KR20080082172A - Thermoplastic polyurethane having good self-extinguishing property and their preparation - Google Patents

Abstract

A self-extinguishing thermoplastic polyurethane, and a method for preparing the thermoplastic polyurethane are provided to improve self-extinguishing property. A self-extinguishing thermoplastic polyurethane comprises an organic diisocyanate; a long chained diol; if necessary, a short chained diol as a chain extender; and a mixture of red phosphorus and melamine cyanurate as a flameproofing agent. Preferably the content of red phosphorus and melamine cyanurate is 1-11 parts by weight and 10-50 parts by weight, respectively, based on 100 parts by weight of the total solid part of the diisocyanate and the diol. Preferably the thermoplastic polyurethane comprises further a liquid organic phosphate compound as a processing aid.

Description

Thermoplastic polyurethane having good self-extinguishing property and their preparation method

The present invention relates to a thermoplastic polyurethane and a method for producing the same, and more particularly, to a thermoplastic polyurethane having a self-extinguishing property or flame retardancy and a method for producing the same.

Polymers, commonly referred to as polyurethanes or urethane polymers, have a fairly wide range of applications. In terms of its use, it is no exaggeration to say that it is commonly used in almost all fields of polymer materials such as elastomers, flexible foams, rigid foams, plastics, paints, adhesives, fibers, and synthetic leathers.

In terms of structure, it is not valid to call all products polyurethane. In general, urethane groups are rather small compared to other structural units, and the structure of the portion other than the urethane group varies widely. Due to the variety of structures, the properties of urethane polymers are varied, which enables a wide range of applications and complicates the structural relationship of polyurethanes.

Among them, thermoplastic polyurethane (hereinafter referred to as TPU) is very important in the industry because of its excellent elastomeric properties and thermoplastic processability. An overview of the manufacture, properties and uses of TPUs is well known in the literature (eg Kunststoff Handbuch, G. Becker, D. Braun, volume 7 "Polyurethane", Munich, Vienna, Carl Hanser Verlag. 1983). ).

The TPU may basically comprise a three component compound, which may include organic diisocyanates; A long-chain diols such as polyester diols, polyether diols, polycarbonate diols, and the like; And A short-chain diols, usually difunctional alcohols (ie, chain extenders). TPU can be prepared continuously or discontinuously using such compounds.

Such thermoplastic polyurethanes are inherently flammable as in most plastics, and in this regard, stability to flame, that is, flame retardancy is often required.

Halogen-based organic compounds have been used as flame retardants to meet these demands, but halogen-based flame retardants have problems such as large amounts of smoke during combustion and corrosion of metals.

To this end, efforts have been made to use flame retardants that do not contain any halogen compounds. For example, U.S. Patent No. 5,837,760 uses organic phosphate and / or organic phosphonate as a flameproofing agent. Thermoplastic polyurethanes with a mixture of melamine cyanurates are described.

However, when a mixture of organic phosphate and / or a mixture of organic phosphonate and melamine cyanurate is applied, there is a problem of insufficient flame retardancy.

The present invention is to provide a thermoplastic polyurethane having excellent self-extinguishing property.

In one embodiment of the present invention, a thermoplastic polyurethane having excellent self-extinguishing properties including organic diisocyanates, long-chain diols and, if necessary, short-chain diols as a chain extender and a mixture of sulfur and melamine cyanurate as a flame retardant. To provide.

In the thermoplastic polyurethane according to one embodiment of the present invention, red may be included in an amount of 1 to 11 parts by weight based on 100 parts by weight of the total solid content of diisocyanates and diols based on a pure content.

In the thermoplastic polyurethane according to one embodiment of the present invention, melamine cyanurate may be included in an amount of 10 to 50 parts by weight based on 100 parts by weight of the total solid content of diisocyanates and diols.

Another embodiment of the present invention provides a thermoplastic polyurethane further comprising a liquid organic phosphate compound as a processing aid.

In the thermoplastic polyurethane according to one embodiment of the present invention, the liquid organic phosphate compound is at least one selected from cresyl diphenyl phosphate, bisphenol-A bis (diphenyl phosphate) and resorcinol bis (diphenyl phosphate). It may be.

In the thermoplastic polyurethane according to one embodiment of the present invention, the liquid organic phosphate compound may include 5 to 15 parts by weight based on 100 parts by weight of the total solid content of diisocyanates and diols.

In one embodiment of the present invention, a process comprising reacting an organic diisocyanate and a long chain diol and optionally a chain extender with a mixture of red and melamine cyanurate and optionally reacting in the presence of a catalyst Provided is a method for producing a thermoplastic polyurethane having excellent digestibility.

Another embodiment of the present invention is a process for preparing a polyurethane by polymerizing a composition comprising organic diisocyanates and long chain diols and, if necessary, a chain extender, in the presence of a catalyst, if necessary; And compounding an additive comprising a mixture of red and melamine cyanurate to the polyurethane.

The present invention will be described in more detail as follows.

Polyurethane according to the present invention includes a mixture of red phosphorous and melamine cyanurate as a flame retardant, and may be used as it is, but may be used as a pretreatment as a part to improve stability. Various treatment methods are disclosed as a method of treating an enemy. For example, a method of coating an enemy with a thermosetting resin such as phenol, melamine, epoxy, or unsaturated polyester, and stabilizing the reaction with the water or oxygen on the surface of the enemy A method of granulating the enemy without forming a high fracture surface, a method of adding a small amount of aluminum hydroxide or magnesium hydroxide to the enemy and catalytically inhibiting oxidation of the enemy, coating the enemy with paraffin or wax to prevent contact with moisture. A method of inhibiting, a method of stabilizing by mixing with ε-caprolactam, etc., a method of precipitating and treating a red phosphorus with an aqueous solution of a metal salt such as copper, nickel, silver, iron, aluminum or titanium to precipitate and stabilize a metal phosphorus compound on the surface of the red phosphorus, Coating an enemy with aluminum hydroxide, magnesium hydroxide, titanium hydroxide, water, zinc oxide, and the like, Which may be mentioned iron, cobalt, nickel, manganese, and a method of electroless plating to cover stabilized by tin, and combinations of these methods, etc. on the surface.

In the pre-treatment products, the pure water may be contained at least 45% by weight or more, and the average particle size may be about 0.01 to 50 μm in terms of flame retardancy, mechanical strength and appearance, and particularly may be about 10 to 30 μm. Can be.

In the present invention, the addition amount of the droplets may be 1 to 11 parts by weight, in particular 5 to 8.5 parts by weight based on the total solid content of diisocyanates and diols, based on the pure content, to improve self-extinguishing. Herein, the total solids content of diisocyanates and diols refers to the total solids content of organic diisocyanates and long chain diols used in the preparation of the thermoplastic polyurethane of the present invention and short chain diols as chain extenders added as necessary. It can be defined as.

However, if only the enemy is applied as a flame retardant alone, it can satisfy the self-extinguishing property when used in excess, but since the drip occurs a lot during the combustion process, the combustion sparks show a lot of fall, which makes the transition of fire easier. There may be a problem, for this purpose melamine cyanurate is used in the present invention.

Melamine cyanurate has conventionally been used as a flame retardant such as thermoplastic polyurethane, but it is difficult to obtain improved self-extinguishing property only by using it alone.

The amount of melamine cyanurate added is 10 to 50 parts by weight based on the total solids content of diisocyanates and diols, which may lower the mechanical properties and express self-extinguishing properties compared to adding other phosphorus-based or inorganic flame-retardants. In this case, the addition amount may be 20 to 50 parts by weight, more preferably 30 to 40 parts by weight.

In general, thermoplastic polyurethanes are obtained by reacting organic diisocyanates with long-chain diols, and may include a chain extender as necessary.

First, as organic diisocyanates, aromatic, aliphatic and cycloaliphatic diisocyanate compounds can be used, for example, 2,4-toluylene diisocyanate, 2,6-toluylene diisocyanate, phenylene diisocyanate, 4 , 4'-diphenyl methane diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3'-dimethyl biphenyl-4,4'- diisocyanate, o-, m- Or diisocyanates such as p-xylene diisocyanate, tetra methylene diisocyanate, hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, dodecane methylene diisocyanate, cyclohexane diisocyanate and dicyclohexyl methane diisocyanate.

First of all, long chain diols for forming soft segments to impart flexibility in the production of thermoplastic polyurethane are not particularly limited, and may be polyester diols, polycaprolactone diols, polyether diols, polycarbonate diols, or mixtures thereof. Can be. Specifically, ethylene glycol, trimethylene glycol, tetramethylene glycol, hexene glycol, propylene glycol, and the like, adipic acid, succinic acid, glutaric acid, subberic acid, sebacic acid, etc. which are saturated aliphatic dicarboxylic acids having 4 to 10 carbon atoms; Condensates obtained from phthalic acid, isophthalic acid, terephthalic acid and the like which are aromatic dicarboxylic acids; Copolymers of alkylene glycols with lactone groups and thus obtained polyester glycols such as polylactone diols, polycaprolactone diols, and the like; Or condensates of alkylene oxides having 2 to 4 carbon atoms; Condensates of alkylene oxides having 2 to 4 carbon atoms with alkylene glycols; Polyalkylene glycols having 2 to 4 carbon atoms; Polyalkylene ether glycols obtained by ring-opening polymerization of tetrahydrofuran and the like; Dihydroxy polyalkylenes; Or hydroxy polycarbonates can also be used.

More specifically, polytetramethylene ether glycol, dihydroxy polyethylene adipate, polyethylene glycol, polypropylene glycol, etc. are mentioned.

Such long chain diols may have a weight average molecular weight of about 500 to about 8000, and another example may be about 500 to about 2800.

Meanwhile, if necessary, short chain diols may be included as a chain extender. Examples thereof include saturated aliphatic glycols having 2 to 6 carbon atoms, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and butane 1 , 2-diol, butane 1,3-diol, butane 1,4-diol, butane 2,3-diol, butane 2,4-diol, hexane diol and the like, and 1,4-xylene which is an aromatic glycol Glycol, phenylene bis- (β-hydroxy ethyl ether), and the like.

In addition, for example, a small amount of trifunctional or higher alcohols such as trimetholpropane, glycerin, hexane triol and the like can be used simultaneously.

The content of long chain diols and chain extenders can be adjusted to obtain the required hardness and melt flow index. The hardness and melt viscosity increase with increasing chain extender content, while the melt flow index tends to decrease. Indicates.

For example, in order to satisfy the hardness level and the viscosity level suitable for coating the optical cable, the molar ratio of the long-chain diol and the chain extender may be adjusted to be about 1: 1 to 1:15, and another example may be 85 (Shore A) to 70 (Shore). In order to satisfy the hardness level and the viscosity level suitable for D), the molar ratio of the long chain diol and the chain extender may be adjusted to be about 1: 1.2 to 1:13.

Meanwhile, in the present invention, a liquid phosphate compound may be further added as a processing aid for preventing scattering during processing due to the use of an inorganic substance, but the addition of the liquid phosphate compound is directly involved in the improvement of self-extinguishing property. In addition, due to the characteristics of the liquid, it controls the hardness during processing and prevents the scattering of the powder. Such a liquid phosphate compound is not particularly limited as long as it is a liquid phosphate compound at room temperature. For example, cresyl diphenyl phosphate, bisphenol-A bis (diphenyl phosphate) or resorcinol bis (diphenyl phosphate). Etc. can be mentioned.

When the liquid phosphate compound is added, the addition amount may be any amount that can adjust the hardness of the thermoplastic polyurethane to about 85 (Shore A) to 70 (Shore D), particularly about 85 to 95 (Shore A). The diols may be 5 to 15 parts by weight based on 100 parts by weight of the total solid content.

In addition, the thermoplastic polyurethane according to the present invention may be used for the production of lubricants, hydrolysis stabilizers, light stabilizers, heat stabilizers, anti-pigmentation stabilizers, dyes, pigments, inorganic and / or organic fillers and reinforcing agents. Adjuvants and / or additives, such as, for example, may further include.

The preparation of the thermoplastic polyurethanes of the present invention, on the other hand, consists of long chain diols, organic diisocyanates and, if necessary, chain extenders, mixtures of red and melamine cyanurate as flame retardants and catalysts, if necessary, as described above. The reaction may be carried out in the presence of an adjuvant and / or additives, such that the equivalent ratio of the sum of the NCO group of the organic diisocyanate group and the hydroxyl group of the long chain diol and the chain extender is 0.99: 1 to 1.07: 1.

Another industrially more useful method is the compounding method, for example, from a composition comprising organic diisocyanates and long chain diols and, optionally, chain extenders, if necessary polymerized in the presence of a catalyst to The urethane may be prepared and then compounded with a mixture of red and melamine cyanurate alone or in a liquid organic phosphate compound. At this time, the auxiliary and / or additives described above may be further added during the polyurethane polymerization.

The thermoplastic polyurethane obtained may have a number average molecular weight of at least 100,000 to 400,000.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

Example 1

150 g polytetramethylene ether glycol (weight average molecular weight 1,000), 21.7 g butane 1,4-diol, melamine cyanurate 110 g, red (average particle size 10-30 μm, minimum content 85%, phenolic resin Coated) 22g was weighed in, stirred for 5 minutes and maintained at 80 ° C., 103.7g of 4,4′-diphenylmethane diisocyanate was added and stirred for 2 minutes to obtain a polymerization reaction.

The obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Example 2

150 g polytetramethylene ether glycol (weight average molecular weight 1,000), 21.7 g butane 1,4-diol, melamine cyanurate 137.5 g, red (average particle size 10-30 μm, low minimum 85%, phenolic resin) Coated with) 19.25g, 33g of cresyl diphenyl phosphate was metered in, and after stirring for 5 minutes and maintained at 80 ℃, 103.7g of 4,4'- diphenylmethane diisocyanate was added and stirred for 2 minutes A polymerization product was obtained.

The obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Example 3

A thermoplastic polyurethane specimen was obtained in the same manner as in Example 2 except using bisphenol-A bis (diphenyl phosphate) instead of cresyl diphenyl phosphate.

The obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Examples 4-6

Thermoplastic polyurethane specimens were obtained in the same manner as in Examples 1 to 3, except that polybutylene adipate glycol (weight average molecular weight 1,000) was used instead of polytetramethylene ether glycol.

Each obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Examples 7-12

Thermoplastic polyurethane specimens were obtained in the same manner as in Examples 1 to 6, respectively, except that the addition amounts of red and melamine cyanurate were added in a variable manner as shown in Table 1 below.

In the following Table 1, the addition amount is expressed as 'parts by weight' based on 100 parts by weight of the total solid content of diisocyanates and diols.

Each obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Addition amount (pure content) Melamine cyanurate addition amount Example 1 8 (6.8) 40 Example 2 7 (5.95) 50 Example 3 7 (5.95) 50 Example 4 8 (6.8) 40 Example 5 7 (5.95) 50 Example 6 7 (5.95) 50 Example 7 1 (0.85) 10 Example 8 3 (2.55) 25 Example 9 5 (4.25) 10 Example 10 6 (5.1) 40 Example 11 10 (8.5) 40 Example 12 12 (10.2) 40

Examples 13-24

Thermoplastic polyurethane specimens were obtained in the same content ratios as in Examples 1 to 12, except that the preparation method was changed as follows.

First, the organic diisocyanates and diols are reacted for 2 minutes to polymerize the polyurethane, and the compound of the present invention is added by compounding extrusion process by adding liquid and melamine cyanurate and a liquid organic phosphate compound as necessary. Polyurethane specimens were obtained.

Comparative Example 1

Thermoplastic polyurethane specimens were obtained in the same manner as in Example 1, except that 5 parts by weight of the total solid content of diisocyanates and diols was added without adding melamine cyanurate.

Each obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Comparative Example 2

A thermoplastic polyurethane specimen was obtained in the same manner as in Example 1, except that only 40 parts by weight of melamine cyanurate was added to 100 parts by weight of the total solid content of the diisocyanates and diols without addition of red.

Each obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Comparative Examples 3 to 14

Thermoplastic polyurethane specimens were obtained in the same manner as in Examples 1 to 12, except that 1,3-phenylene tetraxenyl phosphate was added in the same amount instead.

Each obtained polymerized product was pulverized and injected to prepare a specimen. The self-extinguishing evaluation was performed and the results are shown in Table 2 below.

Oxygen Index (%) Combustion test Primary Secondary 3rd 4th Example One 26.7 0 0 One 2 2 26 0 0 One 4 3 25.7 0 One 2 5 4 29 0 0 0 One 5 28.5 0 0 0 2 6 28 0 0 One 3 7 22 One 8 14 - 8 23 0 6 9 - 9 24 0 5 7 - 10 26.5 0 0 2 3 11 27 0 0 0 2 12 27.5 0 0 0 One 13 26.4 0 One 2 3 14 25.8 0 One 2 4 15 25.2 0 One 2 5 16 28.7 0 0 One 2 17 28.1 0 0 One 2 18 27.8 0 0 2 4 19 21.9 One 8 15 - 20 22.7 0 6 10 - 21 23.6 0 5 8 - 22 26.2 0 0 3 4 23 26.6 0 0 One 3 24 27.1 0 0 One 2 Comparison One 23.5 0 7 13 - 2 22 5 - 3 22 0 24 - 4 24 0 12 - 5 24 0 13 - 6 22 0 20 - 7 24 0 10 - 8 24 0 11 - 9 21 - 10 21 - 11 21 - 12 21.5 2 - 13 24 0 18 - 14 24 0 15 -

* Symbol (-): Indicates that the unit is not extinguished and continues to burn

Here, oxygen index was measured based on JISK7201. The fire extinguishing test was carried out by burning the lighter for 15 seconds and then checked the time taken for extinguishing the lighter after extinguishing the lighter.

From the results of Table 2, as in Examples 1 to 12, as the flame retardant containing a mixture of red and melamine cyanurate alone or melamine cyanurate alone, or a mixture of phosphate compounds and melamine cyanurate It can be seen that the self-extinguishing property is superior to the case. However, even if only the enemy alone, as in Comparative Example 1, if the addition amount is over a certain level, the self-extinguishability is improved to some extent, but when the specimen is melted by the drip during combustion, the spark falls. In case of fire, it is confirmed that there is a risk of transition spread.

Although not particularly shown in Table 2, in the case of including a liquid phosphate compound, such as cresyl diphenyl phosphate or bisphenol-A bis (diphenyl phosphate) in the examples there was no scattering during processing was excellent in processability .

Also in the embodiments using a mixture of red and melamine cyanurate, the red is 6 to 10 parts by weight based on 100 parts by weight of the total solid content of diisocyanates and diols and 30 to 50 parts by weight of melamine cyanurate In case of digestion test, the result was better.

According to the present invention described in detail above, it is possible to provide a thermoplastic polyurethane having improved self-extinguishing property by including red and melamine cyanurate as a flame retardant.

Claims (8)

A thermoplastic polyurethane comprising organic diisocyanates, long chain diols and, if necessary, short chain diols as chain extenders, A thermoplastic polyurethane having excellent self-extinguishing property, comprising a mixture of red and melamine cyanurate as a flame retardant. The thermoplastic polyurethane having excellent self-extinguishing property according to claim 1, wherein red is contained in an amount of 1 to 11 parts by weight based on 100 parts by weight of the total solid content of diisocyanates and diols based on a pure content. The thermoplastic polyurethane having excellent self-extinguishing property according to claim 1 or 2, wherein the melamine cyanurate is contained in an amount of 10 to 50 parts by weight based on 100 parts by weight of the total solid content of the diisocyanates and diols. The thermoplastic polyurethane having excellent self-extinguishing property according to claim 1, comprising a liquid organic phosphate compound as a processing aid. The liquid organic phosphate compound according to claim 4, wherein the liquid organic phosphate compound is at least one selected from cresyl diphenyl phosphate, bisphenol-A bis (diphenyl phosphate), and resorcinol bis (diphenyl phosphate). Thermoplastic polyurethane. The thermoplastic polyurethane having excellent self-extinguishing property according to claim 4 or 5, wherein the liquid organic phosphate compound is contained in an amount of 5 to 15 parts by weight based on 100 parts by weight of the total solid content of diisocyanates and diols. Thermoplastic polyurethanes having excellent self-extinguishing properties, including organic diisocyanates and long-chain diols and, optionally, a chain extender, an additive comprising a mixture of red and melamine cyanurate, and optionally a reaction in the presence of a catalyst. Manufacturing method. Polymerizing a composition comprising organic diisocyanates and long chain diols and, if necessary, a chain extender, in the presence of a catalyst, if necessary, to produce a polyurethane; And A method for producing a thermoplastic polyurethane having excellent self-extinguishing property, comprising the step of compounding an additive comprising a mixture of red and melamine cyanurate in a polyurethane.