JP2002088126A - Water based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water based resin composition capable of giving a film having at least one improved property selected from weather resistance, water resistance, adhesion and the like. SOLUTION: This water based resin composition is obtained by using a production method comprising a step for obtaining (B) a polymer by polymerizing an acrylic monomer in the presence of (A) a copolymer obtained by copolymerizing a mixture comprising (A1) 5-99.4 wt.% monomer containing a cycloalkyl group and having an ethylenic double bond, (A2) 0.1-20 wt.% monomer containing an alkoxysilyl group and having the ethylenic double bond, and (A3) 0.5-30 wt.% monomer containing an anionic group and having the ethylenic double bond, in an organic solvent, and substituting the organic solvent with an aqueous medium. The ratio of the acrylic monomer to the mixture consisting of the components (A1) to (A3) by weight expressed in terms of the used amounts is regulated so as to be (100/5)-(100/100).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aqueous resin composition used for forming a film in a wide range of fields such as a paint base, an adhesive, a material for textile processing, and civil engineering, and a method for producing the same. In particular, the present invention relates to an aqueous resin composition capable of forming a film having excellent durability against deterioration by light such as ultraviolet light and visible light, and (weather resistance).

[0002]

2. Description of the Related Art Aqueous resin compositions are generally superior in terms of safety and hygiene as compared with solvent-based resin compositions (using an organic solvent), so that paints, adhesives, fiber processing, Widely used in civil engineering and other fields. However, the aqueous resin composition is usually related to the fact that it contains a water-soluble component such as an emulsifier, the water resistance of the formed film, the weather resistance, etc., compared with the solvent-based resin composition, There is a problem of inferiority.

Therefore, various studies have been made to improve the water resistance, weather resistance and the like of the formed film (see Japanese Patent Application Laid-Open No. 8-27349 and Japanese Patent No. 2546216). However, the water resistance, weather resistance, and the like of the film formed from these aqueous resin compositions are not always sufficient, and further improvements are required.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and has been made in consideration of the following problems.
At least one selected from water resistance, adhesion, and the like is to provide an improved aqueous resin composition as compared with a conventional aqueous resin composition.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a monomer mixture containing a cycloalkyl group-containing monomer having an ethylenic double bond is co-existed in an organic solvent. Polymerization, replacing the solvent with an aqueous medium, polymerizing an acrylic monomer in an aqueous medium in the presence of a specific copolymer obtained by replacing the solvent with an aqueous medium and then neutralizing as necessary. It was found that the resulting aqueous resin composition was excellent in the above-mentioned performance.

[0006] The present invention provides a new aqueous resin composition,
It comprises (A1) a monomer containing a cycloalkyl group and having an ethylenic double bond, (A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond, and (A1)
3) comprising a monomer containing an anionic group and having an ethylenic double bond, (A1): 5 to 99.4% by weight, (A2): 0.1 to 20% by weight, and (A3): 0.5 to 30% by weight of a mixture is copolymerized in an organic solvent, and the organic solvent is replaced with an aqueous medium to obtain a neutralized specific copolymer (A) if necessary. (A) An aqueous resin composition obtained by a production method including a step of polymerizing an acrylic monomer in an aqueous medium in the presence of a copolymer to obtain a polymer (B), Monomer / (mixture comprising (A1) to (A3)) (weight ratio) is 100 /
It is an aqueous resin composition of 5-100 / 100. This aqueous resin composition is particularly suitable for forming a film in the fields of paint bases, adhesives, materials for textile processing, and civil engineering.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous resin composition of the present invention is obtained by obtaining a specific (A) copolymer, and then obtaining the specific (A) copolymer.
It can be produced by obtaining the polymer (B) in the presence of the copolymer.

(A) In the step of obtaining a copolymer, (A)
1) a monomer containing a cycloalkyl group and having an ethylenic double bond; (A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond; and (A3) a monomer containing an anionic group and containing an ethylenic double bond. A mixture comprising a monomer having a heavy bond, wherein (A1) is 5 to 99.4% by weight, (A2) is 0.1 to 20% by weight, and (A3) is 0.5 to 30% by weight. Is polymerized (radical polymerization) in an organic solvent.

In the present specification, "(A1) a monomer containing a cycloalkyl group and having an ethylenic double bond"
The term (hereinafter also referred to as “(A1) monomer”) refers to a compound that provides a (C) copolymer with a cycloalkyl group by a (radical) polymerization reaction.

The term "cycloalkyl group" refers to a so-called cycloalkyl group which may have a substituent, and is not particularly limited as long as it is a cycloalkyl group capable of obtaining the aqueous resin composition aimed at by the present invention. It is not something to be done. As such a “cycloalkyl group”, a monocyclic cycloalkyl group is preferable, and examples thereof include a cyclopentyl group, a cyclohexyl group, and a cyclododecyl group. A cycloalkyl group can have an alkyl group as a substituent, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group,
Examples thereof include an isobutyl group, a tertiary butyl group, a pentyl group, a hexyl group, and a heptyl group.

As used herein, "ethylenic double bond"
Means a double bond between carbon atoms capable of undergoing a polymerization reaction (radical polymerization). As such a functional group having an ethylenic double bond, for example, a vinyl group (CH ₂ −CH—),
(Meth) allyl groups (CH ₂ ＣＨCH—CH ₂ — and CH ₂ ＝
C (CH ₃ ) —CH ₂ —), (meth) acryloyloxy group (CH ₂ ＣＨCH—COO— and CH ₂ ＣC (CH ₃ ) —
COO-) and -COO-CH = CH-COO-.

In the present specification, acrylic acid and methacrylic acid are collectively referred to as "(meth) acrylic acid", and acrylate and methacrylate are collectively referred to as "(meth) acrylate" or Also referred to as “(meth) acrylate”. The same applies to an allyl group and an acryloyloxy group.

Therefore, by having both a cycloalkyl group and an ethylenic double bond, for example, if necessary, the cycloalkyl group can form an ethylenic double bond via another functional group such as an ester bond or an alkylene group. By bonding to the above, a monomer containing a cycloalkyl group and having an ethylenic double bond is obtained.

As such “(A1) a monomer containing a cycloalkyl group and having an ethylenic double bond”, for example, (I): CH ₂ ＣＲCR ¹ —COO—R ² [where the formula (I) In I), R ¹ represents H, a methyl group or an ethyl group, and R ² represents a cycloalkyl group which may have a substituent. The compound shown by these is preferable.

As the "cycloalkyl group optionally having substituent (s)", a monocyclic cycloalkyl group is preferable. For example, a cyclopentyl group, a cyclohexyl group, and a cyclododecyl group are preferable. For example,
Methyl group, ethyl group, propyl group, isopropyl group, n
Examples thereof include alkyl groups having 1 to 7 carbon atoms, such as -butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, and heptyl group.

More specifically, as the (A1) monomer,
For example, cyclohexyl (meth) acrylate, methylcyclohexyl (meth) acrylate, and t-butylcyclohexyl (meth) acrylate can be preferably exemplified. (A1) A commercially available product can be used as the monomer,
(A1) The monomers can be used alone or in combination.

The mixture for obtaining the copolymer (A) is as follows:
(A1) Preferably, it comprises 5 to 99.4% by weight, more preferably 20 to 97.5% by weight, more preferably 40 to 90% by weight of a monomer containing a cycloalkyl group and having an ethylenic double bond. It is particularly preferred to contain 97.5% by weight.

Further, in the present specification, "(A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond" (hereinafter also referred to as "(A2) monomer") mainly means (A) A) a compound that forms a crosslinked structure inside the copolymer or between the (A) copolymers and can contribute to the improvement of weather resistance, water resistance, etc. of the film obtained from the aqueous resin composition of the present invention. .

Here, the term "alkoxysilyl group" refers to a silicon-containing functional group which gives a hydroxyl group (Si-OH) bonded to silicon by hydrolysis, for example, a trimethoxysilyl group, a triethoxysilyl group, Dimethoxymethylsilyl group, dimethoxymethylsilyl group,
It refers to an alkoxysilyl group such as a diethoxysilyl group, a monoethoxysilyl group, and a monomethoxysilyl group, and particularly preferably a trimethoxysilyl group and a triethoxysilyl group. The “ethylenic double bond” is as described above.

(A2) As a monomer containing an alkoxysilyl group and having an ethylenic double bond, for example, (III): R ⁵ Si (OR ⁶ ) (OR ⁷ ) (OR ⁸ ) In III), R ⁵ represents a functional group having an ethylenic double bond, and R ⁶ , R ⁷ and R ⁸ represent an alkyl group having 1 to 5 carbon atoms which may be the same or different from each other. ] Can be exemplified.

Examples of the functional group having an ethylenic double bond of R ⁵ include a vinyl group, a (meth) allyl group, a (meth) acryloyloxy group, a 2- (meth) acryloyloxyethyl group and a 2- (meth) Acryloyloxypropyl group, 3- (meth) acryloyloxypropyl group,
Examples thereof include a 2- (meth) acryloyloxybutyl group, a 3- (meth) acryloyloxybutyl group, and a 4- (meth) acryloyloxybutyl group.

Examples of the alkyl group having 1 to 5 carbon atoms of R ⁶ , R ⁷ and R ⁸ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group,
Examples thereof include a linear or branched alkyl group such as a sec-butyl group, a t-butyl group, and an n-pentyl group.

(A2) As a monomer containing an alkoxysilyl group and having an ethylenic double bond, specifically,
(A2-1) Vinyl trialkoxysilane such as vinyltrimethoxysilane, vinyltriethoxysilane and vinyltri-n-butoxysilane; (A2-2) (II): CH ₂ ＝ CR ³ —COO—Z—Si (OR ⁴ ) ₃ [In the formula (II), R ³ is H or CH ₃ ,
R ⁴ is an alkyl group having 1 to 3 carbon atoms, and Z is 1 to 3 carbon atoms.
6 represents an alkylene group. Ω- (meth) acryloyloxyalkyl trialkoxysilane represented by the formula:
2-3) Allyltrialkoxysilanes such as allyltriethoxysilane and allyltrimethoxysilane; and the like.

(A2) As a monomer containing an alkoxysilyl group and having an ethylenic double bond, (A2-2) (II): CH ₂ ＣＲCR ³ —COO—Z—Si (OR ⁴ ) ₃ [ However, in the formula (II), R ³ is H or CH ₃ ,
R ⁴ is an alkyl group having 1 to 3 carbon atoms, and Z is 1 to 3 carbon atoms.
6 represents an alkylene group. Is more preferable.

Specific examples of the compound represented by the formula (II) include, for example, 3- (meth) acryloyloxypropyltrimethoxysilane and 3- (meth) acryloyloxypropyltriethoxysilane. In particular,
3- (meth) acryloyloxypropyltrimethoxysilane and 3- (meth) acryloyloxypropyltriethoxysilane are preferred.

These monomers (A2) containing an alkoxysilyl group and having an ethylenic double bond can be appropriately selected according to the properties of the copolymer (A), and may be used alone or in combination. can do.

The mixture for obtaining the copolymer (A) is as follows:
(A2) The monomer containing an alkoxysilyl group and having an ethylenic double bond is preferably contained in an amount of 0.1 to 20% by weight, more preferably 0.5 to 15% by weight. It is particularly preferred to contain 5 to 10% by weight.

As used herein, “(A3) a monomer containing an anionic group and having an ethylenic double bond” (hereinafter also referred to as “(A3) monomer”) refers to an anionic group and an ethylenic double bond. A compound having a bond, which provides an anionic group to the copolymer (A) by a polymerization reaction (radical polymerization) to impart hydrophilicity and anionicity.

"Anionic group" is a functional group having a negative charge.
Groups (eg, -COO^-And -SO_Three ^-Etc.)
Functional groups electrically neutralized by cations (eg,
For example, -COO^-Na⁺And -SO_Three ^-K⁺Etc.) and
Releases hydrogen ions in water to form negatively charged functional groups
Functional groups that can be formed (for example, -COOH and -SO_ThreeH
Etc.). These “functional groups having a negative charge” and
"Releases hydrogen ions in water to create negatively charged functional groups.
"Functional groups that can be formed" refer to the state around each functional group, for example,
Can be easily converted to each other by changing pH, etc.
It goes without saying that it is capable. In the present invention, “ani
Regarding the “on group”, according to the properties of the (A) copolymer,
These functional groups may be used alone or in combination.
it can.

The “functional group having a negative charge (including a functional group in which the negative charge is electrically neutralized by a counter cation)” includes, for example, carboxylate groups (—COO ⁻ and —COOM ¹ ), Sulfonate groups (—SO ₃ ^— and —S
O ₃ M ² ), and phosphate bases (—PO ₄ H ⁻ , —PO ₄ ²⁻ and —PO ₄ M ³ M ⁴ ), etc. [however, M ¹ , M ² ,
M ³ and M ⁴ are an alkali metal, an alkaline earth metal or ammonium (note that one of M ³ and M ⁴ may be hydrogen)]. Further, as the “functional group capable of forming a functional group having a negative charge by releasing hydrogen ions in water”, for example, a carboxyl group (—COOH), a sulfonic acid group (—SO ₃ H), and a phosphate group (− PO ₄ H ₂ ). "Ethylenic double bond" is as described above.

Examples of such “(A3) a monomer containing an anionic group and having an ethylenic double bond” include, for example,
The following compounds can be exemplified: (A3-1) acrylic acid, methacrylic acid, itaconic acid,
A compound having a carboxyl group and an ethylenic double bond, such as crotonic acid, fumaric acid, maleic acid, and a half ester of maleic acid; and a compound having a carboxylate group and an ethylenic double bond; (A3-2) acrylic sulfonic acid A compound having a sulfonic acid group and an ethylenic double bond, such as methacrylsulfonic acid, 2-acryloylamino-2-methylpropanesulfonic acid, 2-methacryloylamino-2-methylpropanesulfonic acid, and styrenesulfonic acid; and sulfonic acid. A compound having a phosphate group and an ethylenic double bond, such as (A3-3) (meth) acrylic acid oxyethylamide phosphate; a phosphate base and an ethylenic double bond; A compound having a bond.

(A3) As a monomer containing an anionic group and having an ethylenic double bond, (A3-1) a compound having a carboxyl group and an ethylenic double bond, and a carboxylate group and an ethylenic double bond Are preferable, and acrylic acid and methacrylic acid are particularly preferable. Incidentally, the counter cation of the carboxylate group, the sulfonate group, and the phosphate group are preferably ammonium ions and alkali metal ions, particularly, ammonium ion,
Potassium ions and sodium ions are preferred. These (A3) monomers containing an anionic group and having an ethylenic double bond can be used alone or in combination according to the properties of the desired (A) copolymer.

The mixture for obtaining the copolymer (A) is as follows:
(A3) The composition preferably contains 0.5 to 30% by weight, more preferably 2 to 20% by weight, and more preferably 2 to 15% by weight of a monomer containing an anionic group and having an ethylenic double bond. It is particularly preferred to include.

The mixture for obtaining the copolymer (A) may further contain (A4) another monomer having an ethylenic double bond. In the present specification, “(A4) another monomer having an ethylenic double bond” (hereinafter, also referred to as “(A4) monomer”) refers to the above (A1) to (A1)
A monomer having an ethylenic double bond other than (A3) and capable of copolymerizing (radical polymerizing) with the above-mentioned (A1) to (A3). )
It can be used appropriately according to the properties of the copolymer.
The “ethylenic double bond” is as described above.

Examples of such “(A4) other monomers having an ethylenic double bond” include the following compounds: (A4-1) methyl (meth) acrylate, ethyl (meth) acrylate (Meth) acryl such as propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate (A4-2) (meth) acrylic esters having an epoxy group such as glycidyl (meth) acrylate; (A4-3) styrene and derivatives of styrene such as styrene and vinyltoluene; -4) alkenes such as ethylene, butadiene and iso (A4-5) Vinyl ester compounds such as vinyl acetate and vinyl propionate; (A4-6) Chlorinated vinyl compounds such as vinyl chloride and vinylene chloride; (A4-7) acrylonitrile (A4-8) Monomers containing a light-stable group such as a hindered amine-based compound and a hindered alcohol-based compound and having an ethylenic double bond. (A4-9) a benzotriazole-based or benzophenone-based monomer containing an ultraviolet absorbing group and having an ethylenic double bond. These (A4) and other monomers having an ethylenic double bond can be used alone or in combination.

(A4) Other monomers having an ethylenic double bond include (A4-1) alkyl (meth) acrylates and (A4-8) an ethylenic double bond containing a photostable group. A monomer having a bond and (A4-9) a monomer containing an ultraviolet absorbing group and having an ethylenic double bond are preferred. These (A4) and other monomers having an ethylenic double bond can be used singly or in combination according to the properties of the desired (A) copolymer.

The (A) copolymer is obtained by copolymerizing a monomer mixture containing (A1) to (A3) and optionally containing (A4) in an organic solvent. It can be obtained by replacing with a medium. (A) Depending on the properties such as water solubility of the copolymer, the copolymer may be neutralized with an alkaline substance as necessary.

The monomer mixture comprising (A1) to (A3) comprises: (A1): 5 to 99.4% by weight, (A2): 0.1 to 20% by weight, and (A3): 0. (A1): 20 to 97.5% by weight, (A2): 0.5 to 15% by weight, and (A3): 2 to 20% by weight. ): 40 to 97.5% by weight, (A2): 0.5 to 10% by weight and (A3): 2 to 15% by weight.

When the monomer mixture comprising (A1) to (A3) further contains (A4), the content of (A4) is the balance of (A1) to (A3). Further, the acid value of the obtained copolymer (A) is preferably less than 200 mgKOH / g, more preferably 160 mgKOH / g or less, and particularly preferably 120 mgKOH / g or less.

The copolymerization of the monomer mixture containing (A1) to (A3) can be carried out by using a usual solution polymerization method and appropriately using a catalyst or the like in an organic solvent. It can be carried out by polymerizing the mixture (radical polymerization). Here, the “organic solvent” includes (A1) to (A3), and can be used for copolymerization of a monomer mixture containing (A4) if necessary. There is no particular limitation as long as the properties are not substantially adversely affected. Examples of such an organic solvent include lower alcohols such as methanol, ethanol, and propanol, esters such as ethyl acetate, and combinations thereof.

The reaction temperature, reaction time, type of organic solvent, type and concentration of monomer mixture, stirring speed, and type and concentration of catalyst for the copolymerization of the mixture comprising (A1) to (A3) The conditions of the polymerization reaction can be appropriately selected depending on the characteristics of the target (A) copolymer and the like.

The term "catalyst" used herein refers to a compound capable of causing the copolymerization of a mixture containing (A1) to (A3) by adding a small amount thereof, and which is used in an organic solvent. Are preferred. For example, ammonium persulfate, sodium persulfate, potassium persulfate, t
-Butyl hydroperoxide, t-butyl peroxybenzoate, 2,2-azobisisobutyronitrile (A
IBN), 2,2-azobis (2-amidinopropane)
Examples thereof include dihydrochloride and 2,2-azobis (2,4-dimethylvaleronitrile), and particularly, 2,2-azobisisobutyronitrile (AIBN)
And 2,2-azobis (2-amidinopropane) dihydrochloride are preferred.

Further, a chain transfer agent or the like can be appropriately used. As a “chain transfer agent” for controlling the molecular weight,
Compounds known to those skilled in the art can be used, and examples thereof include mercaptans such as n-dodecyl mercaptan and lauryl methyl mercaptan.

After the copolymerization, the organic solvent is replaced by an aqueous medium. A conventional method can be used for the replacement with the aqueous medium, and examples thereof include a method of distilling off the organic solvent and then adding the aqueous medium, and a method of adding the aqueous medium and distilling off the organic solvent by distillation. In the present specification, the "aqueous medium" mainly refers to so-called water such as distilled water, ion-exchanged water, and pure water, but can appropriately include a water-soluble organic solvent, for example, acetone and a lower alcohol. . By replacing the organic solvent with an aqueous medium,
(A) A copolymer can be obtained.

(A) Depending on the properties of the copolymer, it may be neutralized. Here, “neutralization” can be performed by adding an alkaline substance usually used for neutralization. As a result, in particular, the carboxyl group in the system is neutralized, and water solubility can be imparted to the target copolymer. But,
(A) The copolymer need not be completely water-soluble. It is sufficient that the specific (A) copolymer has the necessary water solubility within a range that does not deteriorate the properties of the target aqueous resin composition, that is, within the range of the predetermined target properties.

As used herein, the term "alkaline substance" refers to a substance that exhibits a pH of greater than 7 when dissolved in water, and is not particularly limited as long as it is generally called an alkaline substance. The form of the alkaline substance is not limited to gas, liquid and solid, but the form of an aqueous solution dissolved in water can be handled, and the neutralization reaction can be easily controlled, and it is preferable. Examples of such an “alkaline substance” include ammonia, alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, and the like.
Aqueous sodium and potassium solutions are preferred.

The alkaline substance is preferably added so that the pH of the aqueous medium containing the copolymer (A) is 8.0 or more, and more preferably 8.0 to 10.0. Is more preferable, and it is particularly preferable to add so as to have a pH of 8.5 to 9.5.

The copolymer (A) according to the present invention has a function as a protective colloid in the polymerization of an acrylic monomer described later. Therefore, the copolymer (A) has a function required as a protective colloid, for example, a function capable of performing emulsion polymerization without using an emulsifier and stabilizing an emulsion. Furthermore, the copolymer (A) also provides the water-based resin composition of the present invention with the ability to absorb and adhere to a substrate.

The (A) copolymer is usually handled in the form of being present in an aqueous medium, and is not usually handled by the (A) copolymer alone after isolation from the aqueous medium. In this case, the amount of the copolymer (A) present in the aqueous medium is represented by using the concentration in the aqueous medium. Here, the concentration of (A) copolymer is 105
After drying in an oven at a temperature of 3 ° C. for 3 hours, the weight of the remaining portion is shown as a percentage by weight based on the weight before drying.

In this specification, “parts by weight” and “% by weight” are based on the weight of the copolymer (A) not containing a medium. Therefore, the parts by weight of the (A) copolymer are based on the weight calculated based on the concentration of the (A) copolymer.

The aqueous resin composition of the present invention comprises the above (A)
It is obtained by polymerizing an acrylic monomer in an aqueous medium in which a copolymer exists. (A) Since the copolymer functions as a protective colloid in an aqueous medium, it is not necessary to add an emulsifier, but an additional emulsifier may be added as appropriate.

5 to 100 parts by weight of (A1) based on the amount used
The acrylic monomer for obtaining the polymer (B) is polymerized in an amount of 100 parts by weight with respect to the mixture containing (A3) to (A3).
(A1) to (A) per 100 parts by weight of the acrylic monomer
The mixture comprising 3) is from 5 to 100 parts by weight;
It is more preferably 5 to 80 parts by weight, particularly preferably 5 to 60 parts by weight.

In the present specification, “acrylic monomer” is used for producing an aqueous resin composition which is usually used for paints, adhesives, textile processing, civil engineering, and the like.
In addition to monomers selected from so-called acrylic acid derivatives and methacrylic acid derivatives, monomers having an ethylenic double bond capable of polymerizing (radical polymerizing) with monomers selected from acrylic acid derivatives and methacrylic acid derivatives Or a mixture containing a plurality of these monomers.

Further, a polymer obtained by directly polymerizing the “acrylic monomer” in the absence of the above-mentioned specific polymer (hereinafter also referred to as “polymer of acrylic monomer”,
(Substantially corresponding to the polymer (B) in the present specification) alone at room temperature (20 to 30 ° C.) preferably has practical toughness, and more preferably has gloss.

Examples of such an acrylic monomer include the following monomers: (B1) Methyl (meth) acrylate, ethyl (meth)
Acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, (B2) alkyl (meth) acrylate compounds having an alkyl group having 1 to 18 carbon atoms which may have a substituent, such as isooctyl (meth) acrylate, isononyl (meth) acrylate, and dodecyl (meth) acrylate; (B3) dimethylaminoethyl (meth) acrylate having a hydroxyl group such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate;
Nitrogen-containing (meth) acrylic acid derivatives such as N-methylolacrylamide, N-methylolmethacrylamide, t-octylacrylamide, and diethylaminoethyl (meth) acrylate; (B4) ethylene glycol di (meth) acrylate;
Ethylenic double bonds such as diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, and tetramethylolmethanetetra (meth) acrylate (B5) Other (meth) acrylic acid derivatives such as glycidyl (meth) acrylate; and (B6) Unsaturation such as ethylene, propylene, isobutylene, butadiene, and isoprene. (B7) Styrene such as styrene and α-methylstyrene and derivatives thereof; (B8) Vinyl compounds such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl butyral; (B9) PVC, Vinylidene chloride, chloroprene,
(B10) Monomers having a nitrogen atom and an ethylenic double bond, such as acrylamide, acrylonitrile, N-vinylpyrrolidone and vinylpyridine, and the like. (B11) monomers having at least two ethylenic double bonds, such as divinylbenzene, divinylsilane, diallyl phthalate, cyclopentadiene, methylenebisacrylamide, diallyl malate, and tetraallyloxyethane; (B12) hindered amines And a monomer having a light-stable group such as a hindered alcohol group and having an ethylenic double bond; and (B14) The above (A1) and (A2) , And (A3)
etc. These acrylic monomers can be used alone or in combination.

The acrylic monomer has (B1) an alkyl group having 1 to 18 carbon atoms which may have a substituent (meth)
Alkyl acrylate compounds, (A1) a monomer containing a cycloalkyl group and having an ethylenic double bond, (B12) a monomer containing a photostable group and having an ethylenic double bond, (B13) And / or (A2) at least one selected from a monomer containing an alkoxysilyl group and having an ethylenic double bond. Is preferred.

Polymerization of acrylic monomer (radical polymerization)
Can be carried out in an aqueous medium using an appropriate catalyst and the like, using a usual emulsion polymerization method. Here, the “aqueous medium” is as described above. An emulsifier is not particularly required since the copolymer (A) present in the aqueous medium can act as a protective colloid, but an additional emulsifier can be used as appropriate. Reaction temperature, reaction time, type of aqueous solvent, type and concentration of the monomer mixture, stirring speed, and the conditions of the polymerization reaction such as type and concentration of the catalyst are appropriately determined according to the characteristics of the intended aqueous resin composition and the like. It can be selected.

As additional "emulsifiers", surfactants known to those skilled in the art can be used. Water-soluble polymer compounds can also be used, and cellulose derivatives such as methylcellulose, hydroxyethylcellulose, and carboxymethylcellulose, water-soluble polyurethane resins, water-soluble acrylic resins, polyvinylpyrrolidone-based resins, and polyvinyl alcohol can also be used.

In this specification, “parts by weight” and “% by weight” are based on the weight of the resin containing no medium. Therefore, the parts by weight of the aqueous resin composition is based on the weight calculated based on the concentration of the aqueous resin composition.

Further, in another aspect of the present invention, (B) obtained by polymerization of an acrylic monomer in an aqueous medium.
At least a portion, preferably substantially all, of the polymer is
(A1) a monomer containing a cycloalkyl group and having an ethylenic double bond, (A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond, and (A3) an ethylenic compound containing an anionic group (A1): 5 to 99.4% by weight, (A2): 0.1 to 20% by weight, and (A3): 0.5 to 30% by weight. An aqueous resin composition comprising a resin coated with the copolymer (A) obtained by copolymerization of the mixture, wherein (B) polymer / (A) copolymer (weight ratio) is: An aqueous resin composition having a ratio of 100/5 to 100/100 is provided.

That is, the present invention provides an aqueous resin composition comprising (B) a resin which is at least partially, preferably substantially all, of the polymer (A) is coated with a copolymer. .

(B) Polymer / (A) copolymer (weight ratio)
Is 100/5 to 100/100, but 100/5
~ 100/80, more preferably 100/5 ~
Particularly preferred is 100/60.

Further, in a preferred embodiment of the present invention,
(A1) a monomer containing a cycloalkyl group and having an ethylenic double bond, (A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond, and (A3) an ethylenic compound containing an anionic group (A1): 5 to 99.4% by weight, (A2): 0.1 to 20% by weight, and (A3): 0.5 to 30% by weight. After the mixture is copolymerized in an organic solvent, the organic solvent is replaced with an aqueous medium and, if necessary, neutralized to obtain (A) a copolymer, and (A) in the presence of the copolymer. A process of polymerizing an acrylic monomer in an aqueous medium to obtain a polymer (B), wherein the acrylic monomer /
(Mixture comprising (A1) to (A3)) (weight ratio)
Is 100/5 to 100/100, and at least part, preferably substantially all, of the polymer (B) obtained by polymerizing the acrylic monomer is (A)
Provided is an aqueous resin composition containing a resin coated with a copolymer.

Accordingly, the present invention provides a method for producing a polymer (B) by polymerizing an acrylic monomer in an aqueous medium in the presence of the copolymer (A) in the aqueous medium, There is provided an aqueous resin composition comprising (B) at least a part, preferably substantially all, of the polymer (A) a resin coated with the copolymer.

The aqueous resin composition of the present invention comprises a light stabilizer, which is an added weathering agent at the stage of production or after the production,
An ultraviolet absorber and an antioxidant may be added. Such an added type weathering agent gradually bleeds out and is washed away by rain or the like, and has no effect on long-term weather resistance improvement, but an effect is expected at an early stage.

The aqueous resin composition of the present invention can be used in the fields of paints, adhesives, textile processing, civil engineering, and the like, using conventional methods used for forming a film of the aqueous resin composition. Here, the conventional method includes a method applied to a substrate or the like. Here, “apply” means that an appropriate amount of the aqueous resin composition is present on a substrate or the like, and examples thereof include coating and coating. The application is preferably performed uniformly over the entire surface of the substrate or the like.

As described above, according to the present invention, in the organic solvent, the monomers (A1) to (A3) are copolymerized at a specific ratio to obtain the copolymer (A), and the organic solvent is dissolved in an aqueous solvent. After substitution with a medium, the acrylic monomer is polymerized in an aqueous medium (B)
An aqueous resin composition is obtained by obtaining a polymer. The aqueous resin composition of the present invention can form a coating film improved in at least one selected from water resistance, weather resistance and adhesion as compared with a conventional aqueous resin composition. Further, it is possible to preferably form a film having improved film (film) physical properties, for example, strength and toughness of the film.

As described above, the aqueous resin composition of the present invention can form a film in which at least one selected from water resistance, weather resistance and adhesion is superior to a conventional film. This is considered for the following reason. In the aqueous resin composition of the present invention, since the aqueous resin composition is obtained using the copolymer (A) that functions as a protective colloid, the aqueous resin composition obtained using an emulsifier used in ordinary emulsion polymerization The content of the hydrophilic component contained in the formed film can be reduced as compared to Therefore, it is considered that the hydrophilicity of the film formed from the aqueous resin composition of the present invention can be reduced, and the water resistance and the like of the formed film can be improved.

The polymer (B), which is the main component of the film, is polymerized in the presence of the copolymer (A) which is a protective colloid. Molecular weight can be high. Therefore, it can contribute to the improvement of the water resistance and the like of the formed film, and has high strength,
A tough film can be obtained.

Further, in the aqueous resin composition of the present invention, the copolymer (A) which functions as a protective colloid,
(B) It is considered that the polymer covers at least a part, preferably the whole, of the polymer. Therefore, it is expected that it can contribute to the improvement of the water resistance, weather resistance, adhesion and the like of the film, and (A) the cycloalkyl group and the alkoxysilyl group introduced into the copolymer, (B) It can be applied intensively outside the polymer.

Therefore, in the aqueous resin composition of the present invention, the (A) copolymer is formed because the above-mentioned functional group can be intensively and efficiently provided to the outside of the (B) polymer. It is considered that at least one selected from water resistance, weather resistance, adhesion and the like of the coating is improved.

The aqueous resin composition of the present invention is considered to have excellent properties for the reasons described above, but for these reasons, the aqueous resin composition of the present invention is not limited at all. .

[0073]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples. However, these examples are only one embodiment of the present invention, and the present invention is not limited by these examples. is not. In the examples, parts means parts by weight.

(A) Preparation of copolymers W1 to W4 (A) The following monomers were used in the preparation of copolymers W1 to W4: (A1) a cycloalkyl group containing an ethylenic double bond (A1-1) cyclohexyl methacrylate; (A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond, (a2-1) 3-methacryloyloxypropyltrimethoxysilane; A3) As a monomer containing an anionic group and having an ethylenic double bond, (a3-1) methacrylic acid; and (A4) As a monomer having another ethylenic double bond, (a4-1) n-butyl acrylate, (a4-
2) Methyl methacrylate and (a4-3) n-butyl methacrylate.

In a four-necked flask equipped with a stirring blade, a thermometer, and a reflux condenser, the monomers (a1-1) to
(A4-3) was added at the ratio shown in Table 1, and 2 parts of n
-Dodecyl mercaptan, 300 parts of 2-propanol and 1 part of 2,2'-azobisisobutyronitrile were added. The mixture was heated to 80 ° C. with stirring. 80
The compound was copolymerized by stirring at 5 ° C. for 5 hours. After cooling the reaction mixture to room temperature, the pH of the mixture was adjusted to 9 by adding aqueous ammonia while adding 300 parts of water.
2-propanol was removed by distillation under reduced pressure to obtain a homogeneous and transparent mixture, that is, the copolymers (A) W1 to W4 present in the aqueous medium. (A) The concentrations of the copolymers W1 to W4 were all 25% by weight. The concentration of (A) the copolymers W1 to W4 is the percentage by weight of the portion remaining after drying in an oven at 105 ° C. for 3 hours based on the weight before drying.

[0076]

[Table 1] a) Units of (a1-1) to (a4-3) are parts by weight.

Preparation of Aqueous Resin Compositions of Examples 1-2 and Comparative Examples 1-2 The acrylic monomers (b-1) methyl methacrylate, (b-2) n-butyl acrylate and (a2-1) 3.) 3-methacryloyloxypropyltrimethoxysilane was used. (B-1) is (a4-
2) and (b-2) is (a4-1).

The copolymers (A) W1 to W4 shown in Table 1 were
At a ratio shown in Table 2, a four-necked flask equipped with a stirring blade, a thermometer, and a reflux condenser was added, and 90 parts of distilled water was added. The mixture was heated to 80 ° C. with stirring. (B-
A mixture containing 1), (b-2) and (a2-1) in the proportions shown in Table 2, and 0.3 parts of sodium persulfate and 10 parts
Of each of the mixtures containing a portion of distilled water was simultaneously dropped into the four-necked flask over 3 hours while blowing nitrogen gas.
After dropping, stirring was further continued at 80 ° C. for 2 hours to obtain an emulsion,
That is, the aqueous resin compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were obtained.

The concentrations of the aqueous resin compositions of Examples 1 and 2 and Comparative Examples 1 and 2 The concentrations of the aqueous resin compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were determined after evaporation at 105 ° C. for 3 hours. The mass of the remaining part was measured, and the result was shown as a percentage by weight based on the mass before heating. The results are shown in Table 2.

[0080]

[Table 2] a) The amounts of W1 to W4 and (b-1) to (a2-1) are parts by weight. b) The amount of W1 to W4 is a value calculated based on the concentration of W1 to W4, and is a value that does not substantially contain an aqueous medium. c) The concentration of the aqueous resin composition is a percentage by weight of a portion remaining after drying in an oven at 105 ° C. for 3 hours based on the weight before drying.

Preparation of Aqueous Resin Compositions of Comparative Examples 3 and 4 As acrylic monomers, (b-1) methyl methacrylate, (b-2) n-butyl acrylate, (a1-1)
Cyclohexyl methacrylate (a2-1) 3-methacryloyloxypropyltrimethoxysilane and (a3
-1) Methacrylic acid was used. (B-1) is (a4
-2) and (b-2) is (a4-1).

In a four-necked flask equipped with a stirring blade, a thermometer, and a reflux condenser, 67 parts of distilled water and 1 part of a reactive surfactant (Eleminol JS-2 manufactured by Sanyo Chemical Co., Ltd.) were added.
(Product name)). The mixture was heated and stirred while blowing nitrogen gas, and the liquid temperature was kept at 75 ° C. On the other hand, 40 parts of distilled water, 4 parts of a reactive surfactant (Eleminol JS-2 (trade name) manufactured by Sanyo Chemical Co., Ltd.) and the monomers shown in Table 3 were used in the proportions shown in Table 3. And an aqueous solution containing 0.3 parts of sodium persulfate and 10 parts of distilled water. About 5% by volume of the mixture and about 10% by volume of the aqueous solution are each added to a four-necked flask and stirred to start the emulsion polymerization reaction, and then the remaining portion of the mixture and the remaining portion of the aqueous solution are simultaneously poured for about 3 hours. And added dropwise to the four-necked flask. After stirring for 1 hour while maintaining the liquid temperature at 75 ° C., the obtained reaction mixture was cooled to room temperature. The pH was adjusted to 9 by adding aqueous ammonia to prepare an emulsion, that is, the target Comparative Example 3.
~ 4 aqueous resin compositions were obtained.

Concentrations of Aqueous Resin Compositions of Comparative Examples 3 and 4 The concentrations of the aqueous resin compositions of Comparative Examples 3 and 4 were measured by the method described above. The results are shown in Table 3.

[0084]

[Table 3] a) The amounts of (b-1) to (a3-1) are parts by weight. b) The concentration of the aqueous resin composition is a percentage by weight of a portion remaining after drying in an oven at 105 ° C. for 3 hours based on the weight before drying.

Properties of Film Formed from Aqueous Resin Compositions of Examples 1 and 2 and Comparative Examples 1 to 4 Preparation of Coating Using each of the aqueous resin compositions of Examples 1 and 2 and Comparative Examples 1 to 4. The materials described in Table 4 were mixed at the ratios described in Table 4 to prepare coating materials based on the aqueous resin compositions of Examples 1 and 2 and Comparative Examples 1 to 4.

[0086]

[Table 4] a) Parts by weight of the material, if the material includes a solvent (or medium), is the weight part including the solvent. b) Parts by weight of the aqueous resin composition are parts by weight containing an aqueous medium.

Weather Resistance of Film A coating based on each of the above aqueous resin compositions was applied on a slate plate (with a sealer applied) in a wet state to a thickness of about 1 mm, and dried sufficiently to obtain a film. . J
Using the sunshine carbon arc lamp accelerated weathering conditions specified in 9.8.1 of IS K5400, the coating was placed in a sunshine weather meter for 200 hours.
Hold for 0 hours. The gloss of the film before and after holding the film in the sunshine weather meter was measured using a variable-angle gloss meter to obtain a gloss maintenance ratio (60 ° -60 °). Further, the chromaticity of the film before and after holding the film in the sunshine weather meter is measured using a color difference meter, and the degree of discoloration (ΔE) is measured.
I got The results are shown in Table 5.

Undercoat Adhesion of Film The above paint is applied to a test substrate specified in 6.3 (2) of JIS A6909 in a wet state so as to have a thickness of about 1 mm, and dried at room temperature for 1 hour. It was a test body. The test specimen was subjected to a repeated heating / cooling test specified in 6.11 of JIS A6909. The presence or absence of peeling, cracking and swelling of the film was visually observed.皮膜 indicates that the film did not swell, △ indicates that the swelling occurred, and × indicates that the film peeled. The results are shown in Table 5.

Water Resistance of Coating Each aqueous resin composition plasticized in advance using CS12 (trade name) manufactured by Chisso Co., Ltd.
After coating to a thickness of 0 μm, the coating was dried at room temperature for one week to obtain a film. The film was immersed in water at 20 ° C. for one week. The whitening state of the coating was visually observed. Those that were not whitened were rated as ○, those that were slightly whitened were rated as Δ, and those that were completely whitened were rated X. The results are shown in Table 5.

[0090]

[Table 5]

Comparative Examples 1 and 2 correspond to (A) an aqueous resin composition having no cyclohexyl group, and Comparative Examples 3 and 4 correspond to (A) an aqueous resin composition using no copolymer. Corresponding to The coatings formed from the aqueous resin compositions of Examples 1 and 2 are generally excellent as compared with the coatings formed from the aqueous resin compositions of Comparative Examples 1 to 4, but are particularly excellent in weather resistance. Is understood.

[0092]

The present invention has the features described above, and has the following effects. The aqueous resin composition of the present invention is obtained by copolymerizing a monomer mixture containing a monomer having a cycloalkyl group and having an ethylenic double bond in an organic solvent, and replacing the solvent with an aqueous medium. In the presence of a specific copolymer obtained by neutralization according to the, it is obtained by polymerizing an acrylic monomer, it is selected from the weather resistance, water resistance, and adhesion of the formed film. At least one is improved. Preferably, the weather resistance of the coating is improved.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 133/00 C09J 133/00 151/00 151/00 F-term (Reference) 4J011 KA15 KA21 KA27 KB14 KB19 KB29 PB06 PB40 PC02 PC06 4J026 AA47 AA48 AC09 AC23 AC35 BA01 BA02 BA03 BA05 BA06 BA07 BA09 BA10 BA19 BA20 BA22 BA27 BA28 BA29 BA30 BA31 BA32 BA36 BA39 BA40 BA43 BA44 BA46 BA47 DA02 DA08 DA12 DA15 DB04 DB08 DB10 DB12 DB13 DB24 DB27 FA07 CG02 GA02 CG141 CR071 CR072 DL101 DL102 GA06 GA08 GA09 GA13 GA14 GA15 KA15 MA08 MA10 NA03 NA04 NA12 NA27 PA19 PB05 4J040 DF011 DF012 DF021 DF022 DN001 DN002 EK101 EK102 GA07 GA13 GA14 GA25 GA28 GA31 JA03 JB02 LA06 LA07 MA08 MA09 AL03T AL08P AL08S BA77P BC04P CA03 CA06 FA03 FA19 JA01 JA03 JA11 JA67

Claims (5)

[Claims] (A1) a monomer containing a cycloalkyl group and having an ethylenic double bond, (A2) a monomer containing an alkoxysilyl group and having an ethylenic double bond, and (A3) an anionic group And (A1): 5 to 99.4% by weight, (A2): 0.1 to 20% by weight, and (A3): 0.5 to 30% by weight of a mixture was copolymerized in an organic solvent, and the organic solvent was replaced with an aqueous medium to obtain (A) a copolymer. In the presence of the (A) copolymer, an acrylic monomer was used. Acrylic monomer / (mixture containing (A1)-(A3)) (weight ratio) ) Is 100/5 to 10 based on the amount used.
0/100 aqueous resin composition. (2) at least a part of the polymer (B) obtained by polymerization of an acrylic monomer is (A1) a monomer containing a cycloalkyl group and having an ethylenic double bond, (A2) alkoxy A monomer having a silyl group and having an ethylenic double bond, and (A3) a monomer having an anion group and having an ethylenic double bond; (A1): 5 to 99.4% by weight (A2): 0.1 to 20% by weight and (A3): 0.5 to 30% by weight, comprising a resin coated by the copolymer (A) obtained by copolymerization. An aqueous resin composition, wherein (B) the polymer / (A) copolymer (weight ratio) is 100 /
An aqueous resin composition having a ratio of 5 to 100/100. 3. The aqueous resin composition according to claim 2, which is produced by the production method according to claim 1. (A1) A monomer containing a cycloalkyl group and having an ethylenic double bond is represented by the following formula: (I): CH ₂ ＣＲCR ¹ —COO—R ² [wherein, in the formula (I), R ¹ represents H, a methyl group or an ethyl group, and R ² represents a cycloalkyl group which may have a substituent. The aqueous resin composition according to any one of claims 1 to 3, wherein (A2) A monomer containing an alkoxysilyl group and having an ethylenic double bond is represented by the following formula: (II): CH ₂ ＣＲCR ³ —COO—Z—Si (OR ⁴ ) ₃ In (II), R ³ represents H or CH ₃ , R ⁴ represents an alkyl group having 1 to 3 carbon atoms, and Z represents an alkylene group having 1 to 6 carbon atoms. The aqueous resin composition according to any one of claims 1 to 4, wherein