KR100901115B1 - Polyurethane foam compositions for pipes insulation and manufacturing method thereof and foam therefrom - Google Patents

Abstract

A polyurethane foam composition is provided to maintain proper reactivity at a high temperature, to ensure excellent mechanical strength preventing cracking, carbonization, weakening of adhesive force and fire retardant characteristic. A polyurethane foam composition for insulation pipe includes mixed polyols, mixed isocyanates, catalyst, foaming agent and surfactant. The mixed polyols comprises (i) polyester polyol polymerized with glycol in highly functional aromatic polyester polyol; (ii) Mannich base polyether polyol obtained by adding propylene oxide and ethylene oxide to the Mannich base; (iii) sucrose polyether polyol obtained by adding propylene oxide and butylene oxide to sucrose or sorbitol; (iv) glycol polyether polyol obtained by adding styrene oxide butylene oxide to glycol; and (v) bisphenol A polyether polyol obtained by adding styrene oxide and butylene oxide to bisphenol A.

Description

Polyurethane foam composition for pipe insulation, and a method for manufacturing the same and a foam produced thereby {POLYURETHANE FOAM COMPOSITIONS FOR PIPES INSULATION AND MANUFACTURING METHOD THEREOF AND FOAM THEREFROM}

The present invention relates to a polyurethane foam composition for pipe insulation, a method for producing the same, and a foam produced by the same. More specifically, a modified isocyanate and a polymer 4,4 are mixed by mixing a polyester polyol and a polyether polyol with enhanced heat resistance. The present invention relates to a polyurethane foam composition for pipe insulation which is stably foamed even at high temperature by mixing diphenylmethane diisocyanate, and has excellent heat insulating performance and mechanical strength, and a method for producing the same and a foam produced by the same.

Polyurethane resins, which are typical of thermosetting resins, are relatively inexpensive and easy to mold, and their foams are widely used throughout household goods including automobile parts. As a method of manufacturing such a thermoplastic polyurethane foam, the chemical foaming method using thermally decomposable foaming agents, such as azodicarbonamide, is known by Unexamined-Japanese-Patent No. 7-157588.

In addition, polyurethane foams are generally used in refrigerators, freezing containers, low-temperature warehouses, etc., which require high heat insulation as an excellent heat insulating material among organic and inorganic heat insulating materials. This is because the polyurethane foam is composed of independent bubbles and excellent heat insulation, it is possible to produce a low density foam by adjusting the amount and type of foam. However, polyurethane resins are flammable and have a large disadvantage of poor heat resistance.

In other words, most of the currently used rigid polyurethane foam is used by foaming at a temperature of 10 ~ 50 ℃, when the temperature is higher than that the foam overexposure (過 發泡), carbonization, sponge phenomenon occurs due to rapid foaming As a result, it is difficult to properly control the reactivity so that empty spaces (unfilled) are generated inside the foamed object, or problems such as cracking inside the foam occur.

Therefore, in order to cut the heat insulated material of such high temperature pipes, the temperature should be lowered below the working temperature from 110 to 120 ° C to 50 ° C, which means that the flow of heat medium flowing inside should be stopped. Since the supply must be stopped, not only does it cause inconvenience to consumers' lives, but it also causes an increase in expenses by exchanging new products made at the factory to shorten the working time.

Thus, even if the temperature of the contact surface is 80 ~ 120 ℃ high temperature maintains the proper reactivity, even after the foam is formed 110 ~ 120 ℃ high temperature maintains its thermal insulation performance, excellent mechanical strength and flame retardancy and excellent adhesion to the foam object There has been a need for development of polyurethane foams for high temperature pipe insulation to maintain their properties.

Accordingly, an object of the present invention is to solve such a conventional problem, the conventional polyurethane foam is difficult to adequately control the reactivity at high temperature, so that empty space (unfilled) occurs inside the foam object, or inside the foam In contrast to the occurrence of cracks, the polyurethane foam composition for thermal insulation of pipes with excellent mechanical strength is maintained even at high temperatures, and even after the foam is formed, cracks, carbonization, and weakening of the adhesive force do not occur. A method and a foam produced thereby are provided.

Pipe insulation polyurethane foam composition of the present invention for achieving the above object is a polyurethane foam composition for pipe insulation containing a mixed polyol, mixed isocyanate, catalyst, foaming agent, surfactant, the mixed polyol ( 1) polyester polyols obtained by polymerizing glycols to aromatic high functional polyester polyols; (2) Mannich base polyether polyols obtained by adding propylene oxide and ethylene oxide to Mannich Base; (3) Sucrose polyether polyol obtained by adding propylene oxide and butylene oxide to sucrose or sorbitol; (4) glycol polyether polyols obtained by adding styrene oxide and butylene oxide to glycol; (5) a bisphenol a polyether polyol obtained by adding styrene oxide and butylene oxide to bisphenol a; and the mixed isocyanates include modified diphenylmethane diisocyanate and polymeric 4,4-diphenylmethane diisocyanate. It is characterized by including.

In the polyurethane foam composition for pipe insulation according to the invention, Preferably, the mixed polyol is 10 to 50% by weight of the polyester polyol; 10-30% by weight of the group Mannich base polyether polyol; 20 to 50% by weight of the sucrose polyether polyol; 10 to 30% by weight of the glycol polyether polyol; 10 to 30% by weight of the bisphenol-A polyether polyol; wherein the mixed isocyanate has a functional group of 1.8 to 2.5, the isocyanate group (NCO) content% of 30 to 40, the ratio of 2,4- isomer (Isomer) The polymeric 4 having 40 to 80% by weight of the modified diphenylmethane diisocyanate with a functional group of 2.6 to 2.9, a content of isocyanate group (NCO) of 28 to 35, and a viscosity of 350 to 700 centipoise (CPS). And 4-diphenylmethane diisocyanate.

In addition, the weight ratio of the isocyanate group (NCO) of the mixed isocyanate to the hydroxyl group (-OH) of the mixed polyol is 1.3 to 3.5, the mixed polyol is characterized in that the hydroxyl group (-OH) value is 350 to 650.

The catalyst is an amine catalyst, and comprises 0.05 to 1.5 parts by weight based on 100 parts by weight of the mixed polyol, and the blowing agent consists of 1 to 5 parts by weight of water (H ₂ O) based on 100 parts by weight of the mixed polyol or 0.5 to 2 parts by weight of water (H ₂ O) and 10 to 30 parts by weight of hydrochlorofluorocarbon (HCFC) based on 100 parts by weight of the mixed polyol, and the surfactant has a molecular weight of 3000 to 7000 g / mol and a viscosity It is a polysiloxane ether of 100 to 2000 centipoise (CPS), characterized in that 1 to 4 parts by weight based on 100 parts by weight of the mixed polyol.

Next, the production method of the polyurethane foam composition for pipe insulation of the present invention for achieving the above object,

10 to 50% by weight of a polyester polyol obtained by polymerizing glycol to an aromatic high functional polyester polyol, 10 to 30% by weight of Mannich base polyether polyol obtained by adding propylene oxide and ethylene oxide to Mannich Base, and 20-50 wt% of sucrose polyether polyol obtained by adding propylene oxide and butylene oxide to loose or sorbitol, 10-30 wt% of glycol polyether polyol obtained by adding styrene oxide and butylene oxide to glycol, bisphenol A first mixing step of preparing a reaction solution by mixing a mixed polyol, a catalyst, a blowing agent, and a surfactant, in which 10 to 30% by weight of a bisphenol A polyether polyol obtained by adding styrene oxide and butylene oxide is mixed; A second mixing step of preparing a mixed isocyanate by mixing a modified diphenylmethane diisocyanate and a polymeric 4,4-diphenylmethane diisocyanate; And a reaction step of reacting the reaction solution with the mixed isocyanate.

In the method for producing a polyurethane composition foam for pipe insulation according to the present invention, Preferably, the reaction step is a low pressure or 50 to 200 bar of the reaction to react by mechanically mixing at a pressure of 1 to 10 bar The mixed isocyanate has a functional group of 1.8 to 2.5, and an isocyanate group (NCO) content of 30 to 40, 2,4-isomer (Isomer). The modified diphenylmethane diisocyanate having a ratio of 40 to 80% by weight) and a functional group of 2.6 to 2.9, an isocyanate group (NCO) content of 28 to 35, and a viscosity of 350 to 700 centipoise (CPS). It is characterized by including a polymeric 4,4-diphenylmethane diisocyanate.

In addition, the weight ratio of the isocyanate group (NCO) of the mixed isocyanate to the hydroxyl group (-OH) of the mixed polyol is 1.3 to 3.5, the mixed polyol is characterized in that the hydroxyl group (-OH) value of 350 to 650, The catalyst is an amine catalyst, characterized in that it comprises 0.05 to 1.5 parts by weight based on 100 parts by weight of the mixed polyol, the blowing agent is 1 to 5 parts by weight of water (H ₂ O) based on 100 parts by weight of the mixed polyol Or 0.5 to 2 parts by weight of water (H ₂ O) and 10 to 30 parts by weight of hydrochlorofluorocarbon (HCFC) based on 100 parts by weight of the mixed polyol, and the surfactant has a molecular weight of 3000 to 7000 g / mol. It is a polysiloxane ether having a viscosity of 100 to 2000 centipoise (CPS), and characterized in that 1 to 4 parts by weight based on 100 parts by weight of the mixed polyol.

According to the polyurethane foam composition for pipe insulation of the present invention, and a method for manufacturing the same, and the foam produced therefrom, over-expanding and carbonization by minimizing the effects of external resistance and internal temperature even at a high temperature of about 80 to 120 ℃ pipe surface temperature Without filling the sponge, the mold can be filled without filling the mold, and has the advantage of maintaining excellent adhesiveness and excellent thermal insulation performance with the foam object.

In addition, since it is possible to work even at a high temperature of about 80 to 120 ° C. at the time of damage to the high-temperature pipe, there is no need to interrupt the flow of the heat flow agent therein, thereby reducing the working time and reducing the cost.

In addition, even if the pipe contact surface is a high temperature maintains the proper reactivity, even after forming the foam exhibits excellent mechanical strength that does not occur, the cracking, carbonization, weakening of the adhesive force, and also has an excellent flame resistance.

Hereinafter, an embodiment of the polyurethane foam composition for pipe insulation according to the present invention will be described.

 The polyurethane foam composition for pipe insulation comprises basically a mixed polyol, a mixed isocyanate, a catalyst, a blowing agent, and a surfactant.

First, the mixed polyol will be examined in the polyurethane foam composition for pipe insulation of the present invention.

The mixed polyol is a polyester polyol obtained by polymerizing glycol to an aromatic high functional polyester polyol, and a propylene oxide to a Mannich base polyether polyol, sucrose or sorbitol obtained by adding propylene oxide and ethylene oxide to a Mannich Base. Sucrose polyether polyol obtained by adding an oxide and butylene oxide, glycol polyether polyol obtained by adding styrene oxide and butylene oxide to glycol, bisphenol a polyether obtained by adding styrene oxide and butylene oxide to bisphenol It is made by mixing polyols.

In the mixed polyol composition, sorbitol (or sucrose) and mannibase components are effective in improving the dimensional stability and mechanical strength of the foam when mixed in an appropriate ratio, and the glycol component has fluidity and adhesion in the process of foam formation. It increases the viscosity and contributes to lowering the viscosity of the stock solution. In addition, the bisphenol A component contributes to the improvement of thermal conductivity and uniform formation of foam bubbles, and the polymerized aromatic high functional polyester polyol has excellent thermal stability, which improves curing and has excellent oil resistance. It should be mixed with polyol in proper ratio.

Here, the titration ratio is a result of several experiments, 10 to 50% by weight of the polyester polyol, 10 to 30% by weight of the Mannich base polyether polyol, 20 to 50% by weight of the sucrose polyether polyol, the glycol poly 10-30% by weight of ether polyol and 10-30% by weight of the bisphenol-A polyether polyol are suitable for maximizing the effects of the present invention, such as heat resistance and mechanical strength.

In addition, the mixed polyol is most preferably a hydroxyl group (-OH) value of 350 to 650. If the hydroxyl group (-OH) value of the mixed polyol is less than 350, the formation reaction and crosslinking reaction may not occur, resulting in poor dimensional stability and mechanical strength of the product.If the hydroxyl group (-OH) value is over 650, the overall physical property value becomes weak. Since the adhesive strength is lowered, the hydroxyl group (-OH) value out of the above-mentioned proper range becomes a cause of product defects and there is a problem that the productivity is lowered.

Here, the hydroxyl group (-OH) value is a value which represents the hydroxyl group (-OH) in a molecule | numerator as KOH equivalent, and it is a value which can be measured if only a hydroxyl group (-OH) exists in a molecule | numerator. Every polyol (a polyol means a lot of hydroxy groups (-OH)) has a hydroxyl group (-OH) in its molecule, so each has a hydroxy value. Therefore, the hydroxyl group (-OH) value of a substance having a hydroxyl group (-OH) becomes the intrinsic property of the substance.

The following briefly illustrates a method for arithmetically calculating a hydroxyl group (-OH) value.

                    56100 * Hydroxy Functional Group

     PPG Molecular Weight = ---------------------------

                        Hydroxy group (-OH) value

** Molecular weight (mg) of potassium hydroxide (KOH): [K (39.1) + O (16) + H (1)] * 1000 = 56,100

Example) 1. Glycerin (molecular weight = 92)

                           56100 * 3 (hydroxyl functional group of glycerin)

                1829 = ------------------------------------------

        (Hydroxy group (-OH) value) 92 (molecular weight of glycerin)

Example) 2. Propylene glycol (molecular weight = 76)

                        56100 * 2 (hydroxy functional group number of propylene glycol)

          1476 = ----------------------------------------------

  (Hydroxy group (-OH) value) 76 (molecular weight of propylene glycol)

Next, the mixed isocyanate will be examined in the polyurethane foam composition for pipe insulation of the present invention.

The mixed isocyanate is obtained by mixing modified diphenylmethane diisocyanate (MDI) with polymeric 4,4-diphenylmethane diisocyanate.

In the mixed isocyanate, the modified diphenylmethane diisocyanate (MDI) has a functional group of 1.8 to 2.5, an isocyanate group (NCO) content% of 30 to 40, and a ratio of 2,4-isomer of 40 to 80% by weight. The polymeric 4,4-diphenylmethane diisocyanate has a functional group of 2.6 to 2.9, an isocyanate group (NCO) content of 28 to 35, and a viscosity of 350 to 700 centipoise (CPS). use.

For this reason, the modified diphenylmethane diisocyanate (MDI) component enhances adhesion to the adherend, but when the content of the isocyanate group (NCO) of the modified diphenylmethane diisocyanate (MDI) component is less than 30%, It is not expected to improve, and if it exceeds 40%, the adhesion, compression, and tensile strength will be lowered. In the case of 4,4-diphenylmethane diisocyanate used together, the dimension of the isocyanate group (NCO) content is less than 28% This is because if the stability falls and exceeds 35%, the fluidity is lowered.

In addition, the reaction ratio of the mixed isocyanate component and the mixed polyol component is preferably NCO / OH of 1.3 to 3.5, more preferably a weight ratio of the isocyanate group (-NCO) of the mixed isocyanate component and the hydroxyl group (-OH) of the mixed polyol, more preferably. Is preferably from 1.4 to 2.5. When the ratio of NCO / OH is less than 1.3, the polyurethane foam is weakened, so that the dimensional stability is lowered and the mechanical strength is decreased. When the ratio of NCO / 0H is greater than 3.5, the polyurethane foam is broken.

When the NCO / OH ratio is 1.3 to 3.5, the isocyanate is present in excess. In this case, the remaining isocyanate forms allophanate and biuret through addition reaction due to the completion of polyurethane foam formation. Physical properties are improved. The isocyanate at high temperature forms strong isocyanurate bond through its own reaction, which is stronger than general urethane bond, so it is not easily broken. It is improved in chemical stability and thermal stability, and it is excellent in heat and flame resistance. It is possible to maintain low thermal conductivity. Therefore, when the blending ratio of the mixed polyol component and the mixed isocyanate component to be reacted is outside the above range, the object of the present invention cannot be achieved.

Next, the catalyst will be examined in the polyurethane foam composition for pipe insulation of the present invention.

Catalysts used in the present invention are typical catalysts that can be used to obtain polyurethane foams, for example triethylamine, tripropylamine, triisopropanolamine, tributylamine, trioctylamine, hexadecyldimethylamine, tris ( 3-dimethylamino) propylhexahydrotriamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, diethanolamine, dimethylethanolamine, triethanolamine, N-methyldiethanol Amines, N, N-dimethylethanolamine, diethylenetriamine, N, N, N ', N'-tetramethylbutanediamine, N, N, N', N'-tetramethyl-1,3-butanediamine, N, N, N ', N'-tetraethylhexamethylenediamine, bis [2- (N, N-dimethylamino) ethyl] ether, N, N'-dimethylbenzylamine, N, N-dimethylcyclohexylamine, N, N, N ', N', n'-pentamethyldiethylenetriamine, triethylenediamine, formic acid and other salts of triethylenediamine, of first and second amines Mino groups, oxyalkylene adducts, azacyclic compounds such as N, N-dialkyl piperazines, β-aminocarbonyl catalysts of various N, N ', N'-trialkylaminoalkylhexahydrotriazines, and the like. Is an amine catalyst.

It is preferable to use these catalysts individually or in mixture, and the usage-amount is 0.05-1.5 weight part with respect to 100 weight part of said mixed polyol components, More preferably, 0.1-0.9 weight part is suitable. Here, when the amount of the catalyst is less than 0.05 parts by weight, in the reaction for the present invention, the rigid polyurethane foam production reaction is incomplete, so that the physical properties can be reduced, the role of the catalyst can not be expected, if the amount exceeds 1.5 parts by weight excessively This activity is difficult to control, and there is a problem that carbonization (Scorch) or sponge phenomenon may occur.

Next, the foaming agent is examined in the polyurethane foam composition for pipe insulation of the present invention.

According to the present invention, the blowing agent uses hydrochlorofluorocarbon (HCFC) as water (H ₂ O) or fluorocarbon blowing agent. When water (H ₂ O) is used alone, 1 to 5 parts by weight based on 100 parts by weight of the mixed polyol component is used, and water (H ₂ O) and hydrochlorinated fluorocarbon (HCFC) are mixed when water ( It is preferable to use 0.5 to 2 parts by weight of H ₂ O) and 10 to 30 parts by weight of hydrochlorofluorocarbon (HCFC). In this case, when water (H ₂ O) is used alone, when water (H ₂ O) is used in an amount less than 1 part by weight, the desired density does not come out. When it exceeds 5 parts by weight, the insulation of the polyurethane foam is inferior and the foam is broken. The adhesive force with the face material is also weakened.

Next, the surfactant will be examined in the polyurethane foam composition for pipe insulation of the present invention.

According to the present invention, the surfactant uses a polysiloxane ether as an organosilicon compound. The amount of the surfactant used at this time is preferably 1 to 4 parts by weight, more preferably 1.5 to 3 parts by weight based on 100 parts by weight of the mixed polyol component. If the amount of the surfactant is less than 1 part by weight, it is impossible to prevent the diffusion of the gas by foaming, and if it exceeds 4 parts by weight, the surface tension of the reactants is lowered to prevent the collapse of the closed cell structure. The effect of the surfactant is almost eliminated. In addition, the viscosity of the surfactant is 100 to 2000 centipoise (cps), the molecular weight is preferably 3,000 to 7,000 g / mol. Viscosity and molecular weight in the above range is suitable for maximizing the suitability and reactivity between materials in the reaction of the surfactant with other raw materials.

In addition, in the polyurethane foam composition of the present invention, a crosslinking agent may be used to reinforce the strength of the polyurethane foam and to shorten the curing time. Ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, glycerol, and butanediol can also be used individually or in mixture of 2 or more types. Particularly, the preferred crosslinking agent is polyethylene glycol or butanediol, and the amount thereof is preferably 2 to 15 parts by weight, more preferably 3 to 5 parts by weight based on 100 parts by weight of the mixed polyol component.

In addition, a flame retardant may be added to further enhance the flame retardancy of the polyurethane foam of the present invention. Flame retardants used in the present invention include tris (2-chloroethyl) phosphate, tris (chloropropyl) phosphate, tris (dipropopropyl) phosphate and the like. When using a flame retardant, the usage-amount is 5-20 weight part with respect to 100 weight part of mixed polyol components, More preferably, it is 10-15 weight part. Moreover, metal compounds, such as antimony trioxide and aluminum hydroxide, can also be used.

Other fillers, antioxidants, ultraviolet absorbers and the like commonly used as urethane chemistry may be added as necessary.

Hereinafter, examples and comparative examples of the polyurethane foam composition for thermal insulation will be described. Here, PO means propylene oxide, EO means ethylene oxide, SO means styrene oxide BO means butylene oxide.

Comparative Example 1

100 parts by weight of a mixed polyol component having a hydroxyl group (-OH) value of 450 (15% by weight of sucrose polyether polyol, 35% by weight of pentaerythritol + OH, 25% by weight of toluenediamine + PO / EO, ethylenediamine + PO / EO 25% by weight mixed polyol component) and 0.3 parts by weight of water and 5 parts by weight of hydrochlorofluorocarbon (HCFC-141b) were used as a blowing agent based on 100 parts by weight of mixed polyol. In addition, 117 parts by weight of polymeric MDI having an isocyanate group (NCO) content of 25 was used based on 100 parts by weight of the mixed polyol.

Comparative Example 2

All other conditions were the same as in Comparative Example 1, and 6 parts by weight of the blowing agent was used based on 100 parts by weight of mixed polyol alone. In addition, 125 parts by weight of polymeric MDI having an isocyanate group (NCO) content of 25 was used based on 100 parts by weight of the mixed polyol.

Comparative Example 3

100 parts by weight of a mixed polyol component having a hydroxyl group (-OH) value of 450 (10% by weight of sucrose polyether polyol, 45% by weight of pentaerythritol + OH, 25% by weight of toluenediamine + PO / EO, ethylenediamine + PO 3 parts by weight of water and 15 parts by weight of hydrochlorofluorocarbon (HCFC-141b) were used as a foaming agent.

In addition, 125 parts by weight of polymeric MDI having an isocyanate group (NCO) content of 35 was used based on 100 parts by weight of the mixed polyol.

Comparative Example 4

The conditions different from those of Comparative Example 3 were all the same, and in the blowing agent, 1 part by weight of water and 10 parts by weight of hydrochlorofluorocarbon (HCFC-141b) were used based on 100 parts by weight of the mixed polyol. In addition, 146 parts by weight of polymer MDI having an isocyanate group (NCO) content of 35 was used based on 100 parts by weight of the mixed polyol.

Example 1

100 parts by weight of the mixed polyol component having a hydroxyl group (-OH) value of 450 (40% by weight of polyester polyol, 20% by weight of sucrose polyether polyol, 10% by weight of glycol polyether polyol, 17% by weight of Mannich base polyether polyol) %, A mixed polyol component consisting of 10% by weight of bisphenol A polyether polyol and 3% by weight of a crosslinking agent), and 0.5 parts by weight of water and 30 parts by weight of hydrochlorofluorocarbon (HCFC-141b) based on 100 parts by weight of mixed polyol as a blowing agent. It was. Herein, the modified diphenylmethane diisocyanate having a functional group of 2 and an isocyanate group (NCO) content of 30% and the proportion of 2,4-isomer is 45% by weight and the functional group of 3, an isocyanate group (NCO) content of% 167 parts by weight of a mixed isocyanate obtained by mixing a polymer 4,4-diphenylmethane diisocyanate having a viscosity of 28 and a viscosity of 350 centipoise (CPS) was used based on 100 parts by weight of the mixed polyol.

Example 2

100 parts by weight of a mixed polyol component having a hydroxyl group (-OH) value of 550 (15% by weight of polyester polyol, 40% by weight of sucrose polyether polyol, 20% by weight of glycol polyether polyol, 15% by weight of Mannich base polyether polyol) %, A mixed polyol component consisting of 10% by weight of bisphenol a polyether polyol) and 5 parts by weight of water were used with respect to 100 parts by weight of the mixed polyol as a blowing agent. Herein, the modified diphenylmethane diisocyanate having a functional group of 2 and an isocyanate group (NCO) content of 35% and the proportion of 2,4-isomer is 60% by weight, and the functional group of 3, an isocyanate group (NCO) content of% 173 parts by weight of a mixed isocyanate obtained by mixing a polymer 4,4-diphenylmethane diisocyanate having a viscosity of 33 and a viscosity of 450 centipoise (CPS) was used based on 100 parts by weight of the mixed polyol.

Example 3

100 parts by weight of a mixed polyol component having a hydroxyl group (-OH) value of 650 (30% by weight polyester polyol, 30% by weight sucrose polyether polyol, 20% by weight glycol polyether polyol, 10% by weight of Mannich base polyether polyol) %, A mixed polyol component consisting of 10% by weight of bisphenol a polyether polyol), and 1 part by weight of water and 20 parts by weight of hydrochlorofluorocarbon (HCFC-141b) were used with respect to 100 parts by weight of the mixed polyol as a blowing agent. Here, the modified diphenylmethane diisocyanate having 2% of functional groups and 40% of isocyanate groups (NCO) and 80% by weight of 2,4-isomer and 3% of isocyanate groups (NCO) with functional groups 168 parts by weight of a mixed isocyanate obtained by mixing a polymer 4,4-diphenylmethane diisocyanate having a viscosity of 35 and a viscosity of 650 centipoise (CPS) with respect to 100 parts by weight of the mixed polyol.

Example 4

100 parts by weight of a mixed polyol component having a hydroxy group (-OH) value of 650 (10% by weight polyester polyol, 50% by weight sucrose polyether polyol, 10% by weight glycol polyether polyol, 17% by weight of Mannich base polyether polyol) %, A mixed polyol component consisting of 10% by weight of bisphenol A polyether polyol and 3% by weight of a crosslinking agent) and 2 parts by weight of water and 10 parts by weight of hydrochlorofluorocarbon (HCFC-141b) based on 100 parts by weight of mixed polyol as a blowing agent. It was. Here, the modified diphenylmethane diisocyanate having 2% of functional groups and 40% of isocyanate groups (NCO) and 80% by weight of 2,4-isomer and 3% of isocyanate groups (NCO) with functional groups 175 parts by weight of a mixed isocyanate obtained by mixing a polymer 4,4-diphenylmethane diisocyanate having a viscosity of 35 and a viscosity of 700 centipoise (CPS) with respect to 100 parts by weight of the mixed polyol.

The component contents of the Comparative Example and Example are shown in Table 1.

In addition, the performance of the polyurethane foam produced through the comparative examples and examples are summarized in Table 2. The "physical" physical properties indicated in each section for performance comparison in Table 2 were measured as described below.

First, the free foam density is the foam density (kg / ㎥) of the foam injected and injected into an open box made of plywood having an internal dimension of 200 × 200 × 190 mm, and the product density is the foam density of the actual produced product (kg / ㎥). , Thermal conductivity is the result of measurement (according to KS L 9016) using a laser conductivity measuring instrument (Model No. MA01906).

In addition, compressive strength was measured using a universal testing machine of hardness precision (according to ASTM D-1621), tensile strength was measured using a universal testing machine of hardness precision (according to ASTM D-1623). Adhesion was measured using a bonding force tester from Bukki Corp. (according to DS 2178), and independent foam ratio was determined according to ASTM D-2856, absorbency: based on EN-253, flame retardant: according to KS M 3809 Was measured.

TABLE 1

division ingredient Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example One Example 2 Example 3 Example 4 Polyol Sorbitol (or sucrose) 15 10 5 20 20 40 30 50 Pentaerythritol 35 45 50 40 - - - - Toluenediamine 25 25 25 15 - - - - Ethylenediamine 25 20 20 20 - - - - Aromatic esters - - - - 40 15 30 10 Glycol - - - - 10 20 20 10 Mannich base - - - - 17 15 10 17 Bisphenol A - - - - 10 10 10 10 Crosslinking agent - - - - 3 - - 3 blowing agent 141b 5 - 15 10 30 - 20 10 water 0.3 6 3 One 0.5 5 One 2 Surfactants 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 catalyst 0.8 0.7 1.2 1.1 0.5 0.4 0.5 0.3 Flame retardant 10 10 10 10 10 10 10 10 Polymeric MDI 117 125 137 146 - - - Mixed MDI - - - - 167 173 168 175

TABLE 2

division ingredient Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Example One Example 2 Example 3 Example 4 Foam property Free density (kg / ㎥) 49 42 43 51 56 55 54 58 Product density (kg / ㎥) 54 47 49 57 66 62 63 65 Thermal Conductivity (W / mK) 0.0261 0.0266 0.0259 0.0235 0.0232 0.0242 0.0229 0.0223 Compressive strength (MPa) 0.302 0.223 0.224 0.315 0.471 0.476 0.423 0.515 Flexural Strength (MPa) 0.522 0.424 0.507 0.546 0.943 0.714 0.806 1.159 Shear strength (MPa) 0.198 0.192 0.182 0.202 0.319 0.267 0.273 0.373 Independent Bubble Rate (%) 92 91 92 93 96 93 94 95 Absorption rate (%) 6 7 6 8 3 6 5 3 Adhesive force (MPa) 0.11 0.10 0.14 0.13 0.26 0.24 0.29 0.30 Flame retardant (Combustion distance: mm Burning time: sec) 58 83 57 78 59 71 56 75 47 65 41 79 45 68 42 73

As described above, the polyurethane foam obtained by the present invention has a density of 50 kg / m 3 or more, a thermal conductivity of 0.0256 W / mK or less, an independent bubble ratio of 90% or more, a compressive strength and a bending strength of 0.3 MPa or more, and a shear strength of room temperature. Has a characteristic of 0.25MPa or more. In particular, the inner surface (inner tube) adhesive force for confirming the adhesive strength with the adherend should be a value of 0.2MPa or more, because it is an indicator for determining the life of the insulation, it is only satisfied in Examples 1 to 4 as described above, flame retardancy Self-extinguishing according to KS M 3809.

Looking at the experimental results of Table 2, Comparative Examples 1 to 4 is a result of foaming a polyurethane foam composition having a composition and content of a polyol different from the present invention in a mold at a high temperature. Comparative Examples 1 to 4 had satisfactory results in terms of product density of 54 to 57 kg / m 3, but have high thermal conductivity, which is problematic in thermal insulation performance. The mechanical properties are remarkably poor in shear strength and inner surface (tube) adhesion, so It can be seen that foaming is inadequate. In addition, when the type and amount of the blowing agent is changed, the required physical properties such as thermal conductivity are significantly lower in the comparative examples than in the examples, which is not suitable as the polyurethane foam for high temperature foaming.

On the other hand, in the case of Examples 1 to 4, it can be seen that the measurement of the thermal conductivity and physical strength has excellent properties in general despite foaming at a high temperature. For example, the thermal conductivity not only satisfies the requirements of 0.0232 MPa and 0.0229 MPa, but also shows that the compressive and flexural strength, the shear strength, and the inner surface (pipe) adhesion also exhibit excellent performances satisfying the specifications.

In addition, the polyurethane foams of the invention are produced by injection method. Unlike the slabstock method or the spray method, the injection method is to foam a mixture of the polyurethane composition in a predetermined ratio on the inner surface of a mold having a certain shape. Since the foam is formed with a lot of external resistance, the internal structure of the foam becomes uniform. As it is difficult, like the polyurethane foam of the present invention, polyol and isocyanate should be mixed with the optimum composition and content through several experiments.

Polyurethane foam produced according to the present invention, even when the surface temperature is a high temperature of 80 to 120 ℃ to minimize the influence of the external resistance and the internal temperature and fill the mold tightly, the cured foam is the temperature of the heat medium inside In the state of 100 to 120 ℃ can maintain the insulation performance for at least 30 years.

Hereinafter, an embodiment of a method for preparing a polyurethane foam composition for pipe insulation according to the present invention will be described with reference to FIG. 1.

Polyurethane foam composition production method for pipe insulation basically comprises a first mixing step (S10), a second mixing step (S20), a reaction step (S30).

First, the first mixing step 10 is a Mannich base obtained by adding 10 to 50% by weight of a polyester polyol polymerized with glycol to an aromatic high functional polyester polyol, and a propylene oxide and ethylene oxide to a Mannich Base. 10 to 30% by weight of polyether polyol, 20 to 50% by weight of sucrose polyether polyol obtained by adding propylene oxide and butylene oxide to sucrose or sorbitol, glycol obtained by adding styrene oxide and butylene oxide to glycol 10-30% by weight of polyether polyol and 10-30% by weight of bisphenol-A polyether polyol obtained by adding styrene oxide and butylene oxide to bisphenol A were mixed with a mixed polyol, a catalyst, a foaming agent and a surfactant. Manufacturing step.

Here, the mixed polyol is most preferably a hydroxyl group (-OH) value of 350 to 650. If the hydroxyl group (-OH) value of the mixed polyol is less than 350, the formation reaction and crosslinking reaction may not occur, resulting in poor dimensional stability and mechanical strength of the product.If the hydroxyl group (-OH) value is over 650, the overall physical property value becomes weak. Since the adhesive strength is lowered, the hydroxyl group (-OH) value out of the above-mentioned proper range becomes a cause of product defects and there is a problem that the productivity is lowered.

In addition, the catalyst in the first mixing step (S10) will be examined.

Catalysts used in the present invention are typical catalysts that can be used to obtain polyurethane foams, for example triethylamine, tripropylamine, triisopropanolamine, tributylamine, trioctylamine, hexadecyldimethylamine, tris ( 3-dimethylamino) propylhexahydrotriamine, N-methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, monoethanolamine, diethanolamine, dimethylethanolamine, triethanolamine, N-methyldiethanol Amines, N, N-dimethylethanolamine, diethylenetriamine, N, N, N ', N'-tetramethylbutanediamine, N, N, N', N'-tetramethyl-1,3-butanediamine, N, N, N ', N'-tetraethylhexamethylenediamine, bis [2- (N, N-dimethylamino) ethyl] ether, N, N'-dimethylbenzylamine, N, N-dimethylcyclohexylamine, N, N, N ', N', n'-pentamethyldiethylenetriamine, triethylenediamine, formic acid and other salts of triethylenediamine, of first and second amines Mino groups, oxyalkylene adducts, azacyclic compounds such as N, N-dialkyl piperazines, β-aminocarbonyl catalysts of various N, N ', N'-trialkylaminoalkylhexahydrotriazines, and the like. Is an amine catalyst.

It is preferable to use these catalysts individually or in mixture, and the usage-amount is 0.05-1.5 weight part with respect to 100 weight part of said mixed polyol components, More preferably, 0.1-0.9 weight part is suitable. Here, when the amount of the catalyst is less than 0.05 parts by weight, in the reaction for the present invention, the rigid polyurethane foam production reaction is incomplete, so that the physical properties can be reduced, the role of the catalyst can not be expected, if the amount exceeds 1.5 parts by weight excessively This activity is difficult to control, and there is a problem that carbonization (Scorch) or sponge phenomenon may occur.

In addition, the foaming agent in the first mixing step (S10) will be examined.

According to the present invention, the blowing agent uses hydrochlorofluorocarbon (HCFC) as water (H ₂ O) or fluorocarbon blowing agent. When water (H ₂ O) is used alone, 1 to 5 parts by weight based on 100 parts by weight of the mixed polyol component is used, and water (H ₂ O) and hydrochlorinated fluorocarbon (HCFC) are mixed when water ( It is preferable to use 0.5 to 2 parts by weight of H ₂ O) and 10 to 30 parts by weight of hydrochlorofluorocarbon (HCFC). In this case, when water (H ₂ O) is used alone, when water (H ₂ O) is used in an amount less than 1 part by weight, the desired density does not come out. When it exceeds 5 parts by weight, the insulation of the polyurethane foam is inferior and the foam is broken. The adhesive force with the face material is also weakened.

In addition, the surfactant in the first mixing step (S10) will be examined.

According to the present invention, the surfactant uses a polysiloxane ether as an organosilicon compound. The amount of the surfactant used at this time is preferably 1 to 4 parts by weight, more preferably 1.5 to 3 parts by weight based on 100 parts by weight of the mixed polyol component. When the amount of the surfactant is less than 1 part by weight, the diffusion of gas by foaming cannot be prevented. When the amount of the surfactant is more than 4 parts by weight, the surface tension of the reactants is lowered to prevent the collapse of the closed cell structure. The effect of the surfactant is almost eliminated. In addition, the viscosity of the surfactant is 100 to 2000 centipoise (cps), the molecular weight is preferably 3,000 to 7,000 g / mol. Viscosity and molecular weight in the above range is suitable for maximizing the suitability and reactivity between materials in the reaction of the surfactant with other raw materials.

The second mixing step (S20) is a step of preparing mixed isocyanate by mixing modified diphenylmethane diisocyanate with polymeric 4,4-diphenylmethane diisocyanate.

In the mixed isocyanate, the modified diphenylmethane diisocyanate (MDI) has a functional group of 1.8 to 2.5, an isocyanate group (NCO) content% of 30 to 40, and a ratio of 2,4-isomer of 40 to 80% by weight. The polymeric 4,4-diphenylmethane diisocyanate has a functional group of 2.6 to 2.9, an isocyanate group (NCO) content of 28 to 35, and a viscosity of 350 to 700 centipoise (CPS). use.

For this reason, the modified diphenylmethane diisocyanate (MDI) component enhances adhesion to the adherend, but when the content of the isocyanate group (NCO) of the modified diphenylmethane diisocyanate (MDI) component is less than 30%, It is not expected to improve, and if it exceeds 40%, the adhesion, compression, and tensile strength will be lowered. In the case of 4,4-diphenylmethane diisocyanate used together, the dimension of the isocyanate group (NCO) content is less than 28% This is because if the stability falls and exceeds 35%, the fluidity is lowered.

In addition, the reaction ratio of the mixed isocyanate component and the mixed polyol component is preferably NCO / OH of 1.3 to 3.5, more preferably a weight ratio of the isocyanate group (-NCO) of the mixed isocyanate component and the hydroxyl group (-OH) of the mixed polyol, more preferably. Is preferably from 1.4 to 2.5. When the ratio of NCO / OH is less than 1.3, the polyurethane foam is weakened, so that the dimensional stability is lowered and the mechanical strength is decreased. When the ratio of NCO / 0H is greater than 3.5, the polyurethane foam is broken.

When the NCO / OH ratio is 1.3 to 3.5, the isocyanate is present in excess. In this case, the remaining isocyanate forms allophanate and biuret through addition reaction due to the completion of polyurethane foam formation. Physical properties are improved. The isocyanate at high temperature forms strong isocyanurate bond through its own reaction, which is stronger than general urethane bond, so it is not easily broken. Chemical stability and thermal stability are improved, and it is heat resistant and flame retardant. It is excellent and can maintain low thermal conductivity. Therefore, when the blending ratio of the mixed polyol component and the mixed isocyanate component to be reacted is outside the above range, the object of the present invention cannot be achieved.

Reaction step (S30) is a step of reacting the reaction solution and the mixed isocyanate. The reaction step is any one of low pressure (S31) to react by mechanically mixing at a pressure of 1 to 10 bar or high pressure (S32) to react by colliding the reaction solution and the mixed isocyanate at a pressure of 50 to 200 bar. The reaction proceeds.

It has been described in detail above with reference to preferred embodiments of the present invention. However, the scope of the present invention is not limited to the above embodiments, but may be embodied in various forms of embodiments within the appended claims. Without departing from the gist of the invention as claimed in the claims, any person skilled in the art to which the invention pertains is considered to be within the scope of the claims of the invention to the various possible modifications possible.

1 is a flow chart sequentially showing an embodiment of a method for producing a polyurethane foam composition for pipe insulation according to the present invention.

Claims (16)

In the polyurethane foam composition for pipe insulation containing a mixed polyol, mixed isocyanate, catalyst, blowing agent, surfactant, The mixed polyol is (1) polyester polyols obtained by polymerizing glycols to aromatic high functional polyester polyols; (2) Mannich base polyether polyols obtained by adding propylene oxide and ethylene oxide to Mannich Base; (3) Sucrose polyether polyol obtained by adding propylene oxide and butylene oxide to sucrose or sorbitol; (4) glycol polyether polyols obtained by adding styrene oxide and butylene oxide to glycol; (5) a bisphenol a polyether polyol obtained by adding styrene oxide and butylene oxide to bisphenol a; The mixed isocyanate is a polyurethane foam composition for pipe insulation, characterized in that it comprises a modified diphenylmethane diisocyanate and polymeric 4,4-diphenylmethane diisocyanate. The method of claim 1, The mixed polyol is 10 to 50% by weight of the polyester polyol; 10 to 30% by weight of the Mannich base polyether polyol; 20 to 50% by weight of the sucrose polyether polyol; 10 to 30% by weight of the glycol polyether polyol; 10 to 30% by weight of the bisphenol-A polyether polyol; Polyurethane foam composition for pipe insulation characterized in that it comprises a. The method according to claim 1 or 2, The mixed isocyanate is the modified diphenylmethane diisocyanate and functional group having a functional group of 1.8 to 2.5, an isocyanate group (NCO) content of 30 to 40, and a ratio of 2,4-isomer of 40 to 80% by weight. To 2.9, an isocyanate group (NCO) content of 28 to 35, the viscosity of the pipe is characterized in that it comprises the polymer 4,4-diphenylmethane diisocyanate of 350 to 700 centipoise (CPS) Polyurethane foam composition. The method according to claim 1 or 2, Polyurethane foam composition for pipe insulation, characterized in that the weight ratio of the isocyanate group (NCO) of the mixed isocyanate to the hydroxyl group (-OH) of the mixed polyol is 1.3 to 3.5. The method according to claim 1 or 2, The mixed polyol is a polyurethane foam composition for pipe insulation, characterized in that the hydroxyl group (-OH) value is 350 to 650. The method according to claim 1 or 2, The catalyst is an amine catalyst, the polyurethane foam composition for pipe insulation, characterized in that it comprises 0.05 to 1.5 parts by weight based on 100 parts by weight of the mixed polyol. The method according to claim 1 or 2, The blowing agent is water (H ₂ O) based on 100 parts by weight of the mixed polyol of 1 to 5 parts by weight made or water (H ₂ O) for the mixed polyol 100 parts by weight of 0.5 to 2 parts by weight of the hydrogenated chlorofluorocarbons (HCFC Polyurethane foam composition for pipe insulation comprising 10 to 30 parts by weight. The method according to claim 1 or 2, The surfactant is a polysiloxane ether having a molecular weight of 3000 to 7000 g / mol and a viscosity of 100 to 2000 centipoise (CPS), and is 1 to 4 parts by weight based on 100 parts by weight of the mixed polyol. . In the method for producing a polyurethane foam composition for pipe insulation, 10 to 50% by weight of a polyester polyol obtained by polymerizing glycol to an aromatic high functional polyester polyol, 10 to 30% by weight of Mannich base polyether polyol obtained by adding propylene oxide and ethylene oxide to Mannich Base, and 20-50 wt% of sucrose polyether polyol obtained by adding propylene oxide and butylene oxide to loose or sorbitol, 10-30 wt% of glycol polyether polyol obtained by adding styrene oxide and butylene oxide to glycol, bisphenol A first mixing step of preparing a reaction solution by mixing a mixed polyol, a catalyst, a blowing agent, and a surfactant, in which 10 to 30% by weight of a bisphenol A polyether polyol obtained by adding styrene oxide and butylene oxide is mixed; A second mixing step of preparing a mixed isocyanate by mixing a modified diphenylmethane diisocyanate and a polymeric 4,4-diphenylmethane diisocyanate; Reaction step of reacting the reaction solution and the mixed isocyanate; Method of producing a polyurethane foam composition for pipe insulation, characterized in that it comprises a. The method of claim 9, The reaction step may be any one of a low pressure type to react by mechanically mixing at a pressure of 1 to 10 bar or a high pressure type to react by reacting the reaction solution and the mixed isocyanate at a pressure of 50 to 200 bar. Method for producing a polyurethane foam composition for thermal insulation. The method according to claim 9 or 10, The mixed isocyanate is the modified diphenylmethane diisocyanate and functional group having a functional group of 1.8 to 2.5, an isocyanate group (NCO) content of 30 to 40, and a ratio of 2,4-isomer of 40 to 80% by weight. To 2.9, an isocyanate group (NCO) content of 28 to 35, the viscosity of the pipe is characterized in that it comprises the polymer 4,4-diphenylmethane diisocyanate of 350 to 700 centipoise (CPS) Process for the preparation of polyurethane foam compositions. The method according to claim 9 or 10, The weight ratio of the isocyanate group (NCO) of the mixed isocyanate to the hydroxyl group (-OH) of the mixed polyol is 1.3 to 3.5, and the mixed polyol has a hydroxyl group (-OH) value of 350 to 650 for pipe insulation Process for the preparation of polyurethane foam compositions. The method according to claim 9 or 10, The catalyst is an amine catalyst, the method of producing a polyurethane foam composition for pipe insulation, characterized in that it comprises 0.05 to 1.5 parts by weight based on 100 parts by weight of the mixed polyol. The method according to claim 9 or 10, The blowing agent is water (H ₂ O) based on 100 parts by weight of the mixed polyol of 1 to 5 parts by weight made or water (H ₂ O) for the mixed polyol 100 parts by weight of 0.5 to 2 parts by weight of the hydrogenated chlorofluorocarbons (HCFC A method for producing a polyurethane foam composition for pipe insulation, comprising 10 to 30 parts by weight. The method according to claim 9 or 10, The surfactant is a polysiloxane ether having a molecular weight of 3000 to 7000 g / mol and a viscosity of 100 to 2000 centipoise (CPS), and is 1 to 4 parts by weight based on 100 parts by weight of the mixed polyol. Manufacturing method. Polyurethane foam for pipe insulation, characterized in that produced by claim 9 or 10.

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