KR20070114894A - Non-aqueous dispersion composition - Google Patents

Abstract

A non-aqueous dispersion coating composition is provided to avoid a need for the use of a significantly large amount of solvent and to ensure solubility in a low-odor low-toxic aliphatic hydrocarbon solvent, while not adversely affecting the physical properties. A non-aqueous dispersion coating composition comprises a stabilizer (SB-1) obtained by using mineral spirit and Kocosol-100 in a ratio of 8:2, and by introducing 0.6 wt% of t-butyl peroctoate as an initiator, and 6.6 wt% of n-butyl acrylate, 17 wt% of isobutyl acrylate, 10.5 wt% of 2-ethylhexyl acrylate, 14.4 wt% of styrene and 1 wt% of acrylic acid, as monomers. In a variant, trimethylolpropane triacrylate is used instead of n-butyl acrylate.

Description

Non-aqueous dispersion composition

The present invention relates to an eco-friendly coating composition using only an aliphatic hydrocarbon of low odor and low toxicity by painting on interior and exterior of various buildings and having excellent coating appearance and physical properties. It relates to a non-aqueous dispersion (NAD) coating composition used.

Base resins used in construction paints and industrial coating processes include acrylic resins, epoxy resins, and urethane resins. Among them, acrylic resin occupies most of the base resin of paint due to colorless transparency, colorability by dyes and pigments, excellent chemical resistance, weather resistance and oil resistance.

Polymerization of acrylic resins from acrylic monomers is possible in any polymerization process during bulk, suspension, emulsion, dispersion, and solution polymerization. However, in order to use for paint, solution polymerization, emulsion polymerization, dispersion polymerization, etc. are the most useful.

Organic solvents used for polymerization are still mainly based on aromatic solvents including bezene, toluene and xylene.

However, in recent years, its use is limited due to air pollution, environmental hygiene and thermal stability during storage.

One of the methods recently attracting attention among the production methods of environmentally friendly paints corresponding to these regulations is the production of polymers by dispersion polymerization.

Dispersion polymerization is divided into aqueous and non-aqueous, among which water has practical advantages.

Low fire hazards, non-toxicity, and price competitiveness in using, manufacturing, or using equipment.

At the same time, however, water systems have the disadvantage of forming a coating film in the actual process. Water has a latent heat of evaporation of 500 cal / g compared to the latent heat of organic solvent (<100 cal / g), which requires more heat to evaporate the solvent in forming the coating film.

In addition, depending on the surrounding environment, the evaporation of the water-based paint is difficult to control by being affected by variables such as relative humidity.

In practice, these drawbacks can be improved by adding water-soluble diluents that control the degree of evaporation of the water system, but their use is limited due to increased toxicity.

In addition, since the freezing point of water is high compared to various organic solvents, its use in cold weather is limited.

Therefore, considering the shortcomings of such aqueous systems, non-aqueous dispersion polymerization is a method that can compensate for the shortcomings of aqueous systems and cope with the toxicity of solution polymerization.

Non-aqueous dispersion (NAD) polymerization is similar to solution polymerization in that the monomer is dissolved in a solvent, but the polymerization is performed while forming a dispersed phase by a graft polymer that acts as a stabilizer due to phase separation when the polymer is produced. It is similar to emulsion polymerization in that it proceeds.

In general, the solvent type acrylic resin has a number average molecular weight of about 10,000 to 30,000 to satisfy the required physical properties, and paints using such resin have advantages of durability, adhesion and water resistance, chemical resistance, and quick drying. On the other hand, a large amount of solvent is required to obtain a coating composition having an appropriate viscosity.

In addition, it has a solubility in esters, ketones, and aromatic ydrocarbon solvents, which have a great adverse effect on the air environment and the human body, while it has a solubility in low-odor, low-toxic aliphatic hydrocarbon solvents. can not do it.

As one of means for solving the above problems, there is a method of lowering the molecular weight of the resin, but this cannot be a fundamental solution because it involves deterioration of the coating film properties.

The present invention has been made in view of this point, and an object thereof is to provide a composition that can solve the above problems without deteriorating the coating film properties.

NAD acrylic resins are high molecular weight polymers present in a dispersed state in a solvent, and have a higher solid content than a solution type resin having a similar molecular weight and viscosity.

This is because the viscosity of the dispersion is basically dependent on the volume ratio, not on the molecular weight of the polymer.

In addition, since the components soluble in the aliphatic hydrocarbon solvent surround the insoluble polymers, they have a higher molecular weight than the solution-type resin, but have a dissolving power in the aliphatic hydrocarbon.

Therefore, by applying NAD acrylic resin, it is possible to reduce the content of volatile components in the paint. By using low odor and low toxicity aritic hydrocarbon solvent, the working environment is improved and the activity is possible soon after painting, especially after indoor painting. It has the advantage of being.

In the present invention, by providing an environmentally friendly NAD resin composition having a particle size of 0.1 ~ 1㎛ using a low-toxic aliphatic hydrocarbon (Aliphatic hydrocarbon) solvent as the main solvent and high boiling point aromatics (Aromatic) to increase the dispersibility The purpose of the present invention is to provide a NAD composition having superior gloss and repaintability by increasing the solid content to 50% or more and significantly improving the pigment dispersibility and resin stability compared to the conventional solution-type acrylic resin by using the solvent as a solvent.

EMBODIMENT OF THE INVENTION Hereinafter, the stabilizer and NAD resin manufacturing process in this invention for achieving the objective of this invention are demonstrated.

[Table 1] NAD resin dispersed particle model

In the manufacture of stabilizers, NAD resin is a form in which polymerized resin is mainly dispersed by a resin which acts as a stabilizer in an aliphatic hydrocarbon solvent.

Therefore, the polymerization of the resin used as a stabilizer is of primary importance. The stabilizer is located at the interface between the acrylic resin and the solvent insoluble in the solvent, thereby achieving stabilization of the dispersed phase by steric repulsion.

Therefore, the resin used as a stabilizer should be made so that one side is compatible with the acrylic resin while the other side is compatible with the solvent.

Mineral spirit and kocosol-100 were prepared using an initiator (t-butylperoctoate) in a ratio of 8: 2 to 2: 8.

As a test apparatus, a four-necked flask equipped with a condenser and a dropping panel was used. After mixing the mixed monomer with the solvent, the temperature was raised, and an initiator (t-butylperoctoate) was added thereto to proceed with polymerization.

The monomer was added dropwise over a certain amount of time for a uniform reaction.

Once the stabilizer is made, it is used to synthesize NAD resins with monomers in a solvent.

The insoluble part of the stabilizer binds to the NAD resin particles, and the dissolved part binds to the solvent side, thereby producing particles as shown in Fig. 1.

A NAD resin was prepared by polymerization with an initiator in a polymerization reactor similar to that used for the synthesis of stabilizers using a stabilizer and monomer mixture.

If necessary, an intermediate intermediate monomer and an initiator were added dropwise over a period of time.

Macromolecules of NAD polymers include ethylenically unsaturated monomers and organic solvents.

Organic solvents used as the main dispersion medium in the manufacture of NAD resins are aliphatic hydrocarbon solvents such as pentane, heptane, hexane, octane, nonane, mineral spirit (V-1), Kocosol-100, and ethyl propio. Nate, 2-methylpentane, methyl propionate, isopentane and neopentane, selected from the group consisting of one or two or more, and as an acrylic monomer, methyl methacrylate, ethyl methacrylate, propyl methacrylate Isobutyl methacrylate, butyl isocyanate, propyl isocyanate, hexyl isocyanate, butyl isocyanate, butyl methacrylate, ethyl acrylate, styrene, acrylonitrile, acrylamide, vinyl chloride, vinyl acetate, vinyl propionate and vinyl toluene And AA-6 (methyl meta macromer) monomer having one reactive group selected from the group consisting of 40-80% by weight based on one or more total solids, and acrylic acid, methacrylic acid, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, normal (alkoxy methyl) acrylic Reactive selected from the group consisting of amide, normal (alkoxy methyl) methacrylamide, trimethylolpropanetriacrylate, aryl methacrylate, 1,6-hexanedioldiacrylate, diethylene glycol diacrylate and butanediol diacrylate One or more monomers having two or more groups may be mixed and used so as to be 0.5-20% by weight based on the total solids.

As the polymerization initiator, benzoyl peroxide, tertiary butyl benzoate, t-butyl peroctoate or 2,2'-azobisisobutylnitrile may be used singly or in combination of two or more kinds thereof.

(1) Stabilizer manufacturing process

Trimethylolpropanetriacrylate, butanediolacrylate, normal butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl acrylate, styrene and acrylic acid are mixed in advance (this mixture is called monomer mix), mineral spirit , Kocosol-100 and monomer mix is mixed to maintain a temperature of 80 ~ 100 ℃.

After the initiator was added, the reaction was maintained at 30 minutes for 1 hour, and then the monomer mix, Mineral sprit, Kocosol-100, and t-butylperoctoate were mixed and added dropwise at 2 to 3 hours at a uniform speed.

After completion of the dropwise addition of t-butyl peroctoate and mineral spirit, Kocosol-100 was added and the reaction was maintained for 2 to 5 hours.

[Table 2] Inputs for Stabilizer Manufacturing

[Table 3] Monomer Type and Compounding Amount in Monomer Mix Preparation

Table 4 Comparative Examples Test Results

As a result of synthesizing the stabilizer, many unreacted monomers remained when the viscosity was low, resulting in poor compatibility with the solvent, and when the viscosity was high, the monomers gelled.

(2) Preparation of NAD Resin

The stabilizer prepared by the above process and Mineral sprit, Kocosol-100 is mixed and heated to 80 ~ 100 ℃ methyl methacrylate, ethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, aryl Methacrylate, styrene, Mineral sprit, Kocosol-100, and initiators are added dropwise at a uniform rate after mixing.

After completion of the dropping, the reaction was maintained at 30 minutes for 1 hour, and then an additional initiator was added, and the reaction was maintained at 2 hours for 5 hours.

NAD resins Preparation Examples 1 to 7 were used as stabilizer SB-1, and were prepared by changing monomer type and amount, solvent composition ratio, and initiator.

[Table 5] Input amount in the manufacture of NAD resin (using Stabilizer SB-1)

NAD resin preparation Examples 8-14 used the stabilizer SB-3, and the type and amount of other solvents and monomers are the same as in Examples 1-7.

NAD resin preparation Examples 15-21 used the stabilizer SB-5, and the other solvents and monomer types and amounts are the same as in Examples 1-7.

[Table 6] Comparative Example Test Results of Each Example in Preparation of NAD Resin

As a result of the experiments for the reaction, it was found that the solids, the viscosity, and the weather resistance physical properties of the stabilizers using SB-1 and SB-3 having a viscosity of about 5,000 to 5,500 were good.

The mixing ratio of the solvent resulted in the particle size decreases as the amount of Kocosol-100 was added in the composition ratio of Mineral sprit and Kocosol-100, and the physical properties such as pigment dispersibility, gloss, and resin particle stability were obtained.

As monomers, 2-hydroxyl ethyl methacrylate, methyl methacrylate, ethyl acrylate, and styrene were mainly used, and the alkali resistance tended to be improved, and aryl methacrylate and 2-hydroxypropyl acrylate were replaced. In the experiments used, alkali resistance and resin particle stability tended to be lowered.

The present invention uses a high boiling point aromatic solvent as an auxiliary solvent and an acrylic monomer to improve the dispersibility and can be combined with various pigments. And excellent resin stability and eco-friendly, low toxicity, low odor coating composition compared to VOCs. Its gloss, appearance, and coating properties are superior to existing solvent type coating acrylic resin compositions. After painting, the environment is improved.

Claims (10)

In the manufacture of stabilizer SB-1, the composition ratio of Mineral sprit and Kocosol-100 is mainly used in a mixture of 8: 2, 0.6 wt% of t-butylperoctoate as an initiator, 6.6 wt% of normal butyl acrylate as a monomer, NAD coating composition using 17% by weight of isobutyl acrylate, 10.5% by weight of 2-ethylhexyl acrylate, 14.4% by weight of styrene, and 1% by weight of acrylic acid The method of claim 1, NAD coating composition, characterized in that the normal butyl acrylate is replaced by trimethylol propane triacrylate. The method of claim 1, NAD coating composition, characterized in that the composition ratio of the mineral sprit and Kocosol-100 is 2: 8. In the NAD Example-1, the composition ratio of Mineral sprit and Kocosol-100 is mainly used in a mixture of 8: 2, and 33.6% by weight of SB-1, 1.5% of 2-hydroxyethyl methacrylate and 10.5 of methyl methacrylate as stabilizers NAD paint composition mainly using 1% by weight, 16.8% by weight ethyl acrylate, 7.4% by weight styrene, and 0.7% by weight t-butylperoctoate as an initiator The method of claim 4, wherein NAD coating composition, characterized in that the initiator is benzoyl peroxide. The method of claim 4, wherein NAD coating composition, characterized in that the composition ratio of the mineral sprit and Kocosol-100 is 2: 8. The method of claim 4, wherein NAD coating composition, characterized in that the stabilizer is SB-3. The method of claim 4, wherein NAD coating composition, characterized in that the initiator is benzoyl peroxide and the stabilizer is SB-3. The method of claim 4, wherein NAD coating composition, characterized in that the stabilizer is SB-5. The method of claim 4, wherein NB coating composition, characterized in that the stabilizer is SB-5, the composition ratio of the Mineral sprit and Kocosol-100 is 2: 8.