JPS63152609A - Flame-retardant resin - Google Patents

Abstract

PURPOSE:To obtain a resin having excellent flame retardance as well as optical and mechanical properties, by copolymerizing a monomeric mixture consisting of specific amounts of styrene, methyl methacrylate and bisalkylvinyl phosphonate compound. CONSTITUTION:A monomeric mixture consisting of 20-80wt% styrene, 15-75wt% methyl methacrylate and 5-30wt% bisalkylvinyl phosphonate compound expressed by the formula [R is -CnH2n- (n is 1, 2 or 3; X1-X3 are H or Cl; X is Cl or Br], e.g. bis(beta-chloroethyl)vinyl phosphonate, etc., is copolymerized to afford the aimed flame-retardant resin having preferably 0.03-0.1l/g intrinsic viscosity [eta] measured in chloroform at 25 deg.C. This resin is used for electronic and electric parts, OA device parts, building materials, signboards, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of application in the industry] The present invention relates to a flame-retardant resin having excellent transparency, mechanical properties, and good bottom shape, and more specifically relates to a flame-retardant resin having excellent transparency, mechanical properties, and good bottom shape.
The present invention relates to a flame-retardant resin with excellent transparency, mechanical properties, and moldability obtained by copolymerizing a methyl methacrylate monomer and a specific type of vinyl phosphonate monomer.

[Prior Art] Due to its outstanding transparency, excellent weather resistance, excellent mechanical properties, and heat resistance, methacrylic resin is used in lighting materials, signboards, displays, building materials, electrical and electronic equipment parts, and OA.
Although it is widely used in equipment parts, automobile parts, etc., its field of application is limited due to its flammability.

As a method of imparting flame retardancy to methacrylic resin, (1) adding a certain type of organic phosphate ester as an additive flame retardant to methacrylic resin; (2) adding halogen-based flame retardants as other additive flame retardants; In particular, methods such as adding a brominated aromatic compound (3) and copolymerizing methyl methacrylate and a flame retardant monomer are known.

[Problem that the invention seeks to solve]

However, the organic phosphoric acid ester used in the method (1) above generally has a plasticizing effect, which significantly reduces the thermal deformation thermal stability of the resulting methacrylic resin molded product and also greatly reduces the mechanical strength. Additions have a negative effect on the physical properties of the molded product, and also have problems with moldability such as significant coloring when the bottom shape is kept at a constant temperature of 200C or higher.Additionally, the water absorption of the resulting resin composition is The concentration significantly increases due to the organic phosphate ester
When a flame-retardant bottom shaped article using this composition is used outdoors, for example, it absorbs water and deforms, causing crazes, which often poses a problem. Furthermore, most of these organic heptacid esters are liquid at room temperature, which poses an operational problem in that they are difficult to handle during the blending with resin and extrusion stages.

In addition, when the nitrogen-based flame retardant used in method (2) is added to the methacrylic resin, the flame retardant effect is lower than that of the organophosphoric acid ester compound described above, and a large amount is required to be added. Significantly reduces the mechanical strength and heat resistance of molded products. While styrene resins can be made flame retardant by adding relatively small amounts of brominated aromatic compounds, this difficulty in making methacrylic resins flame retardant is considered to be one of the drawbacks of methacrylic resins. Ta.

A flame retardant agent containing halogen or phosphorus does not necessarily have a high flame retardancy simply because the content of halogen or phosphorus in the substance is high. The greater the amount of halogen or phosphorus present in a substance, the greater the effect does not necessarily mean. Furthermore, even if the type and number of atoms constituting a compound are the same, if the structure is different, the flame retardant effect will also be different, and the effect of imparting flame retardancy cannot be generally predicted. Flame retardancy is the result of a combination of complex factors; therefore, unexpected flame retardant effects can be achieved by combining several different flame retardant agents. Sometimes.

On the other hand, the copolymers obtained by copolymerizing methyl methacrylate and flame-retardant monomers, which have been proposed in the past (9) (3), have significantly reduced heat resistance or increased water absorption. At present, a resin composition that is colored and satisfactorily has not been obtained.

[Next Means to Solve the Problems] In view of this situation, the present inventors have conducted extensive studies to obtain a flame-retardant resin that has excellent transparency and mechanical properties, and has good moldability. As a result, the present invention was completed.

That is, the present invention contains 20 to 80% by weight of steel V, 15 to 75% by weight of methyl methacrylate, and the following formula:
0% Formula % (1) (In the formula, R represents -cnumn (n ha1 + 2 or 6), XI to x3 each represent H or at, and x4 represents ctt or Bri.) It is a flame-retardant resin obtained by combining a monomer mixture consisting of the bisalkyl vinyl phosphonate compounds 5 to 30i shown below.

In the present invention, the proportion of styrene used is 20 to 80% by weight; if this proportion is less than 20% by weight, the flame retardancy and moldability of the resulting copolymer tend to decrease;
If it exceeds 80% by weight, optical properties tend to deteriorate.

Furthermore, if the proportion of methyl methacrylate used is less than 15% by weight, a decrease in optical, mechanical properties and heat resistance will be observed, while if it exceeds 75% by weight, fluidity, that is, moldability will decrease, and addition mold release will be observed. Physical properties tend to deteriorate, such as the need to use a fuel in combination.

On the other hand, as the alkylvinylphosphonate compound of the above formula, bis(β-chloroethyl)vinylphosphonate is particularly preferable, and bis(β-chloropropyl)
Vinylphosphonate, his(β-chloroethyl)2-chlorovinylphonate, bis(β-glomoethyl)vinylphosphonate, bis(β-chloroethyl)2,2-dichlorovinylphosphonate, etc. are listed, and this bisalkylvinylphosphonate compound If the proportion used is less than 5 parts by weight, the flame retardant effect will be small, and if it exceeds 30 parts by weight and 11 inches, the heat resistance will tend to decrease. The preferred range is 5
~20 weight class.

In the present invention, other copolymerizable monomers may be used in an amount of up to 20% by weight, if necessary.

The copolymerizable monomers include vinyltoluene, a-methylstyrene; methacrylic acid alkyl esters such as ethyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate; methyl acrylate, ethyl acrylate, acrylic [phthyl, etc.] Acrylic acid alkyl esters: Vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; Unsaturated acid esters such as methyl cinnamate and methyl crotonate: Acid anhydrides such as maleinoic anhydride diN-
Cyclohexylmaleimide, N-phenylmaleimide,
Maleimides such as N-(o-chlorophenylmaleimide) and N-ethylmaleimide can be used alone or in combination.

The copolymer of the present invention can be obtained by copolymerization using a conventionally known bulk polymerization method or suspension polymerization method. In addition, in order to give this copolymer even better moldability, it is preferable that the intrinsic viscosity [η] measured in chloroform at 25° C. be in the range of α03 to α1L/f.

The copolymer of the present invention can be used as is as an II flame retardant resin, but if necessary, an additive flame retardant may be used in an amount of 20 parts by weight per 100'X parts of the copolymer. . Examples of preferable additive flame retardants in this case include compounds represented by the following formula (1) and brominated aromatic compounds such as tetrabromobisphenol A (in the formula, xs and xs respectively represent jLH, Br and at, Y is 10TI, OH!-1 CC
Hz)s=, OHz -0(OHs) z OH
z-1OHz O(OHriat) MaroOH! -Makuha-
OH, -0 (mouth H2Br) represents 20 Hz-.

) (where X7 and xs are H, Brl or at, respectively)
2 represents . ) The additive flame retardant described above preferably has a melting point of 90 to 210° C. from the viewpoint of ease of passing through processes such as blending with a copolymer.

Next, the resin composition of the present invention may contain a pear release agent, a stabilizer, a coloring agent, an ultraviolet absorber,
Other additives such as light dispersants can be used in small amounts.

Various methods can be used to add the additive flame retardant and other additives to the copolymer, but the most effective method is to mix them in a tumbler or Henschel mixer and then mix them uniformly in an extruder. It is simple and has excellent productivity. In addition, as an addition method, a hot roll, a Banbury mixer, etc. can also be used.

(9) When producing a copolymer, it is also possible to obtain the desired flame-retardant resin by dissolving it in a monomer and using a known polymerization method.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, in the following description, "part" indicates "part by weight", and "chi" indicates "1! quantity".

Characteristic evaluations in the examples were performed based on the following methods.

(1) Tensile strength and elongation A8TM-D-658 (2) Izot impact strength ASTM-D-256 (mild notch) (3) Heat deformation resistance Heat distortion temperature (HD T ) C℃) ASTM-D-648 (4 ) Total light transmittance and haze value ASTM-D-1003 (Plate JiL2 simple) (5) Intrinsic viscosity Measured and determined in chloroform at 25°C.

(6) Color tone and transparency of injection molded plate Determine by visual inspection.

(7) Weather Resistance Accelerated Exposure Test Tests were conducted for 240 hours using a weather tester manufactured by Suga Co., Ltd. at a temperature of 60°C, under the conditions of Carpon Poke lighting and 912 minutes of rain per hour.

(8) Flammability Evaluated by vertical method in accordance with U.S. UL standard Su'ject 94.

The thickness of the test piece was 1.5 W, and the thickness of the sample was 3. The composition analysis of the compound (9) was carried out by an absorbance method using molybdenum blue, and chlorine and bromine were measured by an absorbance method using Rodan mercury according to a conventional method.

The following additive flame retardants were used.

[A] The following compound was produced according to the method described in US Pat. No. 4.45a045.

The melting point of this compound is 183-188°C, and the phosphorus content is 1
52. Chlorine content is 15. ．． It was 1ch.

[Mouth] Use the following tetrabromobisphenol as is as the brominated aromatic.

Fire Guard 2000 (manufactured by Konjinka (underfloor, melting point 17)
Production of 8-b copolymers and polymers: Copolymers (A-1) to (A-3) used in Examples described later
Copolymer CB) and polymer (0) Th used in the comparative examples described later were placed in a polymerization pot with a stirrer and having an internal volume of 5 L as follows: 5 liters of deionized water and 2 ml of methyl methacrylate as a dispersant. - Copolymer α3f of sulfoethyl methacrylate with sodium salt and 9ff of sodium sulfate were charged. Next, 1.5 liters of the nine monomer-containing mixtures shown in Table 1 below were added, nitrogen was bubbled through to substantially exclude oxygen, suspension polymerization was carried out at 80°C, the peak temperature was confirmed, and the mixture was Heat treatment was performed at 95° C. for 30 minutes, followed by cooling, washing, and drying to obtain bead-shaped copolymers and polymers.

Table 1 Examples 1 to 4 and Comparative Examples 1 to 3 Each fraction was blended in the proportions shown in Table 1, mixed in a tumbler, and then heated in a twin screw extruder (POM-1 manufactured by Ikegai Tekko Co., Ltd.). 30
) at the cylinder temperature and pent pressure of 5 to 10 wm Hgaba shown in Table 3 to pelletize.

The pellets were injection molded using a V-17-65 type screw automatic injection molding machine made by Japan Steel Works at the cylinder temperature and mold temperature of 0°C shown in Table 2, and the various test pieces obtained were evaluated. A friend used for. The evaluation results are also listed in Table 2.

A weather resistance evaluation was conducted using the test pieces of Examples 1 and 4, and the results showed that no formation of V-z was observed, and almost no coloration was observed.

Next, mechanical properties were evaluated using the test pieces of Examples 1 and 3, and the results shown in Table 3 were obtained.

Table 3 Example 5 Styrene 20 parts Methyl methacrylate 60 parts Phosphonate Fireguard 2000 12 parts Lauroyl peroxide 1109 tons
- A monomer-containing mixed solution having a composition of α4 parts or more of dodecyl mercaptan is injected into several sets of cells formed using two tempered glass plates facing each other via a gas foot, and immersed in warm water at 65°C. The polymer was cured by polymerization.

After that, it was treated in an air heating furnace at 110° C. for 2 hours, and after cooling, the cell was removed to obtain a resin plate with a thickness of about 6 mm.

This resin plate is colorless and transparent, and has an intrinsic viscosity of α051/l.
The result of the combustion test was V-2 level. '
j7c, this resin plate has a total light transmittance of 90%, a haze value of 55%, and an HDT of 84°C.

Example 6 All except that the composition of the monomer-containing mixture was as follows.
An experiment was carried out in the same manner as in Example 5, and a resin plate with a thickness of about 3 mm was obtained.

Styrene 70 parts Methyl methacrylate 15 parts Bis(β-chloroethyl)vinylphosphonate 15 parts Lauroyl peroxide [115 parts t-dodecylmercaptan 13 parts Aerosol OT
(102 parts) This resin board is colorless and transparent, and the result of the combustion test was V-2 level.
I hope it's 8℃.

[Effects of the Invention] The resin composition obtained by the present invention has excellent flame retardancy and optical and mechanical properties.
It is useful for applications such as equipment parts, auto parts, building materials, signboards, and glazing materials.

Claims (2)

[Claims] (1) Styrene 20-80% by weight, methyl methacrylate 15-75% by weight, and the following formula ▲ Numerical formula, chemical formula, table, etc. ▼... (1) (In the formula, R is -C_nH_2_n- (n is 1 , 2 or 3
), X_1 to X_3 each represent H or Cl, and X_4 represents Cl or Br. ) A flame-retardant resin obtained by copolymerizing a monomer mixture consisting of 5 to 30% by weight of a bisalkyl vinyl phosphonate compound represented by the following formula. (2) The flame-retardant resin according to claim 1, wherein the bisalkyl vinylphosphonate is bis(β-chloroethyl)vinylphosphonate.