WO2000064982A1

WO2000064982A1 - Composition for producing molded parts which contains ground leather, and method for producing or using said molded parts

Info

Publication number: WO2000064982A1
Application number: PCT/EP2000/003759
Authority: WO
Inventors: Istvan GEBEFÜGI; Georg Menache; Antonius Kettrup; Ferenz Zubonyai; Jenö FEKETE; Károly KADAR
Original assignee: GSF-Forschungszentrum für Umwelt und Gesundheit GmbH
Priority date: 1999-04-27
Filing date: 2000-04-26
Publication date: 2000-11-02
Also published as: BR0010048A; EP1177257A1; AR023611A1; DE19919111C2; CA2367926A1; DE19919111A1

Abstract

The invention relates to a composition that contains leather and/or rubber particles, binders and softeners. The composition is characterized by the properties of natural leather, that is, favorable absorption of humidity, release of humidity, retention of humidity and a long-wearing and flexible behavior while it is easy to process to molded parts. The composition is processed to molded parts by (a) mixing the binder with the softener and the leather and/or rubber particles; (b) transferring the mixture to a mold that is preheated to 120 °C to 160 °C; (c) heat-treating the mixture in the mold for 3 to 20 minutes at maximally 160 °C and (d) cooling and removing the molded part from the mold. The molded parts are useful as components for producing shoes and as sound-absorbing elements for the construction or automotive industry.

Description

Composition containing leather pulp for the production of moldings, process for the production or use of the moldings.

The invention relates to compositions containing leather and / or rubber particles, binders and plasticizers for the production of moldings or processes for the production of the moldings. The invention furthermore relates to the production of the moldings for use as shoe components and as soundproofing elements for the construction and vehicle industries

Description of the technical background / field of the invention

Over the past decade, several applications for the use of tanned leather waste have received patent protection. A significant part of these processes have aimed to produce various molded parts after comminuting the leather waste using a binder

Some of these processes describe the behavior of the leather waste produced after the crushing. This material is not uniform and cannot be processed well, since it contains powders and fibers of various sizes and types / origins depending on the starting leather waste and the type of crushing Structure tends to form a cotton-like fur, which makes further processing difficult These unfavorable properties of the leather waste are not emphasized in the Hungarian patents, but the disadvantages become apparent in the supply of the regrind and the difficulties in evenly applying the binding material Patent application No. HU T / 40 316 (28 12 1986) indicates a knot-free, "homogeneous" leather material as the starting material, a mixing time of 2-3 hours is required to ensure a uniform mixing quality With a few exceptions (e.g. EP 0 92 594 A1, PCT / EP93 / 01812), foreign patent applications pay more attention to the behavior of the leather pulp. In Patent No. 5,346,934, the amount of the small fraction is limited to a certain value by air duct separation. In several Foreign patents (EP 0 256 663 A2, US 5 134 178 and US 5 272 190) are intended to reduce the adhesion of the ground leather and to increase its wettability by steam treatment. In some patented processes (EP 0 089 029 A2, CH 17 828/71 /, as well as CH 17 040/72 /), the leather pulp is processed into the end product using a wet felting process known in the paper industry

Deviating from this, according to US Pat. No. 4,380,474, in the case of polymeric diisocyanates, it is possible to apply corresponding binders with a syringe

Since the tendency of fiber grinders to adhere to the textile industry is known, the processes for forming thick and thin felt have developed. According to some views, the tendency to adhere is related to the surface of the elementary fibers, while in other opinion it is related to the electrostatic charging of the fiber parts

As is evident from the previous interpretations and also supported by our experience, the even application of the binder - especially with a binder content below 50% by weight - can require complicated systems and costly preparation operations, which ultimately affects the competitiveness of the end product on the market

In the patent applications relating to the production of shaped end products, numerous natural and plastic adhesives are proposed as binders in addition to those already mentioned above Diisocyanates are often also ethylene-vinyl acetate copolymers (US Pat. No. 5,272

190, US 5 346 934), and the leather pulp is often incorporated into rubber mixtures (US 5 272 190, US 5 346 394). In the patent US 4 497 871, raw rubber solution is recommended as a binder (HU 204 548 B) and polyvinyl chloride (HU 206 738 B)

The shape of the products made from leather pulp is fixed after the binder has hardened, which can be achieved by drying, solvent removal, cooling, polycondensation and polyaddition.The process parameters depend strongly on the properties of the binder and the millbase and the parameters of the Leather regrind is only considered in some patents - and to a very limited extent.This can result from the fact that in most patents the leather regrind is treated as a full material and it is already considered a success if the properties of the binder are not unacceptably deteriorated by the addition of the leather regrind become

In compositions from the prior art, leather is usually only full material, and the processing changes the mechanical and physicochemical properties of the (natural) leather. In particular, the use of higher temperatures results in partial or complete denaturation of the natural leather with loss of suppleness, flexibility and water absorption

The present invention is therefore based on the object, in deviation from previous practice, to provide a composition containing leather and / or rubber particles and binders in which, in the presence of leather particles, the advantageous properties of natural leather, ie favorable moisture absorption, moisture release, moisture retention and Resilient, flexible behavior is retained and used in the end product, and it is easy to process the composition into molded parts.

A further object of this invention is to provide a process for the production of molded parts from such compositions, the advantageous properties of natural leather being preserved and exploited in the molded parts.

Yet another object of the invention is to use the molded parts produced according to the invention as shoe components and as soundproofing elements for the construction and vehicle industries.

In this invention, leather of natural structure is understood to mean that the leather is of natural origin, in contrast to synthetic leather, and that the leather has not been completely ground to powder and / or has been dewatered or denatured by heat treatment.

Brief description of the invention

These objects are achieved according to the invention in that a composition containing leather and / or rubber particles and binders is provided, characterized in that the composition

30-89.5% by weight leather and / or rubber particles 10-60% by weight binder and 0.5-20% by weight plasticizer

contains.

A preferred composition contains: 30 - 89.5% by weight of leather pulp 10 - 60% by weight of binder and 0.5 - 20% by weight of plasticizer

A further preferred composition contains

30 - 85% by weight of leather pulp 10 - 60% by weight of binder and 2 - 20% by weight of plasticizer

Another preferred composition contains

30 - 89.5% by weight of leather pulp 10 - 49.5% by weight of binder and 0.5 - 20% by weight of plasticizer

It is further preferred according to the invention that the leather pulp is partially or completely, preferably 50 to 100%, replaced by rubber granules

The invention also provides a method for producing molded articles from such compositions, comprising the following steps

(a) Mixing the binder with the plasticizer and the leather and / or rubber particles (according to processes known per se)

(b) transferring the mixture into a mold which is preheated to 120 ° C 160 ° C, preferably 140 ° C - 155 ° C

(c) Heat treatment for 3 - 20 minutes in the mold at a maximum of 160 ° C and

(d) cooling and removing the molding from the die The method according to the invention comprises an effectively performable pressing operation, by means of which it is possible to produce, in a temperature range adapted to the properties of the leather, with minimal flow and with short operating times, end products shaped with different properties, depending on the binder-to-leather ratio

A feature of the method according to the invention is the simple feasibility of the preparatory operations, that is to say the grinding and the application of the binder, which greatly facilitates industrial use

When milling is carried out, the aim is not to produce a homogeneous material or material to be varied between narrow limits. Instead of the uniform physical (formal) appearance, uniform mixtures of fractions of the same shape are produced. The greater adhesion property of the light fraction, the so-called leather down, is used when the binder is applied. The leather is therefore not completely ground to powder, which means that the original leather structure is retained

The process according to the invention is characterized in that the properties of the binder are modified by adding plasticizers in such a way that the original properties of the leather-sensitive material, which is sensitive to warmth, are largely preserved by preventing the decomposition process and minimizing water loss. Thermoplastic and Special space-crosslinked polymers are used, the use of waste recyclates being economically advantageous and a qualitative disadvantage generally not being found

The method according to the invention is environmentally friendly, does not cause water and air pollution in the environment, and the hard waste can be ground again

The resulting oily leather recyclate has a density of 0.7-1.3 g / cm ³ and contains leather parts of a few mm in size embedded in the leather

The end products can have the following two uses, but this does not mean that other applications are restricted

When used in the shoe industry, end products with 30-75% by weight leather regrind can be used independently or combined with different materials

According to the invention, the leather pulp can be partially or completely replaced by rubber granulate, for example from waste or car tire refurbishment, so that compacts, plates and / or molded parts with high proportions of rubber granulate can be produced. The proportion of leather pulp exchanged can vary within wide limits and For example, 50-100% of the leather ground material can be replaced by rubber granules

As acoustic insulation materials, end products with a leather grain content of 50-90% by weight can be used independently or combined with other materials

Another feature of our process is that it can be easily coupled with textiles, paper, natural leather and / or plastic covers that are identical or similar with the binder

Detailed description of the invention

Various patent applications use numerous different shredding systems for processing tanned leather waste The dry and moist crushing plants are considered to be uniform. Accordingly, Dutch filing plants, grinders with knives and hammers or other shredding plants are mentioned in the registrations

In the process according to the invention, the comminution of the leather waste is carried out dry, and in such a way that the resulting regrind natural leather parts of natural structure with a grain size of 1-10 mm (preferably 4-8 mm) in a proportion of 50-80% by weight in the contains light leather fluff fraction, which is randomly distributed in an unordered amount of leather powder and leather fiber residues. The rest, i.e. 50-20% by weight, is powder <1 mm and leather fiber residues> 10 mm

It is possible according to the invention that the leather pulp or the leather particles mentioned is partially or completely replaced by rubber granules. For example, compacts, plates and / or molded parts can be produced, the proportion of leather exchanged preferably being 50 to 100%. The rubber granules can be act, for example, synthetic and / or natural rubber. It is preferred to use rubber granulate from manufacturing waste or from rubber that occurs during vehicle tire reconditioning

A thermoplastic or slightly cross-linked polymer, preferably polyvinyl chloride, ethylene-vinyl acetate copolymer, thermoplastic rubber and slightly cross-linked polyurethane, which is in powder form and can be melted in a temperature range below 160 ° C., can be used as the binder Soft foams used in the furniture and vehicle industry or soft integral foams used in the shoe and vehicle industries. The binder regrind has to meet the requirement that 100% of the material falls through a 1.25 mm sieve according to the DIN standard, but 15% of the material remains on a 0.63 mm sieve according to DIN standards. The required fineness can generally be achieved using simple methods It is further preferred according to the invention to use PVC

Powder, preferably semi-hard PVC powder, to be used as a binder regrind

The binder regrind is mixed with chlorinated or non-chlorinated phosphoric acid ester of 2 - 20% by weight - mostly 5 - 15% by weight - based on the total composition or with other plasticizers adapted to the binder. The leather regrind described above is then added. The amount of the leather pulp can be varied within wide limits in relation to the binder, ie in the range from 50 to 89.5% by weight (0.5 times to 8.95 times the quantity). A preferred ratio is 100 to 400% by weight of leather pulp ( 1 - 4 times the amount), based on the mass of the binder.After a few minutes of mixing, a preliminary product is created in which the natural leather particles and the grains of the binding material are randomly distributed in the cotton-like downy fur. The polar plasticizer improves the adhesion of the binder grains to the Leather fluff to a large extent, so that the material with a minimal loss of funds from the mixing system into the press mold can be berfuhrt or without change of the ratio can be moved and distributed

The shaping can be carried out by a heat treatment of 3-20 minutes, depending on the thickness of the product, in the mold which is pre-heated to 120-160 ° C, preferably 140-155 ° C

The properties of the finished product can vary within a wide range, depending on the composition, and for the modification of the properties, the above-mentioned insertion of the textile, paper and plastic couplings which can be coupled with the binder means further possibilities Practical examples

The following examples relate to the use of leather recyclate. However, the scope of the invention is not intended to be limited thereby. In particular, the partial or complete replacement of the leather by rubber granules is also included in the invention

1 example

Production of a 300 x 150 x 5 mm, 0.8 g / cm ³ dense leather recyclate with a non-woven textile cover with a weight of 20 g / m ² on one side

54 g regrind from 54 g semi-hard polyurethane integral foam, which has the parameters described above with regard to the grain size and can also be produced from production or recovered waste, are mixed with 10 g Trιs (chloro-isoproyl) phosphate plasticizer without knots. Then 108 g leather regrind admixed, which has the size and composition parameters described above. After a few murmurs of Ruhr, the leather grain absorbs the binder grain and the two fractions do not separate or cannot be separated from one another

This cotton-like material is placed in the mold, which has been preheated to 155 ° C, after the textile cover has already been distributed in the mold and after the system has been closed, an 8-minute heat treatment is carried out. After the system has cooled, the finished part can be removed

2 example

Production of a 300 x 150 x 10 mm, 1.0 g / cm ³ dense leather recyclate without cover The production process is identical to that described in the first example, with the difference that 350 g of leather, 85 g of semi-hard foam and 15 g of plasticizer are used to produce the end product. The mixture is transferred directly to the lower surface of the mold and the duration of the heat treatment will be extended by 10 minutes

3 example

Production of a 300 x 150 x 10 mm, 1, 2 g / cm ³ dense leather recyclate without cover

This production process is a variant of that described in Example 2, the binder being 175 g of semi-hard PVC powder and moistened with 20 g of dioctyl phthalate as a plasticizer

4 example

Production of a 300 x 150 x 5 mm, 1, 1 g / cm ³ dense leather recyclate with a paper-Alufo e combination on one side

100 g of thermoplastic rubber powder, which has the grain size parameters described above, is knot-free mixed with 3 g of dioctyl phthalate as a plasticizer.This material is then mixed with 250 g of leather pulp, which has the parameters and composition described above. After a few minutes of stirring, after the leather pulp has taken up the binder, the pulp the cotton-like material is transferred to the press mold preheated to 145 ° C, into which the paper-aluminum combination with the paper surface was placed upwards. The material was distributed evenly in the system and after closing the system it was on the for 6 minutes specified temperature maintained. After the tool has cooled, the finished product is removed.

5th example

Production of a 300 x 150 x 10 mm, 1, 15 g / cm ³ dense leather recyclate without cover.

The Hersteilungsprozeß ^is' by the method described in Example 4 is identical, except that here 100 g of ethylene-vinyl acetate copolymer were used as a binding material, which was dampened with 10 g Dioctylphatalat. Furthermore, the heat treatment is carried out for 8 minutes at 155 ° C. Since there is no reference, the mixture is transferred directly to the lower surface of the mold.

Claims

EXPECTATIONS

1. Leather and / or rubber particles and binder containing composition, characterized in that the composition

30 - 89.5% by weight leather and / or rubber particles 10 - 60% by weight binder and 0.5 - 20% by weight plasticizer

contains.

2. Composition according to claim 1, characterized in that the composition

30 - 89.5% by weight of leather pulp 10 - 60% by weight of binder and 0.5 - 20% by weight of plasticizer

contains.

3. Composition according to claim 2, characterized in that the leather is partially or completely replaced by rubber granules.

4. Composition according to claim 3, characterized in that the leather is 50% to 100% replaced by rubber granules.

5. Composition according to one of claims 2 to 4, characterized in that the leather ground material consists of leather parts of natural structure, 50-80 wt .-% of the leather parts having a grain size of 1-10 mm, preferably 4-8 mm.

6. Composition according to one or more of the preceding claims, characterized in that it is used as a binder thermoplastic polymers and / or slightly crosslinked

Contains polymers.

7. Composition according to one or more of the preceding claims, characterized in that it contains spatially crosslinked PU foams as thermoplastic polymers.

8. The composition according to one or more of the preceding claims, characterized in that it contains waste regrind of the soft foams used in the furniture and vehicle industry or the soft integral foams used in the shoe and vehicle industry as binders.

9. Composition according to one or more of the preceding claims, characterized in that the binder has a melting point below 160 ° C.

10. The composition according to one or more of the preceding claims, characterized in that that it contains a pulverulent binder regrind in which 100% of the particles fall through a 1.25 mm sieve according to DIN standard and 15% of the particles remain on a 0.63 mm sieve according to DIN standard.

1 1. Composition according to one or more of the preceding claims, characterized in that the binder regrind is PVC powder, preferably semi-hard PVC powder.

12. The composition according to one or more of the preceding claims, characterized in that it contains polar plasticizers, preferably phosphoric acid esters or phthalates, as plasticizers.

13. The composition according to claim 12, characterized in that it contains tris (chloroisopropyl) phosphate and / or dioctyl phthalate as plasticizer.

14. A method for producing molded parts from compositions according to one or more of the preceding claims, comprising the following steps:

a. Mixing the binder with the plasticizer and the leather and / or rubber particles (according to methods known per se) b. Transferring the mixture into a press mold which is preheated to 120 ° C.-160 ° C., preferably 140 ° C.-155 ° C. c. Heat treatment for 3-20 minutes in the press mold at a maximum of 160 ° C and d. Cooling and removal of the molded part from the press mold.

15. The method according to claim 14, wherein the binder is first mixed with the plasticizer, and then the resulting mixture is mixed with the ground leather.

16. The method according to any one of claims 14 or 15, wherein the molded part is provided with a cover made of textiles, paper, natural leather, metals, plastics or combinations thereof, by adding a cover made of one or more of the above materials to the mold before adding the composition is placed in the mold.

17. The method according to any one of claims 14 to 16, characterized in that the leather ground material consists of leather parts of natural structure, 50-80 wt .-% of the leather parts having a grain size of 1-10 mm, preferably 4-8 mm.

18. The method according to any one of claims 14 to 17, characterized in that thermoplastic polymers and / or slightly crosslinked polymers are used as binders.

19. The method according to any one of claims 14 to 18, characterized in that spatially crosslinked PU foams are used as binders.

20. The method according to any one of claims 14 to 19, characterized in that waste ground material of the soft foams used in the furniture and vehicle industry or of the soft integral foams used in the shoe and vehicle industry is used as a binder.

21. The method according to any one of claims 14 to 20, characterized in that the binder has a melting point below 160 ° C.

22. The method according to any one of claims 14 to 21, characterized in that binder regrind is used in which 100% of the particles fall through a 1.25 mm sieve according to DIN standard and 15% of the particles on a 0.63 mm -Lay sieve according to DIN standard.

23. The method according to any one of claims 14 to 22, characterized in that polar plasticizers, preferably phosphoric acid esters or phthalates are used as plasticizers.

24. The method according to any one of claims 14 to 23, characterized in that tris (chloroisopropyl) phosphate and / or dioctyl phthalate are used as plasticizers.

25. Use of molded parts, produced according to one of claims 14 to 24, as acoustic insulation material in the construction and vehicle industries or as a shoe component, the molded part

30 - 89.5% by weight of ground leather, 10 - 60% by weight of binder, 0.5 - 20% by weight of plasticizer

contains and is optionally provided with a cover made of textiles, paper, natural leather, metals, plastics or combinations thereof.

26. Use of molded parts, produced according to one of claims 14 to 24, as acoustic insulation material in the construction and vehicle industries, the molded part having a leather meal content of 50-89.5% by weight and optionally with a cover made of textiles, paper , Natural leather, metals, plastics or combinations thereof is provided.

27. Use of molded parts, produced according to one of claims 14 to 24, as a shoe component, the molded part having a leather meal content of 30-75% by weight and optionally with a cover made of textiles, paper, natural leather, metals, plastics or combinations thereof is provided.