KR101252067B1 - Fumarate diester copolymer - Google Patents

Abstract

The fumaric acid diester copolymer according to the present invention includes a structural unit (a1) derived from a fumaric acid diester monomer, a structural unit (a2) derived from a styrene monomer, and a structural unit derived from an α, β-unsaturated monocarboxylic acid. (a3) and a structural unit (a4) derived from (meth) acrylic acid hydroxyalkyl ester, the copolymer has a weight average molecular weight of 5,000 to 60,000 and the proportion of structural unit (a3) in the copolymer The molar equivalent of the carboxyl group is set to an amount of 220 to 1130 g / mol.

Description

Fumaric acid diester copolymer {FUMARATE DIESTER COPOLYMER}

The present invention relates to fumaric acid diester copolymers and, for example, to fumaric acid diester copolymers which can be used as curing agents for paints, inks, adhesives, printing materials and the like. The fumaric acid diester copolymer refers to a copolymer having fumaric acid diester as one structural unit of the copolymer.

Conventionally, thermosetting resin compositions used in paints, inks, adhesives, printing materials and the like form a chemical bond by heating a compound having a carboxyl group or a hydroxyl group and a compound having a functional group such as an epoxy group, an isocyanate group or an alkoxysilane group to form a chemical bond. Known. Since the hardened | cured material obtained by using this reaction has the advantage that it is excellent in adhesiveness with a base material (for example, the object to apply | coat the said paint etc.), the said reaction is employ | adopted in many fields.

For example, patent document 1 discloses the acrylic resin which has a structural unit which protected the carboxyl group of methacrylic acid with vinyl ether, and the thermosetting resin composition containing an epoxy resin. Although the hardened | cured material obtained by heating this thermosetting resin composition has the characteristic that it is excellent in weather resistance, there existed a problem that adhesiveness with respect to a base material is inferior.

Further, Patent Document 2 discloses a coating composition containing a vinyl copolymer having a structural unit formed of an acryl-based monomer containing dicyclohexyl fumarate, styrenes and hydroxyl groups, and a polyisocyanate. Although the cured film formed from this coating composition has favorable sclerosis | hardenability and weather resistance, since the main chain skeleton derived from fumaric acid diester and styrene in a vinyl-type copolymer is firm, it does not interact with a base material, and adhesiveness with respect to a base material is inadequate. There was.

In order to solve this problem, in the copolymer used for the curing agent such as paints, inks, adhesives, printing materials, a cured film having excellent adhesion to the substrate is required while maintaining the cured film properties such as curability and weather resistance The inventors have come to know.

Japanese Patent Laid-Open Publication No. 4-218561 Japanese Patent Laid-Open Publication No. 3-62867

An object of the present invention is to provide a fumaric acid diester copolymer which is excellent in adhesion to a substrate and suitably used as a curing agent for paints, inks, adhesives, printing materials, etc., while maintaining cured film properties such as curability and weather resistance. To provide.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, it turned out that the fumaric acid diester copolymer which has a specific structural unit can solve the said subject, and came to complete this invention.

The fumaric acid diester copolymer according to the present invention is composed of structural units (a1) to (a4) represented by the following Chemical Formulas 1 to 4, and has a weight average molecular weight of 5,000 to 60,000. The ratio of structural unit (a3) is the quantity of 220-1130 g / mol in molar equivalent of the carboxyl group in the said fumaric acid diester copolymer.

(In formula, each of R <^1> and R <^2> is a C3-C8 branched alkyl group, a C4-C12 cycloalkyl group, or a substituted branched cycloalkyl group.)

(Wherein, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a C6-C12 aromatic hydrocarbon group)

(Wherein R ⁵ is a hydrogen atom, a methyl group or a carboxymethyl group)

(Wherein R ⁶ is a hydrogen atom or a methyl group, R ⁷ is a hydroxyalkyl group having 2 to 4 carbon atoms)

The ratio of the structural unit in 100 mass% of the copolymer is (a1) 10 to 60 mass%, (a2) 5 to 50 mass%, (a3) 5 to 25 mass% and (a4) 5 to 50 mass%, respectively. desirable.

According to the present invention, a fumaric acid diester copolymer which is excellent in adhesiveness to a substrate and preferably used as a curing agent for paints, inks, adhesives, printing materials, etc., while maintaining cured film properties such as curability and weather resistance is excellent. Can provide.

1 is a ¹ H-nuclear magnetic resonance spectrum diagram of a fumaric acid diester copolymer obtained in Example 6 of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

<Fumarate diester copolymer>

The fumaric acid diester copolymer (hereinafter, also simply referred to as a copolymer) of the present embodiment is constituted by structural units (a1) to (a4) represented by the following Chemical Formulas 1 to 4, and has a weight average molecular weight of 5,000 to 60,000. . The ratio of structural unit (a3) is the quantity of 220-1130 g / mol in molar equivalent of the carboxyl group in the said copolymer.

(Formula 1)

(In formula, each of R <^1> and R <^2> is a C3-C8 branched alkyl group, a C4-C12 cycloalkyl group, or a substituted branched cycloalkyl group.)

(Formula 2)

(Wherein, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a C6-C12 aromatic hydrocarbon group)

(Formula 3)

(Wherein R ⁵ is a hydrogen atom, a methyl group or a carboxymethyl group)

(Formula 4)

(Wherein R ⁶ is a hydrogen atom or a methyl group, R ⁷ is a hydroxyalkyl group having 2 to 4 carbon atoms)

The structural units (a1) to (a4) are each derived from monomers represented by the following formulas (5) to (8).

[Wherein, R ¹ and R ² are the same as those in the general formula (1), respectively.]

[Wherein, R ³ and R ⁴ are the same as those in the general formula (2).]

[Wherein, R ⁵ is the same as in formula (3).]

[Wherein, R ⁶ and R ⁷ are the same as those in the general formula (4).]

The weight average molecular weight of the fumaric acid diester copolymer is 5,000 to 60,000, preferably 5,000 to 30,000, more preferably 8,000 to 25,000. When this weight average molecular weight is less than 5,000, there exists a possibility that the weather resistance of the cured film obtained by hardening a copolymer may become inadequate, and when it exceeds 60,000, the cured film may become cloudy at the time of hardening reaction.

Next, the structural units (a1), (a2), (a3) and (a4) will be described in order.

<Unit of unit (a1)>

The structural unit (a1) is derived from fumaric acid diester monomers. This monomer is derived from this monomer because the substituents (COOR ¹ and COOR ² in Chemical Formula 1) of the monomer are directly bonded on the carbon constituting the ethylenically unsaturated bond without having a methylene group or the like on the part of the main chain structure. The structural unit (a1) to be introduced may introduce a rigid main chain structure into the copolymer.

Each of R ¹ and R ² in Chemical Formula 1 is a C3-C8 branched alkyl group, a C4-C12 cycloalkyl group, or a substituted branched cycloalkyl group. R ¹ and R ² are preferably a branched alkyl group having 3 to 6 carbon atoms, a cycloalkyl group having 6 to 10 carbon atoms, or a substituted branched cycloalkyl group. R ¹ and R ² are more preferably a branched alkyl group of 3 to 5 or a cycloalkyl group of 6 to 8 carbon atoms.

When carbon number of a branched alkyl group exceeds 8, the polymerization property at the time of preparing a copolymer may fall, and may cause a problem. Moreover, when carbon number of a cycloalkyl group or a substituted branched cycloalkyl group exceeds 12, the adhesiveness of the cured film with respect to a base material may become inadequate. R ¹ and R ² in Chemical Formula 1 may be the same substituent, or may be a different substituent. It is preferable that R <^1> and R <^2> are the same substituents from each other from the point of availability.

Preferably the ratio of the structural unit (a1) in 100 mass% of copolymers is 10-60 mass%, More preferably, it is 13-57 mass%. When the ratio of the structural unit (a1) is less than 10% by mass, the main chain structure of the copolymer is less likely to be intact and the adhesion of the cured film to the substrate is insufficient. On the other hand, when it exceeds 60 mass%, there exists a possibility that the copolymerization property of the monomer which guide | induces another structural unit at the time of superposition | polymerization may worsen, and the distribution of copolymerization composition may arise.

<Unit of unit (a2)>

The structural unit (a2) has a structure of an aromatic hydrocarbon group in the structural unit. Monomers such as styrene-based monomers for inducing structural unit (a2) include (meth) acrylic acid hydroxyalkyl esters for inducing structural unit (a3) and α, β-unsaturated monocarboxylic acids or structural unit (a4). Since the copolymerizability of the copolymer is good, a copolymer having no bias in the composition distribution can be provided by copolymerizing the structural units having different polymerizability smoothly.

In Formula 2, R ³ is a hydrogen atom or a methyl group, and R ⁴ is an aromatic hydrocarbon group having 6 to 12 carbon atoms. R ³ is preferably a hydrogen atom, and R ⁴ is preferably an aromatic hydrocarbon group having 6 to 10 carbon atoms. When carbon number of R <^4> exceeds 12, there exists a problem that adhesiveness of the cured film with respect to a base material becomes inadequate.

Preferably the ratio of the structural unit (a2) in 100 mass% of copolymers is 5-50 mass%, More preferably, it is 8-50 mass%. When the ratio of structural unit (a2) is less than 5 mass%, there exists a possibility that the copolymerization property of the monomer which guide | induces another structural unit at the time of superposition | polymerization may worsen, and the copolymer composition distribution may be biased. On the other hand, when more than 50 mass%, there exists a possibility that the crystallinity of the molecular chain of a copolymer may become high too much and the adhesiveness of the cured film with respect to a base material will become inadequate.

<Unit of unit (a3)>

Structural unit (a3) is a structural unit derived from the (alpha), (beta)-unsaturated monocarboxylic acid, and can introduce a carboxyl group in a copolymer. For this reason, the fumaric acid diester copolymer is heated in combination with a compound having a functional group such as an epoxy group, an isocyanate group or an alkoxysilane group, thereby heating a chemical bond between the functional group and the carboxyl group introduced by the structural unit (a3). Can be formed.

R ⁵ in Formula 3 is a hydrogen atom, a methyl group or a carboxymethyl group, preferably a hydrogen atom or a methyl group. When using structural units other than the above as R <^5> , copolymerization with the monomer which derives another structural unit will no longer be obtained.

The ratio of the structural unit (a3) in the copolymer is 220 to 1130 g / mol, preferably 280 to 1130 g / mol, more preferably 370 to 810 g / mol, in terms of molar equivalents of the carboxyl groups in the copolymer. The molar equivalent of the carboxyl group in a copolymer can be confirmed by measuring the acid value of the whole copolymer. If this molar equivalent exceeds 1130 g / mol, a copolymer will not have sufficient sclerosis | hardenability, and if molar equivalent is less than 220 g / mol, the weather resistance of a cured film will fall.

Moreover, the ratio of the structural unit (a3) in 100 mass% of copolymers becomes like this. Preferably it is 5-25 mass%, More preferably, it is 6-23 mass%. If the proportion of the structural unit (a3) is less than 5% by mass, the copolymer may not have sufficient curability. If the proportion of the structural unit (a3) is greater than 25% by mass, the weather resistance of the cured film may be lowered.

<Unit of unit (a4)>

Structural unit (a4) is a structural unit derived from the (meth) acrylic-acid hydroxyalkyl ester, and is a component which contributes to the adhesiveness of the cured film with respect to a base material. R ⁶ in Formula 4 is a hydrogen atom or a methyl group, R ⁷ is a hydroxyalkyl group having 2 to 4 carbon atoms. R ⁶ is preferably a methyl group, and R ⁷ is preferably a hydroxyalkyl group having 2 to 3 carbon atoms. When carbon number of R <^7> exceeds 4, the adhesiveness of the cured film with respect to a base material may fall and may cause a problem.

The proportion of the structural unit (a4) in 100% by mass of the copolymer is preferably 5 to 50% by mass, more preferably 7 to 49% by mass. When the ratio of the structural unit (a4) is less than 5% by mass, the weather resistance of the cured film is lowered. When the ratio of the structural unit (a4) is more than 50% by mass, there is a possibility that the polymerizability may be lowered when preparing the copolymer.

<Preparation of fumaric acid diester copolymer>

The copolymer is obtained by copolymerizing the monomers represented by the formulas (5) to (8) by, for example, solution polymerization. Generally known solvents can be used as the polymerization solvent to be used at the time of this copolymerization. As a specific example of such a solvent, Ethylene glycol monoalkyl ether, such as ethylene glycol monomethyl ether and ethylene glycol monoethyl ether; Ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; Diethylene glycol dialkyl ethers such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol methyl ethyl ether; Propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether and propylene glycol monoethyl ether; Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; Lactic acid esters such as methyl lactate and ethyl lactate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone, 2-heptanone and cyclohexanone; Amides such as N, N-dimethylacetamide and N-methylpyrrolidone; Lactones, such as (gamma) -butyrolactone, etc. are mentioned. These solvents can be used individually or in mixture of 2 or more types.

As a polymerization initiator used for polymerizing the said monomer, what is generally known as a radical polymerization initiator can be used. Specific examples thereof include an azo polymerization initiator, an azo polymerization initiator having no cyano group, an organic peroxide, hydrogen peroxide, and the like. When a peroxide is used as a radical polymerization initiator, it can be used as a redox-type polymerization initiator in combination with this and a reducing agent.

When polymerizing the monomer, a molecular weight regulator can be used to control the weight average molecular weight. Examples of the molecular weight regulator include mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, tert-dodecyl mercaptan, thioglycolic acid, and mercaptopropionic acid; Xanthogens such as dimethyl xanthogen disulfide and diisopropyl xanthogen disulfide; Terpinolene,? -Methylstyrene dimer, and the like.

The weight average molecular weight of the fumaric acid diester copolymer can be adjusted by a known method in addition to adding the molecular weight modifier. Specifically, it can adjust by optimizing the temperature at the time of a polymerization reaction, the density | concentration of the monomer at the time of polymerization, the kind and concentration of a polymerization initiator. As the polymerization method, in addition to the solution polymerization method, a known polymerization method such as a bulk polymerization method, a suspension polymerization method or an emulsion polymerization method can be adopted.

(Example)

Hereinafter, the embodiment will be described in more detail with reference to Examples and Comparative Examples. "Part" and "%" are both mass parts and mass% unless there is particular notice. Hereinafter, the measuring method and evaluation method which were used by the Example and the comparative example are shown.

[Acid value]

The acid value is based on JIS K0070: 1992 "Test methods for acid value, saponification value, ester value, iodine value, hydroxyl value and unsaponifiable matter of chemicals" in tetrahydrofuran (THF) solution. A certain amount of copolymer was dissolved, and titrated with potassium hydroxide / ethanol solution using phenolphthalein as an indicator, and measured.

[Weight average molecular weight]

The weight average molecular weight (Mw) uses the gel permeation chromatography apparatus HLC-8220GPC manufactured by Toso Corporation, SHODEX K801 manufactured by Showa Electric Co., Ltd. as a column, THF as the eluent, It calculated | required by conversion using the analytical curve obtained by measuring by the polystyrene standard of molecular weight known.

&Lt; Example 1 >

540.0 g of ethyl lactate (EL) was injected into a 1000 mL four-necked flask equipped with a thermometer, a stirrer, and a cooling tube, and nitrogen-substituted, and the temperature of the liquid was raised to 85 ° C in an oil bath.

On the other hand, 26.8 g of diisopropyl fumarate, 12.8 g of acrylic acid, 63.2 g of α-methylstyrene, 97.2 g of 2-hydroxyethyl methacrylic acid, and 2,2'-azobisisobutyronitrile [azo-based polymerization initiator, Wakochet Yaku Industries Co., Ltd.] After uniform mixing of 10.0 g and EL 60.0 g in advance (dropping component) over a dropping funnel over 2 hours, the mixture was kept at the same temperature for 8 hours to obtain a copolymer.

&Lt; Examples 2 to 6 >

The copolymer was synthesize | combined by the method similar to Example 1 except having changed the kind and quantity of injection | pouring described in Table 1, dripping, and polymerization temperature.

The meaning of abbreviation in Table 1 is as follows.

DcHF: Dicyclohexyl fumaric acid

DiPF: Diisopropyl Fumarate

DsBF: disecbutyl fumarate

St: Styrene

αMeSt: α-methylstyrene

MAA: methacrylic acid

AA: Acrylic acid

HEMA: 2-hydroxyethyl methacrylate

HPMA: Methacrylic Acid Hydroxypropyl

MMA: Methyl methacrylate

Hex-O: t-hexyl peroxy-2-ethylhexanoate, peroxide-based polymerization initiator "Perhexyl O" manufactured by Nichiyu Co., Ltd.

Bu-O: t-butyl peroxy-2-ethylhexanoate, peroxide polymerization initiator "Perbutyl O" manufactured by Nichiyu Co., Ltd.

AIBN: 2,2'- azobisisobutyronitrile [Azo type polymerization initiator, Wako Pure Chemical Industries, Ltd. manufacture]

PGMEA: propylene glycol monomethyl ether acetate

EL: ethyl lactate

&Lt; Comparative Example 1 &

334.3 g of propylene glycol monomethyl ether acetate (PGMEA) was injected into a 1000 mL four-necked flask equipped with a thermometer, a stirrer, and a cooling tube, and after nitrogen replacement, the temperature was raised to 80 ° C in an oil bath.

Meanwhile, 30.6 g of methacrylic acid, 109.4 g of methyl methacrylate, 60.0 g of methacrylate hydroxypropyl, 10.0 g of an azo polymerization initiator ("AIBN" manufactured by Wako Pure Chemical Industries, Ltd.) and 60.0 g of PGMEA were uniformly prepared in advance. The mixture (dripping component) was dropped at constant velocity over the dropping funnel over 2 hours, and then maintained at the same temperature for 8 hours to obtain a copolymer.

Next, the compound (resin) obtained in Example 6 was reprecipitated to 10 masses of n-hexane, and then the compound was identified using a resin powder obtained by recovering under reduced pressure and drying under reduced pressure. It was determined. It shows below about the identification method of a compound.

[Infrared absorption spectrum measurement]

The infrared absorption spectrum (IR) was produced by the purification method using potassium bromide using Nippon Bunco Co., Ltd. product, FT / IR-600, and measured on the conditions of resolution 4cm <^-1> , 32 times of integration times.

[Nuclear magnetic resonance spectrum measurement]

Nuclear magnetic resonance spectrum (NMR) was carried out by Nippon bulka (Co., Ltd.), 400MHz of the advanced type 400 a, the ^first measurement of H-NMR by dissolving the resin powder in CDCl ₃ using a TMS-containing. The measurement result of this ¹ H-NMR is shown in FIG.

From the measurement results of the infrared absorption spectrum, the following absorption was observed. Around 3400 cm ^-1 : hydroxyl group (-OH), 3000-2800 cm ^-1 : methylene group (-CH _2- ) or methyl group (-CH ₃ ), 1730 cm ^-1 : carbonyl group (> C = O), 1170 cm ^-1 : ester Group (-COO), 760, 700 cm ^-1 : aromatic ring (-CH or C = C).

Moreover, the following peaks were seen in the nuclear magnetic resonance spectral diagram shown in FIG. Around 7.1ppm: Aromatic ring proton of styrene, around 4.8ppm: methine proton of sec-butyl group of DsBF, around 2.7ppm: methine proton of DsBF in main chain, 0.9-2.0 ppm: methine of main chain or side chain of copolymer, methylene Or methyl proton.

From the measurement results of the above infrared absorption spectrum and nuclear magnetic resonance spectrum, it was confirmed that all the structural units of (a1) to (a4) were copolymerized in the copolymer obtained by the above synthesis method.

The copolymer shown in Examples 1-6 and bisphenol-A epoxy resin (Japan Epoxy Resin Co., Ltd. product, jER828) were mix | blended so that the functional group equivalent of a carboxyl group and an epoxy group might be the same, and the coating liquid was produced. The coating solution was applied onto a glass substrate using a bar coater and baked at 200 ° C., whereby the obtained cured film exhibited excellent adhesion and weather resistance. Therefore, the copolymer is suitable as a curing agent for epoxy resins. On the other hand, the cured film obtained using the copolymer shown in the comparative example 1 is inferior to adhesiveness and weather resistance.

Claims (2)

A fumaric acid diester copolymer composed of structural units (a1) to (a4) represented by the following Chemical Formulas 1 to 4 and having a weight average molecular weight of 5,000 to 60,000, wherein the proportion of structural unit (a3) is in the copolymer Fumaric acid diester copolymer, characterized in that the amount of 220 to 1130g / mol in the molar equivalent of the carboxyl group.
(Formula 1)

(In formula, each of R <^1> and R <^2> is a C3-C8 branched alkyl group and a C4-C12 cycloalkyl group.)
(2)

(Wherein, R ³ is a hydrogen atom or a methyl group, and R ⁴ is a C6-C12 aromatic hydrocarbon group)
(Formula 3)

(Wherein R ⁵ is a hydrogen atom, a methyl group or a carboxymethyl group)
(Formula 4)

(Wherein R ⁶ is a hydrogen atom or a methyl group, R ⁷ is a hydroxyalkyl group having 2 to 4 carbon atoms)
The method of claim 1,
The ratio of the structural unit in 100 mass% of said copolymers is (a1) 10-60 mass%, (a2) 5-50 mass%, (a3) 5-25 mass%, and (a4) 5-50 mass%, respectively. Fumaric acid diester copolymer, characterized in that.

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