JP2001220462A - Method for producing composite composition for imparting flame retardance, composite composition for imparting flame retardance and flame-retardant high-molecular composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically obtain an ecological composite composition for imparting flame retardance, capable of imparting high flame reatardance without generating toxic substances in its production or incineration, to provide a method f or producing the composition, and to economically obtain a flame-retardant high-molecular composite material by compositing the composite composition for imparting flame retardance. SOLUTION: This composite composition for imparting flame retardance is obtained by compositing a gel composition with carrier material particles of aluminum hydroxide wherein the gel composition is obtained by mixing a sol composition dispersing and/or dissolving zinc nitrate (containing crystal water) and an Si-alkoxide in a solvent and drying the mixed sol composition. The composite particles for imparting flame retardance contains a silicon component, a zinc component and oxygen and has such a construction as to composite the carrier material particles with the gel composition producing vitreous ceramics by heating. The flame-retardant high-molecular composite material is obtained by compositing through mixing the composite composition for imparting flame retardance with a polyolefin-based polymeric material or through coating the composite composition on the polymeric material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant composite composition for imparting flame retardancy to a material composed of a resin or the like, a method for producing the same, and a flame-retardant composite composition. The present invention relates to a flame-retardant polymer composite material obtained by compounding a polymer material.

[0002]

2. Description of the Related Art Resin materials are used in a wide range of fields because of their excellent chemical and physical properties, excellent moldability and workability, and their demand is growing. The major disadvantage of the resin material is that it is easy to burn, so its use is restricted, and it is desired to make the resin material flame-retardant.

[0003] Halogen-based flame retardants are mainly used as flame retardants for making resin materials flame-retardant. However, they are not preferable in terms of environmental protection due to the problem of dioxins and furans generated from halogen-based flame retardants. The development and commercialization of fuel agents are desired. Non-halogen phosphorus-based flame retardants are not preferred because phosphine, which is a hydride of phosphorus, is generated.

[0004] In addition, there are inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide. Aluminum hydroxide has low harmfulness, low smoke emission, good electric insulation, and low cost, so that among the flame retardants, There is a lot of demand. However, as a problem, mechanical properties, decrease in water resistance, and a large amount (particularly, U
When tested by the L94 flammability test, 150 parts by weight or more is required to achieve flame retardancy satisfying V-0, and 80 to 100 parts by weight is required even when a flame retardant aid is added. To increase the viscosity of the compound, to deteriorate the moldability and physical properties of the resin, to have a low flame-retardant effect at a high temperature of 400 ° C. or higher, or to easily cause dehydration and foaming during processing of a resin having a high molding temperature.

Magnesium hydroxide has the same flame-retardant effect as aluminum hydroxide, and does not have dewatering and foaming at the processing temperature of resin, which is a disadvantage of aluminum hydroxide. However, they have disadvantages such as reaction with carbon dioxide in the air to produce magnesium carbonate and whitening, and cost is higher than aluminum hydroxide. In addition, since these inorganic flame retardants alone have a small flame retardant effect, they also need to be used in combination with other flame retardants or a flame retardant auxiliary.
In this case, if red phosphorus or carbon is added as a flame retardant, the resin is colored reddish purple or black, so that the purpose of use is limited. Further, when multi-components are added, the dispersibility is not good when mixing these additives and the resin, so that the mixing takes a long time and causes an increase in production cost. In addition, there is a glass-based flame retardant using low-melting glass, but the manufacturing process is complicated and requires a large amount of addition to the resin,
The production cost is high, and there is also a problem with water resistance.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a high flame retardancy (UL) at a low addition rate.
An ecological composite composition for imparting flame retardancy, which is capable of providing flame retardancy satisfying V-0 when tested in a 94 flammability test, and does not generate harmful substances during production or combustion. And a method for producing the same, and a flame-retardant polymer composite material obtained by compounding a flame-retardant composite composition. Another object of the present invention is to eliminate the discoloration of the resin and to expand the purpose of use of the flame-retardant resin by using the flame-retardant composite composition.

[0007]

Means for Solving the Problems and Action / Effect To solve the above problems, a method for producing a flame-retardant composite composition according to the present invention comprises zinc nitrate (including water of crystallization) and alkoxide of Si. Mixing a sol composition dispersed and / or dissolved in a solvent with aluminum hydroxide (which is a supporting material) generally used as a flame retardant; and mixing the sol composition with the supporting material. At least a step of drying the mixture, wherein the gel composition produced by drying the sol composition is combined with the carrier material to obtain a flame-retardant composite composition. The sol composition may be formed from a solution in which zinc nitrate (including water of crystallization) and alkoxide of Si are dispersed and / or dissolved in a solvent.

As described above, a composite composition for imparting flame retardancy can be obtained by a so-called sol-gel method in which the sol composition is dried and the gel composition is composited with the carrier material. The sol-gel method as described above is simple and does not require special equipment, so that the production cost can be significantly reduced and no harmful substances are generated during the production as in the past. . The composite material for imparting flame retardancy obtained by such a production method has a gel-like Zn
And a compound of Si. When this is mixed (added) with a material such as a resin or the like by coating or the like, for example, when high heat is applied to the material to be provided with flame retardancy, the high heat causes the material to be used for imparting flame retardancy. The above-mentioned inorganic compound in the composite composition is vitrified or ceramicized, and the vitrified or ceramicized inorganic compound becomes a protective film, and can impart high flame retardancy to the material to be imparted with flame retardancy. Becomes Further, a material obtained by compounding such a composite material for imparting flame retardancy does not generate a harmful gas as in the past when a high heat is applied, and thus becomes an ecological flame retardant material. Note that in the above manufacturing method, the step of bringing the sol-like composition into contact with the support material may employ a method of dipping the support material in the sol-form composition, a method of spraying the sol-form composition on the support material, or the like. Can be.

The above-described aluminum hydroxide is used as a carrier material particle, and the gel composition is compounded on the entire surface or a part of the surface thereof to obtain a flame-retardant composite particle as a flame-retardant composite compound. be able to. In this case, according to the sol-gel method, it is possible to obtain composite particles for imparting flame retardancy in which the gel composition containing the inorganic compound is uniformly dispersed and composited with the carrier material particles. When the particles are coated with the flame retardant composite particles in which the surface of the particles is covered with a film of the gel composition, the film of the gel composition is thin and uniform, for example, about 0.01 to 1.0 μm. Becomes When such composite particles for imparting flame retardancy are combined (added) to a material to be imparted with flame retardancy, the carrier material particles are coated with the gel composition in a uniform and thin film form. The effect of imparting flame retardancy is large, and the amount of the composite particles for imparting flame retardancy is sufficient, for example, in a small amount of 50 to 100 parts by weight, preferably about 60 to 80 parts by weight, per 100 parts by weight of the material to be imparted with flame retardancy. It is possible to provide excellent flame retardancy. In this case, since a small amount is added, there is little change in the physical properties of the material to which the flame retardancy is to be added, such as a resin to be added, and it is also possible to improve the moldability and greatly reduce the cost.

[0010] The production method using the sol-gel method specifically includes a mixing step of forming a mixture of carrier material particles and a sol-like composition, and a drying step of evaporating the solvent from the mixture to form a dry composition. And may include:
This is, for example, to put a sol-like composition in a predetermined container, immerse the carrier material particles into a mixture to form a mixture, and then evaporate the solvent from the mixture, and remove the solvent without draining the mixture. This is a very simple method because it can be evaporated and dried. In addition, since the composite particles for imparting flame retardancy are finely pulverized by pulverization or pulverization of the above-mentioned dry composition, it is easy to handle when mixing (adding) into the material to be imparted with flame retardancy or coating. Thus, the composite particles for imparting flame retardancy can be easily and uniformly dispersed and composited with the material to be imparted with flame retardancy. The drying step can be performed by heating drying or vacuum drying, or a combination thereof.

The drying step can be carried out, for example, by applying vibration and / or stirring to the aggregate of the particles of the supporting material while bringing the sol-like composition into contact therewith.
In this case, drying efficiency is improved by vibration and / or stirring of the integrated body, and the drying time can be shortened. On the other hand, it is also possible to mix a striking medium having a larger diameter with the carrier material particles and apply vibration and / or agitation to an aggregate of the carrier material particles and the striking medium,
In this case, the drying time can be further reduced.

Next, the sol composition is preferably produced by hydrolyzing zinc nitrate (including water of crystallization) and alkoxide of Si. The hydrolysis may promote the reaction by adding an appropriate amount of water, but rather without adding water,
By utilizing the water derived from the water of crystallization contained in zinc nitrate (including water of crystallization), the powder of the gel composition obtained after drying the sol composition becomes a sticky, free-flowing powder, which is then handled. Performance is very good. The gel composition produced by hydrolyzing such an alkoxide contains Zn and Si, and organic substances derived from the alkoxide remain. As described above, Zn and Si are vitrified or ceramicized by high heat to impart high flame retardancy to the material to which flame retardancy is to be imparted, and gases derived from zinc nitrate, such as N ₂ gas, NO ₂ gas, NO Gases and the like are generated, which further improve the flame-retardant effect on the flame-retardant material.
In addition, for example, when a resin is used as the material to be imparted with flame retardancy, the composite particles for imparting flame retardancy are uniformly dispersed in the composite composition for imparting flame retardancy to the material to be flame retarded. In addition to being able to be dispersed, it is also possible to improve the moldability and the like of the material to be imparted with flame retardancy.

An alcohol can be used as a solvent for preparing the sol composition. Since alcohol has a relatively low melting point, it has an advantage that the drying step can be performed in a short time. As such an alcohol, for example, methanol, ethanol, propanol and the like can be used. Of these alcohols, ethanol is the most preferable because it is inexpensive and simple and is stable to Si alkoxide.

The above-mentioned Si alkoxide is an oxide formed
Consideration of stability of sol composition, stability and cost
And most excellent as an alkoxide component. Note that S
Examples of the alkoxide using i include tetraethoxy
Sisilane (Si (OC_TwoH_Five) _Four) Etc. can be used
You. The components of the alkoxide vary according to the purpose.
In this case, the gel-like composition formed
The properties of the object coating are different from each other.

On the other hand, the above sol-like composition is preferably mixed with zinc nitrate (including crystallization water). When zinc nitrate (including water of crystallization) is contained in the sol-like composition, a gas derived from nitrate is generated when high heat is applied to the flame-retardant material to which the flame-retardant composite material is added. , For example N ₂
Gas, NO ₂ gas, NO gas, and the like are generated, which further improve the flame retardant effect on the material to which the flame retardancy is to be imparted. In addition, as a specific example of the above-mentioned zinc nitrate (including crystallization water),
Zinc nitrate hexahydrate (Zn (NO ₃ ) ₂ .6H ₂ O) and the like can be exemplified. Further, the water of crystallization contained in the zinc nitrate (including the water of crystallization) is effectively used for the hydrolysis of the sol composition, so that it is not necessary to particularly add water for the hydrolysis of the sol composition. This reduces the number of hydrogenation steps and eliminates the need for a required distilled water production apparatus, which can contribute to a reduction in production cost.

In the production method of the present invention, for example, a step of preparing a first solution by dispersing and / or dissolving the metal salt in an alcohol, and dispersing and / or dissolving an alkoxide in the first solution to form a second solution. A step of forming a solution and a neat sol composition. in this way,
By performing each step of sequentially dispersing and / or dissolving the metal salt and the alkoxide in the alcohol in a stepwise manner, the sol composition can be efficiently produced. In addition, it is also possible to disperse and / or dissolve the alkoxide in a solvent such as an alcohol, and to add a metal salt and a solvent such as an alcohol thereto. The order of the steps can be arbitrarily changed.

Next, the sol composition is dried at 120 to 2
It is better to carry out in the range of 00 ° C. When the temperature is lower than 120 ° C., it takes a long time to dry the sol-like composition, and when it is compounded in a polymer material substrate, the polymer composite material may be colored. If the temperature exceeds 200 ° C., the sol composition or aluminum hydroxide may be decomposed. Preferably, the temperature is 130 to 150 ° C., and the gel composition after drying has no stickiness, and becomes fine powder when pulverized, and the handling performance thereafter is very good. When drying under reduced pressure, it is necessary to adjust the temperature and pressure so that the sol composition stably remains (adheres) to the support material.

As the support material particles, for example, aluminum hydroxide generally used as a flame retardant can be used. In this case, in addition to the effect of imparting flame retardancy based on the Si alkoxide and zinc nitrate (including water of crystallization), the flame retardant effect of the flame retardant material particles as the support material is added. It becomes more effective to impart flame retardancy to the material to which the object is imparted flame retardancy.

The flame-retardant material particles have, for example, an average particle size of 1 to 1.
It is preferable to use one having a thickness of 20 μm. If the average particle size is less than the lower limit, the production may be difficult,
When the composite (addition) is added to the material to which the flame retardancy is to be added, uneven distribution occurs, and the composite (addition) may not be uniform. In particular, there is a case where it is lowered in the uneven distribution region. If the upper limit is exceeded, the distribution of the composite (added) particles may be non-uniform, and the properties of the material to be imparted with flame retardancy, for example, properties such as fluidity may be reduced or the flame retardancy may not be imparted. The target material may cause poor appearance.
The average particle size can be measured by using, for example, a laser diffraction particle size analyzer. In this case, the measurement by the laser diffraction type particle sizer does not cause a large difference between the diffraction behavior of the incident laser light by the aggregated particles and the diffraction behavior by the isolated primary particles. It cannot be distinguished from the particle size of the existing particles or the particle size of the aggregated secondary particles. Therefore, the average particle size measured by this method is a value reflecting the average particle size of the secondary particles, which also includes isolated primary particles that do not agglomerate in a broad sense.

On the other hand, the composite particles for imparting flame retardancy as the composite composition for imparting flame retardancy are dispersed in a matrix composed of a polymer material as a material to be imparted with flame retardancy, or fixed on the surface of the substrate. can do. Thus, the flame-retardant polymer composite material obtained by compounding the flame-retardant composite particles exhibits high flame retardancy due to the flame-retardant effect given by the above-mentioned alkoxide, metal salt, flame-retardant material particles and the like. .

It is most preferable to use, for example, a polyolefin resin such as polypropylene (PP) or polyethylene (PE) as the polymer material.

The content ratio of the composite composition (particles) for imparting flame retardancy in the polymer substrate is preferably 50 to 100 parts by weight based on 100 parts by weight of the polymer substrate. When the content ratio is less than 50 parts by weight, the main factor of the flame retardancy imparting effect,
The effect of imparting flame retardancy due to vitrification or ceramicization of metal and / or Si of the alkoxide is reduced, and UL94
When tested in a flammability test, it may not be possible to achieve the flame retardancy that satisfies V-0, and if it exceeds 100 parts by weight, it becomes an unnecessary amount for imparting flame retardancy and costs And the properties of the polymer substrate may be significantly changed. The content ratio is preferably set to 60 to 80 parts by weight.

The composite composition for imparting flame retardancy in the polymer substrate is composed of 30 to 70 parts by weight of aluminum hydroxide of the carrier material particles per 100 parts by weight of the polymer substrate, The mixing ratio is preferably 3 to 18 parts by weight of Si alkoxide and 20 to 45 parts by weight of zinc nitrate.

The sol composition to be composited with the flame-retardant composite composition is mainly composed of Si and Zn components, and the components are SiO. ₂ to 1 to 5 parts by weight, ZnO to 6 to 12
It may be by weight.

[0025]

Example 1 65.80 g of zinc nitrate hexahydrate (Zn (NO ₃ ) ₂ .6H ₂ O) as a metal salt was placed in 60 ml of ethanol and dissolved by heating. 20.80 g of ethyl silicate (Si (OC ₂ H ₅ ) ₄ ) was added to the solution, and the solution was stirred to produce a sol-like composition. In this sol-like composition, the average particle diameter is 1 μm as carrier material particles.
Was added and mixed with stirring. Thereafter, the mixture was placed in a dryer at 140 ° C., and the solvent was evaporated to form a coating film of the gel composition (glass precursor composition) on the aluminum hydroxide surface. In addition, in order to estimate the components of the coating film, when analyzing the gel composition obtained by drying only the sol composition,
It turned out that it was a compound containing each element of Si, Zn, O, N, and C.

The powder of aluminum hydroxide coated with the above sol-gel method and polypropylene (made by Grand Polymer: J708) is mixed (polypropylene 100).
Parts, coated 73 parts of coated aluminum hydroxide (50 parts if aluminum hydroxide before coating)
Part)) After the pellets were prepared, the pellets were placed in an injection molding machine and injection molded at 180 ° C. into a sample shape for a flame retardancy test. Sample shape for flame retardancy test is UL94
Based on the flammability test, the length was 125 mm, the width was 13 mm, and the thickness was 1.6 mm. The color of the molded sample was a color close to white.

As a result of a UL94 flammability test using the prepared sample for flame retardancy test, the fireball formed at the tip of the combustion did not fall.
Cleared the 0 standard.

Further, a combustion test by the oxygen index method (JIS
K7201), length 120mm, width 6.5m
A sample having a thickness of 3 mm and a thickness of 3 mm was prepared and tested in the same combustion test. As a result, an oxygen index of 40% was obtained.

Comparative Example 1 As a metal salt, 65.80 g of zinc nitrate hexahydrate (Zn (NO ₃ ) ₂ .6H ₂ O) was placed in 60 ml of ethanol and dissolved by heating. 20.80 g of ethyl silicate (Si (OC ₂ H ₅ ) ₄ ) was added to the solution,
Next, the liquid was stirred to produce a sol-like composition.
In this sol-like composition, the average particle diameter is 1 μm as the carrier material particles.
m of aluminum hydroxide was added and mixed with stirring. Thereafter, the mixture was placed in a dryer at 110 ° C., and the solvent was evaporated to form a coating film of the gel composition (glass precursor composition) on the aluminum hydroxide surface.

The aluminum hydroxide coated by the sol-gel method and a powder of polypropylene (made by Grand Polymer: J708) are mixed (polypropylene 100).
Parts, coated 73 parts of coated aluminum hydroxide (the amount of aluminum hydroxide before coating was 50 parts
Part)) After the pellets were prepared, the pellets were placed in an injection molding machine and injection molded at 180 ° C. into a sample shape for a flame retardancy test. The sample shape for the flame retardancy test was obtained in Example 1.
And a UL94 flammability test was conducted. Also,
A sample for measuring an oxygen index similar to that in Example 1 was prepared, and a combustion test was also performed by an oxygen index method. The color of the molded sample was brown.

As a result of the test in the UL94 flammability test,
The number of fireballs formed at the tip of the combustion is one,
The evaluation of this test was V-2. As a result of a combustion test by the oxygen index method, an oxygen index of 40% was obtained.

Comparative Example 2 As a metal salt, 65.80 g of zinc nitrate hexahydrate (Zn (NO ₃ ) ₂ .6H ₂ O) was placed in 250 ml of ethanol and dissolved by heating. 20.80 g of ethyl silicate (Si (OC ₂ H ₅ ) ₄ ) was added to the solution, and the solution was stirred to produce a sol-like composition. 375 g of aluminum hydroxide having an average particle size of 1 μm was added as the support material particles to the sol composition and mixed with stirring. Thereafter, the mixture was placed in a dryer at 140 ° C., and the solvent was evaporated to form a coating film of the gel composition (glass precursor composition) on the aluminum hydroxide surface. In order to estimate the components of the coating film,
When the gel composition obtained by drying only the sol composition was analyzed, it was found to be a compound containing each element of Si, Zn, O, N, and C.

The aluminum hydroxide coated with the sol-gel method and a powder of polypropylene (G708 made by Grand Polymer) are mixed (polypropylene 100).
Parts, coated aluminum hydroxide 55.
After preparing 6 parts (50 parts in terms of the amount of aluminum hydroxide before coating) pellets, the pellets were placed in an injection molding machine and injection molded at 180 ° C. into a sample shape for a flame retardancy test. Sample shape for flame retardancy test is UL
Based on 94 flammability test, length 125mm, width 13m
m and 1.6 mm in thickness. The color of the molded sample was a color close to white.

Using the sample for flame retardancy test prepared above, a UL94 flammability test was conducted. As a result, the number of fireballs formed at the tip of the combustion was 5, but the evaluation in this test was V- It was 2.

Further, a combustion test by the oxygen index method (JIS)
K7201), length 120mm, width 6.5m
A sample having a thickness of 3 mm and a thickness of 3 mm was prepared and tested by the same combustion test to obtain an oxygen index of 31%.

Table 1 summarizes the results of Example 1 and Comparative Examples 1 and 2.

[0037]

[Table 1]

From these results, it can be seen that the polypropylene coated with aluminum hydroxide coated by the sol-gel method has high flame retardancy (UL9
(V-0 is cleared in the 4 flammability test). The drying temperature of aluminum hydroxide coated by the sol-gel method changes to brown at 110 ° C., whereas when it is set to 120 ° C. or higher (140 ° C. in the present embodiment) as in the present invention, the discoloration does not change. The color was very slight and almost white. This means that coloring, which is a drawback of conventional flame retardants, can be prevented, and by using the flame retardancy-imparting composite composition of the present invention, there is no restriction on the use of addition to resins, and it can be used especially for colored resins. is there.

Claims (7)

[Claims] 1. a step of mixing a sol-like composition in which zinc nitrate (including water of crystallization) and an alkoxide of Si are dispersed and / or dissolved in a solvent with a carrier material composed of aluminum hydroxide; At least a step of drying a mixture of a material and a support material, and a flame-retardant composite composition obtained by combining the support material with a gel composition produced by drying the sol composition. A flame retardancy that is dispersed in a substrate made of a material (hereinafter, also referred to as a polymer substrate) and satisfies V-0 when tested in a UL94 flammability test. Composite composition. 2. The flame retardancy-imparting composition according to claim 1, wherein the content ratio of the composite material for imparting flame retardancy in the polymer matrix is 50 to 100 parts by weight based on 100 parts by weight of the polymer matrix. Composite composition. 3. The composite material for imparting flame retardancy in the polymer substrate, wherein the carrier material particles have 30 to 70 parts by weight of aluminum hydroxide per 100 parts by weight of the polymer substrate, The flame-retardant composite composition according to any one of claims 1 to 2, wherein the compound is prepared at a compounding ratio of 3 to 18 parts by weight of Si alkoxide and 20 to 45 parts by weight of zinc nitrate. 4. The gel composition to be composited with the flame-retardant composite composition is mainly composed of Si and Zn components, and the component is SiO 2 in terms of oxide based on 100 parts by weight of the polymer substrate. 4. The composite composition for imparting flame retardancy according to claim 1, wherein ₂ is 1 to 5 parts by weight and ZnO is 6 to 12 parts by weight. 5. The flame-retardant polymer composite material according to claim 1, wherein the polymer substrate is a polyolefin resin. 6. The gel composition is produced by hydrolyzing zinc nitrate (including crystallization water) and alkoxide of Si using water of crystallization contained in zinc nitrate without adding water. The composite composition for imparting flame retardancy according to claim 1. 7. The method for producing a flame-retardant composite composition according to claim 1, wherein the mixture of the sol composition and the support material is dried at a temperature of 120 to 200 ° C.