JPH02202544A - Flame-retardant polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain the nonpoisonous title composition exhibiting improved flame-retardant characteristics and capable of providing a molded article having good transparency and reduced in color change by blending an aromatic sulfonic acid metal salt with an alkylene glycol oligomer. CONSTITUTION:The aimed composition obtained by adding 0.01-2.0 pts.wt., preferably 0.05-1.5 pts.wt. (substituted) aromatic sulfonic acid metal salt and 0.01-3.0 pts.wt., preferably 0.05-2.0 pts.wt. alkylene glycol oligomer having 200-1000 molecular weight to 100 pts.wt. aromatic polycarbonate resin. As the aromatic sulfonic acid metal salt, sodium diphenylsulfonesulfonate or potassium diphenylsulfonesulfonate is used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a polycarbonate resin composition that has improved flame retardancy without impairing the inherent characteristics of the polycarbonate resin.

[Conventional technology]

Polycarbonate resins are transparent, have excellent impact resistance, are non-porous, and have excellent dimensional stability, and therefore have many uses as engineering plastics.

Polycarbonate resin itself also has fairly high flame retardant properties. However, there is a strong demand for resin compositions with even higher flame retardancy in order to meet safety requirements in various applications.

In order to meet such requirements, techniques are known in which certain metal salts and other flame retardants are added to polycarbonate resins.

JP-A-63-215763 discloses that in addition to ortho-methyl substituted aromatic dihydroxy compounds, aromatic sulfonic acid metal salts and aromatic sulfone sulfonic acid metals are used to make aromatic polycarbonate resin flame retardant. Mixing salts or perfluoroalkyl sulfonic acid metal salts has been disclosed, but the heat stability is insufficient and discoloration is likely to occur during molding. Further, in US Pat.
0,000 polyether polyol and metal salt (NaB
Although it has been disclosed to add a complex with r), the preparation of the complex is cumbersome.

Further, flame retardants containing a large amount of halogen atoms are well known, but they are not preferred because they cause harm due to the gases generated during combustion.

[Problem to be solved by the invention]

An object of the present invention is to provide an aromatic polycarbonate resin composition that has improved flame retardant properties, provides molded articles with good transparency, and exhibits little discoloration.

[Structure of the invention]

In the present invention, 0.01 to 2.0 parts of unsubstituted or substituted aromatic sulfonic acid metal salt or metal perfluoroalkyl sulfonate is added to 100 parts by weight of the aromatic polycarbonate resin.
0 parts by weight and a molecular weight of 200 to i,oo.

alkylene glycol oligomer 0.01 to 3.0
This is a polycarbonate resin composition characterized by adding parts by weight.

According to the flame-retardant polycarbonate resin composition of the present invention, improved flame retardance can be easily achieved while maintaining mechanical strength, thermal stability during processing, and transparency, which are the original important characteristics of polycarbonate resin. can be obtained. Further, since the additive used here does not contain a large amount of halogen atoms, problems such as metal corrosion and danger to humans and animals due to combustion gas are extremely rare.

In the present invention, an unsubstituted or substituted aromatic sulfonic acid metal salt or a perfluoroalkyl sulfonic acid metal salt is mixed with the aromatic polycarbonate. The substituents here can be halogen atoms, such as chlorine, bromine and fluorine atoms, alkyl groups, or halogen-substituted alkyl groups. Metal salts are, for example, alkali metal salts (especially sodium or potassium salts) or alkaline earth metal salts. A particularly preferred example of such a compound is potassium diphenylsulfonesulfonate.

The amount of the sulfonic acid metal salt is 0.01 to 2.0 parts by weight per 100 parts by weight of the aromatic polycarbonate;
Preferably it is 0.05 to 1.5 parts by weight. If the amount is less than this range, sufficient flame retardancy cannot be obtained, whereas if the amount is more than this, mechanical properties, thermal stability, and processability during molding will deteriorate.

The aromatic polycarbonate resin composition of the present invention is further mixed with an alkylene glycol oligomer having a molecular weight of 200 to 1,000. Examples of alkylene glycol oligomers include oligomers of polyethylene glycol, polypropylene glycol, and polybutylene glycol. If the molecular weight is less than 200, the polyalkylene glycol tends to ooze out from the molded product, which is not preferable.

On the other hand, when the molecular weight exceeds t, ooo, the transparency of the molded article decreases. The amount of alkylene glycol oligomer is 0.01 to 3.0 parts by weight, preferably 0.05 to 2.0 parts by weight, based on 100 parts by weight of aromatic polycarbonate. If the amount is less than this range, sufficient flame retardancy will not be obtained, whereas if it is more than this, mechanical strength will decrease.

Although the alkylene glycol oligomer itself does not have flame retardancy, by adding it together with the above-mentioned sulfonic acid metal salt, the polycarbonate resin composition has sufficiently high flame retardancy, especially non-dripping properties during combustion. can be easily prepared, and at the same time, the desired purpose can be achieved without any deterioration of the inherent properties of the resin, such as mechanical strength, heat resistance, transparency, etc. can.

Aromatic polycarbonate resins used in the present invention can be made by reacting dihydric phenols with carbonate precursors such as phosgene, haloformates, or carbonate esters. Generally, this aromatic polycarbonate has a repeating unit of the following structural formula.

-(-0-A-0-C+- In the formula, A is a divalent aromatic residue of dihydric phenol used in the above polymer production reaction. The aromatic polycarbonate used in the present invention has an intrinsic viscosity (chloride 2 in methylene
Measured at 5°C, unit dl/g) approximately 0.30 to 1.00
Preferably. The dihydric phenols used to form such aromatic polycarbonates are mononuclear or polynuclear aromatic compounds in which two hydroxyl groups are each bonded to a carbon atom of an aromatic nucleus as functional groups. Aromatic polycarbonates derived from bisphenol A and phosgene are commonly used.

The resin composition of the present invention can be made by mixing the above components in any order by a conventional method. For example, dry mixing so that all of the above components are well dispersed. moreover,
It is extruded into strands using a conventional method and then cut into pellets. These pellets can be used as a raw material to be molded into a desired shape by a conventionally known method. Such molded articles are also included in the present invention.

The resin composition of the present invention may further include conventional additives such as fillers, reinforcing agents, pigments, dyes, antioxidants, heat stabilizers, UV stabilizers, mold release agents, and the like.

Further, conventionally used phosphorus-based and halogen-based flame retardants can also be included.

The present invention will be further explained below with reference to Examples.

Examples Aromatic polycarbonate resin (PC) was Lexan (trademark, General Electric Company), intrinsic viscosity: value measured at 25°C in methylene chloride was 0.
．． 55 to 0.57) was used.

Potassium diphenylsulfonesulfonate (PDPhS) was used as the sulfonic acid metal salt.

As an alkylene glycol oligomer, the average molecule 1e
oo's polyethylene glycol oligomer PEG
(600) was used. Also, for comparison, the average molecule ff1
3.400 polyethylene glycol oligomer PE
G (3,400) was used.

The amounts of each component shown in Table 1 (heavy box) were sufficiently stirred and mixed at room temperature and extruded using a 65 mm + single screw extruder at a set temperature of 260° C. to produce pellets with a length of about 3 cm. Using this pellet, materials for each test described below were made.

Flame retardancy was measured on a 1/8" thick sample in accordance with UL94, and the flame retardancy level was determined.

The impact fracture resistance of a molded article made from a polycarbonate resin composition has dimensions of 63.5% x 12.7s x 3.
Regarding the rod-shaped molded test sample of 2 tri (thickness),
Izot impact strength was measured at room temperature according to ASTHD256 "Notched Izot Impact Test".

Moreover, KI (Kasha index) was measured as follows. Polycarbonate resin composition pellets h (125°C
``C@Low 90 minutes dry>7g improved Tinius-A Lucene (Tinius-01scn) T 3 Mel 1
~Fill into an index measuring device, maintain the temperature of the measuring device at 300'C, and heat the pellets at this humidity for 6 or 12 minutes. After 6 minutes or 12 minutes have elapsed, the pellet is removed using a plunger with a radius of 4.7371 m and a radius of 1.0478 m with a pushing force of 8.04 kg.
Forced discharge from the orifice on the surface. At this time, the time required for the plunger to move 50.8 m was measured in wrench seconds, and the value was set as KI in Table 1. The higher the KI, the higher the melt viscosity. Also, 6
The difference between Kl after heating for 1 minute and Kl after heating for 12 minutes can also be considered as a measure of the degree of thermal decomposition.

In the example, the transmittance (T%) of a molded product with a thickness of 3# is
Measurements were made using a spectrophotometer H-307 manufactured by Hitachi. In addition, the haze (H%), which is the value obtained by dividing the dispersed light beam by the total transmitted light beam, was measured using a haze meter M D manufactured by Nippon Heavy Industries.
I-1-1001D Determined using I-1. These results are shown in Table 1.

In Table 1, in Comparative Example 1 which does not contain any additives,
The UL94 flame retardant rating is v2.

In Comparative Example 2 and Examples, diphenylsulfonesulfonic acid potassium salt (P D Ph S ) was added. In Comparative Example 2, the flame retardant grade was not improved at all at V2 due to the small amount of PDPhS added;
In Example 1 in which E G (600) was added, the VO was greatly improved.

Compared to Comparative Example 1, no decrease in T and H is observed in the example. In other words, it has become possible to significantly improve flame retardancy while completely maintaining the original transparency of polycarbonate resin.

Furthermore, as typified by the notched isot impact strength of the examples of the present invention, the inherent mechanical strength of the polycarbonate resin is not impaired at all.

Further, since Kl hardly changes between 6 minutes and 12 minutes, it can be seen that thermal stability is not impaired as well. On the other hand, in Comparative Example 3, P
EG (3400) was added. That is, the addition of potassium diphenylsulfonesulfonate and PEG was the same as in the example, but the average molecular weight (C) was changed to 3,400. As a result, flame retardancy, mechanical strength, and melt thermal stability are
Although it was almost the same as the example, the haze 1 was significantly reduced.

As is clear from the examples, the polycarbonate resin composition according to the present invention has improved mechanical strength and processing properties by adding a small amount of PEG with a molecular weight of 14,300 to i,ooo together with a small amount of sulfonic acid metal salt. Flame retardancy is significantly improved while maintaining the important characteristics inherent to polycarbonate resins, such as thermal stability and transparency.

Although preferred embodiments have been shown here, the present invention is not limited to these embodiments.

Claims (1)

[Scope of Claims] 1,100 parts by weight of aromatic polycarbonate resin, 0.01 to 2.0 parts by weight of unsubstituted or substituted aromatic sulfonic acid metal salt or metal perfluoroalkyl sulfonate, and molecular weight A polycarbonate resin composition, characterized in that it contains 0.01 to 3.0 parts by weight of 200 to 1,000 alkylene glycol oligomers. 2. The polycarbonate resin composition according to claim 1, wherein the aromatic sulfonic acid metal salt is sodium diphenylsulfonesulfonate or potassium diphenylsulfonesulfonate.