ADDITIVE CONTAINING LIQUID MASTERBATCH FORMULATIONS FOR POLYMER ARTICLES

Abstract

The invention relates to a thermoplastic resin composition comprising an additive formulation, the use of said formulation as a liquid additive concentrate in a thermoplastic resin composition, methods for improving specific properties of additives in a thermoplastic resin composition, the use of specific carriers for improving said properties, and a kit of parts for preparing a thermoplastic resin composition. In particular, specific carrier substances enhance the technical efficiency of additives, if these are introduced into polymers derived from ethylenically unsaturated monomers, such as polyolefins.

Claims

1. A thermoplastic resin composition prepared from: (I) 0.01 to 2 parts by weight, based on 100 parts by weight of components (I) and (II), of a liquid formulation comprising (a) 20 to 99 parts by weight, based on 100 parts by weight of components (a) and (b), of at least one liquid carrier selected from the group consisting of fatty acid esters of polyfunctional alcohols, synthetic oils, vegetable oils, animal oils, mineral oils, fatty acids, polyalkylene glycols, esters of polyalkylene glycols, silicones, polyolefins, modified rosin, alkyl esters of polyfunctional carboxylic acids, polyesters and water; and (b) 1 to 80 parts by weight, based on 100 parts by weight of components (a) and (b), of at least one additive, which is different from (a); and (II) 98 to 99.99 parts by weight, based on 100 parts by weight of components (I) and (II) of a polymer containing repeating units derived from at least one ethylenically unsaturated monomer.

2. The thermoplastic resin composition according to claim 1, wherein the at least one liquid carrier (a) of the liquid formulation (I) is selected from the group consisting of sorbitan monooleate, ethoxylated sorbitan monooleate, sorbitan trioleate, ethoxylated sorbitan trioleate, polybutylene, polyisobutylene, canola oil, grindsted oil, mineral oil, water, oleic acid, soybean oil, modified rosin, polyethylene glycol, polyethylene glycol esters, silicones, dioctyl terephthalate, 1,2-cyclohexane dicarboxylic acid diisononyl ester, dioctyl adipate, polyethylene adipate and diethyl phthalate.

3. The thermoplastic resin composition according to claim 1, wherein the at least one liquid carrier (a) of the liquid formulation (I) is used in an amount of 90 to 99 parts by weight, based on 100 parts by weight of components (a) and (b), and is selected from the group consisting of sorbitan monooleate, ethoxylated sorbitan monooleate, sorbitan trioleate, ethoxylated sorbitan trioleate, polybutylene, polyisobutylene, canola oil, grindsted oil, mineral oil, oleic acid, soybean oil, modified rosin, silicones, dioctyl terephthalate, 1,2-cyclohexane dicarboxylic acid diisononyl ester, dioctyl adipate, and diethyl phthalate.

4. The thermoplastic resin composition according to claim 1, wherein the at least one additive (b) of the liquid formulation (I) is selected from the group consisting of primary antioxidants, secondary antioxidants, polymer process aids (PPA), slip additives, antistatic additives, neutralizing agents, hindered amine light stabilizers (HALS), UV absorbers, chemical foaming agents, antifog additives, tackifying agents, surface modifiers and colorants.

5. The thermoplastic resin composition according to claim 1, wherein the at least one additive (b) in the liquid formulation (I) is used in an amount of 1 to 10 parts by weight, based on 100 parts by weight of components (a) and (b), and is selected from the group consisting of primary antioxidants, secondary antioxidants, polymer process aids (PPA), slip additives and chemical foaming agents.

6. The thermoplastic resin composition according to claim 1, wherein the repeating units derived from an ethylenically unsaturated monomer in the polymer (II) are selected from the groups consisting of ethylene, alpha-olefins and styrene.

7. A liquid formulation component (I) as a liquid additive concentrate in a thermoplastic resin composition, comprising a polymer containing repeating units derived from at least one ethylenically unsaturated monomer, wherein the liquid formulation component (I) comprises: (a) 20 to 99 parts by weight, based on 100 parts by weight of components (a) and (b), of at least one liquid carrier selected from the group consisting of fatty acid esters of polyfunctional alcohols, synthetic oils, vegetable oils, animal oils, mineral oils, fatty acids, polyalkylene glycols, esters of polyalkylene glycols, silicones, polyolefins, modified rosin, alkyl esters of polyfunctional carboxylic acids, polyesters and water; and (b) 1 to 80 parts by weight, based on 100 parts by weight of components (a) and (b), of at least one additive, which is different from (a).

8. The liquid formulation component according to claim 7, wherein the repeating units, derived from ethylenically unsaturated monomers, are selected from the group consisting of ethylene, alpha-olefins and styrene.

9. A method for improving the technical efficiency of an additive in a thermoplastic resin composition comprising the step of dispersing or dissolving the additive (b) in a liquid carrier component (a) as defined in claim 1 prior to the introduction of the additive (b) into the thermoplastic resin composition.

10. A method for reducing the decomposition rate of an additive (b) in a thermoplastic resin composition due to thermal processing or ageing of the composition, comprising the step of dispersing or dissolving the additive (b) in a liquid carrier component (a) as defined in claim 1 prior to the introduction of the additive (b) into the thermoplastic resin composition.

11. The method according to claim 9, wherein the additive (b) is used in an amount of 1 to 10 parts by weight, based on 100 parts by weight of components (a) and (b).

12. The method according to claim 9, wherein the thermoplastic resin composition comprises a polymer (II) including repeating units derived from at least one ethylenically unsaturated monomer.

13. The method according to claim 10, wherein the additive (b) is used in an amount of 1 to 10 parts by weight, based on 100 parts by weight of components (a) and (b).

14. The method according to claim 10, wherein the thermoplastic resin composition comprises a polymer (II) including repeating units derived from at least one ethylenically unsaturated monomer.

15. A kit of parts suitable for preparing a thermoplastic resin composition according to claim 1, containing (I) a liquid formulation comprising (a) 20 to 99 parts by weight, based on 100 parts by weight of components (a) and (b), of at least one liquid carrier selected from the group consisting of fatty acid esters of polyfunctional alcohols, synthetic oils, vegetable oils, animal oils, mineral oils, fatty acids, polyalkylene glycols, esters of polyalkylene glycols, silicones, polyolefins, modified rosin, alkyl esters of polyfunctional carboxylic acids, polyesters and water; and (b) 1 to 80 parts by weight, based on 100 parts by weight of components (a) and (b), of at least one additive, which is different from (a); and (II) a polymer containing repeating units derived from at least one ethylenically unsaturated monomer.

Description

EXAMPLES

Comparative Example 1

[0063] 3 parts by weight of a polymer processing aid (Kynar Flex® 5301 distributed by Arkema) 4 parts by weight of a secondary antioxidant (Irgafos® 168 distributed by BASF) and 1.5 parts by weight of a primary antioxidant (Irganox® 1076 distributed by BASF) were dispersed in 91.5 parts by weight of molten polyethylene (Braskem LLDPE IC32 distributed by Braskem) using a twin screw and pelletized to give a solid masterbatch (C-1).

Example 1

[0064] 18 parts by weight of a polymer processing aid (Kynar Flex® 5301 distributed by Arkema) 24 parts by weight of a secondary antioxidant (Irgafos® 168 distributed by BASF) and 6 parts by weight of a primary antioxidant (Irganox® 1076 distributed by BASF) were dispersed in 52 parts by weight of a liquid polybutylene carrier (Braskem PIB 6 distributed by Braskem) using a MorehouseCowles disperser and a basket mill to give a liquid formulation (I-1).

Comparative Example 2

[0065] 2 parts by weight of the solid masterbatch (C-1) obtained in comparative example 1 were mixed with 98 parts by weight of LDPE (Braskem TX7003 distributed by Braskem) in a single screw extruder to give a thermoplastic resin composition (R—C1) comprising 600 ppm of the polymer process aid, 800 ppm of the secondary antioxidant and 300 ppm of the primary antioxidant. (R—C1) was continuously fed into a stretch cast film production line to obtain a stretch cast film (P—C1). The production line had to be stopped for mechanical cleaning after 45 days of continuous operation due to enrichment of thermal decomposition products. Both resin and masterbatch must be melted thus resulting in a difficult mixing of the additives that are intended to protect the resin and the masterbatch itself, and resulting in a higher degree of degradation of the overall polymer formulation that used for the cast film production.

Example 2

[0066] 0.05 parts by weight of the liquid formulation (I-1) obtained in example 1 were mixed with 99.95 parts by weight of LDPE (Braskem TX7003 distributed by Braskem) in a single screw extruder to give a thermoplastic resin composition (R-1) comprising 90 ppm of the polymer process aid, 120 ppm of the secondary antioxidant and 30 ppm of the primary antioxidant. (R-1) was continuously fed into a stretch cast film production line to obtain a stretch cast film (P-1). The production line had to be stopped for mechanical cleaning after 120 days of continuous operation due to enrichment of thermal decomposition products. Since the liquid masterbatch does not undergo thermal stress during its preparation and also does not need to be melted before being added to the resin, it already starts protecting the polymer during the mixing, resulting in better performance, despite smaller quantities of additives admixed to the polymer during the cast film production.

[0067] From the above example 2 and comparative example 2, it is evident, that despite the smaller amount of additives and carrier used in the inventive example, which is an economical advantage, a technical advantage of improved processability and reduced rate of decomposition is observed, if the liquid formulation (I-1) is used instead of the solid masterbatch (C-1).

Comparative Example 3

[0068] 2 parts by weight of a slip additive (erucamide) were dispersed in 98 parts by weight of molten LLDPE (Braskem IC32 distributed by Braskem) using a twin screw extruder to give a solid masterbatch (C-2).

Example 3

[0069] 40 parts by weight of a slip additive (erucamide) were dispersed in 60 parts by weight of a polyisobutylene carrier (Braskem PIB 6 distributed by Braskem) using a MorehouseCowles disperser to give a liquid formulation (I-2).

Comparative Example 4

[0070] 3 parts by weight of the solid mast masterbatch (C-2) obtained in comparative example 3 were mixed with 97 parts by weight of LDPE

[0071] (Braskem TX7003 distributed by Braskem) in a single screw extruder to give a thermoplastic resin composition (R—C2) comprising 600 ppm of the slip additive (erucamide). (R—C2) was continuously fed into a blow film production line to obtain a blow film (P—C2). The coefficient of friction of the blow film immediately after production was 0.23.

[0072] After 1 month of storage in a warehouse, the coefficient of friction increased to 0.25. Coefficient of friction is a dimensionless measure of the ability of one layer of film to move between other layers of film or along a fixed surface. Since erucamide is a migrating additive, the speed of its migration to the surface of the film and consequent buildup of this erucamide layer allow easier slip between film layers in a bobbin or between the film and a fixed surface.

Example 4

[0073] 0.15 parts by weight of the liquid formulation (1-2) obtained in example 3 were mixed with 99.85 parts by weight of LDPE (Braskem TX7003, a low-density, high molecular weight polyethylene, MFR (190°/2.16 kg; D1238) of 0.27 g/10 min; distributed by Braskem) in a single screw extruder to give a thermoplastic resin composition (R-2) comprising 600 ppm of the slip additive (erucamide). (R-2) was continuously fed into a blow film production line to obtain a blow film (P-2). The coefficient of friction of the blow film immediately after production was 0.17.

[0074] After 1 month of storage in a warehouse, the coefficient of friction remained 0.17. Thus the liquid carrier led to better uniformity of the erucamide along the surface of the film, resulting in more controlled migration of the additive. Thus, the overall product performance is improved by using a liquid carrier for the additive.

[0075] From the above example 4 and comparative example 4, it is evident, that despite the same amount of additives and reduced amount of carrier used in the inventive example, which is an economical advantage, a technical advantage of an improved coefficient of friction and an improved storage stability in view of the coefficient of friction are achieved, if the liquid formulation (1-2) is used instead of the solid masterbatch (C-2).

Comparative Example 5

[0076] 20 parts by weight of a chemical foaming agent (sodium citrate) were dispersed in 80 parts by weight of molten polystyrene (innova N 1921 distributed by innova) using a twin-screw extruder to give a solid masterbatch (C-3).

Example 5

[0077] 40 parts by weight of a chemical foaming agent (sodium citrate) were dispersed in 60 parts by weight of mineral oil carrier using a MorehouseCowles disperser and milled at a basket mill afterwards to give a liquid formulation (1-3).

Comparative Example 6

[0078] 3 parts by weight of the liquid formulation (C-3) obtained in example 5 were mixed with 97 parts by weight of polystyrene (U8815 distributed by Unigel) in a single screw extruder to give a thermoplastic resin composition (R—C3) comprising 6000 ppm of the chemical foaming agent (sodium citrate). (R—C3) was continuously fed into a production line for a 3-layer polystyrene sheet for yoghurt containers, as the intermediate layer material. The overall density of the 3-layer polystyrene sheet (P—C3) was reduced by 18% in comparison to the corresponding sheet without a foaming agent. Layer thickness proportions were 20/60/20 and the total sheet thickness was 1.05 mm.

Example 6

[0079] 0.8 parts by weight of the liquid formulation (1-3) obtained in example 5 were mixed with 98.2 parts by weight of polystyrene (U8815 distributed by Unigel) in a single screw extruder to give a thermoplastic resin composition (R-3) comprising 3200 ppm of the chemical foaming agent (sodium citrate). (R-3) was continuously fed into a production line for a 3-layer polystyrene sheet (P-3) for yoghurt containers, as the intermediate layer material.

[0080] The overall density of the 3-layer polystyrene sheet was reduced by 18% in comparison to the corresponding sheet without a foaming agent. The size of gas bubbles in (P-3) was smaller and more homogeneous than the size of gas bubbles in (P—C3), affecting mechanical properties to a lesser degree and resulting in better finishing of the produced part. Also, the same density reduction was achieved using less of the additive.

[0081] From the above example 6 and comparative example 6, it is evident, that despite the smaller amount of additives and reduced amount of carrier used in the inventive example, which is an economical advantage, the weight reduction of the product is not affected, and a technical advantage of smaller and more homogeneous gas bubbles is achieved, if the liquid formulation (I-3) is used instead of the solid masterbatch (C-3).