DE3841022A1 - Moulding compositions comprising arylene sulphide polymers and phenolic compounds - Google Patents

Abstract

The invention relates to moulding compositions obtained by melting arylene sulphide polymers (PAS), preferably polyphenylene sulphide (PPS), together with phenolic compounds. The moulding compositions have very good processing properties.

Description

The invention relates to molding compositions obtained by melting together of arylene sulfide polymers (PAS), preferably Polyphenylene sulfide (PPS), with phenolic Links. The molding compounds have very good processability.

Arylene sulfide polymers are known. (e.g. US-PS 33 54 129, EP-OS 1 71 021). They are considered inert, high temperature resistant Themoplastics, which also have a high degree of filling with glass fibers and / or other materials, increasingly for the electrical industry and other industrial sectors Interesting.

The use of these polymers, especially polyparaphenylene sulfide (PPS), mainly takes place in areas that Until now, thermosets were reserved because of the simpler ones Processability too.  

Injection-molded PPS molding compounds, which are usually glass fibers and / or mineral fillers in high concentrations included, are characterized by relatively low Viscosities of the melts. Your processing injection molding usually does not cause any problems.

When manufacturing thin-walled or very complicated Moldings can, however, cause difficulties if the flow paths of the melts in the mold are very long. This is preferably the case if for reasons the draft is laid so that a preferred orientation of the glass fibers results.

It can be difficult to manufacture such molded parts be the shapes despite the low viscosity of the Melt fill completely. The reason for this is, that PPS melting when cooling (approx. in the range around 230 crystallize up to 250 ° C). This can result in that with long flow paths of the melts, these already exist during the mold filling process up to this temperature range can be cooled, so that already solidification with increasing viscosity of the melt starts. The result is that the complete filling the shape is difficult. Generally, molded parts in their manufacture the solidification process of Melt sets in before the mold is completely filled is, reduced mechanical strength and - with reinforced or filled molding compounds - surface defects in the distance from the sprue.  

It would therefore be advantageous to reduce the melt viscosity of the To significantly reduce PAS, especially PPS.

The ability to lower the molecular weight accordingly is of little attractiveness because decreasing molar mass the mechanical property values sink.

In addition, low molecular weight arylene sulfide polymers can only be produced in a complex, electrolyte-free manner. Electrolyte-free Polymers are for applications in the field of Electrical industry an advantage.

EP-OS 94 092 uses phenolic Additives to stabilize PPS, especially against Gelation during processing, known. It will sterically hindered phenols, as usually also are used to stabilize other polymers, used.

In EP-A 70 010 phenolic resins are used for stabilization purposes possibly appropriately labeled, however their thermal stability is a priori too low judged. So there is a technical prejudice here in front.

It has now been found that mixtures of arylene sulfide polymers, preferably polyphenylene sulfide, and special phenolic compounds a significantly reduced Have melt viscosity, the crystallization rate,  depending on the additive, reduced or can be increased. The high crystallinity of the PPS is surprisingly i. a. almost unchanged or related even increased on the PPS share.

The invention therefore relates to arylene sulfide polymer Molding compounds made by melting together

• A) 70 to 99.9% by weight, preferably 80 to 99.5% by weight, particularly preferably 90 to 99% by weight Polyarylene sulfide, preferably polyphenylene sulfide and
• B) 0.1 to 30% by weight, preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight of phenolic compounds of the formulas (I) - (III) in which
  R independently of one another are hydrogen (H), halogen, preferably chlorine or bromine, C₁-C₂₀- (ar) alkyl, C₆-C₁₈- (alk) aryl, the (Ar) alkyl or (alk) aryl radicals being substituted, e.g. B. with halogen or -OH, or about z. B. -O- can be linked to the core,
  R¹ independently of one another a chemical bond, a C₁-C₂₀ alkylene or alkylidene radical, optionally substituted by halogen or -OH, an ester, an amide group, -O-, -SO -, - SO₂-, -S-, - CO-, or annealing two or more rings,
  R² is hydrogen or C₁-C₉ alkyl,
  n for the number 1, 2 or 3, preferably 1 and 2,
  m for the number 0, 1, 2, 3 or 4, preferably 1, 2 or 3,
  p 1 or 2,
  r for the number 0, 1 or 2, preferably 1,
  s for the number 0, 1 or 2, preferably 0 or 1,
  t is an integer from 0-8 (mean),
  l for the number 0, 1 or 2, preferably 0,
  k for the number 1 or 2, preferably 1 and
  X is an integer in the range from approximately 50 to approximately 500, which may contain up to approximately 50 mol% of comonomers,
  mean, with the proviso that preferably no radical which is in the o-position to an -OH group is a t-butyl group, and
• C) optionally 0.01 to 250 wt .-%, based on the weight of the sum of components A + B, other additives.

Examples of compounds of the formula (I) are 4-nonylphenol, 4-dedecylphenol, styrenated phenols, etc.

Examples of compounds of the formula (II) are alkylidene bisphenols how 2,2- (bis-4-hydroxyphenyl) propane (Bisphenol A), bis-4-hydroxyphenylmethane (bisphenol F) 1,1- (bis-4-hydroxyphenyl) cyclohexane (bisphenol Z), 1,1- (bis-4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2- Bis-4-hydroxy-3,5-dimethylphenyl) propane, 2,2- (bis-4-  hydroxy-3,5-dichlorophenyl) propane, 2,2- (bis-4-hy droxy-3,5-dibromophenyl) propane, phenol or alkyl phenol-formaldehyde condensates (novolaks) with on average preferably 3-8 rings per molecule etc.

Examples of additives of the formula (III) are preferred Vinylphenol- or Isopropenylphenol -Homo- or Copolymers.

Preferred additives are those of the general Formula (II) and (III), of which alkylidene bisphenols, Novolaks and polyvinylphenols are special are preferred.

The phenolic mixture components B can individually or used in a mixture. Mixtures of isomers can also be used or raw reaction products used will.

The phenolic mixture components B are in principle known or can by known methods getting produced.

The mixtures according to the invention are produced in the melt. You can after all in the Thermoplastic processing for blending usual processes (e.g. on kneaders or (worm shaft) extruders be carried out. It will be at a temperature from 290 to 400 ° C, preferably 300 to 350 ° C, executed.

The mixtures according to the invention can be used as a component C further additives such as fillers and reinforcing materials,  e.g. B. glass fibers, mineral fillers, Nucleating agents, plasticizers, flow aids, UV stabilizers, Antioxidants, pigments and other additives contain. Depending on the type of additive, 0.01 to 250 wt .-%, based on the sum of Weight of components A + B, other additives be used.

The mixtures according to the invention are notable for a reduced melt viscosity. In addition can the rate of crystallization also decreased or be elevated. Reduced crystallization rates can e.g. B. complicated for injection molding Molded parts (mold filling, surface quality), increased Crystallization rates for degradation of cycle times may be of interest. The disproportionate high crystallinity still leaves for the modified Arylene sulfide polymers have good mechanical properties expect. The mixtures according to the invention are suitable for the production of moldings, foils and Fibers, for injection molding and extrusion.

The melt viscosity measurements were made with a Contraves RM 30 plate-cone viscometer, the DSC measurements with a Perkin-Elmer DSC System 7 device carried out.

As a measure of the rate of crystallization the maximum of the crystallization exotherms on cooling from the melt (dynamic crystallization) chosen.  

Examples 1-3

Tedur® (BAYER AG) was used as the PPS.

Mixtures of approx. 30 g PPS granules each with a melt viscosity of 38 Pa · s at 320 ° C and a shear rate of 100 s ^-1 and 5, 10 and 20% by weight bisphenol A at 320 ° C were placed in a round bottom flask heated and homogenized with stirring. All in all, the mixture was stirred for 30 minutes after the polymer had melted. The heating baths were then removed, the mixtures were cooled to room temperature and the samples were chopped.

The results of the DSC investigations as well as the Melt viscosity determinations are in Table 1 specified.

Examples 4-6

In the manner given for Examples 1-3 PPS with 5, 10 and 20 wt .-% bisphenol F (composition: 5.8% 2.2'-, 34.0% 2.4'- and 49.4% 4,4'-isomer, Rest (approx. 11%) probably higher condensation products) modified.

The results of the DSC examination and the melt viscosity determination are given in Table 1.  

Examples 7-9

In the manner described for Examples 1-3 PPS with 5, 10 and 20 wt .-% bisphenol F (Zu composition: 10.5% 2.2'-, 30.5% 2.4'- and 51.6% 4,4′-isomer, rest (approx. 7.4%) probably higher con modified).

The results of the DSC examination as well as the enamel Viscosity determinations are given in Table 1.

Comparative Example 1

In the manner given in Example 1, PPS granu melted lat, stirred for 30 min and then eats, after removing the heating bath, the polymer Cooled to room temperature and chopped. The results the DSC examination and the melt viscosity assessment mood are given in the table.

In Tables 1 and 2, T _{S is} the melting point of the PPS and T _{K is} the crystallization temperature, determined from the maximum of the exothermic heat flow when cooling, both determined with a heating or cooling rate of 20 K min ^-1 . SV means the melt viscosity of the mixture at a temperature of 320 ° C and a shear rate of 100 s ^-1 .

Table 1

Examples 10-12

In the manner given in Example 1, a 5, 10 and 10 wt .-% of a phenol-formaldehyde condensate (Novolak) (Vulkadur RB®, BAYER AG; average 5-5 cores per molecule) modified PPS. The melt viscosity values as well as the results of the DSC tests are given in Table 2.

In contrast to that reduced in EP-A 70 010, insufficient thermal stability of phenol Resins in PPS were found to be novolaks have very high thermal stability in PPS.  

This finding is shown in Table 3; the Ge weight loss of the z. B. with 5% Novolak (Ex. 10) modified PPS are hardly larger than that of the Ver same.

Examples 13-15

In the manner specified in Example 1, PPS was used 5, 10 and 20% by weight of a styrenated phenol (Vulkanox SP®, BAYER AG) modified. The melt vis cosmetic values as well as the results of the DSC sub searches are given in Table 2

Comparative Example 2

In the manner described in Example 1, PPS- Granules melted, stirred for 30 minutes and on closing, after removing the heating bath, the polymer cooled to room temperature and chopped. The results DSC examination and melt viscosity Determination of activity are given in the table.

Table 2

Table 3

Claims (3)

Mixtures made by melting together

• A) 70 to 99.9% by weight, preferably 80 to 99.5% by weight, particularly preferably 90 to 99% by weight, of polyarylene sulfide, preferably polyphenylene sulfide and
• B) 0.1 to 30% by weight, preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight of phenolic compounds of the formulas (I), (II) and (III) in which
  R independently of one another hydrogen (H), halo gene, preferably chlorine or bromine C₁-C₂₀- (Ar) - alkyl, C₆-C₁₈- (alk) aryl, the (Ar) alkyl or (alk) aryl radicals being substituted , e.g. B. with halogen or -OH, or about z. B. -O- can be linked to the core,
  R¹ is independently a chemical bond, a C₁-C₂₀ alkylene or alkylidene radical, optionally substituted by halogen or -OH, an ester or an amide group, -O-, -SO-, -SO₂-, -S- , -CO-, or annealing two or more rings,
  R₂ is hydrogen or C₁-C₉ alkyl,
  n for the number 1, 2 or 3, preferably 1 and 2,
  m for the number 0, 1, 2, 3 or 4, preferably 1, 2 or 3,
  p 1 or 2,
  r for the number 0, 1 or 2, preferably 1,
  s for the number 0, 1 or 2, preferably 0 or 1,
  t is an integer from 0-8 (mean),
  l for the number 0, 1 or 2, preferably 0,
  k for the number 1 or 2, preferably 1 and
  x is an integer in the range from approximately 50 to approximately 500, which may contain up to approximately 50 mol% of comonomers,
  mean, with the proviso that preferably no residue which is in the o-position to an -OH group is a t-butyl group, and
• C) optionally 0.01 to 250 wt .-%, based on the weight of the sum of components A + B, other additives.

2. Preparation of the mixture according to claim 1, characterized characterized that by mixing the com components in the melt and homogenization the usual Ver in thermoplastic processing drive are manufactured. 3. Use of mixtures according to claim 1 for Manufacture of shaped bodies.