KR100483112B1 - The Preparation of Flame Resisting Unsaturated Polyester Including Heat Expandable Graphite - Google Patents

Abstract

The present invention relates to a method for producing a flame-retardant unsaturated polyester using thermally expandable graphite, wherein 0.5 to 5 parts by weight of finely ground silica is added to 100 parts by weight of unsaturated polyester, rolling together to impart thixotropy, and then thermally expandable graphite. 3 to 40 parts by weight; The flame retardant is prepared by mixing and dispersing at least one flame retardant selected from the group consisting of 1 to 50 parts by weight of a halogen flame retardant, 0.5 to 50 parts by weight of a phosphorus flame retardant, and 10 to 300 parts by weight of an inorganic flame retardant.

The flame-retardant unsaturated polyester produced by the above method has the effect of improving the flame retardancy, reducing the amount of gas generated during combustion, and reducing the amount of addition when mixing the flame retardant.

Description

The Preparation of Flame Resisting Unsaturated Polyester Including Heat Expandable Graphite

The present invention relates to a method for producing a flame-retardant unsaturated polyester using thermally expandable graphite, wherein 0.5 to 5 parts by weight of finely ground silica is added to 100 parts by weight of unsaturated polyester, rolling together to impart thixotropy, and then thermally expandable graphite. 3 to 40 parts by weight; It is characterized in that it is prepared by mixing and dispersing at least one flame retardant selected from the group consisting of 1 to 50 parts by weight of halogen-based flame retardant, 0.5 to 50 parts by weight of phosphorus-based flame retardant and 10 to 300 parts by weight of inorganic flame retardant.

Generally, unsaturated polyester resins are prepared by condensation polymerization of polybasic basic acids and polyhydric alcohols, dissolving them in reactive monomers such as styrene, and adding and injecting curing agents to cure by crosslinking reaction.

The unsaturated polyester resin, which is a thermosetting resin, is easy to handle, has a low viscosity, and can freely adjust sclerosis without generation of volatiles at room temperature or high temperature. Such resins generally exhibit good mechanical properties, electrical properties, water resistance, broad resistance to chemicals, and excellent surface conditions. Also, due to their low cost, such resins include not only ships, automobiles, aircraft, trains, but also bathtubs, septic tanks, building interior and exterior agents, etc. It is used to manufacture various FRP molded products.

However, plastic molded articles including such unsaturated polyesters are generally burned easily and cause damage by generating a lot of toxic gases upon combustion. Therefore, many studies have been conducted in the past to improve the flame retardancy of the plastic and to reduce the amount of toxic gas generated.

 As the specific method, a compound containing a halogen element such as bromine and chlorine is used as a raw material or additive, a method of adding an inorganic flame retardant, a method of adding a phosphorus or a nitrogen flame retardant, or the like. In recent years, the above flame retardants are rarely used alone, and research has been conducted to improve the flame retardant performance and the amount of additives by interaction by using a combination of additional flame retardants while using the flame retardant at an appropriate ratio. .

Dorfman et al. Also discloses a process in which US Pat. No. 4,152,368 uses iron, copper, antimony or compounds thereof in unsaturated polyesters containing halogen elements. It shows excellent flame retardant effect by using halogen element as main flame retardant, and excellent in flame retardancy by using metal compound as synergist, but it is easy to cause corrosion of equipment due to gas toxicity due to increase of harmful combustion gas The effect of reducing halogen usage is minimal. In addition, the use of halogen compounds causes deterioration of weather resistance and adverse effects in terms of environmental friendliness.

In addition, Horold et al., In the US Patent No. 6,156,825, by using a combination of inorganic flame retardant aluminum hydroxide (ATH) and at least one nitrogen compound and an enemy in the unsaturated polyester resin, the amount of inorganic flame retardant is reduced, the amount of the resin composition Disclosed is a method for producing a non-halogen flame-retardant resin which improves disadvantages such as viscosity increase and physical property degradation such as molded product mechanical strength. However, in the above case, hydrogen cyanide (HCN) is generated during the combustion of nitrogen compounds, which limits the toxicity of the combustion gas, and the enemy used is a relatively expensive flame retardant and concerns about storage stability and safety during operation. have.

In order to solve the above problems, the present inventors studied a method for preparing a flame retardant unsaturated polyester, and mixed finely divided silica with an unsaturated polyester prepared by reacting a polyhydric alcohol and a polybasic acid. When prepared by mixing and dispersing the flame retardant, it can be used in combination with pulverized silica to reduce the settling rate, and confirmed that the flame retardancy of the unsaturated polyester is improved and completed the present invention.

Accordingly, it is an object of the present invention to provide a flame retardant unsaturated polyester in which the flame retardancy is improved and the amount of gas generated during combustion is reduced.

In order to achieve the above object, the unsaturated polyester according to the present invention is prepared by mixing finely divided silica with unsaturated polyester prepared by reacting polyhydric alcohol and polybasic acid, and mixing and dispersing graphite and flame retardant thereto. .

More specifically, the manufacturing method of the unsaturated polyester is added to 0.5 to 5 parts by weight of finely ground silica with respect to 100 parts by weight of unsaturated polyester and rolling together to give a thixotropy, 3 to 40 parts by weight of thermally expandable graphite; The flame retardant is prepared by mixing and dispersing at least one flame retardant selected from the group consisting of 1 to 50 parts by weight of a halogen flame retardant, 0.5 to 50 parts by weight of a phosphorus flame retardant, and 10 to 300 parts by weight of an inorganic flame retardant. In addition, the produced liquid resin can produce a desired molded article by various molding methods.

The heat-expandable graphite used in the present invention expands to the surface when heat is applied to the plastic molded article and adheres in a form similar to combustion carbide (char), thereby protecting the molded article and thus exhibiting excellent heat shielding effect and expanding the inside of the molded article by expansion. It slows down heat transfer and can significantly improve the flame retardancy of plastics in relatively small amounts. In addition, when the thermally expandable graphite is used in combination with other flame retardants, the amount of the thermally expandable graphite can be significantly reduced, thereby reducing problems of resin properties and workability. In particular, since surface combustion is suppressed, an excellent effect can be obtained in terms of reducing the amount of combustion gas generated.

On the other hand, the usage-amount of graphite is 3-40 weight part with respect to 100 weight part of unsaturated polyesters, Preferably it is 5-20 weight part. In addition, the thermally expandable graphite used in the present invention contains a carbon component of 90 to 99% and a sulfuric acid or nitric acid component with a particle size of 32 to 325 mesh, and the pH is in the range of 3 to 7. The thermally expandable graphite begins to expand at 100-200 ° C. and its expanded volume is 10-400 ml / g.

Halogen-based flame retardants that can be used in the production method of the present invention include chlorine-based flame retardants and bromine-based flame retardants. More specifically, examples of the chlorine-based flame retardant include tetrachlorophthalic anhydride and chlorostyrene, and bromine-based flame retardants include tetrabromophthalic acid, tetrabromobisphenol A, decabromodiphenyl oxide, octabromodiphenyl oxide, and bistribromo. Phenoxy ethane, hexabromocyclododocin, bromine modified epoxy oligomers, and the like.

In addition, as the phosphorus-based flame retardant of the present invention, triphenyl phosphate (TPP), trixylenyl phosphate (TXP), tributyl phosphate (TBP), tricresyl phosphate (TCP), cresyl diphenyl phosphate (CDPP), etc. Halogen-containing organophosphates, such as phosphate esters, tridichloropropyl phosphate (TDCP), trichloroethyl phosphate (TCEP), trichloropropyl phosphate (TCPP) and triisophenyl phosphate, polychlorophosphonates, and polyammonium phosphates Polyphosphoric acids such as (APP), polyinorganic phosphoric acids, and the like.

Further, the inorganic flame retardant of the present invention includes aluminum hydroxide, magnesium hydroxide, antimony trioxide, antimony pentoxide, molybdenum trioxide, guanidine sulfamate, guanidine phosphate, guanidine phosphate, zinc stannate, zinc oxide, silicate, melamine and pentaerithritol.

On the other hand, in the production method, one or more selected from the above halogen-based flame retardant, phosphorus-based flame retardant, inorganic flame retardant is mixed and used, in addition to the flame retardant additives, accelerators, defoamers, thixotropic agents, retardants, ultraviolet absorbers, antifoaming agents, mold release agents, water Other additives such as a festival can be used, and the unsaturated polyester resin can be modified by other raw materials such as epoxy, acrylic, isocyanate, dicyclopentadiene and the like.

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited only to these examples.

Example 1

1.2 parts by weight of finely divided silica, 25 parts by weight of tetrabromobisphenol A (TBBPA) oligomer which is a halogen flame retardant, and 10 parts by weight of thermally expandable graphite are added to 100 parts by weight of vinyl bromide ester resin (DION-9300, manufactured by Aekyung Chemical Co., Ltd.). Then, 1 part by weight of 8% cobalt octateate or dimethylaniline (DMA) as an accelerator and 1 part by weight of methyl ethyl ketone peroxide (MEKPO) were mixed with a curing agent, impregnated with glass fibers, and cured at room temperature, thereby preparing a molded product.

Example 2

80 parts by weight of ortho-unsaturated polyester resin (OS-980, manufactured by Aekyung Chemical Co., Ltd.), 20 parts by weight of ortho-unsaturated polyester (NA-104, manufactured by Aekyung Chemical Co., Ltd.) 0.7 parts by weight of silica, 5 parts by weight of thermally expandable graphite, 40 parts by weight of low shrinkage agent, 200 parts by weight of aluminum hydroxide (BW-153, made of Nippon Light Metal), an inorganic flame retardant, 50 parts by weight of calcium carbonate (made by OMYA 2, OMYA) with filler After mixing 2 parts by weight of tertiary butyl perbenzoate as a catalyst and 50 parts by weight of glass fiber, the product was cured at 120 to 150 ° C to prepare a molded article.

Example 3

80 parts by weight of the same ortho-unsaturated polyester resin as in Example 2 20 parts by weight of ortho-unsaturated polyester containing a halogen in the molecular chain, 0.5 parts by weight of finely divided silica, 5 parts by weight of thermally expandable graphite, low shrinkage agent 40 parts by weight, 150 parts by weight of aluminum hydroxide, an inorganic flame retardant, 50 parts by weight of calcium carbonate, 2 parts by weight of tertiary butyl perbenzoate and 50 parts by weight of glass fiber were mixed and cured at 120 to 150 ° C. to prepare a molded article. .

Example 4

10 parts by weight of thermally expandable graphite, 1.0 part by weight of pulverized silica, 40 parts by weight of low shrinkage agent, 150 parts by weight of aluminum hydroxide, 50 parts by weight of calcium carbonate, tertiary butyl perbenzoate 2 parts by weight and 50 parts by weight of glass fibers were mixed and cured at 120 to 150 ° C. to produce a molded article.

Comparative Example 1

100 parts by weight of a vinyl bromide ester resin (DION-9300, manufactured by Aekyung Chemical Co., Ltd.) was mixed with 1 part by weight of an accelerator and 1 part by weight of methyl ethyl peroxide, and then impregnated with glass fiber to cure at room temperature to produce a molded article.

Comparative Example 2

20 parts by weight of ortho-unsaturated polyester resin containing halogen in the molecular chain of 80 parts by weight of the ortho-unsaturated polyester resin, 2 parts by weight of thermally expandable graphite, 40 parts by weight of low shrinkage agent, 150 parts by weight of aluminum hydroxide, 50 parts by weight of calcium carbonate 2 parts by weight of butyl benzoate and 50 parts by weight of glass fiber were mixed and cured at 120 to 150 ° C. to produce a molded article.

Comparative Example 3

20 parts by weight of ortho-unsaturated polyester resin containing halogen in the molecular chain of 80 parts by weight of the ortho-unsaturated polyester resin, 50 parts by weight of thermally expandable graphite, 40 parts by weight of low shrinkage agent, 150 parts by weight of aluminum hydroxide, 50 parts by weight of calcium carbonate 2 parts by weight of butyl benzoate and 50 parts by weight of glass fiber were mixed and cured at 120 to 150 ° C. to produce a molded article.

Test Example

The results of the combustion test and the mechanical property test of the molded products prepared in Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 1 and Table 2.

[Test Example 1]

LPG GAS as a fire source was 5 cm in size and the method of direct heating the molded article made in Examples 1 to 4 and Comparative Examples 1 to 3 with a 45 ° angle, the heating time was compared with Example 1 and Example 1 was 2 minutes, and the other examples were made into 10 minutes. Thereafter, the combustion length and the combustion area were measured using a planetarometer, and the self-extinguishing time was visually measured. The results are shown in Table 1.

[Test Example 2]

The coefficients of smoke and residual flame time are based on KS M 2271 standard, and the molded products manufactured in Examples 1 to 4 and Comparative Examples 1 to 3 are, in principle, a heat source having a constant voltage device as a heat source for 3 minutes. In principle, it was heated for 3 minutes with an auxiliary heat source using LP gas as a heat source. Thereafter, the amount of light passing through the smoke was measured every 15 seconds, and the smoke emission coefficient was determined by Equation 1 below. In addition, the residual flame time was measured visually and the results are shown in Table 1.

I _o : Light intensity at the start of the heating test (lx)

I: minimum value of light intensity during heating test

[Test Example 3]

Oxygen index is based on KS M 3032 standard, the molded article prepared in Examples 1 to 4 and Comparative Examples 1 to 3 is heated using a mixed gas of oxygen and nitrogen as a heat source, and after selecting the initial oxygen concentration arbitrarily, burning the test piece If the time exceeds 3 minutes or if the combustion length exceeds 5 cm, repeat the experiment with a lower oxygen concentration to determine the value of the lowest oxygen concentration that represents the volume percentage of oxygen required for the material to sustain combustion. Oxygen index was determined by the following equation (2). The results are shown in Table 1.

[O ₂ ]: flow rate of oxygen, [N ₂ ]: flow rate of nitrogen

Flame resistance test result Example Comparative example One 2 3 4 One 2 3  Combustion length (mm) 127 162 176 170 174 215 175 Combustion area (mm ² ) 1244 2190 2305 2220 2267 3319 2270  Self-extinguishing time (sec) 0 0 0 0 2 0 0 Coefficient of Smoke (C _A ) - 50.3 56.7 44.8 - 131.1 129.4  Residual Flame Time (sec) - 48 53 45 - 112 110  Oxygen index - - - 48 or more - 35 35

As can be seen in Table 1, it was confirmed that the use of thermally expandable graphite improves the flame retardant performance by reducing the combustion length, the combustion area, the self-extinguishing time, the combustion coefficient and the residual flame time, and the oxygen index. In particular, in Example 2 and Example 4, it was found that the coefficient of smoke reduction was significantly reduced by using thermally expandable graphite as compared with the comparative example containing halogen group.

[Test Example 4]

Flexural strength and flexural modulus were measured by ASTM D 790 to specify the mechanical properties of Examples 1 to 4 and Comparative Examples 1 to 3. In addition, the tensile strength and tensile modulus was measured by ASTM D 638 and the results are shown in Table 2.

Mechanical property test results of laminate Example Comparative example One 2 3 4 One 2 3  Flexural Strength (Kgf / ㎡) 19.5 11.7 12.0 12.5 18.2 11.5 11.4  Flexural modulus (Kgf / ㎡) 700.5 131500 132500 133000 643.7 131000 130000  Tensile Strength (Kgf / ㎡) 12.7 5.3 5.8 5.5 11.6 5.5 5.3  Tensile Modulus (Kgf / ㎡) 750.3 - - - 714.1 - -

As can be seen in Table 2, even when thermally expandable graphite is added, it was confirmed that the mechanical properties are excellent without adversely affecting.

As described above, after the thermally expandable graphite is added to the unsaturated polyester liquid resin according to the present invention together with the pulverized silica, the molded article produced by the same is carbonized on the surface due to expansion of the thermally expandable graphite when exposed to heat. Excellent flame retardant performance is achieved by forming a char layer and forming a space inside a molded article.

Claims (5)

delete After adding 0.5 to 5 parts by weight of finely ground silica to 100 parts by weight of unsaturated polyester prepared by reacting polyhydric alcohol and polyvalent basic acid, rolling together to further expand thixotropy, 3 to 40 parts by weight of thermally expandable graphite; And 1 to 50 parts by weight of halogen-based flame retardant, 0.5 to 50 parts by weight of phosphorus-based flame retardant and 10 to 300 parts by weight of inorganic flame retardant is prepared by mixing and dispersing at least one flame retardant selected from the group consisting of. . The flame-retardant unsaturated according to claim 2, wherein the thermally expandable graphite contains 90 to 99% of carbon and sulfuric acid or nitric acid in a particle size of 32 to 325 mesh, and its pH is in the range of 3 to 7. Method for producing polyester. The method of claim 2, wherein the thermally expandable graphite begins to expand at 100 to 200 ° C, and has an expansion volume of 10 to 400 ml / g. The method of claim 2, wherein the unsaturated polyester is an unsaturated polyester resin modified by other raw materials such as epoxy, acryl, isocyanate, dicyclopentadiene in addition to the unsaturated polyester. Method for producing a flame retardant unsaturated polyester, characterized in that.