JP2003504424A - Coating solvent - Google Patents

Abstract

  (57) [Summary] The coating solvent of the present invention comprises a solvent, an alkyd resin, a residue of a polyfunctional thiol compound having at least three thiol groups, and at least three vinyls each having at least one residue of a monofunctional vinylically unsaturated monomer. And a vinyl star polymer with a chain. Vinyl star polymers are soluble in alkyd resin solutions and provide solutions having lower viscosities than linear acrylic polymers.

Description

Detailed Description of the Invention

The present invention relates to coating solvents. In particular, it relates to coating solvents containing alkyd resins such as are used in solvent-based paints.

Alkyd resins are polyesters obtained from polyhydric alcohols and acids.
The acid is usually a long alkyl chain fatty acid, often derived from acids such as those obtained from naturally occurring fats and alcohols such as glycerol. These alkyd resins are widely used in numerous coating applications such as wood coatings or industrial coatings. Alkyd resins are generally modified with other compounds such as phenolic resins to improve hardness and solvent resistance, epoxy resins to improve adhesion, and silicones to improve heat resistance and thermal shock resistance. Target. For a more detailed description of alkyd resin modifiers, see "Encyclopedia of Polymer Sc.
Ience and Technology, "First Edition, Volume 1, p. 663 (Wiley 1964). Acrylic compounds are also alkyd resin modifiers, for example, durability improvement, color development and color maintenance, gloss improvement,
Used to maintain gloss and reduce drying time of the resulting coating. In order to achieve the modification, the modified resin must be miscible with the alkyd resin and soluble in the carrier system, such as petroleum ether, or xylene. Among the thermoplastic acrylic resins, the low molecular weight linear polyisobutyl methacrylate polymer resin has good solubility in petroleum ether and miscibility with alkyd resins, and therefore, other applications as alkyd resin modifiers, It is known to be commercially desirable over thermoplastic acrylics.

It is an object of the present invention to provide alternative resins suitable for use in alkyd resin systems. The present invention provides a coating solvent containing a solvent, an alkyd resin, and a vinyl star polymer, wherein the vinyl star polymer contains a residue of a polyfunctional thiol compound having at least three thiol groups and an alkyl acrylate or an alkyl ( It has a residue of a polyfunctional thiol compound with at least 3 vinyl chains, which has a residue of at least one monofunctional vinylically unsaturated monomer such as an alkyl (alk) acrylate.

In a second embodiment of the present invention, a residue of a polyfunctional thiol compound having at least three thiol groups, each containing an alkyl acrylate or an alkyl (
Use of a vinyl star polymer with at least three vinyl chains having residues of at least one monofunctional vinylically unsaturated monomer, such as alk) acrylate, as a component of an alkyd resin based coating solvent. .

In a third embodiment of the present invention, a method for producing a coating solvent is provided, which comprises a step of forming an alkyd resin solution or a dispersion of an alkyd resin in a solvent, , A residue of a polyfunctional thiol compound having at least 3 thiol groups and at least 3 vinyls each having a residue of at least one monofunctional vinylically unsaturated monomer, such as an alkyl acrylate or an alkyl (alk) acrylate. And adding a vinyl star polymer with chains and mixing these mixtures to make an acrylic polymer solution.

Polymers having the above-described composition are known as "star" polymers because of the star-shaped morphology of at least three acrylic chains arranged around the hub portion of the thiol derivative. Star polymers are described in International Patent Application Publication No. WO-A-96 / 3.
7520. However, compatibility with an alkyd resin and its use as a modifier for an alkyd resin have not been previously announced or predicted. The above star polymers have better solubility in the solvents used to produce the alkyd resins, such as petroleum ether, and compared to some of the known acrylic type alkyd resin modifying compounds. , Provides better miscibility with alkyd resins. Such a feature is a performance advantage,
For example, it provides a coating formulation having a low viscosity at the time of application, or a high filling property of an acrylic modifier in an alkyd resin.

Vinyl polymers have hub moieties derived from polyfunctional thiol compounds.
The hub portion consists of a core group X and at least three combined groups Y-S. X is a trifunctional to hexafunctional alcohol, for example, at least a part of residues of glycerol, sorbitol, pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, trimethylolpropane, pentahydroxypentane, triquinolyl, and inositol. Is desirable.
The linking group Y is preferably alkylate, especially C _2-10 alkylate, especially C _2-6 alkylate.

The hub portion is preferably a 3- to 8-functional residue, particularly a 3- to 6-functional mercaptan. Such mercaptans include alcohols, thio-C _2-10 alkanoic acids,
In particular, it may be an ester formed from thio-C _2-6 alkanoic acid. Examples of suitable acids are 2-mercaptoacetic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 4-mercaptobutyric acid, 5-mercaptopentanoic acid, 6-mercaptohexanoic acid, and 10-mercaptodecanoic acid. . Preferably the acid is 2
-Mercaptoacetic acid or 3-mercaptopropionic acid.

Examples of compatible polyfunctional mercaptans include trimethylolethane tris (3-mercaptopropionate), pentaerythritol tetra (3-mercaptopropionate), pentaerythritol tetrathioglycolate, trimethylolethane trithiol. Glycolate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane trithioglycolate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane trithioglycolate, pentaerythritol tetrathiolactate , Pentaerythritol tetrathiobutyrate, dipentaerythritol hexa (3-mercaptopropionate), dipentaerythritol hexathioglycolate,
There are tripentaerythritol octa (3-mercaptopropionate) and tripentaerythritol octathioglycolate.

Mixed polymer systems can be prepared, for example, by selecting two or more hub compounds, for example, two or more polyfunctional thiol compounds, or one or more polyfunctional thiol compounds and one or more monofunctional or difunctional compounds. It may be prepared by polymerizing an acrylic monomer to form a chain in the presence of a thiol compound. Suitable monofunctional thiol compounds include propyl mercaptan, butyl mercaptan, hexyl mercaptan, octyl mercaptan, dodecyl mercaptan, thioglycolic acid, mercaptopropionic acid, 2-ethylhexyl thioglycolate, mercaptoethanol, mercaptoundecanoic acid, thiolactic acid, And thiobutyric acid. Suitable bifunctional compounds include glycol dimercaptoacetate, polyethylene glycol di (3-mercaptopropionate), ethylene bis (3-mercaptopropionate), polyethylene glycol dimercaptoacetate.

A mixture of star polymers may be obtained by polymerizing such a mixture, or simply by mixing two or more preformed star polymers, or one with one or more preformed star polymers. It is formed by mixing the above linear vinyl polymers. Such mixtures are very effectively used in the coating according to the invention. The vinyl chains of the vinyl star polymer, or of the linear polymer, respectively, may in the mixture be composed of vinyl monomers which are the same or different vinyl stars or linear polymers from one another.

The vinyl polymer chain is formed from at least one monoolefinically unsaturated monomer selected from known monoolefinically unsaturated monomers. Suitable monofunctional vinylically unsaturated monomers include acrylic monomers such as acrylic acid, methacrylic acid, and chloroacrylic acid (ie CH ₂ = CHClCO.O).
H), acrylamide and methacrylamide, acrylonitrile and methacrylonitrile, alkoxyalkyl acrylamide and methacrylamide such as butoxymethyl acrylamide and methoxymethyl methacrylamide, hydroxyalkyl acrylamide and methacrylamide such as N-methylol acrylamide and methacrylamide, metal. Acrylate and methacrylate, and esters of acrylic acid, methacrylic acid, and chloroacrylic acid with alcohols and phenols; styrene, and its substituted derivatives such as halogenated derivatives and vinyl aromatic compounds such as vinyltoluene; vinyl acetate, etc. It may be selected from vinyl esters and vinylpyrrolidone.

Desirable monofunctional vinylically unsaturated monomers include acrylic acid or methacrylic acid,
And CH ₂ = C (R) CO. Has a molecular formula of OR ² , R is H, methyl or butyl,
In particular methyl, isobutyl or n-butyl, R ² is an optionally substituted hydrocarbon (eg an optionally halogen or hydroxy substituted hydrocarbon), especially C _1-8.
Included are those esters which are alkyl groups, C _6-10 cycloalkyl groups or C _6-10 aryl groups. Examples of such monomers include methylmethacrylate, ethylmethacrylate, n-propylmethacrylate, isopropylmethacrylate, n-butylmethacrylate, isobutylmethacrylate, cyclohexylmethacrylate, isobornylmethacrylate, benzylmethacrylate, phenylmethacrylate, and isobornylacrylate. Unsubstituted esters of acrylic acid and methacrylic acid, and substituted esters of acrylic acid and methacrylic acid, such as hydroxyethyl methacrylate, hydroxypropyl methacrylate. In particular, the monofunctional vinyl unsaturated monomer is
It is a C _1-8 alkyl ester of methacrylic acid. Methyl methacrylate, isobutyl methacrylate, and n-butyl methacrylate are especially desirable monomers.

The at least three vinyl polymer chains are formed from a mixture of monofunctional vinylically unsaturated monomers, such as the monomer mixture described above. Each of the vinyl polymer chains is typically 10 to 1500, for example 25 to 1
It consists of 500 monomer units, preferably 20-800, especially 30-800. When a mixture of monomer units is used, the copolymer is a block or random copolymer of these units. Desirably, the copolymer is a random copolymer produced by conventional free radical polymerization.

Each vinyl polymer chain may be formed by a polymerization process conventionally used in the production of poly (methacrylate) s, using polythiol as the chain transfer agent. Such processes include bulk polymerization of acrylic polymer chains, solution polymerization,
It includes emulsion polymerization and suspension polymerization. Suspension polymerization and bulk polymerization are the preferred processes.

When suspension polymerization is used, the process is typically at least initially 10-120 ° C, preferably 50-110 ° C, especially 70-110 ° C, more preferably about 75-100. It is carried out within the range of ° C. Suitable bulk polymerization processes are conducted at temperatures within the range of 70-130 ° C.

Suitable processes are bulk, solution, emulsion and suspension polymerizations using free radical initiators. Suitable free radical initiators include organic peroxides, hydroperoxides, persulfates, and azo compounds. Examples of such initiators are methyl ethyl ketone peroxide, benzoyl peroxide, cumene hydroperoxide, potassium peroxodisulfate, azobisisobutyronitrile (AIBN), lauroyl peroxide, 2,5-dimethyl-2,5. -Di (t-butylperoxy) hexane, diethyl peroxide, dipropyl peroxide, dilauryl peroxide, distearyl peroxide, di (t-butyl) peroxide, di (t-amyl) peroxide, t
-Butyl hydroperoxide, t-amyl hydroperoxide, acetyl peroxide, propionyl peroxide, lauroyl peroxide, stearoyl peroxide,
Malonyl peroxide, succinyl peroxide, phthaloyl peroxide, acetylbenzoyl peroxide, propynylbenzoyl peroxide, ascaridol, ammonium peroxodisulfate, sodium peroxodisulfate, sodium percarbonate, potassium percarbonate, sodium perborate, potassium perborate, superphosphoric acid Sodium acid salt, potassium perphosphate, tetralin hydroperoxide, t-butyl diperphthalate, t-butyl perbenzoate, 2,4-dichlorobenzoyl peroxide, urea peroxide, caprylyl peroxide (Caprylyl peroxide), p-chlorobenzoyl peroxide, 2,2-bis (t-butylperoxy) butane, and hydroxyheptyl peroxide.

The ratio of the initiator to the polythiol is preferably less than 6: 1 in molar ratio, for example, within the range of 6: 1 to 1: 6, and particularly, the ratio of the initiator to polythiol is 3: 1 in the molar ratio. It is desirable that it is smaller than the above, for example, within the range of 3: 1 to 1: 3. The molar ratio of polythiol to monomer is 1:10 to 1: 300.
It is desirable to be in the range of 0, and it is particularly desirable that the molar ratio of the monomer to the polythiol is in the range of 1:25 to 1: 1500.

When the polymerization process is a lactic acid polymerization process, the emulsifier may be selected from among those commonly used in the art. Such emulsifiers include fatty acid soaps, rosin soaps, sodium lauryl sulfate, polyethoxy alkylated phenols, dioctyl sodium sulfosuccinate, and dihexyl sodium sulfosuccinate.

When a solvent is required for the polymerization process, such solvent may be selected from those commonly used in the art such as benzene, toluene, xylene,
It may be selected from aliphatic esters, aliphatic ethers, aliphatic ketones, and aliphatic alcohols.

The molecular weight of the polymer is controlled by the mercaptans that form the hub of the star polymer. The molecular weight (Mw) is usually 4,000-80,000 Daltons (6.
644 × 10 ^{−24 to} 1.329 × 10 ⁻²² kg), preferably 8,000 to 60,
000D (1.329 × 10 ^{−23 to} 9.966 × 10 ⁻²³ kg).

The acrylic resin is contained in the coating solvent in an amount of 1 to 80% by weight, preferably 1 to 60%.
Present in a concentration of wt%. The ratio of acrylic resin to alkyd resin is typically in the range of 1: 8 to 1: 2 by weight.

The coating solvent typically also contains other ingredients in addition to the alkyd resin, acrylic resin, and solvent. These other ingredients are known in the art of solvent-based coating formulations. Typically these ingredients include a desiccant, for example:
Cobalt, lead, zinc, zirconium, or calcium salts are usually present at a concentration of 0.1 to 1.0% by weight, based on the alkyd resin component of the coating. The coating may include pigments and opacifiers such as titanium dioxide. When pigment is present, the weight ratio of pigment to binder is 1:20 to 1.2: 1.
Is typically used at a concentration that is

The solvent used for such coatings is typically light oil. The total solids concentration in gas oil (ie, all non-volatile components) is typically 40-50%. The coating solvent may contain other ingredients not mentioned above but known in the art of formulating solvent-based coatings.

The invention is described in more detail by the following examples. Example 1 Preparation of Mixed Star Polymer 4.5 g suspension (Natrozole HEC 250LR available from Aquaron Inc., a division of Herculis Incorporated).
Is dissolved in 2.0 l of deionized water in a 5 liter flask by sparging with nitrogen and heating at 40 to 50 ° C. for 30 minutes with gentle stirring. The premixed monomer layer is 500 g of isobutyl methacrylate and dodecyl mercaptan (DDM).
, Trimethylolpropane tris (3-mercaptopropionate) (TRIM
P) and pentaerythritol tetra (3-mercaptopropionate) (PE
TMP) made from 1.75 phm each (a unit of a percentage of the amount of monomer). AIBN using the premix while maintaining a nitrogen blanket and water cooled reflux.
5.0 g of initiator is diluted in deionized water. The temperature is raised to 76 ° C. and the mixture is stirred at a speed of 1500 rpm. Polymerization proceeds until the conversion of monomer to polymer is almost complete, where cooling water to the condenser is stopped.
The polymer is then heat treated for 30 minutes by raising the temperature to within the range of 90-95 ° C to complete the polymerization and remove unreacted monomer. After heat treating the polymer, the nitrogen blanket is removed and the polymer is air cooled. The air cooled polymer is then filtered, washed with deionized water and dried.

The molecular weight of the polymer is measured by gel permeation chromatography (GPC) using chloroform as a solvent and polymethylmethacrylate as a standard sample. The results are shown in Table 1. The dissolution of the polymer in petroleum ether and the viscosity of the resulting solution were calculated and the results are shown in Table 2. Measured molecular weight Mw = 9550 and Mn
Of the commercial thermoplastic solid polyisobutylmethacrylate alkyd resin modifier (denoted as CR in the table) having a value of = 4750 was also measured, demonstrating the properties of the alkyd resin modifier with known acrylic resins in Example 1 and Used to show in comparison with the two polymers.

Example 2 Preparation of Medium-Molecular Weight Star Polymer The procedure of Example 1 was repeated without DDM. Example 3 (Comparative Example) Preparation of Linear Polymer Except that the only mercaptan used was 1.75 phm DDM.
The method of Example 1 was followed. The results show that the polymers described in Examples 1 and 2 are soluble in petroleum ether,
It can be seen that it yields a solution with a relatively low viscosity up to a concentration of% w / w. On the other hand, the linear control (Example 3) cannot be completely dissolved in petroleum ether.

Also, for a given solution viscosity, the resin of Examples 1 and 2 is more soluble than polyisobutylmethacrylate resins to higher solids concentrations (eg, to achieve the use of less solvent). It turns out that it has advantages.

[0029]

[Table 1]

[Table 2] Example 4 Miscibility with Alkyd Resin 1.0 g of each polymer synthesized in Examples 1 to 3 and polyisobutylmethacrylate resin were each added to 9.0 g of several kinds of commercial alkyd resin solutions. Each sample may be left in a water bath at 90 ° C for 6 hours and rotated. After cooling to room temperature, the solubilities are visually evaluated and classified as follows.

[0030] A: Clear solution-insoluble particles are not observed. B: Clear solution-several insoluble particles C: cloudy solution-a small amount of undissolved resin condenses. D: Cloudy solution-a large amount of undissolved resin condenses.   The results are shown in Table 3.

[0031]

[Table 3] These results indicate that the star polymers or partial star polymers of Examples 1 and 2 are miscible with alkyd resins that are at least as good as the known polyisobutyl methacrylate alkyd resin modifiers. The linear polymer of Example 3 generally has low miscibility with these alkyds.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, SD, SL, SZ, TZ, UG, ZW ), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, C U, CZ, DE, DK, EE, ES, FI, GB, GD , GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, KR, KZ, LC, L K, LR, LS, LT, LU, LV, MD, MG, MK , MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, T M, TR, TT, UA, UG, US, UZ, VN, YU , ZA, ZW F-term (reference) 4J038 CC011 CC012 CF021 CF022                       CG011 CG012 CG121 CG122                       CG141 CG142 CG161 CG162                       CG171 CG172 CH031 CH032                       CH041 CH042 CH071 CH072                       CH081 CH082 CH131 CH132                       CK031 CK032 DD231 DD232                       HA156 JA03 JA17 JA26                       JA32 JA53 KA06 NA01 NA02                       NA03 PB06 PB14 PC06                 4J100 AB02P AB04P AG04P AJ02P                       AL03P AL04P AL09P AM02P                       AM15P AM21P AQ08P BA03P                       BA04P BA05P FA06 JA01

Claims (12)

[Claims] 1. A coating solvent comprising a solvent, an alkyd resin, and a vinyl star polymer, wherein the vinyl star polymer comprises a residue of a polyfunctional thiol compound having at least three thiol groups and at least one monofunctional vinyl group. At least three vinyl chains having residues of unsaturated monomers,
Coating solvent. 2. The coating solvent according to claim 1, wherein the polyfunctional thiol compound comprises a core group X and at least three bonding groups Y-S.
Wherein X is at least a part of the residue of a 3 to 6 functional alcohol and the bonding group Y is an alkylate. 3. The coating solvent according to claim 2, wherein the polyfunctional alcohol is glycerol, sorbitol, pentaerythritol, dipentaerythritol, tripentaerythritol, trimethylolethane, trimethylolpropane, pentahydroxypentane, triquinolyl. And a coating solvent selected from inositol. 4. The coating solvent according to claim 2, wherein the bonding group Y is a C _2-10 alkylate. 5. The coating solvent according to any one of claims 1 to 4, wherein the vinyl star polymer is a mixture of two or more vinyl star polymers, and each vinyl star polymer has at least three thiol groups. With different polyfunctional thiol compound residues and at least three vinyl chains, each vinyl chain of each vinyl star polymer being the same or different vinyl monomer as the other respective vinyl star polymer. Coating solvent consisting of composition. 6. The coating solvent according to claim 1, wherein the coating solvent has the same or different vinyl monomer composition as the vinyl monomer composition that constitutes the vinyl chain of each vinyl star polymer. A coating solvent further having a linear vinyl polymer composed of residues of the constitution. 7. The coating solvent according to claim 6, wherein the linear vinyl polymer has a residue of at least one thiol compound having one or two thiol groups. 8. The coating solvent according to any one of claims 1 to 7, wherein the at least one monofunctional vinyl unsaturated monomer is an acrylic monomer, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, alkoxy. Alkyl acrylamide, alkoxy methacrylamide, hydroxyalkyl acrylamide, hydroxyalkyl methacrylamide, metal acrylate, metal methacrylate, ester of acrylic acid and alcohol or phenol, ester of methacrylic acid and alcohol or phenol, chloroacrylic acid and alcohol or phenol Selected from the group of compounds consisting of esters of vinyl aromatic compounds and substituted derivatives thereof, and vinyl esters or mixtures of the compounds mentioned above. Selected coating solvent. 9. The coating solvent of claim 8, wherein the at least one monofunctional vinylically unsaturated monomer is acrylic acid or methacrylic acid,
And CH2 = C (R) CO. Is selected from among the esters having the formula OR ^2, R is H, methyl, or butyl group, R ² is C _1-8 alkyl group optionally substituted, C _6-10 cycloalkyl group, Or a coating solvent which is a C _6-10 aryl group. 10. The coating solvent of claim 9, wherein the at least one monofunctional vinylically unsaturated monomer is a mixture of at least two acrylic or methacrylic acid esters. 11. A vinyl star polymer having residues of a polyfunctional thiol compound having at least three thiol groups and at least three vinyl chains each having at least one residue of a monofunctional vinylically unsaturated monomer. As a component of an alkyd resin coating solvent. 12. A step of forming a diffusion product of an alkyd resin solution or a solvent of an alkyd resin, a residue of a polyfunctional thiol compound having at least three thiol groups, and at least one monofunctional vinyl unsaturated compound. Adding a vinyl star polymer with at least three vinyl chains having monomeric residues,
Mixing a mixture optionally further comprising a component selected from a drying compound, a pigment, and an opacifying agent to form an acrylic polymer solution.