DE3719631A1 - Thermoplastic moulding compositions based on polyaryl ether sulphones - Google Patents

Abstract

Thermoplastic moulding compositions containing A) 80-90% by weight of a polyaryl ether sulphone containing recurring units of the formula I <IMAGE> or ring-substituted C1-C6-alkyl, alkoxy, aryl or halogen derivatives thereof, B) 1-20% by weight of a polyaryl ether sulphone containing recurring units of the formula II <IMAGE> or ring-substituted C1-C6-alkyl or alkoxy, aryl or halogen derivatives thereof.

Description

The invention relates to thermoplastic molding compositions containing

• A) 80-99 wt .-% of a polyaryl ether sulfone with repeating units of the general formula I. or their nucleus-substituted C₁-C₆ alkyl, alkoxy, aryl or halogen derivatives,
• B) 1-20 wt .-% of a polyaryl ether sulfone with repeating units of the general formula II or their core-substituted C₁-C₆ alkyl or alkoxy, aryl or halogen derivatives.

The invention also relates to the use of such thermoplastic Molding compounds for the production of printed circuit boards and electrical Plug connections and molded articles obtainable from the molding compounds.

Polyaryl ether sulfones with the general structural unit

(often, as also referred to below, simply referred to as polysulfones) are characterized by a very low water absorption and thus a very good dimensional stability (of the molded parts made from it). The heat resistance, (which is often determined by the maximum continuous use temperature is described, however, for some applications, in particular in the case of printed circuit boards (printed circuit boards, also called PCB) are not sufficient.  

Polyaryl ether sulfones with the general structural unit

have better heat resistance than polysulfones but the water absorption is much higher. As a consequence, that molded parts made of polyether sulfones tend to swell and warp, what when used in electrical engineering and electronics (manufacturing of printed circuit boards for printed circuits) is undesirable.

EP-A 97 370 describes mixtures of 40-90% by weight of polyaryl ether sulfones of the general formula II and 10-60 wt .-% polyaryl ether sulfones of the general formula I described. These show an unsatisfactory Water absorption and are no longer transparent.

The invention was therefore based on the object of thermoplastic molding compositions with a balanced range of properties, d. H. a sufficient one Heat resistance with low water absorption and high To provide resistance to stress cracking that is required for the manufacture of printed circuit boards, in particular printed circuit boards (printed circuit boards) are suitable.

According to the invention, this object is achieved by the thermoplastic materials defined at the outset Molding compounds released.

Preferred molding compositions of this type are the dependent claims and the following detailed description.

Component A is polyaryl ether sulfone with recurring units of formula I.

or their nucleus-substituted C₁-C₆ alkyl, C₁-C₆ alkoxy, aryl (in particular Phenyl) and halogen derivatives. As examples of such Substituents are methyl-, ethyl-, i- and n-propyl as well as n-, i- and t-butyl groups and the corresponding alkoxy groups, phenyl or Naphthyl groups and chlorine or bromine called. Up to 20 mole% of the recurring Units in the polyaryl ether sulfones A can be replaced by recurring Units to be replaced that differ from other monomers deduce.  

Such monomers are, for example, dihydroxy compounds of the general type Formula III

in which

X is a chemical bond or a substituent of the type

(R₃ R₄ when R = CH₃) and
R₁, R₂, R₃ and R₄ represent hydrogen, alkyl or alkoxy groups with 1-6 C atoms, aryl groups or halogen-substituted alkyl groups with 1-4 C atoms, and
m is 0 or 1, preferably 1 and
n and p have the value 0, 1, 2, 3 or 4.

The following are some examples of such dihydroxy compounds listed.

As monomers that build up a maximum of 20 mol% repeating units the polyaryl ether sulfones A can continue to be involved To name dihalogen compounds of the general formula IV:

in which

Y: Cl or F

or represent a chemical bond.
R⁷, R⁸, R⁹ and R¹⁰ are hydrogen, Cl or F or can have the same meaning as R¹ and R²,
q and p have the value 0 or 1 and
r, s, t and u can be an integer from 0 to 4.

Z₂ is preferably a chemical bond,

and R⁷, R⁸, R⁹ and R¹⁰ are preferably hydrogen, methyl, ethyl or Cl or F.
r, s, t and u can each be 0, 1, 2, 3 or 4, preferably 0, 1 or 2.

Below are just a few examples of such Dihalogen compounds shown.

The production of polyaryl ether sulfones with repeating units of general formula I can according to known and in the literature described procedures take place. A preferred method variant is shown below described.

The dihydroxy compounds, i. H. Bisphenol A (2,2-di- (4-hydroxyphenyl) propane) or its core-substituted derivatives (Proportion of at least 80 mol%, based on the total amount Dihydroxy compounds) and any other available Dihydroxy compounds (max. 20 mol%, based on the total amount Dihydroxy compounds) in a molar ratio of 0.8: 1 to 1.2: 1, preferably 0.9: 1 to 1.1: 1, in particular 0.98: 1 to 1.02: 1 with 4,4-dihydroxydiphenyl sulfone (bisphenol S; minimum content 80 mol%, based on the total amount of dihalogen compounds) in Presence of 1.0 to 2.0 mol, preferably 1.05 to 1.5 mol, of one anhydrous alkali metal carbonate, especially K₂CO₃, in one aprotic polar solvent implemented.

Suitable aprotic polar solvents are N-substituted Acid amides and lactams preferred. For example, consider N, N-dimethylformamide, N, N-dimethylacetamide or N-methylpyrrolidone called.

If desired, an azeotroping agent can be removed from the solvent of the water of reaction are added. Such connections are in the Literature described. However, it can also be advantageous in the presence work with an azeotrope.

The amount of monomers based on the total amount of solvent is generally 20 to 80, preferably 30 to 70, in particular 40 up to 60% by weight.  

At temperatures in the range of 100 to 200, preferably 130 to 180 ° C. the majority of the water of reaction formed can be removed. This can e.g. B. alone thermally, by adding an azeotrope or preferably by applying a negative pressure.

The condensation can then be carried out at temperatures in the range from 180 to 220 ° C until reaching the desired molecular weight or the desired Degree of condensation to be continued.

The total reaction time is generally from 5 to 20, preferably from 7 to 15 h and is of course dependent on the reaction conditions (temperature and pressure) and depending on the desired molar mass of the product.

Following the polycondensation, free phenolate end groups can be used for stabilization with an aryl or alkylating agent, such as. B. methyl chloride, be implemented. This is preferably done at temperatures of 50 to 200, preferably 50 to 150 ° C.

The suspended alkali halide obtained in the polycondensation can with a suitable separation device, for example a clarifying filter or a centrifuge.

The polycondensates can be isolated from the solution by evaporating the Solvent or precipitation in a suitable non-solvent respectively.

Products made by the process described above generally a reduced viscosity in 1% by weight Phenol / o-dichlorobenzene (1: 1) solution at 25 ° C, from 0.35 to 3.0, preferably 0.45 to 1.0, in particular 0.45 to 0.85.

The proportion of polyaryl ether sulfones A) in the invention thermoplastic molding compositions is 80-99, preferably 85-99 and in particular 90-98% by weight, based on the total weight of components A) and B).

The polyaryl ether sulfones B) have recurring units of general formula II

or their nucleus-substituted C₁-C Alkyl alkyl, C₁-C₆ alkoxy, aryl or Halogen derivatives. With regard to preferred substituents, reference is made to the Reference made to component A) above.  

As in the case of the polyaryl ether sulfones A), up to 20 mol% recurring units may be present that differ from other monomers deduce. The same statements apply as in this Considerations for component A were made.

The polyaryl ether sulfones B) can be prepared according to known methods and procedures described in the literature. A is preferred Process as described for component A), instead of of bisphenol A only 4,4'-dihydroxydiphenyl sulfone or its core-substituted derivatives are used.

The proportion of component B is 1-20, preferably 1-15 and in particular 2-10 wt .-%, based on the sum of A + B).

In addition to components A and B, the molding compositions according to the invention can also reinforcing fillers, optionally transparent Pigments and other auxiliaries and additives are modified.

Examples of reinforcing fillers are asbestos, coal and preferably called glass fibers, the glass fibers e.g. B. in the form of Glass fabrics, mats, nonwovens and / or preferably glass silk rovings or cut glass silk from low-alkali E-glasses with a Diameters from 5 to 200 µm, preferably 8 to 15 µm, for use get that after their incorporation an average length of 0.05 to 1 mm, preferably 0.1 to 0.5 mm. The one with glass silk rovings or cut glass fiber reinforced molding compounds contain between 10 and 60% by weight, preferably 20 to 50% by weight, of the reinforcing agent, based on the total weight, while the impregnated glass fabrics, -mats and / or -vlies between 10 and 80 wt .-%, preferably between 30 and 60 wt .-% copolycondensates, based on the total weight. Suitable pigments are, for example, titanium dioxide, cadmium, Zinc sulfide, barium sulfate and carbon black. As other additives For example, dyes, lubricants, such as. B. Graphite or molybdenum disulfide, abrasives, such as. B. carborundum, light stabilizers and hydrolysis inhibitor. The pigments, additives and Auxiliaries are usually obtained in amounts of 0.01 to 3% by weight on the weight of polycondensates.

Also wollastonite, calcium carbonate, glass balls, quartz flour, Si and boron nitride or mixtures of these fillers can be used.

The thermoplastic molding compositions according to the invention are notable for their balanced properties. With a high heat resistance and good resistance to stress cracking, they show little Water absorption and are very easy to process.  

The molding compositions according to the invention can be used to produce moldings, Foils and fibers are used. They are particularly suitable because of their good properties for the production of printed circuit boards and electrical Connectors.

Examples Production of the polymers

The following were used to produce molding compositions according to the invention Components A and B used:

• A / 1 polyaryl ether sulfones with the general structural unit
• In a 300 l container with stirrer of N₂ connection were under Nitrogen atmosphere 86 kg N-methylpyrrolidone, 22.8 kg bisphenol A (50 mol), and 28.72 kg of 4,4-dichlorodiphenyl sulfone dissolved and with 15.2 kg of anhydrous potassium carbonate (150 mol) were added.
• The reaction mixture was under a pressure of 300 mbar (30 kPa) constant distillation of the water of reaction and N-methylpyrrolidone first heated to 180 ° C for 1 h and left at this temperature for 3 h. The reaction was then continued at 190 ° C. for 6 h.
• By adding methyl chloride at a temperature of 150 ° C and reaction for two hours under pressure (0.5 bar) Polycondensation canceled.
• After adding 125 kg of N-methylpyrrolidone, the inorganic Components filtered off and the polymer by precipitation in methanol isolated as a solid. After drying at 100 ° C in a vacuum Polymer made up in granules.
• A / 2 polysulfone with repeating units as for A / 1, but with one Weight average molecular weight of 30,000. The product was manufactured as described in A / 1. (Response time 4 instead of 6 h at 190 ° C.)  
• A / 3 copolymer of 80 mol% units of the general formula I
  20 mol% units of the general formula II
  (Production analogous to that described in A / 1)
  Weight average molecular weight: 40,000.
• Components B were prepared using an analogous procedure to that Component A / 1 prepared using the appropriate monomers were.
• B / 1 polyaryl ether sulfone with repeating units of the general formula (Weight average molecular weight = 40,000)
• B / 2 polyaryl ether sulfone with repeating units such as B / 1, but with a weight average molecular weight of Mw = 29,000.
• B / 3 polyaryl ether sulfone from repeating units (Weight average molecular weight = 42,000)
• B / 4 polyaryl ether sulfone from repeating units (Weight average molecular weight = 41,000)

To produce the polymer mixtures according to the invention, the Components mixed on a twin-screw extruder, extruded, granulated and dried.

To assess the transparency, round discs of 2 mm in thickness were used Injection molded.

The relationship between the mixtures and the measurement results are the See table 1.

Table 1

(all quantities in% by weight)

The results show that the molding compositions according to the invention are good Have transparency while outside the claimed area none transparent molding compositions can be obtained.

Claims (4)

1. Thermoplastic molding compositions containing

• A) 80-99 wt .-% of a polyaryl ether sulfone with repeating units of the general formula I. or their nucleus-substituted C₁-C₆ alkyl, alkoxy, aryl or halogen derivatives,
• B) 1-20 wt .-% of a polyaryl ether sulfone with repeating units of the general formula II or their core-substituted C₁-C₆ alkyl or alkoxy, aryl or halogen derivatives.

2. Thermoplastic molding compositions according to claim 1, characterized by the following contents:

• A) 90-98% by weight
• B) 2-10% by weight

3. Use of the thermoplastic molding compositions according to claims 1 and 2 for the production of printed circuit boards and electrical Connectors. 4. Moldings, obtainable from thermoplastic molding compositions according to the Claims 1 and 2 as essential components.