PLASTIC-COATED MERCAPTOSILANE/WAX MIXTURE

Abstract

The invention relates to a plastics-covered mercaptosilane-wax mixture, where the plastic of the plastics covering is selected from the group of polypropylene, polyethylene, ethylene-vinyl acetate copolymer and mixtures of the abovementioned plastics with melting point from 70 to 170° C., and the mercaptosilane-wax mixture comprises at least one mercaptosilane of the general formula I

##STR00001##

and at least one wax with congealing point from 30 to 160° C.

The plastics-covered mercaptosilane-wax mixture can be used in rubber mixtures.

Claims

1. Plastics-covered mercaptosilane-wax mixture, characterized in that the plastic of the plastics covering is selected from the group of polypropylene, polyethylene, ethylene-vinyl acetate copolymer and mixtures of the abovementioned plastics with melting point from 70 to 170° C., and the mercaptosilane-wax mixture comprises at least one mercaptosilane of the general formula I ##STR00008## where R.sup.1 is an alkyl polyether group —O—(R.sup.5—O).sub.m—R.sup.6, where R.sup.5 is identical or different and is a branched or unbranched, saturated or unsaturated, aliphatic divalent C1-C30 hydrocarbon group, m is on average from 1 to 30, and R.sup.6 is composed of at least 1 C atom and is an unsubstituted or substituted, branched or unbranched monovalent alkyl, alkenyl, aryl or aralkyl group, R.sup.2 is identical or different and is an R.sup.1, C1-C12-alkyl or R.sup.7O group, where R.sup.7 is H, methyl, ethyl, propyl, C9-C30 branched or unbranched monovalent alkyl, alkenyl, aryl, or aralkyl group or (R.sup.8).sub.3Si group, where R.sup.8 is C1-C30 branched or unbranched alkyl or alkenyl group, R.sup.3 is a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30 hydrocarbon group and R.sup.4 is H, CN or (C═O)—R.sup.9, where R.sup.9 is a branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic monovalent C1-C30 hydrocarbon group, and at least one wax with congealing point from 30 to 160° C.

2. Plastics-covered mercaptosilane-wax mixture according to claim 1, characterized in that the plastics covering is a plastics sachet.

3. Plastics-covered mercaptosilane-wax mixture according to claim 1, characterized in that the mercaptosilane-wax mixture comprises a mixture of mercaptosilanes of the general formula I.

4. Plastics-covered mercaptosilane-wax mixture according to claim 3, characterized in that the mixture of mercaptosilanes of the general formula (I) comprises ##STR00009##

5. Plastics-covered mercaptosilane-wax mixture according to claim 1, characterized in that the average molar mass of the plastic of the plastics covering is from 50 000 to 1 000 000 g/mol.

6. Plastics-covered mercaptosilane-wax mixture according to claim 1, characterized in that the thickness of the plastics covering is from 1.0 to 3000 μm.

7. Process for the production of plastics-covered mercaptosilane-wax mixture according to claim 1, characterized in that in a first step a mercaptosilane-wax mixture is obtained through mixing of at least one mercaptosilane of the general formula I with at least one wax with congealing point from 30 to 160° C., and in a second step the mercaptosilane-wax mixture from the first step is charged to a plastics sachet, where the plastic of the sachet is selected from the group of polypropylene, polyethylene, ethylene-vinyl acetate copolymer and mixtures of the abovementioned plastics with melting point from 70 to 170° C., and the plastics sachet is sealed.

8. Process for the production of plastics-covered mercaptosilane-wax mixture according to claim 7, characterized in that a temperature-controllable kneading, stirring, or mixing assembly is used for the mixing process.

9. Process for the production of plastics-covered mercaptosilane-wax mixture according to claim 7, characterized in that the mercaptosilane-wax mixture is produced in the first step at temperatures of from 30 to 260° C.

10. Process for the production of plastics-covered mercaptosilane-wax mixture according to claim 7, characterized in that the charging of the mercaptosilane-wax mixture to the plastics sachet in the second step takes place at temperatures of from 30 to 160° C.

11. A method for the production of rubber mixtures, comprising; introducing the plastics-covered mercaptosilane-wax mixture according to claim 1 to at least one rubber.

12. Rubber mixture, characterized in that this comprises (A) at least one rubber, (B) at least one filler and (C) at least one plastics-covered mercaptosilane-wax mixture according to claim 1.

Description

EXAMPLES

Example 1: (Shelf Life of Plastics Sachet with and without Wax)

Comparative Example 1

[0123] 1. Flat sachet made of unmodified LDPE, dimensions: 170 mm×300 mm (L×W), thickness: 100 μm from neoLab Migge Laborbedarf-Vertriebs GmbH, Germany.

[0124] 2. VP Si 363 silane from Evonik Industries AG.

[0125] 500 g of VP Si 363 is charged under inert conditions (MB 150-GII glovebox from MBraun Inertgas-Systeme GmbH, Germany) to flat polymer sachets, and commercially available film-welding equipment from Braukmann GmbH, Germany (Caso® VC10 Vakuumierer) is used for the welding process.

Inventive Example 1

[0126] 1. Flat sachet made of unmodified LDPE, dimensions: 170 mm×300 mm (L×W), thickness: 100 μm from neoLab Migge Laborbedarf-Vertriebs GnmbH, Germany.

[0127] 2. Protektor G3108 from Paramelt (composition: mixture of refined hydrocarbon waxes, congealing point ≈57° C., relative density ≈from 0.89 to 0.96 g/cm.sup.3 (20° C.), viscosity ≈4 mPas (100° C.).

[0128] 3. VP Si 363 silane from Evonik Industries AG.

[0129] The mercaptosilane-wax mixture is produced by melting Protektor G3108 in the presence of VP Si 363 in a ratio by weight of 1:5 in a 1000 mL glass beaker on a hotplate with stirrer motor at 65° C. under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)). 500 g of the liquid, homogeneous, warm physical mixture of Protektor G3108 and VP Si 363 is then charged under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)) to flat polymer sachets; commercially available film-welding equipment from Braukmann GmbH, Germany (Caso® VC10 Vakuumierer) is used for the welding process, and the material is allowed to cool at room temperature for hardening.

[0130] The samples are stored uncovered in aluminium dishes for 3 months at 23° C. and 50% humidity.

[0131] The shelf life of the samples is evaluated on the basis of the remaining content of VP Si 363 monomer in comparison with oligomeric structures by using .sup.29Si NMR measurements. The results are shown in Table 1.

[0132] The .sup.29Si NMR measurements are made in a 500 MHz “Bruker Avance 500” from Bruker with nitrogen-cooled cryohead (about 2000 scans). For preparation of the samples of the silane/wax mixture, about 0.5 g of the sample is added to a Brand culture tube with screw closure, from 3 to 4 mL of CDCl.sub.3 and Cr(acac).sub.3 are added, and the mixture is treated three times for 15 minutes in a Panasonic 470/H Ultrasound bath. It is then centrifuged and also filtered. An NMR spectrum of the solution is then recorded.

TABLE-US-00001 TABLE 1 Monomer content [mol %] Monomer content prior to [mol %] storage after storage Comparative Example 1 99 73 Inventive Example 1: 97 96

[0133] Ageing effects are greatly suppressed by the combination of LDPE film and Protektor wax when comparison is made with the wax-free Comparative Example 1.

Example 2: (Shelf Life with Wax with and without Film; Comparison of Film Thicknesses)

Comparative Example 2

[0134] Materials Used:

[0135] 1. FLB flat sachet from Polymersynthesewerk GmbH, melting point: 104° C., thickness: 60 μm.

[0136] Polymer: Exxonmobil LD 362 BR produced by A. Schulman GmbH, based on an LDPE/EVA copolymer (vinyl acetate content: 4.5% by weight, density: 0.928 g/cm.sup.3, melt flow rate (190° C./2.16 kg): 2.0 g/10 min).

[0137] 2. Protektor G3108 from Paramelt (composition: mixture of refined hydrocarbon waxes, congealing point ≈57° C., relative density ≈0.89-0.96 g/cm.sup.3 (20° C.), viscosity ≈4 mPas (100° C.).

[0138] 3. VP Si 363 silane from Evonik Industries AG.

[0139] The mixtures are produced by melting Protektor G3108 and VP Si 363 together in a ratio by weight of 1:5 in a 1000 mL glass beaker on a hotplate with stirrer motor at 65° C. under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)). 500 g of the liquid, homogeneous, warm physical mixture of Protektor G3108 and VP Si 363 is then charged under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)) to flat polymer sachets; commercially available film-welding equipment from Braukmann GmbH, Germany (Caso® VC10 Vakuumierer) is used for the welding process, and the material is allowed to cool at room temperature for hardening. The sachet is removed prior to the storage study.

Comparative Example 3

[0140] Materials Used:

[0141] 1. FLB flat sachet from Polymersynthesewerk GmbH, melting point: 104° C., thickness: 60 μm

[0142] Polymer: Exxonmobil LD 362 BR produced by A. Schulman GmbH, based on an LDPE/EVA copolymer (vinyl acetate content: 4.5% by weight, density: 0.928 g/cm.sup.3, melt flow rate (190° C./2.16 kg): 2.0 g/10 min)

[0143] 2. Protektor G3108 from Paramelt (composition: mixture of refined hydrocarbon waxes, congealing point ≈57° C., relative density ≈0.89-0.96 g/cm.sup.3 (20° C.), viscosity ≈4 mPas (100° C.).

[0144] 3. VP Si 363 silane from Evonik Industries AG.

[0145] The mixtures are produced by melting Protektor G3108 and VP Si 363 together in a ratio by weight of 1:5 in a 1000 mL glass beaker on a hotplate with stirrer motor at 65° C. under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)). 500 g of the liquid, homogeneous, warm physical mixture of Protektor G3108 and VP Si 363 is then charged under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)) to flat polymer sachets; commercially available film-welding equipment from Braukmann GmbH, Germany (Caso® VC10 Vakuumierer) is used for the welding process, and the material is allowed to cool at room temperature for hardening.

Comparative Example 4

[0146] Production of the Comparative Example according to the mercaptosilane carbon-black mixture of the invention in Example 1 of WO2013149790.

Inventive Example 2

[0147] Materials Used:

[0148] 1. FLB flat sachet, Antist/Slip/EVA, from Polymersynthesewerk GmbH, antiblock: 1000 ppm, slip: 750 ppm, heat stabilizers, dimensions: 600 mm×900 mm (W×L), melting point: 104° C., weight per metre unfilled: 167 g, thickness: 150 μm

[0149] Polymer: Exxonmobil LD 362 BR produced by A. Schulman GmbH, based on an LDPE/EVA copolymer (vinyl acetate content: 4.5% by weight, density: 0.928 g/cm.sup.3, melt flow rate (190° C./2.16 kg): 2.0 g/10 min)

[0150] Additive (antistatic agent): Polybatch VLA 55 produced by A. Schulman GmbH (additive content: 5% by weight, carrier material: PE, melt flow rate: 20 g/10 min, density: 0.96 g/m.sup.3, bulk density: 550 g/l, moisture content: <1500 ppm.

[0151] 2. Wax: Protektor G3108 from Paramelt (composition: mixture of refined hydrocarbon waxes, congealing point ≈57° C., relative density≈0.89-0.96 g/cm.sup.3 (20° C.), viscosity≈4 mPas (100° C.)).

[0152] 3. VP Si 363 silane from Evonik Industries AG.

[0153] The mixtures are produced by melting Protektor G3108 and VP Si 363 together in a ratio by weight of 1:5 in a 1000 mL glass beaker on a hotplate with stirrer motor at 65° C. under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)). 500 g of the liquid, homogeneous, warm physical mixture of Protektor G3108 and VP Si 363 is then charged under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)) to flat polymer sachets; commercially available film-welding equipment from Braukmann GmbH, Germany (Caso® VC10 Vakuumierer) is used for the welding process, and the material is allowed to cool at room temperature for hardening.

Inventive Example 3

Materials Used:

[0154] 1. FLB flat sachet, Antist/Slip/EVA, from Polymersynthesewerk GmbH, antiblock: 1000 ppm, slip: 750 ppm, heat stabilizers, dimensions: 600 mm×900 mm (W×L), melting point: 104° C., weight per metre unfilled: 167 g, thickness: 150 μm

[0155] Polymer: Exxonmobil LD 362 BR produced by A. Schulman GmbH, based on an LDPE/EVA copolymer (vinyl acetate content: 4.5% by weight, density: 0.928 g/cm, melt flow rate: 2.0 g/10 min)

[0156] Additive (antistatic agent): Polybatch VLA 55 produced by A. Schulman GmbH (additive content: 5% by weight, carrier material: PE, melt flow rate: 20 g/10 min, density: 0.96 g/m.sup.3, bulk density: 550 g/l, moisture content: <1500 ppm.

[0157] 2. Wax: Varazon 5998 from Sasol (composition: mixture of paraffin waxes and hydrocarbon waxes from 50 to 100%, coagulation range a from 64 to 68° C.).

[0158] 3. VP Si 363 silane from Evonik Industries AG.

[0159] The mixtures are produced by melting Varazon 5998 and VP Si 363 together in a ratio by weight of 1:5 in a 1000 mL glass beaker on a hotplate with stirrer motor at 75° C. under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)). 500 g of the liquid, homogeneous, warm physical mixture of Varazon 5998 and VP Si 363 is then charged under inert conditions (glovebox from MBraun Inertgas-Systeme GmbH, Germany (MB 150-GII)) to flat polymer sachets; commercially available film-welding equipment from Braukmann GmbH, Germany (Caso® VC10 Vakuumierer) is used for the welding process, and the material is allowed to cool at room temperature for hardening.

[0160] For accelerated ageing, the samples are stored uncovered in aluminium dishes in a drying cabinet for 7 days at 60° C.

[0161] The shelf life of the samples is evaluated on the basis of the remaining content of VP Si 363 monomer in comparison with oligomeric structures by using .sup.29Si NMR measurements. The results are shown in Table 2.

[0162] The .sup.29Si NMR measurements are made in a 500 MHz “Bruker Avance 500” from Bruker with nitrogen-cooled cryohead (about 2000 scans). For preparation of the samples of the silane/wax mixture and, respectively, silane carbon black mixture, about 0.5 g of the sample is added to a Brand culture tube with screw closure, from 3 to 4 mL of CDCl.sub.3 and Cr(acac).sub.3 are added, and the mixture is treated three times for 15 minutes in a Panasonic 470/H ultrasound bath. It is then centrifuged and also filtered. An NMR spectrum of the solution is then recorded.

TABLE-US-00002 TABLE 2 Monomer content [mol %] Monomer content prior to [mol %] storage after storage Comparative Example 2 97 87 Comparative Example 3 97 Sachet unstable Comparative Example 4 98 <5% Inventive Example 2: 97 95 Inventive Example 3: 97 96

[0163] The results show that the sachet markedly increases shelf life when comparison is made with the uncovered wax-silane mixtures. Inventive Examples 2 and 3 with film thicknesses of 150 μm lead to greater stability in comparison with Comparative Example 3, in which the sachet burst during storage. There is also a significant improvement of shelf life in comparison with the carbon-black-based Comparative Example 4.

Example 3: (Comparison of Carbon Black and Wax/Sachet as Carrier)

[0164] The formulation used for the rubber mixtures is specified in Table 3 below. The unit phr here means parts by weight based on 100 parts of the crude rubber used. Each of the rubber mixtures uses an equimolecular quantity of VP Si 363 silane.

TABLE-US-00003 TABLE 3 Quantity Quantity Substance Quantity [phr] [phr] [phr] 1st stage Ref. Ref. Inv. rubber Rubber Rubber mixture I mixture II mixture III Buna VSL 96.25 96.25 96.25 5025-2 Buna CB 24 30 30 30 ULTRASIL 80 80 80 7000 GR Corax ® N 330 5 — 5 ZnO RS 2 2 2 Edenor ST1 1 1 1 Vivatec 500 8.75 8.75 8.75 Protector 2 2 2 G 3108 Vulkanox 4020/LG 2 2 2 Vulkanox-HS/LG 1.5 1.5 1.5 VP Si 363 ® 9 — — Comparative — 18 — Example 4 Inventive — — 10.80 Example 3 2nd Stage Stage 1 batch 3rd stage Stage 2 batch Perkacit 0.4 0.4 0.4 TBzTD Vulkacit CZ/EG-C 1.6 1.6 1.6 Sulphur 2.0 2.0 2.0

[0165] The polymer VSL 5025-2 is a solution-polymerized SBR copolymer from Lanxess AG, with 25% by weight styrene content and with 50% by weight vinyl fraction. The copolymer comprises 37.5 phr of TDAE oil and its Mooney viscosity (ML 1+4/100° C.) is 47 MU.

[0166] The polymer Buna CB 24 is a high-cis-1,4-polybutadiene (neodymium type) from Lanxess AG, with at least 96% cis-1,4 content and with Mooney viscosity of 44+5 MU.

[0167] Ultrasil 7000 GR is a readily dispersible silica from Evonik Industries AG with BET surface area of 170 m.sup.2/g.

[0168] The carbon black Corax N 330 is from Orion Engineered Carbons GmbH. Vivatec 500 from H&R AG is used as TDAE oil, Vulkanox 4020/LG is 6PPD from Rhein Chemie Rheinau GmbH, Vulkanox HS/LG is TMQ from Rhein Chemie Rheinau GmbH and Protektor G3108 is an antiozonant wax from Paramelt B.V., ZnO RS is ZnO from Arnsperger Chemikalien GmbH, EDENOR ST1 GS 2.0 is palmitic-stearic acid from Caldic Deutschland Chemie B.V. and Vulkacit CZ/EG-C is CBS from Chemie Rheinau GmbH. TBzTD was purchased via Weber & Schaer (producer: Dalian Richon).

[0169] The mixtures were produced in three stages in a 1.5 l internal mixer (E type) with batch temperature 155° C. according to the mixing specification described in Table 4.

TABLE-US-00004 TABLE 4 Stage 1 Settings Mixing from HF Mixing Group GmbH; type GK 1,5 E assembly Fill level 0.65 Rotation rate 70 min.sup.−1 Ram pressure 5.5 bar Chamber temp. 70° C. Mixing procedure 0 to 0.5 min Buna VSL 5025-2 + Buna CB 24 0.5 min TMQ, 6PPD 0.5 to 1 min Mix 1 to 2 min ½ ULTRASIL 7000 GR, silane or silane on HS 45 or plastics-covered mercaptosilane- wax mixture, ZnO, stearic acid 2 min Purge and ventilate 2 to 3 min Carbon black, Vivatec 500, ½ ULTRASIL 7000 GR, Protector G3108 3 min Purge and ventilate 3 to 5 min Mix at 155° C. 5 min Discharge and form milled sheet on laboratory roll mill for 45 s (Laboratory roll mill: diameter 250 mm, length 190 mm, gap between rolls 4 mm, roll temperature 60° C.) 24 h at room temperature Stage 2 Settings Mixing as in stage 1 except assembly Fill level 0.62 Mixing procedure 0 to 0.5 min Break up stage 1 batch 0.5 to 3 min Mix at 155° C. 3 min Discharge and form milled sheet on laboratory roll mill for 45 s (Laboratory roll mill: diameter 250 mm, length 190 mm, gap between rolls 4 mm, roll temperature 60° C.) 4 h at room temperature Stage 3 Settings Mixing as in stage 1 except assembly Fill level 0.59 Rotation rate 50 min.sup.−1 Chamber temp. 50° C. Mixing procedure 0 to 0.5 min Break up stage 2 batch 0.5 to 2 min Accelerator and sulphur, mix at 100° C. 2 min Discharge and form milled sheet on laboratory roll mill for 20 s, and within a further 40 s: cut the material and fold it over 3* towards the left and 3* towards the right, and roll the material 3* with narrow roll gap (3 mm) and draw off milled sheet. (Laboratory roll mill: diameter 250 mm, length 190 mm, gap between rolls from 3 to 4 mm, roll temperature 80° C.) Batch temp. 100° C.

[0170] The general process for the production of rubber mixtures and vulcanizates of these is described in “Rubber Technology Handbook”, W. Hofmann, Hanser Verlag 1994.

[0171] Table 5 gives the rubber testing methods used.

[0172] Vulcanization takes place at a temperature of 165° C. for a period of 8 minutes in a typical vulcanization press with a retention pressure of 120 bar. Table 6 gives the data for crude mixture and vulcanizate.

TABLE-US-00005 TABLE 5 Physical testing Standard/conditions Mooney viscosity ML 1 + 4 at 100° C. ISO 289-1 Mooney viscosity/MU Rheovulcameter measurements at 100° C. Volume after 30 s/mm.sup.3 Rheo-Vulkameter 78.90 Apparent shear rate/s.sup.−1 (Gottfert Werkstoff- Apparent viscosity/Pa s Prufmaschinen GmbH) Nozzle 2 mm × 10 mm test pressure 40 bar, preheat time 60 s Tensile test on specimen at 23° C. ISO 37 Reinforcement index: 300% modulus/50% modulus Shore A hardness at 23° C. ISO 7619-1 Shore A hardness/SH Ball rebound, 23° C. and 70° C. DIN EN ISO 8307 Rebound resilience/% Drop height 500 mm, steel ball d = 19 mm, 28 g Viscoelastic properties of Rubber Process Analyser vulcanizate at 60° C. RPA 2000 (Alpha Technologies), Strain Sweep, 1.7 Hz, 0.28%-42% elongation; see “Operators Manual RPA 2000” from Alpha Technologies, Feb. 1997 Maximum loss factor tan δ Viscoelastic properties at 60° C. ISO 4664-1 16 Hz, 50 N initial force and 25 N amplitude force, 5 min temperature-adjustment time, measured value recorded after 30 s of test time Loss factor tan δ

TABLE-US-00006 TABLE 6 Ref. Ref. Inv. rubber rubber rubber mixture I mixture II mixture III Crude mixture results: Mooney viscosity ML 1 + 4 at 100° C. Mooney viscosity/MU 1st stage 129   129   120   2nd Stage 80   82   78   3rd stage 54   55   53   Rheovulcameter measurements at 100° C. Volume after 30 s/mm.sup.3 1st stage 413   548   577   2nd stage 1067    1010    1125    3rd stage 2058    1933    2201    Apparent shear rate/s.sup.−1 1st stage 18.2 24.6 26.5 2nd stage 47.4 45.0 49.2 3rd stage 91.1 82.9 95.1 Apparent viscosity/Pa s 1st stage 16 234    12 021    11 141    2nd stage 6229    6570    6010    3rd stage 3244    3564    3106    Vulcanizate results: Tensile test on specimen at 23° C. Reinforcement index 300%/50% modulus 10.2 10.5 11.0 Shore A hardness/SH 55   56   55   Ball rebound Rebound resilience at 43.6 43.1 43.4 23° C./% Rebound resilience at 72.3 71.5 74.6 70° C./% Difference: Rebound res. 28.7 28.4 31.2 70° C. − rebound res. 23° C./% Viscoelastic properties, 60° C. Rubber Process Analyser (RPA), Strain Sweep, 1.7 Hz, 0.28%-42% elongation Maximum loss factor tan δ/—   0.116   0.114   0.104 Viscoelastic properties at 60° C., 16 Hz, 50 N initial force, 25 N amplitude force Loss factor tan δ/—   0.094   0.093   0.090

[0173] In comparison with Comparative Mixture I with VP Si 363 alone and Comparative Mixture II according to WO2013149790, the rubber mixture III of the invention exhibits improved processing behaviour (in all three mixing stages lower Mooney and apparent viscosities, higher shear rates, and also volumes after 30 s), improved reinforcement behaviour (higher reinforcement index), improved rolling resistance (lower tan δ values at 60° C., higher rebound resilience at 60° C.) and better realization of the trade-off between wet skid and rolling resistance (difference between rebound resilience values at 70° C. and at 23° C.).