KR102142823B1 - Thermal insulation material having water-durability and Manufacturing method thereof - Google Patents

Abstract

The present invention relates to an insulation coating material and a method of manufacturing the same. More specifically, the present invention relates to a hybrid-type insulation coating material which introduces the advantages of a rubber foam insulation material while solving the weak water resistance qualities, which is a problem of an existing polyethylene insulation material; and to a method of manufacturing the hybrid-type insulation coating material. The method of manufacturing of the insulation coating material includes: a step of preparing each of first polyethylene foam and second polyethylene foam; and a step of forming a first laminate in which synthetic rubber foam and the first polyethylene foam are laminated.

Description

Thermal insulation material having excellent water resistance and its manufacturing method

The present invention relates to a hybrid type thermal insulation coating material and a method of manufacturing the same, while introducing the advantages of a rubber foam insulation material, while solving the weak water resistance, which is a problem of the existing polyethylene thermal insulation material.

In general, all pipes that require cooling and heating are covered with an insulating material on the outside for reasons of preventing physical property changes or energy saving when transferring gas or fluid through the pipe, such as power plants, industrial plants, and various piping. When high heat is generated from the gas or fluid being transported, the insulation material must be molded and manufactured using a material having a high melting point to satisfy the insulation function and prevent fire caused by the insulation material.

The rubber foam insulation material is an independent foam structure insulation material foamed with synthetic rubber, and has excellent thermal insulation and moisture resistance. Due to these advantages, rubber foam insulation materials are used in various fields such as cold and hot water piping, air conditioning, industrial plants, and ships, and have been used as a standard insulation for a long time in Europe.

Recently, the use of eco-friendly and flame-retardant and excellent rubber-foamed insulating materials has increased rapidly, but the smell of synthetic rubber and foam gas, the main raw materials of rubber-foamed insulating materials, is present in a small amount inside the insulation cell. The rubber foam insulation has a characteristic odor due to the smell of synthetic rubber and the blowing agent gas, and when using the rubber foam insulation in a sealed room for a long time, it can cause a headache for residents due to the odor. Since the rubber foam insulation material is mainly used for equipment, it was not applied to the space where people live, so there was no problem due to odor, but recently, the demand for expanded application in the interior of buildings has increased rapidly based on the excellent insulation and flame retardancy of the rubber foam insulation material.

Korean Patent No. 10-1350711 (Announcement date 2014. 01. 23)

The present invention seeks to provide a hybrid type heat insulating coating material that introduces the advantages of a rubber foam insulating material while solving the weak flame retardancy, heat insulating property, and low water resistance, which are problems of the existing polyethylene heat insulating material.

In order to solve the above-mentioned problems, the present invention relates to a heat insulating coating material having excellent water resistance, and is a coating material covering an outer circumferential surface of a tube through which a gas or a fluid is transferred, wherein the coating material is a synthetic rubber foam layer, a first polyethylene foam layer, and a second Polyethylene foam layers are sequentially stacked, and embossing projections are formed on the outer surface of the second polyethylene foam layer.

In addition, the object of the present invention relates to a method for manufacturing the heat-resistant coating material having excellent water resistance, the first step of preparing a synthetic rubber foam in the form of a tube, a first polyethylene foam and a second polyethylene foam, respectively; A second step of forming a first laminated body in which the synthetic rubber foam and the first polyethylene foam are laminated by thermally bonding the first polyethylene foam to the outside of the synthetic solid foam at 110 to 130°C; And heat-bonding the second polyethylene foam to the outer surface of the first laminate at 100 to 105° C. to form a tube-shaped laminate in which a synthetic rubber foam layer, a first polyethylene foam layer and a second polyethylene foam layer are sequentially stacked. Three steps of manufacturing; by performing a process comprising a heat insulating coating material can be produced.

The insulating coating material of the present invention, despite including a synthetic rubber foam, does not have a characteristic rubber odor, has excellent water resistance (low water absorption), excellent heat insulation, is resistant to tearing, and excellent in light weight.

1A and B are schematic diagrams of the heat insulating coating material of the present invention.
2A and B are photographs of the insulating coating material of the present invention prepared in Example 1.

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

The heat-resistant insulating material having excellent water resistance of the present invention is a covering material that covers the outer circumferential surface of a tube body through which gas or fluid is transported, as shown in A and B of FIG. 1, a synthetic rubber foam layer, a first polyethylene foam layer, and a second polyethylene foam The layers are sequentially stacked, and an embossing protrusion is formed on the outer surface of the second polyethylene foam layer.

This, the heat insulating coating material of the present invention comprises a first step of preparing a synthetic rubber foam in the form of a tube, a first polyethylene foam and a second polyethylene foam, respectively; A second step of forming a first laminated body in which the synthetic rubber foam and the first polyethylene foam are laminated by thermally bonding the first polyethylene foam to the outside of the synthetic solid foam at 110 to 130°C; And heat-bonding the second polyethylene foam to the outer surface of the first laminate at 100 to 105° C. to form a tube-shaped laminate in which a synthetic rubber foam layer, a first polyethylene foam layer and a second polyethylene foam layer are sequentially stacked. 3 steps to manufacture; can be manufactured by performing a process comprising.

The outer surface of the second polyethylene foam layer of the heat-insulating coating material of the present invention may be formed with embossed projections, which use a second polyethylene foam formed with embossed projections in step 1 above, or a product without embossed projections in step 1 After preparing the three-step laminate using the 2 polyethylene foam, the step of forming an embossing protrusion on the outer surface of the second polyethylene foam layer may be performed.

[Synthetic rubber foam]

The synthetic rubber foam layer is an ethylene-propylene-diene ternary copolymer (EPDM) rubber foam made of a closed-cell structure including an EPDM rubber resin, and the EPDM rubber foam EPDM rubber resin, hydromagnesite, 2 A foam obtained by extruding and foaming a mixed resin containing,5-dimethyl-2,5-di(tetra-butylperoxy)hexane, a lubricant, an odor removing agent, an inorganic filler, an antioxidant, sulfur, a vulcanization accelerator, and a foaming agent. And excellent flame retardancy, but no odor.

The EPDM rubber resin has a Mooney viscosity of 30 to 45 (ML1+4, 125°C), an ethylene content of 55 to 60% by weight, preferably a Mooney viscosity of 30 to 40 (ML1+4, 125) ℃), ethylene content of 56 to 58% by weight, it is good in terms of heat resistance and heat insulation.

Of the mixed resin components, the hydromagnesite serves to increase the flame retardancy of the EPDM rubber foam, and the amount thereof is used in an amount of 20 to 50 parts by weight, preferably 25 to 45 parts by weight, more preferably 100 parts by weight of the EPDM rubber resin. It is good to use 30 to 40 parts by weight. At this time, if the amount of hydromagnesite used is less than 20 parts by weight, it may not be possible to secure a flame retardancy of 35% or more of the oxygen index, and if the amount used is more than 50 parts by weight, there is a problem of reducing miscibility between other components in the mixed resin. It is recommended to use within the above range.

Among the components of the mixed resin, the 2,5-dimethyl-2,5-di(tetra-butylperoxy)hexane (2,5-Dimethyl-2,5-di(t-butylperoxy)hexane) is EPDM rubber and hydromagnesite It is used to improve miscibility and reactivity between components such as peroxide, and it is preferable to use a peroxide content of 90% or more and an active oxygen content of 10% or more. And, the amount of use is 20 to 30 parts by weight, preferably 20 to 27 parts by weight, more preferably 22 to 25 parts by weight, and more preferably 22 to 25 parts by weight based on 100 parts by weight of the EPDM rubber resin. EPDM rubber foam is not enough to ensure sufficient flame retardancy, the heat transfer rate can be increased, and the use of more than 30 parts by weight may be a problem of lowering other physical properties due to excessive use.

The lubricant among the mixed resin components facilitates the mixing of the mixed resin components, and is selected from calcium stearate, zinc stearate, magnesium stearate, aluminum stearate, glycerin stearate, butyl stearate, solid paraffin, and liquid paraffin. It may include one or more, and preferably may include one or more selected from glycerin stearate, solid paraffin, and liquid paraffin. In addition, it is preferable to use 10 to 20 parts by weight, preferably 12 to 18 parts by weight, and more preferably 12 to 17 parts by weight, based on 100 parts by weight of the EPDM rubber resin. At this time, if the amount of the lubricant is less than 10 parts by weight, the amount of use is too small, so the effect of ease of mixing due to the use may be insufficient, and when the amount of the lubricant is used in excess of 20 parts by weight, a problem of deterioration in elasticity and deterioration in resilience of EPDM rubber foam may occur.

The odor-removing agent among the mixed resin components absorbs volatile organic compounds emitted from EPDM rubber resins, etc., and serves to suppress odor generation and to provide antibacterial properties to synthetic solid foams, and may include at least one selected from kaolin and charcoal powder. May preferably, kaolin and charcoal powder in a 1: 3 to 5 weight ratio, more preferably kaolin and charcoal powder in a 1: 3.5 to 4.5 weight ratio. In addition, it is preferable to use 1 to 25 parts by weight, preferably 5 to 25 parts by weight, and more preferably 10 to 25 parts by weight with respect to 100 parts by weight of the EPDM rubber resin. At this time, if the amount of the odor removing agent is less than 1 part by weight, the amount of the odor removing agent may be too small to have little odor removal effect, and if it exceeds 25 parts by weight, the viscosity of the mixed resin may be too high, resulting in insufficient foaming power and poor insulation, EPDM rubber There may be a problem that the weight of the foam is too high.

The inorganic filler in the mixed resin component serves to increase the mechanical strength of the synthetic rubber foam, and may include one or more selected from talc, carbon black and zinc oxide. In addition, the amount of the inorganic filler is preferably 5 to 18 parts by weight, preferably 7 to 15 parts by weight, and more preferably 8 to 13 parts by weight based on 100 parts by weight of the EPDM rubber resin. At this time, if the amount of the inorganic filler is less than 5 parts by weight, the amount of the inorganic filler is too small to improve the physical properties of the synthetic rubber foam. It is good to use.

The antioxidant among the components of the mixed resin is to secure long-term stability of the synthetic solid foam, and a general antioxidant used in the art may be used, for example, stearic acid and BHT (Butylated Hydroxy Toluene). One or more types can be used. In addition, the amount of use is 10 to 20 parts by weight, preferably 10 to 15 parts by weight, based on 100 parts by weight of the EPDM rubber resin. At this time, if the amount of the antioxidant used is less than 10 parts by weight, the antioxidant effect may not last for a long time, and if it is used in excess of 20 parts by weight, the foaming rate of the foam may be reduced and thermal insulation may be deteriorated. .

The sulfur in the mixed resin component serves as a vulcanizing agent, and serves to maintain the shape of the rubber foam, to maintain the shape of the cell formed by foaming, and to maintain strength and elasticity, the amount of which is used in 100 parts by weight of EPDM rubber resin With respect to this, it is preferable to use 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight. At this time, if the amount of sulfur exceeds 0.05 parts by weight, the shape retention of the cells formed in the foam may be deteriorated, and if it exceeds 2 parts by weight, the open cells are formed, resulting in poor elasticity, resilience, and high compression strain.

Among the mixed resin components, the vulcanization accelerator plays a role in assisting the skin formation of the foam, 2-mercapto benzothiazole, tetramethyl thiuram disulide and dipenta methylene Thiuram tetrasulfite (dipenta methylene thiuramtertrasulfide) may include one or more selected from. In addition, it is preferable to use 0.5 to 3 parts by weight, preferably 1 to 2.5 parts by weight, based on 100 parts by weight of the EPDM rubber resin.

The foaming agent in the mixed resin component serves to foam the EPDM rubber resin, azodicarbonamide (ADCA), azodiisobutylonitrile (ABBN), dinitrosopentamethyltetraamine (DNPT), Paratoluene sulfonyl hydrazide (TSH) and oxybisbenzene sulfonyl hydrazide (OBSH) are selected from one or more, preferably azodicarbonamide (ADCA), azodiisobutylonitrile (ABBN) ) And dinitrosopentamethyltetraamine (DNPT). And, the amount of the use is 20 to 35 parts by weight, preferably 23 to 35 parts by weight, more preferably 25 to 32 parts by weight, based on 100 parts by weight of the EPDM rubber resin. At this time, if the amount of the blowing agent used is less than 20 parts by weight, there may be a problem that the synthetic solid foam does not sufficiently foam, resulting in deterioration in thermal insulation, and if it is used in excess of 35 parts by weight, mechanical properties are reduced due to excessive foaming. Since the number of cells per area decreases, there may be a problem in that thermal insulation properties are deteriorated.

When the synthetic rubber foam layer (or EPDM rubber foam) is measured according to KS M ISO 4589-2, it can satisfy an oxygen index of 30% or more, preferably 31 to 38%, and may have high flame retardancy.

In addition, the synthetic rubber foam layer (or EPDM rubber foam) is measured in accordance with KS M 6962, the thermal conductivity of 0.037 W / mK or less, preferably 0.015 ~ 0.035 W / mK, more preferably 0.018 ~ 0.032 W / mK It can satisfy the high insulation.

In addition, the synthetic rubber foam layer (or EPDM rubber foam) can satisfy the compressive strain of 14% or less, preferably 5 to 13%, more preferably 7 to 12% when measured according to KS M ISO 1856. , It can have a high modulus of elasticity or shape restoration.

[First PE foam]

The first polyethylene foam layer serves as a protective layer for the synthetic rubber foam layer (or EPDM rubber foam) and additional heat insulation, as a foam of the first polyethylene (PE) mixed resin, with respect to 100 parts by weight of the mixed polyethylene resin, 2 to 5 parts by weight of anionic surfactant, 0.1 to 1 part by weight of foam control agent and 5 to 10 parts by weight of foaming agent, preferably 2.5 to 4.5 parts by weight of anionic surfactant, 0.2 to 0.5 parts by weight of foam control agent with respect to 100 parts by weight of the mixed polyethylene resin ~ 0.8 parts by weight and 6 to 8.5 parts by weight of the blowing agent, and more preferably, with respect to 100 parts by weight of the mixed polyethylene resin, 3.0 to 4.5 parts by weight of anionic surfactant, 0.5 to 0.8 parts by weight of the foam control agent and 6.5 to 8.0 parts by weight of the blowing agent It can contain.

The mixed polyethylene resin of the first PE mixed resin component is a low-density polyethylene resin and a linear low-density polyethylene resin in a ratio of 1: 0.5 to 1, preferably a low-density polyethylene resin and a linear low-density polyethylene resin in a ratio of 1: 0.5 to 0.8, more Preferably, the low-density polyethylene resin and the linear low-density polyethylene resin are contained in a weight ratio of 1:0.60 to 0.75 in terms of resistance to moisture (water resistance), and if the linear low-density polyethylene resin is less than 0.5 weight ratio, water resistance may deteriorate, 1 If the weight ratio is exceeded, water resistance increases, but there may be a problem that mechanical properties decrease.

The low density polyethylene resin has a melt mass flow rate (MFR) of 2 to 5 g/10 min and a density of 0.920 to 0.925 g/cm ³ , preferably a melt mass flow rate (MFR) of 2 to 4 g/10 min and a density of 0.921 to It is recommended to use 0.925 g/cm ³ .

And, the linear low-density polyethylene resin is MFR 0.5 ~ 5g / 10 min and a density of 0.918 ~ 0.922 g / cm ³ , preferably, MFR 0.5 ~ 2g / 10 min and a density of 0.918 ~ 0.920 g / cm ³ using It is good.

The anionic surfactant in the first PE mixed resin component serves to form and stabilize the foam, sodium lauryl sulfate, potassium lauryl sulfate, and ammonium lauryl sulfate. Sulfate, Sodium Myristyl Sulfate, Sodium Cetyl Sulfate, Sodium Cocoyl Glutamate, Sodium Laureth Sulfate and Ammonium Laureth Sulfate ) May include one or more selected from. If the amount of the anionic surfactant used is less than 2 parts by weight, stabilization of the PE foam may not be easily achieved, and thus it may be easily destroyed by external impact and have poor thermal insulation, and 5 parts by weight is excessively used. It is good.

The foam regulator of the first PE mixed resin component may be a general foam regulator used in the art, preferably, the foam regulator may include sodium bicarbonate and sodium citrate in a weight ratio of 1:0.5 to 1.5, More preferably, sodium bicarbonate and sodium citrate may be included in a weight ratio of 1:0.8 to 1.2 weight ratio.

Among the first PE mixed resin components, the blowing agent may use aliphatic hydrocarbons such as propane, normal butane, isobutane, normal pentane, isopentane, normal hexane, and isohexane, preferably normal butane and isobutane 1:0.1. ~ 0.5 weight ratio, preferably may include normal butane and isobutane in a weight ratio of 1:0.3 to 0.5. At this time, if the amount of the foaming agent used is less than 5 parts by weight, there may be a problem that the PE foam does not sufficiently foam, and when it exceeds 10 parts by weight, the PE foam becomes too foamed due to excessive use, resulting in low density and poor mechanical properties. It may be possible to use within the above range.

[2nd PE foam]

The second polyethylene (PE) foam layer serves as a protective layer and insulation for the synthetic rubber foam layer (or EPDM rubber foam) together with the first PE foam layer, and serves to prevent penetration of external humidity and moisture. As a thing, the second polyethylene foam layer is a foam of a second polyethylene (PE) mixed resin, and the second PE mixed resin includes a mixed polyethylene resin, anionic surfactant, bubble control agent, antioxidant and foaming agent.

The second polyethylene (PE) mixed resin, with respect to 100 parts by weight of the mixed polyethylene resin, 2 to 5 parts by weight of anionic surfactant, 0.1 to 1 parts by weight of the foam control agent, 1 to 5 parts by weight of the antioxidant and 5 to 10 parts by weight of the blowing agent It may contain, preferably with respect to 100 parts by weight of the mixed polyethylene resin, anionic surfactant 2.5 to 4.5 parts by weight, bubble control agent 0.2 to 0.8 parts by weight, antioxidants 2 to 5 parts by weight and foaming agent 6 to 8.5 parts by weight And, more preferably, it may include 3.0 to 4.5 parts by weight of anionic surfactant, 0.5 to 0.8 parts by weight of foam control agent, 2.5 to 4.5 parts by weight of antioxidant, and 6.5 to 8.0 parts by weight of blowing agent with respect to 100 parts by weight of the mixed polyethylene resin. .

In the second PE mixed resin component, the mixed polyethylene resin is a low-density polyethylene resin and a linear low-density polyethylene resin in a weight ratio of 1: 0.5 to 1, preferably a low-density polyethylene resin and a linear low-density polyethylene resin in a weight ratio of 1: 0.7 to 1.0, more Preferably, the low-density polyethylene resin and the linear low-density polyethylene resin in a weight ratio of 1: 0.85 to 1.00 are advantageous in terms of resistance to moisture (water resistance), and if the linear low-density polyethylene resin is less than 0.5 weight ratio, water resistance may drop, 1 If the weight ratio is exceeded, water resistance increases, but there may be a problem that mechanical properties decrease.

The low-density polyethylene resin has a melt mass flow rate (MFR) of 2 to 5 g/10 minutes and a density of 0.920 to 0.925 g/cm ² , preferably a melt mass flow rate (MFR) of 2 to 4 g/10 minutes and a density of 0.921 to It is recommended to use 0.925 g/cm ² .

And, the linear low-density polyethylene resin is MFR 6 ~ 10g / 10 min and a density of 0.918 ~ 0.922 g / cm ² , preferably using MFR 7 ~ 10g / 10 min and a density of 0.918 ~ 0.920 g / cm ² It is good.

The anionic surfactant in the second PE mixed resin component serves to form and stabilize the foam, sodium lauryl sulfate, potassium lauryl sulfate, and ammonium lauryl sulfate. Sulfate, Sodium Myristyl Sulfate, Sodium Cetyl Sulfate, Sodium Cocoyl Glutamate, Sodium Laureth Sulfate and Ammonium Laureth Sulfate ) May include one or more selected from. If the amount of the anionic surfactant used is less than 2 parts by weight, stabilization of the PE foam may not be easily achieved, and thus it may be easily destroyed by external impact and have poor thermal insulation, and 5 parts by weight is excessively used. It is good.

The foam control agent of the second PE mixed resin component may use a common foam control agent used in the art, preferably, the foam control agent may include sodium bicarbonate and sodium citrate in a weight ratio of 1:0.5 to 1.5, More preferably, sodium bicarbonate and sodium citrate may be included in a weight ratio of 1:0.8 to 1.2 weight ratio.

The antioxidant 2,6-bis(1-methylheptadecyl)-p-cresol butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), butylated in the second PE mixed resin component Octylated phenol, hexamethylenebis(3,5-di-t-butyl hydroxy-cinnamate), [bis(2-hydroxy-3-t-butyl -5-methylphenyl)methane] (for example, Cyanox 2246), octadecyl 3,5-di-t-butyl-4-hydroxyhydrocinnamate (e.g. Irganox 1076), and tetrakis (methylene (3,5-di-t-butyl-4-hydride) Hydroxyhydrocinnamate)methane (for example, Irganox 1010), and may include at least one selected from 2,6-bis(1-methylheptadecyl)-p-cresol butylated hydroxyanisole. (BHA), hexamethylenebis(3,5-di-t-butyl hydroxy-cinnamate), [bis(2-hydroxy-3-t-butyl -5-methylphenyl)methane] and octadecyl 3,5 -Di-t-butyl-4-hydroxyhydrocinnamate], and if the amount of the antioxidant is less than 1 part by weight, the amount is too small and the antioxidant effect may be insufficient. If used in excess of 5 parts by weight, the foam may be used for a long period of time, and there may be a problem of color change.

Among the second PE mixed resin components, the blowing agent may use aliphatic hydrocarbons such as propane, normal butane, isobutane, normal pentane, isopentane, normal hexane, and isohexane, preferably normal butane and isobutane 1:0.1. ~ 0.5 weight ratio, preferably may include normal butane and isobutane in a weight ratio of 1:0.3 to 0.5. At this time, if the amount of the foaming agent used is less than 5 parts by weight, there may be a problem that the PE foam does not sufficiently foam, and when it exceeds 10 parts by weight, the PE foam becomes too foamed due to excessive use, resulting in low density and poor mechanical properties. It may be possible to use within the above range.

The first PE mixed resin and/or the second PE mixed resin described above may further include commonly used inhibitors, flame retardants, strength enhancers, pigments, and the like used in the art.

And, the first PE mixed resin and / or the second PE mixed resin 110 ~ 180 ℃, preferably 120 ~ 160 ℃, more preferably prepared by heating and foaming for 10 ~ 20 minutes at 130 ~ 150 ℃ Each of the 1 PE foam and the second PE foam may satisfy an apparent density of 40 to 100 kg/m 3, preferably an apparent density of 50 to 95 kg/m 3, more preferably an apparent density of 65 to 90 kg/m 3.

In addition, each of the first PE foam and the second PE foam may satisfy a dimensional change rate of -5% to 0% in the extrusion direction when heated at 80°C for 24 hours.

The above-described insulating rubber foam layer, the first polyethylene foam layer and the second polyethylene foam layer are laminated in this order, the insulating coating material of the present invention in accordance with ASTM F-1249 method when measuring moisture permeability, moisture permeability is 0.0200 g / m ² · day or less, preferably water permeability of 0.0010 ~ 0.0150 g / m ² · day, more preferably 0.0010 ~ 0.0120 g / m ² · day can be satisfied, it can have a very excellent water resistance.

The present invention will be described in more detail through the following examples, but the following examples are not intended to limit the scope of the present invention, which should be interpreted to help understand the present invention.

[Example]

Example 1-1: Preparation of EPDM rubber foam

Based on 100 parts by weight of EPDM rubber resin (Kumho Polychem, DEP435) having a Mooney viscosity of 33 (ML1+4, 125°C), 34 parts by weight of hydromagnesite (LIKYA MINELCO), 2,5-dimethyl-2, 23 parts by weight of 5-di(tetra-butylperoxy)hexane (Pergan, trade name PEROXAN HX), 15 parts by weight of a lubricant mixed in a glycerin stearate and solid paraffin 1:1 weight ratio, kaolin powder and charcoal powder 1:4 weight ratio 15 parts by weight of an odor removing agent (average particle size of 10 μm or less) mixed with, 10 parts by weight of talc as an inorganic filler, and 12 parts by weight of an antioxidant BHT (Butylated Hydroxy Toluene) as a mixer, and mixed to prepare a mixture.

Next, 0.5 parts by weight of sulfur was added to the mixture, 2 parts by weight of tetramethyl thiuram disulfide as a vulcanization accelerator and 27.5 parts by weight of dinitrosopentamethyltetraamine as a blowing agent, and stirred at 70° C. for 10 minutes to prepare a mixed resin. .

Next, after aging the mixed resin for about 2 hours, the aged mixed resin was extruded into a tube shape with a cylindrical extruder (extrusion pressure 140 bar, extrusion temperature 50°C).

Next, the extrudate extruded in the form of a tube was vulcanized at 70°C for 25 seconds, pre-foamed at 120°C for 20 seconds, followed by foaming at 180°C for 15 seconds, and then aged by heating at 120°C for 10 seconds.

Next, the aged foam was cooled to prepare a tube-shaped EPDM rubber foam.

Examples 1-2 to 1-3 and Comparative Examples 1-1 to 1-3

An EPDM rubber foam was prepared using the same method and components as in Example 1-1, but each of the EPDM rubber foams was prepared by varying the composition ratios of the mixed resins used in the preparation as shown in Table 1 below. ~ 1-3 and Comparative Examples 1-1 to 1-3 were performed, respectively.

division
(Parts by weight) Example
1-1 Example
1-2 Example
1-3 Example
1-4 Comparative example
1-1 Comparative example
1-2 Comparative example
1-3 Comparative example
1-4 EPDM rubber resin 100 100 100 100 100 100 100 100 Hydro Magne
site 34 25 45 34 17 52 34 25 2,5-dimethyl-2,5-di(tetra-butylperoxy)hexane 23 28 21 23 23 23 23 28 slush 15 15 15 15 15 15 15 15 Odor remover 15 15 15 25 15 15 30 15 Inorganic filler 10 10 10 10 10 10 10 10 Antioxidant 12 12 12 12 12 12 12 12 sulfur 0.5 1.7 1.0 0.5 0.5 0.5 0.5 2.3 Vulcanization accelerator 2 2.3 2.3 2 2 2 2 2.3 blowing agent 27.5 27.5 27.5 27.5 27.5 27.5 27.5 27.5

Experimental Example 1: Measurement of physical properties of EPDM rubber foam

Each of the EPDM rubber foams prepared in Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-3 was measured for flame retardancy, heat insulation, and odor, and the results are shown in Table 2 below.

At this time, the flame retardancy, heat insulation, how to measure whether or not odor is generated is as follows.

(1) Flame retardancy (oxygen index (%)): measured according to KS M ISO 4589-2

(2) Thermal insulation (thermal conductivity (W/mK)): measured according to KS M 6962

(3) Compression strain (%): Measured according to KS M ISO 1856

(4) Odor occurrence: After placing the test piece in a 4L container at 10 cm X 10 cm and standing at 60 ± 2°C for 2 hours, 10 panelists performed sensory evaluation to calculate the average value. At this time, the odor rating is as follows. 1: No odor, 2: No odor, but some odor occurs, 3: Smell is weakly detected and what odor is, 4: Strong smell that can be easily detected, 5 = Very strong smell

If the odor sensory evaluation average value was less than 3, there was no odor.

division Oxygen index
(%) Thermal conductivity
(W/mK) Compression strain
(%) Bad smell
Whether Example 1-1 36 0.027 10 2 or less Example 1-2 31 0.024 9 2 or less Example 1-3 38 0.032 12 2 or less Example 1-4 35 0.027 10 1 or less Comparative Example 1-1 22 0.024 9 2 or less Comparative Example 1-2 42 0.045 16 2 or less Comparative Example 1-3 37 0.039 9 1 or less Comparative Example 1-4 36 0.028 15 2 or less

Looking at Tables 1 and 2, the EPDM rubber foams of Examples 1-1 to 1-4 showed appropriate flame retardancy, heat insulation, and compression set while not generating odor.

On the other hand, in the case of Comparative Example 1-1 in which the amount of hydromagnesite used was less than 20 parts by weight, when compared with Example 1-1 and Example 1-2, the oxygen index dropped significantly to 22%, indicating poor flame retardancy. . In addition, in the case of Comparative Example 1-2 in which the amount of hydromagnesite used exceeded 50 parts by weight, the flame retardancy was good, but the thermal conductivity was 0.045 W/mK, which was a significantly increased value compared to Example 1-3, and the insulation was not good. The results showed.

In addition, in the case of Comparative Examples 1-3 using 30 parts by weight exceeding 25 parts by weight of the malodor removing agent, when compared with Example 1-4, the foaming power was lowered, and as a result, the cell formation was poor, resulting in high It showed thermal conductivity, that is, low thermal insulation.

In addition, in the case of Comparative Example 1-4 in which the amount of sulfur used exceeded 2 parts by weight, the compressive strain was significantly increased when compared with Example 1-2, which resulted in a large amount of open cells in the EPDM rubber foam, resulting in poor elasticity and resilience. Because.

Example 2-1: Preparation of first polyethylene foam

MFR (melt mass flow rate) 2.4 g/10 min, low density polyethylene resin with a density of 0.922 g/cm ³ (Dow Chemical, NUC8321) and MFR 1.0 g/10 min, linear low density polyethylene resin with a density of 0.920 g/cm ³ (LG SP310) was mixed at a weight ratio of 1:0.68 to prepare a mixed polyethylene resin.

With respect to 100 parts by weight of the mixed polyethylene resin, anionic surfactant of sodium cocoilutamate 3.5 parts by weight, sodium bicarbonate and sodium citrate 1: 1 weight ratio of 0.65 parts by weight of the foam control agent, normal butane and isobutane 1:0.3 ~ A first polyethylene mixed resin was prepared by mixing 7.2 parts by weight of the blowing agent mixed in a 0.5 weight ratio.

Next, the first polyethylene mixed resin was extruded in the form of a tube, and the extrudate was heated and foamed at 140° C. for 15 minutes to prepare a tube-shaped first polyethylene foam (apparent density = about 82 kg/m 3 ).

Examples 2-2 and Comparative Examples 2-1 to 2-2

A first polyethylene foam was prepared in the same manner as in Example 2-1, but as a mixed polyethylene resin, each using a mixed polyethylene resin comprising a low density polyethylene resin and a linear low density polyethylene resin as shown in Table 3 below. Each was prepared.

Then, the dimensional change rate in the extrusion direction when heated at 80° C. for 24 hours for each of the foams of Examples 2-1 to 2-2 and Comparative Examples 2-1 to 2-2 was measured, and the results are as follows. It is shown in Table 3.

division Low density polyethylene resin and
Linear low density polystyrene resin weight ratio Extrusion direction
Dimensional change rate Example 2-1 1: 0.68 -1.4% Example 2-2 1: 0.50 -1.1% Comparative Example 2-1 1: 0.35 -0.7% Comparative Example 2-2 1: 1.10 -6.5%

Looking at Table 3, as the content of the linear low-density polyethylene resin decreased, a tendency for the dimensional change rate to decrease was shown. In the case of Comparative Example 2-2, the dimensional change rate exceeded -5%, and -6.5% showed a bad result.

Example 3-1: Preparation of second polyethylene foam

MFR (melt mass flow rate) 2.4 g/10 min, low density polyethylene resin with a density of 0.922 g/cm ³ (Dow Chemical, NUC8321) and MFR 1.0 g/10 min, linear low density polyethylene resin with a density of 0.920 g/cm ³ (LG SP310) was mixed at a weight ratio of 1: 0.90 to prepare a mixed polyethylene resin.

With respect to 100 parts by weight of the mixed polyethylene resin, 3.5 parts by weight of sodium cocoilutamate as an anionic surfactant, 0.65 parts by weight of a bubble control agent mixed in a ratio of 1 to 1 by weight of sodium bicarbonate and sodium citrate, tetrakis as an antioxidant (methylene (3, 5-di-t-butyl-4-hydroxyhydrocinnamate)methane (IRGANOX 1010) 3.3 parts by weight, 7.2 parts by weight of blowing agent mixed with normal butane and isobutane in a weight ratio of 1:0.3 to 0.5, mixed with the second polyethylene Resin was prepared.

Next, the second polyethylene mixed resin was extruded in the form of a tube, and the extrudate was heated and foamed at 140° C. for 15 minutes to prepare a tube-shaped first polyethylene foam (apparent density=about 78 kg/m 3 ).

Examples 3-2 and Comparative Examples 3-1 to 3-2

A second polyethylene foam was prepared in the same manner as in Example 3-1, but as a mixed polyethylene resin, a mixed polyethylene resin comprising a low density polyethylene resin and a linear low density polyethylene resin, respectively, as shown in Table 4 below. Each was prepared.

And, the dimensional change rate in the extrusion direction when heated at 80° C. for 24 hours for each of the foams of Examples 3-1 to 3-2 and Comparative Examples 3-1 to 3-2 was measured, and the results are shown in the table below. It is shown in 4.

division Low density polyethylene resin and
Linear low density polystyrene resin weight ratio Extrusion direction
Dimensional change rate Example 3-1 1: 0.90 -2.3% Example 3-2 1: 0.68 -1.6% Comparative Example 3-1 1: 1.10 -6.9% Comparative Example 3-2 1: 0.40 -1.2%

Looking at Table 4, Examples 3-1 to 3-2 and Comparative Example 3-2 using a linear low-density polyethylene resin in a weight ratio of less than 1 with respect to the low-density polyethylene resin had a small dimensional change rate of -5 to 0%. However, Comparative Example 3-1 had a large problem in dimensional change.

Preparation Example 1: Preparation of insulating coating material

The tube-shaped EPDM rubber foam (synthetic rubber foam) prepared in Example 1-1 was wrapped with a tube-shaped first polyethylene foam prepared in Example 2-1, and then heat-bonded under about 125°C to obtain EPDM rubber. A first laminate was prepared in which a foam (synthetic rubber foam) and a first polyethylene foam were laminated.

Next, the first laminated body is wrapped with a second polyethylene foam in the form of a tube prepared in Example 3-1, and then heat-sealed (heat-bonded) under about 100 to 105°C to form a synthetic rubber foam layer, the first polyethylene foam. A laminate in the form of a tube in which the layer and the second polyethylene foam layer were sequentially stacked was prepared.

Next, after wrapping a polyethylene sheet with embossed projections formed on the surface of the second polyethylene foam of the laminate, thermal bonding (heat bonding) was performed at 100 to 105° C. to prepare an insulating coating material of the form A and B in FIG. 1. .

Pictures of the prepared insulating coating material are also shown in A and B of FIG. 2, and A and B of FIG. 2 are manufactured by varying the sizes of the tubular EPDM rubber foams prepared in Example 1-1.

Production Examples 2 to 4 and Comparative Production Examples 1 to 3

By manufacturing the insulating coating material in the same manner as in Preparation Example 1, the first polyethylene foam layer and the second polyethylene foam layer were prepared as shown in Table 5 below to prepare an insulating coating material, to prepare Examples 2 to 4 and Comparative Production Example 1 ~ 3 was performed respectively.

division Synthetic rubber
Foam layer 1st polyethylene
Foam layer Second Polyethylene
Foam layer Preparation Example 1 Example 1-1 Example 2-1 Example 3-1 Preparation Example 2 Example 1-1 Example 2-2 Example 3-1 Preparation Example 3 Example 1-1 Example 2-1 Example 3-2 Preparation Example 4 Example 1-1 Example 2-2 Example 3-2 Comparative Production Example 1 Example 1-1 Comparative Example 2-1 Example 3-1 Comparative Production Example 2 Example 1-1 Example 2-1 Comparative Example 3-1 Comparative Production Example 3 Example 1-1 Example 2-1 Comparative Example 3-2

Experimental Example 2: moisture permeability measurement

The moisture permeability of the insulating coating materials prepared in Preparation Examples 1 to 4 and Comparative Preparation Examples 1 to 3 were measured to determine whether or not moisture penetration (water resistance) was found, and the results are shown in Table 6 below.

At this time, the moisture permeability was measured according to ASTM F-1249 method, but was measured using 3/33 equipment of MOCON.

division Moisture permeability (g/m ² ·day) Preparation Example 1 0.0053 Preparation Example 2 0.0089 Preparation Example 3 0.0116 Preparation Example 4 0.0122 Comparative Production Example 1 0.0219 Comparative Production Example 2 0.0020 Comparative Production Example 3 0.0834

Looking at the production examples 1 to 4, the higher the linear low density PE resin content compared to the low density PE resin in the mixed PE resin used for the production of the first polyethylene foam layer and/or the second polyethylene foam layer, the lower the moisture permeability and the higher the water resistance. It was confirmed that it had a tendency.

However, in the case of Production Example 3 (Example 2-1 and Example 3-2) using the same linear low density PE resin content ratio in the mixed PE resin used for the production of the first and second polyPE foams, Production Example 1 and It can be seen that the moisture permeability is increased than that of Preparation Example 2, through which the first and second poly PE foams were prepared by having a higher content ratio of linear low density PE resin in the second mixed PE resin than the first mixed PE resin, It was confirmed that lamination was advantageous in terms of water resistance.

In the case of Comparative Production Example 1 in which the linear low-density PE resin in the first mixed PE resin was used in an amount of less than 0.5 weight ratio, there was a problem in that water resistance was significantly reduced when compared with Production Example 1 and Production Example 2.

In the case of Comparative Production Example 2, the moisture permeability was very low and the water resistance was excellent, but as shown in Table 4 above, the second PE foam had a problem that the dimensional change rate was too large.

And, in Comparative Production Example 3 in which the linear low-density PE resin in the second mixed PE resin was less than 0.5 weight ratio, it was confirmed that there was a problem in that water resistance was greatly deteriorated.

Through the above Examples and Experimental Examples, the insulating coating material of the present invention has a characteristic rubber odor, despite having a synthetic rubber foam, excellent water resistance (low moisture absorption), excellent heat insulation, strong tear resistance, and excellent light weight. It was confirmed that an insulating coating material can be provided.

Claims (8)

It is a covering material that covers the outer circumferential surface of the tube body through which gas or fluid is transferred.
The coating material is a synthetic rubber foam layer, a first polyethylene foam layer and a second polyethylene foam layer are sequentially stacked,
The outer surface of the second polyethylene foam layer is formed with embossed projections,
When the covering material covers the outer peripheral surface of the tube body, the synthetic rubber foam layer is in contact with the outer peripheral surface of the tube body,
The first polyethylene foam layer is a foam of a first polyethylene (PE) mixed resin, the first PE mixed resin is 100 to 5 parts by weight of the mixed polyethylene resin, anionic surfactant 2 to 5 parts by weight, bubble control agent 0.1 to 1 weight Parts and 5 to 10 parts by weight of blowing agent,
The second polyethylene foam layer is a foam of a second polyethylene (PE) mixed resin, and the second PE mixed resin is 2 to 5 parts by weight of anionic surfactant and 0.1 to 1 weight of foam control agent per 100 parts by weight of the mixed polyethylene resin. Part, contains 1 to 5 parts by weight of antioxidant and 5 to 10 parts by weight of blowing agent,
Each of the mixed polyethylene resin of the first PE mixed resin and the mixed polyethylene resin of the second PE mixed resin contains a low-density polyethylene resin and a linear low-density polyethylene resin in a weight ratio of 1:0.5 to 1,
The low density polyethylene resin has a melt mass flow rate (MFR) of 2 to 5 g/10 minutes and a density of 0.920 to 0.925 g/cm ³ , and the linear low density polyethylene resin has a melt mass flow rate (MFR) of 0.5 to 5 g/10 minutes and a density. Insulation material with excellent water resistance, characterized in that 0.918 ~ 0.922 g / cm ³ .
According to claim 1, wherein the synthetic rubber foam is an ethylene-propylene-diene ternary copolymer (EPDM) rubber foam composed of a closed-cell structure (Close-Cell),
The EPDM rubber foam is a mixture comprising EPDM rubber, hydromagnesite, 2,5-dimethyl-2,5-di(tetra-butylperoxy)hexane, lubricant, odor removing agent, inorganic filler, antioxidant, vulcanization accelerator and foaming agent A heat-resistant insulating material having excellent water resistance, characterized in that the resin is a foamed body extruded and foamed.
The method of claim 2, wherein the mixed resin is 20 to 50 parts by weight of hydromagnesite, 20 to 30 parts by weight of 2,5-dimethyl-2,5-di(tetra-butylperoxy)hexane, based on 100 parts by weight of EPDM rubber. , 10 to 20 parts by weight of lubricant, 1 to 25 parts by weight of odor removing agent, 5 to 18 parts by weight of inorganic filler, 10 to 20 parts by weight of antioxidant, 0.5 to 3 parts by weight of vulcanization accelerator and 20 to 35 parts by weight of blowing agent Thermal insulation coating with excellent water resistance.


delete delete delete A first step of preparing a tubular synthetic rubber foam, a first polyethylene foam, and a second polyethylene foam, respectively;
A second step of forming a first laminated body in which the synthetic rubber foam and the first polyethylene foam are laminated by thermally bonding the first polyethylene foam to the outside of the synthetic rubber foam at 110 to 130°C;
The second polyethylene foam is thermally adhered to the outer surface of the first laminate at 100 to 105°C to produce a tube-like laminate in which a synthetic rubber foam layer, a first polyethylene foam layer and a second polyethylene foam layer are sequentially stacked. Step 3; And
On the outer surface of the second polyethylene foam layer, the outer surface performs a process comprising; four steps of forming embossed projections,
The tube-shaped laminate is a covering material, and when the covering material covers the outer peripheral surface of the tubular body, the synthetic rubber foam layer contacts the outer peripheral surface of the tubular body,
The first polyethylene foam layer is a foam of a first polyethylene (PE) mixed resin, the first PE mixed resin is 100 to 5 parts by weight of the mixed polyethylene resin, anionic surfactant 2 to 5 parts by weight, bubble control agent 0.1 to 1 weight Parts and 5 to 10 parts by weight of blowing agent,
The second polyethylene foam layer is a foam of a second polyethylene (PE) mixed resin, and the second PE mixed resin is 2 to 5 parts by weight of anionic surfactant and 0.1 to 1 weight of foam control agent per 100 parts by weight of the mixed polyethylene resin. Part, contains 1 to 5 parts by weight of antioxidant and 5 to 10 parts by weight of blowing agent,
Each of the mixed polyethylene resin of the first PE mixed resin and the mixed polyethylene resin of the second PE mixed resin contains a low-density polyethylene resin and a linear low-density polyethylene resin in a weight ratio of 1:0.5 to 1,
The low density polyethylene resin has a melt mass flow rate (MFR) of 2 to 5 g/10 minutes and a density of 0.920 to 0.925 g/cm ³ , and the linear low density polyethylene resin has a melt mass flow rate (MFR) of 0.5 to 5 g/10 minutes and a density. 0.918 ~ 0.922 g / cm ³ characterized in that the method of manufacturing a heat insulating coating material having excellent water resistance.
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