JPS6051483B2 - Method for producing resin for solvent-volatile paints - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a solvent-volatile paint resin, which comprises reacting an acrylic copolymer having a carboxyl group in its side chain with a linear monoepoxy alkane. be.

Acrylic solvent-based paints generally have excellent weather resistance and gloss retention, but on the other hand, they have poor pigment dispersibility, and if the monomer composition is changed to have sufficient flexibility, the resulting This results in a decrease in gasoline resistance.

In order to improve these drawbacks, a method is known in which a copolymer having a carboxyl group in the side chain is reacted with a monoglycidyl compound. For example, Tokuko Sho 39-1989 &
and Special Publication No. 45-13233.

However, even if pigment dispersibility can be improved using these methods, it is difficult to provide sufficient flexibility without deteriorating gasoline resistance. An object of the present invention is to provide a solvent-volatile paint resin that has excellent gasoline resistance, flexibility, and pigment dispersibility.

In order to provide sufficient flexibility to acrylic paint resins, there is a method of copolymerizing long-chain alkyl esters of acrylic acid or methacrylic acid, but this method has low gasoline resistance due to the influence of long-chain alkyl groups. and the pigment dispersibility is not sufficient.

Furthermore, there is a method in which a monoglycidyl compound is reacted with a copolymer having a carboxyl group in the side chain, but although this method improves gasoline resistance and pigment dispersibility, it suffers from the disadvantages mentioned above in terms of flexibility. This method is considerably inferior to the method of copolymerizing monomers with chain alkyl groups, and if monoglycidyl compounds with longer chain alkyl groups are used to increase flexibility, gasoline resistance will decrease. There is a drawback to doing so. As described above, gasoline resistance, pigment dispersibility, and flexibility are contradictory properties, and it has been difficult to have both properties at the same time. As a result of our studies on these points, the present inventors found that introduction of hydrophilic groups is effective in improving gasoline resistance and pigment dispersibility, and introduction of long-chain alkyl groups is effective in increasing flexibility. found to be effective,
The present invention has now been completed.

According to the present invention, a: methyl methacrylate 20-9 weight%, styrene 0-7 weight%, the total weight of both is 60-9 weight%, b: acrylic acid and/or methacrylic acid 4-2 weight%
Saliva amount %, c Monomer copolymerizable with these 0 to 3 amount %
A part or all of the side chain carboxyl groups of the copolymer are reacted with one or a mixture of two or more linear monoepoxy alkanes having 6 to 22 carbon atoms in the presence of a catalyst. By introducing a long-chain alkyl group having a hydroxyl group into the side chain, a resin with excellent gasoline resistance, pigment dispersibility, and flexibility can be obtained.

The chemical formula for this reaction is as follows. (R1,
(R2 is hydrogen or a straight-chain alkyl group, and the total number of carbon atoms in R1 and R2 is 4 to 2) The amount of methyl methacrylate in the present invention is preferably 20 to 9% by weight based on the total monomer, If the amount is less than 2%, weather resistance will decrease.

The amount of styrene is preferably 0 to 7% of the total monomers,
If it exceeds 76% by weight, the compatibility with cellulose resin will decrease. The total amount of methyl methacrylate and styrene must be 60 to 9% by weight based on the total monomers, and if it is less than 6% by weight, hardness and stain resistance will decrease. The amount of acrylic acid and/or methacrylic acid is 4 to 2 of the total monomers.
Saliva content %, preferably 6 to W weight % is appropriate, and if it is less than 4 weight %, long chain alkyl group having hydroxyl group obtained by reacting linear monoepoxy alkane with side chain carboxyl group of copolymer. Since the amount of sulfuric acid decreases, it becomes difficult to achieve the gasoline resistance, pigment dispersibility, and flexibility that are the characteristics of the present invention, and when the amount exceeds 2%, hardness and stain resistance decrease. In addition, methacrylic esters other than methyl methacrylate, acrylic esters, and vinyl. It is permissible to use 0 to 3 weight percent of the monomer as a copolymerization component as long as it does not reduce the performance of the coating resin. Such monomers include acrylic esters of alkanols having 1 to 22 carbon atoms, methacrylic esters of alkanols having 2 to 22 carbon atoms, vinyl acetate, vinyl propionate, vinyl toluene, acrylamide. , methacrylamide, etc. The copolymerization reaction in the present invention can be carried out by a known method of polymerizing methyl methacrylate or styrene.

That is, in the presence of a polymerization initiator such as a peroxide or an azo compound, the temperature is 50 to 200°C, preferably 70 to 100°C.
It is carried out in solution at a temperature range of 60°C. At this time, the number average molecular weight of the copolymer is adjusted to be 10,000 to QOOOOOO. If it is less than 10,000, the strength of the coating film will decrease, and if it is greater than 100,000, the viscosity of the resin will increase.

As the solvent in the copolymerization reaction and the esterification reaction described below, one or more of aliphatic alicyclic and aromatic hydrocarbons, halogenated hydrocarbons, ethers, esters, ketones, alcohols, etc. A mixture of is used. Examples of linear monoepoxy alkanes having 6 to 22 carbon atoms include epoxyhexane, epoxyheptane,
Epoxyoctane, epoxynonane, epoxydecane,
One or a mixture of two of epoxy undecane, epoxy dodecane, epoxy tetradecane, epoxy hexadecane, and epoxy octadecane can be used.

These linear monoepoxy alkanes are produced industrially by oxidizing α-olefins obtained by polymerization of ethylene, etc., or linear internal olefins obtained by dehydrogenating n-paraffins using peracids, etc. It is manufactured by epoxidizing with a chemical agent. Note that linear monoepoxy alkanes with carbon numbers of 5 or less cannot impart sufficient flexibility to the resin, and those with carbon numbers of 23 or more have too long side chains, resulting in poor gasoline resistance. .

Therefore, the carbon number range of the linear monoepoxy alkane suitable for balancing both flexibility and gasoline resistance is 6 to 22. Such a linear monoepoxy alkane is used in an amount necessary to esterify all or part of the side chain carboxyl groups, but even if the side chain carboxyl groups remain, the acid value of the resin is 20 mg KOH/y or less. It is preferable to have one.

When the resin acid value is higher than 20m9K0H/q, water resistance decreases and solubility in hydrocarbon solvents also deteriorates. The reaction between a side chain carboxyl group and a straight chain monoepoxy alkane is
The reaction is carried out in a solution in the presence of a catalyst at a temperature of 70 to 1800C, preferably 90 to 160C.

The catalysts used in the present invention include aliphatic and aromatic tertiary amines, quaternary ammonium salts, phosphines, phosphates, lithium salts, etc. -10% by weight, preferably 0.5-5% by weight. Among these catalysts, it is preferable to use tertiary amines and quaternary ammonium salts because they cause less coloring of the resin solution. Examples of tertiary amines include trimethylamine, triethylamine, tripropylamine, triallylamine, and triphenyl. Amin, N.N.
- Dimethylbenzylamine, tribenzylamine, pyridine, quinoline, α-picoline, β-picoline, etc. Quaternary ammonium salts include tetramethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, trimethylbenzylammonium chloride, Examples include triethylbenzylammonium chloride. Also by a method of copolymerizing acrylic acid hydroxyalkyl ester and/or methacrylic acid hydroxyalkyl ester obtained by the reaction of a linear monoepoxy alkane with acrylic acid and/or methacrylic acid with methyl methacrylate, styrene, etc. , a resin having the same composition as the resin obtained by the production method of the present invention can be obtained.

However, since such monomers have lower polymerization reactivity than acrylic acid and methacrylic acid, when copolymerized with methyl methacrylate, styrene, etc., they tend to be distributed in large amounts at the ends of the main chain of the copolymer. Therefore, in the resin obtained by this method, the distribution of long-chain alkyl groups having hydroxyl groups is skewed compared to the resin produced by the method of the present invention, resulting in a decrease in pigment dispersibility and flexibility. Be looked at. This resin can be used alone as a lacquer, but in some cases, a mixture of various resins may also be used.

These miscible resins include nitrocellulose,
Examples include cellulose resins such as cellulose acetate, cellulose propionate, and cellulose acetate butyrate, water-insoluble alkyd resins, and vinyl resins. In addition, commonly used plasticizers, pigments, and other additives for forming paints can also be used in conventional amounts according to known paint manufacturing methods.

The present invention will be explained in detail below with reference to Examples. All blended parts in the examples are shown in parts by weight. Example 1 Stirrer,
Put 65 parts of toluene and 65 parts of butyl acetate into a four-way flask equipped with a dropping load, nitrogen inlet, and reflux device, and add 11 parts of butyl acetate.
While maintaining the reflux temperature between 0 and 130°C, add methyl methacrylate, styrene, butyl acrylate, 1 acrylic acid, 1 2,2-azobisisobutyronitrile.
1 part of the mixed solution was added dropwise over 2 hours.

After the dropwise addition was completed, the reflux state was maintained and stirring was continued for 2 hours, followed by AOE-X24 (mixture of 1.2-epoxydodecane and 1.2-epoxytetradecane; trade name of Daicel Corporation) 3 (2). and 0.3 part of tetramethylammonium chloride were added thereto, and the mixture was heated under reflux while stirring for further 8 hours. The resulting resin solution has a non-volatile content of 50%,
The acid value was 2.6K0Hmg/y1 and the viscosity was P (25°C) using a Gardner viscometer. Example 2 As in Example 1, 65 parts of toluene and 65 parts of butyl acetate were placed in a reaction vessel, and while maintaining the temperature at reflux, methyl methacrylate 7(2), butyl acrylate, and acrylic acid were added.
30 parts of AOE-X24 and 0.3 part of tetramethylammonium chloride were added and reacted.

The obtained resin solution has a non-volatile content of 50% and an acid value of 1.7K0H.
The m9/V1 Gardner viscosity was W (25, C).
Example 3 In the same manner as in Example 1, 130 parts of toluene was placed in a reaction vessel, and while maintaining the reflux temperature at 100 to 120°C, methyl methacrylate, styrene, butyl acrylate, and acrylic were added. One part of acid and one part of 2,2-azobisisobutyronitrile were reacted, and 15 parts of 1,2-epoxyhexane and 0.6 part of NN-dimethylbenzylamine were added and reacted.

The obtained resin solution had a non-volatile content of 50% and an acid value of 2.5K0.
Hmg/y1 Gardner viscosity was O (25°C).
Example 4 In the same manner as in Example 1, 126 parts of xylene was placed in a reaction vessel, and while maintaining the reflux temperature at 120 to 140°C, methyl methacrylate, styrene (9) parts, butyl acrylate, and acrylic acid were added. 5 parts methacrylic acid and 2.2 parts
1 part of -azobisisobutyronitrile was reacted, and 26 parts of a linear internal epoxy alkane mixture having 11 to 14 carbon atoms (epoxy equivalent weight 205) and 1 part of tetramethylammonium chloride were further added and reacted.

The obtained resin solution has a non-volatile content of 50% and an acid value of 3.6K0H.
mg/y, and the Gardner viscosity was R(25, C).
Example 5 In the same manner as in Example 1, toluene and butyl acetate were placed in a reaction vessel, and while keeping the mixture at reflux temperature, methyl methacrylate, 34 parts of styrene, and ethyl acrylate were added to Osaka acrylic acid. 6 parts and 1 part of 2.2-azobisisobutyronitrile were reacted, and AOE-X68 (1.
A mixture of 2-epoxyhexadecane and 1.2-epoxyoctadecane (trade name of Daicel Corporation) and 0.4 part of tetramethylammonium chloride were added and reacted.

The obtained resin solution has a non-volatile content of 50% and an acid value of 3.1K0H.
m9/g, Gardner viscosity Q (25°C). Example 6 Same as Example 1, 62.5 parts of toluene, 6 parts of butyl acetate
2.5 parts of methyl methacrylate, styrene, ethyl acrylate, butyl acrylate, methacrylic acid, and 2.2-azo were added to a reaction vessel while maintaining the temperature at reflux. 1 part of bisisobutyronitrile was reacted, and further 25 parts of AOE-X24 and 0.3 parts of tetramethylammonium chloride were added and reacted.

The obtained resin solution has a non-volatile content of 50% and an acid value of 2.7K0H.
m9/y1 Gardner viscosity P4 (25°C). Example 7 Same as Example 1, 57.5 parts of toluene, 5 parts of butyl acetate
7.5 parts of methyl methacrylate, 4 parts of styrene, butyl acrylate, 8 parts of acrylic acid, and 1 part of 2.2-azobisisobutyronitrile were added to a reaction vessel while maintaining the temperature at reflux. After the reaction, 15 parts of AOE-X24 and 0.3 parts of tetramethylammonium chloride were added and reacted.

The obtained resin solution had a nonvolatile content of 50% and an acid value of 4.9K0.
Hm9/y1 Gardner viscosity T (25°C). Comparative Example 1 62.5 parts of toluene and 62.5 parts of butyl acetate were placed in a reaction vessel, and while keeping the temperature at reflux, 40 parts of methyl methacrylate, 3 (2) styrene, and 2 parts of butyl acrylate were added.
0 parts, 35 parts of n-dodecyl methacrylate, and 1 part of 2,2-azobisisobutyronitrile were added dropwise to react.

The resulting resin solution had a non-volatile content of 50% and a Gardner viscosity of 0.
(25 fat C). Comparative Example 2 In the same manner as in Example 1, 67 parts of toluene and 67 parts of butyl acetate were placed in a reaction vessel, and while maintaining the temperature at reflux, methyl methacrylate 4 (2), Styrene 3 Co., Ltd., Osaka butyl acrylate 2 (2) were added. ), 1 part of acrylic acid and 1 part of 2,2-azobisisobutyronitrile are reacted, and further Cardinal E (glycidyl ester of tertiary fatty acid; Shell Chemical (
Co., Ltd. (trade name)) and 0.34 parts of tetramethylammonium chloride were added and reacted.

The obtained resin solution had a non-volatile content of 50% and an acid value of 1.1K0.
Hmg/da, Gardner viscosity Q (25 hot. Comparative Example 3 a) Acrylic acid 1 (4) parts, AOEX 243 (4) parts, tetramethylammonium chloride 3 parts, hydroquinone 0.1 part, cellosolve acetate 3 (4) parts was placed in a reaction vessel and stirred at a temperature of 150 to 170°C for 8 hours to carry out an addition reaction between epoxy groups and carboxyl groups.

This reaction solution was distilled under reduced pressure to 50-54℃13-1
5 wu! Unreacted AOE-X24 was distilled off using LHg at 150-160°C/277!77! An adduct of acrylic acid and AOE-X24 was obtained with Hg. b Put toluene part and butyl acetate part D into a reaction vessel, and while keeping it at reflux temperature, add methyl methacrylate part, styrene 3(2),
A mixture of 20 parts of butyl acrylate, 0 part of the addition reaction product obtained in Comparative Example 3-a), and 1 part of 2,2-azobisisobutyronitrile was added dropwise to react.

The obtained resin solution had a non-volatile content of 50% and a Gardner viscosity of P.
(250C). Enamels were prepared using the resin solutions of the Examples and Comparative Examples, coated on a polished mild steel plate, force-dried at 80° C. for 30 minutes, and their coating performance was examined.

The results are shown in Table I. Table I Results of measurement of physical properties of coating film Note: a) Black second NC solution was prepared using nitrocellulose DN Pi (
20 parts of Daicel Corporation, 16 parts of methyl ethyl ketone,
A solution dissolved in a mixture of 64 parts of methyl isobutyl ketone was used.

Claims (1)

[Claims] 1 a Methyl methacrylate 20-96% by weight, styrene 0-76% by weight, total of both 60-96% by weight, b
A copolymer consisting of 4 to 20% by weight of acrylic acid and/or methacrylic acid, and 0 to 36% by weight of a monomer copolymerizable with these, has 6 to 6 carbon atoms in part or all of the side chain carboxyl groups. A method for producing a solvent-volatile paint resin, which comprises reacting one or a mixture of two or more of 22 linear monoepoxy alkanes in the presence of a catalyst.