KR100610457B1 - Core-shell resin composition for water paint having good elasticity and anti-pollution - Google Patents

Abstract

The present invention relates to a core-shell resin composition for water-based coatings having excellent fouling resistance and elasticity and a method for manufacturing the same, and more particularly, a core having a core having a crosslinked degree gradually increasing toward the outside and a shell grafted to the core. It relates to a shell resin composition and a preparation method thereof. As the resin composition of the present invention improves both elasticity and adhesiveness of paint, it has resistance to latent fine cracks generated after repairing aqueous building paint or new coating, and has excellent stain resistance and excellent performance to maintain a beautiful appearance. Has

Water-based paints, core-shells, grafts, preemulsions, stain resistance, elasticity

Description

Core-shell resin composition for water-based coatings having excellent stain resistance and elasticity and a method for preparing the same {Core-shell resin composition for water paint having good elasticity and anti-pollution}

The present invention relates to a core-shell resin composition for water-based coatings having excellent fouling resistance and elasticity and a method for manufacturing the same, and more particularly, a core having a core having a crosslinked degree gradually increasing toward the outside and a shell grafted to the core. It relates to a shell resin composition and a preparation method thereof.

In general, a resin composition using a core-shell has been used as an aqueous coating material for building materials. In the case of conventional water-based resins, in order to impart stain resistance and elasticity to the paint, generally, a polymer compound composed of a monomer having a low average glass transition temperature is used, or a polymer compound having a low glass transition temperature is used as a core and a shell is used. Part of the method has been used to improve the elasticity and stain resistance by using a high polymer compound having a high glass transition temperature.

In addition, when the glass transition temperature of the high molecular compound forming the shell layer is 10 ° C. or higher in order to improve adhesiveness and improve stain resistance, the minimum coating film formation temperature of the paint is increased. A large amount of coating film forming aids are required, and as the time passes, they are released from the inside of the coating film to the outside, so that the elastic modulus of the coating film is lowered, which makes it difficult to achieve the purpose of the original paint. In addition, when the polymer compound with low glass transition temperature is used to increase the elastic modulus of the paint, it is a problem of adhesion due to poor adhesion resistance, and the elongation to be possessed by the elastic paint is excellent. There is a disadvantage that cannot be coped. As such, when using such a resin in general, it is impossible to simultaneously satisfy pollution resistance, elasticity and restoring force.

For example, Japanese Patent Laid-Open No. 04-45169 discloses a polymer emulsion resin composed of a core and a multilayer shell, which improves elongation at low temperatures by varying the glass transition temperature of the core, the primary shell and the secondary shell polymer. In order to improve the stain resistance and improve the stain resistance, there are limitations in improving the elongation at low temperatures and the resilience of the paint.

In addition, the Republic of Korea Patent Publication No. 143196, for the non-polluting paint for the glass transition temperature of the inner layer constituting the core in the range of -10 ℃ to 10 ℃ and the surface layer of the shell forming the outside of the glass transition temperature of 15 ℃ to 50 ℃. Although resins have been described, the present invention improves the stain resistance of paints, and there is no mention of elongation and resilience in such non-polluting paint resins.

As described above, in the case of a general elastic paint resin, it is a common method to set the glass transition temperature of the polymer component constituting the composition to a temperature lower than room temperature in order to increase the elongation of the paint. It has a disadvantage in that the fouling resistance is severely reduced, and it is difficult to simultaneously satisfy the elongation and resilience of the resin. In addition, in the case of a polymer emulsion resin having a core having a low glass transition temperature and a shell having a glass transition temperature higher than room temperature, a film forming aid such as a plasticizer is used to increase the film formation at low temperatures due to the high minimum film forming temperature. It is difficult to maintain the long-term elastic modulus of the coating film and the restoring force is difficult to cope with the contraction and expansion of the coating film with temperature.

Therefore, the present inventors have studied and researched to solve the above problems, by using a resin composition composed of a crosslinked core and a shell grafted thereto, it is possible to solve the problems of the prior art and to prepare a resin composition having excellent both stain resistance and elasticity. The present invention has been completed based on this.

Therefore, the object of the present invention is to maintain the beautiful appearance of the building by repairing the micro-crack and excellent resistance to latent cracks during new coating, with excellent contamination resistance and elasticity, and the penetration of moisture into the interior of the building materials It is to provide a core-shell resin composition for water-based paints to minimize the durability of the building material.

In addition, another object of the present invention is to provide a method for producing a core-shell resin composition for water-based coatings excellent in both stain resistance and elasticity.

The core-shell resin composition for water-based coatings for achieving the object of the present invention, the core-shell resin composition for water-based coatings, the glass transition temperature of -50 ~ -30 ℃ and the average particle diameter of 0.03-0.07㎛ Seed having; A core having a glass transition temperature of −40 to 10 ° C. and an average particle diameter of 0.06-0.1 μm, and the degree of crosslinking gradually increasing toward the outside; And a shell having a glass transition temperature of −20 to 0 ° C. and an average particle diameter of 0.1-0.15 μm, wherein 10 to 50% by weight of the monomer introduced in the shell manufacturing step is grafted with the core.

In addition, the production method for achieving the other object of the present invention, in the production method of the core-shell resin composition for water-based paint, acrylic acid, methacrylic acid, 1 to 8 carbon atoms of 100 parts by weight of the resin solid content in the reactor 5-20 parts by weight of an unsaturated monomer selected from the group consisting of an acrylic acid alkyl ester having an alkyl group, a methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, an aromatic vinyl compound and a vinyl cyan compound, and 0.1 to 1.5 parts by weight of a crosslinking agent. , 0.05 to 1.0 parts by weight of grafting agent, 1.0 to 6.0 parts by weight of emulsifier, 0.5 to 2.0 parts by weight of initiator, and 40 to 60 parts by weight of ion-exchanged water at 60 to 80 ° C to react to a glass transition temperature of -50 to -30 ° C. And a first step of preparing a seed having an average particle diameter of 0.03-0.07 μm.

Group consisting of acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, an aromatic vinyl compound and a vinyl cyan compound based on 100 parts by weight of the resin solid content At least one unsaturated monomer selected from the group consisting of hydroxy alkyl acrylates and hydroxy alkyl methacrylates having from 5 to 10 parts by weight of at least one unsaturated monomer selected from C5 to C8 alkyl groups comprising at least one hydroxyl group After adding 2-4 weight part, 0.05-1.0 weight part of crosslinking agents, and 0.05-1.0 weight part of grafting agents to a 1st tank, and mixing, this mixture was continuously made with acrylic acid, methacrylic acid, and a C1-C8 alkyl group. Acrylic acid alkyl ester having, having an alkyl group having 1 to 4 carbon atoms 10 to 20 parts by weight of an unsaturated monomer, at least one selected from the group consisting of methacrylic acid alkyl esters, aromatic vinyl compounds and vinyl cyan compounds, 1.0 to 6.0 parts by weight of an emulsifier, 0.5 to 2.0 parts by weight of an initiator, and 10 to 20 ion-exchanged water. A pre-emulsion was prepared by supplying to the second tank to which parts were added, and 0.1 to 0.8 parts by weight of a reducing agent was added to the reactor, and then the pre-emulsion was continuously supplied and reacted at 40 to 60 ° C. A second step of preparing a core having a glass transition temperature of and an average particle diameter of 0.06-0.1 μm, wherein the degree of crosslinking is gradually increased toward the outside; And

At least one of acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, an aromatic vinyl compound, and a vinyl cyan compound, based on 100 parts by weight of the resin solid content 30 to 85 parts by weight of at least one unsaturated monomer selected from the group consisting of hydroxy alkyl acrylates and hydroxy alkyl methacrylates having an alkyl group having 5 to 8 carbon atoms including at least hydroxyl groups, 1.0 to 6.0 parts by weight of an emulsifier, and initiator 0.5 To 2.0 parts by weight and 15 to 25 parts by weight of ion-exchanged water are reacted at 60 to 80 ° C. to have a glass transition temperature of −20 to 0 ° C. and an average particle diameter of 0.1-0.15 μm, 10 to 50% by weight consists of the third step of making a shell grafted with the core.

Hereinafter, the present invention will be described in more detail.

As described above, the core-shell emulsion resin composition of the present invention can also be broadly divided into three parts: a crosslinked seed and a core and a shell grafted to the core.

As the concept used in the conventional method, the core-shell resin composition of the present invention uses a polymer compound having a low glass transition temperature as a seed and a core and a polymer compound having a high glass transition temperature. It is a feature of the present disclosure to provide a grafted shell.

In addition, the manufacturing method of the core-shell resin composition of the present invention can be largely divided into three steps.

First, acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, aromatic vinyl compound, and vinyl cyan, based on 100 parts by weight of the resin solids in the reactor 5 to 20 parts by weight of unsaturated monomer selected from the group consisting of compounds, 0.1 to 1.5 parts by weight of crosslinking agent, 0.05 to 1.0 parts by weight of grafting agent, 1.0 to 6.0 parts by weight of emulsifier, 0.5 to 2.0 parts by weight of initiator, and ion exchanged water A first step is prepared by reacting 40 to 60 parts by weight at 60 to 80 ° C. to produce a seed having a glass transition temperature of −50 to −30 ° C. and an average particle diameter of 0.03-0.07 μm.

Wherein the unsaturated monomer of the first step is at least one from the group consisting of butyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate, methyl methacrylate, acrylic acid, methacrylic acid, and 2-ethyl hexyl methacrylate If the amount is less than 5 parts by weight with respect to 100 parts by weight of the resin solid content, it is difficult to control the particle size and there is a problem of obtaining a resin unsuitable for the final physical properties, if exceeding 20 parts by weight reaction temperature, particle size control This is difficult and unsuitable for final physical properties.

In addition, the reaction temperature of the first step is preferably from 60 to 80 ℃, the reaction time is delayed if the reaction temperature is less than 60 ℃, it becomes difficult to control the reaction by the exothermic reaction if it exceeds 80 ℃, The seed has a preferred glass transition temperature of -50 to -30 ° C and an average particle diameter of 0.03-0.07 mu m.

In addition, the limiting factor of the average particle diameter affects the particle diameters of the cores and shells to be produced later, and this particle diameter affects elongation and restoring force, washing resistance, chemical resistance, etc., which the resin is intended for.

Secondly, in the step of preparing the core, acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, based on 100 parts by weight of the resin solids, Hydroxy alkyl acrylates and hydroxy alkyl methacrylates having from 5 to 10 parts by weight of unsaturated monomers selected from the group consisting of aromatic vinyl compounds and vinyl cyan compounds, alkyl groups having 5 to 8 carbon atoms including at least one hydroxyl group 2 to 4 parts by weight of at least one unsaturated monomer selected from the group consisting of 0.05 to 1.0 parts by weight of crosslinking agent, and 0.05 to 1.0 parts by weight of grafting agent are added to the first tank and mixed,

This mixture is continuously at least from the group consisting of acrylic acid, methacrylic acid, acrylic acid alkyl esters having alkyl groups of 1 to 8 carbon atoms, methacrylic acid alkyl esters having alkyl groups of 1 to 4 carbon atoms, aromatic vinyl compounds and vinyl cyan compounds A pre-emulsion was prepared by supplying a second tank to which 10 to 20 parts by weight of at least one selected unsaturated monomer, 1.0 to 6.0 parts by weight of emulsifier, 0.5 to 2.0 parts by weight of initiator, and 10 to 20 parts by weight of ion-exchanged water were added.

0.1 to 0.8 parts by weight of a reducing agent was added to the reactor, and the preemulsion was continuously supplied and reacted at 40 to 60 ° C., having a glass transition temperature of −40 to 10 ° C. and an average particle diameter of 0.06-0.1 μm, A core is produced in which the crosslinking degree and the graft efficiency gradually increase toward the outside.

Here, the unsaturated monomer of the second step is butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethyl hexyl methacrylate, styrene, α-methyl styrene At least one selected from the group consisting of acrylonitrile, and methacrylonitrile, the amount of the amount added to the first tank is preferably 5 to 10 parts by weight, but less than 5 parts by weight of the present invention There is a problem that the crosslinking degree and the graft efficiency is not gradually increased toward the outside, so that the final physical properties of the resin cannot be maintained, and when 10 parts by weight is exceeded, a problem of increasing the adhesiveness of the final resin occurs. In addition, the amount added to the second tank is preferably 10 to 20 parts by weight, but if less than 10 parts by weight, there is a problem that the restoring force of the final resin is lowered, and if it exceeds 20 parts by weight, the elongation of the final resin is reduced. .

In addition, the unsaturated monomer having at least one hydroxyl group in the second step is preferably at least one selected from the group consisting of 2-hydroxy ethyl methacrylate, 2-hydroxy propyl acrylate, and hydroxy propyl methacrylate. When the amount is more than 2 parts by weight, the adhesiveness of the resin is lowered. When the amount is more than 2 parts by weight, the viscosity of the resin increases and the paint is produced. Have difficulty.

In addition, the reaction temperature of the second step was to maximize the efficiency of the grafting agent using a low temperature reaction of 40 ~ 60 ℃ using a redox initiator system, the reaction time is delayed if the reaction temperature is less than 40 ℃ If it exceeds 60 ℃, the problem that the graft efficiency is lowered. The core thus manufactured is prepared by using the pre-emulsion as described above, and a power feeding method for adjusting the graft ratio with the shell is used, whereby the graft is formed at the surface portion of the core rather than inside the core. Adjusted to happen.

Third, acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, aromatic vinyl compound, vinyl cyan compound, 30 to 85 parts by weight of an unsaturated monomer selected from the group consisting of hydroxy alkyl acrylate and hydroxy alkyl methacrylate having an alkyl group having 5 to 8 carbon atoms including at least one hydroxyl group, 1.0 to 6.0 parts by weight of an emulsifier, 0.5 to 2.0 parts by weight of initiator, and 15 to 25 parts by weight of ion-exchanged water were reacted at 60 to 80 ° C. to have a glass transition temperature of −20 to 0 ° C. and an average particle diameter of 0.1-0.15 μm, which were added in the shell preparation step. 10 to 50% by weight of the monomer comprises a third step of making a shell grafted with the core.

The unsaturated monomer used in the third step is preferably butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethyl hexyl methacrylate, styrene, α- At least one selected from the group consisting of methyl styrene, acrylonitrile, methacrylonitrile, 2-hydroxy ethyl methacrylate, 2-hydroxy propyl acrylate, and hydroxy propyl methacrylate; Although 85 weight part is preferable, when it is less than 30 weight part, there exists a problem that the elongation of final resin falls, and when it exceeds 85 weight part, the adhesiveness of a final resin will increase and a restoring force will fall.

Moreover, as a crosslinking agent used by this invention, a conventional 1, 3- butanediol diacrylate, 1, 3- butanediol dimethacrylate, 1, 4- butanediol diacrylate, and 1, 4- butanediol dimethacrylate , At least one selected from the group consisting of 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, divinylbenzene, ethylene glycol diacrylate, and ethylene glycol dimethacrylate. The amount used is 0.1 to 1.5 parts by weight in the first step and 0.05 to 1.0 parts by weight in the second step. When the amount of the crosslinking agent used in each of the first and second steps is less than the amount of use described above, it is difficult to achieve a predetermined purpose because the resilience of the film is reduced and the adhesion is increased when forming the coating film, When used a lot, the surface of the coating film is not smooth when the coating film is formed, the tensile strength of the coating film is increased, but there is a problem that the tensile elongation is lowered.

In addition, as the graft agent used in the present invention, aryl methacrylate, triarylcyanurate, triaryl isocyanurate, glycidyl methacrylate, ethylene glycol dimethacrylate, and butylene glycol diacrylate At least one selected from the group consisting of, the amount is used in all the steps, 0.05 to 1.0 parts by weight, if less than 0.05 parts by weight of the graft of the shell in the shell manufacturing process of the third step, the adhesiveness of the coating film This increases and there is a problem that the restoring force of the coating film is lowered, if the amount exceeds 1.0 parts by weight, the graft amount of the shell is increased to increase the hardness of the coating film, but the tensile elongation is lowered, and the film is not easily formed.

As the polymerization initiator used in the present invention, an oil-soluble initiator and potassium consisting of hydrogen peroxide, diisopropylene hydroperoxide, cumene hydroperoxide, benzoyl peroxide, tertiary butyl hydroperoxide, or lauroyl peroxide It is selected from the group consisting of water-soluble initiators such as persulfate, ammonium persulfate, sodium persulfate, the amount of which is used is 0.5 to 2.0 parts by weight, if the amount is less than 0.5 parts by weight, the reaction time is delayed and the problem of increasing molecular weight It is difficult to obtain the resin to be produced in accordance with the present invention, and when it exceeds 2.0 parts by weight, the molecular weight of the resin to be obtained becomes small, resulting in a decrease in pigment adsorptivity during paint production, resulting in a decrease in elongation of the paint.

Moreover, as an emulsifier used for this invention, anions, such as sodium dodecyl sulfate, sodium dodecyl benzene sulfate, sodium oleic sulfate, potassium dodecyl sulfate, dioctyl sodium persuccinate, sodium stearate, potassium stearate, etc. System emulsifiers and polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene and polypropylene copolymers, and the like, and the amount thereof is preferably 1.0 to 6.0 parts by weight. If the amount is less than 1.0 part by weight, the particle diameter is difficult to control and there is a problem that agglomerated mass is generated. If the amount is more than 6.0 part by weight, the water resistance during the formation of the coating film of the final resin is deteriorated.

Examples of the reducing agent used in the present invention include sodium bisulfate, sodium pyrosulfate, anhydrous glucose, ethylene diamine tetra sodium acetate, sodium formaldehyde sulfoxate, tetra sodium pyrophosphate, and the amount of use thereof is 0.1 to 0.8. Parts by weight are used.

The reaction water used in the present invention uses ion-exchanged water, and the amount used is such that the weight ratio of water to the entire monomers used in the present invention is 1: 1 to 1: 1.5.

In addition, the graft efficiency of the shell of the third step is to form a film on the glass plate using an 8mm applicator, and then dried at room temperature for 3 days or more, and the compound 2g collected therein is put into 400 ml of THF solvent and stirred for 24 hours. Next, this solution is separated using an ultracentrifuge, and the separated solution is dried to measure graft efficiency using Equation 1 below.

As described above, the emulsion resin composition of the present invention is used in paints for construction, in particular for paints that require pollution resistance and elasticity, thereby increasing the resistance to repair painting of buildings and potential microcracks of new buildings To maintain the beautiful appearance of the building.

In addition, the water-soluble emulsion paint is prepared in the same manner as the general emulsion paint using the polymer compound resin of the present invention as a binder, and the raw materials selected for each purpose, for example, pigments, dispersants, fillers, wetting agents, thickeners, rheols It can be produced by combining a loin control agent, antifoaming agent, film forming aid, plasticizer, pH control agent and the like.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Example 1

First stage

2 liter reactor equipped with a stirrer, thermometer and condenser, ion exchanged water 316g, butyl acrylate 38g, arylmethacrylate 0.1g, hexanediol dimethacrylate 0.2g, Rodafax CO436 (sulfated ammonium salt of alkylphenyl ethoxylate 0.4 g of Rhodia Co., Ltd. was added thereto, and after heating to 80 ° C., when the temperature reached 80 ° C., 0.06 g of ammonium persulfate was added and maintained for about 40 minutes to prepare a seed emulsion polymer.

1.2 g of sodium bisulfate was added to the reactor as a reducing agent, 103 g of ion-exchanged water, 5.2 g of Rodafax CO436, 0.8 g of ammonium persulfate, 70 g of butyl acrylate, 3 g of acrylonitrile, and 2 g of methacrylic acid were added to the first tank of the pre-emulsion. After stirring, 50 g of butyl acrylate, 3 g of acrylonitrile, 5 g of methacrylic acid, 20 g of 2-hydroxyethyl acrylate, 0.3 g of hexane diol dimethacrylate, and 0.8 g of aryl methacrylate were added thereto, followed by stirring. After the pre-emulsion was prepared, a pump was installed so that the pre-emulsion of the second tank was introduced into the pre-emulsion first tank at a constant speed, and the pre-emulsion of the first tank was continuously introduced into the reactor for 3 hours, and the second The pump is operated so that the mixture of tanks enters the preemulsion first tank. After the addition of the pre-emulsion was maintained for about 1 hour 30 minutes. The reaction temperature was 60 ° C.

3rd step

150 g of ion-exchanged water, 10 g of Rodafax CO436, 3.3 g of ammonium persulfate, 350 g of butyl acrylate, 70 g of acrylonitrile, 40 g of styrene, 13 g of methacrylic acid, and 40 g of 2-hydroxyethyl acrylate were pre-emulsified in the reactor for 4 hours. And continuously maintained for about 2 hours, and the emulsion polymer having a particle diameter of 0.14 micrometers, a solid content of 52%, a viscosity of 359 cps (25 ° C., Brookfield viscometer), and a shell graft efficiency of 30% Got it.

Example 2

The reaction temperature of the second stage was 50 ° C., 1.2 g of tertiary butyl hydroperoxide as an initiator, 2.0 g of sodium formaldehyde sulfoxate and 0.02 g of ferrous sulfate (FeSO ₄ · 7H ₂ O) as a reducing agent. Except for using, the same procedure as in Example 1 was carried out to obtain an emulsion polymer having a particle diameter of 0.17 micrometers, a solids content of 51.4%, a viscosity of 320 cps, and a shell graft efficiency of 42%. .

Example 3

Example 2, except that 2.0 g of Rodafax CO436 and 6.0 g of Koremul NP20 (polyoxyethylene nonylphenyl ether, concentrated product) were used as the emulsifying agent in the second step, and 5.0 g of Rodafax CO436 and 8.0 g of NP20 were used in the third step. In the same manner as in Example 1, an emulsion polymer having a particle diameter of 0.16 micrometers, a solid content of 52%, a viscosity of about 339 cps, and a graft efficiency of the shell was 29.5% was obtained.

Example 4

The same procedure as in Example 2 was carried out except that butyl acrylate was replaced with 2-ethyl hexyl acrylate. As a result, the particle size was 0.14 micrometer, the solid content was 51.8%, and the viscosity was 370 cps. And an emulsion polymer having a shell graft efficiency of 31%.

Example 5

The same process as in Example 1 was carried out except that the content of aryl methacrylate used in the second tank of the second stage was 1.5 g. As a result, the particle diameter was 0.12 micrometer and the solid content was 52.5. %, An emulsion polymer having a viscosity of 339 cps and a graft efficiency of the shell of 41% was obtained.

Comparative Example 1

Into a reactor equipped with a stirrer, a thermometer and a condenser, 323 g of ion-exchanged water, 0.35 g of Rodafax CO436, 35 g of butyl acrylate, and 0.3 g of aryl methacrylate were added, and the temperature was raised to 80 ° C. and 0.4 g of ammonium persulfate was added thereto. After reacting for 40 minutes to prepare a seed, the second step was 175 g of ion-exchanged water, 6.6 g of Rodafax CO436, 0.8 g of ammonium persulfate, 336 g of butyl acrylate, 14 g of acrylonitrile, 1.5 g of methacrylic acid, and aryl methacrylate. The pre-emulsion consisting of 1.1 g was continuously added to the reactor for 3 hours and held for 1 hour 30 minutes. In the third step, a pre-emulsion consisting of 126 g of ion-exchanged water, 6.0 g of Rodafax CO436, 0.7 g of ammonium persulfate, 232 g of butyl acrylate, 77 g of acrylonitrile, 20 g of styrene, and 4.0 g of methacrylic acid was added to the reactor for 3 hours. After maintaining for 2 hours to obtain an emulsion polymer.

Comparative Example 2

The same process as in Comparative Example 1 was conducted except that no crosslinking agent and a graft agent were added.

Comparative Example 3

380 g of ion-exchanged water, 0.36 g of Rodafax CO436, and 35 g of butyl acrylate were added thereto, and the temperature was raised to 80 ° C., 0.4 g of ammonium persulfate was added thereto, and reacted for 40 minutes to obtain a seed emulsion polymer. The pre-emulsion consisting of 175 g of ion-exchanged water, 6 g of Rodafax CO436, 335 g of butyl acrylate, 2 g of methyl acrylic acid, and 0.8 g of ammonium persulfate was continuously metered in for about 3 hours, and then maintained for about 1 hour to maintain the core emulsion polymer. After obtaining 126 g of ion-exchanged water, 5 g of Rodafax CO436, 0.7 g of ammonium persulfate, 150 g of butyl acrylate, 50 g of methyl methacrylate, 50 g of styrene, 70 g of acrylonitrile and 5 g of methylacrylic acid were added for 3 hours. Was continuously added to the reactor to obtain a core-shell emulsion polymer having a glass transition temperature of 10 ° C.

Table 2 shows the tensile elongation and restoring resistance of the paint prepared by using the polymer emulsion polymer obtained in Examples and Comparative Examples as a binder and the paint formulation of Table 1 below.

Material used g Distilled water 3.5 Humectant 0.07 Dispersant 0.02 Antifoam  0.5 Ethylene glycol 3.2 White Pigment 15 Sieving pigment 17 Ethylene wax One Organic Hollow Filler 0.25 Plastic pigment 20 Polymer Emulsion Polymer 40 Solvent 2 antiseptic 0.2 Thickener  0.4

The prepared coating was formed on the silicone resin plate using a 20 micron applicator, and after 14 days of drying at room temperature, the adhesiveness of the coating was evaluated by a finger touch method, and the tensile elongation of the plastic of KSM-3000 was evaluated. The type 2 test piece of the tensile measurement method was measured at a crosshead speed of 50 mm / min using an instron tension tester by cutting the test piece using a dumbbell die. The restoring force was expressed as a ratio to the original length by measuring the reduced length after stopping the tester at a predetermined elongation (180%) after 1 day at room temperature.

The fouling resistance was measured by the contamination test method using carbon black of the coating film, and the cleaning resistance was measured by the method of KSM5000-3351.

Property item % Elongation dynamic stability(%) Pollution resistance Adhesiveness of coating Cycle resistance Example 1 210 92 Good

2000 Example 2 220 91 Good

2200 Example 3 198 87 Good

2500 Example 4 194 88 Good

2240 Example 5 187 93 Good

2210 Comparative Example 1 70 84 Good

2200 Comparative Example 2 190 30 Bad  × 1500 Comparative Example 3 50 10 Good

2200

* In Comparative Examples 1 and 3, the restoring force was measured using the test piece when the test piece was not broken at the highest elongation.

: 우수,

: 양호, × : 불량

: Great,

: Good, x: bad

As can be seen in the above Examples and Table 2, the polymer emulsion polymer of the present invention is not only excellent in elongation and resilience of the elastic paints compared to other resins, but also exhibits excellent stain resistance and wash resistance due to the low adhesiveness of the resin. Therefore, it does not expose the micro cracks found during repair painting of the building or the micro cracks generated after new painting to the outside, and has excellent performance to maintain the beautiful appearance of the building with excellent expansion and contraction of the coating due to temperature change.

In addition, it is possible to minimize the penetration of moisture into the building material to increase the durability of the building material.

Claims (6)

In the core-shell resin composition for water-based paint, Seeds having a glass transition temperature of −50 to −30 ° C. and an average particle diameter of 0.03-0.07 μm; A core having a glass transition temperature of −40 to 10 ° C. and an average particle diameter of 0.06-0.1 μm, and the degree of crosslinking gradually increasing toward the outside; And It has a glass transition temperature of −20 to 0 ° C. and an average particle diameter of 0.1-0.15 μm, and has an excellent fouling resistance and elasticity in which 10 to 50% by weight of the monomer introduced in the shell manufacturing step is made of the shell grafted with the core. Core-shell resin composition for paints. In the manufacturing method of the core-shell resin composition for water-based paint, With respect to 100 parts by weight of the resin solids in the reactor, acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, an aromatic vinyl compound and a vinyl cyan compound 5 to 20 parts by weight of at least one unsaturated monomer selected from the group consisting of, 0.1 to 1.5 parts by weight of crosslinking agent, 0.05 to 1.0 parts by weight of grafting agent, 1.0 to 6.0 parts by weight of emulsifier, 0.5 to 2.0 parts by weight of initiator, and 40 to ion exchanged water. Reacting 60 parts by weight at 60 to 80 ° C. to produce a seed having a glass transition temperature of −50 to −30 ° C. and an average particle diameter of 0.03-0.07 μm; Group consisting of acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, an aromatic vinyl compound and a vinyl cyan compound based on 100 parts by weight of the resin solid content At least one unsaturated monomer selected from the group consisting of hydroxy alkyl acrylates and hydroxy alkyl methacrylates having from 5 to 10 parts by weight of at least one unsaturated monomer selected from C5 to C8 alkyl groups comprising at least one hydroxyl group After adding 2-4 weight part, 0.05-1.0 weight part of crosslinking agents, and 0.05-1.0 weight part of grafting agents to a 1st tank, and mixing, this mixture was continuously made with acrylic acid, methacrylic acid, and a C1-C8 alkyl group. Acrylic acid alkyl ester having, having an alkyl group having 1 to 4 carbon atoms 10 to 20 parts by weight of an unsaturated monomer, at least one selected from the group consisting of methacrylic acid alkyl esters, aromatic vinyl compounds and vinyl cyan compounds, 1.0 to 6.0 parts by weight of an emulsifier, 0.5 to 2.0 parts by weight of an initiator, and 10 to 20 ion-exchanged water. A pre-emulsion was prepared by supplying to the second tank to which parts were added, and 0.1 to 0.8 parts by weight of a reducing agent was added to the reactor, and then the pre-emulsion was continuously supplied and reacted at 40 to 60 ° C. A second step of preparing a core having a glass transition temperature of and an average particle diameter of 0.06-0.1 μm, wherein the degree of crosslinking is gradually increased toward the outside; And At least one of acrylic acid, methacrylic acid, acrylic acid alkyl ester having an alkyl group having 1 to 8 carbon atoms, methacrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms, an aromatic vinyl compound, and a vinyl cyan compound, based on 100 parts by weight of the resin solid content 30 to 85 parts by weight of at least one unsaturated monomer selected from the group consisting of hydroxy alkyl acrylates and hydroxy alkyl methacrylates having an alkyl group having 5 to 8 carbon atoms including at least hydroxyl groups, 1.0 to 6.0 parts by weight of an emulsifier, and initiator 0.5 To 2.0 parts by weight and 15 to 25 parts by weight of ion-exchanged water are reacted at 60 to 80 ° C. to have a glass transition temperature of −20 to 0 ° C. and an average particle diameter of 0.1-0.15 μm, 10 to 50% by weight is characterized in that the third step to produce a shell grafted with the core A method for producing a core-shell resin composition for water-based coatings according to claim 1 having stain resistance and elasticity. The method of claim 2, wherein the unsaturated monomer of the first step consists of butyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate, methyl methacrylate, acrylic acid, methacrylic acid, and 2-ethyl hexyl methacrylate. Method for producing a core-shell resin composition for water-based coatings having excellent stain resistance and elasticity, characterized in that at least one selected from the group. The method of claim 2, wherein the unsaturated monomer of the second step is butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethyl hexyl methacrylate, styrene, A method for producing a core-shell resin composition for water-based coatings having excellent stain resistance and elasticity, characterized in that at least one selected from the group consisting of α-methyl styrene, acrylonitrile, and methacrylonitrile. The method of claim 2, wherein the unsaturated monomer having at least one hydroxyl group in the second step is at least one from the group consisting of 2-hydroxy ethyl methacrylate, 2-hydroxy propyl acrylate, and hydroxy propyl methacrylate. Method for producing a core-shell resin composition for water-based coatings having excellent stain resistance and elasticity, characterized in that selected. The method of claim 2, wherein the unsaturated monomer of the third step is butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethyl hexyl methacrylate, styrene, excellent at least one selected from the group consisting of α-methyl styrene, acrylonitrile, methacrylonitrile, 2-hydroxy ethyl methacrylate, 2-hydroxy propyl acrylate, and hydroxy propyl methacrylate A method for producing a core-shell resin composition for water-based coatings having stain resistance and elasticity.