DE4341459A1 - Thermoplastic moulding compositions comprising polyalkylene terephthalate and thermoplastic polyurethane - Google Patents

Abstract

Thermoplastic moulding compositions comprising A) from 65 to 99% by weight of polyalkylene terephthalate and B) from 1 to 35% by weight of thermoplastic polyurethane.

Description

The invention relates to thermoplastic molding compositions made from polyalkylene terephthalate and thermoplastic polyurethane and from these thermoplastic Molding compositions that can be produced and used, are very easy-flowing moldings.

DE-OS 41 13 891 and EP-A 334 186 describe molding compositions thermoplastic polyurethane and u. a. Polyalkylene terephthalates, the The proportion of polyurethane predominates.

U.S. Patent 4,169,479 describes thermoplastic polyurethane elastomer blends from 40 to 100% of a thermoplastic polyurethane, 0 to 60% of a thermo plastic polymers (polycarbonate) and 0.5 to 10% of an acrylic polymer. The Products are characterized by a good homogeneity of the mixture and the Moldings characterized by an improved gloss.

Mixtures of are known from US Pat. No. 4,350,799 and EP-A 0 074 594 thermoplastic polyurethanes, thermoplastic polyphosphonates and thermoplastic polycarbonates known, which is an improved Possess flame retardancy.

The object of the present invention is to provide a thermoplastic molding composition Based on polyalkylene terephthalates and thermoplastic polyurethane produce that is easy flowing and from the molded body with tough elastic Properties can be produced.  

The present invention relates to thermoplastic molding compositions

A: 65 to 99, preferably 70 to 98, in particular 75 to 98% by weight of polyalkylene terephthalates and
B: 1 to 35, preferably 2 to 30, in particular 2 to 25% by weight of thermoplastic polyurethane.

The mixtures according to the invention are notable for good flowability, Toughness, elasticity, hydrolysis stability and temperature resistance as well as Che resistance to chemicals. The molding compositions according to the invention are white ter due to an unexpected good compatibility of the mixing partners Polyalkylene terephthalate with thermoplastic polyurethane.

The thermoplastic molding compositions have a special extrusion material Meaning z. B. as an insulating material for the cable industry.

Furthermore, the molding compositions can be produced by injection molding Shaped body, especially for components from the electrical sector, z. B. as Butt edge for vacuum cleaner housings, in telecommunications or in the Automotive industry.  

Component A

Polyalkylene terephthalates in the sense of the invention are reaction products from aromatic dicarboxylic acids or their reactive derivatives (e.g. Dimethyl esters or anhydrides) and aliphatic, cycloaliphatic or araliphatic diols and mixtures of these reaction products.

Preferred polyalkylene terephthalates can be derived from terephthalic acid (or its reactive derivatives) and aliphatic or cycloaliphatic diols with 2 Manufacture up to 10 carbon atoms using known methods (Kunststoff-Handbuch, Vol. VIII, p. 695 ff, Karl-Hanser-Verlag, Munich 1973).

Preferred polyalkylene terephthalates contain at least 80, preferably 90 mol%, based on the dicarboxylic acid component, terephthalic acid residues and at least 80, preferably at least 90 mol%, based on the diol composition nente, ethylene glycol and / or 1,4-butanediol residues.

The preferred polyalkylene terephthalates can, in addition to terephthalic acid residues 20 mol% of residues of other aromatic dicarboxylic acids with 8 to 14 carbon atoms or contain aliphatic dicarboxylic acids with 4 to 12 carbon atoms, such as residues of Phthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, 4,4'-diphenyldicar bonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, cyclohexanediacetic acid.

In addition to ethylene or butanediol, the preferred polyalkylene terephthalates can 1,4-glycol residues up to 20 mol% of other aliphatic diols with 3 to 12 C- Contain atoms or cycloaliphatic diols with 6 to 21 carbon atoms, for. B. Leftovers 1,3-propanediol, 2-1,3-propanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexane-dimethanol, 3-methyipentanediol-2,4- 2- Methyl-pentanediol-2,4, 2,2,4-trimethylpentanediol-1,3 and -1,6,2-ethylhexanediol-1,3, 2,2-diethylpropanediol-1,3, hexanediol-2,5, 1,4-di- (β-hydroxyethoxy) benzene, 2,2- Bis (4-hydroxycyclohexyl) propane, 2,4-dihydroxy-1,1,3,3-tetramethyl-cyclobutane, 2,2-bis (3-β-hydroxyethoxyphenyl) propane and 2,2-bis (4-hydroxypropoxyphenyl) - propane (DE-OS 24 07 674, 24 07 776, 27 15 932).  

The polyalkylene terephthalates can be 3- or by incorporating relatively small amounts 4-valent alcohols or 3- or 4-basic carboxylic acid, such as z. B. in DE OS 19 00 270 and U.S. Patent 3,692,744 are described. Examples of preferred branching agents are trimesic acid, trimellitic acid, Trimethylolethane and propane and pentaerythritol.

It is advisable to use no more than 1 mole% of the branching agent, based on the Acid component to use.

Polyalkylene terephthalates which consist solely of terephthalic acid are particularly preferred and their reactive derivatives (e.g. their dialkyl esters) and ethylene glycol and / or 1,4-butanediol (polyethylene and polybutylene terephthalate), and mixtures of these polyalkylene terephthalates.

Preferred polyalkylene terephthalates are also copolyesters which consist of at least two of the above acid components and / or from at least two of the above alcohol components have been produced, especially preferred copolyesters are poly (ethylene glycol / 1,4-butanediol) terephthalates.

The polyalkylene terephthalates preferably used as component A generally a melt viscosity of about 300 to 1000 Pas, preferably 350 to 900 Pas, measured according to Göttfert.

A part of the polyalkylene terephthalate component can be replaced by aromatic poly carbonate to be replaced. The addition of replenished according to the invention worked components of the thermoplastic molding compositions is possible without the properties mentioned disadvantageously change.  

Component B

Thermoplastic polyurethanes according to component B of the present invention Reaction products from diisocyanates, wholly or predominantly aliphatic oligo- and / or polyesters and / or ethers, and one or more chains extend. These thermoplastic polyurethanes are essentially linear and have thermoplastic processing characteristics.

The thermoplastic polyurethanes are either known or can known methods (see, for example, U.S. Patent 3,214,411, J.H. Saunders and K.C. Frisch, "Polyurethanes, Chemistry and Technology", Vol. II, pages 299 to 451, Interscience Publishers, New York, 1964 and Mobay Chemical Coporation, "A Processing Handbook for Texin Urethane Elastoplastic Materials", Pittsburgh, PA) can be produced.

Starting materials for the production of oligoester and polyester are examples wise adipic acid, succinic acid, subecic acid, sebacic acid, oxalic acid, Methyl adipic acid, glutaric acid, pimelic acid, azelaic acid, phthalic acid, Terephthalic acid and isophthalic acid.

Adipic acid is preferred here.

As glycols for the production of the oligoesters and polyesters are, for example Ethylene glycol, 1,2- and 1,3-propylene glycol, 1,2-, 1,3-, 1,4-, 2,3-, 2,4-butanediol, Hexanediol, bishydroxymethylcyciohexane, diethylene glycol and 2,2-dimethyl propylene glycol into consideration. In addition, together with the glycols small amounts, up to 1 mol%, tri- or higher functional alcohols, e.g. B. Trimethylolpropane, glycerin, hexanetriol, etc. can be used.

The resulting hydroxyl oligo- or polyesters have a molecular weight of at least 600, a hydroxyl number of about 25 to 190, preferably about 40 up to 150, an acid number of approx. 0.5 to 2 and a water content of approx. 0.01 to 0.2%.  

Oligoesters or polyesters are also oligomeric or polymeric lactones, as in for example oligo-caprolactone or poly-caprolactone, and aliphatic Polycarbonates, such as poly-butanediol (1,4) carbonate or poly hexanediol (1,6) carbonate.

A particularly suitable oligo residue that is used as a starting material for thermo Plastic Polyurethane can be used is made from adipic acid and a Glycol produced, which has at least one primary hydroxyl group. The Condensation is ended when an acid number of 10, preferably about 0.5 to 2 is reached. The water that forms during the reaction becomes separated at the same time or afterwards, so that the water content in the end Range is about 0.01 to 0.05%, preferably 0.01 to 0.02%.

Oligo- or polyethers for the production of thermoplastic polyurethanes according to Component B are, for example, those based on tetramethylene glycol, Propylene glycol and ethylene glycol.

Polyacetals are also to be understood and used as polyethers.

The oligoethers or polyethers should have an average molecular weight n (number average, determined from the OH number of the products) from 600 to 2000, preferably from Have 1000 to 2000.

The organic diisocyanate used for the production of the polyurethanes Component B preferably used 4,4'-diphenylmethane diisocyanate. It should less than 5% of 2,4'-diphenylmethane diisocyanate and less than 2% of the Contain dimers of diphenylmethane diisocyanate. It is still desirable that the acidity, calculated as HCl, be in the range of about 0.005 to 0.2%. The acidity, calculated as HCl, is determined by extracting the chloride from the isocyanate in hot, aqueous methanol solution or by release of the chloride in hydrolysis with water and titration of the extract with standard Silver nitrate solution determined to the chloride ion contained therein tration to get.  

Other diisocyanates can also be used to prepare the thermoplastic poly Component B urethanes are used, for example the diisocyanates of ethylene, ethylidene, propylene, butylene, cyclopentylene-1,3, cyclohexylene- 1,4, cyclohexylene-1,2, 2,4-tolylene, 2,6-tolylene, p-phenylene, des n-phenylene, xylene, 1,4-naphthylene, 1,5-naphthylene, 4,4'-di phenylene, the 2,2-diphenylpropane-4,4'-diisocyanate, the azobenzene-4,4'-diiso cyanate, the diphenyl sulfone 4,4'-diisocyanate, the dichlorohexane methylene diisocyanate, the pentamethylene diisocyanate, the hexamethylene diisocyanate, the 1- Chlorobenzene-2,4-diisocyanate, furfuryl diisocyanate, dicyclohexylmethane diisocyanate, the isophorone diisocyanate, the diphenylmethane diisocyanate and Bis (isocyanatophenyl) ether of ethylene glycol, butanediol, etc.

Organic difunctional compounds can be used as chain extenders are the active, reactive with isocyanates, contain hydrogen, for. B. diols, Hydroxycarboxylic acids, dicarboxylic acids, diamines and alkanolamines and water. Examples include ethylene, propylene, butylene glycol, 1,4-butanediol, Butanediol, butynediol, xylylene glycol, amylene glycol, 1,4-phenylene-bis-β-hydroxy ethyl ether, 1,3-phenylene-bis-β-hydroxyethyl ether, bis (hydroxymethyl-cyclohexane), Hexanediol, adipic acid, ω-hydroxycaproic acid, thiodiglycol, ethylenediamine, Propylene, butylene, hexamethylene, cyclohexylene, phenylene, toluene, xylylene diamine, diaminodicyclohexylmethane, isophoronediamine, 3,3'-dichlorobenzidine, 3,3'- Dinitrobenzidine, ethanolamine, aminopropyl alcohol, 2,2-dimethyl-propanolamine, To name 3-aminocyclohexyl alcohol and p-aminobenzyl alcohol. The Molar ratio of oligo- or polyester to bifunctional chain extenders moved ranges from 1.1 to 1.50, preferably 1.2 to 1.30.

In addition to difunctional chain extenders, minor quantities can also be used up to about 5 mol%, based on moles of bifunctional chain ver longer, trifunctional or more than trifunctional chain extenders used become.

Such trifunctional or more than trifunctional chain extenders are for example glycerin, trimethylolpropane, hexanetriol, pentaerythritol and trietha nolamin.  

Monofunctional components, for example butanol, can also be used position of the thermoplastic polyurethanes used according to component B. become.

The diisocyanates mentioned as building blocks for the thermoplastic polyurethanes, Oligoester, polyester, polyether, chain extender and monofunctional com Components are either known from the literature or according to processes known from the literature available.

The known production of the polyurethane component B can, for example, how follows):

For example, the oligo- or polyester, the organic diisocyanates and the chain extenders preferably by themselves to a temperature of approx. 50 heated to 220 ° C and then mixed. Preferably the oligo or polyester first heated individually, then mixed with the chain extenders and mixing the resulting mixture with the preheated isocyanate.

The starting components can be mixed to produce the polyurethanes done with any mechanical stirrer that mixes intensely within allowed for a short time. If the viscosity of the mixture while stirring Should rise prematurely too quickly, the temperature can either be lowered or a small amount (0.001 to 0.05% by weight based on ester) of citric acid or the like may be added to decrease the speed of the reaction. Suitable catalysts, such as e.g. B. tertiary amines, which are mentioned in U.S. Patent 2,729,618, for Application come.

The molding compositions can contain nucleating agents such as microtalk. Farther the molding compounds can contain conventional additives such as lubricants and mold release agents, Processing stabilizers, fillers and reinforcing materials as well as dyes and Pigments included.  

The nucleating agents and usual additives except fillers and Reinforcing materials can be in amounts of about 0.1 to 3 parts by weight, based on 100 parts by weight of thermoplastic molding composition, from A + B + C are added.

Fillers and reinforcing materials can be used in quantities of 1 to 60 parts by weight, based on 100 parts by weight of A + B + C are added.

The molding compositions according to the invention can be prepared in the customary manner Mixing units such as rollers, kneaders, single or multi-shaft extruders Mixing of the individual components can be obtained.  

Examples

The components specified in the examples are mixed and mixed in one Injection molding machine under normal PBT processing conditions (melt temperature approx. 260 ° C) processed into test specimens.

Example 1 (comparison)

100.0% by weight of polybutylene terephthalate (PBT), melt viscosity 850 +/- 50 Pa · s (Göttfert) (relative solution viscosity 1.834 to 1.875, measured in a 0.5% solution of phenol and Dichlorophenol, mixing ratio 1: 1 parts by weight)

Example 2

97.0% by weight of polybutylene terephthalate (PBT), melt viscosity 850 +/- 50 Pa · s (Göttfert)
3.0% by weight of thermoplastic polyurethane, Desmopan® 385, Bayer AG (reaction product of an adipic acid-butanediol polyester with 4,4′-diphenylmethane diisocyanate, 1,4-butanediol as chain extender, saponification number <250)

Example 3

80.0% by weight polybutylene terephthalate (PBT), melt viscosity 850 +/- 50 Pa · s (Göttfert)
20.0% by weight of thermoplastic polyurethane, Desmopan® 385, Bayer AG (reaction product of an adipic acid-butanediol polyester with 4,4′-diphenylmethane diisocyanate, 1,4-butanediol as chain extender, saponification number <250)

Example 4

70.0% by weight of polybutylene terephthalate (PBT), melt viscosity 850 +/- 50 Pa · s (Göttfert)
30.0% by weight of thermoplastic polyurethane, Desmopan® 385, Bayer AG (reaction product of an adipic acid-butanediol polyester with 4,4′-diphenylmethane diisocyanate, 1,4-butanediol as chain extender, saponification number <250)

Table 1

Test results

Table 2

Composition of the molding compounds

Component 1 = polybutylene terephthalate with a relative solution viscosity of 1.855 measured in a 0.5% solution of phenol and dichlorophenol (mixing ratio 1: 1 parts by weight). ("Pocan B 1800", commercial product from BAYER AG)
Component 2 = thermoplastic polyester urethane with a saponification number <250, reaction product of an adipic acid-butanediol polyester with 4,4′-diphenylmethane diisocyanate, 1,4-butanediol as chain extender ("Desmopan 385", commercial product of BAYER AG)

The molding compositions according to the invention were produced on a ZSK 32 Melt temperatures of 260 to 300 ° C by adding component 1 with the component 2 was mixed and melted together. The strand was through a Spun water bath and granulated. The granules were dried at 120 ° C and to 50% proportional tension rods according to DIN 53457 (thickness 1.5 mm) Heated 260 ° C (mold temperature 80 ° C). The tension rods were before and after Storage in water at 100 ° C tested in tensile test according to DIN 53455.

Table 3

Test results

The test results from the tensile test show that the addition of small quantities component 2 brings about a significant improvement in the elongation at break values, which even after 6 days of water storage while maintaining the good tear strength is higher than that of the comparison material.

Claims (5)

1. Thermoplastic molding compounds

• A) 65 to 99 wt .-% polyalkylene terephthalate, and
• B) 1 to 35 wt .-% thermoplastic polyurethane.

2. Molding composition according to claim 1, wherein component

• A) is polybutylene terephthalate or polyethylene terephthalate or mixtures thereof,
• B) Component B are reaction products of diisocyanates and oligo- and / or polyester and / or polyethers with chain extenders.

3. Molding composition according to claim 1, characterized in that it Nucleating agents, lubricants, mold release agents, stabilizers, dyes, Contain pigments and / or fillers and reinforcing materials. 4. Use of the molding compositions according to claim 1, for the production of Molded articles. 5. Molded articles produced from molding compositions according to claim 1.