KR101236553B1 - Method for manufacturing foam insulation having a function of resistance to flame - Google Patents

Abstract

PURPOSE: A method for manufacturing a flame resisting-foam insulating material is provided to provide effects which are harmless to humans, are eco-friendly, and can prevent the generation of toxic gas in case of fire. CONSTITUTION: A method for manufacturing a flame resisting-foam insulating material comprises: a step of forming a mixed powder by mixing one of chaff powder and bamboo powder with starch at a weight ratio of 1:1 to 1:3 in a mixer; a step of pouring water into the mixer, stirring the mixed powder for 20-30 minutes, and mixing the mixed powder into a viscous semisolid; a step of inserting expandable graphite subsequent to adding polypropylene resin into the mixer; a step of mixing the mixed powder in the mixer for 30-40 minutes, and extruding the mixed powder to be pelletized by a pellet extruder; a step of drying the manufactured pellet with a water content of less than 10%; and a step of manufacturing the flame resisting-foam insulating material with a water content of 10-15% by foaming the dried pellet, which is inserted into a foaming extruder, with water vapor pressure.

Description

Method for manufacturing flame retardant foam insulation {METHOD FOR MANUFACTURING FOAM INSULATION HAVING A FUNCTION OF RESISTANCE TO FLAME}

The present invention relates to a method for manufacturing a flame retardant foam insulation, and more particularly, to a method for manufacturing a flame retardant foam insulation which is improved to be environmentally friendly and harmless to humans and to be manufactured at low cost without generating toxic gases in case of fire.

In general, various types of heat insulators used for heat insulation such as houses are disclosed.

Examples of such heat insulating materials include mineral heat insulating materials such as glass fibers and rock wool, plastic heat insulating materials such as rigid urethane foam and extrusion polystyrene foam, and heat insulating materials using natural components such as cellulose fibers and carbonized foam cork.

Among these, plastic insulation, especially foam plastic insulation, is drawing attention according to the recently tightened regulations on environmentally harmful substances.

As an example, Japanese Laid-Open Patent Publication No. 2003-41041 discloses a foamed polystyrene insulating material, which has a high carbon number in its molecular structure, so that residual carbon which cannot react with oxygen is incompletely burned, and carbon is sooted, so that There is a disadvantage that smoke occurs during incineration.

As another example, Korean Patent Publication No. 2003-0090700 and Patent No. 0954903 have an example of using starch and paper (shares) in order to implement a uniform foam to increase the foaming ratio and heat insulation performance, Korean Patent Publication No. 2011-0111265 There is an example using paper pellets.

In addition, Korean Patent Publication No. 2006-0083990 discloses general plastics such as polyethylene (PE), polypropylene (PP), polyamide (6 nylon, 6,6 nylon, and the like; PA), polyethylene terephthalate (PET), and the like as foam materials. Or biodegradable plastics such as polylactic acid.

However, since these insulations are vulnerable to heat, there is a drawback of causing great damage to property as well as human damage in case of fire.

Therefore, in order to increase the flame retardancy, these insulations are manufactured and sold with a flame retardant material (flame retardant material), but halogen compounds, metal hydroxides, metal oxides (Al (OH) ₃ , Mg (OH) _2, etc.), halogen phosphate ester compounds, etc. Representative flame retardants, including N, are expensive and lead to cost increases, and in some cases carcinogens are also regulated.

In this regard, in Korean Patent No. 1025248 and Korean Patent No. 0622205, expanded graphite is used to realize flame retardancy while having eco-friendliness and harmlessness to a human body.

However, the disclosed patent is made of a polystyrene foam as the base material, but the flame retardancy is realized in the case of fire, but because it generates a strong toxic gas, it is harmful to the human body, the manufacturing process is complicated, and the extrudeability after mixing with expanded graphite product There is a disadvantage that workability is bad.

The present invention was created in view of the above-mentioned problems in the prior art, and has been created to solve this problem. However, even though the flame retardant is added to the heat insulator, there is no harm to the human body even when the flame retardant is added. Main purpose is to provide a method for manufacturing a flame retardant foam insulation that can be easily manufactured at low cost as well as maintaining the expansion ratio and insulation performance.

The present invention is a means for achieving the above object, 30-40% by weight of mixed starch mixed with either starch or bamboo flour; Expanded graphite 5-15% by weight; In the method for producing a flame-retardant foam insulation is composed of the remaining polypropylene resin, the moisture content is maintained at 10-15%; The mixed powder is mixed with the chaff powder or bamboo flour and starch in a blender at a weight ratio of 1: 1-1: 3; When the mixing step is completed, add water to the blender and stir for 20-30 minutes to mix the mixture into a viscous semi-solid state having a viscosity; When the stirring is completed, the addition step of adding a polypropylene resin, and sequentially adding expanded graphite; When the addition of the additives is completed, the mixing step for 30-40 minutes in a mixer, and extruding the mixed mixture by a pellet extruder pelletizing step; A drying step of drying the pellets produced by the extrusion process at room temperature to maintain a water content of 10% or less; Fire-retardant foam insulation material comprising a dried pellets into a foaming extruder and foaming by steam pressure while adding water vapor foaming step of manufacturing a flame-retardant foam insulation having a water content of 10 to 15%; Provide a method.

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At this time, in the extrusion processing step, the addition of an inorganic flame retardant of any one of aluminum hydroxide, magnesium hydroxide, aluminum hydroxide and magnesium hydroxide mixture after mixing with a blender is further characterized in that it is extruded.

According to the present invention, it is possible to produce a flame-retardant foam insulation material at a low cost, it is harmless to the human body and environmentally friendly, it is safe and easy to manufacture do not generate harmful gases even in the case of fire.

Hereinafter, preferred embodiments according to the present invention will be described in detail.

Before describing the present invention, the following specific structural or functional descriptions are merely illustrative for the purpose of describing an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention may be embodied in various forms, And should not be construed as limited to the embodiments described herein.

In addition, the embodiment according to the concept of the present invention can make various changes and have various forms. However, it should be understood that the embodiments according to the concept of the present invention are not intended to limit the present invention to specific modes of operation, but include all modifications, equivalents and alternatives falling within the spirit and scope of the present invention.

The flame-retardant foam insulation according to the present invention by weight, consisting of chaff and starch mixed 30-30%, flame retardant 5-15%, the rest of the base resin, but is configured to have a water content of 10-15%.

At this time, chaff powder and starch are added 30-40% by weight of the mixed powder mixed in a weight ratio of 1: 1 to 1: 3.

Here, the chaff powder is to crush the chaff to have a particle size of 0.1mm or less, chaff is a preservative, unlike wood flour does not harm the human body.

In particular, chaff is used as a filler to reduce the toxic gases generated by the combustion of synthetic resins and increase the flame retardancy.

In addition, the reason for using chaff in the present invention is because chaff particles have a needle-like structure, good binding and compatibility with the base resin, excellent firmness, low water absorption rate, antibacterial function and mold This is because there is a function to prevent that.

In this case, straw flour or bamboo flour having a similar structure may be used instead of the chaff.

In addition, the starch may be any one of raw starch and processed starch, as shown in the known patent literature, and as the raw starch, one of corn starch, potato starch, wheat starch, rice starch, tapioca starch is used. Examples of the processed starch include etherified starch, esterified starch, crosslinked starch, starch degradable roasted dextrin and British gum, oxygen-modified dextrin, and acid. Decomposed starch or oxidized starch can be used.

This starch is added to increase the uniform and stable foaming and expansion ratio while performing a crosslinking role with chaff during foaming of the base resin.

Therefore, chaff and starch should be in equal proportions or higher in starch content. As described above, chaff and starch are most preferably used in the form of a mixed meal in a weight ratio of 1: 1 to 1: 3.

It is too viscous when mixed with a weight ratio of more than three times the content of starch, resulting in poor moldability and processability (extrusion), and above all, deterioration of foamability, roughness of the bubble shape, and ultimately poor insulation performance. It should be limited to the above range.

In addition, the chaff and starch mixed powder should be added in an amount of 30-40% by weight in the present invention in order to facilitate binding and compatibility with the base resin, and moldability.

The flame retardant uses expanded graphite.

Expandable Graphite has a layered structure of graphite, so that when an atom or small molecule is inserted between layers, it is separated like an accordion, and the particles expand hundreds of times. It is a material used in various fields such as fire retardant urethane foam.

However, since the characteristics of the expanded graphite depend on the homogeneity of the quality, the homogeneity of the quality is very important.The homogeneity of the quality is the uniformity of the expansion start temperature, the uniformity of the particle size, the uniformity of the expansion ratio, and the purity (carbon content). And uniformity.

Such expanded graphite is flame retardant by forming a stable scale-like layer on heat or chemicals due to the expansion of graphite. In particular, it is eco-friendly because there is no halogen component and there is no problem of leaching heavy metals. It is safe and harmless to human body.

In the present invention, it should be added in the range of 5-15% by weight in consideration of moldability and flame retardancy, if less than 5% by weight of the flame retardancy is sharply lowered, if it exceeds 15% by weight added to the above range because it inhibits the composition Should be.

In particular, in the present invention in consideration of the base resin (polypropylene, polyethylene) added to ensure the homogeneity of the expanded graphite expansion start temperature is 200-250 ℃, particle size is 50-100 mesh, expansion ratio is 100-350 Cm 3 / g, purity is required to contain at least 85% carbon.

On the other hand, the base resin is a component constituting the base (Base) of the foam insulation of the present invention, polypropylene or polyethylene is used.

In terms of foamability, polyurethane looks good, but polyurethane is excluded from the present invention in view of its odor generating properties and mechanical properties. In addition, as mentioned in the prior art, there is an example in which polystyrene is used as a prior art, but the present invention has been conceived as a problem of generating harmful gas to reveal the conventional problem, and this should also be excluded.

Polypropylene or polyethylene is a representative thermoplastic resin, has excellent extrudability, excellent foamability, does not produce odor after processing, and does not generate harmful gases during combustion.

In the present invention, the thermoplastic resin is added in consideration of extrudability and moldability.

In addition, the water content is limited in the present invention, water is added for bonding between chaff and starch when mixing, limited to the amount remaining by evaporation and drying in the drying process during manufacturing, it can contribute to flame retardancy while maintaining the shape as a molded body It is defined as the minimum range that exists.

In addition, in this invention, 2.5-7.5 weight part of aluminum hydroxide, magnesium hydroxide, or a mixture thereof can be further added as an inorganic flame retardant with respect to 100 weight part of foam insulations which consist of such a composition.

At this time, aluminum hydroxide is an amphoteric hydroxide which is a hydroxide of aluminum, which tends to solidify as it gels after prolonged contact with water. Is added.

In addition, magnesium hydroxide is a hydrate of magnesium, but does not react with water, but since this component also has antacid properties, it is used in the present invention as an inorganic flame retardant for increasing flame retardancy.

They may each be added 2.5-7.5% by weight alone, and may be added in a mixed state, preferably mixed at a weight ratio of 1: 1 when mixed.

In this case, it is preferable that the inorganic flame retardant is limited so that the expanded graphite: inorganic flame retardant is added in a weight ratio of 1: 1-2: 1 when compared with the amount of expanded graphite which performs the main flame retardant function.

Hereinafter, the flame retardant foam insulation manufacturing method according to the present invention will be described.

First, a mixing step of mixing chaff meal and starch in the above-mentioned ratio is performed.

At this time, chaff and starch should be sufficiently mixed in a blender for 20 minutes or more.

When the first mixing step is completed, a stirring step is performed in which water is poured into the blender and stirred for at least 20 minutes, thereby mixing the mixed powder to become a semi-solid state having a viscosity.

In this way, when chaff powder and starch are sufficiently stirred to become viscous, flowable, and extruded semi-solid state, a base resin, that is, a polypropylene resin or a polyethylene resin is added thereto, and then an additive is added to sequentially add expanded graphite as a flame retardant. Step is performed.

In this case, if the inorganic flame retardant is further added, the expanded graphite is added, mixed and then added again, which is to induce stabilization by allowing the expanded graphite to be sufficiently stirred and then input the inorganic flame retardant which is a subsidiary material. .

When the addition of the additives is completed, an extrusion process of mixing in a mixer for 30 minutes or more and sufficiently stirring and extruding the stirred mixture with a pellet extruder is performed.

Thereafter, the pellets produced through the extrusion process are dried at room temperature to carry out a drying step of maintaining the water content of 10% or less.

Finally, the foamed molding step is carried out by putting the dried pellets into the foaming extruder and foaming by steam pressure while adding steam to produce a flame-retardant foam insulation having a water content of 10 to 15%.

By doing so, it becomes possible to easily manufacture the flame-retardant foam insulation in accordance with the present invention.

Hereinafter, examples will be described.

Example 1

For the flame retardancy test of the foam insulation according to the present invention, the above-mentioned manufacturing method to be composed of 35% by weight, 12% by weight of expanded graphite, 53% by weight of polypropylene resin mixed with chaff and starch in a weight ratio of 1: 1 According to the foam insulation specimen was prepared.

At this time, the expansion start temperature of the expanded graphite was 250 ℃, the particle size is 80 mesh, the expansion ratio is 200 cm 3 / g, the purity was contained under the condition containing 95% carbon.

In addition, the moisture content of the specimen was maintained to be 12%.

In order to evaluate the flame retardancy of the fabricated specimens, a flame retardancy test was conducted according to the test method for flame retardancy of the interior materials and structures of buildings (KS F2271).

As a result, even if the flame was received as a front surface, the flame retardancy according to the flame retardant class 3 was formed by the formation of a fireproof layer by the porous carbide core on the film of the specimen.

In addition, there was no abnormality as a result of confirming the presence of harmful gases generated by the flame, and the toxic smell.

[Example 2]

For the flame retardancy test of the foam insulation according to the invention, 35% by weight of the mixture of chaff and starch in a weight ratio of 1: 1, 12% by weight of expanded graphite, 47% by weight of polypropylene resin, 6% by weight of aluminum hydroxide According to the manufacturing method described above to prepare a foam insulation specimen.

At this time, the expansion start temperature of the expanded graphite was 250 ℃, the particle size is 80 mesh, the expansion ratio is 200 cm 3 / g, the purity was contained under the condition containing 95% carbon.

In addition, the moisture content of the specimen was maintained to be 12%.

In order to evaluate the flame retardancy of the fabricated specimens, a flame retardancy test was conducted according to the test method for flame retardancy of the interior materials and structures of buildings (KS F2271).

As a result, even in this case, the flame retardancy was similar to that of the flame retardant class 3, and there was no abnormality as a result of confirming the presence of noxious gas generated by the flame and the toxic smell.

Through such an embodiment, it was possible to add flame retardancy to the existing general foam insulation, and also to have a flame retardancy equal to or higher than that of expensive flame retardant foam insulation, and to be manufactured at low cost, so that the value of use in the industry is large in the future. It is expected to be.

Claims (7)

delete delete delete delete delete 30-40% by weight of either starch meal or bamboo flour mixed with starch; Expanded graphite 5-15% by weight; In the method for producing a flame-retardant foam insulation is composed of the remaining polypropylene resin, the moisture content is maintained at 10-15%;
The mixed powder is mixed with the chaff powder or bamboo flour and starch in a blender at a weight ratio of 1: 1-1: 3;
When the mixing step is completed, add water to the blender and stir for 20-30 minutes to mix the mixture into a viscous semi-solid state having a viscosity;
When the stirring is completed, the addition step of adding a polypropylene resin, and sequentially adding expanded graphite;
When the addition of the additives is completed, the mixing step for 30-40 minutes in a mixer, and extruding the mixed mixture by a pellet extruder pelletizing step;
A drying step of drying the pellets produced by the extrusion process at room temperature to maintain a water content of 10% or less;
Fire-retardant foam insulation material comprising a dried pellets into a foaming extruder and foaming by steam pressure while adding water vapor foaming step of manufacturing a flame-retardant foam insulation having a water content of 10 to 15%; Way.
The method of claim 6, further comprising:
In the extrusion processing step, a flame retardant foam insulation manufacturing method characterized in that the step of further mixing the inorganic flame retardant of any one of aluminum hydroxide, magnesium hydroxide, aluminum hydroxide and magnesium hydroxide mixture after mixing with a mixer is further performed. .