KR102574627B1 - High thermostable silicone modified reactive urethane hot-melt adhesives and producing method of coating textile using the same - Google Patents

Abstract

The present invention relates to a high heat-resistant silicone-modified reactive urethane hot-melt adhesive and a method for manufacturing a coated fabric using the same, wherein the high heat-resistant silicone-modified reactive urethane hot-melt adhesive comprises: (a) 2 to 5% by weight of organically treated nanoclay; (b) preparing a homogenized nanoclay solution by mixing 1 to 2% by weight of a silane coupling agent to improve the dispersibility of nanoclay; Polydimethylsiloxane / nanoclay treated to disperse the nanoclay by reacting the mixed nanoclay solution with (c) 10 to 30% by weight of octamethylcyclotetrasiloxane and (d) 5 to 15% by weight of tetramethyldisiloxane preparing a mixture; Here, 5 to 15% by weight of (e) 2-propen-1-ol is slowly added to prepare an OH-terminated reactive polydimethylsiloxane/nanoclay mixture to improve heat resistance. step; (f) preparing a prepolymer by reacting the OH-terminated reactive polydimethylsiloxane/nanoclay mixture in a ratio of 15 to 30% by weight of aromatic isocyanate; In the prepolymer prepared above, (g) 15 to 25% by weight of a polyester polyol having a number average molecular weight in the range of 500 to 4,000, (h) 2 to 5% by weight of a fluororesin-containing diol for improving heat resistance, and (i) stable flame retardancy After reacting 5 to 12% by weight of a reactive flame retardant for imparting and (j) 1 to 3% by weight of a chain extender for adjusting initial adhesive strength and strength, (k) 8 to 15% by weight of an addition-type flame retardant for imparting flame retardancy It is prepared by mixing %.

Description

High heat resistance silicone modified reactive urethane hot melt adhesive and manufacturing method of coating fabric using the same

The present invention relates to a highly heat-resistant silicone-modified reactive urethane hot-melt adhesive and a method for manufacturing a coated fabric using the same, and more particularly, to synthesize a functional polydimethylsiloxane/nanoclay mixture by applying organically treated nanoclay, and silicone-modified using the same It relates to a highly heat-resistant silicone-modified reactive urethane hot-melt adhesive having better heat resistance and good adhesion by preparing a urethane adhesive and a coated fabric using the same.

In general, safety protective clothing corresponding to ultra-high temperature environments is largely classified into industrial and firefighting. Accordingly, industrial heat-dissipating clothing is used as a protective clothing worn by workers at industrial sites handling molten metals, and heat-resistant clothing for firefighting refers to non-combustible heat-resistant clothing that can access flames or high-temperature radiant heat.

Since the heat-resistant clothing for firefighting is used at a temperature of 280° C. or higher than industrial heat-resistant clothing requiring heat resistance of about 180° C., higher heat resistance is required. It is composed of an adhesive, and a product composed of an aramid nonwoven fabric and a deposited film can be applied with a general urethane adhesive having excellent flexibility and adhesive strength, but it is easily peeled off due to low heat resistance.

As described above, the most important task in firefighting heat clothing is to improve heat resistance, but as various physical properties of adhesive materials are required to be improved, in the case of textile adhesives or hot melts used in heat radiation clothing, unlike conventional construction or structural adhesives, activity and washing Flexibility and high adhesive performance are required for durability improvement, and since the hot-melt adhesive is melted by heat and applied, emission of volatile organic solvents is very low, and its use as an eco-friendly adhesive is increasing.

The hot melt adhesive is a solid material at room temperature, but when heated, it melts into a fluid state and has adhesive strength to an adherend. When the melted hot melt adhesive is cooled, it recovers to a solid form and exhibits cohesive force. The adhesive strength of these hot melt adhesives is influenced by the anchor effect that increases the adhesive strength by allowing the liquid adhesive to flow through holes or irregularities on the surface. It is used by melting at high temperature to have.

In order to meet the above demands, organic-inorganic hybrid resins combine organic components (organic molecules or low molecular weight polymers, etc.) and inorganic components to simultaneously improve the hardness, thermal stability and durability of inorganic materials as well as the flexibility and toughness of organic polymers. It is recognized as a material that can be obtained. For example, by filling organic adhesives with inorganic particles such as nanoclay, carbon black, and expanded graphite, it is possible to improve physical properties such as mechanical properties, heat resistance, and air barrier performance, and thus apply to various materials. this is being tried

In addition, the silicone resin used in the present invention is known to have excellent flexibility and excellent water resistance and heat or oxidation stability because its main chain is composed of -Si-O- bonds made of organic and inorganic compounds, and it is known to have excellent adhesion even when exposed to heat. In the case of nanoclay or fluororesin that can maintain performance for a long time and exhibits high heat resistance and flame retardancy, physical property improvement has been attempted through complexation with various organic materials.

As a prior art for improving the physical properties of such a hot melt adhesive, Korean Patent Publication No. 10-2008-0088628 contains a urethane prepolymer obtained by reacting a polyol (A) and a polyisocyanate (B), and the polyol (A) 40% by mass to 80% by mass of polycarbonate polyol (a1), 5% by mass to 40% by mass of polytetramethylene glycol (a2), and an aliphatic polycarboxylic acid and an aromatic polycarboxylic acid with respect to the total amount of polyol (A) A moisture-curable polyurethane hot-melt adhesive containing 5% by mass to 40% by mass of a polyester polyol (a3) obtained by reacting polycarboxylic acid with a polyether polyol obtained by adding alkylene oxide to bisphenol A, and a laminated sheet using the same It is said that this adhesive can maintain excellent adhesive strength even after repeated washing under harsh washing conditions without impairing the soft feel of the laminated sheet.

In addition, in Patent Publication No. 10-2011-0022764, acrylic resin, polyurethane resin, polyester resin, toluene diisocyanate trimer (TDI Trimer), cyclohexylmethane diisocyanate (Cyclohexylmethane diisocyanate, H ₁₂ MDI ), toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), hexamethylene diisocyanate (HMDI) and polypropylene glycol (PPG) by mixing to prepare a first mixture step (step 1); mixing the first mixture with a surfactant to form a second mixture (step 2); And a method for producing an eco-friendly adhesive composition comprising the step (step 3) of preparing an eco-friendly adhesive composition by stirring the second mixture, which has excellent adhesive strength, does not cause yellowing, and cures quickly. It has the advantage that it does not contain heavy metals or volatile organic compounds (VOCs).

In addition, the moisture-curing reactive polyurethane hot-melt adhesive disclosed in Patent No. 10-1370442 contains 70 to 80% by weight of a mixture of polyether polyol and polyester polyol, 15 to 28% by weight of diisocyanate, and 0.5 to 20% by weight of chain extender. 5 to 10 parts by weight of an acrylic resin, 2 to 10 parts by weight of a thermoplastic polyurethane resin and 10 to 20 parts by weight of a tackifying resin based on 100 parts by weight of a polyurethane prepolymer containing 1.5% by weight and 0.05 to 0.2% by weight of a coupling agent. It exhibits an adhesive strength of 50 kf/20 mm or more at 20 ° C and an adhesive strength of 10 kf / 20 mm or more at 120 ° C, and has a melt viscosity of 30,000 to 60,000 cps at 120 ° C. It is said to be possible.

In addition, the present applicant, through Patent No. 10-1709909, demonstrates adhesive force and structural strength by using chemical crosslinking of isocyanurate produced as a trimer of diisocyanate, and at the same time increases the degree of curing to increase the thermal stability and chemical properties of the adhesive itself. It has excellent stability and can improve heat resistance and weather resistance. It is a 100% solid eco-friendly polyurethane adhesive that does not use solvents. It adheres to textile materials by thermal melting without a drying process in which solvents are volatilized. A reactive urethane hot melt adhesive having good physical properties such as adhesive strength and peel strength, soft touch and excellent heat resistance has been developed.

On the other hand, in the present invention, a silicone hybrid urethane adhesive having good compatibility was developed by prepolymerizing polydimethylsiloxane treated to disperse silane-treated nanoclay well. A silicon-modified reactive urethane hot-melt adhesive having good peel strength, excellent heat resistance and soft touch when attached to a fiber fabric by imparting flame retardancy and a method for manufacturing a coated fabric using the same were completed.

Republic of Korea Patent Publication No. 10-2008-0088628 (published on October 02, 2008) Republic of Korea Patent Publication No. 10-2011-0022764 (published on March 8, 2011) Republic of Korea Patent Registration No. 10-1370442 (Announcement date March 10, 2014) Korean Registered Patent Publication No. 10-1709909 (Date of Publication: February 24, 2017)

An object of the present invention is to prepolymerize polydimethylsiloxane treated so that silane-treated nanoclay is well dispersed and change the chemical composition and length of the soft segment of a silicone hybrid urethane adhesive having good compatibility, thereby improving physical properties such as mechanical strength It is to provide a highly heat-resistant silicone-modified reactive urethane hot-melt adhesive having good peel strength, excellent heat resistance, and soft touch even at a high temperature of 280 ° C. or higher when adhered to a textile fabric while maintaining and a method for manufacturing a coated fabric using the same.

The highly heat-resistant silicone-modified reactive urethane hot-melt adhesive according to the present invention contains (a) 2 to 5% by weight of organically treated nanoclay and (b) 1 to 2% by weight of a silane coupling agent for improving the dispersibility of the nanoclay. Preparing a homogenized nanoclay solution by mixing; Polydimethylsiloxane / nanoclay treated to disperse the nanoclay by reacting the mixed nanoclay solution with (c) 10 to 30% by weight of octamethylcyclotetrasiloxane and (d) 5 to 15% by weight of tetramethyldisiloxane synthesizing the mixture; Here, 5 to 15% by weight of (e) 2-propen-1-ol is slowly added to prepare an OH-terminated reactive polydimethylsiloxane/nanoclay mixture to improve heat resistance. step; (f) preparing a prepolymer by reacting the OH-terminated reactive polydimethylsiloxane/nanoclay mixture in a ratio of 15 to 30% by weight of aromatic isocyanate; In the prepolymer prepared above, (g) 15 to 25% by weight of a polyester polyol having a number average molecular weight in the range of 500 to 4,000, (h) 2 to 5% by weight of a fluororesin-containing diol for improving heat resistance, and (i) stable flame retardancy After reacting 5 to 12% by weight of a reactive flame retardant for imparting and (j) 1 to 3% by weight of a chain extender for adjusting initial adhesive strength and strength, (k) 8 to 15% by weight of an addition-type flame retardant for imparting flame retardancy It is characterized in that it is prepared by mixing %.

According to a preferred embodiment of the present invention, the organically treated nanoclay (a) has at least one organic selected from methyl, bis hydroxyethyl, and octadecyl ammonium on the surface of the particle. As inorganic particles with an average size of 5 to 30 microns (㎛) including functional groups, the polydimethylsiloxane/nanoclay mixture has a number average molecular weight in the range of 1,000 to 2,000, and the NCO% of the prepolymer is 10 to 15% It is characterized by being

And the manufacturing method of the coated fabric according to the present invention, the high heat resistance silicone modified reactive urethane hot melt adhesive is melted at a temperature of 80 ~ 120 ℃ and applied to the fiber fabric in an amount of 5 ~ 50g / ㎡, then the temperature 30 ~ 50 ℃ , It is made by aging for 12 to 48 hours under the condition of 70 to 100% relative humidity. 320 ℃, characterized in that the peel strength of 2 ~ 12N / 5cm.

The highly heat-resistant silicone-modified reactive urethane adhesive of the present invention applies organically treated nanoclay, silicone, and fluororesin-containing diol to provide excellent heat resistance, and exhibits strong adhesive strength and structural strength by increasing the degree of curing based on processability and flexibility. , Therefore, through the application of a reactive flame retardant, the heat stability and flame retardancy of the adhesive itself are excellent, and the heat resistance and weather resistance are improved.

In addition, the reactive urethane hot-melt adhesive of the present invention is a 100% solid eco-friendly polyurethane adhesive that does not use a solvent, and is bonded to a fiber material by thermal melting and has physical properties such as adhesive strength and peel strength without a drying process in which the solvent is volatilized. It has the advantage of being able to manufacture a coated fabric having good processability, soft touch and excellent heat resistance.

Hereinafter, a method for manufacturing a highly heat-resistant silicone-modified reactive urethane hot-melt adhesive and a coated fabric using the same according to the present invention will be described, which can be easily performed by a person skilled in the art to which the present invention belongs It is intended to illustrate to an extent, but does not mean that the technical spirit and scope of the present invention is thereby limited.

In general, polyurethane resin is a resin produced based on a urethane bond formed by the reaction of an isocyanate group (-NCO) and a hydroxyl group (-OH) in a polymer, and its raw materials are polyol, isocyanate, chain extender, etc. It is usually prepared by solution polymerization by adding various solvents. Accordingly, polyurethane resin has excellent film strength and adhesive strength, so it is possible to manufacture a thin coating film, and the elasticity of the coating film is rich, so it is soft to the touch and can be manufactured as a porous film, giving moisture permeability and breathability. In addition, it has excellent cold resistance, and since it is processed without using plasticizers, there are few workability problems caused by plasticizers.

However, conventional reactive urethane adhesives have excellent adhesiveness and processability using chemical and physical binding forces, but it is difficult to impart heat resistance of 270 ° C. or higher due to physicochemical limitations of the urethane chain.

Accordingly, inorganic materials such as general silicone adhesives or nanoclays having excellent heat resistance are used to develop materials with high heat resistance, but they are easily peeled off due to weak adhesive strength compared to excellent heat resistance/flame retardancy. In addition, urethane, silicone, and nanoclay are materials that are not compatible with each other, so when simply mixed and applied, phase separation occurs or gelation occurs.

Therefore, in a system including urethane, silicone, and inorganic particles (nanoclay), the dispersion of inorganic particles, which are reinforcing components, plays an important role in the physical properties of the final composite material. In addition, agglomeration of inorganic particles requires a much excessive reinforcing material, causing disadvantageous phenomena such as increase in viscosity and density. As a means to solve this problem, it is possible to apply a method of pre-treating inorganic particles with silane or the like to increase dispersibility.

In order to solve the above problems, the high heat resistance silicone modified reactive urethane hot melt adhesive of the present invention includes (a) 2 to 5% by weight of organically treated nanoclay and (b) a silane couple for improving the dispersibility of the nanoclay Preparing a homogenized nanoclay solution by mixing 1 to 2% by weight of ring agent; Polydimethylsiloxane / nanoclay treated to disperse the nanoclay by reacting the mixed nanoclay solution with (c) 10 to 30% by weight of octamethylcyclotetrasiloxane and (d) 5 to 15% by weight of tetramethyldisiloxane preparing a mixture; Here, 5 to 15% by weight of (e) 2-propen-1-ol is slowly added to prepare an OH-terminated reactive polydimethylsiloxane/nanoclay mixture to improve heat resistance. step; (f) preparing a prepolymer by reacting the OH-terminated reactive polydimethylsiloxane/nanoclay mixture in a ratio of 15 to 30% by weight of aromatic isocyanate; In the prepolymer prepared above, (g) 15 to 25% by weight of a polyester polyol having a number average molecular weight in the range of 500 to 4,000, (h) 2 to 5% by weight of a fluororesin-containing diol for improving heat resistance, and (i) stable flame retardancy After reacting 5 to 12% by weight of a reactive flame retardant for imparting and (j) 1 to 3% by weight of a chain extender for adjusting initial adhesive strength and strength, (k) 8 to 15% by weight of an addition-type flame retardant for imparting flame retardancy It is prepared by mixing %.

First, the organically treated nanoclay (a) used in the present invention is nanoparticles of layered mineral silicates having a nano size (less than 100 nm) in a particle state, and is generally smectite having a layered structure ( smectite)-based clay has a layer structure in which Si tetrahedron and Al octahedron form a three-layer (Si-Al-Si) structure in a ratio of 2:1. Among them, montmorillonite (MMT) is the most commonly used as it is highly swellable in water and has the best dispersibility. .

The nanoclay is widely used as an additive for polymer nanocomposites due to its high aspect ratio, incombustibility, and nanoscale size, and the organic treatment process facilitates the penetration of the polymer by inserting a low molecular weight organic modifier into the layered structure of the nanoclay. It can be said that it is a process of

The organic treated nanoclay (a) forms uniform particles or aggregates of a certain size by imparting organic functional groups to the surface of the particles, thereby improving dispersibility and improving the water resistance and tensile strength of the adhesive. It was confirmed that the nanoclay (a) preferably contains at least one organic functional group selected from methyl, bis hydroxyethyl, and octadecyl ammonium on the surface of the particle, As a result, it was confirmed that inorganic particles having an average size of 5 to 30 microns (㎛) are uniformly formed, thereby maximizing the mechanical properties of the adhesive, heat resistance, and flame retardancy (the nanoclay (a) is commercially available 1.44P, 1.24TL, 1.34TCN, etc.).

In addition, the modification to improve the dispersibility of the nanoclay (a) is a step of preparing a homogenized nanoclay solution by mixing 1 to 2% by weight of a silane coupling agent (b) based on the total weight of the adhesive As the silane coupling agent (b), APTES (3-Aminopropyl triethoxysilane), MPS (Methacryloxy propyltrimethoxysilane), GPS (Glycidoxy propyl trimethoxysilane), MCPS (Mercaptopropyl trimethoxysilane), etc. can be used, preferably one side of the chain APTES (3-Aminopropyl triethyoxysilane), which can increase heat resistance and mechanical strength by applying a silane group to the end group and introducing silicate nanoclay to the resulting functional group, is most suitable.

Through this, it is possible to further improve physical properties by strengthening the physical properties of the organically treated nanoclay (a) itself and crosslinking through hydrolysis-condensation between terminal silane coupling agents during the dispersion process.

The nanoclay (a) and the silane coupling agent (b) are first homogenized before being used in the reaction using a homogenizer, and then a well-mixed nanoclay solution (2 to 5% by weight of nanoclay + silane couple 1 to 2% by weight of ringing agent) is introduced and reacted, and the manufacturing step of reactive polydimethylsiloxane to which nanoclay (a) is applied is as follows.

In the present invention, 10 to 30% by weight of octamethyl cyclotetrasiloxane (c), 5 to 15% by weight of tetramethyl disiloxane (d) in a reactor under nitrogen supply, 3 to 7 After mixing the nanoclay solution by weight% in a stirrer, triflic acid (Trific acid, trifluoromethanesulfonic acid, TFMS, TFSA) is injected and reacted to obtain polydimethylsiloxane/polydimethylsiloxane having a number average molecular weight in the range of 1,000 to 2,000. Synthesize the nanoclay mixture.

Here, 0.05 to 0.1% by weight of a metal-vinylsilane complex catalyst was added, followed by 5 to 15% by weight of 2-propen-1-ol (2-propen-1-ol) ( e) was added slowly, reacted at a temperature of 90 to 100 ° C for 2 to 6 hours, removed foreign substances, and dried in a vacuum to prepare a reactive polydimethylsiloxane / nanoclay mixture of 23 to 67% by weight for improved heat resistance do.

The OH-terminated reactive polydimethylsiloxane/nanoclay mixture prepared as described above is reacted with 15 to 30% by weight of aromatic isocyanate (f) at a temperature of 80 to 90 ° C. for 2 hours to prepare a prepolymer. Isocyanate (f) may be selected and used from the group consisting of diphenylmethane diisocyanate (MDI), polycarbodiimide-modified diphenylmethane diisocyanate (modified MDI), or mixtures thereof, and in particular, has relatively excellent heat resistance and adhesive strength. It is most advantageous in terms of reactivity to use MDI with good MDI.

The prepolymer prepared therefrom is reacted so that the NCO% is in the range of 10 to 15% to obtain an NCO-terminated silicon nanoclay hybrid prepolymer. If the OH-terminated reactive polydimethylsiloxane/nanoclay mixture content is When added less than 23% by weight, the heat resistance is lowered, and when it exceeds 67% by weight, it was confirmed that the content of silicon increases, resulting in a tendency for adhesiveness and mechanical strength to decrease.

Next, an aromatic polyester polyol, a fluororesin-containing diol, a reactive flame retardant, a chain extender, and an additive type flame retardant were applied to the silicone nanoclay hybrid prepolymer for the preparation of the urethane adhesive having excellent heat resistance and good compatibility of the present invention. Based on the total weight, 15 to 25% by weight of a polyester polyol (g) in the range of 500 to 4,000 in number average molecular weight, 2 to 5% by weight of a fluororesin-containing diol (h) for improving heat resistance, and stable flame retardancy After reacting 5 to 12% by weight of a reactive flame retardant (i) for initial adhesion and 1 to 3% by weight of a chain extender (j) for adjusting strength, 8 to 15% by weight for imparting flame retardancy A highly heat-resistant silicone-modified reactive urethane hot-melt adhesive is prepared by mixing the additive flame retardant (k).

The aromatic polyester polyol (g) includes 5 to 10% by weight of polyester polyol having a number average molecular weight of 500 to 1500 and polyester having a number average molecular weight of 2,500 to 4,000 based on the total weight of the adhesive in consideration of characteristics such as heat resistance and adhesive strength. It is more suitable to use a mixture of 10 to 15% by weight of polyol to exhibit strong adhesive strength and good fluidity, and outside the above range, viscosity, feel, and adhesive strength of the resin itself are deteriorated.

On the other hand, general additives for imparting heat resistance and mechanical properties may cause migration after use and have problems in that the additives escape when used for a long time, whereas the fluororesin-containing diol (h) used in the present invention has a weight It is effective in improving heat resistance by containing 2 to 5% by weight of something having an average molecular weight of 1,000 to 2,000, and the fluororesin-containing diol (h) and the reactive flame retardant (i) are compounds having an OH functional group attached in the form of copolymerization during urethane synthesis. By doing so, it is possible to impart physical properties without adding additional additives later, and it has a characteristic that the physical properties are maintained even when used for a long time. In addition, if the content of the fluororesin-containing diol is less than 2% by weight, heat resistance may be weak and the copolymerization effect may be insufficient. There are concerns.

The reactive flame retardant (i) for imparting stable flame retardancy together with the fluororesin-containing diol (h) for improving heat resistance is diethyl N, N-bis (2-hydroxy having a number average molecular weight of 250 to 500 as shown in Formula 1 below) Ethyl) aminomethyl phosphonate or tetrabromophthalate diol-type reactive flame retardants such as Formula 2 below is used in an amount of 5 to 12% by weight based on the total weight of the adhesive to improve the reactivity with the polyol and the adhesive properties. It is preferable when considering physical properties.

[Formula 1]

[Formula 2]

In addition, the chain extender (j) for adjusting the initial adhesion and strength is usually one or more polyols selected from monoethylene glycol, 1,3-propanediol, 1,4-butanediol, and 1,6-hexanediol. When reacted using an appropriate ratio, the resin properties required in the present invention can be obtained, but it is best to use 1,6-hexanediol within 1 to 3% by weight to control the initial strength of the hot melt adhesive and the crystallinity at low temperatures. desirable. At this time, the NCO% in the final composition after the reaction is preferably prepared in the range of 2 to 5% for stable curing.

In addition, in the present invention, additive-type flame retardants commercially sold can be used to impart more improved flame retardancy, but when the amount of the conventional additive-type flame retardant exceeds 20% by weight, a blooming phenomenon occurs on the surface and the adhesive strength Since the deterioration is confirmed, in the present invention, the additive type flame retardant (k) was used within 8 to 15% by weight based on the total weight of the adhesive, and therefore, the insufficient flame retardancy was 5 to 12% by weight of the reactive flame retardant (i). As the additive-type flame retardant used in the present invention, aluminum hydroxide (Al(OH) ₃ ), ATH having a purity of 99.8% or more and an average particle diameter of about 8 μm is added in the final stage of the reaction to improve flowability and flame retardancy.

And the manufacturing method of the coated fabric of the present invention is to melt the high heat resistance silicone modified reactive urethane hot melt adhesive at a temperature of 80 ~ 120 ℃ and apply it to the fiber fabric in an amount of 5 ~ 50g / ㎡, then the temperature 30 ~ 50 ℃, By aging for 12 to 48 hours under the condition of 70 to 100% relative humidity, it is possible to maximize heat resistance, adhesive strength, high peel strength and soft touch. In this coated fabric, the flame retardancy of the adhesive is V-0 It is a grade (UL94 vertical method), and the coated fabric has physical properties of heat resistance of 280 to 320 ° C and peel strength of 2 to 12 N / 5 cm.

Hereinafter, an example of an experiment of the highly heat-resistant silicone modified reactive urethane hot-melt adhesive according to the present invention will be described, but a preferred embodiment that can be easily carried out by a person skilled in the art to which the present invention belongs The present invention is explained through

[Examples 1 to 3 / Comparative Examples 1 and 2]

Preparation of reactive urethane hot melt adhesives

Mix 1.34-TCN nanoclay and APTES (3-Aminopropyl triethyoxysilane) in a 1-liter three-necked reflux reactor under a nitrogen atmosphere, stir at 50 to 100 rpm for 2 to 6 hours for 3 hours, and mix evenly with octamethylcyclotetrasiloxane. (Octamethylcyclotetrasiloxane) and tetramethyldisiloxane (Tetramethyldisiloxane) were added, triflic acid was injected at a temperature of 60 ~ 80 ℃, and reaction was performed for 12 ~ 48 hours to form a polydimethylsiloxane nanoclay mixture with a number average molecular weight of 1,000 ~ 2,000. synthesize

0.05 to 0.1% by weight of a metal-vinyl silane complex catalyst was added to the obtained mixture, stirred at a temperature of 60 to 80 ° C, and 2-propen-1-ol (2-propen-1 -ol) is slowly added to induce an initial reaction. Thereafter, the mixture is reacted at a temperature of 90 to 100° C. for 2 to 6 hours and vacuum dried for 24 to 48 hours to prepare an OH-terminated reactive polydimethylsiloxane/nanoclay mixture.

Add MDI and a catalyst to the prepared OH-terminated polydimethylsiloxane nanoclay mixture and react for 2 to 4 hours at a temperature of 80 to 90 ° C. until NCO% = 10 to 15% to prepare a prepolymer. .

Polyester polyol, fluororesin-containing diol, reactive flame retardant, and 1,6-HD were added to the prepared prepolymer, and the reaction was carried out at a temperature of 90 to 100 ° C. for 3 to 5 hours. Then, to remove unreacted isocyanate React for 1 hour under vacuum, complete the reaction in the range of NCO% = 2 ~ 5%, check the viscosity, and then mix antioxidants, additive flame retardants, etc. and stir.

In the same manner as the above process, the preparation of a reactive urethane hot-melt adhesive with different formulations of each component was performed with the composition shown in [Table 1] below.

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Nanoclay (a) 30 10 50 0 0 Silane coupling agent (b) 10 3 20 0 0 Octamethylcyclotetrasiloxane (c) 150 100 300 150 0 tetramethyldisiloxane (d) 90 50 150 90 0 propenol (e) 90 50 150 90 0 Diisocyanate (f) 220 175 313 206 155 Polyester polyol (g) 200 200 200 200 250 Fluororesin-containing Diol (h) 40 40 40 0 50 Reactive flame retardant (i) 60 60 60 60 120 chain extender (j) 10 10 10 10 30 Additive flame retardant (k) 100 100 100 100 100

[Experimental example]

For the reactive urethane hot melt adhesives prepared according to Examples 1 to 3 and Comparative Examples 1 and 2, adhesive strength (peel strength), flame retardancy, heat resistance, touch, etc. were measured by the following methods, and the results are shown in Table 2 below. ].

○ Adhesion strength

An aramid fabric was used as a test piece for testing the adhesive strength (peel strength) of the reactive urethane hot melt adhesive. After melting the reactive urethane hot melt adhesive at a temperature of 100 ° C, it was transferred to the surface of the fabric so that the coating amount was about 25 g / ㎡ using # 152 Gravure roll, and bonded by pressing on the fabric using a rubber roll and a combined roll. . At this time, five specimens were used, and a universal tensile tester owned by the company was used as the testing machine. The breaking load of the tester and the test piece was set within 5 to 85% of the capacity, and after bonding, it was aged for 12 hours at a temperature of 40 ° C and a relative humidity of 70%, and then carried out 5 times.

○ Flame retardant

The reactive urethane hot melt adhesive used the UL94 vertical method to confirm flame retardancy when vertically gluing by making a specimen having a width of 1.3 cm and a length of 12 cm in a similar manner to the heat resistance specimen below.

○ heat resistance

As a method for measuring the heat resistance of the highly heat-resistant silicone-modified reactive urethane adhesive, a 0.5 mm-thick film was prepared using a release paper and a hot melt adhesive, and then a 5 to 10 mg sample was put into TGA and heated to 30 °C at a temperature increase rate of 20 ° C / min. The thermal decomposition temperature of the sample was measured at ~ 600 ° C. under a nitrogen stream, and the temperature at the point where the residual weight of the sample reached 95% was used as the thermal decomposition temperature, and the heat resistance of the samples was compared.

○ Tensile strength

The strength of the specimen prepared for the measurement of heat resistance was measured using a universal tensile tester according to the ASTM 882 method.

○ Touch

The reactive urethane hot melt adhesive and aramid fabric were combined, and 10 experts were selected to measure the average value of the touch (◎: very good, ○: good, △: average, ×: poor).

division Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Peel Strength (N/5cm) 9 12 2 12 15 Flame retardant (UL94) V-0 V-0 V-0 V-1 V-0 Heat resistance (℃) 316 302 318 300 260 Tensile strength (MP) 12 13 8 6 14 touch ◎ ◎ ◎ ◎ ◎

As shown in [Table 2], comparing the experimental results of the reactive urethane adhesives prepared according to Examples 1 to 3 and Comparative Examples 1 and 2, the heat resistance increases as the amount of silicone-modified resin to which nanoclay is applied increases. However, it was confirmed that the tensile strength and peel strength decreased. From the above experimental results, it can be confirmed that Example 1 prepared according to the present invention has relatively excellent heat resistance, peel strength, and flame retardancy.

Therefore, the highly heat-resistant silicone-modified reactive urethane hot-melt adhesive to which the nanoclay and fluororesin-containing diol according to the present invention is applied can be substituted, modified, and changed in various ways without departing from the technical idea of the present invention, and particularly easy to process With one advantage, it can be used in various uses and forms as an eco-friendly material that can be applied in the form of a film or coated on various clothing, automobiles, building materials, etc. as well as surface processing of various textile materials exposed to ultra-high temperature environments.

Claims (6)

(a) preparing a homogenized nanoclay solution by mixing 2 to 5% by weight of organically treated nanoclay and (b) 1 to 2% by weight of a silane coupling agent to improve the dispersibility of the nanoclay;
Polydimethylsiloxane / nanoclay treated to disperse the nanoclay by reacting the mixed nanoclay solution with (c) 10 to 30% by weight of octamethylcyclotetrasiloxane and (d) 5 to 15% by weight of tetramethyldisiloxane synthesizing the mixture;
Here, 5 to 15% by weight of (e) 2-propen-1-ol is slowly added to prepare an OH-terminated reactive polydimethylsiloxane/nanoclay mixture to improve heat resistance. step;
(f) preparing a prepolymer by reacting the OH-terminated reactive polydimethylsiloxane/nanoclay mixture in a ratio of 15 to 30% by weight of aromatic isocyanate;
In the prepolymer prepared above, (g) 15 to 25% by weight of a polyester polyol having a number average molecular weight in the range of 500 to 4,000, (h) 2 to 5% by weight of a fluororesin-containing diol for improving heat resistance, and (i) stable flame retardancy After reacting 5 to 12% by weight of a reactive flame retardant for imparting and (j) 1 to 3% by weight of a chain extender for adjusting initial adhesive strength and strength, (k) 8 to 15% by weight of an addition-type flame retardant for imparting flame retardancy A highly heat-resistant silicone-modified reactive urethane hot-melt adhesive, characterized in that it is prepared by mixing %. According to claim 1,
The organically treated nanoclay (a) has an average size of 5 to 30 including at least one organic functional group selected from methyl, bis hydroxyethyl, and octadecyl ammonium on the surface of the particle A highly heat-resistant silicone-modified reactive urethane hot-melt adhesive characterized in that it is a micro (㎛) inorganic particle. According to claim 1,
The polydimethylsiloxane / nanoclay mixture has a number average molecular weight in the range of 1,000 to 2,000, characterized in that the high heat resistance silicone modified reactive urethane hot melt adhesive. According to claim 1,
High heat resistance silicone modified reactive urethane hot melt adhesive, characterized in that the NCO% of the prepolymer is 10 to 15%. The high heat-resistant silicone-modified reactive urethane hot-melt adhesive according to any one of claims 1 to 4 is melted at a temperature of 80 to 120 ° C and applied to a fiber fabric in an amount of 5 to 50 g / m 2, then the temperature is 30 to 50 ° C, Method for producing a coated fabric made by aging for 12 to 48 hours under conditions of 70 to 100% relative humidity. According to claim 5,
The flame retardancy of the high heat resistance silicone modified reactive urethane hot melt adhesive is V-0 grade (UL94 vertical method), and the coated fabric has a heat resistance of 280 to 320 ° C and a peel strength of 2 to 12 N / 5 cm. .