JPH09255728A - Nonionic high-molecular surfactant and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonionic polymer pigment dispersion which is liq. and has a high surface activity, i.e., a high pigment dispersion capability, to provide a water-base or substantially solventless pigment dispersion, and to provide a pigment dispersion suitable for a baking coating. SOLUTION: This nonionic polymer pigment dispersion has a number average mol.wt. of 10,000-200,000 and is obtd. by copolymerizing 40-10wt.% monomer represented by the formula: CH2 =CR<1> COOR<2> (wherein R<1> is H or CH3 ; and R<2> is a 4-22C alkyl), 50-90wt.% monomer represented by the formula: CH2 =CR<1> COO(Cn H2n O)m R<3> (wherein R<1> is H or CH3 ; R<3> H or a 1-4C alkyl; (n) is 1, 2, or 3; and (m) is an integer of 4-25), and 0-50wt.% copolymerizable vinyl monomer. A water-base solventless pigment dispersion is prepd. by dispersing a pigment in the surfactant, and the dispersion is used for a baking coating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nonionic polymer surfactant, and more particularly to an emulsifier, a detergent, a softening agent,
Antistatic agents, solubilizers, compatibilizers, wetting agents, or pigment dispersants, and also nonionic polymer surfactants such as water-based / organic solvent-based / solvent-free pigment dispersions and pigment dispersions for baking paints. Regarding the use of.

[0002]

2. Description of the Related Art Surfactants are used in inks, paints, pressure-sensitive adhesives, and the like to mix substances that are insoluble in constituent resins, such as pigments and carbon black. In recent years, organic solvents such as inks and paints have been decomposed into organic solvents. In this trend, the development of products using water as a solvent instead of an organic solvent has been promoted. The role of surfactants in water-based inks and paints is important. Conventionally, anionic, cationic, nonionic surfactants and the like have been used as surfactants. However, surfactants that have been conventionally used mainly use low-molecular-weight surfactants, and thus, when used in inks, paints, adhesives, etc., adversely affect the physical properties of products after printing or coating. Often had an effect. For ink and paint applications, the hardness after curing decreases. In addition, since it has a low-molecular surface activity, it has properties such as deterioration of water resistance after curing. In particular, when used in water-based paint applications, this problem is a remarkable problem, and research on polymer surfactants has been actively conducted. For example, as polyethylene glycol-based surfactants, there are JP-A-1-171628 and JP-A-5-103969. However, when it was developed for practical use, it did not have sufficient performance for practical use.

[0003] Specifically, the polymer surfactant disclosed in Japanese Patent Application Laid-Open No. 1-171628 does not have a sufficient surfactant ability. Further, the polymer surfactant disclosed in JP-A-5-103969 has copolymerized an ionic monomer in order to balance hydrophilicity / hydrophobicity. For this reason, the surfactant activity is excellent, but when used as a liquid pigment dispersion, the addition of a small amount of an ionic monomer undesirably increases the viscosity of the dispersion. Furthermore, the water resistance was also significantly reduced. That is, the polyethylene glycol portion is easily decomposed when heated and baked in the air,
There is no significant decrease in the water resistance of the coating film after baking. However, when an ionic monomer is used, the water resistance after baking and curing has been reduced. Also,
Some of these ionic monomers have a peculiar odor, which has been a major problem in practical use.

Further, as a pigment dispersion, a masterbatch in which a pigment is dispersed in a resin or a liquid color in which a pigment is dispersed in a solvent is conventionally used. However, when an attempt is made to use the masterbatch dispersion in, for example, a coating resin, the application is limited due to the problem of compatibility between the masterbatch resin and the coating resin.
Also, with regard to liquid color dispersions, the coating systems that can be used are similarly limited due to the compatibility between the solvents.
Further, no solvent-type liquid polymer surfactant, no solvent-type liquid polymer pigment dispersant, or no solvent-type liquid polymer pigment dispersion has been hitherto known.

[0005]

SUMMARY OF THE INVENTION The present invention is a polymer surfactant having excellent properties which solves the problems of the above surfactant. That is, since it is a high molecular weight surfactant, it solves various problems caused by low molecular weight compounds, and since it is a low viscosity nonionic high molecular weight surfactant, it can reduce the amount of solvent used. It is intended to provide a surfactant. Further, the present invention provides a surfactant having a high surface activity and improving the water resistance after curing of a coating film when used as an ink or a paint.

[0006]

The present inventors have synthesized a comb-shaped polymer surfactant having a shape having both hydrophilic side chains and hydrophobic side chains in the polymer chain. Since the nonionic polymer surfactant in the present invention has a high density of hydrophobic and hydrophilic parts in the polymer, it exhibits good performance as a surfactant and further as a pigment dispersant. I found a thing.

Further, in the case of the surfactant of the present invention, since it is a liquid polymer surfactant, it is not only a water-based / organic solvent-based dispersion but also a substantially solvent-free liquid dispersion. It is possible to That is, since the polymer surfactant in the present invention has a comb-shaped resin structure, it is also a characteristic that it is a low-viscosity liquid resin.

That is, the present invention relates to a monomer (A) represented by the following formula: 40 to 10% by weight CH ₂ = C (R ¹ ) COO-R ² (wherein R ¹ is a hydrogen atom or CH ₃ , R ₃ ² is carbon number 4
To 22 alkyl groups. ) Monomer represented by the following formula (B) 55 to 90 wt%, ^{_{and, CH 2 = C (R 1}} ) COO (C n H 2n O) m R 3 ( wherein, R ¹ represents a hydrogen atom or CH ₃ , R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 to 3,
m represents an integer of 4 to 25, respectively. The present invention relates to a nonionic polymer surfactant having a number average molecular weight of 10,000 to 200,000 obtained by copolymerizing 0 to 35% by weight of another polymerizable vinyl monomer (C). It also relates to a liquid nonionic polymer surfactant having a viscosity at 50 ° C of 500 to 100,000 cps. Furthermore, it relates to a pigment dispersion obtained by dispersing a pigment in the above-mentioned polymer surfactant. further,
The present invention relates to a baking paint comprising a binder for baking paint and the above pigment dispersion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The polymeric surfactant in the present invention means a (meth) acrylate having an alkyl group as a hydrophobic group and a (meth) acrylate having a polyethylene glycol chain which is a hydrophilic group. , And, if necessary, other polymerizable monomers are copolymerized.

The monomer (A) used in the present invention has an alkyl group having 4 to 22 carbon atoms, and among them, an acrylate having an alkyl group having 8 to 20 carbon atoms or a corresponding methacrylate is preferred. preferable. At this time, if the carbon number is smaller than 4, the effect as a hydrophobic group cannot be sufficiently exhibited. Further, when the carbon number is larger than 22, the degree of polymerization is difficult to increase and 50
Since it is a solid at ℃, the hydrophobic chain is solidified at a normal temperature, so that it cannot exert a sufficient effect as a surfactant.

Specific examples include 2-ethylhexyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate and heptyl (meth).
Acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth)
Acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, There are alkyl (meth) acrylates having 4 to 22 carbon atoms such as icosyl (meth) acrylate, henicosyl (meth) acrylate, and docosyl (meth) acrylate.

The monomer (B) used in the present invention has a repeating unit having a polyethylene glycol group of 4 to 25. Desirably the number of repetitions
It has 6 to 22 polyethylene glycol groups. At this time, if the number of repetitions is less than 4, the effect as a hydrophilic group cannot be sufficiently exhibited. On the other hand, when the number of repetitions is larger than 26, the hydrophilic chains are solidified at a normal temperature, so that a sufficient effect cannot be exhibited.

Specific examples include tetraethylene glycol (meth) acrylate, methoxytetraethylene glycol (meth) acrylate, ethoxytetraethylene glycol (meth) acrylate, propoxytetraethylene glycol (meth) acrylate and n-butoxytetraacrylate. Ethylene glycol (meth) acrylate, n-pentaxytetraethylene glycol (meth)
Acrylate, tetrapropylene glycol (meth) acrylate, methoxytetrapropylene glycol (meth) acrylate, ethoxytetrapropylene glycol (meth) acrylate, propoxytetrapropylene glycol (meth) acrylate, n-butoxytetrapropylene glycol (meth) acrylate, n- Pentaxytetrapropylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, methoxy polyethylene glycol (meth) acrylate,
Examples include ethoxy polyethylene glycol (meth) acrylate.

The composition ratio of the monomer (A) is 40 to 10% by weight, preferably 40 to 20% by weight, based on the total mass.
Further, the composition ratio of the monomer (B) is 55 to 90 with respect to the total mass.
% By weight, preferably 60-80% by weight. Since these compositions are related to the balance between hydrophilicity and hydrophobicity, the hydrophilicity and hydrophobicity cannot be balanced outside the range, and the ability as surface active cannot be exhibited.

The monomer (C) used in the present invention is
It is a monomer added for the purpose of adjusting the effect as a surfactant or adapting it to inks, paints and other uses. There is no particular limitation on the monomer to be added. For example, styrene and its derivatives can be exemplified in order to improve heat resistance after curing.

The polymer surfactant of the present invention has a number average molecular weight (in terms of polystyrene) measured by GPC (gel permeation chromatograph) of 10,000 to 200,000, preferably by controlling the blending amount of the initiator. , 10,000-150,000
It is synthesized so that it becomes the range of. Number average molecular weight 10,000
When it is smaller, the effect as a polymer surfactant is weaker, and when the number average molecular weight is more than 150,000, especially 200,000, dispersibility is deteriorated. Furthermore, in the case of using a solventless liquid dispersion, the requirements as a liquid are not satisfied, so that the dispersibility is further deteriorated.

The polymeric surfactant used in the present invention is
It can be produced by a known radical polymerization initiator by a solution method or a dispersion method of radical polymerization. The radical polymerization initiator to be used is not particularly limited, but examples thereof include peroxides such as benzoyl peroxide, t-butyl peroxide, cumene hydroperoxide and lauroyl peroxide, azobisisobutyronitrile, azobiscyclohexanenitrile. And the like, and persulfate initiators such as potassium persulfate and ammonium persulfate can be used.
The amount of the radical polymerization initiator is preferably 0.01 to 5% by weight, more preferably 0.1% by weight, based on the total amount of the monomers.
1 to 3% by weight.

The polymerization solvent used in the present invention is not particularly limited as long as it is a solvent capable of radical polymerization. For example, methanol, ethanol, propanol,
Alcohols such as butanol, ethylene glycol, propylene glycol, hydrocarbon solvents such as hexane, heptane, cyclohexane, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as acetone and 2-butanone, tetrahydrofuran, ethyl ether, etc. Ether solvent, cellosolve solvent such as methyl cellosolve, butyl cellosolve, carbitol solvent such as methyl carbitol, ethyl carbitol, benzene, toluene,
Examples include aromatic solvents such as xylene.

The surfactant in the present invention can be used as a solution or suspension, or as the surfactant alone without the solvent. The method for removing the solvent is not particularly limited. For example, there is a method of distilling off the solvent or adding a poor solvent to form a precipitate.

Since the surfactant in the present invention is a liquid polymer surfactant, it can also be used as a substantially solvent-free liquid polymer surfactant or a pigment dispersant. The viscosity of the obtained substantially solvent-free surfactant is preferably from 500 to 100,000 cps at 50 ° C. measured by a rheometer (dynamic viscoelasticity measuring device), more preferably from 800 to 100,000 cps. 50,000 cps. This viscosity range is
When a pigment dispersion without solvent is used, good dispersibility is maintained and handling is easy.

When the surfactant in the present invention is used as a pigment dispersant, the dispersion medium that can be used can be used in both aqueous and organic solvent systems. This dispersion medium is not particularly limited. Further, a substantially solvent-free system using no dispersion medium can be used.

In the present invention, the pigment used as the dispersion is not particularly limited. For example, phthalocyanine, azo, quinacridone, lake, benzimidazolone, anthraquinone, dioxazine, indigo, thioindigo, perylene, perinone, diketopyrrolopyrrole, anthrone, isoindolinone, Organic pigments such as nitro, nitroso, anthraquinone, flavanthrone, quinophthalone, pyranthrone, indanthrone, inorganic pigments such as titanium oxide, carbon black, red iron oxide, zinc oxide and barium sulfate. To be

The method of dispersing the pigment is not particularly limited. For example, a shaking type disperser, a sand mill, a ball mill, a disper, a homogenizer, a three roll, a two roll, a kneader and the like can be mentioned.

There is no particular limitation on the binder in which the dispersion of the present invention can be used. For example, it can be used in both aqueous and organic solvent systems. Further, a substantially solvent-free system can be used. In particular, in the case of a solvent-free liquid dispersion, the range in which a dispersible resin can be used is very wide because no solvent is contained. For example, it can be widely used for acrylic, acrylic, epoxy, urethane, styrene, ester, and alkyd resins.

The use of the dispersion according to the present invention is not particularly limited. For example, it can be used as a pigment dispersion for coating-forming materials such as paints and inks, or for adhesives, pressure-sensitive adhesives, fillers, molding materials, and surface-modifying materials. Among them, when used as a paint or a pigment dispersion for a baking paint, it is particularly preferable because the water resistance of the baking paint is improved by the thermal decomposition of an ethylene glycol portion which is a hydrophilic portion.

The binder for baking paint used in the present invention is not particularly limited. Specifically, it can be used in both aqueous and organic solvent systems. Further, a substantially solvent-free system can be used. Further, acrylic, epoxy, urethane, styrene, ester, alkyd, and other resins can be exemplified. Also, there is no limitation in the application of paint. For example, for metals, for polycarbonate, for resins such as polyethylene terephthalate, and the like.

The baking method is also not particularly limited. For example, a gas oven, an electric oven, an oil oven, a heat circulation oven, a heating roll, etc. are used. Among these, an oven-based heating method is preferable. The heating temperature varies depending on the coating binder used, but is preferably about 80 ° C to 250 ° C.

[0028]

The present invention will be described in more detail with reference to the following examples. The present invention is not limited to the following examples.

The measuring instruments and the like used in the following examples are as follows. The molecular weight was measured by gel permeation chromatography (GPC). (Tosoh SC-8020 / TSKgel GMR-HHR
-N * 3, tetrahydrofuran eluate) Further, as the molecular weight, a value in terms of polystyrene standard was used. The viscosity was measured at 50 ° C. using a rheometer (Rheometrics RFS-II).

The abbreviations used in the following examples are shown below. PEG9MA Methoxy polyethylene glycol methacrylate (m = 9) Shin-Nakamura Chemical M-90G LMA Lauryl methacrylate NP4MA methoxy polyethylene glycol methacrylate (m = 4) Shin Nakamura Chemical M-40G OMA Octyl methacrylate Wako Pure Chemical St Styrene Monomer Tokyo Kasei Pigment Blue LIONOL BULE FG7330 Toyo Ink Mfg. Pigment Red HOSTAPERM PINK E Hoechst

Examples 1 to 14 In a 500 ml four-liter round bottom flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a condenser, the monomer (A), the monomer (B), And the monomer (C) were blended in the composition shown in Table 1 to obtain azobisisobutyronitrile (AIB
N) as an initiator (1% by weight based on the total monomer charge) and refluxed for 5 hours in isopropanol (IPA) solvent (concentration at the time of monomer charge: 30% by weight) to form a viscous resin solution. Was. When the obtained resin solution was allowed to stand while being cooled with ice, it was separated into two layers. After removing the upper layer,
The lower layer was washed with petroleum ether and dried in a vacuum dryer for 12 hours to obtain a polymer surfactant. GPC of the obtained liquid resin
Number average molecular weight (Mn) in terms of styrene and 50 ° C
Was measured. Table 1 shows the results of these measurements.

Comparative Example Comparative Example 1 Stirrer, thermometer, reflux condenser, dropping funnel and N
While charging 670 g of methanol and 103 g of water into a 3 liter flask equipped with a 2 gas introduction tube and introducing N 2 gas, at 70 ° C.
With methoxypolyethylene glycol methacrylate (PEG9MA) 200g, acrylic acid 50g, butyl acrylate 20
A monomer mixture of 0 g and methyl acrylate 75 Og was added dropwise to obtain asobis (2-methylpropaneamidine) hydrochloride (W-50, Wako Pure Chemical Industries) 2. Polymerization was carried out using 75 g.
The obtained polymer was purified by a reprecipitation method using petroleum ether, and dried in a vacuum dryer for 12 hours to obtain a polymer surfactant. The measurement results are also shown in Table 1.

Table 1 No (B) / (A) (C) (B) :( A) :( C) Mn (* 104) (cps) ──────────────── ─────────────────── Example 1 PEG9MA / LMA --- 85: 15: 0 1.0 17800 Example 2 PEG9MA / LMA --- 80: 20: 0 1.1 17300 Example 3 PEG9MA / LMA --- 75: 25: 0 1.2 16800 Example 4 PEG9MA / LMA --- 70: 30: 0 1.1 16300 Example 5 PEG9MA / LMA --- 65: 35: 0 1.0 17100 Example Example 6 PEG9MA / LMA --- 60: 40: 0 1.1 18000 Example 7 PEG4MA / LMA --- 85: 15: 0 1.0 68000 Example 8 PEG4MA / LMA --- 80: 20: 0 1.1 82000 Example 9 PEG4MA / LMA --- 75: 25: 0 1.2 86000 Example 10 PEG9MA / OMA --- 70: 30: 0 1.1 62000 Example 11 PEG9MA / OMA --- 65: 35: 0 1.0 72000 Example 12 PEG9MA / OMA --- 60: 40: 0 1.1 81000 Example 13 PEG9MA / LMA St 65:25:10 1.0 65000 Example 14 PEG9MA / LMA St 65:20:15 1.0 96000 Comparative Example 1 11.0 Solid ──────────────────────────────────

Pigment Dispersibility Test The pigment dispersibility test was conducted by the following method. Production Example of Aqueous Dispersion In a 70 ml mayonnaise bottle, 1 g of the polymer surfactant synthesized according to the example, 15 g of glass beads, 20 g of water, and 4 g of a pigment were added,
Stirring was carried out for 2 hours with a Red Devils shaking stirrer.
After that, apply it on the PET film with bar coater No. 3,
After drying, the degree of dispersion was visually compared.

Table 2 No. Activator Pigment Dispersion Results ─────────────────────── Example 15 Example Blue ◎ Example 16 Example 2 Blue ◎ Example 17 Example 3 Blue ◎ Example 18 Example 4 Blue ◎ Example 19 Example 5 Blue ◎ Example 20 Example 6 Blue ◎ Example 21 Example 7 Blue ◎ Example 22 Example 8 Blue ◎ Example 23 Example 9 Blue ◎ Example 24 Example 10 Blue ◎ Example 25 Example 11 Blue ◎ Example 26 Example 12 Blue ◎ Example 27 Example 13 Blue ◎ Example 28 Example 14 Blue ◎ Example 29 Implementation Example 1 Red ○ Example 30 Example 2 Red ○ Example 31 Example 3 Red ○ Example 32 Example 4 Red ○ Example 33 Example 5 Red ○ Example 34 Example 6 Red ○ Example 35 Example 7 Red ○ Example 36 Example 8 Red ○ Example 37 Example 9 Red ○ Example 38 Example 10 Red ○ Example 39 Example 11 Red ○ Example 40 Example 12 Red ○ Example 41
Example 13 Red ○ Example 42 Example 14 Red ○ Comparative Example 2 Comparative Example 1 Blue △ Comparative Example 3 Comparative Example 1 Red △ ───────────────────── ─ Excellent, ○ good, △ acceptable, × not acceptable

Preparation Example of Solvent-free Dispersion 20 g of pigment, 20 g of polymeric surfactant synthesized according to the example
Were mixed and kneaded once with a three-roll mill, and the resulting pigment dispersion was checked for dispersibility with a grind gauge.

Table 3 No. Activator Pigment Dispersion Results ──────────────────────── Example 41 Example 1 Blue ○ Example 42 Example 2 Blue ○ Example 43 Example 3 Blue ○ Example 44 Example 4 Blue ○ Example 45 Example 5 Blue ○ Example 46 Example 6 Blue ○ Example 47 Example 7 Blue ○ Example 48 Example 8 Blue ○ Example 49 Example 9 Blue ○ Example 50 Example 10 Blue ○ Example 51 Example 11 Blue ○ Example 52 Example 12 Blue ○ Example 53 Example 13 Blue ○ Example 54 Example 14 Blue ○ Comparative Example 4 Comparative Example 1 Blue × ──────────────────────── ◎ Excellent, ○ Good, △ Acceptable, × Not acceptable

Suitability test for baking paint In the resin suitability test for baking paint, the polymer dispersant of the present invention was used as a pigment dispersion of a baking-type beverage can paint (water-based acrylic), and a paint was trial-produced. The trial paint was applied on an aluminum plate with a 0.5 mil applicator. It was baked in an electric oven at 150 ° C for 5 minutes. After baking, a retort resistance test was conducted with 120 ° C. steam and the results are shown.

Table 4 No. Activator Pigment Results ────────────────────── Example 55 Example 1 Blue ○ Example 56 Example 6 Blue ○ Implementation Example 57 Example 8 Blue ○ Example 58 Example 13 Blue ○ Comparative Example 5 Comparative Example 1 Blue × ────────────────────── ◎ Excellent, ○ Good , △ Acceptable, × Impossible

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a nonionic liquid polymer surfactant which is liquid and has a high surfactant as compared with conventionally used polymer surfactants. Became. Furthermore, this surfactant has a good pigment dispersibility, and since it is a water-based pigment dispersant, it can be used as a solvent-free pigment dispersant. Further, the surfactant in the present invention has good suitability for baking paint, and it was possible to provide a surfactant for baking paint.

Claims (5)

[Claims] 1. A monomer (A) represented by the following formula: 40 to 10% by weight, CH ₂ ═C (R ¹ ) COO—R ² (wherein R ¹ is a hydrogen atom or CH ₃ and R ² is Carbon number 4
To 22 alkyl groups. ) Monomer represented by the following formula (B) 55 to 90 wt%, ^{_{and, CH 2 = C (R 1}} ) COO (C n H 2n O) m R 3 ( wherein, R ¹ represents a hydrogen atom or CH ₃ , R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, n is an integer of 1 to 3,
m represents an integer of 4 to 25, respectively. ) A nonionic polymer surfactant having a number average molecular weight of 10,000 to 200,000 obtained by copolymerizing 0 to 35% by weight of another polymerizable vinyl monomer (C). 2. The liquid nonionic polymer surfactant according to claim 1, which has a viscosity at 500C of 500 to 100,000 cps. 3. A pigment dispersion obtained by dispersing a pigment in the polymer surfactant according to claim 1. 4. The pigment dispersion according to claim 3, which is substantially solvent-free. 5. A baking paint comprising a binder for baking paint and the pigment dispersion according to claim 3 or 4 blended therein.