KR20170002016A

KR20170002016A - Method and compositions of the polyurethane product and flame-retardant insulation is rigid polyurethane foam excellent supplement.

Info

Publication number: KR20170002016A
Application number: KR1020150091850A
Authority: KR
Inventors: 한상빈
Original assignee: 거성우레탄(주)
Priority date: 2015-06-29
Filing date: 2015-06-29
Publication date: 2017-01-06

Abstract

The present invention relates to a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulation properties of a urethane product, which comprises isocyanate and a polyol which are main components of a urethane foam and contains a foaming agent, a flame retardant, a foaming agent, It is possible to improve the flame retardancy of polyurethane by satisfying all the requirements of low harmfulness, low ductility, low corrosion resistance, and heat resistance, so as to minimize the loss of life and economic loss caused by urethane foam when fire occurs. And to a method and a composition for producing an excellent rigid polyurethane foam having improved heat insulation.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulation property of a urethane product.

The present invention relates to a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulation properties of a urethane product, and a method for producing the same, The present invention relates to a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulating properties.

Polyurethane is a polymer compound (polymer) which realizes various physical properties and functionalities by mixing an isocyanate, which is an organic compound, with a polyol and adding an additive or the like. From the use of its physical properties and functionality, it can be used for clothing, frames, camera bodies, furniture, shoes, construction materials (insulation, waterproofing, molding), automobiles, electronics and industrial materials, It is deep and wide. There are still many new polyurethane applications being developed and will continue to do so.

However, it is vulnerable to fire due to low ignition point in case of fire, ignited fire does not go out, it is spread to bigger fire, and fire burning space is created, resulting in additional loss due to load, Flame retardants must be provided to achieve high firefighting requirements.

Flame retardant additives are therefore often used to reduce the risk and severity of polyurethane foam burning.

A wide variety of flame retardants are known and commercially available for this purpose. However, there are often significant technical and toxic concerns that limit the use of these flame retardants.

Therefore, conventionally, the flame retardant performance of the urethane foam was improved by using a halogen-based flame retardant or a phosphorus flame retardant, a carbonization swelling agent, and a two-stage pyrolysis swelling agent in the production of urethane foam.

However, examples of phosphorus containing flame retardants used in the manufacture of flame retardant polyurethanes, including halogenated and non-halogenated phosphorus esters, include tris (chloroethyl) phosphate; Tris (chloropropyl) phosphate; 2,2-bis (chloromethyl) trimethylene bis (bis (2-chloroethyl) phosphate); Dimethyl methylphosphonate; Triethyl phosphate, and equivalents thereof.

Halogen-free flame retardant systems are in principle preferred due to environmental hazards reasons and also due to their excellent performance in terms of smoke density and smoke toxicity associated with fire.

In addition, the halogen-based flame retardant has a low degree of improvement in the flame retardant effect and a great burden of increasing the manufacturing cost.

The phosphorus flame retardant has a problem that the cured foam has a deteriorated flame retardancy in the long term.

In order to secure the flame retardant performance, the foamed foam is turned off due to its own weight in the urethane foam foaming process when a large amount of mixture is applied in order to secure the flame retardant performance.

In order to secure the flame retardant property of the urethane foam, there is a method of adding a sodium silicate liquid phase. However, since it has a strong alkali property and a large amount of water, the foaming rate rapidly increases when the urethane foam is foamed due to the sodium silicate liquid phase, .

Also, since the sodium silicate liquid phase has low water resistance even after drying and curing, there is a problem that the urethane foam foam has elution of strong alkali when exposed to moisture, thereby affecting the environment.

That is, polyurethane is an organic material and is vulnerable to fire. One example is the mention of polyurethane in a large fire, such as in a frozen warehouse. In addition, various noxious gases are generated depending on the fire condition and environment.

On the other hand, carbon monoxide gas is known to be much more dangerous to human life in case of fire. However, above all, the prevention of fire is the most important thing to prevent fire, and the increase of flame retardancy of polyurethane has been focused on related research and industry.

In order to improve the flame retardancy of the polyurethane, a flame retardant structure is introduced or a flame retardant is used. Flame retardants should meet both low hazard, low flammability, low corrosion and heat resistance.

The present invention therefore aims to realize the need for means for producing flame retardant polyurethane foams using an effective flame retardant.

The present invention relates to a method and a composition for producing rigid polyurethane foam excellent in flame retardancy and heat insulation property of urethane product

It is characterized in that isocyanate and polyol, which are the main components of urethane foam, are contained and include blowing agent, flame retardant, foam stabilizer, chain extender, solvent and catalyst.

The polyol contains a polyether polyol, which is a polymer of an alkylene oxide, and a short glycol.

The isocyanate may be contained in an amount of 5 to 35% by weight. It is more preferable that the isocyanate is contained in an amount of 11 to 22% by weight.

It is preferable to contain 5 to 15% by weight of the polyether polyol and 5 to 10% by weight of shot glycol, 8 to 12% by weight of polyether polyol and 3 to 7% by weight of shot glycol More preferable.

2.5 to 12% by weight of the blowing agent may be contained. It is more preferable that the foaming agent is contained in an amount of 5 to 10% by weight.

15 to 30% by weight of the flame retardant may be contained. It is more preferable that the flame retardant is contained in an amount of 20 to 25% by weight.

0.5 to 3% by weight of the foam stabilizer may be contained. It is more preferable that the foaming agent is contained in an amount of 1 to 2% by weight.

0.1 to 1.5% by weight of the chain extender may be contained. It is more preferable that the chain extender is contained in an amount of 0.5 to 1% by weight.

5 to 15% by weight of the solvent may be contained. It is more preferable that the solvent contains 8 to 12% by weight.

The amount of the catalyst composition may be 0.01 to 5% by weight. It is more preferable that the amount of the catalyst composition is from 1 to 3% by weight. The present invention relates to a method and a composition for producing rigid polyurethane foam excellent in flame retardancy and heat insulating property of a urethane product comprising the above-mentioned contents.

The present invention relates to a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulation property of a urethane product, and is characterized by satisfying all of the low harmfulness, low ductility, low corrosion resistance and heat resistance to improve the flame retardancy of the polyurethane, The present invention relates to a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulation properties of a urethane product which can be obtained by minimizing personal injury and economic loss due to urethane foam.

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

Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings, and the inventor should properly define the concept of the term to describe its invention in the best possible way It should be construed as meaning and concept consistent with the technical idea of the present invention.

Therefore, the scope of the present invention should not be construed as being limited to the above-described embodiments, and the scope of the present invention is not limited thereto. It will be understood by those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention.

The present invention will be described in detail in a method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulation properties of a urethane product.

The amount of the catalyst composition may be 0.01 to 5% by weight. It is more preferable that the amount of the catalyst composition is from 1 to 3% by weight. And is composed of the above-mentioned contents.

As the isocyanate compound, methylene diphenyl isocyanate (MDI) or the like is used.

It is preferable to select at least one of 1MDI to 4MDI and most preferably 2MDI to use isocyanate.

The isocyanate is used in an amount of from 5 to 35% by weight. When the amount is less than 5% by weight, foaming foam is difficult to form. When the amount is more than 35% by weight, the curing property of the foam is low.

The isocyanates may be any of the known aliphatic, alicyclic and aromatic types and mixtures of at least two of these types, and the organic isocyanates may be used alone or in combination with two or more of the same or different types Many can be used in combination. Thus, isocyanates customarily used in the manufacture of polyurethane foams may be used.

The polyether polyol is a raw material for urethane bonding reaction with isocyanate. The polyether polyol is prepared by adding propylene oxide (PO) or ethylene oxide (EO) to an initiator having two or more active hydrogen (hydroxyl -OH, amine group -NH2) do. The polyether polyol is used in an amount of from 5 to 15% by weight. When it is less than 5% by weight, foaming foam is difficult to form, and when it is more than 15% by weight, micropore formation characteristics are deteriorated due to rapid foaming.

The polyol is not usually limited as long as it is used in the production of a rigid polyurethane foam. Specifically, an ester-type polyol and an ether-type polyol can be used. In terms of flame retardance, an ester-type polyol is excellent, and in terms of water resistance and flexibility, an ether-type polyol is excellent. Polyol The number of hydroxyl groups contained in one molecule is 2 to 6, and the proper ratio is used.

The numerical value of the number of hydroxyl groups per weight of the polyol is expressed by the value of OH value. This value should be adjusted to an appropriate level to obtain a good urethane property. If this value is too small, the amount of MDI used becomes relatively small, so that the flame retardancy becomes insufficient. If this value is too large, the amount of polyol which gives flexibility of the urethane becomes small,

A problem of shrinkage occurs. In the production of hard urethane foam, the average OH value is preferably about 250 to 500 mg KOH / g.

On the other hand, NCO / OH, which is an equivalent ratio of the number of hydroxyl groups to the number of isocyanates, is expressed by a value of NCO index, which is also an important factor determining the physical properties of the urethane. If the value is larger than 1, it means that the free isocyanate containing no urethane bond is included, and finally, the isocyanate reacts with the isocyanurate to form isocyanurate.

In rigid polyurethane foam, this value will have a value of 1.0 to 5.0, and when it is 4.0 or more, sufficient flame retardancy is obtained without addition of a flame retardant and is usually called PIR (Polyisocyanurate). This NCO

PIR with index value is shrunken and shrinkage is serious, and products having a value of about 2.0 to 2.5 in the market are distributed in a state in which flame retardancy is insufficient.

Further, a flame retardant may be added to complement the flame retardancy, and a flame retardant such as a bromine-based, inorganic, phosphorus-based or nitrogen-based flame retardant may be added.

The double bromine system has a problem that toxic gas is generated in a fire and causes suffocation by suffocation, and dioxin is generated when incinerating waste, which is avoided. The remaining inorganic, phosphorus and nitrogen flame retardants can be used, and they are generally used in combination to obtain a synergistic effect rather than a single use. In addition to the above-mentioned flame retardant, expandable graphite having a high expansion ratio may be used to block heat during a fire.

The polyols may be any compound that contains at least two functional groups that react with isocyanates to make the polyisocyanurate. These functional groups include at least one active hydrogen atom, such as that defined by the Zerewittinoff reaction. The active hydrogen atom is generally a hydrogen atom bonded to an oxygen, nitrogen or sulfur atom, and is preferably a hydrogen atom of a hydroxyl group.

Suitable polyols include aliphatic, monosaccharides, or aromatic compounds having two or more hydroxyl groups in the molecule and mixtures thereof such as polyether polyols, polyester polyols, and castor oil, But is not limited thereto.

These polyols commonly used in the production of polyurethane foams can be used.

The blowing agent promotes the curing reaction between the isocyanate and the polyether polyol. In the present invention, at least one selected from water, a carboxylic acid, a fluorocarbon type foaming agent, and carbon dioxide can be used, and the content is 2.5 to 12 wt% And a low density of the polyurethane foam can be achieved. If the amount is less than 2.5% by weight, the effect of promoting foaming is insignificant. If the amount is more than 12% by weight, bubbles are combined with each other to form large bubbles, which makes it difficult to form homogeneous pores.

Such blowing agents are hydrocarbon blowing agents such as linear or branched alkane hydrocarbons such as butane, isobutane, 2,3-dimethylbutane, n- and isopentane and technical-grade pentane mixtures, n - and isohexanes, and n- and isoheptanes. Other blowing agents may be used with one or more hydrocarbon blowing agents; These are chemically active blowing agents that chemically react with isocyanate or other formulation components to release gas for foaming and as a gas at substantially exothermic foaming temperatures without the need to chemically react with the foam components to provide a foaming gas It can be divided into existing physically active blowing agents.

Gases that are not thermally stable and degrade at elevated temperatures are included within the meaning of physically active blowing agents. Examples of chemically active blowing agents are those which react with isocyanate to liberate gas, e.g., CO2. Suitable chemically active blowing agents include, but are not limited to, water, mono- and polycarboxylic acids (having a molecular weight of 46 to 300), salts of these acids, and tertiary alcohols.

Water can be used as a co-blowing agent with a hydrocarbon blowing agent. The water reacts with the organic isocyanate to liberate CO2 gas, the actual blowing agent. However, because water consumes isocyanate groups, an equivalent molar excess of isocyanate should be provided to compensate for the spent isocyanates.

Organic carboxylic acids used as chemically active blowing agents include, but are not limited to, aliphatic mono- and polycarboxylic acids such as dicarboxylic acids. Other organic mono- and polycarboxylic acids may also be used in the present invention.

The flame retardant is a raw material for adding flame retardancy to a polyurethane foam. In the present invention, it is proposed to use a low-melting vinylsilicate soda flame retardant, an absorbent polymer flame retardant, a layered mineral flame retardant, and a metal oxide flame retardant.

Particularly, it is proposed to include a low-solubility vinyl silicate soda flame retardant coated with a PVA (polyvinyl alcohol) and a water absorbent polymer flame retardant in addition to a layered mineral flame retardant and a metal oxide flame retardant .

Sodium silicate flame retardant with low solubility is PVA (polyvinyl alcohol) coated on hydrophobic surface treated siliceous soda powder. Sodium silicate dissolves and cures by fire or heat to form a network structure having silicon component, The PVA solution treated in the sodium silicate powder dissolves in the water, and when the sodium silicate powder present in the cured polyurethane foam is hydrophobic Even when the polyurethane foam is exposed to external moisture by the surface, there is no change in shape and the strong alkali is prevented from being eluted, thereby exhibiting water resistance.

When the content of the vinyl silicate soda flame retardant is less than 10% by weight, the flame retardant effect deteriorates due to a low network structure formation property. When the content is more than 15% by weight, the powdery content is excessive, It is easy to occur.

The water absorbent polymer flame retardant is dispersed in the urethane foam cured in a state of absorbing water, so that the absorbed water is vaporized at the time of the fire to be a raw material for realizing the flame retardant performance, and the silicate polyacrylate is preferably adopted.

The water absorbing polymer flame retardant is used in an amount of 5 to 10% by weight, and less than 5% by weight is only a small amount of moisture absorption, so that the flame retardant effect is insufficient in case of fire. When the amount is more than 10% by weight, the urethane foam has a high viscosity due to excessive moisture absorption, There is a possibility that an off phenomenon may occur.

The layered mineral flame retardant is employed in a range that does not affect the mechanical properties of foamed urethane foam such as a halogen-based or phosphorus-based material, and aluminum hydroxide or magnesium hydroxide is preferably employed. The layered mineral flame retardant is used in an amount of 8 to 10% by weight. When the amount is less than 8% by weight, the flame retardant effect is insignificant. If the amount is more than 10% by weight, the urethane foam has a high weight, which causes a foam off phenomenon and affects the physical properties of the urethane foam.

The metal oxide flame retardant is used as a raw material for adding flame retardancy, and it is used in the range of 2 to 5 wt% as 1 to 2 metal oxide powder such as AlO, BaO, and ZnO. If the amount is less than 2% by weight, the flame retardant effect is insufficient. If the amount is more than 5% by weight, a foam off phenomenon tends to occur due to an increase in the weight of the urethane foam.

Further, metal compounds such as organic phosphoric acid esters, halogen-containing compounds and aluminum hydroxide can be mentioned, and organic phosphoric acid esters are particularly preferable because they have a viscosity lowering effect of the polyol composition.

Examples of the organic phosphate esters include halogenated alkyl esters of phosphoric acid, alkylphosphoric esters, arylphosphoric esters, and phosphonic acid esters.

Specific examples thereof include tris (chloropropyl) phosphate (TMCPP, manufactured by Daihachi Chemical), tributoxyethyl phosphate (TBEP), tributyl phosphate, triethyl phosphate, trimethyl phosphate and cresylphenyl phosphate. The blending amount of the flame retardant is preferably 15 to 30% by weight, more preferably 20 to 25% by weight, based on 100% by weight of the polyurethane foam. It is also preferable that the flame retardant is contained in an amount of 15% by weight or more because the brittleness of the foam can be prevented from deteriorating.

The flame retardant of the present invention is a halogen-free ester compound that is substantially free of isocyanates, i.e., does not have any active hydrogen-containing groups such as hydroxyl, mercapto, amino and carboxylic acid groups.

For economic and manufacturing reasons, the alkyl phenylphosphate esters of the present invention can often be used as mixtures that do not significantly affect product performance.

Examples of the foaming agent include graft copolymers of polyoxyalkylene glycol and polydimethylsiloxane, which are polymers of ethylene oxide and propylene oxide, among known foaming agents for rigid polyurethane foam, and oxyethylene groups in polyoxyalkylene And a silicone content of 70 to 100 mol% is preferably used. The foam stabilizer is used in an amount of 0.5 to 3 wt% in order to adjust the structure of the urethane foam by improving the miscibility by lowering the surface tension and uniformizing the size of the generated foam. When the foam stabilizer is less than 0.5 wt%, the surface tension is high, And if it is more than 3% by weight, the residual rate of the internal pores is lowered, and the foam shrinkage phenomenon easily occurs.

The foam stabilizer eliminates the bubbles generated during the mixing process and smoothes the diffusion during the formation of the foam. In order to give the above characteristics, the surface tension should be lowered, and the silicon compound is widely used because it conforms to this characteristic.

The present invention relates to the production of composite panels, in which urethane foam has to pass between EPS beads that take up preliminary positions. Therefore, it is preferable to keep the use amount of the silicone foam stabilizer high because the resistance is relatively large as compared with the production of a single urethane foam. The use of the silicone foam stabilizer is preferably as high as 1.5 to 3.0% by weight based on 100% by weight of the polyol. If it is used in an amount less than 1.5% by weight, there is a problem that urethane is not evenly distributed due to a high resistance, and when it is used in an amount exceeding 3.0% by weight, there is a problem that economical efficiency becomes insufficient.

The chain extender is intended to make a chain or network structure with a chain of polymers.

The chain extender is used in an amount of from 0.1 to 1.5% by weight. When it is less than 0.1% by weight, it is difficult to form a network structure. When the content of the chain extender exceeds 1.5% by weight, viscosity becomes high.

The solvent is used for mixing the powder raw materials and for decreasing the viscosity, and PC (propylene carbonate) is preferably used in the present invention. The solvent is used in an amount of from 5 to 15% by weight, and if it is less than 5% by weight, the viscosity after blending is too high to form a smooth foam, and if it exceeds 15% by weight, the viscosity is lowered.

The amount of the catalyst composition is preferably 0.01 to 5% by weight. It is more preferable that the amount of the catalyst composition is from 1 to 3% by weight.

When the isocyanate compound is mixed with the isocyanate compound in the above content range, the cream time is 30 to 90 seconds, the gel time is 60 to 120 seconds, and the tack free time is about 90 to 150 seconds, , Thermal conductivity, compression and flexural strength, and as a result, the flame-retardant rigid polyurethane composite insulation material of the present invention can be produced.

The catalyst composition is not particularly limited as long as it is a catalyst promoting the urethanization reaction, but preferably a reactive amine catalyst capable of reacting with an isocyanate group of the polyisocyanate component is used.

Examples of such reactive amine catalysts include N, N-dimethylethanolamine, N, N-dimethylaminoethoxyethanol, N, N, N'-trimethylaminoethylethanolamine, N, N, 2-hydroxypropylenediamine, N-hydroxyethylmorpholine, N-methyl-N-hydroxyethylpiperazine, N, N-dimethylpropylenediamine and the like.

As the tertiary amine catalyst, an N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylhexamethylene Diamine, N, N, N ', N', N "-pentamethyldiethylenetriamine, diazabicyclo undecene, N, N-dimethylcyclohexylamine, triethylenediamine, N- have.

The use of catalysts is indispensable for the production of rigid urethane foams. The catalyst used for urethane is generally used in the form of a tertiary amine and a tin carboxylate, either singly or in combination.

The catalysts of the present invention comprise a combination of standard tertiary amine and organometallic polyurethane catalysts. Any of a number of polyurethane catalysts can be used to make the polyurethane foam. Typical levels are from about 0.001 to 5% based on the weight of the reaction mixture. Levels from about 0.001 to about 2 php are common. Relative ratios are well known to those of ordinary skill in the art.

As the tertiary amine, pentamethyl diethylene triamine, dimethyl cyclohexylamine and triethylene diamine are diluted with diol and the like, and polymerization reaction and crosslinking reaction are greatly promoted Thereby accelerating the cream time and enhancing the physical properties of the foam.

Therefore, a tertiary amine is inevitably used for producing a rigid urethane foam. In the case of securing the time required for physical dispersion as in the present invention, it is difficult to use the conventional catalyst. Therefore, the conventional catalyst composition can not be used.

In order to uniformly mix the urethane, it is important to secure the time required for mixing. The usual urethane foaming rate can be determined first by a cream time. During the production of a conventional rigid urethane foam, this time is about 10 seconds or so, and a slight change occurs depending on the ambient temperature and the influence of the catalyst .

The higher the temperature, the higher the catalyst activity and the greater the catalyst usage, the faster the cream time. The time of 10 seconds is a time which is insufficient to physically mix the mixture evenly, and it takes at least 30 seconds or more. If the amount of catalyst used is simply reduced to secure this time, the compressive strength and flexural strength of the resulting foam are undesirably low.

The molar ratio of the carboxylic acid to the tertiary amine is preferably 0.2 to 4.0, more preferably 0.5 to 2.5. If the molar ratio is less than 0.2, the effect of delaying the cream time of the catalyst is undesirable because it is too small. If the molar ratio exceeds 4.0, the delay time becomes too long and the workability is deteriorated.

The above cream time is the best at 70 seconds or more, specifically 70 to 90 seconds, and the hard polyurethane foam is excellent in interfacial adhesion so that no cracking occurs and the heat insulating property is improved.

The (C1-C18) carboxylic acid may be any one selected from the group consisting of formic acid, acetic acid, propionic acid, benzoic acid, oleic acid and stearic acid. Or a mixture of two or more thereof.

At this time, it is preferable to use the catalyst composition of the present invention, and it is preferable that the catalyst composition for preparing a hard urethane foam is contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the polyol. When the isocyanate compound is mixed with the isocyanate compound in the above content range, the cream time is 30 to 90 seconds, the gel time is 60 to 120 seconds, and the tack free time is about 90 to 150 seconds, , Thermal conductivity, compression, and flexural strength.

And is not limited as long as it is usually used in the production of the rigid polyurethane foam.

Claims

It contains isocyanate and polyol, which are the main components of urethane foam, and is composed of a foaming agent, a flame retardant, a foam stabilizer, a chain extender, a solvent and a catalyst.
The polyol contains a polyether polyol which is a polymer of an alkylene oxide and a short glycol.
The isocyanate may be contained in an amount of 5 to 35% by weight. It is more preferable that the isocyanate is contained in an amount of 11 to 22% by weight.
It is preferable to contain 5 to 15% by weight of the polyether polyol and 5 to 10% by weight of shot glycol, 8 to 12% by weight of polyether polyol and 3 to 7% by weight of shot glycol More preferable.
2.5 to 12% by weight of the blowing agent may be contained. It is more preferable that the foaming agent is contained in an amount of 5 to 10% by weight.
15 to 30% by weight of the flame retardant may be contained. It is more preferable that the flame retardant is contained in an amount of 20 to 25% by weight.
0.5 to 3% by weight of the foam stabilizer may be contained. It is more preferable that the foaming agent is contained in an amount of 1 to 2% by weight.
0.1 to 1.5% by weight of the chain extender may be contained. It is more preferable that the chain extender is contained in an amount of 0.5 to 1% by weight.
5 to 15% by weight of the solvent may be contained. It is more preferable that the solvent contains 8 to 12% by weight.
The amount of the catalyst composition may be 0.01 to 5% by weight. It is more preferable that the amount of the catalyst composition is from 1 to 3% by weight. A method and a composition for producing a rigid polyurethane foam excellent in flame retardancy and heat insulating properties of a urethane product comprising the above-mentioned contents.