KR20140030349A - 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 foaming polyurethane-insulation material for a heat transporting pipe and, more specifically, characterized in reacting by mixing isocyanate with a polyol mixture composition with 40-80 parts by weight of polyol having two or more functional groups, 0.01-1.5 parts by weight of a reaction catalyst, 5-20 parts by weight of a blowing agent, and 1-15 parts by weight of an additive are mixed based on 100 parts by weight of the isocyanate. According to the present invention as described above, polyurethane foam is stably foamed in a high-temperature double heating pipe without scorch or crack at high temperature and a high-temperature foaming polyurethane-insulation material for a heat transporting pipe having excellent heat insulation properties, mechanical strength, etc. can be produced. [Reference numerals] (AA) Start; (BB) Medium pressure foam maker; (CC) End; (S10) Manufacture a polyol mixture; (S20) 4,4-diphenylmethane diisocyanate; (S30) Injection, foaming reaction step (50-120°C heat transfer pipe in a high-temperature condition)

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 mixed polyol composition comprising isocyanate and 40 to 80 parts by weight of a polyol of functional group 2 or more, 0.01 to 1.5 parts by weight of reaction catalyst, 5 to 20 parts by weight of blowing agent and 1 to 15 parts by weight of an additive based on 100 parts by weight of the isocyanate It is characterized by reacting by mixing.

Here, the isocyanate uses 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.

Here, the said mixed polyol composition has an average OH value of 300-650.

Here, the mixed polyol composition has NCO / OH of 1.2 to 2.7, which is NCO% of the isocyanate to OH of the polyol.

Herein, the mixed polyol is polyisocyanur in a polyether polyol and a PIIR structure having enhanced heat resistance by combining sucrose or sorbitol, an initiator having a functional group of 4 or more, alphamethylglucoside, glycerin or trimethylolpropanol (TMP). An aromatic polyester polyol that maximizes the conversion rate of polyisocyanurate, consists of a low molecular weight polyhydric alcohol having a functional group of 3 or more to promote stable foaming by promoting physical fluidity and increasing crosslinking density to suppress swelling or deterioration during foaming. .

Here, the polyether polyol is a polyether polyol comprising 10 to 70 parts by weight of a polyether polyol having an alkylene oxide added to the sucrose or sorbitol, and glycerin or trimethylolpropane (TMP) combined with alphamethylglucoside. 5-30 parts by weight of the mixture.

Here, the said aromatic polyester polyol is mixed at 5-30 weight part.

Here, the aromatic polyester polyol is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol, and the aromatic polycarboxylic acid is dimethyl telephthalate, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the polyhydric alcohol is ethylene glycol, diethylene glycol, Glycols of propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, and neopentylglycol are applied, and may be used alone or in combination of two or more, with a hydroxyl value of 200 to 600 gKOH / g. to be.

Here, the low molecular weight polyhydric alcohol is mixed at 1 to 10 parts by weight.

Here, the reaction catalyst is a trimerization catalyst or an amine catalyst.

Here, the blowing agent is mixed with 0.1 to 1.0 parts by weight of water and 5 to 20 parts by weight of HFC blowing agent based on 100 parts by weight of polyol.

Here, the additive may be used alone or in combination of two or more, including a surfactant, a flame retardant, a filler, an antioxidant, a stabilizer and a colorant.

According to another aspect of the present invention,

In the method for producing a high-temperature foamed polyurethane insulation for heat transport pipe, Isocyanate preparation step of preparing a polymeric 4,4-diphenylmethane diisocyanate; Mixing to prepare a mixed polyol composition comprising 40 to 80 parts by weight of a polyol of functional group 2 or more, 0.01 to 1.5 parts by weight of reaction catalyst, 5 to 20 parts by weight of blowing agent and 1 to 15 parts by weight of additive, based on 100 parts by weight of the isocyanate Preparing a polyol composition; And an injection foam reaction step of reacting the isocyanate and the mixed polyol composition solution by injecting the inside of the double insulation tube.

Here, the injection foam reaction step is reacted in a medium pressure manner by reacting the isocyanate and the mixed polyol composition solution by mechanically mixing at a pressure of 20 ~ 60kgf / ㎠.

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 may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

The high-temperature foamed polyurethane insulation for heat transport tubes according to the present invention is made by reacting a mixture of a polyol having a high functional group having two or more hydroxyl groups, a polyisocyanate having at least two or more isocyanate groups, a blowing agent, a reaction catalyst, and an additive. It is possible to produce a rigid polyurethane foam having excellent durability as well as being able to foam and adhere to steel pipes for heat transport tubes in a high temperature state while maintaining excellent thermal insulation properties, which are characteristics of general rigid urethane foams.

More specifically, 40 to 80 parts by weight of an isocyanate and a polyol having two or more functional groups based on 100 parts by weight of the isocyanate, 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 It is prepared by mixing and reacting a mixed polyol composition.

Here, the polyol is a polyether polyol having enhanced heat resistance by combining sucrose or sorbitol, an initiator having a functional group of 4 or more, and alphamethylglucoside, glycerin or trimethylolpropanol (TMP); Aromatic polyester polyols for maximizing the conversion of polyisocyanurate in the PUIR structure; And a low molecular weight polyhydric alcohol having a functional group of 3 or more so as to promote physical fluidity, increase crosslinking density, suppress occurrence of swelling or deterioration during foaming, and promote stable foaming.

The polyether polyol may be 10 to 70 parts by weight of a polyether polyol obtained by adding an alkylene oxide to sucrose or sorbitol, and 5 to 30 parts by weight of a polyether polyol obtained by combining glycerin or trimethylolpropane (TMP) with alphamethylglucoside. Are mixed. At this time, when the polyether polyol having the alkylene oxide added to sucrose or sorbitol is 10 parts by weight or less, the strength and dimensional stability are weakened. If it is 70 parts by weight or more, the flowability of the mixed polyol composition is reduced. It should be mixed in parts by weight, and when the polyether polyol in which alpha methyl glucoside is combined with glycerin or trimethylolpropane (TMP) is 5 parts by weight or less, the fluidity and adhesion enhancing effect is too small. Since dimensional stability is inferior and preferably should be mixed to 10 to 20 parts by weight.

In addition, the aromatic polyester polyol is mixed 5 to 30 parts by weight, but if 5 parts by weight or less, the effect of improving heat resistance and oil resistance is inferior; 20 parts by weight is mixed.

At this time, the aromatic polyester polyol is an ester of an aromatic polycarboxylic acid and a polyhydric alcohol, and the aromatic polycarboxylic acid is dimethyl telephthalate, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid, and the polyhydric alcohol is ethylene glycol, diethylene glycol, propylene glycol, Glycols of 1,4-butanediol, 1,3-butanediol, 1,6-hexanediol, and neopentylglycol are applied and used alone or in combination of two or more, with a hydroxyl value of 200 to 600 gKOH / g.

In addition, the low molecular weight polyhydric alcohol is mixed 1 ~ 10 parts by weight, less than 1 part by weight it is difficult to expect the effect of increasing the physical fluidity and suppress the deterioration, more than 10 parts by weight due to excessive increase in the crosslinking density appropriate reactivity It becomes difficult to control and preferably 3 to 7 parts by weight is mixed.

At this time, the low molecular weight polyhydric alcohol in the technical field of polyurethane, the polyol compound generally refers to an oligomer having a molecular weight of about 500 or more, in the present invention is used in the sense including a low molecular weight polyhydric alcohol. Low molecular weight polyhydric alcohols are believed to be particularly effective for increasing the crosslinking density and improving swelling and deterioration during foaming. As low molecular weight polyhydric alcohols, compounds having three or more functional groups such as glycerin, trimethylolpropane, pentaerythritol, oxypropylated ethylene diamine, hexamethylene diamine, and m-phenyldiamine are exemplified as preferred.

On the other hand, the reaction catalyst is 0.01 to 1.5 parts by weight with respect to 100 parts by weight of polyol, if less than 0.01 parts by weight of the rigid polyurethane foam production reaction is not completed in the reaction due to the deterioration of physical properties can not expect the role of the catalyst, When it is larger than 1.5 parts by weight, the reaction is excessively accelerated, so that carbonization or sponge phenomenon may occur (carbonization or sponge phenomenon occurs more severely due to the high heat of the internal heat medium), and preferably 0.1 to 0.8 parts by weight. do.

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, trimerization and terrimerization catalyst are reactions of three aliphatic or aromatic isocyanates to form isocyanurates (trimerization reaction), which catalyzes the reaction, and some tertiary. An amine or some organometallic catalyst is 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 foaming agent is mixed with 5 to 20 parts by weight with respect to 100 parts by weight of polyol, but when water and HFC are mixed, 0.1 to 2.0 parts by weight of water and 5 to 20 parts by weight of HFC are preferable. 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.

In this case, HFCs are used as water or fluorocarbon blowing agents. 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.

Moreover, although 3-15 weight part of additives are mixed, it is used individually or in combination of 2 or more types including surfactant, a flame retardant, a filler, antioxidant, a stabilizer, and a coloring agent.

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 at this time is preferably 1.0 to 4.0 parts by weight, more preferably 1.2 to 3.0 parts by weight with respect to 100 parts by weight of the 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 is generally 100 to 2000 cst, and the molecular weight is preferably 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 using a flame retardant, the usage-amount is 5-20 weight part with respect to 100 weight part of polyols, More preferably, it is 10-15 weight part. 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 300 to 650 for producing a stable rigid polyurethane foam. If the average OH value of the mixed polyol composition is 300 or less, the formation reaction and crosslinking reaction may not occur, and thus the dimensional stability and mechanical strength of the product may be reduced, and if the average OH value is more than 650, the overall physical property value becomes weak. As a result, the average OH value out of the above-described proper range becomes a cause of product defects and the productivity is lowered.

As the isocyanate component reacted with the mixed polyol composition, 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 is used. 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. Moreover, as for the reaction ratio of an isocyanate component and the mixed polyol component, it is preferable that NCO / OH which is ratio of NCO of a mixed isocyanate component and OH of a polyol is 1.2-2.7, More preferably, it is 1.4-2.5. 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. If the NCO / OH ratio exceeds 1.3 and less than 2.7, the isocyanate is present in excess. At this time, the remaining isocyanate forms allophanate and biuret by addition reaction through completion of polyurethane foam formation. Due to the improvement of the physical properties.

In addition, the isocyanate at high temperature forms strong isocyanurate bond through its own reaction, which is stronger than general urethane bond, so it is difficult to be easily broken, so it is excellent in chemical stability and thermal stability, which is resistant to heat, excellent flame retardancy, and low thermal conductivity. It can be maintained.

Therefore, when the blending ratio of the polyol component and the isocyanate component to be reacted is outside the above range, the object of the present invention cannot be achieved.

According to the present invention, a polyurethane foam can be obtained by reacting a blowing agent, a reaction catalyst and other additives by using the mixed polyol component and the isocyanate component of the special composition as the 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 (40 to 50 parts by weight of sorbitol + EO / PO, 20 to 30 parts by weight of pentaerythritol + OH, toluenediamine + EO / PO 10 20 parts by weight, a mixed polyol component consisting of 10 to 15 parts by weight of ethylenediamine + EO / PO), and 10 to 15 parts by weight of HFC-365mfc / 227ea and 0.1 to 1.0 part by weight of water or 0.8 to 2.5 parts by weight alone as a blowing agent. It was. 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 (20-30 parts by weight of sorbitol + EO / PO, 30-40 parts by weight of pentaerythritol + OH, toluenediamine + EO / PO 10 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 ˜20 parts by weight, a mixed polyol component consisting of 15 to 20 parts by weight of ethylenediamine + EO / PO. 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 a hydroxy group (-OH) value of 500 (70 parts by weight of sucrose base polyether polyol, 10 parts by weight of alphamethylglucoside base polyether polyol, 17 parts by weight of polyester polyol, and 3 parts by weight of crosslinking agent). 0.5 parts by weight of water and 15 parts by weight of hydrofluorocarbon (HFC-365mfc / 227ea) were used as the mixed polyol component) and the blowing agent. 140 parts by weight of polymer 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) Wealth was used.

&Quot; Example 2 "

100 parts by weight of a mixed polyol component having a hydroxy group (-OH) value of 550 (65 parts by weight of sucrose base polyether polyol, 15 parts by weight of alphamethylglucoside base polyether polyol, 15 parts by weight of polyester polyol, and 5 parts by weight of crosslinking agent). 1.0 parts by weight of water and 10 parts by weight of hydrofluorocarbon (HFC-365mfc / 227ea) were used as the mixed polyol component) and the blowing agent. 150 parts by weight of a mixed polyol containing 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). Parts by weight were used.

&Quot; Example 3 "

100 parts by weight of a mixed polyol component having a hydroxy group (-OH) value of 600 (60 parts by weight of sucrose base polyether polyol, 20 parts by weight of alphamethylglucoside base polyether polyol, 15 parts by weight of polyester polyol, and 5 parts by weight of crosslinking agent). 0.7 parts by weight of water and 12 parts by weight of hydrofluorocarbon (HFC-365mfc / 227ea) were used as the mixed polyol component) and the blowing agent. A polymer 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) is added to 100 parts by weight of the mixed polyol. Parts by weight were used.

&Quot; Example 4 "

100 parts by weight of a mixed polyol component having a hydroxyl group (-OH) value of 550 (55 parts by weight of sucrose base polyether polyol, 25 parts by weight of alphamethylglucoside base polyether polyol, 15 parts by weight of polyester polyol, and 5 parts by weight of crosslinking agent). 0.6 parts by weight of water and 13 parts by weight of hydrofluorocarbon (HFC-365mfc / 227ea) were used as the mixed polyol component) and the blowing agent. 135 parts by weight of a polymer 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) Wealth was 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 mixed polyol composition comprising isocyanate and 40 to 80 parts by weight of a polyol of functional group 2 or more, 0.01 to 1.5 parts by weight of reaction catalyst, 5 to 20 parts by weight of blowing agent and 1 to 15 parts by weight of an additive based on 100 parts by weight of the isocyanate A high temperature foamed polyurethane insulation for heat transport pipes, characterized in that the reaction by mixing. The method of claim 1,
The isocyanate is,
A high-temperature foamed polyurethane heat insulating material for a heat transport tube, characterized by using 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. The method of claim 1,
The mixed polyol composition,
High temperature foamed polyurethane insulation for heat transport pipes, characterized in that the average OH value is 300 ~ 650. The method of claim 1,
The mixed polyol composition,
The high-temperature-foaming polyurethane insulation for heat transport pipes, characterized in that NCO / OH which is NCO% of the isocyanate to OH of the polyol is 1.2 ~ 2.7. The method of claim 1,
The above-
Polyether polyols having enhanced heat resistance by combining sucrose or sorbitol, an initiator having a functional group of 4 or more, and alphamethylglucoside, glycerin or trimethylolpropanol (TMP);
Aromatic polyester polyols for maximizing the conversion of polyisocyanurate in the PUIR structure; And
A high temperature foamed polyurethane thermal insulation for heat transport tubes, comprising a low molecular weight polyhydric alcohol having a functional group of 3 or more to promote physical fluidity, increase crosslinking density, suppress swelling or deterioration during foaming, and promote stable foaming. The method of claim 5, wherein
The polyether polyol,
10 to 70 parts by weight of a polyether polyol having an alkylene oxide added to the sucrose or sorbitol, and 5 to 30 parts by weight of a polyether polyol obtained by combining glycerin or trimethylolpropane (TMP) with alphamethylglucoside. High-temperature foamed polyurethane insulation for heat transport pipes. The method of claim 5, wherein
The aromatic polyester polyol may be produced, for example,
High-temperature foamed polyurethane insulation for heat transport pipes, characterized in that mixed by 5 to 30 parts by weight. The method of claim 7, wherein
The aromatic polyester polyol may be produced, for example,
It is an ester of aromatic polycarboxylic acid and polyhydric alcohol, aromatic polycarboxylic acid is dimethyl telephthalate, phthalic acid, isophthalic acid, naphthalenedicarboxylic acid is applied, polyhydric alcohol is ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1 Glycols of, 3-butanediol, 1,6-hexanediol, and neopentylglycol are applied, and may be used alone or in combination of two or more, and the high-temperature foamed poly for heat transportation pipes having a hydroxyl group of 200 to 600 gKOH / g. Urethane insulation. The method of claim 5, wherein
The low molecular weight polyhydric alcohol,
High-temperature foamed polyurethane insulation for heat transport pipes, characterized in that mixed in 1 to 10 parts by weight. The method of claim 9,
The low molecular weight polyhydric alcohol is functional group 3 or more,
A high temperature foamed polyurethane insulation for heat transport tubes, characterized in that any one of glycerin, trimethylolpropane, pentaerythritol, oxypropylated ethylene diamine, hexamethylene diamine, and m-phenyldiamine. The method of claim 1,
The reaction catalyst,
A high temperature foamed polyurethane insulation for heat transport tubes, characterized in that the trimerization catalyst or amine catalyst. The method of claim 1,
The blowing agent,
A high temperature foamed polyurethane heat insulating material for a heat transport tube, characterized by mixing 0.1 to 1.0 parts by weight of water and 5 to 20 parts by weight of HFC foaming agent with respect to 100 parts by weight of polyol. The method of claim 1,
Preferably,
A high temperature foamed polyurethane heat insulating material for a heat transport tube, comprising a surfactant, a flame retardant, a filler, an antioxidant, a stabilizer and a coloring agent, or used alone or in combination of two or more. A method for manufacturing a high temperature expanded polyurethane insulating material for a heat transfer pipe according to claim 1,
An isocyanate preparation step of preparing a polymeric 4,4-diphenylmethane diisocyanate;
Mixing to prepare a mixed polyol composition comprising 40 to 80 parts by weight of a polyol of functional group 2 or more, 0.01 to 1.5 parts by weight of reaction catalyst, 5 to 20 parts by weight of blowing agent and 1 to 15 parts by weight of additive, based on 100 parts by weight of the isocyanate Preparing a polyol composition; And
Method for producing a high-temperature foamed polyurethane thermal insulation material for a heat transport tube, characterized in that consisting of an injection foaming reaction step of reacting the isocyanate and the mixed polyol composition solution to the inside of the double insulation tube. 15. The method of claim 14,
The injection foam reaction step,
Method for producing a high-temperature foamed polyurethane thermal insulation material for a heat transport tube, characterized in that the reaction is carried out by a medium pressure reaction by mechanically mixing the isocyanate and the mixed polyol composition solution at a pressure of 20 ~ 60kgf / ㎠.

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