KR100712898B1 - Rigid polyurethane panel recycling waste polyurethane foams - Google Patents

Abstract

   The present invention is to put a light waste urethane product in the existing hard urethane panel products to manufacture a hard polyurethane panel for building and to provide a production system suitable therefor. According to the present invention, a considerable amount of waste urethane foam can be recycled, thereby greatly improving the problem of environmental pollution, and greatly reducing the cost of the produced urethane panel for construction.

   Hard waste urethane foam, recycling, undiluted solution, hard urethane foam, formulated prescription

Description

   Rigid polyurethane panel recycling waste polyurethane foams}             

   1 is a schematic diagram of a urethane sandwich panel manufacturing process for recycling the hard waste urethane foam according to the present invention.

Figure 2 is an example of the form and specifications of the waste polyurethane foam used in the present invention.

The present invention relates to a rigid urethane panel and a manufacturing technology of the recycled rigid waste urethane foam.

  As industrial society develops highly, the amount of waste generated increases. In other words, mass production, mass sales, mass consumption and mass disposal are being combined with the increase in consumption due to population growth, industrial development, and improved living standards. Therefore, there is a greater need for waste disposal and recycling.                         

  However, existing waste disposal methods are only landfilled or incinerated and the recycling rate remains low. Landfilling and incineration have limitations on the site and facilities, and controversy over human hazards is caused by environmental pollution such as odors, harmful gases, pests, and leachate, and environmental hormones such as dioxins during incineration.

From an economic point of view, the continued rise in waste disposal costs is a burden for both manufacturers, consumers and governments. Therefore, reducing the waste itself is best, but recycling the waste once it has become a very important issue. Recycling must be very important even in the finiteness of resources and the lack of resources in Korea.

  Currently, the amount of polyurethane foam generation in Korea is estimated to be about 50,000 tons per year, and polyurethane forms a three-dimensional crosslinked structure in the course of the reaction, and has insoluble insoluble characteristics, and this characteristic enables various applications of polyurethane. Let's do it. In particular, the foam (foam) is very large volume per unit mass not only difficult to collect, but also causes a lot of problems in the yard process, landfill treatment. In the incineration treatment, CFC used as a blowing agent may be generated, and other harmful gases are generated.

  Domestic waste polyurethane treatment method has not yet found an appropriate method. Waste polyurethane is collected through reverse distribution or municipalities, which are dismantled, separated and crushed by recycling companies. As of 1996, about 58% of the home appliances recovered were consigned, 26% were landfilled, and 16% were reused after repair. However, it is easy to think that the amount of waste home appliances to be buried and consigned will increase due to consumer's preference for high quality and inducement of new product purchase by manufacturers.

  Some small businesses have attempted to reuse waste polyurethane from consignment companies. However, most of the companies did not run their business continuously, and the level was negligible. The waste polyurethanes that these companies introduced from the consignment processing companies are attributed to the different characteristics of each processing company and the failure to overcome the technical problems caused by the use of simple fillers.

  The present invention aims to develop a product using recycled polyurethane foam as part of a proper treatment method of waste polyurethane foam in an increasing trend, and to develop a commercialization technology by a more realistic approach. To do this, we select a product with less stringent performance as the primary model and conduct basic research for its commercialization. This research will be done through measures to prevent the strength reduction of reused products, possibility of introduction into existing production process, and optimization. Furthermore, it will expand to products such as laminating sheets using automobile polyurethane foam and automobile interior materials, and expand its application fields by developing flame retardant materials using foams generated from nonflammable products. The basic research of this study is expected to be a good basic data.

The present invention is expected to be a big cost reduction by replacing a considerable amount of new polyurethane raw material for the waste polyurethane foam, it is expected to increase the competitiveness of the product and market dominance. Furthermore, it is possible to produce various products with higher performance.

  Accordingly, an object of the present invention is to manufacture a foamed urethane foam by spraying urethane stock solution on it after inserting it between the iron plate and the iron plate after cutting the waste foam into a certain size and shape in the manufacturing of a rigid urethane panel for construction. The present invention provides a construction urethane panel and a manufacturing method of recycled waste urethane foam manufactured by using a stock solution design to increase the method and flowability.

According to the present invention, the environmental problems caused by the waste urethane foam can be substantially reduced, and thus the urethane panel manufactured can increase the economic efficiency due to the large cost reduction effect.

   When explaining the waste urethane foam recycling construction urethane panel of the present invention in more detail, the rigid waste urethane foam that had to be embedded or incinerated is cut into a certain size and shape, inserted between the panel steel plate and the iron plate, and sprayed the urethane stock solution thereon, Foamed to produce a rigid polyurethane panel for construction.

   One of the characteristic constitutions of the present invention, to be recycled, the waste urethane foam to be cut is approximately horizontal, 2 to 6 cm square or rectangular diced or horizontal, 2 to 6 cm vertical, so as to be suitable for the building panel of the present invention. Bar shape of about 150 ~ 200cm in length is suitable. However, the cutting shape, size, and length of the waste urethane foam can be freely adjusted according to the use purpose and application location in construction.

One of the characteristic features of the present invention is that the waste urethane foam is cut and processed into a predetermined form, for example, diced or rod-shaped, and inserted between the steel plates for panels, and sprayed, foamed, cured and cut the urethane stock solution thereto. In the continuous process, such as cooling, the use of a water-foaming urethane stock solution that can increase the flowability and miscibility of the waste urethane foam and the new urethane stock solution to be foamed.

   The present invention is a continuous type of hardened urethane foam between the upper and lower material steel plates for polyurethane sandwich panels, inserting in the form of rods or rods, injecting urethane stock solution (new material), foaming aging and curing, and cutting them to the required length. Manufactured by process.

  More specifically, the water-foaming polyurethane stock solution of the present invention is formulated by mixing 5 to 20 weight percent of polyester polyol having a hydroxyl value of 300 to 500 mgKOH / g and 95 to 80 weight percent of a polyether polyol. 85 to 90% by weight of mixed polyol having a hydroxyl value of 420 ± 15 mgKOH / g, 5 to 7% by weight of phosphorus flame retardant, 7 to 20% by weight of polyoxyethylene ether, 0.5 to 3.0% by weight of catalyst, and 0.5 to 2.0 organic foaming agent. It is composed of a mixture of a resin premix composed of 2% by weight to 2% by weight of water and an organic polyisocyanate, which is applied to the continuous method to prepare a hard recycled urethane sandwich panel.

For example, a suitable composition of the above composition is shown in the following table.

Composition Usage (by weight) Remarks Polyol 95 Foam stabilizer 2.0 Flame retardant 20 catalyst 2.5 Crosslinking agent 5.0 Other additives water 1.3 Chemical blowing agents Foaming Agent (HCFC-141B) 25 Physical blowing agent Polymeric MDI 148 Index 120 F.R.D 32 ± 1 C / T G / T T / F / T 14 ± 1 58 ± 3 85 ± 5

The features and conditions of the constituent factors will be described in more detail below.

1. Isocyanate

 MDI (Methylene Diphenyl Diisocyanate) is a substance obtained by treating phosgene (Phosgene, COCl 2) with diphenylmethane diamine (MDA) produced by condensation of aniline and formaldehyde. The reaction product contains several kinds of isomers and polynuclears, but upon purification it is separated into Pure MDI (or Crude MDI). Monomeric MDI is a white solid at room temperature, so it is used after being modified into a liquid phase such as carbodiimide-modified MDI or uretonimine-modified MDI.

Polymeric MDI is a liquid at room temperature, and the average number of functional groups of products is 2.3 ~ 3.0 level and is characterized by viscosity, reactivity and NCO% content. Viscosity of the product depends on the average molecular weight and NCO% content of the product, mainly used in refrigerators, containers, spray (spray), building insulation and automobile interiors.                     

Monomeric MDI is mainly used for non-foaming polyurethanes such as spandex, synthetic leather, elastomers, coatings and sealants.

Comparing the Polymeric MDI and Momomeric MDI is as follows.

Monomeric MDI Polymeric MDI Molecular Weight  250.3 360-400 Appearance (room temperature)  solid Liquid color  White ~ pale yellow Brown importance 1.19 at 40 ℃ 1.24 at 25 ℃ Viscosity (cps at 25 ℃)  - 100-3,000

2. Polyol

  Polyols are oligomers having an —OH group at the end of the molecule and react with isocyanates to form the main chain of the urethane foam polymer. The physical properties of the rigid polyurethane foams depend on the initiator, OHV, functional group, etc. of this polyol.

Since rigid foams require high independent foaming ratio, strong physical strength, and excellent dimensional stability, polyols have a small amount of ethylene oxide or propylene oxide added to a multifunctional initiator with high crosslinking density. It has a low molecular weight (300-700, short molecular chain) structure.

Kinds are largely classified into a polyester form and a polyether form.

Polyester Type:                     

     Polyether Type:

3. Foaming Agent (Si-SURFACANT)

 Hard foam stabilizers have the following effects during the foaming process:

① organic action

  -Foam components have limited solubility in each other.

  -Si-Surfactant distributes each component finely and uniformly.

② Cell Stabilization

  -Prevent cell breakage, coalescence and cell thinning due to bubble destabilization

③ Cell growth

  -Grow bubbles, lower pressure difference between bubbles to prevent gas diffusion and prevent urethane cells from growing and becoming uneven

④ dispersion                     

  -By dispersing the gas inserted during mixing by reducing the surface tension of the reactants

    Form many small bubbles.

4. Flame retardant

   In general, rigid foams are combustible, so that the flame retardant is added to control the extinguishing performance by self-extinguishing. It is divided into halogen type and phosphorus type, and is classified into non-reactive type and reactive type.

      ① Good mixing with raw materials and additives

      ② It should not affect the mechanical properties of the final product.

③ Less fumes and toxic gas are generated during combustion.

5. Catalytic

 The rate of chemical reaction is influenced by the catalyst used in combination with the chemical structure of the raw materials and the temperature of the reaction mixture.

 Catalysts used for the reaction of isocyanates with active hydrogen-containing compounds (polyols), depending on the amount of reactivity, affect the overall process properties involved in the formation of the surface / core layer of the product, such as the flowability and quality of the reaction mixture and the properties of the resulting product. Crazy

The catalyst widely used for the production of polyurethane foam is tertiary amine compound, and various kinds of tertiary amine are distributed in the market, and it plays a role of promoting only a specific reaction in manufacturing urethane foam according to the characteristics of the product. Therefore, it is common to use two or more types of catalysts in combination, and they are classified into active catalysts and delayed catalysts.

6. Blowing agent

 It foams urethane foam, absorbs some of the heat of reaction to prevent overheating of the foam internal temperature, lowers the viscosity of the resin, and serves as a gaseous phase in the cell to control thermal conductivity.

  ① Physical blowing agent: The blowing agent mixed with the resin is vaporized by the heat of reaction generated during the reaction and acts as a blowing agent.

② Chemical blowing agent: Water, acid, etc. generate carbon dioxide by chemical reaction with isocyanate, and this carbon dioxide plays a role of foaming foam.

7. Chemical reaction

 Basic urethane bonds are formed by addition of an alcohol with an active hydroxyl group (-OH) and an isocyanate with an isocyanate group (-N = C = O) to generate heat of reaction by addition polymerization.

 Isocyanates having at least one isocyanate group (-NCO Group) and alcohols having at least one hydroxyl group (-OH) are called polyfunctional groups, and the functional group dissipates high-temperature heat under appropriate conditions, while (-NCOO-) n It produces a compound having a structure of. It is called a urethane bond, and more than 1000 molecules are bonded to a polyurethane. Polyurethane is used. This reaction occurs mainly. to provide.

   On the other hand, the continuous building panel production process used suitably for the present invention will be described.

  Insulation panel made of rigid polyurethane foam has extremely excellent insulation performance, self-adhesiveness, ease of manufacture and versatility, waterproof effect, ease of workability and construction, excellent adhesion to face, magnetic buoyancy, and improvement of working environment. Increasing flame retardancy, stable weather conditions, and a pleasant living environment are increasing the consumption of consumers.

In the construction panel using steel plate as a face material, the coil is fixed at a certain position to check the appearance and quality of appearance, and when it is transferred to the forming line, it is molded into a model suitable for wall or roof. The steel sheet thus formed is preheated to a desired constant temperature within 35 ° C. to 45 ° C. in the preheating zone, and MDI and resin are mixed and injected into the upper surface of the lower plate by high pressure mechanical foaming. The injected liquid stock is produced as a complete product through the cutting process and the transfer line which is changed into solid insulation while passing through the hardening zone and then cut into a certain shape. Referring to Figure 1 schematically showing such a process as follows.

Process A (Steel Preparation and Transfer Line)

   Occurrence: Poor use, Poor adhesion,

   Control item: Color of iron plate, deformation state of iron plate, surface state of iron plate

B process (product forming line)

   Occurrence: Change of use (inconsistent roof type, wall), non-compliance of standard,

              Condition of iron plate

   Control item: Profiling (product molding machine) installation, curing oven (Oven)

            Same moving speed as

Process C (Purethane By-Products)

  Generation phenomenon: Determination of recycling rate of urethane by-products

  Management item: Regular control of urethane by-products

D process (preheating)

  Occurrence: Poor adhesion

  Control item: proper operation of boiler or steam, proper temperature management

             (35 ℃ ~ 50 ℃), atmosphere condition

E process (injection foaming)

   Occurrence: Shrinkage of foam, crack of foam, unfilled, poor adhesion.                     

   Control item: Circulating pressure of foaming machine, discharge pressure (about 130bar), temperature control of stock solution

             (20 ℃ ~ 23 ℃), proper discharge amount, accurate stock ratio, foam reactivity and

             Density, moving speed of the foamer head, and the spread state of the stock solution.

F process (hardening line)

   Occurrence: Insecure hardening (deflation), excessive swelling, foam leak (leak)

   Control item: Accurate side block installation, proper temperature control (40 ℃ ~ 50 ℃),

              Correct insertion position of side paper

G process (cutting line)

   Occurrence: Inaccurate dimension (Problem in assembly)

   Control item: exact position of saw blade, same movement speed as main line

H process (cooling line, constant temperature room)

   Occurrence: Wave of material steel plate caused by heat of exothermic reaction

   Control items: constant temperature facility (room cooling), temperature control according to seasonal temperature,

              Ensure conveyor flatness.

I Process (Product Transfer and Loading Lines) * Not shown.

   Occurrence: Dropping possibility of product, deformation of product, comprehensive judgment

   Control item: Possibility of falling when moving the product, same moving speed as the main line, and when loading

Insert a buffer in the middle of the product, do not load more than a certain amount

In the building panel production process as described above, the improvements to be especially developed according to the present invention are considered as follows.

1. Steel plate angle adjustment

Continuous building panels are produced while maintaining a constant shape and angle by the molding machine during the transfer of the upper plate and the lower plate. The shape acts as an important factor to produce various kinds and can be largely divided into roofing material and wall use. Here, the angle of the iron plate is closely related to the defective rate of the product, and in the case of general product production, the surface defect does not occur much, so each company does not consider much.

However, since urethane by-products are introduced, many surface defects occur due to non-uniform differences in products. Therefore, in order to reduce the defect of the appearance of the iron plate and finally to produce a perfect product, the steel plate surface was formed at an angle of 40 ° to 45 ° larger than the current iron plate angle of 25 ° to increase the strength to withstand external forces. 2 shows an improved angle adjustment feature of the present invention.

Due to the angle adjustment.

 ① Reduced productivity decrease

 ② reduction of defective rate

 ③ Strengthen the product

④ The increase of resistance by external force can be mentioned.

2. Iron plate temperature control

In panel production using urethane insulation, the upper and lower iron plate temperature should be maintained about 10 ℃ higher than that of PS panel. In addition, since urethane by-products are used, and new materials (urethane stocks) are used in comparison with general products, even if the temperature is maintained at around 35 ° C or less, poor adhesion does not occur. By controlling the temperature slightly higher than the temperature currently being applied to the production, preferably maintained at about 35-50 ℃ to increase the activity of the surface of the steel sheet was able to maintain the adhesive strength with the urethane foam foam or more than the current product.

Referring to the stock solution conditions and features of the recycled urethane panel production of the present invention are as follows.

1. Polyurethane Foam Properties

For construction purposes, the Korean Industrial Standard (KS M 3809-1992) complies with the requirements of "Plate-shaped thermal insulation with faceplates which are foamed between faceplates on the basis of polyisocyanates, polyols and blowing agents and molded into sandwiches by self-adhesion". Urethane panel corresponds to 2 type 2 (medium density) among the types of thermal insulation pipes, and its physical specifications are as follows.

Kinds Density kg / m3 Thermal conductivity kcal / mh ℃ Bending strength kgf / cm2 Compressive strength kgf / cm2 Absorption g / 100 cm2 Remarks Insulation 2 types No. 1 45 or more 0.020 ↓ 3.5 ↑ 1.5 ↑ 3.0 ↓ High density No. 2 35 or more 0.020 ↓ 2.5 ↑ 1.0 ↑ 3.0 ↓ Medium density No. 3 25 or more 0.021 ↓ 1.5 ↑ 0.8 ↑ 3.0 ↓ Low density

    1) Density: It is related to the product production standard, and the thickness of insulation urethane foam is used as it is or cut to a certain dimension and the length and width are about 100x100mm to measure the density and volume.

       Density (Kg / m3) = Weight (Kg) / Volume (m3)

2) Strength: The rigid polyurethane foam for panel is basically measured in two ways.

 ① Compressive Strength: It is one of the strength properties of a rigid foam and it shows the degree to which the foam withstands external compressive deformation. The measuring method compresses 10% of the foam height vertically or horizontally with respect to the foaming direction to measure the strength of the surface area.

     Compressive strength (Kgf / cm2) = strain load (Kgf) / cross section of the specimen (cm2)

② Flexural Strength: It is one of the strength properties of rigid foam, and it can know the degree to which the foam can withstand the external lateral force. The measurement measures the strength that is broken when a force is applied at the center and fixed to the edge with respect to the longitudinal direction of the foam cut into constant dimensions.

Flexural Strength (Kgf / cm2) = [3x Maximum Load (kgf) x Span (cm)] / [2x Width (cm) x Thickness 2 (cm2)]

3) Thermal Conductivity: The ability of a material to transfer heat, which measures the thermal performance of a rigid foam. The lower this value, the better the thermal insulation. (Unit = Kcal / mhr ℃)

4) Water Absorption: It shows the property of absorbing water per certain area of hard urethane foam made of closed structure.

Absorption (g / 100cm2) = {[Final Weight-Reference Weight] /

[2x (bxlength + lengthxthickness + thicknessxbutterfly)]} x100

5) Dimensional Stability: The degree of dimensional deformation caused by external changes (low temperature, high temperature, high temperature + high humidity) of foam with a certain size. The form of deformation takes the form of contraction, expansion, and the like.

   Measurement method of dimensional stability

    * Low temperature stability: -30 ℃, measuring volume change after 24 hours

    * High temperature stability: 70 ℃, volume change measurement after 24 hours

    * High temperature and high humidity stability: Relative humidity 95%, 70 ℃, Volume change measurement after 24 hours

             Volume change rate = (V2-V1) / V1

V1 = volume before change, V2 = volume after change

Examples and Comparative Examples

According to the method of the present invention, a urethane panel (after modification) using waste urethane foam was prepared, and as a comparative example, a polyurethane panel (existing) was prepared using a stock solution without using waste urethane foam. The waste urethane foam was processed into a rod shape of 5 cm x 5 cm x 100 cm and introduced at the ratio of the following table.

Each component usage amount and characteristic are shown in the table below.

  Waste urethane foam of the present invention prepared as described above was subjected to a physical property test according to the KS test method. The test results are shown in the table below.

Test Items unit Result Test Methods Thermal conductivity W / m.k 0.022 KS M 3809-97, Plate Heat Flow Meter Bending strength N / cm ² 30 KS M 3809-97 Compressive strength N / cm ² 16 KS M 3809-97 Absorption amount g / cm ³ 1.9 KS M 3809-97 combustibility clear KS M 3809-97 density kg / m ³ 35 KS M 3809-97

As confirmed from the test results, the present invention using waste urethane foam by-products prepared by processing waste polyurethane foam to a certain shape and size in the manufacture of a rigid polyurethane sandwich panel according to the present invention and foaming with water-repellent urethane stock solution Recycling urethane foam has a cost savings of about 60-70% in terms of cost when the ratio of waste urethane foam is about 70%, compared to the urethane foam manufactured only with conventional stock solutions. The ratio of waste urethane foam used can be adjusted as needed. On the other hand, as a result of the physical property test, it can be seen that the urethane foam for building panel of the present invention manufactured using waste urethane foam has excellent properties.

The present invention completely removes environmental problems, which is a social problem by cutting the rigid waste urethane foam as a by-product and inserting it when manufacturing a rigid polyurethane panel for construction, and reducing the processing cost of a urethane discharge company, and a continuous manufacturing process. As a result, about 25,000 tonnes, or 50% of the hard waste urethane foam produced annually, can be reused.

Claims (3)

5 to 20% by weight of a polyester polyol having a concentration of 300 to 500 mgKOH / g and 95 to 80% by weight of a polyether polyol are mixed and mixed with a polyol having a functional group of 2 to 6 and a hydroxyl value of 420 ± 15 mgKOH / g Resin premix and organic poly consisting of 90% by weight, 5-7% by weight of phosphorus flame retardant, 7-20% by weight of polyoxyethylene ether, 0.5-3.0% by weight of catalyst, 0.5-2.0% by weight of organic foaming agent, and 2-5% by weight of water While isocyanate is mixed to prepare a polyurethane resin stock solution, the upper and lower material steel sheets for sandwich panels are molded into a predetermined form, and the pre-heated urethane by-products are cut into a predetermined size and shape between hard waste urethane foams between the material steel sheets. Injecting the polyurethane resin stock solution between the material steel sheet, foamed, aged, cured, cut into a predetermined form, building polyurethane sandwich panel manufactured by a continuous process of transport and loading.    The polyurethane sandwich panel for building according to claim 1, wherein the waste urethane foam is formed in the shape of a cube having a width, length, and height of 2 to 6 cm, or a rod having width, length, 2 to 6 cm, and length of 150 to 200 cm.    The polyurethane sandwich panel for building according to claim 1, wherein the angle of refraction of the raw material steel sheet is molded at about 40 to 45 degrees.

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