WO2023142505A1

WO2023142505A1 - Aging-resistant and low-noise tpee fiber material

Info

Publication number: WO2023142505A1
Application number: PCT/CN2022/122351
Authority: WO
Inventors: 胡立峰; 龚雪; 赵锋; 刘婷
Original assignee: 延锋国际汽车技术有限公司
Priority date: 2022-01-29
Filing date: 2022-09-29
Publication date: 2023-08-03
Also published as: CN116554648A

Abstract

The present application relates to a thermoplastic polyester elastomer composition, which comprises, on the basis of the total weight of the composition: A) 80-98% of a thermoplastic polyester elastomer (TPEE); B) 0.1-3% of a diphenylamine antioxidant; C) 0.1-2.8% of a fatty acid amide lubricant; and D) 0.1-2.5% of a tackifier, which is an epoxy functional polymer based on a vinyl aromatic compound and a (meth)acrylic compound. In addition, the present application further relates to a method for preparing such a thermoplastic polyester elastomer fiber material. The fiber material according to the present invention can be used as a cushioning material in an office chair, a sofa, a mattress, a carpet, and a riding seat in a vehicle.

Description

Anti-aging and low-noise TPEE fiber material

field of invention

The present application relates to a TPEE fiber material which in particular has improved aging resistance and low noise properties and also has improved resistance to degradation. Furthermore, the present application also relates to a method for the preparation of such fiber materials.

Background of the invention

Thermoplastic polyester elastomer (TPEE) is a block copolymer, its structure usually contains high melting point, high hardness crystalline polyester hard segment and amorphous polyether or polyester with lower glass transition temperature soft segment. The elastomer has a two-phase association structure, in which the hard segment can play a physical cross-linking role to endow the product with a certain shape stability, and the soft segment can endow the material with high resilience in an amorphous manner. TPEE has both the softness and elasticity of rubber, and the rigidity and ease of processing of thermoplastics. Therefore, this material is widely used as a cushioning material in furniture, home appliances, office supplies, automobiles, trains, ships, or aerospace fields, such as office chairs, sofas, mattresses, carpets, seating seats in vehicles, etc. cushioning material.

Usually, the thermoplastic polyester elastomer raw material is extruded into a continuous bending, random entanglement, and partially thermally bonded random fiber material in a molten state, and then a three-dimensional network structure is obtained by contacting each other with liquid cooling body.

CN103998668B discloses a three-dimensional network structure made of thermoplastic polyester elastomer material. The thermoplastic polyester elastomer is a polyester block copolymer having a high melting point crystalline polymer segment (a) and a low melting point polymer segment (b). In this document, this three-dimensional network structure can be used for seats and mattresses. According to this document, the three-dimensional network structure has flexibility in the extrusion direction by alternately appearing low-volume-density loose regions and high-volume-density compact regions in a certain extrusion direction during manufacture, thereby endowing the manufactured The mattress has reduced noise and resistance to aging at eg 80°C or higher.

However, the current market has put forward higher requirements for the aging resistance and noise reduction performance of TPEE fiber materials. Especially, when needing to use this fiber material for the seat buffer material of vehicles, it is hoped that the aging resistance of the TPEE fiber material can be further improved, especially at a temperature of 140° C. or higher, the fiber can be used in a considerable It does not lose its elasticity over a long period of time and maintains its structure. In addition, it is also hoped that the frictional noise generated between the filaments can be further reduced to improve the ride experience of passengers.

In addition, it is also found that TPEE fiber materials are prone to degradation during the extrusion process, so there is an urgent need to improve the degradation resistance of TPEE materials.

Contents of the invention

In view of the above technical problems, the inventors of the present application found that by screening and optimizing the additives added to the TPEE matrix, the above technical problems can be effectively improved, that is, TPEE with comprehensive improvement in high temperature aging resistance, noise reduction and degradation resistance can be obtained. fiber material.

Therefore, a first aspect of the present invention relates to a thermoplastic polyester elastomer composition comprising, based on the total weight of the composition:

A) 80-98% thermoplastic polyester elastomer TPEE;

B) 0.1-3% diphenylamine antioxidant;

C) 0.1-2.8% fatty acid amide lubricant;

D) 0.1-2.5% of tackifiers which are epoxy-functional polymers based on vinylaromatics and (meth)acrylic compounds.

A second aspect of the invention relates to a process for the preparation of thermoplastic polyester elastomers according to the invention.

The thermoplastic polyester elastomer TPEE suitable for use in the present invention is known per se and is not particularly limited, as long as its structure contains both a high-melting crystalline polyester hard segment and an amorphous polyester with a lower glass transition temperature. Polyether or polyester soft segments.

Accordingly, suitable thermoplastic polyester elastomers TPEE may include polyester-ether block copolymers having thermoplastic polyester as hard segments and polyalkylene glycols as soft segments, or aliphatic polyesters as soft segments. Segmented polyester-ester block copolymers.

In an advantageous embodiment, the thermoplastic polyester elastomer TPEE may comprise hard segments of polyesters based on, for example, aromatic dicarboxylic acids and aliphatic diols and soft segments of aliphatic polyesters and/or polyethers. Segmented polyester-ester or polyester-ether block copolymers.

As the polyester-ether block copolymer, for example, at least one dicarboxylic acid selected from the group consisting of terephthalic acid, isophthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7- Aromatic dicarboxylic acids such as dicarboxylic acid and diphenyl-4,4'-dicarboxylic acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, such as succinic acid, adipic acid, decane Aliphatic dicarboxylic acids such as diacid dimer acids, or their ester-forming derivatives, etc.; and at least one diol component selected from the group consisting of such as 1,4-butanediol, ethylene glycol, triethylene glycol, etc. Aliphatic diols such as methylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, such as 1,1-cyclohexanedimethanol, 1,4-cyclohexane Alicyclic diols such as dimethanol, or their ester-forming derivatives; and at least one polyalkylene glycol selected from the following: such as polyethylene glycol, poly A ternary block copolymer composed of propylene glycol, polytetramethylene glycol or ethylene oxide-propylene oxide copolymer.

As the polyester-ester block copolymer, for example, a triblock composed of at least one of the above-mentioned dicarboxylic acid, diol, and polyester diol such as polylactone having a number average molecular weight of about 300 to 5,000 copolymer. In consideration of thermal adhesiveness, hydrolysis resistance, stretchability, heat resistance, etc., it is particularly preferable to use terephthalic acid and/or naphthalene 2,6-dicarboxylic acid as dicarboxylic acid, and diol component Triblock copolymers of 1,4-butanediol, polytetramethylene glycol as polyalkylene glycol, or triblocks with polylactone as polyester diol copolymer.

In some special cases, for example, those comprising a polysiloxane-based soft segment or a polyolefin-based soft segment may also be used. These soft segments can be incorporated into thermoplastic polyester elastomers by copolymerization or blending.

In an advantageous embodiment, the soft segment content of the thermoplastic polyester elastomer is preferably 15% by weight or more, more preferably 25% by weight or more, further preferably 30% by weight or more, particularly preferably 40% by weight or more, and preferably It is 80 weight% or less, More preferably, it is 70 weight% or less.

Such thermoplastic polyester elastomers are commercially available, for example, as Anitel from DSM or from DuPont or the like.

The thermoplastic polyester elastomer composition according to the present invention should also contain 0.1-3.0%, preferably 0.5-2.6%, more preferably 0.9-2.0% of a diphenylamine antioxidant based on the total weight of the composition. The inventors of the present application have found that when diphenylamine antioxidants are specifically selected (compared to other conventional antioxidants such as hindered phenols or phosphites, etc.) and used in the required amount of 0.1-3.0% for thermoplastic polymer When used in the ester elastomer composition, the aging resistance of the fiber material prepared from the composition can be significantly improved after 7 days at 140° C., and the pulverization phenomenon can be significantly improved. In particular it was found that when diphenylamine antioxidants are used in conjunction with the additional components C) and D) as specified above, the compression set of the material after this heat aging can reach <11%, even <10% and the compressive strength The rate of change reaches <11%, such as <10%, or even <8%.

The diphenylamine compounds suitable for this application are a class of antioxidants, which realize the antioxidant function by capturing free radicals in the chain reaction of polymer degradation, eliminating peroxide free radicals and terminating the oxidation reaction. Generally speaking, diphenylamine antioxidants are based on derivatives of diphenylamine compounds, including two categories of ketoneamines and alkylated diphenylamines. For example, they can have the following structural formula (I):

wherein R1 and R2 represent one or more, preferably one, substituents optionally located on the respective benzene rings, which are selected from C1-C18, preferably C2-C12 or C3-C10 alkyl or aralkyl groups, provided that the structural formula There is at least one R1 or R2 substituent in (I); and both R1 and R2 can also form a linear or branched alkylene group with C1-C8 such as C3-C6 connecting two benzene rings.

Preferably, there are R1 and R2 in the structural formula (I), and R1 and R2 represent one of the substituents located on the respective benzene rings, or both R1 and R2 form the alkylene group connecting two benzene rings group.

Here and in the context, the alkyl group is preferably a linear, branched or cyclic alkyl group having 1-18, more preferably 2-12 and 3-10 C atoms, such as methyl, ethyl, propyl butyl, pentyl, hexyl, heptyl, octyl, nonyl and their isomeric forms. The alkylene group is a linear or branched alkylene group preferably having 1-8 or 3-6 C atoms, such as ethylene, propylene, isopropylene and the like. The aralkyl group is preferably a phenylalkyl group, such as benzyl, phenethyl, α-methylbenzyl, α,α-dimethylbenzyl, phenylisopropyl and the like.

Diphenylamine antioxidants are commercially available, for example as Naugard 445, BLE or DDA.

Particularly preferably, the diphenylamine antioxidant is selected from the following:

The inventors of the present application have found that when the amount of diphenylamine antioxidants is less than 0.1%, the antioxidant efficiency of the fiber material is low, the aging resistance is poor, and powdering is more likely to occur under heat aging conditions; When the amount of oxidizing agent is higher than 3.0%, the aging performance cannot be further improved.

In addition, the inventors of the present application have also found that if 0.1-2.8%, preferably 0.3-2.3%, more preferably 0.5-1.8% of fatty acid amide lubricants are added to the composition based on the total weight of the composition, the Noise-reducing properties of fiber materials made from thermoplastic polyester elastomers combined with resistance to degradation of the material. If the amount of fatty amide lubricant added is too low, the expected noise reduction cannot be achieved. However, if the amount of fatty amide lubricant added is higher than 2.8%, the extruded fiber filaments will be too smooth and difficult to bond and entangle between filaments, unable to form a three-dimensional network structure, and cause the product to be sticky , the rebound is slow, and it will also affect the thermal aging and degradation resistance to a certain extent.

In the present application, the so-called "lubricant" may also be referred to as "slip agent". Fatty acid amide lubricants suitable for adding to the thermoplastic polyester elastomer composition of the present application to reduce the noise of fiber materials are compounds that contain amide groups and saturated or unsaturated aliphatic groups in terms of molecular structure. The fatty acid amide lubricant may contain one or more, for example two, amide groups in its molecule. The aliphatic group is then preferably a linear, branched or cyclic saturated or unsaturated aliphatic group preferably having 6-40, more preferably 8-30, such as 10-25 carbon atoms, and optionally There may be one or more, such as two, carbon-carbon double bonds.

Particularly preferably, the fatty acid amide lubricant is selected from erucamide, oleic acid amide, stearic acid amide such as vinyl bis stearic acid amide or amide wax.

Such fatty acid amide lubricants are known in the art and are commercially available.

In addition, the inventors have also found that if a certain amount of tackifier is further added to the thermoplastic polyester elastomer composition, especially 0.1-2.5%, preferably 0.5-2.2% of epoxy resin based on the total weight of the composition Functional tackifiers based on polymers of vinyl aromatic compound monomers and (meth)acrylic compound monomers can further improve the degradation resistance of polyester elastomers, especially when TPEE fiber materials are extruded When being squeezed out of the machine.

The epoxy-functional polymer based on vinyl aromatic monomers and (meth)acrylic monomers is a polymer consisting mainly of vinyl aromatic monomer units and (meth)acrylic compound monomer units. A main chain is formed, and a plurality of polymers having side chain groups containing epoxy groups are grafted on the main chain. Advantageously, the epoxy-functional polymer based on vinyl aromatic monomers and (meth)acrylic monomers is 90%, preferably 95%, more preferably 98% or 99%, or even completely composed of vinyl It consists of an aromatic compound monomer unit and a (meth)acrylic compound monomer unit. Epoxy groups can be attached to the polymer backbone, for example via C1-C12, preferably C2-C8 (oxy)alkylene groups.

The "(meth)acrylic compound" refers to a compound with methacryloyl or acryloyl, preferably a compound with methacryloxy or acryloyloxy, such as methacrylic acid, acrylic acid, acrylic acid C1 -C12 alkyl ester, C1-C12 alkyl methacrylate, glycidyl methacrylate, glycidyl acrylate, etc.

The vinyl aromatic compounds include styrene monomers and derivatives thereof, especially alkyl (such as C1-C8 alkyl) or halogen-substituted styrene monomers, such as styrene, α-methylstyrene, α-chlorostyrene or p-methylstyrene, etc., preferably styrene.

In a preferred embodiment, the tackifier is an epoxy-functionalized copolymer of styrene and glycidyl (meth)acrylate.

The epoxy-functionalization of the polymers can be carried out in a conventional manner. For example, it can be achieved by adding a copolymerizable monomer with an epoxy group in an amount corresponding to the required epoxy equivalent when preparing the copolymer. The copolymerizable monomer having an epoxy group is, for example, a vinyl monomer having an epoxy group, especially glycidyl (meth)acrylate.

The preparation of such tackifiers is known per se and the products are commercially available. Advantageously, the epoxy-functional polymer based on vinyl aromatic monomers and (meth)acrylic monomers has a weight average molecular weight of 20,000 to 400,000, preferably 50,000 to 200,000 and its epoxy equivalent can be in the range of For example between 100-800 g/mol, preferably 150-650 g/mol. The epoxy equivalent represents the mass of the resin containing 1mol of epoxy groups, expressed in g/mol.

Here, the weight-average molecular weight is measured by GPC using polystyrene as a standard sample.

Here, the epoxy equivalent can be measured according to the ASTM D1652 standard.

In addition to the components mentioned above, other additives can also be added to the thermoplastic polyester elastomer composition of the present invention, as long as these additives do not affect its performance in use and its molding process. Said other additives include, for example, other antioxidants such as hindered phenols and phosphites, UV absorbers such as benzophenones and benzotriazoles, other lubricants such as calcium stearate or silicone-based lubricants, Deodorants, antibacterial agents, antifungal agents, colorants, fragrances, flame retardants and hygroscopic agents, etc.

If used, said other additives are preferably added in an amount in the range of 0.1%-8%, eg 0.5-5%, based on the total weight of the thermoplastic polyester elastomer composition.

Preferably, phosphite antioxidants, hindered phenolic antioxidants and/or ultraviolet absorbers are further used in the range of 0.5-1.5% based on the total weight of the composition. Preference is also given to using calcium stearate and/or silicone-based lubricants in amounts of 0.1 to 5% each, based on the total weight of the composition.

A second aspect of the present application relates to a method for preparing a thermoplastic polyester elastomer according to the present invention, comprising: i) providing the individual components of the thermoplastic polyester elastomer as described above and mixing them, ii) combining the resulting combination melt-extruding the material into fibrous strands at a temperature 10-120° C. higher than its melting point, and iii) randomly entangle and bend the obtained strands to form a three-dimensional network structure.

In the context of this application, "fiber" and "wire" are sometimes used interchangeably, and they refer to a thread-like material whose length is much greater than the cross-sectional diameter (for example, 20 times or more than 50 times), which can usually be melt-extruded get. The cross-sectional shape of the wire or fiber is not particularly limited, for example, it can be a circular cross-section, an elliptical cross-section, a polygonal cross-section, a hollow cross-section or other special-shaped cross-sections, etc., which can impart compression resistance, bulkiness, etc.

The mixing process of step i) can be carried out in any mixing equipment known in the prior art. Preferably, the individual components of the thermoplastic polyester elastomer composition are thoroughly mixed under agitation. The order of addition of the components is not particularly limited. The resulting mixture can be fed immediately to subsequent processing steps.

Steps ii) and iii) are usually carried out successively and continuously. In an exemplary embodiment, specifically, a common melt extruder can be used to heat the mixed thermoplastic elastomer composition to a temperature 10 to 120° C. higher than the melting point to make it into a molten state. For example, in the present invention the temperature of the extruder can be set at a temperature of 180-300°C, preferably 200-280°C. It is then sprayed downwards using a nozzle with multiple orifices and falls naturally to form a ring. At this time, the diameter of the ring, the fineness of the wire, and the number of joints are determined according to the distance between the nozzle surface and the take-up conveyor installed on the cooling medium that solidifies the resin, the melt viscosity of the resin, the diameter of the orifice, and the discharge amount. A pair of take-up conveyor belts installed on the cooling medium with an adjustable interval sandwiches and stops the ejected wire in a molten state to produce a ring. The resulting rings are thus brought into contact with each other, by which the rings form a random three-dimensional shape and the contact portions are fused. Next, the continuous wires formed in a random three-dimensional shape and welded at the contact portion are continuously introduced into a cooling medium (preferably water at room temperature) to solidify to form a network structure.

Next, dehydration drying may be performed as necessary. As an exemplary method of the present invention, pseudocrystallization treatment is performed after cooling once. The pseudocrystallization treatment temperature is at least 10°C lower than the melting point (Tm). When pseudocrystallization is performed by simple heat treatment, heat resistance and sag resistance are improved. In addition, when passing through the drying step after cooling once, the drying temperature can be set to the annealing temperature, so that the pseudo-crystallization treatment can be performed at the same time. In addition, pseudocrystallization treatment may be performed separately.

Finally, the prepared mesh structure can be cut into desired length or shape for cushioning material. When using the network structure of the present invention as a cushioning material, it is necessary to select the used resin, fineness, ring diameter, and bulk density according to the purpose of use and the site of use.

The material according to the present invention has a wide range of applications, for example, it can be used as a cushioning material in furniture, home appliances, office supplies, automobiles, trains, ships or aerospace fields, such as in office chairs, sofas, mattresses, carpets, vehicles, etc. Take the cushioning material in the seat.

Example

The present invention is further illustrated by the following examples, but the present invention obviously should not be limited to these specific examples.

Raw material list

The following raw materials are used in the examples

Table 1

Preparation of thermoplastic polyester elastomer composition

Add 100kg of TPEE into the high mixer, and add diphenylamine antioxidants, hindered phenolic antioxidants, erucic acid according to the percentages shown in the following table 2 ("\" in the table means not added) under stirring conditions Amide, vinyl bis stearic acid amide, silicone lubricant and tackifier, respectively, to obtain a combination of several thermoplastic polyester elastomers.

The combined material obtained in each embodiment is placed in a melting extruder, the temperature of the extruder is set at 210-260°C, and the single-hole spinning rate is 10-60g/min. Spray to the bottom of the spinneret hole, After passing through the heat preservation area directly below the spinneret hole, the molten linear body is bent to form a ring, so that the contact part is welded to form a three-dimensional network structure, and the three-dimensional network structure in the molten state is pulled by the traction conveying plate chain to make it solidify. Subsequent performance tests were performed on the solidified three-dimensional network structure.

Performance Testing

heat aging compression set

According to the method of ISO 2440, the size of the sample is 100mm×100mm, and the sample is stored at 140°C for 168 hours, and then conditioned for 24 hours in a standard environment. After measuring the height of the above-mentioned aged sample, compress the sample to 50% of the thickness of the sample, keep it at 70°C for 22 hours, and store it in a standard environment for 30 minutes in a free state, then measure the height of the sample again , to get the compressive deformation value.

Thermal aging compressive strength change

According to the method of ISO 2440, take a sample size of 100mm×100mm, measure the length and width dimensions, and measure the compressive strength value of the sample in the prepared state. The sample was stored at 140°C for 168 hours, then conditioned for 24 hours in a standard environment, and then the compressive strength value after heat aging was tested according to the same procedure as the compressive strength value in the prepared state to obtain the compressive strength change.

compressive strength

According to the method of ISO 3386-1, the size of the sample is 100mm×100mm. After measuring the length and width, the compressive strength value of the sample in the prepared state is determined.

Noise value

In a quiet room (the number of decibels is less than 35), put the sample on the platform, put a 70kg weight on it at a constant speed, use the decibel meter and the human ear to evaluate respectively, and use the decibel meter to read the maximum value during the process of pressing down the weight. Qualitatively evaluate the volume of sound produced by the sample from the senses.

Melt Index

Put the prepared material sample into a metal sleeve with a fixed inner diameter to heat and apply a load, and measure the mass of the material melt flowing out of a die with a specified diameter within 10 minutes.

Table 2. Composition and performance test results of various embodiments

(embodiments with * are according to the present invention)

Claims

A thermoplastic polyester elastomer composition comprising, based on the total weight of the composition:

A) 80-98% thermoplastic polyester elastomer TPEE;

B) 0.1-3% diphenylamine antioxidant;

C) 0.1-2.8% fatty acid amide lubricant; and

D) 0.1-2.5% of tackifiers which are epoxy-functional polymers based on vinylaromatics and (meth)acrylic compounds.
The thermoplastic polyester elastomer composition according to claim 1, characterized in that the composition comprises 0.5-2.6%, preferably 0.9-2.0%, of diphenylamine antioxidants based on the total weight of the composition, and/or 0.3- 2.3%, preferably 0.5-1.8%, fatty acid amide lubricant.
According to the thermoplastic polyester elastomer composition of claim 1 and 2, it is characterized in that, described diphenylamine antioxidant has following structural formula (I):

wherein R1 and R2 represent one or more, preferably one, substituents optionally located on the respective benzene rings, which are selected from C1-C18, preferably C2-C12 or C3-C10 alkyl or aralkyl groups, provided that the structural formula There is at least one R1 or R2 substituent in (I); and both R1 and R2 can also form a linear or branched alkylene group with C1-C8 such as C3-C6 connecting two benzene rings.
Thermoplastic polyester elastomer composition according to any one of the preceding claims, characterized in that the alkylene group is a linear or branched alkylene group having 1-8 or 3-6 C atoms group, such as ethylene, propylene, isopropylidene, and/or the aralkyl group is phenylalkyl, such as benzyl, phenethyl, α-methylbenzyl, phenylisopropyl base.
The thermoplastic polyester elastomer composition according to any one of the preceding claims, wherein the fatty acid amide lubricant comprises one or two amide groups and an aliphatic group selected from A linear, branched or cyclic saturated or unsaturated aliphatic group preferably has 6-40, more preferably 8-30 such as 10-25 carbon atoms, and optionally may have one or more such as Two carbon-carbon double bonds.
The thermoplastic polyester elastomer composition according to any one of the preceding claims, wherein the fatty acid amide lubricant is selected from the group consisting of erucamide, oleic acid amide, stearic acid amide such as vinyl distearic acid Amide or amide wax, etc.
The thermoplastic polyester elastomer composition according to any one of the preceding claims, characterized in that the composition further comprises phosphite antioxidants, hindered Phenolic antioxidants and/or UV absorbers, and/or further comprising calcium stearate and/or silicone-based lubricants at 0.1-5% based on the total weight of the composition.
Thermoplastic polyester elastomer composition according to any one of the preceding claims, characterized in that the tackifier is an epoxy-functional copolymer of styrene and glycidyl (meth)acrylate, preferably its cyclic The oxygen equivalent weight can be, for example, between 100-800 g/mol, preferably 150-650 g/mol.
A method for preparing a thermoplastic polyester elastomer fiber material, comprising: i) providing and mixing the components of the thermoplastic polyester elastomer composition according to any one of claims 1 to 8, ii) mixing the obtained The mixture is melt-extruded into fibrous strands at a temperature of 10-120° C. above its melting point, and iii) the resulting strands are randomly entangled and bent to form a three-dimensional network structure.
Comprising the thermoplastic polyester elastomer composition according to any one of claims 1 to 8 or the article of thermoplastic polyester elastomer fiber material obtained by the method according to claim 9, it is preferably an office chair, a sofa , mattresses, carpets, and cushioning materials in seats in vehicles.