JPS6395249A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To provide the titled composition outstanding in transparency, mechanical properties and moldability, suitable for electric and electronic parts, etc., consisting mainly of a copolymer constituted of methyl methacrylate units and bisalkyl vinyl phosphonate compound units. CONSTITUTION:The objective composition can be obtained by blending (A) 70-95pts.wt. of a copolymer with an intrinsic viscosity 0.03-0.1l/g constituted of A1: 70-95wt% of methyl methacrylate units and A2: 30-5wt% of bisalkyl vinyl phosphonate compound units of formula I [R is -CnH2n- (n is 1, 2 or 3); X1-X3 are each H or Cl; X4 is Cl or Br] [e.g., bis(beta-chloroethyl)vinyl phosphonate], (B) 0-15pts.wt. of a compound with a melting point 90-210 deg.C of formula II (X5 and X6 are each H, etc.; Y is -CH2CH2-, etc.) or formula III (X7 and X8 are each H, etc., Z is of formula IV, etc.), and (C) 0-25pts.wt. of a brominated aromatic compound with a melting point 90-210 deg.C (e.g., tetrabromobisphenol A) so as to total 100pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a flame-retardant thermoplastic resin composition having excellent transparency and mechanical properties and good moldability.

[Summary of the invention]

The present invention is a flame retardant resin composition containing as a main component a copolymer obtained by copolymerizing a methyl methacrylate monomer and a specific type of vinyl phosphonate monomer. , it is possible to obtain a resin composition with excellent flame retardancy without impairing the excellent properties inherent to methacrylic resin.

[Problems to be solved by the conventional technology and the invention] Methacrylic resin has excellent transparency, excellent weather resistance,
Due to its good mechanical properties and heat resistance, it is widely used in lighting materials, signboards, displays, building materials, electrical and electronic equipment parts, OA equipment parts, automobile parts, etc., but its application fields are limited due to its flammability. is restricted.

It is already known that flame retardancy can be imparted to methacrylic resin by adding a certain type of organic phosphate ester as an additive flame retardant. However, these organic phosphate esters generally have a plasticizing effect, and have an adverse effect on the physical properties of the resulting methacrylic resin molded product, such as significantly lowering the heat distortion temperature and greatly reducing the mechanical strength. Furthermore, when molded at a constant temperature of 200° C. or higher, there were problems with moldability such as significant coloring.

In addition, the water absorption of the resulting resin composition increases significantly due to the added organic phosphate ester, so flame-retardant molded products using this composition cannot absorb water when used outdoors, for example. This often causes problems such as deformation and crazes. Furthermore, most of these organic phosphoric acid 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.

On the other hand, various types of halogen-based flame retardants, particularly brominated aromatic compounds, are commercially available as other additive flame retardants. However, when these flame retardants are added to methacrylic resin, their flame retardant effect is inferior to that of the above-mentioned organic phosphate ester compounds, and since they require addition in large amounts, they significantly reduce 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 great flame retardant properties simply because the content of halogen or phosphorus in the substance is high; The greater the amount of halogen or phosphorus present, 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, and therefore unexpected flame retardant effects can be achieved by combining several different flame retardant agents. Sometimes.

On the other hand, several methods have been proposed in which methyl methacrylate and flame retardant monomers are copolymerized, but these methods may result in a significant decrease in heat resistance, increased water absorption, or coloration, making them unsatisfactory. At present, no resin composition has been obtained.

Furthermore, when handling transparent resin, the coloring of the resin has a significant impact on the product value. It is thought that the degree of coloring is related to the same or even more complex factors than in the case of imparting flame retardancy, and a combination of specific additives may produce unexpected effects.

The purpose of the present invention is to improve the above-mentioned drawbacks of conventional flame-retardant acrylic resins and to obtain a flame-retardant thermoplastic resin composition having excellent transparency, mechanical properties, and good moldability. It is in.

[Means for solving problems]

In view of this situation, the inventors of the present invention have conducted extensive studies on flame-retardant resin compositions that have excellent transparency and mechanical properties and have good moldability, and as a result, have completed the present invention.

That is, the present invention has 70 to 9 methyl methacrylate units.
5% by weight and formula (1)% formula% (1) (wherein R represents 10-Hz-(n is l, 2 or 3), Xl-Xl represents H or (J,
represents CII or Br. ) is a flame-retardant resin composition whose main component is a copolymer (A) consisting of 30 to 5% by weight of bisalkyl vinyl phosphonate compound units.

The copolymer (A) used in the present invention is obtained by copolymerizing each component of the methyl methacrylate unit and the bisalkyl vinyl phosphonate monomer unit of the above formula (1) by various conventionally known methods such as bulking, suspending, etc. You can get it.

This copolymer (A) has an intrinsic viscosity [η] of 0.03 to 0.14 when measured in chloroform at 25°C! /g is preferred.

If the content of methyl methacrylate units in the copolymer (A) is less than 70% by weight, the optical, mechanical properties and heat resistance of the resulting flame-retardant resin composition will deteriorate, which is undesirable, while if it exceeds 95% by weight. This is undesirable because the fluidity, that is, the processability, deteriorates, and it becomes necessary to use a large amount of an additive flame retardant, which tends to deteriorate the physical properties.

As the compound of formula (1), bis(β-chloroethyl)vinylphosphonate is particularly preferable, and in addition, bis(β-chloroethyl)vinylphosphonate is preferable.
β-chloropropyl) vinyl phosphonate, bis(β-
chloroethyl) 2-chlorovinylphonate, bis(β-
Bromoethyl) vinyl phosphonate, bis(β-chloroethyl) 2°2-dichlorovinyl phosphonate, and the like.

Other copolymerizable monomers can be added to the copolymer (A) in an amount of 20% by weight or less. The copolymerizable monomers include α-methylstyrene; alkyl methacrylates such as ethyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate; alkyl acrylates such as methyl acrylate, ethyl acrylate, and butyl acrylate; Esters; vinyl cyanide monomers such as acrylonitrile and methacrylonitrile; unsaturated acid esters such as methyl cinnamate and methyl crotonate; acid anhydrides such as maleic anhydride; N-cyclohexylmaleimide, N- Phenylmaleimide, N-(o-chlorophenylmaleimide), N
- maleimides such as ethylmaleimide; etc. can be used alone or in combination. Furthermore, resins obtained by imidizing these resins by polymer reaction or rubber-modified resins can also be used.

The copolymer (A) has sufficient flame retardancy even when used alone, but if necessary, a small amount of an additive type flame retardant can be used in combination, thereby achieving excellent transparency and mechanical properties. A flame-retardant resin composition can be obtained, that is, the flame-retardant resin composition of the present invention preferably contains copolymer (A) 70
~95 parts by weight, formula (2) (wherein, X and X are each HSBr or C1
, Y is -CH2CHt-1(CHz)s-1
CHz C(CH3) zCHt-2-CHyo-C(
CHz C1) t CHz- or 10 Ht C
(CHz Br)z represents CHz-, ) or formula (3) (wherein X7 and X days are H, Br or CI, respectively)
, Z represents ) and has a melting point of 90 to 210°C, preferably 100 to
0 to 15 parts by weight of at least one compound (B) at 200°C and a melting point of 90 to 210°C, preferably 100 to 1
At least one kind of brominated aromatic compound (C) θ at 90°C
~25 parts by weight, copolymer (A), compound (B)
and brominated aromatic compound (C) is 100 parts by weight, and more preferably the ratios of (A), (B) and (C) are 70 to 95 parts by weight, 2 to 15 parts by weight, and 3 to 20 parts by weight, respectively. Parts by weight.

If the copolymer (A) is less than 70 parts by weight, the surface hardness of the resin molded product obtained tends to be low, the chemical resistance tends to decrease, and the decrease in mechanical strength becomes relatively large.

Among the compounds (B) represented by the above formula (1) or (2), as disclosed in U.S. Pat. It is known that there is. However, in general, when these are mixed and used alone, there are problems such as coloring, increased water absorption, or poor fluidity during molding.

As a preferred example of the present invention, when the compound (B) is blended with the copolymer (A), flame retardation can be achieved with a smaller amount than when blending with the methacrylic resin.

When compound (B) is used, if its melting point is less than 90°C, the heat resistance of the resulting resin composition will decrease, the resin surface will tend to develop tackiness, and the mixture mixed by triblend may At the stage of extruding an object, problems such as unstable ejection, venting, and poor penetration occur, which is undesirable.

On the other hand, if the melting point exceeds 210° C., the compatibility with the copolymer (A) tends to decrease, and the optical properties of the obtained flame-retardant resin composition decrease, which is not preferable.

When using compound (B), if the amount is less than 2 parts by weight out of 100 parts by weight of the total resin composition obtained, the flame retardant effect will be low, and if it exceeds 15 parts by weight, coloring will be significant and water absorption will also be high. There is a tendency to

The object of the present invention can be achieved by using compound (B) as an example of the M fuel that is added as necessary, but
When considering industrial production taking into consideration the availability and price of flame retardants, it is also possible to use a bromine compound aromatic compound (C) in combination with compound (B) as a flame retardant other than the compound (B). It can also be used alone. Representative examples of the brominated aromatic compound (C) include tetrabromobisphenol A, its derivatives, and brominated biphenyl oxides, and one or more of these can be used.

When blending the brominated aromatic compound (C), if the amount added exceeds 25 parts by weight, the mechanical strength of the resulting resin composition will decrease, which is not preferable.

In this way, even if the brominated aromatic compound (C) is used instead of the compound (B), substantially the same flame retardant effect can be maintained. It is suitable for these brominated aromatic compounds (C) to have a melting point within the range specified above in order to obtain the flame-retardant resin composition of the present invention having excellent optical properties and mechanical properties. , the reason is the same as in the case of compound (B).

Note that the compound (B) and the brominated aromatic compound (C) may not be a single compound but may contain by-products depending on the manufacturing method. In such cases, these compounds are used after being purified or otherwise treated so that their melting points fall substantially within the range defined above.

The resin composition of the present invention may contain small amounts of other additives such as a mold release agent, a stabilizer, a coloring agent, an ultraviolet absorber, a light dispersing agent, etc., as long as the object of the present invention is not impaired. In particular, when an additive type flame retardant, that is, a compound (B) and/or a brominated aromatic compound (C) is used together, a phosphite compound having a melting point of 40 to 210°C is added to 100 parts by weight of the resin composition as a stabilizer. When used in the range of 0.05 to 3 parts by weight, a synergistic effect with the flame retardant can be exhibited and coloration can be reduced, so it is more preferable. This is not preferable because it lowers the temperature. If a large amount of a phosphite compound with a melting point of less than 40°C is blended, the surface of the resulting resin composition will become sticky, and if the phosphite compound has a melting point of more than 2()0°C, the resulting resin composition will have poor compatibility. This is undesirable because the transparency of the film decreases.

Some preferred phosphite compounds are illustrated below, but are not limited thereto.

Pentaerythritol water-added bisphenol A triphenyl phosphite polycondensate (existing chemical substance ?-190
0, mp, 98°C, manufactured by Kenka Kagaku Kogyo, JPH-380
0), tris(2,4-di-t-butylphenyl) phosphite (mp, 170-190°C, manufactured by Adeka Argus Chemical Co., Ltd.,
n+ark2112), water-added bisphenol A phosphite polymer (mp, 70-80℃, Kenka Kagaku Kogyo ■
Bisphenol A pentaerythritol phosphite) (mp, 98°C, manufactured by Kenka Kagaku Kogyo ■, JPP-3300), allyl diphosphite (mp, 110-120°C, manufactured by Adeka Argus Chemical ■, markPEP- 2), distearylpentaerythrityl diphosphite) (mp,
40-50℃, existing chemical substances 5-1081 manufactured by Johoku Chemical Industry ■, JPP-2000, manufactured by Adeka Argus Chemical ■,
mark P E P -8), various methods can be adopted for adding the compound (B), the brominated aromatic compound (C), and the phosphite compound to the copolymer (A), but the melting point of each component Since these materials are used in relatively close ranges, the method of mixing in a tumbler or Henschel mixer and then uniformly mixing in an extruder is the simplest method and has excellent productivity. In addition, as an addition method, a hot roll, a Banbury mixer, etc. can also be used. In addition, the compound (B) and/or the brominated aromatic compound (
The desired resin composition can also be obtained by dissolving C) and performing bulk or suspension polymerization.

〔Effect of the invention〕

The resin composition obtained by the present invention has excellent flame retardancy and optical and mechanical properties, so it can be used in electronic and electrical parts, OA
It is useful for applications such as equipment parts, automobile parts, building materials, signboards, and glazing materials.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. In addition, in the following description, parts indicate parts by weight.

Characteristic evaluations in Examples were performed based on the following method.

(1) Tensile strength and elongation ASTM-D-638 (2) Izot impact strength ASTM-D-256 (mild notch) (3) Heat distortion resistance Heat distortion temperature (HDT) ('C) ASTM-D-648 (4 ) Total light transmittance and haze value ASTM-D-1003 (plate thickness 2 cranes) (5) Intrinsic viscosity Measured and determined in chloroform at 25°C.

(6) Color tone and transparency of injection molded plate It was determined by visual inspection.

(7) Weather resistance accelerated exposure test 240 hours, temperature 60 with Suga's weather resistant machine
The test was carried out under the conditions of 12 minutes of rain per hour using a carbon arc lamp.

(8) Flammability Evaluated by vertical method in accordance with U.S. UL standard 5ubject 94.

The thickness of the test piece was 1.5 days or 3D.

(9) Composition analysis of compounds Phosphorus was measured by the absorbance method using molybdenum blue, and chlorine and bromine were measured by the absorbance method using Rodan mercury according to conventional methods.

Production of charcoal copolymer and polymer: Copolymers (A-1) to (A-3) used in the examples below
Copolymers (D) and polymers (E) used in comparative examples to be described later were also produced in the following manner.

3 kg of deionized water, 0.3 g of a copolymer of methyl methacrylate and sodium salt of 2-sulfoethyl methacrylate as a dispersant, and 9 g of sodium sulfate were charged into a polymerization kettle with an internal volume of 51 mm and equipped with a stirrer.

Next, monomer-containing mixture 1 having the composition shown in Table 1 below
．． 5 kg was added, nitrogen was bubbled to substantially eliminate oxygen, suspension polymerization was carried out at 80°C, and after confirming the peak temperature, heat treatment was performed at 95°C for 30 minutes, cooled, washed, and dried to form copolymerized beads. A combination and a polymer were obtained.

(The following margins are continued on the next page.) Production of Compound (B): The following compounds (B-1) and (B-2) were produced according to the description in U.S. Patent No. 4.458.045.

(B-1) (B-2) Measure the melting points and contents of phosphorus and halogen atoms of these compounds (B-1) and (B-2), and share the results with the
Shown in the table.

Table 2 Brominated aromatic compound (C): The following commercial products were used as they were.

(C-1) Tetrabromobisphenol Amp, 1
78-181℃, Fire Guard 2000 Teijin Chemicals ■
Manufactured by Asahi Glass (C-2) mp, 115-118℃, APR-1011, Asahi Glass (C-3) mp, 90-105℃, Fireguard 3100
Teidai Kasei ■ (C-4) octabromodiphenyl oxide mp,
90 to 105°C After blending each component in the proportions shown in Table 3 and mixing in a tumbler, use a twin screw extruder (PCM-30) manufactured by Ikegai Tekko ■ to the cylinder temperature shown in Table 3. and vent pressure 5
~l Q m+aHgabs, and pelletized.

These pellets were injection molded using a V-17-65 automatic injection molding machine made by Japan Steel Works, Ltd. at the cylinder temperature and mold temperature of 60°C shown in Table 3, and the various test pieces obtained were Used for evaluation. The evaluation results are shown in Table 4.

(The following margins are continued on the next page.) 509 earth methyl methacrylate 78 parts Brominated aromatic compound (C-1) 12 parts lauroyl peroxide 0.08 parts M-octyl mercaptan 0.35 parts or more The monomer-containing mixed liquid was injected into several sets of cells each formed by two opposing tempered glass plates via a gasket, and was immersed in warm water at 65°C to polymerize and harden. After that, it was treated in an air heating oven at 110℃ for 2 hours, and after cooling, the cell was removed and the thickness was about 3cm.
A resin plate of a crane was obtained.

This resin plate is colorless and transparent, and has an intrinsic viscosity of 0.041/
g, and the results of the combustion test were at the V-2 level.

Additionally, this resin board has a total light transmittance of 91% and a haze value of 3.
2% and HDT was 81'C.

A bead-shaped copolymer was produced in exactly the same manner as in the production of copolymer (A-1) except that the composition of the mixture containing the Daishi-goko monomer was changed as follows.

Methyl methacrylate 80 parts Brominated aromatic compound (C-1) 13 parts Azobisisobutyronitrile 0.1 part n-octyl mercaptan
0.25 parts Stearic acid monoglyceride 0.1 parts This bead-like copolymer was extruded in exactly the same manner as in Example 1,
It was molded and the following results were obtained.

Appearance Colorless and transparent Flammability V-2 HDT 80℃ Tensile strength 650kg/aJ Tensile elongation
3.5% Izot impact strength 1.3 kg-cab/aa tip Got the results.

Weather resistance was evaluated using the test piece of Example 9, but no craze was observed and almost no coloring was observed.

Claims (1)

[Claims] 1. 70 to 95% by weight of methyl methacrylate units and formulas ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (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. ) 30 to 5 bisalkyl vinyl phosphonate compound units represented by
% by weight of a copolymer (A) as a main component. 2. The bis-alkyl vinyl phosphonate compound is bis(β
The flame-retardant resin composition according to claim 1, which is vinyl phosphonate (chloroethyl). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, X_5 and X_6 each represent H, Br, or Cl, and Y represents -CH_2CH_2-, -(CH_
2)_3-, -CH_2-C(CH_3)_2-CH_
2-, -CH_2-C(CH_2Cl)_2CH_2-
or -CH_2-C(CH_2Br)_2CH_2-
represents. ) or formula ▲ There is a mathematical formula, chemical formula, table, etc. ▼ (In the formula, X_7 and X_8 each represent H, Br or Cl, and Z is 0 to 15 parts by weight of at least one compound (B) represented by ▼ and having a melting point of 90 to 210°C and a melting point of 90 to 210°C
At least one brominated aromatic compound (C) of 0 to 25
The flame-retardant resin composition according to claim 1, wherein the total amount of the copolymer (A), the compound (B) and the brominated aromatic compound (C) is 100 parts by weight. 4. The proportions of the copolymer (A), the compound (B) and the brominated aromatic compound (C) are 70 to 95 parts by weight, and 2 to 95 parts by weight, respectively.
The flame retardant resin composition according to claim 3, wherein the amount is 15 parts by weight and 3 to 20 parts by weight. 5. The flame retardant according to claim 3, wherein the brominated aromatic compound (C) is at least one compound selected from the group consisting of tetrabromobisphenol A, brominated biphenyl oxide, and derivatives thereof. resin composition.