JPS63301246A - Flame retardant for polystyrene and flame-retarding polystyrene composition - Google Patents

Abstract

PURPOSE:To obtain flame retardant for PS not causing the deterioration of the properties of PS and having no fear of injuring equipment such as molds or molding machines, by mixing tris(2,3-dibromopropylene) isocyanurate with Sb2O3. CONSTITUTION:50-100pts.wt. Sb2O3 and, optionally, a colorant and a binder are added to 100pts.wt. tris(2,3-dibromopropylene) isocyanurate, and the mixture is pelletized to obtain a flame retardant for PS. Said flame retardant is added to PS so that the amount of the tris(2,3-dibromopropylene) isocyanurate may be 1% or above.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Application of the Invention) The present invention relates to a novel flame retardant for polystyrene and a polystyrene youth composition containing the same as a flame retardant.

(Conventional technology) Polystyrene resin (PS resin) is colorless and transparent.

It has excellent moldability (fluidity, dimensional stability, etc.), good electrical properties, and is inexpensive, so it is extremely widely used in various industrial and consumer molded products, films, foam molded products, etc. ing. However, since this resin has considerable flammability, it is desirable to impart as much flame retardancy as possible to increase safety against fire.

Therefore, attempts have already been made to make this resin flame retardant, including the use of halogen compounds (especially bromine-containing organic compounds) (
flame retardant main agent) and antimony trioxide (Sb20z) (
It is known that it is effective to add it together with a flame retardant additive). Here, as the bromine-containing organic compound, decabromodiphenyl ether (DBE), tetrabromobisphenol A (TBA) and derivatives thereof, hexabromocyclododecane (HBCD), and tribromostyrene oligomer (TBSO) are generally used. .

(Problems with the Prior Art) However, since these flame retardants are essentially foreign substances to the present resin, their addition deteriorates the mechanical properties of the present resin. Therefore, the amount of flame retardant added must be as small as possible, and it must not decompose below the processing temperature of the resin.

However, according to the inventor's experiments, many flame retardants meet the standards of the U.S. non-life insurance company's Underwriter'5Labo, which currently has one of the most trusted standards.
5 to 10 for this resin in order to meet the UL94V2 standard in the plastic flammability test standards established by Ratories.
It was necessary to add as much as %. However, hexabromocyclododecane (HBCD) was an exception and satisfied the above UL standard with the addition of about 1%, but this substance has a low decomposition temperature (the literature value indicates a decomposition point of 250°C or lower, and the inventor's According to actual measurements, it decomposes even at the working temperature of this resin. Hydrogen bromide gas generated by decomposition not only corrodes metals and processing machinery, but is also harmful to health.
Moreover, it causes bubbles (commonly called silver marks) in the molded workpiece. Therefore, the processing temperature of the present resin to which the present HBCD is added is necessarily limited to a relatively low temperature below its decomposition temperature, and naturally the processability of the resin is significantly reduced.

(Object of the Invention) Therefore, an object of the present invention is to provide an effective, stable, and economical flame retardant for polystyrene resin and a flame-retardant polystyrene composition that can replace existing flame retardants.

(Means for achieving the object) In order to achieve the above object, the gist of the present invention is to select tris(2,3-dibromopropylene) isocyanurate as a new flame retardant for polystyrene resin.

Here, tris(2,3-dibromopropylene) isocyanurate (hereinafter referred to as rTIcJ) itself has long been known as a flame retardant agent for other types of plastics, but this Until now, it has not been known at all that it is extremely advantageous for flame retardation.

As shown in the test examples below, this product imparted flame retardancy to polystyrene resin that cleared the UL94V2 standard, similar to hexabromocyclododecane (HBCD), even in a small amount of about 1%. As described above, since the amount required to be blended is small compared to other flame retardants, it does not easily affect the physical properties of molded products, and is also advantageous for producing high-magnification master pellets. In addition, unlike the latter (HBCD), its decomposition temperature is as high as 280°C, so there is no risk of deteriorating the processability of the resin.Furthermore, since the melting point of quartz is as low as 100°C, it can be used at the processing temperature of polystyrene resin. Since it is completely fluidized, uniform mixing is easy. Therefore, by utilizing these characteristics, it is easy to produce high-magnification master pellets in which the flame retardant and the pigment are closely blended in advance. Incidentally, since the market price of TIC is comparable to that of other flame retardants, it is also excellent in terms of economy in relation to the required amount of compounding.

The flame retardant of the present invention is usually blended with a relatively small amount of antimony trioxide and an arbitrary pigment as a flame retardant aid, but if necessary, it is formed into pellets together with an arbitrary pigment and a binder. Alternatively, these additives can be blended into a large amount of polystyrene to form master pellets.

The amount of antimony dioxide is usually 1 part of the main ingredient (TIC).
00 parts by weight to 50 to 10 parts by weight. These components are formulated so that when a certain amount is blended with the raw material polystyrene resin, the main agent, auxiliary agent, and pigment are in a predetermined ratio. Incidentally, if the base agent is added at a ratio of 1% or more to the resin, it will give the resin the flame retardancy necessary to comply with the above UL standards, but flame retardancy due to pigments, various processing aids, stabilizers, etc. Considering the decrease in properties, it is desirable that the content be 2% or more.

(Function) The flame retardant according to the present invention not only provides sufficient flame retardancy to the target polystyrene resin by adding a small amount, but also does not decompose at the workpiece temperature. Moreover, since it melts at a relatively low temperature, the viscosity decreases at the crosstalk temperature with the resin and it is completely dispersed in the resin. Another noteworthy effect is that the thermal deformation temperature of the resin is reduced by 5°C or more compared to when conventional flame retardants are used, so the temperature environment in which the resin can be applied can be greatly expanded.

In addition, since the amount added is smaller than that of conventional flame retardants, costs are also reduced.

(Example) The effects and embodiments of the invention will be explained below using test examples and formulation examples, but the examples are of course for illustrative purposes and are not intended to limit the idea of the invention.

Using a test piece made of a high-impact polystyrene base containing various flame retardants and an appropriate amount of antimony trioxide for the flame retardant, we used test pieces to meet the UL94V2 standard. The amounts (weight ratio) of various flame retardants added were determined. The results are shown in Table 1 below.

Table 1 As shown in the table above, the required amount of the invention TIC is 1% based on the resin, similar to HBCD.

Test Example 2 (Corrosion Test) 4 g of each of three types of flame retardants were placed in test tubes in oil baths heated to 200°C and 220°C, respectively.

Further, the iron pieces were suspended from above and heated for 10 minutes, after which each iron piece was taken out and the loss of heat of each flame retardant and the degree of corrosion of the iron pieces were examined. The results are shown in Tables 2 and 3 below.

(Margin below) Table-2 A book (-) indicates a decrease, and a (+) indicates an increase.

Table-3 Tomimoto○: No change.

Δ: (!1 Corrosion, surface gloss slightly reduced.

×: Corrosion is observed. There are some reddish brown deposits.

XX=Very severe corrosion, yellow and reddish brown deposits observed.

As is clear from Tables 2 and 3 above, TIC did not lose any weight on heating, and there was almost no corrosion of the iron pieces.

Test Example 3 (Strength Test) Three types of samples were examined for mechanical strength and physical properties. The results are shown in Table 4 below.

Table 4 Below: Impact resistant PS: None with other flame retardants of this sample: Normal PS: Impact resistant polystyrene mixed with 10% TBA and 0.5% antimony trioxide.

Invention: High-impact polystyrene mixed with 2.5% TIC and 0.5% antimony trioxide.

As shown in the above table, even though the flame retardant of the present invention is used, some deterioration in mechanical properties cannot be avoided, but the heat distortion temperature is still significantly improved compared to the conventional product using BA.

[Example 1] 100 parts by weight of impact-resistant PS resin (the same applies hereinafter) was added with TlC.
2.5 parts of antimony trioxide, 0.5 parts of antimony trioxide, and 0.2 parts of a tin-based stabilizer (dialkyl tin malate) were mixed uniformly. This was melted and kneaded using an extruder heated to 200" O, and the strand extruded from the nozzle was cut with a rotary cutter to form cylindrical granules. This impact-resistant PS resin composition complies with the UL94V2 standard. Adapted.

[Example 2] 300 parts of TLC, 6.0 parts of antimony trioxide, 3.6 parts of colorant, 5.4 parts of tin-based stabilizer, and 3.6 parts of dispersion aid were added to 514 parts of powdered impact-resistant PS resin. and mixed uniformly. This was melted and mixed in a twin-screw extruder heated to 200°C, and then extruded and cut in the same manner as in the previous example to obtain master pellets.

For 1 part of the above master pellet, granular impact resistance P
After mixing 11 parts of S resin, the molded product obtained by injection molding is UL
It showed flame retardancy meeting the 94V2 standard. Therefore, the granular composition of this example is a 12x master pellet for simultaneously imparting flame retardance and color to impact-resistant PS resins.

(Effects of the Invention) As explained above, the present invention can provide an economical flame retardant means for polystyrene that has little deterioration in physical properties and does not cause damage to equipment such as molds and molding machines. This can contribute to the development of related industries and disaster prevention.

Claims (4)

[Claims] (1) A flame retardant for polystyrene containing tris(2,3-dibromopropylene) isocyanurate as an active ingredient. (2) 50 to 50 parts of antimony trioxide to 100 parts by weight of tris(2,3-dibromopropylene) isocyanurate
The agent according to claim 1, which is contained in an amount of 10 parts by weight. (3) The agent according to claim 1 or 2, which is pelletized together with antimony trioxide, a dye, etc. (4) A polystyrene composition containing tris(2,3-dibromopropylene) isocyanurate as a flame retardant component.