Polyolefin composition with mineral filler

Abstract

FIELD: structural materials.SUBSTANCE: present invention relates to a polyolefin composition with a mineral filler, intended for the production of heat-resistant packaging products and structural elements requiring increased strength and heat resistance, comprising the following components in the following ratio, wt.%: linear high-density polyethylene from 40 to 50; low-density polyethylene grade HD 10500 FE or HD 85612 IM from 30 to 40; microfibre mineral filler based on a mixture of talc and wollastonite from 15 to 25; special additives: heat stabilizer, antioxidant, fire retardant, antistatic from 5 to 15.EFFECT: production of a composition with improved strength characteristics, characterized by high tensile strength, increased relative elongation at break, increased heat resistance while maintaining low cost and processibillity.5 cl, 2 tbl

Description

[0001] The present invention relates to the creation of a composite material based on a polyolefin matrix reinforced with a mineral filler and can be used in the food, medical, construction, packaging, and household industries. The polyolefin composition with a mineral filler is suitable for the manufacture of heat-resistant packaging, sanitary and hygienic products, technical films, containers, as well as structural and protective elements requiring increased strength, heat resistance, and resistance to aggressive environmental influences.

[0002] Russian Patent 2747552, IPC C08L 23 / 06, C08J 5 / 04, C08K 5 / 09, published June 5, 2021, describes a polyethylene-based composition comprising chrysotile asbestos, an antioxidant, stearic acid, polyethylene wax, pigment, and chlorinated polyethylene. The composition exhibits good physical and mechanical properties, particularly hardness and frost resistance. However, the presence of asbestos filler makes it environmentally and hygienically unacceptable for most modern applications related to packaging and human contact.

[0003] Russian Federation Patent 2625448, IPC E02B 3 / 16, C08J 11 / 06, C08J 5 / 06, C08L 23 / 06, published July 14, 2017, discloses an anti-filtration composite material based on recycled polyethylene reinforced with carbon-graphite fiber stabilized with carbon black. The composition is aimed at hydraulic engineering and construction needs. Disadvantages include limited heat resistance, instability of physical and mechanical properties during processing, and low quality repeatability due to the use of recycled raw materials.

[0004] The composition according to Chinese Patent 105086095 A, IPC C08L 23 / 06, published November 18, 2015, contains polyethylene, talc, and fiberglass. The purpose is to increase strength and heat resistance. However, the reinforcing component is made of rigid glass fibers rather than microfibers, which impairs the distribution of the filler within the matrix and leads to reduced flexibility and processability of the material during processing.

[0005] U.S. Patent 20200214637 A1, IPC C08L 23 / 06, C08K 3 / 36, published July 9, 2020, describes a polypropylene-based composition incorporating wollastonite, designed to improve impact resistance. However, this composition does not contain high-density polyethylene or linear low-density polyethylene, which reduces its suitability for producing flexible, heat-resistant packaging products.

[0006] Also known is patent EP 1607436 B2 (European Patent), IPC C08J 9 / 00, published December 21, 2005. It describes a foaming material based on low-density polyethylene and styrene monomers. However, the composition does not contain reinforcing components and does not provide the required heat resistance and mechanical properties, making it unsuitable for structural applications or those subject to high thermal and physical loads.

[0007] A polymer composition is known according to Russian Patent 2356919 (taken as a prototype), IPC C08L 23 / 00, C08L 77 / 00, C08J 5 / 00, published 05 / 27 / 2009. The composition contains high-density polyethylene, chrysotile asbestos, and silicate lubricant. The material has improved strength characteristics, but a significant drawback is the use of chrysotile asbestos, a toxic substance banned in a number of industries, which limits the use of the composition in the medical and food industries.

[0008] The technical result of the present invention is the creation of a composition with improved strength characteristics, characterized by high tensile strength, increased relative elongation at break, as well as increased heat resistance while maintaining low cost and processability.

[0009] The technical result is achieved through the use of linear high-density polyethylene (LDPE) and low-density polyethylene (LDPE) of the following grades as a polyolefin base: HD 10500 FE according to TU 20.16.10-006-81060768-2018 or HD 85612 IM according to TU 20.16.10-250-00203335-2022. These grades of polyethylene have a high density (0.951-0.961 g / cm 3 ), heat resistance and resistance to deformation.

[0010] A natural microfiber filler based on a mixture of talc and wollastonite is used as a reinforcing component, ensuring good compatibility with the polyolefin matrix and uniform distribution in the structure of the material. In addition, the composition includes a heat stabilizer, antioxidant, flame retardant and antistatic agent. Irgafos® 168 or its domestic analogues: FA-168 or Fosfit 168TL are used as a heat stabilizer. Iridon® 1010 (Irganox 1010) or Irganox 1076 is used as an antioxidant, aluminum triphosphate (ATP), melamine polyphosphate (MPP) or ammonium polyphosphate (APP) are used as a flame retardant, and glycerol monostearate (GMS) or ethoxylated sorbitan monostearate (Polysorbate 60) are used as an antistatic agent.

[0011] The composite manufacturing process involves pre-dispersing the mineral filler, mixing it with functional additives, injecting the mixture into the polyolefin matrix melt, and then processing it via extrusion or casting. The resulting material boasts high heat resistance (up to 150°C), dimensional stability, resistance to aggressive environments, and is recyclable.

[0012] A composite material comprising a polyethylene matrix reinforced with a mineral filler, a heat-stabilizing additive, an antioxidant, a fire retardant and an antistatic agent, characterized in that it contains the following components in the following ratio, wt. %:

[0013] - linear high-pressure polyethylene (LDPE) - from 40 to 50

[0014] - low-pressure polyethylene (LDPE) grade HD 10500 FE according to TU 20.16.10-006-81060768-2018 or HD 85612 IM according to TU 20.16.10-250-00203335-2022 - from 30 to 40

[0015] - microfiber mineral filler based on a mixture of talc and wollastonite - from 15 to 25

[0016] - special additives (thermal stabilizer, antioxidant, fire retardant, antistatic) - from 5 to 15

[0017] In special additives, the total proportion of heat stabilizer is from 1.9 to 4.0; antioxidant from 1.3 to 3.5; fire retardant from 1.3 to 4.0; antistatic from 0.5 to 3.5 wt. % of the composition.

[0018] To evaluate the performance characteristics of the proposed composition, five pilot samples were produced with varying component ratios. The samples used two different grades of low-density polyethylene—HD 10500 FE and HD 85612 IM—in combination with linear high-density polyethylene, a microfiber mineral filler based on talc and wollastonite, and the inclusion of a heat stabilizer, antioxidant, flame retardant, and antistatic agent.

[0019] Table 1 shows the composition of each sample, expressed as mass percent for each component. All values ​​are standardized, and the sum of the components in each case is 100 mass%.

[0020] Table 2 shows the results of physical and mechanical tests, including tensile strength, elongation at break, temperature stability, density and elastic modulus, reflecting the influence of composition on the properties of the material.

[0021] Table 1 - Compositions of the composition

[0022] Components Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 LDPE, wt. % 41,32 43,78 45,19 47,43 48,70 HDPE, wt. % 34,15* 30,04* 28,67* 28,83** 30,21** Talc and wollastonite, wt. % 18,21 15,33 11,14 14,12 7,14 Special additives, wt.% 6,32 10,85 15,00 9,62 13,95

[0023] * HD 10500 FE

[0024] ** HD 85612 IM,

[0025] where for sample 1, special additives were selected in the following mass% ratio: heat stabilizer - 1.9, antioxidant - 1.5, fire retardant - 1.62, antistatic agent - 1.3;

[0026] where for sample 2, special additives were selected in the following wt.% ratio: heat stabilizer - 3.19, antioxidant - 2.58, fire retardant - 2.84, antistatic - 2.24;

[0027] where for sample 3, special additives were selected in the following wt.% ratio: heat stabilizer - 4.0, antioxidant - 3.5, fire retardant - 4.0, antistatic - 3.5;

[0028] where for sample 4, special additives were selected in the following wt.% ratio: heat stabilizer - 2.83, antioxidant - 2.28, fire retardant - 2.53, antistatic - 1.98;

[0029] where for sample 5, special additives were selected in the following wt.% ratio: heat stabilizer - 4.00, antioxidant - 3.31, fire retardant - 3.66, antistatic - 2.98.

[0030] Table 2 - Physical and mechanical characteristics of the composition

[0031] Properties Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Tensile strength, MPa 22,5 24,0 25,0 26,2 26,5 Relative elongation at break, % 460 500 560 610 615 Temperature resistance, °C 120-130 125-135 130-140 135-150 135-150 Density, g / cm3 0,950 0,952 0,954 0,961 0,961 Modulus of elasticity, MPa 280 295 315 345 350

[0032] Samples 1-3 use HDPE HD 10500 FE - have greater fluidity, good processability, slightly lower strength and density.

[0033] Samples 4-5 use HDPE HD 85612 IM - have higher density, strength and heat resistance.

Claims

1. A polyolefin composition with a mineral filler intended for the production of heat-resistant packaging products and structural elements requiring increased strength and heat resistance, containing the following components in the following ratio, wt.%: linear high-pressure polyethylene from 40 to 50; low-pressure polyethylene grade HD 10500 FE or HD 85612 IM from 30 to 40; microfiber mineral filler based on a mixture of talc and wollastonite from 15 to 25; special additives: heat stabilizer, antioxidant, fire retardant, antistatic agent from 5 to 15.

2. A polyolefin composition according to claim 1, characterized in that it contains Irgafos 168 or the phosphite antioxidant FA-168 or Fosfit 168TL as a heat stabilizer.

3. A polyolefin composition according to claim 1, characterized in that it contains Iridon® 1010 (also known as Irganox 1010) or Irganox 1076 (Iridon 1076) as an antioxidant.

4. A polyolefin composition according to claim 1, characterized in that it contains aluminum triphosphate (ATP) or melamine polyphosphate (MPP) or ammonium polyphosphate (APP) as a fire retardant.

5. A polyolefin composition according to claim 1, characterized in that it contains glycerol monostearate (GMS) or ethoxylated sorbitan monostearate (Polysorbate 60, also known as Tween 60) as an antistatic agent.