KR20240084869A - Manufacturing method of solvent-free polyurethane resin coating agent - Google Patents

Abstract

The present invention provides a method for producing a solvent-free polyurethane resin coating, comprising the steps of preparing a base material by mixing a first polyol and glycol; A curing agent manufacturing step of preparing a curing agent by mixing isocyanate and a second polyol; An additive manufacturing step of preparing an additive by mixing a catalyst, antioxidant, UV stabilizer, UV absorber, and NO _x inhibitor; A mixing discharge step of injecting the main ingredient, the curing agent, and the additive into a three-way mixing head through separate injection ports, and mixing them simultaneously with discharge to form a solvent-free polyurethane resin; and a resin maturation step of maturing the solvent-free polyurethane resin at a high temperature of 80° C. or higher to form a solvent-free polyurethane resin coating agent. As a result, a solvent-free polyurethane resin coating agent that is environmentally friendly and exhibits excellent physical properties can be obtained because it does not use organic solvents.

Description

Manufacturing method of solvent-free polyurethane resin coating agent}

The present invention relates to a method for manufacturing a solvent-free polyurethane resin coating, and more specifically, to a method for manufacturing a solvent-free polyurethane resin coating that is environmentally friendly because it does not use organic solvents and exhibits excellent physical properties.

Recently, when manufacturing shoes, car seats, etc., some products are manufacturing seamless type products using skin coating agents such as hot melt coating agents to prevent sewing needle marks from remaining. In the process of manufacturing these coatings, solvent-based polyurethane resin has been used for a long time. Solvent-based polyurethane resin not only has excellent physical properties required as a coating agent, such as wear resistance and bending resistance, but also has excellent adhesion and appearance properties. there is.

However, the solvent-based polyurethane resin used in the process of manufacturing coatings uses organic solvents that are designated as carcinogens, such as dimethylformamide (DMF), methyl ethyl ketone (MEK), and toluene. There is a problem that these organic solvents act as environmental hazards and their use is restricted by global environmental regulations as the industrial environment changes. In addition, the above-mentioned organic solvents have a problem in that they are highly volatile and are a major cause of fires in the workplace.

Therefore, in order to respond to strengthening regulations, related industries are developing water-dispersed polyurethane resins that can replace solvent-based polyurethane resins. However, when water-dispersed polyurethane resins are processed into adhesive films, the resin migrates into the adhesive films. The disadvantage is that the touch becomes hard due to migration, the elasticity decreases, and wrinkles appear in the adhesive film.

Korea Intellectual Property Office Patent No. 10-2174657

The present invention was devised to solve the above problems, and its purpose is to provide a method for manufacturing a solvent-free polyurethane resin coating that is environmentally friendly because it does not use organic solvents and exhibits excellent physical properties.

The above-described object includes a main preparation step of mixing the first polyol and glycol to prepare the main agent; A curing agent manufacturing step of preparing a curing agent by mixing isocyanate and a second polyol; An additive manufacturing step of preparing an additive by mixing a catalyst, antioxidant, UV stabilizer, UV absorber, and NO _x inhibitor; A mixing discharge step of injecting the main ingredient, the curing agent, and the additive into a three-way mixing head through separate injection ports, and mixing them simultaneously with discharge to form a solvent-free polyurethane resin; And a resin maturing step of maturing the solvent-free polyurethane resin at a high temperature of 80°C or higher to form a solvent-free polyurethane resin coating.

Here, the first polyol is a copolymer polyol prepared through a heteroesterification reaction between different types of polyols, and the polyol is selected from at least two types of polyester polyol, polycarbonate polyol, and polyether polyol. Preferably, the heteroesterification reaction includes a temperature raising step of raising the temperature of a mixture of different types of polyols and diacids from room temperature to 220° C. for 6 to 8 hours, and the heated mixture is heated to 10 to 14 degrees Celsius. It is preferable to include a pressure reducing step of reacting while reducing the pressure for a period of time and a cooling step of cooling the reacted mixture to room temperature.

In addition, in the mixing and discharging step, it is preferable that the discharging temperature of the three-way mixing head is adjusted to 120°C and the discharging speed is adjusted to 12 m/min to discharge the main agent, the hardener, and the adhesive, respectively.

As described above, according to the present invention, a solvent-free polyurethane resin coating agent that is environmentally friendly and exhibits excellent physical properties can be obtained because organic solvents are not used.

1 is a flowchart of a method for manufacturing a solvent-free polyurethane resin coating according to an embodiment of the present invention;
Figure 2 is a photograph showing a heat resistance test specimen of the subject matter according to Example 1,
Figure 3 is a photograph showing a UV test specimen of the subject according to Example 1,
Figure 4 is a photograph showing a bending test specimen of the subject according to Example 1;
Figure 5 is a pot life graph according to the mixed amount of a heat-sensitive catalyst and a Zr-based catalyst at 25°C according to Example 3;
Figure 6 is a pot life graph according to the mixed amount of a heat-sensitive catalyst and an amine-based catalyst at 25°C according to Example 3;
Figure 7 is a pot life graph according to the mixed amount of a heat-sensitive catalyst and a Zr-based catalyst at 60°C according to Example 3;
Figure 8 is a pot life graph according to the mixed amount of a heat-sensitive catalyst and an amine-based catalyst at 60°C according to Example 3;
Figure 9 is a pot life graph according to the mixed amount of a heat-sensitive catalyst and a Zr-based catalyst at 80°C according to Example 3;
Figure 10 is a pot life graph according to the mixed amount of a heat-sensitive catalyst and an amine-based catalyst at 80°C according to Example 3;
Figure 11 is a photo of a bending test of a specimen manufactured using the base material and hardener according to Example 4;
Figure 12 is a photo of a water resistance test of a single span fabric specimen manufactured using the base material and hardener according to Example 6;
Figure 13 is a photograph of a water resistance test of an upper fabric specimen manufactured using the base material and hardener according to Example 6.

Hereinafter, the technical idea of the present invention will be described in more detail using the attached drawings. The attached drawings are only an example to explain the technical idea of the present invention in more detail, so the technical idea of the present invention is not limited to the form of the attached drawings.

The non-solvent type polyurethane resin coating according to the present invention is applied to skin for oil-based shoe uppers. Unlike diluting the solvent and toner in an appropriate amount, the coating agent is formed after going through the mixing process by setting the mixing ratio according to the molar ratio of the base material and the hardener. do. However, since the loading time of the resin mixed in the coating roll is different when forming the coating agent, there is ample room for differences in physical properties between the liquid applied initially and the liquid applied later. Therefore, a solvent-free binder is mixed to eliminate the difference in physical properties as much as possible. It is judged to be desirable and most feasible to secure the stability of physical properties by mixing the base material and hardener using a mixing head with the same application method.

It is desirable to prepare the physical properties of the non-solvent type polyurethane resin coating agent according to the present invention to be similar to the physical properties of the solvent type polyurethane resin coating agent, which has the best physical properties among those currently in use. In particular, it is advantageous for the shape of the resin to maintain a liquid state at room temperature for applying a solvent-free polyurethane resin coating agent, and it is preferentially considered to have a low viscosity to enable coating at 30 to 40 ° C. In other words, the goal of the present invention is to produce a solvent-free polyurethane resin coating that can exhibit high physical properties while having a low glass transition temperature (Tg).

The physical properties of the conventional solvent-based polyurethane resin coating agent are shown in Table 1, and based on this, the purpose is to manufacture an eco-friendly solvent-free polyurethane resin coating agent that has no differences in existing physical properties.

100% modulus
(kgf/㎠) Elongation
(%) tensile strength
(kgf/㎠) 50 to 70 300 to 400 350 to 450

As shown in Figure 1, the solvent-free polyurethane resin coating manufacturing method according to the present invention includes a main preparation step (S100), a curing agent preparation step (S200), an additive preparation step (S300), a mixing discharge step (S400), and Includes a resin maturation step (S500).

First, the base material manufacturing step (S100) refers to the step of preparing the base material by mixing the first polyol and glycol.

The first polyol refers to a copolymer polyol produced through a heteroesterification reaction between different types of polyols, rather than a polyol commonly sold on the market. There is a limit to increasing the physical properties of polyols simply by mixing general polyols, so in the present invention, the first polyol in the form of a copolymer polyol is obtained through a separate heteroesterification reaction.

Here, the polyol used in the heteroesterification reaction is selected from at least two types of polyester polyol, polycarbonate polyol, and polyether polyol, as shown in Table 2, and are of different types. A first polymer in the form of a copolymer is formed through a heteroesterification reaction of polyol.

division designation polyester polyol Poly(1,4-butanedol adipate) Poly(methylene glycol 1,4-butanedol adipate) polycarbonate polyol Polycarbonatediol (1,6hd homo) Polycarbonatediol (1,5pd/1,6hd copolymer) polyether polyol Polytetramethylene Ether Glycol

The heteroesterification reaction involves heating a mixture of different types of polyols and dibasic acid from room temperature to 220°C for 6 to 8 hours, and depressurizing the heated mixture for 10 to 14 hours. It consists of a pressure reduction step for reaction and a cooling step for cooling the reacted mixture to room temperature.

Here, the diacid is preferably selected from the group consisting of adipic acid, sebacic acid, and mixtures thereof, but is not limited thereto.

Glycol that is mixed with the first polyol to form the main agent is ethylene glycol, 1,4-butanol, 1,6-hexanediol, neo It is preferably selected from the group consisting of neopentyl glycol, diethylene glycol, 3-methyl-1,5-pentanediol, and mixtures thereof. The physical properties of glycol can be confirmed through Table 3.

designation M.P(℃) B.P(℃) Mw ethylene glycol -12.9 197.3 62.07 1,4-butanol 230 90.12 1,6-hexanediol 250 118.17 neopentyl glycol 129.1 208 104.15 diethylene glycol 244 106.12 3-methyl-1,5-pentanediol <-10 249 118.17

As such, the polyol used in the heteroesterification reaction is preferably a low molecular weight polyol with a molecular weight of 800 to 1,000 Mw, and the first polyol obtained through the heteroesterification reaction is reacted so that the molecular weight is in the range of 2,000 to 2,200 Mw. It is desirable to make it happen.

The hardener preparation step (S200) refers to the step of preparing a hardener by mixing isocyanate and a second polyol.

Isocyanates include aromatic isocyanates such as toluene diisocyanate (TDI), 4,4-diphenyl methane diisocyanate (MDI), xylene diisocyanate (XDI), and aliphatic isocyanate. It is selected from the group consisting of hexamethylene diisocyanate (HDI), which is an isocyanate, isophorone diisocyanate (IPDI), which is an alicyclic isocyanate, cyclohexane diisocyanate (H ₁₂ MDI), and mixtures thereof. The characteristics of these isocyanates are shown in Table 4.

division designation M.P(℃) B.P(℃) Mw aromatic TDI toluene diisocyanate 13 120 174 MDI 4,4-diphenyl methane diisocyanate 37 175 250 XDI xylene diisocyanate -7 188 aliphatic HDI hexamethylene diisocyanate 113 168 Alicyclic tribe IPDI isophorone diisocyanate -60 158 223 H ₁₂ MDI cyclohexane diisocyanate 12 262

Among these, the isocyanate for preparing the curing agent is preferably selected from the group consisting of 4,4-MDI (4,4-diphenyl methane diisocyanate), MI (methyl isocyanate), L-MDI (L-diphenyl methane diisocyanate), and mixtures thereof. However, it is not limited to this.

The second polyol mixed with the isocyanate, like the first polyol, is a copolymer polyol produced through a heteroesterification reaction between different types of polyols, where the polyol is at least one of polyester polyol, polycarbonate polyol, and polyether polyol. Two types are selected. This second polyol may be the same component as the first polyol, but it is more preferable that the second polyol and the first polyol are different components.

In the case of a solvent-based polyurethane resin according to the prior art, processing is performed after additional dilution of an organic solvent to adjust the viscosity appropriate for the addition of additives and roll coating, but in the case of a non-solvent-type polyurethane resin as in the present invention, Since the liquid is used immediately, additives must be prepared in advance.

In other words, when the solvent-based polyurethane resin is appropriately mixed with a crosslinking agent and a solvent-based polyurethane resin of a certain molecular weight, the overall physical properties are formed evenly due to the volatilization of the organic solvent and a relatively long pot life. On the other hand, in the case of non-solvent polyurethane resin, since a separate organic solvent that can lower the viscosity is not used, in order to adjust the viscosity for coating and work, polyol and glycol crosslinking agents with molecular weights too small to be considered as resins must be used. .

It is preferable to mix the base material and the hardener with 100 to 150 parts by weight of the base material and 100 parts by weight of the hardener to correspond to a weight ratio of 1:1 to 1.5:1.

The additive manufacturing step (S300) refers to the step of manufacturing an additive by mixing a catalyst, antioxidant, UV stabilizer, UV absorber, and NO _x inhibitor.

If a catalyst is added during the process of forming a solvent-free polyurethane resin coating, an explosive reaction may occur even if a small amount of catalyst is added because it does not contain an organic solvent that dilutes the base material and hardener. Therefore, in the present invention, it is preferable to use a heat-sensitive catalyst that has low reactivity at low or room temperature and whose reactivity increases as the temperature increases. Here, it is desirable to prepare 0.1 to 0.2 parts by weight of the heat-sensitive catalyst. In addition, it is preferable to prepare the catalyst by additionally mixing 0.01 to 0.1 parts by weight of a zirconium (Zr)-based catalyst or an amine-based catalyst with the heat-sensitive catalyst, and the subsequent maturation process is carried out by this Zr-based catalyst or amine-based catalyst. It could proceed ideally.

If the catalyst is not used or is used in a small amount, the pot life and tacky time for each process are prolonged, which reduces the line speed and increases the aging time, reducing the productivity of the adhesive. On the other hand, if an excessive amount of catalyst is used, the pot life and the time required for each process can be reduced, but there is a problem in that it is difficult to ensure uniformity in physical properties due to the mixture of over-reacted and unreacted products in the roll coater. Therefore, it is desirable to set the optimal amount of catalyst usage by adjusting the pot life and possession time for each process to ensure uniformity of physical properties. This can increase line speed and reduce ripening time as much as possible, thereby increasing production efficiency.

Antioxidant is added to prevent the adhesive from being oxidized by oxygen or other exhaust gases in the atmosphere. Pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxy phenyl)- propionate], Octadecyl 3-(3,5-di-t-butyl-4-hydroxy phenyl)-propionate, 4,4'-Bis(alpha,alpha-dimethylbenzyl)di-phenylamine, polymerized 1,2-dihydro-2 ,2,4-trimethyl quinoline, 2,5-di-t-butyl-4-methylphenol, Hydroquinoline, N,N'-diphenyl-p-phenylenediamine, Tri(nonylatedphenyl)phosphite, 2-Mercaptobenziaidazole, N-Cyclohexythiophthal ilnide and It can be selected from the group consisting of mixtures thereof. 0.3 to 1 part by weight of these antioxidants can be prepared.

UV stabilizer and UV absorber are added to delay discoloration of the coating caused by ultraviolet rays, heat, etc. Prepare 0.3 to 1 part by weight of UV stabilizer and 0.3 to 1 part by weight of UV absorber. It is desirable to do so. In addition, it is preferable to prepare 0.3 to 1 part by weight _of anti _- NO .

After mixing various types of additives like this, they can be prepared separately from the base material and hardener.

The mixing and discharging step (S400) refers to the step of forming a solvent-free polyurethane resin by injecting the base material, curing agent, and additives into a 3-way mixing head through separate injection ports, and then mixing them simultaneously with discharge. do.

Rather than forming a polyurethane resin by pre-mixing the base prepared through the main preparation step (S100), the curing agent prepared through the hardener preparation step (S200), and the additives formed through the additive preparation step (S300), the main agent, curing agent, and additive If it is necessary to manufacture a coating agent in a separate state, polyurethane resin is manufactured by mixing.

When forming a solvent-based polyurethane resin, since an organic solvent is present, the polyurethane resin does not harden even if it is mixed in advance. However, since the present invention does not contain an organic solvent, the base material, hardener, and additives are separately injected into the three-way mixing head in advance to prevent them from mixing with each other, and the three-way mixing head is driven only when necessary to form a solvent-free formulation. Forms a polyurethane resin.

At this time, the discharge temperature of the three-way mixing head is adjusted to 120℃ and the discharge speed is 12m/min to discharge the polyurethane resin and at the same time align the polyurethane resin into a flat film shape. In some cases, if the ratio of base material, hardener, and additives needs to be adjusted, the discharge speed of the three-way mixing head can be adjusted individually rather than adjusting the addition amount. Additionally, the discharge temperature can be individually adjusted depending on the composition.

The resin maturation step (S500) refers to the step of maturing a solvent-free polyurethane resin at a high temperature to form a solvent-free polyurethane resin coating agent.

When the base material, curing agent, and additives are mixed and discharged through the mixing and discharging step (S400), the mixed solvent-free polyurethane resin is discharged and then aligned into a film shape. This solvent-free polyurethane resin is aged at a high temperature. When this happens, a solvent-free polyurethane resin coating is formed. At this time, the maturation temperature is preferably 80°C or higher, and the maturation time is preferably 48 hr or more.

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

<Example 1>

In order to select a composition suitable for a solvent-free polyurethane resin coating agent, experiments were conducted with various compositions and mixing ratios. In Example 1, various subjects were selected while a specific curing agent was prepared, and then the physical properties were confirmed. Table 5 shows polyester polyols of various compositions and curing agents to be applied to topics containing polyester polyols. Here, polyol 1-1 to polyol 1-8 correspond to a state in which different types of polyester polyols are simply physically mixed.

polyester polyol Mixing ratio (parts by weight) polyol 1-1 Poly(1,4-butanedol adipate):
Poly(methylene glycol 1,4-butanedol adipate) 60:40 polyol 1-2 Poly(methylene glycol adipate):
Poly(methylene glycol 1,4-butanedol adipate) 60:40 polyol 1-3 Poly(neopentyl glycol adipate):
Poly(methylene glycol 1,4-butanedol adipate) 60:40 polyol 1-4 Poly(1,6-hexanediol adipate):
Poly(methylene diethylene glycol adipate) 60:40 polyol 1-5 Poly(1,4-butanedol adipate):
Poly(methylene diethylene glycol adipate) 75:25 polyol 1-6 Poly(methylene glycol adipate):
Poly(methylene diethylene glycol adipate) 75:25 polyol 1-7 Poly(neopentyl glycol adipate):
Poly(methylene diethylene glycol adipate) 75:25 polyol 1-8 Poly(1,6-hexanediol adipate):
Poly(methylene diethylene glycol adipate) 75:25 hardener (4.4-MDI, L-MDI) + Poly(methylene glycol 1,4-butanediol adipate)

The melting point of homo type polyester polyol is mostly measured at 45 to 55°C, making it difficult to maintain the liquid temperature close to 50°C for standalone use and difficulty controlling the reaction rate when mixing at high temperatures. Therefore, an attempt was made to make and apply a copolymer type with a relatively low melting point, that is, a high degree of vitrification and high amorphousness, at an appropriate temperature through blending.

The mixing ratio was about 40% for Poly(methylene glycol 1,4-butanedol adipate), which is maintained in a semi-solid form at room temperature, and for Poly(methylene diethylene glycol adipate), it is maintained in a liquid form at room temperature and is relatively The ratio was further reduced and mixed.

polycarbonate polyol Mixing ratio (parts by weight) polyol 2-1 Polycarbonatediol (1,6hd homo):
Polycarbonatediol (1,5pd/1,6hd copolymer) 70:30 polyol 2-2 Polycarbonatediol (1,6hd homo):
Polycarbonatediol (1,4bd/1,6hd copolymer) 70:30 polyol 2-3 Polycarbonatediol (1,6hd homo):
Polycarbonatediol (mpd/1,6hd copolymer) 70:30 hardener (4.4-MDI, L-MDI) + Polycarbonatediol (1,6hd homo)

As shown in Table 6, the homo-type polycarbonate polyol has a high melting point and crystallinity, while the copolymer type has a high degree of vitrification and is maintained in a liquid state at room temperature, so it can be mixed in an appropriate ratio according to the usable temperature.

polyether polyol Mixing ratio (parts by weight) polyol 3-1 Polytetramethylene Ether Glycol, Mw: 2,000
Polytetramethylene Ether Glycol, Mw: 600 65:35 polyol 3-2 Polytetramethylene Ether Glycol, Mw: 1,000
Polytetramethylene Ether Glycol, Mw: 600 70:30 polyol 3-3 Polytetramethylene Ether Glycol, Mw: 2,000
Polytetramethylene Ether Glycol, Mw: 250 65:35 polyol 3-4 Polytetramethylene Ether Glycol, Mw: 1,000
Polytetramethylene Ether Glycol, Mw: 250 70:30 polyol 3-5 Polytetramethylene Ether Glycol, Mw: 2,000
Polypropylene Glycol, Mw: 2,000 65:35 polyol 3-6 Polytetramethylene Ether Glycol, Mw: 1,000
Polypropylene Glycol, Mw: 2,000 70:30 hardener (4.4-MDI, L-MDI) + Polytetramethylene Ether Glycol, Mw: 2,000

As shown in Table 7, in the case of PTMEG (Polytetramethylene Ether Glycol) among polyether-based polyols, if the molecular weight is 1,000 Mw or more, it is in a solid state at room temperature, and if the molecular weight is 650 Mw or less, it remains in a liquid state at room temperature and is mixed to suit the usable temperature. . And in the case of polyethylene glycol, even though it has a large molecular weight, it exists in a liquid state, so it was mixed with PTMEG.

After mixing the base material prepared including polyester polyol, polycarbonate polyol, and polyether polyol with a curing agent, the physical properties of the polyurethane resin coating agent and the film prepared using the coating agent are shown in Tables 8 and 9 as follows. It can be confirmed through . At this time, the mixing ratio of the base material and hardener is mentioned in Table 8, and this mixing ratio also applies to Table 9.

viscosity
(cps/30℃) hydroxyl value
(mgKOH/g) Subject : Hardener
Mixing ratio (parts by weight) polyol 1-1 3,100 221 108:100 polyol 1-2 3,300 223 107:100 polyol 1-3 2,900 223 107:100 polyol 1-4 3,300 224 106.5 : 100 polyol 1-5 3,400 225 106:100 polyol 1-6 3,100 223 107:100 polyol 1-7 3,200 222 107.4:100 polyol 1-8 3,100 221 107.4:100 polyol 2-1 3,600 224 106.5 : 100 polyol 2-2 3,500 223 107:100 polyol 2-3 3,700 222 107.4:100 polyol 3-1 3,100 224 106.5 : 100 polyol 3-2 3,200 225 106:100 polyol 3-3 3,000 224 106.5 : 100 polyol 3-4 3,100 223 107:100 polyol 3-5 2,100 221 107.4:100 polyol 3-6 2,000 223 107:100

tacky time
(80℃×min) pot life
(30℃×min) film properties 100% modulus
(kgf/㎠) elongation
(%) tensile strength
(kgf/㎠) polyol 1-1 15~20 6~8 39 350 280 polyol 1-2 15~20 6~8 38 360 290 polyol 1-3 15~20 6~8 39 340 280 polyol 1-4 15~20 6~8 40 320 290 polyol 1-5 15~20 6~8 39 340 280 polyol 1-6 15~20 6~8 38 350 300 polyol 1-7 15~20 6~8 40 330 290 polyol 1-8 15~20 6~8 41 310 290 polyol 2-1 15~20 6~8 43 330 360 polyol 2-2 15~20 6~8 46 350 350 polyol 2-3 15~20 6~8 44 340 330 polyol 3-1 15~20 6~8 29 520 240 polyol 3-2 15~20 6~8 28 550 250 polyol 3-3 15~20 6~8 30 530 260 polyol 3-4 15~20 6~8 29 500 240 polyol 3-5 15~20 6~8 28 540 250 polyol 3-6 15~20 6~8 31 520 260

Based on the results of physical property confirmation, potential base materials and raw materials for use as hardeners were selected, and the base material was synthesized and manufactured using polyols of heterogeneous copolymer types as shown in Table 10 to meet the required physical properties for each. Physical properties were identified.

copolymer polyol Mixing ratio (parts by weight) polyol 4-1 Poly(1,4-butanedol adipate):
Polytetramethylene Ether Glycol, Mw: 600 60:40 polyol 4-2 Poly(1,4-butanedol adipate):
Polycarbonatediol (1,5pd/1,6hd copolymer) 70:30 polyol 4-3 Poly(1,4-butanedol adipate):
Polypropylene Glycol, Mw: 2,000 80:20 polyol 4-4 Polycarbonatediol (1,6hd homo):
Poly(methylene glycol 1,4-butanedol adipate) 75:25 polyol 4-5 Polycarbonatediol (1,6hd homo):
Poly(methylene diethylene glycol adipate) 70:30 polyol 4-6 Polycarbonatediol (1,6hd homo):
Polytetramethylene Ether Glycol, Mw: 600 75:25 polyol 4-7 Polytetramethylene Ether Glycol, Mw: 2,000 :
Poly(methylene glycol 1,4-butanedol adipate) 60:40 polyol 4-8 Polytetramethylene Ether Glycol, Mw: 2,000 :
Poly(methylene diethylene glycol adipate) 75:25 polyol 4-9 Polytetramethylene Ether Glycol, Mw: 2,000 :
Polycarbonatediol (1,5pd/1,6hd copolymer) 70:30

tacky time
(80℃×min) pot life
(30℃×min) film properties 100% modulus
(kgf/㎠) elongation
(%) tensile strength
(kgf/㎠) polyol 4-1 15~20 6~8 46 390 440 polyol 4-2 15~20 6~8 45 380 450 polyol 4-3 15~20 6~8 46 380 450 polyol 4-4 15~20 6~8 47 390 450 polyol 4-5 15~20 6~8 46 400 440 polyol 4-6 15~20 6~8 44 390 440 polyol 4-7 15~20 6~8 46 390 440 polyol 4-8 15~20 6~8 45 380 450 polyol 4-9 15~20 6~8 46 390 460

As shown in Table 11, as a result of synthesizing a copolymer type polyol and identifying its physical properties, a certain level of physical properties were secured, but it was judged that there was a need to secure the film formation so that the film could be formed a little more quickly among the various factors that may occur during line testing. For this purpose, there are limits to mixing homo-type polyols or copolymer-type polyols, so heterogeneous homo-type polyols are esterified to maintain the physical properties of each but secure the fluidity of the copolymer. Synthesis was carried out.

Heterogeneous polyols were synthesized into copolymer-type ester polyols through an esterification reaction using dibasic acid. The types of polyols and diacids used in synthesis can be confirmed through Table 12.

polyol Igasan polyol 5-1 Polytetramethylene Ether Glycol, Mw: 1,000
Poly(1,4-butanedol adipate), Mw: 1,000 adipic acid polyol 5-2 Polytetramethylene Ether Glycol, Mw: 1,000
Poly(1,4-butanedol adipate), Mw: 800 sebacic acid polyol 5-3 Polycarbonatediol (1,6hd homo), Mw: 1,000
Poly(1,4-butanedol adipate), Mw: 1,000 adipic acid polyol 5-4 Polycarbonatediol (1,6hd homo), Mw: 1,000
Poly(1,4-butanedol adipate), Mw: 800 sebacic acid polyol 5-5 Polycarbonatediol (1,6hd homo), Mw: 1,000
Polytetramethylene Ether Glycol, Mw: 1,000 sebacic acid polyol 5-6 Polycarbonatediol (1,6hd homo), Mw: 1,000
Polytetramethylene Ether Glycol, Mw: 1,000 adipic acid polyol 5-7 Polycarbonatediol (1,6hd homo), Mw: 1,000
polypropylene polyol, Mw: 1,000 adipic acid polyol 5-8 Polycarbonatediol (1,6hd homo), Mw: 1,000
polypropylene polyol, Mw: 800 sebacic acid

The theoretical molecular weight was set to 2,000 to 2,200 to proceed with the esterification reaction. Since the reaction ratio was approximately 2 mol of polyol to 1 mol of diacid, it was confirmed that the amount of dehydration was not large and the acid value did not fluctuate significantly.

General polyester and polyol obtained by esterification using heterogeneous polyol according to the present invention showed relatively high color values, but it was judged that the color was not problematic for application to coating agents, and the physical properties of each were shown in Table 13. Tested.

hydroxyl value
(mgKOH/g) Molecular Weight
(g/mol) Sanga
(mgKOH/g) Chromaticity
(APHA) moisture
(ppm) viscosity
(cps/75℃) polyol 5-1 52.1 2,153.9 0.28 70 280 652 polyol 5-2 55.9 May 2007 0.22 50 270 705 polyol 5-3 53.4 2,101.5 0.23 40 290 685 polyol 5-4 57.1 1,965.3 0.22 50 280 697 polyol 5-5 52.8 2,125.4 0.24 30 270 725 polyol 5-6 55.1 2,036.7 0.25 30 250 720 polyol 5-7 53.2 2,109.4 0.26 40 260 520 polyol 5-8 56.8 1,975.7 0.27 40 270 525

The polyol prepared through the esterification reaction was mixed with glycol to prepare a base material as shown in Table 14, and the physical property results after mixing the prepared base material with a curing agent are shown in Table 15.

polyol glycol Topic 1 polyol 5-1 1,4-butanediol Topic 2 polyol 5-2 1,4-butanediol Topic 3 polyol 5-3 1,4-butanediol Topic 4 polyol 5-4 1,4-butanediol Topic 5 polyol 5-5 1,4-butanediol Topic 6 polyol 5-6 1,4-butanediol Topic 7 polyol 5-7 1,4-butanediol Topic 8 polyol 5-8 1,4-butanediol

tacky time
(80℃×min) pot life
(30℃×min) film properties 100% modulus
(kgf/㎠) elongation
(%) tensile strength
(kgf/㎠) Topic 1 15~20 6~8 42 410 420 Topic 2 15~20 6~8 43 410 340 Topic 3 15~20 6~8 42 430 390 Topic 4 15~20 6~8 42 440 410 Topic 5 15~20 6~8 42 410 420 Topic 6 15~20 6~8 43 410 340 Topic 7 15~20 6~8 42 430 390 Topic 8 15~20 6~8 42 440 410

As a result of checking the physical properties after mixing, it was confirmed that the eight types of polyols obtained through the esterification reaction between different species showed different physical properties from those of increasing the degree of vitrification by adding other raw materials. In particular, the heterogeneous bond with polyester polyol showed strong results in terms of mechanical properties and film formation other than the color, and the heterogeneous bond with polycarbonate polyol had a good overall color of the resin, and the polyester polyol This branch appeared identical to the physical properties, and in the case of PTMEG, the crystallinity that affects film formation was lower than that of polyester polyol or polycarbonate polyol, so it was confirmed that the drying time was longer.

Among the polyols obtained through this heterogeneous esterification reaction, the aging properties of three types (Main 3, 5, and 6) that showed good physical properties after mixing were confirmed. Here, HT-1208 was applied as a solvent-free binder, and B/C was performed using single span fabric.

Heat resistance aging test conditions were confirmed by loading the coated fabric into a 150℃ dry oven and heating it for 2, 4, and 6 hours. UV aging was performed at 50℃ using a UV light tester 3kw (340nm). Aging tests were conducted for 1 hour, 2 hours, and 3 hours. In addition, the degree of light aging and yellowing of each specimen were compared and confirmed with the naked eye.

As shown in Figures 2 and 3, as a result of checking the aging properties, good results were shown in the order of Topic 3 < Topic 5 < Topic 6 on the film, and after producing the specimen, the aging properties were in the order of Topic 3 < Topic 6 < Topic 5. Good results were shown in that order. In the case of Topic 3 to which polyester polyol was applied, it was confirmed that it was relatively uneven when the degree of dye transfer and surface condition were checked in the hydrolysis resistance test. In the case of Topic 5 and Topic 6 of the same series, the same visual comparison is difficult, but the number of ester functional groups compared to molecular weight was confirmed to be relatively non-uniform. It was judged that topic 5, which had fewer subjects, would be slightly more advantageous.

Figure 4 shows a bending test specimen. Subjects 5 and 6 passed the bending test in the 100,000 bending test. Based on these results, we plan to proceed with further synthesis and manufacturing using Subject 5 as the main subject.

<Example 2>

Through Example 1, polyol 5-5 was selected as the polyol for heterogeneous polyesterification reaction, and an attempt was made to find the most suitable curing agent composition mainly based on topic 5 including it. Here, the composition of diisocyanate was a combination of 4,4-MDI (4,4-diphenyl methane diisocyanate), MI (methyl isocyanate), and L-MDI (L-diphenyl methane diisocyanate).

diisocyanate polyol Hardener 1 4,4-MDI, L-MDI Polycarbonatediol, Mw: 2,000 Hardener 2 MI, L-MDI Polycarbonatediol, Mw: 2,000 Hardener 3 4,4-MDI, L-MDI Poly(1,4-butanedol adipate), Mw: 2,000 Hardener 4 MI, L-MDI Poly(1,4-butanedol adipate), Mw: 2,000 Hardener 5 4,4-MDI, L-MDI Polytetramethylene Ether Glycol,
Mw: 2,000 Hardener 6 MI, L-MDI Polytetramethylene Ether Glycol,
Mw: 2,000 Hardener 7 4,4-MDI, L-MDI polyol 5-1 Hardener 8 MI, L-MDI polyol 5-1 hardener 9 4,4-MDI, L-MDI polyol 5-3 Hardener 10 MI, L-MDI polyol 5-3 Hardener 11 4,4-MDI, L-MDI polyol 5-5 Hardener 12 MI, L-MDI polyol 5-5

The physical property results for Curing Agents 1 to 12 obtained through Table 16 can be confirmed through Tables 17 and 18 as follows.

viscosity
(cps/40℃) NCO cont.
(%) Subject : Hardener
Mixing ratio (parts by weight) Hardener 1 3,100 19.1 111.1:100 Hardener 2 2,900 19.1 111.1:100 Hardener 3 3,300 19.1 111.1:100 Hardener 4 3,000 19.2 111.7:100 Hardener 5 2,900 19.1 111.1:100 Hardener 6 3,200 19.3 112.3:100 Hardener 7 3,000 19.2 111.7:100 Hardener 8 3,300 19.2 111.7:100 hardener 9 3,100 19.1 111.1:100 Hardener 10 3,400 19.3 112.3:100 Hardener 11 3,000 19.1 111.1:100 Hardener 12 2,900 19.2 111.7:100

tacky time
(80℃×min) pot life
(30℃×min) film properties 100% modulus
(kgf/㎠) elongation
(%) tensile strength
(kgf/㎠) Hardener 1 15~20 6~8 41 420 310 Hardener 2 15~20 6~8 39 440 390 Hardener 3 15~20 6~8 43 400 330 Hardener 4 15~20 6~8 46 380 460 Hardener 5 15~20 6~8 42 410 430 Hardener 6 15~20 6~8 45 430 420 Hardener 7 15~20 6~8 40 430 340 Hardener 8 15~20 6~8 42 410 420 hardener 9 15~20 6~8 43 410 340 hardener 10 15~20 6~8 42 430 390 Hardener 11 15~20 6~8 42 440 410 Hardener 12 15~20 6~8 45 400 340

NCO cont. was synthesized 1% higher than the solvent-free binder, and the mixing ratio was set and tested based on the NCO cont. measured after synthesis. As a result of fixing topic 5 as the topic, initially adding a curing agent, varying the types of diisocyanate that reacts with the polyol and diisocyanate for dilution after the reaction is completed, and checking the physical property results for each polyol, overall, Mi and L-MDI types were synthesized. The hardener showed better physical properties than the 4,4-MDI and L-MDI combination hardeners. This is believed to be the result of stabilizing the reaction rate and increasing the degree of vitrification according to the isomer as 4,4-MDI and 2,4-MDI are mixed in a certain ratio. Based on these results, the physical properties of the hardener for each polyol showed similar results, and we plan to select the hardener through aging tests and line tests.

<Example 3>

As a result of checking the pot life and tacky free time by applying 0.1 parts by weight of a heat-sensitive catalyst among the additives added to the base material and hardener, the pot life (30℃×min) was 6 to 8 and the tacky free time (60℃×min) was 6 to 8. The result value was 20 or more. Because the tacky free time is too long to conduct a line test, the line speed is reduced and the maturation time is prolonged, which may lead to a decrease in productivity, so we attempted to set an appropriate catalyst and an appropriate amount of catalyst.

The heat-sensitive catalyst applied in the present invention is easy to control tacky time, but is not easy to control tacky free time, which is the opposite phenomenon. Therefore, co-catalysts that are highly compatible with the heat-sensitive catalyst and can maximize the effect must be used together. A test was conducted. First, the TDS of suitable cocatalysts was checked, and pot life tests were conducted at different temperatures for Zr-based catalysts and amine-based catalysts at different prescription amounts for heat-sensitive catalysts. At this time, when the prescribed amount of the heat-sensitive catalyst was applied in excess of 0.2 parts by weight, the effect was minimal, so more than that was not used, and the pot life for each prescribed amount of Zr-based catalyst and amine-based catalyst was confirmed through Table 19. Additionally, Figure 5 is a graph of pot life at 25°C for each mixed amount of Zr-based catalyst, and Figure 6 is a graph of pot life for each mixed amount of amine-based catalyst at 25°C.

25℃(cps)×min Heat-sensitive catalyst 0.1 parts by weight 0.2 parts by weight of thermosensitive catalyst Zr-based catalyst 0.03 parts by weight 35,000
(20min) 28,000
(20min) Zr-based catalyst 0.05 parts by weight 44,000
(20min) 34,000
(20min) Zr-based catalyst 0.1 parts by weight 68,000
(20min) 43,000
(20min) Amine-based catalyst 0.01 parts by weight 57,000
(20min) 95,000
(20min) Amine-based catalyst 0.03 parts by weight 152,000
(20min) 168,000
(20min) Amine-based catalyst 0.05 parts by weight 165,000
(20min) 178,000
(16min) Amine-based catalyst 0.1 parts by weight 178,000
(16min) 162,000
(12min)

First, the reason for confirming the reactivity at room temperature is that when the base material and hardener are introduced into the roll coater through the mixing head, if a rapid reaction occurs, overreactants and unreacted products are mixed, thereby preventing the uniformity of the coating agent. This is because application is difficult and it is difficult to ensure uniformity of physical properties. Therefore, in order to check the progress of the reaction, it is necessary to accurately determine the pot life at low and high temperatures and the film formation time at high temperatures.

Table 20 shows the pot life by prescription amount of Zr-based catalyst and amine-based catalyst at 60°C, Figure 7 is a graph of pot life by Zr-based catalyst mixing amount at 60°C, and Figure 8 is a graph of pot life by amine-based catalyst mix at 60°C. This is a pot life graph by capacity.

60℃(cps)×min Heat-sensitive catalyst 0.1 parts by weight 0.2 parts by weight of thermosensitive catalyst Zr-based catalyst 0.03 parts by weight 135,000
(12min) 205,000
(16min) Zr-based catalyst 0.05 parts by weight 188,000
(12min) 186,000
(12min) Zr-based catalyst 0.1 parts by weight 158,000
(12min) 197,000
(12min) Amine-based catalyst 0.01 parts by weight 149,000
(16min) 164,000
(16min) Amine-based catalyst 0.03 parts by weight 178,000
(16min) 205,000
(16min) Amine-based catalyst 0.05 parts by weight 156,000
(12min) 186,000
(12min) Amine-based catalyst 0.1 parts by weight 198,000
(12min) 126,000
(8min)

Table 21 shows the pot life by prescription amount of Zr-based catalyst and amine-based catalyst at 80°C, Figure 9 is a graph of pot life by Zr-based catalyst mixing amount at 80°C, and Figure 10 is a graph of pot life by amine-based catalyst mix at 80°C. This is a pot life graph by capacity.

80℃(cps)×min Heat-sensitive catalyst 0.1 parts by weight 0.2 parts by weight of thermosensitive catalyst Zr-based catalyst 0.03 parts by weight 162,000
(12min) 195,000
(16min) Zr-based catalyst 0.05 parts by weight 116,000
(8min) 164,000
(8min) Zr-based catalyst 0.1 parts by weight 175,000
(8min) 199,000
(8min) Amine-based catalyst 0.01 parts by weight 65,000
(4min) 78,000
(4min) Amine-based catalyst 0.03 parts by weight 179,000
(8min) 198,000
(8min) Amine-based catalyst 0.05 parts by weight 116,000
(8min) 135,000
(8min) Amine-based catalyst 0.1 parts by weight 97,000
(8min) 102,000
(8min)

As a result of evaluating the pot life and tacky free time by using a mixed catalyst in this way, it was confirmed that the reactivity was slow at room temperature, the reaction proceeded slowly at a low temperature of 60℃, and the reaction proceeded rapidly at a heated aging temperature of 80℃. . In particular, when amine-based catalysts are mixed, heat maturation proceeds ideally, but the reaction rate progresses relatively quickly even at a low temperature of 60°C and at room temperature, so the initial and late liquids are mixed, which can be a problem during roll coating. Because differences in viscosity and physical properties may occur, the present invention evaluated that a catalyst using a mixture of 0.2 parts by weight of a heat-sensitive catalyst and 0.1 parts by weight of a Zr-based catalyst was the best.

It was confirmed that the catalyst mixed with 0.2 parts by weight of the heat-sensitive catalyst and 0.1 parts by weight of the Zr-based catalyst had a pot life (30°C × min) of 8 to 10 and a tacky free time (80°C × min) of 4 to 6. .

<Example 4>

A total of 18 types of coating agents were prepared by cross-mixing the base material obtained through Example 1 and the curing agent obtained through Example 2, and specimens coated with each coating agent were manufactured and then tested for flexibility. Here, HT-1208 was used as the solvent-free binder, and single span fabric was used as B/C. The base material and hardener used here are summarized in Table 22.

polyol glycol Topic 3 polyol 5-3 1,4-butanediol Topic 5 polyol 5-5 1,4-butanediol Topic 6 polyol 5-6 1,4-butanediol diisocyanate polyol Hardener 2 MI, L-MDI Polycarbonated diol Hardener 4 MI, L-MDI Poly(1,4-butanedol adipate) Hardener 6 MI, L-MDI Polytetramethylene Ether Glycol Hardener 8 MI, L-MDI polyol 5-1 Hardener 10 MI, L-MDI polyol 5-3 Hardener 12 MI, L-MDI polyol 5-5

Topic 3 Topic 5 Topic 6 Hardener 2 × ○ × Hardener 4 × ○ × Hardener 6 × ○ ○ Hardener 8 ○ ○ ○ Hardener 10 ○ ○ ○ Hardener 12 ○ ○ ○

* ○: Good, ×: Burst

As shown in Table 23 and Figure 11, acceptance was determined based on the bursting phenomenon of a total of 18 specimens manufactured using the base material and curing agent, and as a result of the flexibility test, in the case of the curing agent manufactured using polyol alone, the heterogeneous polyol was applied. It was confirmed that it was more vulnerable to bending than the hardener. In the case of topic 5, regardless of the hardener tested, all showed good results with no bursting phenomenon, which is believed to be a result of the ductility effect of the ether type and the relatively small difference in the number of ester group bonds.

<Example 5>

Through Example 4, a coating agent was prepared by mixing a UV stabilizer, UV absorber, antioxidant, and _NO

0 parts by weight 0.3 parts by weight 0.5 parts by weight 0.7 parts by weight 1.0 parts by weight Topic 5
Hardener 8 antioxidant × ○ ◎ ◎ ◎ UV stabilizer × ○ ◎ ◎ ◎ UV absorber × ○ ◎ ◎ ◎ _NOx inhibitor × ○ ◎ ◎ ◎ Topic 6
Hardener 8 antioxidant × ◎ ◎ ◎ ◎ UV stabilizer × △ ◎ ◎ ◎ UV absorber × △ ○ ○ ◎ _NOx inhibitor × ○ ◎ ◎ ◎ Topic 5
Hardener 10 antioxidant × ◎ ◎ ◎ ◎ UV stabilizer × ○ ◎ ◎ ◎ UV absorber × ○ ◎ ◎ ◎ _NOx inhibitor × ○ ◎ ◎ ◎ Topic 6
Hardener 10 antioxidant × ○ ○ ◎ ◎ UV stabilizer × △ ○ ○ ◎ UV absorber × △ ○ ○ ◎ _NOx inhibitor × ○ ○ ◎ ◎ Topic 5
Hardener 12 antioxidant × ◎ ◎ ◎ ◎ UV stabilizer × ○ ◎ ◎ ◎ UV absorber × ○ ◎ ◎ ◎ _NOx inhibitor × ○ ◎ ◎ ◎ Topic 6
Hardener 12 antioxidant × ○ ◎ ◎ ◎ UV stabilizer × △ ○ ○ ◎ UV absorber × △ ○ ○ ◎ _NOx inhibitor × △ ○ ◎ ◎

*◎: Very good, ○: Good, △: Average, ×: Bad

As shown in Table 24, additives were added to the base material and hardener and then mixed to produce a film, and an aging test of the film was performed. In most cases, when more than 0.7 parts by weight of additives were applied, the aging properties showed good values, but there were disadvantages such as migration that occurred when excessive amounts of additives were used. After checking the degree of aging yellowing, the aging properties were checked mainly for relatively good films. As a result, coatings consisting of base 5 + hardener 8, base 5 + hardener 10, and base 5 + hardener 10 showed relatively good aging properties compared to the amount of additive used.

<Example 6>

As shown in Table 25, a coating containing a base material and a hardener was prepared, and a water resistance test was performed on a specimen coated with the coating using an autoclave. Here, antioxidants, UV absorbers, UV stabilizers, and NO _x inhibitors were all added at 0.5 parts by weight.

The conditions for the water resistance test were that 3L of water was placed in a container and the test was conducted at 120°C for 48 hours at 1.0 to 1.2 bar while preventing the specimen from contacting water. At this time, the degree to which the specimen's bone shape was maintained and whether the coating layer was melting were checked.

subject hardener Coating 1 Polycarbonated diol +
Polytetramethylene Ether Glycol +
sebacic acid +
1,4-butanediol
(Topic 5) Polytetramethylene Ether Glycol +
Poly(1,4-butanedol adipate) +
adipic acid +
MI+L-MDI
(Hardener 8) Coating 2 Polycarbonated diol +
Polytetramethylene Ether Glycol +
sebacic acid +
1,4-butanediol
(Topic 5) Polycarbonated diol +
Poly(1,4-butanedol adipate) +
adipic acid +
MI+L-MDI
(Hardener 10) Coating agent 3 Polycarbonated diol +
Polytetramethylene Ether Glycol +
sebacic acid +
1,4-butanediol
(Topic 5) Polycarbonated Diol +
Polytetramethylene Ether Glycol +
sebacic acid +
MI+L-MDI
(Hardener 12)

Figure 12 is a photograph showing the results of a water resistance test of a specimen to which coating agents 1 to 3 were applied to a single span fabric, and Figure 13 shows the results of a water resistance test of a specimen to which coating agents 1 to 3 were applied to a TPU fabric. It's a photo. In all of these specimens, there seemed to be no collapse of the bone, and the condition of the top and bottom of the bone was good with no collapse in the case of Coating Agent 2 and Coating Agent 3. On the other hand, in the case of Coating 1, the top of the valley looked good, but the bottom surface appeared to be slightly melted, which was judged to be a melting of the epidermal layer. Therefore, in the subsequent process, tests were conducted using Coating Agent 2 and Coating Agent 3.

<Example 7>

UV and heat aging resistance properties were tested using a specimen manufactured in the same manner as in Example 6, and the heat aging resistance test results are shown in Table 26.

Heat aging test (120℃) existing 1day 3day 5day 7 days Coating agent 2 100%
MOD Lab 45 40 35 31 29 Line 45 40 36 32 30 EL Lab 385 395 430 440 455 Line 385 400 425 440 460 TS Lab 325 305 285 265 250 Line 335 310 290 265 255 Coating agent 3 100%
MOD Lab 46 40 36 33 31 Line 46 41 36 34 31 EL Lab 395 415 430 445 455 Line 390 410 425 445 450 TS Lab 335 310 295 280 265 Line 330 315 295 280 270

Looking at the numerical results of the heat aging test, the difference in aging properties between the specimen produced in the lab and the film produced slightly during the line test is judged to be within the error range, so the results tested in the lab can be trusted for aging property values. It is judged.

UV aging test (3kw) existing 1hr 2hr 4hrs 6hrs Coating agent 2 100%
MOD Lab 45 38 33 28 25 Line 45 38 34 29 26 EL Lab 385 405 440 460 475 Line 385 400 435 460 470 TS Lab 325 310 295 270 255 Line 335 315 300 280 270 Coating agent 3 100%
MOD Lab 46 42 38 35 31 Line 46 41 38 36 32 EL Lab 395 405 420 435 450 Line 390 405 425 435 445 TS Lab 335 315 305 285 270 Line 300 315 300 280 270

Table 27 shows the UV aging test results. As with the heat aging test results, the difference in aging properties between the specimen produced in the lab and the film produced slightly during the line test is judged to be within the error range.

Through these examples, the solvent-free polyurethane resin coating obtained through the manufacturing method according to the present invention is environmentally friendly because it does not use solvents, unlike using organic solvents to produce conventional coatings. It was confirmed that even without using an organic solvent, it exhibits excellent physical properties similar to coatings manufactured using organic solvents.

The present invention is not limited to the above-described embodiments, and the scope of application is diverse. Of course, various modifications and implementations are possible without departing from the gist of the present invention as claimed in the claims.

S100: Subject manufacturing stage
S200: Hardener manufacturing step
S300: Additive manufacturing step
S400: Mixed discharge step
S500: Resin maturation stage

Claims (4)

A base manufacturing step of preparing a base material by mixing the first polyol and glycol;
A curing agent manufacturing step of preparing a curing agent by mixing isocyanate and a second polyol;
An additive manufacturing step of preparing an additive by mixing a catalyst, antioxidant, UV stabilizer, UV absorber, and NO _x inhibitor;
A mixing discharge step of injecting the main ingredient, the curing agent, and the additive into a three-way mixing head through separate injection ports, and mixing them simultaneously with discharge to form a solvent-free polyurethane resin; and
A resin maturation step of maturing the solvent-free polyurethane resin at a high temperature of 80°C or higher to form a solvent-free polyurethane resin coating. According to clause 1,
The first polyol is,
It is a copolymer polyol produced through heterogeneous esterification reaction between different types of polyols.
The polyol is a method for producing a solvent-free polyurethane resin coating, characterized in that at least two types are selected from polyester polyol, polycarbonate polyol, and polyether polyol. According to clause 2,
The heteroesterification reaction is,
A temperature raising step of raising the temperature of the mixture of different types of polyols and diacids from room temperature to 220°C for 6 to 8 hours,
A pressure reduction step of reacting the heated mixture under reduced pressure for 10 to 14 hours, and
A method for producing a solvent-free polyurethane resin coating, comprising a cooling step of cooling the reacted mixture to room temperature. According to clause 1,
The mixing discharge step is,
A method for manufacturing a solvent-free polyurethane resin coating, characterized in that the discharge temperature of the three-way mixing head is adjusted to 120°C and the discharge speed is 12 m/min to discharge the main agent, the hardener, and the adhesive, respectively.