DE4224164A1 - Granules and moulded parts prodn., for use in e.g. vehicle construction - by thermoplastic processing of crosslinked polyurethane(s) or polyurea(s), e.g. by the RIM method, opt. with addn. of thermoplastics - Google Patents

Abstract

Prepn. of granulates and moulded prods. from (A) crosslinked isocyanate-based plastics, opt. mixed with (B) thermoplastics, with wt. ratio (A):(B) = (100:0)-(9.99:90.01) is new. (A) are polyurethanes, polyureas and/or polyurethane-ureas, with mean functionality at least 2.5 in the flexible segment and density at least 0.6 (pref. 0.6-1.1) without filler. (A) are prepd. from (a) polyisocyanates, (b) cpds. of mol. wt. 1800-12,000 contg. at least 2.5 NCO-reactive gps. (mean), opt. (c) ether gp.-contg. (cyclo)alkane-polyols and/or -polyamines with mol.wt. 60-1799 and opt. (d) diamines of mol. wt. 108-400 with 2 prim. and/or sec. aromatic amino gps., opt. with addn. of (e) known polyurethane additives etc.. The prepn. is carried out in one or more stages, with NCO index 60-140 and with total amt. of (c) and/or (d) = at least 5 wt.% w.r.t. (b). USE/ADVANTAGE - The prods. are used e.g. in vehicle construction, electrical and electronic prods., sports goods, domestic appliances etc.. The process enables the prodn. or recycling of crosslinked polyurethane (PU) materials in the form of homogeneous pellets, granules etc. (by extrusion) or mouldings (by direct injection moulding), without the disadvantages of prior-art processes (e.g. very high moulding pressures, addn. of at least 10% (B), expensive grinding operations if (A) is used as a filler).

Description

The present invention relates to a novel Ver drive to the production of molded parts in the networked Polyurethane-polyurea plastics, if necessary in a mixture with known thermoplastic materials, processed into molded parts.

The recycling of plastics has increased in recent years Years of very high priority. Also for chemically cross-linked polyurethane-polyureas, like them e.g. B. in highly stressed bumpers and fenders Have been used, they looked for ways send them to material recycling.

In this To the applicant has filed several applications is sufficient in which a material reuse wetted polyurethanes by so-called extrusion sen, z. B. in DE 37 33 756, 38 02 427, 38 09 524, 38 22 331 or 38 04 167.

Although this work compared to the previously known State of the art of a non-material recycling ability of the non-melting, thermosetting polyurethanes  went out, signify great progress, was the approach Applicability of the described methods in practice limited to the extent that for the production of large areas ger moldings very large pressing forces, as in the Usually not available (e.g. presses with 10,000 tons of pressing force) were required.

In continuation of this work, the applicant has further applications (DE-A-41 02 999 and DE-A-41 20 693) filed in which procedures are described with chemically cross-linked polyurethane-polyureas with the help of thermoplastics in the mixture, or with foamed polyurethanes, also alone, thermopla verically via injection molding and extrusion to molded articles can be worked. At massi ven, non-foamed, chemically cross-linked polyurethane Polyureas have the disadvantage that during processing a share of at least 10% of a thermoplastic must be added; this leads to the drain problems of waste prevention and recycling to an undesirable increase in waste.

The person skilled in the art also knows the possibility of Polyureas to grind very finely and this regrind as filler z. B. thermoplastics or also polyurethane polyurea formulations in their Processing to incorporate. With this method it can to a deterioration in the properties of the thermoplastic molded articles come. Therefore and because of the from Ver small amount to be used for reasons of work this method the pressing problem of polyurethane  Do not fully manage recycling. Still is because of the necessary high degree of fineness of the powder this type of waste recycling is still relatively complex.

It was therefore an object of the present invention To provide procedures in which the after parts of the prior art are avoided and State of the art in an advantageous manner is enriched.

Surprisingly, it has now been found that chemically cross-linked polyurethanes, polyurethane-poly urine substances and polyureas (hereinafter generally referred to as Designated polyurethane) under the influence of shear forces and warmth, to macroscopically homogeneous articles in conventional thermoplastic processing machines let walk; if necessary, you can also do this minor proportions of thermoplastics added become.

The present invention therefore relates to a ver drive for the production of granules, semi-finished products and Molded parts made of (A) cross-linked plastics on Iso cyanate base, optionally mixed with (B) thermo plastic plastics, characterized in that as plastics based on isocyanate (A) polyurethane, Polyurea and / or polyurethane-urea art substances are used and where (A) and optionally (B) are in the weight ratio 100: 0-9.99: 90.01, where (A) medium functionality in the soft segment of <= 2.5 and where (A) has no fillers  Has density of <= 0.6, preferably 0.6-1.1 and where (A) has been made from

• a) organic polyisocyanates,
• b) compounds with a molecular weight of 1800 to 12000, which on average have at least 2.5 groups which are reactive toward isocyanates,
  possibly
• c) (Cyclo) alkane polyols and / or (cyclo) alkane polyamines having ether groups and having a molecular weight in the range from 60 to 1799,
  and if necessary
• d) diamines with two primary and / or secondary, aromatically bound amino groups of the molecular weight range 108-400,
  and possibly also with the use of
• e) those known per se from polyurethane chemistry Auxiliaries and additives,

while maintaining an isocyanate index of 60 to 140 have been produced in a single or multi-stage process with the proviso that at least one of the components c) and / or d) is used in such an amount, that the total amount of components c) and / or d)  at least 5% by weight based on the weight of the compo nente b), and preferably that c) always mitver is applied.

The present invention also relates to produced by the inventive method Granules, semi-finished products and molded articles.

The chemically crosslinked polyurethanes, polyureas and Polyurethane ureas (component A) are preferred processed according to the so-called RIM or RRIM technology. Here can according to the so-called. one-shot technique or Prepolymer technology. Instead of RIM technology can also be used e.g. B. uses the casting technology become.

Of course, chemically cross-linked here polyurethanes, polyurethane ureas and polyureas substances by extrusion or adhesive pressing, d. H. Pres sen with the help of org. Binders - as in DE-A-40 26 068 -, manufactured materials settable.

Suitable raw materials for the production of compo nente (A) are:

Component a

For the production of the polyisocyanate polyaddition products suitable isocyanates over 137, preferably at Excluding 168 to 290 lying molecular weight  Lich (cyclo) aliphatic isocyanate groups such as for example 1,6-diisocyanatohexane, 1,12-diisocyanato dodecane, 1,3-diisocyanatocyclobutane, 1,3- and 1,4-diiso cyanatocyclohexane, as well as any mixtures of this iso mer, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (IPDI), 2,4- and / or 4,4'-diisocyanatodi cyclohexylmethane or any mixtures of such multiple (cyclo) aliphatic polyisocyanates. Also are suitable by urethane, allophanate, isocyanurate, Modify urea, biuret and / or uretdione groups te polyisocyanates based on the examples mentioned (Cyclo) aliphatic diisocyanates or based on their mixtures, mixtures of unmodified diiso cyanates with the modified polyisocyanates mentioned can also be used as component a).

Suitable aromatic polyisocyanates are any aro Matic polyisocyanates with an NCO content of 10-50 % By weight.

Component b

Component b) is a compound with groups reactive towards isocyanate groups of the molecular weight range 1800 to 12,000, preferably as 3000 to 7000 or mixtures of such Ver bindings, component b) in the sense of Iso cyanate addition reaction over 2.5, preferably at 2.6 to 3.0 and particularly preferably 2.8 to 3.0, has horizontal (medium) functionality. Especially compounds which are well suited as component b),  corresponding polyether polyols or Mixtures of polyether polyols as in DE-AS 26 22 951, column 6, line 65, column 7, line 47, are disclosed, such poly ether polyols are preferred whose hydroxyl groups at least 50%, preferably at least 80% primary hydroxyl groups exist. Also in DE-AS 26 22 951 exemplified disclosed, hydroxyl groups pointing polyester, polythioether, polyacetal, poly In principle, carbonates or polyester amides are considered to be him Component b) according to the invention suitable, provided that they The statements made above correspond, but against less preferred over the polyether polyols.

Are also well suited as starting component b) corresponding statements above, aminopolyether or Mixtures of aminopolyethers, i.e. H. Polyether with against about isocyanate reactive groups, which are at least 50 equivalent%, preferably at least 80 equivalent% of primary and / or secondary, aromatic or aliphatic, preferably aromatic ge bound amino groups and the rest of primary and / or secondary, aliphatically bound hydroxyl groups assemble. Suitable amino polyethers of this type are for example that in EP-B-00 81 701, column 4, line 26 to column 5, line 40, compounds mentioned.

Also suitable as starting component b), however less preferred are amino groups poly esters of the above-mentioned molecular weight range.  

As component b) can of course also bige mixtures of the exemplified polyhydroxyl compounds with the exemplified aminopoly ether can be used.

Component c

In the case of the polyols to be used, if appropriate, or Polyamines are any non-aromatic connections with at least two compared to Iso cyanate groups reactive groups of the Molecular Ge weight range 18, 60 to 1799, preferably 62 to 500, especially 62 to 400. Consider for example such as polyhydric alcohols as described in EP-B-00 81 701, Column 9, lines 32 to 50 are disclosed; especially others are the following alcohols as components c) moves: EG, DEG, TEG, PG, DPG, TPG, butanediol, hexanediol. Also considered are, for example, ether groups aliphatic polyamines containing pen, for example terminal polypropylene having primary amino groups lenoxides of the mentioned molecular weight range. In Cycloaliphatic rings are also considered Polyols such as 1,4-dihydroxycyclohexane or 1,4-bis-hydroxymethyl-cyclohexane and polyamines as in for example 1,4-cyclohexane diamine, isophoronediamine, bis- (4-aminocyclohexyl) methane, bis (3-methyl-4-aminocyclo hexyl) methane. Polyols are ahead of polyamines moves.  

Component d

In the case where appropriate as further structural components d) the diamines to be used are aroma table diamines in EP-B-00 81 701, column 5, line 58 to column 6, line 34, of the type mentioned by way of example, according to the invention also being preferred there issued diamines are preferred. Overall is ever but the use of components d) less prefers.

It is an essential point in the manufacturing process the elastomers at least one of the components c) and / or d) is used, namely in such Amounts that the weight fraction of components c) and / or d), based on the weight of component b), at least 5% by weight, preferably at least 10% by weight is. However, the sole use is preferred component c).

In the case of the production of the polyisocyanate polyaddi if necessary, auxiliary products to be used and additives e) are, for example internal mold release agents, catalysts for polyiso cyanate polyaddition reaction, blowing agent, water, upper surface active additives, cell regulators, organic and inorganic pigments, dyes, UV and thermal stabilizers lisators, plasticizers or fungistatic or bacterio substances with a static effect, as described, for example, in EP-B-00 81 701, column 6, line 40 to column 9, line 31, are described by way of example.  

Regarding the auxiliaries and zu to be used if necessary Substitutes include the known fillers and / or Reinforcing materials such as barium sulfate, Diatomaceous earth, chalk, mica or, in particular, glass fibers, LC fibers, glass flakes, glass balls, aramid or Carbon fibers.

Other auxiliary and auxiliary elements that may also be used Substitute means e) are, for example, the usual catalysts catalysts for the polyisocyanate polyaddition reactions, surface-active additives, cell regulators, pigments, Dyes, flame retardants, stabilizers, soft maker or fungistatic or bacteriostatic Substances such as those described in EP-B-00 81 701, Column 6, line 40 to column 9, line 31 are examples are described, these filling and / or reinforcing Kungsstoffe in amounts of up to 80 wt .-%, preferably up to 30 wt .-%, based on the total weight of the ge filled or reinforced polyisocyanate polyaddition pro products can also be used.

The production of the polyisocyanate polyaddition products is preferably carried out according to the one-step process.

Where appropriate for the method according to the invention can be used with thermoplastic materials be any thermoplastic, e.g. B.

• Polyolefins such as polypropylene or polyethylene,
• impact-modified polyolefins such as PP / EPDM,  
• - Polyacrylates such as B. polymethacrylate, polystyrene or Styrene / acrylonitrile copolymers, acrylic acid modifi graced SAN,
• - Polycarbonates and their blends with e.g. B. aromatic Polyesters, block copolymers such as Si-Co-PC, DIM-PC, Polyether PC,
• - Polyesters such as polyethylene or polybutylene terephthalate lat,
• - Vinyl chloride resins such as - possibly softened - PVC or PVC / ABS blends,
• - linear thermoplastic polyurethanes of the known Kind,
• - Thermoplastic elastomers, such as. B. Copolyether esters, polyether block amides or blend systems of the type PP / NBR, PP / EPDM, HNBR / PBT, HNBR / PA, HNBR / POM, HNBR / SAN, HNBRISEA.

Also possible, but less so in the present case preferred is the use of - possibly modified ten or plasticized - polyimides, polysulfones, Polyether sulfones, aromatic polyarylates, polybenz thiazoles, aliphatic and / or aromatic poly amides, polyether ketones, polyphenylene sulfides etc.

The synthetic resins of component (B) can be used alone or in any physical mixture, as heterogeneous or homogeneous polymer systems, as blends or so-called poly mer alloys are present.

Component (A) and (B) can both be auxiliary and closed contain substitutes that according to the current status of  Technology for these plastics are common, especially Fillers and reinforcing materials such as z. B. Modifi adornment of mechanical properties, e.g. B. Impact resistant modification, increase in stiffness, for density reduction tion or discount are usually used.

For the production and processing of component (A) or optionally the mixtures of components (A) and (B) can usually the same mixing and Ver working machines are used as they are Specialist in the practice of thermoplastic processing since have long been known, e.g. B. roller extruder, single or Twin-shaft extruder, kneader, internal mixer, mixing rollers systems, calender systems, double belt presses and spraying casting machines.

When carrying out the method according to the invention can in addition other auxiliary materials and additives of the State of the art are used, in particular Fillers and reinforcing materials.

In the products obtained according to the invention, the Synthetic resins (A) and optionally (B) usually one at least macroscopically, or microscopically homogeneous phase.

The products of this process according to the invention can either in the form of semi-finished products (pellets, strands, granu lat, plates) are present (extrusion processing) or processed directly into molded articles (injection molding processing).  

As such, either directly or by spraying the Shaped articles available as semi-finished products are suitable for films, Films, fibers and any three-dimensional shape kel. Applications are conceivable. B. in motor vehicle, Electrical and electronics articles, toys and im Home appliance sector.

Process products according to the invention can e.g. B. in the form of small molded parts as keyboard elements, hard elastic sealing parts and sleeves, recessed grips and Handle body, small damping elements or underlay or Spacers are used, also as stiffened and unstiffened profiles for cable ducts and seals lips or any other massive little body be used.

The flat bodies are also suitable for Writing pads, bulletin boards with magnetic holders, Adhesive labels, protective films and coatings for the various purposes. Process pro Products can also be in the form of small molded parts such as Keyboard elements, hard elastic sealing parts and Cuffs, recessed grips and grip bodies, small Damping elements, washers and spacers Ver find application.

example 1 Production of the isocyanate-based plastic

Polyol component:
74.60 parts of a polyether with OH number 45, obtained by the blockwise addition of first 87% by weight of propylene oxide and then 13% by weight of ethylene oxide to propylene glycol,
25.4 parts of butanediol,
0.3 parts of Dabco 33 LV, an amine catalyst from Air Products,
0.2 parts UL 28, a tin catalyst from Witco.

100 parts of this polyol formulation with 117 Tei len (KZ 110) of a urethane-modified MDI of the NCO Content processed 24.5 wt .-%. The isocyanate will obtained by reacting a polypropylene glycol OH number 515 with an isocyanate mixture based on MDI 90 wt .-% 2-core portion, here 10% 2,4'-portion and 10% multinuclear shares, the NCO content 31 + 1%.

The polyol component listed above was at 45 ° C, the isocyanate component listed above to 40 ° C warms and according to the reaction injection molding principle (RIM Ver drive) on a 12 l Rimdomat from Hennecke, Birlinghoven, in a mold heated to 65 ° C (Plate shape of dimensions 380 × 200 × 3 mm) whose Inner walls coated with an external release agent  have been injected. The mold life was 30 s. The parts were annealed at 120 ° C for 45 min. After 14 days of storage at 20 ° C, the properties ten the molded body determined.

The polyurethane materials thus produced have (according to DIN 53 504) - before tempering - a tensile strength of 28.3 MPa and an elongation at break of 160%.

Method according to the invention

Granules made from this isocyanate-based plastic was produced, grain size approx. 2 mm to 3 mm, is in an injection molding machine type D 50, manufacturer: company Demag, Nuremberg, at a melt temperature of 240 ° C, in a cold tool (for the production of test specimens for tensile tests).

The on this, thermoplastic processed material material properties measured in accordance with DIN 53 504 in train ver are: tensile strength 28.1 MPa and elongation at break 35%.

Example 2 Production of the isocyanate-based plastic

Polyol component:
90.00 parts of a polyether mixture

• a) 45 parts of a polyether having an OH number of 27 are obtained by adding 75% by weight of propy in blocks first lenoxid and then 25 wt .-% ethylene oxide of trimethyl olpropan, and
• b) 45 parts of a polyether with OH number 56, herge represents by adding first 90 parts of a Ge mix from 40 parts of ethylene oxide and 50 parts of propy lenoxid and then 10 wt .-% ethylene oxide

23.5 parts of ethylene glycol
5 parts of black paste NR, consisting of 80% of a polyether having an OH number of 35 and 20% by weight of carbon black
0.3 parts of Dabco 33 LV, an amine catalyst from Air Products
0.2 parts UL 28, a tin catalyst from Witco.

100 parts of this polyol formulation are 131 Share (KZ 110) a urethane-modified MDI's NCO content 24.5 wt .-% and a viscosity of 500 ± 100 mPa · s (23 ° C), which can be achieved by implementing a Mixture of a) 90 parts of a mixture of 90% 4,4'- and 10% 2,4'-diisocyanatodiphenylmethane and b) 10% by weight of multi-core components, with polypropylene glycol the OH number 515 was obtained, processed.

The polyol component listed above was at 45 ° C, the isocyanate component listed above to 40 ° C warms and according to the reaction injection molding principle (RIM Ver drive) on a 12 l Rimdomat from Hennecke, Birlinghoven, in a mold heated to 65 ° C  (Plate shape of dimensions 380 × 200 × 3 mm) whose Inner walls coated with an external release agent have been injected. The mold life was 30 s. The parts were annealed at 120 ° C for 45 min. After 14 days of storage at 20 ° C, the properties ten the molded body determined.

The polyurethane materials thus produced have (according to DIN 53 504) - before tempering - a tensile strength of 36 MPa and an elongation at break of 170%.

Method according to the invention

Granules made from this plastic based on isocyanate was produced, grain size approx. 2 mm to 3 mm, is in an injection molding machine type D 50, manufacturer: company Demag, Nuremberg, at a melt temperature of 240 ° C, in a cold tool (for the production of test specimens for tensile tests).

The on this, thermoplastic processed material Material characteristics measured on the train according to DIN 53 504 try:

Tensile strength 22.4 MPa and elongation at break 15%.

Example 3 Production of the isocyanate-based plastic:

Polyol component:
83.30 parts of a polyether of OH number 28, obtained by blockwise addition of first 82.5% by weight of propylene oxide and then 17.5% by weight of ethylene oxide to trimethyolpropane,
12.5 parts of a mixture of 65 parts of 1-methyl-3,5-diethyl-2,4-diamino-benzene and 35 parts of 1-methyl-3,5-diethyl-2,6-diamino-benzene
4 parts of black paste N
0.1 part Dabco 33 LV, an amine catalyst from Air Products
0.1 parts UL 28, a tin catalyst from Witco.

100 parts of this polyol formulation are 36 parts (KZ 110) of a urethane-modified MDI of the NCO-Gehal tes 23.0% by weight and a viscosity of 700 ± 150 mPa · s (23 ° C), which by reaction of 4,4'-diphenylmethane diisocyanate was obtained with tripropylene glycol, ver is working.

The polyol compo listed above was used for processing nente to 45 ° C, the isocyanate component listed above heated to 40 ° C and according to the reaction injection molding principle (RIM process) on a 12 l Rimdomat from the company Hennecke, Birlinghoven, in a temperature controlled at 65 ° C Tool (plate shape of dimensions 380 × 200 × 3 mm), whose inner walls be with an external release agent have been layered, injected. The mold life was 30 s. The parts were tempered at 120 ° C for 45 minutes pert. After 14 days of storage at 20 ° C, the Properties of the molded body determined.  

The polyurethane-polyurea plant thus manufactured own substances (according to DIN 53 504) - before tempering - a tensile strength of 26 MPa and an elongation at break of 380%.

Method according to the invention

Granules made from this isocyanate-based plastic was produced, grain size approx. 2 mm to 3 mm, is in an injection molding machine type D 50, manufacturer: company Demag, Nuremberg, at a melt temperature of 180 ° C in a cold tool (for the production of test specimens for Tensile tests) sprayed.

The on this, thermoplastic processed material material properties measured in accordance with DIN 53 504 in train ver are: tensile strength 9 MPa and elongation at break 22%.

Claims (11)

1. Process for the production of granules and mold parts from (A) crosslinked plastics based on isocyanate, optionally in a mixture with (B) thermoplastics, characterized in that as plastics based on isocyanate (A) polyurethane, polyurea - And / or polyurethane than urea plastics are used and where (A) and optionally (B) are in the weight ratio 100: 0-9.99: 90.01, where (A) in the soft segment has an average functionality of <= 2.5 has and where (A) without fillers has a density of <= 0.6, preferably 0.6-1.1 and where (A) has been produced from

• a) organic polyisocyanates,
• b) compounds with a molecular weight of 1800 to 12,000, which on average have at least 2.5 groups capable of reacting with isocyanate groups,
  possibly
• c) (Cyclo) alkane polyols and / or (cyclo) alkane poly amines having ether groups and having a molecular weight in the range from 60 to 1799,
  and if necessary
• d) diamines with two primary and / or secondary, aromatically bound amino groups in the molecular weight range 108-400,
  and possibly also with the use of
• e) auxiliaries and additives known per se from polyurethane chemistry,

while maintaining an isocyanate index of 60 to 140 manufactured in a single or multi-stage process have been provided that at least one of components c) and / or d) in one Amount is used that the total amount of Components c) and / or d) at least 5 wt .-%, be related to the weight of component b). 2. The method according to claim 1, characterized in that that of the two possibly to be used Components c) and d) only the component c) is also used. 3. The method according to claim 1 or 2, characterized records that as component c) the following more valuable alcohols EG, butanediol, DEG also used become. 4. The method according to any one of claims 1 to 3, characterized characterized that a thermoplastic processing tion in the injection molding or extrusion process in Temperature range from 130 ° C-300 ° C, preferably in  Range of 170 ° C-230 ° C, particularly preferably of 170 ° C-210 ° C is made. 5. The method according to any one of claims 1 to 4, characterized characterized in that the thermoplastic processing processing of the plastics (A) and optionally (B) be preferably with dwell times in the range of 10 seconds up to 10 minutes. 6. The method according to any one of claims 1 to 5, characterized characterized in that (A) is a modified, according to the RIM technology processed polyurethane material is. 7. The method according to any one of claims 1 to 5, characterized characterized in that (A) is a modified, according to the Extrusion technology processed polyurethane material. 8. The method according to any one of claims 1 to 7, characterized characterized that to be used if necessary end component (B) polypropylene and modified Polypropylene can be used. 9. The method according to any one of claims 1 to 7, characterized characterized that to be used if necessary Ending component (B) linear thermoplastic poly urethanes can be used. 10. The method according to any one of claims 1 to 7, characterized characterized that to be used if necessary Ending component (B) PVC resins or plasticized PVC can be used.