KR101127873B1 - Flame retardant coating agent for foam resin and method for preparing the same, polystyrene foam comprising the same - Google Patents

Abstract

The present invention is to modify the inorganic flame retardant surface with a silane or a silane compound to adhere well between the EPS bead surface and the filler (filler) to increase the fusion between the beads during foam molding and to prevent the inorganic or inorganic flame retardant from deviating well from the EPS surface To increase the flame retardancy and moldability.
In addition, the present invention is to add a nano-sized colloidal silica particles to the filler to fill the micro-pores between the beads to form a compact structure during foam molding, the density is improved and the heat transfer can be hindered to increase the flame retardant effect and thermal insulation effect .

Description

Flame retardant coating composition for expanded polystyrene resin and method for manufacturing same, and flame retardant polystyrene foam comprising the same {FLAME RETARDANT COATING AGENT FOR FOAM RESIN AND METHOD FOR PREPARING THE SAME, POLYSTYRENE FOAM COMPRISING THE SAME}

The present invention relates to a flame-retardant coating composition for expanded polystyrene resin and a method for manufacturing the same, and to a flame-retardant polystyrene foam including the same, in particular, an environmentally-friendly organic-inorganic hybrid non-halogen flame-retardant coating agent for flame retarding the surface of the expanded polystyrene (EPS) particles It provides a composition, it is easy to fusion by chemical bonding during the bulk molding of the flame-retardant coating composition and the pre-expanded polystyrene particles, and also to extinguish toxic gas in the case of fire and to suppress the density of the expanded polystyrene particles It is to provide a flame-retardant polystyrene foam that can be improved to improve the thermal insulation efficiency.

In general, the foamed resin foam is lightweight and excellent in heat insulation, and is widely used in general construction and industry.

In particular, polystyrene foam (Expanded poly styrene, hereinafter referred to as 'EPS') is produced by adding a foaming gas such as pentane, butane to the polystyrene resin or copolymer resin prepared by polymerization from styrene monomer (styrene monomer) , EPS beads are 98% or more air and only 2-3% are polystyrene, so they have excellent buffering, sound absorption, light weight, heat insulation, formability, and are widely used as building insulation and packaging materials.

However, the polystyrene foam as described above is susceptible to heat, and in recent years, the use of the polystyrene foam has been limited due to the possibility of fatal damage due to the enormous flammability and toxic gas generation.

Therefore, researches for flame retardant are being actively conducted. As a method, a flame retardant is mixed with a foamed resin to prepare a foamed flame retardant resin, and a flame retardant is mixed with a raw material resin when the foamed resin is produced by an extrusion method. A method of extrusion foaming, a method of coating a flame retardant on the surface of the foamed resin foam, a method of injecting a flame retardant between the pores of the foamed resin foam, a method of coating a flame retardant to the foam beads and foam molding to produce a foam.

The method of injecting a flame retardant into a double EPS molded article has a very high flame retardancy, but has a long drying time and is difficult to process by hot wire, and the method of applying a flame retardant coating on the surface of the bead particle has high adhesion and formability by high pressure steam. Fall and the adhesive is harmful to the human body and the environment, and in the event of fire will emit halogen gas and volatile organic compounds (VOCs) has a disadvantage that is not environmentally friendly.

Therefore, a method of manufacturing a desired shape by coating a flame retardant on the surface of EPS beads (beads) molded with a size of 0.2 to 5 mm in diameter and then putting them in a molding mold and fusion to each other by high temperature and high pressure steam is most preferred. .

However, thermoplastic resins or thermosetting resins used in conventional EPS bead flame retardant coatings, isocyanate compounds used as adhesion aids, and halogen compounds as flame retardants release a large amount of VOCs (volatile organic compounds) and are rather toxic in fire. It has a disadvantage of harmful to the environment and the human body by generating a smoke, and metal hydroxide flame retardants or inorganic particles such as aluminum hydroxide and magnesium hydroxide mixed with an adhesive do not stick well to hydrophobic EPS and have a problem of poor moldability and flame retardancy. .

In addition, ceramic fine powders used as flame retardant aids, such as expanded graphite and calcium carbonate, have disadvantages such as inhibiting fusion between beads by steam, thereby degrading moldability, and leaving a powdery phase in the mold after molding.

Therefore, the present invention was devised to provide a new coating composition and method for improving environmental friendliness, manufacturing cost, and flame retardancy due to flame retardant coating. In the case of forming a flame retardant layer on the surface of a conventional EPS bead, the inorganic flame retardant particles are hydrophobic EPS. The present inventors modify the inorganic flame retardant surface with a silane or a silane compound so that it adheres well between the EPS bead surface and the fillers, thereby increasing the adhesion between the beads and forming the inorganic or inorganic flame retardant. It is possible to increase the flame retardancy and formability by preventing the separation from the EPS surface.

In addition, the present invention is to add a nano-sized colloidal silica particles to the filler to fill the micro-pores between the beads to form a compact structure during foam molding, the density is improved and the heat transfer can be hindered to increase the flame retardant effect and thermal insulation effect .

As described above, the present invention can modify the surface of the inorganic flame retardant (including metal hydroxide) which is difficult to adhere to the hydrophobic EPS bead by hydrolyzed silane or silane compound, thereby keeping the flame retardant evenly adhered to the EPS bead surface and maintaining strong adhesion. By doing so, the flame retardancy and moldability can be significantly improved.

In addition, the present invention, by adding nano-sized colloidal silica particles to the filling to be able to densely fill all the micro-pores between the beads to become a compact structure in the EPS foam molding, the density is improved and the heat transfer can be interrupted to maximize the thermal insulation effect Is a very useful invention

1 is a reference diagram for showing the drying and fusion process of a typical flame-retardant coated EPS beads.
Figure 2 is a schematic diagram for showing the bonding pattern between the EPS beads and the general flame retardant coating.
Figure 3 is a schematic diagram for showing the bonding pattern between the EPS beads and the flame retardant coating agent of the present invention.
4 is a photograph photographing the state of FIG.
5 is a diagram illustrating a bonding state between the EPS beads and the flame retardant coating agent of the present invention.
Figure 6 is an enlarged cross-sectional view of the EPS bulk formed after the flame-retardant coating according to the present invention.
Figure 7 is a photograph of a flame-retardant EPS foam molded by the present invention, A is a flame-retardant EPS foam prepared by Example 1, B is a flame-retardant EPS foam prepared by Example 2 ('ga' group insulation) .
8 is a cross-sectional photograph of a state in which a molded flame-retardant EPS foam is cut, (1) is a flame-retardant EPS foam prepared by a water glass filling method, (2) is a flame-retardant EPS foam prepared by a bead coating method, (3) is a flame-retardant EPS foam produced by the present invention.
9 is a photograph taken after the flame test on the molded flame-retardant EPS foam, (1) is a flame-retardant EPS foam prepared by the water glass filling method, (2) is a flame-retardant EPS foam prepared by the bead coating method, (3) is a flame-retardant EPS foam produced by the present invention.
10 to 12 is a quality test report of the flame-retardant EPS foam prepared by the present invention.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment for a flame retardant coating composition for expanded polystyrene resin according to the present invention, a method for producing the same, and a flame retardant polystyrene foam including the same.

Figure 3 is a schematic diagram for showing the bonding pattern between the EPS bead and the flame retardant coating agent of the present invention, Figure 4 is a photograph showing the state of Figure 3, Figure 5 is a diagram illustrating the bonding state between the EPS bead and the flame retardant coating agent of the present invention. 6 is an enlarged cross-sectional view of the EPS bulk molded after the flame-retardant coating according to the present invention, Figure 7 is a photograph of a flame-retardant EPS foam molded by the present invention, A is a flame-retardant EPS prepared by Example 1 Foam, B is a flame-retardant EPS foam prepared in Example 2, Figure 8 is a cross-sectional photograph of the molded flame-retardant EPS foam is cut, (1) is a flame-retardant EPS foam prepared by the water glass filling method , (2) is a flame-retardant EPS foam prepared by the bead coating method, (3) is a flame-retardant EPS foam prepared by the present invention, Figure 9 is a photograph taken after the flame test on the molded flame-retardant EPS foam, (1) is flame retardant EPS foam produced by water glass filling method, (2) bead nose And a flame-retardant EPS foam produced by the method (3) is a flame-retardant EPS foam produced according to the present invention, it Figures 10 to 12 is a quality check test report of the fire retardant EPS foam produced by the present invention.

As shown in the drawings, the flame retardant coating composition for the expanded polystyrene resin of the present invention is to modify the inorganic flame retardant surface with a silane or a silane compound so that the inorganic flame retardant particles easily adhere to the EPS bead surface in forming a flame retardant layer on the EPS bead surface. .

In this case, as the silane or silane compound modified on the surface of the inorganic flame retardant, a molecular bond structure of the hydrolyzed silane or silane compound described below is used.

At this time, there are three molecular arrangements that can be chemically combined with styrene of EPS, as structural formulas (1) to (3), and the central metal Si shares oxygen atoms and polymerizes as shown in structural formula (4). It is possible. At this time, in the structure of formula (4), the organic functional group may be bonded to one to six instead of OH site. In addition, as shown in Structural Formula (5), it may be combined with a silanol group (SiOH) to have a structure in which one end is closed with oxygen.

The present invention is a metal alkoxide represented by [M (OR) n] (M is a metal atom, OR is an alkoxy group such as ethoxy, methoxy, n is 1 to 4) in order to modify the properties of the silane and silane compound Co-hydrolysis may be carried out by addition, and the silane or silane compound of another kind may further be added.

The flame retardant coating composition for the expanded polystyrene resin of the present invention is as follows.

Inorganic flame retardant 20-50 wt%; Thickener 0.1-2 wt%; Water 5-40 wt%; Silane 0.1-10 wt%; 0.001-2 wt% of acid or alkaline catalyst; 0.5-40 wt% of colloidal silica; 20 to 60 wt% of inorganic fillers including flame retardant aids; 8-30 wt% of a thermoplastic or thermosetting resin; Defoamer or defoaming agent 0.1 ~ 1wt%;

Moreover, the manufacturing method of the flame-retardant coating composition for expanded polystyrene resin of this invention is as follows.

20 to 50 wt% of inorganic flame retardant and 0.1 to 2 wt% of thickener are added to 5 to 40 wt% of water and stirred to disperse; 0.1 to 10 wt% of silane and 0.001 to 2 wt% of acid or alkali catalyst in the solution Adding and stirring, adding 0.5 to 40 wt% of colloidal silica to the solution, and stirring, adding 20 to 60 wt% of a flame retardant aid and an inorganic filler to the solution, and stirring the thermoplastic resin or thermosetting material into the solution. 8 to 30 wt% of the resin is added to the stirring step and the solution comprises a step of adding 0.1 ~ 1wt% of the antifoaming agent or defoaming agent.

The reason why the components are mixed and stirred in each step is because the reaction for each component must be performed sequentially, and the stirring time may vary depending on the catalyst in a few minutes to several ten minutes.

As the inorganic flame retardant, metal hydroxide (aluminum hydroxide, magnesium hydroxide), antimony oxide, zinc borate, phosphorous oxide, tin compound, modified silicon, molybdenum compound, copper (II) or cobalt (II) or nickel Complex of (II), zinc silicate, hydroxyapatite, silica, alumina, zirconia, AlN, Si ₃ N ₄ , BN, sodium carbonate, potassium carbonate, ammonium phosphate, potassium hydrogen carbonate, potassium chloride, white earth, calcium carbonate, diatomaceous earth, bentonite Oxide, non-oxide-based ceramics such as zinc oxide, Mica (Mica), etc. are used, wherein the most preferred addition amount of the inorganic flame retardant used for synergistic flame retardant is 20wt% ~ 50wt%. This is because the flame retardant effect is insignificant in the case of 20wt% or less, and the fusion of the EPS beads is inhibited in the case of 50wt% or more.

As the thickener, mainly cellulose compounds (methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, acrylic fiber solution, etc.) are used. At this time, the thickener is used to suppress the precipitation of the filler, the most preferred amount is 0.1wt% ~ 2wt%. This is because when the viscosity is less than 0,1wt%, the thickening effect is insignificant, resulting in specific gravity separation of the coating liquid, and when it is 2wt% or more, the viscosity is too high and coating is impossible.

Water may be deionized water, tap water, distilled water, or the like, but deionized water is preferably used. At this time, the most preferable amount of water is 5wt% ~ 40wt%, because it is difficult to fully disperse the filler in the case of 5wt% or less, because the coating liquid is thinned at 40wt% or more relatively adversely affects various properties such as flame retardant effect.

Silane is a silane or silane compound having one or more organic functional groups, and may be represented by RxSi (OR ') y, (x + y = 4), R is an alkyl or aryl or organic functional group, and OR' is an alkoxy group, mainly methoxy (-OCH3), ethoxy (-OC2H5), acetoxy and isopropoxy. When the reaction between the silane and the catalyst generates a slight heat of 40 ℃ level at this time should be stirred until the heat is completely cooled. At this time, the most preferable addition amount of silane is 0.1wt% ~ 10wt%, which is less than 0.1wt%, the binding with inorganic matters is difficult to expect the effect of promoting adhesion with EPS, in the case of more than 10wt% hydrolysis after condensation polymerization This is because it easily gels through and impairs the storage stability of the coating solution.

Acids and alkalis are used as catalysts. Acids are acetic acid, formic acid, hydrochloric acid, phosphoric acid, nitric acid, or a mixture of these, dissolved in water to give hydrogen ions. Made to indicate acidity. In addition, alkali (Base) is mainly used ammonia water, amine compounds or mixtures thereof, which dissolves in water to give hydroxide ions and the pH of the solution to 7 or above to show alkalinity. At this time, the most preferable addition amount of the catalyst is 0.001wt% ~ 2wt%, which is less than 0.001wt% hydrolysis rate of the silane, and more than 2wt% hydrolysis of the silane is too fast to partially gel the solution and the shelf life of the solution This is because stability is impaired.

Colloidal silica is to improve the fusion, density and thermal insulation properties during EPS bulk molding. By filling the micro voids between the EPS beads, the colloidal silica becomes a compact structure during foam molding, and the density is improved. To increase. At this time, the most preferred amount of colloidal silica is 0.5 to 40 wt%, which is because 0.5 wt% or less can not be expected to increase the density and adhesion strength of the EPS bulk molded body, and in the case of 40 wt% or more, whitening or rather fusion after drying This is because it inhibits the heat wire workability of the molded body.

As the inorganic filler, the above inorganic flame retardant components may be used as they are.In the initial reaction, the inorganic flame retardant reacts with silane (the silanol group of the hydrolyzed silane and the oxygen covalent bond with the surface of the inorganic particle). Is very slow and hardly reacts, so the inorganic flame retardant components added after the reaction are simply used as inorganic fillers for the purpose of synergistic flame retardation and fire retardation. At this time, the most preferred amount of the inorganic filler including the flame retardant adjuvant is 20wt% ~ 60wt%, which is because the flame retardant effect is not sufficient in the case of 20wt% or less, rather it lowers the fusion if more than 60wt%.

In this case, the inorganic filler may further include a flame retardant aid such as expanded graphite. The expanded graphite expands tens to hundreds of times when the flame touches to form a soot insulation layer and suppresses heat transfer, thereby maximizing the flame retardant effect. Because. At this time, the flame retardant auxiliary agent is preferably occupied 10-30% by weight of the total ratio of the inorganic filler.

The thermoplastic resin or the thermosetting resin is added 8wt% ~ 30wt%, because the fusion is inferior to 8wt% or less, the flame retardancy is significantly reduced when more than 30wt%.

The defoaming agent is added 0.1wt% ~ 1wt%, because the degassing force is less when 0.1wt% or less, and when it is 1wt% or more it lowers the adhesive strength of the resin and the fusion level of the EPS bulk.

As described above, the flame-retardant EPS bulk prepared by the present invention can be confirmed that even when the expanded bead particles are closer to hexagon than the other controls, the fusion degree is excellent.

In addition, even though comparing the state after the flame test of the EPS bulk molded product, the control group A (flame retardant EPS foam manufactured by the water glass filling method) has excellent flame retardancy, but powder generation and toxic gas are severely generated during the flame test. (Flame retardant EPS foam prepared by the bead coating method) is the retardation is delayed for 2-3 seconds and the soot (soot) occurs severely, the present invention can be confirmed that there is no residual and little soot compared to other controls.

Even with reference to Figures 10 to 12, it was not possible to manufacture the 'ga' group insulation material by the bead method of the insulation standard of the Korean Industrial Standards, but the EPS foam developed by the present invention has a thermal conductivity of 0.029 ~ 0.030W / m? K, Absorption rate 0.27g / 100㎠, Density 25.8㎏ / ㎥ (Based on Bead Method No. 2), Compressive strength 13.4 ~ 14.7N / ㎠, Thermal conductivity 0.034W / m? K based on 'ga' group insulation materials It is easy to control the density according to the type of beads, and satisfies various standards such as compressive strength and water absorption, so that the present invention is inexpensive compared to extrusion insulation and hard uretan, and it is economical because there is little deformation due to shrinkage and expansion.

The present invention will be described in more detail by way of examples.

Example 1

Example 1 is to prepare a flame retardant coating composition for EPS bead method No. 4 or sandwich panel, 26wt% of inorganic hydroxide aluminum hydroxide and 30wt% water, 0.3wt% methyl cellulose as a thickener in a container together The mixture was stirred at 600 rpm for 10 minutes.

0.1 wt% of acetic acid and 2 wt% of GPTMS (3-Glycidoxypropyltrimethoxysilane) were added thereto, followed by stirring at 600 rpm for 1 hour at room temperature. Thereafter, 4.3 wt% of colloidal silica was added, and 13 wt% of expanded graphite, 8 wt% of calcium carbonate, and 1 wt% of sodium carbonate were added and stirred at 800 rpm for 20 minutes. After that, 10 wt% and 5 wt% of EVA (Ethylene Vinyl Acetate) and acrylic emulsion, respectively, were administered, and the mixture was stirred at 600 rpm for 10 minutes, followed by mineral oil containing a nonionic surfactant to remove bubbles. Was added 0.3wt% of the flame retardant coating agent for the second flame-retardant grade (as of November 2011) panel.

After mixing a certain amount of the finished coating agent in the mixer with EPS beads and drying, EPS bulk was produced and analyzed by general vacuum filling and EPS bulk molding method by steam, and the fusion and flame retardancy were excellent.

Example 2

Example 2 is to prepare a flame retardant coating agent (coating agent for 'ga' group insulation) to increase the EPS bead density and insulation effect, 42 wt% of inorganic hydroxide aluminum and 17wt% of water, as a thickener metal cellulose (Methyl cellulose ) 0.2 wt% were put together in a vessel and stirred at 600 rpm for 10 minutes.

0.1 wt% of acetic acid and 3.4 wt% of GPTMS (3-Glycidoxypropyltrimethoxysilane) were administered and stirred at 600 rpm at room temperature for 1 hour. Thereafter, 15 wt% of colloidal silica was added thereto, and 6 wt% of insoluble ammonium phosphate and 2 wt% of insoluble ammonium phosphate were added thereto, followed by stirring at 800 rpm for 20 minutes. Thereafter, 12 wt% and 2 wt% of EVA (Ethylene Vinyl Acetate), a thermoplastic resin, and melamine, a thermosetting resin, were administered, and the mixture was stirred at 600 rpm for 10 minutes, followed by mineral oil containing a nonionic surfactant to remove bubbles. Wt) 0.3wt% was added to complete the flame retardant coating agent for high density flame retardant insulation. The EPS bulk coated with this composition has excellent water resistance and satisfies the 'ga' group insulation in density and thermal conductivity.

After mixing a certain amount of the finished coating agent in the mixer with EPS beads and drying, EPS bulk was produced and analyzed by general vacuum filling and EPS bulk molding method by steam, and the fusion and flame retardancy were excellent.

Although the present invention having the configuration as described above has been described by a limited embodiment, the present invention is not limited by this and the technical spirit of the present invention and the following by those skilled in the art to which the present invention belongs. Various modifications and variations are possible within the scope of equivalents of the claims to be described.

1: EPS Bead
2: flame retardant coating layer
3: flame retardant coating layer shrunk by drying
4: Interface between EPS beads after fusion molding by flame retardant coating

Claims (7)

delete delete delete Inorganic flame retardant 20-50 wt%; Thickener 0.1-2 wt%; Water 5-40 wt%; Silane 0.1-10 wt%; 0.001-2 wt% of acid or alkaline catalyst; 0.5-40 wt% of colloidal silica; 20 to 60 wt% of inorganic fillers including flame retardant aids; 8-30 wt% of a thermoplastic or thermosetting resin; Antifoaming agent or defoaming agent 0.1 ~ 1wt%; Flame retardant coating composition for expanded polystyrene resin, characterized in that consisting of.
5. The flame retardant coating composition for expanded polystyrene resin according to claim 4, wherein expanded flame retardant is used as expanded graphite.
20 to 50 wt% of inorganic flame retardant and 0.1 to 2 wt% of thickener are added to 5 to 40 wt% of water and stirred to disperse; 0.1 to 10 wt% of silane and 0.001 to 2 wt% of acid or alkali catalyst in the solution Adding and stirring, adding 0.5 to 40 wt% of colloidal silica to the solution, stirring, and adding 20 to 60 wt% of an inorganic filler including a flame retardant adjuvant into the solution and stirring the thermoplastic resin in the solution. Or adding 8-30 wt% of a thermosetting resin and stirring, and adding 0.1 to 1 wt% of an antifoaming agent or a degassing agent to the solution and stirring the flame retardant coating composition for expanded polystyrene resin.
The flame-retardant polystyrene foam containing the flame-retardant coating composition for expanded polystyrene resins in any one of Claims 4-5.

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