVERN INSTRUMENT]. Set in the Zetasizer NANO-ZS90 (trade name)] of the company. After setting the set value of the attenuation rate (Attenuator) to x8 (8 times) and adjusting the concentration of the diluent of the resin composition so that the Count Rate of the attenuation rate is 150 kCps to 200 kCps, the measurement temperature is 25 ° C. ± The average particle size of the resin particles in the resin composition is obtained by computer-processing the results measured under the conditions of 1 ° C. and a light scattering angle of 90 °. Further, as the value of the average particle size, the value of the Z average is used.

-Resin glass transition temperature-
The glass transition temperature (Tg) of the resin is not particularly limited, but is preferably in the range of 0 ° C. or higher and 60 ° C. or lower, more preferably in the range of 10 ° C. or higher and 50 ° C. or lower, and is 20 ° C. or higher and 45 ° C. or higher. It is more preferably in the range of ° C. or lower.
In the present disclosure, the "glass transition temperature (Tg) of the resin" is a value measured by the following method using a differential scanning calorimetry (DSC).
The resin is applied onto the release paper using a 4 mil (101.6 μm) applicator. Then, the applied resin is dried at room temperature (that is, 25 ° C.) to obtain a dried product of the resin. The obtained dried product is used as a measurement sample. Next, 10 mg of the dried product, which is a measurement sample, was packed in an aluminum sample pan [trade name: Tzero Pan, TA Instruments], and an aluminum lid [trade name: Tzero Hermetic Lid, TA] was packed.・ After sealing with [Instrument], measure the glass transition temperature using a differential scanning calorimeter. The measurement conditions are shown below.
The measurement is performed twice for the same measurement sample, and the value obtained in the second measurement is adopted as the glass transition temperature of the resin.
As the differential scanning calorimetry, for example, a differential scanning calorimeter (trade name: DSC2500) manufactured by TA Instruments Co., Ltd. can be used.

-Measurement condition-
Atmospheric condition: Atmospheric measurement range: -50 ° C to 100 ° C
Temperature rise rate: 10 ° C / min Standard substance: Empty sample pan

-Resin particle content-
The content of the resin particles in the resin composition of the present disclosure is not particularly limited, but is, for example, in the range of 15% by mass or more and 50% by mass or less with respect to the total mass of the resin composition from the viewpoint of production stability. It is preferably in the range of 20% by mass or more and 45% by mass or less, and further preferably in the range of 25% by mass or more and 40% by mass or less.

[Isocyanate cross-linking agent]
The resin composition of the present disclosure contains an isocyanate-based cross-linking agent.
The isocyanate-based cross-linking agent contributes to the improvement of the adhesion of the film formed by the resin composition of the present disclosure to the polyolefin substrate and the improvement of the easy adhesion to the functional layer.
In the present disclosure, the "isocyanate-based cross-linking agent" refers to a compound having two or more isocyanate groups in the molecule (so-called polyisocyanate compound).

Examples of the polyisocyanate compound include aromatic polyisocyanate compounds such as xylylene diisocyanate (XDI), diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tolylene diisocyanate (TDI), hexamethylene diisocyanate (HMDI), pentamethylene diisocyanate (PDI), and the like. Examples thereof include aliphatic or alicyclic polyisocyanate compounds such as isophorone diisocyanate and hydrogenated additives of aromatic polyisocyanate compounds.
The polyisocyanate compound includes a dimer, a trimeric, or a pentamer of the polyisocyanate compound, an adduct of the polyisocyanate compound and a polyol compound such as trimethylolpropane, and a biuret of the polyisocyanate compound. And so on.

The isocyanate-based cross-linking agent is preferably at least one selected from the group consisting of an water-dispersed isocyanate-based cross-linking agent and a blocked isocyanate-based cross-linking agent having a dissociation temperature of 100 ° C. or lower.

In the present disclosure, the "water-dispersed isocyanate-based cross-linking agent" is an isocyanate-based cross-linking agent that can be dispersed in an aqueous medium such as water, and is dispersed in an aqueous medium such as water with an isocyanate group encapsulated. This means that the reactivity of the isocyanate group is suppressed, but when the aqueous medium volatilizes, the state in which the isocyanate group is contained is eliminated and the reactivity of the isocyanate group can be exhibited. do.

As the water-dispersible isocyanate-based cross-linking agent, a commercially available product can be used.
Examples of commercially available water-dispersible isocyanate-based cross-linking agents include "Takenate (registered trademark) WD-725" from Mitsui Chemicals, Inc., "Duranate (registered trademark) WL70-100" from Asahi Kasei Corporation, and Sumika. Examples thereof include "Baihijour (registered trademark) 302" of Cobestrourethane Co., Ltd.
These commercially available products are sold in a state where they are not dispersed in an aqueous medium such as water. In the production of the resin composition of the present disclosure, the resin composition of the present disclosure is first dispersed in an aqueous medium such as water by dilution or the like. , Preferably used.

In the present disclosure, the "blocked isocyanate-based cross-linking agent" means a compound having two or more blocked isocyanate groups in the molecule. The "blocked isocyanate group" usually means that the isocyanate group is protected by a blocking agent (so-called mask) to suppress the reactivity of the isocyanate group, but when heated, it is deprotected and activated. It means a group capable of producing an isocyanate group.

The blocked isocyanate-based cross-linking agent having a dissociation temperature of 100 ° C. or lower may be a commercially available one or one synthesized by a conventional method.

The resin composition of the present disclosure may contain only one type of isocyanate-based cross-linking agent, or may contain two or more types.

Ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin (that is, the number of moles of isocyanate groups in the isocyanate-based cross-linking agent / total number of carboxy groups and hydroxyl groups in the resin The number of moles) is 0.30 or more, more preferably 0.35 or more, further preferably 0.40 or more, further preferably 0.50 or more, and 0.60 or more. It is more preferably 0.75 or more, and particularly preferably 1.0 or more.
The resin composition of the present disclosure relates to a functional layer (particularly, a UV ink layer) when the number of moles of isocyanate groups in the isocyanate-based cross-linking agent / the total number of moles of carboxy groups and hydroxyl groups in the resin is 0.30 or more. It shows a tendency to form a film having excellent easy adhesion.
The upper limit of the ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin is not particularly limited. From the viewpoint that blocking after coating is more likely to be suppressed, it is preferably 9.0 or less.

The number of moles of isocyanate groups in the isocyanate-based cross-linking agent with respect to the total number of moles of carboxy groups and hydroxyl groups in the resin (that is, the number of moles of isocyanate groups in the isocyanate-based cross-linking agent / the total number of moles of carboxy groups and hydroxyl groups in the resin. ) Is calculated by the following formulas (1) to (3). In the following calculation formula, the number of moles of isocyanate groups in the isocyanate-based cross-linking agent is referred to as "NCO number of moles", and the total number of moles of carboxy groups and hydroxyl groups in the resin is referred to as "total number of moles of functional groups". do.

Number of moles of NCO (unit: mol / solid content of isocyanate-based cross-linking agent 100 g)
= [Content of isocyanate groups in isocyanate-based cross-linking agent (unit: mass%) / Solid content concentration of isocyanate-based cross-linking agent (unit: mass%) x Amount of isocyanate-based cross-linking agent (unit: g)] / Isocyanate Formulation amount of group (unit: g / mol) ... (1)

Total number of moles of functional groups (Unit: Monomer having mol / carboxy group, Monomer having hydroxyl group, and 100 g of total solid content of specific nonionic reactive surfactant)
= [Content rate of structural unit derived from monomer having carboxy group in resin (unit: mass%) / Molecular weight of structural unit derived from monomer having carboxy group (unit: g / mol) × carboxy Number of carboxy groups in the structural unit derived from the monomer having a group (valence)] + [Content rate of the structural unit derived from the monomer having a hydroxyl group in the resin (unit: mass%) / hydroxyl group Molecular weight of structural unit derived from the monomer having (unit: g / mol) × Number of hydroxyl groups (valent number) in the structural unit derived from the monomer having hydroxyl group] + [Specific nonionic reactivity in resin Content of constituent units derived from surfactant (unit: mass%) / molecular weight of constituent units derived from specific nonionic reactive surfactant (unit: g / mol) x specific nonionic reactive surfactant Number of hydroxyl groups in the derived structural unit (molecular weight)] ... (2)

Ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin = number of moles of NCO / number of moles of total functional groups ... (3)

〔water〕
The resin composition of the present disclosure contains water.
In the resin compositions of the present disclosure, water can function as a dispersion medium for the resin particles.
The water is not particularly limited, and examples thereof include purified water, distilled water, ion-exchanged water, and pure water.
The water content in the resin composition of the present disclosure is not particularly limited, but is, for example, in the range of 70% by mass or more and 98% by mass or less with respect to the total mass of the resin composition from the viewpoint of production stability. Is more preferable, and the range is more preferably 75% by mass or more and 95% by mass or less, and further preferably 80% by mass or more and 92% by mass or less.

[Aqueous medium other than water]
The resin composition of the present disclosure may contain an aqueous medium other than water.
Examples of the aqueous medium other than water include alcohol solvents.
The alcohol solvent is not particularly limited, and examples thereof include 1,3-diol monoisobutyrate and acetylene glycol.
When the resin composition of the present disclosure contains an aqueous medium other than water, it may contain only one type of aqueous medium other than water, or may contain two or more types.

When the resin composition of the present disclosure contains an aqueous medium other than water, the content of the aqueous medium other than water in the resin composition is not particularly limited, but for example, from the viewpoint of the drying property of the coating film, the resin composition It is preferably 3% by mass or less, and more preferably 0.7% by mass or more and 3% by mass or less, based on the total mass of the above.

[Other ingredients]
The resin composition of the present disclosure may contain components other than the components described above (so-called other components) as long as the effects of the present disclosure are not impaired.
Examples of other components include antioxidants, antistatic agents, pH adjusters, antifoaming agents, film-forming aids and the like.

-PH of resin composition-
The pH of the resin composition of the present disclosure is preferably 5.0 to 9.0 from the viewpoint of the dispersibility of the resin particles in an aqueous medium such as water.
The method for measuring the pH of the resin composition of the present disclosure is not particularly limited.
As the pH of the resin composition of the present disclosure, a value measured using a pH meter in an environment of 25 ° C. is adopted. As the pH meter, for example, LAQUA (trade name) manufactured by HORIBA, Ltd. can be preferably used. However, the pH meter is not limited to this.

[Use of resin composition]
The resin composition of the present disclosure is preferably used for coating a polyolefin base material.
The film formed by the resin composition of the present disclosure is excellent in adhesion to a polyolefin base material and easy adhesion to a functional layer, and can function as a so-called primer layer.
Examples of the functional layer include a UV ink layer, a hard coat layer, an adhesive layer, an anchor layer, a printing layer, a conductive layer, an antiglare layer, an antireflection layer, an antifouling layer and the like.
The functional layer is preferably a layer formed by using an acrylic material.
The functional layer formed by using the acrylic material tends to be more excellent in the easy adhesion to the film formed by the resin composition of the present disclosure.
The resin composition of the present disclosure is particularly suitable for applications of forming a film provided between a polyolefin base material and a functional layer using an acrylic material.

[Manufacturing method of resin composition]
The method for producing the resin composition of the present disclosure is not particularly limited as long as the above-mentioned resin composition can be produced.
As a method for producing the resin composition of the present disclosure, for example, the method for producing the resin composition of the present embodiment described below is preferable from the viewpoint that the above-mentioned resin composition can be easily produced.

The method for producing the resin composition of the present embodiment (hereinafter, also referred to as “the production method of the present embodiment”) has at least a branched structure and an alicyclic structure in the presence of a specific nonionic reactive surfactant and water. A step of polymerizing a (meth) acrylic monomer having a group containing at least one structure and a monomer having at least one of a carboxy group and a hydroxyl group to obtain resin particles (hereinafter, "emulsion polymerization step"). Also called.) Includes.

Hereinafter, each step in the production method of the present embodiment will be described, but the description of matters common to the above-mentioned resin composition, for example, details of the components contained in the resin composition will be omitted.

<Emulsion polymerization process>
The emulsion polymerization step involves a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure in the presence of a specific nonionic reactive surfactant and water, and a carboxy group and a hydroxyl group. The monomer having at least one of the above is polymerized, and the content of the structural unit (A) is the total structural unit [however, the structural unit derived from the reactive surfactant is excluded. ] Is a step of obtaining resin particles in an amount of 65% by mass or more.
Here, the structural unit (A) is the above-mentioned structural unit (A), that is, a structural unit derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure. Yes, the structural unit (C) means the above-mentioned structural unit (C), that is, a structural unit derived from a specific nonionic reactive surfactant.
In the emulsion polymerization step, a specific nonionic reaction is carried out with a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure and a monomer having at least one of a carboxy group and a hydroxyl group. Copolymerization with the sex surfactant gives resin particles with a hydrated layer formed on the surface of the specific nonionic reactive surfactant.

The polymerization method is not particularly limited, and examples thereof include the methods (1) to (3) shown below.
(1) A (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure in a reaction vessel equipped with a thermometer, a stirring rod, a reflux cooler, a dropping funnel, and the like. , A monomer having at least one of a carboxy group and a hydroxyl group, a specific nonionic reactive surfactant, and water are charged, the temperature inside the reaction vessel is raised, and then a polymerization initiator, a reducing agent, etc. are appropriately prepared. A method of advancing the emulsification polymerization reaction (so-called batch preparation method),
(2) At least a specific nonionic reactive surfactant and water were charged in a reaction vessel equipped with a thermometer, a stirring rod, a reflux cooler, a dropping funnel, etc., and the temperature inside the reaction vessel was raised. After that, a monomer component [a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and a monomer having at least one of a carboxy group and a hydroxyl group] is added dropwise. Then, a method of advancing the emulsion polymerization reaction by appropriately adding a polymerization initiator, a reducing agent, etc. (so-called monomer dropping method).
(3) A monomer component [a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and a monomer having at least one of a carboxy group and a hydroxyl group]. After emulsifying with at least a specific nonionic reactive surfactant and water in advance to obtain a pre-emulsion, the obtained pre-emulsion is used in a thermometer, a stirring rod, a reflux cooler, a dropping funnel, etc. A method (so-called emulsification monomer dropping method) in which a polymerization initiator, a reducing agent, or the like is appropriately added to the reaction vessel provided with the above to proceed with the emulsification polymerization reaction can be mentioned.
Among these, as the polymerization method, for example, the emulsified monomer dropping method of (3) above is preferable from the viewpoint of production stability.

The polymerization temperature is, for example, 50 ° C. to 80 ° C., preferably 50 ° C. to 70 ° C.
The polymerization time is, for example, 4 hours to 6 hours, preferably 5 hours to 6 hours.

The amount of the (meth) acrylic monomer having a group containing at least one of the branched structure and the alicyclic structure is 65 parts by mass or more and 65 parts by mass with respect to 100 parts by mass of the total amount of the monomers. The range is preferably 98.5 parts by mass or less, more preferably 67 parts by mass or more and 98.5 parts by mass or less, and 69 parts by mass or more and 98.5 parts by mass or less. More preferred.
When the amount of the (meth) acrylic monomer having a group containing at least one of the branched structure and the alicyclic structure is 65 parts by mass or more with respect to 100 parts by mass of the total amount of the monomers, the functional layer ( In particular, there is a tendency to be able to produce a resin composition capable of forming a film having excellent adhesiveness to a UV ink layer).

The amount of the monomer having at least one of a carboxy group and a hydroxyl group is not particularly limited, but may be, for example, in the range of 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total amount of the monomers. It is preferably in the range of 1 part by mass or more and 8 parts by mass or less, and further preferably in the range of 1.5 parts by mass or more and 7 parts by mass or less.
When the amount of the monomer having at least one of a carboxy group and a hydroxyl group is within the above range with respect to 100 parts by mass of the total amount of the monomers, a resin composition capable of forming a film having excellent adhesiveness to a functional layer can be formed. Tends to be able to manufacture.

The amount of the specific nonionic reactive surfactant used is not particularly limited, but is preferably in the range of 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the total amount of the monomers, and is preferably 8 parts by mass. It is more preferably in the range of 10 parts by mass or more and 40 parts by mass or less, and further preferably in the range of 10 parts by mass or more and 25 parts by mass or less.
When the amount of the specific nonionic reactive surfactant used is 5 parts by mass or more with respect to 100 parts by mass of the total amount of the monomers, a resin composition capable of forming a film having better adhesiveness to the functional layer can be produced. Tend.
When the amount of the specific nonionic reactive surfactant used is 50 parts by mass or less with respect to 100 parts by mass of the total amount of the monomers, a resin composition capable of forming a film having better adhesion to the polyolefin substrate can be produced. Tend.

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.

(Initiator)
As the polymerization initiator, any polymerization initiator that can be used for ordinary emulsion polymerization can be used without particular limitation.
Examples of the polymerization initiator include ammonium persulfate, sodium persulfate, persulfate represented by potassium persulfate, organic peroxide represented by t-butyl hydroperoxide and cumene hydroperoxide, and peroxide. Hydrogen is mentioned.
When a polymerization initiator is used in the emulsion polymerization step, only one type of polymerization initiator may be used, or two or more types may be used.

The polymerization initiator is used in a commonly used amount.
The amount of the polymerization initiator used is, for example, 0.1 part by mass to 2 parts by mass, preferably 0.3 parts by mass to 1.5 parts by mass, based on 100 parts by mass of the total amount of the monomer as a raw material. Is.

(Reducing agent)
In the emulsion polymerization step, a reducing agent may be used together with the above-mentioned polymerization initiator.
Reducing agents include sodium metabisulfite, sodium sulfite, sodium hydrogen sulfite, sodium pyrosulfite (also referred to as "sodium dibisulfite"), sodium hydroxymethanesulfite, sodium pyrophosphate, thioglycolic acid, sodium thiosulfite, ascorbin. Acids, tartrate acids, citric acid, glucose and the like can be mentioned.
When a reducing agent is used in the emulsion polymerization step, only one kind of reducing agent may be used, or two or more kinds of reducing agents may be used.

The reducing agent is used in commonly used amounts.
The amount of the reducing agent used is, for example, 0.1 part by mass to 2 parts by mass, preferably 0.2 parts by mass to 1.5 parts by mass, based on 100 parts by mass of the total amount of the monomer as a raw material. be.

<Other processes>
The production method of the present embodiment may include steps other than the emulsion polymerization step, if necessary.

In the production method of the present embodiment described above, the emulsion polymerization method is given as an example as a method for obtaining resin particles, but the method for obtaining resin particles in the present disclosure is limited to the above-mentioned emulsion polymerization method. Instead, for example, a method such as a suspension polymerization method or a seed polymerization method can also be used.

Hereinafter, the present disclosure will be described in more detail with reference to Examples. The present disclosure is not limited to the following examples as long as the gist is not exceeded.

The pH of the resin composition produced in this example was measured by the measurement method described above. Further, as the measuring device, the same measuring device as described as an example was used in the above-mentioned measuring method.

[Manufacturing of resin composition]
[Example 1]
In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 104.4 parts by mass of deionized water and "Aqualon (registered trademark) KH-10" [trade name, anionic reactive surfactant] The activator, active ingredient concentration: 99% by mass, 2.0 parts by mass of Daiichi Kogyo Seiyaku Co., Ltd.] were charged, and the temperature was raised to 57 ° C. while substituting nitrogen in the reaction vessel.
On the other hand, in another container, 98.2 parts by mass of deionized water and "Adecaria Soap (registered trademark) ER-30" [trade name, specific nonionic reactive surfactant, average number of moles of oxyethylene group added. : 30, Active ingredient concentration: 65% by mass, ADEKA Co., Ltd.] 17.6 parts by mass (11.44 parts by mass as active ingredient amount) and "Aqualon (registered trademark) KH-10" [trade name, anion type Reactive surfactant, active ingredient concentration: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.] 3.0 parts by mass, and stirred, and then t-butyl acrylate (t-BA) [branched structure]. (Meta) acrylic monomer having a group containing 96.5 parts by mass, methacrylic acid (MAA) [monomer having a carboxy group] 1.5 parts by mass, and N-methylolacrylamide (N-MAM) A pre-emulsion was prepared by adding 2.0 parts by mass of [monomer having a hydroxyl group] and stirring.
Next, while maintaining the internal temperature of the reaction vessel at 57 ° C., an 8.0% by mass potassium persulfate aqueous solution [polymerization initiator] 2.5 parts by mass and a 6.4% by mass sodium disulfate aqueous solution [reducing agent] 2.5 parts by mass was added to initiate the emulsion polymerization reaction.
While maintaining the internal temperature of the reaction vessel at 57 ° C., the pre-emulsion prepared above was added uniformly and sequentially over 3 hours, and 1.0% by mass of a 1.0% by mass potassium persulfate aqueous solution [polymerization initiator] 20.75% by mass. Parts and 0.8% by mass of an aqueous sodium disulfide solution [reducing agent] 20.75 parts by mass were uniformly added sequentially over 3 hours and 30 minutes, and emulsion polymerization was carried out. After completion of the sequential addition, the obtained emulsion polymer was aged at 57 ° C. for 30 minutes and then cooled to room temperature to obtain a resin-containing solution.
Next, in the obtained resin-containing solution, "Takenate (registered trademark) WD-725" [trade name, water-dispersed isocyanate-based cross-linking agent, solid content concentration: 100% by mass, Mitsui Kagaku Co., Ltd.] was added to the deionized water. 45 parts by mass of the solution diluted 10-fold with (4.5 parts by mass as the solid content) and deionized water were added to adjust the solid content concentration to 11% by mass to obtain a resin composition. The pH of the obtained resin composition was 6.9.

The number of moles of isocyanate groups in the isocyanate-based cross-linking agent with respect to the total number of moles of carboxy groups and hydroxyl groups in the resin (that is, the number of moles of isocyanate groups in the isocyanate-based cross-linking agent / the total number of moles of carboxy groups and hydroxyl groups in the resin. ) Was obtained using the above-mentioned calculation formulas (1) to (3). The results are shown in Tables 1 and 2.
In Tables 1 and 2, "the number of moles of isocyanate groups in the isocyanate-based cross-linking agent" is referred to as "the number of moles of isocyanate groups in the isocyanate-based cross-linking agent (B)", and "the carboxy groups in the resin and the number of moles of the isocyanate groups (B)". The "total number of moles of hydroxyl groups" was expressed as "total number of moles of carboxy groups and hydroxyl groups in the resin (A)". Further, "the number of moles of isocyanate groups (B) in the isocyanate-based cross-linking agent / the total number of moles of carboxy groups and hydroxyl groups in the resin (A)" is expressed as "molar equivalent ratio [(B) / (A)". ..

For example, "the number of moles of isocyanate groups in the isocyanate-based cross-linking agent / the total number of moles of carboxy groups and hydroxyl groups in the resin" in the resin composition of Example 1 was specifically calculated as follows.
The isocyanate-based cross-linking agent "Takenate (registered trademark) WD-725" has an isocyanate group content of 15.96% by mass and a solid content concentration of 100% by mass, and has a blending amount (solid content conversion). The amount) is 4.5 g. The formula amount of the isocyanate group is 42 g / mol.
The molecular weight of methacrylic acid (MAA), which is a monomer having a carboxy group, is 86 g / mol. The content of the structural unit derived from methacrylic acid (MAA) in the resin is 1.5% by mass, and the number (valence) of carboxy groups in the structural unit derived from methacrylic acid (MAA) is It is 1.
The molecular weight of N-methylolacrylamide (N-MAM), which is a monomer having a hydroxyl group, is 101 g / mol. The content of the structural unit derived from N-methylolacrylamide (N-MAM) in the resin is 2.0% by mass, and the hydroxyl group in the structural unit derived from N-methylolacrylamide (N-MAM) The number (valence) is 1.
The molecular weight of "Adecaria Soap (registered trademark) ER-30", which is a specific nonionic reactive surfactant, is 1608 g / mol. The content of the structural unit derived from "Adecaria Soap (registered trademark) ER-30" in the resin is 11.44% by mass, which is derived from "Adecaria Soap (registered trademark) ER-30". The number of hydroxyl groups (valence) in the structural unit is 1.

Calculation formula (1)
Number of moles of NCO (unit: mol / solid content of isocyanate-based cross-linking agent 100 g)
= [Content of isocyanate groups in isocyanate-based cross-linking agent (unit: mass%) / Solid content concentration of isocyanate-based cross-linking agent (unit: mass%) x Amount of isocyanate-based cross-linking agent (unit: g)] / Isocyanate Formulation amount of group (unit: g / mol)
= [15.96 / 100 × 4.5 / 42]
= 0.017

Calculation formula (2)
Total number of moles of functional groups (Unit: Monomer having mol / carboxy group, Monomer having hydroxyl group, and 100 g of total solid content of specific nonionic reactive surfactant)
= [Content rate of structural unit derived from monomer having carboxy group in resin (unit: mass%) / Molecular weight of structural unit derived from monomer having carboxy group (unit: g / mol) × carboxy Number of carboxy groups in the structural unit derived from the monomer having a group (valence)] + [Content rate of the structural unit derived from the monomer having a hydroxyl group in the resin (unit: mass%) / hydroxyl group Molecular weight of structural unit derived from the monomer having (unit: g / mol) × Number of hydroxyl groups (valent number) in the structural unit derived from the monomer having hydroxyl group] + [Specific nonionic reactivity in resin Content of constituent units derived from surfactant (unit: mass%) / molecular weight of constituent units derived from specific nonionic reactive surfactant (unit: g / mol) x specific nonionic reactive surfactant Number of hydroxyl groups in the derived structural unit (molecular weight)]
= [1.5 / 86 × 1] + [2.0 / 101 × 1] + [11.44 / 1608 × 1]
= 0.017 + 0.020 + 0.007
= 0.044

Calculation formula (3)
Ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin = NCO moles / total functional group moles = 0.017 / 0.044
= 0.39

[Examples 2 to 13]
In Example 1, the same operation as in Example 1 was carried out except that the composition of the resin composition was changed to the composition shown in Table 1, to obtain a resin composition. The pH of the obtained resin composition was as follows.
Example 2 [pH: 6.9], Example 3 [pH: 8.0], Example 4 [pH: 8.9], Example 5 [pH: 8.6], Example 6 [pH: 6.3], Example 7 [pH: 7.7], Example 8 [pH: 6.9], Example 9 [pH: 7.1], Example 10 [pH: 7.4], Example Example 11 [pH: 7.1], Example 12 [pH: 6.9], Example 13 [pH: 6.2]

[Comparative Examples 1 to 3 and Comparative Examples 6 to 10]
In Example 1, the same operation as in Example 1 was carried out except that the composition of the resin composition was changed to the composition shown in Table 2, to obtain a resin composition. The pH of the obtained resin composition was as follows.
Comparative Example 1 [pH: 8.0], Comparative Example 2 [pH: 6.9], Comparative Example 3 [pH: 8.0], Comparative Example 6 [pH: 6.6], Comparative Example 7 [pH: 7.2], Comparative Example 8 [pH: 8.0], Comparative Example 9 [pH: 9.0], Comparative Example 10 [pH: 8.0]

[Comparative Example 4]
In Example 1, the same operation as in Example 1 was carried out except that the operation up to the preparation of the pre-emulsion was changed as follows, to obtain a resin-containing solution.
Next, deionized water was added to 50 parts by mass of the obtained resin-containing solution to adjust the solid content concentration to 11% by mass to obtain a resin composition. The pH of the obtained resin composition was 6.9.
"In a reaction vessel equipped with a thermometer, a stirring rod, a reflux condenser, and a dropping funnel, 121 parts by mass of deionized water and" Neoperex G-65 "[trade name, anionic non-reactive surfactant, Active ingredient concentration: 65% by mass, Kao Co., Ltd.] 1.55 parts by mass (1.01 parts by mass as the amount of active ingredient) was charged, and the temperature was raised to 57 ° C. while substituting nitrogen in the reaction vessel.
On the other hand, in another container, 41.6 parts by mass of deionized water and "Neoperex G-65" [trade name, anionic non-reactive surfactant, active ingredient concentration: 65% by mass, Kao Co., Ltd.] After adding 1.55 parts by mass (1.01 parts by mass as the amount of active ingredient) and stirring, a single amount of t-butyl acrylate (t-BA) [(meth) acrylic having a group containing a branched structure). Body] 96.5 parts by mass, methacrylic acid (MAA) [monomer having a carboxy group] 1.5 parts by mass, N-methylolacrylamide (N-MAM) [monomer having a hydroxyl group] 2.0 A pre-emulsion was prepared by adding parts by mass and stirring. "

[Comparative Example 5]
In Comparative Example 4, the same operation as in Comparative Example 4 was carried out except that the composition of the resin composition was changed to the composition shown in Table 2, to obtain a resin composition. The pH of the obtained resin composition was 7.8.

[Comparative Example 11]
In Example 1, the same operation as in Example 1 was performed except that the operation after obtaining the resin-containing solution was changed as follows, to obtain a resin-containing solution. The pH of the obtained resin composition was 6.9.
"Next, in the obtained resin-containing solution," Epocross (registered trademark) WS-500 "[trade name, oxazoline-based cross-linking agent, solid content concentration: 39% by mass, Nippon Catalyst Co., Ltd.] was added to 3 with deionized water. 37 parts by mass of the 9.-fold diluted solution (3.7 parts by mass as the solid content) and deionized water were added to adjust the solid content concentration to 11% by mass to obtain a resin composition. "

[Comparative Example 12]
In Example 1, the same operation as in Example 1 was performed except that the operation after obtaining the resin-containing solution was changed as follows, to obtain a resin-containing solution. The pH of the obtained resin composition was 6.9.
"Next, in the obtained resin-containing solution, add" Denacol (registered trademark) EX-810 "[trade name, epoxy-based cross-linking agent, solid content concentration: 100% by mass, Nagase ChemteX Corporation] with deionized water. 19 parts by mass of a 10-fold diluted solution (1.9 parts by mass as a solid content) and deionized water were added to adjust the solid content concentration to 11% by mass to obtain a resin composition. "

[measurement]
1. 1. Resin glass transition temperature (Tg)
The glass transition temperature of the resin was measured using each resin-containing solution obtained when each of the resin compositions of Examples 1 to 13 was produced. Specifically, the glass transition temperature of the resin was measured by the following method using a differential scanning calorimetry (DSC).
The resin-containing solution was applied onto the release paper using a 4 mil (101.6 μm) applicator. Then, the applied resin-containing solution was dried at room temperature (that is, 25 ° C.) to obtain a dried resin product. The obtained dried product was used as a measurement sample. Next, 10 mg of the dried product, which is a measurement sample, was packed in an aluminum sample pan [trade name: Tzero Pan, TA Instruments], and an aluminum lid [trade name: Tzero Hermetic Lid, TA] was packed. After sealing with [Instrument], the glass transition temperature was measured using a differential scanning calorimeter [trade name: DSC2500, TA Instruments]. The measurement conditions are shown below. The measurement was performed twice for the same measurement sample, and the value obtained in the second measurement was adopted as the glass transition temperature of the resin.

As a result, the glass transition temperature (Tg) of the resin contained in the resin-containing solution obtained during the production of the resin compositions of Examples 1 to 13 was in the range of 0 ° C. to 60 ° C. rice field. From this, it was confirmed that the glass transition temperature (Tg) of the resin contained in the resin compositions of Examples 1 to 13 was in the range of 0 ° C to 60 ° C.

2. Average Particle Size of Resin Particles The average particle size of the resin particles was measured using each resin-containing solution obtained when each of the resin compositions of Examples 1 to 13 was produced. Specifically, it was measured by the following method.
The resin-containing solution was diluted 30-fold with deionized water, thoroughly stirred and mixed, and then 5 mL was collected in a 10 mm square glass cell using a Pasteur pipette, and this was collected by a dynamic light scattering photometer [ Product name: Zetasizer NANO-ZS90, MALVERN INSTRUMENT]. Next, the set value of the attenuation rate (Attenuator) is set to x8 (8 times), the concentration of the diluent of the resin-containing solution is adjusted so that the Count Rate of the attenuation rate is 150 kCps to 200 kCps, and then the measurement temperature is 25. The average particle size of the resin particles in the resin-containing solution was determined by computer-processing the results measured under the conditions of ° C. ± 1 ° C. and a light scattering angle of 90 °. As the value of the average particle size, the value of the Z average was used.

As a result, the average particle size of the resin particles contained in the resin-containing solutions obtained during the production of the resin compositions of Examples 1 to 13 was in the range of 20 nm to 400 nm. From this, it is considered that the average particle size of the resin particles contained in the resin compositions of Examples 1 to 13 is in the range of 20 nm to 400 nm.

[evaluation]
The following evaluations were carried out for each of the resin compositions of Examples 1 to 13 and Comparative Examples 1 to 12. The results are shown in Tables 1 and 2.

1. 1. Adhesion to olefin base material The resin composition is placed on a polypropylene film [trade name: Trefan (registered trademark) # 40-2578, thickness: 40 μm, Toray Industries, Inc.], which is the base material, using a bar coater. And applied to form a coating film. The bar coater was selected so that the thickness of the film after drying was 500 nm.
Next, the formed coating film was heated at 100 ° C. for 1 minute and dried to obtain a test piece X having a layer structure of "a film formed of a polypropylene film / resin composition". Using the obtained test piece X, a cross-cut test based on JIS K5600-5-6 (cross-cut method) was performed on a film formed of the resin composition. In this cross-cut test, the cut interval was set to 1 mm, and 100 1 mm square grids were formed. After the test, the number of lattices that did not peel off was measured, and the ratio was calculated.
When the ratio of the number of lattices that did not peel off was 95% or more, it was determined that the resin composition could form a film having excellent adhesion to the olefin base material. The ratio of the number of lattices that did not peel off is particularly preferably 100%.

2. Easy Adhesion to Functional Layer (1) UV Ink Layer Specimen X was obtained by the same method as in "1. Adhesion to olefin substrate" above.
Next, on the surface of the obtained test piece X opposite to the polypropylene film, that is, on the film formed by the resin composition, UV ink resin [trade name: Dicure (registered trademark) MAR50, DIC Corporation ] Was applied using a bar coater to form a coating film. The bar coater was selected so that the thickness of the film after drying was 7 μm.
Then, the formed coating film was heated at 100 ° C. for 1 minute. The heated film is irradiated with ultraviolet rays having a lamp output of 160 W / cm using an ultraviolet irradiation device so that the integrated light amount is 250 mJ / cm ^2, and the film is cured to obtain a "polypropylene film / resin composition". A test piece Y having a layer structure of "a film / UV ink layer formed of an object" was obtained.
Using the obtained test piece Y, a cross-cut test based on JIS K5600-5-6 (cross-cut method) was performed on the UV ink layer. In this cross-cut test, the cut interval was set to 1 mm, and 100 1 mm square grids were formed. After the test, the number of lattices that did not peel off was measured, and the ratio was calculated.
When the ratio of the number of lattices that did not peel off was 80% or more, it was determined that the resin composition could form a film having excellent adhesiveness to the UV ink layer. The ratio of the number of lattices that did not peel off is particularly preferably 100%.

Since the films formed by the resin compositions of Comparative Example 4, Comparative Example 5, and Comparative Example 10 had very poor adhesion to the polypropylene film, an evaluation test of easy adhesion to the UV ink layer could be performed. could not.

(2) Hard coat layer Specimen X was obtained by the same method as in "1. Adhesion to olefin substrate" above.
Next, a hard coat resin [trade name: HX-1000UV, Kyoeisha Chemical Co., Ltd.] was applied on the surface of the obtained test piece X opposite to the polypropylene film, that is, on the film formed of the resin composition. , A coating was formed using a bar coater. The bar coater was selected so that the thickness of the film after drying was 7 μm.
Then, the formed coating film was heated at 100 ° C. for 1 minute. The heated film is irradiated with ultraviolet rays having a lamp output of 160 W / cm using an ultraviolet irradiation device so that the integrated light amount is 250 mJ / cm ^2, and the film is cured to obtain a “polypropylene film / resin composition”. A test piece Z having a layer structure of "a film / hard coat layer formed of an object" was obtained.
Using the obtained test piece Z, a cross-cut test based on JIS K5600-5-6 (cross-cut method) was performed on the hard coat layer. In this cross-cut test, the cut interval was set to 1 mm, and 100 1 mm square grids were formed. After the test, the number of lattices that did not peel off was measured, and the ratio was calculated.
When the ratio of the number of lattices that did not peel off was 95% or more, it was judged that the resin composition could form a film having excellent adhesiveness to the hard coat layer. The ratio of the number of lattices that did not peel off is particularly preferably 100%.

Since the films formed by the resin compositions of Comparative Example 4, Comparative Example 5, and Comparative Example 10 had very poor adhesion to the polypropylene film, an evaluation test of easy adhesion to the hard coat layer could be performed. could not.

In Tables 1 and 2, "-" in the composition column means that the corresponding component is not blended. In Tables 1 and 2, "-" in the columns other than the composition column means that the corresponding item has not been evaluated. The amount of the surfactant shown in Tables 1 and 2 is converted to the active ingredient. The value.
The blending amounts of the cross-linking agents shown in Tables 1 and 2 are solid content conversion values.

Details of each component shown in Tables 1 and 2 are as shown below.
[Monomer]
<(Meta) acrylic monomer with branched chain>
"I-BMA": i-butyl methacrylate "t-BA": t-butyl acrylate <(meth) acrylic monomer having an alicyclic structure>
"CHMA": Cyclohexylmethacrylate <monomer having a carboxy group>
"AA": Acrylic acid "MAA": Methacrylic acid <Monomer having a hydroxyl group>
"N-MAM": N-methylolacrylamide <other monomers>
"MMA": Methyl methacrylate (methacrylic acid alkyl ester monomer)
"EA": ethyl acrylate (acrylic acid alkyl ester monomer)
"N-BMA": n-butyl methacrylate (methacrylic acid alkyl ester monomer)

[Reactive surfactant]
<Anion type>
"Aqualon KH-10" [trade name, active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether sulfate ammonium [average number of moles of oxyethylene group added: 10], active ingredient concentration: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd.]
"Aqualon AR-10" [trade name, active ingredient: polyoxyethylene styrenated propenylphenyl ether sulfate ammonium [average number of moles of oxyethylene group added: 10], active ingredient concentration: 99% by mass, Daiichi Kogyo Seiyaku Co., Ltd. ( stock)]
The above "Aqualon" is a registered trademark.

<Specific nonion type>
"Adecaria Soap ER-30" [trade name, active ingredient: polyoxyethylene-1- (allyloxymethyl) alkyl ether [average number of moles of oxyethylene group added: 30], active ingredient concentration: 65% by mass, formula Nonionic reactive surfactant represented by (1), ADEKA Corporation]
"Aqualon AN-10" [Product name, average number of moles of oxyethylene group added: 10, Dai-ichi Kogyo Seiyaku Co., Ltd.]
"Aqualon AN-30" [Product name, average number of moles of oxyethylene group added: 30, Dai-ichi Kogyo Seiyaku Co., Ltd.]
The above "Adecaria Soap" and "Aqualon" are both registered trademarks.

[Non-reactive surfactant]
<Anion type>
"Neoperex G-65" [Product name, active ingredient: sodium dodecylbenzenesulfonate, active ingredient concentration: 65% by mass, Kao Corporation]
<Nonion type>
"Neugen EA-177" [Product name, active ingredient: polyoxyethylene styrenated phenyl ether [average number of moles of oxyethylene group added: 20], active ingredient concentration: 100% by mass, Daiichi Kogyo Seiyaku Co., Ltd.]
"Neugen EA-197D" [Product name, active ingredient: polyoxyethylene phenyl ether, active ingredient concentration: 60% by mass, Dai-ichi Kogyo Seiyaku Co., Ltd.]
The above "Neoperex" and "Neugen" are both registered trademarks.

[Crosslinking agent]
<Isocyanate cross-linking agent>
"Takenate WD-725" [Product name, water-dispersed isocyanate-based cross-linking agent, hexamethylene diisocyanate, solid content concentration: 100% by mass, isocyanate group content: 15.96% by mass, Mitsui Chemicals, Inc.]
"Duranate WL70-100" [Product name, water-dispersed isocyanate-based cross-linking agent, hexamethylene diisocyanate, solid content concentration: 100% by mass, isocyanate group content: 15.5% by mass, Asahi Kasei Co., Ltd.]
<Oxazoline-based cross-linking agent>
"Epocross WS-500" [Product name, solid content concentration: 39% by mass, Nippon Shokubai Co., Ltd.]
<Epoxy cross-linking agent>
"Denacol EX-810" [Product name, solid content concentration: 100% by mass, Nagase ChemteX Corporation]
The above-mentioned "Takenate", "Duranate", "Epocross", and "Denacol" are all registered trademarks.

As shown in Table 1, the films formed by the resin compositions of Examples 1 to 13 were excellent in adhesion to the polyolefin substrate. Further, the films formed by the resin compositions of Examples 1 to 13 showed excellent easy adhesiveness to both the functional layers of the UV ink layer and the hard coat layer.

On the other hand, as shown in Table 2, the films formed by the resin compositions of Comparative Examples 1 to 12 were inferior in at least one of the adhesion to the polyolefin base material and the easy adhesion to the functional layer.

The disclosure of Japanese Patent Application No. 2020-025662 filed on February 18, 2020 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are the same as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. To the extent, it is incorporated by reference herein.

Claims

A structural unit (A) derived from a (meth) acrylic monomer having a group containing at least one of a branched structure and an alicyclic structure, and a structural unit derived from a monomer having at least one of a carboxy group and a hydroxyl group. (B) and a structural unit (C) derived from a nonionic reactive surfactant having a hydroxyl group, an oxyalkylene group, and an ethylenically unsaturated double bond, and the content of the structural unit (A). However, all structural units [however, structural units derived from reactive surfactants are excluded. ] With respect to 65% by mass or more of the resin particles,
Isocyanate cross-linking agent and
Contains water,
A resin composition for coating a polyolefin base material, wherein the ratio of the number of moles of isocyanate groups in the isocyanate-based cross-linking agent to the total number of moles of carboxy groups and hydroxyl groups in the resin is 0.30 or more.
The polyolefin substrate according to claim 1, wherein the isocyanate-based cross-linking agent is at least one selected from the group consisting of an aqueous dispersion-type isocyanate-based cross-linking agent and a blocked isocyanate-based cross-linking agent having a dissociation temperature of 100 ° C. or lower. Resin composition for coating.
The resin composition for coating a polyolefin base material according to claim 1 or 2, wherein the average number of moles of the oxyalkylene group added in the nonionic reactive surfactant is in the range of 5 or more and 40 or less.
The polyolefin base material coating according to any one of claims 1 to 3, wherein the (meth) acrylic monomer having a group containing the branched structure is at least one of i-butyl methacrylate and t-butyl acrylate. Resin composition for use.
The resin composition for coating a polyolefin base material according to any one of claims 1 to 4, wherein the (meth) acrylic monomer having a group containing the alicyclic structure is cyclohexyl methacrylate.
The resin composition for coating a polyolefin base material according to any one of claims 1 to 5, wherein the structural unit (B) contains a structural unit derived from N-methylolacrylamide.
Claims 1 to claim that the nonionic reactive surfactant having a hydroxyl group, an oxyalkylene group, and an ethylenically unsaturated double bond is a nonionic reactive surfactant represented by the following formula (1). 6. The resin composition for coating a polyolefin base material according to any one of 6.

In the formula (1), R 1b represents an aliphatic alkyl group having 6 to 24 carbon atoms, and X 1b represents a hydrogen atom. n3 represents the average number of moles of oxyethylene groups added and represents an integer of 5 to 50.
The content of the structural unit (B) in the resin is the total structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], The resin composition for coating a polyolefin base material according to any one of claims 1 to 7, which is in the range of 1% by mass or more and 10% by mass or less.
The content of the structural unit (C) in the resin is the structural unit of the resin [however, the structural unit derived from the reactive surfactant is excluded. ], The resin composition for coating a polyolefin base material according to any one of claims 1 to 8, which is in the range of 4.9 parts by mass or more and 27.5 parts by mass or less with respect to a total of 100 parts by mass.