KR101476783B1 - Foamed polyurethane-insulation material in high temperature for heat transporting pipe and its manufacturing method - Google Patents

Abstract

The present invention relates to a high temperature expanded polyurethane insulating material for a heat transfer pipe, and more particularly, to an isocyanate-containing high-temperature expanded polyurethane insulating material comprising 40 to 80 parts by weight of a polyol having 2 or more functional groups per 100 parts by weight of the isocyanate, 0.01 to 1.5 parts by weight of a reaction catalyst, And 1 to 15 parts by weight of an additive are mixed and reacted.
According to the present invention, the polyurethane foam is stably foamed in a high-temperature double-insulated tube without scorch or cracking at a high temperature, and a high-temperature foamed polyurethane insulation material for a heat-transfer pipe excellent in both heat insulation performance and mechanical strength Can be manufactured.

Description

FIELD OF THE INVENTION The present invention relates to a hot-foaming polyurethane heat-insulating material for heat-transferring pipes and a method for manufacturing the same,

The present invention relates to a high-temperature expanded polyurethane insulating material for a heat-transferring pipe and a method of manufacturing the same, and more particularly, to a method of manufacturing a polyurethane foaming material by foaming a polyurethane under high temperature (50 to 100 ° C) Temperature foamed polyolefin for hot water piping which exhibits excellent thermal and mechanical properties as well as thermal and mechanical properties without causing problems such as cracking of foam or cracking due to reaction and damage of foam, And a method for producing the same.

In general, polyurethane foam is an insulating material having the best heat insulation among oil and inorganic heat insulating materials. It is a low temperature insulating material such as a refrigerator, a freezing container, a low temperature warehouse, and a hot water conveying pipe for transferring hot water and steam at 50 to 120 ° C. Double insulated pipes), and so on.

This is because the foamed polyurethane foam is composed of independent bubbles, which is excellent in heat insulation, and can control the amount and type of the foamed raw material to produce foam of desired density.

Most of the currently used rigid polyurethane foams are used by foaming at a temperature of 10 to 40 ° C. Especially, the polyurethane foams used in heat transfer pipes (hereinafter referred to as double insulated pipes) are manufactured at the temperature range of 50 to 120 ° C. (PIPE) which transports the heating medium to the inside of the double insulated pipe of the pipe. The double insulated pipe is a pre-insulated pipe (PIP) used for the heating of large-scale residential complexes such as apartment buildings and for chemical transfer pipes or steam pipes of cogeneration power plants in chemical plants. It is used in a temperature range of 50 ~ 120 ℃ Refers to a tube that prevents the temperature from dropping during transport of the fluid and minimizes thermal expansion and thermal stresses. The double insulated pipe (PIP) can be manufactured by inserting most of piping materials in the factory by productizing it, unlike other thermal insulation methods such as hot insulation after jacking and external protection jacketing, Which can contribute to cost reduction and the like. The double insulated pipe is used to prevent the outside from using the high density polyethylene pipe. Even if it is buried in the ground or underwater, it can prevent most of intrusion of moisture, air, and bacteria without breakage, thus preventing biochemical corrosion and tampering There is an advantage to be able to do.

In this double insulated tube, a heat insulating material (mainly polyurethane foam) is used between the inner tube and the outer tube, and the heat insulating material used prevents the heat leakage due to the temperature difference between the temperature of the fluid flowing inside the inner tube and the temperature outside the outer tube Not only minimizes heat loss, but also functions to cut off some incoming water (water) by transmitting the appearance.

1, an end cap 3 is mounted on both ends of a double insulated tube 1 having an inner tube 1a and an outer tube 1b, A double insulated pipe 1 having a length of 6 to 12 M is manufactured through a method of injecting a foamed liquid into a foaming machine 5 through an injection port 3a formed in a mold 3 to form a product. As shown in FIG. 2, after welding the neighboring inner pipe 1a at the site, the casing 7 previously sandwiched at the time of manufacturing the double insulated pipe 1 is moved around the welded portion to adhere the both ends of the casing to the outer surface, In which a polyurethane foam is foamed. This method is mainly applied to newly installed double heat insulation joints. It is a method to work at 10 ~ 40 ℃, which is the general temperature range in which the inner pipe does not transport the heat medium. However, since the pipe is already in use, The polyurethane can not be used when the temperature of the steel pipe of the double insulated pipe which is flowing reaches 50 ° C to 120 ° C.

The reason for this is that polyurethane manufacturing and manufacturing method used at 10 to 40 ° C is such that when the temperature of the foaming space is higher than 40 ° C, rapid foaming occurs due to high temperature, and excessive foaming, carbonization, sponge phenomenon And it is difficult to control the reactivity appropriately. As a result, vacancies (unfilled) are generated in the foamed object, or cracks are generated in the foam.

Therefore, in order to insulate the high-temperature pipe by the conventional hot insulation method, the temperature must be lowered to the operable temperature of 50 to 120 ° C. at 50 to 120 ° C., so that the flow of the heat medium flowing inside must be stopped. This causes not only inconveniences to consumers' lives but also the cost of replacing the existing pipes to shorten the working time. Therefore, even if the temperature of the steel pipe and the foaming space is maintained at an appropriate level, the foam is maintained at a high temperature of 50 to 120 ° C after the foam is formed, thereby maintaining the heat insulating performance. The mechanical strength is excellent and excellent adhesion to the steel pipe and the exterior is maintained Development of polyurethane foam (FOAM) for high temperature foaming has been demanded.

In order to meet the above-mentioned demand, the present invention relates to a polyol having enhanced heat resistance in combination with another polyol and an additive in combination with a polymeric 4,4-diphenylmethane diisocyanate to enhance heat resistance And the reactivity is controlled and foamed so as not to react abruptly even at a high temperature of the pipe which is the object of foaming through the combination of the trimerization catalyst and the urethane catalyst. Thus, the polyurethane foam has excellent heat insulation, excellent strength, Which is excellent in adhesion to various face plates, and a method for producing the same.

According to an aspect of the present invention,

A polymeric isocyanate using polymeric 4,4-diphenylmethane diisocyanate having an NCO% of 30 to 33, a functional group of 2.6 to 2.9 and a viscosity of 100 to 400 centipoise (cps) at 25 占 폚; 40 to 80 parts by weight of a mixed polyol having 2 or more functional groups per 100 parts by weight of the polymeric isocyanate; Acid-blocking the trimerization catalyst to inhibit the initial reaction at 50-120 ° C and to promote the end cure reaction to improve the integrity density (bonding to solidify) 0.01 to 1.5 parts by weight of a reaction catalyst relative to 100 parts by weight of the mixed polyol to induce the reaction to proceed stably; A hydrofluorocarbon (HFC) blowing agent in which a mixture of water and HFC (Hydrofluorocarbon) -365mfc / 227ea is used alone or a mixture of HFC-365mfc / 227ea mixture and 90-95% by weight of HFC (Hydrofluorocarbon) 5 to 20 parts by weight of a foaming agent relative to 100 parts by weight of a mixed polyol; And 1 to 15 parts by weight of an additive which comprises a surfactant, a flame retardant, a filler, an antioxidant, a stabilizer and a colorant, and which is used singly or in combination of two or more kinds thereof, based on 100 parts by weight of the mixed polyol, The mixed polyol having an average OH value of 300 to 650 mgKOH / g and an NCO / OH ratio of 1.2 to 2.7, which is an equivalence ratio of the isocyanate NCO to the OH equivalent, is mixed and reacted.

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Wherein the mixed polyol comprises 10 to 70 parts by weight of a polyether polyol obtained by adding an alkylene oxide to sucrose or sorbitol, which is an initiator having a functional group of 4 or more per 100 parts by weight of the mixed polyol; 5 to 30 parts by weight of a polyether polyol obtained by combining glycerin or trimethylol propane (TMP) with alpha methyl glucoside per 100 parts by weight of the mixed polyol; 5 to 30 parts by weight of an aromatic polyester polyol relative to 100 parts by weight of the mixed polyol so as to maximize conversion of polyisocyanurate in a polyurethane-polyisocyanurate structure; And polyhydric alcohol 1 having a molecular weight of less than 300 and a molecular weight of 3 or more and having a functional group of 3 or more based on 100 parts by weight of the mixed polyol so as to promote stable foaming by suppressing the occurrence of swelling or deterioration during foaming by increasing cross- To 10 parts by weight.

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Here, the aromatic polyester polyol is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol, and the aromatic polycarboxylic acid is dimethyl terephthalate, phthalic acid, isophthalic acid, and naphthalenedicarboxylic acid, and the polyhydric alcohol is ethylene glycol, diethylene glycol, Propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol and neopentyl glycol, and they are used alone or in combination of two or more, and have an OH value of 200 to 600 mgKOH / g.

Here, the polyhydric alcohol is any one of glycerin, trimethylolpropane, and pentaerythritol.

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Here, the blowing agent is used by mixing 0.1 to 1.0 part by weight of water and 4.9 to 19.0 parts by weight of a HFC (hydrofluorocarbon) blowing agent with respect to 100 parts by weight of the mixed polyol.

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According to another aspect of the present invention,

The method for producing the high temperature expanded polyurethane heat insulating material for a heat pipe according to any one of claims 1 to 4, wherein the polymeric material has a NCO content of 30 to 33, a functional group of 2.6 to 2.9, a viscosity of 100 to 400 centipoise (cps) A polymeric isocyanate preparing step of preparing 4-diphenylmethane diisocyanate; A polymeric isocyanate using polymeric 4,4-diphenylmethane diisocyanate having an NCO% of 30 to 33, a functional group of 2.6 to 2.9 and a viscosity of 100 to 400 centipoise (cps); 40 to 80 parts by weight of a mixed polyol having 2 or more functional groups per 100 parts by weight of the polymeric isocyanate; Acid-blocking the trimerization catalyst to inhibit the initial reaction at 50-120 ° C and promote the end cure reaction to improve the integrity density (solidification) 0.01 to 1.5 parts by weight of a reaction catalyst relative to 100 parts by weight of the mixed polyol so as to induce a stable reaction at a reaction temperature of & A hydrofluorocarbon (HFC) blowing agent in which a mixture of water and HFC (Hydrofluorocarbon) -365mfc / 227ea is used alone or a mixture of HFC-365mfc / 227ea and 90-95% by weight of HFC (Hydrofluorocarbon) 5 to 20 parts by weight of a foaming agent relative to 100 parts by weight of a mixed polyol; And 1 to 15 parts by weight of an additive which comprises a surfactant, a flame retardant, a filler, an antioxidant, a stabilizer and a colorant, and which is used singly or in combination of two or more kinds thereof, based on 100 parts by weight of the mixed polyol, Preparing a mixed polyol composition wherein the mixed polyol has an average OH value of 300 to 650 mgKOH / g and an equivalent ratio of isocyanate NCO to OH equivalent of NCO / OH of 1.2 to 2.7; And an injected foaming reaction step in which the mixed polyol composition solution with the polymeric isocyanate is injected into the outer side of a double insulated tube and mechanically mixed at a pressure of 20 to 60 kgf / cm 2.

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According to the high-temperature expanded polyurethane insulating material for a heat-transfer pipe of the present invention having the above-described structure and the method for producing the same, the polyurethane foam can be obtained at a high temperature without scorch, overblowing, VOID, density irregularity, It is possible to manufacture a heat transfer pipe heat insulating material for high temperature foaming which is stably foamed in the double insulated tube of the present invention and has excellent both the heat insulating performance and the mechanical strength.

1 is a view for explaining a manufacturing process of a conventional double insulated tube.
FIG. 2 is a view for explaining a process of inserting a built-in double insulated pipe at a site connection.
3 is a process diagram for explaining a method of manufacturing a high-temperature expanded polyurethane insulating material for a heat-transferring pipe according to the present invention.
FIGS. 4 and 5 are photographs of specimens produced according to the comparative example of the present invention and having undergone filling, over-foaming and cracking.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a high temperature expanded polyurethane insulating material for a heat transfer pipe according to the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

The hot-foaming polyurethane insulating material for hot-water delivery pipes according to the present invention comprises a polyol having a high functionality having at least two hydroxyl groups, a polymeric polyisocyanate having at least two isocyanate groups, a foaming agent, The rigid polyurethane foam having excellent durability as well as foaming and adhesion to the hot-water pipe for high-temperature heat pipe can be manufactured while maintaining the excellent heat insulating property as the general rigid urethane foam.

More particularly, the present invention relates to a process for producing a polyol, which comprises reacting polymeric isocyanate and polymeric isocyanate in an amount of 40 to 80 parts by weight with respect to 100 parts by weight of a mixed polyol having 2 or more functional groups and 0.01 to 1.5 parts by weight of a reaction catalyst, 5 to 20 parts by weight of a blowing agent and 1 to 15 parts by weight of an additive to 100 parts by weight of a mixed polyol are mixed and reacted with each other.

Here, the mixed polyol includes sucrose or sorbitol, which is an initiator having a functional group of 4 or more, polyether polyol having enhanced heat resistance characteristics by combining alpha methyl glucoside and glycerin or trimethylol propane (TMP); Aromatic polyester polyols maximizing the conversion of polyisocyanurate in a polyurethane-polyisocyanurate structure; And polyhydric alcohols having a molecular weight of less than 300 g / mol and a molecular weight of 3 or more and having a functional group of 3 or more so as to promote physical foaming while suppressing the occurrence of swelling or deterioration during foaming by increasing cross-linking density.

10 to 70 parts by weight of a polyether polyol obtained by adding an alkylene oxide to sucrose or sorbitol, which is an initiator having a functional group of 4 or more per 100 parts by weight of the mixed polyol, and 100 to 10 parts by weight of a polyol, And 5 to 30 parts by weight of a polyether polyol obtained by combining glycerin or trimethylol propane (TMP). At this time, if the polyether polyol added with sucrose or sorbitol is less than 10 parts by weight, the strength and dimensional stability are weakened. If the amount is 70 parts by weight or more, the flowability of the mixed polyol composition is lowered, When the amount of the polyether polyol combined with glycerin or trimethylol propane (TMP) is less than 5 parts by weight, the effect of increasing the fluidity and adhesion is too small. If the amount of the polyether polyol is more than 30 parts by weight, And dimensional stability is poor.

The aromatic polyester polyol may further contain 5 to 30 parts by weight of aromatic polyester polyol relative to 100 parts by weight of the mixed polyol so as to maximize the conversion of polyisocyanurate in the polyurethane-polyisocyanurate structure If the amount is less than 5 parts by weight, the effect of improving the heat resistance and oil resistance is deteriorated. If the amount is more than 30 parts by weight, the amount of trimerization is increased and the crumbling is increased.

At this time, the aromatic polyester polyol is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol. As the aromatic polycarboxylic acid, dimethyl terephthalate, phthalic acid, isophthalic acid, and naphthalenedicarboxylic acid are used. Polyhydric alcohols include ethylene glycol, diethylene glycol, propylene glycol, Glycols such as 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol and neopentyl glycol. These are used alone or in combination of two or more, and the OH value is 200 to 600 mgKOH / g.

The polyhydric alcohol has a low molecular weight of less than 300 g / mol and has a molecular weight of less than 300 g / mol based on 100 parts by weight of the mixed polyol so as to promote physical fluidity and increase cross-linking density to suppress occurrence of swelling or deterioration during foaming, 1 to 10 parts by weight of a polyhydric alcohol having 3 or more is mixed. When the amount is less than 1 part by weight, it is difficult to expect an effect of increasing physical fluidity and a function of suppressing deterioration. More than 10 parts by weight of the polyhydric alcohol has an excessively high crosslinking density, And preferably 3 to 7 parts by weight are mixed.

In this regard, the polyhydric alcohol refers to an oligomer having a molecular weight of about 500 or higher in the polyurethane technical field, but is used in the present invention to include a low molecular weight polyhydric alcohol. Polyhydric alcohols are considered to be particularly effective for improving swelling and deterioration during the foaming process by increasing the crosslinking density. Examples of the polyhydric alcohol include those having a molecular weight of less than 300 g / mol, such as glycerin, trimethylol propane, and pentaerythritol, and having a molecular weight of 3 or more and having a functional group of 3 or more.

On the other hand, the reaction catalyst is mixed in an amount of 0.01 to 1.5 parts by weight based on 100 parts by weight of the mixed polyol. When the amount is less than 0.01 part by weight, the hard polyurethane foam-forming reaction is incomplete and physical properties are lowered. , And when the amount is larger than 1.5 parts by weight, the reaction becomes excessively rapid, so that a scorch or a sponge phenomenon may occur (carbonization or sponge occurs more strongly due to the high heat of the internal heat medium) Mixed.

At this time, the reaction catalyst is applied with a trimerization catalyst or an amine catalyst, preferably acid-blocking the trimerization catalyst to inhibit the initial reaction at a high temperature and promote the end cure reaction The consolidation density (bonding to solidify) was improved and the reaction at high temperature was induced to proceed stably. Here, the termination catalyst is a catalyst for promoting the reaction, in which three aliphatic or aromatic isocyanates react to form isocyanurate (trimerization reaction), and some tertiary Amines or some organometallic catalysts are used. Examples of the trimerization catalyst include potassium acetate, dipropylene glycol, monoethylene glycol, benzyldimethylamine, 1,3,5- (tris (3-dimethylamino) propyl) -hexahydro-s-triazine having a triazine structure or a quaternary ammonium salt. , Dipropylene glycol, 2,4,6-dimethylaminomethyl phenol, bis- (2-dimethylaminoethyl) ethe, N, N'-trimethyl-N'- (dimethylamino) propyl) -N, N-dimethyl-1,3-propanediamine, [2,4,6-Tris (dimethylaminomethyl) phenol]), N, N, N ' Triethylenediamine, dimethylene aminopropylamine, N-methylmorpholine, N-ethylmorpholine, dimethylpiperazine, and the like.

The blowing agent is mixed in an amount of 5 to 20 parts by weight based on 100 parts by weight of the mixed polyol, and 0.1 to 1.0 part by weight of water and 4.9 to 19.0 parts by weight of the HFC (hydrofluorocarbon) blowing agent are added to 100 parts by weight of the mixed polyol. Here, when water is used alone as a blowing agent, the water foam is broken and the adhesive force to the face material is weakened. As a result, the heat insulating performance of the polyurethane foam is deteriorated and the desired heat insulating performance can not be exhibited.

At this time, as the foaming agent, HFC (Hydrofluorocarbon) type is used as water or fluorocarbon type foaming agent. Generally, foaming agents used in polyurethane foams are water, carboxylic acids, fluorocarbon based foaming agents, or inert gases such as carbon dioxide and air.

A polyol composition for rigid polyurethane foam and a method for producing the rigid polyurethane foam, wherein a mixture of HFC-365mfc / 227ea as a foaming agent is used alone or in combination with HFC-245fa and its compatibility is improved. Wherein the content is a polyol composition for a rigid polyurethane foam containing a polyol compound, a foaming agent, a foaming agent, and a catalyst, which is mixed with an isocyanate component containing a polyisocyanate compound to form a hard polyurethane foam by foaming and curing, 1,1,1,3,3-pentafluoropropane (HFC-245fa) which is 1,1,1,3,3-pentafluorobutane (HFC-365mfc) alone, and water as a chemical foaming agent By weight.

Further, the additive is mixed in an amount of 1 to 15 parts by weight based on 100 parts by weight of the mixed polyol, and the surfactant, the flame retardant, the filler, the antioxidant, the stabilizer and the colorant are used alone or in combination of two or more .

In addition, as the surfactant used in the present invention, polysiloxane ether is used as an organosilicon compound generally used in the production of polyurethane foam. The amount of the surfactant used is preferably 1.0 to 4.0 parts by weight, more preferably 1.2 to 3.0 parts by weight, based on 100 parts by weight of the mixed polyol. If the amount of the surfactant is less than 1.0 part by weight, diffusion of gas by foaming can not be prevented and uniform formation of cells becomes difficult. When the amount of the surfactant is more than 4.0 parts by weight, the surface tension of the reactant is lowered, The difference in effect of preventing collapse is not large. The viscosity of the surfactant at 25 캜 is generally from 100 to 2000 cst, and the molecular weight is preferably from 2,000 to 9,000 g / mol. The viscosity and the molecular weight should be set as above considering the suitability and reactivity between the materials when reacting the surfactant with other raw materials.

In order to enhance the flame retardancy of the rigid polyurethane foam of the present invention, a flame retardant may be added. Examples of the flame retardant used in the present invention include tris (2-fluoroethyl) phosphate, tris (chloropropyl) phosphate and tris (dipropropyl) phosphate. When a flame retardant is used, the amount thereof is preferably 5 to 20 parts by weight, more preferably 10 to 15 parts by weight, per 100 parts by weight of the mixed polyol. Further, metal compounds such as antimony trioxide and aluminum hydroxide can be used.

Other fillers commonly used in urethane chemistry, antioxidants, stabilizers such as ultraviolet absorbers, and coloring agents can be added as needed.

On the other hand, the average 0H value of the mixed polyol composition is preferably from 300 to 650 mgKOH / g to produce a stable rigid polyurethane foam. When the average OH value of the mixed polyol composition is less than 300 mgKOH / g, formation reaction and crosslinking reaction do not occur and the dimensional stability and mechanical strength of the product deteriorate. When the average OH value exceeds 650 mgKOH / g, the overall property value becomes weak, And the adhesive strength is lowered. Therefore, the average OH value deviating from the above-mentioned appropriate range is a cause of the defective product, and the productivity is lowered.

Also, the polymeric isocyanate component to be reacted with the mixed polyol composition is a mixture of 4,4-diphenylmethane diisocyanate having an NCO% of 30 to 33, a functional group of 2.6 to 2.9 and a viscosity of 100 to 400 centipoise (cps) Lt; / RTI > In the case of diphenylmethane diisocyanate, the dimensional stability is deteriorated when the NCO% is 30 or less, and the fluidity is lowered when the NCO% is 33 or more. In addition, the reaction ratio of the polymeric isocyanate component to the mixed polyol component is preferably 1.2 to 2.7, more preferably 1.4 to 2.5, as NCO / OH, which is the NCO equivalent ratio of the mixed isocyanate component to the OH equivalent. When the ratio of NCO / OH is less than 1.2, the polyurethane foam is weakened and the dimensional stability is lowered and the mechanical strength is decreased. When the ratio of NCO / OH is more than 2.7, the control of reactivity becomes difficult and blemish of foam occurs. When the NCO / OH ratio is more than 1.3 and not more than 2.7, excess polymeric isocyanate is present. In this case, after the formation of the polyurethane foam is completed, the remaining polymeric isocyanate forms allophanate, An additional crosslinking reaction improves the physical properties.

In addition, the polymeric isocyanate at high temperature forms strong isocyanurate linkages through its own reaction, which has stronger bonding force than general urethane bond and is not easily broken, which is excellent in chemical stability and thermal stability, and is excellent in heat resistance and flame retardancy It is possible to maintain a low thermal conductivity.

Therefore, if the mixing ratio of the mixed polyol component and the polymeric isocyanate component to be reacted out of the above range, the object of the present invention can not be achieved.

According to the present invention, a polyurethane foam can be obtained by reacting a blowing agent, a reaction catalyst and other additives with a mixed polyol component and a polymeric isocyanate component having the above-described specific composition as basic raw materials.

Hereinafter, the present invention will be described in more detail with reference to Comparative Examples and Examples.

&Quot; Comparative Examples 1 and 2 "

In Comparative Examples 1 and 2, 100 parts by weight of a polyol component having an average OH value of 300 to 500 mgKOH / g (sorbitol + EO / PO 40 to 50 parts by weight, pentaerythritol + OH 20 to 30 parts by weight, toluene diamine + 10 to 15 parts by weight of HFC-365mfc / 227ea as a blowing agent, 0.1 to 1.0 part by weight of water or 0.8 to 2.5 parts by weight as a foaming agent . For example, in Comparative Example 1, 0.5 parts by weight of water and 15 parts by weight of HFC-365mfc / 227ea were used in order to adjust the density to about 83 kg / m 3. In Comparative Example 2, water was used alone without using HFC-365mfc / 227ea 2.5 parts by weight were used. In Comparative Example 1, 140 parts by weight of polymeric MDI having an average NCO% of 30 to 33 was used, and 147 parts by weight of Comparative Example 2 was used to foam and cure to prepare a polyurethane foam sample. The results are shown in Table 2.

&Quot; Comparative Examples 3 and 4 "

In Comparative Examples 3 and 4, 100 parts by weight of a polyol component having an average OH value of 300 to 500 mgKOH / g (20 to 30 parts by weight of sorbitol + EO / PO, 30 to 40 parts by weight of pentaerythritol + OH, 10 to 20 parts by weight of PO and 15 to 20 parts by weight of ethylenediamine + EO / PO), 0.5 to 1.0 part by weight of water and 10 to 15 parts by weight of HFC-365mfc / 227ea were used as a foaming agent. In Comparative Example 3, 12 parts by weight of HFC-365mfc / 227ea and 0.8 parts by weight of water were used. In Comparative Example 4, 13 parts by weight of HFC-365mfc / 227ea and 0.6 parts by weight of water were used to adjust the density to 86 kg / Respectively. In Comparative Example 3, 159 parts by weight of polymeric MDI having an average NCO% of 30 to 33 was used, and 155 parts by weight of Comparative Example 4 was used to foam and cure to prepare a polyurethane foam sample. The results are shown in Table 2.

&Quot; Example 1 &

100 parts by weight of a mixed polyol component having an OH value of 500 mgKOH / g (70 parts by weight of a sucrose base polyether polyol, 10 parts by weight of an alphamethyl glucoside base polyether polyol, 17 parts by weight of a polyester polyol and 3 parts by weight of a crosslinking agent Polyol component), 0.5 parts by weight of water and 15 parts by weight of HFC-365mfc / 227ea as a blowing agent were used. A polymeric 4,4-diphenylmethane diisocyanate having a functional group of 2.7, an isocyanate group (NCO) content of 30 to 33% and a viscosity of 100 to 400 centipoise (cps) at 25 DEG C was added to 100 parts by weight of a mixed polyol Was used in an amount of 140 parts by weight.

&Quot; Example 2 "

100 parts by weight of a mixed polyol component having an OH value of 550 mgKOH / g (65 parts by weight of a sucrose base polyether polyol, 15 parts by weight of an alphamethyl glucoside base polyether polyol, 15 parts by weight of a polyester polyol and 5 parts by weight of a cross- Polyol component), 1.0 part by weight of water and 10 parts by weight of HFC-365mfc / 227ea as a blowing agent were used. A polymeric 4,4-diphenylmethane diisocyanate having a functional group of 2.7, an isocyanate group (NCO) content of 30 to 33% and a viscosity of 100 to 400 centipoise (cps) at 25 DEG C was mixed with 100 parts by weight Was used in an amount of 150 parts by weight.

&Quot; Example 3 "

100 parts by weight of a mixed polyol component having an OH value of 600 mgKOH / g (60 parts by weight of a sucrose base polyether polyol, 20 parts by weight of an alphamethyl glucoside base polyether polyol, 15 parts by weight of a polyester polyol and 5 parts by weight of a cross- Polyol component), 0.7 parts by weight of water and 12 parts by weight of HFC-365mfc / 227ea as a blowing agent were used. A polymeric 4,4-diphenylmethane diisocyanate having a functional group of 2.7, an isocyanate group (NCO) content of 30 to 33% and a viscosity of 100 to 400 centipoise (cps) at 25 DEG C was mixed with 100 parts by weight Was used in an amount of 153 parts by weight.

&Quot; Example 4 "

100 parts by weight of a mixed polyol component having an OH value of 550 mgKOH / g (55 parts by weight of a sucrose base polyether polyol, 25 parts by weight of an alphamethyl glucoside base polyether polyol, 15 parts by weight of a polyester polyol and 5 parts by weight of a cross- Polyol component), 0.6 parts by weight of water and 13 parts by weight of HFC-365mfc / 227ea as a blowing agent were used. A polymeric 4,4-diphenylmethane diisocyanate having a functional group of 2.7, an isocyanate group (NCO) content of 30 to 33% and a viscosity of 100 to 400 centipoise (cps) at 25 DEG C was added to 100 parts by weight of a mixed polyol 135 parts by weight were used.

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

The performance of the polyurethane foam prepared through the above Comparative Examples and Examples is summarized in Table 2. For the performance comparison in Table 2, the "physical properties" indicated in each term were measured as described below.

First, the free foam density is the foam density (kg / m 3) of the foam injected into an open box made of a plywood having an internal dimension of 200 × 200 × 190 mm, and the product density is a density of the actually produced product (kg / And the density was measured by bubbling into a double insulated tube at a high temperature of 120 캜 at which the inner surface of the inner tube was flowing. In Comparative Examples 1, 2, 3, and 4, the polyurethane composition was injected into the inner pipe at 120 ° C. When the reaction occurred, the polyurethane composition was foamed. After the foaming, the double insulated pipe was cut off and uncharged and cracked However, in Examples 1, 2, 3 and 4, foaming was stably carried out at 120 ° C, the inside of the double insulated tube was completely filled, and the double insulated tube was cut to check the inside thereof No problems were found, and no difficulties were encountered in collecting specimens such as density and thermal conductivity. The thermal conductivity is the result of measurement (according to KS L 9016) using a thermal conductivity meter (Model No. MA01906) of Lasercomp.

The core density is a result of measuring the foaming density (kg / m 3) of the actually produced product in the same manner as the free foaming density.

In addition, the compressive strength was measured using a universal testing machine of hardness precision (according to ASTM D-1621) and the shear strength was measured using a universal testing machine of hardness precision (according to ASTM D-1623) And measured using an universal testing machine (according to KS M 3809).

Adhesion was measured using an adherence tester (DS 2178) of a newly developed laboratory stencil. The independent foam ratio was measured according to ASTM D-2856 and absorbency was measured according to EN-253.

In order to confirm the calculated continuous operating temperature (CCOT) through an accelerated aging test, an insulation layer was foamed at 89.5 mm on a 500 Å pipe, and the casing was HDPE 710 mm (thickness: 11.5 mm) In the pipe was measured using an accelerated aging tester manufactured in-house by the EN-253 standard. As described above, in Comparative Examples 1, 2, 3, and 4, the non-filling and cracks were generated and the accelerated aging test could not proceed. In Examples 1, 2, The foam was not carbonized even after accelerated aging at 170 ° C for 1000 hours or more and maintained the adiabatic performance as well as the performance of the patented product in conformity with the EN-253 standard even after the accelerated aging test.

As described above, the polyurethane foam foamed at 120 캜, which is a high temperature state obtained by the present invention, has a core density of not less than 80 kg / m 3 before accelerated aging, a thermal conductivity of not more than 0.0256 W / mK, a closed cell ratio of 88% The flexural strength is more than 300 이며, and the shear strength is a basic condition having a characteristic of 200 ㎪ or more at room temperature. In addition, the inner surface adhesion that confirms the bonding strength with the adherend is an index to judge the life of the insulator applied to the double insulated pipe.

After accelerated aging, it is preferable that the core density is 80 kg / m 3 or more, the thermal conductivity is 0.0326 W / mK or less, the compressive strength and flexural strength are 150. Or more, and the shear strength is 100. Or more at room temperature. In addition, the inner surface adhesion which confirms the bonding strength with the adherend is an index for judging the life of the heat insulating material, and therefore, it must have a value of 100. Or more.

The results of the tests of Table 2 show that Comparative Examples 1 to 4 are results of foaming a polyurethane foam composition having a composition and content of polyols different from those of the present invention. In Comparative Examples 1 to 4, normal foaming did not occur under the condition of a high temperature condition where the surface of the inner tube was 120 ° C, and normal filling and accelerated aging tests such as unfilled, overfilled, It was impossible to proceed. FIGS. 4 and 5 are photographs of specimens produced according to the comparative example of the present invention and having undergone filling, over-foaming and cracking.

On the other hand, in the case of Examples 1 to 4, measurement results of thermal conductivity and physical strength show substantially excellent properties. For example, it can be seen that not only the standard required for the thermal conductivity is 0.026 W / mK or less, but also excellent compression strength, flexural strength, shear strength, and inner (tube) .

The results of the tests of Table 3 are as follows. In Comparative Examples 1 to 4, a polyurethane foam composition having a composition and content different from those of the present invention was foamed in a pipe to perform an accelerated aging test. However, It was impossible to proceed with normal tests due to unfilled, overfired, cracked, or the like. That is, normal foaming was not performed at a high temperature of 120 ° C, and an accelerated aging test was impossible.

On the other hand, in the case of Examples 1 to 4, even if accelerated aging was performed at 170 ° C for 1000 hours or more according to the test conditions of EN-253, the carbonization phenomenon was small and the thermal conductivity and the physical strength were measured, And has generally excellent properties. For example, the thermal conductivity satisfies the specifications required by 0.030, 0.033, 0.026, and 0.023 W / mK, respectively, but also exhibits excellent performance in terms of compression strength, flexural strength, shear strength and inner (tube) Able to know.

That is, from the above experimental results, the polyurethane foam for a heat-transfer pipe (double insulated tube) capable of foaming in a high temperature state according to the present invention is capable of stably foaming even at a high temperature exceeding a workable temperature of conventional polyurethane It is a breakthrough invention that can serve as a heat insulator.

Hereinafter, with reference to FIG. 3, one embodiment of a foaming method using a high temperature expanded polyurethane insulating material for a heat transfer pipe according to the present invention will be described.

3 is a process diagram for explaining a method of manufacturing a high-temperature expanded polyurethane insulating material for a heat-transferring pipe according to the present invention.

First, the method for manufacturing a high temperature expanded polyurethane insulating material for a heat pipe according to the present invention basically comprises an isocyanate preparing step (S10), a mixed polyol composition preparing step (S20) and an injection foaming reaction step (S30).

First, the isocyanate preparing step (S10) is a step of preparing polymeric 4,4-diphenylmethane diisocyanate. Diphenylmethane diisocyanate, and then adding the modified diphenylmethane diisocyanate to the polymeric 4,4-diphenylmethane diisocyanate. The isocyanate component and its content are as described above.

The step S20 of preparing the mixed polyol composition is carried out by mixing 40 to 80 parts by weight of a polyol having 2 or more functional groups, 0.01 to 1.5 parts by weight of a reaction catalyst, 5 to 20 parts by weight of a foaming agent and 3 to 15 parts by weight of an additive with respect to 100 parts by weight of isocyanate Is prepared using a blended mixed polyol composition.

Here, the components and the content of the mixed polyol composition are as described above.

Meanwhile, the injection foaming reaction step (S30) is a step of reacting the mixed polyol composition solution with isocyanate. The reaction ratio of isocyanate to polyol is also as described above.

Then, the reaction is carried out in a medium-pressure reaction in which the reaction is carried out by mechanically mixing at a pressure of about 20 to 60 kgf / cm 2 in the injection foaming reaction step (S30).

In the present invention, the conventional polyurethane foam is reacted promptly as described in the above comparative example. However, in the present invention, proper combination of polyether polyol and polyester polyol having enhanced heat resistance characteristics and control of flowability through monomolecular crosslinking agent, To control the reactivity, thereby enabling normal foaming.

Since the temperature of the internal heat medium is high even in such a slow reaction, the curing is completed in a short time, and the heat resistance is exhibited through the maximized polyisocyanurate reaction.

In addition to the advantages of minimizing the working time, similar to the production of the existing non-continuous double insulated tube, it is not necessary to insert the spacer at a short distance to maintain the distance between the inner tube and the outer tube. It is possible to reduce the occurrence of heat loss, thereby improving the heat insulation performance and durability of the foam.

In addition, it is possible to apply various working conditions according to the reactivity and the desired property as a working method which can be applied not only to the continuous type which is horizontal but also to the injection type which gives the inclination of 3 to 15..

In other words, the advantages of the existing injection type are combined with the technology that can work directly on the construction site, and it is advantageous to improve the heat insulation and durability of the product, as well as to improve productivity and reduce the defect rate. have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

1: Double insulated pipe 1a: Inner pipe
1b: Appearance 3: End cap
5: injector 7: casing

Claims (15)

A polymeric isocyanate using polymeric 4,4-diphenylmethane diisocyanate having an NCO% of 30 to 33, a functional group of 2.6 to 2.9 and a viscosity of 100 to 400 centipoise (cps) at 25 占 폚;
40 to 80 parts by weight of a mixed polyol having 2 or more functional groups per 100 parts by weight of the polymeric isocyanate;
Acid-blocking the trimerization catalyst to inhibit the initial reaction at 50-120 ° C and to promote the end cure reaction to improve the integrity density (bonding to solidify) 0.01 to 1.5 parts by weight of a reaction catalyst relative to 100 parts by weight of the mixed polyol to induce the reaction to proceed stably;
A hydrofluorocarbon (HFC) blowing agent in which a mixture of water and HFC (Hydrofluorocarbon) -365mfc / 227ea is used alone or a mixture of HFC-365mfc / 227ea and 90-95% by weight of HFC (Hydrofluorocarbon) 5 to 20 parts by weight of a foaming agent relative to 100 parts by weight of a mixed polyol; And
1 to 15 parts by weight of an additive which is used alone or in combination with two or more kinds of surfactants, a flame retardant, a filler, an antioxidant, a stabilizer and a colorant to 100 parts by weight of the mixed polyol, Wherein the mixed polyol composition has an average OH value of 300 to 650 mgKOH / g and an NCO / OH ratio of 1.2 to 2.7, which is an equivalence ratio of the isocyanate NCO to the OH equivalent, is mixed and reacted with the high- lagging. delete delete delete The method according to claim 1,
In the mixed polyol,
10 to 70 parts by weight of a polyether polyol obtained by adding an alkylene oxide to sucrose or sorbitol, which is an initiator having a functional group of 4 or more with respect to 100 parts by weight of the mixed polyol;
5 to 30 parts by weight of a polyether polyol obtained by combining glycerin or trimethylol propane (TMP) with alpha methyl glucoside per 100 parts by weight of the mixed polyol;
5 to 30 parts by weight of an aromatic polyester polyol relative to 100 parts by weight of the mixed polyol so as to maximize conversion of polyisocyanurate in a polyurethane-polyisocyanurate structure; And
A polyhydric alcohol having a molecular weight of less than 300 g / mol and a molecular weight of less than or equal to 3 and having a functional group of 3 or more based on 100 parts by weight of the mixed polyol so as to promote physical fluidity and increase crosslinking density to suppress occurrence of swelling or deterioration during foaming, 1 to 10 parts by weight of a high-temperature expanded polyurethane insulating material for a heat-transferring pipe. delete delete 6. The method of claim 5,
The aromatic polyester polyol may be produced, for example,
Wherein the aromatic polycarboxylic acid is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol, and the aromatic polycarboxylic acid is dimethyl terephthalate, phthalic acid, isophthalic acid or naphthalenedicarboxylic acid, and the polyhydric alcohol is ethylene glycol, diethylene glycol, propylene glycol, , 3-butanediol, 1,6-hexanediol and neopentyl glycol, which are used singly or in combination of two or more, and have an OH value of 200 to 600 mgKOH / g. Polyurethane insulation. delete 6. The method of claim 5,
The polyhydric alcohol may be,
Glycerin, trimethylol propane, pentaerythritol, and the like. delete The method according to claim 1,
The blowing agent may contain,
Wherein 0.1 to 1.0 part by weight of water and 4.9 to 19.0 parts by weight of a HFC (hydrofluorocarbon) blowing agent are mixed with 100 parts by weight of the mixed polyol. delete A method for manufacturing a high temperature expanded polyurethane insulating material for a heat transfer pipe according to claim 1,
A polymeric isocyanate preparing step of preparing a polymeric 4,4-diphenylmethane diisocyanate having an NCO% of 30 to 33, a functional group of 2.6 to 2.9 and a viscosity of 100 to 400 centipoise (cps);
A polymeric isocyanate using polymeric 4,4-diphenylmethane diisocyanate having an NCO% of 30 to 33, a functional group of 2.6 to 2.9 and a viscosity of 100 to 400 centipoise (cps) at 25 占 폚; 40 to 80 parts by weight of a mixed polyol having 2 or more functional groups per 100 parts by weight of the polymeric isocyanate; Acid-blocking the trimerization catalyst to inhibit the initial reaction at 50-120 ° C and promote the end cure reaction to improve the integrity density (solidification) 0.01 to 1.5 parts by weight of a reaction catalyst relative to 100 parts by weight of the mixed polyol so as to induce a stable reaction at a reaction temperature of & A hydrofluorocarbon (HFC) blowing agent in which a mixture of water and HFC (Hydrofluorocarbon) -365mfc / 227ea is used alone or a mixture of HFC-365mfc / 227ea and 90-95% by weight of HFC (Hydrofluorocarbon) 5 to 20 parts by weight of a foaming agent relative to 100 parts by weight of a mixed polyol; And 1 to 15 parts by weight of an additive which comprises a surfactant, a flame retardant, a filler, an antioxidant, a stabilizer and a colorant, and which is used singly or in combination of two or more kinds thereof, based on 100 parts by weight of the mixed polyol, Preparing a mixed polyol composition wherein the mixed polyol has an average OH value of 300 to 650 mgKOH / g and an equivalent ratio of isocyanate NCO to OH equivalent of NCO / OH of 1.2 to 2.7; And
Wherein the polymeric isocyanate and the mixed polyol composition solution are injected into the outer surface of a double insulated tube, and mechanically mixed at a pressure of 20 to 60 kgf / cm < 2 >≪ / RTI > delete

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